vhost-scsi: Always access vq->private_data under vq mutex

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 4 insertions, 7 deletions

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 4264840ef7dc..45365396dbbc 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -896,19 +896,15 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
         int head, ret;
         u8 target;
 
+        mutex_lock(&vq->mutex);
         /*
          * We can handle the vq only after the endpoint is setup by calling the
          * VHOST_SCSI_SET_ENDPOINT ioctl.
-         *
-         * TODO: Check that we are running from vhost_worker which acts
-         * as read-side critical section for vhost kind of RCU.
-         * See the comments in struct vhost_virtqueue in drivers/vhost/vhost.h
          */
-        vs_tpg = rcu_dereference_check(vq->private_data, 1);
+        vs_tpg = vq->private_data;
         if (!vs_tpg)
-                return;
+                goto out;
 
-        mutex_lock(&vq->mutex);
         vhost_disable_notify(&vs->dev, vq);
 
         for (;;) {
@@ -1058,6 +1054,7 @@ err_free:
         vhost_scsi_free_cmd(cmd);
 err_cmd:
         vhost_scsi_send_bad_target(vs, vq, head, out);
+out:
         mutex_unlock(&vq->mutex);
 }