Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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/module.h> |
| 22 | #include <linux/raid/raid0.h> |
| 23 | |
| 24 | #define MAJOR_NR MD_MAJOR |
| 25 | #define MD_DRIVER |
| 26 | #define MD_PERSONALITY |
| 27 | |
| 28 | static void raid0_unplug(request_queue_t *q) |
| 29 | { |
| 30 | mddev_t *mddev = q->queuedata; |
| 31 | raid0_conf_t *conf = mddev_to_conf(mddev); |
| 32 | mdk_rdev_t **devlist = conf->strip_zone[0].dev; |
| 33 | int i; |
| 34 | |
| 35 | for (i=0; i<mddev->raid_disks; i++) { |
| 36 | request_queue_t *r_queue = bdev_get_queue(devlist[i]->bdev); |
| 37 | |
| 38 | if (r_queue->unplug_fn) |
| 39 | r_queue->unplug_fn(r_queue); |
| 40 | } |
| 41 | } |
| 42 | |
| 43 | static int raid0_issue_flush(request_queue_t *q, struct gendisk *disk, |
| 44 | sector_t *error_sector) |
| 45 | { |
| 46 | mddev_t *mddev = q->queuedata; |
| 47 | raid0_conf_t *conf = mddev_to_conf(mddev); |
| 48 | mdk_rdev_t **devlist = conf->strip_zone[0].dev; |
| 49 | int i, ret = 0; |
| 50 | |
| 51 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { |
| 52 | struct block_device *bdev = devlist[i]->bdev; |
| 53 | request_queue_t *r_queue = bdev_get_queue(bdev); |
| 54 | |
| 55 | if (!r_queue->issue_flush_fn) |
| 56 | ret = -EOPNOTSUPP; |
| 57 | else |
| 58 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, error_sector); |
| 59 | } |
| 60 | return ret; |
| 61 | } |
| 62 | |
NeilBrown | 26be34d | 2006-10-03 01:15:53 -0700 | [diff] [blame] | 63 | static int raid0_congested(void *data, int bits) |
| 64 | { |
| 65 | mddev_t *mddev = data; |
| 66 | raid0_conf_t *conf = mddev_to_conf(mddev); |
| 67 | mdk_rdev_t **devlist = conf->strip_zone[0].dev; |
| 68 | int i, ret = 0; |
| 69 | |
| 70 | for (i = 0; i < mddev->raid_disks && !ret ; i++) { |
| 71 | request_queue_t *q = bdev_get_queue(devlist[i]->bdev); |
| 72 | |
| 73 | ret |= bdi_congested(&q->backing_dev_info, bits); |
| 74 | } |
| 75 | return ret; |
| 76 | } |
| 77 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | |
| 79 | static int create_strip_zones (mddev_t *mddev) |
| 80 | { |
| 81 | int i, c, j; |
| 82 | sector_t current_offset, curr_zone_offset; |
| 83 | sector_t min_spacing; |
| 84 | raid0_conf_t *conf = mddev_to_conf(mddev); |
| 85 | mdk_rdev_t *smallest, *rdev1, *rdev2, *rdev; |
| 86 | struct list_head *tmp1, *tmp2; |
| 87 | struct strip_zone *zone; |
| 88 | int cnt; |
| 89 | char b[BDEVNAME_SIZE]; |
| 90 | |
| 91 | /* |
| 92 | * The number of 'same size groups' |
| 93 | */ |
| 94 | conf->nr_strip_zones = 0; |
| 95 | |
| 96 | ITERATE_RDEV(mddev,rdev1,tmp1) { |
| 97 | printk("raid0: looking at %s\n", |
| 98 | bdevname(rdev1->bdev,b)); |
| 99 | c = 0; |
| 100 | ITERATE_RDEV(mddev,rdev2,tmp2) { |
| 101 | printk("raid0: comparing %s(%llu)", |
| 102 | bdevname(rdev1->bdev,b), |
| 103 | (unsigned long long)rdev1->size); |
| 104 | printk(" with %s(%llu)\n", |
| 105 | bdevname(rdev2->bdev,b), |
| 106 | (unsigned long long)rdev2->size); |
| 107 | if (rdev2 == rdev1) { |
| 108 | printk("raid0: END\n"); |
| 109 | break; |
| 110 | } |
| 111 | if (rdev2->size == rdev1->size) |
| 112 | { |
| 113 | /* |
| 114 | * Not unique, don't count it as a new |
| 115 | * group |
| 116 | */ |
| 117 | printk("raid0: EQUAL\n"); |
| 118 | c = 1; |
| 119 | break; |
| 120 | } |
| 121 | printk("raid0: NOT EQUAL\n"); |
| 122 | } |
| 123 | if (!c) { |
| 124 | printk("raid0: ==> UNIQUE\n"); |
| 125 | conf->nr_strip_zones++; |
| 126 | printk("raid0: %d zones\n", conf->nr_strip_zones); |
| 127 | } |
| 128 | } |
| 129 | printk("raid0: FINAL %d zones\n", conf->nr_strip_zones); |
| 130 | |
NeilBrown | 9ffae0c | 2006-01-06 00:20:32 -0800 | [diff] [blame] | 131 | conf->strip_zone = kzalloc(sizeof(struct strip_zone)* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | conf->nr_strip_zones, GFP_KERNEL); |
| 133 | if (!conf->strip_zone) |
| 134 | return 1; |
NeilBrown | 9ffae0c | 2006-01-06 00:20:32 -0800 | [diff] [blame] | 135 | conf->devlist = kzalloc(sizeof(mdk_rdev_t*)* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | conf->nr_strip_zones*mddev->raid_disks, |
| 137 | GFP_KERNEL); |
| 138 | if (!conf->devlist) |
| 139 | return 1; |
| 140 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | /* The first zone must contain all devices, so here we check that |
| 142 | * there is a proper alignment of slots to devices and find them all |
| 143 | */ |
| 144 | zone = &conf->strip_zone[0]; |
| 145 | cnt = 0; |
| 146 | smallest = NULL; |
| 147 | zone->dev = conf->devlist; |
| 148 | ITERATE_RDEV(mddev, rdev1, tmp1) { |
| 149 | int j = rdev1->raid_disk; |
| 150 | |
| 151 | if (j < 0 || j >= mddev->raid_disks) { |
| 152 | printk("raid0: bad disk number %d - aborting!\n", j); |
| 153 | goto abort; |
| 154 | } |
| 155 | if (zone->dev[j]) { |
| 156 | printk("raid0: multiple devices for %d - aborting!\n", |
| 157 | j); |
| 158 | goto abort; |
| 159 | } |
| 160 | zone->dev[j] = rdev1; |
| 161 | |
| 162 | blk_queue_stack_limits(mddev->queue, |
| 163 | rdev1->bdev->bd_disk->queue); |
| 164 | /* as we don't honour merge_bvec_fn, we must never risk |
| 165 | * violating it, so limit ->max_sector to one PAGE, as |
| 166 | * a one page request is never in violation. |
| 167 | */ |
| 168 | |
| 169 | if (rdev1->bdev->bd_disk->queue->merge_bvec_fn && |
| 170 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) |
| 171 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); |
| 172 | |
| 173 | if (!smallest || (rdev1->size <smallest->size)) |
| 174 | smallest = rdev1; |
| 175 | cnt++; |
| 176 | } |
| 177 | if (cnt != mddev->raid_disks) { |
| 178 | printk("raid0: too few disks (%d of %d) - aborting!\n", |
| 179 | cnt, mddev->raid_disks); |
| 180 | goto abort; |
| 181 | } |
| 182 | zone->nb_dev = cnt; |
| 183 | zone->size = smallest->size * cnt; |
| 184 | zone->zone_offset = 0; |
| 185 | |
| 186 | current_offset = smallest->size; |
| 187 | curr_zone_offset = zone->size; |
| 188 | |
| 189 | /* now do the other zones */ |
| 190 | for (i = 1; i < conf->nr_strip_zones; i++) |
| 191 | { |
| 192 | zone = conf->strip_zone + i; |
| 193 | zone->dev = conf->strip_zone[i-1].dev + mddev->raid_disks; |
| 194 | |
| 195 | printk("raid0: zone %d\n", i); |
| 196 | zone->dev_offset = current_offset; |
| 197 | smallest = NULL; |
| 198 | c = 0; |
| 199 | |
| 200 | for (j=0; j<cnt; j++) { |
| 201 | char b[BDEVNAME_SIZE]; |
| 202 | rdev = conf->strip_zone[0].dev[j]; |
| 203 | printk("raid0: checking %s ...", bdevname(rdev->bdev,b)); |
| 204 | if (rdev->size > current_offset) |
| 205 | { |
| 206 | printk(" contained as device %d\n", c); |
| 207 | zone->dev[c] = rdev; |
| 208 | c++; |
| 209 | if (!smallest || (rdev->size <smallest->size)) { |
| 210 | smallest = rdev; |
| 211 | printk(" (%llu) is smallest!.\n", |
| 212 | (unsigned long long)rdev->size); |
| 213 | } |
| 214 | } else |
| 215 | printk(" nope.\n"); |
| 216 | } |
| 217 | |
| 218 | zone->nb_dev = c; |
| 219 | zone->size = (smallest->size - current_offset) * c; |
| 220 | printk("raid0: zone->nb_dev: %d, size: %llu\n", |
| 221 | zone->nb_dev, (unsigned long long)zone->size); |
| 222 | |
| 223 | zone->zone_offset = curr_zone_offset; |
| 224 | curr_zone_offset += zone->size; |
| 225 | |
| 226 | current_offset = smallest->size; |
| 227 | printk("raid0: current zone offset: %llu\n", |
| 228 | (unsigned long long)current_offset); |
| 229 | } |
| 230 | |
| 231 | /* Now find appropriate hash spacing. |
| 232 | * We want a number which causes most hash entries to cover |
| 233 | * at most two strips, but the hash table must be at most |
| 234 | * 1 PAGE. We choose the smallest strip, or contiguous collection |
| 235 | * of strips, that has big enough size. We never consider the last |
| 236 | * strip though as it's size has no bearing on the efficacy of the hash |
| 237 | * table. |
| 238 | */ |
| 239 | conf->hash_spacing = curr_zone_offset; |
| 240 | min_spacing = curr_zone_offset; |
| 241 | sector_div(min_spacing, PAGE_SIZE/sizeof(struct strip_zone*)); |
| 242 | for (i=0; i < conf->nr_strip_zones-1; i++) { |
| 243 | sector_t sz = 0; |
| 244 | for (j=i; j<conf->nr_strip_zones-1 && |
| 245 | sz < min_spacing ; j++) |
| 246 | sz += conf->strip_zone[j].size; |
| 247 | if (sz >= min_spacing && sz < conf->hash_spacing) |
| 248 | conf->hash_spacing = sz; |
| 249 | } |
| 250 | |
| 251 | mddev->queue->unplug_fn = raid0_unplug; |
| 252 | |
| 253 | mddev->queue->issue_flush_fn = raid0_issue_flush; |
NeilBrown | 26be34d | 2006-10-03 01:15:53 -0700 | [diff] [blame] | 254 | mddev->queue->backing_dev_info.congested_fn = raid0_congested; |
| 255 | mddev->queue->backing_dev_info.congested_data = mddev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 256 | |
| 257 | printk("raid0: done.\n"); |
| 258 | return 0; |
| 259 | abort: |
| 260 | return 1; |
| 261 | } |
| 262 | |
| 263 | /** |
| 264 | * raid0_mergeable_bvec -- tell bio layer if a two requests can be merged |
| 265 | * @q: request queue |
| 266 | * @bio: the buffer head that's been built up so far |
| 267 | * @biovec: the request that could be merged to it. |
| 268 | * |
| 269 | * Return amount of bytes we can accept at this offset |
| 270 | */ |
| 271 | static int raid0_mergeable_bvec(request_queue_t *q, struct bio *bio, struct bio_vec *biovec) |
| 272 | { |
| 273 | mddev_t *mddev = q->queuedata; |
| 274 | sector_t sector = bio->bi_sector + get_start_sect(bio->bi_bdev); |
| 275 | int max; |
| 276 | unsigned int chunk_sectors = mddev->chunk_size >> 9; |
| 277 | unsigned int bio_sectors = bio->bi_size >> 9; |
| 278 | |
| 279 | max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; |
| 280 | if (max < 0) max = 0; /* bio_add cannot handle a negative return */ |
| 281 | if (max <= biovec->bv_len && bio_sectors == 0) |
| 282 | return biovec->bv_len; |
| 283 | else |
| 284 | return max; |
| 285 | } |
| 286 | |
| 287 | static int raid0_run (mddev_t *mddev) |
| 288 | { |
| 289 | unsigned cur=0, i=0, nb_zone; |
| 290 | s64 size; |
| 291 | raid0_conf_t *conf; |
| 292 | mdk_rdev_t *rdev; |
| 293 | struct list_head *tmp; |
| 294 | |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 295 | if (mddev->chunk_size == 0) { |
| 296 | printk(KERN_ERR "md/raid0: non-zero chunk size required.\n"); |
| 297 | return -EINVAL; |
| 298 | } |
| 299 | printk(KERN_INFO "%s: setting max_sectors to %d, segment boundary to %d\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | mdname(mddev), |
| 301 | mddev->chunk_size >> 9, |
| 302 | (mddev->chunk_size>>1)-1); |
| 303 | blk_queue_max_sectors(mddev->queue, mddev->chunk_size >> 9); |
| 304 | blk_queue_segment_boundary(mddev->queue, (mddev->chunk_size>>1) - 1); |
| 305 | |
| 306 | conf = kmalloc(sizeof (raid0_conf_t), GFP_KERNEL); |
| 307 | if (!conf) |
| 308 | goto out; |
| 309 | mddev->private = (void *)conf; |
| 310 | |
| 311 | conf->strip_zone = NULL; |
| 312 | conf->devlist = NULL; |
| 313 | if (create_strip_zones (mddev)) |
| 314 | goto out_free_conf; |
| 315 | |
| 316 | /* calculate array device size */ |
| 317 | mddev->array_size = 0; |
| 318 | ITERATE_RDEV(mddev,rdev,tmp) |
| 319 | mddev->array_size += rdev->size; |
| 320 | |
| 321 | printk("raid0 : md_size is %llu blocks.\n", |
| 322 | (unsigned long long)mddev->array_size); |
| 323 | printk("raid0 : conf->hash_spacing is %llu blocks.\n", |
| 324 | (unsigned long long)conf->hash_spacing); |
| 325 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | sector_t s = mddev->array_size; |
| 327 | sector_t space = conf->hash_spacing; |
| 328 | int round; |
| 329 | conf->preshift = 0; |
Neil Brown | 1eb2912 | 2005-07-15 03:56:27 -0700 | [diff] [blame] | 330 | if (sizeof(sector_t) > sizeof(u32)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | /*shift down space and s so that sector_div will work */ |
Neil Brown | 1eb2912 | 2005-07-15 03:56:27 -0700 | [diff] [blame] | 332 | while (space > (sector_t) (~(u32)0)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 333 | s >>= 1; |
| 334 | space >>= 1; |
| 335 | s += 1; /* force round-up */ |
| 336 | conf->preshift++; |
| 337 | } |
| 338 | } |
Neil Brown | 1eb2912 | 2005-07-15 03:56:27 -0700 | [diff] [blame] | 339 | round = sector_div(s, (u32)space) ? 1 : 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | nb_zone = s + round; |
| 341 | } |
| 342 | printk("raid0 : nb_zone is %d.\n", nb_zone); |
| 343 | |
| 344 | printk("raid0 : Allocating %Zd bytes for hash.\n", |
| 345 | nb_zone*sizeof(struct strip_zone*)); |
| 346 | conf->hash_table = kmalloc (sizeof (struct strip_zone *)*nb_zone, GFP_KERNEL); |
| 347 | if (!conf->hash_table) |
| 348 | goto out_free_conf; |
| 349 | size = conf->strip_zone[cur].size; |
| 350 | |
NeilBrown | 5c4c333 | 2006-05-22 22:35:26 -0700 | [diff] [blame] | 351 | conf->hash_table[0] = conf->strip_zone + cur; |
| 352 | for (i=1; i< nb_zone; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 353 | while (size <= conf->hash_spacing) { |
| 354 | cur++; |
| 355 | size += conf->strip_zone[cur].size; |
| 356 | } |
| 357 | size -= conf->hash_spacing; |
NeilBrown | 5c4c333 | 2006-05-22 22:35:26 -0700 | [diff] [blame] | 358 | conf->hash_table[i] = conf->strip_zone + cur; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 359 | } |
| 360 | if (conf->preshift) { |
| 361 | conf->hash_spacing >>= conf->preshift; |
| 362 | /* round hash_spacing up so when we divide by it, we |
| 363 | * err on the side of too-low, which is safest |
| 364 | */ |
| 365 | conf->hash_spacing++; |
| 366 | } |
| 367 | |
| 368 | /* calculate the max read-ahead size. |
| 369 | * For read-ahead of large files to be effective, we need to |
| 370 | * readahead at least twice a whole stripe. i.e. number of devices |
| 371 | * multiplied by chunk size times 2. |
| 372 | * If an individual device has an ra_pages greater than the |
| 373 | * chunk size, then we will not drive that device as hard as it |
| 374 | * wants. We consider this a configuration error: a larger |
| 375 | * chunksize should be used in that case. |
| 376 | */ |
| 377 | { |
NeilBrown | 2d1f3b5 | 2006-01-06 00:20:31 -0800 | [diff] [blame] | 378 | int stripe = mddev->raid_disks * mddev->chunk_size / PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) |
| 380 | mddev->queue->backing_dev_info.ra_pages = 2* stripe; |
| 381 | } |
| 382 | |
| 383 | |
| 384 | blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); |
| 385 | return 0; |
| 386 | |
| 387 | out_free_conf: |
Jesper Juhl | 990a8ba | 2005-06-21 17:17:30 -0700 | [diff] [blame] | 388 | kfree(conf->strip_zone); |
| 389 | kfree(conf->devlist); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | kfree(conf); |
| 391 | mddev->private = NULL; |
| 392 | out: |
NeilBrown | 29fc7e3 | 2006-02-03 03:03:41 -0800 | [diff] [blame] | 393 | return -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 394 | } |
| 395 | |
| 396 | static int raid0_stop (mddev_t *mddev) |
| 397 | { |
| 398 | raid0_conf_t *conf = mddev_to_conf(mddev); |
| 399 | |
| 400 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ |
Jesper Juhl | 990a8ba | 2005-06-21 17:17:30 -0700 | [diff] [blame] | 401 | kfree(conf->hash_table); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | conf->hash_table = NULL; |
Jesper Juhl | 990a8ba | 2005-06-21 17:17:30 -0700 | [diff] [blame] | 403 | kfree(conf->strip_zone); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | conf->strip_zone = NULL; |
Jesper Juhl | 990a8ba | 2005-06-21 17:17:30 -0700 | [diff] [blame] | 405 | kfree(conf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | mddev->private = NULL; |
| 407 | |
| 408 | return 0; |
| 409 | } |
| 410 | |
| 411 | static int raid0_make_request (request_queue_t *q, struct bio *bio) |
| 412 | { |
| 413 | mddev_t *mddev = q->queuedata; |
| 414 | unsigned int sect_in_chunk, chunksize_bits, chunk_size, chunk_sects; |
| 415 | raid0_conf_t *conf = mddev_to_conf(mddev); |
| 416 | struct strip_zone *zone; |
| 417 | mdk_rdev_t *tmp_dev; |
NeilBrown | 787f17f | 2007-05-23 13:58:09 -0700 | [diff] [blame] | 418 | sector_t chunk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | sector_t block, rsect; |
Jens Axboe | a362357 | 2005-11-01 09:26:16 +0100 | [diff] [blame] | 420 | const int rw = bio_data_dir(bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 421 | |
NeilBrown | e5dcdd8 | 2005-09-09 16:23:41 -0700 | [diff] [blame] | 422 | if (unlikely(bio_barrier(bio))) { |
| 423 | bio_endio(bio, bio->bi_size, -EOPNOTSUPP); |
| 424 | return 0; |
| 425 | } |
| 426 | |
Jens Axboe | a362357 | 2005-11-01 09:26:16 +0100 | [diff] [blame] | 427 | disk_stat_inc(mddev->gendisk, ios[rw]); |
| 428 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | |
| 430 | chunk_size = mddev->chunk_size >> 10; |
| 431 | chunk_sects = mddev->chunk_size >> 9; |
| 432 | chunksize_bits = ffz(~chunk_size); |
| 433 | block = bio->bi_sector >> 1; |
| 434 | |
| 435 | |
| 436 | if (unlikely(chunk_sects < (bio->bi_sector & (chunk_sects - 1)) + (bio->bi_size >> 9))) { |
| 437 | struct bio_pair *bp; |
| 438 | /* Sanity check -- queue functions should prevent this happening */ |
| 439 | if (bio->bi_vcnt != 1 || |
| 440 | bio->bi_idx != 0) |
| 441 | goto bad_map; |
| 442 | /* This is a one page bio that upper layers |
| 443 | * refuse to split for us, so we need to split it. |
| 444 | */ |
| 445 | bp = bio_split(bio, bio_split_pool, chunk_sects - (bio->bi_sector & (chunk_sects - 1)) ); |
| 446 | if (raid0_make_request(q, &bp->bio1)) |
| 447 | generic_make_request(&bp->bio1); |
| 448 | if (raid0_make_request(q, &bp->bio2)) |
| 449 | generic_make_request(&bp->bio2); |
| 450 | |
| 451 | bio_pair_release(bp); |
| 452 | return 0; |
| 453 | } |
| 454 | |
| 455 | |
| 456 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 457 | sector_t x = block >> conf->preshift; |
Neil Brown | 1eb2912 | 2005-07-15 03:56:27 -0700 | [diff] [blame] | 458 | sector_div(x, (u32)conf->hash_spacing); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | zone = conf->hash_table[x]; |
| 460 | } |
| 461 | |
| 462 | while (block >= (zone->zone_offset + zone->size)) |
| 463 | zone++; |
| 464 | |
| 465 | sect_in_chunk = bio->bi_sector & ((chunk_size<<1) -1); |
| 466 | |
| 467 | |
| 468 | { |
| 469 | sector_t x = (block - zone->zone_offset) >> chunksize_bits; |
| 470 | |
| 471 | sector_div(x, zone->nb_dev); |
| 472 | chunk = x; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | |
| 474 | x = block >> chunksize_bits; |
| 475 | tmp_dev = zone->dev[sector_div(x, zone->nb_dev)]; |
| 476 | } |
| 477 | rsect = (((chunk << chunksize_bits) + zone->dev_offset)<<1) |
| 478 | + sect_in_chunk; |
| 479 | |
| 480 | bio->bi_bdev = tmp_dev->bdev; |
| 481 | bio->bi_sector = rsect + tmp_dev->data_offset; |
| 482 | |
| 483 | /* |
| 484 | * Let the main block layer submit the IO and resolve recursion: |
| 485 | */ |
| 486 | return 1; |
| 487 | |
| 488 | bad_map: |
| 489 | printk("raid0_make_request bug: can't convert block across chunks" |
| 490 | " or bigger than %dk %llu %d\n", chunk_size, |
| 491 | (unsigned long long)bio->bi_sector, bio->bi_size >> 10); |
| 492 | |
| 493 | bio_io_error(bio, bio->bi_size); |
| 494 | return 0; |
| 495 | } |
| 496 | |
| 497 | static void raid0_status (struct seq_file *seq, mddev_t *mddev) |
| 498 | { |
| 499 | #undef MD_DEBUG |
| 500 | #ifdef MD_DEBUG |
| 501 | int j, k, h; |
| 502 | char b[BDEVNAME_SIZE]; |
| 503 | raid0_conf_t *conf = mddev_to_conf(mddev); |
| 504 | |
| 505 | h = 0; |
| 506 | for (j = 0; j < conf->nr_strip_zones; j++) { |
| 507 | seq_printf(seq, " z%d", j); |
| 508 | if (conf->hash_table[h] == conf->strip_zone+j) |
| 509 | seq_printf("(h%d)", h++); |
| 510 | seq_printf(seq, "=["); |
| 511 | for (k = 0; k < conf->strip_zone[j].nb_dev; k++) |
| 512 | seq_printf (seq, "%s/", bdevname( |
| 513 | conf->strip_zone[j].dev[k]->bdev,b)); |
| 514 | |
| 515 | seq_printf (seq, "] zo=%d do=%d s=%d\n", |
| 516 | conf->strip_zone[j].zone_offset, |
| 517 | conf->strip_zone[j].dev_offset, |
| 518 | conf->strip_zone[j].size); |
| 519 | } |
| 520 | #endif |
| 521 | seq_printf(seq, " %dk chunks", mddev->chunk_size/1024); |
| 522 | return; |
| 523 | } |
| 524 | |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 525 | static struct mdk_personality raid0_personality= |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | { |
| 527 | .name = "raid0", |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 528 | .level = 0, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | .owner = THIS_MODULE, |
| 530 | .make_request = raid0_make_request, |
| 531 | .run = raid0_run, |
| 532 | .stop = raid0_stop, |
| 533 | .status = raid0_status, |
| 534 | }; |
| 535 | |
| 536 | static int __init raid0_init (void) |
| 537 | { |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 538 | return register_md_personality (&raid0_personality); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | } |
| 540 | |
| 541 | static void raid0_exit (void) |
| 542 | { |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 543 | unregister_md_personality (&raid0_personality); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 544 | } |
| 545 | |
| 546 | module_init(raid0_init); |
| 547 | module_exit(raid0_exit); |
| 548 | MODULE_LICENSE("GPL"); |
| 549 | MODULE_ALIAS("md-personality-2"); /* RAID0 */ |
NeilBrown | d9d166c | 2006-01-06 00:20:51 -0800 | [diff] [blame] | 550 | MODULE_ALIAS("md-raid0"); |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame] | 551 | MODULE_ALIAS("md-level-0"); |