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| author | Mike Christie <michael.christie@oracle.com> | 2024-03-15 19:46:59 -0500 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2024-05-22 08:31:15 -0400 |
| commit | b1b2ce58ed23c5d56e0ab299a5271ac01f95b75c (patch) | |
| tree | 40a9175d8907d5cc071921e3d682ed8014c27240 /drivers/vhost | |
| parent | 7b1b5c7fff05bdf2dc21ee124907df1f8cc819ad (diff) | |
| download | linux-stable-b1b2ce58ed23c5d56e0ab299a5271ac01f95b75c.tar.gz linux-stable-b1b2ce58ed23c5d56e0ab299a5271ac01f95b75c.tar.bz2 linux-stable-b1b2ce58ed23c5d56e0ab299a5271ac01f95b75c.zip | |
vhost-scsi: Handle vhost_vq_work_queue failures for events
Currently, we can try to queue an event's work before the vhost_task is
created. When this happens we just drop it in vhost_scsi_do_plug before
even calling vhost_vq_work_queue. During a device shutdown we do the
same thing after vhost_scsi_clear_endpoint has cleared the backends.
In the next patches we will be able to kill the vhost_task before we
have cleared the endpoint. In that case, vhost_vq_work_queue can fail
and we will leak the event's memory. This has handle the failure by
just freeing the event. This is safe to do, because
vhost_vq_work_queue will only return failure for us when the vhost_task
is killed and so userspace will not be able to handle events if we
sent them.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20240316004707.45557-2-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/scsi.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 282aac45c690..f34f9895b898 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -497,10 +497,8 @@ 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 +506,20 @@ 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; @@ -1509,7 +1515,8 @@ 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) |