Re: [libvirt] [PATCH] Add support for disks backed by plain files in LXC

On 03/07/2013 06:41 AM, Daniel P. Berrange wrote: > From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; > > By using a loopback device, disks backed by plain files can > be made available to LXC containers. We make no attempt to > auto-detect format if <driver type="raw"/> is not set, > instead we unconditionally treat that as meaning raw. This > is to avoid the security issues inherant with format > auto-detection > > Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; > --- > src/lxc/lxc_controller.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 65 insertions(+), 2 deletions(-) > > diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c > index a7e715e..176e1be 100644 > --- a/src/lxc/lxc_controller.c > +++ b/src/lxc/lxc_controller.c > @@ -356,7 +356,7 @@ static int virLXCControllerValidateConsoles(virLXCControllerPtr ctrl) > } > > > -static int virLXCControllerSetupLoopDevice(virDomainFSDefPtr fs) > +static int virLXCControllerSetupLoopDeviceFS(virDomainFSDefPtr fs) > { > int lofd; > char *loname = NULL; > @@ -377,6 +377,27 @@ static int virLXCControllerSetupLoopDevice(virDomainFSDefPtr fs) > } > > > +static int virLXCControllerSetupLoopDeviceDisk(virDomainDiskDefPtr disk) > +{ > + int lofd; > + char *loname = NULL; > + > + if ((lofd = virFileLoopDeviceAssociate(disk->src, &loname)) < 0) > + return -1; > + > + /* > + * We now change it into a block device type, so that > + * the rest of container setup 'just works' > + */ > + disk->type = VIR_DOMAIN_DISK_TYPE_BLOCK; > + VIR_FREE(disk->src); > + disk->src = loname; > + loname = NULL; > + > + return lofd; > +} > + > + > static int virLXCControllerSetupLoopDevices(virLXCControllerPtr ctrl) > { > size_t i; > @@ -389,7 +410,7 @@ static int virLXCControllerSetupLoopDevices(virLXCControllerPtr ctrl) > if (fs->type != VIR_DOMAIN_FS_TYPE_FILE) > continue; > > - fd = virLXCControllerSetupLoopDevice(fs); > + fd = virLXCControllerSetupLoopDeviceFS(fs); > if (fd < 0) > goto cleanup; > > @@ -402,6 +423,48 @@ static int virLXCControllerSetupLoopDevices(virLXCControllerPtr ctrl) > ctrl->loopDevFds[ctrl->nloopDevs - 1] = fd; > } > > + for (i = 0 ; i < ctrl->def->ndisks ; i++) { > + virDomainDiskDefPtr disk = ctrl->def->disks[i]; > + int fd; > + > + if (disk->type != VIR_DOMAIN_DISK_TYPE_FILE) > + continue; > + > + switch (disk->format) { > + /* We treat 'none' as meaning 'raw' since we > + * don't want to go into the auto-probing > + * business for security reasons > + */ > + case VIR_STORAGE_FILE_RAW: > + case VIR_STORAGE_FILE_NONE: > + if (disk->driverName && > + STRNEQ(disk->driverName, "loop")) { > + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, > + _("disk driver %s is not supported"), > + disk->driverName); > + goto cleanup; > + } > + > + fd = virLXCControllerSetupLoopDeviceDisk(disk); > + if (fd < 0) > + goto cleanup; Is there a missing break; here?