Re: [libvirt] [PATCH] Fix handling of disk backing stores with cgroups

The cgroups ACL code was only allowing the primary disk image. It is possible to chain images together, so we need to search for backing stores and add them to the ACL too. Since the ACL only handles block devices, we ignore the EINVAL we get from plain files. In addition it was missing code to teardown the cgroup when hot-unplugging a disk * src/qemu/qemu_driver.c: Allow backing stores in cgroup ACLs and add missing teardown code in unplug path

+static int qemuSetupDiskCgroup(virCgroupPtr cgroup, + virDomainObjPtr vm, + virDomainDiskDefPtr disk) +{ + char *path = disk->src; + int ret = -1; + + while (path != NULL) { + virStorageFileMetadata meta; + int rc; + + VIR_DEBUG("Process path %s for disk", path); + rc = virCgroupAllowDevicePath(cgroup, path);

+ if (rc != 0) { + /* Get this for non-block devices */ + if (rc == -EINVAL) { + VIR_DEBUG("Ignoring EINVAL for %s", path); + } else { + virReportSystemError(-rc, + _("Unable to allow device %s for %s"),

+ path, vm->def->name); + if (path != disk->src) + VIR_FREE(path); + goto cleanup; + } + } + + memset(&meta, 0, sizeof(meta)); + + rc = virStorageFileGetMetadata(path, &meta); + + if (path != disk->src) + VIR_FREE(path); + path = NULL; + + if (rc < 0) + goto cleanup; + + path = meta.backingStore; + } while (path != NULL); + + ret = 0; + +cleanup: + return ret; +} + + +static int qemuTeardownDiskCgroup(virCgroupPtr cgroup, + virDomainObjPtr vm, + virDomainDiskDefPtr disk)