[Qemu-devel] [PATCH V2 08/10] snapshot: qmp add internal snapshot transaction interface

[Wenchao Xia]

  Now qmp_transaction support creating internal snapshot.

Signed-off-by: Wenchao Xia <address@hidden>
---
 blockdev.c       |   46 ++++++++++++++++++++++++++++++++++++++++++++++
 qapi-schema.json |   29 +++++++++++++++++++++++++++++
 qmp-commands.hx  |   24 +++++++++++++++++-------
 3 files changed, 92 insertions(+), 7 deletions(-)

diff --git a/blockdev.c b/blockdev.c
index 299039f..09eeb7f 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1218,6 +1218,41 @@ static int fill_blk_trs_ext_create_sync(BlockdevSnapshot 
*create_sync,
     return 0;
 }
 
+static int fill_blk_trs_int_create_sync(BlockdevSnapshotInternal *create_sync,
+                                        BlkTransStatesSync *st_sync,
+                                        SNTime *time,
+                                        const char *time_str,
+                                        Error **errp)
+{
+    BlockDriverState *bs;
+    const char *device = create_sync->device;
+    const char *name = NULL;
+
+    if (create_sync->has_name) {
+        name = create_sync->name;
+    }
+
+    /* find the target bs */
+    bs = bdrv_find(device);
+    if (!bs) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+        return -1;
+    }
+
+    st_sync->use_existing = false;
+
+    /* internal case, if caller need create new one with default string */
+    if (name == NULL) {
+        st_sync->internal.sn_name = time_str;
+    } else {
+        st_sync->internal.sn_name = name;
+    }
+    st_sync->internal.bs = bs;
+    st_sync->internal.time = *time;
+
+    return 0;
+}
+
 static int fill_blk_trs(BlockdevAction *dev_info,
                         BlkTransStates *states,
                         SNTime *time,
@@ -1234,6 +1269,17 @@ static int fill_blk_trs(BlockdevAction *dev_info,
                                            &states->st_sync,
                                            errp);
         break;
+    case BLOCKDEV_ACTION_KIND_BLOCKDEV_SNAPSHOT_INTERNAL_SYNC:
+        states->st_sync.type = BLK_SNAPSHOT_INTERNAL;
+        states->st_sync.op = BLK_SN_SYNC_CREATE;
+        BlockdevSnapshotInternal *create_sync;
+        create_sync = dev_info->blockdev_snapshot_internal_sync;
+        ret = fill_blk_trs_int_create_sync(create_sync,
+                                           &states->st_sync,
+                                           time,
+                                           time_str,
+                                           errp);
+        break;
     default:
         abort();
     }
diff --git a/qapi-schema.json b/qapi-schema.json
index 5dfa052..ea3ef77 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1474,6 +1474,20 @@
   'data': [ 'existing', 'absolute-paths' ] }
 
 ##
+# @NewSnapshotMode
+#
+# An enumeration that tells QEMU how to create internal snapshot.
+#
+# @existing: QEMU should look for an existing snapshot.
+#
+# @new: QEMU should create a new internal snapshot, if it exist, overwrite it.
+#
+# Since: 1.4
+##
+{ 'enum': 'NewSnapshotMode'
+  'data': [ 'existing', 'new' ] }
+
+##
 # @BlockdevSnapshot
 #
 # @device:  the name of the device to generate the snapshot from.
@@ -1490,6 +1504,20 @@
             '*mode': 'NewImageMode' } }
 
 ##
+# @BlockdevSnapshotInternal
+#
+# @device:  the name of the device to generate the snapshot from.
+#
+# @name: #optional the name of the internal snapshot to create, default is to
+#         generate it automatically according to host time. If a snapshot with
+#         name exist, it will be overwritten.
+#
+# Since: 1.4
+##
+{ 'type': 'BlockdevSnapshotInternal',
+  'data': { 'device': 'str', '*name': 'str', } }
+
+##
 # @BlockdevAction
 #
 # A discriminated record of operations that can be performed with
@@ -1498,6 +1526,7 @@
 { 'union': 'BlockdevAction',
   'data': {
        'blockdev-snapshot-sync': 'BlockdevSnapshot',
+       'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal',
    } }
 
 ##
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 5c692d0..3c2f468 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -863,10 +863,13 @@ any of the operations, all snapshots for the group are 
abandoned, and
 the original disks pre-snapshot attempt are used.
 
 A list of dictionaries is accepted, that contains the actions to be performed.
-For snapshots this is the device, the file to use for the new snapshot,
-and the format.  The default format, if not specified, is qcow2.
+For external snapshots this is the device, the file to use for the new
+snapshot, and the format.  The default format, if not specified, is qcow2.
+For internal snapshots this is the device, the snapshot name. If name is
+not specified, it would be generated automatically according to host time.
+If an internal snapshot with name exist, it will be over written.
 
-Each new snapshot defaults to being created by QEMU (wiping any
+Each new external snapshot defaults to being created by QEMU (wiping any
 contents if the file already exists), but it is also possible to reuse
 an externally-created file.  In the latter case, you should ensure that
 the new image file has the same contents as the current one; QEMU cannot
@@ -876,15 +879,20 @@ current image file as the backing file for the new image.
 Arguments:
 
 actions array:
-    - "type": the operation to perform.  The only supported
-      value is "blockdev-snapshot-sync". (json-string)
+    - "type": the operation to perform.  The supported values are
+      "blockdev-snapshot-sync" and "blockdev-snapshot-internal-sync".
+      (json-string)
     - "data": a dictionary.  The contents depend on the value
-      of "type".  When "type" is "blockdev-snapshot-sync":
+      of "type".
+      When "type" is "blockdev-snapshot-sync":
       - "device": device name to snapshot (json-string)
       - "snapshot-file": name of new image file (json-string)
       - "format": format of new image (json-string, optional)
       - "mode": whether and how QEMU should create the snapshot file
         (NewImageMode, optional, default "absolute-paths")
+      When "type" is "blockdev-snapshot-internal-sync":
+      - "device": device name to snapshot (json-string)
+      - "name": name of internal snapshot (json-string, optional)
 
 Example:
 
@@ -896,7 +904,9 @@ Example:
          { 'type': 'blockdev-snapshot-sync', 'data' : { "device": "ide-hd1",
                                          "snapshot-file": 
"/some/place/my-image2",
                                          "mode": "existing",
-                                         "format": "qcow2" } } ] } }
+                                         "format": "qcow2" } },
+         { 'type': 'blockdev-snapshot-internal-sync', 'data' : { "device": 
"ide-hd2",
+                                         "name": "snapshot0" } } ] } }
 <- { "return": {} }
 
 EQMP
-- 
1.7.1