bsd/miscfs/devfs/devfs_vfsops.c

   1 /*
   2  * Copyright (c) 2000-2010 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 /*-
  29  * Copyright 1997,1998 Julian Elischer.  All rights reserved.
  30  * julian@freebsd.org
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions are
  34  * met:
  35  *  1. Redistributions of source code must retain the above copyright
  36  *     notice, this list of conditions and the following disclaimer.
  37  *  2. Redistributions in binary form must reproduce the above copyright notice,
  38  *     this list of conditions and the following disclaimer in the documentation
  39  *     and/or other materials provided with the distribution.
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``AS IS'' AND ANY EXPRESS
  42  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  43  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  44  * DISCLAIMED.  IN NO EVENT SHALL THE HOLDER OR CONTRIBUTORS BE LIABLE FOR
  45  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  47  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  48  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * devfs_vfsops.c
  54  *
  55  */
  56 /*
  57  * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce
  58  * support for mandatory and extensible security protections.  This notice
  59  * is included in support of clause 2.2 (b) of the Apple Public License,
  60  * Version 2.0.
  61  */
  62 /*
  63  * HISTORY
  64  *  Dieter Siegmund (dieter@apple.com) Wed Jul 14 13:37:59 PDT 1999
  65  *  - modified devfs_statfs() to use devfs_stats to calculate the
  66  *    amount of memory used by devfs
  67  */
  68
  69
  70 #include <sys/param.h>
  71 #include <sys/systm.h>
  72 #include <sys/kernel.h>
  73 #include <sys/vnode_internal.h>
  74 #include <sys/proc.h>
  75 #include <sys/kauth.h>
  76 #include <sys/mount_internal.h>
  77 #include <sys/malloc.h>
  78 #include <sys/conf.h>
  79 #include <libkern/OSAtomic.h>
  80 #include <atm/atm_internal.h>
  81
  82 #if CONFIG_MACF
  83 #include <security/mac_framework.h>
  84 #endif
  85
  86 #include "devfs.h"
  87 #include "devfsdefs.h"
  88
  89 #if FDESC
  90 #include "fdesc.h"
  91 #endif /* FDESC */
  92
  93
  94 static int devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, vfs_context_t ctx);
  95 static int devfs_vfs_getattr(mount_t mp, struct vfs_attr *fsap, vfs_context_t ctx);
  96
  97 #if CONFIG_DEV_KMEM
  98 extern boolean_t dev_kmem_enabled;
  99 #endif
 100
 101 /*-
 102  * Called from the generic VFS startups.
 103  * This is the second stage of DEVFS initialisation.
 104  * The probed devices have already been loaded and the
 105  * basic structure of the DEVFS created.
 106  * We take the oportunity to mount the hidden DEVFS layer, so that
 107  * devices from devfs get sync'd.
 108  */
 109 static int
 110 devfs_init(__unused struct vfsconf *vfsp)
 111 {
 112         if (devfs_sinit()) {
 113                 return ENOTSUP;
 114         }
 115         devfs_make_node(makedev(0, 0), DEVFS_CHAR,
 116             UID_ROOT, GID_WHEEL, 0622, "console");
 117         devfs_make_node(makedev(2, 0), DEVFS_CHAR,
 118             UID_ROOT, GID_WHEEL, 0666, "tty");
 119 #if CONFIG_DEV_KMEM
 120         if (dev_kmem_enabled) {
 121                 /* (3,0) reserved for /dev/mem physical memory */
 122                 devfs_make_node(makedev(3, 1), DEVFS_CHAR,
 123                     UID_ROOT, GID_KMEM, 0640, "kmem");
 124         }
 125 #endif
 126         devfs_make_node(makedev(3, 2), DEVFS_CHAR,
 127             UID_ROOT, GID_WHEEL, 0666, "null");
 128         devfs_make_node(makedev(3, 3), DEVFS_CHAR,
 129             UID_ROOT, GID_WHEEL, 0666, "zero");
 130         uint32_t logging_config = atm_get_diagnostic_config();
 131
 132         devfs_make_node(makedev(6, 0), DEVFS_CHAR,
 133             UID_ROOT, GID_WHEEL, 0600, "klog");
 134
 135         if (!(logging_config & ATM_TRACE_DISABLE)) {
 136                 devfs_make_node(makedev(7, 0), DEVFS_CHAR,
 137                     UID_ROOT, GID_WHEEL, 0600, "oslog");
 138                 if (cdevsw_setkqueueok(7, (&(cdevsw[7])), 0) == -1) {
 139                         return ENOTSUP;
 140                 }
 141
 142                 devfs_make_node(makedev(8, 0), DEVFS_CHAR,
 143                     UID_ROOT, GID_WHEEL, 0600, "oslog_stream");
 144                 if (cdevsw_setkqueueok(8, (&(cdevsw[8])), 0) == -1) {
 145                         return ENOTSUP;
 146                 }
 147         }
 148
 149
 150 #if  FDESC
 151         devfs_fdesc_init();
 152 #endif
 153
 154         return 0;
 155 }
 156
 157 /*-
 158  *  mp   - pointer to 'mount' structure
 159  *  path - addr in user space of mount point (ie /usr or whatever)
 160  *  data - addr in user space of mount params including the
 161  *         name of the block special file to treat as a filesystem.
 162  *         (NOT USED)
 163  *  ndp  - namei data pointer (NOT USED)
 164  *  p    - proc pointer
 165  * devfs is special in that it doesn't require any device to be mounted..
 166  * It makes up its data as it goes along.
 167  * it must be mounted during single user.. until it is, only std{in/out/err}
 168  * and the root filesystem are available.
 169  */
 170 /*proto*/
 171 int
 172 devfs_mount(struct mount *mp, __unused vnode_t devvp, __unused user_addr_t data, vfs_context_t ctx)
 173 {
 174         struct devfsmount *devfs_mp_p;  /* devfs specific mount info */
 175         int error;
 176
 177         /*-
 178          *  If they just want to update, we don't need to do anything.
 179          */
 180         if (mp->mnt_flag & MNT_UPDATE) {
 181                 return 0;
 182         }
 183
 184         /* Advisory locking should be handled at the VFS layer */
 185         vfs_setlocklocal(mp);
 186
 187         /*-
 188          *  Well, it's not an update, it's a real mount request.
 189          *  Time to get dirty.
 190          * HERE we should check to see if we are already mounted here.
 191          */
 192
 193         MALLOC(devfs_mp_p, struct devfsmount *, sizeof(struct devfsmount),
 194             M_DEVFSMNT, M_WAITOK);
 195         if (devfs_mp_p == NULL) {
 196                 return ENOMEM;
 197         }
 198         bzero(devfs_mp_p, sizeof(*devfs_mp_p));
 199         devfs_mp_p->mount = mp;
 200
 201         /*-
 202          *  Fill out some fields
 203          */
 204         __IGNORE_WCASTALIGN(mp->mnt_data = (qaddr_t)devfs_mp_p);
 205         mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)VM_KERNEL_ADDRHASH(devfs_mp_p);
 206         mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
 207         mp->mnt_flag |= MNT_LOCAL;
 208
 209         DEVFS_LOCK();
 210         error = dev_dup_plane(devfs_mp_p);
 211         DEVFS_UNLOCK();
 212
 213         if (error) {
 214                 mp->mnt_data = (qaddr_t)0;
 215                 FREE(devfs_mp_p, M_DEVFSMNT);
 216                 return error;
 217         } else {
 218                 DEVFS_INCR_MOUNTS();
 219         }
 220
 221         /*-
 222          *  Copy in the name of the directory the filesystem
 223          *  is to be mounted on.
 224          *  And we clear the remainder of the character strings
 225          *  to be tidy.
 226          */
 227
 228         bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
 229         bcopy("devfs", mp->mnt_vfsstat.f_mntfromname, 5);
 230         (void)devfs_statfs(mp, &mp->mnt_vfsstat, ctx);
 231
 232         return 0;
 233 }
 234
 235
 236 static int
 237 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t ctx)
 238 {
 239         return 0;
 240 }
 241
 242 /*-
 243  *  Unmount the filesystem described by mp.
 244  */
 245 static int
 246 devfs_unmount( struct mount *mp, int mntflags, __unused vfs_context_t ctx)
 247 {
 248         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 249         int flags = 0;
 250         int force = 0;
 251         int error;
 252
 253         if (mntflags & MNT_FORCE) {
 254                 flags |= FORCECLOSE;
 255                 force = 1;
 256         }
 257         error = vflush(mp, NULLVP, flags);
 258         if (error && !force) {
 259                 return error;
 260         }
 261
 262         DEVFS_LOCK();
 263         devfs_free_plane(devfs_mp_p);
 264         DEVFS_UNLOCK();
 265
 266         DEVFS_DECR_MOUNTS();
 267
 268         FREE(devfs_mp_p, M_DEVFSMNT);
 269         mp->mnt_data = (qaddr_t)0;
 270         mp->mnt_flag &= ~MNT_LOCAL;
 271
 272         return 0;
 273 }
 274
 275 /* return the address of the root vnode  in *vpp */
 276 static int
 277 devfs_root(struct mount *mp, struct vnode **vpp, __unused vfs_context_t ctx)
 278 {
 279         struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
 280         int error;
 281
 282         DEVFS_LOCK();
 283         /* last parameter to devfs_dntovn() is ignored */
 284         error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, NULL);
 285         DEVFS_UNLOCK();
 286
 287         return error;
 288 }
 289
 290 static int
 291 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t ctx)
 292 {
 293         struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
 294
 295         /*-
 296          *  Fill in the stat block.
 297          */
 298         //sbp->f_type   = mp->mnt_vfsstat.f_type;
 299         sbp->f_flags  = 0;              /* XXX */
 300         sbp->f_bsize  = 512;
 301         sbp->f_iosize = 512;
 302         sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 303             + devfs_stats.nodes * sizeof(devnode_t)
 304             + devfs_stats.entries * sizeof(devdirent_t)
 305             + devfs_stats.stringspace
 306             ) / sbp->f_bsize;
 307         sbp->f_bfree  = 0;
 308         sbp->f_bavail = 0;
 309         sbp->f_files  = devfs_stats.nodes;
 310         sbp->f_ffree  = 0;
 311         sbp->f_fsid.val[0] = (int32_t)VM_KERNEL_ADDRHASH(devfs_mp_p);
 312         sbp->f_fsid.val[1] = vfs_typenum(mp);
 313
 314         return 0;
 315 }
 316
 317 static int
 318 devfs_vfs_getattr(__unused mount_t mp, struct vfs_attr *fsap, __unused vfs_context_t ctx)
 319 {
 320         VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
 321         VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
 322         VFSATTR_RETURN(fsap, f_bsize, 512);
 323         VFSATTR_RETURN(fsap, f_iosize, 512);
 324         if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
 325                 fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
 326                     + devfs_stats.nodes * sizeof(devnode_t)
 327                     + devfs_stats.entries * sizeof(devdirent_t)
 328                     + devfs_stats.stringspace
 329                     ) / fsap->f_bsize;
 330                 fsap->f_bused = fsap->f_blocks;
 331                 VFSATTR_SET_SUPPORTED(fsap, f_blocks);
 332                 VFSATTR_SET_SUPPORTED(fsap, f_bused);
 333         }
 334         VFSATTR_RETURN(fsap, f_bfree, 0);
 335         VFSATTR_RETURN(fsap, f_bavail, 0);
 336         VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
 337         VFSATTR_RETURN(fsap, f_ffree, 0);
 338         VFSATTR_RETURN(fsap, f_fssubtype, 0);
 339
 340         if (VFSATTR_IS_ACTIVE(fsap, f_capabilities)) {
 341                 fsap->f_capabilities.capabilities[VOL_CAPABILITIES_FORMAT] =
 342                     VOL_CAP_FMT_SYMBOLICLINKS |
 343                     VOL_CAP_FMT_HARDLINKS |
 344                     VOL_CAP_FMT_NO_ROOT_TIMES |
 345                     VOL_CAP_FMT_CASE_SENSITIVE |
 346                     VOL_CAP_FMT_CASE_PRESERVING |
 347                     VOL_CAP_FMT_FAST_STATFS |
 348                     VOL_CAP_FMT_2TB_FILESIZE |
 349                     VOL_CAP_FMT_HIDDEN_FILES;
 350                 fsap->f_capabilities.capabilities[VOL_CAPABILITIES_INTERFACES] =
 351                     VOL_CAP_INT_ATTRLIST;
 352                 fsap->f_capabilities.capabilities[VOL_CAPABILITIES_RESERVED1] = 0;
 353                 fsap->f_capabilities.capabilities[VOL_CAPABILITIES_RESERVED2] = 0;
 354
 355                 fsap->f_capabilities.valid[VOL_CAPABILITIES_FORMAT] =
 356                     VOL_CAP_FMT_PERSISTENTOBJECTIDS |
 357                     VOL_CAP_FMT_SYMBOLICLINKS |
 358                     VOL_CAP_FMT_HARDLINKS |
 359                     VOL_CAP_FMT_JOURNAL |
 360                     VOL_CAP_FMT_JOURNAL_ACTIVE |
 361                     VOL_CAP_FMT_NO_ROOT_TIMES |
 362                     VOL_CAP_FMT_SPARSE_FILES |
 363                     VOL_CAP_FMT_ZERO_RUNS |
 364                     VOL_CAP_FMT_CASE_SENSITIVE |
 365                     VOL_CAP_FMT_CASE_PRESERVING |
 366                     VOL_CAP_FMT_FAST_STATFS |
 367                     VOL_CAP_FMT_2TB_FILESIZE |
 368                     VOL_CAP_FMT_OPENDENYMODES |
 369                     VOL_CAP_FMT_HIDDEN_FILES |
 370                     VOL_CAP_FMT_PATH_FROM_ID |
 371                     VOL_CAP_FMT_NO_VOLUME_SIZES;
 372                 fsap->f_capabilities.valid[VOL_CAPABILITIES_INTERFACES] =
 373                     VOL_CAP_INT_SEARCHFS |
 374                     VOL_CAP_INT_ATTRLIST |
 375                     VOL_CAP_INT_NFSEXPORT |
 376                     VOL_CAP_INT_READDIRATTR |
 377                     VOL_CAP_INT_EXCHANGEDATA |
 378                     VOL_CAP_INT_COPYFILE |
 379                     VOL_CAP_INT_ALLOCATE |
 380                     VOL_CAP_INT_VOL_RENAME |
 381                     VOL_CAP_INT_ADVLOCK |
 382                     VOL_CAP_INT_FLOCK |
 383                     VOL_CAP_INT_EXTENDED_SECURITY |
 384                     VOL_CAP_INT_USERACCESS |
 385                     VOL_CAP_INT_MANLOCK |
 386                     VOL_CAP_INT_EXTENDED_ATTR |
 387                     VOL_CAP_INT_NAMEDSTREAMS;
 388                 fsap->f_capabilities.valid[VOL_CAPABILITIES_RESERVED1] = 0;
 389                 fsap->f_capabilities.valid[VOL_CAPABILITIES_RESERVED2] = 0;
 390
 391                 VFSATTR_SET_SUPPORTED(fsap, f_capabilities);
 392         }
 393
 394         if (VFSATTR_IS_ACTIVE(fsap, f_attributes)) {
 395                 fsap->f_attributes.validattr.commonattr =
 396                     ATTR_CMN_NAME | ATTR_CMN_DEVID | ATTR_CMN_FSID |
 397                     ATTR_CMN_OBJTYPE | ATTR_CMN_OBJTAG | ATTR_CMN_OBJID |
 398                     ATTR_CMN_PAROBJID |
 399                     ATTR_CMN_MODTIME | ATTR_CMN_CHGTIME | ATTR_CMN_ACCTIME |
 400                     ATTR_CMN_OWNERID | ATTR_CMN_GRPID | ATTR_CMN_ACCESSMASK |
 401                     ATTR_CMN_FLAGS | ATTR_CMN_USERACCESS | ATTR_CMN_FILEID;
 402                 fsap->f_attributes.validattr.volattr =
 403                     ATTR_VOL_FSTYPE | ATTR_VOL_SIZE | ATTR_VOL_SPACEFREE |
 404                     ATTR_VOL_SPACEAVAIL | ATTR_VOL_MINALLOCATION |
 405                     ATTR_VOL_OBJCOUNT | ATTR_VOL_MAXOBJCOUNT |
 406                     ATTR_VOL_MOUNTPOINT | ATTR_VOL_MOUNTFLAGS |
 407                     ATTR_VOL_MOUNTEDDEVICE | ATTR_VOL_CAPABILITIES |
 408                     ATTR_VOL_ATTRIBUTES;
 409                 fsap->f_attributes.validattr.dirattr =
 410                     ATTR_DIR_LINKCOUNT | ATTR_DIR_MOUNTSTATUS;
 411                 fsap->f_attributes.validattr.fileattr =
 412                     ATTR_FILE_LINKCOUNT | ATTR_FILE_TOTALSIZE |
 413                     ATTR_FILE_IOBLOCKSIZE | ATTR_FILE_DEVTYPE |
 414                     ATTR_FILE_DATALENGTH;
 415                 fsap->f_attributes.validattr.forkattr = 0;
 416
 417                 fsap->f_attributes.nativeattr.commonattr =
 418                     ATTR_CMN_NAME | ATTR_CMN_DEVID | ATTR_CMN_FSID |
 419                     ATTR_CMN_OBJTYPE | ATTR_CMN_OBJTAG | ATTR_CMN_OBJID |
 420                     ATTR_CMN_PAROBJID |
 421                     ATTR_CMN_MODTIME | ATTR_CMN_CHGTIME | ATTR_CMN_ACCTIME |
 422                     ATTR_CMN_OWNERID | ATTR_CMN_GRPID | ATTR_CMN_ACCESSMASK |
 423                     ATTR_CMN_FLAGS | ATTR_CMN_USERACCESS | ATTR_CMN_FILEID;
 424                 fsap->f_attributes.nativeattr.volattr =
 425                     ATTR_VOL_FSTYPE | ATTR_VOL_SIZE | ATTR_VOL_SPACEFREE |
 426                     ATTR_VOL_SPACEAVAIL | ATTR_VOL_MINALLOCATION |
 427                     ATTR_VOL_OBJCOUNT | ATTR_VOL_MAXOBJCOUNT |
 428                     ATTR_VOL_MOUNTPOINT | ATTR_VOL_MOUNTFLAGS |
 429                     ATTR_VOL_MOUNTEDDEVICE | ATTR_VOL_CAPABILITIES |
 430                     ATTR_VOL_ATTRIBUTES;
 431                 fsap->f_attributes.nativeattr.dirattr =
 432                     ATTR_DIR_MOUNTSTATUS;
 433                 fsap->f_attributes.nativeattr.fileattr =
 434                     ATTR_FILE_LINKCOUNT | ATTR_FILE_TOTALSIZE |
 435                     ATTR_FILE_IOBLOCKSIZE | ATTR_FILE_DEVTYPE |
 436                     ATTR_FILE_DATALENGTH;
 437                 fsap->f_attributes.nativeattr.forkattr = 0;
 438
 439                 VFSATTR_SET_SUPPORTED(fsap, f_attributes);
 440         }
 441
 442         return 0;
 443 }
 444
 445 static int
 446 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t ctx)
 447 {
 448         return 0;
 449 }
 450
 451
 452 static int
 453 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t ctx)
 454 {
 455         return ENOTSUP;
 456 }
 457
 458 /*************************************************************
 459  * The concept of exporting a kernel generated devfs is stupid
 460  * So don't handle filehandles
 461  */
 462
 463 static int
 464 devfs_fhtovp(__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t ctx)
 465 {
 466         return EINVAL;
 467 }
 468
 469
 470 static int
 471 devfs_vptofh(__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t ctx)
 472 {
 473         return EINVAL;
 474 }
 475
 476 static int
 477 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
 478     __unused size_t *oldlenp, __unused user_addr_t newp,
 479     __unused size_t newlen, __unused vfs_context_t ctx)
 480 {
 481         return ENOTSUP;
 482 }
 483
 484 #include <sys/namei.h>
 485
 486 /*
 487  * Function: devfs_kernel_mount
 488  * Purpose:
 489  *   Mount devfs at the given mount point from within the kernel.
 490  */
 491 int
 492 devfs_kernel_mount(char * mntname)
 493 {
 494         int error;
 495         vfs_context_t ctx = vfs_context_kernel();
 496         char fsname[] = "devfs";
 497
 498         error = kernel_mount(fsname, NULLVP, NULLVP, mntname, NULL, 0, MNT_DONTBROWSE, KERNEL_MOUNT_NOAUTH, ctx);
 499         if (error) {
 500                 printf("devfs_kernel_mount: kernel_mount failed: %d\n", error);
 501                 return error;
 502         }
 503
 504         return 0;
 505 }
 506
 507 const struct vfsops devfs_vfsops = {
 508         .vfs_mount   = devfs_mount,
 509         .vfs_start   = devfs_start,
 510         .vfs_unmount = devfs_unmount,
 511         .vfs_root    = devfs_root,
 512         .vfs_getattr = devfs_vfs_getattr,
 513         .vfs_sync    = devfs_sync,
 514         .vfs_vget    = devfs_vget,
 515         .vfs_fhtovp  = devfs_fhtovp,
 516         .vfs_vptofh  = devfs_vptofh,
 517         .vfs_init    = devfs_init,
 518         .vfs_sysctl  = devfs_sysctl,
 519         // There are other VFS ops that we do not support
 520 };