[libvirt] [PATCH] virsh: fix memory leak in cmdVolPath code

[Osier Yang]

于 2011年07月27日 11:33, Alex Jia 写道:
> * tools/virsh.c: avoid memory leak in cmdVolPath.
>
> * how to reproduce?
>
>    % dd if=/dev/zero of=/var/lib/libvirt/images/foo.img count=1 bs=10M
>    % virsh pool-refresh default
>    % valgrind -v --leak-check=full virsh vol-path --vol
>       /var/lib/libvirt/images/foo.img
>
> * actual results:
>
> Detected in valgrind run:
>
> ==16436== 32 bytes in 1 blocks are definitely lost in loss record 7 of 22
> ==16436==    at 0x4A05FDE: malloc (vg_replace_malloc.c:236)
> ==16436==    by 0x386A314B3D: xdr_string (in /lib64/libc-2.12.so)
> ==16436==    by 0x3DF8CD770D: xdr_remote_nonnull_string (remote_protocol.c:30)
> ==16436==    by 0x3DF8CD7EC8: xdr_remote_storage_vol_get_path_ret
> (remote_protocol.c:2952)
> ==16436==    by 0x3DF8CDF161: virNetMessageDecodePayload (virnetmessage.c:286)
> ==16436==    by 0x3DF8CDE9E5: virNetClientProgramCall
> (virnetclientprogram.c:318)
> ==16436==    by 0x3DF8CC28A2: call (remote_driver.c:3929)
> ==16436==    by 0x3DF8CC8412: remoteStorageVolGetPath
> (remote_client_bodies.h:5219)
> ==16436==    by 0x3DF8C9BF14: virStorageVolGetPath (libvirt.c:11389)
> ==16436==    by 0x418ECA: cmdVolPath (virsh.c:8754)
> ==16436==    by 0x410CC2: vshCommandRun (virsh.c:12758)
> ==16436==    by 0x41F286: main (virsh.c:14110)
> ==16436==
> ==16436== LEAK SUMMARY:
> ==16436==    definitely lost: 32 bytes in 1 blocks
>
>
> Signed-off-by: Alex Jia<ajia at redhat.com>
> ---
>   tools/virsh.c |    9 ++++++++-
>   1 files changed, 8 insertions(+), 1 deletions(-)
>
> diff --git a/tools/virsh.c b/tools/virsh.c
> index 841df61..d194a8b 100644
> --- a/tools/virsh.c
> +++ b/tools/virsh.c
> @@ -9326,6 +9326,7 @@ cmdVolPath(vshControl *ctl, const vshCmd *cmd)
>   {
>       virStorageVolPtr vol;
>       const char *name = NULL;
> +    char * StorageVolPath;
>
>       if (!vshConnectionUsability(ctl, ctl->conn))
>           return false;
> @@ -9334,7 +9335,13 @@ cmdVolPath(vshControl *ctl, const vshCmd *cmd)
>           return false;
>       }
>
> -    vshPrint(ctl, "%s\n", virStorageVolGetPath(vol));
> +    if ((StorageVolPath = virStorageVolGetPath(vol)) == NULL) {
> +        virStorageVolFree(vol);
> +        return false;
> +    }
> +
> +    vshPrint(ctl, "%s\n", StorageVolPath);
> +    VIR_FREE(StorageVolPath);
>       virStorageVolFree(vol);
>       return true;
>   }

ACK, but it will be better if docs of virStorageVolGetPath in src/libvirt.c
can be updated, (to tell the returned path must be freed by caller).

Osier