An attempt to freeze a filesystem that does not support such operation is reported as EOPNOTSUPP to user. Running unfreeze to the same filesystem returns EINVAL. Later is a little misleading, users can mix that message with return value from unfreezing when filesystem is not frozen. Signed-off-by: Sami Kerola <kerolasa@xxxxxx> --- fs/ioctl.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/ioctl.c b/fs/ioctl.c index cb9b02940805..1d6372ef4008 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -566,6 +566,10 @@ static int ioctl_fsthaw(struct file *filp) if (!capable(CAP_SYS_ADMIN)) return -EPERM; + /* If filesystem doesn't support thaw feature, return. */ + if (!sb->s_op->unfreeze_fs) + return -EOPNOTSUPP; + /* Thaw */ if (sb->s_op->thaw_super) return sb->s_op->thaw_super(sb); -- 2.11.0 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html