[PULL,18/33] qmp: add interface blockdev-snapshot-delete-internal-sync

diff --git a/blockdev.c b/blockdev.c
index 0f4a7b5..84d55c1 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -871,6 +871,67 @@  void qmp_blockdev_snapshot_internal_sync(const char *device,
                        &snapshot, errp);
 }
 
+SnapshotInfo *qmp_blockdev_snapshot_delete_internal_sync(const char *device,
+                                                         bool has_id,
+                                                         const char *id,
+                                                         bool has_name,
+                                                         const char *name,
+                                                         Error **errp)
+{
+    BlockDriverState *bs = bdrv_find(device);
+    QEMUSnapshotInfo sn;
+    Error *local_err = NULL;
+    SnapshotInfo *info = NULL;
+    int ret;
+
+    if (!bs) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+        return NULL;
+    }
+
+    if (!has_id) {
+        id = NULL;
+    }
+
+    if (!has_name) {
+        name = NULL;
+    }
+
+    if (!id && !name) {
+        error_setg(errp, "Name or id must be provided");
+        return NULL;
+    }
+
+    ret = bdrv_snapshot_find_by_id_and_name(bs, id, name, &sn, &local_err);
+    if (error_is_set(&local_err)) {
+        error_propagate(errp, local_err);
+        return NULL;
+    }
+    if (!ret) {
+        error_setg(errp,
+                   "Snapshot with id '%s' and name '%s' does not exist on "
+                   "device '%s'",
+                   STR_OR_NULL(id), STR_OR_NULL(name), device);
+        return NULL;
+    }
+
+    bdrv_snapshot_delete(bs, id, name, &local_err);
+    if (error_is_set(&local_err)) {
+        error_propagate(errp, local_err);
+        return NULL;
+    }
+
+    info = g_malloc0(sizeof(SnapshotInfo));
+    info->id = g_strdup(sn.id_str);
+    info->name = g_strdup(sn.name);
+    info->date_nsec = sn.date_nsec;
+    info->date_sec = sn.date_sec;
+    info->vm_state_size = sn.vm_state_size;
+    info->vm_clock_nsec = sn.vm_clock_nsec % 1000000000;
+    info->vm_clock_sec = sn.vm_clock_nsec / 1000000000;
+
+    return info;
+}
 
 /* New and old BlockDriverState structs for group snapshots */
 
diff --git a/include/qemu-common.h b/include/qemu-common.h
index 6948bb9..5054836 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -191,6 +191,9 @@  int64_t strtosz_suffix(const char *nptr, char **end, const char default_suffix);
 int64_t strtosz_suffix_unit(const char *nptr, char **end,
                             const char default_suffix, int64_t unit);
 
+/* used to print char* safely */
+#define STR_OR_NULL(str) ((str) ? (str) : "null")
+
 /* path.c */
 void init_paths(const char *prefix);
 const char *path(const char *pathname);
diff --git a/qapi-schema.json b/qapi-schema.json
index 43faf91..145eca8 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1825,6 +1825,33 @@ 
   'data': 'BlockdevSnapshotInternal' }
 
 ##
+# @blockdev-snapshot-delete-internal-sync
+#
+# Synchronously delete an internal snapshot of a block device, when the format
+# of the image used support it. The snapshot is identified by name or id or
+# both. One of the name or id is required. Return SnapshotInfo for the
+# successfully deleted snapshot.
+#
+# @device: the name of the device to delete the snapshot from
+#
+# @id: optional the snapshot's ID to be deleted
+#
+# @name: optional the snapshot's name to be deleted
+#
+# Returns: SnapshotInfo on success
+#          If @device is not a valid block device, DeviceNotFound
+#          If snapshot not found, GenericError
+#          If the format of the image used does not support it,
+#          BlockFormatFeatureNotSupported
+#          If @id and @name are both not specified, GenericError
+#
+# Since 1.7
+##
+{ 'command': 'blockdev-snapshot-delete-internal-sync',
+  'data': { 'device': 'str', '*id': 'str', '*name': 'str'},
+  'returns': 'SnapshotInfo' }
+
+##
 # @human-monitor-command:
 #
 # Execute a command on the human monitor and return the output.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 5c9ddef..b17c46e 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1127,6 +1127,47 @@  Example:
 EQMP
 
     {
+        .name       = "blockdev-snapshot-delete-internal-sync",
+        .args_type  = "device:B,id:s?,name:s?",
+        .mhandler.cmd_new =
+                      qmp_marshal_input_blockdev_snapshot_delete_internal_sync,
+    },
+
+SQMP
+blockdev-snapshot-delete-internal-sync
+--------------------------------------
+
+Synchronously delete an internal snapshot of a block device when the format of
+image used supports it.  The snapshot is identified by name or id or both.  One
+of name or id is required.  If the snapshot is not found, the operation will
+fail.
+
+Arguments:
+
+- "device": device name (json-string)
+- "id": ID of the snapshot (json-string, optional)
+- "name": name of the snapshot (json-string, optional)
+
+Example:
+
+-> { "execute": "blockdev-snapshot-delete-internal-sync",
+                "arguments": { "device": "ide-hd0",
+                               "name": "snapshot0" }
+   }
+<- { "return": {
+                   "id": "1",
+                   "name": "snapshot0",
+                   "vm-state-size": 0,
+                   "date-sec": 1000012,
+                   "date-nsec": 10,
+                   "vm-clock-sec": 100,
+                   "vm-clock-nsec": 20
+     }
+   }
+
+EQMP
+
+    {
         .name       = "drive-mirror",
         .args_type  = "sync:s,device:B,target:s,speed:i?,mode:s?,format:s?,"
                       "on-source-error:s?,on-target-error:s?,"