2 raid0.c : Multiple Devices driver for Linux
3 Copyright (C) 1994-96 Marc ZYNGIER
4 <zyngier@ufr-info-p7.ibp.fr> or
6 Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
8 RAID-0 management functions.
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)
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.
20 #include <linux/blkdev.h>
21 #include <linux/seq_file.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <trace/events/block.h>
29 static int default_layout = 0;
30 module_param(default_layout, int, 0644);
32 #define UNSUPPORTED_MDDEV_FLAGS \
33 ((1L << MD_HAS_JOURNAL) | \
34 (1L << MD_JOURNAL_CLEAN) | \
35 (1L << MD_FAILFAST_SUPPORTED) |\
36 (1L << MD_HAS_PPL) | \
37 (1L << MD_HAS_MULTIPLE_PPLS))
39 static int raid0_congested(struct mddev *mddev, int bits)
41 struct r0conf *conf = mddev->private;
42 struct md_rdev **devlist = conf->devlist;
43 int raid_disks = conf->strip_zone[0].nb_dev;
46 for (i = 0; i < raid_disks && !ret ; i++) {
47 struct request_queue *q = bdev_get_queue(devlist[i]->bdev);
49 ret |= bdi_congested(q->backing_dev_info, bits);
55 * inform the user of the raid configuration
57 static void dump_zones(struct mddev *mddev)
60 sector_t zone_size = 0;
61 sector_t zone_start = 0;
62 char b[BDEVNAME_SIZE];
63 struct r0conf *conf = mddev->private;
64 int raid_disks = conf->strip_zone[0].nb_dev;
65 pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
67 conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
68 for (j = 0; j < conf->nr_strip_zones; j++) {
72 for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
73 len += scnprintf(line+len, 200-len, "%s%s", k?"/":"",
74 bdevname(conf->devlist[j*raid_disks
76 pr_debug("md: zone%d=[%s]\n", j, line);
78 zone_size = conf->strip_zone[j].zone_end - zone_start;
79 pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n",
80 (unsigned long long)zone_start>>1,
81 (unsigned long long)conf->strip_zone[j].dev_start>>1,
82 (unsigned long long)zone_size>>1);
83 zone_start = conf->strip_zone[j].zone_end;
87 static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
90 sector_t curr_zone_end, sectors;
91 struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
92 struct strip_zone *zone;
94 char b[BDEVNAME_SIZE];
95 char b2[BDEVNAME_SIZE];
96 struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
97 unsigned blksize = 512;
99 *private_conf = ERR_PTR(-ENOMEM);
102 rdev_for_each(rdev1, mddev) {
103 pr_debug("md/raid0:%s: looking at %s\n",
105 bdevname(rdev1->bdev, b));
108 /* round size to chunk_size */
109 sectors = rdev1->sectors;
110 sector_div(sectors, mddev->chunk_sectors);
111 rdev1->sectors = sectors * mddev->chunk_sectors;
113 blksize = max(blksize, queue_logical_block_size(
114 rdev1->bdev->bd_disk->queue));
116 rdev_for_each(rdev2, mddev) {
117 pr_debug("md/raid0:%s: comparing %s(%llu)"
120 bdevname(rdev1->bdev,b),
121 (unsigned long long)rdev1->sectors,
122 bdevname(rdev2->bdev,b2),
123 (unsigned long long)rdev2->sectors);
124 if (rdev2 == rdev1) {
125 pr_debug("md/raid0:%s: END\n",
129 if (rdev2->sectors == rdev1->sectors) {
131 * Not unique, don't count it as a new
134 pr_debug("md/raid0:%s: EQUAL\n",
139 pr_debug("md/raid0:%s: NOT EQUAL\n",
143 pr_debug("md/raid0:%s: ==> UNIQUE\n",
145 conf->nr_strip_zones++;
146 pr_debug("md/raid0:%s: %d zones\n",
147 mdname(mddev), conf->nr_strip_zones);
150 pr_debug("md/raid0:%s: FINAL %d zones\n",
151 mdname(mddev), conf->nr_strip_zones);
154 * now since we have the hard sector sizes, we can make sure
155 * chunk size is a multiple of that sector size
157 if ((mddev->chunk_sectors << 9) % blksize) {
158 pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
160 mddev->chunk_sectors << 9, blksize);
166 conf->strip_zone = kcalloc(conf->nr_strip_zones,
167 sizeof(struct strip_zone),
169 if (!conf->strip_zone)
171 conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *),
172 conf->nr_strip_zones,
178 /* The first zone must contain all devices, so here we check that
179 * there is a proper alignment of slots to devices and find them all
181 zone = &conf->strip_zone[0];
186 rdev_for_each(rdev1, mddev) {
187 int j = rdev1->raid_disk;
189 if (mddev->level == 10) {
190 /* taking over a raid10-n2 array */
192 rdev1->new_raid_disk = j;
195 if (mddev->level == 1) {
196 /* taiking over a raid1 array-
197 * we have only one active disk
200 rdev1->new_raid_disk = j;
204 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
208 if (j >= mddev->raid_disks) {
209 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
214 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
220 if (!smallest || (rdev1->sectors < smallest->sectors))
224 if (cnt != mddev->raid_disks) {
225 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
226 mdname(mddev), cnt, mddev->raid_disks);
230 zone->zone_end = smallest->sectors * cnt;
232 curr_zone_end = zone->zone_end;
234 /* now do the other zones */
235 for (i = 1; i < conf->nr_strip_zones; i++)
239 zone = conf->strip_zone + i;
240 dev = conf->devlist + i * mddev->raid_disks;
242 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
243 zone->dev_start = smallest->sectors;
247 for (j=0; j<cnt; j++) {
248 rdev = conf->devlist[j];
249 if (rdev->sectors <= zone->dev_start) {
250 pr_debug("md/raid0:%s: checking %s ... nope\n",
252 bdevname(rdev->bdev, b));
255 pr_debug("md/raid0:%s: checking %s ..."
256 " contained as device %d\n",
258 bdevname(rdev->bdev, b), c);
261 if (!smallest || rdev->sectors < smallest->sectors) {
263 pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
265 (unsigned long long)rdev->sectors);
270 sectors = (smallest->sectors - zone->dev_start) * c;
271 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
273 zone->nb_dev, (unsigned long long)sectors);
275 curr_zone_end += sectors;
276 zone->zone_end = curr_zone_end;
278 pr_debug("md/raid0:%s: current zone start: %llu\n",
280 (unsigned long long)smallest->sectors);
283 if (conf->nr_strip_zones == 1 || conf->strip_zone[1].nb_dev == 1) {
284 conf->layout = RAID0_ORIG_LAYOUT;
285 } else if (mddev->layout == RAID0_ORIG_LAYOUT ||
286 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
287 conf->layout = mddev->layout;
288 } else if (default_layout == RAID0_ORIG_LAYOUT ||
289 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
290 conf->layout = default_layout;
292 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n",
294 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n");
299 pr_debug("md/raid0:%s: done.\n", mdname(mddev));
300 *private_conf = conf;
304 kfree(conf->strip_zone);
305 kfree(conf->devlist);
307 *private_conf = ERR_PTR(err);
311 /* Find the zone which holds a particular offset
312 * Update *sectorp to be an offset in that zone
314 static struct strip_zone *find_zone(struct r0conf *conf,
318 struct strip_zone *z = conf->strip_zone;
319 sector_t sector = *sectorp;
321 for (i = 0; i < conf->nr_strip_zones; i++)
322 if (sector < z[i].zone_end) {
324 *sectorp = sector - z[i-1].zone_end;
331 * remaps the bio to the target device. we separate two flows.
332 * power 2 flow and a general flow for the sake of performance
334 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
335 sector_t sector, sector_t *sector_offset)
337 unsigned int sect_in_chunk;
339 struct r0conf *conf = mddev->private;
340 int raid_disks = conf->strip_zone[0].nb_dev;
341 unsigned int chunk_sects = mddev->chunk_sectors;
343 if (is_power_of_2(chunk_sects)) {
344 int chunksect_bits = ffz(~chunk_sects);
345 /* find the sector offset inside the chunk */
346 sect_in_chunk = sector & (chunk_sects - 1);
347 sector >>= chunksect_bits;
349 chunk = *sector_offset;
350 /* quotient is the chunk in real device*/
351 sector_div(chunk, zone->nb_dev << chunksect_bits);
353 sect_in_chunk = sector_div(sector, chunk_sects);
354 chunk = *sector_offset;
355 sector_div(chunk, chunk_sects * zone->nb_dev);
358 * position the bio over the real device
359 * real sector = chunk in device + starting of zone
360 * + the position in the chunk
362 *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
363 return conf->devlist[(zone - conf->strip_zone)*raid_disks
364 + sector_div(sector, zone->nb_dev)];
367 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
369 sector_t array_sectors = 0;
370 struct md_rdev *rdev;
372 WARN_ONCE(sectors || raid_disks,
373 "%s does not support generic reshape\n", __func__);
375 rdev_for_each(rdev, mddev)
376 array_sectors += (rdev->sectors &
377 ~(sector_t)(mddev->chunk_sectors-1));
379 return array_sectors;
382 static void raid0_free(struct mddev *mddev, void *priv);
384 static int raid0_run(struct mddev *mddev)
389 if (mddev->chunk_sectors == 0) {
390 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
393 if (md_check_no_bitmap(mddev))
396 /* if private is not null, we are here after takeover */
397 if (mddev->private == NULL) {
398 ret = create_strip_zones(mddev, &conf);
401 mddev->private = conf;
403 conf = mddev->private;
405 struct md_rdev *rdev;
406 bool discard_supported = false;
408 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
409 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
410 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
411 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
413 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
414 blk_queue_io_opt(mddev->queue,
415 (mddev->chunk_sectors << 9) * mddev->raid_disks);
417 rdev_for_each(rdev, mddev) {
418 disk_stack_limits(mddev->gendisk, rdev->bdev,
419 rdev->data_offset << 9);
420 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
421 discard_supported = true;
423 if (!discard_supported)
424 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, mddev->queue);
426 blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
429 /* calculate array device size */
430 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
432 pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
434 (unsigned long long)mddev->array_sectors);
437 /* calculate the max read-ahead size.
438 * For read-ahead of large files to be effective, we need to
439 * readahead at least twice a whole stripe. i.e. number of devices
440 * multiplied by chunk size times 2.
441 * If an individual device has an ra_pages greater than the
442 * chunk size, then we will not drive that device as hard as it
443 * wants. We consider this a configuration error: a larger
444 * chunksize should be used in that case.
446 int stripe = mddev->raid_disks *
447 (mddev->chunk_sectors << 9) / PAGE_SIZE;
448 if (mddev->queue->backing_dev_info->ra_pages < 2* stripe)
449 mddev->queue->backing_dev_info->ra_pages = 2* stripe;
454 ret = md_integrity_register(mddev);
459 static void raid0_free(struct mddev *mddev, void *priv)
461 struct r0conf *conf = priv;
463 kfree(conf->strip_zone);
464 kfree(conf->devlist);
469 * Is io distribute over 1 or more chunks ?
471 static inline int is_io_in_chunk_boundary(struct mddev *mddev,
472 unsigned int chunk_sects, struct bio *bio)
474 if (likely(is_power_of_2(chunk_sects))) {
475 return chunk_sects >=
476 ((bio->bi_iter.bi_sector & (chunk_sects-1))
479 sector_t sector = bio->bi_iter.bi_sector;
480 return chunk_sects >= (sector_div(sector, chunk_sects)
485 static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
487 struct r0conf *conf = mddev->private;
488 struct strip_zone *zone;
489 sector_t start = bio->bi_iter.bi_sector;
491 unsigned int stripe_size;
492 sector_t first_stripe_index, last_stripe_index;
493 sector_t start_disk_offset;
494 unsigned int start_disk_index;
495 sector_t end_disk_offset;
496 unsigned int end_disk_index;
499 zone = find_zone(conf, &start);
501 if (bio_end_sector(bio) > zone->zone_end) {
502 struct bio *split = bio_split(bio,
503 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
505 bio_chain(split, bio);
506 generic_make_request(bio);
508 end = zone->zone_end;
510 end = bio_end_sector(bio);
512 if (zone != conf->strip_zone)
513 end = end - zone[-1].zone_end;
515 /* Now start and end is the offset in zone */
516 stripe_size = zone->nb_dev * mddev->chunk_sectors;
518 first_stripe_index = start;
519 sector_div(first_stripe_index, stripe_size);
520 last_stripe_index = end;
521 sector_div(last_stripe_index, stripe_size);
523 start_disk_index = (int)(start - first_stripe_index * stripe_size) /
524 mddev->chunk_sectors;
525 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
526 mddev->chunk_sectors) +
527 first_stripe_index * mddev->chunk_sectors;
528 end_disk_index = (int)(end - last_stripe_index * stripe_size) /
529 mddev->chunk_sectors;
530 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
531 mddev->chunk_sectors) +
532 last_stripe_index * mddev->chunk_sectors;
534 for (disk = 0; disk < zone->nb_dev; disk++) {
535 sector_t dev_start, dev_end;
536 struct bio *discard_bio = NULL;
537 struct md_rdev *rdev;
539 if (disk < start_disk_index)
540 dev_start = (first_stripe_index + 1) *
541 mddev->chunk_sectors;
542 else if (disk > start_disk_index)
543 dev_start = first_stripe_index * mddev->chunk_sectors;
545 dev_start = start_disk_offset;
547 if (disk < end_disk_index)
548 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
549 else if (disk > end_disk_index)
550 dev_end = last_stripe_index * mddev->chunk_sectors;
552 dev_end = end_disk_offset;
554 if (dev_end <= dev_start)
557 rdev = conf->devlist[(zone - conf->strip_zone) *
558 conf->strip_zone[0].nb_dev + disk];
559 if (__blkdev_issue_discard(rdev->bdev,
560 dev_start + zone->dev_start + rdev->data_offset,
561 dev_end - dev_start, GFP_NOIO, 0, &discard_bio) ||
564 bio_chain(discard_bio, bio);
565 bio_clone_blkcg_association(discard_bio, bio);
567 trace_block_bio_remap(bdev_get_queue(rdev->bdev),
568 discard_bio, disk_devt(mddev->gendisk),
569 bio->bi_iter.bi_sector);
570 bio_clear_flag(bio, BIO_QUEUE_ENTERED);
571 generic_make_request(discard_bio);
576 static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
578 struct r0conf *conf = mddev->private;
579 struct strip_zone *zone;
580 struct md_rdev *tmp_dev;
583 sector_t orig_sector;
584 unsigned chunk_sects;
587 if (unlikely(bio->bi_opf & REQ_PREFLUSH)
588 && md_flush_request(mddev, bio))
591 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
592 raid0_handle_discard(mddev, bio);
596 bio_sector = bio->bi_iter.bi_sector;
598 chunk_sects = mddev->chunk_sectors;
600 sectors = chunk_sects -
601 (likely(is_power_of_2(chunk_sects))
602 ? (sector & (chunk_sects-1))
603 : sector_div(sector, chunk_sects));
605 /* Restore due to sector_div */
608 if (sectors < bio_sectors(bio)) {
609 struct bio *split = bio_split(bio, sectors, GFP_NOIO,
611 bio_chain(split, bio);
612 generic_make_request(bio);
616 orig_sector = sector;
617 zone = find_zone(mddev->private, §or);
618 switch (conf->layout) {
619 case RAID0_ORIG_LAYOUT:
620 tmp_dev = map_sector(mddev, zone, orig_sector, §or);
622 case RAID0_ALT_MULTIZONE_LAYOUT:
623 tmp_dev = map_sector(mddev, zone, sector, §or);
626 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
631 bio_set_dev(bio, tmp_dev->bdev);
632 bio->bi_iter.bi_sector = sector + zone->dev_start +
633 tmp_dev->data_offset;
636 trace_block_bio_remap(bio->bi_disk->queue, bio,
637 disk_devt(mddev->gendisk), bio_sector);
638 mddev_check_writesame(mddev, bio);
639 mddev_check_write_zeroes(mddev, bio);
640 bio_clear_flag(bio, BIO_QUEUE_ENTERED);
641 generic_make_request(bio);
645 static void raid0_status(struct seq_file *seq, struct mddev *mddev)
647 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
651 static void *raid0_takeover_raid45(struct mddev *mddev)
653 struct md_rdev *rdev;
654 struct r0conf *priv_conf;
656 if (mddev->degraded != 1) {
657 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
660 return ERR_PTR(-EINVAL);
663 rdev_for_each(rdev, mddev) {
664 /* check slot number for a disk */
665 if (rdev->raid_disk == mddev->raid_disks-1) {
666 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
668 return ERR_PTR(-EINVAL);
670 rdev->sectors = mddev->dev_sectors;
673 /* Set new parameters */
674 mddev->new_level = 0;
675 mddev->new_layout = 0;
676 mddev->new_chunk_sectors = mddev->chunk_sectors;
678 mddev->delta_disks = -1;
679 /* make sure it will be not marked as dirty */
680 mddev->recovery_cp = MaxSector;
681 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
683 create_strip_zones(mddev, &priv_conf);
688 static void *raid0_takeover_raid10(struct mddev *mddev)
690 struct r0conf *priv_conf;
693 * - far_copies must be 1
694 * - near_copies must be 2
695 * - disks number must be even
696 * - all mirrors must be already degraded
698 if (mddev->layout != ((1 << 8) + 2)) {
699 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
702 return ERR_PTR(-EINVAL);
704 if (mddev->raid_disks & 1) {
705 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
707 return ERR_PTR(-EINVAL);
709 if (mddev->degraded != (mddev->raid_disks>>1)) {
710 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
712 return ERR_PTR(-EINVAL);
715 /* Set new parameters */
716 mddev->new_level = 0;
717 mddev->new_layout = 0;
718 mddev->new_chunk_sectors = mddev->chunk_sectors;
719 mddev->delta_disks = - mddev->raid_disks / 2;
720 mddev->raid_disks += mddev->delta_disks;
722 /* make sure it will be not marked as dirty */
723 mddev->recovery_cp = MaxSector;
724 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
726 create_strip_zones(mddev, &priv_conf);
730 static void *raid0_takeover_raid1(struct mddev *mddev)
732 struct r0conf *priv_conf;
736 * - (N - 1) mirror drives must be already faulty
738 if ((mddev->raid_disks - 1) != mddev->degraded) {
739 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
741 return ERR_PTR(-EINVAL);
745 * a raid1 doesn't have the notion of chunk size, so
746 * figure out the largest suitable size we can use.
748 chunksect = 64 * 2; /* 64K by default */
750 /* The array must be an exact multiple of chunksize */
751 while (chunksect && (mddev->array_sectors & (chunksect - 1)))
754 if ((chunksect << 9) < PAGE_SIZE)
755 /* array size does not allow a suitable chunk size */
756 return ERR_PTR(-EINVAL);
758 /* Set new parameters */
759 mddev->new_level = 0;
760 mddev->new_layout = 0;
761 mddev->new_chunk_sectors = chunksect;
762 mddev->chunk_sectors = chunksect;
763 mddev->delta_disks = 1 - mddev->raid_disks;
764 mddev->raid_disks = 1;
765 /* make sure it will be not marked as dirty */
766 mddev->recovery_cp = MaxSector;
767 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
769 create_strip_zones(mddev, &priv_conf);
773 static void *raid0_takeover(struct mddev *mddev)
775 /* raid0 can take over:
776 * raid4 - if all data disks are active.
777 * raid5 - providing it is Raid4 layout and one disk is faulty
778 * raid10 - assuming we have all necessary active disks
779 * raid1 - with (N -1) mirror drives faulty
783 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
785 return ERR_PTR(-EBUSY);
787 if (mddev->level == 4)
788 return raid0_takeover_raid45(mddev);
790 if (mddev->level == 5) {
791 if (mddev->layout == ALGORITHM_PARITY_N)
792 return raid0_takeover_raid45(mddev);
794 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
795 mdname(mddev), ALGORITHM_PARITY_N);
798 if (mddev->level == 10)
799 return raid0_takeover_raid10(mddev);
801 if (mddev->level == 1)
802 return raid0_takeover_raid1(mddev);
804 pr_warn("Takeover from raid%i to raid0 not supported\n",
807 return ERR_PTR(-EINVAL);
810 static void raid0_quiesce(struct mddev *mddev, int quiesce)
814 static struct md_personality raid0_personality=
818 .owner = THIS_MODULE,
819 .make_request = raid0_make_request,
822 .status = raid0_status,
824 .takeover = raid0_takeover,
825 .quiesce = raid0_quiesce,
826 .congested = raid0_congested,
829 static int __init raid0_init (void)
831 return register_md_personality (&raid0_personality);
834 static void raid0_exit (void)
836 unregister_md_personality (&raid0_personality);
839 module_init(raid0_init);
840 module_exit(raid0_exit);
841 MODULE_LICENSE("GPL");
842 MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
843 MODULE_ALIAS("md-personality-2"); /* RAID0 */
844 MODULE_ALIAS("md-raid0");
845 MODULE_ALIAS("md-level-0");