[libvirt] [PATCH]: file backed usb massstorage #3

[Jim Meyering]

Guido Günther <agx at sigxcpu.org> wrote:
> attached is version three of the file backed usb massstorage patch.
>
> * handle type != DISK case
> * on OOM use VIR_ERR_NO_MEMORY instead of VIR_ERR_OPERAION_FAILED
> * RelaxNG schema update
> * testcase
...

ACK, once you fix the following:

>>From 123763836d1fe71e6180c36a75690ceec0174f8c Mon Sep 17 00:00:00 2001
> From: Guido Guenther <agx at sigxcpu.org>
> Date: Sun, 3 Aug 2008 01:07:00 +0200
> Subject: [PATCH] usbmass: use files as USB disks
...
> diff --git a/src/qemu_conf.c b/src/qemu_conf.c
...
> +#define ADD_USBDISK(thisarg)                                            \
> +    do {                                                                \
> +        ADD_ARG_LIT("-usbdevice");                                      \
> +        ADD_ARG_SPACE;                                                  \
> +        if ((asprintf(&qargv[qargc++], "disk:%s", thisarg)) == -1)      \
> +            goto no_memory;                                             \

Set qargv[qargc-1] = NULL before the "goto", since upon asprintf
failure it's undefined -- and the subsequent attempt to free it
may well evoke a segfault.

> +    } while (0)
...
> diff --git a/src/qemu_driver.c b/src/qemu_driver.c
> index ef4e158..118d423 100644
> --- a/src/qemu_driver.c
> +++ b/src/qemu_driver.c
> @@ -2978,6 +2978,43 @@ static int qemudDomainAttachCdromDevice(virDomainPtr dom,
>      return 0;
>  }
>
> +static int qemudDomainAttachUsbMassstorageDevice(virDomainPtr dom, virDomainDeviceDefPtr dev)
> +{
> +    struct qemud_driver *driver = (struct qemud_driver *)dom->conn->privateData;
> +    virDomainObjPtr vm = virDomainFindByUUID(driver->domains, dom->uuid);

This should handle the case in which vm == NULL.
Otherwise, qemudMonitorCommand will dereference NULL.
...

>>From a714b14a13f97b824c288fc40165ef9fe5fbaae0 Mon Sep 17 00:00:00 2001
> From: Guido Guenther <agx at sigxcpu.org>
> Date: Thu, 7 Aug 2008 14:39:35 +0200
> Subject: [PATCH] usbmass: testcase for file as src for usb disk
...
> diff --git a/tests/qemuxml2argvdata/qemuxml2argv-disk-usb.args b/tests/qemuxml2argvdata/qemuxml2argv-disk-usb.args
> new file mode 100644
> index 0000000..60a8317
> --- /dev/null
> +++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-usb.args
> @@ -0,0 +1 @@
> +/usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -monitor pty -no-acpi -boot c -hda /dev/HostVG/QEMUGuest1 -usbdevice disk:/tmp/usbdisk.img -net none -serial none -parallel none -usb
> \ No newline at end of file

Please add a newline and split the long line:

  /usr/bin/qemu -S -M pc -m 214 -smp 1 -nographic -monitor pty -no-acpi \
    -boot c -hda /dev/HostVG/QEMUGuest1 -usbdevice disk:/tmp/usbdisk.img \
    -net none -serial none -parallel none -usb