dm raid: fix activation of existing raid4/10 devices

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().

Cc: stable@vger.kernel.org # 4.8
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/Documentation/device-mapper/dm-raid.txt b/Documentation/device-mapper/dm-raid.txt
index e5b6497..c75b64a 100644 (file)
--- 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

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 2a39700..6d53810 100644 (file)
--- 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 raid_set *rs, struct md_rdev *rdev)
                /*
                 * 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 raid_set *rs, struct md_rdev *rdev)
                              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 raid_set *rs, struct md_rdev *rdev)
                        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 *ti)
 
 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,