On Sat, Jan 06, 2007 at 12:16:11PM -0800, Andrew Morton wrote:

On Sat, 6 Jan 2007 22:58:31 +0300
Alexey Dobriyan [off-list ref] wrote:

quoted

--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c

@@ -70,6 +70,7 @@ static struct dentry *ext2_lookup(struct
 	return d_splice_alias(inode, dentry);
 }

+#if defined(CONFIG_EXPORTFS) || defined(CONFIG_EXPORTFS_MODULE)
 struct dentry *ext2_get_parent(struct dentry *child)

hm.  Officially, one module isn't supposed to know about the presence of
another one at compile-time.

Whole new requirement.

Someone might want to come along and later
configure and compile the nfsd module and then try to load it into a kernel
which wasn't compiled with nfsd enabled.

methinks, this is not a case.

	agrep _MODULE -n | grep defined -w

shows plenty of cases, where code is conditionally compiled out with
CONFIG_IPV6 being the major "offender".

But given that both modules are in mainline I suspect that nobody would
really be doing that in practice, and in the case of nfsd it might not even
work.

Yes, compat_sys_nfsservctl() is conditionally compiled in.

I interpret CONFIG_FOO=n as
"I am not going to use FOO, not now, not in future".