xref: /netbsd/sys/kern/vfs_subr.c (revision c4a72b64)
1 /*	$NetBSD: vfs_subr.c,v 1.182 2002/10/29 12:31:24 blymn Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the NetBSD
22  *	Foundation, Inc. and its contributors.
23  * 4. Neither the name of The NetBSD Foundation nor the names of its
24  *    contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Copyright (c) 1989, 1993
42  *	The Regents of the University of California.  All rights reserved.
43  * (c) UNIX System Laboratories, Inc.
44  * All or some portions of this file are derived from material licensed
45  * to the University of California by American Telephone and Telegraph
46  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
47  * the permission of UNIX System Laboratories, Inc.
48  *
49  * Redistribution and use in source and binary forms, with or without
50  * modification, are permitted provided that the following conditions
51  * are met:
52  * 1. Redistributions of source code must retain the above copyright
53  *    notice, this list of conditions and the following disclaimer.
54  * 2. Redistributions in binary form must reproduce the above copyright
55  *    notice, this list of conditions and the following disclaimer in the
56  *    documentation and/or other materials provided with the distribution.
57  * 3. All advertising materials mentioning features or use of this software
58  *    must display the following acknowledgement:
59  *	This product includes software developed by the University of
60  *	California, Berkeley and its contributors.
61  * 4. Neither the name of the University nor the names of its contributors
62  *    may be used to endorse or promote products derived from this software
63  *    without specific prior written permission.
64  *
65  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
66  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
67  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
68  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
69  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
70  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
71  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
72  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
73  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
74  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
75  * SUCH DAMAGE.
76  *
77  *	@(#)vfs_subr.c	8.13 (Berkeley) 4/18/94
78  */
79 
80 /*
81  * External virtual filesystem routines
82  */
83 
84 #include <sys/cdefs.h>
85 __KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.182 2002/10/29 12:31:24 blymn Exp $");
86 
87 #include "opt_ddb.h"
88 #include "opt_compat_netbsd.h"
89 #include "opt_compat_43.h"
90 
91 #include <sys/param.h>
92 #include <sys/systm.h>
93 #include <sys/proc.h>
94 #include <sys/kernel.h>
95 #include <sys/mount.h>
96 #include <sys/time.h>
97 #include <sys/event.h>
98 #include <sys/fcntl.h>
99 #include <sys/vnode.h>
100 #include <sys/stat.h>
101 #include <sys/namei.h>
102 #include <sys/ucred.h>
103 #include <sys/buf.h>
104 #include <sys/errno.h>
105 #include <sys/malloc.h>
106 #include <sys/domain.h>
107 #include <sys/mbuf.h>
108 #include <sys/syscallargs.h>
109 #include <sys/device.h>
110 #include <sys/dirent.h>
111 
112 #include <miscfs/specfs/specdev.h>
113 #include <miscfs/genfs/genfs.h>
114 #include <miscfs/syncfs/syncfs.h>
115 
116 #include <uvm/uvm.h>
117 #include <uvm/uvm_ddb.h>
118 
119 #include <sys/sysctl.h>
120 
121 enum vtype iftovt_tab[16] = {
122 	VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
123 	VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
124 };
125 const int	vttoif_tab[9] = {
126 	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
127 	S_IFSOCK, S_IFIFO, S_IFMT,
128 };
129 
130 int doforce = 1;		/* 1 => permit forcible unmounting */
131 int prtactive = 0;		/* 1 => print out reclaim of active vnodes */
132 
133 extern int dovfsusermount;	/* 1 => permit any user to mount filesystems */
134 
135 /*
136  * Insq/Remq for the vnode usage lists.
137  */
138 #define	bufinsvn(bp, dp)	LIST_INSERT_HEAD(dp, bp, b_vnbufs)
139 #define	bufremvn(bp) {							\
140 	LIST_REMOVE(bp, b_vnbufs);					\
141 	(bp)->b_vnbufs.le_next = NOLIST;				\
142 }
143 /* TAILQ_HEAD(freelst, vnode) vnode_free_list =	vnode free list (in vnode.h) */
144 struct freelst vnode_free_list = TAILQ_HEAD_INITIALIZER(vnode_free_list);
145 struct freelst vnode_hold_list = TAILQ_HEAD_INITIALIZER(vnode_hold_list);
146 
147 struct mntlist mountlist =			/* mounted filesystem list */
148     CIRCLEQ_HEAD_INITIALIZER(mountlist);
149 struct vfs_list_head vfs_list =			/* vfs list */
150     LIST_HEAD_INITIALIZER(vfs_list);
151 
152 struct nfs_public nfs_pub;			/* publicly exported FS */
153 
154 struct simplelock mountlist_slock = SIMPLELOCK_INITIALIZER;
155 static struct simplelock mntid_slock = SIMPLELOCK_INITIALIZER;
156 struct simplelock mntvnode_slock = SIMPLELOCK_INITIALIZER;
157 struct simplelock vnode_free_list_slock = SIMPLELOCK_INITIALIZER;
158 struct simplelock spechash_slock = SIMPLELOCK_INITIALIZER;
159 
160 /*
161  * These define the root filesystem and device.
162  */
163 struct mount *rootfs;
164 struct vnode *rootvnode;
165 struct device *root_device;			/* root device */
166 
167 struct pool vnode_pool;				/* memory pool for vnodes */
168 
169 /*
170  * Local declarations.
171  */
172 void insmntque __P((struct vnode *, struct mount *));
173 int getdevvp __P((dev_t, struct vnode **, enum vtype));
174 void vgoneall __P((struct vnode *));
175 
176 void vclean(struct vnode *, int, struct proc *);
177 
178 static int vfs_hang_addrlist __P((struct mount *, struct netexport *,
179 				  struct export_args *));
180 static int vfs_free_netcred __P((struct radix_node *, void *));
181 static void vfs_free_addrlist __P((struct netexport *));
182 
183 #ifdef DEBUG
184 void printlockedvnodes __P((void));
185 #endif
186 
187 /*
188  * Initialize the vnode management data structures.
189  */
190 void
191 vntblinit()
192 {
193 
194 	pool_init(&vnode_pool, sizeof(struct vnode), 0, 0, 0, "vnodepl",
195 	    &pool_allocator_nointr);
196 
197 	/*
198 	 * Initialize the filesystem syncer.
199 	 */
200 	vn_initialize_syncerd();
201 }
202 
203 /*
204  * Mark a mount point as busy. Used to synchronize access and to delay
205  * unmounting. Interlock is not released on failure.
206  */
207 int
208 vfs_busy(mp, flags, interlkp)
209 	struct mount *mp;
210 	int flags;
211 	struct simplelock *interlkp;
212 {
213 	int lkflags;
214 
215 	while (mp->mnt_flag & MNT_UNMOUNT) {
216 		int gone;
217 
218 		if (flags & LK_NOWAIT)
219 			return (ENOENT);
220 		if ((flags & LK_RECURSEFAIL) && mp->mnt_unmounter != NULL
221 		    && mp->mnt_unmounter == curproc)
222 			return (EDEADLK);
223 		if (interlkp)
224 			simple_unlock(interlkp);
225 		/*
226 		 * Since all busy locks are shared except the exclusive
227 		 * lock granted when unmounting, the only place that a
228 		 * wakeup needs to be done is at the release of the
229 		 * exclusive lock at the end of dounmount.
230 		 *
231 		 * XXX MP: add spinlock protecting mnt_wcnt here once you
232 		 * can atomically unlock-and-sleep.
233 		 */
234 		mp->mnt_wcnt++;
235 		tsleep((caddr_t)mp, PVFS, "vfs_busy", 0);
236 		mp->mnt_wcnt--;
237 		gone = mp->mnt_flag & MNT_GONE;
238 
239 		if (mp->mnt_wcnt == 0)
240 			wakeup(&mp->mnt_wcnt);
241 		if (interlkp)
242 			simple_lock(interlkp);
243 		if (gone)
244 			return (ENOENT);
245 	}
246 	lkflags = LK_SHARED;
247 	if (interlkp)
248 		lkflags |= LK_INTERLOCK;
249 	if (lockmgr(&mp->mnt_lock, lkflags, interlkp))
250 		panic("vfs_busy: unexpected lock failure");
251 	return (0);
252 }
253 
254 /*
255  * Free a busy filesystem.
256  */
257 void
258 vfs_unbusy(mp)
259 	struct mount *mp;
260 {
261 
262 	lockmgr(&mp->mnt_lock, LK_RELEASE, NULL);
263 }
264 
265 /*
266  * Lookup a filesystem type, and if found allocate and initialize
267  * a mount structure for it.
268  *
269  * Devname is usually updated by mount(8) after booting.
270  */
271 int
272 vfs_rootmountalloc(fstypename, devname, mpp)
273 	char *fstypename;
274 	char *devname;
275 	struct mount **mpp;
276 {
277 	struct vfsops *vfsp = NULL;
278 	struct mount *mp;
279 
280 	LIST_FOREACH(vfsp, &vfs_list, vfs_list)
281 		if (!strncmp(vfsp->vfs_name, fstypename, MFSNAMELEN))
282 			break;
283 
284 	if (vfsp == NULL)
285 		return (ENODEV);
286 	mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
287 	memset((char *)mp, 0, (u_long)sizeof(struct mount));
288 	lockinit(&mp->mnt_lock, PVFS, "vfslock", 0, 0);
289 	(void)vfs_busy(mp, LK_NOWAIT, 0);
290 	LIST_INIT(&mp->mnt_vnodelist);
291 	mp->mnt_op = vfsp;
292 	mp->mnt_flag = MNT_RDONLY;
293 	mp->mnt_vnodecovered = NULLVP;
294 	vfsp->vfs_refcount++;
295 	strncpy(mp->mnt_stat.f_fstypename, vfsp->vfs_name, MFSNAMELEN);
296 	mp->mnt_stat.f_mntonname[0] = '/';
297 	(void) copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0);
298 	*mpp = mp;
299 	return (0);
300 }
301 
302 /*
303  * Lookup a mount point by filesystem identifier.
304  */
305 struct mount *
306 vfs_getvfs(fsid)
307 	fsid_t *fsid;
308 {
309 	struct mount *mp;
310 
311 	simple_lock(&mountlist_slock);
312 	CIRCLEQ_FOREACH(mp, &mountlist, mnt_list) {
313 		if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
314 		    mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
315 			simple_unlock(&mountlist_slock);
316 			return (mp);
317 		}
318 	}
319 	simple_unlock(&mountlist_slock);
320 	return ((struct mount *)0);
321 }
322 
323 /*
324  * Get a new unique fsid
325  */
326 void
327 vfs_getnewfsid(mp)
328 	struct mount *mp;
329 {
330 	static u_short xxxfs_mntid;
331 	fsid_t tfsid;
332 	int mtype;
333 
334 	simple_lock(&mntid_slock);
335 	mtype = makefstype(mp->mnt_op->vfs_name);
336 	mp->mnt_stat.f_fsid.val[0] = makedev(mtype, 0);
337 	mp->mnt_stat.f_fsid.val[1] = mtype;
338 	if (xxxfs_mntid == 0)
339 		++xxxfs_mntid;
340 	tfsid.val[0] = makedev(mtype & 0xff, xxxfs_mntid);
341 	tfsid.val[1] = mtype;
342 	if (!CIRCLEQ_EMPTY(&mountlist)) {
343 		while (vfs_getvfs(&tfsid)) {
344 			tfsid.val[0]++;
345 			xxxfs_mntid++;
346 		}
347 	}
348 	mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
349 	simple_unlock(&mntid_slock);
350 }
351 
352 /*
353  * Make a 'unique' number from a mount type name.
354  */
355 long
356 makefstype(type)
357 	const char *type;
358 {
359 	long rv;
360 
361 	for (rv = 0; *type; type++) {
362 		rv <<= 2;
363 		rv ^= *type;
364 	}
365 	return rv;
366 }
367 
368 
369 /*
370  * Set vnode attributes to VNOVAL
371  */
372 void
373 vattr_null(vap)
374 	struct vattr *vap;
375 {
376 
377 	vap->va_type = VNON;
378 
379 	/*
380 	 * Assign individually so that it is safe even if size and
381 	 * sign of each member are varied.
382 	 */
383 	vap->va_mode = VNOVAL;
384 	vap->va_nlink = VNOVAL;
385 	vap->va_uid = VNOVAL;
386 	vap->va_gid = VNOVAL;
387 	vap->va_fsid = VNOVAL;
388 	vap->va_fileid = VNOVAL;
389 	vap->va_size = VNOVAL;
390 	vap->va_blocksize = VNOVAL;
391 	vap->va_atime.tv_sec =
392 	    vap->va_mtime.tv_sec =
393 	    vap->va_ctime.tv_sec = VNOVAL;
394 	vap->va_atime.tv_nsec =
395 	    vap->va_mtime.tv_nsec =
396 	    vap->va_ctime.tv_nsec = VNOVAL;
397 	vap->va_gen = VNOVAL;
398 	vap->va_flags = VNOVAL;
399 	vap->va_rdev = VNOVAL;
400 	vap->va_bytes = VNOVAL;
401 	vap->va_vaflags = 0;
402 }
403 
404 /*
405  * Routines having to do with the management of the vnode table.
406  */
407 extern int (**dead_vnodeop_p) __P((void *));
408 long numvnodes;
409 
410 /*
411  * Return the next vnode from the free list.
412  */
413 int
414 getnewvnode(tag, mp, vops, vpp)
415 	enum vtagtype tag;
416 	struct mount *mp;
417 	int (**vops) __P((void *));
418 	struct vnode **vpp;
419 {
420 	extern struct uvm_pagerops uvm_vnodeops;
421 	struct uvm_object *uobj;
422 	struct proc *p = curproc;	/* XXX */
423 	struct freelst *listhd;
424 	static int toggle;
425 	struct vnode *vp;
426 	int error = 0, tryalloc;
427 
428  try_again:
429 	if (mp) {
430 		/*
431 		 * Mark filesystem busy while we're creating a vnode.
432 		 * If unmount is in progress, this will wait; if the
433 		 * unmount succeeds (only if umount -f), this will
434 		 * return an error.  If the unmount fails, we'll keep
435 		 * going afterwards.
436 		 * (This puts the per-mount vnode list logically under
437 		 * the protection of the vfs_busy lock).
438 		 */
439 		error = vfs_busy(mp, LK_RECURSEFAIL, 0);
440 		if (error && error != EDEADLK)
441 			return error;
442 	}
443 
444 	/*
445 	 * We must choose whether to allocate a new vnode or recycle an
446 	 * existing one. The criterion for allocating a new one is that
447 	 * the total number of vnodes is less than the number desired or
448 	 * there are no vnodes on either free list. Generally we only
449 	 * want to recycle vnodes that have no buffers associated with
450 	 * them, so we look first on the vnode_free_list. If it is empty,
451 	 * we next consider vnodes with referencing buffers on the
452 	 * vnode_hold_list. The toggle ensures that half the time we
453 	 * will use a buffer from the vnode_hold_list, and half the time
454 	 * we will allocate a new one unless the list has grown to twice
455 	 * the desired size. We are reticent to recycle vnodes from the
456 	 * vnode_hold_list because we will lose the identity of all its
457 	 * referencing buffers.
458 	 */
459 
460 	vp = NULL;
461 
462 	simple_lock(&vnode_free_list_slock);
463 
464 	toggle ^= 1;
465 	if (numvnodes > 2 * desiredvnodes)
466 		toggle = 0;
467 
468 	tryalloc = numvnodes < desiredvnodes ||
469 	    (TAILQ_FIRST(&vnode_free_list) == NULL &&
470 	     (TAILQ_FIRST(&vnode_hold_list) == NULL || toggle));
471 
472 	if (tryalloc &&
473 	    (vp = pool_get(&vnode_pool, PR_NOWAIT)) != NULL) {
474 		simple_unlock(&vnode_free_list_slock);
475 		memset(vp, 0, sizeof(*vp));
476 		simple_lock_init(&vp->v_interlock);
477 		uobj = &vp->v_uobj;
478 		uobj->pgops = &uvm_vnodeops;
479 		uobj->uo_npages = 0;
480 		TAILQ_INIT(&uobj->memq);
481 		numvnodes++;
482 	} else {
483 		if ((vp = TAILQ_FIRST(listhd = &vnode_free_list)) == NULL)
484 			vp = TAILQ_FIRST(listhd = &vnode_hold_list);
485 		for (; vp != NULL; vp = TAILQ_NEXT(vp, v_freelist)) {
486 			if (simple_lock_try(&vp->v_interlock)) {
487 				if ((vp->v_flag & VLAYER) == 0) {
488 					break;
489 				}
490 				if (VOP_ISLOCKED(vp) == 0)
491 					break;
492 				else
493 					simple_unlock(&vp->v_interlock);
494 			}
495 		}
496 		/*
497 		 * Unless this is a bad time of the month, at most
498 		 * the first NCPUS items on the free list are
499 		 * locked, so this is close enough to being empty.
500 		 */
501 		if (vp == NULLVP) {
502 			simple_unlock(&vnode_free_list_slock);
503 			if (mp && error != EDEADLK)
504 				vfs_unbusy(mp);
505 			if (tryalloc) {
506 				printf("WARNING: unable to allocate new "
507 				    "vnode, retrying...\n");
508 				(void) tsleep(&lbolt, PRIBIO, "newvn", hz);
509 				goto try_again;
510 			}
511 			tablefull("vnode", "increase kern.maxvnodes or NVNODE");
512 			*vpp = 0;
513 			return (ENFILE);
514 		}
515 		if (vp->v_usecount)
516 			panic("free vnode isn't, vp %p", vp);
517 		TAILQ_REMOVE(listhd, vp, v_freelist);
518 		/* see comment on why 0xdeadb is set at end of vgone (below) */
519 		vp->v_freelist.tqe_prev = (struct vnode **)0xdeadb;
520 		simple_unlock(&vnode_free_list_slock);
521 		vp->v_lease = NULL;
522 
523 		if (vp->v_type != VBAD)
524 			vgonel(vp, p);
525 		else
526 			simple_unlock(&vp->v_interlock);
527 #ifdef DIAGNOSTIC
528 		if (vp->v_data || vp->v_uobj.uo_npages ||
529 		    TAILQ_FIRST(&vp->v_uobj.memq))
530 			panic("cleaned vnode isn't, vp %p", vp);
531 		if (vp->v_numoutput)
532 			panic("clean vnode has pending I/O's, vp %p", vp);
533 #endif
534 		KASSERT((vp->v_flag & VONWORKLST) == 0);
535 		vp->v_flag = 0;
536 		vp->v_socket = NULL;
537 #ifdef VERIFIED_EXEC
538 		vp->fp_status = FINGERPRINT_INVALID;
539 #endif
540 	}
541 	vp->v_type = VNON;
542 	vp->v_vnlock = &vp->v_lock;
543 	lockinit(vp->v_vnlock, PVFS, "vnlock", 0, 0);
544 	cache_purge(vp);
545 	vp->v_tag = tag;
546 	vp->v_op = vops;
547 	insmntque(vp, mp);
548 	*vpp = vp;
549 	vp->v_usecount = 1;
550 	vp->v_data = 0;
551 	simple_lock_init(&vp->v_uobj.vmobjlock);
552 
553 	/*
554 	 * initialize uvm_object within vnode.
555 	 */
556 
557 	uobj = &vp->v_uobj;
558 	KASSERT(uobj->pgops == &uvm_vnodeops);
559 	KASSERT(uobj->uo_npages == 0);
560 	KASSERT(TAILQ_FIRST(&uobj->memq) == NULL);
561 	vp->v_size = VSIZENOTSET;
562 
563 	if (mp && error != EDEADLK)
564 		vfs_unbusy(mp);
565 	return (0);
566 }
567 
568 /*
569  * This is really just the reverse of getnewvnode(). Needed for
570  * VFS_VGET functions who may need to push back a vnode in case
571  * of a locking race.
572  */
573 void
574 ungetnewvnode(vp)
575 	struct vnode *vp;
576 {
577 #ifdef DIAGNOSTIC
578 	if (vp->v_usecount != 1)
579 		panic("ungetnewvnode: busy vnode");
580 #endif
581 	vp->v_usecount--;
582 	insmntque(vp, NULL);
583 	vp->v_type = VBAD;
584 
585 	simple_lock(&vp->v_interlock);
586 	/*
587 	 * Insert at head of LRU list
588 	 */
589 	simple_lock(&vnode_free_list_slock);
590 	if (vp->v_holdcnt > 0)
591 		TAILQ_INSERT_HEAD(&vnode_hold_list, vp, v_freelist);
592 	else
593 		TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
594 	simple_unlock(&vnode_free_list_slock);
595 	simple_unlock(&vp->v_interlock);
596 }
597 
598 /*
599  * Move a vnode from one mount queue to another.
600  */
601 void
602 insmntque(vp, mp)
603 	struct vnode *vp;
604 	struct mount *mp;
605 {
606 
607 #ifdef DIAGNOSTIC
608 	if ((mp != NULL) &&
609 	    (mp->mnt_flag & MNT_UNMOUNT) &&
610 	    !(mp->mnt_flag & MNT_SOFTDEP) &&
611 	    vp->v_tag != VT_VFS) {
612 		panic("insmntque into dying filesystem");
613 	}
614 #endif
615 
616 	simple_lock(&mntvnode_slock);
617 	/*
618 	 * Delete from old mount point vnode list, if on one.
619 	 */
620 	if (vp->v_mount != NULL)
621 		LIST_REMOVE(vp, v_mntvnodes);
622 	/*
623 	 * Insert into list of vnodes for the new mount point, if available.
624 	 */
625 	if ((vp->v_mount = mp) != NULL)
626 		LIST_INSERT_HEAD(&mp->mnt_vnodelist, vp, v_mntvnodes);
627 	simple_unlock(&mntvnode_slock);
628 }
629 
630 /*
631  * Update outstanding I/O count and do wakeup if requested.
632  */
633 void
634 vwakeup(bp)
635 	struct buf *bp;
636 {
637 	struct vnode *vp;
638 
639 	if ((vp = bp->b_vp) != NULL) {
640 		if (--vp->v_numoutput < 0)
641 			panic("vwakeup: neg numoutput, vp %p", vp);
642 		if ((vp->v_flag & VBWAIT) && vp->v_numoutput <= 0) {
643 			vp->v_flag &= ~VBWAIT;
644 			wakeup((caddr_t)&vp->v_numoutput);
645 		}
646 	}
647 }
648 
649 /*
650  * Flush out and invalidate all buffers associated with a vnode.
651  * Called with the underlying vnode locked, which should prevent new dirty
652  * buffers from being queued.
653  */
654 int
655 vinvalbuf(vp, flags, cred, p, slpflag, slptimeo)
656 	struct vnode *vp;
657 	int flags;
658 	struct ucred *cred;
659 	struct proc *p;
660 	int slpflag, slptimeo;
661 {
662 	struct buf *bp, *nbp;
663 	int s, error;
664 	int flushflags = PGO_ALLPAGES | PGO_FREE | PGO_SYNCIO |
665 		(flags & V_SAVE ? PGO_CLEANIT : 0);
666 
667 	/* XXXUBC this doesn't look at flags or slp* */
668 	simple_lock(&vp->v_interlock);
669 	error = VOP_PUTPAGES(vp, 0, 0, flushflags);
670 	if (error) {
671 		return error;
672 	}
673 
674 	if (flags & V_SAVE) {
675 		error = VOP_FSYNC(vp, cred, FSYNC_WAIT|FSYNC_RECLAIM, 0, 0, p);
676 		if (error)
677 		        return (error);
678 #ifdef DIAGNOSTIC
679 		s = splbio();
680 		if (vp->v_numoutput > 0 || !LIST_EMPTY(&vp->v_dirtyblkhd))
681 		        panic("vinvalbuf: dirty bufs, vp %p", vp);
682 		splx(s);
683 #endif
684 	}
685 
686 	s = splbio();
687 
688 restart:
689 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
690 		nbp = LIST_NEXT(bp, b_vnbufs);
691 		if (bp->b_flags & B_BUSY) {
692 			bp->b_flags |= B_WANTED;
693 			error = tsleep((caddr_t)bp, slpflag | (PRIBIO + 1),
694 			    "vinvalbuf", slptimeo);
695 			if (error) {
696 				splx(s);
697 				return (error);
698 			}
699 			goto restart;
700 		}
701 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
702 		brelse(bp);
703 	}
704 
705 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
706 		nbp = LIST_NEXT(bp, b_vnbufs);
707 		if (bp->b_flags & B_BUSY) {
708 			bp->b_flags |= B_WANTED;
709 			error = tsleep((caddr_t)bp, slpflag | (PRIBIO + 1),
710 			    "vinvalbuf", slptimeo);
711 			if (error) {
712 				splx(s);
713 				return (error);
714 			}
715 			goto restart;
716 		}
717 		/*
718 		 * XXX Since there are no node locks for NFS, I believe
719 		 * there is a slight chance that a delayed write will
720 		 * occur while sleeping just above, so check for it.
721 		 */
722 		if ((bp->b_flags & B_DELWRI) && (flags & V_SAVE)) {
723 #ifdef DEBUG
724 			printf("buffer still DELWRI\n");
725 #endif
726 			bp->b_flags |= B_BUSY | B_VFLUSH;
727 			VOP_BWRITE(bp);
728 			goto restart;
729 		}
730 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
731 		brelse(bp);
732 	}
733 
734 #ifdef DIAGNOSTIC
735 	if (!LIST_EMPTY(&vp->v_cleanblkhd) || !LIST_EMPTY(&vp->v_dirtyblkhd))
736 		panic("vinvalbuf: flush failed, vp %p", vp);
737 #endif
738 
739 	splx(s);
740 
741 	return (0);
742 }
743 
744 /*
745  * Destroy any in core blocks past the truncation length.
746  * Called with the underlying vnode locked, which should prevent new dirty
747  * buffers from being queued.
748  */
749 int
750 vtruncbuf(vp, lbn, slpflag, slptimeo)
751 	struct vnode *vp;
752 	daddr_t lbn;
753 	int slpflag, slptimeo;
754 {
755 	struct buf *bp, *nbp;
756 	int s, error;
757 	voff_t off;
758 
759 	off = round_page((voff_t)lbn << vp->v_mount->mnt_fs_bshift);
760 	simple_lock(&vp->v_interlock);
761 	error = VOP_PUTPAGES(vp, off, 0, PGO_FREE | PGO_SYNCIO);
762 	if (error) {
763 		return error;
764 	}
765 
766 	s = splbio();
767 
768 restart:
769 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
770 		nbp = LIST_NEXT(bp, b_vnbufs);
771 		if (bp->b_lblkno < lbn)
772 			continue;
773 		if (bp->b_flags & B_BUSY) {
774 			bp->b_flags |= B_WANTED;
775 			error = tsleep(bp, slpflag | (PRIBIO + 1),
776 			    "vtruncbuf", slptimeo);
777 			if (error) {
778 				splx(s);
779 				return (error);
780 			}
781 			goto restart;
782 		}
783 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
784 		brelse(bp);
785 	}
786 
787 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
788 		nbp = LIST_NEXT(bp, b_vnbufs);
789 		if (bp->b_lblkno < lbn)
790 			continue;
791 		if (bp->b_flags & B_BUSY) {
792 			bp->b_flags |= B_WANTED;
793 			error = tsleep(bp, slpflag | (PRIBIO + 1),
794 			    "vtruncbuf", slptimeo);
795 			if (error) {
796 				splx(s);
797 				return (error);
798 			}
799 			goto restart;
800 		}
801 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
802 		brelse(bp);
803 	}
804 
805 	splx(s);
806 
807 	return (0);
808 }
809 
810 void
811 vflushbuf(vp, sync)
812 	struct vnode *vp;
813 	int sync;
814 {
815 	struct buf *bp, *nbp;
816 	int flags = PGO_CLEANIT | PGO_ALLPAGES | (sync ? PGO_SYNCIO : 0);
817 	int s;
818 
819 	simple_lock(&vp->v_interlock);
820 	(void) VOP_PUTPAGES(vp, 0, 0, flags);
821 
822 loop:
823 	s = splbio();
824 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
825 		nbp = LIST_NEXT(bp, b_vnbufs);
826 		if ((bp->b_flags & B_BUSY))
827 			continue;
828 		if ((bp->b_flags & B_DELWRI) == 0)
829 			panic("vflushbuf: not dirty, bp %p", bp);
830 		bp->b_flags |= B_BUSY | B_VFLUSH;
831 		splx(s);
832 		/*
833 		 * Wait for I/O associated with indirect blocks to complete,
834 		 * since there is no way to quickly wait for them below.
835 		 */
836 		if (bp->b_vp == vp || sync == 0)
837 			(void) bawrite(bp);
838 		else
839 			(void) bwrite(bp);
840 		goto loop;
841 	}
842 	if (sync == 0) {
843 		splx(s);
844 		return;
845 	}
846 	while (vp->v_numoutput) {
847 		vp->v_flag |= VBWAIT;
848 		tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "vflushbuf", 0);
849 	}
850 	splx(s);
851 	if (!LIST_EMPTY(&vp->v_dirtyblkhd)) {
852 		vprint("vflushbuf: dirty", vp);
853 		goto loop;
854 	}
855 }
856 
857 /*
858  * Associate a buffer with a vnode.
859  */
860 void
861 bgetvp(vp, bp)
862 	struct vnode *vp;
863 	struct buf *bp;
864 {
865 	int s;
866 
867 	if (bp->b_vp)
868 		panic("bgetvp: not free, bp %p", bp);
869 	VHOLD(vp);
870 	s = splbio();
871 	bp->b_vp = vp;
872 	if (vp->v_type == VBLK || vp->v_type == VCHR)
873 		bp->b_dev = vp->v_rdev;
874 	else
875 		bp->b_dev = NODEV;
876 	/*
877 	 * Insert onto list for new vnode.
878 	 */
879 	bufinsvn(bp, &vp->v_cleanblkhd);
880 	splx(s);
881 }
882 
883 /*
884  * Disassociate a buffer from a vnode.
885  */
886 void
887 brelvp(bp)
888 	struct buf *bp;
889 {
890 	struct vnode *vp;
891 	int s;
892 
893 	if (bp->b_vp == NULL)
894 		panic("brelvp: vp NULL, bp %p", bp);
895 
896 	s = splbio();
897 	vp = bp->b_vp;
898 	/*
899 	 * Delete from old vnode list, if on one.
900 	 */
901 	if (LIST_NEXT(bp, b_vnbufs) != NOLIST)
902 		bufremvn(bp);
903 
904 	if (TAILQ_EMPTY(&vp->v_uobj.memq) && (vp->v_flag & VONWORKLST) &&
905 	    LIST_FIRST(&vp->v_dirtyblkhd) == NULL) {
906 		vp->v_flag &= ~VONWORKLST;
907 		LIST_REMOVE(vp, v_synclist);
908 	}
909 
910 	bp->b_vp = NULL;
911 	HOLDRELE(vp);
912 	splx(s);
913 }
914 
915 /*
916  * Reassign a buffer from one vnode to another.
917  * Used to assign file specific control information
918  * (indirect blocks) to the vnode to which they belong.
919  *
920  * This function must be called at splbio().
921  */
922 void
923 reassignbuf(bp, newvp)
924 	struct buf *bp;
925 	struct vnode *newvp;
926 {
927 	struct buflists *listheadp;
928 	int delay;
929 
930 	/*
931 	 * Delete from old vnode list, if on one.
932 	 */
933 	if (LIST_NEXT(bp, b_vnbufs) != NOLIST)
934 		bufremvn(bp);
935 	/*
936 	 * If dirty, put on list of dirty buffers;
937 	 * otherwise insert onto list of clean buffers.
938 	 */
939 	if ((bp->b_flags & B_DELWRI) == 0) {
940 		listheadp = &newvp->v_cleanblkhd;
941 		if (TAILQ_EMPTY(&newvp->v_uobj.memq) &&
942 		    (newvp->v_flag & VONWORKLST) &&
943 		    LIST_FIRST(&newvp->v_dirtyblkhd) == NULL) {
944 			newvp->v_flag &= ~VONWORKLST;
945 			LIST_REMOVE(newvp, v_synclist);
946 		}
947 	} else {
948 		listheadp = &newvp->v_dirtyblkhd;
949 		if ((newvp->v_flag & VONWORKLST) == 0) {
950 			switch (newvp->v_type) {
951 			case VDIR:
952 				delay = dirdelay;
953 				break;
954 			case VBLK:
955 				if (newvp->v_specmountpoint != NULL) {
956 					delay = metadelay;
957 					break;
958 				}
959 				/* fall through */
960 			default:
961 				delay = filedelay;
962 				break;
963 			}
964 			if (!newvp->v_mount ||
965 			    (newvp->v_mount->mnt_flag & MNT_ASYNC) == 0)
966 				vn_syncer_add_to_worklist(newvp, delay);
967 		}
968 	}
969 	bufinsvn(bp, listheadp);
970 }
971 
972 /*
973  * Create a vnode for a block device.
974  * Used for root filesystem and swap areas.
975  * Also used for memory file system special devices.
976  */
977 int
978 bdevvp(dev, vpp)
979 	dev_t dev;
980 	struct vnode **vpp;
981 {
982 
983 	return (getdevvp(dev, vpp, VBLK));
984 }
985 
986 /*
987  * Create a vnode for a character device.
988  * Used for kernfs and some console handling.
989  */
990 int
991 cdevvp(dev, vpp)
992 	dev_t dev;
993 	struct vnode **vpp;
994 {
995 
996 	return (getdevvp(dev, vpp, VCHR));
997 }
998 
999 /*
1000  * Create a vnode for a device.
1001  * Used by bdevvp (block device) for root file system etc.,
1002  * and by cdevvp (character device) for console and kernfs.
1003  */
1004 int
1005 getdevvp(dev, vpp, type)
1006 	dev_t dev;
1007 	struct vnode **vpp;
1008 	enum vtype type;
1009 {
1010 	struct vnode *vp;
1011 	struct vnode *nvp;
1012 	int error;
1013 
1014 	if (dev == NODEV) {
1015 		*vpp = NULLVP;
1016 		return (0);
1017 	}
1018 	error = getnewvnode(VT_NON, NULL, spec_vnodeop_p, &nvp);
1019 	if (error) {
1020 		*vpp = NULLVP;
1021 		return (error);
1022 	}
1023 	vp = nvp;
1024 	vp->v_type = type;
1025 	if ((nvp = checkalias(vp, dev, NULL)) != 0) {
1026 		vput(vp);
1027 		vp = nvp;
1028 	}
1029 	*vpp = vp;
1030 	return (0);
1031 }
1032 
1033 /*
1034  * Check to see if the new vnode represents a special device
1035  * for which we already have a vnode (either because of
1036  * bdevvp() or because of a different vnode representing
1037  * the same block device). If such an alias exists, deallocate
1038  * the existing contents and return the aliased vnode. The
1039  * caller is responsible for filling it with its new contents.
1040  */
1041 struct vnode *
1042 checkalias(nvp, nvp_rdev, mp)
1043 	struct vnode *nvp;
1044 	dev_t nvp_rdev;
1045 	struct mount *mp;
1046 {
1047 	struct proc *p = curproc;       /* XXX */
1048 	struct vnode *vp;
1049 	struct vnode **vpp;
1050 
1051 	if (nvp->v_type != VBLK && nvp->v_type != VCHR)
1052 		return (NULLVP);
1053 
1054 	vpp = &speclisth[SPECHASH(nvp_rdev)];
1055 loop:
1056 	simple_lock(&spechash_slock);
1057 	for (vp = *vpp; vp; vp = vp->v_specnext) {
1058 		if (nvp_rdev != vp->v_rdev || nvp->v_type != vp->v_type)
1059 			continue;
1060 		/*
1061 		 * Alias, but not in use, so flush it out.
1062 		 */
1063 		simple_lock(&vp->v_interlock);
1064 		if (vp->v_usecount == 0) {
1065 			simple_unlock(&spechash_slock);
1066 			vgonel(vp, p);
1067 			goto loop;
1068 		}
1069 		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK)) {
1070 			simple_unlock(&spechash_slock);
1071 			goto loop;
1072 		}
1073 		break;
1074 	}
1075 	if (vp == NULL || vp->v_tag != VT_NON || vp->v_type != VBLK) {
1076 		MALLOC(nvp->v_specinfo, struct specinfo *,
1077 			sizeof(struct specinfo), M_VNODE, M_NOWAIT);
1078 		/* XXX Erg. */
1079 		if (nvp->v_specinfo == NULL) {
1080 			simple_unlock(&spechash_slock);
1081 			uvm_wait("checkalias");
1082 			goto loop;
1083 		}
1084 
1085 		nvp->v_rdev = nvp_rdev;
1086 		nvp->v_hashchain = vpp;
1087 		nvp->v_specnext = *vpp;
1088 		nvp->v_specmountpoint = NULL;
1089 		simple_unlock(&spechash_slock);
1090 		nvp->v_speclockf = NULL;
1091 		*vpp = nvp;
1092 		if (vp != NULLVP) {
1093 			nvp->v_flag |= VALIASED;
1094 			vp->v_flag |= VALIASED;
1095 			vput(vp);
1096 		}
1097 		return (NULLVP);
1098 	}
1099 	simple_unlock(&spechash_slock);
1100 	VOP_UNLOCK(vp, 0);
1101 	simple_lock(&vp->v_interlock);
1102 	vclean(vp, 0, p);
1103 	vp->v_op = nvp->v_op;
1104 	vp->v_tag = nvp->v_tag;
1105 	vp->v_vnlock = &vp->v_lock;
1106 	lockinit(vp->v_vnlock, PVFS, "vnlock", 0, 0);
1107 	nvp->v_type = VNON;
1108 	insmntque(vp, mp);
1109 	return (vp);
1110 }
1111 
1112 /*
1113  * Grab a particular vnode from the free list, increment its
1114  * reference count and lock it. If the vnode lock bit is set the
1115  * vnode is being eliminated in vgone. In that case, we can not
1116  * grab the vnode, so the process is awakened when the transition is
1117  * completed, and an error returned to indicate that the vnode is no
1118  * longer usable (possibly having been changed to a new file system type).
1119  */
1120 int
1121 vget(vp, flags)
1122 	struct vnode *vp;
1123 	int flags;
1124 {
1125 	int error;
1126 
1127 	/*
1128 	 * If the vnode is in the process of being cleaned out for
1129 	 * another use, we wait for the cleaning to finish and then
1130 	 * return failure. Cleaning is determined by checking that
1131 	 * the VXLOCK flag is set.
1132 	 */
1133 
1134 	if ((flags & LK_INTERLOCK) == 0)
1135 		simple_lock(&vp->v_interlock);
1136 	if (vp->v_flag & VXLOCK) {
1137 		if (flags & LK_NOWAIT) {
1138 			simple_unlock(&vp->v_interlock);
1139 			return EBUSY;
1140 		}
1141 		vp->v_flag |= VXWANT;
1142 		ltsleep(vp, PINOD|PNORELOCK, "vget", 0, &vp->v_interlock);
1143 		return (ENOENT);
1144 	}
1145 	if (vp->v_usecount == 0) {
1146 		simple_lock(&vnode_free_list_slock);
1147 		if (vp->v_holdcnt > 0)
1148 			TAILQ_REMOVE(&vnode_hold_list, vp, v_freelist);
1149 		else
1150 			TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
1151 		simple_unlock(&vnode_free_list_slock);
1152 	}
1153 	vp->v_usecount++;
1154 #ifdef DIAGNOSTIC
1155 	if (vp->v_usecount == 0) {
1156 		vprint("vget", vp);
1157 		panic("vget: usecount overflow, vp %p", vp);
1158 	}
1159 #endif
1160 	if (flags & LK_TYPE_MASK) {
1161 		if ((error = vn_lock(vp, flags | LK_INTERLOCK))) {
1162 			/*
1163 			 * must expand vrele here because we do not want
1164 			 * to call VOP_INACTIVE if the reference count
1165 			 * drops back to zero since it was never really
1166 			 * active. We must remove it from the free list
1167 			 * before sleeping so that multiple processes do
1168 			 * not try to recycle it.
1169 			 */
1170 			simple_lock(&vp->v_interlock);
1171 			vp->v_usecount--;
1172 			if (vp->v_usecount > 0) {
1173 				simple_unlock(&vp->v_interlock);
1174 				return (error);
1175 			}
1176 			/*
1177 			 * insert at tail of LRU list
1178 			 */
1179 			simple_lock(&vnode_free_list_slock);
1180 			if (vp->v_holdcnt > 0)
1181 				TAILQ_INSERT_TAIL(&vnode_hold_list, vp,
1182 				    v_freelist);
1183 			else
1184 				TAILQ_INSERT_TAIL(&vnode_free_list, vp,
1185 				    v_freelist);
1186 			simple_unlock(&vnode_free_list_slock);
1187 			simple_unlock(&vp->v_interlock);
1188 		}
1189 		return (error);
1190 	}
1191 	simple_unlock(&vp->v_interlock);
1192 	return (0);
1193 }
1194 
1195 /*
1196  * vput(), just unlock and vrele()
1197  */
1198 void
1199 vput(vp)
1200 	struct vnode *vp;
1201 {
1202 	struct proc *p = curproc;	/* XXX */
1203 
1204 #ifdef DIAGNOSTIC
1205 	if (vp == NULL)
1206 		panic("vput: null vp");
1207 #endif
1208 	simple_lock(&vp->v_interlock);
1209 	vp->v_usecount--;
1210 	if (vp->v_usecount > 0) {
1211 		simple_unlock(&vp->v_interlock);
1212 		VOP_UNLOCK(vp, 0);
1213 		return;
1214 	}
1215 #ifdef DIAGNOSTIC
1216 	if (vp->v_usecount < 0 || vp->v_writecount != 0) {
1217 		vprint("vput: bad ref count", vp);
1218 		panic("vput: ref cnt");
1219 	}
1220 #endif
1221 	/*
1222 	 * Insert at tail of LRU list.
1223 	 */
1224 	simple_lock(&vnode_free_list_slock);
1225 	if (vp->v_holdcnt > 0)
1226 		TAILQ_INSERT_TAIL(&vnode_hold_list, vp, v_freelist);
1227 	else
1228 		TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
1229 	simple_unlock(&vnode_free_list_slock);
1230 	if (vp->v_flag & VEXECMAP) {
1231 		uvmexp.execpages -= vp->v_uobj.uo_npages;
1232 		uvmexp.filepages += vp->v_uobj.uo_npages;
1233 	}
1234 	vp->v_flag &= ~(VTEXT|VEXECMAP);
1235 	simple_unlock(&vp->v_interlock);
1236 	VOP_INACTIVE(vp, p);
1237 }
1238 
1239 /*
1240  * Vnode release.
1241  * If count drops to zero, call inactive routine and return to freelist.
1242  */
1243 void
1244 vrele(vp)
1245 	struct vnode *vp;
1246 {
1247 	struct proc *p = curproc;	/* XXX */
1248 
1249 #ifdef DIAGNOSTIC
1250 	if (vp == NULL)
1251 		panic("vrele: null vp");
1252 #endif
1253 	simple_lock(&vp->v_interlock);
1254 	vp->v_usecount--;
1255 	if (vp->v_usecount > 0) {
1256 		simple_unlock(&vp->v_interlock);
1257 		return;
1258 	}
1259 #ifdef DIAGNOSTIC
1260 	if (vp->v_usecount < 0 || vp->v_writecount != 0) {
1261 		vprint("vrele: bad ref count", vp);
1262 		panic("vrele: ref cnt vp %p", vp);
1263 	}
1264 #endif
1265 	/*
1266 	 * Insert at tail of LRU list.
1267 	 */
1268 	simple_lock(&vnode_free_list_slock);
1269 	if (vp->v_holdcnt > 0)
1270 		TAILQ_INSERT_TAIL(&vnode_hold_list, vp, v_freelist);
1271 	else
1272 		TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
1273 	simple_unlock(&vnode_free_list_slock);
1274 	if (vp->v_flag & VEXECMAP) {
1275 		uvmexp.execpages -= vp->v_uobj.uo_npages;
1276 		uvmexp.filepages += vp->v_uobj.uo_npages;
1277 	}
1278 	vp->v_flag &= ~(VTEXT|VEXECMAP);
1279 	if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK) == 0)
1280 		VOP_INACTIVE(vp, p);
1281 }
1282 
1283 #ifdef DIAGNOSTIC
1284 /*
1285  * Page or buffer structure gets a reference.
1286  */
1287 void
1288 vhold(vp)
1289 	struct vnode *vp;
1290 {
1291 
1292 	/*
1293 	 * If it is on the freelist and the hold count is currently
1294 	 * zero, move it to the hold list. The test of the back
1295 	 * pointer and the use reference count of zero is because
1296 	 * it will be removed from a free list by getnewvnode,
1297 	 * but will not have its reference count incremented until
1298 	 * after calling vgone. If the reference count were
1299 	 * incremented first, vgone would (incorrectly) try to
1300 	 * close the previous instance of the underlying object.
1301 	 * So, the back pointer is explicitly set to `0xdeadb' in
1302 	 * getnewvnode after removing it from a freelist to ensure
1303 	 * that we do not try to move it here.
1304 	 */
1305   	simple_lock(&vp->v_interlock);
1306 	if ((vp->v_freelist.tqe_prev != (struct vnode **)0xdeadb) &&
1307 	    vp->v_holdcnt == 0 && vp->v_usecount == 0) {
1308 		simple_lock(&vnode_free_list_slock);
1309 		TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
1310 		TAILQ_INSERT_TAIL(&vnode_hold_list, vp, v_freelist);
1311 		simple_unlock(&vnode_free_list_slock);
1312 	}
1313 	vp->v_holdcnt++;
1314 	simple_unlock(&vp->v_interlock);
1315 }
1316 
1317 /*
1318  * Page or buffer structure frees a reference.
1319  */
1320 void
1321 holdrele(vp)
1322 	struct vnode *vp;
1323 {
1324 
1325 	simple_lock(&vp->v_interlock);
1326 	if (vp->v_holdcnt <= 0)
1327 		panic("holdrele: holdcnt vp %p", vp);
1328 	vp->v_holdcnt--;
1329 
1330 	/*
1331 	 * If it is on the holdlist and the hold count drops to
1332 	 * zero, move it to the free list. The test of the back
1333 	 * pointer and the use reference count of zero is because
1334 	 * it will be removed from a free list by getnewvnode,
1335 	 * but will not have its reference count incremented until
1336 	 * after calling vgone. If the reference count were
1337 	 * incremented first, vgone would (incorrectly) try to
1338 	 * close the previous instance of the underlying object.
1339 	 * So, the back pointer is explicitly set to `0xdeadb' in
1340 	 * getnewvnode after removing it from a freelist to ensure
1341 	 * that we do not try to move it here.
1342 	 */
1343 
1344 	if ((vp->v_freelist.tqe_prev != (struct vnode **)0xdeadb) &&
1345 	    vp->v_holdcnt == 0 && vp->v_usecount == 0) {
1346 		simple_lock(&vnode_free_list_slock);
1347 		TAILQ_REMOVE(&vnode_hold_list, vp, v_freelist);
1348 		TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
1349 		simple_unlock(&vnode_free_list_slock);
1350 	}
1351 	simple_unlock(&vp->v_interlock);
1352 }
1353 
1354 /*
1355  * Vnode reference.
1356  */
1357 void
1358 vref(vp)
1359 	struct vnode *vp;
1360 {
1361 
1362 	simple_lock(&vp->v_interlock);
1363 	if (vp->v_usecount <= 0)
1364 		panic("vref used where vget required, vp %p", vp);
1365 	vp->v_usecount++;
1366 #ifdef DIAGNOSTIC
1367 	if (vp->v_usecount == 0) {
1368 		vprint("vref", vp);
1369 		panic("vref: usecount overflow, vp %p", vp);
1370 	}
1371 #endif
1372 	simple_unlock(&vp->v_interlock);
1373 }
1374 #endif /* DIAGNOSTIC */
1375 
1376 /*
1377  * Remove any vnodes in the vnode table belonging to mount point mp.
1378  *
1379  * If MNT_NOFORCE is specified, there should not be any active ones,
1380  * return error if any are found (nb: this is a user error, not a
1381  * system error). If MNT_FORCE is specified, detach any active vnodes
1382  * that are found.
1383  */
1384 #ifdef DEBUG
1385 int busyprt = 0;	/* print out busy vnodes */
1386 struct ctldebug debug1 = { "busyprt", &busyprt };
1387 #endif
1388 
1389 int
1390 vflush(mp, skipvp, flags)
1391 	struct mount *mp;
1392 	struct vnode *skipvp;
1393 	int flags;
1394 {
1395 	struct proc *p = curproc;	/* XXX */
1396 	struct vnode *vp, *nvp;
1397 	int busy = 0;
1398 
1399 	simple_lock(&mntvnode_slock);
1400 loop:
1401 	for (vp = LIST_FIRST(&mp->mnt_vnodelist); vp; vp = nvp) {
1402 		if (vp->v_mount != mp)
1403 			goto loop;
1404 		nvp = LIST_NEXT(vp, v_mntvnodes);
1405 		/*
1406 		 * Skip over a selected vnode.
1407 		 */
1408 		if (vp == skipvp)
1409 			continue;
1410 		simple_lock(&vp->v_interlock);
1411 		/*
1412 		 * Skip over a vnodes marked VSYSTEM.
1413 		 */
1414 		if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) {
1415 			simple_unlock(&vp->v_interlock);
1416 			continue;
1417 		}
1418 		/*
1419 		 * If WRITECLOSE is set, only flush out regular file
1420 		 * vnodes open for writing.
1421 		 */
1422 		if ((flags & WRITECLOSE) &&
1423 		    (vp->v_writecount == 0 || vp->v_type != VREG)) {
1424 			simple_unlock(&vp->v_interlock);
1425 			continue;
1426 		}
1427 		/*
1428 		 * With v_usecount == 0, all we need to do is clear
1429 		 * out the vnode data structures and we are done.
1430 		 */
1431 		if (vp->v_usecount == 0) {
1432 			simple_unlock(&mntvnode_slock);
1433 			vgonel(vp, p);
1434 			simple_lock(&mntvnode_slock);
1435 			continue;
1436 		}
1437 		/*
1438 		 * If FORCECLOSE is set, forcibly close the vnode.
1439 		 * For block or character devices, revert to an
1440 		 * anonymous device. For all other files, just kill them.
1441 		 */
1442 		if (flags & FORCECLOSE) {
1443 			simple_unlock(&mntvnode_slock);
1444 			if (vp->v_type != VBLK && vp->v_type != VCHR) {
1445 				vgonel(vp, p);
1446 			} else {
1447 				vclean(vp, 0, p);
1448 				vp->v_op = spec_vnodeop_p;
1449 				insmntque(vp, (struct mount *)0);
1450 			}
1451 			simple_lock(&mntvnode_slock);
1452 			continue;
1453 		}
1454 #ifdef DEBUG
1455 		if (busyprt)
1456 			vprint("vflush: busy vnode", vp);
1457 #endif
1458 		simple_unlock(&vp->v_interlock);
1459 		busy++;
1460 	}
1461 	simple_unlock(&mntvnode_slock);
1462 	if (busy)
1463 		return (EBUSY);
1464 	return (0);
1465 }
1466 
1467 /*
1468  * Disassociate the underlying file system from a vnode.
1469  */
1470 void
1471 vclean(vp, flags, p)
1472 	struct vnode *vp;
1473 	int flags;
1474 	struct proc *p;
1475 {
1476 	int active;
1477 
1478 	LOCK_ASSERT(simple_lock_held(&vp->v_interlock));
1479 
1480 	/*
1481 	 * Check to see if the vnode is in use.
1482 	 * If so we have to reference it before we clean it out
1483 	 * so that its count cannot fall to zero and generate a
1484 	 * race against ourselves to recycle it.
1485 	 */
1486 
1487 	if ((active = vp->v_usecount) != 0) {
1488 		vp->v_usecount++;
1489 #ifdef DIAGNOSTIC
1490 		if (vp->v_usecount == 0) {
1491 			vprint("vclean", vp);
1492 			panic("vclean: usecount overflow");
1493 		}
1494 #endif
1495 	}
1496 
1497 	/*
1498 	 * Prevent the vnode from being recycled or
1499 	 * brought into use while we clean it out.
1500 	 */
1501 	if (vp->v_flag & VXLOCK)
1502 		panic("vclean: deadlock, vp %p", vp);
1503 	vp->v_flag |= VXLOCK;
1504 	if (vp->v_flag & VEXECMAP) {
1505 		uvmexp.execpages -= vp->v_uobj.uo_npages;
1506 		uvmexp.filepages += vp->v_uobj.uo_npages;
1507 	}
1508 	vp->v_flag &= ~(VTEXT|VEXECMAP);
1509 
1510 	/*
1511 	 * Even if the count is zero, the VOP_INACTIVE routine may still
1512 	 * have the object locked while it cleans it out. The VOP_LOCK
1513 	 * ensures that the VOP_INACTIVE routine is done with its work.
1514 	 * For active vnodes, it ensures that no other activity can
1515 	 * occur while the underlying object is being cleaned out.
1516 	 */
1517 	VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK);
1518 
1519 	/*
1520 	 * Clean out any cached data associated with the vnode.
1521 	 */
1522 	if (flags & DOCLOSE) {
1523 		vinvalbuf(vp, V_SAVE, NOCRED, p, 0, 0);
1524 		KASSERT((vp->v_flag & VONWORKLST) == 0);
1525 	}
1526 	LOCK_ASSERT(!simple_lock_held(&vp->v_interlock));
1527 
1528 	/*
1529 	 * If purging an active vnode, it must be closed and
1530 	 * deactivated before being reclaimed. Note that the
1531 	 * VOP_INACTIVE will unlock the vnode.
1532 	 */
1533 	if (active) {
1534 		if (flags & DOCLOSE)
1535 			VOP_CLOSE(vp, FNONBLOCK, NOCRED, NULL);
1536 		VOP_INACTIVE(vp, p);
1537 	} else {
1538 		/*
1539 		 * Any other processes trying to obtain this lock must first
1540 		 * wait for VXLOCK to clear, then call the new lock operation.
1541 		 */
1542 		VOP_UNLOCK(vp, 0);
1543 	}
1544 	/*
1545 	 * Reclaim the vnode.
1546 	 */
1547 	if (VOP_RECLAIM(vp, p))
1548 		panic("vclean: cannot reclaim, vp %p", vp);
1549 	if (active) {
1550 		/*
1551 		 * Inline copy of vrele() since VOP_INACTIVE
1552 		 * has already been called.
1553 		 */
1554 		simple_lock(&vp->v_interlock);
1555 		if (--vp->v_usecount <= 0) {
1556 #ifdef DIAGNOSTIC
1557 			if (vp->v_usecount < 0 || vp->v_writecount != 0) {
1558 				vprint("vclean: bad ref count", vp);
1559 				panic("vclean: ref cnt");
1560 			}
1561 #endif
1562 			/*
1563 			 * Insert at tail of LRU list.
1564 			 */
1565 
1566 			simple_unlock(&vp->v_interlock);
1567 			simple_lock(&vnode_free_list_slock);
1568 #ifdef DIAGNOSTIC
1569 			if (vp->v_holdcnt > 0)
1570 				panic("vclean: not clean, vp %p", vp);
1571 #endif
1572 			TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
1573 			simple_unlock(&vnode_free_list_slock);
1574 		} else
1575 			simple_unlock(&vp->v_interlock);
1576 	}
1577 
1578 	KASSERT(vp->v_uobj.uo_npages == 0);
1579 	cache_purge(vp);
1580 
1581 	/*
1582 	 * Done with purge, notify sleepers of the grim news.
1583 	 */
1584 	vp->v_op = dead_vnodeop_p;
1585 	vp->v_tag = VT_NON;
1586 	simple_lock(&vp->v_interlock);
1587 	VN_KNOTE(vp, NOTE_REVOKE);	/* FreeBSD has this in vn_pollgone() */
1588 	vp->v_flag &= ~VXLOCK;
1589 	if (vp->v_flag & VXWANT) {
1590 		vp->v_flag &= ~VXWANT;
1591 		simple_unlock(&vp->v_interlock);
1592 		wakeup((caddr_t)vp);
1593 	} else
1594 		simple_unlock(&vp->v_interlock);
1595 }
1596 
1597 /*
1598  * Recycle an unused vnode to the front of the free list.
1599  * Release the passed interlock if the vnode will be recycled.
1600  */
1601 int
1602 vrecycle(vp, inter_lkp, p)
1603 	struct vnode *vp;
1604 	struct simplelock *inter_lkp;
1605 	struct proc *p;
1606 {
1607 
1608 	simple_lock(&vp->v_interlock);
1609 	if (vp->v_usecount == 0) {
1610 		if (inter_lkp)
1611 			simple_unlock(inter_lkp);
1612 		vgonel(vp, p);
1613 		return (1);
1614 	}
1615 	simple_unlock(&vp->v_interlock);
1616 	return (0);
1617 }
1618 
1619 /*
1620  * Eliminate all activity associated with a vnode
1621  * in preparation for reuse.
1622  */
1623 void
1624 vgone(vp)
1625 	struct vnode *vp;
1626 {
1627 	struct proc *p = curproc;	/* XXX */
1628 
1629 	simple_lock(&vp->v_interlock);
1630 	vgonel(vp, p);
1631 }
1632 
1633 /*
1634  * vgone, with the vp interlock held.
1635  */
1636 void
1637 vgonel(vp, p)
1638 	struct vnode *vp;
1639 	struct proc *p;
1640 {
1641 	struct vnode *vq;
1642 	struct vnode *vx;
1643 
1644 	LOCK_ASSERT(simple_lock_held(&vp->v_interlock));
1645 
1646 	/*
1647 	 * If a vgone (or vclean) is already in progress,
1648 	 * wait until it is done and return.
1649 	 */
1650 
1651 	if (vp->v_flag & VXLOCK) {
1652 		vp->v_flag |= VXWANT;
1653 		ltsleep(vp, PINOD | PNORELOCK, "vgone", 0, &vp->v_interlock);
1654 		return;
1655 	}
1656 
1657 	/*
1658 	 * Clean out the filesystem specific data.
1659 	 */
1660 
1661 	vclean(vp, DOCLOSE, p);
1662 	KASSERT((vp->v_flag & VONWORKLST) == 0);
1663 
1664 	/*
1665 	 * Delete from old mount point vnode list, if on one.
1666 	 */
1667 
1668 	if (vp->v_mount != NULL)
1669 		insmntque(vp, (struct mount *)0);
1670 
1671 	/*
1672 	 * If special device, remove it from special device alias list.
1673 	 * if it is on one.
1674 	 */
1675 
1676 	if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_specinfo != 0) {
1677 		simple_lock(&spechash_slock);
1678 		if (vp->v_hashchain != NULL) {
1679 			if (*vp->v_hashchain == vp) {
1680 				*vp->v_hashchain = vp->v_specnext;
1681 			} else {
1682 				for (vq = *vp->v_hashchain; vq;
1683 							vq = vq->v_specnext) {
1684 					if (vq->v_specnext != vp)
1685 						continue;
1686 					vq->v_specnext = vp->v_specnext;
1687 					break;
1688 				}
1689 				if (vq == NULL)
1690 					panic("missing bdev");
1691 			}
1692 			if (vp->v_flag & VALIASED) {
1693 				vx = NULL;
1694 				for (vq = *vp->v_hashchain; vq;
1695 							vq = vq->v_specnext) {
1696 					if (vq->v_rdev != vp->v_rdev ||
1697 					    vq->v_type != vp->v_type)
1698 						continue;
1699 					if (vx)
1700 						break;
1701 					vx = vq;
1702 				}
1703 				if (vx == NULL)
1704 					panic("missing alias");
1705 				if (vq == NULL)
1706 					vx->v_flag &= ~VALIASED;
1707 				vp->v_flag &= ~VALIASED;
1708 			}
1709 		}
1710 		simple_unlock(&spechash_slock);
1711 		FREE(vp->v_specinfo, M_VNODE);
1712 		vp->v_specinfo = NULL;
1713 	}
1714 
1715 	/*
1716 	 * If it is on the freelist and not already at the head,
1717 	 * move it to the head of the list. The test of the back
1718 	 * pointer and the reference count of zero is because
1719 	 * it will be removed from the free list by getnewvnode,
1720 	 * but will not have its reference count incremented until
1721 	 * after calling vgone. If the reference count were
1722 	 * incremented first, vgone would (incorrectly) try to
1723 	 * close the previous instance of the underlying object.
1724 	 * So, the back pointer is explicitly set to `0xdeadb' in
1725 	 * getnewvnode after removing it from the freelist to ensure
1726 	 * that we do not try to move it here.
1727 	 */
1728 
1729 	if (vp->v_usecount == 0) {
1730 		simple_lock(&vnode_free_list_slock);
1731 		if (vp->v_holdcnt > 0)
1732 			panic("vgonel: not clean, vp %p", vp);
1733 		if (vp->v_freelist.tqe_prev != (struct vnode **)0xdeadb &&
1734 		    TAILQ_FIRST(&vnode_free_list) != vp) {
1735 			TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
1736 			TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
1737 		}
1738 		simple_unlock(&vnode_free_list_slock);
1739 	}
1740 	vp->v_type = VBAD;
1741 }
1742 
1743 /*
1744  * Lookup a vnode by device number.
1745  */
1746 int
1747 vfinddev(dev, type, vpp)
1748 	dev_t dev;
1749 	enum vtype type;
1750 	struct vnode **vpp;
1751 {
1752 	struct vnode *vp;
1753 	int rc = 0;
1754 
1755 	simple_lock(&spechash_slock);
1756 	for (vp = speclisth[SPECHASH(dev)]; vp; vp = vp->v_specnext) {
1757 		if (dev != vp->v_rdev || type != vp->v_type)
1758 			continue;
1759 		*vpp = vp;
1760 		rc = 1;
1761 		break;
1762 	}
1763 	simple_unlock(&spechash_slock);
1764 	return (rc);
1765 }
1766 
1767 /*
1768  * Revoke all the vnodes corresponding to the specified minor number
1769  * range (endpoints inclusive) of the specified major.
1770  */
1771 void
1772 vdevgone(maj, minl, minh, type)
1773 	int maj, minl, minh;
1774 	enum vtype type;
1775 {
1776 	struct vnode *vp;
1777 	int mn;
1778 
1779 	for (mn = minl; mn <= minh; mn++)
1780 		if (vfinddev(makedev(maj, mn), type, &vp))
1781 			VOP_REVOKE(vp, REVOKEALL);
1782 }
1783 
1784 /*
1785  * Calculate the total number of references to a special device.
1786  */
1787 int
1788 vcount(vp)
1789 	struct vnode *vp;
1790 {
1791 	struct vnode *vq, *vnext;
1792 	int count;
1793 
1794 loop:
1795 	if ((vp->v_flag & VALIASED) == 0)
1796 		return (vp->v_usecount);
1797 	simple_lock(&spechash_slock);
1798 	for (count = 0, vq = *vp->v_hashchain; vq; vq = vnext) {
1799 		vnext = vq->v_specnext;
1800 		if (vq->v_rdev != vp->v_rdev || vq->v_type != vp->v_type)
1801 			continue;
1802 		/*
1803 		 * Alias, but not in use, so flush it out.
1804 		 */
1805 		if (vq->v_usecount == 0 && vq != vp &&
1806 		    (vq->v_flag & VXLOCK) == 0) {
1807 			simple_unlock(&spechash_slock);
1808 			vgone(vq);
1809 			goto loop;
1810 		}
1811 		count += vq->v_usecount;
1812 	}
1813 	simple_unlock(&spechash_slock);
1814 	return (count);
1815 }
1816 
1817 /*
1818  * Print out a description of a vnode.
1819  */
1820 static const char * const typename[] =
1821    { "VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD" };
1822 
1823 void
1824 vprint(label, vp)
1825 	char *label;
1826 	struct vnode *vp;
1827 {
1828 	char buf[96];
1829 
1830 	if (label != NULL)
1831 		printf("%s: ", label);
1832 	printf("tag %d type %s, usecount %d, writecount %ld, refcount %ld,",
1833 	    vp->v_tag, typename[vp->v_type], vp->v_usecount, vp->v_writecount,
1834 	    vp->v_holdcnt);
1835 	buf[0] = '\0';
1836 	if (vp->v_flag & VROOT)
1837 		strcat(buf, "|VROOT");
1838 	if (vp->v_flag & VTEXT)
1839 		strcat(buf, "|VTEXT");
1840 	if (vp->v_flag & VEXECMAP)
1841 		strcat(buf, "|VEXECMAP");
1842 	if (vp->v_flag & VSYSTEM)
1843 		strcat(buf, "|VSYSTEM");
1844 	if (vp->v_flag & VXLOCK)
1845 		strcat(buf, "|VXLOCK");
1846 	if (vp->v_flag & VXWANT)
1847 		strcat(buf, "|VXWANT");
1848 	if (vp->v_flag & VBWAIT)
1849 		strcat(buf, "|VBWAIT");
1850 	if (vp->v_flag & VALIASED)
1851 		strcat(buf, "|VALIASED");
1852 	if (buf[0] != '\0')
1853 		printf(" flags (%s)", &buf[1]);
1854 	if (vp->v_data == NULL) {
1855 		printf("\n");
1856 	} else {
1857 		printf("\n\t");
1858 		VOP_PRINT(vp);
1859 	}
1860 }
1861 
1862 #ifdef DEBUG
1863 /*
1864  * List all of the locked vnodes in the system.
1865  * Called when debugging the kernel.
1866  */
1867 void
1868 printlockedvnodes()
1869 {
1870 	struct mount *mp, *nmp;
1871 	struct vnode *vp;
1872 
1873 	printf("Locked vnodes\n");
1874 	simple_lock(&mountlist_slock);
1875 	for (mp = CIRCLEQ_FIRST(&mountlist); mp != (void *)&mountlist;
1876 	     mp = nmp) {
1877 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock)) {
1878 			nmp = CIRCLEQ_NEXT(mp, mnt_list);
1879 			continue;
1880 		}
1881 		LIST_FOREACH(vp, &mp->mnt_vnodelist, v_mntvnodes) {
1882 			if (VOP_ISLOCKED(vp))
1883 				vprint(NULL, vp);
1884 		}
1885 		simple_lock(&mountlist_slock);
1886 		nmp = CIRCLEQ_NEXT(mp, mnt_list);
1887 		vfs_unbusy(mp);
1888 	}
1889 	simple_unlock(&mountlist_slock);
1890 }
1891 #endif
1892 
1893 /*
1894  * Top level filesystem related information gathering.
1895  */
1896 int
1897 vfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
1898 	int *name;
1899 	u_int namelen;
1900 	void *oldp;
1901 	size_t *oldlenp;
1902 	void *newp;
1903 	size_t newlen;
1904 	struct proc *p;
1905 {
1906 #if defined(COMPAT_09) || defined(COMPAT_43) || defined(COMPAT_44)
1907 	struct vfsconf vfc;
1908 	extern const char * const mountcompatnames[];
1909 	extern int nmountcompatnames;
1910 #endif
1911 	struct vfsops *vfsp;
1912 
1913 	/* all sysctl names at this level are at least name and field */
1914 	if (namelen < 2)
1915 		return (ENOTDIR);		/* overloaded */
1916 
1917 	/* Not generic: goes to file system. */
1918 	if (name[0] != VFS_GENERIC) {
1919 		static const struct ctlname vfsnames[VFS_MAXID+1]=CTL_VFS_NAMES;
1920 		const char *vfsname;
1921 
1922 		if (name[0] < 0 || name[0] > VFS_MAXID
1923 		    || (vfsname = vfsnames[name[0]].ctl_name) == NULL)
1924 			return (EOPNOTSUPP);
1925 
1926 		vfsp = vfs_getopsbyname(vfsname);
1927 		if (vfsp == NULL || vfsp->vfs_sysctl == NULL)
1928 			return (EOPNOTSUPP);
1929 		return ((*vfsp->vfs_sysctl)(&name[1], namelen - 1,
1930 		    oldp, oldlenp, newp, newlen, p));
1931 	}
1932 
1933 	/* The rest are generic vfs sysctls. */
1934 	switch (name[1]) {
1935 	case VFS_USERMOUNT:
1936 		return sysctl_int(oldp, oldlenp, newp, newlen, &dovfsusermount);
1937 #if defined(COMPAT_09) || defined(COMPAT_43) || defined(COMPAT_44)
1938 	case VFS_MAXTYPENUM:
1939 		/*
1940 		 * Provided for 4.4BSD-Lite2 compatibility.
1941 		 */
1942 		return (sysctl_rdint(oldp, oldlenp, newp, nmountcompatnames));
1943 	case VFS_CONF:
1944 		/*
1945 		 * Special: a node, next is a file system name.
1946 		 * Provided for 4.4BSD-Lite2 compatibility.
1947 		 */
1948 		if (namelen < 3)
1949 			return (ENOTDIR);	/* overloaded */
1950 		if (name[2] >= nmountcompatnames || name[2] < 0 ||
1951 		    mountcompatnames[name[2]] == NULL)
1952 			return (EOPNOTSUPP);
1953 		vfsp = vfs_getopsbyname(mountcompatnames[name[2]]);
1954 		if (vfsp == NULL)
1955 			return (EOPNOTSUPP);
1956 		vfc.vfc_vfsops = vfsp;
1957 		strncpy(vfc.vfc_name, vfsp->vfs_name, MFSNAMELEN);
1958 		vfc.vfc_typenum = name[2];
1959 		vfc.vfc_refcount = vfsp->vfs_refcount;
1960 		vfc.vfc_flags = 0;
1961 		vfc.vfc_mountroot = vfsp->vfs_mountroot;
1962 		vfc.vfc_next = NULL;
1963 		return (sysctl_rdstruct(oldp, oldlenp, newp, &vfc,
1964 		    sizeof(struct vfsconf)));
1965 #endif
1966 	default:
1967 		break;
1968 	}
1969 	return (EOPNOTSUPP);
1970 }
1971 
1972 int kinfo_vdebug = 1;
1973 int kinfo_vgetfailed;
1974 #define KINFO_VNODESLOP	10
1975 /*
1976  * Dump vnode list (via sysctl).
1977  * Copyout address of vnode followed by vnode.
1978  */
1979 /* ARGSUSED */
1980 int
1981 sysctl_vnode(where, sizep, p)
1982 	char *where;
1983 	size_t *sizep;
1984 	struct proc *p;
1985 {
1986 	struct mount *mp, *nmp;
1987 	struct vnode *nvp, *vp;
1988 	char *bp = where, *savebp;
1989 	char *ewhere;
1990 	int error;
1991 
1992 #define VPTRSZ	sizeof(struct vnode *)
1993 #define VNODESZ	sizeof(struct vnode)
1994 	if (where == NULL) {
1995 		*sizep = (numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ);
1996 		return (0);
1997 	}
1998 	ewhere = where + *sizep;
1999 
2000 	simple_lock(&mountlist_slock);
2001 	for (mp = CIRCLEQ_FIRST(&mountlist); mp != (void *)&mountlist;
2002 	     mp = nmp) {
2003 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_slock)) {
2004 			nmp = CIRCLEQ_NEXT(mp, mnt_list);
2005 			continue;
2006 		}
2007 		savebp = bp;
2008 again:
2009 		simple_lock(&mntvnode_slock);
2010 		for (vp = LIST_FIRST(&mp->mnt_vnodelist);
2011 		     vp != NULL;
2012 		     vp = nvp) {
2013 			/*
2014 			 * Check that the vp is still associated with
2015 			 * this filesystem.  RACE: could have been
2016 			 * recycled onto the same filesystem.
2017 			 */
2018 			if (vp->v_mount != mp) {
2019 				simple_unlock(&mntvnode_slock);
2020 				if (kinfo_vdebug)
2021 					printf("kinfo: vp changed\n");
2022 				bp = savebp;
2023 				goto again;
2024 			}
2025 			nvp = LIST_NEXT(vp, v_mntvnodes);
2026 			if (bp + VPTRSZ + VNODESZ > ewhere) {
2027 				simple_unlock(&mntvnode_slock);
2028 				*sizep = bp - where;
2029 				return (ENOMEM);
2030 			}
2031 			simple_unlock(&mntvnode_slock);
2032 			if ((error = copyout((caddr_t)&vp, bp, VPTRSZ)) ||
2033 			   (error = copyout((caddr_t)vp, bp + VPTRSZ, VNODESZ)))
2034 				return (error);
2035 			bp += VPTRSZ + VNODESZ;
2036 			simple_lock(&mntvnode_slock);
2037 		}
2038 		simple_unlock(&mntvnode_slock);
2039 		simple_lock(&mountlist_slock);
2040 		nmp = CIRCLEQ_NEXT(mp, mnt_list);
2041 		vfs_unbusy(mp);
2042 	}
2043 	simple_unlock(&mountlist_slock);
2044 
2045 	*sizep = bp - where;
2046 	return (0);
2047 }
2048 
2049 /*
2050  * Check to see if a filesystem is mounted on a block device.
2051  */
2052 int
2053 vfs_mountedon(vp)
2054 	struct vnode *vp;
2055 {
2056 	struct vnode *vq;
2057 	int error = 0;
2058 
2059 	if (vp->v_specmountpoint != NULL)
2060 		return (EBUSY);
2061 	if (vp->v_flag & VALIASED) {
2062 		simple_lock(&spechash_slock);
2063 		for (vq = *vp->v_hashchain; vq; vq = vq->v_specnext) {
2064 			if (vq->v_rdev != vp->v_rdev ||
2065 			    vq->v_type != vp->v_type)
2066 				continue;
2067 			if (vq->v_specmountpoint != NULL) {
2068 				error = EBUSY;
2069 				break;
2070 			}
2071 		}
2072 		simple_unlock(&spechash_slock);
2073 	}
2074 	return (error);
2075 }
2076 
2077 /*
2078  * Build hash lists of net addresses and hang them off the mount point.
2079  * Called by ufs_mount() to set up the lists of export addresses.
2080  */
2081 static int
2082 vfs_hang_addrlist(mp, nep, argp)
2083 	struct mount *mp;
2084 	struct netexport *nep;
2085 	struct export_args *argp;
2086 {
2087 	struct netcred *np, *enp;
2088 	struct radix_node_head *rnh;
2089 	int i;
2090 	struct radix_node *rn;
2091 	struct sockaddr *saddr, *smask = 0;
2092 	struct domain *dom;
2093 	int error;
2094 
2095 	if (argp->ex_addrlen == 0) {
2096 		if (mp->mnt_flag & MNT_DEFEXPORTED)
2097 			return (EPERM);
2098 		np = &nep->ne_defexported;
2099 		np->netc_exflags = argp->ex_flags;
2100 		crcvt(&np->netc_anon, &argp->ex_anon);
2101 		np->netc_anon.cr_ref = 1;
2102 		mp->mnt_flag |= MNT_DEFEXPORTED;
2103 		return (0);
2104 	}
2105 
2106 	if (argp->ex_addrlen > MLEN)
2107 		return (EINVAL);
2108 
2109 	i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
2110 	np = (struct netcred *)malloc(i, M_NETADDR, M_WAITOK);
2111 	memset((caddr_t)np, 0, i);
2112 	saddr = (struct sockaddr *)(np + 1);
2113 	error = copyin(argp->ex_addr, (caddr_t)saddr, argp->ex_addrlen);
2114 	if (error)
2115 		goto out;
2116 	if (saddr->sa_len > argp->ex_addrlen)
2117 		saddr->sa_len = argp->ex_addrlen;
2118 	if (argp->ex_masklen) {
2119 		smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen);
2120 		error = copyin(argp->ex_mask, (caddr_t)smask, argp->ex_masklen);
2121 		if (error)
2122 			goto out;
2123 		if (smask->sa_len > argp->ex_masklen)
2124 			smask->sa_len = argp->ex_masklen;
2125 	}
2126 	i = saddr->sa_family;
2127 	if ((rnh = nep->ne_rtable[i]) == 0) {
2128 		/*
2129 		 * Seems silly to initialize every AF when most are not
2130 		 * used, do so on demand here
2131 		 */
2132 		for (dom = domains; dom; dom = dom->dom_next)
2133 			if (dom->dom_family == i && dom->dom_rtattach) {
2134 				dom->dom_rtattach((void **)&nep->ne_rtable[i],
2135 					dom->dom_rtoffset);
2136 				break;
2137 			}
2138 		if ((rnh = nep->ne_rtable[i]) == 0) {
2139 			error = ENOBUFS;
2140 			goto out;
2141 		}
2142 	}
2143 	rn = (*rnh->rnh_addaddr)((caddr_t)saddr, (caddr_t)smask, rnh,
2144 		np->netc_rnodes);
2145 	if (rn == 0 || np != (struct netcred *)rn) { /* already exists */
2146 		if (rn == 0) {
2147 			enp = (struct netcred *)(*rnh->rnh_lookup)(saddr,
2148 				smask, rnh);
2149 			if (enp == 0) {
2150 				error = EPERM;
2151 				goto out;
2152 			}
2153 		} else
2154 			enp = (struct netcred *)rn;
2155 
2156 		if (enp->netc_exflags != argp->ex_flags ||
2157 		    enp->netc_anon.cr_uid != argp->ex_anon.cr_uid ||
2158 		    enp->netc_anon.cr_gid != argp->ex_anon.cr_gid ||
2159 		    enp->netc_anon.cr_ngroups !=
2160 		    			(uint32_t) argp->ex_anon.cr_ngroups ||
2161 		    memcmp(&enp->netc_anon.cr_groups, &argp->ex_anon.cr_groups,
2162 			enp->netc_anon.cr_ngroups))
2163 				error = EPERM;
2164 		else
2165 			error = 0;
2166 		goto out;
2167 	}
2168 	np->netc_exflags = argp->ex_flags;
2169 	crcvt(&np->netc_anon, &argp->ex_anon);
2170 	np->netc_anon.cr_ref = 1;
2171 	return (0);
2172 out:
2173 	free(np, M_NETADDR);
2174 	return (error);
2175 }
2176 
2177 /* ARGSUSED */
2178 static int
2179 vfs_free_netcred(rn, w)
2180 	struct radix_node *rn;
2181 	void *w;
2182 {
2183 	struct radix_node_head *rnh = (struct radix_node_head *)w;
2184 
2185 	(*rnh->rnh_deladdr)(rn->rn_key, rn->rn_mask, rnh);
2186 	free((caddr_t)rn, M_NETADDR);
2187 	return (0);
2188 }
2189 
2190 /*
2191  * Free the net address hash lists that are hanging off the mount points.
2192  */
2193 static void
2194 vfs_free_addrlist(nep)
2195 	struct netexport *nep;
2196 {
2197 	int i;
2198 	struct radix_node_head *rnh;
2199 
2200 	for (i = 0; i <= AF_MAX; i++)
2201 		if ((rnh = nep->ne_rtable[i]) != NULL) {
2202 			(*rnh->rnh_walktree)(rnh, vfs_free_netcred, rnh);
2203 			free((caddr_t)rnh, M_RTABLE);
2204 			nep->ne_rtable[i] = 0;
2205 		}
2206 }
2207 
2208 int
2209 vfs_export(mp, nep, argp)
2210 	struct mount *mp;
2211 	struct netexport *nep;
2212 	struct export_args *argp;
2213 {
2214 	int error;
2215 
2216 	if (argp->ex_flags & MNT_DELEXPORT) {
2217 		if (mp->mnt_flag & MNT_EXPUBLIC) {
2218 			vfs_setpublicfs(NULL, NULL, NULL);
2219 			mp->mnt_flag &= ~MNT_EXPUBLIC;
2220 		}
2221 		vfs_free_addrlist(nep);
2222 		mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
2223 	}
2224 	if (argp->ex_flags & MNT_EXPORTED) {
2225 		if (argp->ex_flags & MNT_EXPUBLIC) {
2226 			if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
2227 				return (error);
2228 			mp->mnt_flag |= MNT_EXPUBLIC;
2229 		}
2230 		if ((error = vfs_hang_addrlist(mp, nep, argp)) != 0)
2231 			return (error);
2232 		mp->mnt_flag |= MNT_EXPORTED;
2233 	}
2234 	return (0);
2235 }
2236 
2237 /*
2238  * Set the publicly exported filesystem (WebNFS). Currently, only
2239  * one public filesystem is possible in the spec (RFC 2054 and 2055)
2240  */
2241 int
2242 vfs_setpublicfs(mp, nep, argp)
2243 	struct mount *mp;
2244 	struct netexport *nep;
2245 	struct export_args *argp;
2246 {
2247 	int error;
2248 	struct vnode *rvp;
2249 	char *cp;
2250 
2251 	/*
2252 	 * mp == NULL -> invalidate the current info, the FS is
2253 	 * no longer exported. May be called from either vfs_export
2254 	 * or unmount, so check if it hasn't already been done.
2255 	 */
2256 	if (mp == NULL) {
2257 		if (nfs_pub.np_valid) {
2258 			nfs_pub.np_valid = 0;
2259 			if (nfs_pub.np_index != NULL) {
2260 				FREE(nfs_pub.np_index, M_TEMP);
2261 				nfs_pub.np_index = NULL;
2262 			}
2263 		}
2264 		return (0);
2265 	}
2266 
2267 	/*
2268 	 * Only one allowed at a time.
2269 	 */
2270 	if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
2271 		return (EBUSY);
2272 
2273 	/*
2274 	 * Get real filehandle for root of exported FS.
2275 	 */
2276 	memset((caddr_t)&nfs_pub.np_handle, 0, sizeof(nfs_pub.np_handle));
2277 	nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
2278 
2279 	if ((error = VFS_ROOT(mp, &rvp)))
2280 		return (error);
2281 
2282 	if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
2283 		return (error);
2284 
2285 	vput(rvp);
2286 
2287 	/*
2288 	 * If an indexfile was specified, pull it in.
2289 	 */
2290 	if (argp->ex_indexfile != NULL) {
2291 		MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
2292 		    M_WAITOK);
2293 		error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
2294 		    MAXNAMLEN, (size_t *)0);
2295 		if (!error) {
2296 			/*
2297 			 * Check for illegal filenames.
2298 			 */
2299 			for (cp = nfs_pub.np_index; *cp; cp++) {
2300 				if (*cp == '/') {
2301 					error = EINVAL;
2302 					break;
2303 				}
2304 			}
2305 		}
2306 		if (error) {
2307 			FREE(nfs_pub.np_index, M_TEMP);
2308 			return (error);
2309 		}
2310 	}
2311 
2312 	nfs_pub.np_mount = mp;
2313 	nfs_pub.np_valid = 1;
2314 	return (0);
2315 }
2316 
2317 struct netcred *
2318 vfs_export_lookup(mp, nep, nam)
2319 	struct mount *mp;
2320 	struct netexport *nep;
2321 	struct mbuf *nam;
2322 {
2323 	struct netcred *np;
2324 	struct radix_node_head *rnh;
2325 	struct sockaddr *saddr;
2326 
2327 	np = NULL;
2328 	if (mp->mnt_flag & MNT_EXPORTED) {
2329 		/*
2330 		 * Lookup in the export list first.
2331 		 */
2332 		if (nam != NULL) {
2333 			saddr = mtod(nam, struct sockaddr *);
2334 			rnh = nep->ne_rtable[saddr->sa_family];
2335 			if (rnh != NULL) {
2336 				np = (struct netcred *)
2337 					(*rnh->rnh_matchaddr)((caddr_t)saddr,
2338 							      rnh);
2339 				if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
2340 					np = NULL;
2341 			}
2342 		}
2343 		/*
2344 		 * If no address match, use the default if it exists.
2345 		 */
2346 		if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
2347 			np = &nep->ne_defexported;
2348 	}
2349 	return (np);
2350 }
2351 
2352 /*
2353  * Do the usual access checking.
2354  * file_mode, uid and gid are from the vnode in question,
2355  * while acc_mode and cred are from the VOP_ACCESS parameter list
2356  */
2357 int
2358 vaccess(type, file_mode, uid, gid, acc_mode, cred)
2359 	enum vtype type;
2360 	mode_t file_mode;
2361 	uid_t uid;
2362 	gid_t gid;
2363 	mode_t acc_mode;
2364 	struct ucred *cred;
2365 {
2366 	mode_t mask;
2367 
2368 	/*
2369 	 * Super-user always gets read/write access, but execute access depends
2370 	 * on at least one execute bit being set.
2371 	 */
2372 	if (cred->cr_uid == 0) {
2373 		if ((acc_mode & VEXEC) && type != VDIR &&
2374 		    (file_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)
2375 			return (EACCES);
2376 		return (0);
2377 	}
2378 
2379 	mask = 0;
2380 
2381 	/* Otherwise, check the owner. */
2382 	if (cred->cr_uid == uid) {
2383 		if (acc_mode & VEXEC)
2384 			mask |= S_IXUSR;
2385 		if (acc_mode & VREAD)
2386 			mask |= S_IRUSR;
2387 		if (acc_mode & VWRITE)
2388 			mask |= S_IWUSR;
2389 		return ((file_mode & mask) == mask ? 0 : EACCES);
2390 	}
2391 
2392 	/* Otherwise, check the groups. */
2393 	if (cred->cr_gid == gid || groupmember(gid, cred)) {
2394 		if (acc_mode & VEXEC)
2395 			mask |= S_IXGRP;
2396 		if (acc_mode & VREAD)
2397 			mask |= S_IRGRP;
2398 		if (acc_mode & VWRITE)
2399 			mask |= S_IWGRP;
2400 		return ((file_mode & mask) == mask ? 0 : EACCES);
2401 	}
2402 
2403 	/* Otherwise, check everyone else. */
2404 	if (acc_mode & VEXEC)
2405 		mask |= S_IXOTH;
2406 	if (acc_mode & VREAD)
2407 		mask |= S_IROTH;
2408 	if (acc_mode & VWRITE)
2409 		mask |= S_IWOTH;
2410 	return ((file_mode & mask) == mask ? 0 : EACCES);
2411 }
2412 
2413 /*
2414  * Unmount all file systems.
2415  * We traverse the list in reverse order under the assumption that doing so
2416  * will avoid needing to worry about dependencies.
2417  */
2418 void
2419 vfs_unmountall(p)
2420 	struct proc *p;
2421 {
2422 	struct mount *mp, *nmp;
2423 	int allerror, error;
2424 
2425 	for (allerror = 0,
2426 	     mp = mountlist.cqh_last; mp != (void *)&mountlist; mp = nmp) {
2427 		nmp = mp->mnt_list.cqe_prev;
2428 #ifdef DEBUG
2429 		printf("unmounting %s (%s)...\n",
2430 		    mp->mnt_stat.f_mntonname, mp->mnt_stat.f_mntfromname);
2431 #endif
2432 		/*
2433 		 * XXX Freeze syncer.  Must do this before locking the
2434 		 * mount point.  See dounmount() for details.
2435 		 */
2436 		lockmgr(&syncer_lock, LK_EXCLUSIVE, NULL);
2437 		if (vfs_busy(mp, 0, 0)) {
2438 			lockmgr(&syncer_lock, LK_RELEASE, NULL);
2439 			continue;
2440 		}
2441 		if ((error = dounmount(mp, MNT_FORCE, p)) != 0) {
2442 			printf("unmount of %s failed with error %d\n",
2443 			    mp->mnt_stat.f_mntonname, error);
2444 			allerror = 1;
2445 		}
2446 	}
2447 	if (allerror)
2448 		printf("WARNING: some file systems would not unmount\n");
2449 }
2450 
2451 /*
2452  * Sync and unmount file systems before shutting down.
2453  */
2454 void
2455 vfs_shutdown()
2456 {
2457 	struct buf *bp;
2458 	int iter, nbusy, nbusy_prev = 0, dcount, s;
2459 	struct proc *p = curproc;
2460 
2461 	/* XXX we're certainly not running in proc0's context! */
2462 	if (p == NULL)
2463 		p = &proc0;
2464 
2465 	printf("syncing disks... ");
2466 
2467 	/* remove user process from run queue */
2468 	suspendsched();
2469 	(void) spl0();
2470 
2471 	/* avoid coming back this way again if we panic. */
2472 	doing_shutdown = 1;
2473 
2474 	sys_sync(p, NULL, NULL);
2475 
2476 	/* Wait for sync to finish. */
2477 	dcount = 10000;
2478 	for (iter = 0; iter < 20;) {
2479 		nbusy = 0;
2480 		for (bp = &buf[nbuf]; --bp >= buf; ) {
2481 			if ((bp->b_flags & (B_BUSY|B_INVAL|B_READ)) == B_BUSY)
2482 				nbusy++;
2483 			/*
2484 			 * With soft updates, some buffers that are
2485 			 * written will be remarked as dirty until other
2486 			 * buffers are written.
2487 			 */
2488 			if (bp->b_vp && bp->b_vp->v_mount
2489 			    && (bp->b_vp->v_mount->mnt_flag & MNT_SOFTDEP)
2490 			    && (bp->b_flags & B_DELWRI)) {
2491 				s = splbio();
2492 				bremfree(bp);
2493 				bp->b_flags |= B_BUSY;
2494 				splx(s);
2495 				nbusy++;
2496 				bawrite(bp);
2497 				if (dcount-- <= 0) {
2498 					printf("softdep ");
2499 					goto fail;
2500 				}
2501 			}
2502 		}
2503 		if (nbusy == 0)
2504 			break;
2505 		if (nbusy_prev == 0)
2506 			nbusy_prev = nbusy;
2507 		printf("%d ", nbusy);
2508 		tsleep(&nbusy, PRIBIO, "bflush",
2509 		    (iter == 0) ? 1 : hz / 25 * iter);
2510 		if (nbusy >= nbusy_prev) /* we didn't flush anything */
2511 			iter++;
2512 		else
2513 			nbusy_prev = nbusy;
2514 	}
2515 	if (nbusy) {
2516 fail:
2517 #if defined(DEBUG) || defined(DEBUG_HALT_BUSY)
2518 		printf("giving up\nPrinting vnodes for busy buffers\n");
2519 		for (bp = &buf[nbuf]; --bp >= buf; )
2520 			if ((bp->b_flags & (B_BUSY|B_INVAL|B_READ)) == B_BUSY)
2521 				vprint(NULL, bp->b_vp);
2522 
2523 #if defined(DDB) && defined(DEBUG_HALT_BUSY)
2524 		Debugger();
2525 #endif
2526 
2527 #else  /* defined(DEBUG) || defined(DEBUG_HALT_BUSY) */
2528 		printf("giving up\n");
2529 #endif /* defined(DEBUG) || defined(DEBUG_HALT_BUSY) */
2530 		return;
2531 	} else
2532 		printf("done\n");
2533 
2534 	/*
2535 	 * If we've panic'd, don't make the situation potentially
2536 	 * worse by unmounting the file systems.
2537 	 */
2538 	if (panicstr != NULL)
2539 		return;
2540 
2541 	/* Release inodes held by texts before update. */
2542 #ifdef notdef
2543 	vnshutdown();
2544 #endif
2545 	/* Unmount file systems. */
2546 	vfs_unmountall(p);
2547 }
2548 
2549 /*
2550  * Mount the root file system.  If the operator didn't specify a
2551  * file system to use, try all possible file systems until one
2552  * succeeds.
2553  */
2554 int
2555 vfs_mountroot()
2556 {
2557 	struct vfsops *v;
2558 
2559 	if (root_device == NULL)
2560 		panic("vfs_mountroot: root device unknown");
2561 
2562 	switch (root_device->dv_class) {
2563 	case DV_IFNET:
2564 		if (rootdev != NODEV)
2565 			panic("vfs_mountroot: rootdev set for DV_IFNET "
2566 			    "(0x%08x -> %d,%d)", rootdev,
2567 			    major(rootdev), minor(rootdev));
2568 		break;
2569 
2570 	case DV_DISK:
2571 		if (rootdev == NODEV)
2572 			panic("vfs_mountroot: rootdev not set for DV_DISK");
2573 		break;
2574 
2575 	default:
2576 		printf("%s: inappropriate for root file system\n",
2577 		    root_device->dv_xname);
2578 		return (ENODEV);
2579 	}
2580 
2581 	/*
2582 	 * If user specified a file system, use it.
2583 	 */
2584 	if (mountroot != NULL)
2585 		return ((*mountroot)());
2586 
2587 	/*
2588 	 * Try each file system currently configured into the kernel.
2589 	 */
2590 	for (v = LIST_FIRST(&vfs_list); v != NULL; v = LIST_NEXT(v, vfs_list)) {
2591 		if (v->vfs_mountroot == NULL)
2592 			continue;
2593 #ifdef DEBUG
2594 		printf("mountroot: trying %s...\n", v->vfs_name);
2595 #endif
2596 		if ((*v->vfs_mountroot)() == 0) {
2597 			printf("root file system type: %s\n", v->vfs_name);
2598 			break;
2599 		}
2600 	}
2601 
2602 	if (v == NULL) {
2603 		printf("no file system for %s", root_device->dv_xname);
2604 		if (root_device->dv_class == DV_DISK)
2605 			printf(" (dev 0x%x)", rootdev);
2606 		printf("\n");
2607 		return (EFTYPE);
2608 	}
2609 	return (0);
2610 }
2611 
2612 /*
2613  * Given a file system name, look up the vfsops for that
2614  * file system, or return NULL if file system isn't present
2615  * in the kernel.
2616  */
2617 struct vfsops *
2618 vfs_getopsbyname(name)
2619 	const char *name;
2620 {
2621 	struct vfsops *v;
2622 
2623 	for (v = LIST_FIRST(&vfs_list); v != NULL; v = LIST_NEXT(v, vfs_list)) {
2624 		if (strcmp(v->vfs_name, name) == 0)
2625 			break;
2626 	}
2627 
2628 	return (v);
2629 }
2630 
2631 /*
2632  * Establish a file system and initialize it.
2633  */
2634 int
2635 vfs_attach(vfs)
2636 	struct vfsops *vfs;
2637 {
2638 	struct vfsops *v;
2639 	int error = 0;
2640 
2641 
2642 	/*
2643 	 * Make sure this file system doesn't already exist.
2644 	 */
2645 	LIST_FOREACH(v, &vfs_list, vfs_list) {
2646 		if (strcmp(vfs->vfs_name, v->vfs_name) == 0) {
2647 			error = EEXIST;
2648 			goto out;
2649 		}
2650 	}
2651 
2652 	/*
2653 	 * Initialize the vnode operations for this file system.
2654 	 */
2655 	vfs_opv_init(vfs->vfs_opv_descs);
2656 
2657 	/*
2658 	 * Now initialize the file system itself.
2659 	 */
2660 	(*vfs->vfs_init)();
2661 
2662 	/*
2663 	 * ...and link it into the kernel's list.
2664 	 */
2665 	LIST_INSERT_HEAD(&vfs_list, vfs, vfs_list);
2666 
2667 	/*
2668 	 * Sanity: make sure the reference count is 0.
2669 	 */
2670 	vfs->vfs_refcount = 0;
2671 
2672  out:
2673 	return (error);
2674 }
2675 
2676 /*
2677  * Remove a file system from the kernel.
2678  */
2679 int
2680 vfs_detach(vfs)
2681 	struct vfsops *vfs;
2682 {
2683 	struct vfsops *v;
2684 
2685 	/*
2686 	 * Make sure no one is using the filesystem.
2687 	 */
2688 	if (vfs->vfs_refcount != 0)
2689 		return (EBUSY);
2690 
2691 	/*
2692 	 * ...and remove it from the kernel's list.
2693 	 */
2694 	LIST_FOREACH(v, &vfs_list, vfs_list) {
2695 		if (v == vfs) {
2696 			LIST_REMOVE(v, vfs_list);
2697 			break;
2698 		}
2699 	}
2700 
2701 	if (v == NULL)
2702 		return (ESRCH);
2703 
2704 	/*
2705 	 * Now run the file system-specific cleanups.
2706 	 */
2707 	(*vfs->vfs_done)();
2708 
2709 	/*
2710 	 * Free the vnode operations vector.
2711 	 */
2712 	vfs_opv_free(vfs->vfs_opv_descs);
2713 	return (0);
2714 }
2715 
2716 void
2717 vfs_reinit(void)
2718 {
2719 	struct vfsops *vfs;
2720 
2721 	LIST_FOREACH(vfs, &vfs_list, vfs_list) {
2722 		if (vfs->vfs_reinit) {
2723 			(*vfs->vfs_reinit)();
2724 		}
2725 	}
2726 }
2727 
2728 #ifdef DDB
2729 const char buf_flagbits[] =
2730 	"\20\1AGE\2NEEDCOMMIT\3ASYNC\4BAD\5BUSY\6SCANNED\7CALL\10DELWRI"
2731 	"\11DIRTY\12DONE\13EINTR\14ERROR\15GATHERED\16INVAL\17LOCKED\20NOCACHE"
2732 	"\21ORDERED\22CACHE\23PHYS\24RAW\25READ\26TAPE\30WANTED"
2733 	"\32XXX\33VFLUSH";
2734 
2735 void
2736 vfs_buf_print(bp, full, pr)
2737 	struct buf *bp;
2738 	int full;
2739 	void (*pr) __P((const char *, ...));
2740 {
2741 	char buf[1024];
2742 
2743 	(*pr)("  vp %p lblkno 0x%x blkno 0x%x dev 0x%x\n",
2744 		  bp->b_vp, bp->b_lblkno, bp->b_blkno, bp->b_dev);
2745 
2746 	bitmask_snprintf(bp->b_flags, buf_flagbits, buf, sizeof(buf));
2747 	(*pr)("  error %d flags 0x%s\n", bp->b_error, buf);
2748 
2749 	(*pr)("  bufsize 0x%lx bcount 0x%lx resid 0x%lx\n",
2750 		  bp->b_bufsize, bp->b_bcount, bp->b_resid);
2751 	(*pr)("  data %p saveaddr %p dep %p\n",
2752 		  bp->b_data, bp->b_saveaddr, LIST_FIRST(&bp->b_dep));
2753 	(*pr)("  iodone %p\n", bp->b_iodone);
2754 }
2755 
2756 
2757 const char vnode_flagbits[] =
2758 	"\20\1ROOT\2TEXT\3SYSTEM\4ISTTY\5EXECMAP"
2759 	"\11XLOCK\12XWANT\13BWAIT\14ALIASED"
2760 	"\15DIROP\16LAYER\17ONWORKLIST\20DIRTY";
2761 
2762 const char *vnode_types[] = {
2763 	"VNON",
2764 	"VREG",
2765 	"VDIR",
2766 	"VBLK",
2767 	"VCHR",
2768 	"VLNK",
2769 	"VSOCK",
2770 	"VFIFO",
2771 	"VBAD",
2772 };
2773 
2774 const char *vnode_tags[] = {
2775 	"VT_NON",
2776 	"VT_UFS",
2777 	"VT_NFS",
2778 	"VT_MFS",
2779 	"VT_MSDOSFS",
2780 	"VT_LFS",
2781 	"VT_LOFS",
2782 	"VT_FDESC",
2783 	"VT_PORTAL",
2784 	"VT_NULL",
2785 	"VT_UMAP",
2786 	"VT_KERNFS",
2787 	"VT_PROCFS",
2788 	"VT_AFS",
2789 	"VT_ISOFS",
2790 	"VT_UNION",
2791 	"VT_ADOSFS",
2792 	"VT_EXT2FS",
2793 	"VT_CODA",
2794 	"VT_FILECORE",
2795 	"VT_NTFS",
2796 	"VT_VFS",
2797 	"VT_OVERLAY"
2798 };
2799 
2800 void
2801 vfs_vnode_print(vp, full, pr)
2802 	struct vnode *vp;
2803 	int full;
2804 	void (*pr) __P((const char *, ...));
2805 {
2806 	char buf[256];
2807 	const char *vtype, *vtag;
2808 
2809 	uvm_object_printit(&vp->v_uobj, full, pr);
2810 	bitmask_snprintf(vp->v_flag, vnode_flagbits, buf, sizeof(buf));
2811 	(*pr)("\nVNODE flags %s\n", buf);
2812 	(*pr)("mp %p numoutput %d size 0x%llx\n",
2813 	      vp->v_mount, vp->v_numoutput, vp->v_size);
2814 
2815 	(*pr)("data %p usecount %d writecount %ld holdcnt %ld numoutput %d\n",
2816 	      vp->v_data, vp->v_usecount, vp->v_writecount,
2817 	      vp->v_holdcnt, vp->v_numoutput);
2818 
2819 	vtype = (vp->v_type >= 0 &&
2820 		 vp->v_type < sizeof(vnode_types) / sizeof(vnode_types[0])) ?
2821 		vnode_types[vp->v_type] : "UNKNOWN";
2822 	vtag = (vp->v_tag >= 0 &&
2823 		vp->v_tag < sizeof(vnode_tags) / sizeof(vnode_tags[0])) ?
2824 		vnode_tags[vp->v_tag] : "UNKNOWN";
2825 
2826 	(*pr)("type %s(%d) tag %s(%d) id 0x%lx mount %p typedata %p\n",
2827 	      vtype, vp->v_type, vtag, vp->v_tag,
2828 	      vp->v_id, vp->v_mount, vp->v_mountedhere);
2829 
2830 	if (full) {
2831 		struct buf *bp;
2832 
2833 		(*pr)("clean bufs:\n");
2834 		LIST_FOREACH(bp, &vp->v_cleanblkhd, b_vnbufs) {
2835 			(*pr)(" bp %p\n", bp);
2836 			vfs_buf_print(bp, full, pr);
2837 		}
2838 
2839 		(*pr)("dirty bufs:\n");
2840 		LIST_FOREACH(bp, &vp->v_dirtyblkhd, b_vnbufs) {
2841 			(*pr)(" bp %p\n", bp);
2842 			vfs_buf_print(bp, full, pr);
2843 		}
2844 	}
2845 }
2846 #endif
2847