Remove mutex_lock_nested() wrapper

The mutex_lock_nested() function has been available since Linux 2.6.18.
There is no longer a need to maintain this compatibility code.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

config/spl-build.m4

@@ -29,7 +29,6 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
 	SPL_AC_PDE_DATA
 	SPL_AC_MUTEX_OWNER
 	SPL_AC_MUTEX_OWNER_TASK_STRUCT
-	SPL_AC_MUTEX_LOCK_NESTED
 	SPL_AC_3ARGS_ON_EACH_CPU
 	SPL_AC_KALLSYMS_LOOKUP_NAME
 	SPL_AC_GET_VMALLOC_INFO
@@ -973,29 +972,6 @@ AC_DEFUN([SPL_AC_MUTEX_OWNER_TASK_STRUCT], [
 	EXTRA_KCFLAGS="$tmp_flags"
 ])
 
-dnl #
-dnl # 2.6.18 API change,
-dnl # First introduced 'mutex_lock_nested()' in include/linux/mutex.h,
-dnl # as part of the mutex validator.  Fallback to using 'mutex_lock()' 
-dnl # if the mutex validator is disabled or otherwise unavailable.
-dnl #
-AC_DEFUN([SPL_AC_MUTEX_LOCK_NESTED], [
-	AC_MSG_CHECKING([whether mutex_lock_nested() is available])
-	SPL_LINUX_TRY_COMPILE([
-		#include <linux/mutex.h>
-	],[
-		struct mutex mutex;
-		mutex_init(&mutex);
-		mutex_lock_nested(&mutex, 0);
-	],[
-		AC_MSG_RESULT(yes)
-		AC_DEFINE(HAVE_MUTEX_LOCK_NESTED, 1,
-		[mutex_lock_nested() is available])
-	],[
-		AC_MSG_RESULT(no)
-	])
-])
-
 dnl #
 dnl # 2.6.27 API change,
 dnl # on_each_cpu() uses 3 args, no 'retry' argument

include/linux/Makefile.am

@@ -10,7 +10,6 @@ KERNEL_H = \
 	$(top_srcdir)/include/linux/math64_compat.h \
 	$(top_srcdir)/include/linux/mm_compat.h \
 	$(top_srcdir)/include/linux/module_compat.h \
-	$(top_srcdir)/include/linux/mutex_compat.h \
 	$(top_srcdir)/include/linux/proc_compat.h \
 	$(top_srcdir)/include/linux/rwsem_compat.h \
 	$(top_srcdir)/include/linux/smp_compat.h \

include/linux/mutex_compat.h

@@ -1,36 +0,0 @@
-/*****************************************************************************\
- *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
- *  Copyright (C) 2007 The Regents of the University of California.
- *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
- *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
- *  UCRL-CODE-235197
- *
- *  This file is part of the SPL, Solaris Porting Layer.
- *  For details, see <http://zfsonlinux.org/>.
- *
- *  The SPL is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License as published by the
- *  Free Software Foundation; either version 2 of the License, or (at your
- *  option) any later version.
- *
- *  The SPL is distributed in the hope that it will be useful, but WITHOUT
- *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- *  for more details.
- *
- *  You should have received a copy of the GNU General Public License along
- *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
-\*****************************************************************************/
-
-#ifndef _SPL_MUTEX_COMPAT_H
-#define _SPL_MUTEX_COMPAT_H
-
-#include <linux/mutex.h>
-
-/* mutex_lock_nested() introduced in 2.6.18 */
-#ifndef HAVE_MUTEX_LOCK_NESTED
-# define mutex_lock_nested(lock, subclass)	mutex_lock(lock)
-#endif /* HAVE_MUTEX_LOCK_NESTED */
-
-#endif /* _SPL_MUTEX_COMPAT_H */
-

include/sys/types.h

@@ -33,7 +33,6 @@
 #include <linux/bitops_compat.h>
 #include <linux/smp_compat.h>
 #include <linux/kallsyms_compat.h>
-#include <linux/mutex_compat.h>
 #include <linux/module_compat.h>
 #include <linux/sysctl_compat.h>
 #include <linux/proc_compat.h>