net: set FMODE_NOWAIT for sockets

The socket read/write functions deal with O_NONBLOCK and IOCB_NOWAIT
just fine, so we can flag them as being FMODE_NOWAIT compliant. With
this, we can remove socket special casing in io_uring when checking
if a file type is sane for nonblocking IO, and it's also the defined
way to flag file types as such in the kernel.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Reviewed-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20230509151910.183637-2-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/net/socket.c b/net/socket.c
index b7e01d0..0c7fda1 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -471,6 +471,7 @@ struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
                return file;
        }
 
+       file->f_mode |= FMODE_NOWAIT;
        sock->file = file;
        file->private_data = sock;
        stream_open(SOCK_INODE(sock), file);