[PATCH] xfs: bulletfproof xfs_qm_scall_trunc_qfiles()

[Eric Sandeen]

Coverity noticed that if we sent junk into
xfs_qm_scall_trunc_qfiles(), we could get back an
uninitialized error value.  So sanitize the flags we
will accept, and initialize error anyway for good measure.

(This bug may have been introduced via c61a9e39).

Should resolve Coverity CID 1163872.

Signed-off-by: Eric Sandeen <sandeen at redhat.com>
---

diff --git a/fs/xfs/xfs_qm_syscalls.c b/fs/xfs/xfs_qm_syscalls.c
index 3daf5ea..17ec2c2 100644
--- a/fs/xfs/xfs_qm_syscalls.c
+++ b/fs/xfs/xfs_qm_syscalls.c
@@ -278,9 +279,10 @@ xfs_qm_scall_trunc_qfiles(
 	xfs_mount_t	*mp,
 	uint		flags)
 {
-	int		error;
+	int		error = EINVAL;
 
-	if (!xfs_sb_version_hasquota(&mp->m_sb) || flags == 0) {
+	if (!xfs_sb_version_hasquota(&mp->m_sb) || flags == 0 ||
+	    (flags & ~XFS_DQ_ALLTYPES)) {
 		xfs_debug(mp, "%s: flags=%x m_qflags=%x",
 			__func__, flags, mp->m_qflags);
 		return XFS_ERROR(EINVAL);