bsd/sys/mount_internal.h

   1 /*
   2  * Copyright (c) 2000-2011 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, 1991, 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  *      @(#)mount.h     8.21 (Berkeley) 5/20/95
  62  */
  63 /*
  64  * NOTICE: This file was modified by McAfee Research in 2004 to introduce
  65  * support for mandatory and extensible security protections.  This notice
  66  * is included in support of clause 2.2 (b) of the Apple Public License,
  67  * Version 2.0.
  68  */
  69
  70 #ifndef _SYS_MOUNT_INTERNAL_H_
  71 #define _SYS_MOUNT_INTERNAL_H_
  72
  73 #include <sys/appleapiopts.h>
  74 #ifndef KERNEL
  75 #include <sys/ucred.h>
  76 #else
  77 #include <sys/kernel_types.h>
  78 #include <sys/namei.h>
  79 #endif
  80 #include <sys/queue.h>
  81 #include <sys/lock.h>
  82 #include <net/radix.h>
  83 #include <sys/socket.h>         /* XXX for AF_MAX */
  84 #include <sys/vfs_context.h>            /* XXX for AF_MAX */
  85 #include <sys/mount.h>
  86 #include <sys/cdefs.h>
  87
  88 struct label;
  89
  90 #if defined(__i386__) || defined(__x86_64__)
  91 typedef uint64_t  pending_io_t;
  92 #define INCR_PENDING_IO(a, b) OSAddAtomic64((int64_t)(a), (int64_t *)&(b));
  93 #else
  94 typedef uint32_t  pending_io_t;
  95 #define INCR_PENDING_IO(a, b) OSAddAtomic((int32_t)(a), (int32_t *)&(b));
  96 #endif
  97
  98
  99 /*
 100  * Structure per mounted file system.  Each mounted file system has an
 101  * array of operations and an instance record.  The file systems are
 102  * put on a doubly linked list.
 103  */
 104 TAILQ_HEAD(vnodelst, vnode);
 105
 106 struct mount {
 107         TAILQ_ENTRY(mount) mnt_list;            /* mount list */
 108         int32_t         mnt_count;              /* reference on the mount */
 109         lck_mtx_t       mnt_mlock;              /* mutex that protects mount point */
 110         struct vfsops   *mnt_op;                /* operations on fs */
 111         struct vfstable *mnt_vtable;            /* configuration info */
 112         struct vnode    *mnt_vnodecovered;      /* vnode we mounted on */
 113         struct vnodelst mnt_vnodelist;          /* list of vnodes this mount */
 114         struct vnodelst mnt_workerqueue;                /* list of vnodes this mount */
 115         struct vnodelst mnt_newvnodes;          /* list of vnodes this mount */
 116         uint32_t                mnt_flag;               /* flags */
 117         uint32_t                mnt_kern_flag;          /* kernel only flags */
 118         uint32_t                mnt_compound_ops;       /* Available compound operations */
 119         uint32_t                mnt_lflag;                      /* mount life cycle flags */
 120         uint32_t                mnt_maxsymlinklen;      /* max size of short symlink */
 121         struct vfsstatfs        mnt_vfsstat;            /* cache of filesystem stats */
 122         qaddr_t         mnt_data;               /* private data */
 123         /* Cached values of the IO constraints for the device */
 124         uint32_t        mnt_maxreadcnt;         /* Max. byte count for read */
 125         uint32_t        mnt_maxwritecnt;        /* Max. byte count for write */
 126         uint32_t        mnt_segreadcnt;         /* Max. segment count for read */
 127         uint32_t        mnt_segwritecnt;        /* Max. segment count for write */
 128         uint32_t        mnt_maxsegreadsize;     /* Max. segment read size  */
 129         uint32_t        mnt_maxsegwritesize;    /* Max. segment write size */
 130         uint32_t        mnt_alignmentmask;      /* Mask of bits that aren't addressable via DMA */
 131         uint32_t        mnt_devblocksize;       /* the underlying device block size */
 132         uint32_t        mnt_ioqueue_depth;      /* the maxiumum number of commands a device can accept */
 133         uint32_t        mnt_ioscale;            /* scale the various throttles/limits imposed on the amount of I/O in flight */
 134         uint32_t        mnt_ioflags;            /* flags for  underlying device */
 135         pending_io_t    mnt_pending_write_size __attribute__((aligned(sizeof(pending_io_t))));  /* byte count of pending writes */
 136         pending_io_t    mnt_pending_read_size  __attribute__((aligned(sizeof(pending_io_t))));  /* byte count of pending reads */
 137         struct timeval  mnt_last_write_issued_timestamp;
 138         struct timeval  mnt_last_write_completed_timestamp;
 139
 140         lck_rw_t        mnt_rwlock;             /* mutex readwrite lock */
 141         lck_mtx_t       mnt_renamelock;         /* mutex that serializes renames that change shape of tree */
 142         vnode_t         mnt_devvp;              /* the device mounted on for local file systems */
 143         uint32_t        mnt_devbsdunit;         /* the BSD unit number of the device */
 144         uint64_t        mnt_throttle_mask;      /* the throttle mask of what devices will be affected by I/O from this mnt */
 145         void            *mnt_throttle_info;     /* used by the throttle code */
 146         int32_t         mnt_crossref;           /* refernces to cover lookups  crossing into mp */
 147         int32_t         mnt_iterref;            /* refernces to cover iterations; drained makes it -ve  */
 148 #if CONFIG_TRIGGERS
 149         int32_t         mnt_numtriggers;        /* num of trigger vnodes for this mount */
 150         vfs_trigger_callback_t *mnt_triggercallback;
 151         void            *mnt_triggerdata;
 152 #endif
 153         /* XXX 3762912 hack to support HFS filesystem 'owner' */
 154         uid_t           mnt_fsowner;
 155         gid_t           mnt_fsgroup;
 156
 157         struct label    *mnt_mntlabel;          /* MAC mount label */
 158         struct label    *mnt_fslabel;           /* MAC default fs label */
 159
 160         /*
 161          * cache the rootvp of the last mount point
 162          * in the chain in the mount struct pointed
 163          * to by the vnode sitting in '/'
 164          * this cache is used to shortcircuit the
 165          * mount chain traversal and allows us
 166          * to traverse to the true underlying rootvp
 167          * in 1 easy step inside of 'cache_lookup_path'
 168          *
 169          * make sure to validate against the cached vid
 170          * in case the rootvp gets stolen away since
 171          * we don't take an explicit long term reference
 172          * on it when we mount it
 173          */
 174         vnode_t         mnt_realrootvp;
 175         uint32_t        mnt_realrootvp_vid;
 176         /*
 177          * bumped each time a mount or unmount
 178          * occurs... its used to invalidate
 179          * 'mnt_realrootvp' from the cache
 180          */
 181         uint32_t             mnt_generation;
 182         /*
 183          * if 'MNTK_AUTH_CACHE_TIMEOUT' is
 184          * set, then 'mnt_authcache_ttl' is
 185          * the time-to-live for the per-vnode authentication cache
 186          * on this mount... if zero, no cache is maintained...
 187          * if 'MNTK_AUTH_CACHE_TIMEOUT' isn't set, its the
 188          * time-to-live for the cached lookup right for
 189          * volumes marked 'MNTK_AUTH_OPAQUE'.
 190          */
 191         int             mnt_authcache_ttl;
 192         char            fstypename_override[MFSTYPENAMELEN];
 193 };
 194
 195 /*
 196  * default number of seconds to keep cached lookup
 197  * rights valid on mounts marked MNTK_AUTH_OPAQUE
 198  */
 199 #define CACHED_LOOKUP_RIGHT_TTL         2
 200
 201 /*
 202  * ioflags
 203  */
 204 #define MNT_IOFLAGS_FUA_SUPPORTED       0x00000001
 205 #define MNT_IOFLAGS_UNMAP_SUPPORTED     0x00000002
 206
 207 /*
 208  * ioqueue depth for devices that don't report one
 209  */
 210 #define MNT_DEFAULT_IOQUEUE_DEPTH       32
 211
 212
 213 /* XXX 3762912 hack to support HFS filesystem 'owner' */
 214 #define vfs_setowner(_mp, _uid, _gid)   do {(_mp)->mnt_fsowner = (_uid); (_mp)->mnt_fsgroup = (_gid); } while (0)
 215
 216
 217 /* mount point to which dead vps point to */
 218 extern struct mount * dead_mountp;
 219
 220 /*
 221  * Internal filesystem control flags stored in mnt_kern_flag.
 222  *
 223  * MNTK_UNMOUNT locks the mount entry so that name lookup cannot proceed
 224  * past the mount point.  This keeps the subtree stable during mounts
 225  * and unmounts.
 226  *
 227  * Note:        We are counting down on new bit assignments.  This is
 228  *              because the bits here were broken out from the high bits
 229  *              of the mount flags.
 230  */
 231 #define MNTK_DENY_READDIREXT 0x00000200 /* Deny Extended-style readdir's for this volume */
 232 #define MNTK_PERMIT_UNMOUNT     0x00000400      /* Allow (non-forced) unmounts by UIDs other than the one that mounted the volume */
 233 #ifdef NFSCLIENT
 234 #define MNTK_TYPENAME_OVERRIDE  0x00000800      /* override the fstypename for statfs() */
 235 #endif /* NFSCLIENT */
 236 #define MNTK_KERNEL_MOUNT       0x00001000      /* mount came from kernel side */
 237 #ifdef CONFIG_IMGSRC_ACCESS
 238 #define MNTK_HAS_MOVED          0x00002000
 239 #define MNTK_BACKS_ROOT         0x00004000
 240 #endif /* CONFIG_IMGSRC_ACCESS */
 241 #define MNTK_AUTH_CACHE_TTL     0x00008000      /* rights cache has TTL - TTL of 0 disables cache */
 242 #define MNTK_PATH_FROM_ID       0x00010000      /* mounted file system supports id-to-path lookups */
 243 #define MNTK_UNMOUNT_PREFLIGHT  0x00020000      /* mounted file system wants preflight check during unmount */
 244 #define MNTK_NAMED_STREAMS      0x00040000      /* mounted file system supports Named Streams VNOPs */
 245 #define MNTK_EXTENDED_ATTRS     0x00080000      /* mounted file system supports Extended Attributes VNOPs */
 246 #define MNTK_LOCK_LOCAL         0x00100000      /* advisory locking is done above the VFS itself */
 247 #define MNTK_VIRTUALDEV         0x00200000      /* mounted on a virtual device i.e. a disk image */
 248 #define MNTK_ROOTDEV            0x00400000      /* this filesystem resides on the same device as the root */
 249 #define MNTK_SSD                0x00800000      /* underlying device is of the solid state variety */
 250 #define MNTK_UNMOUNT            0x01000000      /* unmount in progress */
 251 #define MNTK_MWAIT              0x02000000      /* waiting for unmount to finish */
 252 #define MNTK_WANTRDWR           0x04000000      /* upgrade to read/write requested */
 253 #if REV_ENDIAN_FS
 254 #define MNT_REVEND              0x08000000      /* Reverse endian FS */
 255 #endif /* REV_ENDIAN_FS */
 256 #define MNTK_FRCUNMOUNT         0x10000000      /* Forced unmount wanted. */
 257 #define MNTK_AUTH_OPAQUE        0x20000000      /* authorisation decisions are not made locally */
 258 #define MNTK_AUTH_OPAQUE_ACCESS 0x40000000      /* VNOP_ACCESS is reliable for remote auth */
 259 #define MNTK_EXTENDED_SECURITY  0x80000000      /* extended security supported */
 260
 261 #define MNT_LNOTRESP            0x00000001      /* mount not responding */
 262 #define MNT_LUNMOUNT            0x00000002      /* mount in unmount */
 263 #define MNT_LFORCE              0x00000004      /* mount in forced unmount */
 264 #define MNT_LDRAIN              0x00000008      /* mount in drain */
 265 #define MNT_LITER               0x00000010      /* mount in iteration */
 266 #define MNT_LNEWVN              0x00000020      /* mount has new vnodes created */
 267 #define MNT_LWAIT               0x00000040      /* wait for unmount op */
 268 #define MNT_LITERWAIT           0x00000080      /* mount in iteration */
 269 #define MNT_LDEAD               0x00000100      /* mount already unmounted*/
 270
 271
 272 /*
 273  * Generic file handle
 274  */
 275 #define NFS_MAX_FH_SIZE         NFSV4_MAX_FH_SIZE
 276 #define NFSV4_MAX_FH_SIZE       128
 277 #define NFSV3_MAX_FH_SIZE       64
 278 #define NFSV2_MAX_FH_SIZE       32
 279 struct fhandle {
 280         int             fh_len;                         /* length of file handle */
 281         unsigned char   fh_data[NFS_MAX_FH_SIZE];       /* file handle value */
 282 };
 283 typedef struct fhandle  fhandle_t;
 284
 285
 286
 287 /*
 288  * Filesystem configuration information. One of these exists for each
 289  * type of filesystem supported by the kernel. These are searched at
 290  * mount time to identify the requested filesystem.
 291  */
 292 struct vfstable {
 293         struct  vfsops *vfc_vfsops;     /* filesystem operations vector */
 294         char    vfc_name[MFSNAMELEN];   /* filesystem type name */
 295         int     vfc_typenum;            /* historic filesystem type number */
 296         int     vfc_refcount;           /* number mounted of this type */
 297         int     vfc_flags;              /* permanent flags */
 298         int     (*vfc_mountroot)(mount_t, vnode_t, vfs_context_t);      /* if != NULL, routine to mount root */
 299         struct  vfstable *vfc_next;     /* next in list */
 300         int32_t vfc_reserved1;
 301         int32_t vfc_reserved2;
 302         int             vfc_vfsflags;   /* for optional types */
 303         void *          vfc_descptr;    /* desc table allocated address */
 304         int                     vfc_descsize;   /* size allocated for desc table */
 305 };
 306
 307 /* vfc_vfsflags: */
 308 #define VFC_VFSLOCALARGS        0x002
 309 #define VFC_VFSGENERICARGS      0x004
 310 #define VFC_VFSNATIVEXATTR      0x010
 311 #define VFC_VFSDIRLINKS         0x020
 312 #define VFC_VFSPREFLIGHT        0x040
 313 #define VFC_VFSREADDIR_EXTENDED 0x080
 314 #define VFC_VFS64BITREADY       0x100
 315 #define VFC_VFSNOMACLABEL       0x1000
 316 #define VFC_VFSVNOP_PAGEINV2    0x2000
 317 #define VFC_VFSVNOP_PAGEOUTV2   0x4000
 318 #define VFC_VFSVNOP_NOUPDATEID_RENAME   0x8000
 319
 320
 321 extern int maxvfsconf;          /* highest defined filesystem type */
 322 extern struct vfstable  *vfsconf;       /* head of list of filesystem types */
 323 extern int maxvfsslots;         /* Maximum slots available to be used */
 324 extern int numused_vfsslots;    /* number of slots already used */
 325
 326 /* the following two are xnu private */
 327 struct vfstable *       vfstable_add(struct     vfstable *);
 328 int     vfstable_del(struct vfstable *);
 329
 330
 331 struct vfsmount_args {
 332         union {
 333                 struct {
 334                         char * mnt_fspec;
 335                         void * mnt_fsdata;
 336                 } mnt_localfs_args;
 337                 struct {
 338                         void *  mnt_fsdata;             /* FS specific */
 339                 } mnt_remotefs_args;
 340         } mountfs_args;
 341 };
 342
 343
 344 /*
 345  * LP64 *user* version of statfs structure.
 346  * NOTE - must be kept in sync with struct statfs in mount.h
 347  */
 348 struct user64_statfs {
 349         short           f_otype;                /* TEMPORARY SHADOW COPY OF f_type */
 350         short           f_oflags;               /* TEMPORARY SHADOW COPY OF f_flags */
 351         user64_long_t   f_bsize;                /* fundamental file system block size */
 352         user64_long_t   f_iosize;               /* optimal transfer block size */
 353         user64_long_t   f_blocks;               /* total data blocks in file system */
 354         user64_long_t   f_bfree;                /* free blocks in fs */
 355         user64_long_t   f_bavail;               /* free blocks avail to non-superuser */
 356         user64_long_t   f_files;                /* total file nodes in file system */
 357         user64_long_t   f_ffree;                /* free file nodes in fs */
 358         fsid_t          f_fsid;                 /* file system id */
 359         uid_t           f_owner;                /* user that mounted the filesystem */
 360         short           f_reserved1;    /* spare for later */
 361         short           f_type;                 /* type of filesystem */
 362     user64_long_t       f_flags;                /* copy of mount exported flags */
 363         user64_long_t f_reserved2[2];   /* reserved for future use */
 364         char            f_fstypename[MFSNAMELEN]; /* fs type name */
 365         char            f_mntonname[MNAMELEN];  /* directory on which mounted */
 366         char            f_mntfromname[MNAMELEN];/* mounted filesystem */
 367         char            f_reserved3;    /* For alignment */
 368         user64_long_t   f_reserved4[4]; /* For future use */
 369 };
 370
 371 /*
 372  * ILP32 *user* version of statfs structure.
 373  * NOTE - must be kept in sync with struct statfs in mount.h
 374  */
 375 struct user32_statfs {
 376         short           f_otype;                /* TEMPORARY SHADOW COPY OF f_type */
 377         short           f_oflags;               /* TEMPORARY SHADOW COPY OF f_flags */
 378         user32_long_t   f_bsize;                /* fundamental file system block size */
 379         user32_long_t   f_iosize;               /* optimal transfer block size */
 380         user32_long_t   f_blocks;               /* total data blocks in file system */
 381         user32_long_t   f_bfree;                /* free blocks in fs */
 382         user32_long_t   f_bavail;               /* free blocks avail to non-superuser */
 383         user32_long_t   f_files;                /* total file nodes in file system */
 384         user32_long_t   f_ffree;                /* free file nodes in fs */
 385         fsid_t          f_fsid;                 /* file system id */
 386         uid_t           f_owner;                /* user that mounted the filesystem */
 387         short           f_reserved1;    /* spare for later */
 388         short           f_type;                 /* type of filesystem */
 389     user32_long_t       f_flags;                /* copy of mount exported flags */
 390         user32_long_t f_reserved2[2];   /* reserved for future use */
 391         char            f_fstypename[MFSNAMELEN]; /* fs type name */
 392         char            f_mntonname[MNAMELEN];  /* directory on which mounted */
 393         char            f_mntfromname[MNAMELEN];/* mounted filesystem */
 394         char            f_reserved3;    /* For alignment */
 395         user32_long_t   f_reserved4[4]; /* For future use */
 396 };
 397
 398 /*
 399  * throttle I/Os are affected only by normal I/Os happening on the same spindle.  Currently we use a 64-bit integer to
 400  * represent what devices are affected, so we can handle at most 64 different spindles.  Since
 401  * throttled I/O is usually useful in non-server environment only, this number is enough in most cases.
 402  */
 403 #define LOWPRI_MAX_NUM_DEV 64
 404
 405 __BEGIN_DECLS
 406
 407 extern uint32_t mount_generation;
 408 extern TAILQ_HEAD(mntlist, mount) mountlist;
 409 void mount_list_lock(void);
 410 void mount_list_unlock(void);
 411 void mount_lock_init(mount_t);
 412 void mount_lock_destroy(mount_t);
 413 void mount_lock(mount_t);
 414 void mount_lock_spin(mount_t);
 415 void mount_unlock(mount_t);
 416 void mount_lock_renames(mount_t);
 417 void mount_unlock_renames(mount_t);
 418 void mount_ref(mount_t, int);
 419 void mount_drop(mount_t, int);
 420 int  mount_refdrain(mount_t);
 421
 422 /* vfs_rootmountalloc should be kept as a private api */
 423 errno_t vfs_rootmountalloc(const char *, const char *, mount_t *mpp);
 424
 425 int     vfs_mountroot(void);
 426 void    vfs_unmountall(void);
 427 int     safedounmount(struct mount *, int, vfs_context_t);
 428 int     dounmount(struct mount *, int, int, vfs_context_t);
 429
 430 /* xnu internal api */
 431 void  mount_dropcrossref(mount_t, vnode_t, int);
 432 mount_t mount_lookupby_volfsid(int, int);
 433 mount_t mount_list_lookupby_fsid(fsid_t *, int, int);
 434 int  mount_list_add(mount_t);
 435 void mount_list_remove(mount_t);
 436 int  mount_iterref(mount_t, int);
 437 int  mount_isdrained(mount_t, int);
 438 void mount_iterdrop(mount_t);
 439 void mount_iterdrain(mount_t);
 440 void mount_iterreset(mount_t);
 441
 442 /* tags a volume as not supporting extended readdir for NFS exports */
 443 #ifdef BSD_KERNEL_PRIVATE
 444 void mount_set_noreaddirext (mount_t);
 445 #endif
 446
 447 /* Private NFS spi */
 448 #define KERNEL_MOUNT_NOAUTH             0x01 /* Don't check the UID of the directory we are mounting on */
 449 #define KERNEL_MOUNT_PERMIT_UNMOUNT     0x02 /* Allow (non-forced) unmounts by users other the one who mounted the volume */
 450 #if NFSCLIENT
 451 /*
 452  * NOTE: kernel_mount() does not force MNT_NOSUID, MNT_NOEXEC, or MNT_NODEC for non-privileged
 453  * mounting credentials, as the mount(2) system call does.
 454  */
 455 int kernel_mount(char *, vnode_t, vnode_t, const char *, void *, size_t, int, uint32_t, vfs_context_t);
 456 boolean_t vfs_iskernelmount(mount_t);
 457 #endif
 458
 459 /* throttled I/O api */
 460
 461 /* returned by throttle_io_will_be_throttled */
 462 #define THROTTLE_DISENGAGED     0
 463 #define THROTTLE_ENGAGED        1
 464 #define THROTTLE_NOW            2
 465
 466 int  throttle_get_io_policy(struct uthread **ut);
 467 int  throttle_get_passive_io_policy(struct uthread **ut);
 468 int  throttle_io_will_be_throttled(int lowpri_window_msecs, mount_t mp);
 469 void *throttle_info_update_by_mount(mount_t mp);
 470 void rethrottle_thread(uthread_t ut);
 471
 472 /* throttled I/O helper function */
 473 /* convert the lowest bit to a device index */
 474 extern int num_trailing_0(uint64_t n);
 475
 476 __END_DECLS
 477
 478 #endif /* !_SYS_MOUNT_INTERNAL_H_ */