[PATCH] Make address_space_operations->invalidatepage return void

The return value of this function is never used, so let's be honest and
declare it as void.

Some places where invalidatepage returned 0, I have inserted comments
suggesting a BUG_ON.

[akpm@osdl.org: JBD BUG fix]
[akpm@osdl.org: rework for git-nfs]
[akpm@osdl.org: don't go BUG in block_invalidate_page()]
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 972435d..9674679 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -369,7 +369,7 @@
 	int (*commit_write)(struct file *, struct page *, unsigned, unsigned);
 	/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
 	sector_t (*bmap)(struct address_space *, sector_t);
-	int (*invalidatepage) (struct page *, unsigned long);
+	void (*invalidatepage) (struct page *, unsigned long);
 	int (*releasepage) (struct page *, gfp_t);
 	ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
 			loff_t offset, unsigned long nr_segs);