xref: /dflybsd-src/sys/kern/vfs_subr.c (revision ece77bbaa23bf75f3b7bb9d110e2a795e3112878)
1 /*
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)vfs_subr.c	8.31 (Berkeley) 5/26/95
39  * $FreeBSD: src/sys/kern/vfs_subr.c,v 1.249.2.30 2003/04/04 20:35:57 tegge Exp $
40  * $DragonFly: src/sys/kern/vfs_subr.c,v 1.25 2004/02/10 07:34:42 dillon Exp $
41  */
42 
43 /*
44  * External virtual filesystem routines
45  */
46 #include "opt_ddb.h"
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/buf.h>
51 #include <sys/conf.h>
52 #include <sys/dirent.h>
53 #include <sys/domain.h>
54 #include <sys/eventhandler.h>
55 #include <sys/fcntl.h>
56 #include <sys/kernel.h>
57 #include <sys/kthread.h>
58 #include <sys/malloc.h>
59 #include <sys/mbuf.h>
60 #include <sys/mount.h>
61 #include <sys/proc.h>
62 #include <sys/namei.h>
63 #include <sys/reboot.h>
64 #include <sys/socket.h>
65 #include <sys/stat.h>
66 #include <sys/sysctl.h>
67 #include <sys/syslog.h>
68 #include <sys/vmmeter.h>
69 #include <sys/vnode.h>
70 
71 #include <machine/limits.h>
72 
73 #include <vm/vm.h>
74 #include <vm/vm_object.h>
75 #include <vm/vm_extern.h>
76 #include <vm/vm_kern.h>
77 #include <vm/pmap.h>
78 #include <vm/vm_map.h>
79 #include <vm/vm_page.h>
80 #include <vm/vm_pager.h>
81 #include <vm/vnode_pager.h>
82 #include <vm/vm_zone.h>
83 
84 #include <sys/buf2.h>
85 #include <sys/thread2.h>
86 
87 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
88 
89 static void	insmntque (struct vnode *vp, struct mount *mp);
90 static void	vclean (struct vnode *vp, int flags, struct thread *td);
91 static unsigned long	numvnodes;
92 static void	vlruvp(struct vnode *vp);
93 SYSCTL_INT(_debug, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, "");
94 
95 enum vtype iftovt_tab[16] = {
96 	VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
97 	VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
98 };
99 int vttoif_tab[9] = {
100 	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
101 	S_IFSOCK, S_IFIFO, S_IFMT,
102 };
103 
104 static TAILQ_HEAD(freelst, vnode) vnode_free_list;	/* vnode free list */
105 
106 static u_long wantfreevnodes = 25;
107 SYSCTL_INT(_debug, OID_AUTO, wantfreevnodes, CTLFLAG_RW, &wantfreevnodes, 0, "");
108 static u_long freevnodes = 0;
109 SYSCTL_INT(_debug, OID_AUTO, freevnodes, CTLFLAG_RD, &freevnodes, 0, "");
110 
111 static int reassignbufcalls;
112 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls, 0, "");
113 static int reassignbufloops;
114 SYSCTL_INT(_vfs, OID_AUTO, reassignbufloops, CTLFLAG_RW, &reassignbufloops, 0, "");
115 static int reassignbufsortgood;
116 SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortgood, CTLFLAG_RW, &reassignbufsortgood, 0, "");
117 static int reassignbufsortbad;
118 SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortbad, CTLFLAG_RW, &reassignbufsortbad, 0, "");
119 static int reassignbufmethod = 1;
120 SYSCTL_INT(_vfs, OID_AUTO, reassignbufmethod, CTLFLAG_RW, &reassignbufmethod, 0, "");
121 
122 #ifdef ENABLE_VFS_IOOPT
123 int vfs_ioopt = 0;
124 SYSCTL_INT(_vfs, OID_AUTO, ioopt, CTLFLAG_RW, &vfs_ioopt, 0, "");
125 #endif
126 
127 struct mntlist mountlist = TAILQ_HEAD_INITIALIZER(mountlist); /* mounted fs */
128 struct lwkt_token mountlist_token;
129 struct lwkt_token mntvnode_token;
130 int	nfs_mount_type = -1;
131 static struct lwkt_token mntid_token;
132 static struct lwkt_token vnode_free_list_token;
133 static struct lwkt_token spechash_token;
134 struct nfs_public nfs_pub;	/* publicly exported FS */
135 static vm_zone_t vnode_zone;
136 
137 /*
138  * The workitem queue.
139  */
140 #define SYNCER_MAXDELAY		32
141 static int syncer_maxdelay = SYNCER_MAXDELAY;	/* maximum delay time */
142 time_t syncdelay = 30;		/* max time to delay syncing data */
143 SYSCTL_INT(_kern, OID_AUTO, syncdelay, CTLFLAG_RW, &syncdelay, 0,
144 	"VFS data synchronization delay");
145 time_t filedelay = 30;		/* time to delay syncing files */
146 SYSCTL_INT(_kern, OID_AUTO, filedelay, CTLFLAG_RW, &filedelay, 0,
147 	"File synchronization delay");
148 time_t dirdelay = 29;		/* time to delay syncing directories */
149 SYSCTL_INT(_kern, OID_AUTO, dirdelay, CTLFLAG_RW, &dirdelay, 0,
150 	"Directory synchronization delay");
151 time_t metadelay = 28;		/* time to delay syncing metadata */
152 SYSCTL_INT(_kern, OID_AUTO, metadelay, CTLFLAG_RW, &metadelay, 0,
153 	"VFS metadata synchronization delay");
154 static int rushjob;			/* number of slots to run ASAP */
155 static int stat_rush_requests;	/* number of times I/O speeded up */
156 SYSCTL_INT(_debug, OID_AUTO, rush_requests, CTLFLAG_RW, &stat_rush_requests, 0, "");
157 
158 static int syncer_delayno = 0;
159 static long syncer_mask;
160 LIST_HEAD(synclist, vnode);
161 static struct synclist *syncer_workitem_pending;
162 
163 int desiredvnodes;
164 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
165     &desiredvnodes, 0, "Maximum number of vnodes");
166 static int minvnodes;
167 SYSCTL_INT(_kern, OID_AUTO, minvnodes, CTLFLAG_RW,
168     &minvnodes, 0, "Minimum number of vnodes");
169 static int vnlru_nowhere = 0;
170 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW, &vnlru_nowhere, 0,
171     "Number of times the vnlru process ran without success");
172 
173 static void	vfs_free_addrlist (struct netexport *nep);
174 static int	vfs_free_netcred (struct radix_node *rn, void *w);
175 static int	vfs_hang_addrlist (struct mount *mp, struct netexport *nep,
176 				       struct export_args *argp);
177 
178 /*
179  * Initialize the vnode management data structures.
180  */
181 void
182 vntblinit()
183 {
184 
185 	/*
186 	 * Desired vnodes is a result of the physical page count
187 	 * and the size of kernel's heap.  It scales in proportion
188 	 * to the amount of available physical memory.  This can
189 	 * cause trouble on 64-bit and large memory platforms.
190 	 */
191 	/* desiredvnodes = maxproc + vmstats.v_page_count / 4; */
192 	desiredvnodes =
193 		min(maxproc + vmstats.v_page_count /4,
194 		    2 * (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
195 		    (5 * (sizeof(struct vm_object) + sizeof(struct vnode))));
196 
197 	minvnodes = desiredvnodes / 4;
198 	lwkt_inittoken(&mountlist_token);
199 	lwkt_inittoken(&mntvnode_token);
200 	lwkt_inittoken(&mntid_token);
201 	lwkt_inittoken(&spechash_token);
202 	TAILQ_INIT(&vnode_free_list);
203 	lwkt_inittoken(&vnode_free_list_token);
204 	vnode_zone = zinit("VNODE", sizeof (struct vnode), 0, 0, 5);
205 	/*
206 	 * Initialize the filesystem syncer.
207 	 */
208 	syncer_workitem_pending = hashinit(syncer_maxdelay, M_VNODE,
209 		&syncer_mask);
210 	syncer_maxdelay = syncer_mask + 1;
211 }
212 
213 /*
214  * Mark a mount point as busy. Used to synchronize access and to delay
215  * unmounting. Interlock is not released on failure.
216  */
217 int
218 vfs_busy(struct mount *mp, int flags, struct lwkt_token *interlkp,
219 	struct thread *td)
220 {
221 	int lkflags;
222 
223 	if (mp->mnt_kern_flag & MNTK_UNMOUNT) {
224 		if (flags & LK_NOWAIT)
225 			return (ENOENT);
226 		mp->mnt_kern_flag |= MNTK_MWAIT;
227 		if (interlkp) {
228 			lwkt_reltoken(interlkp);
229 		}
230 		/*
231 		 * Since all busy locks are shared except the exclusive
232 		 * lock granted when unmounting, the only place that a
233 		 * wakeup needs to be done is at the release of the
234 		 * exclusive lock at the end of dounmount.
235 		 */
236 		tsleep((caddr_t)mp, 0, "vfs_busy", 0);
237 		if (interlkp) {
238 			lwkt_gettoken(interlkp);
239 		}
240 		return (ENOENT);
241 	}
242 	lkflags = LK_SHARED | LK_NOPAUSE;
243 	if (interlkp)
244 		lkflags |= LK_INTERLOCK;
245 	if (lockmgr(&mp->mnt_lock, lkflags, interlkp, td))
246 		panic("vfs_busy: unexpected lock failure");
247 	return (0);
248 }
249 
250 /*
251  * Free a busy filesystem.
252  */
253 void
254 vfs_unbusy(struct mount *mp, struct thread *td)
255 {
256 	lockmgr(&mp->mnt_lock, LK_RELEASE, NULL, td);
257 }
258 
259 /*
260  * Lookup a filesystem type, and if found allocate and initialize
261  * a mount structure for it.
262  *
263  * Devname is usually updated by mount(8) after booting.
264  */
265 int
266 vfs_rootmountalloc(char *fstypename, char *devname, struct mount **mpp)
267 {
268 	struct thread *td = curthread;	/* XXX */
269 	struct vfsconf *vfsp;
270 	struct mount *mp;
271 
272 	if (fstypename == NULL)
273 		return (ENODEV);
274 	for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
275 		if (!strcmp(vfsp->vfc_name, fstypename))
276 			break;
277 	if (vfsp == NULL)
278 		return (ENODEV);
279 	mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
280 	bzero((char *)mp, (u_long)sizeof(struct mount));
281 	lockinit(&mp->mnt_lock, 0, "vfslock", VLKTIMEOUT, LK_NOPAUSE);
282 	(void)vfs_busy(mp, LK_NOWAIT, 0, td);
283 	TAILQ_INIT(&mp->mnt_nvnodelist);
284 	TAILQ_INIT(&mp->mnt_reservedvnlist);
285 	mp->mnt_nvnodelistsize = 0;
286 	mp->mnt_vfc = vfsp;
287 	mp->mnt_op = vfsp->vfc_vfsops;
288 	mp->mnt_flag = MNT_RDONLY;
289 	mp->mnt_vnodecovered = NULLVP;
290 	vfsp->vfc_refcount++;
291 	mp->mnt_iosize_max = DFLTPHYS;
292 	mp->mnt_stat.f_type = vfsp->vfc_typenum;
293 	mp->mnt_flag |= vfsp->vfc_flags & MNT_VISFLAGMASK;
294 	strncpy(mp->mnt_stat.f_fstypename, vfsp->vfc_name, MFSNAMELEN);
295 	mp->mnt_stat.f_mntonname[0] = '/';
296 	mp->mnt_stat.f_mntonname[1] = 0;
297 	(void) copystr(devname, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 0);
298 	*mpp = mp;
299 	return (0);
300 }
301 
302 /*
303  * Find an appropriate filesystem to use for the root. If a filesystem
304  * has not been preselected, walk through the list of known filesystems
305  * trying those that have mountroot routines, and try them until one
306  * works or we have tried them all.
307  */
308 #ifdef notdef	/* XXX JH */
309 int
310 lite2_vfs_mountroot()
311 {
312 	struct vfsconf *vfsp;
313 	extern int (*lite2_mountroot) (void);
314 	int error;
315 
316 	if (lite2_mountroot != NULL)
317 		return ((*lite2_mountroot)());
318 	for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
319 		if (vfsp->vfc_mountroot == NULL)
320 			continue;
321 		if ((error = (*vfsp->vfc_mountroot)()) == 0)
322 			return (0);
323 		printf("%s_mountroot failed: %d\n", vfsp->vfc_name, error);
324 	}
325 	return (ENODEV);
326 }
327 #endif
328 
329 /*
330  * Lookup a mount point by filesystem identifier.
331  */
332 struct mount *
333 vfs_getvfs(fsid)
334 	fsid_t *fsid;
335 {
336 	struct mount *mp;
337 
338 	lwkt_gettoken(&mountlist_token);
339 	TAILQ_FOREACH(mp, &mountlist, mnt_list) {
340 		if (mp->mnt_stat.f_fsid.val[0] == fsid->val[0] &&
341 		    mp->mnt_stat.f_fsid.val[1] == fsid->val[1]) {
342 			lwkt_reltoken(&mountlist_token);
343 			return (mp);
344 	    }
345 	}
346 	lwkt_reltoken(&mountlist_token);
347 	return ((struct mount *) 0);
348 }
349 
350 /*
351  * Get a new unique fsid.  Try to make its val[0] unique, since this value
352  * will be used to create fake device numbers for stat().  Also try (but
353  * not so hard) make its val[0] unique mod 2^16, since some emulators only
354  * support 16-bit device numbers.  We end up with unique val[0]'s for the
355  * first 2^16 calls and unique val[0]'s mod 2^16 for the first 2^8 calls.
356  *
357  * Keep in mind that several mounts may be running in parallel.  Starting
358  * the search one past where the previous search terminated is both a
359  * micro-optimization and a defense against returning the same fsid to
360  * different mounts.
361  */
362 void
363 vfs_getnewfsid(mp)
364 	struct mount *mp;
365 {
366 	static u_int16_t mntid_base;
367 	fsid_t tfsid;
368 	int mtype;
369 
370 	lwkt_gettoken(&mntid_token);
371 	mtype = mp->mnt_vfc->vfc_typenum;
372 	tfsid.val[1] = mtype;
373 	mtype = (mtype & 0xFF) << 24;
374 	for (;;) {
375 		tfsid.val[0] = makeudev(255,
376 		    mtype | ((mntid_base & 0xFF00) << 8) | (mntid_base & 0xFF));
377 		mntid_base++;
378 		if (vfs_getvfs(&tfsid) == NULL)
379 			break;
380 	}
381 	mp->mnt_stat.f_fsid.val[0] = tfsid.val[0];
382 	mp->mnt_stat.f_fsid.val[1] = tfsid.val[1];
383 	lwkt_reltoken(&mntid_token);
384 }
385 
386 /*
387  * Knob to control the precision of file timestamps:
388  *
389  *   0 = seconds only; nanoseconds zeroed.
390  *   1 = seconds and nanoseconds, accurate within 1/HZ.
391  *   2 = seconds and nanoseconds, truncated to microseconds.
392  * >=3 = seconds and nanoseconds, maximum precision.
393  */
394 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
395 
396 static int timestamp_precision = TSP_SEC;
397 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
398     &timestamp_precision, 0, "");
399 
400 /*
401  * Get a current timestamp.
402  */
403 void
404 vfs_timestamp(tsp)
405 	struct timespec *tsp;
406 {
407 	struct timeval tv;
408 
409 	switch (timestamp_precision) {
410 	case TSP_SEC:
411 		tsp->tv_sec = time_second;
412 		tsp->tv_nsec = 0;
413 		break;
414 	case TSP_HZ:
415 		getnanotime(tsp);
416 		break;
417 	case TSP_USEC:
418 		microtime(&tv);
419 		TIMEVAL_TO_TIMESPEC(&tv, tsp);
420 		break;
421 	case TSP_NSEC:
422 	default:
423 		nanotime(tsp);
424 		break;
425 	}
426 }
427 
428 /*
429  * Set vnode attributes to VNOVAL
430  */
431 void
432 vattr_null(vap)
433 	struct vattr *vap;
434 {
435 
436 	vap->va_type = VNON;
437 	vap->va_size = VNOVAL;
438 	vap->va_bytes = VNOVAL;
439 	vap->va_mode = VNOVAL;
440 	vap->va_nlink = VNOVAL;
441 	vap->va_uid = VNOVAL;
442 	vap->va_gid = VNOVAL;
443 	vap->va_fsid = VNOVAL;
444 	vap->va_fileid = VNOVAL;
445 	vap->va_blocksize = VNOVAL;
446 	vap->va_rdev = VNOVAL;
447 	vap->va_atime.tv_sec = VNOVAL;
448 	vap->va_atime.tv_nsec = VNOVAL;
449 	vap->va_mtime.tv_sec = VNOVAL;
450 	vap->va_mtime.tv_nsec = VNOVAL;
451 	vap->va_ctime.tv_sec = VNOVAL;
452 	vap->va_ctime.tv_nsec = VNOVAL;
453 	vap->va_flags = VNOVAL;
454 	vap->va_gen = VNOVAL;
455 	vap->va_vaflags = 0;
456 }
457 
458 /*
459  * This routine is called when we have too many vnodes.  It attempts
460  * to free <count> vnodes and will potentially free vnodes that still
461  * have VM backing store (VM backing store is typically the cause
462  * of a vnode blowout so we want to do this).  Therefore, this operation
463  * is not considered cheap.
464  *
465  * A number of conditions may prevent a vnode from being reclaimed.
466  * the buffer cache may have references on the vnode, a directory
467  * vnode may still have references due to the namei cache representing
468  * underlying files, or the vnode may be in active use.   It is not
469  * desireable to reuse such vnodes.  These conditions may cause the
470  * number of vnodes to reach some minimum value regardless of what
471  * you set kern.maxvnodes to.  Do not set kern.maxvnodes too low.
472  */
473 static int
474 vlrureclaim(struct mount *mp)
475 {
476 	struct vnode *vp;
477 	int done;
478 	int trigger;
479 	int usevnodes;
480 	int count;
481 	int gen;
482 
483 	/*
484 	 * Calculate the trigger point, don't allow user
485 	 * screwups to blow us up.   This prevents us from
486 	 * recycling vnodes with lots of resident pages.  We
487 	 * aren't trying to free memory, we are trying to
488 	 * free vnodes.
489 	 */
490 	usevnodes = desiredvnodes;
491 	if (usevnodes <= 0)
492 		usevnodes = 1;
493 	trigger = vmstats.v_page_count * 2 / usevnodes;
494 
495 	done = 0;
496 	gen = lwkt_gettoken(&mntvnode_token);
497 	count = mp->mnt_nvnodelistsize / 10 + 1;
498 	while (count && (vp = TAILQ_FIRST(&mp->mnt_nvnodelist)) != NULL) {
499 		TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
500 		TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
501 
502 		if (vp->v_type != VNON &&
503 		    vp->v_type != VBAD &&
504 		    VMIGHTFREE(vp) &&		/* critical path opt */
505 		    (vp->v_object == NULL || vp->v_object->resident_page_count < trigger)
506 		) {
507 			lwkt_gettoken(&vp->v_interlock);
508 			if (lwkt_gentoken(&mntvnode_token, &gen) == 0) {
509 				if (VMIGHTFREE(vp)) {
510 					vgonel(vp, curthread);
511 					done++;
512 				} else {
513 					lwkt_reltoken(&vp->v_interlock);
514 				}
515 			} else {
516 				lwkt_reltoken(&vp->v_interlock);
517 			}
518 		}
519 		--count;
520 	}
521 	lwkt_reltoken(&mntvnode_token);
522 	return done;
523 }
524 
525 /*
526  * Attempt to recycle vnodes in a context that is always safe to block.
527  * Calling vlrurecycle() from the bowels of file system code has some
528  * interesting deadlock problems.
529  */
530 static struct thread *vnlruthread;
531 static int vnlruproc_sig;
532 
533 static void
534 vnlru_proc(void)
535 {
536 	struct mount *mp, *nmp;
537 	int s;
538 	int done;
539 	struct thread *td = curthread;
540 
541 	EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_kproc, td,
542 	    SHUTDOWN_PRI_FIRST);
543 
544 	s = splbio();
545 	for (;;) {
546 		kproc_suspend_loop();
547 		if (numvnodes - freevnodes <= desiredvnodes * 9 / 10) {
548 			vnlruproc_sig = 0;
549 			wakeup(&vnlruproc_sig);
550 			tsleep(td, 0, "vlruwt", hz);
551 			continue;
552 		}
553 		done = 0;
554 		lwkt_gettoken(&mountlist_token);
555 		for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
556 			if (vfs_busy(mp, LK_NOWAIT, &mountlist_token, td)) {
557 				nmp = TAILQ_NEXT(mp, mnt_list);
558 				continue;
559 			}
560 			done += vlrureclaim(mp);
561 			lwkt_gettoken(&mountlist_token);
562 			nmp = TAILQ_NEXT(mp, mnt_list);
563 			vfs_unbusy(mp, td);
564 		}
565 		lwkt_reltoken(&mountlist_token);
566 		if (done == 0) {
567 			vnlru_nowhere++;
568 			tsleep(td, 0, "vlrup", hz * 3);
569 		}
570 	}
571 	splx(s);
572 }
573 
574 static struct kproc_desc vnlru_kp = {
575 	"vnlru",
576 	vnlru_proc,
577 	&vnlruthread
578 };
579 SYSINIT(vnlru, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &vnlru_kp)
580 
581 /*
582  * Routines having to do with the management of the vnode table.
583  */
584 extern vop_t **dead_vnodeop_p;
585 
586 /*
587  * Return the next vnode from the free list.
588  */
589 int
590 getnewvnode(tag, mp, vops, vpp)
591 	enum vtagtype tag;
592 	struct mount *mp;
593 	vop_t **vops;
594 	struct vnode **vpp;
595 {
596 	int s;
597 	int gen;
598 	int vgen;
599 	struct thread *td = curthread;	/* XXX */
600 	struct vnode *vp = NULL;
601 	vm_object_t object;
602 
603 	s = splbio();
604 
605 	/*
606 	 * Try to reuse vnodes if we hit the max.  This situation only
607 	 * occurs in certain large-memory (2G+) situations.  We cannot
608 	 * attempt to directly reclaim vnodes due to nasty recursion
609 	 * problems.
610 	 */
611 	while (numvnodes - freevnodes > desiredvnodes) {
612 		if (vnlruproc_sig == 0) {
613 			vnlruproc_sig = 1;	/* avoid unnecessary wakeups */
614 			wakeup(vnlruthread);
615 		}
616 		tsleep(&vnlruproc_sig, 0, "vlruwk", hz);
617 	}
618 
619 
620 	/*
621 	 * Attempt to reuse a vnode already on the free list, allocating
622 	 * a new vnode if we can't find one or if we have not reached a
623 	 * good minimum for good LRU performance.
624 	 */
625 	gen = lwkt_gettoken(&vnode_free_list_token);
626 	if (freevnodes >= wantfreevnodes && numvnodes >= minvnodes) {
627 		int count;
628 
629 		for (count = 0; count < freevnodes; count++) {
630 			vp = TAILQ_FIRST(&vnode_free_list);
631 			if (vp == NULL || vp->v_usecount)
632 				panic("getnewvnode: free vnode isn't");
633 
634 			/*
635 			 * Get the vnode's interlock, then re-obtain
636 			 * vnode_free_list_token in case we lost it.  If we
637 			 * did lose it while getting the vnode interlock,
638 			 * even if we got it back again, then retry.
639 			 */
640 			vgen = lwkt_gettoken(&vp->v_interlock);
641 			if (lwkt_gentoken(&vnode_free_list_token, &gen) != 0) {
642 				--count;
643 				lwkt_reltoken(&vp->v_interlock);
644 				vp = NULL;
645 				continue;
646 			}
647 
648 			/*
649 			 * Whew!  We have both tokens.  Since we didn't lose
650 			 * the free list VFREE had better still be set.  But
651 			 * we aren't out of the woods yet.  We have to get
652 			 * the object (may block).  If the vnode is not
653 			 * suitable then move it to the end of the list
654 			 * if we can.  If we can't move it to the end of the
655 			 * list retry again.
656 			 */
657 			if ((VOP_GETVOBJECT(vp, &object) == 0 &&
658 			    (object->resident_page_count || object->ref_count))
659 			) {
660 				if (lwkt_gentoken(&vp->v_interlock, &vgen) == 0 &&
661 				   lwkt_gentoken(&vnode_free_list_token, &gen) == 0
662 				) {
663 					TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
664 					TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
665 				} else {
666 					--count;
667 				}
668 				lwkt_reltoken(&vp->v_interlock);
669 				vp = NULL;
670 				continue;
671 			}
672 
673 			/*
674 			 * Still not out of the woods.  VOBJECT might have
675 			 * blocked, if we did not retain our tokens we have
676 			 * to retry.
677 			 */
678 			if (lwkt_gentoken(&vp->v_interlock, &vgen) != 0 ||
679 			    lwkt_gentoken(&vnode_free_list_token, &gen) != 0) {
680 				--count;
681 				vp = NULL;
682 				continue;
683 			}
684 			TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
685 			KKASSERT(vp->v_flag & VFREE);
686 
687 			/*
688 			 * If we have children in the namecache we cannot
689 			 * reuse the vnode yet because it will break the
690 			 * namecache chain (YYY use nc_refs for the check?)
691 			 */
692 			if (TAILQ_FIRST(&vp->v_namecache)) {
693 				if (cache_leaf_test(vp) < 0) {
694 					lwkt_reltoken(&vp->v_interlock);
695 					TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
696 					vp = NULL;
697 					continue;
698 				}
699 			}
700 			break;
701 		}
702 	}
703 
704 	if (vp) {
705 		vp->v_flag |= VDOOMED;
706 		vp->v_flag &= ~VFREE;
707 		freevnodes--;
708 		lwkt_reltoken(&vnode_free_list_token);
709 		cache_purge(vp);	/* YYY may block */
710 		vp->v_lease = NULL;
711 		if (vp->v_type != VBAD) {
712 			vgonel(vp, td);
713 		} else {
714 			lwkt_reltoken(&vp->v_interlock);
715 		}
716 
717 #ifdef INVARIANTS
718 		{
719 			int s;
720 
721 			if (vp->v_data)
722 				panic("cleaned vnode isn't");
723 			s = splbio();
724 			if (vp->v_numoutput)
725 				panic("Clean vnode has pending I/O's");
726 			splx(s);
727 		}
728 #endif
729 		vp->v_flag = 0;
730 		vp->v_lastw = 0;
731 		vp->v_lasta = 0;
732 		vp->v_cstart = 0;
733 		vp->v_clen = 0;
734 		vp->v_socket = 0;
735 		vp->v_writecount = 0;	/* XXX */
736 	} else {
737 		lwkt_reltoken(&vnode_free_list_token);
738 		vp = (struct vnode *) zalloc(vnode_zone);
739 		bzero((char *) vp, sizeof *vp);
740 		lwkt_inittoken(&vp->v_interlock);
741 		lwkt_inittoken(&vp->v_pollinfo.vpi_token);
742 		vp->v_dd = vp;
743 		cache_purge(vp);
744 		TAILQ_INIT(&vp->v_namecache);
745 		numvnodes++;
746 	}
747 
748 	TAILQ_INIT(&vp->v_cleanblkhd);
749 	TAILQ_INIT(&vp->v_dirtyblkhd);
750 	vp->v_type = VNON;
751 	vp->v_tag = tag;
752 	vp->v_op = vops;
753 	insmntque(vp, mp);
754 	*vpp = vp;
755 	vp->v_usecount = 1;
756 	vp->v_data = 0;
757 	splx(s);
758 
759 	vfs_object_create(vp, td);
760 	return (0);
761 }
762 
763 /*
764  * Move a vnode from one mount queue to another.
765  */
766 static void
767 insmntque(vp, mp)
768 	struct vnode *vp;
769 	struct mount *mp;
770 {
771 
772 	lwkt_gettoken(&mntvnode_token);
773 	/*
774 	 * Delete from old mount point vnode list, if on one.
775 	 */
776 	if (vp->v_mount != NULL) {
777 		KASSERT(vp->v_mount->mnt_nvnodelistsize > 0,
778 			("bad mount point vnode list size"));
779 		TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes);
780 		vp->v_mount->mnt_nvnodelistsize--;
781 	}
782 	/*
783 	 * Insert into list of vnodes for the new mount point, if available.
784 	 */
785 	if ((vp->v_mount = mp) == NULL) {
786 		lwkt_reltoken(&mntvnode_token);
787 		return;
788 	}
789 	TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
790 	mp->mnt_nvnodelistsize++;
791 	lwkt_reltoken(&mntvnode_token);
792 }
793 
794 /*
795  * Update outstanding I/O count and do wakeup if requested.
796  */
797 void
798 vwakeup(bp)
799 	struct buf *bp;
800 {
801 	struct vnode *vp;
802 
803 	bp->b_flags &= ~B_WRITEINPROG;
804 	if ((vp = bp->b_vp)) {
805 		vp->v_numoutput--;
806 		if (vp->v_numoutput < 0)
807 			panic("vwakeup: neg numoutput");
808 		if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) {
809 			vp->v_flag &= ~VBWAIT;
810 			wakeup((caddr_t) &vp->v_numoutput);
811 		}
812 	}
813 }
814 
815 /*
816  * Flush out and invalidate all buffers associated with a vnode.
817  * Called with the underlying object locked.
818  */
819 int
820 vinvalbuf(struct vnode *vp, int flags, struct thread *td,
821 	int slpflag, int slptimeo)
822 {
823 	struct buf *bp;
824 	struct buf *nbp, *blist;
825 	int s, error;
826 	vm_object_t object;
827 
828 	if (flags & V_SAVE) {
829 		s = splbio();
830 		while (vp->v_numoutput) {
831 			vp->v_flag |= VBWAIT;
832 			error = tsleep((caddr_t)&vp->v_numoutput,
833 			    slpflag, "vinvlbuf", slptimeo);
834 			if (error) {
835 				splx(s);
836 				return (error);
837 			}
838 		}
839 		if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
840 			splx(s);
841 			if ((error = VOP_FSYNC(vp, MNT_WAIT, td)) != 0)
842 				return (error);
843 			s = splbio();
844 			if (vp->v_numoutput > 0 ||
845 			    !TAILQ_EMPTY(&vp->v_dirtyblkhd))
846 				panic("vinvalbuf: dirty bufs");
847 		}
848 		splx(s);
849   	}
850 	s = splbio();
851 	for (;;) {
852 		blist = TAILQ_FIRST(&vp->v_cleanblkhd);
853 		if (!blist)
854 			blist = TAILQ_FIRST(&vp->v_dirtyblkhd);
855 		if (!blist)
856 			break;
857 
858 		for (bp = blist; bp; bp = nbp) {
859 			nbp = TAILQ_NEXT(bp, b_vnbufs);
860 			if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
861 				error = BUF_TIMELOCK(bp,
862 				    LK_EXCLUSIVE | LK_SLEEPFAIL,
863 				    "vinvalbuf", slpflag, slptimeo);
864 				if (error == ENOLCK)
865 					break;
866 				splx(s);
867 				return (error);
868 			}
869 			/*
870 			 * XXX Since there are no node locks for NFS, I
871 			 * believe there is a slight chance that a delayed
872 			 * write will occur while sleeping just above, so
873 			 * check for it.  Note that vfs_bio_awrite expects
874 			 * buffers to reside on a queue, while VOP_BWRITE and
875 			 * brelse do not.
876 			 */
877 			if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
878 				(flags & V_SAVE)) {
879 
880 				if (bp->b_vp == vp) {
881 					if (bp->b_flags & B_CLUSTEROK) {
882 						BUF_UNLOCK(bp);
883 						vfs_bio_awrite(bp);
884 					} else {
885 						bremfree(bp);
886 						bp->b_flags |= B_ASYNC;
887 						VOP_BWRITE(bp->b_vp, bp);
888 					}
889 				} else {
890 					bremfree(bp);
891 					(void) VOP_BWRITE(bp->b_vp, bp);
892 				}
893 				break;
894 			}
895 			bremfree(bp);
896 			bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF);
897 			bp->b_flags &= ~B_ASYNC;
898 			brelse(bp);
899 		}
900 	}
901 
902 	/*
903 	 * Wait for I/O to complete.  XXX needs cleaning up.  The vnode can
904 	 * have write I/O in-progress but if there is a VM object then the
905 	 * VM object can also have read-I/O in-progress.
906 	 */
907 	do {
908 		while (vp->v_numoutput > 0) {
909 			vp->v_flag |= VBWAIT;
910 			tsleep(&vp->v_numoutput, 0, "vnvlbv", 0);
911 		}
912 		if (VOP_GETVOBJECT(vp, &object) == 0) {
913 			while (object->paging_in_progress)
914 				vm_object_pip_sleep(object, "vnvlbx");
915 		}
916 	} while (vp->v_numoutput > 0);
917 
918 	splx(s);
919 
920 	/*
921 	 * Destroy the copy in the VM cache, too.
922 	 */
923 	lwkt_gettoken(&vp->v_interlock);
924 	if (VOP_GETVOBJECT(vp, &object) == 0) {
925 		vm_object_page_remove(object, 0, 0,
926 			(flags & V_SAVE) ? TRUE : FALSE);
927 	}
928 	lwkt_reltoken(&vp->v_interlock);
929 
930 	if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || !TAILQ_EMPTY(&vp->v_cleanblkhd))
931 		panic("vinvalbuf: flush failed");
932 	return (0);
933 }
934 
935 /*
936  * Truncate a file's buffer and pages to a specified length.  This
937  * is in lieu of the old vinvalbuf mechanism, which performed unneeded
938  * sync activity.
939  */
940 int
941 vtruncbuf(struct vnode *vp, struct thread *td, off_t length, int blksize)
942 {
943 	struct buf *bp;
944 	struct buf *nbp;
945 	int s, anyfreed;
946 	int trunclbn;
947 
948 	/*
949 	 * Round up to the *next* lbn.
950 	 */
951 	trunclbn = (length + blksize - 1) / blksize;
952 
953 	s = splbio();
954 restart:
955 	anyfreed = 1;
956 	for (;anyfreed;) {
957 		anyfreed = 0;
958 		for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
959 			nbp = TAILQ_NEXT(bp, b_vnbufs);
960 			if (bp->b_lblkno >= trunclbn) {
961 				if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
962 					BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL);
963 					goto restart;
964 				} else {
965 					bremfree(bp);
966 					bp->b_flags |= (B_INVAL | B_RELBUF);
967 					bp->b_flags &= ~B_ASYNC;
968 					brelse(bp);
969 					anyfreed = 1;
970 				}
971 				if (nbp &&
972 				    (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
973 				    (nbp->b_vp != vp) ||
974 				    (nbp->b_flags & B_DELWRI))) {
975 					goto restart;
976 				}
977 			}
978 		}
979 
980 		for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
981 			nbp = TAILQ_NEXT(bp, b_vnbufs);
982 			if (bp->b_lblkno >= trunclbn) {
983 				if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
984 					BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL);
985 					goto restart;
986 				} else {
987 					bremfree(bp);
988 					bp->b_flags |= (B_INVAL | B_RELBUF);
989 					bp->b_flags &= ~B_ASYNC;
990 					brelse(bp);
991 					anyfreed = 1;
992 				}
993 				if (nbp &&
994 				    (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
995 				    (nbp->b_vp != vp) ||
996 				    (nbp->b_flags & B_DELWRI) == 0)) {
997 					goto restart;
998 				}
999 			}
1000 		}
1001 	}
1002 
1003 	if (length > 0) {
1004 restartsync:
1005 		for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
1006 			nbp = TAILQ_NEXT(bp, b_vnbufs);
1007 			if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) {
1008 				if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
1009 					BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL);
1010 					goto restart;
1011 				} else {
1012 					bremfree(bp);
1013 					if (bp->b_vp == vp) {
1014 						bp->b_flags |= B_ASYNC;
1015 					} else {
1016 						bp->b_flags &= ~B_ASYNC;
1017 					}
1018 					VOP_BWRITE(bp->b_vp, bp);
1019 				}
1020 				goto restartsync;
1021 			}
1022 
1023 		}
1024 	}
1025 
1026 	while (vp->v_numoutput > 0) {
1027 		vp->v_flag |= VBWAIT;
1028 		tsleep(&vp->v_numoutput, 0, "vbtrunc", 0);
1029 	}
1030 
1031 	splx(s);
1032 
1033 	vnode_pager_setsize(vp, length);
1034 
1035 	return (0);
1036 }
1037 
1038 /*
1039  * Associate a buffer with a vnode.
1040  */
1041 void
1042 bgetvp(vp, bp)
1043 	struct vnode *vp;
1044 	struct buf *bp;
1045 {
1046 	int s;
1047 
1048 	KASSERT(bp->b_vp == NULL, ("bgetvp: not free"));
1049 
1050 	vhold(vp);
1051 	bp->b_vp = vp;
1052 	bp->b_dev = vn_todev(vp);
1053 	/*
1054 	 * Insert onto list for new vnode.
1055 	 */
1056 	s = splbio();
1057 	bp->b_xflags |= BX_VNCLEAN;
1058 	bp->b_xflags &= ~BX_VNDIRTY;
1059 	TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs);
1060 	splx(s);
1061 }
1062 
1063 /*
1064  * Disassociate a buffer from a vnode.
1065  */
1066 void
1067 brelvp(bp)
1068 	struct buf *bp;
1069 {
1070 	struct vnode *vp;
1071 	struct buflists *listheadp;
1072 	int s;
1073 
1074 	KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
1075 
1076 	/*
1077 	 * Delete from old vnode list, if on one.
1078 	 */
1079 	vp = bp->b_vp;
1080 	s = splbio();
1081 	if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) {
1082 		if (bp->b_xflags & BX_VNDIRTY)
1083 			listheadp = &vp->v_dirtyblkhd;
1084 		else
1085 			listheadp = &vp->v_cleanblkhd;
1086 		TAILQ_REMOVE(listheadp, bp, b_vnbufs);
1087 		bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1088 	}
1089 	if ((vp->v_flag & VONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
1090 		vp->v_flag &= ~VONWORKLST;
1091 		LIST_REMOVE(vp, v_synclist);
1092 	}
1093 	splx(s);
1094 	bp->b_vp = (struct vnode *) 0;
1095 	vdrop(vp);
1096 }
1097 
1098 /*
1099  * The workitem queue.
1100  *
1101  * It is useful to delay writes of file data and filesystem metadata
1102  * for tens of seconds so that quickly created and deleted files need
1103  * not waste disk bandwidth being created and removed. To realize this,
1104  * we append vnodes to a "workitem" queue. When running with a soft
1105  * updates implementation, most pending metadata dependencies should
1106  * not wait for more than a few seconds. Thus, mounted on block devices
1107  * are delayed only about a half the time that file data is delayed.
1108  * Similarly, directory updates are more critical, so are only delayed
1109  * about a third the time that file data is delayed. Thus, there are
1110  * SYNCER_MAXDELAY queues that are processed round-robin at a rate of
1111  * one each second (driven off the filesystem syncer process). The
1112  * syncer_delayno variable indicates the next queue that is to be processed.
1113  * Items that need to be processed soon are placed in this queue:
1114  *
1115  *	syncer_workitem_pending[syncer_delayno]
1116  *
1117  * A delay of fifteen seconds is done by placing the request fifteen
1118  * entries later in the queue:
1119  *
1120  *	syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
1121  *
1122  */
1123 
1124 /*
1125  * Add an item to the syncer work queue.
1126  */
1127 static void
1128 vn_syncer_add_to_worklist(struct vnode *vp, int delay)
1129 {
1130 	int s, slot;
1131 
1132 	s = splbio();
1133 
1134 	if (vp->v_flag & VONWORKLST) {
1135 		LIST_REMOVE(vp, v_synclist);
1136 	}
1137 
1138 	if (delay > syncer_maxdelay - 2)
1139 		delay = syncer_maxdelay - 2;
1140 	slot = (syncer_delayno + delay) & syncer_mask;
1141 
1142 	LIST_INSERT_HEAD(&syncer_workitem_pending[slot], vp, v_synclist);
1143 	vp->v_flag |= VONWORKLST;
1144 	splx(s);
1145 }
1146 
1147 struct  thread *updatethread;
1148 static void sched_sync (void);
1149 static struct kproc_desc up_kp = {
1150 	"syncer",
1151 	sched_sync,
1152 	&updatethread
1153 };
1154 SYSINIT(syncer, SI_SUB_KTHREAD_UPDATE, SI_ORDER_FIRST, kproc_start, &up_kp)
1155 
1156 /*
1157  * System filesystem synchronizer daemon.
1158  */
1159 void
1160 sched_sync(void)
1161 {
1162 	struct synclist *slp;
1163 	struct vnode *vp;
1164 	long starttime;
1165 	int s;
1166 	struct thread *td = curthread;
1167 
1168 	EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_kproc, td,
1169 	    SHUTDOWN_PRI_LAST);
1170 
1171 	for (;;) {
1172 		kproc_suspend_loop();
1173 
1174 		starttime = time_second;
1175 
1176 		/*
1177 		 * Push files whose dirty time has expired.  Be careful
1178 		 * of interrupt race on slp queue.
1179 		 */
1180 		s = splbio();
1181 		slp = &syncer_workitem_pending[syncer_delayno];
1182 		syncer_delayno += 1;
1183 		if (syncer_delayno == syncer_maxdelay)
1184 			syncer_delayno = 0;
1185 		splx(s);
1186 
1187 		while ((vp = LIST_FIRST(slp)) != NULL) {
1188 			if (VOP_ISLOCKED(vp, NULL) == 0) {
1189 				vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
1190 				(void) VOP_FSYNC(vp, MNT_LAZY, td);
1191 				VOP_UNLOCK(vp, 0, td);
1192 			}
1193 			s = splbio();
1194 			if (LIST_FIRST(slp) == vp) {
1195 				/*
1196 				 * Note: v_tag VT_VFS vps can remain on the
1197 				 * worklist too with no dirty blocks, but
1198 				 * since sync_fsync() moves it to a different
1199 				 * slot we are safe.
1200 				 */
1201 				if (TAILQ_EMPTY(&vp->v_dirtyblkhd) &&
1202 				    !vn_isdisk(vp, NULL))
1203 					panic("sched_sync: fsync failed vp %p tag %d", vp, vp->v_tag);
1204 				/*
1205 				 * Put us back on the worklist.  The worklist
1206 				 * routine will remove us from our current
1207 				 * position and then add us back in at a later
1208 				 * position.
1209 				 */
1210 				vn_syncer_add_to_worklist(vp, syncdelay);
1211 			}
1212 			splx(s);
1213 		}
1214 
1215 		/*
1216 		 * Do soft update processing.
1217 		 */
1218 		if (bioops.io_sync)
1219 			(*bioops.io_sync)(NULL);
1220 
1221 		/*
1222 		 * The variable rushjob allows the kernel to speed up the
1223 		 * processing of the filesystem syncer process. A rushjob
1224 		 * value of N tells the filesystem syncer to process the next
1225 		 * N seconds worth of work on its queue ASAP. Currently rushjob
1226 		 * is used by the soft update code to speed up the filesystem
1227 		 * syncer process when the incore state is getting so far
1228 		 * ahead of the disk that the kernel memory pool is being
1229 		 * threatened with exhaustion.
1230 		 */
1231 		if (rushjob > 0) {
1232 			rushjob -= 1;
1233 			continue;
1234 		}
1235 		/*
1236 		 * If it has taken us less than a second to process the
1237 		 * current work, then wait. Otherwise start right over
1238 		 * again. We can still lose time if any single round
1239 		 * takes more than two seconds, but it does not really
1240 		 * matter as we are just trying to generally pace the
1241 		 * filesystem activity.
1242 		 */
1243 		if (time_second == starttime)
1244 			tsleep(&lbolt, 0, "syncer", 0);
1245 	}
1246 }
1247 
1248 /*
1249  * Request the syncer daemon to speed up its work.
1250  * We never push it to speed up more than half of its
1251  * normal turn time, otherwise it could take over the cpu.
1252  *
1253  * YYY wchan field protected by the BGL.
1254  */
1255 int
1256 speedup_syncer()
1257 {
1258 	crit_enter();
1259 	if (updatethread->td_wchan == &lbolt) { /* YYY */
1260 		unsleep(updatethread);
1261 		lwkt_schedule(updatethread);
1262 	}
1263 	crit_exit();
1264 	if (rushjob < syncdelay / 2) {
1265 		rushjob += 1;
1266 		stat_rush_requests += 1;
1267 		return (1);
1268 	}
1269 	return(0);
1270 }
1271 
1272 /*
1273  * Associate a p-buffer with a vnode.
1274  *
1275  * Also sets B_PAGING flag to indicate that vnode is not fully associated
1276  * with the buffer.  i.e. the bp has not been linked into the vnode or
1277  * ref-counted.
1278  */
1279 void
1280 pbgetvp(vp, bp)
1281 	struct vnode *vp;
1282 	struct buf *bp;
1283 {
1284 
1285 	KASSERT(bp->b_vp == NULL, ("pbgetvp: not free"));
1286 
1287 	bp->b_vp = vp;
1288 	bp->b_flags |= B_PAGING;
1289 	bp->b_dev = vn_todev(vp);
1290 }
1291 
1292 /*
1293  * Disassociate a p-buffer from a vnode.
1294  */
1295 void
1296 pbrelvp(bp)
1297 	struct buf *bp;
1298 {
1299 
1300 	KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL"));
1301 
1302 	/* XXX REMOVE ME */
1303 	if (TAILQ_NEXT(bp, b_vnbufs) != NULL) {
1304 		panic(
1305 		    "relpbuf(): b_vp was probably reassignbuf()d %p %x",
1306 		    bp,
1307 		    (int)bp->b_flags
1308 		);
1309 	}
1310 	bp->b_vp = (struct vnode *) 0;
1311 	bp->b_flags &= ~B_PAGING;
1312 }
1313 
1314 void
1315 pbreassignbuf(bp, newvp)
1316 	struct buf *bp;
1317 	struct vnode *newvp;
1318 {
1319 	if ((bp->b_flags & B_PAGING) == 0) {
1320 		panic(
1321 		    "pbreassignbuf() on non phys bp %p",
1322 		    bp
1323 		);
1324 	}
1325 	bp->b_vp = newvp;
1326 }
1327 
1328 /*
1329  * Reassign a buffer from one vnode to another.
1330  * Used to assign file specific control information
1331  * (indirect blocks) to the vnode to which they belong.
1332  */
1333 void
1334 reassignbuf(bp, newvp)
1335 	struct buf *bp;
1336 	struct vnode *newvp;
1337 {
1338 	struct buflists *listheadp;
1339 	int delay;
1340 	int s;
1341 
1342 	if (newvp == NULL) {
1343 		printf("reassignbuf: NULL");
1344 		return;
1345 	}
1346 	++reassignbufcalls;
1347 
1348 	/*
1349 	 * B_PAGING flagged buffers cannot be reassigned because their vp
1350 	 * is not fully linked in.
1351 	 */
1352 	if (bp->b_flags & B_PAGING)
1353 		panic("cannot reassign paging buffer");
1354 
1355 	s = splbio();
1356 	/*
1357 	 * Delete from old vnode list, if on one.
1358 	 */
1359 	if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) {
1360 		if (bp->b_xflags & BX_VNDIRTY)
1361 			listheadp = &bp->b_vp->v_dirtyblkhd;
1362 		else
1363 			listheadp = &bp->b_vp->v_cleanblkhd;
1364 		TAILQ_REMOVE(listheadp, bp, b_vnbufs);
1365 		bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
1366 		if (bp->b_vp != newvp) {
1367 			vdrop(bp->b_vp);
1368 			bp->b_vp = NULL;	/* for clarification */
1369 		}
1370 	}
1371 	/*
1372 	 * If dirty, put on list of dirty buffers; otherwise insert onto list
1373 	 * of clean buffers.
1374 	 */
1375 	if (bp->b_flags & B_DELWRI) {
1376 		struct buf *tbp;
1377 
1378 		listheadp = &newvp->v_dirtyblkhd;
1379 		if ((newvp->v_flag & VONWORKLST) == 0) {
1380 			switch (newvp->v_type) {
1381 			case VDIR:
1382 				delay = dirdelay;
1383 				break;
1384 			case VCHR:
1385 			case VBLK:
1386 				if (newvp->v_specmountpoint != NULL) {
1387 					delay = metadelay;
1388 					break;
1389 				}
1390 				/* fall through */
1391 			default:
1392 				delay = filedelay;
1393 			}
1394 			vn_syncer_add_to_worklist(newvp, delay);
1395 		}
1396 		bp->b_xflags |= BX_VNDIRTY;
1397 		tbp = TAILQ_FIRST(listheadp);
1398 		if (tbp == NULL ||
1399 		    bp->b_lblkno == 0 ||
1400 		    (bp->b_lblkno > 0 && tbp->b_lblkno < 0) ||
1401 		    (bp->b_lblkno > 0 && bp->b_lblkno < tbp->b_lblkno)) {
1402 			TAILQ_INSERT_HEAD(listheadp, bp, b_vnbufs);
1403 			++reassignbufsortgood;
1404 		} else if (bp->b_lblkno < 0) {
1405 			TAILQ_INSERT_TAIL(listheadp, bp, b_vnbufs);
1406 			++reassignbufsortgood;
1407 		} else if (reassignbufmethod == 1) {
1408 			/*
1409 			 * New sorting algorithm, only handle sequential case,
1410 			 * otherwise append to end (but before metadata)
1411 			 */
1412 			if ((tbp = gbincore(newvp, bp->b_lblkno - 1)) != NULL &&
1413 			    (tbp->b_xflags & BX_VNDIRTY)) {
1414 				/*
1415 				 * Found the best place to insert the buffer
1416 				 */
1417 				TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
1418 				++reassignbufsortgood;
1419 			} else {
1420 				/*
1421 				 * Missed, append to end, but before meta-data.
1422 				 * We know that the head buffer in the list is
1423 				 * not meta-data due to prior conditionals.
1424 				 *
1425 				 * Indirect effects:  NFS second stage write
1426 				 * tends to wind up here, giving maximum
1427 				 * distance between the unstable write and the
1428 				 * commit rpc.
1429 				 */
1430 				tbp = TAILQ_LAST(listheadp, buflists);
1431 				while (tbp && tbp->b_lblkno < 0)
1432 					tbp = TAILQ_PREV(tbp, buflists, b_vnbufs);
1433 				TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
1434 				++reassignbufsortbad;
1435 			}
1436 		} else {
1437 			/*
1438 			 * Old sorting algorithm, scan queue and insert
1439 			 */
1440 			struct buf *ttbp;
1441 			while ((ttbp = TAILQ_NEXT(tbp, b_vnbufs)) &&
1442 			    (ttbp->b_lblkno < bp->b_lblkno)) {
1443 				++reassignbufloops;
1444 				tbp = ttbp;
1445 			}
1446 			TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
1447 		}
1448 	} else {
1449 		bp->b_xflags |= BX_VNCLEAN;
1450 		TAILQ_INSERT_TAIL(&newvp->v_cleanblkhd, bp, b_vnbufs);
1451 		if ((newvp->v_flag & VONWORKLST) &&
1452 		    TAILQ_EMPTY(&newvp->v_dirtyblkhd)) {
1453 			newvp->v_flag &= ~VONWORKLST;
1454 			LIST_REMOVE(newvp, v_synclist);
1455 		}
1456 	}
1457 	if (bp->b_vp != newvp) {
1458 		bp->b_vp = newvp;
1459 		vhold(bp->b_vp);
1460 	}
1461 	splx(s);
1462 }
1463 
1464 /*
1465  * Create a vnode for a block device.
1466  * Used for mounting the root file system.
1467  */
1468 int
1469 bdevvp(dev, vpp)
1470 	dev_t dev;
1471 	struct vnode **vpp;
1472 {
1473 	struct vnode *vp;
1474 	struct vnode *nvp;
1475 	int error;
1476 
1477 	if (dev == NODEV) {
1478 		*vpp = NULLVP;
1479 		return (ENXIO);
1480 	}
1481 	error = getnewvnode(VT_NON, (struct mount *)0, spec_vnodeop_p, &nvp);
1482 	if (error) {
1483 		*vpp = NULLVP;
1484 		return (error);
1485 	}
1486 	vp = nvp;
1487 	vp->v_type = VBLK;
1488 	addalias(vp, dev);
1489 	*vpp = vp;
1490 	return (0);
1491 }
1492 
1493 /*
1494  * Add a vnode to the alias list hung off the dev_t.
1495  *
1496  * The reason for this gunk is that multiple vnodes can reference
1497  * the same physical device, so checking vp->v_usecount to see
1498  * how many users there are is inadequate; the v_usecount for
1499  * the vnodes need to be accumulated.  vcount() does that.
1500  */
1501 void
1502 addaliasu(struct vnode *nvp, udev_t nvp_rdev)
1503 {
1504 	dev_t dev;
1505 
1506 	if (nvp->v_type != VBLK && nvp->v_type != VCHR)
1507 		panic("addaliasu on non-special vnode");
1508 	dev = udev2dev(nvp_rdev, nvp->v_type == VBLK ? 1 : 0);
1509 	if (dev != NODEV) {
1510 		nvp->v_rdev = dev;
1511 		addalias(nvp, dev);
1512 	} else
1513 		nvp->v_rdev = NULL;
1514 }
1515 
1516 void
1517 addalias(struct vnode *nvp, dev_t dev)
1518 {
1519 
1520 	if (nvp->v_type != VBLK && nvp->v_type != VCHR)
1521 		panic("addalias on non-special vnode");
1522 
1523 	nvp->v_rdev = dev;
1524 	lwkt_gettoken(&spechash_token);
1525 	SLIST_INSERT_HEAD(&dev->si_hlist, nvp, v_specnext);
1526 	lwkt_reltoken(&spechash_token);
1527 }
1528 
1529 /*
1530  * Grab a particular vnode from the free list, increment its
1531  * reference count and lock it. The vnode lock bit is set if the
1532  * vnode is being eliminated in vgone. The process is awakened
1533  * when the transition is completed, and an error returned to
1534  * indicate that the vnode is no longer usable (possibly having
1535  * been changed to a new file system type).
1536  */
1537 int
1538 vget(vp, flags, td)
1539 	struct vnode *vp;
1540 	int flags;
1541 	struct thread *td;
1542 {
1543 	int error;
1544 
1545 	/*
1546 	 * If the vnode is in the process of being cleaned out for
1547 	 * another use, we wait for the cleaning to finish and then
1548 	 * return failure. Cleaning is determined by checking that
1549 	 * the VXLOCK flag is set.
1550 	 */
1551 	if (vp->v_flag & VXLOCK) {
1552 		if (vp->v_vxproc == curproc) {
1553 #if 0
1554 			/* this can now occur in normal operation */
1555 			log(LOG_INFO, "VXLOCK interlock avoided\n");
1556 #endif
1557 		} else {
1558 			vp->v_flag |= VXWANT;
1559 			tsleep((caddr_t)vp, 0, "vget", 0);
1560 			return (ENOENT);
1561 		}
1562 	}
1563 
1564 	/*
1565 	 * Bump v_usecount to prevent the vnode from being cleaned.  If the
1566 	 * vnode gets cleaned unexpectedly we could wind up calling lockmgr
1567 	 * on a lock embedded in an inode which is then ripped out from
1568 	 * it.
1569 	 */
1570 	vp->v_usecount++;	/* XXX MP */
1571 
1572 	if ((flags & LK_INTERLOCK) == 0) {
1573 		lwkt_gettoken(&vp->v_interlock);
1574 	}
1575 
1576 	if (VSHOULDBUSY(vp))
1577 		vbusy(vp);
1578 	if (flags & LK_TYPE_MASK) {
1579 		if ((error = vn_lock(vp, flags | LK_INTERLOCK, td)) != 0) {
1580 			/*
1581 			 * must expand vrele here because we do not want
1582 			 * to call VOP_INACTIVE if the reference count
1583 			 * drops back to zero since it was never really
1584 			 * active. We must remove it from the free list
1585 			 * before sleeping so that multiple processes do
1586 			 * not try to recycle it.
1587 			 */
1588 			lwkt_gettoken(&vp->v_interlock);
1589 			vp->v_usecount--;
1590 			if (VSHOULDFREE(vp))
1591 				vfree(vp);
1592 			else
1593 				vlruvp(vp);
1594 			lwkt_reltoken(&vp->v_interlock);
1595 		}
1596 		return (error);
1597 	}
1598 	lwkt_reltoken(&vp->v_interlock);
1599 	return (0);
1600 }
1601 
1602 void
1603 vref(struct vnode *vp)
1604 {
1605 	vp->v_usecount++;	/* XXX MP */
1606 }
1607 
1608 /*
1609  * Vnode put/release.
1610  * If count drops to zero, call inactive routine and return to freelist.
1611  */
1612 void
1613 vrele(struct vnode *vp)
1614 {
1615 	struct thread *td = curthread;	/* XXX */
1616 
1617 	KASSERT(vp != NULL, ("vrele: null vp"));
1618 
1619 	lwkt_gettoken(&vp->v_interlock);
1620 
1621 	if (vp->v_usecount > 1) {
1622 
1623 		vp->v_usecount--;
1624 		lwkt_reltoken(&vp->v_interlock);
1625 
1626 		return;
1627 	}
1628 
1629 	if (vp->v_usecount == 1) {
1630 		vp->v_usecount--;
1631 		/*
1632 		 * We must call VOP_INACTIVE with the node locked.
1633 		 * If we are doing a vpu, the node is already locked,
1634 		 * but, in the case of vrele, we must explicitly lock
1635 		 * the vnode before calling VOP_INACTIVE
1636 		 */
1637 
1638 		if (vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK, td) == 0)
1639 			VOP_INACTIVE(vp, td);
1640 		if (VSHOULDFREE(vp))
1641 			vfree(vp);
1642 		else
1643 			vlruvp(vp);
1644 	} else {
1645 #ifdef DIAGNOSTIC
1646 		vprint("vrele: negative ref count", vp);
1647 		lwkt_reltoken(&vp->v_interlock);
1648 #endif
1649 		panic("vrele: negative ref cnt");
1650 	}
1651 }
1652 
1653 void
1654 vput(struct vnode *vp)
1655 {
1656 	struct thread *td = curthread;	/* XXX */
1657 
1658 	KASSERT(vp != NULL, ("vput: null vp"));
1659 
1660 	lwkt_gettoken(&vp->v_interlock);
1661 
1662 	if (vp->v_usecount > 1) {
1663 		vp->v_usecount--;
1664 		VOP_UNLOCK(vp, LK_INTERLOCK, td);
1665 		return;
1666 	}
1667 
1668 	if (vp->v_usecount == 1) {
1669 		vp->v_usecount--;
1670 		/*
1671 		 * We must call VOP_INACTIVE with the node locked.
1672 		 * If we are doing a vpu, the node is already locked,
1673 		 * so we just need to release the vnode mutex.
1674 		 */
1675 		lwkt_reltoken(&vp->v_interlock);
1676 		VOP_INACTIVE(vp, td);
1677 		if (VSHOULDFREE(vp))
1678 			vfree(vp);
1679 		else
1680 			vlruvp(vp);
1681 	} else {
1682 #ifdef DIAGNOSTIC
1683 		vprint("vput: negative ref count", vp);
1684 #endif
1685 		panic("vput: negative ref cnt");
1686 	}
1687 }
1688 
1689 /*
1690  * Somebody doesn't want the vnode recycled.
1691  */
1692 void
1693 vhold(vp)
1694 	struct vnode *vp;
1695 {
1696 	int s;
1697 
1698   	s = splbio();
1699 	vp->v_holdcnt++;
1700 	if (VSHOULDBUSY(vp))
1701 		vbusy(vp);
1702 	splx(s);
1703 }
1704 
1705 /*
1706  * One less who cares about this vnode.
1707  */
1708 void
1709 vdrop(vp)
1710 	struct vnode *vp;
1711 {
1712 	int s;
1713 
1714 	s = splbio();
1715 	if (vp->v_holdcnt <= 0)
1716 		panic("vdrop: holdcnt");
1717 	vp->v_holdcnt--;
1718 	if (VSHOULDFREE(vp))
1719 		vfree(vp);
1720 	splx(s);
1721 }
1722 
1723 /*
1724  * Remove any vnodes in the vnode table belonging to mount point mp.
1725  *
1726  * If FORCECLOSE is not specified, there should not be any active ones,
1727  * return error if any are found (nb: this is a user error, not a
1728  * system error). If FORCECLOSE is specified, detach any active vnodes
1729  * that are found.
1730  *
1731  * If WRITECLOSE is set, only flush out regular file vnodes open for
1732  * writing.
1733  *
1734  * SKIPSYSTEM causes any vnodes marked VSYSTEM to be skipped.
1735  *
1736  * `rootrefs' specifies the base reference count for the root vnode
1737  * of this filesystem. The root vnode is considered busy if its
1738  * v_usecount exceeds this value. On a successful return, vflush()
1739  * will call vrele() on the root vnode exactly rootrefs times.
1740  * If the SKIPSYSTEM or WRITECLOSE flags are specified, rootrefs must
1741  * be zero.
1742  */
1743 #ifdef DIAGNOSTIC
1744 static int busyprt = 0;		/* print out busy vnodes */
1745 SYSCTL_INT(_debug, OID_AUTO, busyprt, CTLFLAG_RW, &busyprt, 0, "");
1746 #endif
1747 
1748 int
1749 vflush(mp, rootrefs, flags)
1750 	struct mount *mp;
1751 	int rootrefs;
1752 	int flags;
1753 {
1754 	struct thread *td = curthread;	/* XXX */
1755 	struct vnode *vp, *nvp, *rootvp = NULL;
1756 	struct vattr vattr;
1757 	int busy = 0, error;
1758 
1759 	if (rootrefs > 0) {
1760 		KASSERT((flags & (SKIPSYSTEM | WRITECLOSE)) == 0,
1761 		    ("vflush: bad args"));
1762 		/*
1763 		 * Get the filesystem root vnode. We can vput() it
1764 		 * immediately, since with rootrefs > 0, it won't go away.
1765 		 */
1766 		if ((error = VFS_ROOT(mp, &rootvp)) != 0)
1767 			return (error);
1768 		vput(rootvp);
1769 	}
1770 	lwkt_gettoken(&mntvnode_token);
1771 loop:
1772 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp; vp = nvp) {
1773 		/*
1774 		 * Make sure this vnode wasn't reclaimed in getnewvnode().
1775 		 * Start over if it has (it won't be on the list anymore).
1776 		 */
1777 		if (vp->v_mount != mp)
1778 			goto loop;
1779 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
1780 
1781 		lwkt_gettoken(&vp->v_interlock);
1782 		/*
1783 		 * Skip over a vnodes marked VSYSTEM.
1784 		 */
1785 		if ((flags & SKIPSYSTEM) && (vp->v_flag & VSYSTEM)) {
1786 			lwkt_reltoken(&vp->v_interlock);
1787 			continue;
1788 		}
1789 		/*
1790 		 * If WRITECLOSE is set, flush out unlinked but still open
1791 		 * files (even if open only for reading) and regular file
1792 		 * vnodes open for writing.
1793 		 */
1794 		if ((flags & WRITECLOSE) &&
1795 		    (vp->v_type == VNON ||
1796 		    (VOP_GETATTR(vp, &vattr, td) == 0 &&
1797 		    vattr.va_nlink > 0)) &&
1798 		    (vp->v_writecount == 0 || vp->v_type != VREG)) {
1799 			lwkt_reltoken(&vp->v_interlock);
1800 			continue;
1801 		}
1802 
1803 		/*
1804 		 * With v_usecount == 0, all we need to do is clear out the
1805 		 * vnode data structures and we are done.
1806 		 */
1807 		if (vp->v_usecount == 0) {
1808 			lwkt_reltoken(&mntvnode_token);
1809 			vgonel(vp, td);
1810 			lwkt_gettoken(&mntvnode_token);
1811 			continue;
1812 		}
1813 
1814 		/*
1815 		 * If FORCECLOSE is set, forcibly close the vnode. For block
1816 		 * or character devices, revert to an anonymous device. For
1817 		 * all other files, just kill them.
1818 		 */
1819 		if (flags & FORCECLOSE) {
1820 			lwkt_reltoken(&mntvnode_token);
1821 			if (vp->v_type != VBLK && vp->v_type != VCHR) {
1822 				vgonel(vp, td);
1823 			} else {
1824 				vclean(vp, 0, td);
1825 				vp->v_op = spec_vnodeop_p;
1826 				insmntque(vp, (struct mount *) 0);
1827 			}
1828 			lwkt_gettoken(&mntvnode_token);
1829 			continue;
1830 		}
1831 #ifdef DIAGNOSTIC
1832 		if (busyprt)
1833 			vprint("vflush: busy vnode", vp);
1834 #endif
1835 		lwkt_reltoken(&vp->v_interlock);
1836 		busy++;
1837 	}
1838 	lwkt_reltoken(&mntvnode_token);
1839 	if (rootrefs > 0 && (flags & FORCECLOSE) == 0) {
1840 		/*
1841 		 * If just the root vnode is busy, and if its refcount
1842 		 * is equal to `rootrefs', then go ahead and kill it.
1843 		 */
1844 		lwkt_gettoken(&rootvp->v_interlock);
1845 		KASSERT(busy > 0, ("vflush: not busy"));
1846 		KASSERT(rootvp->v_usecount >= rootrefs, ("vflush: rootrefs"));
1847 		if (busy == 1 && rootvp->v_usecount == rootrefs) {
1848 			vgonel(rootvp, td);
1849 			busy = 0;
1850 		} else
1851 			lwkt_reltoken(&rootvp->v_interlock);
1852 	}
1853 	if (busy)
1854 		return (EBUSY);
1855 	for (; rootrefs > 0; rootrefs--)
1856 		vrele(rootvp);
1857 	return (0);
1858 }
1859 
1860 /*
1861  * We do not want to recycle the vnode too quickly.
1862  *
1863  * XXX we can't move vp's around the nvnodelist without really screwing
1864  * up the efficiency of filesystem SYNC and friends.  This code is
1865  * disabled until we fix the syncing code's scanning algorithm.
1866  */
1867 static void
1868 vlruvp(struct vnode *vp)
1869 {
1870 #if 0
1871 	struct mount *mp;
1872 
1873 	if ((mp = vp->v_mount) != NULL) {
1874 		lwkt_gettoken(&mntvnode_token);
1875 		TAILQ_REMOVE(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1876 		TAILQ_INSERT_TAIL(&mp->mnt_nvnodelist, vp, v_nmntvnodes);
1877 		lwkt_reltoken(&mntvnode_token);
1878 	}
1879 #endif
1880 }
1881 
1882 /*
1883  * Disassociate the underlying file system from a vnode.
1884  */
1885 static void
1886 vclean(struct vnode *vp, int flags, struct thread *td)
1887 {
1888 	int active;
1889 
1890 	/*
1891 	 * Check to see if the vnode is in use. If so we have to reference it
1892 	 * before we clean it out so that its count cannot fall to zero and
1893 	 * generate a race against ourselves to recycle it.
1894 	 */
1895 	if ((active = vp->v_usecount))
1896 		vp->v_usecount++;
1897 
1898 	/*
1899 	 * Prevent the vnode from being recycled or brought into use while we
1900 	 * clean it out.
1901 	 */
1902 	if (vp->v_flag & VXLOCK)
1903 		panic("vclean: deadlock");
1904 	vp->v_flag |= VXLOCK;
1905 	vp->v_vxproc = curproc;
1906 	/*
1907 	 * Even if the count is zero, the VOP_INACTIVE routine may still
1908 	 * have the object locked while it cleans it out. The VOP_LOCK
1909 	 * ensures that the VOP_INACTIVE routine is done with its work.
1910 	 * For active vnodes, it ensures that no other activity can
1911 	 * occur while the underlying object is being cleaned out.
1912 	 */
1913 	VOP_LOCK(vp, LK_DRAIN | LK_INTERLOCK, td);
1914 
1915 	/*
1916 	 * Clean out any buffers associated with the vnode.
1917 	 */
1918 	vinvalbuf(vp, V_SAVE, td, 0, 0);
1919 
1920 	VOP_DESTROYVOBJECT(vp);
1921 
1922 	/*
1923 	 * If purging an active vnode, it must be closed and
1924 	 * deactivated before being reclaimed. Note that the
1925 	 * VOP_INACTIVE will unlock the vnode.
1926 	 */
1927 	if (active) {
1928 		if (flags & DOCLOSE)
1929 			VOP_CLOSE(vp, FNONBLOCK, td);
1930 		VOP_INACTIVE(vp, td);
1931 	} else {
1932 		/*
1933 		 * Any other processes trying to obtain this lock must first
1934 		 * wait for VXLOCK to clear, then call the new lock operation.
1935 		 */
1936 		VOP_UNLOCK(vp, 0, td);
1937 	}
1938 	/*
1939 	 * Reclaim the vnode.
1940 	 */
1941 	if (VOP_RECLAIM(vp, td))
1942 		panic("vclean: cannot reclaim");
1943 
1944 	if (active) {
1945 		/*
1946 		 * Inline copy of vrele() since VOP_INACTIVE
1947 		 * has already been called.
1948 		 */
1949 		lwkt_gettoken(&vp->v_interlock);
1950 		if (--vp->v_usecount <= 0) {
1951 #ifdef DIAGNOSTIC
1952 			if (vp->v_usecount < 0 || vp->v_writecount != 0) {
1953 				vprint("vclean: bad ref count", vp);
1954 				panic("vclean: ref cnt");
1955 			}
1956 #endif
1957 			vfree(vp);
1958 		}
1959 		lwkt_reltoken(&vp->v_interlock);
1960 	}
1961 
1962 	cache_purge(vp);
1963 	vp->v_vnlock = NULL;
1964 
1965 	if (VSHOULDFREE(vp))
1966 		vfree(vp);
1967 
1968 	/*
1969 	 * Done with purge, notify sleepers of the grim news.
1970 	 */
1971 	vp->v_op = dead_vnodeop_p;
1972 	vn_pollgone(vp);
1973 	vp->v_tag = VT_NON;
1974 	vp->v_flag &= ~VXLOCK;
1975 	vp->v_vxproc = NULL;
1976 	if (vp->v_flag & VXWANT) {
1977 		vp->v_flag &= ~VXWANT;
1978 		wakeup((caddr_t) vp);
1979 	}
1980 }
1981 
1982 /*
1983  * Eliminate all activity associated with the requested vnode
1984  * and with all vnodes aliased to the requested vnode.
1985  */
1986 int
1987 vop_revoke(ap)
1988 	struct vop_revoke_args /* {
1989 		struct vnode *a_vp;
1990 		int a_flags;
1991 	} */ *ap;
1992 {
1993 	struct vnode *vp, *vq;
1994 	dev_t dev;
1995 
1996 	KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke"));
1997 
1998 	vp = ap->a_vp;
1999 	/*
2000 	 * If a vgone (or vclean) is already in progress,
2001 	 * wait until it is done and return.
2002 	 */
2003 	if (vp->v_flag & VXLOCK) {
2004 		vp->v_flag |= VXWANT;
2005 		lwkt_reltoken(&vp->v_interlock);
2006 		tsleep((caddr_t)vp, 0, "vop_revokeall", 0);
2007 		return (0);
2008 	}
2009 	dev = vp->v_rdev;
2010 	for (;;) {
2011 		lwkt_gettoken(&spechash_token);
2012 		vq = SLIST_FIRST(&dev->si_hlist);
2013 		lwkt_reltoken(&spechash_token);
2014 		if (!vq)
2015 			break;
2016 		vgone(vq);
2017 	}
2018 	return (0);
2019 }
2020 
2021 /*
2022  * Recycle an unused vnode to the front of the free list.
2023  * Release the passed interlock if the vnode will be recycled.
2024  */
2025 int
2026 vrecycle(struct vnode *vp, struct lwkt_token *inter_lkp, struct thread *td)
2027 {
2028 	lwkt_gettoken(&vp->v_interlock);
2029 	if (vp->v_usecount == 0) {
2030 		if (inter_lkp) {
2031 			lwkt_reltoken(inter_lkp);
2032 		}
2033 		vgonel(vp, td);
2034 		return (1);
2035 	}
2036 	lwkt_reltoken(&vp->v_interlock);
2037 	return (0);
2038 }
2039 
2040 /*
2041  * Eliminate all activity associated with a vnode
2042  * in preparation for reuse.
2043  */
2044 void
2045 vgone(struct vnode *vp)
2046 {
2047 	struct thread *td = curthread;	/* XXX */
2048 
2049 	lwkt_gettoken(&vp->v_interlock);
2050 	vgonel(vp, td);
2051 }
2052 
2053 /*
2054  * vgone, with the vp interlock held.
2055  */
2056 void
2057 vgonel(struct vnode *vp, struct thread *td)
2058 {
2059 	int s;
2060 
2061 	/*
2062 	 * If a vgone (or vclean) is already in progress,
2063 	 * wait until it is done and return.
2064 	 */
2065 	if (vp->v_flag & VXLOCK) {
2066 		vp->v_flag |= VXWANT;
2067 		lwkt_reltoken(&vp->v_interlock);
2068 		tsleep((caddr_t)vp, 0, "vgone", 0);
2069 		return;
2070 	}
2071 
2072 	/*
2073 	 * Clean out the filesystem specific data.
2074 	 */
2075 	vclean(vp, DOCLOSE, td);
2076 	lwkt_gettoken(&vp->v_interlock);
2077 
2078 	/*
2079 	 * Delete from old mount point vnode list, if on one.
2080 	 */
2081 	if (vp->v_mount != NULL)
2082 		insmntque(vp, (struct mount *)0);
2083 	/*
2084 	 * If special device, remove it from special device alias list
2085 	 * if it is on one.
2086 	 */
2087 	if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_rdev != NULL) {
2088 		lwkt_gettoken(&spechash_token);
2089 		SLIST_REMOVE(&vp->v_hashchain, vp, vnode, v_specnext);
2090 		freedev(vp->v_rdev);
2091 		lwkt_reltoken(&spechash_token);
2092 		vp->v_rdev = NULL;
2093 	}
2094 
2095 	/*
2096 	 * If it is on the freelist and not already at the head,
2097 	 * move it to the head of the list. The test of the
2098 	 * VDOOMED flag and the reference count of zero is because
2099 	 * it will be removed from the free list by getnewvnode,
2100 	 * but will not have its reference count incremented until
2101 	 * after calling vgone. If the reference count were
2102 	 * incremented first, vgone would (incorrectly) try to
2103 	 * close the previous instance of the underlying object.
2104 	 */
2105 	if (vp->v_usecount == 0 && !(vp->v_flag & VDOOMED)) {
2106 		s = splbio();
2107 		lwkt_gettoken(&vnode_free_list_token);
2108 		if (vp->v_flag & VFREE)
2109 			TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
2110 		else
2111 			freevnodes++;
2112 		vp->v_flag |= VFREE;
2113 		TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
2114 		lwkt_reltoken(&vnode_free_list_token);
2115 		splx(s);
2116 	}
2117 
2118 	vp->v_type = VBAD;
2119 	lwkt_reltoken(&vp->v_interlock);
2120 }
2121 
2122 /*
2123  * Lookup a vnode by device number.
2124  */
2125 int
2126 vfinddev(dev, type, vpp)
2127 	dev_t dev;
2128 	enum vtype type;
2129 	struct vnode **vpp;
2130 {
2131 	struct vnode *vp;
2132 
2133 	lwkt_gettoken(&spechash_token);
2134 	SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) {
2135 		if (type == vp->v_type) {
2136 			*vpp = vp;
2137 			lwkt_reltoken(&spechash_token);
2138 			return (1);
2139 		}
2140 	}
2141 	lwkt_reltoken(&spechash_token);
2142 	return (0);
2143 }
2144 
2145 /*
2146  * Calculate the total number of references to a special device.
2147  */
2148 int
2149 vcount(vp)
2150 	struct vnode *vp;
2151 {
2152 	struct vnode *vq;
2153 	int count;
2154 
2155 	count = 0;
2156 	lwkt_gettoken(&spechash_token);
2157 	SLIST_FOREACH(vq, &vp->v_hashchain, v_specnext)
2158 		count += vq->v_usecount;
2159 	lwkt_reltoken(&spechash_token);
2160 	return (count);
2161 }
2162 
2163 /*
2164  * Same as above, but using the dev_t as argument
2165  */
2166 
2167 int
2168 count_dev(dev)
2169 	dev_t dev;
2170 {
2171 	struct vnode *vp;
2172 
2173 	vp = SLIST_FIRST(&dev->si_hlist);
2174 	if (vp == NULL)
2175 		return (0);
2176 	return(vcount(vp));
2177 }
2178 
2179 /*
2180  * Print out a description of a vnode.
2181  */
2182 static char *typename[] =
2183 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"};
2184 
2185 void
2186 vprint(label, vp)
2187 	char *label;
2188 	struct vnode *vp;
2189 {
2190 	char buf[96];
2191 
2192 	if (label != NULL)
2193 		printf("%s: %p: ", label, (void *)vp);
2194 	else
2195 		printf("%p: ", (void *)vp);
2196 	printf("type %s, usecount %d, writecount %d, refcount %d,",
2197 	    typename[vp->v_type], vp->v_usecount, vp->v_writecount,
2198 	    vp->v_holdcnt);
2199 	buf[0] = '\0';
2200 	if (vp->v_flag & VROOT)
2201 		strcat(buf, "|VROOT");
2202 	if (vp->v_flag & VTEXT)
2203 		strcat(buf, "|VTEXT");
2204 	if (vp->v_flag & VSYSTEM)
2205 		strcat(buf, "|VSYSTEM");
2206 	if (vp->v_flag & VXLOCK)
2207 		strcat(buf, "|VXLOCK");
2208 	if (vp->v_flag & VXWANT)
2209 		strcat(buf, "|VXWANT");
2210 	if (vp->v_flag & VBWAIT)
2211 		strcat(buf, "|VBWAIT");
2212 	if (vp->v_flag & VDOOMED)
2213 		strcat(buf, "|VDOOMED");
2214 	if (vp->v_flag & VFREE)
2215 		strcat(buf, "|VFREE");
2216 	if (vp->v_flag & VOBJBUF)
2217 		strcat(buf, "|VOBJBUF");
2218 	if (buf[0] != '\0')
2219 		printf(" flags (%s)", &buf[1]);
2220 	if (vp->v_data == NULL) {
2221 		printf("\n");
2222 	} else {
2223 		printf("\n\t");
2224 		VOP_PRINT(vp);
2225 	}
2226 }
2227 
2228 #ifdef DDB
2229 #include <ddb/ddb.h>
2230 /*
2231  * List all of the locked vnodes in the system.
2232  * Called when debugging the kernel.
2233  */
2234 DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
2235 {
2236 	struct thread *td = curthread;	/* XXX */
2237 	struct mount *mp, *nmp;
2238 	struct vnode *vp;
2239 
2240 	printf("Locked vnodes\n");
2241 	lwkt_gettoken(&mountlist_token);
2242 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
2243 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_token, td)) {
2244 			nmp = TAILQ_NEXT(mp, mnt_list);
2245 			continue;
2246 		}
2247 		TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
2248 			if (VOP_ISLOCKED(vp, NULL))
2249 				vprint((char *)0, vp);
2250 		}
2251 		lwkt_gettoken(&mountlist_token);
2252 		nmp = TAILQ_NEXT(mp, mnt_list);
2253 		vfs_unbusy(mp, td);
2254 	}
2255 	lwkt_reltoken(&mountlist_token);
2256 }
2257 #endif
2258 
2259 /*
2260  * Top level filesystem related information gathering.
2261  */
2262 static int	sysctl_ovfs_conf (SYSCTL_HANDLER_ARGS);
2263 
2264 static int
2265 vfs_sysctl(SYSCTL_HANDLER_ARGS)
2266 {
2267 	int *name = (int *)arg1 - 1;	/* XXX */
2268 	u_int namelen = arg2 + 1;	/* XXX */
2269 	struct vfsconf *vfsp;
2270 
2271 #if 1 || defined(COMPAT_PRELITE2)
2272 	/* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
2273 	if (namelen == 1)
2274 		return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
2275 #endif
2276 
2277 #ifdef notyet
2278 	/* all sysctl names at this level are at least name and field */
2279 	if (namelen < 2)
2280 		return (ENOTDIR);		/* overloaded */
2281 	if (name[0] != VFS_GENERIC) {
2282 		for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
2283 			if (vfsp->vfc_typenum == name[0])
2284 				break;
2285 		if (vfsp == NULL)
2286 			return (EOPNOTSUPP);
2287 		return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1,
2288 		    oldp, oldlenp, newp, newlen, p));
2289 	}
2290 #endif
2291 	switch (name[1]) {
2292 	case VFS_MAXTYPENUM:
2293 		if (namelen != 2)
2294 			return (ENOTDIR);
2295 		return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
2296 	case VFS_CONF:
2297 		if (namelen != 3)
2298 			return (ENOTDIR);	/* overloaded */
2299 		for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
2300 			if (vfsp->vfc_typenum == name[2])
2301 				break;
2302 		if (vfsp == NULL)
2303 			return (EOPNOTSUPP);
2304 		return (SYSCTL_OUT(req, vfsp, sizeof *vfsp));
2305 	}
2306 	return (EOPNOTSUPP);
2307 }
2308 
2309 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl,
2310 	"Generic filesystem");
2311 
2312 #if 1 || defined(COMPAT_PRELITE2)
2313 
2314 static int
2315 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
2316 {
2317 	int error;
2318 	struct vfsconf *vfsp;
2319 	struct ovfsconf ovfs;
2320 
2321 	for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
2322 		ovfs.vfc_vfsops = vfsp->vfc_vfsops;	/* XXX used as flag */
2323 		strcpy(ovfs.vfc_name, vfsp->vfc_name);
2324 		ovfs.vfc_index = vfsp->vfc_typenum;
2325 		ovfs.vfc_refcount = vfsp->vfc_refcount;
2326 		ovfs.vfc_flags = vfsp->vfc_flags;
2327 		error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
2328 		if (error)
2329 			return error;
2330 	}
2331 	return 0;
2332 }
2333 
2334 #endif /* 1 || COMPAT_PRELITE2 */
2335 
2336 #if 0
2337 #define KINFO_VNODESLOP	10
2338 /*
2339  * Dump vnode list (via sysctl).
2340  * Copyout address of vnode followed by vnode.
2341  */
2342 /* ARGSUSED */
2343 static int
2344 sysctl_vnode(SYSCTL_HANDLER_ARGS)
2345 {
2346 	struct proc *p = curproc;	/* XXX */
2347 	struct mount *mp, *nmp;
2348 	struct vnode *nvp, *vp;
2349 	int error;
2350 
2351 #define VPTRSZ	sizeof (struct vnode *)
2352 #define VNODESZ	sizeof (struct vnode)
2353 
2354 	req->lock = 0;
2355 	if (!req->oldptr) /* Make an estimate */
2356 		return (SYSCTL_OUT(req, 0,
2357 			(numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ)));
2358 
2359 	lwkt_gettoken(&mountlist_token);
2360 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
2361 		if (vfs_busy(mp, LK_NOWAIT, &mountlist_token, p)) {
2362 			nmp = TAILQ_NEXT(mp, mnt_list);
2363 			continue;
2364 		}
2365 again:
2366 		lwkt_gettoken(&mntvnode_token);
2367 		for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
2368 		     vp != NULL;
2369 		     vp = nvp) {
2370 			/*
2371 			 * Check that the vp is still associated with
2372 			 * this filesystem.  RACE: could have been
2373 			 * recycled onto the same filesystem.
2374 			 */
2375 			if (vp->v_mount != mp) {
2376 				lwkt_reltoken(&mntvnode_token);
2377 				goto again;
2378 			}
2379 			nvp = TAILQ_NEXT(vp, v_nmntvnodes);
2380 			lwkt_reltoken(&mntvnode_token);
2381 			if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) ||
2382 			    (error = SYSCTL_OUT(req, vp, VNODESZ)))
2383 				return (error);
2384 			lwkt_gettoken(&mntvnode_token);
2385 		}
2386 		lwkt_reltoken(&mntvnode_token);
2387 		lwkt_gettoken(&mountlist_token);
2388 		nmp = TAILQ_NEXT(mp, mnt_list);
2389 		vfs_unbusy(mp, p);
2390 	}
2391 	lwkt_reltoken(&mountlist_token);
2392 
2393 	return (0);
2394 }
2395 #endif
2396 
2397 /*
2398  * XXX
2399  * Exporting the vnode list on large systems causes them to crash.
2400  * Exporting the vnode list on medium systems causes sysctl to coredump.
2401  */
2402 #if 0
2403 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
2404 	0, 0, sysctl_vnode, "S,vnode", "");
2405 #endif
2406 
2407 /*
2408  * Check to see if a filesystem is mounted on a block device.
2409  */
2410 int
2411 vfs_mountedon(vp)
2412 	struct vnode *vp;
2413 {
2414 
2415 	if (vp->v_specmountpoint != NULL)
2416 		return (EBUSY);
2417 	return (0);
2418 }
2419 
2420 /*
2421  * Unmount all filesystems. The list is traversed in reverse order
2422  * of mounting to avoid dependencies.
2423  */
2424 void
2425 vfs_unmountall()
2426 {
2427 	struct mount *mp;
2428 	struct thread *td = curthread;
2429 	int error;
2430 
2431 	if (td->td_proc == NULL)
2432 		td = initproc->p_thread;	/* XXX XXX use proc0 instead? */
2433 
2434 	/*
2435 	 * Since this only runs when rebooting, it is not interlocked.
2436 	 */
2437 	while(!TAILQ_EMPTY(&mountlist)) {
2438 		mp = TAILQ_LAST(&mountlist, mntlist);
2439 		error = dounmount(mp, MNT_FORCE, td);
2440 		if (error) {
2441 			TAILQ_REMOVE(&mountlist, mp, mnt_list);
2442 			printf("unmount of %s failed (",
2443 			    mp->mnt_stat.f_mntonname);
2444 			if (error == EBUSY)
2445 				printf("BUSY)\n");
2446 			else
2447 				printf("%d)\n", error);
2448 		} else {
2449 			/* The unmount has removed mp from the mountlist */
2450 		}
2451 	}
2452 }
2453 
2454 /*
2455  * Build hash lists of net addresses and hang them off the mount point.
2456  * Called by ufs_mount() to set up the lists of export addresses.
2457  */
2458 static int
2459 vfs_hang_addrlist(mp, nep, argp)
2460 	struct mount *mp;
2461 	struct netexport *nep;
2462 	struct export_args *argp;
2463 {
2464 	struct netcred *np;
2465 	struct radix_node_head *rnh;
2466 	int i;
2467 	struct radix_node *rn;
2468 	struct sockaddr *saddr, *smask = 0;
2469 	struct domain *dom;
2470 	int error;
2471 
2472 	if (argp->ex_addrlen == 0) {
2473 		if (mp->mnt_flag & MNT_DEFEXPORTED)
2474 			return (EPERM);
2475 		np = &nep->ne_defexported;
2476 		np->netc_exflags = argp->ex_flags;
2477 		np->netc_anon = argp->ex_anon;
2478 		np->netc_anon.cr_ref = 1;
2479 		mp->mnt_flag |= MNT_DEFEXPORTED;
2480 		return (0);
2481 	}
2482 
2483 	if (argp->ex_addrlen < 0 || argp->ex_addrlen > MLEN)
2484 		return (EINVAL);
2485 	if (argp->ex_masklen < 0 || argp->ex_masklen > MLEN)
2486 		return (EINVAL);
2487 
2488 	i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
2489 	np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK);
2490 	bzero((caddr_t) np, i);
2491 	saddr = (struct sockaddr *) (np + 1);
2492 	if ((error = copyin(argp->ex_addr, (caddr_t) saddr, argp->ex_addrlen)))
2493 		goto out;
2494 	if (saddr->sa_len > argp->ex_addrlen)
2495 		saddr->sa_len = argp->ex_addrlen;
2496 	if (argp->ex_masklen) {
2497 		smask = (struct sockaddr *) ((caddr_t) saddr + argp->ex_addrlen);
2498 		error = copyin(argp->ex_mask, (caddr_t) smask, argp->ex_masklen);
2499 		if (error)
2500 			goto out;
2501 		if (smask->sa_len > argp->ex_masklen)
2502 			smask->sa_len = argp->ex_masklen;
2503 	}
2504 	i = saddr->sa_family;
2505 	if ((rnh = nep->ne_rtable[i]) == 0) {
2506 		/*
2507 		 * Seems silly to initialize every AF when most are not used,
2508 		 * do so on demand here
2509 		 */
2510 		for (dom = domains; dom; dom = dom->dom_next)
2511 			if (dom->dom_family == i && dom->dom_rtattach) {
2512 				dom->dom_rtattach((void **) &nep->ne_rtable[i],
2513 				    dom->dom_rtoffset);
2514 				break;
2515 			}
2516 		if ((rnh = nep->ne_rtable[i]) == 0) {
2517 			error = ENOBUFS;
2518 			goto out;
2519 		}
2520 	}
2521 	rn = (*rnh->rnh_addaddr) ((caddr_t) saddr, (caddr_t) smask, rnh,
2522 	    np->netc_rnodes);
2523 	if (rn == 0 || np != (struct netcred *) rn) {	/* already exists */
2524 		error = EPERM;
2525 		goto out;
2526 	}
2527 	np->netc_exflags = argp->ex_flags;
2528 	np->netc_anon = argp->ex_anon;
2529 	np->netc_anon.cr_ref = 1;
2530 	return (0);
2531 out:
2532 	free(np, M_NETADDR);
2533 	return (error);
2534 }
2535 
2536 /* ARGSUSED */
2537 static int
2538 vfs_free_netcred(rn, w)
2539 	struct radix_node *rn;
2540 	void *w;
2541 {
2542 	struct radix_node_head *rnh = (struct radix_node_head *) w;
2543 
2544 	(*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
2545 	free((caddr_t) rn, M_NETADDR);
2546 	return (0);
2547 }
2548 
2549 /*
2550  * Free the net address hash lists that are hanging off the mount points.
2551  */
2552 static void
2553 vfs_free_addrlist(nep)
2554 	struct netexport *nep;
2555 {
2556 	int i;
2557 	struct radix_node_head *rnh;
2558 
2559 	for (i = 0; i <= AF_MAX; i++)
2560 		if ((rnh = nep->ne_rtable[i])) {
2561 			(*rnh->rnh_walktree) (rnh, vfs_free_netcred,
2562 			    (caddr_t) rnh);
2563 			free((caddr_t) rnh, M_RTABLE);
2564 			nep->ne_rtable[i] = 0;
2565 		}
2566 }
2567 
2568 int
2569 vfs_export(mp, nep, argp)
2570 	struct mount *mp;
2571 	struct netexport *nep;
2572 	struct export_args *argp;
2573 {
2574 	int error;
2575 
2576 	if (argp->ex_flags & MNT_DELEXPORT) {
2577 		if (mp->mnt_flag & MNT_EXPUBLIC) {
2578 			vfs_setpublicfs(NULL, NULL, NULL);
2579 			mp->mnt_flag &= ~MNT_EXPUBLIC;
2580 		}
2581 		vfs_free_addrlist(nep);
2582 		mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
2583 	}
2584 	if (argp->ex_flags & MNT_EXPORTED) {
2585 		if (argp->ex_flags & MNT_EXPUBLIC) {
2586 			if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
2587 				return (error);
2588 			mp->mnt_flag |= MNT_EXPUBLIC;
2589 		}
2590 		if ((error = vfs_hang_addrlist(mp, nep, argp)))
2591 			return (error);
2592 		mp->mnt_flag |= MNT_EXPORTED;
2593 	}
2594 	return (0);
2595 }
2596 
2597 
2598 /*
2599  * Set the publicly exported filesystem (WebNFS). Currently, only
2600  * one public filesystem is possible in the spec (RFC 2054 and 2055)
2601  */
2602 int
2603 vfs_setpublicfs(mp, nep, argp)
2604 	struct mount *mp;
2605 	struct netexport *nep;
2606 	struct export_args *argp;
2607 {
2608 	int error;
2609 	struct vnode *rvp;
2610 	char *cp;
2611 
2612 	/*
2613 	 * mp == NULL -> invalidate the current info, the FS is
2614 	 * no longer exported. May be called from either vfs_export
2615 	 * or unmount, so check if it hasn't already been done.
2616 	 */
2617 	if (mp == NULL) {
2618 		if (nfs_pub.np_valid) {
2619 			nfs_pub.np_valid = 0;
2620 			if (nfs_pub.np_index != NULL) {
2621 				FREE(nfs_pub.np_index, M_TEMP);
2622 				nfs_pub.np_index = NULL;
2623 			}
2624 		}
2625 		return (0);
2626 	}
2627 
2628 	/*
2629 	 * Only one allowed at a time.
2630 	 */
2631 	if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
2632 		return (EBUSY);
2633 
2634 	/*
2635 	 * Get real filehandle for root of exported FS.
2636 	 */
2637 	bzero((caddr_t)&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
2638 	nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
2639 
2640 	if ((error = VFS_ROOT(mp, &rvp)))
2641 		return (error);
2642 
2643 	if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
2644 		return (error);
2645 
2646 	vput(rvp);
2647 
2648 	/*
2649 	 * If an indexfile was specified, pull it in.
2650 	 */
2651 	if (argp->ex_indexfile != NULL) {
2652 		MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
2653 		    M_WAITOK);
2654 		error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
2655 		    MAXNAMLEN, (size_t *)0);
2656 		if (!error) {
2657 			/*
2658 			 * Check for illegal filenames.
2659 			 */
2660 			for (cp = nfs_pub.np_index; *cp; cp++) {
2661 				if (*cp == '/') {
2662 					error = EINVAL;
2663 					break;
2664 				}
2665 			}
2666 		}
2667 		if (error) {
2668 			FREE(nfs_pub.np_index, M_TEMP);
2669 			return (error);
2670 		}
2671 	}
2672 
2673 	nfs_pub.np_mount = mp;
2674 	nfs_pub.np_valid = 1;
2675 	return (0);
2676 }
2677 
2678 struct netcred *
2679 vfs_export_lookup(mp, nep, nam)
2680 	struct mount *mp;
2681 	struct netexport *nep;
2682 	struct sockaddr *nam;
2683 {
2684 	struct netcred *np;
2685 	struct radix_node_head *rnh;
2686 	struct sockaddr *saddr;
2687 
2688 	np = NULL;
2689 	if (mp->mnt_flag & MNT_EXPORTED) {
2690 		/*
2691 		 * Lookup in the export list first.
2692 		 */
2693 		if (nam != NULL) {
2694 			saddr = nam;
2695 			rnh = nep->ne_rtable[saddr->sa_family];
2696 			if (rnh != NULL) {
2697 				np = (struct netcred *)
2698 					(*rnh->rnh_matchaddr)((caddr_t)saddr,
2699 							      rnh);
2700 				if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
2701 					np = NULL;
2702 			}
2703 		}
2704 		/*
2705 		 * If no address match, use the default if it exists.
2706 		 */
2707 		if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
2708 			np = &nep->ne_defexported;
2709 	}
2710 	return (np);
2711 }
2712 
2713 /*
2714  * perform msync on all vnodes under a mount point
2715  * the mount point must be locked.
2716  */
2717 void
2718 vfs_msync(struct mount *mp, int flags)
2719 {
2720 	struct thread *td = curthread;	/* XXX */
2721 	struct vnode *vp, *nvp;
2722 	struct vm_object *obj;
2723 	int tries;
2724 
2725 	tries = 5;
2726 	lwkt_gettoken(&mntvnode_token);
2727 loop:
2728 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
2729 		if (vp->v_mount != mp) {
2730 			if (--tries > 0)
2731 				goto loop;
2732 			break;
2733 		}
2734 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
2735 
2736 		if (vp->v_flag & VXLOCK)	/* XXX: what if MNT_WAIT? */
2737 			continue;
2738 
2739 		/*
2740 		 * There could be hundreds of thousands of vnodes, we cannot
2741 		 * afford to do anything heavy-weight until we have a fairly
2742 		 * good indication that there is something to do.
2743 		 */
2744 		if ((vp->v_flag & VOBJDIRTY) &&
2745 		    (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
2746 			lwkt_reltoken(&mntvnode_token);
2747 			if (!vget(vp,
2748 			    LK_EXCLUSIVE | LK_RETRY | LK_NOOBJ, td)) {
2749 				if (VOP_GETVOBJECT(vp, &obj) == 0) {
2750 					vm_object_page_clean(obj, 0, 0, flags == MNT_WAIT ? OBJPC_SYNC : OBJPC_NOSYNC);
2751 				}
2752 				vput(vp);
2753 			}
2754 			lwkt_gettoken(&mntvnode_token);
2755 			if (TAILQ_NEXT(vp, v_nmntvnodes) != nvp) {
2756 				if (--tries > 0)
2757 					goto loop;
2758 				break;
2759 			}
2760 		}
2761 	}
2762 	lwkt_reltoken(&mntvnode_token);
2763 }
2764 
2765 /*
2766  * Create the VM object needed for VMIO and mmap support.  This
2767  * is done for all VREG files in the system.  Some filesystems might
2768  * afford the additional metadata buffering capability of the
2769  * VMIO code by making the device node be VMIO mode also.
2770  *
2771  * vp must be locked when vfs_object_create is called.
2772  */
2773 int
2774 vfs_object_create(struct vnode *vp, struct thread *td)
2775 {
2776 	return (VOP_CREATEVOBJECT(vp, td));
2777 }
2778 
2779 void
2780 vfree(vp)
2781 	struct vnode *vp;
2782 {
2783 	int s;
2784 
2785 	s = splbio();
2786 	lwkt_gettoken(&vnode_free_list_token);
2787 	KASSERT((vp->v_flag & VFREE) == 0, ("vnode already free"));
2788 	if (vp->v_flag & VAGE) {
2789 		TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
2790 	} else {
2791 		TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
2792 	}
2793 	freevnodes++;
2794 	lwkt_reltoken(&vnode_free_list_token);
2795 	vp->v_flag &= ~VAGE;
2796 	vp->v_flag |= VFREE;
2797 	splx(s);
2798 }
2799 
2800 void
2801 vbusy(vp)
2802 	struct vnode *vp;
2803 {
2804 	int s;
2805 
2806 	s = splbio();
2807 	lwkt_gettoken(&vnode_free_list_token);
2808 	KASSERT((vp->v_flag & VFREE) != 0, ("vnode not free"));
2809 	TAILQ_REMOVE(&vnode_free_list, vp, v_freelist);
2810 	freevnodes--;
2811 	lwkt_reltoken(&vnode_free_list_token);
2812 	vp->v_flag &= ~(VFREE|VAGE);
2813 	splx(s);
2814 }
2815 
2816 /*
2817  * Record a process's interest in events which might happen to
2818  * a vnode.  Because poll uses the historic select-style interface
2819  * internally, this routine serves as both the ``check for any
2820  * pending events'' and the ``record my interest in future events''
2821  * functions.  (These are done together, while the lock is held,
2822  * to avoid race conditions.)
2823  */
2824 int
2825 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
2826 {
2827 	lwkt_gettoken(&vp->v_pollinfo.vpi_token);
2828 	if (vp->v_pollinfo.vpi_revents & events) {
2829 		/*
2830 		 * This leaves events we are not interested
2831 		 * in available for the other process which
2832 		 * which presumably had requested them
2833 		 * (otherwise they would never have been
2834 		 * recorded).
2835 		 */
2836 		events &= vp->v_pollinfo.vpi_revents;
2837 		vp->v_pollinfo.vpi_revents &= ~events;
2838 
2839 		lwkt_reltoken(&vp->v_pollinfo.vpi_token);
2840 		return events;
2841 	}
2842 	vp->v_pollinfo.vpi_events |= events;
2843 	selrecord(td, &vp->v_pollinfo.vpi_selinfo);
2844 	lwkt_reltoken(&vp->v_pollinfo.vpi_token);
2845 	return 0;
2846 }
2847 
2848 /*
2849  * Note the occurrence of an event.  If the VN_POLLEVENT macro is used,
2850  * it is possible for us to miss an event due to race conditions, but
2851  * that condition is expected to be rare, so for the moment it is the
2852  * preferred interface.
2853  */
2854 void
2855 vn_pollevent(vp, events)
2856 	struct vnode *vp;
2857 	short events;
2858 {
2859 	lwkt_gettoken(&vp->v_pollinfo.vpi_token);
2860 	if (vp->v_pollinfo.vpi_events & events) {
2861 		/*
2862 		 * We clear vpi_events so that we don't
2863 		 * call selwakeup() twice if two events are
2864 		 * posted before the polling process(es) is
2865 		 * awakened.  This also ensures that we take at
2866 		 * most one selwakeup() if the polling process
2867 		 * is no longer interested.  However, it does
2868 		 * mean that only one event can be noticed at
2869 		 * a time.  (Perhaps we should only clear those
2870 		 * event bits which we note?) XXX
2871 		 */
2872 		vp->v_pollinfo.vpi_events = 0;	/* &= ~events ??? */
2873 		vp->v_pollinfo.vpi_revents |= events;
2874 		selwakeup(&vp->v_pollinfo.vpi_selinfo);
2875 	}
2876 	lwkt_reltoken(&vp->v_pollinfo.vpi_token);
2877 }
2878 
2879 /*
2880  * Wake up anyone polling on vp because it is being revoked.
2881  * This depends on dead_poll() returning POLLHUP for correct
2882  * behavior.
2883  */
2884 void
2885 vn_pollgone(vp)
2886 	struct vnode *vp;
2887 {
2888 	lwkt_gettoken(&vp->v_pollinfo.vpi_token);
2889 	if (vp->v_pollinfo.vpi_events) {
2890 		vp->v_pollinfo.vpi_events = 0;
2891 		selwakeup(&vp->v_pollinfo.vpi_selinfo);
2892 	}
2893 	lwkt_reltoken(&vp->v_pollinfo.vpi_token);
2894 }
2895 
2896 
2897 
2898 /*
2899  * Routine to create and manage a filesystem syncer vnode.
2900  */
2901 #define sync_close ((int (*) (struct  vop_close_args *))nullop)
2902 static int	sync_fsync (struct  vop_fsync_args *);
2903 static int	sync_inactive (struct  vop_inactive_args *);
2904 static int	sync_reclaim  (struct  vop_reclaim_args *);
2905 #define sync_lock ((int (*) (struct  vop_lock_args *))vop_nolock)
2906 #define sync_unlock ((int (*) (struct  vop_unlock_args *))vop_nounlock)
2907 static int	sync_print (struct vop_print_args *);
2908 #define sync_islocked ((int(*) (struct vop_islocked_args *))vop_noislocked)
2909 
2910 static vop_t **sync_vnodeop_p;
2911 static struct vnodeopv_entry_desc sync_vnodeop_entries[] = {
2912 	{ &vop_default_desc,	(vop_t *) vop_eopnotsupp },
2913 	{ &vop_close_desc,	(vop_t *) sync_close },		/* close */
2914 	{ &vop_fsync_desc,	(vop_t *) sync_fsync },		/* fsync */
2915 	{ &vop_inactive_desc,	(vop_t *) sync_inactive },	/* inactive */
2916 	{ &vop_reclaim_desc,	(vop_t *) sync_reclaim },	/* reclaim */
2917 	{ &vop_lock_desc,	(vop_t *) sync_lock },		/* lock */
2918 	{ &vop_unlock_desc,	(vop_t *) sync_unlock },	/* unlock */
2919 	{ &vop_print_desc,	(vop_t *) sync_print },		/* print */
2920 	{ &vop_islocked_desc,	(vop_t *) sync_islocked },	/* islocked */
2921 	{ NULL, NULL }
2922 };
2923 static struct vnodeopv_desc sync_vnodeop_opv_desc =
2924 	{ &sync_vnodeop_p, sync_vnodeop_entries };
2925 
2926 VNODEOP_SET(sync_vnodeop_opv_desc);
2927 
2928 /*
2929  * Create a new filesystem syncer vnode for the specified mount point.
2930  */
2931 int
2932 vfs_allocate_syncvnode(mp)
2933 	struct mount *mp;
2934 {
2935 	struct vnode *vp;
2936 	static long start, incr, next;
2937 	int error;
2938 
2939 	/* Allocate a new vnode */
2940 	if ((error = getnewvnode(VT_VFS, mp, sync_vnodeop_p, &vp)) != 0) {
2941 		mp->mnt_syncer = NULL;
2942 		return (error);
2943 	}
2944 	vp->v_type = VNON;
2945 	/*
2946 	 * Place the vnode onto the syncer worklist. We attempt to
2947 	 * scatter them about on the list so that they will go off
2948 	 * at evenly distributed times even if all the filesystems
2949 	 * are mounted at once.
2950 	 */
2951 	next += incr;
2952 	if (next == 0 || next > syncer_maxdelay) {
2953 		start /= 2;
2954 		incr /= 2;
2955 		if (start == 0) {
2956 			start = syncer_maxdelay / 2;
2957 			incr = syncer_maxdelay;
2958 		}
2959 		next = start;
2960 	}
2961 	vn_syncer_add_to_worklist(vp, syncdelay > 0 ? next % syncdelay : 0);
2962 	mp->mnt_syncer = vp;
2963 	return (0);
2964 }
2965 
2966 /*
2967  * Do a lazy sync of the filesystem.
2968  */
2969 static int
2970 sync_fsync(ap)
2971 	struct vop_fsync_args /* {
2972 		struct vnode *a_vp;
2973 		struct ucred *a_cred;
2974 		int a_waitfor;
2975 		struct thread *a_td;
2976 	} */ *ap;
2977 {
2978 	struct vnode *syncvp = ap->a_vp;
2979 	struct mount *mp = syncvp->v_mount;
2980 	struct thread *td = ap->a_td;
2981 	int asyncflag;
2982 
2983 	/*
2984 	 * We only need to do something if this is a lazy evaluation.
2985 	 */
2986 	if (ap->a_waitfor != MNT_LAZY)
2987 		return (0);
2988 
2989 	/*
2990 	 * Move ourselves to the back of the sync list.
2991 	 */
2992 	vn_syncer_add_to_worklist(syncvp, syncdelay);
2993 
2994 	/*
2995 	 * Walk the list of vnodes pushing all that are dirty and
2996 	 * not already on the sync list.
2997 	 */
2998 	lwkt_gettoken(&mountlist_token);
2999 	if (vfs_busy(mp, LK_EXCLUSIVE | LK_NOWAIT, &mountlist_token, td) != 0) {
3000 		lwkt_reltoken(&mountlist_token);
3001 		return (0);
3002 	}
3003 	asyncflag = mp->mnt_flag & MNT_ASYNC;
3004 	mp->mnt_flag &= ~MNT_ASYNC;
3005 	vfs_msync(mp, MNT_NOWAIT);
3006 	VFS_SYNC(mp, MNT_LAZY, td);
3007 	if (asyncflag)
3008 		mp->mnt_flag |= MNT_ASYNC;
3009 	vfs_unbusy(mp, td);
3010 	return (0);
3011 }
3012 
3013 /*
3014  * The syncer vnode is no referenced.
3015  */
3016 static int
3017 sync_inactive(ap)
3018 	struct vop_inactive_args /* {
3019 		struct vnode *a_vp;
3020 		struct proc *a_p;
3021 	} */ *ap;
3022 {
3023 
3024 	vgone(ap->a_vp);
3025 	return (0);
3026 }
3027 
3028 /*
3029  * The syncer vnode is no longer needed and is being decommissioned.
3030  *
3031  * Modifications to the worklist must be protected at splbio().
3032  */
3033 static int
3034 sync_reclaim(ap)
3035 	struct vop_reclaim_args /* {
3036 		struct vnode *a_vp;
3037 	} */ *ap;
3038 {
3039 	struct vnode *vp = ap->a_vp;
3040 	int s;
3041 
3042 	s = splbio();
3043 	vp->v_mount->mnt_syncer = NULL;
3044 	if (vp->v_flag & VONWORKLST) {
3045 		LIST_REMOVE(vp, v_synclist);
3046 		vp->v_flag &= ~VONWORKLST;
3047 	}
3048 	splx(s);
3049 
3050 	return (0);
3051 }
3052 
3053 /*
3054  * Print out a syncer vnode.
3055  */
3056 static int
3057 sync_print(ap)
3058 	struct vop_print_args /* {
3059 		struct vnode *a_vp;
3060 	} */ *ap;
3061 {
3062 	struct vnode *vp = ap->a_vp;
3063 
3064 	printf("syncer vnode");
3065 	if (vp->v_vnlock != NULL)
3066 		lockmgr_printinfo(vp->v_vnlock);
3067 	printf("\n");
3068 	return (0);
3069 }
3070 
3071 /*
3072  * extract the dev_t from a VBLK or VCHR
3073  */
3074 dev_t
3075 vn_todev(vp)
3076 	struct vnode *vp;
3077 {
3078 	if (vp->v_type != VBLK && vp->v_type != VCHR)
3079 		return (NODEV);
3080 	return (vp->v_rdev);
3081 }
3082 
3083 /*
3084  * Check if vnode represents a disk device
3085  */
3086 int
3087 vn_isdisk(vp, errp)
3088 	struct vnode *vp;
3089 	int *errp;
3090 {
3091 	if (vp->v_type != VBLK && vp->v_type != VCHR) {
3092 		if (errp != NULL)
3093 			*errp = ENOTBLK;
3094 		return (0);
3095 	}
3096 	if (vp->v_rdev == NULL) {
3097 		if (errp != NULL)
3098 			*errp = ENXIO;
3099 		return (0);
3100 	}
3101 	if (!dev_dport(vp->v_rdev)) {
3102 		if (errp != NULL)
3103 			*errp = ENXIO;
3104 		return (0);
3105 	}
3106 	if (!(dev_dflags(vp->v_rdev) & D_DISK)) {
3107 		if (errp != NULL)
3108 			*errp = ENOTBLK;
3109 		return (0);
3110 	}
3111 	if (errp != NULL)
3112 		*errp = 0;
3113 	return (1);
3114 }
3115 
3116 void
3117 NDFREE(ndp, flags)
3118      struct nameidata *ndp;
3119      const uint flags;
3120 {
3121 	if (!(flags & NDF_NO_FREE_PNBUF) &&
3122 	    (ndp->ni_cnd.cn_flags & CNP_HASBUF)) {
3123 		zfree(namei_zone, ndp->ni_cnd.cn_pnbuf);
3124 		ndp->ni_cnd.cn_flags &= ~CNP_HASBUF;
3125 	}
3126 	if (!(flags & NDF_NO_DNCP_RELE) &&
3127 	    (ndp->ni_cnd.cn_flags & CNP_WANTDNCP) &&
3128 	    ndp->ni_dncp) {
3129 		cache_drop(ndp->ni_dncp);
3130 		ndp->ni_dncp = NULL;
3131 	}
3132 	if (!(flags & NDF_NO_NCP_RELE) &&
3133 	    (ndp->ni_cnd.cn_flags & CNP_WANTNCP) &&
3134 	    ndp->ni_ncp) {
3135 		cache_drop(ndp->ni_ncp);
3136 		ndp->ni_ncp = NULL;
3137 	}
3138 	if (!(flags & NDF_NO_DVP_UNLOCK) &&
3139 	    (ndp->ni_cnd.cn_flags & CNP_LOCKPARENT) &&
3140 	    ndp->ni_dvp != ndp->ni_vp) {
3141 		VOP_UNLOCK(ndp->ni_dvp, 0, ndp->ni_cnd.cn_td);
3142 	}
3143 	if (!(flags & NDF_NO_DVP_RELE) &&
3144 	    (ndp->ni_cnd.cn_flags & (CNP_LOCKPARENT|CNP_WANTPARENT))) {
3145 		vrele(ndp->ni_dvp);
3146 		ndp->ni_dvp = NULL;
3147 	}
3148 	if (!(flags & NDF_NO_VP_UNLOCK) &&
3149 	    (ndp->ni_cnd.cn_flags & CNP_LOCKLEAF) && ndp->ni_vp) {
3150 		VOP_UNLOCK(ndp->ni_vp, 0, ndp->ni_cnd.cn_td);
3151 	}
3152 	if (!(flags & NDF_NO_VP_RELE) &&
3153 	    ndp->ni_vp) {
3154 		vrele(ndp->ni_vp);
3155 		ndp->ni_vp = NULL;
3156 	}
3157 	if (!(flags & NDF_NO_STARTDIR_RELE) &&
3158 	    (ndp->ni_cnd.cn_flags & CNP_SAVESTART)) {
3159 		vrele(ndp->ni_startdir);
3160 		ndp->ni_startdir = NULL;
3161 	}
3162 }
3163 
3164