Add SEEK_DATA/SEEK_HOLE to lseek()/llseek()
[zfs.git] / config / kernel.m4
index a146a5f..7b8e3b0 100644 (file)
@@ -2,61 +2,599 @@ dnl #
 dnl # Default ZFS kernel configuration 
 dnl #
 AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
-       dnl # Kernel build make options
-       dnl # KERNELMAKE_PARAMS="V=1"   # Enable verbose module build
-       KERNELMAKE_PARAMS=
-
-       dnl # Kernel build cpp flags
-       KERNELCPPFLAGS="$KERNELCPPFLAGS -DHAVE_SPL -D_KERNEL "
-       KERNELCPPFLAGS="$KERNELCPPFLAGS -I$splsrc -I$splsrc/include -I$TOPDIR"
-
-       dnl # Required for pread() functionality an other GNU goodness
-       HOSTCFLAGS="$HOSTCFLAGS -ggdb -O2 -std=c99 "
-       HOSTCFLAGS="$HOSTCFLAGS -D_GNU_SOURCE -D__EXTENSIONS__ "
-
-       dnl # XXX: Quiet warnings not covered by the gcc-* patches
-       dnl # XXX: Remove once all the warnings are resolved
-       HOSTCFLAGS="$HOSTCFLAGS -Wno-switch -Wno-unused -Wno-missing-braces "
-       HOSTCFLAGS="$HOSTCFLAGS -Wno-parentheses "
-       HOSTCFLAGS="$HOSTCFLAGS -Wno-uninitialized -fno-strict-aliasing "
-
-       dnl # Expected defines not covered by zfs_config.h or spl_config.h
-       HOSTCFLAGS="$HOSTCFLAGS -DHAVE_SPL -D_POSIX_PTHREAD_SEMANTICS "
-       HOSTCFLAGS="$HOSTCFLAGS -D_FILE_OFFSET_BITS=64 "
-       HOSTCFLAGS="$HOSTCFLAGS -D_LARGEFILE64_SOURCE -D_REENTRANT "
-       HOSTCFLAGS="$HOSTCFLAGS -DTEXT_DOMAIN=\\\"zfs-linux-kernel\\\" "
-
-       dnl # Expected default include path
-       HOSTCFLAGS="$HOSTCFLAGS -I$TOPDIR "
-
-       if test "$kernelbuild" != "$kernelsrc"; then
-               KERNELMAKE_PARAMS="$KERNELMAKE_PARAMS O=$kernelbuild"
+       ZFS_AC_KERNEL
+       ZFS_AC_SPL
+       ZFS_AC_TEST_MODULE
+       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_3ARG_BLKDEV_GET
+       ZFS_AC_KERNEL_BLKDEV_GET_BY_PATH
+       ZFS_AC_KERNEL_OPEN_BDEV_EXCLUSIVE
+       ZFS_AC_KERNEL_LOOKUP_BDEV
+       ZFS_AC_KERNEL_INVALIDATE_BDEV_ARGS
+       ZFS_AC_KERNEL_BDEV_LOGICAL_BLOCK_SIZE
+       ZFS_AC_KERNEL_BDEV_PHYSICAL_BLOCK_SIZE
+       ZFS_AC_KERNEL_BIO_FAILFAST
+       ZFS_AC_KERNEL_BIO_FAILFAST_DTD
+       ZFS_AC_KERNEL_REQ_FAILFAST_MASK
+       ZFS_AC_KERNEL_BIO_END_IO_T_ARGS
+       ZFS_AC_KERNEL_BIO_RW_SYNC
+       ZFS_AC_KERNEL_BIO_RW_SYNCIO
+       ZFS_AC_KERNEL_REQ_SYNC
+       ZFS_AC_KERNEL_BLK_END_REQUEST
+       ZFS_AC_KERNEL_BLK_QUEUE_FLUSH
+       ZFS_AC_KERNEL_BLK_QUEUE_MAX_HW_SECTORS
+       ZFS_AC_KERNEL_BLK_QUEUE_MAX_SEGMENTS
+       ZFS_AC_KERNEL_BLK_QUEUE_PHYSICAL_BLOCK_SIZE
+       ZFS_AC_KERNEL_BLK_QUEUE_IO_OPT
+       ZFS_AC_KERNEL_BLK_QUEUE_NONROT
+       ZFS_AC_KERNEL_BLK_QUEUE_DISCARD
+       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_GET_GENDISK
+       ZFS_AC_KERNEL_RQ_IS_SYNC
+       ZFS_AC_KERNEL_RQ_FOR_EACH_SEGMENT
+       ZFS_AC_KERNEL_DISCARD_GRANULARITY
+       ZFS_AC_KERNEL_CONST_XATTR_HANDLER
+       ZFS_AC_KERNEL_XATTR_HANDLER_GET
+       ZFS_AC_KERNEL_XATTR_HANDLER_SET
+       ZFS_AC_KERNEL_SHOW_OPTIONS
+       ZFS_AC_KERNEL_FSYNC
+       ZFS_AC_KERNEL_EVICT_INODE
+       ZFS_AC_KERNEL_DIRTY_INODE_WITH_FLAGS
+       ZFS_AC_KERNEL_NR_CACHED_OBJECTS
+       ZFS_AC_KERNEL_FREE_CACHED_OBJECTS
+       ZFS_AC_KERNEL_FALLOCATE
+       ZFS_AC_KERNEL_MKDIR_UMODE_T
+       ZFS_AC_KERNEL_LOOKUP_NAMEIDATA
+       ZFS_AC_KERNEL_CREATE_NAMEIDATA
+       ZFS_AC_KERNEL_TRUNCATE_RANGE
+       ZFS_AC_KERNEL_AUTOMOUNT
+       ZFS_AC_KERNEL_ENCODE_FH_WITH_INODE
+       ZFS_AC_KERNEL_COMMIT_METADATA
+       ZFS_AC_KERNEL_CLEAR_INODE
+       ZFS_AC_KERNEL_INSERT_INODE_LOCKED
+       ZFS_AC_KERNEL_D_MAKE_ROOT
+       ZFS_AC_KERNEL_D_OBTAIN_ALIAS
+       ZFS_AC_KERNEL_D_SET_D_OP
+       ZFS_AC_KERNEL_D_REVALIDATE_NAMEIDATA
+       ZFS_AC_KERNEL_CONST_DENTRY_OPERATIONS
+       ZFS_AC_KERNEL_CHECK_DISK_SIZE_CHANGE
+       ZFS_AC_KERNEL_TRUNCATE_SETSIZE
+       ZFS_AC_KERNEL_6ARGS_SECURITY_INODE_INIT_SECURITY
+       ZFS_AC_KERNEL_CALLBACK_SECURITY_INODE_INIT_SECURITY
+       ZFS_AC_KERNEL_MOUNT_NODEV
+       ZFS_AC_KERNEL_SHRINK
+       ZFS_AC_KERNEL_S_D_OP
+       ZFS_AC_KERNEL_BDI
+       ZFS_AC_KERNEL_BDI_SETUP_AND_REGISTER
+       ZFS_AC_KERNEL_SET_NLINK
+       ZFS_AC_KERNEL_ELEVATOR_CHANGE
+       ZFS_AC_KERNEL_5ARG_SGET
+       ZFS_AC_KERNEL_LSEEK_EXECUTE
+
+       AS_IF([test "$LINUX_OBJ" != "$LINUX"], [
+               KERNELMAKE_PARAMS="$KERNELMAKE_PARAMS O=$LINUX_OBJ"
+       ])
+       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 $NO_UNUSED_BUT_SET_VARIABLE"
+       KERNELCPPFLAGS="$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])
+       AS_IF([test "x$enable_linux_builtin" != xyes -a -f "$modpost"], [
+               AS_IF([grep -q Modules.symvers $modpost], [
+                       LINUX_SYMBOLS=Modules.symvers
+               ], [
+                       LINUX_SYMBOLS=Module.symvers
+               ])
+
+               AS_IF([test ! -f "$LINUX_OBJ/$LINUX_SYMBOLS"], [
+                       AC_MSG_ERROR([
+       *** Please make sure the kernel devel package for your distribution
+       *** is installed.  If you are building with a custom kernel, make sure the
+       *** kernel is configured, built, and the '--with-linux=PATH' configure
+       *** option refers to the location of the kernel source.])
+               ])
+       ], [
+               LINUX_SYMBOLS=NONE
+       ])
+       AC_MSG_RESULT($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])
+       AS_IF([test -z "$kernelsrc"], [
+               AS_IF([test -e "/lib/modules/$(uname -r)/source"], [
+                       headersdir="/lib/modules/$(uname -r)/source"
+                       sourcelink=$(readlink -f "$headersdir")
+               ], [test -e "/lib/modules/$(uname -r)/build"], [
+                       headersdir="/lib/modules/$(uname -r)/build"
+                       sourcelink=$(readlink -f "$headersdir")
+               ], [
+                       sourcelink=$(ls -1d /usr/src/kernels/* \
+                                    /usr/src/linux-* \
+                                    2>/dev/null | grep -v obj | tail -1)
+               ])
+
+               AS_IF([test -n "$sourcelink" && test -e ${sourcelink}], [
+                       kernelsrc=`readlink -f ${sourcelink}`
+               ], [
+                       kernelsrc="[Not found]"
+               ])
+       ], [
+               AS_IF([test "$kernelsrc" = "NONE"], [
+                       kernsrcver=NONE
+               ])
+       ])
+
+       AC_MSG_RESULT([$kernelsrc])
+       AS_IF([test ! -d "$kernelsrc"], [
+               AC_MSG_ERROR([
+       *** Please make sure the kernel devel package for your distribution
+       *** is installed and then try again.  If that fails, you can specify the
+       *** location of the kernel source with the '--with-linux=PATH' option.])
+       ])
+
+       AC_MSG_CHECKING([kernel build directory])
+       AS_IF([test -z "$kernelbuild"], [
+               AS_IF([test -e "/lib/modules/$(uname -r)/build"], [
+                       kernelbuild=`readlink -f /lib/modules/$(uname -r)/build`
+               ], [test -d ${kernelsrc}-obj/${target_cpu}/${target_cpu}], [
+                       kernelbuild=${kernelsrc}-obj/${target_cpu}/${target_cpu}
+               ], [test -d ${kernelsrc}-obj/${target_cpu}/default], [
+                       kernelbuild=${kernelsrc}-obj/${target_cpu}/default
+               ], [test -d `dirname ${kernelsrc}`/build-${target_cpu}], [
+                       kernelbuild=`dirname ${kernelsrc}`/build-${target_cpu}
+               ], [
+                       kernelbuild=${kernelsrc}
+               ])
+       ])
+       AC_MSG_RESULT([$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
+       AS_IF([test -r $utsrelease1 && fgrep -q UTS_RELEASE $utsrelease1], [
+               utsrelease=linux/version.h
+       ], [test -r $utsrelease2 && fgrep -q UTS_RELEASE $utsrelease2], [
+               utsrelease=linux/utsrelease.h
+       ], [test -r $utsrelease3 && fgrep -q UTS_RELEASE $utsrelease3], [
+               utsrelease=generated/utsrelease.h
+       ])
+
+       AS_IF([test "$utsrelease"], [
+               kernsrcver=`(echo "#include <$utsrelease>";
+                            echo "kernsrcver=UTS_RELEASE") |
+                            cpp -I $kernelbuild/include |
+                            grep "^kernsrcver=" | cut -d \" -f 2`
+
+               AS_IF([test -z "$kernsrcver"], [
+                       AC_MSG_RESULT([Not found])
+                       AC_MSG_ERROR([*** Cannot determine kernel version.])
+               ])
+       ], [
+               AC_MSG_RESULT([Not found])
+               if test "x$enable_linux_builtin" != xyes; then
+                       AC_MSG_ERROR([*** Cannot find UTS_RELEASE definition.])
+               else
+                       AC_MSG_ERROR([
+       *** Cannot find UTS_RELEASE definition.
+       *** Please run 'make prepare' inside the kernel source tree.])
+               fi
+       ])
+
+       AC_MSG_RESULT([$kernsrcver])
+
+       LINUX=${kernelsrc}
+       LINUX_OBJ=${kernelbuild}
+       LINUX_VERSION=${kernsrcver}
+
+       AC_SUBST(LINUX)
+       AC_SUBST(LINUX_OBJ)
+       AC_SUBST(LINUX_VERSION)
+
+       ZFS_AC_MODULE_SYMVERS
+])
+
+
+dnl #
+dnl # Detect the SPL module to be built against
+dnl #
+AC_DEFUN([ZFS_AC_SPL], [
+       AC_ARG_WITH([spl],
+               AS_HELP_STRING([--with-spl=PATH],
+               [Path to spl source]),
+               [splsrc="$withval"])
+
+       AC_ARG_WITH([spl-obj],
+               AS_HELP_STRING([--with-spl-obj=PATH],
+               [Path to spl build objects]),
+               [splbuild="$withval"])
+
+       AC_ARG_WITH([spl-timeout],
+               AS_HELP_STRING([--with-spl-timeout=SECS],
+               [Wait SECS for SPL header and symver file @<:@default=0@:>@]),
+               [timeout="$withval"], [timeout=0])
+
+       dnl #
+       dnl # The existence of spl.release.in is used to identify a valid
+       dnl # source directory.  In order of preference:
+       dnl #
+       splsrc0="/var/lib/dkms/spl/${VERSION}/build"
+       splsrc1="/usr/src/spl-${VERSION}/${LINUX_VERSION}"
+       splsrc2="/usr/src/spl-${VERSION}"
+       splsrc3="../spl/"
+       splsrc4="$LINUX"
+
+       AC_MSG_CHECKING([spl source directory])
+       AS_IF([test -z "${splsrc}"], [
+               AS_IF([ test -e "${splsrc0}/spl.release.in"], [
+                       splsrc=${splsrc0}
+               ], [ test -e "${splsrc1}/spl.release.in"], [
+                       splsrc=${splsrc1}
+               ], [ test -e "${splsrc2}/spl.release.in"], [
+                       splsrc=${splsrc2}
+               ], [ test -e "${splsrc3}/spl.release.in"], [
+                       splsrc=$(readlink -f "${splsrc3}")
+               ], [ test -e "${splsrc4}/spl.release.in" ], [
+                       splsrc=${splsrc4}
+               ], [
+                       splsrc="[Not found]"
+               ])
+       ], [
+               AS_IF([test "$splsrc" = "NONE"], [
+                       splbuild=NONE
+                       splsrcver=NONE
+               ])
+       ])
+
+       AC_MSG_RESULT([$splsrc])
+       AS_IF([ test ! -e "$splsrc/spl.release.in"], [
+               AC_MSG_ERROR([
+       *** Please make sure the kmod 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.])
+       ])
+
+       dnl #
+       dnl # The existence of the spl_config.h is used to identify a valid
+       dnl # spl object directory.  In many cases the object and source
+       dnl # directory are the same, however the objects may also reside
+       dnl # is a subdirectory named after the kernel version.
+       dnl #
+       dnl # This file is supposed to be available after DKMS finishes
+       dnl # building the SPL kernel module for the target kernel.  The
+       dnl # '--with-spl-timeout' option can be passed to pause here,
+       dnl # waiting for the file to appear from a concurrently building
+       dnl # SPL package.
+       dnl #
+       AC_MSG_CHECKING([spl build directory])
+       while true; do
+               AS_IF([test -z "$splbuild"], [
+                       AS_IF([ test -e "${splsrc}/${LINUX_VERSION}/spl_config.h" ], [
+                               splbuild="${splsrc}/${LINUX_VERSION}"
+                       ], [ test -e "${splsrc}/spl_config.h" ], [
+                               splbuild="${splsrc}"
+                       ], [
+                               splbuild="[Not found]"
+                       ])
+               ])
+               AS_IF([test -e "$splbuild/spl_config.h" -o $timeout -le 0], [
+                       break;
+               ], [
+                       sleep 1
+                       timeout=$((timeout-1))
+               ])
+       done
+
+       AC_MSG_RESULT([$splbuild])
+       AS_IF([ ! test -e "$splbuild/spl_config.h"], [
+               AC_MSG_ERROR([
+       *** Please make sure the kmod spl devel <kernel> package for your
+       *** distribution is installed then try again.  If that fails you
+       *** can specify the location of the spl objects with the
+       *** '--with-spl-obj=PATH' option.])
+       ])
+
+       AC_MSG_CHECKING([spl source version])
+       AS_IF([test -r $splbuild/spl_config.h &&
+               fgrep -q SPL_META_VERSION $splbuild/spl_config.h], [
+
+               splsrcver=`(echo "#include <spl_config.h>";
+                           echo "splsrcver=SPL_META_VERSION-SPL_META_RELEASE") |
+                           cpp -I $splbuild |
+                           grep "^splsrcver=" | tr -d \" | cut -d= -f2`
+       ])
+
+       AS_IF([test -z "$splsrcver"], [
+               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])
+       ])
+
+       AC_MSG_RESULT([$splsrcver])
+
+       SPL=${splsrc}
+       SPL_OBJ=${splbuild}
+       SPL_VERSION=${splsrcver}
+
+       AC_SUBST(SPL)
+       AC_SUBST(SPL_OBJ)
+       AC_SUBST(SPL_VERSION)
+
+       dnl #
+       dnl # Detect the name used for the SPL Module.symvers file.  If one
+       dnl # does not exist this is likely because the SPL has been configured
+       dnl # but not built.  The '--with-spl-timeout' option can be passed
+       dnl # to pause here, waiting for the file to appear from a concurrently
+       dnl # building SPL package.  If the file does not appear in time, a good
+       dnl # guess is made as to what this file will be named based on what it
+       dnl # is named in the kernel build products.  This file will first be
+       dnl # used at link time so if the guess is wrong the build will fail
+       dnl # then.  This unfortunately means the ZFS package does not contain a
+       dnl # reliable mechanism to detect symbols exported by the SPL at
+       dnl # configure time.
+       dnl #
+       AC_MSG_CHECKING([spl file name for module symbols])
+       SPL_SYMBOLS=NONE
+
+       while true; do
+               AS_IF([test -r $SPL_OBJ/Module.symvers], [
+                       SPL_SYMBOLS=Module.symvers
+               ], [test -r $SPL_OBJ/Modules.symvers], [
+                       SPL_SYMBOLS=Modules.symvers
+               ], [test -r $SPL_OBJ/module/Module.symvers], [
+                       SPL_SYMBOLS=Module.symvers
+               ], [test -r $SPL_OBJ/module/Modules.symvers], [
+                       SPL_SYMBOLS=Modules.symvers
+               ])
+
+               AS_IF([test $SPL_SYMBOLS != NONE -o $timeout -le 0], [
+                       break;
+               ], [
+                       sleep 1
+                       timeout=$((timeout-1))
+               ])
+       done
+
+       AS_IF([test "$SPL_SYMBOLS" = NONE], [
+               SPL_SYMBOLS=$LINUX_SYMBOLS
+       ])
+
+       AC_MSG_RESULT([$SPL_SYMBOLS])
+       AC_SUBST(SPL_SYMBOLS)
+])
+
+dnl #
+dnl # Basic toolchain sanity check.
+dnl #
+AC_DEFUN([ZFS_AC_TEST_MODULE],
+       [AC_MSG_CHECKING([whether modules can be built])
+       ZFS_LINUX_TRY_COMPILE([],[],[
+               AC_MSG_RESULT([yes])
+       ],[
+               AC_MSG_RESULT([no])
+               if test "x$enable_linux_builtin" != xyes; then
+                       AC_MSG_ERROR([*** Unable to build an empty module.])
+               else
+                       AC_MSG_ERROR([
+       *** Unable to build an empty module.
+       *** Please run 'make scripts' inside the kernel source tree.])
+               fi
+       ])
+])
+
+dnl #
+dnl # Certain kernel build options are not supported.  These must be
+dnl # detected at configure time and cause a build failure.  Otherwise
+dnl # modules may be successfully built that behave incorrectly.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_CONFIG], [
+
+       AS_IF([test "$ZFS_META_LICENSE" = GPL], [
+               AC_DEFINE([HAVE_GPL_ONLY_SYMBOLS], [1],
+                       [Define to 1 if licensed under the GPL])
+       ])
+
+       ZFS_AC_KERNEL_CONFIG_DEBUG_LOCK_ALLOC
+])
+
+dnl #
+dnl # Check CONFIG_DEBUG_LOCK_ALLOC
+dnl #
+dnl # This is typically only set for debug kernels because it comes with
+dnl # a performance penalty.  However, when it is set it maps the non-GPL
+dnl # symbol mutex_lock() to the GPL-only mutex_lock_nested() symbol.
+dnl # This will cause a failure at link time which we'd rather know about
+dnl # at compile time.
+dnl #
+dnl # Since we plan to pursue making mutex_lock_nested() a non-GPL symbol
+dnl # with the upstream community we add a check to detect this case.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_CONFIG_DEBUG_LOCK_ALLOC], [
+
+       ZFS_LINUX_CONFIG([DEBUG_LOCK_ALLOC], [
+               AC_MSG_CHECKING([whether mutex_lock() is GPL-only])
+               tmp_flags="$EXTRA_KCFLAGS"
+               ZFS_LINUX_TRY_COMPILE([
+                       #include <linux/module.h>
+                       #include <linux/mutex.h>
+
+                       MODULE_LICENSE("$ZFS_META_LICENSE");
+               ],[
+                       struct mutex lock;
+
+                       mutex_init(&lock);
+                       mutex_lock(&lock);
+                       mutex_unlock(&lock);
+               ],[
+                       AC_MSG_RESULT(no)
+               ],[
+                       AC_MSG_RESULT(yes)
+                       AC_MSG_ERROR([
+       *** Kernel built with CONFIG_DEBUG_LOCK_ALLOC which is incompatible
+       *** with the CDDL license and will prevent the module linking stage
+       *** from succeeding.  You must rebuild your kernel without this
+       *** option enabled.])
+               ])
+               EXTRA_KCFLAGS="$tmp_flags"
+       ], [])
+])
+
+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([$1])])
+       rm -Rf build && mkdir -p build && touch build/conftest.mod.c
+       echo "obj-m := conftest.o" >build/Makefile
+       modpost_flag=''
+       test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
+       AS_IF(
+               [AC_TRY_COMMAND(cp conftest.c build && make [$2] -C $LINUX_OBJ EXTRA_CFLAGS="-Werror $EXTRA_KCFLAGS" $ARCH_UM M=$PWD/build $modpost_flag) >/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([
+               #include <linux/module.h>
+       ],[
+               #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], [
+       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 :
+                       $4
+               else :
+                       $3
+               fi
+       else :
+               $3
        fi
+])
 
-        AC_SUBST(KERNELMAKE_PARAMS)
-        AC_SUBST(KERNELCPPFLAGS)
-        AC_SUBST(HOSTCFLAGS)
-
-       dnl # XXX: I really, really hate this...  but to ensure the kernel
-       dnl # build system compiles C files shared between a library and a 
-       dnl # kernel module, we need to ensure each file has a unique make
-       dnl # target.  To do that I'm creating symlinks for each shared
-       dnl # file at configure time.  It may be possible something better
-       dnl # can be done in the Makefile but it will take some serious
-       dnl # investigation and I don't have the time now.
-
-       echo "creating symlinks for additional kernel make targets"
-       ln -f -s $LIBDIR/libport/u8_textprep.c      $LIBDIR/libport/ku8_textprep.c
-       ln -f -s $LIBDIR/libavl/avl.c               $LIBDIR/libavl/kavl.c
-       ln -f -s $LIBDIR/libavl/avl.c               $LIBDIR/libavl/uavl.c
-       ln -f -s $LIBDIR/libnvpair/nvpair.c         $LIBDIR/libnvpair/knvpair.c
-       ln -f -s $LIBDIR/libnvpair/nvpair.c         $LIBDIR/libnvpair/unvpair.c
-       ln -f -s $LIBDIR/libzcommon/zfs_deleg.c     $LIBDIR/libzcommon/kzfs_deleg.c
-       ln -f -s $LIBDIR/libzcommon/zfs_prop.c      $LIBDIR/libzcommon/kzfs_prop.c
-       ln -f -s $LIBDIR/libzcommon/zprop_common.c  $LIBDIR/libzcommon/kzprop_common.c
-       ln -f -s $LIBDIR/libzcommon/compress.c      $LIBDIR/libzcommon/kcompress.c
-       ln -f -s $LIBDIR/libzcommon/list.c          $LIBDIR/libzcommon/klist.c
-       ln -f -s $LIBDIR/libzcommon/zfs_namecheck.c $LIBDIR/libzcommon/kzfs_namecheck.c
-       ln -f -s $LIBDIR/libzcommon/zfs_comutil.c   $LIBDIR/libzcommon/kzfs_comutil.c
-       ln -f -s $LIBDIR/libzcommon/zpool_prop.c    $LIBDIR/libzcommon/kzpool_prop.c
+dnl #
+dnl # ZFS_LINUX_TRY_COMPILE_SYMBOL
+dnl # like ZFS_LINUX_TRY_COMPILE, except ZFS_CHECK_SYMBOL_EXPORT
+dnl # is called if not compiling for builtin
+dnl #
+AC_DEFUN([ZFS_LINUX_TRY_COMPILE_SYMBOL], [
+       ZFS_LINUX_TRY_COMPILE([$1], [$2], [rc=0], [rc=1])
+       if test $rc -ne 0; then :
+               $6
+       else
+               if test "x$enable_linux_builtin" != xyes; then
+                       ZFS_CHECK_SYMBOL_EXPORT([$3], [$4], [rc=0], [rc=1])
+               fi
+               if test $rc -ne 0; then :
+                       $6
+               else :
+                       $5
+               fi
+       fi
 ])