FS-Cache: Make kAFS use FS-Cache

The attached patch makes the kAFS filesystem in fs/afs/ use FS-Cache, and
through it any attached caches.  The kAFS filesystem will use caching
automatically if it's available.

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>

fs/afs/Kconfig

@@ -19,3 +19,11 @@ config AFS_DEBUG
 	  See <file:Documentation/filesystems/afs.txt> for more information.
 
 	  If unsure, say N.
+
+config AFS_FSCACHE
+	bool "Provide AFS client caching support (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
+	depends on AFS_FS=m && FSCACHE || AFS_FS=y && FSCACHE=y
+	help
+	  Say Y here if you want AFS data to be cached locally on disk through
+	  the generic filesystem cache manager

fs/afs/Makefile

@@ -2,7 +2,10 @@
 # Makefile for Red Hat Linux AFS client.
 #
 
+afs-cache-$(CONFIG_AFS_FSCACHE) := cache.o
+
 kafs-objs := \
+	$(afs-cache-y) \
 	callback.o \
 	cell.o \
 	cmservice.o \