Re: [PATCHv6 1/3] tun: export underlying socket
From: Arnd Bergmann <arnd@arndb.de>
Date: 2009-11-03 12:41:57
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kvm, linux-mm, lkml
On Tuesday 03 November 2009, Michael S. Tsirkin wrote:
quoted
What was your reason for changing?It turns out socket structure is really bound to specific a file, so we can not have 2 files referencing the same socket. Instead, as I say above, it's possible to make sendmsg/recvmsg work on tap file directly.
Ah, I see.
I have implemented this (patch below), but decided to go with the simple thing first. Since no userspace-visible changes are involved, let's do this by small steps: it will be easier to figure out when vhost is upstream.
This may even make it easier for me to do the same with macvtap if I resume work on that.
quoted hunk ↗ jump to hunk
@@ -416,8 +422,8 @@ int sock_map_fd(struct socket *sock, int flags) static struct socket *sock_from_file(struct file *file, int *err) { - if (file->f_op == &socket_file_ops) - return file->private_data; /* set in sock_map_fd */ + if (file->f_op->get_socket) + return file->f_op->get_socket(file); *err = -ENOTSOCK;
Or maybe do both (socket_file_ops and get_socket), to avoid an indirect function call. Arnd <><