[apple/xnu.git] / bsd / miscfs / devfs / devfsdefs.h

/*
 * Copyright (c) 2000-2002 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 1997,1998 Julian Elischer.  All rights reserved.
 * julian@freebsd.org
 * 
 * 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.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``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 HOLDER 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.
 * 
 * devfsdefs.h
 */
/*
 * NOTICE: This file was modified by McAfee Research in 2004 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.
 */

/*
 * HISTORY
 *  8-April-1999 Dieter Siegmund (dieter@apple.com)
 *	Ported to from FreeBSD 3.1
 *	Removed unnecessary/unused defines
 *	Renamed structures/elements to clarify usage in code.
 */

#ifndef __DEVFS_DEVFSDEFS_H__
#define __DEVFS_DEVFSDEFS_H__

#include  <sys/appleapiopts.h>

#include <security/mac.h>

__BEGIN_DECLS
#ifdef __APPLE_API_PRIVATE
#define DEVMAXNAMESIZE 	32 		/* XXX */
#define DEVMAXPATHSIZE 	128		/* XXX */

typedef enum {
    DEV_DIR,
    DEV_BDEV,
    DEV_CDEV,
    DEV_SLNK,
#if FDESC
    DEV_DEVFD
#endif /* FDESC */
} devfstype_t;

extern int (**devfs_vnodeop_p)(void *);	/* our own vector array for dirs */
extern int (**devfs_spec_vnodeop_p)(void *); /* our own vector array for devs */
extern struct vfsops devfs_vfsops;

typedef	struct devnode		devnode_t;
typedef struct devdirent 	devdirent_t;
typedef union devnode_type 	devnode_type_t;

struct devfs_stats {
    int			nodes;
    int			entries;
    int			mounts;
    int			stringspace;
};

union devnode_type {
    dev_t		dev;
    struct {
	devdirent_t *	dirlist;
	devdirent_t * *	dirlast;
	devnode_t *	parent;
	devdirent_t *	myname;		/* my entry in .. */
	int		entrycount;
    }Dir;
    struct {
	char *		name;	/* must be allocated separately */
	int		namelen;
    }Slnk;
};

struct devnode
{
    devfstype_t		dn_type;
    /* 
     * Number of vnodes that point to this devnode.  Note, we do not
     * add another reference for a lookup which finds an existing
     * vnode; a reference is added when a vnode is created and removed
     * when a vnode is reclaimed.  A devnode will not be freed while
     * there are outstanding references.  A refcount can be added to
     * prevent the free of a devnode in situations where there is not
     * guaranteed to be a vnode holding a ref, but it is important to
	 * make sure that a deferred delete eventually happens if it is
 	 * blocked behind that reference.
     */
    int			dn_refcount;
    u_short		dn_mode;
    uid_t		dn_uid; 
    gid_t		dn_gid;
    struct timespec	dn_atime;/* time of last access */
    struct timespec	dn_mtime;/* time of last modification */
    struct timespec	dn_ctime;/* time file changed */
    int	(***dn_ops)(void *);/* yuk... pointer to pointer(s) to funcs */
    int			dn_links;/* how many file links does this node have? */
    struct devfsmount *	dn_dvm; /* the mount structure for this 'plane' */
    struct vnode *	dn_vn;	/* address of last vnode that represented us */
    int			dn_len;   /* of any associated info (e.g. dir data) */
    devdirent_t *	dn_linklist;/* circular list of hardlinks to this node */
    devnode_t *		dn_nextsibling;	/* the list of equivalent nodes */
    devnode_t * *	dn_prevsiblingp;/* backpointer for the above */
    devnode_type_t	dn_typeinfo;
    int			dn_change;
    int			dn_update;
    int			dn_access;
    int			dn_lflags;
    ino_t		dn_ino;
    int			(*dn_clone)(dev_t dev, int action); /* get minor # */
    struct label *	dn_label;	/* security label */
};

#define	DN_DELETE		0x02
#define	DN_CREATE		0x04
#define	DN_CREATEWAIT		0x08


struct devdirent
{
    /*-----------------------directory entry fields-------------*/
    char		de_name[DEVMAXNAMESIZE];
    devnode_t *		de_dnp;		/* the "inode" (devnode) pointer */
    devnode_t *		de_parent;	/* backpointer to the directory itself */
    devdirent_t *	de_next;	/* next object in this directory */
    devdirent_t *	*de_prevp;	/* previous pointer in directory linked list */
    devdirent_t *	de_nextlink;	/* next hardlink to this node */
    devdirent_t *	*de_prevlinkp;	/* previous hardlink pointer for this node */
};

extern devdirent_t * 		dev_root;
extern struct devfs_stats	devfs_stats;
extern lck_mtx_t	  	devfs_mutex;
extern lck_mtx_t	  	devfs_attr_mutex;

/*
 * Rules for front nodes:
 * Dirs hava a strict 1:1 relationship with their OWN devnode
 * Symlinks similarly
 * Device Nodes ALWAYS point to the devnode that is linked
 * to the Backing node. (with a ref count)
 */

/*
 * DEVFS specific per/mount information, used to link a monted fs to a
 * particular 'plane' of front nodes.
 */
struct devfsmount
{
    struct mount *	mount;	/* vfs mount struct for this fs	*/
    devdirent_t *	plane_root;/* the root of this 'plane'	*/
};

/*
 * Prototypes for DEVFS virtual filesystem operations
 */
#include <sys/lock.h>
#include <miscfs/devfs/devfs_proto.h>
#include <libkern/OSAtomic.h>		/* required for OSAddAtomic() */

//#define HIDDEN_MOUNTPOINT	1

/* misc */
#define M_DEVFSNAME	M_DEVFS
#define M_DEVFSNODE	M_DEVFS
#define M_DEVFSMNT	M_DEVFS

#define VTODN(vp)	((devnode_t *)(vp)->v_data)

#define DEVFS_LOCK()	lck_mtx_lock(&devfs_mutex)
#define DEVFS_UNLOCK()	lck_mtx_unlock(&devfs_mutex)

#define DEVFS_ATTR_LOCK_SPIN()	lck_mtx_lock_spin(&devfs_attr_mutex);
#define DEVFS_ATTR_UNLOCK()	lck_mtx_unlock(&devfs_attr_mutex);

/*
 * XXX all the (SInt32 *) casts below assume sizeof(int) == sizeof(long)
 */
static __inline__ void
DEVFS_INCR_ENTRIES(void)
{
    OSAddAtomic(1, &devfs_stats.entries);
}

static __inline__ void
DEVFS_DECR_ENTRIES(void)
{
    OSAddAtomic(-1, &devfs_stats.entries);
}

static __inline__ void
DEVFS_INCR_NODES(void)
{
    OSAddAtomic(1, &devfs_stats.nodes);
}

static __inline__ void
DEVFS_DECR_NODES(void)
{
    OSAddAtomic(-1, &devfs_stats.nodes);
}

static __inline__ void
DEVFS_INCR_MOUNTS(void)
{
    OSAddAtomic(1, &devfs_stats.mounts);
}

static __inline__ void
DEVFS_DECR_MOUNTS(void)
{
    OSAddAtomic(-1, &devfs_stats.mounts);
}

static __inline__ void
DEVFS_INCR_STRINGSPACE(int space)
{
    OSAddAtomic(space, &devfs_stats.stringspace);
}

static __inline__ void
DEVFS_DECR_STRINGSPACE(int space)
{
    OSAddAtomic(-space, &devfs_stats.stringspace);
}

/* 
 * Access, change, and modify times are protected by a separate lock,
 * which allows tty times to be updated (no more than once per second)
 * in the I/O path without too much fear of contention.
 *
 * For getattr, update times to current time if the last update was recent; 
 * preserve  legacy behavior that frequent stats can yield sub-second resolutions.  
 * If the last time is old, however, we know that the event that triggered
 * the need for an update was no more than 1s after the last update.  In that case,
 * use (last update + 1s) as the time, avoiding the illusion that last update happened
 * much later than it really did.
 */
#define DEVFS_LAZY_UPDATE_SECONDS	1

#define DEVFS_UPDATE_CHANGE		0x1
#define DEVFS_UPDATE_MOD		0x2
#define DEVFS_UPDATE_ACCESS		0x4

static __inline__ void
dn_copy_times(devnode_t * target, devnode_t * source)
{
    DEVFS_ATTR_LOCK_SPIN();
    target->dn_atime = source->dn_atime;
    target->dn_mtime = source->dn_mtime;
    target->dn_ctime = source->dn_ctime;
    DEVFS_ATTR_UNLOCK();
    return;
}

#ifdef BSD_KERNEL_PRIVATE
int 	devfs_make_symlink(devnode_t *dir_p, char *name, int mode, char *target, devdirent_t **newent);
#endif /* BSD_KERNEL_PRIVATE */

#endif /* __APPLE_API_PRIVATE */

__END_DECLS

#endif /* __DEVFS_DEVFSDEFS_H__ */
Commit	Line	Data
1c79356b	1	/*
5d5c5d0d A	2	* Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
5d5c5d0d A	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
8f6c56a5	14	*
2d21ac55 A	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/*
	29	* Copyright 1997,1998 Julian Elischer. All rights reserved.
	30	* julian@freebsd.org
	31	*
	32	* Redistribution and use in source and binary forms, with or without
	33	* modification, are permitted provided that the following conditions are
	34	* met:
	35	* 1. Redistributions of source code must retain the above copyright
	36	* notice, this list of conditions and the following disclaimer.
	37	* 2. Redistributions in binary form must reproduce the above copyright notice,
	38	* this list of conditions and the following disclaimer in the documentation
	39	* and/or other materials provided with the distribution.
	40	*
	41	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
	42	* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	43	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	44	* DISCLAIMED. IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
	45	* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	46	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
	47	* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	48	* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	49	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	50	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	51	* SUCH DAMAGE.
	52	*
	53	* devfsdefs.h
	54	*/
2d21ac55 A	55	/*
	56	* NOTICE: This file was modified by McAfee Research in 2004 to introduce
	57	* support for mandatory and extensible security protections. This notice
	58	* is included in support of clause 2.2 (b) of the Apple Public License,
	59	* Version 2.0.
	60	*/
1c79356b A	61
	62	/*
	63	* HISTORY
	64	* 8-April-1999 Dieter Siegmund (dieter@apple.com)
	65	* Ported to from FreeBSD 3.1
	66	* Removed unnecessary/unused defines
	67	* Renamed structures/elements to clarify usage in code.
	68	*/
	69
9bccf70c A	70	#ifndef __DEVFS_DEVFSDEFS_H__
9bccf70c A	71	#define __DEVFS_DEVFSDEFS_H__
1c79356b	72
9bccf70c A	73	#include <sys/appleapiopts.h>
9bccf70c A	74
2d21ac55 A	75	#include <security/mac.h>
2d21ac55 A	76
b0d623f7	77	__BEGIN_DECLS
9bccf70c	78	#ifdef __APPLE_API_PRIVATE
1c79356b A	79	#define DEVMAXNAMESIZE 32 /* XXX */
	80	#define DEVMAXPATHSIZE 128 /* XXX */
	81
	82	typedef enum {
	83	DEV_DIR,
	84	DEV_BDEV,
	85	DEV_CDEV,
b0d623f7 A	86	DEV_SLNK,
	87	#if FDESC
	88	DEV_DEVFD
	89	#endif /* FDESC */
1c79356b A	90	} devfstype_t;
	91
	92	extern int (*devfs_vnodeop_p)(void ); /* our own vector array for dirs */
	93	extern int (*devfs_spec_vnodeop_p)(void ); /* our own vector array for devs */
	94	extern struct vfsops devfs_vfsops;
	95
	96	typedef struct devnode devnode_t;
	97	typedef struct devdirent devdirent_t;
	98	typedef union devnode_type devnode_type_t;
	99
	100	struct devfs_stats {
	101	int nodes;
	102	int entries;
	103	int mounts;
	104	int stringspace;
	105	};
	106
	107	union devnode_type {
	108	dev_t dev;
	109	struct {
	110	devdirent_t * dirlist;
	111	devdirent_t * * dirlast;
	112	devnode_t * parent;
	113	devdirent_t * myname; /* my entry in .. */
	114	int entrycount;
	115	}Dir;
	116	struct {
	117	char * name; /* must be allocated separately */
	118	int namelen;
	119	}Slnk;
	120	};
	121
1c79356b A	122	struct devnode
	123	{
	124	devfstype_t dn_type;
b0d623f7 A	125	/*
	126	* Number of vnodes that point to this devnode. Note, we do not
	127	* add another reference for a lookup which finds an existing
	128	* vnode; a reference is added when a vnode is created and removed
	129	* when a vnode is reclaimed. A devnode will not be freed while
	130	* there are outstanding references. A refcount can be added to
	131	* prevent the free of a devnode in situations where there is not
	132	* guaranteed to be a vnode holding a ref, but it is important to
	133	* make sure that a deferred delete eventually happens if it is
	134	* blocked behind that reference.
	135	*/
	136	int dn_refcount;
1c79356b	137	u_short dn_mode;
0b4e3aa0 A	138	uid_t dn_uid;
0b4e3aa0 A	139	gid_t dn_gid;
1c79356b A	140	struct timespec dn_atime;/* time of last access */
	141	struct timespec dn_mtime;/* time of last modification */
	142	struct timespec dn_ctime;/* time file changed */
	143	int (**dn_ops)(void );/* yuk... pointer to pointer(s) to funcs */
	144	int dn_links;/* how many file links does this node have? */
	145	struct devfsmount * dn_dvm; /* the mount structure for this 'plane' */
	146	struct vnode * dn_vn; /* address of last vnode that represented us */
	147	int dn_len; /* of any associated info (e.g. dir data) */
	148	devdirent_t * dn_linklist;/* circular list of hardlinks to this node */
1c79356b A	149	devnode_t * dn_nextsibling; /* the list of equivalent nodes */
	150	devnode_t * * dn_prevsiblingp;/* backpointer for the above */
	151	devnode_type_t dn_typeinfo;
91447636 A	152	int dn_change;
	153	int dn_update;
	154	int dn_access;
b0d623f7 A	155	int dn_lflags;
b0d623f7 A	156	ino_t dn_ino;
2d21ac55 A	157	int (dn_clone)(dev_t dev, int action); / get minor # */
2d21ac55 A	158	struct label * dn_label; /* security label */
1c79356b A	159	};
1c79356b A	160
91447636 A	161	#define DN_DELETE 0x02
91447636 A	162	#define DN_CREATE 0x04
b0d623f7	163	#define DN_CREATEWAIT 0x08
91447636 A	164
91447636 A	165
1c79356b A	166	struct devdirent
	167	{
	168	/-----------------------directory entry fields-------------/
	169	char de_name[DEVMAXNAMESIZE];
	170	devnode_t * de_dnp; /* the "inode" (devnode) pointer */
	171	devnode_t * de_parent; /* backpointer to the directory itself */
	172	devdirent_t * de_next; /* next object in this directory */
	173	devdirent_t * de_prevp; / previous pointer in directory linked list */
	174	devdirent_t * de_nextlink; /* next hardlink to this node */
	175	devdirent_t * de_prevlinkp; / previous hardlink pointer for this node */
	176	};
	177
	178	extern devdirent_t * dev_root;
1c79356b	179	extern struct devfs_stats devfs_stats;
91447636	180	extern lck_mtx_t devfs_mutex;
6d2010ae	181	extern lck_mtx_t devfs_attr_mutex;
1c79356b A	182
	183	/*
	184	* Rules for front nodes:
	185	* Dirs hava a strict 1:1 relationship with their OWN devnode
	186	* Symlinks similarly
	187	* Device Nodes ALWAYS point to the devnode that is linked
	188	* to the Backing node. (with a ref count)
	189	*/
	190
	191	/*
	192	* DEVFS specific per/mount information, used to link a monted fs to a
	193	* particular 'plane' of front nodes.
	194	*/
	195	struct devfsmount
	196	{
	197	struct mount * mount; /* vfs mount struct for this fs */
	198	devdirent_t * plane_root;/* the root of this 'plane' */
	199	};
	200
	201	/*
	202	* Prototypes for DEVFS virtual filesystem operations
	203	*/
	204	#include <sys/lock.h>
	205	#include <miscfs/devfs/devfs_proto.h>
2d21ac55	206	#include <libkern/OSAtomic.h> /* required for OSAddAtomic() */
1c79356b A	207
	208	//#define HIDDEN_MOUNTPOINT 1
	209
	210	/* misc */
	211	#define M_DEVFSNAME M_DEVFS
	212	#define M_DEVFSNODE M_DEVFS
	213	#define M_DEVFSMNT M_DEVFS
	214
1c79356b	215	#define VTODN(vp) ((devnode_t *)(vp)->v_data)
1c79356b	216
91447636	217	#define DEVFS_LOCK() lck_mtx_lock(&devfs_mutex)
91447636 A	218	#define DEVFS_UNLOCK() lck_mtx_unlock(&devfs_mutex)
91447636 A	219
6d2010ae A	220	#define DEVFS_ATTR_LOCK_SPIN() lck_mtx_lock_spin(&devfs_attr_mutex);
6d2010ae A	221	#define DEVFS_ATTR_UNLOCK() lck_mtx_unlock(&devfs_attr_mutex);
1c79356b	222
2d21ac55 A	223	/*
	224	* XXX all the (SInt32 *) casts below assume sizeof(int) == sizeof(long)
	225	*/
1c79356b	226	static __inline__ void
2d21ac55	227	DEVFS_INCR_ENTRIES(void)
1c79356b	228	{
b0d623f7	229	OSAddAtomic(1, &devfs_stats.entries);
1c79356b A	230	}
	231
	232	static __inline__ void
2d21ac55	233	DEVFS_DECR_ENTRIES(void)
1c79356b	234	{
b0d623f7	235	OSAddAtomic(-1, &devfs_stats.entries);
1c79356b A	236	}
	237
	238	static __inline__ void
2d21ac55	239	DEVFS_INCR_NODES(void)
1c79356b	240	{
b0d623f7	241	OSAddAtomic(1, &devfs_stats.nodes);
1c79356b A	242	}
	243
	244	static __inline__ void
2d21ac55	245	DEVFS_DECR_NODES(void)
1c79356b	246	{
b0d623f7	247	OSAddAtomic(-1, &devfs_stats.nodes);
1c79356b A	248	}
	249
	250	static __inline__ void
2d21ac55	251	DEVFS_INCR_MOUNTS(void)
1c79356b	252	{
b0d623f7	253	OSAddAtomic(1, &devfs_stats.mounts);
1c79356b A	254	}
	255
	256	static __inline__ void
2d21ac55	257	DEVFS_DECR_MOUNTS(void)
1c79356b	258	{
b0d623f7	259	OSAddAtomic(-1, &devfs_stats.mounts);
1c79356b A	260	}
	261
	262	static __inline__ void
	263	DEVFS_INCR_STRINGSPACE(int space)
	264	{
b0d623f7	265	OSAddAtomic(space, &devfs_stats.stringspace);
1c79356b A	266	}
	267
	268	static __inline__ void
	269	DEVFS_DECR_STRINGSPACE(int space)
	270	{
b0d623f7	271	OSAddAtomic(-space, &devfs_stats.stringspace);
1c79356b A	272	}
1c79356b A	273
6d2010ae A	274	/*
	275	* Access, change, and modify times are protected by a separate lock,
	276	* which allows tty times to be updated (no more than once per second)
	277	* in the I/O path without too much fear of contention.
	278	*
	279	* For getattr, update times to current time if the last update was recent;
	280	* preserve legacy behavior that frequent stats can yield sub-second resolutions.
	281	* If the last time is old, however, we know that the event that triggered
	282	* the need for an update was no more than 1s after the last update. In that case,
	283	* use (last update + 1s) as the time, avoiding the illusion that last update happened
	284	* much later than it really did.
	285	*/
	286	#define DEVFS_LAZY_UPDATE_SECONDS 1
	287
	288	#define DEVFS_UPDATE_CHANGE 0x1
	289	#define DEVFS_UPDATE_MOD 0x2
	290	#define DEVFS_UPDATE_ACCESS 0x4
1c79356b A	291
	292	static __inline__ void
	293	dn_copy_times(devnode_t * target, devnode_t * source)
	294	{
6d2010ae	295	DEVFS_ATTR_LOCK_SPIN();
1c79356b A	296	target->dn_atime = source->dn_atime;
	297	target->dn_mtime = source->dn_mtime;
	298	target->dn_ctime = source->dn_ctime;
6d2010ae	299	DEVFS_ATTR_UNLOCK();
1c79356b A	300	return;
1c79356b A	301	}
b0d623f7 A	302
	303	#ifdef BSD_KERNEL_PRIVATE
	304	int devfs_make_symlink(devnode_t dir_p, char name, int mode, char target, devdirent_t *newent);
	305	#endif /* BSD_KERNEL_PRIVATE */
	306
9bccf70c	307	#endif /* __APPLE_API_PRIVATE */
b0d623f7 A	308
	309	__END_DECLS
	310
9bccf70c	311	#endif /* __DEVFS_DEVFSDEFS_H__ */