[libvirt] PATCH: 1/7: Removing state from lxc_vm_t

[Jim Meyering]

"Daniel P. Berrange" <berrange at redhat.com> wrote:
> This patch does some simple re-factoring of the way the TTYs and
> control socket are handled to reduce the amount of state stored
> in the lxc_vm_t structure, in preparation for the switchover to
> the generic domain handling APIs.
...
> diff -r 63b8398c302e src/lxc_driver.c
> --- a/src/lxc_driver.c	Mon Jul 14 12:18:23 2008 +0100
> +++ b/src/lxc_driver.c	Tue Jul 15 11:55:48 2008 +0100
...
> @@ -989,15 +896,18 @@
>                        lxc_vm_t * vm)
>  {
>      int rc = -1;
> -    lxc_vm_def_t *vmDef = vm->def;
> +    int sockpair[2];
...
> +    if (lxcOpenTty(conn, &parentTty, &vm->def->tty, 1) < 0) {
>          goto cleanup;
>      }
>
>      /* open container tty */
> -    if (lxcSetupContainerTty(conn, &(vm->containerTtyFd), &(vm->containerTty)) < 0) {
> +    if (lxcOpenTty(conn, &containerTty, &containerTtyPath, 0) < 0) {
>          goto cleanup;
>      }
>
...
> +    if (0 != socketpair(PF_UNIX, SOCK_STREAM, 0, sockpair)) {
...
>  cleanup:
> -    close(vm->sockpair[LXC_PARENT_SOCKET]);
> -    vm->sockpair[LXC_PARENT_SOCKET] = -1;
> -    close(vm->sockpair[LXC_CONTAINER_SOCKET]);
> -    vm->sockpair[LXC_CONTAINER_SOCKET] = -1;
> +    close(sockpair[0]);
> +    close(sockpair[1]);
> +    VIR_FREE(containerTtyPath);
>
>      return rc;
>  }

All looks fine except for the possibility that
the cleanup code can close undefined sockpair[0,1].
The obvious fix is to initialize them to -1 and not close in that case.

Oh, and the new name, "monitor" (new struct member and local/param in
several functions) would be more readable as "monitor_fd".