On Wed, Mar 06, 2013 at 02:16:30PM +0800, Asias He wrote:
> +static struct tcm_vhost_evt *tcm_vhost_allocate_evt(struct vhost_scsi *vs,
> + u32 event, u32 reason)
> +{
> + struct tcm_vhost_evt *evt;
> +
> + if (atomic_read(&vs->vs_events_nr) > VHOST_SCSI_MAX_EVENT)
> + return NULL;
> +
> + evt = kzalloc(sizeof(*evt), GFP_KERNEL);
> +
> + if (evt) {
> + atomic_inc(&vs->vs_events_nr);
This looks suspicious: checking vs_events_nr > VHOST_SCSI_MAX_EVENT
first and then incrementing later isn't atomic!
> +static int tcm_vhost_hotunplug(struct tcm_vhost_tpg *tpg, struct se_lun *lun)
> +{
> + struct vhost_scsi *vs = tpg->vhost_scsi;
> +
> + mutex_lock(&tpg->tv_tpg_mutex);
> + vs = tpg->vhost_scsi;
> + mutex_unlock(&tpg->tv_tpg_mutex);
> + if (!vs)
> + return -EOPNOTSUPP;
> +
> + if (!tcm_vhost_check_feature(vs, VIRTIO_SCSI_F_HOTPLUG))
> + return -EOPNOTSUPP;
> +
> + return tcm_vhost_send_evt(vs, tpg, lun,
> + VIRTIO_SCSI_T_TRANSPORT_RESET,
> + VIRTIO_SCSI_EVT_RESET_REMOVED);
> +}
tcm_vhost_hotplug() and tcm_vhost_hotunplug() are the same function
except for VIRTIO_SCSI_EVT_RESET_RESCAN vs
VIRTIO_SCSI_EVT_RESET_REMOVED. That can be passed in as an argument and
the code duplication can be eliminated.
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