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1da177e4 LT |
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 | ||
bff61975 | 21 | #include <linux/blkdev.h> |
bff61975 | 22 | #include <linux/seq_file.h> |
5a0e3ad6 | 23 | #include <linux/slab.h> |
43b2e5d8 | 24 | #include "md.h" |
ef740c37 | 25 | #include "raid0.h" |
9af204cf | 26 | #include "raid5.h" |
1da177e4 | 27 | |
165125e1 | 28 | static void raid0_unplug(struct request_queue *q) |
1da177e4 LT |
29 | { |
30 | mddev_t *mddev = q->queuedata; | |
070ec55d | 31 | raid0_conf_t *conf = mddev->private; |
b414579f | 32 | mdk_rdev_t **devlist = conf->devlist; |
84707f38 | 33 | int raid_disks = conf->strip_zone[0].nb_dev; |
1da177e4 LT |
34 | int i; |
35 | ||
84707f38 | 36 | for (i=0; i < raid_disks; i++) { |
165125e1 | 37 | struct request_queue *r_queue = bdev_get_queue(devlist[i]->bdev); |
1da177e4 | 38 | |
2ad8b1ef | 39 | blk_unplug(r_queue); |
1da177e4 LT |
40 | } |
41 | } | |
42 | ||
26be34dc N |
43 | static int raid0_congested(void *data, int bits) |
44 | { | |
45 | mddev_t *mddev = data; | |
070ec55d | 46 | raid0_conf_t *conf = mddev->private; |
b414579f | 47 | mdk_rdev_t **devlist = conf->devlist; |
84707f38 | 48 | int raid_disks = conf->strip_zone[0].nb_dev; |
26be34dc N |
49 | int i, ret = 0; |
50 | ||
3fa841d7 N |
51 | if (mddev_congested(mddev, bits)) |
52 | return 1; | |
53 | ||
84707f38 | 54 | for (i = 0; i < raid_disks && !ret ; i++) { |
165125e1 | 55 | struct request_queue *q = bdev_get_queue(devlist[i]->bdev); |
26be34dc N |
56 | |
57 | ret |= bdi_congested(&q->backing_dev_info, bits); | |
58 | } | |
59 | return ret; | |
60 | } | |
61 | ||
46994191 | 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; | |
84707f38 | 72 | int raid_disks = conf->strip_zone[0].nb_dev; |
46994191 | 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++) | |
b5a20961 | 79 | printk(KERN_CONT "%s/", |
84707f38 | 80 | bdevname(conf->devlist[j*raid_disks |
46994191 | 81 | + k]->bdev, b)); |
b5a20961 | 82 | printk(KERN_CONT "]\n"); |
46994191 | 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 | ||
9af204cf | 95 | static int create_strip_zones(mddev_t *mddev, raid0_conf_t **private_conf) |
1da177e4 | 96 | { |
a9f326eb | 97 | int i, c, err; |
49f357a2 | 98 | sector_t curr_zone_end, sectors; |
b414579f | 99 | mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev, **dev; |
1da177e4 LT |
100 | struct strip_zone *zone; |
101 | int cnt; | |
102 | char b[BDEVNAME_SIZE]; | |
ed7b0038 AN |
103 | raid0_conf_t *conf = kzalloc(sizeof(*conf), GFP_KERNEL); |
104 | ||
105 | if (!conf) | |
106 | return -ENOMEM; | |
159ec1fc | 107 | list_for_each_entry(rdev1, &mddev->disks, same_set) { |
b5a20961 N |
108 | printk(KERN_INFO "md/raid0:%s: looking at %s\n", |
109 | mdname(mddev), | |
110 | bdevname(rdev1->bdev, b)); | |
1da177e4 | 111 | c = 0; |
13f2682b N |
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 | ||
159ec1fc | 118 | list_for_each_entry(rdev2, &mddev->disks, same_set) { |
b5a20961 N |
119 | printk(KERN_INFO "md/raid0:%s: comparing %s(%llu)", |
120 | mdname(mddev), | |
1da177e4 | 121 | bdevname(rdev1->bdev,b), |
dd8ac336 | 122 | (unsigned long long)rdev1->sectors); |
b5a20961 | 123 | printk(KERN_CONT " with %s(%llu)\n", |
1da177e4 | 124 | bdevname(rdev2->bdev,b), |
dd8ac336 | 125 | (unsigned long long)rdev2->sectors); |
1da177e4 | 126 | if (rdev2 == rdev1) { |
b5a20961 N |
127 | printk(KERN_INFO "md/raid0:%s: END\n", |
128 | mdname(mddev)); | |
1da177e4 LT |
129 | break; |
130 | } | |
dd8ac336 | 131 | if (rdev2->sectors == rdev1->sectors) { |
1da177e4 LT |
132 | /* |
133 | * Not unique, don't count it as a new | |
134 | * group | |
135 | */ | |
b5a20961 N |
136 | printk(KERN_INFO "md/raid0:%s: EQUAL\n", |
137 | mdname(mddev)); | |
1da177e4 LT |
138 | c = 1; |
139 | break; | |
140 | } | |
b5a20961 N |
141 | printk(KERN_INFO "md/raid0:%s: NOT EQUAL\n", |
142 | mdname(mddev)); | |
1da177e4 LT |
143 | } |
144 | if (!c) { | |
b5a20961 N |
145 | printk(KERN_INFO "md/raid0:%s: ==> UNIQUE\n", |
146 | mdname(mddev)); | |
1da177e4 | 147 | conf->nr_strip_zones++; |
b5a20961 N |
148 | printk(KERN_INFO "md/raid0:%s: %d zones\n", |
149 | mdname(mddev), conf->nr_strip_zones); | |
1da177e4 LT |
150 | } |
151 | } | |
b5a20961 N |
152 | printk(KERN_INFO "md/raid0:%s: FINAL %d zones\n", |
153 | mdname(mddev), conf->nr_strip_zones); | |
ed7b0038 | 154 | err = -ENOMEM; |
9ffae0cf | 155 | conf->strip_zone = kzalloc(sizeof(struct strip_zone)* |
1da177e4 LT |
156 | conf->nr_strip_zones, GFP_KERNEL); |
157 | if (!conf->strip_zone) | |
ed7b0038 | 158 | goto abort; |
9ffae0cf | 159 | conf->devlist = kzalloc(sizeof(mdk_rdev_t*)* |
1da177e4 LT |
160 | conf->nr_strip_zones*mddev->raid_disks, |
161 | GFP_KERNEL); | |
162 | if (!conf->devlist) | |
ed7b0038 | 163 | goto abort; |
1da177e4 | 164 | |
1da177e4 LT |
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; | |
b414579f | 171 | dev = conf->devlist; |
ed7b0038 | 172 | err = -EINVAL; |
159ec1fc | 173 | list_for_each_entry(rdev1, &mddev->disks, same_set) { |
1da177e4 LT |
174 | int j = rdev1->raid_disk; |
175 | ||
9af204cf TM |
176 | if (mddev->level == 10) |
177 | /* taking over a raid10-n2 array */ | |
178 | j /= 2; | |
179 | ||
1da177e4 | 180 | if (j < 0 || j >= mddev->raid_disks) { |
b5a20961 N |
181 | printk(KERN_ERR "md/raid0:%s: bad disk number %d - " |
182 | "aborting!\n", mdname(mddev), j); | |
1da177e4 LT |
183 | goto abort; |
184 | } | |
b414579f | 185 | if (dev[j]) { |
b5a20961 N |
186 | printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " |
187 | "aborting!\n", mdname(mddev), j); | |
1da177e4 LT |
188 | goto abort; |
189 | } | |
b414579f | 190 | dev[j] = rdev1; |
1da177e4 | 191 | |
8f6c2e4b MP |
192 | disk_stack_limits(mddev->gendisk, rdev1->bdev, |
193 | rdev1->data_offset << 9); | |
1da177e4 | 194 | /* as we don't honour merge_bvec_fn, we must never risk |
627a2d3c N |
195 | * violating it, so limit ->max_segments to 1, lying within |
196 | * a single page. | |
1da177e4 LT |
197 | */ |
198 | ||
627a2d3c N |
199 | if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) { |
200 | blk_queue_max_segments(mddev->queue, 1); | |
201 | blk_queue_segment_boundary(mddev->queue, | |
202 | PAGE_CACHE_SIZE - 1); | |
203 | } | |
dd8ac336 | 204 | if (!smallest || (rdev1->sectors < smallest->sectors)) |
1da177e4 LT |
205 | smallest = rdev1; |
206 | cnt++; | |
207 | } | |
208 | if (cnt != mddev->raid_disks) { | |
b5a20961 N |
209 | printk(KERN_ERR "md/raid0:%s: too few disks (%d of %d) - " |
210 | "aborting!\n", mdname(mddev), cnt, mddev->raid_disks); | |
1da177e4 LT |
211 | goto abort; |
212 | } | |
213 | zone->nb_dev = cnt; | |
49f357a2 | 214 | zone->zone_end = smallest->sectors * cnt; |
1da177e4 | 215 | |
49f357a2 | 216 | curr_zone_end = zone->zone_end; |
1da177e4 LT |
217 | |
218 | /* now do the other zones */ | |
219 | for (i = 1; i < conf->nr_strip_zones; i++) | |
220 | { | |
a9f326eb N |
221 | int j; |
222 | ||
1da177e4 | 223 | zone = conf->strip_zone + i; |
b414579f | 224 | dev = conf->devlist + i * mddev->raid_disks; |
1da177e4 | 225 | |
b5a20961 N |
226 | printk(KERN_INFO "md/raid0:%s: zone %d\n", |
227 | mdname(mddev), i); | |
d27a43ab | 228 | zone->dev_start = smallest->sectors; |
1da177e4 LT |
229 | smallest = NULL; |
230 | c = 0; | |
231 | ||
232 | for (j=0; j<cnt; j++) { | |
b414579f | 233 | rdev = conf->devlist[j]; |
b5a20961 N |
234 | printk(KERN_INFO "md/raid0:%s: checking %s ...", |
235 | mdname(mddev), | |
236 | bdevname(rdev->bdev, b)); | |
d27a43ab | 237 | if (rdev->sectors <= zone->dev_start) { |
b5a20961 | 238 | printk(KERN_CONT " nope.\n"); |
dd8ac336 AN |
239 | continue; |
240 | } | |
b5a20961 | 241 | printk(KERN_CONT " contained as device %d\n", c); |
b414579f | 242 | dev[c] = rdev; |
dd8ac336 AN |
243 | c++; |
244 | if (!smallest || rdev->sectors < smallest->sectors) { | |
245 | smallest = rdev; | |
b5a20961 N |
246 | printk(KERN_INFO "md/raid0:%s: (%llu) is smallest!.\n", |
247 | mdname(mddev), | |
248 | (unsigned long long)rdev->sectors); | |
dd8ac336 | 249 | } |
1da177e4 LT |
250 | } |
251 | ||
252 | zone->nb_dev = c; | |
49f357a2 | 253 | sectors = (smallest->sectors - zone->dev_start) * c; |
b5a20961 N |
254 | printk(KERN_INFO "md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", |
255 | mdname(mddev), | |
256 | zone->nb_dev, (unsigned long long)sectors); | |
1da177e4 | 257 | |
49f357a2 | 258 | curr_zone_end += sectors; |
d27a43ab | 259 | zone->zone_end = curr_zone_end; |
1da177e4 | 260 | |
b5a20961 N |
261 | printk(KERN_INFO "md/raid0:%s: current zone start: %llu\n", |
262 | mdname(mddev), | |
263 | (unsigned long long)smallest->sectors); | |
1da177e4 | 264 | } |
1da177e4 | 265 | mddev->queue->unplug_fn = raid0_unplug; |
26be34dc N |
266 | mddev->queue->backing_dev_info.congested_fn = raid0_congested; |
267 | mddev->queue->backing_dev_info.congested_data = mddev; | |
1da177e4 | 268 | |
92e59b6b | 269 | /* |
270 | * now since we have the hard sector sizes, we can make sure | |
271 | * chunk size is a multiple of that sector size | |
272 | */ | |
9d8f0363 | 273 | if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) { |
b5a20961 | 274 | printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", |
92e59b6b | 275 | mdname(mddev), |
9d8f0363 | 276 | mddev->chunk_sectors << 9); |
92e59b6b | 277 | goto abort; |
278 | } | |
8f6c2e4b MP |
279 | |
280 | blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); | |
281 | blk_queue_io_opt(mddev->queue, | |
282 | (mddev->chunk_sectors << 9) * mddev->raid_disks); | |
283 | ||
b5a20961 | 284 | printk(KERN_INFO "md/raid0:%s: done.\n", mdname(mddev)); |
9af204cf TM |
285 | *private_conf = conf; |
286 | ||
1da177e4 | 287 | return 0; |
5568a603 | 288 | abort: |
ed7b0038 AN |
289 | kfree(conf->strip_zone); |
290 | kfree(conf->devlist); | |
291 | kfree(conf); | |
9af204cf | 292 | *private_conf = NULL; |
ed7b0038 | 293 | return err; |
1da177e4 LT |
294 | } |
295 | ||
296 | /** | |
297 | * raid0_mergeable_bvec -- tell bio layer if a two requests can be merged | |
298 | * @q: request queue | |
cc371e66 | 299 | * @bvm: properties of new bio |
1da177e4 LT |
300 | * @biovec: the request that could be merged to it. |
301 | * | |
302 | * Return amount of bytes we can accept at this offset | |
303 | */ | |
cc371e66 AK |
304 | static int raid0_mergeable_bvec(struct request_queue *q, |
305 | struct bvec_merge_data *bvm, | |
306 | struct bio_vec *biovec) | |
1da177e4 LT |
307 | { |
308 | mddev_t *mddev = q->queuedata; | |
cc371e66 | 309 | sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); |
1da177e4 | 310 | int max; |
9d8f0363 | 311 | unsigned int chunk_sectors = mddev->chunk_sectors; |
cc371e66 | 312 | unsigned int bio_sectors = bvm->bi_size >> 9; |
1da177e4 | 313 | |
d6e412ea | 314 | if (is_power_of_2(chunk_sectors)) |
fbb704ef | 315 | max = (chunk_sectors - ((sector & (chunk_sectors-1)) |
316 | + bio_sectors)) << 9; | |
317 | else | |
318 | max = (chunk_sectors - (sector_div(sector, chunk_sectors) | |
319 | + bio_sectors)) << 9; | |
1da177e4 LT |
320 | if (max < 0) max = 0; /* bio_add cannot handle a negative return */ |
321 | if (max <= biovec->bv_len && bio_sectors == 0) | |
322 | return biovec->bv_len; | |
323 | else | |
324 | return max; | |
325 | } | |
326 | ||
80c3a6ce DW |
327 | static sector_t raid0_size(mddev_t *mddev, sector_t sectors, int raid_disks) |
328 | { | |
329 | sector_t array_sectors = 0; | |
330 | mdk_rdev_t *rdev; | |
331 | ||
332 | WARN_ONCE(sectors || raid_disks, | |
333 | "%s does not support generic reshape\n", __func__); | |
334 | ||
335 | list_for_each_entry(rdev, &mddev->disks, same_set) | |
336 | array_sectors += rdev->sectors; | |
337 | ||
338 | return array_sectors; | |
339 | } | |
340 | ||
8f79cfcd | 341 | static int raid0_run(mddev_t *mddev) |
1da177e4 | 342 | { |
9af204cf | 343 | raid0_conf_t *conf; |
5568a603 | 344 | int ret; |
1da177e4 | 345 | |
9d8f0363 | 346 | if (mddev->chunk_sectors == 0) { |
b5a20961 N |
347 | printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", |
348 | mdname(mddev)); | |
2604b703 N |
349 | return -EINVAL; |
350 | } | |
0894cc30 AN |
351 | if (md_check_no_bitmap(mddev)) |
352 | return -EINVAL; | |
086fa5ff | 353 | blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); |
e7e72bf6 | 354 | mddev->queue->queue_lock = &mddev->queue->__queue_lock; |
1da177e4 | 355 | |
9af204cf TM |
356 | /* if private is not null, we are here after takeover */ |
357 | if (mddev->private == NULL) { | |
358 | ret = create_strip_zones(mddev, &conf); | |
359 | if (ret < 0) | |
360 | return ret; | |
361 | mddev->private = conf; | |
362 | } | |
363 | conf = mddev->private; | |
364 | if (conf->scale_raid_disks) { | |
365 | int i; | |
366 | for (i=0; i < conf->strip_zone[0].nb_dev; i++) | |
367 | conf->devlist[i]->raid_disk /= conf->scale_raid_disks; | |
368 | /* FIXME update sysfs rd links */ | |
369 | } | |
1da177e4 LT |
370 | |
371 | /* calculate array device size */ | |
1f403624 | 372 | md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); |
1da177e4 | 373 | |
b5a20961 N |
374 | printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", |
375 | mdname(mddev), | |
376 | (unsigned long long)mddev->array_sectors); | |
1da177e4 LT |
377 | /* calculate the max read-ahead size. |
378 | * For read-ahead of large files to be effective, we need to | |
379 | * readahead at least twice a whole stripe. i.e. number of devices | |
380 | * multiplied by chunk size times 2. | |
381 | * If an individual device has an ra_pages greater than the | |
382 | * chunk size, then we will not drive that device as hard as it | |
383 | * wants. We consider this a configuration error: a larger | |
384 | * chunksize should be used in that case. | |
385 | */ | |
386 | { | |
9d8f0363 AN |
387 | int stripe = mddev->raid_disks * |
388 | (mddev->chunk_sectors << 9) / PAGE_SIZE; | |
1da177e4 LT |
389 | if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) |
390 | mddev->queue->backing_dev_info.ra_pages = 2* stripe; | |
391 | } | |
392 | ||
1da177e4 | 393 | blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); |
46994191 | 394 | dump_zones(mddev); |
ac5e7113 | 395 | md_integrity_register(mddev); |
1da177e4 | 396 | return 0; |
1da177e4 LT |
397 | } |
398 | ||
fb5ab4b5 | 399 | static int raid0_stop(mddev_t *mddev) |
1da177e4 | 400 | { |
070ec55d | 401 | raid0_conf_t *conf = mddev->private; |
1da177e4 LT |
402 | |
403 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
990a8baf | 404 | kfree(conf->strip_zone); |
fb5ab4b5 | 405 | kfree(conf->devlist); |
990a8baf | 406 | kfree(conf); |
1da177e4 | 407 | mddev->private = NULL; |
1da177e4 LT |
408 | return 0; |
409 | } | |
410 | ||
49f357a2 N |
411 | /* Find the zone which holds a particular offset |
412 | * Update *sectorp to be an offset in that zone | |
413 | */ | |
dc582663 | 414 | static struct strip_zone *find_zone(struct raid0_private_data *conf, |
49f357a2 | 415 | sector_t *sectorp) |
dc582663 AN |
416 | { |
417 | int i; | |
418 | struct strip_zone *z = conf->strip_zone; | |
49f357a2 | 419 | sector_t sector = *sectorp; |
dc582663 AN |
420 | |
421 | for (i = 0; i < conf->nr_strip_zones; i++) | |
49f357a2 N |
422 | if (sector < z[i].zone_end) { |
423 | if (i) | |
424 | *sectorp = sector - z[i-1].zone_end; | |
dc582663 | 425 | return z + i; |
49f357a2 | 426 | } |
dc582663 AN |
427 | BUG(); |
428 | } | |
429 | ||
fbb704ef | 430 | /* |
431 | * remaps the bio to the target device. we separate two flows. | |
432 | * power 2 flow and a general flow for the sake of perfromance | |
433 | */ | |
434 | static mdk_rdev_t *map_sector(mddev_t *mddev, struct strip_zone *zone, | |
435 | sector_t sector, sector_t *sector_offset) | |
1da177e4 | 436 | { |
fbb704ef | 437 | unsigned int sect_in_chunk; |
438 | sector_t chunk; | |
070ec55d | 439 | raid0_conf_t *conf = mddev->private; |
84707f38 | 440 | int raid_disks = conf->strip_zone[0].nb_dev; |
9d8f0363 | 441 | unsigned int chunk_sects = mddev->chunk_sectors; |
fbb704ef | 442 | |
d6e412ea | 443 | if (is_power_of_2(chunk_sects)) { |
fbb704ef | 444 | int chunksect_bits = ffz(~chunk_sects); |
445 | /* find the sector offset inside the chunk */ | |
446 | sect_in_chunk = sector & (chunk_sects - 1); | |
447 | sector >>= chunksect_bits; | |
448 | /* chunk in zone */ | |
449 | chunk = *sector_offset; | |
450 | /* quotient is the chunk in real device*/ | |
451 | sector_div(chunk, zone->nb_dev << chunksect_bits); | |
452 | } else{ | |
453 | sect_in_chunk = sector_div(sector, chunk_sects); | |
454 | chunk = *sector_offset; | |
455 | sector_div(chunk, chunk_sects * zone->nb_dev); | |
456 | } | |
457 | /* | |
458 | * position the bio over the real device | |
459 | * real sector = chunk in device + starting of zone | |
460 | * + the position in the chunk | |
461 | */ | |
462 | *sector_offset = (chunk * chunk_sects) + sect_in_chunk; | |
84707f38 | 463 | return conf->devlist[(zone - conf->strip_zone)*raid_disks |
fbb704ef | 464 | + sector_div(sector, zone->nb_dev)]; |
465 | } | |
466 | ||
467 | /* | |
468 | * Is io distribute over 1 or more chunks ? | |
469 | */ | |
470 | static inline int is_io_in_chunk_boundary(mddev_t *mddev, | |
471 | unsigned int chunk_sects, struct bio *bio) | |
472 | { | |
d6e412ea | 473 | if (likely(is_power_of_2(chunk_sects))) { |
fbb704ef | 474 | return chunk_sects >= ((bio->bi_sector & (chunk_sects-1)) |
475 | + (bio->bi_size >> 9)); | |
476 | } else{ | |
477 | sector_t sector = bio->bi_sector; | |
478 | return chunk_sects >= (sector_div(sector, chunk_sects) | |
479 | + (bio->bi_size >> 9)); | |
480 | } | |
481 | } | |
482 | ||
21a52c6d | 483 | static int raid0_make_request(mddev_t *mddev, struct bio *bio) |
fbb704ef | 484 | { |
fbb704ef | 485 | unsigned int chunk_sects; |
486 | sector_t sector_offset; | |
1da177e4 LT |
487 | struct strip_zone *zone; |
488 | mdk_rdev_t *tmp_dev; | |
1da177e4 | 489 | |
1f98a13f | 490 | if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) { |
a2826aa9 | 491 | md_barrier_request(mddev, bio); |
e5dcdd80 N |
492 | return 0; |
493 | } | |
494 | ||
9d8f0363 | 495 | chunk_sects = mddev->chunk_sectors; |
fbb704ef | 496 | if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) { |
497 | sector_t sector = bio->bi_sector; | |
1da177e4 LT |
498 | struct bio_pair *bp; |
499 | /* Sanity check -- queue functions should prevent this happening */ | |
500 | if (bio->bi_vcnt != 1 || | |
501 | bio->bi_idx != 0) | |
502 | goto bad_map; | |
503 | /* This is a one page bio that upper layers | |
504 | * refuse to split for us, so we need to split it. | |
505 | */ | |
d6e412ea | 506 | if (likely(is_power_of_2(chunk_sects))) |
fbb704ef | 507 | bp = bio_split(bio, chunk_sects - (sector & |
508 | (chunk_sects-1))); | |
509 | else | |
510 | bp = bio_split(bio, chunk_sects - | |
511 | sector_div(sector, chunk_sects)); | |
21a52c6d | 512 | if (raid0_make_request(mddev, &bp->bio1)) |
1da177e4 | 513 | generic_make_request(&bp->bio1); |
21a52c6d | 514 | if (raid0_make_request(mddev, &bp->bio2)) |
1da177e4 LT |
515 | generic_make_request(&bp->bio2); |
516 | ||
517 | bio_pair_release(bp); | |
518 | return 0; | |
519 | } | |
1da177e4 | 520 | |
fbb704ef | 521 | sector_offset = bio->bi_sector; |
522 | zone = find_zone(mddev->private, §or_offset); | |
523 | tmp_dev = map_sector(mddev, zone, bio->bi_sector, | |
524 | §or_offset); | |
1da177e4 | 525 | bio->bi_bdev = tmp_dev->bdev; |
fbb704ef | 526 | bio->bi_sector = sector_offset + zone->dev_start + |
527 | tmp_dev->data_offset; | |
1da177e4 LT |
528 | /* |
529 | * Let the main block layer submit the IO and resolve recursion: | |
530 | */ | |
531 | return 1; | |
532 | ||
533 | bad_map: | |
b5a20961 N |
534 | printk("md/raid0:%s: make_request bug: can't convert block across chunks" |
535 | " or bigger than %dk %llu %d\n", | |
536 | mdname(mddev), chunk_sects / 2, | |
537 | (unsigned long long)bio->bi_sector, bio->bi_size >> 10); | |
1da177e4 | 538 | |
6712ecf8 | 539 | bio_io_error(bio); |
1da177e4 LT |
540 | return 0; |
541 | } | |
8299d7f7 | 542 | |
1b961429 | 543 | static void raid0_status(struct seq_file *seq, mddev_t *mddev) |
1da177e4 LT |
544 | { |
545 | #undef MD_DEBUG | |
546 | #ifdef MD_DEBUG | |
547 | int j, k, h; | |
548 | char b[BDEVNAME_SIZE]; | |
070ec55d | 549 | raid0_conf_t *conf = mddev->private; |
84707f38 | 550 | int raid_disks = conf->strip_zone[0].nb_dev; |
8299d7f7 | 551 | |
1b961429 | 552 | sector_t zone_size; |
553 | sector_t zone_start = 0; | |
1da177e4 | 554 | h = 0; |
1b961429 | 555 | |
1da177e4 LT |
556 | for (j = 0; j < conf->nr_strip_zones; j++) { |
557 | seq_printf(seq, " z%d", j); | |
1da177e4 LT |
558 | seq_printf(seq, "=["); |
559 | for (k = 0; k < conf->strip_zone[j].nb_dev; k++) | |
8299d7f7 | 560 | seq_printf(seq, "%s/", bdevname( |
84707f38 | 561 | conf->devlist[j*raid_disks + k] |
1b961429 | 562 | ->bdev, b)); |
563 | ||
564 | zone_size = conf->strip_zone[j].zone_end - zone_start; | |
565 | seq_printf(seq, "] ze=%lld ds=%lld s=%lld\n", | |
566 | (unsigned long long)zone_start>>1, | |
567 | (unsigned long long)conf->strip_zone[j].dev_start>>1, | |
568 | (unsigned long long)zone_size>>1); | |
569 | zone_start = conf->strip_zone[j].zone_end; | |
1da177e4 LT |
570 | } |
571 | #endif | |
9d8f0363 | 572 | seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); |
1da177e4 LT |
573 | return; |
574 | } | |
575 | ||
9af204cf TM |
576 | static void *raid0_takeover_raid5(mddev_t *mddev) |
577 | { | |
578 | mdk_rdev_t *rdev; | |
579 | raid0_conf_t *priv_conf; | |
580 | ||
581 | if (mddev->degraded != 1) { | |
b5a20961 N |
582 | printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", |
583 | mdname(mddev), | |
9af204cf TM |
584 | mddev->degraded); |
585 | return ERR_PTR(-EINVAL); | |
586 | } | |
587 | ||
588 | list_for_each_entry(rdev, &mddev->disks, same_set) { | |
589 | /* check slot number for a disk */ | |
590 | if (rdev->raid_disk == mddev->raid_disks-1) { | |
b5a20961 N |
591 | printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n", |
592 | mdname(mddev)); | |
9af204cf TM |
593 | return ERR_PTR(-EINVAL); |
594 | } | |
595 | } | |
596 | ||
597 | /* Set new parameters */ | |
598 | mddev->new_level = 0; | |
599 | mddev->new_chunk_sectors = mddev->chunk_sectors; | |
600 | mddev->raid_disks--; | |
601 | mddev->delta_disks = -1; | |
602 | /* make sure it will be not marked as dirty */ | |
603 | mddev->recovery_cp = MaxSector; | |
604 | ||
605 | create_strip_zones(mddev, &priv_conf); | |
606 | return priv_conf; | |
607 | } | |
608 | ||
609 | static void *raid0_takeover_raid10(mddev_t *mddev) | |
610 | { | |
611 | raid0_conf_t *priv_conf; | |
612 | ||
613 | /* Check layout: | |
614 | * - far_copies must be 1 | |
615 | * - near_copies must be 2 | |
616 | * - disks number must be even | |
617 | * - all mirrors must be already degraded | |
618 | */ | |
619 | if (mddev->layout != ((1 << 8) + 2)) { | |
b5a20961 N |
620 | printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takover layout: 0x%x\n", |
621 | mdname(mddev), | |
9af204cf TM |
622 | mddev->layout); |
623 | return ERR_PTR(-EINVAL); | |
624 | } | |
625 | if (mddev->raid_disks & 1) { | |
b5a20961 N |
626 | printk(KERN_ERR "md/raid0:%s: Raid0 cannot takover Raid10 with odd disk number.\n", |
627 | mdname(mddev)); | |
9af204cf TM |
628 | return ERR_PTR(-EINVAL); |
629 | } | |
630 | if (mddev->degraded != (mddev->raid_disks>>1)) { | |
b5a20961 N |
631 | printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n", |
632 | mdname(mddev)); | |
9af204cf TM |
633 | return ERR_PTR(-EINVAL); |
634 | } | |
635 | ||
636 | /* Set new parameters */ | |
637 | mddev->new_level = 0; | |
638 | mddev->new_chunk_sectors = mddev->chunk_sectors; | |
639 | mddev->delta_disks = - mddev->raid_disks / 2; | |
640 | mddev->raid_disks += mddev->delta_disks; | |
641 | mddev->degraded = 0; | |
642 | /* make sure it will be not marked as dirty */ | |
643 | mddev->recovery_cp = MaxSector; | |
644 | ||
645 | create_strip_zones(mddev, &priv_conf); | |
646 | priv_conf->scale_raid_disks = 2; | |
647 | return priv_conf; | |
648 | } | |
649 | ||
650 | static void *raid0_takeover(mddev_t *mddev) | |
651 | { | |
652 | /* raid0 can take over: | |
653 | * raid5 - providing it is Raid4 layout and one disk is faulty | |
654 | * raid10 - assuming we have all necessary active disks | |
655 | */ | |
656 | if (mddev->level == 5) { | |
657 | if (mddev->layout == ALGORITHM_PARITY_N) | |
658 | return raid0_takeover_raid5(mddev); | |
659 | ||
b5a20961 N |
660 | printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", |
661 | mdname(mddev), ALGORITHM_PARITY_N); | |
9af204cf TM |
662 | } |
663 | ||
664 | if (mddev->level == 10) | |
665 | return raid0_takeover_raid10(mddev); | |
666 | ||
667 | return ERR_PTR(-EINVAL); | |
668 | } | |
669 | ||
670 | static void raid0_quiesce(mddev_t *mddev, int state) | |
671 | { | |
672 | } | |
673 | ||
2604b703 | 674 | static struct mdk_personality raid0_personality= |
1da177e4 LT |
675 | { |
676 | .name = "raid0", | |
2604b703 | 677 | .level = 0, |
1da177e4 LT |
678 | .owner = THIS_MODULE, |
679 | .make_request = raid0_make_request, | |
680 | .run = raid0_run, | |
681 | .stop = raid0_stop, | |
682 | .status = raid0_status, | |
80c3a6ce | 683 | .size = raid0_size, |
9af204cf TM |
684 | .takeover = raid0_takeover, |
685 | .quiesce = raid0_quiesce, | |
1da177e4 LT |
686 | }; |
687 | ||
688 | static int __init raid0_init (void) | |
689 | { | |
2604b703 | 690 | return register_md_personality (&raid0_personality); |
1da177e4 LT |
691 | } |
692 | ||
693 | static void raid0_exit (void) | |
694 | { | |
2604b703 | 695 | unregister_md_personality (&raid0_personality); |
1da177e4 LT |
696 | } |
697 | ||
698 | module_init(raid0_init); | |
699 | module_exit(raid0_exit); | |
700 | MODULE_LICENSE("GPL"); | |
0efb9e61 | 701 | MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); |
1da177e4 | 702 | MODULE_ALIAS("md-personality-2"); /* RAID0 */ |
d9d166c2 | 703 | MODULE_ALIAS("md-raid0"); |
2604b703 | 704 | MODULE_ALIAS("md-level-0"); |