afs: Handle CONFIG_PROC_FS=n

The AFS filesystem depends at the moment on /proc for configuration and
also presents information that way - however, this causes a compilation
failure if procfs is disabled.

Fix it so that the procfs bits aren't compiled in if procfs is disabled.

This means that you can't configure the AFS filesystem directly, but it is
still usable provided that an up-to-date keyutils is installed to look up
cells by SRV or AFSDB DNS records.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/Makefile

@@ -5,7 +5,7 @@
 
 afs-cache-$(CONFIG_AFS_FSCACHE) := cache.o
 
-kafs-objs := \
+kafs-y := \
 	$(afs-cache-y) \
 	addr_list.o \
 	callback.o \
@@ -21,7 +21,6 @@ kafs-objs := \
 	main.o \
 	misc.o \
 	mntpt.o \
-	proc.o \
 	rotate.o \
 	rxrpc.o \
 	security.o \
@@ -34,4 +33,5 @@ kafs-objs := \
 	write.o \
 	xattr.o
 
+kafs-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_AFS_FS)  := kafs.o

fs/afs/internal.h

@@ -871,11 +871,19 @@ extern int afs_get_ipv4_interfaces(struct afs_net *, struct afs_interface *,
 /*
  * proc.c
  */
+#ifdef CONFIG_PROC_FS
 extern int __net_init afs_proc_init(struct afs_net *);
 extern void __net_exit afs_proc_cleanup(struct afs_net *);
 extern int afs_proc_cell_setup(struct afs_cell *);
 extern void afs_proc_cell_remove(struct afs_cell *);
 extern void afs_put_sysnames(struct afs_sysnames *);
+#else
+static inline int afs_proc_init(struct afs_net *net) { return 0; }
+static inline void afs_proc_cleanup(struct afs_net *net) {}
+static inline int afs_proc_cell_setup(struct afs_cell *cell) { return 0; }
+static inline void afs_proc_cell_remove(struct afs_cell *cell) {}
+static inline void afs_put_sysnames(struct afs_sysnames *sysnames) {}
+#endif
 
 /*
  * rotate.c