Linux: fix statfs configure test

The change to the statfs configure test that was made for 2.6.36
broke the test for older kernels.  The new test is based on a call,
and that will generate a warning but not an error when the arguments
don't match the prototype.

Take another tack, and revert to the old style test, but with the
simple_statfs function instead of vfs_statfs.

Reviewed-on: http://gerrit.openafs.org/2975
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
(cherry picked from commit 59927e20052c3f075e0269e46691bc94c3974f86)

Change-Id: Iaee4e3d62ce95c33539ba57c19ddc916b097deb2
Reviewed-on: http://gerrit.openafs.org/3521
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>

diff --git a/src/cf/linux-test4.m4 b/src/cf/linux-test4.m4
index 5eabaa90b7275b8a21eb0359f99f8c7978657b71..89fccf55e019f4413e6078de8a70ebe3dccbbf5e 100644 (file)
--- a/src/cf/linux-test4.m4
+++ b/src/cf/linux-test4.m4
@@ -734,10 +734,7 @@ AC_DEFUN([LINUX_STATFS_TAKES_DENTRY], [
     AC_TRY_KBUILD(
 [#include <linux/fs.h>
 #include <linux/statfs.h>],
-[struct super_block _sb;
-struct dentry _dentry;
-struct kstatfs _kstatfs;
-(void)_sb.s_op->statfs(&_dentry, &_kstatfs);],
+[extern int simple_statfs(struct dentry *, struct kstatfs *);],
       ac_cv_linux_statfs_takes_dentry=yes,
       ac_cv_linux_statfs_takes_dentry=no)])
   AC_MSG_RESULT($ac_cv_linux_statfs_takes_dentry)])