[libvirt] [PATCH] rbd: Use rbd_create3 to create RBD format 2 images by default

[Wido den Hollander]

This new RBD format supports snapshotting and cloning. By having
libvirt create images in format 2 end-users of the created images
can benefit of the new RBD format.

Signed-off-by: Wido den Hollander <wido at widodh.nl>
---
 src/storage/storage_backend_rbd.c |   23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/storage/storage_backend_rbd.c b/src/storage/storage_backend_rbd.c
index d9e1789..e79873f 100644
--- a/src/storage/storage_backend_rbd.c
+++ b/src/storage/storage_backend_rbd.c
@@ -435,6 +435,26 @@ cleanup:
     return ret;
 }
 
+static int virStorageBackendRBDCreateImage(rados_ioctx_t io,
+                                           char *name, long capacity)
+{
+    int order = 0;
+    #if LIBRBD_VERSION_CODE > 260
+    uint64_t features = 3;
+    uint64_t stripe_count = 1;
+    uint64_t stripe_unit = 4194304;
+
+    if (rbd_create3(io, name, capacity, features, &order,
+                    stripe_count, stripe_unit) < 0) {
+    #else
+    if (rbd_create(io, name, capacity, &order) < 0) {
+    #endif
+        return -1;
+    }
+
+    return 0;
+}
+
 static int virStorageBackendRBDCreateVol(virConnectPtr conn,
                                          virStoragePoolObjPtr pool,
                                          virStorageVolDefPtr vol)
@@ -442,7 +462,6 @@ static int virStorageBackendRBDCreateVol(virConnectPtr conn,
     virStorageBackendRBDStatePtr ptr;
     ptr.cluster = NULL;
     ptr.ioctx = NULL;
-    int order = 0;
     int ret = -1;
 
     VIR_DEBUG("Creating RBD image %s/%s with size %llu",
@@ -467,7 +486,7 @@ static int virStorageBackendRBDCreateVol(virConnectPtr conn,
         goto cleanup;
     }
 
-    if (rbd_create(ptr.ioctx, vol->name, vol->capacity, &order) < 0) {
+    if (virStorageBackendRBDCreateImage(ptr.ioctx, vol->name, vol->capacity) < 0) {
         virReportError(VIR_ERR_INTERNAL_ERROR,
                        _("failed to create volume '%s/%s'"),
                        pool->def->source.name,
-- 
1.7.9.5