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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 | ||
21 | #include <linux/raid/raid10.h> | |
22 | ||
23 | /* | |
24 | * RAID10 provides a combination of RAID0 and RAID1 functionality. | |
25 | * The layout of data is defined by | |
26 | * chunk_size | |
27 | * raid_disks | |
28 | * near_copies (stored in low byte of layout) | |
29 | * far_copies (stored in second byte of layout) | |
30 | * | |
31 | * The data to be stored is divided into chunks using chunksize. | |
32 | * Each device is divided into far_copies sections. | |
33 | * In each section, chunks are laid out in a style similar to raid0, but | |
34 | * near_copies copies of each chunk is stored (each on a different drive). | |
35 | * The starting device for each section is offset near_copies from the starting | |
36 | * device of the previous section. | |
37 | * Thus there are (near_copies*far_copies) of each chunk, and each is on a different | |
38 | * drive. | |
39 | * near_copies and far_copies must be at least one, and their product is at most | |
40 | * raid_disks. | |
41 | */ | |
42 | ||
43 | /* | |
44 | * Number of guaranteed r10bios in case of extreme VM load: | |
45 | */ | |
46 | #define NR_RAID10_BIOS 256 | |
47 | ||
48 | static void unplug_slaves(mddev_t *mddev); | |
49 | ||
0a27ec96 N |
50 | static void allow_barrier(conf_t *conf); |
51 | static void lower_barrier(conf_t *conf); | |
52 | ||
dd0fc66f | 53 | static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
54 | { |
55 | conf_t *conf = data; | |
56 | r10bio_t *r10_bio; | |
57 | int size = offsetof(struct r10bio_s, devs[conf->copies]); | |
58 | ||
59 | /* allocate a r10bio with room for raid_disks entries in the bios array */ | |
60 | r10_bio = kmalloc(size, gfp_flags); | |
61 | if (r10_bio) | |
62 | memset(r10_bio, 0, size); | |
63 | else | |
64 | unplug_slaves(conf->mddev); | |
65 | ||
66 | return r10_bio; | |
67 | } | |
68 | ||
69 | static void r10bio_pool_free(void *r10_bio, void *data) | |
70 | { | |
71 | kfree(r10_bio); | |
72 | } | |
73 | ||
74 | #define RESYNC_BLOCK_SIZE (64*1024) | |
75 | //#define RESYNC_BLOCK_SIZE PAGE_SIZE | |
76 | #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) | |
77 | #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) | |
78 | #define RESYNC_WINDOW (2048*1024) | |
79 | ||
80 | /* | |
81 | * When performing a resync, we need to read and compare, so | |
82 | * we need as many pages are there are copies. | |
83 | * When performing a recovery, we need 2 bios, one for read, | |
84 | * one for write (we recover only one drive per r10buf) | |
85 | * | |
86 | */ | |
dd0fc66f | 87 | static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
88 | { |
89 | conf_t *conf = data; | |
90 | struct page *page; | |
91 | r10bio_t *r10_bio; | |
92 | struct bio *bio; | |
93 | int i, j; | |
94 | int nalloc; | |
95 | ||
96 | r10_bio = r10bio_pool_alloc(gfp_flags, conf); | |
97 | if (!r10_bio) { | |
98 | unplug_slaves(conf->mddev); | |
99 | return NULL; | |
100 | } | |
101 | ||
102 | if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery)) | |
103 | nalloc = conf->copies; /* resync */ | |
104 | else | |
105 | nalloc = 2; /* recovery */ | |
106 | ||
107 | /* | |
108 | * Allocate bios. | |
109 | */ | |
110 | for (j = nalloc ; j-- ; ) { | |
111 | bio = bio_alloc(gfp_flags, RESYNC_PAGES); | |
112 | if (!bio) | |
113 | goto out_free_bio; | |
114 | r10_bio->devs[j].bio = bio; | |
115 | } | |
116 | /* | |
117 | * Allocate RESYNC_PAGES data pages and attach them | |
118 | * where needed. | |
119 | */ | |
120 | for (j = 0 ; j < nalloc; j++) { | |
121 | bio = r10_bio->devs[j].bio; | |
122 | for (i = 0; i < RESYNC_PAGES; i++) { | |
123 | page = alloc_page(gfp_flags); | |
124 | if (unlikely(!page)) | |
125 | goto out_free_pages; | |
126 | ||
127 | bio->bi_io_vec[i].bv_page = page; | |
128 | } | |
129 | } | |
130 | ||
131 | return r10_bio; | |
132 | ||
133 | out_free_pages: | |
134 | for ( ; i > 0 ; i--) | |
135 | __free_page(bio->bi_io_vec[i-1].bv_page); | |
136 | while (j--) | |
137 | for (i = 0; i < RESYNC_PAGES ; i++) | |
138 | __free_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page); | |
139 | j = -1; | |
140 | out_free_bio: | |
141 | while ( ++j < nalloc ) | |
142 | bio_put(r10_bio->devs[j].bio); | |
143 | r10bio_pool_free(r10_bio, conf); | |
144 | return NULL; | |
145 | } | |
146 | ||
147 | static void r10buf_pool_free(void *__r10_bio, void *data) | |
148 | { | |
149 | int i; | |
150 | conf_t *conf = data; | |
151 | r10bio_t *r10bio = __r10_bio; | |
152 | int j; | |
153 | ||
154 | for (j=0; j < conf->copies; j++) { | |
155 | struct bio *bio = r10bio->devs[j].bio; | |
156 | if (bio) { | |
157 | for (i = 0; i < RESYNC_PAGES; i++) { | |
158 | __free_page(bio->bi_io_vec[i].bv_page); | |
159 | bio->bi_io_vec[i].bv_page = NULL; | |
160 | } | |
161 | bio_put(bio); | |
162 | } | |
163 | } | |
164 | r10bio_pool_free(r10bio, conf); | |
165 | } | |
166 | ||
167 | static void put_all_bios(conf_t *conf, r10bio_t *r10_bio) | |
168 | { | |
169 | int i; | |
170 | ||
171 | for (i = 0; i < conf->copies; i++) { | |
172 | struct bio **bio = & r10_bio->devs[i].bio; | |
173 | if (*bio) | |
174 | bio_put(*bio); | |
175 | *bio = NULL; | |
176 | } | |
177 | } | |
178 | ||
179 | static inline void free_r10bio(r10bio_t *r10_bio) | |
180 | { | |
1da177e4 LT |
181 | conf_t *conf = mddev_to_conf(r10_bio->mddev); |
182 | ||
183 | /* | |
184 | * Wake up any possible resync thread that waits for the device | |
185 | * to go idle. | |
186 | */ | |
0a27ec96 | 187 | allow_barrier(conf); |
1da177e4 LT |
188 | |
189 | put_all_bios(conf, r10_bio); | |
190 | mempool_free(r10_bio, conf->r10bio_pool); | |
191 | } | |
192 | ||
193 | static inline void put_buf(r10bio_t *r10_bio) | |
194 | { | |
195 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
1da177e4 LT |
196 | |
197 | mempool_free(r10_bio, conf->r10buf_pool); | |
198 | ||
0a27ec96 | 199 | lower_barrier(conf); |
1da177e4 LT |
200 | } |
201 | ||
202 | static void reschedule_retry(r10bio_t *r10_bio) | |
203 | { | |
204 | unsigned long flags; | |
205 | mddev_t *mddev = r10_bio->mddev; | |
206 | conf_t *conf = mddev_to_conf(mddev); | |
207 | ||
208 | spin_lock_irqsave(&conf->device_lock, flags); | |
209 | list_add(&r10_bio->retry_list, &conf->retry_list); | |
210 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
211 | ||
212 | md_wakeup_thread(mddev->thread); | |
213 | } | |
214 | ||
215 | /* | |
216 | * raid_end_bio_io() is called when we have finished servicing a mirrored | |
217 | * operation and are ready to return a success/failure code to the buffer | |
218 | * cache layer. | |
219 | */ | |
220 | static void raid_end_bio_io(r10bio_t *r10_bio) | |
221 | { | |
222 | struct bio *bio = r10_bio->master_bio; | |
223 | ||
224 | bio_endio(bio, bio->bi_size, | |
225 | test_bit(R10BIO_Uptodate, &r10_bio->state) ? 0 : -EIO); | |
226 | free_r10bio(r10_bio); | |
227 | } | |
228 | ||
229 | /* | |
230 | * Update disk head position estimator based on IRQ completion info. | |
231 | */ | |
232 | static inline void update_head_pos(int slot, r10bio_t *r10_bio) | |
233 | { | |
234 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
235 | ||
236 | conf->mirrors[r10_bio->devs[slot].devnum].head_position = | |
237 | r10_bio->devs[slot].addr + (r10_bio->sectors); | |
238 | } | |
239 | ||
240 | static int raid10_end_read_request(struct bio *bio, unsigned int bytes_done, int error) | |
241 | { | |
242 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
243 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
244 | int slot, dev; | |
245 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
246 | ||
247 | if (bio->bi_size) | |
248 | return 1; | |
249 | ||
250 | slot = r10_bio->read_slot; | |
251 | dev = r10_bio->devs[slot].devnum; | |
252 | /* | |
253 | * this branch is our 'one mirror IO has finished' event handler: | |
254 | */ | |
255 | if (!uptodate) | |
256 | md_error(r10_bio->mddev, conf->mirrors[dev].rdev); | |
257 | else | |
258 | /* | |
259 | * Set R10BIO_Uptodate in our master bio, so that | |
260 | * we will return a good error code to the higher | |
261 | * levels even if IO on some other mirrored buffer fails. | |
262 | * | |
263 | * The 'master' represents the composite IO operation to | |
264 | * user-side. So if something waits for IO, then it will | |
265 | * wait for the 'master' bio. | |
266 | */ | |
267 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
268 | ||
269 | update_head_pos(slot, r10_bio); | |
270 | ||
271 | /* | |
272 | * we have only one bio on the read side | |
273 | */ | |
274 | if (uptodate) | |
275 | raid_end_bio_io(r10_bio); | |
276 | else { | |
277 | /* | |
278 | * oops, read error: | |
279 | */ | |
280 | char b[BDEVNAME_SIZE]; | |
281 | if (printk_ratelimit()) | |
282 | printk(KERN_ERR "raid10: %s: rescheduling sector %llu\n", | |
283 | bdevname(conf->mirrors[dev].rdev->bdev,b), (unsigned long long)r10_bio->sector); | |
284 | reschedule_retry(r10_bio); | |
285 | } | |
286 | ||
287 | rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev); | |
288 | return 0; | |
289 | } | |
290 | ||
291 | static int raid10_end_write_request(struct bio *bio, unsigned int bytes_done, int error) | |
292 | { | |
293 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
294 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
295 | int slot, dev; | |
296 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
297 | ||
298 | if (bio->bi_size) | |
299 | return 1; | |
300 | ||
301 | for (slot = 0; slot < conf->copies; slot++) | |
302 | if (r10_bio->devs[slot].bio == bio) | |
303 | break; | |
304 | dev = r10_bio->devs[slot].devnum; | |
305 | ||
306 | /* | |
307 | * this branch is our 'one mirror IO has finished' event handler: | |
308 | */ | |
309 | if (!uptodate) | |
310 | md_error(r10_bio->mddev, conf->mirrors[dev].rdev); | |
311 | else | |
312 | /* | |
313 | * Set R10BIO_Uptodate in our master bio, so that | |
314 | * we will return a good error code for to the higher | |
315 | * levels even if IO on some other mirrored buffer fails. | |
316 | * | |
317 | * The 'master' represents the composite IO operation to | |
318 | * user-side. So if something waits for IO, then it will | |
319 | * wait for the 'master' bio. | |
320 | */ | |
321 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
322 | ||
323 | update_head_pos(slot, r10_bio); | |
324 | ||
325 | /* | |
326 | * | |
327 | * Let's see if all mirrored write operations have finished | |
328 | * already. | |
329 | */ | |
330 | if (atomic_dec_and_test(&r10_bio->remaining)) { | |
331 | md_write_end(r10_bio->mddev); | |
332 | raid_end_bio_io(r10_bio); | |
333 | } | |
334 | ||
335 | rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev); | |
336 | return 0; | |
337 | } | |
338 | ||
339 | ||
340 | /* | |
341 | * RAID10 layout manager | |
342 | * Aswell as the chunksize and raid_disks count, there are two | |
343 | * parameters: near_copies and far_copies. | |
344 | * near_copies * far_copies must be <= raid_disks. | |
345 | * Normally one of these will be 1. | |
346 | * If both are 1, we get raid0. | |
347 | * If near_copies == raid_disks, we get raid1. | |
348 | * | |
349 | * Chunks are layed out in raid0 style with near_copies copies of the | |
350 | * first chunk, followed by near_copies copies of the next chunk and | |
351 | * so on. | |
352 | * If far_copies > 1, then after 1/far_copies of the array has been assigned | |
353 | * as described above, we start again with a device offset of near_copies. | |
354 | * So we effectively have another copy of the whole array further down all | |
355 | * the drives, but with blocks on different drives. | |
356 | * With this layout, and block is never stored twice on the one device. | |
357 | * | |
358 | * raid10_find_phys finds the sector offset of a given virtual sector | |
359 | * on each device that it is on. If a block isn't on a device, | |
360 | * that entry in the array is set to MaxSector. | |
361 | * | |
362 | * raid10_find_virt does the reverse mapping, from a device and a | |
363 | * sector offset to a virtual address | |
364 | */ | |
365 | ||
366 | static void raid10_find_phys(conf_t *conf, r10bio_t *r10bio) | |
367 | { | |
368 | int n,f; | |
369 | sector_t sector; | |
370 | sector_t chunk; | |
371 | sector_t stripe; | |
372 | int dev; | |
373 | ||
374 | int slot = 0; | |
375 | ||
376 | /* now calculate first sector/dev */ | |
377 | chunk = r10bio->sector >> conf->chunk_shift; | |
378 | sector = r10bio->sector & conf->chunk_mask; | |
379 | ||
380 | chunk *= conf->near_copies; | |
381 | stripe = chunk; | |
382 | dev = sector_div(stripe, conf->raid_disks); | |
383 | ||
384 | sector += stripe << conf->chunk_shift; | |
385 | ||
386 | /* and calculate all the others */ | |
387 | for (n=0; n < conf->near_copies; n++) { | |
388 | int d = dev; | |
389 | sector_t s = sector; | |
390 | r10bio->devs[slot].addr = sector; | |
391 | r10bio->devs[slot].devnum = d; | |
392 | slot++; | |
393 | ||
394 | for (f = 1; f < conf->far_copies; f++) { | |
395 | d += conf->near_copies; | |
396 | if (d >= conf->raid_disks) | |
397 | d -= conf->raid_disks; | |
398 | s += conf->stride; | |
399 | r10bio->devs[slot].devnum = d; | |
400 | r10bio->devs[slot].addr = s; | |
401 | slot++; | |
402 | } | |
403 | dev++; | |
404 | if (dev >= conf->raid_disks) { | |
405 | dev = 0; | |
406 | sector += (conf->chunk_mask + 1); | |
407 | } | |
408 | } | |
409 | BUG_ON(slot != conf->copies); | |
410 | } | |
411 | ||
412 | static sector_t raid10_find_virt(conf_t *conf, sector_t sector, int dev) | |
413 | { | |
414 | sector_t offset, chunk, vchunk; | |
415 | ||
416 | while (sector > conf->stride) { | |
417 | sector -= conf->stride; | |
418 | if (dev < conf->near_copies) | |
419 | dev += conf->raid_disks - conf->near_copies; | |
420 | else | |
421 | dev -= conf->near_copies; | |
422 | } | |
423 | ||
424 | offset = sector & conf->chunk_mask; | |
425 | chunk = sector >> conf->chunk_shift; | |
426 | vchunk = chunk * conf->raid_disks + dev; | |
427 | sector_div(vchunk, conf->near_copies); | |
428 | return (vchunk << conf->chunk_shift) + offset; | |
429 | } | |
430 | ||
431 | /** | |
432 | * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged | |
433 | * @q: request queue | |
434 | * @bio: the buffer head that's been built up so far | |
435 | * @biovec: the request that could be merged to it. | |
436 | * | |
437 | * Return amount of bytes we can accept at this offset | |
438 | * If near_copies == raid_disk, there are no striping issues, | |
439 | * but in that case, the function isn't called at all. | |
440 | */ | |
441 | static int raid10_mergeable_bvec(request_queue_t *q, struct bio *bio, | |
442 | struct bio_vec *bio_vec) | |
443 | { | |
444 | mddev_t *mddev = q->queuedata; | |
445 | sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); | |
446 | int max; | |
447 | unsigned int chunk_sectors = mddev->chunk_size >> 9; | |
448 | unsigned int bio_sectors = bio->bi_size >> 9; | |
449 | ||
450 | max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; | |
451 | if (max < 0) max = 0; /* bio_add cannot handle a negative return */ | |
452 | if (max <= bio_vec->bv_len && bio_sectors == 0) | |
453 | return bio_vec->bv_len; | |
454 | else | |
455 | return max; | |
456 | } | |
457 | ||
458 | /* | |
459 | * This routine returns the disk from which the requested read should | |
460 | * be done. There is a per-array 'next expected sequential IO' sector | |
461 | * number - if this matches on the next IO then we use the last disk. | |
462 | * There is also a per-disk 'last know head position' sector that is | |
463 | * maintained from IRQ contexts, both the normal and the resync IO | |
464 | * completion handlers update this position correctly. If there is no | |
465 | * perfect sequential match then we pick the disk whose head is closest. | |
466 | * | |
467 | * If there are 2 mirrors in the same 2 devices, performance degrades | |
468 | * because position is mirror, not device based. | |
469 | * | |
470 | * The rdev for the device selected will have nr_pending incremented. | |
471 | */ | |
472 | ||
473 | /* | |
474 | * FIXME: possibly should rethink readbalancing and do it differently | |
475 | * depending on near_copies / far_copies geometry. | |
476 | */ | |
477 | static int read_balance(conf_t *conf, r10bio_t *r10_bio) | |
478 | { | |
479 | const unsigned long this_sector = r10_bio->sector; | |
480 | int disk, slot, nslot; | |
481 | const int sectors = r10_bio->sectors; | |
482 | sector_t new_distance, current_distance; | |
d6065f7b | 483 | mdk_rdev_t *rdev; |
1da177e4 LT |
484 | |
485 | raid10_find_phys(conf, r10_bio); | |
486 | rcu_read_lock(); | |
487 | /* | |
488 | * Check if we can balance. We can balance on the whole | |
489 | * device if no resync is going on, or below the resync window. | |
490 | * We take the first readable disk when above the resync window. | |
491 | */ | |
492 | if (conf->mddev->recovery_cp < MaxSector | |
493 | && (this_sector + sectors >= conf->next_resync)) { | |
494 | /* make sure that disk is operational */ | |
495 | slot = 0; | |
496 | disk = r10_bio->devs[slot].devnum; | |
497 | ||
d6065f7b | 498 | while ((rdev = rcu_dereference(conf->mirrors[disk].rdev)) == NULL || |
b2d444d7 | 499 | !test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
500 | slot++; |
501 | if (slot == conf->copies) { | |
502 | slot = 0; | |
503 | disk = -1; | |
504 | break; | |
505 | } | |
506 | disk = r10_bio->devs[slot].devnum; | |
507 | } | |
508 | goto rb_out; | |
509 | } | |
510 | ||
511 | ||
512 | /* make sure the disk is operational */ | |
513 | slot = 0; | |
514 | disk = r10_bio->devs[slot].devnum; | |
d6065f7b | 515 | while ((rdev=rcu_dereference(conf->mirrors[disk].rdev)) == NULL || |
b2d444d7 | 516 | !test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
517 | slot ++; |
518 | if (slot == conf->copies) { | |
519 | disk = -1; | |
520 | goto rb_out; | |
521 | } | |
522 | disk = r10_bio->devs[slot].devnum; | |
523 | } | |
524 | ||
525 | ||
3ec67ac1 N |
526 | current_distance = abs(r10_bio->devs[slot].addr - |
527 | conf->mirrors[disk].head_position); | |
1da177e4 LT |
528 | |
529 | /* Find the disk whose head is closest */ | |
530 | ||
531 | for (nslot = slot; nslot < conf->copies; nslot++) { | |
532 | int ndisk = r10_bio->devs[nslot].devnum; | |
533 | ||
534 | ||
d6065f7b | 535 | if ((rdev=rcu_dereference(conf->mirrors[ndisk].rdev)) == NULL || |
b2d444d7 | 536 | !test_bit(In_sync, &rdev->flags)) |
1da177e4 LT |
537 | continue; |
538 | ||
22dfdf52 N |
539 | /* This optimisation is debatable, and completely destroys |
540 | * sequential read speed for 'far copies' arrays. So only | |
541 | * keep it for 'near' arrays, and review those later. | |
542 | */ | |
543 | if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) { | |
1da177e4 LT |
544 | disk = ndisk; |
545 | slot = nslot; | |
546 | break; | |
547 | } | |
548 | new_distance = abs(r10_bio->devs[nslot].addr - | |
549 | conf->mirrors[ndisk].head_position); | |
550 | if (new_distance < current_distance) { | |
551 | current_distance = new_distance; | |
552 | disk = ndisk; | |
553 | slot = nslot; | |
554 | } | |
555 | } | |
556 | ||
557 | rb_out: | |
558 | r10_bio->read_slot = slot; | |
559 | /* conf->next_seq_sect = this_sector + sectors;*/ | |
560 | ||
d6065f7b | 561 | if (disk >= 0 && (rdev=rcu_dereference(conf->mirrors[disk].rdev))!= NULL) |
1da177e4 LT |
562 | atomic_inc(&conf->mirrors[disk].rdev->nr_pending); |
563 | rcu_read_unlock(); | |
564 | ||
565 | return disk; | |
566 | } | |
567 | ||
568 | static void unplug_slaves(mddev_t *mddev) | |
569 | { | |
570 | conf_t *conf = mddev_to_conf(mddev); | |
571 | int i; | |
572 | ||
573 | rcu_read_lock(); | |
574 | for (i=0; i<mddev->raid_disks; i++) { | |
d6065f7b | 575 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); |
b2d444d7 | 576 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { |
1da177e4 LT |
577 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); |
578 | ||
579 | atomic_inc(&rdev->nr_pending); | |
580 | rcu_read_unlock(); | |
581 | ||
582 | if (r_queue->unplug_fn) | |
583 | r_queue->unplug_fn(r_queue); | |
584 | ||
585 | rdev_dec_pending(rdev, mddev); | |
586 | rcu_read_lock(); | |
587 | } | |
588 | } | |
589 | rcu_read_unlock(); | |
590 | } | |
591 | ||
592 | static void raid10_unplug(request_queue_t *q) | |
593 | { | |
594 | unplug_slaves(q->queuedata); | |
595 | } | |
596 | ||
597 | static int raid10_issue_flush(request_queue_t *q, struct gendisk *disk, | |
598 | sector_t *error_sector) | |
599 | { | |
600 | mddev_t *mddev = q->queuedata; | |
601 | conf_t *conf = mddev_to_conf(mddev); | |
602 | int i, ret = 0; | |
603 | ||
604 | rcu_read_lock(); | |
605 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { | |
d6065f7b | 606 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); |
b2d444d7 | 607 | if (rdev && !test_bit(Faulty, &rdev->flags)) { |
1da177e4 LT |
608 | struct block_device *bdev = rdev->bdev; |
609 | request_queue_t *r_queue = bdev_get_queue(bdev); | |
610 | ||
611 | if (!r_queue->issue_flush_fn) | |
612 | ret = -EOPNOTSUPP; | |
613 | else { | |
614 | atomic_inc(&rdev->nr_pending); | |
615 | rcu_read_unlock(); | |
616 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, | |
617 | error_sector); | |
618 | rdev_dec_pending(rdev, mddev); | |
619 | rcu_read_lock(); | |
620 | } | |
621 | } | |
622 | } | |
623 | rcu_read_unlock(); | |
624 | return ret; | |
625 | } | |
626 | ||
0a27ec96 N |
627 | /* Barriers.... |
628 | * Sometimes we need to suspend IO while we do something else, | |
629 | * either some resync/recovery, or reconfigure the array. | |
630 | * To do this we raise a 'barrier'. | |
631 | * The 'barrier' is a counter that can be raised multiple times | |
632 | * to count how many activities are happening which preclude | |
633 | * normal IO. | |
634 | * We can only raise the barrier if there is no pending IO. | |
635 | * i.e. if nr_pending == 0. | |
636 | * We choose only to raise the barrier if no-one is waiting for the | |
637 | * barrier to go down. This means that as soon as an IO request | |
638 | * is ready, no other operations which require a barrier will start | |
639 | * until the IO request has had a chance. | |
640 | * | |
641 | * So: regular IO calls 'wait_barrier'. When that returns there | |
642 | * is no backgroup IO happening, It must arrange to call | |
643 | * allow_barrier when it has finished its IO. | |
644 | * backgroup IO calls must call raise_barrier. Once that returns | |
645 | * there is no normal IO happeing. It must arrange to call | |
646 | * lower_barrier when the particular background IO completes. | |
1da177e4 LT |
647 | */ |
648 | #define RESYNC_DEPTH 32 | |
649 | ||
0a27ec96 | 650 | static void raise_barrier(conf_t *conf) |
1da177e4 LT |
651 | { |
652 | spin_lock_irq(&conf->resync_lock); | |
0a27ec96 N |
653 | |
654 | /* Wait until no block IO is waiting */ | |
655 | wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting, | |
656 | conf->resync_lock, | |
657 | raid10_unplug(conf->mddev->queue)); | |
658 | ||
659 | /* block any new IO from starting */ | |
660 | conf->barrier++; | |
661 | ||
662 | /* No wait for all pending IO to complete */ | |
663 | wait_event_lock_irq(conf->wait_barrier, | |
664 | !conf->nr_pending && conf->barrier < RESYNC_DEPTH, | |
665 | conf->resync_lock, | |
666 | raid10_unplug(conf->mddev->queue)); | |
667 | ||
668 | spin_unlock_irq(&conf->resync_lock); | |
669 | } | |
670 | ||
671 | static void lower_barrier(conf_t *conf) | |
672 | { | |
673 | unsigned long flags; | |
674 | spin_lock_irqsave(&conf->resync_lock, flags); | |
675 | conf->barrier--; | |
676 | spin_unlock_irqrestore(&conf->resync_lock, flags); | |
677 | wake_up(&conf->wait_barrier); | |
678 | } | |
679 | ||
680 | static void wait_barrier(conf_t *conf) | |
681 | { | |
682 | spin_lock_irq(&conf->resync_lock); | |
683 | if (conf->barrier) { | |
684 | conf->nr_waiting++; | |
685 | wait_event_lock_irq(conf->wait_barrier, !conf->barrier, | |
686 | conf->resync_lock, | |
687 | raid10_unplug(conf->mddev->queue)); | |
688 | conf->nr_waiting--; | |
1da177e4 | 689 | } |
0a27ec96 | 690 | conf->nr_pending++; |
1da177e4 LT |
691 | spin_unlock_irq(&conf->resync_lock); |
692 | } | |
693 | ||
0a27ec96 N |
694 | static void allow_barrier(conf_t *conf) |
695 | { | |
696 | unsigned long flags; | |
697 | spin_lock_irqsave(&conf->resync_lock, flags); | |
698 | conf->nr_pending--; | |
699 | spin_unlock_irqrestore(&conf->resync_lock, flags); | |
700 | wake_up(&conf->wait_barrier); | |
701 | } | |
702 | ||
1da177e4 LT |
703 | static int make_request(request_queue_t *q, struct bio * bio) |
704 | { | |
705 | mddev_t *mddev = q->queuedata; | |
706 | conf_t *conf = mddev_to_conf(mddev); | |
707 | mirror_info_t *mirror; | |
708 | r10bio_t *r10_bio; | |
709 | struct bio *read_bio; | |
710 | int i; | |
711 | int chunk_sects = conf->chunk_mask + 1; | |
a362357b | 712 | const int rw = bio_data_dir(bio); |
1da177e4 | 713 | |
e5dcdd80 N |
714 | if (unlikely(bio_barrier(bio))) { |
715 | bio_endio(bio, bio->bi_size, -EOPNOTSUPP); | |
716 | return 0; | |
717 | } | |
718 | ||
1da177e4 LT |
719 | /* If this request crosses a chunk boundary, we need to |
720 | * split it. This will only happen for 1 PAGE (or less) requests. | |
721 | */ | |
722 | if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9) | |
723 | > chunk_sects && | |
724 | conf->near_copies < conf->raid_disks)) { | |
725 | struct bio_pair *bp; | |
726 | /* Sanity check -- queue functions should prevent this happening */ | |
727 | if (bio->bi_vcnt != 1 || | |
728 | bio->bi_idx != 0) | |
729 | goto bad_map; | |
730 | /* This is a one page bio that upper layers | |
731 | * refuse to split for us, so we need to split it. | |
732 | */ | |
733 | bp = bio_split(bio, bio_split_pool, | |
734 | chunk_sects - (bio->bi_sector & (chunk_sects - 1)) ); | |
735 | if (make_request(q, &bp->bio1)) | |
736 | generic_make_request(&bp->bio1); | |
737 | if (make_request(q, &bp->bio2)) | |
738 | generic_make_request(&bp->bio2); | |
739 | ||
740 | bio_pair_release(bp); | |
741 | return 0; | |
742 | bad_map: | |
743 | printk("raid10_make_request bug: can't convert block across chunks" | |
744 | " or bigger than %dk %llu %d\n", chunk_sects/2, | |
745 | (unsigned long long)bio->bi_sector, bio->bi_size >> 10); | |
746 | ||
747 | bio_io_error(bio, bio->bi_size); | |
748 | return 0; | |
749 | } | |
750 | ||
3d310eb7 | 751 | md_write_start(mddev, bio); |
06d91a5f | 752 | |
1da177e4 LT |
753 | /* |
754 | * Register the new request and wait if the reconstruction | |
755 | * thread has put up a bar for new requests. | |
756 | * Continue immediately if no resync is active currently. | |
757 | */ | |
0a27ec96 | 758 | wait_barrier(conf); |
1da177e4 | 759 | |
a362357b JA |
760 | disk_stat_inc(mddev->gendisk, ios[rw]); |
761 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio)); | |
1da177e4 LT |
762 | |
763 | r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO); | |
764 | ||
765 | r10_bio->master_bio = bio; | |
766 | r10_bio->sectors = bio->bi_size >> 9; | |
767 | ||
768 | r10_bio->mddev = mddev; | |
769 | r10_bio->sector = bio->bi_sector; | |
770 | ||
a362357b | 771 | if (rw == READ) { |
1da177e4 LT |
772 | /* |
773 | * read balancing logic: | |
774 | */ | |
775 | int disk = read_balance(conf, r10_bio); | |
776 | int slot = r10_bio->read_slot; | |
777 | if (disk < 0) { | |
778 | raid_end_bio_io(r10_bio); | |
779 | return 0; | |
780 | } | |
781 | mirror = conf->mirrors + disk; | |
782 | ||
783 | read_bio = bio_clone(bio, GFP_NOIO); | |
784 | ||
785 | r10_bio->devs[slot].bio = read_bio; | |
786 | ||
787 | read_bio->bi_sector = r10_bio->devs[slot].addr + | |
788 | mirror->rdev->data_offset; | |
789 | read_bio->bi_bdev = mirror->rdev->bdev; | |
790 | read_bio->bi_end_io = raid10_end_read_request; | |
791 | read_bio->bi_rw = READ; | |
792 | read_bio->bi_private = r10_bio; | |
793 | ||
794 | generic_make_request(read_bio); | |
795 | return 0; | |
796 | } | |
797 | ||
798 | /* | |
799 | * WRITE: | |
800 | */ | |
801 | /* first select target devices under spinlock and | |
802 | * inc refcount on their rdev. Record them by setting | |
803 | * bios[x] to bio | |
804 | */ | |
805 | raid10_find_phys(conf, r10_bio); | |
806 | rcu_read_lock(); | |
807 | for (i = 0; i < conf->copies; i++) { | |
808 | int d = r10_bio->devs[i].devnum; | |
d6065f7b SW |
809 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev); |
810 | if (rdev && | |
b2d444d7 | 811 | !test_bit(Faulty, &rdev->flags)) { |
d6065f7b | 812 | atomic_inc(&rdev->nr_pending); |
1da177e4 LT |
813 | r10_bio->devs[i].bio = bio; |
814 | } else | |
815 | r10_bio->devs[i].bio = NULL; | |
816 | } | |
817 | rcu_read_unlock(); | |
818 | ||
819 | atomic_set(&r10_bio->remaining, 1); | |
06d91a5f | 820 | |
1da177e4 LT |
821 | for (i = 0; i < conf->copies; i++) { |
822 | struct bio *mbio; | |
823 | int d = r10_bio->devs[i].devnum; | |
824 | if (!r10_bio->devs[i].bio) | |
825 | continue; | |
826 | ||
827 | mbio = bio_clone(bio, GFP_NOIO); | |
828 | r10_bio->devs[i].bio = mbio; | |
829 | ||
830 | mbio->bi_sector = r10_bio->devs[i].addr+ | |
831 | conf->mirrors[d].rdev->data_offset; | |
832 | mbio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
833 | mbio->bi_end_io = raid10_end_write_request; | |
834 | mbio->bi_rw = WRITE; | |
835 | mbio->bi_private = r10_bio; | |
836 | ||
837 | atomic_inc(&r10_bio->remaining); | |
838 | generic_make_request(mbio); | |
839 | } | |
840 | ||
841 | if (atomic_dec_and_test(&r10_bio->remaining)) { | |
842 | md_write_end(mddev); | |
843 | raid_end_bio_io(r10_bio); | |
844 | } | |
845 | ||
846 | return 0; | |
847 | } | |
848 | ||
849 | static void status(struct seq_file *seq, mddev_t *mddev) | |
850 | { | |
851 | conf_t *conf = mddev_to_conf(mddev); | |
852 | int i; | |
853 | ||
854 | if (conf->near_copies < conf->raid_disks) | |
855 | seq_printf(seq, " %dK chunks", mddev->chunk_size/1024); | |
856 | if (conf->near_copies > 1) | |
857 | seq_printf(seq, " %d near-copies", conf->near_copies); | |
858 | if (conf->far_copies > 1) | |
859 | seq_printf(seq, " %d far-copies", conf->far_copies); | |
860 | ||
861 | seq_printf(seq, " [%d/%d] [", conf->raid_disks, | |
862 | conf->working_disks); | |
863 | for (i = 0; i < conf->raid_disks; i++) | |
864 | seq_printf(seq, "%s", | |
865 | conf->mirrors[i].rdev && | |
b2d444d7 | 866 | test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
867 | seq_printf(seq, "]"); |
868 | } | |
869 | ||
870 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) | |
871 | { | |
872 | char b[BDEVNAME_SIZE]; | |
873 | conf_t *conf = mddev_to_conf(mddev); | |
874 | ||
875 | /* | |
876 | * If it is not operational, then we have already marked it as dead | |
877 | * else if it is the last working disks, ignore the error, let the | |
878 | * next level up know. | |
879 | * else mark the drive as failed | |
880 | */ | |
b2d444d7 | 881 | if (test_bit(In_sync, &rdev->flags) |
1da177e4 LT |
882 | && conf->working_disks == 1) |
883 | /* | |
884 | * Don't fail the drive, just return an IO error. | |
885 | * The test should really be more sophisticated than | |
886 | * "working_disks == 1", but it isn't critical, and | |
887 | * can wait until we do more sophisticated "is the drive | |
888 | * really dead" tests... | |
889 | */ | |
890 | return; | |
b2d444d7 | 891 | if (test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
892 | mddev->degraded++; |
893 | conf->working_disks--; | |
894 | /* | |
895 | * if recovery is running, make sure it aborts. | |
896 | */ | |
897 | set_bit(MD_RECOVERY_ERR, &mddev->recovery); | |
898 | } | |
b2d444d7 N |
899 | clear_bit(In_sync, &rdev->flags); |
900 | set_bit(Faulty, &rdev->flags); | |
1da177e4 LT |
901 | mddev->sb_dirty = 1; |
902 | printk(KERN_ALERT "raid10: Disk failure on %s, disabling device. \n" | |
903 | " Operation continuing on %d devices\n", | |
904 | bdevname(rdev->bdev,b), conf->working_disks); | |
905 | } | |
906 | ||
907 | static void print_conf(conf_t *conf) | |
908 | { | |
909 | int i; | |
910 | mirror_info_t *tmp; | |
911 | ||
912 | printk("RAID10 conf printout:\n"); | |
913 | if (!conf) { | |
914 | printk("(!conf)\n"); | |
915 | return; | |
916 | } | |
917 | printk(" --- wd:%d rd:%d\n", conf->working_disks, | |
918 | conf->raid_disks); | |
919 | ||
920 | for (i = 0; i < conf->raid_disks; i++) { | |
921 | char b[BDEVNAME_SIZE]; | |
922 | tmp = conf->mirrors + i; | |
923 | if (tmp->rdev) | |
924 | printk(" disk %d, wo:%d, o:%d, dev:%s\n", | |
b2d444d7 N |
925 | i, !test_bit(In_sync, &tmp->rdev->flags), |
926 | !test_bit(Faulty, &tmp->rdev->flags), | |
1da177e4 LT |
927 | bdevname(tmp->rdev->bdev,b)); |
928 | } | |
929 | } | |
930 | ||
931 | static void close_sync(conf_t *conf) | |
932 | { | |
0a27ec96 N |
933 | wait_barrier(conf); |
934 | allow_barrier(conf); | |
1da177e4 LT |
935 | |
936 | mempool_destroy(conf->r10buf_pool); | |
937 | conf->r10buf_pool = NULL; | |
938 | } | |
939 | ||
6d508242 N |
940 | /* check if there are enough drives for |
941 | * every block to appear on atleast one | |
942 | */ | |
943 | static int enough(conf_t *conf) | |
944 | { | |
945 | int first = 0; | |
946 | ||
947 | do { | |
948 | int n = conf->copies; | |
949 | int cnt = 0; | |
950 | while (n--) { | |
951 | if (conf->mirrors[first].rdev) | |
952 | cnt++; | |
953 | first = (first+1) % conf->raid_disks; | |
954 | } | |
955 | if (cnt == 0) | |
956 | return 0; | |
957 | } while (first != 0); | |
958 | return 1; | |
959 | } | |
960 | ||
1da177e4 LT |
961 | static int raid10_spare_active(mddev_t *mddev) |
962 | { | |
963 | int i; | |
964 | conf_t *conf = mddev->private; | |
965 | mirror_info_t *tmp; | |
966 | ||
967 | /* | |
968 | * Find all non-in_sync disks within the RAID10 configuration | |
969 | * and mark them in_sync | |
970 | */ | |
971 | for (i = 0; i < conf->raid_disks; i++) { | |
972 | tmp = conf->mirrors + i; | |
973 | if (tmp->rdev | |
b2d444d7 N |
974 | && !test_bit(Faulty, &tmp->rdev->flags) |
975 | && !test_bit(In_sync, &tmp->rdev->flags)) { | |
1da177e4 LT |
976 | conf->working_disks++; |
977 | mddev->degraded--; | |
b2d444d7 | 978 | set_bit(In_sync, &tmp->rdev->flags); |
1da177e4 LT |
979 | } |
980 | } | |
981 | ||
982 | print_conf(conf); | |
983 | return 0; | |
984 | } | |
985 | ||
986 | ||
987 | static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
988 | { | |
989 | conf_t *conf = mddev->private; | |
990 | int found = 0; | |
991 | int mirror; | |
992 | mirror_info_t *p; | |
993 | ||
994 | if (mddev->recovery_cp < MaxSector) | |
995 | /* only hot-add to in-sync arrays, as recovery is | |
996 | * very different from resync | |
997 | */ | |
998 | return 0; | |
6d508242 N |
999 | if (!enough(conf)) |
1000 | return 0; | |
1da177e4 LT |
1001 | |
1002 | for (mirror=0; mirror < mddev->raid_disks; mirror++) | |
1003 | if ( !(p=conf->mirrors+mirror)->rdev) { | |
1004 | ||
1005 | blk_queue_stack_limits(mddev->queue, | |
1006 | rdev->bdev->bd_disk->queue); | |
1007 | /* as we don't honour merge_bvec_fn, we must never risk | |
1008 | * violating it, so limit ->max_sector to one PAGE, as | |
1009 | * a one page request is never in violation. | |
1010 | */ | |
1011 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
1012 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) | |
1013 | mddev->queue->max_sectors = (PAGE_SIZE>>9); | |
1014 | ||
1015 | p->head_position = 0; | |
1016 | rdev->raid_disk = mirror; | |
1017 | found = 1; | |
d6065f7b | 1018 | rcu_assign_pointer(p->rdev, rdev); |
1da177e4 LT |
1019 | break; |
1020 | } | |
1021 | ||
1022 | print_conf(conf); | |
1023 | return found; | |
1024 | } | |
1025 | ||
1026 | static int raid10_remove_disk(mddev_t *mddev, int number) | |
1027 | { | |
1028 | conf_t *conf = mddev->private; | |
1029 | int err = 0; | |
1030 | mdk_rdev_t *rdev; | |
1031 | mirror_info_t *p = conf->mirrors+ number; | |
1032 | ||
1033 | print_conf(conf); | |
1034 | rdev = p->rdev; | |
1035 | if (rdev) { | |
b2d444d7 | 1036 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 LT |
1037 | atomic_read(&rdev->nr_pending)) { |
1038 | err = -EBUSY; | |
1039 | goto abort; | |
1040 | } | |
1041 | p->rdev = NULL; | |
fbd568a3 | 1042 | synchronize_rcu(); |
1da177e4 LT |
1043 | if (atomic_read(&rdev->nr_pending)) { |
1044 | /* lost the race, try later */ | |
1045 | err = -EBUSY; | |
1046 | p->rdev = rdev; | |
1047 | } | |
1048 | } | |
1049 | abort: | |
1050 | ||
1051 | print_conf(conf); | |
1052 | return err; | |
1053 | } | |
1054 | ||
1055 | ||
1056 | static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error) | |
1057 | { | |
1058 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
1059 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
1060 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
1061 | int i,d; | |
1062 | ||
1063 | if (bio->bi_size) | |
1064 | return 1; | |
1065 | ||
1066 | for (i=0; i<conf->copies; i++) | |
1067 | if (r10_bio->devs[i].bio == bio) | |
1068 | break; | |
1069 | if (i == conf->copies) | |
1070 | BUG(); | |
1071 | update_head_pos(i, r10_bio); | |
1072 | d = r10_bio->devs[i].devnum; | |
1073 | if (!uptodate) | |
1074 | md_error(r10_bio->mddev, | |
1075 | conf->mirrors[d].rdev); | |
1076 | ||
1077 | /* for reconstruct, we always reschedule after a read. | |
1078 | * for resync, only after all reads | |
1079 | */ | |
1080 | if (test_bit(R10BIO_IsRecover, &r10_bio->state) || | |
1081 | atomic_dec_and_test(&r10_bio->remaining)) { | |
1082 | /* we have read all the blocks, | |
1083 | * do the comparison in process context in raid10d | |
1084 | */ | |
1085 | reschedule_retry(r10_bio); | |
1086 | } | |
1087 | rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev); | |
1088 | return 0; | |
1089 | } | |
1090 | ||
1091 | static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error) | |
1092 | { | |
1093 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
1094 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
1095 | mddev_t *mddev = r10_bio->mddev; | |
1096 | conf_t *conf = mddev_to_conf(mddev); | |
1097 | int i,d; | |
1098 | ||
1099 | if (bio->bi_size) | |
1100 | return 1; | |
1101 | ||
1102 | for (i = 0; i < conf->copies; i++) | |
1103 | if (r10_bio->devs[i].bio == bio) | |
1104 | break; | |
1105 | d = r10_bio->devs[i].devnum; | |
1106 | ||
1107 | if (!uptodate) | |
1108 | md_error(mddev, conf->mirrors[d].rdev); | |
1109 | update_head_pos(i, r10_bio); | |
1110 | ||
1111 | while (atomic_dec_and_test(&r10_bio->remaining)) { | |
1112 | if (r10_bio->master_bio == NULL) { | |
1113 | /* the primary of several recovery bios */ | |
1114 | md_done_sync(mddev, r10_bio->sectors, 1); | |
1115 | put_buf(r10_bio); | |
1116 | break; | |
1117 | } else { | |
1118 | r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio; | |
1119 | put_buf(r10_bio); | |
1120 | r10_bio = r10_bio2; | |
1121 | } | |
1122 | } | |
1123 | rdev_dec_pending(conf->mirrors[d].rdev, mddev); | |
1124 | return 0; | |
1125 | } | |
1126 | ||
1127 | /* | |
1128 | * Note: sync and recover and handled very differently for raid10 | |
1129 | * This code is for resync. | |
1130 | * For resync, we read through virtual addresses and read all blocks. | |
1131 | * If there is any error, we schedule a write. The lowest numbered | |
1132 | * drive is authoritative. | |
1133 | * However requests come for physical address, so we need to map. | |
1134 | * For every physical address there are raid_disks/copies virtual addresses, | |
1135 | * which is always are least one, but is not necessarly an integer. | |
1136 | * This means that a physical address can span multiple chunks, so we may | |
1137 | * have to submit multiple io requests for a single sync request. | |
1138 | */ | |
1139 | /* | |
1140 | * We check if all blocks are in-sync and only write to blocks that | |
1141 | * aren't in sync | |
1142 | */ | |
1143 | static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio) | |
1144 | { | |
1145 | conf_t *conf = mddev_to_conf(mddev); | |
1146 | int i, first; | |
1147 | struct bio *tbio, *fbio; | |
1148 | ||
1149 | atomic_set(&r10_bio->remaining, 1); | |
1150 | ||
1151 | /* find the first device with a block */ | |
1152 | for (i=0; i<conf->copies; i++) | |
1153 | if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) | |
1154 | break; | |
1155 | ||
1156 | if (i == conf->copies) | |
1157 | goto done; | |
1158 | ||
1159 | first = i; | |
1160 | fbio = r10_bio->devs[i].bio; | |
1161 | ||
1162 | /* now find blocks with errors */ | |
1163 | for (i=first+1 ; i < conf->copies ; i++) { | |
1164 | int vcnt, j, d; | |
1165 | ||
1166 | if (!test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) | |
1167 | continue; | |
1168 | /* We know that the bi_io_vec layout is the same for | |
1169 | * both 'first' and 'i', so we just compare them. | |
1170 | * All vec entries are PAGE_SIZE; | |
1171 | */ | |
1172 | tbio = r10_bio->devs[i].bio; | |
1173 | vcnt = r10_bio->sectors >> (PAGE_SHIFT-9); | |
1174 | for (j = 0; j < vcnt; j++) | |
1175 | if (memcmp(page_address(fbio->bi_io_vec[j].bv_page), | |
1176 | page_address(tbio->bi_io_vec[j].bv_page), | |
1177 | PAGE_SIZE)) | |
1178 | break; | |
1179 | if (j == vcnt) | |
1180 | continue; | |
1181 | /* Ok, we need to write this bio | |
1182 | * First we need to fixup bv_offset, bv_len and | |
1183 | * bi_vecs, as the read request might have corrupted these | |
1184 | */ | |
1185 | tbio->bi_vcnt = vcnt; | |
1186 | tbio->bi_size = r10_bio->sectors << 9; | |
1187 | tbio->bi_idx = 0; | |
1188 | tbio->bi_phys_segments = 0; | |
1189 | tbio->bi_hw_segments = 0; | |
1190 | tbio->bi_hw_front_size = 0; | |
1191 | tbio->bi_hw_back_size = 0; | |
1192 | tbio->bi_flags &= ~(BIO_POOL_MASK - 1); | |
1193 | tbio->bi_flags |= 1 << BIO_UPTODATE; | |
1194 | tbio->bi_next = NULL; | |
1195 | tbio->bi_rw = WRITE; | |
1196 | tbio->bi_private = r10_bio; | |
1197 | tbio->bi_sector = r10_bio->devs[i].addr; | |
1198 | ||
1199 | for (j=0; j < vcnt ; j++) { | |
1200 | tbio->bi_io_vec[j].bv_offset = 0; | |
1201 | tbio->bi_io_vec[j].bv_len = PAGE_SIZE; | |
1202 | ||
1203 | memcpy(page_address(tbio->bi_io_vec[j].bv_page), | |
1204 | page_address(fbio->bi_io_vec[j].bv_page), | |
1205 | PAGE_SIZE); | |
1206 | } | |
1207 | tbio->bi_end_io = end_sync_write; | |
1208 | ||
1209 | d = r10_bio->devs[i].devnum; | |
1210 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1211 | atomic_inc(&r10_bio->remaining); | |
1212 | md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9); | |
1213 | ||
1214 | tbio->bi_sector += conf->mirrors[d].rdev->data_offset; | |
1215 | tbio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1216 | generic_make_request(tbio); | |
1217 | } | |
1218 | ||
1219 | done: | |
1220 | if (atomic_dec_and_test(&r10_bio->remaining)) { | |
1221 | md_done_sync(mddev, r10_bio->sectors, 1); | |
1222 | put_buf(r10_bio); | |
1223 | } | |
1224 | } | |
1225 | ||
1226 | /* | |
1227 | * Now for the recovery code. | |
1228 | * Recovery happens across physical sectors. | |
1229 | * We recover all non-is_sync drives by finding the virtual address of | |
1230 | * each, and then choose a working drive that also has that virt address. | |
1231 | * There is a separate r10_bio for each non-in_sync drive. | |
1232 | * Only the first two slots are in use. The first for reading, | |
1233 | * The second for writing. | |
1234 | * | |
1235 | */ | |
1236 | ||
1237 | static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio) | |
1238 | { | |
1239 | conf_t *conf = mddev_to_conf(mddev); | |
1240 | int i, d; | |
1241 | struct bio *bio, *wbio; | |
1242 | ||
1243 | ||
1244 | /* move the pages across to the second bio | |
1245 | * and submit the write request | |
1246 | */ | |
1247 | bio = r10_bio->devs[0].bio; | |
1248 | wbio = r10_bio->devs[1].bio; | |
1249 | for (i=0; i < wbio->bi_vcnt; i++) { | |
1250 | struct page *p = bio->bi_io_vec[i].bv_page; | |
1251 | bio->bi_io_vec[i].bv_page = wbio->bi_io_vec[i].bv_page; | |
1252 | wbio->bi_io_vec[i].bv_page = p; | |
1253 | } | |
1254 | d = r10_bio->devs[1].devnum; | |
1255 | ||
1256 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1257 | md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9); | |
1258 | generic_make_request(wbio); | |
1259 | } | |
1260 | ||
1261 | ||
1262 | /* | |
1263 | * This is a kernel thread which: | |
1264 | * | |
1265 | * 1. Retries failed read operations on working mirrors. | |
1266 | * 2. Updates the raid superblock when problems encounter. | |
1267 | * 3. Performs writes following reads for array syncronising. | |
1268 | */ | |
1269 | ||
1270 | static void raid10d(mddev_t *mddev) | |
1271 | { | |
1272 | r10bio_t *r10_bio; | |
1273 | struct bio *bio; | |
1274 | unsigned long flags; | |
1275 | conf_t *conf = mddev_to_conf(mddev); | |
1276 | struct list_head *head = &conf->retry_list; | |
1277 | int unplug=0; | |
1278 | mdk_rdev_t *rdev; | |
1279 | ||
1280 | md_check_recovery(mddev); | |
1da177e4 LT |
1281 | |
1282 | for (;;) { | |
1283 | char b[BDEVNAME_SIZE]; | |
1284 | spin_lock_irqsave(&conf->device_lock, flags); | |
1285 | if (list_empty(head)) | |
1286 | break; | |
1287 | r10_bio = list_entry(head->prev, r10bio_t, retry_list); | |
1288 | list_del(head->prev); | |
1289 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1290 | ||
1291 | mddev = r10_bio->mddev; | |
1292 | conf = mddev_to_conf(mddev); | |
1293 | if (test_bit(R10BIO_IsSync, &r10_bio->state)) { | |
1294 | sync_request_write(mddev, r10_bio); | |
1295 | unplug = 1; | |
1296 | } else if (test_bit(R10BIO_IsRecover, &r10_bio->state)) { | |
1297 | recovery_request_write(mddev, r10_bio); | |
1298 | unplug = 1; | |
1299 | } else { | |
1300 | int mirror; | |
1301 | bio = r10_bio->devs[r10_bio->read_slot].bio; | |
1302 | r10_bio->devs[r10_bio->read_slot].bio = NULL; | |
1303 | bio_put(bio); | |
1304 | mirror = read_balance(conf, r10_bio); | |
1305 | if (mirror == -1) { | |
1306 | printk(KERN_ALERT "raid10: %s: unrecoverable I/O" | |
1307 | " read error for block %llu\n", | |
1308 | bdevname(bio->bi_bdev,b), | |
1309 | (unsigned long long)r10_bio->sector); | |
1310 | raid_end_bio_io(r10_bio); | |
1311 | } else { | |
1312 | rdev = conf->mirrors[mirror].rdev; | |
1313 | if (printk_ratelimit()) | |
1314 | printk(KERN_ERR "raid10: %s: redirecting sector %llu to" | |
1315 | " another mirror\n", | |
1316 | bdevname(rdev->bdev,b), | |
1317 | (unsigned long long)r10_bio->sector); | |
1318 | bio = bio_clone(r10_bio->master_bio, GFP_NOIO); | |
1319 | r10_bio->devs[r10_bio->read_slot].bio = bio; | |
1320 | bio->bi_sector = r10_bio->devs[r10_bio->read_slot].addr | |
1321 | + rdev->data_offset; | |
1322 | bio->bi_bdev = rdev->bdev; | |
1323 | bio->bi_rw = READ; | |
1324 | bio->bi_private = r10_bio; | |
1325 | bio->bi_end_io = raid10_end_read_request; | |
1326 | unplug = 1; | |
1327 | generic_make_request(bio); | |
1328 | } | |
1329 | } | |
1330 | } | |
1331 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1332 | if (unplug) | |
1333 | unplug_slaves(mddev); | |
1334 | } | |
1335 | ||
1336 | ||
1337 | static int init_resync(conf_t *conf) | |
1338 | { | |
1339 | int buffs; | |
1340 | ||
1341 | buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; | |
1342 | if (conf->r10buf_pool) | |
1343 | BUG(); | |
1344 | conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf); | |
1345 | if (!conf->r10buf_pool) | |
1346 | return -ENOMEM; | |
1347 | conf->next_resync = 0; | |
1348 | return 0; | |
1349 | } | |
1350 | ||
1351 | /* | |
1352 | * perform a "sync" on one "block" | |
1353 | * | |
1354 | * We need to make sure that no normal I/O request - particularly write | |
1355 | * requests - conflict with active sync requests. | |
1356 | * | |
1357 | * This is achieved by tracking pending requests and a 'barrier' concept | |
1358 | * that can be installed to exclude normal IO requests. | |
1359 | * | |
1360 | * Resync and recovery are handled very differently. | |
1361 | * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery. | |
1362 | * | |
1363 | * For resync, we iterate over virtual addresses, read all copies, | |
1364 | * and update if there are differences. If only one copy is live, | |
1365 | * skip it. | |
1366 | * For recovery, we iterate over physical addresses, read a good | |
1367 | * value for each non-in_sync drive, and over-write. | |
1368 | * | |
1369 | * So, for recovery we may have several outstanding complex requests for a | |
1370 | * given address, one for each out-of-sync device. We model this by allocating | |
1371 | * a number of r10_bio structures, one for each out-of-sync device. | |
1372 | * As we setup these structures, we collect all bio's together into a list | |
1373 | * which we then process collectively to add pages, and then process again | |
1374 | * to pass to generic_make_request. | |
1375 | * | |
1376 | * The r10_bio structures are linked using a borrowed master_bio pointer. | |
1377 | * This link is counted in ->remaining. When the r10_bio that points to NULL | |
1378 | * has its remaining count decremented to 0, the whole complex operation | |
1379 | * is complete. | |
1380 | * | |
1381 | */ | |
1382 | ||
57afd89f | 1383 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
1da177e4 LT |
1384 | { |
1385 | conf_t *conf = mddev_to_conf(mddev); | |
1386 | r10bio_t *r10_bio; | |
1387 | struct bio *biolist = NULL, *bio; | |
1388 | sector_t max_sector, nr_sectors; | |
1389 | int disk; | |
1390 | int i; | |
1391 | ||
1392 | sector_t sectors_skipped = 0; | |
1393 | int chunks_skipped = 0; | |
1394 | ||
1395 | if (!conf->r10buf_pool) | |
1396 | if (init_resync(conf)) | |
57afd89f | 1397 | return 0; |
1da177e4 LT |
1398 | |
1399 | skipped: | |
1400 | max_sector = mddev->size << 1; | |
1401 | if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) | |
1402 | max_sector = mddev->resync_max_sectors; | |
1403 | if (sector_nr >= max_sector) { | |
1404 | close_sync(conf); | |
57afd89f | 1405 | *skipped = 1; |
1da177e4 LT |
1406 | return sectors_skipped; |
1407 | } | |
1408 | if (chunks_skipped >= conf->raid_disks) { | |
1409 | /* if there has been nothing to do on any drive, | |
1410 | * then there is nothing to do at all.. | |
1411 | */ | |
57afd89f N |
1412 | *skipped = 1; |
1413 | return (max_sector - sector_nr) + sectors_skipped; | |
1da177e4 LT |
1414 | } |
1415 | ||
1416 | /* make sure whole request will fit in a chunk - if chunks | |
1417 | * are meaningful | |
1418 | */ | |
1419 | if (conf->near_copies < conf->raid_disks && | |
1420 | max_sector > (sector_nr | conf->chunk_mask)) | |
1421 | max_sector = (sector_nr | conf->chunk_mask) + 1; | |
1422 | /* | |
1423 | * If there is non-resync activity waiting for us then | |
1424 | * put in a delay to throttle resync. | |
1425 | */ | |
0a27ec96 | 1426 | if (!go_faster && conf->nr_waiting) |
1da177e4 | 1427 | msleep_interruptible(1000); |
0a27ec96 N |
1428 | raise_barrier(conf); |
1429 | conf->next_resync = sector_nr; | |
1da177e4 LT |
1430 | |
1431 | /* Again, very different code for resync and recovery. | |
1432 | * Both must result in an r10bio with a list of bios that | |
1433 | * have bi_end_io, bi_sector, bi_bdev set, | |
1434 | * and bi_private set to the r10bio. | |
1435 | * For recovery, we may actually create several r10bios | |
1436 | * with 2 bios in each, that correspond to the bios in the main one. | |
1437 | * In this case, the subordinate r10bios link back through a | |
1438 | * borrowed master_bio pointer, and the counter in the master | |
1439 | * includes a ref from each subordinate. | |
1440 | */ | |
1441 | /* First, we decide what to do and set ->bi_end_io | |
1442 | * To end_sync_read if we want to read, and | |
1443 | * end_sync_write if we will want to write. | |
1444 | */ | |
1445 | ||
1446 | if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { | |
1447 | /* recovery... the complicated one */ | |
1448 | int i, j, k; | |
1449 | r10_bio = NULL; | |
1450 | ||
1451 | for (i=0 ; i<conf->raid_disks; i++) | |
1452 | if (conf->mirrors[i].rdev && | |
b2d444d7 | 1453 | !test_bit(In_sync, &conf->mirrors[i].rdev->flags)) { |
1da177e4 LT |
1454 | /* want to reconstruct this device */ |
1455 | r10bio_t *rb2 = r10_bio; | |
1456 | ||
1457 | r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO); | |
1458 | spin_lock_irq(&conf->resync_lock); | |
1da177e4 LT |
1459 | if (rb2) conf->barrier++; |
1460 | spin_unlock_irq(&conf->resync_lock); | |
1461 | atomic_set(&r10_bio->remaining, 0); | |
1462 | ||
1463 | r10_bio->master_bio = (struct bio*)rb2; | |
1464 | if (rb2) | |
1465 | atomic_inc(&rb2->remaining); | |
1466 | r10_bio->mddev = mddev; | |
1467 | set_bit(R10BIO_IsRecover, &r10_bio->state); | |
1468 | r10_bio->sector = raid10_find_virt(conf, sector_nr, i); | |
1469 | raid10_find_phys(conf, r10_bio); | |
1470 | for (j=0; j<conf->copies;j++) { | |
1471 | int d = r10_bio->devs[j].devnum; | |
1472 | if (conf->mirrors[d].rdev && | |
b2d444d7 | 1473 | test_bit(In_sync, &conf->mirrors[d].rdev->flags)) { |
1da177e4 LT |
1474 | /* This is where we read from */ |
1475 | bio = r10_bio->devs[0].bio; | |
1476 | bio->bi_next = biolist; | |
1477 | biolist = bio; | |
1478 | bio->bi_private = r10_bio; | |
1479 | bio->bi_end_io = end_sync_read; | |
1480 | bio->bi_rw = 0; | |
1481 | bio->bi_sector = r10_bio->devs[j].addr + | |
1482 | conf->mirrors[d].rdev->data_offset; | |
1483 | bio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1484 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1485 | atomic_inc(&r10_bio->remaining); | |
1486 | /* and we write to 'i' */ | |
1487 | ||
1488 | for (k=0; k<conf->copies; k++) | |
1489 | if (r10_bio->devs[k].devnum == i) | |
1490 | break; | |
1491 | bio = r10_bio->devs[1].bio; | |
1492 | bio->bi_next = biolist; | |
1493 | biolist = bio; | |
1494 | bio->bi_private = r10_bio; | |
1495 | bio->bi_end_io = end_sync_write; | |
1496 | bio->bi_rw = 1; | |
1497 | bio->bi_sector = r10_bio->devs[k].addr + | |
1498 | conf->mirrors[i].rdev->data_offset; | |
1499 | bio->bi_bdev = conf->mirrors[i].rdev->bdev; | |
1500 | ||
1501 | r10_bio->devs[0].devnum = d; | |
1502 | r10_bio->devs[1].devnum = i; | |
1503 | ||
1504 | break; | |
1505 | } | |
1506 | } | |
1507 | if (j == conf->copies) { | |
87fc767b N |
1508 | /* Cannot recover, so abort the recovery */ |
1509 | put_buf(r10_bio); | |
1510 | r10_bio = rb2; | |
1511 | if (!test_and_set_bit(MD_RECOVERY_ERR, &mddev->recovery)) | |
1512 | printk(KERN_INFO "raid10: %s: insufficient working devices for recovery.\n", | |
1513 | mdname(mddev)); | |
1514 | break; | |
1da177e4 LT |
1515 | } |
1516 | } | |
1517 | if (biolist == NULL) { | |
1518 | while (r10_bio) { | |
1519 | r10bio_t *rb2 = r10_bio; | |
1520 | r10_bio = (r10bio_t*) rb2->master_bio; | |
1521 | rb2->master_bio = NULL; | |
1522 | put_buf(rb2); | |
1523 | } | |
1524 | goto giveup; | |
1525 | } | |
1526 | } else { | |
1527 | /* resync. Schedule a read for every block at this virt offset */ | |
1528 | int count = 0; | |
1529 | r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO); | |
1530 | ||
1da177e4 LT |
1531 | r10_bio->mddev = mddev; |
1532 | atomic_set(&r10_bio->remaining, 0); | |
1533 | ||
1534 | r10_bio->master_bio = NULL; | |
1535 | r10_bio->sector = sector_nr; | |
1536 | set_bit(R10BIO_IsSync, &r10_bio->state); | |
1537 | raid10_find_phys(conf, r10_bio); | |
1538 | r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1; | |
1539 | ||
1540 | for (i=0; i<conf->copies; i++) { | |
1541 | int d = r10_bio->devs[i].devnum; | |
1542 | bio = r10_bio->devs[i].bio; | |
1543 | bio->bi_end_io = NULL; | |
1544 | if (conf->mirrors[d].rdev == NULL || | |
b2d444d7 | 1545 | test_bit(Faulty, &conf->mirrors[d].rdev->flags)) |
1da177e4 LT |
1546 | continue; |
1547 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1548 | atomic_inc(&r10_bio->remaining); | |
1549 | bio->bi_next = biolist; | |
1550 | biolist = bio; | |
1551 | bio->bi_private = r10_bio; | |
1552 | bio->bi_end_io = end_sync_read; | |
1553 | bio->bi_rw = 0; | |
1554 | bio->bi_sector = r10_bio->devs[i].addr + | |
1555 | conf->mirrors[d].rdev->data_offset; | |
1556 | bio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1557 | count++; | |
1558 | } | |
1559 | ||
1560 | if (count < 2) { | |
1561 | for (i=0; i<conf->copies; i++) { | |
1562 | int d = r10_bio->devs[i].devnum; | |
1563 | if (r10_bio->devs[i].bio->bi_end_io) | |
1564 | rdev_dec_pending(conf->mirrors[d].rdev, mddev); | |
1565 | } | |
1566 | put_buf(r10_bio); | |
1567 | biolist = NULL; | |
1568 | goto giveup; | |
1569 | } | |
1570 | } | |
1571 | ||
1572 | for (bio = biolist; bio ; bio=bio->bi_next) { | |
1573 | ||
1574 | bio->bi_flags &= ~(BIO_POOL_MASK - 1); | |
1575 | if (bio->bi_end_io) | |
1576 | bio->bi_flags |= 1 << BIO_UPTODATE; | |
1577 | bio->bi_vcnt = 0; | |
1578 | bio->bi_idx = 0; | |
1579 | bio->bi_phys_segments = 0; | |
1580 | bio->bi_hw_segments = 0; | |
1581 | bio->bi_size = 0; | |
1582 | } | |
1583 | ||
1584 | nr_sectors = 0; | |
1585 | do { | |
1586 | struct page *page; | |
1587 | int len = PAGE_SIZE; | |
1588 | disk = 0; | |
1589 | if (sector_nr + (len>>9) > max_sector) | |
1590 | len = (max_sector - sector_nr) << 9; | |
1591 | if (len == 0) | |
1592 | break; | |
1593 | for (bio= biolist ; bio ; bio=bio->bi_next) { | |
1594 | page = bio->bi_io_vec[bio->bi_vcnt].bv_page; | |
1595 | if (bio_add_page(bio, page, len, 0) == 0) { | |
1596 | /* stop here */ | |
1597 | struct bio *bio2; | |
1598 | bio->bi_io_vec[bio->bi_vcnt].bv_page = page; | |
1599 | for (bio2 = biolist; bio2 && bio2 != bio; bio2 = bio2->bi_next) { | |
1600 | /* remove last page from this bio */ | |
1601 | bio2->bi_vcnt--; | |
1602 | bio2->bi_size -= len; | |
1603 | bio2->bi_flags &= ~(1<< BIO_SEG_VALID); | |
1604 | } | |
1605 | goto bio_full; | |
1606 | } | |
1607 | disk = i; | |
1608 | } | |
1609 | nr_sectors += len>>9; | |
1610 | sector_nr += len>>9; | |
1611 | } while (biolist->bi_vcnt < RESYNC_PAGES); | |
1612 | bio_full: | |
1613 | r10_bio->sectors = nr_sectors; | |
1614 | ||
1615 | while (biolist) { | |
1616 | bio = biolist; | |
1617 | biolist = biolist->bi_next; | |
1618 | ||
1619 | bio->bi_next = NULL; | |
1620 | r10_bio = bio->bi_private; | |
1621 | r10_bio->sectors = nr_sectors; | |
1622 | ||
1623 | if (bio->bi_end_io == end_sync_read) { | |
1624 | md_sync_acct(bio->bi_bdev, nr_sectors); | |
1625 | generic_make_request(bio); | |
1626 | } | |
1627 | } | |
1628 | ||
57afd89f N |
1629 | if (sectors_skipped) |
1630 | /* pretend they weren't skipped, it makes | |
1631 | * no important difference in this case | |
1632 | */ | |
1633 | md_done_sync(mddev, sectors_skipped, 1); | |
1634 | ||
1da177e4 LT |
1635 | return sectors_skipped + nr_sectors; |
1636 | giveup: | |
1637 | /* There is nowhere to write, so all non-sync | |
1638 | * drives must be failed, so try the next chunk... | |
1639 | */ | |
1640 | { | |
57afd89f | 1641 | sector_t sec = max_sector - sector_nr; |
1da177e4 LT |
1642 | sectors_skipped += sec; |
1643 | chunks_skipped ++; | |
1644 | sector_nr = max_sector; | |
1da177e4 LT |
1645 | goto skipped; |
1646 | } | |
1647 | } | |
1648 | ||
1649 | static int run(mddev_t *mddev) | |
1650 | { | |
1651 | conf_t *conf; | |
1652 | int i, disk_idx; | |
1653 | mirror_info_t *disk; | |
1654 | mdk_rdev_t *rdev; | |
1655 | struct list_head *tmp; | |
1656 | int nc, fc; | |
1657 | sector_t stride, size; | |
1658 | ||
1659 | if (mddev->level != 10) { | |
1660 | printk(KERN_ERR "raid10: %s: raid level not set correctly... (%d)\n", | |
1661 | mdname(mddev), mddev->level); | |
1662 | goto out; | |
1663 | } | |
1664 | nc = mddev->layout & 255; | |
1665 | fc = (mddev->layout >> 8) & 255; | |
1666 | if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks || | |
1667 | (mddev->layout >> 16)) { | |
1668 | printk(KERN_ERR "raid10: %s: unsupported raid10 layout: 0x%8x\n", | |
1669 | mdname(mddev), mddev->layout); | |
1670 | goto out; | |
1671 | } | |
1672 | /* | |
1673 | * copy the already verified devices into our private RAID10 | |
1674 | * bookkeeping area. [whatever we allocate in run(), | |
1675 | * should be freed in stop()] | |
1676 | */ | |
1677 | conf = kmalloc(sizeof(conf_t), GFP_KERNEL); | |
1678 | mddev->private = conf; | |
1679 | if (!conf) { | |
1680 | printk(KERN_ERR "raid10: couldn't allocate memory for %s\n", | |
1681 | mdname(mddev)); | |
1682 | goto out; | |
1683 | } | |
1684 | memset(conf, 0, sizeof(*conf)); | |
1685 | conf->mirrors = kmalloc(sizeof(struct mirror_info)*mddev->raid_disks, | |
1686 | GFP_KERNEL); | |
1687 | if (!conf->mirrors) { | |
1688 | printk(KERN_ERR "raid10: couldn't allocate memory for %s\n", | |
1689 | mdname(mddev)); | |
1690 | goto out_free_conf; | |
1691 | } | |
1692 | memset(conf->mirrors, 0, sizeof(struct mirror_info)*mddev->raid_disks); | |
1693 | ||
1694 | conf->near_copies = nc; | |
1695 | conf->far_copies = fc; | |
1696 | conf->copies = nc*fc; | |
1697 | conf->chunk_mask = (sector_t)(mddev->chunk_size>>9)-1; | |
1698 | conf->chunk_shift = ffz(~mddev->chunk_size) - 9; | |
1699 | stride = mddev->size >> (conf->chunk_shift-1); | |
1700 | sector_div(stride, fc); | |
1701 | conf->stride = stride << conf->chunk_shift; | |
1702 | ||
1703 | conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc, | |
1704 | r10bio_pool_free, conf); | |
1705 | if (!conf->r10bio_pool) { | |
1706 | printk(KERN_ERR "raid10: couldn't allocate memory for %s\n", | |
1707 | mdname(mddev)); | |
1708 | goto out_free_conf; | |
1709 | } | |
1da177e4 LT |
1710 | |
1711 | ITERATE_RDEV(mddev, rdev, tmp) { | |
1712 | disk_idx = rdev->raid_disk; | |
1713 | if (disk_idx >= mddev->raid_disks | |
1714 | || disk_idx < 0) | |
1715 | continue; | |
1716 | disk = conf->mirrors + disk_idx; | |
1717 | ||
1718 | disk->rdev = rdev; | |
1719 | ||
1720 | blk_queue_stack_limits(mddev->queue, | |
1721 | rdev->bdev->bd_disk->queue); | |
1722 | /* as we don't honour merge_bvec_fn, we must never risk | |
1723 | * violating it, so limit ->max_sector to one PAGE, as | |
1724 | * a one page request is never in violation. | |
1725 | */ | |
1726 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
1727 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) | |
1728 | mddev->queue->max_sectors = (PAGE_SIZE>>9); | |
1729 | ||
1730 | disk->head_position = 0; | |
b2d444d7 | 1731 | if (!test_bit(Faulty, &rdev->flags) && test_bit(In_sync, &rdev->flags)) |
1da177e4 LT |
1732 | conf->working_disks++; |
1733 | } | |
1734 | conf->raid_disks = mddev->raid_disks; | |
1735 | conf->mddev = mddev; | |
1736 | spin_lock_init(&conf->device_lock); | |
1737 | INIT_LIST_HEAD(&conf->retry_list); | |
1738 | ||
1739 | spin_lock_init(&conf->resync_lock); | |
0a27ec96 | 1740 | init_waitqueue_head(&conf->wait_barrier); |
1da177e4 | 1741 | |
6d508242 N |
1742 | /* need to check that every block has at least one working mirror */ |
1743 | if (!enough(conf)) { | |
1744 | printk(KERN_ERR "raid10: not enough operational mirrors for %s\n", | |
1745 | mdname(mddev)); | |
1da177e4 LT |
1746 | goto out_free_conf; |
1747 | } | |
1748 | ||
1749 | mddev->degraded = 0; | |
1750 | for (i = 0; i < conf->raid_disks; i++) { | |
1751 | ||
1752 | disk = conf->mirrors + i; | |
1753 | ||
1754 | if (!disk->rdev) { | |
1755 | disk->head_position = 0; | |
1756 | mddev->degraded++; | |
1757 | } | |
1758 | } | |
1759 | ||
1760 | ||
1761 | mddev->thread = md_register_thread(raid10d, mddev, "%s_raid10"); | |
1762 | if (!mddev->thread) { | |
1763 | printk(KERN_ERR | |
1764 | "raid10: couldn't allocate thread for %s\n", | |
1765 | mdname(mddev)); | |
1766 | goto out_free_conf; | |
1767 | } | |
1768 | ||
1769 | printk(KERN_INFO | |
1770 | "raid10: raid set %s active with %d out of %d devices\n", | |
1771 | mdname(mddev), mddev->raid_disks - mddev->degraded, | |
1772 | mddev->raid_disks); | |
1773 | /* | |
1774 | * Ok, everything is just fine now | |
1775 | */ | |
1776 | size = conf->stride * conf->raid_disks; | |
1777 | sector_div(size, conf->near_copies); | |
1778 | mddev->array_size = size/2; | |
1779 | mddev->resync_max_sectors = size; | |
1780 | ||
7a5febe9 N |
1781 | mddev->queue->unplug_fn = raid10_unplug; |
1782 | mddev->queue->issue_flush_fn = raid10_issue_flush; | |
1783 | ||
1da177e4 LT |
1784 | /* Calculate max read-ahead size. |
1785 | * We need to readahead at least twice a whole stripe.... | |
1786 | * maybe... | |
1787 | */ | |
1788 | { | |
1789 | int stripe = conf->raid_disks * mddev->chunk_size / PAGE_CACHE_SIZE; | |
1790 | stripe /= conf->near_copies; | |
1791 | if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) | |
1792 | mddev->queue->backing_dev_info.ra_pages = 2* stripe; | |
1793 | } | |
1794 | ||
1795 | if (conf->near_copies < mddev->raid_disks) | |
1796 | blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec); | |
1797 | return 0; | |
1798 | ||
1799 | out_free_conf: | |
1800 | if (conf->r10bio_pool) | |
1801 | mempool_destroy(conf->r10bio_pool); | |
990a8baf | 1802 | kfree(conf->mirrors); |
1da177e4 LT |
1803 | kfree(conf); |
1804 | mddev->private = NULL; | |
1805 | out: | |
1806 | return -EIO; | |
1807 | } | |
1808 | ||
1809 | static int stop(mddev_t *mddev) | |
1810 | { | |
1811 | conf_t *conf = mddev_to_conf(mddev); | |
1812 | ||
1813 | md_unregister_thread(mddev->thread); | |
1814 | mddev->thread = NULL; | |
1815 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
1816 | if (conf->r10bio_pool) | |
1817 | mempool_destroy(conf->r10bio_pool); | |
990a8baf | 1818 | kfree(conf->mirrors); |
1da177e4 LT |
1819 | kfree(conf); |
1820 | mddev->private = NULL; | |
1821 | return 0; | |
1822 | } | |
1823 | ||
1824 | ||
1825 | static mdk_personality_t raid10_personality = | |
1826 | { | |
1827 | .name = "raid10", | |
1828 | .owner = THIS_MODULE, | |
1829 | .make_request = make_request, | |
1830 | .run = run, | |
1831 | .stop = stop, | |
1832 | .status = status, | |
1833 | .error_handler = error, | |
1834 | .hot_add_disk = raid10_add_disk, | |
1835 | .hot_remove_disk= raid10_remove_disk, | |
1836 | .spare_active = raid10_spare_active, | |
1837 | .sync_request = sync_request, | |
1838 | }; | |
1839 | ||
1840 | static int __init raid_init(void) | |
1841 | { | |
1842 | return register_md_personality(RAID10, &raid10_personality); | |
1843 | } | |
1844 | ||
1845 | static void raid_exit(void) | |
1846 | { | |
1847 | unregister_md_personality(RAID10); | |
1848 | } | |
1849 | ||
1850 | module_init(raid_init); | |
1851 | module_exit(raid_exit); | |
1852 | MODULE_LICENSE("GPL"); | |
1853 | MODULE_ALIAS("md-personality-9"); /* RAID10 */ |