xref: /dragonfly/sys/kern/vfs_syscalls.c (revision bc3d4063)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)vfs_syscalls.c	8.13 (Berkeley) 4/15/94
39  * $FreeBSD: src/sys/kern/vfs_syscalls.c,v 1.151.2.18 2003/04/04 20:35:58 tegge Exp $
40  * $DragonFly: src/sys/kern/vfs_syscalls.c,v 1.133 2008/06/28 17:59:49 dillon Exp $
41  */
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/buf.h>
46 #include <sys/conf.h>
47 #include <sys/sysent.h>
48 #include <sys/malloc.h>
49 #include <sys/mount.h>
50 #include <sys/mountctl.h>
51 #include <sys/sysproto.h>
52 #include <sys/filedesc.h>
53 #include <sys/kernel.h>
54 #include <sys/fcntl.h>
55 #include <sys/file.h>
56 #include <sys/linker.h>
57 #include <sys/stat.h>
58 #include <sys/unistd.h>
59 #include <sys/vnode.h>
60 #include <sys/proc.h>
61 #include <sys/namei.h>
62 #include <sys/nlookup.h>
63 #include <sys/dirent.h>
64 #include <sys/extattr.h>
65 #include <sys/spinlock.h>
66 #include <sys/kern_syscall.h>
67 #include <sys/objcache.h>
68 #include <sys/sysctl.h>
69 
70 #include <sys/buf2.h>
71 #include <sys/file2.h>
72 #include <sys/spinlock2.h>
73 
74 #include <vm/vm.h>
75 #include <vm/vm_object.h>
76 #include <vm/vm_page.h>
77 
78 #include <machine/limits.h>
79 #include <machine/stdarg.h>
80 
81 #include <vfs/union/union.h>
82 
83 static void mount_warning(struct mount *mp, const char *ctl, ...);
84 static int mount_path(struct proc *p, struct mount *mp, char **rb, char **fb);
85 static int checkvp_chdir (struct vnode *vn, struct thread *td);
86 static void checkdirs (struct nchandle *old_nch, struct nchandle *new_nch);
87 static int chroot_refuse_vdir_fds (struct filedesc *fdp);
88 static int chroot_visible_mnt(struct mount *mp, struct proc *p);
89 static int getutimes (const struct timeval *, struct timespec *);
90 static int setfown (struct vnode *, uid_t, gid_t);
91 static int setfmode (struct vnode *, int);
92 static int setfflags (struct vnode *, int);
93 static int setutimes (struct vnode *, const struct timespec *, int);
94 static int	usermount = 0;	/* if 1, non-root can mount fs. */
95 
96 int (*union_dircheckp) (struct thread *, struct vnode **, struct file *);
97 
98 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0, "");
99 
100 /*
101  * Virtual File System System Calls
102  */
103 
104 /*
105  * Mount a file system.
106  */
107 /*
108  * mount_args(char *type, char *path, int flags, caddr_t data)
109  */
110 /* ARGSUSED */
111 int
112 sys_mount(struct mount_args *uap)
113 {
114 	struct thread *td = curthread;
115 	struct proc *p = td->td_proc;
116 	struct vnode *vp;
117 	struct nchandle nch;
118 	struct mount *mp;
119 	struct vfsconf *vfsp;
120 	int error, flag = 0, flag2 = 0;
121 	int hasmount;
122 	struct vattr va;
123 	struct nlookupdata nd;
124 	char fstypename[MFSNAMELEN];
125 	struct ucred *cred = p->p_ucred;
126 
127 	KKASSERT(p);
128 	if (cred->cr_prison != NULL)
129 		return (EPERM);
130 	if (usermount == 0 && (error = suser(td)))
131 		return (error);
132 	/*
133 	 * Do not allow NFS export by non-root users.
134 	 */
135 	if (uap->flags & MNT_EXPORTED) {
136 		error = suser(td);
137 		if (error)
138 			return (error);
139 	}
140 	/*
141 	 * Silently enforce MNT_NOSUID and MNT_NODEV for non-root users
142 	 */
143 	if (suser(td))
144 		uap->flags |= MNT_NOSUID | MNT_NODEV;
145 
146 	/*
147 	 * Lookup the requested path and extract the nch and vnode.
148 	 */
149 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
150 	if (error == 0) {
151 		if ((error = nlookup(&nd)) == 0) {
152 			if (nd.nl_nch.ncp->nc_vp == NULL)
153 				error = ENOENT;
154 		}
155 	}
156 	if (error) {
157 		nlookup_done(&nd);
158 		return (error);
159 	}
160 
161 	/*
162 	 * Extract the locked+refd ncp and cleanup the nd structure
163 	 */
164 	nch = nd.nl_nch;
165 	cache_zero(&nd.nl_nch);
166 	nlookup_done(&nd);
167 
168 	if ((nch.ncp->nc_flag & NCF_ISMOUNTPT) && cache_findmount(&nch))
169 		hasmount = 1;
170 	else
171 		hasmount = 0;
172 
173 
174 	/*
175 	 * now we have the locked ref'd nch and unreferenced vnode.
176 	 */
177 	vp = nch.ncp->nc_vp;
178 	if ((error = vget(vp, LK_EXCLUSIVE)) != 0) {
179 		cache_put(&nch);
180 		return (error);
181 	}
182 	cache_unlock(&nch);
183 
184 	/*
185 	 * Now we have an unlocked ref'd nch and a locked ref'd vp
186 	 */
187 	if (uap->flags & MNT_UPDATE) {
188 		if ((vp->v_flag & VROOT) == 0) {
189 			cache_drop(&nch);
190 			vput(vp);
191 			return (EINVAL);
192 		}
193 		mp = vp->v_mount;
194 		flag = mp->mnt_flag;
195 		flag2 = mp->mnt_kern_flag;
196 		/*
197 		 * We only allow the filesystem to be reloaded if it
198 		 * is currently mounted read-only.
199 		 */
200 		if ((uap->flags & MNT_RELOAD) &&
201 		    ((mp->mnt_flag & MNT_RDONLY) == 0)) {
202 			cache_drop(&nch);
203 			vput(vp);
204 			return (EOPNOTSUPP);	/* Needs translation */
205 		}
206 		/*
207 		 * Only root, or the user that did the original mount is
208 		 * permitted to update it.
209 		 */
210 		if (mp->mnt_stat.f_owner != cred->cr_uid &&
211 		    (error = suser(td))) {
212 			cache_drop(&nch);
213 			vput(vp);
214 			return (error);
215 		}
216 		if (vfs_busy(mp, LK_NOWAIT)) {
217 			cache_drop(&nch);
218 			vput(vp);
219 			return (EBUSY);
220 		}
221 		if ((vp->v_flag & VMOUNT) != 0 || hasmount) {
222 			cache_drop(&nch);
223 			vfs_unbusy(mp);
224 			vput(vp);
225 			return (EBUSY);
226 		}
227 		vp->v_flag |= VMOUNT;
228 		mp->mnt_flag |=
229 		    uap->flags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE);
230 		vn_unlock(vp);
231 		goto update;
232 	}
233 	/*
234 	 * If the user is not root, ensure that they own the directory
235 	 * onto which we are attempting to mount.
236 	 */
237 	if ((error = VOP_GETATTR(vp, &va)) ||
238 	    (va.va_uid != cred->cr_uid && (error = suser(td)))) {
239 		cache_drop(&nch);
240 		vput(vp);
241 		return (error);
242 	}
243 	if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) {
244 		cache_drop(&nch);
245 		vput(vp);
246 		return (error);
247 	}
248 	if (vp->v_type != VDIR) {
249 		cache_drop(&nch);
250 		vput(vp);
251 		return (ENOTDIR);
252 	}
253 	if (vp->v_mount->mnt_kern_flag & MNTK_NOSTKMNT) {
254 		cache_drop(&nch);
255 		vput(vp);
256 		return (EPERM);
257 	}
258 	if ((error = copyinstr(uap->type, fstypename, MFSNAMELEN, NULL)) != 0) {
259 		cache_drop(&nch);
260 		vput(vp);
261 		return (error);
262 	}
263 	for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
264 		if (!strcmp(vfsp->vfc_name, fstypename))
265 			break;
266 	}
267 	if (vfsp == NULL) {
268 		linker_file_t lf;
269 
270 		/* Only load modules for root (very important!) */
271 		if ((error = suser(td)) != 0) {
272 			cache_drop(&nch);
273 			vput(vp);
274 			return error;
275 		}
276 		error = linker_load_file(fstypename, &lf);
277 		if (error || lf == NULL) {
278 			cache_drop(&nch);
279 			vput(vp);
280 			if (lf == NULL)
281 				error = ENODEV;
282 			return error;
283 		}
284 		lf->userrefs++;
285 		/* lookup again, see if the VFS was loaded */
286 		for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
287 			if (!strcmp(vfsp->vfc_name, fstypename))
288 				break;
289 		}
290 		if (vfsp == NULL) {
291 			lf->userrefs--;
292 			linker_file_unload(lf);
293 			cache_drop(&nch);
294 			vput(vp);
295 			return (ENODEV);
296 		}
297 	}
298 	if ((vp->v_flag & VMOUNT) != 0 || hasmount) {
299 		cache_drop(&nch);
300 		vput(vp);
301 		return (EBUSY);
302 	}
303 	vp->v_flag |= VMOUNT;
304 
305 	/*
306 	 * Allocate and initialize the filesystem.
307 	 */
308 	mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK);
309 	TAILQ_INIT(&mp->mnt_nvnodelist);
310 	TAILQ_INIT(&mp->mnt_reservedvnlist);
311 	TAILQ_INIT(&mp->mnt_jlist);
312 	mp->mnt_nvnodelistsize = 0;
313 	lockinit(&mp->mnt_lock, "vfslock", 0, 0);
314 	vfs_busy(mp, LK_NOWAIT);
315 	mp->mnt_op = vfsp->vfc_vfsops;
316 	mp->mnt_vfc = vfsp;
317 	vfsp->vfc_refcount++;
318 	mp->mnt_stat.f_type = vfsp->vfc_typenum;
319 	mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
320 	strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
321 	mp->mnt_stat.f_owner = cred->cr_uid;
322 	mp->mnt_iosize_max = DFLTPHYS;
323 	vn_unlock(vp);
324 update:
325 	/*
326 	 * Set the mount level flags.
327 	 */
328 	if (uap->flags & MNT_RDONLY)
329 		mp->mnt_flag |= MNT_RDONLY;
330 	else if (mp->mnt_flag & MNT_RDONLY)
331 		mp->mnt_kern_flag |= MNTK_WANTRDWR;
332 	mp->mnt_flag &=~ (MNT_NOSUID | MNT_NOEXEC | MNT_NODEV |
333 	    MNT_SYNCHRONOUS | MNT_UNION | MNT_ASYNC | MNT_NOATIME |
334 	    MNT_NOSYMFOLLOW | MNT_IGNORE |
335 	    MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
336 	mp->mnt_flag |= uap->flags & (MNT_NOSUID | MNT_NOEXEC |
337 	    MNT_NODEV | MNT_SYNCHRONOUS | MNT_UNION | MNT_ASYNC | MNT_FORCE |
338 	    MNT_NOSYMFOLLOW | MNT_IGNORE |
339 	    MNT_NOATIME | MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
340 	/*
341 	 * Mount the filesystem.
342 	 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
343 	 * get.
344 	 */
345 	error = VFS_MOUNT(mp, uap->path, uap->data, cred);
346 	if (mp->mnt_flag & MNT_UPDATE) {
347 		if (mp->mnt_kern_flag & MNTK_WANTRDWR)
348 			mp->mnt_flag &= ~MNT_RDONLY;
349 		mp->mnt_flag &=~ (MNT_UPDATE | MNT_RELOAD | MNT_FORCE);
350 		mp->mnt_kern_flag &=~ MNTK_WANTRDWR;
351 		if (error) {
352 			mp->mnt_flag = flag;
353 			mp->mnt_kern_flag = flag2;
354 		}
355 		vfs_unbusy(mp);
356 		vp->v_flag &= ~VMOUNT;
357 		vrele(vp);
358 		cache_drop(&nch);
359 		return (error);
360 	}
361 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
362 	/*
363 	 * Put the new filesystem on the mount list after root.  The mount
364 	 * point gets its own mnt_ncmountpt (unless the VFS already set one
365 	 * up) which represents the root of the mount.  The lookup code
366 	 * detects the mount point going forward and checks the root of
367 	 * the mount going backwards.
368 	 *
369 	 * It is not necessary to invalidate or purge the vnode underneath
370 	 * because elements under the mount will be given their own glue
371 	 * namecache record.
372 	 */
373 	if (!error) {
374 		if (mp->mnt_ncmountpt.ncp == NULL) {
375 			/*
376 			 * allocate, then unlock, but leave the ref intact
377 			 */
378 			cache_allocroot(&mp->mnt_ncmountpt, mp, NULL);
379 			cache_unlock(&mp->mnt_ncmountpt);
380 		}
381 		mp->mnt_ncmounton = nch;		/* inherits ref */
382 		nch.ncp->nc_flag |= NCF_ISMOUNTPT;
383 
384 		/* XXX get the root of the fs and cache_setvp(mnt_ncmountpt...) */
385 		vp->v_flag &= ~VMOUNT;
386 		mountlist_insert(mp, MNTINS_LAST);
387 		checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
388 		vn_unlock(vp);
389 		error = vfs_allocate_syncvnode(mp);
390 		vfs_unbusy(mp);
391 		error = VFS_START(mp, 0);
392 		vrele(vp);
393 	} else {
394 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
395 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
396 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
397 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
398 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
399 		vp->v_flag &= ~VMOUNT;
400 		mp->mnt_vfc->vfc_refcount--;
401 		vfs_unbusy(mp);
402 		kfree(mp, M_MOUNT);
403 		cache_drop(&nch);
404 		vput(vp);
405 	}
406 	return (error);
407 }
408 
409 /*
410  * Scan all active processes to see if any of them have a current
411  * or root directory onto which the new filesystem has just been
412  * mounted. If so, replace them with the new mount point.
413  *
414  * The passed ncp is ref'd and locked (from the mount code) and
415  * must be associated with the vnode representing the root of the
416  * mount point.
417  */
418 struct checkdirs_info {
419 	struct nchandle old_nch;
420 	struct nchandle new_nch;
421 	struct vnode *old_vp;
422 	struct vnode *new_vp;
423 };
424 
425 static int checkdirs_callback(struct proc *p, void *data);
426 
427 static void
428 checkdirs(struct nchandle *old_nch, struct nchandle *new_nch)
429 {
430 	struct checkdirs_info info;
431 	struct vnode *olddp;
432 	struct vnode *newdp;
433 	struct mount *mp;
434 
435 	/*
436 	 * If the old mount point's vnode has a usecount of 1, it is not
437 	 * being held as a descriptor anywhere.
438 	 */
439 	olddp = old_nch->ncp->nc_vp;
440 	if (olddp == NULL || olddp->v_sysref.refcnt == 1)
441 		return;
442 
443 	/*
444 	 * Force the root vnode of the new mount point to be resolved
445 	 * so we can update any matching processes.
446 	 */
447 	mp = new_nch->mount;
448 	if (VFS_ROOT(mp, &newdp))
449 		panic("mount: lost mount");
450 	cache_setunresolved(new_nch);
451 	cache_setvp(new_nch, newdp);
452 
453 	/*
454 	 * Special handling of the root node
455 	 */
456 	if (rootvnode == olddp) {
457 		vref(newdp);
458 		vfs_cache_setroot(newdp, cache_hold(new_nch));
459 	}
460 
461 	/*
462 	 * Pass newdp separately so the callback does not have to access
463 	 * it via new_nch->ncp->nc_vp.
464 	 */
465 	info.old_nch = *old_nch;
466 	info.new_nch = *new_nch;
467 	info.new_vp = newdp;
468 	allproc_scan(checkdirs_callback, &info);
469 	vput(newdp);
470 }
471 
472 /*
473  * NOTE: callback is not MP safe because the scanned process's filedesc
474  * structure can be ripped out from under us, amoung other things.
475  */
476 static int
477 checkdirs_callback(struct proc *p, void *data)
478 {
479 	struct checkdirs_info *info = data;
480 	struct filedesc *fdp;
481 	struct nchandle ncdrop1;
482 	struct nchandle ncdrop2;
483 	struct vnode *vprele1;
484 	struct vnode *vprele2;
485 
486 	if ((fdp = p->p_fd) != NULL) {
487 		cache_zero(&ncdrop1);
488 		cache_zero(&ncdrop2);
489 		vprele1 = NULL;
490 		vprele2 = NULL;
491 
492 		/*
493 		 * MPUNSAFE - XXX fdp can be pulled out from under a
494 		 * foreign process.
495 		 *
496 		 * A shared filedesc is ok, we don't have to copy it
497 		 * because we are making this change globally.
498 		 */
499 		spin_lock_wr(&fdp->fd_spin);
500 		if (fdp->fd_ncdir.mount == info->old_nch.mount &&
501 		    fdp->fd_ncdir.ncp == info->old_nch.ncp) {
502 			vprele1 = fdp->fd_cdir;
503 			vref(info->new_vp);
504 			fdp->fd_cdir = info->new_vp;
505 			ncdrop1 = fdp->fd_ncdir;
506 			cache_copy(&info->new_nch, &fdp->fd_ncdir);
507 		}
508 		if (fdp->fd_nrdir.mount == info->old_nch.mount &&
509 		    fdp->fd_nrdir.ncp == info->old_nch.ncp) {
510 			vprele2 = fdp->fd_rdir;
511 			vref(info->new_vp);
512 			fdp->fd_rdir = info->new_vp;
513 			ncdrop2 = fdp->fd_nrdir;
514 			cache_copy(&info->new_nch, &fdp->fd_nrdir);
515 		}
516 		spin_unlock_wr(&fdp->fd_spin);
517 		if (ncdrop1.ncp)
518 			cache_drop(&ncdrop1);
519 		if (ncdrop2.ncp)
520 			cache_drop(&ncdrop2);
521 		if (vprele1)
522 			vrele(vprele1);
523 		if (vprele2)
524 			vrele(vprele2);
525 	}
526 	return(0);
527 }
528 
529 /*
530  * Unmount a file system.
531  *
532  * Note: unmount takes a path to the vnode mounted on as argument,
533  * not special file (as before).
534  */
535 /*
536  * umount_args(char *path, int flags)
537  */
538 /* ARGSUSED */
539 int
540 sys_unmount(struct unmount_args *uap)
541 {
542 	struct thread *td = curthread;
543 	struct proc *p = td->td_proc;
544 	struct mount *mp = NULL;
545 	int error;
546 	struct nlookupdata nd;
547 
548 	KKASSERT(p);
549 	if (p->p_ucred->cr_prison != NULL)
550 		return (EPERM);
551 	if (usermount == 0 && (error = suser(td)))
552 		return (error);
553 
554 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
555 	if (error == 0)
556 		error = nlookup(&nd);
557 	if (error)
558 		goto out;
559 
560 	mp = nd.nl_nch.mount;
561 
562 	/*
563 	 * Only root, or the user that did the original mount is
564 	 * permitted to unmount this filesystem.
565 	 */
566 	if ((mp->mnt_stat.f_owner != p->p_ucred->cr_uid) &&
567 	    (error = suser(td)))
568 		goto out;
569 
570 	/*
571 	 * Don't allow unmounting the root file system.
572 	 */
573 	if (mp->mnt_flag & MNT_ROOTFS) {
574 		error = EINVAL;
575 		goto out;
576 	}
577 
578 	/*
579 	 * Must be the root of the filesystem
580 	 */
581 	if (nd.nl_nch.ncp != mp->mnt_ncmountpt.ncp) {
582 		error = EINVAL;
583 		goto out;
584 	}
585 
586 out:
587 	nlookup_done(&nd);
588 	if (error)
589 		return (error);
590 	return (dounmount(mp, uap->flags));
591 }
592 
593 /*
594  * Do the actual file system unmount.
595  */
596 static int
597 dounmount_interlock(struct mount *mp)
598 {
599 	if (mp->mnt_kern_flag & MNTK_UNMOUNT)
600 		return (EBUSY);
601 	mp->mnt_kern_flag |= MNTK_UNMOUNT;
602 	return(0);
603 }
604 
605 int
606 dounmount(struct mount *mp, int flags)
607 {
608 	struct namecache *ncp;
609 	struct nchandle nch;
610 	struct vnode *vp;
611 	int error;
612 	int async_flag;
613 	int lflags;
614 	int freeok = 1;
615 
616 	/*
617 	 * Exclusive access for unmounting purposes
618 	 */
619 	if ((error = mountlist_interlock(dounmount_interlock, mp)) != 0)
620 		return (error);
621 
622 	/*
623 	 * Allow filesystems to detect that a forced unmount is in progress.
624 	 */
625 	if (flags & MNT_FORCE)
626 		mp->mnt_kern_flag |= MNTK_UNMOUNTF;
627 	lflags = LK_EXCLUSIVE | ((flags & MNT_FORCE) ? 0 : LK_NOWAIT);
628 	error = lockmgr(&mp->mnt_lock, lflags);
629 	if (error) {
630 		mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
631 		if (mp->mnt_kern_flag & MNTK_MWAIT)
632 			wakeup(mp);
633 		return (error);
634 	}
635 
636 	if (mp->mnt_flag & MNT_EXPUBLIC)
637 		vfs_setpublicfs(NULL, NULL, NULL);
638 
639 	vfs_msync(mp, MNT_WAIT);
640 	async_flag = mp->mnt_flag & MNT_ASYNC;
641 	mp->mnt_flag &=~ MNT_ASYNC;
642 
643 	/*
644 	 * If this filesystem isn't aliasing other filesystems,
645 	 * try to invalidate any remaining namecache entries and
646 	 * check the count afterwords.
647 	 */
648 	if ((mp->mnt_kern_flag & MNTK_NCALIASED) == 0) {
649 		cache_lock(&mp->mnt_ncmountpt);
650 		cache_inval(&mp->mnt_ncmountpt, CINV_DESTROY|CINV_CHILDREN);
651 		cache_unlock(&mp->mnt_ncmountpt);
652 
653 		if ((ncp = mp->mnt_ncmountpt.ncp) != NULL &&
654 		    (ncp->nc_refs != 1 || TAILQ_FIRST(&ncp->nc_list))) {
655 
656 			if ((flags & MNT_FORCE) == 0) {
657 				error = EBUSY;
658 				mount_warning(mp, "Cannot unmount: "
659 						  "%d namecache "
660 						  "references still "
661 						  "present",
662 						  ncp->nc_refs - 1);
663 			} else {
664 				mount_warning(mp, "Forced unmount: "
665 						  "%d namecache "
666 						  "references still "
667 						  "present",
668 						  ncp->nc_refs - 1);
669 				freeok = 0;
670 			}
671 		}
672 	}
673 
674 	/*
675 	 * nchandle records ref the mount structure.  Expect a count of 1
676 	 * (our mount->mnt_ncmountpt).
677 	 */
678 	if (mp->mnt_refs != 1) {
679 		if ((flags & MNT_FORCE) == 0) {
680 			mount_warning(mp, "Cannot unmount: "
681 					  "%d process references still "
682 					  "present", mp->mnt_refs);
683 			error = EBUSY;
684 		} else {
685 			mount_warning(mp, "Forced unmount: "
686 					  "%d process references still "
687 					  "present", mp->mnt_refs);
688 			freeok = 0;
689 		}
690 	}
691 
692 	/*
693 	 * Decomission our special mnt_syncer vnode.  This also stops
694 	 * the vnlru code.  If we are unable to unmount we recommission
695 	 * the vnode.
696 	 */
697 	if (error == 0) {
698 		if ((vp = mp->mnt_syncer) != NULL) {
699 			mp->mnt_syncer = NULL;
700 			vrele(vp);
701 		}
702 		if (((mp->mnt_flag & MNT_RDONLY) ||
703 		     (error = VFS_SYNC(mp, MNT_WAIT)) == 0) ||
704 		    (flags & MNT_FORCE)) {
705 			error = VFS_UNMOUNT(mp, flags);
706 		}
707 	}
708 	if (error) {
709 		if (mp->mnt_syncer == NULL)
710 			vfs_allocate_syncvnode(mp);
711 		mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
712 		mp->mnt_flag |= async_flag;
713 		lockmgr(&mp->mnt_lock, LK_RELEASE);
714 		if (mp->mnt_kern_flag & MNTK_MWAIT)
715 			wakeup(mp);
716 		return (error);
717 	}
718 	/*
719 	 * Clean up any journals still associated with the mount after
720 	 * filesystem activity has ceased.
721 	 */
722 	journal_remove_all_journals(mp,
723 	    ((flags & MNT_FORCE) ? MC_JOURNAL_STOP_IMM : 0));
724 
725 	mountlist_remove(mp);
726 
727 	/*
728 	 * Remove any installed vnode ops here so the individual VFSs don't
729 	 * have to.
730 	 */
731 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
732 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
733 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
734 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
735 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
736 
737 	if (mp->mnt_ncmountpt.ncp != NULL) {
738 		nch = mp->mnt_ncmountpt;
739 		cache_zero(&mp->mnt_ncmountpt);
740 		cache_clrmountpt(&nch);
741 		cache_drop(&nch);
742 	}
743 	if (mp->mnt_ncmounton.ncp != NULL) {
744 		nch = mp->mnt_ncmounton;
745 		cache_zero(&mp->mnt_ncmounton);
746 		cache_clrmountpt(&nch);
747 		cache_drop(&nch);
748 	}
749 
750 	mp->mnt_vfc->vfc_refcount--;
751 	if (!TAILQ_EMPTY(&mp->mnt_nvnodelist))
752 		panic("unmount: dangling vnode");
753 	lockmgr(&mp->mnt_lock, LK_RELEASE);
754 	if (mp->mnt_kern_flag & MNTK_MWAIT)
755 		wakeup(mp);
756 	if (freeok)
757 		kfree(mp, M_MOUNT);
758 	return (0);
759 }
760 
761 static
762 void
763 mount_warning(struct mount *mp, const char *ctl, ...)
764 {
765 	char *ptr;
766 	char *buf;
767 	__va_list va;
768 
769 	__va_start(va, ctl);
770 	if (cache_fullpath(NULL, &mp->mnt_ncmounton, &ptr, &buf) == 0) {
771 		kprintf("unmount(%s): ", ptr);
772 		kvprintf(ctl, va);
773 		kprintf("\n");
774 		kfree(buf, M_TEMP);
775 	} else {
776 		kprintf("unmount(%p", mp);
777 		if (mp->mnt_ncmounton.ncp && mp->mnt_ncmounton.ncp->nc_name)
778 			kprintf(",%s", mp->mnt_ncmounton.ncp->nc_name);
779 		kprintf("): ");
780 		kvprintf(ctl, va);
781 		kprintf("\n");
782 	}
783 	__va_end(va);
784 }
785 
786 /*
787  * Shim cache_fullpath() to handle the case where a process is chrooted into
788  * a subdirectory of a mount.  In this case if the root mount matches the
789  * process root directory's mount we have to specify the process's root
790  * directory instead of the mount point, because the mount point might
791  * be above the root directory.
792  */
793 static
794 int
795 mount_path(struct proc *p, struct mount *mp, char **rb, char **fb)
796 {
797 	struct nchandle *nch;
798 
799 	if (p && p->p_fd->fd_nrdir.mount == mp)
800 		nch = &p->p_fd->fd_nrdir;
801 	else
802 		nch = &mp->mnt_ncmountpt;
803 	return(cache_fullpath(p, nch, rb, fb));
804 }
805 
806 /*
807  * Sync each mounted filesystem.
808  */
809 
810 #ifdef DEBUG
811 static int syncprt = 0;
812 SYSCTL_INT(_debug, OID_AUTO, syncprt, CTLFLAG_RW, &syncprt, 0, "");
813 #endif /* DEBUG */
814 
815 static int sync_callback(struct mount *mp, void *data);
816 
817 /* ARGSUSED */
818 int
819 sys_sync(struct sync_args *uap)
820 {
821 	mountlist_scan(sync_callback, NULL, MNTSCAN_FORWARD);
822 #ifdef DEBUG
823 	/*
824 	 * print out buffer pool stat information on each sync() call.
825 	 */
826 	if (syncprt)
827 		vfs_bufstats();
828 #endif /* DEBUG */
829 	return (0);
830 }
831 
832 static
833 int
834 sync_callback(struct mount *mp, void *data __unused)
835 {
836 	int asyncflag;
837 
838 	if ((mp->mnt_flag & MNT_RDONLY) == 0) {
839 		asyncflag = mp->mnt_flag & MNT_ASYNC;
840 		mp->mnt_flag &= ~MNT_ASYNC;
841 		vfs_msync(mp, MNT_NOWAIT);
842 		VFS_SYNC(mp, MNT_NOWAIT);
843 		mp->mnt_flag |= asyncflag;
844 	}
845 	return(0);
846 }
847 
848 /* XXX PRISON: could be per prison flag */
849 static int prison_quotas;
850 #if 0
851 SYSCTL_INT(_kern_prison, OID_AUTO, quotas, CTLFLAG_RW, &prison_quotas, 0, "");
852 #endif
853 
854 /*
855  *  quotactl_args(char *path, int fcmd, int uid, caddr_t arg)
856  *
857  * Change filesystem quotas.
858  */
859 /* ARGSUSED */
860 int
861 sys_quotactl(struct quotactl_args *uap)
862 {
863 	struct nlookupdata nd;
864 	struct thread *td;
865 	struct proc *p;
866 	struct mount *mp;
867 	int error;
868 
869 	td = curthread;
870 	p = td->td_proc;
871 	if (p->p_ucred->cr_prison && !prison_quotas)
872 		return (EPERM);
873 
874 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
875 	if (error == 0)
876 		error = nlookup(&nd);
877 	if (error == 0) {
878 		mp = nd.nl_nch.mount;
879 		error = VFS_QUOTACTL(mp, uap->cmd, uap->uid,
880 				    uap->arg, nd.nl_cred);
881 	}
882 	nlookup_done(&nd);
883 	return (error);
884 }
885 
886 /*
887  * mountctl(char *path, int op, int fd, const void *ctl, int ctllen,
888  *		void *buf, int buflen)
889  *
890  * This function operates on a mount point and executes the specified
891  * operation using the specified control data, and possibly returns data.
892  *
893  * The actual number of bytes stored in the result buffer is returned, 0
894  * if none, otherwise an error is returned.
895  */
896 /* ARGSUSED */
897 int
898 sys_mountctl(struct mountctl_args *uap)
899 {
900 	struct thread *td = curthread;
901 	struct proc *p = td->td_proc;
902 	struct file *fp;
903 	void *ctl = NULL;
904 	void *buf = NULL;
905 	char *path = NULL;
906 	int error;
907 
908 	/*
909 	 * Sanity and permissions checks.  We must be root.
910 	 */
911 	KKASSERT(p);
912 	if (p->p_ucred->cr_prison != NULL)
913 		return (EPERM);
914 	if ((error = suser(td)) != 0)
915 		return (error);
916 
917 	/*
918 	 * Argument length checks
919 	 */
920 	if (uap->ctllen < 0 || uap->ctllen > 1024)
921 		return (EINVAL);
922 	if (uap->buflen < 0 || uap->buflen > 16 * 1024)
923 		return (EINVAL);
924 	if (uap->path == NULL)
925 		return (EINVAL);
926 
927 	/*
928 	 * Allocate the necessary buffers and copyin data
929 	 */
930 	path = objcache_get(namei_oc, M_WAITOK);
931 	error = copyinstr(uap->path, path, MAXPATHLEN, NULL);
932 	if (error)
933 		goto done;
934 
935 	if (uap->ctllen) {
936 		ctl = kmalloc(uap->ctllen + 1, M_TEMP, M_WAITOK|M_ZERO);
937 		error = copyin(uap->ctl, ctl, uap->ctllen);
938 		if (error)
939 			goto done;
940 	}
941 	if (uap->buflen)
942 		buf = kmalloc(uap->buflen + 1, M_TEMP, M_WAITOK|M_ZERO);
943 
944 	/*
945 	 * Validate the descriptor
946 	 */
947 	if (uap->fd >= 0) {
948 		fp = holdfp(p->p_fd, uap->fd, -1);
949 		if (fp == NULL) {
950 			error = EBADF;
951 			goto done;
952 		}
953 	} else {
954 		fp = NULL;
955 	}
956 
957 	/*
958 	 * Execute the internal kernel function and clean up.
959 	 */
960 	error = kern_mountctl(path, uap->op, fp, ctl, uap->ctllen, buf, uap->buflen, &uap->sysmsg_result);
961 	if (fp)
962 		fdrop(fp);
963 	if (error == 0 && uap->sysmsg_result > 0)
964 		error = copyout(buf, uap->buf, uap->sysmsg_result);
965 done:
966 	if (path)
967 		objcache_put(namei_oc, path);
968 	if (ctl)
969 		kfree(ctl, M_TEMP);
970 	if (buf)
971 		kfree(buf, M_TEMP);
972 	return (error);
973 }
974 
975 /*
976  * Execute a mount control operation by resolving the path to a mount point
977  * and calling vop_mountctl().
978  */
979 int
980 kern_mountctl(const char *path, int op, struct file *fp,
981 		const void *ctl, int ctllen,
982 		void *buf, int buflen, int *res)
983 {
984 	struct vnode *vp;
985 	struct mount *mp;
986 	struct nlookupdata nd;
987 	int error;
988 
989 	*res = 0;
990 	vp = NULL;
991 	error = nlookup_init(&nd, path, UIO_SYSSPACE, NLC_FOLLOW);
992 	if (error == 0)
993 		error = nlookup(&nd);
994 	if (error == 0)
995 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
996 	nlookup_done(&nd);
997 	if (error)
998 		return (error);
999 
1000 	mp = vp->v_mount;
1001 
1002 	/*
1003 	 * Must be the root of the filesystem
1004 	 */
1005 	if ((vp->v_flag & VROOT) == 0) {
1006 		vput(vp);
1007 		return (EINVAL);
1008 	}
1009 	error = vop_mountctl(mp->mnt_vn_use_ops, op, fp, ctl, ctllen,
1010 				buf, buflen, res);
1011 	vput(vp);
1012 	return (error);
1013 }
1014 
1015 int
1016 kern_statfs(struct nlookupdata *nd, struct statfs *buf)
1017 {
1018 	struct thread *td = curthread;
1019 	struct proc *p = td->td_proc;
1020 	struct mount *mp;
1021 	struct statfs *sp;
1022 	char *fullpath, *freepath;
1023 	int error;
1024 
1025 	if ((error = nlookup(nd)) != 0)
1026 		return (error);
1027 	mp = nd->nl_nch.mount;
1028 	sp = &mp->mnt_stat;
1029 	if ((error = VFS_STATFS(mp, sp, nd->nl_cred)) != 0)
1030 		return (error);
1031 
1032 	error = mount_path(p, mp, &fullpath, &freepath);
1033 	if (error)
1034 		return(error);
1035 	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1036 	strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1037 	kfree(freepath, M_TEMP);
1038 
1039 	sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1040 	bcopy(sp, buf, sizeof(*buf));
1041 	/* Only root should have access to the fsid's. */
1042 	if (suser(td))
1043 		buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
1044 	return (0);
1045 }
1046 
1047 /*
1048  * statfs_args(char *path, struct statfs *buf)
1049  *
1050  * Get filesystem statistics.
1051  */
1052 int
1053 sys_statfs(struct statfs_args *uap)
1054 {
1055 	struct nlookupdata nd;
1056 	struct statfs buf;
1057 	int error;
1058 
1059 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1060 	if (error == 0)
1061 		error = kern_statfs(&nd, &buf);
1062 	nlookup_done(&nd);
1063 	if (error == 0)
1064 		error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1065 	return (error);
1066 }
1067 
1068 int
1069 kern_fstatfs(int fd, struct statfs *buf)
1070 {
1071 	struct thread *td = curthread;
1072 	struct proc *p = td->td_proc;
1073 	struct file *fp;
1074 	struct mount *mp;
1075 	struct statfs *sp;
1076 	char *fullpath, *freepath;
1077 	int error;
1078 
1079 	KKASSERT(p);
1080 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
1081 		return (error);
1082 	mp = ((struct vnode *)fp->f_data)->v_mount;
1083 	if (mp == NULL) {
1084 		error = EBADF;
1085 		goto done;
1086 	}
1087 	if (fp->f_cred == NULL) {
1088 		error = EINVAL;
1089 		goto done;
1090 	}
1091 	sp = &mp->mnt_stat;
1092 	if ((error = VFS_STATFS(mp, sp, fp->f_cred)) != 0)
1093 		goto done;
1094 
1095 	if ((error = mount_path(p, mp, &fullpath, &freepath)) != 0)
1096 		goto done;
1097 	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1098 	strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1099 	kfree(freepath, M_TEMP);
1100 
1101 	sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1102 	bcopy(sp, buf, sizeof(*buf));
1103 
1104 	/* Only root should have access to the fsid's. */
1105 	if (suser(td))
1106 		buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
1107 	error = 0;
1108 done:
1109 	fdrop(fp);
1110 	return (error);
1111 }
1112 
1113 /*
1114  * fstatfs_args(int fd, struct statfs *buf)
1115  *
1116  * Get filesystem statistics.
1117  */
1118 int
1119 sys_fstatfs(struct fstatfs_args *uap)
1120 {
1121 	struct statfs buf;
1122 	int error;
1123 
1124 	error = kern_fstatfs(uap->fd, &buf);
1125 
1126 	if (error == 0)
1127 		error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1128 	return (error);
1129 }
1130 
1131 int
1132 kern_statvfs(struct nlookupdata *nd, struct statvfs *buf)
1133 {
1134 	struct mount *mp;
1135 	struct statvfs *sp;
1136 	int error;
1137 
1138 	if ((error = nlookup(nd)) != 0)
1139 		return (error);
1140 	mp = nd->nl_nch.mount;
1141 	sp = &mp->mnt_vstat;
1142 	if ((error = VFS_STATVFS(mp, sp, nd->nl_cred)) != 0)
1143 		return (error);
1144 
1145 	sp->f_flag = 0;
1146 	if (mp->mnt_flag & MNT_RDONLY)
1147 		sp->f_flag |= ST_RDONLY;
1148 	if (mp->mnt_flag & MNT_NOSUID)
1149 		sp->f_flag |= ST_NOSUID;
1150 	bcopy(sp, buf, sizeof(*buf));
1151 	return (0);
1152 }
1153 
1154 /*
1155  * statfs_args(char *path, struct statfs *buf)
1156  *
1157  * Get filesystem statistics.
1158  */
1159 int
1160 sys_statvfs(struct statvfs_args *uap)
1161 {
1162 	struct nlookupdata nd;
1163 	struct statvfs buf;
1164 	int error;
1165 
1166 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1167 	if (error == 0)
1168 		error = kern_statvfs(&nd, &buf);
1169 	nlookup_done(&nd);
1170 	if (error == 0)
1171 		error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1172 	return (error);
1173 }
1174 
1175 int
1176 kern_fstatvfs(int fd, struct statvfs *buf)
1177 {
1178 	struct thread *td = curthread;
1179 	struct proc *p = td->td_proc;
1180 	struct file *fp;
1181 	struct mount *mp;
1182 	struct statvfs *sp;
1183 	int error;
1184 
1185 	KKASSERT(p);
1186 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
1187 		return (error);
1188 	mp = ((struct vnode *)fp->f_data)->v_mount;
1189 	if (mp == NULL) {
1190 		error = EBADF;
1191 		goto done;
1192 	}
1193 	if (fp->f_cred == NULL) {
1194 		error = EINVAL;
1195 		goto done;
1196 	}
1197 	sp = &mp->mnt_vstat;
1198 	if ((error = VFS_STATVFS(mp, sp, fp->f_cred)) != 0)
1199 		goto done;
1200 
1201 	sp->f_flag = 0;
1202 	if (mp->mnt_flag & MNT_RDONLY)
1203 		sp->f_flag |= ST_RDONLY;
1204 	if (mp->mnt_flag & MNT_NOSUID)
1205 		sp->f_flag |= ST_NOSUID;
1206 
1207 	bcopy(sp, buf, sizeof(*buf));
1208 	error = 0;
1209 done:
1210 	fdrop(fp);
1211 	return (error);
1212 }
1213 
1214 /*
1215  * fstatfs_args(int fd, struct statfs *buf)
1216  *
1217  * Get filesystem statistics.
1218  */
1219 int
1220 sys_fstatvfs(struct fstatvfs_args *uap)
1221 {
1222 	struct statvfs buf;
1223 	int error;
1224 
1225 	error = kern_fstatvfs(uap->fd, &buf);
1226 
1227 	if (error == 0)
1228 		error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1229 	return (error);
1230 }
1231 
1232 /*
1233  * getfsstat_args(struct statfs *buf, long bufsize, int flags)
1234  *
1235  * Get statistics on all filesystems.
1236  */
1237 
1238 struct getfsstat_info {
1239 	struct statfs *sfsp;
1240 	long count;
1241 	long maxcount;
1242 	int error;
1243 	int flags;
1244 	struct proc *p;
1245 };
1246 
1247 static int getfsstat_callback(struct mount *, void *);
1248 
1249 /* ARGSUSED */
1250 int
1251 sys_getfsstat(struct getfsstat_args *uap)
1252 {
1253 	struct thread *td = curthread;
1254 	struct proc *p = td->td_proc;
1255 	struct getfsstat_info info;
1256 
1257 	bzero(&info, sizeof(info));
1258 
1259 	info.maxcount = uap->bufsize / sizeof(struct statfs);
1260 	info.sfsp = uap->buf;
1261 	info.count = 0;
1262 	info.flags = uap->flags;
1263 	info.p = p;
1264 
1265 	mountlist_scan(getfsstat_callback, &info, MNTSCAN_FORWARD);
1266 	if (info.sfsp && info.count > info.maxcount)
1267 		uap->sysmsg_result = info.maxcount;
1268 	else
1269 		uap->sysmsg_result = info.count;
1270 	return (info.error);
1271 }
1272 
1273 static int
1274 getfsstat_callback(struct mount *mp, void *data)
1275 {
1276 	struct getfsstat_info *info = data;
1277 	struct statfs *sp;
1278 	char *freepath;
1279 	char *fullpath;
1280 	int error;
1281 
1282 	if (info->sfsp && info->count < info->maxcount) {
1283 		if (info->p && !chroot_visible_mnt(mp, info->p))
1284 			return(0);
1285 		sp = &mp->mnt_stat;
1286 
1287 		/*
1288 		 * If MNT_NOWAIT or MNT_LAZY is specified, do not
1289 		 * refresh the fsstat cache. MNT_NOWAIT or MNT_LAZY
1290 		 * overrides MNT_WAIT.
1291 		 */
1292 		if (((info->flags & (MNT_LAZY|MNT_NOWAIT)) == 0 ||
1293 		    (info->flags & MNT_WAIT)) &&
1294 		    (error = VFS_STATFS(mp, sp, info->p->p_ucred))) {
1295 			return(0);
1296 		}
1297 		sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1298 
1299 		error = mount_path(info->p, mp, &fullpath, &freepath);
1300 		if (error) {
1301 			info->error = error;
1302 			return(-1);
1303 		}
1304 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1305 		strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1306 		kfree(freepath, M_TEMP);
1307 
1308 		error = copyout(sp, info->sfsp, sizeof(*sp));
1309 		if (error) {
1310 			info->error = error;
1311 			return (-1);
1312 		}
1313 		++info->sfsp;
1314 	}
1315 	info->count++;
1316 	return(0);
1317 }
1318 
1319 /*
1320  * getvfsstat_args(struct statfs *buf, struct statvfs *vbuf,
1321 		   long bufsize, int flags)
1322  *
1323  * Get statistics on all filesystems.
1324  */
1325 
1326 struct getvfsstat_info {
1327 	struct statfs *sfsp;
1328 	struct statvfs *vsfsp;
1329 	long count;
1330 	long maxcount;
1331 	int error;
1332 	int flags;
1333 	struct proc *p;
1334 };
1335 
1336 static int getvfsstat_callback(struct mount *, void *);
1337 
1338 /* ARGSUSED */
1339 int
1340 sys_getvfsstat(struct getvfsstat_args *uap)
1341 {
1342 	struct thread *td = curthread;
1343 	struct proc *p = td->td_proc;
1344 	struct getvfsstat_info info;
1345 
1346 	bzero(&info, sizeof(info));
1347 
1348 	info.maxcount = uap->vbufsize / sizeof(struct statvfs);
1349 	info.sfsp = uap->buf;
1350 	info.vsfsp = uap->vbuf;
1351 	info.count = 0;
1352 	info.flags = uap->flags;
1353 	info.p = p;
1354 
1355 	mountlist_scan(getvfsstat_callback, &info, MNTSCAN_FORWARD);
1356 	if (info.vsfsp && info.count > info.maxcount)
1357 		uap->sysmsg_result = info.maxcount;
1358 	else
1359 		uap->sysmsg_result = info.count;
1360 	return (info.error);
1361 }
1362 
1363 static int
1364 getvfsstat_callback(struct mount *mp, void *data)
1365 {
1366 	struct getvfsstat_info *info = data;
1367 	struct statfs *sp;
1368 	struct statvfs *vsp;
1369 	char *freepath;
1370 	char *fullpath;
1371 	int error;
1372 
1373 	if (info->vsfsp && info->count < info->maxcount) {
1374 		if (info->p && !chroot_visible_mnt(mp, info->p))
1375 			return(0);
1376 		sp = &mp->mnt_stat;
1377 		vsp = &mp->mnt_vstat;
1378 
1379 		/*
1380 		 * If MNT_NOWAIT or MNT_LAZY is specified, do not
1381 		 * refresh the fsstat cache. MNT_NOWAIT or MNT_LAZY
1382 		 * overrides MNT_WAIT.
1383 		 */
1384 		if (((info->flags & (MNT_LAZY|MNT_NOWAIT)) == 0 ||
1385 		    (info->flags & MNT_WAIT)) &&
1386 		    (error = VFS_STATFS(mp, sp, info->p->p_ucred))) {
1387 			return(0);
1388 		}
1389 		sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1390 
1391 		if (((info->flags & (MNT_LAZY|MNT_NOWAIT)) == 0 ||
1392 		    (info->flags & MNT_WAIT)) &&
1393 		    (error = VFS_STATVFS(mp, vsp, info->p->p_ucred))) {
1394 			return(0);
1395 		}
1396 		vsp->f_flag = 0;
1397 		if (mp->mnt_flag & MNT_RDONLY)
1398 			vsp->f_flag |= ST_RDONLY;
1399 		if (mp->mnt_flag & MNT_NOSUID)
1400 			vsp->f_flag |= ST_NOSUID;
1401 
1402 		error = mount_path(info->p, mp, &fullpath, &freepath);
1403 		if (error) {
1404 			info->error = error;
1405 			return(-1);
1406 		}
1407 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1408 		strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1409 		kfree(freepath, M_TEMP);
1410 
1411 		error = copyout(sp, info->sfsp, sizeof(*sp));
1412 		if (error == 0)
1413 			error = copyout(vsp, info->vsfsp, sizeof(*vsp));
1414 		if (error) {
1415 			info->error = error;
1416 			return (-1);
1417 		}
1418 		++info->sfsp;
1419 		++info->vsfsp;
1420 	}
1421 	info->count++;
1422 	return(0);
1423 }
1424 
1425 
1426 /*
1427  * fchdir_args(int fd)
1428  *
1429  * Change current working directory to a given file descriptor.
1430  */
1431 /* ARGSUSED */
1432 int
1433 sys_fchdir(struct fchdir_args *uap)
1434 {
1435 	struct thread *td = curthread;
1436 	struct proc *p = td->td_proc;
1437 	struct filedesc *fdp = p->p_fd;
1438 	struct vnode *vp, *ovp;
1439 	struct mount *mp;
1440 	struct file *fp;
1441 	struct nchandle nch, onch, tnch;
1442 	int error;
1443 
1444 	if ((error = holdvnode(fdp, uap->fd, &fp)) != 0)
1445 		return (error);
1446 	vp = (struct vnode *)fp->f_data;
1447 	vref(vp);
1448 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1449 	if (vp->v_type != VDIR || fp->f_nchandle.ncp == NULL)
1450 		error = ENOTDIR;
1451 	else
1452 		error = VOP_ACCESS(vp, VEXEC, p->p_ucred);
1453 	if (error) {
1454 		vput(vp);
1455 		fdrop(fp);
1456 		return (error);
1457 	}
1458 	cache_copy(&fp->f_nchandle, &nch);
1459 
1460 	/*
1461 	 * If the ncp has become a mount point, traverse through
1462 	 * the mount point.
1463 	 */
1464 
1465 	while (!error && (nch.ncp->nc_flag & NCF_ISMOUNTPT) &&
1466 	       (mp = cache_findmount(&nch)) != NULL
1467 	) {
1468 		error = nlookup_mp(mp, &tnch);
1469 		if (error == 0) {
1470 			cache_unlock(&tnch);	/* leave ref intact */
1471 			vput(vp);
1472 			vp = tnch.ncp->nc_vp;
1473 			error = vget(vp, LK_SHARED);
1474 			KKASSERT(error == 0);
1475 			cache_drop(&nch);
1476 			nch = tnch;
1477 		}
1478 	}
1479 	if (error == 0) {
1480 		ovp = fdp->fd_cdir;
1481 		onch = fdp->fd_ncdir;
1482 		vn_unlock(vp);		/* leave ref intact */
1483 		fdp->fd_cdir = vp;
1484 		fdp->fd_ncdir = nch;
1485 		cache_drop(&onch);
1486 		vrele(ovp);
1487 	} else {
1488 		cache_drop(&nch);
1489 		vput(vp);
1490 	}
1491 	fdrop(fp);
1492 	return (error);
1493 }
1494 
1495 int
1496 kern_chdir(struct nlookupdata *nd)
1497 {
1498 	struct thread *td = curthread;
1499 	struct proc *p = td->td_proc;
1500 	struct filedesc *fdp = p->p_fd;
1501 	struct vnode *vp, *ovp;
1502 	struct nchandle onch;
1503 	int error;
1504 
1505 	if ((error = nlookup(nd)) != 0)
1506 		return (error);
1507 	if ((vp = nd->nl_nch.ncp->nc_vp) == NULL)
1508 		return (ENOENT);
1509 	if ((error = vget(vp, LK_SHARED)) != 0)
1510 		return (error);
1511 
1512 	error = checkvp_chdir(vp, td);
1513 	vn_unlock(vp);
1514 	if (error == 0) {
1515 		ovp = fdp->fd_cdir;
1516 		onch = fdp->fd_ncdir;
1517 		cache_unlock(&nd->nl_nch);	/* leave reference intact */
1518 		fdp->fd_ncdir = nd->nl_nch;
1519 		fdp->fd_cdir = vp;
1520 		cache_drop(&onch);
1521 		vrele(ovp);
1522 		cache_zero(&nd->nl_nch);
1523 	} else {
1524 		vrele(vp);
1525 	}
1526 	return (error);
1527 }
1528 
1529 /*
1530  * chdir_args(char *path)
1531  *
1532  * Change current working directory (``.'').
1533  */
1534 int
1535 sys_chdir(struct chdir_args *uap)
1536 {
1537 	struct nlookupdata nd;
1538 	int error;
1539 
1540 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1541 	if (error == 0)
1542 		error = kern_chdir(&nd);
1543 	nlookup_done(&nd);
1544 	return (error);
1545 }
1546 
1547 /*
1548  * Helper function for raised chroot(2) security function:  Refuse if
1549  * any filedescriptors are open directories.
1550  */
1551 static int
1552 chroot_refuse_vdir_fds(struct filedesc *fdp)
1553 {
1554 	struct vnode *vp;
1555 	struct file *fp;
1556 	int error;
1557 	int fd;
1558 
1559 	for (fd = 0; fd < fdp->fd_nfiles ; fd++) {
1560 		if ((error = holdvnode(fdp, fd, &fp)) != 0)
1561 			continue;
1562 		vp = (struct vnode *)fp->f_data;
1563 		if (vp->v_type != VDIR) {
1564 			fdrop(fp);
1565 			continue;
1566 		}
1567 		fdrop(fp);
1568 		return(EPERM);
1569 	}
1570 	return (0);
1571 }
1572 
1573 /*
1574  * This sysctl determines if we will allow a process to chroot(2) if it
1575  * has a directory open:
1576  *	0: disallowed for all processes.
1577  *	1: allowed for processes that were not already chroot(2)'ed.
1578  *	2: allowed for all processes.
1579  */
1580 
1581 static int chroot_allow_open_directories = 1;
1582 
1583 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW,
1584      &chroot_allow_open_directories, 0, "");
1585 
1586 /*
1587  * chroot to the specified namecache entry.  We obtain the vp from the
1588  * namecache data.  The passed ncp must be locked and referenced and will
1589  * remain locked and referenced on return.
1590  */
1591 int
1592 kern_chroot(struct nchandle *nch)
1593 {
1594 	struct thread *td = curthread;
1595 	struct proc *p = td->td_proc;
1596 	struct filedesc *fdp = p->p_fd;
1597 	struct vnode *vp;
1598 	int error;
1599 
1600 	/*
1601 	 * Only root can chroot
1602 	 */
1603 	if ((error = suser_cred(p->p_ucred, PRISON_ROOT)) != 0)
1604 		return (error);
1605 
1606 	/*
1607 	 * Disallow open directory descriptors (fchdir() breakouts).
1608 	 */
1609 	if (chroot_allow_open_directories == 0 ||
1610 	   (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) {
1611 		if ((error = chroot_refuse_vdir_fds(fdp)) != 0)
1612 			return (error);
1613 	}
1614 	if ((vp = nch->ncp->nc_vp) == NULL)
1615 		return (ENOENT);
1616 
1617 	if ((error = vget(vp, LK_SHARED)) != 0)
1618 		return (error);
1619 
1620 	/*
1621 	 * Check the validity of vp as a directory to change to and
1622 	 * associate it with rdir/jdir.
1623 	 */
1624 	error = checkvp_chdir(vp, td);
1625 	vn_unlock(vp);			/* leave reference intact */
1626 	if (error == 0) {
1627 		vrele(fdp->fd_rdir);
1628 		fdp->fd_rdir = vp;	/* reference inherited by fd_rdir */
1629 		cache_drop(&fdp->fd_nrdir);
1630 		cache_copy(nch, &fdp->fd_nrdir);
1631 		if (fdp->fd_jdir == NULL) {
1632 			fdp->fd_jdir = vp;
1633 			vref(fdp->fd_jdir);
1634 			cache_copy(nch, &fdp->fd_njdir);
1635 		}
1636 	} else {
1637 		vrele(vp);
1638 	}
1639 	return (error);
1640 }
1641 
1642 /*
1643  * chroot_args(char *path)
1644  *
1645  * Change notion of root (``/'') directory.
1646  */
1647 /* ARGSUSED */
1648 int
1649 sys_chroot(struct chroot_args *uap)
1650 {
1651 	struct thread *td = curthread;
1652 	struct nlookupdata nd;
1653 	int error;
1654 
1655 	KKASSERT(td->td_proc);
1656 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1657 	if (error) {
1658 		nlookup_done(&nd);
1659 		return(error);
1660 	}
1661 	error = nlookup(&nd);
1662 	if (error == 0)
1663 		error = kern_chroot(&nd.nl_nch);
1664 	nlookup_done(&nd);
1665 	return(error);
1666 }
1667 
1668 /*
1669  * Common routine for chroot and chdir.  Given a locked, referenced vnode,
1670  * determine whether it is legal to chdir to the vnode.  The vnode's state
1671  * is not changed by this call.
1672  */
1673 int
1674 checkvp_chdir(struct vnode *vp, struct thread *td)
1675 {
1676 	int error;
1677 
1678 	if (vp->v_type != VDIR)
1679 		error = ENOTDIR;
1680 	else
1681 		error = VOP_ACCESS(vp, VEXEC, td->td_proc->p_ucred);
1682 	return (error);
1683 }
1684 
1685 int
1686 kern_open(struct nlookupdata *nd, int oflags, int mode, int *res)
1687 {
1688 	struct thread *td = curthread;
1689 	struct proc *p = td->td_proc;
1690 	struct lwp *lp = td->td_lwp;
1691 	struct filedesc *fdp = p->p_fd;
1692 	int cmode, flags;
1693 	struct file *nfp;
1694 	struct file *fp;
1695 	struct vnode *vp;
1696 	int type, indx, error;
1697 	struct flock lf;
1698 
1699 	if ((oflags & O_ACCMODE) == O_ACCMODE)
1700 		return (EINVAL);
1701 	flags = FFLAGS(oflags);
1702 	error = falloc(p, &nfp, NULL);
1703 	if (error)
1704 		return (error);
1705 	fp = nfp;
1706 	cmode = ((mode &~ fdp->fd_cmask) & ALLPERMS) &~ S_ISTXT;
1707 
1708 	/*
1709 	 * XXX p_dupfd is a real mess.  It allows a device to return a
1710 	 * file descriptor to be duplicated rather then doing the open
1711 	 * itself.
1712 	 */
1713 	lp->lwp_dupfd = -1;
1714 
1715 	/*
1716 	 * Call vn_open() to do the lookup and assign the vnode to the
1717 	 * file pointer.  vn_open() does not change the ref count on fp
1718 	 * and the vnode, on success, will be inherited by the file pointer
1719 	 * and unlocked.
1720 	 */
1721 	nd->nl_flags |= NLC_LOCKVP;
1722 	error = vn_open(nd, fp, flags, cmode);
1723 	nlookup_done(nd);
1724 	if (error) {
1725 		/*
1726 		 * handle special fdopen() case.  bleh.  dupfdopen() is
1727 		 * responsible for dropping the old contents of ofiles[indx]
1728 		 * if it succeeds.
1729 		 *
1730 		 * Note that fsetfd() will add a ref to fp which represents
1731 		 * the fd_files[] assignment.  We must still drop our
1732 		 * reference.
1733 		 */
1734 		if ((error == ENODEV || error == ENXIO) && lp->lwp_dupfd >= 0) {
1735 			if (fdalloc(p, 0, &indx) == 0) {
1736 				error = dupfdopen(p, indx, lp->lwp_dupfd, flags, error);
1737 				if (error == 0) {
1738 					*res = indx;
1739 					fdrop(fp);	/* our ref */
1740 					return (0);
1741 				}
1742 				fsetfd(p, NULL, indx);
1743 			}
1744 		}
1745 		fdrop(fp);	/* our ref */
1746 		if (error == ERESTART)
1747 			error = EINTR;
1748 		return (error);
1749 	}
1750 
1751 	/*
1752 	 * ref the vnode for ourselves so it can't be ripped out from under
1753 	 * is.  XXX need an ND flag to request that the vnode be returned
1754 	 * anyway.
1755 	 *
1756 	 * Reserve a file descriptor but do not assign it until the open
1757 	 * succeeds.
1758 	 */
1759 	vp = (struct vnode *)fp->f_data;
1760 	vref(vp);
1761 	if ((error = fdalloc(p, 0, &indx)) != 0) {
1762 		fdrop(fp);
1763 		vrele(vp);
1764 		return (error);
1765 	}
1766 
1767 	/*
1768 	 * If no error occurs the vp will have been assigned to the file
1769 	 * pointer.
1770 	 */
1771 	lp->lwp_dupfd = 0;
1772 
1773 	if (flags & (O_EXLOCK | O_SHLOCK)) {
1774 		lf.l_whence = SEEK_SET;
1775 		lf.l_start = 0;
1776 		lf.l_len = 0;
1777 		if (flags & O_EXLOCK)
1778 			lf.l_type = F_WRLCK;
1779 		else
1780 			lf.l_type = F_RDLCK;
1781 		if (flags & FNONBLOCK)
1782 			type = 0;
1783 		else
1784 			type = F_WAIT;
1785 
1786 		if ((error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type)) != 0) {
1787 			/*
1788 			 * lock request failed.  Clean up the reserved
1789 			 * descriptor.
1790 			 */
1791 			vrele(vp);
1792 			fsetfd(p, NULL, indx);
1793 			fdrop(fp);
1794 			return (error);
1795 		}
1796 		fp->f_flag |= FHASLOCK;
1797 	}
1798 #if 0
1799 	/*
1800 	 * Assert that all regular file vnodes were created with a object.
1801 	 */
1802 	KASSERT(vp->v_type != VREG || vp->v_object != NULL,
1803 		("open: regular file has no backing object after vn_open"));
1804 #endif
1805 
1806 	vrele(vp);
1807 
1808 	/*
1809 	 * release our private reference, leaving the one associated with the
1810 	 * descriptor table intact.
1811 	 */
1812 	fsetfd(p, fp, indx);
1813 	fdrop(fp);
1814 	*res = indx;
1815 	return (0);
1816 }
1817 
1818 /*
1819  * open_args(char *path, int flags, int mode)
1820  *
1821  * Check permissions, allocate an open file structure,
1822  * and call the device open routine if any.
1823  */
1824 int
1825 sys_open(struct open_args *uap)
1826 {
1827 	struct nlookupdata nd;
1828 	int error;
1829 
1830 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1831 	if (error == 0) {
1832 		error = kern_open(&nd, uap->flags,
1833 				    uap->mode, &uap->sysmsg_result);
1834 	}
1835 	nlookup_done(&nd);
1836 	return (error);
1837 }
1838 
1839 int
1840 kern_mknod(struct nlookupdata *nd, int mode, int rmajor, int rminor)
1841 {
1842 	struct thread *td = curthread;
1843 	struct proc *p = td->td_proc;
1844 	struct vnode *vp;
1845 	struct vattr vattr;
1846 	int error;
1847 	int whiteout = 0;
1848 
1849 	KKASSERT(p);
1850 
1851 	switch (mode & S_IFMT) {
1852 	case S_IFCHR:
1853 	case S_IFBLK:
1854 		error = suser(td);
1855 		break;
1856 	default:
1857 		error = suser_cred(p->p_ucred, PRISON_ROOT);
1858 		break;
1859 	}
1860 	if (error)
1861 		return (error);
1862 
1863 	bwillinode(1);
1864 	nd->nl_flags |= NLC_CREATE | NLC_REFDVP;
1865 	if ((error = nlookup(nd)) != 0)
1866 		return (error);
1867 	if (nd->nl_nch.ncp->nc_vp)
1868 		return (EEXIST);
1869 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
1870 		return (error);
1871 
1872 	VATTR_NULL(&vattr);
1873 	vattr.va_mode = (mode & ALLPERMS) &~ p->p_fd->fd_cmask;
1874 	vattr.va_rmajor = rmajor;
1875 	vattr.va_rminor = rminor;
1876 	whiteout = 0;
1877 
1878 	switch (mode & S_IFMT) {
1879 	case S_IFMT:	/* used by badsect to flag bad sectors */
1880 		vattr.va_type = VBAD;
1881 		break;
1882 	case S_IFCHR:
1883 		vattr.va_type = VCHR;
1884 		break;
1885 	case S_IFBLK:
1886 		vattr.va_type = VBLK;
1887 		break;
1888 	case S_IFWHT:
1889 		whiteout = 1;
1890 		break;
1891 	case S_IFDIR:
1892 		/* special directories support for HAMMER */
1893 		vattr.va_type = VDIR;
1894 		break;
1895 	default:
1896 		error = EINVAL;
1897 		break;
1898 	}
1899 	if (error == 0) {
1900 		if (whiteout) {
1901 			error = VOP_NWHITEOUT(&nd->nl_nch, nd->nl_dvp,
1902 					      nd->nl_cred, NAMEI_CREATE);
1903 		} else {
1904 			vp = NULL;
1905 			error = VOP_NMKNOD(&nd->nl_nch, nd->nl_dvp,
1906 					   &vp, nd->nl_cred, &vattr);
1907 			if (error == 0)
1908 				vput(vp);
1909 		}
1910 	}
1911 	return (error);
1912 }
1913 
1914 /*
1915  * mknod_args(char *path, int mode, int dev)
1916  *
1917  * Create a special file.
1918  */
1919 int
1920 sys_mknod(struct mknod_args *uap)
1921 {
1922 	struct nlookupdata nd;
1923 	int error;
1924 
1925 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
1926 	if (error == 0) {
1927 		error = kern_mknod(&nd, uap->mode,
1928 				   umajor(uap->dev), uminor(uap->dev));
1929 	}
1930 	nlookup_done(&nd);
1931 	return (error);
1932 }
1933 
1934 int
1935 kern_mkfifo(struct nlookupdata *nd, int mode)
1936 {
1937 	struct thread *td = curthread;
1938 	struct proc *p = td->td_proc;
1939 	struct vattr vattr;
1940 	struct vnode *vp;
1941 	int error;
1942 
1943 	bwillinode(1);
1944 
1945 	nd->nl_flags |= NLC_CREATE | NLC_REFDVP;
1946 	if ((error = nlookup(nd)) != 0)
1947 		return (error);
1948 	if (nd->nl_nch.ncp->nc_vp)
1949 		return (EEXIST);
1950 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
1951 		return (error);
1952 
1953 	VATTR_NULL(&vattr);
1954 	vattr.va_type = VFIFO;
1955 	vattr.va_mode = (mode & ALLPERMS) &~ p->p_fd->fd_cmask;
1956 	vp = NULL;
1957 	error = VOP_NMKNOD(&nd->nl_nch, nd->nl_dvp, &vp, nd->nl_cred, &vattr);
1958 	if (error == 0)
1959 		vput(vp);
1960 	return (error);
1961 }
1962 
1963 /*
1964  * mkfifo_args(char *path, int mode)
1965  *
1966  * Create a named pipe.
1967  */
1968 int
1969 sys_mkfifo(struct mkfifo_args *uap)
1970 {
1971 	struct nlookupdata nd;
1972 	int error;
1973 
1974 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
1975 	if (error == 0)
1976 		error = kern_mkfifo(&nd, uap->mode);
1977 	nlookup_done(&nd);
1978 	return (error);
1979 }
1980 
1981 static int hardlink_check_uid = 0;
1982 SYSCTL_INT(_security, OID_AUTO, hardlink_check_uid, CTLFLAG_RW,
1983     &hardlink_check_uid, 0,
1984     "Unprivileged processes cannot create hard links to files owned by other "
1985     "users");
1986 static int hardlink_check_gid = 0;
1987 SYSCTL_INT(_security, OID_AUTO, hardlink_check_gid, CTLFLAG_RW,
1988     &hardlink_check_gid, 0,
1989     "Unprivileged processes cannot create hard links to files owned by other "
1990     "groups");
1991 
1992 static int
1993 can_hardlink(struct vnode *vp, struct thread *td, struct ucred *cred)
1994 {
1995 	struct vattr va;
1996 	int error;
1997 
1998 	/*
1999 	 * Shortcut if disabled
2000 	 */
2001 	if (hardlink_check_uid == 0 && hardlink_check_gid == 0)
2002 		return (0);
2003 
2004 	/*
2005 	 * root cred can always hardlink
2006 	 */
2007 	if (suser_cred(cred, PRISON_ROOT) == 0)
2008 		return (0);
2009 
2010 	/*
2011 	 * Otherwise only if the originating file is owned by the
2012 	 * same user or group.  Note that any group is allowed if
2013 	 * the file is owned by the caller.
2014 	 */
2015 	error = VOP_GETATTR(vp, &va);
2016 	if (error != 0)
2017 		return (error);
2018 
2019 	if (hardlink_check_uid) {
2020 		if (cred->cr_uid != va.va_uid)
2021 			return (EPERM);
2022 	}
2023 
2024 	if (hardlink_check_gid) {
2025 		if (cred->cr_uid != va.va_uid && !groupmember(va.va_gid, cred))
2026 			return (EPERM);
2027 	}
2028 
2029 	return (0);
2030 }
2031 
2032 int
2033 kern_link(struct nlookupdata *nd, struct nlookupdata *linknd)
2034 {
2035 	struct thread *td = curthread;
2036 	struct vnode *vp;
2037 	int error;
2038 
2039 	/*
2040 	 * Lookup the source and obtained a locked vnode.
2041 	 *
2042 	 * XXX relookup on vget failure / race ?
2043 	 */
2044 	bwillinode(1);
2045 	if ((error = nlookup(nd)) != 0)
2046 		return (error);
2047 	vp = nd->nl_nch.ncp->nc_vp;
2048 	KKASSERT(vp != NULL);
2049 	if (vp->v_type == VDIR)
2050 		return (EPERM);		/* POSIX */
2051 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2052 		return (error);
2053 	if ((error = vget(vp, LK_EXCLUSIVE)) != 0)
2054 		return (error);
2055 
2056 	/*
2057 	 * Unlock the source so we can lookup the target without deadlocking
2058 	 * (XXX vp is locked already, possible other deadlock?).  The target
2059 	 * must not exist.
2060 	 */
2061 	KKASSERT(nd->nl_flags & NLC_NCPISLOCKED);
2062 	nd->nl_flags &= ~NLC_NCPISLOCKED;
2063 	cache_unlock(&nd->nl_nch);
2064 
2065 	linknd->nl_flags |= NLC_CREATE | NLC_REFDVP;
2066 	if ((error = nlookup(linknd)) != 0) {
2067 		vput(vp);
2068 		return (error);
2069 	}
2070 	if (linknd->nl_nch.ncp->nc_vp) {
2071 		vput(vp);
2072 		return (EEXIST);
2073 	}
2074 
2075 	/*
2076 	 * Finally run the new API VOP.
2077 	 */
2078 	error = can_hardlink(vp, td, td->td_proc->p_ucred);
2079 	if (error == 0) {
2080 		error = VOP_NLINK(&linknd->nl_nch, linknd->nl_dvp,
2081 				  vp, linknd->nl_cred);
2082 	}
2083 	vput(vp);
2084 	return (error);
2085 }
2086 
2087 /*
2088  * link_args(char *path, char *link)
2089  *
2090  * Make a hard file link.
2091  */
2092 int
2093 sys_link(struct link_args *uap)
2094 {
2095 	struct nlookupdata nd, linknd;
2096 	int error;
2097 
2098 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2099 	if (error == 0) {
2100 		error = nlookup_init(&linknd, uap->link, UIO_USERSPACE, 0);
2101 		if (error == 0)
2102 			error = kern_link(&nd, &linknd);
2103 		nlookup_done(&linknd);
2104 	}
2105 	nlookup_done(&nd);
2106 	return (error);
2107 }
2108 
2109 int
2110 kern_symlink(struct nlookupdata *nd, char *path, int mode)
2111 {
2112 	struct vattr vattr;
2113 	struct vnode *vp;
2114 	struct vnode *dvp;
2115 	int error;
2116 
2117 	bwillinode(1);
2118 	nd->nl_flags |= NLC_CREATE | NLC_REFDVP;
2119 	if ((error = nlookup(nd)) != 0)
2120 		return (error);
2121 	if (nd->nl_nch.ncp->nc_vp)
2122 		return (EEXIST);
2123 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2124 		return (error);
2125 	dvp = nd->nl_dvp;
2126 	VATTR_NULL(&vattr);
2127 	vattr.va_mode = mode;
2128 	error = VOP_NSYMLINK(&nd->nl_nch, dvp, &vp, nd->nl_cred, &vattr, path);
2129 	if (error == 0)
2130 		vput(vp);
2131 	return (error);
2132 }
2133 
2134 /*
2135  * symlink(char *path, char *link)
2136  *
2137  * Make a symbolic link.
2138  */
2139 int
2140 sys_symlink(struct symlink_args *uap)
2141 {
2142 	struct thread *td = curthread;
2143 	struct nlookupdata nd;
2144 	char *path;
2145 	int error;
2146 	int mode;
2147 
2148 	path = objcache_get(namei_oc, M_WAITOK);
2149 	error = copyinstr(uap->path, path, MAXPATHLEN, NULL);
2150 	if (error == 0) {
2151 		error = nlookup_init(&nd, uap->link, UIO_USERSPACE, 0);
2152 		if (error == 0) {
2153 			mode = ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask;
2154 			error = kern_symlink(&nd, path, mode);
2155 		}
2156 		nlookup_done(&nd);
2157 	}
2158 	objcache_put(namei_oc, path);
2159 	return (error);
2160 }
2161 
2162 /*
2163  * undelete_args(char *path)
2164  *
2165  * Delete a whiteout from the filesystem.
2166  */
2167 /* ARGSUSED */
2168 int
2169 sys_undelete(struct undelete_args *uap)
2170 {
2171 	struct nlookupdata nd;
2172 	int error;
2173 
2174 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2175 	bwillinode(1);
2176 	nd.nl_flags |= NLC_DELETE | NLC_REFDVP;
2177 	if (error == 0)
2178 		error = nlookup(&nd);
2179 	if (error == 0)
2180 		error = ncp_writechk(&nd.nl_nch);
2181 	if (error == 0) {
2182 		error = VOP_NWHITEOUT(&nd.nl_nch, nd.nl_dvp, nd.nl_cred,
2183 				      NAMEI_DELETE);
2184 	}
2185 	nlookup_done(&nd);
2186 	return (error);
2187 }
2188 
2189 int
2190 kern_unlink(struct nlookupdata *nd)
2191 {
2192 	int error;
2193 
2194 	bwillinode(1);
2195 	nd->nl_flags |= NLC_DELETE | NLC_REFDVP;
2196 	if ((error = nlookup(nd)) != 0)
2197 		return (error);
2198 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2199 		return (error);
2200 	error = VOP_NREMOVE(&nd->nl_nch, nd->nl_dvp, nd->nl_cred);
2201 	return (error);
2202 }
2203 
2204 /*
2205  * unlink_args(char *path)
2206  *
2207  * Delete a name from the filesystem.
2208  */
2209 int
2210 sys_unlink(struct unlink_args *uap)
2211 {
2212 	struct nlookupdata nd;
2213 	int error;
2214 
2215 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2216 	if (error == 0)
2217 		error = kern_unlink(&nd);
2218 	nlookup_done(&nd);
2219 	return (error);
2220 }
2221 
2222 int
2223 kern_lseek(int fd, off_t offset, int whence, off_t *res)
2224 {
2225 	struct thread *td = curthread;
2226 	struct proc *p = td->td_proc;
2227 	struct file *fp;
2228 	struct vnode *vp;
2229 	struct vattr vattr;
2230 	off_t new_offset;
2231 	int error;
2232 
2233 	fp = holdfp(p->p_fd, fd, -1);
2234 	if (fp == NULL)
2235 		return (EBADF);
2236 	if (fp->f_type != DTYPE_VNODE) {
2237 		error = ESPIPE;
2238 		goto done;
2239 	}
2240 	vp = (struct vnode *)fp->f_data;
2241 
2242 	switch (whence) {
2243 	case L_INCR:
2244 		new_offset = fp->f_offset + offset;
2245 		error = 0;
2246 		break;
2247 	case L_XTND:
2248 		error = VOP_GETATTR(vp, &vattr);
2249 		new_offset = offset + vattr.va_size;
2250 		break;
2251 	case L_SET:
2252 		new_offset = offset;
2253 		error = 0;
2254 		break;
2255 	default:
2256 		new_offset = 0;
2257 		error = EINVAL;
2258 		break;
2259 	}
2260 
2261 	/*
2262 	 * Validate the seek position.  Negative offsets are not allowed
2263 	 * for regular files, block specials, or directories.
2264 	 */
2265 	if (error == 0) {
2266 		if (new_offset < 0 &&
2267 		    (vp->v_type == VREG || vp->v_type == VDIR ||
2268 		     vp->v_type == VCHR || vp->v_type == VBLK)) {
2269 			error = EINVAL;
2270 		} else {
2271 			fp->f_offset = new_offset;
2272 		}
2273 	}
2274 	*res = fp->f_offset;
2275 done:
2276 	fdrop(fp);
2277 	return (error);
2278 }
2279 
2280 /*
2281  * lseek_args(int fd, int pad, off_t offset, int whence)
2282  *
2283  * Reposition read/write file offset.
2284  */
2285 int
2286 sys_lseek(struct lseek_args *uap)
2287 {
2288 	int error;
2289 
2290 	error = kern_lseek(uap->fd, uap->offset, uap->whence,
2291 			   &uap->sysmsg_offset);
2292 
2293 	return (error);
2294 }
2295 
2296 int
2297 kern_access(struct nlookupdata *nd, int aflags)
2298 {
2299 	struct vnode *vp;
2300 	int error, flags;
2301 
2302 	if ((error = nlookup(nd)) != 0)
2303 		return (error);
2304 retry:
2305 	error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, &vp);
2306 	if (error)
2307 		return (error);
2308 
2309 	/* Flags == 0 means only check for existence. */
2310 	if (aflags) {
2311 		flags = 0;
2312 		if (aflags & R_OK)
2313 			flags |= VREAD;
2314 		if (aflags & W_OK)
2315 			flags |= VWRITE;
2316 		if (aflags & X_OK)
2317 			flags |= VEXEC;
2318 		if ((flags & VWRITE) == 0 ||
2319 		    (error = vn_writechk(vp, &nd->nl_nch)) == 0)
2320 			error = VOP_ACCESS(vp, flags, nd->nl_cred);
2321 
2322 		/*
2323 		 * If the file handle is stale we have to re-resolve the
2324 		 * entry.  This is a hack at the moment.
2325 		 */
2326 		if (error == ESTALE) {
2327 			vput(vp);
2328 			cache_setunresolved(&nd->nl_nch);
2329 			error = cache_resolve(&nd->nl_nch, nd->nl_cred);
2330 			if (error == 0) {
2331 				vp = NULL;
2332 				goto retry;
2333 			}
2334 			return(error);
2335 		}
2336 	}
2337 	vput(vp);
2338 	return (error);
2339 }
2340 
2341 /*
2342  * access_args(char *path, int flags)
2343  *
2344  * Check access permissions.
2345  */
2346 int
2347 sys_access(struct access_args *uap)
2348 {
2349 	struct nlookupdata nd;
2350 	int error;
2351 
2352 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2353 	if (error == 0)
2354 		error = kern_access(&nd, uap->flags);
2355 	nlookup_done(&nd);
2356 	return (error);
2357 }
2358 
2359 int
2360 kern_stat(struct nlookupdata *nd, struct stat *st)
2361 {
2362 	int error;
2363 	struct vnode *vp;
2364 	thread_t td;
2365 
2366 	if ((error = nlookup(nd)) != 0)
2367 		return (error);
2368 again:
2369 	if ((vp = nd->nl_nch.ncp->nc_vp) == NULL)
2370 		return (ENOENT);
2371 
2372 	td = curthread;
2373 	if ((error = vget(vp, LK_SHARED)) != 0)
2374 		return (error);
2375 	error = vn_stat(vp, st, nd->nl_cred);
2376 
2377 	/*
2378 	 * If the file handle is stale we have to re-resolve the entry.  This
2379 	 * is a hack at the moment.
2380 	 */
2381 	if (error == ESTALE) {
2382 		vput(vp);
2383 		cache_setunresolved(&nd->nl_nch);
2384 		error = cache_resolve(&nd->nl_nch, nd->nl_cred);
2385 		if (error == 0)
2386 			goto again;
2387 	} else {
2388 		vput(vp);
2389 	}
2390 	return (error);
2391 }
2392 
2393 /*
2394  * stat_args(char *path, struct stat *ub)
2395  *
2396  * Get file status; this version follows links.
2397  */
2398 int
2399 sys_stat(struct stat_args *uap)
2400 {
2401 	struct nlookupdata nd;
2402 	struct stat st;
2403 	int error;
2404 
2405 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2406 	if (error == 0) {
2407 		error = kern_stat(&nd, &st);
2408 		if (error == 0)
2409 			error = copyout(&st, uap->ub, sizeof(*uap->ub));
2410 	}
2411 	nlookup_done(&nd);
2412 	return (error);
2413 }
2414 
2415 /*
2416  * lstat_args(char *path, struct stat *ub)
2417  *
2418  * Get file status; this version does not follow links.
2419  */
2420 int
2421 sys_lstat(struct lstat_args *uap)
2422 {
2423 	struct nlookupdata nd;
2424 	struct stat st;
2425 	int error;
2426 
2427 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2428 	if (error == 0) {
2429 		error = kern_stat(&nd, &st);
2430 		if (error == 0)
2431 			error = copyout(&st, uap->ub, sizeof(*uap->ub));
2432 	}
2433 	nlookup_done(&nd);
2434 	return (error);
2435 }
2436 
2437 /*
2438  * pathconf_Args(char *path, int name)
2439  *
2440  * Get configurable pathname variables.
2441  */
2442 /* ARGSUSED */
2443 int
2444 sys_pathconf(struct pathconf_args *uap)
2445 {
2446 	struct nlookupdata nd;
2447 	struct vnode *vp;
2448 	int error;
2449 
2450 	vp = NULL;
2451 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2452 	if (error == 0)
2453 		error = nlookup(&nd);
2454 	if (error == 0)
2455 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
2456 	nlookup_done(&nd);
2457 	if (error == 0) {
2458 		error = VOP_PATHCONF(vp, uap->name, uap->sysmsg_fds);
2459 		vput(vp);
2460 	}
2461 	return (error);
2462 }
2463 
2464 /*
2465  * XXX: daver
2466  * kern_readlink isn't properly split yet.  There is a copyin burried
2467  * in VOP_READLINK().
2468  */
2469 int
2470 kern_readlink(struct nlookupdata *nd, char *buf, int count, int *res)
2471 {
2472 	struct thread *td = curthread;
2473 	struct proc *p = td->td_proc;
2474 	struct vnode *vp;
2475 	struct iovec aiov;
2476 	struct uio auio;
2477 	int error;
2478 
2479 	if ((error = nlookup(nd)) != 0)
2480 		return (error);
2481 	error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, &vp);
2482 	if (error)
2483 		return (error);
2484 	if (vp->v_type != VLNK) {
2485 		error = EINVAL;
2486 	} else {
2487 		aiov.iov_base = buf;
2488 		aiov.iov_len = count;
2489 		auio.uio_iov = &aiov;
2490 		auio.uio_iovcnt = 1;
2491 		auio.uio_offset = 0;
2492 		auio.uio_rw = UIO_READ;
2493 		auio.uio_segflg = UIO_USERSPACE;
2494 		auio.uio_td = td;
2495 		auio.uio_resid = count;
2496 		error = VOP_READLINK(vp, &auio, p->p_ucred);
2497 	}
2498 	vput(vp);
2499 	*res = count - auio.uio_resid;
2500 	return (error);
2501 }
2502 
2503 /*
2504  * readlink_args(char *path, char *buf, int count)
2505  *
2506  * Return target name of a symbolic link.
2507  */
2508 int
2509 sys_readlink(struct readlink_args *uap)
2510 {
2511 	struct nlookupdata nd;
2512 	int error;
2513 
2514 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2515 	if (error == 0) {
2516 		error = kern_readlink(&nd, uap->buf, uap->count,
2517 					&uap->sysmsg_result);
2518 	}
2519 	nlookup_done(&nd);
2520 	return (error);
2521 }
2522 
2523 static int
2524 setfflags(struct vnode *vp, int flags)
2525 {
2526 	struct thread *td = curthread;
2527 	struct proc *p = td->td_proc;
2528 	int error;
2529 	struct vattr vattr;
2530 
2531 	/*
2532 	 * Prevent non-root users from setting flags on devices.  When
2533 	 * a device is reused, users can retain ownership of the device
2534 	 * if they are allowed to set flags and programs assume that
2535 	 * chown can't fail when done as root.
2536 	 */
2537 	if ((vp->v_type == VCHR || vp->v_type == VBLK) &&
2538 	    ((error = suser_cred(p->p_ucred, PRISON_ROOT)) != 0))
2539 		return (error);
2540 
2541 	/*
2542 	 * note: vget is required for any operation that might mod the vnode
2543 	 * so VINACTIVE is properly cleared.
2544 	 */
2545 	if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
2546 		VATTR_NULL(&vattr);
2547 		vattr.va_flags = flags;
2548 		error = VOP_SETATTR(vp, &vattr, p->p_ucred);
2549 		vput(vp);
2550 	}
2551 	return (error);
2552 }
2553 
2554 /*
2555  * chflags(char *path, int flags)
2556  *
2557  * Change flags of a file given a path name.
2558  */
2559 /* ARGSUSED */
2560 int
2561 sys_chflags(struct chflags_args *uap)
2562 {
2563 	struct nlookupdata nd;
2564 	struct vnode *vp;
2565 	int error;
2566 
2567 	vp = NULL;
2568 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2569 	/* XXX Add NLC flag indicating modifying operation? */
2570 	if (error == 0)
2571 		error = nlookup(&nd);
2572 	if (error == 0)
2573 		error = ncp_writechk(&nd.nl_nch);
2574 	if (error == 0)
2575 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
2576 	nlookup_done(&nd);
2577 	if (error == 0) {
2578 		error = setfflags(vp, uap->flags);
2579 		vrele(vp);
2580 	}
2581 	return (error);
2582 }
2583 
2584 /*
2585  * fchflags_args(int fd, int flags)
2586  *
2587  * Change flags of a file given a file descriptor.
2588  */
2589 /* ARGSUSED */
2590 int
2591 sys_fchflags(struct fchflags_args *uap)
2592 {
2593 	struct thread *td = curthread;
2594 	struct proc *p = td->td_proc;
2595 	struct file *fp;
2596 	int error;
2597 
2598 	if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
2599 		return (error);
2600 	if (fp->f_nchandle.ncp)
2601 		error = ncp_writechk(&fp->f_nchandle);
2602 	if (error == 0)
2603 		error = setfflags((struct vnode *) fp->f_data, uap->flags);
2604 	fdrop(fp);
2605 	return (error);
2606 }
2607 
2608 static int
2609 setfmode(struct vnode *vp, int mode)
2610 {
2611 	struct thread *td = curthread;
2612 	struct proc *p = td->td_proc;
2613 	int error;
2614 	struct vattr vattr;
2615 
2616 	/*
2617 	 * note: vget is required for any operation that might mod the vnode
2618 	 * so VINACTIVE is properly cleared.
2619 	 */
2620 	if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
2621 		VATTR_NULL(&vattr);
2622 		vattr.va_mode = mode & ALLPERMS;
2623 		error = VOP_SETATTR(vp, &vattr, p->p_ucred);
2624 		vput(vp);
2625 	}
2626 	return error;
2627 }
2628 
2629 int
2630 kern_chmod(struct nlookupdata *nd, int mode)
2631 {
2632 	struct vnode *vp;
2633 	int error;
2634 
2635 	/* XXX Add NLC flag indicating modifying operation? */
2636 	if ((error = nlookup(nd)) != 0)
2637 		return (error);
2638 	if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
2639 		return (error);
2640 	if ((error = ncp_writechk(&nd->nl_nch)) == 0)
2641 		error = setfmode(vp, mode);
2642 	vrele(vp);
2643 	return (error);
2644 }
2645 
2646 /*
2647  * chmod_args(char *path, int mode)
2648  *
2649  * Change mode of a file given path name.
2650  */
2651 /* ARGSUSED */
2652 int
2653 sys_chmod(struct chmod_args *uap)
2654 {
2655 	struct nlookupdata nd;
2656 	int error;
2657 
2658 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2659 	if (error == 0)
2660 		error = kern_chmod(&nd, uap->mode);
2661 	nlookup_done(&nd);
2662 	return (error);
2663 }
2664 
2665 /*
2666  * lchmod_args(char *path, int mode)
2667  *
2668  * Change mode of a file given path name (don't follow links.)
2669  */
2670 /* ARGSUSED */
2671 int
2672 sys_lchmod(struct lchmod_args *uap)
2673 {
2674 	struct nlookupdata nd;
2675 	int error;
2676 
2677 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2678 	if (error == 0)
2679 		error = kern_chmod(&nd, uap->mode);
2680 	nlookup_done(&nd);
2681 	return (error);
2682 }
2683 
2684 /*
2685  * fchmod_args(int fd, int mode)
2686  *
2687  * Change mode of a file given a file descriptor.
2688  */
2689 /* ARGSUSED */
2690 int
2691 sys_fchmod(struct fchmod_args *uap)
2692 {
2693 	struct thread *td = curthread;
2694 	struct proc *p = td->td_proc;
2695 	struct file *fp;
2696 	int error;
2697 
2698 	if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
2699 		return (error);
2700 	if (fp->f_nchandle.ncp)
2701 		error = ncp_writechk(&fp->f_nchandle);
2702 	if (error == 0)
2703 		error = setfmode((struct vnode *)fp->f_data, uap->mode);
2704 	fdrop(fp);
2705 	return (error);
2706 }
2707 
2708 static int
2709 setfown(struct vnode *vp, uid_t uid, gid_t gid)
2710 {
2711 	struct thread *td = curthread;
2712 	struct proc *p = td->td_proc;
2713 	int error;
2714 	struct vattr vattr;
2715 
2716 	/*
2717 	 * note: vget is required for any operation that might mod the vnode
2718 	 * so VINACTIVE is properly cleared.
2719 	 */
2720 	if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
2721 		VATTR_NULL(&vattr);
2722 		vattr.va_uid = uid;
2723 		vattr.va_gid = gid;
2724 		error = VOP_SETATTR(vp, &vattr, p->p_ucred);
2725 		vput(vp);
2726 	}
2727 	return error;
2728 }
2729 
2730 int
2731 kern_chown(struct nlookupdata *nd, int uid, int gid)
2732 {
2733 	struct vnode *vp;
2734 	int error;
2735 
2736 	/* XXX Add NLC flag indicating modifying operation? */
2737 	if ((error = nlookup(nd)) != 0)
2738 		return (error);
2739 	if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
2740 		return (error);
2741 	if ((error = ncp_writechk(&nd->nl_nch)) == 0)
2742 		error = setfown(vp, uid, gid);
2743 	vrele(vp);
2744 	return (error);
2745 }
2746 
2747 /*
2748  * chown(char *path, int uid, int gid)
2749  *
2750  * Set ownership given a path name.
2751  */
2752 int
2753 sys_chown(struct chown_args *uap)
2754 {
2755 	struct nlookupdata nd;
2756 	int error;
2757 
2758 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2759 	if (error == 0)
2760 		error = kern_chown(&nd, uap->uid, uap->gid);
2761 	nlookup_done(&nd);
2762 	return (error);
2763 }
2764 
2765 /*
2766  * lchown_args(char *path, int uid, int gid)
2767  *
2768  * Set ownership given a path name, do not cross symlinks.
2769  */
2770 int
2771 sys_lchown(struct lchown_args *uap)
2772 {
2773 	struct nlookupdata nd;
2774 	int error;
2775 
2776 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2777 	if (error == 0)
2778 		error = kern_chown(&nd, uap->uid, uap->gid);
2779 	nlookup_done(&nd);
2780 	return (error);
2781 }
2782 
2783 /*
2784  * fchown_args(int fd, int uid, int gid)
2785  *
2786  * Set ownership given a file descriptor.
2787  */
2788 /* ARGSUSED */
2789 int
2790 sys_fchown(struct fchown_args *uap)
2791 {
2792 	struct thread *td = curthread;
2793 	struct proc *p = td->td_proc;
2794 	struct file *fp;
2795 	int error;
2796 
2797 	if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
2798 		return (error);
2799 	if (fp->f_nchandle.ncp)
2800 		error = ncp_writechk(&fp->f_nchandle);
2801 	if (error == 0)
2802 		error = setfown((struct vnode *)fp->f_data, uap->uid, uap->gid);
2803 	fdrop(fp);
2804 	return (error);
2805 }
2806 
2807 static int
2808 getutimes(const struct timeval *tvp, struct timespec *tsp)
2809 {
2810 	struct timeval tv[2];
2811 
2812 	if (tvp == NULL) {
2813 		microtime(&tv[0]);
2814 		TIMEVAL_TO_TIMESPEC(&tv[0], &tsp[0]);
2815 		tsp[1] = tsp[0];
2816 	} else {
2817 		TIMEVAL_TO_TIMESPEC(&tvp[0], &tsp[0]);
2818 		TIMEVAL_TO_TIMESPEC(&tvp[1], &tsp[1]);
2819 	}
2820 	return 0;
2821 }
2822 
2823 static int
2824 setutimes(struct vnode *vp, const struct timespec *ts, int nullflag)
2825 {
2826 	struct thread *td = curthread;
2827 	struct proc *p = td->td_proc;
2828 	int error;
2829 	struct vattr vattr;
2830 
2831 	/*
2832 	 * note: vget is required for any operation that might mod the vnode
2833 	 * so VINACTIVE is properly cleared.
2834 	 */
2835 	if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
2836 		VATTR_NULL(&vattr);
2837 		vattr.va_atime = ts[0];
2838 		vattr.va_mtime = ts[1];
2839 		if (nullflag)
2840 			vattr.va_vaflags |= VA_UTIMES_NULL;
2841 		error = VOP_SETATTR(vp, &vattr, p->p_ucred);
2842 		vput(vp);
2843 	}
2844 	return error;
2845 }
2846 
2847 int
2848 kern_utimes(struct nlookupdata *nd, struct timeval *tptr)
2849 {
2850 	struct timespec ts[2];
2851 	struct vnode *vp;
2852 	int error;
2853 
2854 	if ((error = getutimes(tptr, ts)) != 0)
2855 		return (error);
2856 	/* XXX Add NLC flag indicating modifying operation? */
2857 	if ((error = nlookup(nd)) != 0)
2858 		return (error);
2859 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2860 		return (error);
2861 	if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
2862 		return (error);
2863 	error = setutimes(vp, ts, tptr == NULL);
2864 	vrele(vp);
2865 	return (error);
2866 }
2867 
2868 /*
2869  * utimes_args(char *path, struct timeval *tptr)
2870  *
2871  * Set the access and modification times of a file.
2872  */
2873 int
2874 sys_utimes(struct utimes_args *uap)
2875 {
2876 	struct timeval tv[2];
2877 	struct nlookupdata nd;
2878 	int error;
2879 
2880 	if (uap->tptr) {
2881  		error = copyin(uap->tptr, tv, sizeof(tv));
2882 		if (error)
2883 			return (error);
2884 	}
2885 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2886 	if (error == 0)
2887 		error = kern_utimes(&nd, uap->tptr ? tv : NULL);
2888 	nlookup_done(&nd);
2889 	return (error);
2890 }
2891 
2892 /*
2893  * lutimes_args(char *path, struct timeval *tptr)
2894  *
2895  * Set the access and modification times of a file.
2896  */
2897 int
2898 sys_lutimes(struct lutimes_args *uap)
2899 {
2900 	struct timeval tv[2];
2901 	struct nlookupdata nd;
2902 	int error;
2903 
2904 	if (uap->tptr) {
2905 		error = copyin(uap->tptr, tv, sizeof(tv));
2906 		if (error)
2907 			return (error);
2908 	}
2909 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2910 	if (error == 0)
2911 		error = kern_utimes(&nd, uap->tptr ? tv : NULL);
2912 	nlookup_done(&nd);
2913 	return (error);
2914 }
2915 
2916 int
2917 kern_futimes(int fd, struct timeval *tptr)
2918 {
2919 	struct thread *td = curthread;
2920 	struct proc *p = td->td_proc;
2921 	struct timespec ts[2];
2922 	struct file *fp;
2923 	int error;
2924 
2925 	error = getutimes(tptr, ts);
2926 	if (error)
2927 		return (error);
2928 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
2929 		return (error);
2930 	if (fp->f_nchandle.ncp)
2931 		error = ncp_writechk(&fp->f_nchandle);
2932 	if (error == 0)
2933 		error =  setutimes((struct vnode *)fp->f_data, ts, tptr == NULL);
2934 	fdrop(fp);
2935 	return (error);
2936 }
2937 
2938 /*
2939  * futimes_args(int fd, struct timeval *tptr)
2940  *
2941  * Set the access and modification times of a file.
2942  */
2943 int
2944 sys_futimes(struct futimes_args *uap)
2945 {
2946 	struct timeval tv[2];
2947 	int error;
2948 
2949 	if (uap->tptr) {
2950 		error = copyin(uap->tptr, tv, sizeof(tv));
2951 		if (error)
2952 			return (error);
2953 	}
2954 
2955 	error = kern_futimes(uap->fd, uap->tptr ? tv : NULL);
2956 
2957 	return (error);
2958 }
2959 
2960 int
2961 kern_truncate(struct nlookupdata *nd, off_t length)
2962 {
2963 	struct vnode *vp;
2964 	struct vattr vattr;
2965 	int error;
2966 
2967 	if (length < 0)
2968 		return(EINVAL);
2969 	/* XXX Add NLC flag indicating modifying operation? */
2970 	if ((error = nlookup(nd)) != 0)
2971 		return (error);
2972 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2973 		return (error);
2974 	if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
2975 		return (error);
2976 	if ((error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY)) != 0) {
2977 		vrele(vp);
2978 		return (error);
2979 	}
2980 	if (vp->v_type == VDIR) {
2981 		error = EISDIR;
2982 	} else if ((error = vn_writechk(vp, &nd->nl_nch)) == 0 &&
2983 	    (error = VOP_ACCESS(vp, VWRITE, nd->nl_cred)) == 0) {
2984 		VATTR_NULL(&vattr);
2985 		vattr.va_size = length;
2986 		error = VOP_SETATTR(vp, &vattr, nd->nl_cred);
2987 	}
2988 	vput(vp);
2989 	return (error);
2990 }
2991 
2992 /*
2993  * truncate(char *path, int pad, off_t length)
2994  *
2995  * Truncate a file given its path name.
2996  */
2997 int
2998 sys_truncate(struct truncate_args *uap)
2999 {
3000 	struct nlookupdata nd;
3001 	int error;
3002 
3003 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3004 	if (error == 0)
3005 		error = kern_truncate(&nd, uap->length);
3006 	nlookup_done(&nd);
3007 	return error;
3008 }
3009 
3010 int
3011 kern_ftruncate(int fd, off_t length)
3012 {
3013 	struct thread *td = curthread;
3014 	struct proc *p = td->td_proc;
3015 	struct vattr vattr;
3016 	struct vnode *vp;
3017 	struct file *fp;
3018 	int error;
3019 
3020 	if (length < 0)
3021 		return(EINVAL);
3022 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
3023 		return (error);
3024 	if (fp->f_nchandle.ncp) {
3025 		error = ncp_writechk(&fp->f_nchandle);
3026 		if (error)
3027 			goto done;
3028 	}
3029 	if ((fp->f_flag & FWRITE) == 0) {
3030 		error = EINVAL;
3031 		goto done;
3032 	}
3033 	vp = (struct vnode *)fp->f_data;
3034 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3035 	if (vp->v_type == VDIR) {
3036 		error = EISDIR;
3037 	} else if ((error = vn_writechk(vp, NULL)) == 0) {
3038 		VATTR_NULL(&vattr);
3039 		vattr.va_size = length;
3040 		error = VOP_SETATTR(vp, &vattr, fp->f_cred);
3041 	}
3042 	vn_unlock(vp);
3043 done:
3044 	fdrop(fp);
3045 	return (error);
3046 }
3047 
3048 /*
3049  * ftruncate_args(int fd, int pad, off_t length)
3050  *
3051  * Truncate a file given a file descriptor.
3052  */
3053 int
3054 sys_ftruncate(struct ftruncate_args *uap)
3055 {
3056 	int error;
3057 
3058 	error = kern_ftruncate(uap->fd, uap->length);
3059 
3060 	return (error);
3061 }
3062 
3063 /*
3064  * fsync(int fd)
3065  *
3066  * Sync an open file.
3067  */
3068 /* ARGSUSED */
3069 int
3070 sys_fsync(struct fsync_args *uap)
3071 {
3072 	struct thread *td = curthread;
3073 	struct proc *p = td->td_proc;
3074 	struct vnode *vp;
3075 	struct file *fp;
3076 	vm_object_t obj;
3077 	int error;
3078 
3079 	if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
3080 		return (error);
3081 	vp = (struct vnode *)fp->f_data;
3082 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3083 	if ((obj = vp->v_object) != NULL)
3084 		vm_object_page_clean(obj, 0, 0, 0);
3085 	if ((error = VOP_FSYNC(vp, MNT_WAIT)) == 0 && vp->v_mount)
3086 		error = buf_fsync(vp);
3087 	vn_unlock(vp);
3088 	fdrop(fp);
3089 	return (error);
3090 }
3091 
3092 int
3093 kern_rename(struct nlookupdata *fromnd, struct nlookupdata *tond)
3094 {
3095 	struct nchandle fnchd;
3096 	struct nchandle tnchd;
3097 	struct namecache *ncp;
3098 	struct vnode *fdvp;
3099 	struct vnode *tdvp;
3100 	struct mount *mp;
3101 	int error;
3102 
3103 	bwillinode(1);
3104 	fromnd->nl_flags |= NLC_REFDVP;
3105 	if ((error = nlookup(fromnd)) != 0)
3106 		return (error);
3107 	if ((fnchd.ncp = fromnd->nl_nch.ncp->nc_parent) == NULL)
3108 		return (ENOENT);
3109 	fnchd.mount = fromnd->nl_nch.mount;
3110 	cache_hold(&fnchd);
3111 
3112 	/*
3113 	 * unlock the source nch so we can lookup the target nch without
3114 	 * deadlocking.  The target may or may not exist so we do not check
3115 	 * for a target vp like kern_mkdir() and other creation functions do.
3116 	 *
3117 	 * The source and target directories are ref'd and rechecked after
3118 	 * everything is relocked to determine if the source or target file
3119 	 * has been renamed.
3120 	 */
3121 	KKASSERT(fromnd->nl_flags & NLC_NCPISLOCKED);
3122 	fromnd->nl_flags &= ~NLC_NCPISLOCKED;
3123 	cache_unlock(&fromnd->nl_nch);
3124 
3125 	tond->nl_flags |= NLC_CREATE | NLC_REFDVP;
3126 	if ((error = nlookup(tond)) != 0) {
3127 		cache_drop(&fnchd);
3128 		return (error);
3129 	}
3130 	if ((tnchd.ncp = tond->nl_nch.ncp->nc_parent) == NULL) {
3131 		cache_drop(&fnchd);
3132 		return (ENOENT);
3133 	}
3134 	tnchd.mount = tond->nl_nch.mount;
3135 	cache_hold(&tnchd);
3136 
3137 	/*
3138 	 * If the source and target are the same there is nothing to do
3139 	 */
3140 	if (fromnd->nl_nch.ncp == tond->nl_nch.ncp) {
3141 		cache_drop(&fnchd);
3142 		cache_drop(&tnchd);
3143 		return (0);
3144 	}
3145 
3146 	/*
3147 	 * Mount points cannot be renamed or overwritten
3148 	 */
3149 	if ((fromnd->nl_nch.ncp->nc_flag | tond->nl_nch.ncp->nc_flag) &
3150 	    NCF_ISMOUNTPT
3151 	) {
3152 		cache_drop(&fnchd);
3153 		cache_drop(&tnchd);
3154 		return (EINVAL);
3155 	}
3156 
3157 	/*
3158 	 * relock the source ncp.  NOTE AFTER RELOCKING: the source ncp
3159 	 * may have become invalid while it was unlocked, nc_vp and nc_mount
3160 	 * could be NULL.
3161 	 */
3162 	if (cache_lock_nonblock(&fromnd->nl_nch) == 0) {
3163 		cache_resolve(&fromnd->nl_nch, fromnd->nl_cred);
3164 	} else if (fromnd->nl_nch.ncp > tond->nl_nch.ncp) {
3165 		cache_lock(&fromnd->nl_nch);
3166 		cache_resolve(&fromnd->nl_nch, fromnd->nl_cred);
3167 	} else {
3168 		cache_unlock(&tond->nl_nch);
3169 		cache_lock(&fromnd->nl_nch);
3170 		cache_resolve(&fromnd->nl_nch, fromnd->nl_cred);
3171 		cache_lock(&tond->nl_nch);
3172 		cache_resolve(&tond->nl_nch, tond->nl_cred);
3173 	}
3174 	fromnd->nl_flags |= NLC_NCPISLOCKED;
3175 
3176 	/*
3177 	 * make sure the parent directories linkages are the same
3178 	 */
3179 	if (fnchd.ncp != fromnd->nl_nch.ncp->nc_parent ||
3180 	    tnchd.ncp != tond->nl_nch.ncp->nc_parent) {
3181 		cache_drop(&fnchd);
3182 		cache_drop(&tnchd);
3183 		return (ENOENT);
3184 	}
3185 
3186 	/*
3187 	 * Both the source and target must be within the same filesystem and
3188 	 * in the same filesystem as their parent directories within the
3189 	 * namecache topology.
3190 	 *
3191 	 * NOTE: fromnd's nc_mount or nc_vp could be NULL.
3192 	 */
3193 	mp = fnchd.mount;
3194 	if (mp != tnchd.mount || mp != fromnd->nl_nch.mount ||
3195 	    mp != tond->nl_nch.mount) {
3196 		cache_drop(&fnchd);
3197 		cache_drop(&tnchd);
3198 		return (EXDEV);
3199 	}
3200 
3201 	/*
3202 	 * Make sure the mount point is writable
3203 	 */
3204 	if ((error = ncp_writechk(&tond->nl_nch)) != 0) {
3205 		cache_drop(&fnchd);
3206 		cache_drop(&tnchd);
3207 		return (error);
3208 	}
3209 
3210 	/*
3211 	 * If the target exists and either the source or target is a directory,
3212 	 * then both must be directories.
3213 	 *
3214 	 * Due to relocking of the source, fromnd->nl_nch.ncp->nc_vp might h
3215 	 * have become NULL.
3216 	 */
3217 	if (tond->nl_nch.ncp->nc_vp) {
3218 		if (fromnd->nl_nch.ncp->nc_vp == NULL) {
3219 			error = ENOENT;
3220 		} else if (fromnd->nl_nch.ncp->nc_vp->v_type == VDIR) {
3221 			if (tond->nl_nch.ncp->nc_vp->v_type != VDIR)
3222 				error = ENOTDIR;
3223 		} else if (tond->nl_nch.ncp->nc_vp->v_type == VDIR) {
3224 			error = EISDIR;
3225 		}
3226 	}
3227 
3228 	/*
3229 	 * You cannot rename a source into itself or a subdirectory of itself.
3230 	 * We check this by travsersing the target directory upwards looking
3231 	 * for a match against the source.
3232 	 */
3233 	if (error == 0) {
3234 		for (ncp = tnchd.ncp; ncp; ncp = ncp->nc_parent) {
3235 			if (fromnd->nl_nch.ncp == ncp) {
3236 				error = EINVAL;
3237 				break;
3238 			}
3239 		}
3240 	}
3241 
3242 	cache_drop(&fnchd);
3243 	cache_drop(&tnchd);
3244 
3245 	/*
3246 	 * Even though the namespaces are different, they may still represent
3247 	 * hardlinks to the same file.  The filesystem might have a hard time
3248 	 * with this so we issue a NREMOVE of the source instead of a NRENAME
3249 	 * when we detect the situation.
3250 	 */
3251 	if (error == 0) {
3252 		fdvp = fromnd->nl_dvp;
3253 		tdvp = tond->nl_dvp;
3254 		if (fdvp == NULL || tdvp == NULL) {
3255 			error = EPERM;
3256 		} else if (fromnd->nl_nch.ncp->nc_vp == tond->nl_nch.ncp->nc_vp) {
3257 			error = VOP_NREMOVE(&fromnd->nl_nch, fdvp,
3258 					    fromnd->nl_cred);
3259 		} else {
3260 			error = VOP_NRENAME(&fromnd->nl_nch, &tond->nl_nch,
3261 					    fdvp, tdvp, tond->nl_cred);
3262 		}
3263 	}
3264 	return (error);
3265 }
3266 
3267 /*
3268  * rename_args(char *from, char *to)
3269  *
3270  * Rename files.  Source and destination must either both be directories,
3271  * or both not be directories.  If target is a directory, it must be empty.
3272  */
3273 int
3274 sys_rename(struct rename_args *uap)
3275 {
3276 	struct nlookupdata fromnd, tond;
3277 	int error;
3278 
3279 	error = nlookup_init(&fromnd, uap->from, UIO_USERSPACE, 0);
3280 	if (error == 0) {
3281 		error = nlookup_init(&tond, uap->to, UIO_USERSPACE, 0);
3282 		if (error == 0)
3283 			error = kern_rename(&fromnd, &tond);
3284 		nlookup_done(&tond);
3285 	}
3286 	nlookup_done(&fromnd);
3287 	return (error);
3288 }
3289 
3290 int
3291 kern_mkdir(struct nlookupdata *nd, int mode)
3292 {
3293 	struct thread *td = curthread;
3294 	struct proc *p = td->td_proc;
3295 	struct vnode *vp;
3296 	struct vattr vattr;
3297 	int error;
3298 
3299 	bwillinode(1);
3300 	nd->nl_flags |= NLC_WILLBEDIR | NLC_CREATE | NLC_REFDVP;
3301 	if ((error = nlookup(nd)) != 0)
3302 		return (error);
3303 
3304 	if (nd->nl_nch.ncp->nc_vp)
3305 		return (EEXIST);
3306 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
3307 		return (error);
3308 	VATTR_NULL(&vattr);
3309 	vattr.va_type = VDIR;
3310 	vattr.va_mode = (mode & ACCESSPERMS) &~ p->p_fd->fd_cmask;
3311 
3312 	vp = NULL;
3313 	error = VOP_NMKDIR(&nd->nl_nch, nd->nl_dvp, &vp, p->p_ucred, &vattr);
3314 	if (error == 0)
3315 		vput(vp);
3316 	return (error);
3317 }
3318 
3319 /*
3320  * mkdir_args(char *path, int mode)
3321  *
3322  * Make a directory file.
3323  */
3324 /* ARGSUSED */
3325 int
3326 sys_mkdir(struct mkdir_args *uap)
3327 {
3328 	struct nlookupdata nd;
3329 	int error;
3330 
3331 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
3332 	if (error == 0)
3333 		error = kern_mkdir(&nd, uap->mode);
3334 	nlookup_done(&nd);
3335 	return (error);
3336 }
3337 
3338 int
3339 kern_rmdir(struct nlookupdata *nd)
3340 {
3341 	int error;
3342 
3343 	bwillinode(1);
3344 	nd->nl_flags |= NLC_DELETE | NLC_REFDVP;
3345 	if ((error = nlookup(nd)) != 0)
3346 		return (error);
3347 
3348 	/*
3349 	 * Do not allow directories representing mount points to be
3350 	 * deleted, even if empty.  Check write perms on mount point
3351 	 * in case the vnode is aliased (aka nullfs).
3352 	 */
3353 	if (nd->nl_nch.ncp->nc_flag & (NCF_ISMOUNTPT))
3354 		return (EINVAL);
3355 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
3356 		return (error);
3357 	error = VOP_NRMDIR(&nd->nl_nch, nd->nl_dvp, nd->nl_cred);
3358 	return (error);
3359 }
3360 
3361 /*
3362  * rmdir_args(char *path)
3363  *
3364  * Remove a directory file.
3365  */
3366 /* ARGSUSED */
3367 int
3368 sys_rmdir(struct rmdir_args *uap)
3369 {
3370 	struct nlookupdata nd;
3371 	int error;
3372 
3373 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
3374 	if (error == 0)
3375 		error = kern_rmdir(&nd);
3376 	nlookup_done(&nd);
3377 	return (error);
3378 }
3379 
3380 int
3381 kern_getdirentries(int fd, char *buf, u_int count, long *basep, int *res,
3382     enum uio_seg direction)
3383 {
3384 	struct thread *td = curthread;
3385 	struct proc *p = td->td_proc;
3386 	struct vnode *vp;
3387 	struct file *fp;
3388 	struct uio auio;
3389 	struct iovec aiov;
3390 	off_t loff;
3391 	int error, eofflag;
3392 
3393 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
3394 		return (error);
3395 	if ((fp->f_flag & FREAD) == 0) {
3396 		error = EBADF;
3397 		goto done;
3398 	}
3399 	vp = (struct vnode *)fp->f_data;
3400 unionread:
3401 	if (vp->v_type != VDIR) {
3402 		error = EINVAL;
3403 		goto done;
3404 	}
3405 	aiov.iov_base = buf;
3406 	aiov.iov_len = count;
3407 	auio.uio_iov = &aiov;
3408 	auio.uio_iovcnt = 1;
3409 	auio.uio_rw = UIO_READ;
3410 	auio.uio_segflg = direction;
3411 	auio.uio_td = td;
3412 	auio.uio_resid = count;
3413 	loff = auio.uio_offset = fp->f_offset;
3414 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL, NULL);
3415 	fp->f_offset = auio.uio_offset;
3416 	if (error)
3417 		goto done;
3418 	if (count == auio.uio_resid) {
3419 		if (union_dircheckp) {
3420 			error = union_dircheckp(td, &vp, fp);
3421 			if (error == -1)
3422 				goto unionread;
3423 			if (error)
3424 				goto done;
3425 		}
3426 #if 0
3427 		if ((vp->v_flag & VROOT) &&
3428 		    (vp->v_mount->mnt_flag & MNT_UNION)) {
3429 			struct vnode *tvp = vp;
3430 			vp = vp->v_mount->mnt_vnodecovered;
3431 			vref(vp);
3432 			fp->f_data = vp;
3433 			fp->f_offset = 0;
3434 			vrele(tvp);
3435 			goto unionread;
3436 		}
3437 #endif
3438 	}
3439 
3440 	/*
3441 	 * WARNING!  *basep may not be wide enough to accomodate the
3442 	 * seek offset.   XXX should we hack this to return the upper 32 bits
3443 	 * for offsets greater then 4G?
3444 	 */
3445 	if (basep) {
3446 		*basep = (long)loff;
3447 	}
3448 	*res = count - auio.uio_resid;
3449 done:
3450 	fdrop(fp);
3451 	return (error);
3452 }
3453 
3454 /*
3455  * getdirentries_args(int fd, char *buf, u_int conut, long *basep)
3456  *
3457  * Read a block of directory entries in a file system independent format.
3458  */
3459 int
3460 sys_getdirentries(struct getdirentries_args *uap)
3461 {
3462 	long base;
3463 	int error;
3464 
3465 	error = kern_getdirentries(uap->fd, uap->buf, uap->count, &base,
3466 				   &uap->sysmsg_result, UIO_USERSPACE);
3467 
3468 	if (error == 0 && uap->basep)
3469 		error = copyout(&base, uap->basep, sizeof(*uap->basep));
3470 	return (error);
3471 }
3472 
3473 /*
3474  * getdents_args(int fd, char *buf, size_t count)
3475  */
3476 int
3477 sys_getdents(struct getdents_args *uap)
3478 {
3479 	int error;
3480 
3481 	error = kern_getdirentries(uap->fd, uap->buf, uap->count, NULL,
3482 	    &uap->sysmsg_result, UIO_USERSPACE);
3483 
3484 	return (error);
3485 }
3486 
3487 /*
3488  * umask(int newmask)
3489  *
3490  * Set the mode mask for creation of filesystem nodes.
3491  *
3492  * MP SAFE
3493  */
3494 int
3495 sys_umask(struct umask_args *uap)
3496 {
3497 	struct thread *td = curthread;
3498 	struct proc *p = td->td_proc;
3499 	struct filedesc *fdp;
3500 
3501 	fdp = p->p_fd;
3502 	uap->sysmsg_result = fdp->fd_cmask;
3503 	fdp->fd_cmask = uap->newmask & ALLPERMS;
3504 	return (0);
3505 }
3506 
3507 /*
3508  * revoke(char *path)
3509  *
3510  * Void all references to file by ripping underlying filesystem
3511  * away from vnode.
3512  */
3513 /* ARGSUSED */
3514 int
3515 sys_revoke(struct revoke_args *uap)
3516 {
3517 	struct nlookupdata nd;
3518 	struct vattr vattr;
3519 	struct vnode *vp;
3520 	struct ucred *cred;
3521 	int error;
3522 
3523 	vp = NULL;
3524 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3525 	if (error == 0)
3526 		error = nlookup(&nd);
3527 	if (error == 0)
3528 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
3529 	cred = crhold(nd.nl_cred);
3530 	nlookup_done(&nd);
3531 	if (error == 0) {
3532 		if (vp->v_type != VCHR && vp->v_type != VBLK)
3533 			error = EINVAL;
3534 		if (error == 0)
3535 			error = VOP_GETATTR(vp, &vattr);
3536 		if (error == 0 && cred->cr_uid != vattr.va_uid)
3537 			error = suser_cred(cred, PRISON_ROOT);
3538 		if (error == 0 && count_udev(vp->v_umajor, vp->v_uminor) > 0) {
3539 			error = 0;
3540 			vx_lock(vp);
3541 			VOP_REVOKE(vp, REVOKEALL);
3542 			vx_unlock(vp);
3543 		}
3544 		vrele(vp);
3545 	}
3546 	if (cred)
3547 		crfree(cred);
3548 	return (error);
3549 }
3550 
3551 /*
3552  * getfh_args(char *fname, fhandle_t *fhp)
3553  *
3554  * Get (NFS) file handle
3555  */
3556 int
3557 sys_getfh(struct getfh_args *uap)
3558 {
3559 	struct thread *td = curthread;
3560 	struct nlookupdata nd;
3561 	fhandle_t fh;
3562 	struct vnode *vp;
3563 	int error;
3564 
3565 	/*
3566 	 * Must be super user
3567 	 */
3568 	if ((error = suser(td)) != 0)
3569 		return (error);
3570 
3571 	vp = NULL;
3572 	error = nlookup_init(&nd, uap->fname, UIO_USERSPACE, NLC_FOLLOW);
3573 	if (error == 0)
3574 		error = nlookup(&nd);
3575 	if (error == 0)
3576 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
3577 	nlookup_done(&nd);
3578 	if (error == 0) {
3579 		bzero(&fh, sizeof(fh));
3580 		fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
3581 		error = VFS_VPTOFH(vp, &fh.fh_fid);
3582 		vput(vp);
3583 		if (error == 0)
3584 			error = copyout(&fh, uap->fhp, sizeof(fh));
3585 	}
3586 	return (error);
3587 }
3588 
3589 /*
3590  * fhopen_args(const struct fhandle *u_fhp, int flags)
3591  *
3592  * syscall for the rpc.lockd to use to translate a NFS file handle into
3593  * an open descriptor.
3594  *
3595  * warning: do not remove the suser() call or this becomes one giant
3596  * security hole.
3597  */
3598 int
3599 sys_fhopen(struct fhopen_args *uap)
3600 {
3601 	struct thread *td = curthread;
3602 	struct proc *p = td->td_proc;
3603 	struct mount *mp;
3604 	struct vnode *vp;
3605 	struct fhandle fhp;
3606 	struct vattr vat;
3607 	struct vattr *vap = &vat;
3608 	struct flock lf;
3609 	int fmode, mode, error, type;
3610 	struct file *nfp;
3611 	struct file *fp;
3612 	int indx;
3613 
3614 	/*
3615 	 * Must be super user
3616 	 */
3617 	error = suser(td);
3618 	if (error)
3619 		return (error);
3620 
3621 	fmode = FFLAGS(uap->flags);
3622 	/* why not allow a non-read/write open for our lockd? */
3623 	if (((fmode & (FREAD | FWRITE)) == 0) || (fmode & O_CREAT))
3624 		return (EINVAL);
3625 	error = copyin(uap->u_fhp, &fhp, sizeof(fhp));
3626 	if (error)
3627 		return(error);
3628 	/* find the mount point */
3629 	mp = vfs_getvfs(&fhp.fh_fsid);
3630 	if (mp == NULL)
3631 		return (ESTALE);
3632 	/* now give me my vnode, it gets returned to me locked */
3633 	error = VFS_FHTOVP(mp, &fhp.fh_fid, &vp);
3634 	if (error)
3635 		return (error);
3636  	/*
3637 	 * from now on we have to make sure not
3638 	 * to forget about the vnode
3639 	 * any error that causes an abort must vput(vp)
3640 	 * just set error = err and 'goto bad;'.
3641 	 */
3642 
3643 	/*
3644 	 * from vn_open
3645 	 */
3646 	if (vp->v_type == VLNK) {
3647 		error = EMLINK;
3648 		goto bad;
3649 	}
3650 	if (vp->v_type == VSOCK) {
3651 		error = EOPNOTSUPP;
3652 		goto bad;
3653 	}
3654 	mode = 0;
3655 	if (fmode & (FWRITE | O_TRUNC)) {
3656 		if (vp->v_type == VDIR) {
3657 			error = EISDIR;
3658 			goto bad;
3659 		}
3660 		error = vn_writechk(vp, NULL);
3661 		if (error)
3662 			goto bad;
3663 		mode |= VWRITE;
3664 	}
3665 	if (fmode & FREAD)
3666 		mode |= VREAD;
3667 	if (mode) {
3668 		error = VOP_ACCESS(vp, mode, p->p_ucred);
3669 		if (error)
3670 			goto bad;
3671 	}
3672 	if (fmode & O_TRUNC) {
3673 		vn_unlock(vp);				/* XXX */
3674 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);	/* XXX */
3675 		VATTR_NULL(vap);
3676 		vap->va_size = 0;
3677 		error = VOP_SETATTR(vp, vap, p->p_ucred);
3678 		if (error)
3679 			goto bad;
3680 	}
3681 
3682 	/*
3683 	 * VOP_OPEN needs the file pointer so it can potentially override
3684 	 * it.
3685 	 *
3686 	 * WARNING! no f_nchandle will be associated when fhopen()ing a
3687 	 * directory.  XXX
3688 	 */
3689 	if ((error = falloc(p, &nfp, &indx)) != 0)
3690 		goto bad;
3691 	fp = nfp;
3692 
3693 	error = VOP_OPEN(vp, fmode, p->p_ucred, fp);
3694 	if (error) {
3695 		/*
3696 		 * setting f_ops this way prevents VOP_CLOSE from being
3697 		 * called or fdrop() releasing the vp from v_data.   Since
3698 		 * the VOP_OPEN failed we don't want to VOP_CLOSE.
3699 		 */
3700 		fp->f_ops = &badfileops;
3701 		fp->f_data = NULL;
3702 		goto bad_drop;
3703 	}
3704 
3705 	/*
3706 	 * The fp is given its own reference, we still have our ref and lock.
3707 	 *
3708 	 * Assert that all regular files must be created with a VM object.
3709 	 */
3710 	if (vp->v_type == VREG && vp->v_object == NULL) {
3711 		kprintf("fhopen: regular file did not have VM object: %p\n", vp);
3712 		goto bad_drop;
3713 	}
3714 
3715 	/*
3716 	 * The open was successful.  Handle any locking requirements.
3717 	 */
3718 	if (fmode & (O_EXLOCK | O_SHLOCK)) {
3719 		lf.l_whence = SEEK_SET;
3720 		lf.l_start = 0;
3721 		lf.l_len = 0;
3722 		if (fmode & O_EXLOCK)
3723 			lf.l_type = F_WRLCK;
3724 		else
3725 			lf.l_type = F_RDLCK;
3726 		if (fmode & FNONBLOCK)
3727 			type = 0;
3728 		else
3729 			type = F_WAIT;
3730 		vn_unlock(vp);
3731 		if ((error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type)) != 0) {
3732 			/*
3733 			 * release our private reference.
3734 			 */
3735 			fsetfd(p, NULL, indx);
3736 			fdrop(fp);
3737 			vrele(vp);
3738 			return (error);
3739 		}
3740 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3741 		fp->f_flag |= FHASLOCK;
3742 	}
3743 
3744 	/*
3745 	 * Clean up.  Associate the file pointer with the previously
3746 	 * reserved descriptor and return it.
3747 	 */
3748 	vput(vp);
3749 	fsetfd(p, fp, indx);
3750 	fdrop(fp);
3751 	uap->sysmsg_result = indx;
3752 	return (0);
3753 
3754 bad_drop:
3755 	fsetfd(p, NULL, indx);
3756 	fdrop(fp);
3757 bad:
3758 	vput(vp);
3759 	return (error);
3760 }
3761 
3762 /*
3763  * fhstat_args(struct fhandle *u_fhp, struct stat *sb)
3764  */
3765 int
3766 sys_fhstat(struct fhstat_args *uap)
3767 {
3768 	struct thread *td = curthread;
3769 	struct stat sb;
3770 	fhandle_t fh;
3771 	struct mount *mp;
3772 	struct vnode *vp;
3773 	int error;
3774 
3775 	/*
3776 	 * Must be super user
3777 	 */
3778 	error = suser(td);
3779 	if (error)
3780 		return (error);
3781 
3782 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
3783 	if (error)
3784 		return (error);
3785 
3786 	if ((mp = vfs_getvfs(&fh.fh_fsid)) == NULL)
3787 		return (ESTALE);
3788 	if ((error = VFS_FHTOVP(mp, &fh.fh_fid, &vp)))
3789 		return (error);
3790 	error = vn_stat(vp, &sb, td->td_proc->p_ucred);
3791 	vput(vp);
3792 	if (error)
3793 		return (error);
3794 	error = copyout(&sb, uap->sb, sizeof(sb));
3795 	return (error);
3796 }
3797 
3798 /*
3799  * fhstatfs_args(struct fhandle *u_fhp, struct statfs *buf)
3800  */
3801 int
3802 sys_fhstatfs(struct fhstatfs_args *uap)
3803 {
3804 	struct thread *td = curthread;
3805 	struct proc *p = td->td_proc;
3806 	struct statfs *sp;
3807 	struct mount *mp;
3808 	struct vnode *vp;
3809 	struct statfs sb;
3810 	char *fullpath, *freepath;
3811 	fhandle_t fh;
3812 	int error;
3813 
3814 	/*
3815 	 * Must be super user
3816 	 */
3817 	if ((error = suser(td)))
3818 		return (error);
3819 
3820 	if ((error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t))) != 0)
3821 		return (error);
3822 
3823 	if ((mp = vfs_getvfs(&fh.fh_fsid)) == NULL)
3824 		return (ESTALE);
3825 
3826 	if (p != NULL && !chroot_visible_mnt(mp, p))
3827 		return (ESTALE);
3828 
3829 	if ((error = VFS_FHTOVP(mp, &fh.fh_fid, &vp)))
3830 		return (error);
3831 	mp = vp->v_mount;
3832 	sp = &mp->mnt_stat;
3833 	vput(vp);
3834 	if ((error = VFS_STATFS(mp, sp, p->p_ucred)) != 0)
3835 		return (error);
3836 
3837 	error = mount_path(p, mp, &fullpath, &freepath);
3838 	if (error)
3839 		return(error);
3840 	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
3841 	strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
3842 	kfree(freepath, M_TEMP);
3843 
3844 	sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
3845 	if (suser(td)) {
3846 		bcopy(sp, &sb, sizeof(sb));
3847 		sb.f_fsid.val[0] = sb.f_fsid.val[1] = 0;
3848 		sp = &sb;
3849 	}
3850 	return (copyout(sp, uap->buf, sizeof(*sp)));
3851 }
3852 
3853 /*
3854  * fhstatvfs_args(struct fhandle *u_fhp, struct statvfs *buf)
3855  */
3856 int
3857 sys_fhstatvfs(struct fhstatvfs_args *uap)
3858 {
3859 	struct thread *td = curthread;
3860 	struct proc *p = td->td_proc;
3861 	struct statvfs *sp;
3862 	struct mount *mp;
3863 	struct vnode *vp;
3864 	fhandle_t fh;
3865 	int error;
3866 
3867 	/*
3868 	 * Must be super user
3869 	 */
3870 	if ((error = suser(td)))
3871 		return (error);
3872 
3873 	if ((error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t))) != 0)
3874 		return (error);
3875 
3876 	if ((mp = vfs_getvfs(&fh.fh_fsid)) == NULL)
3877 		return (ESTALE);
3878 
3879 	if (p != NULL && !chroot_visible_mnt(mp, p))
3880 		return (ESTALE);
3881 
3882 	if ((error = VFS_FHTOVP(mp, &fh.fh_fid, &vp)))
3883 		return (error);
3884 	mp = vp->v_mount;
3885 	sp = &mp->mnt_vstat;
3886 	vput(vp);
3887 	if ((error = VFS_STATVFS(mp, sp, p->p_ucred)) != 0)
3888 		return (error);
3889 
3890 	sp->f_flag = 0;
3891 	if (mp->mnt_flag & MNT_RDONLY)
3892 		sp->f_flag |= ST_RDONLY;
3893 	if (mp->mnt_flag & MNT_NOSUID)
3894 		sp->f_flag |= ST_NOSUID;
3895 
3896 	return (copyout(sp, uap->buf, sizeof(*sp)));
3897 }
3898 
3899 
3900 /*
3901  * Syscall to push extended attribute configuration information into the
3902  * VFS.  Accepts a path, which it converts to a mountpoint, as well as
3903  * a command (int cmd), and attribute name and misc data.  For now, the
3904  * attribute name is left in userspace for consumption by the VFS_op.
3905  * It will probably be changed to be copied into sysspace by the
3906  * syscall in the future, once issues with various consumers of the
3907  * attribute code have raised their hands.
3908  *
3909  * Currently this is used only by UFS Extended Attributes.
3910  */
3911 int
3912 sys_extattrctl(struct extattrctl_args *uap)
3913 {
3914 	struct nlookupdata nd;
3915 	struct mount *mp;
3916 	struct vnode *vp;
3917 	int error;
3918 
3919 	vp = NULL;
3920 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3921 	if (error == 0)
3922 		error = nlookup(&nd);
3923 	if (error == 0) {
3924 		mp = nd.nl_nch.mount;
3925 		error = VFS_EXTATTRCTL(mp, uap->cmd,
3926 				uap->attrname, uap->arg,
3927 				nd.nl_cred);
3928 	}
3929 	nlookup_done(&nd);
3930 	return (error);
3931 }
3932 
3933 /*
3934  * Syscall to set a named extended attribute on a file or directory.
3935  * Accepts attribute name, and a uio structure pointing to the data to set.
3936  * The uio is consumed in the style of writev().  The real work happens
3937  * in VOP_SETEXTATTR().
3938  */
3939 int
3940 sys_extattr_set_file(struct extattr_set_file_args *uap)
3941 {
3942 	char attrname[EXTATTR_MAXNAMELEN];
3943 	struct iovec aiov[UIO_SMALLIOV];
3944 	struct iovec *needfree;
3945 	struct nlookupdata nd;
3946 	struct iovec *iov;
3947 	struct vnode *vp;
3948 	struct uio auio;
3949 	u_int iovlen;
3950 	u_int cnt;
3951 	int error;
3952 	int i;
3953 
3954 	error = copyin(uap->attrname, attrname, EXTATTR_MAXNAMELEN);
3955 	if (error)
3956 		return (error);
3957 
3958 	vp = NULL;
3959 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3960 	if (error == 0)
3961 		error = nlookup(&nd);
3962 	if (error == 0)
3963 		error = ncp_writechk(&nd.nl_nch);
3964 	if (error == 0)
3965 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
3966 	if (error) {
3967 		nlookup_done(&nd);
3968 		return (error);
3969 	}
3970 
3971 	needfree = NULL;
3972 	iovlen = uap->iovcnt * sizeof(struct iovec);
3973 	if (uap->iovcnt > UIO_SMALLIOV) {
3974 		if (uap->iovcnt > UIO_MAXIOV) {
3975 			error = EINVAL;
3976 			goto done;
3977 		}
3978 		MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK);
3979 		needfree = iov;
3980 	} else {
3981 		iov = aiov;
3982 	}
3983 	auio.uio_iov = iov;
3984 	auio.uio_iovcnt = uap->iovcnt;
3985 	auio.uio_rw = UIO_WRITE;
3986 	auio.uio_segflg = UIO_USERSPACE;
3987 	auio.uio_td = nd.nl_td;
3988 	auio.uio_offset = 0;
3989 	if ((error = copyin(uap->iovp, iov, iovlen)))
3990 		goto done;
3991 	auio.uio_resid = 0;
3992 	for (i = 0; i < uap->iovcnt; i++) {
3993 		if (iov->iov_len > INT_MAX - auio.uio_resid) {
3994 			error = EINVAL;
3995 			goto done;
3996 		}
3997 		auio.uio_resid += iov->iov_len;
3998 		iov++;
3999 	}
4000 	cnt = auio.uio_resid;
4001 	error = VOP_SETEXTATTR(vp, attrname, &auio, nd.nl_cred);
4002 	cnt -= auio.uio_resid;
4003 	uap->sysmsg_result = cnt;
4004 done:
4005 	vput(vp);
4006 	nlookup_done(&nd);
4007 	if (needfree)
4008 		FREE(needfree, M_IOV);
4009 	return (error);
4010 }
4011 
4012 /*
4013  * Syscall to get a named extended attribute on a file or directory.
4014  * Accepts attribute name, and a uio structure pointing to a buffer for the
4015  * data.  The uio is consumed in the style of readv().  The real work
4016  * happens in VOP_GETEXTATTR();
4017  */
4018 int
4019 sys_extattr_get_file(struct extattr_get_file_args *uap)
4020 {
4021 	char attrname[EXTATTR_MAXNAMELEN];
4022 	struct iovec aiov[UIO_SMALLIOV];
4023 	struct iovec *needfree;
4024 	struct nlookupdata nd;
4025 	struct iovec *iov;
4026 	struct vnode *vp;
4027 	struct uio auio;
4028 	u_int iovlen;
4029 	u_int cnt;
4030 	int error;
4031 	int i;
4032 
4033 	error = copyin(uap->attrname, attrname, EXTATTR_MAXNAMELEN);
4034 	if (error)
4035 		return (error);
4036 
4037 	vp = NULL;
4038 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4039 	if (error == 0)
4040 		error = nlookup(&nd);
4041 	if (error == 0)
4042 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
4043 	if (error) {
4044 		nlookup_done(&nd);
4045 		return (error);
4046 	}
4047 
4048 	iovlen = uap->iovcnt * sizeof (struct iovec);
4049 	needfree = NULL;
4050 	if (uap->iovcnt > UIO_SMALLIOV) {
4051 		if (uap->iovcnt > UIO_MAXIOV) {
4052 			error = EINVAL;
4053 			goto done;
4054 		}
4055 		MALLOC(iov, struct iovec *, iovlen, M_IOV, M_WAITOK);
4056 		needfree = iov;
4057 	} else {
4058 		iov = aiov;
4059 	}
4060 	auio.uio_iov = iov;
4061 	auio.uio_iovcnt = uap->iovcnt;
4062 	auio.uio_rw = UIO_READ;
4063 	auio.uio_segflg = UIO_USERSPACE;
4064 	auio.uio_td = nd.nl_td;
4065 	auio.uio_offset = 0;
4066 	if ((error = copyin(uap->iovp, iov, iovlen)))
4067 		goto done;
4068 	auio.uio_resid = 0;
4069 	for (i = 0; i < uap->iovcnt; i++) {
4070 		if (iov->iov_len > INT_MAX - auio.uio_resid) {
4071 			error = EINVAL;
4072 			goto done;
4073 		}
4074 		auio.uio_resid += iov->iov_len;
4075 		iov++;
4076 	}
4077 	cnt = auio.uio_resid;
4078 	error = VOP_GETEXTATTR(vp, attrname, &auio, nd.nl_cred);
4079 	cnt -= auio.uio_resid;
4080 	uap->sysmsg_result = cnt;
4081 done:
4082 	vput(vp);
4083 	nlookup_done(&nd);
4084 	if (needfree)
4085 		FREE(needfree, M_IOV);
4086 	return(error);
4087 }
4088 
4089 /*
4090  * Syscall to delete a named extended attribute from a file or directory.
4091  * Accepts attribute name.  The real work happens in VOP_SETEXTATTR().
4092  */
4093 int
4094 sys_extattr_delete_file(struct extattr_delete_file_args *uap)
4095 {
4096 	char attrname[EXTATTR_MAXNAMELEN];
4097 	struct nlookupdata nd;
4098 	struct vnode *vp;
4099 	int error;
4100 
4101 	error = copyin(uap->attrname, attrname, EXTATTR_MAXNAMELEN);
4102 	if (error)
4103 		return(error);
4104 
4105 	vp = NULL;
4106 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4107 	if (error == 0)
4108 		error = nlookup(&nd);
4109 	if (error == 0)
4110 		error = ncp_writechk(&nd.nl_nch);
4111 	if (error == 0)
4112 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
4113 	if (error) {
4114 		nlookup_done(&nd);
4115 		return (error);
4116 	}
4117 
4118 	error = VOP_SETEXTATTR(vp, attrname, NULL, nd.nl_cred);
4119 	vput(vp);
4120 	nlookup_done(&nd);
4121 	return(error);
4122 }
4123 
4124 /*
4125  * Determine if the mount is visible to the process.
4126  */
4127 static int
4128 chroot_visible_mnt(struct mount *mp, struct proc *p)
4129 {
4130 	struct nchandle nch;
4131 
4132 	/*
4133 	 * Traverse from the mount point upwards.  If we hit the process
4134 	 * root then the mount point is visible to the process.
4135 	 */
4136 	nch = mp->mnt_ncmountpt;
4137 	while (nch.ncp) {
4138 		if (nch.mount == p->p_fd->fd_nrdir.mount &&
4139 		    nch.ncp == p->p_fd->fd_nrdir.ncp) {
4140 			return(1);
4141 		}
4142 		if (nch.ncp == nch.mount->mnt_ncmountpt.ncp) {
4143 			nch = nch.mount->mnt_ncmounton;
4144 		} else {
4145 			nch.ncp = nch.ncp->nc_parent;
4146 		}
4147 	}
4148 
4149 	/*
4150 	 * If the mount point is not visible to the process, but the
4151 	 * process root is in a subdirectory of the mount, return
4152 	 * TRUE anyway.
4153 	 */
4154 	if (p->p_fd->fd_nrdir.mount == mp)
4155 		return(1);
4156 
4157 	return(0);
4158 }
4159 
4160