hv: hypervvssd: call endmntent before call setmntent again

If freeze fails, vss_operate will re-enter itself to thaw. But it forgets
to call endmntent() before it recalls setmntent() again.
Signed-off-by: Vaughan Cao <vaughan.cao@oracle.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/hv/hv_vss_daemon.c

@@ -81,6 +81,7 @@ static int vss_operate(int operation)
 	char match[] = "/dev/";
 	FILE *mounts;
 	struct mntent *ent;
+	char errdir[1024] = {0};
 	unsigned int cmd;
 	int error = 0, root_seen = 0, save_errno = 0;
 
@@ -115,6 +116,8 @@ static int vss_operate(int operation)
 			goto err;
 	}
 
+	endmntent(mounts);
+
 	if (root_seen) {
 		error |= vss_do_freeze("/", cmd);
 		if (error && operation == VSS_OP_FREEZE)
@@ -124,16 +127,19 @@ static int vss_operate(int operation)
 	goto out;
 err:
 	save_errno = errno;
+	if (ent) {
+		strncpy(errdir, ent->mnt_dir, sizeof(errdir)-1);
+		endmntent(mounts);
+	}
 	vss_operate(VSS_OP_THAW);
 	/* Call syslog after we thaw all filesystems */
 	if (ent)
 		syslog(LOG_ERR, "FREEZE of %s failed; error:%d %s",
-		       ent->mnt_dir, save_errno, strerror(save_errno));
+		       errdir, save_errno, strerror(save_errno));
 	else
 		syslog(LOG_ERR, "FREEZE of / failed; error:%d %s", save_errno,
 		       strerror(save_errno));
 out:
-	endmntent(mounts);
 	return error;
 }