This patch makes vhost_scsi_flush() wait for all the pending requests issued before the flush operation to be finished.
Signed-off-by: Asias He <[email protected]> --- drivers/vhost/tcm_vhost.c | 115 ++++++++++++++++++++++++++++++++++++++-------- drivers/vhost/tcm_vhost.h | 4 ++ 2 files changed, 101 insertions(+), 18 deletions(-) diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c index f80a545..5f8342c 100644 --- a/drivers/vhost/tcm_vhost.c +++ b/drivers/vhost/tcm_vhost.c @@ -84,6 +84,15 @@ struct vhost_scsi { bool vs_events_dropped; /* any missed events, protected by dev.mutex */ u64 vs_events_nr; /* # of pennding events, protected by dev.mutex */ + /* + * vs_inflight[0]/[1] are used to track requests issued + * before/during the flush operation + */ + u64 vs_inflight[2]; + wait_queue_head_t vs_flush_wait; /* wait queue for flush operation */ + spinlock_t vs_flush_lock; /* lock to protect vs_during_flush */ + int vs_during_flush; /* flag to indicate if we are in flush operation */ + }; /* Local pointer to allocated TCM configfs fabric module */ @@ -101,6 +110,46 @@ static int iov_num_pages(struct iovec *iov) ((unsigned long)iov->iov_base & PAGE_MASK)) >> PAGE_SHIFT; } +static int tcm_vhost_inc_inflight(struct vhost_scsi *vs) +{ + int during_flush; + + spin_lock(&vs->vs_flush_lock); + during_flush = vs->vs_during_flush; + vs->vs_inflight[during_flush]++; + spin_unlock(&vs->vs_flush_lock); + + return during_flush; +} + +static void tcm_vhost_dec_inflight(struct vhost_scsi *vs, int during_flush) +{ + u64 inflight; + + spin_lock(&vs->vs_flush_lock); + inflight = vs->vs_inflight[during_flush]--; + /* + * Wakeup the waiter when all the requests issued before the flush + * operation are finished and we are during the flush operation. + */ + if (!inflight && !during_flush && vs->vs_during_flush) + wake_up(&vs->vs_flush_wait); + spin_unlock(&vs->vs_flush_lock); +} + +static bool tcm_vhost_done_inflight(struct vhost_scsi *vs) +{ + bool ret = false; + + /* The requests issued before the flush operation are finished ? */ + spin_lock(&vs->vs_flush_lock); + if (!vs->vs_inflight[0]) + ret = true; + spin_unlock(&vs->vs_flush_lock); + + return ret; +} + static bool tcm_vhost_check_feature(struct vhost_scsi *vs, int feature) { bool ret = false; @@ -433,9 +482,10 @@ static void vhost_scsi_free_cmd(struct tcm_vhost_cmd *tv_cmd) } static void tcm_vhost_do_evt_work(struct vhost_scsi *vs, - struct virtio_scsi_event *event) + struct tcm_vhost_evt *evt) { struct vhost_virtqueue *vq = &vs->vqs[VHOST_SCSI_VQ_EVT]; + struct virtio_scsi_event *event = &evt->event; struct virtio_scsi_event __user *eventp; unsigned out, in; int head, ret; @@ -493,13 +543,16 @@ static void tcm_vhost_evt_work(struct vhost_work *work) vs_event_work); struct tcm_vhost_evt *evt; struct llist_node *llnode; + int during_flush; llnode = llist_del_all(&vs->vs_event_list); while (llnode) { evt = llist_entry(llnode, struct tcm_vhost_evt, list); llnode = llist_next(llnode); - tcm_vhost_do_evt_work(vs, &evt->event); + tcm_vhost_do_evt_work(vs, evt); + during_flush = evt->during_flush; tcm_vhost_free_evt(vs, evt); + tcm_vhost_dec_inflight(vs, during_flush); } } @@ -516,8 +569,8 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) struct virtio_scsi_cmd_resp v_rsp; struct tcm_vhost_cmd *tv_cmd; struct llist_node *llnode; + int ret, vq, during_flush; struct se_cmd *se_cmd; - int ret, vq; bitmap_zero(signal, VHOST_SCSI_MAX_VQ); llnode = llist_del_all(&vs->vs_completion_list); @@ -545,7 +598,9 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) } else pr_err("Faulted on virtio_scsi_cmd_resp\n"); + during_flush = tv_cmd->during_flush; vhost_scsi_free_cmd(tv_cmd); + tcm_vhost_dec_inflight(vs, during_flush); } vq = -1; @@ -711,6 +766,7 @@ static void tcm_vhost_submission_work(struct work_struct *work) transport_send_check_condition_and_sense(se_cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0); transport_generic_free_cmd(se_cmd, 0); + tcm_vhost_dec_inflight(tv_cmd->tvc_vhost, tv_cmd->during_flush); } } @@ -883,6 +939,9 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs, * tcm_vhost_queue_data_in() and tcm_vhost_queue_status() */ tv_cmd->tvc_vq_desc = head; + + tv_cmd->during_flush = tcm_vhost_inc_inflight(vs); + /* * Dispatch tv_cmd descriptor for cmwq execution in process * context provided by tcm_vhost_workqueue. This also ensures @@ -926,6 +985,8 @@ static int tcm_vhost_send_evt(struct vhost_scsi *vs, struct tcm_vhost_tpg *tpg, evt->event.lun[3] = lun->unpacked_lun & 0xFF; } + evt->during_flush = tcm_vhost_inc_inflight(vs); + llist_add(&evt->list, &vs->vs_event_list); vhost_work_queue(&vs->dev, &vs->vs_event_work); @@ -952,6 +1013,34 @@ static void vhost_scsi_handle_kick(struct vhost_work *work) vhost_scsi_handle_vq(vs, vq); } +static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index) +{ + vhost_poll_flush(&vs->dev.vqs[index].poll); +} + +static void vhost_scsi_flush(struct vhost_scsi *vs) +{ + int i; + + /* Flush operation is started */ + spin_lock(&vs->vs_flush_lock); + vs->vs_during_flush = 1; + spin_unlock(&vs->vs_flush_lock); + + 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 until all requests issued before the flush to be finished */ + wait_event(vs->vs_flush_wait, tcm_vhost_done_inflight(vs)); + + /* Flush operation is finished */ + spin_lock(&vs->vs_flush_lock); + vs->vs_during_flush = 0; + spin_unlock(&vs->vs_flush_lock); +} + /* * Called from vhost_scsi_ioctl() context to walk the list of available * tcm_vhost_tpg with an active struct tcm_vhost_nexus @@ -1028,6 +1117,7 @@ static int vhost_scsi_clear_endpoint( u8 target; mutex_lock(&vs->dev.mutex); + /* Verify that ring has been setup correctly. */ for (index = 0; index < vs->dev.nvqs; ++index) { if (!vhost_vq_access_ok(&vs->vqs[index])) { @@ -1086,6 +1176,10 @@ static int vhost_scsi_open(struct inode *inode, struct file *f) vhost_work_init(&s->vs_event_work, tcm_vhost_evt_work); s->vs_events_nr = 0; + s->vs_inflight[0] = 0; + s->vs_inflight[1] = 0; + spin_lock_init(&s->vs_flush_lock); + init_waitqueue_head(&s->vs_flush_wait); s->vqs[VHOST_SCSI_VQ_CTL].handle_kick = vhost_scsi_ctl_handle_kick; s->vqs[VHOST_SCSI_VQ_EVT].handle_kick = vhost_scsi_evt_handle_kick; @@ -1116,21 +1210,6 @@ static int vhost_scsi_release(struct inode *inode, struct file *f) return 0; } -static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index) -{ - vhost_poll_flush(&vs->dev.vqs[index].poll); -} - -static void vhost_scsi_flush(struct vhost_scsi *vs) -{ - int i; - - 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); -} - static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features) { if (features & ~VHOST_SCSI_FEATURES) diff --git a/drivers/vhost/tcm_vhost.h b/drivers/vhost/tcm_vhost.h index 94e9ee53..dd84622 100644 --- a/drivers/vhost/tcm_vhost.h +++ b/drivers/vhost/tcm_vhost.h @@ -37,6 +37,8 @@ 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; + /* Indicate this command is issued during the flush operaton */ + int during_flush; }; struct tcm_vhost_nexus { @@ -91,6 +93,8 @@ struct tcm_vhost_evt { struct virtio_scsi_event event; /* virtio_scsi event list, serviced from vhost worker thread */ struct llist_node list; + /* Indicate this event is issued during the flush operaton */ + int during_flush; }; /* -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
