btrfs: prop: fix zstd compression parameter validation

We let pass zstd compression parameter even if it is not fully valid.
For example:

  $ btrfs prop set /btrfs compression zst
  $ btrfs prop get /btrfs compression
     compression=zst

zlib and lzo are fine.

Fix it by checking the correct prefix length.

Fixes: 5c1aab1dd5 ("btrfs: Add zstd support")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.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>
This commit is contained in:
Anand Jain 2019-04-02 18:07:38 +08:00 committed by David Sterba
parent f35f06c355
commit 50398fde99
1 changed files with 1 additions and 1 deletions

View File

@ -396,7 +396,7 @@ static int prop_compression_apply(struct inode *inode,
btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
} else if (!strncmp("zlib", value, 4)) {
type = BTRFS_COMPRESS_ZLIB;
} else if (!strncmp("zstd", value, len)) {
} else if (!strncmp("zstd", value, 4)) {
type = BTRFS_COMPRESS_ZSTD;
btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
} else {