Revert "Remove misguided HAVE_MUTEX_OWNER check"

[mirror_spl.git] / config / spl-build.m4

diff --git a/config/spl-build.m4 b/config/spl-build.m4
index b2a50bf164b9908235587c6e00e786c5dc06583d..630d67c2d5daad0fa5c09e6ea82c82e026874f90 100644 (file)
--- a/config/spl-build.m4
+++ b/config/spl-build.m4
@@ -49,6 +49,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
        SPL_AC_USLEEP_RANGE
        SPL_AC_KMEM_CACHE_ALLOCFLAGS
        SPL_AC_WAIT_ON_BIT
+       SPL_AC_MUTEX_OWNER
        SPL_AC_INODE_LOCK
        SPL_AC_GROUP_INFO_GID
        SPL_AC_KMEM_CACHE_CREATE_USERCOPY
@@ -1561,6 +1562,35 @@ AC_DEFUN([SPL_AC_WAIT_ON_BIT], [
        ])
 ])
 
+dnl #
+dnl # Check whether mutex has owner with task_struct type.
+dnl #
+dnl # Note that before Linux 3.0, mutex owner is of type thread_info.
+dnl #
+dnl # Note that in Linux 3.18, the condition for owner is changed from
+dnl # defined(CONFIG_DEBUG_MUTEXES) || defined(CONFIG_SMP) to
+dnl # defined(CONFIG_DEBUG_MUTEXES) || defined(CONFIG_MUTEX_SPIN_ON_OWNER)
+dnl #
+AC_DEFUN([SPL_AC_MUTEX_OWNER], [
+       AC_MSG_CHECKING([whether mutex has owner])
+       tmp_flags="$EXTRA_KCFLAGS"
+       EXTRA_KCFLAGS="-Werror"
+       SPL_LINUX_TRY_COMPILE([
+               #include <linux/mutex.h>
+               #include <linux/spinlock.h>
+       ],[
+               DEFINE_MUTEX(m);
+               struct task_struct *t __attribute__ ((unused));
+               t = m.owner;
+       ],[
+               AC_MSG_RESULT(yes)
+               AC_DEFINE(HAVE_MUTEX_OWNER, 1, [yes])
+       ],[
+               AC_MSG_RESULT(no)
+       ])
+       EXTRA_KCFLAGS="$tmp_flags"
+])
+
 dnl #
 dnl # 4.7 API change
 dnl # i_mutex is changed to i_rwsem. Instead of directly using