/*
 * Copyright (c) 2000-2016 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
 * Copyright (c) 1992, 1993, 1994, 1995
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
 * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
 * support for mandatory and extensible security protections.  This notice
 * is included in support of clause 2.2 (b) of the Apple Public License,
 * Version 2.0.
 */

/*
 * Warning: This file is generated automatically.
 * (Modifications made here may easily be lost!)
 *
 * Created by the script:
 *	@(#)vnode_if.sh	8.7 (Berkeley) 5/11/95
 */


#ifndef _SYS_VNODE_IF_H_
#define _SYS_VNODE_IF_H_

#include <sys/appleapiopts.h>
#include <sys/cdefs.h>
#include <sys/kernel_types.h>
#include <sys/buf.h>
#ifdef BSD_KERNEL_PRIVATE
#include <sys/vm.h>
#endif
#include <mach/memory_object_types.h>


#ifdef KERNEL

extern struct vnodeop_desc vnop_default_desc;
extern struct vnodeop_desc vnop_lookup_desc;
#ifdef KERNEL_PRIVATE
extern struct vnodeop_desc vnop_compound_open_desc;
extern struct vnodeop_desc vnop_compound_remove_desc;
extern struct vnodeop_desc vnop_compound_rename_desc;
extern struct vnodeop_desc vnop_compound_mkdir_desc;
extern struct vnodeop_desc vnop_compound_rmdir_desc;
#endif /* KERNEL_PRIVATE */
extern struct vnodeop_desc vnop_create_desc;
extern struct vnodeop_desc vnop_whiteout_desc; // obsolete
extern struct vnodeop_desc vnop_mknod_desc;
extern struct vnodeop_desc vnop_open_desc;
extern struct vnodeop_desc vnop_close_desc;
extern struct vnodeop_desc vnop_access_desc;
extern struct vnodeop_desc vnop_getattr_desc;
extern struct vnodeop_desc vnop_setattr_desc;
extern struct vnodeop_desc vnop_read_desc;
extern struct vnodeop_desc vnop_write_desc;
extern struct vnodeop_desc vnop_ioctl_desc;
extern struct vnodeop_desc vnop_select_desc;
extern struct vnodeop_desc vnop_exchange_desc;
extern struct vnodeop_desc vnop_revoke_desc;
extern struct vnodeop_desc vnop_mmap_desc;
extern struct vnodeop_desc vnop_mnomap_desc;
extern struct vnodeop_desc vnop_fsync_desc;
extern struct vnodeop_desc vnop_remove_desc;
extern struct vnodeop_desc vnop_link_desc;
extern struct vnodeop_desc vnop_rename_desc;
extern struct vnodeop_desc vnop_renamex_desc;
extern struct vnodeop_desc vnop_mkdir_desc;
extern struct vnodeop_desc vnop_rmdir_desc;
extern struct vnodeop_desc vnop_symlink_desc;
extern struct vnodeop_desc vnop_readdir_desc;
extern struct vnodeop_desc vnop_readdirattr_desc;
extern struct vnodeop_desc vnop_getattrlistbulk_desc;
extern struct vnodeop_desc vnop_readlink_desc;
extern struct vnodeop_desc vnop_inactive_desc;
extern struct vnodeop_desc vnop_reclaim_desc;
extern struct vnodeop_desc vnop_print_desc;
extern struct vnodeop_desc vnop_pathconf_desc;
extern struct vnodeop_desc vnop_advlock_desc;
extern struct vnodeop_desc vnop_truncate_desc;
extern struct vnodeop_desc vnop_allocate_desc;
extern struct vnodeop_desc vnop_pagein_desc;
extern struct vnodeop_desc vnop_pageout_desc;
extern struct vnodeop_desc vnop_searchfs_desc;
extern struct vnodeop_desc vnop_copyfile_desc;
extern struct vnodeop_desc vnop_clonefile_desc;
extern struct vnodeop_desc vnop_blktooff_desc;
extern struct vnodeop_desc vnop_offtoblk_desc;
extern struct vnodeop_desc vnop_blockmap_desc;
extern struct vnodeop_desc vnop_strategy_desc;
extern struct vnodeop_desc vnop_bwrite_desc;

#ifdef __APPLE_API_UNSTABLE

#if NAMEDSTREAMS
extern struct vnodeop_desc vnop_getnamedstream_desc;
extern struct vnodeop_desc vnop_makenamedstream_desc;
extern struct vnodeop_desc vnop_removenamedstream_desc;
#endif

#endif

#ifdef KERNEL_PRIVATE
/*
 * This pair of functions register and unregister callout with
 * buffer_cache_gc() code path. This callout enables underlying
 * fs to kick off any memory reclamation that would be otherwise
 * satisfied by buffer_cache_gc(). callout() will be called in the
 * vm_pageout code path, so precautions should be taken to not
 * allocate memory or take any locks which might have memory
 * allocation behind them. callout() can be called with first parameter
 * set to false, in which case memory reclamation should be
 * limited in scope. In case of the first parameter set to true, fs
 * MUST free some memory if possible. Second parameter to the
 * register function will be passed as a second parameter to the
 * callout() as is.
 * fs_buffer_cache_gc_unregister() second parameter will be used
 * to distinguish between same callout() and this parameter should
 * match the one passed during registration. It will unregister all
 * instances of the matching callout() and argument from the callout
 * list.
 */


extern int fs_buffer_cache_gc_register(void (* callout)(int, void *), void *);
extern int fs_buffer_cache_gc_unregister(void (* callout)(int, void *), void *);
#endif

__BEGIN_DECLS

struct vnop_lookup_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_dvp;
	vnode_t *a_vpp;
	struct componentname *a_cnp;
	vfs_context_t a_context;
};

/*!
 @function VNOP_LOOKUP
 @abstract Call down to a filesystem to look for a directory entry by name.
 @discussion VNOP_LOOKUP is the key pathway through which VFS asks a filesystem to find a file.  The vnode
 should be returned with an iocount to be dropped by the caller.  A VNOP_LOOKUP() calldown can come without
 a preceding VNOP_OPEN().
 @param dvp Directory in which to look up file.
 @param vpp Destination for found vnode.
 @param cnp Structure describing filename to find, reason for lookup, and various other data.
 @param ctx Context against which to authenticate lookup request.
 @return 0 for success or a filesystem-specific error.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_LOOKUP(vnode_t, vnode_t *, struct componentname *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_create_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_dvp;
	vnode_t *a_vpp;
	struct componentname *a_cnp;
	struct vnode_attr *a_vap;
	vfs_context_t a_context;
};

/*!
 @function VNOP_CREATE
 @abstract Call down to a filesystem to create a regular file (VREG).
 @discussion If file creation succeeds, "vpp" should be returned with an iocount to be dropped by the caller.
 A VNOP_CREATE() calldown can come without a preceding VNOP_OPEN().
 @param dvp Directory in which to create file.
 @param vpp Destination for vnode for newly created file.
 @param cnp Description of filename to create.
 @param vap File creation properties, as seen in vnode_getattr().  Manipulated with VATTR_ISACTIVE, VATTR_RETURN,
 VATTR_SET_SUPPORTED, and so forth.
 @param ctx Context against which to authenticate file creation.
 @return 0 for success or a filesystem-specific error.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_CREATE(vnode_t, vnode_t *, struct componentname *, struct vnode_attr *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_whiteout_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_dvp;
	struct componentname *a_cnp;
	int a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_WHITEOUT
 @abstract Obsolete - no longer supported.
 @discussion Whiteouts are used to support the union filesystem, whereby one filesystem is mounted "transparently"
 on top of another.  A whiteout in the upper layer of a union mount is a "deletion" of a file in the lower layer;
 lookups will catch the whiteout and fail, setting ISWHITEOUT in the componentname structure, even if an underlying 
 file of the same name exists.  The whiteout vnop is used for creation, deletion, and checking whether a directory
 supports whiteouts (see flags).
 also support the LOOKUP flag, which is used to test whether a directory supports whiteouts.
 @param dvp Directory in which to create.
 @param cnp Name information for whiteout.
 @param flags CREATE: create a whiteout. LOOKUP: check whether a directory supports whiteouts, DELETE: remove a whiteout.
 @param ctx Context against which to authenticate whiteout creation.
 @return 0 for success or a filesystem-specific error.  Returning 0 for LOOKUP indicates that a directory does support whiteouts.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_WHITEOUT(vnode_t, struct componentname *, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_mknod_args {
       struct vnodeop_desc *a_desc;
       vnode_t a_dvp;
       vnode_t *a_vpp;
       struct componentname *a_cnp;
       struct vnode_attr *a_vap;
       vfs_context_t a_context;
};

/*!
 @function VNOP_MKNOD
 @abstract Call down to a filesystem to create a special file.
 @discussion The mknod vnop is used to create character and block device files, named pipe (FIFO) files, and named sockets.
 The newly created file should be returned with an iocount which will be dropped by the caller.  A VNOP_MKNOD() call
 can come down without a preceding VNOP_OPEN().
 @param dvp Directory in which to create the special file.
 @param vpp Destination for newly created vnode.
 @param cnp Name information for new file.
 @param vap Attributes for new file, including type.
 @param ctx Context against which to authenticate node creation.
 @return 0 for success or a filesystem-specific error. 
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_MKNOD(vnode_t, vnode_t *, struct componentname *, struct vnode_attr *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_open_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	int a_mode;
	vfs_context_t a_context;
};

#ifdef KERNEL_PRIVATE
struct vnop_compound_open_args {
	struct vnodeop_desc *a_desc;

	vnode_t a_dvp;				/* Directory in which to open/create */
	vnode_t *a_vpp;				/* Resulting vnode */
	int a_fmode;	   			/* Open mode */
	struct componentname *a_cnp;		/* Path to look up */
	struct vnode_attr *a_vap;		/* Attributes with which to create, if appropriate */
	uint32_t a_flags;			/* VNOP-control flags */
	uint32_t *a_status;			/* Information about results */

	vfs_context_t a_context;			/* Authorization context */

	int (*a_open_create_authorizer)(	/* Authorizer for create case */
			vnode_t dvp,			/* Directory in which to create */
			struct componentname *cnp,	/* As passed to VNOP */
			struct vnode_attr *vap,		/* As passed to VNOP */
			vfs_context_t ctx,		/* Context */
			void *reserved);		/* Who knows */

	int (*a_open_existing_authorizer)(	/* Authorizer for preexisting case */
			vnode_t vp,			/* vp to open */
			struct componentname *cnp,	/* Lookup state */
			int fmode,			/* As passed to VNOP */
			vfs_context_t ctx,		/* Context */   
			void *reserved);		/* Who knows */

	void *a_reserved;
};

/* Results */
#define COMPOUND_OPEN_STATUS_DID_CREATE 0x00000001
#endif /* KERNEL_PRIVATE */

/*!
 @function VNOP_OPEN
 @abstract Call down to a filesystem to open a file.
 @discussion The open vnop gives a filesystem a chance to initialize a file for 
 operations like reading, writing, and ioctls.  VFS promises to send down exactly one VNOP_CLOSE()
 for each VNOP_OPEN().
 @param vp File to open.
 @param mode FREAD and/or FWRITE.
 @param ctx Context against which to authenticate open.
 @return 0 for success or a filesystem-specific error. 
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_OPEN(vnode_t, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

#ifdef BSD_KERNEL_PRIVATE
struct nameidata;
extern int VNOP_COMPOUND_OPEN(vnode_t dvp, vnode_t *vpp, struct nameidata *ndp, int32_t flags, int32_t fmode, uint32_t *status, struct vnode_attr *vap, vfs_context_t ctx);
#endif

struct vnop_close_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	int a_fflag;
	vfs_context_t a_context;
};

/*!
 @function VNOP_CLOSE
 @abstract Call down to a filesystem to close a file.
 @discussion The close vnop gives a filesystem a chance to release state set up 
 by a VNOP_OPEN(). VFS promises to send down exactly one VNOP_CLOSE() for each VNOP_OPEN().
 @param vp File to close.
 @param fflag FREAD and/or FWRITE; in the case of a file opened with open(2), fflag corresponds
 to how the file was opened.
 @param ctx Context against which to authenticate close.
 @return 0 for success or a filesystem-specific error. 
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_CLOSE(vnode_t, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_access_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	int a_action;
	vfs_context_t a_context;
};

/*!
 @function VNOP_ACCESS
 @abstract Call down to a filesystem to see if a kauth-style operation is permitted.
 @discussion VNOP_ACCESS is currently only called on filesystems which mark themselves
 as doing their authentication remotely (vfs_setauthopaque(), vfs_authopaque()).  A VNOP_ACCESS()
 calldown may come without any preceding VNOP_OPEN().
 @param vp File to authorize action for.
 @param action kauth-style action to be checked for permissions, e.g. KAUTH_VNODE_DELETE.
 @param ctx Context against which to authenticate action.
 @return 0 for success or a filesystem-specific error. 
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_ACCESS(vnode_t, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_getattr_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	struct vnode_attr *a_vap;
	vfs_context_t a_context;
};

/*!
 @function VNOP_GETATTR
 @abstract Call down to a filesystem to get vnode attributes.
 @discussion Supported attributes ("Yes, I am returning this information") are set with VATTR_SET_SUPPORTED.  
 Which attributes have been requested is checked with VATTR_IS_ACTIVE.  Attributes
 are returned with VATTR_RETURN.  It is through VNOP_GETATTR that routines like stat() get their information.  
 A VNOP_GETATTR() calldown may come without any preceding VNOP_OPEN().
 @param vp The vnode whose attributes to get.
 @param vap Container for which attributes are requested, which attributes are supported by the filesystem, and attribute values.
 @param ctx Context against which to authenticate request for attributes.
 @return 0 for success or a filesystem-specific error. VNOP_GETATTR() can return success even if not 
 all requested attributes were returned; returning an error-value should indicate that something went wrong, rather than that
 some attribute is not supported.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_GETATTR(vnode_t, struct vnode_attr *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_setattr_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	struct vnode_attr *a_vap;
	vfs_context_t a_context;
};

/*!
 @function VNOP_SETATTR
 @abstract Call down to a filesystem to set vnode attributes.
 @discussion Supported attributes ("Yes, I am setting this attribute.") are set with VATTR_SET_SUPPORTED.  
 Requested attributes are checked with VATTR_IS_ACTIVE.  Attribute values are accessed directly through 
 structure fields.  VNOP_SETATTR() is the core of the KPI function vnode_setattr(), which is used by chmod(),
 chown(), truncate(), and many others.  A VNOP_SETATTR() call may come without any preceding VNOP_OPEN().
 @param vp The vnode whose attributes to set.
 @param vap Container for which attributes are to be set and their desired values, as well as for the filesystem to 
 return information about which attributes were successfully set.
 @param ctx Context against which to authenticate request for attribute change.
 @return 0 for success or a filesystem-specific error.  VNOP_SETATTR() can return success even if not 
 all requested attributes were set; returning an error-value should indicate that something went wrong, rather than that
 some attribute is not supported.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_SETATTR(vnode_t, struct vnode_attr *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_read_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	struct uio *a_uio;
	int a_ioflag;
	vfs_context_t a_context;
};

/*!
 @function VNOP_READ
 @abstract Call down to a filesystem to read file data.
 @discussion VNOP_READ() is where the hard work of of the read() system call happens.  The filesystem may use
 the buffer cache, the cluster layer, or an alternative method to get its data; uio routines will be used to see that data
 is copied to the correct virtual address in the correct address space and will update its uio argument
 to indicate how much data has been moved.  
 @param vp The vnode to read from.
 @param uio Description of request, including file offset, amount of data requested, destination address for data,
 and whether that destination is in kernel or user space.
 @param ctx Context against which to authenticate read request.
 @return 0 for success or a filesystem-specific error.  VNOP_READ() can return success even if less data was 
 read than originally requested; returning an error value should indicate that something actually went wrong.
 */
extern errno_t VNOP_READ(vnode_t vp, struct uio *uio, int, vfs_context_t ctx);

struct vnop_write_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	struct uio *a_uio;
	int a_ioflag;
	vfs_context_t a_context;
};

/*!
 @function VNOP_WRITE
 @abstract Call down to the filesystem to write file data.
 @discussion VNOP_WRITE() is to write() as VNOP_READ() is to read().  The filesystem may use
 the buffer cache, the cluster layer, or an alternative method to write its data; uio routines will be used to see that data
 is copied to the correct virtual address in the correct address space and will update its uio argument
 to indicate how much data has been moved.  
 @param vp The vnode to write to.
 @param uio Description of request, including file offset, amount of data to write, source address for data,
 and whether that destination is in kernel or user space.
 @param ctx Context against which to authenticate write request.
 @return 0 for success or a filesystem-specific error.  VNOP_WRITE() can return success even if less data was 
 written than originally requested; returning an error value should indicate that something actually went wrong.
 */
extern errno_t VNOP_WRITE(vnode_t vp, struct uio *uio, int ioflag, vfs_context_t ctx);

struct vnop_ioctl_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	u_long a_command;
	caddr_t a_data;
	int a_fflag;
	vfs_context_t a_context;
};

/*!
 @function VNOP_IOCTL
 @abstract Call down to a filesystem or device driver to execute various control operations on or request data about a file.
 @discussion Ioctl controls are typically associated with devices, but they can in fact be passed
 down for any file; they are used to implement any of a wide range of controls and information requests. 
 fcntl() calls VNOP_IOCTL for several commands, and will attempt a VNOP_IOCTL if it is passed an unknown command, 
 though no copyin or copyout of  arguments can occur in this case--the "arg" must be an integer value.  
 Filesystems can define their own fcntls using this mechanism.  How ioctl commands are structured 
 is slightly complicated; see the manual page for ioctl(2).
 @param vp The vnode to execute the command on.
 @param command Identifier for action to take.
 @param data Pointer to data; this can be an integer constant (of 32 bits only) or an address to be read from or written to, 
 depending on "command."  If it is an address, it is valid and resides in the kernel; callers of VNOP_IOCTL() are 
 responsible for copying to and from userland.
 @param ctx Context against which to authenticate ioctl request.
 @return 0 for success or a filesystem-specific error.  
 */
extern errno_t VNOP_IOCTL(vnode_t vp, u_long command, caddr_t data, int fflag, vfs_context_t ctx);

struct vnop_select_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	int a_which;
	int a_fflags;
	void *a_wql;
	vfs_context_t a_context;
};

/*!
 @function VNOP_SELECT
 @abstract Call down to a filesystem or device to check if a file is ready for I/O and request later notification if it is not currently ready.
 @discussion In general, regular are always "ready for I/O" and their select vnops simply return "1."  
 Devices, though, may or may not be read; they keep track of who is selecting on them and send notifications
 when they become ready.  xnu provides structures and routines for tracking threads waiting for I/O and waking up  
 those threads: see selrecord(), selthreadclear(), seltrue(), selwait(), selwakeup(), and the selinfo structure (sys/select.h).
 @param vp The vnode to check for I/O readiness.
 @param which What kind of I/O is desired: FREAD, FWRITE.
 @param fflags Flags from fileglob as seen in fcntl.h, e.g. O_NONBLOCK, O_APPEND.
 @param wql Opaque object to pass to selrecord().
 @param ctx Context to authenticate for select request.
 @return Nonzero indicates that a file is ready for I/O.  0 indicates that the file is not ready for I/O;
 there is no way to return an error.  0 should be returned if the device (or file) is not ready for I/O
 and the driver (or filesystem) is going to track the request and provide subsequent wakeups.
 the device (or filesystem) will provide a wakeup.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_SELECT(vnode_t, int, int, void *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_exchange_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_fvp;
        vnode_t a_tvp;
	int a_options;
	vfs_context_t a_context;
};

/*!
 @function VNOP_EXCHANGE
 @abstract Call down to a filesystem to atomically exchange the data of two files.
 @discussion VNOP_EXCHANGE() is currently only called by the exchangedata() system call.  It will only
 be applied to files on the same volume.
 @param fvp First vnode.
 @param tvp Second vnode.
 @param options Unused.
 @param ctx Context to authenticate for exchangedata request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_EXCHANGE(vnode_t, vnode_t, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_revoke_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	int a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_REVOKE
 @abstract Call down to a filesystem to invalidate all open file descriptors for a vnode.
 @discussion This function is typically called as part of a TTY revoke, but can also be
 used on regular files.  Most filesystems simply use nop_revoke(), which calls vn_revoke(),
 as their revoke vnop implementation.
 @param vp The vnode to revoke.
 @param flags Unused.
 @param ctx Context to authenticate for revoke request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_REVOKE(vnode_t, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_mmap_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	int a_fflags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_MMAP
 @abstract Notify a filesystem that a file is being mmap-ed.
 @discussion VNOP_MMAP is an advisory calldown to say that the system is mmap-ing a file.  
 @param vp The vnode being mmapped.
 @param flags Memory protection: PROT_READ, PROT_WRITE, PROT_EXEC.
 @param ctx Context to authenticate for mmap request.
 @return 0 for success; all errors except EPERM are ignored.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_MMAP(vnode_t, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_mnomap_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	vfs_context_t a_context;
};

/*!
 @function VNOP_MNOMAP
 @abstract Inform a filesystem that a file is no longer mapped.
 @discussion In general, no action is required of a filesystem for VNOP_MNOMAP.
 @param vp The vnode which is no longer mapped.
 @param ctx Context to authenticate for mnomap request.
 @return Return value is ignored.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_MNOMAP(vnode_t, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_fsync_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	int a_waitfor;
	vfs_context_t a_context;
};

/*!
 @function VNOP_FSYNC
 @abstract Call down to a filesystem to synchronize a file with on-disk state.
 @discussion VNOP_FSYNC is called whenever we need to make sure that a file's data has been
 pushed to backing store, for example when recycling; it is also the heart of the fsync() system call.
 @param vp The vnode whose data to flush to backing store.  
 @param ctx Context to authenticate for fsync request.
 @return 0 for success, else an error code.
 */
extern errno_t VNOP_FSYNC(vnode_t vp, int waitfor, vfs_context_t ctx);

struct vnop_remove_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_dvp;
	vnode_t a_vp;
	struct componentname *a_cnp;
	int a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_REMOVE
 @abstract Call down to a filesystem to delete a file.
 @discussion VNOP_REMOVE is called to remove a file from a filesystem's namespace, for example by unlink().
 It can operate on regular files, named pipes, special files, and in some cases on directories.
 @param dvp Directory in which to delete a file.
 @param vp The file to delete.
 @param cnp Filename information.
 @param ctx Context to authenticate for fsync request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_REMOVE(vnode_t, vnode_t, struct componentname *, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

#ifdef KERNEL_PRIVATE
struct vnop_compound_remove_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_dvp;				/* Directory in which to lookup and remove */
	vnode_t *a_vpp;				/* File to remove; may or may not point to NULL pointer */
	struct componentname *a_cnp;		/* Name of file to remove */
	struct vnode_attr *a_vap;		/* Destination for file attributes on successful delete */
	uint32_t a_flags;			/* Control flags (unused) */
	vfs_context_t a_context;		/* Authorization context */
	int (*a_remove_authorizer)(		/* Authorizer callback */
			vnode_t dvp, 			/* Directory in which to delete */
			vnode_t vp, 			/* File to delete */
			struct componentname *cnp, 	/* As passed to VNOP */
			vfs_context_t ctx, 		/* As passed to VNOP */
			void *reserved);		/* Always NULL */
	void *a_reserved;			/* Unused */
};
#endif /* KERNEL_PRIVATE */

#ifdef BSD_KERNEL_PRIVATE 
extern errno_t VNOP_COMPOUND_REMOVE(vnode_t, vnode_t*, struct nameidata *, int32_t flags, struct vnode_attr *vap, vfs_context_t);
#endif 
struct vnop_link_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	vnode_t a_tdvp;
	struct componentname *a_cnp;
	vfs_context_t a_context;
};

/*!
 @function VNOP_LINK
 @abstract Call down to a filesystem to create a hardlink to a file.
 @discussion See "man 2 link".
 @param vp File to link to.
 @param dvp Directory in which to create the link.
 @param cnp Filename information for new link.
 @param ctx Context to authenticate for link request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_LINK(vnode_t, vnode_t, struct componentname *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_rename_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_fdvp;
	vnode_t a_fvp;
	struct componentname *a_fcnp;
	vnode_t a_tdvp;
	vnode_t a_tvp;
	struct componentname *a_tcnp;
	vfs_context_t a_context;
};

/*!
 @function VNOP_RENAME
 @abstract Call down to a filesystem to rename a file.
 @discussion VNOP_RENAME() will only be called with a source and target on the same volume.
 @param fdvp Directory in which source file resides.
 @param fvp File being renamed.
 @param fcnp Name information for source file.
 @param tdvp Directory file is being moved to.
 @param tvp Existing file with same name as target, should one exist.
 @param tcnp Name information for target path.
 @param ctx Context to authenticate for rename request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_RENAME(vnode_t, vnode_t, struct componentname *, vnode_t, vnode_t, struct componentname *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

typedef unsigned int vfs_rename_flags_t;

// Must match sys/stdio.h
enum {
	VFS_RENAME_SECLUDE	 	= 0x00000001,
	VFS_RENAME_SWAP			= 0x00000002,
	VFS_RENAME_EXCL			= 0x00000004,

	VFS_RENAME_FLAGS_MASK	= (VFS_RENAME_SECLUDE | VFS_RENAME_SWAP
							   | VFS_RENAME_EXCL),
};

struct vnop_renamex_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_fdvp;
	vnode_t a_fvp;
	struct componentname *a_fcnp;
	vnode_t a_tdvp;
	vnode_t a_tvp;
	struct componentname *a_tcnp;
	struct vnode_attr *a_vap;		// Reserved for future use
	vfs_rename_flags_t a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_RENAMEX
 @abstract Call down to a filesystem to rename a file.
 @discussion VNOP_RENAMEX() will only be called with a source and target on the same volume.
 @param fdvp Directory in which source file resides.
 @param fvp File being renamed.
 @param fcnp Name information for source file.
 @param tdvp Directory file is being moved to.
 @param tvp Existing file with same name as target, should one exist.
 @param tcnp Name information for target path.
 @param flags Control certain rename semantics.
 @param ctx Context to authenticate for rename request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_RENAMEX(vnode_t, vnode_t, struct componentname *, vnode_t, vnode_t, struct componentname *, vfs_rename_flags_t, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

#ifdef KERNEL_PRIVATE
struct vnop_compound_rename_args {
	struct vnodeop_desc *a_desc;

	vnode_t a_fdvp;			/* Directory from which to rename */
	vnode_t *a_fvpp;		/* Vnode to rename (can point to a NULL pointer) */
	struct componentname *a_fcnp;	/* Source name */
	struct vnode_attr *a_fvap;	

	vnode_t a_tdvp;			/* Directory to which to rename */
	vnode_t *a_tvpp;		/* Vnode to rename over (can point to a NULL pointer) */
	struct componentname *a_tcnp;	/* Destination name */
	struct vnode_attr *a_tvap;

	uint32_t a_flags;		/* Control flags: currently unused */
	vfs_context_t a_context;	/* Authorization context */
	int (*a_rename_authorizer)(			/* Authorization callback */
			vnode_t fdvp, 			/* As passed to VNOP */
			vnode_t fvp, 			/* Vnode to rename */
			struct componentname *fcnp, 	/* As passed to VNOP */
			vnode_t tdvp, 			/* As passed to VNOP */
			vnode_t tvp, 			/* Vnode to rename over (can be NULL) */
			struct componentname *tcnp,	/* As passed to VNOP */
			vfs_context_t ctx, 		/* As passed to VNOP */
			void *reserved);		/* Always NULL */
	void *a_reserved;		/* Currently unused */
};
#endif /* KERNEL_PRIVATE */

#ifdef XNU_KERNEL_PRIVATE
errno_t 
VNOP_COMPOUND_RENAME( 
		struct vnode *fdvp,  struct vnode **fvpp,  struct componentname *fcnp, struct vnode_attr *fvap,
             	struct vnode *tdvp,  struct vnode **tvpp,  struct componentname *tcnp, struct vnode_attr *tvap,  
	     	uint32_t flags,vfs_context_t ctx);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_mkdir_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_dvp;
	vnode_t *a_vpp;
	struct componentname *a_cnp;
	struct vnode_attr *a_vap;
	vfs_context_t a_context;
};

/*!
 @function VNOP_MKDIR
 @abstract Call down to a filesystem to create a directory.
 @discussion The newly created directory should be returned with an iocount which will be dropped by the caller.
 @param dvp Directory in which to create new directory.
 @param vpp Destination for pointer to new directory's vnode.
 @param cnp Name information for new directory.
 @param vap Attributes for new directory.
 @param ctx Context to authenticate for mkdir request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_MKDIR(vnode_t, vnode_t *, struct componentname *, struct vnode_attr *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */


#ifdef KERNEL_PRIVATE
struct vnop_compound_mkdir_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_dvp;			/* Directory in which to create */
	vnode_t *a_vpp;			/* Destination for found or created vnode */
	struct componentname *a_cnp;	/* Name of directory to create */
	struct vnode_attr *a_vap;	/* Creation attributes */
	uint32_t a_flags;		/* Control flags (unused) */
	vfs_context_t a_context;	/* Authorization context */
#if 0
	int (*a_mkdir_authorizer)(vnode_t dvp, struct componentname *cnp, struct vnode_attr *vap, vfs_context_t ctx, void *reserved);
#endif /* 0 */
	void *a_reserved;		/* Unused */
};
#endif /* KERNEL_PRIVATE */

#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_COMPOUND_MKDIR(vnode_t, vnode_t *, struct nameidata *, struct vnode_attr *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_rmdir_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_dvp;
	vnode_t a_vp;
	struct componentname *a_cnp;
	vfs_context_t a_context;
};

/*!
 @function VNOP_RMDIR
 @abstract Call down to a filesystem to delete a directory.
 @param dvp Parent of directory to be removed.
 @param vp Directory to remove.
 @param cnp Name information for directory to be deleted.
 @param ctx Context to authenticate for rmdir request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_RMDIR(vnode_t, vnode_t, struct componentname *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

#ifdef KERNEL_PRIVATE
struct vnop_compound_rmdir_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_dvp;				/* Directory in which to look up and delete */
	vnode_t *a_vpp;				/* Destination for found vnode */
	struct componentname *a_cnp;		/* Name to delete */
	struct vnode_attr *a_vap;		/* Location in which to store attributes if delete succeeds (can be NULL) */
	uint32_t a_flags;			/* Control flags (currently unused) */
	vfs_context_t a_context;		/* Context for authorization */
	int (*a_rmdir_authorizer)(		/* Authorization callback */
			vnode_t dvp, 			/* As passed to VNOP */
			vnode_t vp, 			/* Directory to delete */
			struct componentname *cnp, 	/* As passed to VNOP */
			vfs_context_t ctx, 		/* As passed to VNOP */
			void *reserved); 		/* Always NULL */
	void *a_reserved;			/* Unused */
};
#endif /* KERNEL_PRIVATE */

#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_COMPOUND_RMDIR(vnode_t, vnode_t*, struct nameidata *, struct vnode_attr *vap, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */


struct vnop_symlink_args {
       struct vnodeop_desc *a_desc;
       vnode_t a_dvp;
       vnode_t *a_vpp;
       struct componentname *a_cnp;
       struct vnode_attr *a_vap;
       char *a_target;
       vfs_context_t a_context;
};

/*!
 @function VNOP_SYMLINK
 @abstract Call down to a filesystem to create a symbolic link.
 @param If VNOP_SYMLINK() is successful, the new file should be returned with an iocount which will
 be dropped by the caller.  VFS does not ensure that the target path will have a length shorter
 than the max symlink length for the filesystem.
 @param dvp Parent directory for new symlink file.
 @param vpp 
 @param cnp Name information for new symlink.
 @param vap Attributes for symlink.
 @param target Path for symlink to store; for "ln -s /var/vardir linktovardir", "target" would be "/var/vardir"
 @param ctx Context to authenticate for symlink request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_SYMLINK(vnode_t, vnode_t *, struct componentname *, struct vnode_attr *, char *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

/*
 *
 *  When VNOP_READDIR is called from the NFS Server, the nfs_data
 *  argument is non-NULL.
 *
 *  The value of nfs_eofflag should be set to TRUE if the end of
 *  the directory was reached while reading.
 *
 *  The directory seek offset (cookies) are returned to the NFS client and
 *  may be used later to restart a directory read part way through
 *  the directory. There is one cookie returned for each directory
 *  entry returned and its size is determince from nfs_sizeofcookie.
 *  The value of the cookie should be the logical offset within the
 *  directory where the on-disc version of the appropriate directory
 *  entry starts. Memory for the cookies is allocated from M_TEMP
 *  and it is freed by the caller of VNOP_READDIR.
 *
 */

struct vnop_readdir_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	struct uio *a_uio;
	int a_flags;
	int *a_eofflag;
	int *a_numdirent;
	vfs_context_t a_context;
};

/*!
 @function VNOP_READDIR
 @abstract Call down to a filesystem to enumerate directory entries.
 @discussion VNOP_READDIR() packs a buffer with "struct dirent" directory entry representations as described
 by the "getdirentries" manual page.
 @param vp Directory to enumerate. 
 @param uio Destination information for resulting direntries.
 @param flags VNODE_READDIR_EXTENDED, VNODE_READDIR_REQSEEKOFF, VNODE_READDIR_SEEKOFF32: Apple-internal flags.
 @param eofflag Should be set to 1 if the end of the directory has been reached. 
 @param numdirent Should be set to number of entries written into buffer.
 @param ctx Context to authenticate for readdir request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_READDIR(vnode_t, struct uio *, int, int *, int *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_readdirattr_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	struct attrlist *a_alist;
	struct uio *a_uio;
	uint32_t a_maxcount;
	uint32_t a_options;
	uint32_t *a_newstate;
	int *a_eofflag;
	uint32_t *a_actualcount;
	vfs_context_t a_context;
};

/*!
 @function VNOP_READDIRATTR
 @abstract Call down to get file attributes for many files in a directory at once.
 @discussion VNOP_READDIRATTR() packs a buffer  with file attributes, as if the results of many "getattrlist" calls.
 @param vp Directory in which to enumerate entries' attributes.
 @param alist Which attributes are wanted for each directory entry.
 @param uio Destination information for resulting attributes.
 @param maxcount Maximum count of files to get attributes for.
 @param options FSOPT_NOFOLLOW: do not follow symbolic links. FSOPT_NOINMEMUPDATE: do not use data which have been
 updated since an inode was loaded into memory.
 @param newstate The "newstate" should be set to a value which changes if the contents of a directory change
 through an addition or deletion but stays the same otherwise.
 @param eofflag Should be set to 1 if the end of the directory has been reached. 
 @param actualcount Should be set to number of files whose attributes were  written into buffer.
 @param ctx Context to authenticate for readdirattr request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_READDIRATTR(vnode_t, struct attrlist *, struct uio *, uint32_t, uint32_t, uint32_t *, int *, uint32_t *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_getattrlistbulk_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	struct attrlist *a_alist;
	struct vnode_attr *a_vap;
	struct uio *a_uio;
	void *a_private;
	uint64_t a_options;
	int32_t *a_eofflag;
	int32_t *a_actualcount;
	vfs_context_t a_context;
};

/*!
 @function VNOP_GETATTRLISTBULK
 @abstract Call down to get file attributes for many files in a directory at once.
 @discussion VNOP_GETATTRLISTBULK() packs a buffer  with file attributes, as if the results of many "getattrlist" calls.
 @param vp Directory in which to enumerate entries' attributes.
 @param alist Which attributes are wanted for each directory entry.
 @param uio Destination information for resulting attributes.
 @param vap initialised vnode_attr structure pointer. This structure also has memory allocated (MAXPATHLEN bytes) and assigned to the va_name field for filesystems to use.
 @param private reserved for future use.
 @param options
 @param eofflag Should be set to 1 if the end of the directory has been reached.
 @param actualcount Should be set to number of files whose attributes were  written into buffer.
 @param ctx Context to authenticate for getattrlistbulk request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_GETATTRLISTBULK(vnode_t, struct attrlist *, struct vnode_attr *, uio_t,  void *, uint64_t, int32_t *, int32_t *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_readlink_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	struct uio *a_uio;
	vfs_context_t a_context;
};

/*!
 @function VNOP_READLINK
 @abstract Call down to a filesystem to get the pathname represented by a symbolic link.
 @discussion VNOP_READLINK() gets the path stored in a symbolic link; it is called by namei() and the readlink() system call.
 @param vp Symbolic link to read from.
 @param uio Destination information for link path.
 @param ctx Context to authenticate for readlink request.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_READLINK(vnode_t, struct uio *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_inactive_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	vfs_context_t a_context;
};

/*!
 @function VNOP_INACTIVE
 @abstract Notify a filesystem that the last usecount (persistent reference) on a vnode has been dropped. 
 @discussion VNOP_INACTVE() gives a filesystem a chance to aggressively release resources assocated with a vnode, perhaps
 even to call vnode_recycle(), but no action is prescribed; it is acceptable for VNOP_INACTIVE to be a no-op and
 to defer all reclamation until VNOP_RECLAIM().
 VNOP_INACTVE() will not be called on a vnode if no persistent reference is ever taken; an
 important example is a stat(), which takes an iocount, reads its data, and drops that iocount.  
 @param vp The vnode which is now inactive.
 @param ctx Context to authenticate for inactive message.
 @return 0 for success, else an error code, but return value is currently ignored.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_INACTIVE(vnode_t, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_reclaim_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	vfs_context_t a_context;
};

/*!
 @function VNOP_RECLAIM
 @abstract Release filesystem-internal resources for a vnode.
 @discussion VNOP_RECLAIM() is called as part of the process of recycling a vnode.  During
 a reclaim routine, a filesystem should remove a vnode from its hash and deallocate any resources
 allocated to that vnode.  VFS guarantees that when VNOP_RECLAIM() is called, there are no more
 iocount references on a vnode (though there may still be usecount references--these are invalidated
 by the reclaim) and that no more will be granted.  This means in practice that there will be no
 filesystem calls on the vnode being reclaimed until the reclaim has finished and the vnode has
 been reused.
 @param vp The vnode to reclaim.
 @param ctx Context to authenticate for reclaim.
 @return 0 for success, or an error code.  A nonzero return value results in a panic.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_RECLAIM(vnode_t, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_pathconf_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	int a_name;
	int32_t *a_retval;
	vfs_context_t a_context;
};

/*!
 @function VNOP_PATHCONF
 @abstract Query a filesystem for path properties.
 @param vp The vnode whose filesystem to query.
 @param name Which property to request: see unistd.h.  For example: _PC_CASE_SENSITIVE (is
 a filesystem case-sensitive?).  Only one property can be requested at a time.
 @param retval Destination for value of property.
 @param ctx Context to authenticate for pathconf request.
 @return 0 for success, or an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_PATHCONF(vnode_t, int, int32_t *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_advlock_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	caddr_t a_id;
	int a_op;
	struct flock *a_fl;
	int a_flags;
	vfs_context_t a_context;
	struct timespec *a_timeout;
};

/*!
 @function VNOP_ADVLOCK
 @abstract Aquire or release and advisory lock on a vnode.
 @discussion Advisory locking is somewhat complicated.  VNOP_ADVLOCK is overloaded for 
 both flock() and POSIX advisory locking usage, though not all filesystems support both (or any).  VFS
 provides an advisory locking mechanism for filesystems which can take advantage of it; vfs_setlocklocal()
 marks a filesystem as using VFS advisory locking support.
 @param vp The vnode to lock or unlock.
 @param id Identifier for lock holder: ignored by most filesystems.
 @param op Which locking operation: F_SETLK: set locking information about a region.  
 F_GETLK: get locking information about the specified region.  F_UNLCK: Unlock a region.   
 @param fl Description of file region to lock. l_whence is as with "lseek."  
 Includes a type: F_RDLCK (shared lock), F_UNLCK (unlock) , and F_WRLCK (exclusive lock).
 @param flags F_FLOCK: use flock() semantics. F_POSIX: use POSIX semantics.  F_WAIT: sleep if necessary.  
 F_PROV: Non-coelesced provisional lock (unused in xnu).
 @param ctx Context to authenticate for advisory locking request.
 @param timeout Timespec for timeout in case of F_SETLKWTIMEOUT.
 @return 0 for success, or an error code.  
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_ADVLOCK(vnode_t, caddr_t, int, struct flock *, int, vfs_context_t, struct timespec *);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_allocate_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	off_t a_length;
	u_int32_t a_flags;
	off_t *a_bytesallocated;
	off_t a_offset;
	vfs_context_t a_context;
};

/*!
 @function VNOP_ALLOCATE
 @abstract Pre-allocate space for a file.
 @discussion VNOP_ALLOCATE() changes the amount of backing store set aside to
 a file.  It can be used to either shrink or grow a file.  If the file shrinks,
 its ubc size will be modified accordingly, but if it grows, then the ubc size is unchanged;
 space is set aside without being actively used by the file.  VNOP_ALLOCATE() is currently only 
 called as part of the F_PREALLOCATE fcntl.  
 @param vp The vnode for which to preallocate space.
 @param length Desired preallocated file length.
 @param flags 
 PREALLOCATE:     preallocate allocation blocks.
 ALLOCATECONTIG:  allocate contigious space. 
 ALLOCATEALL:     allocate all requested space or no space at all.
 FREEREMAINDER:   deallocate allocated but unfilled blocks. 
 ALLOCATEFROMPEOF: allocate from the physical eof. 
 ALLOCATEFROMVOL:  allocate from the volume offset. 
 @param bytesallocated  Additional bytes set aside for file. Set to 0 if none are allocated
 OR if the file is contracted.
 @param offset Hint for where to find free blocks.
 @param ctx Context to authenticate for allocation request.
 @return 0 for success, or an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_ALLOCATE(vnode_t, off_t, u_int32_t, off_t *, off_t, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_pagein_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	upl_t a_pl;
	upl_offset_t a_pl_offset;
	off_t a_f_offset;
	size_t a_size;
	int a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_PAGEIN
 @abstract Pull file data into memory.
 @discussion VNOP_PAGEIN() is called by when a process faults on data mapped from a file or 
 when madvise() demands pre-fetching.  It is conceptually somewhat similar to VNOP_READ().  Filesystems
 are typically expected to call cluster_pagein() to handle the labor of mapping and committing the UPL.
 @param vp The vnode for which to page in data.
 @param pl UPL describing pages needing to be paged in.
 @param pl_offset Offset in UPL at which to start placing data.
 @param f_offset Offset in file of data needing to be paged in.
 @param size Amount of data to page in (in bytes).
 @param flags UPL-style flags: UPL_IOSYNC, UPL_NOCOMMIT, UPL_NORDAHEAD, UPL_VNODE_PAGER, UPL_MSYNC.
 Filesystems should generally leave it to the cluster layer to handle these flags. See the
 memory_object_types.h header in the kernel framework if interested.
 @param ctx Context to authenticate for pagein request.
 @return 0 for success, or an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_PAGEIN(vnode_t, upl_t, upl_offset_t, off_t, size_t, int, vfs_context_t); 
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_pageout_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	upl_t a_pl;
	upl_offset_t a_pl_offset;
	off_t a_f_offset;
	size_t a_size;
	int a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_PAGEOUT
 @abstract Write data from a mapped file back to disk.
 @discussion VNOP_PAGEOUT() is called when data from a mapped file needs to be flushed to disk, either
 because of an msync() call or due to memory pressure.  Filesystems are for the most part expected to
 just call cluster_pageout().   However, if they opt into the VFC_VFSVNOP_PAGEOUTV2 flag, then
 they will be responsible for creating their own UPLs.
 @param vp The vnode for which to page out data.
 @param pl UPL describing pages needed to be paged out.  If UPL is NULL, then it means the filesystem 
 has opted into VFC_VFSVNOP_PAGEOUTV2 semantics, which means that it will create and operate on its own UPLs
 as opposed to relying on the one passed down into the filesystem.  This means that the filesystem must be 
 responsible for N cluster_pageout calls for N dirty ranges in the UPL. 
 @param pl_offset Offset in UPL from which to start paging out data.  Under the new VFC_VFSVNOP_PAGEOUTV2
 semantics, this is the offset in the range specified that must be paged out if the associated page is dirty. 
 @param f_offset Offset in file of data needing to be paged out.    Under the new VFC_VFSVNOP_PAGEOUTV2
 semantics, this represents the offset in the file where we should start looking for dirty pages.
 @param size Amount of data to page out (in bytes).   Under VFC_VFSVNOP_PAGEOUTV2, this represents
 the size of the range to be considered.  The fileystem is free to extend or shrink the specified range
 to better fit its blocking model as long as the page at 'pl_offset' is included.
 @param flags UPL-style flags: UPL_IOSYNC, UPL_NOCOMMIT, UPL_NORDAHEAD, UPL_VNODE_PAGER, UPL_MSYNC.
 Filesystems should generally leave it to the cluster layer to handle these flags. See the
 memory_object_types.h header in the kernel framework if interested.
 @param ctx Context to authenticate for pageout request.
 @return 0 for success, or an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_PAGEOUT(vnode_t, upl_t, upl_offset_t, off_t, size_t, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_searchfs_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	void *a_searchparams1;
	void *a_searchparams2;
	struct attrlist *a_searchattrs;
	uint32_t a_maxmatches;
	struct timeval *a_timelimit;
	struct attrlist *a_returnattrs;
	uint32_t *a_nummatches;
	uint32_t a_scriptcode;
	uint32_t a_options;
	struct uio *a_uio;
	struct searchstate *a_searchstate;
	vfs_context_t a_context;
};

/*
   @function VNOP_SEARCHFS
   @abstract Search a filesystem quickly for files or directories that match the passed-in search criteria.
   @discussion VNOP_SEARCHFS is a getattrlist-based system call which is implemented almost entirely inside
   supported filesystems.  Callers provide a set of criteria to match against, and the filesystem is responsible
   for finding all files or directories that match the criteria.  Once these files or directories are found, 
   the user-requested attributes of these files is provided as output.  The set of searchable attributes is a 
   subset of the getattrlist  attributes.  For example, ATTR_CMN_UUID is not a valid searchable attribute as of 
   10.6.  A common usage scenario could be to request all files whose mod dates is greater than time X, less than 
   time Y, and provide the inode ID and filename of the matching objects as output.  
   @param vp The vnode representing the mountpoint of the filesystem to be searched.
   @param a_searchparams1 If one-argument search criteria is requested, the search criteria would go here. However,
   some search criteria, like ATTR_CMN_MODTIME, can be bounded.  The user could request files modified between time X
   and time Y.  In this case, the lower bound goes in a_searchparams1.
   @param a_searchparams2 If two-argument search criteria is requested, the upper bound goes in here.
   @param a_searchattrs Contains the getattrlist-style attribute bits which are requested by the current search.
   @param a_maxmatches The maximum number of matches to return in a single system call.
   @param a_timelimit The suggested maximum amount of time we can spend in the kernel to service this system call.  
   Filesystems should use this as a guide only, and set their own internal maximum time to avoid denial of service.
   @param a_returnattrs The getattrlist-style attributes to return for items in the filesystem that match the search 
   criteria above.
   @param a_scriptcode Currently ignored.
   @param a_uio The uio in which to write out the search matches.
   @param a_searchstate Sometimes searches cannot be completed in a single system call.  In this case, we provide 
   an identifier back to the user which indicates where to resume a previously-started search.  This is an opaque structure
   used by the filesystem to identify where to resume said search.
   @param a_context The context in which to perform the filesystem search.
   @return 0 on success, EAGAIN for searches which could not be completed in 1 call, and other ERRNOS as needed.
 */

#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_SEARCHFS(vnode_t, void *, void *, struct attrlist *, uint32_t, struct timeval *, struct attrlist *, uint32_t *, uint32_t, uint32_t, struct uio *, struct searchstate *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_copyfile_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_fvp;
	vnode_t a_tdvp;
	vnode_t a_tvp;
	struct componentname *a_tcnp;
	int a_mode;
	int a_flags;
	vfs_context_t a_context;
};

#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_COPYFILE(vnode_t, vnode_t, vnode_t, struct componentname *, int, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

typedef enum dir_clone_authorizer_op {
	OP_AUTHORIZE = 0,           /* request authorization of action */
	OP_VATTR_SETUP = 1,         /* query for attributes that are required for OP_AUTHORIZE */
	OP_VATTR_CLEANUP = 2        /* request to cleanup any state or free any memory allocated in OP_AUTHORIZE */
} dir_clone_authorizer_op_t;

struct vnop_clonefile_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_fvp;
	vnode_t a_dvp;
	vnode_t *a_vpp;
	struct componentname *a_cnp;
	struct vnode_attr *a_vap;
	uint32_t a_flags;
	vfs_context_t a_context;
	int (*a_dir_clone_authorizer)(	/* Authorization callback */
			struct vnode_attr *vap, /* attribute to be authorized */
			kauth_action_t action, /* action for which attribute is to be authorized */
			struct vnode_attr *dvap, /* target directory attributes */
			vnode_t sdvp, /* source directory vnode pointer (optional) */
			mount_t mp, /* mount point of filesystem */
			dir_clone_authorizer_op_t vattr_op, /* specific operation requested : setup, authorization or cleanup  */
			uint32_t flags, /* needs to have the value passed to a_flags */
			vfs_context_t ctx, 		/* As passed to VNOP */
			void *reserved);		/* Always NULL */
	void *a_reserved;		/* Currently unused */
};

/*!
 @function VNOP_CLONEFILE
 @abstract Call down to a filesystem to clone a filesystem object (regular file, directory or symbolic link.)
 @discussion If file creation succeeds, "vpp" should be returned with an iocount to be dropped by the caller.
 @param dvp Directory in which to clone object.
 @param vpp Destination for vnode for newly cloned object.
 @param cnp Description of name of object to clone.
 @param vap File creation properties, as seen in vnode_getattr().  Manipulated with VATTR_ISACTIVE, VATTR_RETURN,
 VATTR_SET_SUPPORTED, and so forth. All attributes not set here should either be copied
 from the source object
 or set to values which are used for creating new filesystem objects
 @param ctx Context against which to authenticate file creation.
 @return 0 for success or a filesystem-specific error.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_CLONEFILE(vnode_t, vnode_t, vnode_t *, struct componentname *, struct vnode_attr *, uint32_t, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_getxattr_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	const char * a_name;
	uio_t a_uio;
	size_t *a_size;
	int a_options;
	vfs_context_t a_context;
};
extern struct vnodeop_desc vnop_getxattr_desc;

/*!
 @function VNOP_GETXATTR
 @abstract Get extended file attributes.
 @param vp The vnode to get extended attributes for.
 @param name Which property to extract.
 @param uio Destination information for attribute value.
 @param size Should be set to the amount of data written.
 @param options XATTR_NOSECURITY: bypass security-checking.
 @param ctx Context to authenticate for getxattr request.
 @return 0 for success, or an error code.
 */
extern errno_t VNOP_GETXATTR(vnode_t vp, const char *name, uio_t uio, size_t *size, int options, vfs_context_t ctx);

struct vnop_setxattr_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	const char * a_name;
	uio_t a_uio;
	int a_options;
	vfs_context_t a_context;
};
extern struct vnodeop_desc vnop_setxattr_desc;

/*!
 @function VNOP_SETXATTR
 @abstract Set extended file attributes.
 @param vp The vnode to set extended attributes for.
 @param name Which property to extract.
 @param uio Source information for attribute value.
 @param options XATTR_NOSECURITY: bypass security-checking. XATTR_CREATE: set value, fail if exists.  
 XATTR_REPLACE: set value, fail if does not exist.
 @param ctx Context to authenticate for setxattr request.
 @return 0 for success, or an error code.
 */
extern errno_t VNOP_SETXATTR(vnode_t vp, const char *name, uio_t uio, int options, vfs_context_t ctx);

struct vnop_removexattr_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	const char * a_name;
	int a_options;
	vfs_context_t a_context;
};
extern struct vnodeop_desc vnop_removexattr_desc;

/*!
 @function VNOP_REMOVEXATTR
 @abstract Remove extended file attributes.
 @param vp The vnode from which to remove extended attributes.
 @param name Which attribute to delete.
 @param options XATTR_NOSECURITY: bypass security-checking. 
 @param ctx Context to authenticate for attribute delete request.
 @return 0 for success, or an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_REMOVEXATTR(vnode_t, const char *, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_listxattr_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	uio_t a_uio;
	size_t *a_size;
	int a_options;
	vfs_context_t a_context;
};
extern struct vnodeop_desc vnop_listxattr_desc;

/*!
 @function VNOP_LISTXATTR
 @abstract List extended attribute keys.
 @discussion Should write a sequence of unseparated, null-terminated extended-attribute
 names into the space described by the provided uio.  These keys can then be passed to
 getxattr() (and VNOP_GETXATTR()).
 @param vp The vnode for which to get extended attribute keys.
 @param uio Description of target memory for attribute keys.
 @param size Should be set to amount of data written to buffer.
 @param options XATTR_NOSECURITY: bypass security checking.
 @param ctx Context to authenticate for attribute name request.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_LISTXATTR(vnode_t, uio_t, size_t *, int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_blktooff_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	daddr64_t a_lblkno;
	off_t *a_offset;
};

/*!
 @function VNOP_BLKTOOFF
 @abstract Call down to a filesystem to convert a logical block number to a file offset.
 @discussion VNOP_BLKTOOFF() converts a logical block to a file offset in bytes.  That offset
 can be passed to VNOP_BLOCKMAP(), then, to get a physical block number--buf_strategy() does this.
 @param vp The vnode for which to convert a logical block to an offset.
 @param lblkno Logical block number to turn into offset.
 @param offset Destination for file offset.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_BLKTOOFF(vnode_t, daddr64_t, off_t *); 
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_offtoblk_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	off_t a_offset;
	daddr64_t *a_lblkno;
};

/*!
 @function VNOP_OFFTOBLK
 @abstract Call down to a filesystem to convert a file offset to a logical block number.
 @param vp The vnode for which to convert an offset to a logical block number.
 @param offset File offset to convert.
 @param lblkno Destination for corresponding logical block number.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_OFFTOBLK(vnode_t, off_t, daddr64_t *); 
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_blockmap_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	off_t a_foffset;
	size_t a_size;
	daddr64_t *a_bpn;
	size_t *a_run;
	void *a_poff;
	int a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_BLOCKMAP
 @abstract Call down to a filesystem to get information about the on-disk layout of a file region.
 @discussion VNOP_BLOCKMAP() returns the information required to pass a request for a contiguous region
 down to a device's strategy routine.
 @param vp The vnode for which to get on-disk information.
 @param foffset Offset (in bytes) at which region starts.
 @param size Size of region.
 @param bpn Destination for physical block number at which region begins on disk.
 @param run Destination for number of bytes which can be found contiguously on-disk before
 first discontinuity.
 @param poff Currently unused.
 @param flags VNODE_READ: request is for a read. VNODE_WRITE: request is for a write.
 @param ctx Context to authenticate for blockmap request; currently often set to NULL.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_BLOCKMAP(vnode_t, off_t, size_t, daddr64_t *, size_t *, void *,
                             int, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_strategy_args {
	struct vnodeop_desc *a_desc;
	struct buf *a_bp;
};

/*!
 @function VNOP_STRATEGY
 @abstract Initiate I/O on a file (both read and write).
 @discussion A filesystem strategy routine takes a buffer, performs whatever manipulations are necessary for passing 
 the I/O request down to the device layer, and calls the appropriate device's strategy routine.  Most filesystems should 
 just call buf_strategy() with "bp" as the argument.
 @param bp Complete specificiation of requested I/O: region of data involved, whether request is for read or write, and so on.
 @return 0 for success, else an error code.
 */
extern errno_t VNOP_STRATEGY(struct buf *bp);

struct vnop_bwrite_args {
	struct vnodeop_desc *a_desc;
	buf_t a_bp;
};

/*!
 @function VNOP_BWRITE
 @abstract Write a buffer to backing store.
 @discussion VNOP_BWRITE() is called by buf_bawrite() (asynchronous write) and potentially by buf_bdwrite() (delayed write)
 but not by buf_bwrite().  A filesystem may choose to perform some kind of manipulation of the buffer in this routine; it
 generally will end up calling VFS's default implementation, vn_bwrite() (which calls buf_bwrite() without further ado).
 @param bp The buffer to write.
 @return 0 for success, else an error code.
 */
extern errno_t VNOP_BWRITE(buf_t bp);

struct vnop_kqfilt_add_args {
	struct vnodeop_desc *a_desc;
	struct vnode *a_vp;
	struct knote *a_kn;
	vfs_context_t a_context;
};
extern struct vnodeop_desc vnop_kqfilt_add_desc;

#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_KQFILT_ADD(vnode_t , struct knote *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_kqfilt_remove_args {
	struct vnodeop_desc *a_desc;
	struct vnode *a_vp;
	uintptr_t a_ident;
	vfs_context_t a_context;
};
extern struct vnodeop_desc vnop_kqfilt_remove_desc;

#ifdef XNU_KERNEL_PRIVATE
errno_t VNOP_KQFILT_REMOVE(vnode_t , uintptr_t , vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */


#ifdef KERNEL_PRIVATE
#define VNODE_MONITOR_BEGIN 	0x01
#define VNODE_MONITOR_END	0x02
#define VNODE_MONITOR_UPDATE	0x04
struct vnop_monitor_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	uint32_t a_events;
	uint32_t a_flags;
	void *a_handle;
	vfs_context_t a_context;
};
extern struct vnodeop_desc vnop_monitor_desc;
#endif /* KERNEL_PRIVATE */

#ifdef XNU_KERNEL_PRIVATE
/*!
 @function VNOP_MONITOR
 @abstract Indicate to a filesystem that the number of watchers of a file has changed.
 @param vp The vnode whose watch state has changed.
 @param events Unused.  Filesystems can ignore this parameter.
 @param flags Type of change to the watch state.  VNODE_MONITOR_BEGIN is passed when the kernel
 begins tracking a new watcher of a file.  VNODE_MONITOR_END is passed when a watcher stops watching a file. 
 VNODE_MONITOR_UPDATE is currently unused.  A filesystem is guaranteed that each VNODE_MONITOR_BEGIN
 will be matched by a VNODE_MONITOR_END with the same "handle" argument.
 @param handle Unique identifier for a given watcher. A VNODE_MONITOR_BEGIN for a given handle will be matched with a 
 VNODE_MONITOR_END for the same handle; a filesystem need not consider this parameter unless
 it for some reason wants be able to match specific VNOP_MONITOR calls rather than just keeping
 a count.  
 @param ctx The context which is starting to monitor a file or ending a watch on a file.  A matching
 pair of VNODE_MONITOR_BEGIN and VNODE_MONITOR_END need not have the same context.
 @discussion VNOP_MONITOR() is intended to let networked filesystems know when they should bother
 listening for changes to files which occur remotely, so that they can post notifications using
 vnode_notify().  Local filesystems should not implement a monitor vnop.
 It is called when there is a new watcher for a file or when a watcher for a file goes away.  
 Each BEGIN will be matched with an END with the same handle.  Note that vnode_ismonitored() can
 be used to see if there are currently watchers for a file.
 */
errno_t VNOP_MONITOR(vnode_t vp, uint32_t events, uint32_t flags, void *handle, vfs_context_t ctx);
#endif /* XNU_KERNEL_PRIVATE */

struct label;
struct vnop_setlabel_args {
	struct vnodeop_desc *a_desc;
	struct vnode *a_vp;
	struct label *a_vl;
	vfs_context_t a_context;
};
extern struct vnodeop_desc vnop_setlabel_desc;

/*!
 @function VNOP_SETLABEL
 @abstract Associate a MACF label with a file.
 @param vp The vnode to label.
 @param label The desired label.
 @param ctx Context to authenticate for label change.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
errno_t VNOP_SETLABEL(vnode_t, struct label *, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

#ifdef __APPLE_API_UNSTABLE

#if NAMEDSTREAMS

enum nsoperation	{ NS_OPEN, NS_CREATE, NS_DELETE };

/* a_flags for vnop_getnamedstream_args: */
#define NS_GETRAWENCRYPTED 0x00000001

struct vnop_getnamedstream_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	vnode_t *a_svpp;
	const char *a_name;
	enum nsoperation a_operation;
	int a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_GETNAMEDSTREAM
 @abstract Get a named stream associated with a file.
 @discussion If this call sucecss, svpp should be returned with an iocount which the caller
 will drop.  VFS provides a facility for simulating named streams when interacting with filesystems
 which do not support them.
 @param vp The vnode for which to get a named stream.
 @param svpp Destination for pointer to named stream's vnode.
 @param name The name of the named stream, e.g. "com.apple.ResourceFork".
 @param operation Operation to perform.  In HFS and AFP, this parameter is only considered as follows:
 if the resource fork has not been opened and the operation is not NS_OPEN, fail with ENOATTR.  Currently
 only passed as NS_OPEN by VFS.
 @param flags Flags used to control getnamedstream behavior. Currently only used for raw-encrypted-requests.
 @param ctx Context to authenticate for getting named stream.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_GETNAMEDSTREAM(vnode_t, vnode_t *, const char *, enum nsoperation, int flags, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_makenamedstream_args {
	struct vnodeop_desc *a_desc;
	vnode_t *a_svpp;
	vnode_t a_vp;
	const char *a_name;
	int a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_MAKENAMEDSTREAM
 @abstract Create a named stream associated with a file.
 @discussion If this call succeeds, svpp should be returned with an iocount which the caller will drop.
 VFS provides a facility for simulating named streams when interacting with filesystems
 which do not support them. 
 @param vp The vnode for which to get a named stream.
 @param svpp Destination for pointer to named stream's vnode.
 @param name The name of the named stream, e.g. "com.apple.ResourceFork".
 @param flags Currently unused.
 @param ctx Context to authenticate creating named stream.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_MAKENAMEDSTREAM(vnode_t, vnode_t *, const char *, int flags, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

struct vnop_removenamedstream_args {
	struct vnodeop_desc *a_desc;
	vnode_t a_vp;
	vnode_t a_svp;
	const char *a_name;
	int a_flags;
	vfs_context_t a_context;
};

/*!
 @function VNOP_REMOVENAMEDSTREAM
 @abstract Delete a named stream associated with a file.
 @discussion  VFS provides a facility for simulating named streams when interacting with filesystems
 which do not support them. 
 @param vp The vnode to which the named stream belongs.
 @param svp The named stream's vnode.
 @param name The name of the named stream, e.g. "com.apple.ResourceFork".
 @param flags Currently unused.
 @param ctx Context to authenticate deleting named stream.
 @return 0 for success, else an error code.
 */
#ifdef XNU_KERNEL_PRIVATE
extern errno_t VNOP_REMOVENAMEDSTREAM(vnode_t, vnode_t, const char *, int flags, vfs_context_t);
#endif /* XNU_KERNEL_PRIVATE */

#endif // NAMEDSTREAMS

#endif // defined(__APPLE_API_UNSTABLE)

__END_DECLS

#endif /* KERNEL */

#endif /* !_SYS_VNODE_IF_H_ */