blockdev: add Abort transaction

The Abort action can be used to test QMP 'transaction' failure.  Add it
as the last action to exercise the .abort() and .cleanup() code paths
for all previous actions.

Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

2 files changed, 27 insertions, 1 deletions

diff --git a/blockdev.c b/blockdev.c
index 6200c0d..b3a57e0 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -963,6 +963,16 @@ static void drive_backup_abort(BlkTransactionState *common)
     }
 }
 
+static void abort_prepare(BlkTransactionState *common, Error **errp)
+{
+    error_setg(errp, "Transaction aborted using Abort action");
+}
+
+static void abort_commit(BlkTransactionState *common)
+{
+    assert(false); /* this action never succeeds */
+}
+
 static const BdrvActionOps actions[] = {
     [TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT_SYNC] = {
         .instance_size = sizeof(ExternalSnapshotState),
@@ -975,6 +985,11 @@ static const BdrvActionOps actions[] = {
         .prepare = drive_backup_prepare,
         .abort = drive_backup_abort,
     },
+    [TRANSACTION_ACTION_KIND_ABORT] = {
+        .instance_size = sizeof(BlkTransactionState),
+        .prepare = abort_prepare,
+        .commit = abort_commit,
+    },
 };
 
 /*
diff --git a/qapi-schema.json b/qapi-schema.json
index 714108d..6590307 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1660,6 +1660,16 @@
             '*on-target-error': 'BlockdevOnError' } }
 
 ##
+# @Abort
+#
+# This action can be used to test transaction failure.
+#
+# Since: 1.6
+###
+{ 'type': 'Abort',
+  'data': { } }
+
+##
 # @TransactionAction
 #
 # A discriminated record of operations that can be performed with
@@ -1668,7 +1678,8 @@
 { 'union': 'TransactionAction',
   'data': {
        'blockdev-snapshot-sync': 'BlockdevSnapshot',
-       'drive-backup': 'DriveBackup'
+       'drive-backup': 'DriveBackup',
+       'abort': 'Abort'
    } }
 
 ##