Devices will call this function to start an asynchronous cancellation. The
bus->info->cancel will be called after the request is canceled.
Devices will probably need to track a separate TMF request that triggers this
cancellation, and wait until the cancellation is done before completing it. So
we store a notifier list in SCSIRequest and in scsi_req_canceled we notify them.
Signed-off-by: Fam Zheng <f...@redhat.com>
---
hw/scsi/scsi-bus.c | 31 ++++++++++++++++++++++++++++---
include/hw/scsi/scsi.h | 3 +++
2 files changed, 31 insertions(+), 3 deletions(-)
diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index fca4a9e..c1b05a1 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -553,9 +553,10 @@ SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops,
SCSIDevice *d,
BusState *qbus = BUS(bus);
const int memset_off = offsetof(SCSIRequest, sense)
+ sizeof(req->sense);
+ size_t reqops_size = reqops ? reqops->size : sizeof(SCSIRequest);
- req = g_slice_alloc(reqops->size);
- memset((uint8_t *)req + memset_off, 0, reqops->size - memset_off);
+ req = g_slice_alloc(reqops_size);
+ memset((uint8_t *)req + memset_off, 0, reqops_size - memset_off);
req->refcount = 1;
req->bus = bus;
req->dev = d;
@@ -566,6 +567,7 @@ SCSIRequest *scsi_req_alloc(const SCSIReqOps *reqops,
SCSIDevice *d,
req->ops = reqops;
object_ref(OBJECT(d));
object_ref(OBJECT(qbus->parent));
+ notifier_list_init(&req->cancel_notifiers);
trace_scsi_req_alloc(req->dev->id, req->lun, req->tag);
return req;
}
@@ -1600,7 +1602,7 @@ void scsi_req_unref(SCSIRequest *req)
if (bus->info->free_request && req->hba_private) {
bus->info->free_request(bus, req->hba_private);
}
- if (req->ops->free_req) {
+ if (req->ops && req->ops->free_req) {
req->ops->free_req(req);
}
object_unref(OBJECT(req->dev));
@@ -1725,9 +1727,32 @@ void scsi_req_canceled(SCSIRequest *req)
if (req->bus->info->cancel) {
req->bus->info->cancel(req);
}
+ notifier_list_notify(&req->cancel_notifiers, req);
scsi_req_unref(req);
}
+/* Cancel @req asynchronously.
+ * @tmf_req is added to @req's cancellation dependency list, the bus will be
+ * notified with @tmf_req when all the requests it depends on are canceled.
+ *
+ * @red: The request to cancel.
+ * @tmf_req: The tmf request which cancels @req.
+ * */
+void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)
+{
+ trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
+ notifier_list_add(&req->cancel_notifiers, notifier);
+ if (req->io_canceled) {
+ return;
+ }
+ scsi_req_ref(req);
+ scsi_req_dequeue(req);
+ req->io_canceled = true;
+ if (req->aiocb) {
+ bdrv_aio_cancel_async(req->aiocb);
+ }
+}
+
void scsi_req_cancel(SCSIRequest *req)
{
trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);
diff --git a/include/hw/scsi/scsi.h b/include/hw/scsi/scsi.h
index 0fa2a8a..6a051df 100644
--- a/include/hw/scsi/scsi.h
+++ b/include/hw/scsi/scsi.h
@@ -5,6 +5,7 @@
#include "block/block.h"
#include "hw/block/block.h"
#include "sysemu/sysemu.h"
+#include "qemu/notify.h"
#define MAX_SCSI_DEVS 255
@@ -53,6 +54,7 @@ struct SCSIRequest {
void *hba_private;
size_t resid;
SCSICommand cmd;
+ NotifierList cancel_notifiers;
/* Note:
* - fields before sense are initialized by scsi_req_alloc;
@@ -267,6 +269,7 @@ int scsi_req_get_sense(SCSIRequest *req, uint8_t *buf, int
len);
void scsi_req_abort(SCSIRequest *req, int status);
void scsi_req_canceled(SCSIRequest *req);
void scsi_req_cancel(SCSIRequest *req);
+void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier);
void scsi_req_retry(SCSIRequest *req);
void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense);
void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense);
--
1.9.3
