1 files changed, 60 insertions, 39 deletions

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 282aac45c690..718fa4e0b31e 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -27,7 +27,7 @@
 #include <linux/miscdevice.h>
 #include <linux/blk_types.h>
 #include <linux/bio.h>
-#include <asm/unaligned.h>
+#include <linux/unaligned.h>
 #include <scsi/scsi_common.h>
 #include <scsi/scsi_proto.h>
 #include <target/target_core_base.h>
@@ -210,6 +210,7 @@ struct vhost_scsi {
 
 struct vhost_scsi_tmf {
 	struct vhost_work vwork;
+	struct work_struct flush_work;
 	struct vhost_scsi *vhost;
 	struct vhost_scsi_virtqueue *svq;
 
@@ -358,14 +359,23 @@ static void vhost_scsi_release_tmf_res(struct vhost_scsi_tmf *tmf)
 	vhost_scsi_put_inflight(inflight);
 }
 
+static void vhost_scsi_drop_cmds(struct vhost_scsi_virtqueue *svq)
+{
+	struct vhost_scsi_cmd *cmd, *t;
+	struct llist_node *llnode;
+
+	llnode = llist_del_all(&svq->completion_list);
+	llist_for_each_entry_safe(cmd, t, llnode, tvc_completion_list)
+		vhost_scsi_release_cmd_res(&cmd->tvc_se_cmd);
+}
+
 static void vhost_scsi_release_cmd(struct se_cmd *se_cmd)
 {
 	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) {
 		struct vhost_scsi_tmf *tmf = container_of(se_cmd,
 					struct vhost_scsi_tmf, se_cmd);
-		struct vhost_virtqueue *vq = &tmf->svq->vq;
 
-		vhost_vq_work_queue(vq, &tmf->vwork);
+		schedule_work(&tmf->flush_work);
 	} else {
 		struct vhost_scsi_cmd *cmd = container_of(se_cmd,
 					struct vhost_scsi_cmd, tvc_se_cmd);
@@ -373,7 +383,8 @@ static void vhost_scsi_release_cmd(struct se_cmd *se_cmd)
 					struct vhost_scsi_virtqueue, vq);
 
 		llist_add(&cmd->tvc_completion_list, &svq->completion_list);
-		vhost_vq_work_queue(&svq->vq, &svq->completion_work);
+		if (!vhost_vq_work_queue(&svq->vq, &svq->completion_work))
+			vhost_scsi_drop_cmds(svq);
 	}
 }
 
@@ -497,10 +508,8 @@ again:
 		vq_err(vq, "Faulted on vhost_scsi_send_event\n");
 }
 
-static void vhost_scsi_evt_work(struct vhost_work *work)
+static void vhost_scsi_complete_events(struct vhost_scsi *vs, bool drop)
 {
-	struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
-					vs_event_work);
 	struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT].vq;
 	struct vhost_scsi_evt *evt, *t;
 	struct llist_node *llnode;
@@ -508,12 +517,20 @@ static void vhost_scsi_evt_work(struct vhost_work *work)
 	mutex_lock(&vq->mutex);
 	llnode = llist_del_all(&vs->vs_event_list);
 	llist_for_each_entry_safe(evt, t, llnode, list) {
-		vhost_scsi_do_evt_work(vs, evt);
+		if (!drop)
+			vhost_scsi_do_evt_work(vs, evt);
 		vhost_scsi_free_evt(vs, evt);
 	}
 	mutex_unlock(&vq->mutex);
 }
 
+static void vhost_scsi_evt_work(struct vhost_work *work)
+{
+	struct vhost_scsi *vs = container_of(work, struct vhost_scsi,
+					     vs_event_work);
+	vhost_scsi_complete_events(vs, false);
+}
+
 static int vhost_scsi_copy_sgl_to_iov(struct vhost_scsi_cmd *cmd)
 {
 	struct iov_iter *iter = &cmd->saved_iter;
@@ -1012,20 +1029,23 @@ vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc,
 		/* virtio-scsi spec requires byte 0 of the lun to be 1 */
 		vq_err(vq, "Illegal virtio-scsi lun: %u\n", *vc->lunp);
 	} else {
-		struct vhost_scsi_tpg **vs_tpg, *tpg;
-
-		vs_tpg = vhost_vq_get_backend(vq);	/* validated at handler entry */
-
-		tpg = READ_ONCE(vs_tpg[*vc->target]);
-		if (unlikely(!tpg)) {
-			vq_err(vq, "Target 0x%x does not exist\n", *vc->target);
-		} else {
-			if (tpgp)
-				*tpgp = tpg;
-			ret = 0;
+		struct vhost_scsi_tpg **vs_tpg, *tpg = NULL;
+
+		if (vc->target) {
+			/* validated at handler entry */
+			vs_tpg = vhost_vq_get_backend(vq);
+			tpg = READ_ONCE(vs_tpg[*vc->target]);
+			if (unlikely(!tpg)) {
+				vq_err(vq, "Target 0x%x does not exist\n", *vc->target);
+				goto out;
+			}
 		}
-	}
 
+		if (tpgp)
+			*tpgp = tpg;
+		ret = 0;
+	}
+out:
 	return ret;
 }
 
@@ -1270,33 +1290,32 @@ static void vhost_scsi_tmf_resp_work(struct vhost_work *work)
 {
 	struct vhost_scsi_tmf *tmf = container_of(work, struct vhost_scsi_tmf,
 						  vwork);
-	struct vhost_virtqueue *ctl_vq, *vq;
-	int resp_code, i;
-
-	if (tmf->scsi_resp == TMR_FUNCTION_COMPLETE) {
-		/*
-		 * Flush IO vqs that don't share a worker with the ctl to make
-		 * sure they have sent their responses before us.
-		 */
-		ctl_vq = &tmf->vhost->vqs[VHOST_SCSI_VQ_CTL].vq;
-		for (i = VHOST_SCSI_VQ_IO; i < tmf->vhost->dev.nvqs; i++) {
-			vq = &tmf->vhost->vqs[i].vq;
-
-			if (vhost_vq_is_setup(vq) &&
-			    vq->worker != ctl_vq->worker)
-				vhost_vq_flush(vq);
-		}
+	int resp_code;
 
+	if (tmf->scsi_resp == TMR_FUNCTION_COMPLETE)
 		resp_code = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
-	} else {
+	else
 		resp_code = VIRTIO_SCSI_S_FUNCTION_REJECTED;
-	}
 
 	vhost_scsi_send_tmf_resp(tmf->vhost, &tmf->svq->vq, tmf->in_iovs,
 				 tmf->vq_desc, &tmf->resp_iov, resp_code);
 	vhost_scsi_release_tmf_res(tmf);
 }
 
+static void vhost_scsi_tmf_flush_work(struct work_struct *work)
+{
+	struct vhost_scsi_tmf *tmf = container_of(work, struct vhost_scsi_tmf,
+						 flush_work);
+	struct vhost_virtqueue *vq = &tmf->svq->vq;
+	/*
+	 * Make sure we have sent responses for other commands before we
+	 * send our response.
+	 */
+	vhost_dev_flush(vq->dev);
+	if (!vhost_vq_work_queue(vq, &tmf->vwork))
+		vhost_scsi_release_tmf_res(tmf);
+}
+
 static void
 vhost_scsi_handle_tmf(struct vhost_scsi *vs, struct vhost_scsi_tpg *tpg,
 		      struct vhost_virtqueue *vq,
@@ -1320,6 +1339,7 @@ vhost_scsi_handle_tmf(struct vhost_scsi *vs, struct vhost_scsi_tpg *tpg,
 	if (!tmf)
 		goto send_reject;
 
+	INIT_WORK(&tmf->flush_work, vhost_scsi_tmf_flush_work);
 	vhost_work_init(&tmf->vwork, vhost_scsi_tmf_resp_work);
 	tmf->vhost = vs;
 	tmf->svq = svq;
@@ -1509,7 +1529,8 @@ vhost_scsi_send_evt(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
 	}
 
 	llist_add(&evt->list, &vs->vs_event_list);
-	vhost_vq_work_queue(vq, &vs->vs_event_work);
+	if (!vhost_vq_work_queue(vq, &vs->vs_event_work))
+		vhost_scsi_complete_events(vs, true);
 }
 
 static void vhost_scsi_evt_handle_kick(struct vhost_work *work)