This is a note to let you know that I've just added the patch titled dm raid: fix panic when attempting to force a raid to sync to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dm-raid-fix-panic-when-attempting-to-force-a-raid-to-sync.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Tue Dec 12 10:32:42 CET 2017 From: Heinz Mauelshagen <heinzm@xxxxxxxxxx> Date: Thu, 2 Nov 2017 19:58:28 +0100 Subject: dm raid: fix panic when attempting to force a raid to sync From: Heinz Mauelshagen <heinzm@xxxxxxxxxx> [ Upstream commit 233978449074ca7e45d9c959f9ec612d1b852893 ] Requesting a sync on an active raid device via a table reload (see 'sync' parameter in Documentation/device-mapper/dm-raid.txt) skips the super_load() call that defines the superblock size (rdev->sb_size) -- resulting in an oops if/when super_sync()->memset() is called. Fix by moving the initialization of the superblock start and size out of super_load() to the caller (analyse_superblocks). Signed-off-by: Heinz Mauelshagen <heinzm@xxxxxxxxxx> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/md/dm-raid.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -2143,13 +2143,6 @@ static int super_load(struct md_rdev *rd struct dm_raid_superblock *refsb; uint64_t events_sb, events_refsb; - rdev->sb_start = 0; - rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev); - if (rdev->sb_size < sizeof(*sb) || rdev->sb_size > PAGE_SIZE) { - DMERR("superblock size of a logical block is no longer valid"); - return -EINVAL; - } - r = read_disk_sb(rdev, rdev->sb_size, false); if (r) return r; @@ -2494,6 +2487,17 @@ static int analyse_superblocks(struct dm if (test_bit(Journal, &rdev->flags)) continue; + if (!rdev->meta_bdev) + continue; + + /* Set superblock offset/size for metadata device. */ + rdev->sb_start = 0; + rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev); + if (rdev->sb_size < sizeof(struct dm_raid_superblock) || rdev->sb_size > PAGE_SIZE) { + DMERR("superblock size of a logical block is no longer valid"); + return -EINVAL; + } + /* * Skipping super_load due to CTR_FLAG_SYNC will cause * the array to undergo initialization again as @@ -2506,9 +2510,6 @@ static int analyse_superblocks(struct dm if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) continue; - if (!rdev->meta_bdev) - continue; - r = super_load(rdev, freshest); switch (r) { Patches currently in stable-queue which might be from heinzm@xxxxxxxxxx are queue-4.14/dm-raid-fix-panic-when-attempting-to-force-a-raid-to-sync.patch