md: Add support for Raid5->Raid0 and Raid10->Raid0 takeover
Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index c2e0d1d..afddf62 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -22,6 +22,7 @@
#include <linux/seq_file.h>
#include "md.h"
#include "raid0.h"
+#include "raid5.h"
static void raid0_unplug(struct request_queue *q)
{
@@ -90,7 +91,7 @@
printk(KERN_INFO "**********************************\n\n");
}
-static int create_strip_zones(mddev_t *mddev)
+static int create_strip_zones(mddev_t *mddev, raid0_conf_t **private_conf)
{
int i, c, err;
sector_t curr_zone_end, sectors;
@@ -164,6 +165,10 @@
list_for_each_entry(rdev1, &mddev->disks, same_set) {
int j = rdev1->raid_disk;
+ if (mddev->level == 10)
+ /* taking over a raid10-n2 array */
+ j /= 2;
+
if (j < 0 || j >= mddev->raid_disks) {
printk(KERN_ERR "raid0: bad disk number %d - "
"aborting!\n", j);
@@ -264,13 +269,14 @@
(mddev->chunk_sectors << 9) * mddev->raid_disks);
printk(KERN_INFO "raid0: done.\n");
- mddev->private = conf;
+ *private_conf = conf;
+
return 0;
abort:
kfree(conf->strip_zone);
kfree(conf->devlist);
kfree(conf);
- mddev->private = NULL;
+ *private_conf = NULL;
return err;
}
@@ -321,6 +327,7 @@
static int raid0_run(mddev_t *mddev)
{
+ raid0_conf_t *conf;
int ret;
if (mddev->chunk_sectors == 0) {
@@ -332,9 +339,20 @@
blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors);
mddev->queue->queue_lock = &mddev->queue->__queue_lock;
- ret = create_strip_zones(mddev);
- if (ret < 0)
- return ret;
+ /* 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 (conf->scale_raid_disks) {
+ int i;
+ for (i=0; i < conf->strip_zone[0].nb_dev; i++)
+ conf->devlist[i]->raid_disk /= conf->scale_raid_disks;
+ /* FIXME update sysfs rd links */
+ }
/* calculate array device size */
md_set_array_sectors(mddev, raid0_size(mddev, 0, 0));
@@ -548,6 +566,99 @@
return;
}
+static void *raid0_takeover_raid5(mddev_t *mddev)
+{
+ mdk_rdev_t *rdev;
+ raid0_conf_t *priv_conf;
+
+ if (mddev->degraded != 1) {
+ printk(KERN_ERR "md: raid5 must be degraded! Degraded disks: %d\n",
+ mddev->degraded);
+ return ERR_PTR(-EINVAL);
+ }
+
+ list_for_each_entry(rdev, &mddev->disks, same_set) {
+ /* check slot number for a disk */
+ if (rdev->raid_disk == mddev->raid_disks-1) {
+ printk(KERN_ERR "md: raid5 must have missing parity disk!\n");
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ /* Set new parameters */
+ mddev->new_level = 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;
+
+ create_strip_zones(mddev, &priv_conf);
+ return priv_conf;
+}
+
+static void *raid0_takeover_raid10(mddev_t *mddev)
+{
+ raid0_conf_t *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)) {
+ printk(KERN_ERR "md: Raid0 cannot takover layout: %x\n",
+ mddev->layout);
+ return ERR_PTR(-EINVAL);
+ }
+ if (mddev->raid_disks & 1) {
+ printk(KERN_ERR "md: Raid0 cannot takover Raid10 with odd disk number.\n");
+ return ERR_PTR(-EINVAL);
+ }
+ if (mddev->degraded != (mddev->raid_disks>>1)) {
+ printk(KERN_ERR "md: All mirrors must be already degraded!\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* Set new parameters */
+ mddev->new_level = 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;
+
+ create_strip_zones(mddev, &priv_conf);
+ priv_conf->scale_raid_disks = 2;
+ return priv_conf;
+}
+
+static void *raid0_takeover(mddev_t *mddev)
+{
+ /* raid0 can take over:
+ * raid5 - providing it is Raid4 layout and one disk is faulty
+ * raid10 - assuming we have all necessary active disks
+ */
+ if (mddev->level == 5) {
+ if (mddev->layout == ALGORITHM_PARITY_N)
+ return raid0_takeover_raid5(mddev);
+
+ printk(KERN_ERR "md: Raid can only takeover Raid5 with layout: %d\n",
+ ALGORITHM_PARITY_N);
+ }
+
+ if (mddev->level == 10)
+ return raid0_takeover_raid10(mddev);
+
+ return ERR_PTR(-EINVAL);
+}
+
+static void raid0_quiesce(mddev_t *mddev, int state)
+{
+}
+
static struct mdk_personality raid0_personality=
{
.name = "raid0",
@@ -558,6 +669,8 @@
.stop = raid0_stop,
.status = raid0_status,
.size = raid0_size,
+ .takeover = raid0_takeover,
+ .quiesce = raid0_quiesce,
};
static int __init raid0_init (void)