[libvirt] [PATCH] daemon: fix fd leak on libvirtd

[ajia at redhat.com]

From: Alex Jia <ajia at redhat.com>

The codes hasn't close a pipe decriptor statuspipe[0] before exiting,
moreover, should also close all of opening fds on error path to 
avoid fd leaks. 

In addition, I think other fds leak doesen't belong to libvirtd,
so this patch hasn't fixed them.  

Detected by valgrind. Leaks introduced in commit 4296cea.

* daemon/libvirtd.c: fix fd leak on libvirt daemon.

* How to reproduce?
  % service libvirtd stop
  % valgrind -v --track-fds=yes /usr/sbin/libvirtd --daemon

* Actual valgrind result:

==16804== FILE DESCRIPTORS: 7 open at exit.
==16804== Open file descriptor 7:
==16804==    at 0x321FAD8B87: pipe (in /lib64/libc-2.12.so)
==16804==    by 0x41F34D: daemonForkIntoBackground (libvirtd.c:186)
==16804==    by 0x4207A0: main (libvirtd.c:1420)

Signed-off-by: Alex Jia <ajia at redhat.com>
---
 daemon/libvirtd.c |   14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
index d7a03d7..b05f126 100644
--- a/daemon/libvirtd.c
+++ b/daemon/libvirtd.c
@@ -184,7 +184,7 @@ static int daemonForkIntoBackground(const char *argv0)
 {
     int statuspipe[2];
     if (pipe(statuspipe) < 0)
-        return -1;
+        goto error;
 
     int pid = fork();
     switch (pid) {
@@ -219,7 +219,7 @@ static int daemonForkIntoBackground(const char *argv0)
             case 0:
                 return statuspipe[1];
             case -1:
-                return -1;
+                goto error;
             default:
                 _exit(0);
             }
@@ -232,7 +232,7 @@ static int daemonForkIntoBackground(const char *argv0)
         }
 
     case -1:
-        return -1;
+        goto error;
 
     default:
         {
@@ -243,7 +243,7 @@ static int daemonForkIntoBackground(const char *argv0)
 
             /* We wait to make sure the first child forked successfully */
             if (virPidWait(pid, NULL) < 0)
-                return -1;
+                goto error;
 
             /* Now block until the second child initializes successfully */
         again:
@@ -257,9 +257,15 @@ static int daemonForkIntoBackground(const char *argv0)
                           "--daemon for more info.\n"), argv0,
                         virDaemonErrTypeToString(status));
             }
+            VIR_FORCE_CLOSE(statuspipe[0]);
             _exit(ret == 1 && status == 0 ? 0 : 1);
         }
     }
+
+error:
+    VIR_FORCE_CLOSE(statuspipe[0]);
+    VIR_FORCE_CLOSE(statuspipe[1]);
+    return -1;
 }
 
 
-- 
1.7.1