drm/i915: Keep the CRC values into a circular buffer
[deliverable/linux.git] / drivers / md / raid10.c
CommitLineData
1da177e4
LT
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 *
25985edc 8 * Base on code in raid1.c. See raid1.c for further copyright information.
1da177e4
LT
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
5a0e3ad6 21#include <linux/slab.h>
25570727 22#include <linux/delay.h>
bff61975 23#include <linux/blkdev.h>
056075c7 24#include <linux/module.h>
bff61975 25#include <linux/seq_file.h>
8bda470e 26#include <linux/ratelimit.h>
3ea7daa5 27#include <linux/kthread.h>
43b2e5d8 28#include "md.h"
ef740c37 29#include "raid10.h"
dab8b292 30#include "raid0.h"
ef740c37 31#include "bitmap.h"
1da177e4
LT
32
33/*
34 * RAID10 provides a combination of RAID0 and RAID1 functionality.
35 * The layout of data is defined by
36 * chunk_size
37 * raid_disks
38 * near_copies (stored in low byte of layout)
39 * far_copies (stored in second byte of layout)
c93983bf 40 * far_offset (stored in bit 16 of layout )
475901af 41 * use_far_sets (stored in bit 17 of layout )
1da177e4 42 *
475901af
JB
43 * The data to be stored is divided into chunks using chunksize. Each device
44 * is divided into far_copies sections. In each section, chunks are laid out
45 * in a style similar to raid0, but near_copies copies of each chunk is stored
46 * (each on a different drive). The starting device for each section is offset
47 * near_copies from the starting device of the previous section. Thus there
48 * are (near_copies * far_copies) of each chunk, and each is on a different
49 * drive. near_copies and far_copies must be at least one, and their product
50 * is at most raid_disks.
c93983bf
N
51 *
52 * If far_offset is true, then the far_copies are handled a bit differently.
475901af
JB
53 * The copies are still in different stripes, but instead of being very far
54 * apart on disk, there are adjacent stripes.
55 *
56 * The far and offset algorithms are handled slightly differently if
57 * 'use_far_sets' is true. In this case, the array's devices are grouped into
58 * sets that are (near_copies * far_copies) in size. The far copied stripes
59 * are still shifted by 'near_copies' devices, but this shifting stays confined
60 * to the set rather than the entire array. This is done to improve the number
61 * of device combinations that can fail without causing the array to fail.
62 * Example 'far' algorithm w/o 'use_far_sets' (each letter represents a chunk
63 * on a device):
64 * A B C D A B C D E
65 * ... ...
66 * D A B C E A B C D
67 * Example 'far' algorithm w/ 'use_far_sets' enabled (sets illustrated w/ []'s):
68 * [A B] [C D] [A B] [C D E]
69 * |...| |...| |...| | ... |
70 * [B A] [D C] [B A] [E C D]
1da177e4
LT
71 */
72
73/*
74 * Number of guaranteed r10bios in case of extreme VM load:
75 */
76#define NR_RAID10_BIOS 256
77
473e87ce
JB
78/* when we get a read error on a read-only array, we redirect to another
79 * device without failing the first device, or trying to over-write to
80 * correct the read error. To keep track of bad blocks on a per-bio
81 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
82 */
83#define IO_BLOCKED ((struct bio *)1)
84/* When we successfully write to a known bad-block, we need to remove the
85 * bad-block marking which must be done from process context. So we record
86 * the success by setting devs[n].bio to IO_MADE_GOOD
87 */
88#define IO_MADE_GOOD ((struct bio *)2)
89
90#define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
91
92/* When there are this many requests queued to be written by
34db0cd6
N
93 * the raid10 thread, we become 'congested' to provide back-pressure
94 * for writeback.
95 */
96static int max_queued_requests = 1024;
97
e879a879
N
98static void allow_barrier(struct r10conf *conf);
99static void lower_barrier(struct r10conf *conf);
635f6416 100static int _enough(struct r10conf *conf, int previous, int ignore);
3ea7daa5
N
101static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
102 int *skipped);
103static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio);
104static void end_reshape_write(struct bio *bio, int error);
105static void end_reshape(struct r10conf *conf);
0a27ec96 106
dd0fc66f 107static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
1da177e4 108{
e879a879 109 struct r10conf *conf = data;
9f2c9d12 110 int size = offsetof(struct r10bio, devs[conf->copies]);
1da177e4 111
69335ef3
N
112 /* allocate a r10bio with room for raid_disks entries in the
113 * bios array */
7eaceacc 114 return kzalloc(size, gfp_flags);
1da177e4
LT
115}
116
117static void r10bio_pool_free(void *r10_bio, void *data)
118{
119 kfree(r10_bio);
120}
121
0310fa21 122/* Maximum size of each resync request */
1da177e4 123#define RESYNC_BLOCK_SIZE (64*1024)
1da177e4 124#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
0310fa21
N
125/* amount of memory to reserve for resync requests */
126#define RESYNC_WINDOW (1024*1024)
127/* maximum number of concurrent requests, memory permitting */
128#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE)
1da177e4
LT
129
130/*
131 * When performing a resync, we need to read and compare, so
132 * we need as many pages are there are copies.
133 * When performing a recovery, we need 2 bios, one for read,
134 * one for write (we recover only one drive per r10buf)
135 *
136 */
dd0fc66f 137static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
1da177e4 138{
e879a879 139 struct r10conf *conf = data;
1da177e4 140 struct page *page;
9f2c9d12 141 struct r10bio *r10_bio;
1da177e4
LT
142 struct bio *bio;
143 int i, j;
144 int nalloc;
145
146 r10_bio = r10bio_pool_alloc(gfp_flags, conf);
7eaceacc 147 if (!r10_bio)
1da177e4 148 return NULL;
1da177e4 149
3ea7daa5
N
150 if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery) ||
151 test_bit(MD_RECOVERY_RESHAPE, &conf->mddev->recovery))
1da177e4
LT
152 nalloc = conf->copies; /* resync */
153 else
154 nalloc = 2; /* recovery */
155
156 /*
157 * Allocate bios.
158 */
159 for (j = nalloc ; j-- ; ) {
6746557f 160 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
1da177e4
LT
161 if (!bio)
162 goto out_free_bio;
163 r10_bio->devs[j].bio = bio;
69335ef3
N
164 if (!conf->have_replacement)
165 continue;
166 bio = bio_kmalloc(gfp_flags, RESYNC_PAGES);
167 if (!bio)
168 goto out_free_bio;
169 r10_bio->devs[j].repl_bio = bio;
1da177e4
LT
170 }
171 /*
172 * Allocate RESYNC_PAGES data pages and attach them
173 * where needed.
174 */
175 for (j = 0 ; j < nalloc; j++) {
69335ef3 176 struct bio *rbio = r10_bio->devs[j].repl_bio;
1da177e4
LT
177 bio = r10_bio->devs[j].bio;
178 for (i = 0; i < RESYNC_PAGES; i++) {
3ea7daa5
N
179 if (j > 0 && !test_bit(MD_RECOVERY_SYNC,
180 &conf->mddev->recovery)) {
181 /* we can share bv_page's during recovery
182 * and reshape */
c65060ad
NK
183 struct bio *rbio = r10_bio->devs[0].bio;
184 page = rbio->bi_io_vec[i].bv_page;
185 get_page(page);
186 } else
187 page = alloc_page(gfp_flags);
1da177e4
LT
188 if (unlikely(!page))
189 goto out_free_pages;
190
191 bio->bi_io_vec[i].bv_page = page;
69335ef3
N
192 if (rbio)
193 rbio->bi_io_vec[i].bv_page = page;
1da177e4
LT
194 }
195 }
196
197 return r10_bio;
198
199out_free_pages:
200 for ( ; i > 0 ; i--)
1345b1d8 201 safe_put_page(bio->bi_io_vec[i-1].bv_page);
1da177e4
LT
202 while (j--)
203 for (i = 0; i < RESYNC_PAGES ; i++)
1345b1d8 204 safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page);
5fdd2cf8 205 j = 0;
1da177e4 206out_free_bio:
5fdd2cf8 207 for ( ; j < nalloc; j++) {
208 if (r10_bio->devs[j].bio)
209 bio_put(r10_bio->devs[j].bio);
69335ef3
N
210 if (r10_bio->devs[j].repl_bio)
211 bio_put(r10_bio->devs[j].repl_bio);
212 }
1da177e4
LT
213 r10bio_pool_free(r10_bio, conf);
214 return NULL;
215}
216
217static void r10buf_pool_free(void *__r10_bio, void *data)
218{
219 int i;
e879a879 220 struct r10conf *conf = data;
9f2c9d12 221 struct r10bio *r10bio = __r10_bio;
1da177e4
LT
222 int j;
223
224 for (j=0; j < conf->copies; j++) {
225 struct bio *bio = r10bio->devs[j].bio;
226 if (bio) {
227 for (i = 0; i < RESYNC_PAGES; i++) {
1345b1d8 228 safe_put_page(bio->bi_io_vec[i].bv_page);
1da177e4
LT
229 bio->bi_io_vec[i].bv_page = NULL;
230 }
231 bio_put(bio);
232 }
69335ef3
N
233 bio = r10bio->devs[j].repl_bio;
234 if (bio)
235 bio_put(bio);
1da177e4
LT
236 }
237 r10bio_pool_free(r10bio, conf);
238}
239
e879a879 240static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio)
1da177e4
LT
241{
242 int i;
243
244 for (i = 0; i < conf->copies; i++) {
245 struct bio **bio = & r10_bio->devs[i].bio;
749c55e9 246 if (!BIO_SPECIAL(*bio))
1da177e4
LT
247 bio_put(*bio);
248 *bio = NULL;
69335ef3
N
249 bio = &r10_bio->devs[i].repl_bio;
250 if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio))
251 bio_put(*bio);
252 *bio = NULL;
1da177e4
LT
253 }
254}
255
9f2c9d12 256static void free_r10bio(struct r10bio *r10_bio)
1da177e4 257{
e879a879 258 struct r10conf *conf = r10_bio->mddev->private;
1da177e4 259
1da177e4
LT
260 put_all_bios(conf, r10_bio);
261 mempool_free(r10_bio, conf->r10bio_pool);
262}
263
9f2c9d12 264static void put_buf(struct r10bio *r10_bio)
1da177e4 265{
e879a879 266 struct r10conf *conf = r10_bio->mddev->private;
1da177e4
LT
267
268 mempool_free(r10_bio, conf->r10buf_pool);
269
0a27ec96 270 lower_barrier(conf);
1da177e4
LT
271}
272
9f2c9d12 273static void reschedule_retry(struct r10bio *r10_bio)
1da177e4
LT
274{
275 unsigned long flags;
fd01b88c 276 struct mddev *mddev = r10_bio->mddev;
e879a879 277 struct r10conf *conf = mddev->private;
1da177e4
LT
278
279 spin_lock_irqsave(&conf->device_lock, flags);
280 list_add(&r10_bio->retry_list, &conf->retry_list);
4443ae10 281 conf->nr_queued ++;
1da177e4
LT
282 spin_unlock_irqrestore(&conf->device_lock, flags);
283
388667be
AJ
284 /* wake up frozen array... */
285 wake_up(&conf->wait_barrier);
286
1da177e4
LT
287 md_wakeup_thread(mddev->thread);
288}
289
290/*
291 * raid_end_bio_io() is called when we have finished servicing a mirrored
292 * operation and are ready to return a success/failure code to the buffer
293 * cache layer.
294 */
9f2c9d12 295static void raid_end_bio_io(struct r10bio *r10_bio)
1da177e4
LT
296{
297 struct bio *bio = r10_bio->master_bio;
856e08e2 298 int done;
e879a879 299 struct r10conf *conf = r10_bio->mddev->private;
1da177e4 300
856e08e2
N
301 if (bio->bi_phys_segments) {
302 unsigned long flags;
303 spin_lock_irqsave(&conf->device_lock, flags);
304 bio->bi_phys_segments--;
305 done = (bio->bi_phys_segments == 0);
306 spin_unlock_irqrestore(&conf->device_lock, flags);
307 } else
308 done = 1;
309 if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
310 clear_bit(BIO_UPTODATE, &bio->bi_flags);
311 if (done) {
312 bio_endio(bio, 0);
313 /*
314 * Wake up any possible resync thread that waits for the device
315 * to go idle.
316 */
317 allow_barrier(conf);
318 }
1da177e4
LT
319 free_r10bio(r10_bio);
320}
321
322/*
323 * Update disk head position estimator based on IRQ completion info.
324 */
9f2c9d12 325static inline void update_head_pos(int slot, struct r10bio *r10_bio)
1da177e4 326{
e879a879 327 struct r10conf *conf = r10_bio->mddev->private;
1da177e4
LT
328
329 conf->mirrors[r10_bio->devs[slot].devnum].head_position =
330 r10_bio->devs[slot].addr + (r10_bio->sectors);
331}
332
778ca018
NK
333/*
334 * Find the disk number which triggered given bio
335 */
e879a879 336static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio,
69335ef3 337 struct bio *bio, int *slotp, int *replp)
778ca018
NK
338{
339 int slot;
69335ef3 340 int repl = 0;
778ca018 341
69335ef3 342 for (slot = 0; slot < conf->copies; slot++) {
778ca018
NK
343 if (r10_bio->devs[slot].bio == bio)
344 break;
69335ef3
N
345 if (r10_bio->devs[slot].repl_bio == bio) {
346 repl = 1;
347 break;
348 }
349 }
778ca018
NK
350
351 BUG_ON(slot == conf->copies);
352 update_head_pos(slot, r10_bio);
353
749c55e9
N
354 if (slotp)
355 *slotp = slot;
69335ef3
N
356 if (replp)
357 *replp = repl;
778ca018
NK
358 return r10_bio->devs[slot].devnum;
359}
360
6712ecf8 361static void raid10_end_read_request(struct bio *bio, int error)
1da177e4
LT
362{
363 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
9f2c9d12 364 struct r10bio *r10_bio = bio->bi_private;
1da177e4 365 int slot, dev;
abbf098e 366 struct md_rdev *rdev;
e879a879 367 struct r10conf *conf = r10_bio->mddev->private;
1da177e4 368
1da177e4
LT
369
370 slot = r10_bio->read_slot;
371 dev = r10_bio->devs[slot].devnum;
abbf098e 372 rdev = r10_bio->devs[slot].rdev;
1da177e4
LT
373 /*
374 * this branch is our 'one mirror IO has finished' event handler:
375 */
4443ae10
N
376 update_head_pos(slot, r10_bio);
377
378 if (uptodate) {
1da177e4
LT
379 /*
380 * Set R10BIO_Uptodate in our master bio, so that
381 * we will return a good error code to the higher
382 * levels even if IO on some other mirrored buffer fails.
383 *
384 * The 'master' represents the composite IO operation to
385 * user-side. So if something waits for IO, then it will
386 * wait for the 'master' bio.
387 */
388 set_bit(R10BIO_Uptodate, &r10_bio->state);
fae8cc5e
N
389 } else {
390 /* If all other devices that store this block have
391 * failed, we want to return the error upwards rather
392 * than fail the last device. Here we redefine
393 * "uptodate" to mean "Don't want to retry"
394 */
635f6416
N
395 if (!_enough(conf, test_bit(R10BIO_Previous, &r10_bio->state),
396 rdev->raid_disk))
fae8cc5e 397 uptodate = 1;
fae8cc5e
N
398 }
399 if (uptodate) {
1da177e4 400 raid_end_bio_io(r10_bio);
abbf098e 401 rdev_dec_pending(rdev, conf->mddev);
4443ae10 402 } else {
1da177e4 403 /*
7c4e06ff 404 * oops, read error - keep the refcount on the rdev
1da177e4
LT
405 */
406 char b[BDEVNAME_SIZE];
8bda470e
CD
407 printk_ratelimited(KERN_ERR
408 "md/raid10:%s: %s: rescheduling sector %llu\n",
409 mdname(conf->mddev),
abbf098e 410 bdevname(rdev->bdev, b),
8bda470e 411 (unsigned long long)r10_bio->sector);
856e08e2 412 set_bit(R10BIO_ReadError, &r10_bio->state);
1da177e4
LT
413 reschedule_retry(r10_bio);
414 }
1da177e4
LT
415}
416
9f2c9d12 417static void close_write(struct r10bio *r10_bio)
bd870a16
N
418{
419 /* clear the bitmap if all writes complete successfully */
420 bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
421 r10_bio->sectors,
422 !test_bit(R10BIO_Degraded, &r10_bio->state),
423 0);
424 md_write_end(r10_bio->mddev);
425}
426
9f2c9d12 427static void one_write_done(struct r10bio *r10_bio)
19d5f834
N
428{
429 if (atomic_dec_and_test(&r10_bio->remaining)) {
430 if (test_bit(R10BIO_WriteError, &r10_bio->state))
431 reschedule_retry(r10_bio);
432 else {
433 close_write(r10_bio);
434 if (test_bit(R10BIO_MadeGood, &r10_bio->state))
435 reschedule_retry(r10_bio);
436 else
437 raid_end_bio_io(r10_bio);
438 }
439 }
440}
441
6712ecf8 442static void raid10_end_write_request(struct bio *bio, int error)
1da177e4
LT
443{
444 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
9f2c9d12 445 struct r10bio *r10_bio = bio->bi_private;
778ca018 446 int dev;
749c55e9 447 int dec_rdev = 1;
e879a879 448 struct r10conf *conf = r10_bio->mddev->private;
475b0321 449 int slot, repl;
4ca40c2c 450 struct md_rdev *rdev = NULL;
1da177e4 451
475b0321 452 dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
1da177e4 453
475b0321
N
454 if (repl)
455 rdev = conf->mirrors[dev].replacement;
4ca40c2c
N
456 if (!rdev) {
457 smp_rmb();
458 repl = 0;
475b0321 459 rdev = conf->mirrors[dev].rdev;
4ca40c2c 460 }
1da177e4
LT
461 /*
462 * this branch is our 'one mirror IO has finished' event handler:
463 */
6cce3b23 464 if (!uptodate) {
475b0321
N
465 if (repl)
466 /* Never record new bad blocks to replacement,
467 * just fail it.
468 */
469 md_error(rdev->mddev, rdev);
470 else {
471 set_bit(WriteErrorSeen, &rdev->flags);
b7044d41
N
472 if (!test_and_set_bit(WantReplacement, &rdev->flags))
473 set_bit(MD_RECOVERY_NEEDED,
474 &rdev->mddev->recovery);
475b0321
N
475 set_bit(R10BIO_WriteError, &r10_bio->state);
476 dec_rdev = 0;
477 }
749c55e9 478 } else {
1da177e4
LT
479 /*
480 * Set R10BIO_Uptodate in our master bio, so that
481 * we will return a good error code for to the higher
482 * levels even if IO on some other mirrored buffer fails.
483 *
484 * The 'master' represents the composite IO operation to
485 * user-side. So if something waits for IO, then it will
486 * wait for the 'master' bio.
487 */
749c55e9
N
488 sector_t first_bad;
489 int bad_sectors;
490
3056e3ae
AL
491 /*
492 * Do not set R10BIO_Uptodate if the current device is
493 * rebuilding or Faulty. This is because we cannot use
494 * such device for properly reading the data back (we could
495 * potentially use it, if the current write would have felt
496 * before rdev->recovery_offset, but for simplicity we don't
497 * check this here.
498 */
499 if (test_bit(In_sync, &rdev->flags) &&
500 !test_bit(Faulty, &rdev->flags))
501 set_bit(R10BIO_Uptodate, &r10_bio->state);
1da177e4 502
749c55e9 503 /* Maybe we can clear some bad blocks. */
475b0321 504 if (is_badblock(rdev,
749c55e9
N
505 r10_bio->devs[slot].addr,
506 r10_bio->sectors,
507 &first_bad, &bad_sectors)) {
508 bio_put(bio);
475b0321
N
509 if (repl)
510 r10_bio->devs[slot].repl_bio = IO_MADE_GOOD;
511 else
512 r10_bio->devs[slot].bio = IO_MADE_GOOD;
749c55e9
N
513 dec_rdev = 0;
514 set_bit(R10BIO_MadeGood, &r10_bio->state);
515 }
516 }
517
1da177e4
LT
518 /*
519 *
520 * Let's see if all mirrored write operations have finished
521 * already.
522 */
19d5f834 523 one_write_done(r10_bio);
749c55e9 524 if (dec_rdev)
884162df 525 rdev_dec_pending(rdev, conf->mddev);
1da177e4
LT
526}
527
1da177e4
LT
528/*
529 * RAID10 layout manager
25985edc 530 * As well as the chunksize and raid_disks count, there are two
1da177e4
LT
531 * parameters: near_copies and far_copies.
532 * near_copies * far_copies must be <= raid_disks.
533 * Normally one of these will be 1.
534 * If both are 1, we get raid0.
535 * If near_copies == raid_disks, we get raid1.
536 *
25985edc 537 * Chunks are laid out in raid0 style with near_copies copies of the
1da177e4
LT
538 * first chunk, followed by near_copies copies of the next chunk and
539 * so on.
540 * If far_copies > 1, then after 1/far_copies of the array has been assigned
541 * as described above, we start again with a device offset of near_copies.
542 * So we effectively have another copy of the whole array further down all
543 * the drives, but with blocks on different drives.
544 * With this layout, and block is never stored twice on the one device.
545 *
546 * raid10_find_phys finds the sector offset of a given virtual sector
c93983bf 547 * on each device that it is on.
1da177e4
LT
548 *
549 * raid10_find_virt does the reverse mapping, from a device and a
550 * sector offset to a virtual address
551 */
552
f8c9e74f 553static void __raid10_find_phys(struct geom *geo, struct r10bio *r10bio)
1da177e4
LT
554{
555 int n,f;
556 sector_t sector;
557 sector_t chunk;
558 sector_t stripe;
559 int dev;
1da177e4 560 int slot = 0;
9a3152ab
JB
561 int last_far_set_start, last_far_set_size;
562
563 last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
564 last_far_set_start *= geo->far_set_size;
565
566 last_far_set_size = geo->far_set_size;
567 last_far_set_size += (geo->raid_disks % geo->far_set_size);
1da177e4
LT
568
569 /* now calculate first sector/dev */
5cf00fcd
N
570 chunk = r10bio->sector >> geo->chunk_shift;
571 sector = r10bio->sector & geo->chunk_mask;
1da177e4 572
5cf00fcd 573 chunk *= geo->near_copies;
1da177e4 574 stripe = chunk;
5cf00fcd
N
575 dev = sector_div(stripe, geo->raid_disks);
576 if (geo->far_offset)
577 stripe *= geo->far_copies;
1da177e4 578
5cf00fcd 579 sector += stripe << geo->chunk_shift;
1da177e4
LT
580
581 /* and calculate all the others */
5cf00fcd 582 for (n = 0; n < geo->near_copies; n++) {
1da177e4 583 int d = dev;
475901af 584 int set;
1da177e4 585 sector_t s = sector;
1da177e4 586 r10bio->devs[slot].devnum = d;
4c0ca26b 587 r10bio->devs[slot].addr = s;
1da177e4
LT
588 slot++;
589
5cf00fcd 590 for (f = 1; f < geo->far_copies; f++) {
475901af 591 set = d / geo->far_set_size;
5cf00fcd 592 d += geo->near_copies;
475901af 593
9a3152ab
JB
594 if ((geo->raid_disks % geo->far_set_size) &&
595 (d > last_far_set_start)) {
596 d -= last_far_set_start;
597 d %= last_far_set_size;
598 d += last_far_set_start;
599 } else {
600 d %= geo->far_set_size;
601 d += geo->far_set_size * set;
602 }
5cf00fcd 603 s += geo->stride;
1da177e4
LT
604 r10bio->devs[slot].devnum = d;
605 r10bio->devs[slot].addr = s;
606 slot++;
607 }
608 dev++;
5cf00fcd 609 if (dev >= geo->raid_disks) {
1da177e4 610 dev = 0;
5cf00fcd 611 sector += (geo->chunk_mask + 1);
1da177e4
LT
612 }
613 }
f8c9e74f
N
614}
615
616static void raid10_find_phys(struct r10conf *conf, struct r10bio *r10bio)
617{
618 struct geom *geo = &conf->geo;
619
620 if (conf->reshape_progress != MaxSector &&
621 ((r10bio->sector >= conf->reshape_progress) !=
622 conf->mddev->reshape_backwards)) {
623 set_bit(R10BIO_Previous, &r10bio->state);
624 geo = &conf->prev;
625 } else
626 clear_bit(R10BIO_Previous, &r10bio->state);
627
628 __raid10_find_phys(geo, r10bio);
1da177e4
LT
629}
630
e879a879 631static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev)
1da177e4
LT
632{
633 sector_t offset, chunk, vchunk;
f8c9e74f
N
634 /* Never use conf->prev as this is only called during resync
635 * or recovery, so reshape isn't happening
636 */
5cf00fcd 637 struct geom *geo = &conf->geo;
475901af
JB
638 int far_set_start = (dev / geo->far_set_size) * geo->far_set_size;
639 int far_set_size = geo->far_set_size;
9a3152ab
JB
640 int last_far_set_start;
641
642 if (geo->raid_disks % geo->far_set_size) {
643 last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
644 last_far_set_start *= geo->far_set_size;
645
646 if (dev >= last_far_set_start) {
647 far_set_size = geo->far_set_size;
648 far_set_size += (geo->raid_disks % geo->far_set_size);
649 far_set_start = last_far_set_start;
650 }
651 }
1da177e4 652
5cf00fcd
N
653 offset = sector & geo->chunk_mask;
654 if (geo->far_offset) {
c93983bf 655 int fc;
5cf00fcd
N
656 chunk = sector >> geo->chunk_shift;
657 fc = sector_div(chunk, geo->far_copies);
658 dev -= fc * geo->near_copies;
475901af
JB
659 if (dev < far_set_start)
660 dev += far_set_size;
c93983bf 661 } else {
5cf00fcd
N
662 while (sector >= geo->stride) {
663 sector -= geo->stride;
475901af
JB
664 if (dev < (geo->near_copies + far_set_start))
665 dev += far_set_size - geo->near_copies;
c93983bf 666 else
5cf00fcd 667 dev -= geo->near_copies;
c93983bf 668 }
5cf00fcd 669 chunk = sector >> geo->chunk_shift;
c93983bf 670 }
5cf00fcd
N
671 vchunk = chunk * geo->raid_disks + dev;
672 sector_div(vchunk, geo->near_copies);
673 return (vchunk << geo->chunk_shift) + offset;
1da177e4
LT
674}
675
676/**
677 * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged
678 * @q: request queue
cc371e66 679 * @bvm: properties of new bio
1da177e4
LT
680 * @biovec: the request that could be merged to it.
681 *
682 * Return amount of bytes we can accept at this offset
050b6615
N
683 * This requires checking for end-of-chunk if near_copies != raid_disks,
684 * and for subordinate merge_bvec_fns if merge_check_needed.
1da177e4 685 */
cc371e66
AK
686static int raid10_mergeable_bvec(struct request_queue *q,
687 struct bvec_merge_data *bvm,
688 struct bio_vec *biovec)
1da177e4 689{
fd01b88c 690 struct mddev *mddev = q->queuedata;
050b6615 691 struct r10conf *conf = mddev->private;
cc371e66 692 sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
1da177e4 693 int max;
3ea7daa5 694 unsigned int chunk_sectors;
cc371e66 695 unsigned int bio_sectors = bvm->bi_size >> 9;
5cf00fcd 696 struct geom *geo = &conf->geo;
1da177e4 697
3ea7daa5 698 chunk_sectors = (conf->geo.chunk_mask & conf->prev.chunk_mask) + 1;
f8c9e74f
N
699 if (conf->reshape_progress != MaxSector &&
700 ((sector >= conf->reshape_progress) !=
701 conf->mddev->reshape_backwards))
702 geo = &conf->prev;
703
5cf00fcd 704 if (geo->near_copies < geo->raid_disks) {
050b6615
N
705 max = (chunk_sectors - ((sector & (chunk_sectors - 1))
706 + bio_sectors)) << 9;
707 if (max < 0)
708 /* bio_add cannot handle a negative return */
709 max = 0;
710 if (max <= biovec->bv_len && bio_sectors == 0)
711 return biovec->bv_len;
712 } else
713 max = biovec->bv_len;
714
715 if (mddev->merge_check_needed) {
e0ee7785
N
716 struct {
717 struct r10bio r10_bio;
718 struct r10dev devs[conf->copies];
719 } on_stack;
720 struct r10bio *r10_bio = &on_stack.r10_bio;
050b6615 721 int s;
f8c9e74f
N
722 if (conf->reshape_progress != MaxSector) {
723 /* Cannot give any guidance during reshape */
724 if (max <= biovec->bv_len && bio_sectors == 0)
725 return biovec->bv_len;
726 return 0;
727 }
e0ee7785
N
728 r10_bio->sector = sector;
729 raid10_find_phys(conf, r10_bio);
050b6615
N
730 rcu_read_lock();
731 for (s = 0; s < conf->copies; s++) {
e0ee7785 732 int disk = r10_bio->devs[s].devnum;
050b6615
N
733 struct md_rdev *rdev = rcu_dereference(
734 conf->mirrors[disk].rdev);
735 if (rdev && !test_bit(Faulty, &rdev->flags)) {
736 struct request_queue *q =
737 bdev_get_queue(rdev->bdev);
738 if (q->merge_bvec_fn) {
e0ee7785 739 bvm->bi_sector = r10_bio->devs[s].addr
050b6615
N
740 + rdev->data_offset;
741 bvm->bi_bdev = rdev->bdev;
742 max = min(max, q->merge_bvec_fn(
743 q, bvm, biovec));
744 }
745 }
746 rdev = rcu_dereference(conf->mirrors[disk].replacement);
747 if (rdev && !test_bit(Faulty, &rdev->flags)) {
748 struct request_queue *q =
749 bdev_get_queue(rdev->bdev);
750 if (q->merge_bvec_fn) {
e0ee7785 751 bvm->bi_sector = r10_bio->devs[s].addr
050b6615
N
752 + rdev->data_offset;
753 bvm->bi_bdev = rdev->bdev;
754 max = min(max, q->merge_bvec_fn(
755 q, bvm, biovec));
756 }
757 }
758 }
759 rcu_read_unlock();
760 }
761 return max;
1da177e4
LT
762}
763
764/*
765 * This routine returns the disk from which the requested read should
766 * be done. There is a per-array 'next expected sequential IO' sector
767 * number - if this matches on the next IO then we use the last disk.
768 * There is also a per-disk 'last know head position' sector that is
769 * maintained from IRQ contexts, both the normal and the resync IO
770 * completion handlers update this position correctly. If there is no
771 * perfect sequential match then we pick the disk whose head is closest.
772 *
773 * If there are 2 mirrors in the same 2 devices, performance degrades
774 * because position is mirror, not device based.
775 *
776 * The rdev for the device selected will have nr_pending incremented.
777 */
778
779/*
780 * FIXME: possibly should rethink readbalancing and do it differently
781 * depending on near_copies / far_copies geometry.
782 */
96c3fd1f
N
783static struct md_rdev *read_balance(struct r10conf *conf,
784 struct r10bio *r10_bio,
785 int *max_sectors)
1da177e4 786{
af3a2cd6 787 const sector_t this_sector = r10_bio->sector;
56d99121 788 int disk, slot;
856e08e2
N
789 int sectors = r10_bio->sectors;
790 int best_good_sectors;
56d99121 791 sector_t new_distance, best_dist;
3bbae04b 792 struct md_rdev *best_rdev, *rdev = NULL;
56d99121
N
793 int do_balance;
794 int best_slot;
5cf00fcd 795 struct geom *geo = &conf->geo;
1da177e4
LT
796
797 raid10_find_phys(conf, r10_bio);
798 rcu_read_lock();
56d99121 799retry:
856e08e2 800 sectors = r10_bio->sectors;
56d99121 801 best_slot = -1;
abbf098e 802 best_rdev = NULL;
56d99121 803 best_dist = MaxSector;
856e08e2 804 best_good_sectors = 0;
56d99121 805 do_balance = 1;
1da177e4
LT
806 /*
807 * Check if we can balance. We can balance on the whole
6cce3b23
N
808 * device if no resync is going on (recovery is ok), or below
809 * the resync window. We take the first readable disk when
810 * above the resync window.
1da177e4
LT
811 */
812 if (conf->mddev->recovery_cp < MaxSector
56d99121
N
813 && (this_sector + sectors >= conf->next_resync))
814 do_balance = 0;
1da177e4 815
56d99121 816 for (slot = 0; slot < conf->copies ; slot++) {
856e08e2
N
817 sector_t first_bad;
818 int bad_sectors;
819 sector_t dev_sector;
820
56d99121
N
821 if (r10_bio->devs[slot].bio == IO_BLOCKED)
822 continue;
1da177e4 823 disk = r10_bio->devs[slot].devnum;
abbf098e
N
824 rdev = rcu_dereference(conf->mirrors[disk].replacement);
825 if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
050b6615 826 test_bit(Unmerged, &rdev->flags) ||
abbf098e
N
827 r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
828 rdev = rcu_dereference(conf->mirrors[disk].rdev);
050b6615
N
829 if (rdev == NULL ||
830 test_bit(Faulty, &rdev->flags) ||
831 test_bit(Unmerged, &rdev->flags))
abbf098e
N
832 continue;
833 if (!test_bit(In_sync, &rdev->flags) &&
834 r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
56d99121
N
835 continue;
836
856e08e2
N
837 dev_sector = r10_bio->devs[slot].addr;
838 if (is_badblock(rdev, dev_sector, sectors,
839 &first_bad, &bad_sectors)) {
840 if (best_dist < MaxSector)
841 /* Already have a better slot */
842 continue;
843 if (first_bad <= dev_sector) {
844 /* Cannot read here. If this is the
845 * 'primary' device, then we must not read
846 * beyond 'bad_sectors' from another device.
847 */
848 bad_sectors -= (dev_sector - first_bad);
849 if (!do_balance && sectors > bad_sectors)
850 sectors = bad_sectors;
851 if (best_good_sectors > sectors)
852 best_good_sectors = sectors;
853 } else {
854 sector_t good_sectors =
855 first_bad - dev_sector;
856 if (good_sectors > best_good_sectors) {
857 best_good_sectors = good_sectors;
858 best_slot = slot;
abbf098e 859 best_rdev = rdev;
856e08e2
N
860 }
861 if (!do_balance)
862 /* Must read from here */
863 break;
864 }
865 continue;
866 } else
867 best_good_sectors = sectors;
868
56d99121
N
869 if (!do_balance)
870 break;
1da177e4 871
22dfdf52
N
872 /* This optimisation is debatable, and completely destroys
873 * sequential read speed for 'far copies' arrays. So only
874 * keep it for 'near' arrays, and review those later.
875 */
5cf00fcd 876 if (geo->near_copies > 1 && !atomic_read(&rdev->nr_pending))
1da177e4 877 break;
8ed3a195
KS
878
879 /* for far > 1 always use the lowest address */
5cf00fcd 880 if (geo->far_copies > 1)
56d99121 881 new_distance = r10_bio->devs[slot].addr;
8ed3a195 882 else
56d99121
N
883 new_distance = abs(r10_bio->devs[slot].addr -
884 conf->mirrors[disk].head_position);
885 if (new_distance < best_dist) {
886 best_dist = new_distance;
887 best_slot = slot;
abbf098e 888 best_rdev = rdev;
1da177e4
LT
889 }
890 }
abbf098e 891 if (slot >= conf->copies) {
56d99121 892 slot = best_slot;
abbf098e
N
893 rdev = best_rdev;
894 }
1da177e4 895
56d99121 896 if (slot >= 0) {
56d99121
N
897 atomic_inc(&rdev->nr_pending);
898 if (test_bit(Faulty, &rdev->flags)) {
899 /* Cannot risk returning a device that failed
900 * before we inc'ed nr_pending
901 */
902 rdev_dec_pending(rdev, conf->mddev);
903 goto retry;
904 }
905 r10_bio->read_slot = slot;
906 } else
96c3fd1f 907 rdev = NULL;
1da177e4 908 rcu_read_unlock();
856e08e2 909 *max_sectors = best_good_sectors;
1da177e4 910
96c3fd1f 911 return rdev;
1da177e4
LT
912}
913
cc4d1efd 914int md_raid10_congested(struct mddev *mddev, int bits)
0d129228 915{
e879a879 916 struct r10conf *conf = mddev->private;
0d129228
N
917 int i, ret = 0;
918
34db0cd6
N
919 if ((bits & (1 << BDI_async_congested)) &&
920 conf->pending_count >= max_queued_requests)
921 return 1;
922
0d129228 923 rcu_read_lock();
f8c9e74f
N
924 for (i = 0;
925 (i < conf->geo.raid_disks || i < conf->prev.raid_disks)
926 && ret == 0;
927 i++) {
3cb03002 928 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
0d129228 929 if (rdev && !test_bit(Faulty, &rdev->flags)) {
165125e1 930 struct request_queue *q = bdev_get_queue(rdev->bdev);
0d129228
N
931
932 ret |= bdi_congested(&q->backing_dev_info, bits);
933 }
934 }
935 rcu_read_unlock();
936 return ret;
937}
cc4d1efd
JB
938EXPORT_SYMBOL_GPL(md_raid10_congested);
939
940static int raid10_congested(void *data, int bits)
941{
942 struct mddev *mddev = data;
943
944 return mddev_congested(mddev, bits) ||
945 md_raid10_congested(mddev, bits);
946}
0d129228 947
e879a879 948static void flush_pending_writes(struct r10conf *conf)
a35e63ef
N
949{
950 /* Any writes that have been queued but are awaiting
951 * bitmap updates get flushed here.
a35e63ef 952 */
a35e63ef
N
953 spin_lock_irq(&conf->device_lock);
954
955 if (conf->pending_bio_list.head) {
956 struct bio *bio;
957 bio = bio_list_get(&conf->pending_bio_list);
34db0cd6 958 conf->pending_count = 0;
a35e63ef
N
959 spin_unlock_irq(&conf->device_lock);
960 /* flush any pending bitmap writes to disk
961 * before proceeding w/ I/O */
962 bitmap_unplug(conf->mddev->bitmap);
34db0cd6 963 wake_up(&conf->wait_barrier);
a35e63ef
N
964
965 while (bio) { /* submit pending writes */
966 struct bio *next = bio->bi_next;
967 bio->bi_next = NULL;
532a2a3f
SL
968 if (unlikely((bio->bi_rw & REQ_DISCARD) &&
969 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
970 /* Just ignore it */
971 bio_endio(bio, 0);
972 else
973 generic_make_request(bio);
a35e63ef
N
974 bio = next;
975 }
a35e63ef
N
976 } else
977 spin_unlock_irq(&conf->device_lock);
a35e63ef 978}
7eaceacc 979
0a27ec96
N
980/* Barriers....
981 * Sometimes we need to suspend IO while we do something else,
982 * either some resync/recovery, or reconfigure the array.
983 * To do this we raise a 'barrier'.
984 * The 'barrier' is a counter that can be raised multiple times
985 * to count how many activities are happening which preclude
986 * normal IO.
987 * We can only raise the barrier if there is no pending IO.
988 * i.e. if nr_pending == 0.
989 * We choose only to raise the barrier if no-one is waiting for the
990 * barrier to go down. This means that as soon as an IO request
991 * is ready, no other operations which require a barrier will start
992 * until the IO request has had a chance.
993 *
994 * So: regular IO calls 'wait_barrier'. When that returns there
995 * is no backgroup IO happening, It must arrange to call
996 * allow_barrier when it has finished its IO.
997 * backgroup IO calls must call raise_barrier. Once that returns
998 * there is no normal IO happeing. It must arrange to call
999 * lower_barrier when the particular background IO completes.
1da177e4 1000 */
1da177e4 1001
e879a879 1002static void raise_barrier(struct r10conf *conf, int force)
1da177e4 1003{
6cce3b23 1004 BUG_ON(force && !conf->barrier);
1da177e4 1005 spin_lock_irq(&conf->resync_lock);
0a27ec96 1006
6cce3b23
N
1007 /* Wait until no block IO is waiting (unless 'force') */
1008 wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
eed8c02e 1009 conf->resync_lock);
0a27ec96
N
1010
1011 /* block any new IO from starting */
1012 conf->barrier++;
1013
c3b328ac 1014 /* Now wait for all pending IO to complete */
0a27ec96
N
1015 wait_event_lock_irq(conf->wait_barrier,
1016 !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
eed8c02e 1017 conf->resync_lock);
0a27ec96
N
1018
1019 spin_unlock_irq(&conf->resync_lock);
1020}
1021
e879a879 1022static void lower_barrier(struct r10conf *conf)
0a27ec96
N
1023{
1024 unsigned long flags;
1025 spin_lock_irqsave(&conf->resync_lock, flags);
1026 conf->barrier--;
1027 spin_unlock_irqrestore(&conf->resync_lock, flags);
1028 wake_up(&conf->wait_barrier);
1029}
1030
e879a879 1031static void wait_barrier(struct r10conf *conf)
0a27ec96
N
1032{
1033 spin_lock_irq(&conf->resync_lock);
1034 if (conf->barrier) {
1035 conf->nr_waiting++;
d6b42dcb
N
1036 /* Wait for the barrier to drop.
1037 * However if there are already pending
1038 * requests (preventing the barrier from
1039 * rising completely), and the
1040 * pre-process bio queue isn't empty,
1041 * then don't wait, as we need to empty
1042 * that queue to get the nr_pending
1043 * count down.
1044 */
1045 wait_event_lock_irq(conf->wait_barrier,
1046 !conf->barrier ||
1047 (conf->nr_pending &&
1048 current->bio_list &&
1049 !bio_list_empty(current->bio_list)),
eed8c02e 1050 conf->resync_lock);
0a27ec96 1051 conf->nr_waiting--;
1da177e4 1052 }
0a27ec96 1053 conf->nr_pending++;
1da177e4
LT
1054 spin_unlock_irq(&conf->resync_lock);
1055}
1056
e879a879 1057static void allow_barrier(struct r10conf *conf)
0a27ec96
N
1058{
1059 unsigned long flags;
1060 spin_lock_irqsave(&conf->resync_lock, flags);
1061 conf->nr_pending--;
1062 spin_unlock_irqrestore(&conf->resync_lock, flags);
1063 wake_up(&conf->wait_barrier);
1064}
1065
e2d59925 1066static void freeze_array(struct r10conf *conf, int extra)
4443ae10
N
1067{
1068 /* stop syncio and normal IO and wait for everything to
f188593e 1069 * go quiet.
4443ae10 1070 * We increment barrier and nr_waiting, and then
e2d59925 1071 * wait until nr_pending match nr_queued+extra
1c830532
N
1072 * This is called in the context of one normal IO request
1073 * that has failed. Thus any sync request that might be pending
1074 * will be blocked by nr_pending, and we need to wait for
1075 * pending IO requests to complete or be queued for re-try.
e2d59925 1076 * Thus the number queued (nr_queued) plus this request (extra)
1c830532
N
1077 * must match the number of pending IOs (nr_pending) before
1078 * we continue.
4443ae10
N
1079 */
1080 spin_lock_irq(&conf->resync_lock);
1081 conf->barrier++;
1082 conf->nr_waiting++;
eed8c02e 1083 wait_event_lock_irq_cmd(conf->wait_barrier,
e2d59925 1084 conf->nr_pending == conf->nr_queued+extra,
eed8c02e
LC
1085 conf->resync_lock,
1086 flush_pending_writes(conf));
c3b328ac 1087
4443ae10
N
1088 spin_unlock_irq(&conf->resync_lock);
1089}
1090
e879a879 1091static void unfreeze_array(struct r10conf *conf)
4443ae10
N
1092{
1093 /* reverse the effect of the freeze */
1094 spin_lock_irq(&conf->resync_lock);
1095 conf->barrier--;
1096 conf->nr_waiting--;
1097 wake_up(&conf->wait_barrier);
1098 spin_unlock_irq(&conf->resync_lock);
1099}
1100
f8c9e74f
N
1101static sector_t choose_data_offset(struct r10bio *r10_bio,
1102 struct md_rdev *rdev)
1103{
1104 if (!test_bit(MD_RECOVERY_RESHAPE, &rdev->mddev->recovery) ||
1105 test_bit(R10BIO_Previous, &r10_bio->state))
1106 return rdev->data_offset;
1107 else
1108 return rdev->new_data_offset;
1109}
1110
57c67df4
N
1111struct raid10_plug_cb {
1112 struct blk_plug_cb cb;
1113 struct bio_list pending;
1114 int pending_cnt;
1115};
1116
1117static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
1118{
1119 struct raid10_plug_cb *plug = container_of(cb, struct raid10_plug_cb,
1120 cb);
1121 struct mddev *mddev = plug->cb.data;
1122 struct r10conf *conf = mddev->private;
1123 struct bio *bio;
1124
874807a8 1125 if (from_schedule || current->bio_list) {
57c67df4
N
1126 spin_lock_irq(&conf->device_lock);
1127 bio_list_merge(&conf->pending_bio_list, &plug->pending);
1128 conf->pending_count += plug->pending_cnt;
1129 spin_unlock_irq(&conf->device_lock);
ee0b0244 1130 wake_up(&conf->wait_barrier);
57c67df4
N
1131 md_wakeup_thread(mddev->thread);
1132 kfree(plug);
1133 return;
1134 }
1135
1136 /* we aren't scheduling, so we can do the write-out directly. */
1137 bio = bio_list_get(&plug->pending);
1138 bitmap_unplug(mddev->bitmap);
1139 wake_up(&conf->wait_barrier);
1140
1141 while (bio) { /* submit pending writes */
1142 struct bio *next = bio->bi_next;
1143 bio->bi_next = NULL;
32f9f570
SL
1144 if (unlikely((bio->bi_rw & REQ_DISCARD) &&
1145 !blk_queue_discard(bdev_get_queue(bio->bi_bdev))))
1146 /* Just ignore it */
1147 bio_endio(bio, 0);
1148 else
1149 generic_make_request(bio);
57c67df4
N
1150 bio = next;
1151 }
1152 kfree(plug);
1153}
1154
b4fdcb02 1155static void make_request(struct mddev *mddev, struct bio * bio)
1da177e4 1156{
e879a879 1157 struct r10conf *conf = mddev->private;
9f2c9d12 1158 struct r10bio *r10_bio;
1da177e4
LT
1159 struct bio *read_bio;
1160 int i;
f8c9e74f 1161 sector_t chunk_mask = (conf->geo.chunk_mask & conf->prev.chunk_mask);
5cf00fcd 1162 int chunk_sects = chunk_mask + 1;
a362357b 1163 const int rw = bio_data_dir(bio);
2c7d46ec 1164 const unsigned long do_sync = (bio->bi_rw & REQ_SYNC);
e9c7469b 1165 const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
532a2a3f
SL
1166 const unsigned long do_discard = (bio->bi_rw
1167 & (REQ_DISCARD | REQ_SECURE));
c8dc9c65 1168 const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
6cce3b23 1169 unsigned long flags;
3cb03002 1170 struct md_rdev *blocked_rdev;
57c67df4
N
1171 struct blk_plug_cb *cb;
1172 struct raid10_plug_cb *plug = NULL;
d4432c23
N
1173 int sectors_handled;
1174 int max_sectors;
3ea7daa5 1175 int sectors;
1da177e4 1176
e9c7469b
TH
1177 if (unlikely(bio->bi_rw & REQ_FLUSH)) {
1178 md_flush_request(mddev, bio);
5a7bbad2 1179 return;
e5dcdd80
N
1180 }
1181
1da177e4
LT
1182 /* If this request crosses a chunk boundary, we need to
1183 * split it. This will only happen for 1 PAGE (or less) requests.
1184 */
aa8b57aa 1185 if (unlikely((bio->bi_sector & chunk_mask) + bio_sectors(bio)
5cf00fcd 1186 > chunk_sects
f8c9e74f
N
1187 && (conf->geo.near_copies < conf->geo.raid_disks
1188 || conf->prev.near_copies < conf->prev.raid_disks))) {
1da177e4
LT
1189 struct bio_pair *bp;
1190 /* Sanity check -- queue functions should prevent this happening */
5b83636a 1191 if (bio_segments(bio) > 1)
1da177e4
LT
1192 goto bad_map;
1193 /* This is a one page bio that upper layers
1194 * refuse to split for us, so we need to split it.
1195 */
6feef531 1196 bp = bio_split(bio,
1da177e4 1197 chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
51e9ac77
N
1198
1199 /* Each of these 'make_request' calls will call 'wait_barrier'.
1200 * If the first succeeds but the second blocks due to the resync
1201 * thread raising the barrier, we will deadlock because the
1202 * IO to the underlying device will be queued in generic_make_request
1203 * and will never complete, so will never reduce nr_pending.
1204 * So increment nr_waiting here so no new raise_barriers will
1205 * succeed, and so the second wait_barrier cannot block.
1206 */
1207 spin_lock_irq(&conf->resync_lock);
1208 conf->nr_waiting++;
1209 spin_unlock_irq(&conf->resync_lock);
1210
5a7bbad2
CH
1211 make_request(mddev, &bp->bio1);
1212 make_request(mddev, &bp->bio2);
1da177e4 1213
51e9ac77
N
1214 spin_lock_irq(&conf->resync_lock);
1215 conf->nr_waiting--;
1216 wake_up(&conf->wait_barrier);
1217 spin_unlock_irq(&conf->resync_lock);
1218
1da177e4 1219 bio_pair_release(bp);
5a7bbad2 1220 return;
1da177e4 1221 bad_map:
128595ed
N
1222 printk("md/raid10:%s: make_request bug: can't convert block across chunks"
1223 " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2,
aa8b57aa 1224 (unsigned long long)bio->bi_sector, bio_sectors(bio) / 2);
1da177e4 1225
6712ecf8 1226 bio_io_error(bio);
5a7bbad2 1227 return;
1da177e4
LT
1228 }
1229
3d310eb7 1230 md_write_start(mddev, bio);
06d91a5f 1231
1da177e4
LT
1232 /*
1233 * Register the new request and wait if the reconstruction
1234 * thread has put up a bar for new requests.
1235 * Continue immediately if no resync is active currently.
1236 */
0a27ec96 1237 wait_barrier(conf);
1da177e4 1238
aa8b57aa 1239 sectors = bio_sectors(bio);
3ea7daa5
N
1240 while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
1241 bio->bi_sector < conf->reshape_progress &&
1242 bio->bi_sector + sectors > conf->reshape_progress) {
1243 /* IO spans the reshape position. Need to wait for
1244 * reshape to pass
1245 */
1246 allow_barrier(conf);
1247 wait_event(conf->wait_barrier,
1248 conf->reshape_progress <= bio->bi_sector ||
1249 conf->reshape_progress >= bio->bi_sector + sectors);
1250 wait_barrier(conf);
1251 }
1252 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
1253 bio_data_dir(bio) == WRITE &&
1254 (mddev->reshape_backwards
1255 ? (bio->bi_sector < conf->reshape_safe &&
1256 bio->bi_sector + sectors > conf->reshape_progress)
1257 : (bio->bi_sector + sectors > conf->reshape_safe &&
1258 bio->bi_sector < conf->reshape_progress))) {
1259 /* Need to update reshape_position in metadata */
1260 mddev->reshape_position = conf->reshape_progress;
1261 set_bit(MD_CHANGE_DEVS, &mddev->flags);
1262 set_bit(MD_CHANGE_PENDING, &mddev->flags);
1263 md_wakeup_thread(mddev->thread);
1264 wait_event(mddev->sb_wait,
1265 !test_bit(MD_CHANGE_PENDING, &mddev->flags));
1266
1267 conf->reshape_safe = mddev->reshape_position;
1268 }
1269
1da177e4
LT
1270 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1271
1272 r10_bio->master_bio = bio;
3ea7daa5 1273 r10_bio->sectors = sectors;
1da177e4
LT
1274
1275 r10_bio->mddev = mddev;
1276 r10_bio->sector = bio->bi_sector;
6cce3b23 1277 r10_bio->state = 0;
1da177e4 1278
856e08e2
N
1279 /* We might need to issue multiple reads to different
1280 * devices if there are bad blocks around, so we keep
1281 * track of the number of reads in bio->bi_phys_segments.
1282 * If this is 0, there is only one r10_bio and no locking
1283 * will be needed when the request completes. If it is
1284 * non-zero, then it is the number of not-completed requests.
1285 */
1286 bio->bi_phys_segments = 0;
1287 clear_bit(BIO_SEG_VALID, &bio->bi_flags);
1288
a362357b 1289 if (rw == READ) {
1da177e4
LT
1290 /*
1291 * read balancing logic:
1292 */
96c3fd1f 1293 struct md_rdev *rdev;
856e08e2
N
1294 int slot;
1295
1296read_again:
96c3fd1f
N
1297 rdev = read_balance(conf, r10_bio, &max_sectors);
1298 if (!rdev) {
1da177e4 1299 raid_end_bio_io(r10_bio);
5a7bbad2 1300 return;
1da177e4 1301 }
96c3fd1f 1302 slot = r10_bio->read_slot;
1da177e4 1303
a167f663 1304 read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev);
856e08e2
N
1305 md_trim_bio(read_bio, r10_bio->sector - bio->bi_sector,
1306 max_sectors);
1da177e4
LT
1307
1308 r10_bio->devs[slot].bio = read_bio;
abbf098e 1309 r10_bio->devs[slot].rdev = rdev;
1da177e4
LT
1310
1311 read_bio->bi_sector = r10_bio->devs[slot].addr +
f8c9e74f 1312 choose_data_offset(r10_bio, rdev);
96c3fd1f 1313 read_bio->bi_bdev = rdev->bdev;
1da177e4 1314 read_bio->bi_end_io = raid10_end_read_request;
7b6d91da 1315 read_bio->bi_rw = READ | do_sync;
1da177e4
LT
1316 read_bio->bi_private = r10_bio;
1317
856e08e2
N
1318 if (max_sectors < r10_bio->sectors) {
1319 /* Could not read all from this device, so we will
1320 * need another r10_bio.
1321 */
856e08e2
N
1322 sectors_handled = (r10_bio->sectors + max_sectors
1323 - bio->bi_sector);
1324 r10_bio->sectors = max_sectors;
1325 spin_lock_irq(&conf->device_lock);
1326 if (bio->bi_phys_segments == 0)
1327 bio->bi_phys_segments = 2;
1328 else
1329 bio->bi_phys_segments++;
1330 spin_unlock(&conf->device_lock);
1331 /* Cannot call generic_make_request directly
1332 * as that will be queued in __generic_make_request
1333 * and subsequent mempool_alloc might block
1334 * waiting for it. so hand bio over to raid10d.
1335 */
1336 reschedule_retry(r10_bio);
1337
1338 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1339
1340 r10_bio->master_bio = bio;
aa8b57aa 1341 r10_bio->sectors = bio_sectors(bio) - sectors_handled;
856e08e2
N
1342 r10_bio->state = 0;
1343 r10_bio->mddev = mddev;
1344 r10_bio->sector = bio->bi_sector + sectors_handled;
1345 goto read_again;
1346 } else
1347 generic_make_request(read_bio);
5a7bbad2 1348 return;
1da177e4
LT
1349 }
1350
1351 /*
1352 * WRITE:
1353 */
34db0cd6
N
1354 if (conf->pending_count >= max_queued_requests) {
1355 md_wakeup_thread(mddev->thread);
1356 wait_event(conf->wait_barrier,
1357 conf->pending_count < max_queued_requests);
1358 }
6bfe0b49 1359 /* first select target devices under rcu_lock and
1da177e4
LT
1360 * inc refcount on their rdev. Record them by setting
1361 * bios[x] to bio
d4432c23
N
1362 * If there are known/acknowledged bad blocks on any device
1363 * on which we have seen a write error, we want to avoid
1364 * writing to those blocks. This potentially requires several
1365 * writes to write around the bad blocks. Each set of writes
1366 * gets its own r10_bio with a set of bios attached. The number
1367 * of r10_bios is recored in bio->bi_phys_segments just as with
1368 * the read case.
1da177e4 1369 */
c3b328ac 1370
69335ef3 1371 r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
1da177e4 1372 raid10_find_phys(conf, r10_bio);
d4432c23 1373retry_write:
cb6969e8 1374 blocked_rdev = NULL;
1da177e4 1375 rcu_read_lock();
d4432c23
N
1376 max_sectors = r10_bio->sectors;
1377
1da177e4
LT
1378 for (i = 0; i < conf->copies; i++) {
1379 int d = r10_bio->devs[i].devnum;
3cb03002 1380 struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev);
475b0321
N
1381 struct md_rdev *rrdev = rcu_dereference(
1382 conf->mirrors[d].replacement);
4ca40c2c
N
1383 if (rdev == rrdev)
1384 rrdev = NULL;
6bfe0b49
DW
1385 if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
1386 atomic_inc(&rdev->nr_pending);
1387 blocked_rdev = rdev;
1388 break;
1389 }
475b0321
N
1390 if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
1391 atomic_inc(&rrdev->nr_pending);
1392 blocked_rdev = rrdev;
1393 break;
1394 }
e7c0c3fa
N
1395 if (rdev && (test_bit(Faulty, &rdev->flags)
1396 || test_bit(Unmerged, &rdev->flags)))
1397 rdev = NULL;
050b6615
N
1398 if (rrdev && (test_bit(Faulty, &rrdev->flags)
1399 || test_bit(Unmerged, &rrdev->flags)))
475b0321
N
1400 rrdev = NULL;
1401
d4432c23 1402 r10_bio->devs[i].bio = NULL;
475b0321 1403 r10_bio->devs[i].repl_bio = NULL;
e7c0c3fa
N
1404
1405 if (!rdev && !rrdev) {
6cce3b23 1406 set_bit(R10BIO_Degraded, &r10_bio->state);
d4432c23
N
1407 continue;
1408 }
e7c0c3fa 1409 if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
d4432c23
N
1410 sector_t first_bad;
1411 sector_t dev_sector = r10_bio->devs[i].addr;
1412 int bad_sectors;
1413 int is_bad;
1414
1415 is_bad = is_badblock(rdev, dev_sector,
1416 max_sectors,
1417 &first_bad, &bad_sectors);
1418 if (is_bad < 0) {
1419 /* Mustn't write here until the bad block
1420 * is acknowledged
1421 */
1422 atomic_inc(&rdev->nr_pending);
1423 set_bit(BlockedBadBlocks, &rdev->flags);
1424 blocked_rdev = rdev;
1425 break;
1426 }
1427 if (is_bad && first_bad <= dev_sector) {
1428 /* Cannot write here at all */
1429 bad_sectors -= (dev_sector - first_bad);
1430 if (bad_sectors < max_sectors)
1431 /* Mustn't write more than bad_sectors
1432 * to other devices yet
1433 */
1434 max_sectors = bad_sectors;
1435 /* We don't set R10BIO_Degraded as that
1436 * only applies if the disk is missing,
1437 * so it might be re-added, and we want to
1438 * know to recover this chunk.
1439 * In this case the device is here, and the
1440 * fact that this chunk is not in-sync is
1441 * recorded in the bad block log.
1442 */
1443 continue;
1444 }
1445 if (is_bad) {
1446 int good_sectors = first_bad - dev_sector;
1447 if (good_sectors < max_sectors)
1448 max_sectors = good_sectors;
1449 }
6cce3b23 1450 }
e7c0c3fa
N
1451 if (rdev) {
1452 r10_bio->devs[i].bio = bio;
1453 atomic_inc(&rdev->nr_pending);
1454 }
475b0321
N
1455 if (rrdev) {
1456 r10_bio->devs[i].repl_bio = bio;
1457 atomic_inc(&rrdev->nr_pending);
1458 }
1da177e4
LT
1459 }
1460 rcu_read_unlock();
1461
6bfe0b49
DW
1462 if (unlikely(blocked_rdev)) {
1463 /* Have to wait for this device to get unblocked, then retry */
1464 int j;
1465 int d;
1466
475b0321 1467 for (j = 0; j < i; j++) {
6bfe0b49
DW
1468 if (r10_bio->devs[j].bio) {
1469 d = r10_bio->devs[j].devnum;
1470 rdev_dec_pending(conf->mirrors[d].rdev, mddev);
1471 }
475b0321 1472 if (r10_bio->devs[j].repl_bio) {
4ca40c2c 1473 struct md_rdev *rdev;
475b0321 1474 d = r10_bio->devs[j].devnum;
4ca40c2c
N
1475 rdev = conf->mirrors[d].replacement;
1476 if (!rdev) {
1477 /* Race with remove_disk */
1478 smp_mb();
1479 rdev = conf->mirrors[d].rdev;
1480 }
1481 rdev_dec_pending(rdev, mddev);
475b0321
N
1482 }
1483 }
6bfe0b49
DW
1484 allow_barrier(conf);
1485 md_wait_for_blocked_rdev(blocked_rdev, mddev);
1486 wait_barrier(conf);
1487 goto retry_write;
1488 }
1489
d4432c23
N
1490 if (max_sectors < r10_bio->sectors) {
1491 /* We are splitting this into multiple parts, so
1492 * we need to prepare for allocating another r10_bio.
1493 */
1494 r10_bio->sectors = max_sectors;
1495 spin_lock_irq(&conf->device_lock);
1496 if (bio->bi_phys_segments == 0)
1497 bio->bi_phys_segments = 2;
1498 else
1499 bio->bi_phys_segments++;
1500 spin_unlock_irq(&conf->device_lock);
1501 }
1502 sectors_handled = r10_bio->sector + max_sectors - bio->bi_sector;
1503
4e78064f 1504 atomic_set(&r10_bio->remaining, 1);
d4432c23 1505 bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
06d91a5f 1506
1da177e4
LT
1507 for (i = 0; i < conf->copies; i++) {
1508 struct bio *mbio;
1509 int d = r10_bio->devs[i].devnum;
e7c0c3fa
N
1510 if (r10_bio->devs[i].bio) {
1511 struct md_rdev *rdev = conf->mirrors[d].rdev;
1512 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1513 md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
1514 max_sectors);
1515 r10_bio->devs[i].bio = mbio;
1516
1517 mbio->bi_sector = (r10_bio->devs[i].addr+
1518 choose_data_offset(r10_bio,
1519 rdev));
1520 mbio->bi_bdev = rdev->bdev;
1521 mbio->bi_end_io = raid10_end_write_request;
c8dc9c65
JL
1522 mbio->bi_rw =
1523 WRITE | do_sync | do_fua | do_discard | do_same;
e7c0c3fa
N
1524 mbio->bi_private = r10_bio;
1525
1526 atomic_inc(&r10_bio->remaining);
1527
1528 cb = blk_check_plugged(raid10_unplug, mddev,
1529 sizeof(*plug));
1530 if (cb)
1531 plug = container_of(cb, struct raid10_plug_cb,
1532 cb);
1533 else
1534 plug = NULL;
1535 spin_lock_irqsave(&conf->device_lock, flags);
1536 if (plug) {
1537 bio_list_add(&plug->pending, mbio);
1538 plug->pending_cnt++;
1539 } else {
1540 bio_list_add(&conf->pending_bio_list, mbio);
1541 conf->pending_count++;
1542 }
1543 spin_unlock_irqrestore(&conf->device_lock, flags);
1544 if (!plug)
1545 md_wakeup_thread(mddev->thread);
1546 }
57c67df4 1547
e7c0c3fa
N
1548 if (r10_bio->devs[i].repl_bio) {
1549 struct md_rdev *rdev = conf->mirrors[d].replacement;
1550 if (rdev == NULL) {
1551 /* Replacement just got moved to main 'rdev' */
1552 smp_mb();
1553 rdev = conf->mirrors[d].rdev;
1554 }
1555 mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
1556 md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
1557 max_sectors);
1558 r10_bio->devs[i].repl_bio = mbio;
1559
1560 mbio->bi_sector = (r10_bio->devs[i].addr +
1561 choose_data_offset(
1562 r10_bio, rdev));
1563 mbio->bi_bdev = rdev->bdev;
1564 mbio->bi_end_io = raid10_end_write_request;
c8dc9c65
JL
1565 mbio->bi_rw =
1566 WRITE | do_sync | do_fua | do_discard | do_same;
e7c0c3fa
N
1567 mbio->bi_private = r10_bio;
1568
1569 atomic_inc(&r10_bio->remaining);
1570 spin_lock_irqsave(&conf->device_lock, flags);
57c67df4
N
1571 bio_list_add(&conf->pending_bio_list, mbio);
1572 conf->pending_count++;
e7c0c3fa
N
1573 spin_unlock_irqrestore(&conf->device_lock, flags);
1574 if (!mddev_check_plugged(mddev))
1575 md_wakeup_thread(mddev->thread);
57c67df4 1576 }
1da177e4
LT
1577 }
1578
079fa166
N
1579 /* Don't remove the bias on 'remaining' (one_write_done) until
1580 * after checking if we need to go around again.
1581 */
a35e63ef 1582
aa8b57aa 1583 if (sectors_handled < bio_sectors(bio)) {
079fa166 1584 one_write_done(r10_bio);
5e570289 1585 /* We need another r10_bio. It has already been counted
d4432c23
N
1586 * in bio->bi_phys_segments.
1587 */
1588 r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
1589
1590 r10_bio->master_bio = bio;
aa8b57aa 1591 r10_bio->sectors = bio_sectors(bio) - sectors_handled;
d4432c23
N
1592
1593 r10_bio->mddev = mddev;
1594 r10_bio->sector = bio->bi_sector + sectors_handled;
1595 r10_bio->state = 0;
1596 goto retry_write;
1597 }
079fa166
N
1598 one_write_done(r10_bio);
1599
1600 /* In case raid10d snuck in to freeze_array */
1601 wake_up(&conf->wait_barrier);
1da177e4
LT
1602}
1603
fd01b88c 1604static void status(struct seq_file *seq, struct mddev *mddev)
1da177e4 1605{
e879a879 1606 struct r10conf *conf = mddev->private;
1da177e4
LT
1607 int i;
1608
5cf00fcd 1609 if (conf->geo.near_copies < conf->geo.raid_disks)
9d8f0363 1610 seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2);
5cf00fcd
N
1611 if (conf->geo.near_copies > 1)
1612 seq_printf(seq, " %d near-copies", conf->geo.near_copies);
1613 if (conf->geo.far_copies > 1) {
1614 if (conf->geo.far_offset)
1615 seq_printf(seq, " %d offset-copies", conf->geo.far_copies);
c93983bf 1616 else
5cf00fcd 1617 seq_printf(seq, " %d far-copies", conf->geo.far_copies);
c93983bf 1618 }
5cf00fcd
N
1619 seq_printf(seq, " [%d/%d] [", conf->geo.raid_disks,
1620 conf->geo.raid_disks - mddev->degraded);
1621 for (i = 0; i < conf->geo.raid_disks; i++)
1da177e4
LT
1622 seq_printf(seq, "%s",
1623 conf->mirrors[i].rdev &&
b2d444d7 1624 test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_");
1da177e4
LT
1625 seq_printf(seq, "]");
1626}
1627
700c7213
N
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 */
635f6416 1633static int _enough(struct r10conf *conf, int previous, int ignore)
700c7213
N
1634{
1635 int first = 0;
725d6e57 1636 int has_enough = 0;
635f6416
N
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 }
700c7213 1645
725d6e57 1646 rcu_read_lock();
700c7213
N
1647 do {
1648 int n = conf->copies;
1649 int cnt = 0;
80b48124 1650 int this = first;
700c7213 1651 while (n--) {
725d6e57
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))
700c7213 1656 cnt++;
635f6416 1657 this = (this+1) % disks;
700c7213
N
1658 }
1659 if (cnt == 0)
725d6e57 1660 goto out;
635f6416 1661 first = (first + ncopies) % disks;
700c7213 1662 } while (first != 0);
725d6e57
N
1663 has_enough = 1;
1664out:
1665 rcu_read_unlock();
1666 return has_enough;
700c7213
N
1667}
1668
f8c9e74f
N
1669static int enough(struct r10conf *conf, int ignore)
1670{
635f6416
N
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);
f8c9e74f
N
1678}
1679
fd01b88c 1680static void error(struct mddev *mddev, struct md_rdev *rdev)
1da177e4
LT
1681{
1682 char b[BDEVNAME_SIZE];
e879a879 1683 struct r10conf *conf = mddev->private;
635f6416 1684 unsigned long flags;
1da177e4
LT
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 */
635f6416 1692 spin_lock_irqsave(&conf->device_lock, flags);
b2d444d7 1693 if (test_bit(In_sync, &rdev->flags)
635f6416 1694 && !enough(conf, rdev->raid_disk)) {
1da177e4
LT
1695 /*
1696 * Don't fail the drive, just return an IO error.
1da177e4 1697 */
635f6416 1698 spin_unlock_irqrestore(&conf->device_lock, flags);
1da177e4 1699 return;
635f6416 1700 }
c04be0aa 1701 if (test_and_clear_bit(In_sync, &rdev->flags)) {
1da177e4 1702 mddev->degraded++;
635f6416 1703 /*
1da177e4
LT
1704 * if recovery is running, make sure it aborts.
1705 */
dfc70645 1706 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1da177e4 1707 }
de393cde 1708 set_bit(Blocked, &rdev->flags);
b2d444d7 1709 set_bit(Faulty, &rdev->flags);
850b2b42 1710 set_bit(MD_CHANGE_DEVS, &mddev->flags);
635f6416 1711 spin_unlock_irqrestore(&conf->device_lock, flags);
067032bc
JP
1712 printk(KERN_ALERT
1713 "md/raid10:%s: Disk failure on %s, disabling device.\n"
1714 "md/raid10:%s: Operation continuing on %d devices.\n",
128595ed 1715 mdname(mddev), bdevname(rdev->bdev, b),
5cf00fcd 1716 mdname(mddev), conf->geo.raid_disks - mddev->degraded);
1da177e4
LT
1717}
1718
e879a879 1719static void print_conf(struct r10conf *conf)
1da177e4
LT
1720{
1721 int i;
dc280d98 1722 struct raid10_info *tmp;
1da177e4 1723
128595ed 1724 printk(KERN_DEBUG "RAID10 conf printout:\n");
1da177e4 1725 if (!conf) {
128595ed 1726 printk(KERN_DEBUG "(!conf)\n");
1da177e4
LT
1727 return;
1728 }
5cf00fcd
N
1729 printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->geo.raid_disks - conf->mddev->degraded,
1730 conf->geo.raid_disks);
1da177e4 1731
5cf00fcd 1732 for (i = 0; i < conf->geo.raid_disks; i++) {
1da177e4
LT
1733 char b[BDEVNAME_SIZE];
1734 tmp = conf->mirrors + i;
1735 if (tmp->rdev)
128595ed 1736 printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n",
b2d444d7
N
1737 i, !test_bit(In_sync, &tmp->rdev->flags),
1738 !test_bit(Faulty, &tmp->rdev->flags),
1da177e4
LT
1739 bdevname(tmp->rdev->bdev,b));
1740 }
1741}
1742
e879a879 1743static void close_sync(struct r10conf *conf)
1da177e4 1744{
0a27ec96
N
1745 wait_barrier(conf);
1746 allow_barrier(conf);
1da177e4
LT
1747
1748 mempool_destroy(conf->r10buf_pool);
1749 conf->r10buf_pool = NULL;
1750}
1751
fd01b88c 1752static int raid10_spare_active(struct mddev *mddev)
1da177e4
LT
1753{
1754 int i;
e879a879 1755 struct r10conf *conf = mddev->private;
dc280d98 1756 struct raid10_info *tmp;
6b965620
N
1757 int count = 0;
1758 unsigned long flags;
1da177e4
LT
1759
1760 /*
1761 * Find all non-in_sync disks within the RAID10 configuration
1762 * and mark them in_sync
1763 */
5cf00fcd 1764 for (i = 0; i < conf->geo.raid_disks; i++) {
1da177e4 1765 tmp = conf->mirrors + i;
4ca40c2c
N
1766 if (tmp->replacement
1767 && tmp->replacement->recovery_offset == MaxSector
1768 && !test_bit(Faulty, &tmp->replacement->flags)
1769 && !test_and_set_bit(In_sync, &tmp->replacement->flags)) {
1770 /* Replacement has just become active */
1771 if (!tmp->rdev
1772 || !test_and_clear_bit(In_sync, &tmp->rdev->flags))
1773 count++;
1774 if (tmp->rdev) {
1775 /* Replaced device not technically faulty,
1776 * but we need to be sure it gets removed
1777 * and never re-added.
1778 */
1779 set_bit(Faulty, &tmp->rdev->flags);
1780 sysfs_notify_dirent_safe(
1781 tmp->rdev->sysfs_state);
1782 }
1783 sysfs_notify_dirent_safe(tmp->replacement->sysfs_state);
1784 } else if (tmp->rdev
1785 && !test_bit(Faulty, &tmp->rdev->flags)
1786 && !test_and_set_bit(In_sync, &tmp->rdev->flags)) {
6b965620 1787 count++;
2863b9eb 1788 sysfs_notify_dirent_safe(tmp->rdev->sysfs_state);
1da177e4
LT
1789 }
1790 }
6b965620
N
1791 spin_lock_irqsave(&conf->device_lock, flags);
1792 mddev->degraded -= count;
1793 spin_unlock_irqrestore(&conf->device_lock, flags);
1da177e4
LT
1794
1795 print_conf(conf);
6b965620 1796 return count;
1da177e4
LT
1797}
1798
1799
fd01b88c 1800static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
1da177e4 1801{
e879a879 1802 struct r10conf *conf = mddev->private;
199050ea 1803 int err = -EEXIST;
1da177e4 1804 int mirror;
6c2fce2e 1805 int first = 0;
5cf00fcd 1806 int last = conf->geo.raid_disks - 1;
050b6615 1807 struct request_queue *q = bdev_get_queue(rdev->bdev);
1da177e4
LT
1808
1809 if (mddev->recovery_cp < MaxSector)
1810 /* only hot-add to in-sync arrays, as recovery is
1811 * very different from resync
1812 */
199050ea 1813 return -EBUSY;
635f6416 1814 if (rdev->saved_raid_disk < 0 && !_enough(conf, 1, -1))
199050ea 1815 return -EINVAL;
1da177e4 1816
a53a6c85 1817 if (rdev->raid_disk >= 0)
6c2fce2e 1818 first = last = rdev->raid_disk;
1da177e4 1819
050b6615
N
1820 if (q->merge_bvec_fn) {
1821 set_bit(Unmerged, &rdev->flags);
1822 mddev->merge_check_needed = 1;
1823 }
1824
2c4193df 1825 if (rdev->saved_raid_disk >= first &&
6cce3b23
N
1826 conf->mirrors[rdev->saved_raid_disk].rdev == NULL)
1827 mirror = rdev->saved_raid_disk;
1828 else
6c2fce2e 1829 mirror = first;
2bb77736 1830 for ( ; mirror <= last ; mirror++) {
dc280d98 1831 struct raid10_info *p = &conf->mirrors[mirror];
2bb77736
N
1832 if (p->recovery_disabled == mddev->recovery_disabled)
1833 continue;
b7044d41
N
1834 if (p->rdev) {
1835 if (!test_bit(WantReplacement, &p->rdev->flags) ||
1836 p->replacement != NULL)
1837 continue;
1838 clear_bit(In_sync, &rdev->flags);
1839 set_bit(Replacement, &rdev->flags);
1840 rdev->raid_disk = mirror;
1841 err = 0;
9092c02d
JB
1842 if (mddev->gendisk)
1843 disk_stack_limits(mddev->gendisk, rdev->bdev,
1844 rdev->data_offset << 9);
b7044d41
N
1845 conf->fullsync = 1;
1846 rcu_assign_pointer(p->replacement, rdev);
1847 break;
1848 }
1da177e4 1849
9092c02d
JB
1850 if (mddev->gendisk)
1851 disk_stack_limits(mddev->gendisk, rdev->bdev,
1852 rdev->data_offset << 9);
1da177e4 1853
2bb77736 1854 p->head_position = 0;
d890fa2b 1855 p->recovery_disabled = mddev->recovery_disabled - 1;
2bb77736
N
1856 rdev->raid_disk = mirror;
1857 err = 0;
1858 if (rdev->saved_raid_disk != mirror)
1859 conf->fullsync = 1;
1860 rcu_assign_pointer(p->rdev, rdev);
1861 break;
1862 }
050b6615
N
1863 if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
1864 /* Some requests might not have seen this new
1865 * merge_bvec_fn. We must wait for them to complete
1866 * before merging the device fully.
1867 * First we make sure any code which has tested
1868 * our function has submitted the request, then
1869 * we wait for all outstanding requests to complete.
1870 */
1871 synchronize_sched();
e2d59925
N
1872 freeze_array(conf, 0);
1873 unfreeze_array(conf);
050b6615
N
1874 clear_bit(Unmerged, &rdev->flags);
1875 }
ac5e7113 1876 md_integrity_add_rdev(rdev, mddev);
ed30be07 1877 if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
532a2a3f
SL
1878 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
1879
1da177e4 1880 print_conf(conf);
199050ea 1881 return err;
1da177e4
LT
1882}
1883
b8321b68 1884static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
1da177e4 1885{
e879a879 1886 struct r10conf *conf = mddev->private;
1da177e4 1887 int err = 0;
b8321b68 1888 int number = rdev->raid_disk;
c8ab903e 1889 struct md_rdev **rdevp;
dc280d98 1890 struct raid10_info *p = conf->mirrors + number;
1da177e4
LT
1891
1892 print_conf(conf);
c8ab903e
N
1893 if (rdev == p->rdev)
1894 rdevp = &p->rdev;
1895 else if (rdev == p->replacement)
1896 rdevp = &p->replacement;
1897 else
1898 return 0;
1899
1900 if (test_bit(In_sync, &rdev->flags) ||
1901 atomic_read(&rdev->nr_pending)) {
1902 err = -EBUSY;
1903 goto abort;
1904 }
1905 /* Only remove faulty devices if recovery
1906 * is not possible.
1907 */
1908 if (!test_bit(Faulty, &rdev->flags) &&
1909 mddev->recovery_disabled != p->recovery_disabled &&
4ca40c2c 1910 (!p->replacement || p->replacement == rdev) &&
63aced61 1911 number < conf->geo.raid_disks &&
c8ab903e
N
1912 enough(conf, -1)) {
1913 err = -EBUSY;
1914 goto abort;
1da177e4 1915 }
c8ab903e
N
1916 *rdevp = NULL;
1917 synchronize_rcu();
1918 if (atomic_read(&rdev->nr_pending)) {
1919 /* lost the race, try later */
1920 err = -EBUSY;
1921 *rdevp = rdev;
1922 goto abort;
4ca40c2c
N
1923 } else if (p->replacement) {
1924 /* We must have just cleared 'rdev' */
1925 p->rdev = p->replacement;
1926 clear_bit(Replacement, &p->replacement->flags);
1927 smp_mb(); /* Make sure other CPUs may see both as identical
1928 * but will never see neither -- if they are careful.
1929 */
1930 p->replacement = NULL;
1931 clear_bit(WantReplacement, &rdev->flags);
1932 } else
1933 /* We might have just remove the Replacement as faulty
1934 * Clear the flag just in case
1935 */
1936 clear_bit(WantReplacement, &rdev->flags);
1937
c8ab903e
N
1938 err = md_integrity_register(mddev);
1939
1da177e4
LT
1940abort:
1941
1942 print_conf(conf);
1943 return err;
1944}
1945
1946
6712ecf8 1947static void end_sync_read(struct bio *bio, int error)
1da177e4 1948{
9f2c9d12 1949 struct r10bio *r10_bio = bio->bi_private;
e879a879 1950 struct r10conf *conf = r10_bio->mddev->private;
778ca018 1951 int d;
1da177e4 1952
3ea7daa5
N
1953 if (bio == r10_bio->master_bio) {
1954 /* this is a reshape read */
1955 d = r10_bio->read_slot; /* really the read dev */
1956 } else
1957 d = find_bio_disk(conf, r10_bio, bio, NULL, NULL);
0eb3ff12
N
1958
1959 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
1960 set_bit(R10BIO_Uptodate, &r10_bio->state);
e684e41d
N
1961 else
1962 /* The write handler will notice the lack of
1963 * R10BIO_Uptodate and record any errors etc
1964 */
4dbcdc75
N
1965 atomic_add(r10_bio->sectors,
1966 &conf->mirrors[d].rdev->corrected_errors);
1da177e4
LT
1967
1968 /* for reconstruct, we always reschedule after a read.
1969 * for resync, only after all reads
1970 */
73d5c38a 1971 rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev);
1da177e4
LT
1972 if (test_bit(R10BIO_IsRecover, &r10_bio->state) ||
1973 atomic_dec_and_test(&r10_bio->remaining)) {
1974 /* we have read all the blocks,
1975 * do the comparison in process context in raid10d
1976 */
1977 reschedule_retry(r10_bio);
1978 }
1da177e4
LT
1979}
1980
9f2c9d12 1981static void end_sync_request(struct r10bio *r10_bio)
1da177e4 1982{
fd01b88c 1983 struct mddev *mddev = r10_bio->mddev;
dfc70645 1984
1da177e4
LT
1985 while (atomic_dec_and_test(&r10_bio->remaining)) {
1986 if (r10_bio->master_bio == NULL) {
1987 /* the primary of several recovery bios */
73d5c38a 1988 sector_t s = r10_bio->sectors;
1a0b7cd8
N
1989 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
1990 test_bit(R10BIO_WriteError, &r10_bio->state))
749c55e9
N
1991 reschedule_retry(r10_bio);
1992 else
1993 put_buf(r10_bio);
73d5c38a 1994 md_done_sync(mddev, s, 1);
1da177e4
LT
1995 break;
1996 } else {
9f2c9d12 1997 struct r10bio *r10_bio2 = (struct r10bio *)r10_bio->master_bio;
1a0b7cd8
N
1998 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
1999 test_bit(R10BIO_WriteError, &r10_bio->state))
749c55e9
N
2000 reschedule_retry(r10_bio);
2001 else
2002 put_buf(r10_bio);
1da177e4
LT
2003 r10_bio = r10_bio2;
2004 }
2005 }
1da177e4
LT
2006}
2007
5e570289
N
2008static void end_sync_write(struct bio *bio, int error)
2009{
2010 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
9f2c9d12 2011 struct r10bio *r10_bio = bio->bi_private;
fd01b88c 2012 struct mddev *mddev = r10_bio->mddev;
e879a879 2013 struct r10conf *conf = mddev->private;
5e570289
N
2014 int d;
2015 sector_t first_bad;
2016 int bad_sectors;
2017 int slot;
9ad1aefc 2018 int repl;
4ca40c2c 2019 struct md_rdev *rdev = NULL;
5e570289 2020
9ad1aefc
N
2021 d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
2022 if (repl)
2023 rdev = conf->mirrors[d].replacement;
547414d1 2024 else
9ad1aefc 2025 rdev = conf->mirrors[d].rdev;
5e570289
N
2026
2027 if (!uptodate) {
9ad1aefc
N
2028 if (repl)
2029 md_error(mddev, rdev);
2030 else {
2031 set_bit(WriteErrorSeen, &rdev->flags);
b7044d41
N
2032 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2033 set_bit(MD_RECOVERY_NEEDED,
2034 &rdev->mddev->recovery);
9ad1aefc
N
2035 set_bit(R10BIO_WriteError, &r10_bio->state);
2036 }
2037 } else if (is_badblock(rdev,
5e570289
N
2038 r10_bio->devs[slot].addr,
2039 r10_bio->sectors,
2040 &first_bad, &bad_sectors))
2041 set_bit(R10BIO_MadeGood, &r10_bio->state);
2042
9ad1aefc 2043 rdev_dec_pending(rdev, mddev);
5e570289
N
2044
2045 end_sync_request(r10_bio);
2046}
2047
1da177e4
LT
2048/*
2049 * Note: sync and recover and handled very differently for raid10
2050 * This code is for resync.
2051 * For resync, we read through virtual addresses and read all blocks.
2052 * If there is any error, we schedule a write. The lowest numbered
2053 * drive is authoritative.
2054 * However requests come for physical address, so we need to map.
2055 * For every physical address there are raid_disks/copies virtual addresses,
2056 * which is always are least one, but is not necessarly an integer.
2057 * This means that a physical address can span multiple chunks, so we may
2058 * have to submit multiple io requests for a single sync request.
2059 */
2060/*
2061 * We check if all blocks are in-sync and only write to blocks that
2062 * aren't in sync
2063 */
9f2c9d12 2064static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
1da177e4 2065{
e879a879 2066 struct r10conf *conf = mddev->private;
1da177e4
LT
2067 int i, first;
2068 struct bio *tbio, *fbio;
f4380a91 2069 int vcnt;
1da177e4
LT
2070
2071 atomic_set(&r10_bio->remaining, 1);
2072
2073 /* find the first device with a block */
2074 for (i=0; i<conf->copies; i++)
2075 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags))
2076 break;
2077
2078 if (i == conf->copies)
2079 goto done;
2080
2081 first = i;
2082 fbio = r10_bio->devs[i].bio;
2083
f4380a91 2084 vcnt = (r10_bio->sectors + (PAGE_SIZE >> 9) - 1) >> (PAGE_SHIFT - 9);
1da177e4 2085 /* now find blocks with errors */
0eb3ff12
N
2086 for (i=0 ; i < conf->copies ; i++) {
2087 int j, d;
1da177e4 2088
1da177e4 2089 tbio = r10_bio->devs[i].bio;
0eb3ff12
N
2090
2091 if (tbio->bi_end_io != end_sync_read)
2092 continue;
2093 if (i == first)
1da177e4 2094 continue;
0eb3ff12
N
2095 if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) {
2096 /* We know that the bi_io_vec layout is the same for
2097 * both 'first' and 'i', so we just compare them.
2098 * All vec entries are PAGE_SIZE;
2099 */
7bb23c49
N
2100 int sectors = r10_bio->sectors;
2101 for (j = 0; j < vcnt; j++) {
2102 int len = PAGE_SIZE;
2103 if (sectors < (len / 512))
2104 len = sectors * 512;
0eb3ff12
N
2105 if (memcmp(page_address(fbio->bi_io_vec[j].bv_page),
2106 page_address(tbio->bi_io_vec[j].bv_page),
7bb23c49 2107 len))
0eb3ff12 2108 break;
7bb23c49
N
2109 sectors -= len/512;
2110 }
0eb3ff12
N
2111 if (j == vcnt)
2112 continue;
7f7583d4 2113 atomic64_add(r10_bio->sectors, &mddev->resync_mismatches);
f84ee364
N
2114 if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
2115 /* Don't fix anything. */
2116 continue;
0eb3ff12 2117 }
f84ee364
N
2118 /* Ok, we need to write this bio, either to correct an
2119 * inconsistency or to correct an unreadable block.
1da177e4
LT
2120 * First we need to fixup bv_offset, bv_len and
2121 * bi_vecs, as the read request might have corrupted these
2122 */
8be185f2
KO
2123 bio_reset(tbio);
2124
1da177e4
LT
2125 tbio->bi_vcnt = vcnt;
2126 tbio->bi_size = r10_bio->sectors << 9;
1da177e4
LT
2127 tbio->bi_rw = WRITE;
2128 tbio->bi_private = r10_bio;
2129 tbio->bi_sector = r10_bio->devs[i].addr;
2130
2131 for (j=0; j < vcnt ; j++) {
2132 tbio->bi_io_vec[j].bv_offset = 0;
2133 tbio->bi_io_vec[j].bv_len = PAGE_SIZE;
2134
2135 memcpy(page_address(tbio->bi_io_vec[j].bv_page),
2136 page_address(fbio->bi_io_vec[j].bv_page),
2137 PAGE_SIZE);
2138 }
2139 tbio->bi_end_io = end_sync_write;
2140
2141 d = r10_bio->devs[i].devnum;
2142 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
2143 atomic_inc(&r10_bio->remaining);
aa8b57aa 2144 md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(tbio));
1da177e4
LT
2145
2146 tbio->bi_sector += conf->mirrors[d].rdev->data_offset;
2147 tbio->bi_bdev = conf->mirrors[d].rdev->bdev;
2148 generic_make_request(tbio);
2149 }
2150
9ad1aefc
N
2151 /* Now write out to any replacement devices
2152 * that are active
2153 */
2154 for (i = 0; i < conf->copies; i++) {
2155 int j, d;
9ad1aefc
N
2156
2157 tbio = r10_bio->devs[i].repl_bio;
2158 if (!tbio || !tbio->bi_end_io)
2159 continue;
2160 if (r10_bio->devs[i].bio->bi_end_io != end_sync_write
2161 && r10_bio->devs[i].bio != fbio)
2162 for (j = 0; j < vcnt; j++)
2163 memcpy(page_address(tbio->bi_io_vec[j].bv_page),
2164 page_address(fbio->bi_io_vec[j].bv_page),
2165 PAGE_SIZE);
2166 d = r10_bio->devs[i].devnum;
2167 atomic_inc(&r10_bio->remaining);
2168 md_sync_acct(conf->mirrors[d].replacement->bdev,
aa8b57aa 2169 bio_sectors(tbio));
9ad1aefc
N
2170 generic_make_request(tbio);
2171 }
2172
1da177e4
LT
2173done:
2174 if (atomic_dec_and_test(&r10_bio->remaining)) {
2175 md_done_sync(mddev, r10_bio->sectors, 1);
2176 put_buf(r10_bio);
2177 }
2178}
2179
2180/*
2181 * Now for the recovery code.
2182 * Recovery happens across physical sectors.
2183 * We recover all non-is_sync drives by finding the virtual address of
2184 * each, and then choose a working drive that also has that virt address.
2185 * There is a separate r10_bio for each non-in_sync drive.
2186 * Only the first two slots are in use. The first for reading,
2187 * The second for writing.
2188 *
2189 */
9f2c9d12 2190static void fix_recovery_read_error(struct r10bio *r10_bio)
5e570289
N
2191{
2192 /* We got a read error during recovery.
2193 * We repeat the read in smaller page-sized sections.
2194 * If a read succeeds, write it to the new device or record
2195 * a bad block if we cannot.
2196 * If a read fails, record a bad block on both old and
2197 * new devices.
2198 */
fd01b88c 2199 struct mddev *mddev = r10_bio->mddev;
e879a879 2200 struct r10conf *conf = mddev->private;
5e570289
N
2201 struct bio *bio = r10_bio->devs[0].bio;
2202 sector_t sect = 0;
2203 int sectors = r10_bio->sectors;
2204 int idx = 0;
2205 int dr = r10_bio->devs[0].devnum;
2206 int dw = r10_bio->devs[1].devnum;
2207
2208 while (sectors) {
2209 int s = sectors;
3cb03002 2210 struct md_rdev *rdev;
5e570289
N
2211 sector_t addr;
2212 int ok;
2213
2214 if (s > (PAGE_SIZE>>9))
2215 s = PAGE_SIZE >> 9;
2216
2217 rdev = conf->mirrors[dr].rdev;
2218 addr = r10_bio->devs[0].addr + sect,
2219 ok = sync_page_io(rdev,
2220 addr,
2221 s << 9,
2222 bio->bi_io_vec[idx].bv_page,
2223 READ, false);
2224 if (ok) {
2225 rdev = conf->mirrors[dw].rdev;
2226 addr = r10_bio->devs[1].addr + sect;
2227 ok = sync_page_io(rdev,
2228 addr,
2229 s << 9,
2230 bio->bi_io_vec[idx].bv_page,
2231 WRITE, false);
b7044d41 2232 if (!ok) {
5e570289 2233 set_bit(WriteErrorSeen, &rdev->flags);
b7044d41
N
2234 if (!test_and_set_bit(WantReplacement,
2235 &rdev->flags))
2236 set_bit(MD_RECOVERY_NEEDED,
2237 &rdev->mddev->recovery);
2238 }
5e570289
N
2239 }
2240 if (!ok) {
2241 /* We don't worry if we cannot set a bad block -
2242 * it really is bad so there is no loss in not
2243 * recording it yet
2244 */
2245 rdev_set_badblocks(rdev, addr, s, 0);
2246
2247 if (rdev != conf->mirrors[dw].rdev) {
2248 /* need bad block on destination too */
3cb03002 2249 struct md_rdev *rdev2 = conf->mirrors[dw].rdev;
5e570289
N
2250 addr = r10_bio->devs[1].addr + sect;
2251 ok = rdev_set_badblocks(rdev2, addr, s, 0);
2252 if (!ok) {
2253 /* just abort the recovery */
2254 printk(KERN_NOTICE
2255 "md/raid10:%s: recovery aborted"
2256 " due to read error\n",
2257 mdname(mddev));
2258
2259 conf->mirrors[dw].recovery_disabled
2260 = mddev->recovery_disabled;
2261 set_bit(MD_RECOVERY_INTR,
2262 &mddev->recovery);
2263 break;
2264 }
2265 }
2266 }
2267
2268 sectors -= s;
2269 sect += s;
2270 idx++;
2271 }
2272}
1da177e4 2273
9f2c9d12 2274static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
1da177e4 2275{
e879a879 2276 struct r10conf *conf = mddev->private;
c65060ad 2277 int d;
24afd80d 2278 struct bio *wbio, *wbio2;
1da177e4 2279
5e570289
N
2280 if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
2281 fix_recovery_read_error(r10_bio);
2282 end_sync_request(r10_bio);
2283 return;
2284 }
2285
c65060ad
NK
2286 /*
2287 * share the pages with the first bio
1da177e4
LT
2288 * and submit the write request
2289 */
1da177e4 2290 d = r10_bio->devs[1].devnum;
24afd80d
N
2291 wbio = r10_bio->devs[1].bio;
2292 wbio2 = r10_bio->devs[1].repl_bio;
0eb25bb0
N
2293 /* Need to test wbio2->bi_end_io before we call
2294 * generic_make_request as if the former is NULL,
2295 * the latter is free to free wbio2.
2296 */
2297 if (wbio2 && !wbio2->bi_end_io)
2298 wbio2 = NULL;
24afd80d
N
2299 if (wbio->bi_end_io) {
2300 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
aa8b57aa 2301 md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(wbio));
24afd80d
N
2302 generic_make_request(wbio);
2303 }
0eb25bb0 2304 if (wbio2) {
24afd80d
N
2305 atomic_inc(&conf->mirrors[d].replacement->nr_pending);
2306 md_sync_acct(conf->mirrors[d].replacement->bdev,
aa8b57aa 2307 bio_sectors(wbio2));
24afd80d
N
2308 generic_make_request(wbio2);
2309 }
1da177e4
LT
2310}
2311
2312
1e50915f
RB
2313/*
2314 * Used by fix_read_error() to decay the per rdev read_errors.
2315 * We halve the read error count for every hour that has elapsed
2316 * since the last recorded read error.
2317 *
2318 */
fd01b88c 2319static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev)
1e50915f
RB
2320{
2321 struct timespec cur_time_mon;
2322 unsigned long hours_since_last;
2323 unsigned int read_errors = atomic_read(&rdev->read_errors);
2324
2325 ktime_get_ts(&cur_time_mon);
2326
2327 if (rdev->last_read_error.tv_sec == 0 &&
2328 rdev->last_read_error.tv_nsec == 0) {
2329 /* first time we've seen a read error */
2330 rdev->last_read_error = cur_time_mon;
2331 return;
2332 }
2333
2334 hours_since_last = (cur_time_mon.tv_sec -
2335 rdev->last_read_error.tv_sec) / 3600;
2336
2337 rdev->last_read_error = cur_time_mon;
2338
2339 /*
2340 * if hours_since_last is > the number of bits in read_errors
2341 * just set read errors to 0. We do this to avoid
2342 * overflowing the shift of read_errors by hours_since_last.
2343 */
2344 if (hours_since_last >= 8 * sizeof(read_errors))
2345 atomic_set(&rdev->read_errors, 0);
2346 else
2347 atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
2348}
2349
3cb03002 2350static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector,
58c54fcc
N
2351 int sectors, struct page *page, int rw)
2352{
2353 sector_t first_bad;
2354 int bad_sectors;
2355
2356 if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors)
2357 && (rw == READ || test_bit(WriteErrorSeen, &rdev->flags)))
2358 return -1;
2359 if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
2360 /* success */
2361 return 1;
b7044d41 2362 if (rw == WRITE) {
58c54fcc 2363 set_bit(WriteErrorSeen, &rdev->flags);
b7044d41
N
2364 if (!test_and_set_bit(WantReplacement, &rdev->flags))
2365 set_bit(MD_RECOVERY_NEEDED,
2366 &rdev->mddev->recovery);
2367 }
58c54fcc
N
2368 /* need to record an error - either for the block or the device */
2369 if (!rdev_set_badblocks(rdev, sector, sectors, 0))
2370 md_error(rdev->mddev, rdev);
2371 return 0;
2372}
2373
1da177e4
LT
2374/*
2375 * This is a kernel thread which:
2376 *
2377 * 1. Retries failed read operations on working mirrors.
2378 * 2. Updates the raid superblock when problems encounter.
6814d536 2379 * 3. Performs writes following reads for array synchronising.
1da177e4
LT
2380 */
2381
e879a879 2382static void fix_read_error(struct r10conf *conf, struct mddev *mddev, struct r10bio *r10_bio)
6814d536
N
2383{
2384 int sect = 0; /* Offset from r10_bio->sector */
2385 int sectors = r10_bio->sectors;
3cb03002 2386 struct md_rdev*rdev;
1e50915f 2387 int max_read_errors = atomic_read(&mddev->max_corr_read_errors);
0544a21d 2388 int d = r10_bio->devs[r10_bio->read_slot].devnum;
1e50915f 2389
7c4e06ff
N
2390 /* still own a reference to this rdev, so it cannot
2391 * have been cleared recently.
2392 */
2393 rdev = conf->mirrors[d].rdev;
1e50915f 2394
7c4e06ff
N
2395 if (test_bit(Faulty, &rdev->flags))
2396 /* drive has already been failed, just ignore any
2397 more fix_read_error() attempts */
2398 return;
1e50915f 2399
7c4e06ff
N
2400 check_decay_read_errors(mddev, rdev);
2401 atomic_inc(&rdev->read_errors);
2402 if (atomic_read(&rdev->read_errors) > max_read_errors) {
2403 char b[BDEVNAME_SIZE];
2404 bdevname(rdev->bdev, b);
1e50915f 2405
7c4e06ff
N
2406 printk(KERN_NOTICE
2407 "md/raid10:%s: %s: Raid device exceeded "
2408 "read_error threshold [cur %d:max %d]\n",
2409 mdname(mddev), b,
2410 atomic_read(&rdev->read_errors), max_read_errors);
2411 printk(KERN_NOTICE
2412 "md/raid10:%s: %s: Failing raid device\n",
2413 mdname(mddev), b);
2414 md_error(mddev, conf->mirrors[d].rdev);
fae8cc5e 2415 r10_bio->devs[r10_bio->read_slot].bio = IO_BLOCKED;
7c4e06ff 2416 return;
1e50915f 2417 }
1e50915f 2418
6814d536
N
2419 while(sectors) {
2420 int s = sectors;
2421 int sl = r10_bio->read_slot;
2422 int success = 0;
2423 int start;
2424
2425 if (s > (PAGE_SIZE>>9))
2426 s = PAGE_SIZE >> 9;
2427
2428 rcu_read_lock();
2429 do {
8dbed5ce
N
2430 sector_t first_bad;
2431 int bad_sectors;
2432
0544a21d 2433 d = r10_bio->devs[sl].devnum;
6814d536
N
2434 rdev = rcu_dereference(conf->mirrors[d].rdev);
2435 if (rdev &&
050b6615 2436 !test_bit(Unmerged, &rdev->flags) &&
8dbed5ce
N
2437 test_bit(In_sync, &rdev->flags) &&
2438 is_badblock(rdev, r10_bio->devs[sl].addr + sect, s,
2439 &first_bad, &bad_sectors) == 0) {
6814d536
N
2440 atomic_inc(&rdev->nr_pending);
2441 rcu_read_unlock();
2b193363 2442 success = sync_page_io(rdev,
6814d536 2443 r10_bio->devs[sl].addr +
ccebd4c4 2444 sect,
6814d536 2445 s<<9,
ccebd4c4 2446 conf->tmppage, READ, false);
6814d536
N
2447 rdev_dec_pending(rdev, mddev);
2448 rcu_read_lock();
2449 if (success)
2450 break;
2451 }
2452 sl++;
2453 if (sl == conf->copies)
2454 sl = 0;
2455 } while (!success && sl != r10_bio->read_slot);
2456 rcu_read_unlock();
2457
2458 if (!success) {
58c54fcc
N
2459 /* Cannot read from anywhere, just mark the block
2460 * as bad on the first device to discourage future
2461 * reads.
2462 */
6814d536 2463 int dn = r10_bio->devs[r10_bio->read_slot].devnum;
58c54fcc
N
2464 rdev = conf->mirrors[dn].rdev;
2465
2466 if (!rdev_set_badblocks(
2467 rdev,
2468 r10_bio->devs[r10_bio->read_slot].addr
2469 + sect,
fae8cc5e 2470 s, 0)) {
58c54fcc 2471 md_error(mddev, rdev);
fae8cc5e
N
2472 r10_bio->devs[r10_bio->read_slot].bio
2473 = IO_BLOCKED;
2474 }
6814d536
N
2475 break;
2476 }
2477
2478 start = sl;
2479 /* write it back and re-read */
2480 rcu_read_lock();
2481 while (sl != r10_bio->read_slot) {
67b8dc4b 2482 char b[BDEVNAME_SIZE];
0544a21d 2483
6814d536
N
2484 if (sl==0)
2485 sl = conf->copies;
2486 sl--;
2487 d = r10_bio->devs[sl].devnum;
2488 rdev = rcu_dereference(conf->mirrors[d].rdev);
1294b9c9 2489 if (!rdev ||
050b6615 2490 test_bit(Unmerged, &rdev->flags) ||
1294b9c9
N
2491 !test_bit(In_sync, &rdev->flags))
2492 continue;
2493
2494 atomic_inc(&rdev->nr_pending);
2495 rcu_read_unlock();
58c54fcc
N
2496 if (r10_sync_page_io(rdev,
2497 r10_bio->devs[sl].addr +
2498 sect,
055d3747 2499 s, conf->tmppage, WRITE)
1294b9c9
N
2500 == 0) {
2501 /* Well, this device is dead */
2502 printk(KERN_NOTICE
2503 "md/raid10:%s: read correction "
2504 "write failed"
2505 " (%d sectors at %llu on %s)\n",
2506 mdname(mddev), s,
2507 (unsigned long long)(
f8c9e74f
N
2508 sect +
2509 choose_data_offset(r10_bio,
2510 rdev)),
1294b9c9
N
2511 bdevname(rdev->bdev, b));
2512 printk(KERN_NOTICE "md/raid10:%s: %s: failing "
2513 "drive\n",
2514 mdname(mddev),
2515 bdevname(rdev->bdev, b));
6814d536 2516 }
1294b9c9
N
2517 rdev_dec_pending(rdev, mddev);
2518 rcu_read_lock();
6814d536
N
2519 }
2520 sl = start;
2521 while (sl != r10_bio->read_slot) {
1294b9c9 2522 char b[BDEVNAME_SIZE];
0544a21d 2523
6814d536
N
2524 if (sl==0)
2525 sl = conf->copies;
2526 sl--;
2527 d = r10_bio->devs[sl].devnum;
2528 rdev = rcu_dereference(conf->mirrors[d].rdev);
1294b9c9
N
2529 if (!rdev ||
2530 !test_bit(In_sync, &rdev->flags))
2531 continue;
6814d536 2532
1294b9c9
N
2533 atomic_inc(&rdev->nr_pending);
2534 rcu_read_unlock();
58c54fcc
N
2535 switch (r10_sync_page_io(rdev,
2536 r10_bio->devs[sl].addr +
2537 sect,
055d3747 2538 s, conf->tmppage,
58c54fcc
N
2539 READ)) {
2540 case 0:
1294b9c9
N
2541 /* Well, this device is dead */
2542 printk(KERN_NOTICE
2543 "md/raid10:%s: unable to read back "
2544 "corrected sectors"
2545 " (%d sectors at %llu on %s)\n",
2546 mdname(mddev), s,
2547 (unsigned long long)(
f8c9e74f
N
2548 sect +
2549 choose_data_offset(r10_bio, rdev)),
1294b9c9
N
2550 bdevname(rdev->bdev, b));
2551 printk(KERN_NOTICE "md/raid10:%s: %s: failing "
2552 "drive\n",
2553 mdname(mddev),
2554 bdevname(rdev->bdev, b));
58c54fcc
N
2555 break;
2556 case 1:
1294b9c9
N
2557 printk(KERN_INFO
2558 "md/raid10:%s: read error corrected"
2559 " (%d sectors at %llu on %s)\n",
2560 mdname(mddev), s,
2561 (unsigned long long)(
f8c9e74f
N
2562 sect +
2563 choose_data_offset(r10_bio, rdev)),
1294b9c9
N
2564 bdevname(rdev->bdev, b));
2565 atomic_add(s, &rdev->corrected_errors);
6814d536 2566 }
1294b9c9
N
2567
2568 rdev_dec_pending(rdev, mddev);
2569 rcu_read_lock();
6814d536
N
2570 }
2571 rcu_read_unlock();
2572
2573 sectors -= s;
2574 sect += s;
2575 }
2576}
2577
9f2c9d12 2578static int narrow_write_error(struct r10bio *r10_bio, int i)
bd870a16
N
2579{
2580 struct bio *bio = r10_bio->master_bio;
fd01b88c 2581 struct mddev *mddev = r10_bio->mddev;
e879a879 2582 struct r10conf *conf = mddev->private;
3cb03002 2583 struct md_rdev *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev;
bd870a16
N
2584 /* bio has the data to be written to slot 'i' where
2585 * we just recently had a write error.
2586 * We repeatedly clone the bio and trim down to one block,
2587 * then try the write. Where the write fails we record
2588 * a bad block.
2589 * It is conceivable that the bio doesn't exactly align with
2590 * blocks. We must handle this.
2591 *
2592 * We currently own a reference to the rdev.
2593 */
2594
2595 int block_sectors;
2596 sector_t sector;
2597 int sectors;
2598 int sect_to_write = r10_bio->sectors;
2599 int ok = 1;
2600
2601 if (rdev->badblocks.shift < 0)
2602 return 0;
2603
2604 block_sectors = 1 << rdev->badblocks.shift;
2605 sector = r10_bio->sector;
2606 sectors = ((r10_bio->sector + block_sectors)
2607 & ~(sector_t)(block_sectors - 1))
2608 - sector;
2609
2610 while (sect_to_write) {
2611 struct bio *wbio;
2612 if (sectors > sect_to_write)
2613 sectors = sect_to_write;
2614 /* Write at 'sector' for 'sectors' */
2615 wbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
2616 md_trim_bio(wbio, sector - bio->bi_sector, sectors);
2617 wbio->bi_sector = (r10_bio->devs[i].addr+
f8c9e74f 2618 choose_data_offset(r10_bio, rdev) +
bd870a16
N
2619 (sector - r10_bio->sector));
2620 wbio->bi_bdev = rdev->bdev;
2621 if (submit_bio_wait(WRITE, wbio) == 0)
2622 /* Failure! */
2623 ok = rdev_set_badblocks(rdev, sector,
2624 sectors, 0)
2625 && ok;
2626
2627 bio_put(wbio);
2628 sect_to_write -= sectors;
2629 sector += sectors;
2630 sectors = block_sectors;
2631 }
2632 return ok;
2633}
2634
9f2c9d12 2635static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
560f8e55
N
2636{
2637 int slot = r10_bio->read_slot;
560f8e55 2638 struct bio *bio;
e879a879 2639 struct r10conf *conf = mddev->private;
abbf098e 2640 struct md_rdev *rdev = r10_bio->devs[slot].rdev;
560f8e55
N
2641 char b[BDEVNAME_SIZE];
2642 unsigned long do_sync;
856e08e2 2643 int max_sectors;
560f8e55
N
2644
2645 /* we got a read error. Maybe the drive is bad. Maybe just
2646 * the block and we can fix it.
2647 * We freeze all other IO, and try reading the block from
2648 * other devices. When we find one, we re-write
2649 * and check it that fixes the read error.
2650 * This is all done synchronously while the array is
2651 * frozen.
2652 */
fae8cc5e
N
2653 bio = r10_bio->devs[slot].bio;
2654 bdevname(bio->bi_bdev, b);
2655 bio_put(bio);
2656 r10_bio->devs[slot].bio = NULL;
2657
560f8e55 2658 if (mddev->ro == 0) {
e2d59925 2659 freeze_array(conf, 1);
560f8e55
N
2660 fix_read_error(conf, mddev, r10_bio);
2661 unfreeze_array(conf);
fae8cc5e
N
2662 } else
2663 r10_bio->devs[slot].bio = IO_BLOCKED;
2664
abbf098e 2665 rdev_dec_pending(rdev, mddev);
560f8e55 2666
7399c31b 2667read_more:
96c3fd1f
N
2668 rdev = read_balance(conf, r10_bio, &max_sectors);
2669 if (rdev == NULL) {
560f8e55
N
2670 printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O"
2671 " read error for block %llu\n",
7399c31b 2672 mdname(mddev), b,
560f8e55
N
2673 (unsigned long long)r10_bio->sector);
2674 raid_end_bio_io(r10_bio);
560f8e55
N
2675 return;
2676 }
2677
2678 do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC);
560f8e55 2679 slot = r10_bio->read_slot;
560f8e55
N
2680 printk_ratelimited(
2681 KERN_ERR
055d3747 2682 "md/raid10:%s: %s: redirecting "
560f8e55
N
2683 "sector %llu to another mirror\n",
2684 mdname(mddev),
2685 bdevname(rdev->bdev, b),
2686 (unsigned long long)r10_bio->sector);
2687 bio = bio_clone_mddev(r10_bio->master_bio,
2688 GFP_NOIO, mddev);
7399c31b
N
2689 md_trim_bio(bio,
2690 r10_bio->sector - bio->bi_sector,
2691 max_sectors);
560f8e55 2692 r10_bio->devs[slot].bio = bio;
abbf098e 2693 r10_bio->devs[slot].rdev = rdev;
560f8e55 2694 bio->bi_sector = r10_bio->devs[slot].addr
f8c9e74f 2695 + choose_data_offset(r10_bio, rdev);
560f8e55
N
2696 bio->bi_bdev = rdev->bdev;
2697 bio->bi_rw = READ | do_sync;
2698 bio->bi_private = r10_bio;
2699 bio->bi_end_io = raid10_end_read_request;
7399c31b
N
2700 if (max_sectors < r10_bio->sectors) {
2701 /* Drat - have to split this up more */
2702 struct bio *mbio = r10_bio->master_bio;
2703 int sectors_handled =
2704 r10_bio->sector + max_sectors
2705 - mbio->bi_sector;
2706 r10_bio->sectors = max_sectors;
2707 spin_lock_irq(&conf->device_lock);
2708 if (mbio->bi_phys_segments == 0)
2709 mbio->bi_phys_segments = 2;
2710 else
2711 mbio->bi_phys_segments++;
2712 spin_unlock_irq(&conf->device_lock);
2713 generic_make_request(bio);
7399c31b
N
2714
2715 r10_bio = mempool_alloc(conf->r10bio_pool,
2716 GFP_NOIO);
2717 r10_bio->master_bio = mbio;
aa8b57aa 2718 r10_bio->sectors = bio_sectors(mbio) - sectors_handled;
7399c31b
N
2719 r10_bio->state = 0;
2720 set_bit(R10BIO_ReadError,
2721 &r10_bio->state);
2722 r10_bio->mddev = mddev;
2723 r10_bio->sector = mbio->bi_sector
2724 + sectors_handled;
2725
2726 goto read_more;
2727 } else
2728 generic_make_request(bio);
560f8e55
N
2729}
2730
e879a879 2731static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
749c55e9
N
2732{
2733 /* Some sort of write request has finished and it
2734 * succeeded in writing where we thought there was a
2735 * bad block. So forget the bad block.
1a0b7cd8
N
2736 * Or possibly if failed and we need to record
2737 * a bad block.
749c55e9
N
2738 */
2739 int m;
3cb03002 2740 struct md_rdev *rdev;
749c55e9
N
2741
2742 if (test_bit(R10BIO_IsSync, &r10_bio->state) ||
2743 test_bit(R10BIO_IsRecover, &r10_bio->state)) {
1a0b7cd8
N
2744 for (m = 0; m < conf->copies; m++) {
2745 int dev = r10_bio->devs[m].devnum;
2746 rdev = conf->mirrors[dev].rdev;
2747 if (r10_bio->devs[m].bio == NULL)
2748 continue;
2749 if (test_bit(BIO_UPTODATE,
749c55e9 2750 &r10_bio->devs[m].bio->bi_flags)) {
749c55e9
N
2751 rdev_clear_badblocks(
2752 rdev,
2753 r10_bio->devs[m].addr,
c6563a8c 2754 r10_bio->sectors, 0);
1a0b7cd8
N
2755 } else {
2756 if (!rdev_set_badblocks(
2757 rdev,
2758 r10_bio->devs[m].addr,
2759 r10_bio->sectors, 0))
2760 md_error(conf->mddev, rdev);
749c55e9 2761 }
9ad1aefc
N
2762 rdev = conf->mirrors[dev].replacement;
2763 if (r10_bio->devs[m].repl_bio == NULL)
2764 continue;
2765 if (test_bit(BIO_UPTODATE,
2766 &r10_bio->devs[m].repl_bio->bi_flags)) {
2767 rdev_clear_badblocks(
2768 rdev,
2769 r10_bio->devs[m].addr,
c6563a8c 2770 r10_bio->sectors, 0);
9ad1aefc
N
2771 } else {
2772 if (!rdev_set_badblocks(
2773 rdev,
2774 r10_bio->devs[m].addr,
2775 r10_bio->sectors, 0))
2776 md_error(conf->mddev, rdev);
2777 }
1a0b7cd8 2778 }
749c55e9
N
2779 put_buf(r10_bio);
2780 } else {
bd870a16
N
2781 for (m = 0; m < conf->copies; m++) {
2782 int dev = r10_bio->devs[m].devnum;
2783 struct bio *bio = r10_bio->devs[m].bio;
2784 rdev = conf->mirrors[dev].rdev;
2785 if (bio == IO_MADE_GOOD) {
749c55e9
N
2786 rdev_clear_badblocks(
2787 rdev,
2788 r10_bio->devs[m].addr,
c6563a8c 2789 r10_bio->sectors, 0);
749c55e9 2790 rdev_dec_pending(rdev, conf->mddev);
bd870a16
N
2791 } else if (bio != NULL &&
2792 !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2793 if (!narrow_write_error(r10_bio, m)) {
2794 md_error(conf->mddev, rdev);
2795 set_bit(R10BIO_Degraded,
2796 &r10_bio->state);
2797 }
2798 rdev_dec_pending(rdev, conf->mddev);
749c55e9 2799 }
475b0321
N
2800 bio = r10_bio->devs[m].repl_bio;
2801 rdev = conf->mirrors[dev].replacement;
4ca40c2c 2802 if (rdev && bio == IO_MADE_GOOD) {
475b0321
N
2803 rdev_clear_badblocks(
2804 rdev,
2805 r10_bio->devs[m].addr,
c6563a8c 2806 r10_bio->sectors, 0);
475b0321
N
2807 rdev_dec_pending(rdev, conf->mddev);
2808 }
bd870a16
N
2809 }
2810 if (test_bit(R10BIO_WriteError,
2811 &r10_bio->state))
2812 close_write(r10_bio);
749c55e9
N
2813 raid_end_bio_io(r10_bio);
2814 }
2815}
2816
4ed8731d 2817static void raid10d(struct md_thread *thread)
1da177e4 2818{
4ed8731d 2819 struct mddev *mddev = thread->mddev;
9f2c9d12 2820 struct r10bio *r10_bio;
1da177e4 2821 unsigned long flags;
e879a879 2822 struct r10conf *conf = mddev->private;
1da177e4 2823 struct list_head *head = &conf->retry_list;
e1dfa0a2 2824 struct blk_plug plug;
1da177e4
LT
2825
2826 md_check_recovery(mddev);
1da177e4 2827
e1dfa0a2 2828 blk_start_plug(&plug);
1da177e4 2829 for (;;) {
6cce3b23 2830
0021b7bc 2831 flush_pending_writes(conf);
6cce3b23 2832
a35e63ef
N
2833 spin_lock_irqsave(&conf->device_lock, flags);
2834 if (list_empty(head)) {
2835 spin_unlock_irqrestore(&conf->device_lock, flags);
1da177e4 2836 break;
a35e63ef 2837 }
9f2c9d12 2838 r10_bio = list_entry(head->prev, struct r10bio, retry_list);
1da177e4 2839 list_del(head->prev);
4443ae10 2840 conf->nr_queued--;
1da177e4
LT
2841 spin_unlock_irqrestore(&conf->device_lock, flags);
2842
2843 mddev = r10_bio->mddev;
070ec55d 2844 conf = mddev->private;
bd870a16
N
2845 if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
2846 test_bit(R10BIO_WriteError, &r10_bio->state))
749c55e9 2847 handle_write_completed(conf, r10_bio);
3ea7daa5
N
2848 else if (test_bit(R10BIO_IsReshape, &r10_bio->state))
2849 reshape_request_write(mddev, r10_bio);
749c55e9 2850 else if (test_bit(R10BIO_IsSync, &r10_bio->state))
1da177e4 2851 sync_request_write(mddev, r10_bio);
7eaceacc 2852 else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
1da177e4 2853 recovery_request_write(mddev, r10_bio);
856e08e2 2854 else if (test_bit(R10BIO_ReadError, &r10_bio->state))
560f8e55 2855 handle_read_error(mddev, r10_bio);
856e08e2
N
2856 else {
2857 /* just a partial read to be scheduled from a
2858 * separate context
2859 */
2860 int slot = r10_bio->read_slot;
2861 generic_make_request(r10_bio->devs[slot].bio);
2862 }
560f8e55 2863
1d9d5241 2864 cond_resched();
de393cde
N
2865 if (mddev->flags & ~(1<<MD_CHANGE_PENDING))
2866 md_check_recovery(mddev);
1da177e4 2867 }
e1dfa0a2 2868 blk_finish_plug(&plug);
1da177e4
LT
2869}
2870
2871
e879a879 2872static int init_resync(struct r10conf *conf)
1da177e4
LT
2873{
2874 int buffs;
69335ef3 2875 int i;
1da177e4
LT
2876
2877 buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE;
b6385483 2878 BUG_ON(conf->r10buf_pool);
69335ef3 2879 conf->have_replacement = 0;
5cf00fcd 2880 for (i = 0; i < conf->geo.raid_disks; i++)
69335ef3
N
2881 if (conf->mirrors[i].replacement)
2882 conf->have_replacement = 1;
1da177e4
LT
2883 conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf);
2884 if (!conf->r10buf_pool)
2885 return -ENOMEM;
2886 conf->next_resync = 0;
2887 return 0;
2888}
2889
2890/*
2891 * perform a "sync" on one "block"
2892 *
2893 * We need to make sure that no normal I/O request - particularly write
2894 * requests - conflict with active sync requests.
2895 *
2896 * This is achieved by tracking pending requests and a 'barrier' concept
2897 * that can be installed to exclude normal IO requests.
2898 *
2899 * Resync and recovery are handled very differently.
2900 * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery.
2901 *
2902 * For resync, we iterate over virtual addresses, read all copies,
2903 * and update if there are differences. If only one copy is live,
2904 * skip it.
2905 * For recovery, we iterate over physical addresses, read a good
2906 * value for each non-in_sync drive, and over-write.
2907 *
2908 * So, for recovery we may have several outstanding complex requests for a
2909 * given address, one for each out-of-sync device. We model this by allocating
2910 * a number of r10_bio structures, one for each out-of-sync device.
2911 * As we setup these structures, we collect all bio's together into a list
2912 * which we then process collectively to add pages, and then process again
2913 * to pass to generic_make_request.
2914 *
2915 * The r10_bio structures are linked using a borrowed master_bio pointer.
2916 * This link is counted in ->remaining. When the r10_bio that points to NULL
2917 * has its remaining count decremented to 0, the whole complex operation
2918 * is complete.
2919 *
2920 */
2921
fd01b88c 2922static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
ab9d47e9 2923 int *skipped, int go_faster)
1da177e4 2924{
e879a879 2925 struct r10conf *conf = mddev->private;
9f2c9d12 2926 struct r10bio *r10_bio;
1da177e4
LT
2927 struct bio *biolist = NULL, *bio;
2928 sector_t max_sector, nr_sectors;
1da177e4 2929 int i;
6cce3b23 2930 int max_sync;
57dab0bd 2931 sector_t sync_blocks;
1da177e4
LT
2932 sector_t sectors_skipped = 0;
2933 int chunks_skipped = 0;
5cf00fcd 2934 sector_t chunk_mask = conf->geo.chunk_mask;
1da177e4
LT
2935
2936 if (!conf->r10buf_pool)
2937 if (init_resync(conf))
57afd89f 2938 return 0;
1da177e4 2939
7e83ccbe
MW
2940 /*
2941 * Allow skipping a full rebuild for incremental assembly
2942 * of a clean array, like RAID1 does.
2943 */
2944 if (mddev->bitmap == NULL &&
2945 mddev->recovery_cp == MaxSector &&
13765120
N
2946 mddev->reshape_position == MaxSector &&
2947 !test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
7e83ccbe 2948 !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) &&
13765120 2949 !test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
7e83ccbe
MW
2950 conf->fullsync == 0) {
2951 *skipped = 1;
13765120 2952 return mddev->dev_sectors - sector_nr;
7e83ccbe
MW
2953 }
2954
1da177e4 2955 skipped:
58c0fed4 2956 max_sector = mddev->dev_sectors;
3ea7daa5
N
2957 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ||
2958 test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
1da177e4
LT
2959 max_sector = mddev->resync_max_sectors;
2960 if (sector_nr >= max_sector) {
6cce3b23
N
2961 /* If we aborted, we need to abort the
2962 * sync on the 'current' bitmap chucks (there can
2963 * be several when recovering multiple devices).
2964 * as we may have started syncing it but not finished.
2965 * We can find the current address in
2966 * mddev->curr_resync, but for recovery,
2967 * we need to convert that to several
2968 * virtual addresses.
2969 */
3ea7daa5
N
2970 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
2971 end_reshape(conf);
2972 return 0;
2973 }
2974
6cce3b23
N
2975 if (mddev->curr_resync < max_sector) { /* aborted */
2976 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
2977 bitmap_end_sync(mddev->bitmap, mddev->curr_resync,
2978 &sync_blocks, 1);
5cf00fcd 2979 else for (i = 0; i < conf->geo.raid_disks; i++) {
6cce3b23
N
2980 sector_t sect =
2981 raid10_find_virt(conf, mddev->curr_resync, i);
2982 bitmap_end_sync(mddev->bitmap, sect,
2983 &sync_blocks, 1);
2984 }
9ad1aefc
N
2985 } else {
2986 /* completed sync */
2987 if ((!mddev->bitmap || conf->fullsync)
2988 && conf->have_replacement
2989 && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
2990 /* Completed a full sync so the replacements
2991 * are now fully recovered.
2992 */
5cf00fcd 2993 for (i = 0; i < conf->geo.raid_disks; i++)
9ad1aefc
N
2994 if (conf->mirrors[i].replacement)
2995 conf->mirrors[i].replacement
2996 ->recovery_offset
2997 = MaxSector;
2998 }
6cce3b23 2999 conf->fullsync = 0;
9ad1aefc 3000 }
6cce3b23 3001 bitmap_close_sync(mddev->bitmap);
1da177e4 3002 close_sync(conf);
57afd89f 3003 *skipped = 1;
1da177e4
LT
3004 return sectors_skipped;
3005 }
3ea7daa5
N
3006
3007 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3008 return reshape_request(mddev, sector_nr, skipped);
3009
5cf00fcd 3010 if (chunks_skipped >= conf->geo.raid_disks) {
1da177e4
LT
3011 /* if there has been nothing to do on any drive,
3012 * then there is nothing to do at all..
3013 */
57afd89f
N
3014 *skipped = 1;
3015 return (max_sector - sector_nr) + sectors_skipped;
1da177e4
LT
3016 }
3017
c6207277
N
3018 if (max_sector > mddev->resync_max)
3019 max_sector = mddev->resync_max; /* Don't do IO beyond here */
3020
1da177e4
LT
3021 /* make sure whole request will fit in a chunk - if chunks
3022 * are meaningful
3023 */
5cf00fcd
N
3024 if (conf->geo.near_copies < conf->geo.raid_disks &&
3025 max_sector > (sector_nr | chunk_mask))
3026 max_sector = (sector_nr | chunk_mask) + 1;
1da177e4
LT
3027 /*
3028 * If there is non-resync activity waiting for us then
3029 * put in a delay to throttle resync.
3030 */
0a27ec96 3031 if (!go_faster && conf->nr_waiting)
1da177e4 3032 msleep_interruptible(1000);
1da177e4
LT
3033
3034 /* Again, very different code for resync and recovery.
3035 * Both must result in an r10bio with a list of bios that
3036 * have bi_end_io, bi_sector, bi_bdev set,
3037 * and bi_private set to the r10bio.
3038 * For recovery, we may actually create several r10bios
3039 * with 2 bios in each, that correspond to the bios in the main one.
3040 * In this case, the subordinate r10bios link back through a
3041 * borrowed master_bio pointer, and the counter in the master
3042 * includes a ref from each subordinate.
3043 */
3044 /* First, we decide what to do and set ->bi_end_io
3045 * To end_sync_read if we want to read, and
3046 * end_sync_write if we will want to write.
3047 */
3048
6cce3b23 3049 max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
1da177e4
LT
3050 if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3051 /* recovery... the complicated one */
e875ecea 3052 int j;
1da177e4
LT
3053 r10_bio = NULL;
3054
5cf00fcd 3055 for (i = 0 ; i < conf->geo.raid_disks; i++) {
ab9d47e9 3056 int still_degraded;
9f2c9d12 3057 struct r10bio *rb2;
ab9d47e9
N
3058 sector_t sect;
3059 int must_sync;
e875ecea 3060 int any_working;
dc280d98 3061 struct raid10_info *mirror = &conf->mirrors[i];
24afd80d
N
3062
3063 if ((mirror->rdev == NULL ||
3064 test_bit(In_sync, &mirror->rdev->flags))
3065 &&
3066 (mirror->replacement == NULL ||
3067 test_bit(Faulty,
3068 &mirror->replacement->flags)))
ab9d47e9 3069 continue;
1da177e4 3070
ab9d47e9
N
3071 still_degraded = 0;
3072 /* want to reconstruct this device */
3073 rb2 = r10_bio;
3074 sect = raid10_find_virt(conf, sector_nr, i);
fc448a18
N
3075 if (sect >= mddev->resync_max_sectors) {
3076 /* last stripe is not complete - don't
3077 * try to recover this sector.
3078 */
3079 continue;
3080 }
24afd80d
N
3081 /* Unless we are doing a full sync, or a replacement
3082 * we only need to recover the block if it is set in
3083 * the bitmap
ab9d47e9
N
3084 */
3085 must_sync = bitmap_start_sync(mddev->bitmap, sect,
3086 &sync_blocks, 1);
3087 if (sync_blocks < max_sync)
3088 max_sync = sync_blocks;
3089 if (!must_sync &&
24afd80d 3090 mirror->replacement == NULL &&
ab9d47e9
N
3091 !conf->fullsync) {
3092 /* yep, skip the sync_blocks here, but don't assume
3093 * that there will never be anything to do here
3094 */
3095 chunks_skipped = -1;
3096 continue;
3097 }
6cce3b23 3098
ab9d47e9
N
3099 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
3100 raise_barrier(conf, rb2 != NULL);
3101 atomic_set(&r10_bio->remaining, 0);
18055569 3102
ab9d47e9
N
3103 r10_bio->master_bio = (struct bio*)rb2;
3104 if (rb2)
3105 atomic_inc(&rb2->remaining);
3106 r10_bio->mddev = mddev;
3107 set_bit(R10BIO_IsRecover, &r10_bio->state);
3108 r10_bio->sector = sect;
1da177e4 3109
ab9d47e9
N
3110 raid10_find_phys(conf, r10_bio);
3111
3112 /* Need to check if the array will still be
3113 * degraded
3114 */
5cf00fcd 3115 for (j = 0; j < conf->geo.raid_disks; j++)
ab9d47e9
N
3116 if (conf->mirrors[j].rdev == NULL ||
3117 test_bit(Faulty, &conf->mirrors[j].rdev->flags)) {
3118 still_degraded = 1;
87fc767b 3119 break;
1da177e4 3120 }
ab9d47e9
N
3121
3122 must_sync = bitmap_start_sync(mddev->bitmap, sect,
3123 &sync_blocks, still_degraded);
3124
e875ecea 3125 any_working = 0;
ab9d47e9 3126 for (j=0; j<conf->copies;j++) {
e875ecea 3127 int k;
ab9d47e9 3128 int d = r10_bio->devs[j].devnum;
5e570289 3129 sector_t from_addr, to_addr;
3cb03002 3130 struct md_rdev *rdev;
40c356ce
N
3131 sector_t sector, first_bad;
3132 int bad_sectors;
ab9d47e9
N
3133 if (!conf->mirrors[d].rdev ||
3134 !test_bit(In_sync, &conf->mirrors[d].rdev->flags))
3135 continue;
3136 /* This is where we read from */
e875ecea 3137 any_working = 1;
40c356ce
N
3138 rdev = conf->mirrors[d].rdev;
3139 sector = r10_bio->devs[j].addr;
3140
3141 if (is_badblock(rdev, sector, max_sync,
3142 &first_bad, &bad_sectors)) {
3143 if (first_bad > sector)
3144 max_sync = first_bad - sector;
3145 else {
3146 bad_sectors -= (sector
3147 - first_bad);
3148 if (max_sync > bad_sectors)
3149 max_sync = bad_sectors;
3150 continue;
3151 }
3152 }
ab9d47e9 3153 bio = r10_bio->devs[0].bio;
8be185f2 3154 bio_reset(bio);
ab9d47e9
N
3155 bio->bi_next = biolist;
3156 biolist = bio;
3157 bio->bi_private = r10_bio;
3158 bio->bi_end_io = end_sync_read;
3159 bio->bi_rw = READ;
5e570289 3160 from_addr = r10_bio->devs[j].addr;
24afd80d
N
3161 bio->bi_sector = from_addr + rdev->data_offset;
3162 bio->bi_bdev = rdev->bdev;
3163 atomic_inc(&rdev->nr_pending);
3164 /* and we write to 'i' (if not in_sync) */
ab9d47e9
N
3165
3166 for (k=0; k<conf->copies; k++)
3167 if (r10_bio->devs[k].devnum == i)
3168 break;
3169 BUG_ON(k == conf->copies);
5e570289 3170 to_addr = r10_bio->devs[k].addr;
ab9d47e9 3171 r10_bio->devs[0].devnum = d;
5e570289 3172 r10_bio->devs[0].addr = from_addr;
ab9d47e9 3173 r10_bio->devs[1].devnum = i;
5e570289 3174 r10_bio->devs[1].addr = to_addr;
ab9d47e9 3175
24afd80d
N
3176 rdev = mirror->rdev;
3177 if (!test_bit(In_sync, &rdev->flags)) {
3178 bio = r10_bio->devs[1].bio;
8be185f2 3179 bio_reset(bio);
24afd80d
N
3180 bio->bi_next = biolist;
3181 biolist = bio;
3182 bio->bi_private = r10_bio;
3183 bio->bi_end_io = end_sync_write;
3184 bio->bi_rw = WRITE;
3185 bio->bi_sector = to_addr
3186 + rdev->data_offset;
3187 bio->bi_bdev = rdev->bdev;
3188 atomic_inc(&r10_bio->remaining);
3189 } else
3190 r10_bio->devs[1].bio->bi_end_io = NULL;
3191
3192 /* and maybe write to replacement */
3193 bio = r10_bio->devs[1].repl_bio;
3194 if (bio)
3195 bio->bi_end_io = NULL;
3196 rdev = mirror->replacement;
3197 /* Note: if rdev != NULL, then bio
3198 * cannot be NULL as r10buf_pool_alloc will
3199 * have allocated it.
3200 * So the second test here is pointless.
3201 * But it keeps semantic-checkers happy, and
3202 * this comment keeps human reviewers
3203 * happy.
3204 */
3205 if (rdev == NULL || bio == NULL ||
3206 test_bit(Faulty, &rdev->flags))
3207 break;
8be185f2 3208 bio_reset(bio);
24afd80d
N
3209 bio->bi_next = biolist;
3210 biolist = bio;
3211 bio->bi_private = r10_bio;
3212 bio->bi_end_io = end_sync_write;
3213 bio->bi_rw = WRITE;
3214 bio->bi_sector = to_addr + rdev->data_offset;
3215 bio->bi_bdev = rdev->bdev;
3216 atomic_inc(&r10_bio->remaining);
ab9d47e9
N
3217 break;
3218 }
3219 if (j == conf->copies) {
e875ecea
N
3220 /* Cannot recover, so abort the recovery or
3221 * record a bad block */
ab9d47e9
N
3222 put_buf(r10_bio);
3223 if (rb2)
3224 atomic_dec(&rb2->remaining);
3225 r10_bio = rb2;
e875ecea
N
3226 if (any_working) {
3227 /* problem is that there are bad blocks
3228 * on other device(s)
3229 */
3230 int k;
3231 for (k = 0; k < conf->copies; k++)
3232 if (r10_bio->devs[k].devnum == i)
3233 break;
24afd80d
N
3234 if (!test_bit(In_sync,
3235 &mirror->rdev->flags)
3236 && !rdev_set_badblocks(
3237 mirror->rdev,
3238 r10_bio->devs[k].addr,
3239 max_sync, 0))
3240 any_working = 0;
3241 if (mirror->replacement &&
3242 !rdev_set_badblocks(
3243 mirror->replacement,
e875ecea
N
3244 r10_bio->devs[k].addr,
3245 max_sync, 0))
3246 any_working = 0;
3247 }
3248 if (!any_working) {
3249 if (!test_and_set_bit(MD_RECOVERY_INTR,
3250 &mddev->recovery))
3251 printk(KERN_INFO "md/raid10:%s: insufficient "
3252 "working devices for recovery.\n",
3253 mdname(mddev));
24afd80d 3254 mirror->recovery_disabled
e875ecea
N
3255 = mddev->recovery_disabled;
3256 }
ab9d47e9 3257 break;
1da177e4 3258 }
ab9d47e9 3259 }
1da177e4
LT
3260 if (biolist == NULL) {
3261 while (r10_bio) {
9f2c9d12
N
3262 struct r10bio *rb2 = r10_bio;
3263 r10_bio = (struct r10bio*) rb2->master_bio;
1da177e4
LT
3264 rb2->master_bio = NULL;
3265 put_buf(rb2);
3266 }
3267 goto giveup;
3268 }
3269 } else {
3270 /* resync. Schedule a read for every block at this virt offset */
3271 int count = 0;
6cce3b23 3272
78200d45
N
3273 bitmap_cond_end_sync(mddev->bitmap, sector_nr);
3274
6cce3b23
N
3275 if (!bitmap_start_sync(mddev->bitmap, sector_nr,
3276 &sync_blocks, mddev->degraded) &&
ab9d47e9
N
3277 !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED,
3278 &mddev->recovery)) {
6cce3b23
N
3279 /* We can skip this block */
3280 *skipped = 1;
3281 return sync_blocks + sectors_skipped;
3282 }
3283 if (sync_blocks < max_sync)
3284 max_sync = sync_blocks;
1da177e4
LT
3285 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
3286
1da177e4
LT
3287 r10_bio->mddev = mddev;
3288 atomic_set(&r10_bio->remaining, 0);
6cce3b23
N
3289 raise_barrier(conf, 0);
3290 conf->next_resync = sector_nr;
1da177e4
LT
3291
3292 r10_bio->master_bio = NULL;
3293 r10_bio->sector = sector_nr;
3294 set_bit(R10BIO_IsSync, &r10_bio->state);
3295 raid10_find_phys(conf, r10_bio);
5cf00fcd 3296 r10_bio->sectors = (sector_nr | chunk_mask) - sector_nr + 1;
1da177e4 3297
5cf00fcd 3298 for (i = 0; i < conf->copies; i++) {
1da177e4 3299 int d = r10_bio->devs[i].devnum;
40c356ce
N
3300 sector_t first_bad, sector;
3301 int bad_sectors;
3302
9ad1aefc
N
3303 if (r10_bio->devs[i].repl_bio)
3304 r10_bio->devs[i].repl_bio->bi_end_io = NULL;
3305
1da177e4 3306 bio = r10_bio->devs[i].bio;
8be185f2 3307 bio_reset(bio);
af03b8e4 3308 clear_bit(BIO_UPTODATE, &bio->bi_flags);
1da177e4 3309 if (conf->mirrors[d].rdev == NULL ||
b2d444d7 3310 test_bit(Faulty, &conf->mirrors[d].rdev->flags))
1da177e4 3311 continue;
40c356ce
N
3312 sector = r10_bio->devs[i].addr;
3313 if (is_badblock(conf->mirrors[d].rdev,
3314 sector, max_sync,
3315 &first_bad, &bad_sectors)) {
3316 if (first_bad > sector)
3317 max_sync = first_bad - sector;
3318 else {
3319 bad_sectors -= (sector - first_bad);
3320 if (max_sync > bad_sectors)
91502f09 3321 max_sync = bad_sectors;
40c356ce
N
3322 continue;
3323 }
3324 }
1da177e4
LT
3325 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
3326 atomic_inc(&r10_bio->remaining);
3327 bio->bi_next = biolist;
3328 biolist = bio;
3329 bio->bi_private = r10_bio;
3330 bio->bi_end_io = end_sync_read;
802ba064 3331 bio->bi_rw = READ;
40c356ce 3332 bio->bi_sector = sector +
1da177e4
LT
3333 conf->mirrors[d].rdev->data_offset;
3334 bio->bi_bdev = conf->mirrors[d].rdev->bdev;
3335 count++;
9ad1aefc
N
3336
3337 if (conf->mirrors[d].replacement == NULL ||
3338 test_bit(Faulty,
3339 &conf->mirrors[d].replacement->flags))
3340 continue;
3341
3342 /* Need to set up for writing to the replacement */
3343 bio = r10_bio->devs[i].repl_bio;
8be185f2 3344 bio_reset(bio);
9ad1aefc
N
3345 clear_bit(BIO_UPTODATE, &bio->bi_flags);
3346
3347 sector = r10_bio->devs[i].addr;
3348 atomic_inc(&conf->mirrors[d].rdev->nr_pending);
3349 bio->bi_next = biolist;
3350 biolist = bio;
3351 bio->bi_private = r10_bio;
3352 bio->bi_end_io = end_sync_write;
3353 bio->bi_rw = WRITE;
3354 bio->bi_sector = sector +
3355 conf->mirrors[d].replacement->data_offset;
3356 bio->bi_bdev = conf->mirrors[d].replacement->bdev;
3357 count++;
1da177e4
LT
3358 }
3359
3360 if (count < 2) {
3361 for (i=0; i<conf->copies; i++) {
3362 int d = r10_bio->devs[i].devnum;
3363 if (r10_bio->devs[i].bio->bi_end_io)
ab9d47e9
N
3364 rdev_dec_pending(conf->mirrors[d].rdev,
3365 mddev);
9ad1aefc
N
3366 if (r10_bio->devs[i].repl_bio &&
3367 r10_bio->devs[i].repl_bio->bi_end_io)
3368 rdev_dec_pending(
3369 conf->mirrors[d].replacement,
3370 mddev);
1da177e4
LT
3371 }
3372 put_buf(r10_bio);
3373 biolist = NULL;
3374 goto giveup;
3375 }
3376 }
3377
1da177e4 3378 nr_sectors = 0;
6cce3b23
N
3379 if (sector_nr + max_sync < max_sector)
3380 max_sector = sector_nr + max_sync;
1da177e4
LT
3381 do {
3382 struct page *page;
3383 int len = PAGE_SIZE;
1da177e4
LT
3384 if (sector_nr + (len>>9) > max_sector)
3385 len = (max_sector - sector_nr) << 9;
3386 if (len == 0)
3387 break;
3388 for (bio= biolist ; bio ; bio=bio->bi_next) {
ab9d47e9 3389 struct bio *bio2;
1da177e4 3390 page = bio->bi_io_vec[bio->bi_vcnt].bv_page;
ab9d47e9
N
3391 if (bio_add_page(bio, page, len, 0))
3392 continue;
3393
3394 /* stop here */
3395 bio->bi_io_vec[bio->bi_vcnt].bv_page = page;
3396 for (bio2 = biolist;
3397 bio2 && bio2 != bio;
3398 bio2 = bio2->bi_next) {
3399 /* remove last page from this bio */
3400 bio2->bi_vcnt--;
3401 bio2->bi_size -= len;
3402 bio2->bi_flags &= ~(1<< BIO_SEG_VALID);
1da177e4 3403 }
ab9d47e9 3404 goto bio_full;
1da177e4
LT
3405 }
3406 nr_sectors += len>>9;
3407 sector_nr += len>>9;
3408 } while (biolist->bi_vcnt < RESYNC_PAGES);
3409 bio_full:
3410 r10_bio->sectors = nr_sectors;
3411
3412 while (biolist) {
3413 bio = biolist;
3414 biolist = biolist->bi_next;
3415
3416 bio->bi_next = NULL;
3417 r10_bio = bio->bi_private;
3418 r10_bio->sectors = nr_sectors;
3419
3420 if (bio->bi_end_io == end_sync_read) {
3421 md_sync_acct(bio->bi_bdev, nr_sectors);
7bb23c49 3422 set_bit(BIO_UPTODATE, &bio->bi_flags);
1da177e4
LT
3423 generic_make_request(bio);
3424 }
3425 }
3426
57afd89f
N
3427 if (sectors_skipped)
3428 /* pretend they weren't skipped, it makes
3429 * no important difference in this case
3430 */
3431 md_done_sync(mddev, sectors_skipped, 1);
3432
1da177e4
LT
3433 return sectors_skipped + nr_sectors;
3434 giveup:
3435 /* There is nowhere to write, so all non-sync
e875ecea
N
3436 * drives must be failed or in resync, all drives
3437 * have a bad block, so try the next chunk...
1da177e4 3438 */
09b4068a
N
3439 if (sector_nr + max_sync < max_sector)
3440 max_sector = sector_nr + max_sync;
3441
3442 sectors_skipped += (max_sector - sector_nr);
1da177e4
LT
3443 chunks_skipped ++;
3444 sector_nr = max_sector;
1da177e4 3445 goto skipped;
1da177e4
LT
3446}
3447
80c3a6ce 3448static sector_t
fd01b88c 3449raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks)
80c3a6ce
DW
3450{
3451 sector_t size;
e879a879 3452 struct r10conf *conf = mddev->private;
80c3a6ce
DW
3453
3454 if (!raid_disks)
3ea7daa5
N
3455 raid_disks = min(conf->geo.raid_disks,
3456 conf->prev.raid_disks);
80c3a6ce 3457 if (!sectors)
dab8b292 3458 sectors = conf->dev_sectors;
80c3a6ce 3459
5cf00fcd
N
3460 size = sectors >> conf->geo.chunk_shift;
3461 sector_div(size, conf->geo.far_copies);
80c3a6ce 3462 size = size * raid_disks;
5cf00fcd 3463 sector_div(size, conf->geo.near_copies);
80c3a6ce 3464
5cf00fcd 3465 return size << conf->geo.chunk_shift;
80c3a6ce
DW
3466}
3467
6508fdbf
N
3468static void calc_sectors(struct r10conf *conf, sector_t size)
3469{
3470 /* Calculate the number of sectors-per-device that will
3471 * actually be used, and set conf->dev_sectors and
3472 * conf->stride
3473 */
3474
5cf00fcd
N
3475 size = size >> conf->geo.chunk_shift;
3476 sector_div(size, conf->geo.far_copies);
3477 size = size * conf->geo.raid_disks;
3478 sector_div(size, conf->geo.near_copies);
6508fdbf
N
3479 /* 'size' is now the number of chunks in the array */
3480 /* calculate "used chunks per device" */
3481 size = size * conf->copies;
3482
3483 /* We need to round up when dividing by raid_disks to
3484 * get the stride size.
3485 */
5cf00fcd 3486 size = DIV_ROUND_UP_SECTOR_T(size, conf->geo.raid_disks);
6508fdbf 3487
5cf00fcd 3488 conf->dev_sectors = size << conf->geo.chunk_shift;
6508fdbf 3489
5cf00fcd
N
3490 if (conf->geo.far_offset)
3491 conf->geo.stride = 1 << conf->geo.chunk_shift;
6508fdbf 3492 else {
5cf00fcd
N
3493 sector_div(size, conf->geo.far_copies);
3494 conf->geo.stride = size << conf->geo.chunk_shift;
6508fdbf
N
3495 }
3496}
dab8b292 3497
deb200d0
N
3498enum geo_type {geo_new, geo_old, geo_start};
3499static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new)
3500{
3501 int nc, fc, fo;
3502 int layout, chunk, disks;
3503 switch (new) {
3504 case geo_old:
3505 layout = mddev->layout;
3506 chunk = mddev->chunk_sectors;
3507 disks = mddev->raid_disks - mddev->delta_disks;
3508 break;
3509 case geo_new:
3510 layout = mddev->new_layout;
3511 chunk = mddev->new_chunk_sectors;
3512 disks = mddev->raid_disks;
3513 break;
3514 default: /* avoid 'may be unused' warnings */
3515 case geo_start: /* new when starting reshape - raid_disks not
3516 * updated yet. */
3517 layout = mddev->new_layout;
3518 chunk = mddev->new_chunk_sectors;
3519 disks = mddev->raid_disks + mddev->delta_disks;
3520 break;
3521 }
475901af 3522 if (layout >> 18)
deb200d0
N
3523 return -1;
3524 if (chunk < (PAGE_SIZE >> 9) ||
3525 !is_power_of_2(chunk))
3526 return -2;
3527 nc = layout & 255;
3528 fc = (layout >> 8) & 255;
3529 fo = layout & (1<<16);
3530 geo->raid_disks = disks;
3531 geo->near_copies = nc;
3532 geo->far_copies = fc;
3533 geo->far_offset = fo;
475901af 3534 geo->far_set_size = (layout & (1<<17)) ? disks / fc : disks;
deb200d0
N
3535 geo->chunk_mask = chunk - 1;
3536 geo->chunk_shift = ffz(~chunk);
3537 return nc*fc;
3538}
3539
e879a879 3540static struct r10conf *setup_conf(struct mddev *mddev)
1da177e4 3541{
e879a879 3542 struct r10conf *conf = NULL;
dab8b292 3543 int err = -EINVAL;
deb200d0
N
3544 struct geom geo;
3545 int copies;
3546
3547 copies = setup_geo(&geo, mddev, geo_new);
1da177e4 3548
deb200d0 3549 if (copies == -2) {
128595ed
N
3550 printk(KERN_ERR "md/raid10:%s: chunk size must be "
3551 "at least PAGE_SIZE(%ld) and be a power of 2.\n",
3552 mdname(mddev), PAGE_SIZE);
dab8b292 3553 goto out;
1da177e4 3554 }
2604b703 3555
deb200d0 3556 if (copies < 2 || copies > mddev->raid_disks) {
128595ed 3557 printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n",
f73ea873 3558 mdname(mddev), mddev->new_layout);
1da177e4
LT
3559 goto out;
3560 }
dab8b292
TM
3561
3562 err = -ENOMEM;
e879a879 3563 conf = kzalloc(sizeof(struct r10conf), GFP_KERNEL);
dab8b292 3564 if (!conf)
1da177e4 3565 goto out;
dab8b292 3566
3ea7daa5 3567 /* FIXME calc properly */
dc280d98 3568 conf->mirrors = kzalloc(sizeof(struct raid10_info)*(mddev->raid_disks +
78eaa0d4 3569 max(0,-mddev->delta_disks)),
dab8b292
TM
3570 GFP_KERNEL);
3571 if (!conf->mirrors)
3572 goto out;
4443ae10
N
3573
3574 conf->tmppage = alloc_page(GFP_KERNEL);
3575 if (!conf->tmppage)
dab8b292
TM
3576 goto out;
3577
deb200d0
N
3578 conf->geo = geo;
3579 conf->copies = copies;
dab8b292
TM
3580 conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc,
3581 r10bio_pool_free, conf);
3582 if (!conf->r10bio_pool)
3583 goto out;
3584
6508fdbf 3585 calc_sectors(conf, mddev->dev_sectors);
3ea7daa5
N
3586 if (mddev->reshape_position == MaxSector) {
3587 conf->prev = conf->geo;
3588 conf->reshape_progress = MaxSector;
3589 } else {
3590 if (setup_geo(&conf->prev, mddev, geo_old) != conf->copies) {
3591 err = -EINVAL;
3592 goto out;
3593 }
3594 conf->reshape_progress = mddev->reshape_position;
3595 if (conf->prev.far_offset)
3596 conf->prev.stride = 1 << conf->prev.chunk_shift;
3597 else
3598 /* far_copies must be 1 */
3599 conf->prev.stride = conf->dev_sectors;
3600 }
e7e72bf6 3601 spin_lock_init(&conf->device_lock);
dab8b292
TM
3602 INIT_LIST_HEAD(&conf->retry_list);
3603
3604 spin_lock_init(&conf->resync_lock);
3605 init_waitqueue_head(&conf->wait_barrier);
3606
0232605d 3607 conf->thread = md_register_thread(raid10d, mddev, "raid10");
dab8b292
TM
3608 if (!conf->thread)
3609 goto out;
3610
dab8b292
TM
3611 conf->mddev = mddev;
3612 return conf;
3613
3614 out:
3ea7daa5
N
3615 if (err == -ENOMEM)
3616 printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n",
3617 mdname(mddev));
dab8b292
TM
3618 if (conf) {
3619 if (conf->r10bio_pool)
3620 mempool_destroy(conf->r10bio_pool);
3621 kfree(conf->mirrors);
3622 safe_put_page(conf->tmppage);
3623 kfree(conf);
3624 }
3625 return ERR_PTR(err);
3626}
3627
fd01b88c 3628static int run(struct mddev *mddev)
dab8b292 3629{
e879a879 3630 struct r10conf *conf;
dab8b292 3631 int i, disk_idx, chunk_size;
dc280d98 3632 struct raid10_info *disk;
3cb03002 3633 struct md_rdev *rdev;
dab8b292 3634 sector_t size;
3ea7daa5
N
3635 sector_t min_offset_diff = 0;
3636 int first = 1;
532a2a3f 3637 bool discard_supported = false;
dab8b292
TM
3638
3639 if (mddev->private == NULL) {
3640 conf = setup_conf(mddev);
3641 if (IS_ERR(conf))
3642 return PTR_ERR(conf);
3643 mddev->private = conf;
3644 }
3645 conf = mddev->private;
3646 if (!conf)
3647 goto out;
3648
dab8b292
TM
3649 mddev->thread = conf->thread;
3650 conf->thread = NULL;
3651
8f6c2e4b 3652 chunk_size = mddev->chunk_sectors << 9;
cc4d1efd 3653 if (mddev->queue) {
532a2a3f
SL
3654 blk_queue_max_discard_sectors(mddev->queue,
3655 mddev->chunk_sectors);
5026d7a9 3656 blk_queue_max_write_same_sectors(mddev->queue, 0);
cc4d1efd
JB
3657 blk_queue_io_min(mddev->queue, chunk_size);
3658 if (conf->geo.raid_disks % conf->geo.near_copies)
3659 blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);
3660 else
3661 blk_queue_io_opt(mddev->queue, chunk_size *
3662 (conf->geo.raid_disks / conf->geo.near_copies));
3663 }
8f6c2e4b 3664
dafb20fa 3665 rdev_for_each(rdev, mddev) {
3ea7daa5 3666 long long diff;
aba336bd 3667 struct request_queue *q;
34b343cf 3668
1da177e4 3669 disk_idx = rdev->raid_disk;
f8c9e74f
N
3670 if (disk_idx < 0)
3671 continue;
3672 if (disk_idx >= conf->geo.raid_disks &&
3673 disk_idx >= conf->prev.raid_disks)
1da177e4
LT
3674 continue;
3675 disk = conf->mirrors + disk_idx;
3676
56a2559b
N
3677 if (test_bit(Replacement, &rdev->flags)) {
3678 if (disk->replacement)
3679 goto out_free_conf;
3680 disk->replacement = rdev;
3681 } else {
3682 if (disk->rdev)
3683 goto out_free_conf;
3684 disk->rdev = rdev;
3685 }
aba336bd
N
3686 q = bdev_get_queue(rdev->bdev);
3687 if (q->merge_bvec_fn)
3688 mddev->merge_check_needed = 1;
3ea7daa5
N
3689 diff = (rdev->new_data_offset - rdev->data_offset);
3690 if (!mddev->reshape_backwards)
3691 diff = -diff;
3692 if (diff < 0)
3693 diff = 0;
3694 if (first || diff < min_offset_diff)
3695 min_offset_diff = diff;
56a2559b 3696
cc4d1efd
JB
3697 if (mddev->gendisk)
3698 disk_stack_limits(mddev->gendisk, rdev->bdev,
3699 rdev->data_offset << 9);
1da177e4
LT
3700
3701 disk->head_position = 0;
532a2a3f
SL
3702
3703 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
3704 discard_supported = true;
1da177e4 3705 }
3ea7daa5 3706
ed30be07
JB
3707 if (mddev->queue) {
3708 if (discard_supported)
3709 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
3710 mddev->queue);
3711 else
3712 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
3713 mddev->queue);
3714 }
6d508242 3715 /* need to check that every block has at least one working mirror */
700c7213 3716 if (!enough(conf, -1)) {
128595ed 3717 printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",
6d508242 3718 mdname(mddev));
1da177e4
LT
3719 goto out_free_conf;
3720 }
3721
3ea7daa5
N
3722 if (conf->reshape_progress != MaxSector) {
3723 /* must ensure that shape change is supported */
3724 if (conf->geo.far_copies != 1 &&
3725 conf->geo.far_offset == 0)
3726 goto out_free_conf;
3727 if (conf->prev.far_copies != 1 &&
78eaa0d4 3728 conf->prev.far_offset == 0)
3ea7daa5
N
3729 goto out_free_conf;
3730 }
3731
1da177e4 3732 mddev->degraded = 0;
f8c9e74f
N
3733 for (i = 0;
3734 i < conf->geo.raid_disks
3735 || i < conf->prev.raid_disks;
3736 i++) {
1da177e4
LT
3737
3738 disk = conf->mirrors + i;
3739
56a2559b
N
3740 if (!disk->rdev && disk->replacement) {
3741 /* The replacement is all we have - use it */
3742 disk->rdev = disk->replacement;
3743 disk->replacement = NULL;
3744 clear_bit(Replacement, &disk->rdev->flags);
3745 }
3746
5fd6c1dc 3747 if (!disk->rdev ||
2e333e89 3748 !test_bit(In_sync, &disk->rdev->flags)) {
1da177e4
LT
3749 disk->head_position = 0;
3750 mddev->degraded++;
8c2e870a
NB
3751 if (disk->rdev)
3752 conf->fullsync = 1;
1da177e4 3753 }
d890fa2b 3754 disk->recovery_disabled = mddev->recovery_disabled - 1;
1da177e4
LT
3755 }
3756
8c6ac868 3757 if (mddev->recovery_cp != MaxSector)
128595ed 3758 printk(KERN_NOTICE "md/raid10:%s: not clean"
8c6ac868
AN
3759 " -- starting background reconstruction\n",
3760 mdname(mddev));
1da177e4 3761 printk(KERN_INFO
128595ed 3762 "md/raid10:%s: active with %d out of %d devices\n",
5cf00fcd
N
3763 mdname(mddev), conf->geo.raid_disks - mddev->degraded,
3764 conf->geo.raid_disks);
1da177e4
LT
3765 /*
3766 * Ok, everything is just fine now
3767 */
dab8b292
TM
3768 mddev->dev_sectors = conf->dev_sectors;
3769 size = raid10_size(mddev, 0, 0);
3770 md_set_array_sectors(mddev, size);
3771 mddev->resync_max_sectors = size;
1da177e4 3772
cc4d1efd 3773 if (mddev->queue) {
5cf00fcd 3774 int stripe = conf->geo.raid_disks *
9d8f0363 3775 ((mddev->chunk_sectors << 9) / PAGE_SIZE);
cc4d1efd
JB
3776 mddev->queue->backing_dev_info.congested_fn = raid10_congested;
3777 mddev->queue->backing_dev_info.congested_data = mddev;
3778
3779 /* Calculate max read-ahead size.
3780 * We need to readahead at least twice a whole stripe....
3781 * maybe...
3782 */
5cf00fcd 3783 stripe /= conf->geo.near_copies;
3ea7daa5
N
3784 if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
3785 mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
cc4d1efd 3786 blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec);
1da177e4
LT
3787 }
3788
a91a2785
MP
3789
3790 if (md_integrity_register(mddev))
3791 goto out_free_conf;
3792
3ea7daa5
N
3793 if (conf->reshape_progress != MaxSector) {
3794 unsigned long before_length, after_length;
3795
3796 before_length = ((1 << conf->prev.chunk_shift) *
3797 conf->prev.far_copies);
3798 after_length = ((1 << conf->geo.chunk_shift) *
3799 conf->geo.far_copies);
3800
3801 if (max(before_length, after_length) > min_offset_diff) {
3802 /* This cannot work */
3803 printk("md/raid10: offset difference not enough to continue reshape\n");
3804 goto out_free_conf;
3805 }
3806 conf->offset_diff = min_offset_diff;
3807
3808 conf->reshape_safe = conf->reshape_progress;
3809 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3810 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3811 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
3812 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
3813 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
3814 "reshape");
3815 }
3816
1da177e4
LT
3817 return 0;
3818
3819out_free_conf:
01f96c0a 3820 md_unregister_thread(&mddev->thread);
1da177e4
LT
3821 if (conf->r10bio_pool)
3822 mempool_destroy(conf->r10bio_pool);
1345b1d8 3823 safe_put_page(conf->tmppage);
990a8baf 3824 kfree(conf->mirrors);
1da177e4
LT
3825 kfree(conf);
3826 mddev->private = NULL;
3827out:
3828 return -EIO;
3829}
3830
fd01b88c 3831static int stop(struct mddev *mddev)
1da177e4 3832{
e879a879 3833 struct r10conf *conf = mddev->private;
1da177e4 3834
409c57f3
N
3835 raise_barrier(conf, 0);
3836 lower_barrier(conf);
3837
01f96c0a 3838 md_unregister_thread(&mddev->thread);
cc4d1efd
JB
3839 if (mddev->queue)
3840 /* the unplug fn references 'conf'*/
3841 blk_sync_queue(mddev->queue);
3842
1da177e4
LT
3843 if (conf->r10bio_pool)
3844 mempool_destroy(conf->r10bio_pool);
0fea7ed8 3845 safe_put_page(conf->tmppage);
990a8baf 3846 kfree(conf->mirrors);
1da177e4
LT
3847 kfree(conf);
3848 mddev->private = NULL;
3849 return 0;
3850}
3851
fd01b88c 3852static void raid10_quiesce(struct mddev *mddev, int state)
6cce3b23 3853{
e879a879 3854 struct r10conf *conf = mddev->private;
6cce3b23
N
3855
3856 switch(state) {
3857 case 1:
3858 raise_barrier(conf, 0);
3859 break;
3860 case 0:
3861 lower_barrier(conf);
3862 break;
3863 }
6cce3b23 3864}
1da177e4 3865
006a09a0
N
3866static int raid10_resize(struct mddev *mddev, sector_t sectors)
3867{
3868 /* Resize of 'far' arrays is not supported.
3869 * For 'near' and 'offset' arrays we can set the
3870 * number of sectors used to be an appropriate multiple
3871 * of the chunk size.
3872 * For 'offset', this is far_copies*chunksize.
3873 * For 'near' the multiplier is the LCM of
3874 * near_copies and raid_disks.
3875 * So if far_copies > 1 && !far_offset, fail.
3876 * Else find LCM(raid_disks, near_copy)*far_copies and
3877 * multiply by chunk_size. Then round to this number.
3878 * This is mostly done by raid10_size()
3879 */
3880 struct r10conf *conf = mddev->private;
3881 sector_t oldsize, size;
3882
f8c9e74f
N
3883 if (mddev->reshape_position != MaxSector)
3884 return -EBUSY;
3885
5cf00fcd 3886 if (conf->geo.far_copies > 1 && !conf->geo.far_offset)
006a09a0
N
3887 return -EINVAL;
3888
3889 oldsize = raid10_size(mddev, 0, 0);
3890 size = raid10_size(mddev, sectors, 0);
a4a6125a
N
3891 if (mddev->external_size &&
3892 mddev->array_sectors > size)
006a09a0 3893 return -EINVAL;
a4a6125a
N
3894 if (mddev->bitmap) {
3895 int ret = bitmap_resize(mddev->bitmap, size, 0, 0);
3896 if (ret)
3897 return ret;
3898 }
3899 md_set_array_sectors(mddev, size);
006a09a0
N
3900 set_capacity(mddev->gendisk, mddev->array_sectors);
3901 revalidate_disk(mddev->gendisk);
3902 if (sectors > mddev->dev_sectors &&
3903 mddev->recovery_cp > oldsize) {
3904 mddev->recovery_cp = oldsize;
3905 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3906 }
6508fdbf
N
3907 calc_sectors(conf, sectors);
3908 mddev->dev_sectors = conf->dev_sectors;
006a09a0
N
3909 mddev->resync_max_sectors = size;
3910 return 0;
3911}
3912
fd01b88c 3913static void *raid10_takeover_raid0(struct mddev *mddev)
dab8b292 3914{
3cb03002 3915 struct md_rdev *rdev;
e879a879 3916 struct r10conf *conf;
dab8b292
TM
3917
3918 if (mddev->degraded > 0) {
128595ed
N
3919 printk(KERN_ERR "md/raid10:%s: Error: degraded raid0!\n",
3920 mdname(mddev));
dab8b292
TM
3921 return ERR_PTR(-EINVAL);
3922 }
3923
dab8b292
TM
3924 /* Set new parameters */
3925 mddev->new_level = 10;
3926 /* new layout: far_copies = 1, near_copies = 2 */
3927 mddev->new_layout = (1<<8) + 2;
3928 mddev->new_chunk_sectors = mddev->chunk_sectors;
3929 mddev->delta_disks = mddev->raid_disks;
dab8b292
TM
3930 mddev->raid_disks *= 2;
3931 /* make sure it will be not marked as dirty */
3932 mddev->recovery_cp = MaxSector;
3933
3934 conf = setup_conf(mddev);
02214dc5 3935 if (!IS_ERR(conf)) {
dafb20fa 3936 rdev_for_each(rdev, mddev)
e93f68a1
N
3937 if (rdev->raid_disk >= 0)
3938 rdev->new_raid_disk = rdev->raid_disk * 2;
02214dc5
KW
3939 conf->barrier = 1;
3940 }
3941
dab8b292
TM
3942 return conf;
3943}
3944
fd01b88c 3945static void *raid10_takeover(struct mddev *mddev)
dab8b292 3946{
e373ab10 3947 struct r0conf *raid0_conf;
dab8b292
TM
3948
3949 /* raid10 can take over:
3950 * raid0 - providing it has only two drives
3951 */
3952 if (mddev->level == 0) {
3953 /* for raid0 takeover only one zone is supported */
e373ab10
N
3954 raid0_conf = mddev->private;
3955 if (raid0_conf->nr_strip_zones > 1) {
128595ed
N
3956 printk(KERN_ERR "md/raid10:%s: cannot takeover raid 0"
3957 " with more than one zone.\n",
3958 mdname(mddev));
dab8b292
TM
3959 return ERR_PTR(-EINVAL);
3960 }
3961 return raid10_takeover_raid0(mddev);
3962 }
3963 return ERR_PTR(-EINVAL);
3964}
3965
3ea7daa5
N
3966static int raid10_check_reshape(struct mddev *mddev)
3967{
3968 /* Called when there is a request to change
3969 * - layout (to ->new_layout)
3970 * - chunk size (to ->new_chunk_sectors)
3971 * - raid_disks (by delta_disks)
3972 * or when trying to restart a reshape that was ongoing.
3973 *
3974 * We need to validate the request and possibly allocate
3975 * space if that might be an issue later.
3976 *
3977 * Currently we reject any reshape of a 'far' mode array,
3978 * allow chunk size to change if new is generally acceptable,
3979 * allow raid_disks to increase, and allow
3980 * a switch between 'near' mode and 'offset' mode.
3981 */
3982 struct r10conf *conf = mddev->private;
3983 struct geom geo;
3984
3985 if (conf->geo.far_copies != 1 && !conf->geo.far_offset)
3986 return -EINVAL;
3987
3988 if (setup_geo(&geo, mddev, geo_start) != conf->copies)
3989 /* mustn't change number of copies */
3990 return -EINVAL;
3991 if (geo.far_copies > 1 && !geo.far_offset)
3992 /* Cannot switch to 'far' mode */
3993 return -EINVAL;
3994
3995 if (mddev->array_sectors & geo.chunk_mask)
3996 /* not factor of array size */
3997 return -EINVAL;
3998
3ea7daa5
N
3999 if (!enough(conf, -1))
4000 return -EINVAL;
4001
4002 kfree(conf->mirrors_new);
4003 conf->mirrors_new = NULL;
4004 if (mddev->delta_disks > 0) {
4005 /* allocate new 'mirrors' list */
4006 conf->mirrors_new = kzalloc(
dc280d98 4007 sizeof(struct raid10_info)
3ea7daa5
N
4008 *(mddev->raid_disks +
4009 mddev->delta_disks),
4010 GFP_KERNEL);
4011 if (!conf->mirrors_new)
4012 return -ENOMEM;
4013 }
4014 return 0;
4015}
4016
4017/*
4018 * Need to check if array has failed when deciding whether to:
4019 * - start an array
4020 * - remove non-faulty devices
4021 * - add a spare
4022 * - allow a reshape
4023 * This determination is simple when no reshape is happening.
4024 * However if there is a reshape, we need to carefully check
4025 * both the before and after sections.
4026 * This is because some failed devices may only affect one
4027 * of the two sections, and some non-in_sync devices may
4028 * be insync in the section most affected by failed devices.
4029 */
4030static int calc_degraded(struct r10conf *conf)
4031{
4032 int degraded, degraded2;
4033 int i;
4034
4035 rcu_read_lock();
4036 degraded = 0;
4037 /* 'prev' section first */
4038 for (i = 0; i < conf->prev.raid_disks; i++) {
4039 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
4040 if (!rdev || test_bit(Faulty, &rdev->flags))
4041 degraded++;
4042 else if (!test_bit(In_sync, &rdev->flags))
4043 /* When we can reduce the number of devices in
4044 * an array, this might not contribute to
4045 * 'degraded'. It does now.
4046 */
4047 degraded++;
4048 }
4049 rcu_read_unlock();
4050 if (conf->geo.raid_disks == conf->prev.raid_disks)
4051 return degraded;
4052 rcu_read_lock();
4053 degraded2 = 0;
4054 for (i = 0; i < conf->geo.raid_disks; i++) {
4055 struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
4056 if (!rdev || test_bit(Faulty, &rdev->flags))
4057 degraded2++;
4058 else if (!test_bit(In_sync, &rdev->flags)) {
4059 /* If reshape is increasing the number of devices,
4060 * this section has already been recovered, so
4061 * it doesn't contribute to degraded.
4062 * else it does.
4063 */
4064 if (conf->geo.raid_disks <= conf->prev.raid_disks)
4065 degraded2++;
4066 }
4067 }
4068 rcu_read_unlock();
4069 if (degraded2 > degraded)
4070 return degraded2;
4071 return degraded;
4072}
4073
4074static int raid10_start_reshape(struct mddev *mddev)
4075{
4076 /* A 'reshape' has been requested. This commits
4077 * the various 'new' fields and sets MD_RECOVER_RESHAPE
4078 * This also checks if there are enough spares and adds them
4079 * to the array.
4080 * We currently require enough spares to make the final
4081 * array non-degraded. We also require that the difference
4082 * between old and new data_offset - on each device - is
4083 * enough that we never risk over-writing.
4084 */
4085
4086 unsigned long before_length, after_length;
4087 sector_t min_offset_diff = 0;
4088 int first = 1;
4089 struct geom new;
4090 struct r10conf *conf = mddev->private;
4091 struct md_rdev *rdev;
4092 int spares = 0;
bb63a701 4093 int ret;
3ea7daa5
N
4094
4095 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
4096 return -EBUSY;
4097
4098 if (setup_geo(&new, mddev, geo_start) != conf->copies)
4099 return -EINVAL;
4100
4101 before_length = ((1 << conf->prev.chunk_shift) *
4102 conf->prev.far_copies);
4103 after_length = ((1 << conf->geo.chunk_shift) *
4104 conf->geo.far_copies);
4105
4106 rdev_for_each(rdev, mddev) {
4107 if (!test_bit(In_sync, &rdev->flags)
4108 && !test_bit(Faulty, &rdev->flags))
4109 spares++;
4110 if (rdev->raid_disk >= 0) {
4111 long long diff = (rdev->new_data_offset
4112 - rdev->data_offset);
4113 if (!mddev->reshape_backwards)
4114 diff = -diff;
4115 if (diff < 0)
4116 diff = 0;
4117 if (first || diff < min_offset_diff)
4118 min_offset_diff = diff;
4119 }
4120 }
4121
4122 if (max(before_length, after_length) > min_offset_diff)
4123 return -EINVAL;
4124
4125 if (spares < mddev->delta_disks)
4126 return -EINVAL;
4127
4128 conf->offset_diff = min_offset_diff;
4129 spin_lock_irq(&conf->device_lock);
4130 if (conf->mirrors_new) {
4131 memcpy(conf->mirrors_new, conf->mirrors,
dc280d98 4132 sizeof(struct raid10_info)*conf->prev.raid_disks);
3ea7daa5
N
4133 smp_mb();
4134 kfree(conf->mirrors_old); /* FIXME and elsewhere */
4135 conf->mirrors_old = conf->mirrors;
4136 conf->mirrors = conf->mirrors_new;
4137 conf->mirrors_new = NULL;
4138 }
4139 setup_geo(&conf->geo, mddev, geo_start);
4140 smp_mb();
4141 if (mddev->reshape_backwards) {
4142 sector_t size = raid10_size(mddev, 0, 0);
4143 if (size < mddev->array_sectors) {
4144 spin_unlock_irq(&conf->device_lock);
4145 printk(KERN_ERR "md/raid10:%s: array size must be reduce before number of disks\n",
4146 mdname(mddev));
4147 return -EINVAL;
4148 }
4149 mddev->resync_max_sectors = size;
4150 conf->reshape_progress = size;
4151 } else
4152 conf->reshape_progress = 0;
4153 spin_unlock_irq(&conf->device_lock);
4154
bb63a701
N
4155 if (mddev->delta_disks && mddev->bitmap) {
4156 ret = bitmap_resize(mddev->bitmap,
4157 raid10_size(mddev, 0,
4158 conf->geo.raid_disks),
4159 0, 0);
4160 if (ret)
4161 goto abort;
4162 }
3ea7daa5
N
4163 if (mddev->delta_disks > 0) {
4164 rdev_for_each(rdev, mddev)
4165 if (rdev->raid_disk < 0 &&
4166 !test_bit(Faulty, &rdev->flags)) {
4167 if (raid10_add_disk(mddev, rdev) == 0) {
4168 if (rdev->raid_disk >=
4169 conf->prev.raid_disks)
4170 set_bit(In_sync, &rdev->flags);
4171 else
4172 rdev->recovery_offset = 0;
4173
4174 if (sysfs_link_rdev(mddev, rdev))
4175 /* Failure here is OK */;
4176 }
4177 } else if (rdev->raid_disk >= conf->prev.raid_disks
4178 && !test_bit(Faulty, &rdev->flags)) {
4179 /* This is a spare that was manually added */
4180 set_bit(In_sync, &rdev->flags);
4181 }
4182 }
4183 /* When a reshape changes the number of devices,
4184 * ->degraded is measured against the larger of the
4185 * pre and post numbers.
4186 */
4187 spin_lock_irq(&conf->device_lock);
4188 mddev->degraded = calc_degraded(conf);
4189 spin_unlock_irq(&conf->device_lock);
4190 mddev->raid_disks = conf->geo.raid_disks;
4191 mddev->reshape_position = conf->reshape_progress;
4192 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4193
4194 clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4195 clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
4196 set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
4197 set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
4198
4199 mddev->sync_thread = md_register_thread(md_do_sync, mddev,
4200 "reshape");
4201 if (!mddev->sync_thread) {
bb63a701
N
4202 ret = -EAGAIN;
4203 goto abort;
3ea7daa5
N
4204 }
4205 conf->reshape_checkpoint = jiffies;
4206 md_wakeup_thread(mddev->sync_thread);
4207 md_new_event(mddev);
4208 return 0;
bb63a701
N
4209
4210abort:
4211 mddev->recovery = 0;
4212 spin_lock_irq(&conf->device_lock);
4213 conf->geo = conf->prev;
4214 mddev->raid_disks = conf->geo.raid_disks;
4215 rdev_for_each(rdev, mddev)
4216 rdev->new_data_offset = rdev->data_offset;
4217 smp_wmb();
4218 conf->reshape_progress = MaxSector;
4219 mddev->reshape_position = MaxSector;
4220 spin_unlock_irq(&conf->device_lock);
4221 return ret;
3ea7daa5
N
4222}
4223
4224/* Calculate the last device-address that could contain
4225 * any block from the chunk that includes the array-address 's'
4226 * and report the next address.
4227 * i.e. the address returned will be chunk-aligned and after
4228 * any data that is in the chunk containing 's'.
4229 */
4230static sector_t last_dev_address(sector_t s, struct geom *geo)
4231{
4232 s = (s | geo->chunk_mask) + 1;
4233 s >>= geo->chunk_shift;
4234 s *= geo->near_copies;
4235 s = DIV_ROUND_UP_SECTOR_T(s, geo->raid_disks);
4236 s *= geo->far_copies;
4237 s <<= geo->chunk_shift;
4238 return s;
4239}
4240
4241/* Calculate the first device-address that could contain
4242 * any block from the chunk that includes the array-address 's'.
4243 * This too will be the start of a chunk
4244 */
4245static sector_t first_dev_address(sector_t s, struct geom *geo)
4246{
4247 s >>= geo->chunk_shift;
4248 s *= geo->near_copies;
4249 sector_div(s, geo->raid_disks);
4250 s *= geo->far_copies;
4251 s <<= geo->chunk_shift;
4252 return s;
4253}
4254
4255static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr,
4256 int *skipped)
4257{
4258 /* We simply copy at most one chunk (smallest of old and new)
4259 * at a time, possibly less if that exceeds RESYNC_PAGES,
4260 * or we hit a bad block or something.
4261 * This might mean we pause for normal IO in the middle of
4262 * a chunk, but that is not a problem was mddev->reshape_position
4263 * can record any location.
4264 *
4265 * If we will want to write to a location that isn't
4266 * yet recorded as 'safe' (i.e. in metadata on disk) then
4267 * we need to flush all reshape requests and update the metadata.
4268 *
4269 * When reshaping forwards (e.g. to more devices), we interpret
4270 * 'safe' as the earliest block which might not have been copied
4271 * down yet. We divide this by previous stripe size and multiply
4272 * by previous stripe length to get lowest device offset that we
4273 * cannot write to yet.
4274 * We interpret 'sector_nr' as an address that we want to write to.
4275 * From this we use last_device_address() to find where we might
4276 * write to, and first_device_address on the 'safe' position.
4277 * If this 'next' write position is after the 'safe' position,
4278 * we must update the metadata to increase the 'safe' position.
4279 *
4280 * When reshaping backwards, we round in the opposite direction
4281 * and perform the reverse test: next write position must not be
4282 * less than current safe position.
4283 *
4284 * In all this the minimum difference in data offsets
4285 * (conf->offset_diff - always positive) allows a bit of slack,
4286 * so next can be after 'safe', but not by more than offset_disk
4287 *
4288 * We need to prepare all the bios here before we start any IO
4289 * to ensure the size we choose is acceptable to all devices.
4290 * The means one for each copy for write-out and an extra one for
4291 * read-in.
4292 * We store the read-in bio in ->master_bio and the others in
4293 * ->devs[x].bio and ->devs[x].repl_bio.
4294 */
4295 struct r10conf *conf = mddev->private;
4296 struct r10bio *r10_bio;
4297 sector_t next, safe, last;
4298 int max_sectors;
4299 int nr_sectors;
4300 int s;
4301 struct md_rdev *rdev;
4302 int need_flush = 0;
4303 struct bio *blist;
4304 struct bio *bio, *read_bio;
4305 int sectors_done = 0;
4306
4307 if (sector_nr == 0) {
4308 /* If restarting in the middle, skip the initial sectors */
4309 if (mddev->reshape_backwards &&
4310 conf->reshape_progress < raid10_size(mddev, 0, 0)) {
4311 sector_nr = (raid10_size(mddev, 0, 0)
4312 - conf->reshape_progress);
4313 } else if (!mddev->reshape_backwards &&
4314 conf->reshape_progress > 0)
4315 sector_nr = conf->reshape_progress;
4316 if (sector_nr) {
4317 mddev->curr_resync_completed = sector_nr;
4318 sysfs_notify(&mddev->kobj, NULL, "sync_completed");
4319 *skipped = 1;
4320 return sector_nr;
4321 }
4322 }
4323
4324 /* We don't use sector_nr to track where we are up to
4325 * as that doesn't work well for ->reshape_backwards.
4326 * So just use ->reshape_progress.
4327 */
4328 if (mddev->reshape_backwards) {
4329 /* 'next' is the earliest device address that we might
4330 * write to for this chunk in the new layout
4331 */
4332 next = first_dev_address(conf->reshape_progress - 1,
4333 &conf->geo);
4334
4335 /* 'safe' is the last device address that we might read from
4336 * in the old layout after a restart
4337 */
4338 safe = last_dev_address(conf->reshape_safe - 1,
4339 &conf->prev);
4340
4341 if (next + conf->offset_diff < safe)
4342 need_flush = 1;
4343
4344 last = conf->reshape_progress - 1;
4345 sector_nr = last & ~(sector_t)(conf->geo.chunk_mask
4346 & conf->prev.chunk_mask);
4347 if (sector_nr + RESYNC_BLOCK_SIZE/512 < last)
4348 sector_nr = last + 1 - RESYNC_BLOCK_SIZE/512;
4349 } else {
4350 /* 'next' is after the last device address that we
4351 * might write to for this chunk in the new layout
4352 */
4353 next = last_dev_address(conf->reshape_progress, &conf->geo);
4354
4355 /* 'safe' is the earliest device address that we might
4356 * read from in the old layout after a restart
4357 */
4358 safe = first_dev_address(conf->reshape_safe, &conf->prev);
4359
4360 /* Need to update metadata if 'next' might be beyond 'safe'
4361 * as that would possibly corrupt data
4362 */
4363 if (next > safe + conf->offset_diff)
4364 need_flush = 1;
4365
4366 sector_nr = conf->reshape_progress;
4367 last = sector_nr | (conf->geo.chunk_mask
4368 & conf->prev.chunk_mask);
4369
4370 if (sector_nr + RESYNC_BLOCK_SIZE/512 <= last)
4371 last = sector_nr + RESYNC_BLOCK_SIZE/512 - 1;
4372 }
4373
4374 if (need_flush ||
4375 time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
4376 /* Need to update reshape_position in metadata */
4377 wait_barrier(conf);
4378 mddev->reshape_position = conf->reshape_progress;
4379 if (mddev->reshape_backwards)
4380 mddev->curr_resync_completed = raid10_size(mddev, 0, 0)
4381 - conf->reshape_progress;
4382 else
4383 mddev->curr_resync_completed = conf->reshape_progress;
4384 conf->reshape_checkpoint = jiffies;
4385 set_bit(MD_CHANGE_DEVS, &mddev->flags);
4386 md_wakeup_thread(mddev->thread);
4387 wait_event(mddev->sb_wait, mddev->flags == 0 ||
4388 kthread_should_stop());
4389 conf->reshape_safe = mddev->reshape_position;
4390 allow_barrier(conf);
4391 }
4392
4393read_more:
4394 /* Now schedule reads for blocks from sector_nr to last */
4395 r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO);
4396 raise_barrier(conf, sectors_done != 0);
4397 atomic_set(&r10_bio->remaining, 0);
4398 r10_bio->mddev = mddev;
4399 r10_bio->sector = sector_nr;
4400 set_bit(R10BIO_IsReshape, &r10_bio->state);
4401 r10_bio->sectors = last - sector_nr + 1;
4402 rdev = read_balance(conf, r10_bio, &max_sectors);
4403 BUG_ON(!test_bit(R10BIO_Previous, &r10_bio->state));
4404
4405 if (!rdev) {
4406 /* Cannot read from here, so need to record bad blocks
4407 * on all the target devices.
4408 */
4409 // FIXME
4410 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
4411 return sectors_done;
4412 }
4413
4414 read_bio = bio_alloc_mddev(GFP_KERNEL, RESYNC_PAGES, mddev);
4415
4416 read_bio->bi_bdev = rdev->bdev;
4417 read_bio->bi_sector = (r10_bio->devs[r10_bio->read_slot].addr
4418 + rdev->data_offset);
4419 read_bio->bi_private = r10_bio;
4420 read_bio->bi_end_io = end_sync_read;
4421 read_bio->bi_rw = READ;
4422 read_bio->bi_flags &= ~(BIO_POOL_MASK - 1);
4423 read_bio->bi_flags |= 1 << BIO_UPTODATE;
4424 read_bio->bi_vcnt = 0;
3ea7daa5
N
4425 read_bio->bi_size = 0;
4426 r10_bio->master_bio = read_bio;
4427 r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum;
4428
4429 /* Now find the locations in the new layout */
4430 __raid10_find_phys(&conf->geo, r10_bio);
4431
4432 blist = read_bio;
4433 read_bio->bi_next = NULL;
4434
4435 for (s = 0; s < conf->copies*2; s++) {
4436 struct bio *b;
4437 int d = r10_bio->devs[s/2].devnum;
4438 struct md_rdev *rdev2;
4439 if (s&1) {
4440 rdev2 = conf->mirrors[d].replacement;
4441 b = r10_bio->devs[s/2].repl_bio;
4442 } else {
4443 rdev2 = conf->mirrors[d].rdev;
4444 b = r10_bio->devs[s/2].bio;
4445 }
4446 if (!rdev2 || test_bit(Faulty, &rdev2->flags))
4447 continue;
8be185f2
KO
4448
4449 bio_reset(b);
3ea7daa5
N
4450 b->bi_bdev = rdev2->bdev;
4451 b->bi_sector = r10_bio->devs[s/2].addr + rdev2->new_data_offset;
4452 b->bi_private = r10_bio;
4453 b->bi_end_io = end_reshape_write;
4454 b->bi_rw = WRITE;
3ea7daa5 4455 b->bi_next = blist;
3ea7daa5
N
4456 blist = b;
4457 }
4458
4459 /* Now add as many pages as possible to all of these bios. */
4460
4461 nr_sectors = 0;
4462 for (s = 0 ; s < max_sectors; s += PAGE_SIZE >> 9) {
4463 struct page *page = r10_bio->devs[0].bio->bi_io_vec[s/(PAGE_SIZE>>9)].bv_page;
4464 int len = (max_sectors - s) << 9;
4465 if (len > PAGE_SIZE)
4466 len = PAGE_SIZE;
4467 for (bio = blist; bio ; bio = bio->bi_next) {
4468 struct bio *bio2;
4469 if (bio_add_page(bio, page, len, 0))
4470 continue;
4471
4472 /* Didn't fit, must stop */
4473 for (bio2 = blist;
4474 bio2 && bio2 != bio;
4475 bio2 = bio2->bi_next) {
4476 /* Remove last page from this bio */
4477 bio2->bi_vcnt--;
4478 bio2->bi_size -= len;
4479 bio2->bi_flags &= ~(1<<BIO_SEG_VALID);
4480 }
4481 goto bio_full;
4482 }
4483 sector_nr += len >> 9;
4484 nr_sectors += len >> 9;
4485 }
4486bio_full:
4487 r10_bio->sectors = nr_sectors;
4488
4489 /* Now submit the read */
4490 md_sync_acct(read_bio->bi_bdev, r10_bio->sectors);
4491 atomic_inc(&r10_bio->remaining);
4492 read_bio->bi_next = NULL;
4493 generic_make_request(read_bio);
4494 sector_nr += nr_sectors;
4495 sectors_done += nr_sectors;
4496 if (sector_nr <= last)
4497 goto read_more;
4498
4499 /* Now that we have done the whole section we can
4500 * update reshape_progress
4501 */
4502 if (mddev->reshape_backwards)
4503 conf->reshape_progress -= sectors_done;
4504 else
4505 conf->reshape_progress += sectors_done;
4506
4507 return sectors_done;
4508}
4509
4510static void end_reshape_request(struct r10bio *r10_bio);
4511static int handle_reshape_read_error(struct mddev *mddev,
4512 struct r10bio *r10_bio);
4513static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio)
4514{
4515 /* Reshape read completed. Hopefully we have a block
4516 * to write out.
4517 * If we got a read error then we do sync 1-page reads from
4518 * elsewhere until we find the data - or give up.
4519 */
4520 struct r10conf *conf = mddev->private;
4521 int s;
4522
4523 if (!test_bit(R10BIO_Uptodate, &r10_bio->state))
4524 if (handle_reshape_read_error(mddev, r10_bio) < 0) {
4525 /* Reshape has been aborted */
4526 md_done_sync(mddev, r10_bio->sectors, 0);
4527 return;
4528 }
4529
4530 /* We definitely have the data in the pages, schedule the
4531 * writes.
4532 */
4533 atomic_set(&r10_bio->remaining, 1);
4534 for (s = 0; s < conf->copies*2; s++) {
4535 struct bio *b;
4536 int d = r10_bio->devs[s/2].devnum;
4537 struct md_rdev *rdev;
4538 if (s&1) {
4539 rdev = conf->mirrors[d].replacement;
4540 b = r10_bio->devs[s/2].repl_bio;
4541 } else {
4542 rdev = conf->mirrors[d].rdev;
4543 b = r10_bio->devs[s/2].bio;
4544 }
4545 if (!rdev || test_bit(Faulty, &rdev->flags))
4546 continue;
4547 atomic_inc(&rdev->nr_pending);
4548 md_sync_acct(b->bi_bdev, r10_bio->sectors);
4549 atomic_inc(&r10_bio->remaining);
4550 b->bi_next = NULL;
4551 generic_make_request(b);
4552 }
4553 end_reshape_request(r10_bio);
4554}
4555
4556static void end_reshape(struct r10conf *conf)
4557{
4558 if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery))
4559 return;
4560
4561 spin_lock_irq(&conf->device_lock);
4562 conf->prev = conf->geo;
4563 md_finish_reshape(conf->mddev);
4564 smp_wmb();
4565 conf->reshape_progress = MaxSector;
4566 spin_unlock_irq(&conf->device_lock);
4567
4568 /* read-ahead size must cover two whole stripes, which is
4569 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
4570 */
4571 if (conf->mddev->queue) {
4572 int stripe = conf->geo.raid_disks *
4573 ((conf->mddev->chunk_sectors << 9) / PAGE_SIZE);
4574 stripe /= conf->geo.near_copies;
4575 if (conf->mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
4576 conf->mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
4577 }
4578 conf->fullsync = 0;
4579}
4580
4581
4582static int handle_reshape_read_error(struct mddev *mddev,
4583 struct r10bio *r10_bio)
4584{
4585 /* Use sync reads to get the blocks from somewhere else */
4586 int sectors = r10_bio->sectors;
3ea7daa5 4587 struct r10conf *conf = mddev->private;
e0ee7785
N
4588 struct {
4589 struct r10bio r10_bio;
4590 struct r10dev devs[conf->copies];
4591 } on_stack;
4592 struct r10bio *r10b = &on_stack.r10_bio;
3ea7daa5
N
4593 int slot = 0;
4594 int idx = 0;
4595 struct bio_vec *bvec = r10_bio->master_bio->bi_io_vec;
4596
e0ee7785
N
4597 r10b->sector = r10_bio->sector;
4598 __raid10_find_phys(&conf->prev, r10b);
3ea7daa5
N
4599
4600 while (sectors) {
4601 int s = sectors;
4602 int success = 0;
4603 int first_slot = slot;
4604
4605 if (s > (PAGE_SIZE >> 9))
4606 s = PAGE_SIZE >> 9;
4607
4608 while (!success) {
e0ee7785 4609 int d = r10b->devs[slot].devnum;
3ea7daa5
N
4610 struct md_rdev *rdev = conf->mirrors[d].rdev;
4611 sector_t addr;
4612 if (rdev == NULL ||
4613 test_bit(Faulty, &rdev->flags) ||
4614 !test_bit(In_sync, &rdev->flags))
4615 goto failed;
4616
e0ee7785 4617 addr = r10b->devs[slot].addr + idx * PAGE_SIZE;
3ea7daa5
N
4618 success = sync_page_io(rdev,
4619 addr,
4620 s << 9,
4621 bvec[idx].bv_page,
4622 READ, false);
4623 if (success)
4624 break;
4625 failed:
4626 slot++;
4627 if (slot >= conf->copies)
4628 slot = 0;
4629 if (slot == first_slot)
4630 break;
4631 }
4632 if (!success) {
4633 /* couldn't read this block, must give up */
4634 set_bit(MD_RECOVERY_INTR,
4635 &mddev->recovery);
4636 return -EIO;
4637 }
4638 sectors -= s;
4639 idx++;
4640 }
4641 return 0;
4642}
4643
4644static void end_reshape_write(struct bio *bio, int error)
4645{
4646 int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
4647 struct r10bio *r10_bio = bio->bi_private;
4648 struct mddev *mddev = r10_bio->mddev;
4649 struct r10conf *conf = mddev->private;
4650 int d;
4651 int slot;
4652 int repl;
4653 struct md_rdev *rdev = NULL;
4654
4655 d = find_bio_disk(conf, r10_bio, bio, &slot, &repl);
4656 if (repl)
4657 rdev = conf->mirrors[d].replacement;
4658 if (!rdev) {
4659 smp_mb();
4660 rdev = conf->mirrors[d].rdev;
4661 }
4662
4663 if (!uptodate) {
4664 /* FIXME should record badblock */
4665 md_error(mddev, rdev);
4666 }
4667
4668 rdev_dec_pending(rdev, mddev);
4669 end_reshape_request(r10_bio);
4670}
4671
4672static void end_reshape_request(struct r10bio *r10_bio)
4673{
4674 if (!atomic_dec_and_test(&r10_bio->remaining))
4675 return;
4676 md_done_sync(r10_bio->mddev, r10_bio->sectors, 1);
4677 bio_put(r10_bio->master_bio);
4678 put_buf(r10_bio);
4679}
4680
4681static void raid10_finish_reshape(struct mddev *mddev)
4682{
4683 struct r10conf *conf = mddev->private;
4684
4685 if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
4686 return;
4687
4688 if (mddev->delta_disks > 0) {
4689 sector_t size = raid10_size(mddev, 0, 0);
4690 md_set_array_sectors(mddev, size);
4691 if (mddev->recovery_cp > mddev->resync_max_sectors) {
4692 mddev->recovery_cp = mddev->resync_max_sectors;
4693 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
4694 }
4695 mddev->resync_max_sectors = size;
4696 set_capacity(mddev->gendisk, mddev->array_sectors);
4697 revalidate_disk(mddev->gendisk);
63aced61
N
4698 } else {
4699 int d;
4700 for (d = conf->geo.raid_disks ;
4701 d < conf->geo.raid_disks - mddev->delta_disks;
4702 d++) {
4703 struct md_rdev *rdev = conf->mirrors[d].rdev;
4704 if (rdev)
4705 clear_bit(In_sync, &rdev->flags);
4706 rdev = conf->mirrors[d].replacement;
4707 if (rdev)
4708 clear_bit(In_sync, &rdev->flags);
4709 }
3ea7daa5
N
4710 }
4711 mddev->layout = mddev->new_layout;
4712 mddev->chunk_sectors = 1 << conf->geo.chunk_shift;
4713 mddev->reshape_position = MaxSector;
4714 mddev->delta_disks = 0;
4715 mddev->reshape_backwards = 0;
4716}
4717
84fc4b56 4718static struct md_personality raid10_personality =
1da177e4
LT
4719{
4720 .name = "raid10",
2604b703 4721 .level = 10,
1da177e4
LT
4722 .owner = THIS_MODULE,
4723 .make_request = make_request,
4724 .run = run,
4725 .stop = stop,
4726 .status = status,
4727 .error_handler = error,
4728 .hot_add_disk = raid10_add_disk,
4729 .hot_remove_disk= raid10_remove_disk,
4730 .spare_active = raid10_spare_active,
4731 .sync_request = sync_request,
6cce3b23 4732 .quiesce = raid10_quiesce,
80c3a6ce 4733 .size = raid10_size,
006a09a0 4734 .resize = raid10_resize,
dab8b292 4735 .takeover = raid10_takeover,
3ea7daa5
N
4736 .check_reshape = raid10_check_reshape,
4737 .start_reshape = raid10_start_reshape,
4738 .finish_reshape = raid10_finish_reshape,
1da177e4
LT
4739};
4740
4741static int __init raid_init(void)
4742{
2604b703 4743 return register_md_personality(&raid10_personality);
1da177e4
LT
4744}
4745
4746static void raid_exit(void)
4747{
2604b703 4748 unregister_md_personality(&raid10_personality);
1da177e4
LT
4749}
4750
4751module_init(raid_init);
4752module_exit(raid_exit);
4753MODULE_LICENSE("GPL");
0efb9e61 4754MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD");
1da177e4 4755MODULE_ALIAS("md-personality-9"); /* RAID10 */
d9d166c2 4756MODULE_ALIAS("md-raid10");
2604b703 4757MODULE_ALIAS("md-level-10");
34db0cd6
N
4758
4759module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);
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