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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 | ||
6cce3b23 | 21 | #include "dm-bio-list.h" |
1da177e4 | 22 | #include <linux/raid/raid10.h> |
6cce3b23 | 23 | #include <linux/raid/bitmap.h> |
1da177e4 LT |
24 | |
25 | /* | |
26 | * RAID10 provides a combination of RAID0 and RAID1 functionality. | |
27 | * The layout of data is defined by | |
28 | * chunk_size | |
29 | * raid_disks | |
30 | * near_copies (stored in low byte of layout) | |
31 | * far_copies (stored in second byte of layout) | |
c93983bf | 32 | * far_offset (stored in bit 16 of layout ) |
1da177e4 LT |
33 | * |
34 | * The data to be stored is divided into chunks using chunksize. | |
35 | * Each device is divided into far_copies sections. | |
36 | * In each section, chunks are laid out in a style similar to raid0, but | |
37 | * near_copies copies of each chunk is stored (each on a different drive). | |
38 | * The starting device for each section is offset near_copies from the starting | |
39 | * device of the previous section. | |
c93983bf | 40 | * Thus they are (near_copies*far_copies) of each chunk, and each is on a different |
1da177e4 LT |
41 | * drive. |
42 | * near_copies and far_copies must be at least one, and their product is at most | |
43 | * raid_disks. | |
c93983bf N |
44 | * |
45 | * If far_offset is true, then the far_copies are handled a bit differently. | |
46 | * The copies are still in different stripes, but instead of be very far apart | |
47 | * on disk, there are adjacent stripes. | |
1da177e4 LT |
48 | */ |
49 | ||
50 | /* | |
51 | * Number of guaranteed r10bios in case of extreme VM load: | |
52 | */ | |
53 | #define NR_RAID10_BIOS 256 | |
54 | ||
55 | static void unplug_slaves(mddev_t *mddev); | |
56 | ||
0a27ec96 N |
57 | static void allow_barrier(conf_t *conf); |
58 | static void lower_barrier(conf_t *conf); | |
59 | ||
dd0fc66f | 60 | static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
61 | { |
62 | conf_t *conf = data; | |
63 | r10bio_t *r10_bio; | |
64 | int size = offsetof(struct r10bio_s, devs[conf->copies]); | |
65 | ||
66 | /* allocate a r10bio with room for raid_disks entries in the bios array */ | |
9ffae0cf N |
67 | r10_bio = kzalloc(size, gfp_flags); |
68 | if (!r10_bio) | |
1da177e4 LT |
69 | unplug_slaves(conf->mddev); |
70 | ||
71 | return r10_bio; | |
72 | } | |
73 | ||
74 | static void r10bio_pool_free(void *r10_bio, void *data) | |
75 | { | |
76 | kfree(r10_bio); | |
77 | } | |
78 | ||
79 | #define RESYNC_BLOCK_SIZE (64*1024) | |
80 | //#define RESYNC_BLOCK_SIZE PAGE_SIZE | |
81 | #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) | |
82 | #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) | |
83 | #define RESYNC_WINDOW (2048*1024) | |
84 | ||
85 | /* | |
86 | * When performing a resync, we need to read and compare, so | |
87 | * we need as many pages are there are copies. | |
88 | * When performing a recovery, we need 2 bios, one for read, | |
89 | * one for write (we recover only one drive per r10buf) | |
90 | * | |
91 | */ | |
dd0fc66f | 92 | static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
93 | { |
94 | conf_t *conf = data; | |
95 | struct page *page; | |
96 | r10bio_t *r10_bio; | |
97 | struct bio *bio; | |
98 | int i, j; | |
99 | int nalloc; | |
100 | ||
101 | r10_bio = r10bio_pool_alloc(gfp_flags, conf); | |
102 | if (!r10_bio) { | |
103 | unplug_slaves(conf->mddev); | |
104 | return NULL; | |
105 | } | |
106 | ||
107 | if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery)) | |
108 | nalloc = conf->copies; /* resync */ | |
109 | else | |
110 | nalloc = 2; /* recovery */ | |
111 | ||
112 | /* | |
113 | * Allocate bios. | |
114 | */ | |
115 | for (j = nalloc ; j-- ; ) { | |
116 | bio = bio_alloc(gfp_flags, RESYNC_PAGES); | |
117 | if (!bio) | |
118 | goto out_free_bio; | |
119 | r10_bio->devs[j].bio = bio; | |
120 | } | |
121 | /* | |
122 | * Allocate RESYNC_PAGES data pages and attach them | |
123 | * where needed. | |
124 | */ | |
125 | for (j = 0 ; j < nalloc; j++) { | |
126 | bio = r10_bio->devs[j].bio; | |
127 | for (i = 0; i < RESYNC_PAGES; i++) { | |
128 | page = alloc_page(gfp_flags); | |
129 | if (unlikely(!page)) | |
130 | goto out_free_pages; | |
131 | ||
132 | bio->bi_io_vec[i].bv_page = page; | |
133 | } | |
134 | } | |
135 | ||
136 | return r10_bio; | |
137 | ||
138 | out_free_pages: | |
139 | for ( ; i > 0 ; i--) | |
1345b1d8 | 140 | safe_put_page(bio->bi_io_vec[i-1].bv_page); |
1da177e4 LT |
141 | while (j--) |
142 | for (i = 0; i < RESYNC_PAGES ; i++) | |
1345b1d8 | 143 | safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page); |
1da177e4 LT |
144 | j = -1; |
145 | out_free_bio: | |
146 | while ( ++j < nalloc ) | |
147 | bio_put(r10_bio->devs[j].bio); | |
148 | r10bio_pool_free(r10_bio, conf); | |
149 | return NULL; | |
150 | } | |
151 | ||
152 | static void r10buf_pool_free(void *__r10_bio, void *data) | |
153 | { | |
154 | int i; | |
155 | conf_t *conf = data; | |
156 | r10bio_t *r10bio = __r10_bio; | |
157 | int j; | |
158 | ||
159 | for (j=0; j < conf->copies; j++) { | |
160 | struct bio *bio = r10bio->devs[j].bio; | |
161 | if (bio) { | |
162 | for (i = 0; i < RESYNC_PAGES; i++) { | |
1345b1d8 | 163 | safe_put_page(bio->bi_io_vec[i].bv_page); |
1da177e4 LT |
164 | bio->bi_io_vec[i].bv_page = NULL; |
165 | } | |
166 | bio_put(bio); | |
167 | } | |
168 | } | |
169 | r10bio_pool_free(r10bio, conf); | |
170 | } | |
171 | ||
172 | static void put_all_bios(conf_t *conf, r10bio_t *r10_bio) | |
173 | { | |
174 | int i; | |
175 | ||
176 | for (i = 0; i < conf->copies; i++) { | |
177 | struct bio **bio = & r10_bio->devs[i].bio; | |
0eb3ff12 | 178 | if (*bio && *bio != IO_BLOCKED) |
1da177e4 LT |
179 | bio_put(*bio); |
180 | *bio = NULL; | |
181 | } | |
182 | } | |
183 | ||
858119e1 | 184 | static void free_r10bio(r10bio_t *r10_bio) |
1da177e4 | 185 | { |
1da177e4 LT |
186 | conf_t *conf = mddev_to_conf(r10_bio->mddev); |
187 | ||
188 | /* | |
189 | * Wake up any possible resync thread that waits for the device | |
190 | * to go idle. | |
191 | */ | |
0a27ec96 | 192 | allow_barrier(conf); |
1da177e4 LT |
193 | |
194 | put_all_bios(conf, r10_bio); | |
195 | mempool_free(r10_bio, conf->r10bio_pool); | |
196 | } | |
197 | ||
858119e1 | 198 | static void put_buf(r10bio_t *r10_bio) |
1da177e4 LT |
199 | { |
200 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
1da177e4 LT |
201 | |
202 | mempool_free(r10_bio, conf->r10buf_pool); | |
203 | ||
0a27ec96 | 204 | lower_barrier(conf); |
1da177e4 LT |
205 | } |
206 | ||
207 | static void reschedule_retry(r10bio_t *r10_bio) | |
208 | { | |
209 | unsigned long flags; | |
210 | mddev_t *mddev = r10_bio->mddev; | |
211 | conf_t *conf = mddev_to_conf(mddev); | |
212 | ||
213 | spin_lock_irqsave(&conf->device_lock, flags); | |
214 | list_add(&r10_bio->retry_list, &conf->retry_list); | |
4443ae10 | 215 | conf->nr_queued ++; |
1da177e4 LT |
216 | spin_unlock_irqrestore(&conf->device_lock, flags); |
217 | ||
218 | md_wakeup_thread(mddev->thread); | |
219 | } | |
220 | ||
221 | /* | |
222 | * raid_end_bio_io() is called when we have finished servicing a mirrored | |
223 | * operation and are ready to return a success/failure code to the buffer | |
224 | * cache layer. | |
225 | */ | |
226 | static void raid_end_bio_io(r10bio_t *r10_bio) | |
227 | { | |
228 | struct bio *bio = r10_bio->master_bio; | |
229 | ||
230 | bio_endio(bio, bio->bi_size, | |
231 | test_bit(R10BIO_Uptodate, &r10_bio->state) ? 0 : -EIO); | |
232 | free_r10bio(r10_bio); | |
233 | } | |
234 | ||
235 | /* | |
236 | * Update disk head position estimator based on IRQ completion info. | |
237 | */ | |
238 | static inline void update_head_pos(int slot, r10bio_t *r10_bio) | |
239 | { | |
240 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
241 | ||
242 | conf->mirrors[r10_bio->devs[slot].devnum].head_position = | |
243 | r10_bio->devs[slot].addr + (r10_bio->sectors); | |
244 | } | |
245 | ||
246 | static int raid10_end_read_request(struct bio *bio, unsigned int bytes_done, int error) | |
247 | { | |
248 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
249 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
250 | int slot, dev; | |
251 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
252 | ||
253 | if (bio->bi_size) | |
254 | return 1; | |
255 | ||
256 | slot = r10_bio->read_slot; | |
257 | dev = r10_bio->devs[slot].devnum; | |
258 | /* | |
259 | * this branch is our 'one mirror IO has finished' event handler: | |
260 | */ | |
4443ae10 N |
261 | update_head_pos(slot, r10_bio); |
262 | ||
263 | if (uptodate) { | |
1da177e4 LT |
264 | /* |
265 | * Set R10BIO_Uptodate in our master bio, so that | |
266 | * we will return a good error code to the higher | |
267 | * levels even if IO on some other mirrored buffer fails. | |
268 | * | |
269 | * The 'master' represents the composite IO operation to | |
270 | * user-side. So if something waits for IO, then it will | |
271 | * wait for the 'master' bio. | |
272 | */ | |
273 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
1da177e4 | 274 | raid_end_bio_io(r10_bio); |
4443ae10 | 275 | } else { |
1da177e4 LT |
276 | /* |
277 | * oops, read error: | |
278 | */ | |
279 | char b[BDEVNAME_SIZE]; | |
280 | if (printk_ratelimit()) | |
281 | printk(KERN_ERR "raid10: %s: rescheduling sector %llu\n", | |
282 | bdevname(conf->mirrors[dev].rdev->bdev,b), (unsigned long long)r10_bio->sector); | |
283 | reschedule_retry(r10_bio); | |
284 | } | |
285 | ||
286 | rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev); | |
287 | return 0; | |
288 | } | |
289 | ||
290 | static int raid10_end_write_request(struct bio *bio, unsigned int bytes_done, int error) | |
291 | { | |
292 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
293 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
294 | int slot, dev; | |
295 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
296 | ||
297 | if (bio->bi_size) | |
298 | return 1; | |
299 | ||
300 | for (slot = 0; slot < conf->copies; slot++) | |
301 | if (r10_bio->devs[slot].bio == bio) | |
302 | break; | |
303 | dev = r10_bio->devs[slot].devnum; | |
304 | ||
305 | /* | |
306 | * this branch is our 'one mirror IO has finished' event handler: | |
307 | */ | |
6cce3b23 | 308 | if (!uptodate) { |
1da177e4 | 309 | md_error(r10_bio->mddev, conf->mirrors[dev].rdev); |
6cce3b23 N |
310 | /* an I/O failed, we can't clear the bitmap */ |
311 | set_bit(R10BIO_Degraded, &r10_bio->state); | |
312 | } else | |
1da177e4 LT |
313 | /* |
314 | * Set R10BIO_Uptodate in our master bio, so that | |
315 | * we will return a good error code for to the higher | |
316 | * levels even if IO on some other mirrored buffer fails. | |
317 | * | |
318 | * The 'master' represents the composite IO operation to | |
319 | * user-side. So if something waits for IO, then it will | |
320 | * wait for the 'master' bio. | |
321 | */ | |
322 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
323 | ||
324 | update_head_pos(slot, r10_bio); | |
325 | ||
326 | /* | |
327 | * | |
328 | * Let's see if all mirrored write operations have finished | |
329 | * already. | |
330 | */ | |
331 | if (atomic_dec_and_test(&r10_bio->remaining)) { | |
6cce3b23 N |
332 | /* clear the bitmap if all writes complete successfully */ |
333 | bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector, | |
334 | r10_bio->sectors, | |
335 | !test_bit(R10BIO_Degraded, &r10_bio->state), | |
336 | 0); | |
1da177e4 LT |
337 | md_write_end(r10_bio->mddev); |
338 | raid_end_bio_io(r10_bio); | |
339 | } | |
340 | ||
341 | rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev); | |
342 | return 0; | |
343 | } | |
344 | ||
345 | ||
346 | /* | |
347 | * RAID10 layout manager | |
348 | * Aswell as the chunksize and raid_disks count, there are two | |
349 | * parameters: near_copies and far_copies. | |
350 | * near_copies * far_copies must be <= raid_disks. | |
351 | * Normally one of these will be 1. | |
352 | * If both are 1, we get raid0. | |
353 | * If near_copies == raid_disks, we get raid1. | |
354 | * | |
355 | * Chunks are layed out in raid0 style with near_copies copies of the | |
356 | * first chunk, followed by near_copies copies of the next chunk and | |
357 | * so on. | |
358 | * If far_copies > 1, then after 1/far_copies of the array has been assigned | |
359 | * as described above, we start again with a device offset of near_copies. | |
360 | * So we effectively have another copy of the whole array further down all | |
361 | * the drives, but with blocks on different drives. | |
362 | * With this layout, and block is never stored twice on the one device. | |
363 | * | |
364 | * raid10_find_phys finds the sector offset of a given virtual sector | |
c93983bf | 365 | * on each device that it is on. |
1da177e4 LT |
366 | * |
367 | * raid10_find_virt does the reverse mapping, from a device and a | |
368 | * sector offset to a virtual address | |
369 | */ | |
370 | ||
371 | static void raid10_find_phys(conf_t *conf, r10bio_t *r10bio) | |
372 | { | |
373 | int n,f; | |
374 | sector_t sector; | |
375 | sector_t chunk; | |
376 | sector_t stripe; | |
377 | int dev; | |
378 | ||
379 | int slot = 0; | |
380 | ||
381 | /* now calculate first sector/dev */ | |
382 | chunk = r10bio->sector >> conf->chunk_shift; | |
383 | sector = r10bio->sector & conf->chunk_mask; | |
384 | ||
385 | chunk *= conf->near_copies; | |
386 | stripe = chunk; | |
387 | dev = sector_div(stripe, conf->raid_disks); | |
c93983bf N |
388 | if (conf->far_offset) |
389 | stripe *= conf->far_copies; | |
1da177e4 LT |
390 | |
391 | sector += stripe << conf->chunk_shift; | |
392 | ||
393 | /* and calculate all the others */ | |
394 | for (n=0; n < conf->near_copies; n++) { | |
395 | int d = dev; | |
396 | sector_t s = sector; | |
397 | r10bio->devs[slot].addr = sector; | |
398 | r10bio->devs[slot].devnum = d; | |
399 | slot++; | |
400 | ||
401 | for (f = 1; f < conf->far_copies; f++) { | |
402 | d += conf->near_copies; | |
403 | if (d >= conf->raid_disks) | |
404 | d -= conf->raid_disks; | |
405 | s += conf->stride; | |
406 | r10bio->devs[slot].devnum = d; | |
407 | r10bio->devs[slot].addr = s; | |
408 | slot++; | |
409 | } | |
410 | dev++; | |
411 | if (dev >= conf->raid_disks) { | |
412 | dev = 0; | |
413 | sector += (conf->chunk_mask + 1); | |
414 | } | |
415 | } | |
416 | BUG_ON(slot != conf->copies); | |
417 | } | |
418 | ||
419 | static sector_t raid10_find_virt(conf_t *conf, sector_t sector, int dev) | |
420 | { | |
421 | sector_t offset, chunk, vchunk; | |
422 | ||
1da177e4 | 423 | offset = sector & conf->chunk_mask; |
c93983bf N |
424 | if (conf->far_offset) { |
425 | int fc; | |
426 | chunk = sector >> conf->chunk_shift; | |
427 | fc = sector_div(chunk, conf->far_copies); | |
428 | dev -= fc * conf->near_copies; | |
429 | if (dev < 0) | |
430 | dev += conf->raid_disks; | |
431 | } else { | |
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 | chunk = sector >> conf->chunk_shift; | |
440 | } | |
1da177e4 LT |
441 | vchunk = chunk * conf->raid_disks + dev; |
442 | sector_div(vchunk, conf->near_copies); | |
443 | return (vchunk << conf->chunk_shift) + offset; | |
444 | } | |
445 | ||
446 | /** | |
447 | * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged | |
448 | * @q: request queue | |
449 | * @bio: the buffer head that's been built up so far | |
450 | * @biovec: the request that could be merged to it. | |
451 | * | |
452 | * Return amount of bytes we can accept at this offset | |
453 | * If near_copies == raid_disk, there are no striping issues, | |
454 | * but in that case, the function isn't called at all. | |
455 | */ | |
456 | static int raid10_mergeable_bvec(request_queue_t *q, struct bio *bio, | |
457 | struct bio_vec *bio_vec) | |
458 | { | |
459 | mddev_t *mddev = q->queuedata; | |
460 | sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); | |
461 | int max; | |
462 | unsigned int chunk_sectors = mddev->chunk_size >> 9; | |
463 | unsigned int bio_sectors = bio->bi_size >> 9; | |
464 | ||
465 | max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; | |
466 | if (max < 0) max = 0; /* bio_add cannot handle a negative return */ | |
467 | if (max <= bio_vec->bv_len && bio_sectors == 0) | |
468 | return bio_vec->bv_len; | |
469 | else | |
470 | return max; | |
471 | } | |
472 | ||
473 | /* | |
474 | * This routine returns the disk from which the requested read should | |
475 | * be done. There is a per-array 'next expected sequential IO' sector | |
476 | * number - if this matches on the next IO then we use the last disk. | |
477 | * There is also a per-disk 'last know head position' sector that is | |
478 | * maintained from IRQ contexts, both the normal and the resync IO | |
479 | * completion handlers update this position correctly. If there is no | |
480 | * perfect sequential match then we pick the disk whose head is closest. | |
481 | * | |
482 | * If there are 2 mirrors in the same 2 devices, performance degrades | |
483 | * because position is mirror, not device based. | |
484 | * | |
485 | * The rdev for the device selected will have nr_pending incremented. | |
486 | */ | |
487 | ||
488 | /* | |
489 | * FIXME: possibly should rethink readbalancing and do it differently | |
490 | * depending on near_copies / far_copies geometry. | |
491 | */ | |
492 | static int read_balance(conf_t *conf, r10bio_t *r10_bio) | |
493 | { | |
494 | const unsigned long this_sector = r10_bio->sector; | |
495 | int disk, slot, nslot; | |
496 | const int sectors = r10_bio->sectors; | |
497 | sector_t new_distance, current_distance; | |
d6065f7b | 498 | mdk_rdev_t *rdev; |
1da177e4 LT |
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 | |
6cce3b23 N |
504 | * device if no resync is going on (recovery is ok), or below |
505 | * the resync window. We take the first readable disk when | |
506 | * above the resync window. | |
1da177e4 LT |
507 | */ |
508 | if (conf->mddev->recovery_cp < MaxSector | |
509 | && (this_sector + sectors >= conf->next_resync)) { | |
510 | /* make sure that disk is operational */ | |
511 | slot = 0; | |
512 | disk = r10_bio->devs[slot].devnum; | |
513 | ||
d6065f7b | 514 | while ((rdev = rcu_dereference(conf->mirrors[disk].rdev)) == NULL || |
0eb3ff12 | 515 | r10_bio->devs[slot].bio == IO_BLOCKED || |
b2d444d7 | 516 | !test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
517 | slot++; |
518 | if (slot == conf->copies) { | |
519 | slot = 0; | |
520 | disk = -1; | |
521 | break; | |
522 | } | |
523 | disk = r10_bio->devs[slot].devnum; | |
524 | } | |
525 | goto rb_out; | |
526 | } | |
527 | ||
528 | ||
529 | /* make sure the disk is operational */ | |
530 | slot = 0; | |
531 | disk = r10_bio->devs[slot].devnum; | |
d6065f7b | 532 | while ((rdev=rcu_dereference(conf->mirrors[disk].rdev)) == NULL || |
0eb3ff12 | 533 | r10_bio->devs[slot].bio == IO_BLOCKED || |
b2d444d7 | 534 | !test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
535 | slot ++; |
536 | if (slot == conf->copies) { | |
537 | disk = -1; | |
538 | goto rb_out; | |
539 | } | |
540 | disk = r10_bio->devs[slot].devnum; | |
541 | } | |
542 | ||
543 | ||
3ec67ac1 N |
544 | current_distance = abs(r10_bio->devs[slot].addr - |
545 | conf->mirrors[disk].head_position); | |
1da177e4 LT |
546 | |
547 | /* Find the disk whose head is closest */ | |
548 | ||
549 | for (nslot = slot; nslot < conf->copies; nslot++) { | |
550 | int ndisk = r10_bio->devs[nslot].devnum; | |
551 | ||
552 | ||
d6065f7b | 553 | if ((rdev=rcu_dereference(conf->mirrors[ndisk].rdev)) == NULL || |
0eb3ff12 | 554 | r10_bio->devs[nslot].bio == IO_BLOCKED || |
b2d444d7 | 555 | !test_bit(In_sync, &rdev->flags)) |
1da177e4 LT |
556 | continue; |
557 | ||
22dfdf52 N |
558 | /* This optimisation is debatable, and completely destroys |
559 | * sequential read speed for 'far copies' arrays. So only | |
560 | * keep it for 'near' arrays, and review those later. | |
561 | */ | |
562 | if (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) { | |
1da177e4 LT |
563 | disk = ndisk; |
564 | slot = nslot; | |
565 | break; | |
566 | } | |
567 | new_distance = abs(r10_bio->devs[nslot].addr - | |
568 | conf->mirrors[ndisk].head_position); | |
569 | if (new_distance < current_distance) { | |
570 | current_distance = new_distance; | |
571 | disk = ndisk; | |
572 | slot = nslot; | |
573 | } | |
574 | } | |
575 | ||
576 | rb_out: | |
577 | r10_bio->read_slot = slot; | |
578 | /* conf->next_seq_sect = this_sector + sectors;*/ | |
579 | ||
d6065f7b | 580 | if (disk >= 0 && (rdev=rcu_dereference(conf->mirrors[disk].rdev))!= NULL) |
1da177e4 | 581 | atomic_inc(&conf->mirrors[disk].rdev->nr_pending); |
29fc7e3e N |
582 | else |
583 | disk = -1; | |
1da177e4 LT |
584 | rcu_read_unlock(); |
585 | ||
586 | return disk; | |
587 | } | |
588 | ||
589 | static void unplug_slaves(mddev_t *mddev) | |
590 | { | |
591 | conf_t *conf = mddev_to_conf(mddev); | |
592 | int i; | |
593 | ||
594 | rcu_read_lock(); | |
595 | for (i=0; i<mddev->raid_disks; i++) { | |
d6065f7b | 596 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); |
b2d444d7 | 597 | if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { |
1da177e4 LT |
598 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); |
599 | ||
600 | atomic_inc(&rdev->nr_pending); | |
601 | rcu_read_unlock(); | |
602 | ||
603 | if (r_queue->unplug_fn) | |
604 | r_queue->unplug_fn(r_queue); | |
605 | ||
606 | rdev_dec_pending(rdev, mddev); | |
607 | rcu_read_lock(); | |
608 | } | |
609 | } | |
610 | rcu_read_unlock(); | |
611 | } | |
612 | ||
613 | static void raid10_unplug(request_queue_t *q) | |
614 | { | |
6cce3b23 N |
615 | mddev_t *mddev = q->queuedata; |
616 | ||
1da177e4 | 617 | unplug_slaves(q->queuedata); |
6cce3b23 | 618 | md_wakeup_thread(mddev->thread); |
1da177e4 LT |
619 | } |
620 | ||
621 | static int raid10_issue_flush(request_queue_t *q, struct gendisk *disk, | |
622 | sector_t *error_sector) | |
623 | { | |
624 | mddev_t *mddev = q->queuedata; | |
625 | conf_t *conf = mddev_to_conf(mddev); | |
626 | int i, ret = 0; | |
627 | ||
628 | rcu_read_lock(); | |
629 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { | |
d6065f7b | 630 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); |
b2d444d7 | 631 | if (rdev && !test_bit(Faulty, &rdev->flags)) { |
1da177e4 LT |
632 | struct block_device *bdev = rdev->bdev; |
633 | request_queue_t *r_queue = bdev_get_queue(bdev); | |
634 | ||
635 | if (!r_queue->issue_flush_fn) | |
636 | ret = -EOPNOTSUPP; | |
637 | else { | |
638 | atomic_inc(&rdev->nr_pending); | |
639 | rcu_read_unlock(); | |
640 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, | |
641 | error_sector); | |
642 | rdev_dec_pending(rdev, mddev); | |
643 | rcu_read_lock(); | |
644 | } | |
645 | } | |
646 | } | |
647 | rcu_read_unlock(); | |
648 | return ret; | |
649 | } | |
650 | ||
0a27ec96 N |
651 | /* Barriers.... |
652 | * Sometimes we need to suspend IO while we do something else, | |
653 | * either some resync/recovery, or reconfigure the array. | |
654 | * To do this we raise a 'barrier'. | |
655 | * The 'barrier' is a counter that can be raised multiple times | |
656 | * to count how many activities are happening which preclude | |
657 | * normal IO. | |
658 | * We can only raise the barrier if there is no pending IO. | |
659 | * i.e. if nr_pending == 0. | |
660 | * We choose only to raise the barrier if no-one is waiting for the | |
661 | * barrier to go down. This means that as soon as an IO request | |
662 | * is ready, no other operations which require a barrier will start | |
663 | * until the IO request has had a chance. | |
664 | * | |
665 | * So: regular IO calls 'wait_barrier'. When that returns there | |
666 | * is no backgroup IO happening, It must arrange to call | |
667 | * allow_barrier when it has finished its IO. | |
668 | * backgroup IO calls must call raise_barrier. Once that returns | |
669 | * there is no normal IO happeing. It must arrange to call | |
670 | * lower_barrier when the particular background IO completes. | |
1da177e4 LT |
671 | */ |
672 | #define RESYNC_DEPTH 32 | |
673 | ||
6cce3b23 | 674 | static void raise_barrier(conf_t *conf, int force) |
1da177e4 | 675 | { |
6cce3b23 | 676 | BUG_ON(force && !conf->barrier); |
1da177e4 | 677 | spin_lock_irq(&conf->resync_lock); |
0a27ec96 | 678 | |
6cce3b23 N |
679 | /* Wait until no block IO is waiting (unless 'force') */ |
680 | wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting, | |
0a27ec96 N |
681 | conf->resync_lock, |
682 | raid10_unplug(conf->mddev->queue)); | |
683 | ||
684 | /* block any new IO from starting */ | |
685 | conf->barrier++; | |
686 | ||
687 | /* No wait for all pending IO to complete */ | |
688 | wait_event_lock_irq(conf->wait_barrier, | |
689 | !conf->nr_pending && conf->barrier < RESYNC_DEPTH, | |
690 | conf->resync_lock, | |
691 | raid10_unplug(conf->mddev->queue)); | |
692 | ||
693 | spin_unlock_irq(&conf->resync_lock); | |
694 | } | |
695 | ||
696 | static void lower_barrier(conf_t *conf) | |
697 | { | |
698 | unsigned long flags; | |
699 | spin_lock_irqsave(&conf->resync_lock, flags); | |
700 | conf->barrier--; | |
701 | spin_unlock_irqrestore(&conf->resync_lock, flags); | |
702 | wake_up(&conf->wait_barrier); | |
703 | } | |
704 | ||
705 | static void wait_barrier(conf_t *conf) | |
706 | { | |
707 | spin_lock_irq(&conf->resync_lock); | |
708 | if (conf->barrier) { | |
709 | conf->nr_waiting++; | |
710 | wait_event_lock_irq(conf->wait_barrier, !conf->barrier, | |
711 | conf->resync_lock, | |
712 | raid10_unplug(conf->mddev->queue)); | |
713 | conf->nr_waiting--; | |
1da177e4 | 714 | } |
0a27ec96 | 715 | conf->nr_pending++; |
1da177e4 LT |
716 | spin_unlock_irq(&conf->resync_lock); |
717 | } | |
718 | ||
0a27ec96 N |
719 | static void allow_barrier(conf_t *conf) |
720 | { | |
721 | unsigned long flags; | |
722 | spin_lock_irqsave(&conf->resync_lock, flags); | |
723 | conf->nr_pending--; | |
724 | spin_unlock_irqrestore(&conf->resync_lock, flags); | |
725 | wake_up(&conf->wait_barrier); | |
726 | } | |
727 | ||
4443ae10 N |
728 | static void freeze_array(conf_t *conf) |
729 | { | |
730 | /* stop syncio and normal IO and wait for everything to | |
f188593e | 731 | * go quiet. |
4443ae10 N |
732 | * We increment barrier and nr_waiting, and then |
733 | * wait until barrier+nr_pending match nr_queued+2 | |
734 | */ | |
735 | spin_lock_irq(&conf->resync_lock); | |
736 | conf->barrier++; | |
737 | conf->nr_waiting++; | |
738 | wait_event_lock_irq(conf->wait_barrier, | |
739 | conf->barrier+conf->nr_pending == conf->nr_queued+2, | |
740 | conf->resync_lock, | |
741 | raid10_unplug(conf->mddev->queue)); | |
742 | spin_unlock_irq(&conf->resync_lock); | |
743 | } | |
744 | ||
745 | static void unfreeze_array(conf_t *conf) | |
746 | { | |
747 | /* reverse the effect of the freeze */ | |
748 | spin_lock_irq(&conf->resync_lock); | |
749 | conf->barrier--; | |
750 | conf->nr_waiting--; | |
751 | wake_up(&conf->wait_barrier); | |
752 | spin_unlock_irq(&conf->resync_lock); | |
753 | } | |
754 | ||
1da177e4 LT |
755 | static int make_request(request_queue_t *q, struct bio * bio) |
756 | { | |
757 | mddev_t *mddev = q->queuedata; | |
758 | conf_t *conf = mddev_to_conf(mddev); | |
759 | mirror_info_t *mirror; | |
760 | r10bio_t *r10_bio; | |
761 | struct bio *read_bio; | |
762 | int i; | |
763 | int chunk_sects = conf->chunk_mask + 1; | |
a362357b | 764 | const int rw = bio_data_dir(bio); |
6cce3b23 N |
765 | struct bio_list bl; |
766 | unsigned long flags; | |
1da177e4 | 767 | |
e5dcdd80 N |
768 | if (unlikely(bio_barrier(bio))) { |
769 | bio_endio(bio, bio->bi_size, -EOPNOTSUPP); | |
770 | return 0; | |
771 | } | |
772 | ||
1da177e4 LT |
773 | /* If this request crosses a chunk boundary, we need to |
774 | * split it. This will only happen for 1 PAGE (or less) requests. | |
775 | */ | |
776 | if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9) | |
777 | > chunk_sects && | |
778 | conf->near_copies < conf->raid_disks)) { | |
779 | struct bio_pair *bp; | |
780 | /* Sanity check -- queue functions should prevent this happening */ | |
781 | if (bio->bi_vcnt != 1 || | |
782 | bio->bi_idx != 0) | |
783 | goto bad_map; | |
784 | /* This is a one page bio that upper layers | |
785 | * refuse to split for us, so we need to split it. | |
786 | */ | |
787 | bp = bio_split(bio, bio_split_pool, | |
788 | chunk_sects - (bio->bi_sector & (chunk_sects - 1)) ); | |
789 | if (make_request(q, &bp->bio1)) | |
790 | generic_make_request(&bp->bio1); | |
791 | if (make_request(q, &bp->bio2)) | |
792 | generic_make_request(&bp->bio2); | |
793 | ||
794 | bio_pair_release(bp); | |
795 | return 0; | |
796 | bad_map: | |
797 | printk("raid10_make_request bug: can't convert block across chunks" | |
798 | " or bigger than %dk %llu %d\n", chunk_sects/2, | |
799 | (unsigned long long)bio->bi_sector, bio->bi_size >> 10); | |
800 | ||
801 | bio_io_error(bio, bio->bi_size); | |
802 | return 0; | |
803 | } | |
804 | ||
3d310eb7 | 805 | md_write_start(mddev, bio); |
06d91a5f | 806 | |
1da177e4 LT |
807 | /* |
808 | * Register the new request and wait if the reconstruction | |
809 | * thread has put up a bar for new requests. | |
810 | * Continue immediately if no resync is active currently. | |
811 | */ | |
0a27ec96 | 812 | wait_barrier(conf); |
1da177e4 | 813 | |
a362357b JA |
814 | disk_stat_inc(mddev->gendisk, ios[rw]); |
815 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio)); | |
1da177e4 LT |
816 | |
817 | r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO); | |
818 | ||
819 | r10_bio->master_bio = bio; | |
820 | r10_bio->sectors = bio->bi_size >> 9; | |
821 | ||
822 | r10_bio->mddev = mddev; | |
823 | r10_bio->sector = bio->bi_sector; | |
6cce3b23 | 824 | r10_bio->state = 0; |
1da177e4 | 825 | |
a362357b | 826 | if (rw == READ) { |
1da177e4 LT |
827 | /* |
828 | * read balancing logic: | |
829 | */ | |
830 | int disk = read_balance(conf, r10_bio); | |
831 | int slot = r10_bio->read_slot; | |
832 | if (disk < 0) { | |
833 | raid_end_bio_io(r10_bio); | |
834 | return 0; | |
835 | } | |
836 | mirror = conf->mirrors + disk; | |
837 | ||
838 | read_bio = bio_clone(bio, GFP_NOIO); | |
839 | ||
840 | r10_bio->devs[slot].bio = read_bio; | |
841 | ||
842 | read_bio->bi_sector = r10_bio->devs[slot].addr + | |
843 | mirror->rdev->data_offset; | |
844 | read_bio->bi_bdev = mirror->rdev->bdev; | |
845 | read_bio->bi_end_io = raid10_end_read_request; | |
846 | read_bio->bi_rw = READ; | |
847 | read_bio->bi_private = r10_bio; | |
848 | ||
849 | generic_make_request(read_bio); | |
850 | return 0; | |
851 | } | |
852 | ||
853 | /* | |
854 | * WRITE: | |
855 | */ | |
856 | /* first select target devices under spinlock and | |
857 | * inc refcount on their rdev. Record them by setting | |
858 | * bios[x] to bio | |
859 | */ | |
860 | raid10_find_phys(conf, r10_bio); | |
861 | rcu_read_lock(); | |
862 | for (i = 0; i < conf->copies; i++) { | |
863 | int d = r10_bio->devs[i].devnum; | |
d6065f7b SW |
864 | mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev); |
865 | if (rdev && | |
b2d444d7 | 866 | !test_bit(Faulty, &rdev->flags)) { |
d6065f7b | 867 | atomic_inc(&rdev->nr_pending); |
1da177e4 | 868 | r10_bio->devs[i].bio = bio; |
6cce3b23 | 869 | } else { |
1da177e4 | 870 | r10_bio->devs[i].bio = NULL; |
6cce3b23 N |
871 | set_bit(R10BIO_Degraded, &r10_bio->state); |
872 | } | |
1da177e4 LT |
873 | } |
874 | rcu_read_unlock(); | |
875 | ||
6cce3b23 | 876 | atomic_set(&r10_bio->remaining, 0); |
06d91a5f | 877 | |
6cce3b23 | 878 | bio_list_init(&bl); |
1da177e4 LT |
879 | for (i = 0; i < conf->copies; i++) { |
880 | struct bio *mbio; | |
881 | int d = r10_bio->devs[i].devnum; | |
882 | if (!r10_bio->devs[i].bio) | |
883 | continue; | |
884 | ||
885 | mbio = bio_clone(bio, GFP_NOIO); | |
886 | r10_bio->devs[i].bio = mbio; | |
887 | ||
888 | mbio->bi_sector = r10_bio->devs[i].addr+ | |
889 | conf->mirrors[d].rdev->data_offset; | |
890 | mbio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
891 | mbio->bi_end_io = raid10_end_write_request; | |
892 | mbio->bi_rw = WRITE; | |
893 | mbio->bi_private = r10_bio; | |
894 | ||
895 | atomic_inc(&r10_bio->remaining); | |
6cce3b23 | 896 | bio_list_add(&bl, mbio); |
1da177e4 LT |
897 | } |
898 | ||
6cce3b23 N |
899 | bitmap_startwrite(mddev->bitmap, bio->bi_sector, r10_bio->sectors, 0); |
900 | spin_lock_irqsave(&conf->device_lock, flags); | |
901 | bio_list_merge(&conf->pending_bio_list, &bl); | |
902 | blk_plug_device(mddev->queue); | |
903 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1da177e4 LT |
904 | |
905 | return 0; | |
906 | } | |
907 | ||
908 | static void status(struct seq_file *seq, mddev_t *mddev) | |
909 | { | |
910 | conf_t *conf = mddev_to_conf(mddev); | |
911 | int i; | |
912 | ||
913 | if (conf->near_copies < conf->raid_disks) | |
914 | seq_printf(seq, " %dK chunks", mddev->chunk_size/1024); | |
915 | if (conf->near_copies > 1) | |
916 | seq_printf(seq, " %d near-copies", conf->near_copies); | |
c93983bf N |
917 | if (conf->far_copies > 1) { |
918 | if (conf->far_offset) | |
919 | seq_printf(seq, " %d offset-copies", conf->far_copies); | |
920 | else | |
921 | seq_printf(seq, " %d far-copies", conf->far_copies); | |
922 | } | |
1da177e4 LT |
923 | seq_printf(seq, " [%d/%d] [", conf->raid_disks, |
924 | conf->working_disks); | |
925 | for (i = 0; i < conf->raid_disks; i++) | |
926 | seq_printf(seq, "%s", | |
927 | conf->mirrors[i].rdev && | |
b2d444d7 | 928 | test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
929 | seq_printf(seq, "]"); |
930 | } | |
931 | ||
932 | static void error(mddev_t *mddev, mdk_rdev_t *rdev) | |
933 | { | |
934 | char b[BDEVNAME_SIZE]; | |
935 | conf_t *conf = mddev_to_conf(mddev); | |
936 | ||
937 | /* | |
938 | * If it is not operational, then we have already marked it as dead | |
939 | * else if it is the last working disks, ignore the error, let the | |
940 | * next level up know. | |
941 | * else mark the drive as failed | |
942 | */ | |
b2d444d7 | 943 | if (test_bit(In_sync, &rdev->flags) |
1da177e4 LT |
944 | && conf->working_disks == 1) |
945 | /* | |
946 | * Don't fail the drive, just return an IO error. | |
947 | * The test should really be more sophisticated than | |
948 | * "working_disks == 1", but it isn't critical, and | |
949 | * can wait until we do more sophisticated "is the drive | |
950 | * really dead" tests... | |
951 | */ | |
952 | return; | |
b2d444d7 | 953 | if (test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
954 | mddev->degraded++; |
955 | conf->working_disks--; | |
956 | /* | |
957 | * if recovery is running, make sure it aborts. | |
958 | */ | |
959 | set_bit(MD_RECOVERY_ERR, &mddev->recovery); | |
960 | } | |
b2d444d7 N |
961 | clear_bit(In_sync, &rdev->flags); |
962 | set_bit(Faulty, &rdev->flags); | |
1da177e4 LT |
963 | mddev->sb_dirty = 1; |
964 | printk(KERN_ALERT "raid10: Disk failure on %s, disabling device. \n" | |
965 | " Operation continuing on %d devices\n", | |
966 | bdevname(rdev->bdev,b), conf->working_disks); | |
967 | } | |
968 | ||
969 | static void print_conf(conf_t *conf) | |
970 | { | |
971 | int i; | |
972 | mirror_info_t *tmp; | |
973 | ||
974 | printk("RAID10 conf printout:\n"); | |
975 | if (!conf) { | |
976 | printk("(!conf)\n"); | |
977 | return; | |
978 | } | |
979 | printk(" --- wd:%d rd:%d\n", conf->working_disks, | |
980 | conf->raid_disks); | |
981 | ||
982 | for (i = 0; i < conf->raid_disks; i++) { | |
983 | char b[BDEVNAME_SIZE]; | |
984 | tmp = conf->mirrors + i; | |
985 | if (tmp->rdev) | |
986 | printk(" disk %d, wo:%d, o:%d, dev:%s\n", | |
b2d444d7 N |
987 | i, !test_bit(In_sync, &tmp->rdev->flags), |
988 | !test_bit(Faulty, &tmp->rdev->flags), | |
1da177e4 LT |
989 | bdevname(tmp->rdev->bdev,b)); |
990 | } | |
991 | } | |
992 | ||
993 | static void close_sync(conf_t *conf) | |
994 | { | |
0a27ec96 N |
995 | wait_barrier(conf); |
996 | allow_barrier(conf); | |
1da177e4 LT |
997 | |
998 | mempool_destroy(conf->r10buf_pool); | |
999 | conf->r10buf_pool = NULL; | |
1000 | } | |
1001 | ||
6d508242 N |
1002 | /* check if there are enough drives for |
1003 | * every block to appear on atleast one | |
1004 | */ | |
1005 | static int enough(conf_t *conf) | |
1006 | { | |
1007 | int first = 0; | |
1008 | ||
1009 | do { | |
1010 | int n = conf->copies; | |
1011 | int cnt = 0; | |
1012 | while (n--) { | |
1013 | if (conf->mirrors[first].rdev) | |
1014 | cnt++; | |
1015 | first = (first+1) % conf->raid_disks; | |
1016 | } | |
1017 | if (cnt == 0) | |
1018 | return 0; | |
1019 | } while (first != 0); | |
1020 | return 1; | |
1021 | } | |
1022 | ||
1da177e4 LT |
1023 | static int raid10_spare_active(mddev_t *mddev) |
1024 | { | |
1025 | int i; | |
1026 | conf_t *conf = mddev->private; | |
1027 | mirror_info_t *tmp; | |
1028 | ||
1029 | /* | |
1030 | * Find all non-in_sync disks within the RAID10 configuration | |
1031 | * and mark them in_sync | |
1032 | */ | |
1033 | for (i = 0; i < conf->raid_disks; i++) { | |
1034 | tmp = conf->mirrors + i; | |
1035 | if (tmp->rdev | |
b2d444d7 N |
1036 | && !test_bit(Faulty, &tmp->rdev->flags) |
1037 | && !test_bit(In_sync, &tmp->rdev->flags)) { | |
1da177e4 LT |
1038 | conf->working_disks++; |
1039 | mddev->degraded--; | |
b2d444d7 | 1040 | set_bit(In_sync, &tmp->rdev->flags); |
1da177e4 LT |
1041 | } |
1042 | } | |
1043 | ||
1044 | print_conf(conf); | |
1045 | return 0; | |
1046 | } | |
1047 | ||
1048 | ||
1049 | static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
1050 | { | |
1051 | conf_t *conf = mddev->private; | |
1052 | int found = 0; | |
1053 | int mirror; | |
1054 | mirror_info_t *p; | |
1055 | ||
1056 | if (mddev->recovery_cp < MaxSector) | |
1057 | /* only hot-add to in-sync arrays, as recovery is | |
1058 | * very different from resync | |
1059 | */ | |
1060 | return 0; | |
6d508242 N |
1061 | if (!enough(conf)) |
1062 | return 0; | |
1da177e4 | 1063 | |
6cce3b23 N |
1064 | if (rdev->saved_raid_disk >= 0 && |
1065 | conf->mirrors[rdev->saved_raid_disk].rdev == NULL) | |
1066 | mirror = rdev->saved_raid_disk; | |
1067 | else | |
1068 | mirror = 0; | |
1069 | for ( ; mirror < mddev->raid_disks; mirror++) | |
1da177e4 LT |
1070 | if ( !(p=conf->mirrors+mirror)->rdev) { |
1071 | ||
1072 | blk_queue_stack_limits(mddev->queue, | |
1073 | rdev->bdev->bd_disk->queue); | |
1074 | /* as we don't honour merge_bvec_fn, we must never risk | |
1075 | * violating it, so limit ->max_sector to one PAGE, as | |
1076 | * a one page request is never in violation. | |
1077 | */ | |
1078 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
1079 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) | |
1080 | mddev->queue->max_sectors = (PAGE_SIZE>>9); | |
1081 | ||
1082 | p->head_position = 0; | |
1083 | rdev->raid_disk = mirror; | |
1084 | found = 1; | |
6cce3b23 N |
1085 | if (rdev->saved_raid_disk != mirror) |
1086 | conf->fullsync = 1; | |
d6065f7b | 1087 | rcu_assign_pointer(p->rdev, rdev); |
1da177e4 LT |
1088 | break; |
1089 | } | |
1090 | ||
1091 | print_conf(conf); | |
1092 | return found; | |
1093 | } | |
1094 | ||
1095 | static int raid10_remove_disk(mddev_t *mddev, int number) | |
1096 | { | |
1097 | conf_t *conf = mddev->private; | |
1098 | int err = 0; | |
1099 | mdk_rdev_t *rdev; | |
1100 | mirror_info_t *p = conf->mirrors+ number; | |
1101 | ||
1102 | print_conf(conf); | |
1103 | rdev = p->rdev; | |
1104 | if (rdev) { | |
b2d444d7 | 1105 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 LT |
1106 | atomic_read(&rdev->nr_pending)) { |
1107 | err = -EBUSY; | |
1108 | goto abort; | |
1109 | } | |
1110 | p->rdev = NULL; | |
fbd568a3 | 1111 | synchronize_rcu(); |
1da177e4 LT |
1112 | if (atomic_read(&rdev->nr_pending)) { |
1113 | /* lost the race, try later */ | |
1114 | err = -EBUSY; | |
1115 | p->rdev = rdev; | |
1116 | } | |
1117 | } | |
1118 | abort: | |
1119 | ||
1120 | print_conf(conf); | |
1121 | return err; | |
1122 | } | |
1123 | ||
1124 | ||
1125 | static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error) | |
1126 | { | |
1da177e4 LT |
1127 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); |
1128 | conf_t *conf = mddev_to_conf(r10_bio->mddev); | |
1129 | int i,d; | |
1130 | ||
1131 | if (bio->bi_size) | |
1132 | return 1; | |
1133 | ||
1134 | for (i=0; i<conf->copies; i++) | |
1135 | if (r10_bio->devs[i].bio == bio) | |
1136 | break; | |
b6385483 | 1137 | BUG_ON(i == conf->copies); |
1da177e4 LT |
1138 | update_head_pos(i, r10_bio); |
1139 | d = r10_bio->devs[i].devnum; | |
0eb3ff12 N |
1140 | |
1141 | if (test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
1142 | set_bit(R10BIO_Uptodate, &r10_bio->state); | |
4dbcdc75 N |
1143 | else { |
1144 | atomic_add(r10_bio->sectors, | |
1145 | &conf->mirrors[d].rdev->corrected_errors); | |
1146 | if (!test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery)) | |
1147 | md_error(r10_bio->mddev, | |
1148 | conf->mirrors[d].rdev); | |
1149 | } | |
1da177e4 LT |
1150 | |
1151 | /* for reconstruct, we always reschedule after a read. | |
1152 | * for resync, only after all reads | |
1153 | */ | |
1154 | if (test_bit(R10BIO_IsRecover, &r10_bio->state) || | |
1155 | atomic_dec_and_test(&r10_bio->remaining)) { | |
1156 | /* we have read all the blocks, | |
1157 | * do the comparison in process context in raid10d | |
1158 | */ | |
1159 | reschedule_retry(r10_bio); | |
1160 | } | |
1161 | rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev); | |
1162 | return 0; | |
1163 | } | |
1164 | ||
1165 | static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error) | |
1166 | { | |
1167 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
1168 | r10bio_t * r10_bio = (r10bio_t *)(bio->bi_private); | |
1169 | mddev_t *mddev = r10_bio->mddev; | |
1170 | conf_t *conf = mddev_to_conf(mddev); | |
1171 | int i,d; | |
1172 | ||
1173 | if (bio->bi_size) | |
1174 | return 1; | |
1175 | ||
1176 | for (i = 0; i < conf->copies; i++) | |
1177 | if (r10_bio->devs[i].bio == bio) | |
1178 | break; | |
1179 | d = r10_bio->devs[i].devnum; | |
1180 | ||
1181 | if (!uptodate) | |
1182 | md_error(mddev, conf->mirrors[d].rdev); | |
1183 | update_head_pos(i, r10_bio); | |
1184 | ||
1185 | while (atomic_dec_and_test(&r10_bio->remaining)) { | |
1186 | if (r10_bio->master_bio == NULL) { | |
1187 | /* the primary of several recovery bios */ | |
1188 | md_done_sync(mddev, r10_bio->sectors, 1); | |
1189 | put_buf(r10_bio); | |
1190 | break; | |
1191 | } else { | |
1192 | r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio; | |
1193 | put_buf(r10_bio); | |
1194 | r10_bio = r10_bio2; | |
1195 | } | |
1196 | } | |
1197 | rdev_dec_pending(conf->mirrors[d].rdev, mddev); | |
1198 | return 0; | |
1199 | } | |
1200 | ||
1201 | /* | |
1202 | * Note: sync and recover and handled very differently for raid10 | |
1203 | * This code is for resync. | |
1204 | * For resync, we read through virtual addresses and read all blocks. | |
1205 | * If there is any error, we schedule a write. The lowest numbered | |
1206 | * drive is authoritative. | |
1207 | * However requests come for physical address, so we need to map. | |
1208 | * For every physical address there are raid_disks/copies virtual addresses, | |
1209 | * which is always are least one, but is not necessarly an integer. | |
1210 | * This means that a physical address can span multiple chunks, so we may | |
1211 | * have to submit multiple io requests for a single sync request. | |
1212 | */ | |
1213 | /* | |
1214 | * We check if all blocks are in-sync and only write to blocks that | |
1215 | * aren't in sync | |
1216 | */ | |
1217 | static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio) | |
1218 | { | |
1219 | conf_t *conf = mddev_to_conf(mddev); | |
1220 | int i, first; | |
1221 | struct bio *tbio, *fbio; | |
1222 | ||
1223 | atomic_set(&r10_bio->remaining, 1); | |
1224 | ||
1225 | /* find the first device with a block */ | |
1226 | for (i=0; i<conf->copies; i++) | |
1227 | if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) | |
1228 | break; | |
1229 | ||
1230 | if (i == conf->copies) | |
1231 | goto done; | |
1232 | ||
1233 | first = i; | |
1234 | fbio = r10_bio->devs[i].bio; | |
1235 | ||
1236 | /* now find blocks with errors */ | |
0eb3ff12 N |
1237 | for (i=0 ; i < conf->copies ; i++) { |
1238 | int j, d; | |
1239 | int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9); | |
1da177e4 | 1240 | |
1da177e4 | 1241 | tbio = r10_bio->devs[i].bio; |
0eb3ff12 N |
1242 | |
1243 | if (tbio->bi_end_io != end_sync_read) | |
1244 | continue; | |
1245 | if (i == first) | |
1da177e4 | 1246 | continue; |
0eb3ff12 N |
1247 | if (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) { |
1248 | /* We know that the bi_io_vec layout is the same for | |
1249 | * both 'first' and 'i', so we just compare them. | |
1250 | * All vec entries are PAGE_SIZE; | |
1251 | */ | |
1252 | for (j = 0; j < vcnt; j++) | |
1253 | if (memcmp(page_address(fbio->bi_io_vec[j].bv_page), | |
1254 | page_address(tbio->bi_io_vec[j].bv_page), | |
1255 | PAGE_SIZE)) | |
1256 | break; | |
1257 | if (j == vcnt) | |
1258 | continue; | |
1259 | mddev->resync_mismatches += r10_bio->sectors; | |
1260 | } | |
18f08819 N |
1261 | if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) |
1262 | /* Don't fix anything. */ | |
1263 | continue; | |
1da177e4 LT |
1264 | /* Ok, we need to write this bio |
1265 | * First we need to fixup bv_offset, bv_len and | |
1266 | * bi_vecs, as the read request might have corrupted these | |
1267 | */ | |
1268 | tbio->bi_vcnt = vcnt; | |
1269 | tbio->bi_size = r10_bio->sectors << 9; | |
1270 | tbio->bi_idx = 0; | |
1271 | tbio->bi_phys_segments = 0; | |
1272 | tbio->bi_hw_segments = 0; | |
1273 | tbio->bi_hw_front_size = 0; | |
1274 | tbio->bi_hw_back_size = 0; | |
1275 | tbio->bi_flags &= ~(BIO_POOL_MASK - 1); | |
1276 | tbio->bi_flags |= 1 << BIO_UPTODATE; | |
1277 | tbio->bi_next = NULL; | |
1278 | tbio->bi_rw = WRITE; | |
1279 | tbio->bi_private = r10_bio; | |
1280 | tbio->bi_sector = r10_bio->devs[i].addr; | |
1281 | ||
1282 | for (j=0; j < vcnt ; j++) { | |
1283 | tbio->bi_io_vec[j].bv_offset = 0; | |
1284 | tbio->bi_io_vec[j].bv_len = PAGE_SIZE; | |
1285 | ||
1286 | memcpy(page_address(tbio->bi_io_vec[j].bv_page), | |
1287 | page_address(fbio->bi_io_vec[j].bv_page), | |
1288 | PAGE_SIZE); | |
1289 | } | |
1290 | tbio->bi_end_io = end_sync_write; | |
1291 | ||
1292 | d = r10_bio->devs[i].devnum; | |
1293 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1294 | atomic_inc(&r10_bio->remaining); | |
1295 | md_sync_acct(conf->mirrors[d].rdev->bdev, tbio->bi_size >> 9); | |
1296 | ||
1297 | tbio->bi_sector += conf->mirrors[d].rdev->data_offset; | |
1298 | tbio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1299 | generic_make_request(tbio); | |
1300 | } | |
1301 | ||
1302 | done: | |
1303 | if (atomic_dec_and_test(&r10_bio->remaining)) { | |
1304 | md_done_sync(mddev, r10_bio->sectors, 1); | |
1305 | put_buf(r10_bio); | |
1306 | } | |
1307 | } | |
1308 | ||
1309 | /* | |
1310 | * Now for the recovery code. | |
1311 | * Recovery happens across physical sectors. | |
1312 | * We recover all non-is_sync drives by finding the virtual address of | |
1313 | * each, and then choose a working drive that also has that virt address. | |
1314 | * There is a separate r10_bio for each non-in_sync drive. | |
1315 | * Only the first two slots are in use. The first for reading, | |
1316 | * The second for writing. | |
1317 | * | |
1318 | */ | |
1319 | ||
1320 | static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio) | |
1321 | { | |
1322 | conf_t *conf = mddev_to_conf(mddev); | |
1323 | int i, d; | |
1324 | struct bio *bio, *wbio; | |
1325 | ||
1326 | ||
1327 | /* move the pages across to the second bio | |
1328 | * and submit the write request | |
1329 | */ | |
1330 | bio = r10_bio->devs[0].bio; | |
1331 | wbio = r10_bio->devs[1].bio; | |
1332 | for (i=0; i < wbio->bi_vcnt; i++) { | |
1333 | struct page *p = bio->bi_io_vec[i].bv_page; | |
1334 | bio->bi_io_vec[i].bv_page = wbio->bi_io_vec[i].bv_page; | |
1335 | wbio->bi_io_vec[i].bv_page = p; | |
1336 | } | |
1337 | d = r10_bio->devs[1].devnum; | |
1338 | ||
1339 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1340 | md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9); | |
0eb3ff12 N |
1341 | if (test_bit(R10BIO_Uptodate, &r10_bio->state)) |
1342 | generic_make_request(wbio); | |
1343 | else | |
1344 | bio_endio(wbio, wbio->bi_size, -EIO); | |
1da177e4 LT |
1345 | } |
1346 | ||
1347 | ||
1348 | /* | |
1349 | * This is a kernel thread which: | |
1350 | * | |
1351 | * 1. Retries failed read operations on working mirrors. | |
1352 | * 2. Updates the raid superblock when problems encounter. | |
1353 | * 3. Performs writes following reads for array syncronising. | |
1354 | */ | |
1355 | ||
1356 | static void raid10d(mddev_t *mddev) | |
1357 | { | |
1358 | r10bio_t *r10_bio; | |
1359 | struct bio *bio; | |
1360 | unsigned long flags; | |
1361 | conf_t *conf = mddev_to_conf(mddev); | |
1362 | struct list_head *head = &conf->retry_list; | |
1363 | int unplug=0; | |
1364 | mdk_rdev_t *rdev; | |
1365 | ||
1366 | md_check_recovery(mddev); | |
1da177e4 LT |
1367 | |
1368 | for (;;) { | |
1369 | char b[BDEVNAME_SIZE]; | |
1370 | spin_lock_irqsave(&conf->device_lock, flags); | |
6cce3b23 N |
1371 | |
1372 | if (conf->pending_bio_list.head) { | |
1373 | bio = bio_list_get(&conf->pending_bio_list); | |
1374 | blk_remove_plug(mddev->queue); | |
1375 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1376 | /* flush any pending bitmap writes to disk before proceeding w/ I/O */ | |
1377 | if (bitmap_unplug(mddev->bitmap) != 0) | |
1378 | printk("%s: bitmap file write failed!\n", mdname(mddev)); | |
1379 | ||
1380 | while (bio) { /* submit pending writes */ | |
1381 | struct bio *next = bio->bi_next; | |
1382 | bio->bi_next = NULL; | |
1383 | generic_make_request(bio); | |
1384 | bio = next; | |
1385 | } | |
1386 | unplug = 1; | |
1387 | ||
1388 | continue; | |
1389 | } | |
1390 | ||
1da177e4 LT |
1391 | if (list_empty(head)) |
1392 | break; | |
1393 | r10_bio = list_entry(head->prev, r10bio_t, retry_list); | |
1394 | list_del(head->prev); | |
4443ae10 | 1395 | conf->nr_queued--; |
1da177e4 LT |
1396 | spin_unlock_irqrestore(&conf->device_lock, flags); |
1397 | ||
1398 | mddev = r10_bio->mddev; | |
1399 | conf = mddev_to_conf(mddev); | |
1400 | if (test_bit(R10BIO_IsSync, &r10_bio->state)) { | |
1401 | sync_request_write(mddev, r10_bio); | |
1402 | unplug = 1; | |
1403 | } else if (test_bit(R10BIO_IsRecover, &r10_bio->state)) { | |
1404 | recovery_request_write(mddev, r10_bio); | |
1405 | unplug = 1; | |
1406 | } else { | |
1407 | int mirror; | |
4443ae10 N |
1408 | /* we got a read error. Maybe the drive is bad. Maybe just |
1409 | * the block and we can fix it. | |
1410 | * We freeze all other IO, and try reading the block from | |
1411 | * other devices. When we find one, we re-write | |
1412 | * and check it that fixes the read error. | |
1413 | * This is all done synchronously while the array is | |
1414 | * frozen. | |
1415 | */ | |
1416 | int sect = 0; /* Offset from r10_bio->sector */ | |
1417 | int sectors = r10_bio->sectors; | |
1418 | freeze_array(conf); | |
1419 | if (mddev->ro == 0) while(sectors) { | |
1420 | int s = sectors; | |
1421 | int sl = r10_bio->read_slot; | |
1422 | int success = 0; | |
1423 | ||
1424 | if (s > (PAGE_SIZE>>9)) | |
1425 | s = PAGE_SIZE >> 9; | |
1426 | ||
e0a33270 | 1427 | rcu_read_lock(); |
4443ae10 N |
1428 | do { |
1429 | int d = r10_bio->devs[sl].devnum; | |
e0a33270 | 1430 | rdev = rcu_dereference(conf->mirrors[d].rdev); |
4443ae10 | 1431 | if (rdev && |
e0a33270 N |
1432 | test_bit(In_sync, &rdev->flags)) { |
1433 | atomic_inc(&rdev->nr_pending); | |
1434 | rcu_read_unlock(); | |
1435 | success = sync_page_io(rdev->bdev, | |
1436 | r10_bio->devs[sl].addr + | |
1437 | sect + rdev->data_offset, | |
1438 | s<<9, | |
1439 | conf->tmppage, READ); | |
1440 | rdev_dec_pending(rdev, mddev); | |
1441 | rcu_read_lock(); | |
1442 | if (success) | |
1443 | break; | |
4443ae10 | 1444 | } |
e0a33270 N |
1445 | sl++; |
1446 | if (sl == conf->copies) | |
1447 | sl = 0; | |
4443ae10 | 1448 | } while (!success && sl != r10_bio->read_slot); |
e0a33270 | 1449 | rcu_read_unlock(); |
4443ae10 N |
1450 | |
1451 | if (success) { | |
097426f6 | 1452 | int start = sl; |
4443ae10 | 1453 | /* write it back and re-read */ |
e0a33270 | 1454 | rcu_read_lock(); |
4443ae10 N |
1455 | while (sl != r10_bio->read_slot) { |
1456 | int d; | |
1457 | if (sl==0) | |
1458 | sl = conf->copies; | |
1459 | sl--; | |
1460 | d = r10_bio->devs[sl].devnum; | |
e0a33270 | 1461 | rdev = rcu_dereference(conf->mirrors[d].rdev); |
4443ae10 N |
1462 | if (rdev && |
1463 | test_bit(In_sync, &rdev->flags)) { | |
e0a33270 N |
1464 | atomic_inc(&rdev->nr_pending); |
1465 | rcu_read_unlock(); | |
df30d0f4 | 1466 | atomic_add(s, &rdev->corrected_errors); |
4443ae10 N |
1467 | if (sync_page_io(rdev->bdev, |
1468 | r10_bio->devs[sl].addr + | |
1469 | sect + rdev->data_offset, | |
097426f6 N |
1470 | s<<9, conf->tmppage, WRITE) == 0) |
1471 | /* Well, this device is dead */ | |
1472 | md_error(mddev, rdev); | |
e0a33270 N |
1473 | rdev_dec_pending(rdev, mddev); |
1474 | rcu_read_lock(); | |
097426f6 N |
1475 | } |
1476 | } | |
1477 | sl = start; | |
1478 | while (sl != r10_bio->read_slot) { | |
1479 | int d; | |
1480 | if (sl==0) | |
1481 | sl = conf->copies; | |
1482 | sl--; | |
1483 | d = r10_bio->devs[sl].devnum; | |
e0a33270 | 1484 | rdev = rcu_dereference(conf->mirrors[d].rdev); |
097426f6 N |
1485 | if (rdev && |
1486 | test_bit(In_sync, &rdev->flags)) { | |
e0a33270 N |
1487 | atomic_inc(&rdev->nr_pending); |
1488 | rcu_read_unlock(); | |
097426f6 | 1489 | if (sync_page_io(rdev->bdev, |
4443ae10 N |
1490 | r10_bio->devs[sl].addr + |
1491 | sect + rdev->data_offset, | |
097426f6 | 1492 | s<<9, conf->tmppage, READ) == 0) |
4443ae10 N |
1493 | /* Well, this device is dead */ |
1494 | md_error(mddev, rdev); | |
e0a33270 N |
1495 | rdev_dec_pending(rdev, mddev); |
1496 | rcu_read_lock(); | |
4443ae10 N |
1497 | } |
1498 | } | |
e0a33270 | 1499 | rcu_read_unlock(); |
4443ae10 N |
1500 | } else { |
1501 | /* Cannot read from anywhere -- bye bye array */ | |
1502 | md_error(mddev, conf->mirrors[r10_bio->devs[r10_bio->read_slot].devnum].rdev); | |
1503 | break; | |
1504 | } | |
1505 | sectors -= s; | |
1506 | sect += s; | |
1507 | } | |
1508 | ||
1509 | unfreeze_array(conf); | |
1510 | ||
1da177e4 | 1511 | bio = r10_bio->devs[r10_bio->read_slot].bio; |
0eb3ff12 N |
1512 | r10_bio->devs[r10_bio->read_slot].bio = |
1513 | mddev->ro ? IO_BLOCKED : NULL; | |
1da177e4 LT |
1514 | bio_put(bio); |
1515 | mirror = read_balance(conf, r10_bio); | |
1516 | if (mirror == -1) { | |
1517 | printk(KERN_ALERT "raid10: %s: unrecoverable I/O" | |
1518 | " read error for block %llu\n", | |
1519 | bdevname(bio->bi_bdev,b), | |
1520 | (unsigned long long)r10_bio->sector); | |
1521 | raid_end_bio_io(r10_bio); | |
1522 | } else { | |
1523 | rdev = conf->mirrors[mirror].rdev; | |
1524 | if (printk_ratelimit()) | |
1525 | printk(KERN_ERR "raid10: %s: redirecting sector %llu to" | |
1526 | " another mirror\n", | |
1527 | bdevname(rdev->bdev,b), | |
1528 | (unsigned long long)r10_bio->sector); | |
1529 | bio = bio_clone(r10_bio->master_bio, GFP_NOIO); | |
1530 | r10_bio->devs[r10_bio->read_slot].bio = bio; | |
1531 | bio->bi_sector = r10_bio->devs[r10_bio->read_slot].addr | |
1532 | + rdev->data_offset; | |
1533 | bio->bi_bdev = rdev->bdev; | |
1534 | bio->bi_rw = READ; | |
1535 | bio->bi_private = r10_bio; | |
1536 | bio->bi_end_io = raid10_end_read_request; | |
1537 | unplug = 1; | |
1538 | generic_make_request(bio); | |
1539 | } | |
1540 | } | |
1541 | } | |
1542 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
1543 | if (unplug) | |
1544 | unplug_slaves(mddev); | |
1545 | } | |
1546 | ||
1547 | ||
1548 | static int init_resync(conf_t *conf) | |
1549 | { | |
1550 | int buffs; | |
1551 | ||
1552 | buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; | |
b6385483 | 1553 | BUG_ON(conf->r10buf_pool); |
1da177e4 LT |
1554 | conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf); |
1555 | if (!conf->r10buf_pool) | |
1556 | return -ENOMEM; | |
1557 | conf->next_resync = 0; | |
1558 | return 0; | |
1559 | } | |
1560 | ||
1561 | /* | |
1562 | * perform a "sync" on one "block" | |
1563 | * | |
1564 | * We need to make sure that no normal I/O request - particularly write | |
1565 | * requests - conflict with active sync requests. | |
1566 | * | |
1567 | * This is achieved by tracking pending requests and a 'barrier' concept | |
1568 | * that can be installed to exclude normal IO requests. | |
1569 | * | |
1570 | * Resync and recovery are handled very differently. | |
1571 | * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery. | |
1572 | * | |
1573 | * For resync, we iterate over virtual addresses, read all copies, | |
1574 | * and update if there are differences. If only one copy is live, | |
1575 | * skip it. | |
1576 | * For recovery, we iterate over physical addresses, read a good | |
1577 | * value for each non-in_sync drive, and over-write. | |
1578 | * | |
1579 | * So, for recovery we may have several outstanding complex requests for a | |
1580 | * given address, one for each out-of-sync device. We model this by allocating | |
1581 | * a number of r10_bio structures, one for each out-of-sync device. | |
1582 | * As we setup these structures, we collect all bio's together into a list | |
1583 | * which we then process collectively to add pages, and then process again | |
1584 | * to pass to generic_make_request. | |
1585 | * | |
1586 | * The r10_bio structures are linked using a borrowed master_bio pointer. | |
1587 | * This link is counted in ->remaining. When the r10_bio that points to NULL | |
1588 | * has its remaining count decremented to 0, the whole complex operation | |
1589 | * is complete. | |
1590 | * | |
1591 | */ | |
1592 | ||
57afd89f | 1593 | static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
1da177e4 LT |
1594 | { |
1595 | conf_t *conf = mddev_to_conf(mddev); | |
1596 | r10bio_t *r10_bio; | |
1597 | struct bio *biolist = NULL, *bio; | |
1598 | sector_t max_sector, nr_sectors; | |
1599 | int disk; | |
1600 | int i; | |
6cce3b23 N |
1601 | int max_sync; |
1602 | int sync_blocks; | |
1da177e4 LT |
1603 | |
1604 | sector_t sectors_skipped = 0; | |
1605 | int chunks_skipped = 0; | |
1606 | ||
1607 | if (!conf->r10buf_pool) | |
1608 | if (init_resync(conf)) | |
57afd89f | 1609 | return 0; |
1da177e4 LT |
1610 | |
1611 | skipped: | |
1612 | max_sector = mddev->size << 1; | |
1613 | if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) | |
1614 | max_sector = mddev->resync_max_sectors; | |
1615 | if (sector_nr >= max_sector) { | |
6cce3b23 N |
1616 | /* If we aborted, we need to abort the |
1617 | * sync on the 'current' bitmap chucks (there can | |
1618 | * be several when recovering multiple devices). | |
1619 | * as we may have started syncing it but not finished. | |
1620 | * We can find the current address in | |
1621 | * mddev->curr_resync, but for recovery, | |
1622 | * we need to convert that to several | |
1623 | * virtual addresses. | |
1624 | */ | |
1625 | if (mddev->curr_resync < max_sector) { /* aborted */ | |
1626 | if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) | |
1627 | bitmap_end_sync(mddev->bitmap, mddev->curr_resync, | |
1628 | &sync_blocks, 1); | |
1629 | else for (i=0; i<conf->raid_disks; i++) { | |
1630 | sector_t sect = | |
1631 | raid10_find_virt(conf, mddev->curr_resync, i); | |
1632 | bitmap_end_sync(mddev->bitmap, sect, | |
1633 | &sync_blocks, 1); | |
1634 | } | |
1635 | } else /* completed sync */ | |
1636 | conf->fullsync = 0; | |
1637 | ||
1638 | bitmap_close_sync(mddev->bitmap); | |
1da177e4 | 1639 | close_sync(conf); |
57afd89f | 1640 | *skipped = 1; |
1da177e4 LT |
1641 | return sectors_skipped; |
1642 | } | |
1643 | if (chunks_skipped >= conf->raid_disks) { | |
1644 | /* if there has been nothing to do on any drive, | |
1645 | * then there is nothing to do at all.. | |
1646 | */ | |
57afd89f N |
1647 | *skipped = 1; |
1648 | return (max_sector - sector_nr) + sectors_skipped; | |
1da177e4 LT |
1649 | } |
1650 | ||
1651 | /* make sure whole request will fit in a chunk - if chunks | |
1652 | * are meaningful | |
1653 | */ | |
1654 | if (conf->near_copies < conf->raid_disks && | |
1655 | max_sector > (sector_nr | conf->chunk_mask)) | |
1656 | max_sector = (sector_nr | conf->chunk_mask) + 1; | |
1657 | /* | |
1658 | * If there is non-resync activity waiting for us then | |
1659 | * put in a delay to throttle resync. | |
1660 | */ | |
0a27ec96 | 1661 | if (!go_faster && conf->nr_waiting) |
1da177e4 | 1662 | msleep_interruptible(1000); |
1da177e4 LT |
1663 | |
1664 | /* Again, very different code for resync and recovery. | |
1665 | * Both must result in an r10bio with a list of bios that | |
1666 | * have bi_end_io, bi_sector, bi_bdev set, | |
1667 | * and bi_private set to the r10bio. | |
1668 | * For recovery, we may actually create several r10bios | |
1669 | * with 2 bios in each, that correspond to the bios in the main one. | |
1670 | * In this case, the subordinate r10bios link back through a | |
1671 | * borrowed master_bio pointer, and the counter in the master | |
1672 | * includes a ref from each subordinate. | |
1673 | */ | |
1674 | /* First, we decide what to do and set ->bi_end_io | |
1675 | * To end_sync_read if we want to read, and | |
1676 | * end_sync_write if we will want to write. | |
1677 | */ | |
1678 | ||
6cce3b23 | 1679 | max_sync = RESYNC_PAGES << (PAGE_SHIFT-9); |
1da177e4 LT |
1680 | if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { |
1681 | /* recovery... the complicated one */ | |
1682 | int i, j, k; | |
1683 | r10_bio = NULL; | |
1684 | ||
1685 | for (i=0 ; i<conf->raid_disks; i++) | |
1686 | if (conf->mirrors[i].rdev && | |
b2d444d7 | 1687 | !test_bit(In_sync, &conf->mirrors[i].rdev->flags)) { |
6cce3b23 | 1688 | int still_degraded = 0; |
1da177e4 LT |
1689 | /* want to reconstruct this device */ |
1690 | r10bio_t *rb2 = r10_bio; | |
6cce3b23 N |
1691 | sector_t sect = raid10_find_virt(conf, sector_nr, i); |
1692 | int must_sync; | |
1693 | /* Unless we are doing a full sync, we only need | |
1694 | * to recover the block if it is set in the bitmap | |
1695 | */ | |
1696 | must_sync = bitmap_start_sync(mddev->bitmap, sect, | |
1697 | &sync_blocks, 1); | |
1698 | if (sync_blocks < max_sync) | |
1699 | max_sync = sync_blocks; | |
1700 | if (!must_sync && | |
1701 | !conf->fullsync) { | |
1702 | /* yep, skip the sync_blocks here, but don't assume | |
1703 | * that there will never be anything to do here | |
1704 | */ | |
1705 | chunks_skipped = -1; | |
1706 | continue; | |
1707 | } | |
1da177e4 LT |
1708 | |
1709 | r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO); | |
6cce3b23 | 1710 | raise_barrier(conf, rb2 != NULL); |
1da177e4 LT |
1711 | atomic_set(&r10_bio->remaining, 0); |
1712 | ||
1713 | r10_bio->master_bio = (struct bio*)rb2; | |
1714 | if (rb2) | |
1715 | atomic_inc(&rb2->remaining); | |
1716 | r10_bio->mddev = mddev; | |
1717 | set_bit(R10BIO_IsRecover, &r10_bio->state); | |
6cce3b23 N |
1718 | r10_bio->sector = sect; |
1719 | ||
1da177e4 | 1720 | raid10_find_phys(conf, r10_bio); |
6cce3b23 N |
1721 | /* Need to check if this section will still be |
1722 | * degraded | |
1723 | */ | |
1724 | for (j=0; j<conf->copies;j++) { | |
1725 | int d = r10_bio->devs[j].devnum; | |
1726 | if (conf->mirrors[d].rdev == NULL || | |
a24a8dd8 | 1727 | test_bit(Faulty, &conf->mirrors[d].rdev->flags)) { |
6cce3b23 | 1728 | still_degraded = 1; |
a24a8dd8 N |
1729 | break; |
1730 | } | |
6cce3b23 N |
1731 | } |
1732 | must_sync = bitmap_start_sync(mddev->bitmap, sect, | |
1733 | &sync_blocks, still_degraded); | |
1734 | ||
1da177e4 LT |
1735 | for (j=0; j<conf->copies;j++) { |
1736 | int d = r10_bio->devs[j].devnum; | |
1737 | if (conf->mirrors[d].rdev && | |
b2d444d7 | 1738 | test_bit(In_sync, &conf->mirrors[d].rdev->flags)) { |
1da177e4 LT |
1739 | /* This is where we read from */ |
1740 | bio = r10_bio->devs[0].bio; | |
1741 | bio->bi_next = biolist; | |
1742 | biolist = bio; | |
1743 | bio->bi_private = r10_bio; | |
1744 | bio->bi_end_io = end_sync_read; | |
1745 | bio->bi_rw = 0; | |
1746 | bio->bi_sector = r10_bio->devs[j].addr + | |
1747 | conf->mirrors[d].rdev->data_offset; | |
1748 | bio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1749 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1750 | atomic_inc(&r10_bio->remaining); | |
1751 | /* and we write to 'i' */ | |
1752 | ||
1753 | for (k=0; k<conf->copies; k++) | |
1754 | if (r10_bio->devs[k].devnum == i) | |
1755 | break; | |
1756 | bio = r10_bio->devs[1].bio; | |
1757 | bio->bi_next = biolist; | |
1758 | biolist = bio; | |
1759 | bio->bi_private = r10_bio; | |
1760 | bio->bi_end_io = end_sync_write; | |
1761 | bio->bi_rw = 1; | |
1762 | bio->bi_sector = r10_bio->devs[k].addr + | |
1763 | conf->mirrors[i].rdev->data_offset; | |
1764 | bio->bi_bdev = conf->mirrors[i].rdev->bdev; | |
1765 | ||
1766 | r10_bio->devs[0].devnum = d; | |
1767 | r10_bio->devs[1].devnum = i; | |
1768 | ||
1769 | break; | |
1770 | } | |
1771 | } | |
1772 | if (j == conf->copies) { | |
87fc767b N |
1773 | /* Cannot recover, so abort the recovery */ |
1774 | put_buf(r10_bio); | |
1775 | r10_bio = rb2; | |
1776 | if (!test_and_set_bit(MD_RECOVERY_ERR, &mddev->recovery)) | |
1777 | printk(KERN_INFO "raid10: %s: insufficient working devices for recovery.\n", | |
1778 | mdname(mddev)); | |
1779 | break; | |
1da177e4 LT |
1780 | } |
1781 | } | |
1782 | if (biolist == NULL) { | |
1783 | while (r10_bio) { | |
1784 | r10bio_t *rb2 = r10_bio; | |
1785 | r10_bio = (r10bio_t*) rb2->master_bio; | |
1786 | rb2->master_bio = NULL; | |
1787 | put_buf(rb2); | |
1788 | } | |
1789 | goto giveup; | |
1790 | } | |
1791 | } else { | |
1792 | /* resync. Schedule a read for every block at this virt offset */ | |
1793 | int count = 0; | |
6cce3b23 N |
1794 | |
1795 | if (!bitmap_start_sync(mddev->bitmap, sector_nr, | |
1796 | &sync_blocks, mddev->degraded) && | |
1797 | !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { | |
1798 | /* We can skip this block */ | |
1799 | *skipped = 1; | |
1800 | return sync_blocks + sectors_skipped; | |
1801 | } | |
1802 | if (sync_blocks < max_sync) | |
1803 | max_sync = sync_blocks; | |
1da177e4 LT |
1804 | r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO); |
1805 | ||
1da177e4 LT |
1806 | r10_bio->mddev = mddev; |
1807 | atomic_set(&r10_bio->remaining, 0); | |
6cce3b23 N |
1808 | raise_barrier(conf, 0); |
1809 | conf->next_resync = sector_nr; | |
1da177e4 LT |
1810 | |
1811 | r10_bio->master_bio = NULL; | |
1812 | r10_bio->sector = sector_nr; | |
1813 | set_bit(R10BIO_IsSync, &r10_bio->state); | |
1814 | raid10_find_phys(conf, r10_bio); | |
1815 | r10_bio->sectors = (sector_nr | conf->chunk_mask) - sector_nr +1; | |
1816 | ||
1817 | for (i=0; i<conf->copies; i++) { | |
1818 | int d = r10_bio->devs[i].devnum; | |
1819 | bio = r10_bio->devs[i].bio; | |
1820 | bio->bi_end_io = NULL; | |
1821 | if (conf->mirrors[d].rdev == NULL || | |
b2d444d7 | 1822 | test_bit(Faulty, &conf->mirrors[d].rdev->flags)) |
1da177e4 LT |
1823 | continue; |
1824 | atomic_inc(&conf->mirrors[d].rdev->nr_pending); | |
1825 | atomic_inc(&r10_bio->remaining); | |
1826 | bio->bi_next = biolist; | |
1827 | biolist = bio; | |
1828 | bio->bi_private = r10_bio; | |
1829 | bio->bi_end_io = end_sync_read; | |
1830 | bio->bi_rw = 0; | |
1831 | bio->bi_sector = r10_bio->devs[i].addr + | |
1832 | conf->mirrors[d].rdev->data_offset; | |
1833 | bio->bi_bdev = conf->mirrors[d].rdev->bdev; | |
1834 | count++; | |
1835 | } | |
1836 | ||
1837 | if (count < 2) { | |
1838 | for (i=0; i<conf->copies; i++) { | |
1839 | int d = r10_bio->devs[i].devnum; | |
1840 | if (r10_bio->devs[i].bio->bi_end_io) | |
1841 | rdev_dec_pending(conf->mirrors[d].rdev, mddev); | |
1842 | } | |
1843 | put_buf(r10_bio); | |
1844 | biolist = NULL; | |
1845 | goto giveup; | |
1846 | } | |
1847 | } | |
1848 | ||
1849 | for (bio = biolist; bio ; bio=bio->bi_next) { | |
1850 | ||
1851 | bio->bi_flags &= ~(BIO_POOL_MASK - 1); | |
1852 | if (bio->bi_end_io) | |
1853 | bio->bi_flags |= 1 << BIO_UPTODATE; | |
1854 | bio->bi_vcnt = 0; | |
1855 | bio->bi_idx = 0; | |
1856 | bio->bi_phys_segments = 0; | |
1857 | bio->bi_hw_segments = 0; | |
1858 | bio->bi_size = 0; | |
1859 | } | |
1860 | ||
1861 | nr_sectors = 0; | |
6cce3b23 N |
1862 | if (sector_nr + max_sync < max_sector) |
1863 | max_sector = sector_nr + max_sync; | |
1da177e4 LT |
1864 | do { |
1865 | struct page *page; | |
1866 | int len = PAGE_SIZE; | |
1867 | disk = 0; | |
1868 | if (sector_nr + (len>>9) > max_sector) | |
1869 | len = (max_sector - sector_nr) << 9; | |
1870 | if (len == 0) | |
1871 | break; | |
1872 | for (bio= biolist ; bio ; bio=bio->bi_next) { | |
1873 | page = bio->bi_io_vec[bio->bi_vcnt].bv_page; | |
1874 | if (bio_add_page(bio, page, len, 0) == 0) { | |
1875 | /* stop here */ | |
1876 | struct bio *bio2; | |
1877 | bio->bi_io_vec[bio->bi_vcnt].bv_page = page; | |
1878 | for (bio2 = biolist; bio2 && bio2 != bio; bio2 = bio2->bi_next) { | |
1879 | /* remove last page from this bio */ | |
1880 | bio2->bi_vcnt--; | |
1881 | bio2->bi_size -= len; | |
1882 | bio2->bi_flags &= ~(1<< BIO_SEG_VALID); | |
1883 | } | |
1884 | goto bio_full; | |
1885 | } | |
1886 | disk = i; | |
1887 | } | |
1888 | nr_sectors += len>>9; | |
1889 | sector_nr += len>>9; | |
1890 | } while (biolist->bi_vcnt < RESYNC_PAGES); | |
1891 | bio_full: | |
1892 | r10_bio->sectors = nr_sectors; | |
1893 | ||
1894 | while (biolist) { | |
1895 | bio = biolist; | |
1896 | biolist = biolist->bi_next; | |
1897 | ||
1898 | bio->bi_next = NULL; | |
1899 | r10_bio = bio->bi_private; | |
1900 | r10_bio->sectors = nr_sectors; | |
1901 | ||
1902 | if (bio->bi_end_io == end_sync_read) { | |
1903 | md_sync_acct(bio->bi_bdev, nr_sectors); | |
1904 | generic_make_request(bio); | |
1905 | } | |
1906 | } | |
1907 | ||
57afd89f N |
1908 | if (sectors_skipped) |
1909 | /* pretend they weren't skipped, it makes | |
1910 | * no important difference in this case | |
1911 | */ | |
1912 | md_done_sync(mddev, sectors_skipped, 1); | |
1913 | ||
1da177e4 LT |
1914 | return sectors_skipped + nr_sectors; |
1915 | giveup: | |
1916 | /* There is nowhere to write, so all non-sync | |
1917 | * drives must be failed, so try the next chunk... | |
1918 | */ | |
1919 | { | |
57afd89f | 1920 | sector_t sec = max_sector - sector_nr; |
1da177e4 LT |
1921 | sectors_skipped += sec; |
1922 | chunks_skipped ++; | |
1923 | sector_nr = max_sector; | |
1da177e4 LT |
1924 | goto skipped; |
1925 | } | |
1926 | } | |
1927 | ||
1928 | static int run(mddev_t *mddev) | |
1929 | { | |
1930 | conf_t *conf; | |
1931 | int i, disk_idx; | |
1932 | mirror_info_t *disk; | |
1933 | mdk_rdev_t *rdev; | |
1934 | struct list_head *tmp; | |
c93983bf | 1935 | int nc, fc, fo; |
1da177e4 LT |
1936 | sector_t stride, size; |
1937 | ||
2604b703 N |
1938 | if (mddev->chunk_size == 0) { |
1939 | printk(KERN_ERR "md/raid10: non-zero chunk size required.\n"); | |
1940 | return -EINVAL; | |
1da177e4 | 1941 | } |
2604b703 | 1942 | |
1da177e4 LT |
1943 | nc = mddev->layout & 255; |
1944 | fc = (mddev->layout >> 8) & 255; | |
c93983bf | 1945 | fo = mddev->layout & (1<<16); |
1da177e4 | 1946 | if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks || |
c93983bf | 1947 | (mddev->layout >> 17)) { |
1da177e4 LT |
1948 | printk(KERN_ERR "raid10: %s: unsupported raid10 layout: 0x%8x\n", |
1949 | mdname(mddev), mddev->layout); | |
1950 | goto out; | |
1951 | } | |
1952 | /* | |
1953 | * copy the already verified devices into our private RAID10 | |
1954 | * bookkeeping area. [whatever we allocate in run(), | |
1955 | * should be freed in stop()] | |
1956 | */ | |
4443ae10 | 1957 | conf = kzalloc(sizeof(conf_t), GFP_KERNEL); |
1da177e4 LT |
1958 | mddev->private = conf; |
1959 | if (!conf) { | |
1960 | printk(KERN_ERR "raid10: couldn't allocate memory for %s\n", | |
1961 | mdname(mddev)); | |
1962 | goto out; | |
1963 | } | |
4443ae10 | 1964 | conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks, |
1da177e4 LT |
1965 | GFP_KERNEL); |
1966 | if (!conf->mirrors) { | |
1967 | printk(KERN_ERR "raid10: couldn't allocate memory for %s\n", | |
1968 | mdname(mddev)); | |
1969 | goto out_free_conf; | |
1970 | } | |
4443ae10 N |
1971 | |
1972 | conf->tmppage = alloc_page(GFP_KERNEL); | |
1973 | if (!conf->tmppage) | |
1974 | goto out_free_conf; | |
1da177e4 LT |
1975 | |
1976 | conf->near_copies = nc; | |
1977 | conf->far_copies = fc; | |
1978 | conf->copies = nc*fc; | |
c93983bf | 1979 | conf->far_offset = fo; |
1da177e4 LT |
1980 | conf->chunk_mask = (sector_t)(mddev->chunk_size>>9)-1; |
1981 | conf->chunk_shift = ffz(~mddev->chunk_size) - 9; | |
c93983bf N |
1982 | if (fo) |
1983 | conf->stride = 1 << conf->chunk_shift; | |
1984 | else { | |
1985 | stride = mddev->size >> (conf->chunk_shift-1); | |
1986 | sector_div(stride, fc); | |
1987 | conf->stride = stride << conf->chunk_shift; | |
1988 | } | |
1da177e4 LT |
1989 | conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc, |
1990 | r10bio_pool_free, conf); | |
1991 | if (!conf->r10bio_pool) { | |
1992 | printk(KERN_ERR "raid10: couldn't allocate memory for %s\n", | |
1993 | mdname(mddev)); | |
1994 | goto out_free_conf; | |
1995 | } | |
1da177e4 LT |
1996 | |
1997 | ITERATE_RDEV(mddev, rdev, tmp) { | |
1998 | disk_idx = rdev->raid_disk; | |
1999 | if (disk_idx >= mddev->raid_disks | |
2000 | || disk_idx < 0) | |
2001 | continue; | |
2002 | disk = conf->mirrors + disk_idx; | |
2003 | ||
2004 | disk->rdev = rdev; | |
2005 | ||
2006 | blk_queue_stack_limits(mddev->queue, | |
2007 | rdev->bdev->bd_disk->queue); | |
2008 | /* as we don't honour merge_bvec_fn, we must never risk | |
2009 | * violating it, so limit ->max_sector to one PAGE, as | |
2010 | * a one page request is never in violation. | |
2011 | */ | |
2012 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
2013 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) | |
2014 | mddev->queue->max_sectors = (PAGE_SIZE>>9); | |
2015 | ||
2016 | disk->head_position = 0; | |
b2d444d7 | 2017 | if (!test_bit(Faulty, &rdev->flags) && test_bit(In_sync, &rdev->flags)) |
1da177e4 LT |
2018 | conf->working_disks++; |
2019 | } | |
2020 | conf->raid_disks = mddev->raid_disks; | |
2021 | conf->mddev = mddev; | |
2022 | spin_lock_init(&conf->device_lock); | |
2023 | INIT_LIST_HEAD(&conf->retry_list); | |
2024 | ||
2025 | spin_lock_init(&conf->resync_lock); | |
0a27ec96 | 2026 | init_waitqueue_head(&conf->wait_barrier); |
1da177e4 | 2027 | |
6d508242 N |
2028 | /* need to check that every block has at least one working mirror */ |
2029 | if (!enough(conf)) { | |
2030 | printk(KERN_ERR "raid10: not enough operational mirrors for %s\n", | |
2031 | mdname(mddev)); | |
1da177e4 LT |
2032 | goto out_free_conf; |
2033 | } | |
2034 | ||
2035 | mddev->degraded = 0; | |
2036 | for (i = 0; i < conf->raid_disks; i++) { | |
2037 | ||
2038 | disk = conf->mirrors + i; | |
2039 | ||
5fd6c1dc N |
2040 | if (!disk->rdev || |
2041 | !test_bit(In_sync, &rdev->flags)) { | |
1da177e4 LT |
2042 | disk->head_position = 0; |
2043 | mddev->degraded++; | |
2044 | } | |
2045 | } | |
2046 | ||
2047 | ||
2048 | mddev->thread = md_register_thread(raid10d, mddev, "%s_raid10"); | |
2049 | if (!mddev->thread) { | |
2050 | printk(KERN_ERR | |
2051 | "raid10: couldn't allocate thread for %s\n", | |
2052 | mdname(mddev)); | |
2053 | goto out_free_conf; | |
2054 | } | |
2055 | ||
2056 | printk(KERN_INFO | |
2057 | "raid10: raid set %s active with %d out of %d devices\n", | |
2058 | mdname(mddev), mddev->raid_disks - mddev->degraded, | |
2059 | mddev->raid_disks); | |
2060 | /* | |
2061 | * Ok, everything is just fine now | |
2062 | */ | |
88388328 N |
2063 | if (conf->far_offset) { |
2064 | size = mddev->size >> (conf->chunk_shift-1); | |
2065 | size *= conf->raid_disks; | |
2066 | size <<= conf->chunk_shift; | |
2067 | sector_div(size, conf->far_copies); | |
2068 | } else | |
2069 | size = conf->stride * conf->raid_disks; | |
1da177e4 LT |
2070 | sector_div(size, conf->near_copies); |
2071 | mddev->array_size = size/2; | |
2072 | mddev->resync_max_sectors = size; | |
2073 | ||
7a5febe9 N |
2074 | mddev->queue->unplug_fn = raid10_unplug; |
2075 | mddev->queue->issue_flush_fn = raid10_issue_flush; | |
2076 | ||
1da177e4 LT |
2077 | /* Calculate max read-ahead size. |
2078 | * We need to readahead at least twice a whole stripe.... | |
2079 | * maybe... | |
2080 | */ | |
2081 | { | |
8932c2e0 | 2082 | int stripe = conf->raid_disks * (mddev->chunk_size / PAGE_SIZE); |
1da177e4 LT |
2083 | stripe /= conf->near_copies; |
2084 | if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) | |
2085 | mddev->queue->backing_dev_info.ra_pages = 2* stripe; | |
2086 | } | |
2087 | ||
2088 | if (conf->near_copies < mddev->raid_disks) | |
2089 | blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec); | |
2090 | return 0; | |
2091 | ||
2092 | out_free_conf: | |
2093 | if (conf->r10bio_pool) | |
2094 | mempool_destroy(conf->r10bio_pool); | |
1345b1d8 | 2095 | safe_put_page(conf->tmppage); |
990a8baf | 2096 | kfree(conf->mirrors); |
1da177e4 LT |
2097 | kfree(conf); |
2098 | mddev->private = NULL; | |
2099 | out: | |
2100 | return -EIO; | |
2101 | } | |
2102 | ||
2103 | static int stop(mddev_t *mddev) | |
2104 | { | |
2105 | conf_t *conf = mddev_to_conf(mddev); | |
2106 | ||
2107 | md_unregister_thread(mddev->thread); | |
2108 | mddev->thread = NULL; | |
2109 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
2110 | if (conf->r10bio_pool) | |
2111 | mempool_destroy(conf->r10bio_pool); | |
990a8baf | 2112 | kfree(conf->mirrors); |
1da177e4 LT |
2113 | kfree(conf); |
2114 | mddev->private = NULL; | |
2115 | return 0; | |
2116 | } | |
2117 | ||
6cce3b23 N |
2118 | static void raid10_quiesce(mddev_t *mddev, int state) |
2119 | { | |
2120 | conf_t *conf = mddev_to_conf(mddev); | |
2121 | ||
2122 | switch(state) { | |
2123 | case 1: | |
2124 | raise_barrier(conf, 0); | |
2125 | break; | |
2126 | case 0: | |
2127 | lower_barrier(conf); | |
2128 | break; | |
2129 | } | |
2130 | if (mddev->thread) { | |
2131 | if (mddev->bitmap) | |
2132 | mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ; | |
2133 | else | |
2134 | mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT; | |
2135 | md_wakeup_thread(mddev->thread); | |
2136 | } | |
2137 | } | |
1da177e4 | 2138 | |
2604b703 | 2139 | static struct mdk_personality raid10_personality = |
1da177e4 LT |
2140 | { |
2141 | .name = "raid10", | |
2604b703 | 2142 | .level = 10, |
1da177e4 LT |
2143 | .owner = THIS_MODULE, |
2144 | .make_request = make_request, | |
2145 | .run = run, | |
2146 | .stop = stop, | |
2147 | .status = status, | |
2148 | .error_handler = error, | |
2149 | .hot_add_disk = raid10_add_disk, | |
2150 | .hot_remove_disk= raid10_remove_disk, | |
2151 | .spare_active = raid10_spare_active, | |
2152 | .sync_request = sync_request, | |
6cce3b23 | 2153 | .quiesce = raid10_quiesce, |
1da177e4 LT |
2154 | }; |
2155 | ||
2156 | static int __init raid_init(void) | |
2157 | { | |
2604b703 | 2158 | return register_md_personality(&raid10_personality); |
1da177e4 LT |
2159 | } |
2160 | ||
2161 | static void raid_exit(void) | |
2162 | { | |
2604b703 | 2163 | unregister_md_personality(&raid10_personality); |
1da177e4 LT |
2164 | } |
2165 | ||
2166 | module_init(raid_init); | |
2167 | module_exit(raid_exit); | |
2168 | MODULE_LICENSE("GPL"); | |
2169 | MODULE_ALIAS("md-personality-9"); /* RAID10 */ | |
d9d166c2 | 2170 | MODULE_ALIAS("md-raid10"); |
2604b703 | 2171 | MODULE_ALIAS("md-level-10"); |