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1/*
2 * raid10.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 2000-2004 Neil Brown
5 *
6 * RAID-10 support for md.
7 *
8 * Base on code in raid1.c. See raid1.c for further copyright information.
9 *
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
14 * any later version.
15 *
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#include <linux/slab.h>
22#include <linux/delay.h>
23#include <linux/blkdev.h>
24#include <linux/seq_file.h>
25#include <linux/ratelimit.h>
26#include "md.h"
27#include "raid10.h"
28#include "raid0.h"
29#include "bitmap.h"
30
31/*
32 * RAID10 provides a combination of RAID0 and RAID1 functionality.
33 * The layout of data is defined by
34 * chunk_size
35 * raid_disks
36 * near_copies (stored in low byte of layout)
37 * far_copies (stored in second byte of layout)
38 * far_offset (stored in bit 16 of layout )
39 *
40 * The data to be stored is divided into chunks using chunksize.
41 * Each device is divided into far_copies sections.
42 * In each section, chunks are laid out in a style similar to raid0, but
43 * near_copies copies of each chunk is stored (each on a different drive).
44 * The starting device for each section is offset near_copies from the starting
45 * device of the previous section.
46 * Thus they are (near_copies*far_copies) of each chunk, and each is on a different
47 * drive.
48 * near_copies and far_copies must be at least one, and their product is at most
49 * raid_disks.
50 *
51 * If far_offset is true, then the far_copies are handled a bit differently.
52 * The copies are still in different stripes, but instead of be very far apart
53 * on disk, there are adjacent stripes.
54 */
55
56/*
57 * Number of guaranteed r10bios in case of extreme VM load:
58 */
59#define NR_RAID10_BIOS 256
60
61static void allow_barrier(conf_t *conf);
62static void lower_barrier(conf_t *conf);
63
64static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
65{
66 conf_t *conf = data;
67 int size = offsetof(struct r10bio_s, devs[conf->copies]);
68
69 /* allocate a r10bio with room for raid_disks entries in the bios array */
70 return kzalloc(size, gfp_flags);
71}
72
73static void r10bio_pool_free(void *r10_bio, void *data)
74{
75 kfree(r10_bio);
76}
77
78/* Maximum size of each resync request */
79#define RESYNC_BLOCK_SIZE (64*1024)
80#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
81/* amount of memory to reserve for resync requests */
82#define RESYNC_WINDOW (1024*1024)
83/* maximum number of concurrent requests, memory permitting */
84#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
85
86/*
87 * When performing a resync, we need to read and compare, so
88 * we need as many pages are there are copies.
89 * When performing a recovery, we need 2 bios, one for read,
90 * one for write (we recover only one drive per r10buf)
91 *
92 */
93static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
94{
95 conf_t *conf = data;
96 struct page *page;
97 r10bio_t *r10_bio;
98 struct bio *bio;
99 int i, j;
100 int nalloc;
101
102 r10_bio = r10bio_pool_alloc(gfp_flags, conf);
103 if (!r10_bio)
104 return NULL;
105
106 if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
107 nalloc = conf->copies; /* resync */
108 else
109 nalloc = 2; /* recovery */
110
111 /*
112 * Allocate bios.
113 */
114 for (j = nalloc ; j-- ; ) {
115 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
116 if (!bio)
117 goto out_free_bio;
118 r10_bio->devs[j].bio = bio;
119 }
120 /*
121 * Allocate RESYNC_PAGES data pages and attach them
122 * where needed.
123 */
124 for (j = 0 ; j < nalloc; j++) {
125 bio = r10_bio->devs[j].bio;
126 for (i = 0; i < RESYNC_PAGES; i++) {
127 if (j == 1 && !test_bit(MD_RECOVERY_SYNC,
128 &conf->mddev->recovery)) {
129 /* we can share bv_page's during recovery */
130 struct bio *rbio = r10_bio->devs[0].bio;
131 page = rbio->bi_io_vec[i].bv_page;
132 get_page(page);
133 } else
134 page = alloc_page(gfp_flags);
135 if (unlikely(!page))
136 goto out_free_pages;
137
138 bio->bi_io_vec[i].bv_page = page;
139 }
140 }
141
142 return r10_bio;
143
144out_free_pages:
145 for ( ; i > 0 ; i--)
146 safe_put_page(bio->bi_io_vec[i-1].bv_page);
147 while (j--)
148 for (i = 0; i < RESYNC_PAGES ; i++)
149 safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
150 j = -1;
151out_free_bio:
152 while ( ++j < nalloc )
153 bio_put(r10_bio->devs[j].bio);
154 r10bio_pool_free(r10_bio, conf);
155 return NULL;
156}
157
158static void r10buf_pool_free(void *__r10_bio, void *data)
159{
160 int i;
161 conf_t *conf = data;
162 r10bio_t *r10bio = __r10_bio;
163 int j;
164
165 for (j=0; j < conf->copies; j++) {
166 struct bio *bio = r10bio->devs[j].bio;
167 if (bio) {
168 for (i = 0; i < RESYNC_PAGES; i++) {
169 safe_put_page(bio->bi_io_vec[i].bv_page);
170 bio->bi_io_vec[i].bv_page = NULL;
171 }
172 bio_put(bio);
173 }
174 }
175 r10bio_pool_free(r10bio, conf);
176}
177
178static void put_all_bios(conf_t *conf, r10bio_t *r10_bio)
179{
180 int i;
181
182 for (i = 0; i < conf->copies; i++) {
183 struct bio **bio = & r10_bio->devs[i].bio;
184 if (!BIO_SPECIAL(*bio))
185 bio_put(*bio);
186 *bio = NULL;
187 }
188}
189
190static void free_r10bio(r10bio_t *r10_bio)
191{
192 conf_t *conf = r10_bio->mddev->private;
193
194 put_all_bios(conf, r10_bio);
195 mempool_free(r10_bio, conf->r10bio_pool);
196}
197
198static void put_buf(r10bio_t *r10_bio)
199{
200 conf_t *conf = r10_bio->mddev->private;
201
202 mempool_free(r10_bio, conf->r10buf_pool);
203
204 lower_barrier(conf);
205}
206
207static void reschedule_retry(r10bio_t *r10_bio)
208{
209 unsigned long flags;
210 mddev_t *mddev = r10_bio->mddev;
211 conf_t *conf = mddev->private;
212
213 spin_lock_irqsave(&conf->device_lock, flags);
214 list_add(&r10_bio->retry_list, &conf->retry_list);
215 conf->nr_queued ++;
216 spin_unlock_irqrestore(&conf->device_lock, flags);
217
218 /* wake up frozen array... */
219 wake_up(&conf->wait_barrier);
220
221 md_wakeup_thread(mddev->thread);
222}
223
224/*
225 * raid_end_bio_io() is called when we have finished servicing a mirrored
226 * operation and are ready to return a success/failure code to the buffer
227 * cache layer.
228 */
229static void raid_end_bio_io(r10bio_t *r10_bio)
230{
231 struct bio *bio = r10_bio->master_bio;
232 int done;
233 conf_t *conf = r10_bio->mddev->private;
234
235 if (bio->bi_phys_segments) {
236 unsigned long flags;
237 spin_lock_irqsave(&conf->device_lock, flags);
238 bio->bi_phys_segments--;
239 done = (bio->bi_phys_segments == 0);
240 spin_unlock_irqrestore(&conf->device_lock, flags);
241 } else
242 done = 1;
243 if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
244 clear_bit(BIO_UPTODATE, &bio->bi_flags);
245 if (done) {
246 bio_endio(bio, 0);
247 /*
248 * Wake up any possible resync thread that waits for the device
249 * to go idle.
250 */
251 allow_barrier(conf);
252 }
253 free_r10bio(r10_bio);
254}
255
256/*
257 * Update disk head position estimator based on IRQ completion info.
258 */
259static inline void update_head_pos(int slot, r10bio_t *r10_bio)
260{
261 conf_t *conf = r10_bio->mddev->private;
262
263 conf->mirrors[r10_bio->devs[slot].devnum].head_position =
264 r10_bio->devs[slot].addr + (r10_bio->sectors);
265}
266
267/*
268 * Find the disk number which triggered given bio
269 */
270static int find_bio_disk(conf_t *conf, r10bio_t *r10_bio,
271 struct bio *bio, int *slotp)
272{
273 int slot;
274
275 for (slot = 0; slot < conf->copies; slot++)
276 if (r10_bio->devs[slot].bio == bio)
277 break;
278
279 BUG_ON(slot == conf->copies);
280 update_head_pos(slot, r10_bio);
281
282 if (slotp)
283 *slotp = slot;
284 return r10_bio->devs[slot].devnum;
285}
286
287static void raid10_end_read_request(struct bio *bio, int error)
288{
289 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
290 r10bio_t *r10_bio = bio->bi_private;
291 int slot, dev;
292 conf_t *conf = r10_bio->mddev->private;
293
294
295 slot = r10_bio->read_slot;
296 dev = r10_bio->devs[slot].devnum;
297 /*
298 * this branch is our 'one mirror IO has finished' event handler:
299 */
300 update_head_pos(slot, r10_bio);
301
302 if (uptodate) {
303 /*
304 * Set R10BIO_Uptodate in our master bio, so that
305 * we will return a good error code to the higher
306 * levels even if IO on some other mirrored buffer fails.
307 *
308 * The 'master' represents the composite IO operation to
309 * user-side. So if something waits for IO, then it will
310 * wait for the 'master' bio.
311 */
312 set_bit(R10BIO_Uptodate, &r10_bio->state);
313 raid_end_bio_io(r10_bio);
314 rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
315 } else {
316 /*
317 * oops, read error - keep the refcount on the rdev
318 */
319 char b[BDEVNAME_SIZE];
320 printk_ratelimited(KERN_ERR
321 "md/raid10:%s: %s: rescheduling sector %llu\n",
322 mdname(conf->mddev),
323 bdevname(conf->mirrors[dev].rdev->bdev, b),
324 (unsigned long long)r10_bio->sector);
325 set_bit(R10BIO_ReadError, &r10_bio->state);
326 reschedule_retry(r10_bio);
327 }
328}
329
330static void close_write(r10bio_t *r10_bio)
331{
332 /* clear the bitmap if all writes complete successfully */
333 bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
334 r10_bio->sectors,
335 !test_bit(R10BIO_Degraded, &r10_bio->state),
336 0);
337 md_write_end(r10_bio->mddev);
338}
339
340static void one_write_done(r10bio_t *r10_bio)
341{
342 if (atomic_dec_and_test(&r10_bio->remaining)) {
343 if (test_bit(R10BIO_WriteError, &r10_bio->state))
344 reschedule_retry(r10_bio);
345 else {
346 close_write(r10_bio);
347 if (test_bit(R10BIO_MadeGood, &r10_bio->state))
348 reschedule_retry(r10_bio);
349 else
350 raid_end_bio_io(r10_bio);
351 }
352 }
353}
354
355static void raid10_end_write_request(struct bio *bio, int error)
356{
357 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
358 r10bio_t *r10_bio = bio->bi_private;
359 int dev;
360 int dec_rdev = 1;
361 conf_t *conf = r10_bio->mddev->private;
362 int slot;
363
364 dev = find_bio_disk(conf, r10_bio, bio, &slot);
365
366 /*
367 * this branch is our 'one mirror IO has finished' event handler:
368 */
369 if (!uptodate) {
370 set_bit(WriteErrorSeen, &conf->mirrors[dev].rdev->flags);
371 set_bit(R10BIO_WriteError, &r10_bio->state);
372 dec_rdev = 0;
373 } else {
374 /*
375 * Set R10BIO_Uptodate in our master bio, so that
376 * we will return a good error code for to the higher
377 * levels even if IO on some other mirrored buffer fails.
378 *
379 * The 'master' represents the composite IO operation to
380 * user-side. So if something waits for IO, then it will
381 * wait for the 'master' bio.
382 */
383 sector_t first_bad;
384 int bad_sectors;
385
386 set_bit(R10BIO_Uptodate, &r10_bio->state);
387
388 /* Maybe we can clear some bad blocks. */
389 if (is_badblock(conf->mirrors[dev].rdev,
390 r10_bio->devs[slot].addr,
391 r10_bio->sectors,
392 &first_bad, &bad_sectors)) {
393 bio_put(bio);
394 r10_bio->devs[slot].bio = IO_MADE_GOOD;
395 dec_rdev = 0;
396 set_bit(R10BIO_MadeGood, &r10_bio->state);
397 }
398 }
399
400 /*
401 *
402 * Let's see if all mirrored write operations have finished
403 * already.
404 */
405 one_write_done(r10_bio);
406 if (dec_rdev)
407 rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
408}
409
410
411/*
412 * RAID10 layout manager
413 * As well as the chunksize and raid_disks count, there are two
414 * parameters: near_copies and far_copies.
415 * near_copies * far_copies must be <= raid_disks.
416 * Normally one of these will be 1.
417 * If both are 1, we get raid0.
418 * If near_copies == raid_disks, we get raid1.
419 *
420 * Chunks are laid out in raid0 style with near_copies copies of the
421 * first chunk, followed by near_copies copies of the next chunk and
422 * so on.
423 * If far_copies > 1, then after 1/far_copies of the array has been assigned
424 * as described above, we start again with a device offset of near_copies.
425 * So we effectively have another copy of the whole array further down all
426 * the drives, but with blocks on different drives.
427 * With this layout, and block is never stored twice on the one device.
428 *
429 * raid10_find_phys finds the sector offset of a given virtual sector
430 * on each device that it is on.
431 *
432 * raid10_find_virt does the reverse mapping, from a device and a
433 * sector offset to a virtual address
434 */
435
436static void raid10_find_phys(conf_t *conf, r10bio_t *r10bio)
437{
438 int n,f;
439 sector_t sector;
440 sector_t chunk;
441 sector_t stripe;
442 int dev;
443
444 int slot = 0;
445
446 /* now calculate first sector/dev */
447 chunk = r10bio->sector >> conf->chunk_shift;
448 sector = r10bio->sector & conf->chunk_mask;
449
450 chunk *= conf->near_copies;
451 stripe = chunk;
452 dev = sector_div(stripe, conf->raid_disks);
453 if (conf->far_offset)
454 stripe *= conf->far_copies;
455
456 sector += stripe << conf->chunk_shift;
457
458 /* and calculate all the others */
459 for (n=0; n < conf->near_copies; n++) {
460 int d = dev;
461 sector_t s = sector;
462 r10bio->devs[slot].addr = sector;
463 r10bio->devs[slot].devnum = d;
464 slot++;
465
466 for (f = 1; f < conf->far_copies; f++) {
467 d += conf->near_copies;
468 if (d >= conf->raid_disks)
469 d -= conf->raid_disks;
470 s += conf->stride;
471 r10bio->devs[slot].devnum = d;
472 r10bio->devs[slot].addr = s;
473 slot++;
474 }
475 dev++;
476 if (dev >= conf->raid_disks) {
477 dev = 0;
478 sector += (conf->chunk_mask + 1);
479 }
480 }
481 BUG_ON(slot != conf->copies);
482}
483
484static sector_t raid10_find_virt(conf_t *conf, sector_t sector, int dev)
485{
486 sector_t offset, chunk, vchunk;
487
488 offset = sector & conf->chunk_mask;
489 if (conf->far_offset) {
490 int fc;
491 chunk = sector >> conf->chunk_shift;
492 fc = sector_div(chunk, conf->far_copies);
493 dev -= fc * conf->near_copies;
494 if (dev < 0)
495 dev += conf->raid_disks;
496 } else {
497 while (sector >= conf->stride) {
498 sector -= conf->stride;
499 if (dev < conf->near_copies)
500 dev += conf->raid_disks - conf->near_copies;
501 else
502 dev -= conf->near_copies;
503 }
504 chunk = sector >> conf->chunk_shift;
505 }
506 vchunk = chunk * conf->raid_disks + dev;
507 sector_div(vchunk, conf->near_copies);
508 return (vchunk << conf->chunk_shift) + offset;
509}
510
511/**
512 * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
513 * @q: request queue
514 * @bvm: properties of new bio
515 * @biovec: the request that could be merged to it.
516 *
517 * Return amount of bytes we can accept at this offset
518 * If near_copies == raid_disk, there are no striping issues,
519 * but in that case, the function isn't called at all.
520 */
521static int raid10_mergeable_bvec(struct request_queue *q,
522 struct bvec_merge_data *bvm,
523 struct bio_vec *biovec)
524{
525 mddev_t *mddev = q->queuedata;
526 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
527 int max;
528 unsigned int chunk_sectors = mddev->chunk_sectors;
529 unsigned int bio_sectors = bvm->bi_size >> 9;
530
531 max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9;
532 if (max < 0) max = 0; /* bio_add cannot handle a negative return */
533 if (max <= biovec->bv_len && bio_sectors == 0)
534 return biovec->bv_len;
535 else
536 return max;
537}
538
539/*
540 * This routine returns the disk from which the requested read should
541 * be done. There is a per-array 'next expected sequential IO' sector
542 * number - if this matches on the next IO then we use the last disk.
543 * There is also a per-disk 'last know head position' sector that is
544 * maintained from IRQ contexts, both the normal and the resync IO
545 * completion handlers update this position correctly. If there is no
546 * perfect sequential match then we pick the disk whose head is closest.
547 *
548 * If there are 2 mirrors in the same 2 devices, performance degrades
549 * because position is mirror, not device based.
550 *
551 * The rdev for the device selected will have nr_pending incremented.
552 */
553
554/*
555 * FIXME: possibly should rethink readbalancing and do it differently
556 * depending on near_copies / far_copies geometry.
557 */
558static int read_balance(conf_t *conf, r10bio_t *r10_bio, int *max_sectors)
559{
560 const sector_t this_sector = r10_bio->sector;
561 int disk, slot;
562 int sectors = r10_bio->sectors;
563 int best_good_sectors;
564 sector_t new_distance, best_dist;
565 mdk_rdev_t *rdev;
566 int do_balance;
567 int best_slot;
568
569 raid10_find_phys(conf, r10_bio);
570 rcu_read_lock();
571retry:
572 sectors = r10_bio->sectors;
573 best_slot = -1;
574 best_dist = MaxSector;
575 best_good_sectors = 0;
576 do_balance = 1;
577 /*
578 * Check if we can balance. We can balance on the whole
579 * device if no resync is going on (recovery is ok), or below
580 * the resync window. We take the first readable disk when
581 * above the resync window.
582 */
583 if (conf->mddev->recovery_cp < MaxSector
584 && (this_sector + sectors >= conf->next_resync))
585 do_balance = 0;
586
587 for (slot = 0; slot < conf->copies ; slot++) {
588 sector_t first_bad;
589 int bad_sectors;
590 sector_t dev_sector;
591
592 if (r10_bio->devs[slot].bio == IO_BLOCKED)
593 continue;
594 disk = r10_bio->devs[slot].devnum;
595 rdev = rcu_dereference(conf->mirrors[disk].rdev);
596 if (rdev == NULL)
597 continue;
598 if (!test_bit(In_sync, &rdev->flags))
599 continue;
600
601 dev_sector = r10_bio->devs[slot].addr;
602 if (is_badblock(rdev, dev_sector, sectors,
603 &first_bad, &bad_sectors)) {
604 if (best_dist < MaxSector)
605 /* Already have a better slot */
606 continue;
607 if (first_bad <= dev_sector) {
608 /* Cannot read here. If this is the
609 * 'primary' device, then we must not read
610 * beyond 'bad_sectors' from another device.
611 */
612 bad_sectors -= (dev_sector - first_bad);
613 if (!do_balance && sectors > bad_sectors)
614 sectors = bad_sectors;
615 if (best_good_sectors > sectors)
616 best_good_sectors = sectors;
617 } else {
618 sector_t good_sectors =
619 first_bad - dev_sector;
620 if (good_sectors > best_good_sectors) {
621 best_good_sectors = good_sectors;
622 best_slot = slot;
623 }
624 if (!do_balance)
625 /* Must read from here */
626 break;
627 }
628 continue;
629 } else
630 best_good_sectors = sectors;
631
632 if (!do_balance)
633 break;
634
635 /* This optimisation is debatable, and completely destroys
636 * sequential read speed for 'far copies' arrays. So only
637 * keep it for 'near' arrays, and review those later.
638 */
639 if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending))
640 break;
641
642 /* for far > 1 always use the lowest address */
643 if (conf->far_copies > 1)
644 new_distance = r10_bio->devs[slot].addr;
645 else
646 new_distance = abs(r10_bio->devs[slot].addr -
647 conf->mirrors[disk].head_position);
648 if (new_distance < best_dist) {
649 best_dist = new_distance;
650 best_slot = slot;
651 }
652 }
653 if (slot == conf->copies)
654 slot = best_slot;
655
656 if (slot >= 0) {
657 disk = r10_bio->devs[slot].devnum;
658 rdev = rcu_dereference(conf->mirrors[disk].rdev);
659 if (!rdev)
660 goto retry;
661 atomic_inc(&rdev->nr_pending);
662 if (test_bit(Faulty, &rdev->flags)) {
663 /* Cannot risk returning a device that failed
664 * before we inc'ed nr_pending
665 */
666 rdev_dec_pending(rdev, conf->mddev);
667 goto retry;
668 }
669 r10_bio->read_slot = slot;
670 } else
671 disk = -1;
672 rcu_read_unlock();
673 *max_sectors = best_good_sectors;
674
675 return disk;
676}
677
678static int raid10_congested(void *data, int bits)
679{
680 mddev_t *mddev = data;
681 conf_t *conf = mddev->private;
682 int i, ret = 0;
683
684 if (mddev_congested(mddev, bits))
685 return 1;
686 rcu_read_lock();
687 for (i = 0; i < conf->raid_disks && ret == 0; i++) {
688 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
689 if (rdev && !test_bit(Faulty, &rdev->flags)) {
690 struct request_queue *q = bdev_get_queue(rdev->bdev);
691
692 ret |= bdi_congested(&q->backing_dev_info, bits);
693 }
694 }
695 rcu_read_unlock();
696 return ret;
697}
698
699static void flush_pending_writes(conf_t *conf)
700{
701 /* Any writes that have been queued but are awaiting
702 * bitmap updates get flushed here.
703 */
704 spin_lock_irq(&conf->device_lock);
705
706 if (conf->pending_bio_list.head) {
707 struct bio *bio;
708 bio = bio_list_get(&conf->pending_bio_list);
709 spin_unlock_irq(&conf->device_lock);
710 /* flush any pending bitmap writes to disk
711 * before proceeding w/ I/O */
712 bitmap_unplug(conf->mddev->bitmap);
713
714 while (bio) { /* submit pending writes */
715 struct bio *next = bio->bi_next;
716 bio->bi_next = NULL;
717 generic_make_request(bio);
718 bio = next;
719 }
720 } else
721 spin_unlock_irq(&conf->device_lock);
722}
723
724/* Barriers....
725 * Sometimes we need to suspend IO while we do something else,
726 * either some resync/recovery, or reconfigure the array.
727 * To do this we raise a 'barrier'.
728 * The 'barrier' is a counter that can be raised multiple times
729 * to count how many activities are happening which preclude
730 * normal IO.
731 * We can only raise the barrier if there is no pending IO.
732 * i.e. if nr_pending == 0.
733 * We choose only to raise the barrier if no-one is waiting for the
734 * barrier to go down. This means that as soon as an IO request
735 * is ready, no other operations which require a barrier will start
736 * until the IO request has had a chance.
737 *
738 * So: regular IO calls 'wait_barrier'. When that returns there
739 * is no backgroup IO happening, It must arrange to call
740 * allow_barrier when it has finished its IO.
741 * backgroup IO calls must call raise_barrier. Once that returns
742 * there is no normal IO happeing. It must arrange to call
743 * lower_barrier when the particular background IO completes.
744 */
745
746static void raise_barrier(conf_t *conf, int force)
747{
748 BUG_ON(force && !conf->barrier);
749 spin_lock_irq(&conf->resync_lock);
750
751 /* Wait until no block IO is waiting (unless 'force') */
752 wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
753 conf->resync_lock, );
754
755 /* block any new IO from starting */
756 conf->barrier++;
757
758 /* Now wait for all pending IO to complete */
759 wait_event_lock_irq(conf->wait_barrier,
760 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
761 conf->resync_lock, );
762
763 spin_unlock_irq(&conf->resync_lock);
764}
765
766static void lower_barrier(conf_t *conf)
767{
768 unsigned long flags;
769 spin_lock_irqsave(&conf->resync_lock, flags);
770 conf->barrier--;
771 spin_unlock_irqrestore(&conf->resync_lock, flags);
772 wake_up(&conf->wait_barrier);
773}
774
775static void wait_barrier(conf_t *conf)
776{
777 spin_lock_irq(&conf->resync_lock);
778 if (conf->barrier) {
779 conf->nr_waiting++;
780 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
781 conf->resync_lock,
782 );
783 conf->nr_waiting--;
784 }
785 conf->nr_pending++;
786 spin_unlock_irq(&conf->resync_lock);
787}
788
789static void allow_barrier(conf_t *conf)
790{
791 unsigned long flags;
792 spin_lock_irqsave(&conf->resync_lock, flags);
793 conf->nr_pending--;
794 spin_unlock_irqrestore(&conf->resync_lock, flags);
795 wake_up(&conf->wait_barrier);
796}
797
798static void freeze_array(conf_t *conf)
799{
800 /* stop syncio and normal IO and wait for everything to
801 * go quiet.
802 * We increment barrier and nr_waiting, and then
803 * wait until nr_pending match nr_queued+1
804 * This is called in the context of one normal IO request
805 * that has failed. Thus any sync request that might be pending
806 * will be blocked by nr_pending, and we need to wait for
807 * pending IO requests to complete or be queued for re-try.
808 * Thus the number queued (nr_queued) plus this request (1)
809 * must match the number of pending IOs (nr_pending) before
810 * we continue.
811 */
812 spin_lock_irq(&conf->resync_lock);
813 conf->barrier++;
814 conf->nr_waiting++;
815 wait_event_lock_irq(conf->wait_barrier,
816 conf->nr_pending == conf->nr_queued+1,
817 conf->resync_lock,
818 flush_pending_writes(conf));
819
820 spin_unlock_irq(&conf->resync_lock);
821}
822
823static void unfreeze_array(conf_t *conf)
824{
825 /* reverse the effect of the freeze */
826 spin_lock_irq(&conf->resync_lock);
827 conf->barrier--;
828 conf->nr_waiting--;
829 wake_up(&conf->wait_barrier);
830 spin_unlock_irq(&conf->resync_lock);
831}
832
833static int make_request(mddev_t *mddev, struct bio * bio)
834{
835 conf_t *conf = mddev->private;
836 mirror_info_t *mirror;
837 r10bio_t *r10_bio;
838 struct bio *read_bio;
839 int i;
840 int chunk_sects = conf->chunk_mask + 1;
841 const int rw = bio_data_dir(bio);
842 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
843 const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
844 unsigned long flags;
845 mdk_rdev_t *blocked_rdev;
846 int plugged;
847 int sectors_handled;
848 int max_sectors;
849
850 if (unlikely(bio->bi_rw & REQ_FLUSH)) {
851 md_flush_request(mddev, bio);
852 return 0;
853 }
854
855 /* If this request crosses a chunk boundary, we need to
856 * split it. This will only happen for 1 PAGE (or less) requests.
857 */
858 if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9)
859 > chunk_sects &&
860 conf->near_copies < conf->raid_disks)) {
861 struct bio_pair *bp;
862 /* Sanity check -- queue functions should prevent this happening */
863 if (bio->bi_vcnt != 1 ||
864 bio->bi_idx != 0)
865 goto bad_map;
866 /* This is a one page bio that upper layers
867 * refuse to split for us, so we need to split it.
868 */
869 bp = bio_split(bio,
870 chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
871
872 /* Each of these 'make_request' calls will call 'wait_barrier'.
873 * If the first succeeds but the second blocks due to the resync
874 * thread raising the barrier, we will deadlock because the
875 * IO to the underlying device will be queued in generic_make_request
876 * and will never complete, so will never reduce nr_pending.
877 * So increment nr_waiting here so no new raise_barriers will
878 * succeed, and so the second wait_barrier cannot block.
879 */
880 spin_lock_irq(&conf->resync_lock);
881 conf->nr_waiting++;
882 spin_unlock_irq(&conf->resync_lock);
883
884 if (make_request(mddev, &bp->bio1))
885 generic_make_request(&bp->bio1);
886 if (make_request(mddev, &bp->bio2))
887 generic_make_request(&bp->bio2);
888
889 spin_lock_irq(&conf->resync_lock);
890 conf->nr_waiting--;
891 wake_up(&conf->wait_barrier);
892 spin_unlock_irq(&conf->resync_lock);
893
894 bio_pair_release(bp);
895 return 0;
896 bad_map:
897 printk("md/raid10:%s: make_request bug: can't convert block across chunks"
898 " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2,
899 (unsigned long long)bio->bi_sector, bio->bi_size >> 10);
900
901 bio_io_error(bio);
902 return 0;
903 }
904
905 md_write_start(mddev, bio);
906
907 /*
908 * Register the new request and wait if the reconstruction
909 * thread has put up a bar for new requests.
910 * Continue immediately if no resync is active currently.
911 */
912 wait_barrier(conf);
913
914 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
915
916 r10_bio->master_bio = bio;
917 r10_bio->sectors = bio->bi_size >> 9;
918
919 r10_bio->mddev = mddev;
920 r10_bio->sector = bio->bi_sector;
921 r10_bio->state = 0;
922
923 /* We might need to issue multiple reads to different
924 * devices if there are bad blocks around, so we keep
925 * track of the number of reads in bio->bi_phys_segments.
926 * If this is 0, there is only one r10_bio and no locking
927 * will be needed when the request completes. If it is
928 * non-zero, then it is the number of not-completed requests.
929 */
930 bio->bi_phys_segments = 0;
931 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
932
933 if (rw == READ) {
934 /*
935 * read balancing logic:
936 */
937 int disk;
938 int slot;
939
940read_again:
941 disk = read_balance(conf, r10_bio, &max_sectors);
942 slot = r10_bio->read_slot;
943 if (disk < 0) {
944 raid_end_bio_io(r10_bio);
945 return 0;
946 }
947 mirror = conf->mirrors + disk;
948
949 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
950 md_trim_bio(read_bio, r10_bio->sector - bio->bi_sector,
951 max_sectors);
952
953 r10_bio->devs[slot].bio = read_bio;
954
955 read_bio->bi_sector = r10_bio->devs[slot].addr +
956 mirror->rdev->data_offset;
957 read_bio->bi_bdev = mirror->rdev->bdev;
958 read_bio->bi_end_io = raid10_end_read_request;
959 read_bio->bi_rw = READ | do_sync;
960 read_bio->bi_private = r10_bio;
961
962 if (max_sectors < r10_bio->sectors) {
963 /* Could not read all from this device, so we will
964 * need another r10_bio.
965 */
966 sectors_handled = (r10_bio->sectors + max_sectors
967 - bio->bi_sector);
968 r10_bio->sectors = max_sectors;
969 spin_lock_irq(&conf->device_lock);
970 if (bio->bi_phys_segments == 0)
971 bio->bi_phys_segments = 2;
972 else
973 bio->bi_phys_segments++;
974 spin_unlock(&conf->device_lock);
975 /* Cannot call generic_make_request directly
976 * as that will be queued in __generic_make_request
977 * and subsequent mempool_alloc might block
978 * waiting for it. so hand bio over to raid10d.
979 */
980 reschedule_retry(r10_bio);
981
982 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
983
984 r10_bio->master_bio = bio;
985 r10_bio->sectors = ((bio->bi_size >> 9)
986 - sectors_handled);
987 r10_bio->state = 0;
988 r10_bio->mddev = mddev;
989 r10_bio->sector = bio->bi_sector + sectors_handled;
990 goto read_again;
991 } else
992 generic_make_request(read_bio);
993 return 0;
994 }
995
996 /*
997 * WRITE:
998 */
999 /* first select target devices under rcu_lock and
1000 * inc refcount on their rdev. Record them by setting
1001 * bios[x] to bio
1002 * If there are known/acknowledged bad blocks on any device
1003 * on which we have seen a write error, we want to avoid
1004 * writing to those blocks. This potentially requires several
1005 * writes to write around the bad blocks. Each set of writes
1006 * gets its own r10_bio with a set of bios attached. The number
1007 * of r10_bios is recored in bio->bi_phys_segments just as with
1008 * the read case.
1009 */
1010 plugged = mddev_check_plugged(mddev);
1011
1012 raid10_find_phys(conf, r10_bio);
1013retry_write:
1014 blocked_rdev = NULL;
1015 rcu_read_lock();
1016 max_sectors = r10_bio->sectors;
1017
1018 for (i = 0; i < conf->copies; i++) {
1019 int d = r10_bio->devs[i].devnum;
1020 mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev);
1021 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1022 atomic_inc(&rdev->nr_pending);
1023 blocked_rdev = rdev;
1024 break;
1025 }
1026 r10_bio->devs[i].bio = NULL;
1027 if (!rdev || test_bit(Faulty, &rdev->flags)) {
1028 set_bit(R10BIO_Degraded, &r10_bio->state);
1029 continue;
1030 }
1031 if (test_bit(WriteErrorSeen, &rdev->flags)) {
1032 sector_t first_bad;
1033 sector_t dev_sector = r10_bio->devs[i].addr;
1034 int bad_sectors;
1035 int is_bad;
1036
1037 is_bad = is_badblock(rdev, dev_sector,
1038 max_sectors,
1039 &first_bad, &bad_sectors);
1040 if (is_bad < 0) {
1041 /* Mustn't write here until the bad block
1042 * is acknowledged
1043 */
1044 atomic_inc(&rdev->nr_pending);
1045 set_bit(BlockedBadBlocks, &rdev->flags);
1046 blocked_rdev = rdev;
1047 break;
1048 }
1049 if (is_bad && first_bad <= dev_sector) {
1050 /* Cannot write here at all */
1051 bad_sectors -= (dev_sector - first_bad);
1052 if (bad_sectors < max_sectors)
1053 /* Mustn't write more than bad_sectors
1054 * to other devices yet
1055 */
1056 max_sectors = bad_sectors;
1057 /* We don't set R10BIO_Degraded as that
1058 * only applies if the disk is missing,
1059 * so it might be re-added, and we want to
1060 * know to recover this chunk.
1061 * In this case the device is here, and the
1062 * fact that this chunk is not in-sync is
1063 * recorded in the bad block log.
1064 */
1065 continue;
1066 }
1067 if (is_bad) {
1068 int good_sectors = first_bad - dev_sector;
1069 if (good_sectors < max_sectors)
1070 max_sectors = good_sectors;
1071 }
1072 }
1073 r10_bio->devs[i].bio = bio;
1074 atomic_inc(&rdev->nr_pending);
1075 }
1076 rcu_read_unlock();
1077
1078 if (unlikely(blocked_rdev)) {
1079 /* Have to wait for this device to get unblocked, then retry */
1080 int j;
1081 int d;
1082
1083 for (j = 0; j < i; j++)
1084 if (r10_bio->devs[j].bio) {
1085 d = r10_bio->devs[j].devnum;
1086 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
1087 }
1088 allow_barrier(conf);
1089 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1090 wait_barrier(conf);
1091 goto retry_write;
1092 }
1093
1094 if (max_sectors < r10_bio->sectors) {
1095 /* We are splitting this into multiple parts, so
1096 * we need to prepare for allocating another r10_bio.
1097 */
1098 r10_bio->sectors = max_sectors;
1099 spin_lock_irq(&conf->device_lock);
1100 if (bio->bi_phys_segments == 0)
1101 bio->bi_phys_segments = 2;
1102 else
1103 bio->bi_phys_segments++;
1104 spin_unlock_irq(&conf->device_lock);
1105 }
1106 sectors_handled = r10_bio->sector + max_sectors - bio->bi_sector;
1107
1108 atomic_set(&r10_bio->remaining, 1);
1109 bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
1110
1111 for (i = 0; i < conf->copies; i++) {
1112 struct bio *mbio;
1113 int d = r10_bio->devs[i].devnum;
1114 if (!r10_bio->devs[i].bio)
1115 continue;
1116
1117 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1118 md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
1119 max_sectors);
1120 r10_bio->devs[i].bio = mbio;
1121
1122 mbio->bi_sector = (r10_bio->devs[i].addr+
1123 conf->mirrors[d].rdev->data_offset);
1124 mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
1125 mbio->bi_end_io = raid10_end_write_request;
1126 mbio->bi_rw = WRITE | do_sync | do_fua;
1127 mbio->bi_private = r10_bio;
1128
1129 atomic_inc(&r10_bio->remaining);
1130 spin_lock_irqsave(&conf->device_lock, flags);
1131 bio_list_add(&conf->pending_bio_list, mbio);
1132 spin_unlock_irqrestore(&conf->device_lock, flags);
1133 }
1134
1135 /* Don't remove the bias on 'remaining' (one_write_done) until
1136 * after checking if we need to go around again.
1137 */
1138
1139 if (sectors_handled < (bio->bi_size >> 9)) {
1140 one_write_done(r10_bio);
1141 /* We need another r10_bio. It has already been counted
1142 * in bio->bi_phys_segments.
1143 */
1144 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1145
1146 r10_bio->master_bio = bio;
1147 r10_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
1148
1149 r10_bio->mddev = mddev;
1150 r10_bio->sector = bio->bi_sector + sectors_handled;
1151 r10_bio->state = 0;
1152 goto retry_write;
1153 }
1154 one_write_done(r10_bio);
1155
1156 /* In case raid10d snuck in to freeze_array */
1157 wake_up(&conf->wait_barrier);
1158
1159 if (do_sync || !mddev->bitmap || !plugged)
1160 md_wakeup_thread(mddev->thread);
1161 return 0;
1162}
1163
1164static void status(struct seq_file *seq, mddev_t *mddev)
1165{
1166 conf_t *conf = mddev->private;
1167 int i;
1168
1169 if (conf->near_copies < conf->raid_disks)
1170 seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
1171 if (conf->near_copies > 1)
1172 seq_printf(seq, " %d near-copies", conf->near_copies);
1173 if (conf->far_copies > 1) {
1174 if (conf->far_offset)
1175 seq_printf(seq, " %d offset-copies", conf->far_copies);
1176 else
1177 seq_printf(seq, " %d far-copies", conf->far_copies);
1178 }
1179 seq_printf(seq, " [%d/%d] [", conf->raid_disks,
1180 conf->raid_disks - mddev->degraded);
1181 for (i = 0; i < conf->raid_disks; i++)
1182 seq_printf(seq, "%s",
1183 conf->mirrors[i].rdev &&
1184 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
1185 seq_printf(seq, "]");
1186}
1187
1188/* check if there are enough drives for
1189 * every block to appear on atleast one.
1190 * Don't consider the device numbered 'ignore'
1191 * as we might be about to remove it.
1192 */
1193static int enough(conf_t *conf, int ignore)
1194{
1195 int first = 0;
1196
1197 do {
1198 int n = conf->copies;
1199 int cnt = 0;
1200 while (n--) {
1201 if (conf->mirrors[first].rdev &&
1202 first != ignore)
1203 cnt++;
1204 first = (first+1) % conf->raid_disks;
1205 }
1206 if (cnt == 0)
1207 return 0;
1208 } while (first != 0);
1209 return 1;
1210}
1211
1212static void error(mddev_t *mddev, mdk_rdev_t *rdev)
1213{
1214 char b[BDEVNAME_SIZE];
1215 conf_t *conf = mddev->private;
1216
1217 /*
1218 * If it is not operational, then we have already marked it as dead
1219 * else if it is the last working disks, ignore the error, let the
1220 * next level up know.
1221 * else mark the drive as failed
1222 */
1223 if (test_bit(In_sync, &rdev->flags)
1224 && !enough(conf, rdev->raid_disk))
1225 /*
1226 * Don't fail the drive, just return an IO error.
1227 */
1228 return;
1229 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1230 unsigned long flags;
1231 spin_lock_irqsave(&conf->device_lock, flags);
1232 mddev->degraded++;
1233 spin_unlock_irqrestore(&conf->device_lock, flags);
1234 /*
1235 * if recovery is running, make sure it aborts.
1236 */
1237 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1238 }
1239 set_bit(Blocked, &rdev->flags);
1240 set_bit(Faulty, &rdev->flags);
1241 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1242 printk(KERN_ALERT
1243 "md/raid10:%s: Disk failure on %s, disabling device.\n"
1244 "md/raid10:%s: Operation continuing on %d devices.\n",
1245 mdname(mddev), bdevname(rdev->bdev, b),
1246 mdname(mddev), conf->raid_disks - mddev->degraded);
1247}
1248
1249static void print_conf(conf_t *conf)
1250{
1251 int i;
1252 mirror_info_t *tmp;
1253
1254 printk(KERN_DEBUG "RAID10 conf printout:\n");
1255 if (!conf) {
1256 printk(KERN_DEBUG "(!conf)\n");
1257 return;
1258 }
1259 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
1260 conf->raid_disks);
1261
1262 for (i = 0; i < conf->raid_disks; i++) {
1263 char b[BDEVNAME_SIZE];
1264 tmp = conf->mirrors + i;
1265 if (tmp->rdev)
1266 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
1267 i, !test_bit(In_sync, &tmp->rdev->flags),
1268 !test_bit(Faulty, &tmp->rdev->flags),
1269 bdevname(tmp->rdev->bdev,b));
1270 }
1271}
1272
1273static void close_sync(conf_t *conf)
1274{
1275 wait_barrier(conf);
1276 allow_barrier(conf);
1277
1278 mempool_destroy(conf->r10buf_pool);
1279 conf->r10buf_pool = NULL;
1280}
1281
1282static int raid10_spare_active(mddev_t *mddev)
1283{
1284 int i;
1285 conf_t *conf = mddev->private;
1286 mirror_info_t *tmp;
1287 int count = 0;
1288 unsigned long flags;
1289
1290 /*
1291 * Find all non-in_sync disks within the RAID10 configuration
1292 * and mark them in_sync
1293 */
1294 for (i = 0; i < conf->raid_disks; i++) {
1295 tmp = conf->mirrors + i;
1296 if (tmp->rdev
1297 && !test_bit(Faulty, &tmp->rdev->flags)
1298 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
1299 count++;
1300 sysfs_notify_dirent(tmp->rdev->sysfs_state);
1301 }
1302 }
1303 spin_lock_irqsave(&conf->device_lock, flags);
1304 mddev->degraded -= count;
1305 spin_unlock_irqrestore(&conf->device_lock, flags);
1306
1307 print_conf(conf);
1308 return count;
1309}
1310
1311
1312static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
1313{
1314 conf_t *conf = mddev->private;
1315 int err = -EEXIST;
1316 int mirror;
1317 int first = 0;
1318 int last = conf->raid_disks - 1;
1319
1320 if (mddev->recovery_cp < MaxSector)
1321 /* only hot-add to in-sync arrays, as recovery is
1322 * very different from resync
1323 */
1324 return -EBUSY;
1325 if (!enough(conf, -1))
1326 return -EINVAL;
1327
1328 if (rdev->raid_disk >= 0)
1329 first = last = rdev->raid_disk;
1330
1331 if (rdev->saved_raid_disk >= first &&
1332 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1333 mirror = rdev->saved_raid_disk;
1334 else
1335 mirror = first;
1336 for ( ; mirror <= last ; mirror++) {
1337 mirror_info_t *p = &conf->mirrors[mirror];
1338 if (p->recovery_disabled == mddev->recovery_disabled)
1339 continue;
1340 if (!p->rdev)
1341 continue;
1342
1343 disk_stack_limits(mddev->gendisk, rdev->bdev,
1344 rdev->data_offset << 9);
1345 /* as we don't honour merge_bvec_fn, we must
1346 * never risk violating it, so limit
1347 * ->max_segments to one lying with a single
1348 * page, as a one page request is never in
1349 * violation.
1350 */
1351 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
1352 blk_queue_max_segments(mddev->queue, 1);
1353 blk_queue_segment_boundary(mddev->queue,
1354 PAGE_CACHE_SIZE - 1);
1355 }
1356
1357 p->head_position = 0;
1358 rdev->raid_disk = mirror;
1359 err = 0;
1360 if (rdev->saved_raid_disk != mirror)
1361 conf->fullsync = 1;
1362 rcu_assign_pointer(p->rdev, rdev);
1363 break;
1364 }
1365
1366 md_integrity_add_rdev(rdev, mddev);
1367 print_conf(conf);
1368 return err;
1369}
1370
1371static int raid10_remove_disk(mddev_t *mddev, int number)
1372{
1373 conf_t *conf = mddev->private;
1374 int err = 0;
1375 mdk_rdev_t *rdev;
1376 mirror_info_t *p = conf->mirrors+ number;
1377
1378 print_conf(conf);
1379 rdev = p->rdev;
1380 if (rdev) {
1381 if (test_bit(In_sync, &rdev->flags) ||
1382 atomic_read(&rdev->nr_pending)) {
1383 err = -EBUSY;
1384 goto abort;
1385 }
1386 /* Only remove faulty devices in recovery
1387 * is not possible.
1388 */
1389 if (!test_bit(Faulty, &rdev->flags) &&
1390 mddev->recovery_disabled != p->recovery_disabled &&
1391 enough(conf, -1)) {
1392 err = -EBUSY;
1393 goto abort;
1394 }
1395 p->rdev = NULL;
1396 synchronize_rcu();
1397 if (atomic_read(&rdev->nr_pending)) {
1398 /* lost the race, try later */
1399 err = -EBUSY;
1400 p->rdev = rdev;
1401 goto abort;
1402 }
1403 err = md_integrity_register(mddev);
1404 }
1405abort:
1406
1407 print_conf(conf);
1408 return err;
1409}
1410
1411
1412static void end_sync_read(struct bio *bio, int error)
1413{
1414 r10bio_t *r10_bio = bio->bi_private;
1415 conf_t *conf = r10_bio->mddev->private;
1416 int d;
1417
1418 d = find_bio_disk(conf, r10_bio, bio, NULL);
1419
1420 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1421 set_bit(R10BIO_Uptodate, &r10_bio->state);
1422 else
1423 /* The write handler will notice the lack of
1424 * R10BIO_Uptodate and record any errors etc
1425 */
1426 atomic_add(r10_bio->sectors,
1427 &conf->mirrors[d].rdev->corrected_errors);
1428
1429 /* for reconstruct, we always reschedule after a read.
1430 * for resync, only after all reads
1431 */
1432 rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
1433 if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
1434 atomic_dec_and_test(&r10_bio->remaining)) {
1435 /* we have read all the blocks,
1436 * do the comparison in process context in raid10d
1437 */
1438 reschedule_retry(r10_bio);
1439 }
1440}
1441
1442static void end_sync_request(r10bio_t *r10_bio)
1443{
1444 mddev_t *mddev = r10_bio->mddev;
1445
1446 while (atomic_dec_and_test(&r10_bio->remaining)) {
1447 if (r10_bio->master_bio == NULL) {
1448 /* the primary of several recovery bios */
1449 sector_t s = r10_bio->sectors;
1450 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
1451 test_bit(R10BIO_WriteError, &r10_bio->state))
1452 reschedule_retry(r10_bio);
1453 else
1454 put_buf(r10_bio);
1455 md_done_sync(mddev, s, 1);
1456 break;
1457 } else {
1458 r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio;
1459 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
1460 test_bit(R10BIO_WriteError, &r10_bio->state))
1461 reschedule_retry(r10_bio);
1462 else
1463 put_buf(r10_bio);
1464 r10_bio = r10_bio2;
1465 }
1466 }
1467}
1468
1469static void end_sync_write(struct bio *bio, int error)
1470{
1471 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
1472 r10bio_t *r10_bio = bio->bi_private;
1473 mddev_t *mddev = r10_bio->mddev;
1474 conf_t *conf = mddev->private;
1475 int d;
1476 sector_t first_bad;
1477 int bad_sectors;
1478 int slot;
1479
1480 d = find_bio_disk(conf, r10_bio, bio, &slot);
1481
1482 if (!uptodate) {
1483 set_bit(WriteErrorSeen, &conf->mirrors[d].rdev->flags);
1484 set_bit(R10BIO_WriteError, &r10_bio->state);
1485 } else if (is_badblock(conf->mirrors[d].rdev,
1486 r10_bio->devs[slot].addr,
1487 r10_bio->sectors,
1488 &first_bad, &bad_sectors))
1489 set_bit(R10BIO_MadeGood, &r10_bio->state);
1490
1491 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
1492
1493 end_sync_request(r10_bio);
1494}
1495
1496/*
1497 * Note: sync and recover and handled very differently for raid10
1498 * This code is for resync.
1499 * For resync, we read through virtual addresses and read all blocks.
1500 * If there is any error, we schedule a write. The lowest numbered
1501 * drive is authoritative.
1502 * However requests come for physical address, so we need to map.
1503 * For every physical address there are raid_disks/copies virtual addresses,
1504 * which is always are least one, but is not necessarly an integer.
1505 * This means that a physical address can span multiple chunks, so we may
1506 * have to submit multiple io requests for a single sync request.
1507 */
1508/*
1509 * We check if all blocks are in-sync and only write to blocks that
1510 * aren't in sync
1511 */
1512static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio)
1513{
1514 conf_t *conf = mddev->private;
1515 int i, first;
1516 struct bio *tbio, *fbio;
1517
1518 atomic_set(&r10_bio->remaining, 1);
1519
1520 /* find the first device with a block */
1521 for (i=0; i<conf->copies; i++)
1522 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags))
1523 break;
1524
1525 if (i == conf->copies)
1526 goto done;
1527
1528 first = i;
1529 fbio = r10_bio->devs[i].bio;
1530
1531 /* now find blocks with errors */
1532 for (i=0 ; i < conf->copies ; i++) {
1533 int j, d;
1534 int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9);
1535
1536 tbio = r10_bio->devs[i].bio;
1537
1538 if (tbio->bi_end_io != end_sync_read)
1539 continue;
1540 if (i == first)
1541 continue;
1542 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) {
1543 /* We know that the bi_io_vec layout is the same for
1544 * both 'first' and 'i', so we just compare them.
1545 * All vec entries are PAGE_SIZE;
1546 */
1547 for (j = 0; j < vcnt; j++)
1548 if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
1549 page_address(tbio->bi_io_vec[j].bv_page),
1550 PAGE_SIZE))
1551 break;
1552 if (j == vcnt)
1553 continue;
1554 mddev->resync_mismatches += r10_bio->sectors;
1555 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
1556 /* Don't fix anything. */
1557 continue;
1558 }
1559 /* Ok, we need to write this bio, either to correct an
1560 * inconsistency or to correct an unreadable block.
1561 * First we need to fixup bv_offset, bv_len and
1562 * bi_vecs, as the read request might have corrupted these
1563 */
1564 tbio->bi_vcnt = vcnt;
1565 tbio->bi_size = r10_bio->sectors << 9;
1566 tbio->bi_idx = 0;
1567 tbio->bi_phys_segments = 0;
1568 tbio->bi_flags &= ~(BIO_POOL_MASK - 1);
1569 tbio->bi_flags |= 1 << BIO_UPTODATE;
1570 tbio->bi_next = NULL;
1571 tbio->bi_rw = WRITE;
1572 tbio->bi_private = r10_bio;
1573 tbio->bi_sector = r10_bio->devs[i].addr;
1574
1575 for (j=0; j < vcnt ; j++) {
1576 tbio->bi_io_vec[j].bv_offset = 0;
1577 tbio->bi_io_vec[j].bv_len = PAGE_SIZE;
1578
1579 memcpy(page_address(tbio->bi_io_vec[j].bv_page),
1580 page_address(fbio->bi_io_vec[j].bv_page),
1581 PAGE_SIZE);
1582 }
1583 tbio->bi_end_io = end_sync_write;
1584
1585 d = r10_bio->devs[i].devnum;
1586 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1587 atomic_inc(&r10_bio->remaining);
1588 md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9);
1589
1590 tbio->bi_sector += conf->mirrors[d].rdev->data_offset;
1591 tbio->bi_bdev = conf->mirrors[d].rdev->bdev;
1592 generic_make_request(tbio);
1593 }
1594
1595done:
1596 if (atomic_dec_and_test(&r10_bio->remaining)) {
1597 md_done_sync(mddev, r10_bio->sectors, 1);
1598 put_buf(r10_bio);
1599 }
1600}
1601
1602/*
1603 * Now for the recovery code.
1604 * Recovery happens across physical sectors.
1605 * We recover all non-is_sync drives by finding the virtual address of
1606 * each, and then choose a working drive that also has that virt address.
1607 * There is a separate r10_bio for each non-in_sync drive.
1608 * Only the first two slots are in use. The first for reading,
1609 * The second for writing.
1610 *
1611 */
1612static void fix_recovery_read_error(r10bio_t *r10_bio)
1613{
1614 /* We got a read error during recovery.
1615 * We repeat the read in smaller page-sized sections.
1616 * If a read succeeds, write it to the new device or record
1617 * a bad block if we cannot.
1618 * If a read fails, record a bad block on both old and
1619 * new devices.
1620 */
1621 mddev_t *mddev = r10_bio->mddev;
1622 conf_t *conf = mddev->private;
1623 struct bio *bio = r10_bio->devs[0].bio;
1624 sector_t sect = 0;
1625 int sectors = r10_bio->sectors;
1626 int idx = 0;
1627 int dr = r10_bio->devs[0].devnum;
1628 int dw = r10_bio->devs[1].devnum;
1629
1630 while (sectors) {
1631 int s = sectors;
1632 mdk_rdev_t *rdev;
1633 sector_t addr;
1634 int ok;
1635
1636 if (s > (PAGE_SIZE>>9))
1637 s = PAGE_SIZE >> 9;
1638
1639 rdev = conf->mirrors[dr].rdev;
1640 addr = r10_bio->devs[0].addr + sect,
1641 ok = sync_page_io(rdev,
1642 addr,
1643 s << 9,
1644 bio->bi_io_vec[idx].bv_page,
1645 READ, false);
1646 if (ok) {
1647 rdev = conf->mirrors[dw].rdev;
1648 addr = r10_bio->devs[1].addr + sect;
1649 ok = sync_page_io(rdev,
1650 addr,
1651 s << 9,
1652 bio->bi_io_vec[idx].bv_page,
1653 WRITE, false);
1654 if (!ok)
1655 set_bit(WriteErrorSeen, &rdev->flags);
1656 }
1657 if (!ok) {
1658 /* We don't worry if we cannot set a bad block -
1659 * it really is bad so there is no loss in not
1660 * recording it yet
1661 */
1662 rdev_set_badblocks(rdev, addr, s, 0);
1663
1664 if (rdev != conf->mirrors[dw].rdev) {
1665 /* need bad block on destination too */
1666 mdk_rdev_t *rdev2 = conf->mirrors[dw].rdev;
1667 addr = r10_bio->devs[1].addr + sect;
1668 ok = rdev_set_badblocks(rdev2, addr, s, 0);
1669 if (!ok) {
1670 /* just abort the recovery */
1671 printk(KERN_NOTICE
1672 "md/raid10:%s: recovery aborted"
1673 " due to read error\n",
1674 mdname(mddev));
1675
1676 conf->mirrors[dw].recovery_disabled
1677 = mddev->recovery_disabled;
1678 set_bit(MD_RECOVERY_INTR,
1679 &mddev->recovery);
1680 break;
1681 }
1682 }
1683 }
1684
1685 sectors -= s;
1686 sect += s;
1687 idx++;
1688 }
1689}
1690
1691static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
1692{
1693 conf_t *conf = mddev->private;
1694 int d;
1695 struct bio *wbio;
1696
1697 if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
1698 fix_recovery_read_error(r10_bio);
1699 end_sync_request(r10_bio);
1700 return;
1701 }
1702
1703 /*
1704 * share the pages with the first bio
1705 * and submit the write request
1706 */
1707 wbio = r10_bio->devs[1].bio;
1708 d = r10_bio->devs[1].devnum;
1709
1710 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
1711 md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
1712 generic_make_request(wbio);
1713}
1714
1715
1716/*
1717 * Used by fix_read_error() to decay the per rdev read_errors.
1718 * We halve the read error count for every hour that has elapsed
1719 * since the last recorded read error.
1720 *
1721 */
1722static void check_decay_read_errors(mddev_t *mddev, mdk_rdev_t *rdev)
1723{
1724 struct timespec cur_time_mon;
1725 unsigned long hours_since_last;
1726 unsigned int read_errors = atomic_read(&rdev->read_errors);
1727
1728 ktime_get_ts(&cur_time_mon);
1729
1730 if (rdev->last_read_error.tv_sec == 0 &&
1731 rdev->last_read_error.tv_nsec == 0) {
1732 /* first time we've seen a read error */
1733 rdev->last_read_error = cur_time_mon;
1734 return;
1735 }
1736
1737 hours_since_last = (cur_time_mon.tv_sec -
1738 rdev->last_read_error.tv_sec) / 3600;
1739
1740 rdev->last_read_error = cur_time_mon;
1741
1742 /*
1743 * if hours_since_last is > the number of bits in read_errors
1744 * just set read errors to 0. We do this to avoid
1745 * overflowing the shift of read_errors by hours_since_last.
1746 */
1747 if (hours_since_last >= 8 * sizeof(read_errors))
1748 atomic_set(&rdev->read_errors, 0);
1749 else
1750 atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
1751}
1752
1753static int r10_sync_page_io(mdk_rdev_t *rdev, sector_t sector,
1754 int sectors, struct page *page, int rw)
1755{
1756 sector_t first_bad;
1757 int bad_sectors;
1758
1759 if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors)
1760 && (rw == READ || test_bit(WriteErrorSeen, &rdev->flags)))
1761 return -1;
1762 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
1763 /* success */
1764 return 1;
1765 if (rw == WRITE)
1766 set_bit(WriteErrorSeen, &rdev->flags);
1767 /* need to record an error - either for the block or the device */
1768 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
1769 md_error(rdev->mddev, rdev);
1770 return 0;
1771}
1772
1773/*
1774 * This is a kernel thread which:
1775 *
1776 * 1. Retries failed read operations on working mirrors.
1777 * 2. Updates the raid superblock when problems encounter.
1778 * 3. Performs writes following reads for array synchronising.
1779 */
1780
1781static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
1782{
1783 int sect = 0; /* Offset from r10_bio->sector */
1784 int sectors = r10_bio->sectors;
1785 mdk_rdev_t*rdev;
1786 int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
1787 int d = r10_bio->devs[r10_bio->read_slot].devnum;
1788
1789 /* still own a reference to this rdev, so it cannot
1790 * have been cleared recently.
1791 */
1792 rdev = conf->mirrors[d].rdev;
1793
1794 if (test_bit(Faulty, &rdev->flags))
1795 /* drive has already been failed, just ignore any
1796 more fix_read_error() attempts */
1797 return;
1798
1799 check_decay_read_errors(mddev, rdev);
1800 atomic_inc(&rdev->read_errors);
1801 if (atomic_read(&rdev->read_errors) > max_read_errors) {
1802 char b[BDEVNAME_SIZE];
1803 bdevname(rdev->bdev, b);
1804
1805 printk(KERN_NOTICE
1806 "md/raid10:%s: %s: Raid device exceeded "
1807 "read_error threshold [cur %d:max %d]\n",
1808 mdname(mddev), b,
1809 atomic_read(&rdev->read_errors), max_read_errors);
1810 printk(KERN_NOTICE
1811 "md/raid10:%s: %s: Failing raid device\n",
1812 mdname(mddev), b);
1813 md_error(mddev, conf->mirrors[d].rdev);
1814 return;
1815 }
1816
1817 while(sectors) {
1818 int s = sectors;
1819 int sl = r10_bio->read_slot;
1820 int success = 0;
1821 int start;
1822
1823 if (s > (PAGE_SIZE>>9))
1824 s = PAGE_SIZE >> 9;
1825
1826 rcu_read_lock();
1827 do {
1828 sector_t first_bad;
1829 int bad_sectors;
1830
1831 d = r10_bio->devs[sl].devnum;
1832 rdev = rcu_dereference(conf->mirrors[d].rdev);
1833 if (rdev &&
1834 test_bit(In_sync, &rdev->flags) &&
1835 is_badblock(rdev, r10_bio->devs[sl].addr + sect, s,
1836 &first_bad, &bad_sectors) == 0) {
1837 atomic_inc(&rdev->nr_pending);
1838 rcu_read_unlock();
1839 success = sync_page_io(rdev,
1840 r10_bio->devs[sl].addr +
1841 sect,
1842 s<<9,
1843 conf->tmppage, READ, false);
1844 rdev_dec_pending(rdev, mddev);
1845 rcu_read_lock();
1846 if (success)
1847 break;
1848 }
1849 sl++;
1850 if (sl == conf->copies)
1851 sl = 0;
1852 } while (!success && sl != r10_bio->read_slot);
1853 rcu_read_unlock();
1854
1855 if (!success) {
1856 /* Cannot read from anywhere, just mark the block
1857 * as bad on the first device to discourage future
1858 * reads.
1859 */
1860 int dn = r10_bio->devs[r10_bio->read_slot].devnum;
1861 rdev = conf->mirrors[dn].rdev;
1862
1863 if (!rdev_set_badblocks(
1864 rdev,
1865 r10_bio->devs[r10_bio->read_slot].addr
1866 + sect,
1867 s, 0))
1868 md_error(mddev, rdev);
1869 break;
1870 }
1871
1872 start = sl;
1873 /* write it back and re-read */
1874 rcu_read_lock();
1875 while (sl != r10_bio->read_slot) {
1876 char b[BDEVNAME_SIZE];
1877
1878 if (sl==0)
1879 sl = conf->copies;
1880 sl--;
1881 d = r10_bio->devs[sl].devnum;
1882 rdev = rcu_dereference(conf->mirrors[d].rdev);
1883 if (!rdev ||
1884 !test_bit(In_sync, &rdev->flags))
1885 continue;
1886
1887 atomic_inc(&rdev->nr_pending);
1888 rcu_read_unlock();
1889 if (r10_sync_page_io(rdev,
1890 r10_bio->devs[sl].addr +
1891 sect,
1892 s<<9, conf->tmppage, WRITE)
1893 == 0) {
1894 /* Well, this device is dead */
1895 printk(KERN_NOTICE
1896 "md/raid10:%s: read correction "
1897 "write failed"
1898 " (%d sectors at %llu on %s)\n",
1899 mdname(mddev), s,
1900 (unsigned long long)(
1901 sect + rdev->data_offset),
1902 bdevname(rdev->bdev, b));
1903 printk(KERN_NOTICE "md/raid10:%s: %s: failing "
1904 "drive\n",
1905 mdname(mddev),
1906 bdevname(rdev->bdev, b));
1907 }
1908 rdev_dec_pending(rdev, mddev);
1909 rcu_read_lock();
1910 }
1911 sl = start;
1912 while (sl != r10_bio->read_slot) {
1913 char b[BDEVNAME_SIZE];
1914
1915 if (sl==0)
1916 sl = conf->copies;
1917 sl--;
1918 d = r10_bio->devs[sl].devnum;
1919 rdev = rcu_dereference(conf->mirrors[d].rdev);
1920 if (!rdev ||
1921 !test_bit(In_sync, &rdev->flags))
1922 continue;
1923
1924 atomic_inc(&rdev->nr_pending);
1925 rcu_read_unlock();
1926 switch (r10_sync_page_io(rdev,
1927 r10_bio->devs[sl].addr +
1928 sect,
1929 s<<9, conf->tmppage,
1930 READ)) {
1931 case 0:
1932 /* Well, this device is dead */
1933 printk(KERN_NOTICE
1934 "md/raid10:%s: unable to read back "
1935 "corrected sectors"
1936 " (%d sectors at %llu on %s)\n",
1937 mdname(mddev), s,
1938 (unsigned long long)(
1939 sect + rdev->data_offset),
1940 bdevname(rdev->bdev, b));
1941 printk(KERN_NOTICE "md/raid10:%s: %s: failing "
1942 "drive\n",
1943 mdname(mddev),
1944 bdevname(rdev->bdev, b));
1945 break;
1946 case 1:
1947 printk(KERN_INFO
1948 "md/raid10:%s: read error corrected"
1949 " (%d sectors at %llu on %s)\n",
1950 mdname(mddev), s,
1951 (unsigned long long)(
1952 sect + rdev->data_offset),
1953 bdevname(rdev->bdev, b));
1954 atomic_add(s, &rdev->corrected_errors);
1955 }
1956
1957 rdev_dec_pending(rdev, mddev);
1958 rcu_read_lock();
1959 }
1960 rcu_read_unlock();
1961
1962 sectors -= s;
1963 sect += s;
1964 }
1965}
1966
1967static void bi_complete(struct bio *bio, int error)
1968{
1969 complete((struct completion *)bio->bi_private);
1970}
1971
1972static int submit_bio_wait(int rw, struct bio *bio)
1973{
1974 struct completion event;
1975 rw |= REQ_SYNC;
1976
1977 init_completion(&event);
1978 bio->bi_private = &event;
1979 bio->bi_end_io = bi_complete;
1980 submit_bio(rw, bio);
1981 wait_for_completion(&event);
1982
1983 return test_bit(BIO_UPTODATE, &bio->bi_flags);
1984}
1985
1986static int narrow_write_error(r10bio_t *r10_bio, int i)
1987{
1988 struct bio *bio = r10_bio->master_bio;
1989 mddev_t *mddev = r10_bio->mddev;
1990 conf_t *conf = mddev->private;
1991 mdk_rdev_t *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev;
1992 /* bio has the data to be written to slot 'i' where
1993 * we just recently had a write error.
1994 * We repeatedly clone the bio and trim down to one block,
1995 * then try the write. Where the write fails we record
1996 * a bad block.
1997 * It is conceivable that the bio doesn't exactly align with
1998 * blocks. We must handle this.
1999 *
2000 * We currently own a reference to the rdev.
2001 */
2002
2003 int block_sectors;
2004 sector_t sector;
2005 int sectors;
2006 int sect_to_write = r10_bio->sectors;
2007 int ok = 1;
2008
2009 if (rdev->badblocks.shift < 0)
2010 return 0;
2011
2012 block_sectors = 1 << rdev->badblocks.shift;
2013 sector = r10_bio->sector;
2014 sectors = ((r10_bio->sector + block_sectors)
2015 & ~(sector_t)(block_sectors - 1))
2016 - sector;
2017
2018 while (sect_to_write) {
2019 struct bio *wbio;
2020 if (sectors > sect_to_write)
2021 sectors = sect_to_write;
2022 /* Write at 'sector' for 'sectors' */
2023 wbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
2024 md_trim_bio(wbio, sector - bio->bi_sector, sectors);
2025 wbio->bi_sector = (r10_bio->devs[i].addr+
2026 rdev->data_offset+
2027 (sector - r10_bio->sector));
2028 wbio->bi_bdev = rdev->bdev;
2029 if (submit_bio_wait(WRITE, wbio) == 0)
2030 /* Failure! */
2031 ok = rdev_set_badblocks(rdev, sector,
2032 sectors, 0)
2033 && ok;
2034
2035 bio_put(wbio);
2036 sect_to_write -= sectors;
2037 sector += sectors;
2038 sectors = block_sectors;
2039 }
2040 return ok;
2041}
2042
2043static void handle_read_error(mddev_t *mddev, r10bio_t *r10_bio)
2044{
2045 int slot = r10_bio->read_slot;
2046 int mirror = r10_bio->devs[slot].devnum;
2047 struct bio *bio;
2048 conf_t *conf = mddev->private;
2049 mdk_rdev_t *rdev;
2050 char b[BDEVNAME_SIZE];
2051 unsigned long do_sync;
2052 int max_sectors;
2053
2054 /* we got a read error. Maybe the drive is bad. Maybe just
2055 * the block and we can fix it.
2056 * We freeze all other IO, and try reading the block from
2057 * other devices. When we find one, we re-write
2058 * and check it that fixes the read error.
2059 * This is all done synchronously while the array is
2060 * frozen.
2061 */
2062 if (mddev->ro == 0) {
2063 freeze_array(conf);
2064 fix_read_error(conf, mddev, r10_bio);
2065 unfreeze_array(conf);
2066 }
2067 rdev_dec_pending(conf->mirrors[mirror].rdev, mddev);
2068
2069 bio = r10_bio->devs[slot].bio;
2070 bdevname(bio->bi_bdev, b);
2071 r10_bio->devs[slot].bio =
2072 mddev->ro ? IO_BLOCKED : NULL;
2073read_more:
2074 mirror = read_balance(conf, r10_bio, &max_sectors);
2075 if (mirror == -1) {
2076 printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O"
2077 " read error for block %llu\n",
2078 mdname(mddev), b,
2079 (unsigned long long)r10_bio->sector);
2080 raid_end_bio_io(r10_bio);
2081 bio_put(bio);
2082 return;
2083 }
2084
2085 do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC);
2086 if (bio)
2087 bio_put(bio);
2088 slot = r10_bio->read_slot;
2089 rdev = conf->mirrors[mirror].rdev;
2090 printk_ratelimited(
2091 KERN_ERR
2092 "md/raid10:%s: %s: redirecting"
2093 "sector %llu to another mirror\n",
2094 mdname(mddev),
2095 bdevname(rdev->bdev, b),
2096 (unsigned long long)r10_bio->sector);
2097 bio = bio_clone_mddev(r10_bio->master_bio,
2098 GFP_NOIO, mddev);
2099 md_trim_bio(bio,
2100 r10_bio->sector - bio->bi_sector,
2101 max_sectors);
2102 r10_bio->devs[slot].bio = bio;
2103 bio->bi_sector = r10_bio->devs[slot].addr
2104 + rdev->data_offset;
2105 bio->bi_bdev = rdev->bdev;
2106 bio->bi_rw = READ | do_sync;
2107 bio->bi_private = r10_bio;
2108 bio->bi_end_io = raid10_end_read_request;
2109 if (max_sectors < r10_bio->sectors) {
2110 /* Drat - have to split this up more */
2111 struct bio *mbio = r10_bio->master_bio;
2112 int sectors_handled =
2113 r10_bio->sector + max_sectors
2114 - mbio->bi_sector;
2115 r10_bio->sectors = max_sectors;
2116 spin_lock_irq(&conf->device_lock);
2117 if (mbio->bi_phys_segments == 0)
2118 mbio->bi_phys_segments = 2;
2119 else
2120 mbio->bi_phys_segments++;
2121 spin_unlock_irq(&conf->device_lock);
2122 generic_make_request(bio);
2123 bio = NULL;
2124
2125 r10_bio = mempool_alloc(conf->r10bio_pool,
2126 GFP_NOIO);
2127 r10_bio->master_bio = mbio;
2128 r10_bio->sectors = (mbio->bi_size >> 9)
2129 - sectors_handled;
2130 r10_bio->state = 0;
2131 set_bit(R10BIO_ReadError,
2132 &r10_bio->state);
2133 r10_bio->mddev = mddev;
2134 r10_bio->sector = mbio->bi_sector
2135 + sectors_handled;
2136
2137 goto read_more;
2138 } else
2139 generic_make_request(bio);
2140}
2141
2142static void handle_write_completed(conf_t *conf, r10bio_t *r10_bio)
2143{
2144 /* Some sort of write request has finished and it
2145 * succeeded in writing where we thought there was a
2146 * bad block. So forget the bad block.
2147 * Or possibly if failed and we need to record
2148 * a bad block.
2149 */
2150 int m;
2151 mdk_rdev_t *rdev;
2152
2153 if (test_bit(R10BIO_IsSync, &r10_bio->state) ||
2154 test_bit(R10BIO_IsRecover, &r10_bio->state)) {
2155 for (m = 0; m < conf->copies; m++) {
2156 int dev = r10_bio->devs[m].devnum;
2157 rdev = conf->mirrors[dev].rdev;
2158 if (r10_bio->devs[m].bio == NULL)
2159 continue;
2160 if (test_bit(BIO_UPTODATE,
2161 &r10_bio->devs[m].bio->bi_flags)) {
2162 rdev_clear_badblocks(
2163 rdev,
2164 r10_bio->devs[m].addr,
2165 r10_bio->sectors);
2166 } else {
2167 if (!rdev_set_badblocks(
2168 rdev,
2169 r10_bio->devs[m].addr,
2170 r10_bio->sectors, 0))
2171 md_error(conf->mddev, rdev);
2172 }
2173 }
2174 put_buf(r10_bio);
2175 } else {
2176 for (m = 0; m < conf->copies; m++) {
2177 int dev = r10_bio->devs[m].devnum;
2178 struct bio *bio = r10_bio->devs[m].bio;
2179 rdev = conf->mirrors[dev].rdev;
2180 if (bio == IO_MADE_GOOD) {
2181 rdev_clear_badblocks(
2182 rdev,
2183 r10_bio->devs[m].addr,
2184 r10_bio->sectors);
2185 rdev_dec_pending(rdev, conf->mddev);
2186 } else if (bio != NULL &&
2187 !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2188 if (!narrow_write_error(r10_bio, m)) {
2189 md_error(conf->mddev, rdev);
2190 set_bit(R10BIO_Degraded,
2191 &r10_bio->state);
2192 }
2193 rdev_dec_pending(rdev, conf->mddev);
2194 }
2195 }
2196 if (test_bit(R10BIO_WriteError,
2197 &r10_bio->state))
2198 close_write(r10_bio);
2199 raid_end_bio_io(r10_bio);
2200 }
2201}
2202
2203static void raid10d(mddev_t *mddev)
2204{
2205 r10bio_t *r10_bio;
2206 unsigned long flags;
2207 conf_t *conf = mddev->private;
2208 struct list_head *head = &conf->retry_list;
2209 struct blk_plug plug;
2210
2211 md_check_recovery(mddev);
2212
2213 blk_start_plug(&plug);
2214 for (;;) {
2215
2216 flush_pending_writes(conf);
2217
2218 spin_lock_irqsave(&conf->device_lock, flags);
2219 if (list_empty(head)) {
2220 spin_unlock_irqrestore(&conf->device_lock, flags);
2221 break;
2222 }
2223 r10_bio = list_entry(head->prev, r10bio_t, retry_list);
2224 list_del(head->prev);
2225 conf->nr_queued--;
2226 spin_unlock_irqrestore(&conf->device_lock, flags);
2227
2228 mddev = r10_bio->mddev;
2229 conf = mddev->private;
2230 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
2231 test_bit(R10BIO_WriteError, &r10_bio->state))
2232 handle_write_completed(conf, r10_bio);
2233 else if (test_bit(R10BIO_IsSync, &r10_bio->state))
2234 sync_request_write(mddev, r10_bio);
2235 else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
2236 recovery_request_write(mddev, r10_bio);
2237 else if (test_bit(R10BIO_ReadError, &r10_bio->state))
2238 handle_read_error(mddev, r10_bio);
2239 else {
2240 /* just a partial read to be scheduled from a
2241 * separate context
2242 */
2243 int slot = r10_bio->read_slot;
2244 generic_make_request(r10_bio->devs[slot].bio);
2245 }
2246
2247 cond_resched();
2248 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2249 md_check_recovery(mddev);
2250 }
2251 blk_finish_plug(&plug);
2252}
2253
2254
2255static int init_resync(conf_t *conf)
2256{
2257 int buffs;
2258
2259 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2260 BUG_ON(conf->r10buf_pool);
2261 conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
2262 if (!conf->r10buf_pool)
2263 return -ENOMEM;
2264 conf->next_resync = 0;
2265 return 0;
2266}
2267
2268/*
2269 * perform a "sync" on one "block"
2270 *
2271 * We need to make sure that no normal I/O request - particularly write
2272 * requests - conflict with active sync requests.
2273 *
2274 * This is achieved by tracking pending requests and a 'barrier' concept
2275 * that can be installed to exclude normal IO requests.
2276 *
2277 * Resync and recovery are handled very differently.
2278 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
2279 *
2280 * For resync, we iterate over virtual addresses, read all copies,
2281 * and update if there are differences. If only one copy is live,
2282 * skip it.
2283 * For recovery, we iterate over physical addresses, read a good
2284 * value for each non-in_sync drive, and over-write.
2285 *
2286 * So, for recovery we may have several outstanding complex requests for a
2287 * given address, one for each out-of-sync device. We model this by allocating
2288 * a number of r10_bio structures, one for each out-of-sync device.
2289 * As we setup these structures, we collect all bio's together into a list
2290 * which we then process collectively to add pages, and then process again
2291 * to pass to generic_make_request.
2292 *
2293 * The r10_bio structures are linked using a borrowed master_bio pointer.
2294 * This link is counted in ->remaining. When the r10_bio that points to NULL
2295 * has its remaining count decremented to 0, the whole complex operation
2296 * is complete.
2297 *
2298 */
2299
2300static sector_t sync_request(mddev_t *mddev, sector_t sector_nr,
2301 int *skipped, int go_faster)
2302{
2303 conf_t *conf = mddev->private;
2304 r10bio_t *r10_bio;
2305 struct bio *biolist = NULL, *bio;
2306 sector_t max_sector, nr_sectors;
2307 int i;
2308 int max_sync;
2309 sector_t sync_blocks;
2310 sector_t sectors_skipped = 0;
2311 int chunks_skipped = 0;
2312
2313 if (!conf->r10buf_pool)
2314 if (init_resync(conf))
2315 return 0;
2316
2317 skipped:
2318 max_sector = mddev->dev_sectors;
2319 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
2320 max_sector = mddev->resync_max_sectors;
2321 if (sector_nr >= max_sector) {
2322 /* If we aborted, we need to abort the
2323 * sync on the 'current' bitmap chucks (there can
2324 * be several when recovering multiple devices).
2325 * as we may have started syncing it but not finished.
2326 * We can find the current address in
2327 * mddev->curr_resync, but for recovery,
2328 * we need to convert that to several
2329 * virtual addresses.
2330 */
2331 if (mddev->curr_resync < max_sector) { /* aborted */
2332 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
2333 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2334 &sync_blocks, 1);
2335 else for (i=0; i<conf->raid_disks; i++) {
2336 sector_t sect =
2337 raid10_find_virt(conf, mddev->curr_resync, i);
2338 bitmap_end_sync(mddev->bitmap, sect,
2339 &sync_blocks, 1);
2340 }
2341 } else /* completed sync */
2342 conf->fullsync = 0;
2343
2344 bitmap_close_sync(mddev->bitmap);
2345 close_sync(conf);
2346 *skipped = 1;
2347 return sectors_skipped;
2348 }
2349 if (chunks_skipped >= conf->raid_disks) {
2350 /* if there has been nothing to do on any drive,
2351 * then there is nothing to do at all..
2352 */
2353 *skipped = 1;
2354 return (max_sector - sector_nr) + sectors_skipped;
2355 }
2356
2357 if (max_sector > mddev->resync_max)
2358 max_sector = mddev->resync_max; /* Don't do IO beyond here */
2359
2360 /* make sure whole request will fit in a chunk - if chunks
2361 * are meaningful
2362 */
2363 if (conf->near_copies < conf->raid_disks &&
2364 max_sector > (sector_nr | conf->chunk_mask))
2365 max_sector = (sector_nr | conf->chunk_mask) + 1;
2366 /*
2367 * If there is non-resync activity waiting for us then
2368 * put in a delay to throttle resync.
2369 */
2370 if (!go_faster && conf->nr_waiting)
2371 msleep_interruptible(1000);
2372
2373 /* Again, very different code for resync and recovery.
2374 * Both must result in an r10bio with a list of bios that
2375 * have bi_end_io, bi_sector, bi_bdev set,
2376 * and bi_private set to the r10bio.
2377 * For recovery, we may actually create several r10bios
2378 * with 2 bios in each, that correspond to the bios in the main one.
2379 * In this case, the subordinate r10bios link back through a
2380 * borrowed master_bio pointer, and the counter in the master
2381 * includes a ref from each subordinate.
2382 */
2383 /* First, we decide what to do and set ->bi_end_io
2384 * To end_sync_read if we want to read, and
2385 * end_sync_write if we will want to write.
2386 */
2387
2388 max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
2389 if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
2390 /* recovery... the complicated one */
2391 int j;
2392 r10_bio = NULL;
2393
2394 for (i=0 ; i<conf->raid_disks; i++) {
2395 int still_degraded;
2396 r10bio_t *rb2;
2397 sector_t sect;
2398 int must_sync;
2399 int any_working;
2400
2401 if (conf->mirrors[i].rdev == NULL ||
2402 test_bit(In_sync, &conf->mirrors[i].rdev->flags))
2403 continue;
2404
2405 still_degraded = 0;
2406 /* want to reconstruct this device */
2407 rb2 = r10_bio;
2408 sect = raid10_find_virt(conf, sector_nr, i);
2409 /* Unless we are doing a full sync, we only need
2410 * to recover the block if it is set in the bitmap
2411 */
2412 must_sync = bitmap_start_sync(mddev->bitmap, sect,
2413 &sync_blocks, 1);
2414 if (sync_blocks < max_sync)
2415 max_sync = sync_blocks;
2416 if (!must_sync &&
2417 !conf->fullsync) {
2418 /* yep, skip the sync_blocks here, but don't assume
2419 * that there will never be anything to do here
2420 */
2421 chunks_skipped = -1;
2422 continue;
2423 }
2424
2425 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
2426 raise_barrier(conf, rb2 != NULL);
2427 atomic_set(&r10_bio->remaining, 0);
2428
2429 r10_bio->master_bio = (struct bio*)rb2;
2430 if (rb2)
2431 atomic_inc(&rb2->remaining);
2432 r10_bio->mddev = mddev;
2433 set_bit(R10BIO_IsRecover, &r10_bio->state);
2434 r10_bio->sector = sect;
2435
2436 raid10_find_phys(conf, r10_bio);
2437
2438 /* Need to check if the array will still be
2439 * degraded
2440 */
2441 for (j=0; j<conf->raid_disks; j++)
2442 if (conf->mirrors[j].rdev == NULL ||
2443 test_bit(Faulty, &conf->mirrors[j].rdev->flags)) {
2444 still_degraded = 1;
2445 break;
2446 }
2447
2448 must_sync = bitmap_start_sync(mddev->bitmap, sect,
2449 &sync_blocks, still_degraded);
2450
2451 any_working = 0;
2452 for (j=0; j<conf->copies;j++) {
2453 int k;
2454 int d = r10_bio->devs[j].devnum;
2455 sector_t from_addr, to_addr;
2456 mdk_rdev_t *rdev;
2457 sector_t sector, first_bad;
2458 int bad_sectors;
2459 if (!conf->mirrors[d].rdev ||
2460 !test_bit(In_sync, &conf->mirrors[d].rdev->flags))
2461 continue;
2462 /* This is where we read from */
2463 any_working = 1;
2464 rdev = conf->mirrors[d].rdev;
2465 sector = r10_bio->devs[j].addr;
2466
2467 if (is_badblock(rdev, sector, max_sync,
2468 &first_bad, &bad_sectors)) {
2469 if (first_bad > sector)
2470 max_sync = first_bad - sector;
2471 else {
2472 bad_sectors -= (sector
2473 - first_bad);
2474 if (max_sync > bad_sectors)
2475 max_sync = bad_sectors;
2476 continue;
2477 }
2478 }
2479 bio = r10_bio->devs[0].bio;
2480 bio->bi_next = biolist;
2481 biolist = bio;
2482 bio->bi_private = r10_bio;
2483 bio->bi_end_io = end_sync_read;
2484 bio->bi_rw = READ;
2485 from_addr = r10_bio->devs[j].addr;
2486 bio->bi_sector = from_addr +
2487 conf->mirrors[d].rdev->data_offset;
2488 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
2489 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
2490 atomic_inc(&r10_bio->remaining);
2491 /* and we write to 'i' */
2492
2493 for (k=0; k<conf->copies; k++)
2494 if (r10_bio->devs[k].devnum == i)
2495 break;
2496 BUG_ON(k == conf->copies);
2497 bio = r10_bio->devs[1].bio;
2498 bio->bi_next = biolist;
2499 biolist = bio;
2500 bio->bi_private = r10_bio;
2501 bio->bi_end_io = end_sync_write;
2502 bio->bi_rw = WRITE;
2503 to_addr = r10_bio->devs[k].addr;
2504 bio->bi_sector = to_addr +
2505 conf->mirrors[i].rdev->data_offset;
2506 bio->bi_bdev = conf->mirrors[i].rdev->bdev;
2507
2508 r10_bio->devs[0].devnum = d;
2509 r10_bio->devs[0].addr = from_addr;
2510 r10_bio->devs[1].devnum = i;
2511 r10_bio->devs[1].addr = to_addr;
2512
2513 break;
2514 }
2515 if (j == conf->copies) {
2516 /* Cannot recover, so abort the recovery or
2517 * record a bad block */
2518 put_buf(r10_bio);
2519 if (rb2)
2520 atomic_dec(&rb2->remaining);
2521 r10_bio = rb2;
2522 if (any_working) {
2523 /* problem is that there are bad blocks
2524 * on other device(s)
2525 */
2526 int k;
2527 for (k = 0; k < conf->copies; k++)
2528 if (r10_bio->devs[k].devnum == i)
2529 break;
2530 if (!rdev_set_badblocks(
2531 conf->mirrors[i].rdev,
2532 r10_bio->devs[k].addr,
2533 max_sync, 0))
2534 any_working = 0;
2535 }
2536 if (!any_working) {
2537 if (!test_and_set_bit(MD_RECOVERY_INTR,
2538 &mddev->recovery))
2539 printk(KERN_INFO "md/raid10:%s: insufficient "
2540 "working devices for recovery.\n",
2541 mdname(mddev));
2542 conf->mirrors[i].recovery_disabled
2543 = mddev->recovery_disabled;
2544 }
2545 break;
2546 }
2547 }
2548 if (biolist == NULL) {
2549 while (r10_bio) {
2550 r10bio_t *rb2 = r10_bio;
2551 r10_bio = (r10bio_t*) rb2->master_bio;
2552 rb2->master_bio = NULL;
2553 put_buf(rb2);
2554 }
2555 goto giveup;
2556 }
2557 } else {
2558 /* resync. Schedule a read for every block at this virt offset */
2559 int count = 0;
2560
2561 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
2562
2563 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
2564 &sync_blocks, mddev->degraded) &&
2565 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED,
2566 &mddev->recovery)) {
2567 /* We can skip this block */
2568 *skipped = 1;
2569 return sync_blocks + sectors_skipped;
2570 }
2571 if (sync_blocks < max_sync)
2572 max_sync = sync_blocks;
2573 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
2574
2575 r10_bio->mddev = mddev;
2576 atomic_set(&r10_bio->remaining, 0);
2577 raise_barrier(conf, 0);
2578 conf->next_resync = sector_nr;
2579
2580 r10_bio->master_bio = NULL;
2581 r10_bio->sector = sector_nr;
2582 set_bit(R10BIO_IsSync, &r10_bio->state);
2583 raid10_find_phys(conf, r10_bio);
2584 r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1;
2585
2586 for (i=0; i<conf->copies; i++) {
2587 int d = r10_bio->devs[i].devnum;
2588 sector_t first_bad, sector;
2589 int bad_sectors;
2590
2591 bio = r10_bio->devs[i].bio;
2592 bio->bi_end_io = NULL;
2593 clear_bit(BIO_UPTODATE, &bio->bi_flags);
2594 if (conf->mirrors[d].rdev == NULL ||
2595 test_bit(Faulty, &conf->mirrors[d].rdev->flags))
2596 continue;
2597 sector = r10_bio->devs[i].addr;
2598 if (is_badblock(conf->mirrors[d].rdev,
2599 sector, max_sync,
2600 &first_bad, &bad_sectors)) {
2601 if (first_bad > sector)
2602 max_sync = first_bad - sector;
2603 else {
2604 bad_sectors -= (sector - first_bad);
2605 if (max_sync > bad_sectors)
2606 max_sync = max_sync;
2607 continue;
2608 }
2609 }
2610 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
2611 atomic_inc(&r10_bio->remaining);
2612 bio->bi_next = biolist;
2613 biolist = bio;
2614 bio->bi_private = r10_bio;
2615 bio->bi_end_io = end_sync_read;
2616 bio->bi_rw = READ;
2617 bio->bi_sector = sector +
2618 conf->mirrors[d].rdev->data_offset;
2619 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
2620 count++;
2621 }
2622
2623 if (count < 2) {
2624 for (i=0; i<conf->copies; i++) {
2625 int d = r10_bio->devs[i].devnum;
2626 if (r10_bio->devs[i].bio->bi_end_io)
2627 rdev_dec_pending(conf->mirrors[d].rdev,
2628 mddev);
2629 }
2630 put_buf(r10_bio);
2631 biolist = NULL;
2632 goto giveup;
2633 }
2634 }
2635
2636 for (bio = biolist; bio ; bio=bio->bi_next) {
2637
2638 bio->bi_flags &= ~(BIO_POOL_MASK - 1);
2639 if (bio->bi_end_io)
2640 bio->bi_flags |= 1 << BIO_UPTODATE;
2641 bio->bi_vcnt = 0;
2642 bio->bi_idx = 0;
2643 bio->bi_phys_segments = 0;
2644 bio->bi_size = 0;
2645 }
2646
2647 nr_sectors = 0;
2648 if (sector_nr + max_sync < max_sector)
2649 max_sector = sector_nr + max_sync;
2650 do {
2651 struct page *page;
2652 int len = PAGE_SIZE;
2653 if (sector_nr + (len>>9) > max_sector)
2654 len = (max_sector - sector_nr) << 9;
2655 if (len == 0)
2656 break;
2657 for (bio= biolist ; bio ; bio=bio->bi_next) {
2658 struct bio *bio2;
2659 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
2660 if (bio_add_page(bio, page, len, 0))
2661 continue;
2662
2663 /* stop here */
2664 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
2665 for (bio2 = biolist;
2666 bio2 && bio2 != bio;
2667 bio2 = bio2->bi_next) {
2668 /* remove last page from this bio */
2669 bio2->bi_vcnt--;
2670 bio2->bi_size -= len;
2671 bio2->bi_flags &= ~(1<< BIO_SEG_VALID);
2672 }
2673 goto bio_full;
2674 }
2675 nr_sectors += len>>9;
2676 sector_nr += len>>9;
2677 } while (biolist->bi_vcnt < RESYNC_PAGES);
2678 bio_full:
2679 r10_bio->sectors = nr_sectors;
2680
2681 while (biolist) {
2682 bio = biolist;
2683 biolist = biolist->bi_next;
2684
2685 bio->bi_next = NULL;
2686 r10_bio = bio->bi_private;
2687 r10_bio->sectors = nr_sectors;
2688
2689 if (bio->bi_end_io == end_sync_read) {
2690 md_sync_acct(bio->bi_bdev, nr_sectors);
2691 generic_make_request(bio);
2692 }
2693 }
2694
2695 if (sectors_skipped)
2696 /* pretend they weren't skipped, it makes
2697 * no important difference in this case
2698 */
2699 md_done_sync(mddev, sectors_skipped, 1);
2700
2701 return sectors_skipped + nr_sectors;
2702 giveup:
2703 /* There is nowhere to write, so all non-sync
2704 * drives must be failed or in resync, all drives
2705 * have a bad block, so try the next chunk...
2706 */
2707 if (sector_nr + max_sync < max_sector)
2708 max_sector = sector_nr + max_sync;
2709
2710 sectors_skipped += (max_sector - sector_nr);
2711 chunks_skipped ++;
2712 sector_nr = max_sector;
2713 goto skipped;
2714}
2715
2716static sector_t
2717raid10_size(mddev_t *mddev, sector_t sectors, int raid_disks)
2718{
2719 sector_t size;
2720 conf_t *conf = mddev->private;
2721
2722 if (!raid_disks)
2723 raid_disks = conf->raid_disks;
2724 if (!sectors)
2725 sectors = conf->dev_sectors;
2726
2727 size = sectors >> conf->chunk_shift;
2728 sector_div(size, conf->far_copies);
2729 size = size * raid_disks;
2730 sector_div(size, conf->near_copies);
2731
2732 return size << conf->chunk_shift;
2733}
2734
2735
2736static conf_t *setup_conf(mddev_t *mddev)
2737{
2738 conf_t *conf = NULL;
2739 int nc, fc, fo;
2740 sector_t stride, size;
2741 int err = -EINVAL;
2742
2743 if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) ||
2744 !is_power_of_2(mddev->new_chunk_sectors)) {
2745 printk(KERN_ERR "md/raid10:%s: chunk size must be "
2746 "at least PAGE_SIZE(%ld) and be a power of 2.\n",
2747 mdname(mddev), PAGE_SIZE);
2748 goto out;
2749 }
2750
2751 nc = mddev->new_layout & 255;
2752 fc = (mddev->new_layout >> 8) & 255;
2753 fo = mddev->new_layout & (1<<16);
2754
2755 if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks ||
2756 (mddev->new_layout >> 17)) {
2757 printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
2758 mdname(mddev), mddev->new_layout);
2759 goto out;
2760 }
2761
2762 err = -ENOMEM;
2763 conf = kzalloc(sizeof(conf_t), GFP_KERNEL);
2764 if (!conf)
2765 goto out;
2766
2767 conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks,
2768 GFP_KERNEL);
2769 if (!conf->mirrors)
2770 goto out;
2771
2772 conf->tmppage = alloc_page(GFP_KERNEL);
2773 if (!conf->tmppage)
2774 goto out;
2775
2776
2777 conf->raid_disks = mddev->raid_disks;
2778 conf->near_copies = nc;
2779 conf->far_copies = fc;
2780 conf->copies = nc*fc;
2781 conf->far_offset = fo;
2782 conf->chunk_mask = mddev->new_chunk_sectors - 1;
2783 conf->chunk_shift = ffz(~mddev->new_chunk_sectors);
2784
2785 conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
2786 r10bio_pool_free, conf);
2787 if (!conf->r10bio_pool)
2788 goto out;
2789
2790 size = mddev->dev_sectors >> conf->chunk_shift;
2791 sector_div(size, fc);
2792 size = size * conf->raid_disks;
2793 sector_div(size, nc);
2794 /* 'size' is now the number of chunks in the array */
2795 /* calculate "used chunks per device" in 'stride' */
2796 stride = size * conf->copies;
2797
2798 /* We need to round up when dividing by raid_disks to
2799 * get the stride size.
2800 */
2801 stride += conf->raid_disks - 1;
2802 sector_div(stride, conf->raid_disks);
2803
2804 conf->dev_sectors = stride << conf->chunk_shift;
2805
2806 if (fo)
2807 stride = 1;
2808 else
2809 sector_div(stride, fc);
2810 conf->stride = stride << conf->chunk_shift;
2811
2812
2813 spin_lock_init(&conf->device_lock);
2814 INIT_LIST_HEAD(&conf->retry_list);
2815
2816 spin_lock_init(&conf->resync_lock);
2817 init_waitqueue_head(&conf->wait_barrier);
2818
2819 conf->thread = md_register_thread(raid10d, mddev, NULL);
2820 if (!conf->thread)
2821 goto out;
2822
2823 conf->mddev = mddev;
2824 return conf;
2825
2826 out:
2827 printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n",
2828 mdname(mddev));
2829 if (conf) {
2830 if (conf->r10bio_pool)
2831 mempool_destroy(conf->r10bio_pool);
2832 kfree(conf->mirrors);
2833 safe_put_page(conf->tmppage);
2834 kfree(conf);
2835 }
2836 return ERR_PTR(err);
2837}
2838
2839static int run(mddev_t *mddev)
2840{
2841 conf_t *conf;
2842 int i, disk_idx, chunk_size;
2843 mirror_info_t *disk;
2844 mdk_rdev_t *rdev;
2845 sector_t size;
2846
2847 /*
2848 * copy the already verified devices into our private RAID10
2849 * bookkeeping area. [whatever we allocate in run(),
2850 * should be freed in stop()]
2851 */
2852
2853 if (mddev->private == NULL) {
2854 conf = setup_conf(mddev);
2855 if (IS_ERR(conf))
2856 return PTR_ERR(conf);
2857 mddev->private = conf;
2858 }
2859 conf = mddev->private;
2860 if (!conf)
2861 goto out;
2862
2863 mddev->thread = conf->thread;
2864 conf->thread = NULL;
2865
2866 chunk_size = mddev->chunk_sectors << 9;
2867 blk_queue_io_min(mddev->queue, chunk_size);
2868 if (conf->raid_disks % conf->near_copies)
2869 blk_queue_io_opt(mddev->queue, chunk_size * conf->raid_disks);
2870 else
2871 blk_queue_io_opt(mddev->queue, chunk_size *
2872 (conf->raid_disks / conf->near_copies));
2873
2874 list_for_each_entry(rdev, &mddev->disks, same_set) {
2875
2876 disk_idx = rdev->raid_disk;
2877 if (disk_idx >= conf->raid_disks
2878 || disk_idx < 0)
2879 continue;
2880 disk = conf->mirrors + disk_idx;
2881
2882 disk->rdev = rdev;
2883 disk_stack_limits(mddev->gendisk, rdev->bdev,
2884 rdev->data_offset << 9);
2885 /* as we don't honour merge_bvec_fn, we must never risk
2886 * violating it, so limit max_segments to 1 lying
2887 * within a single page.
2888 */
2889 if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
2890 blk_queue_max_segments(mddev->queue, 1);
2891 blk_queue_segment_boundary(mddev->queue,
2892 PAGE_CACHE_SIZE - 1);
2893 }
2894
2895 disk->head_position = 0;
2896 }
2897 /* need to check that every block has at least one working mirror */
2898 if (!enough(conf, -1)) {
2899 printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",
2900 mdname(mddev));
2901 goto out_free_conf;
2902 }
2903
2904 mddev->degraded = 0;
2905 for (i = 0; i < conf->raid_disks; i++) {
2906
2907 disk = conf->mirrors + i;
2908
2909 if (!disk->rdev ||
2910 !test_bit(In_sync, &disk->rdev->flags)) {
2911 disk->head_position = 0;
2912 mddev->degraded++;
2913 if (disk->rdev)
2914 conf->fullsync = 1;
2915 }
2916 }
2917
2918 if (mddev->recovery_cp != MaxSector)
2919 printk(KERN_NOTICE "md/raid10:%s: not clean"
2920 " -- starting background reconstruction\n",
2921 mdname(mddev));
2922 printk(KERN_INFO
2923 "md/raid10:%s: active with %d out of %d devices\n",
2924 mdname(mddev), conf->raid_disks - mddev->degraded,
2925 conf->raid_disks);
2926 /*
2927 * Ok, everything is just fine now
2928 */
2929 mddev->dev_sectors = conf->dev_sectors;
2930 size = raid10_size(mddev, 0, 0);
2931 md_set_array_sectors(mddev, size);
2932 mddev->resync_max_sectors = size;
2933
2934 mddev->queue->backing_dev_info.congested_fn = raid10_congested;
2935 mddev->queue->backing_dev_info.congested_data = mddev;
2936
2937 /* Calculate max read-ahead size.
2938 * We need to readahead at least twice a whole stripe....
2939 * maybe...
2940 */
2941 {
2942 int stripe = conf->raid_disks *
2943 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
2944 stripe /= conf->near_copies;
2945 if (mddev->queue->backing_dev_info.ra_pages < 2* stripe)
2946 mddev->queue->backing_dev_info.ra_pages = 2* stripe;
2947 }
2948
2949 if (conf->near_copies < conf->raid_disks)
2950 blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec);
2951
2952 if (md_integrity_register(mddev))
2953 goto out_free_conf;
2954
2955 return 0;
2956
2957out_free_conf:
2958 md_unregister_thread(&mddev->thread);
2959 if (conf->r10bio_pool)
2960 mempool_destroy(conf->r10bio_pool);
2961 safe_put_page(conf->tmppage);
2962 kfree(conf->mirrors);
2963 kfree(conf);
2964 mddev->private = NULL;
2965out:
2966 return -EIO;
2967}
2968
2969static int stop(mddev_t *mddev)
2970{
2971 conf_t *conf = mddev->private;
2972
2973 raise_barrier(conf, 0);
2974 lower_barrier(conf);
2975
2976 md_unregister_thread(&mddev->thread);
2977 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
2978 if (conf->r10bio_pool)
2979 mempool_destroy(conf->r10bio_pool);
2980 kfree(conf->mirrors);
2981 kfree(conf);
2982 mddev->private = NULL;
2983 return 0;
2984}
2985
2986static void raid10_quiesce(mddev_t *mddev, int state)
2987{
2988 conf_t *conf = mddev->private;
2989
2990 switch(state) {
2991 case 1:
2992 raise_barrier(conf, 0);
2993 break;
2994 case 0:
2995 lower_barrier(conf);
2996 break;
2997 }
2998}
2999
3000static void *raid10_takeover_raid0(mddev_t *mddev)
3001{
3002 mdk_rdev_t *rdev;
3003 conf_t *conf;
3004
3005 if (mddev->degraded > 0) {
3006 printk(KERN_ERR "md/raid10:%s: Error: degraded raid0!\n",
3007 mdname(mddev));
3008 return ERR_PTR(-EINVAL);
3009 }
3010
3011 /* Set new parameters */
3012 mddev->new_level = 10;
3013 /* new layout: far_copies = 1, near_copies = 2 */
3014 mddev->new_layout = (1<<8) + 2;
3015 mddev->new_chunk_sectors = mddev->chunk_sectors;
3016 mddev->delta_disks = mddev->raid_disks;
3017 mddev->raid_disks *= 2;
3018 /* make sure it will be not marked as dirty */
3019 mddev->recovery_cp = MaxSector;
3020
3021 conf = setup_conf(mddev);
3022 if (!IS_ERR(conf)) {
3023 list_for_each_entry(rdev, &mddev->disks, same_set)
3024 if (rdev->raid_disk >= 0)
3025 rdev->new_raid_disk = rdev->raid_disk * 2;
3026 conf->barrier = 1;
3027 }
3028
3029 return conf;
3030}
3031
3032static void *raid10_takeover(mddev_t *mddev)
3033{
3034 struct raid0_private_data *raid0_priv;
3035
3036 /* raid10 can take over:
3037 * raid0 - providing it has only two drives
3038 */
3039 if (mddev->level == 0) {
3040 /* for raid0 takeover only one zone is supported */
3041 raid0_priv = mddev->private;
3042 if (raid0_priv->nr_strip_zones > 1) {
3043 printk(KERN_ERR "md/raid10:%s: cannot takeover raid 0"
3044 " with more than one zone.\n",
3045 mdname(mddev));
3046 return ERR_PTR(-EINVAL);
3047 }
3048 return raid10_takeover_raid0(mddev);
3049 }
3050 return ERR_PTR(-EINVAL);
3051}
3052
3053static struct mdk_personality raid10_personality =
3054{
3055 .name = "raid10",
3056 .level = 10,
3057 .owner = THIS_MODULE,
3058 .make_request = make_request,
3059 .run = run,
3060 .stop = stop,
3061 .status = status,
3062 .error_handler = error,
3063 .hot_add_disk = raid10_add_disk,
3064 .hot_remove_disk= raid10_remove_disk,
3065 .spare_active = raid10_spare_active,
3066 .sync_request = sync_request,
3067 .quiesce = raid10_quiesce,
3068 .size = raid10_size,
3069 .takeover = raid10_takeover,
3070};
3071
3072static int __init raid_init(void)
3073{
3074 return register_md_personality(&raid10_personality);
3075}
3076
3077static void raid_exit(void)
3078{
3079 unregister_md_personality(&raid10_personality);
3080}
3081
3082module_init(raid_init);
3083module_exit(raid_exit);
3084MODULE_LICENSE("GPL");
3085MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
3086MODULE_ALIAS("md-personality-9"); /* RAID10 */
3087MODULE_ALIAS("md-raid10");
3088MODULE_ALIAS("md-level-10");
1/*
2 * raid10.c : Multiple Devices driver for Linux
3 *
4 * Copyright (C) 2000-2004 Neil Brown
5 *
6 * RAID-10 support for md.
7 *
8 * Base on code in raid1.c. See raid1.c for further copyright information.
9 *
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
14 * any later version.
15 *
16 * You should have received a copy of the GNU General Public License
17 * (for example /usr/src/linux/COPYING); if not, write to the Free
18 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#include <linux/slab.h>
22#include <linux/delay.h>
23#include <linux/blkdev.h>
24#include <linux/module.h>
25#include <linux/seq_file.h>
26#include <linux/ratelimit.h>
27#include <linux/kthread.h>
28#include <trace/events/block.h>
29#include "md.h"
30#include "raid10.h"
31#include "raid0.h"
32#include "bitmap.h"
33
34/*
35 * RAID10 provides a combination of RAID0 and RAID1 functionality.
36 * The layout of data is defined by
37 * chunk_size
38 * raid_disks
39 * near_copies (stored in low byte of layout)
40 * far_copies (stored in second byte of layout)
41 * far_offset (stored in bit 16 of layout )
42 * use_far_sets (stored in bit 17 of layout )
43 * use_far_sets_bugfixed (stored in bit 18 of layout )
44 *
45 * The data to be stored is divided into chunks using chunksize. Each device
46 * is divided into far_copies sections. In each section, chunks are laid out
47 * in a style similar to raid0, but near_copies copies of each chunk is stored
48 * (each on a different drive). The starting device for each section is offset
49 * near_copies from the starting device of the previous section. Thus there
50 * are (near_copies * far_copies) of each chunk, and each is on a different
51 * drive. near_copies and far_copies must be at least one, and their product
52 * is at most raid_disks.
53 *
54 * If far_offset is true, then the far_copies are handled a bit differently.
55 * The copies are still in different stripes, but instead of being very far
56 * apart on disk, there are adjacent stripes.
57 *
58 * The far and offset algorithms are handled slightly differently if
59 * 'use_far_sets' is true. In this case, the array's devices are grouped into
60 * sets that are (near_copies * far_copies) in size. The far copied stripes
61 * are still shifted by 'near_copies' devices, but this shifting stays confined
62 * to the set rather than the entire array. This is done to improve the number
63 * of device combinations that can fail without causing the array to fail.
64 * Example 'far' algorithm w/o 'use_far_sets' (each letter represents a chunk
65 * on a device):
66 * A B C D A B C D E
67 * ... ...
68 * D A B C E A B C D
69 * Example 'far' algorithm w/ 'use_far_sets' enabled (sets illustrated w/ []'s):
70 * [A B] [C D] [A B] [C D E]
71 * |...| |...| |...| | ... |
72 * [B A] [D C] [B A] [E C D]
73 */
74
75/*
76 * Number of guaranteed r10bios in case of extreme VM load:
77 */
78#define NR_RAID10_BIOS 256
79
80/* when we get a read error on a read-only array, we redirect to another
81 * device without failing the first device, or trying to over-write to
82 * correct the read error. To keep track of bad blocks on a per-bio
83 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
84 */
85#define IO_BLOCKED ((struct bio *)1)
86/* When we successfully write to a known bad-block, we need to remove the
87 * bad-block marking which must be done from process context. So we record
88 * the success by setting devs[n].bio to IO_MADE_GOOD
89 */
90#define IO_MADE_GOOD ((struct bio *)2)
91
92#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
93
94/* When there are this many requests queued to be written by
95 * the raid10 thread, we become 'congested' to provide back-pressure
96 * for writeback.
97 */
98static int max_queued_requests = 1024;
99
100static void allow_barrier(struct r10conf *conf);
101static void lower_barrier(struct r10conf *conf);
102static int _enough(struct r10conf *conf, int previous, int ignore);
103static int enough(struct r10conf *conf, int ignore);
104static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
105 int *skipped);
106static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio);
107static void end_reshape_write(struct bio *bio);
108static void end_reshape(struct r10conf *conf);
109
110#define raid10_log(md, fmt, args...) \
111 do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid10 " fmt, ##args); } while (0)
112
113static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
114{
115 struct r10conf *conf = data;
116 int size = offsetof(struct r10bio, devs[conf->copies]);
117
118 /* allocate a r10bio with room for raid_disks entries in the
119 * bios array */
120 return kzalloc(size, gfp_flags);
121}
122
123static void r10bio_pool_free(void *r10_bio, void *data)
124{
125 kfree(r10_bio);
126}
127
128/* Maximum size of each resync request */
129#define RESYNC_BLOCK_SIZE (64*1024)
130#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
131/* amount of memory to reserve for resync requests */
132#define RESYNC_WINDOW (1024*1024)
133/* maximum number of concurrent requests, memory permitting */
134#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
135
136/*
137 * When performing a resync, we need to read and compare, so
138 * we need as many pages are there are copies.
139 * When performing a recovery, we need 2 bios, one for read,
140 * one for write (we recover only one drive per r10buf)
141 *
142 */
143static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
144{
145 struct r10conf *conf = data;
146 struct page *page;
147 struct r10bio *r10_bio;
148 struct bio *bio;
149 int i, j;
150 int nalloc;
151
152 r10_bio = r10bio_pool_alloc(gfp_flags, conf);
153 if (!r10_bio)
154 return NULL;
155
156 if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery) ||
157 test_bit(MD_RECOVERY_RESHAPE, &conf->mddev->recovery))
158 nalloc = conf->copies; /* resync */
159 else
160 nalloc = 2; /* recovery */
161
162 /*
163 * Allocate bios.
164 */
165 for (j = nalloc ; j-- ; ) {
166 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
167 if (!bio)
168 goto out_free_bio;
169 r10_bio->devs[j].bio = bio;
170 if (!conf->have_replacement)
171 continue;
172 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
173 if (!bio)
174 goto out_free_bio;
175 r10_bio->devs[j].repl_bio = bio;
176 }
177 /*
178 * Allocate RESYNC_PAGES data pages and attach them
179 * where needed.
180 */
181 for (j = 0 ; j < nalloc; j++) {
182 struct bio *rbio = r10_bio->devs[j].repl_bio;
183 bio = r10_bio->devs[j].bio;
184 for (i = 0; i < RESYNC_PAGES; i++) {
185 if (j > 0 && !test_bit(MD_RECOVERY_SYNC,
186 &conf->mddev->recovery)) {
187 /* we can share bv_page's during recovery
188 * and reshape */
189 struct bio *rbio = r10_bio->devs[0].bio;
190 page = rbio->bi_io_vec[i].bv_page;
191 get_page(page);
192 } else
193 page = alloc_page(gfp_flags);
194 if (unlikely(!page))
195 goto out_free_pages;
196
197 bio->bi_io_vec[i].bv_page = page;
198 if (rbio)
199 rbio->bi_io_vec[i].bv_page = page;
200 }
201 }
202
203 return r10_bio;
204
205out_free_pages:
206 for ( ; i > 0 ; i--)
207 safe_put_page(bio->bi_io_vec[i-1].bv_page);
208 while (j--)
209 for (i = 0; i < RESYNC_PAGES ; i++)
210 safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
211 j = 0;
212out_free_bio:
213 for ( ; j < nalloc; j++) {
214 if (r10_bio->devs[j].bio)
215 bio_put(r10_bio->devs[j].bio);
216 if (r10_bio->devs[j].repl_bio)
217 bio_put(r10_bio->devs[j].repl_bio);
218 }
219 r10bio_pool_free(r10_bio, conf);
220 return NULL;
221}
222
223static void r10buf_pool_free(void *__r10_bio, void *data)
224{
225 int i;
226 struct r10conf *conf = data;
227 struct r10bio *r10bio = __r10_bio;
228 int j;
229
230 for (j=0; j < conf->copies; j++) {
231 struct bio *bio = r10bio->devs[j].bio;
232 if (bio) {
233 for (i = 0; i < RESYNC_PAGES; i++) {
234 safe_put_page(bio->bi_io_vec[i].bv_page);
235 bio->bi_io_vec[i].bv_page = NULL;
236 }
237 bio_put(bio);
238 }
239 bio = r10bio->devs[j].repl_bio;
240 if (bio)
241 bio_put(bio);
242 }
243 r10bio_pool_free(r10bio, conf);
244}
245
246static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio)
247{
248 int i;
249
250 for (i = 0; i < conf->copies; i++) {
251 struct bio **bio = & r10_bio->devs[i].bio;
252 if (!BIO_SPECIAL(*bio))
253 bio_put(*bio);
254 *bio = NULL;
255 bio = &r10_bio->devs[i].repl_bio;
256 if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio))
257 bio_put(*bio);
258 *bio = NULL;
259 }
260}
261
262static void free_r10bio(struct r10bio *r10_bio)
263{
264 struct r10conf *conf = r10_bio->mddev->private;
265
266 put_all_bios(conf, r10_bio);
267 mempool_free(r10_bio, conf->r10bio_pool);
268}
269
270static void put_buf(struct r10bio *r10_bio)
271{
272 struct r10conf *conf = r10_bio->mddev->private;
273
274 mempool_free(r10_bio, conf->r10buf_pool);
275
276 lower_barrier(conf);
277}
278
279static void reschedule_retry(struct r10bio *r10_bio)
280{
281 unsigned long flags;
282 struct mddev *mddev = r10_bio->mddev;
283 struct r10conf *conf = mddev->private;
284
285 spin_lock_irqsave(&conf->device_lock, flags);
286 list_add(&r10_bio->retry_list, &conf->retry_list);
287 conf->nr_queued ++;
288 spin_unlock_irqrestore(&conf->device_lock, flags);
289
290 /* wake up frozen array... */
291 wake_up(&conf->wait_barrier);
292
293 md_wakeup_thread(mddev->thread);
294}
295
296/*
297 * raid_end_bio_io() is called when we have finished servicing a mirrored
298 * operation and are ready to return a success/failure code to the buffer
299 * cache layer.
300 */
301static void raid_end_bio_io(struct r10bio *r10_bio)
302{
303 struct bio *bio = r10_bio->master_bio;
304 int done;
305 struct r10conf *conf = r10_bio->mddev->private;
306
307 if (bio->bi_phys_segments) {
308 unsigned long flags;
309 spin_lock_irqsave(&conf->device_lock, flags);
310 bio->bi_phys_segments--;
311 done = (bio->bi_phys_segments == 0);
312 spin_unlock_irqrestore(&conf->device_lock, flags);
313 } else
314 done = 1;
315 if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
316 bio->bi_error = -EIO;
317 if (done) {
318 bio_endio(bio);
319 /*
320 * Wake up any possible resync thread that waits for the device
321 * to go idle.
322 */
323 allow_barrier(conf);
324 }
325 free_r10bio(r10_bio);
326}
327
328/*
329 * Update disk head position estimator based on IRQ completion info.
330 */
331static inline void update_head_pos(int slot, struct r10bio *r10_bio)
332{
333 struct r10conf *conf = r10_bio->mddev->private;
334
335 conf->mirrors[r10_bio->devs[slot].devnum].head_position =
336 r10_bio->devs[slot].addr + (r10_bio->sectors);
337}
338
339/*
340 * Find the disk number which triggered given bio
341 */
342static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio,
343 struct bio *bio, int *slotp, int *replp)
344{
345 int slot;
346 int repl = 0;
347
348 for (slot = 0; slot < conf->copies; slot++) {
349 if (r10_bio->devs[slot].bio == bio)
350 break;
351 if (r10_bio->devs[slot].repl_bio == bio) {
352 repl = 1;
353 break;
354 }
355 }
356
357 BUG_ON(slot == conf->copies);
358 update_head_pos(slot, r10_bio);
359
360 if (slotp)
361 *slotp = slot;
362 if (replp)
363 *replp = repl;
364 return r10_bio->devs[slot].devnum;
365}
366
367static void raid10_end_read_request(struct bio *bio)
368{
369 int uptodate = !bio->bi_error;
370 struct r10bio *r10_bio = bio->bi_private;
371 int slot, dev;
372 struct md_rdev *rdev;
373 struct r10conf *conf = r10_bio->mddev->private;
374
375 slot = r10_bio->read_slot;
376 dev = r10_bio->devs[slot].devnum;
377 rdev = r10_bio->devs[slot].rdev;
378 /*
379 * this branch is our 'one mirror IO has finished' event handler:
380 */
381 update_head_pos(slot, r10_bio);
382
383 if (uptodate) {
384 /*
385 * Set R10BIO_Uptodate in our master bio, so that
386 * we will return a good error code to the higher
387 * levels even if IO on some other mirrored buffer fails.
388 *
389 * The 'master' represents the composite IO operation to
390 * user-side. So if something waits for IO, then it will
391 * wait for the 'master' bio.
392 */
393 set_bit(R10BIO_Uptodate, &r10_bio->state);
394 } else {
395 /* If all other devices that store this block have
396 * failed, we want to return the error upwards rather
397 * than fail the last device. Here we redefine
398 * "uptodate" to mean "Don't want to retry"
399 */
400 if (!_enough(conf, test_bit(R10BIO_Previous, &r10_bio->state),
401 rdev->raid_disk))
402 uptodate = 1;
403 }
404 if (uptodate) {
405 raid_end_bio_io(r10_bio);
406 rdev_dec_pending(rdev, conf->mddev);
407 } else {
408 /*
409 * oops, read error - keep the refcount on the rdev
410 */
411 char b[BDEVNAME_SIZE];
412 pr_err_ratelimited("md/raid10:%s: %s: rescheduling sector %llu\n",
413 mdname(conf->mddev),
414 bdevname(rdev->bdev, b),
415 (unsigned long long)r10_bio->sector);
416 set_bit(R10BIO_ReadError, &r10_bio->state);
417 reschedule_retry(r10_bio);
418 }
419}
420
421static void close_write(struct r10bio *r10_bio)
422{
423 /* clear the bitmap if all writes complete successfully */
424 bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
425 r10_bio->sectors,
426 !test_bit(R10BIO_Degraded, &r10_bio->state),
427 0);
428 md_write_end(r10_bio->mddev);
429}
430
431static void one_write_done(struct r10bio *r10_bio)
432{
433 if (atomic_dec_and_test(&r10_bio->remaining)) {
434 if (test_bit(R10BIO_WriteError, &r10_bio->state))
435 reschedule_retry(r10_bio);
436 else {
437 close_write(r10_bio);
438 if (test_bit(R10BIO_MadeGood, &r10_bio->state))
439 reschedule_retry(r10_bio);
440 else
441 raid_end_bio_io(r10_bio);
442 }
443 }
444}
445
446static void raid10_end_write_request(struct bio *bio)
447{
448 struct r10bio *r10_bio = bio->bi_private;
449 int dev;
450 int dec_rdev = 1;
451 struct r10conf *conf = r10_bio->mddev->private;
452 int slot, repl;
453 struct md_rdev *rdev = NULL;
454 struct bio *to_put = NULL;
455 bool discard_error;
456
457 discard_error = bio->bi_error && bio_op(bio) == REQ_OP_DISCARD;
458
459 dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
460
461 if (repl)
462 rdev = conf->mirrors[dev].replacement;
463 if (!rdev) {
464 smp_rmb();
465 repl = 0;
466 rdev = conf->mirrors[dev].rdev;
467 }
468 /*
469 * this branch is our 'one mirror IO has finished' event handler:
470 */
471 if (bio->bi_error && !discard_error) {
472 if (repl)
473 /* Never record new bad blocks to replacement,
474 * just fail it.
475 */
476 md_error(rdev->mddev, rdev);
477 else {
478 set_bit(WriteErrorSeen, &rdev->flags);
479 if (!test_and_set_bit(WantReplacement, &rdev->flags))
480 set_bit(MD_RECOVERY_NEEDED,
481 &rdev->mddev->recovery);
482
483 dec_rdev = 0;
484 if (test_bit(FailFast, &rdev->flags) &&
485 (bio->bi_opf & MD_FAILFAST)) {
486 md_error(rdev->mddev, rdev);
487 if (!test_bit(Faulty, &rdev->flags))
488 /* This is the only remaining device,
489 * We need to retry the write without
490 * FailFast
491 */
492 set_bit(R10BIO_WriteError, &r10_bio->state);
493 else {
494 r10_bio->devs[slot].bio = NULL;
495 to_put = bio;
496 dec_rdev = 1;
497 }
498 } else
499 set_bit(R10BIO_WriteError, &r10_bio->state);
500 }
501 } else {
502 /*
503 * Set R10BIO_Uptodate in our master bio, so that
504 * we will return a good error code for to the higher
505 * levels even if IO on some other mirrored buffer fails.
506 *
507 * The 'master' represents the composite IO operation to
508 * user-side. So if something waits for IO, then it will
509 * wait for the 'master' bio.
510 */
511 sector_t first_bad;
512 int bad_sectors;
513
514 /*
515 * Do not set R10BIO_Uptodate if the current device is
516 * rebuilding or Faulty. This is because we cannot use
517 * such device for properly reading the data back (we could
518 * potentially use it, if the current write would have felt
519 * before rdev->recovery_offset, but for simplicity we don't
520 * check this here.
521 */
522 if (test_bit(In_sync, &rdev->flags) &&
523 !test_bit(Faulty, &rdev->flags))
524 set_bit(R10BIO_Uptodate, &r10_bio->state);
525
526 /* Maybe we can clear some bad blocks. */
527 if (is_badblock(rdev,
528 r10_bio->devs[slot].addr,
529 r10_bio->sectors,
530 &first_bad, &bad_sectors) && !discard_error) {
531 bio_put(bio);
532 if (repl)
533 r10_bio->devs[slot].repl_bio = IO_MADE_GOOD;
534 else
535 r10_bio->devs[slot].bio = IO_MADE_GOOD;
536 dec_rdev = 0;
537 set_bit(R10BIO_MadeGood, &r10_bio->state);
538 }
539 }
540
541 /*
542 *
543 * Let's see if all mirrored write operations have finished
544 * already.
545 */
546 one_write_done(r10_bio);
547 if (dec_rdev)
548 rdev_dec_pending(rdev, conf->mddev);
549 if (to_put)
550 bio_put(to_put);
551}
552
553/*
554 * RAID10 layout manager
555 * As well as the chunksize and raid_disks count, there are two
556 * parameters: near_copies and far_copies.
557 * near_copies * far_copies must be <= raid_disks.
558 * Normally one of these will be 1.
559 * If both are 1, we get raid0.
560 * If near_copies == raid_disks, we get raid1.
561 *
562 * Chunks are laid out in raid0 style with near_copies copies of the
563 * first chunk, followed by near_copies copies of the next chunk and
564 * so on.
565 * If far_copies > 1, then after 1/far_copies of the array has been assigned
566 * as described above, we start again with a device offset of near_copies.
567 * So we effectively have another copy of the whole array further down all
568 * the drives, but with blocks on different drives.
569 * With this layout, and block is never stored twice on the one device.
570 *
571 * raid10_find_phys finds the sector offset of a given virtual sector
572 * on each device that it is on.
573 *
574 * raid10_find_virt does the reverse mapping, from a device and a
575 * sector offset to a virtual address
576 */
577
578static void __raid10_find_phys(struct geom *geo, struct r10bio *r10bio)
579{
580 int n,f;
581 sector_t sector;
582 sector_t chunk;
583 sector_t stripe;
584 int dev;
585 int slot = 0;
586 int last_far_set_start, last_far_set_size;
587
588 last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
589 last_far_set_start *= geo->far_set_size;
590
591 last_far_set_size = geo->far_set_size;
592 last_far_set_size += (geo->raid_disks % geo->far_set_size);
593
594 /* now calculate first sector/dev */
595 chunk = r10bio->sector >> geo->chunk_shift;
596 sector = r10bio->sector & geo->chunk_mask;
597
598 chunk *= geo->near_copies;
599 stripe = chunk;
600 dev = sector_div(stripe, geo->raid_disks);
601 if (geo->far_offset)
602 stripe *= geo->far_copies;
603
604 sector += stripe << geo->chunk_shift;
605
606 /* and calculate all the others */
607 for (n = 0; n < geo->near_copies; n++) {
608 int d = dev;
609 int set;
610 sector_t s = sector;
611 r10bio->devs[slot].devnum = d;
612 r10bio->devs[slot].addr = s;
613 slot++;
614
615 for (f = 1; f < geo->far_copies; f++) {
616 set = d / geo->far_set_size;
617 d += geo->near_copies;
618
619 if ((geo->raid_disks % geo->far_set_size) &&
620 (d > last_far_set_start)) {
621 d -= last_far_set_start;
622 d %= last_far_set_size;
623 d += last_far_set_start;
624 } else {
625 d %= geo->far_set_size;
626 d += geo->far_set_size * set;
627 }
628 s += geo->stride;
629 r10bio->devs[slot].devnum = d;
630 r10bio->devs[slot].addr = s;
631 slot++;
632 }
633 dev++;
634 if (dev >= geo->raid_disks) {
635 dev = 0;
636 sector += (geo->chunk_mask + 1);
637 }
638 }
639}
640
641static void raid10_find_phys(struct r10conf *conf, struct r10bio *r10bio)
642{
643 struct geom *geo = &conf->geo;
644
645 if (conf->reshape_progress != MaxSector &&
646 ((r10bio->sector >= conf->reshape_progress) !=
647 conf->mddev->reshape_backwards)) {
648 set_bit(R10BIO_Previous, &r10bio->state);
649 geo = &conf->prev;
650 } else
651 clear_bit(R10BIO_Previous, &r10bio->state);
652
653 __raid10_find_phys(geo, r10bio);
654}
655
656static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev)
657{
658 sector_t offset, chunk, vchunk;
659 /* Never use conf->prev as this is only called during resync
660 * or recovery, so reshape isn't happening
661 */
662 struct geom *geo = &conf->geo;
663 int far_set_start = (dev / geo->far_set_size) * geo->far_set_size;
664 int far_set_size = geo->far_set_size;
665 int last_far_set_start;
666
667 if (geo->raid_disks % geo->far_set_size) {
668 last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
669 last_far_set_start *= geo->far_set_size;
670
671 if (dev >= last_far_set_start) {
672 far_set_size = geo->far_set_size;
673 far_set_size += (geo->raid_disks % geo->far_set_size);
674 far_set_start = last_far_set_start;
675 }
676 }
677
678 offset = sector & geo->chunk_mask;
679 if (geo->far_offset) {
680 int fc;
681 chunk = sector >> geo->chunk_shift;
682 fc = sector_div(chunk, geo->far_copies);
683 dev -= fc * geo->near_copies;
684 if (dev < far_set_start)
685 dev += far_set_size;
686 } else {
687 while (sector >= geo->stride) {
688 sector -= geo->stride;
689 if (dev < (geo->near_copies + far_set_start))
690 dev += far_set_size - geo->near_copies;
691 else
692 dev -= geo->near_copies;
693 }
694 chunk = sector >> geo->chunk_shift;
695 }
696 vchunk = chunk * geo->raid_disks + dev;
697 sector_div(vchunk, geo->near_copies);
698 return (vchunk << geo->chunk_shift) + offset;
699}
700
701/*
702 * This routine returns the disk from which the requested read should
703 * be done. There is a per-array 'next expected sequential IO' sector
704 * number - if this matches on the next IO then we use the last disk.
705 * There is also a per-disk 'last know head position' sector that is
706 * maintained from IRQ contexts, both the normal and the resync IO
707 * completion handlers update this position correctly. If there is no
708 * perfect sequential match then we pick the disk whose head is closest.
709 *
710 * If there are 2 mirrors in the same 2 devices, performance degrades
711 * because position is mirror, not device based.
712 *
713 * The rdev for the device selected will have nr_pending incremented.
714 */
715
716/*
717 * FIXME: possibly should rethink readbalancing and do it differently
718 * depending on near_copies / far_copies geometry.
719 */
720static struct md_rdev *read_balance(struct r10conf *conf,
721 struct r10bio *r10_bio,
722 int *max_sectors)
723{
724 const sector_t this_sector = r10_bio->sector;
725 int disk, slot;
726 int sectors = r10_bio->sectors;
727 int best_good_sectors;
728 sector_t new_distance, best_dist;
729 struct md_rdev *best_rdev, *rdev = NULL;
730 int do_balance;
731 int best_slot;
732 struct geom *geo = &conf->geo;
733
734 raid10_find_phys(conf, r10_bio);
735 rcu_read_lock();
736 sectors = r10_bio->sectors;
737 best_slot = -1;
738 best_rdev = NULL;
739 best_dist = MaxSector;
740 best_good_sectors = 0;
741 do_balance = 1;
742 clear_bit(R10BIO_FailFast, &r10_bio->state);
743 /*
744 * Check if we can balance. We can balance on the whole
745 * device if no resync is going on (recovery is ok), or below
746 * the resync window. We take the first readable disk when
747 * above the resync window.
748 */
749 if (conf->mddev->recovery_cp < MaxSector
750 && (this_sector + sectors >= conf->next_resync))
751 do_balance = 0;
752
753 for (slot = 0; slot < conf->copies ; slot++) {
754 sector_t first_bad;
755 int bad_sectors;
756 sector_t dev_sector;
757
758 if (r10_bio->devs[slot].bio == IO_BLOCKED)
759 continue;
760 disk = r10_bio->devs[slot].devnum;
761 rdev = rcu_dereference(conf->mirrors[disk].replacement);
762 if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
763 r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
764 rdev = rcu_dereference(conf->mirrors[disk].rdev);
765 if (rdev == NULL ||
766 test_bit(Faulty, &rdev->flags))
767 continue;
768 if (!test_bit(In_sync, &rdev->flags) &&
769 r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
770 continue;
771
772 dev_sector = r10_bio->devs[slot].addr;
773 if (is_badblock(rdev, dev_sector, sectors,
774 &first_bad, &bad_sectors)) {
775 if (best_dist < MaxSector)
776 /* Already have a better slot */
777 continue;
778 if (first_bad <= dev_sector) {
779 /* Cannot read here. If this is the
780 * 'primary' device, then we must not read
781 * beyond 'bad_sectors' from another device.
782 */
783 bad_sectors -= (dev_sector - first_bad);
784 if (!do_balance && sectors > bad_sectors)
785 sectors = bad_sectors;
786 if (best_good_sectors > sectors)
787 best_good_sectors = sectors;
788 } else {
789 sector_t good_sectors =
790 first_bad - dev_sector;
791 if (good_sectors > best_good_sectors) {
792 best_good_sectors = good_sectors;
793 best_slot = slot;
794 best_rdev = rdev;
795 }
796 if (!do_balance)
797 /* Must read from here */
798 break;
799 }
800 continue;
801 } else
802 best_good_sectors = sectors;
803
804 if (!do_balance)
805 break;
806
807 if (best_slot >= 0)
808 /* At least 2 disks to choose from so failfast is OK */
809 set_bit(R10BIO_FailFast, &r10_bio->state);
810 /* This optimisation is debatable, and completely destroys
811 * sequential read speed for 'far copies' arrays. So only
812 * keep it for 'near' arrays, and review those later.
813 */
814 if (geo->near_copies > 1 && !atomic_read(&rdev->nr_pending))
815 new_distance = 0;
816
817 /* for far > 1 always use the lowest address */
818 else if (geo->far_copies > 1)
819 new_distance = r10_bio->devs[slot].addr;
820 else
821 new_distance = abs(r10_bio->devs[slot].addr -
822 conf->mirrors[disk].head_position);
823 if (new_distance < best_dist) {
824 best_dist = new_distance;
825 best_slot = slot;
826 best_rdev = rdev;
827 }
828 }
829 if (slot >= conf->copies) {
830 slot = best_slot;
831 rdev = best_rdev;
832 }
833
834 if (slot >= 0) {
835 atomic_inc(&rdev->nr_pending);
836 r10_bio->read_slot = slot;
837 } else
838 rdev = NULL;
839 rcu_read_unlock();
840 *max_sectors = best_good_sectors;
841
842 return rdev;
843}
844
845static int raid10_congested(struct mddev *mddev, int bits)
846{
847 struct r10conf *conf = mddev->private;
848 int i, ret = 0;
849
850 if ((bits & (1 << WB_async_congested)) &&
851 conf->pending_count >= max_queued_requests)
852 return 1;
853
854 rcu_read_lock();
855 for (i = 0;
856 (i < conf->geo.raid_disks || i < conf->prev.raid_disks)
857 && ret == 0;
858 i++) {
859 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
860 if (rdev && !test_bit(Faulty, &rdev->flags)) {
861 struct request_queue *q = bdev_get_queue(rdev->bdev);
862
863 ret |= bdi_congested(&q->backing_dev_info, bits);
864 }
865 }
866 rcu_read_unlock();
867 return ret;
868}
869
870static void flush_pending_writes(struct r10conf *conf)
871{
872 /* Any writes that have been queued but are awaiting
873 * bitmap updates get flushed here.
874 */
875 spin_lock_irq(&conf->device_lock);
876
877 if (conf->pending_bio_list.head) {
878 struct bio *bio;
879 bio = bio_list_get(&conf->pending_bio_list);
880 conf->pending_count = 0;
881 spin_unlock_irq(&conf->device_lock);
882 /* flush any pending bitmap writes to disk
883 * before proceeding w/ I/O */
884 bitmap_unplug(conf->mddev->bitmap);
885 wake_up(&conf->wait_barrier);
886
887 while (bio) { /* submit pending writes */
888 struct bio *next = bio->bi_next;
889 struct md_rdev *rdev = (void*)bio->bi_bdev;
890 bio->bi_next = NULL;
891 bio->bi_bdev = rdev->bdev;
892 if (test_bit(Faulty, &rdev->flags)) {
893 bio->bi_error = -EIO;
894 bio_endio(bio);
895 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
896 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
897 /* Just ignore it */
898 bio_endio(bio);
899 else
900 generic_make_request(bio);
901 bio = next;
902 }
903 } else
904 spin_unlock_irq(&conf->device_lock);
905}
906
907/* Barriers....
908 * Sometimes we need to suspend IO while we do something else,
909 * either some resync/recovery, or reconfigure the array.
910 * To do this we raise a 'barrier'.
911 * The 'barrier' is a counter that can be raised multiple times
912 * to count how many activities are happening which preclude
913 * normal IO.
914 * We can only raise the barrier if there is no pending IO.
915 * i.e. if nr_pending == 0.
916 * We choose only to raise the barrier if no-one is waiting for the
917 * barrier to go down. This means that as soon as an IO request
918 * is ready, no other operations which require a barrier will start
919 * until the IO request has had a chance.
920 *
921 * So: regular IO calls 'wait_barrier'. When that returns there
922 * is no backgroup IO happening, It must arrange to call
923 * allow_barrier when it has finished its IO.
924 * backgroup IO calls must call raise_barrier. Once that returns
925 * there is no normal IO happeing. It must arrange to call
926 * lower_barrier when the particular background IO completes.
927 */
928
929static void raise_barrier(struct r10conf *conf, int force)
930{
931 BUG_ON(force && !conf->barrier);
932 spin_lock_irq(&conf->resync_lock);
933
934 /* Wait until no block IO is waiting (unless 'force') */
935 wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
936 conf->resync_lock);
937
938 /* block any new IO from starting */
939 conf->barrier++;
940
941 /* Now wait for all pending IO to complete */
942 wait_event_lock_irq(conf->wait_barrier,
943 !atomic_read(&conf->nr_pending) && conf->barrier < RESYNC_DEPTH,
944 conf->resync_lock);
945
946 spin_unlock_irq(&conf->resync_lock);
947}
948
949static void lower_barrier(struct r10conf *conf)
950{
951 unsigned long flags;
952 spin_lock_irqsave(&conf->resync_lock, flags);
953 conf->barrier--;
954 spin_unlock_irqrestore(&conf->resync_lock, flags);
955 wake_up(&conf->wait_barrier);
956}
957
958static void wait_barrier(struct r10conf *conf)
959{
960 spin_lock_irq(&conf->resync_lock);
961 if (conf->barrier) {
962 conf->nr_waiting++;
963 /* Wait for the barrier to drop.
964 * However if there are already pending
965 * requests (preventing the barrier from
966 * rising completely), and the
967 * pre-process bio queue isn't empty,
968 * then don't wait, as we need to empty
969 * that queue to get the nr_pending
970 * count down.
971 */
972 raid10_log(conf->mddev, "wait barrier");
973 wait_event_lock_irq(conf->wait_barrier,
974 !conf->barrier ||
975 (atomic_read(&conf->nr_pending) &&
976 current->bio_list &&
977 (!bio_list_empty(¤t->bio_list[0]) ||
978 !bio_list_empty(¤t->bio_list[1]))),
979 conf->resync_lock);
980 conf->nr_waiting--;
981 if (!conf->nr_waiting)
982 wake_up(&conf->wait_barrier);
983 }
984 atomic_inc(&conf->nr_pending);
985 spin_unlock_irq(&conf->resync_lock);
986}
987
988static void allow_barrier(struct r10conf *conf)
989{
990 if ((atomic_dec_and_test(&conf->nr_pending)) ||
991 (conf->array_freeze_pending))
992 wake_up(&conf->wait_barrier);
993}
994
995static void freeze_array(struct r10conf *conf, int extra)
996{
997 /* stop syncio and normal IO and wait for everything to
998 * go quiet.
999 * We increment barrier and nr_waiting, and then
1000 * wait until nr_pending match nr_queued+extra
1001 * This is called in the context of one normal IO request
1002 * that has failed. Thus any sync request that might be pending
1003 * will be blocked by nr_pending, and we need to wait for
1004 * pending IO requests to complete or be queued for re-try.
1005 * Thus the number queued (nr_queued) plus this request (extra)
1006 * must match the number of pending IOs (nr_pending) before
1007 * we continue.
1008 */
1009 spin_lock_irq(&conf->resync_lock);
1010 conf->array_freeze_pending++;
1011 conf->barrier++;
1012 conf->nr_waiting++;
1013 wait_event_lock_irq_cmd(conf->wait_barrier,
1014 atomic_read(&conf->nr_pending) == conf->nr_queued+extra,
1015 conf->resync_lock,
1016 flush_pending_writes(conf));
1017
1018 conf->array_freeze_pending--;
1019 spin_unlock_irq(&conf->resync_lock);
1020}
1021
1022static void unfreeze_array(struct r10conf *conf)
1023{
1024 /* reverse the effect of the freeze */
1025 spin_lock_irq(&conf->resync_lock);
1026 conf->barrier--;
1027 conf->nr_waiting--;
1028 wake_up(&conf->wait_barrier);
1029 spin_unlock_irq(&conf->resync_lock);
1030}
1031
1032static sector_t choose_data_offset(struct r10bio *r10_bio,
1033 struct md_rdev *rdev)
1034{
1035 if (!test_bit(MD_RECOVERY_RESHAPE, &rdev->mddev->recovery) ||
1036 test_bit(R10BIO_Previous, &r10_bio->state))
1037 return rdev->data_offset;
1038 else
1039 return rdev->new_data_offset;
1040}
1041
1042struct raid10_plug_cb {
1043 struct blk_plug_cb cb;
1044 struct bio_list pending;
1045 int pending_cnt;
1046};
1047
1048static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
1049{
1050 struct raid10_plug_cb *plug = container_of(cb, struct raid10_plug_cb,
1051 cb);
1052 struct mddev *mddev = plug->cb.data;
1053 struct r10conf *conf = mddev->private;
1054 struct bio *bio;
1055
1056 if (from_schedule || current->bio_list) {
1057 spin_lock_irq(&conf->device_lock);
1058 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1059 conf->pending_count += plug->pending_cnt;
1060 spin_unlock_irq(&conf->device_lock);
1061 wake_up(&conf->wait_barrier);
1062 md_wakeup_thread(mddev->thread);
1063 kfree(plug);
1064 return;
1065 }
1066
1067 /* we aren't scheduling, so we can do the write-out directly. */
1068 bio = bio_list_get(&plug->pending);
1069 bitmap_unplug(mddev->bitmap);
1070 wake_up(&conf->wait_barrier);
1071
1072 while (bio) { /* submit pending writes */
1073 struct bio *next = bio->bi_next;
1074 struct md_rdev *rdev = (void*)bio->bi_bdev;
1075 bio->bi_next = NULL;
1076 bio->bi_bdev = rdev->bdev;
1077 if (test_bit(Faulty, &rdev->flags)) {
1078 bio->bi_error = -EIO;
1079 bio_endio(bio);
1080 } else if (unlikely((bio_op(bio) == REQ_OP_DISCARD) &&
1081 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
1082 /* Just ignore it */
1083 bio_endio(bio);
1084 else
1085 generic_make_request(bio);
1086 bio = next;
1087 }
1088 kfree(plug);
1089}
1090
1091static void raid10_read_request(struct mddev *mddev, struct bio *bio,
1092 struct r10bio *r10_bio)
1093{
1094 struct r10conf *conf = mddev->private;
1095 struct bio *read_bio;
1096 const int op = bio_op(bio);
1097 const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
1098 int sectors_handled;
1099 int max_sectors;
1100 sector_t sectors;
1101 struct md_rdev *rdev;
1102 int slot;
1103
1104 /*
1105 * Register the new request and wait if the reconstruction
1106 * thread has put up a bar for new requests.
1107 * Continue immediately if no resync is active currently.
1108 */
1109 wait_barrier(conf);
1110
1111 sectors = bio_sectors(bio);
1112 while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
1113 bio->bi_iter.bi_sector < conf->reshape_progress &&
1114 bio->bi_iter.bi_sector + sectors > conf->reshape_progress) {
1115 /*
1116 * IO spans the reshape position. Need to wait for reshape to
1117 * pass
1118 */
1119 raid10_log(conf->mddev, "wait reshape");
1120 allow_barrier(conf);
1121 wait_event(conf->wait_barrier,
1122 conf->reshape_progress <= bio->bi_iter.bi_sector ||
1123 conf->reshape_progress >= bio->bi_iter.bi_sector +
1124 sectors);
1125 wait_barrier(conf);
1126 }
1127
1128read_again:
1129 rdev = read_balance(conf, r10_bio, &max_sectors);
1130 if (!rdev) {
1131 raid_end_bio_io(r10_bio);
1132 return;
1133 }
1134 slot = r10_bio->read_slot;
1135
1136 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1137 bio_trim(read_bio, r10_bio->sector - bio->bi_iter.bi_sector,
1138 max_sectors);
1139
1140 r10_bio->devs[slot].bio = read_bio;
1141 r10_bio->devs[slot].rdev = rdev;
1142
1143 read_bio->bi_iter.bi_sector = r10_bio->devs[slot].addr +
1144 choose_data_offset(r10_bio, rdev);
1145 read_bio->bi_bdev = rdev->bdev;
1146 read_bio->bi_end_io = raid10_end_read_request;
1147 bio_set_op_attrs(read_bio, op, do_sync);
1148 if (test_bit(FailFast, &rdev->flags) &&
1149 test_bit(R10BIO_FailFast, &r10_bio->state))
1150 read_bio->bi_opf |= MD_FAILFAST;
1151 read_bio->bi_private = r10_bio;
1152
1153 if (mddev->gendisk)
1154 trace_block_bio_remap(bdev_get_queue(read_bio->bi_bdev),
1155 read_bio, disk_devt(mddev->gendisk),
1156 r10_bio->sector);
1157 if (max_sectors < r10_bio->sectors) {
1158 /*
1159 * Could not read all from this device, so we will need another
1160 * r10_bio.
1161 */
1162 sectors_handled = (r10_bio->sector + max_sectors
1163 - bio->bi_iter.bi_sector);
1164 r10_bio->sectors = max_sectors;
1165 spin_lock_irq(&conf->device_lock);
1166 if (bio->bi_phys_segments == 0)
1167 bio->bi_phys_segments = 2;
1168 else
1169 bio->bi_phys_segments++;
1170 spin_unlock_irq(&conf->device_lock);
1171 /*
1172 * Cannot call generic_make_request directly as that will be
1173 * queued in __generic_make_request and subsequent
1174 * mempool_alloc might block waiting for it. so hand bio over
1175 * to raid10d.
1176 */
1177 reschedule_retry(r10_bio);
1178
1179 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1180
1181 r10_bio->master_bio = bio;
1182 r10_bio->sectors = bio_sectors(bio) - sectors_handled;
1183 r10_bio->state = 0;
1184 r10_bio->mddev = mddev;
1185 r10_bio->sector = bio->bi_iter.bi_sector + sectors_handled;
1186 goto read_again;
1187 } else
1188 generic_make_request(read_bio);
1189 return;
1190}
1191
1192static void raid10_write_request(struct mddev *mddev, struct bio *bio,
1193 struct r10bio *r10_bio)
1194{
1195 struct r10conf *conf = mddev->private;
1196 int i;
1197 const int op = bio_op(bio);
1198 const unsigned long do_sync = (bio->bi_opf & REQ_SYNC);
1199 const unsigned long do_fua = (bio->bi_opf & REQ_FUA);
1200 unsigned long flags;
1201 struct md_rdev *blocked_rdev;
1202 struct blk_plug_cb *cb;
1203 struct raid10_plug_cb *plug = NULL;
1204 sector_t sectors;
1205 int sectors_handled;
1206 int max_sectors;
1207
1208 md_write_start(mddev, bio);
1209
1210 /*
1211 * Register the new request and wait if the reconstruction
1212 * thread has put up a bar for new requests.
1213 * Continue immediately if no resync is active currently.
1214 */
1215 wait_barrier(conf);
1216
1217 sectors = bio_sectors(bio);
1218 while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
1219 bio->bi_iter.bi_sector < conf->reshape_progress &&
1220 bio->bi_iter.bi_sector + sectors > conf->reshape_progress) {
1221 /*
1222 * IO spans the reshape position. Need to wait for reshape to
1223 * pass
1224 */
1225 raid10_log(conf->mddev, "wait reshape");
1226 allow_barrier(conf);
1227 wait_event(conf->wait_barrier,
1228 conf->reshape_progress <= bio->bi_iter.bi_sector ||
1229 conf->reshape_progress >= bio->bi_iter.bi_sector +
1230 sectors);
1231 wait_barrier(conf);
1232 }
1233
1234 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
1235 (mddev->reshape_backwards
1236 ? (bio->bi_iter.bi_sector < conf->reshape_safe &&
1237 bio->bi_iter.bi_sector + sectors > conf->reshape_progress)
1238 : (bio->bi_iter.bi_sector + sectors > conf->reshape_safe &&
1239 bio->bi_iter.bi_sector < conf->reshape_progress))) {
1240 /* Need to update reshape_position in metadata */
1241 mddev->reshape_position = conf->reshape_progress;
1242 set_mask_bits(&mddev->sb_flags, 0,
1243 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1244 md_wakeup_thread(mddev->thread);
1245 raid10_log(conf->mddev, "wait reshape metadata");
1246 wait_event(mddev->sb_wait,
1247 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
1248
1249 conf->reshape_safe = mddev->reshape_position;
1250 }
1251
1252 if (conf->pending_count >= max_queued_requests) {
1253 md_wakeup_thread(mddev->thread);
1254 raid10_log(mddev, "wait queued");
1255 wait_event(conf->wait_barrier,
1256 conf->pending_count < max_queued_requests);
1257 }
1258 /* first select target devices under rcu_lock and
1259 * inc refcount on their rdev. Record them by setting
1260 * bios[x] to bio
1261 * If there are known/acknowledged bad blocks on any device
1262 * on which we have seen a write error, we want to avoid
1263 * writing to those blocks. This potentially requires several
1264 * writes to write around the bad blocks. Each set of writes
1265 * gets its own r10_bio with a set of bios attached. The number
1266 * of r10_bios is recored in bio->bi_phys_segments just as with
1267 * the read case.
1268 */
1269
1270 r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
1271 raid10_find_phys(conf, r10_bio);
1272retry_write:
1273 blocked_rdev = NULL;
1274 rcu_read_lock();
1275 max_sectors = r10_bio->sectors;
1276
1277 for (i = 0; i < conf->copies; i++) {
1278 int d = r10_bio->devs[i].devnum;
1279 struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
1280 struct md_rdev *rrdev = rcu_dereference(
1281 conf->mirrors[d].replacement);
1282 if (rdev == rrdev)
1283 rrdev = NULL;
1284 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1285 atomic_inc(&rdev->nr_pending);
1286 blocked_rdev = rdev;
1287 break;
1288 }
1289 if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
1290 atomic_inc(&rrdev->nr_pending);
1291 blocked_rdev = rrdev;
1292 break;
1293 }
1294 if (rdev && (test_bit(Faulty, &rdev->flags)))
1295 rdev = NULL;
1296 if (rrdev && (test_bit(Faulty, &rrdev->flags)))
1297 rrdev = NULL;
1298
1299 r10_bio->devs[i].bio = NULL;
1300 r10_bio->devs[i].repl_bio = NULL;
1301
1302 if (!rdev && !rrdev) {
1303 set_bit(R10BIO_Degraded, &r10_bio->state);
1304 continue;
1305 }
1306 if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
1307 sector_t first_bad;
1308 sector_t dev_sector = r10_bio->devs[i].addr;
1309 int bad_sectors;
1310 int is_bad;
1311
1312 is_bad = is_badblock(rdev, dev_sector, max_sectors,
1313 &first_bad, &bad_sectors);
1314 if (is_bad < 0) {
1315 /* Mustn't write here until the bad block
1316 * is acknowledged
1317 */
1318 atomic_inc(&rdev->nr_pending);
1319 set_bit(BlockedBadBlocks, &rdev->flags);
1320 blocked_rdev = rdev;
1321 break;
1322 }
1323 if (is_bad && first_bad <= dev_sector) {
1324 /* Cannot write here at all */
1325 bad_sectors -= (dev_sector - first_bad);
1326 if (bad_sectors < max_sectors)
1327 /* Mustn't write more than bad_sectors
1328 * to other devices yet
1329 */
1330 max_sectors = bad_sectors;
1331 /* We don't set R10BIO_Degraded as that
1332 * only applies if the disk is missing,
1333 * so it might be re-added, and we want to
1334 * know to recover this chunk.
1335 * In this case the device is here, and the
1336 * fact that this chunk is not in-sync is
1337 * recorded in the bad block log.
1338 */
1339 continue;
1340 }
1341 if (is_bad) {
1342 int good_sectors = first_bad - dev_sector;
1343 if (good_sectors < max_sectors)
1344 max_sectors = good_sectors;
1345 }
1346 }
1347 if (rdev) {
1348 r10_bio->devs[i].bio = bio;
1349 atomic_inc(&rdev->nr_pending);
1350 }
1351 if (rrdev) {
1352 r10_bio->devs[i].repl_bio = bio;
1353 atomic_inc(&rrdev->nr_pending);
1354 }
1355 }
1356 rcu_read_unlock();
1357
1358 if (unlikely(blocked_rdev)) {
1359 /* Have to wait for this device to get unblocked, then retry */
1360 int j;
1361 int d;
1362
1363 for (j = 0; j < i; j++) {
1364 if (r10_bio->devs[j].bio) {
1365 d = r10_bio->devs[j].devnum;
1366 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
1367 }
1368 if (r10_bio->devs[j].repl_bio) {
1369 struct md_rdev *rdev;
1370 d = r10_bio->devs[j].devnum;
1371 rdev = conf->mirrors[d].replacement;
1372 if (!rdev) {
1373 /* Race with remove_disk */
1374 smp_mb();
1375 rdev = conf->mirrors[d].rdev;
1376 }
1377 rdev_dec_pending(rdev, mddev);
1378 }
1379 }
1380 allow_barrier(conf);
1381 raid10_log(conf->mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
1382 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1383 wait_barrier(conf);
1384 goto retry_write;
1385 }
1386
1387 if (max_sectors < r10_bio->sectors) {
1388 /* We are splitting this into multiple parts, so
1389 * we need to prepare for allocating another r10_bio.
1390 */
1391 r10_bio->sectors = max_sectors;
1392 spin_lock_irq(&conf->device_lock);
1393 if (bio->bi_phys_segments == 0)
1394 bio->bi_phys_segments = 2;
1395 else
1396 bio->bi_phys_segments++;
1397 spin_unlock_irq(&conf->device_lock);
1398 }
1399 sectors_handled = r10_bio->sector + max_sectors -
1400 bio->bi_iter.bi_sector;
1401
1402 atomic_set(&r10_bio->remaining, 1);
1403 bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
1404
1405 for (i = 0; i < conf->copies; i++) {
1406 struct bio *mbio;
1407 int d = r10_bio->devs[i].devnum;
1408 if (r10_bio->devs[i].bio) {
1409 struct md_rdev *rdev = conf->mirrors[d].rdev;
1410 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1411 bio_trim(mbio, r10_bio->sector - bio->bi_iter.bi_sector,
1412 max_sectors);
1413 r10_bio->devs[i].bio = mbio;
1414
1415 mbio->bi_iter.bi_sector = (r10_bio->devs[i].addr+
1416 choose_data_offset(r10_bio, rdev));
1417 mbio->bi_bdev = rdev->bdev;
1418 mbio->bi_end_io = raid10_end_write_request;
1419 bio_set_op_attrs(mbio, op, do_sync | do_fua);
1420 if (test_bit(FailFast, &conf->mirrors[d].rdev->flags) &&
1421 enough(conf, d))
1422 mbio->bi_opf |= MD_FAILFAST;
1423 mbio->bi_private = r10_bio;
1424
1425 if (conf->mddev->gendisk)
1426 trace_block_bio_remap(bdev_get_queue(mbio->bi_bdev),
1427 mbio, disk_devt(conf->mddev->gendisk),
1428 r10_bio->sector);
1429 /* flush_pending_writes() needs access to the rdev so...*/
1430 mbio->bi_bdev = (void*)rdev;
1431
1432 atomic_inc(&r10_bio->remaining);
1433
1434 cb = blk_check_plugged(raid10_unplug, mddev,
1435 sizeof(*plug));
1436 if (cb)
1437 plug = container_of(cb, struct raid10_plug_cb,
1438 cb);
1439 else
1440 plug = NULL;
1441 spin_lock_irqsave(&conf->device_lock, flags);
1442 if (plug) {
1443 bio_list_add(&plug->pending, mbio);
1444 plug->pending_cnt++;
1445 } else {
1446 bio_list_add(&conf->pending_bio_list, mbio);
1447 conf->pending_count++;
1448 }
1449 spin_unlock_irqrestore(&conf->device_lock, flags);
1450 if (!plug)
1451 md_wakeup_thread(mddev->thread);
1452 }
1453
1454 if (r10_bio->devs[i].repl_bio) {
1455 struct md_rdev *rdev = conf->mirrors[d].replacement;
1456 if (rdev == NULL) {
1457 /* Replacement just got moved to main 'rdev' */
1458 smp_mb();
1459 rdev = conf->mirrors[d].rdev;
1460 }
1461 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1462 bio_trim(mbio, r10_bio->sector - bio->bi_iter.bi_sector,
1463 max_sectors);
1464 r10_bio->devs[i].repl_bio = mbio;
1465
1466 mbio->bi_iter.bi_sector = (r10_bio->devs[i].addr +
1467 choose_data_offset(r10_bio, rdev));
1468 mbio->bi_bdev = rdev->bdev;
1469 mbio->bi_end_io = raid10_end_write_request;
1470 bio_set_op_attrs(mbio, op, do_sync | do_fua);
1471 mbio->bi_private = r10_bio;
1472
1473 if (conf->mddev->gendisk)
1474 trace_block_bio_remap(bdev_get_queue(mbio->bi_bdev),
1475 mbio, disk_devt(conf->mddev->gendisk),
1476 r10_bio->sector);
1477 /* flush_pending_writes() needs access to the rdev so...*/
1478 mbio->bi_bdev = (void*)rdev;
1479
1480 atomic_inc(&r10_bio->remaining);
1481 spin_lock_irqsave(&conf->device_lock, flags);
1482 bio_list_add(&conf->pending_bio_list, mbio);
1483 conf->pending_count++;
1484 spin_unlock_irqrestore(&conf->device_lock, flags);
1485 if (!mddev_check_plugged(mddev))
1486 md_wakeup_thread(mddev->thread);
1487 }
1488 }
1489
1490 /* Don't remove the bias on 'remaining' (one_write_done) until
1491 * after checking if we need to go around again.
1492 */
1493
1494 if (sectors_handled < bio_sectors(bio)) {
1495 one_write_done(r10_bio);
1496 /* We need another r10_bio. It has already been counted
1497 * in bio->bi_phys_segments.
1498 */
1499 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1500
1501 r10_bio->master_bio = bio;
1502 r10_bio->sectors = bio_sectors(bio) - sectors_handled;
1503
1504 r10_bio->mddev = mddev;
1505 r10_bio->sector = bio->bi_iter.bi_sector + sectors_handled;
1506 r10_bio->state = 0;
1507 goto retry_write;
1508 }
1509 one_write_done(r10_bio);
1510}
1511
1512static void __make_request(struct mddev *mddev, struct bio *bio)
1513{
1514 struct r10conf *conf = mddev->private;
1515 struct r10bio *r10_bio;
1516
1517 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1518
1519 r10_bio->master_bio = bio;
1520 r10_bio->sectors = bio_sectors(bio);
1521
1522 r10_bio->mddev = mddev;
1523 r10_bio->sector = bio->bi_iter.bi_sector;
1524 r10_bio->state = 0;
1525
1526 /*
1527 * We might need to issue multiple reads to different devices if there
1528 * are bad blocks around, so we keep track of the number of reads in
1529 * bio->bi_phys_segments. If this is 0, there is only one r10_bio and
1530 * no locking will be needed when the request completes. If it is
1531 * non-zero, then it is the number of not-completed requests.
1532 */
1533 bio->bi_phys_segments = 0;
1534 bio_clear_flag(bio, BIO_SEG_VALID);
1535
1536 if (bio_data_dir(bio) == READ)
1537 raid10_read_request(mddev, bio, r10_bio);
1538 else
1539 raid10_write_request(mddev, bio, r10_bio);
1540}
1541
1542static void raid10_make_request(struct mddev *mddev, struct bio *bio)
1543{
1544 struct r10conf *conf = mddev->private;
1545 sector_t chunk_mask = (conf->geo.chunk_mask & conf->prev.chunk_mask);
1546 int chunk_sects = chunk_mask + 1;
1547
1548 struct bio *split;
1549
1550 if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
1551 md_flush_request(mddev, bio);
1552 return;
1553 }
1554
1555 do {
1556
1557 /*
1558 * If this request crosses a chunk boundary, we need to split
1559 * it.
1560 */
1561 if (unlikely((bio->bi_iter.bi_sector & chunk_mask) +
1562 bio_sectors(bio) > chunk_sects
1563 && (conf->geo.near_copies < conf->geo.raid_disks
1564 || conf->prev.near_copies <
1565 conf->prev.raid_disks))) {
1566 split = bio_split(bio, chunk_sects -
1567 (bio->bi_iter.bi_sector &
1568 (chunk_sects - 1)),
1569 GFP_NOIO, fs_bio_set);
1570 bio_chain(split, bio);
1571 } else {
1572 split = bio;
1573 }
1574
1575 /*
1576 * If a bio is splitted, the first part of bio will pass
1577 * barrier but the bio is queued in current->bio_list (see
1578 * generic_make_request). If there is a raise_barrier() called
1579 * here, the second part of bio can't pass barrier. But since
1580 * the first part bio isn't dispatched to underlaying disks
1581 * yet, the barrier is never released, hence raise_barrier will
1582 * alays wait. We have a deadlock.
1583 * Note, this only happens in read path. For write path, the
1584 * first part of bio is dispatched in a schedule() call
1585 * (because of blk plug) or offloaded to raid10d.
1586 * Quitting from the function immediately can change the bio
1587 * order queued in bio_list and avoid the deadlock.
1588 */
1589 __make_request(mddev, split);
1590 if (split != bio && bio_data_dir(bio) == READ) {
1591 generic_make_request(bio);
1592 break;
1593 }
1594 } while (split != bio);
1595
1596 /* In case raid10d snuck in to freeze_array */
1597 wake_up(&conf->wait_barrier);
1598}
1599
1600static void raid10_status(struct seq_file *seq, struct mddev *mddev)
1601{
1602 struct r10conf *conf = mddev->private;
1603 int i;
1604
1605 if (conf->geo.near_copies < conf->geo.raid_disks)
1606 seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
1607 if (conf->geo.near_copies > 1)
1608 seq_printf(seq, " %d near-copies", conf->geo.near_copies);
1609 if (conf->geo.far_copies > 1) {
1610 if (conf->geo.far_offset)
1611 seq_printf(seq, " %d offset-copies", conf->geo.far_copies);
1612 else
1613 seq_printf(seq, " %d far-copies", conf->geo.far_copies);
1614 if (conf->geo.far_set_size != conf->geo.raid_disks)
1615 seq_printf(seq, " %d devices per set", conf->geo.far_set_size);
1616 }
1617 seq_printf(seq, " [%d/%d] [", conf->geo.raid_disks,
1618 conf->geo.raid_disks - mddev->degraded);
1619 rcu_read_lock();
1620 for (i = 0; i < conf->geo.raid_disks; i++) {
1621 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
1622 seq_printf(seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
1623 }
1624 rcu_read_unlock();
1625 seq_printf(seq, "]");
1626}
1627
1628/* check if there are enough drives for
1629 * every block to appear on atleast one.
1630 * Don't consider the device numbered 'ignore'
1631 * as we might be about to remove it.
1632 */
1633static int _enough(struct r10conf *conf, int previous, int ignore)
1634{
1635 int first = 0;
1636 int has_enough = 0;
1637 int disks, ncopies;
1638 if (previous) {
1639 disks = conf->prev.raid_disks;
1640 ncopies = conf->prev.near_copies;
1641 } else {
1642 disks = conf->geo.raid_disks;
1643 ncopies = conf->geo.near_copies;
1644 }
1645
1646 rcu_read_lock();
1647 do {
1648 int n = conf->copies;
1649 int cnt = 0;
1650 int this = first;
1651 while (n--) {
1652 struct md_rdev *rdev;
1653 if (this != ignore &&
1654 (rdev = rcu_dereference(conf->mirrors[this].rdev)) &&
1655 test_bit(In_sync, &rdev->flags))
1656 cnt++;
1657 this = (this+1) % disks;
1658 }
1659 if (cnt == 0)
1660 goto out;
1661 first = (first + ncopies) % disks;
1662 } while (first != 0);
1663 has_enough = 1;
1664out:
1665 rcu_read_unlock();
1666 return has_enough;
1667}
1668
1669static int enough(struct r10conf *conf, int ignore)
1670{
1671 /* when calling 'enough', both 'prev' and 'geo' must
1672 * be stable.
1673 * This is ensured if ->reconfig_mutex or ->device_lock
1674 * is held.
1675 */
1676 return _enough(conf, 0, ignore) &&
1677 _enough(conf, 1, ignore);
1678}
1679
1680static void raid10_error(struct mddev *mddev, struct md_rdev *rdev)
1681{
1682 char b[BDEVNAME_SIZE];
1683 struct r10conf *conf = mddev->private;
1684 unsigned long flags;
1685
1686 /*
1687 * If it is not operational, then we have already marked it as dead
1688 * else if it is the last working disks, ignore the error, let the
1689 * next level up know.
1690 * else mark the drive as failed
1691 */
1692 spin_lock_irqsave(&conf->device_lock, flags);
1693 if (test_bit(In_sync, &rdev->flags)
1694 && !enough(conf, rdev->raid_disk)) {
1695 /*
1696 * Don't fail the drive, just return an IO error.
1697 */
1698 spin_unlock_irqrestore(&conf->device_lock, flags);
1699 return;
1700 }
1701 if (test_and_clear_bit(In_sync, &rdev->flags))
1702 mddev->degraded++;
1703 /*
1704 * If recovery is running, make sure it aborts.
1705 */
1706 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1707 set_bit(Blocked, &rdev->flags);
1708 set_bit(Faulty, &rdev->flags);
1709 set_mask_bits(&mddev->sb_flags, 0,
1710 BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING));
1711 spin_unlock_irqrestore(&conf->device_lock, flags);
1712 pr_crit("md/raid10:%s: Disk failure on %s, disabling device.\n"
1713 "md/raid10:%s: Operation continuing on %d devices.\n",
1714 mdname(mddev), bdevname(rdev->bdev, b),
1715 mdname(mddev), conf->geo.raid_disks - mddev->degraded);
1716}
1717
1718static void print_conf(struct r10conf *conf)
1719{
1720 int i;
1721 struct md_rdev *rdev;
1722
1723 pr_debug("RAID10 conf printout:\n");
1724 if (!conf) {
1725 pr_debug("(!conf)\n");
1726 return;
1727 }
1728 pr_debug(" --- wd:%d rd:%d\n", conf->geo.raid_disks - conf->mddev->degraded,
1729 conf->geo.raid_disks);
1730
1731 /* This is only called with ->reconfix_mutex held, so
1732 * rcu protection of rdev is not needed */
1733 for (i = 0; i < conf->geo.raid_disks; i++) {
1734 char b[BDEVNAME_SIZE];
1735 rdev = conf->mirrors[i].rdev;
1736 if (rdev)
1737 pr_debug(" disk %d, wo:%d, o:%d, dev:%s\n",
1738 i, !test_bit(In_sync, &rdev->flags),
1739 !test_bit(Faulty, &rdev->flags),
1740 bdevname(rdev->bdev,b));
1741 }
1742}
1743
1744static void close_sync(struct r10conf *conf)
1745{
1746 wait_barrier(conf);
1747 allow_barrier(conf);
1748
1749 mempool_destroy(conf->r10buf_pool);
1750 conf->r10buf_pool = NULL;
1751}
1752
1753static int raid10_spare_active(struct mddev *mddev)
1754{
1755 int i;
1756 struct r10conf *conf = mddev->private;
1757 struct raid10_info *tmp;
1758 int count = 0;
1759 unsigned long flags;
1760
1761 /*
1762 * Find all non-in_sync disks within the RAID10 configuration
1763 * and mark them in_sync
1764 */
1765 for (i = 0; i < conf->geo.raid_disks; i++) {
1766 tmp = conf->mirrors + i;
1767 if (tmp->replacement
1768 && tmp->replacement->recovery_offset == MaxSector
1769 && !test_bit(Faulty, &tmp->replacement->flags)
1770 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
1771 /* Replacement has just become active */
1772 if (!tmp->rdev
1773 || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
1774 count++;
1775 if (tmp->rdev) {
1776 /* Replaced device not technically faulty,
1777 * but we need to be sure it gets removed
1778 * and never re-added.
1779 */
1780 set_bit(Faulty, &tmp->rdev->flags);
1781 sysfs_notify_dirent_safe(
1782 tmp->rdev->sysfs_state);
1783 }
1784 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
1785 } else if (tmp->rdev
1786 && tmp->rdev->recovery_offset == MaxSector
1787 && !test_bit(Faulty, &tmp->rdev->flags)
1788 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
1789 count++;
1790 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
1791 }
1792 }
1793 spin_lock_irqsave(&conf->device_lock, flags);
1794 mddev->degraded -= count;
1795 spin_unlock_irqrestore(&conf->device_lock, flags);
1796
1797 print_conf(conf);
1798 return count;
1799}
1800
1801static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1802{
1803 struct r10conf *conf = mddev->private;
1804 int err = -EEXIST;
1805 int mirror;
1806 int first = 0;
1807 int last = conf->geo.raid_disks - 1;
1808
1809 if (mddev->recovery_cp < MaxSector)
1810 /* only hot-add to in-sync arrays, as recovery is
1811 * very different from resync
1812 */
1813 return -EBUSY;
1814 if (rdev->saved_raid_disk < 0 && !_enough(conf, 1, -1))
1815 return -EINVAL;
1816
1817 if (md_integrity_add_rdev(rdev, mddev))
1818 return -ENXIO;
1819
1820 if (rdev->raid_disk >= 0)
1821 first = last = rdev->raid_disk;
1822
1823 if (rdev->saved_raid_disk >= first &&
1824 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1825 mirror = rdev->saved_raid_disk;
1826 else
1827 mirror = first;
1828 for ( ; mirror <= last ; mirror++) {
1829 struct raid10_info *p = &conf->mirrors[mirror];
1830 if (p->recovery_disabled == mddev->recovery_disabled)
1831 continue;
1832 if (p->rdev) {
1833 if (!test_bit(WantReplacement, &p->rdev->flags) ||
1834 p->replacement != NULL)
1835 continue;
1836 clear_bit(In_sync, &rdev->flags);
1837 set_bit(Replacement, &rdev->flags);
1838 rdev->raid_disk = mirror;
1839 err = 0;
1840 if (mddev->gendisk)
1841 disk_stack_limits(mddev->gendisk, rdev->bdev,
1842 rdev->data_offset << 9);
1843 conf->fullsync = 1;
1844 rcu_assign_pointer(p->replacement, rdev);
1845 break;
1846 }
1847
1848 if (mddev->gendisk)
1849 disk_stack_limits(mddev->gendisk, rdev->bdev,
1850 rdev->data_offset << 9);
1851
1852 p->head_position = 0;
1853 p->recovery_disabled = mddev->recovery_disabled - 1;
1854 rdev->raid_disk = mirror;
1855 err = 0;
1856 if (rdev->saved_raid_disk != mirror)
1857 conf->fullsync = 1;
1858 rcu_assign_pointer(p->rdev, rdev);
1859 break;
1860 }
1861 if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
1862 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
1863
1864 print_conf(conf);
1865 return err;
1866}
1867
1868static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1869{
1870 struct r10conf *conf = mddev->private;
1871 int err = 0;
1872 int number = rdev->raid_disk;
1873 struct md_rdev **rdevp;
1874 struct raid10_info *p = conf->mirrors + number;
1875
1876 print_conf(conf);
1877 if (rdev == p->rdev)
1878 rdevp = &p->rdev;
1879 else if (rdev == p->replacement)
1880 rdevp = &p->replacement;
1881 else
1882 return 0;
1883
1884 if (test_bit(In_sync, &rdev->flags) ||
1885 atomic_read(&rdev->nr_pending)) {
1886 err = -EBUSY;
1887 goto abort;
1888 }
1889 /* Only remove non-faulty devices if recovery
1890 * is not possible.
1891 */
1892 if (!test_bit(Faulty, &rdev->flags) &&
1893 mddev->recovery_disabled != p->recovery_disabled &&
1894 (!p->replacement || p->replacement == rdev) &&
1895 number < conf->geo.raid_disks &&
1896 enough(conf, -1)) {
1897 err = -EBUSY;
1898 goto abort;
1899 }
1900 *rdevp = NULL;
1901 if (!test_bit(RemoveSynchronized, &rdev->flags)) {
1902 synchronize_rcu();
1903 if (atomic_read(&rdev->nr_pending)) {
1904 /* lost the race, try later */
1905 err = -EBUSY;
1906 *rdevp = rdev;
1907 goto abort;
1908 }
1909 }
1910 if (p->replacement) {
1911 /* We must have just cleared 'rdev' */
1912 p->rdev = p->replacement;
1913 clear_bit(Replacement, &p->replacement->flags);
1914 smp_mb(); /* Make sure other CPUs may see both as identical
1915 * but will never see neither -- if they are careful.
1916 */
1917 p->replacement = NULL;
1918 clear_bit(WantReplacement, &rdev->flags);
1919 } else
1920 /* We might have just remove the Replacement as faulty
1921 * Clear the flag just in case
1922 */
1923 clear_bit(WantReplacement, &rdev->flags);
1924
1925 err = md_integrity_register(mddev);
1926
1927abort:
1928
1929 print_conf(conf);
1930 return err;
1931}
1932
1933static void end_sync_read(struct bio *bio)
1934{
1935 struct r10bio *r10_bio = bio->bi_private;
1936 struct r10conf *conf = r10_bio->mddev->private;
1937 int d;
1938
1939 if (bio == r10_bio->master_bio) {
1940 /* this is a reshape read */
1941 d = r10_bio->read_slot; /* really the read dev */
1942 } else
1943 d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
1944
1945 if (!bio->bi_error)
1946 set_bit(R10BIO_Uptodate, &r10_bio->state);
1947 else
1948 /* The write handler will notice the lack of
1949 * R10BIO_Uptodate and record any errors etc
1950 */
1951 atomic_add(r10_bio->sectors,
1952 &conf->mirrors[d].rdev->corrected_errors);
1953
1954 /* for reconstruct, we always reschedule after a read.
1955 * for resync, only after all reads
1956 */
1957 rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
1958 if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
1959 atomic_dec_and_test(&r10_bio->remaining)) {
1960 /* we have read all the blocks,
1961 * do the comparison in process context in raid10d
1962 */
1963 reschedule_retry(r10_bio);
1964 }
1965}
1966
1967static void end_sync_request(struct r10bio *r10_bio)
1968{
1969 struct mddev *mddev = r10_bio->mddev;
1970
1971 while (atomic_dec_and_test(&r10_bio->remaining)) {
1972 if (r10_bio->master_bio == NULL) {
1973 /* the primary of several recovery bios */
1974 sector_t s = r10_bio->sectors;
1975 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
1976 test_bit(R10BIO_WriteError, &r10_bio->state))
1977 reschedule_retry(r10_bio);
1978 else
1979 put_buf(r10_bio);
1980 md_done_sync(mddev, s, 1);
1981 break;
1982 } else {
1983 struct r10bio *r10_bio2 = (struct r10bio *)r10_bio->master_bio;
1984 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
1985 test_bit(R10BIO_WriteError, &r10_bio->state))
1986 reschedule_retry(r10_bio);
1987 else
1988 put_buf(r10_bio);
1989 r10_bio = r10_bio2;
1990 }
1991 }
1992}
1993
1994static void end_sync_write(struct bio *bio)
1995{
1996 struct r10bio *r10_bio = bio->bi_private;
1997 struct mddev *mddev = r10_bio->mddev;
1998 struct r10conf *conf = mddev->private;
1999 int d;
2000 sector_t first_bad;
2001 int bad_sectors;
2002 int slot;
2003 int repl;
2004 struct md_rdev *rdev = NULL;
2005
2006 d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
2007 if (repl)
2008 rdev = conf->mirrors[d].replacement;
2009 else
2010 rdev = conf->mirrors[d].rdev;
2011
2012 if (bio->bi_error) {
2013 if (repl)
2014 md_error(mddev, rdev);
2015 else {
2016 set_bit(WriteErrorSeen, &rdev->flags);
2017 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2018 set_bit(MD_RECOVERY_NEEDED,
2019 &rdev->mddev->recovery);
2020 set_bit(R10BIO_WriteError, &r10_bio->state);
2021 }
2022 } else if (is_badblock(rdev,
2023 r10_bio->devs[slot].addr,
2024 r10_bio->sectors,
2025 &first_bad, &bad_sectors))
2026 set_bit(R10BIO_MadeGood, &r10_bio->state);
2027
2028 rdev_dec_pending(rdev, mddev);
2029
2030 end_sync_request(r10_bio);
2031}
2032
2033/*
2034 * Note: sync and recover and handled very differently for raid10
2035 * This code is for resync.
2036 * For resync, we read through virtual addresses and read all blocks.
2037 * If there is any error, we schedule a write. The lowest numbered
2038 * drive is authoritative.
2039 * However requests come for physical address, so we need to map.
2040 * For every physical address there are raid_disks/copies virtual addresses,
2041 * which is always are least one, but is not necessarly an integer.
2042 * This means that a physical address can span multiple chunks, so we may
2043 * have to submit multiple io requests for a single sync request.
2044 */
2045/*
2046 * We check if all blocks are in-sync and only write to blocks that
2047 * aren't in sync
2048 */
2049static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
2050{
2051 struct r10conf *conf = mddev->private;
2052 int i, first;
2053 struct bio *tbio, *fbio;
2054 int vcnt;
2055
2056 atomic_set(&r10_bio->remaining, 1);
2057
2058 /* find the first device with a block */
2059 for (i=0; i<conf->copies; i++)
2060 if (!r10_bio->devs[i].bio->bi_error)
2061 break;
2062
2063 if (i == conf->copies)
2064 goto done;
2065
2066 first = i;
2067 fbio = r10_bio->devs[i].bio;
2068 fbio->bi_iter.bi_size = r10_bio->sectors << 9;
2069 fbio->bi_iter.bi_idx = 0;
2070
2071 vcnt = (r10_bio->sectors + (PAGE_SIZE >> 9) - 1) >> (PAGE_SHIFT - 9);
2072 /* now find blocks with errors */
2073 for (i=0 ; i < conf->copies ; i++) {
2074 int j, d;
2075 struct md_rdev *rdev;
2076
2077 tbio = r10_bio->devs[i].bio;
2078
2079 if (tbio->bi_end_io != end_sync_read)
2080 continue;
2081 if (i == first)
2082 continue;
2083 d = r10_bio->devs[i].devnum;
2084 rdev = conf->mirrors[d].rdev;
2085 if (!r10_bio->devs[i].bio->bi_error) {
2086 /* We know that the bi_io_vec layout is the same for
2087 * both 'first' and 'i', so we just compare them.
2088 * All vec entries are PAGE_SIZE;
2089 */
2090 int sectors = r10_bio->sectors;
2091 for (j = 0; j < vcnt; j++) {
2092 int len = PAGE_SIZE;
2093 if (sectors < (len / 512))
2094 len = sectors * 512;
2095 if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
2096 page_address(tbio->bi_io_vec[j].bv_page),
2097 len))
2098 break;
2099 sectors -= len/512;
2100 }
2101 if (j == vcnt)
2102 continue;
2103 atomic64_add(r10_bio->sectors, &mddev->resync_mismatches);
2104 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
2105 /* Don't fix anything. */
2106 continue;
2107 } else if (test_bit(FailFast, &rdev->flags)) {
2108 /* Just give up on this device */
2109 md_error(rdev->mddev, rdev);
2110 continue;
2111 }
2112 /* Ok, we need to write this bio, either to correct an
2113 * inconsistency or to correct an unreadable block.
2114 * First we need to fixup bv_offset, bv_len and
2115 * bi_vecs, as the read request might have corrupted these
2116 */
2117 bio_reset(tbio);
2118
2119 tbio->bi_vcnt = vcnt;
2120 tbio->bi_iter.bi_size = fbio->bi_iter.bi_size;
2121 tbio->bi_private = r10_bio;
2122 tbio->bi_iter.bi_sector = r10_bio->devs[i].addr;
2123 tbio->bi_end_io = end_sync_write;
2124 bio_set_op_attrs(tbio, REQ_OP_WRITE, 0);
2125
2126 bio_copy_data(tbio, fbio);
2127
2128 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
2129 atomic_inc(&r10_bio->remaining);
2130 md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(tbio));
2131
2132 if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
2133 tbio->bi_opf |= MD_FAILFAST;
2134 tbio->bi_iter.bi_sector += conf->mirrors[d].rdev->data_offset;
2135 tbio->bi_bdev = conf->mirrors[d].rdev->bdev;
2136 generic_make_request(tbio);
2137 }
2138
2139 /* Now write out to any replacement devices
2140 * that are active
2141 */
2142 for (i = 0; i < conf->copies; i++) {
2143 int d;
2144
2145 tbio = r10_bio->devs[i].repl_bio;
2146 if (!tbio || !tbio->bi_end_io)
2147 continue;
2148 if (r10_bio->devs[i].bio->bi_end_io != end_sync_write
2149 && r10_bio->devs[i].bio != fbio)
2150 bio_copy_data(tbio, fbio);
2151 d = r10_bio->devs[i].devnum;
2152 atomic_inc(&r10_bio->remaining);
2153 md_sync_acct(conf->mirrors[d].replacement->bdev,
2154 bio_sectors(tbio));
2155 generic_make_request(tbio);
2156 }
2157
2158done:
2159 if (atomic_dec_and_test(&r10_bio->remaining)) {
2160 md_done_sync(mddev, r10_bio->sectors, 1);
2161 put_buf(r10_bio);
2162 }
2163}
2164
2165/*
2166 * Now for the recovery code.
2167 * Recovery happens across physical sectors.
2168 * We recover all non-is_sync drives by finding the virtual address of
2169 * each, and then choose a working drive that also has that virt address.
2170 * There is a separate r10_bio for each non-in_sync drive.
2171 * Only the first two slots are in use. The first for reading,
2172 * The second for writing.
2173 *
2174 */
2175static void fix_recovery_read_error(struct r10bio *r10_bio)
2176{
2177 /* We got a read error during recovery.
2178 * We repeat the read in smaller page-sized sections.
2179 * If a read succeeds, write it to the new device or record
2180 * a bad block if we cannot.
2181 * If a read fails, record a bad block on both old and
2182 * new devices.
2183 */
2184 struct mddev *mddev = r10_bio->mddev;
2185 struct r10conf *conf = mddev->private;
2186 struct bio *bio = r10_bio->devs[0].bio;
2187 sector_t sect = 0;
2188 int sectors = r10_bio->sectors;
2189 int idx = 0;
2190 int dr = r10_bio->devs[0].devnum;
2191 int dw = r10_bio->devs[1].devnum;
2192
2193 while (sectors) {
2194 int s = sectors;
2195 struct md_rdev *rdev;
2196 sector_t addr;
2197 int ok;
2198
2199 if (s > (PAGE_SIZE>>9))
2200 s = PAGE_SIZE >> 9;
2201
2202 rdev = conf->mirrors[dr].rdev;
2203 addr = r10_bio->devs[0].addr + sect,
2204 ok = sync_page_io(rdev,
2205 addr,
2206 s << 9,
2207 bio->bi_io_vec[idx].bv_page,
2208 REQ_OP_READ, 0, false);
2209 if (ok) {
2210 rdev = conf->mirrors[dw].rdev;
2211 addr = r10_bio->devs[1].addr + sect;
2212 ok = sync_page_io(rdev,
2213 addr,
2214 s << 9,
2215 bio->bi_io_vec[idx].bv_page,
2216 REQ_OP_WRITE, 0, false);
2217 if (!ok) {
2218 set_bit(WriteErrorSeen, &rdev->flags);
2219 if (!test_and_set_bit(WantReplacement,
2220 &rdev->flags))
2221 set_bit(MD_RECOVERY_NEEDED,
2222 &rdev->mddev->recovery);
2223 }
2224 }
2225 if (!ok) {
2226 /* We don't worry if we cannot set a bad block -
2227 * it really is bad so there is no loss in not
2228 * recording it yet
2229 */
2230 rdev_set_badblocks(rdev, addr, s, 0);
2231
2232 if (rdev != conf->mirrors[dw].rdev) {
2233 /* need bad block on destination too */
2234 struct md_rdev *rdev2 = conf->mirrors[dw].rdev;
2235 addr = r10_bio->devs[1].addr + sect;
2236 ok = rdev_set_badblocks(rdev2, addr, s, 0);
2237 if (!ok) {
2238 /* just abort the recovery */
2239 pr_notice("md/raid10:%s: recovery aborted due to read error\n",
2240 mdname(mddev));
2241
2242 conf->mirrors[dw].recovery_disabled
2243 = mddev->recovery_disabled;
2244 set_bit(MD_RECOVERY_INTR,
2245 &mddev->recovery);
2246 break;
2247 }
2248 }
2249 }
2250
2251 sectors -= s;
2252 sect += s;
2253 idx++;
2254 }
2255}
2256
2257static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
2258{
2259 struct r10conf *conf = mddev->private;
2260 int d;
2261 struct bio *wbio, *wbio2;
2262
2263 if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
2264 fix_recovery_read_error(r10_bio);
2265 end_sync_request(r10_bio);
2266 return;
2267 }
2268
2269 /*
2270 * share the pages with the first bio
2271 * and submit the write request
2272 */
2273 d = r10_bio->devs[1].devnum;
2274 wbio = r10_bio->devs[1].bio;
2275 wbio2 = r10_bio->devs[1].repl_bio;
2276 /* Need to test wbio2->bi_end_io before we call
2277 * generic_make_request as if the former is NULL,
2278 * the latter is free to free wbio2.
2279 */
2280 if (wbio2 && !wbio2->bi_end_io)
2281 wbio2 = NULL;
2282 if (wbio->bi_end_io) {
2283 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
2284 md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(wbio));
2285 generic_make_request(wbio);
2286 }
2287 if (wbio2) {
2288 atomic_inc(&conf->mirrors[d].replacement->nr_pending);
2289 md_sync_acct(conf->mirrors[d].replacement->bdev,
2290 bio_sectors(wbio2));
2291 generic_make_request(wbio2);
2292 }
2293}
2294
2295/*
2296 * Used by fix_read_error() to decay the per rdev read_errors.
2297 * We halve the read error count for every hour that has elapsed
2298 * since the last recorded read error.
2299 *
2300 */
2301static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)
2302{
2303 long cur_time_mon;
2304 unsigned long hours_since_last;
2305 unsigned int read_errors = atomic_read(&rdev->read_errors);
2306
2307 cur_time_mon = ktime_get_seconds();
2308
2309 if (rdev->last_read_error == 0) {
2310 /* first time we've seen a read error */
2311 rdev->last_read_error = cur_time_mon;
2312 return;
2313 }
2314
2315 hours_since_last = (long)(cur_time_mon -
2316 rdev->last_read_error) / 3600;
2317
2318 rdev->last_read_error = cur_time_mon;
2319
2320 /*
2321 * if hours_since_last is > the number of bits in read_errors
2322 * just set read errors to 0. We do this to avoid
2323 * overflowing the shift of read_errors by hours_since_last.
2324 */
2325 if (hours_since_last >= 8 * sizeof(read_errors))
2326 atomic_set(&rdev->read_errors, 0);
2327 else
2328 atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
2329}
2330
2331static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector,
2332 int sectors, struct page *page, int rw)
2333{
2334 sector_t first_bad;
2335 int bad_sectors;
2336
2337 if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors)
2338 && (rw == READ || test_bit(WriteErrorSeen, &rdev->flags)))
2339 return -1;
2340 if (sync_page_io(rdev, sector, sectors << 9, page, rw, 0, false))
2341 /* success */
2342 return 1;
2343 if (rw == WRITE) {
2344 set_bit(WriteErrorSeen, &rdev->flags);
2345 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2346 set_bit(MD_RECOVERY_NEEDED,
2347 &rdev->mddev->recovery);
2348 }
2349 /* need to record an error - either for the block or the device */
2350 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
2351 md_error(rdev->mddev, rdev);
2352 return 0;
2353}
2354
2355/*
2356 * This is a kernel thread which:
2357 *
2358 * 1. Retries failed read operations on working mirrors.
2359 * 2. Updates the raid superblock when problems encounter.
2360 * 3. Performs writes following reads for array synchronising.
2361 */
2362
2363static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10bio *r10_bio)
2364{
2365 int sect = 0; /* Offset from r10_bio->sector */
2366 int sectors = r10_bio->sectors;
2367 struct md_rdev*rdev;
2368 int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
2369 int d = r10_bio->devs[r10_bio->read_slot].devnum;
2370
2371 /* still own a reference to this rdev, so it cannot
2372 * have been cleared recently.
2373 */
2374 rdev = conf->mirrors[d].rdev;
2375
2376 if (test_bit(Faulty, &rdev->flags))
2377 /* drive has already been failed, just ignore any
2378 more fix_read_error() attempts */
2379 return;
2380
2381 check_decay_read_errors(mddev, rdev);
2382 atomic_inc(&rdev->read_errors);
2383 if (atomic_read(&rdev->read_errors) > max_read_errors) {
2384 char b[BDEVNAME_SIZE];
2385 bdevname(rdev->bdev, b);
2386
2387 pr_notice("md/raid10:%s: %s: Raid device exceeded read_error threshold [cur %d:max %d]\n",
2388 mdname(mddev), b,
2389 atomic_read(&rdev->read_errors), max_read_errors);
2390 pr_notice("md/raid10:%s: %s: Failing raid device\n",
2391 mdname(mddev), b);
2392 md_error(mddev, rdev);
2393 r10_bio->devs[r10_bio->read_slot].bio = IO_BLOCKED;
2394 return;
2395 }
2396
2397 while(sectors) {
2398 int s = sectors;
2399 int sl = r10_bio->read_slot;
2400 int success = 0;
2401 int start;
2402
2403 if (s > (PAGE_SIZE>>9))
2404 s = PAGE_SIZE >> 9;
2405
2406 rcu_read_lock();
2407 do {
2408 sector_t first_bad;
2409 int bad_sectors;
2410
2411 d = r10_bio->devs[sl].devnum;
2412 rdev = rcu_dereference(conf->mirrors[d].rdev);
2413 if (rdev &&
2414 test_bit(In_sync, &rdev->flags) &&
2415 !test_bit(Faulty, &rdev->flags) &&
2416 is_badblock(rdev, r10_bio->devs[sl].addr + sect, s,
2417 &first_bad, &bad_sectors) == 0) {
2418 atomic_inc(&rdev->nr_pending);
2419 rcu_read_unlock();
2420 success = sync_page_io(rdev,
2421 r10_bio->devs[sl].addr +
2422 sect,
2423 s<<9,
2424 conf->tmppage,
2425 REQ_OP_READ, 0, false);
2426 rdev_dec_pending(rdev, mddev);
2427 rcu_read_lock();
2428 if (success)
2429 break;
2430 }
2431 sl++;
2432 if (sl == conf->copies)
2433 sl = 0;
2434 } while (!success && sl != r10_bio->read_slot);
2435 rcu_read_unlock();
2436
2437 if (!success) {
2438 /* Cannot read from anywhere, just mark the block
2439 * as bad on the first device to discourage future
2440 * reads.
2441 */
2442 int dn = r10_bio->devs[r10_bio->read_slot].devnum;
2443 rdev = conf->mirrors[dn].rdev;
2444
2445 if (!rdev_set_badblocks(
2446 rdev,
2447 r10_bio->devs[r10_bio->read_slot].addr
2448 + sect,
2449 s, 0)) {
2450 md_error(mddev, rdev);
2451 r10_bio->devs[r10_bio->read_slot].bio
2452 = IO_BLOCKED;
2453 }
2454 break;
2455 }
2456
2457 start = sl;
2458 /* write it back and re-read */
2459 rcu_read_lock();
2460 while (sl != r10_bio->read_slot) {
2461 char b[BDEVNAME_SIZE];
2462
2463 if (sl==0)
2464 sl = conf->copies;
2465 sl--;
2466 d = r10_bio->devs[sl].devnum;
2467 rdev = rcu_dereference(conf->mirrors[d].rdev);
2468 if (!rdev ||
2469 test_bit(Faulty, &rdev->flags) ||
2470 !test_bit(In_sync, &rdev->flags))
2471 continue;
2472
2473 atomic_inc(&rdev->nr_pending);
2474 rcu_read_unlock();
2475 if (r10_sync_page_io(rdev,
2476 r10_bio->devs[sl].addr +
2477 sect,
2478 s, conf->tmppage, WRITE)
2479 == 0) {
2480 /* Well, this device is dead */
2481 pr_notice("md/raid10:%s: read correction write failed (%d sectors at %llu on %s)\n",
2482 mdname(mddev), s,
2483 (unsigned long long)(
2484 sect +
2485 choose_data_offset(r10_bio,
2486 rdev)),
2487 bdevname(rdev->bdev, b));
2488 pr_notice("md/raid10:%s: %s: failing drive\n",
2489 mdname(mddev),
2490 bdevname(rdev->bdev, b));
2491 }
2492 rdev_dec_pending(rdev, mddev);
2493 rcu_read_lock();
2494 }
2495 sl = start;
2496 while (sl != r10_bio->read_slot) {
2497 char b[BDEVNAME_SIZE];
2498
2499 if (sl==0)
2500 sl = conf->copies;
2501 sl--;
2502 d = r10_bio->devs[sl].devnum;
2503 rdev = rcu_dereference(conf->mirrors[d].rdev);
2504 if (!rdev ||
2505 test_bit(Faulty, &rdev->flags) ||
2506 !test_bit(In_sync, &rdev->flags))
2507 continue;
2508
2509 atomic_inc(&rdev->nr_pending);
2510 rcu_read_unlock();
2511 switch (r10_sync_page_io(rdev,
2512 r10_bio->devs[sl].addr +
2513 sect,
2514 s, conf->tmppage,
2515 READ)) {
2516 case 0:
2517 /* Well, this device is dead */
2518 pr_notice("md/raid10:%s: unable to read back corrected sectors (%d sectors at %llu on %s)\n",
2519 mdname(mddev), s,
2520 (unsigned long long)(
2521 sect +
2522 choose_data_offset(r10_bio, rdev)),
2523 bdevname(rdev->bdev, b));
2524 pr_notice("md/raid10:%s: %s: failing drive\n",
2525 mdname(mddev),
2526 bdevname(rdev->bdev, b));
2527 break;
2528 case 1:
2529 pr_info("md/raid10:%s: read error corrected (%d sectors at %llu on %s)\n",
2530 mdname(mddev), s,
2531 (unsigned long long)(
2532 sect +
2533 choose_data_offset(r10_bio, rdev)),
2534 bdevname(rdev->bdev, b));
2535 atomic_add(s, &rdev->corrected_errors);
2536 }
2537
2538 rdev_dec_pending(rdev, mddev);
2539 rcu_read_lock();
2540 }
2541 rcu_read_unlock();
2542
2543 sectors -= s;
2544 sect += s;
2545 }
2546}
2547
2548static int narrow_write_error(struct r10bio *r10_bio, int i)
2549{
2550 struct bio *bio = r10_bio->master_bio;
2551 struct mddev *mddev = r10_bio->mddev;
2552 struct r10conf *conf = mddev->private;
2553 struct md_rdev *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev;
2554 /* bio has the data to be written to slot 'i' where
2555 * we just recently had a write error.
2556 * We repeatedly clone the bio and trim down to one block,
2557 * then try the write. Where the write fails we record
2558 * a bad block.
2559 * It is conceivable that the bio doesn't exactly align with
2560 * blocks. We must handle this.
2561 *
2562 * We currently own a reference to the rdev.
2563 */
2564
2565 int block_sectors;
2566 sector_t sector;
2567 int sectors;
2568 int sect_to_write = r10_bio->sectors;
2569 int ok = 1;
2570
2571 if (rdev->badblocks.shift < 0)
2572 return 0;
2573
2574 block_sectors = roundup(1 << rdev->badblocks.shift,
2575 bdev_logical_block_size(rdev->bdev) >> 9);
2576 sector = r10_bio->sector;
2577 sectors = ((r10_bio->sector + block_sectors)
2578 & ~(sector_t)(block_sectors - 1))
2579 - sector;
2580
2581 while (sect_to_write) {
2582 struct bio *wbio;
2583 sector_t wsector;
2584 if (sectors > sect_to_write)
2585 sectors = sect_to_write;
2586 /* Write at 'sector' for 'sectors' */
2587 wbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
2588 bio_trim(wbio, sector - bio->bi_iter.bi_sector, sectors);
2589 wsector = r10_bio->devs[i].addr + (sector - r10_bio->sector);
2590 wbio->bi_iter.bi_sector = wsector +
2591 choose_data_offset(r10_bio, rdev);
2592 wbio->bi_bdev = rdev->bdev;
2593 bio_set_op_attrs(wbio, REQ_OP_WRITE, 0);
2594
2595 if (submit_bio_wait(wbio) < 0)
2596 /* Failure! */
2597 ok = rdev_set_badblocks(rdev, wsector,
2598 sectors, 0)
2599 && ok;
2600
2601 bio_put(wbio);
2602 sect_to_write -= sectors;
2603 sector += sectors;
2604 sectors = block_sectors;
2605 }
2606 return ok;
2607}
2608
2609static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
2610{
2611 int slot = r10_bio->read_slot;
2612 struct bio *bio;
2613 struct r10conf *conf = mddev->private;
2614 struct md_rdev *rdev = r10_bio->devs[slot].rdev;
2615 char b[BDEVNAME_SIZE];
2616 unsigned long do_sync;
2617 int max_sectors;
2618 dev_t bio_dev;
2619 sector_t bio_last_sector;
2620
2621 /* we got a read error. Maybe the drive is bad. Maybe just
2622 * the block and we can fix it.
2623 * We freeze all other IO, and try reading the block from
2624 * other devices. When we find one, we re-write
2625 * and check it that fixes the read error.
2626 * This is all done synchronously while the array is
2627 * frozen.
2628 */
2629 bio = r10_bio->devs[slot].bio;
2630 bdevname(bio->bi_bdev, b);
2631 bio_dev = bio->bi_bdev->bd_dev;
2632 bio_last_sector = r10_bio->devs[slot].addr + rdev->data_offset + r10_bio->sectors;
2633 bio_put(bio);
2634 r10_bio->devs[slot].bio = NULL;
2635
2636 if (mddev->ro)
2637 r10_bio->devs[slot].bio = IO_BLOCKED;
2638 else if (!test_bit(FailFast, &rdev->flags)) {
2639 freeze_array(conf, 1);
2640 fix_read_error(conf, mddev, r10_bio);
2641 unfreeze_array(conf);
2642 } else
2643 md_error(mddev, rdev);
2644
2645 rdev_dec_pending(rdev, mddev);
2646
2647read_more:
2648 rdev = read_balance(conf, r10_bio, &max_sectors);
2649 if (rdev == NULL) {
2650 pr_crit_ratelimited("md/raid10:%s: %s: unrecoverable I/O read error for block %llu\n",
2651 mdname(mddev), b,
2652 (unsigned long long)r10_bio->sector);
2653 raid_end_bio_io(r10_bio);
2654 return;
2655 }
2656
2657 do_sync = (r10_bio->master_bio->bi_opf & REQ_SYNC);
2658 slot = r10_bio->read_slot;
2659 pr_err_ratelimited("md/raid10:%s: %s: redirecting sector %llu to another mirror\n",
2660 mdname(mddev),
2661 bdevname(rdev->bdev, b),
2662 (unsigned long long)r10_bio->sector);
2663 bio = bio_clone_mddev(r10_bio->master_bio,
2664 GFP_NOIO, mddev);
2665 bio_trim(bio, r10_bio->sector - bio->bi_iter.bi_sector, max_sectors);
2666 r10_bio->devs[slot].bio = bio;
2667 r10_bio->devs[slot].rdev = rdev;
2668 bio->bi_iter.bi_sector = r10_bio->devs[slot].addr
2669 + choose_data_offset(r10_bio, rdev);
2670 bio->bi_bdev = rdev->bdev;
2671 bio_set_op_attrs(bio, REQ_OP_READ, do_sync);
2672 if (test_bit(FailFast, &rdev->flags) &&
2673 test_bit(R10BIO_FailFast, &r10_bio->state))
2674 bio->bi_opf |= MD_FAILFAST;
2675 bio->bi_private = r10_bio;
2676 bio->bi_end_io = raid10_end_read_request;
2677 trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
2678 bio, bio_dev,
2679 bio_last_sector - r10_bio->sectors);
2680
2681 if (max_sectors < r10_bio->sectors) {
2682 /* Drat - have to split this up more */
2683 struct bio *mbio = r10_bio->master_bio;
2684 int sectors_handled =
2685 r10_bio->sector + max_sectors
2686 - mbio->bi_iter.bi_sector;
2687 r10_bio->sectors = max_sectors;
2688 spin_lock_irq(&conf->device_lock);
2689 if (mbio->bi_phys_segments == 0)
2690 mbio->bi_phys_segments = 2;
2691 else
2692 mbio->bi_phys_segments++;
2693 spin_unlock_irq(&conf->device_lock);
2694 generic_make_request(bio);
2695
2696 r10_bio = mempool_alloc(conf->r10bio_pool,
2697 GFP_NOIO);
2698 r10_bio->master_bio = mbio;
2699 r10_bio->sectors = bio_sectors(mbio) - sectors_handled;
2700 r10_bio->state = 0;
2701 set_bit(R10BIO_ReadError,
2702 &r10_bio->state);
2703 r10_bio->mddev = mddev;
2704 r10_bio->sector = mbio->bi_iter.bi_sector
2705 + sectors_handled;
2706
2707 goto read_more;
2708 } else
2709 generic_make_request(bio);
2710}
2711
2712static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
2713{
2714 /* Some sort of write request has finished and it
2715 * succeeded in writing where we thought there was a
2716 * bad block. So forget the bad block.
2717 * Or possibly if failed and we need to record
2718 * a bad block.
2719 */
2720 int m;
2721 struct md_rdev *rdev;
2722
2723 if (test_bit(R10BIO_IsSync, &r10_bio->state) ||
2724 test_bit(R10BIO_IsRecover, &r10_bio->state)) {
2725 for (m = 0; m < conf->copies; m++) {
2726 int dev = r10_bio->devs[m].devnum;
2727 rdev = conf->mirrors[dev].rdev;
2728 if (r10_bio->devs[m].bio == NULL)
2729 continue;
2730 if (!r10_bio->devs[m].bio->bi_error) {
2731 rdev_clear_badblocks(
2732 rdev,
2733 r10_bio->devs[m].addr,
2734 r10_bio->sectors, 0);
2735 } else {
2736 if (!rdev_set_badblocks(
2737 rdev,
2738 r10_bio->devs[m].addr,
2739 r10_bio->sectors, 0))
2740 md_error(conf->mddev, rdev);
2741 }
2742 rdev = conf->mirrors[dev].replacement;
2743 if (r10_bio->devs[m].repl_bio == NULL)
2744 continue;
2745
2746 if (!r10_bio->devs[m].repl_bio->bi_error) {
2747 rdev_clear_badblocks(
2748 rdev,
2749 r10_bio->devs[m].addr,
2750 r10_bio->sectors, 0);
2751 } else {
2752 if (!rdev_set_badblocks(
2753 rdev,
2754 r10_bio->devs[m].addr,
2755 r10_bio->sectors, 0))
2756 md_error(conf->mddev, rdev);
2757 }
2758 }
2759 put_buf(r10_bio);
2760 } else {
2761 bool fail = false;
2762 for (m = 0; m < conf->copies; m++) {
2763 int dev = r10_bio->devs[m].devnum;
2764 struct bio *bio = r10_bio->devs[m].bio;
2765 rdev = conf->mirrors[dev].rdev;
2766 if (bio == IO_MADE_GOOD) {
2767 rdev_clear_badblocks(
2768 rdev,
2769 r10_bio->devs[m].addr,
2770 r10_bio->sectors, 0);
2771 rdev_dec_pending(rdev, conf->mddev);
2772 } else if (bio != NULL && bio->bi_error) {
2773 fail = true;
2774 if (!narrow_write_error(r10_bio, m)) {
2775 md_error(conf->mddev, rdev);
2776 set_bit(R10BIO_Degraded,
2777 &r10_bio->state);
2778 }
2779 rdev_dec_pending(rdev, conf->mddev);
2780 }
2781 bio = r10_bio->devs[m].repl_bio;
2782 rdev = conf->mirrors[dev].replacement;
2783 if (rdev && bio == IO_MADE_GOOD) {
2784 rdev_clear_badblocks(
2785 rdev,
2786 r10_bio->devs[m].addr,
2787 r10_bio->sectors, 0);
2788 rdev_dec_pending(rdev, conf->mddev);
2789 }
2790 }
2791 if (fail) {
2792 spin_lock_irq(&conf->device_lock);
2793 list_add(&r10_bio->retry_list, &conf->bio_end_io_list);
2794 conf->nr_queued++;
2795 spin_unlock_irq(&conf->device_lock);
2796 md_wakeup_thread(conf->mddev->thread);
2797 } else {
2798 if (test_bit(R10BIO_WriteError,
2799 &r10_bio->state))
2800 close_write(r10_bio);
2801 raid_end_bio_io(r10_bio);
2802 }
2803 }
2804}
2805
2806static void raid10d(struct md_thread *thread)
2807{
2808 struct mddev *mddev = thread->mddev;
2809 struct r10bio *r10_bio;
2810 unsigned long flags;
2811 struct r10conf *conf = mddev->private;
2812 struct list_head *head = &conf->retry_list;
2813 struct blk_plug plug;
2814
2815 md_check_recovery(mddev);
2816
2817 if (!list_empty_careful(&conf->bio_end_io_list) &&
2818 !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2819 LIST_HEAD(tmp);
2820 spin_lock_irqsave(&conf->device_lock, flags);
2821 if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
2822 while (!list_empty(&conf->bio_end_io_list)) {
2823 list_move(conf->bio_end_io_list.prev, &tmp);
2824 conf->nr_queued--;
2825 }
2826 }
2827 spin_unlock_irqrestore(&conf->device_lock, flags);
2828 while (!list_empty(&tmp)) {
2829 r10_bio = list_first_entry(&tmp, struct r10bio,
2830 retry_list);
2831 list_del(&r10_bio->retry_list);
2832 if (mddev->degraded)
2833 set_bit(R10BIO_Degraded, &r10_bio->state);
2834
2835 if (test_bit(R10BIO_WriteError,
2836 &r10_bio->state))
2837 close_write(r10_bio);
2838 raid_end_bio_io(r10_bio);
2839 }
2840 }
2841
2842 blk_start_plug(&plug);
2843 for (;;) {
2844
2845 flush_pending_writes(conf);
2846
2847 spin_lock_irqsave(&conf->device_lock, flags);
2848 if (list_empty(head)) {
2849 spin_unlock_irqrestore(&conf->device_lock, flags);
2850 break;
2851 }
2852 r10_bio = list_entry(head->prev, struct r10bio, retry_list);
2853 list_del(head->prev);
2854 conf->nr_queued--;
2855 spin_unlock_irqrestore(&conf->device_lock, flags);
2856
2857 mddev = r10_bio->mddev;
2858 conf = mddev->private;
2859 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
2860 test_bit(R10BIO_WriteError, &r10_bio->state))
2861 handle_write_completed(conf, r10_bio);
2862 else if (test_bit(R10BIO_IsReshape, &r10_bio->state))
2863 reshape_request_write(mddev, r10_bio);
2864 else if (test_bit(R10BIO_IsSync, &r10_bio->state))
2865 sync_request_write(mddev, r10_bio);
2866 else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
2867 recovery_request_write(mddev, r10_bio);
2868 else if (test_bit(R10BIO_ReadError, &r10_bio->state))
2869 handle_read_error(mddev, r10_bio);
2870 else {
2871 /* just a partial read to be scheduled from a
2872 * separate context
2873 */
2874 int slot = r10_bio->read_slot;
2875 generic_make_request(r10_bio->devs[slot].bio);
2876 }
2877
2878 cond_resched();
2879 if (mddev->sb_flags & ~(1<<MD_SB_CHANGE_PENDING))
2880 md_check_recovery(mddev);
2881 }
2882 blk_finish_plug(&plug);
2883}
2884
2885static int init_resync(struct r10conf *conf)
2886{
2887 int buffs;
2888 int i;
2889
2890 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
2891 BUG_ON(conf->r10buf_pool);
2892 conf->have_replacement = 0;
2893 for (i = 0; i < conf->geo.raid_disks; i++)
2894 if (conf->mirrors[i].replacement)
2895 conf->have_replacement = 1;
2896 conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
2897 if (!conf->r10buf_pool)
2898 return -ENOMEM;
2899 conf->next_resync = 0;
2900 return 0;
2901}
2902
2903/*
2904 * perform a "sync" on one "block"
2905 *
2906 * We need to make sure that no normal I/O request - particularly write
2907 * requests - conflict with active sync requests.
2908 *
2909 * This is achieved by tracking pending requests and a 'barrier' concept
2910 * that can be installed to exclude normal IO requests.
2911 *
2912 * Resync and recovery are handled very differently.
2913 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
2914 *
2915 * For resync, we iterate over virtual addresses, read all copies,
2916 * and update if there are differences. If only one copy is live,
2917 * skip it.
2918 * For recovery, we iterate over physical addresses, read a good
2919 * value for each non-in_sync drive, and over-write.
2920 *
2921 * So, for recovery we may have several outstanding complex requests for a
2922 * given address, one for each out-of-sync device. We model this by allocating
2923 * a number of r10_bio structures, one for each out-of-sync device.
2924 * As we setup these structures, we collect all bio's together into a list
2925 * which we then process collectively to add pages, and then process again
2926 * to pass to generic_make_request.
2927 *
2928 * The r10_bio structures are linked using a borrowed master_bio pointer.
2929 * This link is counted in ->remaining. When the r10_bio that points to NULL
2930 * has its remaining count decremented to 0, the whole complex operation
2931 * is complete.
2932 *
2933 */
2934
2935static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr,
2936 int *skipped)
2937{
2938 struct r10conf *conf = mddev->private;
2939 struct r10bio *r10_bio;
2940 struct bio *biolist = NULL, *bio;
2941 sector_t max_sector, nr_sectors;
2942 int i;
2943 int max_sync;
2944 sector_t sync_blocks;
2945 sector_t sectors_skipped = 0;
2946 int chunks_skipped = 0;
2947 sector_t chunk_mask = conf->geo.chunk_mask;
2948
2949 if (!conf->r10buf_pool)
2950 if (init_resync(conf))
2951 return 0;
2952
2953 /*
2954 * Allow skipping a full rebuild for incremental assembly
2955 * of a clean array, like RAID1 does.
2956 */
2957 if (mddev->bitmap == NULL &&
2958 mddev->recovery_cp == MaxSector &&
2959 mddev->reshape_position == MaxSector &&
2960 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
2961 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
2962 !test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
2963 conf->fullsync == 0) {
2964 *skipped = 1;
2965 return mddev->dev_sectors - sector_nr;
2966 }
2967
2968 skipped:
2969 max_sector = mddev->dev_sectors;
2970 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
2971 test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
2972 max_sector = mddev->resync_max_sectors;
2973 if (sector_nr >= max_sector) {
2974 /* If we aborted, we need to abort the
2975 * sync on the 'current' bitmap chucks (there can
2976 * be several when recovering multiple devices).
2977 * as we may have started syncing it but not finished.
2978 * We can find the current address in
2979 * mddev->curr_resync, but for recovery,
2980 * we need to convert that to several
2981 * virtual addresses.
2982 */
2983 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
2984 end_reshape(conf);
2985 close_sync(conf);
2986 return 0;
2987 }
2988
2989 if (mddev->curr_resync < max_sector) { /* aborted */
2990 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
2991 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2992 &sync_blocks, 1);
2993 else for (i = 0; i < conf->geo.raid_disks; i++) {
2994 sector_t sect =
2995 raid10_find_virt(conf, mddev->curr_resync, i);
2996 bitmap_end_sync(mddev->bitmap, sect,
2997 &sync_blocks, 1);
2998 }
2999 } else {
3000 /* completed sync */
3001 if ((!mddev->bitmap || conf->fullsync)
3002 && conf->have_replacement
3003 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3004 /* Completed a full sync so the replacements
3005 * are now fully recovered.
3006 */
3007 rcu_read_lock();
3008 for (i = 0; i < conf->geo.raid_disks; i++) {
3009 struct md_rdev *rdev =
3010 rcu_dereference(conf->mirrors[i].replacement);
3011 if (rdev)
3012 rdev->recovery_offset = MaxSector;
3013 }
3014 rcu_read_unlock();
3015 }
3016 conf->fullsync = 0;
3017 }
3018 bitmap_close_sync(mddev->bitmap);
3019 close_sync(conf);
3020 *skipped = 1;
3021 return sectors_skipped;
3022 }
3023
3024 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3025 return reshape_request(mddev, sector_nr, skipped);
3026
3027 if (chunks_skipped >= conf->geo.raid_disks) {
3028 /* if there has been nothing to do on any drive,
3029 * then there is nothing to do at all..
3030 */
3031 *skipped = 1;
3032 return (max_sector - sector_nr) + sectors_skipped;
3033 }
3034
3035 if (max_sector > mddev->resync_max)
3036 max_sector = mddev->resync_max; /* Don't do IO beyond here */
3037
3038 /* make sure whole request will fit in a chunk - if chunks
3039 * are meaningful
3040 */
3041 if (conf->geo.near_copies < conf->geo.raid_disks &&
3042 max_sector > (sector_nr | chunk_mask))
3043 max_sector = (sector_nr | chunk_mask) + 1;
3044
3045 /*
3046 * If there is non-resync activity waiting for a turn, then let it
3047 * though before starting on this new sync request.
3048 */
3049 if (conf->nr_waiting)
3050 schedule_timeout_uninterruptible(1);
3051
3052 /* Again, very different code for resync and recovery.
3053 * Both must result in an r10bio with a list of bios that
3054 * have bi_end_io, bi_sector, bi_bdev set,
3055 * and bi_private set to the r10bio.
3056 * For recovery, we may actually create several r10bios
3057 * with 2 bios in each, that correspond to the bios in the main one.
3058 * In this case, the subordinate r10bios link back through a
3059 * borrowed master_bio pointer, and the counter in the master
3060 * includes a ref from each subordinate.
3061 */
3062 /* First, we decide what to do and set ->bi_end_io
3063 * To end_sync_read if we want to read, and
3064 * end_sync_write if we will want to write.
3065 */
3066
3067 max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
3068 if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3069 /* recovery... the complicated one */
3070 int j;
3071 r10_bio = NULL;
3072
3073 for (i = 0 ; i < conf->geo.raid_disks; i++) {
3074 int still_degraded;
3075 struct r10bio *rb2;
3076 sector_t sect;
3077 int must_sync;
3078 int any_working;
3079 struct raid10_info *mirror = &conf->mirrors[i];
3080 struct md_rdev *mrdev, *mreplace;
3081
3082 rcu_read_lock();
3083 mrdev = rcu_dereference(mirror->rdev);
3084 mreplace = rcu_dereference(mirror->replacement);
3085
3086 if ((mrdev == NULL ||
3087 test_bit(Faulty, &mrdev->flags) ||
3088 test_bit(In_sync, &mrdev->flags)) &&
3089 (mreplace == NULL ||
3090 test_bit(Faulty, &mreplace->flags))) {
3091 rcu_read_unlock();
3092 continue;
3093 }
3094
3095 still_degraded = 0;
3096 /* want to reconstruct this device */
3097 rb2 = r10_bio;
3098 sect = raid10_find_virt(conf, sector_nr, i);
3099 if (sect >= mddev->resync_max_sectors) {
3100 /* last stripe is not complete - don't
3101 * try to recover this sector.
3102 */
3103 rcu_read_unlock();
3104 continue;
3105 }
3106 if (mreplace && test_bit(Faulty, &mreplace->flags))
3107 mreplace = NULL;
3108 /* Unless we are doing a full sync, or a replacement
3109 * we only need to recover the block if it is set in
3110 * the bitmap
3111 */
3112 must_sync = bitmap_start_sync(mddev->bitmap, sect,
3113 &sync_blocks, 1);
3114 if (sync_blocks < max_sync)
3115 max_sync = sync_blocks;
3116 if (!must_sync &&
3117 mreplace == NULL &&
3118 !conf->fullsync) {
3119 /* yep, skip the sync_blocks here, but don't assume
3120 * that there will never be anything to do here
3121 */
3122 chunks_skipped = -1;
3123 rcu_read_unlock();
3124 continue;
3125 }
3126 atomic_inc(&mrdev->nr_pending);
3127 if (mreplace)
3128 atomic_inc(&mreplace->nr_pending);
3129 rcu_read_unlock();
3130
3131 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
3132 r10_bio->state = 0;
3133 raise_barrier(conf, rb2 != NULL);
3134 atomic_set(&r10_bio->remaining, 0);
3135
3136 r10_bio->master_bio = (struct bio*)rb2;
3137 if (rb2)
3138 atomic_inc(&rb2->remaining);
3139 r10_bio->mddev = mddev;
3140 set_bit(R10BIO_IsRecover, &r10_bio->state);
3141 r10_bio->sector = sect;
3142
3143 raid10_find_phys(conf, r10_bio);
3144
3145 /* Need to check if the array will still be
3146 * degraded
3147 */
3148 rcu_read_lock();
3149 for (j = 0; j < conf->geo.raid_disks; j++) {
3150 struct md_rdev *rdev = rcu_dereference(
3151 conf->mirrors[j].rdev);
3152 if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
3153 still_degraded = 1;
3154 break;
3155 }
3156 }
3157
3158 must_sync = bitmap_start_sync(mddev->bitmap, sect,
3159 &sync_blocks, still_degraded);
3160
3161 any_working = 0;
3162 for (j=0; j<conf->copies;j++) {
3163 int k;
3164 int d = r10_bio->devs[j].devnum;
3165 sector_t from_addr, to_addr;
3166 struct md_rdev *rdev =
3167 rcu_dereference(conf->mirrors[d].rdev);
3168 sector_t sector, first_bad;
3169 int bad_sectors;
3170 if (!rdev ||
3171 !test_bit(In_sync, &rdev->flags))
3172 continue;
3173 /* This is where we read from */
3174 any_working = 1;
3175 sector = r10_bio->devs[j].addr;
3176
3177 if (is_badblock(rdev, sector, max_sync,
3178 &first_bad, &bad_sectors)) {
3179 if (first_bad > sector)
3180 max_sync = first_bad - sector;
3181 else {
3182 bad_sectors -= (sector
3183 - first_bad);
3184 if (max_sync > bad_sectors)
3185 max_sync = bad_sectors;
3186 continue;
3187 }
3188 }
3189 bio = r10_bio->devs[0].bio;
3190 bio_reset(bio);
3191 bio->bi_next = biolist;
3192 biolist = bio;
3193 bio->bi_private = r10_bio;
3194 bio->bi_end_io = end_sync_read;
3195 bio_set_op_attrs(bio, REQ_OP_READ, 0);
3196 if (test_bit(FailFast, &rdev->flags))
3197 bio->bi_opf |= MD_FAILFAST;
3198 from_addr = r10_bio->devs[j].addr;
3199 bio->bi_iter.bi_sector = from_addr +
3200 rdev->data_offset;
3201 bio->bi_bdev = rdev->bdev;
3202 atomic_inc(&rdev->nr_pending);
3203 /* and we write to 'i' (if not in_sync) */
3204
3205 for (k=0; k<conf->copies; k++)
3206 if (r10_bio->devs[k].devnum == i)
3207 break;
3208 BUG_ON(k == conf->copies);
3209 to_addr = r10_bio->devs[k].addr;
3210 r10_bio->devs[0].devnum = d;
3211 r10_bio->devs[0].addr = from_addr;
3212 r10_bio->devs[1].devnum = i;
3213 r10_bio->devs[1].addr = to_addr;
3214
3215 if (!test_bit(In_sync, &mrdev->flags)) {
3216 bio = r10_bio->devs[1].bio;
3217 bio_reset(bio);
3218 bio->bi_next = biolist;
3219 biolist = bio;
3220 bio->bi_private = r10_bio;
3221 bio->bi_end_io = end_sync_write;
3222 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
3223 bio->bi_iter.bi_sector = to_addr
3224 + mrdev->data_offset;
3225 bio->bi_bdev = mrdev->bdev;
3226 atomic_inc(&r10_bio->remaining);
3227 } else
3228 r10_bio->devs[1].bio->bi_end_io = NULL;
3229
3230 /* and maybe write to replacement */
3231 bio = r10_bio->devs[1].repl_bio;
3232 if (bio)
3233 bio->bi_end_io = NULL;
3234 /* Note: if mreplace != NULL, then bio
3235 * cannot be NULL as r10buf_pool_alloc will
3236 * have allocated it.
3237 * So the second test here is pointless.
3238 * But it keeps semantic-checkers happy, and
3239 * this comment keeps human reviewers
3240 * happy.
3241 */
3242 if (mreplace == NULL || bio == NULL ||
3243 test_bit(Faulty, &mreplace->flags))
3244 break;
3245 bio_reset(bio);
3246 bio->bi_next = biolist;
3247 biolist = bio;
3248 bio->bi_private = r10_bio;
3249 bio->bi_end_io = end_sync_write;
3250 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
3251 bio->bi_iter.bi_sector = to_addr +
3252 mreplace->data_offset;
3253 bio->bi_bdev = mreplace->bdev;
3254 atomic_inc(&r10_bio->remaining);
3255 break;
3256 }
3257 rcu_read_unlock();
3258 if (j == conf->copies) {
3259 /* Cannot recover, so abort the recovery or
3260 * record a bad block */
3261 if (any_working) {
3262 /* problem is that there are bad blocks
3263 * on other device(s)
3264 */
3265 int k;
3266 for (k = 0; k < conf->copies; k++)
3267 if (r10_bio->devs[k].devnum == i)
3268 break;
3269 if (!test_bit(In_sync,
3270 &mrdev->flags)
3271 && !rdev_set_badblocks(
3272 mrdev,
3273 r10_bio->devs[k].addr,
3274 max_sync, 0))
3275 any_working = 0;
3276 if (mreplace &&
3277 !rdev_set_badblocks(
3278 mreplace,
3279 r10_bio->devs[k].addr,
3280 max_sync, 0))
3281 any_working = 0;
3282 }
3283 if (!any_working) {
3284 if (!test_and_set_bit(MD_RECOVERY_INTR,
3285 &mddev->recovery))
3286 pr_warn("md/raid10:%s: insufficient working devices for recovery.\n",
3287 mdname(mddev));
3288 mirror->recovery_disabled
3289 = mddev->recovery_disabled;
3290 }
3291 put_buf(r10_bio);
3292 if (rb2)
3293 atomic_dec(&rb2->remaining);
3294 r10_bio = rb2;
3295 rdev_dec_pending(mrdev, mddev);
3296 if (mreplace)
3297 rdev_dec_pending(mreplace, mddev);
3298 break;
3299 }
3300 rdev_dec_pending(mrdev, mddev);
3301 if (mreplace)
3302 rdev_dec_pending(mreplace, mddev);
3303 if (r10_bio->devs[0].bio->bi_opf & MD_FAILFAST) {
3304 /* Only want this if there is elsewhere to
3305 * read from. 'j' is currently the first
3306 * readable copy.
3307 */
3308 int targets = 1;
3309 for (; j < conf->copies; j++) {
3310 int d = r10_bio->devs[j].devnum;
3311 if (conf->mirrors[d].rdev &&
3312 test_bit(In_sync,
3313 &conf->mirrors[d].rdev->flags))
3314 targets++;
3315 }
3316 if (targets == 1)
3317 r10_bio->devs[0].bio->bi_opf
3318 &= ~MD_FAILFAST;
3319 }
3320 }
3321 if (biolist == NULL) {
3322 while (r10_bio) {
3323 struct r10bio *rb2 = r10_bio;
3324 r10_bio = (struct r10bio*) rb2->master_bio;
3325 rb2->master_bio = NULL;
3326 put_buf(rb2);
3327 }
3328 goto giveup;
3329 }
3330 } else {
3331 /* resync. Schedule a read for every block at this virt offset */
3332 int count = 0;
3333
3334 bitmap_cond_end_sync(mddev->bitmap, sector_nr, 0);
3335
3336 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
3337 &sync_blocks, mddev->degraded) &&
3338 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED,
3339 &mddev->recovery)) {
3340 /* We can skip this block */
3341 *skipped = 1;
3342 return sync_blocks + sectors_skipped;
3343 }
3344 if (sync_blocks < max_sync)
3345 max_sync = sync_blocks;
3346 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
3347 r10_bio->state = 0;
3348
3349 r10_bio->mddev = mddev;
3350 atomic_set(&r10_bio->remaining, 0);
3351 raise_barrier(conf, 0);
3352 conf->next_resync = sector_nr;
3353
3354 r10_bio->master_bio = NULL;
3355 r10_bio->sector = sector_nr;
3356 set_bit(R10BIO_IsSync, &r10_bio->state);
3357 raid10_find_phys(conf, r10_bio);
3358 r10_bio->sectors = (sector_nr | chunk_mask) - sector_nr + 1;
3359
3360 for (i = 0; i < conf->copies; i++) {
3361 int d = r10_bio->devs[i].devnum;
3362 sector_t first_bad, sector;
3363 int bad_sectors;
3364 struct md_rdev *rdev;
3365
3366 if (r10_bio->devs[i].repl_bio)
3367 r10_bio->devs[i].repl_bio->bi_end_io = NULL;
3368
3369 bio = r10_bio->devs[i].bio;
3370 bio_reset(bio);
3371 bio->bi_error = -EIO;
3372 rcu_read_lock();
3373 rdev = rcu_dereference(conf->mirrors[d].rdev);
3374 if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
3375 rcu_read_unlock();
3376 continue;
3377 }
3378 sector = r10_bio->devs[i].addr;
3379 if (is_badblock(rdev, sector, max_sync,
3380 &first_bad, &bad_sectors)) {
3381 if (first_bad > sector)
3382 max_sync = first_bad - sector;
3383 else {
3384 bad_sectors -= (sector - first_bad);
3385 if (max_sync > bad_sectors)
3386 max_sync = bad_sectors;
3387 rcu_read_unlock();
3388 continue;
3389 }
3390 }
3391 atomic_inc(&rdev->nr_pending);
3392 atomic_inc(&r10_bio->remaining);
3393 bio->bi_next = biolist;
3394 biolist = bio;
3395 bio->bi_private = r10_bio;
3396 bio->bi_end_io = end_sync_read;
3397 bio_set_op_attrs(bio, REQ_OP_READ, 0);
3398 if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
3399 bio->bi_opf |= MD_FAILFAST;
3400 bio->bi_iter.bi_sector = sector + rdev->data_offset;
3401 bio->bi_bdev = rdev->bdev;
3402 count++;
3403
3404 rdev = rcu_dereference(conf->mirrors[d].replacement);
3405 if (rdev == NULL || test_bit(Faulty, &rdev->flags)) {
3406 rcu_read_unlock();
3407 continue;
3408 }
3409 atomic_inc(&rdev->nr_pending);
3410 rcu_read_unlock();
3411
3412 /* Need to set up for writing to the replacement */
3413 bio = r10_bio->devs[i].repl_bio;
3414 bio_reset(bio);
3415 bio->bi_error = -EIO;
3416
3417 sector = r10_bio->devs[i].addr;
3418 bio->bi_next = biolist;
3419 biolist = bio;
3420 bio->bi_private = r10_bio;
3421 bio->bi_end_io = end_sync_write;
3422 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
3423 if (test_bit(FailFast, &conf->mirrors[d].rdev->flags))
3424 bio->bi_opf |= MD_FAILFAST;
3425 bio->bi_iter.bi_sector = sector + rdev->data_offset;
3426 bio->bi_bdev = rdev->bdev;
3427 count++;
3428 }
3429
3430 if (count < 2) {
3431 for (i=0; i<conf->copies; i++) {
3432 int d = r10_bio->devs[i].devnum;
3433 if (r10_bio->devs[i].bio->bi_end_io)
3434 rdev_dec_pending(conf->mirrors[d].rdev,
3435 mddev);
3436 if (r10_bio->devs[i].repl_bio &&
3437 r10_bio->devs[i].repl_bio->bi_end_io)
3438 rdev_dec_pending(
3439 conf->mirrors[d].replacement,
3440 mddev);
3441 }
3442 put_buf(r10_bio);
3443 biolist = NULL;
3444 goto giveup;
3445 }
3446 }
3447
3448 nr_sectors = 0;
3449 if (sector_nr + max_sync < max_sector)
3450 max_sector = sector_nr + max_sync;
3451 do {
3452 struct page *page;
3453 int len = PAGE_SIZE;
3454 if (sector_nr + (len>>9) > max_sector)
3455 len = (max_sector - sector_nr) << 9;
3456 if (len == 0)
3457 break;
3458 for (bio= biolist ; bio ; bio=bio->bi_next) {
3459 struct bio *bio2;
3460 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
3461 if (bio_add_page(bio, page, len, 0))
3462 continue;
3463
3464 /* stop here */
3465 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
3466 for (bio2 = biolist;
3467 bio2 && bio2 != bio;
3468 bio2 = bio2->bi_next) {
3469 /* remove last page from this bio */
3470 bio2->bi_vcnt--;
3471 bio2->bi_iter.bi_size -= len;
3472 bio_clear_flag(bio2, BIO_SEG_VALID);
3473 }
3474 goto bio_full;
3475 }
3476 nr_sectors += len>>9;
3477 sector_nr += len>>9;
3478 } while (biolist->bi_vcnt < RESYNC_PAGES);
3479 bio_full:
3480 r10_bio->sectors = nr_sectors;
3481
3482 while (biolist) {
3483 bio = biolist;
3484 biolist = biolist->bi_next;
3485
3486 bio->bi_next = NULL;
3487 r10_bio = bio->bi_private;
3488 r10_bio->sectors = nr_sectors;
3489
3490 if (bio->bi_end_io == end_sync_read) {
3491 md_sync_acct(bio->bi_bdev, nr_sectors);
3492 bio->bi_error = 0;
3493 generic_make_request(bio);
3494 }
3495 }
3496
3497 if (sectors_skipped)
3498 /* pretend they weren't skipped, it makes
3499 * no important difference in this case
3500 */
3501 md_done_sync(mddev, sectors_skipped, 1);
3502
3503 return sectors_skipped + nr_sectors;
3504 giveup:
3505 /* There is nowhere to write, so all non-sync
3506 * drives must be failed or in resync, all drives
3507 * have a bad block, so try the next chunk...
3508 */
3509 if (sector_nr + max_sync < max_sector)
3510 max_sector = sector_nr + max_sync;
3511
3512 sectors_skipped += (max_sector - sector_nr);
3513 chunks_skipped ++;
3514 sector_nr = max_sector;
3515 goto skipped;
3516}
3517
3518static sector_t
3519raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks)
3520{
3521 sector_t size;
3522 struct r10conf *conf = mddev->private;
3523
3524 if (!raid_disks)
3525 raid_disks = min(conf->geo.raid_disks,
3526 conf->prev.raid_disks);
3527 if (!sectors)
3528 sectors = conf->dev_sectors;
3529
3530 size = sectors >> conf->geo.chunk_shift;
3531 sector_div(size, conf->geo.far_copies);
3532 size = size * raid_disks;
3533 sector_div(size, conf->geo.near_copies);
3534
3535 return size << conf->geo.chunk_shift;
3536}
3537
3538static void calc_sectors(struct r10conf *conf, sector_t size)
3539{
3540 /* Calculate the number of sectors-per-device that will
3541 * actually be used, and set conf->dev_sectors and
3542 * conf->stride
3543 */
3544
3545 size = size >> conf->geo.chunk_shift;
3546 sector_div(size, conf->geo.far_copies);
3547 size = size * conf->geo.raid_disks;
3548 sector_div(size, conf->geo.near_copies);
3549 /* 'size' is now the number of chunks in the array */
3550 /* calculate "used chunks per device" */
3551 size = size * conf->copies;
3552
3553 /* We need to round up when dividing by raid_disks to
3554 * get the stride size.
3555 */
3556 size = DIV_ROUND_UP_SECTOR_T(size, conf->geo.raid_disks);
3557
3558 conf->dev_sectors = size << conf->geo.chunk_shift;
3559
3560 if (conf->geo.far_offset)
3561 conf->geo.stride = 1 << conf->geo.chunk_shift;
3562 else {
3563 sector_div(size, conf->geo.far_copies);
3564 conf->geo.stride = size << conf->geo.chunk_shift;
3565 }
3566}
3567
3568enum geo_type {geo_new, geo_old, geo_start};
3569static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new)
3570{
3571 int nc, fc, fo;
3572 int layout, chunk, disks;
3573 switch (new) {
3574 case geo_old:
3575 layout = mddev->layout;
3576 chunk = mddev->chunk_sectors;
3577 disks = mddev->raid_disks - mddev->delta_disks;
3578 break;
3579 case geo_new:
3580 layout = mddev->new_layout;
3581 chunk = mddev->new_chunk_sectors;
3582 disks = mddev->raid_disks;
3583 break;
3584 default: /* avoid 'may be unused' warnings */
3585 case geo_start: /* new when starting reshape - raid_disks not
3586 * updated yet. */
3587 layout = mddev->new_layout;
3588 chunk = mddev->new_chunk_sectors;
3589 disks = mddev->raid_disks + mddev->delta_disks;
3590 break;
3591 }
3592 if (layout >> 19)
3593 return -1;
3594 if (chunk < (PAGE_SIZE >> 9) ||
3595 !is_power_of_2(chunk))
3596 return -2;
3597 nc = layout & 255;
3598 fc = (layout >> 8) & 255;
3599 fo = layout & (1<<16);
3600 geo->raid_disks = disks;
3601 geo->near_copies = nc;
3602 geo->far_copies = fc;
3603 geo->far_offset = fo;
3604 switch (layout >> 17) {
3605 case 0: /* original layout. simple but not always optimal */
3606 geo->far_set_size = disks;
3607 break;
3608 case 1: /* "improved" layout which was buggy. Hopefully no-one is
3609 * actually using this, but leave code here just in case.*/
3610 geo->far_set_size = disks/fc;
3611 WARN(geo->far_set_size < fc,
3612 "This RAID10 layout does not provide data safety - please backup and create new array\n");
3613 break;
3614 case 2: /* "improved" layout fixed to match documentation */
3615 geo->far_set_size = fc * nc;
3616 break;
3617 default: /* Not a valid layout */
3618 return -1;
3619 }
3620 geo->chunk_mask = chunk - 1;
3621 geo->chunk_shift = ffz(~chunk);
3622 return nc*fc;
3623}
3624
3625static struct r10conf *setup_conf(struct mddev *mddev)
3626{
3627 struct r10conf *conf = NULL;
3628 int err = -EINVAL;
3629 struct geom geo;
3630 int copies;
3631
3632 copies = setup_geo(&geo, mddev, geo_new);
3633
3634 if (copies == -2) {
3635 pr_warn("md/raid10:%s: chunk size must be at least PAGE_SIZE(%ld) and be a power of 2.\n",
3636 mdname(mddev), PAGE_SIZE);
3637 goto out;
3638 }
3639
3640 if (copies < 2 || copies > mddev->raid_disks) {
3641 pr_warn("md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
3642 mdname(mddev), mddev->new_layout);
3643 goto out;
3644 }
3645
3646 err = -ENOMEM;
3647 conf = kzalloc(sizeof(struct r10conf), GFP_KERNEL);
3648 if (!conf)
3649 goto out;
3650
3651 /* FIXME calc properly */
3652 conf->mirrors = kzalloc(sizeof(struct raid10_info)*(mddev->raid_disks +
3653 max(0,-mddev->delta_disks)),
3654 GFP_KERNEL);
3655 if (!conf->mirrors)
3656 goto out;
3657
3658 conf->tmppage = alloc_page(GFP_KERNEL);
3659 if (!conf->tmppage)
3660 goto out;
3661
3662 conf->geo = geo;
3663 conf->copies = copies;
3664 conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
3665 r10bio_pool_free, conf);
3666 if (!conf->r10bio_pool)
3667 goto out;
3668
3669 calc_sectors(conf, mddev->dev_sectors);
3670 if (mddev->reshape_position == MaxSector) {
3671 conf->prev = conf->geo;
3672 conf->reshape_progress = MaxSector;
3673 } else {
3674 if (setup_geo(&conf->prev, mddev, geo_old) != conf->copies) {
3675 err = -EINVAL;
3676 goto out;
3677 }
3678 conf->reshape_progress = mddev->reshape_position;
3679 if (conf->prev.far_offset)
3680 conf->prev.stride = 1 << conf->prev.chunk_shift;
3681 else
3682 /* far_copies must be 1 */
3683 conf->prev.stride = conf->dev_sectors;
3684 }
3685 conf->reshape_safe = conf->reshape_progress;
3686 spin_lock_init(&conf->device_lock);
3687 INIT_LIST_HEAD(&conf->retry_list);
3688 INIT_LIST_HEAD(&conf->bio_end_io_list);
3689
3690 spin_lock_init(&conf->resync_lock);
3691 init_waitqueue_head(&conf->wait_barrier);
3692 atomic_set(&conf->nr_pending, 0);
3693
3694 conf->thread = md_register_thread(raid10d, mddev, "raid10");
3695 if (!conf->thread)
3696 goto out;
3697
3698 conf->mddev = mddev;
3699 return conf;
3700
3701 out:
3702 if (conf) {
3703 mempool_destroy(conf->r10bio_pool);
3704 kfree(conf->mirrors);
3705 safe_put_page(conf->tmppage);
3706 kfree(conf);
3707 }
3708 return ERR_PTR(err);
3709}
3710
3711static int raid10_run(struct mddev *mddev)
3712{
3713 struct r10conf *conf;
3714 int i, disk_idx, chunk_size;
3715 struct raid10_info *disk;
3716 struct md_rdev *rdev;
3717 sector_t size;
3718 sector_t min_offset_diff = 0;
3719 int first = 1;
3720 bool discard_supported = false;
3721
3722 if (mddev->private == NULL) {
3723 conf = setup_conf(mddev);
3724 if (IS_ERR(conf))
3725 return PTR_ERR(conf);
3726 mddev->private = conf;
3727 }
3728 conf = mddev->private;
3729 if (!conf)
3730 goto out;
3731
3732 mddev->thread = conf->thread;
3733 conf->thread = NULL;
3734
3735 chunk_size = mddev->chunk_sectors << 9;
3736 if (mddev->queue) {
3737 blk_queue_max_discard_sectors(mddev->queue,
3738 mddev->chunk_sectors);
3739 blk_queue_max_write_same_sectors(mddev->queue, 0);
3740 blk_queue_io_min(mddev->queue, chunk_size);
3741 if (conf->geo.raid_disks % conf->geo.near_copies)
3742 blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);
3743 else
3744 blk_queue_io_opt(mddev->queue, chunk_size *
3745 (conf->geo.raid_disks / conf->geo.near_copies));
3746 }
3747
3748 rdev_for_each(rdev, mddev) {
3749 long long diff;
3750 struct request_queue *q;
3751
3752 disk_idx = rdev->raid_disk;
3753 if (disk_idx < 0)
3754 continue;
3755 if (disk_idx >= conf->geo.raid_disks &&
3756 disk_idx >= conf->prev.raid_disks)
3757 continue;
3758 disk = conf->mirrors + disk_idx;
3759
3760 if (test_bit(Replacement, &rdev->flags)) {
3761 if (disk->replacement)
3762 goto out_free_conf;
3763 disk->replacement = rdev;
3764 } else {
3765 if (disk->rdev)
3766 goto out_free_conf;
3767 disk->rdev = rdev;
3768 }
3769 q = bdev_get_queue(rdev->bdev);
3770 diff = (rdev->new_data_offset - rdev->data_offset);
3771 if (!mddev->reshape_backwards)
3772 diff = -diff;
3773 if (diff < 0)
3774 diff = 0;
3775 if (first || diff < min_offset_diff)
3776 min_offset_diff = diff;
3777
3778 if (mddev->gendisk)
3779 disk_stack_limits(mddev->gendisk, rdev->bdev,
3780 rdev->data_offset << 9);
3781
3782 disk->head_position = 0;
3783
3784 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
3785 discard_supported = true;
3786 }
3787
3788 if (mddev->queue) {
3789 if (discard_supported)
3790 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
3791 mddev->queue);
3792 else
3793 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
3794 mddev->queue);
3795 }
3796 /* need to check that every block has at least one working mirror */
3797 if (!enough(conf, -1)) {
3798 pr_err("md/raid10:%s: not enough operational mirrors.\n",
3799 mdname(mddev));
3800 goto out_free_conf;
3801 }
3802
3803 if (conf->reshape_progress != MaxSector) {
3804 /* must ensure that shape change is supported */
3805 if (conf->geo.far_copies != 1 &&
3806 conf->geo.far_offset == 0)
3807 goto out_free_conf;
3808 if (conf->prev.far_copies != 1 &&
3809 conf->prev.far_offset == 0)
3810 goto out_free_conf;
3811 }
3812
3813 mddev->degraded = 0;
3814 for (i = 0;
3815 i < conf->geo.raid_disks
3816 || i < conf->prev.raid_disks;
3817 i++) {
3818
3819 disk = conf->mirrors + i;
3820
3821 if (!disk->rdev && disk->replacement) {
3822 /* The replacement is all we have - use it */
3823 disk->rdev = disk->replacement;
3824 disk->replacement = NULL;
3825 clear_bit(Replacement, &disk->rdev->flags);
3826 }
3827
3828 if (!disk->rdev ||
3829 !test_bit(In_sync, &disk->rdev->flags)) {
3830 disk->head_position = 0;
3831 mddev->degraded++;
3832 if (disk->rdev &&
3833 disk->rdev->saved_raid_disk < 0)
3834 conf->fullsync = 1;
3835 }
3836 disk->recovery_disabled = mddev->recovery_disabled - 1;
3837 }
3838
3839 if (mddev->recovery_cp != MaxSector)
3840 pr_notice("md/raid10:%s: not clean -- starting background reconstruction\n",
3841 mdname(mddev));
3842 pr_info("md/raid10:%s: active with %d out of %d devices\n",
3843 mdname(mddev), conf->geo.raid_disks - mddev->degraded,
3844 conf->geo.raid_disks);
3845 /*
3846 * Ok, everything is just fine now
3847 */
3848 mddev->dev_sectors = conf->dev_sectors;
3849 size = raid10_size(mddev, 0, 0);
3850 md_set_array_sectors(mddev, size);
3851 mddev->resync_max_sectors = size;
3852 set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags);
3853
3854 if (mddev->queue) {
3855 int stripe = conf->geo.raid_disks *
3856 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
3857
3858 /* Calculate max read-ahead size.
3859 * We need to readahead at least twice a whole stripe....
3860 * maybe...
3861 */
3862 stripe /= conf->geo.near_copies;
3863 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
3864 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
3865 }
3866
3867 if (md_integrity_register(mddev))
3868 goto out_free_conf;
3869
3870 if (conf->reshape_progress != MaxSector) {
3871 unsigned long before_length, after_length;
3872
3873 before_length = ((1 << conf->prev.chunk_shift) *
3874 conf->prev.far_copies);
3875 after_length = ((1 << conf->geo.chunk_shift) *
3876 conf->geo.far_copies);
3877
3878 if (max(before_length, after_length) > min_offset_diff) {
3879 /* This cannot work */
3880 pr_warn("md/raid10: offset difference not enough to continue reshape\n");
3881 goto out_free_conf;
3882 }
3883 conf->offset_diff = min_offset_diff;
3884
3885 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3886 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3887 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
3888 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
3889 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
3890 "reshape");
3891 }
3892
3893 return 0;
3894
3895out_free_conf:
3896 md_unregister_thread(&mddev->thread);
3897 mempool_destroy(conf->r10bio_pool);
3898 safe_put_page(conf->tmppage);
3899 kfree(conf->mirrors);
3900 kfree(conf);
3901 mddev->private = NULL;
3902out:
3903 return -EIO;
3904}
3905
3906static void raid10_free(struct mddev *mddev, void *priv)
3907{
3908 struct r10conf *conf = priv;
3909
3910 mempool_destroy(conf->r10bio_pool);
3911 safe_put_page(conf->tmppage);
3912 kfree(conf->mirrors);
3913 kfree(conf->mirrors_old);
3914 kfree(conf->mirrors_new);
3915 kfree(conf);
3916}
3917
3918static void raid10_quiesce(struct mddev *mddev, int state)
3919{
3920 struct r10conf *conf = mddev->private;
3921
3922 switch(state) {
3923 case 1:
3924 raise_barrier(conf, 0);
3925 break;
3926 case 0:
3927 lower_barrier(conf);
3928 break;
3929 }
3930}
3931
3932static int raid10_resize(struct mddev *mddev, sector_t sectors)
3933{
3934 /* Resize of 'far' arrays is not supported.
3935 * For 'near' and 'offset' arrays we can set the
3936 * number of sectors used to be an appropriate multiple
3937 * of the chunk size.
3938 * For 'offset', this is far_copies*chunksize.
3939 * For 'near' the multiplier is the LCM of
3940 * near_copies and raid_disks.
3941 * So if far_copies > 1 && !far_offset, fail.
3942 * Else find LCM(raid_disks, near_copy)*far_copies and
3943 * multiply by chunk_size. Then round to this number.
3944 * This is mostly done by raid10_size()
3945 */
3946 struct r10conf *conf = mddev->private;
3947 sector_t oldsize, size;
3948
3949 if (mddev->reshape_position != MaxSector)
3950 return -EBUSY;
3951
3952 if (conf->geo.far_copies > 1 && !conf->geo.far_offset)
3953 return -EINVAL;
3954
3955 oldsize = raid10_size(mddev, 0, 0);
3956 size = raid10_size(mddev, sectors, 0);
3957 if (mddev->external_size &&
3958 mddev->array_sectors > size)
3959 return -EINVAL;
3960 if (mddev->bitmap) {
3961 int ret = bitmap_resize(mddev->bitmap, size, 0, 0);
3962 if (ret)
3963 return ret;
3964 }
3965 md_set_array_sectors(mddev, size);
3966 if (mddev->queue) {
3967 set_capacity(mddev->gendisk, mddev->array_sectors);
3968 revalidate_disk(mddev->gendisk);
3969 }
3970 if (sectors > mddev->dev_sectors &&
3971 mddev->recovery_cp > oldsize) {
3972 mddev->recovery_cp = oldsize;
3973 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3974 }
3975 calc_sectors(conf, sectors);
3976 mddev->dev_sectors = conf->dev_sectors;
3977 mddev->resync_max_sectors = size;
3978 return 0;
3979}
3980
3981static void *raid10_takeover_raid0(struct mddev *mddev, sector_t size, int devs)
3982{
3983 struct md_rdev *rdev;
3984 struct r10conf *conf;
3985
3986 if (mddev->degraded > 0) {
3987 pr_warn("md/raid10:%s: Error: degraded raid0!\n",
3988 mdname(mddev));
3989 return ERR_PTR(-EINVAL);
3990 }
3991 sector_div(size, devs);
3992
3993 /* Set new parameters */
3994 mddev->new_level = 10;
3995 /* new layout: far_copies = 1, near_copies = 2 */
3996 mddev->new_layout = (1<<8) + 2;
3997 mddev->new_chunk_sectors = mddev->chunk_sectors;
3998 mddev->delta_disks = mddev->raid_disks;
3999 mddev->raid_disks *= 2;
4000 /* make sure it will be not marked as dirty */
4001 mddev->recovery_cp = MaxSector;
4002 mddev->dev_sectors = size;
4003
4004 conf = setup_conf(mddev);
4005 if (!IS_ERR(conf)) {
4006 rdev_for_each(rdev, mddev)
4007 if (rdev->raid_disk >= 0) {
4008 rdev->new_raid_disk = rdev->raid_disk * 2;
4009 rdev->sectors = size;
4010 }
4011 conf->barrier = 1;
4012 }
4013
4014 return conf;
4015}
4016
4017static void *raid10_takeover(struct mddev *mddev)
4018{
4019 struct r0conf *raid0_conf;
4020
4021 /* raid10 can take over:
4022 * raid0 - providing it has only two drives
4023 */
4024 if (mddev->level == 0) {
4025 /* for raid0 takeover only one zone is supported */
4026 raid0_conf = mddev->private;
4027 if (raid0_conf->nr_strip_zones > 1) {
4028 pr_warn("md/raid10:%s: cannot takeover raid 0 with more than one zone.\n",
4029 mdname(mddev));
4030 return ERR_PTR(-EINVAL);
4031 }
4032 return raid10_takeover_raid0(mddev,
4033 raid0_conf->strip_zone->zone_end,
4034 raid0_conf->strip_zone->nb_dev);
4035 }
4036 return ERR_PTR(-EINVAL);
4037}
4038
4039static int raid10_check_reshape(struct mddev *mddev)
4040{
4041 /* Called when there is a request to change
4042 * - layout (to ->new_layout)
4043 * - chunk size (to ->new_chunk_sectors)
4044 * - raid_disks (by delta_disks)
4045 * or when trying to restart a reshape that was ongoing.
4046 *
4047 * We need to validate the request and possibly allocate
4048 * space if that might be an issue later.
4049 *
4050 * Currently we reject any reshape of a 'far' mode array,
4051 * allow chunk size to change if new is generally acceptable,
4052 * allow raid_disks to increase, and allow
4053 * a switch between 'near' mode and 'offset' mode.
4054 */
4055 struct r10conf *conf = mddev->private;
4056 struct geom geo;
4057
4058 if (conf->geo.far_copies != 1 && !conf->geo.far_offset)
4059 return -EINVAL;
4060
4061 if (setup_geo(&geo, mddev, geo_start) != conf->copies)
4062 /* mustn't change number of copies */
4063 return -EINVAL;
4064 if (geo.far_copies > 1 && !geo.far_offset)
4065 /* Cannot switch to 'far' mode */
4066 return -EINVAL;
4067
4068 if (mddev->array_sectors & geo.chunk_mask)
4069 /* not factor of array size */
4070 return -EINVAL;
4071
4072 if (!enough(conf, -1))
4073 return -EINVAL;
4074
4075 kfree(conf->mirrors_new);
4076 conf->mirrors_new = NULL;
4077 if (mddev->delta_disks > 0) {
4078 /* allocate new 'mirrors' list */
4079 conf->mirrors_new = kzalloc(
4080 sizeof(struct raid10_info)
4081 *(mddev->raid_disks +
4082 mddev->delta_disks),
4083 GFP_KERNEL);
4084 if (!conf->mirrors_new)
4085 return -ENOMEM;
4086 }
4087 return 0;
4088}
4089
4090/*
4091 * Need to check if array has failed when deciding whether to:
4092 * - start an array
4093 * - remove non-faulty devices
4094 * - add a spare
4095 * - allow a reshape
4096 * This determination is simple when no reshape is happening.
4097 * However if there is a reshape, we need to carefully check
4098 * both the before and after sections.
4099 * This is because some failed devices may only affect one
4100 * of the two sections, and some non-in_sync devices may
4101 * be insync in the section most affected by failed devices.
4102 */
4103static int calc_degraded(struct r10conf *conf)
4104{
4105 int degraded, degraded2;
4106 int i;
4107
4108 rcu_read_lock();
4109 degraded = 0;
4110 /* 'prev' section first */
4111 for (i = 0; i < conf->prev.raid_disks; i++) {
4112 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
4113 if (!rdev || test_bit(Faulty, &rdev->flags))
4114 degraded++;
4115 else if (!test_bit(In_sync, &rdev->flags))
4116 /* When we can reduce the number of devices in
4117 * an array, this might not contribute to
4118 * 'degraded'. It does now.
4119 */
4120 degraded++;
4121 }
4122 rcu_read_unlock();
4123 if (conf->geo.raid_disks == conf->prev.raid_disks)
4124 return degraded;
4125 rcu_read_lock();
4126 degraded2 = 0;
4127 for (i = 0; i < conf->geo.raid_disks; i++) {
4128 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
4129 if (!rdev || test_bit(Faulty, &rdev->flags))
4130 degraded2++;
4131 else if (!test_bit(In_sync, &rdev->flags)) {
4132 /* If reshape is increasing the number of devices,
4133 * this section has already been recovered, so
4134 * it doesn't contribute to degraded.
4135 * else it does.
4136 */
4137 if (conf->geo.raid_disks <= conf->prev.raid_disks)
4138 degraded2++;
4139 }
4140 }
4141 rcu_read_unlock();
4142 if (degraded2 > degraded)
4143 return degraded2;
4144 return degraded;
4145}
4146
4147static int raid10_start_reshape(struct mddev *mddev)
4148{
4149 /* A 'reshape' has been requested. This commits
4150 * the various 'new' fields and sets MD_RECOVER_RESHAPE
4151 * This also checks if there are enough spares and adds them
4152 * to the array.
4153 * We currently require enough spares to make the final
4154 * array non-degraded. We also require that the difference
4155 * between old and new data_offset - on each device - is
4156 * enough that we never risk over-writing.
4157 */
4158
4159 unsigned long before_length, after_length;
4160 sector_t min_offset_diff = 0;
4161 int first = 1;
4162 struct geom new;
4163 struct r10conf *conf = mddev->private;
4164 struct md_rdev *rdev;
4165 int spares = 0;
4166 int ret;
4167
4168 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4169 return -EBUSY;
4170
4171 if (setup_geo(&new, mddev, geo_start) != conf->copies)
4172 return -EINVAL;
4173
4174 before_length = ((1 << conf->prev.chunk_shift) *
4175 conf->prev.far_copies);
4176 after_length = ((1 << conf->geo.chunk_shift) *
4177 conf->geo.far_copies);
4178
4179 rdev_for_each(rdev, mddev) {
4180 if (!test_bit(In_sync, &rdev->flags)
4181 && !test_bit(Faulty, &rdev->flags))
4182 spares++;
4183 if (rdev->raid_disk >= 0) {
4184 long long diff = (rdev->new_data_offset
4185 - rdev->data_offset);
4186 if (!mddev->reshape_backwards)
4187 diff = -diff;
4188 if (diff < 0)
4189 diff = 0;
4190 if (first || diff < min_offset_diff)
4191 min_offset_diff = diff;
4192 }
4193 }
4194
4195 if (max(before_length, after_length) > min_offset_diff)
4196 return -EINVAL;
4197
4198 if (spares < mddev->delta_disks)
4199 return -EINVAL;
4200
4201 conf->offset_diff = min_offset_diff;
4202 spin_lock_irq(&conf->device_lock);
4203 if (conf->mirrors_new) {
4204 memcpy(conf->mirrors_new, conf->mirrors,
4205 sizeof(struct raid10_info)*conf->prev.raid_disks);
4206 smp_mb();
4207 kfree(conf->mirrors_old);
4208 conf->mirrors_old = conf->mirrors;
4209 conf->mirrors = conf->mirrors_new;
4210 conf->mirrors_new = NULL;
4211 }
4212 setup_geo(&conf->geo, mddev, geo_start);
4213 smp_mb();
4214 if (mddev->reshape_backwards) {
4215 sector_t size = raid10_size(mddev, 0, 0);
4216 if (size < mddev->array_sectors) {
4217 spin_unlock_irq(&conf->device_lock);
4218 pr_warn("md/raid10:%s: array size must be reduce before number of disks\n",
4219 mdname(mddev));
4220 return -EINVAL;
4221 }
4222 mddev->resync_max_sectors = size;
4223 conf->reshape_progress = size;
4224 } else
4225 conf->reshape_progress = 0;
4226 conf->reshape_safe = conf->reshape_progress;
4227 spin_unlock_irq(&conf->device_lock);
4228
4229 if (mddev->delta_disks && mddev->bitmap) {
4230 ret = bitmap_resize(mddev->bitmap,
4231 raid10_size(mddev, 0,
4232 conf->geo.raid_disks),
4233 0, 0);
4234 if (ret)
4235 goto abort;
4236 }
4237 if (mddev->delta_disks > 0) {
4238 rdev_for_each(rdev, mddev)
4239 if (rdev->raid_disk < 0 &&
4240 !test_bit(Faulty, &rdev->flags)) {
4241 if (raid10_add_disk(mddev, rdev) == 0) {
4242 if (rdev->raid_disk >=
4243 conf->prev.raid_disks)
4244 set_bit(In_sync, &rdev->flags);
4245 else
4246 rdev->recovery_offset = 0;
4247
4248 if (sysfs_link_rdev(mddev, rdev))
4249 /* Failure here is OK */;
4250 }
4251 } else if (rdev->raid_disk >= conf->prev.raid_disks
4252 && !test_bit(Faulty, &rdev->flags)) {
4253 /* This is a spare that was manually added */
4254 set_bit(In_sync, &rdev->flags);
4255 }
4256 }
4257 /* When a reshape changes the number of devices,
4258 * ->degraded is measured against the larger of the
4259 * pre and post numbers.
4260 */
4261 spin_lock_irq(&conf->device_lock);
4262 mddev->degraded = calc_degraded(conf);
4263 spin_unlock_irq(&conf->device_lock);
4264 mddev->raid_disks = conf->geo.raid_disks;
4265 mddev->reshape_position = conf->reshape_progress;
4266 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
4267
4268 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4269 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4270 clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
4271 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4272 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4273
4274 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4275 "reshape");
4276 if (!mddev->sync_thread) {
4277 ret = -EAGAIN;
4278 goto abort;
4279 }
4280 conf->reshape_checkpoint = jiffies;
4281 md_wakeup_thread(mddev->sync_thread);
4282 md_new_event(mddev);
4283 return 0;
4284
4285abort:
4286 mddev->recovery = 0;
4287 spin_lock_irq(&conf->device_lock);
4288 conf->geo = conf->prev;
4289 mddev->raid_disks = conf->geo.raid_disks;
4290 rdev_for_each(rdev, mddev)
4291 rdev->new_data_offset = rdev->data_offset;
4292 smp_wmb();
4293 conf->reshape_progress = MaxSector;
4294 conf->reshape_safe = MaxSector;
4295 mddev->reshape_position = MaxSector;
4296 spin_unlock_irq(&conf->device_lock);
4297 return ret;
4298}
4299
4300/* Calculate the last device-address that could contain
4301 * any block from the chunk that includes the array-address 's'
4302 * and report the next address.
4303 * i.e. the address returned will be chunk-aligned and after
4304 * any data that is in the chunk containing 's'.
4305 */
4306static sector_t last_dev_address(sector_t s, struct geom *geo)
4307{
4308 s = (s | geo->chunk_mask) + 1;
4309 s >>= geo->chunk_shift;
4310 s *= geo->near_copies;
4311 s = DIV_ROUND_UP_SECTOR_T(s, geo->raid_disks);
4312 s *= geo->far_copies;
4313 s <<= geo->chunk_shift;
4314 return s;
4315}
4316
4317/* Calculate the first device-address that could contain
4318 * any block from the chunk that includes the array-address 's'.
4319 * This too will be the start of a chunk
4320 */
4321static sector_t first_dev_address(sector_t s, struct geom *geo)
4322{
4323 s >>= geo->chunk_shift;
4324 s *= geo->near_copies;
4325 sector_div(s, geo->raid_disks);
4326 s *= geo->far_copies;
4327 s <<= geo->chunk_shift;
4328 return s;
4329}
4330
4331static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
4332 int *skipped)
4333{
4334 /* We simply copy at most one chunk (smallest of old and new)
4335 * at a time, possibly less if that exceeds RESYNC_PAGES,
4336 * or we hit a bad block or something.
4337 * This might mean we pause for normal IO in the middle of
4338 * a chunk, but that is not a problem as mddev->reshape_position
4339 * can record any location.
4340 *
4341 * If we will want to write to a location that isn't
4342 * yet recorded as 'safe' (i.e. in metadata on disk) then
4343 * we need to flush all reshape requests and update the metadata.
4344 *
4345 * When reshaping forwards (e.g. to more devices), we interpret
4346 * 'safe' as the earliest block which might not have been copied
4347 * down yet. We divide this by previous stripe size and multiply
4348 * by previous stripe length to get lowest device offset that we
4349 * cannot write to yet.
4350 * We interpret 'sector_nr' as an address that we want to write to.
4351 * From this we use last_device_address() to find where we might
4352 * write to, and first_device_address on the 'safe' position.
4353 * If this 'next' write position is after the 'safe' position,
4354 * we must update the metadata to increase the 'safe' position.
4355 *
4356 * When reshaping backwards, we round in the opposite direction
4357 * and perform the reverse test: next write position must not be
4358 * less than current safe position.
4359 *
4360 * In all this the minimum difference in data offsets
4361 * (conf->offset_diff - always positive) allows a bit of slack,
4362 * so next can be after 'safe', but not by more than offset_diff
4363 *
4364 * We need to prepare all the bios here before we start any IO
4365 * to ensure the size we choose is acceptable to all devices.
4366 * The means one for each copy for write-out and an extra one for
4367 * read-in.
4368 * We store the read-in bio in ->master_bio and the others in
4369 * ->devs[x].bio and ->devs[x].repl_bio.
4370 */
4371 struct r10conf *conf = mddev->private;
4372 struct r10bio *r10_bio;
4373 sector_t next, safe, last;
4374 int max_sectors;
4375 int nr_sectors;
4376 int s;
4377 struct md_rdev *rdev;
4378 int need_flush = 0;
4379 struct bio *blist;
4380 struct bio *bio, *read_bio;
4381 int sectors_done = 0;
4382
4383 if (sector_nr == 0) {
4384 /* If restarting in the middle, skip the initial sectors */
4385 if (mddev->reshape_backwards &&
4386 conf->reshape_progress < raid10_size(mddev, 0, 0)) {
4387 sector_nr = (raid10_size(mddev, 0, 0)
4388 - conf->reshape_progress);
4389 } else if (!mddev->reshape_backwards &&
4390 conf->reshape_progress > 0)
4391 sector_nr = conf->reshape_progress;
4392 if (sector_nr) {
4393 mddev->curr_resync_completed = sector_nr;
4394 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4395 *skipped = 1;
4396 return sector_nr;
4397 }
4398 }
4399
4400 /* We don't use sector_nr to track where we are up to
4401 * as that doesn't work well for ->reshape_backwards.
4402 * So just use ->reshape_progress.
4403 */
4404 if (mddev->reshape_backwards) {
4405 /* 'next' is the earliest device address that we might
4406 * write to for this chunk in the new layout
4407 */
4408 next = first_dev_address(conf->reshape_progress - 1,
4409 &conf->geo);
4410
4411 /* 'safe' is the last device address that we might read from
4412 * in the old layout after a restart
4413 */
4414 safe = last_dev_address(conf->reshape_safe - 1,
4415 &conf->prev);
4416
4417 if (next + conf->offset_diff < safe)
4418 need_flush = 1;
4419
4420 last = conf->reshape_progress - 1;
4421 sector_nr = last & ~(sector_t)(conf->geo.chunk_mask
4422 & conf->prev.chunk_mask);
4423 if (sector_nr + RESYNC_BLOCK_SIZE/512 < last)
4424 sector_nr = last + 1 - RESYNC_BLOCK_SIZE/512;
4425 } else {
4426 /* 'next' is after the last device address that we
4427 * might write to for this chunk in the new layout
4428 */
4429 next = last_dev_address(conf->reshape_progress, &conf->geo);
4430
4431 /* 'safe' is the earliest device address that we might
4432 * read from in the old layout after a restart
4433 */
4434 safe = first_dev_address(conf->reshape_safe, &conf->prev);
4435
4436 /* Need to update metadata if 'next' might be beyond 'safe'
4437 * as that would possibly corrupt data
4438 */
4439 if (next > safe + conf->offset_diff)
4440 need_flush = 1;
4441
4442 sector_nr = conf->reshape_progress;
4443 last = sector_nr | (conf->geo.chunk_mask
4444 & conf->prev.chunk_mask);
4445
4446 if (sector_nr + RESYNC_BLOCK_SIZE/512 <= last)
4447 last = sector_nr + RESYNC_BLOCK_SIZE/512 - 1;
4448 }
4449
4450 if (need_flush ||
4451 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
4452 /* Need to update reshape_position in metadata */
4453 wait_barrier(conf);
4454 mddev->reshape_position = conf->reshape_progress;
4455 if (mddev->reshape_backwards)
4456 mddev->curr_resync_completed = raid10_size(mddev, 0, 0)
4457 - conf->reshape_progress;
4458 else
4459 mddev->curr_resync_completed = conf->reshape_progress;
4460 conf->reshape_checkpoint = jiffies;
4461 set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
4462 md_wakeup_thread(mddev->thread);
4463 wait_event(mddev->sb_wait, mddev->sb_flags == 0 ||
4464 test_bit(MD_RECOVERY_INTR, &mddev->recovery));
4465 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
4466 allow_barrier(conf);
4467 return sectors_done;
4468 }
4469 conf->reshape_safe = mddev->reshape_position;
4470 allow_barrier(conf);
4471 }
4472
4473read_more:
4474 /* Now schedule reads for blocks from sector_nr to last */
4475 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
4476 r10_bio->state = 0;
4477 raise_barrier(conf, sectors_done != 0);
4478 atomic_set(&r10_bio->remaining, 0);
4479 r10_bio->mddev = mddev;
4480 r10_bio->sector = sector_nr;
4481 set_bit(R10BIO_IsReshape, &r10_bio->state);
4482 r10_bio->sectors = last - sector_nr + 1;
4483 rdev = read_balance(conf, r10_bio, &max_sectors);
4484 BUG_ON(!test_bit(R10BIO_Previous, &r10_bio->state));
4485
4486 if (!rdev) {
4487 /* Cannot read from here, so need to record bad blocks
4488 * on all the target devices.
4489 */
4490 // FIXME
4491 mempool_free(r10_bio, conf->r10buf_pool);
4492 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4493 return sectors_done;
4494 }
4495
4496 read_bio = bio_alloc_mddev(GFP_KERNEL, RESYNC_PAGES, mddev);
4497
4498 read_bio->bi_bdev = rdev->bdev;
4499 read_bio->bi_iter.bi_sector = (r10_bio->devs[r10_bio->read_slot].addr
4500 + rdev->data_offset);
4501 read_bio->bi_private = r10_bio;
4502 read_bio->bi_end_io = end_sync_read;
4503 bio_set_op_attrs(read_bio, REQ_OP_READ, 0);
4504 read_bio->bi_flags &= (~0UL << BIO_RESET_BITS);
4505 read_bio->bi_error = 0;
4506 read_bio->bi_vcnt = 0;
4507 read_bio->bi_iter.bi_size = 0;
4508 r10_bio->master_bio = read_bio;
4509 r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
4510
4511 /* Now find the locations in the new layout */
4512 __raid10_find_phys(&conf->geo, r10_bio);
4513
4514 blist = read_bio;
4515 read_bio->bi_next = NULL;
4516
4517 rcu_read_lock();
4518 for (s = 0; s < conf->copies*2; s++) {
4519 struct bio *b;
4520 int d = r10_bio->devs[s/2].devnum;
4521 struct md_rdev *rdev2;
4522 if (s&1) {
4523 rdev2 = rcu_dereference(conf->mirrors[d].replacement);
4524 b = r10_bio->devs[s/2].repl_bio;
4525 } else {
4526 rdev2 = rcu_dereference(conf->mirrors[d].rdev);
4527 b = r10_bio->devs[s/2].bio;
4528 }
4529 if (!rdev2 || test_bit(Faulty, &rdev2->flags))
4530 continue;
4531
4532 bio_reset(b);
4533 b->bi_bdev = rdev2->bdev;
4534 b->bi_iter.bi_sector = r10_bio->devs[s/2].addr +
4535 rdev2->new_data_offset;
4536 b->bi_private = r10_bio;
4537 b->bi_end_io = end_reshape_write;
4538 bio_set_op_attrs(b, REQ_OP_WRITE, 0);
4539 b->bi_next = blist;
4540 blist = b;
4541 }
4542
4543 /* Now add as many pages as possible to all of these bios. */
4544
4545 nr_sectors = 0;
4546 for (s = 0 ; s < max_sectors; s += PAGE_SIZE >> 9) {
4547 struct page *page = r10_bio->devs[0].bio->bi_io_vec[s/(PAGE_SIZE>>9)].bv_page;
4548 int len = (max_sectors - s) << 9;
4549 if (len > PAGE_SIZE)
4550 len = PAGE_SIZE;
4551 for (bio = blist; bio ; bio = bio->bi_next) {
4552 struct bio *bio2;
4553 if (bio_add_page(bio, page, len, 0))
4554 continue;
4555
4556 /* Didn't fit, must stop */
4557 for (bio2 = blist;
4558 bio2 && bio2 != bio;
4559 bio2 = bio2->bi_next) {
4560 /* Remove last page from this bio */
4561 bio2->bi_vcnt--;
4562 bio2->bi_iter.bi_size -= len;
4563 bio_clear_flag(bio2, BIO_SEG_VALID);
4564 }
4565 goto bio_full;
4566 }
4567 sector_nr += len >> 9;
4568 nr_sectors += len >> 9;
4569 }
4570bio_full:
4571 rcu_read_unlock();
4572 r10_bio->sectors = nr_sectors;
4573
4574 /* Now submit the read */
4575 md_sync_acct(read_bio->bi_bdev, r10_bio->sectors);
4576 atomic_inc(&r10_bio->remaining);
4577 read_bio->bi_next = NULL;
4578 generic_make_request(read_bio);
4579 sector_nr += nr_sectors;
4580 sectors_done += nr_sectors;
4581 if (sector_nr <= last)
4582 goto read_more;
4583
4584 /* Now that we have done the whole section we can
4585 * update reshape_progress
4586 */
4587 if (mddev->reshape_backwards)
4588 conf->reshape_progress -= sectors_done;
4589 else
4590 conf->reshape_progress += sectors_done;
4591
4592 return sectors_done;
4593}
4594
4595static void end_reshape_request(struct r10bio *r10_bio);
4596static int handle_reshape_read_error(struct mddev *mddev,
4597 struct r10bio *r10_bio);
4598static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio)
4599{
4600 /* Reshape read completed. Hopefully we have a block
4601 * to write out.
4602 * If we got a read error then we do sync 1-page reads from
4603 * elsewhere until we find the data - or give up.
4604 */
4605 struct r10conf *conf = mddev->private;
4606 int s;
4607
4608 if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
4609 if (handle_reshape_read_error(mddev, r10_bio) < 0) {
4610 /* Reshape has been aborted */
4611 md_done_sync(mddev, r10_bio->sectors, 0);
4612 return;
4613 }
4614
4615 /* We definitely have the data in the pages, schedule the
4616 * writes.
4617 */
4618 atomic_set(&r10_bio->remaining, 1);
4619 for (s = 0; s < conf->copies*2; s++) {
4620 struct bio *b;
4621 int d = r10_bio->devs[s/2].devnum;
4622 struct md_rdev *rdev;
4623 rcu_read_lock();
4624 if (s&1) {
4625 rdev = rcu_dereference(conf->mirrors[d].replacement);
4626 b = r10_bio->devs[s/2].repl_bio;
4627 } else {
4628 rdev = rcu_dereference(conf->mirrors[d].rdev);
4629 b = r10_bio->devs[s/2].bio;
4630 }
4631 if (!rdev || test_bit(Faulty, &rdev->flags)) {
4632 rcu_read_unlock();
4633 continue;
4634 }
4635 atomic_inc(&rdev->nr_pending);
4636 rcu_read_unlock();
4637 md_sync_acct(b->bi_bdev, r10_bio->sectors);
4638 atomic_inc(&r10_bio->remaining);
4639 b->bi_next = NULL;
4640 generic_make_request(b);
4641 }
4642 end_reshape_request(r10_bio);
4643}
4644
4645static void end_reshape(struct r10conf *conf)
4646{
4647 if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery))
4648 return;
4649
4650 spin_lock_irq(&conf->device_lock);
4651 conf->prev = conf->geo;
4652 md_finish_reshape(conf->mddev);
4653 smp_wmb();
4654 conf->reshape_progress = MaxSector;
4655 conf->reshape_safe = MaxSector;
4656 spin_unlock_irq(&conf->device_lock);
4657
4658 /* read-ahead size must cover two whole stripes, which is
4659 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4660 */
4661 if (conf->mddev->queue) {
4662 int stripe = conf->geo.raid_disks *
4663 ((conf->mddev->chunk_sectors << 9) / PAGE_SIZE);
4664 stripe /= conf->geo.near_copies;
4665 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4666 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4667 }
4668 conf->fullsync = 0;
4669}
4670
4671static int handle_reshape_read_error(struct mddev *mddev,
4672 struct r10bio *r10_bio)
4673{
4674 /* Use sync reads to get the blocks from somewhere else */
4675 int sectors = r10_bio->sectors;
4676 struct r10conf *conf = mddev->private;
4677 struct {
4678 struct r10bio r10_bio;
4679 struct r10dev devs[conf->copies];
4680 } on_stack;
4681 struct r10bio *r10b = &on_stack.r10_bio;
4682 int slot = 0;
4683 int idx = 0;
4684 struct bio_vec *bvec = r10_bio->master_bio->bi_io_vec;
4685
4686 r10b->sector = r10_bio->sector;
4687 __raid10_find_phys(&conf->prev, r10b);
4688
4689 while (sectors) {
4690 int s = sectors;
4691 int success = 0;
4692 int first_slot = slot;
4693
4694 if (s > (PAGE_SIZE >> 9))
4695 s = PAGE_SIZE >> 9;
4696
4697 rcu_read_lock();
4698 while (!success) {
4699 int d = r10b->devs[slot].devnum;
4700 struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
4701 sector_t addr;
4702 if (rdev == NULL ||
4703 test_bit(Faulty, &rdev->flags) ||
4704 !test_bit(In_sync, &rdev->flags))
4705 goto failed;
4706
4707 addr = r10b->devs[slot].addr + idx * PAGE_SIZE;
4708 atomic_inc(&rdev->nr_pending);
4709 rcu_read_unlock();
4710 success = sync_page_io(rdev,
4711 addr,
4712 s << 9,
4713 bvec[idx].bv_page,
4714 REQ_OP_READ, 0, false);
4715 rdev_dec_pending(rdev, mddev);
4716 rcu_read_lock();
4717 if (success)
4718 break;
4719 failed:
4720 slot++;
4721 if (slot >= conf->copies)
4722 slot = 0;
4723 if (slot == first_slot)
4724 break;
4725 }
4726 rcu_read_unlock();
4727 if (!success) {
4728 /* couldn't read this block, must give up */
4729 set_bit(MD_RECOVERY_INTR,
4730 &mddev->recovery);
4731 return -EIO;
4732 }
4733 sectors -= s;
4734 idx++;
4735 }
4736 return 0;
4737}
4738
4739static void end_reshape_write(struct bio *bio)
4740{
4741 struct r10bio *r10_bio = bio->bi_private;
4742 struct mddev *mddev = r10_bio->mddev;
4743 struct r10conf *conf = mddev->private;
4744 int d;
4745 int slot;
4746 int repl;
4747 struct md_rdev *rdev = NULL;
4748
4749 d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
4750 if (repl)
4751 rdev = conf->mirrors[d].replacement;
4752 if (!rdev) {
4753 smp_mb();
4754 rdev = conf->mirrors[d].rdev;
4755 }
4756
4757 if (bio->bi_error) {
4758 /* FIXME should record badblock */
4759 md_error(mddev, rdev);
4760 }
4761
4762 rdev_dec_pending(rdev, mddev);
4763 end_reshape_request(r10_bio);
4764}
4765
4766static void end_reshape_request(struct r10bio *r10_bio)
4767{
4768 if (!atomic_dec_and_test(&r10_bio->remaining))
4769 return;
4770 md_done_sync(r10_bio->mddev, r10_bio->sectors, 1);
4771 bio_put(r10_bio->master_bio);
4772 put_buf(r10_bio);
4773}
4774
4775static void raid10_finish_reshape(struct mddev *mddev)
4776{
4777 struct r10conf *conf = mddev->private;
4778
4779 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
4780 return;
4781
4782 if (mddev->delta_disks > 0) {
4783 sector_t size = raid10_size(mddev, 0, 0);
4784 md_set_array_sectors(mddev, size);
4785 if (mddev->recovery_cp > mddev->resync_max_sectors) {
4786 mddev->recovery_cp = mddev->resync_max_sectors;
4787 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4788 }
4789 mddev->resync_max_sectors = size;
4790 if (mddev->queue) {
4791 set_capacity(mddev->gendisk, mddev->array_sectors);
4792 revalidate_disk(mddev->gendisk);
4793 }
4794 } else {
4795 int d;
4796 rcu_read_lock();
4797 for (d = conf->geo.raid_disks ;
4798 d < conf->geo.raid_disks - mddev->delta_disks;
4799 d++) {
4800 struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
4801 if (rdev)
4802 clear_bit(In_sync, &rdev->flags);
4803 rdev = rcu_dereference(conf->mirrors[d].replacement);
4804 if (rdev)
4805 clear_bit(In_sync, &rdev->flags);
4806 }
4807 rcu_read_unlock();
4808 }
4809 mddev->layout = mddev->new_layout;
4810 mddev->chunk_sectors = 1 << conf->geo.chunk_shift;
4811 mddev->reshape_position = MaxSector;
4812 mddev->delta_disks = 0;
4813 mddev->reshape_backwards = 0;
4814}
4815
4816static struct md_personality raid10_personality =
4817{
4818 .name = "raid10",
4819 .level = 10,
4820 .owner = THIS_MODULE,
4821 .make_request = raid10_make_request,
4822 .run = raid10_run,
4823 .free = raid10_free,
4824 .status = raid10_status,
4825 .error_handler = raid10_error,
4826 .hot_add_disk = raid10_add_disk,
4827 .hot_remove_disk= raid10_remove_disk,
4828 .spare_active = raid10_spare_active,
4829 .sync_request = raid10_sync_request,
4830 .quiesce = raid10_quiesce,
4831 .size = raid10_size,
4832 .resize = raid10_resize,
4833 .takeover = raid10_takeover,
4834 .check_reshape = raid10_check_reshape,
4835 .start_reshape = raid10_start_reshape,
4836 .finish_reshape = raid10_finish_reshape,
4837 .congested = raid10_congested,
4838};
4839
4840static int __init raid_init(void)
4841{
4842 return register_md_personality(&raid10_personality);
4843}
4844
4845static void raid_exit(void)
4846{
4847 unregister_md_personality(&raid10_personality);
4848}
4849
4850module_init(raid_init);
4851module_exit(raid_exit);
4852MODULE_LICENSE("GPL");
4853MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
4854MODULE_ALIAS("md-personality-9"); /* RAID10 */
4855MODULE_ALIAS("md-raid10");
4856MODULE_ALIAS("md-level-10");
4857
4858module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);