[Qemu-devel] [RFC PATCH 3/9] iscsi: Implement .cancel_async in acb info

[Fam Zheng <famz@redhat.com>]

Factor out the cancellation submission part in iscsi_aio_cancel, which
is all what is needed for .cancel_async.

The cb passed to iscsi_task_mgmt_abort_task_async, iscsi_abort_task_cb,
will be called later, so for iscsi_bh_cb. In iscsi_bh_cb, acb->canceled
is not set if canceled by .cancel_async, so the completion cb is also
called.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/iscsi.c | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index 2c9cfc1..8b27a5c 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -121,6 +121,8 @@ iscsi_bh_cb(void *p)
     acb->buf = NULL;
 
     if (acb->canceled == 0) {
+        /* Either normally completed or cancelled by iscsi_aio_cancel_async,
+         * let's call the cb. */
         acb->common.cb(acb->common.opaque, acb->status);
     }
 
@@ -231,7 +233,7 @@ iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void *command_data,
 }
 
 static void
-iscsi_aio_cancel(BlockDriverAIOCB *blockacb)
+iscsi_aio_cancel_async(BlockDriverAIOCB *blockacb)
 {
     IscsiAIOCB *acb = (IscsiAIOCB *)blockacb;
     IscsiLun *iscsilun = acb->iscsilun;
@@ -240,12 +242,21 @@ iscsi_aio_cancel(BlockDriverAIOCB *blockacb)
         return;
     }
 
-    acb->canceled = 1;
-
     /* send a task mgmt call to the target to cancel the task on the target */
     iscsi_task_mgmt_abort_task_async(iscsilun->iscsi, acb->task,
                                      iscsi_abort_task_cb, acb);
 
+}
+
+static void
+iscsi_aio_cancel(BlockDriverAIOCB *blockacb)
+{
+    IscsiAIOCB *acb = (IscsiAIOCB *)blockacb;
+    IscsiLun *iscsilun = acb->iscsilun;
+
+    iscsi_aio_cancel_async(blockacb);
+
+    acb->canceled = 1;
     while (acb->status == -EINPROGRESS) {
         aio_poll(iscsilun->aio_context, true);
     }
@@ -254,6 +265,7 @@ iscsi_aio_cancel(BlockDriverAIOCB *blockacb)
 static const AIOCBInfo iscsi_aiocb_info = {
     .aiocb_size         = sizeof(IscsiAIOCB),
     .cancel             = iscsi_aio_cancel,
+    .cancel_async       = iscsi_aio_cancel_async,
 };
 
 
-- 
2.0.3