autofs: create autofs Kconfig and Makefile

Create Makefile and Kconfig for autofs module.

[raven@themaw.net: make autofs4 Kconfig depend on AUTOFS_FS]
  Link: http://lkml.kernel.org/r/152687649097.8263.7046086367407522029.stgit@pluto.themaw.net
Link: http://lkml.kernel.org/r/152626705591.28589.356365986974038383.stgit@pluto.themaw.netSigned-off-by: Ian Kent <raven@themaw.net>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/Kconfig

@@ -108,6 +108,7 @@ source "fs/notify/Kconfig"
 
 source "fs/quota/Kconfig"
 
+source "fs/autofs/Kconfig"
 source "fs/autofs4/Kconfig"
 source "fs/fuse/Kconfig"
 source "fs/overlayfs/Kconfig"

fs/Makefile

@@ -102,6 +102,7 @@ obj-$(CONFIG_AFFS_FS)		+= affs/
 obj-$(CONFIG_ROMFS_FS)		+= romfs/
 obj-$(CONFIG_QNX4FS_FS)		+= qnx4/
 obj-$(CONFIG_QNX6FS_FS)		+= qnx6/
+obj-$(CONFIG_AUTOFS_FS)		+= autofs/
 obj-$(CONFIG_AUTOFS4_FS)	+= autofs4/
 obj-$(CONFIG_ADFS_FS)		+= adfs/
 obj-$(CONFIG_FUSE_FS)		+= fuse/

fs/autofs/Kconfig

+config AUTOFS_FS
+	tristate "Kernel automounter support (supports v3, v4 and v5)"
+	default n
+	help
+	   The automounter is a tool to automatically mount remote file systems
+	   on demand. This implementation is partially kernel-based to reduce
+	   overhead in the already-mounted case; this is unlike the BSD
+	   automounter (amd), which is a pure user space daemon.
+
+	   To use the automounter you need the user-space tools from
+	   <https://www.kernel.org/pub/linux/daemons/autofs/>; you also want
+	   to answer Y to "NFS file system support", below.
+
+	   To compile this support as a module, choose M here: the module will be
+	   called autofs.
+
+	   If you are not a part of a fairly large, distributed network or
+	   don't have a laptop which needs to dynamically reconfigure to the
+	   local network, you probably do not need an automounter, and can say
+	   N here.

fs/autofs/Makefile

+#
+# Makefile for the linux autofs-filesystem routines.
+#
+
+obj-$(CONFIG_AUTOFS_FS) += autofs.o
+
+autofs-objs := init.o inode.o root.o symlink.o waitq.o expire.o dev-ioctl.o

fs/autofs4/Kconfig

 config AUTOFS4_FS
 	tristate "Kernel automounter version 4 support (also supports v3 and v5)"
 	default n
+	depends on AUTOFS_FS = n
 	help
 	  The automounter is a tool to automatically mount remote file systems
 	  on demand. This implementation is partially kernel-based to reduce
@@ -30,3 +31,10 @@ config AUTOFS4_FS
 	  - any "alias autofs autofs4" will need to be removed.
 
 	  Please configure AUTOFS_FS instead of AUTOFS4_FS from now on.
+
+	  NOTE: Since the modules autofs and autofs4 use the same file system
+		type name of "autofs" only one can be built. The "depends"
+		above will result in AUTOFS4_FS not appearing in .config for
+		any setting of AUTOFS_FS other than n and AUTOFS4_FS will
+		appear under the AUTOFS_FS entry otherwise which is intended
+		to draw attention to the module rename change.