From: Anand Jain anand.jain@oracle.com
commit 272e5326c7837697882ce3162029ba893059b616 upstream.
The compression property resets to NULL, instead of the old value if we fail to set the new compression parameter.
$ btrfs prop get /btrfs compression compression=lzo $ btrfs prop set /btrfs compression zli ERROR: failed to set compression for /btrfs: Invalid argument $ btrfs prop get /btrfs compression
This is because the compression property ->validate() is successful for 'zli' as the strncmp() used the length passed from the userspace.
Fix it by using the expected string length in strncmp().
Fixes: 63541927c8d1 ("Btrfs: add support for inode properties") 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 | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/fs/btrfs/props.c +++ b/fs/btrfs/props.c @@ -366,11 +366,11 @@ int btrfs_subvol_inherit_props(struct bt
static int prop_compression_validate(const char *value, size_t len) { - if (!strncmp("lzo", value, len)) + if (!strncmp("lzo", value, 3)) return 0; - else if (!strncmp("zlib", value, len)) + else if (!strncmp("zlib", value, 4)) return 0; - else if (!strncmp("zstd", value, len)) + else if (!strncmp("zstd", value, 4)) return 0;
return -EINVAL;