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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 | * | |
8 | * Base on code in raid1.c. See raid1.c for futher copyright information. | |
9 | * | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License as published by | |
13 | * the Free Software Foundation; either version 2, or (at your option) | |
14 | * any later version. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * (for example /usr/src/linux/COPYING); if not, write to the Free | |
18 | * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
20 | ||
25570727 | 21 | #include <linux/delay.h> |
bff61975 | 22 | #include <linux/blkdev.h> |
bff61975 | 23 | #include <linux/seq_file.h> |
43b2e5d8 | 24 | #include "md.h" |
ef740c37 CH |
25 | #include "raid10.h" |
26 | #include "bitmap.h" | |
1da177e4 LT |
27 | |
28 | /* | |
29 | * RAID10 provides a combination of RAID0 and RAID1 functionality. | |
30 | * The layout of data is defined by | |
31 | * chunk_size | |
32 | * raid_disks | |
33 | * near_copies (stored in low byte of layout) | |
34 | * far_copies (stored in second byte of layout) | |
c93983bf | 35 | * far_offset (stored in bit 16 of layout ) |
1da177e4 LT |
36 | * |
37 | * The data to be stored is divided into chunks using chunksize. | |
38 | * Each device is divided into far_copies sections. | |
39 | * In each section, chunks are laid out in a style similar to raid0, but | |
40 | * near_copies copies of each chunk is stored (each on a different drive). | |
41 | * The starting device for each section is offset near_copies from the starting | |
42 | * device of the previous section. | |
c93983bf | 43 | * Thus they are (near_copies*far_copies) of each chunk, and each is on a different |
1da177e4 LT |
44 | * drive. |
45 | * near_copies and far_copies must be at least one, and their product is at most | |
46 | * raid_disks. | |
c93983bf N |
47 | * |
48 | * If far_offset is true, then the far_copies are handled a bit differently. | |
49 | * The copies are still in different stripes, but instead of be very far apart | |
50 | * on disk, there are adjacent stripes. | |
1da177e4 LT |
51 | */ |
52 | ||
53 | /* | |
54 | * Number of guaranteed r10bios in case of extreme VM load: | |
55 | */ | |
56 | #define NR_RAID10_BIOS 256 | |
57 | ||
58 | static void unplug_slaves(mddev_t *mddev); | |
59 | ||
0a27ec96 N |
60 | static void allow_barrier(conf_t *conf); |
61 | static void lower_barrier(conf_t *conf); | |
62 | ||
dd0fc66f | 63 | static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
64 | { |
65 | conf_t *conf = data; | |
66 | r10bio_t *r10_bio; | |
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 */ | |
9ffae0cf N |
70 | r10_bio = kzalloc(size, gfp_flags); |
71 | if (!r10_bio) | |
1da177e4 LT |
72 | unplug_slaves(conf->mddev); |
73 | ||
74 | return r10_bio; | |
75 | } | |
76 | ||
77 | static void r10bio_pool_free(void *r10_bio, void *data) | |
78 | { | |
79 | kfree(r10_bio); | |
80 | } | |
81 | ||
0310fa21 | 82 | /* Maximum size of each resync request */ |
1da177e4 | 83 | #define RESYNC_BLOCK_SIZE (64*1024) |
1da177e4 | 84 | #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) |
0310fa21 N |
85 | /* amount of memory to reserve for resync requests */ |
86 | #define RESYNC_WINDOW (1024*1024) | |
87 | /* maximum number of concurrent requests, memory permitting */ | |
88 | #define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE) | |
1da177e4 LT |
89 | |
90 | /* | |
91 | * When performing a resync, we need to read and compare, so | |
92 | * we need as many pages are there are copies. | |
93 | * When performing a recovery, we need 2 bios, one for read, | |
94 | * one for write (we recover only one drive per r10buf) | |
95 | * | |
96 | */ | |
dd0fc66f | 97 | static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
98 | { |
99 | conf_t *conf = data; | |
100 | struct page *page; | |
101 | r10bio_t *r10_bio; | |
102 | struct bio *bio; | |
103 | int i, j; | |
104 | int nalloc; | |
105 | ||
106 | r10_bio = r10bio_pool_alloc(gfp_flags, conf); | |
107 | if (!r10_bio) { | |
108 | unplug_slaves(conf->mddev); | |
109 | return NULL; | |
110 | } | |
111 | ||
112 | if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery)) | |
113 | nalloc = conf->copies; /* resync */ | |
114 | else | |
115 | nalloc = 2; /* recovery */ | |
116 | ||
117 | /* | |
118 | * Allocate bios. | |
119 | */ | |
120 | for (j = nalloc ; j-- ; ) { | |
121 | bio = bio_alloc(gfp_flags, RESYNC_PAGES); | |
122 | if (!bio) | |
123 | goto out_free_bio; | |
124 | r10_bio->devs[j].bio = bio; | |
125 | } | |
126 | /* | |
127 | * Allocate RESYNC_PAGES data pages and attach them | |
128 | * where needed. | |
129 | */ | |
130 | for (j = 0 ; j < nalloc; j++) { | |
131 | bio = r10_bio->devs[j].bio; | |
132 | for (i = 0; i < RESYNC_PAGES; i++) { | |
133 | page = alloc_page(gfp_flags); | |
134 | if (unlikely(!page)) | |
135 | goto out_free_pages; | |
136 | ||
137 | bio->bi_io_vec[i].bv_page = page; | |
138 | } | |
139 | } | |
140 | ||
141 | return r10_bio; | |
142 | ||
143 | out_free_pages: | |
144 | for ( ; i > 0 ; i--) | |
1345b1d8 | 145 | safe_put_page(bio->bi_io_vec[i-1].bv_page); |
1da177e4 LT |
146 | while (j--) |
147 | for (i = 0; i < RESYNC_PAGES ; i++) | |
1345b1d8 | 148 | safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page); |
1da177e4 LT |
149 | j = -1; |
150 | out_free_bio: | |
151 | while ( ++j < nalloc ) | |
152 | bio_put(r10_bio->devs[j].bio); | |
153 | r10bio_pool_free(r10_bio, conf); | |
154 | return NULL; | |
155 | } | |
156 | ||
157 | static void r10buf_pool_free(void *__r10_bio, void *data) | |
158 | { | |
159 | int i; | |
160 | conf_t *conf = data; | |
161 | r10bio_t *r10bio = __r10_bio; | |
162 | int j; | |
163 | ||
164 | for (j=0; j < conf->copies; j++) { | |
165 | struct bio *bio = r10bio->devs[j].bio; | |
166 | if (bio) { | |
167 | for (i = 0; i < RESYNC_PAGES; i++) { | |
1345b1d8 | 168 | safe_put_page(bio->bi_io_vec[i].bv_page); |
1da177e4 LT |
169 | bio->bi_io_vec[i].bv_page = NULL; |
170 | } | |
171 | bio_put(bio); | |
172 | } | |
173 | } | |
174 | r10bio_pool_free(r10bio, conf); | |
175 | } | |
176 | ||
177 | static void put_all_bios(conf_t *conf, r10bio_t *r10_bio) | |
178 | { | |
179 | int i; | |
180 | ||
181 | for (i = 0; i < conf->copies; i++) { | |
182 | struct bio **bio = & r10_bio->devs[i].bio; | |
0eb3ff12 | 183 | if (*bio && *bio != IO_BLOCKED) |
1da177e4 LT |
184 | bio_put(*bio); |
185 | *bio = NULL; | |
186 | } | |
187 | } | |
188 | ||
858119e1 | 189 | static void free_r10bio(r10bio_t *r10_bio) |
1da177e4 | 190 | { |
070ec55d | 191 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 LT |
192 | |
193 | /* | |
194 | * Wake up any possible resync thread that waits for the device | |
195 | * to go idle. | |
196 | */ | |
0a27ec96 | 197 | allow_barrier(conf); |
1da177e4 LT |
198 | |
199 | put_all_bios(conf, r10_bio); | |
200 | mempool_free(r10_bio, conf->r10bio_pool); | |
201 | } | |
202 | ||
858119e1 | 203 | static void put_buf(r10bio_t *r10_bio) |
1da177e4 | 204 | { |
070ec55d | 205 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 LT |
206 | |
207 | mempool_free(r10_bio, conf->r10buf_pool); | |
208 | ||
0a27ec96 | 209 | lower_barrier(conf); |
1da177e4 LT |
210 | } |
211 | ||
212 | static void reschedule_retry(r10bio_t *r10_bio) | |
213 | { | |
214 | unsigned long flags; | |
215 | mddev_t *mddev = r10_bio->mddev; | |
070ec55d | 216 | conf_t *conf = mddev->private; |
1da177e4 LT |
217 | |
218 | spin_lock_irqsave(&conf->device_lock, flags); | |
219 | list_add(&r10_bio->retry_list, &conf->retry_list); | |
4443ae10 | 220 | conf->nr_queued ++; |
1da177e4 LT |
221 | spin_unlock_irqrestore(&conf->device_lock, flags); |
222 | ||
388667be AJ |
223 | /* wake up frozen array... */ |
224 | wake_up(&conf->wait_barrier); | |
225 | ||
1da177e4 LT |
226 | md_wakeup_thread(mddev->thread); |
227 | } | |
228 | ||
229 | /* | |
230 | * raid_end_bio_io() is called when we have finished servicing a mirrored | |
231 | * operation and are ready to return a success/failure code to the buffer | |
232 | * cache layer. | |
233 | */ | |
234 | static void raid_end_bio_io(r10bio_t *r10_bio) | |
235 | { | |
236 | struct bio *bio = r10_bio->master_bio; | |
237 | ||
6712ecf8 | 238 | bio_endio(bio, |
1da177e4 LT |
239 | test_bit(R10BIO_Uptodate, &r10_bio->state) ? 0 : -EIO); |
240 | free_r10bio(r10_bio); | |
241 | } | |
242 | ||
243 | /* | |
244 | * Update disk head position estimator based on IRQ completion info. | |
245 | */ | |
246 | static inline void update_head_pos(int slot, r10bio_t *r10_bio) | |
247 | { | |
070ec55d | 248 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 LT |
249 | |
250 | conf->mirrors[r10_bio->devs[slot].devnum].head_position = | |
251 | r10_bio->devs[slot].addr + (r10_bio->sectors); | |
252 | } | |
253 | ||
6712ecf8 | 254 | static void raid10_end_read_request(struct bio *bio, int error) |
1da177e4 LT |
255 | { |
256 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
257 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
258 | int slot, dev; | |
070ec55d | 259 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 | 260 | |
1da177e4 LT |
261 | |
262 | slot = r10_bio->read_slot; | |
263 | dev = r10_bio->devs[slot].devnum; | |
264 | /* | |
265 | * this branch is our 'one mirror IO has finished' event handler: | |
266 | */ | |
4443ae10 N |
267 | update_head_pos(slot, r10_bio); |
268 | ||
269 | if (uptodate) { | |
1da177e4 LT |
270 | /* |
271 | * Set R10BIO_Uptodate in our master bio, so that | |
272 | * we will return a good error code to the higher | |
273 | * levels even if IO on some other mirrored buffer fails. | |
274 | * | |
275 | * The 'master' represents the composite IO operation to | |
276 | * user-side. So if something waits for IO, then it will | |
277 | * wait for the 'master' bio. | |
278 | */ | |
279 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
1da177e4 | 280 | raid_end_bio_io(r10_bio); |
4443ae10 | 281 | } else { |
1da177e4 LT |
282 | /* |
283 | * oops, read error: | |
284 | */ | |
285 | char b[BDEVNAME_SIZE]; | |
286 | if (printk_ratelimit()) | |
287 | printk(KERN_ERR "raid10: %s: rescheduling sector %llu\n", | |
288 | bdevname(conf->mirrors[dev].rdev->bdev,b), (unsigned long long)r10_bio->sector); | |
289 | reschedule_retry(r10_bio); | |
290 | } | |
291 | ||
292 | rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev); | |
1da177e4 LT |
293 | } |
294 | ||
6712ecf8 | 295 | static void raid10_end_write_request(struct bio *bio, int error) |
1da177e4 LT |
296 | { |
297 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
298 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
299 | int slot, dev; | |
070ec55d | 300 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 | 301 | |
1da177e4 LT |
302 | for (slot = 0; slot < conf->copies; slot++) |
303 | if (r10_bio->devs[slot].bio == bio) | |
304 | break; | |
305 | dev = r10_bio->devs[slot].devnum; | |
306 | ||
307 | /* | |
308 | * this branch is our 'one mirror IO has finished' event handler: | |
309 | */ | |
6cce3b23 | 310 | if (!uptodate) { |
1da177e4 | 311 | md_error(r10_bio->mddev, conf->mirrors[dev].rdev); |
6cce3b23 N |
312 | /* an I/O failed, we can't clear the bitmap */ |
313 | set_bit(R10BIO_Degraded, &r10_bio->state); | |
314 | } else | |
1da177e4 LT |
315 | /* |
316 | * Set R10BIO_Uptodate in our master bio, so that | |
317 | * we will return a good error code for to the higher | |
318 | * levels even if IO on some other mirrored buffer fails. | |
319 | * | |
320 | * The 'master' represents the composite IO operation to | |
321 | * user-side. So if something waits for IO, then it will | |
322 | * wait for the 'master' bio. | |
323 | */ | |
324 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
325 | ||
326 | update_head_pos(slot, r10_bio); | |
327 | ||
328 | /* | |
329 | * | |
330 | * Let's see if all mirrored write operations have finished | |
331 | * already. | |
332 | */ | |
333 | if (atomic_dec_and_test(&r10_bio->remaining)) { | |
6cce3b23 N |
334 | /* clear the bitmap if all writes complete successfully */ |
335 | bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector, | |
336 | r10_bio->sectors, | |
337 | !test_bit(R10BIO_Degraded, &r10_bio->state), | |
338 | 0); | |
1da177e4 LT |
339 | md_write_end(r10_bio->mddev); |
340 | raid_end_bio_io(r10_bio); | |
341 | } | |
342 | ||
343 | rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev); | |
1da177e4 LT |
344 | } |
345 | ||
346 | ||
347 | /* | |
348 | * RAID10 layout manager | |
349 | * Aswell as the chunksize and raid_disks count, there are two | |
350 | * parameters: near_copies and far_copies. | |
351 | * near_copies * far_copies must be <= raid_disks. | |
352 | * Normally one of these will be 1. | |
353 | * If both are 1, we get raid0. | |
354 | * If near_copies == raid_disks, we get raid1. | |
355 | * | |
356 | * Chunks are layed out in raid0 style with near_copies copies of the | |
357 | * first chunk, followed by near_copies copies of the next chunk and | |
358 | * so on. | |
359 | * If far_copies > 1, then after 1/far_copies of the array has been assigned | |
360 | * as described above, we start again with a device offset of near_copies. | |
361 | * So we effectively have another copy of the whole array further down all | |
362 | * the drives, but with blocks on different drives. | |
363 | * With this layout, and block is never stored twice on the one device. | |
364 | * | |
365 | * raid10_find_phys finds the sector offset of a given virtual sector | |
c93983bf | 366 | * on each device that it is on. |
1da177e4 LT |
367 | * |
368 | * raid10_find_virt does the reverse mapping, from a device and a | |
369 | * sector offset to a virtual address | |
370 | */ | |
371 | ||
372 | static void raid10_find_phys(conf_t *conf, r10bio_t *r10bio) | |
373 | { | |
374 | int n,f; | |
375 | sector_t sector; | |
376 | sector_t chunk; | |
377 | sector_t stripe; | |
378 | int dev; | |
379 | ||
380 | int slot = 0; | |
381 | ||
382 | /* now calculate first sector/dev */ | |
383 | chunk = r10bio->sector >> conf->chunk_shift; | |
384 | sector = r10bio->sector & conf->chunk_mask; | |
385 | ||
386 | chunk *= conf->near_copies; | |
387 | stripe = chunk; | |
388 | dev = sector_div(stripe, conf->raid_disks); | |
c93983bf N |
389 | if (conf->far_offset) |
390 | stripe *= conf->far_copies; | |
1da177e4 LT |
391 | |
392 | sector += stripe << conf->chunk_shift; | |
393 | ||
394 | /* and calculate all the others */ | |
395 | for (n=0; n < conf->near_copies; n++) { | |
396 | int d = dev; | |
397 | sector_t s = sector; | |
398 | r10bio->devs[slot].addr = sector; | |
399 | r10bio->devs[slot].devnum = d; | |
400 | slot++; | |
401 | ||
402 | for (f = 1; f < conf->far_copies; f++) { | |
403 | d += conf->near_copies; | |
404 | if (d >= conf->raid_disks) | |
405 | d -= conf->raid_disks; | |
406 | s += conf->stride; | |
407 | r10bio->devs[slot].devnum = d; | |
408 | r10bio->devs[slot].addr = s; | |
409 | slot++; | |
410 | } | |
411 | dev++; | |
412 | if (dev >= conf->raid_disks) { | |
413 | dev = 0; | |
414 | sector += (conf->chunk_mask + 1); | |
415 | } | |
416 | } | |
417 | BUG_ON(slot != conf->copies); | |
418 | } | |
419 | ||
420 | static sector_t raid10_find_virt(conf_t *conf, sector_t sector, int dev) | |
421 | { | |
422 | sector_t offset, chunk, vchunk; | |
423 | ||
1da177e4 | 424 | offset = sector & conf->chunk_mask; |
c93983bf N |
425 | if (conf->far_offset) { |
426 | int fc; | |
427 | chunk = sector >> conf->chunk_shift; | |
428 | fc = sector_div(chunk, conf->far_copies); | |
429 | dev -= fc * conf->near_copies; | |
430 | if (dev < 0) | |
431 | dev += conf->raid_disks; | |
432 | } else { | |
64a742bc | 433 | while (sector >= conf->stride) { |
c93983bf N |
434 | sector -= conf->stride; |
435 | if (dev < conf->near_copies) | |
436 | dev += conf->raid_disks - conf->near_copies; | |
437 | else | |
438 | dev -= conf->near_copies; | |
439 | } | |
440 | chunk = sector >> conf->chunk_shift; | |
441 | } | |
1da177e4 LT |
442 | vchunk = chunk * conf->raid_disks + dev; |
443 | sector_div(vchunk, conf->near_copies); | |
444 | return (vchunk << conf->chunk_shift) + offset; | |
445 | } | |
446 | ||
447 | /** | |
448 | * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged | |
449 | * @q: request queue | |
cc371e66 | 450 | * @bvm: properties of new bio |
1da177e4 LT |
451 | * @biovec: the request that could be merged to it. |
452 | * | |
453 | * Return amount of bytes we can accept at this offset | |
454 | * If near_copies == raid_disk, there are no striping issues, | |
455 | * but in that case, the function isn't called at all. | |
456 | */ | |
cc371e66 AK |
457 | static int raid10_mergeable_bvec(struct request_queue *q, |
458 | struct bvec_merge_data *bvm, | |
459 | struct bio_vec *biovec) | |
1da177e4 LT |
460 | { |
461 | mddev_t *mddev = q->queuedata; | |
cc371e66 | 462 | sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); |
1da177e4 | 463 | int max; |
9d8f0363 | 464 | unsigned int chunk_sectors = mddev->chunk_sectors; |
cc371e66 | 465 | unsigned int bio_sectors = bvm->bi_size >> 9; |
1da177e4 LT |
466 | |
467 | max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; | |
468 | if (max < 0) max = 0; /* bio_add cannot handle a negative return */ | |
cc371e66 AK |
469 | if (max <= biovec->bv_len && bio_sectors == 0) |
470 | return biovec->bv_len; | |
1da177e4 LT |
471 | else |
472 | return max; | |
473 | } | |
474 | ||
475 | /* | |
476 | * This routine returns the disk from which the requested read should | |
477 | * be done. There is a per-array 'next expected sequential IO' sector | |
478 | * number - if this matches on the next IO then we use the last disk. | |
479 | * There is also a per-disk 'last know head position' sector that is | |
480 | * maintained from IRQ contexts, both the normal and the resync IO | |
481 | * completion handlers update this position correctly. If there is no | |
482 | * perfect sequential match then we pick the disk whose head is closest. | |
483 | * | |
484 | * If there are 2 mirrors in the same 2 devices, performance degrades | |
485 | * because position is mirror, not device based. | |
486 | * | |
487 | * The rdev for the device selected will have nr_pending incremented. | |
488 | */ | |
489 | ||
490 | /* | |
491 | * FIXME: possibly should rethink readbalancing and do it differently | |
492 | * depending on near_copies / far_copies geometry. | |
493 | */ | |
494 | static int read_balance(conf_t *conf, r10bio_t *r10_bio) | |
495 | { | |
496 | const unsigned long this_sector = r10_bio->sector; | |
497 | int disk, slot, nslot; | |
498 | const int sectors = r10_bio->sectors; | |
499 | sector_t new_distance, current_distance; | |
d6065f7b | 500 | mdk_rdev_t *rdev; |
1da177e4 LT |
501 | |
502 | raid10_find_phys(conf, r10_bio); | |
503 | rcu_read_lock(); | |
504 | /* | |
505 | * Check if we can balance. We can balance on the whole | |
6cce3b23 N |
506 | * device if no resync is going on (recovery is ok), or below |
507 | * the resync window. We take the first readable disk when | |
508 | * above the resync window. | |
1da177e4 LT |
509 | */ |
510 | if (conf->mddev->recovery_cp < MaxSector | |
511 | && (this_sector + sectors >= conf->next_resync)) { | |
512 | /* make sure that disk is operational */ | |
513 | slot = 0; | |
514 | disk = r10_bio->devs[slot].devnum; | |
515 | ||
d6065f7b | 516 | while ((rdev = rcu_dereference(conf->mirrors[disk].rdev)) == NULL || |
0eb3ff12 | 517 | r10_bio->devs[slot].bio == IO_BLOCKED || |
b2d444d7 | 518 | !test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
519 | slot++; |
520 | if (slot == conf->copies) { | |
521 | slot = 0; | |
522 | disk = -1; | |
523 | break; | |
524 | } | |
525 | disk = r10_bio->devs[slot].devnum; | |
526 | } | |
527 | goto rb_out; | |
528 | } | |
529 | ||
530 | ||
531 | /* make sure the disk is operational */ | |
532 | slot = 0; | |
533 | disk = r10_bio->devs[slot].devnum; | |
d6065f7b | 534 | while ((rdev=rcu_dereference(conf->mirrors[disk].rdev)) == NULL || |
0eb3ff12 | 535 | r10_bio->devs[slot].bio == IO_BLOCKED || |
b2d444d7 | 536 | !test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
537 | slot ++; |
538 | if (slot == conf->copies) { | |
539 | disk = -1; | |
540 | goto rb_out; | |
541 | } | |
542 | disk = r10_bio->devs[slot].devnum; | |
543 | } | |
544 | ||
545 | ||
3ec67ac1 N |
546 | current_distance = abs(r10_bio->devs[slot].addr - |
547 | conf->mirrors[disk].head_position); | |
1da177e4 | 548 | |
8ed3a195 KS |
549 | /* Find the disk whose head is closest, |
550 | * or - for far > 1 - find the closest to partition beginning */ | |
1da177e4 LT |
551 | |
552 | for (nslot = slot; nslot < conf->copies; nslot++) { | |
553 | int ndisk = r10_bio->devs[nslot].devnum; | |
554 | ||
555 | ||
d6065f7b | 556 | if ((rdev=rcu_dereference(conf->mirrors[ndisk].rdev)) == NULL || |
0eb3ff12 | 557 | r10_bio->devs[nslot].bio == IO_BLOCKED || |
b2d444d7 | 558 | !test_bit(In_sync, &rdev->flags)) |
1da177e4 LT |
559 | continue; |
560 | ||
22dfdf52 N |
561 | /* This optimisation is debatable, and completely destroys |
562 | * sequential read speed for 'far copies' arrays. So only | |
563 | * keep it for 'near' arrays, and review those later. | |
564 | */ | |
565 | if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) { | |
1da177e4 LT |
566 | disk = ndisk; |
567 | slot = nslot; | |
568 | break; | |
569 | } | |
8ed3a195 KS |
570 | |
571 | /* for far > 1 always use the lowest address */ | |
572 | if (conf->far_copies > 1) | |
573 | new_distance = r10_bio->devs[nslot].addr; | |
574 | else | |
575 | new_distance = abs(r10_bio->devs[nslot].addr - | |
576 | conf->mirrors[ndisk].head_position); | |
1da177e4 LT |
577 | if (new_distance < current_distance) { |
578 | current_distance = new_distance; | |
579 | disk = ndisk; | |
580 | slot = nslot; | |
581 | } | |
582 | } | |
583 | ||
584 | rb_out: | |
585 | r10_bio->read_slot = slot; | |
586 | /* conf->next_seq_sect = this_sector + sectors;*/ | |
587 | ||
d6065f7b | 588 | if (disk >= 0 && (rdev=rcu_dereference(conf->mirrors[disk].rdev))!= NULL) |
1da177e4 | 589 | atomic_inc(&conf->mirrors[disk].rdev->nr_pending); |
29fc7e3e N |
590 | else |
591 | disk = -1; | |
1da177e4 LT |
592 | rcu_read_unlock(); |
593 | ||
594 | return disk; | |
595 | } | |
596 | ||
597 | static void unplug_slaves(mddev_t *mddev) | |
598 | { | |
070ec55d | 599 | conf_t *conf = mddev->private; |
1da177e4 LT |
600 | int i; |
601 | ||
602 | rcu_read_lock(); | |
603 | for (i=0; i<mddev->raid_disks; i++) { | |
d6065f7b | 604 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); |
b2d444d7 | 605 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { |
165125e1 | 606 | struct request_queue *r_queue = bdev_get_queue(rdev->bdev); |
1da177e4 LT |
607 | |
608 | atomic_inc(&rdev->nr_pending); | |
609 | rcu_read_unlock(); | |
610 | ||
2ad8b1ef | 611 | blk_unplug(r_queue); |
1da177e4 LT |
612 | |
613 | rdev_dec_pending(rdev, mddev); | |
614 | rcu_read_lock(); | |
615 | } | |
616 | } | |
617 | rcu_read_unlock(); | |
618 | } | |
619 | ||
165125e1 | 620 | static void raid10_unplug(struct request_queue *q) |
1da177e4 | 621 | { |
6cce3b23 N |
622 | mddev_t *mddev = q->queuedata; |
623 | ||
1da177e4 | 624 | unplug_slaves(q->queuedata); |
6cce3b23 | 625 | md_wakeup_thread(mddev->thread); |
1da177e4 LT |
626 | } |
627 | ||
0d129228 N |
628 | static int raid10_congested(void *data, int bits) |
629 | { | |
630 | mddev_t *mddev = data; | |
070ec55d | 631 | conf_t *conf = mddev->private; |
0d129228 N |
632 | int i, ret = 0; |
633 | ||
634 | rcu_read_lock(); | |
635 | for (i = 0; i < mddev->raid_disks && ret == 0; i++) { | |
636 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); | |
637 | if (rdev && !test_bit(Faulty, &rdev->flags)) { | |
165125e1 | 638 | struct request_queue *q = bdev_get_queue(rdev->bdev); |
0d129228 N |
639 | |
640 | ret |= bdi_congested(&q->backing_dev_info, bits); | |
641 | } | |
642 | } | |
643 | rcu_read_unlock(); | |
644 | return ret; | |
645 | } | |
646 | ||
a35e63ef N |
647 | static int flush_pending_writes(conf_t *conf) |
648 | { | |
649 | /* Any writes that have been queued but are awaiting | |
650 | * bitmap updates get flushed here. | |
651 | * We return 1 if any requests were actually submitted. | |
652 | */ | |
653 | int rv = 0; | |
654 | ||
655 | spin_lock_irq(&conf->device_lock); | |
656 | ||
657 | if (conf->pending_bio_list.head) { | |
658 | struct bio *bio; | |
659 | bio = bio_list_get(&conf->pending_bio_list); | |
660 | blk_remove_plug(conf->mddev->queue); | |
661 | spin_unlock_irq(&conf->device_lock); | |
662 | /* flush any pending bitmap writes to disk | |
663 | * before proceeding w/ I/O */ | |
664 | bitmap_unplug(conf->mddev->bitmap); | |
665 | ||
666 | while (bio) { /* submit pending writes */ | |
667 | struct bio *next = bio->bi_next; | |
668 | bio->bi_next = NULL; | |
669 | generic_make_request(bio); | |
670 | bio = next; | |
671 | } | |
672 | rv = 1; | |
673 | } else | |
674 | spin_unlock_irq(&conf->device_lock); | |
675 | return rv; | |
676 | } | |
0a27ec96 N |
677 | /* Barriers.... |
678 | * Sometimes we need to suspend IO while we do something else, | |
679 | * either some resync/recovery, or reconfigure the array. | |
680 | * To do this we raise a 'barrier'. | |
681 | * The 'barrier' is a counter that can be raised multiple times | |
682 | * to count how many activities are happening which preclude | |
683 | * normal IO. | |
684 | * We can only raise the barrier if there is no pending IO. | |
685 | * i.e. if nr_pending == 0. | |
686 | * We choose only to raise the barrier if no-one is waiting for the | |
687 | * barrier to go down. This means that as soon as an IO request | |
688 | * is ready, no other operations which require a barrier will start | |
689 | * until the IO request has had a chance. | |
690 | * | |
691 | * So: regular IO calls 'wait_barrier'. When that returns there | |
692 | * is no backgroup IO happening, It must arrange to call | |
693 | * allow_barrier when it has finished its IO. | |
694 | * backgroup IO calls must call raise_barrier. Once that returns | |
695 | * there is no normal IO happeing. It must arrange to call | |
696 | * lower_barrier when the particular background IO completes. | |
1da177e4 | 697 | */ |
1da177e4 | 698 | |
6cce3b23 | 699 | static void raise_barrier(conf_t *conf, int force) |
1da177e4 | 700 | { |
6cce3b23 | 701 | BUG_ON(force && !conf->barrier); |
1da177e4 | 702 | spin_lock_irq(&conf->resync_lock); |
0a27ec96 | 703 | |
6cce3b23 N |
704 | /* Wait until no block IO is waiting (unless 'force') */ |
705 | wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting, | |
0a27ec96 N |
706 | conf->resync_lock, |
707 | raid10_unplug(conf->mddev->queue)); | |
708 | ||
709 | /* block any new IO from starting */ | |
710 | conf->barrier++; | |
711 | ||
712 | /* No wait for all pending IO to complete */ | |
713 | wait_event_lock_irq(conf->wait_barrier, | |
714 | !conf->nr_pending && conf->barrier < RESYNC_DEPTH, | |
715 | conf->resync_lock, | |
716 | raid10_unplug(conf->mddev->queue)); | |
717 | ||
718 | spin_unlock_irq(&conf->resync_lock); | |
719 | } | |
720 | ||
721 | static void lower_barrier(conf_t *conf) | |
722 | { | |
723 | unsigned long flags; | |
724 | spin_lock_irqsave(&conf->resync_lock, flags); | |
725 | conf->barrier--; | |
726 | spin_unlock_irqrestore(&conf->resync_lock, flags); | |
727 | wake_up(&conf->wait_barrier); | |
728 | } | |
729 | ||
730 | static void wait_barrier(conf_t *conf) | |
731 | { | |
732 | spin_lock_irq(&conf->resync_lock); | |
733 | if (conf->barrier) { | |
734 | conf->nr_waiting++; | |
735 | wait_event_lock_irq(conf->wait_barrier, !conf->barrier, | |
736 | conf->resync_lock, | |
737 | raid10_unplug(conf->mddev->queue)); | |
738 | conf->nr_waiting--; | |
1da177e4 | 739 | } |
0a27ec96 | 740 | conf->nr_pending++; |
1da177e4 LT |
741 | spin_unlock_irq(&conf->resync_lock); |
742 | } | |
743 | ||
0a27ec96 N |
744 | static void allow_barrier(conf_t *conf) |
745 | { | |
746 | unsigned long flags; | |
747 | spin_lock_irqsave(&conf->resync_lock, flags); | |
748 | conf->nr_pending--; | |
749 | spin_unlock_irqrestore(&conf->resync_lock, flags); | |
750 | wake_up(&conf->wait_barrier); | |
751 | } | |
752 | ||
4443ae10 N |
753 | static void freeze_array(conf_t *conf) |
754 | { | |
755 | /* stop syncio and normal IO and wait for everything to | |
f188593e | 756 | * go quiet. |
4443ae10 | 757 | * We increment barrier and nr_waiting, and then |
1c830532 N |
758 | * wait until nr_pending match nr_queued+1 |
759 | * This is called in the context of one normal IO request | |
760 | * that has failed. Thus any sync request that might be pending | |
761 | * will be blocked by nr_pending, and we need to wait for | |
762 | * pending IO requests to complete or be queued for re-try. | |
763 | * Thus the number queued (nr_queued) plus this request (1) | |
764 | * must match the number of pending IOs (nr_pending) before | |
765 | * we continue. | |
4443ae10 N |
766 | */ |
767 | spin_lock_irq(&conf->resync_lock); | |
768 | conf->barrier++; | |
769 | conf->nr_waiting++; | |
770 | wait_event_lock_irq(conf->wait_barrier, | |
1c830532 | 771 | conf->nr_pending == conf->nr_queued+1, |
4443ae10 | 772 | conf->resync_lock, |
a35e63ef N |
773 | ({ flush_pending_writes(conf); |
774 | raid10_unplug(conf->mddev->queue); })); | |
4443ae10 N |
775 | spin_unlock_irq(&conf->resync_lock); |
776 | } | |
777 | ||
778 | static void unfreeze_array(conf_t *conf) | |
779 | { | |
780 | /* reverse the effect of the freeze */ | |
781 | spin_lock_irq(&conf->resync_lock); | |
782 | conf->barrier--; | |
783 | conf->nr_waiting--; | |
784 | wake_up(&conf->wait_barrier); | |
785 | spin_unlock_irq(&conf->resync_lock); | |
786 | } | |
787 | ||
165125e1 | 788 | static int make_request(struct request_queue *q, struct bio * bio) |
1da177e4 LT |
789 | { |
790 | mddev_t *mddev = q->queuedata; | |
070ec55d | 791 | conf_t *conf = mddev->private; |
1da177e4 LT |
792 | mirror_info_t *mirror; |
793 | r10bio_t *r10_bio; | |
794 | struct bio *read_bio; | |
c9959059 | 795 | int cpu; |
1da177e4 LT |
796 | int i; |
797 | int chunk_sects = conf->chunk_mask + 1; | |
a362357b | 798 | const int rw = bio_data_dir(bio); |
e3881a68 | 799 | const int do_sync = bio_sync(bio); |
6cce3b23 N |
800 | struct bio_list bl; |
801 | unsigned long flags; | |
6bfe0b49 | 802 | mdk_rdev_t *blocked_rdev; |
1da177e4 | 803 | |
e5dcdd80 | 804 | if (unlikely(bio_barrier(bio))) { |
6712ecf8 | 805 | bio_endio(bio, -EOPNOTSUPP); |
e5dcdd80 N |
806 | return 0; |
807 | } | |
808 | ||
1da177e4 LT |
809 | /* If this request crosses a chunk boundary, we need to |
810 | * split it. This will only happen for 1 PAGE (or less) requests. | |
811 | */ | |
812 | if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9) | |
813 | > chunk_sects && | |
814 | conf->near_copies < conf->raid_disks)) { | |
815 | struct bio_pair *bp; | |
816 | /* Sanity check -- queue functions should prevent this happening */ | |
817 | if (bio->bi_vcnt != 1 || | |
818 | bio->bi_idx != 0) | |
819 | goto bad_map; | |
820 | /* This is a one page bio that upper layers | |
821 | * refuse to split for us, so we need to split it. | |
822 | */ | |
6feef531 | 823 | bp = bio_split(bio, |
1da177e4 LT |
824 | chunk_sects - (bio->bi_sector & (chunk_sects - 1)) ); |
825 | if (make_request(q, &bp->bio1)) | |
826 | generic_make_request(&bp->bio1); | |
827 | if (make_request(q, &bp->bio2)) | |
828 | generic_make_request(&bp->bio2); | |
829 | ||
830 | bio_pair_release(bp); | |
831 | return 0; | |
832 | bad_map: | |
833 | printk("raid10_make_request bug: can't convert block across chunks" | |
834 | " or bigger than %dk %llu %d\n", chunk_sects/2, | |
835 | (unsigned long long)bio->bi_sector, bio->bi_size >> 10); | |
836 | ||
6712ecf8 | 837 | bio_io_error(bio); |
1da177e4 LT |
838 | return 0; |
839 | } | |
840 | ||
3d310eb7 | 841 | md_write_start(mddev, bio); |
06d91a5f | 842 | |
1da177e4 LT |
843 | /* |
844 | * Register the new request and wait if the reconstruction | |
845 | * thread has put up a bar for new requests. | |
846 | * Continue immediately if no resync is active currently. | |
847 | */ | |
0a27ec96 | 848 | wait_barrier(conf); |
1da177e4 | 849 | |
074a7aca TH |
850 | cpu = part_stat_lock(); |
851 | part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]); | |
852 | part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], | |
853 | bio_sectors(bio)); | |
854 | part_stat_unlock(); | |
1da177e4 LT |
855 | |
856 | r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO); | |
857 | ||
858 | r10_bio->master_bio = bio; | |
859 | r10_bio->sectors = bio->bi_size >> 9; | |
860 | ||
861 | r10_bio->mddev = mddev; | |
862 | r10_bio->sector = bio->bi_sector; | |
6cce3b23 | 863 | r10_bio->state = 0; |
1da177e4 | 864 | |
a362357b | 865 | if (rw == READ) { |
1da177e4 LT |
866 | /* |
867 | * read balancing logic: | |
868 | */ | |
869 | int disk = read_balance(conf, r10_bio); | |
870 | int slot = r10_bio->read_slot; | |
871 | if (disk < 0) { | |
872 | raid_end_bio_io(r10_bio); | |
873 | return 0; | |
874 | } | |
875 | mirror = conf->mirrors + disk; | |
876 | ||
877 | read_bio = bio_clone(bio, GFP_NOIO); | |
878 | ||
879 | r10_bio->devs[slot].bio = read_bio; | |
880 | ||
881 | read_bio->bi_sector = r10_bio->devs[slot].addr + | |
882 | mirror->rdev->data_offset; | |
883 | read_bio->bi_bdev = mirror->rdev->bdev; | |
884 | read_bio->bi_end_io = raid10_end_read_request; | |
e3881a68 | 885 | read_bio->bi_rw = READ | do_sync; |
1da177e4 LT |
886 | read_bio->bi_private = r10_bio; |
887 | ||
888 | generic_make_request(read_bio); | |
889 | return 0; | |
890 | } | |
891 | ||
892 | /* | |
893 | * WRITE: | |
894 | */ | |
6bfe0b49 | 895 | /* first select target devices under rcu_lock and |
1da177e4 LT |
896 | * inc refcount on their rdev. Record them by setting |
897 | * bios[x] to bio | |
898 | */ | |
899 | raid10_find_phys(conf, r10_bio); | |
6bfe0b49 | 900 | retry_write: |
cb6969e8 | 901 | blocked_rdev = NULL; |
1da177e4 LT |
902 | rcu_read_lock(); |
903 | for (i = 0; i < conf->copies; i++) { | |
904 | int d = r10_bio->devs[i].devnum; | |
d6065f7b | 905 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev); |
6bfe0b49 DW |
906 | if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { |
907 | atomic_inc(&rdev->nr_pending); | |
908 | blocked_rdev = rdev; | |
909 | break; | |
910 | } | |
911 | if (rdev && !test_bit(Faulty, &rdev->flags)) { | |
d6065f7b | 912 | atomic_inc(&rdev->nr_pending); |
1da177e4 | 913 | r10_bio->devs[i].bio = bio; |
6cce3b23 | 914 | } else { |
1da177e4 | 915 | r10_bio->devs[i].bio = NULL; |
6cce3b23 N |
916 | set_bit(R10BIO_Degraded, &r10_bio->state); |
917 | } | |
1da177e4 LT |
918 | } |
919 | rcu_read_unlock(); | |
920 | ||
6bfe0b49 DW |
921 | if (unlikely(blocked_rdev)) { |
922 | /* Have to wait for this device to get unblocked, then retry */ | |
923 | int j; | |
924 | int d; | |
925 | ||
926 | for (j = 0; j < i; j++) | |
927 | if (r10_bio->devs[j].bio) { | |
928 | d = r10_bio->devs[j].devnum; | |
929 | rdev_dec_pending(conf->mirrors[d].rdev, mddev); | |
930 | } | |
931 | allow_barrier(conf); | |
932 | md_wait_for_blocked_rdev(blocked_rdev, mddev); | |
933 | wait_barrier(conf); | |
934 | goto retry_write; | |
935 | } | |
936 | ||
6cce3b23 | 937 | atomic_set(&r10_bio->remaining, 0); |
06d91a5f | 938 | |
6cce3b23 | 939 | bio_list_init(&bl); |
1da177e4 LT |
940 | for (i = 0; i < conf->copies; i++) { |
941 | struct bio *mbio; | |
942 | int d = r10_bio->devs[i].devnum; | |
943 | if (!r10_bio->devs[i].bio) | |
944 | continue; | |
945 | ||
946 | mbio = bio_clone(bio, GFP_NOIO); | |
947 | r10_bio->devs[i].bio = mbio; | |
948 | ||
949 | mbio->bi_sector = r10_bio->devs[i].addr+ | |
950 | conf->mirrors[d].rdev->data_offset; | |
951 | mbio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
952 | mbio->bi_end_io = raid10_end_write_request; | |
e3881a68 | 953 | mbio->bi_rw = WRITE | do_sync; |
1da177e4 LT |
954 | mbio->bi_private = r10_bio; |
955 | ||
956 | atomic_inc(&r10_bio->remaining); | |
6cce3b23 | 957 | bio_list_add(&bl, mbio); |
1da177e4 LT |
958 | } |
959 | ||
f6f953aa AR |
960 | if (unlikely(!atomic_read(&r10_bio->remaining))) { |
961 | /* the array is dead */ | |
962 | md_write_end(mddev); | |
963 | raid_end_bio_io(r10_bio); | |
964 | return 0; | |
965 | } | |
966 | ||
6cce3b23 N |
967 | bitmap_startwrite(mddev->bitmap, bio->bi_sector, r10_bio->sectors, 0); |
968 | spin_lock_irqsave(&conf->device_lock, flags); | |
969 | bio_list_merge(&conf->pending_bio_list, &bl); | |
970 | blk_plug_device(mddev->queue); | |
971 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1da177e4 | 972 | |
a35e63ef N |
973 | /* In case raid10d snuck in to freeze_array */ |
974 | wake_up(&conf->wait_barrier); | |
975 | ||
e3881a68 LE |
976 | if (do_sync) |
977 | md_wakeup_thread(mddev->thread); | |
978 | ||
1da177e4 LT |
979 | return 0; |
980 | } | |
981 | ||
982 | static void status(struct seq_file *seq, mddev_t *mddev) | |
983 | { | |
070ec55d | 984 | conf_t *conf = mddev->private; |
1da177e4 LT |
985 | int i; |
986 | ||
987 | if (conf->near_copies < conf->raid_disks) | |
9d8f0363 | 988 | seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2); |
1da177e4 LT |
989 | if (conf->near_copies > 1) |
990 | seq_printf(seq, " %d near-copies", conf->near_copies); | |
c93983bf N |
991 | if (conf->far_copies > 1) { |
992 | if (conf->far_offset) | |
993 | seq_printf(seq, " %d offset-copies", conf->far_copies); | |
994 | else | |
995 | seq_printf(seq, " %d far-copies", conf->far_copies); | |
996 | } | |
1da177e4 | 997 | seq_printf(seq, " [%d/%d] [", conf->raid_disks, |
76186dd8 | 998 | conf->raid_disks - mddev->degraded); |
1da177e4 LT |
999 | for (i = 0; i < conf->raid_disks; i++) |
1000 | seq_printf(seq, "%s", | |
1001 | conf->mirrors[i].rdev && | |
b2d444d7 | 1002 | test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
1003 | seq_printf(seq, "]"); |
1004 | } | |
1005 | ||
1006 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) | |
1007 | { | |
1008 | char b[BDEVNAME_SIZE]; | |
070ec55d | 1009 | conf_t *conf = mddev->private; |
1da177e4 LT |
1010 | |
1011 | /* | |
1012 | * If it is not operational, then we have already marked it as dead | |
1013 | * else if it is the last working disks, ignore the error, let the | |
1014 | * next level up know. | |
1015 | * else mark the drive as failed | |
1016 | */ | |
b2d444d7 | 1017 | if (test_bit(In_sync, &rdev->flags) |
76186dd8 | 1018 | && conf->raid_disks-mddev->degraded == 1) |
1da177e4 LT |
1019 | /* |
1020 | * Don't fail the drive, just return an IO error. | |
1021 | * The test should really be more sophisticated than | |
1022 | * "working_disks == 1", but it isn't critical, and | |
1023 | * can wait until we do more sophisticated "is the drive | |
1024 | * really dead" tests... | |
1025 | */ | |
1026 | return; | |
c04be0aa N |
1027 | if (test_and_clear_bit(In_sync, &rdev->flags)) { |
1028 | unsigned long flags; | |
1029 | spin_lock_irqsave(&conf->device_lock, flags); | |
1da177e4 | 1030 | mddev->degraded++; |
c04be0aa | 1031 | spin_unlock_irqrestore(&conf->device_lock, flags); |
1da177e4 LT |
1032 | /* |
1033 | * if recovery is running, make sure it aborts. | |
1034 | */ | |
dfc70645 | 1035 | set_bit(MD_RECOVERY_INTR, &mddev->recovery); |
1da177e4 | 1036 | } |
b2d444d7 | 1037 | set_bit(Faulty, &rdev->flags); |
850b2b42 | 1038 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
d7a420c9 NA |
1039 | printk(KERN_ALERT "raid10: Disk failure on %s, disabling device.\n" |
1040 | "raid10: Operation continuing on %d devices.\n", | |
76186dd8 | 1041 | bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded); |
1da177e4 LT |
1042 | } |
1043 | ||
1044 | static void print_conf(conf_t *conf) | |
1045 | { | |
1046 | int i; | |
1047 | mirror_info_t *tmp; | |
1048 | ||
1049 | printk("RAID10 conf printout:\n"); | |
1050 | if (!conf) { | |
1051 | printk("(!conf)\n"); | |
1052 | return; | |
1053 | } | |
76186dd8 | 1054 | printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded, |
1da177e4 LT |
1055 | conf->raid_disks); |
1056 | ||
1057 | for (i = 0; i < conf->raid_disks; i++) { | |
1058 | char b[BDEVNAME_SIZE]; | |
1059 | tmp = conf->mirrors + i; | |
1060 | if (tmp->rdev) | |
1061 | printk(" disk %d, wo:%d, o:%d, dev:%s\n", | |
b2d444d7 N |
1062 | i, !test_bit(In_sync, &tmp->rdev->flags), |
1063 | !test_bit(Faulty, &tmp->rdev->flags), | |
1da177e4 LT |
1064 | bdevname(tmp->rdev->bdev,b)); |
1065 | } | |
1066 | } | |
1067 | ||
1068 | static void close_sync(conf_t *conf) | |
1069 | { | |
0a27ec96 N |
1070 | wait_barrier(conf); |
1071 | allow_barrier(conf); | |
1da177e4 LT |
1072 | |
1073 | mempool_destroy(conf->r10buf_pool); | |
1074 | conf->r10buf_pool = NULL; | |
1075 | } | |
1076 | ||
6d508242 N |
1077 | /* check if there are enough drives for |
1078 | * every block to appear on atleast one | |
1079 | */ | |
1080 | static int enough(conf_t *conf) | |
1081 | { | |
1082 | int first = 0; | |
1083 | ||
1084 | do { | |
1085 | int n = conf->copies; | |
1086 | int cnt = 0; | |
1087 | while (n--) { | |
1088 | if (conf->mirrors[first].rdev) | |
1089 | cnt++; | |
1090 | first = (first+1) % conf->raid_disks; | |
1091 | } | |
1092 | if (cnt == 0) | |
1093 | return 0; | |
1094 | } while (first != 0); | |
1095 | return 1; | |
1096 | } | |
1097 | ||
1da177e4 LT |
1098 | static int raid10_spare_active(mddev_t *mddev) |
1099 | { | |
1100 | int i; | |
1101 | conf_t *conf = mddev->private; | |
1102 | mirror_info_t *tmp; | |
1103 | ||
1104 | /* | |
1105 | * Find all non-in_sync disks within the RAID10 configuration | |
1106 | * and mark them in_sync | |
1107 | */ | |
1108 | for (i = 0; i < conf->raid_disks; i++) { | |
1109 | tmp = conf->mirrors + i; | |
1110 | if (tmp->rdev | |
b2d444d7 | 1111 | && !test_bit(Faulty, &tmp->rdev->flags) |
c04be0aa N |
1112 | && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { |
1113 | unsigned long flags; | |
1114 | spin_lock_irqsave(&conf->device_lock, flags); | |
1da177e4 | 1115 | mddev->degraded--; |
c04be0aa | 1116 | spin_unlock_irqrestore(&conf->device_lock, flags); |
1da177e4 LT |
1117 | } |
1118 | } | |
1119 | ||
1120 | print_conf(conf); | |
1121 | return 0; | |
1122 | } | |
1123 | ||
1124 | ||
1125 | static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
1126 | { | |
1127 | conf_t *conf = mddev->private; | |
199050ea | 1128 | int err = -EEXIST; |
1da177e4 LT |
1129 | int mirror; |
1130 | mirror_info_t *p; | |
6c2fce2e NB |
1131 | int first = 0; |
1132 | int last = mddev->raid_disks - 1; | |
1da177e4 LT |
1133 | |
1134 | if (mddev->recovery_cp < MaxSector) | |
1135 | /* only hot-add to in-sync arrays, as recovery is | |
1136 | * very different from resync | |
1137 | */ | |
199050ea | 1138 | return -EBUSY; |
6d508242 | 1139 | if (!enough(conf)) |
199050ea | 1140 | return -EINVAL; |
1da177e4 | 1141 | |
a53a6c85 | 1142 | if (rdev->raid_disk >= 0) |
6c2fce2e | 1143 | first = last = rdev->raid_disk; |
1da177e4 | 1144 | |
6cce3b23 | 1145 | if (rdev->saved_raid_disk >= 0 && |
6c2fce2e | 1146 | rdev->saved_raid_disk >= first && |
6cce3b23 N |
1147 | conf->mirrors[rdev->saved_raid_disk].rdev == NULL) |
1148 | mirror = rdev->saved_raid_disk; | |
1149 | else | |
6c2fce2e NB |
1150 | mirror = first; |
1151 | for ( ; mirror <= last ; mirror++) | |
1da177e4 LT |
1152 | if ( !(p=conf->mirrors+mirror)->rdev) { |
1153 | ||
1154 | blk_queue_stack_limits(mddev->queue, | |
1155 | rdev->bdev->bd_disk->queue); | |
1156 | /* as we don't honour merge_bvec_fn, we must never risk | |
1157 | * violating it, so limit ->max_sector to one PAGE, as | |
1158 | * a one page request is never in violation. | |
1159 | */ | |
1160 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
ae03bf63 MP |
1161 | queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9)) |
1162 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); | |
1da177e4 LT |
1163 | |
1164 | p->head_position = 0; | |
1165 | rdev->raid_disk = mirror; | |
199050ea | 1166 | err = 0; |
6cce3b23 N |
1167 | if (rdev->saved_raid_disk != mirror) |
1168 | conf->fullsync = 1; | |
d6065f7b | 1169 | rcu_assign_pointer(p->rdev, rdev); |
1da177e4 LT |
1170 | break; |
1171 | } | |
1172 | ||
1173 | print_conf(conf); | |
199050ea | 1174 | return err; |
1da177e4 LT |
1175 | } |
1176 | ||
1177 | static int raid10_remove_disk(mddev_t *mddev, int number) | |
1178 | { | |
1179 | conf_t *conf = mddev->private; | |
1180 | int err = 0; | |
1181 | mdk_rdev_t *rdev; | |
1182 | mirror_info_t *p = conf->mirrors+ number; | |
1183 | ||
1184 | print_conf(conf); | |
1185 | rdev = p->rdev; | |
1186 | if (rdev) { | |
b2d444d7 | 1187 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 LT |
1188 | atomic_read(&rdev->nr_pending)) { |
1189 | err = -EBUSY; | |
1190 | goto abort; | |
1191 | } | |
dfc70645 N |
1192 | /* Only remove faulty devices in recovery |
1193 | * is not possible. | |
1194 | */ | |
1195 | if (!test_bit(Faulty, &rdev->flags) && | |
1196 | enough(conf)) { | |
1197 | err = -EBUSY; | |
1198 | goto abort; | |
1199 | } | |
1da177e4 | 1200 | p->rdev = NULL; |
fbd568a3 | 1201 | synchronize_rcu(); |
1da177e4 LT |
1202 | if (atomic_read(&rdev->nr_pending)) { |
1203 | /* lost the race, try later */ | |
1204 | err = -EBUSY; | |
1205 | p->rdev = rdev; | |
1206 | } | |
1207 | } | |
1208 | abort: | |
1209 | ||
1210 | print_conf(conf); | |
1211 | return err; | |
1212 | } | |
1213 | ||
1214 | ||
6712ecf8 | 1215 | static void end_sync_read(struct bio *bio, int error) |
1da177e4 | 1216 | { |
1da177e4 | 1217 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); |
070ec55d | 1218 | conf_t *conf = r10_bio->mddev->private; |
1da177e4 LT |
1219 | int i,d; |
1220 | ||
1da177e4 LT |
1221 | for (i=0; i<conf->copies; i++) |
1222 | if (r10_bio->devs[i].bio == bio) | |
1223 | break; | |
b6385483 | 1224 | BUG_ON(i == conf->copies); |
1da177e4 LT |
1225 | update_head_pos(i, r10_bio); |
1226 | d = r10_bio->devs[i].devnum; | |
0eb3ff12 N |
1227 | |
1228 | if (test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
1229 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
4dbcdc75 N |
1230 | else { |
1231 | atomic_add(r10_bio->sectors, | |
1232 | &conf->mirrors[d].rdev->corrected_errors); | |
1233 | if (!test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery)) | |
1234 | md_error(r10_bio->mddev, | |
1235 | conf->mirrors[d].rdev); | |
1236 | } | |
1da177e4 LT |
1237 | |
1238 | /* for reconstruct, we always reschedule after a read. | |
1239 | * for resync, only after all reads | |
1240 | */ | |
73d5c38a | 1241 | rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev); |
1da177e4 LT |
1242 | if (test_bit(R10BIO_IsRecover, &r10_bio->state) || |
1243 | atomic_dec_and_test(&r10_bio->remaining)) { | |
1244 | /* we have read all the blocks, | |
1245 | * do the comparison in process context in raid10d | |
1246 | */ | |
1247 | reschedule_retry(r10_bio); | |
1248 | } | |
1da177e4 LT |
1249 | } |
1250 | ||
6712ecf8 | 1251 | static void end_sync_write(struct bio *bio, int error) |
1da177e4 LT |
1252 | { |
1253 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
1254 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
1255 | mddev_t *mddev = r10_bio->mddev; | |
070ec55d | 1256 | conf_t *conf = mddev->private; |
1da177e4 LT |
1257 | int i,d; |
1258 | ||
1da177e4 LT |
1259 | for (i = 0; i < conf->copies; i++) |
1260 | if (r10_bio->devs[i].bio == bio) | |
1261 | break; | |
1262 | d = r10_bio->devs[i].devnum; | |
1263 | ||
1264 | if (!uptodate) | |
1265 | md_error(mddev, conf->mirrors[d].rdev); | |
dfc70645 | 1266 | |
1da177e4 LT |
1267 | update_head_pos(i, r10_bio); |
1268 | ||
73d5c38a | 1269 | rdev_dec_pending(conf->mirrors[d].rdev, mddev); |
1da177e4 LT |
1270 | while (atomic_dec_and_test(&r10_bio->remaining)) { |
1271 | if (r10_bio->master_bio == NULL) { | |
1272 | /* the primary of several recovery bios */ | |
73d5c38a | 1273 | sector_t s = r10_bio->sectors; |
1da177e4 | 1274 | put_buf(r10_bio); |
73d5c38a | 1275 | md_done_sync(mddev, s, 1); |
1da177e4 LT |
1276 | break; |
1277 | } else { | |
1278 | r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio; | |
1279 | put_buf(r10_bio); | |
1280 | r10_bio = r10_bio2; | |
1281 | } | |
1282 | } | |
1da177e4 LT |
1283 | } |
1284 | ||
1285 | /* | |
1286 | * Note: sync and recover and handled very differently for raid10 | |
1287 | * This code is for resync. | |
1288 | * For resync, we read through virtual addresses and read all blocks. | |
1289 | * If there is any error, we schedule a write. The lowest numbered | |
1290 | * drive is authoritative. | |
1291 | * However requests come for physical address, so we need to map. | |
1292 | * For every physical address there are raid_disks/copies virtual addresses, | |
1293 | * which is always are least one, but is not necessarly an integer. | |
1294 | * This means that a physical address can span multiple chunks, so we may | |
1295 | * have to submit multiple io requests for a single sync request. | |
1296 | */ | |
1297 | /* | |
1298 | * We check if all blocks are in-sync and only write to blocks that | |
1299 | * aren't in sync | |
1300 | */ | |
1301 | static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio) | |
1302 | { | |
070ec55d | 1303 | conf_t *conf = mddev->private; |
1da177e4 LT |
1304 | int i, first; |
1305 | struct bio *tbio, *fbio; | |
1306 | ||
1307 | atomic_set(&r10_bio->remaining, 1); | |
1308 | ||
1309 | /* find the first device with a block */ | |
1310 | for (i=0; i<conf->copies; i++) | |
1311 | if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) | |
1312 | break; | |
1313 | ||
1314 | if (i == conf->copies) | |
1315 | goto done; | |
1316 | ||
1317 | first = i; | |
1318 | fbio = r10_bio->devs[i].bio; | |
1319 | ||
1320 | /* now find blocks with errors */ | |
0eb3ff12 N |
1321 | for (i=0 ; i < conf->copies ; i++) { |
1322 | int j, d; | |
1323 | int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9); | |
1da177e4 | 1324 | |
1da177e4 | 1325 | tbio = r10_bio->devs[i].bio; |
0eb3ff12 N |
1326 | |
1327 | if (tbio->bi_end_io != end_sync_read) | |
1328 | continue; | |
1329 | if (i == first) | |
1da177e4 | 1330 | continue; |
0eb3ff12 N |
1331 | if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) { |
1332 | /* We know that the bi_io_vec layout is the same for | |
1333 | * both 'first' and 'i', so we just compare them. | |
1334 | * All vec entries are PAGE_SIZE; | |
1335 | */ | |
1336 | for (j = 0; j < vcnt; j++) | |
1337 | if (memcmp(page_address(fbio->bi_io_vec[j].bv_page), | |
1338 | page_address(tbio->bi_io_vec[j].bv_page), | |
1339 | PAGE_SIZE)) | |
1340 | break; | |
1341 | if (j == vcnt) | |
1342 | continue; | |
1343 | mddev->resync_mismatches += r10_bio->sectors; | |
1344 | } | |
18f08819 N |
1345 | if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) |
1346 | /* Don't fix anything. */ | |
1347 | continue; | |
1da177e4 LT |
1348 | /* Ok, we need to write this bio |
1349 | * First we need to fixup bv_offset, bv_len and | |
1350 | * bi_vecs, as the read request might have corrupted these | |
1351 | */ | |
1352 | tbio->bi_vcnt = vcnt; | |
1353 | tbio->bi_size = r10_bio->sectors << 9; | |
1354 | tbio->bi_idx = 0; | |
1355 | tbio->bi_phys_segments = 0; | |
1da177e4 LT |
1356 | tbio->bi_flags &= ~(BIO_POOL_MASK - 1); |
1357 | tbio->bi_flags |= 1 << BIO_UPTODATE; | |
1358 | tbio->bi_next = NULL; | |
1359 | tbio->bi_rw = WRITE; | |
1360 | tbio->bi_private = r10_bio; | |
1361 | tbio->bi_sector = r10_bio->devs[i].addr; | |
1362 | ||
1363 | for (j=0; j < vcnt ; j++) { | |
1364 | tbio->bi_io_vec[j].bv_offset = 0; | |
1365 | tbio->bi_io_vec[j].bv_len = PAGE_SIZE; | |
1366 | ||
1367 | memcpy(page_address(tbio->bi_io_vec[j].bv_page), | |
1368 | page_address(fbio->bi_io_vec[j].bv_page), | |
1369 | PAGE_SIZE); | |
1370 | } | |
1371 | tbio->bi_end_io = end_sync_write; | |
1372 | ||
1373 | d = r10_bio->devs[i].devnum; | |
1374 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1375 | atomic_inc(&r10_bio->remaining); | |
1376 | md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9); | |
1377 | ||
1378 | tbio->bi_sector += conf->mirrors[d].rdev->data_offset; | |
1379 | tbio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1380 | generic_make_request(tbio); | |
1381 | } | |
1382 | ||
1383 | done: | |
1384 | if (atomic_dec_and_test(&r10_bio->remaining)) { | |
1385 | md_done_sync(mddev, r10_bio->sectors, 1); | |
1386 | put_buf(r10_bio); | |
1387 | } | |
1388 | } | |
1389 | ||
1390 | /* | |
1391 | * Now for the recovery code. | |
1392 | * Recovery happens across physical sectors. | |
1393 | * We recover all non-is_sync drives by finding the virtual address of | |
1394 | * each, and then choose a working drive that also has that virt address. | |
1395 | * There is a separate r10_bio for each non-in_sync drive. | |
1396 | * Only the first two slots are in use. The first for reading, | |
1397 | * The second for writing. | |
1398 | * | |
1399 | */ | |
1400 | ||
1401 | static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio) | |
1402 | { | |
070ec55d | 1403 | conf_t *conf = mddev->private; |
1da177e4 LT |
1404 | int i, d; |
1405 | struct bio *bio, *wbio; | |
1406 | ||
1407 | ||
1408 | /* move the pages across to the second bio | |
1409 | * and submit the write request | |
1410 | */ | |
1411 | bio = r10_bio->devs[0].bio; | |
1412 | wbio = r10_bio->devs[1].bio; | |
1413 | for (i=0; i < wbio->bi_vcnt; i++) { | |
1414 | struct page *p = bio->bi_io_vec[i].bv_page; | |
1415 | bio->bi_io_vec[i].bv_page = wbio->bi_io_vec[i].bv_page; | |
1416 | wbio->bi_io_vec[i].bv_page = p; | |
1417 | } | |
1418 | d = r10_bio->devs[1].devnum; | |
1419 | ||
1420 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1421 | md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9); | |
0eb3ff12 N |
1422 | if (test_bit(R10BIO_Uptodate, &r10_bio->state)) |
1423 | generic_make_request(wbio); | |
1424 | else | |
6712ecf8 | 1425 | bio_endio(wbio, -EIO); |
1da177e4 LT |
1426 | } |
1427 | ||
1428 | ||
1429 | /* | |
1430 | * This is a kernel thread which: | |
1431 | * | |
1432 | * 1. Retries failed read operations on working mirrors. | |
1433 | * 2. Updates the raid superblock when problems encounter. | |
6814d536 | 1434 | * 3. Performs writes following reads for array synchronising. |
1da177e4 LT |
1435 | */ |
1436 | ||
6814d536 N |
1437 | static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio) |
1438 | { | |
1439 | int sect = 0; /* Offset from r10_bio->sector */ | |
1440 | int sectors = r10_bio->sectors; | |
1441 | mdk_rdev_t*rdev; | |
1442 | while(sectors) { | |
1443 | int s = sectors; | |
1444 | int sl = r10_bio->read_slot; | |
1445 | int success = 0; | |
1446 | int start; | |
1447 | ||
1448 | if (s > (PAGE_SIZE>>9)) | |
1449 | s = PAGE_SIZE >> 9; | |
1450 | ||
1451 | rcu_read_lock(); | |
1452 | do { | |
1453 | int d = r10_bio->devs[sl].devnum; | |
1454 | rdev = rcu_dereference(conf->mirrors[d].rdev); | |
1455 | if (rdev && | |
1456 | test_bit(In_sync, &rdev->flags)) { | |
1457 | atomic_inc(&rdev->nr_pending); | |
1458 | rcu_read_unlock(); | |
1459 | success = sync_page_io(rdev->bdev, | |
1460 | r10_bio->devs[sl].addr + | |
1461 | sect + rdev->data_offset, | |
1462 | s<<9, | |
1463 | conf->tmppage, READ); | |
1464 | rdev_dec_pending(rdev, mddev); | |
1465 | rcu_read_lock(); | |
1466 | if (success) | |
1467 | break; | |
1468 | } | |
1469 | sl++; | |
1470 | if (sl == conf->copies) | |
1471 | sl = 0; | |
1472 | } while (!success && sl != r10_bio->read_slot); | |
1473 | rcu_read_unlock(); | |
1474 | ||
1475 | if (!success) { | |
1476 | /* Cannot read from anywhere -- bye bye array */ | |
1477 | int dn = r10_bio->devs[r10_bio->read_slot].devnum; | |
1478 | md_error(mddev, conf->mirrors[dn].rdev); | |
1479 | break; | |
1480 | } | |
1481 | ||
1482 | start = sl; | |
1483 | /* write it back and re-read */ | |
1484 | rcu_read_lock(); | |
1485 | while (sl != r10_bio->read_slot) { | |
1486 | int d; | |
1487 | if (sl==0) | |
1488 | sl = conf->copies; | |
1489 | sl--; | |
1490 | d = r10_bio->devs[sl].devnum; | |
1491 | rdev = rcu_dereference(conf->mirrors[d].rdev); | |
1492 | if (rdev && | |
1493 | test_bit(In_sync, &rdev->flags)) { | |
1494 | atomic_inc(&rdev->nr_pending); | |
1495 | rcu_read_unlock(); | |
1496 | atomic_add(s, &rdev->corrected_errors); | |
1497 | if (sync_page_io(rdev->bdev, | |
1498 | r10_bio->devs[sl].addr + | |
1499 | sect + rdev->data_offset, | |
1500 | s<<9, conf->tmppage, WRITE) | |
1501 | == 0) | |
1502 | /* Well, this device is dead */ | |
1503 | md_error(mddev, rdev); | |
1504 | rdev_dec_pending(rdev, mddev); | |
1505 | rcu_read_lock(); | |
1506 | } | |
1507 | } | |
1508 | sl = start; | |
1509 | while (sl != r10_bio->read_slot) { | |
1510 | int d; | |
1511 | if (sl==0) | |
1512 | sl = conf->copies; | |
1513 | sl--; | |
1514 | d = r10_bio->devs[sl].devnum; | |
1515 | rdev = rcu_dereference(conf->mirrors[d].rdev); | |
1516 | if (rdev && | |
1517 | test_bit(In_sync, &rdev->flags)) { | |
1518 | char b[BDEVNAME_SIZE]; | |
1519 | atomic_inc(&rdev->nr_pending); | |
1520 | rcu_read_unlock(); | |
1521 | if (sync_page_io(rdev->bdev, | |
1522 | r10_bio->devs[sl].addr + | |
1523 | sect + rdev->data_offset, | |
1524 | s<<9, conf->tmppage, READ) == 0) | |
1525 | /* Well, this device is dead */ | |
1526 | md_error(mddev, rdev); | |
1527 | else | |
1528 | printk(KERN_INFO | |
1529 | "raid10:%s: read error corrected" | |
1530 | " (%d sectors at %llu on %s)\n", | |
1531 | mdname(mddev), s, | |
969b755a RD |
1532 | (unsigned long long)(sect+ |
1533 | rdev->data_offset), | |
6814d536 N |
1534 | bdevname(rdev->bdev, b)); |
1535 | ||
1536 | rdev_dec_pending(rdev, mddev); | |
1537 | rcu_read_lock(); | |
1538 | } | |
1539 | } | |
1540 | rcu_read_unlock(); | |
1541 | ||
1542 | sectors -= s; | |
1543 | sect += s; | |
1544 | } | |
1545 | } | |
1546 | ||
1da177e4 LT |
1547 | static void raid10d(mddev_t *mddev) |
1548 | { | |
1549 | r10bio_t *r10_bio; | |
1550 | struct bio *bio; | |
1551 | unsigned long flags; | |
070ec55d | 1552 | conf_t *conf = mddev->private; |
1da177e4 LT |
1553 | struct list_head *head = &conf->retry_list; |
1554 | int unplug=0; | |
1555 | mdk_rdev_t *rdev; | |
1556 | ||
1557 | md_check_recovery(mddev); | |
1da177e4 LT |
1558 | |
1559 | for (;;) { | |
1560 | char b[BDEVNAME_SIZE]; | |
6cce3b23 | 1561 | |
a35e63ef | 1562 | unplug += flush_pending_writes(conf); |
6cce3b23 | 1563 | |
a35e63ef N |
1564 | spin_lock_irqsave(&conf->device_lock, flags); |
1565 | if (list_empty(head)) { | |
1566 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1da177e4 | 1567 | break; |
a35e63ef | 1568 | } |
1da177e4 LT |
1569 | r10_bio = list_entry(head->prev, r10bio_t, retry_list); |
1570 | list_del(head->prev); | |
4443ae10 | 1571 | conf->nr_queued--; |
1da177e4 LT |
1572 | spin_unlock_irqrestore(&conf->device_lock, flags); |
1573 | ||
1574 | mddev = r10_bio->mddev; | |
070ec55d | 1575 | conf = mddev->private; |
1da177e4 LT |
1576 | if (test_bit(R10BIO_IsSync, &r10_bio->state)) { |
1577 | sync_request_write(mddev, r10_bio); | |
1578 | unplug = 1; | |
1579 | } else if (test_bit(R10BIO_IsRecover, &r10_bio->state)) { | |
1580 | recovery_request_write(mddev, r10_bio); | |
1581 | unplug = 1; | |
1582 | } else { | |
1583 | int mirror; | |
4443ae10 N |
1584 | /* we got a read error. Maybe the drive is bad. Maybe just |
1585 | * the block and we can fix it. | |
1586 | * We freeze all other IO, and try reading the block from | |
1587 | * other devices. When we find one, we re-write | |
1588 | * and check it that fixes the read error. | |
1589 | * This is all done synchronously while the array is | |
1590 | * frozen. | |
1591 | */ | |
6814d536 N |
1592 | if (mddev->ro == 0) { |
1593 | freeze_array(conf); | |
1594 | fix_read_error(conf, mddev, r10_bio); | |
1595 | unfreeze_array(conf); | |
4443ae10 N |
1596 | } |
1597 | ||
1da177e4 | 1598 | bio = r10_bio->devs[r10_bio->read_slot].bio; |
0eb3ff12 N |
1599 | r10_bio->devs[r10_bio->read_slot].bio = |
1600 | mddev->ro ? IO_BLOCKED : NULL; | |
1da177e4 LT |
1601 | mirror = read_balance(conf, r10_bio); |
1602 | if (mirror == -1) { | |
1603 | printk(KERN_ALERT "raid10: %s: unrecoverable I/O" | |
1604 | " read error for block %llu\n", | |
1605 | bdevname(bio->bi_bdev,b), | |
1606 | (unsigned long long)r10_bio->sector); | |
1607 | raid_end_bio_io(r10_bio); | |
14e71344 | 1608 | bio_put(bio); |
1da177e4 | 1609 | } else { |
e3881a68 | 1610 | const int do_sync = bio_sync(r10_bio->master_bio); |
14e71344 | 1611 | bio_put(bio); |
1da177e4 LT |
1612 | rdev = conf->mirrors[mirror].rdev; |
1613 | if (printk_ratelimit()) | |
1614 | printk(KERN_ERR "raid10: %s: redirecting sector %llu to" | |
1615 | " another mirror\n", | |
1616 | bdevname(rdev->bdev,b), | |
1617 | (unsigned long long)r10_bio->sector); | |
1618 | bio = bio_clone(r10_bio->master_bio, GFP_NOIO); | |
1619 | r10_bio->devs[r10_bio->read_slot].bio = bio; | |
1620 | bio->bi_sector = r10_bio->devs[r10_bio->read_slot].addr | |
1621 | + rdev->data_offset; | |
1622 | bio->bi_bdev = rdev->bdev; | |
e3881a68 | 1623 | bio->bi_rw = READ | do_sync; |
1da177e4 LT |
1624 | bio->bi_private = r10_bio; |
1625 | bio->bi_end_io = raid10_end_read_request; | |
1626 | unplug = 1; | |
1627 | generic_make_request(bio); | |
1628 | } | |
1629 | } | |
1630 | } | |
1da177e4 LT |
1631 | if (unplug) |
1632 | unplug_slaves(mddev); | |
1633 | } | |
1634 | ||
1635 | ||
1636 | static int init_resync(conf_t *conf) | |
1637 | { | |
1638 | int buffs; | |
1639 | ||
1640 | buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; | |
b6385483 | 1641 | BUG_ON(conf->r10buf_pool); |
1da177e4 LT |
1642 | conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf); |
1643 | if (!conf->r10buf_pool) | |
1644 | return -ENOMEM; | |
1645 | conf->next_resync = 0; | |
1646 | return 0; | |
1647 | } | |
1648 | ||
1649 | /* | |
1650 | * perform a "sync" on one "block" | |
1651 | * | |
1652 | * We need to make sure that no normal I/O request - particularly write | |
1653 | * requests - conflict with active sync requests. | |
1654 | * | |
1655 | * This is achieved by tracking pending requests and a 'barrier' concept | |
1656 | * that can be installed to exclude normal IO requests. | |
1657 | * | |
1658 | * Resync and recovery are handled very differently. | |
1659 | * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery. | |
1660 | * | |
1661 | * For resync, we iterate over virtual addresses, read all copies, | |
1662 | * and update if there are differences. If only one copy is live, | |
1663 | * skip it. | |
1664 | * For recovery, we iterate over physical addresses, read a good | |
1665 | * value for each non-in_sync drive, and over-write. | |
1666 | * | |
1667 | * So, for recovery we may have several outstanding complex requests for a | |
1668 | * given address, one for each out-of-sync device. We model this by allocating | |
1669 | * a number of r10_bio structures, one for each out-of-sync device. | |
1670 | * As we setup these structures, we collect all bio's together into a list | |
1671 | * which we then process collectively to add pages, and then process again | |
1672 | * to pass to generic_make_request. | |
1673 | * | |
1674 | * The r10_bio structures are linked using a borrowed master_bio pointer. | |
1675 | * This link is counted in ->remaining. When the r10_bio that points to NULL | |
1676 | * has its remaining count decremented to 0, the whole complex operation | |
1677 | * is complete. | |
1678 | * | |
1679 | */ | |
1680 | ||
57afd89f | 1681 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
1da177e4 | 1682 | { |
070ec55d | 1683 | conf_t *conf = mddev->private; |
1da177e4 LT |
1684 | r10bio_t *r10_bio; |
1685 | struct bio *biolist = NULL, *bio; | |
1686 | sector_t max_sector, nr_sectors; | |
1687 | int disk; | |
1688 | int i; | |
6cce3b23 N |
1689 | int max_sync; |
1690 | int sync_blocks; | |
1da177e4 LT |
1691 | |
1692 | sector_t sectors_skipped = 0; | |
1693 | int chunks_skipped = 0; | |
1694 | ||
1695 | if (!conf->r10buf_pool) | |
1696 | if (init_resync(conf)) | |
57afd89f | 1697 | return 0; |
1da177e4 LT |
1698 | |
1699 | skipped: | |
58c0fed4 | 1700 | max_sector = mddev->dev_sectors; |
1da177e4 LT |
1701 | if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) |
1702 | max_sector = mddev->resync_max_sectors; | |
1703 | if (sector_nr >= max_sector) { | |
6cce3b23 N |
1704 | /* If we aborted, we need to abort the |
1705 | * sync on the 'current' bitmap chucks (there can | |
1706 | * be several when recovering multiple devices). | |
1707 | * as we may have started syncing it but not finished. | |
1708 | * We can find the current address in | |
1709 | * mddev->curr_resync, but for recovery, | |
1710 | * we need to convert that to several | |
1711 | * virtual addresses. | |
1712 | */ | |
1713 | if (mddev->curr_resync < max_sector) { /* aborted */ | |
1714 | if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) | |
1715 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, | |
1716 | &sync_blocks, 1); | |
1717 | else for (i=0; i<conf->raid_disks; i++) { | |
1718 | sector_t sect = | |
1719 | raid10_find_virt(conf, mddev->curr_resync, i); | |
1720 | bitmap_end_sync(mddev->bitmap, sect, | |
1721 | &sync_blocks, 1); | |
1722 | } | |
1723 | } else /* completed sync */ | |
1724 | conf->fullsync = 0; | |
1725 | ||
1726 | bitmap_close_sync(mddev->bitmap); | |
1da177e4 | 1727 | close_sync(conf); |
57afd89f | 1728 | *skipped = 1; |
1da177e4 LT |
1729 | return sectors_skipped; |
1730 | } | |
1731 | if (chunks_skipped >= conf->raid_disks) { | |
1732 | /* if there has been nothing to do on any drive, | |
1733 | * then there is nothing to do at all.. | |
1734 | */ | |
57afd89f N |
1735 | *skipped = 1; |
1736 | return (max_sector - sector_nr) + sectors_skipped; | |
1da177e4 LT |
1737 | } |
1738 | ||
c6207277 N |
1739 | if (max_sector > mddev->resync_max) |
1740 | max_sector = mddev->resync_max; /* Don't do IO beyond here */ | |
1741 | ||
1da177e4 LT |
1742 | /* make sure whole request will fit in a chunk - if chunks |
1743 | * are meaningful | |
1744 | */ | |
1745 | if (conf->near_copies < conf->raid_disks && | |
1746 | max_sector > (sector_nr | conf->chunk_mask)) | |
1747 | max_sector = (sector_nr | conf->chunk_mask) + 1; | |
1748 | /* | |
1749 | * If there is non-resync activity waiting for us then | |
1750 | * put in a delay to throttle resync. | |
1751 | */ | |
0a27ec96 | 1752 | if (!go_faster && conf->nr_waiting) |
1da177e4 | 1753 | msleep_interruptible(1000); |
1da177e4 LT |
1754 | |
1755 | /* Again, very different code for resync and recovery. | |
1756 | * Both must result in an r10bio with a list of bios that | |
1757 | * have bi_end_io, bi_sector, bi_bdev set, | |
1758 | * and bi_private set to the r10bio. | |
1759 | * For recovery, we may actually create several r10bios | |
1760 | * with 2 bios in each, that correspond to the bios in the main one. | |
1761 | * In this case, the subordinate r10bios link back through a | |
1762 | * borrowed master_bio pointer, and the counter in the master | |
1763 | * includes a ref from each subordinate. | |
1764 | */ | |
1765 | /* First, we decide what to do and set ->bi_end_io | |
1766 | * To end_sync_read if we want to read, and | |
1767 | * end_sync_write if we will want to write. | |
1768 | */ | |
1769 | ||
6cce3b23 | 1770 | max_sync = RESYNC_PAGES << (PAGE_SHIFT-9); |
1da177e4 LT |
1771 | if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { |
1772 | /* recovery... the complicated one */ | |
1773 | int i, j, k; | |
1774 | r10_bio = NULL; | |
1775 | ||
1776 | for (i=0 ; i<conf->raid_disks; i++) | |
1777 | if (conf->mirrors[i].rdev && | |
b2d444d7 | 1778 | !test_bit(In_sync, &conf->mirrors[i].rdev->flags)) { |
6cce3b23 | 1779 | int still_degraded = 0; |
1da177e4 LT |
1780 | /* want to reconstruct this device */ |
1781 | r10bio_t *rb2 = r10_bio; | |
6cce3b23 N |
1782 | sector_t sect = raid10_find_virt(conf, sector_nr, i); |
1783 | int must_sync; | |
1784 | /* Unless we are doing a full sync, we only need | |
1785 | * to recover the block if it is set in the bitmap | |
1786 | */ | |
1787 | must_sync = bitmap_start_sync(mddev->bitmap, sect, | |
1788 | &sync_blocks, 1); | |
1789 | if (sync_blocks < max_sync) | |
1790 | max_sync = sync_blocks; | |
1791 | if (!must_sync && | |
1792 | !conf->fullsync) { | |
1793 | /* yep, skip the sync_blocks here, but don't assume | |
1794 | * that there will never be anything to do here | |
1795 | */ | |
1796 | chunks_skipped = -1; | |
1797 | continue; | |
1798 | } | |
1da177e4 LT |
1799 | |
1800 | r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO); | |
6cce3b23 | 1801 | raise_barrier(conf, rb2 != NULL); |
1da177e4 LT |
1802 | atomic_set(&r10_bio->remaining, 0); |
1803 | ||
1804 | r10_bio->master_bio = (struct bio*)rb2; | |
1805 | if (rb2) | |
1806 | atomic_inc(&rb2->remaining); | |
1807 | r10_bio->mddev = mddev; | |
1808 | set_bit(R10BIO_IsRecover, &r10_bio->state); | |
6cce3b23 N |
1809 | r10_bio->sector = sect; |
1810 | ||
1da177e4 | 1811 | raid10_find_phys(conf, r10_bio); |
18055569 N |
1812 | |
1813 | /* Need to check if the array will still be | |
6cce3b23 N |
1814 | * degraded |
1815 | */ | |
18055569 N |
1816 | for (j=0; j<conf->raid_disks; j++) |
1817 | if (conf->mirrors[j].rdev == NULL || | |
1818 | test_bit(Faulty, &conf->mirrors[j].rdev->flags)) { | |
6cce3b23 | 1819 | still_degraded = 1; |
a24a8dd8 N |
1820 | break; |
1821 | } | |
18055569 | 1822 | |
6cce3b23 N |
1823 | must_sync = bitmap_start_sync(mddev->bitmap, sect, |
1824 | &sync_blocks, still_degraded); | |
1825 | ||
1da177e4 LT |
1826 | for (j=0; j<conf->copies;j++) { |
1827 | int d = r10_bio->devs[j].devnum; | |
1828 | if (conf->mirrors[d].rdev && | |
b2d444d7 | 1829 | test_bit(In_sync, &conf->mirrors[d].rdev->flags)) { |
1da177e4 LT |
1830 | /* This is where we read from */ |
1831 | bio = r10_bio->devs[0].bio; | |
1832 | bio->bi_next = biolist; | |
1833 | biolist = bio; | |
1834 | bio->bi_private = r10_bio; | |
1835 | bio->bi_end_io = end_sync_read; | |
802ba064 | 1836 | bio->bi_rw = READ; |
1da177e4 LT |
1837 | bio->bi_sector = r10_bio->devs[j].addr + |
1838 | conf->mirrors[d].rdev->data_offset; | |
1839 | bio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1840 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1841 | atomic_inc(&r10_bio->remaining); | |
1842 | /* and we write to 'i' */ | |
1843 | ||
1844 | for (k=0; k<conf->copies; k++) | |
1845 | if (r10_bio->devs[k].devnum == i) | |
1846 | break; | |
64a742bc | 1847 | BUG_ON(k == conf->copies); |
1da177e4 LT |
1848 | bio = r10_bio->devs[1].bio; |
1849 | bio->bi_next = biolist; | |
1850 | biolist = bio; | |
1851 | bio->bi_private = r10_bio; | |
1852 | bio->bi_end_io = end_sync_write; | |
802ba064 | 1853 | bio->bi_rw = WRITE; |
1da177e4 LT |
1854 | bio->bi_sector = r10_bio->devs[k].addr + |
1855 | conf->mirrors[i].rdev->data_offset; | |
1856 | bio->bi_bdev = conf->mirrors[i].rdev->bdev; | |
1857 | ||
1858 | r10_bio->devs[0].devnum = d; | |
1859 | r10_bio->devs[1].devnum = i; | |
1860 | ||
1861 | break; | |
1862 | } | |
1863 | } | |
1864 | if (j == conf->copies) { | |
87fc767b N |
1865 | /* Cannot recover, so abort the recovery */ |
1866 | put_buf(r10_bio); | |
a07e6ab4 T |
1867 | if (rb2) |
1868 | atomic_dec(&rb2->remaining); | |
87fc767b | 1869 | r10_bio = rb2; |
dfc70645 N |
1870 | if (!test_and_set_bit(MD_RECOVERY_INTR, |
1871 | &mddev->recovery)) | |
87fc767b N |
1872 | printk(KERN_INFO "raid10: %s: insufficient working devices for recovery.\n", |
1873 | mdname(mddev)); | |
1874 | break; | |
1da177e4 LT |
1875 | } |
1876 | } | |
1877 | if (biolist == NULL) { | |
1878 | while (r10_bio) { | |
1879 | r10bio_t *rb2 = r10_bio; | |
1880 | r10_bio = (r10bio_t*) rb2->master_bio; | |
1881 | rb2->master_bio = NULL; | |
1882 | put_buf(rb2); | |
1883 | } | |
1884 | goto giveup; | |
1885 | } | |
1886 | } else { | |
1887 | /* resync. Schedule a read for every block at this virt offset */ | |
1888 | int count = 0; | |
6cce3b23 | 1889 | |
78200d45 N |
1890 | bitmap_cond_end_sync(mddev->bitmap, sector_nr); |
1891 | ||
6cce3b23 N |
1892 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, |
1893 | &sync_blocks, mddev->degraded) && | |
1894 | !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { | |
1895 | /* We can skip this block */ | |
1896 | *skipped = 1; | |
1897 | return sync_blocks + sectors_skipped; | |
1898 | } | |
1899 | if (sync_blocks < max_sync) | |
1900 | max_sync = sync_blocks; | |
1da177e4 LT |
1901 | r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO); |
1902 | ||
1da177e4 LT |
1903 | r10_bio->mddev = mddev; |
1904 | atomic_set(&r10_bio->remaining, 0); | |
6cce3b23 N |
1905 | raise_barrier(conf, 0); |
1906 | conf->next_resync = sector_nr; | |
1da177e4 LT |
1907 | |
1908 | r10_bio->master_bio = NULL; | |
1909 | r10_bio->sector = sector_nr; | |
1910 | set_bit(R10BIO_IsSync, &r10_bio->state); | |
1911 | raid10_find_phys(conf, r10_bio); | |
1912 | r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1; | |
1913 | ||
1914 | for (i=0; i<conf->copies; i++) { | |
1915 | int d = r10_bio->devs[i].devnum; | |
1916 | bio = r10_bio->devs[i].bio; | |
1917 | bio->bi_end_io = NULL; | |
af03b8e4 | 1918 | clear_bit(BIO_UPTODATE, &bio->bi_flags); |
1da177e4 | 1919 | if (conf->mirrors[d].rdev == NULL || |
b2d444d7 | 1920 | test_bit(Faulty, &conf->mirrors[d].rdev->flags)) |
1da177e4 LT |
1921 | continue; |
1922 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1923 | atomic_inc(&r10_bio->remaining); | |
1924 | bio->bi_next = biolist; | |
1925 | biolist = bio; | |
1926 | bio->bi_private = r10_bio; | |
1927 | bio->bi_end_io = end_sync_read; | |
802ba064 | 1928 | bio->bi_rw = READ; |
1da177e4 LT |
1929 | bio->bi_sector = r10_bio->devs[i].addr + |
1930 | conf->mirrors[d].rdev->data_offset; | |
1931 | bio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1932 | count++; | |
1933 | } | |
1934 | ||
1935 | if (count < 2) { | |
1936 | for (i=0; i<conf->copies; i++) { | |
1937 | int d = r10_bio->devs[i].devnum; | |
1938 | if (r10_bio->devs[i].bio->bi_end_io) | |
1939 | rdev_dec_pending(conf->mirrors[d].rdev, mddev); | |
1940 | } | |
1941 | put_buf(r10_bio); | |
1942 | biolist = NULL; | |
1943 | goto giveup; | |
1944 | } | |
1945 | } | |
1946 | ||
1947 | for (bio = biolist; bio ; bio=bio->bi_next) { | |
1948 | ||
1949 | bio->bi_flags &= ~(BIO_POOL_MASK - 1); | |
1950 | if (bio->bi_end_io) | |
1951 | bio->bi_flags |= 1 << BIO_UPTODATE; | |
1952 | bio->bi_vcnt = 0; | |
1953 | bio->bi_idx = 0; | |
1954 | bio->bi_phys_segments = 0; | |
1da177e4 LT |
1955 | bio->bi_size = 0; |
1956 | } | |
1957 | ||
1958 | nr_sectors = 0; | |
6cce3b23 N |
1959 | if (sector_nr + max_sync < max_sector) |
1960 | max_sector = sector_nr + max_sync; | |
1da177e4 LT |
1961 | do { |
1962 | struct page *page; | |
1963 | int len = PAGE_SIZE; | |
1964 | disk = 0; | |
1965 | if (sector_nr + (len>>9) > max_sector) | |
1966 | len = (max_sector - sector_nr) << 9; | |
1967 | if (len == 0) | |
1968 | break; | |
1969 | for (bio= biolist ; bio ; bio=bio->bi_next) { | |
1970 | page = bio->bi_io_vec[bio->bi_vcnt].bv_page; | |
1971 | if (bio_add_page(bio, page, len, 0) == 0) { | |
1972 | /* stop here */ | |
1973 | struct bio *bio2; | |
1974 | bio->bi_io_vec[bio->bi_vcnt].bv_page = page; | |
1975 | for (bio2 = biolist; bio2 && bio2 != bio; bio2 = bio2->bi_next) { | |
1976 | /* remove last page from this bio */ | |
1977 | bio2->bi_vcnt--; | |
1978 | bio2->bi_size -= len; | |
1979 | bio2->bi_flags &= ~(1<< BIO_SEG_VALID); | |
1980 | } | |
1981 | goto bio_full; | |
1982 | } | |
1983 | disk = i; | |
1984 | } | |
1985 | nr_sectors += len>>9; | |
1986 | sector_nr += len>>9; | |
1987 | } while (biolist->bi_vcnt < RESYNC_PAGES); | |
1988 | bio_full: | |
1989 | r10_bio->sectors = nr_sectors; | |
1990 | ||
1991 | while (biolist) { | |
1992 | bio = biolist; | |
1993 | biolist = biolist->bi_next; | |
1994 | ||
1995 | bio->bi_next = NULL; | |
1996 | r10_bio = bio->bi_private; | |
1997 | r10_bio->sectors = nr_sectors; | |
1998 | ||
1999 | if (bio->bi_end_io == end_sync_read) { | |
2000 | md_sync_acct(bio->bi_bdev, nr_sectors); | |
2001 | generic_make_request(bio); | |
2002 | } | |
2003 | } | |
2004 | ||
57afd89f N |
2005 | if (sectors_skipped) |
2006 | /* pretend they weren't skipped, it makes | |
2007 | * no important difference in this case | |
2008 | */ | |
2009 | md_done_sync(mddev, sectors_skipped, 1); | |
2010 | ||
1da177e4 LT |
2011 | return sectors_skipped + nr_sectors; |
2012 | giveup: | |
2013 | /* There is nowhere to write, so all non-sync | |
2014 | * drives must be failed, so try the next chunk... | |
2015 | */ | |
09b4068a N |
2016 | if (sector_nr + max_sync < max_sector) |
2017 | max_sector = sector_nr + max_sync; | |
2018 | ||
2019 | sectors_skipped += (max_sector - sector_nr); | |
1da177e4 LT |
2020 | chunks_skipped ++; |
2021 | sector_nr = max_sector; | |
1da177e4 | 2022 | goto skipped; |
1da177e4 LT |
2023 | } |
2024 | ||
80c3a6ce DW |
2025 | static sector_t |
2026 | raid10_size(mddev_t *mddev, sector_t sectors, int raid_disks) | |
2027 | { | |
2028 | sector_t size; | |
070ec55d | 2029 | conf_t *conf = mddev->private; |
80c3a6ce DW |
2030 | |
2031 | if (!raid_disks) | |
2032 | raid_disks = mddev->raid_disks; | |
2033 | if (!sectors) | |
2034 | sectors = mddev->dev_sectors; | |
2035 | ||
2036 | size = sectors >> conf->chunk_shift; | |
2037 | sector_div(size, conf->far_copies); | |
2038 | size = size * raid_disks; | |
2039 | sector_div(size, conf->near_copies); | |
2040 | ||
2041 | return size << conf->chunk_shift; | |
2042 | } | |
2043 | ||
1da177e4 LT |
2044 | static int run(mddev_t *mddev) |
2045 | { | |
2046 | conf_t *conf; | |
2047 | int i, disk_idx; | |
2048 | mirror_info_t *disk; | |
2049 | mdk_rdev_t *rdev; | |
c93983bf | 2050 | int nc, fc, fo; |
1da177e4 LT |
2051 | sector_t stride, size; |
2052 | ||
9d8f0363 AN |
2053 | if (mddev->chunk_sectors < (PAGE_SIZE >> 9) || |
2054 | !is_power_of_2(mddev->chunk_sectors)) { | |
4bbf3771 | 2055 | printk(KERN_ERR "md/raid10: chunk size must be " |
964e7913 | 2056 | "at least PAGE_SIZE(%ld) and be a power of 2.\n", PAGE_SIZE); |
2604b703 | 2057 | return -EINVAL; |
1da177e4 | 2058 | } |
2604b703 | 2059 | |
1da177e4 LT |
2060 | nc = mddev->layout & 255; |
2061 | fc = (mddev->layout >> 8) & 255; | |
c93983bf | 2062 | fo = mddev->layout & (1<<16); |
1da177e4 | 2063 | if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks || |
c93983bf | 2064 | (mddev->layout >> 17)) { |
1da177e4 LT |
2065 | printk(KERN_ERR "raid10: %s: unsupported raid10 layout: 0x%8x\n", |
2066 | mdname(mddev), mddev->layout); | |
2067 | goto out; | |
2068 | } | |
2069 | /* | |
2070 | * copy the already verified devices into our private RAID10 | |
2071 | * bookkeeping area. [whatever we allocate in run(), | |
2072 | * should be freed in stop()] | |
2073 | */ | |
4443ae10 | 2074 | conf = kzalloc(sizeof(conf_t), GFP_KERNEL); |
1da177e4 LT |
2075 | mddev->private = conf; |
2076 | if (!conf) { | |
2077 | printk(KERN_ERR "raid10: couldn't allocate memory for %s\n", | |
2078 | mdname(mddev)); | |
2079 | goto out; | |
2080 | } | |
4443ae10 | 2081 | conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks, |
1da177e4 LT |
2082 | GFP_KERNEL); |
2083 | if (!conf->mirrors) { | |
2084 | printk(KERN_ERR "raid10: couldn't allocate memory for %s\n", | |
2085 | mdname(mddev)); | |
2086 | goto out_free_conf; | |
2087 | } | |
4443ae10 N |
2088 | |
2089 | conf->tmppage = alloc_page(GFP_KERNEL); | |
2090 | if (!conf->tmppage) | |
2091 | goto out_free_conf; | |
1da177e4 | 2092 | |
64a742bc N |
2093 | conf->mddev = mddev; |
2094 | conf->raid_disks = mddev->raid_disks; | |
1da177e4 LT |
2095 | conf->near_copies = nc; |
2096 | conf->far_copies = fc; | |
2097 | conf->copies = nc*fc; | |
c93983bf | 2098 | conf->far_offset = fo; |
9d8f0363 AN |
2099 | conf->chunk_mask = mddev->chunk_sectors - 1; |
2100 | conf->chunk_shift = ffz(~mddev->chunk_sectors); | |
58c0fed4 | 2101 | size = mddev->dev_sectors >> conf->chunk_shift; |
64a742bc N |
2102 | sector_div(size, fc); |
2103 | size = size * conf->raid_disks; | |
2104 | sector_div(size, nc); | |
2105 | /* 'size' is now the number of chunks in the array */ | |
2106 | /* calculate "used chunks per device" in 'stride' */ | |
2107 | stride = size * conf->copies; | |
af03b8e4 N |
2108 | |
2109 | /* We need to round up when dividing by raid_disks to | |
2110 | * get the stride size. | |
2111 | */ | |
2112 | stride += conf->raid_disks - 1; | |
64a742bc | 2113 | sector_div(stride, conf->raid_disks); |
58c0fed4 | 2114 | mddev->dev_sectors = stride << conf->chunk_shift; |
64a742bc | 2115 | |
c93983bf | 2116 | if (fo) |
64a742bc N |
2117 | stride = 1; |
2118 | else | |
c93983bf | 2119 | sector_div(stride, fc); |
64a742bc N |
2120 | conf->stride = stride << conf->chunk_shift; |
2121 | ||
1da177e4 LT |
2122 | conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc, |
2123 | r10bio_pool_free, conf); | |
2124 | if (!conf->r10bio_pool) { | |
2125 | printk(KERN_ERR "raid10: couldn't allocate memory for %s\n", | |
2126 | mdname(mddev)); | |
2127 | goto out_free_conf; | |
2128 | } | |
1da177e4 | 2129 | |
e7e72bf6 NB |
2130 | spin_lock_init(&conf->device_lock); |
2131 | mddev->queue->queue_lock = &conf->device_lock; | |
2132 | ||
159ec1fc | 2133 | list_for_each_entry(rdev, &mddev->disks, same_set) { |
1da177e4 LT |
2134 | disk_idx = rdev->raid_disk; |
2135 | if (disk_idx >= mddev->raid_disks | |
2136 | || disk_idx < 0) | |
2137 | continue; | |
2138 | disk = conf->mirrors + disk_idx; | |
2139 | ||
2140 | disk->rdev = rdev; | |
2141 | ||
2142 | blk_queue_stack_limits(mddev->queue, | |
2143 | rdev->bdev->bd_disk->queue); | |
2144 | /* as we don't honour merge_bvec_fn, we must never risk | |
2145 | * violating it, so limit ->max_sector to one PAGE, as | |
2146 | * a one page request is never in violation. | |
2147 | */ | |
2148 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
ae03bf63 MP |
2149 | queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9)) |
2150 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); | |
1da177e4 LT |
2151 | |
2152 | disk->head_position = 0; | |
1da177e4 | 2153 | } |
1da177e4 LT |
2154 | INIT_LIST_HEAD(&conf->retry_list); |
2155 | ||
2156 | spin_lock_init(&conf->resync_lock); | |
0a27ec96 | 2157 | init_waitqueue_head(&conf->wait_barrier); |
1da177e4 | 2158 | |
6d508242 N |
2159 | /* need to check that every block has at least one working mirror */ |
2160 | if (!enough(conf)) { | |
2161 | printk(KERN_ERR "raid10: not enough operational mirrors for %s\n", | |
2162 | mdname(mddev)); | |
1da177e4 LT |
2163 | goto out_free_conf; |
2164 | } | |
2165 | ||
2166 | mddev->degraded = 0; | |
2167 | for (i = 0; i < conf->raid_disks; i++) { | |
2168 | ||
2169 | disk = conf->mirrors + i; | |
2170 | ||
5fd6c1dc | 2171 | if (!disk->rdev || |
2e333e89 | 2172 | !test_bit(In_sync, &disk->rdev->flags)) { |
1da177e4 LT |
2173 | disk->head_position = 0; |
2174 | mddev->degraded++; | |
8c2e870a NB |
2175 | if (disk->rdev) |
2176 | conf->fullsync = 1; | |
1da177e4 LT |
2177 | } |
2178 | } | |
2179 | ||
2180 | ||
2181 | mddev->thread = md_register_thread(raid10d, mddev, "%s_raid10"); | |
2182 | if (!mddev->thread) { | |
2183 | printk(KERN_ERR | |
2184 | "raid10: couldn't allocate thread for %s\n", | |
2185 | mdname(mddev)); | |
2186 | goto out_free_conf; | |
2187 | } | |
2188 | ||
8c6ac868 AN |
2189 | if (mddev->recovery_cp != MaxSector) |
2190 | printk(KERN_NOTICE "raid10: %s is not clean" | |
2191 | " -- starting background reconstruction\n", | |
2192 | mdname(mddev)); | |
1da177e4 LT |
2193 | printk(KERN_INFO |
2194 | "raid10: raid set %s active with %d out of %d devices\n", | |
2195 | mdname(mddev), mddev->raid_disks - mddev->degraded, | |
2196 | mddev->raid_disks); | |
2197 | /* | |
2198 | * Ok, everything is just fine now | |
2199 | */ | |
1f403624 | 2200 | md_set_array_sectors(mddev, raid10_size(mddev, 0, 0)); |
b522adcd | 2201 | mddev->resync_max_sectors = raid10_size(mddev, 0, 0); |
1da177e4 | 2202 | |
7a5febe9 | 2203 | mddev->queue->unplug_fn = raid10_unplug; |
0d129228 N |
2204 | mddev->queue->backing_dev_info.congested_fn = raid10_congested; |
2205 | mddev->queue->backing_dev_info.congested_data = mddev; | |
7a5febe9 | 2206 | |
1da177e4 LT |
2207 | /* Calculate max read-ahead size. |
2208 | * We need to readahead at least twice a whole stripe.... | |
2209 | * maybe... | |
2210 | */ | |
2211 | { | |
9d8f0363 AN |
2212 | int stripe = conf->raid_disks * |
2213 | ((mddev->chunk_sectors << 9) / PAGE_SIZE); | |
1da177e4 LT |
2214 | stripe /= conf->near_copies; |
2215 | if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) | |
2216 | mddev->queue->backing_dev_info.ra_pages = 2* stripe; | |
2217 | } | |
2218 | ||
2219 | if (conf->near_copies < mddev->raid_disks) | |
2220 | blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec); | |
2221 | return 0; | |
2222 | ||
2223 | out_free_conf: | |
2224 | if (conf->r10bio_pool) | |
2225 | mempool_destroy(conf->r10bio_pool); | |
1345b1d8 | 2226 | safe_put_page(conf->tmppage); |
990a8baf | 2227 | kfree(conf->mirrors); |
1da177e4 LT |
2228 | kfree(conf); |
2229 | mddev->private = NULL; | |
2230 | out: | |
2231 | return -EIO; | |
2232 | } | |
2233 | ||
2234 | static int stop(mddev_t *mddev) | |
2235 | { | |
070ec55d | 2236 | conf_t *conf = mddev->private; |
1da177e4 | 2237 | |
409c57f3 N |
2238 | raise_barrier(conf, 0); |
2239 | lower_barrier(conf); | |
2240 | ||
1da177e4 LT |
2241 | md_unregister_thread(mddev->thread); |
2242 | mddev->thread = NULL; | |
2243 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
2244 | if (conf->r10bio_pool) | |
2245 | mempool_destroy(conf->r10bio_pool); | |
990a8baf | 2246 | kfree(conf->mirrors); |
1da177e4 LT |
2247 | kfree(conf); |
2248 | mddev->private = NULL; | |
2249 | return 0; | |
2250 | } | |
2251 | ||
6cce3b23 N |
2252 | static void raid10_quiesce(mddev_t *mddev, int state) |
2253 | { | |
070ec55d | 2254 | conf_t *conf = mddev->private; |
6cce3b23 N |
2255 | |
2256 | switch(state) { | |
2257 | case 1: | |
2258 | raise_barrier(conf, 0); | |
2259 | break; | |
2260 | case 0: | |
2261 | lower_barrier(conf); | |
2262 | break; | |
2263 | } | |
2264 | if (mddev->thread) { | |
2265 | if (mddev->bitmap) | |
2266 | mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ; | |
2267 | else | |
2268 | mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT; | |
2269 | md_wakeup_thread(mddev->thread); | |
2270 | } | |
2271 | } | |
1da177e4 | 2272 | |
2604b703 | 2273 | static struct mdk_personality raid10_personality = |
1da177e4 LT |
2274 | { |
2275 | .name = "raid10", | |
2604b703 | 2276 | .level = 10, |
1da177e4 LT |
2277 | .owner = THIS_MODULE, |
2278 | .make_request = make_request, | |
2279 | .run = run, | |
2280 | .stop = stop, | |
2281 | .status = status, | |
2282 | .error_handler = error, | |
2283 | .hot_add_disk = raid10_add_disk, | |
2284 | .hot_remove_disk= raid10_remove_disk, | |
2285 | .spare_active = raid10_spare_active, | |
2286 | .sync_request = sync_request, | |
6cce3b23 | 2287 | .quiesce = raid10_quiesce, |
80c3a6ce | 2288 | .size = raid10_size, |
1da177e4 LT |
2289 | }; |
2290 | ||
2291 | static int __init raid_init(void) | |
2292 | { | |
2604b703 | 2293 | return register_md_personality(&raid10_personality); |
1da177e4 LT |
2294 | } |
2295 | ||
2296 | static void raid_exit(void) | |
2297 | { | |
2604b703 | 2298 | unregister_md_personality(&raid10_personality); |
1da177e4 LT |
2299 | } |
2300 | ||
2301 | module_init(raid_init); | |
2302 | module_exit(raid_exit); | |
2303 | MODULE_LICENSE("GPL"); | |
2304 | MODULE_ALIAS("md-personality-9"); /* RAID10 */ | |
d9d166c2 | 2305 | MODULE_ALIAS("md-raid10"); |
2604b703 | 2306 | MODULE_ALIAS("md-level-10"); |