On 10/18/2012 01:19 PM, Corey Bryant wrote:
> This option can be used for passing file descriptors on the
> command line. It mirrors the existing add-fd QMP command which
> allows an fd to be passed to QEMU via SCM_RIGHTS and added to an
> fd set.
>
> +
> +static int cleanup_add_fd(QemuOpts *opts, void *opaque)
> +{
> + int fd;
> +
> + fd = qemu_opt_get_number(opts, "fd", -1);
> + close(fd);
One other subtle point: Given 'qemu-kvm -add-fd fd=3,set=1 -add-fd
fd=3,set=2', this code will call close(3) twice. In a single-threaded
scenario, we happen to be safe (because we merely ignore that the second
one fails with EBADF), but in a multi-threaded scenario, it is a recipe
for disaster with a chance for closing an fd opened by another thread.
> @@ -3320,6 +3390,14 @@ int main(int argc, char **argv, char **envp)
> exit(1);
> }
>
> + if (qemu_opts_foreach(qemu_find_opts("add-fd"), parse_add_fd, NULL, 1)) {
> + exit(1);
> + }
> +
> + if (qemu_opts_foreach(qemu_find_opts("add-fd"), cleanup_add_fd, NULL, 1)) {
> + exit(1);
> + }
Thankfully, we only ever call that code in main(), prior to spawning
threads. So my positive review still stands.
--
Eric Blake eblake@xxxxxxxxxx +1-919-301-3266
Libvirt virtualization library http://libvirt.org
Attachment:
signature.asc
Description: OpenPGP digital signature
-- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list