xref: /dragonfly/sys/kern/vfs_subr.c (revision 07a2f99c)
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  */
41 
42 /*
43  * External virtual filesystem routines
44  */
45 #include "opt_ddb.h"
46 
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/buf.h>
50 #include <sys/conf.h>
51 #include <sys/dirent.h>
52 #include <sys/domain.h>
53 #include <sys/eventhandler.h>
54 #include <sys/fcntl.h>
55 #include <sys/file.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/priv.h>
62 #include <sys/proc.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/unistd.h>
69 #include <sys/vmmeter.h>
70 #include <sys/vnode.h>
71 
72 #include <machine/limits.h>
73 
74 #include <vm/vm.h>
75 #include <vm/vm_object.h>
76 #include <vm/vm_extern.h>
77 #include <vm/vm_kern.h>
78 #include <vm/pmap.h>
79 #include <vm/vm_map.h>
80 #include <vm/vm_page.h>
81 #include <vm/vm_pager.h>
82 #include <vm/vnode_pager.h>
83 #include <vm/vm_zone.h>
84 
85 #include <sys/buf2.h>
86 #include <sys/thread2.h>
87 #include <sys/sysref2.h>
88 #include <sys/mplock2.h>
89 
90 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
91 
92 int numvnodes;
93 SYSCTL_INT(_debug, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
94     "Number of vnodes allocated");
95 int verbose_reclaims;
96 SYSCTL_INT(_debug, OID_AUTO, verbose_reclaims, CTLFLAG_RD, &verbose_reclaims, 0,
97     "Output filename of reclaimed vnode(s)");
98 
99 enum vtype iftovt_tab[16] = {
100 	VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
101 	VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
102 };
103 int vttoif_tab[9] = {
104 	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
105 	S_IFSOCK, S_IFIFO, S_IFMT,
106 };
107 
108 static int reassignbufcalls;
109 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls,
110     0, "Number of times buffers have been reassigned to the proper list");
111 
112 static int check_buf_overlap = 2;	/* invasive check */
113 SYSCTL_INT(_vfs, OID_AUTO, check_buf_overlap, CTLFLAG_RW, &check_buf_overlap,
114     0, "Enable overlapping buffer checks");
115 
116 int	nfs_mount_type = -1;
117 static struct lwkt_token spechash_token;
118 struct nfs_public nfs_pub;	/* publicly exported FS */
119 
120 int desiredvnodes;
121 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
122 		&desiredvnodes, 0, "Maximum number of vnodes");
123 
124 static void	vfs_free_addrlist (struct netexport *nep);
125 static int	vfs_free_netcred (struct radix_node *rn, void *w);
126 static int	vfs_hang_addrlist (struct mount *mp, struct netexport *nep,
127 				       const struct export_args *argp);
128 
129 /*
130  * Red black tree functions
131  */
132 static int rb_buf_compare(struct buf *b1, struct buf *b2);
133 RB_GENERATE2(buf_rb_tree, buf, b_rbnode, rb_buf_compare, off_t, b_loffset);
134 RB_GENERATE2(buf_rb_hash, buf, b_rbhash, rb_buf_compare, off_t, b_loffset);
135 
136 static int
137 rb_buf_compare(struct buf *b1, struct buf *b2)
138 {
139 	if (b1->b_loffset < b2->b_loffset)
140 		return(-1);
141 	if (b1->b_loffset > b2->b_loffset)
142 		return(1);
143 	return(0);
144 }
145 
146 /*
147  * Returns non-zero if the vnode is a candidate for lazy msyncing.
148  *
149  * NOTE: v_object is not stable (this scan can race), however the
150  *	 mntvnodescan code holds vmobj_token so any VM object we
151  *	 do find will remain stable storage.
152  */
153 static __inline int
154 vshouldmsync(struct vnode *vp)
155 {
156 	vm_object_t object;
157 
158 	if (vp->v_auxrefs != 0 || vp->v_sysref.refcnt > 0)
159 		return (0);		/* other holders */
160 	object = vp->v_object;
161 	cpu_ccfence();
162 	if (object && (object->ref_count || object->resident_page_count))
163 		return(0);
164 	return (1);
165 }
166 
167 /*
168  * Initialize the vnode management data structures.
169  *
170  * Called from vfsinit()
171  */
172 void
173 vfs_subr_init(void)
174 {
175 	int factor1;
176 	int factor2;
177 
178 	/*
179 	 * Desiredvnodes is kern.maxvnodes.  We want to scale it
180 	 * according to available system memory but we may also have
181 	 * to limit it based on available KVM, which is capped on 32 bit
182 	 * systems, to ~80K vnodes or so.
183 	 *
184 	 * WARNING!  For machines with 64-256M of ram we have to be sure
185 	 *	     that the default limit scales down well due to HAMMER
186 	 *	     taking up significantly more memory per-vnode vs UFS.
187 	 *	     We want around ~5800 on a 128M machine.
188 	 */
189 	factor1 = 20 * (sizeof(struct vm_object) + sizeof(struct vnode));
190 	factor2 = 25 * (sizeof(struct vm_object) + sizeof(struct vnode));
191 	desiredvnodes =
192 		imin((int64_t)vmstats.v_page_count * PAGE_SIZE / factor1,
193 		     KvaSize / factor2);
194 	desiredvnodes = imax(desiredvnodes, maxproc * 8);
195 
196 	lwkt_token_init(&spechash_token, "spechash");
197 }
198 
199 /*
200  * Knob to control the precision of file timestamps:
201  *
202  *   0 = seconds only; nanoseconds zeroed.
203  *   1 = seconds and nanoseconds, accurate within 1/HZ.
204  *   2 = seconds and nanoseconds, truncated to microseconds.
205  * >=3 = seconds and nanoseconds, maximum precision.
206  */
207 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
208 
209 static int timestamp_precision = TSP_SEC;
210 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
211 		&timestamp_precision, 0, "Precision of file timestamps");
212 
213 /*
214  * Get a current timestamp.
215  *
216  * MPSAFE
217  */
218 void
219 vfs_timestamp(struct timespec *tsp)
220 {
221 	struct timeval tv;
222 
223 	switch (timestamp_precision) {
224 	case TSP_SEC:
225 		tsp->tv_sec = time_second;
226 		tsp->tv_nsec = 0;
227 		break;
228 	case TSP_HZ:
229 		getnanotime(tsp);
230 		break;
231 	case TSP_USEC:
232 		microtime(&tv);
233 		TIMEVAL_TO_TIMESPEC(&tv, tsp);
234 		break;
235 	case TSP_NSEC:
236 	default:
237 		nanotime(tsp);
238 		break;
239 	}
240 }
241 
242 /*
243  * Set vnode attributes to VNOVAL
244  */
245 void
246 vattr_null(struct vattr *vap)
247 {
248 	vap->va_type = VNON;
249 	vap->va_size = VNOVAL;
250 	vap->va_bytes = VNOVAL;
251 	vap->va_mode = VNOVAL;
252 	vap->va_nlink = VNOVAL;
253 	vap->va_uid = VNOVAL;
254 	vap->va_gid = VNOVAL;
255 	vap->va_fsid = VNOVAL;
256 	vap->va_fileid = VNOVAL;
257 	vap->va_blocksize = VNOVAL;
258 	vap->va_rmajor = VNOVAL;
259 	vap->va_rminor = VNOVAL;
260 	vap->va_atime.tv_sec = VNOVAL;
261 	vap->va_atime.tv_nsec = VNOVAL;
262 	vap->va_mtime.tv_sec = VNOVAL;
263 	vap->va_mtime.tv_nsec = VNOVAL;
264 	vap->va_ctime.tv_sec = VNOVAL;
265 	vap->va_ctime.tv_nsec = VNOVAL;
266 	vap->va_flags = VNOVAL;
267 	vap->va_gen = VNOVAL;
268 	vap->va_vaflags = 0;
269 	/* va_*_uuid fields are only valid if related flags are set */
270 }
271 
272 /*
273  * Flush out and invalidate all buffers associated with a vnode.
274  *
275  * vp must be locked.
276  */
277 static int vinvalbuf_bp(struct buf *bp, void *data);
278 
279 struct vinvalbuf_bp_info {
280 	struct vnode *vp;
281 	int slptimeo;
282 	int lkflags;
283 	int flags;
284 	int clean;
285 };
286 
287 int
288 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
289 {
290 	struct vinvalbuf_bp_info info;
291 	vm_object_t object;
292 	int error;
293 
294 	lwkt_gettoken(&vp->v_token);
295 
296 	/*
297 	 * If we are being asked to save, call fsync to ensure that the inode
298 	 * is updated.
299 	 */
300 	if (flags & V_SAVE) {
301 		error = bio_track_wait(&vp->v_track_write, slpflag, slptimeo);
302 		if (error)
303 			goto done;
304 		if (!RB_EMPTY(&vp->v_rbdirty_tree)) {
305 			if ((error = VOP_FSYNC(vp, MNT_WAIT, 0)) != 0)
306 				goto done;
307 #if 0
308 			/*
309 			 * Dirty bufs may be left or generated via races
310 			 * in circumstances where vinvalbuf() is called on
311 			 * a vnode not undergoing reclamation.   Only
312 			 * panic if we are trying to reclaim the vnode.
313 			 */
314 			if ((vp->v_flag & VRECLAIMED) &&
315 			    (bio_track_active(&vp->v_track_write) ||
316 			    !RB_EMPTY(&vp->v_rbdirty_tree))) {
317 				panic("vinvalbuf: dirty bufs");
318 			}
319 #endif
320 		}
321   	}
322 	info.slptimeo = slptimeo;
323 	info.lkflags = LK_EXCLUSIVE | LK_SLEEPFAIL;
324 	if (slpflag & PCATCH)
325 		info.lkflags |= LK_PCATCH;
326 	info.flags = flags;
327 	info.vp = vp;
328 
329 	/*
330 	 * Flush the buffer cache until nothing is left, wait for all I/O
331 	 * to complete.  At least one pass is required.  We might block
332 	 * in the pip code so we have to re-check.  Order is important.
333 	 */
334 	do {
335 		/*
336 		 * Flush buffer cache
337 		 */
338 		if (!RB_EMPTY(&vp->v_rbclean_tree)) {
339 			info.clean = 1;
340 			error = RB_SCAN(buf_rb_tree, &vp->v_rbclean_tree,
341 					NULL, vinvalbuf_bp, &info);
342 		}
343 		if (!RB_EMPTY(&vp->v_rbdirty_tree)) {
344 			info.clean = 0;
345 			error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
346 					NULL, vinvalbuf_bp, &info);
347 		}
348 
349 		/*
350 		 * Wait for I/O completion.
351 		 */
352 		bio_track_wait(&vp->v_track_write, 0, 0);
353 		if ((object = vp->v_object) != NULL)
354 			refcount_wait(&object->paging_in_progress, "vnvlbx");
355 	} while (bio_track_active(&vp->v_track_write) ||
356 		 !RB_EMPTY(&vp->v_rbclean_tree) ||
357 		 !RB_EMPTY(&vp->v_rbdirty_tree));
358 
359 	/*
360 	 * Destroy the copy in the VM cache, too.
361 	 */
362 	if ((object = vp->v_object) != NULL) {
363 		vm_object_page_remove(object, 0, 0,
364 			(flags & V_SAVE) ? TRUE : FALSE);
365 	}
366 
367 	if (!RB_EMPTY(&vp->v_rbdirty_tree) || !RB_EMPTY(&vp->v_rbclean_tree))
368 		panic("vinvalbuf: flush failed");
369 	if (!RB_EMPTY(&vp->v_rbhash_tree))
370 		panic("vinvalbuf: flush failed, buffers still present");
371 	error = 0;
372 done:
373 	lwkt_reltoken(&vp->v_token);
374 	return (error);
375 }
376 
377 static int
378 vinvalbuf_bp(struct buf *bp, void *data)
379 {
380 	struct vinvalbuf_bp_info *info = data;
381 	int error;
382 
383 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
384 		atomic_add_int(&bp->b_refs, 1);
385 		error = BUF_TIMELOCK(bp, info->lkflags,
386 				     "vinvalbuf", info->slptimeo);
387 		atomic_subtract_int(&bp->b_refs, 1);
388 		if (error == 0) {
389 			BUF_UNLOCK(bp);
390 			error = ENOLCK;
391 		}
392 		if (error == ENOLCK)
393 			return(0);
394 		return (-error);
395 	}
396 	KKASSERT(bp->b_vp == info->vp);
397 
398 	/*
399 	 * Must check clean/dirty status after successfully locking as
400 	 * it may race.
401 	 */
402 	if ((info->clean && (bp->b_flags & B_DELWRI)) ||
403 	    (info->clean == 0 && (bp->b_flags & B_DELWRI) == 0)) {
404 		BUF_UNLOCK(bp);
405 		return(0);
406 	}
407 
408 	/*
409 	 * NOTE:  NO B_LOCKED CHECK.  Also no buf_checkwrite()
410 	 * check.  This code will write out the buffer, period.
411 	 */
412 	bremfree(bp);
413 	if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
414 	    (info->flags & V_SAVE)) {
415 		cluster_awrite(bp);
416 	} else if (info->flags & V_SAVE) {
417 		/*
418 		 * Cannot set B_NOCACHE on a clean buffer as this will
419 		 * destroy the VM backing store which might actually
420 		 * be dirty (and unsynchronized).
421 		 */
422 		bp->b_flags |= (B_INVAL | B_RELBUF);
423 		brelse(bp);
424 	} else {
425 		bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF);
426 		brelse(bp);
427 	}
428 	return(0);
429 }
430 
431 /*
432  * Truncate a file's buffer and pages to a specified length.  This
433  * is in lieu of the old vinvalbuf mechanism, which performed unneeded
434  * sync activity.
435  *
436  * The vnode must be locked.
437  */
438 static int vtruncbuf_bp_trunc_cmp(struct buf *bp, void *data);
439 static int vtruncbuf_bp_trunc(struct buf *bp, void *data);
440 static int vtruncbuf_bp_metasync_cmp(struct buf *bp, void *data);
441 static int vtruncbuf_bp_metasync(struct buf *bp, void *data);
442 
443 struct vtruncbuf_info {
444 	struct vnode *vp;
445 	off_t	truncloffset;
446 	int	clean;
447 };
448 
449 int
450 vtruncbuf(struct vnode *vp, off_t length, int blksize)
451 {
452 	struct vtruncbuf_info info;
453 	const char *filename;
454 	int count;
455 
456 	/*
457 	 * Round up to the *next* block, then destroy the buffers in question.
458 	 * Since we are only removing some of the buffers we must rely on the
459 	 * scan count to determine whether a loop is necessary.
460 	 */
461 	if ((count = (int)(length % blksize)) != 0)
462 		info.truncloffset = length + (blksize - count);
463 	else
464 		info.truncloffset = length;
465 	info.vp = vp;
466 
467 	lwkt_gettoken(&vp->v_token);
468 	do {
469 		info.clean = 1;
470 		count = RB_SCAN(buf_rb_tree, &vp->v_rbclean_tree,
471 				vtruncbuf_bp_trunc_cmp,
472 				vtruncbuf_bp_trunc, &info);
473 		info.clean = 0;
474 		count += RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
475 				vtruncbuf_bp_trunc_cmp,
476 				vtruncbuf_bp_trunc, &info);
477 	} while(count);
478 
479 	/*
480 	 * For safety, fsync any remaining metadata if the file is not being
481 	 * truncated to 0.  Since the metadata does not represent the entire
482 	 * dirty list we have to rely on the hit count to ensure that we get
483 	 * all of it.
484 	 */
485 	if (length > 0) {
486 		do {
487 			count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
488 					vtruncbuf_bp_metasync_cmp,
489 					vtruncbuf_bp_metasync, &info);
490 		} while (count);
491 	}
492 
493 	/*
494 	 * Clean out any left over VM backing store.
495 	 *
496 	 * It is possible to have in-progress I/O from buffers that were
497 	 * not part of the truncation.  This should not happen if we
498 	 * are truncating to 0-length.
499 	 */
500 	vnode_pager_setsize(vp, length);
501 	bio_track_wait(&vp->v_track_write, 0, 0);
502 
503 	/*
504 	 * Debugging only
505 	 */
506 	spin_lock(&vp->v_spin);
507 	filename = TAILQ_FIRST(&vp->v_namecache) ?
508 		   TAILQ_FIRST(&vp->v_namecache)->nc_name : "?";
509 	spin_unlock(&vp->v_spin);
510 
511 	/*
512 	 * Make sure no buffers were instantiated while we were trying
513 	 * to clean out the remaining VM pages.  This could occur due
514 	 * to busy dirty VM pages being flushed out to disk.
515 	 */
516 	do {
517 		info.clean = 1;
518 		count = RB_SCAN(buf_rb_tree, &vp->v_rbclean_tree,
519 				vtruncbuf_bp_trunc_cmp,
520 				vtruncbuf_bp_trunc, &info);
521 		info.clean = 0;
522 		count += RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
523 				vtruncbuf_bp_trunc_cmp,
524 				vtruncbuf_bp_trunc, &info);
525 		if (count) {
526 			kprintf("Warning: vtruncbuf():  Had to re-clean %d "
527 			       "left over buffers in %s\n", count, filename);
528 		}
529 	} while(count);
530 
531 	lwkt_reltoken(&vp->v_token);
532 
533 	return (0);
534 }
535 
536 /*
537  * The callback buffer is beyond the new file EOF and must be destroyed.
538  * Note that the compare function must conform to the RB_SCAN's requirements.
539  */
540 static
541 int
542 vtruncbuf_bp_trunc_cmp(struct buf *bp, void *data)
543 {
544 	struct vtruncbuf_info *info = data;
545 
546 	if (bp->b_loffset >= info->truncloffset)
547 		return(0);
548 	return(-1);
549 }
550 
551 static
552 int
553 vtruncbuf_bp_trunc(struct buf *bp, void *data)
554 {
555 	struct vtruncbuf_info *info = data;
556 
557 	/*
558 	 * Do not try to use a buffer we cannot immediately lock, but sleep
559 	 * anyway to prevent a livelock.  The code will loop until all buffers
560 	 * can be acted upon.
561 	 *
562 	 * We must always revalidate the buffer after locking it to deal
563 	 * with MP races.
564 	 */
565 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
566 		atomic_add_int(&bp->b_refs, 1);
567 		if (BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL) == 0)
568 			BUF_UNLOCK(bp);
569 		atomic_subtract_int(&bp->b_refs, 1);
570 	} else if ((info->clean && (bp->b_flags & B_DELWRI)) ||
571 		   (info->clean == 0 && (bp->b_flags & B_DELWRI) == 0) ||
572 		   bp->b_vp != info->vp ||
573 		   vtruncbuf_bp_trunc_cmp(bp, data)) {
574 		BUF_UNLOCK(bp);
575 	} else {
576 		bremfree(bp);
577 		bp->b_flags |= (B_INVAL | B_RELBUF | B_NOCACHE);
578 		brelse(bp);
579 	}
580 	return(1);
581 }
582 
583 /*
584  * Fsync all meta-data after truncating a file to be non-zero.  Only metadata
585  * blocks (with a negative loffset) are scanned.
586  * Note that the compare function must conform to the RB_SCAN's requirements.
587  */
588 static int
589 vtruncbuf_bp_metasync_cmp(struct buf *bp, void *data __unused)
590 {
591 	if (bp->b_loffset < 0)
592 		return(0);
593 	return(1);
594 }
595 
596 static int
597 vtruncbuf_bp_metasync(struct buf *bp, void *data)
598 {
599 	struct vtruncbuf_info *info = data;
600 
601 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
602 		atomic_add_int(&bp->b_refs, 1);
603 		if (BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL) == 0)
604 			BUF_UNLOCK(bp);
605 		atomic_subtract_int(&bp->b_refs, 1);
606 	} else if ((bp->b_flags & B_DELWRI) == 0 ||
607 		   bp->b_vp != info->vp ||
608 		   vtruncbuf_bp_metasync_cmp(bp, data)) {
609 		BUF_UNLOCK(bp);
610 	} else {
611 		bremfree(bp);
612 		if (bp->b_vp == info->vp)
613 			bawrite(bp);
614 		else
615 			bwrite(bp);
616 	}
617 	return(1);
618 }
619 
620 /*
621  * vfsync - implements a multipass fsync on a file which understands
622  * dependancies and meta-data.  The passed vnode must be locked.  The
623  * waitfor argument may be MNT_WAIT or MNT_NOWAIT, or MNT_LAZY.
624  *
625  * When fsyncing data asynchronously just do one consolidated pass starting
626  * with the most negative block number.  This may not get all the data due
627  * to dependancies.
628  *
629  * When fsyncing data synchronously do a data pass, then a metadata pass,
630  * then do additional data+metadata passes to try to get all the data out.
631  */
632 static int vfsync_wait_output(struct vnode *vp,
633 			    int (*waitoutput)(struct vnode *, struct thread *));
634 static int vfsync_dummy_cmp(struct buf *bp __unused, void *data __unused);
635 static int vfsync_data_only_cmp(struct buf *bp, void *data);
636 static int vfsync_meta_only_cmp(struct buf *bp, void *data);
637 static int vfsync_lazy_range_cmp(struct buf *bp, void *data);
638 static int vfsync_bp(struct buf *bp, void *data);
639 
640 struct vfsync_info {
641 	struct vnode *vp;
642 	int synchronous;
643 	int syncdeps;
644 	int lazycount;
645 	int lazylimit;
646 	int skippedbufs;
647 	int (*checkdef)(struct buf *);
648 	int (*cmpfunc)(struct buf *, void *);
649 };
650 
651 int
652 vfsync(struct vnode *vp, int waitfor, int passes,
653 	int (*checkdef)(struct buf *),
654 	int (*waitoutput)(struct vnode *, struct thread *))
655 {
656 	struct vfsync_info info;
657 	int error;
658 
659 	bzero(&info, sizeof(info));
660 	info.vp = vp;
661 	if ((info.checkdef = checkdef) == NULL)
662 		info.syncdeps = 1;
663 
664 	lwkt_gettoken(&vp->v_token);
665 
666 	switch(waitfor) {
667 	case MNT_LAZY | MNT_NOWAIT:
668 	case MNT_LAZY:
669 		/*
670 		 * Lazy (filesystem syncer typ) Asynchronous plus limit the
671 		 * number of data (not meta) pages we try to flush to 1MB.
672 		 * A non-zero return means that lazy limit was reached.
673 		 */
674 		info.lazylimit = 1024 * 1024;
675 		info.syncdeps = 1;
676 		info.cmpfunc = vfsync_lazy_range_cmp;
677 		error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
678 				vfsync_lazy_range_cmp, vfsync_bp, &info);
679 		info.cmpfunc = vfsync_meta_only_cmp;
680 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
681 			vfsync_meta_only_cmp, vfsync_bp, &info);
682 		if (error == 0)
683 			vp->v_lazyw = 0;
684 		else if (!RB_EMPTY(&vp->v_rbdirty_tree))
685 			vn_syncer_add(vp, 1);
686 		error = 0;
687 		break;
688 	case MNT_NOWAIT:
689 		/*
690 		 * Asynchronous.  Do a data-only pass and a meta-only pass.
691 		 */
692 		info.syncdeps = 1;
693 		info.cmpfunc = vfsync_data_only_cmp;
694 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, vfsync_data_only_cmp,
695 			vfsync_bp, &info);
696 		info.cmpfunc = vfsync_meta_only_cmp;
697 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, vfsync_meta_only_cmp,
698 			vfsync_bp, &info);
699 		error = 0;
700 		break;
701 	default:
702 		/*
703 		 * Synchronous.  Do a data-only pass, then a meta-data+data
704 		 * pass, then additional integrated passes to try to get
705 		 * all the dependancies flushed.
706 		 */
707 		info.cmpfunc = vfsync_data_only_cmp;
708 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, vfsync_data_only_cmp,
709 			vfsync_bp, &info);
710 		error = vfsync_wait_output(vp, waitoutput);
711 		if (error == 0) {
712 			info.skippedbufs = 0;
713 			info.cmpfunc = vfsync_dummy_cmp;
714 			RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
715 				vfsync_bp, &info);
716 			error = vfsync_wait_output(vp, waitoutput);
717 			if (info.skippedbufs) {
718 				kprintf("Warning: vfsync skipped %d dirty "
719 					"bufs in pass2!\n", info.skippedbufs);
720 			}
721 		}
722 		while (error == 0 && passes > 0 &&
723 		       !RB_EMPTY(&vp->v_rbdirty_tree)
724 		) {
725 			if (--passes == 0) {
726 				info.synchronous = 1;
727 				info.syncdeps = 1;
728 			}
729 			info.cmpfunc = vfsync_dummy_cmp;
730 			error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
731 					vfsync_bp, &info);
732 			if (error < 0)
733 				error = -error;
734 			info.syncdeps = 1;
735 			if (error == 0)
736 				error = vfsync_wait_output(vp, waitoutput);
737 		}
738 		break;
739 	}
740 	lwkt_reltoken(&vp->v_token);
741 	return(error);
742 }
743 
744 static int
745 vfsync_wait_output(struct vnode *vp,
746 		   int (*waitoutput)(struct vnode *, struct thread *))
747 {
748 	int error;
749 
750 	error = bio_track_wait(&vp->v_track_write, 0, 0);
751 	if (waitoutput)
752 		error = waitoutput(vp, curthread);
753 	return(error);
754 }
755 
756 static int
757 vfsync_dummy_cmp(struct buf *bp __unused, void *data __unused)
758 {
759 	return(0);
760 }
761 
762 static int
763 vfsync_data_only_cmp(struct buf *bp, void *data)
764 {
765 	if (bp->b_loffset < 0)
766 		return(-1);
767 	return(0);
768 }
769 
770 static int
771 vfsync_meta_only_cmp(struct buf *bp, void *data)
772 {
773 	if (bp->b_loffset < 0)
774 		return(0);
775 	return(1);
776 }
777 
778 static int
779 vfsync_lazy_range_cmp(struct buf *bp, void *data)
780 {
781 	struct vfsync_info *info = data;
782 
783 	if (bp->b_loffset < info->vp->v_lazyw)
784 		return(-1);
785 	return(0);
786 }
787 
788 static int
789 vfsync_bp(struct buf *bp, void *data)
790 {
791 	struct vfsync_info *info = data;
792 	struct vnode *vp = info->vp;
793 	int error;
794 
795 	/*
796 	 * Ignore buffers that we cannot immediately lock.
797 	 */
798 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
799 		++info->skippedbufs;
800 		return(0);
801 	}
802 
803 	/*
804 	 * We must revalidate the buffer after locking.
805 	 */
806 	if ((bp->b_flags & B_DELWRI) == 0 ||
807 	    bp->b_vp != info->vp ||
808 	    info->cmpfunc(bp, data)) {
809 		BUF_UNLOCK(bp);
810 		return(0);
811 	}
812 
813 	/*
814 	 * If syncdeps is not set we do not try to write buffers which have
815 	 * dependancies.
816 	 */
817 	if (!info->synchronous && info->syncdeps == 0 && info->checkdef(bp)) {
818 		BUF_UNLOCK(bp);
819 		return(0);
820 	}
821 
822 	/*
823 	 * B_NEEDCOMMIT (primarily used by NFS) is a state where the buffer
824 	 * has been written but an additional handshake with the device
825 	 * is required before we can dispose of the buffer.  We have no idea
826 	 * how to do this so we have to skip these buffers.
827 	 */
828 	if (bp->b_flags & B_NEEDCOMMIT) {
829 		BUF_UNLOCK(bp);
830 		return(0);
831 	}
832 
833 	/*
834 	 * Ask bioops if it is ok to sync.  If not the VFS may have
835 	 * set B_LOCKED so we have to cycle the buffer.
836 	 */
837 	if (LIST_FIRST(&bp->b_dep) != NULL && buf_checkwrite(bp)) {
838 		bremfree(bp);
839 		brelse(bp);
840 		return(0);
841 	}
842 
843 	if (info->synchronous) {
844 		/*
845 		 * Synchronous flushing.  An error may be returned.
846 		 */
847 		bremfree(bp);
848 		error = bwrite(bp);
849 	} else {
850 		/*
851 		 * Asynchronous flushing.  A negative return value simply
852 		 * stops the scan and is not considered an error.  We use
853 		 * this to support limited MNT_LAZY flushes.
854 		 */
855 		vp->v_lazyw = bp->b_loffset;
856 		bremfree(bp);
857 		info->lazycount += cluster_awrite(bp);
858 		waitrunningbufspace();
859 		vm_wait_nominal();
860 		if (info->lazylimit && info->lazycount >= info->lazylimit)
861 			error = 1;
862 		else
863 			error = 0;
864 	}
865 	return(-error);
866 }
867 
868 /*
869  * Associate a buffer with a vnode.
870  *
871  * MPSAFE
872  */
873 int
874 bgetvp(struct vnode *vp, struct buf *bp, int testsize)
875 {
876 	KASSERT(bp->b_vp == NULL, ("bgetvp: not free"));
877 	KKASSERT((bp->b_flags & (B_HASHED|B_DELWRI|B_VNCLEAN|B_VNDIRTY)) == 0);
878 
879 	/*
880 	 * Insert onto list for new vnode.
881 	 */
882 	lwkt_gettoken(&vp->v_token);
883 
884 	if (buf_rb_hash_RB_INSERT(&vp->v_rbhash_tree, bp)) {
885 		lwkt_reltoken(&vp->v_token);
886 		return (EEXIST);
887 	}
888 
889 	/*
890 	 * Diagnostics (mainly for HAMMER debugging).  Check for
891 	 * overlapping buffers.
892 	 */
893 	if (check_buf_overlap) {
894 		struct buf *bx;
895 		bx = buf_rb_hash_RB_PREV(bp);
896 		if (bx) {
897 			if (bx->b_loffset + bx->b_bufsize > bp->b_loffset) {
898 				kprintf("bgetvp: overlapl %016jx/%d %016jx "
899 					"bx %p bp %p\n",
900 					(intmax_t)bx->b_loffset,
901 					bx->b_bufsize,
902 					(intmax_t)bp->b_loffset,
903 					bx, bp);
904 				if (check_buf_overlap > 1)
905 					panic("bgetvp - overlapping buffer");
906 			}
907 		}
908 		bx = buf_rb_hash_RB_NEXT(bp);
909 		if (bx) {
910 			if (bp->b_loffset + testsize > bx->b_loffset) {
911 				kprintf("bgetvp: overlapr %016jx/%d %016jx "
912 					"bp %p bx %p\n",
913 					(intmax_t)bp->b_loffset,
914 					testsize,
915 					(intmax_t)bx->b_loffset,
916 					bp, bx);
917 				if (check_buf_overlap > 1)
918 					panic("bgetvp - overlapping buffer");
919 			}
920 		}
921 	}
922 	bp->b_vp = vp;
923 	bp->b_flags |= B_HASHED;
924 	bp->b_flags |= B_VNCLEAN;
925 	if (buf_rb_tree_RB_INSERT(&vp->v_rbclean_tree, bp))
926 		panic("reassignbuf: dup lblk/clean vp %p bp %p", vp, bp);
927 	/*vhold(vp);*/
928 	lwkt_reltoken(&vp->v_token);
929 	return(0);
930 }
931 
932 /*
933  * Disassociate a buffer from a vnode.
934  *
935  * MPSAFE
936  */
937 void
938 brelvp(struct buf *bp)
939 {
940 	struct vnode *vp;
941 
942 	KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
943 
944 	/*
945 	 * Delete from old vnode list, if on one.
946 	 */
947 	vp = bp->b_vp;
948 	lwkt_gettoken(&vp->v_token);
949 	if (bp->b_flags & (B_VNDIRTY | B_VNCLEAN)) {
950 		if (bp->b_flags & B_VNDIRTY)
951 			buf_rb_tree_RB_REMOVE(&vp->v_rbdirty_tree, bp);
952 		else
953 			buf_rb_tree_RB_REMOVE(&vp->v_rbclean_tree, bp);
954 		bp->b_flags &= ~(B_VNDIRTY | B_VNCLEAN);
955 	}
956 	if (bp->b_flags & B_HASHED) {
957 		buf_rb_hash_RB_REMOVE(&vp->v_rbhash_tree, bp);
958 		bp->b_flags &= ~B_HASHED;
959 	}
960 	if ((vp->v_flag & VONWORKLST) && RB_EMPTY(&vp->v_rbdirty_tree))
961 		vn_syncer_remove(vp);
962 	bp->b_vp = NULL;
963 
964 	lwkt_reltoken(&vp->v_token);
965 
966 	/*vdrop(vp);*/
967 }
968 
969 /*
970  * Reassign the buffer to the proper clean/dirty list based on B_DELWRI.
971  * This routine is called when the state of the B_DELWRI bit is changed.
972  *
973  * Must be called with vp->v_token held.
974  * MPSAFE
975  */
976 void
977 reassignbuf(struct buf *bp)
978 {
979 	struct vnode *vp = bp->b_vp;
980 	int delay;
981 
982 	ASSERT_LWKT_TOKEN_HELD(&vp->v_token);
983 	++reassignbufcalls;
984 
985 	/*
986 	 * B_PAGING flagged buffers cannot be reassigned because their vp
987 	 * is not fully linked in.
988 	 */
989 	if (bp->b_flags & B_PAGING)
990 		panic("cannot reassign paging buffer");
991 
992 	if (bp->b_flags & B_DELWRI) {
993 		/*
994 		 * Move to the dirty list, add the vnode to the worklist
995 		 */
996 		if (bp->b_flags & B_VNCLEAN) {
997 			buf_rb_tree_RB_REMOVE(&vp->v_rbclean_tree, bp);
998 			bp->b_flags &= ~B_VNCLEAN;
999 		}
1000 		if ((bp->b_flags & B_VNDIRTY) == 0) {
1001 			if (buf_rb_tree_RB_INSERT(&vp->v_rbdirty_tree, bp)) {
1002 				panic("reassignbuf: dup lblk vp %p bp %p",
1003 				      vp, bp);
1004 			}
1005 			bp->b_flags |= B_VNDIRTY;
1006 		}
1007 		if ((vp->v_flag & VONWORKLST) == 0) {
1008 			switch (vp->v_type) {
1009 			case VDIR:
1010 				delay = dirdelay;
1011 				break;
1012 			case VCHR:
1013 			case VBLK:
1014 				if (vp->v_rdev &&
1015 				    vp->v_rdev->si_mountpoint != NULL) {
1016 					delay = metadelay;
1017 					break;
1018 				}
1019 				/* fall through */
1020 			default:
1021 				delay = filedelay;
1022 			}
1023 			vn_syncer_add(vp, delay);
1024 		}
1025 	} else {
1026 		/*
1027 		 * Move to the clean list, remove the vnode from the worklist
1028 		 * if no dirty blocks remain.
1029 		 */
1030 		if (bp->b_flags & B_VNDIRTY) {
1031 			buf_rb_tree_RB_REMOVE(&vp->v_rbdirty_tree, bp);
1032 			bp->b_flags &= ~B_VNDIRTY;
1033 		}
1034 		if ((bp->b_flags & B_VNCLEAN) == 0) {
1035 			if (buf_rb_tree_RB_INSERT(&vp->v_rbclean_tree, bp)) {
1036 				panic("reassignbuf: dup lblk vp %p bp %p",
1037 				      vp, bp);
1038 			}
1039 			bp->b_flags |= B_VNCLEAN;
1040 		}
1041 		if ((vp->v_flag & VONWORKLST) &&
1042 		    RB_EMPTY(&vp->v_rbdirty_tree)) {
1043 			vn_syncer_remove(vp);
1044 		}
1045 	}
1046 }
1047 
1048 /*
1049  * Create a vnode for a block device.  Used for mounting the root file
1050  * system.
1051  *
1052  * A vref()'d vnode is returned.
1053  */
1054 extern struct vop_ops *devfs_vnode_dev_vops_p;
1055 int
1056 bdevvp(cdev_t dev, struct vnode **vpp)
1057 {
1058 	struct vnode *vp;
1059 	struct vnode *nvp;
1060 	int error;
1061 
1062 	if (dev == NULL) {
1063 		*vpp = NULLVP;
1064 		return (ENXIO);
1065 	}
1066 	error = getspecialvnode(VT_NON, NULL, &devfs_vnode_dev_vops_p,
1067 				&nvp, 0, 0);
1068 	if (error) {
1069 		*vpp = NULLVP;
1070 		return (error);
1071 	}
1072 	vp = nvp;
1073 	vp->v_type = VCHR;
1074 #if 0
1075 	vp->v_rdev = dev;
1076 #endif
1077 	v_associate_rdev(vp, dev);
1078 	vp->v_umajor = dev->si_umajor;
1079 	vp->v_uminor = dev->si_uminor;
1080 	vx_unlock(vp);
1081 	*vpp = vp;
1082 	return (0);
1083 }
1084 
1085 int
1086 v_associate_rdev(struct vnode *vp, cdev_t dev)
1087 {
1088 	if (dev == NULL)
1089 		return(ENXIO);
1090 	if (dev_is_good(dev) == 0)
1091 		return(ENXIO);
1092 	KKASSERT(vp->v_rdev == NULL);
1093 	vp->v_rdev = reference_dev(dev);
1094 	lwkt_gettoken(&spechash_token);
1095 	SLIST_INSERT_HEAD(&dev->si_hlist, vp, v_cdevnext);
1096 	lwkt_reltoken(&spechash_token);
1097 	return(0);
1098 }
1099 
1100 void
1101 v_release_rdev(struct vnode *vp)
1102 {
1103 	cdev_t dev;
1104 
1105 	if ((dev = vp->v_rdev) != NULL) {
1106 		lwkt_gettoken(&spechash_token);
1107 		SLIST_REMOVE(&dev->si_hlist, vp, vnode, v_cdevnext);
1108 		vp->v_rdev = NULL;
1109 		release_dev(dev);
1110 		lwkt_reltoken(&spechash_token);
1111 	}
1112 }
1113 
1114 /*
1115  * Add a vnode to the alias list hung off the cdev_t.  We only associate
1116  * the device number with the vnode.  The actual device is not associated
1117  * until the vnode is opened (usually in spec_open()), and will be
1118  * disassociated on last close.
1119  */
1120 void
1121 addaliasu(struct vnode *nvp, int x, int y)
1122 {
1123 	if (nvp->v_type != VBLK && nvp->v_type != VCHR)
1124 		panic("addaliasu on non-special vnode");
1125 	nvp->v_umajor = x;
1126 	nvp->v_uminor = y;
1127 }
1128 
1129 /*
1130  * Simple call that a filesystem can make to try to get rid of a
1131  * vnode.  It will fail if anyone is referencing the vnode (including
1132  * the caller).
1133  *
1134  * The filesystem can check whether its in-memory inode structure still
1135  * references the vp on return.
1136  */
1137 void
1138 vclean_unlocked(struct vnode *vp)
1139 {
1140 	vx_get(vp);
1141 	if (sysref_isactive(&vp->v_sysref) == 0)
1142 		vgone_vxlocked(vp);
1143 	vx_put(vp);
1144 }
1145 
1146 /*
1147  * Disassociate a vnode from its underlying filesystem.
1148  *
1149  * The vnode must be VX locked and referenced.  In all normal situations
1150  * there are no active references.  If vclean_vxlocked() is called while
1151  * there are active references, the vnode is being ripped out and we have
1152  * to call VOP_CLOSE() as appropriate before we can reclaim it.
1153  */
1154 void
1155 vclean_vxlocked(struct vnode *vp, int flags)
1156 {
1157 	int active;
1158 	int n;
1159 	vm_object_t object;
1160 	struct namecache *ncp;
1161 
1162 	/*
1163 	 * If the vnode has already been reclaimed we have nothing to do.
1164 	 */
1165 	if (vp->v_flag & VRECLAIMED)
1166 		return;
1167 	vsetflags(vp, VRECLAIMED);
1168 
1169 	if (verbose_reclaims) {
1170 		if ((ncp = TAILQ_FIRST(&vp->v_namecache)) != NULL)
1171 			kprintf("Debug: reclaim %p %s\n", vp, ncp->nc_name);
1172 	}
1173 
1174 	/*
1175 	 * Scrap the vfs cache
1176 	 */
1177 	while (cache_inval_vp(vp, 0) != 0) {
1178 		kprintf("Warning: vnode %p clean/cache_resolution "
1179 			"race detected\n", vp);
1180 		tsleep(vp, 0, "vclninv", 2);
1181 	}
1182 
1183 	/*
1184 	 * Check to see if the vnode is in use. If so we have to reference it
1185 	 * before we clean it out so that its count cannot fall to zero and
1186 	 * generate a race against ourselves to recycle it.
1187 	 */
1188 	active = sysref_isactive(&vp->v_sysref);
1189 
1190 	/*
1191 	 * Clean out any buffers associated with the vnode and destroy its
1192 	 * object, if it has one.
1193 	 */
1194 	vinvalbuf(vp, V_SAVE, 0, 0);
1195 
1196 	/*
1197 	 * If purging an active vnode (typically during a forced unmount
1198 	 * or reboot), it must be closed and deactivated before being
1199 	 * reclaimed.  This isn't really all that safe, but what can
1200 	 * we do? XXX.
1201 	 *
1202 	 * Note that neither of these routines unlocks the vnode.
1203 	 */
1204 	if (active && (flags & DOCLOSE)) {
1205 		while ((n = vp->v_opencount) != 0) {
1206 			if (vp->v_writecount)
1207 				VOP_CLOSE(vp, FWRITE|FNONBLOCK);
1208 			else
1209 				VOP_CLOSE(vp, FNONBLOCK);
1210 			if (vp->v_opencount == n) {
1211 				kprintf("Warning: unable to force-close"
1212 				       " vnode %p\n", vp);
1213 				break;
1214 			}
1215 		}
1216 	}
1217 
1218 	/*
1219 	 * If the vnode has not been deactivated, deactivated it.  Deactivation
1220 	 * can create new buffers and VM pages so we have to call vinvalbuf()
1221 	 * again to make sure they all get flushed.
1222 	 *
1223 	 * This can occur if a file with a link count of 0 needs to be
1224 	 * truncated.
1225 	 *
1226 	 * If the vnode is already dead don't try to deactivate it.
1227 	 */
1228 	if ((vp->v_flag & VINACTIVE) == 0) {
1229 		vsetflags(vp, VINACTIVE);
1230 		if (vp->v_mount)
1231 			VOP_INACTIVE(vp);
1232 		vinvalbuf(vp, V_SAVE, 0, 0);
1233 	}
1234 
1235 	/*
1236 	 * If the vnode has an object, destroy it.
1237 	 */
1238 	while ((object = vp->v_object) != NULL) {
1239 		vm_object_hold(object);
1240 		if (object == vp->v_object)
1241 			break;
1242 		vm_object_drop(object);
1243 	}
1244 
1245 	if (object != NULL) {
1246 		if (object->ref_count == 0) {
1247 			if ((object->flags & OBJ_DEAD) == 0)
1248 				vm_object_terminate(object);
1249 			vm_object_drop(object);
1250 			vclrflags(vp, VOBJBUF);
1251 		} else {
1252 			vm_pager_deallocate(object);
1253 			vclrflags(vp, VOBJBUF);
1254 			vm_object_drop(object);
1255 		}
1256 	}
1257 	KKASSERT((vp->v_flag & VOBJBUF) == 0);
1258 
1259 	/*
1260 	 * Reclaim the vnode if not already dead.
1261 	 */
1262 	if (vp->v_mount && VOP_RECLAIM(vp))
1263 		panic("vclean: cannot reclaim");
1264 
1265 	/*
1266 	 * Done with purge, notify sleepers of the grim news.
1267 	 */
1268 	vp->v_ops = &dead_vnode_vops_p;
1269 	vn_gone(vp);
1270 	vp->v_tag = VT_NON;
1271 
1272 	/*
1273 	 * If we are destroying an active vnode, reactivate it now that
1274 	 * we have reassociated it with deadfs.  This prevents the system
1275 	 * from crashing on the vnode due to it being unexpectedly marked
1276 	 * as inactive or reclaimed.
1277 	 */
1278 	if (active && (flags & DOCLOSE)) {
1279 		vclrflags(vp, VINACTIVE | VRECLAIMED);
1280 	}
1281 }
1282 
1283 /*
1284  * Eliminate all activity associated with the requested vnode
1285  * and with all vnodes aliased to the requested vnode.
1286  *
1287  * The vnode must be referenced but should not be locked.
1288  */
1289 int
1290 vrevoke(struct vnode *vp, struct ucred *cred)
1291 {
1292 	struct vnode *vq;
1293 	struct vnode *vqn;
1294 	cdev_t dev;
1295 	int error;
1296 
1297 	/*
1298 	 * If the vnode has a device association, scrap all vnodes associated
1299 	 * with the device.  Don't let the device disappear on us while we
1300 	 * are scrapping the vnodes.
1301 	 *
1302 	 * The passed vp will probably show up in the list, do not VX lock
1303 	 * it twice!
1304 	 *
1305 	 * Releasing the vnode's rdev here can mess up specfs's call to
1306 	 * device close, so don't do it.  The vnode has been disassociated
1307 	 * and the device will be closed after the last ref on the related
1308 	 * fp goes away (if not still open by e.g. the kernel).
1309 	 */
1310 	if (vp->v_type != VCHR) {
1311 		error = fdrevoke(vp, DTYPE_VNODE, cred);
1312 		return (error);
1313 	}
1314 	if ((dev = vp->v_rdev) == NULL) {
1315 		return(0);
1316 	}
1317 	reference_dev(dev);
1318 	lwkt_gettoken(&spechash_token);
1319 
1320 restart:
1321 	vqn = SLIST_FIRST(&dev->si_hlist);
1322 	if (vqn)
1323 		vhold(vqn);
1324 	while ((vq = vqn) != NULL) {
1325 		if (sysref_isactive(&vq->v_sysref)) {
1326 			vref(vq);
1327 			fdrevoke(vq, DTYPE_VNODE, cred);
1328 			/*v_release_rdev(vq);*/
1329 			vrele(vq);
1330 			if (vq->v_rdev != dev) {
1331 				vdrop(vq);
1332 				goto restart;
1333 			}
1334 		}
1335 		vqn = SLIST_NEXT(vq, v_cdevnext);
1336 		if (vqn)
1337 			vhold(vqn);
1338 		vdrop(vq);
1339 	}
1340 	lwkt_reltoken(&spechash_token);
1341 	dev_drevoke(dev);
1342 	release_dev(dev);
1343 	return (0);
1344 }
1345 
1346 /*
1347  * This is called when the object underlying a vnode is being destroyed,
1348  * such as in a remove().  Try to recycle the vnode immediately if the
1349  * only active reference is our reference.
1350  *
1351  * Directory vnodes in the namecache with children cannot be immediately
1352  * recycled because numerous VOP_N*() ops require them to be stable.
1353  *
1354  * To avoid recursive recycling from VOP_INACTIVE implemenetations this
1355  * function is a NOP if VRECLAIMED is already set.
1356  */
1357 int
1358 vrecycle(struct vnode *vp)
1359 {
1360 	if (vp->v_sysref.refcnt <= 1 && (vp->v_flag & VRECLAIMED) == 0) {
1361 		if (cache_inval_vp_nonblock(vp))
1362 			return(0);
1363 		vgone_vxlocked(vp);
1364 		return (1);
1365 	}
1366 	return (0);
1367 }
1368 
1369 /*
1370  * Return the maximum I/O size allowed for strategy calls on VP.
1371  *
1372  * If vp is VCHR or VBLK we dive the device, otherwise we use
1373  * the vp's mount info.
1374  *
1375  * The returned value is clamped at MAXPHYS as most callers cannot use
1376  * buffers larger than that size.
1377  */
1378 int
1379 vmaxiosize(struct vnode *vp)
1380 {
1381 	int maxiosize;
1382 
1383 	if (vp->v_type == VBLK || vp->v_type == VCHR)
1384 		maxiosize = vp->v_rdev->si_iosize_max;
1385 	else
1386 		maxiosize = vp->v_mount->mnt_iosize_max;
1387 
1388 	if (maxiosize > MAXPHYS)
1389 		maxiosize = MAXPHYS;
1390 	return (maxiosize);
1391 }
1392 
1393 /*
1394  * Eliminate all activity associated with a vnode in preparation for reuse.
1395  *
1396  * The vnode must be VX locked and refd and will remain VX locked and refd
1397  * on return.  This routine may be called with the vnode in any state, as
1398  * long as it is VX locked.  The vnode will be cleaned out and marked
1399  * VRECLAIMED but will not actually be reused until all existing refs and
1400  * holds go away.
1401  *
1402  * NOTE: This routine may be called on a vnode which has not yet been
1403  * already been deactivated (VOP_INACTIVE), or on a vnode which has
1404  * already been reclaimed.
1405  *
1406  * This routine is not responsible for placing us back on the freelist.
1407  * Instead, it happens automatically when the caller releases the VX lock
1408  * (assuming there aren't any other references).
1409  */
1410 void
1411 vgone_vxlocked(struct vnode *vp)
1412 {
1413 	/*
1414 	 * assert that the VX lock is held.  This is an absolute requirement
1415 	 * now for vgone_vxlocked() to be called.
1416 	 */
1417 	KKASSERT(vp->v_lock.lk_exclusivecount == 1);
1418 
1419 	/*
1420 	 * Clean out the filesystem specific data and set the VRECLAIMED
1421 	 * bit.  Also deactivate the vnode if necessary.
1422 	 */
1423 	vclean_vxlocked(vp, DOCLOSE);
1424 
1425 	/*
1426 	 * Delete from old mount point vnode list, if on one.
1427 	 */
1428 	if (vp->v_mount != NULL) {
1429 		KKASSERT(vp->v_data == NULL);
1430 		insmntque(vp, NULL);
1431 	}
1432 
1433 	/*
1434 	 * If special device, remove it from special device alias list
1435 	 * if it is on one.  This should normally only occur if a vnode is
1436 	 * being revoked as the device should otherwise have been released
1437 	 * naturally.
1438 	 */
1439 	if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_rdev != NULL) {
1440 		v_release_rdev(vp);
1441 	}
1442 
1443 	/*
1444 	 * Set us to VBAD
1445 	 */
1446 	vp->v_type = VBAD;
1447 }
1448 
1449 /*
1450  * Lookup a vnode by device number.
1451  *
1452  * Returns non-zero and *vpp set to a vref'd vnode on success.
1453  * Returns zero on failure.
1454  */
1455 int
1456 vfinddev(cdev_t dev, enum vtype type, struct vnode **vpp)
1457 {
1458 	struct vnode *vp;
1459 
1460 	lwkt_gettoken(&spechash_token);
1461 	SLIST_FOREACH(vp, &dev->si_hlist, v_cdevnext) {
1462 		if (type == vp->v_type) {
1463 			*vpp = vp;
1464 			vref(vp);
1465 			lwkt_reltoken(&spechash_token);
1466 			return (1);
1467 		}
1468 	}
1469 	lwkt_reltoken(&spechash_token);
1470 	return (0);
1471 }
1472 
1473 /*
1474  * Calculate the total number of references to a special device.  This
1475  * routine may only be called for VBLK and VCHR vnodes since v_rdev is
1476  * an overloaded field.  Since udev2dev can now return NULL, we have
1477  * to check for a NULL v_rdev.
1478  */
1479 int
1480 count_dev(cdev_t dev)
1481 {
1482 	struct vnode *vp;
1483 	int count = 0;
1484 
1485 	if (SLIST_FIRST(&dev->si_hlist)) {
1486 		lwkt_gettoken(&spechash_token);
1487 		SLIST_FOREACH(vp, &dev->si_hlist, v_cdevnext) {
1488 			count += vp->v_opencount;
1489 		}
1490 		lwkt_reltoken(&spechash_token);
1491 	}
1492 	return(count);
1493 }
1494 
1495 int
1496 vcount(struct vnode *vp)
1497 {
1498 	if (vp->v_rdev == NULL)
1499 		return(0);
1500 	return(count_dev(vp->v_rdev));
1501 }
1502 
1503 /*
1504  * Initialize VMIO for a vnode.  This routine MUST be called before a
1505  * VFS can issue buffer cache ops on a vnode.  It is typically called
1506  * when a vnode is initialized from its inode.
1507  */
1508 int
1509 vinitvmio(struct vnode *vp, off_t filesize, int blksize, int boff)
1510 {
1511 	vm_object_t object;
1512 	int error = 0;
1513 
1514 retry:
1515 	while ((object = vp->v_object) != NULL) {
1516 		vm_object_hold(object);
1517 		if (object == vp->v_object)
1518 			break;
1519 		vm_object_drop(object);
1520 	}
1521 
1522 	if (object == NULL) {
1523 		object = vnode_pager_alloc(vp, filesize, 0, 0, blksize, boff);
1524 
1525 		/*
1526 		 * Dereference the reference we just created.  This assumes
1527 		 * that the object is associated with the vp.
1528 		 */
1529 		vm_object_hold(object);
1530 		object->ref_count--;
1531 		vrele(vp);
1532 	} else {
1533 		if (object->flags & OBJ_DEAD) {
1534 			vn_unlock(vp);
1535 			if (vp->v_object == object)
1536 				vm_object_dead_sleep(object, "vodead");
1537 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1538 			vm_object_drop(object);
1539 			goto retry;
1540 		}
1541 	}
1542 	KASSERT(vp->v_object != NULL, ("vinitvmio: NULL object"));
1543 	vsetflags(vp, VOBJBUF);
1544 	vm_object_drop(object);
1545 
1546 	return (error);
1547 }
1548 
1549 
1550 /*
1551  * Print out a description of a vnode.
1552  */
1553 static char *typename[] =
1554 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"};
1555 
1556 void
1557 vprint(char *label, struct vnode *vp)
1558 {
1559 	char buf[96];
1560 
1561 	if (label != NULL)
1562 		kprintf("%s: %p: ", label, (void *)vp);
1563 	else
1564 		kprintf("%p: ", (void *)vp);
1565 	kprintf("type %s, sysrefs %d, writecount %d, holdcnt %d,",
1566 		typename[vp->v_type],
1567 		vp->v_sysref.refcnt, vp->v_writecount, vp->v_auxrefs);
1568 	buf[0] = '\0';
1569 	if (vp->v_flag & VROOT)
1570 		strcat(buf, "|VROOT");
1571 	if (vp->v_flag & VPFSROOT)
1572 		strcat(buf, "|VPFSROOT");
1573 	if (vp->v_flag & VTEXT)
1574 		strcat(buf, "|VTEXT");
1575 	if (vp->v_flag & VSYSTEM)
1576 		strcat(buf, "|VSYSTEM");
1577 	if (vp->v_flag & VFREE)
1578 		strcat(buf, "|VFREE");
1579 	if (vp->v_flag & VOBJBUF)
1580 		strcat(buf, "|VOBJBUF");
1581 	if (buf[0] != '\0')
1582 		kprintf(" flags (%s)", &buf[1]);
1583 	if (vp->v_data == NULL) {
1584 		kprintf("\n");
1585 	} else {
1586 		kprintf("\n\t");
1587 		VOP_PRINT(vp);
1588 	}
1589 }
1590 
1591 /*
1592  * Do the usual access checking.
1593  * file_mode, uid and gid are from the vnode in question,
1594  * while acc_mode and cred are from the VOP_ACCESS parameter list
1595  */
1596 int
1597 vaccess(enum vtype type, mode_t file_mode, uid_t uid, gid_t gid,
1598     mode_t acc_mode, struct ucred *cred)
1599 {
1600 	mode_t mask;
1601 	int ismember;
1602 
1603 	/*
1604 	 * Super-user always gets read/write access, but execute access depends
1605 	 * on at least one execute bit being set.
1606 	 */
1607 	if (priv_check_cred(cred, PRIV_ROOT, 0) == 0) {
1608 		if ((acc_mode & VEXEC) && type != VDIR &&
1609 		    (file_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)
1610 			return (EACCES);
1611 		return (0);
1612 	}
1613 
1614 	mask = 0;
1615 
1616 	/* Otherwise, check the owner. */
1617 	if (cred->cr_uid == uid) {
1618 		if (acc_mode & VEXEC)
1619 			mask |= S_IXUSR;
1620 		if (acc_mode & VREAD)
1621 			mask |= S_IRUSR;
1622 		if (acc_mode & VWRITE)
1623 			mask |= S_IWUSR;
1624 		return ((file_mode & mask) == mask ? 0 : EACCES);
1625 	}
1626 
1627 	/* Otherwise, check the groups. */
1628 	ismember = groupmember(gid, cred);
1629 	if (cred->cr_svgid == gid || ismember) {
1630 		if (acc_mode & VEXEC)
1631 			mask |= S_IXGRP;
1632 		if (acc_mode & VREAD)
1633 			mask |= S_IRGRP;
1634 		if (acc_mode & VWRITE)
1635 			mask |= S_IWGRP;
1636 		return ((file_mode & mask) == mask ? 0 : EACCES);
1637 	}
1638 
1639 	/* Otherwise, check everyone else. */
1640 	if (acc_mode & VEXEC)
1641 		mask |= S_IXOTH;
1642 	if (acc_mode & VREAD)
1643 		mask |= S_IROTH;
1644 	if (acc_mode & VWRITE)
1645 		mask |= S_IWOTH;
1646 	return ((file_mode & mask) == mask ? 0 : EACCES);
1647 }
1648 
1649 #ifdef DDB
1650 #include <ddb/ddb.h>
1651 
1652 static int db_show_locked_vnodes(struct mount *mp, void *data);
1653 
1654 /*
1655  * List all of the locked vnodes in the system.
1656  * Called when debugging the kernel.
1657  */
1658 DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
1659 {
1660 	kprintf("Locked vnodes\n");
1661 	mountlist_scan(db_show_locked_vnodes, NULL,
1662 			MNTSCAN_FORWARD|MNTSCAN_NOBUSY);
1663 }
1664 
1665 static int
1666 db_show_locked_vnodes(struct mount *mp, void *data __unused)
1667 {
1668 	struct vnode *vp;
1669 
1670 	TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
1671 		if (vn_islocked(vp))
1672 			vprint(NULL, vp);
1673 	}
1674 	return(0);
1675 }
1676 #endif
1677 
1678 /*
1679  * Top level filesystem related information gathering.
1680  */
1681 static int	sysctl_ovfs_conf (SYSCTL_HANDLER_ARGS);
1682 
1683 static int
1684 vfs_sysctl(SYSCTL_HANDLER_ARGS)
1685 {
1686 	int *name = (int *)arg1 - 1;	/* XXX */
1687 	u_int namelen = arg2 + 1;	/* XXX */
1688 	struct vfsconf *vfsp;
1689 	int maxtypenum;
1690 
1691 #if 1 || defined(COMPAT_PRELITE2)
1692 	/* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
1693 	if (namelen == 1)
1694 		return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
1695 #endif
1696 
1697 #ifdef notyet
1698 	/* all sysctl names at this level are at least name and field */
1699 	if (namelen < 2)
1700 		return (ENOTDIR);		/* overloaded */
1701 	if (name[0] != VFS_GENERIC) {
1702 		vfsp = vfsconf_find_by_typenum(name[0]);
1703 		if (vfsp == NULL)
1704 			return (EOPNOTSUPP);
1705 		return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1,
1706 		    oldp, oldlenp, newp, newlen, p));
1707 	}
1708 #endif
1709 	switch (name[1]) {
1710 	case VFS_MAXTYPENUM:
1711 		if (namelen != 2)
1712 			return (ENOTDIR);
1713 		maxtypenum = vfsconf_get_maxtypenum();
1714 		return (SYSCTL_OUT(req, &maxtypenum, sizeof(maxtypenum)));
1715 	case VFS_CONF:
1716 		if (namelen != 3)
1717 			return (ENOTDIR);	/* overloaded */
1718 		vfsp = vfsconf_find_by_typenum(name[2]);
1719 		if (vfsp == NULL)
1720 			return (EOPNOTSUPP);
1721 		return (SYSCTL_OUT(req, vfsp, sizeof *vfsp));
1722 	}
1723 	return (EOPNOTSUPP);
1724 }
1725 
1726 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl,
1727 	"Generic filesystem");
1728 
1729 #if 1 || defined(COMPAT_PRELITE2)
1730 
1731 static int
1732 sysctl_ovfs_conf_iter(struct vfsconf *vfsp, void *data)
1733 {
1734 	int error;
1735 	struct ovfsconf ovfs;
1736 	struct sysctl_req *req = (struct sysctl_req*) data;
1737 
1738 	bzero(&ovfs, sizeof(ovfs));
1739 	ovfs.vfc_vfsops = vfsp->vfc_vfsops;	/* XXX used as flag */
1740 	strcpy(ovfs.vfc_name, vfsp->vfc_name);
1741 	ovfs.vfc_index = vfsp->vfc_typenum;
1742 	ovfs.vfc_refcount = vfsp->vfc_refcount;
1743 	ovfs.vfc_flags = vfsp->vfc_flags;
1744 	error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
1745 	if (error)
1746 		return error; /* abort iteration with error code */
1747 	else
1748 		return 0; /* continue iterating with next element */
1749 }
1750 
1751 static int
1752 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
1753 {
1754 	return vfsconf_each(sysctl_ovfs_conf_iter, (void*)req);
1755 }
1756 
1757 #endif /* 1 || COMPAT_PRELITE2 */
1758 
1759 /*
1760  * Check to see if a filesystem is mounted on a block device.
1761  */
1762 int
1763 vfs_mountedon(struct vnode *vp)
1764 {
1765 	cdev_t dev;
1766 
1767 	if ((dev = vp->v_rdev) == NULL) {
1768 /*		if (vp->v_type != VBLK)
1769 			dev = get_dev(vp->v_uminor, vp->v_umajor); */
1770 	}
1771 	if (dev != NULL && dev->si_mountpoint)
1772 		return (EBUSY);
1773 	return (0);
1774 }
1775 
1776 /*
1777  * Unmount all filesystems. The list is traversed in reverse order
1778  * of mounting to avoid dependencies.
1779  */
1780 
1781 static int vfs_umountall_callback(struct mount *mp, void *data);
1782 
1783 void
1784 vfs_unmountall(void)
1785 {
1786 	int count;
1787 
1788 	do {
1789 		count = mountlist_scan(vfs_umountall_callback,
1790 					NULL, MNTSCAN_REVERSE|MNTSCAN_NOBUSY);
1791 	} while (count);
1792 }
1793 
1794 static
1795 int
1796 vfs_umountall_callback(struct mount *mp, void *data)
1797 {
1798 	int error;
1799 
1800 	error = dounmount(mp, MNT_FORCE);
1801 	if (error) {
1802 		mountlist_remove(mp);
1803 		kprintf("unmount of filesystem mounted from %s failed (",
1804 			mp->mnt_stat.f_mntfromname);
1805 		if (error == EBUSY)
1806 			kprintf("BUSY)\n");
1807 		else
1808 			kprintf("%d)\n", error);
1809 	}
1810 	return(1);
1811 }
1812 
1813 /*
1814  * Checks the mount flags for parameter mp and put the names comma-separated
1815  * into a string buffer buf with a size limit specified by len.
1816  *
1817  * It returns the number of bytes written into buf, and (*errorp) will be
1818  * set to 0, EINVAL (if passed length is 0), or ENOSPC (supplied buffer was
1819  * not large enough).  The buffer will be 0-terminated if len was not 0.
1820  */
1821 size_t
1822 vfs_flagstostr(int flags, const struct mountctl_opt *optp,
1823 	       char *buf, size_t len, int *errorp)
1824 {
1825 	static const struct mountctl_opt optnames[] = {
1826 		{ MNT_ASYNC,            "asynchronous" },
1827 		{ MNT_EXPORTED,         "NFS exported" },
1828 		{ MNT_LOCAL,            "local" },
1829 		{ MNT_NOATIME,          "noatime" },
1830 		{ MNT_NODEV,            "nodev" },
1831 		{ MNT_NOEXEC,           "noexec" },
1832 		{ MNT_NOSUID,           "nosuid" },
1833 		{ MNT_NOSYMFOLLOW,      "nosymfollow" },
1834 		{ MNT_QUOTA,            "with-quotas" },
1835 		{ MNT_RDONLY,           "read-only" },
1836 		{ MNT_SYNCHRONOUS,      "synchronous" },
1837 		{ MNT_UNION,            "union" },
1838 		{ MNT_NOCLUSTERR,       "noclusterr" },
1839 		{ MNT_NOCLUSTERW,       "noclusterw" },
1840 		{ MNT_SUIDDIR,          "suiddir" },
1841 		{ MNT_SOFTDEP,          "soft-updates" },
1842 		{ MNT_IGNORE,           "ignore" },
1843 		{ 0,			NULL}
1844 	};
1845 	int bwritten;
1846 	int bleft;
1847 	int optlen;
1848 	int actsize;
1849 
1850 	*errorp = 0;
1851 	bwritten = 0;
1852 	bleft = len - 1;	/* leave room for trailing \0 */
1853 
1854 	/*
1855 	 * Checks the size of the string. If it contains
1856 	 * any data, then we will append the new flags to
1857 	 * it.
1858 	 */
1859 	actsize = strlen(buf);
1860 	if (actsize > 0)
1861 		buf += actsize;
1862 
1863 	/* Default flags if no flags passed */
1864 	if (optp == NULL)
1865 		optp = optnames;
1866 
1867 	if (bleft < 0) {	/* degenerate case, 0-length buffer */
1868 		*errorp = EINVAL;
1869 		return(0);
1870 	}
1871 
1872 	for (; flags && optp->o_opt; ++optp) {
1873 		if ((flags & optp->o_opt) == 0)
1874 			continue;
1875 		optlen = strlen(optp->o_name);
1876 		if (bwritten || actsize > 0) {
1877 			if (bleft < 2) {
1878 				*errorp = ENOSPC;
1879 				break;
1880 			}
1881 			buf[bwritten++] = ',';
1882 			buf[bwritten++] = ' ';
1883 			bleft -= 2;
1884 		}
1885 		if (bleft < optlen) {
1886 			*errorp = ENOSPC;
1887 			break;
1888 		}
1889 		bcopy(optp->o_name, buf + bwritten, optlen);
1890 		bwritten += optlen;
1891 		bleft -= optlen;
1892 		flags &= ~optp->o_opt;
1893 	}
1894 
1895 	/*
1896 	 * Space already reserved for trailing \0
1897 	 */
1898 	buf[bwritten] = 0;
1899 	return (bwritten);
1900 }
1901 
1902 /*
1903  * Build hash lists of net addresses and hang them off the mount point.
1904  * Called by ufs_mount() to set up the lists of export addresses.
1905  */
1906 static int
1907 vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
1908 		const struct export_args *argp)
1909 {
1910 	struct netcred *np;
1911 	struct radix_node_head *rnh;
1912 	int i;
1913 	struct radix_node *rn;
1914 	struct sockaddr *saddr, *smask = NULL;
1915 	struct domain *dom;
1916 	int error;
1917 
1918 	if (argp->ex_addrlen == 0) {
1919 		if (mp->mnt_flag & MNT_DEFEXPORTED)
1920 			return (EPERM);
1921 		np = &nep->ne_defexported;
1922 		np->netc_exflags = argp->ex_flags;
1923 		np->netc_anon = argp->ex_anon;
1924 		np->netc_anon.cr_ref = 1;
1925 		mp->mnt_flag |= MNT_DEFEXPORTED;
1926 		return (0);
1927 	}
1928 
1929 	if (argp->ex_addrlen < 0 || argp->ex_addrlen > MLEN)
1930 		return (EINVAL);
1931 	if (argp->ex_masklen < 0 || argp->ex_masklen > MLEN)
1932 		return (EINVAL);
1933 
1934 	i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
1935 	np = (struct netcred *) kmalloc(i, M_NETADDR, M_WAITOK | M_ZERO);
1936 	saddr = (struct sockaddr *) (np + 1);
1937 	if ((error = copyin(argp->ex_addr, (caddr_t) saddr, argp->ex_addrlen)))
1938 		goto out;
1939 	if (saddr->sa_len > argp->ex_addrlen)
1940 		saddr->sa_len = argp->ex_addrlen;
1941 	if (argp->ex_masklen) {
1942 		smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen);
1943 		error = copyin(argp->ex_mask, (caddr_t)smask, argp->ex_masklen);
1944 		if (error)
1945 			goto out;
1946 		if (smask->sa_len > argp->ex_masklen)
1947 			smask->sa_len = argp->ex_masklen;
1948 	}
1949 	i = saddr->sa_family;
1950 	if ((rnh = nep->ne_rtable[i]) == NULL) {
1951 		/*
1952 		 * Seems silly to initialize every AF when most are not used,
1953 		 * do so on demand here
1954 		 */
1955 		SLIST_FOREACH(dom, &domains, dom_next)
1956 			if (dom->dom_family == i && dom->dom_rtattach) {
1957 				dom->dom_rtattach((void **) &nep->ne_rtable[i],
1958 				    dom->dom_rtoffset);
1959 				break;
1960 			}
1961 		if ((rnh = nep->ne_rtable[i]) == NULL) {
1962 			error = ENOBUFS;
1963 			goto out;
1964 		}
1965 	}
1966 	rn = (*rnh->rnh_addaddr) ((char *) saddr, (char *) smask, rnh,
1967 	    np->netc_rnodes);
1968 	if (rn == NULL || np != (struct netcred *) rn) {	/* already exists */
1969 		error = EPERM;
1970 		goto out;
1971 	}
1972 	np->netc_exflags = argp->ex_flags;
1973 	np->netc_anon = argp->ex_anon;
1974 	np->netc_anon.cr_ref = 1;
1975 	return (0);
1976 out:
1977 	kfree(np, M_NETADDR);
1978 	return (error);
1979 }
1980 
1981 /* ARGSUSED */
1982 static int
1983 vfs_free_netcred(struct radix_node *rn, void *w)
1984 {
1985 	struct radix_node_head *rnh = (struct radix_node_head *) w;
1986 
1987 	(*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
1988 	kfree((caddr_t) rn, M_NETADDR);
1989 	return (0);
1990 }
1991 
1992 /*
1993  * Free the net address hash lists that are hanging off the mount points.
1994  */
1995 static void
1996 vfs_free_addrlist(struct netexport *nep)
1997 {
1998 	int i;
1999 	struct radix_node_head *rnh;
2000 
2001 	for (i = 0; i <= AF_MAX; i++)
2002 		if ((rnh = nep->ne_rtable[i])) {
2003 			(*rnh->rnh_walktree) (rnh, vfs_free_netcred,
2004 			    (caddr_t) rnh);
2005 			kfree((caddr_t) rnh, M_RTABLE);
2006 			nep->ne_rtable[i] = 0;
2007 		}
2008 }
2009 
2010 int
2011 vfs_export(struct mount *mp, struct netexport *nep,
2012 	   const struct export_args *argp)
2013 {
2014 	int error;
2015 
2016 	if (argp->ex_flags & MNT_DELEXPORT) {
2017 		if (mp->mnt_flag & MNT_EXPUBLIC) {
2018 			vfs_setpublicfs(NULL, NULL, NULL);
2019 			mp->mnt_flag &= ~MNT_EXPUBLIC;
2020 		}
2021 		vfs_free_addrlist(nep);
2022 		mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
2023 	}
2024 	if (argp->ex_flags & MNT_EXPORTED) {
2025 		if (argp->ex_flags & MNT_EXPUBLIC) {
2026 			if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
2027 				return (error);
2028 			mp->mnt_flag |= MNT_EXPUBLIC;
2029 		}
2030 		if ((error = vfs_hang_addrlist(mp, nep, argp)))
2031 			return (error);
2032 		mp->mnt_flag |= MNT_EXPORTED;
2033 	}
2034 	return (0);
2035 }
2036 
2037 
2038 /*
2039  * Set the publicly exported filesystem (WebNFS). Currently, only
2040  * one public filesystem is possible in the spec (RFC 2054 and 2055)
2041  */
2042 int
2043 vfs_setpublicfs(struct mount *mp, struct netexport *nep,
2044 		const struct export_args *argp)
2045 {
2046 	int error;
2047 	struct vnode *rvp;
2048 	char *cp;
2049 
2050 	/*
2051 	 * mp == NULL -> invalidate the current info, the FS is
2052 	 * no longer exported. May be called from either vfs_export
2053 	 * or unmount, so check if it hasn't already been done.
2054 	 */
2055 	if (mp == NULL) {
2056 		if (nfs_pub.np_valid) {
2057 			nfs_pub.np_valid = 0;
2058 			if (nfs_pub.np_index != NULL) {
2059 				kfree(nfs_pub.np_index, M_TEMP);
2060 				nfs_pub.np_index = NULL;
2061 			}
2062 		}
2063 		return (0);
2064 	}
2065 
2066 	/*
2067 	 * Only one allowed at a time.
2068 	 */
2069 	if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
2070 		return (EBUSY);
2071 
2072 	/*
2073 	 * Get real filehandle for root of exported FS.
2074 	 */
2075 	bzero((caddr_t)&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
2076 	nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
2077 
2078 	if ((error = VFS_ROOT(mp, &rvp)))
2079 		return (error);
2080 
2081 	if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
2082 		return (error);
2083 
2084 	vput(rvp);
2085 
2086 	/*
2087 	 * If an indexfile was specified, pull it in.
2088 	 */
2089 	if (argp->ex_indexfile != NULL) {
2090 		int namelen;
2091 
2092 		error = vn_get_namelen(rvp, &namelen);
2093 		if (error)
2094 			return (error);
2095 		nfs_pub.np_index = kmalloc(namelen, M_TEMP, M_WAITOK);
2096 		error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
2097 		    namelen, NULL);
2098 		if (!error) {
2099 			/*
2100 			 * Check for illegal filenames.
2101 			 */
2102 			for (cp = nfs_pub.np_index; *cp; cp++) {
2103 				if (*cp == '/') {
2104 					error = EINVAL;
2105 					break;
2106 				}
2107 			}
2108 		}
2109 		if (error) {
2110 			kfree(nfs_pub.np_index, M_TEMP);
2111 			return (error);
2112 		}
2113 	}
2114 
2115 	nfs_pub.np_mount = mp;
2116 	nfs_pub.np_valid = 1;
2117 	return (0);
2118 }
2119 
2120 struct netcred *
2121 vfs_export_lookup(struct mount *mp, struct netexport *nep,
2122 		struct sockaddr *nam)
2123 {
2124 	struct netcred *np;
2125 	struct radix_node_head *rnh;
2126 	struct sockaddr *saddr;
2127 
2128 	np = NULL;
2129 	if (mp->mnt_flag & MNT_EXPORTED) {
2130 		/*
2131 		 * Lookup in the export list first.
2132 		 */
2133 		if (nam != NULL) {
2134 			saddr = nam;
2135 			rnh = nep->ne_rtable[saddr->sa_family];
2136 			if (rnh != NULL) {
2137 				np = (struct netcred *)
2138 					(*rnh->rnh_matchaddr)((char *)saddr,
2139 							      rnh);
2140 				if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
2141 					np = NULL;
2142 			}
2143 		}
2144 		/*
2145 		 * If no address match, use the default if it exists.
2146 		 */
2147 		if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
2148 			np = &nep->ne_defexported;
2149 	}
2150 	return (np);
2151 }
2152 
2153 /*
2154  * perform msync on all vnodes under a mount point.  The mount point must
2155  * be locked.  This code is also responsible for lazy-freeing unreferenced
2156  * vnodes whos VM objects no longer contain pages.
2157  *
2158  * NOTE: MNT_WAIT still skips vnodes in the VXLOCK state.
2159  *
2160  * NOTE: XXX VOP_PUTPAGES and friends requires that the vnode be locked,
2161  * but vnode_pager_putpages() doesn't lock the vnode.  We have to do it
2162  * way up in this high level function.
2163  */
2164 static int vfs_msync_scan1(struct mount *mp, struct vnode *vp, void *data);
2165 static int vfs_msync_scan2(struct mount *mp, struct vnode *vp, void *data);
2166 
2167 void
2168 vfs_msync(struct mount *mp, int flags)
2169 {
2170 	int vmsc_flags;
2171 
2172 	/*
2173 	 * tmpfs sets this flag to prevent msync(), sync, and the
2174 	 * filesystem periodic syncer from trying to flush VM pages
2175 	 * to swap.  Only pure memory pressure flushes tmpfs VM pages
2176 	 * to swap.
2177 	 */
2178 	if (mp->mnt_kern_flag & MNTK_NOMSYNC)
2179 		return;
2180 
2181 	/*
2182 	 * Ok, scan the vnodes for work.
2183 	 */
2184 	vmsc_flags = VMSC_GETVP;
2185 	if (flags != MNT_WAIT)
2186 		vmsc_flags |= VMSC_NOWAIT;
2187 	vmntvnodescan(mp, vmsc_flags,
2188 		      vfs_msync_scan1, vfs_msync_scan2,
2189 		      (void *)(intptr_t)flags);
2190 }
2191 
2192 /*
2193  * scan1 is a fast pre-check.  There could be hundreds of thousands of
2194  * vnodes, we cannot afford to do anything heavy weight until we have a
2195  * fairly good indication that there is work to do.
2196  */
2197 static
2198 int
2199 vfs_msync_scan1(struct mount *mp, struct vnode *vp, void *data)
2200 {
2201 	int flags = (int)(intptr_t)data;
2202 
2203 	if ((vp->v_flag & VRECLAIMED) == 0) {
2204 		if (vshouldmsync(vp))
2205 			return(0);	/* call scan2 */
2206 		if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
2207 		    (vp->v_flag & VOBJDIRTY) &&
2208 		    (flags == MNT_WAIT || vn_islocked(vp) == 0)) {
2209 			return(0);	/* call scan2 */
2210 		}
2211 	}
2212 
2213 	/*
2214 	 * do not call scan2, continue the loop
2215 	 */
2216 	return(-1);
2217 }
2218 
2219 /*
2220  * This callback is handed a locked vnode.
2221  */
2222 static
2223 int
2224 vfs_msync_scan2(struct mount *mp, struct vnode *vp, void *data)
2225 {
2226 	vm_object_t obj;
2227 	int flags = (int)(intptr_t)data;
2228 
2229 	if (vp->v_flag & VRECLAIMED)
2230 		return(0);
2231 
2232 	if ((mp->mnt_flag & MNT_RDONLY) == 0 && (vp->v_flag & VOBJDIRTY)) {
2233 		if ((obj = vp->v_object) != NULL) {
2234 			vm_object_page_clean(obj, 0, 0,
2235 			 flags == MNT_WAIT ? OBJPC_SYNC : OBJPC_NOSYNC);
2236 		}
2237 	}
2238 	return(0);
2239 }
2240 
2241 /*
2242  * Wake up anyone interested in vp because it is being revoked.
2243  */
2244 void
2245 vn_gone(struct vnode *vp)
2246 {
2247 	lwkt_gettoken(&vp->v_token);
2248 	KNOTE(&vp->v_pollinfo.vpi_kqinfo.ki_note, NOTE_REVOKE);
2249 	lwkt_reltoken(&vp->v_token);
2250 }
2251 
2252 /*
2253  * extract the cdev_t from a VBLK or VCHR.  The vnode must have been opened
2254  * (or v_rdev might be NULL).
2255  */
2256 cdev_t
2257 vn_todev(struct vnode *vp)
2258 {
2259 	if (vp->v_type != VBLK && vp->v_type != VCHR)
2260 		return (NULL);
2261 	KKASSERT(vp->v_rdev != NULL);
2262 	return (vp->v_rdev);
2263 }
2264 
2265 /*
2266  * Check if vnode represents a disk device.  The vnode does not need to be
2267  * opened.
2268  *
2269  * MPALMOSTSAFE
2270  */
2271 int
2272 vn_isdisk(struct vnode *vp, int *errp)
2273 {
2274 	cdev_t dev;
2275 
2276 	if (vp->v_type != VCHR) {
2277 		if (errp != NULL)
2278 			*errp = ENOTBLK;
2279 		return (0);
2280 	}
2281 
2282 	dev = vp->v_rdev;
2283 
2284 	if (dev == NULL) {
2285 		if (errp != NULL)
2286 			*errp = ENXIO;
2287 		return (0);
2288 	}
2289 	if (dev_is_good(dev) == 0) {
2290 		if (errp != NULL)
2291 			*errp = ENXIO;
2292 		return (0);
2293 	}
2294 	if ((dev_dflags(dev) & D_DISK) == 0) {
2295 		if (errp != NULL)
2296 			*errp = ENOTBLK;
2297 		return (0);
2298 	}
2299 	if (errp != NULL)
2300 		*errp = 0;
2301 	return (1);
2302 }
2303 
2304 int
2305 vn_get_namelen(struct vnode *vp, int *namelen)
2306 {
2307 	int error;
2308 	register_t retval[2];
2309 
2310 	error = VOP_PATHCONF(vp, _PC_NAME_MAX, retval);
2311 	if (error)
2312 		return (error);
2313 	*namelen = (int)retval[0];
2314 	return (0);
2315 }
2316 
2317 int
2318 vop_write_dirent(int *error, struct uio *uio, ino_t d_ino, uint8_t d_type,
2319 		uint16_t d_namlen, const char *d_name)
2320 {
2321 	struct dirent *dp;
2322 	size_t len;
2323 
2324 	len = _DIRENT_RECLEN(d_namlen);
2325 	if (len > uio->uio_resid)
2326 		return(1);
2327 
2328 	dp = kmalloc(len, M_TEMP, M_WAITOK | M_ZERO);
2329 
2330 	dp->d_ino = d_ino;
2331 	dp->d_namlen = d_namlen;
2332 	dp->d_type = d_type;
2333 	bcopy(d_name, dp->d_name, d_namlen);
2334 
2335 	*error = uiomove((caddr_t)dp, len, uio);
2336 
2337 	kfree(dp, M_TEMP);
2338 
2339 	return(0);
2340 }
2341 
2342 void
2343 vn_mark_atime(struct vnode *vp, struct thread *td)
2344 {
2345 	struct proc *p = td->td_proc;
2346 	struct ucred *cred = p ? p->p_ucred : proc0.p_ucred;
2347 
2348 	if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) {
2349 		VOP_MARKATIME(vp, cred);
2350 	}
2351 }
2352