From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46283) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XY3b8-0007Pn-0v for qemu-devel@nongnu.org; Sat, 27 Sep 2014 21:48:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XY3az-0001ZZ-1E for qemu-devel@nongnu.org; Sat, 27 Sep 2014 21:48:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7322) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XY3ay-0001Ys-PI for qemu-devel@nongnu.org; Sat, 27 Sep 2014 21:48:16 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s8S1mBwl009081 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Sat, 27 Sep 2014 21:48:11 -0400 From: Fam Zheng Date: Sun, 28 Sep 2014 09:48:01 +0800 Message-Id: <1411868881-19110-8-git-send-email-famz@redhat.com> In-Reply-To: <1411868881-19110-1-git-send-email-famz@redhat.com> References: <1411868881-19110-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH v4 7/7] virtio-scsi: Handle TMF request cancellation asynchronously List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini 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 --- hw/scsi/virtio-scsi.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 78 insertions(+), 7 deletions(-) diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c index fa36e23..7a6b71a 100644 --- a/hw/scsi/virtio-scsi.c +++ b/hw/scsi/virtio-scsi.c @@ -208,12 +208,40 @@ static void *virtio_scsi_load_request(QEMUFile *f, SCSIRequest *sreq) return req; } -static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req) +typedef struct { + VirtIOSCSIReq *tmf_req; + int remaining; +} VirtIOSCSICancelTracker; + +typedef struct { + Notifier notifier; + VirtIOSCSICancelTracker *tracker; +} VirtIOSCSICancelNotifier; + +static void virtio_scsi_cancel_notify(Notifier *notifier, void *data) +{ + VirtIOSCSICancelNotifier *n = container_of(notifier, + VirtIOSCSICancelNotifier, + notifier); + + if (--n->tracker->remaining == 0) { + virtio_scsi_complete_req(n->tracker->tmf_req); + g_slice_free(VirtIOSCSICancelTracker, n->tracker); + } + 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; + int cancel_count; if (s->dataplane_started && bdrv_get_aio_context(d->conf.bs) != s->ctx) { aio_context_acquire(s->ctx); @@ -251,7 +279,18 @@ 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; + VirtIOSCSICancelTracker *tracker; + + notifier = g_slice_new(VirtIOSCSICancelNotifier); + notifier->notifier.notify + = virtio_scsi_cancel_notify; + tracker = g_slice_new(VirtIOSCSICancelTracker); + tracker->tmf_req = req; + tracker->remaining = 1; + notifier->tracker = tracker; + scsi_req_cancel_async(r, ¬ifier->notifier); + ret = -EINPROGRESS; } } break; @@ -277,6 +316,7 @@ static void virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req) if (d->lun != virtio_scsi_get_lun(req->req.tmf.lun)) { goto incorrect_lun; } + cancel_count = 0; 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 +326,35 @@ 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); + /* Before we actually cancel any requests in the next for + * loop, let's count them. This way, if the bus starts + * calling back to the notifier even before we finish the + * loop, the counter, which value is already seen in + * virtio_scsi_cancel_notify, will prevent us from + * completing the tmf too quickly. */ + cancel_count++; } } } + if (cancel_count) { + VirtIOSCSICancelNotifier *notifier; + VirtIOSCSICancelTracker *tracker; + + tracker = g_slice_new(VirtIOSCSICancelTracker); + tracker->tmf_req = req; + tracker->remaining = cancel_count; + + QTAILQ_FOREACH_SAFE(r, &d->requests, next, next) { + if (r->hba_private) { + notifier = g_slice_new(VirtIOSCSICancelNotifier); + notifier->notifier.notify = virtio_scsi_cancel_notify; + notifier->tracker = tracker; + scsi_req_cancel_async(r, ¬ifier->notifier); + } + } + ret = -EINPROGRESS; + } + break; case VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET: @@ -310,20 +375,22 @@ 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 +404,7 @@ 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 +417,11 @@ 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) -- 1.9.3