xref: /xnu-11215/bsd/miscfs/devfs/devfs_vfsops.c (revision e6231be0)
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  * [email protected]
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 ([email protected]) 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
devfs_init(__unused struct vfsconf * vfsp)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_LOGD, GID_LOGD, 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
devfs_mount(struct mount * mp,__unused vnode_t devvp,__unused user_addr_t data,vfs_context_t ctx)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 	devfs_mp_p = kalloc_type(struct devfsmount,
194 	    Z_WAITOK | Z_ZERO | Z_NOFAIL);
195 	devfs_mp_p->mount = mp;
196 
197 	/*-
198 	 *  Fill out some fields
199 	 */
200 	__IGNORE_WCASTALIGN(mp->mnt_data = (qaddr_t)devfs_mp_p);
201 	mp->mnt_vfsstat.f_fsid.val[0] = (int32_t)VM_KERNEL_ADDRHASH(devfs_mp_p);
202 	mp->mnt_vfsstat.f_fsid.val[1] = vfs_typenum(mp);
203 	mp->mnt_flag |= MNT_LOCAL;
204 
205 	DEVFS_LOCK();
206 	error = dev_dup_plane(devfs_mp_p);
207 	DEVFS_UNLOCK();
208 
209 	if (error) {
210 		mp->mnt_data = (qaddr_t)0;
211 		kfree_type(struct devfsmount, devfs_mp_p);
212 		return error;
213 	} else {
214 		DEVFS_INCR_MOUNTS();
215 	}
216 
217 	/*-
218 	 *  Copy in the name of the directory the filesystem
219 	 *  is to be mounted on.
220 	 *  And we clear the remainder of the character strings
221 	 *  to be tidy.
222 	 */
223 
224 	bzero(mp->mnt_vfsstat.f_mntfromname, MAXPATHLEN);
225 	bcopy("devfs", mp->mnt_vfsstat.f_mntfromname, 5);
226 	(void)devfs_statfs(mp, &mp->mnt_vfsstat, ctx);
227 
228 	return 0;
229 }
230 
231 
232 static int
devfs_start(__unused struct mount * mp,__unused int flags,__unused vfs_context_t ctx)233 devfs_start(__unused struct mount *mp, __unused int flags, __unused vfs_context_t ctx)
234 {
235 	return 0;
236 }
237 
238 /*-
239  *  Unmount the filesystem described by mp.
240  */
241 static int
devfs_unmount(struct mount * mp,int mntflags,__unused vfs_context_t ctx)242 devfs_unmount( struct mount *mp, int mntflags, __unused vfs_context_t ctx)
243 {
244 	struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
245 	int flags = 0;
246 	int force = 0;
247 	int error;
248 
249 	if (mntflags & MNT_FORCE) {
250 		flags |= FORCECLOSE;
251 		force = 1;
252 	}
253 	error = vflush(mp, NULLVP, flags);
254 	if (error && !force) {
255 		return error;
256 	}
257 
258 	DEVFS_LOCK();
259 	devfs_free_plane(devfs_mp_p);
260 	DEVFS_UNLOCK();
261 
262 	DEVFS_DECR_MOUNTS();
263 
264 	kfree_type(struct devfsmount, devfs_mp_p);
265 	mp->mnt_data = (qaddr_t)0;
266 	mp->mnt_flag &= ~MNT_LOCAL;
267 
268 	return 0;
269 }
270 
271 /* return the address of the root vnode  in *vpp */
272 static int
devfs_root(struct mount * mp,struct vnode ** vpp,__unused vfs_context_t ctx)273 devfs_root(struct mount *mp, struct vnode **vpp, __unused vfs_context_t ctx)
274 {
275 	struct devfsmount *devfs_mp_p = (struct devfsmount *)(mp->mnt_data);
276 	int error;
277 
278 	DEVFS_LOCK();
279 	/* last parameter to devfs_dntovn() is ignored */
280 	error = devfs_dntovn(devfs_mp_p->plane_root->de_dnp, vpp, NULL);
281 	DEVFS_UNLOCK();
282 
283 	return error;
284 }
285 
286 static int
devfs_statfs(struct mount * mp,struct vfsstatfs * sbp,__unused vfs_context_t ctx)287 devfs_statfs( struct mount *mp, struct vfsstatfs *sbp, __unused vfs_context_t ctx)
288 {
289 	struct devfsmount *devfs_mp_p = (struct devfsmount *)mp->mnt_data;
290 
291 	/*-
292 	 *  Fill in the stat block.
293 	 */
294 	//sbp->f_type   = mp->mnt_vfsstat.f_type;
295 	sbp->f_flags  = 0;              /* XXX */
296 	sbp->f_bsize  = 512;
297 	sbp->f_iosize = 512;
298 	sbp->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
299 	    + devfs_stats.nodes * sizeof(devnode_t)
300 	    + devfs_stats.entries * sizeof(devdirent_t)
301 	    + devfs_stats.stringspace
302 	    ) / sbp->f_bsize;
303 	sbp->f_bfree  = 0;
304 	sbp->f_bavail = 0;
305 	sbp->f_files  = devfs_stats.nodes;
306 	sbp->f_ffree  = 0;
307 	sbp->f_fsid.val[0] = (int32_t)VM_KERNEL_ADDRHASH(devfs_mp_p);
308 	sbp->f_fsid.val[1] = vfs_typenum(mp);
309 
310 	return 0;
311 }
312 
313 static int
devfs_vfs_getattr(__unused mount_t mp,struct vfs_attr * fsap,__unused vfs_context_t ctx)314 devfs_vfs_getattr(__unused mount_t mp, struct vfs_attr *fsap, __unused vfs_context_t ctx)
315 {
316 	VFSATTR_RETURN(fsap, f_objcount, devfs_stats.nodes);
317 	VFSATTR_RETURN(fsap, f_maxobjcount, devfs_stats.nodes);
318 	VFSATTR_RETURN(fsap, f_bsize, 512);
319 	VFSATTR_RETURN(fsap, f_iosize, 512);
320 	if (VFSATTR_IS_ACTIVE(fsap, f_blocks) || VFSATTR_IS_ACTIVE(fsap, f_bused)) {
321 		fsap->f_blocks = (devfs_stats.mounts * sizeof(struct devfsmount)
322 		    + devfs_stats.nodes * sizeof(devnode_t)
323 		    + devfs_stats.entries * sizeof(devdirent_t)
324 		    + devfs_stats.stringspace
325 		    ) / fsap->f_bsize;
326 		fsap->f_bused = fsap->f_blocks;
327 		VFSATTR_SET_SUPPORTED(fsap, f_blocks);
328 		VFSATTR_SET_SUPPORTED(fsap, f_bused);
329 	}
330 	VFSATTR_RETURN(fsap, f_bfree, 0);
331 	VFSATTR_RETURN(fsap, f_bavail, 0);
332 	VFSATTR_RETURN(fsap, f_files, devfs_stats.nodes);
333 	VFSATTR_RETURN(fsap, f_ffree, 0);
334 	VFSATTR_RETURN(fsap, f_fssubtype, 0);
335 
336 	if (VFSATTR_IS_ACTIVE(fsap, f_capabilities)) {
337 		fsap->f_capabilities.capabilities[VOL_CAPABILITIES_FORMAT] =
338 		    VOL_CAP_FMT_SYMBOLICLINKS |
339 		    VOL_CAP_FMT_HARDLINKS |
340 		    VOL_CAP_FMT_NO_ROOT_TIMES |
341 		    VOL_CAP_FMT_CASE_SENSITIVE |
342 		    VOL_CAP_FMT_CASE_PRESERVING |
343 		    VOL_CAP_FMT_FAST_STATFS |
344 		    VOL_CAP_FMT_2TB_FILESIZE |
345 		    VOL_CAP_FMT_HIDDEN_FILES;
346 		fsap->f_capabilities.capabilities[VOL_CAPABILITIES_INTERFACES] =
347 		    VOL_CAP_INT_ATTRLIST;
348 		fsap->f_capabilities.capabilities[VOL_CAPABILITIES_RESERVED1] = 0;
349 		fsap->f_capabilities.capabilities[VOL_CAPABILITIES_RESERVED2] = 0;
350 
351 		fsap->f_capabilities.valid[VOL_CAPABILITIES_FORMAT] =
352 		    VOL_CAP_FMT_PERSISTENTOBJECTIDS |
353 		    VOL_CAP_FMT_SYMBOLICLINKS |
354 		    VOL_CAP_FMT_HARDLINKS |
355 		    VOL_CAP_FMT_JOURNAL |
356 		    VOL_CAP_FMT_JOURNAL_ACTIVE |
357 		    VOL_CAP_FMT_NO_ROOT_TIMES |
358 		    VOL_CAP_FMT_SPARSE_FILES |
359 		    VOL_CAP_FMT_ZERO_RUNS |
360 		    VOL_CAP_FMT_CASE_SENSITIVE |
361 		    VOL_CAP_FMT_CASE_PRESERVING |
362 		    VOL_CAP_FMT_FAST_STATFS |
363 		    VOL_CAP_FMT_2TB_FILESIZE |
364 		    VOL_CAP_FMT_OPENDENYMODES |
365 		    VOL_CAP_FMT_HIDDEN_FILES |
366 		    VOL_CAP_FMT_PATH_FROM_ID |
367 		    VOL_CAP_FMT_NO_VOLUME_SIZES;
368 		fsap->f_capabilities.valid[VOL_CAPABILITIES_INTERFACES] =
369 		    VOL_CAP_INT_SEARCHFS |
370 		    VOL_CAP_INT_ATTRLIST |
371 		    VOL_CAP_INT_NFSEXPORT |
372 		    VOL_CAP_INT_READDIRATTR |
373 		    VOL_CAP_INT_EXCHANGEDATA |
374 		    VOL_CAP_INT_COPYFILE |
375 		    VOL_CAP_INT_ALLOCATE |
376 		    VOL_CAP_INT_VOL_RENAME |
377 		    VOL_CAP_INT_ADVLOCK |
378 		    VOL_CAP_INT_FLOCK |
379 		    VOL_CAP_INT_EXTENDED_SECURITY |
380 		    VOL_CAP_INT_USERACCESS |
381 		    VOL_CAP_INT_MANLOCK |
382 		    VOL_CAP_INT_EXTENDED_ATTR |
383 		    VOL_CAP_INT_NAMEDSTREAMS;
384 		fsap->f_capabilities.valid[VOL_CAPABILITIES_RESERVED1] = 0;
385 		fsap->f_capabilities.valid[VOL_CAPABILITIES_RESERVED2] = 0;
386 
387 		VFSATTR_SET_SUPPORTED(fsap, f_capabilities);
388 	}
389 
390 	if (VFSATTR_IS_ACTIVE(fsap, f_attributes)) {
391 		fsap->f_attributes.validattr.commonattr =
392 		    ATTR_CMN_NAME | ATTR_CMN_DEVID | ATTR_CMN_FSID |
393 		    ATTR_CMN_OBJTYPE | ATTR_CMN_OBJTAG | ATTR_CMN_OBJID |
394 		    ATTR_CMN_PAROBJID |
395 		    ATTR_CMN_MODTIME | ATTR_CMN_CHGTIME | ATTR_CMN_ACCTIME |
396 		    ATTR_CMN_OWNERID | ATTR_CMN_GRPID | ATTR_CMN_ACCESSMASK |
397 		    ATTR_CMN_FLAGS | ATTR_CMN_USERACCESS | ATTR_CMN_FILEID;
398 		fsap->f_attributes.validattr.volattr =
399 		    ATTR_VOL_FSTYPE | ATTR_VOL_SIZE | ATTR_VOL_SPACEFREE |
400 		    ATTR_VOL_SPACEAVAIL | ATTR_VOL_MINALLOCATION |
401 		    ATTR_VOL_OBJCOUNT | ATTR_VOL_MAXOBJCOUNT |
402 		    ATTR_VOL_MOUNTPOINT | ATTR_VOL_MOUNTFLAGS |
403 		    ATTR_VOL_MOUNTEDDEVICE | ATTR_VOL_CAPABILITIES |
404 		    ATTR_VOL_ATTRIBUTES;
405 		fsap->f_attributes.validattr.dirattr =
406 		    ATTR_DIR_LINKCOUNT | ATTR_DIR_MOUNTSTATUS;
407 		fsap->f_attributes.validattr.fileattr =
408 		    ATTR_FILE_LINKCOUNT | ATTR_FILE_TOTALSIZE |
409 		    ATTR_FILE_IOBLOCKSIZE | ATTR_FILE_DEVTYPE |
410 		    ATTR_FILE_DATALENGTH;
411 		fsap->f_attributes.validattr.forkattr = 0;
412 
413 		fsap->f_attributes.nativeattr.commonattr =
414 		    ATTR_CMN_NAME | ATTR_CMN_DEVID | ATTR_CMN_FSID |
415 		    ATTR_CMN_OBJTYPE | ATTR_CMN_OBJTAG | ATTR_CMN_OBJID |
416 		    ATTR_CMN_PAROBJID |
417 		    ATTR_CMN_MODTIME | ATTR_CMN_CHGTIME | ATTR_CMN_ACCTIME |
418 		    ATTR_CMN_OWNERID | ATTR_CMN_GRPID | ATTR_CMN_ACCESSMASK |
419 		    ATTR_CMN_FLAGS | ATTR_CMN_USERACCESS | ATTR_CMN_FILEID;
420 		fsap->f_attributes.nativeattr.volattr =
421 		    ATTR_VOL_FSTYPE | ATTR_VOL_SIZE | ATTR_VOL_SPACEFREE |
422 		    ATTR_VOL_SPACEAVAIL | ATTR_VOL_MINALLOCATION |
423 		    ATTR_VOL_OBJCOUNT | ATTR_VOL_MAXOBJCOUNT |
424 		    ATTR_VOL_MOUNTPOINT | ATTR_VOL_MOUNTFLAGS |
425 		    ATTR_VOL_MOUNTEDDEVICE | ATTR_VOL_CAPABILITIES |
426 		    ATTR_VOL_ATTRIBUTES;
427 		fsap->f_attributes.nativeattr.dirattr =
428 		    ATTR_DIR_MOUNTSTATUS;
429 		fsap->f_attributes.nativeattr.fileattr =
430 		    ATTR_FILE_LINKCOUNT | ATTR_FILE_TOTALSIZE |
431 		    ATTR_FILE_IOBLOCKSIZE | ATTR_FILE_DEVTYPE |
432 		    ATTR_FILE_DATALENGTH;
433 		fsap->f_attributes.nativeattr.forkattr = 0;
434 
435 		VFSATTR_SET_SUPPORTED(fsap, f_attributes);
436 	}
437 
438 	return 0;
439 }
440 
441 static int
devfs_sync(__unused struct mount * mp,__unused int waitfor,__unused vfs_context_t ctx)442 devfs_sync(__unused struct mount *mp, __unused int waitfor, __unused vfs_context_t ctx)
443 {
444 	return 0;
445 }
446 
447 
448 static int
devfs_vget(__unused struct mount * mp,__unused ino64_t ino,__unused struct vnode ** vpp,__unused vfs_context_t ctx)449 devfs_vget(__unused struct mount *mp, __unused ino64_t ino, __unused struct vnode **vpp, __unused vfs_context_t ctx)
450 {
451 	return ENOTSUP;
452 }
453 
454 /*************************************************************
455  * The concept of exporting a kernel generated devfs is stupid
456  * So don't handle filehandles
457  */
458 
459 static int
devfs_fhtovp(__unused struct mount * mp,__unused int fhlen,__unused unsigned char * fhp,__unused struct vnode ** vpp,__unused vfs_context_t ctx)460 devfs_fhtovp(__unused struct mount *mp, __unused int fhlen, __unused unsigned char *fhp, __unused struct vnode **vpp, __unused vfs_context_t ctx)
461 {
462 	return EINVAL;
463 }
464 
465 
466 static int
devfs_vptofh(__unused struct vnode * vp,__unused int * fhlenp,__unused unsigned char * fhp,__unused vfs_context_t ctx)467 devfs_vptofh(__unused struct vnode *vp, __unused int *fhlenp, __unused unsigned char *fhp, __unused vfs_context_t ctx)
468 {
469 	return EINVAL;
470 }
471 
472 static int
devfs_sysctl(__unused int * name,__unused u_int namelen,__unused user_addr_t oldp,__unused size_t * oldlenp,__unused user_addr_t newp,__unused size_t newlen,__unused vfs_context_t ctx)473 devfs_sysctl(__unused int *name, __unused u_int namelen, __unused user_addr_t oldp,
474     __unused size_t *oldlenp, __unused user_addr_t newp,
475     __unused size_t newlen, __unused vfs_context_t ctx)
476 {
477 	return ENOTSUP;
478 }
479 
480 #include <sys/namei.h>
481 
482 /*
483  * Function: devfs_kernel_mount
484  * Purpose:
485  *   Mount devfs at the given mount point from within the kernel.
486  */
487 int
devfs_kernel_mount(char * mntname)488 devfs_kernel_mount(char * mntname)
489 {
490 	int error;
491 	vfs_context_t ctx = vfs_context_kernel();
492 	char fsname[] = "devfs";
493 
494 	error = kernel_mount(fsname, NULLVP, NULLVP, mntname, NULL, 0, MNT_DONTBROWSE, KERNEL_MOUNT_NOAUTH | KERNEL_MOUNT_DEVFS, ctx);
495 	if (error) {
496 		printf("devfs_kernel_mount: kernel_mount failed: %d\n", error);
497 		return error;
498 	}
499 
500 	return 0;
501 }
502 
503 const struct vfsops devfs_vfsops = {
504 	.vfs_mount   = devfs_mount,
505 	.vfs_start   = devfs_start,
506 	.vfs_unmount = devfs_unmount,
507 	.vfs_root    = devfs_root,
508 	.vfs_getattr = devfs_vfs_getattr,
509 	.vfs_sync    = devfs_sync,
510 	.vfs_vget    = devfs_vget,
511 	.vfs_fhtovp  = devfs_fhtovp,
512 	.vfs_vptofh  = devfs_vptofh,
513 	.vfs_init    = devfs_init,
514 	.vfs_sysctl  = devfs_sysctl,
515 	// There are other VFS ops that we do not support
516 };
517