[libvirt] [PATCH 21/23] Add support for hotplug/unplug of host misc devices in LXC

Gao feng gaofeng at cn.fujitsu.com
Fri Dec 14 12:10:32 UTC 2012


On 2012/12/01 04:26, Daniel P. Berrange wrote:
> From: "Daniel P. Berrange" <berrange at redhat.com>
> 
> Wire up the attach/detach device drivers in LXC to support the
> hotplug/unplug of host misc devices.
> 
> Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
> ---
>  src/lxc/lxc_driver.c | 194 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 194 insertions(+)
> 
> diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
> index 27ee3d7..17445a7 100644
> --- a/src/lxc/lxc_driver.c
> +++ b/src/lxc/lxc_driver.c
> @@ -3474,6 +3474,123 @@ cleanup:
>  
>  
>  static int
> +lxcDomainAttachDeviceHostdevMiscLive(virLXCDriverPtr driver,
> +                                     virDomainObjPtr vm,
> +                                     virDomainDeviceDefPtr dev)
> +{
> +    virLXCDomainObjPrivatePtr priv = vm->privateData;
> +    virDomainHostdevDefPtr def = dev->data.hostdev;
> +    virCgroupPtr group = NULL;
> +    int ret = -1;
> +    char *dst;
> +    char *vroot;
> +    struct stat sb;
> +    bool created = false;
> +    mode_t mode = 0;
> +
> +    if (!priv->initpid) {
> +        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
> +                       _("Cannot attach disk until init PID is known"));
> +        goto cleanup;
> +    }
> +
> +    if (!def->source.caps.u.misc.chardev) {
> +        virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                       _("Missing storage block path"));
> +        goto cleanup;
> +    }
> +
> +    if (virDomainHostdevFind(vm->def, def, NULL) >= 0) {
> +        virReportError(VIR_ERR_OPERATION_FAILED, "%s",
> +                       _("host device already exists"));
> +        return -1;
> +    }
> +
> +    if (stat(def->source.caps.u.misc.chardev, &sb) < 0) {
> +        virReportSystemError(errno,
> +                             _("Unable to access %s"),
> +                             def->source.caps.u.misc.chardev);
> +        goto cleanup;
> +    }
> +
> +    if (!S_ISCHR(sb.st_mode)) {
> +        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> +                       _("Hostdev source %s must be a block device"),
> +                       def->source.caps.u.misc.chardev);
> +        goto cleanup;
> +    }
> +
> +    if (virAsprintf(&vroot, "/proc/%llu/root",
> +                    (unsigned long long)priv->initpid) < 0) {
> +        virReportOOMError();
> +        goto cleanup;
> +    }
> +
> +    if (virAsprintf(&dst, "%s/%s",
> +                    vroot,
> +                    def->source.caps.u.misc.chardev) < 0) {
> +        virReportOOMError();
> +        goto cleanup;
> +    }
> +
> +    if (VIR_REALLOC_N(vm->def->hostdevs, vm->def->nhostdevs+1) < 0) {
> +        virReportOOMError();
> +        goto cleanup;
> +    }
> +
> +    mode = 0700 | S_IFCHR;
> +
> +    VIR_DEBUG("Creating dev %s (%d,%d)",
> +              def->source.caps.u.misc.chardev,
> +              major(sb.st_rdev), minor(sb.st_rdev));
> +    if (mknod(dst, mode, sb.st_rdev) < 0) {
> +        virReportSystemError(errno,
> +                             _("Unable to create device %s"),
> +                             dst);
> +        goto cleanup;
> +    }
> +    created = true;
> +
> +    if (virSecurityManagerSetHostdevLabel(driver->securityManager,
> +                                          vm->def, def, vroot) < 0)
> +        goto cleanup;
> +
> +    if (!lxcCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_DEVICES)) {
> +        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
> +                       _("devices cgroup isn't mounted"));
> +        goto cleanup;
> +    }
> +
> +    if (virCgroupForDomain(driver->cgroup, vm->def->name, &group, 0) != 0) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("cannot find cgroup for domain %s"), vm->def->name);
> +        goto cleanup;
> +    }
> +
> +    if (virCgroupAllowDevicePath(group, def->source.caps.u.misc.chardev,
> +                                 VIR_CGROUP_DEVICE_RW |
> +                                 VIR_CGROUP_DEVICE_MKNOD) != 0) {

VIR_CGROUP_DEVICE_RWM

> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("cannot allow device %s for domain %s"),
> +                       def->source.caps.u.misc.chardev, vm->def->name);
> +        goto cleanup;
> +    }
> +
> +    vm->def->hostdevs[vm->def->nhostdevs++] = def;
> +
> +    ret = 0;
> +
> +cleanup:
> +    virDomainAuditHostdev(vm, def, "attach", ret == 0);
> +    if (group)
> +        virCgroupFree(&group);
> +    if (dst && created && ret < 0)
> +        unlink(dst);
> +    return ret;
> +}
> +


dst and vroot need be freed.

ACK




More information about the libvir-list mailing list