Re: [libvirt PATCH 14/20] qemu_snapshot: add support to delete external snapshot without block commit

4 Apr 2023

On Mon, Mar 13, 2023 at 16:42:15 +0100, Pavel Hrdina wrote:
...
When block commit is not needed we can just simply unlink the
disk files.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
---
 src/qemu/qemu_snapshot.c | 55 +++++++++++++++++++++++++---------------
 1 file changed, 35 insertions(+), 20 deletions(-)

diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index be2e5c8cc4..dbcdf56758 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
[...]
...
@@ -2949,31 +2951,41 @@ qemuSnapshotDiscardExternal(virDomainObj *vm,
         virTristateBool autofinalize = VIR_TRISTATE_BOOL_NO;
         unsigned int commitFlags = VIR_DOMAIN_BLOCK_COMMIT_DELETE;
-        if (data->domDisk->src == data->diskSrc) {
-            commitFlags |= VIR_DOMAIN_BLOCK_COMMIT_ACTIVE;
-            autofinalize = VIR_TRISTATE_BOOL_YES;
+        if (data->blockCommit) {
+            if (data->domDisk->src == data->diskSrc) {
+                commitFlags |= VIR_DOMAIN_BLOCK_COMMIT_ACTIVE;
+                autofinalize = VIR_TRISTATE_BOOL_YES;
+            }
+
+            if (qemuSnapshotSetInvalid(vm, data->parentSnap, data->snapDisk, true) < 0)
+                goto error;
+
+            data->job = qemuBlockCommit(vm,
+                                        data->domDisk,
+                                        data->parentDiskSrc,
+                                        data->diskSrc,
+                                        data->prevDiskSrc,
+                                        0,
+                                        VIR_ASYNC_JOB_SNAPSHOT,
+                                        autofinalize,
+                                        commitFlags);
+
+            if (!data->job)
+                goto error;
+        } else {
+            if (unlink(data->snapDisk->src->path) < 0) {
This can be done only when the 'src' object is "local storage"
(virStorageSourceIsLocalStorage)
...
+                VIR_WARN("Failed to remove snapshot image '%s'",
+                         data->snapDisk->name);
+            }
Reviewed-by: Peter Krempa <pkrempa@redhat.com>

    