Now that vhost_scsi_clear_endpoint will prevent new IO and flush running IO before dropping it's refcounts on the tpg, we only need to hold the vhost_scsi_mutex while looping over tpgs and taking a refcount, and when manipulating the tpg list.
This removes the vhost_scsi_mutex from vhost_scsi_clear_endpoint and moves the vhost_scsi_mutex use in vhost_scsi_set_endpoint so it's only taken while looping over the tpgs and taking a refcount. We can then now avoid issues where vhost_scsi_set_endpoint has to wait for another device's vhost_scsi_clear_endpoint call. Signed-off-by: Mike Christie <[email protected]> --- drivers/vhost/scsi.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index c405ab5c232a..75ea24f1c571 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -1540,7 +1540,7 @@ static int vhost_scsi_setup_vq_cmds(struct vhost_virtqueue *vq, int max_cmds) * vhost_scsi_tpg with an active struct vhost_scsi_nexus * * The lock nesting rule is: - * vhost_scsi_mutex -> vs->dev.mutex -> tpg->tv_tpg_mutex -> vq->mutex + * vs->dev.mutex -> vhost_scsi_mutex -> tpg->tv_tpg_mutex -> vq->mutex */ static int vhost_scsi_set_endpoint(struct vhost_scsi *vs, @@ -1554,7 +1554,6 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, int index, ret, i, len; bool match = false; - mutex_lock(&vhost_scsi_mutex); mutex_lock(&vs->dev.mutex); /* Verify that ring has been setup correctly. */ @@ -1575,6 +1574,7 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, if (vs->vs_tpg) memcpy(vs_tpg, vs->vs_tpg, len); + mutex_lock(&vhost_scsi_mutex); list_for_each_entry(tpg, &vhost_scsi_list, tv_tpg_list) { mutex_lock(&tpg->tv_tpg_mutex); if (!tpg->tpg_nexus) { @@ -1590,6 +1590,7 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) { if (vs->vs_tpg && vs->vs_tpg[tpg->tport_tpgt]) { mutex_unlock(&tpg->tv_tpg_mutex); + mutex_unlock(&vhost_scsi_mutex); ret = -EEXIST; goto undepend; } @@ -1604,6 +1605,7 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, if (ret) { pr_warn("target_depend_item() failed: %d\n", ret); mutex_unlock(&tpg->tv_tpg_mutex); + mutex_unlock(&vhost_scsi_mutex); goto undepend; } tpg->tv_tpg_vhost_count++; @@ -1613,6 +1615,7 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, } mutex_unlock(&tpg->tv_tpg_mutex); } + mutex_unlock(&vhost_scsi_mutex); if (match) { memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn, @@ -1667,7 +1670,6 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, kfree(vs_tpg); out: mutex_unlock(&vs->dev.mutex); - mutex_unlock(&vhost_scsi_mutex); return ret; } @@ -1683,7 +1685,6 @@ vhost_scsi_clear_endpoint(struct vhost_scsi *vs, int index, ret, i; u8 target; - mutex_lock(&vhost_scsi_mutex); mutex_lock(&vs->dev.mutex); /* Verify that ring has been setup correctly. */ for (index = 0; index < vs->dev.nvqs; ++index) { @@ -1765,12 +1766,10 @@ vhost_scsi_clear_endpoint(struct vhost_scsi *vs, vs->vs_tpg = NULL; WARN_ON(vs->vs_events_nr); mutex_unlock(&vs->dev.mutex); - mutex_unlock(&vhost_scsi_mutex); return 0; err_dev: mutex_unlock(&vs->dev.mutex); - mutex_unlock(&vhost_scsi_mutex); return ret; } -- 2.25.1 _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
