mirror_zfs/config/kernel.m4
Brian Behlendorf 2959d94a0a Add FAILFAST support
ZFS works best when it is notified as soon as possible when a device
failure occurs.  This allows it to immediately start any recovery
actions which may be needed.  In theory Linux supports a flag which
can be set on bio's called FAILFAST which provides this quick
notification by disabling the retry logic in the lower scsi layers.

That's the theory at least.  In practice is turns out that while the
flag exists you oddly have to set it with the BIO_RW_AHEAD flag.
And even when it's set it you may get retries in the low level
drivers decides that's the right behavior, or if you don't get the
right error codes reported to the scsi midlayer.

Unfortunately, without additional kernels patchs there's not much
which can be done to improve this.  Basically, this just means that
it may take 2-3 minutes before a ZFS is notified properly that a
device has failed.  This can be improved and I suspect I'll be
submitting patches upstream to handle this.
2010-10-12 14:55:02 -07:00

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dnl #
dnl # Default ZFS kernel configuration
dnl #
AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
ZFS_AC_KERNEL
ZFS_AC_SPL
ZFS_AC_KERNEL_CONFIG
ZFS_AC_KERNEL_BDEV_BLOCK_DEVICE_OPERATIONS
ZFS_AC_KERNEL_TYPE_FMODE_T
ZFS_AC_KERNEL_KOBJ_NAME_LEN
ZFS_AC_KERNEL_OPEN_BDEV_EXCLUSIVE
ZFS_AC_KERNEL_INVALIDATE_BDEV_ARGS
ZFS_AC_KERNEL_BDEV_LOGICAL_BLOCK_SIZE
ZFS_AC_KERNEL_BIO_EMPTY_BARRIER
ZFS_AC_KERNEL_BIO_FAILFAST
ZFS_AC_KERNEL_BIO_END_IO_T_ARGS
ZFS_AC_KERNEL_BIO_RW_SYNCIO
ZFS_AC_KERNEL_BLK_END_REQUEST
ZFS_AC_KERNEL_BLK_FETCH_REQUEST
ZFS_AC_KERNEL_BLK_REQUEUE_REQUEST
ZFS_AC_KERNEL_BLK_RQ_BYTES
ZFS_AC_KERNEL_BLK_RQ_POS
ZFS_AC_KERNEL_BLK_RQ_SECTORS
ZFS_AC_KERNEL_GET_DISK_RO
ZFS_AC_KERNEL_RQ_IS_SYNC
ZFS_AC_KERNEL_RQ_FOR_EACH_SEGMENT
if test "$LINUX_OBJ" != "$LINUX"; then
KERNELMAKE_PARAMS="$KERNELMAKE_PARAMS O=$LINUX_OBJ"
fi
AC_SUBST(KERNELMAKE_PARAMS)
dnl # -Wall -fno-strict-aliasing -Wstrict-prototypes and other
dnl # compiler options are added by the kernel build system.
KERNELCPPFLAGS="$KERNELCPPFLAGS -DHAVE_SPL -D_KERNEL"
KERNELCPPFLAGS="$KERNELCPPFLAGS -DTEXT_DOMAIN=\\\"zfs-linux-kernel\\\""
AC_SUBST(KERNELCPPFLAGS)
])
dnl #
dnl # Detect name used for Module.symvers file in kernel
dnl #
AC_DEFUN([ZFS_AC_MODULE_SYMVERS], [
modpost=$LINUX/scripts/Makefile.modpost
AC_MSG_CHECKING([kernel file name for module symbols])
if test -f "$modpost"; then
if grep -q Modules.symvers $modpost; then
LINUX_SYMBOLS=Modules.symvers
else
LINUX_SYMBOLS=Module.symvers
fi
else
LINUX_SYMBOLS=NONE
fi
AC_MSG_RESULT($LINUX_SYMBOLS)
AC_SUBST(LINUX_SYMBOLS)
])
dnl #
dnl # Detect the kernel to be built against
dnl #
AC_DEFUN([ZFS_AC_KERNEL], [
AC_ARG_WITH([linux],
AS_HELP_STRING([--with-linux=PATH],
[Path to kernel source]),
[kernelsrc="$withval"])
AC_ARG_WITH(linux-obj,
AS_HELP_STRING([--with-linux-obj=PATH],
[Path to kernel build objects]),
[kernelbuild="$withval"])
AC_MSG_CHECKING([kernel source directory])
if test -z "$kernelsrc"; then
headersdir="/lib/modules/$(uname -r)/build"
if test -e "$headersdir"; then
sourcelink=$(readlink -f "$headersdir")
else
sourcelink=$(ls -1d /usr/src/kernels/* \
/usr/src/linux-* \
2>/dev/null | grep -v obj | tail -1)
fi
if test -n "$sourcelink" && test -e ${sourcelink}; then
kernelsrc=`readlink -f ${sourcelink}`
else
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([
*** Please make sure the kernel devel package for your distribution
*** is installed then try again. If that fails you can specify the
*** location of the kernel source with the '--with-linux=PATH' option.])
fi
else
if test "$kernelsrc" = "NONE"; then
kernsrcver=NONE
fi
fi
AC_MSG_RESULT([$kernelsrc])
AC_MSG_CHECKING([kernel build directory])
if test -z "$kernelbuild"; then
if test -d ${kernelsrc}-obj/${target_cpu}/${target_cpu}; then
kernelbuild=${kernelsrc}-obj/${target_cpu}/${target_cpu}
elif test -d ${kernelsrc}-obj/${target_cpu}/default; then
kernelbuild=${kernelsrc}-obj/${target_cpu}/default
elif test -d `dirname ${kernelsrc}`/build-${target_cpu}; then
kernelbuild=`dirname ${kernelsrc}`/build-${target_cpu}
else
kernelbuild=${kernelsrc}
fi
fi
AC_MSG_RESULT([$kernelbuild])
AC_MSG_CHECKING([kernel source version])
utsrelease1=$kernelbuild/include/linux/version.h
utsrelease2=$kernelbuild/include/linux/utsrelease.h
utsrelease3=$kernelbuild/include/generated/utsrelease.h
if test -r $utsrelease1 && fgrep -q UTS_RELEASE $utsrelease1; then
utsrelease=linux/version.h
elif test -r $utsrelease2 && fgrep -q UTS_RELEASE $utsrelease2; then
utsrelease=linux/utsrelease.h
elif test -r $utsrelease3 && fgrep -q UTS_RELEASE $utsrelease3; then
utsrelease=generated/utsrelease.h
fi
if test "$utsrelease"; then
kernsrcver=`(echo "#include <$utsrelease>";
echo "kernsrcver=UTS_RELEASE") |
cpp -I $kernelbuild/include |
grep "^kernsrcver=" | cut -d \" -f 2`
if test -z "$kernsrcver"; then
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([*** Cannot determine kernel version.])
fi
else
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([*** Cannot find UTS_RELEASE definition.])
fi
AC_MSG_RESULT([$kernsrcver])
LINUX=${kernelsrc}
LINUX_OBJ=${kernelbuild}
LINUX_VERSION=${kernsrcver}
AC_SUBST(LINUX)
AC_SUBST(LINUX_OBJ)
AC_SUBST(LINUX_VERSION)
ZFS_AC_MODULE_SYMVERS
])
dnl #
dnl # Detect name used for the additional SPL Module.symvers file. If one
dnl # does not exist this is likely because the SPL has been configured
dnl # but not built. To allow recursive builds a good guess is made as to
dnl # what this file will be named based on what it is named in the kernel
dnl # build products. This file will first be used at link time so if
dnl # the guess is wrong the build will fail then. This unfortunately
dnl # means the ZFS package does not contain a reliable mechanism to
dnl # detect symbols exported by the SPL at configure time.
dnl #
AC_DEFUN([ZFS_AC_SPL_MODULE_SYMVERS], [
AC_MSG_CHECKING([spl file name for module symbols])
if test -r $SPL_OBJ/Module.symvers; then
SPL_SYMBOLS=Module.symvers
elif test -r $SPL_OBJ/Modules.symvers; then
SPL_SYMBOLS=Modules.symvers
elif test -r $SPL_OBJ/module/Module.symvers; then
SPL_SYMBOLS=Module.symvers
elif test -r $SPL_OBJ/module/Modules.symvers; then
SPL_SYMBOLS=Modules.symvers
else
SPL_SYMBOLS=$LINUX_SYMBOLS
fi
AC_MSG_RESULT([$SPL_SYMBOLS])
AC_SUBST(SPL_SYMBOLS)
])
dnl #
dnl # Detect the SPL module to be built against
dnl #
AC_DEFUN([ZFS_AC_SPL], [
AC_ARG_WITH([spl],
AS_HELP_STRING([--with-spl=PATH],
[Path to spl source]),
[splsrc="$withval"])
AC_ARG_WITH([spl-obj],
AS_HELP_STRING([--with-spl-obj=PATH],
[Path to spl build objects]),
[splbuild="$withval"])
AC_MSG_CHECKING([spl source directory])
if test -z "$splsrc"; then
sourcelink=`ls -1d /usr/src/spl-*/${LINUX_VERSION} \
2>/dev/null | tail -1`
if test -z "$sourcelink" || test ! -e $sourcelink; then
sourcelink=../spl
fi
if test -e $sourcelink; then
splsrc=`readlink -f ${sourcelink}`
else
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([
*** Please make sure the spl devel package for your distribution
*** is installed then try again. If that fails you can specify the
*** location of the spl source with the '--with-spl=PATH' option.])
fi
else
if test "$splsrc" = "NONE"; then
splbuild=NONE
splsrcver=NONE
fi
fi
AC_MSG_RESULT([$splsrc])
AC_MSG_CHECKING([spl build directory])
if test -z "$splbuild"; then
splbuild=${splsrc}
fi
AC_MSG_RESULT([$splbuild])
AC_MSG_CHECKING([spl source version])
if test -r $splbuild/spl_config.h &&
fgrep -q SPL_META_VERSION $splbuild/spl_config.h; then
splsrcver=`(echo "#include <spl_config.h>";
echo "splsrcver=SPL_META_VERSION") |
cpp -I $splbuild |
grep "^splsrcver=" | cut -d \" -f 2`
fi
if test -z "$splsrcver"; then
AC_MSG_RESULT([Not found])
AC_MSG_ERROR([
*** Cannot determine the version of the spl source.
*** Please prepare the spl source before running this script])
fi
AC_MSG_RESULT([$splsrcver])
SPL=${splsrc}
SPL_OBJ=${splbuild}
SPL_VERSION=${splsrcver}
AC_SUBST(SPL)
AC_SUBST(SPL_OBJ)
AC_SUBST(SPL_VERSION)
ZFS_AC_SPL_MODULE_SYMVERS
])
dnl #
dnl # There are certain kernel build options which when enabled are
dnl # completely incompatible with non GPL kernel modules. It is best
dnl # to detect these at configure time and fail with a clear error
dnl # rather than build everything and fail during linking.
dnl #
dnl # CONFIG_DEBUG_LOCK_ALLOC - Maps mutex_lock() to mutex_lock_nested()
dnl #
AC_DEFUN([ZFS_AC_KERNEL_CONFIG], [
if test "$ZFS_META_LICENSE" = CDDL; then
ZFS_LINUX_CONFIG([DEBUG_LOCK_ALLOC],
AC_MSG_ERROR([
*** Kernel built with CONFIG_DEBUG_LOCK_ALLOC which is
*** incompatible with the CDDL license. You must rebuild
*** your kernel without this option.]), [])
fi
if test "$ZFS_META_LICENSE" = GPL; then
AC_DEFINE([HAVE_GPL_ONLY_SYMBOLS], [1],
[Define to 1 if licensed under the GPL])
fi
])
dnl #
dnl # ZFS_LINUX_CONFTEST
dnl #
AC_DEFUN([ZFS_LINUX_CONFTEST], [
cat confdefs.h - <<_ACEOF >conftest.c
$1
_ACEOF
])
dnl #
dnl # ZFS_LANG_PROGRAM(C)([PROLOGUE], [BODY])
dnl #
m4_define([ZFS_LANG_PROGRAM], [
$1
int
main (void)
{
dnl Do *not* indent the following line: there may be CPP directives.
dnl Don't move the `;' right after for the same reason.
$2
;
return 0;
}
])
dnl #
dnl # ZFS_LINUX_COMPILE_IFELSE / like AC_COMPILE_IFELSE
dnl #
AC_DEFUN([ZFS_LINUX_COMPILE_IFELSE], [
m4_ifvaln([$1], [ZFS_LINUX_CONFTEST([$1])])
rm -Rf build && mkdir -p build
echo "obj-m := conftest.o" >build/Makefile
AS_IF(
[AC_TRY_COMMAND(cp conftest.c build && make [$2] -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build) >/dev/null && AC_TRY_COMMAND([$3])],
[$4],
[_AC_MSG_LOG_CONFTEST m4_ifvaln([$5],[$5])]
)
rm -Rf build
])
dnl #
dnl # ZFS_LINUX_TRY_COMPILE like AC_TRY_COMPILE
dnl #
AC_DEFUN([ZFS_LINUX_TRY_COMPILE],
[ZFS_LINUX_COMPILE_IFELSE(
[AC_LANG_SOURCE([ZFS_LANG_PROGRAM([[$1]], [[$2]])])],
[modules],
[test -s build/conftest.o],
[$3], [$4])
])
dnl #
dnl # ZFS_LINUX_CONFIG
dnl #
AC_DEFUN([ZFS_LINUX_CONFIG],
[AC_MSG_CHECKING([whether Linux was built with CONFIG_$1])
ZFS_LINUX_TRY_COMPILE([
#ifndef AUTOCONF_INCLUDED
#include <linux/config.h>
#endif
],[
#ifndef CONFIG_$1
#error CONFIG_$1 not #defined
#endif
],[
AC_MSG_RESULT([yes])
$2
],[
AC_MSG_RESULT([no])
$3
])
])
dnl #
dnl # ZFS_CHECK_SYMBOL_EXPORT
dnl # check symbol exported or not
dnl #
AC_DEFUN([ZFS_CHECK_SYMBOL_EXPORT],
[AC_MSG_CHECKING([whether symbol $1 is exported])
grep -q -E '[[[:space:]]]$1[[[:space:]]]' \
$LINUX_OBJ/$LINUX_SYMBOLS 2>/dev/null
rc=$?
if test $rc -ne 0; then
export=0
for file in $2; do
grep -q -E "EXPORT_SYMBOL.*($1)" "$LINUX/$file" 2>/dev/null
rc=$?
if test $rc -eq 0; then
export=1
break;
fi
done
if test $export -eq 0; then
AC_MSG_RESULT([no])
$4
else
AC_MSG_RESULT([yes])
$3
fi
else
AC_MSG_RESULT([yes])
$3
fi
])