25 lines
844 B
Text
25 lines
844 B
Text
dnl #
|
|
dnl # Interface for issuing a discard bio:
|
|
dnl # 2.6.28-2.6.35: BIO_RW_DISCARD
|
|
dnl # 2.6.36-3.x: REQ_DISCARD
|
|
dnl #
|
|
|
|
dnl # Since REQ_DISCARD is a preprocessor definition, there is no need for an
|
|
dnl # autotools check for it. Also, REQ_DISCARD existed in the request layer
|
|
dnl # until torvalds/linux@7b6d91daee5cac6402186ff224c3af39d79f4a0e unified the
|
|
dnl # request layer and bio layer flags, so it would be wrong to assume that
|
|
dnl # the APIs are mutually exclusive contrary to the typical case.
|
|
AC_DEFUN([ZFS_AC_KERNEL_BIO_RW_DISCARD], [
|
|
AC_MSG_CHECKING([whether BIO_RW_DISCARD is defined])
|
|
ZFS_LINUX_TRY_COMPILE([
|
|
#include <linux/bio.h>
|
|
],[
|
|
int flags __attribute__ ((unused));
|
|
flags = BIO_RW_DISCARD;
|
|
],[
|
|
AC_MSG_RESULT(yes)
|
|
AC_DEFINE(HAVE_BIO_RW_DISCARD, 1, [BIO_RW_DISCARD is defined])
|
|
],[
|
|
AC_MSG_RESULT(no)
|
|
])
|
|
])
|