scsi: Introduce scsi_req_cancel_complete

Let the aio cb do the clean up and notification job after scsi_req_cancel, in
preparation for asynchronous cancellation.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/scsi/scsi-bus.c

@@ -1718,6 +1718,16 @@ void scsi_req_complete(SCSIRequest *req, int status)
     scsi_req_unref(req);
 }
 
+/* Called by the devices when the request is canceled. */
+void scsi_req_cancel_complete(SCSIRequest *req)
+{
+    assert(req->io_canceled);
+    if (req->bus->info->cancel) {
+        req->bus->info->cancel(req);
+    }
+    scsi_req_unref(req);
+}
+
 void scsi_req_cancel(SCSIRequest *req)
 {
     trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
@@ -1730,10 +1740,6 @@ void scsi_req_cancel(SCSIRequest *req)
     if (req->aiocb) {
         bdrv_aio_cancel(req->aiocb);
     }
-    if (req->bus->info->cancel) {
-        req->bus->info->cancel(req);
-    }
-    scsi_req_unref(req);
 }
 
 static int scsi_ua_precedence(SCSISense sense)

hw/scsi/scsi-disk.c

@@ -168,6 +168,7 @@ static void scsi_aio_complete(void *opaque, int ret)
     r->req.aiocb = NULL;
     block_acct_done(bdrv_get_stats(s->qdev.conf.bs), &r->acct);
     if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
         goto done;
     }
 
@@ -214,6 +215,7 @@ static void scsi_write_do_fua(SCSIDiskReq *r)
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev);
 
     if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
         goto done;
     }
 
@@ -240,6 +242,7 @@ static void scsi_dma_complete_noio(void *opaque, int ret)
         block_acct_done(bdrv_get_stats(s->qdev.conf.bs), &r->acct);
     }
     if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
         goto done;
     }
 
@@ -280,6 +283,7 @@ static void scsi_read_complete(void * opaque, int ret)
     r->req.aiocb = NULL;
     block_acct_done(bdrv_get_stats(s->qdev.conf.bs), &r->acct);
     if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
         goto done;
     }
 
@@ -312,6 +316,7 @@ static void scsi_do_read(void *opaque, int ret)
         block_acct_done(bdrv_get_stats(s->qdev.conf.bs), &r->acct);
     }
     if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
         goto done;
     }
 
@@ -432,6 +437,7 @@ static void scsi_write_complete(void * opaque, int ret)
         block_acct_done(bdrv_get_stats(s->qdev.conf.bs), &r->acct);
     }
     if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
         goto done;
     }
 
@@ -1524,6 +1530,7 @@ static void scsi_unmap_complete(void *opaque, int ret)
 
     r->req.aiocb = NULL;
     if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
         goto done;
     }
 
@@ -1623,6 +1630,7 @@ static void scsi_write_same_complete(void *opaque, int ret)
     r->req.aiocb = NULL;
     block_acct_done(bdrv_get_stats(s->qdev.conf.bs), &r->acct);
     if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
         goto done;
     }
 

hw/scsi/scsi-generic.c

@@ -94,6 +94,7 @@ static void scsi_command_complete(void *opaque, int ret)
 
     r->req.aiocb = NULL;
     if (r->req.io_canceled) {
+        scsi_req_cancel_complete(&r->req);
         goto done;
     }
     if (r->io_header.driver_status & SG_ERR_DRIVER_SENSE) {

include/hw/scsi/scsi.h

@@ -264,6 +264,7 @@ void scsi_req_data(SCSIRequest *req, int len);
 void scsi_req_complete(SCSIRequest *req, int status);
 uint8_t *scsi_req_get_buf(SCSIRequest *req);
 int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int len);
+void scsi_req_cancel_complete(SCSIRequest *req);
 void scsi_req_cancel(SCSIRequest *req);
 void scsi_req_retry(SCSIRequest *req);
 void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense);