[PATCH] NET : cleanup sock_from_file()

[Eric Dumazet]

I believe dead code from sock_from_file() can be cleaned up.
All sockets are now built using sock_attach_fd(), that puts the 'sock' pointer 
into file->private_data and &socket_file_ops into file->f_op

I could not find a place where file->private_data could be set to NULL, 
keeping opened the file.

So to get 'sock' from a 'file' pointer, either :

- This is a socket file (f_op == &socket_file_ops), and we can directly get 
'sock' from private_data.
- This is not a socket, we return -ENOTSOCK and dont even try to find a socket 
via dentry/inode :)

Signed-off-by: Eric Dumazet <[EMAIL PROTECTED]>
--- linux/net/socket.c  2007-02-07 00:37:44.000000000 +0100
+++ linux-ed/net/socket.c       2007-02-07 00:43:36.000000000 +0100
@@ -407,24 +407,11 @@ int sock_map_fd(struct socket *sock)
 
 static struct socket *sock_from_file(struct file *file, int *err)
 {
-       struct inode *inode;
-       struct socket *sock;
-
        if (file->f_op == &socket_file_ops)
                return file->private_data;      /* set in sock_map_fd */
 
-       inode = file->f_path.dentry->d_inode;
-       if (!S_ISSOCK(inode->i_mode)) {
-               *err = -ENOTSOCK;
-               return NULL;
-       }
-
-       sock = SOCKET_I(inode);
-       if (sock->file != file) {
-               printk(KERN_ERR "socki_lookup: socket file changed!\n");
-               sock->file = file;
-       }
-       return sock;
+       *err = -ENOTSOCK;
+       return NULL;
 }
 
 /**