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