xref: /netbsd-src/sys/kern/vfs_subr.c (revision e89934bbf778a6d6d6894877c4da59d0c7835b0f)
1 /*	$NetBSD: vfs_subr.c,v 1.459 2017/01/11 14:52:02 hannken Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998, 2004, 2005, 2007, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center, by Charles M. Hannum, by Andrew Doran,
10  * by Marshall Kirk McKusick and Greg Ganger at the University of Michigan.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1989, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  * (c) UNIX System Laboratories, Inc.
38  * All or some portions of this file are derived from material licensed
39  * to the University of California by American Telephone and Telegraph
40  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
41  * the permission of UNIX System Laboratories, Inc.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 3. Neither the name of the University nor the names of its contributors
52  *    may be used to endorse or promote products derived from this software
53  *    without specific prior written permission.
54  *
55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
65  * SUCH DAMAGE.
66  *
67  *	@(#)vfs_subr.c	8.13 (Berkeley) 4/18/94
68  */
69 
70 #include <sys/cdefs.h>
71 __KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.459 2017/01/11 14:52:02 hannken Exp $");
72 
73 #ifdef _KERNEL_OPT
74 #include "opt_ddb.h"
75 #include "opt_compat_netbsd.h"
76 #include "opt_compat_43.h"
77 #endif
78 
79 #include <sys/param.h>
80 #include <sys/systm.h>
81 #include <sys/conf.h>
82 #include <sys/dirent.h>
83 #include <sys/filedesc.h>
84 #include <sys/kernel.h>
85 #include <sys/mount.h>
86 #include <sys/vnode_impl.h>
87 #include <sys/stat.h>
88 #include <sys/sysctl.h>
89 #include <sys/namei.h>
90 #include <sys/buf.h>
91 #include <sys/errno.h>
92 #include <sys/kmem.h>
93 #include <sys/syscallargs.h>
94 #include <sys/kauth.h>
95 #include <sys/module.h>
96 
97 #include <miscfs/genfs/genfs.h>
98 #include <miscfs/specfs/specdev.h>
99 #include <uvm/uvm_ddb.h>
100 
101 const enum vtype iftovt_tab[16] = {
102 	VNON, VFIFO, VCHR, VNON, VDIR, VNON, VBLK, VNON,
103 	VREG, VNON, VLNK, VNON, VSOCK, VNON, VNON, VBAD,
104 };
105 const int	vttoif_tab[9] = {
106 	0, S_IFREG, S_IFDIR, S_IFBLK, S_IFCHR, S_IFLNK,
107 	S_IFSOCK, S_IFIFO, S_IFMT,
108 };
109 
110 /*
111  * Insq/Remq for the vnode usage lists.
112  */
113 #define	bufinsvn(bp, dp)	LIST_INSERT_HEAD(dp, bp, b_vnbufs)
114 #define	bufremvn(bp) {							\
115 	LIST_REMOVE(bp, b_vnbufs);					\
116 	(bp)->b_vnbufs.le_next = NOLIST;				\
117 }
118 
119 int doforce = 1;		/* 1 => permit forcible unmounting */
120 int prtactive = 0;		/* 1 => print out reclaim of active vnodes */
121 
122 extern struct mount *dead_rootmount;
123 
124 /*
125  * Local declarations.
126  */
127 
128 static void vn_initialize_syncerd(void);
129 
130 /*
131  * Initialize the vnode management data structures.
132  */
133 void
134 vntblinit(void)
135 {
136 
137 	vn_initialize_syncerd();
138 	vfs_mount_sysinit();
139 	vfs_vnode_sysinit();
140 }
141 
142 /*
143  * Flush out and invalidate all buffers associated with a vnode.
144  * Called with the underlying vnode locked, which should prevent new dirty
145  * buffers from being queued.
146  */
147 int
148 vinvalbuf(struct vnode *vp, int flags, kauth_cred_t cred, struct lwp *l,
149 	  bool catch_p, int slptimeo)
150 {
151 	struct buf *bp, *nbp;
152 	int error;
153 	int flushflags = PGO_ALLPAGES | PGO_FREE | PGO_SYNCIO |
154 	    (flags & V_SAVE ? PGO_CLEANIT | PGO_RECLAIM : 0);
155 
156 	/* XXXUBC this doesn't look at flags or slp* */
157 	mutex_enter(vp->v_interlock);
158 	error = VOP_PUTPAGES(vp, 0, 0, flushflags);
159 	if (error) {
160 		return error;
161 	}
162 
163 	if (flags & V_SAVE) {
164 		error = VOP_FSYNC(vp, cred, FSYNC_WAIT|FSYNC_RECLAIM, 0, 0);
165 		if (error)
166 		        return (error);
167 		KASSERT(LIST_EMPTY(&vp->v_dirtyblkhd));
168 	}
169 
170 	mutex_enter(&bufcache_lock);
171 restart:
172 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
173 		KASSERT(bp->b_vp == vp);
174 		nbp = LIST_NEXT(bp, b_vnbufs);
175 		error = bbusy(bp, catch_p, slptimeo, NULL);
176 		if (error != 0) {
177 			if (error == EPASSTHROUGH)
178 				goto restart;
179 			mutex_exit(&bufcache_lock);
180 			return (error);
181 		}
182 		brelsel(bp, BC_INVAL | BC_VFLUSH);
183 	}
184 
185 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
186 		KASSERT(bp->b_vp == vp);
187 		nbp = LIST_NEXT(bp, b_vnbufs);
188 		error = bbusy(bp, catch_p, slptimeo, NULL);
189 		if (error != 0) {
190 			if (error == EPASSTHROUGH)
191 				goto restart;
192 			mutex_exit(&bufcache_lock);
193 			return (error);
194 		}
195 		/*
196 		 * XXX Since there are no node locks for NFS, I believe
197 		 * there is a slight chance that a delayed write will
198 		 * occur while sleeping just above, so check for it.
199 		 */
200 		if ((bp->b_oflags & BO_DELWRI) && (flags & V_SAVE)) {
201 #ifdef DEBUG
202 			printf("buffer still DELWRI\n");
203 #endif
204 			bp->b_cflags |= BC_BUSY | BC_VFLUSH;
205 			mutex_exit(&bufcache_lock);
206 			VOP_BWRITE(bp->b_vp, bp);
207 			mutex_enter(&bufcache_lock);
208 			goto restart;
209 		}
210 		brelsel(bp, BC_INVAL | BC_VFLUSH);
211 	}
212 
213 #ifdef DIAGNOSTIC
214 	if (!LIST_EMPTY(&vp->v_cleanblkhd) || !LIST_EMPTY(&vp->v_dirtyblkhd))
215 		panic("vinvalbuf: flush failed, vp %p", vp);
216 #endif
217 
218 	mutex_exit(&bufcache_lock);
219 
220 	return (0);
221 }
222 
223 /*
224  * Destroy any in core blocks past the truncation length.
225  * Called with the underlying vnode locked, which should prevent new dirty
226  * buffers from being queued.
227  */
228 int
229 vtruncbuf(struct vnode *vp, daddr_t lbn, bool catch_p, int slptimeo)
230 {
231 	struct buf *bp, *nbp;
232 	int error;
233 	voff_t off;
234 
235 	off = round_page((voff_t)lbn << vp->v_mount->mnt_fs_bshift);
236 	mutex_enter(vp->v_interlock);
237 	error = VOP_PUTPAGES(vp, off, 0, PGO_FREE | PGO_SYNCIO);
238 	if (error) {
239 		return error;
240 	}
241 
242 	mutex_enter(&bufcache_lock);
243 restart:
244 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
245 		KASSERT(bp->b_vp == vp);
246 		nbp = LIST_NEXT(bp, b_vnbufs);
247 		if (bp->b_lblkno < lbn)
248 			continue;
249 		error = bbusy(bp, catch_p, slptimeo, NULL);
250 		if (error != 0) {
251 			if (error == EPASSTHROUGH)
252 				goto restart;
253 			mutex_exit(&bufcache_lock);
254 			return (error);
255 		}
256 		brelsel(bp, BC_INVAL | BC_VFLUSH);
257 	}
258 
259 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
260 		KASSERT(bp->b_vp == vp);
261 		nbp = LIST_NEXT(bp, b_vnbufs);
262 		if (bp->b_lblkno < lbn)
263 			continue;
264 		error = bbusy(bp, catch_p, slptimeo, NULL);
265 		if (error != 0) {
266 			if (error == EPASSTHROUGH)
267 				goto restart;
268 			mutex_exit(&bufcache_lock);
269 			return (error);
270 		}
271 		brelsel(bp, BC_INVAL | BC_VFLUSH);
272 	}
273 	mutex_exit(&bufcache_lock);
274 
275 	return (0);
276 }
277 
278 /*
279  * Flush all dirty buffers from a vnode.
280  * Called with the underlying vnode locked, which should prevent new dirty
281  * buffers from being queued.
282  */
283 int
284 vflushbuf(struct vnode *vp, int flags)
285 {
286 	struct buf *bp, *nbp;
287 	int error, pflags;
288 	bool dirty, sync;
289 
290 	sync = (flags & FSYNC_WAIT) != 0;
291 	pflags = PGO_CLEANIT | PGO_ALLPAGES |
292 		(sync ? PGO_SYNCIO : 0) |
293 		((flags & FSYNC_LAZY) ? PGO_LAZY : 0);
294 	mutex_enter(vp->v_interlock);
295 	(void) VOP_PUTPAGES(vp, 0, 0, pflags);
296 
297 loop:
298 	mutex_enter(&bufcache_lock);
299 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
300 		KASSERT(bp->b_vp == vp);
301 		nbp = LIST_NEXT(bp, b_vnbufs);
302 		if ((bp->b_cflags & BC_BUSY))
303 			continue;
304 		if ((bp->b_oflags & BO_DELWRI) == 0)
305 			panic("vflushbuf: not dirty, bp %p", bp);
306 		bp->b_cflags |= BC_BUSY | BC_VFLUSH;
307 		mutex_exit(&bufcache_lock);
308 		/*
309 		 * Wait for I/O associated with indirect blocks to complete,
310 		 * since there is no way to quickly wait for them below.
311 		 */
312 		if (bp->b_vp == vp || !sync)
313 			(void) bawrite(bp);
314 		else {
315 			error = bwrite(bp);
316 			if (error)
317 				return error;
318 		}
319 		goto loop;
320 	}
321 	mutex_exit(&bufcache_lock);
322 
323 	if (!sync)
324 		return 0;
325 
326 	mutex_enter(vp->v_interlock);
327 	while (vp->v_numoutput != 0)
328 		cv_wait(&vp->v_cv, vp->v_interlock);
329 	dirty = !LIST_EMPTY(&vp->v_dirtyblkhd);
330 	mutex_exit(vp->v_interlock);
331 
332 	if (dirty) {
333 		vprint("vflushbuf: dirty", vp);
334 		goto loop;
335 	}
336 
337 	return 0;
338 }
339 
340 /*
341  * Create a vnode for a block device.
342  * Used for root filesystem and swap areas.
343  * Also used for memory file system special devices.
344  */
345 int
346 bdevvp(dev_t dev, vnode_t **vpp)
347 {
348 	struct vattr va;
349 
350 	vattr_null(&va);
351 	va.va_type = VBLK;
352 	va.va_rdev = dev;
353 
354 	return vcache_new(dead_rootmount, NULL, &va, NOCRED, vpp);
355 }
356 
357 /*
358  * Create a vnode for a character device.
359  * Used for kernfs and some console handling.
360  */
361 int
362 cdevvp(dev_t dev, vnode_t **vpp)
363 {
364 	struct vattr va;
365 
366 	vattr_null(&va);
367 	va.va_type = VCHR;
368 	va.va_rdev = dev;
369 
370 	return vcache_new(dead_rootmount, NULL, &va, NOCRED, vpp);
371 }
372 
373 /*
374  * Associate a buffer with a vnode.  There must already be a hold on
375  * the vnode.
376  */
377 void
378 bgetvp(struct vnode *vp, struct buf *bp)
379 {
380 
381 	KASSERT(bp->b_vp == NULL);
382 	KASSERT(bp->b_objlock == &buffer_lock);
383 	KASSERT(mutex_owned(vp->v_interlock));
384 	KASSERT(mutex_owned(&bufcache_lock));
385 	KASSERT((bp->b_cflags & BC_BUSY) != 0);
386 	KASSERT(!cv_has_waiters(&bp->b_done));
387 
388 	vholdl(vp);
389 	bp->b_vp = vp;
390 	if (vp->v_type == VBLK || vp->v_type == VCHR)
391 		bp->b_dev = vp->v_rdev;
392 	else
393 		bp->b_dev = NODEV;
394 
395 	/*
396 	 * Insert onto list for new vnode.
397 	 */
398 	bufinsvn(bp, &vp->v_cleanblkhd);
399 	bp->b_objlock = vp->v_interlock;
400 }
401 
402 /*
403  * Disassociate a buffer from a vnode.
404  */
405 void
406 brelvp(struct buf *bp)
407 {
408 	struct vnode *vp = bp->b_vp;
409 
410 	KASSERT(vp != NULL);
411 	KASSERT(bp->b_objlock == vp->v_interlock);
412 	KASSERT(mutex_owned(vp->v_interlock));
413 	KASSERT(mutex_owned(&bufcache_lock));
414 	KASSERT((bp->b_cflags & BC_BUSY) != 0);
415 	KASSERT(!cv_has_waiters(&bp->b_done));
416 
417 	/*
418 	 * Delete from old vnode list, if on one.
419 	 */
420 	if (LIST_NEXT(bp, b_vnbufs) != NOLIST)
421 		bufremvn(bp);
422 
423 	if (vp->v_uobj.uo_npages == 0 && (vp->v_iflag & VI_ONWORKLST) &&
424 	    LIST_FIRST(&vp->v_dirtyblkhd) == NULL) {
425 		vp->v_iflag &= ~VI_WRMAPDIRTY;
426 		vn_syncer_remove_from_worklist(vp);
427 	}
428 
429 	bp->b_objlock = &buffer_lock;
430 	bp->b_vp = NULL;
431 	holdrelel(vp);
432 }
433 
434 /*
435  * Reassign a buffer from one vnode list to another.
436  * The list reassignment must be within the same vnode.
437  * Used to assign file specific control information
438  * (indirect blocks) to the list to which they belong.
439  */
440 void
441 reassignbuf(struct buf *bp, struct vnode *vp)
442 {
443 	struct buflists *listheadp;
444 	int delayx;
445 
446 	KASSERT(mutex_owned(&bufcache_lock));
447 	KASSERT(bp->b_objlock == vp->v_interlock);
448 	KASSERT(mutex_owned(vp->v_interlock));
449 	KASSERT((bp->b_cflags & BC_BUSY) != 0);
450 
451 	/*
452 	 * Delete from old vnode list, if on one.
453 	 */
454 	if (LIST_NEXT(bp, b_vnbufs) != NOLIST)
455 		bufremvn(bp);
456 
457 	/*
458 	 * If dirty, put on list of dirty buffers;
459 	 * otherwise insert onto list of clean buffers.
460 	 */
461 	if ((bp->b_oflags & BO_DELWRI) == 0) {
462 		listheadp = &vp->v_cleanblkhd;
463 		if (vp->v_uobj.uo_npages == 0 &&
464 		    (vp->v_iflag & VI_ONWORKLST) &&
465 		    LIST_FIRST(&vp->v_dirtyblkhd) == NULL) {
466 			vp->v_iflag &= ~VI_WRMAPDIRTY;
467 			vn_syncer_remove_from_worklist(vp);
468 		}
469 	} else {
470 		listheadp = &vp->v_dirtyblkhd;
471 		if ((vp->v_iflag & VI_ONWORKLST) == 0) {
472 			switch (vp->v_type) {
473 			case VDIR:
474 				delayx = dirdelay;
475 				break;
476 			case VBLK:
477 				if (spec_node_getmountedfs(vp) != NULL) {
478 					delayx = metadelay;
479 					break;
480 				}
481 				/* fall through */
482 			default:
483 				delayx = filedelay;
484 				break;
485 			}
486 			if (!vp->v_mount ||
487 			    (vp->v_mount->mnt_flag & MNT_ASYNC) == 0)
488 				vn_syncer_add_to_worklist(vp, delayx);
489 		}
490 	}
491 	bufinsvn(bp, listheadp);
492 }
493 
494 /*
495  * Lookup a vnode by device number and return it referenced.
496  */
497 int
498 vfinddev(dev_t dev, enum vtype type, vnode_t **vpp)
499 {
500 
501 	return (spec_node_lookup_by_dev(type, dev, vpp) == 0);
502 }
503 
504 /*
505  * Revoke all the vnodes corresponding to the specified minor number
506  * range (endpoints inclusive) of the specified major.
507  */
508 void
509 vdevgone(int maj, int minl, int minh, enum vtype type)
510 {
511 	vnode_t *vp;
512 	dev_t dev;
513 	int mn;
514 
515 	for (mn = minl; mn <= minh; mn++) {
516 		dev = makedev(maj, mn);
517 		while (spec_node_lookup_by_dev(type, dev, &vp) == 0) {
518 			VOP_REVOKE(vp, REVOKEALL);
519 			vrele(vp);
520 		}
521 	}
522 }
523 
524 /*
525  * The filesystem synchronizer mechanism - syncer.
526  *
527  * It is useful to delay writes of file data and filesystem metadata for
528  * a certain amount of time so that quickly created and deleted files need
529  * not waste disk bandwidth being created and removed.  To implement this,
530  * vnodes are appended to a "workitem" queue.
531  *
532  * Most pending metadata should not wait for more than ten seconds.  Thus,
533  * mounted on block devices are delayed only about a half the time that file
534  * data is delayed.  Similarly, directory updates are more critical, so are
535  * only delayed about a third the time that file data is delayed.
536  *
537  * There are SYNCER_MAXDELAY queues that are processed in a round-robin
538  * manner at a rate of one each second (driven off the filesystem syner
539  * thread). The syncer_delayno variable indicates the next queue that is
540  * to be processed.  Items that need to be processed soon are placed in
541  * this queue:
542  *
543  *	syncer_workitem_pending[syncer_delayno]
544  *
545  * A delay of e.g. fifteen seconds is done by placing the request fifteen
546  * entries later in the queue:
547  *
548  *	syncer_workitem_pending[(syncer_delayno + 15) & syncer_mask]
549  *
550  * Flag VI_ONWORKLST indicates that vnode is added into the queue.
551  */
552 
553 #define SYNCER_MAXDELAY		32
554 
555 typedef TAILQ_HEAD(synclist, vnode_impl) synclist_t;
556 
557 static void	vn_syncer_add1(struct vnode *, int);
558 static void	sysctl_vfs_syncfs_setup(struct sysctllog **);
559 
560 /*
561  * Defines and variables for the syncer process.
562  */
563 int syncer_maxdelay = SYNCER_MAXDELAY;	/* maximum delay time */
564 time_t syncdelay = 30;			/* max time to delay syncing data */
565 time_t filedelay = 30;			/* time to delay syncing files */
566 time_t dirdelay  = 15;			/* time to delay syncing directories */
567 time_t metadelay = 10;			/* time to delay syncing metadata */
568 time_t lockdelay = 1;			/* time to delay if locking fails */
569 
570 kmutex_t		syncer_mutex;	/* used to freeze syncer, long term */
571 static kmutex_t		syncer_data_lock; /* short term lock on data structs */
572 
573 static int		syncer_delayno = 0;
574 static long		syncer_last;
575 static synclist_t *	syncer_workitem_pending;
576 
577 static void
578 vn_initialize_syncerd(void)
579 {
580 	int i;
581 
582 	syncer_last = SYNCER_MAXDELAY + 2;
583 
584 	sysctl_vfs_syncfs_setup(NULL);
585 
586 	syncer_workitem_pending =
587 	    kmem_alloc(syncer_last * sizeof (struct synclist), KM_SLEEP);
588 
589 	for (i = 0; i < syncer_last; i++)
590 		TAILQ_INIT(&syncer_workitem_pending[i]);
591 
592 	mutex_init(&syncer_mutex, MUTEX_DEFAULT, IPL_NONE);
593 	mutex_init(&syncer_data_lock, MUTEX_DEFAULT, IPL_NONE);
594 }
595 
596 /*
597  * Return delay factor appropriate for the given file system.   For
598  * WAPBL we use the sync vnode to burst out metadata updates: sync
599  * those file systems more frequently.
600  */
601 static inline int
602 sync_delay(struct mount *mp)
603 {
604 
605 	return mp->mnt_wapbl != NULL ? metadelay : syncdelay;
606 }
607 
608 /*
609  * Compute the next slot index from delay.
610  */
611 static inline int
612 sync_delay_slot(int delayx)
613 {
614 
615 	if (delayx > syncer_maxdelay - 2)
616 		delayx = syncer_maxdelay - 2;
617 	return (syncer_delayno + delayx) % syncer_last;
618 }
619 
620 /*
621  * Add an item to the syncer work queue.
622  */
623 static void
624 vn_syncer_add1(struct vnode *vp, int delayx)
625 {
626 	synclist_t *slp;
627 	vnode_impl_t *vip = VNODE_TO_VIMPL(vp);
628 
629 	KASSERT(mutex_owned(&syncer_data_lock));
630 
631 	if (vp->v_iflag & VI_ONWORKLST) {
632 		/*
633 		 * Remove in order to adjust the position of the vnode.
634 		 * Note: called from sched_sync(), which will not hold
635 		 * interlock, therefore we cannot modify v_iflag here.
636 		 */
637 		slp = &syncer_workitem_pending[vip->vi_synclist_slot];
638 		TAILQ_REMOVE(slp, vip, vi_synclist);
639 	} else {
640 		KASSERT(mutex_owned(vp->v_interlock));
641 		vp->v_iflag |= VI_ONWORKLST;
642 	}
643 
644 	vip->vi_synclist_slot = sync_delay_slot(delayx);
645 
646 	slp = &syncer_workitem_pending[vip->vi_synclist_slot];
647 	TAILQ_INSERT_TAIL(slp, vip, vi_synclist);
648 }
649 
650 void
651 vn_syncer_add_to_worklist(struct vnode *vp, int delayx)
652 {
653 
654 	KASSERT(mutex_owned(vp->v_interlock));
655 
656 	mutex_enter(&syncer_data_lock);
657 	vn_syncer_add1(vp, delayx);
658 	mutex_exit(&syncer_data_lock);
659 }
660 
661 /*
662  * Remove an item from the syncer work queue.
663  */
664 void
665 vn_syncer_remove_from_worklist(struct vnode *vp)
666 {
667 	synclist_t *slp;
668 	vnode_impl_t *vip = VNODE_TO_VIMPL(vp);
669 
670 	KASSERT(mutex_owned(vp->v_interlock));
671 
672 	mutex_enter(&syncer_data_lock);
673 	if (vp->v_iflag & VI_ONWORKLST) {
674 		vp->v_iflag &= ~VI_ONWORKLST;
675 		slp = &syncer_workitem_pending[vip->vi_synclist_slot];
676 		TAILQ_REMOVE(slp, vip, vi_synclist);
677 	}
678 	mutex_exit(&syncer_data_lock);
679 }
680 
681 /*
682  * Add this mount point to the syncer.
683  */
684 void
685 vfs_syncer_add_to_worklist(struct mount *mp)
686 {
687 	static int start, incr, next;
688 	int vdelay;
689 
690 	KASSERT(mutex_owned(&mp->mnt_updating));
691 	KASSERT((mp->mnt_iflag & IMNT_ONWORKLIST) == 0);
692 
693 	/*
694 	 * We attempt to scatter the mount points on the list
695 	 * so that they will go off at evenly distributed times
696 	 * even if all the filesystems are mounted at once.
697 	 */
698 
699 	next += incr;
700 	if (next == 0 || next > syncer_maxdelay) {
701 		start /= 2;
702 		incr /= 2;
703 		if (start == 0) {
704 			start = syncer_maxdelay / 2;
705 			incr = syncer_maxdelay;
706 		}
707 		next = start;
708 	}
709 	mp->mnt_iflag |= IMNT_ONWORKLIST;
710 	vdelay = sync_delay(mp);
711 	mp->mnt_synclist_slot = vdelay > 0 ? next % vdelay : 0;
712 }
713 
714 /*
715  * Remove the mount point from the syncer.
716  */
717 void
718 vfs_syncer_remove_from_worklist(struct mount *mp)
719 {
720 
721 	KASSERT(mutex_owned(&mp->mnt_updating));
722 	KASSERT((mp->mnt_iflag & IMNT_ONWORKLIST) != 0);
723 
724 	mp->mnt_iflag &= ~IMNT_ONWORKLIST;
725 }
726 
727 /*
728  * Try lazy sync, return true on success.
729  */
730 static bool
731 lazy_sync_vnode(struct vnode *vp)
732 {
733 	bool synced;
734 
735 	KASSERT(mutex_owned(&syncer_data_lock));
736 
737 	synced = false;
738 	/* We are locking in the wrong direction. */
739 	if (mutex_tryenter(vp->v_interlock)) {
740 		mutex_exit(&syncer_data_lock);
741 		if (vcache_tryvget(vp) == 0) {
742 			if (vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT) == 0) {
743 				synced = true;
744 				(void) VOP_FSYNC(vp, curlwp->l_cred,
745 				    FSYNC_LAZY, 0, 0);
746 				vput(vp);
747 			} else
748 				vrele(vp);
749 		}
750 		mutex_enter(&syncer_data_lock);
751 	}
752 	return synced;
753 }
754 
755 /*
756  * System filesystem synchronizer daemon.
757  */
758 void
759 sched_sync(void *arg)
760 {
761 	synclist_t *slp;
762 	struct vnode *vp;
763 	struct mount *mp, *nmp;
764 	time_t starttime;
765 	bool synced;
766 
767 	for (;;) {
768 		mutex_enter(&syncer_mutex);
769 
770 		starttime = time_second;
771 
772 		/*
773 		 * Sync mounts whose dirty time has expired.
774 		 */
775 		mutex_enter(&mountlist_lock);
776 		for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
777 			if ((mp->mnt_iflag & IMNT_ONWORKLIST) == 0 ||
778 			    mp->mnt_synclist_slot != syncer_delayno) {
779 				nmp = TAILQ_NEXT(mp, mnt_list);
780 				continue;
781 			}
782 			mp->mnt_synclist_slot = sync_delay_slot(sync_delay(mp));
783 			if (vfs_busy(mp, &nmp))
784 				continue;
785 			VFS_SYNC(mp, MNT_LAZY, curlwp->l_cred);
786 			vfs_unbusy(mp, false, &nmp);
787 		}
788 		mutex_exit(&mountlist_lock);
789 
790 		mutex_enter(&syncer_data_lock);
791 
792 		/*
793 		 * Push files whose dirty time has expired.
794 		 */
795 		slp = &syncer_workitem_pending[syncer_delayno];
796 		syncer_delayno += 1;
797 		if (syncer_delayno >= syncer_last)
798 			syncer_delayno = 0;
799 
800 		while ((vp = VIMPL_TO_VNODE(TAILQ_FIRST(slp))) != NULL) {
801 			synced = lazy_sync_vnode(vp);
802 
803 			/*
804 			 * XXX The vnode may have been recycled, in which
805 			 * case it may have a new identity.
806 			 */
807 			if (VIMPL_TO_VNODE(TAILQ_FIRST(slp)) == vp) {
808 				/*
809 				 * Put us back on the worklist.  The worklist
810 				 * routine will remove us from our current
811 				 * position and then add us back in at a later
812 				 * position.
813 				 *
814 				 * Try again sooner rather than later if
815 				 * we were unable to lock the vnode.  Lock
816 				 * failure should not prevent us from doing
817 				 * the sync "soon".
818 				 *
819 				 * If we locked it yet arrive here, it's
820 				 * likely that lazy sync is in progress and
821 				 * so the vnode still has dirty metadata.
822 				 * syncdelay is mainly to get this vnode out
823 				 * of the way so we do not consider it again
824 				 * "soon" in this loop, so the delay time is
825 				 * not critical as long as it is not "soon".
826 				 * While write-back strategy is the file
827 				 * system's domain, we expect write-back to
828 				 * occur no later than syncdelay seconds
829 				 * into the future.
830 				 */
831 				vn_syncer_add1(vp,
832 				    synced ? syncdelay : lockdelay);
833 			}
834 		}
835 		mutex_exit(&syncer_mutex);
836 
837 		/*
838 		 * If it has taken us less than a second to process the
839 		 * current work, then wait.  Otherwise start right over
840 		 * again.  We can still lose time if any single round
841 		 * takes more than two seconds, but it does not really
842 		 * matter as we are just trying to generally pace the
843 		 * filesystem activity.
844 		 */
845 		if (time_second == starttime) {
846 			kpause("syncer", false, hz, &syncer_data_lock);
847 		}
848 		mutex_exit(&syncer_data_lock);
849 	}
850 }
851 
852 static void
853 sysctl_vfs_syncfs_setup(struct sysctllog **clog)
854 {
855 	const struct sysctlnode *rnode, *cnode;
856 
857 	sysctl_createv(clog, 0, NULL, &rnode,
858 			CTLFLAG_PERMANENT,
859 			CTLTYPE_NODE, "sync",
860 			SYSCTL_DESCR("syncer options"),
861 			NULL, 0, NULL, 0,
862 			CTL_VFS, CTL_CREATE, CTL_EOL);
863 
864 	sysctl_createv(clog, 0, &rnode, &cnode,
865 			CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
866 			CTLTYPE_QUAD, "delay",
867 			SYSCTL_DESCR("max time to delay syncing data"),
868 			NULL, 0, &syncdelay, 0,
869 			CTL_CREATE, CTL_EOL);
870 
871 	sysctl_createv(clog, 0, &rnode, &cnode,
872 			CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
873 			CTLTYPE_QUAD, "filedelay",
874 			SYSCTL_DESCR("time to delay syncing files"),
875 			NULL, 0, &filedelay, 0,
876 			CTL_CREATE, CTL_EOL);
877 
878 	sysctl_createv(clog, 0, &rnode, &cnode,
879 			CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
880 			CTLTYPE_QUAD, "dirdelay",
881 			SYSCTL_DESCR("time to delay syncing directories"),
882 			NULL, 0, &dirdelay, 0,
883 			CTL_CREATE, CTL_EOL);
884 
885 	sysctl_createv(clog, 0, &rnode, &cnode,
886 			CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
887 			CTLTYPE_QUAD, "metadelay",
888 			SYSCTL_DESCR("time to delay syncing metadata"),
889 			NULL, 0, &metadelay, 0,
890 			CTL_CREATE, CTL_EOL);
891 }
892 
893 /*
894  * sysctl helper routine to return list of supported fstypes
895  */
896 int
897 sysctl_vfs_generic_fstypes(SYSCTLFN_ARGS)
898 {
899 	char bf[sizeof(((struct statvfs *)NULL)->f_fstypename)];
900 	char *where = oldp;
901 	struct vfsops *v;
902 	size_t needed, left, slen;
903 	int error, first;
904 
905 	if (newp != NULL)
906 		return (EPERM);
907 	if (namelen != 0)
908 		return (EINVAL);
909 
910 	first = 1;
911 	error = 0;
912 	needed = 0;
913 	left = *oldlenp;
914 
915 	sysctl_unlock();
916 	mutex_enter(&vfs_list_lock);
917 	LIST_FOREACH(v, &vfs_list, vfs_list) {
918 		if (where == NULL)
919 			needed += strlen(v->vfs_name) + 1;
920 		else {
921 			memset(bf, 0, sizeof(bf));
922 			if (first) {
923 				strncpy(bf, v->vfs_name, sizeof(bf));
924 				first = 0;
925 			} else {
926 				bf[0] = ' ';
927 				strncpy(bf + 1, v->vfs_name, sizeof(bf) - 1);
928 			}
929 			bf[sizeof(bf)-1] = '\0';
930 			slen = strlen(bf);
931 			if (left < slen + 1)
932 				break;
933 			v->vfs_refcount++;
934 			mutex_exit(&vfs_list_lock);
935 			/* +1 to copy out the trailing NUL byte */
936 			error = copyout(bf, where, slen + 1);
937 			mutex_enter(&vfs_list_lock);
938 			v->vfs_refcount--;
939 			if (error)
940 				break;
941 			where += slen;
942 			needed += slen;
943 			left -= slen;
944 		}
945 	}
946 	mutex_exit(&vfs_list_lock);
947 	sysctl_relock();
948 	*oldlenp = needed;
949 	return (error);
950 }
951 
952 int kinfo_vdebug = 1;
953 int kinfo_vgetfailed;
954 
955 #define KINFO_VNODESLOP	10
956 
957 /*
958  * Dump vnode list (via sysctl).
959  * Copyout address of vnode followed by vnode.
960  */
961 int
962 sysctl_kern_vnode(SYSCTLFN_ARGS)
963 {
964 	char *where = oldp;
965 	size_t *sizep = oldlenp;
966 	struct mount *mp, *nmp;
967 	vnode_t *vp, vbuf;
968 	struct vnode_iterator *marker;
969 	char *bp = where;
970 	char *ewhere;
971 	int error;
972 
973 	if (namelen != 0)
974 		return (EOPNOTSUPP);
975 	if (newp != NULL)
976 		return (EPERM);
977 
978 #define VPTRSZ	sizeof(vnode_t *)
979 #define VNODESZ	sizeof(vnode_t)
980 	if (where == NULL) {
981 		*sizep = (numvnodes + KINFO_VNODESLOP) * (VPTRSZ + VNODESZ);
982 		return (0);
983 	}
984 	ewhere = where + *sizep;
985 
986 	sysctl_unlock();
987 	mutex_enter(&mountlist_lock);
988 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
989 		if (vfs_busy(mp, &nmp)) {
990 			continue;
991 		}
992 		vfs_vnode_iterator_init(mp, &marker);
993 		while ((vp = vfs_vnode_iterator_next(marker, NULL, NULL))) {
994 			if (bp + VPTRSZ + VNODESZ > ewhere) {
995 				vrele(vp);
996 				vfs_vnode_iterator_destroy(marker);
997 				vfs_unbusy(mp, false, NULL);
998 				sysctl_relock();
999 				*sizep = bp - where;
1000 				return (ENOMEM);
1001 			}
1002 			memcpy(&vbuf, vp, VNODESZ);
1003 			if ((error = copyout(&vp, bp, VPTRSZ)) ||
1004 			    (error = copyout(&vbuf, bp + VPTRSZ, VNODESZ))) {
1005 				vrele(vp);
1006 				vfs_vnode_iterator_destroy(marker);
1007 				vfs_unbusy(mp, false, NULL);
1008 				sysctl_relock();
1009 				return (error);
1010 			}
1011 			vrele(vp);
1012 			bp += VPTRSZ + VNODESZ;
1013 		}
1014 		vfs_vnode_iterator_destroy(marker);
1015 		vfs_unbusy(mp, false, &nmp);
1016 	}
1017 	mutex_exit(&mountlist_lock);
1018 	sysctl_relock();
1019 
1020 	*sizep = bp - where;
1021 	return (0);
1022 }
1023 
1024 /*
1025  * Set vnode attributes to VNOVAL
1026  */
1027 void
1028 vattr_null(struct vattr *vap)
1029 {
1030 
1031 	memset(vap, 0, sizeof(*vap));
1032 
1033 	vap->va_type = VNON;
1034 
1035 	/*
1036 	 * Assign individually so that it is safe even if size and
1037 	 * sign of each member are varied.
1038 	 */
1039 	vap->va_mode = VNOVAL;
1040 	vap->va_nlink = VNOVAL;
1041 	vap->va_uid = VNOVAL;
1042 	vap->va_gid = VNOVAL;
1043 	vap->va_fsid = VNOVAL;
1044 	vap->va_fileid = VNOVAL;
1045 	vap->va_size = VNOVAL;
1046 	vap->va_blocksize = VNOVAL;
1047 	vap->va_atime.tv_sec =
1048 	    vap->va_mtime.tv_sec =
1049 	    vap->va_ctime.tv_sec =
1050 	    vap->va_birthtime.tv_sec = VNOVAL;
1051 	vap->va_atime.tv_nsec =
1052 	    vap->va_mtime.tv_nsec =
1053 	    vap->va_ctime.tv_nsec =
1054 	    vap->va_birthtime.tv_nsec = VNOVAL;
1055 	vap->va_gen = VNOVAL;
1056 	vap->va_flags = VNOVAL;
1057 	vap->va_rdev = VNOVAL;
1058 	vap->va_bytes = VNOVAL;
1059 }
1060 
1061 /*
1062  * Vnode state to string.
1063  */
1064 const char *
1065 vstate_name(enum vnode_state state)
1066 {
1067 
1068 	switch (state) {
1069 	case VS_MARKER:
1070 		return "MARKER";
1071 	case VS_LOADING:
1072 		return "LOADING";
1073 	case VS_ACTIVE:
1074 		return "ACTIVE";
1075 	case VS_BLOCKED:
1076 		return "BLOCKED";
1077 	case VS_RECLAIMING:
1078 		return "RECLAIMING";
1079 	case VS_RECLAIMED:
1080 		return "RECLAIMED";
1081 	default:
1082 		return "ILLEGAL";
1083 	}
1084 }
1085 
1086 /*
1087  * Print a description of a vnode (common part).
1088  */
1089 static void
1090 vprint_common(struct vnode *vp, const char *prefix,
1091     void (*pr)(const char *, ...) __printflike(1, 2))
1092 {
1093 	int n;
1094 	char bf[96];
1095 	const uint8_t *cp;
1096 	vnode_impl_t *vip;
1097 	const char * const vnode_tags[] = { VNODE_TAGS };
1098 	const char * const vnode_types[] = { VNODE_TYPES };
1099 	const char vnode_flagbits[] = VNODE_FLAGBITS;
1100 
1101 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
1102 #define ARRAY_PRINT(idx, arr) \
1103     ((unsigned int)(idx) < ARRAY_SIZE(arr) ? (arr)[(idx)] : "UNKNOWN")
1104 
1105 	vip = VNODE_TO_VIMPL(vp);
1106 
1107 	snprintb(bf, sizeof(bf),
1108 	    vnode_flagbits, vp->v_iflag | vp->v_vflag | vp->v_uflag);
1109 
1110 	(*pr)("vnode %p flags %s\n", vp, bf);
1111 	(*pr)("%stag %s(%d) type %s(%d) mount %p typedata %p\n", prefix,
1112 	    ARRAY_PRINT(vp->v_tag, vnode_tags), vp->v_tag,
1113 	    ARRAY_PRINT(vp->v_type, vnode_types), vp->v_type,
1114 	    vp->v_mount, vp->v_mountedhere);
1115 	(*pr)("%susecount %d writecount %d holdcount %d\n", prefix,
1116 	    vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
1117 	(*pr)("%ssize %" PRIx64 " writesize %" PRIx64 " numoutput %d\n",
1118 	    prefix, vp->v_size, vp->v_writesize, vp->v_numoutput);
1119 	(*pr)("%sdata %p lock %p\n", prefix, vp->v_data, &vip->vi_lock);
1120 
1121 	(*pr)("%sstate %s key(%p %zd)", prefix, vstate_name(vip->vi_state),
1122 	    vip->vi_key.vk_mount, vip->vi_key.vk_key_len);
1123 	n = vip->vi_key.vk_key_len;
1124 	cp = vip->vi_key.vk_key;
1125 	while (n-- > 0)
1126 		(*pr)(" %02x", *cp++);
1127 	(*pr)("\n");
1128 	(*pr)("%slrulisthd %p\n", prefix, vip->vi_lrulisthd);
1129 
1130 #undef ARRAY_PRINT
1131 #undef ARRAY_SIZE
1132 }
1133 
1134 /*
1135  * Print out a description of a vnode.
1136  */
1137 void
1138 vprint(const char *label, struct vnode *vp)
1139 {
1140 
1141 	if (label != NULL)
1142 		printf("%s: ", label);
1143 	vprint_common(vp, "\t", printf);
1144 	if (vp->v_data != NULL) {
1145 		printf("\t");
1146 		VOP_PRINT(vp);
1147 	}
1148 }
1149 
1150 /* Deprecated. Kept for KPI compatibility. */
1151 int
1152 vaccess(enum vtype type, mode_t file_mode, uid_t uid, gid_t gid,
1153     mode_t acc_mode, kauth_cred_t cred)
1154 {
1155 
1156 #ifdef DIAGNOSTIC
1157 	printf("vaccess: deprecated interface used.\n");
1158 #endif /* DIAGNOSTIC */
1159 
1160 	return kauth_authorize_vnode(cred, KAUTH_ACCESS_ACTION(acc_mode,
1161 	    type, file_mode), NULL /* This may panic. */, NULL,
1162 	    genfs_can_access(type, file_mode, uid, gid, acc_mode, cred));
1163 }
1164 
1165 /*
1166  * Given a file system name, look up the vfsops for that
1167  * file system, or return NULL if file system isn't present
1168  * in the kernel.
1169  */
1170 struct vfsops *
1171 vfs_getopsbyname(const char *name)
1172 {
1173 	struct vfsops *v;
1174 
1175 	mutex_enter(&vfs_list_lock);
1176 	LIST_FOREACH(v, &vfs_list, vfs_list) {
1177 		if (strcmp(v->vfs_name, name) == 0)
1178 			break;
1179 	}
1180 	if (v != NULL)
1181 		v->vfs_refcount++;
1182 	mutex_exit(&vfs_list_lock);
1183 
1184 	return (v);
1185 }
1186 
1187 void
1188 copy_statvfs_info(struct statvfs *sbp, const struct mount *mp)
1189 {
1190 	const struct statvfs *mbp;
1191 
1192 	if (sbp == (mbp = &mp->mnt_stat))
1193 		return;
1194 
1195 	(void)memcpy(&sbp->f_fsidx, &mbp->f_fsidx, sizeof(sbp->f_fsidx));
1196 	sbp->f_fsid = mbp->f_fsid;
1197 	sbp->f_owner = mbp->f_owner;
1198 	sbp->f_flag = mbp->f_flag;
1199 	sbp->f_syncwrites = mbp->f_syncwrites;
1200 	sbp->f_asyncwrites = mbp->f_asyncwrites;
1201 	sbp->f_syncreads = mbp->f_syncreads;
1202 	sbp->f_asyncreads = mbp->f_asyncreads;
1203 	(void)memcpy(sbp->f_spare, mbp->f_spare, sizeof(mbp->f_spare));
1204 	(void)memcpy(sbp->f_fstypename, mbp->f_fstypename,
1205 	    sizeof(sbp->f_fstypename));
1206 	(void)memcpy(sbp->f_mntonname, mbp->f_mntonname,
1207 	    sizeof(sbp->f_mntonname));
1208 	(void)memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname,
1209 	    sizeof(sbp->f_mntfromname));
1210 	sbp->f_namemax = mbp->f_namemax;
1211 }
1212 
1213 int
1214 set_statvfs_info(const char *onp, int ukon, const char *fromp, int ukfrom,
1215     const char *vfsname, struct mount *mp, struct lwp *l)
1216 {
1217 	int error;
1218 	size_t size;
1219 	struct statvfs *sfs = &mp->mnt_stat;
1220 	int (*fun)(const void *, void *, size_t, size_t *);
1221 
1222 	(void)strlcpy(mp->mnt_stat.f_fstypename, vfsname,
1223 	    sizeof(mp->mnt_stat.f_fstypename));
1224 
1225 	if (onp) {
1226 		struct cwdinfo *cwdi = l->l_proc->p_cwdi;
1227 		fun = (ukon == UIO_SYSSPACE) ? copystr : copyinstr;
1228 		if (cwdi->cwdi_rdir != NULL) {
1229 			size_t len;
1230 			char *bp;
1231 			char *path = PNBUF_GET();
1232 
1233 			bp = path + MAXPATHLEN;
1234 			*--bp = '\0';
1235 			rw_enter(&cwdi->cwdi_lock, RW_READER);
1236 			error = getcwd_common(cwdi->cwdi_rdir, rootvnode, &bp,
1237 			    path, MAXPATHLEN / 2, 0, l);
1238 			rw_exit(&cwdi->cwdi_lock);
1239 			if (error) {
1240 				PNBUF_PUT(path);
1241 				return error;
1242 			}
1243 
1244 			len = strlen(bp);
1245 			if (len > sizeof(sfs->f_mntonname) - 1)
1246 				len = sizeof(sfs->f_mntonname) - 1;
1247 			(void)strncpy(sfs->f_mntonname, bp, len);
1248 			PNBUF_PUT(path);
1249 
1250 			if (len < sizeof(sfs->f_mntonname) - 1) {
1251 				error = (*fun)(onp, &sfs->f_mntonname[len],
1252 				    sizeof(sfs->f_mntonname) - len - 1, &size);
1253 				if (error)
1254 					return error;
1255 				size += len;
1256 			} else {
1257 				size = len;
1258 			}
1259 		} else {
1260 			error = (*fun)(onp, &sfs->f_mntonname,
1261 			    sizeof(sfs->f_mntonname) - 1, &size);
1262 			if (error)
1263 				return error;
1264 		}
1265 		(void)memset(sfs->f_mntonname + size, 0,
1266 		    sizeof(sfs->f_mntonname) - size);
1267 	}
1268 
1269 	if (fromp) {
1270 		fun = (ukfrom == UIO_SYSSPACE) ? copystr : copyinstr;
1271 		error = (*fun)(fromp, sfs->f_mntfromname,
1272 		    sizeof(sfs->f_mntfromname) - 1, &size);
1273 		if (error)
1274 			return error;
1275 		(void)memset(sfs->f_mntfromname + size, 0,
1276 		    sizeof(sfs->f_mntfromname) - size);
1277 	}
1278 	return 0;
1279 }
1280 
1281 void
1282 vfs_timestamp(struct timespec *ts)
1283 {
1284 
1285 	nanotime(ts);
1286 }
1287 
1288 time_t	rootfstime;			/* recorded root fs time, if known */
1289 void
1290 setrootfstime(time_t t)
1291 {
1292 	rootfstime = t;
1293 }
1294 
1295 static const uint8_t vttodt_tab[ ] = {
1296 	[VNON]	=	DT_UNKNOWN,
1297 	[VREG]	=	DT_REG,
1298 	[VDIR]	=	DT_DIR,
1299 	[VBLK]	=	DT_BLK,
1300 	[VCHR]	=	DT_CHR,
1301 	[VLNK]	=	DT_LNK,
1302 	[VSOCK]	=	DT_SOCK,
1303 	[VFIFO]	=	DT_FIFO,
1304 	[VBAD]	=	DT_UNKNOWN
1305 };
1306 
1307 uint8_t
1308 vtype2dt(enum vtype vt)
1309 {
1310 
1311 	CTASSERT(VBAD == __arraycount(vttodt_tab) - 1);
1312 	return vttodt_tab[vt];
1313 }
1314 
1315 int
1316 VFS_MOUNT(struct mount *mp, const char *a, void *b, size_t *c)
1317 {
1318 	int error;
1319 
1320 	KERNEL_LOCK(1, NULL);
1321 	error = (*(mp->mnt_op->vfs_mount))(mp, a, b, c);
1322 	KERNEL_UNLOCK_ONE(NULL);
1323 
1324 	return error;
1325 }
1326 
1327 int
1328 VFS_START(struct mount *mp, int a)
1329 {
1330 	int error;
1331 
1332 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1333 		KERNEL_LOCK(1, NULL);
1334 	}
1335 	error = (*(mp->mnt_op->vfs_start))(mp, a);
1336 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1337 		KERNEL_UNLOCK_ONE(NULL);
1338 	}
1339 
1340 	return error;
1341 }
1342 
1343 int
1344 VFS_UNMOUNT(struct mount *mp, int a)
1345 {
1346 	int error;
1347 
1348 	KERNEL_LOCK(1, NULL);
1349 	error = (*(mp->mnt_op->vfs_unmount))(mp, a);
1350 	KERNEL_UNLOCK_ONE(NULL);
1351 
1352 	return error;
1353 }
1354 
1355 int
1356 VFS_ROOT(struct mount *mp, struct vnode **a)
1357 {
1358 	int error;
1359 
1360 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1361 		KERNEL_LOCK(1, NULL);
1362 	}
1363 	error = (*(mp->mnt_op->vfs_root))(mp, a);
1364 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1365 		KERNEL_UNLOCK_ONE(NULL);
1366 	}
1367 
1368 	return error;
1369 }
1370 
1371 int
1372 VFS_QUOTACTL(struct mount *mp, struct quotactl_args *args)
1373 {
1374 	int error;
1375 
1376 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1377 		KERNEL_LOCK(1, NULL);
1378 	}
1379 	error = (*(mp->mnt_op->vfs_quotactl))(mp, args);
1380 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1381 		KERNEL_UNLOCK_ONE(NULL);
1382 	}
1383 
1384 	return error;
1385 }
1386 
1387 int
1388 VFS_STATVFS(struct mount *mp, struct statvfs *a)
1389 {
1390 	int error;
1391 
1392 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1393 		KERNEL_LOCK(1, NULL);
1394 	}
1395 	error = (*(mp->mnt_op->vfs_statvfs))(mp, a);
1396 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1397 		KERNEL_UNLOCK_ONE(NULL);
1398 	}
1399 
1400 	return error;
1401 }
1402 
1403 int
1404 VFS_SYNC(struct mount *mp, int a, struct kauth_cred *b)
1405 {
1406 	int error;
1407 
1408 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1409 		KERNEL_LOCK(1, NULL);
1410 	}
1411 	error = (*(mp->mnt_op->vfs_sync))(mp, a, b);
1412 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1413 		KERNEL_UNLOCK_ONE(NULL);
1414 	}
1415 
1416 	return error;
1417 }
1418 
1419 int
1420 VFS_FHTOVP(struct mount *mp, struct fid *a, struct vnode **b)
1421 {
1422 	int error;
1423 
1424 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1425 		KERNEL_LOCK(1, NULL);
1426 	}
1427 	error = (*(mp->mnt_op->vfs_fhtovp))(mp, a, b);
1428 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1429 		KERNEL_UNLOCK_ONE(NULL);
1430 	}
1431 
1432 	return error;
1433 }
1434 
1435 int
1436 VFS_VPTOFH(struct vnode *vp, struct fid *a, size_t *b)
1437 {
1438 	int error;
1439 
1440 	if ((vp->v_vflag & VV_MPSAFE) == 0) {
1441 		KERNEL_LOCK(1, NULL);
1442 	}
1443 	error = (*(vp->v_mount->mnt_op->vfs_vptofh))(vp, a, b);
1444 	if ((vp->v_vflag & VV_MPSAFE) == 0) {
1445 		KERNEL_UNLOCK_ONE(NULL);
1446 	}
1447 
1448 	return error;
1449 }
1450 
1451 int
1452 VFS_SNAPSHOT(struct mount *mp, struct vnode *a, struct timespec *b)
1453 {
1454 	int error;
1455 
1456 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1457 		KERNEL_LOCK(1, NULL);
1458 	}
1459 	error = (*(mp->mnt_op->vfs_snapshot))(mp, a, b);
1460 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1461 		KERNEL_UNLOCK_ONE(NULL);
1462 	}
1463 
1464 	return error;
1465 }
1466 
1467 int
1468 VFS_EXTATTRCTL(struct mount *mp, int a, struct vnode *b, int c, const char *d)
1469 {
1470 	int error;
1471 
1472 	KERNEL_LOCK(1, NULL);		/* XXXSMP check ffs */
1473 	error = (*(mp->mnt_op->vfs_extattrctl))(mp, a, b, c, d);
1474 	KERNEL_UNLOCK_ONE(NULL);	/* XXX */
1475 
1476 	return error;
1477 }
1478 
1479 int
1480 VFS_SUSPENDCTL(struct mount *mp, int a)
1481 {
1482 	int error;
1483 
1484 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1485 		KERNEL_LOCK(1, NULL);
1486 	}
1487 	error = (*(mp->mnt_op->vfs_suspendctl))(mp, a);
1488 	if ((mp->mnt_iflag & IMNT_MPSAFE) == 0) {
1489 		KERNEL_UNLOCK_ONE(NULL);
1490 	}
1491 
1492 	return error;
1493 }
1494 
1495 #if defined(DDB) || defined(DEBUGPRINT)
1496 static const char buf_flagbits[] = BUF_FLAGBITS;
1497 
1498 void
1499 vfs_buf_print(struct buf *bp, int full, void (*pr)(const char *, ...))
1500 {
1501 	char bf[1024];
1502 
1503 	(*pr)("  vp %p lblkno 0x%"PRIx64" blkno 0x%"PRIx64" rawblkno 0x%"
1504 	    PRIx64 " dev 0x%x\n",
1505 	    bp->b_vp, bp->b_lblkno, bp->b_blkno, bp->b_rawblkno, bp->b_dev);
1506 
1507 	snprintb(bf, sizeof(bf),
1508 	    buf_flagbits, bp->b_flags | bp->b_oflags | bp->b_cflags);
1509 	(*pr)("  error %d flags 0x%s\n", bp->b_error, bf);
1510 
1511 	(*pr)("  bufsize 0x%lx bcount 0x%lx resid 0x%lx\n",
1512 		  bp->b_bufsize, bp->b_bcount, bp->b_resid);
1513 	(*pr)("  data %p saveaddr %p\n",
1514 		  bp->b_data, bp->b_saveaddr);
1515 	(*pr)("  iodone %p objlock %p\n", bp->b_iodone, bp->b_objlock);
1516 }
1517 
1518 void
1519 vfs_vnode_print(struct vnode *vp, int full, void (*pr)(const char *, ...))
1520 {
1521 
1522 	uvm_object_printit(&vp->v_uobj, full, pr);
1523 	(*pr)("\n");
1524 	vprint_common(vp, "", printf);
1525 	if (full) {
1526 		struct buf *bp;
1527 
1528 		(*pr)("clean bufs:\n");
1529 		LIST_FOREACH(bp, &vp->v_cleanblkhd, b_vnbufs) {
1530 			(*pr)(" bp %p\n", bp);
1531 			vfs_buf_print(bp, full, pr);
1532 		}
1533 
1534 		(*pr)("dirty bufs:\n");
1535 		LIST_FOREACH(bp, &vp->v_dirtyblkhd, b_vnbufs) {
1536 			(*pr)(" bp %p\n", bp);
1537 			vfs_buf_print(bp, full, pr);
1538 		}
1539 	}
1540 }
1541 
1542 void
1543 vfs_vnode_lock_print(void *vlock, int full, void (*pr)(const char *, ...))
1544 {
1545 	struct mount *mp;
1546 	vnode_impl_t *vip;
1547 
1548 	TAILQ_FOREACH(mp, &mountlist, mnt_list) {
1549 		TAILQ_FOREACH(vip, &mp->mnt_vnodelist, vi_mntvnodes) {
1550 			if (&vip->vi_lock != vlock)
1551 				continue;
1552 			vfs_vnode_print(VIMPL_TO_VNODE(vip), full, pr);
1553 		}
1554 	}
1555 }
1556 
1557 void
1558 vfs_mount_print(struct mount *mp, int full, void (*pr)(const char *, ...))
1559 {
1560 	char sbuf[256];
1561 
1562 	(*pr)("vnodecovered = %p data = %p\n",
1563 			mp->mnt_vnodecovered,mp->mnt_data);
1564 
1565 	(*pr)("fs_bshift %d dev_bshift = %d\n",
1566 			mp->mnt_fs_bshift,mp->mnt_dev_bshift);
1567 
1568 	snprintb(sbuf, sizeof(sbuf), __MNT_FLAG_BITS, mp->mnt_flag);
1569 	(*pr)("flag = %s\n", sbuf);
1570 
1571 	snprintb(sbuf, sizeof(sbuf), __IMNT_FLAG_BITS, mp->mnt_iflag);
1572 	(*pr)("iflag = %s\n", sbuf);
1573 
1574 	(*pr)("refcnt = %d unmounting @ %p updating @ %p\n", mp->mnt_refcnt,
1575 	    &mp->mnt_unmounting, &mp->mnt_updating);
1576 
1577 	(*pr)("statvfs cache:\n");
1578 	(*pr)("\tbsize = %lu\n",mp->mnt_stat.f_bsize);
1579 	(*pr)("\tfrsize = %lu\n",mp->mnt_stat.f_frsize);
1580 	(*pr)("\tiosize = %lu\n",mp->mnt_stat.f_iosize);
1581 
1582 	(*pr)("\tblocks = %"PRIu64"\n",mp->mnt_stat.f_blocks);
1583 	(*pr)("\tbfree = %"PRIu64"\n",mp->mnt_stat.f_bfree);
1584 	(*pr)("\tbavail = %"PRIu64"\n",mp->mnt_stat.f_bavail);
1585 	(*pr)("\tbresvd = %"PRIu64"\n",mp->mnt_stat.f_bresvd);
1586 
1587 	(*pr)("\tfiles = %"PRIu64"\n",mp->mnt_stat.f_files);
1588 	(*pr)("\tffree = %"PRIu64"\n",mp->mnt_stat.f_ffree);
1589 	(*pr)("\tfavail = %"PRIu64"\n",mp->mnt_stat.f_favail);
1590 	(*pr)("\tfresvd = %"PRIu64"\n",mp->mnt_stat.f_fresvd);
1591 
1592 	(*pr)("\tf_fsidx = { 0x%"PRIx32", 0x%"PRIx32" }\n",
1593 			mp->mnt_stat.f_fsidx.__fsid_val[0],
1594 			mp->mnt_stat.f_fsidx.__fsid_val[1]);
1595 
1596 	(*pr)("\towner = %"PRIu32"\n",mp->mnt_stat.f_owner);
1597 	(*pr)("\tnamemax = %lu\n",mp->mnt_stat.f_namemax);
1598 
1599 	snprintb(sbuf, sizeof(sbuf), __MNT_FLAG_BITS, mp->mnt_stat.f_flag);
1600 
1601 	(*pr)("\tflag = %s\n",sbuf);
1602 	(*pr)("\tsyncwrites = %" PRIu64 "\n",mp->mnt_stat.f_syncwrites);
1603 	(*pr)("\tasyncwrites = %" PRIu64 "\n",mp->mnt_stat.f_asyncwrites);
1604 	(*pr)("\tsyncreads = %" PRIu64 "\n",mp->mnt_stat.f_syncreads);
1605 	(*pr)("\tasyncreads = %" PRIu64 "\n",mp->mnt_stat.f_asyncreads);
1606 	(*pr)("\tfstypename = %s\n",mp->mnt_stat.f_fstypename);
1607 	(*pr)("\tmntonname = %s\n",mp->mnt_stat.f_mntonname);
1608 	(*pr)("\tmntfromname = %s\n",mp->mnt_stat.f_mntfromname);
1609 
1610 	{
1611 		int cnt = 0;
1612 		vnode_t *vp;
1613 		vnode_impl_t *vip;
1614 		(*pr)("locked vnodes =");
1615 		TAILQ_FOREACH(vip, &mp->mnt_vnodelist, vi_mntvnodes) {
1616 			vp = VIMPL_TO_VNODE(vip);
1617 			if (VOP_ISLOCKED(vp)) {
1618 				if ((++cnt % 6) == 0) {
1619 					(*pr)(" %p,\n\t", vp);
1620 				} else {
1621 					(*pr)(" %p,", vp);
1622 				}
1623 			}
1624 		}
1625 		(*pr)("\n");
1626 	}
1627 
1628 	if (full) {
1629 		int cnt = 0;
1630 		vnode_t *vp;
1631 		vnode_impl_t *vip;
1632 		(*pr)("all vnodes =");
1633 		TAILQ_FOREACH(vip, &mp->mnt_vnodelist, vi_mntvnodes) {
1634 			vp = VIMPL_TO_VNODE(vip);
1635 			if (!TAILQ_NEXT(vip, vi_mntvnodes)) {
1636 				(*pr)(" %p", vp);
1637 			} else if ((++cnt % 6) == 0) {
1638 				(*pr)(" %p,\n\t", vp);
1639 			} else {
1640 				(*pr)(" %p,", vp);
1641 			}
1642 		}
1643 		(*pr)("\n");
1644 	}
1645 }
1646 
1647 /*
1648  * List all of the locked vnodes in the system.
1649  */
1650 void printlockedvnodes(void);
1651 
1652 void
1653 printlockedvnodes(void)
1654 {
1655 	struct mount *mp, *nmp;
1656 	vnode_t *vp;
1657 	vnode_impl_t *vip;
1658 
1659 	printf("Locked vnodes\n");
1660 	mutex_enter(&mountlist_lock);
1661 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
1662 		if (vfs_busy(mp, &nmp)) {
1663 			continue;
1664 		}
1665 		TAILQ_FOREACH(vip, &mp->mnt_vnodelist, vi_mntvnodes) {
1666 			vp = VIMPL_TO_VNODE(vip);
1667 			if (VOP_ISLOCKED(vp))
1668 				vprint(NULL, vp);
1669 		}
1670 		mutex_enter(&mountlist_lock);
1671 		vfs_unbusy(mp, false, &nmp);
1672 	}
1673 	mutex_exit(&mountlist_lock);
1674 }
1675 
1676 #endif /* DDB || DEBUGPRINT */
1677