xref: /netbsd-src/sys/fs/tmpfs/tmpfs_vnops.c (revision 53b02e147d4ed531c0d2a5ca9b3e8026ba3e99b5)
1 /*	$NetBSD: tmpfs_vnops.c,v 1.148 2021/10/20 03:08:17 thorpej Exp $	*/
2 
3 /*
4  * Copyright (c) 2005, 2006, 2007, 2020 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
9  * 2005 program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * tmpfs vnode interface.
35  */
36 
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: tmpfs_vnops.c,v 1.148 2021/10/20 03:08:17 thorpej Exp $");
39 
40 #include <sys/param.h>
41 #include <sys/dirent.h>
42 #include <sys/fcntl.h>
43 #include <sys/event.h>
44 #include <sys/malloc.h>
45 #include <sys/namei.h>
46 #include <sys/stat.h>
47 #include <sys/uio.h>
48 #include <sys/unistd.h>
49 #include <sys/vnode.h>
50 #include <sys/lockf.h>
51 #include <sys/kauth.h>
52 #include <sys/atomic.h>
53 
54 #include <uvm/uvm_object.h>
55 
56 #include <miscfs/fifofs/fifo.h>
57 #include <miscfs/genfs/genfs.h>
58 #include <fs/tmpfs/tmpfs_vnops.h>
59 #include <fs/tmpfs/tmpfs.h>
60 
61 /*
62  * vnode operations vector used for files stored in a tmpfs file system.
63  */
64 int (**tmpfs_vnodeop_p)(void *);
65 const struct vnodeopv_entry_desc tmpfs_vnodeop_entries[] = {
66 	{ &vop_default_desc,		vn_default_error },
67 	{ &vop_parsepath_desc,		genfs_parsepath },
68 	{ &vop_lookup_desc,		tmpfs_lookup },
69 	{ &vop_create_desc,		tmpfs_create },
70 	{ &vop_mknod_desc,		tmpfs_mknod },
71 	{ &vop_open_desc,		tmpfs_open },
72 	{ &vop_close_desc,		tmpfs_close },
73 	{ &vop_access_desc,		tmpfs_access },
74 	{ &vop_accessx_desc,		genfs_accessx },
75 	{ &vop_getattr_desc,		tmpfs_getattr },
76 	{ &vop_setattr_desc,		tmpfs_setattr },
77 	{ &vop_read_desc,		tmpfs_read },
78 	{ &vop_write_desc,		tmpfs_write },
79 	{ &vop_fallocate_desc,		genfs_eopnotsupp },
80 	{ &vop_fdiscard_desc,		genfs_eopnotsupp },
81 	{ &vop_ioctl_desc,		genfs_enoioctl },
82 	{ &vop_fcntl_desc,		genfs_fcntl },
83 	{ &vop_poll_desc,		genfs_poll },
84 	{ &vop_kqfilter_desc,		genfs_kqfilter },
85 	{ &vop_revoke_desc,		genfs_revoke },
86 	{ &vop_mmap_desc,		genfs_mmap },
87 	{ &vop_fsync_desc,		tmpfs_fsync },
88 	{ &vop_seek_desc,		genfs_seek },
89 	{ &vop_remove_desc,		tmpfs_remove },
90 	{ &vop_link_desc,		tmpfs_link },
91 	{ &vop_rename_desc,		tmpfs_rename },
92 	{ &vop_mkdir_desc,		tmpfs_mkdir },
93 	{ &vop_rmdir_desc,		tmpfs_rmdir },
94 	{ &vop_symlink_desc,		tmpfs_symlink },
95 	{ &vop_readdir_desc,		tmpfs_readdir },
96 	{ &vop_readlink_desc,		tmpfs_readlink },
97 	{ &vop_abortop_desc,		genfs_abortop },
98 	{ &vop_inactive_desc,		tmpfs_inactive },
99 	{ &vop_reclaim_desc,		tmpfs_reclaim },
100 	{ &vop_lock_desc,		genfs_lock },
101 	{ &vop_unlock_desc,		genfs_unlock },
102 	{ &vop_bmap_desc,		genfs_eopnotsupp },
103 	{ &vop_strategy_desc,		genfs_eopnotsupp },
104 	{ &vop_print_desc,		tmpfs_print },
105 	{ &vop_pathconf_desc,		tmpfs_pathconf },
106 	{ &vop_islocked_desc,		genfs_islocked },
107 	{ &vop_advlock_desc,		tmpfs_advlock },
108 	{ &vop_bwrite_desc,		genfs_nullop },
109 	{ &vop_getpages_desc,		tmpfs_getpages },
110 	{ &vop_putpages_desc,		tmpfs_putpages },
111 	{ &vop_whiteout_desc,		tmpfs_whiteout },
112 	{ NULL, NULL }
113 };
114 
115 const struct vnodeopv_desc tmpfs_vnodeop_opv_desc = {
116 	&tmpfs_vnodeop_p, tmpfs_vnodeop_entries
117 };
118 
119 /*
120  * tmpfs_lookup: path name traversal routine.
121  *
122  * Arguments: dvp (directory being searched), vpp (result),
123  * cnp (component name - path).
124  *
125  * => Caller holds a reference and lock on dvp.
126  * => We return looked-up vnode (vpp) locked, with a reference held.
127  */
128 int
129 tmpfs_lookup(void *v)
130 {
131 	struct vop_lookup_v2_args /* {
132 		struct vnode *a_dvp;
133 		struct vnode **a_vpp;
134 		struct componentname *a_cnp;
135 	} */ *ap = v;
136 	vnode_t *dvp = ap->a_dvp, **vpp = ap->a_vpp;
137 	struct componentname *cnp = ap->a_cnp;
138 	const bool lastcn = (cnp->cn_flags & ISLASTCN) != 0;
139 	tmpfs_node_t *dnode, *tnode;
140 	tmpfs_dirent_t *de;
141 	int cachefound, iswhiteout;
142 	int error;
143 
144 	KASSERT(VOP_ISLOCKED(dvp));
145 
146 	dnode = VP_TO_TMPFS_DIR(dvp);
147 	*vpp = NULL;
148 
149 	/* Check accessibility of directory. */
150 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred);
151 	if (error) {
152 		goto out;
153 	}
154 
155 	/*
156 	 * If requesting the last path component on a read-only file system
157 	 * with a write operation, deny it.
158 	 */
159 	if (lastcn && (dvp->v_mount->mnt_flag & MNT_RDONLY) != 0 &&
160 	    (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
161 		error = EROFS;
162 		goto out;
163 	}
164 
165 	/*
166 	 * Avoid doing a linear scan of the directory if the requested
167 	 * directory/name couple is already in the cache.
168 	 */
169 	cachefound = cache_lookup(dvp, cnp->cn_nameptr, cnp->cn_namelen,
170 				  cnp->cn_nameiop, cnp->cn_flags,
171 				  &iswhiteout, vpp);
172 	if (iswhiteout) {
173 		cnp->cn_flags |= ISWHITEOUT;
174 	}
175 	if (cachefound && *vpp == NULLVP) {
176 		/* Negative cache hit. */
177 		error = ENOENT;
178 		goto out;
179 	} else if (cachefound) {
180 		error = 0;
181 		goto out;
182 	}
183 
184 	/*
185 	 * Treat an unlinked directory as empty (no "." or "..")
186 	 */
187 	if (dnode->tn_links == 0) {
188 		KASSERT(dnode->tn_size == 0);
189 		error = ENOENT;
190 		goto out;
191 	}
192 
193 	if (cnp->cn_flags & ISDOTDOT) {
194 		tmpfs_node_t *pnode;
195 
196 		/*
197 		 * Lookup of ".." case.
198 		 */
199 		if (lastcn && cnp->cn_nameiop == RENAME) {
200 			error = EINVAL;
201 			goto out;
202 		}
203 		KASSERT(dnode->tn_type == VDIR);
204 		pnode = dnode->tn_spec.tn_dir.tn_parent;
205 		if (pnode == NULL) {
206 			error = ENOENT;
207 			goto done;
208 		}
209 
210 		error = vcache_get(dvp->v_mount, &pnode, sizeof(pnode), vpp);
211 		goto done;
212 	} else if (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') {
213 		/*
214 		 * Lookup of "." case.
215 		 */
216 		if (lastcn && cnp->cn_nameiop == RENAME) {
217 			error = EISDIR;
218 			goto out;
219 		}
220 		vref(dvp);
221 		*vpp = dvp;
222 		error = 0;
223 		goto done;
224 	}
225 
226 	/*
227 	 * Other lookup cases: perform directory scan.
228 	 */
229 	de = tmpfs_dir_lookup(dnode, cnp);
230 	if (de == NULL || de->td_node == TMPFS_NODE_WHITEOUT) {
231 		/*
232 		 * The entry was not found in the directory.  This is valid
233 		 * if we are creating or renaming an entry and are working
234 		 * on the last component of the path name.
235 		 */
236 		if (lastcn && (cnp->cn_nameiop == CREATE ||
237 		    cnp->cn_nameiop == RENAME)) {
238 			error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred);
239 			if (error) {
240 				goto out;
241 			}
242 			error = EJUSTRETURN;
243 		} else {
244 			error = ENOENT;
245 		}
246 		if (de) {
247 			KASSERT(de->td_node == TMPFS_NODE_WHITEOUT);
248 			cnp->cn_flags |= ISWHITEOUT;
249 		}
250 		goto done;
251 	}
252 
253 	tnode = de->td_node;
254 
255 	/*
256 	 * If it is not the last path component and found a non-directory
257 	 * or non-link entry (which may itself be pointing to a directory),
258 	 * raise an error.
259 	 */
260 	if (!lastcn && tnode->tn_type != VDIR && tnode->tn_type != VLNK) {
261 		error = ENOTDIR;
262 		goto out;
263 	}
264 
265 	/* Check the permissions. */
266 	if (lastcn && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
267 		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred);
268 		if (error)
269 			goto out;
270 
271 		if ((dnode->tn_mode & S_ISTXT) != 0) {
272 			error = kauth_authorize_vnode(cnp->cn_cred,
273 			    KAUTH_VNODE_DELETE, tnode->tn_vnode,
274 			    dnode->tn_vnode, genfs_can_sticky(dvp, cnp->cn_cred,
275 			    dnode->tn_uid, tnode->tn_uid));
276 			if (error) {
277 				error = EPERM;
278 				goto out;
279 			}
280 		}
281 	}
282 
283 	/* Get a vnode for the matching entry. */
284 	error = vcache_get(dvp->v_mount, &tnode, sizeof(tnode), vpp);
285 done:
286 	/*
287 	 * Cache the result, unless request was for creation (as it does
288 	 * not improve the performance).
289 	 */
290 	if (cnp->cn_nameiop != CREATE) {
291 		cache_enter(dvp, *vpp, cnp->cn_nameptr, cnp->cn_namelen,
292 			    cnp->cn_flags);
293 	}
294 out:
295 	KASSERT(VOP_ISLOCKED(dvp));
296 
297 	return error;
298 }
299 
300 int
301 tmpfs_create(void *v)
302 {
303 	struct vop_create_v3_args /* {
304 		struct vnode		*a_dvp;
305 		struct vnode		**a_vpp;
306 		struct componentname	*a_cnp;
307 		struct vattr		*a_vap;
308 	} */ *ap = v;
309 	vnode_t *dvp = ap->a_dvp, **vpp = ap->a_vpp;
310 	struct componentname *cnp = ap->a_cnp;
311 	struct vattr *vap = ap->a_vap;
312 
313 	KASSERT(VOP_ISLOCKED(dvp));
314 	KASSERT(vap->va_type == VREG || vap->va_type == VSOCK);
315 	return tmpfs_construct_node(dvp, vpp, vap, cnp, NULL);
316 }
317 
318 int
319 tmpfs_mknod(void *v)
320 {
321 	struct vop_mknod_v3_args /* {
322 		struct vnode		*a_dvp;
323 		struct vnode		**a_vpp;
324 		struct componentname	*a_cnp;
325 		struct vattr		*a_vap;
326 	} */ *ap = v;
327 	vnode_t *dvp = ap->a_dvp, **vpp = ap->a_vpp;
328 	struct componentname *cnp = ap->a_cnp;
329 	struct vattr *vap = ap->a_vap;
330 	enum vtype vt = vap->va_type;
331 
332 	if (vt != VBLK && vt != VCHR && vt != VFIFO) {
333 		*vpp = NULL;
334 		return EINVAL;
335 	}
336 	return tmpfs_construct_node(dvp, vpp, vap, cnp, NULL);
337 }
338 
339 int
340 tmpfs_open(void *v)
341 {
342 	struct vop_open_args /* {
343 		struct vnode	*a_vp;
344 		int		a_mode;
345 		kauth_cred_t	a_cred;
346 	} */ *ap = v;
347 	vnode_t *vp = ap->a_vp;
348 	mode_t mode = ap->a_mode;
349 	tmpfs_node_t *node;
350 
351 	KASSERT(VOP_ISLOCKED(vp));
352 
353 	node = VP_TO_TMPFS_NODE(vp);
354 
355 	/* If the file is marked append-only, deny write requests. */
356 	if ((node->tn_flags & APPEND) != 0 &&
357 	    (mode & (FWRITE | O_APPEND)) == FWRITE) {
358 		return EPERM;
359 	}
360 	return 0;
361 }
362 
363 int
364 tmpfs_close(void *v)
365 {
366 	struct vop_close_args /* {
367 		struct vnode	*a_vp;
368 		int		a_fflag;
369 		kauth_cred_t	a_cred;
370 	} */ *ap = v;
371 	vnode_t *vp __diagused = ap->a_vp;
372 
373 	KASSERT(VOP_ISLOCKED(vp));
374 	return 0;
375 }
376 
377 int
378 tmpfs_access(void *v)
379 {
380 	struct vop_access_args /* {
381 		struct vnode	*a_vp;
382 		accmode_t	a_accmode;
383 		kauth_cred_t	a_cred;
384 	} */ *ap = v;
385 	vnode_t *vp = ap->a_vp;
386 	accmode_t accmode = ap->a_accmode;
387 	kauth_cred_t cred = ap->a_cred;
388 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
389 	const bool writing = (accmode & VWRITE) != 0;
390 
391 	KASSERT(VOP_ISLOCKED(vp));
392 
393 	/* Possible? */
394 	switch (vp->v_type) {
395 	case VDIR:
396 	case VLNK:
397 	case VREG:
398 		if (writing && (vp->v_mount->mnt_flag & MNT_RDONLY) != 0) {
399 			return EROFS;
400 		}
401 		break;
402 	case VBLK:
403 	case VCHR:
404 	case VSOCK:
405 	case VFIFO:
406 		break;
407 	default:
408 		return EINVAL;
409 	}
410 	if (writing && (node->tn_flags & IMMUTABLE) != 0) {
411 		return EPERM;
412 	}
413 
414 	return kauth_authorize_vnode(cred, KAUTH_ACCESS_ACTION(accmode,
415 	    vp->v_type, node->tn_mode), vp, NULL, genfs_can_access(vp, cred,
416 	    node->tn_uid, node->tn_gid, node->tn_mode, NULL, accmode));
417 }
418 
419 int
420 tmpfs_getattr(void *v)
421 {
422 	struct vop_getattr_args /* {
423 		struct vnode	*a_vp;
424 		struct vattr	*a_vap;
425 		kauth_cred_t	a_cred;
426 	} */ *ap = v;
427 	vnode_t *vp = ap->a_vp;
428 	struct vattr *vap = ap->a_vap;
429 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
430 
431 	vattr_null(vap);
432 
433 	vap->va_type = vp->v_type;
434 	vap->va_mode = node->tn_mode;
435 	vap->va_nlink = node->tn_links;
436 	vap->va_uid = node->tn_uid;
437 	vap->va_gid = node->tn_gid;
438 	vap->va_fsid = vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
439 	vap->va_fileid = node->tn_id;
440 	vap->va_size = node->tn_size;
441 	vap->va_blocksize = PAGE_SIZE;
442 	vap->va_gen = TMPFS_NODE_GEN(node);
443 	vap->va_flags = node->tn_flags;
444 	vap->va_rdev = (vp->v_type == VBLK || vp->v_type == VCHR) ?
445 	    node->tn_spec.tn_dev.tn_rdev : VNOVAL;
446 	vap->va_bytes = round_page(node->tn_size);
447 	vap->va_filerev = VNOVAL;
448 	vap->va_vaflags = 0;
449 	vap->va_spare = VNOVAL; /* XXX */
450 
451 	mutex_enter(&node->tn_timelock);
452 	tmpfs_update_locked(vp, 0);
453 	vap->va_atime = node->tn_atime;
454 	vap->va_mtime = node->tn_mtime;
455 	vap->va_ctime = node->tn_ctime;
456 	vap->va_birthtime = node->tn_birthtime;
457 	mutex_exit(&node->tn_timelock);
458 
459 	return 0;
460 }
461 
462 int
463 tmpfs_setattr(void *v)
464 {
465 	struct vop_setattr_args /* {
466 		struct vnode	*a_vp;
467 		struct vattr	*a_vap;
468 		kauth_cred_t	a_cred;
469 	} */ *ap = v;
470 	vnode_t *vp = ap->a_vp;
471 	struct vattr *vap = ap->a_vap;
472 	kauth_cred_t cred = ap->a_cred;
473 	lwp_t *l = curlwp;
474 	int error = 0;
475 
476 	KASSERT(VOP_ISLOCKED(vp));
477 
478 	/* Abort if any unsettable attribute is given. */
479 	if (vap->va_type != VNON || vap->va_nlink != VNOVAL ||
480 	    vap->va_fsid != VNOVAL || vap->va_fileid != VNOVAL ||
481 	    vap->va_blocksize != VNOVAL || vap->va_ctime.tv_sec != VNOVAL ||
482 	    vap->va_gen != VNOVAL || vap->va_rdev != VNOVAL ||
483 	    vap->va_bytes != VNOVAL) {
484 		return EINVAL;
485 	}
486 
487 	if (error == 0 && vap->va_flags != VNOVAL)
488 		error = tmpfs_chflags(vp, vap->va_flags, cred, l);
489 
490 	if (error == 0 && vap->va_size != VNOVAL)
491 		error = tmpfs_chsize(vp, vap->va_size, cred, l);
492 
493 	if (error == 0 && (vap->va_uid != VNOVAL || vap->va_gid != VNOVAL))
494 		error = tmpfs_chown(vp, vap->va_uid, vap->va_gid, cred, l);
495 
496 	if (error == 0 && vap->va_mode != VNOVAL)
497 		error = tmpfs_chmod(vp, vap->va_mode, cred, l);
498 
499 	const bool chsometime =
500 	    vap->va_atime.tv_sec != VNOVAL ||
501 	    vap->va_mtime.tv_sec != VNOVAL ||
502 	    vap->va_birthtime.tv_sec != VNOVAL;
503 	if (error == 0 && chsometime) {
504 		error = tmpfs_chtimes(vp, &vap->va_atime, &vap->va_mtime,
505 		    &vap->va_birthtime, vap->va_vaflags, cred, l);
506 	}
507 	return error;
508 }
509 
510 int
511 tmpfs_read(void *v)
512 {
513 	struct vop_read_args /* {
514 		struct vnode *a_vp;
515 		struct uio *a_uio;
516 		int a_ioflag;
517 		kauth_cred_t a_cred;
518 	} */ *ap = v;
519 	vnode_t *vp = ap->a_vp;
520 	struct uio *uio = ap->a_uio;
521 	const int ioflag = ap->a_ioflag;
522 	tmpfs_node_t *node;
523 	struct uvm_object *uobj;
524 	int error;
525 
526 	KASSERT(VOP_ISLOCKED(vp));
527 
528 	if (vp->v_type == VDIR) {
529 		return EISDIR;
530 	}
531 	if (uio->uio_offset < 0 || vp->v_type != VREG) {
532 		return EINVAL;
533 	}
534 
535 	/* Note: reading zero bytes should not update atime. */
536 	if (uio->uio_resid == 0) {
537 		return 0;
538 	}
539 
540 	node = VP_TO_TMPFS_NODE(vp);
541 	uobj = node->tn_spec.tn_reg.tn_aobj;
542 	error = 0;
543 
544 	while (error == 0 && uio->uio_resid > 0) {
545 		vsize_t len;
546 
547 		if (node->tn_size <= uio->uio_offset) {
548 			break;
549 		}
550 		len = MIN(node->tn_size - uio->uio_offset, uio->uio_resid);
551 		if (len == 0) {
552 			break;
553 		}
554 		error = ubc_uiomove(uobj, uio, len, IO_ADV_DECODE(ioflag),
555 		    UBC_READ | UBC_PARTIALOK | UBC_VNODE_FLAGS(vp));
556 	}
557 
558 	tmpfs_update(vp, TMPFS_UPDATE_ATIME);
559 	return error;
560 }
561 
562 int
563 tmpfs_write(void *v)
564 {
565 	struct vop_write_args /* {
566 		struct vnode	*a_vp;
567 		struct uio	*a_uio;
568 		int		a_ioflag;
569 		kauth_cred_t	a_cred;
570 	} */ *ap = v;
571 	vnode_t *vp = ap->a_vp;
572 	struct uio *uio = ap->a_uio;
573 	const int ioflag = ap->a_ioflag;
574 	tmpfs_node_t *node;
575 	struct uvm_object *uobj;
576 	off_t oldsize;
577 	int error, ubc_flags;
578 
579 	KASSERT(VOP_ISLOCKED(vp));
580 
581 	node = VP_TO_TMPFS_NODE(vp);
582 	oldsize = node->tn_size;
583 
584 	if ((vp->v_mount->mnt_flag & MNT_RDONLY) != 0) {
585 		error = EROFS;
586 		goto out;
587 	}
588 
589 	if (uio->uio_offset < 0 || vp->v_type != VREG) {
590 		error = EINVAL;
591 		goto out;
592 	}
593 	if (uio->uio_resid == 0) {
594 		error = 0;
595 		goto out;
596 	}
597 	if (ioflag & IO_APPEND) {
598 		uio->uio_offset = node->tn_size;
599 	}
600 
601 	if (uio->uio_offset + uio->uio_resid > node->tn_size) {
602 		error = tmpfs_reg_resize(vp, uio->uio_offset + uio->uio_resid);
603 		if (error)
604 			goto out;
605 	}
606 
607 	/*
608 	 * If we're extending the file and have data to write that would
609 	 * not leave an un-zeroed hole, we can avoid fault processing and
610 	 * zeroing of pages on allocation.
611 	 *
612 	 * Don't do this if the file is mapped and we need to touch an
613 	 * existing page, because writing a mapping of the file into itself
614 	 * could cause a deadlock on PG_BUSY.
615 	 *
616 	 * New pages will not become visible until finished here (because
617 	 * of PG_BUSY and the vnode lock).
618 	 */
619 	ubc_flags = UBC_WRITE | UBC_VNODE_FLAGS(vp);
620 #if 0
621 	/*
622 	 * XXX disable use of UBC_FAULTBUSY for now, this check is insufficient
623 	 * because it does not zero uninitialized parts of pages in all of
624 	 * the cases where zeroing is needed.
625 	 */
626 	if (uio->uio_offset >= oldsize &&
627 	    ((uio->uio_offset & (PAGE_SIZE - 1)) == 0 ||
628 	    ((vp->v_vflag & VV_MAPPED) == 0 &&
629 	    trunc_page(uio->uio_offset) == trunc_page(oldsize)))) {
630 		ubc_flags |= UBC_FAULTBUSY;
631 	}
632 #endif
633 
634 	uobj = node->tn_spec.tn_reg.tn_aobj;
635 	error = 0;
636 	while (error == 0 && uio->uio_resid > 0) {
637 		vsize_t len;
638 
639 		len = MIN(node->tn_size - uio->uio_offset, uio->uio_resid);
640 		if (len == 0) {
641 			break;
642 		}
643 		error = ubc_uiomove(uobj, uio, len, IO_ADV_DECODE(ioflag),
644 		    ubc_flags);
645 	}
646 	if (error) {
647 		(void)tmpfs_reg_resize(vp, oldsize);
648 	}
649 
650 	tmpfs_update(vp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
651 out:
652 	if (error) {
653 		KASSERT(oldsize == node->tn_size);
654 	} else {
655 		KASSERT(uio->uio_resid == 0);
656 	}
657 	return error;
658 }
659 
660 int
661 tmpfs_fsync(void *v)
662 {
663 	struct vop_fsync_args /* {
664 		struct vnode *a_vp;
665 		kauth_cred_t a_cred;
666 		int a_flags;
667 		off_t a_offlo;
668 		off_t a_offhi;
669 		struct lwp *a_l;
670 	} */ *ap = v;
671 	vnode_t *vp __diagused = ap->a_vp;
672 
673 	/* Nothing to do.  Should be up to date. */
674 	KASSERT(VOP_ISLOCKED(vp));
675 	return 0;
676 }
677 
678 /*
679  * tmpfs_remove: unlink a file.
680  *
681  * => Both directory (dvp) and file (vp) are locked.
682  * => We unlock and drop the reference on both.
683  */
684 int
685 tmpfs_remove(void *v)
686 {
687 	struct vop_remove_v3_args /* {
688 		struct vnode *a_dvp;
689 		struct vnode *a_vp;
690 		struct componentname *a_cnp;
691 		nlink_t ctx_vp_new_nlink;
692 	} */ *ap = v;
693 	vnode_t *dvp = ap->a_dvp, *vp = ap->a_vp;
694 	tmpfs_node_t *dnode, *node;
695 	tmpfs_dirent_t *de;
696 	int error, tflags;
697 
698 	KASSERT(VOP_ISLOCKED(dvp));
699 	KASSERT(VOP_ISLOCKED(vp));
700 
701 	if (vp->v_type == VDIR) {
702 		error = EPERM;
703 		goto out;
704 	}
705 	dnode = VP_TO_TMPFS_DIR(dvp);
706 	node = VP_TO_TMPFS_NODE(vp);
707 
708 	/*
709 	 * Files marked as immutable or append-only cannot be deleted.
710 	 * Likewise, files residing on directories marked as append-only
711 	 * cannot be deleted.
712 	 */
713 	if (node->tn_flags & (IMMUTABLE | APPEND)) {
714 		error = EPERM;
715 		goto out;
716 	}
717 	if (dnode->tn_flags & APPEND) {
718 		error = EPERM;
719 		goto out;
720 	}
721 
722 	/* Lookup the directory entry (check the cached hint first). */
723 	de = tmpfs_dir_cached(node);
724 	if (de == NULL) {
725 		struct componentname *cnp = ap->a_cnp;
726 		de = tmpfs_dir_lookup(dnode, cnp);
727 	}
728 	KASSERT(de && de->td_node == node);
729 
730 	/*
731 	 * Remove the entry from the directory (drops the link count) and
732 	 * destroy it or replace with a whiteout.
733 	 *
734 	 * Note: the inode referred by it will not be destroyed until the
735 	 * vnode is reclaimed/recycled.
736 	 */
737 
738 	tmpfs_dir_detach(dnode, de);
739 
740 	if (ap->a_cnp->cn_flags & DOWHITEOUT)
741 		tmpfs_dir_attach(dnode, de, TMPFS_NODE_WHITEOUT);
742 	else
743 		tmpfs_free_dirent(VFS_TO_TMPFS(vp->v_mount), de);
744 
745 	tflags = TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME;
746 	if (node->tn_links > 0) {
747 		/* We removed a hard link. */
748 		tflags |= TMPFS_UPDATE_CTIME;
749 	}
750 	ap->ctx_vp_new_nlink = node->tn_links;
751 	tmpfs_update(dvp, tflags);
752 	error = 0;
753 out:
754 	/* Drop the reference and unlock the node. */
755 	if (dvp == vp) {
756 		vrele(vp);
757 	} else {
758 		vput(vp);
759 	}
760 	return error;
761 }
762 
763 /*
764  * tmpfs_link: create a hard link.
765  */
766 int
767 tmpfs_link(void *v)
768 {
769 	struct vop_link_v2_args /* {
770 		struct vnode *a_dvp;
771 		struct vnode *a_vp;
772 		struct componentname *a_cnp;
773 	} */ *ap = v;
774 	vnode_t *dvp = ap->a_dvp;
775 	vnode_t *vp = ap->a_vp;
776 	struct componentname *cnp = ap->a_cnp;
777 	tmpfs_node_t *dnode, *node;
778 	tmpfs_dirent_t *de;
779 	int error;
780 
781 	KASSERT(dvp != vp);
782 	KASSERT(VOP_ISLOCKED(dvp));
783 	KASSERT(vp->v_type != VDIR);
784 	KASSERT(dvp->v_mount == vp->v_mount);
785 
786 	dnode = VP_TO_TMPFS_DIR(dvp);
787 	node = VP_TO_TMPFS_NODE(vp);
788 
789 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
790 
791 	/* Check for maximum number of links limit. */
792 	if (node->tn_links == LINK_MAX) {
793 		error = EMLINK;
794 		goto out;
795 	}
796 	KASSERT(node->tn_links < LINK_MAX);
797 
798 	/* We cannot create links of files marked immutable or append-only. */
799 	if (node->tn_flags & (IMMUTABLE | APPEND)) {
800 		error = EPERM;
801 		goto out;
802 	}
803 
804 	/* Allocate a new directory entry to represent the inode. */
805 	error = tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount),
806 	    cnp->cn_nameptr, cnp->cn_namelen, &de);
807 	if (error) {
808 		goto out;
809 	}
810 
811 	/*
812 	 * Insert the entry into the directory.
813 	 * It will increase the inode link count.
814 	 */
815 	tmpfs_dir_attach(dnode, de, node);
816 	tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
817 
818 	/* Update the timestamps. */
819 	tmpfs_update(vp, TMPFS_UPDATE_CTIME);
820 	error = 0;
821 out:
822 	VOP_UNLOCK(vp);
823 	return error;
824 }
825 
826 int
827 tmpfs_mkdir(void *v)
828 {
829 	struct vop_mkdir_v3_args /* {
830 		struct vnode		*a_dvp;
831 		struct vnode		**a_vpp;
832 		struct componentname	*a_cnp;
833 		struct vattr		*a_vap;
834 	} */ *ap = v;
835 	vnode_t *dvp = ap->a_dvp;
836 	vnode_t **vpp = ap->a_vpp;
837 	struct componentname *cnp = ap->a_cnp;
838 	struct vattr *vap = ap->a_vap;
839 
840 	KASSERT(vap->va_type == VDIR);
841 	return tmpfs_construct_node(dvp, vpp, vap, cnp, NULL);
842 }
843 
844 int
845 tmpfs_rmdir(void *v)
846 {
847 	struct vop_rmdir_v2_args /* {
848 		struct vnode		*a_dvp;
849 		struct vnode		*a_vp;
850 		struct componentname	*a_cnp;
851 	} */ *ap = v;
852 	vnode_t *dvp = ap->a_dvp;
853 	vnode_t *vp = ap->a_vp;
854 	tmpfs_mount_t *tmp = VFS_TO_TMPFS(dvp->v_mount);
855 	tmpfs_node_t *dnode = VP_TO_TMPFS_DIR(dvp);
856 	tmpfs_node_t *node = VP_TO_TMPFS_DIR(vp);
857 	tmpfs_dirent_t *de;
858 	int error = 0;
859 
860 	KASSERT(VOP_ISLOCKED(dvp));
861 	KASSERT(VOP_ISLOCKED(vp));
862 
863 	/*
864 	 * Directories with more than two entries ('.' and '..') cannot be
865 	 * removed.  There may be whiteout entries, which we will destroy.
866 	 */
867 	if (node->tn_size > 0) {
868 		/*
869 		 * If never had whiteout entries, the directory is certainly
870 		 * not empty.  Otherwise, scan for any non-whiteout entry.
871 		 */
872 		if ((node->tn_gen & TMPFS_WHITEOUT_BIT) == 0) {
873 			error = ENOTEMPTY;
874 			goto out;
875 		}
876 		TAILQ_FOREACH(de, &node->tn_spec.tn_dir.tn_dir, td_entries) {
877 			if (de->td_node != TMPFS_NODE_WHITEOUT) {
878 				error = ENOTEMPTY;
879 				goto out;
880 			}
881 		}
882 		KASSERT(error == 0);
883 	}
884 
885 	KASSERT(node->tn_spec.tn_dir.tn_parent == dnode);
886 
887 	/* Lookup the directory entry (check the cached hint first). */
888 	de = tmpfs_dir_cached(node);
889 	if (de == NULL) {
890 		struct componentname *cnp = ap->a_cnp;
891 		de = tmpfs_dir_lookup(dnode, cnp);
892 	}
893 	KASSERT(de && de->td_node == node);
894 
895 	/* Check flags to see if we are allowed to remove the directory. */
896 	if (dnode->tn_flags & APPEND || node->tn_flags & (IMMUTABLE | APPEND)) {
897 		error = EPERM;
898 		goto out;
899 	}
900 
901 	/* Decrement the link count for the virtual '.' entry. */
902 	node->tn_links--;
903 
904 	/* Detach the directory entry from the directory. */
905 	tmpfs_dir_detach(dnode, de);
906 
907 	/* Purge the cache for parent. */
908 	cache_purge(dvp);
909 
910 	/*
911 	 * Destroy the directory entry or replace it with a whiteout.
912 	 *
913 	 * Note: the inode referred by it will not be destroyed until the
914 	 * vnode is reclaimed.
915 	 */
916 	if (ap->a_cnp->cn_flags & DOWHITEOUT)
917 		tmpfs_dir_attach(dnode, de, TMPFS_NODE_WHITEOUT);
918 	else
919 		tmpfs_free_dirent(tmp, de);
920 
921 	/* Destroy the whiteout entries from the node. */
922 	while ((de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir)) != NULL) {
923 		KASSERT(de->td_node == TMPFS_NODE_WHITEOUT);
924 		tmpfs_dir_detach(node, de);
925 		tmpfs_free_dirent(tmp, de);
926 	}
927 	tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
928 
929 	KASSERT(node->tn_size == 0);
930 	KASSERT(node->tn_links == 0);
931 out:
932 	/* Release the node. */
933 	KASSERT(dvp != vp);
934 	vput(vp);
935 	return error;
936 }
937 
938 int
939 tmpfs_symlink(void *v)
940 {
941 	struct vop_symlink_v3_args /* {
942 		struct vnode		*a_dvp;
943 		struct vnode		**a_vpp;
944 		struct componentname	*a_cnp;
945 		struct vattr		*a_vap;
946 		char			*a_target;
947 	} */ *ap = v;
948 	vnode_t *dvp = ap->a_dvp;
949 	vnode_t **vpp = ap->a_vpp;
950 	struct componentname *cnp = ap->a_cnp;
951 	struct vattr *vap = ap->a_vap;
952 	char *target = ap->a_target;
953 
954 	KASSERT(vap->va_type == VLNK);
955 	return tmpfs_construct_node(dvp, vpp, vap, cnp, target);
956 }
957 
958 int
959 tmpfs_readdir(void *v)
960 {
961 	struct vop_readdir_args /* {
962 		struct vnode	*a_vp;
963 		struct uio	*a_uio;
964 		kauth_cred_t	a_cred;
965 		int		*a_eofflag;
966 		off_t		**a_cookies;
967 		int		*ncookies;
968 	} */ *ap = v;
969 	vnode_t *vp = ap->a_vp;
970 	struct uio *uio = ap->a_uio;
971 	int *eofflag = ap->a_eofflag;
972 	off_t **cookies = ap->a_cookies;
973 	int *ncookies = ap->a_ncookies;
974 	off_t startoff, cnt;
975 	tmpfs_node_t *node;
976 	int error;
977 
978 	KASSERT(VOP_ISLOCKED(vp));
979 
980 	/* This operation only makes sense on directory nodes. */
981 	if (vp->v_type != VDIR) {
982 		return ENOTDIR;
983 	}
984 	node = VP_TO_TMPFS_DIR(vp);
985 	startoff = uio->uio_offset;
986 	cnt = 0;
987 
988 	/*
989 	 * Retrieve the directory entries, unless it is being destroyed.
990 	 */
991 	if (node->tn_links) {
992 		error = tmpfs_dir_getdents(node, uio, &cnt);
993 	} else {
994 		error = 0;
995 	}
996 
997 	if (eofflag != NULL) {
998 		*eofflag = !error && uio->uio_offset == TMPFS_DIRSEQ_EOF;
999 	}
1000 	if (error || cookies == NULL || ncookies == NULL) {
1001 		return error;
1002 	}
1003 
1004 	/* Update NFS-related variables, if any. */
1005 	tmpfs_dirent_t *de = NULL;
1006 	off_t i, off = startoff;
1007 
1008 	*cookies = malloc(cnt * sizeof(off_t), M_TEMP, M_WAITOK);
1009 	*ncookies = cnt;
1010 
1011 	for (i = 0; i < cnt; i++) {
1012 		KASSERT(off != TMPFS_DIRSEQ_EOF);
1013 		if (off != TMPFS_DIRSEQ_DOT) {
1014 			if (off == TMPFS_DIRSEQ_DOTDOT) {
1015 				de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir);
1016 			} else if (de != NULL) {
1017 				de = TAILQ_NEXT(de, td_entries);
1018 			} else {
1019 				de = tmpfs_dir_lookupbyseq(node, off);
1020 				KASSERT(de != NULL);
1021 				de = TAILQ_NEXT(de, td_entries);
1022 			}
1023 			if (de == NULL) {
1024 				off = TMPFS_DIRSEQ_EOF;
1025 			} else {
1026 				off = tmpfs_dir_getseq(node, de);
1027 			}
1028 		} else {
1029 			off = TMPFS_DIRSEQ_DOTDOT;
1030 		}
1031 		(*cookies)[i] = off;
1032 	}
1033 	KASSERT(uio->uio_offset == off);
1034 	return error;
1035 }
1036 
1037 int
1038 tmpfs_readlink(void *v)
1039 {
1040 	struct vop_readlink_args /* {
1041 		struct vnode	*a_vp;
1042 		struct uio	*a_uio;
1043 		kauth_cred_t	a_cred;
1044 	} */ *ap = v;
1045 	vnode_t *vp = ap->a_vp;
1046 	struct uio *uio = ap->a_uio;
1047 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1048 	int error;
1049 
1050 	KASSERT(VOP_ISLOCKED(vp));
1051 	KASSERT(uio->uio_offset == 0);
1052 	KASSERT(vp->v_type == VLNK);
1053 
1054 	/* Note: readlink(2) returns the path without NUL terminator. */
1055 	if (node->tn_size > 0) {
1056 		error = uiomove(node->tn_spec.tn_lnk.tn_link,
1057 		    MIN(node->tn_size, uio->uio_resid), uio);
1058 	} else {
1059 		error = 0;
1060 	}
1061 	tmpfs_update(vp, TMPFS_UPDATE_ATIME);
1062 
1063 	return error;
1064 }
1065 
1066 int
1067 tmpfs_inactive(void *v)
1068 {
1069 	struct vop_inactive_v2_args /* {
1070 		struct vnode *a_vp;
1071 		bool *a_recycle;
1072 	} */ *ap = v;
1073 	vnode_t *vp = ap->a_vp;
1074 	tmpfs_node_t *node;
1075 	int error = 0;
1076 
1077 	KASSERT(VOP_ISLOCKED(vp));
1078 
1079 	node = VP_TO_TMPFS_NODE(vp);
1080 	if (node->tn_links == 0) {
1081 		/*
1082 		 * Mark node as dead by setting its generation to zero.
1083 		 */
1084 		atomic_and_32(&node->tn_gen, ~TMPFS_NODE_GEN_MASK);
1085 
1086 		/*
1087 		 * If the file has been deleted, truncate it, otherwise VFS
1088 		 * will quite rightly try to write back dirty data, which in
1089 		 * the case of tmpfs/UAO means needless page deactivations.
1090 		 */
1091 		if (vp->v_type == VREG) {
1092 			error = tmpfs_reg_resize(vp, 0);
1093 		}
1094 		*ap->a_recycle = true;
1095 	} else {
1096 		tmpfs_update(vp, 0);
1097 		*ap->a_recycle = false;
1098 	}
1099 
1100 	return error;
1101 }
1102 
1103 int
1104 tmpfs_reclaim(void *v)
1105 {
1106 	struct vop_reclaim_v2_args /* {
1107 		struct vnode *a_vp;
1108 	} */ *ap = v;
1109 	vnode_t *vp = ap->a_vp;
1110 	tmpfs_mount_t *tmp = VFS_TO_TMPFS(vp->v_mount);
1111 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1112 
1113 	/* Unlock vnode.  We still have exclusive access to it. */
1114 	VOP_UNLOCK(vp);
1115 
1116 	/* Disassociate inode from vnode. */
1117 	node->tn_vnode = NULL;
1118 	vp->v_data = NULL;
1119 
1120 	/* If inode is not referenced, i.e. no links, then destroy it. */
1121 	if (node->tn_links == 0)
1122 		tmpfs_free_node(tmp, node);
1123 	return 0;
1124 }
1125 
1126 int
1127 tmpfs_pathconf(void *v)
1128 {
1129 	struct vop_pathconf_args /* {
1130 		struct vnode	*a_vp;
1131 		int		a_name;
1132 		register_t	*a_retval;
1133 	} */ *ap = v;
1134 	register_t *retval = ap->a_retval;
1135 
1136 	switch (ap->a_name) {
1137 	case _PC_LINK_MAX:
1138 		*retval = LINK_MAX;
1139 		return 0;
1140 	case _PC_NAME_MAX:
1141 		*retval = TMPFS_MAXNAMLEN;
1142 		return 0;
1143 	case _PC_PATH_MAX:
1144 		*retval = PATH_MAX;
1145 		return 0;
1146 	case _PC_PIPE_BUF:
1147 		*retval = PIPE_BUF;
1148 		return 0;
1149 	case _PC_CHOWN_RESTRICTED:
1150 		*retval = 1;
1151 		return 0;
1152 	case _PC_NO_TRUNC:
1153 		*retval = 1;
1154 		return 0;
1155 	case _PC_SYNC_IO:
1156 		*retval = 1;
1157 		return 0;
1158 	case _PC_FILESIZEBITS:
1159 		*retval = sizeof(off_t) * CHAR_BIT;
1160 		return 0;
1161 	default:
1162 		return genfs_pathconf(ap);
1163 	}
1164 }
1165 
1166 int
1167 tmpfs_advlock(void *v)
1168 {
1169 	struct vop_advlock_args /* {
1170 		struct vnode	*a_vp;
1171 		void *		a_id;
1172 		int		a_op;
1173 		struct flock	*a_fl;
1174 		int		a_flags;
1175 	} */ *ap = v;
1176 	vnode_t *vp = ap->a_vp;
1177 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1178 
1179 	return lf_advlock(v, &node->tn_lockf, node->tn_size);
1180 }
1181 
1182 int
1183 tmpfs_getpages(void *v)
1184 {
1185 	struct vop_getpages_args /* {
1186 		struct vnode *a_vp;
1187 		voff_t a_offset;
1188 		struct vm_page **a_m;
1189 		int *a_count;
1190 		int a_centeridx;
1191 		vm_prot_t a_access_type;
1192 		int a_advice;
1193 		int a_flags;
1194 	} */ * const ap = v;
1195 	vnode_t *vp = ap->a_vp;
1196 	const voff_t offset = ap->a_offset;
1197 	struct vm_page **pgs = ap->a_m;
1198 	const int centeridx = ap->a_centeridx;
1199 	const vm_prot_t access_type = ap->a_access_type;
1200 	const int advice = ap->a_advice;
1201 	const int flags = ap->a_flags;
1202 	int error, iflag, npages = *ap->a_count;
1203 	tmpfs_node_t *node;
1204 	struct uvm_object *uobj;
1205 
1206 	KASSERT(vp->v_type == VREG);
1207 	KASSERT(rw_lock_held(vp->v_uobj.vmobjlock));
1208 
1209 	/*
1210 	 * Currently, PGO_PASTEOF is not supported.
1211 	 */
1212 	if (vp->v_size <= offset + (centeridx << PAGE_SHIFT)) {
1213 		if ((flags & PGO_LOCKED) == 0)
1214 			rw_exit(vp->v_uobj.vmobjlock);
1215 		return EINVAL;
1216 	}
1217 
1218 	if (vp->v_size < offset + (npages << PAGE_SHIFT)) {
1219 		npages = (round_page(vp->v_size) - offset) >> PAGE_SHIFT;
1220 	}
1221 
1222 	/*
1223 	 * Check for reclaimed vnode.  v_interlock is not held here, but
1224 	 * VI_DEADCHECK is set with vmobjlock held.
1225 	 */
1226 	iflag = atomic_load_relaxed(&vp->v_iflag);
1227 	if (__predict_false((iflag & VI_DEADCHECK) != 0)) {
1228 		mutex_enter(vp->v_interlock);
1229 		error = vdead_check(vp, VDEAD_NOWAIT);
1230 		mutex_exit(vp->v_interlock);
1231 		if (error) {
1232 			if ((flags & PGO_LOCKED) == 0)
1233 				rw_exit(vp->v_uobj.vmobjlock);
1234 			return error;
1235 		}
1236 	}
1237 
1238 	node = VP_TO_TMPFS_NODE(vp);
1239 	uobj = node->tn_spec.tn_reg.tn_aobj;
1240 
1241 	/*
1242 	 * Update timestamp lazily.  The update will be made real when
1243 	 * a synchronous update is next made -- or by tmpfs_getattr,
1244 	 * tmpfs_putpages, and tmpfs_inactive.
1245 	 */
1246 	if ((flags & PGO_NOTIMESTAMP) == 0) {
1247 		u_int tflags = 0;
1248 
1249 		if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
1250 			tflags |= TMPFS_UPDATE_ATIME;
1251 
1252 		if ((access_type & VM_PROT_WRITE) != 0) {
1253 			tflags |= TMPFS_UPDATE_MTIME;
1254 			if (vp->v_mount->mnt_flag & MNT_RELATIME)
1255 				tflags |= TMPFS_UPDATE_ATIME;
1256 		}
1257 		tmpfs_update_lazily(vp, tflags);
1258 	}
1259 
1260 	/* Invoke the pager.  The vnode vmobjlock is shared with the UAO. */
1261 	KASSERT(vp->v_uobj.vmobjlock == uobj->vmobjlock);
1262 	error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, centeridx,
1263 	    access_type, advice, flags);
1264 #if defined(DEBUG)
1265 	if (!error && pgs) {
1266 		KASSERT(pgs[centeridx] != NULL);
1267 	}
1268 #endif
1269 	return error;
1270 }
1271 
1272 int
1273 tmpfs_putpages(void *v)
1274 {
1275 	struct vop_putpages_args /* {
1276 		struct vnode *a_vp;
1277 		voff_t a_offlo;
1278 		voff_t a_offhi;
1279 		int a_flags;
1280 	} */ * const ap = v;
1281 	vnode_t *vp = ap->a_vp;
1282 	const voff_t offlo = ap->a_offlo;
1283 	const voff_t offhi = ap->a_offhi;
1284 	const int flags = ap->a_flags;
1285 	tmpfs_node_t *node;
1286 	struct uvm_object *uobj;
1287 	int error;
1288 
1289 	KASSERT(rw_write_held(vp->v_uobj.vmobjlock));
1290 
1291 	if (vp->v_type != VREG) {
1292 		rw_exit(vp->v_uobj.vmobjlock);
1293 		return 0;
1294 	}
1295 
1296 	node = VP_TO_TMPFS_NODE(vp);
1297 	uobj = node->tn_spec.tn_reg.tn_aobj;
1298 
1299 	KASSERT(vp->v_uobj.vmobjlock == uobj->vmobjlock);
1300 	error = (*uobj->pgops->pgo_put)(uobj, offlo, offhi, flags);
1301 
1302 	/* XXX mtime */
1303 
1304 	/* Process deferred updates. */
1305 	tmpfs_update(vp, 0);
1306 	return error;
1307 }
1308 
1309 int
1310 tmpfs_whiteout(void *v)
1311 {
1312 	struct vop_whiteout_args /* {
1313 		struct vnode		*a_dvp;
1314 		struct componentname	*a_cnp;
1315 		int			a_flags;
1316 	} */ *ap = v;
1317 	vnode_t *dvp = ap->a_dvp;
1318 	struct componentname *cnp = ap->a_cnp;
1319 	const int flags = ap->a_flags;
1320 	tmpfs_mount_t *tmp = VFS_TO_TMPFS(dvp->v_mount);
1321 	tmpfs_node_t *dnode = VP_TO_TMPFS_DIR(dvp);
1322 	tmpfs_dirent_t *de;
1323 	int error;
1324 
1325 	switch (flags) {
1326 	case LOOKUP:
1327 		break;
1328 	case CREATE:
1329 		error = tmpfs_alloc_dirent(tmp, cnp->cn_nameptr,
1330 		    cnp->cn_namelen, &de);
1331 		if (error)
1332 			return error;
1333 		tmpfs_dir_attach(dnode, de, TMPFS_NODE_WHITEOUT);
1334 		break;
1335 	case DELETE:
1336 		cnp->cn_flags &= ~DOWHITEOUT; /* when in doubt, cargo cult */
1337 		de = tmpfs_dir_lookup(dnode, cnp);
1338 		if (de == NULL)
1339 			return ENOENT;
1340 		tmpfs_dir_detach(dnode, de);
1341 		tmpfs_free_dirent(tmp, de);
1342 		break;
1343 	}
1344 	tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
1345 	return 0;
1346 }
1347 
1348 int
1349 tmpfs_print(void *v)
1350 {
1351 	struct vop_print_args /* {
1352 		struct vnode	*a_vp;
1353 	} */ *ap = v;
1354 	vnode_t *vp = ap->a_vp;
1355 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1356 
1357 	printf("tag VT_TMPFS, tmpfs_node %p, flags 0x%x, links %d\n"
1358 	    "\tmode 0%o, owner %d, group %d, size %" PRIdMAX,
1359 	    node, node->tn_flags, node->tn_links, node->tn_mode, node->tn_uid,
1360 	    node->tn_gid, (uintmax_t)node->tn_size);
1361 	if (vp->v_type == VFIFO) {
1362 		VOCALL(fifo_vnodeop_p, VOFFSET(vop_print), v);
1363 	}
1364 	printf("\n");
1365 	return 0;
1366 }
1367