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virtio-scsi: Handle TMF request cancellation asynchronously

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For VIRTIO_SCSI_T_TMF_ABORT_TASK and VIRTIO_SCSI_T_TMF_ABORT_TASK_SET,
use scsi_req_cancel_async to start the cancellation.

Because each tmf command may cancel multiple requests, we need to use a
counter to track the number of remaining requests we still need to wait
for.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Fam Zheng 2014-09-30 11:40:23 +08:00 committed by Paolo Bonzini
parent 8e0a9320e9
commit 49e7e31aa0
2 changed files with 64 additions and 9 deletions
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64
hw/scsi/virtio-scsi.c
View File

@ -208,12 +208,33 @@ static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq)
return req;
}
static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
typedef struct {
Notifier notifier;
VirtIOSCSIReq *tmf_req;
} VirtIOSCSICancelNotifier;
static void virtio_scsi_cancel_notify(Notifier *notifier, void *data)
{
VirtIOSCSICancelNotifier *n = container_of(notifier,
VirtIOSCSICancelNotifier,
notifier);
if (--n->tmf_req->remaining == 0) {
virtio_scsi_complete_req(n->tmf_req);
}
g_slice_free(VirtIOSCSICancelNotifier, n);
}
/* Return 0 if the request is ready to be completed and return to guest;
* -EINPROGRESS if the request is submitted and will be completed later, in the
* case of async cancellation. */
static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
SCSIRequest *r, *next;
BusChild *kid;
int target;
int ret = 0;
if (s->dataplane_started && bdrv_get_aio_context(d->conf.bs) != s->ctx) {
aio_context_acquire(s->ctx);
@ -251,7 +272,14 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
*/
req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
} else {
scsi_req_cancel(r);
VirtIOSCSICancelNotifier *notifier;
req->remaining = 1;
notifier = g_slice_new(VirtIOSCSICancelNotifier);
notifier->tmf_req = req;
notifier->notifier.notify = virtio_scsi_cancel_notify;
scsi_req_cancel_async(r, &notifier->notifier);
ret = -EINPROGRESS;
}
}
break;
@ -277,6 +305,13 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) {
goto incorrect_lun;
}
/* Add 1 to "remaining" until virtio_scsi_do_tmf returns.
* This way, if the bus starts calling back to the notifiers
* even before we finish the loop, virtio_scsi_cancel_notify
* will not complete the TMF too early.
*/
req->remaining = 1;
QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) {
if (r->hba_private) {
if (req->req.tmf.subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET) {
@ -286,10 +321,19 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
req->resp.tmf.response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
break;
} else {
scsi_req_cancel(r);
VirtIOSCSICancelNotifier *notifier;
req->remaining++;
notifier = g_slice_new(VirtIOSCSICancelNotifier);
notifier->notifier.notify = virtio_scsi_cancel_notify;
notifier->tmf_req = req;
scsi_req_cancel_async(r, &notifier->notifier);
}
}
}
if (--req->remaining > 0) {
ret = -EINPROGRESS;
}
break;
case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET:
@ -310,20 +354,22 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
break;
}
return;
return ret;
incorrect_lun:
req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
return;
return ret;
fail:
req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
return ret;
}
void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
VirtIODevice *vdev = (VirtIODevice *)s;
int type;
int r = 0;
if (iov_to_buf(req->elem.out_sg, req->elem.out_num, 0,
&type, sizeof(type)) < sizeof(type)) {
@ -337,7 +383,7 @@ void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
sizeof(VirtIOSCSICtrlTMFResp)) < 0) {
virtio_scsi_bad_req();
} else {
virtio_scsi_do_tmf(s, req);
r = virtio_scsi_do_tmf(s, req);
}
} else if (req->req.tmf.type == VIRTIO_SCSI_T_AN_QUERY ||
@ -350,7 +396,11 @@ void virtio_scsi_handle_ctrl_req(VirtIOSCSI *s, VirtIOSCSIReq *req)
req->resp.an.response = VIRTIO_SCSI_S_OK;
}
}
virtio_scsi_complete_req(req);
if (r == 0) {
virtio_scsi_complete_req(req);
} else {
assert(r == -EINPROGRESS);
}
}
static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)

9
include/hw/virtio/virtio-scsi.h
View File

@ -214,8 +214,13 @@ typedef struct VirtIOSCSIReq {
/* Set by dataplane code. */
VirtIOSCSIVring *vring;
/* Used for two-stage request submission */
QTAILQ_ENTRY(VirtIOSCSIReq) next;
union {
/* Used for two-stage request submission */
QTAILQ_ENTRY(VirtIOSCSIReq) next;
/* Used for cancellation of request during TMFs */
int remaining;
};
SCSIRequest *sreq;
size_t resp_size;