2 dnl # 4.16 kernel: check if struct posix_acl acl.a_refcount is a refcount_t.
3 dnl # It's an atomic_t on older kernels.
5 AC_DEFUN([ZFS_AC_KERNEL_ACL_HAS_REFCOUNT], [
6 AC_MSG_CHECKING([whether posix_acl has refcount_t])
7 ZFS_LINUX_TRY_COMPILE([
8 #include <linux/backing-dev.h>
9 #include <linux/refcount.h>
10 #include <linux/posix_acl.h>
13 refcount_t *r __attribute__ ((unused)) = &acl.a_refcount;
16 AC_DEFINE(HAVE_ACL_REFCOUNT, 1, [posix_acl has refcount_t])