[libvirt] [PATCHv7.6 9/9] blockjob: relabel entire existing chain

When using block copy to pivot over to a new chain, the backing files for the new chain might still need labeling (particularly if the user passes --reuse-ext with a relative backing file name). Relabeling a file that is already labeled won't hurt, so this just labels the entire chain at the point of the pivot. https://bugzilla.redhat.com/show_bug.cgi?id=856247 * src/qemu/qemu_driver.c (qemuDomainBlockPivot): Relabel chain before asking qemu to pivot. --- Diff from v7.5: relabel the new disk chain, not the old chain src/qemu/qemu_driver.c | 37 +++++++++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 8201c9d..828ad6e 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -12596,6 +12596,9 @@ qemuDomainBlockPivot(virConnectPtr conn, virDomainBlockJobInfo info; bool reopen = qemuCapsGet(priv->caps, QEMU_CAPS_DRIVE_REOPEN); bool resume = false; + virCgroupPtr cgroup = NULL; + char *oldsrc = NULL; + char *olddriver = NULL; /* Probe the status, if needed. */ if (!disk->mirroring) { @@ -12643,6 +12646,30 @@ qemuDomainBlockPivot(virConnectPtr conn, } } + /* We previously labeled only the top-level image; but if the + * image includes a relative backing file, the pivot may result in + * qemu needing to open the entire backing chain, so we need to + * label the entire chain. This action is safe even if the + * backing chain has already been labeled. */ + if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_DEVICES) && + virCgroupForDomain(driver->cgroup, vm->def->name, &cgroup, 0)) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Unable to find cgroup for %s"), + vm->def->name); + goto cleanup; + } + oldsrc = disk->src; + olddriver = disk->driverType; + disk->src = disk->mirror; + disk->driverType = disk->mirrorFormat; + if ((cgroup && qemuSetupDiskCgroup(driver, vm, cgroup, disk) < 0) || + virSecurityManagerSetImageLabel(driver->securityManager, vm->def, + disk) < 0) { + disk->src = oldsrc; + disk->driverType = olddriver; + goto cleanup; + } + /* Attempt the pivot. */ qemuDomainObjEnterMonitorWithDriver(driver, vm); ret = qemuMonitorDrivePivot(priv->mon, device, disk->mirror, @@ -12662,10 +12689,8 @@ qemuDomainBlockPivot(virConnectPtr conn, * portion of the chain, and is made more difficult by the * fact that we aren't tracking the full chain ourselves; so * for now, we leak the access to the original. */ - VIR_FREE(disk->src); - VIR_FREE(disk->driverType); - disk->src = disk->mirror; - disk->driverType = disk->mirrorFormat; + VIR_FREE(oldsrc); + VIR_FREE(olddriver); disk->mirror = NULL; disk->mirrorFormat = NULL; disk->mirroring = false; @@ -12677,12 +12702,16 @@ qemuDomainBlockPivot(virConnectPtr conn, * 'query-block', to see what state we really got left in * before killing the mirroring job? And just as on the * success case, there's security labeling to worry about. */ + disk->src = oldsrc; + disk->driverType = olddriver; VIR_FREE(disk->mirror); VIR_FREE(disk->mirrorFormat); disk->mirroring = false; } cleanup: + if (cgroup) + virCgroupFree(&cgroup); if (resume && virDomainObjIsActive(vm) && qemuProcessStartCPUs(driver, vm, conn, VIR_DOMAIN_RUNNING_UNPAUSED, -- 1.7.11.4