[libvirt] [PATCH] Add <filesystem> support to Qemu's attach_device

[Michal Privoznik]

On 04.02.2014 10:37, Teto wrote:
> Hi,
>
> The following patch was generated with format patch & checked with
> syntax-check. It is really short and adds a new function
> virDomainFSInsert which is called when Qemu driver is requested t
> attach a filesystem device.
>
> Matt
>
>
> 0001-This-commit-allows-to-register-filesystem-in-qemu-vi.patch
>
>
>  From f8c0612c48c06c61199693743d98c251ba4d887e Mon Sep 17 00:00:00 2001
> From: Matt<mattator at gmail.com>
> Date: Mon, 3 Feb 2014 17:42:56 +0100
> Subject: [PATCH] This commit allows to register <filesystem> in qemu via the
>   attach_device function (which would previsouly return an error).
>
> For this purpose I've introduced a new function "virDomainFSInsert" and
> added the necessary code in the qemu driver.
>
> It compares filesystems based on their "destination" folder. So if 2
> filesystems share a same destination, they are considered equal and the
> Qemu driver would reject a new insertion.
> ---
>   src/conf/domain_conf.c   | 12 ++++++++++++
>   src/conf/domain_conf.h   |  1 +
>   src/libvirt_private.syms |  1 +
>   src/qemu/qemu_driver.c   | 18 ++++++++++++++++++
>   4 files changed, 32 insertions(+)
>
> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
> index 28e24f9..3f4dbfe 100644
> --- a/src/conf/domain_conf.c
> +++ b/src/conf/domain_conf.c
> @@ -17933,6 +17933,18 @@ virDiskNameToBusDeviceIndex(virDomainDiskDefPtr disk,
>       return 0;
>   }
>
> +
> +int
> +virDomainFSInsert(virDomainDefPtr def, virDomainFSDefPtr fs)
> +{
> +
> +    if (VIR_REALLOC_N(def->fss, def->nfss+1) < 0)
> +        return -1;
> +
> +    def->fss[def->nfss++]  = fs;
> +    return 0;
> +}
> +

While this works perfectly, we can save some lines by calling 
VIR_APPEND_ELEMENT().

>   virDomainFSDefPtr
>   virDomainGetRootFilesystem(virDomainDefPtr def)
>   {
> diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
> index d8f2e49..d749e68 100644
> --- a/src/conf/domain_conf.h
> +++ b/src/conf/domain_conf.h
> @@ -2555,6 +2555,7 @@ int virDiskNameToBusDeviceIndex(virDomainDiskDefPtr disk,
>                                   int *devIdx);
>
>   virDomainFSDefPtr virDomainGetRootFilesystem(virDomainDefPtr def);
> +int virDomainFSInsert(virDomainDefPtr def, virDomainFSDefPtr fs);
>   int virDomainFSIndexByName(virDomainDefPtr def, const char *name);
>   int virDomainVideoDefaultType(const virDomainDef *def);
>   int virDomainVideoDefaultRAM(const virDomainDef *def, int type);
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 1a8d088..e872960 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -221,6 +221,7 @@ virDomainFeatureStateTypeFromString;
>   virDomainFeatureStateTypeToString;
>   virDomainFSDefFree;
>   virDomainFSIndexByName;
> +virDomainFSInsert;
>   virDomainFSTypeFromString;
>   virDomainFSTypeToString;
>   virDomainFSWrpolicyTypeFromString;
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 0128356..f2bac0d 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -6606,6 +6606,7 @@ qemuDomainAttachDeviceConfig(virQEMUCapsPtr qemuCaps,
>       virDomainHostdevDefPtr hostdev;
>       virDomainLeaseDefPtr lease;
>       virDomainControllerDefPtr controller;
> +    virDomainFSDefPtr fs;
>
>       switch (dev->type) {
>       case VIR_DOMAIN_DEVICE_DISK:
> @@ -6687,6 +6688,23 @@ qemuDomainAttachDeviceConfig(virQEMUCapsPtr qemuCaps,
>           dev->data.chr = NULL;
>           break;
>
> +    case VIR_DOMAIN_DEVICE_FS:
> +        {
> +            fs = dev->data.fs;
> +            if (virDomainFSIndexByName(vmdef, fs->dst) >= 0) {
> +                VIR_INFO("Identical FS found");
> +                virReportError(VIR_ERR_OPERATION_INVALID,
> +                             "%s", _("Target already exists"));
> +                return -1;
> +            }
> +
> +            if (virDomainFSInsert(vmdef, fs) < 0) {
> +                return -1;
> +            }
> +            dev->data.fs = NULL;
> +        }
> +        break;
> +

There is no need to enclose the body in { }. Nor for VIR_INFO.

While at this - can you implement the detach counterpart? Again, in 
config level is fine for now.

However, I believe our push policy doesn't allow in patches that are 
missing real name (first and last one at least). So can you fix that too?

Michal