vfs: Add a sample program for the new mount API

Add a sample program to demonstrate fsopen/fsmount/move_mount to mount
something.

To make it compile on all arches, irrespective of whether or not syscall
numbers are assigned, define the syscall number to -1 if it isn't to cause
the kernel to return -ENOSYS.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 5 insertions, 4 deletions

diff --git a/samples/Kconfig b/samples/Kconfig
index d19754ccad08..30a89425009c 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -154,10 +154,11 @@ config SAMPLE_ANDROID_BINDERFS
           Builds a sample program to illustrate the use of the Android binderfs
           filesystem.
 
-config SAMPLE_STATX
-        bool "Build example extended-stat using code"
-        depends on BROKEN
+config SAMPLE_VFS
+        bool "Build example programs that use new VFS system calls"
         help
-          Build example userspace program to use the new extended-stat syscall.
+          Build example userspace programs that use new VFS system calls such
+          as mount API and statx().  Note that this is restricted to the x86
+          arch whilst it accesses system calls that aren't yet in all arches.
 
 endif # SAMPLES