linux-kernel - [PATCH 5/6] vhost_net: remove NOP vhost_net_flush() in vhost_net

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Message-Id: <20211115153003.9140-5-arbn@yandex-team.com>
Date:   Mon, 15 Nov 2021 18:30:02 +0300
From:   Andrey Ryabinin <arbn@...dex-team.com>
To:     "Michael S. Tsirkin" <mst@...hat.com>
Cc:     Jason Wang <jasowang@...hat.com>,
        Stefan Hajnoczi <stefanha@...hat.com>,
        Stefano Garzarella <sgarzare@...hat.com>,
        Andrey Ryabinin <arbn@...dex-team.com>, kvm@...r.kernel.org,
        virtualization@...ts.linux-foundation.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 5/6] vhost_net: remove NOP vhost_net_flush() in vhost_net_release()

The second vhost_net_flush() call in vhost_net_release() doesn't do
anything. vhost_dev_cleanup() stops dev->worker and NULLifies it.
vhost_net_reset_vq(n) NULLifies n->vqs[i].ubufs

So vhost_net_flush() after vhost_dev_cleanup()&vhost_net_reset_vq() doesn't
do anything, it simply doesn't pass NULL checks.

Hence remove it for simplicity.

Signed-off-by: Andrey Ryabinin <arbn@...dex-team.com>
---
 drivers/vhost/net.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index b1feb5e0571e..97a209d6a527 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -1406,9 +1406,7 @@ static int vhost_net_release(struct inode *inode, struct file *f)
 		sockfd_put(rx_sock);
 	/* Make sure no callbacks are outstanding */
 	synchronize_rcu();
-	/* We do an extra flush before freeing memory,
-	 * since jobs can re-queue themselves. */
-	vhost_net_flush(n);
+
 	kfree(n->vqs[VHOST_NET_VQ_RX].rxq.queue);
 	kfree(n->vqs[VHOST_NET_VQ_TX].xdp);
 	kfree(n->dev.vqs);
-- 
2.32.0