xref: /dragonfly/sys/kern/vfs_subr.c (revision 71126e33)
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 1.50 2004/12/17 00:18:07 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/reboot.h>
63 #include <sys/socket.h>
64 #include <sys/stat.h>
65 #include <sys/sysctl.h>
66 #include <sys/syslog.h>
67 #include <sys/vmmeter.h>
68 #include <sys/vnode.h>
69 
70 #include <machine/limits.h>
71 
72 #include <vm/vm.h>
73 #include <vm/vm_object.h>
74 #include <vm/vm_extern.h>
75 #include <vm/vm_kern.h>
76 #include <vm/pmap.h>
77 #include <vm/vm_map.h>
78 #include <vm/vm_page.h>
79 #include <vm/vm_pager.h>
80 #include <vm/vnode_pager.h>
81 #include <vm/vm_zone.h>
82 
83 #include <sys/buf2.h>
84 #include <sys/thread2.h>
85 
86 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
87 
88 int numvnodes;
89 SYSCTL_INT(_debug, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0, "");
90 int vfs_fastdev = 1;
91 SYSCTL_INT(_vfs, OID_AUTO, fastdev, CTLFLAG_RW, &vfs_fastdev, 0, "");
92 
93 enum vtype iftovt_tab[16] = {
94 	VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
95 	VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
96 };
97 int vttoif_tab[9] = {
98 	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
99 	S_IFSOCK, S_IFIFO, S_IFMT,
100 };
101 
102 static int reassignbufcalls;
103 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW,
104 		&reassignbufcalls, 0, "");
105 static int reassignbufloops;
106 SYSCTL_INT(_vfs, OID_AUTO, reassignbufloops, CTLFLAG_RW,
107 		&reassignbufloops, 0, "");
108 static int reassignbufsortgood;
109 SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortgood, CTLFLAG_RW,
110 		&reassignbufsortgood, 0, "");
111 static int reassignbufsortbad;
112 SYSCTL_INT(_vfs, OID_AUTO, reassignbufsortbad, CTLFLAG_RW,
113 		&reassignbufsortbad, 0, "");
114 static int reassignbufmethod = 1;
115 SYSCTL_INT(_vfs, OID_AUTO, reassignbufmethod, CTLFLAG_RW,
116 		&reassignbufmethod, 0, "");
117 
118 int	nfs_mount_type = -1;
119 static struct lwkt_token spechash_token;
120 struct nfs_public nfs_pub;	/* publicly exported FS */
121 
122 int desiredvnodes;
123 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
124 		&desiredvnodes, 0, "Maximum number of vnodes");
125 
126 static void	vfs_free_addrlist (struct netexport *nep);
127 static int	vfs_free_netcred (struct radix_node *rn, void *w);
128 static int	vfs_hang_addrlist (struct mount *mp, struct netexport *nep,
129 				       struct export_args *argp);
130 
131 extern int dev_ref_debug;
132 extern struct vnodeopv_entry_desc spec_vnodeop_entries[];
133 
134 /*
135  * Return 0 if the vnode is already on the free list or cannot be placed
136  * on the free list.  Return 1 if the vnode can be placed on the free list.
137  */
138 static __inline int
139 vshouldfree(struct vnode *vp, int usecount)
140 {
141 	if (vp->v_flag & VFREE)
142 		return (0);		/* already free */
143 	if (vp->v_holdcnt != 0 || vp->v_usecount != usecount)
144 		return (0);		/* other holderse */
145 	if (vp->v_object &&
146 	    (vp->v_object->ref_count || vp->v_object->resident_page_count)) {
147 		return (0);
148 	}
149 	return (1);
150 }
151 
152 /*
153  * Initialize the vnode management data structures.
154  *
155  * Called from vfsinit()
156  */
157 void
158 vfs_subr_init(void)
159 {
160 	/*
161 	 * Desired vnodes is a result of the physical page count
162 	 * and the size of kernel's heap.  It scales in proportion
163 	 * to the amount of available physical memory.  This can
164 	 * cause trouble on 64-bit and large memory platforms.
165 	 */
166 	/* desiredvnodes = maxproc + vmstats.v_page_count / 4; */
167 	desiredvnodes =
168 		min(maxproc + vmstats.v_page_count /4,
169 		    2 * (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) /
170 		    (5 * (sizeof(struct vm_object) + sizeof(struct vnode))));
171 
172 	lwkt_token_init(&spechash_token);
173 }
174 
175 /*
176  * Knob to control the precision of file timestamps:
177  *
178  *   0 = seconds only; nanoseconds zeroed.
179  *   1 = seconds and nanoseconds, accurate within 1/HZ.
180  *   2 = seconds and nanoseconds, truncated to microseconds.
181  * >=3 = seconds and nanoseconds, maximum precision.
182  */
183 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
184 
185 static int timestamp_precision = TSP_SEC;
186 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
187 		&timestamp_precision, 0, "");
188 
189 /*
190  * Get a current timestamp.
191  */
192 void
193 vfs_timestamp(struct timespec *tsp)
194 {
195 	struct timeval tv;
196 
197 	switch (timestamp_precision) {
198 	case TSP_SEC:
199 		tsp->tv_sec = time_second;
200 		tsp->tv_nsec = 0;
201 		break;
202 	case TSP_HZ:
203 		getnanotime(tsp);
204 		break;
205 	case TSP_USEC:
206 		microtime(&tv);
207 		TIMEVAL_TO_TIMESPEC(&tv, tsp);
208 		break;
209 	case TSP_NSEC:
210 	default:
211 		nanotime(tsp);
212 		break;
213 	}
214 }
215 
216 /*
217  * Set vnode attributes to VNOVAL
218  */
219 void
220 vattr_null(struct vattr *vap)
221 {
222 	vap->va_type = VNON;
223 	vap->va_size = VNOVAL;
224 	vap->va_bytes = VNOVAL;
225 	vap->va_mode = VNOVAL;
226 	vap->va_nlink = VNOVAL;
227 	vap->va_uid = VNOVAL;
228 	vap->va_gid = VNOVAL;
229 	vap->va_fsid = VNOVAL;
230 	vap->va_fileid = VNOVAL;
231 	vap->va_blocksize = VNOVAL;
232 	vap->va_rdev = VNOVAL;
233 	vap->va_atime.tv_sec = VNOVAL;
234 	vap->va_atime.tv_nsec = VNOVAL;
235 	vap->va_mtime.tv_sec = VNOVAL;
236 	vap->va_mtime.tv_nsec = VNOVAL;
237 	vap->va_ctime.tv_sec = VNOVAL;
238 	vap->va_ctime.tv_nsec = VNOVAL;
239 	vap->va_flags = VNOVAL;
240 	vap->va_gen = VNOVAL;
241 	vap->va_vaflags = 0;
242 }
243 
244 /*
245  * Update outstanding I/O count and do wakeup if requested.
246  */
247 void
248 vwakeup(struct buf *bp)
249 {
250 	struct vnode *vp;
251 
252 	bp->b_flags &= ~B_WRITEINPROG;
253 	if ((vp = bp->b_vp)) {
254 		vp->v_numoutput--;
255 		if (vp->v_numoutput < 0)
256 			panic("vwakeup: neg numoutput");
257 		if ((vp->v_numoutput == 0) && (vp->v_flag & VBWAIT)) {
258 			vp->v_flag &= ~VBWAIT;
259 			wakeup((caddr_t) &vp->v_numoutput);
260 		}
261 	}
262 }
263 
264 /*
265  * Flush out and invalidate all buffers associated with a vnode.
266  *
267  * vp must be locked.
268  */
269 int
270 vinvalbuf(struct vnode *vp, int flags, struct thread *td,
271 	int slpflag, int slptimeo)
272 {
273 	struct buf *bp;
274 	struct buf *nbp, *blist;
275 	int s, error;
276 	vm_object_t object;
277 
278 	if (flags & V_SAVE) {
279 		s = splbio();
280 		while (vp->v_numoutput) {
281 			vp->v_flag |= VBWAIT;
282 			error = tsleep((caddr_t)&vp->v_numoutput,
283 			    slpflag, "vinvlbuf", slptimeo);
284 			if (error) {
285 				splx(s);
286 				return (error);
287 			}
288 		}
289 		if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
290 			splx(s);
291 			if ((error = VOP_FSYNC(vp, MNT_WAIT, td)) != 0)
292 				return (error);
293 			s = splbio();
294 			if (vp->v_numoutput > 0 ||
295 			    !TAILQ_EMPTY(&vp->v_dirtyblkhd))
296 				panic("vinvalbuf: dirty bufs");
297 		}
298 		splx(s);
299   	}
300 	s = splbio();
301 	for (;;) {
302 		blist = TAILQ_FIRST(&vp->v_cleanblkhd);
303 		if (!blist)
304 			blist = TAILQ_FIRST(&vp->v_dirtyblkhd);
305 		if (!blist)
306 			break;
307 
308 		for (bp = blist; bp; bp = nbp) {
309 			nbp = TAILQ_NEXT(bp, b_vnbufs);
310 			if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
311 				error = BUF_TIMELOCK(bp,
312 				    LK_EXCLUSIVE | LK_SLEEPFAIL,
313 				    "vinvalbuf", slpflag, slptimeo);
314 				if (error == ENOLCK)
315 					break;
316 				splx(s);
317 				return (error);
318 			}
319 			/*
320 			 * XXX Since there are no node locks for NFS, I
321 			 * believe there is a slight chance that a delayed
322 			 * write will occur while sleeping just above, so
323 			 * check for it.  Note that vfs_bio_awrite expects
324 			 * buffers to reside on a queue, while VOP_BWRITE and
325 			 * brelse do not.
326 			 */
327 			if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
328 				(flags & V_SAVE)) {
329 
330 				if (bp->b_vp == vp) {
331 					if (bp->b_flags & B_CLUSTEROK) {
332 						BUF_UNLOCK(bp);
333 						vfs_bio_awrite(bp);
334 					} else {
335 						bremfree(bp);
336 						bp->b_flags |= B_ASYNC;
337 						VOP_BWRITE(bp->b_vp, bp);
338 					}
339 				} else {
340 					bremfree(bp);
341 					(void) VOP_BWRITE(bp->b_vp, bp);
342 				}
343 				break;
344 			}
345 			bremfree(bp);
346 			bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF);
347 			bp->b_flags &= ~B_ASYNC;
348 			brelse(bp);
349 		}
350 	}
351 
352 	/*
353 	 * Wait for I/O to complete.  XXX needs cleaning up.  The vnode can
354 	 * have write I/O in-progress but if there is a VM object then the
355 	 * VM object can also have read-I/O in-progress.
356 	 */
357 	do {
358 		while (vp->v_numoutput > 0) {
359 			vp->v_flag |= VBWAIT;
360 			tsleep(&vp->v_numoutput, 0, "vnvlbv", 0);
361 		}
362 		if (VOP_GETVOBJECT(vp, &object) == 0) {
363 			while (object->paging_in_progress)
364 				vm_object_pip_sleep(object, "vnvlbx");
365 		}
366 	} while (vp->v_numoutput > 0);
367 
368 	splx(s);
369 
370 	/*
371 	 * Destroy the copy in the VM cache, too.
372 	 */
373 	if (VOP_GETVOBJECT(vp, &object) == 0) {
374 		vm_object_page_remove(object, 0, 0,
375 			(flags & V_SAVE) ? TRUE : FALSE);
376 	}
377 
378 	if (!TAILQ_EMPTY(&vp->v_dirtyblkhd) || !TAILQ_EMPTY(&vp->v_cleanblkhd))
379 		panic("vinvalbuf: flush failed");
380 	return (0);
381 }
382 
383 /*
384  * Truncate a file's buffer and pages to a specified length.  This
385  * is in lieu of the old vinvalbuf mechanism, which performed unneeded
386  * sync activity.
387  *
388  * The vnode must be locked.
389  */
390 int
391 vtruncbuf(struct vnode *vp, struct thread *td, off_t length, int blksize)
392 {
393 	struct buf *bp;
394 	struct buf *nbp;
395 	int s, anyfreed;
396 	int trunclbn;
397 
398 	/*
399 	 * Round up to the *next* lbn.
400 	 */
401 	trunclbn = (length + blksize - 1) / blksize;
402 
403 	s = splbio();
404 restart:
405 	anyfreed = 1;
406 	for (;anyfreed;) {
407 		anyfreed = 0;
408 		for (bp = TAILQ_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
409 			nbp = TAILQ_NEXT(bp, b_vnbufs);
410 			if (bp->b_lblkno >= trunclbn) {
411 				if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
412 					BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL);
413 					goto restart;
414 				} else {
415 					bremfree(bp);
416 					bp->b_flags |= (B_INVAL | B_RELBUF);
417 					bp->b_flags &= ~B_ASYNC;
418 					brelse(bp);
419 					anyfreed = 1;
420 				}
421 				if (nbp &&
422 				    (((nbp->b_xflags & BX_VNCLEAN) == 0) ||
423 				    (nbp->b_vp != vp) ||
424 				    (nbp->b_flags & B_DELWRI))) {
425 					goto restart;
426 				}
427 			}
428 		}
429 
430 		for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
431 			nbp = TAILQ_NEXT(bp, b_vnbufs);
432 			if (bp->b_lblkno >= trunclbn) {
433 				if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
434 					BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL);
435 					goto restart;
436 				} else {
437 					bremfree(bp);
438 					bp->b_flags |= (B_INVAL | B_RELBUF);
439 					bp->b_flags &= ~B_ASYNC;
440 					brelse(bp);
441 					anyfreed = 1;
442 				}
443 				if (nbp &&
444 				    (((nbp->b_xflags & BX_VNDIRTY) == 0) ||
445 				    (nbp->b_vp != vp) ||
446 				    (nbp->b_flags & B_DELWRI) == 0)) {
447 					goto restart;
448 				}
449 			}
450 		}
451 	}
452 
453 	if (length > 0) {
454 restartsync:
455 		for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
456 			nbp = TAILQ_NEXT(bp, b_vnbufs);
457 			if ((bp->b_flags & B_DELWRI) && (bp->b_lblkno < 0)) {
458 				if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
459 					BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL);
460 					goto restart;
461 				} else {
462 					bremfree(bp);
463 					if (bp->b_vp == vp) {
464 						bp->b_flags |= B_ASYNC;
465 					} else {
466 						bp->b_flags &= ~B_ASYNC;
467 					}
468 					VOP_BWRITE(bp->b_vp, bp);
469 				}
470 				goto restartsync;
471 			}
472 
473 		}
474 	}
475 
476 	while (vp->v_numoutput > 0) {
477 		vp->v_flag |= VBWAIT;
478 		tsleep(&vp->v_numoutput, 0, "vbtrunc", 0);
479 	}
480 
481 	splx(s);
482 
483 	vnode_pager_setsize(vp, length);
484 
485 	return (0);
486 }
487 
488 /*
489  * Associate a buffer with a vnode.
490  */
491 void
492 bgetvp(struct vnode *vp, struct buf *bp)
493 {
494 	KASSERT(bp->b_vp == NULL, ("bgetvp: not free"));
495 
496 	vhold(vp);
497 	bp->b_vp = vp;
498 	bp->b_dev = vn_todev(vp);
499 	/*
500 	 * Insert onto list for new vnode.
501 	 */
502 	crit_enter();
503 	bp->b_xflags |= BX_VNCLEAN;
504 	bp->b_xflags &= ~BX_VNDIRTY;
505 	TAILQ_INSERT_TAIL(&vp->v_cleanblkhd, bp, b_vnbufs);
506 	crit_exit();
507 }
508 
509 /*
510  * Disassociate a buffer from a vnode.
511  */
512 void
513 brelvp(struct buf *bp)
514 {
515 	struct vnode *vp;
516 	struct buflists *listheadp;
517 
518 	KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
519 
520 	/*
521 	 * Delete from old vnode list, if on one.
522 	 */
523 	vp = bp->b_vp;
524 	crit_enter();
525 	if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) {
526 		if (bp->b_xflags & BX_VNDIRTY)
527 			listheadp = &vp->v_dirtyblkhd;
528 		else
529 			listheadp = &vp->v_cleanblkhd;
530 		TAILQ_REMOVE(listheadp, bp, b_vnbufs);
531 		bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
532 	}
533 	if ((vp->v_flag & VONWORKLST) && TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
534 		vp->v_flag &= ~VONWORKLST;
535 		LIST_REMOVE(vp, v_synclist);
536 	}
537 	crit_exit();
538 	bp->b_vp = NULL;
539 	vdrop(vp);
540 }
541 
542 /*
543  * Associate a p-buffer with a vnode.
544  *
545  * Also sets B_PAGING flag to indicate that vnode is not fully associated
546  * with the buffer.  i.e. the bp has not been linked into the vnode or
547  * ref-counted.
548  */
549 void
550 pbgetvp(struct vnode *vp, struct buf *bp)
551 {
552 	KASSERT(bp->b_vp == NULL, ("pbgetvp: not free"));
553 
554 	bp->b_vp = vp;
555 	bp->b_flags |= B_PAGING;
556 	bp->b_dev = vn_todev(vp);
557 }
558 
559 /*
560  * Disassociate a p-buffer from a vnode.
561  */
562 void
563 pbrelvp(struct buf *bp)
564 {
565 	KASSERT(bp->b_vp != NULL, ("pbrelvp: NULL"));
566 
567 	/* XXX REMOVE ME */
568 	if (TAILQ_NEXT(bp, b_vnbufs) != NULL) {
569 		panic(
570 		    "relpbuf(): b_vp was probably reassignbuf()d %p %x",
571 		    bp,
572 		    (int)bp->b_flags
573 		);
574 	}
575 	bp->b_vp = (struct vnode *) 0;
576 	bp->b_flags &= ~B_PAGING;
577 }
578 
579 void
580 pbreassignbuf(struct buf *bp, struct vnode *newvp)
581 {
582 	if ((bp->b_flags & B_PAGING) == 0) {
583 		panic(
584 		    "pbreassignbuf() on non phys bp %p",
585 		    bp
586 		);
587 	}
588 	bp->b_vp = newvp;
589 }
590 
591 /*
592  * Reassign a buffer from one vnode to another.
593  * Used to assign file specific control information
594  * (indirect blocks) to the vnode to which they belong.
595  */
596 void
597 reassignbuf(struct buf *bp, struct vnode *newvp)
598 {
599 	struct buflists *listheadp;
600 	int delay;
601 
602 	if (newvp == NULL) {
603 		printf("reassignbuf: NULL");
604 		return;
605 	}
606 	++reassignbufcalls;
607 
608 	/*
609 	 * B_PAGING flagged buffers cannot be reassigned because their vp
610 	 * is not fully linked in.
611 	 */
612 	if (bp->b_flags & B_PAGING)
613 		panic("cannot reassign paging buffer");
614 
615 	crit_enter();
616 	/*
617 	 * Delete from old vnode list, if on one.
618 	 */
619 	if (bp->b_xflags & (BX_VNDIRTY | BX_VNCLEAN)) {
620 		if (bp->b_xflags & BX_VNDIRTY)
621 			listheadp = &bp->b_vp->v_dirtyblkhd;
622 		else
623 			listheadp = &bp->b_vp->v_cleanblkhd;
624 		TAILQ_REMOVE(listheadp, bp, b_vnbufs);
625 		bp->b_xflags &= ~(BX_VNDIRTY | BX_VNCLEAN);
626 		if (bp->b_vp != newvp) {
627 			vdrop(bp->b_vp);
628 			bp->b_vp = NULL;	/* for clarification */
629 		}
630 	}
631 	/*
632 	 * If dirty, put on list of dirty buffers; otherwise insert onto list
633 	 * of clean buffers.
634 	 */
635 	if (bp->b_flags & B_DELWRI) {
636 		struct buf *tbp;
637 
638 		listheadp = &newvp->v_dirtyblkhd;
639 		if ((newvp->v_flag & VONWORKLST) == 0) {
640 			switch (newvp->v_type) {
641 			case VDIR:
642 				delay = dirdelay;
643 				break;
644 			case VCHR:
645 			case VBLK:
646 				if (newvp->v_rdev &&
647 				    newvp->v_rdev->si_mountpoint != NULL) {
648 					delay = metadelay;
649 					break;
650 				}
651 				/* fall through */
652 			default:
653 				delay = filedelay;
654 			}
655 			vn_syncer_add_to_worklist(newvp, delay);
656 		}
657 		bp->b_xflags |= BX_VNDIRTY;
658 		tbp = TAILQ_FIRST(listheadp);
659 		if (tbp == NULL ||
660 		    bp->b_lblkno == 0 ||
661 		    (bp->b_lblkno > 0 && tbp->b_lblkno < 0) ||
662 		    (bp->b_lblkno > 0 && bp->b_lblkno < tbp->b_lblkno)) {
663 			TAILQ_INSERT_HEAD(listheadp, bp, b_vnbufs);
664 			++reassignbufsortgood;
665 		} else if (bp->b_lblkno < 0) {
666 			TAILQ_INSERT_TAIL(listheadp, bp, b_vnbufs);
667 			++reassignbufsortgood;
668 		} else if (reassignbufmethod == 1) {
669 			/*
670 			 * New sorting algorithm, only handle sequential case,
671 			 * otherwise append to end (but before metadata)
672 			 */
673 			if ((tbp = gbincore(newvp, bp->b_lblkno - 1)) != NULL &&
674 			    (tbp->b_xflags & BX_VNDIRTY)) {
675 				/*
676 				 * Found the best place to insert the buffer
677 				 */
678 				TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
679 				++reassignbufsortgood;
680 			} else {
681 				/*
682 				 * Missed, append to end, but before meta-data.
683 				 * We know that the head buffer in the list is
684 				 * not meta-data due to prior conditionals.
685 				 *
686 				 * Indirect effects:  NFS second stage write
687 				 * tends to wind up here, giving maximum
688 				 * distance between the unstable write and the
689 				 * commit rpc.
690 				 */
691 				tbp = TAILQ_LAST(listheadp, buflists);
692 				while (tbp && tbp->b_lblkno < 0)
693 					tbp = TAILQ_PREV(tbp, buflists, b_vnbufs);
694 				TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
695 				++reassignbufsortbad;
696 			}
697 		} else {
698 			/*
699 			 * Old sorting algorithm, scan queue and insert
700 			 */
701 			struct buf *ttbp;
702 			while ((ttbp = TAILQ_NEXT(tbp, b_vnbufs)) &&
703 			    (ttbp->b_lblkno < bp->b_lblkno)) {
704 				++reassignbufloops;
705 				tbp = ttbp;
706 			}
707 			TAILQ_INSERT_AFTER(listheadp, tbp, bp, b_vnbufs);
708 		}
709 	} else {
710 		bp->b_xflags |= BX_VNCLEAN;
711 		TAILQ_INSERT_TAIL(&newvp->v_cleanblkhd, bp, b_vnbufs);
712 		if ((newvp->v_flag & VONWORKLST) &&
713 		    TAILQ_EMPTY(&newvp->v_dirtyblkhd)) {
714 			newvp->v_flag &= ~VONWORKLST;
715 			LIST_REMOVE(newvp, v_synclist);
716 		}
717 	}
718 	if (bp->b_vp != newvp) {
719 		bp->b_vp = newvp;
720 		vhold(bp->b_vp);
721 	}
722 	crit_exit();
723 }
724 
725 /*
726  * Create a vnode for a block device.
727  * Used for mounting the root file system.
728  */
729 int
730 bdevvp(dev_t dev, struct vnode **vpp)
731 {
732 	struct vnode *vp;
733 	struct vnode *nvp;
734 	int error;
735 
736 	if (dev == NODEV) {
737 		*vpp = NULLVP;
738 		return (ENXIO);
739 	}
740 	error = getspecialvnode(VT_NON, NULL, &spec_vnode_vops, &nvp, 0, 0);
741 	if (error) {
742 		*vpp = NULLVP;
743 		return (error);
744 	}
745 	vp = nvp;
746 	vp->v_type = VCHR;
747 	vp->v_udev = dev->si_udev;
748 	vx_unlock(vp);
749 	*vpp = vp;
750 	return (0);
751 }
752 
753 int
754 v_associate_rdev(struct vnode *vp, dev_t dev)
755 {
756 	lwkt_tokref ilock;
757 
758 	if (dev == NULL || dev == NODEV)
759 		return(ENXIO);
760 	if (dev_is_good(dev) == 0)
761 		return(ENXIO);
762 	KKASSERT(vp->v_rdev == NULL);
763 	if (dev_ref_debug)
764 		printf("Z1");
765 	vp->v_rdev = reference_dev(dev);
766 	lwkt_gettoken(&ilock, &spechash_token);
767 	SLIST_INSERT_HEAD(&dev->si_hlist, vp, v_specnext);
768 	lwkt_reltoken(&ilock);
769 	return(0);
770 }
771 
772 void
773 v_release_rdev(struct vnode *vp)
774 {
775 	lwkt_tokref ilock;
776 	dev_t dev;
777 
778 	if ((dev = vp->v_rdev) != NULL) {
779 		lwkt_gettoken(&ilock, &spechash_token);
780 		SLIST_REMOVE(&dev->si_hlist, vp, vnode, v_specnext);
781 		if (dev_ref_debug && vp->v_opencount != 0) {
782 			printf("releasing rdev with non-0 "
783 				"v_opencount(%d) (revoked?)\n",
784 				vp->v_opencount);
785 		}
786 		vp->v_rdev = NULL;
787 		vp->v_opencount = 0;
788 		release_dev(dev);
789 		lwkt_reltoken(&ilock);
790 	}
791 }
792 
793 /*
794  * Add a vnode to the alias list hung off the dev_t.  We only associate
795  * the device number with the vnode.  The actual device is not associated
796  * until the vnode is opened (usually in spec_open()), and will be
797  * disassociated on last close.
798  */
799 void
800 addaliasu(struct vnode *nvp, udev_t nvp_udev)
801 {
802 	if (nvp->v_type != VBLK && nvp->v_type != VCHR)
803 		panic("addaliasu on non-special vnode");
804 	nvp->v_udev = nvp_udev;
805 }
806 
807 /*
808  * Disassociate a vnode from its underlying filesystem.
809  *
810  * The vnode must be VX locked and refd
811  *
812  * If there are v_usecount references to the vnode other then ours we have
813  * to VOP_CLOSE the vnode before we can deactivate and reclaim it.
814  */
815 void
816 vclean(struct vnode *vp, int flags, struct thread *td)
817 {
818 	int active;
819 
820 	/*
821 	 * If the vnode has already been reclaimed we have nothing to do.
822 	 */
823 	if (vp->v_flag & VRECLAIMED)
824 		return;
825 	vp->v_flag |= VRECLAIMED;
826 
827 	/*
828 	 * Scrap the vfs cache
829 	 */
830 	cache_inval_vp(vp, 0);
831 
832 	/*
833 	 * Check to see if the vnode is in use. If so we have to reference it
834 	 * before we clean it out so that its count cannot fall to zero and
835 	 * generate a race against ourselves to recycle it.
836 	 */
837 	active = (vp->v_usecount > 1);
838 
839 	/*
840 	 * Clean out any buffers associated with the vnode and destroy its
841 	 * object, if it has one.
842 	 */
843 	vinvalbuf(vp, V_SAVE, td, 0, 0);
844 	VOP_DESTROYVOBJECT(vp);
845 
846 	/*
847 	 * If purging an active vnode, it must be closed and
848 	 * deactivated before being reclaimed.   XXX
849 	 *
850 	 * Note that neither of these routines unlocks the vnode.
851 	 */
852 	if (active) {
853 		if (flags & DOCLOSE)
854 			VOP_CLOSE(vp, FNONBLOCK, td);
855 	}
856 
857 	/*
858 	 * If the vnode has not be deactivated, deactivated it.
859 	 */
860 	if ((vp->v_flag & VINACTIVE) == 0) {
861 		vp->v_flag |= VINACTIVE;
862 		VOP_INACTIVE(vp, td);
863 	}
864 
865 	/*
866 	 * Reclaim the vnode.
867 	 */
868 	if (VOP_RECLAIM(vp, td))
869 		panic("vclean: cannot reclaim");
870 
871 	/*
872 	 * Done with purge, notify sleepers of the grim news.
873 	 */
874 	vp->v_ops = &dead_vnode_vops;
875 	vn_pollgone(vp);
876 	vp->v_tag = VT_NON;
877 }
878 
879 /*
880  * Eliminate all activity associated with the requested vnode
881  * and with all vnodes aliased to the requested vnode.
882  *
883  * The vnode must be referenced and vx_lock()'d
884  *
885  * revoke { struct vnode *a_vp, int a_flags }
886  */
887 int
888 vop_stdrevoke(struct vop_revoke_args *ap)
889 {
890 	struct vnode *vp, *vq;
891 	lwkt_tokref ilock;
892 	dev_t dev;
893 
894 	KASSERT((ap->a_flags & REVOKEALL) != 0, ("vop_revoke"));
895 
896 	vp = ap->a_vp;
897 
898 	/*
899 	 * If the vnode is already dead don't try to revoke it
900 	 */
901 	if (vp->v_flag & VRECLAIMED)
902 		return (0);
903 
904 	/*
905 	 * If the vnode has a device association, scrap all vnodes associated
906 	 * with the device.  Don't let the device disappear on us while we
907 	 * are scrapping the vnodes.
908 	 *
909 	 * The passed vp will probably show up in the list, do not VX lock
910 	 * it twice!
911 	 */
912 	if (vp->v_type != VCHR && vp->v_type != VBLK)
913 		return(0);
914 	if ((dev = vp->v_rdev) == NULL) {
915 		if ((dev = udev2dev(vp->v_udev, vp->v_type == VBLK)) == NODEV)
916 			return(0);
917 	}
918 	reference_dev(dev);
919 	lwkt_gettoken(&ilock, &spechash_token);
920 	while ((vq = SLIST_FIRST(&dev->si_hlist)) != NULL) {
921 		if (vp == vq || vx_get(vq) == 0) {
922 			if (vq == SLIST_FIRST(&dev->si_hlist))
923 				vgone(vq);
924 			if (vp != vq)
925 				vx_put(vq);
926 		}
927 	}
928 	lwkt_reltoken(&ilock);
929 	release_dev(dev);
930 	return (0);
931 }
932 
933 /*
934  * Recycle an unused vnode to the front of the free list.
935  *
936  * Returns 1 if we were successfully able to recycle the vnode,
937  * 0 otherwise.
938  */
939 int
940 vrecycle(struct vnode *vp, struct thread *td)
941 {
942 	if (vp->v_usecount == 1) {
943 		vgone(vp);
944 		return (1);
945 	}
946 	return (0);
947 }
948 
949 /*
950  * Eliminate all activity associated with a vnode in preparation for reuse.
951  *
952  * The vnode must be VX locked and refd and will remain VX locked and refd
953  * on return.  This routine may be called with the vnode in any state, as
954  * long as it is VX locked.  The vnode will be cleaned out and marked
955  * VRECLAIMED but will not actually be reused until all existing refs and
956  * holds go away.
957  *
958  * NOTE: This routine may be called on a vnode which has not yet been
959  * already been deactivated (VOP_INACTIVE), or on a vnode which has
960  * already been reclaimed.
961  *
962  * This routine is not responsible for placing us back on the freelist.
963  * Instead, it happens automatically when the caller releases the VX lock
964  * (assuming there aren't any other references).
965  */
966 void
967 vgone(struct vnode *vp)
968 {
969 	/*
970 	 * assert that the VX lock is held.  This is an absolute requirement
971 	 * now for vgone() to be called.
972 	 */
973 	KKASSERT(vp->v_lock.lk_exclusivecount == 1);
974 
975 	/*
976 	 * Clean out the filesystem specific data and set the VRECLAIMED
977 	 * bit.  Also deactivate the vnode if necessary.
978 	 */
979 	vclean(vp, DOCLOSE, curthread);
980 
981 	/*
982 	 * Delete from old mount point vnode list, if on one.
983 	 */
984 	if (vp->v_mount != NULL)
985 		insmntque(vp, NULL);
986 
987 	/*
988 	 * If special device, remove it from special device alias list
989 	 * if it is on one.  This should normally only occur if a vnode is
990 	 * being revoked as the device should otherwise have been released
991 	 * naturally.
992 	 */
993 	if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_rdev != NULL) {
994 		v_release_rdev(vp);
995 	}
996 
997 	/*
998 	 * Set us to VBAD
999 	 */
1000 	vp->v_type = VBAD;
1001 }
1002 
1003 /*
1004  * Lookup a vnode by device number.
1005  */
1006 int
1007 vfinddev(dev_t dev, enum vtype type, struct vnode **vpp)
1008 {
1009 	lwkt_tokref ilock;
1010 	struct vnode *vp;
1011 
1012 	lwkt_gettoken(&ilock, &spechash_token);
1013 	SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) {
1014 		if (type == vp->v_type) {
1015 			*vpp = vp;
1016 			lwkt_reltoken(&ilock);
1017 			return (1);
1018 		}
1019 	}
1020 	lwkt_reltoken(&ilock);
1021 	return (0);
1022 }
1023 
1024 /*
1025  * Calculate the total number of references to a special device.  This
1026  * routine may only be called for VBLK and VCHR vnodes since v_rdev is
1027  * an overloaded field.  Since udev2dev can now return NODEV, we have
1028  * to check for a NULL v_rdev.
1029  */
1030 int
1031 count_dev(dev_t dev)
1032 {
1033 	lwkt_tokref ilock;
1034 	struct vnode *vp;
1035 	int count = 0;
1036 
1037 	if (SLIST_FIRST(&dev->si_hlist)) {
1038 		lwkt_gettoken(&ilock, &spechash_token);
1039 		SLIST_FOREACH(vp, &dev->si_hlist, v_specnext) {
1040 			count += vp->v_usecount;
1041 		}
1042 		lwkt_reltoken(&ilock);
1043 	}
1044 	return(count);
1045 }
1046 
1047 int
1048 count_udev(udev_t udev)
1049 {
1050 	dev_t dev;
1051 
1052 	if ((dev = udev2dev(udev, 0)) == NODEV)
1053 		return(0);
1054 	return(count_dev(dev));
1055 }
1056 
1057 int
1058 vcount(struct vnode *vp)
1059 {
1060 	if (vp->v_rdev == NULL)
1061 		return(0);
1062 	return(count_dev(vp->v_rdev));
1063 }
1064 
1065 /*
1066  * Print out a description of a vnode.
1067  */
1068 static char *typename[] =
1069 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"};
1070 
1071 void
1072 vprint(char *label, struct vnode *vp)
1073 {
1074 	char buf[96];
1075 
1076 	if (label != NULL)
1077 		printf("%s: %p: ", label, (void *)vp);
1078 	else
1079 		printf("%p: ", (void *)vp);
1080 	printf("type %s, usecount %d, writecount %d, refcount %d,",
1081 	    typename[vp->v_type], vp->v_usecount, vp->v_writecount,
1082 	    vp->v_holdcnt);
1083 	buf[0] = '\0';
1084 	if (vp->v_flag & VROOT)
1085 		strcat(buf, "|VROOT");
1086 	if (vp->v_flag & VTEXT)
1087 		strcat(buf, "|VTEXT");
1088 	if (vp->v_flag & VSYSTEM)
1089 		strcat(buf, "|VSYSTEM");
1090 	if (vp->v_flag & VBWAIT)
1091 		strcat(buf, "|VBWAIT");
1092 	if (vp->v_flag & VFREE)
1093 		strcat(buf, "|VFREE");
1094 	if (vp->v_flag & VOBJBUF)
1095 		strcat(buf, "|VOBJBUF");
1096 	if (buf[0] != '\0')
1097 		printf(" flags (%s)", &buf[1]);
1098 	if (vp->v_data == NULL) {
1099 		printf("\n");
1100 	} else {
1101 		printf("\n\t");
1102 		VOP_PRINT(vp);
1103 	}
1104 }
1105 
1106 #ifdef DDB
1107 #include <ddb/ddb.h>
1108 /*
1109  * List all of the locked vnodes in the system.
1110  * Called when debugging the kernel.
1111  */
1112 DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
1113 {
1114 	struct thread *td = curthread;	/* XXX */
1115 	lwkt_tokref ilock;
1116 	struct mount *mp, *nmp;
1117 	struct vnode *vp;
1118 
1119 	printf("Locked vnodes\n");
1120 	lwkt_gettoken(&ilock, &mountlist_token);
1121 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
1122 		if (vfs_busy(mp, LK_NOWAIT, &ilock, td)) {
1123 			nmp = TAILQ_NEXT(mp, mnt_list);
1124 			continue;
1125 		}
1126 		TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
1127 			if (VOP_ISLOCKED(vp, NULL))
1128 				vprint((char *)0, vp);
1129 		}
1130 		lwkt_gettokref(&ilock);
1131 		nmp = TAILQ_NEXT(mp, mnt_list);
1132 		vfs_unbusy(mp, td);
1133 	}
1134 	lwkt_reltoken(&ilock);
1135 }
1136 #endif
1137 
1138 /*
1139  * Top level filesystem related information gathering.
1140  */
1141 static int	sysctl_ovfs_conf (SYSCTL_HANDLER_ARGS);
1142 
1143 static int
1144 vfs_sysctl(SYSCTL_HANDLER_ARGS)
1145 {
1146 	int *name = (int *)arg1 - 1;	/* XXX */
1147 	u_int namelen = arg2 + 1;	/* XXX */
1148 	struct vfsconf *vfsp;
1149 
1150 #if 1 || defined(COMPAT_PRELITE2)
1151 	/* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
1152 	if (namelen == 1)
1153 		return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
1154 #endif
1155 
1156 #ifdef notyet
1157 	/* all sysctl names at this level are at least name and field */
1158 	if (namelen < 2)
1159 		return (ENOTDIR);		/* overloaded */
1160 	if (name[0] != VFS_GENERIC) {
1161 		for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
1162 			if (vfsp->vfc_typenum == name[0])
1163 				break;
1164 		if (vfsp == NULL)
1165 			return (EOPNOTSUPP);
1166 		return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1,
1167 		    oldp, oldlenp, newp, newlen, p));
1168 	}
1169 #endif
1170 	switch (name[1]) {
1171 	case VFS_MAXTYPENUM:
1172 		if (namelen != 2)
1173 			return (ENOTDIR);
1174 		return (SYSCTL_OUT(req, &maxvfsconf, sizeof(int)));
1175 	case VFS_CONF:
1176 		if (namelen != 3)
1177 			return (ENOTDIR);	/* overloaded */
1178 		for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next)
1179 			if (vfsp->vfc_typenum == name[2])
1180 				break;
1181 		if (vfsp == NULL)
1182 			return (EOPNOTSUPP);
1183 		return (SYSCTL_OUT(req, vfsp, sizeof *vfsp));
1184 	}
1185 	return (EOPNOTSUPP);
1186 }
1187 
1188 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl,
1189 	"Generic filesystem");
1190 
1191 #if 1 || defined(COMPAT_PRELITE2)
1192 
1193 static int
1194 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
1195 {
1196 	int error;
1197 	struct vfsconf *vfsp;
1198 	struct ovfsconf ovfs;
1199 
1200 	for (vfsp = vfsconf; vfsp; vfsp = vfsp->vfc_next) {
1201 		ovfs.vfc_vfsops = vfsp->vfc_vfsops;	/* XXX used as flag */
1202 		strcpy(ovfs.vfc_name, vfsp->vfc_name);
1203 		ovfs.vfc_index = vfsp->vfc_typenum;
1204 		ovfs.vfc_refcount = vfsp->vfc_refcount;
1205 		ovfs.vfc_flags = vfsp->vfc_flags;
1206 		error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
1207 		if (error)
1208 			return error;
1209 	}
1210 	return 0;
1211 }
1212 
1213 #endif /* 1 || COMPAT_PRELITE2 */
1214 
1215 #if 0
1216 #define KINFO_VNODESLOP	10
1217 /*
1218  * Dump vnode list (via sysctl).
1219  * Copyout address of vnode followed by vnode.
1220  */
1221 /* ARGSUSED */
1222 static int
1223 sysctl_vnode(SYSCTL_HANDLER_ARGS)
1224 {
1225 	struct proc *p = curproc;	/* XXX */
1226 	struct mount *mp, *nmp;
1227 	struct vnode *nvp, *vp;
1228 	lwkt_tokref ilock;
1229 	lwkt_tokref jlock;
1230 	int error;
1231 
1232 #define VPTRSZ	sizeof (struct vnode *)
1233 #define VNODESZ	sizeof (struct vnode)
1234 
1235 	req->lock = 0;
1236 	if (!req->oldptr) /* Make an estimate */
1237 		return (SYSCTL_OUT(req, 0,
1238 			(numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ)));
1239 
1240 	lwkt_gettoken(&ilock, &mountlist_token);
1241 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
1242 		if (vfs_busy(mp, LK_NOWAIT, &ilock, p)) {
1243 			nmp = TAILQ_NEXT(mp, mnt_list);
1244 			continue;
1245 		}
1246 		lwkt_gettoken(&jlock, &mntvnode_token);
1247 again:
1248 		for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist);
1249 		     vp != NULL;
1250 		     vp = nvp) {
1251 			/*
1252 			 * Check that the vp is still associated with
1253 			 * this filesystem.  RACE: could have been
1254 			 * recycled onto the same filesystem.
1255 			 */
1256 			if (vp->v_mount != mp)
1257 				goto again;
1258 			nvp = TAILQ_NEXT(vp, v_nmntvnodes);
1259 			if ((error = SYSCTL_OUT(req, &vp, VPTRSZ)) ||
1260 			    (error = SYSCTL_OUT(req, vp, VNODESZ))) {
1261 				lwkt_reltoken(&jlock);
1262 				return (error);
1263 			}
1264 		}
1265 		lwkt_reltoken(&jlock);
1266 		lwkt_gettokref(&ilock);
1267 		nmp = TAILQ_NEXT(mp, mnt_list);	/* ZZZ */
1268 		vfs_unbusy(mp, p);
1269 	}
1270 	lwkt_reltoken(&ilock);
1271 
1272 	return (0);
1273 }
1274 #endif
1275 
1276 /*
1277  * XXX
1278  * Exporting the vnode list on large systems causes them to crash.
1279  * Exporting the vnode list on medium systems causes sysctl to coredump.
1280  */
1281 #if 0
1282 SYSCTL_PROC(_kern, KERN_VNODE, vnode, CTLTYPE_OPAQUE|CTLFLAG_RD,
1283 	0, 0, sysctl_vnode, "S,vnode", "");
1284 #endif
1285 
1286 /*
1287  * Check to see if a filesystem is mounted on a block device.
1288  */
1289 int
1290 vfs_mountedon(struct vnode *vp)
1291 {
1292 	dev_t dev;
1293 
1294 	if ((dev = vp->v_rdev) == NULL)
1295 		dev = udev2dev(vp->v_udev, (vp->v_type == VBLK));
1296 	if (dev != NODEV && dev->si_mountpoint)
1297 		return (EBUSY);
1298 	return (0);
1299 }
1300 
1301 /*
1302  * Unmount all filesystems. The list is traversed in reverse order
1303  * of mounting to avoid dependencies.
1304  */
1305 void
1306 vfs_unmountall(void)
1307 {
1308 	struct mount *mp;
1309 	struct thread *td = curthread;
1310 	int error;
1311 
1312 	if (td->td_proc == NULL)
1313 		td = initproc->p_thread;	/* XXX XXX use proc0 instead? */
1314 
1315 	/*
1316 	 * Since this only runs when rebooting, it is not interlocked.
1317 	 */
1318 	while(!TAILQ_EMPTY(&mountlist)) {
1319 		mp = TAILQ_LAST(&mountlist, mntlist);
1320 		error = dounmount(mp, MNT_FORCE, td);
1321 		if (error) {
1322 			TAILQ_REMOVE(&mountlist, mp, mnt_list);
1323 			printf("unmount of %s failed (",
1324 			    mp->mnt_stat.f_mntonname);
1325 			if (error == EBUSY)
1326 				printf("BUSY)\n");
1327 			else
1328 				printf("%d)\n", error);
1329 		} else {
1330 			/* The unmount has removed mp from the mountlist */
1331 		}
1332 	}
1333 }
1334 
1335 /*
1336  * Build hash lists of net addresses and hang them off the mount point.
1337  * Called by ufs_mount() to set up the lists of export addresses.
1338  */
1339 static int
1340 vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
1341 		struct export_args *argp)
1342 {
1343 	struct netcred *np;
1344 	struct radix_node_head *rnh;
1345 	int i;
1346 	struct radix_node *rn;
1347 	struct sockaddr *saddr, *smask = 0;
1348 	struct domain *dom;
1349 	int error;
1350 
1351 	if (argp->ex_addrlen == 0) {
1352 		if (mp->mnt_flag & MNT_DEFEXPORTED)
1353 			return (EPERM);
1354 		np = &nep->ne_defexported;
1355 		np->netc_exflags = argp->ex_flags;
1356 		np->netc_anon = argp->ex_anon;
1357 		np->netc_anon.cr_ref = 1;
1358 		mp->mnt_flag |= MNT_DEFEXPORTED;
1359 		return (0);
1360 	}
1361 
1362 	if (argp->ex_addrlen < 0 || argp->ex_addrlen > MLEN)
1363 		return (EINVAL);
1364 	if (argp->ex_masklen < 0 || argp->ex_masklen > MLEN)
1365 		return (EINVAL);
1366 
1367 	i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
1368 	np = (struct netcred *) malloc(i, M_NETADDR, M_WAITOK);
1369 	bzero((caddr_t) np, i);
1370 	saddr = (struct sockaddr *) (np + 1);
1371 	if ((error = copyin(argp->ex_addr, (caddr_t) saddr, argp->ex_addrlen)))
1372 		goto out;
1373 	if (saddr->sa_len > argp->ex_addrlen)
1374 		saddr->sa_len = argp->ex_addrlen;
1375 	if (argp->ex_masklen) {
1376 		smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen);
1377 		error = copyin(argp->ex_mask, (caddr_t)smask, argp->ex_masklen);
1378 		if (error)
1379 			goto out;
1380 		if (smask->sa_len > argp->ex_masklen)
1381 			smask->sa_len = argp->ex_masklen;
1382 	}
1383 	i = saddr->sa_family;
1384 	if ((rnh = nep->ne_rtable[i]) == 0) {
1385 		/*
1386 		 * Seems silly to initialize every AF when most are not used,
1387 		 * do so on demand here
1388 		 */
1389 		for (dom = domains; dom; dom = dom->dom_next)
1390 			if (dom->dom_family == i && dom->dom_rtattach) {
1391 				dom->dom_rtattach((void **) &nep->ne_rtable[i],
1392 				    dom->dom_rtoffset);
1393 				break;
1394 			}
1395 		if ((rnh = nep->ne_rtable[i]) == 0) {
1396 			error = ENOBUFS;
1397 			goto out;
1398 		}
1399 	}
1400 	rn = (*rnh->rnh_addaddr) ((char *) saddr, (char *) smask, rnh,
1401 	    np->netc_rnodes);
1402 	if (rn == 0 || np != (struct netcred *) rn) {	/* already exists */
1403 		error = EPERM;
1404 		goto out;
1405 	}
1406 	np->netc_exflags = argp->ex_flags;
1407 	np->netc_anon = argp->ex_anon;
1408 	np->netc_anon.cr_ref = 1;
1409 	return (0);
1410 out:
1411 	free(np, M_NETADDR);
1412 	return (error);
1413 }
1414 
1415 /* ARGSUSED */
1416 static int
1417 vfs_free_netcred(struct radix_node *rn, void *w)
1418 {
1419 	struct radix_node_head *rnh = (struct radix_node_head *) w;
1420 
1421 	(*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
1422 	free((caddr_t) rn, M_NETADDR);
1423 	return (0);
1424 }
1425 
1426 /*
1427  * Free the net address hash lists that are hanging off the mount points.
1428  */
1429 static void
1430 vfs_free_addrlist(struct netexport *nep)
1431 {
1432 	int i;
1433 	struct radix_node_head *rnh;
1434 
1435 	for (i = 0; i <= AF_MAX; i++)
1436 		if ((rnh = nep->ne_rtable[i])) {
1437 			(*rnh->rnh_walktree) (rnh, vfs_free_netcred,
1438 			    (caddr_t) rnh);
1439 			free((caddr_t) rnh, M_RTABLE);
1440 			nep->ne_rtable[i] = 0;
1441 		}
1442 }
1443 
1444 int
1445 vfs_export(struct mount *mp, struct netexport *nep, struct export_args *argp)
1446 {
1447 	int error;
1448 
1449 	if (argp->ex_flags & MNT_DELEXPORT) {
1450 		if (mp->mnt_flag & MNT_EXPUBLIC) {
1451 			vfs_setpublicfs(NULL, NULL, NULL);
1452 			mp->mnt_flag &= ~MNT_EXPUBLIC;
1453 		}
1454 		vfs_free_addrlist(nep);
1455 		mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
1456 	}
1457 	if (argp->ex_flags & MNT_EXPORTED) {
1458 		if (argp->ex_flags & MNT_EXPUBLIC) {
1459 			if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
1460 				return (error);
1461 			mp->mnt_flag |= MNT_EXPUBLIC;
1462 		}
1463 		if ((error = vfs_hang_addrlist(mp, nep, argp)))
1464 			return (error);
1465 		mp->mnt_flag |= MNT_EXPORTED;
1466 	}
1467 	return (0);
1468 }
1469 
1470 
1471 /*
1472  * Set the publicly exported filesystem (WebNFS). Currently, only
1473  * one public filesystem is possible in the spec (RFC 2054 and 2055)
1474  */
1475 int
1476 vfs_setpublicfs(struct mount *mp, struct netexport *nep,
1477 		struct export_args *argp)
1478 {
1479 	int error;
1480 	struct vnode *rvp;
1481 	char *cp;
1482 
1483 	/*
1484 	 * mp == NULL -> invalidate the current info, the FS is
1485 	 * no longer exported. May be called from either vfs_export
1486 	 * or unmount, so check if it hasn't already been done.
1487 	 */
1488 	if (mp == NULL) {
1489 		if (nfs_pub.np_valid) {
1490 			nfs_pub.np_valid = 0;
1491 			if (nfs_pub.np_index != NULL) {
1492 				FREE(nfs_pub.np_index, M_TEMP);
1493 				nfs_pub.np_index = NULL;
1494 			}
1495 		}
1496 		return (0);
1497 	}
1498 
1499 	/*
1500 	 * Only one allowed at a time.
1501 	 */
1502 	if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
1503 		return (EBUSY);
1504 
1505 	/*
1506 	 * Get real filehandle for root of exported FS.
1507 	 */
1508 	bzero((caddr_t)&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
1509 	nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
1510 
1511 	if ((error = VFS_ROOT(mp, &rvp)))
1512 		return (error);
1513 
1514 	if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
1515 		return (error);
1516 
1517 	vput(rvp);
1518 
1519 	/*
1520 	 * If an indexfile was specified, pull it in.
1521 	 */
1522 	if (argp->ex_indexfile != NULL) {
1523 		MALLOC(nfs_pub.np_index, char *, MAXNAMLEN + 1, M_TEMP,
1524 		    M_WAITOK);
1525 		error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
1526 		    MAXNAMLEN, (size_t *)0);
1527 		if (!error) {
1528 			/*
1529 			 * Check for illegal filenames.
1530 			 */
1531 			for (cp = nfs_pub.np_index; *cp; cp++) {
1532 				if (*cp == '/') {
1533 					error = EINVAL;
1534 					break;
1535 				}
1536 			}
1537 		}
1538 		if (error) {
1539 			FREE(nfs_pub.np_index, M_TEMP);
1540 			return (error);
1541 		}
1542 	}
1543 
1544 	nfs_pub.np_mount = mp;
1545 	nfs_pub.np_valid = 1;
1546 	return (0);
1547 }
1548 
1549 struct netcred *
1550 vfs_export_lookup(struct mount *mp, struct netexport *nep,
1551 		struct sockaddr *nam)
1552 {
1553 	struct netcred *np;
1554 	struct radix_node_head *rnh;
1555 	struct sockaddr *saddr;
1556 
1557 	np = NULL;
1558 	if (mp->mnt_flag & MNT_EXPORTED) {
1559 		/*
1560 		 * Lookup in the export list first.
1561 		 */
1562 		if (nam != NULL) {
1563 			saddr = nam;
1564 			rnh = nep->ne_rtable[saddr->sa_family];
1565 			if (rnh != NULL) {
1566 				np = (struct netcred *)
1567 					(*rnh->rnh_matchaddr)((char *)saddr,
1568 							      rnh);
1569 				if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
1570 					np = NULL;
1571 			}
1572 		}
1573 		/*
1574 		 * If no address match, use the default if it exists.
1575 		 */
1576 		if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
1577 			np = &nep->ne_defexported;
1578 	}
1579 	return (np);
1580 }
1581 
1582 /*
1583  * perform msync on all vnodes under a mount point.  The mount point must
1584  * be locked.  This code is also responsible for lazy-freeing unreferenced
1585  * vnodes whos VM objects no longer contain pages.
1586  *
1587  * NOTE: MNT_WAIT still skips vnodes in the VXLOCK state.
1588  */
1589 static int vfs_msync_scan1(struct mount *mp, struct vnode *vp, void *data);
1590 static int vfs_msync_scan2(struct mount *mp, struct vnode *vp, void *data);
1591 
1592 void
1593 vfs_msync(struct mount *mp, int flags)
1594 {
1595 	vmntvnodescan(mp, VMSC_REFVP, vfs_msync_scan1, vfs_msync_scan2,
1596 			(void *)flags);
1597 }
1598 
1599 /*
1600  * scan1 is a fast pre-check.  There could be hundreds of thousands of
1601  * vnodes, we cannot afford to do anything heavy weight until we have a
1602  * fairly good indication that there is work to do.
1603  */
1604 static
1605 int
1606 vfs_msync_scan1(struct mount *mp, struct vnode *vp, void *data)
1607 {
1608 	int flags = (int)data;
1609 
1610 	if ((vp->v_flag & VRECLAIMED) == 0) {
1611 		if (vshouldfree(vp, 0))
1612 			return(0);	/* call scan2 */
1613 		if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
1614 		    (vp->v_flag & VOBJDIRTY) &&
1615 		    (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
1616 			return(0);	/* call scan2 */
1617 		}
1618 	}
1619 
1620 	/*
1621 	 * do not call scan2, continue the loop
1622 	 */
1623 	return(-1);
1624 }
1625 
1626 static
1627 int
1628 vfs_msync_scan2(struct mount *mp, struct vnode *vp, void *data)
1629 {
1630 	vm_object_t obj;
1631 	int flags = (int)data;
1632 
1633 	if (vp->v_flag & VRECLAIMED)
1634 		return(0);
1635 
1636 	if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
1637 	    (vp->v_flag & VOBJDIRTY) &&
1638 	    (flags == MNT_WAIT || VOP_ISLOCKED(vp, NULL) == 0)) {
1639 		if (VOP_GETVOBJECT(vp, &obj) == 0) {
1640 			vm_object_page_clean(obj, 0, 0,
1641 			 flags == MNT_WAIT ? OBJPC_SYNC : OBJPC_NOSYNC);
1642 		}
1643 	}
1644 	return(0);
1645 }
1646 
1647 /*
1648  * Create the VM object needed for VMIO and mmap support.  This
1649  * is done for all VREG files in the system.  Some filesystems might
1650  * afford the additional metadata buffering capability of the
1651  * VMIO code by making the device node be VMIO mode also.
1652  *
1653  * vp must be locked when vfs_object_create is called.
1654  */
1655 int
1656 vfs_object_create(struct vnode *vp, struct thread *td)
1657 {
1658 	return (VOP_CREATEVOBJECT(vp, td));
1659 }
1660 
1661 /*
1662  * Record a process's interest in events which might happen to
1663  * a vnode.  Because poll uses the historic select-style interface
1664  * internally, this routine serves as both the ``check for any
1665  * pending events'' and the ``record my interest in future events''
1666  * functions.  (These are done together, while the lock is held,
1667  * to avoid race conditions.)
1668  */
1669 int
1670 vn_pollrecord(struct vnode *vp, struct thread *td, int events)
1671 {
1672 	lwkt_tokref ilock;
1673 
1674 	lwkt_gettoken(&ilock, &vp->v_pollinfo.vpi_token);
1675 	if (vp->v_pollinfo.vpi_revents & events) {
1676 		/*
1677 		 * This leaves events we are not interested
1678 		 * in available for the other process which
1679 		 * which presumably had requested them
1680 		 * (otherwise they would never have been
1681 		 * recorded).
1682 		 */
1683 		events &= vp->v_pollinfo.vpi_revents;
1684 		vp->v_pollinfo.vpi_revents &= ~events;
1685 
1686 		lwkt_reltoken(&ilock);
1687 		return events;
1688 	}
1689 	vp->v_pollinfo.vpi_events |= events;
1690 	selrecord(td, &vp->v_pollinfo.vpi_selinfo);
1691 	lwkt_reltoken(&ilock);
1692 	return 0;
1693 }
1694 
1695 /*
1696  * Note the occurrence of an event.  If the VN_POLLEVENT macro is used,
1697  * it is possible for us to miss an event due to race conditions, but
1698  * that condition is expected to be rare, so for the moment it is the
1699  * preferred interface.
1700  */
1701 void
1702 vn_pollevent(struct vnode *vp, int events)
1703 {
1704 	lwkt_tokref ilock;
1705 
1706 	lwkt_gettoken(&ilock, &vp->v_pollinfo.vpi_token);
1707 	if (vp->v_pollinfo.vpi_events & events) {
1708 		/*
1709 		 * We clear vpi_events so that we don't
1710 		 * call selwakeup() twice if two events are
1711 		 * posted before the polling process(es) is
1712 		 * awakened.  This also ensures that we take at
1713 		 * most one selwakeup() if the polling process
1714 		 * is no longer interested.  However, it does
1715 		 * mean that only one event can be noticed at
1716 		 * a time.  (Perhaps we should only clear those
1717 		 * event bits which we note?) XXX
1718 		 */
1719 		vp->v_pollinfo.vpi_events = 0;	/* &= ~events ??? */
1720 		vp->v_pollinfo.vpi_revents |= events;
1721 		selwakeup(&vp->v_pollinfo.vpi_selinfo);
1722 	}
1723 	lwkt_reltoken(&ilock);
1724 }
1725 
1726 /*
1727  * Wake up anyone polling on vp because it is being revoked.
1728  * This depends on dead_poll() returning POLLHUP for correct
1729  * behavior.
1730  */
1731 void
1732 vn_pollgone(struct vnode *vp)
1733 {
1734 	lwkt_tokref ilock;
1735 
1736 	lwkt_gettoken(&ilock, &vp->v_pollinfo.vpi_token);
1737 	if (vp->v_pollinfo.vpi_events) {
1738 		vp->v_pollinfo.vpi_events = 0;
1739 		selwakeup(&vp->v_pollinfo.vpi_selinfo);
1740 	}
1741 	lwkt_reltoken(&ilock);
1742 }
1743 
1744 /*
1745  * extract the dev_t from a VBLK or VCHR.  The vnode must have been opened
1746  * (or v_rdev might be NULL).
1747  */
1748 dev_t
1749 vn_todev(struct vnode *vp)
1750 {
1751 	if (vp->v_type != VBLK && vp->v_type != VCHR)
1752 		return (NODEV);
1753 	KKASSERT(vp->v_rdev != NULL);
1754 	return (vp->v_rdev);
1755 }
1756 
1757 /*
1758  * Check if vnode represents a disk device.  The vnode does not need to be
1759  * opened.
1760  */
1761 int
1762 vn_isdisk(struct vnode *vp, int *errp)
1763 {
1764 	dev_t dev;
1765 
1766 	if (vp->v_type != VBLK && vp->v_type != VCHR) {
1767 		if (errp != NULL)
1768 			*errp = ENOTBLK;
1769 		return (0);
1770 	}
1771 
1772 	if ((dev = vp->v_rdev) == NULL)
1773 		dev = udev2dev(vp->v_udev, (vp->v_type == VBLK));
1774 	if (dev == NULL || dev == NODEV) {
1775 		if (errp != NULL)
1776 			*errp = ENXIO;
1777 		return (0);
1778 	}
1779 	if (dev_is_good(dev) == 0) {
1780 		if (errp != NULL)
1781 			*errp = ENXIO;
1782 		return (0);
1783 	}
1784 	if ((dev_dflags(dev) & D_DISK) == 0) {
1785 		if (errp != NULL)
1786 			*errp = ENOTBLK;
1787 		return (0);
1788 	}
1789 	if (errp != NULL)
1790 		*errp = 0;
1791 	return (1);
1792 }
1793 
1794 #ifdef DEBUG_VFS_LOCKS
1795 
1796 void
1797 assert_vop_locked(struct vnode *vp, const char *str)
1798 {
1799 	if (vp && IS_LOCKING_VFS(vp) && !VOP_ISLOCKED(vp, NULL)) {
1800 		panic("%s: %p is not locked shared but should be", str, vp);
1801 	}
1802 }
1803 
1804 void
1805 assert_vop_unlocked(struct vnode *vp, const char *str)
1806 {
1807 	if (vp && IS_LOCKING_VFS(vp)) {
1808 		if (VOP_ISLOCKED(vp, curthread) == LK_EXCLUSIVE) {
1809 			panic("%s: %p is locked but should not be", str, vp);
1810 		}
1811 	}
1812 }
1813 
1814 #endif
1815