FS-Cache: Provide a slab for cookie allocation

Provide a slab from which can be allocated the FS-Cache cookies that will be
presented to the netfs.

Also provide a slab constructor and a function to recursively discard a cookie
and its ancestor chain.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index 0a2069a..4c6ba56 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -37,6 +37,14 @@
 	struct fscache_cookie *);
 
 /*
+ * fsc-cookie.c
+ */
+extern struct kmem_cache *fscache_cookie_jar;
+
+extern void fscache_cookie_init_once(void *);
+extern void __fscache_cookie_put(struct fscache_cookie *);
+
+/*
  * fsc-fsdef.c
  */
 extern struct fscache_cookie fscache_fsdef_index;