xref: /xnu-11215/bsd/sys/vnode.h (revision 4f1223e8)
1 /*
2  * Copyright (c) 2000-2024 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
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
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
29 /*
30  * Copyright (c) 1989, 1993
31  *	The Regents of the University of California.  All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  * 3. All advertising materials mentioning features or use of this software
42  *    must display the following acknowledgement:
43  *	This product includes software developed by the University of
44  *	California, Berkeley and its contributors.
45  * 4. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  *
61  *	@(#)vnode.h	8.17 (Berkeley) 5/20/95
62  */
63 
64 #ifndef _VNODE_H_
65 #define _VNODE_H_
66 
67 #include <stdint.h>
68 #include <sys/appleapiopts.h>
69 #include <sys/cdefs.h>
70 #ifdef KERNEL
71 #include <sys/kernel_types.h>
72 #include <sys/param.h>
73 #include <sys/signal.h>
74 #ifdef KERNEL_PRIVATE
75 #include <mach/mach_types.h>
76 #endif /* KERNEL_PRIVATE */
77 #else
78 #include <stdint.h>
79 #endif /* KERNEL */
80 
81 /*
82  * The vnode is the focus of all file activity in UNIX.  There is a
83  * unique vnode allocated for each active file, each current directory,
84  * each mounted-on file, text file, and the root.
85  */
86 
87 /*
88  * Vnode types.  VNON means no type.
89  */
90 enum vtype      {
91 	/* 0 */
92 	VNON,
93 	/* 1 - 5 */
94 	VREG, VDIR, VBLK, VCHR, VLNK,
95 	/* 6 - 10 */
96 	VSOCK, VFIFO, VBAD, VSTR, VCPLX
97 };
98 
99 /*
100  * Vnode tag types.
101  * These are for the benefit of external programs only (e.g., pstat)
102  * and should NEVER be inspected by the kernel.
103  */
104 enum vtagtype   {
105 	/* 0 */
106 	VT_NON,
107 	/* 1 reserved, overlaps with (CTL_VFS, VFS_NUMMNTOPS) */
108 	VT_UFS,
109 	/* 2 - 5 */
110 	VT_NFS, VT_MFS, VT_MSDOSFS, VT_LFS,
111 	/* 6 - 10 */
112 	VT_LOFS, VT_FDESC, VT_PORTAL, VT_NULL, VT_UMAP,
113 	/* 11 - 15 */
114 	VT_KERNFS, VT_PROCFS, VT_AFS, VT_ISOFS, VT_MOCKFS,
115 	/* 16 - 20 */
116 	VT_HFS, VT_ZFS, VT_DEVFS, VT_WEBDAV, VT_UDF,
117 	/* 21 - 25 */
118 	VT_AFP, VT_CDDA, VT_CIFS, VT_OTHER, VT_APFS,
119 	/* 26 - 27*/
120 	VT_LOCKERFS, VT_BINDFS,
121 };
122 
123 #define HAVE_VT_LOCKERFS 1
124 
125 /*
126  * flags for VNOP_BLOCKMAP
127  */
128 #define VNODE_READ      0x01
129 #define VNODE_WRITE     0x02
130 #define VNODE_BLOCKMAP_NO_TRACK 0x04 // APFS Fusion: Do not track this request
131 #define VNODE_CLUSTER_VERIFY 0x08 // Verification will be performed in the cluster layer
132 
133 
134 /* flags for VNOP_ALLOCATE */
135 #define PREALLOCATE             0x00000001      /* preallocate allocation blocks */
136 #define ALLOCATECONTIG  0x00000002      /* allocate contigious space */
137 #define ALLOCATEALL             0x00000004      /* allocate all requested space */
138 /* or no space at all */
139 #define ALLOCATEPERSIST         0x00000008      /* do not deallocate allocated but unfilled blocks at close(2) */
140 #define ALLOCATEFROMPEOF        0x00000010      /* allocate from the physical eof */
141 #define ALLOCATEFROMVOL         0x00000020      /* allocate from the volume offset */
142 
143 /*
144  * Token indicating no attribute value yet assigned. some user source uses this
145  */
146 #define VNOVAL  (-1)
147 
148 
149 #ifdef KERNEL
150 
151 /*
152  * Flags for ioflag.
153  */
154 #define IO_UNIT         0x0001          /* do I/O as atomic unit */
155 #define IO_APPEND       0x0002          /* append write to end */
156 #define IO_SYNC         0x0004          /* do I/O synchronously */
157 #define IO_NODELOCKED   0x0008          /* underlying node already locked */
158 #define IO_NDELAY       0x0010          /* FNDELAY flag set in file table */
159 #define IO_NOZEROFILL   0x0020          /* F_SETSIZE fcntl uses to prevent zero filling */
160 #ifdef XNU_KERNEL_PRIVATE
161 #define IO_REVOKE       IO_NOZEROFILL   /* revoked close for tty, will Not be used in conjunction */
162 #endif /* XNU_KERNEL_PRIVATE */
163 #define IO_TAILZEROFILL 0x0040          /* zero fills at the tail of write */
164 #define IO_HEADZEROFILL 0x0080          /* zero fills at the head of write */
165 #define IO_NOZEROVALID  0x0100          /* do not zero fill if valid page */
166 #define IO_NOZERODIRTY  0x0200          /* do not zero fill if page is dirty */
167 #define IO_CLOSE        0x0400          /* I/O issued from close path */
168 #define IO_NOCACHE      0x0800          /* same effect as VNOCACHE_DATA, but only for this 1 I/O */
169 #define IO_RAOFF        0x1000          /* same effect as VRAOFF, but only for this 1 I/O */
170 #define IO_DEFWRITE     0x2000          /* defer write if vfs.defwrite is set */
171 #define IO_PASSIVE      0x4000          /* this I/O is marked as background I/O so it won't throttle Throttleable I/O */
172 #define IO_BACKGROUND IO_PASSIVE /* used for backward compatibility.  to be removed after IO_BACKGROUND is no longer
173 	                          * used by DiskImages in-kernel mode */
174 #define IO_NOAUTH       0x8000          /* No authorization checks. */
175 #define IO_NODIRECT     0x10000         /* don't use direct synchronous writes if IO_NOCACHE is specified */
176 #define IO_ENCRYPTED    0x20000         /* Retrieve encrypted blocks from the filesystem */
177 #define IO_RETURN_ON_THROTTLE   0x40000
178 #define IO_SINGLE_WRITER        0x80000
179 #define IO_SYSCALL_DISPATCH             0x100000        /* I/O was originated from a file table syscall */
180 #define IO_SWAP_DISPATCH                0x200000        /* I/O was originated from the swap layer */
181 #define IO_SKIP_ENCRYPTION              0x400000        /* Skips en(de)cryption on the IO. Must be initiated from kernel */
182 #define IO_EVTONLY                      0x800000        /* the i/o is being done on an fd that's marked O_EVTONLY */
183 #define IO_NOCACHE_SYSSPACE             0x1000000       /* same as IO_NOCACHE but also for UIO_SYSSPACE */
184 #define IO_NOCACHE_SWRITE               0x2000000       /* same as IO_NOCACHE but also lossens retrictions for nocache writes */
185 
186 /*
187  * Component Name: this structure describes the pathname
188  * information that is passed through the VNOP interface.
189  */
190 struct componentname {
191 	/*
192 	 * Arguments to lookup.
193 	 */
194 	uint32_t        cn_nameiop;     /* lookup operation */
195 	uint32_t        cn_flags;       /* flags (see below) */
196 #ifdef BSD_KERNEL_PRIVATE
197 	vfs_context_t   cn_context;
198 	struct nameidata *cn_ndp;       /* pointer back to nameidata */
199 
200 /* XXX use of these defines are deprecated */
201 #define cn_proc         (cn_context->vc_proc + 0)       /* non-lvalue */
202 #define cn_cred         (cn_context->vc_ucred + 0)      /* non-lvalue */
203 
204 #else
205 	void * cn_reserved1;    /* use vfs_context_t */
206 	void * cn_reserved2;    /* use vfs_context_t */
207 #endif
208 	/*
209 	 * Shared between lookup and commit routines.
210 	 */
211 	char    *cn_pnbuf;      /* pathname buffer */
212 	int     cn_pnlen;       /* length of allocated buffer */
213 	char    *cn_nameptr;    /* pointer to looked up name */
214 	int     cn_namelen;     /* length of looked up component */
215 	uint32_t        cn_hash;        /* hash value of looked up name */
216 	uint32_t        cn_consume;     /* chars to consume in lookup() */
217 };
218 
219 /*
220  * component name operations (for VNOP_LOOKUP)
221  */
222 #define LOOKUP          0       /* perform name lookup only */
223 #define CREATE          1       /* setup for file creation */
224 #define DELETE          2       /* setup for file deletion */
225 #define RENAME          3       /* setup for file renaming */
226 #define OPMASK          3       /* mask for operation */
227 
228 /*
229  * component name operational modifier flags
230  */
231 #define FOLLOW          0x00000040 /* follow symbolic links */
232 
233 /*
234  * component name parameter descriptors.
235  */
236 #define ISDOTDOT        0x00002000 /* current component name is .. */
237 #define MAKEENTRY       0x00004000 /* entry is to be added to name cache */
238 #define ISLASTCN        0x00008000 /* this is last component of pathname */
239 
240 /* The following structure specifies a vnode for creation */
241 struct vnode_fsparam {
242 	struct mount * vnfs_mp;         /* mount point to which this vnode_t is part of */
243 	enum vtype      vnfs_vtype;             /* vnode type */
244 	const char * vnfs_str;          /* File system Debug aid */
245 	struct vnode * vnfs_dvp;                        /* The parent vnode */
246 	void * vnfs_fsnode;                     /* inode */
247 	int(**vnfs_vops)(void *);               /* vnode dispatch table */
248 	int vnfs_markroot;                      /* is this a root vnode in FS (not a system wide one) */
249 	int vnfs_marksystem;            /* is  a system vnode */
250 	dev_t vnfs_rdev;                        /* dev_t  for block or char vnodes */
251 	off_t vnfs_filesize;            /* that way no need for getattr in UBC */
252 	struct componentname * vnfs_cnp; /* component name to add to namecache */
253 	uint32_t vnfs_flags;            /* flags */
254 };
255 
256 #define VNFS_NOCACHE    0x01    /* do not add to name cache at this time */
257 #define VNFS_CANTCACHE  0x02    /* never add this instance to the name cache */
258 #define VNFS_ADDFSREF   0x04    /* take fs (named) reference */
259 
260 #define VNCREATE_FLAVOR 0
261 #define VCREATESIZE sizeof(struct vnode_fsparam)
262 #ifdef KERNEL_PRIVATE
263 /*
264  * For use with SPI to create trigger vnodes.
265  */
266 struct vnode_trigger_param;
267 #define VNCREATE_TRIGGER        (('T' << 8) + ('V'))
268 #define VNCREATE_TRIGGER_SIZE   sizeof(struct vnode_trigger_param)
269 #endif /* KERNEL_PRIVATE */
270 
271 
272 #ifdef KERNEL_PRIVATE
273 /*
274  * Resolver callback SPI for trigger vnodes
275  *
276  * Only available from kernels built with CONFIG_TRIGGERS option
277  */
278 
279 /*!
280  *  @enum Pathname Lookup Operations
281  *  @abstract Constants defining pathname operations (passed to resolver callbacks)
282  */
283 enum path_operation     {
284 	OP_LOOKUP,
285 	OP_MOUNT,
286 	OP_UNMOUNT,
287 	OP_STATFS,
288 	OP_OPEN,
289 	OP_LINK,
290 	OP_UNLINK,
291 	OP_RENAME,
292 	OP_CHDIR,
293 	OP_CHROOT,
294 	OP_MKNOD,
295 	OP_MKFIFO,
296 	OP_SYMLINK,
297 	OP_ACCESS,
298 	OP_PATHCONF,
299 	OP_READLINK,
300 	OP_GETATTR,
301 	OP_SETATTR,
302 	OP_TRUNCATE,
303 	OP_COPYFILE,
304 	OP_MKDIR,
305 	OP_RMDIR,
306 	OP_REVOKE,
307 	OP_EXCHANGEDATA,
308 	OP_SEARCHFS,
309 	OP_FSCTL,
310 	OP_GETXATTR,
311 	OP_SETXATTR,
312 	OP_REMOVEXATTR,
313 	OP_LISTXATTR,
314 	OP_MAXOP        /* anything beyond previous entry is invalid */
315 };
316 
317 /*!
318  *  @enum resolver status
319  *  @abstract Constants defining resolver status
320  *  @constant RESOLVER_RESOLVED  the resolver has finished (typically means a successful mount)
321  *  @constant RESOLVER_NOCHANGE  the resolver status didn't change
322  *  @constant RESOLVER_UNRESOLVED  the resolver has finished (typically means a successful unmount)
323  *  @constant RESOLVER_ERROR  the resolver encountered an error (errno passed in aux value)
324  *  @constant RESOLVER_STOP  a request to destroy trigger XXX do we need this???
325  */
326 enum resolver_status {
327 	RESOLVER_RESOLVED,
328 	RESOLVER_NOCHANGE,
329 	RESOLVER_UNRESOLVED,
330 	RESOLVER_ERROR,
331 	RESOLVER_STOP
332 };
333 
334 typedef uint64_t resolver_result_t;
335 
336 /*
337  * Compound resolver result
338  *
339  * The trigger vnode callbacks use a compound result value. In addition
340  * to the resolver status, it contains a sequence number and an auxiliary
341  * value.
342  *
343  * The sequence value is used by VFS to sequence-stamp trigger vnode
344  * state transitions. It is expected to be incremented each time a
345  * resolver changes state (ie resolved or unresolved). A result
346  * containing a stale sequence (older than a trigger vnode's current
347  * value) will be ignored by VFS.
348  *
349  * The auxiliary value is currently only used to deliver the errno
350  * value for RESOLVER_ERROR status conditions. When a RESOLVER_ERROR
351  * occurs, VFS will propagate this error back to the syscall that
352  * encountered the trigger vnode.
353  */
354 extern resolver_result_t vfs_resolver_result(uint32_t seq, enum resolver_status stat, int aux);
355 
356 /*
357  * Extract values from a compound resolver result
358  */
359 extern enum resolver_status vfs_resolver_status(resolver_result_t);
360 extern uint32_t vfs_resolver_sequence(resolver_result_t);
361 extern int vfs_resolver_auxiliary(resolver_result_t);
362 
363 
364 /*!
365  *  @typedef trigger_vnode_resolve_callback_t
366  *  @abstract function prototype for a trigger vnode resolve callback
367  *  @discussion This function is associated with a trigger vnode during a vnode create.  It is
368  *  typically called when a lookup operation occurs for a trigger vnode
369  *  @param vp The trigger vnode which needs resolving
370  *  @param cnp Various data about lookup, e.g. filename and state flags
371  *  @param pop The pathname operation that initiated the lookup (see enum path_operation).
372  *  @param flags resolve flags
373  *  @param data Arbitrary data supplied by vnode trigger creator
374  *  @param ctx Context for authentication.
375  *  @return RESOLVER_RESOLVED, RESOLVER_NOCHANGE, RESOLVER_UNRESOLVED or RESOLVER_ERROR
376  */
377 typedef resolver_result_t (* trigger_vnode_resolve_callback_t)(
378 	vnode_t                         vp,
379 	const struct componentname *    cnp,
380 	enum path_operation             pop,
381 	int                             flags,
382 	void *                          data,
383 	vfs_context_t                   ctx);
384 
385 /*!
386  *  @typedef trigger_vnode_unresolve_callback_t
387  *  @abstract function prototype for a trigger vnode unresolve callback
388  *  @discussion This function is associated with a trigger vnode during a vnode create.  It is
389  *  called to unresolve a trigger vnode (typically this means unmount).
390  *  @param vp The trigger vnode which needs unresolving
391  *  @param flags Unmount flags
392  *  @param data Arbitrary data supplied by vnode trigger creator
393  *  @param ctx Context for authentication.
394  *  @return RESOLVER_NOCHANGE, RESOLVER_UNRESOLVED or RESOLVER_ERROR
395  */
396 typedef resolver_result_t (* trigger_vnode_unresolve_callback_t)(
397 	vnode_t         vp,
398 	int             flags,
399 	void *          data,
400 	vfs_context_t   ctx);
401 
402 /*!
403  *  @typedef trigger_vnode_rearm_callback_t
404  *  @abstract function prototype for a trigger vnode rearm callback
405  *  @discussion This function is associated with a trigger vnode during a vnode create.  It is
406  *  called to verify a rearm from VFS (i.e. should VFS rearm the trigger?).
407  *  @param vp The trigger vnode which needs rearming
408  *  @param flags rearm flags
409  *  @param data Arbitrary data supplied by vnode trigger creator
410  *  @param ctx Context for authentication.
411  *  @return RESOLVER_NOCHANGE or RESOLVER_ERROR
412  */
413 typedef resolver_result_t (* trigger_vnode_rearm_callback_t)(
414 	vnode_t         vp,
415 	int             flags,
416 	void *          data,
417 	vfs_context_t   ctx);
418 
419 /*!
420  *  @typedef trigger_vnode_reclaim_callback_t
421  *  @abstract function prototype for a trigger vnode reclaim callback
422  *  @discussion This function is associated with a trigger vnode during a vnode create.  It is
423  *  called to deallocate private callback argument data
424  *  @param vp The trigger vnode associated with the data
425  *  @param data The arbitrary data supplied by vnode trigger creator
426  */
427 typedef void (* trigger_vnode_reclaim_callback_t)(
428 	vnode_t         vp,
429 	void *          data);
430 
431 /*!
432  *  @function vnode_trigger_update
433  *  @abstract Update a trigger vnode's state.
434  *  @discussion This allows a resolver to notify VFS of a state change in a trigger vnode.
435  *  @param vp The trigger vnode whose information to update.
436  *  @param result A compound resolver result value
437  *  @return EINVAL if result value is invalid or vp isn't a trigger vnode
438  */
439 extern int vnode_trigger_update(vnode_t vp, resolver_result_t result);
440 
441 struct vnode_trigger_info {
442 	trigger_vnode_resolve_callback_t        vti_resolve_func;
443 	trigger_vnode_unresolve_callback_t      vti_unresolve_func;
444 	trigger_vnode_rearm_callback_t          vti_rearm_func;
445 	trigger_vnode_reclaim_callback_t        vti_reclaim_func;
446 	void *                                  vti_data;   /* auxiliary data (optional) */
447 	uint32_t                                vti_flags;  /* optional flags (see below) */
448 };
449 
450 /*
451  * SPI for creating a trigger vnode
452  *
453  * Uses the VNCREATE_TRIGGER flavor with existing vnode_create() KPI
454  *
455  * Only one resolver per vnode.
456  *
457  * ERRORS (in addition to vnode_create errors):
458  *	EINVAL (invalid resolver info, like invalid flags)
459  *	ENOTDIR (only directories can have a resolver)
460  *	EPERM (vnode cannot be a trigger - eg root dir of a file system)
461  *	ENOMEM
462  */
463 struct vnode_trigger_param {
464 	struct vnode_fsparam                    vnt_params; /* same as for VNCREATE_FLAVOR */
465 	trigger_vnode_resolve_callback_t        vnt_resolve_func;
466 	trigger_vnode_unresolve_callback_t      vnt_unresolve_func;
467 	trigger_vnode_rearm_callback_t          vnt_rearm_func;
468 	trigger_vnode_reclaim_callback_t        vnt_reclaim_func;
469 	void *                                  vnt_data;   /* auxiliary data (optional) */
470 	uint32_t                                vnt_flags;  /* optional flags (see below) */
471 };
472 
473 /*
474  * vnode trigger flags (vnt_flags)
475  *
476  * VNT_AUTO_REARM:
477  * On unmounts of a trigger mount, automatically re-arm the trigger.
478  *
479  * VNT_NO_DIRECT_MOUNT:
480  * A trigger vnode instance that doesn't directly trigger a mount,
481  * instead it triggers the mounting of sub-trigger nodes.
482  *
483  * VNT_KERN_RESOLVE:
484  * A trigger vnode where all parameters have been set by the kernel,
485  * such as NFS mirror mounts.
486  */
487 #define VNT_AUTO_REARM          (1 << 0)
488 #define VNT_NO_DIRECT_MOUNT     (1 << 1)
489 #define VNT_KERN_RESOLVE        (1 << 2)
490 #define VNT_VALID_MASK          (VNT_AUTO_REARM | VNT_NO_DIRECT_MOUNT | \
491 	                         VNT_KERN_RESOLVE)
492 
493 #endif /* KERNEL_PRIVATE */
494 
495 
496 /*
497  * Vnode attributes, new-style.
498  *
499  * The vnode_attr structure is used to transact attribute changes and queries
500  * with the filesystem.
501  *
502  * Note that this structure may be extended, but existing fields must not move.
503  */
504 
505 #define VATTR_INIT(v)                   do {(v)->va_supported = (v)->va_active = 0ll; (v)->va_vaflags = 0; } while(0)
506 #define VATTR_SET_ACTIVE(v, a)          ((v)->va_active |= VNODE_ATTR_ ## a)
507 #define VATTR_SET_SUPPORTED(v, a)       ((v)->va_supported |= VNODE_ATTR_ ## a)
508 #define VATTR_IS_SUPPORTED(v, a)        ((v)->va_supported & VNODE_ATTR_ ## a)
509 #define VATTR_CLEAR_ACTIVE(v, a)        ((v)->va_active &= ~VNODE_ATTR_ ## a)
510 #define VATTR_CLEAR_SUPPORTED(v, a)     ((v)->va_supported &= ~VNODE_ATTR_ ## a)
511 #define VATTR_CLEAR_SUPPORTED_ALL(v)    ((v)->va_supported = 0)
512 #define VATTR_IS_ACTIVE(v, a)           ((v)->va_active & VNODE_ATTR_ ## a)
513 #define VATTR_ALL_SUPPORTED(v)          (((v)->va_active & (v)->va_supported) == (v)->va_active)
514 #define VATTR_INACTIVE_SUPPORTED(v)     do {(v)->va_active &= ~(v)->va_supported; (v)->va_supported = 0;} while(0)
515 #define VATTR_SET(v, a, x)              do { (v)-> a = (x); VATTR_SET_ACTIVE(v, a);} while(0)
516 #define VATTR_WANTED(v, a)              VATTR_SET_ACTIVE(v, a)
517 #define VATTR_RETURN(v, a, x)           do { (v)-> a = (x); VATTR_SET_SUPPORTED(v, a);} while(0)
518 #define VATTR_NOT_RETURNED(v, a)        (VATTR_IS_ACTIVE(v, a) && !VATTR_IS_SUPPORTED(v, a))
519 
520 /*
521  * Two macros to simplify conditional checking in kernel code.
522  */
523 #define VATTR_IS(v, a, x)               (VATTR_IS_SUPPORTED(v, a) && (v)-> a == (x))
524 #define VATTR_IS_NOT(v, a, x)           (VATTR_IS_SUPPORTED(v, a) && (v)-> a != (x))
525 
526 #define VNODE_ATTR_va_rdev              (1LL<< 0)       /* 00000001 */
527 #define VNODE_ATTR_va_nlink             (1LL<< 1)       /* 00000002 */
528 #define VNODE_ATTR_va_total_size        (1LL<< 2)       /* 00000004 */
529 #define VNODE_ATTR_va_total_alloc       (1LL<< 3)       /* 00000008 */
530 #define VNODE_ATTR_va_data_size         (1LL<< 4)       /* 00000010 */
531 #define VNODE_ATTR_va_data_alloc        (1LL<< 5)       /* 00000020 */
532 #define VNODE_ATTR_va_iosize            (1LL<< 6)       /* 00000040 */
533 #define VNODE_ATTR_va_uid               (1LL<< 7)       /* 00000080 */
534 #define VNODE_ATTR_va_gid               (1LL<< 8)       /* 00000100 */
535 #define VNODE_ATTR_va_mode              (1LL<< 9)       /* 00000200 */
536 #define VNODE_ATTR_va_flags             (1LL<<10)       /* 00000400 */
537 #define VNODE_ATTR_va_acl               (1LL<<11)       /* 00000800 */
538 #define VNODE_ATTR_va_create_time       (1LL<<12)       /* 00001000 */
539 #define VNODE_ATTR_va_access_time       (1LL<<13)       /* 00002000 */
540 #define VNODE_ATTR_va_modify_time       (1LL<<14)       /* 00004000 */
541 #define VNODE_ATTR_va_change_time       (1LL<<15)       /* 00008000 */
542 #define VNODE_ATTR_va_backup_time       (1LL<<16)       /* 00010000 */
543 #define VNODE_ATTR_va_fileid            (1LL<<17)       /* 00020000 */
544 #define VNODE_ATTR_va_linkid            (1LL<<18)       /* 00040000 */
545 #define VNODE_ATTR_va_parentid          (1LL<<19)       /* 00080000 */
546 #define VNODE_ATTR_va_fsid              (1LL<<20)       /* 00100000 */
547 #define VNODE_ATTR_va_filerev           (1LL<<21)       /* 00200000 */
548 #define VNODE_ATTR_va_gen               (1LL<<22)       /* 00400000 */
549 #define VNODE_ATTR_va_encoding          (1LL<<23)       /* 00800000 */
550 #define VNODE_ATTR_va_type              (1LL<<24)       /* 01000000 */
551 #define VNODE_ATTR_va_name              (1LL<<25)       /* 02000000 */
552 #define VNODE_ATTR_va_uuuid             (1LL<<26)       /* 04000000 */
553 #define VNODE_ATTR_va_guuid             (1LL<<27)       /* 08000000 */
554 #define VNODE_ATTR_va_nchildren         (1LL<<28)       /* 10000000 */
555 #define VNODE_ATTR_va_dirlinkcount      (1LL<<29)       /* 20000000 */
556 #define VNODE_ATTR_va_addedtime         (1LL<<30)       /* 40000000 */
557 #define VNODE_ATTR_va_dataprotect_class (1LL<<31)       /* 80000000 */
558 #define VNODE_ATTR_va_dataprotect_flags (1LL<<32)       /* 100000000 */
559 #define VNODE_ATTR_va_document_id       (1LL<<33)       /* 200000000 */
560 #define VNODE_ATTR_va_devid             (1LL<<34)       /* 400000000 */
561 #define VNODE_ATTR_va_objtype           (1LL<<35)       /* 800000000 */
562 #define VNODE_ATTR_va_objtag            (1LL<<36)       /* 1000000000 */
563 #define VNODE_ATTR_va_user_access       (1LL<<37)       /* 2000000000 */
564 #define VNODE_ATTR_va_finderinfo        (1LL<<38)       /* 4000000000 */
565 #define VNODE_ATTR_va_rsrc_length       (1LL<<39)       /* 8000000000 */
566 #define VNODE_ATTR_va_rsrc_alloc        (1LL<<40)       /* 10000000000 */
567 #define VNODE_ATTR_va_fsid64            (1LL<<41)       /* 20000000000 */
568 #define VNODE_ATTR_va_write_gencount    (1LL<<42)       /* 40000000000 */
569 #define VNODE_ATTR_va_private_size      (1LL<<43)       /* 80000000000 */
570 #define VNODE_ATTR_va_clone_id          (1LL<<44)       /* 100000000000 */
571 #define VNODE_ATTR_va_extflags          (1LL<<45)       /* 200000000000 */
572 #define VNODE_ATTR_va_recursive_gencount (1LL<<46)      /* 400000000000 */
573 #define VNODE_ATTR_va_attribution_tag    (1LL<<47)      /* 800000000000 */
574 #define VNODE_ATTR_va_clone_refcnt       (1LL<<48)      /* 1000000000000 */
575 
576 #define VNODE_ATTR_BIT(n)       (VNODE_ATTR_ ## n)
577 
578 /*
579  * ALL of the attributes.
580  */
581 #define VNODE_ATTR_ALL          (VNODE_ATTR_BIT(va_rdev) |              \
582 	                        VNODE_ATTR_BIT(va_nlink) |              \
583 	                        VNODE_ATTR_BIT(va_total_size) |         \
584 	                        VNODE_ATTR_BIT(va_total_alloc) |        \
585 	                        VNODE_ATTR_BIT(va_data_size) |          \
586 	                        VNODE_ATTR_BIT(va_data_alloc) |         \
587 	                        VNODE_ATTR_BIT(va_iosize) |             \
588 	                        VNODE_ATTR_BIT(va_uid) |                \
589 	                        VNODE_ATTR_BIT(va_gid) |                \
590 	                        VNODE_ATTR_BIT(va_mode) |               \
591 	                        VNODE_ATTR_BIT(va_flags) |              \
592 	                        VNODE_ATTR_BIT(va_acl) |                \
593 	                        VNODE_ATTR_BIT(va_create_time) |        \
594 	                        VNODE_ATTR_BIT(va_access_time) |        \
595 	                        VNODE_ATTR_BIT(va_modify_time) |        \
596 	                        VNODE_ATTR_BIT(va_change_time) |        \
597 	                        VNODE_ATTR_BIT(va_backup_time) |        \
598 	                        VNODE_ATTR_BIT(va_fileid) |             \
599 	                        VNODE_ATTR_BIT(va_linkid) |             \
600 	                        VNODE_ATTR_BIT(va_parentid) |           \
601 	                        VNODE_ATTR_BIT(va_fsid) |               \
602 	                        VNODE_ATTR_BIT(va_filerev) |            \
603 	                        VNODE_ATTR_BIT(va_gen) |                \
604 	                        VNODE_ATTR_BIT(va_encoding) |           \
605 	                        VNODE_ATTR_BIT(va_type) |               \
606 	                        VNODE_ATTR_BIT(va_name) |               \
607 	                        VNODE_ATTR_BIT(va_uuuid) |              \
608 	                        VNODE_ATTR_BIT(va_guuid) |              \
609 	                        VNODE_ATTR_BIT(va_nchildren) |          \
610 	                        VNODE_ATTR_BIT(va_dirlinkcount) |       \
611 	                        VNODE_ATTR_BIT(va_addedtime) |          \
612 	                        VNODE_ATTR_BIT(va_dataprotect_class) |  \
613 	                        VNODE_ATTR_BIT(va_dataprotect_flags) |  \
614 	                        VNODE_ATTR_BIT(va_document_id) |        \
615 	                        VNODE_ATTR_BIT(va_devid) |              \
616 	                        VNODE_ATTR_BIT(va_objtype) |            \
617 	                        VNODE_ATTR_BIT(va_objtag) |             \
618 	                        VNODE_ATTR_BIT(va_user_access) |        \
619 	                        VNODE_ATTR_BIT(va_finderinfo) |         \
620 	                        VNODE_ATTR_BIT(va_rsrc_length) |        \
621 	                        VNODE_ATTR_BIT(va_rsrc_alloc) |         \
622 	                        VNODE_ATTR_BIT(va_fsid64) |             \
623 	                        VNODE_ATTR_BIT(va_write_gencount) |     \
624 	                        VNODE_ATTR_BIT(va_private_size) |       \
625 	                        VNODE_ATTR_BIT(va_clone_id) |           \
626 	                        VNODE_ATTR_BIT(va_extflags) |           \
627 	                        VNODE_ATTR_BIT(va_recursive_gencount) | \
628 	                        VNODE_ATTR_BIT(va_attribution_tag) |    \
629 	                        VNODE_ATTR_BIT(va_clone_refcnt))
630 
631 
632 /*
633  * Read-only attributes.
634  */
635 #define VNODE_ATTR_RDONLY       (VNODE_ATTR_BIT(va_rdev) |              \
636 	                        VNODE_ATTR_BIT(va_nlink) |              \
637 	                        VNODE_ATTR_BIT(va_total_size) |         \
638 	                        VNODE_ATTR_BIT(va_total_alloc) |        \
639 	                        VNODE_ATTR_BIT(va_data_alloc) |         \
640 	                        VNODE_ATTR_BIT(va_iosize) |             \
641 	                        VNODE_ATTR_BIT(va_fileid) |             \
642 	                        VNODE_ATTR_BIT(va_linkid) |             \
643 	                        VNODE_ATTR_BIT(va_parentid) |           \
644 	                        VNODE_ATTR_BIT(va_fsid) |               \
645 	                        VNODE_ATTR_BIT(va_filerev) |            \
646 	                        VNODE_ATTR_BIT(va_gen) |                \
647 	                        VNODE_ATTR_BIT(va_name) |               \
648 	                        VNODE_ATTR_BIT(va_type) |               \
649 	                        VNODE_ATTR_BIT(va_nchildren) |          \
650 	                        VNODE_ATTR_BIT(va_dirlinkcount) |       \
651 	                        VNODE_ATTR_BIT(va_devid) |              \
652 	                        VNODE_ATTR_BIT(va_objtype) |            \
653 	                        VNODE_ATTR_BIT(va_objtag) |             \
654 	                        VNODE_ATTR_BIT(va_user_access) |        \
655 	                        VNODE_ATTR_BIT(va_finderinfo) |         \
656 	                        VNODE_ATTR_BIT(va_rsrc_length) |        \
657 	                        VNODE_ATTR_BIT(va_rsrc_alloc) |         \
658 	                        VNODE_ATTR_BIT(va_fsid64) |             \
659 	                        VNODE_ATTR_BIT(va_write_gencount) |     \
660 	                        VNODE_ATTR_BIT(va_private_size) |       \
661 	                        VNODE_ATTR_BIT(va_clone_id) |           \
662 	                        VNODE_ATTR_BIT(va_extflags) |           \
663 	                        VNODE_ATTR_BIT(va_recursive_gencount) | \
664 	                        VNODE_ATTR_BIT(va_attribution_tag) |    \
665 	                        VNODE_ATTR_BIT(va_clone_refcnt))
666 
667 /*
668  * Attributes that can be applied to a new file object.
669  */
670 #define VNODE_ATTR_NEWOBJ       (VNODE_ATTR_BIT(va_rdev) |              \
671 	                        VNODE_ATTR_BIT(va_uid)	|               \
672 	                        VNODE_ATTR_BIT(va_gid) |                \
673 	                        VNODE_ATTR_BIT(va_mode) |               \
674 	                        VNODE_ATTR_BIT(va_flags) |              \
675 	                        VNODE_ATTR_BIT(va_acl) |                \
676 	                        VNODE_ATTR_BIT(va_create_time) |        \
677 	                        VNODE_ATTR_BIT(va_modify_time) |        \
678 	                        VNODE_ATTR_BIT(va_change_time) |        \
679 	                        VNODE_ATTR_BIT(va_encoding) |           \
680 	                        VNODE_ATTR_BIT(va_type) |               \
681 	                        VNODE_ATTR_BIT(va_uuuid) |              \
682 	                        VNODE_ATTR_BIT(va_guuid) |              \
683 	                        VNODE_ATTR_BIT(va_dataprotect_class) |  \
684 	                        VNODE_ATTR_BIT(va_dataprotect_flags) |  \
685 	                        VNODE_ATTR_BIT(va_document_id))
686 
687 #include <sys/_types/_fsid_t.h>
688 
689 struct vnode_attr {
690 	/* bitfields */
691 	uint64_t        va_supported;
692 	uint64_t        va_active;
693 
694 	/*
695 	 * Control flags.  The low 16 bits are reserved for the
696 	 * ioflags being passed for truncation operations.
697 	 */
698 	int             va_vaflags;
699 
700 	/* traditional stat(2) parameter fields */
701 	dev_t           va_rdev;        /* device id (device nodes only) */
702 	uint64_t        va_nlink;       /* number of references to this file */
703 	uint64_t        va_total_size;  /* size in bytes of all forks */
704 	uint64_t        va_total_alloc; /* disk space used by all forks */
705 	uint64_t        va_data_size;   /* size in bytes of the fork managed by current vnode */
706 	uint64_t        va_data_alloc;  /* disk space used by the fork managed by current vnode */
707 	uint32_t        va_iosize;      /* optimal I/O blocksize */
708 
709 	/* file security information */
710 	uid_t           va_uid;         /* owner UID */
711 	gid_t           va_gid;         /* owner GID */
712 	mode_t          va_mode;        /* posix permissions */
713 	uint32_t        va_flags;       /* file flags */
714 	struct kauth_acl *va_acl;       /* access control list */
715 
716 	/* timestamps */
717 	struct timespec va_create_time; /* time of creation */
718 	struct timespec va_access_time; /* time of last access */
719 	struct timespec va_modify_time; /* time of last data modification */
720 	struct timespec va_change_time; /* time of last metadata change */
721 	struct timespec va_backup_time; /* time of last backup */
722 
723 	/* file parameters */
724 	uint64_t        va_fileid;      /* file unique ID in filesystem */
725 	uint64_t        va_linkid;      /* file link unique ID */
726 	uint64_t        va_parentid;    /* parent ID */
727 	uint32_t        va_fsid;        /* filesystem ID */
728 	uint64_t        va_filerev;     /* file revision counter */	/* XXX */
729 	uint32_t        va_gen;         /* file generation count */	/* XXX - relationship of
730 	                                 * these two? */
731 	/* misc parameters */
732 	uint32_t        va_encoding;    /* filename encoding script */
733 
734 	enum vtype      va_type;        /* file type */
735 	char *          va_name;        /* Name for ATTR_CMN_NAME; MAXPATHLEN bytes */
736 	guid_t          va_uuuid;       /* file owner UUID */
737 	guid_t          va_guuid;       /* file group UUID */
738 
739 	/* Meaningful for directories only */
740 	uint64_t        va_nchildren;     /* Number of items in a directory */
741 	uint64_t        va_dirlinkcount;  /* Real references to dir (i.e. excluding "." and ".." refs) */
742 
743 #ifdef BSD_KERNEL_PRIVATE
744 	struct kauth_acl *va_base_acl;
745 #else
746 	void *          va_reserved1;
747 #endif /* BSD_KERNEL_PRIVATE */
748 	struct timespec va_addedtime;   /* timestamp when item was added to parent directory */
749 
750 	/* Data Protection fields */
751 	uint32_t va_dataprotect_class;  /* class specified for this file if it didn't exist */
752 	uint32_t va_dataprotect_flags;  /* flags from NP open(2) to the filesystem */
753 
754 	/* Document revision tracking */
755 	uint32_t va_document_id;
756 
757 	/* Fields for Bulk args */
758 	uint32_t        va_devid;       /* devid of filesystem */
759 	uint32_t        va_objtype;     /* type of object */
760 	uint32_t        va_objtag;      /* vnode tag of filesystem */
761 	uint32_t        va_user_access; /* access for user */
762 	uint8_t         va_finderinfo[32];      /* Finder Info */
763 	uint64_t        va_rsrc_length; /* Resource Fork length */
764 	uint64_t        va_rsrc_alloc;  /* Resource Fork allocation size */
765 	fsid_t          va_fsid64;      /* fsid, of the correct type  */
766 
767 	uint32_t va_write_gencount;     /* counter that increments each time the file changes */
768 
769 	uint64_t va_private_size; /* If the file were deleted, how many bytes would be freed immediately */
770 	uint64_t va_clone_id;     /* If a file is cloned this is a unique id shared by all "perfect" clones */
771 	uint64_t va_extflags;     /* extended file/directory flags */
772 	uint64_t va_recursive_gencount; /* for dir-stats enabled directories */
773 	uint64_t va_attribution_tag;    /* a 64 bit hash of the bundle name associated with this file */
774 	uint32_t va_clone_refcnt;       /* the number of "perfect" clones sharing the same clone_id */
775 
776 	/* add new fields here only */
777 };
778 
779 #ifdef BSD_KERNEL_PRIVATE
780 /*
781  * Flags for va_dataprotect_flags
782  */
783 #define VA_DP_RAWENCRYPTED   0x0001
784 #define VA_DP_RAWUNENCRYPTED 0x0002
785 #define VA_DP_AUTHENTICATE   0x0004
786 
787 #endif
788 
789 /*
790  * Flags for va_vaflags.
791  */
792 #define VA_UTIMES_NULL          0x010000        /* utimes argument was NULL */
793 #define VA_EXCLUSIVE            0x020000        /* exclusive create request */
794 #define VA_NOINHERIT            0x040000        /* Don't inherit ACLs from parent */
795 #define VA_NOAUTH               0x080000
796 #define VA_64BITOBJIDS          0x100000        /* fileid/linkid/parentid are 64 bit */
797 #define VA_REALFSID             0x200000        /* Return real fsid */
798 #define VA_USEFSID              0x400000        /* Use fsid from filesystem  */
799 #define VA_FILESEC_ACL          0x800000        /* ACL is interior to filesec */
800 
801 /*
802  *  Modes.  Some values same as Ixxx entries from inode.h for now.
803  */
804 #define VSUID   0x800 /*04000*/	/* set user id on execution */
805 #define VSGID   0x400 /*02000*/	/* set group id on execution */
806 #define VSVTX   0x200 /*01000*/	/* save swapped text even after use */
807 #define VREAD   0x100 /*00400*/	/* read, write, execute permissions */
808 #define VWRITE  0x080 /*00200*/
809 #define VEXEC   0x040 /*00100*/
810 
811 /*
812  * Convert between vnode types and inode formats (since POSIX.1
813  * defines mode word of stat structure in terms of inode formats).
814  */
815 extern enum vtype       iftovt_tab[];
816 extern int              vttoif_tab[];
817 #define IFTOVT(mode)    (iftovt_tab[((mode) & S_IFMT) >> 12])
818 #define VTTOIF(indx)    (vttoif_tab[(int)(indx)])
819 #define MAKEIMODE(indx, mode)   (int)(VTTOIF(indx) | (mode))
820 
821 /*
822  * Flags to various vnode functions.
823  */
824 #define SKIPSYSTEM      0x0001          /* vflush: skip vnodes marked VSYSTEM */
825 #define FORCECLOSE      0x0002          /* vflush: force file closeure */
826 #define WRITECLOSE      0x0004          /* vflush: only close writeable files */
827 #define SKIPSWAP        0x0008          /* vflush: skip vnodes marked VSWAP */
828 #define SKIPROOT        0x0010          /* vflush: skip root vnodes marked VROOT */
829 
830 #define DOCLOSE         0x0008          /* vclean: close active files */
831 
832 #define V_SAVE          0x0001          /* vinvalbuf: sync file first */
833 #define V_SAVEMETA      0x0002          /* vinvalbuf: leave indirect blocks */
834 
835 #define REVOKEALL       0x0001          /* vnop_revoke: revoke all aliases */
836 
837 /* VNOP_REMOVE/unlink flags */
838 #define VNODE_REMOVE_NODELETEBUSY                       0x0001 /* Don't delete busy files (Carbon) */
839 #define VNODE_REMOVE_SKIP_NAMESPACE_EVENT       0x0002 /* Do not upcall to userland handlers */
840 #define VNODE_REMOVE_NO_AUDIT_PATH              0x0004 /* Do not audit the path */
841 #define VNODE_REMOVE_DATALESS_DIR               0x0008 /* Special handling for removing a dataless directory without materialization */
842 #ifdef BSD_KERNEL_PRIVATE
843 #define VNODE_REMOVE_NOFOLLOW_ANY               0x0010
844 #endif
845 #define VNODE_REMOVE_SYSTEM_DISCARDED           0x0020 /* Update speculative telemetry with SYSTEM_DISCARDED use state (Default USER_DISCARDED use state) */
846 
847 /* VNOP_READDIR flags: */
848 #define VNODE_READDIR_EXTENDED    0x0001   /* use extended directory entries */
849 #define VNODE_READDIR_REQSEEKOFF  0x0002   /* requires seek offset (cookies) */
850 #define VNODE_READDIR_SEEKOFF32   0x0004   /* seek offset values should fit in 32 bits */
851 #define VNODE_READDIR_NAMEMAX     0x0008   /* For extended readdir, try to limit names to NAME_MAX bytes */
852 
853 /* VNOP_CLONEFILE flags: */
854 #define VNODE_CLONEFILE_DEFAULT       0x0000
855 #define VNODE_CLONEFILE_NOOWNERCOPY   0x0001 /* Don't copy ownership information */
856 
857 
858 #define NULLVP  ((struct vnode *)NULL)
859 
860 #ifndef BSD_KERNEL_PRIVATE
861 struct vnodeop_desc;
862 #endif
863 
864 extern  int desiredvnodes;              /* number of vnodes desired */
865 
866 extern struct smr apfs_smr; /* SMR domain for apfs kext, equivalent to _vfs_smr */
867 
868 /*
869  * This structure is used to configure the new vnodeops vector.
870  */
871 struct vnodeopv_entry_desc {
872 	struct vnodeop_desc *opve_op;   /* which operation this is */
873 	int (*opve_impl)(void *);               /* code implementing this operation */
874 };
875 struct vnodeopv_desc {
876 	/* ptr to the ptr to the vector where op should go */
877 	int(***opv_desc_vector_p)(void *);
878 	const struct vnodeopv_entry_desc *opv_desc_ops;   /* null terminated list */
879 };
880 
881 /*!
882  *  @function vn_default_error
883  *  @abstract Default vnode operation to fill unsupported slots in vnode operation vectors.
884  *  @return ENOTSUP
885  */
886 int vn_default_error(void);
887 
888 /*
889  * A generic structure.
890  * This can be used by bypass routines to identify generic arguments.
891  */
892 struct vnop_generic_args {
893 	struct vnodeop_desc *a_desc;
894 	/* other random data follows, presumably */
895 };
896 
897 #include <sys/vnode_if.h>
898 
899 __BEGIN_DECLS
900 
901 /*!
902  *  @function vnode_create
903  *  @abstract Create and initialize a vnode.
904  *  @discussion Returns wth an iocount held on the vnode which must eventually be dropped with vnode_put().
905  *  @param flavor Should be VNCREATE_FLAVOR.
906  *  @param size  Size of the struct vnode_fsparam in "data".
907  *  @param data  Pointer to a struct vnode_fsparam containing initialization information.
908  *  @param vpp  Pointer to a vnode pointer, to be filled in with newly created vnode.
909  *  @return 0 for success, error code otherwise.
910  */
911 errno_t vnode_create(uint32_t flavor, uint32_t size, void  *data, vnode_t *vpp);
912 
913 #ifdef KERNEL_PRIVATE
914 
915 __options_decl(vnode_create_options_t, uint32_t, {
916 	VNODE_CREATE_DEFAULT = 0,
917 	VNODE_CREATE_EMPTY   = 1,
918 	VNODE_CREATE_NODEALLOC  = 2
919 });
920 
921 #define VNODE_CREATE_DEFAULT VNODE_CREATE_DEFAULT
922 
923 /*!
924  *  @function vnode_create_ext
925  *  @abstract Create and initialize a vnode.
926  *  @discussion Returns wth an iocount held on the vnode which must eventually be dropped with vnode_put().
927  *  @param flavor Should be VNCREATE_FLAVOR.
928  *  @param size  Size of the struct vnode_fsparam in "data".
929  *  @param data  Pointer to a struct vnode_fsparam containing initialization information.
930  *  @param vpp  Pointer to a vnode pointer, to be filled in with newly created vnode.
931  *  @param vc_options  options for vnode creation, by default a vnode that can be deallocated is created,
932  *  use VNODE_CREATE_NODEALLOC to override the default behavior.
933  *  @return 0 for success, error code otherwise.
934  */
935 errno_t vnode_create_ext(uint32_t flavor, uint32_t size, void  *data, vnode_t *vpp, vnode_create_options_t vc_options);
936 
937 /*
938  * vnode create options (vc_options)
939  *
940  * VNODE_CREATE_EMPTY:
941  * An "empty" vnode( i.e. a vnode not initialized with filesystem information) is returned
942  * This results in the flavor, size and data arguments to vnode_create_ext getting ignored.
943  *
944  * VNODE_CREATE_NODEALLOC:
945  * The filesystem does not support vnodes that can be deallocated. By default, vnodes
946  * that are created by using vnode_create_ext can be deallocated and the calling filesytem
947  * uses vnode_hold and vnode_drop approrpiately. This flag should be be used to override
948  * the default behavior.
949  *
950  */
951 
952 /*!
953  *  @function vnode_create_empty
954  *  @abstract Create an empty, uninitialized vnode.
955  *  @discussion Returns with an iocount held on the vnode which must eventually be
956  *  dropped with vnode_put(). The next operation performed on the vnode must be
957  *  vnode_initialize (or vnode_put if the vnode is not needed anymore).
958  *  This interface is provided as a mechanism to pre-flight obtaining a vnode for
959  *  certain filesystem operations which may need to get a vnode without filesystem
960  *  locks held. It is imperative that nothing be done with the vnode till the
961  *  succeeding vnode_initialize (or vnode_put as the case may be) call.
962  *  @param vpp  Pointer to a vnode pointer, to be filled in with newly created vnode.
963  *  @return 0 for success, error code otherwise.
964  */
965 errno_t vnode_create_empty(vnode_t *vpp);
966 
967 /*!
968  *  @function vnode_initialize
969  *  @abstract Initialize a vnode obtained by vnode_create_empty
970  *  @discussion Does not drop iocount held on the vnode which must eventually be
971  *  dropped with vnode_put().  In case of an error however, the vnode's iocount is
972  *  dropped and the vnode must not be referenced again by the caller.
973  *  @param flavor Should be VNCREATE_FLAVOR.
974  *  @param size  Size of the struct vnode_fsparam in "data".
975  *  @param data  Pointer to a struct vnode_fsparam containing initialization information.
976  *  @param vpp  Pointer to a vnode pointer, to be filled in with newly created vnode.
977  *  @return 0 for success, error code otherwise.
978  */
979 errno_t vnode_initialize(uint32_t flavor, uint32_t size, void *data, vnode_t *vpp);
980 #endif /* KERNEL_PRIVATE */
981 
982 /*!
983  *  @function vnode_addfsref
984  *  @abstract Mark a vnode as being stored in a filesystem hash.
985  *  @discussion Should only be called once on a vnode, and never if that vnode was created with VNFS_ADDFSREF.
986  *  There should be a corresponding call to vnode_removefsref() when the vnode is reclaimed; VFS assumes that a
987  *  n unused vnode will not be marked as referenced by a filesystem.
988  *  @param vp The vnode to mark.
989  *  @return Always 0.
990  */
991 int     vnode_addfsref(vnode_t vp);
992 
993 /*!
994  *  @function vnode_removefsref
995  *  @abstract Mark a vnode as no longer being stored in a filesystem hash.
996  *  @discussion Should only be called once on a vnode (during a reclaim), and only after the vnode has either been created with VNFS_ADDFSREF or marked by vnode_addfsref().
997  *  @param vp The vnode to unmark.
998  *  @return Always 0.
999  */
1000 int     vnode_removefsref(vnode_t vp);
1001 
1002 /*!
1003  *  @function vnode_hasdirtyblks
1004  *  @abstract Check if a vnode has dirty data waiting to be written to disk.
1005  *  @discussion Note that this routine is unsynchronized; it is only a snapshot and its result may cease to be true at the moment it is returned..
1006  *  @param vp The vnode to test.
1007  *  @return Nonzero if there are dirty blocks, 0 otherwise
1008  */
1009 int     vnode_hasdirtyblks(vnode_t vp);
1010 
1011 /*!
1012  *  @function vnode_hascleanblks
1013  *  @abstract Check if a vnode has clean buffers associated with it.
1014  *  @discussion Note that this routine is unsynchronized; it is only a snapshot and its result may cease to be true at the moment it is returned..
1015  *  @param vp The vnode to test.
1016  *  @return Nonzero if there are clean blocks, 0 otherwise.
1017  */
1018 int     vnode_hascleanblks(vnode_t vp);
1019 
1020 #define VNODE_ASYNC_THROTTLE    15
1021 /*!
1022  *  @function vnode_waitforwrites
1023  *  @abstract Wait for the number of pending writes on a vnode to drop below a target.
1024  *  @param vp The vnode to monitor.
1025  *  @param output_target Max pending write count with which to return.
1026  *  @param slpflag Flags for msleep().
1027  *  @param slptimeout Frequency with which to force a check for completion; increments of 10 ms.
1028  *  @param msg String to pass  msleep() .
1029  *  @return 0 for success, or an error value from msleep().
1030  */
1031 int     vnode_waitforwrites(vnode_t vp, int output_target, int slpflag, int slptimeout, const char *msg);
1032 
1033 /*!
1034  *  @function vnode_startwrite
1035  *  @abstract Increment the count of pending writes on a vnode.
1036  *  @param vp The vnode whose count to increment.
1037  */
1038 void    vnode_startwrite(vnode_t vp);
1039 
1040 /*!
1041  *  @function vnode_startwrite
1042  *  @abstract Decrement the count of pending writes on a vnode .
1043  *  @discussion Also wakes up threads waiting for the write count to drop, as in vnode_waitforwrites.
1044  *  @param vp The vnode whose count to decrement.
1045  */
1046 void    vnode_writedone(vnode_t vp);
1047 
1048 /*!
1049  *  @function vnode_vtype
1050  *  @abstract Return a vnode's type.
1051  *  @param vp The vnode whose type to grab.
1052  *  @return The vnode's type.
1053  */
1054 enum vtype      vnode_vtype(vnode_t vp);
1055 
1056 /*!
1057  *  @function vnode_vid
1058  *  @abstract Return a vnode's vid (generation number), which is constant from creation until reclaim.
1059  *  @param vp The vnode whose vid to grab.
1060  *  @return The vnode's vid.
1061  */
1062 uint32_t        vnode_vid(vnode_t vp);
1063 
1064 /*!
1065  *  @function vnode_isonexternalstorage
1066  *  @abstract Return whether or not the storage device backing a vnode is external or not.
1067  *  @param vp The vnode whose physical location is to be determined.
1068  *  @return TRUE if storage device is external, FALSE if otherwise.
1069  */
1070 boolean_t vnode_isonexternalstorage(vnode_t vp);
1071 
1072 /*!
1073  *  @function vnode_mountedhere
1074  *  @abstract Returns a pointer to a mount placed on top of a vnode, should it exist.
1075  *  @param vp The vnode from whom to take the covering mount.
1076  *  @return Pointer to mount covering a vnode, or NULL if none exists.
1077  */
1078 mount_t vnode_mountedhere(vnode_t vp);
1079 
1080 /*!
1081  *  @function vnode_mount
1082  *  @abstract Get the mount structure for the filesystem that a vnode belongs to.
1083  *  @param vp The vnode whose mount to grab.
1084  *  @return The mount, directly.
1085  */
1086 mount_t vnode_mount(vnode_t vp);
1087 
1088 /*!
1089  *  @function vnode_specrdev
1090  *  @abstract Return the device id of the device associated with a special file.
1091  *  @param vp The vnode whose device id to extract--vnode must be a special file.
1092  *  @return The device id.
1093  */
1094 dev_t   vnode_specrdev(vnode_t vp);
1095 
1096 /*!
1097  *  @function vnode_fsnode
1098  *  @abstract Gets the filesystem-specific data associated with a vnode.
1099  *  @param vp The vnode whose data to grab.
1100  *  @return The filesystem-specific data, directly.
1101  */
1102 void *  vnode_fsnode(vnode_t vp);
1103 
1104 /*!
1105  *  @function vnode_clearfsnode
1106  *  @abstract Sets a vnode's filesystem-specific data to be NULL.
1107  *  @discussion This routine should only be called when a vnode is no longer in use, i.e. during a VNOP_RECLAIM.
1108  *  @param vp The vnode whose data to clear out.
1109  */
1110 void    vnode_clearfsnode(vnode_t vp);
1111 
1112 /*!
1113  *  @function vnode_isvroot
1114  *  @abstract Determine if a vnode is the root of its filesystem.
1115  *  @param vp The vnode to test.
1116  *  @return Nonzero if the vnode is the root, 0 if it is not.
1117  */
1118 int     vnode_isvroot(vnode_t vp);
1119 
1120 /*!
1121  *  @function vnode_issystem
1122  *  @abstract Determine if a vnode is marked as a System vnode.
1123  *  @param vp The vnode to test.
1124  *  @return Nonzero if the vnode is a system vnode, 0 if it is not.
1125  */
1126 int     vnode_issystem(vnode_t vp);
1127 
1128 /*!
1129  *  @function vnode_ismount
1130  *  @abstract Determine if there is currently a mount occurring which will cover this vnode.
1131  *  @discussion Note that this is only a snapshot; a mount may begin or end at any time.
1132  *  @param vp The vnode to test.
1133  *  @return Nonzero if there is a mount in progress, 0 otherwise.
1134  */
1135 int     vnode_ismount(vnode_t vp);
1136 
1137 /*!
1138  *  @function vnode_isreg
1139  *  @abstract Determine if a vnode is a regular file.
1140  *  @param vp The vnode to test.
1141  *  @return Nonzero if the vnode is of type VREG, 0 otherwise.
1142  */
1143 int     vnode_isreg(vnode_t vp);
1144 
1145 /*!
1146  *  @function vnode_isdir
1147  *  @abstract Determine if a vnode is a directory.
1148  *  @param vp The vnode to test.
1149  *  @return Nonzero if the vnode is of type VDIR, 0 otherwise.
1150  */
1151 int     vnode_isdir(vnode_t vp);
1152 
1153 /*!
1154  *  @function vnode_islnk
1155  *  @abstract Determine if a vnode is a symbolic link.
1156  *  @param vp The vnode to test.
1157  *  @return Nonzero if the vnode is of type VLNK, 0 otherwise.
1158  */
1159 int     vnode_islnk(vnode_t vp);
1160 
1161 /*!
1162  *  @function vnode_isfifo
1163  *  @abstract Determine if a vnode is a named pipe.
1164  *  @param vp The vnode to test.
1165  *  @return Nonzero if the vnode is of type VFIFO, 0 otherwise.
1166  */
1167 int     vnode_isfifo(vnode_t vp);
1168 
1169 /*!
1170  *  @function vnode_isblk
1171  *  @abstract Determine if a vnode is a block device special file.
1172  *  @param vp The vnode to test.
1173  *  @return Nonzero if the vnode is of type VBLK, 0 otherwise.
1174  */
1175 int     vnode_isblk(vnode_t vp);
1176 
1177 /*!
1178  *  @function vnode_ischr
1179  *  @abstract Determine if a vnode is a character device special file.
1180  *  @param vp The vnode to test.
1181  *  @return Nonzero if the vnode is of type VCHR, 0 otherwise.
1182  */
1183 int     vnode_ischr(vnode_t vp);
1184 
1185 /*!
1186  *  @function vnode_isswap
1187  *  @abstract Determine if a vnode is being used as a swap file.
1188  *  @param vp The vnode to test.
1189  *  @return Nonzero if the vnode is being used as swap, 0 otherwise.
1190  */
1191 int     vnode_isswap(vnode_t vp);
1192 
1193 /*!
1194  *  @function vnode_isnamedstream
1195  *  @abstract Determine if a vnode is a named stream.
1196  *  @param vp The vnode to test.
1197  *  @return Nonzero if the vnode is a named stream, 0 otherwise.
1198  */
1199 int     vnode_isnamedstream(vnode_t vp);
1200 
1201 #ifdef KERNEL_PRIVATE
1202 /*!
1203  *  @function vnode_setasnamedstream
1204  *  @abstract Set svp as a named stream of vp and take appropriate references.
1205  *  @param vp The vnode whose namedstream has to be set.
1206  *  @param svp The namedstream vnode.
1207  *  @return 0 if the operation is successful, an error otherwise.
1208  */
1209 errno_t vnode_setasnamedstream(vnode_t vp, vnode_t svp);
1210 
1211 /*!
1212  *  @function vnode_setasfirmlink
1213  *  @abstract Set a vnode to act as a firmlink i.e. point to a target vnode.
1214  *  @param vp The vnode which is to be acted on as a firmlink.
1215  *  @param target_vp The vnode which will be the target of the firmlink.
1216  *  @return 0 if the operation is successful, an error otherwise.
1217  */
1218 errno_t vnode_setasfirmlink(vnode_t vp, vnode_t target_vp);
1219 
1220 /*!
1221  *  @function vnode_getfirmlink
1222  *  @abstract If a vnode is a firmlink, get its target vnode.
1223  *  @param vp The firmlink vnode.
1224  *  @param target_vp The firmlink traget vnode. This vnode is returned with an iocount.
1225  *  @return 0 if the operation is successful, an error otherwise.
1226  */
1227 errno_t vnode_getfirmlink(vnode_t vp, vnode_t *target_vp);
1228 
1229 #endif /* KERNEL_PRIVATE */
1230 
1231 /*!
1232  *  @function vnode_ismountedon
1233  *  @abstract Determine if a vnode is a block device on which a filesystem has been mounted.
1234  *  @discussion A block device marked as being mounted on cannot be opened.
1235  *  @param vp The vnode to test.
1236  *  @return Nonzero if the vnode is a block device on which an filesystem is mounted, 0 otherwise.
1237  */
1238 int     vnode_ismountedon(vnode_t vp);
1239 
1240 /*!
1241  *  @function vnode_setmountedon
1242  *  @abstract Set flags indicating that a block device vnode has been mounted as a filesystem.
1243  *  @discussion A block device marked as being mounted on cannot be opened.
1244  *  @param vp The vnode to set flags on, a block device.
1245  */
1246 void    vnode_setmountedon(vnode_t vp);
1247 
1248 /*!
1249  *  @function vnode_clearmountedon
1250  *  @abstract Clear flags indicating that a block device vnode has been mounted as a filesystem.
1251  *  @param vp The vnode to clear flags on, a block device.
1252  */
1253 void    vnode_clearmountedon(vnode_t vp);
1254 
1255 /*!
1256  *  @function vnode_isrecycled
1257  *  @abstract Check if a vnode is dead or in the process of being killed (recycled).
1258  *  @discussion This is only a snapshot: a vnode may start to be recycled, or go from dead to in use, at any time.
1259  *  @param vp The vnode to test.
1260  *  @return Nonzero if vnode is dead or being recycled, 0 otherwise.
1261  */
1262 int     vnode_isrecycled(vnode_t vp);
1263 
1264 /*!
1265  *  @function vnode_willberecycled
1266  *  @abstract Check if a vnode is marked for recycling when the last reference to it is released.
1267  *  @discussion This is only a snapshot: a vnode may start to be recycled, or go from dead to in use, at any time.
1268  *  @param vp The vnode to test.
1269  *  @return Nonzero if vnode is marked for recycling, 0 otherwise.
1270  */
1271 int     vnode_willberecycled(vnode_t vp);
1272 
1273 /*!
1274  *  @function vnode_isnocache
1275  *  @abstract Check if a vnode is set to not have its data cached in memory  (i.e. we write-through to disk and always read from disk).
1276  *  @param vp The vnode to test.
1277  *  @return Nonzero if vnode is set to not have data chached, 0 otherwise.
1278  */
1279 int     vnode_isnocache(vnode_t vp);
1280 
1281 /*!
1282  *  @function vnode_israge
1283  *  @abstract Check if a vnode is marked for rapid aging
1284  *  @param vp The vnode to test.
1285  *  @return Nonzero if vnode is marked for rapid aging, 0 otherwise
1286  */
1287 int     vnode_israge(vnode_t vp);
1288 
1289 /*!
1290  *  @function vnode_needssnapshots
1291  *  @abstract Check if a vnode needs snapshots events (regardless of its ctime status)
1292  *  @param vp The vnode to test.
1293  *  @return Nonzero if vnode needs snapshot events, 0 otherwise
1294  */
1295 int     vnode_needssnapshots(vnode_t vp);
1296 
1297 /*!
1298  *  @function vnode_setnocache
1299  *  @abstract Set a vnode to not have its data cached in memory (i.e. we write-through to disk and always read from disk).
1300  *  @param vp The vnode whose flags to set.
1301  */
1302 void    vnode_setnocache(vnode_t vp);
1303 
1304 /*!
1305  *  @function vnode_clearnocache
1306  *  @abstract Clear the flag on a vnode indicating that data should not be cached in memory (i.e. we write-through to disk and always read from disk).
1307  *  @param vp The vnode whose flags to clear.
1308  */
1309 void    vnode_clearnocache(vnode_t vp);
1310 
1311 /*!
1312  *  @function vnode_isnoreadahead
1313  *  @abstract Check if a vnode is set to not have data speculatively read in in hopes of future cache hits.
1314  *  @param vp The vnode to test.
1315  *  @return Nonzero if readahead is disabled, 0 otherwise.
1316  */
1317 int     vnode_isnoreadahead(vnode_t vp);
1318 
1319 /*!
1320  *  @function vnode_setnoreadahead
1321  *  @abstract Set a vnode to not have data speculatively read in in hopes of hitting in cache.
1322  *  @param vp The vnode on which to prevent readahead.
1323  */
1324 void    vnode_setnoreadahead(vnode_t vp);
1325 
1326 /*!
1327  *  @function vnode_clearnoreadahead
1328  *  @abstract Clear the flag indicating that a vnode should not have data speculatively read in.
1329  *  @param vp The vnode whose flag to clear.
1330  */
1331 void    vnode_clearnoreadahead(vnode_t vp);
1332 
1333 /*!
1334  *  @function vnode_isfastdevicecandidate
1335  *  @abstract Check if a vnode is a candidate to store on the fast device of a composite disk system
1336  *  @param vp The vnode which you want to test.
1337  *  @return Nonzero if the vnode is marked as a fast-device candidate
1338  */
1339 int     vnode_isfastdevicecandidate(vnode_t vp);
1340 
1341 /*!
1342  *  @function vnode_setfastdevicecandidate
1343  *  @abstract Mark a vnode as a candidate to store on the fast device of a composite disk system
1344  *  @discussion If the vnode is a directory, all its children will inherit this bit.
1345  *  @param vp The vnode which you want marked.
1346  */
1347 void    vnode_setfastdevicecandidate(vnode_t vp);
1348 
1349 /*!
1350  *  @function vnode_clearfastdevicecandidate
1351  *  @abstract Clear the status of a vnode being a candidate to store on the fast device of a composite disk system.
1352  *  @param vp The vnode whose flag to clear.
1353  */
1354 void    vnode_clearfastdevicecandidate(vnode_t vp);
1355 
1356 /*!
1357  *  @function vnode_isautocandidate
1358  *  @abstract Check if a vnode was automatically selected to be fast-dev candidate (see vnode_setfastdevicecandidate)
1359  *  @param vp The vnode which you want to test.
1360  *  @return Nonzero if the vnode was automatically marked as a fast-device candidate
1361  */
1362 int     vnode_isautocandidate(vnode_t vp);
1363 
1364 /*!
1365  *  @function vnode_setfastdevicecandidate
1366  *  @abstract Mark a vnode as an automatically selected candidate for storing on the fast device of a composite disk system
1367  *  @discussion If the vnode is a directory, all its children will inherit this bit.
1368  *  @param vp The vnode which you want marked.
1369  */
1370 void    vnode_setautocandidate(vnode_t vp);
1371 
1372 /*!
1373  *  @function vnode_clearautocandidate
1374  *  @abstract Clear the status of a vnode being an automatic candidate (see above)
1375  *  @param vp The vnode whose flag to clear.
1376  */
1377 void    vnode_clearautocandidate(vnode_t vp);
1378 
1379 /* left only for compat reasons as User code depends on this from getattrlist, for ex */
1380 
1381 /*!
1382  *  @function vnode_settag
1383  *  @abstract Set a vnode filesystem-specific "tag."
1384  *  @discussion Sets a tag indicating which filesystem a vnode belongs to, e.g. VT_HFS, VT_UDF, VT_ZFS.  The kernel never inspects this data, though the filesystem tags are defined in vnode.h; it is for the benefit of user programs via getattrlist.
1385  *  @param vp The vnode whose tag to set.
1386  */
1387 void    vnode_settag(vnode_t vp, int tag);
1388 
1389 /*!
1390  *  @function vnode_tag
1391  *  @abstract Get the vnode filesystem-specific "tag."
1392  *  @discussion Gets the tag indicating which filesystem a vnode belongs to, e.g. VT_HFS, VT_UDF, VT_ZFS.  The kernel never inspects this data, though the filesystem tags are defined in vnode.h; it is for the benefit of user programs via getattrlist.
1393  *  @param vp The vnode whose tag to grab.
1394  *  @return The tag.
1395  */
1396 int     vnode_tag(vnode_t vp);
1397 
1398 /*!
1399  *  @function vnode_getattr
1400  *  @abstract Get vnode attributes.
1401  *  @discussion Desired attributes are set with VATTR_SET_ACTIVE and VNODE_ATTR* macros.  Supported attributes are determined after call with VATTR_IS_SUPPORTED.
1402  *  @param vp The vnode whose attributes to grab.
1403  *  @param vap Structure containing: 1) A list of requested attributes 2) Space to indicate which attributes are supported and being returned 3) Space to return attributes.
1404  *  @param ctx Context for authentication.
1405  *  @return 0 for success or an error code.
1406  */
1407 int     vnode_getattr(vnode_t vp, struct vnode_attr *vap, vfs_context_t ctx);
1408 
1409 /*
1410  * Utility function to deal with 32/64 bit fsid
1411  */
1412 extern uint64_t vnode_get_va_fsid(struct vnode_attr *vap);
1413 
1414 /*!
1415  *  @function vnode_setattr
1416  *  @abstract Set vnode attributes.
1417  *  @discussion Attributes to set are marked with VATTR_SET_ACTIVE and VNODE_ATTR* macros.  Attributes successfully set are determined after call with VATTR_IS_SUPPORTED.
1418  *  @param vp The vnode whose attributes to set.
1419  *  @param vap Structure containing: 1) A list of attributes to set 2) Space for values for those attributes 3) Space to indicate which attributes were set.
1420  *  @param ctx Context for authentication.
1421  *  @return 0 for success or an error code.
1422  */
1423 int     vnode_setattr(vnode_t vp, struct vnode_attr *vap, vfs_context_t ctx);
1424 
1425 /*!
1426  *  @function vfs_rootvnode
1427  *  @abstract Returns the root vnode with an iocount.
1428  *  @discussion Caller must vnode_put() the root node when done.
1429  *  @return Pointer to root vnode if successful; error code if there is a problem taking an iocount.
1430  */
1431 vnode_t vfs_rootvnode(void);
1432 
1433 /*!
1434  *  @function vnode_uncache_credentials
1435  *  @abstract Clear out cached credentials on a vnode.
1436  *  @discussion When we authorize an action on a vnode, we cache the credential that was authorized and the actions it was authorized for in case a similar request follows.  This function destroys that caching.
1437  *  @param vp The vnode whose cache to clear.
1438  */
1439 void    vnode_uncache_credentials(vnode_t vp);
1440 
1441 /*!
1442  *  @function vnode_setmultipath
1443  *  @abstract Mark a vnode as being reachable by multiple paths, i.e. as a hard link.
1444  *  @discussion "Multipath" vnodes can be reached through more than one entry in the filesystem, and so must be handled differently for caching and event notification purposes.  A filesystem should mark a vnode with multiple hardlinks this way.
1445  *  @param vp The vnode to mark.
1446  */
1447 void    vnode_setmultipath(vnode_t vp);
1448 
1449 /*!
1450  *  @function vnode_vfsmaxsymlen
1451  *  @abstract Determine the maximum length of a symbolic link for the filesystem on which a vnode resides.
1452  *  @param vp The vnode for which to get filesystem symlink size cap.
1453  *  @return Max symlink length.
1454  */
1455 uint32_t  vnode_vfsmaxsymlen(vnode_t vp);
1456 
1457 /*!
1458  *  @function vnode_vfsisrdonly
1459  *  @abstract Determine if the filesystem to which a vnode belongs is mounted read-only.
1460  *  @param vp The vnode for which to get filesystem writeability.
1461  *  @return Nonzero if the filesystem is read-only, 0 otherwise.
1462  */
1463 int     vnode_vfsisrdonly(vnode_t vp);
1464 
1465 /*!
1466  *  @function vnode_vfstypenum
1467  *  @abstract Get the "type number" of the filesystem to which a vnode belongs.
1468  *  @discussion This is an archaic construct; most filesystems are assigned a type number based on the order in which they are registered with the system.
1469  *  @param vp The vnode whose filesystem to examine.
1470  *  @return The type number of the fileystem to which the vnode belongs.
1471  */
1472 int     vnode_vfstypenum(vnode_t vp);
1473 
1474 /*!
1475  *  @function vnode_vfsname
1476  *  @abstract Get the name of the filesystem to which a vnode belongs.
1477  *  @param vp The vnode whose filesystem to examine.
1478  *  @param buf Destination for vfs name: should have size MFSNAMELEN or greater.
1479  */
1480 void    vnode_vfsname(vnode_t vp, char *buf);
1481 
1482 /*!
1483  *  @function vnode_vfs64bitready
1484  *  @abstract Determine if the filesystem to which a vnode belongs is marked as ready to interact with 64-bit user processes.
1485  *  @param vp The vnode whose filesystem to examine.
1486  *  @return Nonzero if filesystem is marked ready for 64-bit interactions; 0 otherwise.
1487  */
1488 int     vnode_vfs64bitready(vnode_t vp);
1489 
1490 /* These should move to private ... not documenting for now */
1491 int     vfs_context_get_special_port(vfs_context_t, int, ipc_port_t *);
1492 int     vfs_context_set_special_port(vfs_context_t, int, ipc_port_t);
1493 
1494 /*!
1495  *  @function vfs_context_proc
1496  *  @abstract Get the BSD process structure associated with a vfs_context_t.
1497  *  @param ctx Context whose associated process to find.
1498  *  @return Process if available, NULL otherwise.
1499  */
1500 proc_t  vfs_context_proc(vfs_context_t ctx);
1501 
1502 /*!
1503  *  @function vfs_context_ucred
1504  *  @abstract Get the credential associated with a vfs_context_t.
1505  *  @discussion Succeeds if and only if the context has a thread, the thread has a task, and the task has a BSD proc.
1506  *  @param ctx Context whose associated process to find.
1507  *  @returns credential if process available; NULL otherwise
1508  */
1509 kauth_cred_t    vfs_context_ucred(vfs_context_t ctx);
1510 
1511 /*!
1512  *  @function vfs_context_pid
1513  *  @abstract Get the process id of the BSD process associated with a vfs_context_t.
1514  *  @param ctx Context whose associated process to find.
1515  *  @return Process id.
1516  */
1517 int     vfs_context_pid(vfs_context_t ctx);
1518 
1519 #ifdef KERNEL_PRIVATE
1520 /*!
1521  *  @function vfs_context_copy_audit_token
1522  *  @abstract Copy the audit token of the BSD process associated with a vfs_context_t.
1523  *  @param ctx Context whose associated process to find.
1524  *  @param token Pointer to audit token buffer which will receive a copy of the audit token
1525  *  @return 0 on success, non-zero if there was a problem obtaining the token
1526  */
1527 int     vfs_context_copy_audit_token(vfs_context_t ctx, audit_token_t *token);
1528 
1529 #endif /* KERNEL_PRIVATE */
1530 
1531 /*!
1532  *  @function vfs_context_issignal
1533  *  @abstract Get a bitfield of pending signals for the BSD process associated with a vfs_context_t.
1534  *  @discussion The bitfield is constructed using the sigmask() macro, in the sense of bits |= sigmask(SIGSEGV).
1535  *  @param ctx Context whose associated process to find.
1536  *  @return Bitfield of pending signals.
1537  */
1538 int     vfs_context_issignal(vfs_context_t ctx, sigset_t mask);
1539 
1540 /*!
1541  *  @function vfs_context_suser
1542  *  @abstract Determine if a vfs_context_t corresponds to the superuser.
1543  *  @param ctx Context to examine.
1544  *  @return 0 if context belongs to superuser, EPERM otherwise.
1545  */
1546 int     vfs_context_suser(vfs_context_t ctx);
1547 
1548 /*!
1549  *  @function vfs_context_is64bit
1550  *  @abstract Determine if a vfs_context_t corresponds to a 64-bit user process.
1551  *  @param ctx Context to examine.
1552  *  @return Nonzero if context is of 64-bit process, 0 otherwise.
1553  */
1554 int     vfs_context_is64bit(vfs_context_t ctx);
1555 
1556 /*!
1557  *  @function vfs_context_create
1558  *  @abstract Create a new vfs_context_t with appropriate references held.
1559  *  @discussion The context must be released with vfs_context_rele() when no longer in use.
1560  *  @param ctx Context to copy, or NULL to use information from running thread.
1561  *  @return The new context, or NULL in the event of failure.
1562  */
1563 vfs_context_t vfs_context_create(vfs_context_t ctx);
1564 
1565 #ifdef KERNEL_PRIVATE
1566 /*!
1567  *  @function vfs_context_create_with_proc
1568  *  @abstract Create a new vfs_context_t with appropriate references held, using the specified proc as a template.
1569  *  discussion The context must be released with vfs_context_rele() when no longer in use.
1570  *  @param proc Process to use as a template for the new context.
1571  *  @return The new context, or NULL in the event of failure.
1572  */
1573 vfs_context_t vfs_context_create_with_proc(proc_t proc);
1574 #endif /* KERNEL_PRIVATE */
1575 
1576 /*!
1577  *  @function vfs_context_rele
1578  *  @abstract Release references on components of a context and deallocate it.
1579  *  @discussion A context should not be referenced after vfs_context_rele has been called.
1580  *  @param ctx Context to release.
1581  *  @return Always 0.
1582  */
1583 int vfs_context_rele(vfs_context_t ctx);
1584 
1585 /*!
1586  *  @function vfs_context_current
1587  *  @abstract Get the vfs_context for the current thread, or the kernel context if there is no context for current thread.
1588  *  @discussion Kexts should not use this function--it is preferred to use vfs_context_create(NULL) and vfs_context_rele(), which ensure proper reference counting of underlying structures.
1589  *  @return Context for current thread, or kernel context if thread context is unavailable.
1590  */
1591 vfs_context_t vfs_context_current(void) __pure2;
1592 #ifdef KERNEL_PRIVATE
1593 int     vfs_context_bind(vfs_context_t);
1594 
1595 /*!
1596  *  @function vfs_ctx_skipatime
1597  *  @abstract Check to see if this context should skip updating a vnode's access times.
1598  *  @discussion  This is currently tied to the vnode rapid aging process.  If the process is marked for rapid aging,
1599  *  then the kernel should not update vnodes it touches for access time purposes.  This will check to see if the
1600  *  specified process and/or thread is marked for rapid aging when it manipulates vnodes.
1601  *  @param ctx The context being investigated.
1602  *  @return 1 if we should skip access time updates.
1603  *  @return 0 if we should NOT skip access time updates.
1604  */
1605 
1606 int     vfs_ctx_skipatime(vfs_context_t ctx);
1607 
1608 #endif
1609 
1610 /* Supported filesystem tags for vfs_[set|get]_thread_fs_private */
1611 #define FS_PRIVATE_TAG_APFS (1)
1612 
1613 /*!
1614  *  @function vfs_set_thread_fs_private
1615  *  @abstract Set the per-thread filesystem private data field.
1616  *  @discussion Allows a filesystem to store an implementation specific value in the thread struct.
1617  *  Note that this field is common to all filesystems thus re-entrancy should be taken into consideration.
1618  *  @param tag Filesystem identification tag.
1619  *  @param fs_private The value to be set.
1620  *  @return 0 for success, ENOTSUP if the filesystem tag is not supported.
1621  */
1622 int vfs_set_thread_fs_private(uint8_t tag, uint64_t fs_private);
1623 
1624 /*!
1625  *  @function vfs_get_thread_fs_private
1626  *  @abstract Return the per-thread filesystem private data field.
1627  *  @discussion Returns the per-thread value that was set by vfs_set_thread_fs_private().
1628  *  @param tag Filesystem identification tag.
1629  *  @param fs_private The stored per-thread value.
1630  *  @return 0 for success, ENOTSUP if the filesystem tag is not supported.
1631  */
1632 int vfs_get_thread_fs_private(uint8_t tag, uint64_t *fs_private);
1633 
1634 /*!
1635  *  @function vflush
1636  *  @abstract Reclaim the vnodes associated with a mount.
1637  *  @param mp The mount whose vnodes to kill.
1638  *  @param skipvp A specific vnode to not reclaim or to let interrupt an un-forced flush
1639  *  @param flags  Control which
1640  *  @discussion This function is used to clear out the vnodes associated with a mount as part of the unmount process.
1641  *  Its parameters can determine which vnodes to skip in the process and whether in-use vnodes should be forcibly reclaimed.
1642  *  Filesystems should call this function from their unmount code, because VFS code will always call it with SKIPROOT | SKIPSWAP | SKIPSYSTEM; filesystems
1643  *  must take care of such vnodes themselves.
1644  *       SKIPSYSTEM skip vnodes marked VSYSTEM
1645  *       FORCECLOSE force file closeure
1646  *       WRITECLOSE only close writeable files
1647  *       SKIPSWAP   skip vnodes marked VSWAP
1648  *       SKIPROOT   skip root vnodes marked VROOT
1649  *  @return 0 for success, EBUSY if vnodes were busy and FORCECLOSE was not set.
1650  */
1651 int     vflush(struct mount *mp, struct vnode *skipvp, int flags);
1652 
1653 /*!
1654  *  @function vnode_get
1655  *  @abstract Increase the iocount on a vnode.
1656  *  @discussion If vnode_get() succeeds, the resulting io-reference must be dropped with vnode_put().
1657  *  This function succeeds unless the vnode in question is dead or in the process of dying AND the current iocount is zero.
1658  *  This means that it can block an ongoing reclaim which is blocked behind some other iocount.
1659  *
1660  *  On success, vnode_get() returns with an iocount held on the vnode; this type of reference is intended to be held only for short periods of time (e.g.
1661  *  across a function call) and provides a strong guarantee about the life of the vnode; vnodes with positive iocounts cannot be
1662  *  recycled, and an iocount is required for any  operation on a vnode.  However, vnode_get() does not provide any guarantees
1663  *  about the identity of the vnode it is called on; unless there is a known existing iocount on the vnode at time the call is made,
1664  *  it could be recycled and put back in use before the vnode_get() succeeds, so the caller may be referencing a
1665  *  completely different vnode than was intended.  vnode_getwithref() and vnode_getwithvid()
1666  *  provide guarantees about vnode identity.
1667  *
1668  *  @return 0 for success, ENOENT if the vnode is dead and without existing io-reference.
1669  */
1670 int     vnode_get(vnode_t);
1671 
1672 /*!
1673  *  @function vnode_getwithvid
1674  *  @abstract Increase the iocount on a vnode, checking that the vnode is alive and has not changed vid (i.e. been recycled)
1675  *  @discussion If vnode_getwithvid() succeeds, the resulting io-reference must be dropped with vnode_put().
1676  *  This function succeeds unless the vnode in question is dead, in the process of dying, or has been recycled (and given a different vnode id).
1677  *  The intended usage is that a vnode is stored and its vid (vnode_vid(vp)) recorded while an iocount is held (example: a filesystem hash).  The
1678  *  iocount is then dropped, and time passes (perhaps locks are dropped and picked back up). Subsequently, vnode_getwithvid() is called to get an iocount,
1679  *  but we are alerted if the vnode has been recycled.
1680  *
1681  *  On success, vnode_getwithvid()  returns with an iocount held on the vnode; this type of reference is intended to be held only for short periods of time (e.g.
1682  *  across a function call) and provides a strong guarantee about the life of the vnode. vnodes with positive iocounts cannot be
1683  *  recycled. An iocount is required for any operation on a vnode.
1684  *  @return 0 for success, ENOENT if the vnode is dead, in the process of being reclaimed, or has been recycled and reused.
1685  */
1686 int     vnode_getwithvid(vnode_t, uint32_t);
1687 
1688 #ifdef BSD_KERNEL_PRIVATE
1689 int vnode_getwithvid_drainok(vnode_t, uint32_t);
1690 #endif /* BSD_KERNEL_PRIVATE */
1691 
1692 /*!
1693  *  @function vnode_getwithref
1694  *  @abstract Increase the iocount on a vnode on which a usecount (persistent reference) is held.
1695  *  @discussion If vnode_getwithref() succeeds, the resulting io-reference must be dropped with vnode_put().
1696  *  vnode_getwithref() will succeed on dead vnodes; it should fail with ENOENT on vnodes which are in the process of being reclaimed.
1697  *  Because it is only called with a usecount on the vnode, the caller is guaranteed that the vnode has not been
1698  *  reused for a different file, though it may now be dead and have deadfs vnops (which return errors like EIO, ENXIO, ENOTDIR).
1699  *  On success, vnode_getwithref() returns with an iocount held on the vnode; this type of reference is intended to be held only for short periods of time (e.g.
1700  *  across a function call) and provides a strong guarantee about the life of the vnode. vnodes with positive iocounts cannot be
1701  *  recycled. An iocount is required for any operation on a vnode.
1702  *  @return 0 for success, ENOENT if the vnode is dead, in the process of being reclaimed, or has been recycled and reused.
1703  */
1704 int     vnode_getwithref(vnode_t vp);
1705 
1706 #ifdef KERNEL_PRIVATE
1707 /*!
1708  *  @function vnode_getwithref_noblock
1709  *  @abstract Increase the iocount on a vnode on which a usecount (persistent reference) is held.
1710  *  @discussion Similar to vnode_getwithref() but returns ENOENT instead of
1711  *  blocking when the vnode is being reclaimed.
1712  *  @return 0 for success, ENOENT if the vnode is dead, in the process of being
1713  *  reclaimed, or has been recycled and reused.
1714  */
1715 int vnode_getwithref_noblock(vnode_t vp);
1716 #endif /* KERNEL_PRIVATE */
1717 
1718 /*!
1719  *  @function vnode_put
1720  *  @abstract Decrement the iocount on a vnode.
1721  *  @discussion vnode_put() is called to indicate that a vnode is no longer in active use.  It removes the guarantee that a
1722  *  vnode will not be recycled.  This routine should be used to release io references no matter how they were obtained.
1723  *  @param vp The vnode whose iocount to drop.
1724  *  @return Always 0.
1725  */
1726 int     vnode_put(vnode_t vp);
1727 
1728 /*!
1729  *  @function vnode_ref
1730  *  @abstract Increment the usecount on a vnode.
1731  *  @discussion If vnode_ref() succeeds, the resulting usecount must be released with vnode_rele(). vnode_ref() is called to obtain
1732  *  a persistent reference on a vnode.  This type of reference does not provide the same strong guarantee that a vnode will persist
1733  *  as does an iocount--it merely ensures that a vnode will not be reused to represent a different file.  However, a usecount may be
1734  *  held for extended periods of time, whereas an iocount is intended to be obtained and released quickly as part of performing a
1735  *  vnode operation.  A holder of a usecount must call vnode_getwithref()/vnode_put() in order to perform any operations on that vnode.
1736  *  @param vp The vnode on which to obtain a persistent reference.
1737  *  @return 0 for success; ENOENT if the vnode is dead or in the process of being recycled AND the calling thread is not the vnode owner.
1738  */
1739 int     vnode_ref(vnode_t vp);
1740 
1741 /*!
1742  *  @function vnode_rele
1743  *  @abstract Decrement the usecount on a vnode.
1744  *  @discussion vnode_rele() is called to relese a persistent reference on a vnode.  Releasing the last usecount
1745  *  opens the door for a vnode to be reused as a new file; it also triggers a VNOP_INACTIVE call to the filesystem,
1746  *  though that will not happen immediately if there are outstanding iocount references.
1747  *  @param vp The vnode whose usecount to drop.
1748  */
1749 void    vnode_rele(vnode_t vp);
1750 
1751 /*!
1752  *  @function vnode_isinuse
1753  *  @abstract Determine if the number of persistent (usecount) references on a vnode is greater than a given count.
1754  *  @discussion vnode_isinuse() compares a vnode's  usecount (corresponding to vnode_ref() calls) to its refcnt parameter
1755  *  (the number of references the caller expects to be on the vnode).  Note that "kusecount" references, corresponding
1756  *  to parties interested only in event notifications, e.g. open(..., O_EVTONLY), are not counted towards the total; the comparison is
1757  *  (usecount - kusecount > recnt).  It is
1758  *  also important to note that the result is only a snapshot; usecounts can change from moment to moment, and the result of vnode_isinuse
1759  *  may no longer be correct the very moment that the caller receives it.
1760  *  @param vp The vnode whose use-status to check.
1761  *  @param refcnt The threshold for saying that a vnode is in use.
1762  */
1763 int     vnode_isinuse(vnode_t vp, int refcnt);
1764 
1765 /*!
1766  *  @function vnode_hold
1767  *  @abstract Increase the holdcount on a vnode.
1768  *  @discussion the resulting hold must be dropped with vnode_drop().
1769  *  This function always succeeds and does not block but it can only be used in a context which already has a iocount or a usecount
1770  *  or under a synchronization primitive which can block the reclaim (for example a filesystem hash table lock which is also taken in the
1771  *  VNOP_RECLAIM implementation for that filesystem.)
1772  *  A holdcount only prevents the vnode from being freed and provides no other guarantees. It allows safe access to vnode pointer
1773  *  when the vnode access is no longer protected by an iocount, usecount or other sysnchronization primitive.
1774  *  @param vp The vnode whose holdcount has to be incremented.
1775  *
1776  */
1777 void     vnode_hold(vnode_t vp);
1778 
1779 /*!
1780  *  @function vnode_drop
1781  *  @abstract decrease the holdcount on vnode.
1782  *  @discussion If the holdcount goes to zero and the vnode has been reclaimed, the vnode may also be freed.
1783  *  Any access to the vnode after calling vnode_drop is unsafe unless it is a under a iocount or a usecount which has
1784  *  been acquired prior to calling vnode_drop.
1785  *  @param vp The vnode whose holdcount has to be decremented.
1786  *  @return vnode passed and NULLVP if the vnode was freed.
1787  */
1788 vnode_t  vnode_drop(vnode_t vp);
1789 
1790 /*!
1791  *  @function vnode_recycle
1792  *  @abstract Cause a vnode to be reclaimed and prepared for reuse.
1793  *  @discussion Like all vnode KPIs, must be called with an iocount on the target vnode.
1794  *  vnode_recycle() will mark that vnode for reclaim when all existing references are dropped.
1795  *  @param vp The vnode to recycle.
1796  *  @return 1 if the vnode was reclaimed (i.e. there were no existing references), 0 if it was only marked for future reclaim.
1797  */
1798 int     vnode_recycle(vnode_t vp);
1799 
1800 #ifdef KERNEL_PRIVATE
1801 
1802 #define VNODE_EVENT_DELETE              0x00000001      /* file was removed */
1803 #define VNODE_EVENT_WRITE               0x00000002      /* file or directory contents changed */
1804 #define VNODE_EVENT_EXTEND              0x00000004      /* ubc size increased */
1805 #define VNODE_EVENT_ATTRIB              0x00000008      /* attributes changed (suitable for permission changes if type unknown)*/
1806 #define VNODE_EVENT_LINK                0x00000010      /* link count changed */
1807 #define VNODE_EVENT_RENAME              0x00000020      /* vnode was renamed */
1808 #define VNODE_EVENT_PERMS               0x00000040      /* permissions changed: will cause a NOTE_ATTRIB */
1809 #define VNODE_EVENT_FILE_CREATED        0x00000080      /* file created in directory: will cause NOTE_WRITE */
1810 #define VNODE_EVENT_DIR_CREATED         0x00000100      /* directory created inside this directory: will cause NOTE_WRITE */
1811 #define VNODE_EVENT_FILE_REMOVED        0x00000200      /* file removed from this directory: will cause NOTE_WRITE */
1812 #define VNODE_EVENT_DIR_REMOVED         0x00000400      /* subdirectory from this directory: will cause NOTE_WRITE */
1813 
1814 #ifdef BSD_KERNEL_PRIVATE
1815 #define VNODE_NOTIFY_ATTRS              (VNODE_ATTR_BIT(va_fsid) | \
1816 	                                VNODE_ATTR_BIT(va_fileid)| \
1817 	                                VNODE_ATTR_BIT(va_mode)  | \
1818 	                                VNODE_ATTR_BIT(va_uid)   | \
1819 	                                VNODE_ATTR_BIT(va_document_id)   | \
1820 	                                VNODE_ATTR_BIT(va_dirlinkcount) | \
1821 	                                VNODE_ATTR_BIT(va_nlink))
1822 
1823 
1824 
1825 #endif /* BSD_KERNEL_PRIVATE  */
1826 
1827 /*!
1828  *  @function vnode_ismonitored
1829  *  @abstract Check whether a file has watchers that would make it useful to query a server
1830  *  for file changes.
1831  *  @param vp Vnode to examine.
1832  *  @discussion Will not reenter the filesystem.
1833  *  @return Zero if not monitored, nonzero if monitored.
1834  */
1835 int     vnode_ismonitored(vnode_t vp);
1836 
1837 
1838 /*!
1839  *  @function vnode_isdyldsharedcache
1840  *  @abstract Check whether a file is a dyld shared cache file.
1841  *  @param vp Vnode to examine.
1842  *  @discussion Will not reenter the filesystem.
1843  *  @return nonzero if a dyld shared cache file, zero otherwise.
1844  */
1845 int     vnode_isdyldsharedcache(vnode_t vp);
1846 
1847 
1848 /*!
1849  *  @function vn_authorize_unlink
1850  *  @abstract Authorize an unlink operation given the vfs_context_t
1851  *  @discussion Check if the context assocated with vfs_context_t is allowed to unlink the vnode vp in directory dvp.
1852  *  @param dvp Parent vnode of the file to be unlinked
1853  *  @param vp The vnode to be unlinked
1854  *  @param cnp A componentname containing the name of the file to be unlinked.  May be NULL.
1855  *  @param reserved Pass NULL
1856  *  @return returns zero if the operation is allowed, non-zero indicates the unlink is not authorized.
1857  */
1858 int     vn_authorize_unlink(vnode_t dvp, vnode_t vp, struct componentname *cnp, vfs_context_t ctx, void *reserved);
1859 
1860 
1861 /*!
1862  *  @function vn_authorize_rmdir
1863  *  @abstract Authorize an rmdir operation given the vfs_context_t
1864  *  @discussion Check if the context assocated with vfs_context_t is allowed to rmdir the vnode vp in directory dvp.
1865  *  @param dvp Parent vnode of the directory to be rmdir'ed
1866  *  @param vp The vnode to be rmdir'ed
1867  *  @param cnp A componentname containing the name of the file to be rmdir'ed.  May be NULL.
1868  *  @param reserved Pass NULL
1869  *  @return returns zero if the operation is allowed, non-zero indicates the rmdir is not authorized.
1870  */
1871 int     vn_authorize_rmdir(vnode_t dvp, vnode_t vp, struct componentname *cnp, vfs_context_t ctx, void *reserved);
1872 
1873 /*!
1874  *  @function vn_getpath_fsenter
1875  *  @abstract Attempt to get a vnode's path, willing to enter the filesystem.
1876  *  @discussion Paths to vnodes are not always straightforward: a file with multiple hard-links will have multiple pathnames,
1877  *  and it is sometimes impossible to determine a vnode's full path.  vn_getpath_fsenter() may enter the filesystem
1878  *  to try to construct a path, so filesystems should be wary of calling it.
1879  *  @param vp Vnode whose path to get
1880  *  @param pathbuf Buffer in which to store path.
1881  *  @param len Destination for length of resulting path string.  Result will include NULL-terminator in count--that is, "len"
1882  *  will be strlen(pathbuf) + 1.
1883  *  @return 0 for success or an error.
1884  */
1885 int     vn_getpath_fsenter(struct vnode *vp, char *pathbuf, int *len);
1886 
1887 /*!
1888  *  @function vn_getpath_no_firmlink
1889  *  @abstract Attempt to get a vnode's path without a firm-link translation.
1890  *  @discussion Paths to vnodes are not always straightforward: a file with multiple hard-links will have multiple pathnames,
1891  *  and it is sometimes impossible to determine a vnode's full path. Like vn_getpath, it will not reenter the filesystem.
1892  *  @param vp Vnode whose path to get
1893  *  @param pathbuf Buffer in which to store path.
1894  *  @param len Destination for length of resulting path string.  Result will include NULL-terminator in count--that is, "len"
1895  *  will be strlen(pathbuf) + 1.
1896  *  @return 0 for success or an error.
1897  */
1898 int     vn_getpath_no_firmlink(struct vnode *vp, char *pathbuf, int *len);
1899 
1900 /*!
1901  *  @function vn_getpath_fsenter_with_parent
1902  *  @abstract Attempt to get a vnode's path by entering the file system if needed given a vnode and it's directory vnode.
1903  *  @discussion Same as vn_getpath_fsenter but is given the directory vnode as well as the target vnode. Used
1904  *  to get the path from the vnode while performing rename, rmdir, and unlink. This is done to avoid potential
1905  *  dead lock if another thread is doing a forced unmount.
1906  *  @param dvp Containing directory vnode. Must be holding an IO count.
1907  *  @param vp  Vnode whose path to get. Must be holding an IO count.
1908  *  @param pathbuf Buffer in which to store path.
1909  *  @param len Destination for length of resulting path string.  Result will include NULL-terminator in count--that is, "len"
1910  *  will be strlen(pathbuf) + 1.
1911  *  @return 0 for success or an error.
1912  */
1913 int     vn_getpath_fsenter_with_parent(struct vnode *dvp, struct vnode *vp, char *pathbuf, int *len);
1914 
1915 /*!
1916  *  @function vn_getpath_ext
1917  *  @abstract Attempt to get a vnode's path without rentering filesystem (unless passed an option to allow)
1918  *  @discussion Paths to vnodes are not always straightforward: a file with multiple hard-links will have multiple pathnames,
1919  *  and it is sometimes impossible to determine a vnode's full path.  vn_getpath_fsenter() may enter the filesystem
1920  *  to try to construct a path, so filesystems should be wary of calling it.
1921  *  @param vp Vnode whose path to get
1922  *  @param dvp parent vnode of vnode whose path to get, can be NULL if not available.
1923  *  @param pathbuf Buffer in which to store path.
1924  *  @param len Destination for length of resulting path string.  Result will include NULL-terminator in count--that is, "len"
1925  *  will be strlen(pathbuf) + 1.
1926  *  @param flags flags for controlling behavior.
1927  *  @return 0 for success or an error.
1928  */
1929 #define VN_GETPATH_NEW 0x0
1930 int     vn_getpath_ext(struct vnode *vp, struct vnode *dvp, char *pathbuf, size_t *len, int flags);
1931 
1932 /*!
1933  *  @function vn_getpath_ext_with_mntlen
1934  *  @abstract Attempt to get a vnode's path without rentering filesystem (unless passed an option to allow)
1935  *  @discussion Paths to vnodes are not always straightforward: a file with multiple hard-links will have multiple pathnames,
1936  *  and it is sometimes impossible to determine a vnode's full path.  vn_getpath_fsenter() may enter the filesystem
1937  *  to try to construct a path, so filesystems should be wary of calling it.
1938  *  @param vp Vnode whose path to get
1939  *  @param dvp parent vnode of vnode whose path to get, can be NULL if not available.
1940  *  @param pathbuf Buffer in which to store path.
1941  *  @param len Destination for length of resulting path string.  Result will include NULL-terminator in count--that is, "len"
1942  *  will be strlen(pathbuf) + 1.
1943  *  @param mntlen Destination for length of path that is the mount point for the returned path. Will always be less than or equal to len.
1944  *  will be strlen(pathbuf) + 1.
1945  *  @param flags flags for controlling behavior.
1946  *  @return 0 for success or an error.
1947  */
1948 int     vn_getpath_ext_with_mntlen(struct vnode *vp, struct vnode *dvp, char *pathbuf, size_t *len, size_t *mntlen, int flags);
1949 
1950 /* supported flags for vn_getpath_ext */
1951 #define VN_GETPATH_FSENTER              0x0001 /* Can re-enter filesystem */
1952 #define VN_GETPATH_NO_FIRMLINK          0x0002
1953 #define VN_GETPATH_VOLUME_RELATIVE      0x0004 /* also implies VN_GETPATH_NO_FIRMLINK */
1954 #define VN_GETPATH_NO_PROCROOT          0x0008 /* Give the non chrooted path for a process */
1955 #define VN_GETPATH_CHECK_MOVED          0x0010 /* Return EAGAIN if the parent hierarchy is modified */
1956 
1957 #endif /* KERNEL_PRIVATE */
1958 
1959 #define VNODE_UPDATE_PARENT     0x01
1960 #define VNODE_UPDATE_NAMEDSTREAM_PARENT VNODE_UPDATE_PARENT
1961 #define VNODE_UPDATE_NAME       0x02
1962 #define VNODE_UPDATE_CACHE      0x04
1963 #define VNODE_UPDATE_PURGE      0x08
1964 #ifdef BSD_KERNEL_PRIVATE
1965 #define VNODE_UPDATE_PURGEFIRMLINK      0x10
1966 #endif
1967 /*!
1968  *  @function vnode_update_identity
1969  *  @abstract Update vnode data associated with the vfs cache.
1970  *  @discussion The vfs namecache is central to tracking vnode-identifying data and to locating files on the system.  vnode_update_identity()
1971  *  is used to update vnode data associated with the cache. It can set a vnode's parent and/or name (also potentially set by vnode_create())
1972  *  or flush cache data.
1973  *  @param vp The vnode whose information to update.
1974  *  @param dvp Parent to set on the vnode if VNODE_UPDATE_PARENT is used.
1975  *  @param name Name to set in the cache for the vnode if VNODE_UPDATE_NAME is used.  The buffer passed in can be subsequently freed, as the cache
1976  *  does its own name storage.  String should be NULL-terminated unless length and hash value are specified.
1977  *  @param name_len Length of name, if known.  Passing 0 causes the cache to determine the length itself.
1978  *  @param name_hashval Hash value of name, if known.  Passing 0 causes the cache to hash the name itself.
1979  *  @param flags VNODE_UPDATE_PARENT: set parent.  VNODE_UPDATE_NAME: set name.  VNODE_UPDATE_CACHE: flush cache entries for hard links
1980  *  associated with this file.  VNODE_UPDATE_PURGE: flush cache entries for hard links and children of this file.
1981  */
1982 void    vnode_update_identity(vnode_t vp, vnode_t dvp, const char *name, int name_len, uint32_t name_hashval, int flags);
1983 
1984 /*!
1985  *  @function vn_bwrite
1986  *  @abstract System-provided implementation of "bwrite" vnop.
1987  *  @discussion This routine is available for filesystems which do not want to implement their own "bwrite" vnop.  It just calls
1988  *  buf_bwrite() without modifying its arguments.
1989  *  @param ap Standard parameters to a bwrite vnop.
1990  *  @return Results of buf_bwrite directly.
1991  */
1992 int     vn_bwrite(struct vnop_bwrite_args *ap);
1993 
1994 /*!
1995  *  @function vnode_authorize
1996  *  @abstract Authorize a kauth-style action on a vnode.
1997  *  @discussion Operations on dead vnodes are always allowed (though never do anything).
1998  *  @param vp Vnode on which to authorize action.
1999  *  @param dvp Parent of "vp," can be NULL.
2000  *  @param action Action to authorize, e.g. KAUTH_VNODE_READ_DATA.  See bsd/sys/kauth.h.
2001  *  @param ctx Context for which to authorize actions.
2002  *  @return EACCESS if permission is denied.  0 if operation allowed.  Various errors from lower layers.
2003  */
2004 int     vnode_authorize(vnode_t vp, vnode_t dvp, kauth_action_t action, vfs_context_t ctx);
2005 
2006 #ifdef KERNEL_PRIVATE
2007 /*!
2008  *  @function vnode_attr_authorize_init
2009  *  @abstract Initialize attributes for authorization of a kauth-style action on a file system object based on its attributes.
2010  *  @discussion This function tells the caller what attributes may be required for a authorizing
2011  *  a kauth style action.
2012  *  @param vap attributes of file system object on which to authorize action.
2013  *  @param dvap attributes of parent of file system object, can be NULL.
2014  *  @param action Action to authorize, e.g. KAUTH_VNODE_READ_DATA.  See bsd/sys/kauth.h.
2015  *  @param ctx Context for which to authorize actions.
2016  *  @return EINVAL if a required parameters are not passed (for eg. not passing dvap when the action is KAUTH_ACTION_DELETE), 0 otherwise.
2017  */
2018 #define VNODE_ATTR_AUTHORIZE_AVAILABLE          0x01
2019 int     vnode_attr_authorize_init(struct vnode_attr *vap, struct vnode_attr *dvap, kauth_action_t action, vfs_context_t ctx);
2020 
2021 /*!
2022  *  @function vnode_attr_authorize
2023  *  @abstract Authorize a kauth-style action on a file system object based on its attributes.
2024  *  @discussion This function should be preceded by a call to vnode_attr_authorize_init to get what attributes are required.
2025  *  @param vap attributes of file system object on which to authorize action.
2026  *  @param dvap attributes of parent of file system object, can be NULL.
2027  *  @param mp  mountpoint to which file system object belongs, can be NULL.
2028  *  @param action Action to authorize, e.g. KAUTH_VNODE_READ_DATA.  See bsd/sys/kauth.h.
2029  *  @param ctx Context for which to authorize actions.
2030  *  @return EACCESS if permission is denied.  0 if operation allowed.  Various errors from lower layers.
2031  */
2032 int     vnode_attr_authorize(struct vnode_attr *vap, struct vnode_attr *dvap, mount_t mp, kauth_action_t action, vfs_context_t ctx);
2033 #endif /* KERNEL_PRIVATE */
2034 
2035 /*!
2036  *  @function vnode_authattr
2037  *  @abstract Given a vnode_attr structure, determine what kauth-style actions must be authorized in order to set those attributes.
2038  *  @discussion vnode_authorize requires kauth-style actions; if we want to set a vnode_attr structure on a vnode, we need to translate
2039  *  the set of attributes to a set of kauth-style actions.  This routine will return errors for certain obviously disallowed, or
2040  *  incoherent, actions.
2041  *  @param vp The vnode on which to authorize action.
2042  *  @param vap Pointer to vnode_attr struct containing desired attributes to set and their values.
2043  *  @param actionp Destination for set of actions to authorize
2044  *  @param ctx Context for which to authorize actions.
2045  *  @return 0 (and a result in "actionp" for success.  Otherwise, an error code.
2046  */
2047 int     vnode_authattr(vnode_t vp, struct vnode_attr *vap, kauth_action_t *actionp, vfs_context_t ctx);
2048 
2049 /*!
2050  *  @function vnode_authattr_new
2051  *  @abstract Initialize and validate file creation parameters with respect to the current context.
2052  *  @discussion vnode_authattr_new() will fill in unitialized values in the vnode_attr struct with defaults, and will validate the structure
2053  *  with respect to the current context for file creation.
2054  *  @param dvp The directory in which creation will occur.
2055  *  @param vap Pointer to vnode_attr struct containing desired attributes to set and their values.
2056  *  @param noauth If 1, treat the caller as the superuser, i.e. do not check permissions.
2057  *  @param ctx Context for which to authorize actions.
2058  *  @return KAUTH_RESULT_ALLOW for success, an error to indicate invalid or disallowed attributes.
2059  */
2060 int     vnode_authattr_new(vnode_t dvp, struct vnode_attr *vap, int noauth, vfs_context_t ctx);
2061 
2062 /*!
2063  *  @function vnode_close
2064  *  @abstract Close a file as opened with vnode_open().
2065  *  @discussion vnode_close() drops the refcount (persistent reference) picked up in vnode_open() and calls down to the filesystem with VNOP_CLOSE.  It should
2066  *  be called with both an iocount and a refcount on the vnode and will drop both.
2067  *  @param vp The vnode to close.
2068  *  @param flags Flags to close: FWASWRITTEN indicates that the file was written to.
2069  *  @param ctx Context against which to validate operation.
2070  *  @return 0 for success or an error from the filesystem.
2071  */
2072 errno_t vnode_close(vnode_t vp, int flags, vfs_context_t ctx);
2073 
2074 /*!
2075  *  @function vn_getpath
2076  *  @abstract Construct the path to a vnode.
2077  *  @discussion Paths to vnodes are not always straightforward: a file with multiple hard-links will have multiple pathnames,
2078  *  and it is sometimes impossible to determine a vnode's full path.  vn_getpath() will not enter the filesystem.
2079  *  @param vp The vnode whose path to obtain.
2080  *  @param pathbuf Destination for pathname; should be of size MAXPATHLEN
2081  *  @param len Destination for length of resulting path string.  Result will include NULL-terminator in count--that is, "len"
2082  *  will be strlen(pathbuf) + 1.
2083  *  @return 0 for success or an error code.
2084  */
2085 int vn_getpath(struct vnode *vp, char *pathbuf, int *len);
2086 
2087 /*!
2088  *  @function vnode_notify
2089  *  @abstract Send a notification up to VFS.
2090  *  @param vp Vnode for which to provide notification.
2091  *  @param vap Attributes for that vnode, to be passed to fsevents.
2092  *  @discussion Filesystem determines which attributes to pass up using
2093  *  vfs_get_notify_attributes(&vap).  The most specific events possible should be passed,
2094  *  e.g. VNODE_EVENT_FILE_CREATED on a directory rather than just VNODE_EVENT_WRITE, but
2095  *  a less specific event can be passed up if more specific information is not available.
2096  *  Will not reenter the filesystem.
2097  *  @return 0 for success, else an error code.
2098  */
2099 int     vnode_notify(vnode_t vp, uint32_t events, struct vnode_attr *vap);
2100 
2101 /*!
2102  *  @function vfs_get_notify_attributes
2103  *  @abstract Determine what attributes are required to send up a notification with vnode_notify().
2104  *  @param vap Structure to initialize and activate required attributes on.
2105  *  @discussion Will not reenter the filesystem.
2106  *  @return 0 for success, nonzero for error (currently always succeeds).
2107  */
2108 int     vfs_get_notify_attributes(struct vnode_attr *vap);
2109 
2110 /*
2111  * Flags for the vnode_lookup and vnode_open
2112  */
2113 #define VNODE_LOOKUP_NOFOLLOW           0x01
2114 #define VNODE_LOOKUP_NOCROSSMOUNT       0x02
2115 #define VNODE_LOOKUP_CROSSMOUNTNOWAIT   0x04
2116 #define VNODE_LOOKUP_NOFOLLOW_ANY       0x08
2117 /*!
2118  *  @function vnode_lookup
2119  *  @abstract Convert a path into a vnode.
2120  *  @discussion This routine is a thin wrapper around xnu-internal lookup routines; if successful,
2121  *  it returns with an iocount held on the resulting vnode which must be dropped with vnode_put().
2122  *  @param path Path to look up.
2123  *  @param flags VNODE_LOOKUP_NOFOLLOW: do not follow symbolic links.  VNODE_LOOKUP_NOCROSSMOUNT: do not cross mount points.
2124  *  VNODE_LOOKUP_NOFOLLOW_ANY: no symlinks allowed in path
2125  *  @return Results 0 for success or an error code.
2126  */
2127 errno_t vnode_lookup(const char *path, int flags, vnode_t *vpp, vfs_context_t ctx);
2128 
2129 #ifdef KERNEL_PRIVATE
2130 /*!
2131  *  @function vnode_lookup starting from a directory vnode (only if path is relative)
2132  *  @abstract Convert a path into a vnode.
2133  *  @discussion This routine is a thin wrapper around xnu-internal lookup routines; if successful,
2134  *  it returns with an iocount held on the resulting vnode which must be dropped with vnode_put().
2135  *  @param path Path to look up.
2136  *  @param flags VNODE_LOOKUP_NOFOLLOW: do not follow symbolic links.  VNODE_LOOKUP_NOCROSSMOUNT: do not cross mount points.
2137  *  VNODE_LOOKUP_NOFOLLOW_ANY: no symlinks allowed in path
2138  *  @param start_dvp vnode of directory to start lookup from. This parameter is ignored if path is absolute. start_dvp should
2139  *         have an iocount on it.
2140  *  @return Results 0 for success or an error code.
2141  */
2142 errno_t vnode_lookupat(const char *path, int flags, vnode_t *vpp, vfs_context_t ctx, vnode_t start_dvp);
2143 #endif
2144 
2145 /*!
2146  *  @function vnode_open
2147  *  @abstract Open a file identified by a path--roughly speaking an in-kernel open(2).
2148  *  @discussion If vnode_open() succeeds, it returns with both an iocount and a usecount on the
2149  *  returned vnode. Both will be release once vnode_close is called.
2150  *  @param path Path to look up.
2151  *  @param fmode e.g. O_NONBLOCK, O_APPEND; see bsd/sys/fcntl.h.
2152  *  @param cmode Permissions with which to create file if it does not exist.
2153  *  @param flags Same as vnode_lookup().
2154  *  @param vpp Destination for vnode.
2155  *  @param ctx Context with which to authorize open/creation.
2156  *  @return 0 for success or an error code.
2157  */
2158 errno_t vnode_open(const char *path, int fmode, int cmode, int flags, vnode_t *vpp, vfs_context_t ctx);
2159 
2160 /*
2161  * exported vnode operations
2162  */
2163 
2164 /*!
2165  *  @function vnode_iterate
2166  *  @abstract Perform an operation on (almost) all vnodes from a given mountpoint.
2167  *  @param mp Mount whose vnodes to operate on.
2168  *  @param flags
2169  *  VNODE_RELOAD			Mark inactive vnodes for recycle.
2170  *  VNODE_WAIT
2171  *  VNODE_WRITEABLE             Only examine vnodes with writes in progress.
2172  *  VNODE_WITHID			No effect.
2173  *  VNODE_NOLOCK_INTERNAL	No effect.
2174  *  VNODE_NODEAD			No effect.
2175  *  VNODE_NOSUSPEND		No effect.
2176  *  VNODE_ITERATE_ALL           No effect.
2177  *  VNODE_ITERATE_ACTIVE        No effect.
2178  *  VNODE_ITERATE_INACTIVE	No effect.
2179  *
2180  *  @param callout Function to call on each vnode.
2181  *  @param arg Argument which will be passed to callout along with each vnode.
2182  *  @return Zero for success, else an error code.  Will return 0 immediately if there are no vnodes hooked into the mount.
2183  *  @discussion Skips vnodes which are dead, in the process of reclaim, suspended, or of type VNON.
2184  */
2185 int     vnode_iterate(struct mount *mp, int flags, int (*callout)(struct vnode *, void *), void *arg);
2186 
2187 /*
2188  * flags passed into vnode_iterate
2189  */
2190 #define VNODE_RELOAD                    0x01
2191 #define VNODE_WAIT                              0x02
2192 #define VNODE_WRITEABLE                 0x04
2193 #define VNODE_WITHID                    0x08
2194 #define VNODE_NOLOCK_INTERNAL   0x10
2195 #define VNODE_NODEAD                    0x20
2196 #define VNODE_NOSUSPEND                 0x40
2197 #define VNODE_ITERATE_ALL               0x80
2198 #define VNODE_ITERATE_ACTIVE    0x100
2199 #define VNODE_ITERATE_INACTIVE  0x200
2200 #ifdef BSD_KERNEL_PRIVATE
2201 #define VNODE_ALWAYS            0x400
2202 #define VNODE_DRAINO            0x800
2203 #define VNODE_PAGER             0x1000
2204 #define VNODE_NOBLOCK           0x2000
2205 #endif /* BSD_KERNEL_PRIVATE */
2206 
2207 /*
2208  * return values from callback
2209  */
2210 #define VNODE_RETURNED          0       /* done with vnode, reference can be dropped */
2211 #define VNODE_RETURNED_DONE     1       /* done with vnode, reference can be dropped, terminate iteration */
2212 #define VNODE_CLAIMED           2       /* don't drop reference */
2213 #define VNODE_CLAIMED_DONE      3       /* don't drop reference, terminate iteration */
2214 
2215 /*!
2216  *  @function vn_revoke
2217  *  @abstract Invalidate all references to a vnode.
2218  *  @discussion Reclaims the vnode, giving it deadfs vnops (though not halting operations which are already in progress).
2219  *  Also reclaims all aliased vnodes (important for devices).  People holding usecounts on the vnode, e.g. processes
2220  *  with the file open, will find that all subsequent operations but closing the file fail.
2221  *  @param vp The vnode to revoke.
2222  *  @param flags Unused.
2223  *  @param ctx Context against which to validate operation.
2224  *  @return 0 always.
2225  */
2226 int     vn_revoke(vnode_t vp, int flags, vfs_context_t ctx);
2227 
2228 /* namecache function prototypes */
2229 /*!
2230  *  @function cache_lookup
2231  *  @abstract Check for a filename in a directory using the VFS name cache.
2232  *  @discussion cache_lookup() will flush negative cache entries and return 0 if the operation of the cn_nameiop is CREATE or RENAME.
2233  *  Often used from the filesystem during a lookup vnop.  The filesystem will be called to if there is a negative cache entry for a file,
2234  *  so it can make sense to initially check for negative entries (and possibly lush them).
2235  *  @param dvp Directory in which lookup is occurring.
2236  *  @param vpp Destination for vnode pointer.
2237  *  @param cnp Various data about lookup, e.g. filename and intended operation.
2238  *  @return ENOENT: the filesystem has previously added a negative entry with cache_enter() to indicate that there is no
2239  *  file of the given name in "dp."  -1: successfully found a cached vnode (vpp is set).  0: No data in the cache, or operation is CREATE/RENAME.
2240  */
2241 int     cache_lookup(vnode_t dvp, vnode_t *vpp, struct componentname *cnp);
2242 
2243 /*!
2244  *  @function cache_enter
2245  *  @abstract Add a (name,vnode) entry to the VFS namecache.
2246  *  @discussion Generally used to add a cache entry after a successful filesystem-level lookup or to add a
2247  *  negative entry after one which did not find its target.
2248  *  @param dvp Directory in which file lives.
2249  *  @param vp File to add to cache. A non-NULL vp is stored for rapid access; a NULL vp indicates
2250  *  that there is no such file in the directory and speeds future failed lookups.
2251  *  @param cnp Various data about lookup, e.g. filename and intended operation.
2252  */
2253 void    cache_enter(vnode_t dvp, vnode_t vp, struct componentname *cnp);
2254 
2255 /*!
2256  *  @function cache_purge
2257  *  @abstract Remove all data relating to a vnode from the namecache.
2258  *  @discussion Will flush all hardlinks to the vnode as well as all children (should any exist).  Logical
2259  *  to use when cached data about a vnode becomes invalid, for instance in an unlink.
2260  *  @param vp The vnode to purge.
2261  */
2262 void    cache_purge(vnode_t vp);
2263 
2264 /*!
2265  *  @function cache_purge_negatives
2266  *  @abstract Remove all negative cache entries which are children of a given vnode.
2267  *  @discussion Appropriate to use when negative cache information for a directory could have
2268  *  become invalid, e.g. after file creation.
2269  *  @param vp The vnode whose negative children to purge.
2270  */
2271 void    cache_purge_negatives(vnode_t vp);
2272 
2273 
2274 /*
2275  * Global string-cache routines.  You can pass zero for nc_hash
2276  * if you don't know it (add_name() will then compute the hash).
2277  * There are no flags for now but maybe someday.
2278  */
2279 /*!
2280  *  @function vfs_addname
2281  *  @abstract Deprecated
2282  *  @discussion vnode_update_identity() and vnode_create() make vfs_addname() unnecessary for kexts.
2283  */
2284 const char *vfs_addname(const char *name, uint32_t len, uint32_t nc_hash, uint32_t flags);
2285 
2286 /*!
2287  *  @function vfs_removename
2288  *  @abstract Deprecated
2289  *  @discussion vnode_update_identity() and vnode_create() make vfs_addname() unnecessary for kexts.
2290  */
2291 int   vfs_removename(const char *name);
2292 
2293 /*!
2294  *  @function vcount
2295  *  @abstract Count total references to a given file, disregarding "kusecount" (event listener, as with O_EVTONLY) references.
2296  *  @discussion For a regular file, just return (usecount-kusecount); for device files, return the sum over all
2297  *  vnodes 'v' which reference that device of (usecount(v) - kusecount(v)).  Note that this is merely a snapshot and could be
2298  *  invalid by the time the caller checks the result.
2299  *  @param vp The vnode whose references to count.
2300  *  @return Count of references.
2301  */
2302 int     vcount(vnode_t vp);
2303 
2304 /*!
2305  *  @function vn_path_package_check
2306  *  @abstract Figure out if a path corresponds to a Mac OS X package.
2307  *  @discussion  Determines if the extension on a path is a known OS X extension type.
2308  *  @param vp Unused.
2309  *  @param path Path to check.
2310  *  @param pathlen Size of path buffer.
2311  *  @param component Set to index of start of last path component if the path is found to be a package. Set to -1 if
2312  *  the path is not a known package type.
2313  *  @return 0 unless some parameter was invalid, in which case EINVAL is returned.  Determine package-ness by checking
2314  *  what *component is set to.
2315  */
2316 int vn_path_package_check(vnode_t vp, char *path, int pathlen, int *component);
2317 
2318 #ifdef KERNEL_PRIVATE
2319 /*!
2320  *  @function vn_searchfs_inappropriate_name
2321  *  @abstract Figure out if the component is inappropriate for a SearchFS query.
2322  *  @param name component to check
2323  *  @param len length of component.
2324  *  @return 0 if no match, 1 if inappropriate.
2325  */
2326 int vn_searchfs_inappropriate_name(const char *name, int len);
2327 #endif
2328 
2329 /*!
2330  *  @function vn_rdwr
2331  *  @abstract Read from or write to a file.
2332  *  @discussion vn_rdwr() abstracts the details of constructing a uio and picking a vnode operation to allow
2333  *  simple in-kernel file I/O.
2334  *  @param rw UIO_READ for a read, UIO_WRITE for a write.
2335  *  @param vp The vnode on which to perform I/O.
2336  *  @param base Start of buffer into which to read or from which to write data.
2337  *  @param len Length of buffer.
2338  *  @param offset Offset within the file at which to start I/O.
2339  *  @param segflg What kind of address "base" is.   See uio_seg definition in sys/uio.h.  UIO_SYSSPACE for kernelspace, UIO_USERSPACE for userspace.
2340  *  UIO_USERSPACE32 and UIO_USERSPACE64 are in general preferred, but vn_rdwr will make sure that has the correct address sizes.
2341  *  @param ioflg Defined in vnode.h, e.g. IO_NOAUTH, IO_NOCACHE.
2342  *  @param cred Credential to pass down to filesystem for authentication.
2343  *  @param aresid Destination for amount of requested I/O which was not completed, as with uio_resid().
2344  *  @param p Process requesting I/O.
2345  *  @return 0 for success; errors from filesystem, and EIO if did not perform all requested I/O and the "aresid" parameter is NULL.
2346  */
2347 int     vn_rdwr(enum uio_rw rw, struct vnode *vp, caddr_t base, int len, off_t offset, enum uio_seg segflg, int ioflg, kauth_cred_t cred, int *aresid, proc_t p);
2348 
2349 /*!
2350  *  @function vn_rdwr_64
2351  *  @abstract Read from or write to a file.
2352  *  @discussion vn_rdwr_64() abstracts the details of constructing a uio and picking a vnode operation to allow
2353  *  simple in-kernel file I/O.
2354  *  @param rw UIO_READ for a read, UIO_WRITE for a write.
2355  *  @param vp The vnode on which to perform I/O.
2356  *  @param base Start of buffer into which to read or from which to write data.
2357  *  @param len Length of buffer.
2358  *  @param offset Offset within the file at which to start I/O.
2359  *  @param segflg What kind of address "base" is.   See uio_seg definition in sys/uio.h.  UIO_SYSSPACE for kernelspace, UIO_USERSPACE for userspace.
2360  *  UIO_USERSPACE32 and UIO_USERSPACE64 are in general preferred, but vn_rdwr will make sure that has the correct address sizes.
2361  *  @param ioflg Defined in vnode.h, e.g. IO_NOAUTH, IO_NOCACHE.
2362  *  @param cred Credential to pass down to filesystem for authentication.
2363  *  @param aresid Destination for amount of requested I/O which was not completed, as with uio_resid().
2364  *  @param p Process requesting I/O.
2365  *  @return 0 for success; errors from filesystem, and EIO if did not perform all requested I/O and the "aresid" parameter is NULL.
2366  */
2367 int     vn_rdwr_64(enum uio_rw rw, struct vnode *vp, uint64_t base, int64_t len, off_t offset, enum uio_seg segflg, int ioflg, kauth_cred_t cred, int64_t *aresid, struct proc *p);
2368 
2369 #ifdef KERNEL_PRIVATE
2370 /*!
2371  *  @function vnode_radvise
2372  *  @abstract perform an advisory read on the vnode.
2373  *  @param vp vnode on which to perform I/O. Caller should have acquired an iocount prior to calling this function.
2374  *  @param offset offset to begin reading from.
2375  *  @param len number of bytes to read.
2376  *  @param ctx Context against which to validate operation.
2377  *  @return 0 for success; errors from filesystem, and EINVAL if offset or len is not valid.
2378  */
2379 errno_t vnode_rdadvise(vnode_t vp, off_t offset, int len, vfs_context_t ctx);
2380 #endif
2381 
2382 /*!
2383  *  @function vnode_getname
2384  *  @abstract Get the name of a vnode from the VFS namecache.
2385  *  @discussion Not all vnodes have names, and vnode names can change (notably, hardlinks).  Use this routine at your own risk.
2386  *  The string is returned with a refcount incremented in the cache; callers must call vnode_putname() to release that reference.
2387  *  @param vp The vnode whose name to grab.
2388  *  @return The name, or NULL if unavailable.
2389  */
2390 const char      *vnode_getname(vnode_t vp);
2391 
2392 /*!
2393  *  @function vnode_putname
2394  *  @abstract Release a reference on a name from the VFS cache.
2395  *  @discussion Should be called on a string obtained with vnode_getname().
2396  *  @param name String to release.
2397  */
2398 void    vnode_putname(const char *name);
2399 
2400 /*!
2401  *  @function vnode_getparent
2402  *  @abstract Get an iocount on the parent of a vnode.
2403  *  @discussion A vnode's parent may change over time or be reclaimed, so vnode_getparent() may return different
2404  *  results at different times (e.g. a multiple-hardlink file). The parent is returned with an iocount which must
2405  *  subsequently be dropped with vnode_put().
2406  *  @param vp The vnode whose parent to grab.
2407  *  @return Parent if available, else NULL.
2408  */
2409 vnode_t vnode_getparent(vnode_t vp);
2410 
2411 /*!
2412  *  @function vnode_setdirty
2413  *  @abstract Mark the vnode as having data or metadata that needs to be written out during reclaim
2414  *  @discussion The vnode should be marked as dirty anytime a file system defers flushing of data or meta-data associated with it.
2415  *  @param vp the vnode to mark as dirty
2416  *  @return 0 if successful else an error code.
2417  */
2418 int     vnode_setdirty(vnode_t vp);
2419 
2420 /*!
2421  *  @function vnode_cleardirty
2422  *  @abstract Mark the vnode as clean i.e. all its data or metadata has been flushed
2423  *  @discussion The vnode should be marked as clean whenever the file system is done flushing data or meta-data associated with it.
2424  *  @param vp the vnode to clear as being dirty
2425  *  @return 0 if successful else an error code.
2426  */
2427 int     vnode_cleardirty(vnode_t vp);
2428 
2429 /*!
2430  *  @function vnode_isdirty
2431  *  @abstract Determine if a vnode is marked dirty.
2432  *  @discussion The vnode should be marked as clean whenever the file system is done flushing data or meta-data associated with it.
2433  *  @param vp the vnode to test.
2434  *  @return Non-zero if the vnode is dirty, 0 otherwise.
2435  */
2436 int     vnode_isdirty(vnode_t vp);
2437 
2438 #ifdef KERNEL_PRIVATE
2439 /*!
2440  *  @function vnode_lookup_continue_needed
2441  *  @abstract Determine whether vnode needs additional processing in VFS before being opened.
2442  *  @discussion If result is zero, filesystem can open this vnode.  If result is nonzero,
2443  *  additional processing is needed in VFS (e.g. symlink, mountpoint).  Nonzero results should
2444  *  be passed up to VFS.
2445  *  @param vp Vnode to consider opening (found by filesystem).
2446  *  @param cnp Componentname as passed to filesystem from VFS.
2447  *  @result 0 to indicate that a vnode can be opened, or an error that should be passed up to VFS.
2448  */
2449 int vnode_lookup_continue_needed(vnode_t vp, struct componentname *cnp);
2450 
2451 /*!
2452  *  @function vnode_isonssd
2453  *  @abstract Return whether or not the storage device backing a vnode is a solid state drive
2454  *  @param vp The vnode whose backing store properties are to be queried
2455  *  @return TRUE if storage device is an SSD, FALSE if otherwise.
2456  */
2457 boolean_t vnode_isonssd(vnode_t vp);
2458 
2459 /*!
2460  *  @function vnode_istty
2461  *  @abstract Determine if the given vnode represents a tty device.
2462  *  @param vp Vnode to examine.
2463  *  @result Non-zero to indicate that the vnode represents a tty device. Zero otherwise.
2464  */
2465 int vnode_istty(vnode_t vp);
2466 
2467 /*!
2468  *  @function bdevvp
2469  *  @abstract create a vnode for a given dev_t
2470  *  @result non-zero to indicate failure, vnode provided in *vpp arg
2471  */
2472 int bdevvp(dev_t dev, struct vnode **vpp);
2473 
2474 /*
2475  *  @function vnode_getfromfd
2476  *  @abstract get a vnode from a file descriptor
2477  *  @result non-zero to indicate failure, vnode provided in *vpp arg
2478  */
2479 int vnode_getfromfd(vfs_context_t ctx, int fd, vnode_t *vpp);
2480 
2481 /*
2482  * @function vnode_parent
2483  * @abstract Get the parent of a vnode.
2484  * @param vp The vnode whose parent to grab.
2485  * @return Parent if available, else NULL.
2486  */
2487 vnode_t vnode_parent(vnode_t vp);
2488 
2489 /*
2490  * @function vnode_getparent_and_name
2491  * @abstract Get an iocount on the parent of a vnode and the name of a vnode from the VFS namecache.
2492  * @discussion Combined version of vnode_getparent() and vnode_getname() to acquire both vnode name and parent
2493  * without releasing the name cache lock in interim. The parent is returned with an iocount which must
2494  * subsequently be dropped with vnode_put(). callers must call vnode_putname() to release the name reference.
2495  * @param vp The vnode whose parent and name to grab.
2496  * @param out_pvp A pointer to the output vnode parent.
2497  * @param out_name A pointer to the output vnode name.
2498  */
2499 void vnode_getparent_and_name(vnode_t vp, vnode_t *out_pvp, const char **out_name);
2500 
2501 /*
2502  * @function vfs_context_thread
2503  * @abstract Return the Mach thread associated with a vfs_context_t.
2504  * @param ctx The context to use.
2505  * @return The thread for this context, or NULL, if there is not one.
2506  */
2507 thread_t vfs_context_thread(vfs_context_t ctx);
2508 
2509 /*
2510  * @function vfs_context_task
2511  * @abstract Return the Mach task associated with a vfs_context_t.
2512  * @param ctx The context to use.
2513  * @return The task for this context, or NULL, if there is not one.
2514  */
2515 task_t vfs_context_task(vfs_context_t ctx);
2516 
2517 /*!
2518  *  @function vnode_isauthfs
2519  *  @abstract Determine if the given vnode is on an authenticated volume.
2520  *  @param vp Vnode to examine.
2521  *  @result Non-zero to indicate that the vnode is on an authenticated volume. Zero otherwise.
2522  */
2523 int vnode_isauthfs(vnode_t vp);
2524 
2525 #endif /* KERNEL_PRIVATE */
2526 
2527 #ifdef BSD_KERNEL_PRIVATE
2528 /* Not in export list so can be private */
2529 struct stat;
2530 int     vn_stat(struct vnode *vp, void * sb, kauth_filesec_t *xsec, int isstat64, int needsrealdev,
2531     vfs_context_t ctx);
2532 int     vn_stat_noauth(struct vnode *vp, void * sb, kauth_filesec_t *xsec, int isstat64, int needsrealdev,
2533     vfs_context_t ctx, struct ucred *file_cred);
2534 int     vaccess(mode_t file_mode, uid_t uid, gid_t gid,
2535     mode_t acc_mode, kauth_cred_t cred);
2536 int     check_mountedon(dev_t dev, enum vtype type, int  *errorp);
2537 int vn_getcdhash(struct vnode *vp, off_t offset, unsigned char *cdhash);
2538 void    vnode_reclaim(vnode_t);
2539 vnode_t current_workingdir(void);
2540 void    *vnode_vfsfsprivate(vnode_t);
2541 struct vfsstatfs *vnode_vfsstatfs(vnode_t);
2542 uint32_t vnode_vfsvisflags(vnode_t);
2543 uint32_t vnode_vfscmdflags(vnode_t);
2544 int     vnode_is_openevt(vnode_t);
2545 void    vnode_set_openevt(vnode_t);
2546 void    vnode_clear_openevt(vnode_t);
2547 int     vnode_isstandard(vnode_t);
2548 int     vnode_makeimode(int, int);
2549 enum vtype      vnode_iftovt(int);
2550 int     vnode_vttoif(enum vtype);
2551 int     vnode_isshadow(vnode_t);
2552 boolean_t vnode_on_reliable_media(vnode_t);
2553 /*
2554  * Indicate that a file has multiple hard links.  VFS will always call
2555  * VNOP_LOOKUP on this vnode.  Volfs will always ask for it's parent
2556  * object ID (instead of using the v_parent pointer).
2557  */
2558 void vnode_setparent(vnode_t, vnode_t);
2559 void vnode_setname(vnode_t, char *);
2560 #if CONFIG_IOSCHED
2561 vnode_t vnode_mountdevvp(vnode_t);
2562 #endif
2563 #endif /* BSD_KERNEL_PRIVATE */
2564 
2565 #ifdef KERNEL_PRIVATE
2566 /*!
2567  *  @function vnode_getname_printable
2568  *  @abstract Get a non-null printable name of a vnode.
2569  *  @Used to make sure a printable name is returned for all vnodes. If a name exists or can be artificially created, the routine creates a new entry in the VFS namecache. Otherwise, the function returns an artificially created vnode name which is safer and easier to use. vnode_putname_printable() should be used to release names obtained by this routine.
2570  *  @param vp The vnode whose name to grab.
2571  *  @return The printable name.
2572  */
2573 const char *vnode_getname_printable(vnode_t vp);
2574 /*!
2575  *  @function vnode_putname_printable
2576  *  @abstract Release a reference on a name from the VFS cache if it was added by the matching vnode_getname_printable() call.
2577  *  @param name String to release.
2578  */
2579 void vnode_putname_printable(const char *name);
2580 #endif // KERNEL_PRIVATE
2581 
2582 /*!
2583  *  @function vnode_getbackingvnode
2584  *  @abstract If the input vnode is a NULLFS mirrored vnode, then return the vnode it wraps.
2585  *  @Used to un-mirror files, primarily for security purposes. On success, out_vp is always set to a vp with an iocount. The caller must release the iocount.
2586  *  @param in_vp The vnode being asked about
2587  *  @param out_vpp A pointer to the output vnode, unchanged on error
2588  *  @return 0 on Success, ENOENT if in_vp doesn't mirror anything, EINVAL on parameter errors.
2589  */
2590 int vnode_getbackingvnode(vnode_t in_vp, vnode_t* out_vpp);
2591 
2592 /*
2593  * Helper functions for implementing VNOP_GETATTRLISTBULK for a filesystem
2594  */
2595 
2596 /*!
2597  *  @function vfs_setup_vattr_from_attrlist
2598  *  @abstract Setup a vnode_attr structure given an attrlist structure.
2599  *  @Used by a VNOP_GETATTRLISTBULK implementation to setup a vnode_attr structure from a attribute list. It also returns the fixed size of the attribute buffer required.
2600  *  @warning this forces new fork attr behavior, i.e. reinterpret forkattr bits as ATTR_CMNEXT
2601  *  @param alp Pointer to attribute list structure.
2602  *  @param vap Pointer to vnode_attr structure.
2603  *  @param obj_vtype Type of object - If VNON is passed, then the type is ignored and common, file and dir attrs are used to initialise the vattrs. If set to VDIR, only common and directory attributes are used. For all other types, only common and file attrbutes are used.
2604  *  @param attr_fixed_sizep Returns the fixed length required in the attrbute buffer for the object. NULL should be passed if it is not required.
2605  *  @param ctx vfs context of caller.
2606  *  @return error.
2607  */
2608 errno_t vfs_setup_vattr_from_attrlist(struct attrlist *alp, struct vnode_attr *vap, enum vtype obj_vtype, ssize_t *attr_fixed_sizep, vfs_context_t ctx);
2609 
2610 /*!
2611  *  @function vfs_attr_pack
2612  *  @abstract Pack a vnode_attr structure into a buffer in the same format as getattrlist(2).
2613  *  @Used by a VNOP_GETATTRLISTBULK implementation to pack data provided into a vnode_attr structure into a buffer the way getattrlist(2) does.
2614  *  @param vp If available, the vnode for which the attributes are being given, NULL if vnode is not available (which will usually be the case for a VNOP_GETATTRLISTBULK implementation.
2615  *  @param uio - a uio_t initialised with one iovec..
2616  *  @param alp - Pointer to an attrlist structure.
2617  *  @param options - options for call (same as options for getattrlistbulk(2)).
2618  *  @param vap Pointer to a filled in vnode_attr structure. Data from the vnode_attr structure will be used to copy and lay out the data in the required format for getatrlistbulk(2) by this function.
2619  *  @param fndesc Currently unused
2620  *  @param ctx vfs context of caller.
2621  *  @return error.
2622  */
2623 errno_t vfs_attr_pack(vnode_t vp, uio_t uio, struct attrlist *alp, uint64_t options, struct vnode_attr *vap, void *fndesc, vfs_context_t ctx);
2624 
2625 /*!
2626  *  @function vfs_attr_pack_ex
2627  *  @abstract Pack a vnode_attr structure into a buffer in the same format as getattrlist(2).
2628  *  @Used by a VNOP_GETATTRLISTBULK implementation to pack data provided into a vnode_attr structure into a buffer the way getattrlist(2) does.
2629  *  @param mp the mount structure for the filesystem the packing operation is happening on.
2630  *  @param vp If available, the vnode for which the attributes are being given, NULL if vnode is not available (which will usually be the case for a VNOP_GETATTRLISTBULK implementation.
2631  *  @param uio - a uio_t initialised with one iovec..
2632  *  @param alp - Pointer to an attrlist structure.
2633  *  @param options - options for call (same as options for getattrlistbulk(2)).
2634  *  @param vap Pointer to a filled in vnode_attr structure. Data from the vnode_attr structure will be used to copy and lay out the data in the required format for getatrlistbulk(2) by this function.
2635  *  @param fndesc Currently unused
2636  *  @param ctx vfs context of caller.
2637  *  @return error.
2638  */
2639 errno_t vfs_attr_pack_ext(mount_t mp, vnode_t vp, uio_t uio, struct attrlist *alp, uint64_t options, struct vnode_attr *vap, void *fndesc, vfs_context_t ctx);
2640 
2641 #ifdef KERNEL_PRIVATE
2642 
2643 /* vnode manipulations for devices */
2644 int vnode_cmp_chrtoblk(vnode_t vp, vnode_t blk_vp);
2645 
2646 // Returns a value suitable, safe and consistent for tracing and logging
2647 vm_offset_t kdebug_vnode(vnode_t vp);
2648 int vn_pathconf(vnode_t, int, int32_t *, vfs_context_t);
2649 int vnode_should_flush_after_write(vnode_t vp, int ioflag);
2650 void vfs_setowner(mount_t mp, uid_t uid, gid_t gid);
2651 uint64_t vfs_idle_time(mount_t mp);
2652 // Required until XsanFS is fixed...
2653 #ifndef vnode_usecount
2654 int vnode_usecount(vnode_t vp);
2655 #endif
2656 int vnode_writecount(vnode_t vp);
2657 int vnode_iocount(vnode_t vp);
2658 void vnode_rele_ext(vnode_t, int, int);
2659 int is_package_name(const char *name, int len);
2660 int vfs_context_issuser(vfs_context_t);
2661 int vfs_context_iskernel(vfs_context_t);
2662 vfs_context_t vfs_context_kernel(void) __pure2;         /* get from 1st kernel thread */
2663 vnode_t vfs_context_cwd(vfs_context_t);
2664 vnode_t vfs_context_get_cwd(vfs_context_t); /* get cwd with iocount */
2665 int vnode_isnoflush(vnode_t);
2666 void vnode_setnoflush(vnode_t);
2667 void vnode_clearnoflush(vnode_t);
2668 #if CONFIG_IO_COMPRESSION_STATS
2669 void vnode_iocs_record_and_free(vnode_t);
2670 #endif /* CONFIG_IO_COMPRESSION_STATS */
2671 
2672 #define BUILDPATH_NO_FS_ENTER     0x1 /* Use cache values, do not enter file system */
2673 #define BUILDPATH_CHECKACCESS     0x2 /* Check if parents have search rights */
2674 #define BUILDPATH_CHECK_MOVED     0x4 /* Return EAGAIN if the parent hierarchy is modified */
2675 #define BUILDPATH_VOLUME_RELATIVE 0x8 /* Return path relative to the nearest mount point */
2676 #define BUILDPATH_NO_FIRMLINK     0x10 /* Return non-firmlinked path */
2677 #define BUILDPATH_NO_PROCROOT     0x20 /* Return path relative to system root, not the process root */
2678 
2679 int vnode_issubdir(vnode_t vp, vnode_t dvp, int *is_subdir, vfs_context_t ctx);
2680 
2681 struct vniodesc;
2682 typedef struct vniodesc *vniodesc_t;
2683 
2684 #define VNIO_SUPPORT_PRESENT
2685 errno_t vnio_openfd(int fd, vniodesc_t *vniop);
2686 errno_t vnio_close(vniodesc_t);
2687 errno_t vnio_read(vniodesc_t, uio_t);
2688 vnode_t vnio_vnode(vniodesc_t);
2689 
2690 int     cache_lookup_ext(vnode_t dvp, vnode_t *vpp, struct componentname *cnp,
2691     int flags);
2692 #define CACHE_LOOKUP_ALLHITS    0x01    /* report all hits, even negatives for CREATE or RENAME */
2693 
2694 #endif // KERNEL_PRIVATE
2695 
2696 #ifdef XNU_KERNEL_PRIVATE
2697 int     build_path(vnode_t first_vp, char *buff, int buflen, int *outlen, int flags, vfs_context_t ctx);
2698 #endif
2699 
2700 __END_DECLS
2701 
2702 #endif /* KERNEL */
2703 
2704 /*
2705  * Structure for vnode level IO compression stats
2706  */
2707 
2708 #define IOCS_BUFFER_NUM_SIZE_BUCKETS         10
2709 #define IOCS_BUFFER_MAX_BUCKET               9
2710 #define IOCS_BUFFER_NUM_COMPRESSION_BUCKETS  7
2711 #define IOCS_BLOCK_NUM_SIZE_BUCKETS          16
2712 
2713 struct io_compression_stats {
2714 	uint64_t uncompressed_size;
2715 	uint64_t compressed_size;
2716 	uint32_t buffer_size_compression_dist[IOCS_BUFFER_NUM_SIZE_BUCKETS][IOCS_BUFFER_NUM_COMPRESSION_BUCKETS];
2717 	uint32_t block_compressed_size_dist[IOCS_BLOCK_NUM_SIZE_BUCKETS];
2718 };
2719 typedef struct io_compression_stats *io_compression_stats_t;
2720 
2721 #define IOCS_SBE_PATH_LEN             128
2722 #define IOCS_PATH_START_BYTES_TO_COPY 108
2723 #define IOCS_PATH_END_BYTES_TO_COPY   20 /* Includes null termination */
2724 
2725 #define IOCS_SYSCTL_LIVE                  0x00000001
2726 #define IOCS_SYSCTL_STORE_BUFFER_RD_ONLY  0x00000002
2727 #define IOCS_SYSCTL_STORE_BUFFER_MARK     0x00000004
2728 
2729 struct iocs_store_buffer_entry {
2730 	char     path_name[IOCS_SBE_PATH_LEN];
2731 	struct io_compression_stats iocs;
2732 };
2733 
2734 #ifdef KERNEL_PRIVATE
2735 boolean_t vnode_is_rsr(vnode_t);
2736 #endif
2737 
2738 #endif /* !_VNODE_H_ */
2739