| 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 | printk(KERN_INFO "\n"); |
| 74 | } |
| 75 | |
| 76 | static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) |
| 77 | { |
| 78 | int i, c, err; |
| 79 | sector_t curr_zone_end, sectors; |
| 80 | struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; |
| 81 | struct strip_zone *zone; |
| 82 | int cnt; |
| 83 | char b[BDEVNAME_SIZE]; |
| 84 | char b2[BDEVNAME_SIZE]; |
| 85 | struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); |
| 86 | bool discard_supported = false; |
| 87 | |
| 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 | rdev_for_each(rdev2, mddev) { |
| 102 | pr_debug("md/raid0:%s: comparing %s(%llu)" |
| 103 | " with %s(%llu)\n", |
| 104 | mdname(mddev), |
| 105 | bdevname(rdev1->bdev,b), |
| 106 | (unsigned long long)rdev1->sectors, |
| 107 | bdevname(rdev2->bdev,b2), |
| 108 | (unsigned long long)rdev2->sectors); |
| 109 | if (rdev2 == rdev1) { |
| 110 | pr_debug("md/raid0:%s: END\n", |
| 111 | mdname(mddev)); |
| 112 | break; |
| 113 | } |
| 114 | if (rdev2->sectors == rdev1->sectors) { |
| 115 | /* |
| 116 | * Not unique, don't count it as a new |
| 117 | * group |
| 118 | */ |
| 119 | pr_debug("md/raid0:%s: EQUAL\n", |
| 120 | mdname(mddev)); |
| 121 | c = 1; |
| 122 | break; |
| 123 | } |
| 124 | pr_debug("md/raid0:%s: NOT EQUAL\n", |
| 125 | mdname(mddev)); |
| 126 | } |
| 127 | if (!c) { |
| 128 | pr_debug("md/raid0:%s: ==> UNIQUE\n", |
| 129 | mdname(mddev)); |
| 130 | conf->nr_strip_zones++; |
| 131 | pr_debug("md/raid0:%s: %d zones\n", |
| 132 | mdname(mddev), conf->nr_strip_zones); |
| 133 | } |
| 134 | } |
| 135 | pr_debug("md/raid0:%s: FINAL %d zones\n", |
| 136 | mdname(mddev), conf->nr_strip_zones); |
| 137 | err = -ENOMEM; |
| 138 | conf->strip_zone = kzalloc(sizeof(struct strip_zone)* |
| 139 | conf->nr_strip_zones, GFP_KERNEL); |
| 140 | if (!conf->strip_zone) |
| 141 | goto abort; |
| 142 | conf->devlist = kzalloc(sizeof(struct md_rdev*)* |
| 143 | conf->nr_strip_zones*mddev->raid_disks, |
| 144 | GFP_KERNEL); |
| 145 | if (!conf->devlist) |
| 146 | goto abort; |
| 147 | |
| 148 | /* The first zone must contain all devices, so here we check that |
| 149 | * there is a proper alignment of slots to devices and find them all |
| 150 | */ |
| 151 | zone = &conf->strip_zone[0]; |
| 152 | cnt = 0; |
| 153 | smallest = NULL; |
| 154 | dev = conf->devlist; |
| 155 | err = -EINVAL; |
| 156 | rdev_for_each(rdev1, mddev) { |
| 157 | int j = rdev1->raid_disk; |
| 158 | |
| 159 | if (mddev->level == 10) { |
| 160 | /* taking over a raid10-n2 array */ |
| 161 | j /= 2; |
| 162 | rdev1->new_raid_disk = j; |
| 163 | } |
| 164 | |
| 165 | if (mddev->level == 1) { |
| 166 | /* taiking over a raid1 array- |
| 167 | * we have only one active disk |
| 168 | */ |
| 169 | j = 0; |
| 170 | rdev1->new_raid_disk = j; |
| 171 | } |
| 172 | |
| 173 | if (j < 0) { |
| 174 | printk(KERN_ERR |
| 175 | "md/raid0:%s: remove inactive devices before converting to RAID0\n", |
| 176 | mdname(mddev)); |
| 177 | goto abort; |
| 178 | } |
| 179 | if (j >= mddev->raid_disks) { |
| 180 | printk(KERN_ERR "md/raid0:%s: bad disk number %d - " |
| 181 | "aborting!\n", mdname(mddev), j); |
| 182 | goto abort; |
| 183 | } |
| 184 | if (dev[j]) { |
| 185 | printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " |
| 186 | "aborting!\n", mdname(mddev), j); |
| 187 | goto abort; |
| 188 | } |
| 189 | dev[j] = rdev1; |
| 190 | |
| 191 | if (mddev->queue) |
| 192 | disk_stack_limits(mddev->gendisk, rdev1->bdev, |
| 193 | rdev1->data_offset << 9); |
| 194 | |
| 195 | if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) |
| 196 | conf->has_merge_bvec = 1; |
| 197 | |
| 198 | if (!smallest || (rdev1->sectors < smallest->sectors)) |
| 199 | smallest = rdev1; |
| 200 | cnt++; |
| 201 | |
| 202 | if (blk_queue_discard(bdev_get_queue(rdev1->bdev))) |
| 203 | discard_supported = true; |
| 204 | } |
| 205 | if (cnt != mddev->raid_disks) { |
| 206 | printk(KERN_ERR "md/raid0:%s: too few disks (%d of %d) - " |
| 207 | "aborting!\n", mdname(mddev), cnt, mddev->raid_disks); |
| 208 | goto abort; |
| 209 | } |
| 210 | zone->nb_dev = cnt; |
| 211 | zone->zone_end = smallest->sectors * cnt; |
| 212 | |
| 213 | curr_zone_end = zone->zone_end; |
| 214 | |
| 215 | /* now do the other zones */ |
| 216 | for (i = 1; i < conf->nr_strip_zones; i++) |
| 217 | { |
| 218 | int j; |
| 219 | |
| 220 | zone = conf->strip_zone + i; |
| 221 | dev = conf->devlist + i * mddev->raid_disks; |
| 222 | |
| 223 | pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); |
| 224 | zone->dev_start = smallest->sectors; |
| 225 | smallest = NULL; |
| 226 | c = 0; |
| 227 | |
| 228 | for (j=0; j<cnt; j++) { |
| 229 | rdev = conf->devlist[j]; |
| 230 | if (rdev->sectors <= zone->dev_start) { |
| 231 | pr_debug("md/raid0:%s: checking %s ... nope\n", |
| 232 | mdname(mddev), |
| 233 | bdevname(rdev->bdev, b)); |
| 234 | continue; |
| 235 | } |
| 236 | pr_debug("md/raid0:%s: checking %s ..." |
| 237 | " contained as device %d\n", |
| 238 | mdname(mddev), |
| 239 | bdevname(rdev->bdev, b), c); |
| 240 | dev[c] = rdev; |
| 241 | c++; |
| 242 | if (!smallest || rdev->sectors < smallest->sectors) { |
| 243 | smallest = rdev; |
| 244 | pr_debug("md/raid0:%s: (%llu) is smallest!.\n", |
| 245 | mdname(mddev), |
| 246 | (unsigned long long)rdev->sectors); |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | zone->nb_dev = c; |
| 251 | sectors = (smallest->sectors - zone->dev_start) * c; |
| 252 | pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", |
| 253 | mdname(mddev), |
| 254 | zone->nb_dev, (unsigned long long)sectors); |
| 255 | |
| 256 | curr_zone_end += sectors; |
| 257 | zone->zone_end = curr_zone_end; |
| 258 | |
| 259 | pr_debug("md/raid0:%s: current zone start: %llu\n", |
| 260 | mdname(mddev), |
| 261 | (unsigned long long)smallest->sectors); |
| 262 | } |
| 263 | |
| 264 | /* |
| 265 | * now since we have the hard sector sizes, we can make sure |
| 266 | * chunk size is a multiple of that sector size |
| 267 | */ |
| 268 | if ((mddev->chunk_sectors << 9) % queue_logical_block_size(mddev->queue)) { |
| 269 | printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", |
| 270 | mdname(mddev), |
| 271 | mddev->chunk_sectors << 9); |
| 272 | goto abort; |
| 273 | } |
| 274 | |
| 275 | if (mddev->queue) { |
| 276 | blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); |
| 277 | blk_queue_io_opt(mddev->queue, |
| 278 | (mddev->chunk_sectors << 9) * mddev->raid_disks); |
| 279 | |
| 280 | if (!discard_supported) |
| 281 | queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); |
| 282 | else |
| 283 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); |
| 284 | } |
| 285 | |
| 286 | pr_debug("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 = ERR_PTR(err); |
| 295 | return err; |
| 296 | } |
| 297 | |
| 298 | /* Find the zone which holds a particular offset |
| 299 | * Update *sectorp to be an offset in that zone |
| 300 | */ |
| 301 | static struct strip_zone *find_zone(struct r0conf *conf, |
| 302 | sector_t *sectorp) |
| 303 | { |
| 304 | int i; |
| 305 | struct strip_zone *z = conf->strip_zone; |
| 306 | sector_t sector = *sectorp; |
| 307 | |
| 308 | for (i = 0; i < conf->nr_strip_zones; i++) |
| 309 | if (sector < z[i].zone_end) { |
| 310 | if (i) |
| 311 | *sectorp = sector - z[i-1].zone_end; |
| 312 | return z + i; |
| 313 | } |
| 314 | BUG(); |
| 315 | } |
| 316 | |
| 317 | /* |
| 318 | * remaps the bio to the target device. we separate two flows. |
| 319 | * power 2 flow and a general flow for the sake of performance |
| 320 | */ |
| 321 | static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, |
| 322 | sector_t sector, sector_t *sector_offset) |
| 323 | { |
| 324 | unsigned int sect_in_chunk; |
| 325 | sector_t chunk; |
| 326 | struct r0conf *conf = mddev->private; |
| 327 | int raid_disks = conf->strip_zone[0].nb_dev; |
| 328 | unsigned int chunk_sects = mddev->chunk_sectors; |
| 329 | |
| 330 | if (is_power_of_2(chunk_sects)) { |
| 331 | int chunksect_bits = ffz(~chunk_sects); |
| 332 | /* find the sector offset inside the chunk */ |
| 333 | sect_in_chunk = sector & (chunk_sects - 1); |
| 334 | sector >>= chunksect_bits; |
| 335 | /* chunk in zone */ |
| 336 | chunk = *sector_offset; |
| 337 | /* quotient is the chunk in real device*/ |
| 338 | sector_div(chunk, zone->nb_dev << chunksect_bits); |
| 339 | } else{ |
| 340 | sect_in_chunk = sector_div(sector, chunk_sects); |
| 341 | chunk = *sector_offset; |
| 342 | sector_div(chunk, chunk_sects * zone->nb_dev); |
| 343 | } |
| 344 | /* |
| 345 | * position the bio over the real device |
| 346 | * real sector = chunk in device + starting of zone |
| 347 | * + the position in the chunk |
| 348 | */ |
| 349 | *sector_offset = (chunk * chunk_sects) + sect_in_chunk; |
| 350 | return conf->devlist[(zone - conf->strip_zone)*raid_disks |
| 351 | + sector_div(sector, zone->nb_dev)]; |
| 352 | } |
| 353 | |
| 354 | /** |
| 355 | * raid0_mergeable_bvec -- tell bio layer if two requests can be merged |
| 356 | * @mddev: the md device |
| 357 | * @bvm: properties of new bio |
| 358 | * @biovec: the request that could be merged to it. |
| 359 | * |
| 360 | * Return amount of bytes we can accept at this offset |
| 361 | */ |
| 362 | static int raid0_mergeable_bvec(struct mddev *mddev, |
| 363 | struct bvec_merge_data *bvm, |
| 364 | struct bio_vec *biovec) |
| 365 | { |
| 366 | struct r0conf *conf = mddev->private; |
| 367 | sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); |
| 368 | sector_t sector_offset = sector; |
| 369 | int max; |
| 370 | unsigned int chunk_sectors = mddev->chunk_sectors; |
| 371 | unsigned int bio_sectors = bvm->bi_size >> 9; |
| 372 | struct strip_zone *zone; |
| 373 | struct md_rdev *rdev; |
| 374 | struct request_queue *subq; |
| 375 | |
| 376 | if (is_power_of_2(chunk_sectors)) |
| 377 | max = (chunk_sectors - ((sector & (chunk_sectors-1)) |
| 378 | + bio_sectors)) << 9; |
| 379 | else |
| 380 | max = (chunk_sectors - (sector_div(sector, chunk_sectors) |
| 381 | + bio_sectors)) << 9; |
| 382 | if (max < 0) |
| 383 | max = 0; /* bio_add cannot handle a negative return */ |
| 384 | if (max <= biovec->bv_len && bio_sectors == 0) |
| 385 | return biovec->bv_len; |
| 386 | if (max < biovec->bv_len) |
| 387 | /* too small already, no need to check further */ |
| 388 | return max; |
| 389 | if (!conf->has_merge_bvec) |
| 390 | return max; |
| 391 | |
| 392 | /* May need to check subordinate device */ |
| 393 | sector = sector_offset; |
| 394 | zone = find_zone(mddev->private, §or_offset); |
| 395 | rdev = map_sector(mddev, zone, sector, §or_offset); |
| 396 | subq = bdev_get_queue(rdev->bdev); |
| 397 | if (subq->merge_bvec_fn) { |
| 398 | bvm->bi_bdev = rdev->bdev; |
| 399 | bvm->bi_sector = sector_offset + zone->dev_start + |
| 400 | rdev->data_offset; |
| 401 | return min(max, subq->merge_bvec_fn(subq, bvm, biovec)); |
| 402 | } else |
| 403 | return max; |
| 404 | } |
| 405 | |
| 406 | static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) |
| 407 | { |
| 408 | sector_t array_sectors = 0; |
| 409 | struct md_rdev *rdev; |
| 410 | |
| 411 | WARN_ONCE(sectors || raid_disks, |
| 412 | "%s does not support generic reshape\n", __func__); |
| 413 | |
| 414 | rdev_for_each(rdev, mddev) |
| 415 | array_sectors += (rdev->sectors & |
| 416 | ~(sector_t)(mddev->chunk_sectors-1)); |
| 417 | |
| 418 | return array_sectors; |
| 419 | } |
| 420 | |
| 421 | static void raid0_free(struct mddev *mddev, void *priv); |
| 422 | |
| 423 | static int raid0_run(struct mddev *mddev) |
| 424 | { |
| 425 | struct r0conf *conf; |
| 426 | int ret; |
| 427 | |
| 428 | if (mddev->chunk_sectors == 0) { |
| 429 | printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", |
| 430 | mdname(mddev)); |
| 431 | return -EINVAL; |
| 432 | } |
| 433 | if (md_check_no_bitmap(mddev)) |
| 434 | return -EINVAL; |
| 435 | |
| 436 | if (mddev->queue) { |
| 437 | blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); |
| 438 | blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors); |
| 439 | blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors); |
| 440 | } |
| 441 | |
| 442 | /* if private is not null, we are here after takeover */ |
| 443 | if (mddev->private == NULL) { |
| 444 | ret = create_strip_zones(mddev, &conf); |
| 445 | if (ret < 0) |
| 446 | return ret; |
| 447 | mddev->private = conf; |
| 448 | } |
| 449 | conf = mddev->private; |
| 450 | |
| 451 | /* calculate array device size */ |
| 452 | md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); |
| 453 | |
| 454 | printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", |
| 455 | mdname(mddev), |
| 456 | (unsigned long long)mddev->array_sectors); |
| 457 | |
| 458 | if (mddev->queue) { |
| 459 | /* calculate the max read-ahead size. |
| 460 | * For read-ahead of large files to be effective, we need to |
| 461 | * readahead at least twice a whole stripe. i.e. number of devices |
| 462 | * multiplied by chunk size times 2. |
| 463 | * If an individual device has an ra_pages greater than the |
| 464 | * chunk size, then we will not drive that device as hard as it |
| 465 | * wants. We consider this a configuration error: a larger |
| 466 | * chunksize should be used in that case. |
| 467 | */ |
| 468 | int stripe = mddev->raid_disks * |
| 469 | (mddev->chunk_sectors << 9) / PAGE_SIZE; |
| 470 | if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) |
| 471 | mddev->queue->backing_dev_info.ra_pages = 2* stripe; |
| 472 | } |
| 473 | |
| 474 | dump_zones(mddev); |
| 475 | |
| 476 | ret = md_integrity_register(mddev); |
| 477 | |
| 478 | return ret; |
| 479 | } |
| 480 | |
| 481 | static void raid0_free(struct mddev *mddev, void *priv) |
| 482 | { |
| 483 | struct r0conf *conf = priv; |
| 484 | |
| 485 | kfree(conf->strip_zone); |
| 486 | kfree(conf->devlist); |
| 487 | kfree(conf); |
| 488 | } |
| 489 | |
| 490 | /* |
| 491 | * Is io distribute over 1 or more chunks ? |
| 492 | */ |
| 493 | static inline int is_io_in_chunk_boundary(struct mddev *mddev, |
| 494 | unsigned int chunk_sects, struct bio *bio) |
| 495 | { |
| 496 | if (likely(is_power_of_2(chunk_sects))) { |
| 497 | return chunk_sects >= |
| 498 | ((bio->bi_iter.bi_sector & (chunk_sects-1)) |
| 499 | + bio_sectors(bio)); |
| 500 | } else{ |
| 501 | sector_t sector = bio->bi_iter.bi_sector; |
| 502 | return chunk_sects >= (sector_div(sector, chunk_sects) |
| 503 | + bio_sectors(bio)); |
| 504 | } |
| 505 | } |
| 506 | |
| 507 | static void raid0_make_request(struct mddev *mddev, struct bio *bio) |
| 508 | { |
| 509 | struct strip_zone *zone; |
| 510 | struct md_rdev *tmp_dev; |
| 511 | struct bio *split; |
| 512 | |
| 513 | if (unlikely(bio->bi_rw & REQ_FLUSH)) { |
| 514 | md_flush_request(mddev, bio); |
| 515 | return; |
| 516 | } |
| 517 | |
| 518 | do { |
| 519 | sector_t sector = bio->bi_iter.bi_sector; |
| 520 | unsigned chunk_sects = mddev->chunk_sectors; |
| 521 | |
| 522 | unsigned sectors = chunk_sects - |
| 523 | (likely(is_power_of_2(chunk_sects)) |
| 524 | ? (sector & (chunk_sects-1)) |
| 525 | : sector_div(sector, chunk_sects)); |
| 526 | |
| 527 | if (sectors < bio_sectors(bio)) { |
| 528 | split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set); |
| 529 | bio_chain(split, bio); |
| 530 | } else { |
| 531 | split = bio; |
| 532 | } |
| 533 | |
| 534 | sector = bio->bi_iter.bi_sector; |
| 535 | zone = find_zone(mddev->private, §or); |
| 536 | tmp_dev = map_sector(mddev, zone, sector, §or); |
| 537 | split->bi_bdev = tmp_dev->bdev; |
| 538 | split->bi_iter.bi_sector = sector + zone->dev_start + |
| 539 | tmp_dev->data_offset; |
| 540 | |
| 541 | if (unlikely((split->bi_rw & REQ_DISCARD) && |
| 542 | !blk_queue_discard(bdev_get_queue(split->bi_bdev)))) { |
| 543 | /* Just ignore it */ |
| 544 | bio_endio(split, 0); |
| 545 | } else |
| 546 | generic_make_request(split); |
| 547 | } while (split != bio); |
| 548 | } |
| 549 | |
| 550 | static void raid0_status(struct seq_file *seq, struct mddev *mddev) |
| 551 | { |
| 552 | seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2); |
| 553 | return; |
| 554 | } |
| 555 | |
| 556 | static void *raid0_takeover_raid45(struct mddev *mddev) |
| 557 | { |
| 558 | struct md_rdev *rdev; |
| 559 | struct r0conf *priv_conf; |
| 560 | |
| 561 | if (mddev->degraded != 1) { |
| 562 | printk(KERN_ERR "md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n", |
| 563 | mdname(mddev), |
| 564 | mddev->degraded); |
| 565 | return ERR_PTR(-EINVAL); |
| 566 | } |
| 567 | |
| 568 | rdev_for_each(rdev, mddev) { |
| 569 | /* check slot number for a disk */ |
| 570 | if (rdev->raid_disk == mddev->raid_disks-1) { |
| 571 | printk(KERN_ERR "md/raid0:%s: raid5 must have missing parity disk!\n", |
| 572 | mdname(mddev)); |
| 573 | return ERR_PTR(-EINVAL); |
| 574 | } |
| 575 | rdev->sectors = mddev->dev_sectors; |
| 576 | } |
| 577 | |
| 578 | /* Set new parameters */ |
| 579 | mddev->new_level = 0; |
| 580 | mddev->new_layout = 0; |
| 581 | mddev->new_chunk_sectors = mddev->chunk_sectors; |
| 582 | mddev->raid_disks--; |
| 583 | mddev->delta_disks = -1; |
| 584 | /* make sure it will be not marked as dirty */ |
| 585 | mddev->recovery_cp = MaxSector; |
| 586 | |
| 587 | create_strip_zones(mddev, &priv_conf); |
| 588 | return priv_conf; |
| 589 | } |
| 590 | |
| 591 | static void *raid0_takeover_raid10(struct mddev *mddev) |
| 592 | { |
| 593 | struct r0conf *priv_conf; |
| 594 | |
| 595 | /* Check layout: |
| 596 | * - far_copies must be 1 |
| 597 | * - near_copies must be 2 |
| 598 | * - disks number must be even |
| 599 | * - all mirrors must be already degraded |
| 600 | */ |
| 601 | if (mddev->layout != ((1 << 8) + 2)) { |
| 602 | printk(KERN_ERR "md/raid0:%s:: Raid0 cannot takover layout: 0x%x\n", |
| 603 | mdname(mddev), |
| 604 | mddev->layout); |
| 605 | return ERR_PTR(-EINVAL); |
| 606 | } |
| 607 | if (mddev->raid_disks & 1) { |
| 608 | printk(KERN_ERR "md/raid0:%s: Raid0 cannot takover Raid10 with odd disk number.\n", |
| 609 | mdname(mddev)); |
| 610 | return ERR_PTR(-EINVAL); |
| 611 | } |
| 612 | if (mddev->degraded != (mddev->raid_disks>>1)) { |
| 613 | printk(KERN_ERR "md/raid0:%s: All mirrors must be already degraded!\n", |
| 614 | mdname(mddev)); |
| 615 | return ERR_PTR(-EINVAL); |
| 616 | } |
| 617 | |
| 618 | /* Set new parameters */ |
| 619 | mddev->new_level = 0; |
| 620 | mddev->new_layout = 0; |
| 621 | mddev->new_chunk_sectors = mddev->chunk_sectors; |
| 622 | mddev->delta_disks = - mddev->raid_disks / 2; |
| 623 | mddev->raid_disks += mddev->delta_disks; |
| 624 | mddev->degraded = 0; |
| 625 | /* make sure it will be not marked as dirty */ |
| 626 | mddev->recovery_cp = MaxSector; |
| 627 | |
| 628 | create_strip_zones(mddev, &priv_conf); |
| 629 | return priv_conf; |
| 630 | } |
| 631 | |
| 632 | static void *raid0_takeover_raid1(struct mddev *mddev) |
| 633 | { |
| 634 | struct r0conf *priv_conf; |
| 635 | int chunksect; |
| 636 | |
| 637 | /* Check layout: |
| 638 | * - (N - 1) mirror drives must be already faulty |
| 639 | */ |
| 640 | if ((mddev->raid_disks - 1) != mddev->degraded) { |
| 641 | printk(KERN_ERR "md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n", |
| 642 | mdname(mddev)); |
| 643 | return ERR_PTR(-EINVAL); |
| 644 | } |
| 645 | |
| 646 | /* |
| 647 | * a raid1 doesn't have the notion of chunk size, so |
| 648 | * figure out the largest suitable size we can use. |
| 649 | */ |
| 650 | chunksect = 64 * 2; /* 64K by default */ |
| 651 | |
| 652 | /* The array must be an exact multiple of chunksize */ |
| 653 | while (chunksect && (mddev->array_sectors & (chunksect - 1))) |
| 654 | chunksect >>= 1; |
| 655 | |
| 656 | if ((chunksect << 9) < PAGE_SIZE) |
| 657 | /* array size does not allow a suitable chunk size */ |
| 658 | return ERR_PTR(-EINVAL); |
| 659 | |
| 660 | /* Set new parameters */ |
| 661 | mddev->new_level = 0; |
| 662 | mddev->new_layout = 0; |
| 663 | mddev->new_chunk_sectors = chunksect; |
| 664 | mddev->chunk_sectors = chunksect; |
| 665 | mddev->delta_disks = 1 - mddev->raid_disks; |
| 666 | mddev->raid_disks = 1; |
| 667 | /* make sure it will be not marked as dirty */ |
| 668 | mddev->recovery_cp = MaxSector; |
| 669 | |
| 670 | create_strip_zones(mddev, &priv_conf); |
| 671 | return priv_conf; |
| 672 | } |
| 673 | |
| 674 | static void *raid0_takeover(struct mddev *mddev) |
| 675 | { |
| 676 | /* raid0 can take over: |
| 677 | * raid4 - if all data disks are active. |
| 678 | * raid5 - providing it is Raid4 layout and one disk is faulty |
| 679 | * raid10 - assuming we have all necessary active disks |
| 680 | * raid1 - with (N -1) mirror drives faulty |
| 681 | */ |
| 682 | |
| 683 | if (mddev->bitmap) { |
| 684 | printk(KERN_ERR "md/raid0: %s: cannot takeover array with bitmap\n", |
| 685 | mdname(mddev)); |
| 686 | return ERR_PTR(-EBUSY); |
| 687 | } |
| 688 | if (mddev->level == 4) |
| 689 | return raid0_takeover_raid45(mddev); |
| 690 | |
| 691 | if (mddev->level == 5) { |
| 692 | if (mddev->layout == ALGORITHM_PARITY_N) |
| 693 | return raid0_takeover_raid45(mddev); |
| 694 | |
| 695 | printk(KERN_ERR "md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n", |
| 696 | mdname(mddev), ALGORITHM_PARITY_N); |
| 697 | } |
| 698 | |
| 699 | if (mddev->level == 10) |
| 700 | return raid0_takeover_raid10(mddev); |
| 701 | |
| 702 | if (mddev->level == 1) |
| 703 | return raid0_takeover_raid1(mddev); |
| 704 | |
| 705 | printk(KERN_ERR "Takeover from raid%i to raid0 not supported\n", |
| 706 | mddev->level); |
| 707 | |
| 708 | return ERR_PTR(-EINVAL); |
| 709 | } |
| 710 | |
| 711 | static void raid0_quiesce(struct mddev *mddev, int state) |
| 712 | { |
| 713 | } |
| 714 | |
| 715 | static struct md_personality raid0_personality= |
| 716 | { |
| 717 | .name = "raid0", |
| 718 | .level = 0, |
| 719 | .owner = THIS_MODULE, |
| 720 | .make_request = raid0_make_request, |
| 721 | .run = raid0_run, |
| 722 | .free = raid0_free, |
| 723 | .status = raid0_status, |
| 724 | .size = raid0_size, |
| 725 | .takeover = raid0_takeover, |
| 726 | .quiesce = raid0_quiesce, |
| 727 | .congested = raid0_congested, |
| 728 | .mergeable_bvec = raid0_mergeable_bvec, |
| 729 | }; |
| 730 | |
| 731 | static int __init raid0_init (void) |
| 732 | { |
| 733 | return register_md_personality (&raid0_personality); |
| 734 | } |
| 735 | |
| 736 | static void raid0_exit (void) |
| 737 | { |
| 738 | unregister_md_personality (&raid0_personality); |
| 739 | } |
| 740 | |
| 741 | module_init(raid0_init); |
| 742 | module_exit(raid0_exit); |
| 743 | MODULE_LICENSE("GPL"); |
| 744 | MODULE_DESCRIPTION("RAID0 (striping) personality for MD"); |
| 745 | MODULE_ALIAS("md-personality-2"); /* RAID0 */ |
| 746 | MODULE_ALIAS("md-raid0"); |
| 747 | MODULE_ALIAS("md-level-0"); |