Messages in this thread | | | Date | Tue, 6 Oct 2020 21:34:32 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH 4.19 07/38] vsock/virtio: stop workers during the .remove() |
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Hi!
> [ Upstream commit 17dd1367389cfe7f150790c83247b68e0c19d106 ] > > Before to call vdev->config->reset(vdev) we need to be sure that > no one is accessing the device, for this reason, we add new variables > in the struct virtio_vsock to stop the workers during the .remove(). > > This patch also add few comments before vdev->config->reset(vdev) > and vdev->config->del_vqs(vdev).
> @@ -621,12 +645,18 @@ static int virtio_vsock_probe(struct virtio_device *vdev) > INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work); > INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work); > > + mutex_lock(&vsock->tx_lock); > + vsock->tx_run = true; > + mutex_unlock(&vsock->tx_lock); > + > mutex_lock(&vsock->rx_lock); > virtio_vsock_rx_fill(vsock); > + vsock->rx_run = true; > mutex_unlock(&vsock->rx_lock); > > mutex_lock(&vsock->event_lock); > virtio_vsock_event_fill(vsock); > + vsock->event_run = true; > mutex_unlock(&vsock->event_lock); >
This looks like some kind of voodoo code. Locks are just being allocated few lines above, so there are no other threads accessing *vsock. That means we don't need to take the locks... right?
At least taking the tx_lock is unneccessary, but probably the others, too...
Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html [unhandled content-type:application/pgp-signature] | |