[PATCH 4.8 087/138] dm raid: fix activation of existing raid4/10 devices

From: Greg Kroah-Hartman
Date: Wed Nov 09 2016 - 06:24:21 EST


4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Heinz Mauelshagen <heinzm@xxxxxxxxxx>

commit b052b07c39d593c9954a84d5bbe1563999483f38 upstream.

dm-raid 1.9.0 fails to activate existing RAID4/10 devices that have the
old superblock format (which does not have takeover/reshaping support
that was added via commit 33e53f06850f).

Fix validation path for old superblocks by reverting to the old raid4
layout and basing checks on mddev->new_{level,layout,...} members in
super_init_validation().

Signed-off-by: Heinz Mauelshagen <heinzm@xxxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
Documentation/device-mapper/dm-raid.txt | 1 +
drivers/md/dm-raid.c | 12 +++++++-----
2 files changed, 8 insertions(+), 5 deletions(-)

--- a/Documentation/device-mapper/dm-raid.txt
+++ b/Documentation/device-mapper/dm-raid.txt
@@ -309,3 +309,4 @@ Version History
with a reshape in progress.
1.9.0 Add support for RAID level takeover/reshape/region size
and set size reduction.
+1.9.1 Fix activation of existing RAID 4/10 mapped devices
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -266,7 +266,7 @@ static struct raid_type {
{"raid10_offset", "raid10 offset (striped mirrors)", 0, 2, 10, ALGORITHM_RAID10_OFFSET},
{"raid10_near", "raid10 near (striped mirrors)", 0, 2, 10, ALGORITHM_RAID10_NEAR},
{"raid10", "raid10 (striped mirrors)", 0, 2, 10, ALGORITHM_RAID10_DEFAULT},
- {"raid4", "raid4 (dedicated last parity disk)", 1, 2, 4, ALGORITHM_PARITY_N}, /* raid4 layout = raid5_n */
+ {"raid4", "raid4 (dedicated first parity disk)", 1, 2, 5, ALGORITHM_PARITY_0}, /* raid4 layout = raid5_0 */
{"raid5_n", "raid5 (dedicated last parity disk)", 1, 2, 5, ALGORITHM_PARITY_N},
{"raid5_ls", "raid5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
{"raid5_rs", "raid5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
@@ -2087,11 +2087,11 @@ static int super_init_validation(struct
/*
* No takeover/reshaping, because we don't have the extended v1.9.0 metadata
*/
- if (le32_to_cpu(sb->level) != mddev->level) {
+ if (le32_to_cpu(sb->level) != mddev->new_level) {
DMERR("Reshaping/takeover raid sets not yet supported. (raid level/stripes/size change)");
return -EINVAL;
}
- if (le32_to_cpu(sb->layout) != mddev->layout) {
+ if (le32_to_cpu(sb->layout) != mddev->new_layout) {
DMERR("Reshaping raid sets not yet supported. (raid layout change)");
DMERR(" 0x%X vs 0x%X", le32_to_cpu(sb->layout), mddev->layout);
DMERR(" Old layout: %s w/ %d copies",
@@ -2102,7 +2102,7 @@ static int super_init_validation(struct
raid10_md_layout_to_copies(mddev->layout));
return -EINVAL;
}
- if (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors) {
+ if (le32_to_cpu(sb->stripe_sectors) != mddev->new_chunk_sectors) {
DMERR("Reshaping raid sets not yet supported. (stripe sectors change)");
return -EINVAL;
}
@@ -2115,6 +2115,8 @@ static int super_init_validation(struct
return -EINVAL;
}

+ DMINFO("Discovered old metadata format; upgrading to extended metadata format");
+
/* Table line is checked vs. authoritative superblock */
rs_set_new(rs);
}
@@ -3647,7 +3649,7 @@ static void raid_resume(struct dm_target

static struct target_type raid_target = {
.name = "raid",
- .version = {1, 9, 0},
+ .version = {1, 9, 1},
.module = THIS_MODULE,
.ctr = raid_ctr,
.dtr = raid_dtr,