[libvirt] [PATCH v2 1/5] snapshot: define new API virDomainSnapshotDeleteByName

[Guannan Ren]

This is to delete a snapshot object atomically, the API accepts
argments: domain object, snapshot name and flags. When name is
NULL, the current snapshot object will be deleted

include/libvirt/libvirt.h.in: Declare virDomainSnapshotDeleteByName
src/driver.h: (virDrvDomainSnapshotDeleteByName)
src/libvirt.c: Implement the public API
src/libvirt_public.syms: Export the symbol to public
---
 include/libvirt/libvirt.h.in |  4 +++
 src/driver.h                 |  6 ++++
 src/libvirt.c                | 71 ++++++++++++++++++++++++++++++++++++++++++++
 src/libvirt_public.syms      |  5 ++++
 4 files changed, 86 insertions(+)

diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index b791125..e7e75c0 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -4433,6 +4433,10 @@ typedef enum {
 int virDomainSnapshotDelete(virDomainSnapshotPtr snapshot,
                             unsigned int flags);
 
+int virDomainSnapshotDeleteByName(virDomainPtr domain,
+                                  const char *name,
+                                  unsigned int flags);
+
 int virDomainSnapshotRef(virDomainSnapshotPtr snapshot);
 int virDomainSnapshotFree(virDomainSnapshotPtr snapshot);
 
diff --git a/src/driver.h b/src/driver.h
index 31851cb..8651603 100644
--- a/src/driver.h
+++ b/src/driver.h
@@ -801,6 +801,11 @@ typedef int
                               unsigned int flags);
 
 typedef int
+(*virDrvDomainSnapshotDeleteByName)(virDomainPtr domain,
+                                    const char *cmd,
+                                    unsigned int flags);
+
+typedef int
 (*virDrvDomainQemuMonitorCommand)(virDomainPtr domain,
                                   const char *cmd,
                                   char **result,
@@ -1272,6 +1277,7 @@ struct _virDriver {
     virDrvDomainSnapshotHasMetadata domainSnapshotHasMetadata;
     virDrvDomainRevertToSnapshot domainRevertToSnapshot;
     virDrvDomainSnapshotDelete domainSnapshotDelete;
+    virDrvDomainSnapshotDeleteByName domainSnapshotDeleteByName;
     virDrvDomainQemuMonitorCommand domainQemuMonitorCommand;
     virDrvDomainQemuAttach domainQemuAttach;
     virDrvDomainQemuAgentCommand domainQemuAgentCommand;
diff --git a/src/libvirt.c b/src/libvirt.c
index bc1694a..aa04959 100644
--- a/src/libvirt.c
+++ b/src/libvirt.c
@@ -20158,6 +20158,10 @@ error:
  * libvirt metadata to track snapshots, then this flag is silently
  * ignored.
  *
+ * Note that this command is inherently racy: another connection can
+ * delete the snapshot object between a call to virDomainSnapshotLookupByName()
+ * and this call.
+ *
  * Returns 0 if the selected snapshot(s) were successfully deleted,
  * -1 on error.
  */
@@ -20207,6 +20211,73 @@ error:
 }
 
 /**
+ * virDomainSnapshotDeleteByName:
+ * @domain: pointer to the domain object
+ * @name : snapshot name or NULL
+ * @flags: bitwise-OR of supported virDomainSnapshotDeleteFlags
+ *
+ * Delete the snapshot.
+ *
+ * If @flags is 0, then just this snapshot is deleted, and changes
+ * from this snapshot are automatically merged into children
+ * snapshots.  If @flags includes VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN,
+ * then this snapshot and any descendant snapshots are deleted.  If
+ * @flags includes VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN_ONLY, then any
+ * descendant snapshots are deleted, but this snapshot remains.  These
+ * two flags are mutually exclusive.
+ *
+ * If @flags includes VIR_DOMAIN_SNAPSHOT_DELETE_METADATA_ONLY, then
+ * any snapshot metadata tracked by libvirt is removed while keeping
+ * the snapshot contents intact; if a hypervisor does not require any
+ * libvirt metadata to track snapshots, then this flag is silently
+ * ignored.
+ *
+ * Returns 0 if the selected snapshot(s) were successfully deleted,
+ * -1 on error.
+ */
+int
+virDomainSnapshotDeleteByName(virDomainPtr domain,
+                              const char *name,
+                              unsigned int flags)
+{
+    VIR_DOMAIN_DEBUG(domain, "name=%s, flags=%x", name, flags);
+
+    virResetLastError();
+
+    if (!VIR_IS_DOMAIN(domain)) {
+        virLibDomainError(VIR_ERR_INVALID_DOMAIN, __FUNCTION__);
+        virDispatchError(NULL);
+        return -1;
+    }
+
+    if (domain->conn->flags & VIR_CONNECT_RO) {
+        virLibConnError(VIR_ERR_OPERATION_DENIED, __FUNCTION__);
+        goto error;
+    }
+
+    if ((flags & VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN) &&
+        (flags & VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN_ONLY)) {
+        virReportInvalidArg(flags,
+                            _("children and children_only flags in %s are "
+                              "mutually exclusive"),
+                            __FUNCTION__);
+        goto error;
+    }
+
+    if (domain->conn->driver->domainSnapshotDelete) {
+        int ret = domain->conn->driver->domainSnapshotDeleteByName(domain, name, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virLibConnError(VIR_ERR_NO_SUPPORT, __FUNCTION__);
+error:
+    virDispatchError(domain->conn);
+    return -1;
+}
+
+/**
  * virDomainSnapshotRef:
  * @snapshot: the snapshot to hold a reference on
  *
diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms
index 7c6edf6..24826b8 100644
--- a/src/libvirt_public.syms
+++ b/src/libvirt_public.syms
@@ -627,4 +627,9 @@ LIBVIRT_1.1.0 {
         virDomainMigrateToURI3;
 } LIBVIRT_1.0.6;
 
+LIBVIRT_1.1.1 {
+    global:
+        virDomainSnapshotDeleteByName;
+}LIBVIRT_1.1.0;
+
 # .... define new API here using predicted next version number ....
-- 
1.8.1.4