config/spl-build.m4

   1 ###############################################################################
   2 # Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3 # Copyright (C) 2007 The Regents of the University of California.
   4 # Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   5 ###############################################################################
   6 # SPL_AC_CONFIG_KERNEL: Default SPL kernel configuration.
   7 ###############################################################################
   8
   9 AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
  10         SPL_AC_KERNEL
  11         SPL_AC_KERNEL_CONFIG
  12
  13         if test "${LINUX_OBJ}" != "${LINUX}"; then
  14                 KERNELMAKE_PARAMS="$KERNELMAKE_PARAMS O=$LINUX_OBJ"
  15         fi
  16         AC_SUBST(KERNELMAKE_PARAMS)
  17
  18         KERNELCPPFLAGS="$KERNELCPPFLAGS -Wstrict-prototypes"
  19         AC_SUBST(KERNELCPPFLAGS)
  20
  21         SPL_AC_DEBUG
  22         SPL_AC_DEBUG_KMEM
  23         SPL_AC_DEBUG_KMEM_TRACKING
  24         SPL_AC_ATOMIC_SPINLOCK
  25         SPL_AC_TYPE_ATOMIC64_CMPXCHG
  26         SPL_AC_TYPE_ATOMIC64_XCHG
  27         SPL_AC_TYPE_UINTPTR_T
  28         SPL_AC_3ARGS_INIT_WORK
  29         SPL_AC_2ARGS_REGISTER_SYSCTL
  30         SPL_AC_SET_SHRINKER
  31         SPL_AC_3ARGS_SHRINKER_CALLBACK
  32         SPL_AC_PATH_IN_NAMEIDATA
  33         SPL_AC_TASK_CURR
  34         SPL_AC_CTL_UNNUMBERED
  35         SPL_AC_CTL_NAME
  36         SPL_AC_FLS64
  37         SPL_AC_DEVICE_CREATE
  38         SPL_AC_5ARGS_DEVICE_CREATE
  39         SPL_AC_CLASS_DEVICE_CREATE
  40         SPL_AC_SET_NORMALIZED_TIMESPEC_EXPORT
  41         SPL_AC_SET_NORMALIZED_TIMESPEC_INLINE
  42         SPL_AC_TIMESPEC_SUB
  43         SPL_AC_INIT_UTSNAME
  44         SPL_AC_FDTABLE_HEADER
  45         SPL_AC_FILES_FDTABLE
  46         SPL_AC_UACCESS_HEADER
  47         SPL_AC_KMALLOC_NODE
  48         SPL_AC_MONOTONIC_CLOCK
  49         SPL_AC_INODE_I_MUTEX
  50         SPL_AC_MUTEX_OWNER
  51         SPL_AC_MUTEX_LOCK_NESTED
  52         SPL_AC_3ARGS_ON_EACH_CPU
  53         SPL_AC_KALLSYMS_LOOKUP_NAME
  54         SPL_AC_GET_VMALLOC_INFO
  55         SPL_AC_PGDAT_HELPERS
  56         SPL_AC_FIRST_ONLINE_PGDAT
  57         SPL_AC_NEXT_ONLINE_PGDAT
  58         SPL_AC_NEXT_ZONE
  59         SPL_AC_PGDAT_LIST
  60         SPL_AC_GLOBAL_PAGE_STATE
  61         SPL_AC_ZONE_STAT_ITEM_FREE
  62         SPL_AC_ZONE_STAT_ITEM_INACTIVE
  63         SPL_AC_ZONE_STAT_ITEM_ACTIVE
  64         SPL_AC_GET_ZONE_COUNTS
  65         SPL_AC_USER_PATH_DIR
  66         SPL_AC_SET_FS_PWD
  67         SPL_AC_2ARGS_SET_FS_PWD
  68         SPL_AC_2ARGS_VFS_UNLINK
  69         SPL_AC_4ARGS_VFS_RENAME
  70         SPL_AC_FS_STRUCT_SPINLOCK
  71         SPL_AC_CRED_STRUCT
  72         SPL_AC_GROUPS_SEARCH
  73         SPL_AC_PUT_TASK_STRUCT
  74         SPL_AC_5ARGS_PROC_HANDLER
  75         SPL_AC_KVASPRINTF
  76         SPL_AC_3ARGS_FILE_FSYNC
  77         SPL_AC_EXPORTED_RWSEM_IS_LOCKED
  78         SPL_AC_KERNEL_INVALIDATE_INODES
  79         SPL_AC_KERNEL_2ARGS_INVALIDATE_INODES
  80         SPL_AC_SHRINK_DCACHE_MEMORY
  81         SPL_AC_SHRINK_ICACHE_MEMORY
  82         SPL_AC_KERN_PATH_PARENT
  83 ])
  84
  85 AC_DEFUN([SPL_AC_MODULE_SYMVERS], [
  86         modpost=$LINUX/scripts/Makefile.modpost
  87         AC_MSG_CHECKING([kernel file name for module symbols])
  88         if test -f "$modpost"; then
  89                 if grep -q Modules.symvers $modpost; then
  90                         LINUX_SYMBOLS=Modules.symvers
  91                 else
  92                         LINUX_SYMBOLS=Module.symvers
  93                 fi
  94
  95                 if ! test -f "$LINUX_OBJ/$LINUX_SYMBOLS"; then
  96                         AC_MSG_ERROR([
  97         *** Please make sure the kernel devel package for your distribution
  98         *** is installed.  If your building with a custom kernel make sure the
  99         *** kernel is configured, built, and the '--with-linux=PATH' configure
 100         *** option refers to the location of the kernel source.])
 101                 fi
 102         else
 103                 LINUX_SYMBOLS=NONE
 104         fi
 105         AC_MSG_RESULT($LINUX_SYMBOLS)
 106         AC_SUBST(LINUX_SYMBOLS)
 107 ])
 108
 109 AC_DEFUN([SPL_AC_KERNEL], [
 110         AC_ARG_WITH([linux],
 111                 AS_HELP_STRING([--with-linux=PATH],
 112                 [Path to kernel source]),
 113                 [kernelsrc="$withval"])
 114
 115         AC_ARG_WITH([linux-obj],
 116                 AS_HELP_STRING([--with-linux-obj=PATH],
 117                 [Path to kernel build objects]),
 118                 [kernelbuild="$withval"])
 119
 120         AC_MSG_CHECKING([kernel source directory])
 121         if test -z "$kernelsrc"; then
 122                 if test -e "/lib/modules/$(uname -r)/source"; then
 123                         headersdir="/lib/modules/$(uname -r)/source"
 124                         sourcelink=$(readlink -f "$headersdir")
 125                 elif test -e "/lib/modules/$(uname -r)/build"; then
 126                         headersdir="/lib/modules/$(uname -r)/build"
 127                         sourcelink=$(readlink -f "$headersdir")
 128                 else
 129                         sourcelink=$(ls -1d /usr/src/kernels/* \
 130                                      /usr/src/linux-* \
 131                                      2>/dev/null | grep -v obj | tail -1)
 132                 fi
 133
 134                 if test -n "$sourcelink" && test -e ${sourcelink}; then
 135                         kernelsrc=`readlink -f ${sourcelink}`
 136                 else
 137                         AC_MSG_RESULT([Not found])
 138                         AC_MSG_ERROR([
 139         *** Please make sure the kernel devel package for your distribution
 140         *** is installed then try again.  If that fails you can specify the
 141         *** location of the kernel source with the '--with-linux=PATH' option.])
 142                 fi
 143         else
 144                 if test "$kernelsrc" = "NONE"; then
 145                         kernsrcver=NONE
 146                 fi
 147         fi
 148
 149         AC_MSG_RESULT([$kernelsrc])
 150         AC_MSG_CHECKING([kernel build directory])
 151         if test -z "$kernelbuild"; then
 152                 if test -e "/lib/modules/$(uname -r)/build"; then
 153                         kernelbuild=`readlink -f /lib/modules/$(uname -r)/build`
 154                 elif test -d ${kernelsrc}-obj/${target_cpu}/${target_cpu}; then
 155                         kernelbuild=${kernelsrc}-obj/${target_cpu}/${target_cpu}
 156                 elif test -d ${kernelsrc}-obj/${target_cpu}/default; then
 157                         kernelbuild=${kernelsrc}-obj/${target_cpu}/default
 158                 elif test -d `dirname ${kernelsrc}`/build-${target_cpu}; then
 159                         kernelbuild=`dirname ${kernelsrc}`/build-${target_cpu}
 160                 else
 161                         kernelbuild=${kernelsrc}
 162                 fi
 163         fi
 164         AC_MSG_RESULT([$kernelbuild])
 165
 166         AC_MSG_CHECKING([kernel source version])
 167         utsrelease1=$kernelbuild/include/linux/version.h
 168         utsrelease2=$kernelbuild/include/linux/utsrelease.h
 169         utsrelease3=$kernelbuild/include/generated/utsrelease.h
 170         if test -r $utsrelease1 && fgrep -q UTS_RELEASE $utsrelease1; then
 171                 utsrelease=linux/version.h
 172         elif test -r $utsrelease2 && fgrep -q UTS_RELEASE $utsrelease2; then
 173                 utsrelease=linux/utsrelease.h
 174         elif test -r $utsrelease3 && fgrep -q UTS_RELEASE $utsrelease3; then
 175                 utsrelease=generated/utsrelease.h
 176         fi
 177
 178         if test "$utsrelease"; then
 179                 kernsrcver=`(echo "#include <$utsrelease>";
 180                              echo "kernsrcver=UTS_RELEASE") |
 181                              cpp -I $kernelbuild/include |
 182                              grep "^kernsrcver=" | cut -d \" -f 2`
 183
 184                 if test -z "$kernsrcver"; then
 185                         AC_MSG_RESULT([Not found])
 186                         AC_MSG_ERROR([*** Cannot determine kernel version.])
 187                 fi
 188         else
 189                 AC_MSG_RESULT([Not found])
 190                 AC_MSG_ERROR([*** Cannot find UTS_RELEASE definition.])
 191         fi
 192
 193         AC_MSG_RESULT([$kernsrcver])
 194
 195         LINUX=${kernelsrc}
 196         LINUX_OBJ=${kernelbuild}
 197         LINUX_VERSION=${kernsrcver}
 198
 199         AC_SUBST(LINUX)
 200         AC_SUBST(LINUX_OBJ)
 201         AC_SUBST(LINUX_VERSION)
 202
 203         SPL_AC_MODULE_SYMVERS
 204 ])
 205
 206 AC_DEFUN([SPL_AC_KERNEL_CONFIG], [
 207         SPL_LINUX_CONFIG([PREEMPT],
 208                 AC_MSG_ERROR([
 209                 *** Kernel built with CONFIG_PREEMPT which is not supported.
 210                 ** You must rebuild your kernel without this option.]), [])
 211 ])
 212
 213 dnl #
 214 dnl # Explicitly check for gawk, we require it for the the usermode
 215 dnl # helper.  For some reason the standard awk command does not
 216 dnl # behave correctly when invoked from the usermode helper.
 217 dnl #
 218 AC_DEFUN([SPL_AC_GAWK], [
 219         AS_IF([test "x$AWK" != xgawk], [
 220                 AC_MSG_ERROR([
 221         *** Required util gawk missing.  Please install the required
 222         *** gawk package for your distribution and try again.])
 223         ])
 224 ])
 225
 226 dnl #
 227 dnl # Default SPL user configuration
 228 dnl #
 229 AC_DEFUN([SPL_AC_CONFIG_USER], [
 230         SPL_AC_GAWK
 231 ])
 232
 233 dnl #
 234 dnl # Check for rpm+rpmbuild to build RPM packages.  If these tools
 235 dnl # are missing it is non-fatal but you will not be able to build
 236 dnl # RPM packages and will be warned if you try too.
 237 dnl #
 238 AC_DEFUN([SPL_AC_RPM], [
 239         RPM=rpm
 240         RPMBUILD=rpmbuild
 241
 242         AC_MSG_CHECKING([whether $RPM is available])
 243         AS_IF([tmp=$($RPM --version 2>/dev/null)], [
 244                 RPM_VERSION=$(echo $tmp | $AWK '/RPM/ { print $[3] }')
 245                 HAVE_RPM=yes
 246                 AC_MSG_RESULT([$HAVE_RPM ($RPM_VERSION)])
 247         ],[
 248                 HAVE_RPM=no
 249                 AC_MSG_RESULT([$HAVE_RPM])
 250         ])
 251
 252         AC_MSG_CHECKING([whether $RPMBUILD is available])
 253         AS_IF([tmp=$($RPMBUILD --version 2>/dev/null)], [
 254                 RPMBUILD_VERSION=$(echo $tmp | $AWK '/RPM/ { print $[3] }')
 255                 HAVE_RPMBUILD=yes
 256                 AC_MSG_RESULT([$HAVE_RPMBUILD ($RPMBUILD_VERSION)])
 257         ],[
 258                 HAVE_RPMBUILD=no
 259                 AC_MSG_RESULT([$HAVE_RPMBUILD])
 260         ])
 261
 262         AC_SUBST(HAVE_RPM)
 263         AC_SUBST(RPM)
 264         AC_SUBST(RPM_VERSION)
 265
 266         AC_SUBST(HAVE_RPMBUILD)
 267         AC_SUBST(RPMBUILD)
 268         AC_SUBST(RPMBUILD_VERSION)
 269 ])
 270
 271 dnl #
 272 dnl # Check for dpkg+dpkg-buildpackage to build DEB packages.  If these
 273 dnl # tools are missing it is non-fatal but you will not be able to build
 274 dnl # DEB packages and will be warned if you try too.
 275 dnl #
 276 AC_DEFUN([SPL_AC_DPKG], [
 277         DPKG=dpkg
 278         DPKGBUILD=dpkg-buildpackage
 279
 280         AC_MSG_CHECKING([whether $DPKG is available])
 281         AS_IF([tmp=$($DPKG --version 2>/dev/null)], [
 282                 DPKG_VERSION=$(echo $tmp | $AWK '/Debian/ { print $[7] }')
 283                 HAVE_DPKG=yes
 284                 AC_MSG_RESULT([$HAVE_DPKG ($DPKG_VERSION)])
 285         ],[
 286                 HAVE_DPKG=no
 287                 AC_MSG_RESULT([$HAVE_DPKG])
 288         ])
 289
 290         AC_MSG_CHECKING([whether $DPKGBUILD is available])
 291         AS_IF([tmp=$($DPKGBUILD --version 2>/dev/null)], [
 292                 DPKGBUILD_VERSION=$(echo $tmp | \
 293                     $AWK '/Debian/ { print $[4] }' | cut -f-4 -d'.')
 294                 HAVE_DPKGBUILD=yes
 295                 AC_MSG_RESULT([$HAVE_DPKGBUILD ($DPKGBUILD_VERSION)])
 296         ],[
 297                 HAVE_DPKGBUILD=no
 298                 AC_MSG_RESULT([$HAVE_DPKGBUILD])
 299         ])
 300
 301         AC_SUBST(HAVE_DPKG)
 302         AC_SUBST(DPKG)
 303         AC_SUBST(DPKG_VERSION)
 304
 305         AC_SUBST(HAVE_DPKGBUILD)
 306         AC_SUBST(DPKGBUILD)
 307         AC_SUBST(DPKGBUILD_VERSION)
 308 ])
 309
 310 dnl #
 311 dnl # Until native packaging for various different packing systems
 312 dnl # can be added the least we can do is attempt to use alien to
 313 dnl # convert the RPM packages to the needed package type.  This is
 314 dnl # a hack but so far it has worked reasonable well.
 315 dnl #
 316 AC_DEFUN([SPL_AC_ALIEN], [
 317         ALIEN=alien
 318
 319         AC_MSG_CHECKING([whether $ALIEN is available])
 320         AS_IF([tmp=$($ALIEN --version 2>/dev/null)], [
 321                 ALIEN_VERSION=$(echo $tmp | $AWK '{ print $[3] }')
 322                 HAVE_ALIEN=yes
 323                 AC_MSG_RESULT([$HAVE_ALIEN ($ALIEN_VERSION)])
 324         ],[
 325                 HAVE_ALIEN=no
 326                 AC_MSG_RESULT([$HAVE_ALIEN])
 327         ])
 328
 329         AC_SUBST(HAVE_ALIEN)
 330         AC_SUBST(ALIEN)
 331         AC_SUBST(ALIEN_VERSION)
 332 ])
 333
 334 dnl #
 335 dnl # Using the VENDOR tag from config.guess set the default
 336 dnl # package type for 'make pkg': (rpm | deb | tgz)
 337 dnl #
 338 AC_DEFUN([SPL_AC_DEFAULT_PACKAGE], [
 339         AC_MSG_CHECKING([linux distribution])
 340         if test -f /etc/redhat-release ; then
 341                 VENDOR=redhat ;
 342         elif test -f /etc/fedora-release ; then
 343                 VENDOR=fedora ;
 344         elif test -f /etc/lsb-release ; then
 345                 VENDOR=ubuntu ;
 346         elif test -f /etc/debian_version ; then
 347                 VENDOR=debian ;
 348         elif test -f /etc/SuSE-release ; then
 349                 VENDOR=sles ;
 350         elif test -f /etc/slackware-version ; then
 351                 VENDOR=slackware ;
 352         elif test -f /etc/gentoo-release ; then
 353                 VENDOR=gentoo ;
 354         else
 355                 VENDOR= ;
 356         fi
 357         AC_MSG_RESULT([$VENDOR])
 358         AC_SUBST(VENDOR)
 359
 360         AC_MSG_CHECKING([default package type])
 361         case "$VENDOR" in
 362                 fedora)     DEFAULT_PACKAGE=rpm ;;
 363                 redhat)     DEFAULT_PACKAGE=rpm ;;
 364                 sles)       DEFAULT_PACKAGE=rpm ;;
 365                 ubuntu)     DEFAULT_PACKAGE=deb ;;
 366                 debian)     DEFAULT_PACKAGE=deb ;;
 367                 slackware)  DEFAULT_PACKAGE=tgz ;;
 368                 *)          DEFAULT_PACKAGE=rpm ;;
 369         esac
 370
 371         AC_MSG_RESULT([$DEFAULT_PACKAGE])
 372         AC_SUBST(DEFAULT_PACKAGE)
 373 ])
 374
 375 dnl #
 376 dnl # Default SPL user configuration
 377 dnl #
 378 AC_DEFUN([SPL_AC_PACKAGE], [
 379         SPL_AC_RPM
 380         SPL_AC_DPKG
 381         SPL_AC_ALIEN
 382         SPL_AC_DEFAULT_PACKAGE
 383 ])
 384
 385 AC_DEFUN([SPL_AC_LICENSE], [
 386         AC_MSG_CHECKING([spl license])
 387         LICENSE=GPL
 388         AC_MSG_RESULT([$LICENSE])
 389         KERNELCPPFLAGS="${KERNELCPPFLAGS} -DHAVE_GPL_ONLY_SYMBOLS"
 390         AC_SUBST(LICENSE)
 391 ])
 392
 393 AC_DEFUN([SPL_AC_CONFIG], [
 394         SPL_CONFIG=all
 395         AC_ARG_WITH([config],
 396                 AS_HELP_STRING([--with-config=CONFIG],
 397                 [Config file 'kernel|user|all|srpm']),
 398                 [SPL_CONFIG="$withval"])
 399
 400         AC_MSG_CHECKING([spl config])
 401         AC_MSG_RESULT([$SPL_CONFIG]);
 402         AC_SUBST(SPL_CONFIG)
 403
 404         case "$SPL_CONFIG" in
 405                 kernel) SPL_AC_CONFIG_KERNEL ;;
 406                 user)   SPL_AC_CONFIG_USER   ;;
 407                 all)    SPL_AC_CONFIG_KERNEL
 408                         SPL_AC_CONFIG_USER   ;;
 409                 srpm)                        ;;
 410                 *)
 411                 AC_MSG_RESULT([Error!])
 412                 AC_MSG_ERROR([Bad value "$SPL_CONFIG" for --with-config,
 413                               user kernel|user|all|srpm]) ;;
 414         esac
 415
 416         AM_CONDITIONAL([CONFIG_USER],
 417                        [test "$SPL_CONFIG" = user] ||
 418                        [test "$SPL_CONFIG" = all])
 419         AM_CONDITIONAL([CONFIG_KERNEL],
 420                        [test "$SPL_CONFIG" = kernel] ||
 421                        [test "$SPL_CONFIG" = all])
 422 ])
 423
 424 dnl #
 425 dnl # Enable if the SPL should be compiled with internal debugging enabled.
 426 dnl # By default this support is disabled.
 427 dnl #
 428 AC_DEFUN([SPL_AC_DEBUG], [
 429         AC_MSG_CHECKING([whether debugging is enabled])
 430         AC_ARG_ENABLE([debug],
 431                 [AS_HELP_STRING([--enable-debug],
 432                 [Enable generic debug support @<:@default=no@:>@])],
 433                 [],
 434                 [enable_debug=no])
 435
 436         AS_IF([test "x$enable_debug" = xyes],
 437         [
 438                 KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG -Werror"
 439                 DEBUG_CFLAGS="-DDEBUG -Werror"
 440         ],
 441         [
 442                 KERNELCPPFLAGS="${KERNELCPPFLAGS} -DNDEBUG"
 443                 DEBUG_CFLAGS="-DNDEBUG"
 444         ])
 445
 446         AC_SUBST(DEBUG_CFLAGS)
 447         AC_MSG_RESULT([$enable_debug])
 448 ])
 449
 450 dnl #
 451 dnl # Enabled by default it provides a minimal level of memory tracking.
 452 dnl # A total count of bytes allocated is kept for each alloc and free.
 453 dnl # Then at module unload time a report to the console will be printed
 454 dnl # if memory was leaked.  Additionally, /proc/spl/kmem/slab will exist
 455 dnl # and provide an easy way to inspect the kmem based slab.
 456 dnl #
 457 AC_DEFUN([SPL_AC_DEBUG_KMEM], [
 458         AC_ARG_ENABLE([debug-kmem],
 459                 [AS_HELP_STRING([--enable-debug-kmem],
 460                 [Enable basic kmem accounting @<:@default=yes@:>@])],
 461                 [],
 462                 [enable_debug_kmem=yes])
 463
 464         AS_IF([test "x$enable_debug_kmem" = xyes],
 465                 [AC_DEFINE([DEBUG_KMEM], [1],
 466                 [Define to 1 to enable basic kmem accounting])
 467                 KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG_KMEM"])
 468
 469         AC_MSG_CHECKING([whether basic kmem accounting is enabled])
 470         AC_MSG_RESULT([$enable_debug_kmem])
 471 ])
 472
 473 dnl #
 474 dnl # Disabled by default it provides detailed memory tracking.  This
 475 dnl # feature also requires --enable-debug-kmem to be set.  When enabled
 476 dnl # not only will total bytes be tracked but also the location of every
 477 dnl # alloc and free.  When the SPL module is unloaded a list of all leaked
 478 dnl # addresses and where they were allocated will be dumped to the console.
 479 dnl # Enabling this feature has a significant impact on performance but it
 480 dnl # makes finding memory leaks pretty straight forward.
 481 dnl #
 482 AC_DEFUN([SPL_AC_DEBUG_KMEM_TRACKING], [
 483         AC_ARG_ENABLE([debug-kmem-tracking],
 484                 [AS_HELP_STRING([--enable-debug-kmem-tracking],
 485                 [Enable detailed kmem tracking  @<:@default=no@:>@])],
 486                 [],
 487                 [enable_debug_kmem_tracking=no])
 488
 489         AS_IF([test "x$enable_debug_kmem_tracking" = xyes],
 490                 [AC_DEFINE([DEBUG_KMEM_TRACKING], [1],
 491                 [Define to 1 to enable detailed kmem tracking])
 492                 KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG_KMEM_TRACKING"])
 493
 494         AC_MSG_CHECKING([whether detailed kmem tracking is enabled])
 495         AC_MSG_RESULT([$enable_debug_kmem_tracking])
 496 ])
 497
 498 dnl #
 499 dnl # SPL_LINUX_CONFTEST
 500 dnl #
 501 AC_DEFUN([SPL_LINUX_CONFTEST], [
 502 cat confdefs.h - <<_ACEOF >conftest.c
 503 $1
 504 _ACEOF
 505 ])
 506
 507 dnl #
 508 dnl # SPL_LANG_PROGRAM(C)([PROLOGUE], [BODY])
 509 dnl #
 510 m4_define([SPL_LANG_PROGRAM], [
 511 $1
 512 int
 513 main (void)
 514 {
 515 dnl Do *not* indent the following line: there may be CPP directives.
 516 dnl Don't move the `;' right after for the same reason.
 517 $2
 518   ;
 519   return 0;
 520 }
 521 ])
 522
 523 dnl #
 524 dnl # SPL_LINUX_COMPILE_IFELSE / like AC_COMPILE_IFELSE
 525 dnl #
 526 AC_DEFUN([SPL_LINUX_COMPILE_IFELSE], [
 527         m4_ifvaln([$1], [SPL_LINUX_CONFTEST([$1])])
 528         rm -Rf build && mkdir -p build
 529         echo "obj-m := conftest.o" >build/Makefile
 530         AS_IF(
 531                 [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])],
 532                 [$4],
 533                 [_AC_MSG_LOG_CONFTEST m4_ifvaln([$5],[$5])]
 534         )
 535         rm -Rf build
 536 ])
 537
 538 dnl #
 539 dnl # SPL_LINUX_TRY_COMPILE like AC_TRY_COMPILE
 540 dnl #
 541 AC_DEFUN([SPL_LINUX_TRY_COMPILE],
 542         [SPL_LINUX_COMPILE_IFELSE(
 543         [AC_LANG_SOURCE([SPL_LANG_PROGRAM([[$1]], [[$2]])])],
 544         [modules],
 545         [test -s build/conftest.o],
 546         [$3], [$4])
 547 ])
 548
 549 dnl #
 550 dnl # SPL_LINUX_CONFIG
 551 dnl #
 552 AC_DEFUN([SPL_LINUX_CONFIG],
 553         [AC_MSG_CHECKING([whether Linux was built with CONFIG_$1])
 554         SPL_LINUX_TRY_COMPILE([
 555                 #ifndef AUTOCONF_INCLUDED
 556                 #include <linux/config.h>
 557                 #endif
 558         ],[
 559                 #ifndef CONFIG_$1
 560                 #error CONFIG_$1 not #defined
 561                 #endif
 562         ],[
 563                 AC_MSG_RESULT([yes])
 564                 $2
 565         ],[
 566                 AC_MSG_RESULT([no])
 567                 $3
 568         ])
 569 ])
 570
 571 dnl #
 572 dnl # SPL_CHECK_SYMBOL_EXPORT
 573 dnl # check symbol exported or not
 574 dnl #
 575 AC_DEFUN([SPL_CHECK_SYMBOL_EXPORT],
 576         [AC_MSG_CHECKING([whether symbol $1 is exported])
 577         grep -q -E '[[[:space:]]]$1[[[:space:]]]' \
 578                 $LINUX_OBJ/Module*.symvers 2>/dev/null
 579         rc=$?
 580         if test $rc -ne 0; then
 581                 export=0
 582                 for file in $2; do
 583                         grep -q -E "EXPORT_SYMBOL.*($1)" \
 584                                 "$LINUX_OBJ/$file" 2>/dev/null
 585                         rc=$?
 586                         if test $rc -eq 0; then
 587                                 export=1
 588                                 break;
 589                         fi
 590                 done
 591                 if test $export -eq 0; then
 592                         AC_MSG_RESULT([no])
 593                         $4
 594                 else
 595                         AC_MSG_RESULT([yes])
 596                         $3
 597                 fi
 598         else
 599                 AC_MSG_RESULT([yes])
 600                 $3
 601         fi
 602 ])
 603
 604 dnl #
 605 dnl # SPL_CHECK_HEADER
 606 dnl # check whether header exists and define HAVE_$2_HEADER
 607 dnl #
 608 AC_DEFUN([SPL_CHECK_HEADER],
 609         [AC_MSG_CHECKING([whether header $1 exists])
 610         SPL_LINUX_TRY_COMPILE([
 611                 #include <$1>
 612         ],[
 613                 return 0;
 614         ],[
 615                 AC_DEFINE(HAVE_$2_HEADER, 1, [$1 exists])
 616                 AC_MSG_RESULT(yes)
 617                 $3
 618         ],[
 619                 AC_MSG_RESULT(no)
 620                 $4
 621         ])
 622 ])
 623
 624 dnl #
 625 dnl # Use the atomic implemenation based on global spinlocks.  This
 626 dnl # should only be needed by 32-bit kernels which do not provide
 627 dnl # the atomic64_* API.  It may be optionally enabled as a fallback
 628 dnl # if problems are observed with the direct mapping to the native
 629 dnl # Linux atomic operations.  You may not disable atomic spinlocks
 630 dnl # if you kernel does not an atomic64_* API.
 631 dnl #
 632 AC_DEFUN([SPL_AC_ATOMIC_SPINLOCK], [
 633         AC_ARG_ENABLE([atomic-spinlocks],
 634                 [AS_HELP_STRING([--enable-atomic-spinlocks],
 635                 [Atomic types use spinlocks @<:@default=check@:>@])],
 636                 [],
 637                 [enable_atomic_spinlocks=check])
 638
 639         SPL_LINUX_TRY_COMPILE([
 640                 #include <asm/atomic.h>
 641         ],[
 642                 atomic64_t *ptr __attribute__ ((unused));
 643         ],[
 644                 have_atomic64_t=yes
 645                 AC_DEFINE(HAVE_ATOMIC64_T, 1,
 646                         [kernel defines atomic64_t])
 647         ],[
 648                 have_atomic64_t=no
 649         ])
 650
 651         AS_IF([test "x$enable_atomic_spinlocks" = xcheck], [
 652                 AS_IF([test "x$have_atomic64_t" = xyes], [
 653                         enable_atomic_spinlocks=no
 654                 ],[
 655                         enable_atomic_spinlocks=yes
 656                 ])
 657         ])
 658
 659         AS_IF([test "x$enable_atomic_spinlocks" = xyes], [
 660                 AC_DEFINE([ATOMIC_SPINLOCK], [1],
 661                         [Atomic types use spinlocks])
 662         ],[
 663                 AS_IF([test "x$have_atomic64_t" = xno], [
 664                         AC_MSG_FAILURE(
 665                         [--disable-atomic-spinlocks given but required atomic64 support is unavailable])
 666                 ])
 667         ])
 668
 669         AC_MSG_CHECKING([whether atomic types use spinlocks])
 670         AC_MSG_RESULT([$enable_atomic_spinlocks])
 671
 672         AC_MSG_CHECKING([whether kernel defines atomic64_t])
 673         AC_MSG_RESULT([$have_atomic64_t])
 674 ])
 675
 676 dnl #
 677 dnl # 2.6.24 API change,
 678 dnl # check if atomic64_cmpxchg is defined
 679 dnl #
 680 AC_DEFUN([SPL_AC_TYPE_ATOMIC64_CMPXCHG],
 681         [AC_MSG_CHECKING([whether kernel defines atomic64_cmpxchg])
 682         SPL_LINUX_TRY_COMPILE([
 683                 #include <asm/atomic.h>
 684                 #include <asm/system.h>
 685         ],[
 686                 atomic64_cmpxchg((atomic64_t *)NULL, 0, 0);
 687         ],[
 688                 AC_MSG_RESULT([yes])
 689                 AC_DEFINE(HAVE_ATOMIC64_CMPXCHG, 1,
 690                           [kernel defines atomic64_cmpxchg])
 691         ],[
 692                 AC_MSG_RESULT([no])
 693         ])
 694 ])
 695
 696 dnl #
 697 dnl # 2.6.24 API change,
 698 dnl # check if atomic64_xchg is defined
 699 dnl #
 700 AC_DEFUN([SPL_AC_TYPE_ATOMIC64_XCHG],
 701         [AC_MSG_CHECKING([whether kernel defines atomic64_xchg])
 702         SPL_LINUX_TRY_COMPILE([
 703                 #include <asm/atomic.h>
 704         ],[
 705                 atomic64_xchg((atomic64_t *)NULL, 0);
 706         ],[
 707                 AC_MSG_RESULT([yes])
 708                 AC_DEFINE(HAVE_ATOMIC64_XCHG, 1,
 709                           [kernel defines atomic64_xchg])
 710         ],[
 711                 AC_MSG_RESULT([no])
 712         ])
 713 ])
 714
 715 dnl #
 716 dnl # 2.6.24 API change,
 717 dnl # check if uintptr_t typedef is defined
 718 dnl #
 719 AC_DEFUN([SPL_AC_TYPE_UINTPTR_T],
 720         [AC_MSG_CHECKING([whether kernel defines uintptr_t])
 721         SPL_LINUX_TRY_COMPILE([
 722                 #include <linux/types.h>
 723         ],[
 724                 uintptr_t *ptr __attribute__ ((unused));
 725         ],[
 726                 AC_MSG_RESULT([yes])
 727                 AC_DEFINE(HAVE_UINTPTR_T, 1,
 728                           [kernel defines uintptr_t])
 729         ],[
 730                 AC_MSG_RESULT([no])
 731         ])
 732 ])
 733
 734 dnl #
 735 dnl # 2.6.20 API change,
 736 dnl # INIT_WORK use 2 args and not store data inside
 737 dnl #
 738 AC_DEFUN([SPL_AC_3ARGS_INIT_WORK],
 739         [AC_MSG_CHECKING([whether INIT_WORK wants 3 args])
 740         SPL_LINUX_TRY_COMPILE([
 741                 #include <linux/workqueue.h>
 742         ],[
 743                 struct work_struct work __attribute__ ((unused));
 744                 INIT_WORK(&work, NULL, NULL);
 745         ],[
 746                 AC_MSG_RESULT(yes)
 747                 AC_DEFINE(HAVE_3ARGS_INIT_WORK, 1,
 748                           [INIT_WORK wants 3 args])
 749         ],[
 750                 AC_MSG_RESULT(no)
 751         ])
 752 ])
 753
 754 dnl #
 755 dnl # 2.6.21 API change,
 756 dnl # 'register_sysctl_table' use only one argument instead of two
 757 dnl #
 758 AC_DEFUN([SPL_AC_2ARGS_REGISTER_SYSCTL],
 759         [AC_MSG_CHECKING([whether register_sysctl_table() wants 2 args])
 760         SPL_LINUX_TRY_COMPILE([
 761                 #include <linux/sysctl.h>
 762         ],[
 763                 (void) register_sysctl_table(NULL, 0);
 764         ],[
 765                 AC_MSG_RESULT(yes)
 766                 AC_DEFINE(HAVE_2ARGS_REGISTER_SYSCTL, 1,
 767                           [register_sysctl_table() wants 2 args])
 768         ],[
 769                 AC_MSG_RESULT(no)
 770         ])
 771 ])
 772
 773 dnl #
 774 dnl # 2.6.23 API change
 775 dnl # Old set_shrinker API replaced with register_shrinker
 776 dnl #
 777 AC_DEFUN([SPL_AC_SET_SHRINKER], [
 778         AC_MSG_CHECKING([whether set_shrinker() available])
 779         SPL_LINUX_TRY_COMPILE([
 780                 #include <linux/mm.h>
 781         ],[
 782                 return set_shrinker(DEFAULT_SEEKS, NULL);
 783         ],[
 784                 AC_MSG_RESULT([yes])
 785                 AC_DEFINE(HAVE_SET_SHRINKER, 1,
 786                           [set_shrinker() available])
 787         ],[
 788                 AC_MSG_RESULT([no])
 789         ])
 790 ])
 791
 792 dnl #
 793 dnl # 2.6.35 API change,
 794 dnl # Add context to shrinker callback
 795 dnl #
 796 AC_DEFUN([SPL_AC_3ARGS_SHRINKER_CALLBACK],
 797         [AC_MSG_CHECKING([whether shrinker callback wants 3 args])
 798         tmp_flags="$EXTRA_KCFLAGS"
 799         EXTRA_KCFLAGS="-Werror"
 800         SPL_LINUX_TRY_COMPILE([
 801                 #include <linux/mm.h>
 802
 803                 int shrinker_cb(struct shrinker *, int, unsigned int);
 804         ],[
 805                 struct shrinker cache_shrinker = {
 806                         .shrink = shrinker_cb,
 807                         .seeks = DEFAULT_SEEKS,
 808                 };
 809                 register_shrinker(&cache_shrinker);
 810         ],[
 811                 AC_MSG_RESULT(yes)
 812                 AC_DEFINE(HAVE_3ARGS_SHRINKER_CALLBACK, 1,
 813                           [shrinker callback wants 3 args])
 814         ],[
 815                 AC_MSG_RESULT(no)
 816         ])
 817         EXTRA_KCFLAGS="$tmp_flags"
 818 ])
 819
 820 dnl #
 821 dnl # 2.6.25 API change,
 822 dnl # struct path entry added to struct nameidata
 823 dnl #
 824 AC_DEFUN([SPL_AC_PATH_IN_NAMEIDATA],
 825         [AC_MSG_CHECKING([whether struct path used in struct nameidata])
 826         SPL_LINUX_TRY_COMPILE([
 827                 #include <linux/namei.h>
 828         ],[
 829                 struct nameidata nd __attribute__ ((unused));
 830
 831                 nd.path.mnt = NULL;
 832                 nd.path.dentry = NULL;
 833         ],[
 834                 AC_MSG_RESULT(yes)
 835                 AC_DEFINE(HAVE_PATH_IN_NAMEIDATA, 1,
 836                           [struct path used in struct nameidata])
 837         ],[
 838                 AC_MSG_RESULT(no)
 839         ])
 840 ])
 841
 842 dnl #
 843 dnl # Custom SPL patch may export this system it is not required
 844 dnl #
 845 AC_DEFUN([SPL_AC_TASK_CURR], [
 846         SPL_CHECK_SYMBOL_EXPORT([task_curr], [kernel/sched.c],
 847                 [AC_DEFINE(HAVE_TASK_CURR, 1, [task_curr() exported])],
 848                 [])
 849 ])
 850
 851 dnl #
 852 dnl # 2.6.19 API change,
 853 dnl # Use CTL_UNNUMBERED when binary sysctl is not required
 854 dnl #
 855 AC_DEFUN([SPL_AC_CTL_UNNUMBERED],
 856         [AC_MSG_CHECKING([whether unnumbered sysctl support exists])
 857         SPL_LINUX_TRY_COMPILE([
 858                 #include <linux/sysctl.h>
 859         ],[
 860                 #ifndef CTL_UNNUMBERED
 861                 #error CTL_UNNUMBERED undefined
 862                 #endif
 863         ],[
 864                 AC_MSG_RESULT(yes)
 865                 AC_DEFINE(HAVE_CTL_UNNUMBERED, 1,
 866                           [unnumbered sysctl support exists])
 867         ],[
 868                 AC_MSG_RESULT(no)
 869         ])
 870 ])
 871
 872 dnl #
 873 dnl # 2.6.33 API change,
 874 dnl # Removed .ctl_name from struct ctl_table.
 875 dnl #
 876 AC_DEFUN([SPL_AC_CTL_NAME], [
 877         AC_MSG_CHECKING([whether struct ctl_table has ctl_name])
 878         SPL_LINUX_TRY_COMPILE([
 879                 #include <linux/sysctl.h>
 880         ],[
 881                 struct ctl_table ctl __attribute__ ((unused));
 882                 ctl.ctl_name = 0;
 883         ],[
 884                 AC_MSG_RESULT(yes)
 885                 AC_DEFINE(HAVE_CTL_NAME, 1, [struct ctl_table has ctl_name])
 886         ],[
 887                 AC_MSG_RESULT(no)
 888         ])
 889 ])
 890
 891 dnl #
 892 dnl # 2.6.16 API change.
 893 dnl # Check if 'fls64()' is available
 894 dnl #
 895 AC_DEFUN([SPL_AC_FLS64],
 896         [AC_MSG_CHECKING([whether fls64() is available])
 897         SPL_LINUX_TRY_COMPILE([
 898                 #include <linux/bitops.h>
 899         ],[
 900                 return fls64(0);
 901         ],[
 902                 AC_MSG_RESULT(yes)
 903                 AC_DEFINE(HAVE_FLS64, 1, [fls64() is available])
 904         ],[
 905                 AC_MSG_RESULT(no)
 906         ])
 907 ])
 908
 909 dnl #
 910 dnl # 2.6.18 API change, check whether device_create() is available.
 911 dnl # Device_create() was introduced in 2.6.18 and depricated
 912 dnl # class_device_create() which was fully removed in 2.6.26.
 913 dnl #
 914 AC_DEFUN([SPL_AC_DEVICE_CREATE], [
 915         SPL_CHECK_SYMBOL_EXPORT(
 916                 [device_create],
 917                 [drivers/base/core.c],
 918                 [AC_DEFINE(HAVE_DEVICE_CREATE, 1,
 919                 [device_create() is available])],
 920                 [])
 921 ])
 922
 923 dnl #
 924 dnl # 2.6.27 API change,
 925 dnl # device_create() uses 5 args, new 'drvdata' argument.
 926 dnl #
 927 AC_DEFUN([SPL_AC_5ARGS_DEVICE_CREATE], [
 928         AC_MSG_CHECKING([whether device_create() wants 5 args])
 929         tmp_flags="$EXTRA_KCFLAGS"
 930         EXTRA_KCFLAGS="-Werror"
 931         SPL_LINUX_TRY_COMPILE([
 932                 #include <linux/device.h>
 933         ],[
 934                 device_create(NULL, NULL, 0, NULL, "%d", 1);
 935         ],[
 936                 AC_MSG_RESULT(yes)
 937                 AC_DEFINE(HAVE_5ARGS_DEVICE_CREATE, 1,
 938                           [device_create wants 5 args])
 939         ],[
 940                 AC_MSG_RESULT(no)
 941         ])
 942         EXTRA_KCFLAGS="$tmp_flags"
 943 ])
 944
 945 dnl #
 946 dnl # 2.6.13 API change, check whether class_device_create() is available.
 947 dnl # Class_device_create() was introduced in 2.6.13 and depricated
 948 dnl # class_simple_device_add() which was fully removed in 2.6.13.
 949 dnl #
 950 AC_DEFUN([SPL_AC_CLASS_DEVICE_CREATE], [
 951         SPL_CHECK_SYMBOL_EXPORT(
 952                 [class_device_create],
 953                 [drivers/base/class.c],
 954                 [AC_DEFINE(HAVE_CLASS_DEVICE_CREATE, 1,
 955                 [class_device_create() is available])],
 956                 [])
 957 ])
 958
 959 dnl #
 960 dnl # 2.6.26 API change, set_normalized_timespec() is exported.
 961 dnl #
 962 AC_DEFUN([SPL_AC_SET_NORMALIZED_TIMESPEC_EXPORT], [
 963         SPL_CHECK_SYMBOL_EXPORT(
 964                 [set_normalized_timespec],
 965                 [kernel/time.c],
 966                 [AC_DEFINE(HAVE_SET_NORMALIZED_TIMESPEC_EXPORT, 1,
 967                 [set_normalized_timespec() is available as export])],
 968                 [])
 969 ])
 970
 971 dnl #
 972 dnl # 2.6.16 API change, set_normalize_timespec() moved to time.c
 973 dnl # previously it was available in time.h as an inline.
 974 dnl #
 975 AC_DEFUN([SPL_AC_SET_NORMALIZED_TIMESPEC_INLINE], [
 976         AC_MSG_CHECKING([whether set_normalized_timespec() is an inline])
 977         SPL_LINUX_TRY_COMPILE([
 978                 #include <linux/time.h>
 979                 void set_normalized_timespec(struct timespec *ts,
 980                                              time_t sec, long nsec) { }
 981         ],
 982         [],
 983         [
 984                 AC_MSG_RESULT(no)
 985         ],[
 986                 AC_MSG_RESULT(yes)
 987                 AC_DEFINE(HAVE_SET_NORMALIZED_TIMESPEC_INLINE, 1,
 988                           [set_normalized_timespec() is available as inline])
 989         ])
 990 ])
 991
 992 dnl #
 993 dnl # 2.6.18 API change,
 994 dnl # timespec_sub() inline function available in linux/time.h
 995 dnl #
 996 AC_DEFUN([SPL_AC_TIMESPEC_SUB], [
 997         AC_MSG_CHECKING([whether timespec_sub() is available])
 998         SPL_LINUX_TRY_COMPILE([
 999                 #include <linux/time.h>
1000         ],[
1001                 struct timespec a = { 0 };
1002                 struct timespec b = { 0 };
1003                 struct timespec c __attribute__ ((unused));
1004                 c = timespec_sub(a, b);
1005         ],[
1006                 AC_MSG_RESULT(yes)
1007                 AC_DEFINE(HAVE_TIMESPEC_SUB, 1, [timespec_sub() is available])
1008         ],[
1009                 AC_MSG_RESULT(no)
1010         ])
1011 ])
1012
1013 dnl #
1014 dnl # 2.6.19 API change,
1015 dnl # check if init_utsname() is available in linux/utsname.h
1016 dnl #
1017 AC_DEFUN([SPL_AC_INIT_UTSNAME], [
1018         AC_MSG_CHECKING([whether init_utsname() is available])
1019         SPL_LINUX_TRY_COMPILE([
1020                 #include <linux/utsname.h>
1021         ],[
1022                 struct new_utsname *a __attribute__ ((unused));
1023                 a = init_utsname();
1024         ],[
1025                 AC_MSG_RESULT(yes)
1026                 AC_DEFINE(HAVE_INIT_UTSNAME, 1, [init_utsname() is available])
1027         ],[
1028                 AC_MSG_RESULT(no)
1029         ])
1030 ])
1031
1032 dnl #
1033 dnl # 2.6.26 API change,
1034 dnl # definition of struct fdtable relocated to linux/fdtable.h
1035 dnl #
1036 AC_DEFUN([SPL_AC_FDTABLE_HEADER], [
1037         SPL_CHECK_HEADER([linux/fdtable.h], [FDTABLE], [], [])
1038 ])
1039
1040 dnl #
1041 dnl # 2.6.14 API change,
1042 dnl # check whether 'files_fdtable()' exists
1043 dnl #
1044 AC_DEFUN([SPL_AC_FILES_FDTABLE], [
1045         AC_MSG_CHECKING([whether files_fdtable() is available])
1046         SPL_LINUX_TRY_COMPILE([
1047                 #include <linux/sched.h>
1048                 #include <linux/file.h>
1049                 #ifdef HAVE_FDTABLE_HEADER
1050                 #include <linux/fdtable.h>
1051                 #endif
1052         ],[
1053                 struct files_struct *files = current->files;
1054                 struct fdtable *fdt __attribute__ ((unused));
1055                 fdt = files_fdtable(files);
1056         ],[
1057                 AC_MSG_RESULT(yes)
1058                 AC_DEFINE(HAVE_FILES_FDTABLE, 1, [files_fdtable() is available])
1059         ],[
1060                 AC_MSG_RESULT(no)
1061         ])
1062 ])
1063
1064 dnl #
1065 dnl # 2.6.18 API change,
1066 dnl # added linux/uaccess.h
1067 dnl #
1068 AC_DEFUN([SPL_AC_UACCESS_HEADER], [
1069         SPL_CHECK_HEADER([linux/uaccess.h], [UACCESS], [], [])
1070 ])
1071
1072 dnl #
1073 dnl # 2.6.12 API change,
1074 dnl # check whether 'kmalloc_node()' is available.
1075 dnl #
1076 AC_DEFUN([SPL_AC_KMALLOC_NODE], [
1077         AC_MSG_CHECKING([whether kmalloc_node() is available])
1078         SPL_LINUX_TRY_COMPILE([
1079                 #include <linux/slab.h>
1080         ],[
1081                 void *a __attribute__ ((unused));
1082                 a = kmalloc_node(1, GFP_KERNEL, 0);
1083         ],[
1084                 AC_MSG_RESULT(yes)
1085                 AC_DEFINE(HAVE_KMALLOC_NODE, 1, [kmalloc_node() is available])
1086         ],[
1087                 AC_MSG_RESULT(no)
1088         ])
1089 ])
1090
1091 dnl #
1092 dnl # 2.6.9 API change,
1093 dnl # check whether 'monotonic_clock()' is available it may
1094 dnl # be available for some archs but not others.
1095 dnl #
1096 AC_DEFUN([SPL_AC_MONOTONIC_CLOCK], [
1097         SPL_CHECK_SYMBOL_EXPORT(
1098                 [monotonic_clock],
1099                 [],
1100                 [AC_DEFINE(HAVE_MONOTONIC_CLOCK, 1,
1101                 [monotonic_clock() is available])],
1102                 [])
1103 ])
1104
1105 dnl #
1106 dnl # 2.6.16 API change,
1107 dnl # check whether 'struct inode' has i_mutex
1108 dnl #
1109 AC_DEFUN([SPL_AC_INODE_I_MUTEX], [
1110         AC_MSG_CHECKING([whether struct inode has i_mutex])
1111         SPL_LINUX_TRY_COMPILE([
1112                 #include <linux/fs.h>
1113                 #include <linux/mutex.h>
1114         ],[
1115                 struct inode i;
1116                 mutex_init(&i.i_mutex);
1117         ],[
1118                 AC_MSG_RESULT(yes)
1119                 AC_DEFINE(HAVE_INODE_I_MUTEX, 1, [struct inode has i_mutex])
1120         ],[
1121                 AC_MSG_RESULT(no)
1122         ])
1123 ])
1124
1125 dnl #
1126 dnl # 2.6.29 API change,
1127 dnl # Adaptive mutexs introduced.
1128 dnl #
1129 AC_DEFUN([SPL_AC_MUTEX_OWNER], [
1130         AC_MSG_CHECKING([whether struct mutex has owner])
1131         SPL_LINUX_TRY_COMPILE([
1132                 #include <linux/mutex.h>
1133         ],[
1134                 struct mutex mtx __attribute__ ((unused));
1135                 mtx.owner = NULL;
1136         ],[
1137                 AC_MSG_RESULT(yes)
1138                 AC_DEFINE(HAVE_MUTEX_OWNER, 1, [struct mutex has owner])
1139         ],[
1140                 AC_MSG_RESULT(no)
1141         ])
1142 ])
1143
1144 dnl #
1145 dnl # 2.6.18 API change,
1146 dnl # First introduced 'mutex_lock_nested()' in include/linux/mutex.h,
1147 dnl # as part of the mutex validator.  Fallback to using 'mutex_lock()'
1148 dnl # if the mutex validator is disabled or otherwise unavailable.
1149 dnl #
1150 AC_DEFUN([SPL_AC_MUTEX_LOCK_NESTED], [
1151         AC_MSG_CHECKING([whether mutex_lock_nested() is available])
1152         SPL_LINUX_TRY_COMPILE([
1153                 #include <linux/mutex.h>
1154         ],[
1155                 struct mutex mutex;
1156                 mutex_init(&mutex);
1157                 mutex_lock_nested(&mutex, 0);
1158         ],[
1159                 AC_MSG_RESULT(yes)
1160                 AC_DEFINE(HAVE_MUTEX_LOCK_NESTED, 1,
1161                 [mutex_lock_nested() is available])
1162         ],[
1163                 AC_MSG_RESULT(no)
1164         ])
1165 ])
1166
1167 dnl #
1168 dnl # 2.6.27 API change,
1169 dnl # on_each_cpu() uses 3 args, no 'retry' argument
1170 dnl #
1171 AC_DEFUN([SPL_AC_3ARGS_ON_EACH_CPU], [
1172         AC_MSG_CHECKING([whether on_each_cpu() wants 3 args])
1173         SPL_LINUX_TRY_COMPILE([
1174                 #include <linux/smp.h>
1175         ],[
1176                 on_each_cpu(NULL, NULL, 0);
1177         ],[
1178                 AC_MSG_RESULT(yes)
1179                 AC_DEFINE(HAVE_3ARGS_ON_EACH_CPU, 1,
1180                           [on_each_cpu wants 3 args])
1181         ],[
1182                 AC_MSG_RESULT(no)
1183         ])
1184 ])
1185
1186 dnl #
1187 dnl # 2.6.18 API change,
1188 dnl # kallsyms_lookup_name no longer exported
1189 dnl #
1190 AC_DEFUN([SPL_AC_KALLSYMS_LOOKUP_NAME], [
1191         SPL_CHECK_SYMBOL_EXPORT(
1192                 [kallsyms_lookup_name],
1193                 [],
1194                 [AC_DEFINE(HAVE_KALLSYMS_LOOKUP_NAME, 1,
1195                 [kallsyms_lookup_name() is available])],
1196                 [])
1197 ])
1198
1199 dnl #
1200 dnl # Proposed API change,
1201 dnl # This symbol is not available in stock kernels.  You may build a
1202 dnl # custom kernel with the *-spl-export-symbols.patch which will export
1203 dnl # these symbols for use.  If your already rolling a custom kernel for
1204 dnl # your environment this is recommended.
1205 dnl #
1206 AC_DEFUN([SPL_AC_GET_VMALLOC_INFO], [
1207         SPL_CHECK_SYMBOL_EXPORT(
1208                 [get_vmalloc_info],
1209                 [],
1210                 [AC_DEFINE(HAVE_GET_VMALLOC_INFO, 1,
1211                 [get_vmalloc_info() is available])],
1212                 [])
1213 ])
1214
1215 dnl #
1216 dnl # 2.6.17 API change
1217 dnl # The helper functions first_online_pgdat(), next_online_pgdat(), and
1218 dnl # next_zone() are introduced to simplify for_each_zone().  These symbols
1219 dnl # were exported in 2.6.17 for use by modules which was consistent with
1220 dnl # the previous implementation of for_each_zone().  From 2.6.18 - 2.6.19
1221 dnl # the symbols were exported as 'unused', and by 2.6.20 they exports
1222 dnl # were dropped entirely leaving modules no way to directly iterate over
1223 dnl # the zone list.  Because we need access to the zone helpers we check
1224 dnl # if the kernel contains the old or new implementation.  Then we check
1225 dnl # to see if the symbols we need for each version are available.  If they
1226 dnl # are not, dynamically aquire the addresses with kallsyms_lookup_name().
1227 dnl #
1228 AC_DEFUN([SPL_AC_PGDAT_HELPERS], [
1229         AC_MSG_CHECKING([whether symbol *_pgdat exist])
1230         grep -q -E 'first_online_pgdat' $LINUX/include/linux/mmzone.h 2>/dev/null
1231         rc=$?
1232         if test $rc -eq 0; then
1233                 AC_MSG_RESULT([yes])
1234                 AC_DEFINE(HAVE_PGDAT_HELPERS, 1, [pgdat helpers are available])
1235         else
1236                 AC_MSG_RESULT([no])
1237         fi
1238 ])
1239
1240 dnl #
1241 dnl # Proposed API change,
1242 dnl # This symbol is not available in stock kernels.  You may build a
1243 dnl # custom kernel with the *-spl-export-symbols.patch which will export
1244 dnl # these symbols for use.  If your already rolling a custom kernel for
1245 dnl # your environment this is recommended.
1246 dnl #
1247 AC_DEFUN([SPL_AC_FIRST_ONLINE_PGDAT], [
1248         SPL_CHECK_SYMBOL_EXPORT(
1249                 [first_online_pgdat],
1250                 [],
1251                 [AC_DEFINE(HAVE_FIRST_ONLINE_PGDAT, 1,
1252                 [first_online_pgdat() is available])],
1253                 [])
1254 ])
1255
1256 dnl #
1257 dnl # Proposed API change,
1258 dnl # This symbol is not available in stock kernels.  You may build a
1259 dnl # custom kernel with the *-spl-export-symbols.patch which will export
1260 dnl # these symbols for use.  If your already rolling a custom kernel for
1261 dnl # your environment this is recommended.
1262 dnl #
1263 AC_DEFUN([SPL_AC_NEXT_ONLINE_PGDAT], [
1264         SPL_CHECK_SYMBOL_EXPORT(
1265                 [next_online_pgdat],
1266                 [],
1267                 [AC_DEFINE(HAVE_NEXT_ONLINE_PGDAT, 1,
1268                 [next_online_pgdat() is available])],
1269                 [])
1270 ])
1271
1272 dnl #
1273 dnl # Proposed API change,
1274 dnl # This symbol is not available in stock kernels.  You may build a
1275 dnl # custom kernel with the *-spl-export-symbols.patch which will export
1276 dnl # these symbols for use.  If your already rolling a custom kernel for
1277 dnl # your environment this is recommended.
1278 dnl #
1279 AC_DEFUN([SPL_AC_NEXT_ZONE], [
1280         SPL_CHECK_SYMBOL_EXPORT(
1281                 [next_zone],
1282                 [],
1283                 [AC_DEFINE(HAVE_NEXT_ZONE, 1,
1284                 [next_zone() is available])],
1285                 [])
1286 ])
1287
1288 dnl #
1289 dnl # 2.6.17 API change,
1290 dnl # See SPL_AC_PGDAT_HELPERS for details.
1291 dnl #
1292 AC_DEFUN([SPL_AC_PGDAT_LIST], [
1293         SPL_CHECK_SYMBOL_EXPORT(
1294                 [pgdat_list],
1295                 [],
1296                 [AC_DEFINE(HAVE_PGDAT_LIST, 1,
1297                 [pgdat_list is available])],
1298                 [])
1299 ])
1300
1301 dnl #
1302 dnl # 2.6.18 API change,
1303 dnl # First introduced global_page_state() support as an inline.
1304 dnl #
1305 AC_DEFUN([SPL_AC_GLOBAL_PAGE_STATE], [
1306         AC_MSG_CHECKING([whether global_page_state() is available])
1307         SPL_LINUX_TRY_COMPILE([
1308                 #include <linux/mm.h>
1309         ],[
1310                 unsigned long state __attribute__ ((unused));
1311                 state = global_page_state(0);
1312         ],[
1313                 AC_MSG_RESULT(yes)
1314                 AC_DEFINE(HAVE_GLOBAL_PAGE_STATE, 1,
1315                           [global_page_state() is available])
1316         ],[
1317                 AC_MSG_RESULT(no)
1318         ])
1319 ])
1320
1321 dnl #
1322 dnl # 2.6.21 API change (plus subsequent naming convention changes),
1323 dnl # Public global zone stats now include a free page count.  However
1324 dnl # the enumerated names of the counters have changed since this API
1325 dnl # was introduced.  We need to deduce the corrent name to use.  This
1326 dnl # replaces the priviate get_zone_counts() interface.
1327 dnl #
1328 dnl # NR_FREE_PAGES was available from 2.6.21 to current kernels, which
1329 dnl # is 2.6.30 as of when this was written.
1330 dnl #
1331 AC_DEFUN([SPL_AC_ZONE_STAT_ITEM_FREE], [
1332         AC_MSG_CHECKING([whether page state NR_FREE_PAGES is available])
1333         SPL_LINUX_TRY_COMPILE([
1334                 #include <linux/mm.h>
1335         ],[
1336                 enum zone_stat_item zsi __attribute__ ((unused));
1337                 zsi = NR_FREE_PAGES;
1338         ],[
1339                 AC_MSG_RESULT(yes)
1340                 AC_DEFINE(HAVE_ZONE_STAT_ITEM_NR_FREE_PAGES, 1,
1341                           [Page state NR_FREE_PAGES is available])
1342         ],[
1343                 AC_MSG_RESULT(no)
1344         ])
1345 ])
1346
1347 dnl #
1348 dnl # 2.6.21 API change (plus subsequent naming convention changes),
1349 dnl # Public global zone stats now include an inactive page count.  However
1350 dnl # the enumerated names of the counters have changed since this API
1351 dnl # was introduced.  We need to deduce the corrent name to use.  This
1352 dnl # replaces the priviate get_zone_counts() interface.
1353 dnl #
1354 dnl # NR_INACTIVE was available from 2.6.21 to 2.6.27 and included both
1355 dnl # anonymous and file inactive pages.  As of 2.6.28 it was split in
1356 dnl # to NR_INACTIVE_ANON and NR_INACTIVE_FILE.
1357 dnl #
1358 AC_DEFUN([SPL_AC_ZONE_STAT_ITEM_INACTIVE], [
1359         AC_MSG_CHECKING([whether page state NR_INACTIVE is available])
1360         SPL_LINUX_TRY_COMPILE([
1361                 #include <linux/mm.h>
1362         ],[
1363                 enum zone_stat_item zsi __attribute__ ((unused));
1364                 zsi = NR_INACTIVE;
1365         ],[
1366                 AC_MSG_RESULT(yes)
1367                 AC_DEFINE(HAVE_ZONE_STAT_ITEM_NR_INACTIVE, 1,
1368                           [Page state NR_INACTIVE is available])
1369         ],[
1370                 AC_MSG_RESULT(no)
1371         ])
1372
1373         AC_MSG_CHECKING([whether page state NR_INACTIVE_ANON is available])
1374         SPL_LINUX_TRY_COMPILE([
1375                 #include <linux/mm.h>
1376         ],[
1377                 enum zone_stat_item zsi __attribute__ ((unused));
1378                 zsi = NR_INACTIVE_ANON;
1379         ],[
1380                 AC_MSG_RESULT(yes)
1381                 AC_DEFINE(HAVE_ZONE_STAT_ITEM_NR_INACTIVE_ANON, 1,
1382                           [Page state NR_INACTIVE_ANON is available])
1383         ],[
1384                 AC_MSG_RESULT(no)
1385         ])
1386
1387         AC_MSG_CHECKING([whether page state NR_INACTIVE_FILE is available])
1388         SPL_LINUX_TRY_COMPILE([
1389                 #include <linux/mm.h>
1390         ],[
1391                 enum zone_stat_item zsi __attribute__ ((unused));
1392                 zsi = NR_INACTIVE_FILE;
1393         ],[
1394                 AC_MSG_RESULT(yes)
1395                 AC_DEFINE(HAVE_ZONE_STAT_ITEM_NR_INACTIVE_FILE, 1,
1396                           [Page state NR_INACTIVE_FILE is available])
1397         ],[
1398                 AC_MSG_RESULT(no)
1399         ])
1400 ])
1401
1402 dnl #
1403 dnl # 2.6.21 API change (plus subsequent naming convention changes),
1404 dnl # Public global zone stats now include an active page count.  However
1405 dnl # the enumerated names of the counters have changed since this API
1406 dnl # was introduced.  We need to deduce the corrent name to use.  This
1407 dnl # replaces the priviate get_zone_counts() interface.
1408 dnl #
1409 dnl # NR_ACTIVE was available from 2.6.21 to 2.6.27 and included both
1410 dnl # anonymous and file active pages.  As of 2.6.28 it was split in
1411 dnl # to NR_ACTIVE_ANON and NR_ACTIVE_FILE.
1412 dnl #
1413 AC_DEFUN([SPL_AC_ZONE_STAT_ITEM_ACTIVE], [
1414         AC_MSG_CHECKING([whether page state NR_ACTIVE is available])
1415         SPL_LINUX_TRY_COMPILE([
1416                 #include <linux/mm.h>
1417         ],[
1418                 enum zone_stat_item zsi __attribute__ ((unused));
1419                 zsi = NR_ACTIVE;
1420         ],[
1421                 AC_MSG_RESULT(yes)
1422                 AC_DEFINE(HAVE_ZONE_STAT_ITEM_NR_ACTIVE, 1,
1423                           [Page state NR_ACTIVE is available])
1424         ],[
1425                 AC_MSG_RESULT(no)
1426         ])
1427
1428         AC_MSG_CHECKING([whether page state NR_ACTIVE_ANON is available])
1429         SPL_LINUX_TRY_COMPILE([
1430                 #include <linux/mm.h>
1431         ],[
1432                 enum zone_stat_item zsi __attribute__ ((unused));
1433                 zsi = NR_ACTIVE_ANON;
1434         ],[
1435                 AC_MSG_RESULT(yes)
1436                 AC_DEFINE(HAVE_ZONE_STAT_ITEM_NR_ACTIVE_ANON, 1,
1437                           [Page state NR_ACTIVE_ANON is available])
1438         ],[
1439                 AC_MSG_RESULT(no)
1440         ])
1441
1442         AC_MSG_CHECKING([whether page state NR_ACTIVE_FILE is available])
1443         SPL_LINUX_TRY_COMPILE([
1444                 #include <linux/mm.h>
1445         ],[
1446                 enum zone_stat_item zsi __attribute__ ((unused));
1447                 zsi = NR_ACTIVE_FILE;
1448         ],[
1449                 AC_MSG_RESULT(yes)
1450                 AC_DEFINE(HAVE_ZONE_STAT_ITEM_NR_ACTIVE_FILE, 1,
1451                           [Page state NR_ACTIVE_FILE is available])
1452         ],[
1453                 AC_MSG_RESULT(no)
1454         ])
1455 ])
1456
1457 dnl #
1458 dnl # Proposed API change for legacy kernels.
1459 dnl # This symbol is not available in older kernels.  For kernels post
1460 dnl # 2.6.21 the global_page_state() API is used to get free/inactive/active
1461 dnl # page state information.  This symbol is only used in legacy kernels
1462 dnl # any only as a last resort.
1463 dnl
1464 AC_DEFUN([SPL_AC_GET_ZONE_COUNTS], [
1465         AC_MSG_CHECKING([whether symbol get_zone_counts is needed])
1466         SPL_LINUX_TRY_COMPILE([
1467         ],[
1468                 #if !defined(HAVE_ZONE_STAT_ITEM_NR_FREE_PAGES)
1469                 #error "global_page_state needs NR_FREE_PAGES"
1470                 #endif
1471
1472                 #if !defined(HAVE_ZONE_STAT_ITEM_NR_ACTIVE) && \
1473                     !defined(HAVE_ZONE_STAT_ITEM_NR_ACTIVE_ANON) && \
1474                     !defined(HAVE_ZONE_STAT_ITEM_NR_ACTIVE_FILE)
1475                 #error "global_page_state needs NR_ACTIVE*"
1476                 #endif
1477
1478                 #if !defined(HAVE_ZONE_STAT_ITEM_NR_INACTIVE) && \
1479                     !defined(HAVE_ZONE_STAT_ITEM_NR_INACTIVE_ANON) && \
1480                     !defined(HAVE_ZONE_STAT_ITEM_NR_INACTIVE_FILE)
1481                 #error "global_page_state needs NR_INACTIVE*"
1482                 #endif
1483         ],[
1484                 AC_MSG_RESULT(no)
1485         ],[
1486                 AC_MSG_RESULT(yes)
1487                 AC_DEFINE(NEED_GET_ZONE_COUNTS, 1,
1488                           [get_zone_counts() is needed])
1489
1490                 SPL_CHECK_SYMBOL_EXPORT(
1491                         [get_zone_counts],
1492                         [],
1493                         [AC_DEFINE(HAVE_GET_ZONE_COUNTS, 1,
1494                         [get_zone_counts() is available])],
1495                         [])
1496         ])
1497 ])
1498
1499 dnl #
1500 dnl # 2.6.27 API change,
1501 dnl # The user_path_dir() replaces __user_walk()
1502 dnl #
1503 AC_DEFUN([SPL_AC_USER_PATH_DIR], [
1504         SPL_CHECK_SYMBOL_EXPORT(
1505                 [user_path_at],
1506                 [],
1507                 [AC_DEFINE(HAVE_USER_PATH_DIR, 1,
1508                 [user_path_dir() is available])],
1509                 [])
1510 ])
1511
1512 dnl #
1513 dnl # Symbol available in RHEL kernels not in stock kernels.
1514 dnl #
1515 AC_DEFUN([SPL_AC_SET_FS_PWD], [
1516         SPL_CHECK_SYMBOL_EXPORT(
1517                 [set_fs_pwd],
1518                 [],
1519                 [AC_DEFINE(HAVE_SET_FS_PWD, 1,
1520                 [set_fs_pwd() is available])],
1521                 [])
1522 ])
1523
1524 dnl #
1525 dnl # 2.6.25 API change,
1526 dnl # Simplied API by replacing mnt+dentry args with a single path arg.
1527 dnl #
1528 AC_DEFUN([SPL_AC_2ARGS_SET_FS_PWD],
1529         [AC_MSG_CHECKING([whether set_fs_pwd() wants 2 args])
1530         SPL_LINUX_TRY_COMPILE([
1531                 #include <linux/sched.h>
1532                 #include <linux/fs_struct.h>
1533         ],[
1534                 set_fs_pwd(NULL, NULL);
1535         ],[
1536                 AC_MSG_RESULT(yes)
1537                 AC_DEFINE(HAVE_2ARGS_SET_FS_PWD, 1,
1538                           [set_fs_pwd() wants 2 args])
1539         ],[
1540                 AC_MSG_RESULT(no)
1541         ])
1542 ])
1543
1544 dnl #
1545 dnl # SLES API change, never adopted in mainline,
1546 dnl # Third 'struct vfsmount *' argument removed.
1547 dnl #
1548 AC_DEFUN([SPL_AC_2ARGS_VFS_UNLINK],
1549         [AC_MSG_CHECKING([whether vfs_unlink() wants 2 args])
1550         SPL_LINUX_TRY_COMPILE([
1551                 #include <linux/fs.h>
1552         ],[
1553                 vfs_unlink(NULL, NULL);
1554         ],[
1555                 AC_MSG_RESULT(yes)
1556                 AC_DEFINE(HAVE_2ARGS_VFS_UNLINK, 1,
1557                           [vfs_unlink() wants 2 args])
1558         ],[
1559                 AC_MSG_RESULT(no)
1560         ])
1561 ])
1562
1563 dnl #
1564 dnl # SLES API change, never adopted in mainline,
1565 dnl # Third and sixth 'struct vfsmount *' argument removed.
1566 dnl #
1567 AC_DEFUN([SPL_AC_4ARGS_VFS_RENAME],
1568         [AC_MSG_CHECKING([whether vfs_rename() wants 4 args])
1569         SPL_LINUX_TRY_COMPILE([
1570                 #include <linux/fs.h>
1571         ],[
1572                 vfs_rename(NULL, NULL, NULL, NULL);
1573         ],[
1574                 AC_MSG_RESULT(yes)
1575                 AC_DEFINE(HAVE_4ARGS_VFS_RENAME, 1,
1576                           [vfs_rename() wants 4 args])
1577         ],[
1578                 AC_MSG_RESULT(no)
1579         ])
1580 ])
1581
1582 dnl #
1583 dnl # 2.6.36 API change,
1584 dnl # The 'struct fs_struct->lock' was changed from a rwlock_t to
1585 dnl # a spinlock_t to improve the fastpath performance.
1586 dnl #
1587 AC_DEFUN([SPL_AC_FS_STRUCT_SPINLOCK], [
1588         AC_MSG_CHECKING([whether struct fs_struct uses spinlock_t])
1589         SPL_LINUX_TRY_COMPILE([
1590                 #include <linux/sched.h>
1591                 #include <linux/fs_struct.h>
1592         ],[
1593                 struct fs_struct fs;
1594                 spin_lock_init(&fs.lock);
1595         ],[
1596                 AC_MSG_RESULT(yes)
1597                 AC_DEFINE(HAVE_FS_STRUCT_SPINLOCK, 1,
1598                           [struct fs_struct uses spinlock_t])
1599         ],[
1600                 AC_MSG_RESULT(no)
1601         ])
1602 ])
1603
1604 dnl #
1605 dnl # 2.6.29 API change,
1606 dnl # check whether 'struct cred' exists
1607 dnl #
1608 AC_DEFUN([SPL_AC_CRED_STRUCT], [
1609         AC_MSG_CHECKING([whether struct cred exists])
1610         SPL_LINUX_TRY_COMPILE([
1611                 #include <linux/cred.h>
1612         ],[
1613                 struct cred *cr __attribute__ ((unused));
1614                 cr  = NULL;
1615         ],[
1616                 AC_MSG_RESULT(yes)
1617                 AC_DEFINE(HAVE_CRED_STRUCT, 1, [struct cred exists])
1618         ],[
1619                 AC_MSG_RESULT(no)
1620         ])
1621 ])
1622
1623 dnl #
1624 dnl # Custom SPL patch may export this symbol.
1625 dnl #
1626 AC_DEFUN([SPL_AC_GROUPS_SEARCH], [
1627         SPL_CHECK_SYMBOL_EXPORT(
1628                 [groups_search],
1629                 [],
1630                 [AC_DEFINE(HAVE_GROUPS_SEARCH, 1,
1631                 [groups_search() is available])],
1632                 [])
1633 ])
1634
1635 dnl #
1636 dnl # 2.6.x API change,
1637 dnl # __put_task_struct() was exported in RHEL5 but unavailable elsewhere.
1638 dnl #
1639 AC_DEFUN([SPL_AC_PUT_TASK_STRUCT], [
1640         SPL_CHECK_SYMBOL_EXPORT(
1641                 [__put_task_struct],
1642                 [],
1643                 [AC_DEFINE(HAVE_PUT_TASK_STRUCT, 1,
1644                 [__put_task_struct() is available])],
1645                 [])
1646 ])
1647
1648 dnl #
1649 dnl # 2.6.32 API change,
1650 dnl # Unused 'struct file *' removed from prototype.
1651 dnl #
1652 AC_DEFUN([SPL_AC_5ARGS_PROC_HANDLER], [
1653         AC_MSG_CHECKING([whether proc_handler() wants 5 args])
1654         SPL_LINUX_TRY_COMPILE([
1655                 #include <linux/sysctl.h>
1656         ],[
1657                 proc_dostring(NULL, 0, NULL, NULL, NULL);
1658         ],[
1659                 AC_MSG_RESULT(yes)
1660                 AC_DEFINE(HAVE_5ARGS_PROC_HANDLER, 1,
1661                           [proc_handler() wants 5 args])
1662         ],[
1663                 AC_MSG_RESULT(no)
1664         ])
1665 ])
1666
1667 dnl #
1668 dnl # 2.6.x API change,
1669 dnl # kvasprintf() function added.
1670 dnl #
1671 AC_DEFUN([SPL_AC_KVASPRINTF], [
1672         SPL_CHECK_SYMBOL_EXPORT(
1673                 [kvasprintf],
1674                 [],
1675                 [AC_DEFINE(HAVE_KVASPRINTF, 1,
1676                 [kvasprintf() is available])],
1677                 [])
1678 ])
1679
1680 dnl #
1681 dnl # 2.6.35 API change,
1682 dnl # Unused 'struct dentry *' removed from prototype.
1683 dnl #
1684 AC_DEFUN([SPL_AC_3ARGS_FILE_FSYNC], [
1685         AC_MSG_CHECKING([whether file_fsync() wants 3 args])
1686         SPL_LINUX_TRY_COMPILE([
1687                 #include <linux/buffer_head.h>
1688         ],[
1689                 file_fsync(NULL, NULL, 0);
1690         ],[
1691                 AC_MSG_RESULT(yes)
1692                 AC_DEFINE(HAVE_3ARGS_FILE_FSYNC, 1,
1693                           [file_fsync() wants 3 args])
1694         ],[
1695                 AC_MSG_RESULT(no)
1696         ])
1697 ])
1698
1699 dnl #
1700 dnl # 2.6.33 API change. Also backported in RHEL5 as of 2.6.18-190.el5.
1701 dnl # Earlier versions of rwsem_is_locked() were inline and had a race
1702 dnl # condition.  The fixed version is exported as a symbol.  The race
1703 dnl # condition is fixed by acquiring sem->wait_lock, so we must not
1704 dnl # call that version while holding sem->wait_lock.
1705 dnl #
1706 AC_DEFUN([SPL_AC_EXPORTED_RWSEM_IS_LOCKED], [
1707         SPL_CHECK_SYMBOL_EXPORT(
1708                 [rwsem_is_locked],
1709                 [lib/rwsem-spinlock.c],
1710                 [AC_DEFINE(RWSEM_IS_LOCKED_TAKES_WAIT_LOCK, 1,
1711                 [rwsem_is_locked() acquires sem->wait_lock])],
1712                 [])
1713 ])
1714
1715 dnl #
1716 dnl # 2.6.37 API compat,
1717 dnl # The function invalidate_inodes() is no longer exported by the kernel.
1718 dnl # The prototype however is still available which means it is safe
1719 dnl # to acquire the symbol's address using spl_kallsyms_lookup_name().
1720 dnl #
1721 AC_DEFUN([SPL_AC_KERNEL_INVALIDATE_INODES], [
1722         SPL_CHECK_SYMBOL_EXPORT(
1723                 [invalidate_inodes],
1724                 [],
1725                 [AC_DEFINE(HAVE_INVALIDATE_INODES, 1,
1726                 [invalidate_inodes() is available])],
1727                 [])
1728 ])
1729
1730 dnl #
1731 dnl # 2.6.39 API compat,
1732 dnl # The function invalidate_inodes() now take 2 arguments.  The second
1733 dnl # 'kill_dirty' argument describes how invalidate_inodes() should
1734 dnl # handle dirty inodes.  Only when set will dirty inodes be discarded,
1735 dnl # otherwise they will be handled as busy.
1736 dnl #
1737 dnl # Unfortunately, we don't have access to the invalidate_inodes()
1738 dnl # prototype so it's not easy to check how many arguments it takes.
1739 dnl # However, this change was done for the benefit of invalidate_device()
1740 dnl # which also added an argument.  The invalidate_device() symbol does
1741 dnl # exist in the development headers so if it takes two arguments we
1742 dnl # can fairly safely infer that invalidate_inodes() takes two arguments
1743 dnl # as well.  See commit 93b270f76e7ef3b81001576860c2701931cdc78b.
1744 dnl #
1745 AC_DEFUN([SPL_AC_KERNEL_2ARGS_INVALIDATE_INODES],
1746         [AC_MSG_CHECKING([whether invalidate_inodes() wants 2 args])
1747         SPL_LINUX_TRY_COMPILE([
1748                 #include <linux/fs.h>
1749         ],[
1750                 return __invalidate_device(NULL, 0);
1751         ],[
1752                 AC_MSG_RESULT(yes)
1753                 AC_DEFINE(HAVE_2ARGS_INVALIDATE_INODES, 1,
1754                           [invalidate_inodes() wants 2 args])
1755         ],[
1756                 AC_MSG_RESULT(no)
1757         ])
1758 ])
1759
1760 dnl #
1761 dnl # 2.6.xx API compat,
1762 dnl # There currently exists no exposed API to partially shrink the dcache.
1763 dnl # The expected mechanism to shrink the cache is a registered shrinker
1764 dnl # which is called during memory pressure.
1765 dnl #
1766 AC_DEFUN([SPL_AC_SHRINK_DCACHE_MEMORY], [
1767         SPL_CHECK_SYMBOL_EXPORT(
1768                 [shrink_dcache_memory],
1769                 [fs/dcache.c],
1770                 [AC_DEFINE(HAVE_SHRINK_DCACHE_MEMORY, 1,
1771                 [shrink_dcache_memory() is available])],
1772                 [])
1773 ])
1774
1775 dnl #
1776 dnl # 2.6.xx API compat,
1777 dnl # There currently exists no exposed API to partially shrink the icache.
1778 dnl # The expected mechanism to shrink the cache is a registered shrinker
1779 dnl # which is called during memory pressure.
1780 dnl #
1781 AC_DEFUN([SPL_AC_SHRINK_ICACHE_MEMORY], [
1782         SPL_CHECK_SYMBOL_EXPORT(
1783                 [shrink_icache_memory],
1784                 [fs/inode.c],
1785                 [AC_DEFINE(HAVE_SHRINK_ICACHE_MEMORY, 1,
1786                 [shrink_icache_memory() is available])],
1787                 [])
1788 ])
1789
1790 dnl #
1791 dnl # 2.6.39 API compat,
1792 dnl # The path_lookup() function has been renamed to kern_path_parent()
1793 dnl # and the flags argument has been removed.  The only behavior now
1794 dnl # offered is that of LOOKUP_PARENT.  The spl already always passed
1795 dnl # this flag so dropping the flag does not impact us.
1796 dnl #
1797 AC_DEFUN([SPL_AC_KERN_PATH_PARENT], [
1798         SPL_CHECK_SYMBOL_EXPORT(
1799                 [kern_path_parent],
1800                 [fs/namei.c],
1801                 [AC_DEFINE(HAVE_KERN_PATH_PARENT, 1,
1802                 [kern_path_parent() is available])],
1803                 [])
1804 ])