kernfs: add CONFIG_KERNFS

As sysfs was kernfs's only user, kernfs has been piggybacking on
CONFIG_SYSFS; however, kernfs is scheduled to grow a new user very
soon.  Introduce a separate config option CONFIG_KERNFS which is to be
selected by kernfs users.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

5 files changed, 14 insertions, 4 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index 7385e54be4b9..312393f32948 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -96,6 +96,7 @@ endif # BLOCK
 menu "Pseudo filesystems"
 
 source "fs/proc/Kconfig"
+source "fs/kernfs/Kconfig"
 source "fs/sysfs/Kconfig"
 
 config TMPFS
diff --git a/fs/Makefile b/fs/Makefile
index 47ac07bb4acc..f9cb9876e466 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -52,7 +52,8 @@ obj-$(CONFIG_FHANDLE)		+= fhandle.o
 obj-y                           += quota/
 
 obj-$(CONFIG_PROC_FS)           += proc/
-obj-$(CONFIG_SYSFS)             += sysfs/ kernfs/
+obj-$(CONFIG_KERNFS)            += kernfs/
+obj-$(CONFIG_SYSFS)             += sysfs/
 obj-$(CONFIG_CONFIGFS_FS)       += configfs/
 obj-y                           += devpts/
 
diff --git a/fs/kernfs/Kconfig b/fs/kernfs/Kconfig
new file mode 100644
index 000000000000..397b5f7a7a16
--- /dev/null
+++ b/fs/kernfs/Kconfig
@@ -0,0 +1,7 @@
+#
+# KERNFS should be selected by its users
+#
+
+config KERNFS
+        bool
+        default n
diff --git a/fs/sysfs/Kconfig b/fs/sysfs/Kconfig
index 8c41feacbac5..b2756014508c 100644
--- a/fs/sysfs/Kconfig
+++ b/fs/sysfs/Kconfig
@@ -1,6 +1,7 @@
 config SYSFS
         bool "sysfs file system support" if EXPERT
         default y
+        select KERNFS
         help
         The sysfs filesystem is a virtual filesystem that the kernel uses to
         export internal kernel objects, their attributes, and their
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 8736ee86a1d6..649497a56a95 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -201,7 +201,7 @@ struct kernfs_ops {
 #endif
 };
 
-#ifdef CONFIG_SYSFS
+#ifdef CONFIG_KERNFS
 
 static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
 {
@@ -284,7 +284,7 @@ void kernfs_kill_sb(struct super_block *sb);
 
 void kernfs_init(void);
 
-#else   /* CONFIG_SYSFS */
+#else   /* CONFIG_KERNFS */
 
 static inline enum kernfs_node_type kernfs_type(struct kernfs_node *kn)
 { return 0; }   /* whatever */
@@ -379,7 +379,7 @@ static inline void kernfs_kill_sb(struct super_block *sb) { }
 
 static inline void kernfs_init(void) { }
 
-#endif  /* CONFIG_SYSFS */
+#endif  /* CONFIG_KERNFS */
 
 static inline struct kernfs_node *
 kernfs_find_and_get(struct kernfs_node *kn, const char *name)