xref: /dragonfly/sys/kern/vfs_subr.c (revision 0dace59e)
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. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)vfs_subr.c	8.31 (Berkeley) 5/26/95
35  * $FreeBSD: src/sys/kern/vfs_subr.c,v 1.249.2.30 2003/04/04 20:35:57 tegge Exp $
36  */
37 
38 /*
39  * External virtual filesystem routines
40  */
41 #include "opt_ddb.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/buf.h>
46 #include <sys/conf.h>
47 #include <sys/dirent.h>
48 #include <sys/domain.h>
49 #include <sys/eventhandler.h>
50 #include <sys/fcntl.h>
51 #include <sys/file.h>
52 #include <sys/kernel.h>
53 #include <sys/kthread.h>
54 #include <sys/malloc.h>
55 #include <sys/mbuf.h>
56 #include <sys/mount.h>
57 #include <sys/priv.h>
58 #include <sys/proc.h>
59 #include <sys/reboot.h>
60 #include <sys/socket.h>
61 #include <sys/stat.h>
62 #include <sys/sysctl.h>
63 #include <sys/syslog.h>
64 #include <sys/unistd.h>
65 #include <sys/vmmeter.h>
66 #include <sys/vnode.h>
67 
68 #include <machine/limits.h>
69 
70 #include <vm/vm.h>
71 #include <vm/vm_object.h>
72 #include <vm/vm_extern.h>
73 #include <vm/vm_kern.h>
74 #include <vm/pmap.h>
75 #include <vm/vm_map.h>
76 #include <vm/vm_page.h>
77 #include <vm/vm_pager.h>
78 #include <vm/vnode_pager.h>
79 #include <vm/vm_zone.h>
80 
81 #include <sys/buf2.h>
82 #include <sys/thread2.h>
83 #include <sys/sysref2.h>
84 #include <sys/mplock2.h>
85 
86 static MALLOC_DEFINE(M_NETADDR, "Export Host", "Export host address structure");
87 
88 int numvnodes;
89 SYSCTL_INT(_debug, OID_AUTO, numvnodes, CTLFLAG_RD, &numvnodes, 0,
90     "Number of vnodes allocated");
91 int verbose_reclaims;
92 SYSCTL_INT(_debug, OID_AUTO, verbose_reclaims, CTLFLAG_RD, &verbose_reclaims, 0,
93     "Output filename of reclaimed vnode(s)");
94 
95 enum vtype iftovt_tab[16] = {
96 	VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
97 	VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
98 };
99 int vttoif_tab[9] = {
100 	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
101 	S_IFSOCK, S_IFIFO, S_IFMT,
102 };
103 
104 static int reassignbufcalls;
105 SYSCTL_INT(_vfs, OID_AUTO, reassignbufcalls, CTLFLAG_RW, &reassignbufcalls,
106     0, "Number of times buffers have been reassigned to the proper list");
107 
108 static int check_buf_overlap = 2;	/* invasive check */
109 SYSCTL_INT(_vfs, OID_AUTO, check_buf_overlap, CTLFLAG_RW, &check_buf_overlap,
110     0, "Enable overlapping buffer checks");
111 
112 int	nfs_mount_type = -1;
113 static struct lwkt_token spechash_token;
114 struct nfs_public nfs_pub;	/* publicly exported FS */
115 
116 int desiredvnodes;
117 SYSCTL_INT(_kern, KERN_MAXVNODES, maxvnodes, CTLFLAG_RW,
118 		&desiredvnodes, 0, "Maximum number of vnodes");
119 
120 static void	vfs_free_addrlist (struct netexport *nep);
121 static int	vfs_free_netcred (struct radix_node *rn, void *w);
122 static int	vfs_hang_addrlist (struct mount *mp, struct netexport *nep,
123 				       const struct export_args *argp);
124 
125 /*
126  * Red black tree functions
127  */
128 static int rb_buf_compare(struct buf *b1, struct buf *b2);
129 RB_GENERATE2(buf_rb_tree, buf, b_rbnode, rb_buf_compare, off_t, b_loffset);
130 RB_GENERATE2(buf_rb_hash, buf, b_rbhash, rb_buf_compare, off_t, b_loffset);
131 
132 static int
133 rb_buf_compare(struct buf *b1, struct buf *b2)
134 {
135 	if (b1->b_loffset < b2->b_loffset)
136 		return(-1);
137 	if (b1->b_loffset > b2->b_loffset)
138 		return(1);
139 	return(0);
140 }
141 
142 /*
143  * Returns non-zero if the vnode is a candidate for lazy msyncing.
144  *
145  * NOTE: v_object is not stable (this scan can race), however the
146  *	 mntvnodescan code holds vmobj_token so any VM object we
147  *	 do find will remain stable storage.
148  */
149 static __inline int
150 vshouldmsync(struct vnode *vp)
151 {
152 	vm_object_t object;
153 
154 	if (vp->v_auxrefs != 0 || vp->v_sysref.refcnt > 0)
155 		return (0);		/* other holders */
156 	object = vp->v_object;
157 	cpu_ccfence();
158 	if (object && (object->ref_count || object->resident_page_count))
159 		return(0);
160 	return (1);
161 }
162 
163 /*
164  * Initialize the vnode management data structures.
165  *
166  * Called from vfsinit()
167  */
168 void
169 vfs_subr_init(void)
170 {
171 	int factor1;
172 	int factor2;
173 
174 	/*
175 	 * Desiredvnodes is kern.maxvnodes.  We want to scale it
176 	 * according to available system memory but we may also have
177 	 * to limit it based on available KVM, which is capped on 32 bit
178 	 * systems, to ~80K vnodes or so.
179 	 *
180 	 * WARNING!  For machines with 64-256M of ram we have to be sure
181 	 *	     that the default limit scales down well due to HAMMER
182 	 *	     taking up significantly more memory per-vnode vs UFS.
183 	 *	     We want around ~5800 on a 128M machine.
184 	 */
185 	factor1 = 20 * (sizeof(struct vm_object) + sizeof(struct vnode));
186 	factor2 = 25 * (sizeof(struct vm_object) + sizeof(struct vnode));
187 	desiredvnodes =
188 		imin((int64_t)vmstats.v_page_count * PAGE_SIZE / factor1,
189 		     KvaSize / factor2);
190 	desiredvnodes = imax(desiredvnodes, maxproc * 8);
191 
192 	lwkt_token_init(&spechash_token, "spechash");
193 }
194 
195 /*
196  * Knob to control the precision of file timestamps:
197  *
198  *   0 = seconds only; nanoseconds zeroed.
199  *   1 = seconds and nanoseconds, accurate within 1/HZ.
200  *   2 = seconds and nanoseconds, truncated to microseconds.
201  * >=3 = seconds and nanoseconds, maximum precision.
202  */
203 enum { TSP_SEC, TSP_HZ, TSP_USEC, TSP_NSEC };
204 
205 static int timestamp_precision = TSP_SEC;
206 SYSCTL_INT(_vfs, OID_AUTO, timestamp_precision, CTLFLAG_RW,
207 		&timestamp_precision, 0, "Precision of file timestamps");
208 
209 /*
210  * Get a current timestamp.
211  *
212  * MPSAFE
213  */
214 void
215 vfs_timestamp(struct timespec *tsp)
216 {
217 	struct timeval tv;
218 
219 	switch (timestamp_precision) {
220 	case TSP_SEC:
221 		tsp->tv_sec = time_second;
222 		tsp->tv_nsec = 0;
223 		break;
224 	case TSP_HZ:
225 		getnanotime(tsp);
226 		break;
227 	case TSP_USEC:
228 		microtime(&tv);
229 		TIMEVAL_TO_TIMESPEC(&tv, tsp);
230 		break;
231 	case TSP_NSEC:
232 	default:
233 		nanotime(tsp);
234 		break;
235 	}
236 }
237 
238 /*
239  * Set vnode attributes to VNOVAL
240  */
241 void
242 vattr_null(struct vattr *vap)
243 {
244 	vap->va_type = VNON;
245 	vap->va_size = VNOVAL;
246 	vap->va_bytes = VNOVAL;
247 	vap->va_mode = VNOVAL;
248 	vap->va_nlink = VNOVAL;
249 	vap->va_uid = VNOVAL;
250 	vap->va_gid = VNOVAL;
251 	vap->va_fsid = VNOVAL;
252 	vap->va_fileid = VNOVAL;
253 	vap->va_blocksize = VNOVAL;
254 	vap->va_rmajor = VNOVAL;
255 	vap->va_rminor = VNOVAL;
256 	vap->va_atime.tv_sec = VNOVAL;
257 	vap->va_atime.tv_nsec = VNOVAL;
258 	vap->va_mtime.tv_sec = VNOVAL;
259 	vap->va_mtime.tv_nsec = VNOVAL;
260 	vap->va_ctime.tv_sec = VNOVAL;
261 	vap->va_ctime.tv_nsec = VNOVAL;
262 	vap->va_flags = VNOVAL;
263 	vap->va_gen = VNOVAL;
264 	vap->va_vaflags = 0;
265 	/* va_*_uuid fields are only valid if related flags are set */
266 }
267 
268 /*
269  * Flush out and invalidate all buffers associated with a vnode.
270  *
271  * vp must be locked.
272  */
273 static int vinvalbuf_bp(struct buf *bp, void *data);
274 
275 struct vinvalbuf_bp_info {
276 	struct vnode *vp;
277 	int slptimeo;
278 	int lkflags;
279 	int flags;
280 	int clean;
281 };
282 
283 int
284 vinvalbuf(struct vnode *vp, int flags, int slpflag, int slptimeo)
285 {
286 	struct vinvalbuf_bp_info info;
287 	vm_object_t object;
288 	int error;
289 
290 	lwkt_gettoken(&vp->v_token);
291 
292 	/*
293 	 * If we are being asked to save, call fsync to ensure that the inode
294 	 * is updated.
295 	 */
296 	if (flags & V_SAVE) {
297 		error = bio_track_wait(&vp->v_track_write, slpflag, slptimeo);
298 		if (error)
299 			goto done;
300 		if (!RB_EMPTY(&vp->v_rbdirty_tree)) {
301 			if ((error = VOP_FSYNC(vp, MNT_WAIT, 0)) != 0)
302 				goto done;
303 #if 0
304 			/*
305 			 * Dirty bufs may be left or generated via races
306 			 * in circumstances where vinvalbuf() is called on
307 			 * a vnode not undergoing reclamation.   Only
308 			 * panic if we are trying to reclaim the vnode.
309 			 */
310 			if ((vp->v_flag & VRECLAIMED) &&
311 			    (bio_track_active(&vp->v_track_write) ||
312 			    !RB_EMPTY(&vp->v_rbdirty_tree))) {
313 				panic("vinvalbuf: dirty bufs");
314 			}
315 #endif
316 		}
317   	}
318 	info.slptimeo = slptimeo;
319 	info.lkflags = LK_EXCLUSIVE | LK_SLEEPFAIL;
320 	if (slpflag & PCATCH)
321 		info.lkflags |= LK_PCATCH;
322 	info.flags = flags;
323 	info.vp = vp;
324 
325 	/*
326 	 * Flush the buffer cache until nothing is left, wait for all I/O
327 	 * to complete.  At least one pass is required.  We might block
328 	 * in the pip code so we have to re-check.  Order is important.
329 	 */
330 	do {
331 		/*
332 		 * Flush buffer cache
333 		 */
334 		if (!RB_EMPTY(&vp->v_rbclean_tree)) {
335 			info.clean = 1;
336 			error = RB_SCAN(buf_rb_tree, &vp->v_rbclean_tree,
337 					NULL, vinvalbuf_bp, &info);
338 		}
339 		if (!RB_EMPTY(&vp->v_rbdirty_tree)) {
340 			info.clean = 0;
341 			error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
342 					NULL, vinvalbuf_bp, &info);
343 		}
344 
345 		/*
346 		 * Wait for I/O completion.
347 		 */
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 	} while (bio_track_active(&vp->v_track_write) ||
352 		 !RB_EMPTY(&vp->v_rbclean_tree) ||
353 		 !RB_EMPTY(&vp->v_rbdirty_tree));
354 
355 	/*
356 	 * Destroy the copy in the VM cache, too.
357 	 */
358 	if ((object = vp->v_object) != NULL) {
359 		vm_object_page_remove(object, 0, 0,
360 			(flags & V_SAVE) ? TRUE : FALSE);
361 	}
362 
363 	if (!RB_EMPTY(&vp->v_rbdirty_tree) || !RB_EMPTY(&vp->v_rbclean_tree))
364 		panic("vinvalbuf: flush failed");
365 	if (!RB_EMPTY(&vp->v_rbhash_tree))
366 		panic("vinvalbuf: flush failed, buffers still present");
367 	error = 0;
368 done:
369 	lwkt_reltoken(&vp->v_token);
370 	return (error);
371 }
372 
373 static int
374 vinvalbuf_bp(struct buf *bp, void *data)
375 {
376 	struct vinvalbuf_bp_info *info = data;
377 	int error;
378 
379 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
380 		atomic_add_int(&bp->b_refs, 1);
381 		error = BUF_TIMELOCK(bp, info->lkflags,
382 				     "vinvalbuf", info->slptimeo);
383 		atomic_subtract_int(&bp->b_refs, 1);
384 		if (error == 0) {
385 			BUF_UNLOCK(bp);
386 			error = ENOLCK;
387 		}
388 		if (error == ENOLCK)
389 			return(0);
390 		return (-error);
391 	}
392 	KKASSERT(bp->b_vp == info->vp);
393 
394 	/*
395 	 * Must check clean/dirty status after successfully locking as
396 	 * it may race.
397 	 */
398 	if ((info->clean && (bp->b_flags & B_DELWRI)) ||
399 	    (info->clean == 0 && (bp->b_flags & B_DELWRI) == 0)) {
400 		BUF_UNLOCK(bp);
401 		return(0);
402 	}
403 
404 	/*
405 	 * NOTE:  NO B_LOCKED CHECK.  Also no buf_checkwrite()
406 	 * check.  This code will write out the buffer, period.
407 	 */
408 	bremfree(bp);
409 	if (((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI) &&
410 	    (info->flags & V_SAVE)) {
411 		cluster_awrite(bp);
412 	} else if (info->flags & V_SAVE) {
413 		/*
414 		 * Cannot set B_NOCACHE on a clean buffer as this will
415 		 * destroy the VM backing store which might actually
416 		 * be dirty (and unsynchronized).
417 		 */
418 		bp->b_flags |= (B_INVAL | B_RELBUF);
419 		brelse(bp);
420 	} else {
421 		bp->b_flags |= (B_INVAL | B_NOCACHE | B_RELBUF);
422 		brelse(bp);
423 	}
424 	return(0);
425 }
426 
427 /*
428  * Truncate a file's buffer and pages to a specified length.  This
429  * is in lieu of the old vinvalbuf mechanism, which performed unneeded
430  * sync activity.
431  *
432  * The vnode must be locked.
433  */
434 static int vtruncbuf_bp_trunc_cmp(struct buf *bp, void *data);
435 static int vtruncbuf_bp_trunc(struct buf *bp, void *data);
436 static int vtruncbuf_bp_metasync_cmp(struct buf *bp, void *data);
437 static int vtruncbuf_bp_metasync(struct buf *bp, void *data);
438 
439 struct vtruncbuf_info {
440 	struct vnode *vp;
441 	off_t	truncloffset;
442 	int	clean;
443 };
444 
445 int
446 vtruncbuf(struct vnode *vp, off_t length, int blksize)
447 {
448 	struct vtruncbuf_info info;
449 	const char *filename;
450 	int count;
451 
452 	/*
453 	 * Round up to the *next* block, then destroy the buffers in question.
454 	 * Since we are only removing some of the buffers we must rely on the
455 	 * scan count to determine whether a loop is necessary.
456 	 */
457 	if ((count = (int)(length % blksize)) != 0)
458 		info.truncloffset = length + (blksize - count);
459 	else
460 		info.truncloffset = length;
461 	info.vp = vp;
462 
463 	lwkt_gettoken(&vp->v_token);
464 	do {
465 		info.clean = 1;
466 		count = RB_SCAN(buf_rb_tree, &vp->v_rbclean_tree,
467 				vtruncbuf_bp_trunc_cmp,
468 				vtruncbuf_bp_trunc, &info);
469 		info.clean = 0;
470 		count += RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
471 				vtruncbuf_bp_trunc_cmp,
472 				vtruncbuf_bp_trunc, &info);
473 	} while(count);
474 
475 	/*
476 	 * For safety, fsync any remaining metadata if the file is not being
477 	 * truncated to 0.  Since the metadata does not represent the entire
478 	 * dirty list we have to rely on the hit count to ensure that we get
479 	 * all of it.
480 	 */
481 	if (length > 0) {
482 		do {
483 			count = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
484 					vtruncbuf_bp_metasync_cmp,
485 					vtruncbuf_bp_metasync, &info);
486 		} while (count);
487 	}
488 
489 	/*
490 	 * Clean out any left over VM backing store.
491 	 *
492 	 * It is possible to have in-progress I/O from buffers that were
493 	 * not part of the truncation.  This should not happen if we
494 	 * are truncating to 0-length.
495 	 */
496 	vnode_pager_setsize(vp, length);
497 	bio_track_wait(&vp->v_track_write, 0, 0);
498 
499 	/*
500 	 * Debugging only
501 	 */
502 	spin_lock(&vp->v_spin);
503 	filename = TAILQ_FIRST(&vp->v_namecache) ?
504 		   TAILQ_FIRST(&vp->v_namecache)->nc_name : "?";
505 	spin_unlock(&vp->v_spin);
506 
507 	/*
508 	 * Make sure no buffers were instantiated while we were trying
509 	 * to clean out the remaining VM pages.  This could occur due
510 	 * to busy dirty VM pages being flushed out to disk.
511 	 */
512 	do {
513 		info.clean = 1;
514 		count = RB_SCAN(buf_rb_tree, &vp->v_rbclean_tree,
515 				vtruncbuf_bp_trunc_cmp,
516 				vtruncbuf_bp_trunc, &info);
517 		info.clean = 0;
518 		count += RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
519 				vtruncbuf_bp_trunc_cmp,
520 				vtruncbuf_bp_trunc, &info);
521 		if (count) {
522 			kprintf("Warning: vtruncbuf():  Had to re-clean %d "
523 			       "left over buffers in %s\n", count, filename);
524 		}
525 	} while(count);
526 
527 	lwkt_reltoken(&vp->v_token);
528 
529 	return (0);
530 }
531 
532 /*
533  * The callback buffer is beyond the new file EOF and must be destroyed.
534  * Note that the compare function must conform to the RB_SCAN's requirements.
535  */
536 static
537 int
538 vtruncbuf_bp_trunc_cmp(struct buf *bp, void *data)
539 {
540 	struct vtruncbuf_info *info = data;
541 
542 	if (bp->b_loffset >= info->truncloffset)
543 		return(0);
544 	return(-1);
545 }
546 
547 static
548 int
549 vtruncbuf_bp_trunc(struct buf *bp, void *data)
550 {
551 	struct vtruncbuf_info *info = data;
552 
553 	/*
554 	 * Do not try to use a buffer we cannot immediately lock, but sleep
555 	 * anyway to prevent a livelock.  The code will loop until all buffers
556 	 * can be acted upon.
557 	 *
558 	 * We must always revalidate the buffer after locking it to deal
559 	 * with MP races.
560 	 */
561 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
562 		atomic_add_int(&bp->b_refs, 1);
563 		if (BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL) == 0)
564 			BUF_UNLOCK(bp);
565 		atomic_subtract_int(&bp->b_refs, 1);
566 	} else if ((info->clean && (bp->b_flags & B_DELWRI)) ||
567 		   (info->clean == 0 && (bp->b_flags & B_DELWRI) == 0) ||
568 		   bp->b_vp != info->vp ||
569 		   vtruncbuf_bp_trunc_cmp(bp, data)) {
570 		BUF_UNLOCK(bp);
571 	} else {
572 		bremfree(bp);
573 		bp->b_flags |= (B_INVAL | B_RELBUF | B_NOCACHE);
574 		brelse(bp);
575 	}
576 	return(1);
577 }
578 
579 /*
580  * Fsync all meta-data after truncating a file to be non-zero.  Only metadata
581  * blocks (with a negative loffset) are scanned.
582  * Note that the compare function must conform to the RB_SCAN's requirements.
583  */
584 static int
585 vtruncbuf_bp_metasync_cmp(struct buf *bp, void *data __unused)
586 {
587 	if (bp->b_loffset < 0)
588 		return(0);
589 	return(1);
590 }
591 
592 static int
593 vtruncbuf_bp_metasync(struct buf *bp, void *data)
594 {
595 	struct vtruncbuf_info *info = data;
596 
597 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
598 		atomic_add_int(&bp->b_refs, 1);
599 		if (BUF_LOCK(bp, LK_EXCLUSIVE|LK_SLEEPFAIL) == 0)
600 			BUF_UNLOCK(bp);
601 		atomic_subtract_int(&bp->b_refs, 1);
602 	} else if ((bp->b_flags & B_DELWRI) == 0 ||
603 		   bp->b_vp != info->vp ||
604 		   vtruncbuf_bp_metasync_cmp(bp, data)) {
605 		BUF_UNLOCK(bp);
606 	} else {
607 		bremfree(bp);
608 		if (bp->b_vp == info->vp)
609 			bawrite(bp);
610 		else
611 			bwrite(bp);
612 	}
613 	return(1);
614 }
615 
616 /*
617  * vfsync - implements a multipass fsync on a file which understands
618  * dependancies and meta-data.  The passed vnode must be locked.  The
619  * waitfor argument may be MNT_WAIT or MNT_NOWAIT, or MNT_LAZY.
620  *
621  * When fsyncing data asynchronously just do one consolidated pass starting
622  * with the most negative block number.  This may not get all the data due
623  * to dependancies.
624  *
625  * When fsyncing data synchronously do a data pass, then a metadata pass,
626  * then do additional data+metadata passes to try to get all the data out.
627  */
628 static int vfsync_wait_output(struct vnode *vp,
629 			    int (*waitoutput)(struct vnode *, struct thread *));
630 static int vfsync_dummy_cmp(struct buf *bp __unused, void *data __unused);
631 static int vfsync_data_only_cmp(struct buf *bp, void *data);
632 static int vfsync_meta_only_cmp(struct buf *bp, void *data);
633 static int vfsync_lazy_range_cmp(struct buf *bp, void *data);
634 static int vfsync_bp(struct buf *bp, void *data);
635 
636 struct vfsync_info {
637 	struct vnode *vp;
638 	int synchronous;
639 	int syncdeps;
640 	int lazycount;
641 	int lazylimit;
642 	int skippedbufs;
643 	int (*checkdef)(struct buf *);
644 	int (*cmpfunc)(struct buf *, void *);
645 };
646 
647 int
648 vfsync(struct vnode *vp, int waitfor, int passes,
649 	int (*checkdef)(struct buf *),
650 	int (*waitoutput)(struct vnode *, struct thread *))
651 {
652 	struct vfsync_info info;
653 	int error;
654 
655 	bzero(&info, sizeof(info));
656 	info.vp = vp;
657 	if ((info.checkdef = checkdef) == NULL)
658 		info.syncdeps = 1;
659 
660 	lwkt_gettoken(&vp->v_token);
661 
662 	switch(waitfor) {
663 	case MNT_LAZY | MNT_NOWAIT:
664 	case MNT_LAZY:
665 		/*
666 		 * Lazy (filesystem syncer typ) Asynchronous plus limit the
667 		 * number of data (not meta) pages we try to flush to 1MB.
668 		 * A non-zero return means that lazy limit was reached.
669 		 */
670 		info.lazylimit = 1024 * 1024;
671 		info.syncdeps = 1;
672 		info.cmpfunc = vfsync_lazy_range_cmp;
673 		error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
674 				vfsync_lazy_range_cmp, vfsync_bp, &info);
675 		info.cmpfunc = vfsync_meta_only_cmp;
676 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree,
677 			vfsync_meta_only_cmp, vfsync_bp, &info);
678 		if (error == 0)
679 			vp->v_lazyw = 0;
680 		else if (!RB_EMPTY(&vp->v_rbdirty_tree))
681 			vn_syncer_add(vp, 1);
682 		error = 0;
683 		break;
684 	case MNT_NOWAIT:
685 		/*
686 		 * Asynchronous.  Do a data-only pass and a meta-only pass.
687 		 */
688 		info.syncdeps = 1;
689 		info.cmpfunc = vfsync_data_only_cmp;
690 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, vfsync_data_only_cmp,
691 			vfsync_bp, &info);
692 		info.cmpfunc = vfsync_meta_only_cmp;
693 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, vfsync_meta_only_cmp,
694 			vfsync_bp, &info);
695 		error = 0;
696 		break;
697 	default:
698 		/*
699 		 * Synchronous.  Do a data-only pass, then a meta-data+data
700 		 * pass, then additional integrated passes to try to get
701 		 * all the dependancies flushed.
702 		 */
703 		info.cmpfunc = vfsync_data_only_cmp;
704 		RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, vfsync_data_only_cmp,
705 			vfsync_bp, &info);
706 		error = vfsync_wait_output(vp, waitoutput);
707 		if (error == 0) {
708 			info.skippedbufs = 0;
709 			info.cmpfunc = vfsync_dummy_cmp;
710 			RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
711 				vfsync_bp, &info);
712 			error = vfsync_wait_output(vp, waitoutput);
713 			if (info.skippedbufs) {
714 				kprintf("Warning: vfsync skipped %d dirty "
715 					"bufs in pass2!\n", info.skippedbufs);
716 			}
717 		}
718 		while (error == 0 && passes > 0 &&
719 		       !RB_EMPTY(&vp->v_rbdirty_tree)
720 		) {
721 			if (--passes == 0) {
722 				info.synchronous = 1;
723 				info.syncdeps = 1;
724 			}
725 			info.cmpfunc = vfsync_dummy_cmp;
726 			error = RB_SCAN(buf_rb_tree, &vp->v_rbdirty_tree, NULL,
727 					vfsync_bp, &info);
728 			if (error < 0)
729 				error = -error;
730 			info.syncdeps = 1;
731 			if (error == 0)
732 				error = vfsync_wait_output(vp, waitoutput);
733 		}
734 		break;
735 	}
736 	lwkt_reltoken(&vp->v_token);
737 	return(error);
738 }
739 
740 static int
741 vfsync_wait_output(struct vnode *vp,
742 		   int (*waitoutput)(struct vnode *, struct thread *))
743 {
744 	int error;
745 
746 	error = bio_track_wait(&vp->v_track_write, 0, 0);
747 	if (waitoutput)
748 		error = waitoutput(vp, curthread);
749 	return(error);
750 }
751 
752 static int
753 vfsync_dummy_cmp(struct buf *bp __unused, void *data __unused)
754 {
755 	return(0);
756 }
757 
758 static int
759 vfsync_data_only_cmp(struct buf *bp, void *data)
760 {
761 	if (bp->b_loffset < 0)
762 		return(-1);
763 	return(0);
764 }
765 
766 static int
767 vfsync_meta_only_cmp(struct buf *bp, void *data)
768 {
769 	if (bp->b_loffset < 0)
770 		return(0);
771 	return(1);
772 }
773 
774 static int
775 vfsync_lazy_range_cmp(struct buf *bp, void *data)
776 {
777 	struct vfsync_info *info = data;
778 
779 	if (bp->b_loffset < info->vp->v_lazyw)
780 		return(-1);
781 	return(0);
782 }
783 
784 static int
785 vfsync_bp(struct buf *bp, void *data)
786 {
787 	struct vfsync_info *info = data;
788 	struct vnode *vp = info->vp;
789 	int error;
790 
791 	/*
792 	 * Ignore buffers that we cannot immediately lock.
793 	 */
794 	if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT)) {
795 		++info->skippedbufs;
796 		return(0);
797 	}
798 
799 	/*
800 	 * We must revalidate the buffer after locking.
801 	 */
802 	if ((bp->b_flags & B_DELWRI) == 0 ||
803 	    bp->b_vp != info->vp ||
804 	    info->cmpfunc(bp, data)) {
805 		BUF_UNLOCK(bp);
806 		return(0);
807 	}
808 
809 	/*
810 	 * If syncdeps is not set we do not try to write buffers which have
811 	 * dependancies.
812 	 */
813 	if (!info->synchronous && info->syncdeps == 0 && info->checkdef(bp)) {
814 		BUF_UNLOCK(bp);
815 		return(0);
816 	}
817 
818 	/*
819 	 * B_NEEDCOMMIT (primarily used by NFS) is a state where the buffer
820 	 * has been written but an additional handshake with the device
821 	 * is required before we can dispose of the buffer.  We have no idea
822 	 * how to do this so we have to skip these buffers.
823 	 */
824 	if (bp->b_flags & B_NEEDCOMMIT) {
825 		BUF_UNLOCK(bp);
826 		return(0);
827 	}
828 
829 	/*
830 	 * Ask bioops if it is ok to sync.  If not the VFS may have
831 	 * set B_LOCKED so we have to cycle the buffer.
832 	 */
833 	if (LIST_FIRST(&bp->b_dep) != NULL && buf_checkwrite(bp)) {
834 		bremfree(bp);
835 		brelse(bp);
836 		return(0);
837 	}
838 
839 	if (info->synchronous) {
840 		/*
841 		 * Synchronous flushing.  An error may be returned.
842 		 */
843 		bremfree(bp);
844 		error = bwrite(bp);
845 	} else {
846 		/*
847 		 * Asynchronous flushing.  A negative return value simply
848 		 * stops the scan and is not considered an error.  We use
849 		 * this to support limited MNT_LAZY flushes.
850 		 */
851 		vp->v_lazyw = bp->b_loffset;
852 		bremfree(bp);
853 		info->lazycount += cluster_awrite(bp);
854 		waitrunningbufspace();
855 		vm_wait_nominal();
856 		if (info->lazylimit && info->lazycount >= info->lazylimit)
857 			error = 1;
858 		else
859 			error = 0;
860 	}
861 	return(-error);
862 }
863 
864 /*
865  * Associate a buffer with a vnode.
866  *
867  * MPSAFE
868  */
869 int
870 bgetvp(struct vnode *vp, struct buf *bp, int testsize)
871 {
872 	KASSERT(bp->b_vp == NULL, ("bgetvp: not free"));
873 	KKASSERT((bp->b_flags & (B_HASHED|B_DELWRI|B_VNCLEAN|B_VNDIRTY)) == 0);
874 
875 	/*
876 	 * Insert onto list for new vnode.
877 	 */
878 	lwkt_gettoken(&vp->v_token);
879 
880 	if (buf_rb_hash_RB_INSERT(&vp->v_rbhash_tree, bp)) {
881 		lwkt_reltoken(&vp->v_token);
882 		return (EEXIST);
883 	}
884 
885 	/*
886 	 * Diagnostics (mainly for HAMMER debugging).  Check for
887 	 * overlapping buffers.
888 	 */
889 	if (check_buf_overlap) {
890 		struct buf *bx;
891 		bx = buf_rb_hash_RB_PREV(bp);
892 		if (bx) {
893 			if (bx->b_loffset + bx->b_bufsize > bp->b_loffset) {
894 				kprintf("bgetvp: overlapl %016jx/%d %016jx "
895 					"bx %p bp %p\n",
896 					(intmax_t)bx->b_loffset,
897 					bx->b_bufsize,
898 					(intmax_t)bp->b_loffset,
899 					bx, bp);
900 				if (check_buf_overlap > 1)
901 					panic("bgetvp - overlapping buffer");
902 			}
903 		}
904 		bx = buf_rb_hash_RB_NEXT(bp);
905 		if (bx) {
906 			if (bp->b_loffset + testsize > bx->b_loffset) {
907 				kprintf("bgetvp: overlapr %016jx/%d %016jx "
908 					"bp %p bx %p\n",
909 					(intmax_t)bp->b_loffset,
910 					testsize,
911 					(intmax_t)bx->b_loffset,
912 					bp, bx);
913 				if (check_buf_overlap > 1)
914 					panic("bgetvp - overlapping buffer");
915 			}
916 		}
917 	}
918 	bp->b_vp = vp;
919 	bp->b_flags |= B_HASHED;
920 	bp->b_flags |= B_VNCLEAN;
921 	if (buf_rb_tree_RB_INSERT(&vp->v_rbclean_tree, bp))
922 		panic("reassignbuf: dup lblk/clean vp %p bp %p", vp, bp);
923 	/*vhold(vp);*/
924 	lwkt_reltoken(&vp->v_token);
925 	return(0);
926 }
927 
928 /*
929  * Disassociate a buffer from a vnode.
930  *
931  * MPSAFE
932  */
933 void
934 brelvp(struct buf *bp)
935 {
936 	struct vnode *vp;
937 
938 	KASSERT(bp->b_vp != NULL, ("brelvp: NULL"));
939 
940 	/*
941 	 * Delete from old vnode list, if on one.
942 	 */
943 	vp = bp->b_vp;
944 	lwkt_gettoken(&vp->v_token);
945 	if (bp->b_flags & (B_VNDIRTY | B_VNCLEAN)) {
946 		if (bp->b_flags & B_VNDIRTY)
947 			buf_rb_tree_RB_REMOVE(&vp->v_rbdirty_tree, bp);
948 		else
949 			buf_rb_tree_RB_REMOVE(&vp->v_rbclean_tree, bp);
950 		bp->b_flags &= ~(B_VNDIRTY | B_VNCLEAN);
951 	}
952 	if (bp->b_flags & B_HASHED) {
953 		buf_rb_hash_RB_REMOVE(&vp->v_rbhash_tree, bp);
954 		bp->b_flags &= ~B_HASHED;
955 	}
956 	if ((vp->v_flag & VONWORKLST) && RB_EMPTY(&vp->v_rbdirty_tree))
957 		vn_syncer_remove(vp);
958 	bp->b_vp = NULL;
959 
960 	lwkt_reltoken(&vp->v_token);
961 
962 	/*vdrop(vp);*/
963 }
964 
965 /*
966  * Reassign the buffer to the proper clean/dirty list based on B_DELWRI.
967  * This routine is called when the state of the B_DELWRI bit is changed.
968  *
969  * Must be called with vp->v_token held.
970  * MPSAFE
971  */
972 void
973 reassignbuf(struct buf *bp)
974 {
975 	struct vnode *vp = bp->b_vp;
976 	int delay;
977 
978 	ASSERT_LWKT_TOKEN_HELD(&vp->v_token);
979 	++reassignbufcalls;
980 
981 	/*
982 	 * B_PAGING flagged buffers cannot be reassigned because their vp
983 	 * is not fully linked in.
984 	 */
985 	if (bp->b_flags & B_PAGING)
986 		panic("cannot reassign paging buffer");
987 
988 	if (bp->b_flags & B_DELWRI) {
989 		/*
990 		 * Move to the dirty list, add the vnode to the worklist
991 		 */
992 		if (bp->b_flags & B_VNCLEAN) {
993 			buf_rb_tree_RB_REMOVE(&vp->v_rbclean_tree, bp);
994 			bp->b_flags &= ~B_VNCLEAN;
995 		}
996 		if ((bp->b_flags & B_VNDIRTY) == 0) {
997 			if (buf_rb_tree_RB_INSERT(&vp->v_rbdirty_tree, bp)) {
998 				panic("reassignbuf: dup lblk vp %p bp %p",
999 				      vp, bp);
1000 			}
1001 			bp->b_flags |= B_VNDIRTY;
1002 		}
1003 		if ((vp->v_flag & VONWORKLST) == 0) {
1004 			switch (vp->v_type) {
1005 			case VDIR:
1006 				delay = dirdelay;
1007 				break;
1008 			case VCHR:
1009 			case VBLK:
1010 				if (vp->v_rdev &&
1011 				    vp->v_rdev->si_mountpoint != NULL) {
1012 					delay = metadelay;
1013 					break;
1014 				}
1015 				/* fall through */
1016 			default:
1017 				delay = filedelay;
1018 			}
1019 			vn_syncer_add(vp, delay);
1020 		}
1021 	} else {
1022 		/*
1023 		 * Move to the clean list, remove the vnode from the worklist
1024 		 * if no dirty blocks remain.
1025 		 */
1026 		if (bp->b_flags & B_VNDIRTY) {
1027 			buf_rb_tree_RB_REMOVE(&vp->v_rbdirty_tree, bp);
1028 			bp->b_flags &= ~B_VNDIRTY;
1029 		}
1030 		if ((bp->b_flags & B_VNCLEAN) == 0) {
1031 			if (buf_rb_tree_RB_INSERT(&vp->v_rbclean_tree, bp)) {
1032 				panic("reassignbuf: dup lblk vp %p bp %p",
1033 				      vp, bp);
1034 			}
1035 			bp->b_flags |= B_VNCLEAN;
1036 		}
1037 		if ((vp->v_flag & VONWORKLST) &&
1038 		    RB_EMPTY(&vp->v_rbdirty_tree)) {
1039 			vn_syncer_remove(vp);
1040 		}
1041 	}
1042 }
1043 
1044 /*
1045  * Create a vnode for a block device.  Used for mounting the root file
1046  * system.
1047  *
1048  * A vref()'d vnode is returned.
1049  */
1050 extern struct vop_ops *devfs_vnode_dev_vops_p;
1051 int
1052 bdevvp(cdev_t dev, struct vnode **vpp)
1053 {
1054 	struct vnode *vp;
1055 	struct vnode *nvp;
1056 	int error;
1057 
1058 	if (dev == NULL) {
1059 		*vpp = NULLVP;
1060 		return (ENXIO);
1061 	}
1062 	error = getspecialvnode(VT_NON, NULL, &devfs_vnode_dev_vops_p,
1063 				&nvp, 0, 0);
1064 	if (error) {
1065 		*vpp = NULLVP;
1066 		return (error);
1067 	}
1068 	vp = nvp;
1069 	vp->v_type = VCHR;
1070 #if 0
1071 	vp->v_rdev = dev;
1072 #endif
1073 	v_associate_rdev(vp, dev);
1074 	vp->v_umajor = dev->si_umajor;
1075 	vp->v_uminor = dev->si_uminor;
1076 	vx_unlock(vp);
1077 	*vpp = vp;
1078 	return (0);
1079 }
1080 
1081 int
1082 v_associate_rdev(struct vnode *vp, cdev_t dev)
1083 {
1084 	if (dev == NULL)
1085 		return(ENXIO);
1086 	if (dev_is_good(dev) == 0)
1087 		return(ENXIO);
1088 	KKASSERT(vp->v_rdev == NULL);
1089 	vp->v_rdev = reference_dev(dev);
1090 	lwkt_gettoken(&spechash_token);
1091 	SLIST_INSERT_HEAD(&dev->si_hlist, vp, v_cdevnext);
1092 	lwkt_reltoken(&spechash_token);
1093 	return(0);
1094 }
1095 
1096 void
1097 v_release_rdev(struct vnode *vp)
1098 {
1099 	cdev_t dev;
1100 
1101 	if ((dev = vp->v_rdev) != NULL) {
1102 		lwkt_gettoken(&spechash_token);
1103 		SLIST_REMOVE(&dev->si_hlist, vp, vnode, v_cdevnext);
1104 		vp->v_rdev = NULL;
1105 		release_dev(dev);
1106 		lwkt_reltoken(&spechash_token);
1107 	}
1108 }
1109 
1110 /*
1111  * Add a vnode to the alias list hung off the cdev_t.  We only associate
1112  * the device number with the vnode.  The actual device is not associated
1113  * until the vnode is opened (usually in spec_open()), and will be
1114  * disassociated on last close.
1115  */
1116 void
1117 addaliasu(struct vnode *nvp, int x, int y)
1118 {
1119 	if (nvp->v_type != VBLK && nvp->v_type != VCHR)
1120 		panic("addaliasu on non-special vnode");
1121 	nvp->v_umajor = x;
1122 	nvp->v_uminor = y;
1123 }
1124 
1125 /*
1126  * Simple call that a filesystem can make to try to get rid of a
1127  * vnode.  It will fail if anyone is referencing the vnode (including
1128  * the caller).
1129  *
1130  * The filesystem can check whether its in-memory inode structure still
1131  * references the vp on return.
1132  */
1133 void
1134 vclean_unlocked(struct vnode *vp)
1135 {
1136 	vx_get(vp);
1137 	if (sysref_isactive(&vp->v_sysref) == 0)
1138 		vgone_vxlocked(vp);
1139 	vx_put(vp);
1140 }
1141 
1142 /*
1143  * Disassociate a vnode from its underlying filesystem.
1144  *
1145  * The vnode must be VX locked and referenced.  In all normal situations
1146  * there are no active references.  If vclean_vxlocked() is called while
1147  * there are active references, the vnode is being ripped out and we have
1148  * to call VOP_CLOSE() as appropriate before we can reclaim it.
1149  */
1150 void
1151 vclean_vxlocked(struct vnode *vp, int flags)
1152 {
1153 	int active;
1154 	int n;
1155 	vm_object_t object;
1156 	struct namecache *ncp;
1157 
1158 	/*
1159 	 * If the vnode has already been reclaimed we have nothing to do.
1160 	 */
1161 	if (vp->v_flag & VRECLAIMED)
1162 		return;
1163 	vsetflags(vp, VRECLAIMED);
1164 
1165 	if (verbose_reclaims) {
1166 		if ((ncp = TAILQ_FIRST(&vp->v_namecache)) != NULL)
1167 			kprintf("Debug: reclaim %p %s\n", vp, ncp->nc_name);
1168 	}
1169 
1170 	/*
1171 	 * Scrap the vfs cache
1172 	 */
1173 	while (cache_inval_vp(vp, 0) != 0) {
1174 		kprintf("Warning: vnode %p clean/cache_resolution "
1175 			"race detected\n", vp);
1176 		tsleep(vp, 0, "vclninv", 2);
1177 	}
1178 
1179 	/*
1180 	 * Check to see if the vnode is in use. If so we have to reference it
1181 	 * before we clean it out so that its count cannot fall to zero and
1182 	 * generate a race against ourselves to recycle it.
1183 	 */
1184 	active = sysref_isactive(&vp->v_sysref);
1185 
1186 	/*
1187 	 * Clean out any buffers associated with the vnode and destroy its
1188 	 * object, if it has one.
1189 	 */
1190 	vinvalbuf(vp, V_SAVE, 0, 0);
1191 
1192 	/*
1193 	 * If purging an active vnode (typically during a forced unmount
1194 	 * or reboot), it must be closed and deactivated before being
1195 	 * reclaimed.  This isn't really all that safe, but what can
1196 	 * we do? XXX.
1197 	 *
1198 	 * Note that neither of these routines unlocks the vnode.
1199 	 */
1200 	if (active && (flags & DOCLOSE)) {
1201 		while ((n = vp->v_opencount) != 0) {
1202 			if (vp->v_writecount)
1203 				VOP_CLOSE(vp, FWRITE|FNONBLOCK);
1204 			else
1205 				VOP_CLOSE(vp, FNONBLOCK);
1206 			if (vp->v_opencount == n) {
1207 				kprintf("Warning: unable to force-close"
1208 				       " vnode %p\n", vp);
1209 				break;
1210 			}
1211 		}
1212 	}
1213 
1214 	/*
1215 	 * If the vnode has not been deactivated, deactivated it.  Deactivation
1216 	 * can create new buffers and VM pages so we have to call vinvalbuf()
1217 	 * again to make sure they all get flushed.
1218 	 *
1219 	 * This can occur if a file with a link count of 0 needs to be
1220 	 * truncated.
1221 	 *
1222 	 * If the vnode is already dead don't try to deactivate it.
1223 	 */
1224 	if ((vp->v_flag & VINACTIVE) == 0) {
1225 		vsetflags(vp, VINACTIVE);
1226 		if (vp->v_mount)
1227 			VOP_INACTIVE(vp);
1228 		vinvalbuf(vp, V_SAVE, 0, 0);
1229 	}
1230 
1231 	/*
1232 	 * If the vnode has an object, destroy it.
1233 	 */
1234 	while ((object = vp->v_object) != NULL) {
1235 		vm_object_hold(object);
1236 		if (object == vp->v_object)
1237 			break;
1238 		vm_object_drop(object);
1239 	}
1240 
1241 	if (object != NULL) {
1242 		if (object->ref_count == 0) {
1243 			if ((object->flags & OBJ_DEAD) == 0)
1244 				vm_object_terminate(object);
1245 			vm_object_drop(object);
1246 			vclrflags(vp, VOBJBUF);
1247 		} else {
1248 			vm_pager_deallocate(object);
1249 			vclrflags(vp, VOBJBUF);
1250 			vm_object_drop(object);
1251 		}
1252 	}
1253 	KKASSERT((vp->v_flag & VOBJBUF) == 0);
1254 
1255 	/*
1256 	 * Reclaim the vnode if not already dead.
1257 	 */
1258 	if (vp->v_mount && VOP_RECLAIM(vp))
1259 		panic("vclean: cannot reclaim");
1260 
1261 	/*
1262 	 * Done with purge, notify sleepers of the grim news.
1263 	 */
1264 	vp->v_ops = &dead_vnode_vops_p;
1265 	vn_gone(vp);
1266 	vp->v_tag = VT_NON;
1267 
1268 	/*
1269 	 * If we are destroying an active vnode, reactivate it now that
1270 	 * we have reassociated it with deadfs.  This prevents the system
1271 	 * from crashing on the vnode due to it being unexpectedly marked
1272 	 * as inactive or reclaimed.
1273 	 */
1274 	if (active && (flags & DOCLOSE)) {
1275 		vclrflags(vp, VINACTIVE | VRECLAIMED);
1276 	}
1277 }
1278 
1279 /*
1280  * Eliminate all activity associated with the requested vnode
1281  * and with all vnodes aliased to the requested vnode.
1282  *
1283  * The vnode must be referenced but should not be locked.
1284  */
1285 int
1286 vrevoke(struct vnode *vp, struct ucred *cred)
1287 {
1288 	struct vnode *vq;
1289 	struct vnode *vqn;
1290 	cdev_t dev;
1291 	int error;
1292 
1293 	/*
1294 	 * If the vnode has a device association, scrap all vnodes associated
1295 	 * with the device.  Don't let the device disappear on us while we
1296 	 * are scrapping the vnodes.
1297 	 *
1298 	 * The passed vp will probably show up in the list, do not VX lock
1299 	 * it twice!
1300 	 *
1301 	 * Releasing the vnode's rdev here can mess up specfs's call to
1302 	 * device close, so don't do it.  The vnode has been disassociated
1303 	 * and the device will be closed after the last ref on the related
1304 	 * fp goes away (if not still open by e.g. the kernel).
1305 	 */
1306 	if (vp->v_type != VCHR) {
1307 		error = fdrevoke(vp, DTYPE_VNODE, cred);
1308 		return (error);
1309 	}
1310 	if ((dev = vp->v_rdev) == NULL) {
1311 		return(0);
1312 	}
1313 	reference_dev(dev);
1314 	lwkt_gettoken(&spechash_token);
1315 
1316 restart:
1317 	vqn = SLIST_FIRST(&dev->si_hlist);
1318 	if (vqn)
1319 		vhold(vqn);
1320 	while ((vq = vqn) != NULL) {
1321 		if (sysref_isactive(&vq->v_sysref)) {
1322 			vref(vq);
1323 			fdrevoke(vq, DTYPE_VNODE, cred);
1324 			/*v_release_rdev(vq);*/
1325 			vrele(vq);
1326 			if (vq->v_rdev != dev) {
1327 				vdrop(vq);
1328 				goto restart;
1329 			}
1330 		}
1331 		vqn = SLIST_NEXT(vq, v_cdevnext);
1332 		if (vqn)
1333 			vhold(vqn);
1334 		vdrop(vq);
1335 	}
1336 	lwkt_reltoken(&spechash_token);
1337 	dev_drevoke(dev);
1338 	release_dev(dev);
1339 	return (0);
1340 }
1341 
1342 /*
1343  * This is called when the object underlying a vnode is being destroyed,
1344  * such as in a remove().  Try to recycle the vnode immediately if the
1345  * only active reference is our reference.
1346  *
1347  * Directory vnodes in the namecache with children cannot be immediately
1348  * recycled because numerous VOP_N*() ops require them to be stable.
1349  *
1350  * To avoid recursive recycling from VOP_INACTIVE implemenetations this
1351  * function is a NOP if VRECLAIMED is already set.
1352  */
1353 int
1354 vrecycle(struct vnode *vp)
1355 {
1356 	if (vp->v_sysref.refcnt <= 1 && (vp->v_flag & VRECLAIMED) == 0) {
1357 		if (cache_inval_vp_nonblock(vp))
1358 			return(0);
1359 		vgone_vxlocked(vp);
1360 		return (1);
1361 	}
1362 	return (0);
1363 }
1364 
1365 /*
1366  * Return the maximum I/O size allowed for strategy calls on VP.
1367  *
1368  * If vp is VCHR or VBLK we dive the device, otherwise we use
1369  * the vp's mount info.
1370  *
1371  * The returned value is clamped at MAXPHYS as most callers cannot use
1372  * buffers larger than that size.
1373  */
1374 int
1375 vmaxiosize(struct vnode *vp)
1376 {
1377 	int maxiosize;
1378 
1379 	if (vp->v_type == VBLK || vp->v_type == VCHR)
1380 		maxiosize = vp->v_rdev->si_iosize_max;
1381 	else
1382 		maxiosize = vp->v_mount->mnt_iosize_max;
1383 
1384 	if (maxiosize > MAXPHYS)
1385 		maxiosize = MAXPHYS;
1386 	return (maxiosize);
1387 }
1388 
1389 /*
1390  * Eliminate all activity associated with a vnode in preparation for reuse.
1391  *
1392  * The vnode must be VX locked and refd and will remain VX locked and refd
1393  * on return.  This routine may be called with the vnode in any state, as
1394  * long as it is VX locked.  The vnode will be cleaned out and marked
1395  * VRECLAIMED but will not actually be reused until all existing refs and
1396  * holds go away.
1397  *
1398  * NOTE: This routine may be called on a vnode which has not yet been
1399  * already been deactivated (VOP_INACTIVE), or on a vnode which has
1400  * already been reclaimed.
1401  *
1402  * This routine is not responsible for placing us back on the freelist.
1403  * Instead, it happens automatically when the caller releases the VX lock
1404  * (assuming there aren't any other references).
1405  */
1406 void
1407 vgone_vxlocked(struct vnode *vp)
1408 {
1409 	/*
1410 	 * assert that the VX lock is held.  This is an absolute requirement
1411 	 * now for vgone_vxlocked() to be called.
1412 	 */
1413 	KKASSERT(vp->v_lock.lk_exclusivecount == 1);
1414 
1415 	/*
1416 	 * Clean out the filesystem specific data and set the VRECLAIMED
1417 	 * bit.  Also deactivate the vnode if necessary.
1418 	 */
1419 	vclean_vxlocked(vp, DOCLOSE);
1420 
1421 	/*
1422 	 * Delete from old mount point vnode list, if on one.
1423 	 */
1424 	if (vp->v_mount != NULL) {
1425 		KKASSERT(vp->v_data == NULL);
1426 		insmntque(vp, NULL);
1427 	}
1428 
1429 	/*
1430 	 * If special device, remove it from special device alias list
1431 	 * if it is on one.  This should normally only occur if a vnode is
1432 	 * being revoked as the device should otherwise have been released
1433 	 * naturally.
1434 	 */
1435 	if ((vp->v_type == VBLK || vp->v_type == VCHR) && vp->v_rdev != NULL) {
1436 		v_release_rdev(vp);
1437 	}
1438 
1439 	/*
1440 	 * Set us to VBAD
1441 	 */
1442 	vp->v_type = VBAD;
1443 }
1444 
1445 /*
1446  * Lookup a vnode by device number.
1447  *
1448  * Returns non-zero and *vpp set to a vref'd vnode on success.
1449  * Returns zero on failure.
1450  */
1451 int
1452 vfinddev(cdev_t dev, enum vtype type, struct vnode **vpp)
1453 {
1454 	struct vnode *vp;
1455 
1456 	lwkt_gettoken(&spechash_token);
1457 	SLIST_FOREACH(vp, &dev->si_hlist, v_cdevnext) {
1458 		if (type == vp->v_type) {
1459 			*vpp = vp;
1460 			vref(vp);
1461 			lwkt_reltoken(&spechash_token);
1462 			return (1);
1463 		}
1464 	}
1465 	lwkt_reltoken(&spechash_token);
1466 	return (0);
1467 }
1468 
1469 /*
1470  * Calculate the total number of references to a special device.  This
1471  * routine may only be called for VBLK and VCHR vnodes since v_rdev is
1472  * an overloaded field.  Since udev2dev can now return NULL, we have
1473  * to check for a NULL v_rdev.
1474  */
1475 int
1476 count_dev(cdev_t dev)
1477 {
1478 	struct vnode *vp;
1479 	int count = 0;
1480 
1481 	if (SLIST_FIRST(&dev->si_hlist)) {
1482 		lwkt_gettoken(&spechash_token);
1483 		SLIST_FOREACH(vp, &dev->si_hlist, v_cdevnext) {
1484 			count += vp->v_opencount;
1485 		}
1486 		lwkt_reltoken(&spechash_token);
1487 	}
1488 	return(count);
1489 }
1490 
1491 int
1492 vcount(struct vnode *vp)
1493 {
1494 	if (vp->v_rdev == NULL)
1495 		return(0);
1496 	return(count_dev(vp->v_rdev));
1497 }
1498 
1499 /*
1500  * Initialize VMIO for a vnode.  This routine MUST be called before a
1501  * VFS can issue buffer cache ops on a vnode.  It is typically called
1502  * when a vnode is initialized from its inode.
1503  */
1504 int
1505 vinitvmio(struct vnode *vp, off_t filesize, int blksize, int boff)
1506 {
1507 	vm_object_t object;
1508 	int error = 0;
1509 
1510 retry:
1511 	while ((object = vp->v_object) != NULL) {
1512 		vm_object_hold(object);
1513 		if (object == vp->v_object)
1514 			break;
1515 		vm_object_drop(object);
1516 	}
1517 
1518 	if (object == NULL) {
1519 		object = vnode_pager_alloc(vp, filesize, 0, 0, blksize, boff);
1520 
1521 		/*
1522 		 * Dereference the reference we just created.  This assumes
1523 		 * that the object is associated with the vp.
1524 		 */
1525 		vm_object_hold(object);
1526 		object->ref_count--;
1527 		vrele(vp);
1528 	} else {
1529 		if (object->flags & OBJ_DEAD) {
1530 			vn_unlock(vp);
1531 			if (vp->v_object == object)
1532 				vm_object_dead_sleep(object, "vodead");
1533 			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1534 			vm_object_drop(object);
1535 			goto retry;
1536 		}
1537 	}
1538 	KASSERT(vp->v_object != NULL, ("vinitvmio: NULL object"));
1539 	vsetflags(vp, VOBJBUF);
1540 	vm_object_drop(object);
1541 
1542 	return (error);
1543 }
1544 
1545 
1546 /*
1547  * Print out a description of a vnode.
1548  */
1549 static char *typename[] =
1550 {"VNON", "VREG", "VDIR", "VBLK", "VCHR", "VLNK", "VSOCK", "VFIFO", "VBAD"};
1551 
1552 void
1553 vprint(char *label, struct vnode *vp)
1554 {
1555 	char buf[96];
1556 
1557 	if (label != NULL)
1558 		kprintf("%s: %p: ", label, (void *)vp);
1559 	else
1560 		kprintf("%p: ", (void *)vp);
1561 	kprintf("type %s, sysrefs %d, writecount %d, holdcnt %d,",
1562 		typename[vp->v_type],
1563 		vp->v_sysref.refcnt, vp->v_writecount, vp->v_auxrefs);
1564 	buf[0] = '\0';
1565 	if (vp->v_flag & VROOT)
1566 		strcat(buf, "|VROOT");
1567 	if (vp->v_flag & VPFSROOT)
1568 		strcat(buf, "|VPFSROOT");
1569 	if (vp->v_flag & VTEXT)
1570 		strcat(buf, "|VTEXT");
1571 	if (vp->v_flag & VSYSTEM)
1572 		strcat(buf, "|VSYSTEM");
1573 	if (vp->v_flag & VFREE)
1574 		strcat(buf, "|VFREE");
1575 	if (vp->v_flag & VOBJBUF)
1576 		strcat(buf, "|VOBJBUF");
1577 	if (buf[0] != '\0')
1578 		kprintf(" flags (%s)", &buf[1]);
1579 	if (vp->v_data == NULL) {
1580 		kprintf("\n");
1581 	} else {
1582 		kprintf("\n\t");
1583 		VOP_PRINT(vp);
1584 	}
1585 }
1586 
1587 /*
1588  * Do the usual access checking.
1589  * file_mode, uid and gid are from the vnode in question,
1590  * while acc_mode and cred are from the VOP_ACCESS parameter list
1591  */
1592 int
1593 vaccess(enum vtype type, mode_t file_mode, uid_t uid, gid_t gid,
1594     mode_t acc_mode, struct ucred *cred)
1595 {
1596 	mode_t mask;
1597 	int ismember;
1598 
1599 	/*
1600 	 * Super-user always gets read/write access, but execute access depends
1601 	 * on at least one execute bit being set.
1602 	 */
1603 	if (priv_check_cred(cred, PRIV_ROOT, 0) == 0) {
1604 		if ((acc_mode & VEXEC) && type != VDIR &&
1605 		    (file_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)
1606 			return (EACCES);
1607 		return (0);
1608 	}
1609 
1610 	mask = 0;
1611 
1612 	/* Otherwise, check the owner. */
1613 	if (cred->cr_uid == uid) {
1614 		if (acc_mode & VEXEC)
1615 			mask |= S_IXUSR;
1616 		if (acc_mode & VREAD)
1617 			mask |= S_IRUSR;
1618 		if (acc_mode & VWRITE)
1619 			mask |= S_IWUSR;
1620 		return ((file_mode & mask) == mask ? 0 : EACCES);
1621 	}
1622 
1623 	/* Otherwise, check the groups. */
1624 	ismember = groupmember(gid, cred);
1625 	if (cred->cr_svgid == gid || ismember) {
1626 		if (acc_mode & VEXEC)
1627 			mask |= S_IXGRP;
1628 		if (acc_mode & VREAD)
1629 			mask |= S_IRGRP;
1630 		if (acc_mode & VWRITE)
1631 			mask |= S_IWGRP;
1632 		return ((file_mode & mask) == mask ? 0 : EACCES);
1633 	}
1634 
1635 	/* Otherwise, check everyone else. */
1636 	if (acc_mode & VEXEC)
1637 		mask |= S_IXOTH;
1638 	if (acc_mode & VREAD)
1639 		mask |= S_IROTH;
1640 	if (acc_mode & VWRITE)
1641 		mask |= S_IWOTH;
1642 	return ((file_mode & mask) == mask ? 0 : EACCES);
1643 }
1644 
1645 #ifdef DDB
1646 #include <ddb/ddb.h>
1647 
1648 static int db_show_locked_vnodes(struct mount *mp, void *data);
1649 
1650 /*
1651  * List all of the locked vnodes in the system.
1652  * Called when debugging the kernel.
1653  */
1654 DB_SHOW_COMMAND(lockedvnodes, lockedvnodes)
1655 {
1656 	kprintf("Locked vnodes\n");
1657 	mountlist_scan(db_show_locked_vnodes, NULL,
1658 			MNTSCAN_FORWARD|MNTSCAN_NOBUSY);
1659 }
1660 
1661 static int
1662 db_show_locked_vnodes(struct mount *mp, void *data __unused)
1663 {
1664 	struct vnode *vp;
1665 
1666 	TAILQ_FOREACH(vp, &mp->mnt_nvnodelist, v_nmntvnodes) {
1667 		if (vn_islocked(vp))
1668 			vprint(NULL, vp);
1669 	}
1670 	return(0);
1671 }
1672 #endif
1673 
1674 /*
1675  * Top level filesystem related information gathering.
1676  */
1677 static int	sysctl_ovfs_conf (SYSCTL_HANDLER_ARGS);
1678 
1679 static int
1680 vfs_sysctl(SYSCTL_HANDLER_ARGS)
1681 {
1682 	int *name = (int *)arg1 - 1;	/* XXX */
1683 	u_int namelen = arg2 + 1;	/* XXX */
1684 	struct vfsconf *vfsp;
1685 	int maxtypenum;
1686 
1687 #if 1 || defined(COMPAT_PRELITE2)
1688 	/* Resolve ambiguity between VFS_VFSCONF and VFS_GENERIC. */
1689 	if (namelen == 1)
1690 		return (sysctl_ovfs_conf(oidp, arg1, arg2, req));
1691 #endif
1692 
1693 #ifdef notyet
1694 	/* all sysctl names at this level are at least name and field */
1695 	if (namelen < 2)
1696 		return (ENOTDIR);		/* overloaded */
1697 	if (name[0] != VFS_GENERIC) {
1698 		vfsp = vfsconf_find_by_typenum(name[0]);
1699 		if (vfsp == NULL)
1700 			return (EOPNOTSUPP);
1701 		return ((*vfsp->vfc_vfsops->vfs_sysctl)(&name[1], namelen - 1,
1702 		    oldp, oldlenp, newp, newlen, p));
1703 	}
1704 #endif
1705 	switch (name[1]) {
1706 	case VFS_MAXTYPENUM:
1707 		if (namelen != 2)
1708 			return (ENOTDIR);
1709 		maxtypenum = vfsconf_get_maxtypenum();
1710 		return (SYSCTL_OUT(req, &maxtypenum, sizeof(maxtypenum)));
1711 	case VFS_CONF:
1712 		if (namelen != 3)
1713 			return (ENOTDIR);	/* overloaded */
1714 		vfsp = vfsconf_find_by_typenum(name[2]);
1715 		if (vfsp == NULL)
1716 			return (EOPNOTSUPP);
1717 		return (SYSCTL_OUT(req, vfsp, sizeof *vfsp));
1718 	}
1719 	return (EOPNOTSUPP);
1720 }
1721 
1722 SYSCTL_NODE(_vfs, VFS_GENERIC, generic, CTLFLAG_RD, vfs_sysctl,
1723 	"Generic filesystem");
1724 
1725 #if 1 || defined(COMPAT_PRELITE2)
1726 
1727 static int
1728 sysctl_ovfs_conf_iter(struct vfsconf *vfsp, void *data)
1729 {
1730 	int error;
1731 	struct ovfsconf ovfs;
1732 	struct sysctl_req *req = (struct sysctl_req*) data;
1733 
1734 	bzero(&ovfs, sizeof(ovfs));
1735 	ovfs.vfc_vfsops = vfsp->vfc_vfsops;	/* XXX used as flag */
1736 	strcpy(ovfs.vfc_name, vfsp->vfc_name);
1737 	ovfs.vfc_index = vfsp->vfc_typenum;
1738 	ovfs.vfc_refcount = vfsp->vfc_refcount;
1739 	ovfs.vfc_flags = vfsp->vfc_flags;
1740 	error = SYSCTL_OUT(req, &ovfs, sizeof ovfs);
1741 	if (error)
1742 		return error; /* abort iteration with error code */
1743 	else
1744 		return 0; /* continue iterating with next element */
1745 }
1746 
1747 static int
1748 sysctl_ovfs_conf(SYSCTL_HANDLER_ARGS)
1749 {
1750 	return vfsconf_each(sysctl_ovfs_conf_iter, (void*)req);
1751 }
1752 
1753 #endif /* 1 || COMPAT_PRELITE2 */
1754 
1755 /*
1756  * Check to see if a filesystem is mounted on a block device.
1757  */
1758 int
1759 vfs_mountedon(struct vnode *vp)
1760 {
1761 	cdev_t dev;
1762 
1763 	if ((dev = vp->v_rdev) == NULL) {
1764 /*		if (vp->v_type != VBLK)
1765 			dev = get_dev(vp->v_uminor, vp->v_umajor); */
1766 	}
1767 	if (dev != NULL && dev->si_mountpoint)
1768 		return (EBUSY);
1769 	return (0);
1770 }
1771 
1772 /*
1773  * Unmount all filesystems. The list is traversed in reverse order
1774  * of mounting to avoid dependencies.
1775  */
1776 
1777 static int vfs_umountall_callback(struct mount *mp, void *data);
1778 
1779 void
1780 vfs_unmountall(void)
1781 {
1782 	int count;
1783 
1784 	do {
1785 		count = mountlist_scan(vfs_umountall_callback,
1786 					NULL, MNTSCAN_REVERSE|MNTSCAN_NOBUSY);
1787 	} while (count);
1788 }
1789 
1790 static
1791 int
1792 vfs_umountall_callback(struct mount *mp, void *data)
1793 {
1794 	int error;
1795 
1796 	error = dounmount(mp, MNT_FORCE);
1797 	if (error) {
1798 		mountlist_remove(mp);
1799 		kprintf("unmount of filesystem mounted from %s failed (",
1800 			mp->mnt_stat.f_mntfromname);
1801 		if (error == EBUSY)
1802 			kprintf("BUSY)\n");
1803 		else
1804 			kprintf("%d)\n", error);
1805 	}
1806 	return(1);
1807 }
1808 
1809 /*
1810  * Checks the mount flags for parameter mp and put the names comma-separated
1811  * into a string buffer buf with a size limit specified by len.
1812  *
1813  * It returns the number of bytes written into buf, and (*errorp) will be
1814  * set to 0, EINVAL (if passed length is 0), or ENOSPC (supplied buffer was
1815  * not large enough).  The buffer will be 0-terminated if len was not 0.
1816  */
1817 size_t
1818 vfs_flagstostr(int flags, const struct mountctl_opt *optp,
1819 	       char *buf, size_t len, int *errorp)
1820 {
1821 	static const struct mountctl_opt optnames[] = {
1822 		{ MNT_ASYNC,            "asynchronous" },
1823 		{ MNT_EXPORTED,         "NFS exported" },
1824 		{ MNT_LOCAL,            "local" },
1825 		{ MNT_NOATIME,          "noatime" },
1826 		{ MNT_NODEV,            "nodev" },
1827 		{ MNT_NOEXEC,           "noexec" },
1828 		{ MNT_NOSUID,           "nosuid" },
1829 		{ MNT_NOSYMFOLLOW,      "nosymfollow" },
1830 		{ MNT_QUOTA,            "with-quotas" },
1831 		{ MNT_RDONLY,           "read-only" },
1832 		{ MNT_SYNCHRONOUS,      "synchronous" },
1833 		{ MNT_UNION,            "union" },
1834 		{ MNT_NOCLUSTERR,       "noclusterr" },
1835 		{ MNT_NOCLUSTERW,       "noclusterw" },
1836 		{ MNT_SUIDDIR,          "suiddir" },
1837 		{ MNT_SOFTDEP,          "soft-updates" },
1838 		{ MNT_IGNORE,           "ignore" },
1839 		{ 0,			NULL}
1840 	};
1841 	int bwritten;
1842 	int bleft;
1843 	int optlen;
1844 	int actsize;
1845 
1846 	*errorp = 0;
1847 	bwritten = 0;
1848 	bleft = len - 1;	/* leave room for trailing \0 */
1849 
1850 	/*
1851 	 * Checks the size of the string. If it contains
1852 	 * any data, then we will append the new flags to
1853 	 * it.
1854 	 */
1855 	actsize = strlen(buf);
1856 	if (actsize > 0)
1857 		buf += actsize;
1858 
1859 	/* Default flags if no flags passed */
1860 	if (optp == NULL)
1861 		optp = optnames;
1862 
1863 	if (bleft < 0) {	/* degenerate case, 0-length buffer */
1864 		*errorp = EINVAL;
1865 		return(0);
1866 	}
1867 
1868 	for (; flags && optp->o_opt; ++optp) {
1869 		if ((flags & optp->o_opt) == 0)
1870 			continue;
1871 		optlen = strlen(optp->o_name);
1872 		if (bwritten || actsize > 0) {
1873 			if (bleft < 2) {
1874 				*errorp = ENOSPC;
1875 				break;
1876 			}
1877 			buf[bwritten++] = ',';
1878 			buf[bwritten++] = ' ';
1879 			bleft -= 2;
1880 		}
1881 		if (bleft < optlen) {
1882 			*errorp = ENOSPC;
1883 			break;
1884 		}
1885 		bcopy(optp->o_name, buf + bwritten, optlen);
1886 		bwritten += optlen;
1887 		bleft -= optlen;
1888 		flags &= ~optp->o_opt;
1889 	}
1890 
1891 	/*
1892 	 * Space already reserved for trailing \0
1893 	 */
1894 	buf[bwritten] = 0;
1895 	return (bwritten);
1896 }
1897 
1898 /*
1899  * Build hash lists of net addresses and hang them off the mount point.
1900  * Called by ufs_mount() to set up the lists of export addresses.
1901  */
1902 static int
1903 vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
1904 		const struct export_args *argp)
1905 {
1906 	struct netcred *np;
1907 	struct radix_node_head *rnh;
1908 	int i;
1909 	struct radix_node *rn;
1910 	struct sockaddr *saddr, *smask = NULL;
1911 	struct domain *dom;
1912 	int error;
1913 
1914 	if (argp->ex_addrlen == 0) {
1915 		if (mp->mnt_flag & MNT_DEFEXPORTED)
1916 			return (EPERM);
1917 		np = &nep->ne_defexported;
1918 		np->netc_exflags = argp->ex_flags;
1919 		np->netc_anon = argp->ex_anon;
1920 		np->netc_anon.cr_ref = 1;
1921 		mp->mnt_flag |= MNT_DEFEXPORTED;
1922 		return (0);
1923 	}
1924 
1925 	if (argp->ex_addrlen < 0 || argp->ex_addrlen > MLEN)
1926 		return (EINVAL);
1927 	if (argp->ex_masklen < 0 || argp->ex_masklen > MLEN)
1928 		return (EINVAL);
1929 
1930 	i = sizeof(struct netcred) + argp->ex_addrlen + argp->ex_masklen;
1931 	np = (struct netcred *) kmalloc(i, M_NETADDR, M_WAITOK | M_ZERO);
1932 	saddr = (struct sockaddr *) (np + 1);
1933 	if ((error = copyin(argp->ex_addr, (caddr_t) saddr, argp->ex_addrlen)))
1934 		goto out;
1935 	if (saddr->sa_len > argp->ex_addrlen)
1936 		saddr->sa_len = argp->ex_addrlen;
1937 	if (argp->ex_masklen) {
1938 		smask = (struct sockaddr *)((caddr_t)saddr + argp->ex_addrlen);
1939 		error = copyin(argp->ex_mask, (caddr_t)smask, argp->ex_masklen);
1940 		if (error)
1941 			goto out;
1942 		if (smask->sa_len > argp->ex_masklen)
1943 			smask->sa_len = argp->ex_masklen;
1944 	}
1945 	i = saddr->sa_family;
1946 	if ((rnh = nep->ne_rtable[i]) == NULL) {
1947 		/*
1948 		 * Seems silly to initialize every AF when most are not used,
1949 		 * do so on demand here
1950 		 */
1951 		SLIST_FOREACH(dom, &domains, dom_next)
1952 			if (dom->dom_family == i && dom->dom_rtattach) {
1953 				dom->dom_rtattach((void **) &nep->ne_rtable[i],
1954 				    dom->dom_rtoffset);
1955 				break;
1956 			}
1957 		if ((rnh = nep->ne_rtable[i]) == NULL) {
1958 			error = ENOBUFS;
1959 			goto out;
1960 		}
1961 	}
1962 	rn = (*rnh->rnh_addaddr) ((char *) saddr, (char *) smask, rnh,
1963 	    np->netc_rnodes);
1964 	if (rn == NULL || np != (struct netcred *) rn) {	/* already exists */
1965 		error = EPERM;
1966 		goto out;
1967 	}
1968 	np->netc_exflags = argp->ex_flags;
1969 	np->netc_anon = argp->ex_anon;
1970 	np->netc_anon.cr_ref = 1;
1971 	return (0);
1972 out:
1973 	kfree(np, M_NETADDR);
1974 	return (error);
1975 }
1976 
1977 /* ARGSUSED */
1978 static int
1979 vfs_free_netcred(struct radix_node *rn, void *w)
1980 {
1981 	struct radix_node_head *rnh = (struct radix_node_head *) w;
1982 
1983 	(*rnh->rnh_deladdr) (rn->rn_key, rn->rn_mask, rnh);
1984 	kfree((caddr_t) rn, M_NETADDR);
1985 	return (0);
1986 }
1987 
1988 /*
1989  * Free the net address hash lists that are hanging off the mount points.
1990  */
1991 static void
1992 vfs_free_addrlist(struct netexport *nep)
1993 {
1994 	int i;
1995 	struct radix_node_head *rnh;
1996 
1997 	for (i = 0; i <= AF_MAX; i++)
1998 		if ((rnh = nep->ne_rtable[i])) {
1999 			(*rnh->rnh_walktree) (rnh, vfs_free_netcred,
2000 			    (caddr_t) rnh);
2001 			kfree((caddr_t) rnh, M_RTABLE);
2002 			nep->ne_rtable[i] = 0;
2003 		}
2004 }
2005 
2006 int
2007 vfs_export(struct mount *mp, struct netexport *nep,
2008 	   const struct export_args *argp)
2009 {
2010 	int error;
2011 
2012 	if (argp->ex_flags & MNT_DELEXPORT) {
2013 		if (mp->mnt_flag & MNT_EXPUBLIC) {
2014 			vfs_setpublicfs(NULL, NULL, NULL);
2015 			mp->mnt_flag &= ~MNT_EXPUBLIC;
2016 		}
2017 		vfs_free_addrlist(nep);
2018 		mp->mnt_flag &= ~(MNT_EXPORTED | MNT_DEFEXPORTED);
2019 	}
2020 	if (argp->ex_flags & MNT_EXPORTED) {
2021 		if (argp->ex_flags & MNT_EXPUBLIC) {
2022 			if ((error = vfs_setpublicfs(mp, nep, argp)) != 0)
2023 				return (error);
2024 			mp->mnt_flag |= MNT_EXPUBLIC;
2025 		}
2026 		if ((error = vfs_hang_addrlist(mp, nep, argp)))
2027 			return (error);
2028 		mp->mnt_flag |= MNT_EXPORTED;
2029 	}
2030 	return (0);
2031 }
2032 
2033 
2034 /*
2035  * Set the publicly exported filesystem (WebNFS). Currently, only
2036  * one public filesystem is possible in the spec (RFC 2054 and 2055)
2037  */
2038 int
2039 vfs_setpublicfs(struct mount *mp, struct netexport *nep,
2040 		const struct export_args *argp)
2041 {
2042 	int error;
2043 	struct vnode *rvp;
2044 	char *cp;
2045 
2046 	/*
2047 	 * mp == NULL -> invalidate the current info, the FS is
2048 	 * no longer exported. May be called from either vfs_export
2049 	 * or unmount, so check if it hasn't already been done.
2050 	 */
2051 	if (mp == NULL) {
2052 		if (nfs_pub.np_valid) {
2053 			nfs_pub.np_valid = 0;
2054 			if (nfs_pub.np_index != NULL) {
2055 				kfree(nfs_pub.np_index, M_TEMP);
2056 				nfs_pub.np_index = NULL;
2057 			}
2058 		}
2059 		return (0);
2060 	}
2061 
2062 	/*
2063 	 * Only one allowed at a time.
2064 	 */
2065 	if (nfs_pub.np_valid != 0 && mp != nfs_pub.np_mount)
2066 		return (EBUSY);
2067 
2068 	/*
2069 	 * Get real filehandle for root of exported FS.
2070 	 */
2071 	bzero((caddr_t)&nfs_pub.np_handle, sizeof(nfs_pub.np_handle));
2072 	nfs_pub.np_handle.fh_fsid = mp->mnt_stat.f_fsid;
2073 
2074 	if ((error = VFS_ROOT(mp, &rvp)))
2075 		return (error);
2076 
2077 	if ((error = VFS_VPTOFH(rvp, &nfs_pub.np_handle.fh_fid)))
2078 		return (error);
2079 
2080 	vput(rvp);
2081 
2082 	/*
2083 	 * If an indexfile was specified, pull it in.
2084 	 */
2085 	if (argp->ex_indexfile != NULL) {
2086 		int namelen;
2087 
2088 		error = vn_get_namelen(rvp, &namelen);
2089 		if (error)
2090 			return (error);
2091 		nfs_pub.np_index = kmalloc(namelen, M_TEMP, M_WAITOK);
2092 		error = copyinstr(argp->ex_indexfile, nfs_pub.np_index,
2093 		    namelen, NULL);
2094 		if (!error) {
2095 			/*
2096 			 * Check for illegal filenames.
2097 			 */
2098 			for (cp = nfs_pub.np_index; *cp; cp++) {
2099 				if (*cp == '/') {
2100 					error = EINVAL;
2101 					break;
2102 				}
2103 			}
2104 		}
2105 		if (error) {
2106 			kfree(nfs_pub.np_index, M_TEMP);
2107 			return (error);
2108 		}
2109 	}
2110 
2111 	nfs_pub.np_mount = mp;
2112 	nfs_pub.np_valid = 1;
2113 	return (0);
2114 }
2115 
2116 struct netcred *
2117 vfs_export_lookup(struct mount *mp, struct netexport *nep,
2118 		struct sockaddr *nam)
2119 {
2120 	struct netcred *np;
2121 	struct radix_node_head *rnh;
2122 	struct sockaddr *saddr;
2123 
2124 	np = NULL;
2125 	if (mp->mnt_flag & MNT_EXPORTED) {
2126 		/*
2127 		 * Lookup in the export list first.
2128 		 */
2129 		if (nam != NULL) {
2130 			saddr = nam;
2131 			rnh = nep->ne_rtable[saddr->sa_family];
2132 			if (rnh != NULL) {
2133 				np = (struct netcred *)
2134 					(*rnh->rnh_matchaddr)((char *)saddr,
2135 							      rnh);
2136 				if (np && np->netc_rnodes->rn_flags & RNF_ROOT)
2137 					np = NULL;
2138 			}
2139 		}
2140 		/*
2141 		 * If no address match, use the default if it exists.
2142 		 */
2143 		if (np == NULL && mp->mnt_flag & MNT_DEFEXPORTED)
2144 			np = &nep->ne_defexported;
2145 	}
2146 	return (np);
2147 }
2148 
2149 /*
2150  * perform msync on all vnodes under a mount point.  The mount point must
2151  * be locked.  This code is also responsible for lazy-freeing unreferenced
2152  * vnodes whos VM objects no longer contain pages.
2153  *
2154  * NOTE: MNT_WAIT still skips vnodes in the VXLOCK state.
2155  *
2156  * NOTE: XXX VOP_PUTPAGES and friends requires that the vnode be locked,
2157  * but vnode_pager_putpages() doesn't lock the vnode.  We have to do it
2158  * way up in this high level function.
2159  */
2160 static int vfs_msync_scan1(struct mount *mp, struct vnode *vp, void *data);
2161 static int vfs_msync_scan2(struct mount *mp, struct vnode *vp, void *data);
2162 
2163 void
2164 vfs_msync(struct mount *mp, int flags)
2165 {
2166 	int vmsc_flags;
2167 
2168 	/*
2169 	 * tmpfs sets this flag to prevent msync(), sync, and the
2170 	 * filesystem periodic syncer from trying to flush VM pages
2171 	 * to swap.  Only pure memory pressure flushes tmpfs VM pages
2172 	 * to swap.
2173 	 */
2174 	if (mp->mnt_kern_flag & MNTK_NOMSYNC)
2175 		return;
2176 
2177 	/*
2178 	 * Ok, scan the vnodes for work.
2179 	 */
2180 	vmsc_flags = VMSC_GETVP;
2181 	if (flags != MNT_WAIT)
2182 		vmsc_flags |= VMSC_NOWAIT;
2183 	vmntvnodescan(mp, vmsc_flags,
2184 		      vfs_msync_scan1, vfs_msync_scan2,
2185 		      (void *)(intptr_t)flags);
2186 }
2187 
2188 /*
2189  * scan1 is a fast pre-check.  There could be hundreds of thousands of
2190  * vnodes, we cannot afford to do anything heavy weight until we have a
2191  * fairly good indication that there is work to do.
2192  */
2193 static
2194 int
2195 vfs_msync_scan1(struct mount *mp, struct vnode *vp, void *data)
2196 {
2197 	int flags = (int)(intptr_t)data;
2198 
2199 	if ((vp->v_flag & VRECLAIMED) == 0) {
2200 		if (vshouldmsync(vp))
2201 			return(0);	/* call scan2 */
2202 		if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
2203 		    (vp->v_flag & VOBJDIRTY) &&
2204 		    (flags == MNT_WAIT || vn_islocked(vp) == 0)) {
2205 			return(0);	/* call scan2 */
2206 		}
2207 	}
2208 
2209 	/*
2210 	 * do not call scan2, continue the loop
2211 	 */
2212 	return(-1);
2213 }
2214 
2215 /*
2216  * This callback is handed a locked vnode.
2217  */
2218 static
2219 int
2220 vfs_msync_scan2(struct mount *mp, struct vnode *vp, void *data)
2221 {
2222 	vm_object_t obj;
2223 	int flags = (int)(intptr_t)data;
2224 
2225 	if (vp->v_flag & VRECLAIMED)
2226 		return(0);
2227 
2228 	if ((mp->mnt_flag & MNT_RDONLY) == 0 && (vp->v_flag & VOBJDIRTY)) {
2229 		if ((obj = vp->v_object) != NULL) {
2230 			vm_object_page_clean(obj, 0, 0,
2231 			 flags == MNT_WAIT ? OBJPC_SYNC : OBJPC_NOSYNC);
2232 		}
2233 	}
2234 	return(0);
2235 }
2236 
2237 /*
2238  * Wake up anyone interested in vp because it is being revoked.
2239  */
2240 void
2241 vn_gone(struct vnode *vp)
2242 {
2243 	lwkt_gettoken(&vp->v_token);
2244 	KNOTE(&vp->v_pollinfo.vpi_kqinfo.ki_note, NOTE_REVOKE);
2245 	lwkt_reltoken(&vp->v_token);
2246 }
2247 
2248 /*
2249  * extract the cdev_t from a VBLK or VCHR.  The vnode must have been opened
2250  * (or v_rdev might be NULL).
2251  */
2252 cdev_t
2253 vn_todev(struct vnode *vp)
2254 {
2255 	if (vp->v_type != VBLK && vp->v_type != VCHR)
2256 		return (NULL);
2257 	KKASSERT(vp->v_rdev != NULL);
2258 	return (vp->v_rdev);
2259 }
2260 
2261 /*
2262  * Check if vnode represents a disk device.  The vnode does not need to be
2263  * opened.
2264  *
2265  * MPALMOSTSAFE
2266  */
2267 int
2268 vn_isdisk(struct vnode *vp, int *errp)
2269 {
2270 	cdev_t dev;
2271 
2272 	if (vp->v_type != VCHR) {
2273 		if (errp != NULL)
2274 			*errp = ENOTBLK;
2275 		return (0);
2276 	}
2277 
2278 	dev = vp->v_rdev;
2279 
2280 	if (dev == NULL) {
2281 		if (errp != NULL)
2282 			*errp = ENXIO;
2283 		return (0);
2284 	}
2285 	if (dev_is_good(dev) == 0) {
2286 		if (errp != NULL)
2287 			*errp = ENXIO;
2288 		return (0);
2289 	}
2290 	if ((dev_dflags(dev) & D_DISK) == 0) {
2291 		if (errp != NULL)
2292 			*errp = ENOTBLK;
2293 		return (0);
2294 	}
2295 	if (errp != NULL)
2296 		*errp = 0;
2297 	return (1);
2298 }
2299 
2300 int
2301 vn_get_namelen(struct vnode *vp, int *namelen)
2302 {
2303 	int error;
2304 	register_t retval[2];
2305 
2306 	error = VOP_PATHCONF(vp, _PC_NAME_MAX, retval);
2307 	if (error)
2308 		return (error);
2309 	*namelen = (int)retval[0];
2310 	return (0);
2311 }
2312 
2313 int
2314 vop_write_dirent(int *error, struct uio *uio, ino_t d_ino, uint8_t d_type,
2315 		uint16_t d_namlen, const char *d_name)
2316 {
2317 	struct dirent *dp;
2318 	size_t len;
2319 
2320 	len = _DIRENT_RECLEN(d_namlen);
2321 	if (len > uio->uio_resid)
2322 		return(1);
2323 
2324 	dp = kmalloc(len, M_TEMP, M_WAITOK | M_ZERO);
2325 
2326 	dp->d_ino = d_ino;
2327 	dp->d_namlen = d_namlen;
2328 	dp->d_type = d_type;
2329 	bcopy(d_name, dp->d_name, d_namlen);
2330 
2331 	*error = uiomove((caddr_t)dp, len, uio);
2332 
2333 	kfree(dp, M_TEMP);
2334 
2335 	return(0);
2336 }
2337 
2338 void
2339 vn_mark_atime(struct vnode *vp, struct thread *td)
2340 {
2341 	struct proc *p = td->td_proc;
2342 	struct ucred *cred = p ? p->p_ucred : proc0.p_ucred;
2343 
2344 	if ((vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) {
2345 		VOP_MARKATIME(vp, cred);
2346 	}
2347 }
2348