virsh: Plug memory leak on cmdUndefine

Detected by valgrind. Leak is introduced in commit 3bb6bcf.

Free 'vol' memory before allocating memory, the codes will miss one time
free when 'vol_i = nvolumes' in for loop, so plug memory leak.

* tools/virsh.c: fix memory leak on cmdUndefine.

* How to reproduce?
% dd if=/dev/null of=/var/lib/libvirt/images/foo bs=1 count=1 seek=10M
% virsh define foo.xml                   (disk source file points to '/var/lib/libvirt/images/foo')
% virsh vol-clone foo foo-clone default  (the original guest name is 'foo')
% virsh pool-refresh default
% virsh vol-list default                 (make sure 'foo-clone' volume exists)
% virsh define foo-clone.xml             (disk source file points to '/var/lib/libvirt/images/foo-clone')
% valgrind -v --leak-check=full virsh undefine foo-clone --remove-all-storage

* Actual results:

1. virsh output
Domain foo-clone has been undefined
Volume '/var/lib/libvirt/images/foo-clone' removed.

error: Failed to disconnect from the hypervisor, 1 leaked reference(s)

2. valgrind result

==6515== 92 (40 direct, 52 indirect) bytes in 1 blocks are definitely lost in loss record 46 of 69
==6515==    at 0x4A04A28: calloc (vg_replace_malloc.c:467)
==6515==    by 0x4C89B71: virAlloc (memory.c:101)
==6515==    by 0x4CFCACE: virGetStorageVol (datatypes.c:724)
==6515==    by 0x4D4A8E0: remoteStorageVolLookupByPath (remote_driver.c:4664)
==6515==    by 0x4D07153: virStorageVolLookupByPath (libvirt.c:12508)
==6515==    by 0x4270E6: cmdUndefine (virsh.c:2828)
==6515==    by 0x4151B6: vshCommandRun (virsh.c:17693)
==6515==    by 0x4264D3: main (virsh.c:19270)
==6515==
==6515== LEAK SUMMARY:
==6515==    definitely lost: 40 bytes in 1 blocks

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=786674

Signed-off-by: Alex Jia <ajia@redhat.com>

diff --git a/tools/virsh.c b/tools/virsh.c
index c8fd4488da5205f7fd5852145627586f67f96820..af781025ebcda0315a5d16af5138d292276cdd66 100644 (file)
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -2875,6 +2875,8 @@ cleanup:
     VIR_FREE(volume_tokens);
     VIR_FREE(def);
     VIR_FREE(vol_nodes);
+    if (vol)
+        virStorageVolFree(vol);
     xmlFreeDoc(doc);
     xmlXPathFreeContext(ctxt);
     virDomainFree(dom);