Re: [Qemu-devel] [PATCH] Merge NBD client/server int qemu-nbd

[Anthony Liguori <anthony@codemonkey.ws>]

Laurent Vivier wrote:
> Hi,
>
> this patch allows to connect directly a disk image file to an NBD
> device. It introduces the use of a unix socket (instead of inet).
>
> - To connect a file to a device:
>
> # qemu-nbd --connect=/dev/nbd0 my_disk.qcow2
>
> Then you can see directly your disk (no need of nbd-client):
>
> # fdisk -l /dev/nbd0
>
> Disk /dev/nbd0: 4294 MB, 4294967296 bytes
> 255 heads, 63 sectors/track, 522 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
>
>      Device Boot      Start         End      Blocks   Id  System
> /dev/nbd0p1   *           1         492     3951958+  83  Linux
> /dev/nbd0p2             493         522      240975    5  Extended
> /dev/nbd0p5             493         522      240943+  82  Linux swap /
> Solaris
>
> - To disconnect the file from the device:
>
> # qemu-nbd --disconnect /dev/nbd0
>
> Regards,
> Laurent
>   
> +static void show_parts(const char *device)
> +{
> +    if (fork() == 0) {
> +        int nbd;
> +
> +	/* wait device */
> +        sleep(1);
>   

This looks like a big red-herring.  What is this sleep waiting for any 
can it be possibly made into something less racy?

Regards,

Anthony Liguori