[apple/xnu.git] / bsd / hfs / hfs_cnode.h

/*
 * Copyright (c) 2002-2005 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@
 */
#ifndef _HFS_CNODE_H_
#define _HFS_CNODE_H_

#include <sys/appleapiopts.h>

#ifdef KERNEL
#ifdef __APPLE_API_PRIVATE
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/stat.h>
#include <sys/vnode.h>
#include <sys/quota.h>

#include <kern/locks.h>

#include <hfs/hfs_catalog.h>
#include <hfs/rangelist.h>


/*
 * The filefork is used to represent an HFS file fork (data or resource).
 * Reading or writing any of these fields requires holding cnode lock.
 */
struct filefork {
	struct cnode   *ff_cp;               /* cnode associated with this fork */
	struct rl_head  ff_invalidranges;    /* Areas of disk that should read back as zeroes */
	union {
	   void        *ffu_sysfileinfo;     /* additional info for system files */
	   char        *ffu_symlinkptr;      /* symbolic link pathname */
	} ff_union;
	struct cat_fork ff_data;             /* fork data (size, extents) */
};
typedef struct filefork filefork_t;

/* Aliases for common fields */
#define ff_size          ff_data.cf_size
#define ff_clumpsize     ff_data.cf_clump
#define ff_bytesread     ff_data.cf_bytesread
#define ff_blocks        ff_data.cf_blocks
#define ff_extents       ff_data.cf_extents
#define ff_unallocblocks ff_data.cf_vblocks

#define ff_symlinkptr    ff_union.ffu_symlinkptr
#define ff_sysfileinfo   ff_union.ffu_sysfileinfo


/* The btree code still needs these... */
#define fcbEOF           ff_size
#define fcbExtents       ff_extents
#define	fcbBTCBPtr       ff_sysfileinfo

typedef u_int8_t atomicflag_t;
 
/*
 * The cnode is used to represent each active (or recently active)
 * file or directory in the HFS filesystem.
 *
 * Reading or writing any of these fields requires holding c_lock.
 */
struct cnode {
	lck_rw_t                c_rwlock;       /* cnode's lock */
	void *                  c_lockowner;    /* cnode's lock owner (exclusive case only) */
	lck_rw_t                c_truncatelock; /* protects file from truncation during read/write */
	LIST_ENTRY(cnode)	c_hash;		/* cnode's hash chain */
	u_int32_t		c_flag;		/* cnode's runtime flags */
	u_int32_t		c_hflag;	/* cnode's flags for maintaining hash - protected by global hash lock */
	struct vnode		*c_vp;		/* vnode for data fork or dir */
	struct vnode		*c_rsrc_vp;	/* vnode for resource fork */
	struct vnode		*c_devvp;	/* vnode for block I/O */
	dev_t			c_dev;		/* cnode's device */
        struct dquot		*c_dquot[MAXQUOTAS]; /* cnode's quota info */
	struct klist		c_knotes;	/* knotes attached to this vnode */
	u_long			c_childhint;	/* catalog hint for children */
	struct cat_desc		c_desc;		/* cnode's descriptor */
	struct cat_attr		c_attr;		/* cnode's attributes */
	TAILQ_HEAD(hfs_hinthead, directoryhint) c_hintlist;  /* directory hint list */
  	int16_t			c_dirhinttag;	/* directory hint tag */
	union {
	    int16_t     cu_dirhintcnt;          /* directory hint count */
	    int16_t     cu_syslockcount;        /* system file use only */
	} c_union;
 	struct filefork		*c_datafork;	/* cnode's data fork */
	struct filefork		*c_rsrcfork;	/* cnode's rsrc fork */
	atomicflag_t	c_touch_acctime;
	atomicflag_t	c_touch_chgtime;
	atomicflag_t	c_touch_modtime;
};
typedef struct cnode cnode_t;

/* Aliases for common cnode fields */
#define c_cnid		c_desc.cd_cnid
#define c_hint		c_desc.cd_hint
#define c_parentcnid	c_desc.cd_parentcnid
#define c_encoding	c_desc.cd_encoding

#define c_fileid	c_attr.ca_fileid
#define c_mode		c_attr.ca_mode
#define c_nlink		c_attr.ca_nlink
#define c_uid		c_attr.ca_uid
#define c_gid		c_attr.ca_gid
#define c_rdev		c_attr.ca_rdev
#define c_atime		c_attr.ca_atime
#define c_mtime		c_attr.ca_mtime
#define c_ctime		c_attr.ca_ctime
#define c_itime		c_attr.ca_itime
#define c_btime		c_attr.ca_btime
#define c_flags		c_attr.ca_flags
#define c_finderinfo	c_attr.ca_finderinfo
#define c_blocks	c_attr.ca_blocks
#define c_attrblks	c_attr.ca_attrblks
#define c_entries	c_attr.ca_entries
#define c_zftimeout	c_childhint

#define c_dirhintcnt    c_union.cu_dirhintcnt
#define c_syslockcount  c_union.cu_syslockcount


/* hash maintenance flags kept in c_hflag and protected by hfs_chash_mutex */
#define H_ALLOC		0x00001	/* CNode is being allocated */
#define H_ATTACH	0x00002	/* CNode is being attached to by another vnode */
#define	H_TRANSIT	0x00004	/* CNode is getting recycled  */
#define H_WAITING	0x00008	/* CNode is being waited for */


/* Runtime cnode flags (kept in c_flag) */
#define C_NEED_RVNODE_PUT  0x00001  /* Need to do a vnode_put on c_rsrc_vp after the unlock */
#define C_NEED_DVNODE_PUT  0x00002  /* Need to do a vnode_put on c_vp after the unlock */
#define C_ZFWANTSYNC	   0x00004  /* fsync requested and file has holes */
#define C_FROMSYNC         0x00008  /* fsync was called from sync */ 

#define C_MODIFIED         0x00010  /* CNode has been modified */
#define C_NOEXISTS         0x00020  /* CNode has been deleted, catalog entry is gone */
#define C_DELETED          0x00040  /* CNode has been marked to be deleted */
#define C_HARDLINK         0x00080  /* CNode is a hard link */

#define C_FORCEUPDATE      0x00100  /* force the catalog entry update */
#define C_HASXATTRS        0x00200  /* cnode has extended attributes */

#define C_NEED_DATA_SETSIZE  0x01000  /* Do a ubc_setsize(0) on c_rsrc_vp after the unlock */
#define C_NEED_RSRC_SETSIZE  0x02000  /* Do a ubc_setsize(0) on c_vp after the unlock */


#define ZFTIMELIMIT	(5 * 60)

/*
 * Convert between cnode pointers and vnode pointers
 */
#define VTOC(vp)	((struct cnode *)vnode_fsnode((vp)))

#define CTOV(cp,rsrc)	(((rsrc) && S_ISREG((cp)->c_mode)) ? \
			(cp)->c_rsrc_vp : (cp)->c_vp)

/*
 * Convert between vnode pointers and file forks
 *
 * Note: no CTOF since that is ambiguous
 */

#define FTOC(fp)	((fp)->ff_cp)

#define VTOF(vp)	((vp) == VTOC((vp))->c_rsrc_vp ?	\
			 VTOC((vp))->c_rsrcfork :		\
			 VTOC((vp))->c_datafork)

#define FTOV(fp)	((fp) == FTOC(fp)->c_rsrcfork ?		\
			 FTOC(fp)->c_rsrc_vp :			\
			 FTOC(fp)->c_vp)


/*
 * Test for a resource fork
 */
#define FORK_IS_RSRC(fp)	((fp) == FTOC(fp)->c_rsrcfork)

#define VNODE_IS_RSRC(vp)	((vp) == VTOC((vp))->c_rsrc_vp)


#define ATIME_ONDISK_ACCURACY	300


/* This overlays the FileID portion of NFS file handles. */
struct hfsfid {
	u_int32_t hfsfid_cnid;	/* Catalog node ID. */
	u_int32_t hfsfid_gen;	/* Generation number (create date). */
};


extern void hfs_touchtimes(struct hfsmount *, struct cnode *);

/*
 * HFS cnode hash functions.
 */
extern void  hfs_chashinit(void);
extern void  hfs_chashinsert(struct cnode *cp);
extern int   hfs_chashremove(struct cnode *cp);
extern void  hfs_chash_abort(struct cnode *cp);
extern void  hfs_chash_rehash(struct cnode *cp1, struct cnode *cp2);
extern void  hfs_chashwakeup(struct cnode *cp, int flags);
extern void  hfs_chash_mark_in_transit(struct cnode *cp);

extern struct vnode * hfs_chash_getvnode(dev_t dev, ino_t inum, int wantrsrc, int skiplock);
extern struct cnode * hfs_chash_getcnode(dev_t dev, ino_t inum, struct vnode **vpp, int wantrsrc, int skiplock);
extern int hfs_chash_snoop(dev_t, ino_t, int (*)(const struct cat_desc *,
                            const struct cat_attr *, void *), void *);
				
/*
 * HFS directory hint functions.
 */
extern directoryhint_t * hfs_getdirhint(struct cnode *, int);
extern void  hfs_reldirhint(struct cnode *, directoryhint_t *);
extern void  hfs_reldirhints(struct cnode *, int);

/*
 * HFS cnode lock functions.
 *
 *  HFS Locking Order:
 *
 *  1. cnode truncate lock (if needed)
 *  2. cnode lock (in parent-child order if related, otherwise by address order)
 *  3. journal (if needed)
 *  4. system files (as needed)
 *       A. Catalog B-tree file
 *       B. Attributes B-tree file
 *       C. Allocation Bitmap file (always exclusive, supports recursion)
 *       D. Overflow Extents B-tree file (always exclusive, supports recursion)
 *  5. hfs mount point (always last)
 *
 */
enum hfslocktype  {HFS_SHARED_LOCK = 1, HFS_EXCLUSIVE_LOCK = 2, HFS_FORCE_LOCK = 3};
#define HFS_SHARED_OWNER  (void *)0xffffffff

extern int hfs_lock(struct cnode *, enum hfslocktype);
extern int hfs_lockpair(struct cnode *, struct cnode *, enum hfslocktype);
extern int hfs_lockfour(struct cnode *, struct cnode *, struct cnode *, struct cnode *,
                        enum hfslocktype);

extern void hfs_unlock(struct cnode *);
extern void hfs_unlockpair(struct cnode *, struct cnode *);
extern void hfs_unlockfour(struct cnode *, struct cnode *, struct cnode *, struct cnode *);

extern void hfs_lock_truncate(struct cnode *, int);
extern void hfs_unlock_truncate(struct cnode *);

#endif /* __APPLE_API_PRIVATE */
#endif /* KERNEL */

#endif /* ! _HFS_CNODE_H_ */
Commit	Line	Data
9bccf70c	1	/*
91447636	2	* Copyright (c) 2002-2005 Apple Computer, Inc. All rights reserved.
9bccf70c	3	*
8f6c56a5	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
9bccf70c	5	*
8f6c56a5 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.
	14	*
	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
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
8ad349bb	24	* limitations under the License.
8f6c56a5 A	25	*
8f6c56a5 A	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
9bccf70c A	27	*/
	28	#ifndef _HFS_CNODE_H_
	29	#define _HFS_CNODE_H_
	30
	31	#include <sys/appleapiopts.h>
	32
	33	#ifdef KERNEL
	34	#ifdef __APPLE_API_PRIVATE
	35	#include <sys/types.h>
9bccf70c A	36	#include <sys/queue.h>
	37	#include <sys/stat.h>
	38	#include <sys/vnode.h>
	39	#include <sys/quota.h>
	40
91447636 A	41	#include <kern/locks.h>
91447636 A	42
9bccf70c A	43	#include <hfs/hfs_catalog.h>
	44	#include <hfs/rangelist.h>
	45
	46
	47	/*
	48	* The filefork is used to represent an HFS file fork (data or resource).
	49	* Reading or writing any of these fields requires holding cnode lock.
	50	*/
	51	struct filefork {
91447636 A	52	struct cnode ff_cp; / cnode associated with this fork */
91447636 A	53	struct rl_head ff_invalidranges; /* Areas of disk that should read back as zeroes */
9bccf70c	54	union {
91447636 A	55	void ffu_sysfileinfo; / additional info for system files */
	56	char ffu_symlinkptr; / symbolic link pathname */
	57	} ff_union;
	58	struct cat_fork ff_data; /* fork data (size, extents) */
9bccf70c	59	};
55e303ae	60	typedef struct filefork filefork_t;
9bccf70c A	61
9bccf70c A	62	/* Aliases for common fields */
91447636 A	63	#define ff_size ff_data.cf_size
	64	#define ff_clumpsize ff_data.cf_clump
	65	#define ff_bytesread ff_data.cf_bytesread
	66	#define ff_blocks ff_data.cf_blocks
	67	#define ff_extents ff_data.cf_extents
55e303ae A	68	#define ff_unallocblocks ff_data.cf_vblocks
55e303ae A	69
91447636 A	70	#define ff_symlinkptr ff_union.ffu_symlinkptr
91447636 A	71	#define ff_sysfileinfo ff_union.ffu_sysfileinfo
9bccf70c A	72
	73
	74	/* The btree code still needs these... */
91447636 A	75	#define fcbEOF ff_size
	76	#define fcbExtents ff_extents
	77	#define fcbBTCBPtr ff_sysfileinfo
9bccf70c	78
91447636 A	79	typedef u_int8_t atomicflag_t;
91447636 A	80
9bccf70c A	81	/*
	82	* The cnode is used to represent each active (or recently active)
	83	* file or directory in the HFS filesystem.
	84	*
	85	* Reading or writing any of these fields requires holding c_lock.
	86	*/
	87	struct cnode {
91447636 A	88	lck_rw_t c_rwlock; /* cnode's lock */
	89	void * c_lockowner; /* cnode's lock owner (exclusive case only) */
	90	lck_rw_t c_truncatelock; /* protects file from truncation during read/write */
9bccf70c A	91	LIST_ENTRY(cnode) c_hash; /* cnode's hash chain */
9bccf70c A	92	u_int32_t c_flag; /* cnode's runtime flags */
91447636	93	u_int32_t c_hflag; /* cnode's flags for maintaining hash - protected by global hash lock */
9bccf70c A	94	struct vnode c_vp; / vnode for data fork or dir */
	95	struct vnode c_rsrc_vp; / vnode for resource fork */
	96	struct vnode c_devvp; / vnode for block I/O */
	97	dev_t c_dev; /* cnode's device */
	98	struct dquot c_dquot[MAXQUOTAS]; / cnode's quota info */
55e303ae	99	struct klist c_knotes; /* knotes attached to this vnode */
91447636	100	u_long c_childhint; /* catalog hint for children */
9bccf70c A	101	struct cat_desc c_desc; /* cnode's descriptor */
9bccf70c A	102	struct cat_attr c_attr; /* cnode's attributes */
b36670ce	103	TAILQ_HEAD(hfs_hinthead, directoryhint) c_hintlist; /* directory hint list */
91447636 A	104	int16_t c_dirhinttag; /* directory hint tag */
	105	union {
	106	int16_t cu_dirhintcnt; /* directory hint count */
	107	int16_t cu_syslockcount; /* system file use only */
	108	} c_union;
9bccf70c A	109	struct filefork c_datafork; / cnode's data fork */
9bccf70c A	110	struct filefork c_rsrcfork; / cnode's rsrc fork */
91447636 A	111	atomicflag_t c_touch_acctime;
	112	atomicflag_t c_touch_chgtime;
	113	atomicflag_t c_touch_modtime;
9bccf70c	114	};
55e303ae	115	typedef struct cnode cnode_t;
9bccf70c A	116
	117	/* Aliases for common cnode fields */
	118	#define c_cnid c_desc.cd_cnid
	119	#define c_hint c_desc.cd_hint
	120	#define c_parentcnid c_desc.cd_parentcnid
	121	#define c_encoding c_desc.cd_encoding
	122
	123	#define c_fileid c_attr.ca_fileid
	124	#define c_mode c_attr.ca_mode
	125	#define c_nlink c_attr.ca_nlink
	126	#define c_uid c_attr.ca_uid
	127	#define c_gid c_attr.ca_gid
	128	#define c_rdev c_attr.ca_rdev
	129	#define c_atime c_attr.ca_atime
	130	#define c_mtime c_attr.ca_mtime
9bccf70c A	131	#define c_ctime c_attr.ca_ctime
	132	#define c_itime c_attr.ca_itime
	133	#define c_btime c_attr.ca_btime
	134	#define c_flags c_attr.ca_flags
	135	#define c_finderinfo c_attr.ca_finderinfo
	136	#define c_blocks c_attr.ca_blocks
91447636	137	#define c_attrblks c_attr.ca_attrblks
9bccf70c A	138	#define c_entries c_attr.ca_entries
	139	#define c_zftimeout c_childhint
	140
91447636 A	141	#define c_dirhintcnt c_union.cu_dirhintcnt
91447636 A	142	#define c_syslockcount c_union.cu_syslockcount
9bccf70c	143
55e303ae	144
91447636 A	145	/* hash maintenance flags kept in c_hflag and protected by hfs_chash_mutex */
	146	#define H_ALLOC 0x00001 /* CNode is being allocated */
	147	#define H_ATTACH 0x00002 /* CNode is being attached to by another vnode */
	148	#define H_TRANSIT 0x00004 /* CNode is getting recycled */
	149	#define H_WAITING 0x00008 /* CNode is being waited for */
	150
9bccf70c	151
91447636 A	152	/* Runtime cnode flags (kept in c_flag) */
	153	#define C_NEED_RVNODE_PUT 0x00001 /* Need to do a vnode_put on c_rsrc_vp after the unlock */
	154	#define C_NEED_DVNODE_PUT 0x00002 /* Need to do a vnode_put on c_vp after the unlock */
	155	#define C_ZFWANTSYNC 0x00004 /* fsync requested and file has holes */
	156	#define C_FROMSYNC 0x00008 /* fsync was called from sync */
9bccf70c	157
91447636 A	158	#define C_MODIFIED 0x00010 /* CNode has been modified */
	159	#define C_NOEXISTS 0x00020 /* CNode has been deleted, catalog entry is gone */
	160	#define C_DELETED 0x00040 /* CNode has been marked to be deleted */
	161	#define C_HARDLINK 0x00080 /* CNode is a hard link */
9bccf70c	162
91447636 A	163	#define C_FORCEUPDATE 0x00100 /* force the catalog entry update */
91447636 A	164	#define C_HASXATTRS 0x00200 /* cnode has extended attributes */
9bccf70c	165
89b3af67 A	166	#define C_NEED_DATA_SETSIZE 0x01000 /* Do a ubc_setsize(0) on c_rsrc_vp after the unlock */
	167	#define C_NEED_RSRC_SETSIZE 0x02000 /* Do a ubc_setsize(0) on c_vp after the unlock */
	168
9bccf70c A	169
	170	#define ZFTIMELIMIT (5 * 60)
	171
	172	/*
	173	* Convert between cnode pointers and vnode pointers
	174	*/
91447636	175	#define VTOC(vp) ((struct cnode *)vnode_fsnode((vp)))
9bccf70c A	176
	177	#define CTOV(cp,rsrc) (((rsrc) && S_ISREG((cp)->c_mode)) ? \
	178	(cp)->c_rsrc_vp : (cp)->c_vp)
	179
	180	/*
	181	* Convert between vnode pointers and file forks
	182	*
	183	* Note: no CTOF since that is ambiguous
	184	*/
	185
	186	#define FTOC(fp) ((fp)->ff_cp)
	187
	188	#define VTOF(vp) ((vp) == VTOC((vp))->c_rsrc_vp ? \
	189	VTOC((vp))->c_rsrcfork : \
	190	VTOC((vp))->c_datafork)
	191
	192	#define FTOV(fp) ((fp) == FTOC(fp)->c_rsrcfork ? \
	193	FTOC(fp)->c_rsrc_vp : \
	194	FTOC(fp)->c_vp)
	195
55e303ae	196
9bccf70c A	197	/*
	198	* Test for a resource fork
	199	*/
	200	#define FORK_IS_RSRC(fp) ((fp) == FTOC(fp)->c_rsrcfork)
	201
	202	#define VNODE_IS_RSRC(vp) ((vp) == VTOC((vp))->c_rsrc_vp)
	203
	204
55e303ae	205	#define ATIME_ONDISK_ACCURACY 300
9bccf70c	206
91447636 A	207
91447636 A	208	/* This overlays the FileID portion of NFS file handles. */
9bccf70c	209	struct hfsfid {
9bccf70c A	210	u_int32_t hfsfid_cnid; /* Catalog node ID. */
	211	u_int32_t hfsfid_gen; /* Generation number (create date). */
	212	};
	213
	214
91447636 A	215	extern void hfs_touchtimes(struct hfsmount , struct cnode );
91447636 A	216
9bccf70c A	217	/*
	218	* HFS cnode hash functions.
	219	*/
	220	extern void hfs_chashinit(void);
	221	extern void hfs_chashinsert(struct cnode *cp);
91447636 A	222	extern int hfs_chashremove(struct cnode *cp);
	223	extern void hfs_chash_abort(struct cnode *cp);
	224	extern void hfs_chash_rehash(struct cnode cp1, struct cnode cp2);
	225	extern void hfs_chashwakeup(struct cnode *cp, int flags);
	226	extern void hfs_chash_mark_in_transit(struct cnode *cp);
	227
	228	extern struct vnode * hfs_chash_getvnode(dev_t dev, ino_t inum, int wantrsrc, int skiplock);
	229	extern struct cnode * hfs_chash_getcnode(dev_t dev, ino_t inum, struct vnode **vpp, int wantrsrc, int skiplock);
	230	extern int hfs_chash_snoop(dev_t, ino_t, int ()(const struct cat_desc ,
	231	const struct cat_attr , void ), void *);
	232
	233	/*
	234	* HFS directory hint functions.
	235	*/
	236	extern directoryhint_t * hfs_getdirhint(struct cnode *, int);
	237	extern void hfs_reldirhint(struct cnode , directoryhint_t );
	238	extern void hfs_reldirhints(struct cnode *, int);
	239
	240	/*
	241	* HFS cnode lock functions.
	242	*
	243	* HFS Locking Order:
	244	*
	245	* 1. cnode truncate lock (if needed)
	246	* 2. cnode lock (in parent-child order if related, otherwise by address order)
	247	* 3. journal (if needed)
	248	* 4. system files (as needed)
	249	* A. Catalog B-tree file
	250	* B. Attributes B-tree file
	251	* C. Allocation Bitmap file (always exclusive, supports recursion)
	252	* D. Overflow Extents B-tree file (always exclusive, supports recursion)
	253	* 5. hfs mount point (always last)
	254	*
	255	*/
	256	enum hfslocktype {HFS_SHARED_LOCK = 1, HFS_EXCLUSIVE_LOCK = 2, HFS_FORCE_LOCK = 3};
	257	#define HFS_SHARED_OWNER (void *)0xffffffff
	258
	259	extern int hfs_lock(struct cnode *, enum hfslocktype);
	260	extern int hfs_lockpair(struct cnode , struct cnode , enum hfslocktype);
	261	extern int hfs_lockfour(struct cnode , struct cnode , struct cnode , struct cnode ,
	262	enum hfslocktype);
	263
	264	extern void hfs_unlock(struct cnode *);
	265	extern void hfs_unlockpair(struct cnode , struct cnode );
	266	extern void hfs_unlockfour(struct cnode , struct cnode , struct cnode , struct cnode );
	267
	268	extern void hfs_lock_truncate(struct cnode *, int);
	269	extern void hfs_unlock_truncate(struct cnode *);
9bccf70c A	270
	271	#endif /* __APPLE_API_PRIVATE */
	272	#endif /* KERNEL */
	273
	274	#endif /* ! _HFS_CNODE_H_ */