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md: Convert mddev->new_chunk to sectors.
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / md / raid1.c
1 /*
2 * raid1.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat
5 *
6 * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman
7 *
8 * RAID-1 management functions.
9 *
10 * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
11 *
12 * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
13 * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
14 *
15 * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
16 * bitmapped intelligence in resync:
17 *
18 * - bitmap marked during normal i/o
19 * - bitmap used to skip nondirty blocks during sync
20 *
21 * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology:
22 * - persistent bitmap code
23 *
24 * This program is free software; you can redistribute it and/or modify
25 * it under the terms of the GNU General Public License as published by
26 * the Free Software Foundation; either version 2, or (at your option)
27 * any later version.
28 *
29 * You should have received a copy of the GNU General Public License
30 * (for example /usr/src/linux/COPYING); if not, write to the Free
31 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32 */
33
34 #include <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)
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 = (r1bio_t *)(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 = (r1bio_t *)(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 rcu_read_lock();
580 for (i = 0; i < mddev->raid_disks; i++) {
581 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
582 if (rdev && !test_bit(Faulty, &rdev->flags)) {
583 struct request_queue *q = bdev_get_queue(rdev->bdev);
584
585 /* Note the '|| 1' - when read_balance prefers
586 * non-congested targets, it can be removed
587 */
588 if ((bits & (1<<BDI_async_congested)) || 1)
589 ret |= bdi_congested(&q->backing_dev_info, bits);
590 else
591 ret &= bdi_congested(&q->backing_dev_info, bits);
592 }
593 }
594 rcu_read_unlock();
595 return ret;
596 }
597
598
599 static int flush_pending_writes(conf_t *conf)
600 {
601 /* Any writes that have been queued but are awaiting
602 * bitmap updates get flushed here.
603 * We return 1 if any requests were actually submitted.
604 */
605 int rv = 0;
606
607 spin_lock_irq(&conf->device_lock);
608
609 if (conf->pending_bio_list.head) {
610 struct bio *bio;
611 bio = bio_list_get(&conf->pending_bio_list);
612 blk_remove_plug(conf->mddev->queue);
613 spin_unlock_irq(&conf->device_lock);
614 /* flush any pending bitmap writes to
615 * disk before proceeding w/ I/O */
616 bitmap_unplug(conf->mddev->bitmap);
617
618 while (bio) { /* submit pending writes */
619 struct bio *next = bio->bi_next;
620 bio->bi_next = NULL;
621 generic_make_request(bio);
622 bio = next;
623 }
624 rv = 1;
625 } else
626 spin_unlock_irq(&conf->device_lock);
627 return rv;
628 }
629
630 /* Barriers....
631 * Sometimes we need to suspend IO while we do something else,
632 * either some resync/recovery, or reconfigure the array.
633 * To do this we raise a 'barrier'.
634 * The 'barrier' is a counter that can be raised multiple times
635 * to count how many activities are happening which preclude
636 * normal IO.
637 * We can only raise the barrier if there is no pending IO.
638 * i.e. if nr_pending == 0.
639 * We choose only to raise the barrier if no-one is waiting for the
640 * barrier to go down. This means that as soon as an IO request
641 * is ready, no other operations which require a barrier will start
642 * until the IO request has had a chance.
643 *
644 * So: regular IO calls 'wait_barrier'. When that returns there
645 * is no backgroup IO happening, It must arrange to call
646 * allow_barrier when it has finished its IO.
647 * backgroup IO calls must call raise_barrier. Once that returns
648 * there is no normal IO happeing. It must arrange to call
649 * lower_barrier when the particular background IO completes.
650 */
651 #define RESYNC_DEPTH 32
652
653 static void raise_barrier(conf_t *conf)
654 {
655 spin_lock_irq(&conf->resync_lock);
656
657 /* Wait until no block IO is waiting */
658 wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
659 conf->resync_lock,
660 raid1_unplug(conf->mddev->queue));
661
662 /* block any new IO from starting */
663 conf->barrier++;
664
665 /* No wait for all pending IO to complete */
666 wait_event_lock_irq(conf->wait_barrier,
667 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
668 conf->resync_lock,
669 raid1_unplug(conf->mddev->queue));
670
671 spin_unlock_irq(&conf->resync_lock);
672 }
673
674 static void lower_barrier(conf_t *conf)
675 {
676 unsigned long flags;
677 spin_lock_irqsave(&conf->resync_lock, flags);
678 conf->barrier--;
679 spin_unlock_irqrestore(&conf->resync_lock, flags);
680 wake_up(&conf->wait_barrier);
681 }
682
683 static void wait_barrier(conf_t *conf)
684 {
685 spin_lock_irq(&conf->resync_lock);
686 if (conf->barrier) {
687 conf->nr_waiting++;
688 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
689 conf->resync_lock,
690 raid1_unplug(conf->mddev->queue));
691 conf->nr_waiting--;
692 }
693 conf->nr_pending++;
694 spin_unlock_irq(&conf->resync_lock);
695 }
696
697 static void allow_barrier(conf_t *conf)
698 {
699 unsigned long flags;
700 spin_lock_irqsave(&conf->resync_lock, flags);
701 conf->nr_pending--;
702 spin_unlock_irqrestore(&conf->resync_lock, flags);
703 wake_up(&conf->wait_barrier);
704 }
705
706 static void freeze_array(conf_t *conf)
707 {
708 /* stop syncio and normal IO and wait for everything to
709 * go quite.
710 * We increment barrier and nr_waiting, and then
711 * wait until nr_pending match nr_queued+1
712 * This is called in the context of one normal IO request
713 * that has failed. Thus any sync request that might be pending
714 * will be blocked by nr_pending, and we need to wait for
715 * pending IO requests to complete or be queued for re-try.
716 * Thus the number queued (nr_queued) plus this request (1)
717 * must match the number of pending IOs (nr_pending) before
718 * we continue.
719 */
720 spin_lock_irq(&conf->resync_lock);
721 conf->barrier++;
722 conf->nr_waiting++;
723 wait_event_lock_irq(conf->wait_barrier,
724 conf->nr_pending == conf->nr_queued+1,
725 conf->resync_lock,
726 ({ flush_pending_writes(conf);
727 raid1_unplug(conf->mddev->queue); }));
728 spin_unlock_irq(&conf->resync_lock);
729 }
730 static void unfreeze_array(conf_t *conf)
731 {
732 /* reverse the effect of the freeze */
733 spin_lock_irq(&conf->resync_lock);
734 conf->barrier--;
735 conf->nr_waiting--;
736 wake_up(&conf->wait_barrier);
737 spin_unlock_irq(&conf->resync_lock);
738 }
739
740
741 /* duplicate the data pages for behind I/O */
742 static struct page **alloc_behind_pages(struct bio *bio)
743 {
744 int i;
745 struct bio_vec *bvec;
746 struct page **pages = kzalloc(bio->bi_vcnt * sizeof(struct page *),
747 GFP_NOIO);
748 if (unlikely(!pages))
749 goto do_sync_io;
750
751 bio_for_each_segment(bvec, bio, i) {
752 pages[i] = alloc_page(GFP_NOIO);
753 if (unlikely(!pages[i]))
754 goto do_sync_io;
755 memcpy(kmap(pages[i]) + bvec->bv_offset,
756 kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len);
757 kunmap(pages[i]);
758 kunmap(bvec->bv_page);
759 }
760
761 return pages;
762
763 do_sync_io:
764 if (pages)
765 for (i = 0; i < bio->bi_vcnt && pages[i]; i++)
766 put_page(pages[i]);
767 kfree(pages);
768 PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size);
769 return NULL;
770 }
771
772 static int make_request(struct request_queue *q, struct bio * bio)
773 {
774 mddev_t *mddev = q->queuedata;
775 conf_t *conf = mddev->private;
776 mirror_info_t *mirror;
777 r1bio_t *r1_bio;
778 struct bio *read_bio;
779 int i, targets = 0, disks;
780 struct bitmap *bitmap;
781 unsigned long flags;
782 struct bio_list bl;
783 struct page **behind_pages = NULL;
784 const int rw = bio_data_dir(bio);
785 const int do_sync = bio_sync(bio);
786 int cpu, do_barriers;
787 mdk_rdev_t *blocked_rdev;
788
789 /*
790 * Register the new request and wait if the reconstruction
791 * thread has put up a bar for new requests.
792 * Continue immediately if no resync is active currently.
793 * We test barriers_work *after* md_write_start as md_write_start
794 * may cause the first superblock write, and that will check out
795 * if barriers work.
796 */
797
798 md_write_start(mddev, bio); /* wait on superblock update early */
799
800 if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
801 if (rw == WRITE)
802 md_write_end(mddev);
803 bio_endio(bio, -EOPNOTSUPP);
804 return 0;
805 }
806
807 wait_barrier(conf);
808
809 bitmap = mddev->bitmap;
810
811 cpu = part_stat_lock();
812 part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
813 part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
814 bio_sectors(bio));
815 part_stat_unlock();
816
817 /*
818 * make_request() can abort the operation when READA is being
819 * used and no empty request is available.
820 *
821 */
822 r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
823
824 r1_bio->master_bio = bio;
825 r1_bio->sectors = bio->bi_size >> 9;
826 r1_bio->state = 0;
827 r1_bio->mddev = mddev;
828 r1_bio->sector = bio->bi_sector;
829
830 if (rw == READ) {
831 /*
832 * read balancing logic:
833 */
834 int rdisk = read_balance(conf, r1_bio);
835
836 if (rdisk < 0) {
837 /* couldn't find anywhere to read from */
838 raid_end_bio_io(r1_bio);
839 return 0;
840 }
841 mirror = conf->mirrors + rdisk;
842
843 r1_bio->read_disk = rdisk;
844
845 read_bio = bio_clone(bio, GFP_NOIO);
846
847 r1_bio->bios[rdisk] = read_bio;
848
849 read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
850 read_bio->bi_bdev = mirror->rdev->bdev;
851 read_bio->bi_end_io = raid1_end_read_request;
852 read_bio->bi_rw = READ | do_sync;
853 read_bio->bi_private = r1_bio;
854
855 generic_make_request(read_bio);
856 return 0;
857 }
858
859 /*
860 * WRITE:
861 */
862 /* first select target devices under spinlock and
863 * inc refcount on their rdev. Record them by setting
864 * bios[x] to bio
865 */
866 disks = conf->raid_disks;
867 #if 0
868 { static int first=1;
869 if (first) printk("First Write sector %llu disks %d\n",
870 (unsigned long long)r1_bio->sector, disks);
871 first = 0;
872 }
873 #endif
874 retry_write:
875 blocked_rdev = NULL;
876 rcu_read_lock();
877 for (i = 0; i < disks; i++) {
878 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
879 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
880 atomic_inc(&rdev->nr_pending);
881 blocked_rdev = rdev;
882 break;
883 }
884 if (rdev && !test_bit(Faulty, &rdev->flags)) {
885 atomic_inc(&rdev->nr_pending);
886 if (test_bit(Faulty, &rdev->flags)) {
887 rdev_dec_pending(rdev, mddev);
888 r1_bio->bios[i] = NULL;
889 } else
890 r1_bio->bios[i] = bio;
891 targets++;
892 } else
893 r1_bio->bios[i] = NULL;
894 }
895 rcu_read_unlock();
896
897 if (unlikely(blocked_rdev)) {
898 /* Wait for this device to become unblocked */
899 int j;
900
901 for (j = 0; j < i; j++)
902 if (r1_bio->bios[j])
903 rdev_dec_pending(conf->mirrors[j].rdev, mddev);
904
905 allow_barrier(conf);
906 md_wait_for_blocked_rdev(blocked_rdev, mddev);
907 wait_barrier(conf);
908 goto retry_write;
909 }
910
911 BUG_ON(targets == 0); /* we never fail the last device */
912
913 if (targets < conf->raid_disks) {
914 /* array is degraded, we will not clear the bitmap
915 * on I/O completion (see raid1_end_write_request) */
916 set_bit(R1BIO_Degraded, &r1_bio->state);
917 }
918
919 /* do behind I/O ? */
920 if (bitmap &&
921 atomic_read(&bitmap->behind_writes) < bitmap->max_write_behind &&
922 (behind_pages = alloc_behind_pages(bio)) != NULL)
923 set_bit(R1BIO_BehindIO, &r1_bio->state);
924
925 atomic_set(&r1_bio->remaining, 0);
926 atomic_set(&r1_bio->behind_remaining, 0);
927
928 do_barriers = bio_barrier(bio);
929 if (do_barriers)
930 set_bit(R1BIO_Barrier, &r1_bio->state);
931
932 bio_list_init(&bl);
933 for (i = 0; i < disks; i++) {
934 struct bio *mbio;
935 if (!r1_bio->bios[i])
936 continue;
937
938 mbio = bio_clone(bio, GFP_NOIO);
939 r1_bio->bios[i] = mbio;
940
941 mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
942 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
943 mbio->bi_end_io = raid1_end_write_request;
944 mbio->bi_rw = WRITE | do_barriers | do_sync;
945 mbio->bi_private = r1_bio;
946
947 if (behind_pages) {
948 struct bio_vec *bvec;
949 int j;
950
951 /* Yes, I really want the '__' version so that
952 * we clear any unused pointer in the io_vec, rather
953 * than leave them unchanged. This is important
954 * because when we come to free the pages, we won't
955 * know the originial bi_idx, so we just free
956 * them all
957 */
958 __bio_for_each_segment(bvec, mbio, j, 0)
959 bvec->bv_page = behind_pages[j];
960 if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags))
961 atomic_inc(&r1_bio->behind_remaining);
962 }
963
964 atomic_inc(&r1_bio->remaining);
965
966 bio_list_add(&bl, mbio);
967 }
968 kfree(behind_pages); /* the behind pages are attached to the bios now */
969
970 bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
971 test_bit(R1BIO_BehindIO, &r1_bio->state));
972 spin_lock_irqsave(&conf->device_lock, flags);
973 bio_list_merge(&conf->pending_bio_list, &bl);
974 bio_list_init(&bl);
975
976 blk_plug_device(mddev->queue);
977 spin_unlock_irqrestore(&conf->device_lock, flags);
978
979 /* In case raid1d snuck into freeze_array */
980 wake_up(&conf->wait_barrier);
981
982 if (do_sync)
983 md_wakeup_thread(mddev->thread);
984 #if 0
985 while ((bio = bio_list_pop(&bl)) != NULL)
986 generic_make_request(bio);
987 #endif
988
989 return 0;
990 }
991
992 static void status(struct seq_file *seq, mddev_t *mddev)
993 {
994 conf_t *conf = mddev->private;
995 int i;
996
997 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
998 conf->raid_disks - mddev->degraded);
999 rcu_read_lock();
1000 for (i = 0; i < conf->raid_disks; i++) {
1001 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1002 seq_printf(seq, "%s",
1003 rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1004 }
1005 rcu_read_unlock();
1006 seq_printf(seq, "]");
1007 }
1008
1009
1010 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1011 {
1012 char b[BDEVNAME_SIZE];
1013 conf_t *conf = mddev->private;
1014
1015 /*
1016 * If it is not operational, then we have already marked it as dead
1017 * else if it is the last working disks, ignore the error, let the
1018 * next level up know.
1019 * else mark the drive as failed
1020 */
1021 if (test_bit(In_sync, &rdev->flags)
1022 && (conf->raid_disks - mddev->degraded) == 1) {
1023 /*
1024 * Don't fail the drive, act as though we were just a
1025 * normal single drive.
1026 * However don't try a recovery from this drive as
1027 * it is very likely to fail.
1028 */
1029 mddev->recovery_disabled = 1;
1030 return;
1031 }
1032 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1033 unsigned long flags;
1034 spin_lock_irqsave(&conf->device_lock, flags);
1035 mddev->degraded++;
1036 set_bit(Faulty, &rdev->flags);
1037 spin_unlock_irqrestore(&conf->device_lock, flags);
1038 /*
1039 * if recovery is running, make sure it aborts.
1040 */
1041 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1042 } else
1043 set_bit(Faulty, &rdev->flags);
1044 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1045 printk(KERN_ALERT "raid1: Disk failure on %s, disabling device.\n"
1046 "raid1: Operation continuing on %d devices.\n",
1047 bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
1048 }
1049
1050 static void print_conf(conf_t *conf)
1051 {
1052 int i;
1053
1054 printk("RAID1 conf printout:\n");
1055 if (!conf) {
1056 printk("(!conf)\n");
1057 return;
1058 }
1059 printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1060 conf->raid_disks);
1061
1062 rcu_read_lock();
1063 for (i = 0; i < conf->raid_disks; i++) {
1064 char b[BDEVNAME_SIZE];
1065 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
1066 if (rdev)
1067 printk(" disk %d, wo:%d, o:%d, dev:%s\n",
1068 i, !test_bit(In_sync, &rdev->flags),
1069 !test_bit(Faulty, &rdev->flags),
1070 bdevname(rdev->bdev,b));
1071 }
1072 rcu_read_unlock();
1073 }
1074
1075 static void close_sync(conf_t *conf)
1076 {
1077 wait_barrier(conf);
1078 allow_barrier(conf);
1079
1080 mempool_destroy(conf->r1buf_pool);
1081 conf->r1buf_pool = NULL;
1082 }
1083
1084 static int raid1_spare_active(mddev_t *mddev)
1085 {
1086 int i;
1087 conf_t *conf = mddev->private;
1088
1089 /*
1090 * Find all failed disks within the RAID1 configuration
1091 * and mark them readable.
1092 * Called under mddev lock, so rcu protection not needed.
1093 */
1094 for (i = 0; i < conf->raid_disks; i++) {
1095 mdk_rdev_t *rdev = conf->mirrors[i].rdev;
1096 if (rdev
1097 && !test_bit(Faulty, &rdev->flags)
1098 && !test_and_set_bit(In_sync, &rdev->flags)) {
1099 unsigned long flags;
1100 spin_lock_irqsave(&conf->device_lock, flags);
1101 mddev->degraded--;
1102 spin_unlock_irqrestore(&conf->device_lock, flags);
1103 }
1104 }
1105
1106 print_conf(conf);
1107 return 0;
1108 }
1109
1110
1111 static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1112 {
1113 conf_t *conf = mddev->private;
1114 int err = -EEXIST;
1115 int mirror = 0;
1116 mirror_info_t *p;
1117 int first = 0;
1118 int last = mddev->raid_disks - 1;
1119
1120 if (rdev->raid_disk >= 0)
1121 first = last = rdev->raid_disk;
1122
1123 for (mirror = first; mirror <= last; mirror++)
1124 if ( !(p=conf->mirrors+mirror)->rdev) {
1125
1126 blk_queue_stack_limits(mddev->queue,
1127 rdev->bdev->bd_disk->queue);
1128 /* as we don't honour merge_bvec_fn, we must never risk
1129 * violating it, so limit ->max_sector to one PAGE, as
1130 * a one page request is never in violation.
1131 */
1132 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1133 queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9))
1134 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
1135
1136 p->head_position = 0;
1137 rdev->raid_disk = mirror;
1138 err = 0;
1139 /* As all devices are equivalent, we don't need a full recovery
1140 * if this was recently any drive of the array
1141 */
1142 if (rdev->saved_raid_disk < 0)
1143 conf->fullsync = 1;
1144 rcu_assign_pointer(p->rdev, rdev);
1145 break;
1146 }
1147
1148 print_conf(conf);
1149 return err;
1150 }
1151
1152 static int raid1_remove_disk(mddev_t *mddev, int number)
1153 {
1154 conf_t *conf = mddev->private;
1155 int err = 0;
1156 mdk_rdev_t *rdev;
1157 mirror_info_t *p = conf->mirrors+ number;
1158
1159 print_conf(conf);
1160 rdev = p->rdev;
1161 if (rdev) {
1162 if (test_bit(In_sync, &rdev->flags) ||
1163 atomic_read(&rdev->nr_pending)) {
1164 err = -EBUSY;
1165 goto abort;
1166 }
1167 /* Only remove non-faulty devices is recovery
1168 * is not possible.
1169 */
1170 if (!test_bit(Faulty, &rdev->flags) &&
1171 mddev->degraded < conf->raid_disks) {
1172 err = -EBUSY;
1173 goto abort;
1174 }
1175 p->rdev = NULL;
1176 synchronize_rcu();
1177 if (atomic_read(&rdev->nr_pending)) {
1178 /* lost the race, try later */
1179 err = -EBUSY;
1180 p->rdev = rdev;
1181 }
1182 }
1183 abort:
1184
1185 print_conf(conf);
1186 return err;
1187 }
1188
1189
1190 static void end_sync_read(struct bio *bio, int error)
1191 {
1192 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1193 int i;
1194
1195 for (i=r1_bio->mddev->raid_disks; i--; )
1196 if (r1_bio->bios[i] == bio)
1197 break;
1198 BUG_ON(i < 0);
1199 update_head_pos(i, r1_bio);
1200 /*
1201 * we have read a block, now it needs to be re-written,
1202 * or re-read if the read failed.
1203 * We don't do much here, just schedule handling by raid1d
1204 */
1205 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1206 set_bit(R1BIO_Uptodate, &r1_bio->state);
1207
1208 if (atomic_dec_and_test(&r1_bio->remaining))
1209 reschedule_retry(r1_bio);
1210 }
1211
1212 static void end_sync_write(struct bio *bio, int error)
1213 {
1214 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1215 r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
1216 mddev_t *mddev = r1_bio->mddev;
1217 conf_t *conf = mddev->private;
1218 int i;
1219 int mirror=0;
1220
1221 for (i = 0; i < conf->raid_disks; i++)
1222 if (r1_bio->bios[i] == bio) {
1223 mirror = i;
1224 break;
1225 }
1226 if (!uptodate) {
1227 int sync_blocks = 0;
1228 sector_t s = r1_bio->sector;
1229 long sectors_to_go = r1_bio->sectors;
1230 /* make sure these bits doesn't get cleared. */
1231 do {
1232 bitmap_end_sync(mddev->bitmap, s,
1233 &sync_blocks, 1);
1234 s += sync_blocks;
1235 sectors_to_go -= sync_blocks;
1236 } while (sectors_to_go > 0);
1237 md_error(mddev, conf->mirrors[mirror].rdev);
1238 }
1239
1240 update_head_pos(mirror, r1_bio);
1241
1242 if (atomic_dec_and_test(&r1_bio->remaining)) {
1243 sector_t s = r1_bio->sectors;
1244 put_buf(r1_bio);
1245 md_done_sync(mddev, s, uptodate);
1246 }
1247 }
1248
1249 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
1250 {
1251 conf_t *conf = mddev->private;
1252 int i;
1253 int disks = conf->raid_disks;
1254 struct bio *bio, *wbio;
1255
1256 bio = r1_bio->bios[r1_bio->read_disk];
1257
1258
1259 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1260 /* We have read all readable devices. If we haven't
1261 * got the block, then there is no hope left.
1262 * If we have, then we want to do a comparison
1263 * and skip the write if everything is the same.
1264 * If any blocks failed to read, then we need to
1265 * attempt an over-write
1266 */
1267 int primary;
1268 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1269 for (i=0; i<mddev->raid_disks; i++)
1270 if (r1_bio->bios[i]->bi_end_io == end_sync_read)
1271 md_error(mddev, conf->mirrors[i].rdev);
1272
1273 md_done_sync(mddev, r1_bio->sectors, 1);
1274 put_buf(r1_bio);
1275 return;
1276 }
1277 for (primary=0; primary<mddev->raid_disks; primary++)
1278 if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
1279 test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) {
1280 r1_bio->bios[primary]->bi_end_io = NULL;
1281 rdev_dec_pending(conf->mirrors[primary].rdev, mddev);
1282 break;
1283 }
1284 r1_bio->read_disk = primary;
1285 for (i=0; i<mddev->raid_disks; i++)
1286 if (r1_bio->bios[i]->bi_end_io == end_sync_read) {
1287 int j;
1288 int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
1289 struct bio *pbio = r1_bio->bios[primary];
1290 struct bio *sbio = r1_bio->bios[i];
1291
1292 if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
1293 for (j = vcnt; j-- ; ) {
1294 struct page *p, *s;
1295 p = pbio->bi_io_vec[j].bv_page;
1296 s = sbio->bi_io_vec[j].bv_page;
1297 if (memcmp(page_address(p),
1298 page_address(s),
1299 PAGE_SIZE))
1300 break;
1301 }
1302 } else
1303 j = 0;
1304 if (j >= 0)
1305 mddev->resync_mismatches += r1_bio->sectors;
1306 if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
1307 && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
1308 sbio->bi_end_io = NULL;
1309 rdev_dec_pending(conf->mirrors[i].rdev, mddev);
1310 } else {
1311 /* fixup the bio for reuse */
1312 int size;
1313 sbio->bi_vcnt = vcnt;
1314 sbio->bi_size = r1_bio->sectors << 9;
1315 sbio->bi_idx = 0;
1316 sbio->bi_phys_segments = 0;
1317 sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1318 sbio->bi_flags |= 1 << BIO_UPTODATE;
1319 sbio->bi_next = NULL;
1320 sbio->bi_sector = r1_bio->sector +
1321 conf->mirrors[i].rdev->data_offset;
1322 sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
1323 size = sbio->bi_size;
1324 for (j = 0; j < vcnt ; j++) {
1325 struct bio_vec *bi;
1326 bi = &sbio->bi_io_vec[j];
1327 bi->bv_offset = 0;
1328 if (size > PAGE_SIZE)
1329 bi->bv_len = PAGE_SIZE;
1330 else
1331 bi->bv_len = size;
1332 size -= PAGE_SIZE;
1333 memcpy(page_address(bi->bv_page),
1334 page_address(pbio->bi_io_vec[j].bv_page),
1335 PAGE_SIZE);
1336 }
1337
1338 }
1339 }
1340 }
1341 if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) {
1342 /* ouch - failed to read all of that.
1343 * Try some synchronous reads of other devices to get
1344 * good data, much like with normal read errors. Only
1345 * read into the pages we already have so we don't
1346 * need to re-issue the read request.
1347 * We don't need to freeze the array, because being in an
1348 * active sync request, there is no normal IO, and
1349 * no overlapping syncs.
1350 */
1351 sector_t sect = r1_bio->sector;
1352 int sectors = r1_bio->sectors;
1353 int idx = 0;
1354
1355 while(sectors) {
1356 int s = sectors;
1357 int d = r1_bio->read_disk;
1358 int success = 0;
1359 mdk_rdev_t *rdev;
1360
1361 if (s > (PAGE_SIZE>>9))
1362 s = PAGE_SIZE >> 9;
1363 do {
1364 if (r1_bio->bios[d]->bi_end_io == end_sync_read) {
1365 /* No rcu protection needed here devices
1366 * can only be removed when no resync is
1367 * active, and resync is currently active
1368 */
1369 rdev = conf->mirrors[d].rdev;
1370 if (sync_page_io(rdev->bdev,
1371 sect + rdev->data_offset,
1372 s<<9,
1373 bio->bi_io_vec[idx].bv_page,
1374 READ)) {
1375 success = 1;
1376 break;
1377 }
1378 }
1379 d++;
1380 if (d == conf->raid_disks)
1381 d = 0;
1382 } while (!success && d != r1_bio->read_disk);
1383
1384 if (success) {
1385 int start = d;
1386 /* write it back and re-read */
1387 set_bit(R1BIO_Uptodate, &r1_bio->state);
1388 while (d != r1_bio->read_disk) {
1389 if (d == 0)
1390 d = conf->raid_disks;
1391 d--;
1392 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1393 continue;
1394 rdev = conf->mirrors[d].rdev;
1395 atomic_add(s, &rdev->corrected_errors);
1396 if (sync_page_io(rdev->bdev,
1397 sect + rdev->data_offset,
1398 s<<9,
1399 bio->bi_io_vec[idx].bv_page,
1400 WRITE) == 0)
1401 md_error(mddev, rdev);
1402 }
1403 d = start;
1404 while (d != r1_bio->read_disk) {
1405 if (d == 0)
1406 d = conf->raid_disks;
1407 d--;
1408 if (r1_bio->bios[d]->bi_end_io != end_sync_read)
1409 continue;
1410 rdev = conf->mirrors[d].rdev;
1411 if (sync_page_io(rdev->bdev,
1412 sect + rdev->data_offset,
1413 s<<9,
1414 bio->bi_io_vec[idx].bv_page,
1415 READ) == 0)
1416 md_error(mddev, rdev);
1417 }
1418 } else {
1419 char b[BDEVNAME_SIZE];
1420 /* Cannot read from anywhere, array is toast */
1421 md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
1422 printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error"
1423 " for block %llu\n",
1424 bdevname(bio->bi_bdev,b),
1425 (unsigned long long)r1_bio->sector);
1426 md_done_sync(mddev, r1_bio->sectors, 0);
1427 put_buf(r1_bio);
1428 return;
1429 }
1430 sectors -= s;
1431 sect += s;
1432 idx ++;
1433 }
1434 }
1435
1436 /*
1437 * schedule writes
1438 */
1439 atomic_set(&r1_bio->remaining, 1);
1440 for (i = 0; i < disks ; i++) {
1441 wbio = r1_bio->bios[i];
1442 if (wbio->bi_end_io == NULL ||
1443 (wbio->bi_end_io == end_sync_read &&
1444 (i == r1_bio->read_disk ||
1445 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
1446 continue;
1447
1448 wbio->bi_rw = WRITE;
1449 wbio->bi_end_io = end_sync_write;
1450 atomic_inc(&r1_bio->remaining);
1451 md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
1452
1453 generic_make_request(wbio);
1454 }
1455
1456 if (atomic_dec_and_test(&r1_bio->remaining)) {
1457 /* if we're here, all write(s) have completed, so clean up */
1458 md_done_sync(mddev, r1_bio->sectors, 1);
1459 put_buf(r1_bio);
1460 }
1461 }
1462
1463 /*
1464 * This is a kernel thread which:
1465 *
1466 * 1. Retries failed read operations on working mirrors.
1467 * 2. Updates the raid superblock when problems encounter.
1468 * 3. Performs writes following reads for array syncronising.
1469 */
1470
1471 static void fix_read_error(conf_t *conf, int read_disk,
1472 sector_t sect, int sectors)
1473 {
1474 mddev_t *mddev = conf->mddev;
1475 while(sectors) {
1476 int s = sectors;
1477 int d = read_disk;
1478 int success = 0;
1479 int start;
1480 mdk_rdev_t *rdev;
1481
1482 if (s > (PAGE_SIZE>>9))
1483 s = PAGE_SIZE >> 9;
1484
1485 do {
1486 /* Note: no rcu protection needed here
1487 * as this is synchronous in the raid1d thread
1488 * which is the thread that might remove
1489 * a device. If raid1d ever becomes multi-threaded....
1490 */
1491 rdev = conf->mirrors[d].rdev;
1492 if (rdev &&
1493 test_bit(In_sync, &rdev->flags) &&
1494 sync_page_io(rdev->bdev,
1495 sect + rdev->data_offset,
1496 s<<9,
1497 conf->tmppage, READ))
1498 success = 1;
1499 else {
1500 d++;
1501 if (d == conf->raid_disks)
1502 d = 0;
1503 }
1504 } while (!success && d != read_disk);
1505
1506 if (!success) {
1507 /* Cannot read from anywhere -- bye bye array */
1508 md_error(mddev, conf->mirrors[read_disk].rdev);
1509 break;
1510 }
1511 /* write it back and re-read */
1512 start = d;
1513 while (d != read_disk) {
1514 if (d==0)
1515 d = conf->raid_disks;
1516 d--;
1517 rdev = conf->mirrors[d].rdev;
1518 if (rdev &&
1519 test_bit(In_sync, &rdev->flags)) {
1520 if (sync_page_io(rdev->bdev,
1521 sect + rdev->data_offset,
1522 s<<9, conf->tmppage, WRITE)
1523 == 0)
1524 /* Well, this device is dead */
1525 md_error(mddev, rdev);
1526 }
1527 }
1528 d = start;
1529 while (d != read_disk) {
1530 char b[BDEVNAME_SIZE];
1531 if (d==0)
1532 d = conf->raid_disks;
1533 d--;
1534 rdev = conf->mirrors[d].rdev;
1535 if (rdev &&
1536 test_bit(In_sync, &rdev->flags)) {
1537 if (sync_page_io(rdev->bdev,
1538 sect + rdev->data_offset,
1539 s<<9, conf->tmppage, READ)
1540 == 0)
1541 /* Well, this device is dead */
1542 md_error(mddev, rdev);
1543 else {
1544 atomic_add(s, &rdev->corrected_errors);
1545 printk(KERN_INFO
1546 "raid1:%s: read error corrected "
1547 "(%d sectors at %llu on %s)\n",
1548 mdname(mddev), s,
1549 (unsigned long long)(sect +
1550 rdev->data_offset),
1551 bdevname(rdev->bdev, b));
1552 }
1553 }
1554 }
1555 sectors -= s;
1556 sect += s;
1557 }
1558 }
1559
1560 static void raid1d(mddev_t *mddev)
1561 {
1562 r1bio_t *r1_bio;
1563 struct bio *bio;
1564 unsigned long flags;
1565 conf_t *conf = mddev->private;
1566 struct list_head *head = &conf->retry_list;
1567 int unplug=0;
1568 mdk_rdev_t *rdev;
1569
1570 md_check_recovery(mddev);
1571
1572 for (;;) {
1573 char b[BDEVNAME_SIZE];
1574
1575 unplug += flush_pending_writes(conf);
1576
1577 spin_lock_irqsave(&conf->device_lock, flags);
1578 if (list_empty(head)) {
1579 spin_unlock_irqrestore(&conf->device_lock, flags);
1580 break;
1581 }
1582 r1_bio = list_entry(head->prev, r1bio_t, retry_list);
1583 list_del(head->prev);
1584 conf->nr_queued--;
1585 spin_unlock_irqrestore(&conf->device_lock, flags);
1586
1587 mddev = r1_bio->mddev;
1588 conf = mddev->private;
1589 if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
1590 sync_request_write(mddev, r1_bio);
1591 unplug = 1;
1592 } else if (test_bit(R1BIO_BarrierRetry, &r1_bio->state)) {
1593 /* some requests in the r1bio were BIO_RW_BARRIER
1594 * requests which failed with -EOPNOTSUPP. Hohumm..
1595 * Better resubmit without the barrier.
1596 * We know which devices to resubmit for, because
1597 * all others have had their bios[] entry cleared.
1598 * We already have a nr_pending reference on these rdevs.
1599 */
1600 int i;
1601 const int do_sync = bio_sync(r1_bio->master_bio);
1602 clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
1603 clear_bit(R1BIO_Barrier, &r1_bio->state);
1604 for (i=0; i < conf->raid_disks; i++)
1605 if (r1_bio->bios[i])
1606 atomic_inc(&r1_bio->remaining);
1607 for (i=0; i < conf->raid_disks; i++)
1608 if (r1_bio->bios[i]) {
1609 struct bio_vec *bvec;
1610 int j;
1611
1612 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1613 /* copy pages from the failed bio, as
1614 * this might be a write-behind device */
1615 __bio_for_each_segment(bvec, bio, j, 0)
1616 bvec->bv_page = bio_iovec_idx(r1_bio->bios[i], j)->bv_page;
1617 bio_put(r1_bio->bios[i]);
1618 bio->bi_sector = r1_bio->sector +
1619 conf->mirrors[i].rdev->data_offset;
1620 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
1621 bio->bi_end_io = raid1_end_write_request;
1622 bio->bi_rw = WRITE | do_sync;
1623 bio->bi_private = r1_bio;
1624 r1_bio->bios[i] = bio;
1625 generic_make_request(bio);
1626 }
1627 } else {
1628 int disk;
1629
1630 /* we got a read error. Maybe the drive is bad. Maybe just
1631 * the block and we can fix it.
1632 * We freeze all other IO, and try reading the block from
1633 * other devices. When we find one, we re-write
1634 * and check it that fixes the read error.
1635 * This is all done synchronously while the array is
1636 * frozen
1637 */
1638 if (mddev->ro == 0) {
1639 freeze_array(conf);
1640 fix_read_error(conf, r1_bio->read_disk,
1641 r1_bio->sector,
1642 r1_bio->sectors);
1643 unfreeze_array(conf);
1644 }
1645
1646 bio = r1_bio->bios[r1_bio->read_disk];
1647 if ((disk=read_balance(conf, r1_bio)) == -1 ||
1648 disk == r1_bio->read_disk) {
1649 printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
1650 " read error for block %llu\n",
1651 bdevname(bio->bi_bdev,b),
1652 (unsigned long long)r1_bio->sector);
1653 raid_end_bio_io(r1_bio);
1654 } else {
1655 const int do_sync = bio_sync(r1_bio->master_bio);
1656 r1_bio->bios[r1_bio->read_disk] =
1657 mddev->ro ? IO_BLOCKED : NULL;
1658 r1_bio->read_disk = disk;
1659 bio_put(bio);
1660 bio = bio_clone(r1_bio->master_bio, GFP_NOIO);
1661 r1_bio->bios[r1_bio->read_disk] = bio;
1662 rdev = conf->mirrors[disk].rdev;
1663 if (printk_ratelimit())
1664 printk(KERN_ERR "raid1: %s: redirecting sector %llu to"
1665 " another mirror\n",
1666 bdevname(rdev->bdev,b),
1667 (unsigned long long)r1_bio->sector);
1668 bio->bi_sector = r1_bio->sector + rdev->data_offset;
1669 bio->bi_bdev = rdev->bdev;
1670 bio->bi_end_io = raid1_end_read_request;
1671 bio->bi_rw = READ | do_sync;
1672 bio->bi_private = r1_bio;
1673 unplug = 1;
1674 generic_make_request(bio);
1675 }
1676 }
1677 }
1678 if (unplug)
1679 unplug_slaves(mddev);
1680 }
1681
1682
1683 static int init_resync(conf_t *conf)
1684 {
1685 int buffs;
1686
1687 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
1688 BUG_ON(conf->r1buf_pool);
1689 conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free,
1690 conf->poolinfo);
1691 if (!conf->r1buf_pool)
1692 return -ENOMEM;
1693 conf->next_resync = 0;
1694 return 0;
1695 }
1696
1697 /*
1698 * perform a "sync" on one "block"
1699 *
1700 * We need to make sure that no normal I/O request - particularly write
1701 * requests - conflict with active sync requests.
1702 *
1703 * This is achieved by tracking pending requests and a 'barrier' concept
1704 * that can be installed to exclude normal IO requests.
1705 */
1706
1707 static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
1708 {
1709 conf_t *conf = mddev->private;
1710 r1bio_t *r1_bio;
1711 struct bio *bio;
1712 sector_t max_sector, nr_sectors;
1713 int disk = -1;
1714 int i;
1715 int wonly = -1;
1716 int write_targets = 0, read_targets = 0;
1717 int sync_blocks;
1718 int still_degraded = 0;
1719
1720 if (!conf->r1buf_pool)
1721 {
1722 /*
1723 printk("sync start - bitmap %p\n", mddev->bitmap);
1724 */
1725 if (init_resync(conf))
1726 return 0;
1727 }
1728
1729 max_sector = mddev->dev_sectors;
1730 if (sector_nr >= max_sector) {
1731 /* If we aborted, we need to abort the
1732 * sync on the 'current' bitmap chunk (there will
1733 * only be one in raid1 resync.
1734 * We can find the current addess in mddev->curr_resync
1735 */
1736 if (mddev->curr_resync < max_sector) /* aborted */
1737 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
1738 &sync_blocks, 1);
1739 else /* completed sync */
1740 conf->fullsync = 0;
1741
1742 bitmap_close_sync(mddev->bitmap);
1743 close_sync(conf);
1744 return 0;
1745 }
1746
1747 if (mddev->bitmap == NULL &&
1748 mddev->recovery_cp == MaxSector &&
1749 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
1750 conf->fullsync == 0) {
1751 *skipped = 1;
1752 return max_sector - sector_nr;
1753 }
1754 /* before building a request, check if we can skip these blocks..
1755 * This call the bitmap_start_sync doesn't actually record anything
1756 */
1757 if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) &&
1758 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1759 /* We can skip this block, and probably several more */
1760 *skipped = 1;
1761 return sync_blocks;
1762 }
1763 /*
1764 * If there is non-resync activity waiting for a turn,
1765 * and resync is going fast enough,
1766 * then let it though before starting on this new sync request.
1767 */
1768 if (!go_faster && conf->nr_waiting)
1769 msleep_interruptible(1000);
1770
1771 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
1772 raise_barrier(conf);
1773
1774 conf->next_resync = sector_nr;
1775
1776 r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
1777 rcu_read_lock();
1778 /*
1779 * If we get a correctably read error during resync or recovery,
1780 * we might want to read from a different device. So we
1781 * flag all drives that could conceivably be read from for READ,
1782 * and any others (which will be non-In_sync devices) for WRITE.
1783 * If a read fails, we try reading from something else for which READ
1784 * is OK.
1785 */
1786
1787 r1_bio->mddev = mddev;
1788 r1_bio->sector = sector_nr;
1789 r1_bio->state = 0;
1790 set_bit(R1BIO_IsSync, &r1_bio->state);
1791
1792 for (i=0; i < conf->raid_disks; i++) {
1793 mdk_rdev_t *rdev;
1794 bio = r1_bio->bios[i];
1795
1796 /* take from bio_init */
1797 bio->bi_next = NULL;
1798 bio->bi_flags |= 1 << BIO_UPTODATE;
1799 bio->bi_rw = READ;
1800 bio->bi_vcnt = 0;
1801 bio->bi_idx = 0;
1802 bio->bi_phys_segments = 0;
1803 bio->bi_size = 0;
1804 bio->bi_end_io = NULL;
1805 bio->bi_private = NULL;
1806
1807 rdev = rcu_dereference(conf->mirrors[i].rdev);
1808 if (rdev == NULL ||
1809 test_bit(Faulty, &rdev->flags)) {
1810 still_degraded = 1;
1811 continue;
1812 } else if (!test_bit(In_sync, &rdev->flags)) {
1813 bio->bi_rw = WRITE;
1814 bio->bi_end_io = end_sync_write;
1815 write_targets ++;
1816 } else {
1817 /* may need to read from here */
1818 bio->bi_rw = READ;
1819 bio->bi_end_io = end_sync_read;
1820 if (test_bit(WriteMostly, &rdev->flags)) {
1821 if (wonly < 0)
1822 wonly = i;
1823 } else {
1824 if (disk < 0)
1825 disk = i;
1826 }
1827 read_targets++;
1828 }
1829 atomic_inc(&rdev->nr_pending);
1830 bio->bi_sector = sector_nr + rdev->data_offset;
1831 bio->bi_bdev = rdev->bdev;
1832 bio->bi_private = r1_bio;
1833 }
1834 rcu_read_unlock();
1835 if (disk < 0)
1836 disk = wonly;
1837 r1_bio->read_disk = disk;
1838
1839 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
1840 /* extra read targets are also write targets */
1841 write_targets += read_targets-1;
1842
1843 if (write_targets == 0 || read_targets == 0) {
1844 /* There is nowhere to write, so all non-sync
1845 * drives must be failed - so we are finished
1846 */
1847 sector_t rv = max_sector - sector_nr;
1848 *skipped = 1;
1849 put_buf(r1_bio);
1850 return rv;
1851 }
1852
1853 if (max_sector > mddev->resync_max)
1854 max_sector = mddev->resync_max; /* Don't do IO beyond here */
1855 nr_sectors = 0;
1856 sync_blocks = 0;
1857 do {
1858 struct page *page;
1859 int len = PAGE_SIZE;
1860 if (sector_nr + (len>>9) > max_sector)
1861 len = (max_sector - sector_nr) << 9;
1862 if (len == 0)
1863 break;
1864 if (sync_blocks == 0) {
1865 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
1866 &sync_blocks, still_degraded) &&
1867 !conf->fullsync &&
1868 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1869 break;
1870 BUG_ON(sync_blocks < (PAGE_SIZE>>9));
1871 if (len > (sync_blocks<<9))
1872 len = sync_blocks<<9;
1873 }
1874
1875 for (i=0 ; i < conf->raid_disks; i++) {
1876 bio = r1_bio->bios[i];
1877 if (bio->bi_end_io) {
1878 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
1879 if (bio_add_page(bio, page, len, 0) == 0) {
1880 /* stop here */
1881 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
1882 while (i > 0) {
1883 i--;
1884 bio = r1_bio->bios[i];
1885 if (bio->bi_end_io==NULL)
1886 continue;
1887 /* remove last page from this bio */
1888 bio->bi_vcnt--;
1889 bio->bi_size -= len;
1890 bio->bi_flags &= ~(1<< BIO_SEG_VALID);
1891 }
1892 goto bio_full;
1893 }
1894 }
1895 }
1896 nr_sectors += len>>9;
1897 sector_nr += len>>9;
1898 sync_blocks -= (len>>9);
1899 } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
1900 bio_full:
1901 r1_bio->sectors = nr_sectors;
1902
1903 /* For a user-requested sync, we read all readable devices and do a
1904 * compare
1905 */
1906 if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
1907 atomic_set(&r1_bio->remaining, read_targets);
1908 for (i=0; i<conf->raid_disks; i++) {
1909 bio = r1_bio->bios[i];
1910 if (bio->bi_end_io == end_sync_read) {
1911 md_sync_acct(bio->bi_bdev, nr_sectors);
1912 generic_make_request(bio);
1913 }
1914 }
1915 } else {
1916 atomic_set(&r1_bio->remaining, 1);
1917 bio = r1_bio->bios[r1_bio->read_disk];
1918 md_sync_acct(bio->bi_bdev, nr_sectors);
1919 generic_make_request(bio);
1920
1921 }
1922 return nr_sectors;
1923 }
1924
1925 static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks)
1926 {
1927 if (sectors)
1928 return sectors;
1929
1930 return mddev->dev_sectors;
1931 }
1932
1933 static int run(mddev_t *mddev)
1934 {
1935 conf_t *conf;
1936 int i, j, disk_idx;
1937 mirror_info_t *disk;
1938 mdk_rdev_t *rdev;
1939
1940 if (mddev->level != 1) {
1941 printk("raid1: %s: raid level not set to mirroring (%d)\n",
1942 mdname(mddev), mddev->level);
1943 goto out;
1944 }
1945 if (mddev->reshape_position != MaxSector) {
1946 printk("raid1: %s: reshape_position set but not supported\n",
1947 mdname(mddev));
1948 goto out;
1949 }
1950 /*
1951 * copy the already verified devices into our private RAID1
1952 * bookkeeping area. [whatever we allocate in run(),
1953 * should be freed in stop()]
1954 */
1955 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
1956 mddev->private = conf;
1957 if (!conf)
1958 goto out_no_mem;
1959
1960 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
1961 GFP_KERNEL);
1962 if (!conf->mirrors)
1963 goto out_no_mem;
1964
1965 conf->tmppage = alloc_page(GFP_KERNEL);
1966 if (!conf->tmppage)
1967 goto out_no_mem;
1968
1969 conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
1970 if (!conf->poolinfo)
1971 goto out_no_mem;
1972 conf->poolinfo->mddev = mddev;
1973 conf->poolinfo->raid_disks = mddev->raid_disks;
1974 conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
1975 r1bio_pool_free,
1976 conf->poolinfo);
1977 if (!conf->r1bio_pool)
1978 goto out_no_mem;
1979
1980 spin_lock_init(&conf->device_lock);
1981 mddev->queue->queue_lock = &conf->device_lock;
1982
1983 list_for_each_entry(rdev, &mddev->disks, same_set) {
1984 disk_idx = rdev->raid_disk;
1985 if (disk_idx >= mddev->raid_disks
1986 || disk_idx < 0)
1987 continue;
1988 disk = conf->mirrors + disk_idx;
1989
1990 disk->rdev = rdev;
1991
1992 blk_queue_stack_limits(mddev->queue,
1993 rdev->bdev->bd_disk->queue);
1994 /* as we don't honour merge_bvec_fn, we must never risk
1995 * violating it, so limit ->max_sector to one PAGE, as
1996 * a one page request is never in violation.
1997 */
1998 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
1999 queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9))
2000 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
2001
2002 disk->head_position = 0;
2003 }
2004 conf->raid_disks = mddev->raid_disks;
2005 conf->mddev = mddev;
2006 INIT_LIST_HEAD(&conf->retry_list);
2007
2008 spin_lock_init(&conf->resync_lock);
2009 init_waitqueue_head(&conf->wait_barrier);
2010
2011 bio_list_init(&conf->pending_bio_list);
2012 bio_list_init(&conf->flushing_bio_list);
2013
2014
2015 mddev->degraded = 0;
2016 for (i = 0; i < conf->raid_disks; i++) {
2017
2018 disk = conf->mirrors + i;
2019
2020 if (!disk->rdev ||
2021 !test_bit(In_sync, &disk->rdev->flags)) {
2022 disk->head_position = 0;
2023 mddev->degraded++;
2024 if (disk->rdev)
2025 conf->fullsync = 1;
2026 }
2027 }
2028 if (mddev->degraded == conf->raid_disks) {
2029 printk(KERN_ERR "raid1: no operational mirrors for %s\n",
2030 mdname(mddev));
2031 goto out_free_conf;
2032 }
2033 if (conf->raid_disks - mddev->degraded == 1)
2034 mddev->recovery_cp = MaxSector;
2035
2036 /*
2037 * find the first working one and use it as a starting point
2038 * to read balancing.
2039 */
2040 for (j = 0; j < conf->raid_disks &&
2041 (!conf->mirrors[j].rdev ||
2042 !test_bit(In_sync, &conf->mirrors[j].rdev->flags)) ; j++)
2043 /* nothing */;
2044 conf->last_used = j;
2045
2046
2047 mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1");
2048 if (!mddev->thread) {
2049 printk(KERN_ERR
2050 "raid1: couldn't allocate thread for %s\n",
2051 mdname(mddev));
2052 goto out_free_conf;
2053 }
2054
2055 printk(KERN_INFO
2056 "raid1: raid set %s active with %d out of %d mirrors\n",
2057 mdname(mddev), mddev->raid_disks - mddev->degraded,
2058 mddev->raid_disks);
2059 /*
2060 * Ok, everything is just fine now
2061 */
2062 md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
2063
2064 mddev->queue->unplug_fn = raid1_unplug;
2065 mddev->queue->backing_dev_info.congested_fn = raid1_congested;
2066 mddev->queue->backing_dev_info.congested_data = mddev;
2067
2068 return 0;
2069
2070 out_no_mem:
2071 printk(KERN_ERR "raid1: couldn't allocate memory for %s\n",
2072 mdname(mddev));
2073
2074 out_free_conf:
2075 if (conf) {
2076 if (conf->r1bio_pool)
2077 mempool_destroy(conf->r1bio_pool);
2078 kfree(conf->mirrors);
2079 safe_put_page(conf->tmppage);
2080 kfree(conf->poolinfo);
2081 kfree(conf);
2082 mddev->private = NULL;
2083 }
2084 out:
2085 return -EIO;
2086 }
2087
2088 static int stop(mddev_t *mddev)
2089 {
2090 conf_t *conf = mddev->private;
2091 struct bitmap *bitmap = mddev->bitmap;
2092 int behind_wait = 0;
2093
2094 /* wait for behind writes to complete */
2095 while (bitmap && atomic_read(&bitmap->behind_writes) > 0) {
2096 behind_wait++;
2097 printk(KERN_INFO "raid1: behind writes in progress on device %s, waiting to stop (%d)\n", mdname(mddev), behind_wait);
2098 set_current_state(TASK_UNINTERRUPTIBLE);
2099 schedule_timeout(HZ); /* wait a second */
2100 /* need to kick something here to make sure I/O goes? */
2101 }
2102
2103 raise_barrier(conf);
2104 lower_barrier(conf);
2105
2106 md_unregister_thread(mddev->thread);
2107 mddev->thread = NULL;
2108 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2109 if (conf->r1bio_pool)
2110 mempool_destroy(conf->r1bio_pool);
2111 kfree(conf->mirrors);
2112 kfree(conf->poolinfo);
2113 kfree(conf);
2114 mddev->private = NULL;
2115 return 0;
2116 }
2117
2118 static int raid1_resize(mddev_t *mddev, sector_t sectors)
2119 {
2120 /* no resync is happening, and there is enough space
2121 * on all devices, so we can resize.
2122 * We need to make sure resync covers any new space.
2123 * If the array is shrinking we should possibly wait until
2124 * any io in the removed space completes, but it hardly seems
2125 * worth it.
2126 */
2127 md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0));
2128 if (mddev->array_sectors > raid1_size(mddev, sectors, 0))
2129 return -EINVAL;
2130 set_capacity(mddev->gendisk, mddev->array_sectors);
2131 mddev->changed = 1;
2132 if (sectors > mddev->dev_sectors &&
2133 mddev->recovery_cp == MaxSector) {
2134 mddev->recovery_cp = mddev->dev_sectors;
2135 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2136 }
2137 mddev->dev_sectors = sectors;
2138 mddev->resync_max_sectors = sectors;
2139 return 0;
2140 }
2141
2142 static int raid1_reshape(mddev_t *mddev)
2143 {
2144 /* We need to:
2145 * 1/ resize the r1bio_pool
2146 * 2/ resize conf->mirrors
2147 *
2148 * We allocate a new r1bio_pool if we can.
2149 * Then raise a device barrier and wait until all IO stops.
2150 * Then resize conf->mirrors and swap in the new r1bio pool.
2151 *
2152 * At the same time, we "pack" the devices so that all the missing
2153 * devices have the higher raid_disk numbers.
2154 */
2155 mempool_t *newpool, *oldpool;
2156 struct pool_info *newpoolinfo;
2157 mirror_info_t *newmirrors;
2158 conf_t *conf = mddev->private;
2159 int cnt, raid_disks;
2160 unsigned long flags;
2161 int d, d2, err;
2162
2163 /* Cannot change chunk_size, layout, or level */
2164 if (mddev->chunk_sectors != mddev->new_chunk_sectors ||
2165 mddev->layout != mddev->new_layout ||
2166 mddev->level != mddev->new_level) {
2167 mddev->new_chunk_sectors = mddev->chunk_sectors;
2168 mddev->new_layout = mddev->layout;
2169 mddev->new_level = mddev->level;
2170 return -EINVAL;
2171 }
2172
2173 err = md_allow_write(mddev);
2174 if (err)
2175 return err;
2176
2177 raid_disks = mddev->raid_disks + mddev->delta_disks;
2178
2179 if (raid_disks < conf->raid_disks) {
2180 cnt=0;
2181 for (d= 0; d < conf->raid_disks; d++)
2182 if (conf->mirrors[d].rdev)
2183 cnt++;
2184 if (cnt > raid_disks)
2185 return -EBUSY;
2186 }
2187
2188 newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL);
2189 if (!newpoolinfo)
2190 return -ENOMEM;
2191 newpoolinfo->mddev = mddev;
2192 newpoolinfo->raid_disks = raid_disks;
2193
2194 newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc,
2195 r1bio_pool_free, newpoolinfo);
2196 if (!newpool) {
2197 kfree(newpoolinfo);
2198 return -ENOMEM;
2199 }
2200 newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL);
2201 if (!newmirrors) {
2202 kfree(newpoolinfo);
2203 mempool_destroy(newpool);
2204 return -ENOMEM;
2205 }
2206
2207 raise_barrier(conf);
2208
2209 /* ok, everything is stopped */
2210 oldpool = conf->r1bio_pool;
2211 conf->r1bio_pool = newpool;
2212
2213 for (d = d2 = 0; d < conf->raid_disks; d++) {
2214 mdk_rdev_t *rdev = conf->mirrors[d].rdev;
2215 if (rdev && rdev->raid_disk != d2) {
2216 char nm[20];
2217 sprintf(nm, "rd%d", rdev->raid_disk);
2218 sysfs_remove_link(&mddev->kobj, nm);
2219 rdev->raid_disk = d2;
2220 sprintf(nm, "rd%d", rdev->raid_disk);
2221 sysfs_remove_link(&mddev->kobj, nm);
2222 if (sysfs_create_link(&mddev->kobj,
2223 &rdev->kobj, nm))
2224 printk(KERN_WARNING
2225 "md/raid1: cannot register "
2226 "%s for %s\n",
2227 nm, mdname(mddev));
2228 }
2229 if (rdev)
2230 newmirrors[d2++].rdev = rdev;
2231 }
2232 kfree(conf->mirrors);
2233 conf->mirrors = newmirrors;
2234 kfree(conf->poolinfo);
2235 conf->poolinfo = newpoolinfo;
2236
2237 spin_lock_irqsave(&conf->device_lock, flags);
2238 mddev->degraded += (raid_disks - conf->raid_disks);
2239 spin_unlock_irqrestore(&conf->device_lock, flags);
2240 conf->raid_disks = mddev->raid_disks = raid_disks;
2241 mddev->delta_disks = 0;
2242
2243 conf->last_used = 0; /* just make sure it is in-range */
2244 lower_barrier(conf);
2245
2246 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
2247 md_wakeup_thread(mddev->thread);
2248
2249 mempool_destroy(oldpool);
2250 return 0;
2251 }
2252
2253 static void raid1_quiesce(mddev_t *mddev, int state)
2254 {
2255 conf_t *conf = mddev->private;
2256
2257 switch(state) {
2258 case 1:
2259 raise_barrier(conf);
2260 break;
2261 case 0:
2262 lower_barrier(conf);
2263 break;
2264 }
2265 }
2266
2267
2268 static struct mdk_personality raid1_personality =
2269 {
2270 .name = "raid1",
2271 .level = 1,
2272 .owner = THIS_MODULE,
2273 .make_request = make_request,
2274 .run = run,
2275 .stop = stop,
2276 .status = status,
2277 .error_handler = error,
2278 .hot_add_disk = raid1_add_disk,
2279 .hot_remove_disk= raid1_remove_disk,
2280 .spare_active = raid1_spare_active,
2281 .sync_request = sync_request,
2282 .resize = raid1_resize,
2283 .size = raid1_size,
2284 .check_reshape = raid1_reshape,
2285 .quiesce = raid1_quiesce,
2286 };
2287
2288 static int __init raid_init(void)
2289 {
2290 return register_md_personality(&raid1_personality);
2291 }
2292
2293 static void raid_exit(void)
2294 {
2295 unregister_md_personality(&raid1_personality);
2296 }
2297
2298 module_init(raid_init);
2299 module_exit(raid_exit);
2300 MODULE_LICENSE("GPL");
2301 MODULE_ALIAS("md-personality-3"); /* RAID1 */
2302 MODULE_ALIAS("md-raid1");
2303 MODULE_ALIAS("md-level-1");
kernel source for telekom puls (alcatel/mediatek)