40 lines
1.5 KiB
Text
40 lines
1.5 KiB
Text
|
dnl #
|
||
|
|
dnl # 2.6.30 API change
|
||
|
|
dnl #
|
||
|
|
dnl # The bdev_physical_block_size() interface was added to provide a way
|
||
|
|
dnl # to determine the smallest write which can be performed without a
|
||
|
|
dnl # read-modify-write operation. From the kernel documentation:
|
||
|
|
dnl #
|
||
|
|
dnl # What: /sys/block/<disk>/queue/physical_block_size
|
||
|
|
dnl # Date: May 2009
|
||
|
|
dnl # Contact: Martin K. Petersen <martin.petersen@oracle.com>
|
||
|
|
dnl # Description:
|
||
|
|
dnl # This is the smallest unit the storage device can write
|
||
|
|
dnl # without resorting to read-modify-write operation. It is
|
||
|
|
dnl # usually the same as the logical block size but may be
|
||
|
|
dnl # bigger. One example is SATA drives with 4KB sectors
|
||
|
|
dnl # that expose a 512-byte logical block size to the
|
||
|
|
dnl # operating system.
|
||
|
|
dnl #
|
||
|
|
dnl # Unfortunately, this interface isn't entirely reliable because
|
||
|
|
dnl # drives are sometimes known to misreport this value.
|
||
|
|
dnl #
|
||
|
|
AC_DEFUN([ZFS_AC_KERNEL_BDEV_PHYSICAL_BLOCK_SIZE], [
|
||
|
|
AC_MSG_CHECKING([whether bdev_physical_block_size() is available])
|
||
|
|
tmp_flags="$EXTRA_KCFLAGS"
|
||
|
|
EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
|
||
|
|
ZFS_LINUX_TRY_COMPILE([
|
||
|
|
#include <linux/blkdev.h>
|
||
|
|
],[
|
||
|
|
struct block_device *bdev = NULL;
|
||
|
|
bdev_physical_block_size(bdev);
|
||
|
|
],[
|
||
|
|
AC_MSG_RESULT(yes)
|
||
|
|
AC_DEFINE(HAVE_BDEV_PHYSICAL_BLOCK_SIZE, 1,
|
||
|
|
[bdev_physical_block_size() is available])
|
||
|
|
],[
|
||
|
|
AC_MSG_RESULT(no)
|
||
|
|
])
|
||
|
|
EXTRA_KCFLAGS="$tmp_flags"
|
||
|
|
])
|