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| author |   Anand Jain <anand.jain@oracle.com> | 2020-09-30 21:09:52 +0800 |
|---|---|---|
| committer |   David Sterba <dsterba@suse.com> | 2020-10-07 12:17:59 +0200 |
| commit | 96c2e067ed3e3e004580a643c76f58729206b829 (patch) | |
| tree | b5a7bb05bc4a213bf74aef1d33b4e00b2041e472 /fs/btrfs/disk-io.c | |
| parent | btrfs: cleanup cow block on error (diff) | |
| download | wireguard-linux-96c2e067ed3e3e004580a643c76f58729206b829.tar.xz wireguard-linux-96c2e067ed3e3e004580a643c76f58729206b829.zip | |
btrfs: skip devices without magic signature when mounting
Many things can happen after the device is scanned and before the device
is mounted. One such thing is losing the BTRFS_MAGIC on the device.
If it happens we still won't free that device from the memory and cause
the userland confusion.
For example: As the BTRFS_IOC_DEV_INFO still carries the device path
which does not have the BTRFS_MAGIC, 'btrfs fi show' still lists
device which does not belong to the filesystem anymore:
$ mkfs.btrfs -fq -draid1 -mraid1 /dev/sda /dev/sdb
$ wipefs -a /dev/sdb
# /dev/sdb does not contain magic signature
$ mount -o degraded /dev/sda /btrfs
$ btrfs fi show -m
Label: none uuid: 470ec6fb-646b-4464-b3cb-df1b26c527bd
Total devices 2 FS bytes used 128.00KiB
devid 1 size 3.00GiB used 571.19MiB path /dev/sda
devid 2 size 3.00GiB used 571.19MiB path /dev/sdb
We need to distinguish the missing signature and invalid superblock, so
add a specific error code ENODATA for that. This also fixes failure of
fstest btrfs/198.
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/disk-io.c')
| -rw-r--r-- | fs/btrfs/disk-io.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 3d39f5d47ad3..764001609a15 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3424,8 +3424,12 @@ struct btrfs_super_block *btrfs_read_dev_one_super(struct block_device *bdev, return ERR_CAST(page); super = page_address(page); - if (btrfs_super_bytenr(super) != bytenr || - btrfs_super_magic(super) != BTRFS_MAGIC) { + if (btrfs_super_magic(super) != BTRFS_MAGIC) { + btrfs_release_disk_super(super); + return ERR_PTR(-ENODATA); + } + + if (btrfs_super_bytenr(super) != bytenr) { btrfs_release_disk_super(super); return ERR_PTR(-EINVAL); } |