[libvirt] [PATCHv3 2/5] snapshot: qemu: Fix detection of external snapshots when deleting

[Peter Krempa]

This patch adds a helper to determine if snapshots are external and uses
the helper to fix detection of those in snapshot deletion code.

Snapshots are external if they have an external memory image or if the
disk locations are external. As mixed snapshots are forbidden for now
we need to check just one disk to know.
---
- Squashed the patch adding the helper with the actual fix.
- Fixed detection of external snapshots
---
 src/conf/snapshot_conf.c | 17 +++++++++++++++++
 src/conf/snapshot_conf.h |  2 ++
 src/libvirt_private.syms |  1 +
 src/qemu/qemu_driver.c   |  6 +++---
 4 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/src/conf/snapshot_conf.c b/src/conf/snapshot_conf.c
index 691950a..aa2b526 100644
--- a/src/conf/snapshot_conf.c
+++ b/src/conf/snapshot_conf.c
@@ -1023,3 +1023,20 @@ cleanup:
     }
     return ret;
 }
+
+
+bool
+virDomainSnapshotIsExternal(virDomainSnapshotObjPtr snap)
+{
+    int i;
+
+    if (snap->def->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL)
+        return true;
+
+    for (i = 0; i < snap->def->ndisks; i++) {
+        if (snap->def->disks[i].snapshot == VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL)
+            return true;
+    }
+
+    return false;
+}
diff --git a/src/conf/snapshot_conf.h b/src/conf/snapshot_conf.h
index 00775ae..b5c6e25 100644
--- a/src/conf/snapshot_conf.h
+++ b/src/conf/snapshot_conf.h
@@ -155,6 +155,8 @@ int virDomainListSnapshots(virDomainSnapshotObjListPtr snapshots,
                            virDomainSnapshotPtr **snaps,
                            unsigned int flags);

+bool virDomainSnapshotIsExternal(virDomainSnapshotObjPtr snap);
+
 VIR_ENUM_DECL(virDomainSnapshotLocation)
 VIR_ENUM_DECL(virDomainSnapshotState)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index e94b478..5a07139 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1083,6 +1083,7 @@ virDomainSnapshotFindByName;
 virDomainSnapshotForEach;
 virDomainSnapshotForEachChild;
 virDomainSnapshotForEachDescendant;
+virDomainSnapshotIsExternal;
 virDomainSnapshotLocationTypeFromString;
 virDomainSnapshotLocationTypeToString;
 virDomainSnapshotObjListGetNames;
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 2ddf63a..c33080d 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -2025,7 +2025,7 @@ cleanup:
 }


-/* Count how many snapshots in a set have external disk snapshots.  */
+/* Count how many snapshots in a set are external snapshots or checkpoints.  */
 static void
 qemuDomainSnapshotCountExternal(void *payload,
                                 const void *name ATTRIBUTE_UNUSED,
@@ -2034,7 +2034,7 @@ qemuDomainSnapshotCountExternal(void *payload,
     virDomainSnapshotObjPtr snap = payload;
     int *count = data;

-    if (snap->def->state == VIR_DOMAIN_DISK_SNAPSHOT)
+    if (virDomainSnapshotIsExternal(snap))
         (*count)++;
 }

@@ -12531,7 +12531,7 @@ static int qemuDomainSnapshotDelete(virDomainSnapshotPtr snapshot,

     if (!(flags & VIR_DOMAIN_SNAPSHOT_DELETE_METADATA_ONLY)) {
         if (!(flags & VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN_ONLY) &&
-            snap->def->state == VIR_DOMAIN_DISK_SNAPSHOT)
+            virDomainSnapshotIsExternal(snap))
             external++;
         if (flags & VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN)
             virDomainSnapshotForEachDescendant(snap,
-- 
1.8.0