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 = kzalloc(sizeof(struct strip_zone)*
167 conf->nr_strip_zones, GFP_KERNEL);
168 if (!conf->strip_zone)
170 conf->devlist = kzalloc(sizeof(struct md_rdev*)*
171 conf->nr_strip_zones*mddev->raid_disks,
176 /* The first zone must contain all devices, so here we check that
177 * there is a proper alignment of slots to devices and find them all
179 zone = &conf->strip_zone[0];
184 rdev_for_each(rdev1, mddev) {
185 int j = rdev1->raid_disk;
187 if (mddev->level == 10) {
188 /* taking over a raid10-n2 array */
190 rdev1->new_raid_disk = j;
193 if (mddev->level == 1) {
194 /* taiking over a raid1 array-
195 * we have only one active disk
198 rdev1->new_raid_disk = j;
202 pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
206 if (j >= mddev->raid_disks) {
207 pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
212 pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
218 if (!smallest || (rdev1->sectors < smallest->sectors))
222 if (cnt != mddev->raid_disks) {
223 pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
224 mdname(mddev), cnt, mddev->raid_disks);
228 zone->zone_end = smallest->sectors * cnt;
230 curr_zone_end = zone->zone_end;
232 /* now do the other zones */
233 for (i = 1; i < conf->nr_strip_zones; i++)
237 zone = conf->strip_zone + i;
238 dev = conf->devlist + i * mddev->raid_disks;
240 pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
241 zone->dev_start = smallest->sectors;
245 for (j=0; j<cnt; j++) {
246 rdev = conf->devlist[j];
247 if (rdev->sectors <= zone->dev_start) {
248 pr_debug("md/raid0:%s: checking %s ... nope\n",
250 bdevname(rdev->bdev, b));
253 pr_debug("md/raid0:%s: checking %s ..."
254 " contained as device %d\n",
256 bdevname(rdev->bdev, b), c);
259 if (!smallest || rdev->sectors < smallest->sectors) {
261 pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
263 (unsigned long long)rdev->sectors);
268 sectors = (smallest->sectors - zone->dev_start) * c;
269 pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
271 zone->nb_dev, (unsigned long long)sectors);
273 curr_zone_end += sectors;
274 zone->zone_end = curr_zone_end;
276 pr_debug("md/raid0:%s: current zone start: %llu\n",
278 (unsigned long long)smallest->sectors);
281 if (conf->nr_strip_zones == 1 || conf->strip_zone[1].nb_dev == 1) {
282 conf->layout = RAID0_ORIG_LAYOUT;
283 } else if (mddev->layout == RAID0_ORIG_LAYOUT ||
284 mddev->layout == RAID0_ALT_MULTIZONE_LAYOUT) {
285 conf->layout = mddev->layout;
286 } else if (default_layout == RAID0_ORIG_LAYOUT ||
287 default_layout == RAID0_ALT_MULTIZONE_LAYOUT) {
288 conf->layout = default_layout;
290 pr_err("md/raid0:%s: cannot assemble multi-zone RAID0 with default_layout setting\n",
292 pr_err("md/raid0: please set raid0.default_layout to 1 or 2\n");
297 if (conf->layout == RAID0_ORIG_LAYOUT) {
298 for (i = 1; i < conf->nr_strip_zones; i++) {
299 sector_t first_sector = conf->strip_zone[i-1].zone_end;
301 sector_div(first_sector, mddev->chunk_sectors);
302 zone = conf->strip_zone + i;
303 /* disk_shift is first disk index used in the zone */
304 zone->disk_shift = sector_div(first_sector,
309 pr_debug("md/raid0:%s: done.\n", mdname(mddev));
310 *private_conf = conf;
314 kfree(conf->strip_zone);
315 kfree(conf->devlist);
317 *private_conf = ERR_PTR(err);
321 /* Find the zone which holds a particular offset
322 * Update *sectorp to be an offset in that zone
324 static struct strip_zone *find_zone(struct r0conf *conf,
328 struct strip_zone *z = conf->strip_zone;
329 sector_t sector = *sectorp;
331 for (i = 0; i < conf->nr_strip_zones; i++)
332 if (sector < z[i].zone_end) {
334 *sectorp = sector - z[i-1].zone_end;
341 * remaps the bio to the target device. we separate two flows.
342 * power 2 flow and a general flow for the sake of performance
344 static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
345 sector_t sector, sector_t *sector_offset)
347 unsigned int sect_in_chunk;
349 struct r0conf *conf = mddev->private;
350 int raid_disks = conf->strip_zone[0].nb_dev;
351 unsigned int chunk_sects = mddev->chunk_sectors;
353 if (is_power_of_2(chunk_sects)) {
354 int chunksect_bits = ffz(~chunk_sects);
355 /* find the sector offset inside the chunk */
356 sect_in_chunk = sector & (chunk_sects - 1);
357 sector >>= chunksect_bits;
359 chunk = *sector_offset;
360 /* quotient is the chunk in real device*/
361 sector_div(chunk, zone->nb_dev << chunksect_bits);
363 sect_in_chunk = sector_div(sector, chunk_sects);
364 chunk = *sector_offset;
365 sector_div(chunk, chunk_sects * zone->nb_dev);
368 * position the bio over the real device
369 * real sector = chunk in device + starting of zone
370 * + the position in the chunk
372 *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
373 return conf->devlist[(zone - conf->strip_zone)*raid_disks
374 + sector_div(sector, zone->nb_dev)];
377 static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
379 sector_t array_sectors = 0;
380 struct md_rdev *rdev;
382 WARN_ONCE(sectors || raid_disks,
383 "%s does not support generic reshape\n", __func__);
385 rdev_for_each(rdev, mddev)
386 array_sectors += (rdev->sectors &
387 ~(sector_t)(mddev->chunk_sectors-1));
389 return array_sectors;
392 static void raid0_free(struct mddev *mddev, void *priv);
394 static int raid0_run(struct mddev *mddev)
399 if (mddev->chunk_sectors == 0) {
400 pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
403 if (md_check_no_bitmap(mddev))
406 /* if private is not null, we are here after takeover */
407 if (mddev->private == NULL) {
408 ret = create_strip_zones(mddev, &conf);
411 mddev->private = conf;
413 conf = mddev->private;
415 struct md_rdev *rdev;
416 bool discard_supported = false;
418 blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
419 blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
420 blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
421 blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
423 blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
424 blk_queue_io_opt(mddev->queue,
425 (mddev->chunk_sectors << 9) * mddev->raid_disks);
427 rdev_for_each(rdev, mddev) {
428 disk_stack_limits(mddev->gendisk, rdev->bdev,
429 rdev->data_offset << 9);
430 if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
431 discard_supported = true;
433 if (!discard_supported)
434 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
436 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
439 /* calculate array device size */
440 md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
442 pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
444 (unsigned long long)mddev->array_sectors);
447 /* calculate the max read-ahead size.
448 * For read-ahead of large files to be effective, we need to
449 * readahead at least twice a whole stripe. i.e. number of devices
450 * multiplied by chunk size times 2.
451 * If an individual device has an ra_pages greater than the
452 * chunk size, then we will not drive that device as hard as it
453 * wants. We consider this a configuration error: a larger
454 * chunksize should be used in that case.
456 int stripe = mddev->raid_disks *
457 (mddev->chunk_sectors << 9) / PAGE_SIZE;
458 if (mddev->queue->backing_dev_info->ra_pages < 2* stripe)
459 mddev->queue->backing_dev_info->ra_pages = 2* stripe;
464 ret = md_integrity_register(mddev);
469 static void raid0_free(struct mddev *mddev, void *priv)
471 struct r0conf *conf = priv;
473 kfree(conf->strip_zone);
474 kfree(conf->devlist);
479 * Is io distribute over 1 or more chunks ?
481 static inline int is_io_in_chunk_boundary(struct mddev *mddev,
482 unsigned int chunk_sects, struct bio *bio)
484 if (likely(is_power_of_2(chunk_sects))) {
485 return chunk_sects >=
486 ((bio->bi_iter.bi_sector & (chunk_sects-1))
489 sector_t sector = bio->bi_iter.bi_sector;
490 return chunk_sects >= (sector_div(sector, chunk_sects)
496 * Convert disk_index to the disk order in which it is read/written.
497 * For example, if we have 4 disks, they are numbered 0,1,2,3. If we
498 * write the disks starting at disk 3, then the read/write order would
499 * be disk 3, then 0, then 1, and then disk 2 and we want map_disk_shift()
500 * to map the disks as follows 0,1,2,3 => 1,2,3,0. So disk 0 would map
501 * to 1, 1 to 2, 2 to 3, and 3 to 0. That way we can compare disks in
502 * that 'output' space to understand the read/write disk ordering.
504 static int map_disk_shift(int disk_index, int num_disks, int disk_shift)
506 return ((disk_index + num_disks - disk_shift) % num_disks);
509 static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
511 struct r0conf *conf = mddev->private;
512 struct strip_zone *zone;
513 sector_t start = bio->bi_iter.bi_sector;
515 unsigned int stripe_size;
516 sector_t first_stripe_index, last_stripe_index;
517 sector_t start_disk_offset;
518 unsigned int start_disk_index;
519 sector_t end_disk_offset;
520 unsigned int end_disk_index;
522 sector_t orig_start, orig_end;
525 zone = find_zone(conf, &start);
527 if (bio_end_sector(bio) > zone->zone_end) {
528 struct bio *split = bio_split(bio,
529 zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
531 bio_chain(split, bio);
532 generic_make_request(bio);
534 end = zone->zone_end;
536 end = bio_end_sector(bio);
539 if (zone != conf->strip_zone)
540 end = end - zone[-1].zone_end;
542 /* Now start and end is the offset in zone */
543 stripe_size = zone->nb_dev * mddev->chunk_sectors;
545 first_stripe_index = start;
546 sector_div(first_stripe_index, stripe_size);
547 last_stripe_index = end;
548 sector_div(last_stripe_index, stripe_size);
550 /* In the first zone the original and alternate layouts are the same */
551 if ((conf->layout == RAID0_ORIG_LAYOUT) && (zone != conf->strip_zone)) {
552 sector_div(orig_start, mddev->chunk_sectors);
553 start_disk_index = sector_div(orig_start, zone->nb_dev);
554 start_disk_index = map_disk_shift(start_disk_index,
557 sector_div(orig_end, mddev->chunk_sectors);
558 end_disk_index = sector_div(orig_end, zone->nb_dev);
559 end_disk_index = map_disk_shift(end_disk_index,
560 zone->nb_dev, zone->disk_shift);
562 start_disk_index = (int)(start - first_stripe_index * stripe_size) /
563 mddev->chunk_sectors;
564 end_disk_index = (int)(end - last_stripe_index * stripe_size) /
565 mddev->chunk_sectors;
567 start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
568 mddev->chunk_sectors) +
569 first_stripe_index * mddev->chunk_sectors;
570 end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
571 mddev->chunk_sectors) +
572 last_stripe_index * mddev->chunk_sectors;
574 for (disk = 0; disk < zone->nb_dev; disk++) {
575 sector_t dev_start, dev_end;
576 struct bio *discard_bio = NULL;
577 struct md_rdev *rdev;
580 compare_disk = map_disk_shift(disk, zone->nb_dev,
583 if (compare_disk < start_disk_index)
584 dev_start = (first_stripe_index + 1) *
585 mddev->chunk_sectors;
586 else if (compare_disk > start_disk_index)
587 dev_start = first_stripe_index * mddev->chunk_sectors;
589 dev_start = start_disk_offset;
591 if (compare_disk < end_disk_index)
592 dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
593 else if (compare_disk > end_disk_index)
594 dev_end = last_stripe_index * mddev->chunk_sectors;
596 dev_end = end_disk_offset;
598 if (dev_end <= dev_start)
601 rdev = conf->devlist[(zone - conf->strip_zone) *
602 conf->strip_zone[0].nb_dev + disk];
603 if (__blkdev_issue_discard(rdev->bdev,
604 dev_start + zone->dev_start + rdev->data_offset,
605 dev_end - dev_start, GFP_NOIO, 0, &discard_bio) ||
608 bio_chain(discard_bio, bio);
609 bio_clone_blkcg_association(discard_bio, bio);
611 trace_block_bio_remap(bdev_get_queue(rdev->bdev),
612 discard_bio, disk_devt(mddev->gendisk),
613 bio->bi_iter.bi_sector);
614 generic_make_request(discard_bio);
619 static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
621 struct r0conf *conf = mddev->private;
622 struct strip_zone *zone;
623 struct md_rdev *tmp_dev;
626 sector_t orig_sector;
627 unsigned chunk_sects;
630 if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
631 md_flush_request(mddev, bio);
635 if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
636 raid0_handle_discard(mddev, bio);
640 bio_sector = bio->bi_iter.bi_sector;
642 chunk_sects = mddev->chunk_sectors;
644 sectors = chunk_sects -
645 (likely(is_power_of_2(chunk_sects))
646 ? (sector & (chunk_sects-1))
647 : sector_div(sector, chunk_sects));
649 /* Restore due to sector_div */
652 if (sectors < bio_sectors(bio)) {
653 struct bio *split = bio_split(bio, sectors, GFP_NOIO, mddev->bio_set);
654 bio_chain(split, bio);
655 generic_make_request(bio);
659 orig_sector = sector;
660 zone = find_zone(mddev->private, §or);
661 switch (conf->layout) {
662 case RAID0_ORIG_LAYOUT:
663 tmp_dev = map_sector(mddev, zone, orig_sector, §or);
665 case RAID0_ALT_MULTIZONE_LAYOUT:
666 tmp_dev = map_sector(mddev, zone, sector, §or);
669 WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
674 bio_set_dev(bio, tmp_dev->bdev);
675 bio->bi_iter.bi_sector = sector + zone->dev_start +
676 tmp_dev->data_offset;
679 trace_block_bio_remap(bio->bi_disk->queue, bio,
680 disk_devt(mddev->gendisk), bio_sector);
681 mddev_check_writesame(mddev, bio);
682 mddev_check_write_zeroes(mddev, bio);
683 generic_make_request(bio);
687 static void raid0_status(struct seq_file *seq, struct mddev *mddev)
689 seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
693 static void *raid0_takeover_raid45(struct mddev *mddev)
695 struct md_rdev *rdev;
696 struct r0conf *priv_conf;
698 if (mddev->degraded != 1) {
699 pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
702 return ERR_PTR(-EINVAL);
705 rdev_for_each(rdev, mddev) {
706 /* check slot number for a disk */
707 if (rdev->raid_disk == mddev->raid_disks-1) {
708 pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
710 return ERR_PTR(-EINVAL);
712 rdev->sectors = mddev->dev_sectors;
715 /* Set new parameters */
716 mddev->new_level = 0;
717 mddev->new_layout = 0;
718 mddev->new_chunk_sectors = mddev->chunk_sectors;
720 mddev->delta_disks = -1;
721 /* make sure it will be not marked as dirty */
722 mddev->recovery_cp = MaxSector;
723 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
725 create_strip_zones(mddev, &priv_conf);
730 static void *raid0_takeover_raid10(struct mddev *mddev)
732 struct r0conf *priv_conf;
735 * - far_copies must be 1
736 * - near_copies must be 2
737 * - disks number must be even
738 * - all mirrors must be already degraded
740 if (mddev->layout != ((1 << 8) + 2)) {
741 pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
744 return ERR_PTR(-EINVAL);
746 if (mddev->raid_disks & 1) {
747 pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
749 return ERR_PTR(-EINVAL);
751 if (mddev->degraded != (mddev->raid_disks>>1)) {
752 pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
754 return ERR_PTR(-EINVAL);
757 /* Set new parameters */
758 mddev->new_level = 0;
759 mddev->new_layout = 0;
760 mddev->new_chunk_sectors = mddev->chunk_sectors;
761 mddev->delta_disks = - mddev->raid_disks / 2;
762 mddev->raid_disks += mddev->delta_disks;
764 /* make sure it will be not marked as dirty */
765 mddev->recovery_cp = MaxSector;
766 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
768 create_strip_zones(mddev, &priv_conf);
772 static void *raid0_takeover_raid1(struct mddev *mddev)
774 struct r0conf *priv_conf;
778 * - (N - 1) mirror drives must be already faulty
780 if ((mddev->raid_disks - 1) != mddev->degraded) {
781 pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
783 return ERR_PTR(-EINVAL);
787 * a raid1 doesn't have the notion of chunk size, so
788 * figure out the largest suitable size we can use.
790 chunksect = 64 * 2; /* 64K by default */
792 /* The array must be an exact multiple of chunksize */
793 while (chunksect && (mddev->array_sectors & (chunksect - 1)))
796 if ((chunksect << 9) < PAGE_SIZE)
797 /* array size does not allow a suitable chunk size */
798 return ERR_PTR(-EINVAL);
800 /* Set new parameters */
801 mddev->new_level = 0;
802 mddev->new_layout = 0;
803 mddev->new_chunk_sectors = chunksect;
804 mddev->chunk_sectors = chunksect;
805 mddev->delta_disks = 1 - mddev->raid_disks;
806 mddev->raid_disks = 1;
807 /* make sure it will be not marked as dirty */
808 mddev->recovery_cp = MaxSector;
809 mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
811 create_strip_zones(mddev, &priv_conf);
815 static void *raid0_takeover(struct mddev *mddev)
817 /* raid0 can take over:
818 * raid4 - if all data disks are active.
819 * raid5 - providing it is Raid4 layout and one disk is faulty
820 * raid10 - assuming we have all necessary active disks
821 * raid1 - with (N -1) mirror drives faulty
825 pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
827 return ERR_PTR(-EBUSY);
829 if (mddev->level == 4)
830 return raid0_takeover_raid45(mddev);
832 if (mddev->level == 5) {
833 if (mddev->layout == ALGORITHM_PARITY_N)
834 return raid0_takeover_raid45(mddev);
836 pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
837 mdname(mddev), ALGORITHM_PARITY_N);
840 if (mddev->level == 10)
841 return raid0_takeover_raid10(mddev);
843 if (mddev->level == 1)
844 return raid0_takeover_raid1(mddev);
846 pr_warn("Takeover from raid%i to raid0 not supported\n",
849 return ERR_PTR(-EINVAL);
852 static void raid0_quiesce(struct mddev *mddev, int quiesce)
856 static struct md_personality raid0_personality=
860 .owner = THIS_MODULE,
861 .make_request = raid0_make_request,
864 .status = raid0_status,
866 .takeover = raid0_takeover,
867 .quiesce = raid0_quiesce,
868 .congested = raid0_congested,
871 static int __init raid0_init (void)
873 return register_md_personality (&raid0_personality);
876 static void raid0_exit (void)
878 unregister_md_personality (&raid0_personality);
881 module_init(raid0_init);
882 module_exit(raid0_exit);
883 MODULE_LICENSE("GPL");
884 MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
885 MODULE_ALIAS("md-personality-2"); /* RAID0 */
886 MODULE_ALIAS("md-raid0");
887 MODULE_ALIAS("md-level-0");