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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 | RAID-0 management functions. | |
9 | ||
10 | This program is free software; you can redistribute it and/or modify | |
11 | it under the terms of the GNU General Public License as published by | |
12 | the Free Software Foundation; either version 2, or (at your option) | |
13 | any later version. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | (for example /usr/src/linux/COPYING); if not, write to the Free | |
17 | Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
18 | */ | |
19 | ||
20 | #include <linux/blkdev.h> | |
21 | #include <linux/seq_file.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/slab.h> | |
24 | #include "md.h" | |
25 | #include "raid0.h" | |
26 | #include "raid5.h" | |
27 | ||
28 | static int raid0_congested(struct mddev *mddev, int bits) | |
29 | { | |
30 | struct r0conf *conf = mddev->private; | |
31 | struct md_rdev **devlist = conf->devlist; | |
32 | int raid_disks = conf->strip_zone[0].nb_dev; | |
33 | int i, ret = 0; | |
34 | ||
35 | for (i = 0; i < raid_disks && !ret ; i++) { | |
36 | struct request_queue *q = bdev_get_queue(devlist[i]->bdev); | |
37 | ||
38 | ret |= bdi_congested(&q->backing_dev_info, bits); | |
39 | } | |
40 | return ret; | |
41 | } | |
42 | ||
43 | /* | |
44 | * inform the user of the raid configuration | |
45 | */ | |
46 | static void dump_zones(struct mddev *mddev) | |
47 | { | |
48 | int j, k; | |
49 | sector_t zone_size = 0; | |
50 | sector_t zone_start = 0; | |
51 | char b[BDEVNAME_SIZE]; | |
52 | struct r0conf *conf = mddev->private; | |
53 | int raid_disks = conf->strip_zone[0].nb_dev; | |
54 | printk(KERN_INFO "md: RAID0 configuration for %s - %d zone%s\n", | |
55 | mdname(mddev), | |
56 | conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s"); | |
57 | for (j = 0; j < conf->nr_strip_zones; j++) { | |
58 | printk(KERN_INFO "md: zone%d=[", j); | |
59 | for (k = 0; k < conf->strip_zone[j].nb_dev; k++) | |
60 | printk(KERN_CONT "%s%s", k?"/":"", | |
61 | bdevname(conf->devlist[j*raid_disks | |
62 | + k]->bdev, b)); | |
63 | printk(KERN_CONT "]\n"); | |
64 | ||
65 | zone_size = conf->strip_zone[j].zone_end - zone_start; | |
66 | printk(KERN_INFO " zone-offset=%10lluKB, " | |
67 | "device-offset=%10lluKB, size=%10lluKB\n", | |
68 | (unsigned long long)zone_start>>1, | |
69 | (unsigned long long)conf->strip_zone[j].dev_start>>1, | |
70 | (unsigned long long)zone_size>>1); | |
71 | zone_start = conf->strip_zone[j].zone_end; | |
72 | } | |
73 | } | |
74 | ||
75 | static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) | |
76 | { | |
77 | int i, c, err; | |
78 | sector_t curr_zone_end, sectors; | |
79 | struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; | |
80 | struct strip_zone *zone; | |
81 | int cnt; | |
82 | char b[BDEVNAME_SIZE]; | |
83 | char b2[BDEVNAME_SIZE]; | |
84 | struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); | |
85 | unsigned short blksize = 512; | |
86 | ||
87 | *private_conf = ERR_PTR(-ENOMEM); | |
88 | if (!conf) | |
89 | return -ENOMEM; | |
90 | rdev_for_each(rdev1, mddev) { | |
91 | pr_debug("md/raid0:%s: looking at %s\n", | |
92 | mdname(mddev), | |
93 | bdevname(rdev1->bdev, b)); | |
94 | c = 0; | |
95 | ||
96 | /* round size to chunk_size */ | |
97 | sectors = rdev1->sectors; | |
98 | sector_div(sectors, mddev->chunk_sectors); | |
99 | rdev1->sectors = sectors * mddev->chunk_sectors; | |
100 | ||
101 | blksize = max(blksize, queue_logical_block_size( | |
102 | rdev1->bdev->bd_disk->queue)); | |
103 | ||
104 | rdev_for_each(rdev2, mddev) { | |
105 | pr_debug("md/raid0:%s: comparing %s(%llu)" | |
106 | " with %s(%llu)\n", | |
107 | mdname(mddev), | |
108 | bdevname(rdev1->bdev,b), | |
109 | (unsigned long long)rdev1->sectors, | |
110 | bdevname(rdev2->bdev,b2), | |
111 | (unsigned long long)rdev2->sectors); | |
112 | if (rdev2 == rdev1) { | |
113 | pr_debug("md/raid0:%s: END\n", | |
114 | mdname(mddev)); | |
115 | break; | |
116 | } | |
117 | if (rdev2->sectors == rdev1->sectors) { | |
118 | /* | |
119 | * Not unique, don't count it as a new | |
120 | * group | |
121 | */ | |
122 | pr_debug("md/raid0:%s: EQUAL\n", | |
123 | mdname(mddev)); | |
124 | c = 1; | |
125 | break; | |
126 | } | |
127 | pr_debug("md/raid0:%s: NOT EQUAL\n", | |
128 | mdname(mddev)); | |
129 | } | |
130 | if (!c) { | |
131 | pr_debug("md/raid0:%s: ==> UNIQUE\n", | |
132 | mdname(mddev)); | |
133 | conf->nr_strip_zones++; | |
134 | pr_debug("md/raid0:%s: %d zones\n", | |
135 | mdname(mddev), conf->nr_strip_zones); | |
136 | } | |
137 | } | |
138 | pr_debug("md/raid0:%s: FINAL %d zones\n", | |
139 | mdname(mddev), conf->nr_strip_zones); | |
140 | /* | |
141 | * now since we have the hard sector sizes, we can make sure | |
142 | * chunk size is a multiple of that sector size | |
143 | */ | |
144 | if ((mddev->chunk_sectors << 9) % blksize) { | |
145 | printk(KERN_ERR "md/raid0:%s: chunk_size of %d not multiple of block size %d\n", | |
146 | mdname(mddev), | |
147 | mddev->chunk_sectors << 9, blksize); | |
148 | err = -EINVAL; | |
149 | goto abort; | |
150 | } | |
151 | ||
152 | err = -ENOMEM; | |
153 | conf->strip_zone = kzalloc(sizeof(struct strip_zone)* | |
154 | conf->nr_strip_zones, GFP_KERNEL); | |
155 | if (!conf->strip_zone) | |
156 | goto abort; | |
157 | conf->devlist = kzalloc(sizeof(struct md_rdev*)* | |
158 | conf->nr_strip_zones*mddev->raid_disks, | |
159 | GFP_KERNEL); | |
160 | if (!conf->devlist) | |
161 | goto abort; | |
162 | ||
163 | /* The first zone must contain all devices, so here we check that | |
164 | * there is a proper alignment of slots to devices and find them all | |
165 | */ | |
166 | zone = &conf->strip_zone[0]; | |
167 | cnt = 0; | |
168 | smallest = NULL; | |
169 | dev = conf->devlist; | |
170 | err = -EINVAL; | |
171 | rdev_for_each(rdev1, mddev) { | |
172 | int j = rdev1->raid_disk; | |
173 | ||
174 | if (mddev->level == 10) { | |
175 | /* taking over a raid10-n2 array */ | |
176 | j /= 2; | |
177 | rdev1->new_raid_disk = j; | |
178 | } | |
179 | ||
180 | if (mddev->level == 1) { | |
181 | /* taiking over a raid1 array- | |
182 | * we have only one active disk | |
183 | */ | |
184 | j = 0; | |
185 | rdev1->new_raid_disk = j; | |
186 | } | |
187 | ||
188 | if (j < 0) { | |
189 | printk(KERN_ERR | |
190 | "md/raid0:%s: remove inactive devices before converting to RAID0\n", | |
191 | mdname(mddev)); | |
192 | goto abort; | |
193 | } | |
194 | if (j >= mddev->raid_disks) { | |
195 | printk(KERN_ERR "md/raid0:%s: bad disk number %d - " | |
196 | "aborting!\n", mdname(mddev), j); | |
197 | goto abort; | |
198 | } | |
199 | if (dev[j]) { | |
200 | printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " | |
201 | "aborting!\n", mdname(mddev), j); | |
202 | goto abort; | |
203 | } | |
204 | dev[j] = rdev1; | |
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 | pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); | |
229 | zone->dev_start = smallest->sectors; | |
230 | smallest = NULL; | |
231 | c = 0; | |
232 | ||
233 | for (j=0; j<cnt; j++) { | |
234 | rdev = conf->devlist[j]; | |
235 | if (rdev->sectors <= zone->dev_start) { | |
236 | pr_debug("md/raid0:%s: checking %s ... nope\n", | |
237 | mdname(mddev), | |
238 | bdevname(rdev->bdev, b)); | |
239 | continue; | |
240 | } | |
241 | pr_debug("md/raid0:%s: checking %s ..." | |
242 | " contained as device %d\n", | |
243 | mdname(mddev), | |
244 | bdevname(rdev->bdev, b), c); | |
245 | dev[c] = rdev; | |
246 | c++; | |
247 | if (!smallest || rdev->sectors < smallest->sectors) { | |
248 | smallest = rdev; | |
249 | pr_debug("md/raid0:%s: (%llu) is smallest!.\n", | |
250 | mdname(mddev), | |
251 | (unsigned long long)rdev->sectors); | |
252 | } | |
253 | } | |
254 | ||
255 | zone->nb_dev = c; | |
256 | sectors = (smallest->sectors - zone->dev_start) * c; | |
257 | pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", | |
258 | mdname(mddev), | |
259 | zone->nb_dev, (unsigned long long)sectors); | |
260 | ||
261 | curr_zone_end += sectors; | |
262 | zone->zone_end = curr_zone_end; | |
263 | ||
264 | pr_debug("md/raid0:%s: current zone start: %llu\n", | |
265 | mdname(mddev), | |
266 | (unsigned long long)smallest->sectors); | |
267 | } | |
268 | ||
269 | pr_debug("md/raid0:%s: done.\n", mdname(mddev)); | |
270 | *private_conf = conf; | |
271 | ||
272 | return 0; | |
273 | abort: | |
274 | kfree(conf->strip_zone); | |
275 | kfree(conf->devlist); | |
276 | kfree(conf); | |
277 | *private_conf = ERR_PTR(err); | |
278 | return err; | |
279 | } | |
280 | ||
281 | /* Find the zone which holds a particular offset | |
282 | * Update *sectorp to be an offset in that zone | |
283 | */ | |
284 | static struct strip_zone *find_zone(struct r0conf *conf, | |
285 | sector_t *sectorp) | |
286 | { | |
287 | int i; | |
288 | struct strip_zone *z = conf->strip_zone; | |
289 | sector_t sector = *sectorp; | |
290 | ||
291 | for (i = 0; i < conf->nr_strip_zones; i++) | |
292 | if (sector < z[i].zone_end) { | |
293 | if (i) | |
294 | *sectorp = sector - z[i-1].zone_end; | |
295 | return z + i; | |
296 | } | |
297 | BUG(); | |
298 | } | |
299 | ||
300 | /* | |
301 | * remaps the bio to the target device. we separate two flows. | |
302 | * power 2 flow and a general flow for the sake of performance | |
303 | */ | |
304 | static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, | |
305 | sector_t sector, sector_t *sector_offset) | |
306 | { | |
307 | unsigned int sect_in_chunk; | |
308 | sector_t chunk; | |
309 | struct r0conf *conf = mddev->private; | |
310 | int raid_disks = conf->strip_zone[0].nb_dev; | |
311 | unsigned int chunk_sects = mddev->chunk_sectors; | |
312 | ||
313 | if (is_power_of_2(chunk_sects)) { | |
314 | int chunksect_bits = ffz(~chunk_sects); | |
315 | /* find the sector offset inside the chunk */ | |
316 | sect_in_chunk = sector & (chunk_sects - 1); | |
317 | sector >>= chunksect_bits; | |
318 | /* chunk in zone */ | |
319 | chunk = *sector_offset; | |
320 | /* quotient is the chunk in real device*/ | |
321 | sector_div(chunk, zone->nb_dev << chunksect_bits); | |
322 | } else{ | |
323 | sect_in_chunk = sector_div(sector, chunk_sects); | |
324 | chunk = *sector_offset; | |
325 | sector_div(chunk, chunk_sects * zone->nb_dev); | |
326 | } | |
327 | /* | |
328 | * position the bio over the real device | |
329 | * real sector = chunk in device + starting of zone | |
330 | * + the position in the chunk | |
331 | */ | |
332 | *sector_offset = (chunk * chunk_sects) + sect_in_chunk; | |
333 | return conf->devlist[(zone - conf->strip_zone)*raid_disks | |
334 | + sector_div(sector, zone->nb_dev)]; | |
335 | } | |
336 | ||
337 | static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) | |
338 | { | |
339 | sector_t array_sectors = 0; | |
340 | struct md_rdev *rdev; | |
341 | ||
342 | WARN_ONCE(sectors || raid_disks, | |
343 | "%s does not support generic reshape\n", __func__); | |
344 | ||
345 | rdev_for_each(rdev, mddev) | |
346 | array_sectors += (rdev->sectors & | |
347 | ~(sector_t)(mddev->chunk_sectors-1)); | |
348 | ||
349 | return array_sectors; | |
350 | } | |
351 | ||
352 | static void raid0_free(struct mddev *mddev, void *priv); | |
353 | ||
354 | static int raid0_run(struct mddev *mddev) | |
355 | { | |
356 | struct r0conf *conf; | |
357 | int ret; | |
358 | ||
359 | if (mddev->chunk_sectors == 0) { | |
360 | printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", | |
361 | mdname(mddev)); | |
362 | return -EINVAL; | |
363 | } | |
364 | if (md_check_no_bitmap(mddev)) | |
365 | return -EINVAL; | |
366 | ||
367 | /* if private is not null, we are here after takeover */ | |
368 | if (mddev->private == NULL) { | |
369 | ret = create_strip_zones(mddev, &conf); | |
370 | if (ret < 0) | |
371 | return ret; | |
372 | mddev->private = conf; | |
373 | } | |
374 | conf = mddev->private; | |
375 | if (mddev->queue) { | |
376 | struct md_rdev *rdev; | |
377 | bool discard_supported = false; | |
378 | ||
379 | blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); | |
380 | blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors); | |
381 | blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors); | |
382 | ||
383 | blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); | |
384 | blk_queue_io_opt(mddev->queue, | |
385 | (mddev->chunk_sectors << 9) * mddev->raid_disks); | |
386 | ||
387 | rdev_for_each(rdev, mddev) { | |
388 | disk_stack_limits(mddev->gendisk, rdev->bdev, | |
389 | rdev->data_offset << 9); | |
390 | if (blk_queue_discard(bdev_get_queue(rdev->bdev))) | |
391 | discard_supported = true; | |
392 | } | |
393 | if (!discard_supported) | |
394 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); | |
395 | else | |
396 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); | |
397 | } | |
398 | ||
399 | /* calculate array device size */ | |
400 | md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); | |
401 | ||
402 | printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", | |
403 | mdname(mddev), | |
404 | (unsigned long long)mddev->array_sectors); | |
405 | ||
406 | if (mddev->queue) { | |
407 | /* calculate the max read-ahead size. | |
408 | * For read-ahead of large files to be effective, we need to | |
409 | * readahead at least twice a whole stripe. i.e. number of devices | |
410 | * multiplied by chunk size times 2. | |
411 | * If an individual device has an ra_pages greater than the | |
412 | * chunk size, then we will not drive that device as hard as it | |
413 | * wants. We consider this a configuration error: a larger | |
414 | * chunksize should be used in that case. | |
415 | */ | |
416 | int stripe = mddev->raid_disks * | |
417 | (mddev->chunk_sectors << 9) / PAGE_SIZE; | |
418 | if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) | |
419 | mddev->queue->backing_dev_info.ra_pages = 2* stripe; | |
420 | } | |
421 | ||
422 | dump_zones(mddev); | |
423 | ||
424 | ret = md_integrity_register(mddev); | |
425 | ||
426 | return ret; | |
427 | } | |
428 | ||
429 | static void raid0_free(struct mddev *mddev, void *priv) | |
430 | { | |
431 | struct r0conf *conf = priv; | |
432 | ||
433 | kfree(conf->strip_zone); | |
434 | kfree(conf->devlist); | |
435 | kfree(conf); | |
436 | } | |
437 | ||
438 | /* | |
439 | * Is io distribute over 1 or more chunks ? | |
440 | */ | |
441 | static inline int is_io_in_chunk_boundary(struct mddev *mddev, | |
442 | unsigned int chunk_sects, struct bio *bio) | |
443 | { | |
444 | if (likely(is_power_of_2(chunk_sects))) { | |
445 | return chunk_sects >= | |
446 | ((bio->bi_iter.bi_sector & (chunk_sects-1)) | |
447 | + bio_sectors(bio)); | |
448 | } else{ | |
449 | sector_t sector = bio->bi_iter.bi_sector; | |
450 | return chunk_sects >= (sector_div(sector, chunk_sects) | |
451 | + bio_sectors(bio)); | |
452 | } | |
453 | } | |
454 | ||
455 | static void raid0_make_request(struct mddev *mddev, struct bio *bio) | |
456 | { | |
457 | struct strip_zone *zone; | |
458 | struct md_rdev *tmp_dev; | |
459 | struct bio *split; | |
460 | ||
461 | if (unlikely(bio->bi_rw & REQ_FLUSH)) { | |
462 | md_flush_request(mddev, bio); | |
463 | return; | |
464 | } | |
465 | ||
466 | do { | |
467 | sector_t sector = bio->bi_iter.bi_sector; | |
468 | unsigned chunk_sects = mddev->chunk_sectors; | |
469 | ||
470 | unsigned sectors = chunk_sects - | |
471 | (likely(is_power_of_2(chunk_sects)) | |
472 | ? (sector & (chunk_sects-1)) | |
473 | : sector_div(sector, chunk_sects)); | |
474 | ||
475 | /* Restore due to sector_div */ | |
476 | sector = bio->bi_iter.bi_sector; | |
477 | ||
478 | if (sectors < bio_sectors(bio)) { | |
479 | split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set); | |
480 | bio_chain(split, bio); | |
481 | } else { | |
482 | split = bio; | |
483 | } | |
484 | ||
485 | zone = find_zone(mddev->private, §or); | |
486 | tmp_dev = map_sector(mddev, zone, sector, §or); | |
487 | split->bi_bdev = tmp_dev->bdev; | |
488 | split->bi_iter.bi_sector = sector + zone->dev_start + | |
489 | tmp_dev->data_offset; | |
490 | ||
491 | if (unlikely((split->bi_rw & REQ_DISCARD) && | |
492 | !blk_queue_discard(bdev_get_queue(split->bi_bdev)))) { | |
493 | /* Just ignore it */ | |
494 | bio_endio(split); | |
495 | } else | |
496 | generic_make_request(split); | |
497 | } while (split != bio); | |
498 | } | |
499 | ||
500 | static void raid0_status(struct seq_file *seq, struct mddev *mddev) | |
501 | { | |
502 | seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); | |
503 | return; | |
504 | } | |
505 | ||
506 | static void *raid0_takeover_raid45(struct mddev *mddev) | |
507 | { | |
508 | struct md_rdev *rdev; | |
509 | struct r0conf *priv_conf; | |
510 | ||
511 | if (mddev->degraded != 1) { | |
512 | printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", | |
513 | mdname(mddev), | |
514 | mddev->degraded); | |
515 | return ERR_PTR(-EINVAL); | |
516 | } | |
517 | ||
518 | rdev_for_each(rdev, mddev) { | |
519 | /* check slot number for a disk */ | |
520 | if (rdev->raid_disk == mddev->raid_disks-1) { | |
521 | printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n", | |
522 | mdname(mddev)); | |
523 | return ERR_PTR(-EINVAL); | |
524 | } | |
525 | rdev->sectors = mddev->dev_sectors; | |
526 | } | |
527 | ||
528 | /* Set new parameters */ | |
529 | mddev->new_level = 0; | |
530 | mddev->new_layout = 0; | |
531 | mddev->new_chunk_sectors = mddev->chunk_sectors; | |
532 | mddev->raid_disks--; | |
533 | mddev->delta_disks = -1; | |
534 | /* make sure it will be not marked as dirty */ | |
535 | mddev->recovery_cp = MaxSector; | |
536 | ||
537 | create_strip_zones(mddev, &priv_conf); | |
538 | return priv_conf; | |
539 | } | |
540 | ||
541 | static void *raid0_takeover_raid10(struct mddev *mddev) | |
542 | { | |
543 | struct r0conf *priv_conf; | |
544 | ||
545 | /* Check layout: | |
546 | * - far_copies must be 1 | |
547 | * - near_copies must be 2 | |
548 | * - disks number must be even | |
549 | * - all mirrors must be already degraded | |
550 | */ | |
551 | if (mddev->layout != ((1 << 8) + 2)) { | |
552 | printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n", | |
553 | mdname(mddev), | |
554 | mddev->layout); | |
555 | return ERR_PTR(-EINVAL); | |
556 | } | |
557 | if (mddev->raid_disks & 1) { | |
558 | printk(KERN_ERR "md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n", | |
559 | mdname(mddev)); | |
560 | return ERR_PTR(-EINVAL); | |
561 | } | |
562 | if (mddev->degraded != (mddev->raid_disks>>1)) { | |
563 | printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n", | |
564 | mdname(mddev)); | |
565 | return ERR_PTR(-EINVAL); | |
566 | } | |
567 | ||
568 | /* Set new parameters */ | |
569 | mddev->new_level = 0; | |
570 | mddev->new_layout = 0; | |
571 | mddev->new_chunk_sectors = mddev->chunk_sectors; | |
572 | mddev->delta_disks = - mddev->raid_disks / 2; | |
573 | mddev->raid_disks += mddev->delta_disks; | |
574 | mddev->degraded = 0; | |
575 | /* make sure it will be not marked as dirty */ | |
576 | mddev->recovery_cp = MaxSector; | |
577 | ||
578 | create_strip_zones(mddev, &priv_conf); | |
579 | return priv_conf; | |
580 | } | |
581 | ||
582 | static void *raid0_takeover_raid1(struct mddev *mddev) | |
583 | { | |
584 | struct r0conf *priv_conf; | |
585 | int chunksect; | |
586 | ||
587 | /* Check layout: | |
588 | * - (N - 1) mirror drives must be already faulty | |
589 | */ | |
590 | if ((mddev->raid_disks - 1) != mddev->degraded) { | |
591 | printk(KERN_ERR "md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n", | |
592 | mdname(mddev)); | |
593 | return ERR_PTR(-EINVAL); | |
594 | } | |
595 | ||
596 | /* | |
597 | * a raid1 doesn't have the notion of chunk size, so | |
598 | * figure out the largest suitable size we can use. | |
599 | */ | |
600 | chunksect = 64 * 2; /* 64K by default */ | |
601 | ||
602 | /* The array must be an exact multiple of chunksize */ | |
603 | while (chunksect && (mddev->array_sectors & (chunksect - 1))) | |
604 | chunksect >>= 1; | |
605 | ||
606 | if ((chunksect << 9) < PAGE_SIZE) | |
607 | /* array size does not allow a suitable chunk size */ | |
608 | return ERR_PTR(-EINVAL); | |
609 | ||
610 | /* Set new parameters */ | |
611 | mddev->new_level = 0; | |
612 | mddev->new_layout = 0; | |
613 | mddev->new_chunk_sectors = chunksect; | |
614 | mddev->chunk_sectors = chunksect; | |
615 | mddev->delta_disks = 1 - mddev->raid_disks; | |
616 | mddev->raid_disks = 1; | |
617 | /* make sure it will be not marked as dirty */ | |
618 | mddev->recovery_cp = MaxSector; | |
619 | ||
620 | create_strip_zones(mddev, &priv_conf); | |
621 | return priv_conf; | |
622 | } | |
623 | ||
624 | static void *raid0_takeover(struct mddev *mddev) | |
625 | { | |
626 | /* raid0 can take over: | |
627 | * raid4 - if all data disks are active. | |
628 | * raid5 - providing it is Raid4 layout and one disk is faulty | |
629 | * raid10 - assuming we have all necessary active disks | |
630 | * raid1 - with (N -1) mirror drives faulty | |
631 | */ | |
632 | ||
633 | if (mddev->bitmap) { | |
634 | printk(KERN_ERR "md/raid0: %s: cannot takeover array with bitmap\n", | |
635 | mdname(mddev)); | |
636 | return ERR_PTR(-EBUSY); | |
637 | } | |
638 | if (mddev->level == 4) | |
639 | return raid0_takeover_raid45(mddev); | |
640 | ||
641 | if (mddev->level == 5) { | |
642 | if (mddev->layout == ALGORITHM_PARITY_N) | |
643 | return raid0_takeover_raid45(mddev); | |
644 | ||
645 | printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", | |
646 | mdname(mddev), ALGORITHM_PARITY_N); | |
647 | } | |
648 | ||
649 | if (mddev->level == 10) | |
650 | return raid0_takeover_raid10(mddev); | |
651 | ||
652 | if (mddev->level == 1) | |
653 | return raid0_takeover_raid1(mddev); | |
654 | ||
655 | printk(KERN_ERR "Takeover from raid%i to raid0 not supported\n", | |
656 | mddev->level); | |
657 | ||
658 | return ERR_PTR(-EINVAL); | |
659 | } | |
660 | ||
661 | static void raid0_quiesce(struct mddev *mddev, int state) | |
662 | { | |
663 | } | |
664 | ||
665 | static struct md_personality raid0_personality= | |
666 | { | |
667 | .name = "raid0", | |
668 | .level = 0, | |
669 | .owner = THIS_MODULE, | |
670 | .make_request = raid0_make_request, | |
671 | .run = raid0_run, | |
672 | .free = raid0_free, | |
673 | .status = raid0_status, | |
674 | .size = raid0_size, | |
675 | .takeover = raid0_takeover, | |
676 | .quiesce = raid0_quiesce, | |
677 | .congested = raid0_congested, | |
678 | }; | |
679 | ||
680 | static int __init raid0_init (void) | |
681 | { | |
682 | return register_md_personality (&raid0_personality); | |
683 | } | |
684 | ||
685 | static void raid0_exit (void) | |
686 | { | |
687 | unregister_md_personality (&raid0_personality); | |
688 | } | |
689 | ||
690 | module_init(raid0_init); | |
691 | module_exit(raid0_exit); | |
692 | MODULE_LICENSE("GPL"); | |
693 | MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); | |
694 | MODULE_ALIAS("md-personality-2"); /* RAID0 */ | |
695 | MODULE_ALIAS("md-raid0"); | |
696 | MODULE_ALIAS("md-level-0"); |