xref: /dragonfly/sys/kern/vfs_syscalls.c (revision 030b3383)
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. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)vfs_syscalls.c	8.13 (Berkeley) 4/15/94
35  * $FreeBSD: src/sys/kern/vfs_syscalls.c,v 1.151.2.18 2003/04/04 20:35:58 tegge Exp $
36  */
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/buf.h>
41 #include <sys/conf.h>
42 #include <sys/sysent.h>
43 #include <sys/malloc.h>
44 #include <sys/mount.h>
45 #include <sys/mountctl.h>
46 #include <sys/sysproto.h>
47 #include <sys/filedesc.h>
48 #include <sys/kernel.h>
49 #include <sys/fcntl.h>
50 #include <sys/file.h>
51 #include <sys/linker.h>
52 #include <sys/stat.h>
53 #include <sys/unistd.h>
54 #include <sys/vnode.h>
55 #include <sys/proc.h>
56 #include <sys/priv.h>
57 #include <sys/jail.h>
58 #include <sys/namei.h>
59 #include <sys/nlookup.h>
60 #include <sys/dirent.h>
61 #include <sys/extattr.h>
62 #include <sys/spinlock.h>
63 #include <sys/kern_syscall.h>
64 #include <sys/objcache.h>
65 #include <sys/sysctl.h>
66 
67 #include <sys/buf2.h>
68 #include <sys/file2.h>
69 #include <sys/spinlock2.h>
70 #include <sys/mplock2.h>
71 
72 #include <vm/vm.h>
73 #include <vm/vm_object.h>
74 #include <vm/vm_page.h>
75 
76 #include <machine/limits.h>
77 #include <machine/stdarg.h>
78 
79 static void mount_warning(struct mount *mp, const char *ctl, ...)
80 		__printflike(2, 3);
81 static int mount_path(struct proc *p, struct mount *mp, char **rb, char **fb);
82 static int checkvp_chdir (struct vnode *vn, struct thread *td);
83 static void checkdirs (struct nchandle *old_nch, struct nchandle *new_nch);
84 static int chroot_refuse_vdir_fds (struct filedesc *fdp);
85 static int chroot_visible_mnt(struct mount *mp, struct proc *p);
86 static int getutimes (struct timeval *, struct timespec *);
87 static int getutimens (const struct timespec *, struct timespec *, int *);
88 static int setfown (struct mount *, struct vnode *, uid_t, gid_t);
89 static int setfmode (struct vnode *, int);
90 static int setfflags (struct vnode *, int);
91 static int setutimes (struct vnode *, struct vattr *,
92 			const struct timespec *, int);
93 static int	usermount = 0;	/* if 1, non-root can mount fs. */
94 
95 SYSCTL_INT(_vfs, OID_AUTO, usermount, CTLFLAG_RW, &usermount, 0,
96     "Allow non-root users to mount filesystems");
97 
98 /*
99  * Virtual File System System Calls
100  */
101 
102 /*
103  * Mount a file system.
104  *
105  * mount_args(char *type, char *path, int flags, caddr_t data)
106  *
107  * MPALMOSTSAFE
108  */
109 int
110 sys_mount(struct mount_args *uap)
111 {
112 	struct thread *td = curthread;
113 	struct vnode *vp;
114 	struct nchandle nch;
115 	struct mount *mp, *nullmp;
116 	struct vfsconf *vfsp;
117 	int error, flag = 0, flag2 = 0;
118 	int hasmount;
119 	struct vattr va;
120 	struct nlookupdata nd;
121 	char fstypename[MFSNAMELEN];
122 	struct ucred *cred;
123 
124 	cred = td->td_ucred;
125 	if (jailed(cred)) {
126 		error = EPERM;
127 		goto done;
128 	}
129 	if (usermount == 0 && (error = priv_check(td, PRIV_ROOT)))
130 		goto done;
131 
132 	/*
133 	 * Do not allow NFS export by non-root users.
134 	 */
135 	if (uap->flags & MNT_EXPORTED) {
136 		error = priv_check(td, PRIV_ROOT);
137 		if (error)
138 			goto done;
139 	}
140 	/*
141 	 * Silently enforce MNT_NOSUID and MNT_NODEV for non-root users
142 	 */
143 	if (priv_check(td, PRIV_ROOT))
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 		goto done;
159 	}
160 
161 	/*
162 	 * If the target filesystem is resolved via a nullfs mount, then
163 	 * nd.nl_nch.mount will be pointing to the nullfs mount structure
164 	 * instead of the target file system. We need it in case we are
165 	 * doing an update.
166 	 */
167 	nullmp = nd.nl_nch.mount;
168 
169 	/*
170 	 * Extract the locked+refd ncp and cleanup the nd structure
171 	 */
172 	nch = nd.nl_nch;
173 	cache_zero(&nd.nl_nch);
174 	nlookup_done(&nd);
175 
176 	if ((nch.ncp->nc_flag & NCF_ISMOUNTPT) &&
177 	    (mp = cache_findmount(&nch)) != NULL) {
178 		cache_dropmount(mp);
179 		hasmount = 1;
180 	} else {
181 		hasmount = 0;
182 	}
183 
184 
185 	/*
186 	 * now we have the locked ref'd nch and unreferenced vnode.
187 	 */
188 	vp = nch.ncp->nc_vp;
189 	if ((error = vget(vp, LK_EXCLUSIVE)) != 0) {
190 		cache_put(&nch);
191 		goto done;
192 	}
193 	cache_unlock(&nch);
194 
195 	/*
196 	 * Extract the file system type. We need to know this early, to take
197 	 * appropriate actions if we are dealing with a nullfs.
198 	 */
199         if ((error = copyinstr(uap->type, fstypename, MFSNAMELEN, NULL)) != 0) {
200                 cache_drop(&nch);
201                 vput(vp);
202 		goto done;
203         }
204 
205 	/*
206 	 * Now we have an unlocked ref'd nch and a locked ref'd vp
207 	 */
208 	if (uap->flags & MNT_UPDATE) {
209 		if ((vp->v_flag & (VROOT|VPFSROOT)) == 0) {
210 			cache_drop(&nch);
211 			vput(vp);
212 			error = EINVAL;
213 			goto done;
214 		}
215 
216 		if (strncmp(fstypename, "null", 5) == 0) {
217 			KKASSERT(nullmp);
218 			mp = nullmp;
219 		} else {
220 			mp = vp->v_mount;
221 		}
222 
223 		flag = mp->mnt_flag;
224 		flag2 = mp->mnt_kern_flag;
225 		/*
226 		 * We only allow the filesystem to be reloaded if it
227 		 * is currently mounted read-only.
228 		 */
229 		if ((uap->flags & MNT_RELOAD) &&
230 		    ((mp->mnt_flag & MNT_RDONLY) == 0)) {
231 			cache_drop(&nch);
232 			vput(vp);
233 			error = EOPNOTSUPP;	/* Needs translation */
234 			goto done;
235 		}
236 		/*
237 		 * Only root, or the user that did the original mount is
238 		 * permitted to update it.
239 		 */
240 		if (mp->mnt_stat.f_owner != cred->cr_uid &&
241 		    (error = priv_check(td, PRIV_ROOT))) {
242 			cache_drop(&nch);
243 			vput(vp);
244 			goto done;
245 		}
246 		if (vfs_busy(mp, LK_NOWAIT)) {
247 			cache_drop(&nch);
248 			vput(vp);
249 			error = EBUSY;
250 			goto done;
251 		}
252 		if (hasmount) {
253 			cache_drop(&nch);
254 			vfs_unbusy(mp);
255 			vput(vp);
256 			error = EBUSY;
257 			goto done;
258 		}
259 		mp->mnt_flag |=
260 		    uap->flags & (MNT_RELOAD | MNT_FORCE | MNT_UPDATE);
261 		lwkt_gettoken(&mp->mnt_token);
262 		vn_unlock(vp);
263 		goto update;
264 	}
265 
266 	/*
267 	 * If the user is not root, ensure that they own the directory
268 	 * onto which we are attempting to mount.
269 	 */
270 	if ((error = VOP_GETATTR(vp, &va)) ||
271 	    (va.va_uid != cred->cr_uid &&
272 	     (error = priv_check(td, PRIV_ROOT)))) {
273 		cache_drop(&nch);
274 		vput(vp);
275 		goto done;
276 	}
277 	if ((error = vinvalbuf(vp, V_SAVE, 0, 0)) != 0) {
278 		cache_drop(&nch);
279 		vput(vp);
280 		goto done;
281 	}
282 	if (vp->v_type != VDIR) {
283 		cache_drop(&nch);
284 		vput(vp);
285 		error = ENOTDIR;
286 		goto done;
287 	}
288 	if (vp->v_mount->mnt_kern_flag & MNTK_NOSTKMNT) {
289 		cache_drop(&nch);
290 		vput(vp);
291 		error = EPERM;
292 		goto done;
293 	}
294 	vfsp = vfsconf_find_by_name(fstypename);
295 	if (vfsp == NULL) {
296 		linker_file_t lf;
297 
298 		/* Only load modules for root (very important!) */
299 		if ((error = priv_check(td, PRIV_ROOT)) != 0) {
300 			cache_drop(&nch);
301 			vput(vp);
302 			goto done;
303 		}
304 		error = linker_load_file(fstypename, &lf);
305 		if (error || lf == NULL) {
306 			cache_drop(&nch);
307 			vput(vp);
308 			if (lf == NULL)
309 				error = ENODEV;
310 			goto done;
311 		}
312 		lf->userrefs++;
313 		/* lookup again, see if the VFS was loaded */
314 		vfsp = vfsconf_find_by_name(fstypename);
315 		if (vfsp == NULL) {
316 			lf->userrefs--;
317 			linker_file_unload(lf);
318 			cache_drop(&nch);
319 			vput(vp);
320 			error = ENODEV;
321 			goto done;
322 		}
323 	}
324 	if (hasmount) {
325 		cache_drop(&nch);
326 		vput(vp);
327 		error = EBUSY;
328 		goto done;
329 	}
330 
331 	/*
332 	 * Allocate and initialize the filesystem.
333 	 */
334 	mp = kmalloc(sizeof(struct mount), M_MOUNT, M_ZERO|M_WAITOK);
335 	mount_init(mp);
336 	vfs_busy(mp, LK_NOWAIT);
337 	mp->mnt_op = vfsp->vfc_vfsops;
338 	mp->mnt_vfc = vfsp;
339 	vfsp->vfc_refcount++;
340 	mp->mnt_stat.f_type = vfsp->vfc_typenum;
341 	mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
342 	strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
343 	mp->mnt_stat.f_owner = cred->cr_uid;
344 	lwkt_gettoken(&mp->mnt_token);
345 	vn_unlock(vp);
346 update:
347 	/*
348 	 * (per-mount token acquired at this point)
349 	 *
350 	 * Set the mount level flags.
351 	 */
352 	if (uap->flags & MNT_RDONLY)
353 		mp->mnt_flag |= MNT_RDONLY;
354 	else if (mp->mnt_flag & MNT_RDONLY)
355 		mp->mnt_kern_flag |= MNTK_WANTRDWR;
356 	mp->mnt_flag &=~ (MNT_NOSUID | MNT_NOEXEC | MNT_NODEV |
357 	    MNT_SYNCHRONOUS | MNT_ASYNC | MNT_NOATIME |
358 	    MNT_NOSYMFOLLOW | MNT_IGNORE | MNT_TRIM |
359 	    MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
360 	mp->mnt_flag |= uap->flags & (MNT_NOSUID | MNT_NOEXEC |
361 	    MNT_NODEV | MNT_SYNCHRONOUS | MNT_ASYNC | MNT_FORCE |
362 	    MNT_NOSYMFOLLOW | MNT_IGNORE | MNT_TRIM |
363 	    MNT_NOATIME | MNT_NOCLUSTERR | MNT_NOCLUSTERW | MNT_SUIDDIR);
364 	/*
365 	 * Mount the filesystem.
366 	 * XXX The final recipients of VFS_MOUNT just overwrite the ndp they
367 	 * get.
368 	 */
369 	error = VFS_MOUNT(mp, uap->path, uap->data, cred);
370 	if (mp->mnt_flag & MNT_UPDATE) {
371 		if (mp->mnt_kern_flag & MNTK_WANTRDWR)
372 			mp->mnt_flag &= ~MNT_RDONLY;
373 		mp->mnt_flag &=~ (MNT_UPDATE | MNT_RELOAD | MNT_FORCE);
374 		mp->mnt_kern_flag &=~ MNTK_WANTRDWR;
375 		if (error) {
376 			mp->mnt_flag = flag;
377 			mp->mnt_kern_flag = flag2;
378 		}
379 		lwkt_reltoken(&mp->mnt_token);
380 		vfs_unbusy(mp);
381 		vrele(vp);
382 		cache_drop(&nch);
383 		goto done;
384 	}
385 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
386 
387 	/*
388 	 * Put the new filesystem on the mount list after root.  The mount
389 	 * point gets its own mnt_ncmountpt (unless the VFS already set one
390 	 * up) which represents the root of the mount.  The lookup code
391 	 * detects the mount point going forward and checks the root of
392 	 * the mount going backwards.
393 	 *
394 	 * It is not necessary to invalidate or purge the vnode underneath
395 	 * because elements under the mount will be given their own glue
396 	 * namecache record.
397 	 */
398 	if (!error) {
399 		if (mp->mnt_ncmountpt.ncp == NULL) {
400 			/*
401 			 * allocate, then unlock, but leave the ref intact
402 			 */
403 			cache_allocroot(&mp->mnt_ncmountpt, mp, NULL);
404 			cache_unlock(&mp->mnt_ncmountpt);
405 		}
406 		mp->mnt_ncmounton = nch;		/* inherits ref */
407 		nch.ncp->nc_flag |= NCF_ISMOUNTPT;
408 		cache_ismounting(mp);
409 
410 		mountlist_insert(mp, MNTINS_LAST);
411 		vn_unlock(vp);
412 		checkdirs(&mp->mnt_ncmounton, &mp->mnt_ncmountpt);
413 		error = vfs_allocate_syncvnode(mp);
414 		lwkt_reltoken(&mp->mnt_token);
415 		vfs_unbusy(mp);
416 		error = VFS_START(mp, 0);
417 		vrele(vp);
418 	} else {
419 		vn_syncer_thr_stop(mp);
420 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
421 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
422 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
423 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
424 		vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
425 		mp->mnt_vfc->vfc_refcount--;
426 		lwkt_reltoken(&mp->mnt_token);
427 		vfs_unbusy(mp);
428 		kfree(mp, M_MOUNT);
429 		cache_drop(&nch);
430 		vput(vp);
431 	}
432 done:
433 	return (error);
434 }
435 
436 /*
437  * Scan all active processes to see if any of them have a current
438  * or root directory onto which the new filesystem has just been
439  * mounted. If so, replace them with the new mount point.
440  *
441  * Both old_nch and new_nch are ref'd on call but not locked.
442  * new_nch must be temporarily locked so it can be associated with the
443  * vnode representing the root of the mount point.
444  */
445 struct checkdirs_info {
446 	struct nchandle old_nch;
447 	struct nchandle new_nch;
448 	struct vnode *old_vp;
449 	struct vnode *new_vp;
450 };
451 
452 static int checkdirs_callback(struct proc *p, void *data);
453 
454 static void
455 checkdirs(struct nchandle *old_nch, struct nchandle *new_nch)
456 {
457 	struct checkdirs_info info;
458 	struct vnode *olddp;
459 	struct vnode *newdp;
460 	struct mount *mp;
461 
462 	/*
463 	 * If the old mount point's vnode has a usecount of 1, it is not
464 	 * being held as a descriptor anywhere.
465 	 */
466 	olddp = old_nch->ncp->nc_vp;
467 	if (olddp == NULL || VREFCNT(olddp) == 1)
468 		return;
469 
470 	/*
471 	 * Force the root vnode of the new mount point to be resolved
472 	 * so we can update any matching processes.
473 	 */
474 	mp = new_nch->mount;
475 	if (VFS_ROOT(mp, &newdp))
476 		panic("mount: lost mount");
477 	vn_unlock(newdp);
478 	cache_lock(new_nch);
479 	vn_lock(newdp, LK_EXCLUSIVE | LK_RETRY);
480 	cache_setunresolved(new_nch);
481 	cache_setvp(new_nch, newdp);
482 	cache_unlock(new_nch);
483 
484 	/*
485 	 * Special handling of the root node
486 	 */
487 	if (rootvnode == olddp) {
488 		vref(newdp);
489 		vfs_cache_setroot(newdp, cache_hold(new_nch));
490 	}
491 
492 	/*
493 	 * Pass newdp separately so the callback does not have to access
494 	 * it via new_nch->ncp->nc_vp.
495 	 */
496 	info.old_nch = *old_nch;
497 	info.new_nch = *new_nch;
498 	info.new_vp = newdp;
499 	allproc_scan(checkdirs_callback, &info);
500 	vput(newdp);
501 }
502 
503 /*
504  * NOTE: callback is not MP safe because the scanned process's filedesc
505  * structure can be ripped out from under us, amoung other things.
506  */
507 static int
508 checkdirs_callback(struct proc *p, void *data)
509 {
510 	struct checkdirs_info *info = data;
511 	struct filedesc *fdp;
512 	struct nchandle ncdrop1;
513 	struct nchandle ncdrop2;
514 	struct vnode *vprele1;
515 	struct vnode *vprele2;
516 
517 	if ((fdp = p->p_fd) != NULL) {
518 		cache_zero(&ncdrop1);
519 		cache_zero(&ncdrop2);
520 		vprele1 = NULL;
521 		vprele2 = NULL;
522 
523 		/*
524 		 * MPUNSAFE - XXX fdp can be pulled out from under a
525 		 * foreign process.
526 		 *
527 		 * A shared filedesc is ok, we don't have to copy it
528 		 * because we are making this change globally.
529 		 */
530 		spin_lock(&fdp->fd_spin);
531 		if (fdp->fd_ncdir.mount == info->old_nch.mount &&
532 		    fdp->fd_ncdir.ncp == info->old_nch.ncp) {
533 			vprele1 = fdp->fd_cdir;
534 			vref(info->new_vp);
535 			fdp->fd_cdir = info->new_vp;
536 			ncdrop1 = fdp->fd_ncdir;
537 			cache_copy(&info->new_nch, &fdp->fd_ncdir);
538 		}
539 		if (fdp->fd_nrdir.mount == info->old_nch.mount &&
540 		    fdp->fd_nrdir.ncp == info->old_nch.ncp) {
541 			vprele2 = fdp->fd_rdir;
542 			vref(info->new_vp);
543 			fdp->fd_rdir = info->new_vp;
544 			ncdrop2 = fdp->fd_nrdir;
545 			cache_copy(&info->new_nch, &fdp->fd_nrdir);
546 		}
547 		spin_unlock(&fdp->fd_spin);
548 		if (ncdrop1.ncp)
549 			cache_drop(&ncdrop1);
550 		if (ncdrop2.ncp)
551 			cache_drop(&ncdrop2);
552 		if (vprele1)
553 			vrele(vprele1);
554 		if (vprele2)
555 			vrele(vprele2);
556 	}
557 	return(0);
558 }
559 
560 /*
561  * Unmount a file system.
562  *
563  * Note: unmount takes a path to the vnode mounted on as argument,
564  * not special file (as before).
565  *
566  * umount_args(char *path, int flags)
567  *
568  * MPALMOSTSAFE
569  */
570 int
571 sys_unmount(struct unmount_args *uap)
572 {
573 	struct thread *td = curthread;
574 	struct proc *p __debugvar = td->td_proc;
575 	struct mount *mp = NULL;
576 	struct nlookupdata nd;
577 	int error;
578 
579 	KKASSERT(p);
580 	get_mplock();
581 	if (td->td_ucred->cr_prison != NULL) {
582 		error = EPERM;
583 		goto done;
584 	}
585 	if (usermount == 0 && (error = priv_check(td, PRIV_ROOT)))
586 		goto done;
587 
588 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
589 	if (error == 0)
590 		error = nlookup(&nd);
591 	if (error)
592 		goto out;
593 
594 	mp = nd.nl_nch.mount;
595 
596 	/*
597 	 * Only root, or the user that did the original mount is
598 	 * permitted to unmount this filesystem.
599 	 */
600 	if ((mp->mnt_stat.f_owner != td->td_ucred->cr_uid) &&
601 	    (error = priv_check(td, PRIV_ROOT)))
602 		goto out;
603 
604 	/*
605 	 * Don't allow unmounting the root file system.
606 	 */
607 	if (mp->mnt_flag & MNT_ROOTFS) {
608 		error = EINVAL;
609 		goto out;
610 	}
611 
612 	/*
613 	 * Must be the root of the filesystem
614 	 */
615 	if (nd.nl_nch.ncp != mp->mnt_ncmountpt.ncp) {
616 		error = EINVAL;
617 		goto out;
618 	}
619 
620 out:
621 	nlookup_done(&nd);
622 	if (error == 0)
623 		error = dounmount(mp, uap->flags);
624 done:
625 	rel_mplock();
626 	return (error);
627 }
628 
629 /*
630  * Do the actual file system unmount.
631  */
632 static int
633 dounmount_interlock(struct mount *mp)
634 {
635 	if (mp->mnt_kern_flag & MNTK_UNMOUNT)
636 		return (EBUSY);
637 	mp->mnt_kern_flag |= MNTK_UNMOUNT;
638 	return(0);
639 }
640 
641 static int
642 unmount_allproc_cb(struct proc *p, void *arg)
643 {
644 	struct mount *mp;
645 
646 	if (p->p_textnch.ncp == NULL)
647 		return 0;
648 
649 	mp = (struct mount *)arg;
650 	if (p->p_textnch.mount == mp)
651 		cache_drop(&p->p_textnch);
652 
653 	return 0;
654 }
655 
656 int
657 dounmount(struct mount *mp, int flags)
658 {
659 	struct namecache *ncp;
660 	struct nchandle nch;
661 	struct vnode *vp;
662 	int error;
663 	int async_flag;
664 	int lflags;
665 	int freeok = 1;
666 	int retry;
667 
668 	lwkt_gettoken(&mp->mnt_token);
669 	/*
670 	 * Exclusive access for unmounting purposes
671 	 */
672 	if ((error = mountlist_interlock(dounmount_interlock, mp)) != 0)
673 		goto out;
674 
675 	/*
676 	 * Allow filesystems to detect that a forced unmount is in progress.
677 	 */
678 	if (flags & MNT_FORCE)
679 		mp->mnt_kern_flag |= MNTK_UNMOUNTF;
680 	lflags = LK_EXCLUSIVE | ((flags & MNT_FORCE) ? 0 : LK_TIMELOCK);
681 	error = lockmgr(&mp->mnt_lock, lflags);
682 	if (error) {
683 		mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
684 		if (mp->mnt_kern_flag & MNTK_MWAIT) {
685 			mp->mnt_kern_flag &= ~MNTK_MWAIT;
686 			wakeup(mp);
687 		}
688 		goto out;
689 	}
690 
691 	if (mp->mnt_flag & MNT_EXPUBLIC)
692 		vfs_setpublicfs(NULL, NULL, NULL);
693 
694 	vfs_msync(mp, MNT_WAIT);
695 	async_flag = mp->mnt_flag & MNT_ASYNC;
696 	mp->mnt_flag &=~ MNT_ASYNC;
697 
698 	/*
699 	 * If this filesystem isn't aliasing other filesystems,
700 	 * try to invalidate any remaining namecache entries and
701 	 * check the count afterwords.
702 	 */
703 	if ((mp->mnt_kern_flag & MNTK_NCALIASED) == 0) {
704 		cache_lock(&mp->mnt_ncmountpt);
705 		cache_inval(&mp->mnt_ncmountpt, CINV_DESTROY|CINV_CHILDREN);
706 		cache_unlock(&mp->mnt_ncmountpt);
707 
708 		if ((ncp = mp->mnt_ncmountpt.ncp) != NULL &&
709 		    (ncp->nc_refs != 1 || TAILQ_FIRST(&ncp->nc_list))) {
710 			allproc_scan(&unmount_allproc_cb, mp);
711 		}
712 
713 		if ((ncp = mp->mnt_ncmountpt.ncp) != NULL &&
714 		    (ncp->nc_refs != 1 || TAILQ_FIRST(&ncp->nc_list))) {
715 
716 			if ((flags & MNT_FORCE) == 0) {
717 				error = EBUSY;
718 				mount_warning(mp, "Cannot unmount: "
719 						  "%d namecache "
720 						  "references still "
721 						  "present",
722 						  ncp->nc_refs - 1);
723 			} else {
724 				mount_warning(mp, "Forced unmount: "
725 						  "%d namecache "
726 						  "references still "
727 						  "present",
728 						  ncp->nc_refs - 1);
729 				freeok = 0;
730 			}
731 		}
732 	}
733 
734 	/*
735 	 * Decomission our special mnt_syncer vnode.  This also stops
736 	 * the vnlru code.  If we are unable to unmount we recommission
737 	 * the vnode.
738 	 *
739 	 * Then sync the filesystem.
740 	 */
741 	if ((vp = mp->mnt_syncer) != NULL) {
742 		mp->mnt_syncer = NULL;
743 		atomic_set_int(&vp->v_refcnt, VREF_FINALIZE);
744 		vrele(vp);
745 	}
746 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
747 		VFS_SYNC(mp, MNT_WAIT);
748 
749 	/*
750 	 * nchandle records ref the mount structure.  Expect a count of 1
751 	 * (our mount->mnt_ncmountpt).
752 	 *
753 	 * Scans can get temporary refs on a mountpoint (thought really
754 	 * heavy duty stuff like cache_findmount() do not).
755 	 */
756 	for (retry = 0; retry < 10 && mp->mnt_refs != 1; ++retry) {
757 		cache_unmounting(mp);
758 		tsleep(&mp->mnt_refs, 0, "mntbsy", hz / 10 + 1);
759 	}
760 	if (mp->mnt_refs != 1) {
761 		if ((flags & MNT_FORCE) == 0) {
762 			mount_warning(mp, "Cannot unmount: "
763 					  "%d mount refs still present",
764 					  mp->mnt_refs);
765 			error = EBUSY;
766 		} else {
767 			mount_warning(mp, "Forced unmount: "
768 					  "%d mount refs still present",
769 					  mp->mnt_refs);
770 			freeok = 0;
771 		}
772 	}
773 
774 	/*
775 	 * So far so good, sync the filesystem once more and
776 	 * call the VFS unmount code if the sync succeeds.
777 	 */
778 	if (error == 0) {
779 		if (((mp->mnt_flag & MNT_RDONLY) ||
780 		     (error = VFS_SYNC(mp, MNT_WAIT)) == 0) ||
781 		    (flags & MNT_FORCE)) {
782 			error = VFS_UNMOUNT(mp, flags);
783 		}
784 	}
785 
786 	/*
787 	 * If an error occurred we can still recover, restoring the
788 	 * syncer vnode and misc flags.
789 	 */
790 	if (error) {
791 		if (mp->mnt_syncer == NULL)
792 			vfs_allocate_syncvnode(mp);
793 		mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
794 		mp->mnt_flag |= async_flag;
795 		lockmgr(&mp->mnt_lock, LK_RELEASE);
796 		if (mp->mnt_kern_flag & MNTK_MWAIT) {
797 			mp->mnt_kern_flag &= ~MNTK_MWAIT;
798 			wakeup(mp);
799 		}
800 		goto out;
801 	}
802 	/*
803 	 * Clean up any journals still associated with the mount after
804 	 * filesystem activity has ceased.
805 	 */
806 	journal_remove_all_journals(mp,
807 	    ((flags & MNT_FORCE) ? MC_JOURNAL_STOP_IMM : 0));
808 
809 	mountlist_remove(mp);
810 
811 	/*
812 	 * Remove any installed vnode ops here so the individual VFSs don't
813 	 * have to.
814 	 */
815 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_coherency_ops);
816 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_journal_ops);
817 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_norm_ops);
818 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_spec_ops);
819 	vfs_rm_vnodeops(mp, NULL, &mp->mnt_vn_fifo_ops);
820 
821 	if (mp->mnt_ncmountpt.ncp != NULL) {
822 		nch = mp->mnt_ncmountpt;
823 		cache_zero(&mp->mnt_ncmountpt);
824 		cache_clrmountpt(&nch);
825 		cache_drop(&nch);
826 	}
827 	if (mp->mnt_ncmounton.ncp != NULL) {
828 		cache_unmounting(mp);
829 		nch = mp->mnt_ncmounton;
830 		cache_zero(&mp->mnt_ncmounton);
831 		cache_clrmountpt(&nch);
832 		cache_drop(&nch);
833 	}
834 
835 	mp->mnt_vfc->vfc_refcount--;
836 	if (!TAILQ_EMPTY(&mp->mnt_nvnodelist))
837 		panic("unmount: dangling vnode");
838 	lockmgr(&mp->mnt_lock, LK_RELEASE);
839 	if (mp->mnt_kern_flag & MNTK_MWAIT) {
840 		mp->mnt_kern_flag &= ~MNTK_MWAIT;
841 		wakeup(mp);
842 	}
843 
844 	/*
845 	 * If we reach here and freeok != 0 we must free the mount.
846 	 * If refs > 1 cycle and wait, just in case someone tried
847 	 * to busy the mount after we decided to do the unmount.
848 	 */
849 	if (freeok) {
850 		while (mp->mnt_refs > 1) {
851 			cache_unmounting(mp);
852 			wakeup(mp);
853 			tsleep(&mp->mnt_refs, 0, "umntrwait", hz / 10 + 1);
854 		}
855 		lwkt_reltoken(&mp->mnt_token);
856 		kfree(mp, M_MOUNT);
857 		mp = NULL;
858 	}
859 	error = 0;
860 out:
861 	if (mp)
862 		lwkt_reltoken(&mp->mnt_token);
863 	return (error);
864 }
865 
866 static
867 void
868 mount_warning(struct mount *mp, const char *ctl, ...)
869 {
870 	char *ptr;
871 	char *buf;
872 	__va_list va;
873 
874 	__va_start(va, ctl);
875 	if (cache_fullpath(NULL, &mp->mnt_ncmounton, NULL,
876 			   &ptr, &buf, 0) == 0) {
877 		kprintf("unmount(%s): ", ptr);
878 		kvprintf(ctl, va);
879 		kprintf("\n");
880 		kfree(buf, M_TEMP);
881 	} else {
882 		kprintf("unmount(%p", mp);
883 		if (mp->mnt_ncmounton.ncp && mp->mnt_ncmounton.ncp->nc_name)
884 			kprintf(",%s", mp->mnt_ncmounton.ncp->nc_name);
885 		kprintf("): ");
886 		kvprintf(ctl, va);
887 		kprintf("\n");
888 	}
889 	__va_end(va);
890 }
891 
892 /*
893  * Shim cache_fullpath() to handle the case where a process is chrooted into
894  * a subdirectory of a mount.  In this case if the root mount matches the
895  * process root directory's mount we have to specify the process's root
896  * directory instead of the mount point, because the mount point might
897  * be above the root directory.
898  */
899 static
900 int
901 mount_path(struct proc *p, struct mount *mp, char **rb, char **fb)
902 {
903 	struct nchandle *nch;
904 
905 	if (p && p->p_fd->fd_nrdir.mount == mp)
906 		nch = &p->p_fd->fd_nrdir;
907 	else
908 		nch = &mp->mnt_ncmountpt;
909 	return(cache_fullpath(p, nch, NULL, rb, fb, 0));
910 }
911 
912 /*
913  * Sync each mounted filesystem.
914  */
915 
916 #ifdef DEBUG
917 static int syncprt = 0;
918 SYSCTL_INT(_debug, OID_AUTO, syncprt, CTLFLAG_RW, &syncprt, 0, "");
919 #endif /* DEBUG */
920 
921 static int sync_callback(struct mount *mp, void *data);
922 
923 int
924 sys_sync(struct sync_args *uap)
925 {
926 	mountlist_scan(sync_callback, NULL, MNTSCAN_FORWARD);
927 	return (0);
928 }
929 
930 static
931 int
932 sync_callback(struct mount *mp, void *data __unused)
933 {
934 	int asyncflag;
935 
936 	if ((mp->mnt_flag & MNT_RDONLY) == 0) {
937 		asyncflag = mp->mnt_flag & MNT_ASYNC;
938 		mp->mnt_flag &= ~MNT_ASYNC;
939 		vfs_msync(mp, MNT_NOWAIT);
940 		VFS_SYNC(mp, MNT_NOWAIT);
941 		mp->mnt_flag |= asyncflag;
942 	}
943 	return(0);
944 }
945 
946 /* XXX PRISON: could be per prison flag */
947 static int prison_quotas;
948 #if 0
949 SYSCTL_INT(_kern_prison, OID_AUTO, quotas, CTLFLAG_RW, &prison_quotas, 0, "");
950 #endif
951 
952 /*
953  *  quotactl_args(char *path, int fcmd, int uid, caddr_t arg)
954  *
955  * Change filesystem quotas.
956  *
957  * MPALMOSTSAFE
958  */
959 int
960 sys_quotactl(struct quotactl_args *uap)
961 {
962 	struct nlookupdata nd;
963 	struct thread *td;
964 	struct mount *mp;
965 	int error;
966 
967 	get_mplock();
968 	td = curthread;
969 	if (td->td_ucred->cr_prison && !prison_quotas) {
970 		error = EPERM;
971 		goto done;
972 	}
973 
974 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
975 	if (error == 0)
976 		error = nlookup(&nd);
977 	if (error == 0) {
978 		mp = nd.nl_nch.mount;
979 		error = VFS_QUOTACTL(mp, uap->cmd, uap->uid,
980 				    uap->arg, nd.nl_cred);
981 	}
982 	nlookup_done(&nd);
983 done:
984 	rel_mplock();
985 	return (error);
986 }
987 
988 /*
989  * mountctl(char *path, int op, int fd, const void *ctl, int ctllen,
990  *		void *buf, int buflen)
991  *
992  * This function operates on a mount point and executes the specified
993  * operation using the specified control data, and possibly returns data.
994  *
995  * The actual number of bytes stored in the result buffer is returned, 0
996  * if none, otherwise an error is returned.
997  *
998  * MPALMOSTSAFE
999  */
1000 int
1001 sys_mountctl(struct mountctl_args *uap)
1002 {
1003 	struct thread *td = curthread;
1004 	struct proc *p = td->td_proc;
1005 	struct file *fp;
1006 	void *ctl = NULL;
1007 	void *buf = NULL;
1008 	char *path = NULL;
1009 	int error;
1010 
1011 	/*
1012 	 * Sanity and permissions checks.  We must be root.
1013 	 */
1014 	KKASSERT(p);
1015 	if (td->td_ucred->cr_prison != NULL)
1016 		return (EPERM);
1017 	if ((uap->op != MOUNTCTL_MOUNTFLAGS) &&
1018 	    (error = priv_check(td, PRIV_ROOT)) != 0)
1019 		return (error);
1020 
1021 	/*
1022 	 * Argument length checks
1023 	 */
1024 	if (uap->ctllen < 0 || uap->ctllen > 1024)
1025 		return (EINVAL);
1026 	if (uap->buflen < 0 || uap->buflen > 16 * 1024)
1027 		return (EINVAL);
1028 	if (uap->path == NULL)
1029 		return (EINVAL);
1030 
1031 	/*
1032 	 * Allocate the necessary buffers and copyin data
1033 	 */
1034 	path = objcache_get(namei_oc, M_WAITOK);
1035 	error = copyinstr(uap->path, path, MAXPATHLEN, NULL);
1036 	if (error)
1037 		goto done;
1038 
1039 	if (uap->ctllen) {
1040 		ctl = kmalloc(uap->ctllen + 1, M_TEMP, M_WAITOK|M_ZERO);
1041 		error = copyin(uap->ctl, ctl, uap->ctllen);
1042 		if (error)
1043 			goto done;
1044 	}
1045 	if (uap->buflen)
1046 		buf = kmalloc(uap->buflen + 1, M_TEMP, M_WAITOK|M_ZERO);
1047 
1048 	/*
1049 	 * Validate the descriptor
1050 	 */
1051 	if (uap->fd >= 0) {
1052 		fp = holdfp(p->p_fd, uap->fd, -1);
1053 		if (fp == NULL) {
1054 			error = EBADF;
1055 			goto done;
1056 		}
1057 	} else {
1058 		fp = NULL;
1059 	}
1060 
1061 	/*
1062 	 * Execute the internal kernel function and clean up.
1063 	 */
1064 	get_mplock();
1065 	error = kern_mountctl(path, uap->op, fp, ctl, uap->ctllen, buf, uap->buflen, &uap->sysmsg_result);
1066 	rel_mplock();
1067 	if (fp)
1068 		fdrop(fp);
1069 	if (error == 0 && uap->sysmsg_result > 0)
1070 		error = copyout(buf, uap->buf, uap->sysmsg_result);
1071 done:
1072 	if (path)
1073 		objcache_put(namei_oc, path);
1074 	if (ctl)
1075 		kfree(ctl, M_TEMP);
1076 	if (buf)
1077 		kfree(buf, M_TEMP);
1078 	return (error);
1079 }
1080 
1081 /*
1082  * Execute a mount control operation by resolving the path to a mount point
1083  * and calling vop_mountctl().
1084  *
1085  * Use the mount point from the nch instead of the vnode so nullfs mounts
1086  * can properly spike the VOP.
1087  */
1088 int
1089 kern_mountctl(const char *path, int op, struct file *fp,
1090 		const void *ctl, int ctllen,
1091 		void *buf, int buflen, int *res)
1092 {
1093 	struct vnode *vp;
1094 	struct mount *mp;
1095 	struct nlookupdata nd;
1096 	int error;
1097 
1098 	*res = 0;
1099 	vp = NULL;
1100 	error = nlookup_init(&nd, path, UIO_SYSSPACE, NLC_FOLLOW);
1101 	if (error == 0)
1102 		error = nlookup(&nd);
1103 	if (error == 0)
1104 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
1105 	mp = nd.nl_nch.mount;
1106 	nlookup_done(&nd);
1107 	if (error)
1108 		return (error);
1109 	vn_unlock(vp);
1110 
1111 	/*
1112 	 * Must be the root of the filesystem
1113 	 */
1114 	if ((vp->v_flag & (VROOT|VPFSROOT)) == 0) {
1115 		vrele(vp);
1116 		return (EINVAL);
1117 	}
1118 	error = vop_mountctl(mp->mnt_vn_use_ops, vp, op, fp, ctl, ctllen,
1119 			     buf, buflen, res);
1120 	vrele(vp);
1121 	return (error);
1122 }
1123 
1124 int
1125 kern_statfs(struct nlookupdata *nd, struct statfs *buf)
1126 {
1127 	struct thread *td = curthread;
1128 	struct proc *p = td->td_proc;
1129 	struct mount *mp;
1130 	struct statfs *sp;
1131 	char *fullpath, *freepath;
1132 	int error;
1133 
1134 	if ((error = nlookup(nd)) != 0)
1135 		return (error);
1136 	mp = nd->nl_nch.mount;
1137 	sp = &mp->mnt_stat;
1138 	if ((error = VFS_STATFS(mp, sp, nd->nl_cred)) != 0)
1139 		return (error);
1140 
1141 	error = mount_path(p, mp, &fullpath, &freepath);
1142 	if (error)
1143 		return(error);
1144 	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1145 	strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1146 	kfree(freepath, M_TEMP);
1147 
1148 	sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1149 	bcopy(sp, buf, sizeof(*buf));
1150 	/* Only root should have access to the fsid's. */
1151 	if (priv_check(td, PRIV_ROOT))
1152 		buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
1153 	return (0);
1154 }
1155 
1156 /*
1157  * statfs_args(char *path, struct statfs *buf)
1158  *
1159  * Get filesystem statistics.
1160  */
1161 int
1162 sys_statfs(struct statfs_args *uap)
1163 {
1164 	struct nlookupdata nd;
1165 	struct statfs buf;
1166 	int error;
1167 
1168 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1169 	if (error == 0)
1170 		error = kern_statfs(&nd, &buf);
1171 	nlookup_done(&nd);
1172 	if (error == 0)
1173 		error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1174 	return (error);
1175 }
1176 
1177 int
1178 kern_fstatfs(int fd, struct statfs *buf)
1179 {
1180 	struct thread *td = curthread;
1181 	struct proc *p = td->td_proc;
1182 	struct file *fp;
1183 	struct mount *mp;
1184 	struct statfs *sp;
1185 	char *fullpath, *freepath;
1186 	int error;
1187 
1188 	KKASSERT(p);
1189 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
1190 		return (error);
1191 
1192 	/*
1193 	 * Try to use mount info from any overlays rather than the
1194 	 * mount info for the underlying vnode, otherwise we will
1195 	 * fail when operating on null-mounted paths inside a chroot.
1196 	 */
1197 	if ((mp = fp->f_nchandle.mount) == NULL)
1198 		mp = ((struct vnode *)fp->f_data)->v_mount;
1199 	if (mp == NULL) {
1200 		error = EBADF;
1201 		goto done;
1202 	}
1203 	if (fp->f_cred == NULL) {
1204 		error = EINVAL;
1205 		goto done;
1206 	}
1207 	sp = &mp->mnt_stat;
1208 	if ((error = VFS_STATFS(mp, sp, fp->f_cred)) != 0)
1209 		goto done;
1210 
1211 	if ((error = mount_path(p, mp, &fullpath, &freepath)) != 0)
1212 		goto done;
1213 	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1214 	strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1215 	kfree(freepath, M_TEMP);
1216 
1217 	sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1218 	bcopy(sp, buf, sizeof(*buf));
1219 
1220 	/* Only root should have access to the fsid's. */
1221 	if (priv_check(td, PRIV_ROOT))
1222 		buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
1223 	error = 0;
1224 done:
1225 	fdrop(fp);
1226 	return (error);
1227 }
1228 
1229 /*
1230  * fstatfs_args(int fd, struct statfs *buf)
1231  *
1232  * Get filesystem statistics.
1233  */
1234 int
1235 sys_fstatfs(struct fstatfs_args *uap)
1236 {
1237 	struct statfs buf;
1238 	int error;
1239 
1240 	error = kern_fstatfs(uap->fd, &buf);
1241 
1242 	if (error == 0)
1243 		error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1244 	return (error);
1245 }
1246 
1247 int
1248 kern_statvfs(struct nlookupdata *nd, struct statvfs *buf)
1249 {
1250 	struct mount *mp;
1251 	struct statvfs *sp;
1252 	int error;
1253 
1254 	if ((error = nlookup(nd)) != 0)
1255 		return (error);
1256 	mp = nd->nl_nch.mount;
1257 	sp = &mp->mnt_vstat;
1258 	if ((error = VFS_STATVFS(mp, sp, nd->nl_cred)) != 0)
1259 		return (error);
1260 
1261 	sp->f_flag = 0;
1262 	if (mp->mnt_flag & MNT_RDONLY)
1263 		sp->f_flag |= ST_RDONLY;
1264 	if (mp->mnt_flag & MNT_NOSUID)
1265 		sp->f_flag |= ST_NOSUID;
1266 	bcopy(sp, buf, sizeof(*buf));
1267 	return (0);
1268 }
1269 
1270 /*
1271  * statfs_args(char *path, struct statfs *buf)
1272  *
1273  * Get filesystem statistics.
1274  */
1275 int
1276 sys_statvfs(struct statvfs_args *uap)
1277 {
1278 	struct nlookupdata nd;
1279 	struct statvfs buf;
1280 	int error;
1281 
1282 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1283 	if (error == 0)
1284 		error = kern_statvfs(&nd, &buf);
1285 	nlookup_done(&nd);
1286 	if (error == 0)
1287 		error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1288 	return (error);
1289 }
1290 
1291 int
1292 kern_fstatvfs(int fd, struct statvfs *buf)
1293 {
1294 	struct thread *td = curthread;
1295 	struct proc *p = td->td_proc;
1296 	struct file *fp;
1297 	struct mount *mp;
1298 	struct statvfs *sp;
1299 	int error;
1300 
1301 	KKASSERT(p);
1302 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
1303 		return (error);
1304 	if ((mp = fp->f_nchandle.mount) == NULL)
1305 		mp = ((struct vnode *)fp->f_data)->v_mount;
1306 	if (mp == NULL) {
1307 		error = EBADF;
1308 		goto done;
1309 	}
1310 	if (fp->f_cred == NULL) {
1311 		error = EINVAL;
1312 		goto done;
1313 	}
1314 	sp = &mp->mnt_vstat;
1315 	if ((error = VFS_STATVFS(mp, sp, fp->f_cred)) != 0)
1316 		goto done;
1317 
1318 	sp->f_flag = 0;
1319 	if (mp->mnt_flag & MNT_RDONLY)
1320 		sp->f_flag |= ST_RDONLY;
1321 	if (mp->mnt_flag & MNT_NOSUID)
1322 		sp->f_flag |= ST_NOSUID;
1323 
1324 	bcopy(sp, buf, sizeof(*buf));
1325 	error = 0;
1326 done:
1327 	fdrop(fp);
1328 	return (error);
1329 }
1330 
1331 /*
1332  * fstatfs_args(int fd, struct statfs *buf)
1333  *
1334  * Get filesystem statistics.
1335  */
1336 int
1337 sys_fstatvfs(struct fstatvfs_args *uap)
1338 {
1339 	struct statvfs buf;
1340 	int error;
1341 
1342 	error = kern_fstatvfs(uap->fd, &buf);
1343 
1344 	if (error == 0)
1345 		error = copyout(&buf, uap->buf, sizeof(*uap->buf));
1346 	return (error);
1347 }
1348 
1349 /*
1350  * getfsstat_args(struct statfs *buf, long bufsize, int flags)
1351  *
1352  * Get statistics on all filesystems.
1353  */
1354 
1355 struct getfsstat_info {
1356 	struct statfs *sfsp;
1357 	long count;
1358 	long maxcount;
1359 	int error;
1360 	int flags;
1361 	struct thread *td;
1362 };
1363 
1364 static int getfsstat_callback(struct mount *, void *);
1365 
1366 int
1367 sys_getfsstat(struct getfsstat_args *uap)
1368 {
1369 	struct thread *td = curthread;
1370 	struct getfsstat_info info;
1371 
1372 	bzero(&info, sizeof(info));
1373 
1374 	info.maxcount = uap->bufsize / sizeof(struct statfs);
1375 	info.sfsp = uap->buf;
1376 	info.count = 0;
1377 	info.flags = uap->flags;
1378 	info.td = td;
1379 
1380 	mountlist_scan(getfsstat_callback, &info, MNTSCAN_FORWARD);
1381 	if (info.sfsp && info.count > info.maxcount)
1382 		uap->sysmsg_result = info.maxcount;
1383 	else
1384 		uap->sysmsg_result = info.count;
1385 	return (info.error);
1386 }
1387 
1388 static int
1389 getfsstat_callback(struct mount *mp, void *data)
1390 {
1391 	struct getfsstat_info *info = data;
1392 	struct statfs *sp;
1393 	char *freepath;
1394 	char *fullpath;
1395 	int error;
1396 
1397 	if (info->sfsp && info->count < info->maxcount) {
1398 		if (info->td->td_proc &&
1399 		    !chroot_visible_mnt(mp, info->td->td_proc)) {
1400 			return(0);
1401 		}
1402 		sp = &mp->mnt_stat;
1403 
1404 		/*
1405 		 * If MNT_NOWAIT or MNT_LAZY is specified, do not
1406 		 * refresh the fsstat cache. MNT_NOWAIT or MNT_LAZY
1407 		 * overrides MNT_WAIT.
1408 		 */
1409 		if (((info->flags & (MNT_LAZY|MNT_NOWAIT)) == 0 ||
1410 		    (info->flags & MNT_WAIT)) &&
1411 		    (error = VFS_STATFS(mp, sp, info->td->td_ucred))) {
1412 			return(0);
1413 		}
1414 		sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1415 
1416 		error = mount_path(info->td->td_proc, mp, &fullpath, &freepath);
1417 		if (error) {
1418 			info->error = error;
1419 			return(-1);
1420 		}
1421 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1422 		strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1423 		kfree(freepath, M_TEMP);
1424 
1425 		error = copyout(sp, info->sfsp, sizeof(*sp));
1426 		if (error) {
1427 			info->error = error;
1428 			return (-1);
1429 		}
1430 		++info->sfsp;
1431 	}
1432 	info->count++;
1433 	return(0);
1434 }
1435 
1436 /*
1437  * getvfsstat_args(struct statfs *buf, struct statvfs *vbuf,
1438 		   long bufsize, int flags)
1439  *
1440  * Get statistics on all filesystems.
1441  */
1442 
1443 struct getvfsstat_info {
1444 	struct statfs *sfsp;
1445 	struct statvfs *vsfsp;
1446 	long count;
1447 	long maxcount;
1448 	int error;
1449 	int flags;
1450 	struct thread *td;
1451 };
1452 
1453 static int getvfsstat_callback(struct mount *, void *);
1454 
1455 int
1456 sys_getvfsstat(struct getvfsstat_args *uap)
1457 {
1458 	struct thread *td = curthread;
1459 	struct getvfsstat_info info;
1460 
1461 	bzero(&info, sizeof(info));
1462 
1463 	info.maxcount = uap->vbufsize / sizeof(struct statvfs);
1464 	info.sfsp = uap->buf;
1465 	info.vsfsp = uap->vbuf;
1466 	info.count = 0;
1467 	info.flags = uap->flags;
1468 	info.td = td;
1469 
1470 	mountlist_scan(getvfsstat_callback, &info, MNTSCAN_FORWARD);
1471 	if (info.vsfsp && info.count > info.maxcount)
1472 		uap->sysmsg_result = info.maxcount;
1473 	else
1474 		uap->sysmsg_result = info.count;
1475 	return (info.error);
1476 }
1477 
1478 static int
1479 getvfsstat_callback(struct mount *mp, void *data)
1480 {
1481 	struct getvfsstat_info *info = data;
1482 	struct statfs *sp;
1483 	struct statvfs *vsp;
1484 	char *freepath;
1485 	char *fullpath;
1486 	int error;
1487 
1488 	if (info->vsfsp && info->count < info->maxcount) {
1489 		if (info->td->td_proc &&
1490 		    !chroot_visible_mnt(mp, info->td->td_proc)) {
1491 			return(0);
1492 		}
1493 		sp = &mp->mnt_stat;
1494 		vsp = &mp->mnt_vstat;
1495 
1496 		/*
1497 		 * If MNT_NOWAIT or MNT_LAZY is specified, do not
1498 		 * refresh the fsstat cache. MNT_NOWAIT or MNT_LAZY
1499 		 * overrides MNT_WAIT.
1500 		 */
1501 		if (((info->flags & (MNT_LAZY|MNT_NOWAIT)) == 0 ||
1502 		    (info->flags & MNT_WAIT)) &&
1503 		    (error = VFS_STATFS(mp, sp, info->td->td_ucred))) {
1504 			return(0);
1505 		}
1506 		sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
1507 
1508 		if (((info->flags & (MNT_LAZY|MNT_NOWAIT)) == 0 ||
1509 		    (info->flags & MNT_WAIT)) &&
1510 		    (error = VFS_STATVFS(mp, vsp, info->td->td_ucred))) {
1511 			return(0);
1512 		}
1513 		vsp->f_flag = 0;
1514 		if (mp->mnt_flag & MNT_RDONLY)
1515 			vsp->f_flag |= ST_RDONLY;
1516 		if (mp->mnt_flag & MNT_NOSUID)
1517 			vsp->f_flag |= ST_NOSUID;
1518 
1519 		error = mount_path(info->td->td_proc, mp, &fullpath, &freepath);
1520 		if (error) {
1521 			info->error = error;
1522 			return(-1);
1523 		}
1524 		bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
1525 		strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
1526 		kfree(freepath, M_TEMP);
1527 
1528 		error = copyout(sp, info->sfsp, sizeof(*sp));
1529 		if (error == 0)
1530 			error = copyout(vsp, info->vsfsp, sizeof(*vsp));
1531 		if (error) {
1532 			info->error = error;
1533 			return (-1);
1534 		}
1535 		++info->sfsp;
1536 		++info->vsfsp;
1537 	}
1538 	info->count++;
1539 	return(0);
1540 }
1541 
1542 
1543 /*
1544  * fchdir_args(int fd)
1545  *
1546  * Change current working directory to a given file descriptor.
1547  */
1548 int
1549 sys_fchdir(struct fchdir_args *uap)
1550 {
1551 	struct thread *td = curthread;
1552 	struct proc *p = td->td_proc;
1553 	struct filedesc *fdp = p->p_fd;
1554 	struct vnode *vp, *ovp;
1555 	struct mount *mp;
1556 	struct file *fp;
1557 	struct nchandle nch, onch, tnch;
1558 	int error;
1559 
1560 	if ((error = holdvnode(fdp, uap->fd, &fp)) != 0)
1561 		return (error);
1562 	lwkt_gettoken(&p->p_token);
1563 	vp = (struct vnode *)fp->f_data;
1564 	vref(vp);
1565 	vn_lock(vp, LK_SHARED | LK_RETRY);
1566 	if (fp->f_nchandle.ncp == NULL)
1567 		error = ENOTDIR;
1568 	else
1569 		error = checkvp_chdir(vp, td);
1570 	if (error) {
1571 		vput(vp);
1572 		goto done;
1573 	}
1574 	cache_copy(&fp->f_nchandle, &nch);
1575 
1576 	/*
1577 	 * If the ncp has become a mount point, traverse through
1578 	 * the mount point.
1579 	 */
1580 
1581 	while (!error && (nch.ncp->nc_flag & NCF_ISMOUNTPT) &&
1582 	       (mp = cache_findmount(&nch)) != NULL
1583 	) {
1584 		error = nlookup_mp(mp, &tnch);
1585 		if (error == 0) {
1586 			cache_unlock(&tnch);	/* leave ref intact */
1587 			vput(vp);
1588 			vp = tnch.ncp->nc_vp;
1589 			error = vget(vp, LK_SHARED);
1590 			KKASSERT(error == 0);
1591 			cache_drop(&nch);
1592 			nch = tnch;
1593 		}
1594 		cache_dropmount(mp);
1595 	}
1596 	if (error == 0) {
1597 		ovp = fdp->fd_cdir;
1598 		onch = fdp->fd_ncdir;
1599 		vn_unlock(vp);		/* leave ref intact */
1600 		fdp->fd_cdir = vp;
1601 		fdp->fd_ncdir = nch;
1602 		cache_drop(&onch);
1603 		vrele(ovp);
1604 	} else {
1605 		cache_drop(&nch);
1606 		vput(vp);
1607 	}
1608 	fdrop(fp);
1609 done:
1610 	lwkt_reltoken(&p->p_token);
1611 	return (error);
1612 }
1613 
1614 int
1615 kern_chdir(struct nlookupdata *nd)
1616 {
1617 	struct thread *td = curthread;
1618 	struct proc *p = td->td_proc;
1619 	struct filedesc *fdp = p->p_fd;
1620 	struct vnode *vp, *ovp;
1621 	struct nchandle onch;
1622 	int error;
1623 
1624 	nd->nl_flags |= NLC_SHAREDLOCK;
1625 	if ((error = nlookup(nd)) != 0)
1626 		return (error);
1627 	if ((vp = nd->nl_nch.ncp->nc_vp) == NULL)
1628 		return (ENOENT);
1629 	if ((error = vget(vp, LK_SHARED)) != 0)
1630 		return (error);
1631 
1632 	lwkt_gettoken(&p->p_token);
1633 	error = checkvp_chdir(vp, td);
1634 	vn_unlock(vp);
1635 	if (error == 0) {
1636 		ovp = fdp->fd_cdir;
1637 		onch = fdp->fd_ncdir;
1638 		cache_unlock(&nd->nl_nch);	/* leave reference intact */
1639 		fdp->fd_ncdir = nd->nl_nch;
1640 		fdp->fd_cdir = vp;
1641 		cache_drop(&onch);
1642 		vrele(ovp);
1643 		cache_zero(&nd->nl_nch);
1644 	} else {
1645 		vrele(vp);
1646 	}
1647 	lwkt_reltoken(&p->p_token);
1648 	return (error);
1649 }
1650 
1651 /*
1652  * chdir_args(char *path)
1653  *
1654  * Change current working directory (``.'').
1655  */
1656 int
1657 sys_chdir(struct chdir_args *uap)
1658 {
1659 	struct nlookupdata nd;
1660 	int error;
1661 
1662 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1663 	if (error == 0)
1664 		error = kern_chdir(&nd);
1665 	nlookup_done(&nd);
1666 	return (error);
1667 }
1668 
1669 /*
1670  * Helper function for raised chroot(2) security function:  Refuse if
1671  * any filedescriptors are open directories.
1672  */
1673 static int
1674 chroot_refuse_vdir_fds(struct filedesc *fdp)
1675 {
1676 	struct vnode *vp;
1677 	struct file *fp;
1678 	int error;
1679 	int fd;
1680 
1681 	for (fd = 0; fd < fdp->fd_nfiles ; fd++) {
1682 		if ((error = holdvnode(fdp, fd, &fp)) != 0)
1683 			continue;
1684 		vp = (struct vnode *)fp->f_data;
1685 		if (vp->v_type != VDIR) {
1686 			fdrop(fp);
1687 			continue;
1688 		}
1689 		fdrop(fp);
1690 		return(EPERM);
1691 	}
1692 	return (0);
1693 }
1694 
1695 /*
1696  * This sysctl determines if we will allow a process to chroot(2) if it
1697  * has a directory open:
1698  *	0: disallowed for all processes.
1699  *	1: allowed for processes that were not already chroot(2)'ed.
1700  *	2: allowed for all processes.
1701  */
1702 
1703 static int chroot_allow_open_directories = 1;
1704 
1705 SYSCTL_INT(_kern, OID_AUTO, chroot_allow_open_directories, CTLFLAG_RW,
1706      &chroot_allow_open_directories, 0, "");
1707 
1708 /*
1709  * chroot to the specified namecache entry.  We obtain the vp from the
1710  * namecache data.  The passed ncp must be locked and referenced and will
1711  * remain locked and referenced on return.
1712  */
1713 int
1714 kern_chroot(struct nchandle *nch)
1715 {
1716 	struct thread *td = curthread;
1717 	struct proc *p = td->td_proc;
1718 	struct filedesc *fdp = p->p_fd;
1719 	struct vnode *vp;
1720 	int error;
1721 
1722 	/*
1723 	 * Only privileged user can chroot
1724 	 */
1725 	error = priv_check_cred(td->td_ucred, PRIV_VFS_CHROOT, 0);
1726 	if (error)
1727 		return (error);
1728 
1729 	/*
1730 	 * Disallow open directory descriptors (fchdir() breakouts).
1731 	 */
1732 	if (chroot_allow_open_directories == 0 ||
1733 	   (chroot_allow_open_directories == 1 && fdp->fd_rdir != rootvnode)) {
1734 		if ((error = chroot_refuse_vdir_fds(fdp)) != 0)
1735 			return (error);
1736 	}
1737 	if ((vp = nch->ncp->nc_vp) == NULL)
1738 		return (ENOENT);
1739 
1740 	if ((error = vget(vp, LK_SHARED)) != 0)
1741 		return (error);
1742 
1743 	/*
1744 	 * Check the validity of vp as a directory to change to and
1745 	 * associate it with rdir/jdir.
1746 	 */
1747 	error = checkvp_chdir(vp, td);
1748 	vn_unlock(vp);			/* leave reference intact */
1749 	if (error == 0) {
1750 		vrele(fdp->fd_rdir);
1751 		fdp->fd_rdir = vp;	/* reference inherited by fd_rdir */
1752 		cache_drop(&fdp->fd_nrdir);
1753 		cache_copy(nch, &fdp->fd_nrdir);
1754 		if (fdp->fd_jdir == NULL) {
1755 			fdp->fd_jdir = vp;
1756 			vref(fdp->fd_jdir);
1757 			cache_copy(nch, &fdp->fd_njdir);
1758 		}
1759 	} else {
1760 		vrele(vp);
1761 	}
1762 	return (error);
1763 }
1764 
1765 /*
1766  * chroot_args(char *path)
1767  *
1768  * Change notion of root (``/'') directory.
1769  */
1770 int
1771 sys_chroot(struct chroot_args *uap)
1772 {
1773 	struct thread *td __debugvar = curthread;
1774 	struct nlookupdata nd;
1775 	int error;
1776 
1777 	KKASSERT(td->td_proc);
1778 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1779 	if (error == 0) {
1780 		nd.nl_flags |= NLC_EXEC;
1781 		error = nlookup(&nd);
1782 		if (error == 0)
1783 			error = kern_chroot(&nd.nl_nch);
1784 	}
1785 	nlookup_done(&nd);
1786 	return(error);
1787 }
1788 
1789 int
1790 sys_chroot_kernel(struct chroot_kernel_args *uap)
1791 {
1792 	struct thread *td = curthread;
1793 	struct nlookupdata nd;
1794 	struct nchandle *nch;
1795 	struct vnode *vp;
1796 	int error;
1797 
1798 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
1799 	if (error)
1800 		goto error_nond;
1801 
1802 	error = nlookup(&nd);
1803 	if (error)
1804 		goto error_out;
1805 
1806 	nch = &nd.nl_nch;
1807 
1808 	error = priv_check_cred(td->td_ucred, PRIV_VFS_CHROOT, 0);
1809 	if (error)
1810 		goto error_out;
1811 
1812 	if ((vp = nch->ncp->nc_vp) == NULL) {
1813 		error = ENOENT;
1814 		goto error_out;
1815 	}
1816 
1817 	if ((error = cache_vref(nch, nd.nl_cred, &vp)) != 0)
1818 		goto error_out;
1819 
1820 	kprintf("chroot_kernel: set new rootnch/rootvnode to %s\n", uap->path);
1821 	get_mplock();
1822 	vfs_cache_setroot(vp, cache_hold(nch));
1823 	rel_mplock();
1824 
1825 error_out:
1826 	nlookup_done(&nd);
1827 error_nond:
1828 	return(error);
1829 }
1830 
1831 /*
1832  * Common routine for chroot and chdir.  Given a locked, referenced vnode,
1833  * determine whether it is legal to chdir to the vnode.  The vnode's state
1834  * is not changed by this call.
1835  */
1836 static int
1837 checkvp_chdir(struct vnode *vp, struct thread *td)
1838 {
1839 	int error;
1840 
1841 	if (vp->v_type != VDIR)
1842 		error = ENOTDIR;
1843 	else
1844 		error = VOP_EACCESS(vp, VEXEC, td->td_ucred);
1845 	return (error);
1846 }
1847 
1848 int
1849 kern_open(struct nlookupdata *nd, int oflags, int mode, int *res)
1850 {
1851 	struct thread *td = curthread;
1852 	struct proc *p = td->td_proc;
1853 	struct lwp *lp = td->td_lwp;
1854 	struct filedesc *fdp = p->p_fd;
1855 	int cmode, flags;
1856 	struct file *nfp;
1857 	struct file *fp;
1858 	struct vnode *vp;
1859 	int type, indx, error = 0;
1860 	struct flock lf;
1861 
1862 	if ((oflags & O_ACCMODE) == O_ACCMODE)
1863 		return (EINVAL);
1864 	flags = FFLAGS(oflags);
1865 	error = falloc(lp, &nfp, NULL);
1866 	if (error)
1867 		return (error);
1868 	fp = nfp;
1869 	cmode = ((mode &~ fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT;
1870 
1871 	/*
1872 	 * XXX p_dupfd is a real mess.  It allows a device to return a
1873 	 * file descriptor to be duplicated rather then doing the open
1874 	 * itself.
1875 	 */
1876 	lp->lwp_dupfd = -1;
1877 
1878 	/*
1879 	 * Call vn_open() to do the lookup and assign the vnode to the
1880 	 * file pointer.  vn_open() does not change the ref count on fp
1881 	 * and the vnode, on success, will be inherited by the file pointer
1882 	 * and unlocked.
1883 	 *
1884 	 * Request a shared lock on the vnode if possible.
1885 	 */
1886 	nd->nl_flags |= NLC_LOCKVP;
1887 	if ((flags & (O_CREAT|O_TRUNC)) == 0)
1888 		nd->nl_flags |= NLC_SHAREDLOCK;
1889 
1890 	error = vn_open(nd, fp, flags, cmode);
1891 	nlookup_done(nd);
1892 
1893 	if (error) {
1894 		/*
1895 		 * handle special fdopen() case.  bleh.  dupfdopen() is
1896 		 * responsible for dropping the old contents of ofiles[indx]
1897 		 * if it succeeds.
1898 		 *
1899 		 * Note that fsetfd() will add a ref to fp which represents
1900 		 * the fd_files[] assignment.  We must still drop our
1901 		 * reference.
1902 		 */
1903 		if ((error == ENODEV || error == ENXIO) && lp->lwp_dupfd >= 0) {
1904 			if (fdalloc(p, 0, &indx) == 0) {
1905 				error = dupfdopen(fdp, indx, lp->lwp_dupfd, flags, error);
1906 				if (error == 0) {
1907 					*res = indx;
1908 					fdrop(fp);	/* our ref */
1909 					return (0);
1910 				}
1911 				fsetfd(fdp, NULL, indx);
1912 			}
1913 		}
1914 		fdrop(fp);	/* our ref */
1915 		if (error == ERESTART)
1916 			error = EINTR;
1917 		return (error);
1918 	}
1919 
1920 	/*
1921 	 * ref the vnode for ourselves so it can't be ripped out from under
1922 	 * is.  XXX need an ND flag to request that the vnode be returned
1923 	 * anyway.
1924 	 *
1925 	 * Reserve a file descriptor but do not assign it until the open
1926 	 * succeeds.
1927 	 */
1928 	vp = (struct vnode *)fp->f_data;
1929 	vref(vp);
1930 	if ((error = fdalloc(p, 0, &indx)) != 0) {
1931 		fdrop(fp);
1932 		vrele(vp);
1933 		return (error);
1934 	}
1935 
1936 	/*
1937 	 * If no error occurs the vp will have been assigned to the file
1938 	 * pointer.
1939 	 */
1940 	lp->lwp_dupfd = 0;
1941 
1942 	if (flags & (O_EXLOCK | O_SHLOCK)) {
1943 		lf.l_whence = SEEK_SET;
1944 		lf.l_start = 0;
1945 		lf.l_len = 0;
1946 		if (flags & O_EXLOCK)
1947 			lf.l_type = F_WRLCK;
1948 		else
1949 			lf.l_type = F_RDLCK;
1950 		if (flags & FNONBLOCK)
1951 			type = 0;
1952 		else
1953 			type = F_WAIT;
1954 
1955 		if ((error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type)) != 0) {
1956 			/*
1957 			 * lock request failed.  Clean up the reserved
1958 			 * descriptor.
1959 			 */
1960 			vrele(vp);
1961 			fsetfd(fdp, NULL, indx);
1962 			fdrop(fp);
1963 			return (error);
1964 		}
1965 		atomic_set_int(&fp->f_flag, FHASLOCK); /* race ok */
1966 	}
1967 #if 0
1968 	/*
1969 	 * Assert that all regular file vnodes were created with a object.
1970 	 */
1971 	KASSERT(vp->v_type != VREG || vp->v_object != NULL,
1972 		("open: regular file has no backing object after vn_open"));
1973 #endif
1974 
1975 	vrele(vp);
1976 
1977 	/*
1978 	 * release our private reference, leaving the one associated with the
1979 	 * descriptor table intact.
1980 	 */
1981 	if (oflags & O_CLOEXEC)
1982 		fdp->fd_files[indx].fileflags |= UF_EXCLOSE;
1983 	fsetfd(fdp, fp, indx);
1984 	fdrop(fp);
1985 	*res = indx;
1986 	return (error);
1987 }
1988 
1989 /*
1990  * open_args(char *path, int flags, int mode)
1991  *
1992  * Check permissions, allocate an open file structure,
1993  * and call the device open routine if any.
1994  */
1995 int
1996 sys_open(struct open_args *uap)
1997 {
1998 	struct nlookupdata nd;
1999 	int error;
2000 
2001 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2002 	if (error == 0) {
2003 		error = kern_open(&nd, uap->flags,
2004 				    uap->mode, &uap->sysmsg_result);
2005 	}
2006 	nlookup_done(&nd);
2007 	return (error);
2008 }
2009 
2010 /*
2011  * openat_args(int fd, char *path, int flags, int mode)
2012  */
2013 int
2014 sys_openat(struct openat_args *uap)
2015 {
2016 	struct nlookupdata nd;
2017 	int error;
2018 	struct file *fp;
2019 
2020 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path, UIO_USERSPACE, 0);
2021 	if (error == 0) {
2022 		error = kern_open(&nd, uap->flags, uap->mode,
2023 					&uap->sysmsg_result);
2024 	}
2025 	nlookup_done_at(&nd, fp);
2026 	return (error);
2027 }
2028 
2029 int
2030 kern_mknod(struct nlookupdata *nd, int mode, int rmajor, int rminor)
2031 {
2032 	struct thread *td = curthread;
2033 	struct proc *p = td->td_proc;
2034 	struct vnode *vp;
2035 	struct vattr vattr;
2036 	int error;
2037 	int whiteout = 0;
2038 
2039 	KKASSERT(p);
2040 
2041 	VATTR_NULL(&vattr);
2042 	vattr.va_mode = (mode & ALLPERMS) &~ p->p_fd->fd_cmask;
2043 	vattr.va_rmajor = rmajor;
2044 	vattr.va_rminor = rminor;
2045 
2046 	switch (mode & S_IFMT) {
2047 	case S_IFMT:	/* used by badsect to flag bad sectors */
2048 		error = priv_check_cred(td->td_ucred, PRIV_VFS_MKNOD_BAD, 0);
2049 		vattr.va_type = VBAD;
2050 		break;
2051 	case S_IFCHR:
2052 		error = priv_check(td, PRIV_VFS_MKNOD_DEV);
2053 		vattr.va_type = VCHR;
2054 		break;
2055 	case S_IFBLK:
2056 		error = priv_check(td, PRIV_VFS_MKNOD_DEV);
2057 		vattr.va_type = VBLK;
2058 		break;
2059 	case S_IFWHT:
2060 		error = priv_check_cred(td->td_ucred, PRIV_VFS_MKNOD_WHT, 0);
2061 		whiteout = 1;
2062 		break;
2063 	case S_IFDIR:	/* special directories support for HAMMER */
2064 		error = priv_check_cred(td->td_ucred, PRIV_VFS_MKNOD_DIR, 0);
2065 		vattr.va_type = VDIR;
2066 		break;
2067 	default:
2068 		error = EINVAL;
2069 		break;
2070 	}
2071 
2072 	if (error)
2073 		return (error);
2074 
2075 	bwillinode(1);
2076 	nd->nl_flags |= NLC_CREATE | NLC_REFDVP;
2077 	if ((error = nlookup(nd)) != 0)
2078 		return (error);
2079 	if (nd->nl_nch.ncp->nc_vp)
2080 		return (EEXIST);
2081 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2082 		return (error);
2083 
2084 	if (whiteout) {
2085 		error = VOP_NWHITEOUT(&nd->nl_nch, nd->nl_dvp,
2086 				      nd->nl_cred, NAMEI_CREATE);
2087 	} else {
2088 		vp = NULL;
2089 		error = VOP_NMKNOD(&nd->nl_nch, nd->nl_dvp,
2090 				   &vp, nd->nl_cred, &vattr);
2091 		if (error == 0)
2092 			vput(vp);
2093 	}
2094 	return (error);
2095 }
2096 
2097 /*
2098  * mknod_args(char *path, int mode, int dev)
2099  *
2100  * Create a special file.
2101  */
2102 int
2103 sys_mknod(struct mknod_args *uap)
2104 {
2105 	struct nlookupdata nd;
2106 	int error;
2107 
2108 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2109 	if (error == 0) {
2110 		error = kern_mknod(&nd, uap->mode,
2111 				   umajor(uap->dev), uminor(uap->dev));
2112 	}
2113 	nlookup_done(&nd);
2114 	return (error);
2115 }
2116 
2117 /*
2118  * mknodat_args(int fd, char *path, mode_t mode, dev_t dev)
2119  *
2120  * Create a special file.  The path is relative to the directory associated
2121  * with fd.
2122  */
2123 int
2124 sys_mknodat(struct mknodat_args *uap)
2125 {
2126 	struct nlookupdata nd;
2127 	struct file *fp;
2128 	int error;
2129 
2130 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path, UIO_USERSPACE, 0);
2131 	if (error == 0) {
2132 		error = kern_mknod(&nd, uap->mode,
2133 				   umajor(uap->dev), uminor(uap->dev));
2134 	}
2135 	nlookup_done_at(&nd, fp);
2136 	return (error);
2137 }
2138 
2139 int
2140 kern_mkfifo(struct nlookupdata *nd, int mode)
2141 {
2142 	struct thread *td = curthread;
2143 	struct proc *p = td->td_proc;
2144 	struct vattr vattr;
2145 	struct vnode *vp;
2146 	int error;
2147 
2148 	bwillinode(1);
2149 
2150 	nd->nl_flags |= NLC_CREATE | NLC_REFDVP;
2151 	if ((error = nlookup(nd)) != 0)
2152 		return (error);
2153 	if (nd->nl_nch.ncp->nc_vp)
2154 		return (EEXIST);
2155 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2156 		return (error);
2157 
2158 	VATTR_NULL(&vattr);
2159 	vattr.va_type = VFIFO;
2160 	vattr.va_mode = (mode & ALLPERMS) &~ p->p_fd->fd_cmask;
2161 	vp = NULL;
2162 	error = VOP_NMKNOD(&nd->nl_nch, nd->nl_dvp, &vp, nd->nl_cred, &vattr);
2163 	if (error == 0)
2164 		vput(vp);
2165 	return (error);
2166 }
2167 
2168 /*
2169  * mkfifo_args(char *path, int mode)
2170  *
2171  * Create a named pipe.
2172  */
2173 int
2174 sys_mkfifo(struct mkfifo_args *uap)
2175 {
2176 	struct nlookupdata nd;
2177 	int error;
2178 
2179 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2180 	if (error == 0)
2181 		error = kern_mkfifo(&nd, uap->mode);
2182 	nlookup_done(&nd);
2183 	return (error);
2184 }
2185 
2186 /*
2187  * mkfifoat_args(int fd, char *path, mode_t mode)
2188  *
2189  * Create a named pipe.  The path is relative to the directory associated
2190  * with fd.
2191  */
2192 int
2193 sys_mkfifoat(struct mkfifoat_args *uap)
2194 {
2195 	struct nlookupdata nd;
2196 	struct file *fp;
2197 	int error;
2198 
2199 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path, UIO_USERSPACE, 0);
2200 	if (error == 0)
2201 		error = kern_mkfifo(&nd, uap->mode);
2202 	nlookup_done_at(&nd, fp);
2203 	return (error);
2204 }
2205 
2206 static int hardlink_check_uid = 0;
2207 SYSCTL_INT(_security, OID_AUTO, hardlink_check_uid, CTLFLAG_RW,
2208     &hardlink_check_uid, 0,
2209     "Unprivileged processes cannot create hard links to files owned by other "
2210     "users");
2211 static int hardlink_check_gid = 0;
2212 SYSCTL_INT(_security, OID_AUTO, hardlink_check_gid, CTLFLAG_RW,
2213     &hardlink_check_gid, 0,
2214     "Unprivileged processes cannot create hard links to files owned by other "
2215     "groups");
2216 
2217 static int
2218 can_hardlink(struct vnode *vp, struct thread *td, struct ucred *cred)
2219 {
2220 	struct vattr va;
2221 	int error;
2222 
2223 	/*
2224 	 * Shortcut if disabled
2225 	 */
2226 	if (hardlink_check_uid == 0 && hardlink_check_gid == 0)
2227 		return (0);
2228 
2229 	/*
2230 	 * Privileged user can always hardlink
2231 	 */
2232 	if (priv_check_cred(cred, PRIV_VFS_LINK, 0) == 0)
2233 		return (0);
2234 
2235 	/*
2236 	 * Otherwise only if the originating file is owned by the
2237 	 * same user or group.  Note that any group is allowed if
2238 	 * the file is owned by the caller.
2239 	 */
2240 	error = VOP_GETATTR(vp, &va);
2241 	if (error != 0)
2242 		return (error);
2243 
2244 	if (hardlink_check_uid) {
2245 		if (cred->cr_uid != va.va_uid)
2246 			return (EPERM);
2247 	}
2248 
2249 	if (hardlink_check_gid) {
2250 		if (cred->cr_uid != va.va_uid && !groupmember(va.va_gid, cred))
2251 			return (EPERM);
2252 	}
2253 
2254 	return (0);
2255 }
2256 
2257 int
2258 kern_link(struct nlookupdata *nd, struct nlookupdata *linknd)
2259 {
2260 	struct thread *td = curthread;
2261 	struct vnode *vp;
2262 	int error;
2263 
2264 	/*
2265 	 * Lookup the source and obtained a locked vnode.
2266 	 *
2267 	 * You may only hardlink a file which you have write permission
2268 	 * on or which you own.
2269 	 *
2270 	 * XXX relookup on vget failure / race ?
2271 	 */
2272 	bwillinode(1);
2273 	nd->nl_flags |= NLC_WRITE | NLC_OWN | NLC_HLINK;
2274 	if ((error = nlookup(nd)) != 0)
2275 		return (error);
2276 	vp = nd->nl_nch.ncp->nc_vp;
2277 	KKASSERT(vp != NULL);
2278 	if (vp->v_type == VDIR)
2279 		return (EPERM);		/* POSIX */
2280 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2281 		return (error);
2282 	if ((error = vget(vp, LK_EXCLUSIVE)) != 0)
2283 		return (error);
2284 
2285 	/*
2286 	 * Unlock the source so we can lookup the target without deadlocking
2287 	 * (XXX vp is locked already, possible other deadlock?).  The target
2288 	 * must not exist.
2289 	 */
2290 	KKASSERT(nd->nl_flags & NLC_NCPISLOCKED);
2291 	nd->nl_flags &= ~NLC_NCPISLOCKED;
2292 	cache_unlock(&nd->nl_nch);
2293 	vn_unlock(vp);
2294 
2295 	linknd->nl_flags |= NLC_CREATE | NLC_REFDVP;
2296 	if ((error = nlookup(linknd)) != 0) {
2297 		vrele(vp);
2298 		return (error);
2299 	}
2300 	if (linknd->nl_nch.ncp->nc_vp) {
2301 		vrele(vp);
2302 		return (EEXIST);
2303 	}
2304 	error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM);
2305 	if (error) {
2306 		vrele(vp);
2307 		return (error);
2308 	}
2309 
2310 	/*
2311 	 * Finally run the new API VOP.
2312 	 */
2313 	error = can_hardlink(vp, td, td->td_ucred);
2314 	if (error == 0) {
2315 		error = VOP_NLINK(&linknd->nl_nch, linknd->nl_dvp,
2316 				  vp, linknd->nl_cred);
2317 	}
2318 	vput(vp);
2319 	return (error);
2320 }
2321 
2322 /*
2323  * link_args(char *path, char *link)
2324  *
2325  * Make a hard file link.
2326  */
2327 int
2328 sys_link(struct link_args *uap)
2329 {
2330 	struct nlookupdata nd, linknd;
2331 	int error;
2332 
2333 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2334 	if (error == 0) {
2335 		error = nlookup_init(&linknd, uap->link, UIO_USERSPACE, 0);
2336 		if (error == 0)
2337 			error = kern_link(&nd, &linknd);
2338 		nlookup_done(&linknd);
2339 	}
2340 	nlookup_done(&nd);
2341 	return (error);
2342 }
2343 
2344 /*
2345  * linkat_args(int fd1, char *path1, int fd2, char *path2, int flags)
2346  *
2347  * Make a hard file link. The path1 argument is relative to the directory
2348  * associated with fd1, and similarly the path2 argument is relative to
2349  * the directory associated with fd2.
2350  */
2351 int
2352 sys_linkat(struct linkat_args *uap)
2353 {
2354 	struct nlookupdata nd, linknd;
2355 	struct file *fp1, *fp2;
2356 	int error;
2357 
2358 	error = nlookup_init_at(&nd, &fp1, uap->fd1, uap->path1, UIO_USERSPACE,
2359 	    (uap->flags & AT_SYMLINK_FOLLOW) ? NLC_FOLLOW : 0);
2360 	if (error == 0) {
2361 		error = nlookup_init_at(&linknd, &fp2, uap->fd2,
2362 		    uap->path2, UIO_USERSPACE, 0);
2363 		if (error == 0)
2364 			error = kern_link(&nd, &linknd);
2365 		nlookup_done_at(&linknd, fp2);
2366 	}
2367 	nlookup_done_at(&nd, fp1);
2368 	return (error);
2369 }
2370 
2371 int
2372 kern_symlink(struct nlookupdata *nd, char *path, int mode)
2373 {
2374 	struct vattr vattr;
2375 	struct vnode *vp;
2376 	struct vnode *dvp;
2377 	int error;
2378 
2379 	bwillinode(1);
2380 	nd->nl_flags |= NLC_CREATE | NLC_REFDVP;
2381 	if ((error = nlookup(nd)) != 0)
2382 		return (error);
2383 	if (nd->nl_nch.ncp->nc_vp)
2384 		return (EEXIST);
2385 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2386 		return (error);
2387 	dvp = nd->nl_dvp;
2388 	VATTR_NULL(&vattr);
2389 	vattr.va_mode = mode;
2390 	error = VOP_NSYMLINK(&nd->nl_nch, dvp, &vp, nd->nl_cred, &vattr, path);
2391 	if (error == 0)
2392 		vput(vp);
2393 	return (error);
2394 }
2395 
2396 /*
2397  * symlink(char *path, char *link)
2398  *
2399  * Make a symbolic link.
2400  */
2401 int
2402 sys_symlink(struct symlink_args *uap)
2403 {
2404 	struct thread *td = curthread;
2405 	struct nlookupdata nd;
2406 	char *path;
2407 	int error;
2408 	int mode;
2409 
2410 	path = objcache_get(namei_oc, M_WAITOK);
2411 	error = copyinstr(uap->path, path, MAXPATHLEN, NULL);
2412 	if (error == 0) {
2413 		error = nlookup_init(&nd, uap->link, UIO_USERSPACE, 0);
2414 		if (error == 0) {
2415 			mode = ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask;
2416 			error = kern_symlink(&nd, path, mode);
2417 		}
2418 		nlookup_done(&nd);
2419 	}
2420 	objcache_put(namei_oc, path);
2421 	return (error);
2422 }
2423 
2424 /*
2425  * symlinkat_args(char *path1, int fd, char *path2)
2426  *
2427  * Make a symbolic link.  The path2 argument is relative to the directory
2428  * associated with fd.
2429  */
2430 int
2431 sys_symlinkat(struct symlinkat_args *uap)
2432 {
2433 	struct thread *td = curthread;
2434 	struct nlookupdata nd;
2435 	struct file *fp;
2436 	char *path1;
2437 	int error;
2438 	int mode;
2439 
2440 	path1 = objcache_get(namei_oc, M_WAITOK);
2441 	error = copyinstr(uap->path1, path1, MAXPATHLEN, NULL);
2442 	if (error == 0) {
2443 		error = nlookup_init_at(&nd, &fp, uap->fd, uap->path2,
2444 		    UIO_USERSPACE, 0);
2445 		if (error == 0) {
2446 			mode = ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask;
2447 			error = kern_symlink(&nd, path1, mode);
2448 		}
2449 		nlookup_done_at(&nd, fp);
2450 	}
2451 	objcache_put(namei_oc, path1);
2452 	return (error);
2453 }
2454 
2455 /*
2456  * undelete_args(char *path)
2457  *
2458  * Delete a whiteout from the filesystem.
2459  */
2460 int
2461 sys_undelete(struct undelete_args *uap)
2462 {
2463 	struct nlookupdata nd;
2464 	int error;
2465 
2466 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2467 	bwillinode(1);
2468 	nd.nl_flags |= NLC_DELETE | NLC_REFDVP;
2469 	if (error == 0)
2470 		error = nlookup(&nd);
2471 	if (error == 0)
2472 		error = ncp_writechk(&nd.nl_nch);
2473 	if (error == 0) {
2474 		error = VOP_NWHITEOUT(&nd.nl_nch, nd.nl_dvp, nd.nl_cred,
2475 				      NAMEI_DELETE);
2476 	}
2477 	nlookup_done(&nd);
2478 	return (error);
2479 }
2480 
2481 int
2482 kern_unlink(struct nlookupdata *nd)
2483 {
2484 	int error;
2485 
2486 	bwillinode(1);
2487 	nd->nl_flags |= NLC_DELETE | NLC_REFDVP;
2488 	if ((error = nlookup(nd)) != 0)
2489 		return (error);
2490 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
2491 		return (error);
2492 	error = VOP_NREMOVE(&nd->nl_nch, nd->nl_dvp, nd->nl_cred);
2493 	return (error);
2494 }
2495 
2496 /*
2497  * unlink_args(char *path)
2498  *
2499  * Delete a name from the filesystem.
2500  */
2501 int
2502 sys_unlink(struct unlink_args *uap)
2503 {
2504 	struct nlookupdata nd;
2505 	int error;
2506 
2507 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2508 	if (error == 0)
2509 		error = kern_unlink(&nd);
2510 	nlookup_done(&nd);
2511 	return (error);
2512 }
2513 
2514 
2515 /*
2516  * unlinkat_args(int fd, char *path, int flags)
2517  *
2518  * Delete the file or directory entry pointed to by fd/path.
2519  */
2520 int
2521 sys_unlinkat(struct unlinkat_args *uap)
2522 {
2523 	struct nlookupdata nd;
2524 	struct file *fp;
2525 	int error;
2526 
2527 	if (uap->flags & ~AT_REMOVEDIR)
2528 		return (EINVAL);
2529 
2530 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path, UIO_USERSPACE, 0);
2531 	if (error == 0) {
2532 		if (uap->flags & AT_REMOVEDIR)
2533 			error = kern_rmdir(&nd);
2534 		else
2535 			error = kern_unlink(&nd);
2536 	}
2537 	nlookup_done_at(&nd, fp);
2538 	return (error);
2539 }
2540 
2541 int
2542 kern_lseek(int fd, off_t offset, int whence, off_t *res)
2543 {
2544 	struct thread *td = curthread;
2545 	struct proc *p = td->td_proc;
2546 	struct file *fp;
2547 	struct vnode *vp;
2548 	struct vattr vattr;
2549 	off_t new_offset;
2550 	int error;
2551 
2552 	fp = holdfp(p->p_fd, fd, -1);
2553 	if (fp == NULL)
2554 		return (EBADF);
2555 	if (fp->f_type != DTYPE_VNODE) {
2556 		error = ESPIPE;
2557 		goto done;
2558 	}
2559 	vp = (struct vnode *)fp->f_data;
2560 
2561 	switch (whence) {
2562 	case L_INCR:
2563 		spin_lock(&fp->f_spin);
2564 		new_offset = fp->f_offset + offset;
2565 		error = 0;
2566 		break;
2567 	case L_XTND:
2568 		error = VOP_GETATTR(vp, &vattr);
2569 		spin_lock(&fp->f_spin);
2570 		new_offset = offset + vattr.va_size;
2571 		break;
2572 	case L_SET:
2573 		new_offset = offset;
2574 		error = 0;
2575 		spin_lock(&fp->f_spin);
2576 		break;
2577 	default:
2578 		new_offset = 0;
2579 		error = EINVAL;
2580 		spin_lock(&fp->f_spin);
2581 		break;
2582 	}
2583 
2584 	/*
2585 	 * Validate the seek position.  Negative offsets are not allowed
2586 	 * for regular files or directories.
2587 	 *
2588 	 * Normally we would also not want to allow negative offsets for
2589 	 * character and block-special devices.  However kvm addresses
2590 	 * on 64 bit architectures might appear to be negative and must
2591 	 * be allowed.
2592 	 */
2593 	if (error == 0) {
2594 		if (new_offset < 0 &&
2595 		    (vp->v_type == VREG || vp->v_type == VDIR)) {
2596 			error = EINVAL;
2597 		} else {
2598 			fp->f_offset = new_offset;
2599 		}
2600 	}
2601 	*res = fp->f_offset;
2602 	spin_unlock(&fp->f_spin);
2603 done:
2604 	fdrop(fp);
2605 	return (error);
2606 }
2607 
2608 /*
2609  * lseek_args(int fd, int pad, off_t offset, int whence)
2610  *
2611  * Reposition read/write file offset.
2612  */
2613 int
2614 sys_lseek(struct lseek_args *uap)
2615 {
2616 	int error;
2617 
2618 	error = kern_lseek(uap->fd, uap->offset, uap->whence,
2619 			   &uap->sysmsg_offset);
2620 
2621 	return (error);
2622 }
2623 
2624 /*
2625  * Check if current process can access given file.  amode is a bitmask of *_OK
2626  * access bits.  flags is a bitmask of AT_* flags.
2627  */
2628 int
2629 kern_access(struct nlookupdata *nd, int amode, int flags)
2630 {
2631 	struct vnode *vp;
2632 	int error, mode;
2633 
2634 	if (flags & ~AT_EACCESS)
2635 		return (EINVAL);
2636 	nd->nl_flags |= NLC_SHAREDLOCK;
2637 	if ((error = nlookup(nd)) != 0)
2638 		return (error);
2639 retry:
2640 	error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_SHARED, &vp);
2641 	if (error)
2642 		return (error);
2643 
2644 	/* Flags == 0 means only check for existence. */
2645 	if (amode) {
2646 		mode = 0;
2647 		if (amode & R_OK)
2648 			mode |= VREAD;
2649 		if (amode & W_OK)
2650 			mode |= VWRITE;
2651 		if (amode & X_OK)
2652 			mode |= VEXEC;
2653 		if ((mode & VWRITE) == 0 ||
2654 		    (error = vn_writechk(vp, &nd->nl_nch)) == 0)
2655 			error = VOP_ACCESS_FLAGS(vp, mode, flags, nd->nl_cred);
2656 
2657 		/*
2658 		 * If the file handle is stale we have to re-resolve the
2659 		 * entry with the ncp held exclusively.  This is a hack
2660 		 * at the moment.
2661 		 */
2662 		if (error == ESTALE) {
2663 			vput(vp);
2664 			cache_unlock(&nd->nl_nch);
2665 			cache_lock(&nd->nl_nch);
2666 			cache_setunresolved(&nd->nl_nch);
2667 			error = cache_resolve(&nd->nl_nch, nd->nl_cred);
2668 			if (error == 0) {
2669 				vp = NULL;
2670 				goto retry;
2671 			}
2672 			return(error);
2673 		}
2674 	}
2675 	vput(vp);
2676 	return (error);
2677 }
2678 
2679 /*
2680  * access_args(char *path, int flags)
2681  *
2682  * Check access permissions.
2683  */
2684 int
2685 sys_access(struct access_args *uap)
2686 {
2687 	struct nlookupdata nd;
2688 	int error;
2689 
2690 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2691 	if (error == 0)
2692 		error = kern_access(&nd, uap->flags, 0);
2693 	nlookup_done(&nd);
2694 	return (error);
2695 }
2696 
2697 
2698 /*
2699  * eaccess_args(char *path, int flags)
2700  *
2701  * Check access permissions.
2702  */
2703 int
2704 sys_eaccess(struct eaccess_args *uap)
2705 {
2706 	struct nlookupdata nd;
2707 	int error;
2708 
2709 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2710 	if (error == 0)
2711 		error = kern_access(&nd, uap->flags, AT_EACCESS);
2712 	nlookup_done(&nd);
2713 	return (error);
2714 }
2715 
2716 
2717 /*
2718  * faccessat_args(int fd, char *path, int amode, int flags)
2719  *
2720  * Check access permissions.
2721  */
2722 int
2723 sys_faccessat(struct faccessat_args *uap)
2724 {
2725 	struct nlookupdata nd;
2726 	struct file *fp;
2727 	int error;
2728 
2729 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path, UIO_USERSPACE,
2730 				NLC_FOLLOW);
2731 	if (error == 0)
2732 		error = kern_access(&nd, uap->amode, uap->flags);
2733 	nlookup_done_at(&nd, fp);
2734 	return (error);
2735 }
2736 
2737 int
2738 kern_stat(struct nlookupdata *nd, struct stat *st)
2739 {
2740 	int error;
2741 	struct vnode *vp;
2742 
2743 	nd->nl_flags |= NLC_SHAREDLOCK;
2744 	if ((error = nlookup(nd)) != 0)
2745 		return (error);
2746 again:
2747 	if ((vp = nd->nl_nch.ncp->nc_vp) == NULL)
2748 		return (ENOENT);
2749 
2750 	if ((error = vget(vp, LK_SHARED)) != 0)
2751 		return (error);
2752 	error = vn_stat(vp, st, nd->nl_cred);
2753 
2754 	/*
2755 	 * If the file handle is stale we have to re-resolve the
2756 	 * entry with the ncp held exclusively.  This is a hack
2757 	 * at the moment.
2758 	 */
2759 	if (error == ESTALE) {
2760 		vput(vp);
2761 		cache_unlock(&nd->nl_nch);
2762 		cache_lock(&nd->nl_nch);
2763 		cache_setunresolved(&nd->nl_nch);
2764 		error = cache_resolve(&nd->nl_nch, nd->nl_cred);
2765 		if (error == 0)
2766 			goto again;
2767 	} else {
2768 		vput(vp);
2769 	}
2770 	return (error);
2771 }
2772 
2773 /*
2774  * stat_args(char *path, struct stat *ub)
2775  *
2776  * Get file status; this version follows links.
2777  */
2778 int
2779 sys_stat(struct stat_args *uap)
2780 {
2781 	struct nlookupdata nd;
2782 	struct stat st;
2783 	int error;
2784 
2785 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
2786 	if (error == 0) {
2787 		error = kern_stat(&nd, &st);
2788 		if (error == 0)
2789 			error = copyout(&st, uap->ub, sizeof(*uap->ub));
2790 	}
2791 	nlookup_done(&nd);
2792 	return (error);
2793 }
2794 
2795 /*
2796  * lstat_args(char *path, struct stat *ub)
2797  *
2798  * Get file status; this version does not follow links.
2799  */
2800 int
2801 sys_lstat(struct lstat_args *uap)
2802 {
2803 	struct nlookupdata nd;
2804 	struct stat st;
2805 	int error;
2806 
2807 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2808 	if (error == 0) {
2809 		error = kern_stat(&nd, &st);
2810 		if (error == 0)
2811 			error = copyout(&st, uap->ub, sizeof(*uap->ub));
2812 	}
2813 	nlookup_done(&nd);
2814 	return (error);
2815 }
2816 
2817 /*
2818  * fstatat_args(int fd, char *path, struct stat *sb, int flags)
2819  *
2820  * Get status of file pointed to by fd/path.
2821  */
2822 int
2823 sys_fstatat(struct fstatat_args *uap)
2824 {
2825 	struct nlookupdata nd;
2826 	struct stat st;
2827 	int error;
2828 	int flags;
2829 	struct file *fp;
2830 
2831 	if (uap->flags & ~AT_SYMLINK_NOFOLLOW)
2832 		return (EINVAL);
2833 
2834 	flags = (uap->flags & AT_SYMLINK_NOFOLLOW) ? 0 : NLC_FOLLOW;
2835 
2836 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path,
2837 				UIO_USERSPACE, flags);
2838 	if (error == 0) {
2839 		error = kern_stat(&nd, &st);
2840 		if (error == 0)
2841 			error = copyout(&st, uap->sb, sizeof(*uap->sb));
2842 	}
2843 	nlookup_done_at(&nd, fp);
2844 	return (error);
2845 }
2846 
2847 static int
2848 kern_pathconf(char *path, int name, int flags, register_t *sysmsg_regp)
2849 {
2850 	struct nlookupdata nd;
2851 	struct vnode *vp;
2852 	int error;
2853 
2854 	vp = NULL;
2855 	error = nlookup_init(&nd, path, UIO_USERSPACE, flags);
2856 	if (error == 0)
2857 		error = nlookup(&nd);
2858 	if (error == 0)
2859 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
2860 	nlookup_done(&nd);
2861 	if (error == 0) {
2862 		error = VOP_PATHCONF(vp, name, sysmsg_regp);
2863 		vput(vp);
2864 	}
2865 	return (error);
2866 }
2867 
2868 /*
2869  * pathconf_Args(char *path, int name)
2870  *
2871  * Get configurable pathname variables.
2872  */
2873 int
2874 sys_pathconf(struct pathconf_args *uap)
2875 {
2876 	return (kern_pathconf(uap->path, uap->name, NLC_FOLLOW,
2877 		&uap->sysmsg_reg));
2878 }
2879 
2880 /*
2881  * lpathconf_Args(char *path, int name)
2882  *
2883  * Get configurable pathname variables, but don't follow symlinks.
2884  */
2885 int
2886 sys_lpathconf(struct lpathconf_args *uap)
2887 {
2888 	return (kern_pathconf(uap->path, uap->name, 0, &uap->sysmsg_reg));
2889 }
2890 
2891 /*
2892  * XXX: daver
2893  * kern_readlink isn't properly split yet.  There is a copyin burried
2894  * in VOP_READLINK().
2895  */
2896 int
2897 kern_readlink(struct nlookupdata *nd, char *buf, int count, int *res)
2898 {
2899 	struct thread *td = curthread;
2900 	struct vnode *vp;
2901 	struct iovec aiov;
2902 	struct uio auio;
2903 	int error;
2904 
2905 	nd->nl_flags |= NLC_SHAREDLOCK;
2906 	if ((error = nlookup(nd)) != 0)
2907 		return (error);
2908 	error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_SHARED, &vp);
2909 	if (error)
2910 		return (error);
2911 	if (vp->v_type != VLNK) {
2912 		error = EINVAL;
2913 	} else {
2914 		aiov.iov_base = buf;
2915 		aiov.iov_len = count;
2916 		auio.uio_iov = &aiov;
2917 		auio.uio_iovcnt = 1;
2918 		auio.uio_offset = 0;
2919 		auio.uio_rw = UIO_READ;
2920 		auio.uio_segflg = UIO_USERSPACE;
2921 		auio.uio_td = td;
2922 		auio.uio_resid = count;
2923 		error = VOP_READLINK(vp, &auio, td->td_ucred);
2924 	}
2925 	vput(vp);
2926 	*res = count - auio.uio_resid;
2927 	return (error);
2928 }
2929 
2930 /*
2931  * readlink_args(char *path, char *buf, int count)
2932  *
2933  * Return target name of a symbolic link.
2934  */
2935 int
2936 sys_readlink(struct readlink_args *uap)
2937 {
2938 	struct nlookupdata nd;
2939 	int error;
2940 
2941 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
2942 	if (error == 0) {
2943 		error = kern_readlink(&nd, uap->buf, uap->count,
2944 					&uap->sysmsg_result);
2945 	}
2946 	nlookup_done(&nd);
2947 	return (error);
2948 }
2949 
2950 /*
2951  * readlinkat_args(int fd, char *path, char *buf, size_t bufsize)
2952  *
2953  * Return target name of a symbolic link.  The path is relative to the
2954  * directory associated with fd.
2955  */
2956 int
2957 sys_readlinkat(struct readlinkat_args *uap)
2958 {
2959 	struct nlookupdata nd;
2960 	struct file *fp;
2961 	int error;
2962 
2963 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path, UIO_USERSPACE, 0);
2964 	if (error == 0) {
2965 		error = kern_readlink(&nd, uap->buf, uap->bufsize,
2966 					&uap->sysmsg_result);
2967 	}
2968 	nlookup_done_at(&nd, fp);
2969 	return (error);
2970 }
2971 
2972 static int
2973 setfflags(struct vnode *vp, int flags)
2974 {
2975 	struct thread *td = curthread;
2976 	int error;
2977 	struct vattr vattr;
2978 
2979 	/*
2980 	 * Prevent non-root users from setting flags on devices.  When
2981 	 * a device is reused, users can retain ownership of the device
2982 	 * if they are allowed to set flags and programs assume that
2983 	 * chown can't fail when done as root.
2984 	 */
2985 	if ((vp->v_type == VCHR || vp->v_type == VBLK) &&
2986 	    ((error = priv_check_cred(td->td_ucred, PRIV_VFS_CHFLAGS_DEV, 0)) != 0))
2987 		return (error);
2988 
2989 	/*
2990 	 * note: vget is required for any operation that might mod the vnode
2991 	 * so VINACTIVE is properly cleared.
2992 	 */
2993 	if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
2994 		VATTR_NULL(&vattr);
2995 		vattr.va_flags = flags;
2996 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
2997 		vput(vp);
2998 	}
2999 	return (error);
3000 }
3001 
3002 /*
3003  * chflags(char *path, int flags)
3004  *
3005  * Change flags of a file given a path name.
3006  */
3007 int
3008 sys_chflags(struct chflags_args *uap)
3009 {
3010 	struct nlookupdata nd;
3011 	struct vnode *vp;
3012 	int error;
3013 
3014 	vp = NULL;
3015 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3016 	if (error == 0)
3017 		error = nlookup(&nd);
3018 	if (error == 0)
3019 		error = ncp_writechk(&nd.nl_nch);
3020 	if (error == 0)
3021 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
3022 	nlookup_done(&nd);
3023 	if (error == 0) {
3024 		error = setfflags(vp, uap->flags);
3025 		vrele(vp);
3026 	}
3027 	return (error);
3028 }
3029 
3030 /*
3031  * lchflags(char *path, int flags)
3032  *
3033  * Change flags of a file given a path name, but don't follow symlinks.
3034  */
3035 int
3036 sys_lchflags(struct lchflags_args *uap)
3037 {
3038 	struct nlookupdata nd;
3039 	struct vnode *vp;
3040 	int error;
3041 
3042 	vp = NULL;
3043 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
3044 	if (error == 0)
3045 		error = nlookup(&nd);
3046 	if (error == 0)
3047 		error = ncp_writechk(&nd.nl_nch);
3048 	if (error == 0)
3049 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
3050 	nlookup_done(&nd);
3051 	if (error == 0) {
3052 		error = setfflags(vp, uap->flags);
3053 		vrele(vp);
3054 	}
3055 	return (error);
3056 }
3057 
3058 /*
3059  * fchflags_args(int fd, int flags)
3060  *
3061  * Change flags of a file given a file descriptor.
3062  */
3063 int
3064 sys_fchflags(struct fchflags_args *uap)
3065 {
3066 	struct thread *td = curthread;
3067 	struct proc *p = td->td_proc;
3068 	struct file *fp;
3069 	int error;
3070 
3071 	if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
3072 		return (error);
3073 	if (fp->f_nchandle.ncp)
3074 		error = ncp_writechk(&fp->f_nchandle);
3075 	if (error == 0)
3076 		error = setfflags((struct vnode *) fp->f_data, uap->flags);
3077 	fdrop(fp);
3078 	return (error);
3079 }
3080 
3081 /*
3082  * chflagsat_args(int fd, const char *path, int flags, int atflags)
3083  * change flags given a pathname relative to a filedescriptor
3084  */
3085 int sys_chflagsat(struct chflagsat_args *uap)
3086 {
3087 	struct nlookupdata nd;
3088 	struct vnode *vp;
3089 	struct file *fp;
3090 	int error;
3091 	int lookupflags;
3092 
3093 	if (uap->atflags & ~AT_SYMLINK_NOFOLLOW)
3094 		return (EINVAL);
3095 
3096 	lookupflags = (uap->atflags & AT_SYMLINK_NOFOLLOW) ? 0 : NLC_FOLLOW;
3097 
3098 	vp = NULL;
3099 	error = nlookup_init_at(&nd, &fp, uap->fd,  uap->path, UIO_USERSPACE, lookupflags);
3100 	if (error == 0)
3101 		error = nlookup(&nd);
3102 	if (error == 0)
3103 		error = ncp_writechk(&nd.nl_nch);
3104 	if (error == 0)
3105 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
3106 	nlookup_done_at(&nd, fp);
3107 	if (error == 0) {
3108 		error = setfflags(vp, uap->flags);
3109 		vrele(vp);
3110 	}
3111 	return (error);
3112 }
3113 
3114 
3115 static int
3116 setfmode(struct vnode *vp, int mode)
3117 {
3118 	struct thread *td = curthread;
3119 	int error;
3120 	struct vattr vattr;
3121 
3122 	/*
3123 	 * note: vget is required for any operation that might mod the vnode
3124 	 * so VINACTIVE is properly cleared.
3125 	 */
3126 	if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
3127 		VATTR_NULL(&vattr);
3128 		vattr.va_mode = mode & ALLPERMS;
3129 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
3130 		vput(vp);
3131 	}
3132 	return error;
3133 }
3134 
3135 int
3136 kern_chmod(struct nlookupdata *nd, int mode)
3137 {
3138 	struct vnode *vp;
3139 	int error;
3140 
3141 	if ((error = nlookup(nd)) != 0)
3142 		return (error);
3143 	if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
3144 		return (error);
3145 	if ((error = ncp_writechk(&nd->nl_nch)) == 0)
3146 		error = setfmode(vp, mode);
3147 	vrele(vp);
3148 	return (error);
3149 }
3150 
3151 /*
3152  * chmod_args(char *path, int mode)
3153  *
3154  * Change mode of a file given path name.
3155  */
3156 int
3157 sys_chmod(struct chmod_args *uap)
3158 {
3159 	struct nlookupdata nd;
3160 	int error;
3161 
3162 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3163 	if (error == 0)
3164 		error = kern_chmod(&nd, uap->mode);
3165 	nlookup_done(&nd);
3166 	return (error);
3167 }
3168 
3169 /*
3170  * lchmod_args(char *path, int mode)
3171  *
3172  * Change mode of a file given path name (don't follow links.)
3173  */
3174 int
3175 sys_lchmod(struct lchmod_args *uap)
3176 {
3177 	struct nlookupdata nd;
3178 	int error;
3179 
3180 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
3181 	if (error == 0)
3182 		error = kern_chmod(&nd, uap->mode);
3183 	nlookup_done(&nd);
3184 	return (error);
3185 }
3186 
3187 /*
3188  * fchmod_args(int fd, int mode)
3189  *
3190  * Change mode of a file given a file descriptor.
3191  */
3192 int
3193 sys_fchmod(struct fchmod_args *uap)
3194 {
3195 	struct thread *td = curthread;
3196 	struct proc *p = td->td_proc;
3197 	struct file *fp;
3198 	int error;
3199 
3200 	if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
3201 		return (error);
3202 	if (fp->f_nchandle.ncp)
3203 		error = ncp_writechk(&fp->f_nchandle);
3204 	if (error == 0)
3205 		error = setfmode((struct vnode *)fp->f_data, uap->mode);
3206 	fdrop(fp);
3207 	return (error);
3208 }
3209 
3210 /*
3211  * fchmodat_args(char *path, int mode)
3212  *
3213  * Change mode of a file pointed to by fd/path.
3214  */
3215 int
3216 sys_fchmodat(struct fchmodat_args *uap)
3217 {
3218 	struct nlookupdata nd;
3219 	struct file *fp;
3220 	int error;
3221 	int flags;
3222 
3223 	if (uap->flags & ~AT_SYMLINK_NOFOLLOW)
3224 		return (EINVAL);
3225 	flags = (uap->flags & AT_SYMLINK_NOFOLLOW) ? 0 : NLC_FOLLOW;
3226 
3227 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path,
3228 				UIO_USERSPACE, flags);
3229 	if (error == 0)
3230 		error = kern_chmod(&nd, uap->mode);
3231 	nlookup_done_at(&nd, fp);
3232 	return (error);
3233 }
3234 
3235 static int
3236 setfown(struct mount *mp, struct vnode *vp, uid_t uid, gid_t gid)
3237 {
3238 	struct thread *td = curthread;
3239 	int error;
3240 	struct vattr vattr;
3241 	uid_t o_uid;
3242 	gid_t o_gid;
3243 	uint64_t size;
3244 
3245 	/*
3246 	 * note: vget is required for any operation that might mod the vnode
3247 	 * so VINACTIVE is properly cleared.
3248 	 */
3249 	if ((error = vget(vp, LK_EXCLUSIVE)) == 0) {
3250 		if ((error = VOP_GETATTR(vp, &vattr)) != 0)
3251 			return error;
3252 		o_uid = vattr.va_uid;
3253 		o_gid = vattr.va_gid;
3254 		size = vattr.va_size;
3255 
3256 		VATTR_NULL(&vattr);
3257 		vattr.va_uid = uid;
3258 		vattr.va_gid = gid;
3259 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
3260 		vput(vp);
3261 	}
3262 
3263 	if (error == 0) {
3264 		if (uid == -1)
3265 			uid = o_uid;
3266 		if (gid == -1)
3267 			gid = o_gid;
3268 		VFS_ACCOUNT(mp, o_uid, o_gid, -size);
3269 		VFS_ACCOUNT(mp,   uid,   gid,  size);
3270 	}
3271 
3272 	return error;
3273 }
3274 
3275 int
3276 kern_chown(struct nlookupdata *nd, int uid, int gid)
3277 {
3278 	struct vnode *vp;
3279 	int error;
3280 
3281 	if ((error = nlookup(nd)) != 0)
3282 		return (error);
3283 	if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
3284 		return (error);
3285 	if ((error = ncp_writechk(&nd->nl_nch)) == 0)
3286 		error = setfown(nd->nl_nch.mount, vp, uid, gid);
3287 	vrele(vp);
3288 	return (error);
3289 }
3290 
3291 /*
3292  * chown(char *path, int uid, int gid)
3293  *
3294  * Set ownership given a path name.
3295  */
3296 int
3297 sys_chown(struct chown_args *uap)
3298 {
3299 	struct nlookupdata nd;
3300 	int error;
3301 
3302 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3303 	if (error == 0)
3304 		error = kern_chown(&nd, uap->uid, uap->gid);
3305 	nlookup_done(&nd);
3306 	return (error);
3307 }
3308 
3309 /*
3310  * lchown_args(char *path, int uid, int gid)
3311  *
3312  * Set ownership given a path name, do not cross symlinks.
3313  */
3314 int
3315 sys_lchown(struct lchown_args *uap)
3316 {
3317 	struct nlookupdata nd;
3318 	int error;
3319 
3320 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
3321 	if (error == 0)
3322 		error = kern_chown(&nd, uap->uid, uap->gid);
3323 	nlookup_done(&nd);
3324 	return (error);
3325 }
3326 
3327 /*
3328  * fchown_args(int fd, int uid, int gid)
3329  *
3330  * Set ownership given a file descriptor.
3331  */
3332 int
3333 sys_fchown(struct fchown_args *uap)
3334 {
3335 	struct thread *td = curthread;
3336 	struct proc *p = td->td_proc;
3337 	struct file *fp;
3338 	int error;
3339 
3340 	if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
3341 		return (error);
3342 	if (fp->f_nchandle.ncp)
3343 		error = ncp_writechk(&fp->f_nchandle);
3344 	if (error == 0)
3345 		error = setfown(p->p_fd->fd_ncdir.mount,
3346 			(struct vnode *)fp->f_data, uap->uid, uap->gid);
3347 	fdrop(fp);
3348 	return (error);
3349 }
3350 
3351 /*
3352  * fchownat(int fd, char *path, int uid, int gid, int flags)
3353  *
3354  * Set ownership of file pointed to by fd/path.
3355  */
3356 int
3357 sys_fchownat(struct fchownat_args *uap)
3358 {
3359 	struct nlookupdata nd;
3360 	struct file *fp;
3361 	int error;
3362 	int flags;
3363 
3364 	if (uap->flags & ~AT_SYMLINK_NOFOLLOW)
3365 		return (EINVAL);
3366 	flags = (uap->flags & AT_SYMLINK_NOFOLLOW) ? 0 : NLC_FOLLOW;
3367 
3368 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path,
3369 				UIO_USERSPACE, flags);
3370 	if (error == 0)
3371 		error = kern_chown(&nd, uap->uid, uap->gid);
3372 	nlookup_done_at(&nd, fp);
3373 	return (error);
3374 }
3375 
3376 
3377 static int
3378 getutimes(struct timeval *tvp, struct timespec *tsp)
3379 {
3380 	struct timeval tv[2];
3381 	int error;
3382 
3383 	if (tvp == NULL) {
3384 		microtime(&tv[0]);
3385 		TIMEVAL_TO_TIMESPEC(&tv[0], &tsp[0]);
3386 		tsp[1] = tsp[0];
3387 	} else {
3388 		if ((error = itimerfix(tvp)) != 0)
3389 			return (error);
3390 		TIMEVAL_TO_TIMESPEC(&tvp[0], &tsp[0]);
3391 		TIMEVAL_TO_TIMESPEC(&tvp[1], &tsp[1]);
3392 	}
3393 	return 0;
3394 }
3395 
3396 static int
3397 getutimens(const struct timespec *ts, struct timespec *newts, int *nullflag)
3398 {
3399 	struct timespec tsnow;
3400 	int error;
3401 
3402 	*nullflag = 0;
3403 	nanotime(&tsnow);
3404 	if (ts == NULL) {
3405 		newts[0] = tsnow;
3406 		newts[1] = tsnow;
3407 		*nullflag = 1;
3408 		return (0);
3409 	}
3410 
3411 	newts[0] = ts[0];
3412 	newts[1] = ts[1];
3413 	if (newts[0].tv_nsec == UTIME_OMIT && newts[1].tv_nsec == UTIME_OMIT)
3414 		return (0);
3415 	if (newts[0].tv_nsec == UTIME_NOW && newts[1].tv_nsec == UTIME_NOW)
3416 		*nullflag = 1;
3417 
3418 	if (newts[0].tv_nsec == UTIME_OMIT)
3419 		newts[0].tv_sec = VNOVAL;
3420 	else if (newts[0].tv_nsec == UTIME_NOW)
3421 		newts[0] = tsnow;
3422 	else if ((error = itimespecfix(&newts[0])) != 0)
3423 		return (error);
3424 
3425 	if (newts[1].tv_nsec == UTIME_OMIT)
3426 		newts[1].tv_sec = VNOVAL;
3427 	else if (newts[1].tv_nsec == UTIME_NOW)
3428 		newts[1] = tsnow;
3429 	else if ((error = itimespecfix(&newts[1])) != 0)
3430 		return (error);
3431 
3432 	return (0);
3433 }
3434 
3435 static int
3436 setutimes(struct vnode *vp, struct vattr *vattr,
3437 	  const struct timespec *ts, int nullflag)
3438 {
3439 	struct thread *td = curthread;
3440 	int error;
3441 
3442 	VATTR_NULL(vattr);
3443 	vattr->va_atime = ts[0];
3444 	vattr->va_mtime = ts[1];
3445 	if (nullflag)
3446 		vattr->va_vaflags |= VA_UTIMES_NULL;
3447 	error = VOP_SETATTR(vp, vattr, td->td_ucred);
3448 
3449 	return error;
3450 }
3451 
3452 int
3453 kern_utimes(struct nlookupdata *nd, struct timeval *tptr)
3454 {
3455 	struct timespec ts[2];
3456 	int error;
3457 
3458 	if (tptr) {
3459 		if ((error = getutimes(tptr, ts)) != 0)
3460 			return (error);
3461 	}
3462 	error = kern_utimensat(nd, tptr ? ts : NULL, 0);
3463 	return (error);
3464 }
3465 
3466 /*
3467  * utimes_args(char *path, struct timeval *tptr)
3468  *
3469  * Set the access and modification times of a file.
3470  */
3471 int
3472 sys_utimes(struct utimes_args *uap)
3473 {
3474 	struct timeval tv[2];
3475 	struct nlookupdata nd;
3476 	int error;
3477 
3478 	if (uap->tptr) {
3479  		error = copyin(uap->tptr, tv, sizeof(tv));
3480 		if (error)
3481 			return (error);
3482 	}
3483 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3484 	if (error == 0)
3485 		error = kern_utimes(&nd, uap->tptr ? tv : NULL);
3486 	nlookup_done(&nd);
3487 	return (error);
3488 }
3489 
3490 /*
3491  * lutimes_args(char *path, struct timeval *tptr)
3492  *
3493  * Set the access and modification times of a file.
3494  */
3495 int
3496 sys_lutimes(struct lutimes_args *uap)
3497 {
3498 	struct timeval tv[2];
3499 	struct nlookupdata nd;
3500 	int error;
3501 
3502 	if (uap->tptr) {
3503 		error = copyin(uap->tptr, tv, sizeof(tv));
3504 		if (error)
3505 			return (error);
3506 	}
3507 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
3508 	if (error == 0)
3509 		error = kern_utimes(&nd, uap->tptr ? tv : NULL);
3510 	nlookup_done(&nd);
3511 	return (error);
3512 }
3513 
3514 /*
3515  * Set utimes on a file descriptor.  The creds used to open the
3516  * file are used to determine whether the operation is allowed
3517  * or not.
3518  */
3519 int
3520 kern_futimens(int fd, struct timespec *ts)
3521 {
3522 	struct thread *td = curthread;
3523 	struct proc *p = td->td_proc;
3524 	struct timespec newts[2];
3525 	struct file *fp;
3526 	struct vnode *vp;
3527 	struct vattr vattr;
3528 	int nullflag;
3529 	int error;
3530 
3531 	error = getutimens(ts, newts, &nullflag);
3532 	if (error)
3533 		return (error);
3534 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
3535 		return (error);
3536 	if (fp->f_nchandle.ncp)
3537 		error = ncp_writechk(&fp->f_nchandle);
3538 	if (error == 0) {
3539 		vp = fp->f_data;
3540 		error = vget(vp, LK_EXCLUSIVE);
3541 		if (error == 0) {
3542 			error = VOP_GETATTR(vp, &vattr);
3543 			if (error == 0) {
3544 				error = naccess_va(&vattr, NLC_OWN | NLC_WRITE,
3545 						   fp->f_cred);
3546 			}
3547 			if (error == 0) {
3548 				error = setutimes(vp, &vattr, newts, nullflag);
3549 			}
3550 			vput(vp);
3551 		}
3552 	}
3553 	fdrop(fp);
3554 	return (error);
3555 }
3556 
3557 /*
3558  * futimens_args(int fd, struct timespec *ts)
3559  *
3560  * Set the access and modification times of a file.
3561  */
3562 int
3563 sys_futimens(struct futimens_args *uap)
3564 {
3565 	struct timespec ts[2];
3566 	int error;
3567 
3568 	if (uap->ts) {
3569 		error = copyin(uap->ts, ts, sizeof(ts));
3570 		if (error)
3571 			return (error);
3572 	}
3573 	error = kern_futimens(uap->fd, uap->ts ? ts : NULL);
3574 	return (error);
3575 }
3576 
3577 int
3578 kern_futimes(int fd, struct timeval *tptr)
3579 {
3580 	struct timespec ts[2];
3581 	int error;
3582 
3583 	if (tptr) {
3584 		if ((error = getutimes(tptr, ts)) != 0)
3585 			return (error);
3586 	}
3587 	error = kern_futimens(fd, tptr ? ts : NULL);
3588 	return (error);
3589 }
3590 
3591 /*
3592  * futimes_args(int fd, struct timeval *tptr)
3593  *
3594  * Set the access and modification times of a file.
3595  */
3596 int
3597 sys_futimes(struct futimes_args *uap)
3598 {
3599 	struct timeval tv[2];
3600 	int error;
3601 
3602 	if (uap->tptr) {
3603 		error = copyin(uap->tptr, tv, sizeof(tv));
3604 		if (error)
3605 			return (error);
3606 	}
3607 	error = kern_futimes(uap->fd, uap->tptr ? tv : NULL);
3608 	return (error);
3609 }
3610 
3611 int
3612 kern_utimensat(struct nlookupdata *nd, const struct timespec *ts, int flags)
3613 {
3614 	struct timespec newts[2];
3615 	struct vnode *vp;
3616 	struct vattr vattr;
3617 	int nullflag;
3618 	int error;
3619 
3620 	if (flags & ~AT_SYMLINK_NOFOLLOW)
3621 		return (EINVAL);
3622 
3623 	error = getutimens(ts, newts, &nullflag);
3624 	if (error)
3625 		return (error);
3626 
3627 	nd->nl_flags |= NLC_OWN | NLC_WRITE;
3628 	if ((error = nlookup(nd)) != 0)
3629 		return (error);
3630 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
3631 		return (error);
3632 	if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
3633 		return (error);
3634 	if ((error = vn_writechk(vp, &nd->nl_nch)) == 0) {
3635 		error = vget(vp, LK_EXCLUSIVE);
3636 		if (error == 0) {
3637 			error = setutimes(vp, &vattr, newts, nullflag);
3638 			vput(vp);
3639 		}
3640 	}
3641 	vrele(vp);
3642 	return (error);
3643 }
3644 
3645 /*
3646  * utimensat_args(int fd, const char *path, const struct timespec *ts, int flags);
3647  *
3648  * Set file access and modification times of a file.
3649  */
3650 int
3651 sys_utimensat(struct utimensat_args *uap)
3652 {
3653 	struct timespec ts[2];
3654 	struct nlookupdata nd;
3655 	struct file *fp;
3656 	int error;
3657 	int flags;
3658 
3659 	if (uap->ts) {
3660 		error = copyin(uap->ts, ts, sizeof(ts));
3661 		if (error)
3662 			return (error);
3663 	}
3664 
3665 	flags = (uap->flags & AT_SYMLINK_NOFOLLOW) ? 0 : NLC_FOLLOW;
3666 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path,
3667 	                        UIO_USERSPACE, flags);
3668 	if (error == 0)
3669 		error = kern_utimensat(&nd, uap->ts ? ts : NULL, uap->flags);
3670 	nlookup_done_at(&nd, fp);
3671 	return (error);
3672 }
3673 
3674 int
3675 kern_truncate(struct nlookupdata *nd, off_t length)
3676 {
3677 	struct vnode *vp;
3678 	struct vattr vattr;
3679 	int error;
3680 	uid_t uid = 0;
3681 	gid_t gid = 0;
3682 	uint64_t old_size = 0;
3683 
3684 	if (length < 0)
3685 		return(EINVAL);
3686 	nd->nl_flags |= NLC_WRITE | NLC_TRUNCATE;
3687 	if ((error = nlookup(nd)) != 0)
3688 		return (error);
3689 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
3690 		return (error);
3691 	if ((error = cache_vref(&nd->nl_nch, nd->nl_cred, &vp)) != 0)
3692 		return (error);
3693 	error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM);
3694 	if (error) {
3695 		vrele(vp);
3696 		return (error);
3697 	}
3698 	if (vp->v_type == VDIR) {
3699 		error = EISDIR;
3700 		goto done;
3701 	}
3702 	if (vfs_quota_enabled) {
3703 		error = VOP_GETATTR(vp, &vattr);
3704 		KASSERT(error == 0, ("kern_truncate(): VOP_GETATTR didn't return 0"));
3705 		uid = vattr.va_uid;
3706 		gid = vattr.va_gid;
3707 		old_size = vattr.va_size;
3708 	}
3709 
3710 	if ((error = vn_writechk(vp, &nd->nl_nch)) == 0) {
3711 		VATTR_NULL(&vattr);
3712 		vattr.va_size = length;
3713 		error = VOP_SETATTR(vp, &vattr, nd->nl_cred);
3714 		VFS_ACCOUNT(nd->nl_nch.mount, uid, gid, length - old_size);
3715 	}
3716 done:
3717 	vput(vp);
3718 	return (error);
3719 }
3720 
3721 /*
3722  * truncate(char *path, int pad, off_t length)
3723  *
3724  * Truncate a file given its path name.
3725  */
3726 int
3727 sys_truncate(struct truncate_args *uap)
3728 {
3729 	struct nlookupdata nd;
3730 	int error;
3731 
3732 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
3733 	if (error == 0)
3734 		error = kern_truncate(&nd, uap->length);
3735 	nlookup_done(&nd);
3736 	return error;
3737 }
3738 
3739 int
3740 kern_ftruncate(int fd, off_t length)
3741 {
3742 	struct thread *td = curthread;
3743 	struct proc *p = td->td_proc;
3744 	struct vattr vattr;
3745 	struct vnode *vp;
3746 	struct file *fp;
3747 	int error;
3748 	uid_t uid = 0;
3749 	gid_t gid = 0;
3750 	uint64_t old_size = 0;
3751 	struct mount *mp;
3752 
3753 	if (length < 0)
3754 		return(EINVAL);
3755 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
3756 		return (error);
3757 	if (fp->f_nchandle.ncp) {
3758 		error = ncp_writechk(&fp->f_nchandle);
3759 		if (error)
3760 			goto done;
3761 	}
3762 	if ((fp->f_flag & FWRITE) == 0) {
3763 		error = EINVAL;
3764 		goto done;
3765 	}
3766 	if (fp->f_flag & FAPPENDONLY) {	/* inode was set s/uapnd */
3767 		error = EINVAL;
3768 		goto done;
3769 	}
3770 	vp = (struct vnode *)fp->f_data;
3771 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3772 	if (vp->v_type == VDIR) {
3773 		error = EISDIR;
3774 		vn_unlock(vp);
3775 		goto done;
3776 	}
3777 
3778 	if (vfs_quota_enabled) {
3779 		error = VOP_GETATTR(vp, &vattr);
3780 		KASSERT(error == 0, ("kern_ftruncate(): VOP_GETATTR didn't return 0"));
3781 		uid = vattr.va_uid;
3782 		gid = vattr.va_gid;
3783 		old_size = vattr.va_size;
3784 	}
3785 
3786 	if ((error = vn_writechk(vp, NULL)) == 0) {
3787 		VATTR_NULL(&vattr);
3788 		vattr.va_size = length;
3789 		error = VOP_SETATTR(vp, &vattr, fp->f_cred);
3790 		mp = vq_vptomp(vp);
3791 		VFS_ACCOUNT(mp, uid, gid, length - old_size);
3792 	}
3793 	vn_unlock(vp);
3794 done:
3795 	fdrop(fp);
3796 	return (error);
3797 }
3798 
3799 /*
3800  * ftruncate_args(int fd, int pad, off_t length)
3801  *
3802  * Truncate a file given a file descriptor.
3803  */
3804 int
3805 sys_ftruncate(struct ftruncate_args *uap)
3806 {
3807 	int error;
3808 
3809 	error = kern_ftruncate(uap->fd, uap->length);
3810 
3811 	return (error);
3812 }
3813 
3814 /*
3815  * fsync(int fd)
3816  *
3817  * Sync an open file.
3818  */
3819 int
3820 sys_fsync(struct fsync_args *uap)
3821 {
3822 	struct thread *td = curthread;
3823 	struct proc *p = td->td_proc;
3824 	struct vnode *vp;
3825 	struct file *fp;
3826 	vm_object_t obj;
3827 	int error;
3828 
3829 	if ((error = holdvnode(p->p_fd, uap->fd, &fp)) != 0)
3830 		return (error);
3831 	vp = (struct vnode *)fp->f_data;
3832 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3833 	if ((obj = vp->v_object) != NULL) {
3834 		if (vp->v_mount == NULL ||
3835 		    (vp->v_mount->mnt_kern_flag & MNTK_NOMSYNC) == 0) {
3836 			vm_object_page_clean(obj, 0, 0, 0);
3837 		}
3838 	}
3839 	error = VOP_FSYNC(vp, MNT_WAIT, VOP_FSYNC_SYSCALL);
3840 	if (error == 0 && vp->v_mount)
3841 		error = buf_fsync(vp);
3842 	vn_unlock(vp);
3843 	fdrop(fp);
3844 
3845 	return (error);
3846 }
3847 
3848 int
3849 kern_rename(struct nlookupdata *fromnd, struct nlookupdata *tond)
3850 {
3851 	struct nchandle fnchd;
3852 	struct nchandle tnchd;
3853 	struct namecache *ncp;
3854 	struct vnode *fdvp;
3855 	struct vnode *tdvp;
3856 	struct mount *mp;
3857 	int error;
3858 	u_int fncp_gen;
3859 	u_int tncp_gen;
3860 
3861 	bwillinode(1);
3862 	fromnd->nl_flags |= NLC_REFDVP | NLC_RENAME_SRC;
3863 	if ((error = nlookup(fromnd)) != 0)
3864 		return (error);
3865 	if ((fnchd.ncp = fromnd->nl_nch.ncp->nc_parent) == NULL)
3866 		return (ENOENT);
3867 	fnchd.mount = fromnd->nl_nch.mount;
3868 	cache_hold(&fnchd);
3869 
3870 	/*
3871 	 * unlock the source nch so we can lookup the target nch without
3872 	 * deadlocking.  The target may or may not exist so we do not check
3873 	 * for a target vp like kern_mkdir() and other creation functions do.
3874 	 *
3875 	 * The source and target directories are ref'd and rechecked after
3876 	 * everything is relocked to determine if the source or target file
3877 	 * has been renamed.
3878 	 */
3879 	KKASSERT(fromnd->nl_flags & NLC_NCPISLOCKED);
3880 	fromnd->nl_flags &= ~NLC_NCPISLOCKED;
3881 
3882 	fncp_gen = fromnd->nl_nch.ncp->nc_generation;
3883 
3884 	cache_unlock(&fromnd->nl_nch);
3885 
3886 	tond->nl_flags |= NLC_RENAME_DST | NLC_REFDVP;
3887 	if ((error = nlookup(tond)) != 0) {
3888 		cache_drop(&fnchd);
3889 		return (error);
3890 	}
3891 	tncp_gen = tond->nl_nch.ncp->nc_generation;
3892 
3893 	if ((tnchd.ncp = tond->nl_nch.ncp->nc_parent) == NULL) {
3894 		cache_drop(&fnchd);
3895 		return (ENOENT);
3896 	}
3897 	tnchd.mount = tond->nl_nch.mount;
3898 	cache_hold(&tnchd);
3899 
3900 	/*
3901 	 * If the source and target are the same there is nothing to do
3902 	 */
3903 	if (fromnd->nl_nch.ncp == tond->nl_nch.ncp) {
3904 		cache_drop(&fnchd);
3905 		cache_drop(&tnchd);
3906 		return (0);
3907 	}
3908 
3909 	/*
3910 	 * Mount points cannot be renamed or overwritten
3911 	 */
3912 	if ((fromnd->nl_nch.ncp->nc_flag | tond->nl_nch.ncp->nc_flag) &
3913 	    NCF_ISMOUNTPT
3914 	) {
3915 		cache_drop(&fnchd);
3916 		cache_drop(&tnchd);
3917 		return (EINVAL);
3918 	}
3919 
3920 	/*
3921 	 * Relock the source ncp.  cache_relock() will deal with any
3922 	 * deadlocks against the already-locked tond and will also
3923 	 * make sure both are resolved.
3924 	 *
3925 	 * NOTE AFTER RELOCKING: The source or target ncp may have become
3926 	 * invalid while they were unlocked, nc_vp and nc_mount could
3927 	 * be NULL.
3928 	 */
3929 	cache_relock(&fromnd->nl_nch, fromnd->nl_cred,
3930 		     &tond->nl_nch, tond->nl_cred);
3931 	fromnd->nl_flags |= NLC_NCPISLOCKED;
3932 
3933 	/*
3934 	 * If the namecache generation changed for either fromnd or tond,
3935 	 * we must retry.
3936 	 */
3937 	if (fromnd->nl_nch.ncp->nc_generation != fncp_gen ||
3938 	    tond->nl_nch.ncp->nc_generation != tncp_gen) {
3939 		kprintf("kern_rename: retry due to gen on: "
3940 			"\"%s\" -> \"%s\"\n",
3941 			fromnd->nl_nch.ncp->nc_name,
3942 			tond->nl_nch.ncp->nc_name);
3943 		cache_drop(&fnchd);
3944 		cache_drop(&tnchd);
3945 		return (EAGAIN);
3946 	}
3947 
3948 	/*
3949 	 * If either fromnd or tond are marked destroyed a ripout occured
3950 	 * out from under us and we must retry.
3951 	 */
3952 	if ((fromnd->nl_nch.ncp->nc_flag & (NCF_DESTROYED | NCF_UNRESOLVED)) ||
3953 	    fromnd->nl_nch.ncp->nc_vp == NULL ||
3954 	    (tond->nl_nch.ncp->nc_flag & NCF_DESTROYED)) {
3955 		kprintf("kern_rename: retry due to ripout on: "
3956 			"\"%s\" -> \"%s\"\n",
3957 			fromnd->nl_nch.ncp->nc_name,
3958 			tond->nl_nch.ncp->nc_name);
3959 		cache_drop(&fnchd);
3960 		cache_drop(&tnchd);
3961 		return (EAGAIN);
3962 	}
3963 
3964 	/*
3965 	 * Make sure the parent directories linkages are the same.
3966 	 * XXX shouldn't be needed any more w/ generation check above.
3967 	 */
3968 	if (fnchd.ncp != fromnd->nl_nch.ncp->nc_parent ||
3969 	    tnchd.ncp != tond->nl_nch.ncp->nc_parent) {
3970 		cache_drop(&fnchd);
3971 		cache_drop(&tnchd);
3972 		return (ENOENT);
3973 	}
3974 
3975 	/*
3976 	 * Both the source and target must be within the same filesystem and
3977 	 * in the same filesystem as their parent directories within the
3978 	 * namecache topology.
3979 	 *
3980 	 * NOTE: fromnd's nc_mount or nc_vp could be NULL.
3981 	 */
3982 	mp = fnchd.mount;
3983 	if (mp != tnchd.mount || mp != fromnd->nl_nch.mount ||
3984 	    mp != tond->nl_nch.mount) {
3985 		cache_drop(&fnchd);
3986 		cache_drop(&tnchd);
3987 		return (EXDEV);
3988 	}
3989 
3990 	/*
3991 	 * Make sure the mount point is writable
3992 	 */
3993 	if ((error = ncp_writechk(&tond->nl_nch)) != 0) {
3994 		cache_drop(&fnchd);
3995 		cache_drop(&tnchd);
3996 		return (error);
3997 	}
3998 
3999 	/*
4000 	 * If the target exists and either the source or target is a directory,
4001 	 * then both must be directories.
4002 	 *
4003 	 * Due to relocking of the source, fromnd->nl_nch.ncp->nc_vp might h
4004 	 * have become NULL.
4005 	 */
4006 	if (tond->nl_nch.ncp->nc_vp) {
4007 		if (fromnd->nl_nch.ncp->nc_vp == NULL) {
4008 			error = ENOENT;
4009 		} else if (fromnd->nl_nch.ncp->nc_vp->v_type == VDIR) {
4010 			if (tond->nl_nch.ncp->nc_vp->v_type != VDIR)
4011 				error = ENOTDIR;
4012 		} else if (tond->nl_nch.ncp->nc_vp->v_type == VDIR) {
4013 			error = EISDIR;
4014 		}
4015 	}
4016 
4017 	/*
4018 	 * You cannot rename a source into itself or a subdirectory of itself.
4019 	 * We check this by travsersing the target directory upwards looking
4020 	 * for a match against the source.
4021 	 *
4022 	 * XXX MPSAFE
4023 	 */
4024 	if (error == 0) {
4025 		for (ncp = tnchd.ncp; ncp; ncp = ncp->nc_parent) {
4026 			if (fromnd->nl_nch.ncp == ncp) {
4027 				error = EINVAL;
4028 				break;
4029 			}
4030 		}
4031 	}
4032 
4033 	cache_drop(&fnchd);
4034 	cache_drop(&tnchd);
4035 
4036 	/*
4037 	 * Even though the namespaces are different, they may still represent
4038 	 * hardlinks to the same file.  The filesystem might have a hard time
4039 	 * with this so we issue a NREMOVE of the source instead of a NRENAME
4040 	 * when we detect the situation.
4041 	 */
4042 	if (error == 0) {
4043 		fdvp = fromnd->nl_dvp;
4044 		tdvp = tond->nl_dvp;
4045 		if (fdvp == NULL || tdvp == NULL) {
4046 			error = EPERM;
4047 		} else if (fromnd->nl_nch.ncp->nc_vp == tond->nl_nch.ncp->nc_vp) {
4048 			error = VOP_NREMOVE(&fromnd->nl_nch, fdvp,
4049 					    fromnd->nl_cred);
4050 		} else {
4051 			error = VOP_NRENAME(&fromnd->nl_nch, &tond->nl_nch,
4052 					    fdvp, tdvp, tond->nl_cred);
4053 		}
4054 	}
4055 	return (error);
4056 }
4057 
4058 /*
4059  * rename_args(char *from, char *to)
4060  *
4061  * Rename files.  Source and destination must either both be directories,
4062  * or both not be directories.  If target is a directory, it must be empty.
4063  */
4064 int
4065 sys_rename(struct rename_args *uap)
4066 {
4067 	struct nlookupdata fromnd, tond;
4068 	int error;
4069 
4070 	do {
4071 		error = nlookup_init(&fromnd, uap->from, UIO_USERSPACE, 0);
4072 		if (error == 0) {
4073 			error = nlookup_init(&tond, uap->to, UIO_USERSPACE, 0);
4074 			if (error == 0)
4075 				error = kern_rename(&fromnd, &tond);
4076 			nlookup_done(&tond);
4077 		}
4078 		nlookup_done(&fromnd);
4079 	} while (error == EAGAIN);
4080 	return (error);
4081 }
4082 
4083 /*
4084  * renameat_args(int oldfd, char *old, int newfd, char *new)
4085  *
4086  * Rename files using paths relative to the directories associated with
4087  * oldfd and newfd.  Source and destination must either both be directories,
4088  * or both not be directories.  If target is a directory, it must be empty.
4089  */
4090 int
4091 sys_renameat(struct renameat_args *uap)
4092 {
4093 	struct nlookupdata oldnd, newnd;
4094 	struct file *oldfp, *newfp;
4095 	int error;
4096 
4097 	do {
4098 		error = nlookup_init_at(&oldnd, &oldfp,
4099 					uap->oldfd, uap->old,
4100 					UIO_USERSPACE, 0);
4101 		if (error == 0) {
4102 			error = nlookup_init_at(&newnd, &newfp,
4103 						uap->newfd, uap->new,
4104 						UIO_USERSPACE, 0);
4105 			if (error == 0)
4106 				error = kern_rename(&oldnd, &newnd);
4107 			nlookup_done_at(&newnd, newfp);
4108 		}
4109 		nlookup_done_at(&oldnd, oldfp);
4110 	} while (error == EAGAIN);
4111 	return (error);
4112 }
4113 
4114 int
4115 kern_mkdir(struct nlookupdata *nd, int mode)
4116 {
4117 	struct thread *td = curthread;
4118 	struct proc *p = td->td_proc;
4119 	struct vnode *vp;
4120 	struct vattr vattr;
4121 	int error;
4122 
4123 	bwillinode(1);
4124 	nd->nl_flags |= NLC_WILLBEDIR | NLC_CREATE | NLC_REFDVP;
4125 	if ((error = nlookup(nd)) != 0)
4126 		return (error);
4127 
4128 	if (nd->nl_nch.ncp->nc_vp)
4129 		return (EEXIST);
4130 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
4131 		return (error);
4132 	VATTR_NULL(&vattr);
4133 	vattr.va_type = VDIR;
4134 	vattr.va_mode = (mode & ACCESSPERMS) &~ p->p_fd->fd_cmask;
4135 
4136 	vp = NULL;
4137 	error = VOP_NMKDIR(&nd->nl_nch, nd->nl_dvp, &vp, td->td_ucred, &vattr);
4138 	if (error == 0)
4139 		vput(vp);
4140 	return (error);
4141 }
4142 
4143 /*
4144  * mkdir_args(char *path, int mode)
4145  *
4146  * Make a directory file.
4147  */
4148 int
4149 sys_mkdir(struct mkdir_args *uap)
4150 {
4151 	struct nlookupdata nd;
4152 	int error;
4153 
4154 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
4155 	if (error == 0)
4156 		error = kern_mkdir(&nd, uap->mode);
4157 	nlookup_done(&nd);
4158 	return (error);
4159 }
4160 
4161 /*
4162  * mkdirat_args(int fd, char *path, mode_t mode)
4163  *
4164  * Make a directory file.  The path is relative to the directory associated
4165  * with fd.
4166  */
4167 int
4168 sys_mkdirat(struct mkdirat_args *uap)
4169 {
4170 	struct nlookupdata nd;
4171 	struct file *fp;
4172 	int error;
4173 
4174 	error = nlookup_init_at(&nd, &fp, uap->fd, uap->path, UIO_USERSPACE, 0);
4175 	if (error == 0)
4176 		error = kern_mkdir(&nd, uap->mode);
4177 	nlookup_done_at(&nd, fp);
4178 	return (error);
4179 }
4180 
4181 int
4182 kern_rmdir(struct nlookupdata *nd)
4183 {
4184 	int error;
4185 
4186 	bwillinode(1);
4187 	nd->nl_flags |= NLC_DELETE | NLC_REFDVP;
4188 	if ((error = nlookup(nd)) != 0)
4189 		return (error);
4190 
4191 	/*
4192 	 * Do not allow directories representing mount points to be
4193 	 * deleted, even if empty.  Check write perms on mount point
4194 	 * in case the vnode is aliased (aka nullfs).
4195 	 */
4196 	if (nd->nl_nch.ncp->nc_flag & (NCF_ISMOUNTPT))
4197 		return (EBUSY);
4198 	if ((error = ncp_writechk(&nd->nl_nch)) != 0)
4199 		return (error);
4200 	error = VOP_NRMDIR(&nd->nl_nch, nd->nl_dvp, nd->nl_cred);
4201 	return (error);
4202 }
4203 
4204 /*
4205  * rmdir_args(char *path)
4206  *
4207  * Remove a directory file.
4208  */
4209 int
4210 sys_rmdir(struct rmdir_args *uap)
4211 {
4212 	struct nlookupdata nd;
4213 	int error;
4214 
4215 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, 0);
4216 	if (error == 0)
4217 		error = kern_rmdir(&nd);
4218 	nlookup_done(&nd);
4219 	return (error);
4220 }
4221 
4222 int
4223 kern_getdirentries(int fd, char *buf, u_int count, long *basep, int *res,
4224 		   enum uio_seg direction)
4225 {
4226 	struct thread *td = curthread;
4227 	struct proc *p = td->td_proc;
4228 	struct vnode *vp;
4229 	struct file *fp;
4230 	struct uio auio;
4231 	struct iovec aiov;
4232 	off_t loff;
4233 	int error, eofflag;
4234 
4235 	if ((error = holdvnode(p->p_fd, fd, &fp)) != 0)
4236 		return (error);
4237 	if ((fp->f_flag & FREAD) == 0) {
4238 		error = EBADF;
4239 		goto done;
4240 	}
4241 	vp = (struct vnode *)fp->f_data;
4242 	if (vp->v_type != VDIR) {
4243 		error = EINVAL;
4244 		goto done;
4245 	}
4246 	aiov.iov_base = buf;
4247 	aiov.iov_len = count;
4248 	auio.uio_iov = &aiov;
4249 	auio.uio_iovcnt = 1;
4250 	auio.uio_rw = UIO_READ;
4251 	auio.uio_segflg = direction;
4252 	auio.uio_td = td;
4253 	auio.uio_resid = count;
4254 	loff = auio.uio_offset = fp->f_offset;
4255 	error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL, NULL);
4256 	fp->f_offset = auio.uio_offset;
4257 	if (error)
4258 		goto done;
4259 
4260 	/*
4261 	 * WARNING!  *basep may not be wide enough to accomodate the
4262 	 * seek offset.   XXX should we hack this to return the upper 32 bits
4263 	 * for offsets greater then 4G?
4264 	 */
4265 	if (basep) {
4266 		*basep = (long)loff;
4267 	}
4268 	*res = count - auio.uio_resid;
4269 done:
4270 	fdrop(fp);
4271 	return (error);
4272 }
4273 
4274 /*
4275  * getdirentries_args(int fd, char *buf, u_int conut, long *basep)
4276  *
4277  * Read a block of directory entries in a file system independent format.
4278  */
4279 int
4280 sys_getdirentries(struct getdirentries_args *uap)
4281 {
4282 	long base;
4283 	int error;
4284 
4285 	error = kern_getdirentries(uap->fd, uap->buf, uap->count, &base,
4286 				   &uap->sysmsg_result, UIO_USERSPACE);
4287 
4288 	if (error == 0 && uap->basep)
4289 		error = copyout(&base, uap->basep, sizeof(*uap->basep));
4290 	return (error);
4291 }
4292 
4293 /*
4294  * getdents_args(int fd, char *buf, size_t count)
4295  */
4296 int
4297 sys_getdents(struct getdents_args *uap)
4298 {
4299 	int error;
4300 
4301 	error = kern_getdirentries(uap->fd, uap->buf, uap->count, NULL,
4302 				   &uap->sysmsg_result, UIO_USERSPACE);
4303 
4304 	return (error);
4305 }
4306 
4307 /*
4308  * Set the mode mask for creation of filesystem nodes.
4309  *
4310  * umask(int newmask)
4311  */
4312 int
4313 sys_umask(struct umask_args *uap)
4314 {
4315 	struct thread *td = curthread;
4316 	struct proc *p = td->td_proc;
4317 	struct filedesc *fdp;
4318 
4319 	fdp = p->p_fd;
4320 	uap->sysmsg_result = fdp->fd_cmask;
4321 	fdp->fd_cmask = uap->newmask & ALLPERMS;
4322 	return (0);
4323 }
4324 
4325 /*
4326  * revoke(char *path)
4327  *
4328  * Void all references to file by ripping underlying filesystem
4329  * away from vnode.
4330  */
4331 int
4332 sys_revoke(struct revoke_args *uap)
4333 {
4334 	struct nlookupdata nd;
4335 	struct vattr vattr;
4336 	struct vnode *vp;
4337 	struct ucred *cred;
4338 	int error;
4339 
4340 	vp = NULL;
4341 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4342 	if (error == 0)
4343 		error = nlookup(&nd);
4344 	if (error == 0)
4345 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
4346 	cred = crhold(nd.nl_cred);
4347 	nlookup_done(&nd);
4348 	if (error == 0) {
4349 		if (error == 0)
4350 			error = VOP_GETATTR(vp, &vattr);
4351 		if (error == 0 && cred->cr_uid != vattr.va_uid)
4352 			error = priv_check_cred(cred, PRIV_VFS_REVOKE, 0);
4353 		if (error == 0 && (vp->v_type == VCHR || vp->v_type == VBLK)) {
4354 			if (vcount(vp) > 0)
4355 				error = vrevoke(vp, cred);
4356 		} else if (error == 0) {
4357 			error = vrevoke(vp, cred);
4358 		}
4359 		vrele(vp);
4360 	}
4361 	if (cred)
4362 		crfree(cred);
4363 	return (error);
4364 }
4365 
4366 /*
4367  * getfh_args(char *fname, fhandle_t *fhp)
4368  *
4369  * Get (NFS) file handle
4370  *
4371  * NOTE: We use the fsid of the covering mount, even if it is a nullfs
4372  * mount.  This allows nullfs mounts to be explicitly exported.
4373  *
4374  * WARNING: nullfs mounts of HAMMER PFS ROOTs are safe.
4375  *
4376  * 	    nullfs mounts of subdirectories are not safe.  That is, it will
4377  *	    work, but you do not really have protection against access to
4378  *	    the related parent directories.
4379  */
4380 int
4381 sys_getfh(struct getfh_args *uap)
4382 {
4383 	struct thread *td = curthread;
4384 	struct nlookupdata nd;
4385 	fhandle_t fh;
4386 	struct vnode *vp;
4387 	struct mount *mp;
4388 	int error;
4389 
4390 	/*
4391 	 * Must be super user
4392 	 */
4393 	if ((error = priv_check(td, PRIV_ROOT)) != 0)
4394 		return (error);
4395 
4396 	vp = NULL;
4397 	error = nlookup_init(&nd, uap->fname, UIO_USERSPACE, NLC_FOLLOW);
4398 	if (error == 0)
4399 		error = nlookup(&nd);
4400 	if (error == 0)
4401 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
4402 	mp = nd.nl_nch.mount;
4403 	nlookup_done(&nd);
4404 	if (error == 0) {
4405 		bzero(&fh, sizeof(fh));
4406 		fh.fh_fsid = mp->mnt_stat.f_fsid;
4407 		error = VFS_VPTOFH(vp, &fh.fh_fid);
4408 		vput(vp);
4409 		if (error == 0)
4410 			error = copyout(&fh, uap->fhp, sizeof(fh));
4411 	}
4412 	return (error);
4413 }
4414 
4415 /*
4416  * fhopen_args(const struct fhandle *u_fhp, int flags)
4417  *
4418  * syscall for the rpc.lockd to use to translate a NFS file handle into
4419  * an open descriptor.
4420  *
4421  * warning: do not remove the priv_check() call or this becomes one giant
4422  * security hole.
4423  */
4424 int
4425 sys_fhopen(struct fhopen_args *uap)
4426 {
4427 	struct thread *td = curthread;
4428 	struct filedesc *fdp = td->td_proc->p_fd;
4429 	struct mount *mp;
4430 	struct vnode *vp;
4431 	struct fhandle fhp;
4432 	struct vattr vat;
4433 	struct vattr *vap = &vat;
4434 	struct flock lf;
4435 	int fmode, mode, error = 0, type;
4436 	struct file *nfp;
4437 	struct file *fp;
4438 	int indx;
4439 
4440 	/*
4441 	 * Must be super user
4442 	 */
4443 	error = priv_check(td, PRIV_ROOT);
4444 	if (error)
4445 		return (error);
4446 
4447 	fmode = FFLAGS(uap->flags);
4448 
4449 	/*
4450 	 * Why not allow a non-read/write open for our lockd?
4451 	 */
4452 	if (((fmode & (FREAD | FWRITE)) == 0) || (fmode & O_CREAT))
4453 		return (EINVAL);
4454 	error = copyin(uap->u_fhp, &fhp, sizeof(fhp));
4455 	if (error)
4456 		return(error);
4457 
4458 	/*
4459 	 * Find the mount point
4460 	 */
4461 	mp = vfs_getvfs(&fhp.fh_fsid);
4462 	if (mp == NULL) {
4463 		error = ESTALE;
4464 		goto  done;
4465 	}
4466 	/* now give me my vnode, it gets returned to me locked */
4467 	error = VFS_FHTOVP(mp, NULL, &fhp.fh_fid, &vp);
4468 	if (error)
4469 		goto done;
4470  	/*
4471 	 * from now on we have to make sure not
4472 	 * to forget about the vnode
4473 	 * any error that causes an abort must vput(vp)
4474 	 * just set error = err and 'goto bad;'.
4475 	 */
4476 
4477 	/*
4478 	 * from vn_open
4479 	 */
4480 	if (vp->v_type == VLNK) {
4481 		error = EMLINK;
4482 		goto bad;
4483 	}
4484 	if (vp->v_type == VSOCK) {
4485 		error = EOPNOTSUPP;
4486 		goto bad;
4487 	}
4488 	mode = 0;
4489 	if (fmode & (FWRITE | O_TRUNC)) {
4490 		if (vp->v_type == VDIR) {
4491 			error = EISDIR;
4492 			goto bad;
4493 		}
4494 		error = vn_writechk(vp, NULL);
4495 		if (error)
4496 			goto bad;
4497 		mode |= VWRITE;
4498 	}
4499 	if (fmode & FREAD)
4500 		mode |= VREAD;
4501 	if (mode) {
4502 		error = VOP_ACCESS(vp, mode, td->td_ucred);
4503 		if (error)
4504 			goto bad;
4505 	}
4506 	if (fmode & O_TRUNC) {
4507 		vn_unlock(vp);				/* XXX */
4508 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);	/* XXX */
4509 		VATTR_NULL(vap);
4510 		vap->va_size = 0;
4511 		error = VOP_SETATTR(vp, vap, td->td_ucred);
4512 		if (error)
4513 			goto bad;
4514 	}
4515 
4516 	/*
4517 	 * VOP_OPEN needs the file pointer so it can potentially override
4518 	 * it.
4519 	 *
4520 	 * WARNING! no f_nchandle will be associated when fhopen()ing a
4521 	 * directory.  XXX
4522 	 */
4523 	if ((error = falloc(td->td_lwp, &nfp, &indx)) != 0)
4524 		goto bad;
4525 	fp = nfp;
4526 
4527 	error = VOP_OPEN(vp, fmode, td->td_ucred, fp);
4528 	if (error) {
4529 		/*
4530 		 * setting f_ops this way prevents VOP_CLOSE from being
4531 		 * called or fdrop() releasing the vp from v_data.   Since
4532 		 * the VOP_OPEN failed we don't want to VOP_CLOSE.
4533 		 */
4534 		fp->f_ops = &badfileops;
4535 		fp->f_data = NULL;
4536 		goto bad_drop;
4537 	}
4538 
4539 	/*
4540 	 * The fp is given its own reference, we still have our ref and lock.
4541 	 *
4542 	 * Assert that all regular files must be created with a VM object.
4543 	 */
4544 	if (vp->v_type == VREG && vp->v_object == NULL) {
4545 		kprintf("fhopen: regular file did not have VM object: %p\n", vp);
4546 		goto bad_drop;
4547 	}
4548 
4549 	/*
4550 	 * The open was successful.  Handle any locking requirements.
4551 	 */
4552 	if (fmode & (O_EXLOCK | O_SHLOCK)) {
4553 		lf.l_whence = SEEK_SET;
4554 		lf.l_start = 0;
4555 		lf.l_len = 0;
4556 		if (fmode & O_EXLOCK)
4557 			lf.l_type = F_WRLCK;
4558 		else
4559 			lf.l_type = F_RDLCK;
4560 		if (fmode & FNONBLOCK)
4561 			type = 0;
4562 		else
4563 			type = F_WAIT;
4564 		vn_unlock(vp);
4565 		if ((error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf, type)) != 0) {
4566 			/*
4567 			 * release our private reference.
4568 			 */
4569 			fsetfd(fdp, NULL, indx);
4570 			fdrop(fp);
4571 			vrele(vp);
4572 			goto done;
4573 		}
4574 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
4575 		atomic_set_int(&fp->f_flag, FHASLOCK);	/* race ok */
4576 	}
4577 
4578 	/*
4579 	 * Clean up.  Associate the file pointer with the previously
4580 	 * reserved descriptor and return it.
4581 	 */
4582 	vput(vp);
4583 	if (uap->flags & O_CLOEXEC)
4584 		fdp->fd_files[indx].fileflags |= UF_EXCLOSE;
4585 	fsetfd(fdp, fp, indx);
4586 	fdrop(fp);
4587 	uap->sysmsg_result = indx;
4588 	return (error);
4589 
4590 bad_drop:
4591 	fsetfd(fdp, NULL, indx);
4592 	fdrop(fp);
4593 bad:
4594 	vput(vp);
4595 done:
4596 	return (error);
4597 }
4598 
4599 /*
4600  * fhstat_args(struct fhandle *u_fhp, struct stat *sb)
4601  */
4602 int
4603 sys_fhstat(struct fhstat_args *uap)
4604 {
4605 	struct thread *td = curthread;
4606 	struct stat sb;
4607 	fhandle_t fh;
4608 	struct mount *mp;
4609 	struct vnode *vp;
4610 	int error;
4611 
4612 	/*
4613 	 * Must be super user
4614 	 */
4615 	error = priv_check(td, PRIV_ROOT);
4616 	if (error)
4617 		return (error);
4618 
4619 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
4620 	if (error)
4621 		return (error);
4622 
4623 	if ((mp = vfs_getvfs(&fh.fh_fsid)) == NULL)
4624 		error = ESTALE;
4625 	if (error == 0) {
4626 		if ((error = VFS_FHTOVP(mp, NULL, &fh.fh_fid, &vp)) == 0) {
4627 			error = vn_stat(vp, &sb, td->td_ucred);
4628 			vput(vp);
4629 		}
4630 	}
4631 	if (error == 0)
4632 		error = copyout(&sb, uap->sb, sizeof(sb));
4633 	return (error);
4634 }
4635 
4636 /*
4637  * fhstatfs_args(struct fhandle *u_fhp, struct statfs *buf)
4638  */
4639 int
4640 sys_fhstatfs(struct fhstatfs_args *uap)
4641 {
4642 	struct thread *td = curthread;
4643 	struct proc *p = td->td_proc;
4644 	struct statfs *sp;
4645 	struct mount *mp;
4646 	struct vnode *vp;
4647 	struct statfs sb;
4648 	char *fullpath, *freepath;
4649 	fhandle_t fh;
4650 	int error;
4651 
4652 	/*
4653 	 * Must be super user
4654 	 */
4655 	if ((error = priv_check(td, PRIV_ROOT)))
4656 		return (error);
4657 
4658 	if ((error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t))) != 0)
4659 		return (error);
4660 
4661 	if ((mp = vfs_getvfs(&fh.fh_fsid)) == NULL) {
4662 		error = ESTALE;
4663 		goto done;
4664 	}
4665 	if (p != NULL && !chroot_visible_mnt(mp, p)) {
4666 		error = ESTALE;
4667 		goto done;
4668 	}
4669 
4670 	if ((error = VFS_FHTOVP(mp, NULL, &fh.fh_fid, &vp)) != 0)
4671 		goto done;
4672 	mp = vp->v_mount;
4673 	sp = &mp->mnt_stat;
4674 	vput(vp);
4675 	if ((error = VFS_STATFS(mp, sp, td->td_ucred)) != 0)
4676 		goto done;
4677 
4678 	error = mount_path(p, mp, &fullpath, &freepath);
4679 	if (error)
4680 		goto done;
4681 	bzero(sp->f_mntonname, sizeof(sp->f_mntonname));
4682 	strlcpy(sp->f_mntonname, fullpath, sizeof(sp->f_mntonname));
4683 	kfree(freepath, M_TEMP);
4684 
4685 	sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
4686 	if (priv_check(td, PRIV_ROOT)) {
4687 		bcopy(sp, &sb, sizeof(sb));
4688 		sb.f_fsid.val[0] = sb.f_fsid.val[1] = 0;
4689 		sp = &sb;
4690 	}
4691 	error = copyout(sp, uap->buf, sizeof(*sp));
4692 done:
4693 	return (error);
4694 }
4695 
4696 /*
4697  * fhstatvfs_args(struct fhandle *u_fhp, struct statvfs *buf)
4698  */
4699 int
4700 sys_fhstatvfs(struct fhstatvfs_args *uap)
4701 {
4702 	struct thread *td = curthread;
4703 	struct proc *p = td->td_proc;
4704 	struct statvfs *sp;
4705 	struct mount *mp;
4706 	struct vnode *vp;
4707 	fhandle_t fh;
4708 	int error;
4709 
4710 	/*
4711 	 * Must be super user
4712 	 */
4713 	if ((error = priv_check(td, PRIV_ROOT)))
4714 		return (error);
4715 
4716 	if ((error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t))) != 0)
4717 		return (error);
4718 
4719 	if ((mp = vfs_getvfs(&fh.fh_fsid)) == NULL) {
4720 		error = ESTALE;
4721 		goto done;
4722 	}
4723 	if (p != NULL && !chroot_visible_mnt(mp, p)) {
4724 		error = ESTALE;
4725 		goto done;
4726 	}
4727 
4728 	if ((error = VFS_FHTOVP(mp, NULL, &fh.fh_fid, &vp)))
4729 		goto done;
4730 	mp = vp->v_mount;
4731 	sp = &mp->mnt_vstat;
4732 	vput(vp);
4733 	if ((error = VFS_STATVFS(mp, sp, td->td_ucred)) != 0)
4734 		goto done;
4735 
4736 	sp->f_flag = 0;
4737 	if (mp->mnt_flag & MNT_RDONLY)
4738 		sp->f_flag |= ST_RDONLY;
4739 	if (mp->mnt_flag & MNT_NOSUID)
4740 		sp->f_flag |= ST_NOSUID;
4741 	error = copyout(sp, uap->buf, sizeof(*sp));
4742 done:
4743 	return (error);
4744 }
4745 
4746 
4747 /*
4748  * Syscall to push extended attribute configuration information into the
4749  * VFS.  Accepts a path, which it converts to a mountpoint, as well as
4750  * a command (int cmd), and attribute name and misc data.  For now, the
4751  * attribute name is left in userspace for consumption by the VFS_op.
4752  * It will probably be changed to be copied into sysspace by the
4753  * syscall in the future, once issues with various consumers of the
4754  * attribute code have raised their hands.
4755  *
4756  * Currently this is used only by UFS Extended Attributes.
4757  */
4758 int
4759 sys_extattrctl(struct extattrctl_args *uap)
4760 {
4761 	struct nlookupdata nd;
4762 	struct vnode *vp;
4763 	char attrname[EXTATTR_MAXNAMELEN];
4764 	int error;
4765 	size_t size;
4766 
4767 	attrname[0] = 0;
4768 	vp = NULL;
4769 	error = 0;
4770 
4771 	if (error == 0 && uap->filename) {
4772 		error = nlookup_init(&nd, uap->filename, UIO_USERSPACE,
4773 				     NLC_FOLLOW);
4774 		if (error == 0)
4775 			error = nlookup(&nd);
4776 		if (error == 0)
4777 			error = cache_vref(&nd.nl_nch, nd.nl_cred, &vp);
4778 		nlookup_done(&nd);
4779 	}
4780 
4781 	if (error == 0 && uap->attrname) {
4782 		error = copyinstr(uap->attrname, attrname, EXTATTR_MAXNAMELEN,
4783 				  &size);
4784 	}
4785 
4786 	if (error == 0) {
4787 		error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4788 		if (error == 0)
4789 			error = nlookup(&nd);
4790 		if (error == 0)
4791 			error = ncp_writechk(&nd.nl_nch);
4792 		if (error == 0) {
4793 			error = VFS_EXTATTRCTL(nd.nl_nch.mount, uap->cmd, vp,
4794 					       uap->attrnamespace,
4795 					       uap->attrname, nd.nl_cred);
4796 		}
4797 		nlookup_done(&nd);
4798 	}
4799 
4800 	return (error);
4801 }
4802 
4803 /*
4804  * Syscall to get a named extended attribute on a file or directory.
4805  */
4806 int
4807 sys_extattr_set_file(struct extattr_set_file_args *uap)
4808 {
4809 	char attrname[EXTATTR_MAXNAMELEN];
4810 	struct nlookupdata nd;
4811 	struct vnode *vp;
4812 	struct uio auio;
4813 	struct iovec aiov;
4814 	int error;
4815 
4816 	error = copyin(uap->attrname, attrname, EXTATTR_MAXNAMELEN);
4817 	if (error)
4818 		return (error);
4819 
4820 	vp = NULL;
4821 
4822 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4823 	if (error == 0)
4824 		error = nlookup(&nd);
4825 	if (error == 0)
4826 		error = ncp_writechk(&nd.nl_nch);
4827 	if (error == 0)
4828 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
4829 	if (error) {
4830 		nlookup_done(&nd);
4831 		return (error);
4832 	}
4833 
4834 	bzero(&auio, sizeof(auio));
4835 	aiov.iov_base = uap->data;
4836 	aiov.iov_len = uap->nbytes;
4837 	auio.uio_iov = &aiov;
4838 	auio.uio_iovcnt = 1;
4839 	auio.uio_offset = 0;
4840 	auio.uio_resid = uap->nbytes;
4841 	auio.uio_rw = UIO_WRITE;
4842 	auio.uio_td = curthread;
4843 
4844 	error = VOP_SETEXTATTR(vp, uap->attrnamespace, attrname,
4845 			       &auio, nd.nl_cred);
4846 
4847 	vput(vp);
4848 	nlookup_done(&nd);
4849 	return (error);
4850 }
4851 
4852 /*
4853  * Syscall to get a named extended attribute on a file or directory.
4854  */
4855 int
4856 sys_extattr_get_file(struct extattr_get_file_args *uap)
4857 {
4858 	char attrname[EXTATTR_MAXNAMELEN];
4859 	struct nlookupdata nd;
4860 	struct uio auio;
4861 	struct iovec aiov;
4862 	struct vnode *vp;
4863 	int error;
4864 
4865 	error = copyin(uap->attrname, attrname, EXTATTR_MAXNAMELEN);
4866 	if (error)
4867 		return (error);
4868 
4869 	vp = NULL;
4870 
4871 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4872 	if (error == 0)
4873 		error = nlookup(&nd);
4874 	if (error == 0)
4875 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_SHARED, &vp);
4876 	if (error) {
4877 		nlookup_done(&nd);
4878 		return (error);
4879 	}
4880 
4881 	bzero(&auio, sizeof(auio));
4882 	aiov.iov_base = uap->data;
4883 	aiov.iov_len = uap->nbytes;
4884 	auio.uio_iov = &aiov;
4885 	auio.uio_iovcnt = 1;
4886 	auio.uio_offset = 0;
4887 	auio.uio_resid = uap->nbytes;
4888 	auio.uio_rw = UIO_READ;
4889 	auio.uio_td = curthread;
4890 
4891 	error = VOP_GETEXTATTR(vp, uap->attrnamespace, attrname,
4892 				&auio, nd.nl_cred);
4893 	uap->sysmsg_result = uap->nbytes - auio.uio_resid;
4894 
4895 	vput(vp);
4896 	nlookup_done(&nd);
4897 	return(error);
4898 }
4899 
4900 /*
4901  * Syscall to delete a named extended attribute from a file or directory.
4902  * Accepts attribute name.  The real work happens in VOP_SETEXTATTR().
4903  */
4904 int
4905 sys_extattr_delete_file(struct extattr_delete_file_args *uap)
4906 {
4907 	char attrname[EXTATTR_MAXNAMELEN];
4908 	struct nlookupdata nd;
4909 	struct vnode *vp;
4910 	int error;
4911 
4912 	error = copyin(uap->attrname, attrname, EXTATTR_MAXNAMELEN);
4913 	if (error)
4914 		return(error);
4915 
4916 	error = nlookup_init(&nd, uap->path, UIO_USERSPACE, NLC_FOLLOW);
4917 	if (error == 0)
4918 		error = nlookup(&nd);
4919 	if (error == 0)
4920 		error = ncp_writechk(&nd.nl_nch);
4921 	if (error == 0) {
4922 		error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp);
4923 		if (error == 0) {
4924 			error = VOP_SETEXTATTR(vp, uap->attrnamespace,
4925 					       attrname, NULL, nd.nl_cred);
4926 			vput(vp);
4927 		}
4928 	}
4929 	nlookup_done(&nd);
4930 	return(error);
4931 }
4932 
4933 /*
4934  * Determine if the mount is visible to the process.
4935  */
4936 static int
4937 chroot_visible_mnt(struct mount *mp, struct proc *p)
4938 {
4939 	struct nchandle nch;
4940 
4941 	/*
4942 	 * Traverse from the mount point upwards.  If we hit the process
4943 	 * root then the mount point is visible to the process.
4944 	 */
4945 	nch = mp->mnt_ncmountpt;
4946 	while (nch.ncp) {
4947 		if (nch.mount == p->p_fd->fd_nrdir.mount &&
4948 		    nch.ncp == p->p_fd->fd_nrdir.ncp) {
4949 			return(1);
4950 		}
4951 		if (nch.ncp == nch.mount->mnt_ncmountpt.ncp) {
4952 			nch = nch.mount->mnt_ncmounton;
4953 		} else {
4954 			nch.ncp = nch.ncp->nc_parent;
4955 		}
4956 	}
4957 
4958 	/*
4959 	 * If the mount point is not visible to the process, but the
4960 	 * process root is in a subdirectory of the mount, return
4961 	 * TRUE anyway.
4962 	 */
4963 	if (p->p_fd->fd_nrdir.mount == mp)
4964 		return(1);
4965 
4966 	return(0);
4967 }
4968 
4969