xref: /freebsd/sys/kern/vfs_default.c (revision 8ecd87a3e7f5503951d37eab034cb330a1c6ec86)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed
8  * to Berkeley by John Heidemann of the UCLA Ficus project.
9  *
10  * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
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  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/bio.h>
43 #include <sys/buf.h>
44 #include <sys/conf.h>
45 #include <sys/event.h>
46 #include <sys/filio.h>
47 #include <sys/kernel.h>
48 #include <sys/limits.h>
49 #include <sys/lock.h>
50 #include <sys/lockf.h>
51 #include <sys/malloc.h>
52 #include <sys/mount.h>
53 #include <sys/namei.h>
54 #include <sys/rwlock.h>
55 #include <sys/fcntl.h>
56 #include <sys/unistd.h>
57 #include <sys/vnode.h>
58 #include <sys/dirent.h>
59 #include <sys/poll.h>
60 #include <sys/stat.h>
61 #include <security/audit/audit.h>
62 #include <sys/priv.h>
63 
64 #include <security/mac/mac_framework.h>
65 
66 #include <vm/vm.h>
67 #include <vm/vm_object.h>
68 #include <vm/vm_extern.h>
69 #include <vm/pmap.h>
70 #include <vm/vm_map.h>
71 #include <vm/vm_page.h>
72 #include <vm/vm_pager.h>
73 #include <vm/vnode_pager.h>
74 
75 static int	vop_nolookup(struct vop_lookup_args *);
76 static int	vop_norename(struct vop_rename_args *);
77 static int	vop_nostrategy(struct vop_strategy_args *);
78 static int	get_next_dirent(struct vnode *vp, struct dirent **dpp,
79 				char *dirbuf, int dirbuflen, off_t *off,
80 				char **cpos, int *len, int *eofflag,
81 				struct thread *td);
82 static int	dirent_exists(struct vnode *vp, const char *dirname,
83 			      struct thread *td);
84 
85 #define DIRENT_MINSIZE (sizeof(struct dirent) - (MAXNAMLEN+1) + 4)
86 
87 static int vop_stdis_text(struct vop_is_text_args *ap);
88 static int vop_stdunset_text(struct vop_unset_text_args *ap);
89 static int vop_stdadd_writecount(struct vop_add_writecount_args *ap);
90 static int vop_stdcopy_file_range(struct vop_copy_file_range_args *ap);
91 static int vop_stdfdatasync(struct vop_fdatasync_args *ap);
92 static int vop_stdgetpages_async(struct vop_getpages_async_args *ap);
93 static int vop_stdread_pgcache(struct vop_read_pgcache_args *ap);
94 static int vop_stdstat(struct vop_stat_args *ap);
95 
96 /*
97  * This vnode table stores what we want to do if the filesystem doesn't
98  * implement a particular VOP.
99  *
100  * If there is no specific entry here, we will return EOPNOTSUPP.
101  *
102  * Note that every filesystem has to implement either vop_access
103  * or vop_accessx; failing to do so will result in immediate crash
104  * due to stack overflow, as vop_stdaccess() calls vop_stdaccessx(),
105  * which calls vop_stdaccess() etc.
106  */
107 
108 struct vop_vector default_vnodeops = {
109 	.vop_default =		NULL,
110 	.vop_bypass =		VOP_EOPNOTSUPP,
111 
112 	.vop_access =		vop_stdaccess,
113 	.vop_accessx =		vop_stdaccessx,
114 	.vop_advise =		vop_stdadvise,
115 	.vop_advlock =		vop_stdadvlock,
116 	.vop_advlockasync =	vop_stdadvlockasync,
117 	.vop_advlockpurge =	vop_stdadvlockpurge,
118 	.vop_allocate =		vop_stdallocate,
119 	.vop_bmap =		vop_stdbmap,
120 	.vop_close =		VOP_NULL,
121 	.vop_fsync =		VOP_NULL,
122 	.vop_stat =		vop_stdstat,
123 	.vop_fdatasync =	vop_stdfdatasync,
124 	.vop_getpages =		vop_stdgetpages,
125 	.vop_getpages_async =	vop_stdgetpages_async,
126 	.vop_getwritemount = 	vop_stdgetwritemount,
127 	.vop_inactive =		VOP_NULL,
128 	.vop_need_inactive =	vop_stdneed_inactive,
129 	.vop_ioctl =		vop_stdioctl,
130 	.vop_kqfilter =		vop_stdkqfilter,
131 	.vop_islocked =		vop_stdislocked,
132 	.vop_lock1 =		vop_stdlock,
133 	.vop_lookup =		vop_nolookup,
134 	.vop_open =		VOP_NULL,
135 	.vop_pathconf =		VOP_EINVAL,
136 	.vop_poll =		vop_nopoll,
137 	.vop_putpages =		vop_stdputpages,
138 	.vop_readlink =		VOP_EINVAL,
139 	.vop_read_pgcache =	vop_stdread_pgcache,
140 	.vop_rename =		vop_norename,
141 	.vop_revoke =		VOP_PANIC,
142 	.vop_strategy =		vop_nostrategy,
143 	.vop_unlock =		vop_stdunlock,
144 	.vop_vptocnp =		vop_stdvptocnp,
145 	.vop_vptofh =		vop_stdvptofh,
146 	.vop_unp_bind =		vop_stdunp_bind,
147 	.vop_unp_connect =	vop_stdunp_connect,
148 	.vop_unp_detach =	vop_stdunp_detach,
149 	.vop_is_text =		vop_stdis_text,
150 	.vop_set_text =		vop_stdset_text,
151 	.vop_unset_text =	vop_stdunset_text,
152 	.vop_add_writecount =	vop_stdadd_writecount,
153 	.vop_copy_file_range =	vop_stdcopy_file_range,
154 };
155 VFS_VOP_VECTOR_REGISTER(default_vnodeops);
156 
157 /*
158  * Series of placeholder functions for various error returns for
159  * VOPs.
160  */
161 
162 int
163 vop_eopnotsupp(struct vop_generic_args *ap)
164 {
165 	/*
166 	printf("vop_notsupp[%s]\n", ap->a_desc->vdesc_name);
167 	*/
168 
169 	return (EOPNOTSUPP);
170 }
171 
172 int
173 vop_ebadf(struct vop_generic_args *ap)
174 {
175 
176 	return (EBADF);
177 }
178 
179 int
180 vop_enotty(struct vop_generic_args *ap)
181 {
182 
183 	return (ENOTTY);
184 }
185 
186 int
187 vop_einval(struct vop_generic_args *ap)
188 {
189 
190 	return (EINVAL);
191 }
192 
193 int
194 vop_enoent(struct vop_generic_args *ap)
195 {
196 
197 	return (ENOENT);
198 }
199 
200 int
201 vop_eagain(struct vop_generic_args *ap)
202 {
203 
204 	return (EAGAIN);
205 }
206 
207 int
208 vop_null(struct vop_generic_args *ap)
209 {
210 
211 	return (0);
212 }
213 
214 /*
215  * Helper function to panic on some bad VOPs in some filesystems.
216  */
217 int
218 vop_panic(struct vop_generic_args *ap)
219 {
220 
221 	panic("filesystem goof: vop_panic[%s]", ap->a_desc->vdesc_name);
222 }
223 
224 /*
225  * vop_std<something> and vop_no<something> are default functions for use by
226  * filesystems that need the "default reasonable" implementation for a
227  * particular operation.
228  *
229  * The documentation for the operations they implement exists (if it exists)
230  * in the VOP_<SOMETHING>(9) manpage (all uppercase).
231  */
232 
233 /*
234  * Default vop for filesystems that do not support name lookup
235  */
236 static int
237 vop_nolookup(ap)
238 	struct vop_lookup_args /* {
239 		struct vnode *a_dvp;
240 		struct vnode **a_vpp;
241 		struct componentname *a_cnp;
242 	} */ *ap;
243 {
244 
245 	*ap->a_vpp = NULL;
246 	return (ENOTDIR);
247 }
248 
249 /*
250  * vop_norename:
251  *
252  * Handle unlock and reference counting for arguments of vop_rename
253  * for filesystems that do not implement rename operation.
254  */
255 static int
256 vop_norename(struct vop_rename_args *ap)
257 {
258 
259 	vop_rename_fail(ap);
260 	return (EOPNOTSUPP);
261 }
262 
263 /*
264  *	vop_nostrategy:
265  *
266  *	Strategy routine for VFS devices that have none.
267  *
268  *	BIO_ERROR and B_INVAL must be cleared prior to calling any strategy
269  *	routine.  Typically this is done for a BIO_READ strategy call.
270  *	Typically B_INVAL is assumed to already be clear prior to a write
271  *	and should not be cleared manually unless you just made the buffer
272  *	invalid.  BIO_ERROR should be cleared either way.
273  */
274 
275 static int
276 vop_nostrategy (struct vop_strategy_args *ap)
277 {
278 	printf("No strategy for buffer at %p\n", ap->a_bp);
279 	vn_printf(ap->a_vp, "vnode ");
280 	ap->a_bp->b_ioflags |= BIO_ERROR;
281 	ap->a_bp->b_error = EOPNOTSUPP;
282 	bufdone(ap->a_bp);
283 	return (EOPNOTSUPP);
284 }
285 
286 static int
287 get_next_dirent(struct vnode *vp, struct dirent **dpp, char *dirbuf,
288 		int dirbuflen, off_t *off, char **cpos, int *len,
289 		int *eofflag, struct thread *td)
290 {
291 	int error, reclen;
292 	struct uio uio;
293 	struct iovec iov;
294 	struct dirent *dp;
295 
296 	KASSERT(VOP_ISLOCKED(vp), ("vp %p is not locked", vp));
297 	KASSERT(vp->v_type == VDIR, ("vp %p is not a directory", vp));
298 
299 	if (*len == 0) {
300 		iov.iov_base = dirbuf;
301 		iov.iov_len = dirbuflen;
302 
303 		uio.uio_iov = &iov;
304 		uio.uio_iovcnt = 1;
305 		uio.uio_offset = *off;
306 		uio.uio_resid = dirbuflen;
307 		uio.uio_segflg = UIO_SYSSPACE;
308 		uio.uio_rw = UIO_READ;
309 		uio.uio_td = td;
310 
311 		*eofflag = 0;
312 
313 #ifdef MAC
314 		error = mac_vnode_check_readdir(td->td_ucred, vp);
315 		if (error == 0)
316 #endif
317 			error = VOP_READDIR(vp, &uio, td->td_ucred, eofflag,
318 		    		NULL, NULL);
319 		if (error)
320 			return (error);
321 
322 		*off = uio.uio_offset;
323 
324 		*cpos = dirbuf;
325 		*len = (dirbuflen - uio.uio_resid);
326 
327 		if (*len == 0)
328 			return (ENOENT);
329 	}
330 
331 	dp = (struct dirent *)(*cpos);
332 	reclen = dp->d_reclen;
333 	*dpp = dp;
334 
335 	/* check for malformed directory.. */
336 	if (reclen < DIRENT_MINSIZE)
337 		return (EINVAL);
338 
339 	*cpos += reclen;
340 	*len -= reclen;
341 
342 	return (0);
343 }
344 
345 /*
346  * Check if a named file exists in a given directory vnode.
347  */
348 static int
349 dirent_exists(struct vnode *vp, const char *dirname, struct thread *td)
350 {
351 	char *dirbuf, *cpos;
352 	int error, eofflag, dirbuflen, len, found;
353 	off_t off;
354 	struct dirent *dp;
355 	struct vattr va;
356 
357 	KASSERT(VOP_ISLOCKED(vp), ("vp %p is not locked", vp));
358 	KASSERT(vp->v_type == VDIR, ("vp %p is not a directory", vp));
359 
360 	found = 0;
361 
362 	error = VOP_GETATTR(vp, &va, td->td_ucred);
363 	if (error)
364 		return (found);
365 
366 	dirbuflen = DEV_BSIZE;
367 	if (dirbuflen < va.va_blocksize)
368 		dirbuflen = va.va_blocksize;
369 	dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK);
370 
371 	off = 0;
372 	len = 0;
373 	do {
374 		error = get_next_dirent(vp, &dp, dirbuf, dirbuflen, &off,
375 					&cpos, &len, &eofflag, td);
376 		if (error)
377 			goto out;
378 
379 		if (dp->d_type != DT_WHT && dp->d_fileno != 0 &&
380 		    strcmp(dp->d_name, dirname) == 0) {
381 			found = 1;
382 			goto out;
383 		}
384 	} while (len > 0 || !eofflag);
385 
386 out:
387 	free(dirbuf, M_TEMP);
388 	return (found);
389 }
390 
391 int
392 vop_stdaccess(struct vop_access_args *ap)
393 {
394 
395 	KASSERT((ap->a_accmode & ~(VEXEC | VWRITE | VREAD | VADMIN |
396 	    VAPPEND)) == 0, ("invalid bit in accmode"));
397 
398 	return (VOP_ACCESSX(ap->a_vp, ap->a_accmode, ap->a_cred, ap->a_td));
399 }
400 
401 int
402 vop_stdaccessx(struct vop_accessx_args *ap)
403 {
404 	int error;
405 	accmode_t accmode = ap->a_accmode;
406 
407 	error = vfs_unixify_accmode(&accmode);
408 	if (error != 0)
409 		return (error);
410 
411 	if (accmode == 0)
412 		return (0);
413 
414 	return (VOP_ACCESS(ap->a_vp, accmode, ap->a_cred, ap->a_td));
415 }
416 
417 /*
418  * Advisory record locking support
419  */
420 int
421 vop_stdadvlock(struct vop_advlock_args *ap)
422 {
423 	struct vnode *vp;
424 	struct vattr vattr;
425 	int error;
426 
427 	vp = ap->a_vp;
428 	if (ap->a_fl->l_whence == SEEK_END) {
429 		/*
430 		 * The NFSv4 server must avoid doing a vn_lock() here, since it
431 		 * can deadlock the nfsd threads, due to a LOR.  Fortunately
432 		 * the NFSv4 server always uses SEEK_SET and this code is
433 		 * only required for the SEEK_END case.
434 		 */
435 		vn_lock(vp, LK_SHARED | LK_RETRY);
436 		error = VOP_GETATTR(vp, &vattr, curthread->td_ucred);
437 		VOP_UNLOCK(vp);
438 		if (error)
439 			return (error);
440 	} else
441 		vattr.va_size = 0;
442 
443 	return (lf_advlock(ap, &(vp->v_lockf), vattr.va_size));
444 }
445 
446 int
447 vop_stdadvlockasync(struct vop_advlockasync_args *ap)
448 {
449 	struct vnode *vp;
450 	struct vattr vattr;
451 	int error;
452 
453 	vp = ap->a_vp;
454 	if (ap->a_fl->l_whence == SEEK_END) {
455 		/* The size argument is only needed for SEEK_END. */
456 		vn_lock(vp, LK_SHARED | LK_RETRY);
457 		error = VOP_GETATTR(vp, &vattr, curthread->td_ucred);
458 		VOP_UNLOCK(vp);
459 		if (error)
460 			return (error);
461 	} else
462 		vattr.va_size = 0;
463 
464 	return (lf_advlockasync(ap, &(vp->v_lockf), vattr.va_size));
465 }
466 
467 int
468 vop_stdadvlockpurge(struct vop_advlockpurge_args *ap)
469 {
470 	struct vnode *vp;
471 
472 	vp = ap->a_vp;
473 	lf_purgelocks(vp, &vp->v_lockf);
474 	return (0);
475 }
476 
477 /*
478  * vop_stdpathconf:
479  *
480  * Standard implementation of POSIX pathconf, to get information about limits
481  * for a filesystem.
482  * Override per filesystem for the case where the filesystem has smaller
483  * limits.
484  */
485 int
486 vop_stdpathconf(ap)
487 	struct vop_pathconf_args /* {
488 	struct vnode *a_vp;
489 	int a_name;
490 	int *a_retval;
491 	} */ *ap;
492 {
493 
494 	switch (ap->a_name) {
495 		case _PC_ASYNC_IO:
496 			*ap->a_retval = _POSIX_ASYNCHRONOUS_IO;
497 			return (0);
498 		case _PC_PATH_MAX:
499 			*ap->a_retval = PATH_MAX;
500 			return (0);
501 		case _PC_ACL_EXTENDED:
502 		case _PC_ACL_NFS4:
503 		case _PC_CAP_PRESENT:
504 		case _PC_INF_PRESENT:
505 		case _PC_MAC_PRESENT:
506 			*ap->a_retval = 0;
507 			return (0);
508 		default:
509 			return (EINVAL);
510 	}
511 	/* NOTREACHED */
512 }
513 
514 /*
515  * Standard lock, unlock and islocked functions.
516  */
517 int
518 vop_stdlock(ap)
519 	struct vop_lock1_args /* {
520 		struct vnode *a_vp;
521 		int a_flags;
522 		char *file;
523 		int line;
524 	} */ *ap;
525 {
526 	struct vnode *vp = ap->a_vp;
527 	struct mtx *ilk;
528 
529 	ilk = VI_MTX(vp);
530 	return (lockmgr_lock_flags(vp->v_vnlock, ap->a_flags,
531 	    &ilk->lock_object, ap->a_file, ap->a_line));
532 }
533 
534 /* See above. */
535 int
536 vop_stdunlock(ap)
537 	struct vop_unlock_args /* {
538 		struct vnode *a_vp;
539 	} */ *ap;
540 {
541 	struct vnode *vp = ap->a_vp;
542 
543 	return (lockmgr_unlock(vp->v_vnlock));
544 }
545 
546 /* See above. */
547 int
548 vop_stdislocked(ap)
549 	struct vop_islocked_args /* {
550 		struct vnode *a_vp;
551 	} */ *ap;
552 {
553 
554 	return (lockstatus(ap->a_vp->v_vnlock));
555 }
556 
557 /*
558  * Variants of the above set.
559  *
560  * Differences are:
561  * - shared locking disablement is not supported
562  * - v_vnlock pointer is not honored
563  */
564 int
565 vop_lock(ap)
566 	struct vop_lock1_args /* {
567 		struct vnode *a_vp;
568 		int a_flags;
569 		char *file;
570 		int line;
571 	} */ *ap;
572 {
573 	struct vnode *vp = ap->a_vp;
574 	int flags = ap->a_flags;
575 	struct mtx *ilk;
576 
577 	MPASS(vp->v_vnlock == &vp->v_lock);
578 
579 	if (__predict_false((flags & ~(LK_TYPE_MASK | LK_NODDLKTREAT | LK_RETRY)) != 0))
580 		goto other;
581 
582 	switch (flags & LK_TYPE_MASK) {
583 	case LK_SHARED:
584 		return (lockmgr_slock(&vp->v_lock, flags, ap->a_file, ap->a_line));
585 	case LK_EXCLUSIVE:
586 		return (lockmgr_xlock(&vp->v_lock, flags, ap->a_file, ap->a_line));
587 	}
588 other:
589 	ilk = VI_MTX(vp);
590 	return (lockmgr_lock_flags(&vp->v_lock, flags,
591 	    &ilk->lock_object, ap->a_file, ap->a_line));
592 }
593 
594 int
595 vop_unlock(ap)
596 	struct vop_unlock_args /* {
597 		struct vnode *a_vp;
598 	} */ *ap;
599 {
600 	struct vnode *vp = ap->a_vp;
601 
602 	MPASS(vp->v_vnlock == &vp->v_lock);
603 
604 	return (lockmgr_unlock(&vp->v_lock));
605 }
606 
607 int
608 vop_islocked(ap)
609 	struct vop_islocked_args /* {
610 		struct vnode *a_vp;
611 	} */ *ap;
612 {
613 	struct vnode *vp = ap->a_vp;
614 
615 	MPASS(vp->v_vnlock == &vp->v_lock);
616 
617 	return (lockstatus(&vp->v_lock));
618 }
619 
620 /*
621  * Return true for select/poll.
622  */
623 int
624 vop_nopoll(ap)
625 	struct vop_poll_args /* {
626 		struct vnode *a_vp;
627 		int  a_events;
628 		struct ucred *a_cred;
629 		struct thread *a_td;
630 	} */ *ap;
631 {
632 
633 	if (ap->a_events & ~POLLSTANDARD)
634 		return (POLLNVAL);
635 	return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
636 }
637 
638 /*
639  * Implement poll for local filesystems that support it.
640  */
641 int
642 vop_stdpoll(ap)
643 	struct vop_poll_args /* {
644 		struct vnode *a_vp;
645 		int  a_events;
646 		struct ucred *a_cred;
647 		struct thread *a_td;
648 	} */ *ap;
649 {
650 	if (ap->a_events & ~POLLSTANDARD)
651 		return (vn_pollrecord(ap->a_vp, ap->a_td, ap->a_events));
652 	return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
653 }
654 
655 /*
656  * Return our mount point, as we will take charge of the writes.
657  */
658 int
659 vop_stdgetwritemount(ap)
660 	struct vop_getwritemount_args /* {
661 		struct vnode *a_vp;
662 		struct mount **a_mpp;
663 	} */ *ap;
664 {
665 	struct mount *mp;
666 	struct vnode *vp;
667 
668 	/*
669 	 * Note that having a reference does not prevent forced unmount from
670 	 * setting ->v_mount to NULL after the lock gets released. This is of
671 	 * no consequence for typical consumers (most notably vn_start_write)
672 	 * since in this case the vnode is VIRF_DOOMED. Unmount might have
673 	 * progressed far enough that its completion is only delayed by the
674 	 * reference obtained here. The consumer only needs to concern itself
675 	 * with releasing it.
676 	 */
677 	vp = ap->a_vp;
678 	mp = vp->v_mount;
679 	if (mp == NULL) {
680 		*(ap->a_mpp) = NULL;
681 		return (0);
682 	}
683 	if (vfs_op_thread_enter(mp)) {
684 		if (mp == vp->v_mount) {
685 			vfs_mp_count_add_pcpu(mp, ref, 1);
686 			vfs_op_thread_exit(mp);
687 		} else {
688 			vfs_op_thread_exit(mp);
689 			mp = NULL;
690 		}
691 	} else {
692 		MNT_ILOCK(mp);
693 		if (mp == vp->v_mount) {
694 			MNT_REF(mp);
695 			MNT_IUNLOCK(mp);
696 		} else {
697 			MNT_IUNLOCK(mp);
698 			mp = NULL;
699 		}
700 	}
701 	*(ap->a_mpp) = mp;
702 	return (0);
703 }
704 
705 /*
706  * If the file system doesn't implement VOP_BMAP, then return sensible defaults:
707  * - Return the vnode's bufobj instead of any underlying device's bufobj
708  * - Calculate the physical block number as if there were equal size
709  *   consecutive blocks, but
710  * - Report no contiguous runs of blocks.
711  */
712 int
713 vop_stdbmap(ap)
714 	struct vop_bmap_args /* {
715 		struct vnode *a_vp;
716 		daddr_t  a_bn;
717 		struct bufobj **a_bop;
718 		daddr_t *a_bnp;
719 		int *a_runp;
720 		int *a_runb;
721 	} */ *ap;
722 {
723 
724 	if (ap->a_bop != NULL)
725 		*ap->a_bop = &ap->a_vp->v_bufobj;
726 	if (ap->a_bnp != NULL)
727 		*ap->a_bnp = ap->a_bn * btodb(ap->a_vp->v_mount->mnt_stat.f_iosize);
728 	if (ap->a_runp != NULL)
729 		*ap->a_runp = 0;
730 	if (ap->a_runb != NULL)
731 		*ap->a_runb = 0;
732 	return (0);
733 }
734 
735 int
736 vop_stdfsync(ap)
737 	struct vop_fsync_args /* {
738 		struct vnode *a_vp;
739 		int a_waitfor;
740 		struct thread *a_td;
741 	} */ *ap;
742 {
743 
744 	return (vn_fsync_buf(ap->a_vp, ap->a_waitfor));
745 }
746 
747 static int
748 vop_stdfdatasync(struct vop_fdatasync_args *ap)
749 {
750 
751 	return (VOP_FSYNC(ap->a_vp, MNT_WAIT, ap->a_td));
752 }
753 
754 int
755 vop_stdfdatasync_buf(struct vop_fdatasync_args *ap)
756 {
757 
758 	return (vn_fsync_buf(ap->a_vp, MNT_WAIT));
759 }
760 
761 /* XXX Needs good comment and more info in the manpage (VOP_GETPAGES(9)). */
762 int
763 vop_stdgetpages(ap)
764 	struct vop_getpages_args /* {
765 		struct vnode *a_vp;
766 		vm_page_t *a_m;
767 		int a_count;
768 		int *a_rbehind;
769 		int *a_rahead;
770 	} */ *ap;
771 {
772 
773 	return vnode_pager_generic_getpages(ap->a_vp, ap->a_m,
774 	    ap->a_count, ap->a_rbehind, ap->a_rahead, NULL, NULL);
775 }
776 
777 static int
778 vop_stdgetpages_async(struct vop_getpages_async_args *ap)
779 {
780 	int error;
781 
782 	error = VOP_GETPAGES(ap->a_vp, ap->a_m, ap->a_count, ap->a_rbehind,
783 	    ap->a_rahead);
784 	if (ap->a_iodone != NULL)
785 		ap->a_iodone(ap->a_arg, ap->a_m, ap->a_count, error);
786 	return (error);
787 }
788 
789 int
790 vop_stdkqfilter(struct vop_kqfilter_args *ap)
791 {
792 	return vfs_kqfilter(ap);
793 }
794 
795 /* XXX Needs good comment and more info in the manpage (VOP_PUTPAGES(9)). */
796 int
797 vop_stdputpages(ap)
798 	struct vop_putpages_args /* {
799 		struct vnode *a_vp;
800 		vm_page_t *a_m;
801 		int a_count;
802 		int a_sync;
803 		int *a_rtvals;
804 	} */ *ap;
805 {
806 
807 	return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count,
808 	     ap->a_sync, ap->a_rtvals);
809 }
810 
811 int
812 vop_stdvptofh(struct vop_vptofh_args *ap)
813 {
814 	return (EOPNOTSUPP);
815 }
816 
817 int
818 vop_stdvptocnp(struct vop_vptocnp_args *ap)
819 {
820 	struct vnode *vp = ap->a_vp;
821 	struct vnode **dvp = ap->a_vpp;
822 	struct ucred *cred;
823 	char *buf = ap->a_buf;
824 	size_t *buflen = ap->a_buflen;
825 	char *dirbuf, *cpos;
826 	int i, error, eofflag, dirbuflen, flags, locked, len, covered;
827 	off_t off;
828 	ino_t fileno;
829 	struct vattr va;
830 	struct nameidata nd;
831 	struct thread *td;
832 	struct dirent *dp;
833 	struct vnode *mvp;
834 
835 	i = *buflen;
836 	error = 0;
837 	covered = 0;
838 	td = curthread;
839 	cred = td->td_ucred;
840 
841 	if (vp->v_type != VDIR)
842 		return (ENOENT);
843 
844 	error = VOP_GETATTR(vp, &va, cred);
845 	if (error)
846 		return (error);
847 
848 	VREF(vp);
849 	locked = VOP_ISLOCKED(vp);
850 	VOP_UNLOCK(vp);
851 	NDINIT_ATVP(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, UIO_SYSSPACE,
852 	    "..", vp, td);
853 	flags = FREAD;
854 	error = vn_open_cred(&nd, &flags, 0, VN_OPEN_NOAUDIT, cred, NULL);
855 	if (error) {
856 		vn_lock(vp, locked | LK_RETRY);
857 		return (error);
858 	}
859 	NDFREE(&nd, NDF_ONLY_PNBUF);
860 
861 	mvp = *dvp = nd.ni_vp;
862 
863 	if (vp->v_mount != (*dvp)->v_mount &&
864 	    ((*dvp)->v_vflag & VV_ROOT) &&
865 	    ((*dvp)->v_mount->mnt_flag & MNT_UNION)) {
866 		*dvp = (*dvp)->v_mount->mnt_vnodecovered;
867 		VREF(mvp);
868 		VOP_UNLOCK(mvp);
869 		vn_close(mvp, FREAD, cred, td);
870 		VREF(*dvp);
871 		vn_lock(*dvp, LK_SHARED | LK_RETRY);
872 		covered = 1;
873 	}
874 
875 	fileno = va.va_fileid;
876 
877 	dirbuflen = DEV_BSIZE;
878 	if (dirbuflen < va.va_blocksize)
879 		dirbuflen = va.va_blocksize;
880 	dirbuf = (char *)malloc(dirbuflen, M_TEMP, M_WAITOK);
881 
882 	if ((*dvp)->v_type != VDIR) {
883 		error = ENOENT;
884 		goto out;
885 	}
886 
887 	off = 0;
888 	len = 0;
889 	do {
890 		/* call VOP_READDIR of parent */
891 		error = get_next_dirent(*dvp, &dp, dirbuf, dirbuflen, &off,
892 					&cpos, &len, &eofflag, td);
893 		if (error)
894 			goto out;
895 
896 		if ((dp->d_type != DT_WHT) &&
897 		    (dp->d_fileno == fileno)) {
898 			if (covered) {
899 				VOP_UNLOCK(*dvp);
900 				vn_lock(mvp, LK_SHARED | LK_RETRY);
901 				if (dirent_exists(mvp, dp->d_name, td)) {
902 					error = ENOENT;
903 					VOP_UNLOCK(mvp);
904 					vn_lock(*dvp, LK_SHARED | LK_RETRY);
905 					goto out;
906 				}
907 				VOP_UNLOCK(mvp);
908 				vn_lock(*dvp, LK_SHARED | LK_RETRY);
909 			}
910 			i -= dp->d_namlen;
911 
912 			if (i < 0) {
913 				error = ENOMEM;
914 				goto out;
915 			}
916 			if (dp->d_namlen == 1 && dp->d_name[0] == '.') {
917 				error = ENOENT;
918 			} else {
919 				bcopy(dp->d_name, buf + i, dp->d_namlen);
920 				error = 0;
921 			}
922 			goto out;
923 		}
924 	} while (len > 0 || !eofflag);
925 	error = ENOENT;
926 
927 out:
928 	free(dirbuf, M_TEMP);
929 	if (!error) {
930 		*buflen = i;
931 		vref(*dvp);
932 	}
933 	if (covered) {
934 		vput(*dvp);
935 		vrele(mvp);
936 	} else {
937 		VOP_UNLOCK(mvp);
938 		vn_close(mvp, FREAD, cred, td);
939 	}
940 	vn_lock(vp, locked | LK_RETRY);
941 	return (error);
942 }
943 
944 int
945 vop_stdallocate(struct vop_allocate_args *ap)
946 {
947 #ifdef __notyet__
948 	struct statfs *sfs;
949 	off_t maxfilesize = 0;
950 #endif
951 	struct iovec aiov;
952 	struct vattr vattr, *vap;
953 	struct uio auio;
954 	off_t fsize, len, cur, offset;
955 	uint8_t *buf;
956 	struct thread *td;
957 	struct vnode *vp;
958 	size_t iosize;
959 	int error;
960 
961 	buf = NULL;
962 	error = 0;
963 	td = curthread;
964 	vap = &vattr;
965 	vp = ap->a_vp;
966 	len = *ap->a_len;
967 	offset = *ap->a_offset;
968 
969 	error = VOP_GETATTR(vp, vap, td->td_ucred);
970 	if (error != 0)
971 		goto out;
972 	fsize = vap->va_size;
973 	iosize = vap->va_blocksize;
974 	if (iosize == 0)
975 		iosize = BLKDEV_IOSIZE;
976 	if (iosize > MAXPHYS)
977 		iosize = MAXPHYS;
978 	buf = malloc(iosize, M_TEMP, M_WAITOK);
979 
980 #ifdef __notyet__
981 	/*
982 	 * Check if the filesystem sets f_maxfilesize; if not use
983 	 * VOP_SETATTR to perform the check.
984 	 */
985 	sfs = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
986 	error = VFS_STATFS(vp->v_mount, sfs, td);
987 	if (error == 0)
988 		maxfilesize = sfs->f_maxfilesize;
989 	free(sfs, M_STATFS);
990 	if (error != 0)
991 		goto out;
992 	if (maxfilesize) {
993 		if (offset > maxfilesize || len > maxfilesize ||
994 		    offset + len > maxfilesize) {
995 			error = EFBIG;
996 			goto out;
997 		}
998 	} else
999 #endif
1000 	if (offset + len > vap->va_size) {
1001 		/*
1002 		 * Test offset + len against the filesystem's maxfilesize.
1003 		 */
1004 		VATTR_NULL(vap);
1005 		vap->va_size = offset + len;
1006 		error = VOP_SETATTR(vp, vap, td->td_ucred);
1007 		if (error != 0)
1008 			goto out;
1009 		VATTR_NULL(vap);
1010 		vap->va_size = fsize;
1011 		error = VOP_SETATTR(vp, vap, td->td_ucred);
1012 		if (error != 0)
1013 			goto out;
1014 	}
1015 
1016 	for (;;) {
1017 		/*
1018 		 * Read and write back anything below the nominal file
1019 		 * size.  There's currently no way outside the filesystem
1020 		 * to know whether this area is sparse or not.
1021 		 */
1022 		cur = iosize;
1023 		if ((offset % iosize) != 0)
1024 			cur -= (offset % iosize);
1025 		if (cur > len)
1026 			cur = len;
1027 		if (offset < fsize) {
1028 			aiov.iov_base = buf;
1029 			aiov.iov_len = cur;
1030 			auio.uio_iov = &aiov;
1031 			auio.uio_iovcnt = 1;
1032 			auio.uio_offset = offset;
1033 			auio.uio_resid = cur;
1034 			auio.uio_segflg = UIO_SYSSPACE;
1035 			auio.uio_rw = UIO_READ;
1036 			auio.uio_td = td;
1037 			error = VOP_READ(vp, &auio, 0, td->td_ucred);
1038 			if (error != 0)
1039 				break;
1040 			if (auio.uio_resid > 0) {
1041 				bzero(buf + cur - auio.uio_resid,
1042 				    auio.uio_resid);
1043 			}
1044 		} else {
1045 			bzero(buf, cur);
1046 		}
1047 
1048 		aiov.iov_base = buf;
1049 		aiov.iov_len = cur;
1050 		auio.uio_iov = &aiov;
1051 		auio.uio_iovcnt = 1;
1052 		auio.uio_offset = offset;
1053 		auio.uio_resid = cur;
1054 		auio.uio_segflg = UIO_SYSSPACE;
1055 		auio.uio_rw = UIO_WRITE;
1056 		auio.uio_td = td;
1057 
1058 		error = VOP_WRITE(vp, &auio, 0, td->td_ucred);
1059 		if (error != 0)
1060 			break;
1061 
1062 		len -= cur;
1063 		offset += cur;
1064 		if (len == 0)
1065 			break;
1066 		if (should_yield())
1067 			break;
1068 	}
1069 
1070  out:
1071 	*ap->a_len = len;
1072 	*ap->a_offset = offset;
1073 	free(buf, M_TEMP);
1074 	return (error);
1075 }
1076 
1077 int
1078 vop_stdadvise(struct vop_advise_args *ap)
1079 {
1080 	struct vnode *vp;
1081 	struct bufobj *bo;
1082 	daddr_t startn, endn;
1083 	off_t bstart, bend, start, end;
1084 	int bsize, error;
1085 
1086 	vp = ap->a_vp;
1087 	switch (ap->a_advice) {
1088 	case POSIX_FADV_WILLNEED:
1089 		/*
1090 		 * Do nothing for now.  Filesystems should provide a
1091 		 * custom method which starts an asynchronous read of
1092 		 * the requested region.
1093 		 */
1094 		error = 0;
1095 		break;
1096 	case POSIX_FADV_DONTNEED:
1097 		error = 0;
1098 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1099 		if (VN_IS_DOOMED(vp)) {
1100 			VOP_UNLOCK(vp);
1101 			break;
1102 		}
1103 
1104 		/*
1105 		 * Round to block boundaries (and later possibly further to
1106 		 * page boundaries).  Applications cannot reasonably be aware
1107 		 * of the boundaries, and the rounding must be to expand at
1108 		 * both extremities to cover enough.  It still doesn't cover
1109 		 * read-ahead.  For partial blocks, this gives unnecessary
1110 		 * discarding of buffers but is efficient enough since the
1111 		 * pages usually remain in VMIO for some time.
1112 		 */
1113 		bsize = vp->v_bufobj.bo_bsize;
1114 		bstart = rounddown(ap->a_start, bsize);
1115 		bend = roundup(ap->a_end, bsize);
1116 
1117 		/*
1118 		 * Deactivate pages in the specified range from the backing VM
1119 		 * object.  Pages that are resident in the buffer cache will
1120 		 * remain wired until their corresponding buffers are released
1121 		 * below.
1122 		 */
1123 		if (vp->v_object != NULL) {
1124 			start = trunc_page(bstart);
1125 			end = round_page(bend);
1126 			VM_OBJECT_RLOCK(vp->v_object);
1127 			vm_object_page_noreuse(vp->v_object, OFF_TO_IDX(start),
1128 			    OFF_TO_IDX(end));
1129 			VM_OBJECT_RUNLOCK(vp->v_object);
1130 		}
1131 
1132 		bo = &vp->v_bufobj;
1133 		BO_RLOCK(bo);
1134 		startn = bstart / bsize;
1135 		endn = bend / bsize;
1136 		error = bnoreuselist(&bo->bo_clean, bo, startn, endn);
1137 		if (error == 0)
1138 			error = bnoreuselist(&bo->bo_dirty, bo, startn, endn);
1139 		BO_RUNLOCK(bo);
1140 		VOP_UNLOCK(vp);
1141 		break;
1142 	default:
1143 		error = EINVAL;
1144 		break;
1145 	}
1146 	return (error);
1147 }
1148 
1149 int
1150 vop_stdunp_bind(struct vop_unp_bind_args *ap)
1151 {
1152 
1153 	ap->a_vp->v_unpcb = ap->a_unpcb;
1154 	return (0);
1155 }
1156 
1157 int
1158 vop_stdunp_connect(struct vop_unp_connect_args *ap)
1159 {
1160 
1161 	*ap->a_unpcb = ap->a_vp->v_unpcb;
1162 	return (0);
1163 }
1164 
1165 int
1166 vop_stdunp_detach(struct vop_unp_detach_args *ap)
1167 {
1168 
1169 	ap->a_vp->v_unpcb = NULL;
1170 	return (0);
1171 }
1172 
1173 static int
1174 vop_stdis_text(struct vop_is_text_args *ap)
1175 {
1176 
1177 	return (ap->a_vp->v_writecount < 0);
1178 }
1179 
1180 int
1181 vop_stdset_text(struct vop_set_text_args *ap)
1182 {
1183 	struct vnode *vp;
1184 	struct mount *mp;
1185 	int error;
1186 
1187 	vp = ap->a_vp;
1188 	VI_LOCK(vp);
1189 	if (vp->v_writecount > 0) {
1190 		error = ETXTBSY;
1191 	} else {
1192 		/*
1193 		 * If requested by fs, keep a use reference to the
1194 		 * vnode until the last text reference is released.
1195 		 */
1196 		mp = vp->v_mount;
1197 		if (mp != NULL && (mp->mnt_kern_flag & MNTK_TEXT_REFS) != 0 &&
1198 		    vp->v_writecount == 0) {
1199 			VNPASS((vp->v_iflag & VI_TEXT_REF) == 0, vp);
1200 			vp->v_iflag |= VI_TEXT_REF;
1201 			vrefl(vp);
1202 		}
1203 
1204 		vp->v_writecount--;
1205 		error = 0;
1206 	}
1207 	VI_UNLOCK(vp);
1208 	return (error);
1209 }
1210 
1211 static int
1212 vop_stdunset_text(struct vop_unset_text_args *ap)
1213 {
1214 	struct vnode *vp;
1215 	int error;
1216 	bool last;
1217 
1218 	vp = ap->a_vp;
1219 	last = false;
1220 	VI_LOCK(vp);
1221 	if (vp->v_writecount < 0) {
1222 		if ((vp->v_iflag & VI_TEXT_REF) != 0 &&
1223 		    vp->v_writecount == -1) {
1224 			last = true;
1225 			vp->v_iflag &= ~VI_TEXT_REF;
1226 		}
1227 		vp->v_writecount++;
1228 		error = 0;
1229 	} else {
1230 		error = EINVAL;
1231 	}
1232 	VI_UNLOCK(vp);
1233 	if (last)
1234 		vunref(vp);
1235 	return (error);
1236 }
1237 
1238 static int
1239 vop_stdadd_writecount(struct vop_add_writecount_args *ap)
1240 {
1241 	struct vnode *vp;
1242 	struct mount *mp;
1243 	int error;
1244 
1245 	vp = ap->a_vp;
1246 	VI_LOCK_FLAGS(vp, MTX_DUPOK);
1247 	if (vp->v_writecount < 0) {
1248 		error = ETXTBSY;
1249 	} else {
1250 		VNASSERT(vp->v_writecount + ap->a_inc >= 0, vp,
1251 		    ("neg writecount increment %d", ap->a_inc));
1252 		if (vp->v_writecount == 0) {
1253 			mp = vp->v_mount;
1254 			if (mp != NULL && (mp->mnt_kern_flag & MNTK_NOMSYNC) == 0)
1255 				vlazy(vp);
1256 		}
1257 		vp->v_writecount += ap->a_inc;
1258 		error = 0;
1259 	}
1260 	VI_UNLOCK(vp);
1261 	return (error);
1262 }
1263 
1264 int
1265 vop_stdneed_inactive(struct vop_need_inactive_args *ap)
1266 {
1267 
1268 	return (1);
1269 }
1270 
1271 int
1272 vop_stdioctl(struct vop_ioctl_args *ap)
1273 {
1274 	struct vnode *vp;
1275 	struct vattr va;
1276 	off_t *offp;
1277 	int error;
1278 
1279 	switch (ap->a_command) {
1280 	case FIOSEEKDATA:
1281 	case FIOSEEKHOLE:
1282 		vp = ap->a_vp;
1283 		error = vn_lock(vp, LK_SHARED);
1284 		if (error != 0)
1285 			return (EBADF);
1286 		if (vp->v_type == VREG)
1287 			error = VOP_GETATTR(vp, &va, ap->a_cred);
1288 		else
1289 			error = ENOTTY;
1290 		if (error == 0) {
1291 			offp = ap->a_data;
1292 			if (*offp < 0 || *offp >= va.va_size)
1293 				error = ENXIO;
1294 			else if (ap->a_command == FIOSEEKHOLE)
1295 				*offp = va.va_size;
1296 		}
1297 		VOP_UNLOCK(vp);
1298 		break;
1299 	default:
1300 		error = ENOTTY;
1301 		break;
1302 	}
1303 	return (error);
1304 }
1305 
1306 /*
1307  * vfs default ops
1308  * used to fill the vfs function table to get reasonable default return values.
1309  */
1310 int
1311 vfs_stdroot (mp, flags, vpp)
1312 	struct mount *mp;
1313 	int flags;
1314 	struct vnode **vpp;
1315 {
1316 
1317 	return (EOPNOTSUPP);
1318 }
1319 
1320 int
1321 vfs_stdstatfs (mp, sbp)
1322 	struct mount *mp;
1323 	struct statfs *sbp;
1324 {
1325 
1326 	return (EOPNOTSUPP);
1327 }
1328 
1329 int
1330 vfs_stdquotactl (mp, cmds, uid, arg)
1331 	struct mount *mp;
1332 	int cmds;
1333 	uid_t uid;
1334 	void *arg;
1335 {
1336 
1337 	return (EOPNOTSUPP);
1338 }
1339 
1340 int
1341 vfs_stdsync(mp, waitfor)
1342 	struct mount *mp;
1343 	int waitfor;
1344 {
1345 	struct vnode *vp, *mvp;
1346 	struct thread *td;
1347 	int error, lockreq, allerror = 0;
1348 
1349 	td = curthread;
1350 	lockreq = LK_EXCLUSIVE | LK_INTERLOCK;
1351 	if (waitfor != MNT_WAIT)
1352 		lockreq |= LK_NOWAIT;
1353 	/*
1354 	 * Force stale buffer cache information to be flushed.
1355 	 */
1356 loop:
1357 	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
1358 		if (vp->v_bufobj.bo_dirty.bv_cnt == 0) {
1359 			VI_UNLOCK(vp);
1360 			continue;
1361 		}
1362 		if ((error = vget(vp, lockreq)) != 0) {
1363 			if (error == ENOENT) {
1364 				MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
1365 				goto loop;
1366 			}
1367 			continue;
1368 		}
1369 		error = VOP_FSYNC(vp, waitfor, td);
1370 		if (error)
1371 			allerror = error;
1372 		vput(vp);
1373 	}
1374 	return (allerror);
1375 }
1376 
1377 int
1378 vfs_stdnosync (mp, waitfor)
1379 	struct mount *mp;
1380 	int waitfor;
1381 {
1382 
1383 	return (0);
1384 }
1385 
1386 static int
1387 vop_stdcopy_file_range(struct vop_copy_file_range_args *ap)
1388 {
1389 	int error;
1390 
1391 	error = vn_generic_copy_file_range(ap->a_invp, ap->a_inoffp,
1392 	    ap->a_outvp, ap->a_outoffp, ap->a_lenp, ap->a_flags, ap->a_incred,
1393 	    ap->a_outcred, ap->a_fsizetd);
1394 	return (error);
1395 }
1396 
1397 int
1398 vfs_stdvget (mp, ino, flags, vpp)
1399 	struct mount *mp;
1400 	ino_t ino;
1401 	int flags;
1402 	struct vnode **vpp;
1403 {
1404 
1405 	return (EOPNOTSUPP);
1406 }
1407 
1408 int
1409 vfs_stdfhtovp (mp, fhp, flags, vpp)
1410 	struct mount *mp;
1411 	struct fid *fhp;
1412 	int flags;
1413 	struct vnode **vpp;
1414 {
1415 
1416 	return (EOPNOTSUPP);
1417 }
1418 
1419 int
1420 vfs_stdinit (vfsp)
1421 	struct vfsconf *vfsp;
1422 {
1423 
1424 	return (0);
1425 }
1426 
1427 int
1428 vfs_stduninit (vfsp)
1429 	struct vfsconf *vfsp;
1430 {
1431 
1432 	return(0);
1433 }
1434 
1435 int
1436 vfs_stdextattrctl(mp, cmd, filename_vp, attrnamespace, attrname)
1437 	struct mount *mp;
1438 	int cmd;
1439 	struct vnode *filename_vp;
1440 	int attrnamespace;
1441 	const char *attrname;
1442 {
1443 
1444 	if (filename_vp != NULL)
1445 		VOP_UNLOCK(filename_vp);
1446 	return (EOPNOTSUPP);
1447 }
1448 
1449 int
1450 vfs_stdsysctl(mp, op, req)
1451 	struct mount *mp;
1452 	fsctlop_t op;
1453 	struct sysctl_req *req;
1454 {
1455 
1456 	return (EOPNOTSUPP);
1457 }
1458 
1459 static vop_bypass_t *
1460 bp_by_off(struct vop_vector *vop, struct vop_generic_args *a)
1461 {
1462 
1463 	return (*(vop_bypass_t **)((char *)vop + a->a_desc->vdesc_vop_offset));
1464 }
1465 
1466 int
1467 vop_sigdefer(struct vop_vector *vop, struct vop_generic_args *a)
1468 {
1469 	vop_bypass_t *bp;
1470 	int prev_stops, rc;
1471 
1472 	bp = bp_by_off(vop, a);
1473 	MPASS(bp != NULL);
1474 
1475 	prev_stops = sigdeferstop(SIGDEFERSTOP_SILENT);
1476 	rc = bp(a);
1477 	sigallowstop(prev_stops);
1478 	return (rc);
1479 }
1480 
1481 static int
1482 vop_stdstat(struct vop_stat_args *a)
1483 {
1484 	struct vattr vattr;
1485 	struct vattr *vap;
1486 	struct vnode *vp;
1487 	struct stat *sb;
1488 	int error;
1489 	u_short mode;
1490 
1491 	vp = a->a_vp;
1492 	sb = a->a_sb;
1493 
1494 	error = vop_stat_helper_pre(a);
1495 	if (error != 0)
1496 		return (error);
1497 
1498 	vap = &vattr;
1499 
1500 	/*
1501 	 * Initialize defaults for new and unusual fields, so that file
1502 	 * systems which don't support these fields don't need to know
1503 	 * about them.
1504 	 */
1505 	vap->va_birthtime.tv_sec = -1;
1506 	vap->va_birthtime.tv_nsec = 0;
1507 	vap->va_fsid = VNOVAL;
1508 	vap->va_rdev = NODEV;
1509 
1510 	error = VOP_GETATTR(vp, vap, a->a_active_cred);
1511 	if (error)
1512 		goto out;
1513 
1514 	/*
1515 	 * Zero the spare stat fields
1516 	 */
1517 	bzero(sb, sizeof *sb);
1518 
1519 	/*
1520 	 * Copy from vattr table
1521 	 */
1522 	if (vap->va_fsid != VNOVAL)
1523 		sb->st_dev = vap->va_fsid;
1524 	else
1525 		sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0];
1526 	sb->st_ino = vap->va_fileid;
1527 	mode = vap->va_mode;
1528 	switch (vap->va_type) {
1529 	case VREG:
1530 		mode |= S_IFREG;
1531 		break;
1532 	case VDIR:
1533 		mode |= S_IFDIR;
1534 		break;
1535 	case VBLK:
1536 		mode |= S_IFBLK;
1537 		break;
1538 	case VCHR:
1539 		mode |= S_IFCHR;
1540 		break;
1541 	case VLNK:
1542 		mode |= S_IFLNK;
1543 		break;
1544 	case VSOCK:
1545 		mode |= S_IFSOCK;
1546 		break;
1547 	case VFIFO:
1548 		mode |= S_IFIFO;
1549 		break;
1550 	default:
1551 		error = EBADF;
1552 		goto out;
1553 	}
1554 	sb->st_mode = mode;
1555 	sb->st_nlink = vap->va_nlink;
1556 	sb->st_uid = vap->va_uid;
1557 	sb->st_gid = vap->va_gid;
1558 	sb->st_rdev = vap->va_rdev;
1559 	if (vap->va_size > OFF_MAX) {
1560 		error = EOVERFLOW;
1561 		goto out;
1562 	}
1563 	sb->st_size = vap->va_size;
1564 	sb->st_atim.tv_sec = vap->va_atime.tv_sec;
1565 	sb->st_atim.tv_nsec = vap->va_atime.tv_nsec;
1566 	sb->st_mtim.tv_sec = vap->va_mtime.tv_sec;
1567 	sb->st_mtim.tv_nsec = vap->va_mtime.tv_nsec;
1568 	sb->st_ctim.tv_sec = vap->va_ctime.tv_sec;
1569 	sb->st_ctim.tv_nsec = vap->va_ctime.tv_nsec;
1570 	sb->st_birthtim.tv_sec = vap->va_birthtime.tv_sec;
1571 	sb->st_birthtim.tv_nsec = vap->va_birthtime.tv_nsec;
1572 
1573 	/*
1574 	 * According to www.opengroup.org, the meaning of st_blksize is
1575 	 *   "a filesystem-specific preferred I/O block size for this
1576 	 *    object.  In some filesystem types, this may vary from file
1577 	 *    to file"
1578 	 * Use minimum/default of PAGE_SIZE (e.g. for VCHR).
1579 	 */
1580 
1581 	sb->st_blksize = max(PAGE_SIZE, vap->va_blocksize);
1582 	sb->st_flags = vap->va_flags;
1583 	sb->st_blocks = vap->va_bytes / S_BLKSIZE;
1584 	sb->st_gen = vap->va_gen;
1585 out:
1586 	return (vop_stat_helper_post(a, error));
1587 }
1588 
1589 static int
1590 vop_stdread_pgcache(struct vop_read_pgcache_args *ap __unused)
1591 {
1592 	return (EJUSTRETURN);
1593 }
1594