diff options
| -rw-r--r-- | drivers/vhost/tcm_vhost.c | 90 | ||||
| -rw-r--r-- | drivers/vhost/tcm_vhost.h | 3 |
2 files changed, 92 insertions, 1 deletions
diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c index 99d3480..afb5308 100644 --- a/drivers/vhost/tcm_vhost.c +++ b/drivers/vhost/tcm_vhost.c @@ -74,8 +74,19 @@ enum { #define VHOST_SCSI_MAX_VQ 128 #define VHOST_SCSI_MAX_EVENT 128 +struct vhost_scsi_inflight { + /* Wait for the flush operation to finish */ + struct completion comp; + /* Refcount for the inflight reqs */ + struct kref kref; +}; + struct vhost_scsi_virtqueue { struct vhost_virtqueue vq; + /* Track inflight reqs, protected by vq->mutex */ + struct vhost_scsi_inflight inflights[2]; + /* Indicate current inflight in use, protected by vq->mutex */ + int inflight_idx; }; struct vhost_scsi { @@ -111,6 +122,59 @@ static int iov_num_pages(struct iovec *iov) ((unsigned long)iov->iov_base & PAGE_MASK)) >> PAGE_SHIFT; } +void tcm_vhost_done_inflight(struct kref *kref) +{ + struct vhost_scsi_inflight *inflight; + + inflight = container_of(kref, struct vhost_scsi_inflight, kref); + complete(&inflight->comp); +} + +static void tcm_vhost_init_inflight(struct vhost_scsi *vs, + struct vhost_scsi_inflight *old_inflight[]) +{ + struct vhost_scsi_inflight *new_inflight; + struct vhost_virtqueue *vq; + int idx, i; + + for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) { + vq = &vs->vqs[i].vq; + + mutex_lock(&vq->mutex); + + /* store old infight */ + idx = vs->vqs[i].inflight_idx; + if (old_inflight) + old_inflight[i] = &vs->vqs[i].inflights[idx]; + + /* setup new infight */ + vs->vqs[i].inflight_idx = idx ^ 1; + new_inflight = &vs->vqs[i].inflights[idx ^ 1]; + kref_init(&new_inflight->kref); + init_completion(&new_inflight->comp); + + mutex_unlock(&vq->mutex); + } +} + +static struct vhost_scsi_inflight * +tcm_vhost_get_inflight(struct vhost_virtqueue *vq) +{ + struct vhost_scsi_inflight *inflight; + struct vhost_scsi_virtqueue *svq; + + svq = container_of(vq, struct vhost_scsi_virtqueue, vq); + inflight = &svq->inflights[svq->inflight_idx]; + kref_get(&inflight->kref); + + return inflight; +} + +static void tcm_vhost_put_inflight(struct vhost_scsi_inflight *inflight) +{ + kref_put(&inflight->kref, tcm_vhost_done_inflight); +} + static int tcm_vhost_check_true(struct se_portal_group *se_tpg) { return 1; @@ -407,6 +471,8 @@ static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd) kfree(tv_cmd->tvc_sgl); } + tcm_vhost_put_inflight(tv_cmd->inflight); + kfree(tv_cmd); } @@ -533,6 +599,7 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) } static struct tcm_vhost_cmd *vhost_scsi_allocate_cmd( + struct vhost_virtqueue *vq, struct tcm_vhost_tpg *tv_tpg, struct virtio_scsi_cmd_req *v_req, u32 exp_data_len, @@ -557,6 +624,7 @@ static struct tcm_vhost_cmd *vhost_scsi_allocate_cmd( tv_cmd->tvc_exp_data_len = exp_data_len; tv_cmd->tvc_data_direction = data_direction; tv_cmd->tvc_nexus = tv_nexus; + tv_cmd->inflight = tcm_vhost_get_inflight(vq); return tv_cmd; } @@ -812,7 +880,7 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs, for (i = 0; i < data_num; i++) exp_data_len += vq->iov[data_first + i].iov_len; - tv_cmd = vhost_scsi_allocate_cmd(tv_tpg, &v_req, + tv_cmd = vhost_scsi_allocate_cmd(vq, tv_tpg, &v_req, exp_data_len, data_direction); if (IS_ERR(tv_cmd)) { vq_err(vq, "vhost_scsi_allocate_cmd failed %ld\n", @@ -949,12 +1017,29 @@ static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index) static void vhost_scsi_flush(struct vhost_scsi *vs) { + struct vhost_scsi_inflight *old_inflight[VHOST_SCSI_MAX_VQ]; int i; + /* Init new inflight and remember the old inflight */ + tcm_vhost_init_inflight(vs, old_inflight); + + /* + * The inflight->kref was initialized to 1. We decrement it here to + * indicate the start of the flush operation so that it will reach 0 + * when all the reqs are finished. + */ + for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) + kref_put(&old_inflight[i]->kref, tcm_vhost_done_inflight); + + /* Flush both the vhost poll and vhost work */ for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) vhost_scsi_flush_vq(vs, i); vhost_work_flush(&vs->dev, &vs->vs_completion_work); vhost_work_flush(&vs->dev, &vs->vs_event_work); + + /* Wait for all reqs issued before the flush to be finished */ + for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) + wait_for_completion(&old_inflight[i]->comp); } /* @@ -1185,6 +1270,9 @@ static int vhost_scsi_open(struct inode *inode, struct file *f) s->vqs[i].vq.handle_kick = vhost_scsi_handle_kick; } r = vhost_dev_init(&s->dev, vqs, VHOST_SCSI_MAX_VQ); + + tcm_vhost_init_inflight(s, NULL); + if (r < 0) { kfree(vqs); kfree(s); diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h index 514b9fd..26a57c2 100644 --- a/drivers/vhost/tcm_vhost.h +++ b/drivers/vhost/tcm_vhost.h @@ -2,6 +2,7 @@ #define TCM_VHOST_NAMELEN 256 #define TCM_VHOST_MAX_CDB_SIZE 32 +struct vhost_scsi_inflight; struct tcm_vhost_cmd { /* Descriptor from vhost_get_vq_desc() for virt_queue segment */ int tvc_vq_desc; @@ -37,6 +38,8 @@ struct tcm_vhost_cmd { unsigned char tvc_sense_buf[TRANSPORT_SENSE_BUFFER]; /* Completed commands list, serviced from vhost worker thread */ struct llist_node tvc_completion_list; + /* Used to track inflight cmd */ + struct vhost_scsi_inflight *inflight; }; struct tcm_vhost_nexus { |
