[libvirt] [PATCH] lxc_container.c: avoid a leak on error paths

[Jim Meyering]

This started with a dead-store report:

    File:		lxc_container.c
    Location:		line 417, column 10
    Description:	Although the value stored to 'rc' is used in the
          enclosing expression, the value is never actually read from 'rc'

But there was a leak, too, upon any but the first failure.
This fixes both.

>From 141ba8bab2de00c911017bff6fca240c72a80633 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering at redhat.com>
Date: Fri, 4 Sep 2009 16:12:35 +0200
Subject: [PATCH] lxc_container.c: avoid a leak on error paths

* src/lxc_container.c (lxcContainerMountBasicFS): Don't leak upon failure.
Add "cleanup:" label and change each post-allocation failure to
use "goto cleanup" rather than returning immediately.
---
 src/lxc_container.c |   20 ++++++++++++--------
 1 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/lxc_container.c b/src/lxc_container.c
index 2073864..f4381e7 100644
--- a/src/lxc_container.c
+++ b/src/lxc_container.c
@@ -1,6 +1,6 @@
 /*
  * Copyright IBM Corp. 2008
- * Copyright Red Hat 2008
+ * Copyright Red Hat 2008-2009
  *
  * lxc_container.c: file description
  *
@@ -384,12 +384,12 @@ static int lxcContainerMountBasicFS(virDomainFSDefPtr root)
         { "none", "/selinux", "selinuxfs" },
 #endif
     };
-    int i, rc;
+    int i, rc = -1;
     char *devpts;

     if (virAsprintf(&devpts, "/.oldroot%s/dev/pts", root->src) < 0) {
         virReportOOMError(NULL);
-        return -1;
+        return rc;
     }

     for (i = 0 ; i < ARRAY_CARDINALITY(mnts) ; i++) {
@@ -397,31 +397,35 @@ static int lxcContainerMountBasicFS(virDomainFSDefPtr root)
             virReportSystemError(NULL, errno,
                                  _("failed to mkdir %s"),
                                  mnts[i].src);
-            return -1;
+            goto cleanup;
         }
         if (mount(mnts[i].src, mnts[i].dst, mnts[i].type, 0, NULL) < 0) {
             virReportSystemError(NULL, errno,
                                  _("failed to mount %s on %s"),
                                  mnts[i].type, mnts[i].type);
-            return -1;
+            goto cleanup;
         }
     }

     if ((rc = virFileMakePath("/dev/pts") < 0)) {
         virReportSystemError(NULL, rc, "%s",
                              _("cannot create /dev/pts"));
-        return -1;
+        goto cleanup;
     }

     VIR_DEBUG("Trying to move %s to %s", devpts, "/dev/pts");
     if ((rc = mount(devpts, "/dev/pts", NULL, MS_MOVE, NULL)) < 0) {
         virReportSystemError(NULL, errno, "%s",
                              _("failed to mount /dev/pts in container"));
-        return -1;
+        goto cleanup;
     }
+
+    rc = 0;
+
+ cleanup:
     VIR_FREE(devpts);

-    return 0;
+    return rc;
 }

 static int lxcContainerPopulateDevices(void)
--
1.6.4.2.409.g85dc3