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1 | /* | |
2 | raid0.c : Multiple Devices driver for Linux | |
3 | Copyright (C) 1994-96 Marc ZYNGIER | |
4 | <zyngier@ufr-info-p7.ibp.fr> or | |
5 | <maz@gloups.fdn.fr> | |
6 | Copyright (C) 1999, 2000 Ingo Molnar, Red Hat | |
7 | ||
8 | ||
9 | RAID-0 management functions. | |
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/blkdev.h> | |
22 | #include <linux/seq_file.h> | |
23 | #include <linux/slab.h> | |
24 | #include "md.h" | |
25 | #include "raid0.h" | |
26 | #include "raid5.h" | |
27 | ||
28 | static void raid0_unplug(struct request_queue *q) | |
29 | { | |
30 | mddev_t *mddev = q->queuedata; | |
31 | raid0_conf_t *conf = mddev->private; | |
32 | mdk_rdev_t **devlist = conf->devlist; | |
33 | int raid_disks = conf->strip_zone[0].nb_dev; | |
34 | int i; | |
35 | ||
36 | for (i=0; i < raid_disks; i++) { | |
37 | struct request_queue *r_queue = bdev_get_queue(devlist[i]->bdev); | |
38 | ||
39 | blk_unplug(r_queue); | |
40 | } | |
41 | } | |
42 | ||
43 | static int raid0_congested(void *data, int bits) | |
44 | { | |
45 | mddev_t *mddev = data; | |
46 | raid0_conf_t *conf = mddev->private; | |
47 | mdk_rdev_t **devlist = conf->devlist; | |
48 | int raid_disks = conf->strip_zone[0].nb_dev; | |
49 | int i, ret = 0; | |
50 | ||
51 | if (mddev_congested(mddev, bits)) | |
52 | return 1; | |
53 | ||
54 | for (i = 0; i < raid_disks && !ret ; i++) { | |
55 | struct request_queue *q = bdev_get_queue(devlist[i]->bdev); | |
56 | ||
57 | ret |= bdi_congested(&q->backing_dev_info, bits); | |
58 | } | |
59 | return ret; | |
60 | } | |
61 | ||
62 | /* | |
63 | * inform the user of the raid configuration | |
64 | */ | |
65 | static void dump_zones(mddev_t *mddev) | |
66 | { | |
67 | int j, k, h; | |
68 | sector_t zone_size = 0; | |
69 | sector_t zone_start = 0; | |
70 | char b[BDEVNAME_SIZE]; | |
71 | raid0_conf_t *conf = mddev->private; | |
72 | int raid_disks = conf->strip_zone[0].nb_dev; | |
73 | printk(KERN_INFO "******* %s configuration *********\n", | |
74 | mdname(mddev)); | |
75 | h = 0; | |
76 | for (j = 0; j < conf->nr_strip_zones; j++) { | |
77 | printk(KERN_INFO "zone%d=[", j); | |
78 | for (k = 0; k < conf->strip_zone[j].nb_dev; k++) | |
79 | printk(KERN_CONT "%s/", | |
80 | bdevname(conf->devlist[j*raid_disks | |
81 | + k]->bdev, b)); | |
82 | printk(KERN_CONT "]\n"); | |
83 | ||
84 | zone_size = conf->strip_zone[j].zone_end - zone_start; | |
85 | printk(KERN_INFO " zone offset=%llukb " | |
86 | "device offset=%llukb size=%llukb\n", | |
87 | (unsigned long long)zone_start>>1, | |
88 | (unsigned long long)conf->strip_zone[j].dev_start>>1, | |
89 | (unsigned long long)zone_size>>1); | |
90 | zone_start = conf->strip_zone[j].zone_end; | |
91 | } | |
92 | printk(KERN_INFO "**********************************\n\n"); | |
93 | } | |
94 | ||
95 | static int create_strip_zones(mddev_t *mddev, raid0_conf_t **private_conf) | |
96 | { | |
97 | int i, c, err; | |
98 | sector_t curr_zone_end, sectors; | |
99 | mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev, **dev; | |
100 | struct strip_zone *zone; | |
101 | int cnt; | |
102 | char b[BDEVNAME_SIZE]; | |
103 | raid0_conf_t *conf = kzalloc(sizeof(*conf), GFP_KERNEL); | |
104 | ||
105 | if (!conf) | |
106 | return -ENOMEM; | |
107 | list_for_each_entry(rdev1, &mddev->disks, same_set) { | |
108 | printk(KERN_INFO "md/raid0:%s: looking at %s\n", | |
109 | mdname(mddev), | |
110 | bdevname(rdev1->bdev, b)); | |
111 | c = 0; | |
112 | ||
113 | /* round size to chunk_size */ | |
114 | sectors = rdev1->sectors; | |
115 | sector_div(sectors, mddev->chunk_sectors); | |
116 | rdev1->sectors = sectors * mddev->chunk_sectors; | |
117 | ||
118 | list_for_each_entry(rdev2, &mddev->disks, same_set) { | |
119 | printk(KERN_INFO "md/raid0:%s: comparing %s(%llu)", | |
120 | mdname(mddev), | |
121 | bdevname(rdev1->bdev,b), | |
122 | (unsigned long long)rdev1->sectors); | |
123 | printk(KERN_CONT " with %s(%llu)\n", | |
124 | bdevname(rdev2->bdev,b), | |
125 | (unsigned long long)rdev2->sectors); | |
126 | if (rdev2 == rdev1) { | |
127 | printk(KERN_INFO "md/raid0:%s: END\n", | |
128 | mdname(mddev)); | |
129 | break; | |
130 | } | |
131 | if (rdev2->sectors == rdev1->sectors) { | |
132 | /* | |
133 | * Not unique, don't count it as a new | |
134 | * group | |
135 | */ | |
136 | printk(KERN_INFO "md/raid0:%s: EQUAL\n", | |
137 | mdname(mddev)); | |
138 | c = 1; | |
139 | break; | |
140 | } | |
141 | printk(KERN_INFO "md/raid0:%s: NOT EQUAL\n", | |
142 | mdname(mddev)); | |
143 | } | |
144 | if (!c) { | |
145 | printk(KERN_INFO "md/raid0:%s: ==> UNIQUE\n", | |
146 | mdname(mddev)); | |
147 | conf->nr_strip_zones++; | |
148 | printk(KERN_INFO "md/raid0:%s: %d zones\n", | |
149 | mdname(mddev), conf->nr_strip_zones); | |
150 | } | |
151 | } | |
152 | printk(KERN_INFO "md/raid0:%s: FINAL %d zones\n", | |
153 | mdname(mddev), conf->nr_strip_zones); | |
154 | err = -ENOMEM; | |
155 | conf->strip_zone = kzalloc(sizeof(struct strip_zone)* | |
156 | conf->nr_strip_zones, GFP_KERNEL); | |
157 | if (!conf->strip_zone) | |
158 | goto abort; | |
159 | conf->devlist = kzalloc(sizeof(mdk_rdev_t*)* | |
160 | conf->nr_strip_zones*mddev->raid_disks, | |
161 | GFP_KERNEL); | |
162 | if (!conf->devlist) | |
163 | goto abort; | |
164 | ||
165 | /* The first zone must contain all devices, so here we check that | |
166 | * there is a proper alignment of slots to devices and find them all | |
167 | */ | |
168 | zone = &conf->strip_zone[0]; | |
169 | cnt = 0; | |
170 | smallest = NULL; | |
171 | dev = conf->devlist; | |
172 | err = -EINVAL; | |
173 | list_for_each_entry(rdev1, &mddev->disks, same_set) { | |
174 | int j = rdev1->raid_disk; | |
175 | ||
176 | if (mddev->level == 10) { | |
177 | /* taking over a raid10-n2 array */ | |
178 | j /= 2; | |
179 | rdev1->new_raid_disk = j; | |
180 | } | |
181 | ||
182 | if (j < 0 || j >= mddev->raid_disks) { | |
183 | printk(KERN_ERR "md/raid0:%s: bad disk number %d - " | |
184 | "aborting!\n", mdname(mddev), j); | |
185 | goto abort; | |
186 | } | |
187 | if (dev[j]) { | |
188 | printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " | |
189 | "aborting!\n", mdname(mddev), j); | |
190 | goto abort; | |
191 | } | |
192 | dev[j] = rdev1; | |
193 | ||
194 | disk_stack_limits(mddev->gendisk, rdev1->bdev, | |
195 | rdev1->data_offset << 9); | |
196 | /* as we don't honour merge_bvec_fn, we must never risk | |
197 | * violating it, so limit ->max_segments to 1, lying within | |
198 | * a single page. | |
199 | */ | |
200 | ||
201 | if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) { | |
202 | blk_queue_max_segments(mddev->queue, 1); | |
203 | blk_queue_segment_boundary(mddev->queue, | |
204 | PAGE_CACHE_SIZE - 1); | |
205 | } | |
206 | if (!smallest || (rdev1->sectors < smallest->sectors)) | |
207 | smallest = rdev1; | |
208 | cnt++; | |
209 | } | |
210 | if (cnt != mddev->raid_disks) { | |
211 | printk(KERN_ERR "md/raid0:%s: too few disks (%d of %d) - " | |
212 | "aborting!\n", mdname(mddev), cnt, mddev->raid_disks); | |
213 | goto abort; | |
214 | } | |
215 | zone->nb_dev = cnt; | |
216 | zone->zone_end = smallest->sectors * cnt; | |
217 | ||
218 | curr_zone_end = zone->zone_end; | |
219 | ||
220 | /* now do the other zones */ | |
221 | for (i = 1; i < conf->nr_strip_zones; i++) | |
222 | { | |
223 | int j; | |
224 | ||
225 | zone = conf->strip_zone + i; | |
226 | dev = conf->devlist + i * mddev->raid_disks; | |
227 | ||
228 | printk(KERN_INFO "md/raid0:%s: zone %d\n", | |
229 | mdname(mddev), i); | |
230 | zone->dev_start = smallest->sectors; | |
231 | smallest = NULL; | |
232 | c = 0; | |
233 | ||
234 | for (j=0; j<cnt; j++) { | |
235 | rdev = conf->devlist[j]; | |
236 | printk(KERN_INFO "md/raid0:%s: checking %s ...", | |
237 | mdname(mddev), | |
238 | bdevname(rdev->bdev, b)); | |
239 | if (rdev->sectors <= zone->dev_start) { | |
240 | printk(KERN_CONT " nope.\n"); | |
241 | continue; | |
242 | } | |
243 | printk(KERN_CONT " contained as device %d\n", c); | |
244 | dev[c] = rdev; | |
245 | c++; | |
246 | if (!smallest || rdev->sectors < smallest->sectors) { | |
247 | smallest = rdev; | |
248 | printk(KERN_INFO "md/raid0:%s: (%llu) is smallest!.\n", | |
249 | mdname(mddev), | |
250 | (unsigned long long)rdev->sectors); | |
251 | } | |
252 | } | |
253 | ||
254 | zone->nb_dev = c; | |
255 | sectors = (smallest->sectors - zone->dev_start) * c; | |
256 | printk(KERN_INFO "md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", | |
257 | mdname(mddev), | |
258 | zone->nb_dev, (unsigned long long)sectors); | |
259 | ||
260 | curr_zone_end += sectors; | |
261 | zone->zone_end = curr_zone_end; | |
262 | ||
263 | printk(KERN_INFO "md/raid0:%s: current zone start: %llu\n", | |
264 | mdname(mddev), | |
265 | (unsigned long long)smallest->sectors); | |
266 | } | |
267 | mddev->queue->unplug_fn = raid0_unplug; | |
268 | mddev->queue->backing_dev_info.congested_fn = raid0_congested; | |
269 | mddev->queue->backing_dev_info.congested_data = mddev; | |
270 | ||
271 | /* | |
272 | * now since we have the hard sector sizes, we can make sure | |
273 | * chunk size is a multiple of that sector size | |
274 | */ | |
275 | if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) { | |
276 | printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", | |
277 | mdname(mddev), | |
278 | mddev->chunk_sectors << 9); | |
279 | goto abort; | |
280 | } | |
281 | ||
282 | blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); | |
283 | blk_queue_io_opt(mddev->queue, | |
284 | (mddev->chunk_sectors << 9) * mddev->raid_disks); | |
285 | ||
286 | printk(KERN_INFO "md/raid0:%s: done.\n", mdname(mddev)); | |
287 | *private_conf = conf; | |
288 | ||
289 | return 0; | |
290 | abort: | |
291 | kfree(conf->strip_zone); | |
292 | kfree(conf->devlist); | |
293 | kfree(conf); | |
294 | *private_conf = NULL; | |
295 | return err; | |
296 | } | |
297 | ||
298 | /** | |
299 | * raid0_mergeable_bvec -- tell bio layer if a two requests can be merged | |
300 | * @q: request queue | |
301 | * @bvm: properties of new bio | |
302 | * @biovec: the request that could be merged to it. | |
303 | * | |
304 | * Return amount of bytes we can accept at this offset | |
305 | */ | |
306 | static int raid0_mergeable_bvec(struct request_queue *q, | |
307 | struct bvec_merge_data *bvm, | |
308 | struct bio_vec *biovec) | |
309 | { | |
310 | mddev_t *mddev = q->queuedata; | |
311 | sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); | |
312 | int max; | |
313 | unsigned int chunk_sectors = mddev->chunk_sectors; | |
314 | unsigned int bio_sectors = bvm->bi_size >> 9; | |
315 | ||
316 | if (is_power_of_2(chunk_sectors)) | |
317 | max = (chunk_sectors - ((sector & (chunk_sectors-1)) | |
318 | + bio_sectors)) << 9; | |
319 | else | |
320 | max = (chunk_sectors - (sector_div(sector, chunk_sectors) | |
321 | + bio_sectors)) << 9; | |
322 | if (max < 0) max = 0; /* bio_add cannot handle a negative return */ | |
323 | if (max <= biovec->bv_len && bio_sectors == 0) | |
324 | return biovec->bv_len; | |
325 | else | |
326 | return max; | |
327 | } | |
328 | ||
329 | static sector_t raid0_size(mddev_t *mddev, sector_t sectors, int raid_disks) | |
330 | { | |
331 | sector_t array_sectors = 0; | |
332 | mdk_rdev_t *rdev; | |
333 | ||
334 | WARN_ONCE(sectors || raid_disks, | |
335 | "%s does not support generic reshape\n", __func__); | |
336 | ||
337 | list_for_each_entry(rdev, &mddev->disks, same_set) | |
338 | array_sectors += rdev->sectors; | |
339 | ||
340 | return array_sectors; | |
341 | } | |
342 | ||
343 | static int raid0_run(mddev_t *mddev) | |
344 | { | |
345 | raid0_conf_t *conf; | |
346 | int ret; | |
347 | ||
348 | if (mddev->chunk_sectors == 0) { | |
349 | printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", | |
350 | mdname(mddev)); | |
351 | return -EINVAL; | |
352 | } | |
353 | if (md_check_no_bitmap(mddev)) | |
354 | return -EINVAL; | |
355 | blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); | |
356 | mddev->queue->queue_lock = &mddev->queue->__queue_lock; | |
357 | ||
358 | /* if private is not null, we are here after takeover */ | |
359 | if (mddev->private == NULL) { | |
360 | ret = create_strip_zones(mddev, &conf); | |
361 | if (ret < 0) | |
362 | return ret; | |
363 | mddev->private = conf; | |
364 | } | |
365 | conf = mddev->private; | |
366 | ||
367 | /* calculate array device size */ | |
368 | md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); | |
369 | ||
370 | printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", | |
371 | mdname(mddev), | |
372 | (unsigned long long)mddev->array_sectors); | |
373 | /* calculate the max read-ahead size. | |
374 | * For read-ahead of large files to be effective, we need to | |
375 | * readahead at least twice a whole stripe. i.e. number of devices | |
376 | * multiplied by chunk size times 2. | |
377 | * If an individual device has an ra_pages greater than the | |
378 | * chunk size, then we will not drive that device as hard as it | |
379 | * wants. We consider this a configuration error: a larger | |
380 | * chunksize should be used in that case. | |
381 | */ | |
382 | { | |
383 | int stripe = mddev->raid_disks * | |
384 | (mddev->chunk_sectors << 9) / PAGE_SIZE; | |
385 | if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) | |
386 | mddev->queue->backing_dev_info.ra_pages = 2* stripe; | |
387 | } | |
388 | ||
389 | blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); | |
390 | dump_zones(mddev); | |
391 | md_integrity_register(mddev); | |
392 | return 0; | |
393 | } | |
394 | ||
395 | static int raid0_stop(mddev_t *mddev) | |
396 | { | |
397 | raid0_conf_t *conf = mddev->private; | |
398 | ||
399 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
400 | kfree(conf->strip_zone); | |
401 | kfree(conf->devlist); | |
402 | kfree(conf); | |
403 | mddev->private = NULL; | |
404 | return 0; | |
405 | } | |
406 | ||
407 | /* Find the zone which holds a particular offset | |
408 | * Update *sectorp to be an offset in that zone | |
409 | */ | |
410 | static struct strip_zone *find_zone(struct raid0_private_data *conf, | |
411 | sector_t *sectorp) | |
412 | { | |
413 | int i; | |
414 | struct strip_zone *z = conf->strip_zone; | |
415 | sector_t sector = *sectorp; | |
416 | ||
417 | for (i = 0; i < conf->nr_strip_zones; i++) | |
418 | if (sector < z[i].zone_end) { | |
419 | if (i) | |
420 | *sectorp = sector - z[i-1].zone_end; | |
421 | return z + i; | |
422 | } | |
423 | BUG(); | |
424 | } | |
425 | ||
426 | /* | |
427 | * remaps the bio to the target device. we separate two flows. | |
428 | * power 2 flow and a general flow for the sake of perfromance | |
429 | */ | |
430 | static mdk_rdev_t *map_sector(mddev_t *mddev, struct strip_zone *zone, | |
431 | sector_t sector, sector_t *sector_offset) | |
432 | { | |
433 | unsigned int sect_in_chunk; | |
434 | sector_t chunk; | |
435 | raid0_conf_t *conf = mddev->private; | |
436 | int raid_disks = conf->strip_zone[0].nb_dev; | |
437 | unsigned int chunk_sects = mddev->chunk_sectors; | |
438 | ||
439 | if (is_power_of_2(chunk_sects)) { | |
440 | int chunksect_bits = ffz(~chunk_sects); | |
441 | /* find the sector offset inside the chunk */ | |
442 | sect_in_chunk = sector & (chunk_sects - 1); | |
443 | sector >>= chunksect_bits; | |
444 | /* chunk in zone */ | |
445 | chunk = *sector_offset; | |
446 | /* quotient is the chunk in real device*/ | |
447 | sector_div(chunk, zone->nb_dev << chunksect_bits); | |
448 | } else{ | |
449 | sect_in_chunk = sector_div(sector, chunk_sects); | |
450 | chunk = *sector_offset; | |
451 | sector_div(chunk, chunk_sects * zone->nb_dev); | |
452 | } | |
453 | /* | |
454 | * position the bio over the real device | |
455 | * real sector = chunk in device + starting of zone | |
456 | * + the position in the chunk | |
457 | */ | |
458 | *sector_offset = (chunk * chunk_sects) + sect_in_chunk; | |
459 | return conf->devlist[(zone - conf->strip_zone)*raid_disks | |
460 | + sector_div(sector, zone->nb_dev)]; | |
461 | } | |
462 | ||
463 | /* | |
464 | * Is io distribute over 1 or more chunks ? | |
465 | */ | |
466 | static inline int is_io_in_chunk_boundary(mddev_t *mddev, | |
467 | unsigned int chunk_sects, struct bio *bio) | |
468 | { | |
469 | if (likely(is_power_of_2(chunk_sects))) { | |
470 | return chunk_sects >= ((bio->bi_sector & (chunk_sects-1)) | |
471 | + (bio->bi_size >> 9)); | |
472 | } else{ | |
473 | sector_t sector = bio->bi_sector; | |
474 | return chunk_sects >= (sector_div(sector, chunk_sects) | |
475 | + (bio->bi_size >> 9)); | |
476 | } | |
477 | } | |
478 | ||
479 | static int raid0_make_request(mddev_t *mddev, struct bio *bio) | |
480 | { | |
481 | unsigned int chunk_sects; | |
482 | sector_t sector_offset; | |
483 | struct strip_zone *zone; | |
484 | mdk_rdev_t *tmp_dev; | |
485 | ||
486 | if (unlikely(bio->bi_rw & REQ_HARDBARRIER)) { | |
487 | md_barrier_request(mddev, bio); | |
488 | return 0; | |
489 | } | |
490 | ||
491 | chunk_sects = mddev->chunk_sectors; | |
492 | if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) { | |
493 | sector_t sector = bio->bi_sector; | |
494 | struct bio_pair *bp; | |
495 | /* Sanity check -- queue functions should prevent this happening */ | |
496 | if (bio->bi_vcnt != 1 || | |
497 | bio->bi_idx != 0) | |
498 | goto bad_map; | |
499 | /* This is a one page bio that upper layers | |
500 | * refuse to split for us, so we need to split it. | |
501 | */ | |
502 | if (likely(is_power_of_2(chunk_sects))) | |
503 | bp = bio_split(bio, chunk_sects - (sector & | |
504 | (chunk_sects-1))); | |
505 | else | |
506 | bp = bio_split(bio, chunk_sects - | |
507 | sector_div(sector, chunk_sects)); | |
508 | if (raid0_make_request(mddev, &bp->bio1)) | |
509 | generic_make_request(&bp->bio1); | |
510 | if (raid0_make_request(mddev, &bp->bio2)) | |
511 | generic_make_request(&bp->bio2); | |
512 | ||
513 | bio_pair_release(bp); | |
514 | return 0; | |
515 | } | |
516 | ||
517 | sector_offset = bio->bi_sector; | |
518 | zone = find_zone(mddev->private, §or_offset); | |
519 | tmp_dev = map_sector(mddev, zone, bio->bi_sector, | |
520 | §or_offset); | |
521 | bio->bi_bdev = tmp_dev->bdev; | |
522 | bio->bi_sector = sector_offset + zone->dev_start + | |
523 | tmp_dev->data_offset; | |
524 | /* | |
525 | * Let the main block layer submit the IO and resolve recursion: | |
526 | */ | |
527 | return 1; | |
528 | ||
529 | bad_map: | |
530 | printk("md/raid0:%s: make_request bug: can't convert block across chunks" | |
531 | " or bigger than %dk %llu %d\n", | |
532 | mdname(mddev), chunk_sects / 2, | |
533 | (unsigned long long)bio->bi_sector, bio->bi_size >> 10); | |
534 | ||
535 | bio_io_error(bio); | |
536 | return 0; | |
537 | } | |
538 | ||
539 | static void raid0_status(struct seq_file *seq, mddev_t *mddev) | |
540 | { | |
541 | #undef MD_DEBUG | |
542 | #ifdef MD_DEBUG | |
543 | int j, k, h; | |
544 | char b[BDEVNAME_SIZE]; | |
545 | raid0_conf_t *conf = mddev->private; | |
546 | int raid_disks = conf->strip_zone[0].nb_dev; | |
547 | ||
548 | sector_t zone_size; | |
549 | sector_t zone_start = 0; | |
550 | h = 0; | |
551 | ||
552 | for (j = 0; j < conf->nr_strip_zones; j++) { | |
553 | seq_printf(seq, " z%d", j); | |
554 | seq_printf(seq, "=["); | |
555 | for (k = 0; k < conf->strip_zone[j].nb_dev; k++) | |
556 | seq_printf(seq, "%s/", bdevname( | |
557 | conf->devlist[j*raid_disks + k] | |
558 | ->bdev, b)); | |
559 | ||
560 | zone_size = conf->strip_zone[j].zone_end - zone_start; | |
561 | seq_printf(seq, "] ze=%lld ds=%lld s=%lld\n", | |
562 | (unsigned long long)zone_start>>1, | |
563 | (unsigned long long)conf->strip_zone[j].dev_start>>1, | |
564 | (unsigned long long)zone_size>>1); | |
565 | zone_start = conf->strip_zone[j].zone_end; | |
566 | } | |
567 | #endif | |
568 | seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); | |
569 | return; | |
570 | } | |
571 | ||
572 | static void *raid0_takeover_raid45(mddev_t *mddev) | |
573 | { | |
574 | mdk_rdev_t *rdev; | |
575 | raid0_conf_t *priv_conf; | |
576 | ||
577 | if (mddev->degraded != 1) { | |
578 | printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", | |
579 | mdname(mddev), | |
580 | mddev->degraded); | |
581 | return ERR_PTR(-EINVAL); | |
582 | } | |
583 | ||
584 | list_for_each_entry(rdev, &mddev->disks, same_set) { | |
585 | /* check slot number for a disk */ | |
586 | if (rdev->raid_disk == mddev->raid_disks-1) { | |
587 | printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n", | |
588 | mdname(mddev)); | |
589 | return ERR_PTR(-EINVAL); | |
590 | } | |
591 | } | |
592 | ||
593 | /* Set new parameters */ | |
594 | mddev->new_level = 0; | |
595 | mddev->new_layout = 0; | |
596 | mddev->new_chunk_sectors = mddev->chunk_sectors; | |
597 | mddev->raid_disks--; | |
598 | mddev->delta_disks = -1; | |
599 | /* make sure it will be not marked as dirty */ | |
600 | mddev->recovery_cp = MaxSector; | |
601 | ||
602 | create_strip_zones(mddev, &priv_conf); | |
603 | return priv_conf; | |
604 | } | |
605 | ||
606 | static void *raid0_takeover_raid10(mddev_t *mddev) | |
607 | { | |
608 | raid0_conf_t *priv_conf; | |
609 | ||
610 | /* Check layout: | |
611 | * - far_copies must be 1 | |
612 | * - near_copies must be 2 | |
613 | * - disks number must be even | |
614 | * - all mirrors must be already degraded | |
615 | */ | |
616 | if (mddev->layout != ((1 << 8) + 2)) { | |
617 | printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takover layout: 0x%x\n", | |
618 | mdname(mddev), | |
619 | mddev->layout); | |
620 | return ERR_PTR(-EINVAL); | |
621 | } | |
622 | if (mddev->raid_disks & 1) { | |
623 | printk(KERN_ERR "md/raid0:%s: Raid0 cannot takover Raid10 with odd disk number.\n", | |
624 | mdname(mddev)); | |
625 | return ERR_PTR(-EINVAL); | |
626 | } | |
627 | if (mddev->degraded != (mddev->raid_disks>>1)) { | |
628 | printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n", | |
629 | mdname(mddev)); | |
630 | return ERR_PTR(-EINVAL); | |
631 | } | |
632 | ||
633 | /* Set new parameters */ | |
634 | mddev->new_level = 0; | |
635 | mddev->new_layout = 0; | |
636 | mddev->new_chunk_sectors = mddev->chunk_sectors; | |
637 | mddev->delta_disks = - mddev->raid_disks / 2; | |
638 | mddev->raid_disks += mddev->delta_disks; | |
639 | mddev->degraded = 0; | |
640 | /* make sure it will be not marked as dirty */ | |
641 | mddev->recovery_cp = MaxSector; | |
642 | ||
643 | create_strip_zones(mddev, &priv_conf); | |
644 | return priv_conf; | |
645 | } | |
646 | ||
647 | static void *raid0_takeover(mddev_t *mddev) | |
648 | { | |
649 | /* raid0 can take over: | |
650 | * raid4 - if all data disks are active. | |
651 | * raid5 - providing it is Raid4 layout and one disk is faulty | |
652 | * raid10 - assuming we have all necessary active disks | |
653 | */ | |
654 | if (mddev->level == 4) | |
655 | return raid0_takeover_raid45(mddev); | |
656 | ||
657 | if (mddev->level == 5) { | |
658 | if (mddev->layout == ALGORITHM_PARITY_N) | |
659 | return raid0_takeover_raid45(mddev); | |
660 | ||
661 | printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", | |
662 | mdname(mddev), ALGORITHM_PARITY_N); | |
663 | } | |
664 | ||
665 | if (mddev->level == 10) | |
666 | return raid0_takeover_raid10(mddev); | |
667 | ||
668 | return ERR_PTR(-EINVAL); | |
669 | } | |
670 | ||
671 | static void raid0_quiesce(mddev_t *mddev, int state) | |
672 | { | |
673 | } | |
674 | ||
675 | static struct mdk_personality raid0_personality= | |
676 | { | |
677 | .name = "raid0", | |
678 | .level = 0, | |
679 | .owner = THIS_MODULE, | |
680 | .make_request = raid0_make_request, | |
681 | .run = raid0_run, | |
682 | .stop = raid0_stop, | |
683 | .status = raid0_status, | |
684 | .size = raid0_size, | |
685 | .takeover = raid0_takeover, | |
686 | .quiesce = raid0_quiesce, | |
687 | }; | |
688 | ||
689 | static int __init raid0_init (void) | |
690 | { | |
691 | return register_md_personality (&raid0_personality); | |
692 | } | |
693 | ||
694 | static void raid0_exit (void) | |
695 | { | |
696 | unregister_md_personality (&raid0_personality); | |
697 | } | |
698 | ||
699 | module_init(raid0_init); | |
700 | module_exit(raid0_exit); | |
701 | MODULE_LICENSE("GPL"); | |
702 | MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); | |
703 | MODULE_ALIAS("md-personality-2"); /* RAID0 */ | |
704 | MODULE_ALIAS("md-raid0"); | |
705 | MODULE_ALIAS("md-level-0"); |