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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> |
bff61975 | 24 | #include <linux/seq_file.h> |
8bda470e | 25 | #include <linux/ratelimit.h> |
43b2e5d8 | 26 | #include "md.h" |
ef740c37 | 27 | #include "raid10.h" |
dab8b292 | 28 | #include "raid0.h" |
ef740c37 | 29 | #include "bitmap.h" |
1da177e4 LT |
30 | |
31 | /* | |
32 | * RAID10 provides a combination of RAID0 and RAID1 functionality. | |
33 | * The layout of data is defined by | |
34 | * chunk_size | |
35 | * raid_disks | |
36 | * near_copies (stored in low byte of layout) | |
37 | * far_copies (stored in second byte of layout) | |
c93983bf | 38 | * far_offset (stored in bit 16 of layout ) |
1da177e4 LT |
39 | * |
40 | * The data to be stored is divided into chunks using chunksize. | |
41 | * Each device is divided into far_copies sections. | |
42 | * In each section, chunks are laid out in a style similar to raid0, but | |
43 | * near_copies copies of each chunk is stored (each on a different drive). | |
44 | * The starting device for each section is offset near_copies from the starting | |
45 | * device of the previous section. | |
c93983bf | 46 | * Thus they are (near_copies*far_copies) of each chunk, and each is on a different |
1da177e4 LT |
47 | * drive. |
48 | * near_copies and far_copies must be at least one, and their product is at most | |
49 | * raid_disks. | |
c93983bf N |
50 | * |
51 | * If far_offset is true, then the far_copies are handled a bit differently. | |
52 | * The copies are still in different stripes, but instead of be very far apart | |
53 | * on disk, there are adjacent stripes. | |
1da177e4 LT |
54 | */ |
55 | ||
56 | /* | |
57 | * Number of guaranteed r10bios in case of extreme VM load: | |
58 | */ | |
59 | #define NR_RAID10_BIOS 256 | |
60 | ||
0a27ec96 N |
61 | static void allow_barrier(conf_t *conf); |
62 | static void lower_barrier(conf_t *conf); | |
63 | ||
dd0fc66f | 64 | static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
65 | { |
66 | conf_t *conf = data; | |
1da177e4 LT |
67 | int size = offsetof(struct r10bio_s, devs[conf->copies]); |
68 | ||
69 | /* allocate a r10bio with room for raid_disks entries in the bios array */ | |
7eaceacc | 70 | return kzalloc(size, gfp_flags); |
1da177e4 LT |
71 | } |
72 | ||
73 | static void r10bio_pool_free(void *r10_bio, void *data) | |
74 | { | |
75 | kfree(r10_bio); | |
76 | } | |
77 | ||
0310fa21 | 78 | /* Maximum size of each resync request */ |
1da177e4 | 79 | #define RESYNC_BLOCK_SIZE (64*1024) |
1da177e4 | 80 | #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) |
0310fa21 N |
81 | /* amount of memory to reserve for resync requests */ |
82 | #define RESYNC_WINDOW (1024*1024) | |
83 | /* maximum number of concurrent requests, memory permitting */ | |
84 | #define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE) | |
1da177e4 LT |
85 | |
86 | /* | |
87 | * When performing a resync, we need to read and compare, so | |
88 | * we need as many pages are there are copies. | |
89 | * When performing a recovery, we need 2 bios, one for read, | |
90 | * one for write (we recover only one drive per r10buf) | |
91 | * | |
92 | */ | |
dd0fc66f | 93 | static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
94 | { |
95 | conf_t *conf = data; | |
96 | struct page *page; | |
97 | r10bio_t *r10_bio; | |
98 | struct bio *bio; | |
99 | int i, j; | |
100 | int nalloc; | |
101 | ||
102 | r10_bio = r10bio_pool_alloc(gfp_flags, conf); | |
7eaceacc | 103 | if (!r10_bio) |
1da177e4 | 104 | return NULL; |
1da177e4 LT |
105 | |
106 | if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery)) | |
107 | nalloc = conf->copies; /* resync */ | |
108 | else | |
109 | nalloc = 2; /* recovery */ | |
110 | ||
111 | /* | |
112 | * Allocate bios. | |
113 | */ | |
114 | for (j = nalloc ; j-- ; ) { | |
6746557f | 115 | bio = bio_kmalloc(gfp_flags, RESYNC_PAGES); |
1da177e4 LT |
116 | if (!bio) |
117 | goto out_free_bio; | |
118 | r10_bio->devs[j].bio = bio; | |
119 | } | |
120 | /* | |
121 | * Allocate RESYNC_PAGES data pages and attach them | |
122 | * where needed. | |
123 | */ | |
124 | for (j = 0 ; j < nalloc; j++) { | |
125 | bio = r10_bio->devs[j].bio; | |
126 | for (i = 0; i < RESYNC_PAGES; i++) { | |
c65060ad NK |
127 | if (j == 1 && !test_bit(MD_RECOVERY_SYNC, |
128 | &conf->mddev->recovery)) { | |
129 | /* we can share bv_page's during recovery */ | |
130 | struct bio *rbio = r10_bio->devs[0].bio; | |
131 | page = rbio->bi_io_vec[i].bv_page; | |
132 | get_page(page); | |
133 | } else | |
134 | page = alloc_page(gfp_flags); | |
1da177e4 LT |
135 | if (unlikely(!page)) |
136 | goto out_free_pages; | |
137 | ||
138 | bio->bi_io_vec[i].bv_page = page; | |
139 | } | |
140 | } | |
141 | ||
142 | return r10_bio; | |
143 | ||
144 | out_free_pages: | |
145 | for ( ; i > 0 ; i--) | |
1345b1d8 | 146 | safe_put_page(bio->bi_io_vec[i-1].bv_page); |
1da177e4 LT |
147 | while (j--) |
148 | for (i = 0; i < RESYNC_PAGES ; i++) | |
1345b1d8 | 149 | safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page); |
1da177e4 LT |
150 | j = -1; |
151 | out_free_bio: | |
152 | while ( ++j < nalloc ) | |
153 | bio_put(r10_bio->devs[j].bio); | |
154 | r10bio_pool_free(r10_bio, conf); | |
155 | return NULL; | |
156 | } | |
157 | ||
158 | static void r10buf_pool_free(void *__r10_bio, void *data) | |
159 | { | |
160 | int i; | |
161 | conf_t *conf = data; | |
162 | r10bio_t *r10bio = __r10_bio; | |
163 | int j; | |
164 | ||
165 | for (j=0; j < conf->copies; j++) { | |
166 | struct bio *bio = r10bio->devs[j].bio; | |
167 | if (bio) { | |
168 | for (i = 0; i < RESYNC_PAGES; i++) { | |
1345b1d8 | 169 | safe_put_page(bio->bi_io_vec[i].bv_page); |
1da177e4 LT |
170 | bio->bi_io_vec[i].bv_page = NULL; |
171 | } | |
172 | bio_put(bio); | |
173 | } | |
174 | } | |
175 | r10bio_pool_free(r10bio, conf); | |
176 | } | |
177 | ||
178 | static void put_all_bios(conf_t *conf, r10bio_t *r10_bio) | |
179 | { | |
180 | int i; | |
181 | ||
182 | for (i = 0; i < conf->copies; i++) { | |
183 | struct bio **bio = & r10_bio->devs[i].bio; | |
0eb3ff12 | 184 | if (*bio && *bio != IO_BLOCKED) |
1da177e4 LT |
185 | bio_put(*bio); |
186 | *bio = NULL; | |
187 | } | |
188 | } | |
189 | ||
858119e1 | 190 | static void free_r10bio(r10bio_t *r10_bio) |
1da177e4 | 191 | { |
070ec55d | 192 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 LT |
193 | |
194 | /* | |
195 | * Wake up any possible resync thread that waits for the device | |
196 | * to go idle. | |
197 | */ | |
0a27ec96 | 198 | allow_barrier(conf); |
1da177e4 LT |
199 | |
200 | put_all_bios(conf, r10_bio); | |
201 | mempool_free(r10_bio, conf->r10bio_pool); | |
202 | } | |
203 | ||
858119e1 | 204 | static void put_buf(r10bio_t *r10_bio) |
1da177e4 | 205 | { |
070ec55d | 206 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 LT |
207 | |
208 | mempool_free(r10_bio, conf->r10buf_pool); | |
209 | ||
0a27ec96 | 210 | lower_barrier(conf); |
1da177e4 LT |
211 | } |
212 | ||
213 | static void reschedule_retry(r10bio_t *r10_bio) | |
214 | { | |
215 | unsigned long flags; | |
216 | mddev_t *mddev = r10_bio->mddev; | |
070ec55d | 217 | conf_t *conf = mddev->private; |
1da177e4 LT |
218 | |
219 | spin_lock_irqsave(&conf->device_lock, flags); | |
220 | list_add(&r10_bio->retry_list, &conf->retry_list); | |
4443ae10 | 221 | conf->nr_queued ++; |
1da177e4 LT |
222 | spin_unlock_irqrestore(&conf->device_lock, flags); |
223 | ||
388667be AJ |
224 | /* wake up frozen array... */ |
225 | wake_up(&conf->wait_barrier); | |
226 | ||
1da177e4 LT |
227 | md_wakeup_thread(mddev->thread); |
228 | } | |
229 | ||
230 | /* | |
231 | * raid_end_bio_io() is called when we have finished servicing a mirrored | |
232 | * operation and are ready to return a success/failure code to the buffer | |
233 | * cache layer. | |
234 | */ | |
235 | static void raid_end_bio_io(r10bio_t *r10_bio) | |
236 | { | |
237 | struct bio *bio = r10_bio->master_bio; | |
238 | ||
6712ecf8 | 239 | bio_endio(bio, |
1da177e4 LT |
240 | test_bit(R10BIO_Uptodate, &r10_bio->state) ? 0 : -EIO); |
241 | free_r10bio(r10_bio); | |
242 | } | |
243 | ||
244 | /* | |
245 | * Update disk head position estimator based on IRQ completion info. | |
246 | */ | |
247 | static inline void update_head_pos(int slot, r10bio_t *r10_bio) | |
248 | { | |
070ec55d | 249 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 LT |
250 | |
251 | conf->mirrors[r10_bio->devs[slot].devnum].head_position = | |
252 | r10_bio->devs[slot].addr + (r10_bio->sectors); | |
253 | } | |
254 | ||
778ca018 NK |
255 | /* |
256 | * Find the disk number which triggered given bio | |
257 | */ | |
258 | static int find_bio_disk(conf_t *conf, r10bio_t *r10_bio, struct bio *bio) | |
259 | { | |
260 | int slot; | |
261 | ||
262 | for (slot = 0; slot < conf->copies; slot++) | |
263 | if (r10_bio->devs[slot].bio == bio) | |
264 | break; | |
265 | ||
266 | BUG_ON(slot == conf->copies); | |
267 | update_head_pos(slot, r10_bio); | |
268 | ||
269 | return r10_bio->devs[slot].devnum; | |
270 | } | |
271 | ||
6712ecf8 | 272 | static void raid10_end_read_request(struct bio *bio, int error) |
1da177e4 LT |
273 | { |
274 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
7b92813c | 275 | r10bio_t *r10_bio = bio->bi_private; |
1da177e4 | 276 | int slot, dev; |
070ec55d | 277 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 | 278 | |
1da177e4 LT |
279 | |
280 | slot = r10_bio->read_slot; | |
281 | dev = r10_bio->devs[slot].devnum; | |
282 | /* | |
283 | * this branch is our 'one mirror IO has finished' event handler: | |
284 | */ | |
4443ae10 N |
285 | update_head_pos(slot, r10_bio); |
286 | ||
287 | if (uptodate) { | |
1da177e4 LT |
288 | /* |
289 | * Set R10BIO_Uptodate in our master bio, so that | |
290 | * we will return a good error code to the higher | |
291 | * levels even if IO on some other mirrored buffer fails. | |
292 | * | |
293 | * The 'master' represents the composite IO operation to | |
294 | * user-side. So if something waits for IO, then it will | |
295 | * wait for the 'master' bio. | |
296 | */ | |
297 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
1da177e4 | 298 | raid_end_bio_io(r10_bio); |
7c4e06ff | 299 | rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev); |
4443ae10 | 300 | } else { |
1da177e4 | 301 | /* |
7c4e06ff | 302 | * oops, read error - keep the refcount on the rdev |
1da177e4 LT |
303 | */ |
304 | char b[BDEVNAME_SIZE]; | |
8bda470e CD |
305 | printk_ratelimited(KERN_ERR |
306 | "md/raid10:%s: %s: rescheduling sector %llu\n", | |
307 | mdname(conf->mddev), | |
308 | bdevname(conf->mirrors[dev].rdev->bdev, b), | |
309 | (unsigned long long)r10_bio->sector); | |
1da177e4 LT |
310 | reschedule_retry(r10_bio); |
311 | } | |
1da177e4 LT |
312 | } |
313 | ||
6712ecf8 | 314 | static void raid10_end_write_request(struct bio *bio, int error) |
1da177e4 LT |
315 | { |
316 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
7b92813c | 317 | r10bio_t *r10_bio = bio->bi_private; |
778ca018 | 318 | int dev; |
070ec55d | 319 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 | 320 | |
778ca018 | 321 | dev = find_bio_disk(conf, r10_bio, bio); |
1da177e4 LT |
322 | |
323 | /* | |
324 | * this branch is our 'one mirror IO has finished' event handler: | |
325 | */ | |
6cce3b23 | 326 | if (!uptodate) { |
1da177e4 | 327 | md_error(r10_bio->mddev, conf->mirrors[dev].rdev); |
6cce3b23 N |
328 | /* an I/O failed, we can't clear the bitmap */ |
329 | set_bit(R10BIO_Degraded, &r10_bio->state); | |
330 | } else | |
1da177e4 LT |
331 | /* |
332 | * Set R10BIO_Uptodate in our master bio, so that | |
333 | * we will return a good error code for to the higher | |
334 | * levels even if IO on some other mirrored buffer fails. | |
335 | * | |
336 | * The 'master' represents the composite IO operation to | |
337 | * user-side. So if something waits for IO, then it will | |
338 | * wait for the 'master' bio. | |
339 | */ | |
340 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
341 | ||
1da177e4 LT |
342 | /* |
343 | * | |
344 | * Let's see if all mirrored write operations have finished | |
345 | * already. | |
346 | */ | |
347 | if (atomic_dec_and_test(&r10_bio->remaining)) { | |
6cce3b23 N |
348 | /* clear the bitmap if all writes complete successfully */ |
349 | bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector, | |
350 | r10_bio->sectors, | |
351 | !test_bit(R10BIO_Degraded, &r10_bio->state), | |
352 | 0); | |
1da177e4 LT |
353 | md_write_end(r10_bio->mddev); |
354 | raid_end_bio_io(r10_bio); | |
355 | } | |
356 | ||
357 | rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev); | |
1da177e4 LT |
358 | } |
359 | ||
360 | ||
361 | /* | |
362 | * RAID10 layout manager | |
25985edc | 363 | * As well as the chunksize and raid_disks count, there are two |
1da177e4 LT |
364 | * parameters: near_copies and far_copies. |
365 | * near_copies * far_copies must be <= raid_disks. | |
366 | * Normally one of these will be 1. | |
367 | * If both are 1, we get raid0. | |
368 | * If near_copies == raid_disks, we get raid1. | |
369 | * | |
25985edc | 370 | * Chunks are laid out in raid0 style with near_copies copies of the |
1da177e4 LT |
371 | * first chunk, followed by near_copies copies of the next chunk and |
372 | * so on. | |
373 | * If far_copies > 1, then after 1/far_copies of the array has been assigned | |
374 | * as described above, we start again with a device offset of near_copies. | |
375 | * So we effectively have another copy of the whole array further down all | |
376 | * the drives, but with blocks on different drives. | |
377 | * With this layout, and block is never stored twice on the one device. | |
378 | * | |
379 | * raid10_find_phys finds the sector offset of a given virtual sector | |
c93983bf | 380 | * on each device that it is on. |
1da177e4 LT |
381 | * |
382 | * raid10_find_virt does the reverse mapping, from a device and a | |
383 | * sector offset to a virtual address | |
384 | */ | |
385 | ||
386 | static void raid10_find_phys(conf_t *conf, r10bio_t *r10bio) | |
387 | { | |
388 | int n,f; | |
389 | sector_t sector; | |
390 | sector_t chunk; | |
391 | sector_t stripe; | |
392 | int dev; | |
393 | ||
394 | int slot = 0; | |
395 | ||
396 | /* now calculate first sector/dev */ | |
397 | chunk = r10bio->sector >> conf->chunk_shift; | |
398 | sector = r10bio->sector & conf->chunk_mask; | |
399 | ||
400 | chunk *= conf->near_copies; | |
401 | stripe = chunk; | |
402 | dev = sector_div(stripe, conf->raid_disks); | |
c93983bf N |
403 | if (conf->far_offset) |
404 | stripe *= conf->far_copies; | |
1da177e4 LT |
405 | |
406 | sector += stripe << conf->chunk_shift; | |
407 | ||
408 | /* and calculate all the others */ | |
409 | for (n=0; n < conf->near_copies; n++) { | |
410 | int d = dev; | |
411 | sector_t s = sector; | |
412 | r10bio->devs[slot].addr = sector; | |
413 | r10bio->devs[slot].devnum = d; | |
414 | slot++; | |
415 | ||
416 | for (f = 1; f < conf->far_copies; f++) { | |
417 | d += conf->near_copies; | |
418 | if (d >= conf->raid_disks) | |
419 | d -= conf->raid_disks; | |
420 | s += conf->stride; | |
421 | r10bio->devs[slot].devnum = d; | |
422 | r10bio->devs[slot].addr = s; | |
423 | slot++; | |
424 | } | |
425 | dev++; | |
426 | if (dev >= conf->raid_disks) { | |
427 | dev = 0; | |
428 | sector += (conf->chunk_mask + 1); | |
429 | } | |
430 | } | |
431 | BUG_ON(slot != conf->copies); | |
432 | } | |
433 | ||
434 | static sector_t raid10_find_virt(conf_t *conf, sector_t sector, int dev) | |
435 | { | |
436 | sector_t offset, chunk, vchunk; | |
437 | ||
1da177e4 | 438 | offset = sector & conf->chunk_mask; |
c93983bf N |
439 | if (conf->far_offset) { |
440 | int fc; | |
441 | chunk = sector >> conf->chunk_shift; | |
442 | fc = sector_div(chunk, conf->far_copies); | |
443 | dev -= fc * conf->near_copies; | |
444 | if (dev < 0) | |
445 | dev += conf->raid_disks; | |
446 | } else { | |
64a742bc | 447 | while (sector >= conf->stride) { |
c93983bf N |
448 | sector -= conf->stride; |
449 | if (dev < conf->near_copies) | |
450 | dev += conf->raid_disks - conf->near_copies; | |
451 | else | |
452 | dev -= conf->near_copies; | |
453 | } | |
454 | chunk = sector >> conf->chunk_shift; | |
455 | } | |
1da177e4 LT |
456 | vchunk = chunk * conf->raid_disks + dev; |
457 | sector_div(vchunk, conf->near_copies); | |
458 | return (vchunk << conf->chunk_shift) + offset; | |
459 | } | |
460 | ||
461 | /** | |
462 | * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged | |
463 | * @q: request queue | |
cc371e66 | 464 | * @bvm: properties of new bio |
1da177e4 LT |
465 | * @biovec: the request that could be merged to it. |
466 | * | |
467 | * Return amount of bytes we can accept at this offset | |
468 | * If near_copies == raid_disk, there are no striping issues, | |
469 | * but in that case, the function isn't called at all. | |
470 | */ | |
cc371e66 AK |
471 | static int raid10_mergeable_bvec(struct request_queue *q, |
472 | struct bvec_merge_data *bvm, | |
473 | struct bio_vec *biovec) | |
1da177e4 LT |
474 | { |
475 | mddev_t *mddev = q->queuedata; | |
cc371e66 | 476 | sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); |
1da177e4 | 477 | int max; |
9d8f0363 | 478 | unsigned int chunk_sectors = mddev->chunk_sectors; |
cc371e66 | 479 | unsigned int bio_sectors = bvm->bi_size >> 9; |
1da177e4 LT |
480 | |
481 | max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; | |
482 | if (max < 0) max = 0; /* bio_add cannot handle a negative return */ | |
cc371e66 AK |
483 | if (max <= biovec->bv_len && bio_sectors == 0) |
484 | return biovec->bv_len; | |
1da177e4 LT |
485 | else |
486 | return max; | |
487 | } | |
488 | ||
489 | /* | |
490 | * This routine returns the disk from which the requested read should | |
491 | * be done. There is a per-array 'next expected sequential IO' sector | |
492 | * number - if this matches on the next IO then we use the last disk. | |
493 | * There is also a per-disk 'last know head position' sector that is | |
494 | * maintained from IRQ contexts, both the normal and the resync IO | |
495 | * completion handlers update this position correctly. If there is no | |
496 | * perfect sequential match then we pick the disk whose head is closest. | |
497 | * | |
498 | * If there are 2 mirrors in the same 2 devices, performance degrades | |
499 | * because position is mirror, not device based. | |
500 | * | |
501 | * The rdev for the device selected will have nr_pending incremented. | |
502 | */ | |
503 | ||
504 | /* | |
505 | * FIXME: possibly should rethink readbalancing and do it differently | |
506 | * depending on near_copies / far_copies geometry. | |
507 | */ | |
508 | static int read_balance(conf_t *conf, r10bio_t *r10_bio) | |
509 | { | |
af3a2cd6 | 510 | const sector_t this_sector = r10_bio->sector; |
56d99121 | 511 | int disk, slot; |
1da177e4 | 512 | const int sectors = r10_bio->sectors; |
56d99121 | 513 | sector_t new_distance, best_dist; |
d6065f7b | 514 | mdk_rdev_t *rdev; |
56d99121 N |
515 | int do_balance; |
516 | int best_slot; | |
1da177e4 LT |
517 | |
518 | raid10_find_phys(conf, r10_bio); | |
519 | rcu_read_lock(); | |
56d99121 N |
520 | retry: |
521 | best_slot = -1; | |
522 | best_dist = MaxSector; | |
523 | do_balance = 1; | |
1da177e4 LT |
524 | /* |
525 | * Check if we can balance. We can balance on the whole | |
6cce3b23 N |
526 | * device if no resync is going on (recovery is ok), or below |
527 | * the resync window. We take the first readable disk when | |
528 | * above the resync window. | |
1da177e4 LT |
529 | */ |
530 | if (conf->mddev->recovery_cp < MaxSector | |
56d99121 N |
531 | && (this_sector + sectors >= conf->next_resync)) |
532 | do_balance = 0; | |
1da177e4 | 533 | |
56d99121 N |
534 | for (slot = 0; slot < conf->copies ; slot++) { |
535 | if (r10_bio->devs[slot].bio == IO_BLOCKED) | |
536 | continue; | |
1da177e4 | 537 | disk = r10_bio->devs[slot].devnum; |
56d99121 N |
538 | rdev = rcu_dereference(conf->mirrors[disk].rdev); |
539 | if (rdev == NULL) | |
1da177e4 | 540 | continue; |
56d99121 N |
541 | if (!test_bit(In_sync, &rdev->flags)) |
542 | continue; | |
543 | ||
544 | if (!do_balance) | |
545 | break; | |
1da177e4 | 546 | |
22dfdf52 N |
547 | /* This optimisation is debatable, and completely destroys |
548 | * sequential read speed for 'far copies' arrays. So only | |
549 | * keep it for 'near' arrays, and review those later. | |
550 | */ | |
56d99121 | 551 | if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) |
1da177e4 | 552 | break; |
8ed3a195 KS |
553 | |
554 | /* for far > 1 always use the lowest address */ | |
555 | if (conf->far_copies > 1) | |
56d99121 | 556 | new_distance = r10_bio->devs[slot].addr; |
8ed3a195 | 557 | else |
56d99121 N |
558 | new_distance = abs(r10_bio->devs[slot].addr - |
559 | conf->mirrors[disk].head_position); | |
560 | if (new_distance < best_dist) { | |
561 | best_dist = new_distance; | |
562 | best_slot = slot; | |
1da177e4 LT |
563 | } |
564 | } | |
56d99121 N |
565 | if (slot == conf->copies) |
566 | slot = best_slot; | |
1da177e4 | 567 | |
56d99121 N |
568 | if (slot >= 0) { |
569 | disk = r10_bio->devs[slot].devnum; | |
570 | rdev = rcu_dereference(conf->mirrors[disk].rdev); | |
571 | if (!rdev) | |
572 | goto retry; | |
573 | atomic_inc(&rdev->nr_pending); | |
574 | if (test_bit(Faulty, &rdev->flags)) { | |
575 | /* Cannot risk returning a device that failed | |
576 | * before we inc'ed nr_pending | |
577 | */ | |
578 | rdev_dec_pending(rdev, conf->mddev); | |
579 | goto retry; | |
580 | } | |
581 | r10_bio->read_slot = slot; | |
582 | } else | |
29fc7e3e | 583 | disk = -1; |
1da177e4 LT |
584 | rcu_read_unlock(); |
585 | ||
586 | return disk; | |
587 | } | |
588 | ||
0d129228 N |
589 | static int raid10_congested(void *data, int bits) |
590 | { | |
591 | mddev_t *mddev = data; | |
070ec55d | 592 | conf_t *conf = mddev->private; |
0d129228 N |
593 | int i, ret = 0; |
594 | ||
3fa841d7 N |
595 | if (mddev_congested(mddev, bits)) |
596 | return 1; | |
0d129228 | 597 | rcu_read_lock(); |
84707f38 | 598 | for (i = 0; i < conf->raid_disks && ret == 0; i++) { |
0d129228 N |
599 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); |
600 | if (rdev && !test_bit(Faulty, &rdev->flags)) { | |
165125e1 | 601 | struct request_queue *q = bdev_get_queue(rdev->bdev); |
0d129228 N |
602 | |
603 | ret |= bdi_congested(&q->backing_dev_info, bits); | |
604 | } | |
605 | } | |
606 | rcu_read_unlock(); | |
607 | return ret; | |
608 | } | |
609 | ||
7eaceacc | 610 | static void flush_pending_writes(conf_t *conf) |
a35e63ef N |
611 | { |
612 | /* Any writes that have been queued but are awaiting | |
613 | * bitmap updates get flushed here. | |
a35e63ef | 614 | */ |
a35e63ef N |
615 | spin_lock_irq(&conf->device_lock); |
616 | ||
617 | if (conf->pending_bio_list.head) { | |
618 | struct bio *bio; | |
619 | bio = bio_list_get(&conf->pending_bio_list); | |
a35e63ef N |
620 | spin_unlock_irq(&conf->device_lock); |
621 | /* flush any pending bitmap writes to disk | |
622 | * before proceeding w/ I/O */ | |
623 | bitmap_unplug(conf->mddev->bitmap); | |
624 | ||
625 | while (bio) { /* submit pending writes */ | |
626 | struct bio *next = bio->bi_next; | |
627 | bio->bi_next = NULL; | |
628 | generic_make_request(bio); | |
629 | bio = next; | |
630 | } | |
a35e63ef N |
631 | } else |
632 | spin_unlock_irq(&conf->device_lock); | |
a35e63ef | 633 | } |
7eaceacc | 634 | |
0a27ec96 N |
635 | /* Barriers.... |
636 | * Sometimes we need to suspend IO while we do something else, | |
637 | * either some resync/recovery, or reconfigure the array. | |
638 | * To do this we raise a 'barrier'. | |
639 | * The 'barrier' is a counter that can be raised multiple times | |
640 | * to count how many activities are happening which preclude | |
641 | * normal IO. | |
642 | * We can only raise the barrier if there is no pending IO. | |
643 | * i.e. if nr_pending == 0. | |
644 | * We choose only to raise the barrier if no-one is waiting for the | |
645 | * barrier to go down. This means that as soon as an IO request | |
646 | * is ready, no other operations which require a barrier will start | |
647 | * until the IO request has had a chance. | |
648 | * | |
649 | * So: regular IO calls 'wait_barrier'. When that returns there | |
650 | * is no backgroup IO happening, It must arrange to call | |
651 | * allow_barrier when it has finished its IO. | |
652 | * backgroup IO calls must call raise_barrier. Once that returns | |
653 | * there is no normal IO happeing. It must arrange to call | |
654 | * lower_barrier when the particular background IO completes. | |
1da177e4 | 655 | */ |
1da177e4 | 656 | |
6cce3b23 | 657 | static void raise_barrier(conf_t *conf, int force) |
1da177e4 | 658 | { |
6cce3b23 | 659 | BUG_ON(force && !conf->barrier); |
1da177e4 | 660 | spin_lock_irq(&conf->resync_lock); |
0a27ec96 | 661 | |
6cce3b23 N |
662 | /* Wait until no block IO is waiting (unless 'force') */ |
663 | wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting, | |
c3b328ac | 664 | conf->resync_lock, ); |
0a27ec96 N |
665 | |
666 | /* block any new IO from starting */ | |
667 | conf->barrier++; | |
668 | ||
c3b328ac | 669 | /* Now wait for all pending IO to complete */ |
0a27ec96 N |
670 | wait_event_lock_irq(conf->wait_barrier, |
671 | !conf->nr_pending && conf->barrier < RESYNC_DEPTH, | |
c3b328ac | 672 | conf->resync_lock, ); |
0a27ec96 N |
673 | |
674 | spin_unlock_irq(&conf->resync_lock); | |
675 | } | |
676 | ||
677 | static void lower_barrier(conf_t *conf) | |
678 | { | |
679 | unsigned long flags; | |
680 | spin_lock_irqsave(&conf->resync_lock, flags); | |
681 | conf->barrier--; | |
682 | spin_unlock_irqrestore(&conf->resync_lock, flags); | |
683 | wake_up(&conf->wait_barrier); | |
684 | } | |
685 | ||
686 | static void wait_barrier(conf_t *conf) | |
687 | { | |
688 | spin_lock_irq(&conf->resync_lock); | |
689 | if (conf->barrier) { | |
690 | conf->nr_waiting++; | |
691 | wait_event_lock_irq(conf->wait_barrier, !conf->barrier, | |
692 | conf->resync_lock, | |
c3b328ac | 693 | ); |
0a27ec96 | 694 | conf->nr_waiting--; |
1da177e4 | 695 | } |
0a27ec96 | 696 | conf->nr_pending++; |
1da177e4 LT |
697 | spin_unlock_irq(&conf->resync_lock); |
698 | } | |
699 | ||
0a27ec96 N |
700 | static void allow_barrier(conf_t *conf) |
701 | { | |
702 | unsigned long flags; | |
703 | spin_lock_irqsave(&conf->resync_lock, flags); | |
704 | conf->nr_pending--; | |
705 | spin_unlock_irqrestore(&conf->resync_lock, flags); | |
706 | wake_up(&conf->wait_barrier); | |
707 | } | |
708 | ||
4443ae10 N |
709 | static void freeze_array(conf_t *conf) |
710 | { | |
711 | /* stop syncio and normal IO and wait for everything to | |
f188593e | 712 | * go quiet. |
4443ae10 | 713 | * We increment barrier and nr_waiting, and then |
1c830532 N |
714 | * wait until nr_pending match nr_queued+1 |
715 | * This is called in the context of one normal IO request | |
716 | * that has failed. Thus any sync request that might be pending | |
717 | * will be blocked by nr_pending, and we need to wait for | |
718 | * pending IO requests to complete or be queued for re-try. | |
719 | * Thus the number queued (nr_queued) plus this request (1) | |
720 | * must match the number of pending IOs (nr_pending) before | |
721 | * we continue. | |
4443ae10 N |
722 | */ |
723 | spin_lock_irq(&conf->resync_lock); | |
724 | conf->barrier++; | |
725 | conf->nr_waiting++; | |
726 | wait_event_lock_irq(conf->wait_barrier, | |
1c830532 | 727 | conf->nr_pending == conf->nr_queued+1, |
4443ae10 | 728 | conf->resync_lock, |
c3b328ac N |
729 | flush_pending_writes(conf)); |
730 | ||
4443ae10 N |
731 | spin_unlock_irq(&conf->resync_lock); |
732 | } | |
733 | ||
734 | static void unfreeze_array(conf_t *conf) | |
735 | { | |
736 | /* reverse the effect of the freeze */ | |
737 | spin_lock_irq(&conf->resync_lock); | |
738 | conf->barrier--; | |
739 | conf->nr_waiting--; | |
740 | wake_up(&conf->wait_barrier); | |
741 | spin_unlock_irq(&conf->resync_lock); | |
742 | } | |
743 | ||
21a52c6d | 744 | static int make_request(mddev_t *mddev, struct bio * bio) |
1da177e4 | 745 | { |
070ec55d | 746 | conf_t *conf = mddev->private; |
1da177e4 LT |
747 | mirror_info_t *mirror; |
748 | r10bio_t *r10_bio; | |
749 | struct bio *read_bio; | |
750 | int i; | |
751 | int chunk_sects = conf->chunk_mask + 1; | |
a362357b | 752 | const int rw = bio_data_dir(bio); |
2c7d46ec | 753 | const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); |
e9c7469b | 754 | const unsigned long do_fua = (bio->bi_rw & REQ_FUA); |
6cce3b23 | 755 | unsigned long flags; |
6bfe0b49 | 756 | mdk_rdev_t *blocked_rdev; |
c3b328ac | 757 | int plugged; |
1da177e4 | 758 | |
e9c7469b TH |
759 | if (unlikely(bio->bi_rw & REQ_FLUSH)) { |
760 | md_flush_request(mddev, bio); | |
e5dcdd80 N |
761 | return 0; |
762 | } | |
763 | ||
1da177e4 LT |
764 | /* If this request crosses a chunk boundary, we need to |
765 | * split it. This will only happen for 1 PAGE (or less) requests. | |
766 | */ | |
767 | if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9) | |
768 | > chunk_sects && | |
769 | conf->near_copies < conf->raid_disks)) { | |
770 | struct bio_pair *bp; | |
771 | /* Sanity check -- queue functions should prevent this happening */ | |
772 | if (bio->bi_vcnt != 1 || | |
773 | bio->bi_idx != 0) | |
774 | goto bad_map; | |
775 | /* This is a one page bio that upper layers | |
776 | * refuse to split for us, so we need to split it. | |
777 | */ | |
6feef531 | 778 | bp = bio_split(bio, |
1da177e4 | 779 | chunk_sects - (bio->bi_sector & (chunk_sects - 1)) ); |
51e9ac77 N |
780 | |
781 | /* Each of these 'make_request' calls will call 'wait_barrier'. | |
782 | * If the first succeeds but the second blocks due to the resync | |
783 | * thread raising the barrier, we will deadlock because the | |
784 | * IO to the underlying device will be queued in generic_make_request | |
785 | * and will never complete, so will never reduce nr_pending. | |
786 | * So increment nr_waiting here so no new raise_barriers will | |
787 | * succeed, and so the second wait_barrier cannot block. | |
788 | */ | |
789 | spin_lock_irq(&conf->resync_lock); | |
790 | conf->nr_waiting++; | |
791 | spin_unlock_irq(&conf->resync_lock); | |
792 | ||
21a52c6d | 793 | if (make_request(mddev, &bp->bio1)) |
1da177e4 | 794 | generic_make_request(&bp->bio1); |
21a52c6d | 795 | if (make_request(mddev, &bp->bio2)) |
1da177e4 LT |
796 | generic_make_request(&bp->bio2); |
797 | ||
51e9ac77 N |
798 | spin_lock_irq(&conf->resync_lock); |
799 | conf->nr_waiting--; | |
800 | wake_up(&conf->wait_barrier); | |
801 | spin_unlock_irq(&conf->resync_lock); | |
802 | ||
1da177e4 LT |
803 | bio_pair_release(bp); |
804 | return 0; | |
805 | bad_map: | |
128595ed N |
806 | printk("md/raid10:%s: make_request bug: can't convert block across chunks" |
807 | " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2, | |
1da177e4 LT |
808 | (unsigned long long)bio->bi_sector, bio->bi_size >> 10); |
809 | ||
6712ecf8 | 810 | bio_io_error(bio); |
1da177e4 LT |
811 | return 0; |
812 | } | |
813 | ||
3d310eb7 | 814 | md_write_start(mddev, bio); |
06d91a5f | 815 | |
1da177e4 LT |
816 | /* |
817 | * Register the new request and wait if the reconstruction | |
818 | * thread has put up a bar for new requests. | |
819 | * Continue immediately if no resync is active currently. | |
820 | */ | |
0a27ec96 | 821 | wait_barrier(conf); |
1da177e4 | 822 | |
1da177e4 LT |
823 | r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO); |
824 | ||
825 | r10_bio->master_bio = bio; | |
826 | r10_bio->sectors = bio->bi_size >> 9; | |
827 | ||
828 | r10_bio->mddev = mddev; | |
829 | r10_bio->sector = bio->bi_sector; | |
6cce3b23 | 830 | r10_bio->state = 0; |
1da177e4 | 831 | |
a362357b | 832 | if (rw == READ) { |
1da177e4 LT |
833 | /* |
834 | * read balancing logic: | |
835 | */ | |
836 | int disk = read_balance(conf, r10_bio); | |
837 | int slot = r10_bio->read_slot; | |
838 | if (disk < 0) { | |
839 | raid_end_bio_io(r10_bio); | |
840 | return 0; | |
841 | } | |
842 | mirror = conf->mirrors + disk; | |
843 | ||
a167f663 | 844 | read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); |
1da177e4 LT |
845 | |
846 | r10_bio->devs[slot].bio = read_bio; | |
847 | ||
848 | read_bio->bi_sector = r10_bio->devs[slot].addr + | |
849 | mirror->rdev->data_offset; | |
850 | read_bio->bi_bdev = mirror->rdev->bdev; | |
851 | read_bio->bi_end_io = raid10_end_read_request; | |
7b6d91da | 852 | read_bio->bi_rw = READ | do_sync; |
1da177e4 LT |
853 | read_bio->bi_private = r10_bio; |
854 | ||
855 | generic_make_request(read_bio); | |
856 | return 0; | |
857 | } | |
858 | ||
859 | /* | |
860 | * WRITE: | |
861 | */ | |
6bfe0b49 | 862 | /* first select target devices under rcu_lock and |
1da177e4 LT |
863 | * inc refcount on their rdev. Record them by setting |
864 | * bios[x] to bio | |
865 | */ | |
c3b328ac N |
866 | plugged = mddev_check_plugged(mddev); |
867 | ||
1da177e4 | 868 | raid10_find_phys(conf, r10_bio); |
6bfe0b49 | 869 | retry_write: |
cb6969e8 | 870 | blocked_rdev = NULL; |
1da177e4 LT |
871 | rcu_read_lock(); |
872 | for (i = 0; i < conf->copies; i++) { | |
873 | int d = r10_bio->devs[i].devnum; | |
d6065f7b | 874 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev); |
6bfe0b49 DW |
875 | if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { |
876 | atomic_inc(&rdev->nr_pending); | |
877 | blocked_rdev = rdev; | |
878 | break; | |
879 | } | |
880 | if (rdev && !test_bit(Faulty, &rdev->flags)) { | |
d6065f7b | 881 | atomic_inc(&rdev->nr_pending); |
1da177e4 | 882 | r10_bio->devs[i].bio = bio; |
6cce3b23 | 883 | } else { |
1da177e4 | 884 | r10_bio->devs[i].bio = NULL; |
6cce3b23 N |
885 | set_bit(R10BIO_Degraded, &r10_bio->state); |
886 | } | |
1da177e4 LT |
887 | } |
888 | rcu_read_unlock(); | |
889 | ||
6bfe0b49 DW |
890 | if (unlikely(blocked_rdev)) { |
891 | /* Have to wait for this device to get unblocked, then retry */ | |
892 | int j; | |
893 | int d; | |
894 | ||
895 | for (j = 0; j < i; j++) | |
896 | if (r10_bio->devs[j].bio) { | |
897 | d = r10_bio->devs[j].devnum; | |
898 | rdev_dec_pending(conf->mirrors[d].rdev, mddev); | |
899 | } | |
900 | allow_barrier(conf); | |
901 | md_wait_for_blocked_rdev(blocked_rdev, mddev); | |
902 | wait_barrier(conf); | |
903 | goto retry_write; | |
904 | } | |
905 | ||
4e78064f N |
906 | atomic_set(&r10_bio->remaining, 1); |
907 | bitmap_startwrite(mddev->bitmap, bio->bi_sector, r10_bio->sectors, 0); | |
06d91a5f | 908 | |
1da177e4 LT |
909 | for (i = 0; i < conf->copies; i++) { |
910 | struct bio *mbio; | |
911 | int d = r10_bio->devs[i].devnum; | |
912 | if (!r10_bio->devs[i].bio) | |
913 | continue; | |
914 | ||
a167f663 | 915 | mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); |
1da177e4 LT |
916 | r10_bio->devs[i].bio = mbio; |
917 | ||
918 | mbio->bi_sector = r10_bio->devs[i].addr+ | |
919 | conf->mirrors[d].rdev->data_offset; | |
920 | mbio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
921 | mbio->bi_end_io = raid10_end_write_request; | |
e9c7469b | 922 | mbio->bi_rw = WRITE | do_sync | do_fua; |
1da177e4 LT |
923 | mbio->bi_private = r10_bio; |
924 | ||
925 | atomic_inc(&r10_bio->remaining); | |
4e78064f N |
926 | spin_lock_irqsave(&conf->device_lock, flags); |
927 | bio_list_add(&conf->pending_bio_list, mbio); | |
4e78064f | 928 | spin_unlock_irqrestore(&conf->device_lock, flags); |
1da177e4 LT |
929 | } |
930 | ||
4e78064f N |
931 | if (atomic_dec_and_test(&r10_bio->remaining)) { |
932 | /* This matches the end of raid10_end_write_request() */ | |
933 | bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector, | |
934 | r10_bio->sectors, | |
935 | !test_bit(R10BIO_Degraded, &r10_bio->state), | |
936 | 0); | |
f6f953aa AR |
937 | md_write_end(mddev); |
938 | raid_end_bio_io(r10_bio); | |
f6f953aa AR |
939 | } |
940 | ||
a35e63ef N |
941 | /* In case raid10d snuck in to freeze_array */ |
942 | wake_up(&conf->wait_barrier); | |
943 | ||
c3b328ac | 944 | if (do_sync || !mddev->bitmap || !plugged) |
e3881a68 | 945 | md_wakeup_thread(mddev->thread); |
1da177e4 LT |
946 | return 0; |
947 | } | |
948 | ||
949 | static void status(struct seq_file *seq, mddev_t *mddev) | |
950 | { | |
070ec55d | 951 | conf_t *conf = mddev->private; |
1da177e4 LT |
952 | int i; |
953 | ||
954 | if (conf->near_copies < conf->raid_disks) | |
9d8f0363 | 955 | seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2); |
1da177e4 LT |
956 | if (conf->near_copies > 1) |
957 | seq_printf(seq, " %d near-copies", conf->near_copies); | |
c93983bf N |
958 | if (conf->far_copies > 1) { |
959 | if (conf->far_offset) | |
960 | seq_printf(seq, " %d offset-copies", conf->far_copies); | |
961 | else | |
962 | seq_printf(seq, " %d far-copies", conf->far_copies); | |
963 | } | |
1da177e4 | 964 | seq_printf(seq, " [%d/%d] [", conf->raid_disks, |
76186dd8 | 965 | conf->raid_disks - mddev->degraded); |
1da177e4 LT |
966 | for (i = 0; i < conf->raid_disks; i++) |
967 | seq_printf(seq, "%s", | |
968 | conf->mirrors[i].rdev && | |
b2d444d7 | 969 | test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
970 | seq_printf(seq, "]"); |
971 | } | |
972 | ||
700c7213 N |
973 | /* check if there are enough drives for |
974 | * every block to appear on atleast one. | |
975 | * Don't consider the device numbered 'ignore' | |
976 | * as we might be about to remove it. | |
977 | */ | |
978 | static int enough(conf_t *conf, int ignore) | |
979 | { | |
980 | int first = 0; | |
981 | ||
982 | do { | |
983 | int n = conf->copies; | |
984 | int cnt = 0; | |
985 | while (n--) { | |
986 | if (conf->mirrors[first].rdev && | |
987 | first != ignore) | |
988 | cnt++; | |
989 | first = (first+1) % conf->raid_disks; | |
990 | } | |
991 | if (cnt == 0) | |
992 | return 0; | |
993 | } while (first != 0); | |
994 | return 1; | |
995 | } | |
996 | ||
1da177e4 LT |
997 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) |
998 | { | |
999 | char b[BDEVNAME_SIZE]; | |
070ec55d | 1000 | conf_t *conf = mddev->private; |
1da177e4 LT |
1001 | |
1002 | /* | |
1003 | * If it is not operational, then we have already marked it as dead | |
1004 | * else if it is the last working disks, ignore the error, let the | |
1005 | * next level up know. | |
1006 | * else mark the drive as failed | |
1007 | */ | |
b2d444d7 | 1008 | if (test_bit(In_sync, &rdev->flags) |
700c7213 | 1009 | && !enough(conf, rdev->raid_disk)) |
1da177e4 LT |
1010 | /* |
1011 | * Don't fail the drive, just return an IO error. | |
1da177e4 LT |
1012 | */ |
1013 | return; | |
c04be0aa N |
1014 | if (test_and_clear_bit(In_sync, &rdev->flags)) { |
1015 | unsigned long flags; | |
1016 | spin_lock_irqsave(&conf->device_lock, flags); | |
1da177e4 | 1017 | mddev->degraded++; |
c04be0aa | 1018 | spin_unlock_irqrestore(&conf->device_lock, flags); |
1da177e4 LT |
1019 | /* |
1020 | * if recovery is running, make sure it aborts. | |
1021 | */ | |
dfc70645 | 1022 | set_bit(MD_RECOVERY_INTR, &mddev->recovery); |
1da177e4 | 1023 | } |
de393cde | 1024 | set_bit(Blocked, &rdev->flags); |
b2d444d7 | 1025 | set_bit(Faulty, &rdev->flags); |
850b2b42 | 1026 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
067032bc JP |
1027 | printk(KERN_ALERT |
1028 | "md/raid10:%s: Disk failure on %s, disabling device.\n" | |
1029 | "md/raid10:%s: Operation continuing on %d devices.\n", | |
128595ed N |
1030 | mdname(mddev), bdevname(rdev->bdev, b), |
1031 | mdname(mddev), conf->raid_disks - mddev->degraded); | |
1da177e4 LT |
1032 | } |
1033 | ||
1034 | static void print_conf(conf_t *conf) | |
1035 | { | |
1036 | int i; | |
1037 | mirror_info_t *tmp; | |
1038 | ||
128595ed | 1039 | printk(KERN_DEBUG "RAID10 conf printout:\n"); |
1da177e4 | 1040 | if (!conf) { |
128595ed | 1041 | printk(KERN_DEBUG "(!conf)\n"); |
1da177e4 LT |
1042 | return; |
1043 | } | |
128595ed | 1044 | printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded, |
1da177e4 LT |
1045 | conf->raid_disks); |
1046 | ||
1047 | for (i = 0; i < conf->raid_disks; i++) { | |
1048 | char b[BDEVNAME_SIZE]; | |
1049 | tmp = conf->mirrors + i; | |
1050 | if (tmp->rdev) | |
128595ed | 1051 | printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n", |
b2d444d7 N |
1052 | i, !test_bit(In_sync, &tmp->rdev->flags), |
1053 | !test_bit(Faulty, &tmp->rdev->flags), | |
1da177e4 LT |
1054 | bdevname(tmp->rdev->bdev,b)); |
1055 | } | |
1056 | } | |
1057 | ||
1058 | static void close_sync(conf_t *conf) | |
1059 | { | |
0a27ec96 N |
1060 | wait_barrier(conf); |
1061 | allow_barrier(conf); | |
1da177e4 LT |
1062 | |
1063 | mempool_destroy(conf->r10buf_pool); | |
1064 | conf->r10buf_pool = NULL; | |
1065 | } | |
1066 | ||
1067 | static int raid10_spare_active(mddev_t *mddev) | |
1068 | { | |
1069 | int i; | |
1070 | conf_t *conf = mddev->private; | |
1071 | mirror_info_t *tmp; | |
6b965620 N |
1072 | int count = 0; |
1073 | unsigned long flags; | |
1da177e4 LT |
1074 | |
1075 | /* | |
1076 | * Find all non-in_sync disks within the RAID10 configuration | |
1077 | * and mark them in_sync | |
1078 | */ | |
1079 | for (i = 0; i < conf->raid_disks; i++) { | |
1080 | tmp = conf->mirrors + i; | |
1081 | if (tmp->rdev | |
b2d444d7 | 1082 | && !test_bit(Faulty, &tmp->rdev->flags) |
c04be0aa | 1083 | && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { |
6b965620 | 1084 | count++; |
e6ffbcb6 | 1085 | sysfs_notify_dirent(tmp->rdev->sysfs_state); |
1da177e4 LT |
1086 | } |
1087 | } | |
6b965620 N |
1088 | spin_lock_irqsave(&conf->device_lock, flags); |
1089 | mddev->degraded -= count; | |
1090 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1da177e4 LT |
1091 | |
1092 | print_conf(conf); | |
6b965620 | 1093 | return count; |
1da177e4 LT |
1094 | } |
1095 | ||
1096 | ||
1097 | static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
1098 | { | |
1099 | conf_t *conf = mddev->private; | |
199050ea | 1100 | int err = -EEXIST; |
1da177e4 | 1101 | int mirror; |
6c2fce2e | 1102 | int first = 0; |
84707f38 | 1103 | int last = conf->raid_disks - 1; |
1da177e4 | 1104 | |
34b343cf N |
1105 | if (rdev->badblocks.count) |
1106 | return -EINVAL; | |
1107 | ||
1da177e4 LT |
1108 | if (mddev->recovery_cp < MaxSector) |
1109 | /* only hot-add to in-sync arrays, as recovery is | |
1110 | * very different from resync | |
1111 | */ | |
199050ea | 1112 | return -EBUSY; |
700c7213 | 1113 | if (!enough(conf, -1)) |
199050ea | 1114 | return -EINVAL; |
1da177e4 | 1115 | |
a53a6c85 | 1116 | if (rdev->raid_disk >= 0) |
6c2fce2e | 1117 | first = last = rdev->raid_disk; |
1da177e4 | 1118 | |
2c4193df | 1119 | if (rdev->saved_raid_disk >= first && |
6cce3b23 N |
1120 | conf->mirrors[rdev->saved_raid_disk].rdev == NULL) |
1121 | mirror = rdev->saved_raid_disk; | |
1122 | else | |
6c2fce2e | 1123 | mirror = first; |
2bb77736 N |
1124 | for ( ; mirror <= last ; mirror++) { |
1125 | mirror_info_t *p = &conf->mirrors[mirror]; | |
1126 | if (p->recovery_disabled == mddev->recovery_disabled) | |
1127 | continue; | |
1128 | if (!p->rdev) | |
1129 | continue; | |
1da177e4 | 1130 | |
2bb77736 N |
1131 | disk_stack_limits(mddev->gendisk, rdev->bdev, |
1132 | rdev->data_offset << 9); | |
1133 | /* as we don't honour merge_bvec_fn, we must | |
1134 | * never risk violating it, so limit | |
1135 | * ->max_segments to one lying with a single | |
1136 | * page, as a one page request is never in | |
1137 | * violation. | |
1138 | */ | |
1139 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn) { | |
1140 | blk_queue_max_segments(mddev->queue, 1); | |
1141 | blk_queue_segment_boundary(mddev->queue, | |
1142 | PAGE_CACHE_SIZE - 1); | |
1da177e4 LT |
1143 | } |
1144 | ||
2bb77736 N |
1145 | p->head_position = 0; |
1146 | rdev->raid_disk = mirror; | |
1147 | err = 0; | |
1148 | if (rdev->saved_raid_disk != mirror) | |
1149 | conf->fullsync = 1; | |
1150 | rcu_assign_pointer(p->rdev, rdev); | |
1151 | break; | |
1152 | } | |
1153 | ||
ac5e7113 | 1154 | md_integrity_add_rdev(rdev, mddev); |
1da177e4 | 1155 | print_conf(conf); |
199050ea | 1156 | return err; |
1da177e4 LT |
1157 | } |
1158 | ||
1159 | static int raid10_remove_disk(mddev_t *mddev, int number) | |
1160 | { | |
1161 | conf_t *conf = mddev->private; | |
1162 | int err = 0; | |
1163 | mdk_rdev_t *rdev; | |
1164 | mirror_info_t *p = conf->mirrors+ number; | |
1165 | ||
1166 | print_conf(conf); | |
1167 | rdev = p->rdev; | |
1168 | if (rdev) { | |
b2d444d7 | 1169 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 LT |
1170 | atomic_read(&rdev->nr_pending)) { |
1171 | err = -EBUSY; | |
1172 | goto abort; | |
1173 | } | |
dfc70645 N |
1174 | /* Only remove faulty devices in recovery |
1175 | * is not possible. | |
1176 | */ | |
1177 | if (!test_bit(Faulty, &rdev->flags) && | |
2bb77736 | 1178 | mddev->recovery_disabled != p->recovery_disabled && |
700c7213 | 1179 | enough(conf, -1)) { |
dfc70645 N |
1180 | err = -EBUSY; |
1181 | goto abort; | |
1182 | } | |
1da177e4 | 1183 | p->rdev = NULL; |
fbd568a3 | 1184 | synchronize_rcu(); |
1da177e4 LT |
1185 | if (atomic_read(&rdev->nr_pending)) { |
1186 | /* lost the race, try later */ | |
1187 | err = -EBUSY; | |
1188 | p->rdev = rdev; | |
ac5e7113 | 1189 | goto abort; |
1da177e4 | 1190 | } |
a91a2785 | 1191 | err = md_integrity_register(mddev); |
1da177e4 LT |
1192 | } |
1193 | abort: | |
1194 | ||
1195 | print_conf(conf); | |
1196 | return err; | |
1197 | } | |
1198 | ||
1199 | ||
6712ecf8 | 1200 | static void end_sync_read(struct bio *bio, int error) |
1da177e4 | 1201 | { |
7b92813c | 1202 | r10bio_t *r10_bio = bio->bi_private; |
070ec55d | 1203 | conf_t *conf = r10_bio->mddev->private; |
778ca018 | 1204 | int d; |
1da177e4 | 1205 | |
778ca018 | 1206 | d = find_bio_disk(conf, r10_bio, bio); |
0eb3ff12 N |
1207 | |
1208 | if (test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
1209 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
4dbcdc75 N |
1210 | else { |
1211 | atomic_add(r10_bio->sectors, | |
1212 | &conf->mirrors[d].rdev->corrected_errors); | |
1213 | if (!test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery)) | |
1214 | md_error(r10_bio->mddev, | |
1215 | conf->mirrors[d].rdev); | |
1216 | } | |
1da177e4 LT |
1217 | |
1218 | /* for reconstruct, we always reschedule after a read. | |
1219 | * for resync, only after all reads | |
1220 | */ | |
73d5c38a | 1221 | rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev); |
1da177e4 LT |
1222 | if (test_bit(R10BIO_IsRecover, &r10_bio->state) || |
1223 | atomic_dec_and_test(&r10_bio->remaining)) { | |
1224 | /* we have read all the blocks, | |
1225 | * do the comparison in process context in raid10d | |
1226 | */ | |
1227 | reschedule_retry(r10_bio); | |
1228 | } | |
1da177e4 LT |
1229 | } |
1230 | ||
6712ecf8 | 1231 | static void end_sync_write(struct bio *bio, int error) |
1da177e4 LT |
1232 | { |
1233 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
7b92813c | 1234 | r10bio_t *r10_bio = bio->bi_private; |
1da177e4 | 1235 | mddev_t *mddev = r10_bio->mddev; |
070ec55d | 1236 | conf_t *conf = mddev->private; |
778ca018 | 1237 | int d; |
1da177e4 | 1238 | |
778ca018 | 1239 | d = find_bio_disk(conf, r10_bio, bio); |
1da177e4 LT |
1240 | |
1241 | if (!uptodate) | |
1242 | md_error(mddev, conf->mirrors[d].rdev); | |
dfc70645 | 1243 | |
73d5c38a | 1244 | rdev_dec_pending(conf->mirrors[d].rdev, mddev); |
1da177e4 LT |
1245 | while (atomic_dec_and_test(&r10_bio->remaining)) { |
1246 | if (r10_bio->master_bio == NULL) { | |
1247 | /* the primary of several recovery bios */ | |
73d5c38a | 1248 | sector_t s = r10_bio->sectors; |
1da177e4 | 1249 | put_buf(r10_bio); |
73d5c38a | 1250 | md_done_sync(mddev, s, 1); |
1da177e4 LT |
1251 | break; |
1252 | } else { | |
1253 | r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio; | |
1254 | put_buf(r10_bio); | |
1255 | r10_bio = r10_bio2; | |
1256 | } | |
1257 | } | |
1da177e4 LT |
1258 | } |
1259 | ||
1260 | /* | |
1261 | * Note: sync and recover and handled very differently for raid10 | |
1262 | * This code is for resync. | |
1263 | * For resync, we read through virtual addresses and read all blocks. | |
1264 | * If there is any error, we schedule a write. The lowest numbered | |
1265 | * drive is authoritative. | |
1266 | * However requests come for physical address, so we need to map. | |
1267 | * For every physical address there are raid_disks/copies virtual addresses, | |
1268 | * which is always are least one, but is not necessarly an integer. | |
1269 | * This means that a physical address can span multiple chunks, so we may | |
1270 | * have to submit multiple io requests for a single sync request. | |
1271 | */ | |
1272 | /* | |
1273 | * We check if all blocks are in-sync and only write to blocks that | |
1274 | * aren't in sync | |
1275 | */ | |
1276 | static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio) | |
1277 | { | |
070ec55d | 1278 | conf_t *conf = mddev->private; |
1da177e4 LT |
1279 | int i, first; |
1280 | struct bio *tbio, *fbio; | |
1281 | ||
1282 | atomic_set(&r10_bio->remaining, 1); | |
1283 | ||
1284 | /* find the first device with a block */ | |
1285 | for (i=0; i<conf->copies; i++) | |
1286 | if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) | |
1287 | break; | |
1288 | ||
1289 | if (i == conf->copies) | |
1290 | goto done; | |
1291 | ||
1292 | first = i; | |
1293 | fbio = r10_bio->devs[i].bio; | |
1294 | ||
1295 | /* now find blocks with errors */ | |
0eb3ff12 N |
1296 | for (i=0 ; i < conf->copies ; i++) { |
1297 | int j, d; | |
1298 | int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9); | |
1da177e4 | 1299 | |
1da177e4 | 1300 | tbio = r10_bio->devs[i].bio; |
0eb3ff12 N |
1301 | |
1302 | if (tbio->bi_end_io != end_sync_read) | |
1303 | continue; | |
1304 | if (i == first) | |
1da177e4 | 1305 | continue; |
0eb3ff12 N |
1306 | if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) { |
1307 | /* We know that the bi_io_vec layout is the same for | |
1308 | * both 'first' and 'i', so we just compare them. | |
1309 | * All vec entries are PAGE_SIZE; | |
1310 | */ | |
1311 | for (j = 0; j < vcnt; j++) | |
1312 | if (memcmp(page_address(fbio->bi_io_vec[j].bv_page), | |
1313 | page_address(tbio->bi_io_vec[j].bv_page), | |
1314 | PAGE_SIZE)) | |
1315 | break; | |
1316 | if (j == vcnt) | |
1317 | continue; | |
1318 | mddev->resync_mismatches += r10_bio->sectors; | |
1319 | } | |
18f08819 N |
1320 | if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) |
1321 | /* Don't fix anything. */ | |
1322 | continue; | |
1da177e4 LT |
1323 | /* Ok, we need to write this bio |
1324 | * First we need to fixup bv_offset, bv_len and | |
1325 | * bi_vecs, as the read request might have corrupted these | |
1326 | */ | |
1327 | tbio->bi_vcnt = vcnt; | |
1328 | tbio->bi_size = r10_bio->sectors << 9; | |
1329 | tbio->bi_idx = 0; | |
1330 | tbio->bi_phys_segments = 0; | |
1da177e4 LT |
1331 | tbio->bi_flags &= ~(BIO_POOL_MASK - 1); |
1332 | tbio->bi_flags |= 1 << BIO_UPTODATE; | |
1333 | tbio->bi_next = NULL; | |
1334 | tbio->bi_rw = WRITE; | |
1335 | tbio->bi_private = r10_bio; | |
1336 | tbio->bi_sector = r10_bio->devs[i].addr; | |
1337 | ||
1338 | for (j=0; j < vcnt ; j++) { | |
1339 | tbio->bi_io_vec[j].bv_offset = 0; | |
1340 | tbio->bi_io_vec[j].bv_len = PAGE_SIZE; | |
1341 | ||
1342 | memcpy(page_address(tbio->bi_io_vec[j].bv_page), | |
1343 | page_address(fbio->bi_io_vec[j].bv_page), | |
1344 | PAGE_SIZE); | |
1345 | } | |
1346 | tbio->bi_end_io = end_sync_write; | |
1347 | ||
1348 | d = r10_bio->devs[i].devnum; | |
1349 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1350 | atomic_inc(&r10_bio->remaining); | |
1351 | md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9); | |
1352 | ||
1353 | tbio->bi_sector += conf->mirrors[d].rdev->data_offset; | |
1354 | tbio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1355 | generic_make_request(tbio); | |
1356 | } | |
1357 | ||
1358 | done: | |
1359 | if (atomic_dec_and_test(&r10_bio->remaining)) { | |
1360 | md_done_sync(mddev, r10_bio->sectors, 1); | |
1361 | put_buf(r10_bio); | |
1362 | } | |
1363 | } | |
1364 | ||
1365 | /* | |
1366 | * Now for the recovery code. | |
1367 | * Recovery happens across physical sectors. | |
1368 | * We recover all non-is_sync drives by finding the virtual address of | |
1369 | * each, and then choose a working drive that also has that virt address. | |
1370 | * There is a separate r10_bio for each non-in_sync drive. | |
1371 | * Only the first two slots are in use. The first for reading, | |
1372 | * The second for writing. | |
1373 | * | |
1374 | */ | |
1375 | ||
1376 | static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio) | |
1377 | { | |
070ec55d | 1378 | conf_t *conf = mddev->private; |
c65060ad NK |
1379 | int d; |
1380 | struct bio *wbio; | |
1da177e4 | 1381 | |
c65060ad NK |
1382 | /* |
1383 | * share the pages with the first bio | |
1da177e4 LT |
1384 | * and submit the write request |
1385 | */ | |
1da177e4 | 1386 | wbio = r10_bio->devs[1].bio; |
1da177e4 LT |
1387 | d = r10_bio->devs[1].devnum; |
1388 | ||
1389 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1390 | md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9); | |
0eb3ff12 N |
1391 | if (test_bit(R10BIO_Uptodate, &r10_bio->state)) |
1392 | generic_make_request(wbio); | |
2bb77736 N |
1393 | else { |
1394 | printk(KERN_NOTICE | |
1395 | "md/raid10:%s: recovery aborted due to read error\n", | |
1396 | mdname(mddev)); | |
1397 | conf->mirrors[d].recovery_disabled = mddev->recovery_disabled; | |
1398 | set_bit(MD_RECOVERY_INTR, &mddev->recovery); | |
1399 | bio_endio(wbio, 0); | |
1400 | } | |
1da177e4 LT |
1401 | } |
1402 | ||
1403 | ||
1e50915f RB |
1404 | /* |
1405 | * Used by fix_read_error() to decay the per rdev read_errors. | |
1406 | * We halve the read error count for every hour that has elapsed | |
1407 | * since the last recorded read error. | |
1408 | * | |
1409 | */ | |
1410 | static void check_decay_read_errors(mddev_t *mddev, mdk_rdev_t *rdev) | |
1411 | { | |
1412 | struct timespec cur_time_mon; | |
1413 | unsigned long hours_since_last; | |
1414 | unsigned int read_errors = atomic_read(&rdev->read_errors); | |
1415 | ||
1416 | ktime_get_ts(&cur_time_mon); | |
1417 | ||
1418 | if (rdev->last_read_error.tv_sec == 0 && | |
1419 | rdev->last_read_error.tv_nsec == 0) { | |
1420 | /* first time we've seen a read error */ | |
1421 | rdev->last_read_error = cur_time_mon; | |
1422 | return; | |
1423 | } | |
1424 | ||
1425 | hours_since_last = (cur_time_mon.tv_sec - | |
1426 | rdev->last_read_error.tv_sec) / 3600; | |
1427 | ||
1428 | rdev->last_read_error = cur_time_mon; | |
1429 | ||
1430 | /* | |
1431 | * if hours_since_last is > the number of bits in read_errors | |
1432 | * just set read errors to 0. We do this to avoid | |
1433 | * overflowing the shift of read_errors by hours_since_last. | |
1434 | */ | |
1435 | if (hours_since_last >= 8 * sizeof(read_errors)) | |
1436 | atomic_set(&rdev->read_errors, 0); | |
1437 | else | |
1438 | atomic_set(&rdev->read_errors, read_errors >> hours_since_last); | |
1439 | } | |
1440 | ||
1da177e4 LT |
1441 | /* |
1442 | * This is a kernel thread which: | |
1443 | * | |
1444 | * 1. Retries failed read operations on working mirrors. | |
1445 | * 2. Updates the raid superblock when problems encounter. | |
6814d536 | 1446 | * 3. Performs writes following reads for array synchronising. |
1da177e4 LT |
1447 | */ |
1448 | ||
6814d536 N |
1449 | static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio) |
1450 | { | |
1451 | int sect = 0; /* Offset from r10_bio->sector */ | |
1452 | int sectors = r10_bio->sectors; | |
1453 | mdk_rdev_t*rdev; | |
1e50915f | 1454 | int max_read_errors = atomic_read(&mddev->max_corr_read_errors); |
0544a21d | 1455 | int d = r10_bio->devs[r10_bio->read_slot].devnum; |
1e50915f | 1456 | |
7c4e06ff N |
1457 | /* still own a reference to this rdev, so it cannot |
1458 | * have been cleared recently. | |
1459 | */ | |
1460 | rdev = conf->mirrors[d].rdev; | |
1e50915f | 1461 | |
7c4e06ff N |
1462 | if (test_bit(Faulty, &rdev->flags)) |
1463 | /* drive has already been failed, just ignore any | |
1464 | more fix_read_error() attempts */ | |
1465 | return; | |
1e50915f | 1466 | |
7c4e06ff N |
1467 | check_decay_read_errors(mddev, rdev); |
1468 | atomic_inc(&rdev->read_errors); | |
1469 | if (atomic_read(&rdev->read_errors) > max_read_errors) { | |
1470 | char b[BDEVNAME_SIZE]; | |
1471 | bdevname(rdev->bdev, b); | |
1e50915f | 1472 | |
7c4e06ff N |
1473 | printk(KERN_NOTICE |
1474 | "md/raid10:%s: %s: Raid device exceeded " | |
1475 | "read_error threshold [cur %d:max %d]\n", | |
1476 | mdname(mddev), b, | |
1477 | atomic_read(&rdev->read_errors), max_read_errors); | |
1478 | printk(KERN_NOTICE | |
1479 | "md/raid10:%s: %s: Failing raid device\n", | |
1480 | mdname(mddev), b); | |
1481 | md_error(mddev, conf->mirrors[d].rdev); | |
1482 | return; | |
1e50915f | 1483 | } |
1e50915f | 1484 | |
6814d536 N |
1485 | while(sectors) { |
1486 | int s = sectors; | |
1487 | int sl = r10_bio->read_slot; | |
1488 | int success = 0; | |
1489 | int start; | |
1490 | ||
1491 | if (s > (PAGE_SIZE>>9)) | |
1492 | s = PAGE_SIZE >> 9; | |
1493 | ||
1494 | rcu_read_lock(); | |
1495 | do { | |
0544a21d | 1496 | d = r10_bio->devs[sl].devnum; |
6814d536 N |
1497 | rdev = rcu_dereference(conf->mirrors[d].rdev); |
1498 | if (rdev && | |
1499 | test_bit(In_sync, &rdev->flags)) { | |
1500 | atomic_inc(&rdev->nr_pending); | |
1501 | rcu_read_unlock(); | |
2b193363 | 1502 | success = sync_page_io(rdev, |
6814d536 | 1503 | r10_bio->devs[sl].addr + |
ccebd4c4 | 1504 | sect, |
6814d536 | 1505 | s<<9, |
ccebd4c4 | 1506 | conf->tmppage, READ, false); |
6814d536 N |
1507 | rdev_dec_pending(rdev, mddev); |
1508 | rcu_read_lock(); | |
1509 | if (success) | |
1510 | break; | |
1511 | } | |
1512 | sl++; | |
1513 | if (sl == conf->copies) | |
1514 | sl = 0; | |
1515 | } while (!success && sl != r10_bio->read_slot); | |
1516 | rcu_read_unlock(); | |
1517 | ||
1518 | if (!success) { | |
1519 | /* Cannot read from anywhere -- bye bye array */ | |
1520 | int dn = r10_bio->devs[r10_bio->read_slot].devnum; | |
1521 | md_error(mddev, conf->mirrors[dn].rdev); | |
1522 | break; | |
1523 | } | |
1524 | ||
1525 | start = sl; | |
1526 | /* write it back and re-read */ | |
1527 | rcu_read_lock(); | |
1528 | while (sl != r10_bio->read_slot) { | |
67b8dc4b | 1529 | char b[BDEVNAME_SIZE]; |
0544a21d | 1530 | |
6814d536 N |
1531 | if (sl==0) |
1532 | sl = conf->copies; | |
1533 | sl--; | |
1534 | d = r10_bio->devs[sl].devnum; | |
1535 | rdev = rcu_dereference(conf->mirrors[d].rdev); | |
1294b9c9 N |
1536 | if (!rdev || |
1537 | !test_bit(In_sync, &rdev->flags)) | |
1538 | continue; | |
1539 | ||
1540 | atomic_inc(&rdev->nr_pending); | |
1541 | rcu_read_unlock(); | |
1542 | if (sync_page_io(rdev, | |
1543 | r10_bio->devs[sl].addr + | |
1544 | sect, | |
1545 | s<<9, conf->tmppage, WRITE, false) | |
1546 | == 0) { | |
1547 | /* Well, this device is dead */ | |
1548 | printk(KERN_NOTICE | |
1549 | "md/raid10:%s: read correction " | |
1550 | "write failed" | |
1551 | " (%d sectors at %llu on %s)\n", | |
1552 | mdname(mddev), s, | |
1553 | (unsigned long long)( | |
1554 | sect + rdev->data_offset), | |
1555 | bdevname(rdev->bdev, b)); | |
1556 | printk(KERN_NOTICE "md/raid10:%s: %s: failing " | |
1557 | "drive\n", | |
1558 | mdname(mddev), | |
1559 | bdevname(rdev->bdev, b)); | |
1560 | md_error(mddev, rdev); | |
6814d536 | 1561 | } |
1294b9c9 N |
1562 | rdev_dec_pending(rdev, mddev); |
1563 | rcu_read_lock(); | |
6814d536 N |
1564 | } |
1565 | sl = start; | |
1566 | while (sl != r10_bio->read_slot) { | |
1294b9c9 | 1567 | char b[BDEVNAME_SIZE]; |
0544a21d | 1568 | |
6814d536 N |
1569 | if (sl==0) |
1570 | sl = conf->copies; | |
1571 | sl--; | |
1572 | d = r10_bio->devs[sl].devnum; | |
1573 | rdev = rcu_dereference(conf->mirrors[d].rdev); | |
1294b9c9 N |
1574 | if (!rdev || |
1575 | !test_bit(In_sync, &rdev->flags)) | |
1576 | continue; | |
6814d536 | 1577 | |
1294b9c9 N |
1578 | atomic_inc(&rdev->nr_pending); |
1579 | rcu_read_unlock(); | |
1580 | if (sync_page_io(rdev, | |
1581 | r10_bio->devs[sl].addr + | |
1582 | sect, | |
1583 | s<<9, conf->tmppage, | |
1584 | READ, false) == 0) { | |
1585 | /* Well, this device is dead */ | |
1586 | printk(KERN_NOTICE | |
1587 | "md/raid10:%s: unable to read back " | |
1588 | "corrected sectors" | |
1589 | " (%d sectors at %llu on %s)\n", | |
1590 | mdname(mddev), s, | |
1591 | (unsigned long long)( | |
1592 | sect + rdev->data_offset), | |
1593 | bdevname(rdev->bdev, b)); | |
1594 | printk(KERN_NOTICE "md/raid10:%s: %s: failing " | |
1595 | "drive\n", | |
1596 | mdname(mddev), | |
1597 | bdevname(rdev->bdev, b)); | |
1598 | ||
1599 | md_error(mddev, rdev); | |
1600 | } else { | |
1601 | printk(KERN_INFO | |
1602 | "md/raid10:%s: read error corrected" | |
1603 | " (%d sectors at %llu on %s)\n", | |
1604 | mdname(mddev), s, | |
1605 | (unsigned long long)( | |
1606 | sect + rdev->data_offset), | |
1607 | bdevname(rdev->bdev, b)); | |
1608 | atomic_add(s, &rdev->corrected_errors); | |
6814d536 | 1609 | } |
1294b9c9 N |
1610 | |
1611 | rdev_dec_pending(rdev, mddev); | |
1612 | rcu_read_lock(); | |
6814d536 N |
1613 | } |
1614 | rcu_read_unlock(); | |
1615 | ||
1616 | sectors -= s; | |
1617 | sect += s; | |
1618 | } | |
1619 | } | |
1620 | ||
560f8e55 N |
1621 | static void handle_read_error(mddev_t *mddev, r10bio_t *r10_bio) |
1622 | { | |
1623 | int slot = r10_bio->read_slot; | |
1624 | int mirror = r10_bio->devs[slot].devnum; | |
1625 | struct bio *bio; | |
1626 | conf_t *conf = mddev->private; | |
1627 | mdk_rdev_t *rdev; | |
1628 | char b[BDEVNAME_SIZE]; | |
1629 | unsigned long do_sync; | |
1630 | ||
1631 | /* we got a read error. Maybe the drive is bad. Maybe just | |
1632 | * the block and we can fix it. | |
1633 | * We freeze all other IO, and try reading the block from | |
1634 | * other devices. When we find one, we re-write | |
1635 | * and check it that fixes the read error. | |
1636 | * This is all done synchronously while the array is | |
1637 | * frozen. | |
1638 | */ | |
1639 | if (mddev->ro == 0) { | |
1640 | freeze_array(conf); | |
1641 | fix_read_error(conf, mddev, r10_bio); | |
1642 | unfreeze_array(conf); | |
1643 | } | |
1644 | rdev_dec_pending(conf->mirrors[mirror].rdev, mddev); | |
1645 | ||
1646 | bio = r10_bio->devs[slot].bio; | |
1647 | r10_bio->devs[slot].bio = | |
1648 | mddev->ro ? IO_BLOCKED : NULL; | |
1649 | mirror = read_balance(conf, r10_bio); | |
1650 | if (mirror == -1) { | |
1651 | printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O" | |
1652 | " read error for block %llu\n", | |
1653 | mdname(mddev), | |
1654 | bdevname(bio->bi_bdev, b), | |
1655 | (unsigned long long)r10_bio->sector); | |
1656 | raid_end_bio_io(r10_bio); | |
1657 | bio_put(bio); | |
1658 | return; | |
1659 | } | |
1660 | ||
1661 | do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC); | |
1662 | bio_put(bio); | |
1663 | slot = r10_bio->read_slot; | |
1664 | rdev = conf->mirrors[mirror].rdev; | |
1665 | printk_ratelimited( | |
1666 | KERN_ERR | |
1667 | "md/raid10:%s: %s: redirecting" | |
1668 | "sector %llu to another mirror\n", | |
1669 | mdname(mddev), | |
1670 | bdevname(rdev->bdev, b), | |
1671 | (unsigned long long)r10_bio->sector); | |
1672 | bio = bio_clone_mddev(r10_bio->master_bio, | |
1673 | GFP_NOIO, mddev); | |
1674 | r10_bio->devs[slot].bio = bio; | |
1675 | bio->bi_sector = r10_bio->devs[slot].addr | |
1676 | + rdev->data_offset; | |
1677 | bio->bi_bdev = rdev->bdev; | |
1678 | bio->bi_rw = READ | do_sync; | |
1679 | bio->bi_private = r10_bio; | |
1680 | bio->bi_end_io = raid10_end_read_request; | |
1681 | generic_make_request(bio); | |
1682 | } | |
1683 | ||
1da177e4 LT |
1684 | static void raid10d(mddev_t *mddev) |
1685 | { | |
1686 | r10bio_t *r10_bio; | |
1da177e4 | 1687 | unsigned long flags; |
070ec55d | 1688 | conf_t *conf = mddev->private; |
1da177e4 | 1689 | struct list_head *head = &conf->retry_list; |
e1dfa0a2 | 1690 | struct blk_plug plug; |
1da177e4 LT |
1691 | |
1692 | md_check_recovery(mddev); | |
1da177e4 | 1693 | |
e1dfa0a2 | 1694 | blk_start_plug(&plug); |
1da177e4 | 1695 | for (;;) { |
6cce3b23 | 1696 | |
7eaceacc | 1697 | flush_pending_writes(conf); |
6cce3b23 | 1698 | |
a35e63ef N |
1699 | spin_lock_irqsave(&conf->device_lock, flags); |
1700 | if (list_empty(head)) { | |
1701 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1da177e4 | 1702 | break; |
a35e63ef | 1703 | } |
1da177e4 LT |
1704 | r10_bio = list_entry(head->prev, r10bio_t, retry_list); |
1705 | list_del(head->prev); | |
4443ae10 | 1706 | conf->nr_queued--; |
1da177e4 LT |
1707 | spin_unlock_irqrestore(&conf->device_lock, flags); |
1708 | ||
1709 | mddev = r10_bio->mddev; | |
070ec55d | 1710 | conf = mddev->private; |
7eaceacc | 1711 | if (test_bit(R10BIO_IsSync, &r10_bio->state)) |
1da177e4 | 1712 | sync_request_write(mddev, r10_bio); |
7eaceacc | 1713 | else if (test_bit(R10BIO_IsRecover, &r10_bio->state)) |
1da177e4 | 1714 | recovery_request_write(mddev, r10_bio); |
560f8e55 N |
1715 | else |
1716 | handle_read_error(mddev, r10_bio); | |
1717 | ||
1d9d5241 | 1718 | cond_resched(); |
de393cde N |
1719 | if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) |
1720 | md_check_recovery(mddev); | |
1da177e4 | 1721 | } |
e1dfa0a2 | 1722 | blk_finish_plug(&plug); |
1da177e4 LT |
1723 | } |
1724 | ||
1725 | ||
1726 | static int init_resync(conf_t *conf) | |
1727 | { | |
1728 | int buffs; | |
1729 | ||
1730 | buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; | |
b6385483 | 1731 | BUG_ON(conf->r10buf_pool); |
1da177e4 LT |
1732 | conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf); |
1733 | if (!conf->r10buf_pool) | |
1734 | return -ENOMEM; | |
1735 | conf->next_resync = 0; | |
1736 | return 0; | |
1737 | } | |
1738 | ||
1739 | /* | |
1740 | * perform a "sync" on one "block" | |
1741 | * | |
1742 | * We need to make sure that no normal I/O request - particularly write | |
1743 | * requests - conflict with active sync requests. | |
1744 | * | |
1745 | * This is achieved by tracking pending requests and a 'barrier' concept | |
1746 | * that can be installed to exclude normal IO requests. | |
1747 | * | |
1748 | * Resync and recovery are handled very differently. | |
1749 | * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery. | |
1750 | * | |
1751 | * For resync, we iterate over virtual addresses, read all copies, | |
1752 | * and update if there are differences. If only one copy is live, | |
1753 | * skip it. | |
1754 | * For recovery, we iterate over physical addresses, read a good | |
1755 | * value for each non-in_sync drive, and over-write. | |
1756 | * | |
1757 | * So, for recovery we may have several outstanding complex requests for a | |
1758 | * given address, one for each out-of-sync device. We model this by allocating | |
1759 | * a number of r10_bio structures, one for each out-of-sync device. | |
1760 | * As we setup these structures, we collect all bio's together into a list | |
1761 | * which we then process collectively to add pages, and then process again | |
1762 | * to pass to generic_make_request. | |
1763 | * | |
1764 | * The r10_bio structures are linked using a borrowed master_bio pointer. | |
1765 | * This link is counted in ->remaining. When the r10_bio that points to NULL | |
1766 | * has its remaining count decremented to 0, the whole complex operation | |
1767 | * is complete. | |
1768 | * | |
1769 | */ | |
1770 | ||
ab9d47e9 N |
1771 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, |
1772 | int *skipped, int go_faster) | |
1da177e4 | 1773 | { |
070ec55d | 1774 | conf_t *conf = mddev->private; |
1da177e4 LT |
1775 | r10bio_t *r10_bio; |
1776 | struct bio *biolist = NULL, *bio; | |
1777 | sector_t max_sector, nr_sectors; | |
1da177e4 | 1778 | int i; |
6cce3b23 | 1779 | int max_sync; |
57dab0bd | 1780 | sector_t sync_blocks; |
1da177e4 LT |
1781 | |
1782 | sector_t sectors_skipped = 0; | |
1783 | int chunks_skipped = 0; | |
1784 | ||
1785 | if (!conf->r10buf_pool) | |
1786 | if (init_resync(conf)) | |
57afd89f | 1787 | return 0; |
1da177e4 LT |
1788 | |
1789 | skipped: | |
58c0fed4 | 1790 | max_sector = mddev->dev_sectors; |
1da177e4 LT |
1791 | if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) |
1792 | max_sector = mddev->resync_max_sectors; | |
1793 | if (sector_nr >= max_sector) { | |
6cce3b23 N |
1794 | /* If we aborted, we need to abort the |
1795 | * sync on the 'current' bitmap chucks (there can | |
1796 | * be several when recovering multiple devices). | |
1797 | * as we may have started syncing it but not finished. | |
1798 | * We can find the current address in | |
1799 | * mddev->curr_resync, but for recovery, | |
1800 | * we need to convert that to several | |
1801 | * virtual addresses. | |
1802 | */ | |
1803 | if (mddev->curr_resync < max_sector) { /* aborted */ | |
1804 | if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) | |
1805 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, | |
1806 | &sync_blocks, 1); | |
1807 | else for (i=0; i<conf->raid_disks; i++) { | |
1808 | sector_t sect = | |
1809 | raid10_find_virt(conf, mddev->curr_resync, i); | |
1810 | bitmap_end_sync(mddev->bitmap, sect, | |
1811 | &sync_blocks, 1); | |
1812 | } | |
1813 | } else /* completed sync */ | |
1814 | conf->fullsync = 0; | |
1815 | ||
1816 | bitmap_close_sync(mddev->bitmap); | |
1da177e4 | 1817 | close_sync(conf); |
57afd89f | 1818 | *skipped = 1; |
1da177e4 LT |
1819 | return sectors_skipped; |
1820 | } | |
1821 | if (chunks_skipped >= conf->raid_disks) { | |
1822 | /* if there has been nothing to do on any drive, | |
1823 | * then there is nothing to do at all.. | |
1824 | */ | |
57afd89f N |
1825 | *skipped = 1; |
1826 | return (max_sector - sector_nr) + sectors_skipped; | |
1da177e4 LT |
1827 | } |
1828 | ||
c6207277 N |
1829 | if (max_sector > mddev->resync_max) |
1830 | max_sector = mddev->resync_max; /* Don't do IO beyond here */ | |
1831 | ||
1da177e4 LT |
1832 | /* make sure whole request will fit in a chunk - if chunks |
1833 | * are meaningful | |
1834 | */ | |
1835 | if (conf->near_copies < conf->raid_disks && | |
1836 | max_sector > (sector_nr | conf->chunk_mask)) | |
1837 | max_sector = (sector_nr | conf->chunk_mask) + 1; | |
1838 | /* | |
1839 | * If there is non-resync activity waiting for us then | |
1840 | * put in a delay to throttle resync. | |
1841 | */ | |
0a27ec96 | 1842 | if (!go_faster && conf->nr_waiting) |
1da177e4 | 1843 | msleep_interruptible(1000); |
1da177e4 LT |
1844 | |
1845 | /* Again, very different code for resync and recovery. | |
1846 | * Both must result in an r10bio with a list of bios that | |
1847 | * have bi_end_io, bi_sector, bi_bdev set, | |
1848 | * and bi_private set to the r10bio. | |
1849 | * For recovery, we may actually create several r10bios | |
1850 | * with 2 bios in each, that correspond to the bios in the main one. | |
1851 | * In this case, the subordinate r10bios link back through a | |
1852 | * borrowed master_bio pointer, and the counter in the master | |
1853 | * includes a ref from each subordinate. | |
1854 | */ | |
1855 | /* First, we decide what to do and set ->bi_end_io | |
1856 | * To end_sync_read if we want to read, and | |
1857 | * end_sync_write if we will want to write. | |
1858 | */ | |
1859 | ||
6cce3b23 | 1860 | max_sync = RESYNC_PAGES << (PAGE_SHIFT-9); |
1da177e4 LT |
1861 | if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { |
1862 | /* recovery... the complicated one */ | |
a9f326eb | 1863 | int j, k; |
1da177e4 LT |
1864 | r10_bio = NULL; |
1865 | ||
ab9d47e9 N |
1866 | for (i=0 ; i<conf->raid_disks; i++) { |
1867 | int still_degraded; | |
1868 | r10bio_t *rb2; | |
1869 | sector_t sect; | |
1870 | int must_sync; | |
1da177e4 | 1871 | |
ab9d47e9 N |
1872 | if (conf->mirrors[i].rdev == NULL || |
1873 | test_bit(In_sync, &conf->mirrors[i].rdev->flags)) | |
1874 | continue; | |
1da177e4 | 1875 | |
ab9d47e9 N |
1876 | still_degraded = 0; |
1877 | /* want to reconstruct this device */ | |
1878 | rb2 = r10_bio; | |
1879 | sect = raid10_find_virt(conf, sector_nr, i); | |
1880 | /* Unless we are doing a full sync, we only need | |
1881 | * to recover the block if it is set in the bitmap | |
1882 | */ | |
1883 | must_sync = bitmap_start_sync(mddev->bitmap, sect, | |
1884 | &sync_blocks, 1); | |
1885 | if (sync_blocks < max_sync) | |
1886 | max_sync = sync_blocks; | |
1887 | if (!must_sync && | |
1888 | !conf->fullsync) { | |
1889 | /* yep, skip the sync_blocks here, but don't assume | |
1890 | * that there will never be anything to do here | |
1891 | */ | |
1892 | chunks_skipped = -1; | |
1893 | continue; | |
1894 | } | |
6cce3b23 | 1895 | |
ab9d47e9 N |
1896 | r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO); |
1897 | raise_barrier(conf, rb2 != NULL); | |
1898 | atomic_set(&r10_bio->remaining, 0); | |
18055569 | 1899 | |
ab9d47e9 N |
1900 | r10_bio->master_bio = (struct bio*)rb2; |
1901 | if (rb2) | |
1902 | atomic_inc(&rb2->remaining); | |
1903 | r10_bio->mddev = mddev; | |
1904 | set_bit(R10BIO_IsRecover, &r10_bio->state); | |
1905 | r10_bio->sector = sect; | |
1da177e4 | 1906 | |
ab9d47e9 N |
1907 | raid10_find_phys(conf, r10_bio); |
1908 | ||
1909 | /* Need to check if the array will still be | |
1910 | * degraded | |
1911 | */ | |
1912 | for (j=0; j<conf->raid_disks; j++) | |
1913 | if (conf->mirrors[j].rdev == NULL || | |
1914 | test_bit(Faulty, &conf->mirrors[j].rdev->flags)) { | |
1915 | still_degraded = 1; | |
87fc767b | 1916 | break; |
1da177e4 | 1917 | } |
ab9d47e9 N |
1918 | |
1919 | must_sync = bitmap_start_sync(mddev->bitmap, sect, | |
1920 | &sync_blocks, still_degraded); | |
1921 | ||
1922 | for (j=0; j<conf->copies;j++) { | |
1923 | int d = r10_bio->devs[j].devnum; | |
1924 | if (!conf->mirrors[d].rdev || | |
1925 | !test_bit(In_sync, &conf->mirrors[d].rdev->flags)) | |
1926 | continue; | |
1927 | /* This is where we read from */ | |
1928 | bio = r10_bio->devs[0].bio; | |
1929 | bio->bi_next = biolist; | |
1930 | biolist = bio; | |
1931 | bio->bi_private = r10_bio; | |
1932 | bio->bi_end_io = end_sync_read; | |
1933 | bio->bi_rw = READ; | |
1934 | bio->bi_sector = r10_bio->devs[j].addr + | |
1935 | conf->mirrors[d].rdev->data_offset; | |
1936 | bio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1937 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1938 | atomic_inc(&r10_bio->remaining); | |
1939 | /* and we write to 'i' */ | |
1940 | ||
1941 | for (k=0; k<conf->copies; k++) | |
1942 | if (r10_bio->devs[k].devnum == i) | |
1943 | break; | |
1944 | BUG_ON(k == conf->copies); | |
1945 | bio = r10_bio->devs[1].bio; | |
1946 | bio->bi_next = biolist; | |
1947 | biolist = bio; | |
1948 | bio->bi_private = r10_bio; | |
1949 | bio->bi_end_io = end_sync_write; | |
1950 | bio->bi_rw = WRITE; | |
1951 | bio->bi_sector = r10_bio->devs[k].addr + | |
1952 | conf->mirrors[i].rdev->data_offset; | |
1953 | bio->bi_bdev = conf->mirrors[i].rdev->bdev; | |
1954 | ||
1955 | r10_bio->devs[0].devnum = d; | |
1956 | r10_bio->devs[1].devnum = i; | |
1957 | ||
1958 | break; | |
1959 | } | |
1960 | if (j == conf->copies) { | |
1961 | /* Cannot recover, so abort the recovery */ | |
1962 | put_buf(r10_bio); | |
1963 | if (rb2) | |
1964 | atomic_dec(&rb2->remaining); | |
1965 | r10_bio = rb2; | |
1966 | if (!test_and_set_bit(MD_RECOVERY_INTR, | |
1967 | &mddev->recovery)) | |
1968 | printk(KERN_INFO "md/raid10:%s: insufficient " | |
1969 | "working devices for recovery.\n", | |
1970 | mdname(mddev)); | |
1971 | break; | |
1da177e4 | 1972 | } |
ab9d47e9 | 1973 | } |
1da177e4 LT |
1974 | if (biolist == NULL) { |
1975 | while (r10_bio) { | |
1976 | r10bio_t *rb2 = r10_bio; | |
1977 | r10_bio = (r10bio_t*) rb2->master_bio; | |
1978 | rb2->master_bio = NULL; | |
1979 | put_buf(rb2); | |
1980 | } | |
1981 | goto giveup; | |
1982 | } | |
1983 | } else { | |
1984 | /* resync. Schedule a read for every block at this virt offset */ | |
1985 | int count = 0; | |
6cce3b23 | 1986 | |
78200d45 N |
1987 | bitmap_cond_end_sync(mddev->bitmap, sector_nr); |
1988 | ||
6cce3b23 N |
1989 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, |
1990 | &sync_blocks, mddev->degraded) && | |
ab9d47e9 N |
1991 | !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, |
1992 | &mddev->recovery)) { | |
6cce3b23 N |
1993 | /* We can skip this block */ |
1994 | *skipped = 1; | |
1995 | return sync_blocks + sectors_skipped; | |
1996 | } | |
1997 | if (sync_blocks < max_sync) | |
1998 | max_sync = sync_blocks; | |
1da177e4 LT |
1999 | r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO); |
2000 | ||
1da177e4 LT |
2001 | r10_bio->mddev = mddev; |
2002 | atomic_set(&r10_bio->remaining, 0); | |
6cce3b23 N |
2003 | raise_barrier(conf, 0); |
2004 | conf->next_resync = sector_nr; | |
1da177e4 LT |
2005 | |
2006 | r10_bio->master_bio = NULL; | |
2007 | r10_bio->sector = sector_nr; | |
2008 | set_bit(R10BIO_IsSync, &r10_bio->state); | |
2009 | raid10_find_phys(conf, r10_bio); | |
2010 | r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1; | |
2011 | ||
2012 | for (i=0; i<conf->copies; i++) { | |
2013 | int d = r10_bio->devs[i].devnum; | |
2014 | bio = r10_bio->devs[i].bio; | |
2015 | bio->bi_end_io = NULL; | |
af03b8e4 | 2016 | clear_bit(BIO_UPTODATE, &bio->bi_flags); |
1da177e4 | 2017 | if (conf->mirrors[d].rdev == NULL || |
b2d444d7 | 2018 | test_bit(Faulty, &conf->mirrors[d].rdev->flags)) |
1da177e4 LT |
2019 | continue; |
2020 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
2021 | atomic_inc(&r10_bio->remaining); | |
2022 | bio->bi_next = biolist; | |
2023 | biolist = bio; | |
2024 | bio->bi_private = r10_bio; | |
2025 | bio->bi_end_io = end_sync_read; | |
802ba064 | 2026 | bio->bi_rw = READ; |
1da177e4 LT |
2027 | bio->bi_sector = r10_bio->devs[i].addr + |
2028 | conf->mirrors[d].rdev->data_offset; | |
2029 | bio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
2030 | count++; | |
2031 | } | |
2032 | ||
2033 | if (count < 2) { | |
2034 | for (i=0; i<conf->copies; i++) { | |
2035 | int d = r10_bio->devs[i].devnum; | |
2036 | if (r10_bio->devs[i].bio->bi_end_io) | |
ab9d47e9 N |
2037 | rdev_dec_pending(conf->mirrors[d].rdev, |
2038 | mddev); | |
1da177e4 LT |
2039 | } |
2040 | put_buf(r10_bio); | |
2041 | biolist = NULL; | |
2042 | goto giveup; | |
2043 | } | |
2044 | } | |
2045 | ||
2046 | for (bio = biolist; bio ; bio=bio->bi_next) { | |
2047 | ||
2048 | bio->bi_flags &= ~(BIO_POOL_MASK - 1); | |
2049 | if (bio->bi_end_io) | |
2050 | bio->bi_flags |= 1 << BIO_UPTODATE; | |
2051 | bio->bi_vcnt = 0; | |
2052 | bio->bi_idx = 0; | |
2053 | bio->bi_phys_segments = 0; | |
1da177e4 LT |
2054 | bio->bi_size = 0; |
2055 | } | |
2056 | ||
2057 | nr_sectors = 0; | |
6cce3b23 N |
2058 | if (sector_nr + max_sync < max_sector) |
2059 | max_sector = sector_nr + max_sync; | |
1da177e4 LT |
2060 | do { |
2061 | struct page *page; | |
2062 | int len = PAGE_SIZE; | |
1da177e4 LT |
2063 | if (sector_nr + (len>>9) > max_sector) |
2064 | len = (max_sector - sector_nr) << 9; | |
2065 | if (len == 0) | |
2066 | break; | |
2067 | for (bio= biolist ; bio ; bio=bio->bi_next) { | |
ab9d47e9 | 2068 | struct bio *bio2; |
1da177e4 | 2069 | page = bio->bi_io_vec[bio->bi_vcnt].bv_page; |
ab9d47e9 N |
2070 | if (bio_add_page(bio, page, len, 0)) |
2071 | continue; | |
2072 | ||
2073 | /* stop here */ | |
2074 | bio->bi_io_vec[bio->bi_vcnt].bv_page = page; | |
2075 | for (bio2 = biolist; | |
2076 | bio2 && bio2 != bio; | |
2077 | bio2 = bio2->bi_next) { | |
2078 | /* remove last page from this bio */ | |
2079 | bio2->bi_vcnt--; | |
2080 | bio2->bi_size -= len; | |
2081 | bio2->bi_flags &= ~(1<< BIO_SEG_VALID); | |
1da177e4 | 2082 | } |
ab9d47e9 | 2083 | goto bio_full; |
1da177e4 LT |
2084 | } |
2085 | nr_sectors += len>>9; | |
2086 | sector_nr += len>>9; | |
2087 | } while (biolist->bi_vcnt < RESYNC_PAGES); | |
2088 | bio_full: | |
2089 | r10_bio->sectors = nr_sectors; | |
2090 | ||
2091 | while (biolist) { | |
2092 | bio = biolist; | |
2093 | biolist = biolist->bi_next; | |
2094 | ||
2095 | bio->bi_next = NULL; | |
2096 | r10_bio = bio->bi_private; | |
2097 | r10_bio->sectors = nr_sectors; | |
2098 | ||
2099 | if (bio->bi_end_io == end_sync_read) { | |
2100 | md_sync_acct(bio->bi_bdev, nr_sectors); | |
2101 | generic_make_request(bio); | |
2102 | } | |
2103 | } | |
2104 | ||
57afd89f N |
2105 | if (sectors_skipped) |
2106 | /* pretend they weren't skipped, it makes | |
2107 | * no important difference in this case | |
2108 | */ | |
2109 | md_done_sync(mddev, sectors_skipped, 1); | |
2110 | ||
1da177e4 LT |
2111 | return sectors_skipped + nr_sectors; |
2112 | giveup: | |
2113 | /* There is nowhere to write, so all non-sync | |
2114 | * drives must be failed, so try the next chunk... | |
2115 | */ | |
09b4068a N |
2116 | if (sector_nr + max_sync < max_sector) |
2117 | max_sector = sector_nr + max_sync; | |
2118 | ||
2119 | sectors_skipped += (max_sector - sector_nr); | |
1da177e4 LT |
2120 | chunks_skipped ++; |
2121 | sector_nr = max_sector; | |
1da177e4 | 2122 | goto skipped; |
1da177e4 LT |
2123 | } |
2124 | ||
80c3a6ce DW |
2125 | static sector_t |
2126 | raid10_size(mddev_t *mddev, sector_t sectors, int raid_disks) | |
2127 | { | |
2128 | sector_t size; | |
070ec55d | 2129 | conf_t *conf = mddev->private; |
80c3a6ce DW |
2130 | |
2131 | if (!raid_disks) | |
84707f38 | 2132 | raid_disks = conf->raid_disks; |
80c3a6ce | 2133 | if (!sectors) |
dab8b292 | 2134 | sectors = conf->dev_sectors; |
80c3a6ce DW |
2135 | |
2136 | size = sectors >> conf->chunk_shift; | |
2137 | sector_div(size, conf->far_copies); | |
2138 | size = size * raid_disks; | |
2139 | sector_div(size, conf->near_copies); | |
2140 | ||
2141 | return size << conf->chunk_shift; | |
2142 | } | |
2143 | ||
dab8b292 TM |
2144 | |
2145 | static conf_t *setup_conf(mddev_t *mddev) | |
1da177e4 | 2146 | { |
dab8b292 | 2147 | conf_t *conf = NULL; |
c93983bf | 2148 | int nc, fc, fo; |
1da177e4 | 2149 | sector_t stride, size; |
dab8b292 | 2150 | int err = -EINVAL; |
1da177e4 | 2151 | |
f73ea873 MT |
2152 | if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) || |
2153 | !is_power_of_2(mddev->new_chunk_sectors)) { | |
128595ed N |
2154 | printk(KERN_ERR "md/raid10:%s: chunk size must be " |
2155 | "at least PAGE_SIZE(%ld) and be a power of 2.\n", | |
2156 | mdname(mddev), PAGE_SIZE); | |
dab8b292 | 2157 | goto out; |
1da177e4 | 2158 | } |
2604b703 | 2159 | |
f73ea873 MT |
2160 | nc = mddev->new_layout & 255; |
2161 | fc = (mddev->new_layout >> 8) & 255; | |
2162 | fo = mddev->new_layout & (1<<16); | |
dab8b292 | 2163 | |
1da177e4 | 2164 | if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks || |
f73ea873 | 2165 | (mddev->new_layout >> 17)) { |
128595ed | 2166 | printk(KERN_ERR "md/raid10:%s: unsupported raid10 layout: 0x%8x\n", |
f73ea873 | 2167 | mdname(mddev), mddev->new_layout); |
1da177e4 LT |
2168 | goto out; |
2169 | } | |
dab8b292 TM |
2170 | |
2171 | err = -ENOMEM; | |
4443ae10 | 2172 | conf = kzalloc(sizeof(conf_t), GFP_KERNEL); |
dab8b292 | 2173 | if (!conf) |
1da177e4 | 2174 | goto out; |
dab8b292 | 2175 | |
4443ae10 | 2176 | conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks, |
dab8b292 TM |
2177 | GFP_KERNEL); |
2178 | if (!conf->mirrors) | |
2179 | goto out; | |
4443ae10 N |
2180 | |
2181 | conf->tmppage = alloc_page(GFP_KERNEL); | |
2182 | if (!conf->tmppage) | |
dab8b292 TM |
2183 | goto out; |
2184 | ||
1da177e4 | 2185 | |
64a742bc | 2186 | conf->raid_disks = mddev->raid_disks; |
1da177e4 LT |
2187 | conf->near_copies = nc; |
2188 | conf->far_copies = fc; | |
2189 | conf->copies = nc*fc; | |
c93983bf | 2190 | conf->far_offset = fo; |
dab8b292 TM |
2191 | conf->chunk_mask = mddev->new_chunk_sectors - 1; |
2192 | conf->chunk_shift = ffz(~mddev->new_chunk_sectors); | |
2193 | ||
2194 | conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc, | |
2195 | r10bio_pool_free, conf); | |
2196 | if (!conf->r10bio_pool) | |
2197 | goto out; | |
2198 | ||
58c0fed4 | 2199 | size = mddev->dev_sectors >> conf->chunk_shift; |
64a742bc N |
2200 | sector_div(size, fc); |
2201 | size = size * conf->raid_disks; | |
2202 | sector_div(size, nc); | |
2203 | /* 'size' is now the number of chunks in the array */ | |
2204 | /* calculate "used chunks per device" in 'stride' */ | |
2205 | stride = size * conf->copies; | |
af03b8e4 N |
2206 | |
2207 | /* We need to round up when dividing by raid_disks to | |
2208 | * get the stride size. | |
2209 | */ | |
2210 | stride += conf->raid_disks - 1; | |
64a742bc | 2211 | sector_div(stride, conf->raid_disks); |
dab8b292 TM |
2212 | |
2213 | conf->dev_sectors = stride << conf->chunk_shift; | |
64a742bc | 2214 | |
c93983bf | 2215 | if (fo) |
64a742bc N |
2216 | stride = 1; |
2217 | else | |
c93983bf | 2218 | sector_div(stride, fc); |
64a742bc N |
2219 | conf->stride = stride << conf->chunk_shift; |
2220 | ||
1da177e4 | 2221 | |
e7e72bf6 | 2222 | spin_lock_init(&conf->device_lock); |
dab8b292 TM |
2223 | INIT_LIST_HEAD(&conf->retry_list); |
2224 | ||
2225 | spin_lock_init(&conf->resync_lock); | |
2226 | init_waitqueue_head(&conf->wait_barrier); | |
2227 | ||
2228 | conf->thread = md_register_thread(raid10d, mddev, NULL); | |
2229 | if (!conf->thread) | |
2230 | goto out; | |
2231 | ||
dab8b292 TM |
2232 | conf->mddev = mddev; |
2233 | return conf; | |
2234 | ||
2235 | out: | |
128595ed | 2236 | printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n", |
dab8b292 TM |
2237 | mdname(mddev)); |
2238 | if (conf) { | |
2239 | if (conf->r10bio_pool) | |
2240 | mempool_destroy(conf->r10bio_pool); | |
2241 | kfree(conf->mirrors); | |
2242 | safe_put_page(conf->tmppage); | |
2243 | kfree(conf); | |
2244 | } | |
2245 | return ERR_PTR(err); | |
2246 | } | |
2247 | ||
2248 | static int run(mddev_t *mddev) | |
2249 | { | |
2250 | conf_t *conf; | |
2251 | int i, disk_idx, chunk_size; | |
2252 | mirror_info_t *disk; | |
2253 | mdk_rdev_t *rdev; | |
2254 | sector_t size; | |
2255 | ||
2256 | /* | |
2257 | * copy the already verified devices into our private RAID10 | |
2258 | * bookkeeping area. [whatever we allocate in run(), | |
2259 | * should be freed in stop()] | |
2260 | */ | |
2261 | ||
2262 | if (mddev->private == NULL) { | |
2263 | conf = setup_conf(mddev); | |
2264 | if (IS_ERR(conf)) | |
2265 | return PTR_ERR(conf); | |
2266 | mddev->private = conf; | |
2267 | } | |
2268 | conf = mddev->private; | |
2269 | if (!conf) | |
2270 | goto out; | |
2271 | ||
dab8b292 TM |
2272 | mddev->thread = conf->thread; |
2273 | conf->thread = NULL; | |
2274 | ||
8f6c2e4b MP |
2275 | chunk_size = mddev->chunk_sectors << 9; |
2276 | blk_queue_io_min(mddev->queue, chunk_size); | |
2277 | if (conf->raid_disks % conf->near_copies) | |
2278 | blk_queue_io_opt(mddev->queue, chunk_size * conf->raid_disks); | |
2279 | else | |
2280 | blk_queue_io_opt(mddev->queue, chunk_size * | |
2281 | (conf->raid_disks / conf->near_copies)); | |
2282 | ||
159ec1fc | 2283 | list_for_each_entry(rdev, &mddev->disks, same_set) { |
34b343cf N |
2284 | |
2285 | if (rdev->badblocks.count) { | |
2286 | printk(KERN_ERR "md/raid10: cannot handle bad blocks yet\n"); | |
2287 | goto out_free_conf; | |
2288 | } | |
1da177e4 | 2289 | disk_idx = rdev->raid_disk; |
84707f38 | 2290 | if (disk_idx >= conf->raid_disks |
1da177e4 LT |
2291 | || disk_idx < 0) |
2292 | continue; | |
2293 | disk = conf->mirrors + disk_idx; | |
2294 | ||
2295 | disk->rdev = rdev; | |
8f6c2e4b MP |
2296 | disk_stack_limits(mddev->gendisk, rdev->bdev, |
2297 | rdev->data_offset << 9); | |
1da177e4 | 2298 | /* as we don't honour merge_bvec_fn, we must never risk |
627a2d3c N |
2299 | * violating it, so limit max_segments to 1 lying |
2300 | * within a single page. | |
1da177e4 | 2301 | */ |
627a2d3c N |
2302 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn) { |
2303 | blk_queue_max_segments(mddev->queue, 1); | |
2304 | blk_queue_segment_boundary(mddev->queue, | |
2305 | PAGE_CACHE_SIZE - 1); | |
2306 | } | |
1da177e4 LT |
2307 | |
2308 | disk->head_position = 0; | |
1da177e4 | 2309 | } |
6d508242 | 2310 | /* need to check that every block has at least one working mirror */ |
700c7213 | 2311 | if (!enough(conf, -1)) { |
128595ed | 2312 | printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n", |
6d508242 | 2313 | mdname(mddev)); |
1da177e4 LT |
2314 | goto out_free_conf; |
2315 | } | |
2316 | ||
2317 | mddev->degraded = 0; | |
2318 | for (i = 0; i < conf->raid_disks; i++) { | |
2319 | ||
2320 | disk = conf->mirrors + i; | |
2321 | ||
5fd6c1dc | 2322 | if (!disk->rdev || |
2e333e89 | 2323 | !test_bit(In_sync, &disk->rdev->flags)) { |
1da177e4 LT |
2324 | disk->head_position = 0; |
2325 | mddev->degraded++; | |
8c2e870a NB |
2326 | if (disk->rdev) |
2327 | conf->fullsync = 1; | |
1da177e4 LT |
2328 | } |
2329 | } | |
2330 | ||
8c6ac868 | 2331 | if (mddev->recovery_cp != MaxSector) |
128595ed | 2332 | printk(KERN_NOTICE "md/raid10:%s: not clean" |
8c6ac868 AN |
2333 | " -- starting background reconstruction\n", |
2334 | mdname(mddev)); | |
1da177e4 | 2335 | printk(KERN_INFO |
128595ed | 2336 | "md/raid10:%s: active with %d out of %d devices\n", |
84707f38 N |
2337 | mdname(mddev), conf->raid_disks - mddev->degraded, |
2338 | conf->raid_disks); | |
1da177e4 LT |
2339 | /* |
2340 | * Ok, everything is just fine now | |
2341 | */ | |
dab8b292 TM |
2342 | mddev->dev_sectors = conf->dev_sectors; |
2343 | size = raid10_size(mddev, 0, 0); | |
2344 | md_set_array_sectors(mddev, size); | |
2345 | mddev->resync_max_sectors = size; | |
1da177e4 | 2346 | |
0d129228 N |
2347 | mddev->queue->backing_dev_info.congested_fn = raid10_congested; |
2348 | mddev->queue->backing_dev_info.congested_data = mddev; | |
7a5febe9 | 2349 | |
1da177e4 LT |
2350 | /* Calculate max read-ahead size. |
2351 | * We need to readahead at least twice a whole stripe.... | |
2352 | * maybe... | |
2353 | */ | |
2354 | { | |
9d8f0363 AN |
2355 | int stripe = conf->raid_disks * |
2356 | ((mddev->chunk_sectors << 9) / PAGE_SIZE); | |
1da177e4 LT |
2357 | stripe /= conf->near_copies; |
2358 | if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) | |
2359 | mddev->queue->backing_dev_info.ra_pages = 2* stripe; | |
2360 | } | |
2361 | ||
84707f38 | 2362 | if (conf->near_copies < conf->raid_disks) |
1da177e4 | 2363 | blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec); |
a91a2785 MP |
2364 | |
2365 | if (md_integrity_register(mddev)) | |
2366 | goto out_free_conf; | |
2367 | ||
1da177e4 LT |
2368 | return 0; |
2369 | ||
2370 | out_free_conf: | |
589a594b | 2371 | md_unregister_thread(mddev->thread); |
1da177e4 LT |
2372 | if (conf->r10bio_pool) |
2373 | mempool_destroy(conf->r10bio_pool); | |
1345b1d8 | 2374 | safe_put_page(conf->tmppage); |
990a8baf | 2375 | kfree(conf->mirrors); |
1da177e4 LT |
2376 | kfree(conf); |
2377 | mddev->private = NULL; | |
2378 | out: | |
2379 | return -EIO; | |
2380 | } | |
2381 | ||
2382 | static int stop(mddev_t *mddev) | |
2383 | { | |
070ec55d | 2384 | conf_t *conf = mddev->private; |
1da177e4 | 2385 | |
409c57f3 N |
2386 | raise_barrier(conf, 0); |
2387 | lower_barrier(conf); | |
2388 | ||
1da177e4 LT |
2389 | md_unregister_thread(mddev->thread); |
2390 | mddev->thread = NULL; | |
2391 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
2392 | if (conf->r10bio_pool) | |
2393 | mempool_destroy(conf->r10bio_pool); | |
990a8baf | 2394 | kfree(conf->mirrors); |
1da177e4 LT |
2395 | kfree(conf); |
2396 | mddev->private = NULL; | |
2397 | return 0; | |
2398 | } | |
2399 | ||
6cce3b23 N |
2400 | static void raid10_quiesce(mddev_t *mddev, int state) |
2401 | { | |
070ec55d | 2402 | conf_t *conf = mddev->private; |
6cce3b23 N |
2403 | |
2404 | switch(state) { | |
2405 | case 1: | |
2406 | raise_barrier(conf, 0); | |
2407 | break; | |
2408 | case 0: | |
2409 | lower_barrier(conf); | |
2410 | break; | |
2411 | } | |
6cce3b23 | 2412 | } |
1da177e4 | 2413 | |
dab8b292 TM |
2414 | static void *raid10_takeover_raid0(mddev_t *mddev) |
2415 | { | |
2416 | mdk_rdev_t *rdev; | |
2417 | conf_t *conf; | |
2418 | ||
2419 | if (mddev->degraded > 0) { | |
128595ed N |
2420 | printk(KERN_ERR "md/raid10:%s: Error: degraded raid0!\n", |
2421 | mdname(mddev)); | |
dab8b292 TM |
2422 | return ERR_PTR(-EINVAL); |
2423 | } | |
2424 | ||
dab8b292 TM |
2425 | /* Set new parameters */ |
2426 | mddev->new_level = 10; | |
2427 | /* new layout: far_copies = 1, near_copies = 2 */ | |
2428 | mddev->new_layout = (1<<8) + 2; | |
2429 | mddev->new_chunk_sectors = mddev->chunk_sectors; | |
2430 | mddev->delta_disks = mddev->raid_disks; | |
dab8b292 TM |
2431 | mddev->raid_disks *= 2; |
2432 | /* make sure it will be not marked as dirty */ | |
2433 | mddev->recovery_cp = MaxSector; | |
2434 | ||
2435 | conf = setup_conf(mddev); | |
02214dc5 | 2436 | if (!IS_ERR(conf)) { |
e93f68a1 N |
2437 | list_for_each_entry(rdev, &mddev->disks, same_set) |
2438 | if (rdev->raid_disk >= 0) | |
2439 | rdev->new_raid_disk = rdev->raid_disk * 2; | |
02214dc5 KW |
2440 | conf->barrier = 1; |
2441 | } | |
2442 | ||
dab8b292 TM |
2443 | return conf; |
2444 | } | |
2445 | ||
2446 | static void *raid10_takeover(mddev_t *mddev) | |
2447 | { | |
2448 | struct raid0_private_data *raid0_priv; | |
2449 | ||
2450 | /* raid10 can take over: | |
2451 | * raid0 - providing it has only two drives | |
2452 | */ | |
2453 | if (mddev->level == 0) { | |
2454 | /* for raid0 takeover only one zone is supported */ | |
2455 | raid0_priv = mddev->private; | |
2456 | if (raid0_priv->nr_strip_zones > 1) { | |
128595ed N |
2457 | printk(KERN_ERR "md/raid10:%s: cannot takeover raid 0" |
2458 | " with more than one zone.\n", | |
2459 | mdname(mddev)); | |
dab8b292 TM |
2460 | return ERR_PTR(-EINVAL); |
2461 | } | |
2462 | return raid10_takeover_raid0(mddev); | |
2463 | } | |
2464 | return ERR_PTR(-EINVAL); | |
2465 | } | |
2466 | ||
2604b703 | 2467 | static struct mdk_personality raid10_personality = |
1da177e4 LT |
2468 | { |
2469 | .name = "raid10", | |
2604b703 | 2470 | .level = 10, |
1da177e4 LT |
2471 | .owner = THIS_MODULE, |
2472 | .make_request = make_request, | |
2473 | .run = run, | |
2474 | .stop = stop, | |
2475 | .status = status, | |
2476 | .error_handler = error, | |
2477 | .hot_add_disk = raid10_add_disk, | |
2478 | .hot_remove_disk= raid10_remove_disk, | |
2479 | .spare_active = raid10_spare_active, | |
2480 | .sync_request = sync_request, | |
6cce3b23 | 2481 | .quiesce = raid10_quiesce, |
80c3a6ce | 2482 | .size = raid10_size, |
dab8b292 | 2483 | .takeover = raid10_takeover, |
1da177e4 LT |
2484 | }; |
2485 | ||
2486 | static int __init raid_init(void) | |
2487 | { | |
2604b703 | 2488 | return register_md_personality(&raid10_personality); |
1da177e4 LT |
2489 | } |
2490 | ||
2491 | static void raid_exit(void) | |
2492 | { | |
2604b703 | 2493 | unregister_md_personality(&raid10_personality); |
1da177e4 LT |
2494 | } |
2495 | ||
2496 | module_init(raid_init); | |
2497 | module_exit(raid_exit); | |
2498 | MODULE_LICENSE("GPL"); | |
0efb9e61 | 2499 | MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD"); |
1da177e4 | 2500 | MODULE_ALIAS("md-personality-9"); /* RAID10 */ |
d9d166c2 | 2501 | MODULE_ALIAS("md-raid10"); |
2604b703 | 2502 | MODULE_ALIAS("md-level-10"); |