v4.19.13 snapshot.
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
new file mode 100644
index 0000000..ac1cffd
--- /dev/null
+++ b/drivers/md/raid0.c
@@ -0,0 +1,809 @@
+/*
+ raid0.c : Multiple Devices driver for Linux
+ Copyright (C) 1994-96 Marc ZYNGIER
+ <zyngier@ufr-info-p7.ibp.fr> or
+ <maz@gloups.fdn.fr>
+ Copyright (C) 1999, 2000 Ingo Molnar, Red Hat
+
+ RAID-0 management functions.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ You should have received a copy of the GNU General Public License
+ (for example /usr/src/linux/COPYING); if not, write to the Free
+ Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <linux/blkdev.h>
+#include <linux/seq_file.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <trace/events/block.h>
+#include "md.h"
+#include "raid0.h"
+#include "raid5.h"
+
+#define UNSUPPORTED_MDDEV_FLAGS \
+ ((1L << MD_HAS_JOURNAL) | \
+ (1L << MD_JOURNAL_CLEAN) | \
+ (1L << MD_FAILFAST_SUPPORTED) |\
+ (1L << MD_HAS_PPL) | \
+ (1L << MD_HAS_MULTIPLE_PPLS))
+
+static int raid0_congested(struct mddev *mddev, int bits)
+{
+ struct r0conf *conf = mddev->private;
+ struct md_rdev **devlist = conf->devlist;
+ int raid_disks = conf->strip_zone[0].nb_dev;
+ int i, ret = 0;
+
+ for (i = 0; i < raid_disks && !ret ; i++) {
+ struct request_queue *q = bdev_get_queue(devlist[i]->bdev);
+
+ ret |= bdi_congested(q->backing_dev_info, bits);
+ }
+ return ret;
+}
+
+/*
+ * inform the user of the raid configuration
+*/
+static void dump_zones(struct mddev *mddev)
+{
+ int j, k;
+ sector_t zone_size = 0;
+ sector_t zone_start = 0;
+ char b[BDEVNAME_SIZE];
+ struct r0conf *conf = mddev->private;
+ int raid_disks = conf->strip_zone[0].nb_dev;
+ pr_debug("md: RAID0 configuration for %s - %d zone%s\n",
+ mdname(mddev),
+ conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s");
+ for (j = 0; j < conf->nr_strip_zones; j++) {
+ char line[200];
+ int len = 0;
+
+ for (k = 0; k < conf->strip_zone[j].nb_dev; k++)
+ len += snprintf(line+len, 200-len, "%s%s", k?"/":"",
+ bdevname(conf->devlist[j*raid_disks
+ + k]->bdev, b));
+ pr_debug("md: zone%d=[%s]\n", j, line);
+
+ zone_size = conf->strip_zone[j].zone_end - zone_start;
+ pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n",
+ (unsigned long long)zone_start>>1,
+ (unsigned long long)conf->strip_zone[j].dev_start>>1,
+ (unsigned long long)zone_size>>1);
+ zone_start = conf->strip_zone[j].zone_end;
+ }
+}
+
+static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
+{
+ int i, c, err;
+ sector_t curr_zone_end, sectors;
+ struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev;
+ struct strip_zone *zone;
+ int cnt;
+ char b[BDEVNAME_SIZE];
+ char b2[BDEVNAME_SIZE];
+ struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+ unsigned short blksize = 512;
+
+ *private_conf = ERR_PTR(-ENOMEM);
+ if (!conf)
+ return -ENOMEM;
+ rdev_for_each(rdev1, mddev) {
+ pr_debug("md/raid0:%s: looking at %s\n",
+ mdname(mddev),
+ bdevname(rdev1->bdev, b));
+ c = 0;
+
+ /* round size to chunk_size */
+ sectors = rdev1->sectors;
+ sector_div(sectors, mddev->chunk_sectors);
+ rdev1->sectors = sectors * mddev->chunk_sectors;
+
+ blksize = max(blksize, queue_logical_block_size(
+ rdev1->bdev->bd_disk->queue));
+
+ rdev_for_each(rdev2, mddev) {
+ pr_debug("md/raid0:%s: comparing %s(%llu)"
+ " with %s(%llu)\n",
+ mdname(mddev),
+ bdevname(rdev1->bdev,b),
+ (unsigned long long)rdev1->sectors,
+ bdevname(rdev2->bdev,b2),
+ (unsigned long long)rdev2->sectors);
+ if (rdev2 == rdev1) {
+ pr_debug("md/raid0:%s: END\n",
+ mdname(mddev));
+ break;
+ }
+ if (rdev2->sectors == rdev1->sectors) {
+ /*
+ * Not unique, don't count it as a new
+ * group
+ */
+ pr_debug("md/raid0:%s: EQUAL\n",
+ mdname(mddev));
+ c = 1;
+ break;
+ }
+ pr_debug("md/raid0:%s: NOT EQUAL\n",
+ mdname(mddev));
+ }
+ if (!c) {
+ pr_debug("md/raid0:%s: ==> UNIQUE\n",
+ mdname(mddev));
+ conf->nr_strip_zones++;
+ pr_debug("md/raid0:%s: %d zones\n",
+ mdname(mddev), conf->nr_strip_zones);
+ }
+ }
+ pr_debug("md/raid0:%s: FINAL %d zones\n",
+ mdname(mddev), conf->nr_strip_zones);
+ /*
+ * now since we have the hard sector sizes, we can make sure
+ * chunk size is a multiple of that sector size
+ */
+ if ((mddev->chunk_sectors << 9) % blksize) {
+ pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n",
+ mdname(mddev),
+ mddev->chunk_sectors << 9, blksize);
+ err = -EINVAL;
+ goto abort;
+ }
+
+ err = -ENOMEM;
+ conf->strip_zone = kcalloc(conf->nr_strip_zones,
+ sizeof(struct strip_zone),
+ GFP_KERNEL);
+ if (!conf->strip_zone)
+ goto abort;
+ conf->devlist = kzalloc(array3_size(sizeof(struct md_rdev *),
+ conf->nr_strip_zones,
+ mddev->raid_disks),
+ GFP_KERNEL);
+ if (!conf->devlist)
+ goto abort;
+
+ /* The first zone must contain all devices, so here we check that
+ * there is a proper alignment of slots to devices and find them all
+ */
+ zone = &conf->strip_zone[0];
+ cnt = 0;
+ smallest = NULL;
+ dev = conf->devlist;
+ err = -EINVAL;
+ rdev_for_each(rdev1, mddev) {
+ int j = rdev1->raid_disk;
+
+ if (mddev->level == 10) {
+ /* taking over a raid10-n2 array */
+ j /= 2;
+ rdev1->new_raid_disk = j;
+ }
+
+ if (mddev->level == 1) {
+ /* taiking over a raid1 array-
+ * we have only one active disk
+ */
+ j = 0;
+ rdev1->new_raid_disk = j;
+ }
+
+ if (j < 0) {
+ pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n",
+ mdname(mddev));
+ goto abort;
+ }
+ if (j >= mddev->raid_disks) {
+ pr_warn("md/raid0:%s: bad disk number %d - aborting!\n",
+ mdname(mddev), j);
+ goto abort;
+ }
+ if (dev[j]) {
+ pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n",
+ mdname(mddev), j);
+ goto abort;
+ }
+ dev[j] = rdev1;
+
+ if (!smallest || (rdev1->sectors < smallest->sectors))
+ smallest = rdev1;
+ cnt++;
+ }
+ if (cnt != mddev->raid_disks) {
+ pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n",
+ mdname(mddev), cnt, mddev->raid_disks);
+ goto abort;
+ }
+ zone->nb_dev = cnt;
+ zone->zone_end = smallest->sectors * cnt;
+
+ curr_zone_end = zone->zone_end;
+
+ /* now do the other zones */
+ for (i = 1; i < conf->nr_strip_zones; i++)
+ {
+ int j;
+
+ zone = conf->strip_zone + i;
+ dev = conf->devlist + i * mddev->raid_disks;
+
+ pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i);
+ zone->dev_start = smallest->sectors;
+ smallest = NULL;
+ c = 0;
+
+ for (j=0; j<cnt; j++) {
+ rdev = conf->devlist[j];
+ if (rdev->sectors <= zone->dev_start) {
+ pr_debug("md/raid0:%s: checking %s ... nope\n",
+ mdname(mddev),
+ bdevname(rdev->bdev, b));
+ continue;
+ }
+ pr_debug("md/raid0:%s: checking %s ..."
+ " contained as device %d\n",
+ mdname(mddev),
+ bdevname(rdev->bdev, b), c);
+ dev[c] = rdev;
+ c++;
+ if (!smallest || rdev->sectors < smallest->sectors) {
+ smallest = rdev;
+ pr_debug("md/raid0:%s: (%llu) is smallest!.\n",
+ mdname(mddev),
+ (unsigned long long)rdev->sectors);
+ }
+ }
+
+ zone->nb_dev = c;
+ sectors = (smallest->sectors - zone->dev_start) * c;
+ pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n",
+ mdname(mddev),
+ zone->nb_dev, (unsigned long long)sectors);
+
+ curr_zone_end += sectors;
+ zone->zone_end = curr_zone_end;
+
+ pr_debug("md/raid0:%s: current zone start: %llu\n",
+ mdname(mddev),
+ (unsigned long long)smallest->sectors);
+ }
+
+ pr_debug("md/raid0:%s: done.\n", mdname(mddev));
+ *private_conf = conf;
+
+ return 0;
+abort:
+ kfree(conf->strip_zone);
+ kfree(conf->devlist);
+ kfree(conf);
+ *private_conf = ERR_PTR(err);
+ return err;
+}
+
+/* Find the zone which holds a particular offset
+ * Update *sectorp to be an offset in that zone
+ */
+static struct strip_zone *find_zone(struct r0conf *conf,
+ sector_t *sectorp)
+{
+ int i;
+ struct strip_zone *z = conf->strip_zone;
+ sector_t sector = *sectorp;
+
+ for (i = 0; i < conf->nr_strip_zones; i++)
+ if (sector < z[i].zone_end) {
+ if (i)
+ *sectorp = sector - z[i-1].zone_end;
+ return z + i;
+ }
+ BUG();
+}
+
+/*
+ * remaps the bio to the target device. we separate two flows.
+ * power 2 flow and a general flow for the sake of performance
+*/
+static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone,
+ sector_t sector, sector_t *sector_offset)
+{
+ unsigned int sect_in_chunk;
+ sector_t chunk;
+ struct r0conf *conf = mddev->private;
+ int raid_disks = conf->strip_zone[0].nb_dev;
+ unsigned int chunk_sects = mddev->chunk_sectors;
+
+ if (is_power_of_2(chunk_sects)) {
+ int chunksect_bits = ffz(~chunk_sects);
+ /* find the sector offset inside the chunk */
+ sect_in_chunk = sector & (chunk_sects - 1);
+ sector >>= chunksect_bits;
+ /* chunk in zone */
+ chunk = *sector_offset;
+ /* quotient is the chunk in real device*/
+ sector_div(chunk, zone->nb_dev << chunksect_bits);
+ } else{
+ sect_in_chunk = sector_div(sector, chunk_sects);
+ chunk = *sector_offset;
+ sector_div(chunk, chunk_sects * zone->nb_dev);
+ }
+ /*
+ * position the bio over the real device
+ * real sector = chunk in device + starting of zone
+ * + the position in the chunk
+ */
+ *sector_offset = (chunk * chunk_sects) + sect_in_chunk;
+ return conf->devlist[(zone - conf->strip_zone)*raid_disks
+ + sector_div(sector, zone->nb_dev)];
+}
+
+static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks)
+{
+ sector_t array_sectors = 0;
+ struct md_rdev *rdev;
+
+ WARN_ONCE(sectors || raid_disks,
+ "%s does not support generic reshape\n", __func__);
+
+ rdev_for_each(rdev, mddev)
+ array_sectors += (rdev->sectors &
+ ~(sector_t)(mddev->chunk_sectors-1));
+
+ return array_sectors;
+}
+
+static void raid0_free(struct mddev *mddev, void *priv);
+
+static int raid0_run(struct mddev *mddev)
+{
+ struct r0conf *conf;
+ int ret;
+
+ if (mddev->chunk_sectors == 0) {
+ pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev));
+ return -EINVAL;
+ }
+ if (md_check_no_bitmap(mddev))
+ return -EINVAL;
+
+ /* if private is not null, we are here after takeover */
+ if (mddev->private == NULL) {
+ ret = create_strip_zones(mddev, &conf);
+ if (ret < 0)
+ return ret;
+ mddev->private = conf;
+ }
+ conf = mddev->private;
+ if (mddev->queue) {
+ struct md_rdev *rdev;
+ bool discard_supported = false;
+
+ blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
+ blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors);
+ blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors);
+ blk_queue_max_discard_sectors(mddev->queue, UINT_MAX);
+
+ blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9);
+ blk_queue_io_opt(mddev->queue,
+ (mddev->chunk_sectors << 9) * mddev->raid_disks);
+
+ rdev_for_each(rdev, mddev) {
+ disk_stack_limits(mddev->gendisk, rdev->bdev,
+ rdev->data_offset << 9);
+ if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
+ discard_supported = true;
+ }
+ if (!discard_supported)
+ blk_queue_flag_clear(QUEUE_FLAG_DISCARD, mddev->queue);
+ else
+ blk_queue_flag_set(QUEUE_FLAG_DISCARD, mddev->queue);
+ }
+
+ /* calculate array device size */
+ md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
+
+ pr_debug("md/raid0:%s: md_size is %llu sectors.\n",
+ mdname(mddev),
+ (unsigned long long)mddev->array_sectors);
+
+ if (mddev->queue) {
+ /* calculate the max read-ahead size.
+ * For read-ahead of large files to be effective, we need to
+ * readahead at least twice a whole stripe. i.e. number of devices
+ * multiplied by chunk size times 2.
+ * If an individual device has an ra_pages greater than the
+ * chunk size, then we will not drive that device as hard as it
+ * wants. We consider this a configuration error: a larger
+ * chunksize should be used in that case.
+ */
+ int stripe = mddev->raid_disks *
+ (mddev->chunk_sectors << 9) / PAGE_SIZE;
+ if (mddev->queue->backing_dev_info->ra_pages < 2* stripe)
+ mddev->queue->backing_dev_info->ra_pages = 2* stripe;
+ }
+
+ dump_zones(mddev);
+
+ ret = md_integrity_register(mddev);
+
+ return ret;
+}
+
+static void raid0_free(struct mddev *mddev, void *priv)
+{
+ struct r0conf *conf = priv;
+
+ kfree(conf->strip_zone);
+ kfree(conf->devlist);
+ kfree(conf);
+}
+
+/*
+ * Is io distribute over 1 or more chunks ?
+*/
+static inline int is_io_in_chunk_boundary(struct mddev *mddev,
+ unsigned int chunk_sects, struct bio *bio)
+{
+ if (likely(is_power_of_2(chunk_sects))) {
+ return chunk_sects >=
+ ((bio->bi_iter.bi_sector & (chunk_sects-1))
+ + bio_sectors(bio));
+ } else{
+ sector_t sector = bio->bi_iter.bi_sector;
+ return chunk_sects >= (sector_div(sector, chunk_sects)
+ + bio_sectors(bio));
+ }
+}
+
+static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
+{
+ struct r0conf *conf = mddev->private;
+ struct strip_zone *zone;
+ sector_t start = bio->bi_iter.bi_sector;
+ sector_t end;
+ unsigned int stripe_size;
+ sector_t first_stripe_index, last_stripe_index;
+ sector_t start_disk_offset;
+ unsigned int start_disk_index;
+ sector_t end_disk_offset;
+ unsigned int end_disk_index;
+ unsigned int disk;
+
+ zone = find_zone(conf, &start);
+
+ if (bio_end_sector(bio) > zone->zone_end) {
+ struct bio *split = bio_split(bio,
+ zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
+ &mddev->bio_set);
+ bio_chain(split, bio);
+ generic_make_request(bio);
+ bio = split;
+ end = zone->zone_end;
+ } else
+ end = bio_end_sector(bio);
+
+ if (zone != conf->strip_zone)
+ end = end - zone[-1].zone_end;
+
+ /* Now start and end is the offset in zone */
+ stripe_size = zone->nb_dev * mddev->chunk_sectors;
+
+ first_stripe_index = start;
+ sector_div(first_stripe_index, stripe_size);
+ last_stripe_index = end;
+ sector_div(last_stripe_index, stripe_size);
+
+ start_disk_index = (int)(start - first_stripe_index * stripe_size) /
+ mddev->chunk_sectors;
+ start_disk_offset = ((int)(start - first_stripe_index * stripe_size) %
+ mddev->chunk_sectors) +
+ first_stripe_index * mddev->chunk_sectors;
+ end_disk_index = (int)(end - last_stripe_index * stripe_size) /
+ mddev->chunk_sectors;
+ end_disk_offset = ((int)(end - last_stripe_index * stripe_size) %
+ mddev->chunk_sectors) +
+ last_stripe_index * mddev->chunk_sectors;
+
+ for (disk = 0; disk < zone->nb_dev; disk++) {
+ sector_t dev_start, dev_end;
+ struct bio *discard_bio = NULL;
+ struct md_rdev *rdev;
+
+ if (disk < start_disk_index)
+ dev_start = (first_stripe_index + 1) *
+ mddev->chunk_sectors;
+ else if (disk > start_disk_index)
+ dev_start = first_stripe_index * mddev->chunk_sectors;
+ else
+ dev_start = start_disk_offset;
+
+ if (disk < end_disk_index)
+ dev_end = (last_stripe_index + 1) * mddev->chunk_sectors;
+ else if (disk > end_disk_index)
+ dev_end = last_stripe_index * mddev->chunk_sectors;
+ else
+ dev_end = end_disk_offset;
+
+ if (dev_end <= dev_start)
+ continue;
+
+ rdev = conf->devlist[(zone - conf->strip_zone) *
+ conf->strip_zone[0].nb_dev + disk];
+ if (__blkdev_issue_discard(rdev->bdev,
+ dev_start + zone->dev_start + rdev->data_offset,
+ dev_end - dev_start, GFP_NOIO, 0, &discard_bio) ||
+ !discard_bio)
+ continue;
+ bio_chain(discard_bio, bio);
+ bio_clone_blkcg_association(discard_bio, bio);
+ if (mddev->gendisk)
+ trace_block_bio_remap(bdev_get_queue(rdev->bdev),
+ discard_bio, disk_devt(mddev->gendisk),
+ bio->bi_iter.bi_sector);
+ generic_make_request(discard_bio);
+ }
+ bio_endio(bio);
+}
+
+static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
+{
+ struct strip_zone *zone;
+ struct md_rdev *tmp_dev;
+ sector_t bio_sector;
+ sector_t sector;
+ unsigned chunk_sects;
+ unsigned sectors;
+
+ if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {
+ md_flush_request(mddev, bio);
+ return true;
+ }
+
+ if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
+ raid0_handle_discard(mddev, bio);
+ return true;
+ }
+
+ bio_sector = bio->bi_iter.bi_sector;
+ sector = bio_sector;
+ chunk_sects = mddev->chunk_sectors;
+
+ sectors = chunk_sects -
+ (likely(is_power_of_2(chunk_sects))
+ ? (sector & (chunk_sects-1))
+ : sector_div(sector, chunk_sects));
+
+ /* Restore due to sector_div */
+ sector = bio_sector;
+
+ if (sectors < bio_sectors(bio)) {
+ struct bio *split = bio_split(bio, sectors, GFP_NOIO,
+ &mddev->bio_set);
+ bio_chain(split, bio);
+ generic_make_request(bio);
+ bio = split;
+ }
+
+ zone = find_zone(mddev->private, §or);
+ tmp_dev = map_sector(mddev, zone, sector, §or);
+ bio_set_dev(bio, tmp_dev->bdev);
+ bio->bi_iter.bi_sector = sector + zone->dev_start +
+ tmp_dev->data_offset;
+
+ if (mddev->gendisk)
+ trace_block_bio_remap(bio->bi_disk->queue, bio,
+ disk_devt(mddev->gendisk), bio_sector);
+ mddev_check_writesame(mddev, bio);
+ mddev_check_write_zeroes(mddev, bio);
+ generic_make_request(bio);
+ return true;
+}
+
+static void raid0_status(struct seq_file *seq, struct mddev *mddev)
+{
+ seq_printf(seq, " %dk chunks", mddev->chunk_sectors / 2);
+ return;
+}
+
+static void *raid0_takeover_raid45(struct mddev *mddev)
+{
+ struct md_rdev *rdev;
+ struct r0conf *priv_conf;
+
+ if (mddev->degraded != 1) {
+ pr_warn("md/raid0:%s: raid5 must be degraded! Degraded disks: %d\n",
+ mdname(mddev),
+ mddev->degraded);
+ return ERR_PTR(-EINVAL);
+ }
+
+ rdev_for_each(rdev, mddev) {
+ /* check slot number for a disk */
+ if (rdev->raid_disk == mddev->raid_disks-1) {
+ pr_warn("md/raid0:%s: raid5 must have missing parity disk!\n",
+ mdname(mddev));
+ return ERR_PTR(-EINVAL);
+ }
+ rdev->sectors = mddev->dev_sectors;
+ }
+
+ /* Set new parameters */
+ mddev->new_level = 0;
+ mddev->new_layout = 0;
+ mddev->new_chunk_sectors = mddev->chunk_sectors;
+ mddev->raid_disks--;
+ mddev->delta_disks = -1;
+ /* make sure it will be not marked as dirty */
+ mddev->recovery_cp = MaxSector;
+ mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
+
+ create_strip_zones(mddev, &priv_conf);
+
+ return priv_conf;
+}
+
+static void *raid0_takeover_raid10(struct mddev *mddev)
+{
+ struct r0conf *priv_conf;
+
+ /* Check layout:
+ * - far_copies must be 1
+ * - near_copies must be 2
+ * - disks number must be even
+ * - all mirrors must be already degraded
+ */
+ if (mddev->layout != ((1 << 8) + 2)) {
+ pr_warn("md/raid0:%s:: Raid0 cannot takeover layout: 0x%x\n",
+ mdname(mddev),
+ mddev->layout);
+ return ERR_PTR(-EINVAL);
+ }
+ if (mddev->raid_disks & 1) {
+ pr_warn("md/raid0:%s: Raid0 cannot takeover Raid10 with odd disk number.\n",
+ mdname(mddev));
+ return ERR_PTR(-EINVAL);
+ }
+ if (mddev->degraded != (mddev->raid_disks>>1)) {
+ pr_warn("md/raid0:%s: All mirrors must be already degraded!\n",
+ mdname(mddev));
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* Set new parameters */
+ mddev->new_level = 0;
+ mddev->new_layout = 0;
+ mddev->new_chunk_sectors = mddev->chunk_sectors;
+ mddev->delta_disks = - mddev->raid_disks / 2;
+ mddev->raid_disks += mddev->delta_disks;
+ mddev->degraded = 0;
+ /* make sure it will be not marked as dirty */
+ mddev->recovery_cp = MaxSector;
+ mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
+
+ create_strip_zones(mddev, &priv_conf);
+ return priv_conf;
+}
+
+static void *raid0_takeover_raid1(struct mddev *mddev)
+{
+ struct r0conf *priv_conf;
+ int chunksect;
+
+ /* Check layout:
+ * - (N - 1) mirror drives must be already faulty
+ */
+ if ((mddev->raid_disks - 1) != mddev->degraded) {
+ pr_err("md/raid0:%s: (N - 1) mirrors drives must be already faulty!\n",
+ mdname(mddev));
+ return ERR_PTR(-EINVAL);
+ }
+
+ /*
+ * a raid1 doesn't have the notion of chunk size, so
+ * figure out the largest suitable size we can use.
+ */
+ chunksect = 64 * 2; /* 64K by default */
+
+ /* The array must be an exact multiple of chunksize */
+ while (chunksect && (mddev->array_sectors & (chunksect - 1)))
+ chunksect >>= 1;
+
+ if ((chunksect << 9) < PAGE_SIZE)
+ /* array size does not allow a suitable chunk size */
+ return ERR_PTR(-EINVAL);
+
+ /* Set new parameters */
+ mddev->new_level = 0;
+ mddev->new_layout = 0;
+ mddev->new_chunk_sectors = chunksect;
+ mddev->chunk_sectors = chunksect;
+ mddev->delta_disks = 1 - mddev->raid_disks;
+ mddev->raid_disks = 1;
+ /* make sure it will be not marked as dirty */
+ mddev->recovery_cp = MaxSector;
+ mddev_clear_unsupported_flags(mddev, UNSUPPORTED_MDDEV_FLAGS);
+
+ create_strip_zones(mddev, &priv_conf);
+ return priv_conf;
+}
+
+static void *raid0_takeover(struct mddev *mddev)
+{
+ /* raid0 can take over:
+ * raid4 - if all data disks are active.
+ * raid5 - providing it is Raid4 layout and one disk is faulty
+ * raid10 - assuming we have all necessary active disks
+ * raid1 - with (N -1) mirror drives faulty
+ */
+
+ if (mddev->bitmap) {
+ pr_warn("md/raid0: %s: cannot takeover array with bitmap\n",
+ mdname(mddev));
+ return ERR_PTR(-EBUSY);
+ }
+ if (mddev->level == 4)
+ return raid0_takeover_raid45(mddev);
+
+ if (mddev->level == 5) {
+ if (mddev->layout == ALGORITHM_PARITY_N)
+ return raid0_takeover_raid45(mddev);
+
+ pr_warn("md/raid0:%s: Raid can only takeover Raid5 with layout: %d\n",
+ mdname(mddev), ALGORITHM_PARITY_N);
+ }
+
+ if (mddev->level == 10)
+ return raid0_takeover_raid10(mddev);
+
+ if (mddev->level == 1)
+ return raid0_takeover_raid1(mddev);
+
+ pr_warn("Takeover from raid%i to raid0 not supported\n",
+ mddev->level);
+
+ return ERR_PTR(-EINVAL);
+}
+
+static void raid0_quiesce(struct mddev *mddev, int quiesce)
+{
+}
+
+static struct md_personality raid0_personality=
+{
+ .name = "raid0",
+ .level = 0,
+ .owner = THIS_MODULE,
+ .make_request = raid0_make_request,
+ .run = raid0_run,
+ .free = raid0_free,
+ .status = raid0_status,
+ .size = raid0_size,
+ .takeover = raid0_takeover,
+ .quiesce = raid0_quiesce,
+ .congested = raid0_congested,
+};
+
+static int __init raid0_init (void)
+{
+ return register_md_personality (&raid0_personality);
+}
+
+static void raid0_exit (void)
+{
+ unregister_md_personality (&raid0_personality);
+}
+
+module_init(raid0_init);
+module_exit(raid0_exit);
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("RAID0 (striping) personality for MD");
+MODULE_ALIAS("md-personality-2"); /* RAID0 */
+MODULE_ALIAS("md-raid0");
+MODULE_ALIAS("md-level-0");