xref: /dragonfly/sys/kern/vfs_subr.c (revision ad9f8794)
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.
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 = 22 * (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 
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 		}
320   	}
321 	info.slptimeo = slptimeo;
322 	info.lkflags = LK_EXCLUSIVE | LK_SLEEPFAIL;
323 	if (slpflag & PCATCH)
324 		info.lkflags |= LK_PCATCH;
325 	info.flags = flags;
326 	info.vp = vp;
327 
328 	/*
329 	 * Flush the buffer cache until nothing is left.
330 	 */
331 	while (!RB_EMPTY(&vp->v_rbclean_tree) ||
332 	       !RB_EMPTY(&vp->v_rbdirty_tree)) {
333 		info.clean = 1;
334 		error = RB_SCAN(buf_rb_tree, &vp->v_rbclean_tree, NULL,
335 				vinvalbuf_bp, &info);
336 		if (error == 0) {
337 			info.clean = 0;
338 			error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
339 					vinvalbuf_bp, &info);
340 		}
341 	}
342 
343 	/*
344 	 * Wait for I/O completion.  We may block in the pip code so we have
345 	 * to re-check.
346 	 */
347 	do {
348 		bio_track_wait(&vp->v_track_write, 0, 0);
349 		if ((object = vp->v_object) != NULL) {
350 			refcount_wait(&object->paging_in_progress, "vnvlbx");
351 		}
352 	} while (bio_track_active(&vp->v_track_write));
353 
354 	/*
355 	 * Destroy the copy in the VM cache, too.
356 	 */
357 	if ((object = vp->v_object) != NULL) {
358 		vm_object_page_remove(object, 0, 0,
359 			(flags & V_SAVE) ? TRUE : FALSE);
360 	}
361 
362 	if (!RB_EMPTY(&vp->v_rbdirty_tree) || !RB_EMPTY(&vp->v_rbclean_tree))
363 		panic("vinvalbuf: flush failed");
364 	if (!RB_EMPTY(&vp->v_rbhash_tree))
365 		panic("vinvalbuf: flush failed, buffers still present");
366 	error = 0;
367 done:
368 	lwkt_reltoken(&vp->v_token);
369 	return (error);
370 }
371 
372 static int
373 vinvalbuf_bp(struct buf *bp, void *data)
374 {
375 	struct vinvalbuf_bp_info *info = data;
376 	int error;
377 
378 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
379 		atomic_add_int(&bp->b_refs, 1);
380 		error = BUF_TIMELOCK(bp, info->lkflags,
381 				     "vinvalbuf", info->slptimeo);
382 		atomic_subtract_int(&bp->b_refs, 1);
383 		if (error == 0) {
384 			BUF_UNLOCK(bp);
385 			error = ENOLCK;
386 		}
387 		if (error == ENOLCK)
388 			return(0);
389 		return (-error);
390 	}
391 	KKASSERT(bp->b_vp == info->vp);
392 
393 	/*
394 	 * Must check clean/dirty status after successfully locking as
395 	 * it may race.
396 	 */
397 	if ((info->clean && (bp->b_flags & B_DELWRI)) ||
398 	    (info->clean == 0 && (bp->b_flags & B_DELWRI) == 0)) {
399 		BUF_UNLOCK(bp);
400 		return(0);
401 	}
402 
403 	/*
404 	 * Note that vfs_bio_awrite expects buffers to reside
405 	 * on a queue, while bwrite() and brelse() do not.
406 	 *
407 	 * NOTE:  NO B_LOCKED CHECK.  Also no buf_checkwrite()
408 	 * check.  This code will write out the buffer, period.
409 	 */
410 	if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
411 	    (info->flags & V_SAVE)) {
412 		if (bp->b_flags & B_CLUSTEROK) {
413 			vfs_bio_awrite(bp);
414 		} else {
415 			bremfree(bp);
416 			bawrite(bp);
417 		}
418 	} else if (info->flags & V_SAVE) {
419 		/*
420 		 * Cannot set B_NOCACHE on a clean buffer as this will
421 		 * destroy the VM backing store which might actually
422 		 * be dirty (and unsynchronized).
423 		 */
424 		bremfree(bp);
425 		bp->b_flags |= (B_INVAL | B_RELBUF);
426 		brelse(bp);
427 	} else {
428 		bremfree(bp);
429 		bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF);
430 		brelse(bp);
431 	}
432 	return(0);
433 }
434 
435 /*
436  * Truncate a file's buffer and pages to a specified length.  This
437  * is in lieu of the old vinvalbuf mechanism, which performed unneeded
438  * sync activity.
439  *
440  * The vnode must be locked.
441  */
442 static int vtruncbuf_bp_trunc_cmp(struct buf *bp, void *data);
443 static int vtruncbuf_bp_trunc(struct buf *bp, void *data);
444 static int vtruncbuf_bp_metasync_cmp(struct buf *bp, void *data);
445 static int vtruncbuf_bp_metasync(struct buf *bp, void *data);
446 
447 struct vtruncbuf_info {
448 	struct vnode *vp;
449 	off_t	truncloffset;
450 	int	clean;
451 };
452 
453 int
454 vtruncbuf(struct vnode *vp, off_t length, int blksize)
455 {
456 	struct vtruncbuf_info info;
457 	const char *filename;
458 	int count;
459 
460 	/*
461 	 * Round up to the *next* block, then destroy the buffers in question.
462 	 * Since we are only removing some of the buffers we must rely on the
463 	 * scan count to determine whether a loop is necessary.
464 	 */
465 	if ((count = (int)(length % blksize)) != 0)
466 		info.truncloffset = length + (blksize - count);
467 	else
468 		info.truncloffset = length;
469 	info.vp = vp;
470 
471 	lwkt_gettoken(&vp->v_token);
472 	do {
473 		info.clean = 1;
474 		count = RB_SCAN(buf_rb_tree, &vp->v_rbclean_tree,
475 				vtruncbuf_bp_trunc_cmp,
476 				vtruncbuf_bp_trunc, &info);
477 		info.clean = 0;
478 		count += RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
479 				vtruncbuf_bp_trunc_cmp,
480 				vtruncbuf_bp_trunc, &info);
481 	} while(count);
482 
483 	/*
484 	 * For safety, fsync any remaining metadata if the file is not being
485 	 * truncated to 0.  Since the metadata does not represent the entire
486 	 * dirty list we have to rely on the hit count to ensure that we get
487 	 * all of it.
488 	 */
489 	if (length > 0) {
490 		do {
491 			count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
492 					vtruncbuf_bp_metasync_cmp,
493 					vtruncbuf_bp_metasync, &info);
494 		} while (count);
495 	}
496 
497 	/*
498 	 * Clean out any left over VM backing store.
499 	 *
500 	 * It is possible to have in-progress I/O from buffers that were
501 	 * not part of the truncation.  This should not happen if we
502 	 * are truncating to 0-length.
503 	 */
504 	vnode_pager_setsize(vp, length);
505 	bio_track_wait(&vp->v_track_write, 0, 0);
506 
507 	/*
508 	 * Debugging only
509 	 */
510 	spin_lock(&vp->v_spinlock);
511 	filename = TAILQ_FIRST(&vp->v_namecache) ?
512 		   TAILQ_FIRST(&vp->v_namecache)->nc_name : "?";
513 	spin_unlock(&vp->v_spinlock);
514 
515 	/*
516 	 * Make sure no buffers were instantiated while we were trying
517 	 * to clean out the remaining VM pages.  This could occur due
518 	 * to busy dirty VM pages being flushed out to disk.
519 	 */
520 	do {
521 		info.clean = 1;
522 		count = RB_SCAN(buf_rb_tree, &vp->v_rbclean_tree,
523 				vtruncbuf_bp_trunc_cmp,
524 				vtruncbuf_bp_trunc, &info);
525 		info.clean = 0;
526 		count += RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
527 				vtruncbuf_bp_trunc_cmp,
528 				vtruncbuf_bp_trunc, &info);
529 		if (count) {
530 			kprintf("Warning: vtruncbuf():  Had to re-clean %d "
531 			       "left over buffers in %s\n", count, filename);
532 		}
533 	} while(count);
534 
535 	lwkt_reltoken(&vp->v_token);
536 
537 	return (0);
538 }
539 
540 /*
541  * The callback buffer is beyond the new file EOF and must be destroyed.
542  * Note that the compare function must conform to the RB_SCAN's requirements.
543  */
544 static
545 int
546 vtruncbuf_bp_trunc_cmp(struct buf *bp, void *data)
547 {
548 	struct vtruncbuf_info *info = data;
549 
550 	if (bp->b_loffset >= info->truncloffset)
551 		return(0);
552 	return(-1);
553 }
554 
555 static
556 int
557 vtruncbuf_bp_trunc(struct buf *bp, void *data)
558 {
559 	struct vtruncbuf_info *info = data;
560 
561 	/*
562 	 * Do not try to use a buffer we cannot immediately lock, but sleep
563 	 * anyway to prevent a livelock.  The code will loop until all buffers
564 	 * can be acted upon.
565 	 *
566 	 * We must always revalidate the buffer after locking it to deal
567 	 * with MP races.
568 	 */
569 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
570 		atomic_add_int(&bp->b_refs, 1);
571 		if (BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL) == 0)
572 			BUF_UNLOCK(bp);
573 		atomic_subtract_int(&bp->b_refs, 1);
574 	} else if ((info->clean && (bp->b_flags & B_DELWRI)) ||
575 		   (info->clean == 0 && (bp->b_flags & B_DELWRI) == 0) ||
576 		   bp->b_vp != info->vp ||
577 		   vtruncbuf_bp_trunc_cmp(bp, data)) {
578 		BUF_UNLOCK(bp);
579 	} else {
580 		bremfree(bp);
581 		bp->b_flags |= (B_INVAL | B_RELBUF | B_NOCACHE);
582 		brelse(bp);
583 	}
584 	return(1);
585 }
586 
587 /*
588  * Fsync all meta-data after truncating a file to be non-zero.  Only metadata
589  * blocks (with a negative loffset) are scanned.
590  * Note that the compare function must conform to the RB_SCAN's requirements.
591  */
592 static int
593 vtruncbuf_bp_metasync_cmp(struct buf *bp, void *data __unused)
594 {
595 	if (bp->b_loffset < 0)
596 		return(0);
597 	return(1);
598 }
599 
600 static int
601 vtruncbuf_bp_metasync(struct buf *bp, void *data)
602 {
603 	struct vtruncbuf_info *info = data;
604 
605 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
606 		atomic_add_int(&bp->b_refs, 1);
607 		if (BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL) == 0)
608 			BUF_UNLOCK(bp);
609 		atomic_subtract_int(&bp->b_refs, 1);
610 	} else if ((bp->b_flags & B_DELWRI) == 0 ||
611 		   bp->b_vp != info->vp ||
612 		   vtruncbuf_bp_metasync_cmp(bp, data)) {
613 		BUF_UNLOCK(bp);
614 	} else {
615 		bremfree(bp);
616 		if (bp->b_vp == info->vp)
617 			bawrite(bp);
618 		else
619 			bwrite(bp);
620 	}
621 	return(1);
622 }
623 
624 /*
625  * vfsync - implements a multipass fsync on a file which understands
626  * dependancies and meta-data.  The passed vnode must be locked.  The
627  * waitfor argument may be MNT_WAIT or MNT_NOWAIT, or MNT_LAZY.
628  *
629  * When fsyncing data asynchronously just do one consolidated pass starting
630  * with the most negative block number.  This may not get all the data due
631  * to dependancies.
632  *
633  * When fsyncing data synchronously do a data pass, then a metadata pass,
634  * then do additional data+metadata passes to try to get all the data out.
635  */
636 static int vfsync_wait_output(struct vnode *vp,
637 			    int (*waitoutput)(struct vnode *, struct thread *));
638 static int vfsync_dummy_cmp(struct buf *bp __unused, void *data __unused);
639 static int vfsync_data_only_cmp(struct buf *bp, void *data);
640 static int vfsync_meta_only_cmp(struct buf *bp, void *data);
641 static int vfsync_lazy_range_cmp(struct buf *bp, void *data);
642 static int vfsync_bp(struct buf *bp, void *data);
643 
644 struct vfsync_info {
645 	struct vnode *vp;
646 	int synchronous;
647 	int syncdeps;
648 	int lazycount;
649 	int lazylimit;
650 	int skippedbufs;
651 	int (*checkdef)(struct buf *);
652 	int (*cmpfunc)(struct buf *, void *);
653 };
654 
655 int
656 vfsync(struct vnode *vp, int waitfor, int passes,
657 	int (*checkdef)(struct buf *),
658 	int (*waitoutput)(struct vnode *, struct thread *))
659 {
660 	struct vfsync_info info;
661 	int error;
662 
663 	bzero(&info, sizeof(info));
664 	info.vp = vp;
665 	if ((info.checkdef = checkdef) == NULL)
666 		info.syncdeps = 1;
667 
668 	lwkt_gettoken(&vp->v_token);
669 
670 	switch(waitfor) {
671 	case MNT_LAZY | MNT_NOWAIT:
672 	case MNT_LAZY:
673 		/*
674 		 * Lazy (filesystem syncer typ) Asynchronous plus limit the
675 		 * number of data (not meta) pages we try to flush to 1MB.
676 		 * A non-zero return means that lazy limit was reached.
677 		 */
678 		info.lazylimit = 1024 * 1024;
679 		info.syncdeps = 1;
680 		info.cmpfunc = vfsync_lazy_range_cmp;
681 		error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
682 				vfsync_lazy_range_cmp, vfsync_bp, &info);
683 		info.cmpfunc = vfsync_meta_only_cmp;
684 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
685 			vfsync_meta_only_cmp, vfsync_bp, &info);
686 		if (error == 0)
687 			vp->v_lazyw = 0;
688 		else if (!RB_EMPTY(&vp->v_rbdirty_tree))
689 			vn_syncer_add(vp, 1);
690 		error = 0;
691 		break;
692 	case MNT_NOWAIT:
693 		/*
694 		 * Asynchronous.  Do a data-only pass and a meta-only pass.
695 		 */
696 		info.syncdeps = 1;
697 		info.cmpfunc = vfsync_data_only_cmp;
698 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, vfsync_data_only_cmp,
699 			vfsync_bp, &info);
700 		info.cmpfunc = vfsync_meta_only_cmp;
701 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, vfsync_meta_only_cmp,
702 			vfsync_bp, &info);
703 		error = 0;
704 		break;
705 	default:
706 		/*
707 		 * Synchronous.  Do a data-only pass, then a meta-data+data
708 		 * pass, then additional integrated passes to try to get
709 		 * all the dependancies flushed.
710 		 */
711 		info.cmpfunc = vfsync_data_only_cmp;
712 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, vfsync_data_only_cmp,
713 			vfsync_bp, &info);
714 		error = vfsync_wait_output(vp, waitoutput);
715 		if (error == 0) {
716 			info.skippedbufs = 0;
717 			info.cmpfunc = vfsync_dummy_cmp;
718 			RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
719 				vfsync_bp, &info);
720 			error = vfsync_wait_output(vp, waitoutput);
721 			if (info.skippedbufs) {
722 				kprintf("Warning: vfsync skipped %d dirty "
723 					"bufs in pass2!\n", info.skippedbufs);
724 			}
725 		}
726 		while (error == 0 && passes > 0 &&
727 		       !RB_EMPTY(&vp->v_rbdirty_tree)
728 		) {
729 			if (--passes == 0) {
730 				info.synchronous = 1;
731 				info.syncdeps = 1;
732 			}
733 			info.cmpfunc = vfsync_dummy_cmp;
734 			error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
735 					vfsync_bp, &info);
736 			if (error < 0)
737 				error = -error;
738 			info.syncdeps = 1;
739 			if (error == 0)
740 				error = vfsync_wait_output(vp, waitoutput);
741 		}
742 		break;
743 	}
744 	lwkt_reltoken(&vp->v_token);
745 	return(error);
746 }
747 
748 static int
749 vfsync_wait_output(struct vnode *vp,
750 		   int (*waitoutput)(struct vnode *, struct thread *))
751 {
752 	int error;
753 
754 	error = bio_track_wait(&vp->v_track_write, 0, 0);
755 	if (waitoutput)
756 		error = waitoutput(vp, curthread);
757 	return(error);
758 }
759 
760 static int
761 vfsync_dummy_cmp(struct buf *bp __unused, void *data __unused)
762 {
763 	return(0);
764 }
765 
766 static int
767 vfsync_data_only_cmp(struct buf *bp, void *data)
768 {
769 	if (bp->b_loffset < 0)
770 		return(-1);
771 	return(0);
772 }
773 
774 static int
775 vfsync_meta_only_cmp(struct buf *bp, void *data)
776 {
777 	if (bp->b_loffset < 0)
778 		return(0);
779 	return(1);
780 }
781 
782 static int
783 vfsync_lazy_range_cmp(struct buf *bp, void *data)
784 {
785 	struct vfsync_info *info = data;
786 
787 	if (bp->b_loffset < info->vp->v_lazyw)
788 		return(-1);
789 	return(0);
790 }
791 
792 static int
793 vfsync_bp(struct buf *bp, void *data)
794 {
795 	struct vfsync_info *info = data;
796 	struct vnode *vp = info->vp;
797 	int error;
798 
799 	/*
800 	 * Ignore buffers that we cannot immediately lock.
801 	 */
802 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
803 		++info->skippedbufs;
804 		return(0);
805 	}
806 
807 	/*
808 	 * We must revalidate the buffer after locking.
809 	 */
810 	if ((bp->b_flags & B_DELWRI) == 0 ||
811 	    bp->b_vp != info->vp ||
812 	    info->cmpfunc(bp, data)) {
813 		BUF_UNLOCK(bp);
814 		return(0);
815 	}
816 
817 	/*
818 	 * If syncdeps is not set we do not try to write buffers which have
819 	 * dependancies.
820 	 */
821 	if (!info->synchronous && info->syncdeps == 0 && info->checkdef(bp)) {
822 		BUF_UNLOCK(bp);
823 		return(0);
824 	}
825 
826 	/*
827 	 * B_NEEDCOMMIT (primarily used by NFS) is a state where the buffer
828 	 * has been written but an additional handshake with the device
829 	 * is required before we can dispose of the buffer.  We have no idea
830 	 * how to do this so we have to skip these buffers.
831 	 */
832 	if (bp->b_flags & B_NEEDCOMMIT) {
833 		BUF_UNLOCK(bp);
834 		return(0);
835 	}
836 
837 	/*
838 	 * Ask bioops if it is ok to sync.  If not the VFS may have
839 	 * set B_LOCKED so we have to cycle the buffer.
840 	 */
841 	if (LIST_FIRST(&bp->b_dep) != NULL && buf_checkwrite(bp)) {
842 		bremfree(bp);
843 		brelse(bp);
844 		return(0);
845 	}
846 
847 	if (info->synchronous) {
848 		/*
849 		 * Synchronous flushing.  An error may be returned.
850 		 */
851 		bremfree(bp);
852 		error = bwrite(bp);
853 	} else {
854 		/*
855 		 * Asynchronous flushing.  A negative return value simply
856 		 * stops the scan and is not considered an error.  We use
857 		 * this to support limited MNT_LAZY flushes.
858 		 */
859 		vp->v_lazyw = bp->b_loffset;
860 		if ((vp->v_flag & VOBJBUF) && (bp->b_flags & B_CLUSTEROK)) {
861 			info->lazycount += vfs_bio_awrite(bp);
862 		} else {
863 			info->lazycount += bp->b_bufsize;
864 			bremfree(bp);
865 			bawrite(bp);
866 		}
867 		waitrunningbufspace();
868 		if (info->lazylimit && info->lazycount >= info->lazylimit)
869 			error = 1;
870 		else
871 			error = 0;
872 	}
873 	return(-error);
874 }
875 
876 /*
877  * Associate a buffer with a vnode.
878  *
879  * MPSAFE
880  */
881 int
882 bgetvp(struct vnode *vp, struct buf *bp, int testsize)
883 {
884 	KASSERT(bp->b_vp == NULL, ("bgetvp: not free"));
885 	KKASSERT((bp->b_flags & (B_HASHED|B_DELWRI|B_VNCLEAN|B_VNDIRTY)) == 0);
886 
887 	/*
888 	 * Insert onto list for new vnode.
889 	 */
890 	lwkt_gettoken(&vp->v_token);
891 
892 	if (buf_rb_hash_RB_INSERT(&vp->v_rbhash_tree, bp)) {
893 		lwkt_reltoken(&vp->v_token);
894 		return (EEXIST);
895 	}
896 
897 	/*
898 	 * Diagnostics (mainly for HAMMER debugging).  Check for
899 	 * overlapping buffers.
900 	 */
901 	if (check_buf_overlap) {
902 		struct buf *bx;
903 		bx = buf_rb_hash_RB_PREV(bp);
904 		if (bx) {
905 			if (bx->b_loffset + bx->b_bufsize > bp->b_loffset) {
906 				kprintf("bgetvp: overlapl %016jx/%d %016jx "
907 					"bx %p bp %p\n",
908 					(intmax_t)bx->b_loffset,
909 					bx->b_bufsize,
910 					(intmax_t)bp->b_loffset,
911 					bx, bp);
912 				if (check_buf_overlap > 1)
913 					panic("bgetvp - overlapping buffer");
914 			}
915 		}
916 		bx = buf_rb_hash_RB_NEXT(bp);
917 		if (bx) {
918 			if (bp->b_loffset + testsize > bx->b_loffset) {
919 				kprintf("bgetvp: overlapr %016jx/%d %016jx "
920 					"bp %p bx %p\n",
921 					(intmax_t)bp->b_loffset,
922 					testsize,
923 					(intmax_t)bx->b_loffset,
924 					bp, bx);
925 				if (check_buf_overlap > 1)
926 					panic("bgetvp - overlapping buffer");
927 			}
928 		}
929 	}
930 	bp->b_vp = vp;
931 	bp->b_flags |= B_HASHED;
932 	bp->b_flags |= B_VNCLEAN;
933 	if (buf_rb_tree_RB_INSERT(&vp->v_rbclean_tree, bp))
934 		panic("reassignbuf: dup lblk/clean vp %p bp %p", vp, bp);
935 	vhold(vp);
936 	lwkt_reltoken(&vp->v_token);
937 	return(0);
938 }
939 
940 /*
941  * Disassociate a buffer from a vnode.
942  *
943  * MPSAFE
944  */
945 void
946 brelvp(struct buf *bp)
947 {
948 	struct vnode *vp;
949 
950 	KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
951 
952 	/*
953 	 * Delete from old vnode list, if on one.
954 	 */
955 	vp = bp->b_vp;
956 	lwkt_gettoken(&vp->v_token);
957 	if (bp->b_flags & (B_VNDIRTY | B_VNCLEAN)) {
958 		if (bp->b_flags & B_VNDIRTY)
959 			buf_rb_tree_RB_REMOVE(&vp->v_rbdirty_tree, bp);
960 		else
961 			buf_rb_tree_RB_REMOVE(&vp->v_rbclean_tree, bp);
962 		bp->b_flags &= ~(B_VNDIRTY | B_VNCLEAN);
963 	}
964 	if (bp->b_flags & B_HASHED) {
965 		buf_rb_hash_RB_REMOVE(&vp->v_rbhash_tree, bp);
966 		bp->b_flags &= ~B_HASHED;
967 	}
968 	if ((vp->v_flag & VONWORKLST) && RB_EMPTY(&vp->v_rbdirty_tree))
969 		vn_syncer_remove(vp);
970 	bp->b_vp = NULL;
971 
972 	lwkt_reltoken(&vp->v_token);
973 
974 	vdrop(vp);
975 }
976 
977 /*
978  * Reassign the buffer to the proper clean/dirty list based on B_DELWRI.
979  * This routine is called when the state of the B_DELWRI bit is changed.
980  *
981  * Must be called with vp->v_token held.
982  * MPSAFE
983  */
984 void
985 reassignbuf(struct buf *bp)
986 {
987 	struct vnode *vp = bp->b_vp;
988 	int delay;
989 
990 	ASSERT_LWKT_TOKEN_HELD(&vp->v_token);
991 	++reassignbufcalls;
992 
993 	/*
994 	 * B_PAGING flagged buffers cannot be reassigned because their vp
995 	 * is not fully linked in.
996 	 */
997 	if (bp->b_flags & B_PAGING)
998 		panic("cannot reassign paging buffer");
999 
1000 	if (bp->b_flags & B_DELWRI) {
1001 		/*
1002 		 * Move to the dirty list, add the vnode to the worklist
1003 		 */
1004 		if (bp->b_flags & B_VNCLEAN) {
1005 			buf_rb_tree_RB_REMOVE(&vp->v_rbclean_tree, bp);
1006 			bp->b_flags &= ~B_VNCLEAN;
1007 		}
1008 		if ((bp->b_flags & B_VNDIRTY) == 0) {
1009 			if (buf_rb_tree_RB_INSERT(&vp->v_rbdirty_tree, bp)) {
1010 				panic("reassignbuf: dup lblk vp %p bp %p",
1011 				      vp, bp);
1012 			}
1013 			bp->b_flags |= B_VNDIRTY;
1014 		}
1015 		if ((vp->v_flag & VONWORKLST) == 0) {
1016 			switch (vp->v_type) {
1017 			case VDIR:
1018 				delay = dirdelay;
1019 				break;
1020 			case VCHR:
1021 			case VBLK:
1022 				if (vp->v_rdev &&
1023 				    vp->v_rdev->si_mountpoint != NULL) {
1024 					delay = metadelay;
1025 					break;
1026 				}
1027 				/* fall through */
1028 			default:
1029 				delay = filedelay;
1030 			}
1031 			vn_syncer_add(vp, delay);
1032 		}
1033 	} else {
1034 		/*
1035 		 * Move to the clean list, remove the vnode from the worklist
1036 		 * if no dirty blocks remain.
1037 		 */
1038 		if (bp->b_flags & B_VNDIRTY) {
1039 			buf_rb_tree_RB_REMOVE(&vp->v_rbdirty_tree, bp);
1040 			bp->b_flags &= ~B_VNDIRTY;
1041 		}
1042 		if ((bp->b_flags & B_VNCLEAN) == 0) {
1043 			if (buf_rb_tree_RB_INSERT(&vp->v_rbclean_tree, bp)) {
1044 				panic("reassignbuf: dup lblk vp %p bp %p",
1045 				      vp, bp);
1046 			}
1047 			bp->b_flags |= B_VNCLEAN;
1048 		}
1049 		if ((vp->v_flag & VONWORKLST) &&
1050 		    RB_EMPTY(&vp->v_rbdirty_tree)) {
1051 			vn_syncer_remove(vp);
1052 		}
1053 	}
1054 }
1055 
1056 /*
1057  * Create a vnode for a block device.  Used for mounting the root file
1058  * system.
1059  *
1060  * A vref()'d vnode is returned.
1061  */
1062 extern struct vop_ops *devfs_vnode_dev_vops_p;
1063 int
1064 bdevvp(cdev_t dev, struct vnode **vpp)
1065 {
1066 	struct vnode *vp;
1067 	struct vnode *nvp;
1068 	int error;
1069 
1070 	if (dev == NULL) {
1071 		*vpp = NULLVP;
1072 		return (ENXIO);
1073 	}
1074 	error = getspecialvnode(VT_NON, NULL, &devfs_vnode_dev_vops_p,
1075 				&nvp, 0, 0);
1076 	if (error) {
1077 		*vpp = NULLVP;
1078 		return (error);
1079 	}
1080 	vp = nvp;
1081 	vp->v_type = VCHR;
1082 #if 0
1083 	vp->v_rdev = dev;
1084 #endif
1085 	v_associate_rdev(vp, dev);
1086 	vp->v_umajor = dev->si_umajor;
1087 	vp->v_uminor = dev->si_uminor;
1088 	vx_unlock(vp);
1089 	*vpp = vp;
1090 	return (0);
1091 }
1092 
1093 int
1094 v_associate_rdev(struct vnode *vp, cdev_t dev)
1095 {
1096 	if (dev == NULL)
1097 		return(ENXIO);
1098 	if (dev_is_good(dev) == 0)
1099 		return(ENXIO);
1100 	KKASSERT(vp->v_rdev == NULL);
1101 	vp->v_rdev = reference_dev(dev);
1102 	lwkt_gettoken(&spechash_token);
1103 	SLIST_INSERT_HEAD(&dev->si_hlist, vp, v_cdevnext);
1104 	lwkt_reltoken(&spechash_token);
1105 	return(0);
1106 }
1107 
1108 void
1109 v_release_rdev(struct vnode *vp)
1110 {
1111 	cdev_t dev;
1112 
1113 	if ((dev = vp->v_rdev) != NULL) {
1114 		lwkt_gettoken(&spechash_token);
1115 		SLIST_REMOVE(&dev->si_hlist, vp, vnode, v_cdevnext);
1116 		vp->v_rdev = NULL;
1117 		release_dev(dev);
1118 		lwkt_reltoken(&spechash_token);
1119 	}
1120 }
1121 
1122 /*
1123  * Add a vnode to the alias list hung off the cdev_t.  We only associate
1124  * the device number with the vnode.  The actual device is not associated
1125  * until the vnode is opened (usually in spec_open()), and will be
1126  * disassociated on last close.
1127  */
1128 void
1129 addaliasu(struct vnode *nvp, int x, int y)
1130 {
1131 	if (nvp->v_type != VBLK && nvp->v_type != VCHR)
1132 		panic("addaliasu on non-special vnode");
1133 	nvp->v_umajor = x;
1134 	nvp->v_uminor = y;
1135 }
1136 
1137 /*
1138  * Simple call that a filesystem can make to try to get rid of a
1139  * vnode.  It will fail if anyone is referencing the vnode (including
1140  * the caller).
1141  *
1142  * The filesystem can check whether its in-memory inode structure still
1143  * references the vp on return.
1144  */
1145 void
1146 vclean_unlocked(struct vnode *vp)
1147 {
1148 	vx_get(vp);
1149 	if (sysref_isactive(&vp->v_sysref) == 0)
1150 		vgone_vxlocked(vp);
1151 	vx_put(vp);
1152 }
1153 
1154 /*
1155  * Disassociate a vnode from its underlying filesystem.
1156  *
1157  * The vnode must be VX locked and referenced.  In all normal situations
1158  * there are no active references.  If vclean_vxlocked() is called while
1159  * there are active references, the vnode is being ripped out and we have
1160  * to call VOP_CLOSE() as appropriate before we can reclaim it.
1161  */
1162 void
1163 vclean_vxlocked(struct vnode *vp, int flags)
1164 {
1165 	int active;
1166 	int n;
1167 	vm_object_t object;
1168 	struct namecache *ncp;
1169 
1170 	/*
1171 	 * If the vnode has already been reclaimed we have nothing to do.
1172 	 */
1173 	if (vp->v_flag & VRECLAIMED)
1174 		return;
1175 	vsetflags(vp, VRECLAIMED);
1176 
1177 	if (verbose_reclaims) {
1178 		if ((ncp = TAILQ_FIRST(&vp->v_namecache)) != NULL)
1179 			kprintf("Debug: reclaim %p %s\n", vp, ncp->nc_name);
1180 	}
1181 
1182 	/*
1183 	 * Scrap the vfs cache
1184 	 */
1185 	while (cache_inval_vp(vp, 0) != 0) {
1186 		kprintf("Warning: vnode %p clean/cache_resolution "
1187 			"race detected\n", vp);
1188 		tsleep(vp, 0, "vclninv", 2);
1189 	}
1190 
1191 	/*
1192 	 * Check to see if the vnode is in use. If so we have to reference it
1193 	 * before we clean it out so that its count cannot fall to zero and
1194 	 * generate a race against ourselves to recycle it.
1195 	 */
1196 	active = sysref_isactive(&vp->v_sysref);
1197 
1198 	/*
1199 	 * Clean out any buffers associated with the vnode and destroy its
1200 	 * object, if it has one.
1201 	 */
1202 	vinvalbuf(vp, V_SAVE, 0, 0);
1203 
1204 	/*
1205 	 * If purging an active vnode (typically during a forced unmount
1206 	 * or reboot), it must be closed and deactivated before being
1207 	 * reclaimed.  This isn't really all that safe, but what can
1208 	 * we do? XXX.
1209 	 *
1210 	 * Note that neither of these routines unlocks the vnode.
1211 	 */
1212 	if (active && (flags & DOCLOSE)) {
1213 		while ((n = vp->v_opencount) != 0) {
1214 			if (vp->v_writecount)
1215 				VOP_CLOSE(vp, FWRITE|FNONBLOCK);
1216 			else
1217 				VOP_CLOSE(vp, FNONBLOCK);
1218 			if (vp->v_opencount == n) {
1219 				kprintf("Warning: unable to force-close"
1220 				       " vnode %p\n", vp);
1221 				break;
1222 			}
1223 		}
1224 	}
1225 
1226 	/*
1227 	 * If the vnode has not been deactivated, deactivated it.  Deactivation
1228 	 * can create new buffers and VM pages so we have to call vinvalbuf()
1229 	 * again to make sure they all get flushed.
1230 	 *
1231 	 * This can occur if a file with a link count of 0 needs to be
1232 	 * truncated.
1233 	 *
1234 	 * If the vnode is already dead don't try to deactivate it.
1235 	 */
1236 	if ((vp->v_flag & VINACTIVE) == 0) {
1237 		vsetflags(vp, VINACTIVE);
1238 		if (vp->v_mount)
1239 			VOP_INACTIVE(vp);
1240 		vinvalbuf(vp, V_SAVE, 0, 0);
1241 	}
1242 
1243 	/*
1244 	 * If the vnode has an object, destroy it.
1245 	 */
1246 	lwkt_gettoken(&vmobj_token);
1247 	object = vp->v_object;
1248 	if (object != NULL) {
1249 		/*
1250 		 * Use vm_object_lock() rather than vm_object_hold to avoid
1251 		 * creating an extra (self-)hold on the object.
1252 		 *
1253 		 * NOTE: vm_object_terminate() eats the object lock.
1254 		 */
1255 		vm_object_lock(object);
1256 		KKASSERT(object == vp->v_object);
1257 		if (object->ref_count == 0) {
1258 			if ((object->flags & OBJ_DEAD) == 0) {
1259 				/* eats object lock */
1260 				vm_object_terminate(object);
1261 			} else {
1262 				vm_object_unlock(object);
1263 			}
1264 			vclrflags(vp, VOBJBUF);
1265 		} else {
1266 			vm_pager_deallocate(object);
1267 			vclrflags(vp, VOBJBUF);
1268 			vm_object_unlock(object);
1269 		}
1270 	}
1271 	lwkt_reltoken(&vmobj_token);
1272 	KKASSERT((vp->v_flag & VOBJBUF) == 0);
1273 
1274 	/*
1275 	 * Reclaim the vnode if not already dead.
1276 	 */
1277 	if (vp->v_mount && VOP_RECLAIM(vp))
1278 		panic("vclean: cannot reclaim");
1279 
1280 	/*
1281 	 * Done with purge, notify sleepers of the grim news.
1282 	 */
1283 	vp->v_ops = &dead_vnode_vops_p;
1284 	vn_gone(vp);
1285 	vp->v_tag = VT_NON;
1286 
1287 	/*
1288 	 * If we are destroying an active vnode, reactivate it now that
1289 	 * we have reassociated it with deadfs.  This prevents the system
1290 	 * from crashing on the vnode due to it being unexpectedly marked
1291 	 * as inactive or reclaimed.
1292 	 */
1293 	if (active && (flags & DOCLOSE)) {
1294 		vclrflags(vp, VINACTIVE | VRECLAIMED);
1295 	}
1296 }
1297 
1298 /*
1299  * Eliminate all activity associated with the requested vnode
1300  * and with all vnodes aliased to the requested vnode.
1301  *
1302  * The vnode must be referenced but should not be locked.
1303  */
1304 int
1305 vrevoke(struct vnode *vp, struct ucred *cred)
1306 {
1307 	struct vnode *vq;
1308 	struct vnode *vqn;
1309 	cdev_t dev;
1310 	int error;
1311 
1312 	/*
1313 	 * If the vnode has a device association, scrap all vnodes associated
1314 	 * with the device.  Don't let the device disappear on us while we
1315 	 * are scrapping the vnodes.
1316 	 *
1317 	 * The passed vp will probably show up in the list, do not VX lock
1318 	 * it twice!
1319 	 *
1320 	 * Releasing the vnode's rdev here can mess up specfs's call to
1321 	 * device close, so don't do it.  The vnode has been disassociated
1322 	 * and the device will be closed after the last ref on the related
1323 	 * fp goes away (if not still open by e.g. the kernel).
1324 	 */
1325 	if (vp->v_type != VCHR) {
1326 		error = fdrevoke(vp, DTYPE_VNODE, cred);
1327 		return (error);
1328 	}
1329 	if ((dev = vp->v_rdev) == NULL) {
1330 		return(0);
1331 	}
1332 	reference_dev(dev);
1333 	lwkt_gettoken(&spechash_token);
1334 
1335 	vqn = SLIST_FIRST(&dev->si_hlist);
1336 	if (vqn)
1337 		vref(vqn);
1338 	while ((vq = vqn) != NULL) {
1339 		vqn = SLIST_NEXT(vqn, v_cdevnext);
1340 		if (vqn)
1341 			vref(vqn);
1342 		fdrevoke(vq, DTYPE_VNODE, cred);
1343 		/*v_release_rdev(vq);*/
1344 		vrele(vq);
1345 	}
1346 	lwkt_reltoken(&spechash_token);
1347 	dev_drevoke(dev);
1348 	release_dev(dev);
1349 	return (0);
1350 }
1351 
1352 /*
1353  * This is called when the object underlying a vnode is being destroyed,
1354  * such as in a remove().  Try to recycle the vnode immediately if the
1355  * only active reference is our reference.
1356  *
1357  * Directory vnodes in the namecache with children cannot be immediately
1358  * recycled because numerous VOP_N*() ops require them to be stable.
1359  *
1360  * To avoid recursive recycling from VOP_INACTIVE implemenetations this
1361  * function is a NOP if VRECLAIMED is already set.
1362  */
1363 int
1364 vrecycle(struct vnode *vp)
1365 {
1366 	if (vp->v_sysref.refcnt <= 1 && (vp->v_flag & VRECLAIMED) == 0) {
1367 		if (cache_inval_vp_nonblock(vp))
1368 			return(0);
1369 		vgone_vxlocked(vp);
1370 		return (1);
1371 	}
1372 	return (0);
1373 }
1374 
1375 /*
1376  * Return the maximum I/O size allowed for strategy calls on VP.
1377  *
1378  * If vp is VCHR or VBLK we dive the device, otherwise we use
1379  * the vp's mount info.
1380  */
1381 int
1382 vmaxiosize(struct vnode *vp)
1383 {
1384 	if (vp->v_type == VBLK || vp->v_type == VCHR) {
1385 		return(vp->v_rdev->si_iosize_max);
1386 	} else {
1387 		return(vp->v_mount->mnt_iosize_max);
1388 	}
1389 }
1390 
1391 /*
1392  * Eliminate all activity associated with a vnode in preparation for reuse.
1393  *
1394  * The vnode must be VX locked and refd and will remain VX locked and refd
1395  * on return.  This routine may be called with the vnode in any state, as
1396  * long as it is VX locked.  The vnode will be cleaned out and marked
1397  * VRECLAIMED but will not actually be reused until all existing refs and
1398  * holds go away.
1399  *
1400  * NOTE: This routine may be called on a vnode which has not yet been
1401  * already been deactivated (VOP_INACTIVE), or on a vnode which has
1402  * already been reclaimed.
1403  *
1404  * This routine is not responsible for placing us back on the freelist.
1405  * Instead, it happens automatically when the caller releases the VX lock
1406  * (assuming there aren't any other references).
1407  */
1408 void
1409 vgone_vxlocked(struct vnode *vp)
1410 {
1411 	/*
1412 	 * assert that the VX lock is held.  This is an absolute requirement
1413 	 * now for vgone_vxlocked() to be called.
1414 	 */
1415 	KKASSERT(vp->v_lock.lk_exclusivecount == 1);
1416 
1417 	get_mplock();
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 	rel_mplock();
1448 }
1449 
1450 /*
1451  * Lookup a vnode by device number.
1452  *
1453  * Returns non-zero and *vpp set to a vref'd vnode on success.
1454  * Returns zero on failure.
1455  */
1456 int
1457 vfinddev(cdev_t dev, enum vtype type, struct vnode **vpp)
1458 {
1459 	struct vnode *vp;
1460 
1461 	lwkt_gettoken(&spechash_token);
1462 	SLIST_FOREACH(vp, &dev->si_hlist, v_cdevnext) {
1463 		if (type == vp->v_type) {
1464 			*vpp = vp;
1465 			vref(vp);
1466 			lwkt_reltoken(&spechash_token);
1467 			return (1);
1468 		}
1469 	}
1470 	lwkt_reltoken(&spechash_token);
1471 	return (0);
1472 }
1473 
1474 /*
1475  * Calculate the total number of references to a special device.  This
1476  * routine may only be called for VBLK and VCHR vnodes since v_rdev is
1477  * an overloaded field.  Since udev2dev can now return NULL, we have
1478  * to check for a NULL v_rdev.
1479  */
1480 int
1481 count_dev(cdev_t dev)
1482 {
1483 	struct vnode *vp;
1484 	int count = 0;
1485 
1486 	if (SLIST_FIRST(&dev->si_hlist)) {
1487 		lwkt_gettoken(&spechash_token);
1488 		SLIST_FOREACH(vp, &dev->si_hlist, v_cdevnext) {
1489 			count += vp->v_opencount;
1490 		}
1491 		lwkt_reltoken(&spechash_token);
1492 	}
1493 	return(count);
1494 }
1495 
1496 int
1497 vcount(struct vnode *vp)
1498 {
1499 	if (vp->v_rdev == NULL)
1500 		return(0);
1501 	return(count_dev(vp->v_rdev));
1502 }
1503 
1504 /*
1505  * Initialize VMIO for a vnode.  This routine MUST be called before a
1506  * VFS can issue buffer cache ops on a vnode.  It is typically called
1507  * when a vnode is initialized from its inode.
1508  */
1509 int
1510 vinitvmio(struct vnode *vp, off_t filesize, int blksize, int boff)
1511 {
1512 	vm_object_t object;
1513 	int error = 0;
1514 
1515 	lwkt_gettoken(&vmobj_token);
1516 retry:
1517 	if ((object = vp->v_object) == NULL) {
1518 		object = vnode_pager_alloc(vp, filesize, 0, 0, blksize, boff);
1519 		/*
1520 		 * Dereference the reference we just created.  This assumes
1521 		 * that the object is associated with the vp.
1522 		 */
1523 		object->ref_count--;
1524 		vrele(vp);
1525 	} else {
1526 		if (object->flags & OBJ_DEAD) {
1527 			vn_unlock(vp);
1528 			if (vp->v_object == object)
1529 				vm_object_dead_sleep(object, "vodead");
1530 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1531 			goto retry;
1532 		}
1533 	}
1534 	KASSERT(vp->v_object != NULL, ("vinitvmio: NULL object"));
1535 	vsetflags(vp, VOBJBUF);
1536 	lwkt_reltoken(&vmobj_token);
1537 
1538 	return (error);
1539 }
1540 
1541 
1542 /*
1543  * Print out a description of a vnode.
1544  */
1545 static char *typename[] =
1546 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"};
1547 
1548 void
1549 vprint(char *label, struct vnode *vp)
1550 {
1551 	char buf[96];
1552 
1553 	if (label != NULL)
1554 		kprintf("%s: %p: ", label, (void *)vp);
1555 	else
1556 		kprintf("%p: ", (void *)vp);
1557 	kprintf("type %s, sysrefs %d, writecount %d, holdcnt %d,",
1558 		typename[vp->v_type],
1559 		vp->v_sysref.refcnt, vp->v_writecount, vp->v_auxrefs);
1560 	buf[0] = '\0';
1561 	if (vp->v_flag & VROOT)
1562 		strcat(buf, "|VROOT");
1563 	if (vp->v_flag & VPFSROOT)
1564 		strcat(buf, "|VPFSROOT");
1565 	if (vp->v_flag & VTEXT)
1566 		strcat(buf, "|VTEXT");
1567 	if (vp->v_flag & VSYSTEM)
1568 		strcat(buf, "|VSYSTEM");
1569 	if (vp->v_flag & VFREE)
1570 		strcat(buf, "|VFREE");
1571 	if (vp->v_flag & VOBJBUF)
1572 		strcat(buf, "|VOBJBUF");
1573 	if (buf[0] != '\0')
1574 		kprintf(" flags (%s)", &buf[1]);
1575 	if (vp->v_data == NULL) {
1576 		kprintf("\n");
1577 	} else {
1578 		kprintf("\n\t");
1579 		VOP_PRINT(vp);
1580 	}
1581 }
1582 
1583 /*
1584  * Do the usual access checking.
1585  * file_mode, uid and gid are from the vnode in question,
1586  * while acc_mode and cred are from the VOP_ACCESS parameter list
1587  */
1588 int
1589 vaccess(enum vtype type, mode_t file_mode, uid_t uid, gid_t gid,
1590     mode_t acc_mode, struct ucred *cred)
1591 {
1592 	mode_t mask;
1593 	int ismember;
1594 
1595 	/*
1596 	 * Super-user always gets read/write access, but execute access depends
1597 	 * on at least one execute bit being set.
1598 	 */
1599 	if (priv_check_cred(cred, PRIV_ROOT, 0) == 0) {
1600 		if ((acc_mode & VEXEC) && type != VDIR &&
1601 		    (file_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)
1602 			return (EACCES);
1603 		return (0);
1604 	}
1605 
1606 	mask = 0;
1607 
1608 	/* Otherwise, check the owner. */
1609 	if (cred->cr_uid == uid) {
1610 		if (acc_mode & VEXEC)
1611 			mask |= S_IXUSR;
1612 		if (acc_mode & VREAD)
1613 			mask |= S_IRUSR;
1614 		if (acc_mode & VWRITE)
1615 			mask |= S_IWUSR;
1616 		return ((file_mode & mask) == mask ? 0 : EACCES);
1617 	}
1618 
1619 	/* Otherwise, check the groups. */
1620 	ismember = groupmember(gid, cred);
1621 	if (cred->cr_svgid == gid || ismember) {
1622 		if (acc_mode & VEXEC)
1623 			mask |= S_IXGRP;
1624 		if (acc_mode & VREAD)
1625 			mask |= S_IRGRP;
1626 		if (acc_mode & VWRITE)
1627 			mask |= S_IWGRP;
1628 		return ((file_mode & mask) == mask ? 0 : EACCES);
1629 	}
1630 
1631 	/* Otherwise, check everyone else. */
1632 	if (acc_mode & VEXEC)
1633 		mask |= S_IXOTH;
1634 	if (acc_mode & VREAD)
1635 		mask |= S_IROTH;
1636 	if (acc_mode & VWRITE)
1637 		mask |= S_IWOTH;
1638 	return ((file_mode & mask) == mask ? 0 : EACCES);
1639 }
1640 
1641 #ifdef DDB
1642 #include <ddb/ddb.h>
1643 
1644 static int db_show_locked_vnodes(struct mount *mp, void *data);
1645 
1646 /*
1647  * List all of the locked vnodes in the system.
1648  * Called when debugging the kernel.
1649  */
1650 DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
1651 {
1652 	kprintf("Locked vnodes\n");
1653 	mountlist_scan(db_show_locked_vnodes, NULL,
1654 			MNTSCAN_FORWARD|MNTSCAN_NOBUSY);
1655 }
1656 
1657 static int
1658 db_show_locked_vnodes(struct mount *mp, void *data __unused)
1659 {
1660 	struct vnode *vp;
1661 
1662 	TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
1663 		if (vn_islocked(vp))
1664 			vprint(NULL, vp);
1665 	}
1666 	return(0);
1667 }
1668 #endif
1669 
1670 /*
1671  * Top level filesystem related information gathering.
1672  */
1673 static int	sysctl_ovfs_conf (SYSCTL_HANDLER_ARGS);
1674 
1675 static int
1676 vfs_sysctl(SYSCTL_HANDLER_ARGS)
1677 {
1678 	int *name = (int *)arg1 - 1;	/* XXX */
1679 	u_int namelen = arg2 + 1;	/* XXX */
1680 	struct vfsconf *vfsp;
1681 	int maxtypenum;
1682 
1683 #if 1 || defined(COMPAT_PRELITE2)
1684 	/* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
1685 	if (namelen == 1)
1686 		return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
1687 #endif
1688 
1689 #ifdef notyet
1690 	/* all sysctl names at this level are at least name and field */
1691 	if (namelen < 2)
1692 		return (ENOTDIR);		/* overloaded */
1693 	if (name[0] != VFS_GENERIC) {
1694 		vfsp = vfsconf_find_by_typenum(name[0]);
1695 		if (vfsp == NULL)
1696 			return (EOPNOTSUPP);
1697 		return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1,
1698 		    oldp, oldlenp, newp, newlen, p));
1699 	}
1700 #endif
1701 	switch (name[1]) {
1702 	case VFS_MAXTYPENUM:
1703 		if (namelen != 2)
1704 			return (ENOTDIR);
1705 		maxtypenum = vfsconf_get_maxtypenum();
1706 		return (SYSCTL_OUT(req, &maxtypenum, sizeof(maxtypenum)));
1707 	case VFS_CONF:
1708 		if (namelen != 3)
1709 			return (ENOTDIR);	/* overloaded */
1710 		vfsp = vfsconf_find_by_typenum(name[2]);
1711 		if (vfsp == NULL)
1712 			return (EOPNOTSUPP);
1713 		return (SYSCTL_OUT(req, vfsp, sizeof *vfsp));
1714 	}
1715 	return (EOPNOTSUPP);
1716 }
1717 
1718 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl,
1719 	"Generic filesystem");
1720 
1721 #if 1 || defined(COMPAT_PRELITE2)
1722 
1723 static int
1724 sysctl_ovfs_conf_iter(struct vfsconf *vfsp, void *data)
1725 {
1726 	int error;
1727 	struct ovfsconf ovfs;
1728 	struct sysctl_req *req = (struct sysctl_req*) data;
1729 
1730 	bzero(&ovfs, sizeof(ovfs));
1731 	ovfs.vfc_vfsops = vfsp->vfc_vfsops;	/* XXX used as flag */
1732 	strcpy(ovfs.vfc_name, vfsp->vfc_name);
1733 	ovfs.vfc_index = vfsp->vfc_typenum;
1734 	ovfs.vfc_refcount = vfsp->vfc_refcount;
1735 	ovfs.vfc_flags = vfsp->vfc_flags;
1736 	error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
1737 	if (error)
1738 		return error; /* abort iteration with error code */
1739 	else
1740 		return 0; /* continue iterating with next element */
1741 }
1742 
1743 static int
1744 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
1745 {
1746 	return vfsconf_each(sysctl_ovfs_conf_iter, (void*)req);
1747 }
1748 
1749 #endif /* 1 || COMPAT_PRELITE2 */
1750 
1751 /*
1752  * Check to see if a filesystem is mounted on a block device.
1753  */
1754 int
1755 vfs_mountedon(struct vnode *vp)
1756 {
1757 	cdev_t dev;
1758 
1759 	if ((dev = vp->v_rdev) == NULL) {
1760 /*		if (vp->v_type != VBLK)
1761 			dev = get_dev(vp->v_uminor, vp->v_umajor); */
1762 	}
1763 	if (dev != NULL && dev->si_mountpoint)
1764 		return (EBUSY);
1765 	return (0);
1766 }
1767 
1768 /*
1769  * Unmount all filesystems. The list is traversed in reverse order
1770  * of mounting to avoid dependencies.
1771  */
1772 
1773 static int vfs_umountall_callback(struct mount *mp, void *data);
1774 
1775 void
1776 vfs_unmountall(void)
1777 {
1778 	int count;
1779 
1780 	do {
1781 		count = mountlist_scan(vfs_umountall_callback,
1782 					NULL, MNTSCAN_REVERSE|MNTSCAN_NOBUSY);
1783 	} while (count);
1784 }
1785 
1786 static
1787 int
1788 vfs_umountall_callback(struct mount *mp, void *data)
1789 {
1790 	int error;
1791 
1792 	error = dounmount(mp, MNT_FORCE);
1793 	if (error) {
1794 		mountlist_remove(mp);
1795 		kprintf("unmount of filesystem mounted from %s failed (",
1796 			mp->mnt_stat.f_mntfromname);
1797 		if (error == EBUSY)
1798 			kprintf("BUSY)\n");
1799 		else
1800 			kprintf("%d)\n", error);
1801 	}
1802 	return(1);
1803 }
1804 
1805 /*
1806  * Checks the mount flags for parameter mp and put the names comma-separated
1807  * into a string buffer buf with a size limit specified by len.
1808  *
1809  * It returns the number of bytes written into buf, and (*errorp) will be
1810  * set to 0, EINVAL (if passed length is 0), or ENOSPC (supplied buffer was
1811  * not large enough).  The buffer will be 0-terminated if len was not 0.
1812  */
1813 size_t
1814 vfs_flagstostr(int flags, const struct mountctl_opt *optp,
1815 	       char *buf, size_t len, int *errorp)
1816 {
1817 	static const struct mountctl_opt optnames[] = {
1818 		{ MNT_ASYNC,            "asynchronous" },
1819 		{ MNT_EXPORTED,         "NFS exported" },
1820 		{ MNT_LOCAL,            "local" },
1821 		{ MNT_NOATIME,          "noatime" },
1822 		{ MNT_NODEV,            "nodev" },
1823 		{ MNT_NOEXEC,           "noexec" },
1824 		{ MNT_NOSUID,           "nosuid" },
1825 		{ MNT_NOSYMFOLLOW,      "nosymfollow" },
1826 		{ MNT_QUOTA,            "with-quotas" },
1827 		{ MNT_RDONLY,           "read-only" },
1828 		{ MNT_SYNCHRONOUS,      "synchronous" },
1829 		{ MNT_UNION,            "union" },
1830 		{ MNT_NOCLUSTERR,       "noclusterr" },
1831 		{ MNT_NOCLUSTERW,       "noclusterw" },
1832 		{ MNT_SUIDDIR,          "suiddir" },
1833 		{ MNT_SOFTDEP,          "soft-updates" },
1834 		{ MNT_IGNORE,           "ignore" },
1835 		{ 0,			NULL}
1836 	};
1837 	int bwritten;
1838 	int bleft;
1839 	int optlen;
1840 	int actsize;
1841 
1842 	*errorp = 0;
1843 	bwritten = 0;
1844 	bleft = len - 1;	/* leave room for trailing \0 */
1845 
1846 	/*
1847 	 * Checks the size of the string. If it contains
1848 	 * any data, then we will append the new flags to
1849 	 * it.
1850 	 */
1851 	actsize = strlen(buf);
1852 	if (actsize > 0)
1853 		buf += actsize;
1854 
1855 	/* Default flags if no flags passed */
1856 	if (optp == NULL)
1857 		optp = optnames;
1858 
1859 	if (bleft < 0) {	/* degenerate case, 0-length buffer */
1860 		*errorp = EINVAL;
1861 		return(0);
1862 	}
1863 
1864 	for (; flags && optp->o_opt; ++optp) {
1865 		if ((flags & optp->o_opt) == 0)
1866 			continue;
1867 		optlen = strlen(optp->o_name);
1868 		if (bwritten || actsize > 0) {
1869 			if (bleft < 2) {
1870 				*errorp = ENOSPC;
1871 				break;
1872 			}
1873 			buf[bwritten++] = ',';
1874 			buf[bwritten++] = ' ';
1875 			bleft -= 2;
1876 		}
1877 		if (bleft < optlen) {
1878 			*errorp = ENOSPC;
1879 			break;
1880 		}
1881 		bcopy(optp->o_name, buf + bwritten, optlen);
1882 		bwritten += optlen;
1883 		bleft -= optlen;
1884 		flags &= ~optp->o_opt;
1885 	}
1886 
1887 	/*
1888 	 * Space already reserved for trailing \0
1889 	 */
1890 	buf[bwritten] = 0;
1891 	return (bwritten);
1892 }
1893 
1894 /*
1895  * Build hash lists of net addresses and hang them off the mount point.
1896  * Called by ufs_mount() to set up the lists of export addresses.
1897  */
1898 static int
1899 vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
1900 		const struct export_args *argp)
1901 {
1902 	struct netcred *np;
1903 	struct radix_node_head *rnh;
1904 	int i;
1905 	struct radix_node *rn;
1906 	struct sockaddr *saddr, *smask = 0;
1907 	struct domain *dom;
1908 	int error;
1909 
1910 	if (argp->ex_addrlen == 0) {
1911 		if (mp->mnt_flag & MNT_DEFEXPORTED)
1912 			return (EPERM);
1913 		np = &nep->ne_defexported;
1914 		np->netc_exflags = argp->ex_flags;
1915 		np->netc_anon = argp->ex_anon;
1916 		np->netc_anon.cr_ref = 1;
1917 		mp->mnt_flag |= MNT_DEFEXPORTED;
1918 		return (0);
1919 	}
1920 
1921 	if (argp->ex_addrlen < 0 || argp->ex_addrlen > MLEN)
1922 		return (EINVAL);
1923 	if (argp->ex_masklen < 0 || argp->ex_masklen > MLEN)
1924 		return (EINVAL);
1925 
1926 	i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
1927 	np = (struct netcred *) kmalloc(i, M_NETADDR, M_WAITOK | M_ZERO);
1928 	saddr = (struct sockaddr *) (np + 1);
1929 	if ((error = copyin(argp->ex_addr, (caddr_t) saddr, argp->ex_addrlen)))
1930 		goto out;
1931 	if (saddr->sa_len > argp->ex_addrlen)
1932 		saddr->sa_len = argp->ex_addrlen;
1933 	if (argp->ex_masklen) {
1934 		smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen);
1935 		error = copyin(argp->ex_mask, (caddr_t)smask, argp->ex_masklen);
1936 		if (error)
1937 			goto out;
1938 		if (smask->sa_len > argp->ex_masklen)
1939 			smask->sa_len = argp->ex_masklen;
1940 	}
1941 	i = saddr->sa_family;
1942 	if ((rnh = nep->ne_rtable[i]) == 0) {
1943 		/*
1944 		 * Seems silly to initialize every AF when most are not used,
1945 		 * do so on demand here
1946 		 */
1947 		SLIST_FOREACH(dom, &domains, dom_next)
1948 			if (dom->dom_family == i && dom->dom_rtattach) {
1949 				dom->dom_rtattach((void **) &nep->ne_rtable[i],
1950 				    dom->dom_rtoffset);
1951 				break;
1952 			}
1953 		if ((rnh = nep->ne_rtable[i]) == 0) {
1954 			error = ENOBUFS;
1955 			goto out;
1956 		}
1957 	}
1958 	rn = (*rnh->rnh_addaddr) ((char *) saddr, (char *) smask, rnh,
1959 	    np->netc_rnodes);
1960 	if (rn == 0 || np != (struct netcred *) rn) {	/* already exists */
1961 		error = EPERM;
1962 		goto out;
1963 	}
1964 	np->netc_exflags = argp->ex_flags;
1965 	np->netc_anon = argp->ex_anon;
1966 	np->netc_anon.cr_ref = 1;
1967 	return (0);
1968 out:
1969 	kfree(np, M_NETADDR);
1970 	return (error);
1971 }
1972 
1973 /* ARGSUSED */
1974 static int
1975 vfs_free_netcred(struct radix_node *rn, void *w)
1976 {
1977 	struct radix_node_head *rnh = (struct radix_node_head *) w;
1978 
1979 	(*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
1980 	kfree((caddr_t) rn, M_NETADDR);
1981 	return (0);
1982 }
1983 
1984 /*
1985  * Free the net address hash lists that are hanging off the mount points.
1986  */
1987 static void
1988 vfs_free_addrlist(struct netexport *nep)
1989 {
1990 	int i;
1991 	struct radix_node_head *rnh;
1992 
1993 	for (i = 0; i <= AF_MAX; i++)
1994 		if ((rnh = nep->ne_rtable[i])) {
1995 			(*rnh->rnh_walktree) (rnh, vfs_free_netcred,
1996 			    (caddr_t) rnh);
1997 			kfree((caddr_t) rnh, M_RTABLE);
1998 			nep->ne_rtable[i] = 0;
1999 		}
2000 }
2001 
2002 int
2003 vfs_export(struct mount *mp, struct netexport *nep,
2004 	   const struct export_args *argp)
2005 {
2006 	int error;
2007 
2008 	if (argp->ex_flags & MNT_DELEXPORT) {
2009 		if (mp->mnt_flag & MNT_EXPUBLIC) {
2010 			vfs_setpublicfs(NULL, NULL, NULL);
2011 			mp->mnt_flag &= ~MNT_EXPUBLIC;
2012 		}
2013 		vfs_free_addrlist(nep);
2014 		mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
2015 	}
2016 	if (argp->ex_flags & MNT_EXPORTED) {
2017 		if (argp->ex_flags & MNT_EXPUBLIC) {
2018 			if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
2019 				return (error);
2020 			mp->mnt_flag |= MNT_EXPUBLIC;
2021 		}
2022 		if ((error = vfs_hang_addrlist(mp, nep, argp)))
2023 			return (error);
2024 		mp->mnt_flag |= MNT_EXPORTED;
2025 	}
2026 	return (0);
2027 }
2028 
2029 
2030 /*
2031  * Set the publicly exported filesystem (WebNFS). Currently, only
2032  * one public filesystem is possible in the spec (RFC 2054 and 2055)
2033  */
2034 int
2035 vfs_setpublicfs(struct mount *mp, struct netexport *nep,
2036 		const struct export_args *argp)
2037 {
2038 	int error;
2039 	struct vnode *rvp;
2040 	char *cp;
2041 
2042 	/*
2043 	 * mp == NULL -> invalidate the current info, the FS is
2044 	 * no longer exported. May be called from either vfs_export
2045 	 * or unmount, so check if it hasn't already been done.
2046 	 */
2047 	if (mp == NULL) {
2048 		if (nfs_pub.np_valid) {
2049 			nfs_pub.np_valid = 0;
2050 			if (nfs_pub.np_index != NULL) {
2051 				FREE(nfs_pub.np_index, M_TEMP);
2052 				nfs_pub.np_index = NULL;
2053 			}
2054 		}
2055 		return (0);
2056 	}
2057 
2058 	/*
2059 	 * Only one allowed at a time.
2060 	 */
2061 	if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
2062 		return (EBUSY);
2063 
2064 	/*
2065 	 * Get real filehandle for root of exported FS.
2066 	 */
2067 	bzero((caddr_t)&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
2068 	nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
2069 
2070 	if ((error = VFS_ROOT(mp, &rvp)))
2071 		return (error);
2072 
2073 	if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
2074 		return (error);
2075 
2076 	vput(rvp);
2077 
2078 	/*
2079 	 * If an indexfile was specified, pull it in.
2080 	 */
2081 	if (argp->ex_indexfile != NULL) {
2082 		int namelen;
2083 
2084 		error = vn_get_namelen(rvp, &namelen);
2085 		if (error)
2086 			return (error);
2087 		MALLOC(nfs_pub.np_index, char *, namelen, M_TEMP,
2088 		    M_WAITOK);
2089 		error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
2090 		    namelen, NULL);
2091 		if (!error) {
2092 			/*
2093 			 * Check for illegal filenames.
2094 			 */
2095 			for (cp = nfs_pub.np_index; *cp; cp++) {
2096 				if (*cp == '/') {
2097 					error = EINVAL;
2098 					break;
2099 				}
2100 			}
2101 		}
2102 		if (error) {
2103 			FREE(nfs_pub.np_index, M_TEMP);
2104 			return (error);
2105 		}
2106 	}
2107 
2108 	nfs_pub.np_mount = mp;
2109 	nfs_pub.np_valid = 1;
2110 	return (0);
2111 }
2112 
2113 struct netcred *
2114 vfs_export_lookup(struct mount *mp, struct netexport *nep,
2115 		struct sockaddr *nam)
2116 {
2117 	struct netcred *np;
2118 	struct radix_node_head *rnh;
2119 	struct sockaddr *saddr;
2120 
2121 	np = NULL;
2122 	if (mp->mnt_flag & MNT_EXPORTED) {
2123 		/*
2124 		 * Lookup in the export list first.
2125 		 */
2126 		if (nam != NULL) {
2127 			saddr = nam;
2128 			rnh = nep->ne_rtable[saddr->sa_family];
2129 			if (rnh != NULL) {
2130 				np = (struct netcred *)
2131 					(*rnh->rnh_matchaddr)((char *)saddr,
2132 							      rnh);
2133 				if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
2134 					np = NULL;
2135 			}
2136 		}
2137 		/*
2138 		 * If no address match, use the default if it exists.
2139 		 */
2140 		if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
2141 			np = &nep->ne_defexported;
2142 	}
2143 	return (np);
2144 }
2145 
2146 /*
2147  * perform msync on all vnodes under a mount point.  The mount point must
2148  * be locked.  This code is also responsible for lazy-freeing unreferenced
2149  * vnodes whos VM objects no longer contain pages.
2150  *
2151  * NOTE: MNT_WAIT still skips vnodes in the VXLOCK state.
2152  *
2153  * NOTE: XXX VOP_PUTPAGES and friends requires that the vnode be locked,
2154  * but vnode_pager_putpages() doesn't lock the vnode.  We have to do it
2155  * way up in this high level function.
2156  */
2157 static int vfs_msync_scan1(struct mount *mp, struct vnode *vp, void *data);
2158 static int vfs_msync_scan2(struct mount *mp, struct vnode *vp, void *data);
2159 
2160 void
2161 vfs_msync(struct mount *mp, int flags)
2162 {
2163 	int vmsc_flags;
2164 
2165 	/*
2166 	 * tmpfs sets this flag to prevent msync(), sync, and the
2167 	 * filesystem periodic syncer from trying to flush VM pages
2168 	 * to swap.  Only pure memory pressure flushes tmpfs VM pages
2169 	 * to swap.
2170 	 */
2171 	if (mp->mnt_kern_flag & MNTK_NOMSYNC)
2172 		return;
2173 
2174 	/*
2175 	 * Ok, scan the vnodes for work.
2176 	 */
2177 	vmsc_flags = VMSC_GETVP;
2178 	if (flags != MNT_WAIT)
2179 		vmsc_flags |= VMSC_NOWAIT;
2180 	vmntvnodescan(mp, vmsc_flags, vfs_msync_scan1, vfs_msync_scan2,
2181 			(void *)(intptr_t)flags);
2182 }
2183 
2184 /*
2185  * scan1 is a fast pre-check.  There could be hundreds of thousands of
2186  * vnodes, we cannot afford to do anything heavy weight until we have a
2187  * fairly good indication that there is work to do.
2188  */
2189 static
2190 int
2191 vfs_msync_scan1(struct mount *mp, struct vnode *vp, void *data)
2192 {
2193 	int flags = (int)(intptr_t)data;
2194 
2195 	if ((vp->v_flag & VRECLAIMED) == 0) {
2196 		if (vshouldmsync(vp))
2197 			return(0);	/* call scan2 */
2198 		if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
2199 		    (vp->v_flag & VOBJDIRTY) &&
2200 		    (flags == MNT_WAIT || vn_islocked(vp) == 0)) {
2201 			return(0);	/* call scan2 */
2202 		}
2203 	}
2204 
2205 	/*
2206 	 * do not call scan2, continue the loop
2207 	 */
2208 	return(-1);
2209 }
2210 
2211 /*
2212  * This callback is handed a locked vnode.
2213  */
2214 static
2215 int
2216 vfs_msync_scan2(struct mount *mp, struct vnode *vp, void *data)
2217 {
2218 	vm_object_t obj;
2219 	int flags = (int)(intptr_t)data;
2220 
2221 	if (vp->v_flag & VRECLAIMED)
2222 		return(0);
2223 
2224 	if ((mp->mnt_flag & MNT_RDONLY) == 0 && (vp->v_flag & VOBJDIRTY)) {
2225 		if ((obj = vp->v_object) != NULL) {
2226 			vm_object_page_clean(obj, 0, 0,
2227 			 flags == MNT_WAIT ? OBJPC_SYNC : OBJPC_NOSYNC);
2228 		}
2229 	}
2230 	return(0);
2231 }
2232 
2233 /*
2234  * Wake up anyone interested in vp because it is being revoked.
2235  */
2236 void
2237 vn_gone(struct vnode *vp)
2238 {
2239 	lwkt_gettoken(&vp->v_token);
2240 	KNOTE(&vp->v_pollinfo.vpi_kqinfo.ki_note, NOTE_REVOKE);
2241 	lwkt_reltoken(&vp->v_token);
2242 }
2243 
2244 /*
2245  * extract the cdev_t from a VBLK or VCHR.  The vnode must have been opened
2246  * (or v_rdev might be NULL).
2247  */
2248 cdev_t
2249 vn_todev(struct vnode *vp)
2250 {
2251 	if (vp->v_type != VBLK && vp->v_type != VCHR)
2252 		return (NULL);
2253 	KKASSERT(vp->v_rdev != NULL);
2254 	return (vp->v_rdev);
2255 }
2256 
2257 /*
2258  * Check if vnode represents a disk device.  The vnode does not need to be
2259  * opened.
2260  *
2261  * MPALMOSTSAFE
2262  */
2263 int
2264 vn_isdisk(struct vnode *vp, int *errp)
2265 {
2266 	cdev_t dev;
2267 
2268 	if (vp->v_type != VCHR) {
2269 		if (errp != NULL)
2270 			*errp = ENOTBLK;
2271 		return (0);
2272 	}
2273 
2274 	dev = vp->v_rdev;
2275 
2276 	if (dev == NULL) {
2277 		if (errp != NULL)
2278 			*errp = ENXIO;
2279 		return (0);
2280 	}
2281 	if (dev_is_good(dev) == 0) {
2282 		if (errp != NULL)
2283 			*errp = ENXIO;
2284 		return (0);
2285 	}
2286 	if ((dev_dflags(dev) & D_DISK) == 0) {
2287 		if (errp != NULL)
2288 			*errp = ENOTBLK;
2289 		return (0);
2290 	}
2291 	if (errp != NULL)
2292 		*errp = 0;
2293 	return (1);
2294 }
2295 
2296 int
2297 vn_get_namelen(struct vnode *vp, int *namelen)
2298 {
2299 	int error;
2300 	register_t retval[2];
2301 
2302 	error = VOP_PATHCONF(vp, _PC_NAME_MAX, retval);
2303 	if (error)
2304 		return (error);
2305 	*namelen = (int)retval[0];
2306 	return (0);
2307 }
2308 
2309 int
2310 vop_write_dirent(int *error, struct uio *uio, ino_t d_ino, uint8_t d_type,
2311 		uint16_t d_namlen, const char *d_name)
2312 {
2313 	struct dirent *dp;
2314 	size_t len;
2315 
2316 	len = _DIRENT_RECLEN(d_namlen);
2317 	if (len > uio->uio_resid)
2318 		return(1);
2319 
2320 	dp = kmalloc(len, M_TEMP, M_WAITOK | M_ZERO);
2321 
2322 	dp->d_ino = d_ino;
2323 	dp->d_namlen = d_namlen;
2324 	dp->d_type = d_type;
2325 	bcopy(d_name, dp->d_name, d_namlen);
2326 
2327 	*error = uiomove((caddr_t)dp, len, uio);
2328 
2329 	kfree(dp, M_TEMP);
2330 
2331 	return(0);
2332 }
2333 
2334 void
2335 vn_mark_atime(struct vnode *vp, struct thread *td)
2336 {
2337 	struct proc *p = td->td_proc;
2338 	struct ucred *cred = p ? p->p_ucred : proc0.p_ucred;
2339 
2340 	if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) {
2341 		VOP_MARKATIME(vp, cred);
2342 	}
2343 }
2344