[libvirt] [PATCH 6/7] Support NBD backed disks/filesystems in LXC driver

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; The LXC driver can already configure <disk> or <filesystem> devices to use the loop device. This extends it to also allow for use of the NBD device, to support non-raw formats. Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; --- src/lxc/lxc_controller.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 62 insertions(+), 2 deletions(-) diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c index 8f3ca6a..c433fb1 100644 --- a/src/lxc/lxc_controller.c +++ b/src/lxc/lxc_controller.c @@ -403,6 +403,46 @@ static int virLXCControllerSetupLoopDeviceDisk(virDomainDiskDefPtr disk) } +static int virLXCControllerSetupNBDDeviceFS(virDomainFSDefPtr fs) +{ + char *dev; + + if (virFileNBDDeviceAssociate(fs->src, &dev, + !!fs->readonly) < 0) + return -1; + + /* + * We now change it into a block device type, so that + * the rest of container setup 'just works' + */ + fs->type = VIR_DOMAIN_DISK_TYPE_BLOCK; + VIR_FREE(fs->src); + fs->src = dev; + + return 0; +} + + +static int virLXCControllerSetupNBDDeviceDisk(virDomainDiskDefPtr disk) +{ + char *dev; + + if (virFileNBDDeviceAssociate(disk->src, &dev, + !!disk->readonly) < 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 = dev; + + return 0; +} + + static int virLXCControllerSetupLoopDevices(virLXCControllerPtr ctrl) { size_t i; @@ -435,6 +475,9 @@ static int virLXCControllerSetupLoopDevices(virLXCControllerPtr ctrl) goto cleanup; } ctrl->loopDevFds[ctrl->nloopDevs - 1] = fd; + } else if (fs->fsdriver == VIR_DOMAIN_FS_DRIVER_TYPE_NBD) { + if (virLXCControllerSetupNBDDeviceFS(fs) < 0) + goto cleanup; } else { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("fs driver %s is not supported"), @@ -449,8 +492,14 @@ static int virLXCControllerSetupLoopDevices(virLXCControllerPtr ctrl) if (disk->type != VIR_DOMAIN_DISK_TYPE_FILE) continue; - if (!disk->driverName || - STREQ(disk->driverName, "loop")) { + /* If no driverName is set, we prefer 'loop' for + * dealing with raw or undefined formats. Only + * default to 'nbd' for non-raw formats. + */ + if ((disk->driverName && STREQ(disk->driverName, "loop")) || + (!disk->driverName && + (disk->format == VIR_STORAGE_FILE_RAW || + disk->format == VIR_STORAGE_FILE_NONE))) { if (disk->format != VIR_STORAGE_FILE_RAW && disk->format != VIR_STORAGE_FILE_NONE) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, @@ -474,6 +523,17 @@ static int virLXCControllerSetupLoopDevices(virLXCControllerPtr ctrl) goto cleanup; } ctrl->loopDevFds[ctrl->nloopDevs - 1] = fd; + } else if (!disk->driverName || + STREQ(disk->driverName, "nbd")) { + if (disk->cachemode != VIR_DOMAIN_DISK_CACHE_DEFAULT && + disk->cachemode != VIR_DOMAIN_DISK_CACHE_DISABLE) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Disk cache mode %s is not supported"), + virDomainDiskCacheTypeToString(disk->cachemode)); + goto cleanup; + } + if (virLXCControllerSetupNBDDeviceDisk(disk) < 0) + goto cleanup; } else { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, _("disk driver %s is not supported"), -- 1.7.11.7