AC_DEFUN([LINUX_AIO_NONVECTOR],
 [AC_CHECK_LINUX_BUILD([for non-vectorized aio kernel functions],
                       [ac_cv_linux_aio_nonvector],
                       [#include <linux/fs.h>],
                       [extern ssize_t
                        generic_file_aio_read(struct kiocb *, char __user *,
                                              size_t, loff_t);],
                       [LINUX_HAS_NONVECTOR_AIO],
                       [define if kernel functions like generic_file_aio_read use
                        non-vectorized i/o],
                       [])
 ])

AC_DEFUN([LINUX_EXPORTS_TASKLIST_LOCK], [
  AC_CHECK_LINUX_BUILD([for exported tasklist_lock],
		       [ac_cv_linux_exports_tasklist_lock],
[#include <linux/sched.h>],
[
extern rwlock_t tasklist_lock __attribute__((weak)); 
read_lock(&tasklist_lock);
],
		       [EXPORTED_TASKLIST_LOCK],
		       [define if tasklist_lock exported],
		       [])
])

AC_DEFUN([LINUX_COMPLETION_H_EXISTS], [
  AC_CHECK_LINUX_BUILD([for linux/completion.h],
		       [ac_cv_linux_completion_h_exists],
[#include <linux/version.h>
#include <linux/completion.h>],
[struct completion _c;
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,4,8)
lose
#endif],
		       [HAVE_LINUX_COMPLETION_H]
		       [Define if your kernel has a usable linux/completion.h],
		       [])
])


AC_DEFUN([LINUX_EXPORTS_INIT_MM], [
  AC_CHECK_LINUX_BUILD([for exported init_mm],
		       [ac_cv_linux_exports_init_mm],
		       [extern struct mm_struct init_mm;],
		       [void *address = &init_mm; printk("%p\n", address);],
		       [EXPORTED_INIT_MM],
		       [define if your kernel exports init_mm],
		       [])
  ])


AC_DEFUN([LINUX_EXPORTS_KALLSYMS_ADDRESS], [
  AC_CHECK_LINUX_BUILD([for exported kallsyms_address_to_symbol],
		       [ac_cv_linux_exports_kallsyms_address],
		       [#include <linux/modversions.h>],
[#ifndef __ver_kallsyms_address_to_symbol
#error kallsyms_address_to_symbol not exported
#endif],
		       [EXPORTED_KALLSYMS_ADDRESS],
		       [define if your linux kernel exports kallsyms address],
		       [])
])


AC_DEFUN([LINUX_EXPORTS_KALLSYMS_SYMBOL], [
  AC_CHECK_LINUX_BUILD([for exported kallsyms_symbol_to_address],
		       [ac_cv_linux_exports_kallsyms_symbol],
		       [#include <linux/modversions.h>],
[#ifndef __ver_kallsyms_symbol_to_address
#error kallsyms_symbol_to_address not exported
#endif],
		       [EXPORTED_KALLSYMS_SYMBOL],
		       [define if your linux kernel exports kallsyms],
		       [])
])


AC_DEFUN([LINUX_EXPORTS_SYS_CALL_TABLE], [
  AC_CHECK_LINUX_BUILD([for exported sys_call_table],
		       [ac_cv_linux_exports_sys_call_table],
		       [#include <linux/modversions.h>],
[#ifndef __ver_sys_call_table
#error sys_call_table not exported
#endif],
		       [EXPORTED_SYS_CALL_TABLE],
		       [define if your linux kernel exports sys_call_table],
		       [])
])


AC_DEFUN([LINUX_EXPORTS_IA32_SYS_CALL_TABLE], [
  AC_CHECK_LINUX_BUILD([for exported ia32_sys_call_table],
		       [ac_cv_linux_exports_ia32_sys_call_table],
		       [#include <linux/modversions.h>],
[#ifndef __ver_ia32_sys_call_table
#error ia32_sys_call_table not exported
#endif],
		       [EXPORTED_IA32_SYS_CALL_TABLE],
		       [define if your linux kernel exports ia32_sys_call_table],
		       [])
])


AC_DEFUN([LINUX_EXPORTS_SYS_CHDIR], [
  AC_CHECK_LINUX_BUILD([for exported sys_chdir],
		       [ac_cv_linux_exports_sys_chdir],
		       [extern asmlinkage long sys_chdir(void) __attribute__((weak));],
		       [void *address = &sys_chdir; printk("%p\n", address);],
		       [EXPORTED_SYS_CHDIR],
		       [define if your linux kernel exports sys_chdir],
		       [])
])


AC_DEFUN([LINUX_EXPORTS_SYS_OPEN], [
  AC_CHECK_LINUX_BUILD([for exported sys_open],
		       [ac_cv_linux_exports_sys_open],
		       [extern asmlinkage long sys_open(void) __attribute__((weak));],
		       [void *address = &sys_open; printk("%p\n", address);],
		       [EXPORTED_SYS_OPEN],
		       [define if your linux kernel exports sys_open],
		       [])
])


AC_DEFUN([LINUX_RECALC_SIGPENDING_ARG_TYPE], [
  AC_CHECK_LINUX_BUILD([for recalc_sigpending arg type],
		       [ac_cv_linux_func_recalc_sigpending_takes_void],
		       [#include <linux/sched.h>],
		       [recalc_sigpending();],
		       [RECALC_SIGPENDING_TAKES_VOID],
		       [define if your recalc_sigpending takes void],
		       [])
])


AC_DEFUN([LINUX_SCHED_STRUCT_TASK_STRUCT_HAS_SIGNAL_RLIM], [
  AC_CHECK_LINUX_BUILD([for signal->rlim in struct task_struct],
		       [ac_cv_linux_sched_struct_task_struct_has_signal_rlim],
		       [#include <linux/sched.h>],
		       [struct task_struct _tsk; printk("%d\n", _tsk.signal->rlim);],
		       [STRUCT_TASK_STRUCT_HAS_SIGNAL_RLIM],
		       [define if your struct task_struct has signal->rlim],
		       [])
])


AC_DEFUN([LINUX_KERNEL_POSIX_LOCK_FILE_WAIT_ARG], [
  AC_CHECK_LINUX_BUILD([for 3rd argument in posix_lock_file found in new kernels],
		       [ac_cv_linux_kernel_posix_lock_file_wait_arg],
		       [#include <linux/fs.h>],
		       [posix_lock_file(0,0,0);],
		       [POSIX_LOCK_FILE_WAIT_ARG],
		       [define if your kernel uses 3 arguments for posix_lock_file],
		       [])
])

AC_DEFUN([LINUX_KERNEL_SOCK_CREATE], [
  AC_CHECK_LINUX_BUILD([for 5th argument in sock_create found in some SELinux kernels],
		       [ac_cv_linux_kernel_sock_create_v],
		       [#include <linux/net.h>],
		       [sock_create(0,0,0,0,0);],
		       [LINUX_KERNEL_SOCK_CREATE_V],
		       [define if your linux kernel uses 5 arguments for sock_create],
		       [])
])


AC_DEFUN([LINUX_INODE_SETATTR_RETURN_TYPE], [
  AC_CHECK_LINUX_BUILD([for inode_setattr return type],
		       [ac_cv_linux_func_inode_setattr_returns_int],
		       [#include <linux/fs.h>],
		       [struct inode _inode;
			struct iattr _iattr;
			int i;
			i = inode_setattr(&_inode, &_iattr);],
		       [INODE_SETATTR_NOT_VOID],
		       [define if your setattr return return non-void],
		       [])
])



AC_DEFUN([LINUX_AOP_WRITEBACK_CONTROL], [
  AC_CHECK_LINUX_BUILD([whether aop.writepage takes a writeback_control],
		       [ac_cv_linux_func_a_writepage_takes_writeback_control],
[#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/writeback.h>],
[struct address_space_operations _aops;
struct page _page;
struct writeback_control _writeback_control;
(void)_aops.writepage(&_page, &_writeback_control);],
		       [AOP_WRITEPAGE_TAKES_WRITEBACK_CONTROL],
		       [define if aops.writepage takes a struct writeback_control],
		       [])
])


AC_DEFUN([LINUX_REFRIGERATOR], [
  AC_CHECK_LINUX_BUILD([whether refrigerator takes PF_FREEZE],
		       [ac_cv_linux_func_refrigerator_takes_pf_freeze],
[#include <linux/sched.h>
#ifdef HAVE_LINUX_FREEZER_H
#include <linux/freezer.h>
#endif],
		       [refrigerator(PF_FREEZE);],
		       [LINUX_REFRIGERATOR_TAKES_PF_FREEZE],
		       [define if your refrigerator takes PF_FREEZE],
		       [])
])


AC_DEFUN([LINUX_IOP_I_CREATE_TAKES_NAMEIDATA], [
  AC_CHECK_LINUX_BUILD([whether inode_operations.create takes a nameidata],
		       [ac_cv_linux_func_i_create_takes_nameidata],
[#include <linux/fs.h>
#include <linux/namei.h>],
[struct inode _inode;
struct dentry _dentry;
struct nameidata _nameidata;
(void)_inode.i_op->create(&_inode, &_dentry, 0, &_nameidata);],

		       [IOP_CREATE_TAKES_NAMEIDATA],
		       [define if your iops.create takes a nameidata argument],
		       [])
])


AC_DEFUN([LINUX_IOP_I_LOOKUP_TAKES_NAMEIDATA], [
  AC_CHECK_LINUX_BUILD([whether inode_operations.lookup takes a nameidata],
		       [ac_cv_linux_func_i_lookup_takes_nameidata],
[#include <linux/fs.h>
#include <linux/namei.h>],
[struct inode _inode;
struct dentry _dentry;
struct nameidata _nameidata;
(void)_inode.i_op->lookup(&_inode, &_dentry, &_nameidata);],
		       [IOP_LOOKUP_TAKES_NAMEIDATA],
		       [define if your iops.lookup takes a nameidata argument],
		       [])
])


AC_DEFUN([LINUX_IOP_I_PERMISSION_TAKES_NAMEIDATA], [
  AC_CHECK_LINUX_BUILD([whether inode_operations.permission takes a nameidata],
		       [ac_cv_linux_func_i_permission_takes_nameidata],
[#include <linux/fs.h>
#include <linux/namei.h>],
[struct inode _inode;
struct nameidata _nameidata;
(void)_inode.i_op->permission(&_inode, 0, &_nameidata);],
		       [IOP_PERMISSION_TAKES_NAMEIDATA],
		       [define if your iops.permission takes a nameidata argument],
		       [-Werror])
])


AC_DEFUN([LINUX_IOP_I_PERMISSION_TAKES_FLAGS], [
  AC_CHECK_LINUX_BUILD([whether inode_operations.permission takes flags],
			[ac_cv_linux_func_i_permission_takes_flags],
			[#include <linux/fs.h>],
			[struct inode _inode = {0};
			unsigned int flags = 0;
			(void)_inode.i_op->permission(&_inode, 0, flags);],
		       [IOP_PERMISSION_TAKES_FLAGS],
		       [define if your iops.permission takes a flags argument],
		       [-Werror])
])


AC_DEFUN([LINUX_IOP_I_PUT_LINK_TAKES_COOKIE], [
  AC_CHECK_LINUX_BUILD([whether inode_operations.put_link takes an opaque cookie],
		       [ac_cv_linux_func_i_put_link_takes_cookie],
[#include <linux/fs.h>
#include <linux/namei.h>],
[struct inode _inode;
struct dentry _dentry;
struct nameidata *_nameidata;
void *cookie;
(void)_inode.i_op->put_link(&_dentry, _nameidata, cookie);],
		       [IOP_PUT_LINK_TAKES_COOKIE],
		       [define if your iops.put_link takes a cookie],
		       [])
])


AC_DEFUN([LINUX_DOP_D_REVALIDATE_TAKES_NAMEIDATA], [
  AC_CHECK_LINUX_BUILD([whether dentry_operations.d_revalidate takes a nameidata],
		       [ac_cv_linux_func_d_revalidate_takes_nameidata],
                        [#include <linux/fs.h>
                        #include <linux/namei.h>
                        static int reval(struct dentry *d, struct nameidata *nd) { return 0; }
                        struct dentry_operations dops;],
                        [dops.d_revalidate = reval;],
		       [DOP_REVALIDATE_TAKES_NAMEIDATA],
		       [define if your dops.d_revalidate takes a nameidata argument],
		       [-Werror])
])


AC_DEFUN([LINUX_GET_SB_HAS_STRUCT_VFSMOUNT], [
  AC_CHECK_LINUX_BUILD([for struct vfsmount * in get_sb_nodev()],
		       [ac_cv_linux_get_sb_has_struct_vfsmount],
		       [#include <linux/fs.h>],
		       [get_sb_nodev(0,0,0,0,0);],
		       [GET_SB_HAS_STRUCT_VFSMOUNT],
		       [define if your get_sb_nodev needs a struct vfsmount argument],
		       [])
])


AC_DEFUN([LINUX_STATFS_TAKES_DENTRY], [
  AC_CHECK_LINUX_BUILD([for dentry in statfs],
		       [ac_cv_linux_statfs_takes_dentry],
[#include <linux/fs.h>
#include <linux/statfs.h>],
[extern int simple_statfs(struct dentry *, struct kstatfs *);],
		       [STATFS_TAKES_DENTRY],
		       [define if your statfs takes a dentry argument],
		       [])
])


AC_DEFUN([LINUX_LINUX_KEYRING_SUPPORT], [
  AC_CHECK_LINUX_BUILD([for linux kernel keyring support],
		       [ac_cv_linux_keyring_support],
[#include <linux/rwsem.h>
#ifdef HAVE_LINUX_KEY_TYPE_H
#include <linux/key-type.h>
#endif
#include <linux/key.h>
#include <linux/keyctl.h>],
[#ifdef CONFIG_KEYS
request_key(NULL, NULL, NULL);
#if !defined(KEY_POS_VIEW) || !defined(KEY_POS_SEARCH) || !defined(KEY_POS_SETATTR) 
#error "Your linux/key.h does not contain KEY_POS_VIEW or KEY_POS_SEARCH or KEY_POS_SETATTR"
#endif
#else
#error rebuild your kernel with CONFIG_KEYS
#endif],
		       [LINUX_KEYRING_SUPPORT],
		       [define if your kernel has keyring support],
		       [])
])


AC_DEFUN([LINUX_KEY_ALLOC_NEEDS_STRUCT_TASK], [
  AC_CHECK_LINUX_BUILD([if key_alloc() takes a struct task *],
			[ac_cv_key_alloc_needs_struct_task],
			[#include <linux/rwsem.h>
			#include <linux/key.h> ],
			[struct task_struct *t=NULL;
			struct key k = {};
			(void) key_alloc(NULL, NULL, k.uid, k.gid, t, 0, 0);],
			[KEY_ALLOC_NEEDS_STRUCT_TASK],
			[define if key_alloc takes a struct task *],
			[-Werror -Wno-pointer-arith])
])


AC_DEFUN([LINUX_KEY_ALLOC_NEEDS_CRED], [
  AC_CHECK_LINUX_BUILD([if key_alloc() takes credentials],
			[ac_cv_key_alloc_needs_cred],
			[#include <linux/rwsem.h>
			#include <linux/key.h>],
			[struct cred *c = NULL;
			struct key k = {};
			(void) key_alloc(NULL, NULL, k.uid, k.gid, c, 0, 0);],
			[KEY_ALLOC_NEEDS_CRED],
			[define if key_alloc takes credentials],
			[-Werror -Wno-pointer-arith])
])


AC_DEFUN([LINUX_INIT_WORK_HAS_DATA], [
  AC_CHECK_LINUX_BUILD([whether INIT_WORK has a _data argument],
		       [ac_cv_linux_init_work_has_data],
[#include <linux/kernel.h>
#include <linux/workqueue.h>],
[ 
void f(struct work_struct *w) {}
struct work_struct *w;
int *i;
INIT_WORK(w,f,i);],
		       [INIT_WORK_HAS_DATA],
		       [define if INIT_WORK takes a data (3rd) argument],
		       [])
])


AC_DEFUN([LINUX_REGISTER_SYSCTL_TABLE_NOFLAG], [
  AC_CHECK_LINUX_BUILD([whether register_sysctl_table has an insert_at_head argument],
		       [ac_cv_linux_register_sysctl_table_noflag],
		       [#include <linux/sysctl.h>],
		       [struct ctl_table *t; register_sysctl_table (t);],
		       [REGISTER_SYSCTL_TABLE_NOFLAG],
		       [define if register_sysctl_table has no insert_at head flag],
		       [])
])


AC_DEFUN([LINUX_FOP_F_FLUSH_TAKES_FL_OWNER_T], [
  AC_CHECK_LINUX_BUILD([whether file_operations.flush takes a fl_owner_t],
		       [ac_cv_linux_func_f_flush_takes_fl_owner_t],
		       [#include <linux/fs.h>],
[struct inode _inode;
struct file _file;
fl_owner_t id;
(void)_inode.i_fop->flush(&_file, &id);],
		       [FOP_FLUSH_TAKES_FL_OWNER_T],
		       [define if your fops.flush takes an fl_owner_t argument],
		       [])
])


AC_DEFUN([LINUX_FOP_F_FSYNC_TAKES_DENTRY], [
  AC_CHECK_LINUX_BUILD([whether file_operations.fsync takes a dentry argument],
		       [ac_cv_linux_func_f_fsync_takes_dentry],
		       [#include <linux/fs.h>],
[struct inode _inode;
struct file _file;
struct dentry _d;
(void)_inode.i_fop->fsync(&_file, &_d, 0);],
		       [FOP_FSYNC_TAKES_DENTRY],
		       [define if your fops.fsync takes an dentry argument],
		       [])
])


int (*fsync) (struct file *, loff_t start, loff_t end, int datasync);

AC_DEFUN([LINUX_FOP_F_FSYNC_TAKES_RANGE], [
  AC_CHECK_LINUX_BUILD([whether file_operations.fsync takes a range],
		       [ac_cv_linux_func_f_fsync_takes_range],
		       [#include <linux/fs.h>],
[struct inode _inode;
struct file _file;
loff_t start, end;
(void)_inode.i_fop->fsync(&_file, start, end, 0);],
		       [FOP_FSYNC_TAKES_RANGE],
		       [define if your fops.fsync takes range arguments],
		       [])
])


AC_DEFUN([LINUX_HAVE_KMEM_CACHE_T], [
  AC_CHECK_LINUX_BUILD([whether kmem_cache_t exists],
		       [ac_cv_linux_have_kmem_cache_t],
		       [#include <linux/slab.h>],
		       [kmem_cache_t *k;],
		       [HAVE_KMEM_CACHE_T],
		       [define if kmem_cache_t exists],
		       [])
])


AC_DEFUN([LINUX_KMEM_CACHE_CREATE_TAKES_DTOR], [
  AC_CHECK_LINUX_BUILD([whether kmem_cache_create takes a destructor argument],
		       [ac_cv_linux_kmem_cache_create_takes_dtor],
		       [#include <linux/slab.h>],
		       [kmem_cache_create(NULL, 0, 0, 0, NULL, NULL);],
		       [KMEM_CACHE_TAKES_DTOR],
		       [define if kmem_cache_create takes a destructor argument],
		       [])
])


AC_DEFUN([LINUX_KMEM_CACHE_CREATE_CTOR_TAKES_VOID],[
  AC_CHECK_LINUX_BUILD([whether kmem_cache_create constructor takes a void pointer],
			[ac_cv_linux_kmem_cache_create_ctor_takes_void],
			[#include <linux/slab.h>],
			[void _ctor(void *v) { }; kmem_cache_create(NULL, 0, 0, 0, _ctor);],
			[KMEM_CACHE_CTOR_TAKES_VOID],
			[define if kmem_cache_create constructor takes a single void ptr],
			[-Werror])
])


dnl This function checks not just the existence of the splice functions,
dnl but also that the signature matches (they gained an extra argument
dnl around 2.6.17)
AC_DEFUN([LINUX_FS_STRUCT_FOP_HAS_SPLICE], [
  AC_CHECK_LINUX_BUILD([for splice_write and splice_read in struct file_operations],
		       [ac_cv_linux_fs_struct_fop_has_splice],
		       [#include <linux/fs.h>],
		       [struct file_operations _fop;
			_fop.splice_write(NULL, NULL, NULL, 0, 0);
			_fop.splice_read(NULL, NULL, NULL, 0, 0);],
		       [STRUCT_FILE_OPERATIONS_HAS_SPLICE],
		       [define if struct file_operations has splice functions],
		       [])
])


AC_DEFUN([LINUX_KMEM_CACHE_INIT], [
  AC_CHECK_LINUX_BUILD([for new kmem_cache init function parameters],
		       [ac_cv_linux_kmem_cache_init],
		       [#include <linux/slab.h>],
		       [extern struct kmem_cache *
			kmem_cache_create(const char *, size_t, size_t,
					  unsigned long,
					  void (*)(struct kmem_cache *, void *));
			return;],
		       [KMEM_CACHE_INIT],
		       [define for new kmem_cache init function parameters],
		       [])
])


AC_DEFUN([LINUX_EXPORTS_PROC_ROOT_FS], [
  AC_CHECK_LINUX_BUILD([if proc_root_fs is defined and exported],
		       [ac_cv_linux_exports_proc_root_fs],
		       [#include <linux/proc_fs.h>],
		       [struct proc_dir_entry *p = proc_root_fs;],
		       [EXPORTED_PROC_ROOT_FS],
		       [define if proc_root_fs is exported],
		       [])
])


AC_DEFUN([LINUX_D_PATH_TAKES_STRUCT_PATH], [
  AC_CHECK_LINUX_BUILD([if d_path() takes a struct path argument],
		       [ac_cv_linux_d_path_takes_struct_path],
		       [#include <linux/fs.h>],
		       [struct path *p; d_path(p, NULL, 0);],
		       [D_PATH_TAKES_STRUCT_PATH],
		       [define if d_path() takes a struct path argument],
		       [])
])


AC_DEFUN([LINUX_NEW_EXPORT_OPS], [
  AC_CHECK_LINUX_BUILD([if kernel uses new export ops],
		       [ac_cv_linux_new_export_ops],
		       [#include <linux/exportfs.h>],
		       [struct export_operations _eops;
			_eops.fh_to_parent(NULL, NULL, 0, 0);],
		       [NEW_EXPORT_OPS],
		       [define if kernel uses new export ops],
		       [])
])


AC_DEFUN([LINUX_POSIX_TEST_LOCK_RETURNS_CONFLICT], [
  AC_CHECK_LINUX_BUILD([if posix_test_lock returns a struct file_lock],
		       [ac_cv_linux_posix_test_lock_returns_conflict],
		       [#include <linux/fs.h>],
		       [struct file_lock *lock;
			struct file * file;
			lock = posix_test_lock(file, lock);],
		       [POSIX_TEST_LOCK_RETURNS_CONFLICT],
		       [define if posix_test_lock returns the conflicting lock],
		       [])
])


AC_DEFUN([LINUX_POSIX_TEST_LOCK_CONFLICT_ARG], [
  AC_CHECK_LINUX_BUILD([if posix_test_lock takes a conflict argument],
		       [ac_cv_linux_posix_test_lock_conflict_arg],
		       [#include <linux/fs.h>],
		       [struct file_lock *lock;
			struct file *file;
			posix_test_lock(file, lock, lock);],
		       [POSIX_TEST_LOCK_CONFLICT_ARG],
		       [define if posix_test_lock takes a conflict argument],
		       [])
])


AC_DEFUN([LINUX_EXPORTS_KEY_TYPE_KEYRING], [
  AC_CHECK_LINUX_BUILD([for exported key_type_keyring],
		       [ac_cv_linux_exports_key_type_keyring],
[
#ifdef HAVE_LINUX_KEY_TYPE_H
#include <linux/key-type.h>
#endif
#include <linux/key.h>
],
		       [printk("%s", key_type_keyring.name);],
		       [EXPORTED_KEY_TYPE_KEYRING],
		       [define if key_type_keyring is exported],
		       [])
])


AC_DEFUN([LINUX_HAVE_TRY_TO_FREEZE], [
  AC_CHECK_LINUX_BUILD([for try_to_freeze],
		       [ac_cv_linux_have_try_to_freeze],
[#include <linux/sched.h>
#ifdef HAVE_LINUX_FREEZER_H
#include <linux/freezer.h>
#endif],
[#ifdef LINUX_REFRIGERATOR_TAKES_PF_FREEZE
   try_to_freeze(PF_FREEZE);
#else
   try_to_freeze();
#endif],
		       [HAVE_TRY_TO_FREEZE],
                       [define if your kernel has the try_to_freeze function],
                       [])
])


AC_DEFUN([LINUX_HAVE_DCACHE_LOCK], [
  AC_CHECK_LINUX_BUILD([for dcache_lock],
			[ac_cv_linux_have_dcache_lock],
			[#include <linux/fs.h> ],
			[printk("%p", &dcache_lock);],
			[HAVE_DCACHE_LOCK],
			[define if dcache_lock exists],
			[])
])


AC_DEFUN([LINUX_D_COUNT_IS_INT], [
  AC_CHECK_LINUX_BUILD([if dentry->d_count is an int],
			[ac_cv_linux_d_count_int],
			[#include <linux/fs.h> ],
			[struct dentry _d;
			dget(&_d);
			_d.d_count = 1;],
			[D_COUNT_INT],
			[define if dentry->d_count is an int],
			[-Werror])
])


AC_DEFUN([LINUX_DOP_D_DELETE_TAKES_CONST], [
  AC_CHECK_LINUX_BUILD([whether dentry.d_op->d_delete takes a const argument],
			[ac_cv_linux_dop_d_delete_takes_const],
			[#include <linux/fs.h>
			#include <linux/dcache.h>
			static int _d_del(const struct dentry *de) { return 0; }
			struct dentry_operations _d_ops;],
			[_d_ops.d_delete = _d_del;],
			[DOP_D_DELETE_TAKES_CONST],
			[define if dentry.d_op->d_delete takes a const argument],
			[-Werror])
])


AC_DEFUN([LINUX_IOP_MKDIR_TAKES_UMODE_T], [
  AC_CHECK_LINUX_BUILD([whether inode.i_op->mkdir takes a umode_t argument],
			[ac_cv_linux_iop_mkdir_takes_umode_t],
			[#include <linux/fs.h>
			static int _mkdir(struct inode *i, struct dentry *d, umode_t m) { return 0; }
			struct inode_operations _i_ops;],
			[_i_ops.mkdir = _mkdir;],
			[IOP_MKDIR_TAKES_UMODE_T],
			[define if inode.i_op->mkdir takes a umode_t argument],
			[-Werror])
])


AC_DEFUN([LINUX_IOP_CREATE_TAKES_UMODE_T], [
  AC_CHECK_LINUX_BUILD([whether inode.i_op->create takes a umode_t argument],
			[ac_cv_linux_iop_create_takes_umode_t],
			[#include <linux/fs.h>],
			[struct inode_operations _i_ops;
			int _create(struct inode *i, struct dentry *d, umode_t m, struct nameidata *n)
				{return 0;};
			_i_ops.create = _create;],
			[IOP_CREATE_TAKES_UMODE_T],
			[define if inode.i_op->create takes a umode_t argument],
			[-Werror])
])


AC_DEFUN([LINUX_EXPORT_OP_ENCODE_FH_TAKES_INODES], [
  AC_CHECK_LINUX_BUILD([whether export operation encode_fh takes inode arguments],
			[ac_cv_linux_export_op_encode_fh__takes_inodes],
			[#include <linux/exportfs.h>
			static int _encode_fh(struct inode *i, __u32 *fh, int *len, struct inode *p) { return 0; }
			struct export_operations _exp_ops;],
			[_exp_ops.encode_fh = _encode_fh;],
			[EXPORT_OP_ENCODE_FH_TAKES_INODES],
			[define if encode_fh export op takes inode arguments],
			[-Werror])
])


AC_DEFUN([LINUX_KMAP_ATOMIC_TAKES_NO_KM_TYPE], [
  AC_CHECK_LINUX_BUILD([whether kmap_atomic takes no km_type argument],
			[ac_cv_linux_kma_atomic_takes_no_km_type],
			[#include <linux/highmem.h>],
			[struct page *p = NULL;
			kmap_atomic(p);],
			[KMAP_ATOMIC_TAKES_NO_KM_TYPE],
			[define if kmap_atomic takes no km_type argument],
			[-Werror])
])


AC_DEFUN([LINUX_DENTRY_OPEN_TAKES_PATH], [
  AC_CHECK_LINUX_BUILD([whether dentry_open takes a path argument],
			[ac_cv_linux_dentry_open_takes_path],
			[#include <linux/fs.h>],
			[struct path p;
			dentry_open(&p, 0, NULL);],
			[DENTRY_OPEN_TAKES_PATH],
			[define if dentry_open takes a path argument],
			[-Werror])
])


AC_DEFUN([LINUX_D_ALIAS_IS_HLIST], [
  AC_CHECK_LINUX_BUILD([whether dentry->d_alias is an hlist],
			[ac_cv_linux_d_alias_is_hlist],
			[#include <linux/fs.h>],
			[struct dentry *d = NULL;
			struct hlist_node *hn = NULL;
			#if defined(STRUCT_DENTRY_HAS_D_U_D_ALIAS)
			d->d_u.d_alias = *hn;
			#else
			d->d_alias = *hn;
			#endif],
			[D_ALIAS_IS_HLIST],
			[define if dentry->d_alias is an hlist],
			[])
])


AC_DEFUN([LINUX_HLIST_ITERATOR_NO_NODE], [
  AC_CHECK_LINUX_BUILD([whether hlist iterators don't need a node parameter],
			[ac_cv_linux_hlist_takes_no_node],
			[#include <linux/list.h>
			#include <linux/fs.h>],
			[struct dentry *d = NULL, *cur;
			struct inode *ip;
			#if defined(STRUCT_DENTRY_HAS_D_U_D_ALIAS)
			# define d_alias d_u.d_alias
			#endif
			hlist_for_each_entry(cur, &ip->i_dentry, d_alias) { }
			],
			[HLIST_ITERATOR_NO_NODE],
			[define if hlist iterators don't need a node parameter],
			[])
])


AC_DEFUN([LINUX_IOP_I_CREATE_TAKES_BOOL], [
  AC_CHECK_LINUX_BUILD([whether inode_operations.create takes a bool],
			[ac_cv_linux_func_i_create_takes_bool],
			[#include <linux/fs.h>
			#include <linux/namei.h>],
			[struct inode _inode = {};
			struct dentry _dentry;
			bool b = true;
			(void)_inode.i_op->create(&_inode, &_dentry, 0, b);],
		       [IOP_CREATE_TAKES_BOOL],
		       [define if your iops.create takes a bool argument],
		       [-Werror])
])


AC_DEFUN([LINUX_DOP_D_REVALIDATE_TAKES_UNSIGNED], [
  AC_CHECK_LINUX_BUILD([whether dentry_operations.d_revalidate takes an unsigned int],
			[ac_cv_linux_func_d_revalidate_takes_unsigned],
			[#include <linux/fs.h>
			#include <linux/namei.h>
			static int reval(struct dentry *d, unsigned int i) { return 0; }
			struct dentry_operations _d_ops;],
			[_d_ops.d_revalidate = reval;],
		       [DOP_REVALIDATE_TAKES_UNSIGNED],
		       [define if your dops.d_revalidate takes an unsigned int argument],
		       [-Werror])
])


AC_DEFUN([LINUX_IOP_LOOKUP_TAKES_UNSIGNED], [
  AC_CHECK_LINUX_BUILD([whether inode operation lookup takes an unsigned int],
			[ac_cv_linux_func_lookup_takes_unsigned],
			[#include <linux/fs.h>
			#include <linux/namei.h>
			static struct dentry *look(struct inode *i, struct dentry *d, unsigned int j) { return NULL; }
			struct inode_operations _i_ops;],
			[_i_ops.lookup = look;],
		       [IOP_LOOKUP_TAKES_UNSIGNED],
		       [define if your iops.lookup takes an unsigned int argument],
		       [-Werror])
])


AC_DEFUN([LINUX_D_INVALIDATE_IS_VOID], [
  AC_CHECK_LINUX_BUILD([whether d_invalidate returns void],
			[ac_cv_linux_func_d_invalidate_returns_void],
			[#include <linux/fs.h>],
			[
			void d_invalidate(struct dentry *);
			],
		       [D_INVALIDATE_IS_VOID],
		       [define if your d_invalidate returns void],
		       [])
])