Commit 3b24fbed authored by Heinz Mauelshagen's avatar Heinz Mauelshagen Committed by Luis Henriques

dm raid: ensure superblock's size matches device's logical block size

commit 40d43c4b upstream.

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: default avatar"Liuhua Wang" <lwang@suse.com>
Signed-off-by: default avatarHeinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent feb19c87
...@@ -785,8 +785,7 @@ struct dm_raid_superblock { ...@@ -785,8 +785,7 @@ struct dm_raid_superblock {
__le32 layout; __le32 layout;
__le32 stripe_sectors; __le32 stripe_sectors;
__u8 pad[452]; /* Round struct to 512 bytes. */ /* Remainder of a logical block is zero-filled when writing (see super_sync()). */
/* Always set to 0 when writing. */
} __packed; } __packed;
static int read_disk_sb(struct md_rdev *rdev, int size) static int read_disk_sb(struct md_rdev *rdev, int size)
...@@ -823,7 +822,7 @@ static void super_sync(struct mddev *mddev, struct md_rdev *rdev) ...@@ -823,7 +822,7 @@ static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
test_bit(Faulty, &(rs->dev[i].rdev.flags))) test_bit(Faulty, &(rs->dev[i].rdev.flags)))
failed_devices |= (1ULL << i); 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->magic = cpu_to_le32(DM_RAID_MAGIC);
sb->features = cpu_to_le32(0); /* No features yet */ sb->features = cpu_to_le32(0); /* No features yet */
...@@ -858,7 +857,11 @@ static int super_load(struct md_rdev *rdev, struct md_rdev *refdev) ...@@ -858,7 +857,11 @@ static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
uint64_t events_sb, events_refsb; uint64_t events_sb, events_refsb;
rdev->sb_start = 0; 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); ret = read_disk_sb(rdev, rdev->sb_size);
if (ret) if (ret)
......
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