AFS: export a couple of core functions for AFS write support

Export a couple of core functions for AFS write support to use:

	find_get_pages_contig()
	find_get_pages_tag()
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/filemap.c

@@ -750,6 +750,7 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
 	read_unlock_irq(&mapping->tree_lock);
 	return i;
 }
+EXPORT_SYMBOL(find_get_pages_contig);
 
 /**
  * find_get_pages_tag - find and return pages that match @tag
@@ -778,6 +779,7 @@ unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
 	read_unlock_irq(&mapping->tree_lock);
 	return ret;
 }
+EXPORT_SYMBOL(find_get_pages_tag);
 
 /**
  * grab_cache_page_nowait - returns locked page at given index in given cache