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 len passed from the userland. Fix it by using the expected string length in strncmp(). Signed-off-by: Anand Jain <anand.j...@oracle.com> --- fs/btrfs/props.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c index 3cc007e3c7f8..72a06c4d3c70 100644 --- a/fs/btrfs/props.c +++ b/fs/btrfs/props.c @@ -275,11 +275,11 @@ static int prop_compression_validate(const char *value, size_t len) if (!value) return 0; - 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; -- 1.8.3.1