d10c6e62892c5d338ddbf3b3fb55dd926201ccc8
[zfs.git] / config / kernel.m4
1 dnl #
2 dnl # Default ZFS kernel configuration 
3 dnl #
4 AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
5         ZFS_AC_KERNEL
6         ZFS_AC_SPL
7         ZFS_AC_TEST_MODULE
8         ZFS_AC_KERNEL_CONFIG
9         ZFS_AC_KERNEL_BDEV_BLOCK_DEVICE_OPERATIONS
10         ZFS_AC_KERNEL_TYPE_FMODE_T
11         ZFS_AC_KERNEL_KOBJ_NAME_LEN
12         ZFS_AC_KERNEL_3ARG_BLKDEV_GET
13         ZFS_AC_KERNEL_BLKDEV_GET_BY_PATH
14         ZFS_AC_KERNEL_OPEN_BDEV_EXCLUSIVE
15         ZFS_AC_KERNEL_INVALIDATE_BDEV_ARGS
16         ZFS_AC_KERNEL_BDEV_LOGICAL_BLOCK_SIZE
17         ZFS_AC_KERNEL_BIO_EMPTY_BARRIER
18         ZFS_AC_KERNEL_BIO_FAILFAST
19         ZFS_AC_KERNEL_BIO_FAILFAST_DTD
20         ZFS_AC_KERNEL_REQ_FAILFAST_MASK
21         ZFS_AC_KERNEL_BIO_END_IO_T_ARGS
22         ZFS_AC_KERNEL_BIO_RW_SYNC
23         ZFS_AC_KERNEL_BIO_RW_SYNCIO
24         ZFS_AC_KERNEL_REQ_SYNC
25         ZFS_AC_KERNEL_BLK_END_REQUEST
26         ZFS_AC_KERNEL_BLK_QUEUE_FLUSH
27         ZFS_AC_KERNEL_BLK_QUEUE_MAX_HW_SECTORS
28         ZFS_AC_KERNEL_BLK_QUEUE_MAX_SEGMENTS
29         ZFS_AC_KERNEL_BLK_QUEUE_PHYSICAL_BLOCK_SIZE
30         ZFS_AC_KERNEL_BLK_QUEUE_IO_OPT
31         ZFS_AC_KERNEL_BLK_QUEUE_NONROT
32         ZFS_AC_KERNEL_BLK_QUEUE_DISCARD
33         ZFS_AC_KERNEL_BLK_FETCH_REQUEST
34         ZFS_AC_KERNEL_BLK_REQUEUE_REQUEST
35         ZFS_AC_KERNEL_BLK_RQ_BYTES
36         ZFS_AC_KERNEL_BLK_RQ_POS
37         ZFS_AC_KERNEL_BLK_RQ_SECTORS
38         ZFS_AC_KERNEL_GET_DISK_RO
39         ZFS_AC_KERNEL_GET_GENDISK
40         ZFS_AC_KERNEL_RQ_IS_SYNC
41         ZFS_AC_KERNEL_RQ_FOR_EACH_SEGMENT
42         ZFS_AC_KERNEL_DISCARD_GRANULARITY
43         ZFS_AC_KERNEL_CONST_XATTR_HANDLER
44         ZFS_AC_KERNEL_XATTR_HANDLER_GET
45         ZFS_AC_KERNEL_XATTR_HANDLER_SET
46         ZFS_AC_KERNEL_SHOW_OPTIONS
47         ZFS_AC_KERNEL_FSYNC
48         ZFS_AC_KERNEL_EVICT_INODE
49         ZFS_AC_KERNEL_NR_CACHED_OBJECTS
50         ZFS_AC_KERNEL_FREE_CACHED_OBJECTS
51         ZFS_AC_KERNEL_FALLOCATE
52         ZFS_AC_KERNEL_TRUNCATE_RANGE
53         ZFS_AC_KERNEL_CREATE_UMODE_T
54         ZFS_AC_KERNEL_AUTOMOUNT
55         ZFS_AC_KERNEL_ENCODE_FH_WITH_INODE
56         ZFS_AC_KERNEL_CLEAR_INODE
57         ZFS_AC_KERNEL_INSERT_INODE_LOCKED
58         ZFS_AC_KERNEL_D_MAKE_ROOT
59         ZFS_AC_KERNEL_D_OBTAIN_ALIAS
60         ZFS_AC_KERNEL_CHECK_DISK_SIZE_CHANGE
61         ZFS_AC_KERNEL_TRUNCATE_SETSIZE
62         ZFS_AC_KERNEL_6ARGS_SECURITY_INODE_INIT_SECURITY
63         ZFS_AC_KERNEL_CALLBACK_SECURITY_INODE_INIT_SECURITY
64         ZFS_AC_KERNEL_MOUNT_NODEV
65         ZFS_AC_KERNEL_SHRINK
66         ZFS_AC_KERNEL_BDI
67         ZFS_AC_KERNEL_BDI_SETUP_AND_REGISTER
68         ZFS_AC_KERNEL_SET_NLINK
69
70         AS_IF([test "$LINUX_OBJ" != "$LINUX"], [
71                 KERNELMAKE_PARAMS="$KERNELMAKE_PARAMS O=$LINUX_OBJ"
72         ])
73         AC_SUBST(KERNELMAKE_PARAMS)
74
75
76         dnl # -Wall -fno-strict-aliasing -Wstrict-prototypes and other
77         dnl # compiler options are added by the kernel build system.
78         KERNELCPPFLAGS="$KERNELCPPFLAGS $NO_UNUSED_BUT_SET_VARIABLE"
79         KERNELCPPFLAGS="$KERNELCPPFLAGS -DHAVE_SPL -D_KERNEL"
80         KERNELCPPFLAGS="$KERNELCPPFLAGS -DTEXT_DOMAIN=\\\"zfs-linux-kernel\\\""
81
82         AC_SUBST(KERNELCPPFLAGS)
83 ])
84
85 dnl #
86 dnl # Detect name used for Module.symvers file in kernel
87 dnl #
88 AC_DEFUN([ZFS_AC_MODULE_SYMVERS], [
89         modpost=$LINUX/scripts/Makefile.modpost
90         AC_MSG_CHECKING([kernel file name for module symbols])
91         AS_IF([test "x$enable_linux_builtin" != xyes -a -f "$modpost"], [
92                 AS_IF([grep -q Modules.symvers $modpost], [
93                         LINUX_SYMBOLS=Modules.symvers
94                 ], [
95                         LINUX_SYMBOLS=Module.symvers
96                 ])
97
98                 AS_IF([test ! -f "$LINUX_OBJ/$LINUX_SYMBOLS"], [
99                         AC_MSG_ERROR([
100         *** Please make sure the kernel devel package for your distribution
101         *** is installed.  If your building with a custom kernel make sure the
102         *** kernel is configured, built, and the '--with-linux=PATH' configure
103         *** option refers to the location of the kernel source.])
104                 ])
105         ], [
106                 LINUX_SYMBOLS=NONE
107         ])
108         AC_MSG_RESULT($LINUX_SYMBOLS)
109         AC_SUBST(LINUX_SYMBOLS)
110 ])
111
112 dnl #
113 dnl # Detect the kernel to be built against
114 dnl #
115 AC_DEFUN([ZFS_AC_KERNEL], [
116         AC_ARG_WITH([linux],
117                 AS_HELP_STRING([--with-linux=PATH],
118                 [Path to kernel source]),
119                 [kernelsrc="$withval"])
120
121         AC_ARG_WITH(linux-obj,
122                 AS_HELP_STRING([--with-linux-obj=PATH],
123                 [Path to kernel build objects]),
124                 [kernelbuild="$withval"])
125
126         AC_MSG_CHECKING([kernel source directory])
127         AS_IF([test -z "$kernelsrc"], [
128                 AS_IF([test -e "/lib/modules/$(uname -r)/source"], [
129                         headersdir="/lib/modules/$(uname -r)/source"
130                         sourcelink=$(readlink -f "$headersdir")
131                 ], [test -e "/lib/modules/$(uname -r)/build"], [
132                         headersdir="/lib/modules/$(uname -r)/build"
133                         sourcelink=$(readlink -f "$headersdir")
134                 ], [
135                         sourcelink=$(ls -1d /usr/src/kernels/* \
136                                      /usr/src/linux-* \
137                                      2>/dev/null | grep -v obj | tail -1)
138                 ])
139
140                 AS_IF([test -n "$sourcelink" && test -e ${sourcelink}], [
141                         kernelsrc=`readlink -f ${sourcelink}`
142                 ], [
143                         AC_MSG_RESULT([Not found])
144                         AC_MSG_ERROR([
145         *** Please make sure the kernel devel package for your distribution
146         *** is installed then try again.  If that fails you can specify the
147         *** location of the kernel source with the '--with-linux=PATH' option.])
148                 ])
149         ], [
150                 AS_IF([test "$kernelsrc" = "NONE"], [
151                         kernsrcver=NONE
152                 ])
153         ])
154
155         AC_MSG_RESULT([$kernelsrc])
156         AC_MSG_CHECKING([kernel build directory])
157         AS_IF([test -z "$kernelbuild"], [
158                 AS_IF([test -e "/lib/modules/$(uname -r)/build"], [
159                         kernelbuild=`readlink -f /lib/modules/$(uname -r)/build`
160                 ], [test -d ${kernelsrc}-obj/${target_cpu}/${target_cpu}], [
161                         kernelbuild=${kernelsrc}-obj/${target_cpu}/${target_cpu}
162                 ], [test -d ${kernelsrc}-obj/${target_cpu}/default], [
163                         kernelbuild=${kernelsrc}-obj/${target_cpu}/default
164                 ], [test -d `dirname ${kernelsrc}`/build-${target_cpu}], [
165                         kernelbuild=`dirname ${kernelsrc}`/build-${target_cpu}
166                 ], [
167                         kernelbuild=${kernelsrc}
168                 ])
169         ])
170         AC_MSG_RESULT([$kernelbuild])
171
172         AC_MSG_CHECKING([kernel source version])
173         utsrelease1=$kernelbuild/include/linux/version.h
174         utsrelease2=$kernelbuild/include/linux/utsrelease.h
175         utsrelease3=$kernelbuild/include/generated/utsrelease.h
176         AS_IF([test -r $utsrelease1 && fgrep -q UTS_RELEASE $utsrelease1], [
177                 utsrelease=linux/version.h
178         ], [test -r $utsrelease2 && fgrep -q UTS_RELEASE $utsrelease2], [
179                 utsrelease=linux/utsrelease.h
180         ], [test -r $utsrelease3 && fgrep -q UTS_RELEASE $utsrelease3], [
181                 utsrelease=generated/utsrelease.h
182         ])
183
184         AS_IF([test "$utsrelease"], [
185                 kernsrcver=`(echo "#include <$utsrelease>";
186                              echo "kernsrcver=UTS_RELEASE") |
187                              cpp -I $kernelbuild/include |
188                              grep "^kernsrcver=" | cut -d \" -f 2`
189
190                 AS_IF([test -z "$kernsrcver"], [
191                         AC_MSG_RESULT([Not found])
192                         AC_MSG_ERROR([*** Cannot determine kernel version.])
193                 ])
194         ], [
195                 AC_MSG_RESULT([Not found])
196                 if test "x$enable_linux_builtin" != xyes; then
197                         AC_MSG_ERROR([*** Cannot find UTS_RELEASE definition.])
198                 else
199                         AC_MSG_ERROR([
200         *** Cannot find UTS_RELEASE definition.
201         *** Please run 'make prepare' inside the kernel source tree.])
202                 fi
203         ])
204
205         AC_MSG_RESULT([$kernsrcver])
206
207         LINUX=${kernelsrc}
208         LINUX_OBJ=${kernelbuild}
209         LINUX_VERSION=${kernsrcver}
210
211         AC_SUBST(LINUX)
212         AC_SUBST(LINUX_OBJ)
213         AC_SUBST(LINUX_VERSION)
214
215         ZFS_AC_MODULE_SYMVERS
216 ])
217
218 dnl #
219 dnl # Detect name used for the additional SPL Module.symvers file.  If one
220 dnl # does not exist this is likely because the SPL has been configured
221 dnl # but not built.  The '--with-spl-timeout' option can be passed
222 dnl # to pause here, waiting for the file to appear from a concurrently
223 dnl # building SPL package.  If the file does not appear in time, a good
224 dnl # guess is made as to what this file will be named based on what it
225 dnl # is named in the kernel build products.  This file will first be
226 dnl # used at link time so if the guess is wrong the build will fail
227 dnl # then.  This unfortunately means the ZFS package does not contain a
228 dnl # reliable mechanism to detect symbols exported by the SPL at
229 dnl # configure time.
230 dnl #
231 AC_DEFUN([ZFS_AC_SPL_MODULE_SYMVERS], [
232         AC_ARG_WITH([spl-timeout],
233                 AS_HELP_STRING([--with-spl-timeout=SECS],
234                 [Wait SECS for symvers file to appear  @<:@default=0@:>@]),
235                 [timeout="$withval"], [timeout=0])
236
237         AC_MSG_CHECKING([spl file name for module symbols])
238         SPL_SYMBOLS=NONE
239
240         while true; do
241                 AS_IF([test -r $SPL_OBJ/Module.symvers], [
242                         SPL_SYMBOLS=Module.symvers
243                 ], [test -r $SPL_OBJ/Modules.symvers], [
244                         SPL_SYMBOLS=Modules.symvers
245                 ], [test -r $SPL_OBJ/module/Module.symvers], [
246                         SPL_SYMBOLS=Module.symvers
247                 ], [test -r $SPL_OBJ/module/Modules.symvers], [
248                         SPL_SYMBOLS=Modules.symvers
249                 ])
250
251                 AS_IF([test $SPL_SYMBOLS != NONE -o $timeout -le 0], [
252                         break;
253                 ], [
254                         sleep 1
255                         timeout=$((timeout-1))
256                 ])
257         done
258
259         AS_IF([test "$SPL_SYMBOLS" = NONE], [
260                 SPL_SYMBOLS=$LINUX_SYMBOLS
261         ])
262
263         AC_MSG_RESULT([$SPL_SYMBOLS])
264         AC_SUBST(SPL_SYMBOLS)
265 ])
266
267 dnl #
268 dnl # Detect the SPL module to be built against
269 dnl #
270 AC_DEFUN([ZFS_AC_SPL], [
271         AC_ARG_WITH([spl],
272                 AS_HELP_STRING([--with-spl=PATH],
273                 [Path to spl source]),
274                 [splsrc="$withval"])
275
276         AC_ARG_WITH([spl-obj],
277                 AS_HELP_STRING([--with-spl-obj=PATH],
278                 [Path to spl build objects]),
279                 [splbuild="$withval"])
280
281
282         AC_MSG_CHECKING([spl source directory])
283         AS_IF([test -z "$splsrc"], [
284                 dnl #
285                 dnl # Look in the standard development package location
286                 dnl #
287                 sourcelink=`ls -1d /usr/src/spl-*/${LINUX_VERSION} \
288                             2>/dev/null | tail -1`
289
290                 dnl #
291                 dnl # Look in the DKMS source location
292                 dnl #
293                 AS_IF([test -z "$sourcelink" || test ! -e $sourcelink/spl_config.h], [
294                         sourcelink=`ls -1d /var/lib/dkms/spl/*/build \
295                                     2>/dev/null | tail -1`
296                 ])
297
298                 dnl #
299                 dnl # Look in the parent directory
300                 dnl #
301                 AS_IF([test -z "$sourcelink" || test ! -e $sourcelink/spl_config.h], [
302                         sourcelink=../spl
303                 ])
304
305                 dnl #
306                 dnl # Look in the kernel directory
307                 dnl #
308                 AS_IF([test -z "$sourcelink" || test ! -e $sourcelink/spl_config.h], [
309                         sourcelink="$LINUX"
310                 ])
311
312                 AS_IF([test -e $sourcelink/spl_config.h], [
313                         splsrc=`readlink -f ${sourcelink}`
314                 ], [
315                         AC_MSG_RESULT([Not found])
316                         AC_MSG_ERROR([
317         *** Please make sure the spl devel package for your distribution
318         *** is installed then try again.  If that fails you can specify the
319         *** location of the spl source with the '--with-spl=PATH' option.])
320                 ])
321         ], [
322                 AS_IF([test "$splsrc" = "NONE"], [
323                         splbuild=NONE
324                         splsrcver=NONE
325                 ])
326         ])
327
328         AC_MSG_RESULT([$splsrc])
329         AC_MSG_CHECKING([spl build directory])
330         AS_IF([test -z "$splbuild"], [
331                 splbuild=${splsrc}
332         ])
333         AC_MSG_RESULT([$splbuild])
334
335         AC_MSG_CHECKING([spl source version])
336         AS_IF([test -r $splbuild/spl_config.h &&
337                 fgrep -q SPL_META_VERSION $splbuild/spl_config.h], [
338
339                 splsrcver=`(echo "#include <spl_config.h>";
340                             echo "splsrcver=SPL_META_VERSION-SPL_META_RELEASE") |
341                             cpp -I $splbuild |
342                             grep "^splsrcver=" | tr -d \" | cut -d= -f2`
343         ])
344
345         AS_IF([test -z "$splsrcver"], [
346                 AC_MSG_RESULT([Not found])
347                 AC_MSG_ERROR([
348         *** Cannot determine the version of the spl source.
349         *** Please prepare the spl source before running this script])
350         ])
351
352         AC_MSG_RESULT([$splsrcver])
353
354         SPL=${splsrc}
355         SPL_OBJ=${splbuild}
356         SPL_VERSION=${splsrcver}
357
358         AC_SUBST(SPL)
359         AC_SUBST(SPL_OBJ)
360         AC_SUBST(SPL_VERSION)
361
362         ZFS_AC_SPL_MODULE_SYMVERS
363 ])
364
365 dnl #
366 dnl # Basic toolchain sanity check.
367 dnl #
368 AC_DEFUN([ZFS_AC_TEST_MODULE],
369         [AC_MSG_CHECKING([whether modules can be built])
370         ZFS_LINUX_TRY_COMPILE([],[],[
371                 AC_MSG_RESULT([yes])
372         ],[
373                 AC_MSG_RESULT([no])
374                 if test "x$enable_linux_builtin" != xyes; then
375                         AC_MSG_ERROR([*** Unable to build an empty module.])
376                 else
377                         AC_MSG_ERROR([
378         *** Unable to build an empty module.
379         *** Please run 'make scripts' inside the kernel source tree.])
380                 fi
381         ])
382 ])
383
384 dnl #
385 dnl # Certain kernel build options are not supported.  These must be
386 dnl # detected at configure time and cause a build failure.  Otherwise
387 dnl # modules may be successfully built that behave incorrectly.
388 dnl #
389 AC_DEFUN([ZFS_AC_KERNEL_CONFIG], [
390
391         AS_IF([test "$ZFS_META_LICENSE" = GPL], [
392                 AC_DEFINE([HAVE_GPL_ONLY_SYMBOLS], [1],
393                         [Define to 1 if licensed under the GPL])
394         ])
395
396         ZFS_AC_KERNEL_CONFIG_DEBUG_LOCK_ALLOC
397 ])
398
399 dnl #
400 dnl # Check CONFIG_DEBUG_LOCK_ALLOC
401 dnl #
402 dnl # This is typically only set for debug kernels because it comes with
403 dnl # a performance penalty.  However, when it is set it maps the non-GPL
404 dnl # symbol mutex_lock() to the GPL-only mutex_lock_nested() symbol.
405 dnl # This will cause a failure at link time which we'd rather know about
406 dnl # at compile time.
407 dnl #
408 dnl # Since we plan to pursue making mutex_lock_nested() a non-GPL symbol
409 dnl # with the upstream community we add a check to detect this case.
410 dnl #
411 AC_DEFUN([ZFS_AC_KERNEL_CONFIG_DEBUG_LOCK_ALLOC], [
412
413         ZFS_LINUX_CONFIG([DEBUG_LOCK_ALLOC], [
414                 AC_MSG_CHECKING([whether mutex_lock() is GPL-only])
415                 tmp_flags="$EXTRA_KCFLAGS"
416                 ZFS_LINUX_TRY_COMPILE([
417                         #include <linux/module.h>
418                         #include <linux/mutex.h>
419
420                         MODULE_LICENSE("$ZFS_META_LICENSE");
421                 ],[
422                         struct mutex lock;
423
424                         mutex_init(&lock);
425                         mutex_lock(&lock);
426                         mutex_unlock(&lock);
427                 ],[
428                         AC_MSG_RESULT(no)
429                 ],[
430                         AC_MSG_RESULT(yes)
431                         AC_MSG_ERROR([
432         *** Kernel built with CONFIG_DEBUG_LOCK_ALLOC which is incompatible
433         *** with the CDDL license and will prevent the module linking stage
434         *** from succeeding.  You must rebuild your kernel without this
435         *** option enabled.])
436                 ])
437                 EXTRA_KCFLAGS="$tmp_flags"
438         ], [])
439 ])
440
441 dnl #
442 dnl # ZFS_LINUX_CONFTEST
443 dnl #
444 AC_DEFUN([ZFS_LINUX_CONFTEST], [
445 cat confdefs.h - <<_ACEOF >conftest.c
446 $1
447 _ACEOF
448 ])
449
450 dnl #
451 dnl # ZFS_LANG_PROGRAM(C)([PROLOGUE], [BODY])
452 dnl #
453 m4_define([ZFS_LANG_PROGRAM], [
454 $1
455 int
456 main (void)
457 {
458 dnl Do *not* indent the following line: there may be CPP directives.
459 dnl Don't move the `;' right after for the same reason.
460 $2
461   ;
462   return 0;
463 }
464 ])
465
466 dnl #
467 dnl # ZFS_LINUX_COMPILE_IFELSE / like AC_COMPILE_IFELSE
468 dnl #
469 AC_DEFUN([ZFS_LINUX_COMPILE_IFELSE], [
470         m4_ifvaln([$1], [ZFS_LINUX_CONFTEST([$1])])
471         rm -Rf build && mkdir -p build && touch build/conftest.mod.c
472         echo "obj-m := conftest.o" >build/Makefile
473         modpost_flag=''
474         test "x$enable_linux_builtin" = xyes && modpost_flag='modpost=true' # fake modpost stage
475         AS_IF(
476                 [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 $modpost_flag) >/dev/null && AC_TRY_COMMAND([$3])],
477                 [$4],
478                 [_AC_MSG_LOG_CONFTEST m4_ifvaln([$5],[$5])]
479         )
480         rm -Rf build
481 ])
482
483 dnl #
484 dnl # ZFS_LINUX_TRY_COMPILE like AC_TRY_COMPILE
485 dnl #
486 AC_DEFUN([ZFS_LINUX_TRY_COMPILE],
487         [ZFS_LINUX_COMPILE_IFELSE(
488         [AC_LANG_SOURCE([ZFS_LANG_PROGRAM([[$1]], [[$2]])])],
489         [modules],
490         [test -s build/conftest.o],
491         [$3], [$4])
492 ])
493
494 dnl #
495 dnl # ZFS_LINUX_CONFIG
496 dnl #
497 AC_DEFUN([ZFS_LINUX_CONFIG],
498         [AC_MSG_CHECKING([whether Linux was built with CONFIG_$1])
499         ZFS_LINUX_TRY_COMPILE([
500                 #include <linux/module.h>
501         ],[
502                 #ifndef CONFIG_$1
503                 #error CONFIG_$1 not #defined
504                 #endif
505         ],[
506                 AC_MSG_RESULT([yes])
507                 $2
508         ],[
509                 AC_MSG_RESULT([no])
510                 $3
511         ])
512 ])
513
514 dnl #
515 dnl # ZFS_CHECK_SYMBOL_EXPORT
516 dnl # check symbol exported or not
517 dnl #
518 AC_DEFUN([ZFS_CHECK_SYMBOL_EXPORT], [
519         grep -q -E '[[[:space:]]]$1[[[:space:]]]' \
520                 $LINUX_OBJ/$LINUX_SYMBOLS 2>/dev/null
521         rc=$?
522         if test $rc -ne 0; then
523                 export=0
524                 for file in $2; do
525                         grep -q -E "EXPORT_SYMBOL.*($1)" \
526                                 "$LINUX/$file" 2>/dev/null
527                         rc=$?
528                         if test $rc -eq 0; then
529                                 export=1
530                                 break;
531                         fi
532                 done
533                 if test $export -eq 0; then :
534                         $4
535                 else :
536                         $3
537                 fi
538         else :
539                 $3
540         fi
541 ])
542
543 dnl #
544 dnl # ZFS_LINUX_TRY_COMPILE_SYMBOL
545 dnl # like ZFS_LINUX_TRY_COMPILE, except ZFS_CHECK_SYMBOL_EXPORT
546 dnl # is called if not compiling for builtin
547 dnl #
548 AC_DEFUN([ZFS_LINUX_TRY_COMPILE_SYMBOL], [
549         ZFS_LINUX_TRY_COMPILE([$1], [$2], [rc=0], [rc=1])
550         if test $rc -ne 0; then :
551                 $6
552         else
553                 if test "x$enable_linux_builtin" != xyes; then
554                         ZFS_CHECK_SYMBOL_EXPORT([$3], [$4], [rc=0], [rc=1])
555                 fi
556                 if test $rc -ne 0; then :
557                         $6
558                 else :
559                         $5
560                 fi
561         fi
562 ])