Il 24/09/2014 10:27, Fam Zheng ha scritto:
> 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>
There are some remnants of the old implementation. Apart from that it
looks good.
Paolo
> ---
> 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;
This is not needed anymore.
> @@ -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) {
Same here.
> 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.
@tmf_req doesn't exist anymore... :)
> + * @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);
Perhaps wrap with "if (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);
>
