Attachment 162793 Details for Bug 204298 – cam_xpt.c device callout patch

[patch] cam_xpt.c device callout patch

xpt-callout.patch (text/plain), 4.24 KB, created by Scott M. Ferris on 2015-11-05 00:34:15 UTC

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Creator: Scott M. Ferris

Created: 2015-11-05 00:34:15 UTC

Size: 4.24 KB

patch

obsolete

>diff --git i/sys/cam/cam_xpt.c w/sys/cam/cam_xpt.c
>index fb5d041..cda56e7 100644
>--- i/sys/cam/cam_xpt.c
>+++ w/sys/cam/cam_xpt.c
>@@ -2901,7 +2901,24 @@ call_sim:
> 				 */
> 				start_ccb->ccb_h.flags &= ~CAM_DEV_QFREEZE;
> 				callout_stop(&dev->callout);
>+				/*
>+				 * If CAM_DEV_REL_TIMEOUT_PENDING is still
>+				 * set, then the callout is still
>+				 * cancelable, since we hold the callout
>+				 * mutex and the callout function clears the
>+				 * flag before it ever unlocks/relocks the
>+				 * mutex.  Since we already acquired a
>+				 * device ref for the callout we just
>+				 * stopped, we don't need another ref.
>+				 */
> 			} else {
>+				/*
>+				 * Since the callout gets a pointer to the
>+				 * device, acquire a reference to make sure
>+				 * the device can't go away until the
>+				 * callout finishes or is stopped.
>+				 */
>+				xpt_acquire_device(dev);
> 
> 				start_ccb->ccb_h.flags |= CAM_DEV_QFREEZE;
> 			}
>@@ -4355,7 +4372,20 @@ xpt_release_devq_device(struct cam_ed *dev, u_int count, int run_queue)
> 		 * to release this queue.
> 		 */
> 		if ((dev->flags & CAM_DEV_REL_TIMEOUT_PENDING) != 0) {
>-			callout_stop(&dev->callout);
>+			/*
>+			 * If CAM_DEV_REL_TIMEOUT_PENDING is still set,
>+			 * either the callout is still cancelable, or the
>+			 * callout function (xpt_release_devq_timeout) is
>+			 * our caller.  It's too early for the callout
>+			 * itself to release its ref, so only release the
>+			 * device ref if we stop the callout.  If we
>+			 * can't stop the callout, it will release
>+			 * its ref when it finishes.
>+			 */
>+			if (callout_stop(&dev->callout) != 0) {
>+				/* Release the callout's device reference */
>+				xpt_release_device(dev);
>+			}
> 			dev->flags &= ~CAM_DEV_REL_TIMEOUT_PENDING;
> 		}
> 		/*
>@@ -4646,6 +4676,38 @@ static void
> xpt_destroy_device(void *context, int pending)
> {
> 	struct cam_ed	*device = context;
>+	struct cam_eb *bus = device->target->bus;
>+	struct cam_devq *devq;
>+
>+	callout_drain(&device->callout);
>+
>+	/* Release our slot in the devq */
>+	devq = bus->sim->devq;
>+	mtx_lock(&devq->send_mtx);
>+	KASSERT((device->flags & CAM_DEV_REL_TIMEOUT_PENDING) == 0,
>+	    ("device %p has timeout pending", device));
>+	cam_devq_resize(devq, devq->send_queue.array_size - 1);
>+	mtx_unlock(&devq->send_mtx);
>+
>+	KASSERT(SLIST_EMPTY(&device->periphs),
>+	    ("destroying device, but periphs list is not empty"));
>+	KASSERT(device->devq_entry.index == CAM_UNQUEUED_INDEX,
>+	    ("destroying device while still queued for ccbs"));
>+
>+	xpt_release_target(device->target);
>+
>+	cam_ccbq_fini(&device->ccbq);
>+	/*
>+	 * Free allocated memory.  free(9) does nothing if the
>+	 * supplied pointer is NULL, so it is safe to call without
>+	 * checking.
>+	 */
>+	free(device->supported_vpds, M_CAMXPT);
>+	free(device->device_id, M_CAMXPT);
>+	free(device->ext_inq, M_CAMXPT);
>+	free(device->physpath, M_CAMXPT);
>+	free(device->rcap_buf, M_CAMXPT);
>+	free(device->serial_num, M_CAMXPT);
> 
> 	mtx_lock(&device->device_mtx);
> 	mtx_destroy(&device->device_mtx);
>@@ -4723,7 +4785,6 @@ void
> xpt_release_device(struct cam_ed *device)
> {
> 	struct cam_eb *bus = device->target->bus;
>-	struct cam_devq *devq;
> 
> 	mtx_lock(&bus->eb_mtx);
> 	if (--device->refcount > 0) {
>@@ -4735,34 +4796,6 @@ xpt_release_device(struct cam_ed *device)
> 	device->target->generation++;
> 	mtx_unlock(&bus->eb_mtx);
> 
>-	/* Release our slot in the devq */
>-	devq = bus->sim->devq;
>-	mtx_lock(&devq->send_mtx);
>-	cam_devq_resize(devq, devq->send_queue.array_size - 1);
>-	mtx_unlock(&devq->send_mtx);
>-
>-	KASSERT(SLIST_EMPTY(&device->periphs),
>-	    ("destroying device, but periphs list is not empty"));
>-	KASSERT(device->devq_entry.index == CAM_UNQUEUED_INDEX,
>-	    ("destroying device while still queued for ccbs"));
>-
>-	if ((device->flags & CAM_DEV_REL_TIMEOUT_PENDING) != 0)
>-		callout_stop(&device->callout);
>-
>-	xpt_release_target(device->target);
>-
>-	cam_ccbq_fini(&device->ccbq);
>-	/*
>-	 * Free allocated memory.  free(9) does nothing if the
>-	 * supplied pointer is NULL, so it is safe to call without
>-	 * checking.
>-	 */
>-	free(device->supported_vpds, M_CAMXPT);
>-	free(device->device_id, M_CAMXPT);
>-	free(device->ext_inq, M_CAMXPT);
>-	free(device->physpath, M_CAMXPT);
>-	free(device->rcap_buf, M_CAMXPT);
>-	free(device->serial_num, M_CAMXPT);
> 	taskqueue_enqueue(xsoftc.xpt_taskq, &device->device_destroy_task);
> }
>

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Attachments on bug 204298: 162793 | 162814 | 162840