Commit 8e0a9320 authored by Fam Zheng's avatar Fam Zheng Committed by Paolo Bonzini
Browse files

scsi: Introduce scsi_req_cancel_async 



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_cancel_complete we
notify them.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent d5776465

hw/scsi/scsi-bus.c

+26 −0
Original line number Diff line number Diff line
@@ -566,6 +566,7 @@ 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;

}
@@ -1715,6 +1716,9 @@ void scsi_req_complete(SCSIRequest *req, int status) 
    scsi_req_ref(req);

    scsi_req_dequeue(req);

    req->bus->info->complete(req, req->status, req->resid);



    /* Cancelled requests might end up being completed instead of cancelled */

    notifier_list_notify(&req->cancel_notifiers, req);

    scsi_req_unref(req);

}
@@ -1725,9 +1729,31 @@ void scsi_req_cancel_complete(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. @notifier is added to @req's cancellation

 * notifier list, the bus will be notified the requests cancellation is

 * completed.

 * */

void scsi_req_cancel_async(SCSIRequest *req, Notifier *notifier)

{

    trace_scsi_req_cancel(req->dev->id, req->lun, req->tag);

    if (notifier) {

        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);

include/hw/scsi/scsi.h

+3 −0
Original line number Diff line number Diff line
@@ -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;
@@ -266,6 +268,7 @@ 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_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);