spec: Modularize the storage driver

Create a new set of sub-packages containing the new storage driver
modules so that certain heavy-weight backends (gluster, rbd) can be
installed separately only if required.

To keep backward compatibility the 'libvirt-driver-storage' package
will be turned into a virtual package pulling in all the new storage
backend sub-packages. The storage driver module will be moved into
libvirt-driver-storage-core including the filesystem backend which is
mandatory.

This then allows to make libvirt-daemon-driver-qemu depend only on the
core of the storage driver.

All other meta-packages still depend on the full storage driver and thus
pull in all the backends.

libvirt.spec.in

@@ -585,35 +585,13 @@ Requires: libvirt-daemon = %{version}-%{release}
 The secret driver plugin for the libvirtd daemon, providing
 an implementation of the secret key APIs.
 
-
-%package daemon-driver-storage
-Summary: Storage driver plugin for the libvirtd daemon
+%package daemon-driver-storage-core
+Summary: Storage driver plugin including base backends for the libvirtd daemon
 Group: Development/Libraries
 Requires: libvirt-daemon = %{version}-%{release}
 Requires: nfs-utils
 # For mkfs
 Requires: util-linux
-# For glusterfs
-%if 0%{?fedora}
-Requires: glusterfs-client >= 2.0.1
-%endif
-# gluster cli tool for pool discovery
-%if (0%{?fedora} || 0%{?with_storage_gluster})
-Requires: /usr/sbin/gluster
-%endif
-# For LVM drivers
-Requires: lvm2
-# For ISCSI driver
-Requires: iscsi-initiator-utils
-# For disk driver
-Requires: parted
-Requires: device-mapper
-# For multipath support
-Requires: device-mapper
-%if %{with_storage_sheepdog}
-# For Sheepdog support
-Requires: sheepdog
-%endif
 %if %{with_qemu}
 # From QEMU RPMs
 Requires: /usr/bin/qemu-img
@@ -624,6 +602,128 @@ Requires: /usr/sbin/qcow-create
     %endif
 %endif
 
+%description daemon-driver-storage-core
+The storage driver plugin for the libvirtd daemon, providing
+an implementation of the storage APIs using files, local disks, LVM, SCSI,
+iSCSI, and multipath storage.
+
+%package daemon-driver-storage-logical
+Summary: Storage driver plugin for lvm volumes
+Group: Development/Libraries
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
+Requires: lvm2
+
+%description daemon-driver-storage-logical
+The storage driver backend adding implementation of the storage APIs for block
+volumes using lvm.
+
+
+%package daemon-driver-storage-disk
+Summary: Storage driver plugin for disk
+Group: Development/Libraries
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
+Requires: parted
+Requires: device-mapper
+
+%description daemon-driver-storage-disk
+The storage driver backend adding implementation of the storage APIs for block
+volumes using the host disks.
+
+
+%package daemon-driver-storage-scsi
+Summary: Storage driver plugin for local scsi devices
+Group: Development/Libraries
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
+
+%description daemon-driver-storage-scsi
+The storage driver backend adding implementation of the storage APIs for scsi
+host devices.
+
+
+%package daemon-driver-storage-iscsi
+Summary: Storage driver plugin for iscsi
+Group: Development/Libraries
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
+Requires: iscsi-initiator-utils
+
+%description daemon-driver-storage-iscsi
+The storage driver backend adding implementation of the storage APIs for iscsi
+volumes using the host iscsi stack.
+
+
+%package daemon-driver-storage-mpath
+Summary: Storage driver plugin for multipath volumes
+Group: Development/Libraries
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
+Requires: device-mapper
+
+%description daemon-driver-storage-mpath
+The storage driver backend adding implementation of the storage APIs for
+multipath storage using device mapper.
+
+
+%if %{with_storage_gluster}
+%package daemon-driver-storage-gluster
+Summary: Storage driver plugin for gluster
+Group: Development/Libraries
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
+    %if 0%{?fedora}
+Requires: glusterfs-client >= 2.0.1
+    %endif
+    %if (0%{?fedora} || 0%{?with_storage_gluster})
+Requires: /usr/sbin/gluster
+    %endif
+
+%description daemon-driver-storage-gluster
+The storage driver backend adding implementation of the storage APIs for gluster
+volumes using libgfapi.
+%endif
+
+
+%if %{with_storage_rbd}
+%package daemon-driver-storage-rbd
+Summary: Storage driver plugin for rbd
+Group: Development/Libraries
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
+
+%description daemon-driver-storage-rbd
+The storage driver backend adding implementation of the storage APIs for rbd
+volumes using the ceph protocol.
+%endif
+
+
+%if %{with_storage_sheepdog}
+%package daemon-driver-storage-sheepdog
+Summary: Storage driver plugin for sheepdog
+Group: Development/Libraries
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
+Requires: sheepdog
+
+%description daemon-driver-storage-sheepdog
+The storage driver backend adding implementation of the storage APIs for
+sheepdog volumes using.
+%endif
+
+
+%package daemon-driver-storage
+Summary: Storage driver plugin including all backends for the libvirtd daemon
+Group: Development/Libraries
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
+Requires: libvirt-daemon-driver-storage-disk = %{version}-%{release}
+Requires: libvirt-daemon-driver-storage-logical = %{version}-%{release}
+Requires: libvirt-daemon-driver-storage-scsi = %{version}-%{release}
+Requires: libvirt-daemon-driver-storage-iscsi = %{version}-%{release}
+Requires: libvirt-daemon-driver-storage-mpath = %{version}-%{release}
+%if %{with_storage_gluster}
+Requires: libvirt-daemon-driver-storage-gluster = %{version}-%{release}
+%endif
+%if %{with_storage_rbd}
+Requires: libvirt-daemon-driver-storage-rbd = %{version}-%{release}
+%endif
+%if %{with_storage_sheepdog}
+Requires: libvirt-daemon-driver-storage-sheepdog = %{version}-%{release}
+%endif
+
 %description daemon-driver-storage
 The storage driver plugin for the libvirtd daemon, providing
 an implementation of the storage APIs using LVM, iSCSI,
@@ -637,7 +737,7 @@ Group: Development/Libraries
 Requires: libvirt-daemon = %{version}-%{release}
 # There really is a hard cross-driver dependency here
 Requires: libvirt-daemon-driver-network = %{version}-%{release}
-Requires: libvirt-daemon-driver-storage = %{version}-%{release}
+Requires: libvirt-daemon-driver-storage-core = %{version}-%{release}
 Requires: /usr/bin/qemu-img
 # For image compression
 Requires: gzip
@@ -1694,21 +1794,39 @@ exit 0
 %{_libdir}/%{name}/connection-driver/libvirt_driver_secret.so
 
 %files daemon-driver-storage
+
+%files daemon-driver-storage-core
 %attr(0755, root, root) %{_libexecdir}/libvirt_parthelper
 %{_libdir}/%{name}/connection-driver/libvirt_driver_storage.so
 %{_libdir}/%{name}/storage-backend/libvirt_storage_backend_fs.so
+
+%files daemon-driver-storage-disk
 %{_libdir}/%{name}/storage-backend/libvirt_storage_backend_disk.so
+
+%files daemon-driver-storage-logical
 %{_libdir}/%{name}/storage-backend/libvirt_storage_backend_logical.so
+
+%files daemon-driver-storage-scsi
 %{_libdir}/%{name}/storage-backend/libvirt_storage_backend_scsi.so
+
+%files daemon-driver-storage-iscsi
 %{_libdir}/%{name}/storage-backend/libvirt_storage_backend_iscsi.so
+
+%files daemon-driver-storage-mpath
 %{_libdir}/%{name}/storage-backend/libvirt_storage_backend_mpath.so
+
 %if %{with_storage_gluster}
+%files daemon-driver-storage-gluster
 %{_libdir}/%{name}/storage-backend/libvirt_storage_backend_gluster.so
 %endif
+
 %if %{with_storage_rbd}
+%files daemon-driver-storage-rbd
 %{_libdir}/%{name}/storage-backend/libvirt_storage_backend_rbd.so
 %endif
+
 %if %{with_storage_sheepdog}
+%files daemon-driver-storage-sheepdog
 %{_libdir}/%{name}/storage-backend/libvirt_storage_backend_sheepdog.so
 %endif