freebsd-nq/config/kernel-acl-refcount.m4
Tony Hutter a5369b61a2 Linux 4.16 compat: use correct *_dec_and_test()
Use refcount_dec_and_test() on 4.16+ kernels, atomic_dec_and_test()
on older kernels.  https://lwn.net/Articles/714974/

Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes: #7179 
Closes: #7211
2018-02-22 09:02:06 -08:00

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dnl #
dnl # 4.16 kernel: check if struct posix_acl acl.a_refcount is a refcount_t.
dnl # It's an atomic_t on older kernels.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_ACL_HAS_REFCOUNT], [
AC_MSG_CHECKING([whether posix_acl has refcount_t])
ZFS_LINUX_TRY_COMPILE([
#include <linux/backing-dev.h>
#include <linux/refcount.h>
#include <linux/posix_acl.h>
],[
struct posix_acl acl;
refcount_t *r __attribute__ ((unused)) = &acl.a_refcount;
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_ACL_REFCOUNT, 1, [posix_acl has refcount_t])
],[
AC_MSG_RESULT(no)
])
])