From: Anand Jain anand.jain@oracle.com
commit 50398fde997f6be8faebdb5f38e9c9c467370f51 upstream.
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: 5c1aab1dd544 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/props.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/btrfs/props.c +++ b/fs/btrfs/props.c @@ -396,7 +396,7 @@ static int prop_compression_apply(struct 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 {