Re: [patch] add two inotify_add_watch flags

[Andrew Morton <akpm@osdl.org>]

John McCutchan <ttb@tentacle.dhs.org> wrote:
>
> -static int find_inode(const char __user *dirname, struct nameidata *nd)
> +static int find_inode(const char __user *dirname, struct nameidata *nd,
> +		      int only_dir, int dont_follow_symlink)
>  {
>  	int error;
> +	unsigned flags = 0;
>  
> -	error = __user_walk(dirname, LOOKUP_FOLLOW, nd);
> +	if (!dont_follow_symlink)
> +		flags |= LOOKUP_FOLLOW;
> +	if (only_dir)
> +		flags |= LOOKUP_DIRECTORY;
> +
> +	error = __user_walk(dirname, flags, nd);
>  	if (error)
>  		return error;
>  	/* you can only watch an inode if you have read permissions on it */
> @@ -943,7 +950,7 @@
>  		goto fput_and_out;
>  	}
>  
> -	ret = find_inode(path, &nd);
> +	ret = find_inode(path, &nd, mask & IN_ONLYDIR, mask & IN_DONT_FOLLOW);
>  	if (unlikely(ret))
>  		goto fput_and_out;

I'd have thought that it'd be more general to pass the __user_walk flags
into find_inode(), rather than calculating them in the callee.  Slightly
more efficient too.