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authorHeinz Mauelshagen <heinzm@redhat.com>2014-10-17 13:38:50 +0200
committerMike Snitzer <snitzer@redhat.com>2014-10-21 09:32:15 -0400
commit40d43c4b4cac4c2647bf07110d7b07d35f399a84 (patch)
treec26181aac74dff7571e4c444c957ca8a8ccca9ae /drivers/md/dm-raid.c
parent9d28eb12447ee08bb5d1e8bb3195cf20e1ecd1c0 (diff)
downloadop-kernel-dev-40d43c4b4cac4c2647bf07110d7b07d35f399a84.zip
op-kernel-dev-40d43c4b4cac4c2647bf07110d7b07d35f399a84.tar.gz
dm raid: ensure superblock's size matches device's logical block size
The dm-raid superblock (struct dm_raid_superblock) is padded to 512 bytes and that size is being used to read it in from the metadata device into one preallocated page. Reading or writing this on a 512-byte sector device works fine but on a 4096-byte sector device this fails. Set the dm-raid superblock's size to the logical block size of the metadata device, because IO at that size is guaranteed too work. Also add a size check to avoid silent partial metadata loss in case the superblock should ever grow past the logical block size or PAGE_SIZE. [includes pointer math fix from Dan Carpenter] Reported-by: "Liuhua Wang" <lwang@suse.com> Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/md/dm-raid.c')
-rw-r--r--drivers/md/dm-raid.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 4857fa4..a7cb9dd 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -789,8 +789,7 @@ struct dm_raid_superblock {
__le32 layout;
__le32 stripe_sectors;
- __u8 pad[452]; /* Round struct to 512 bytes. */
- /* Always set to 0 when writing. */
+ /* Remainder of a logical block is zero-filled when writing (see super_sync()). */
} __packed;
static int read_disk_sb(struct md_rdev *rdev, int size)
@@ -827,7 +826,7 @@ static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
test_bit(Faulty, &(rs->dev[i].rdev.flags)))
failed_devices |= (1ULL << i);
- memset(sb, 0, sizeof(*sb));
+ memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
sb->magic = cpu_to_le32(DM_RAID_MAGIC);
sb->features = cpu_to_le32(0); /* No features yet */
@@ -862,7 +861,11 @@ static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
uint64_t events_sb, events_refsb;
rdev->sb_start = 0;
- rdev->sb_size = sizeof(*sb);
+ 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;
+ }
ret = read_disk_sb(rdev, rdev->sb_size);
if (ret)
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