[libvirt] [PATCH 1/2] logical: implement volume resize

[apolyakov at beget.ru]

From: Alexander Polyakov <apolyakov at beget.com>

Add new virStorageBackendLogicalResizeVol function to
implement resize of logical volumes

Sparse volumes are not supported

Signed-off-by: Alexander Polyakov <apolyakov at beget.com>
---
 m4/virt-storage-lvm.m4                |  4 ++++
 src/storage/storage_backend_logical.c | 37 +++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/m4/virt-storage-lvm.m4 b/m4/virt-storage-lvm.m4
index a0ccca7a0..0932995b4 100644
--- a/m4/virt-storage-lvm.m4
+++ b/m4/virt-storage-lvm.m4
@@ -30,6 +30,7 @@ AC_DEFUN([LIBVIRT_STORAGE_CHECK_LVM], [
     AC_PATH_PROG([VGREMOVE], [vgremove], [], [$LIBVIRT_SBIN_PATH])
     AC_PATH_PROG([LVREMOVE], [lvremove], [], [$LIBVIRT_SBIN_PATH])
     AC_PATH_PROG([LVCHANGE], [lvchange], [], [$LIBVIRT_SBIN_PATH])
+    AC_PATH_PROG([LVRESIZE], [lvresize], [], [$LIBVIRT_SBIN_PATH])
     AC_PATH_PROG([VGCHANGE], [vgchange], [], [$LIBVIRT_SBIN_PATH])
     AC_PATH_PROG([VGSCAN], [vgscan], [], [$LIBVIRT_SBIN_PATH])
     AC_PATH_PROG([PVS], [pvs], [], [$LIBVIRT_SBIN_PATH])
@@ -44,6 +45,7 @@ AC_DEFUN([LIBVIRT_STORAGE_CHECK_LVM], [
       if test -z "$VGREMOVE" ; then AC_MSG_ERROR([We need vgremove for LVM storage driver]) ; fi
       if test -z "$LVREMOVE" ; then AC_MSG_ERROR([We need lvremove for LVM storage driver]) ; fi
       if test -z "$LVCHANGE" ; then AC_MSG_ERROR([We need lvchange for LVM storage driver]) ; fi
+      if test -z "$LVRESIZE" ; then AC_MSG_ERROR([We need lvresize for LVM storage driver]) ; fi
       if test -z "$VGCHANGE" ; then AC_MSG_ERROR([We need vgchange for LVM storage driver]) ; fi
       if test -z "$VGSCAN" ; then AC_MSG_ERROR([We need vgscan for LVM storage driver]) ; fi
       if test -z "$PVS" ; then AC_MSG_ERROR([We need pvs for LVM storage driver]) ; fi
@@ -57,6 +59,7 @@ AC_DEFUN([LIBVIRT_STORAGE_CHECK_LVM], [
       if test -z "$VGREMOVE" ; then with_storage_lvm=no ; fi
       if test -z "$LVREMOVE" ; then with_storage_lvm=no ; fi
       if test -z "$LVCHANGE" ; then with_storage_lvm=no ; fi
+      if test -z "$LVRESIZE" ; then with_storage_lvm=no ; fi
       if test -z "$VGCHANGE" ; then with_storage_lvm=no ; fi
       if test -z "$VGSCAN" ; then with_storage_lvm=no ; fi
       if test -z "$PVS" ; then with_storage_lvm=no ; fi
@@ -75,6 +78,7 @@ AC_DEFUN([LIBVIRT_STORAGE_CHECK_LVM], [
       AC_DEFINE_UNQUOTED([VGREMOVE],["$VGREMOVE"],[Location of vgremove program])
       AC_DEFINE_UNQUOTED([LVREMOVE],["$LVREMOVE"],[Location of lvremove program])
       AC_DEFINE_UNQUOTED([LVCHANGE],["$LVCHANGE"],[Location of lvchange program])
+      AC_DEFINE_UNQUOTED([LVRESIZE],["$LVRESIZE"],[Location of lvresize program])
       AC_DEFINE_UNQUOTED([VGCHANGE],["$VGCHANGE"],[Location of vgchange program])
       AC_DEFINE_UNQUOTED([VGSCAN],["$VGSCAN"],[Location of vgscan program])
       AC_DEFINE_UNQUOTED([PVS],["$PVS"],[Location of pvs program])
diff --git a/src/storage/storage_backend_logical.c b/src/storage/storage_backend_logical.c
index 67f70e551..e5cb09922 100644
--- a/src/storage/storage_backend_logical.c
+++ b/src/storage/storage_backend_logical.c
@@ -1072,6 +1072,42 @@ virStorageBackendLogicalVolWipe(virConnectPtr conn,
     return -1;
 }
 
+static int
+virStorageBackendLogicalResizeVol(virConnectPtr conn ATTRIBUTE_UNUSED,
+                                   virStoragePoolObjPtr pool ATTRIBUTE_UNUSED,
+                                   virStorageVolDefPtr vol,
+                                   unsigned long long capacity,
+                                   unsigned int flags)
+{
+    virCheckFlags(VIR_STORAGE_VOL_RESIZE_SHRINK |
+                  VIR_STORAGE_VOL_RESIZE_DELTA, -1);
+
+    bool delta = flags & VIR_STORAGE_VOL_RESIZE_DELTA;
+    bool shrink = flags & VIR_STORAGE_VOL_RESIZE_SHRINK;
+
+    if (vol->target.sparse) {
+        virReportError(VIR_ERR_NO_SUPPORT,
+                        _("logical volume '%s' is sparse, volume resize "
+                            "not supported"),
+                        vol->target.path);
+        return -1;
+    }
+
+    virCommandPtr cmd = virCommandNewArgList(LVRESIZE, "-L", NULL);
+
+    if (delta) {
+        virCommandAddArgFormat(cmd, "%c%lluB", shrink ? '-' : '+',
+                                 capacity);
+    } else {
+        virCommandAddArgFormat(cmd, "%lluB", capacity);
+    }
+    virCommandAddArgFormat(cmd, "%s", vol->target.path);
+    int ret = virCommandRun(cmd, NULL);
+
+    virCommandFree(cmd);
+    return ret;
+}
+
 virStorageBackend virStorageBackendLogical = {
     .type = VIR_STORAGE_POOL_LOGICAL,
 
@@ -1089,6 +1125,7 @@ virStorageBackend virStorageBackendLogical = {
     .uploadVol = virStorageBackendVolUploadLocal,
     .downloadVol = virStorageBackendVolDownloadLocal,
     .wipeVol = virStorageBackendLogicalVolWipe,
+    .resizeVol = virStorageBackendLogicalResizeVol,
 };
 
 
-- 
2.13.5