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