xref: /netbsd-src/sys/fs/tmpfs/tmpfs_vnops.c (revision 0e552da7216834a96e91ad098e59272b41087480)
1 /*	$NetBSD: tmpfs_vnops.c,v 1.141 2020/05/19 22:22:15 ad 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 1.141 2020/05/19 22:22:15 ad 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.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_lookup_desc,		tmpfs_lookup },
68 	{ &vop_create_desc,		tmpfs_create },
69 	{ &vop_mknod_desc,		tmpfs_mknod },
70 	{ &vop_open_desc,		tmpfs_open },
71 	{ &vop_close_desc,		tmpfs_close },
72 	{ &vop_access_desc,		tmpfs_access },
73 	{ &vop_accessx_desc,		genfs_accessx },
74 	{ &vop_getattr_desc,		tmpfs_getattr },
75 	{ &vop_setattr_desc,		tmpfs_setattr },
76 	{ &vop_read_desc,		tmpfs_read },
77 	{ &vop_write_desc,		tmpfs_write },
78 	{ &vop_fallocate_desc,		genfs_eopnotsupp },
79 	{ &vop_fdiscard_desc,		genfs_eopnotsupp },
80 	{ &vop_ioctl_desc,		tmpfs_ioctl },
81 	{ &vop_fcntl_desc,		tmpfs_fcntl },
82 	{ &vop_poll_desc,		tmpfs_poll },
83 	{ &vop_kqfilter_desc,		tmpfs_kqfilter },
84 	{ &vop_revoke_desc,		tmpfs_revoke },
85 	{ &vop_mmap_desc,		tmpfs_mmap },
86 	{ &vop_fsync_desc,		tmpfs_fsync },
87 	{ &vop_seek_desc,		tmpfs_seek },
88 	{ &vop_remove_desc,		tmpfs_remove },
89 	{ &vop_link_desc,		tmpfs_link },
90 	{ &vop_rename_desc,		tmpfs_rename },
91 	{ &vop_mkdir_desc,		tmpfs_mkdir },
92 	{ &vop_rmdir_desc,		tmpfs_rmdir },
93 	{ &vop_symlink_desc,		tmpfs_symlink },
94 	{ &vop_readdir_desc,		tmpfs_readdir },
95 	{ &vop_readlink_desc,		tmpfs_readlink },
96 	{ &vop_abortop_desc,		tmpfs_abortop },
97 	{ &vop_inactive_desc,		tmpfs_inactive },
98 	{ &vop_reclaim_desc,		tmpfs_reclaim },
99 	{ &vop_lock_desc,		tmpfs_lock },
100 	{ &vop_unlock_desc,		tmpfs_unlock },
101 	{ &vop_bmap_desc,		tmpfs_bmap },
102 	{ &vop_strategy_desc,		tmpfs_strategy },
103 	{ &vop_print_desc,		tmpfs_print },
104 	{ &vop_pathconf_desc,		tmpfs_pathconf },
105 	{ &vop_islocked_desc,		tmpfs_islocked },
106 	{ &vop_advlock_desc,		tmpfs_advlock },
107 	{ &vop_bwrite_desc,		tmpfs_bwrite },
108 	{ &vop_getpages_desc,		tmpfs_getpages },
109 	{ &vop_putpages_desc,		tmpfs_putpages },
110 	{ &vop_whiteout_desc,		tmpfs_whiteout },
111 	{ NULL, NULL }
112 };
113 
114 const struct vnodeopv_desc tmpfs_vnodeop_opv_desc = {
115 	&tmpfs_vnodeop_p, tmpfs_vnodeop_entries
116 };
117 
118 /*
119  * tmpfs_lookup: path name traversal routine.
120  *
121  * Arguments: dvp (directory being searched), vpp (result),
122  * cnp (component name - path).
123  *
124  * => Caller holds a reference and lock on dvp.
125  * => We return looked-up vnode (vpp) locked, with a reference held.
126  */
127 int
128 tmpfs_lookup(void *v)
129 {
130 	struct vop_lookup_v2_args /* {
131 		struct vnode *a_dvp;
132 		struct vnode **a_vpp;
133 		struct componentname *a_cnp;
134 	} */ *ap = v;
135 	vnode_t *dvp = ap->a_dvp, **vpp = ap->a_vpp;
136 	struct componentname *cnp = ap->a_cnp;
137 	const bool lastcn = (cnp->cn_flags & ISLASTCN) != 0;
138 	tmpfs_node_t *dnode, *tnode;
139 	tmpfs_dirent_t *de;
140 	int cachefound, iswhiteout;
141 	int error;
142 
143 	KASSERT(VOP_ISLOCKED(dvp));
144 
145 	dnode = VP_TO_TMPFS_DIR(dvp);
146 	*vpp = NULL;
147 
148 	/* Check accessibility of directory. */
149 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred);
150 	if (error) {
151 		goto out;
152 	}
153 
154 	/*
155 	 * If requesting the last path component on a read-only file system
156 	 * with a write operation, deny it.
157 	 */
158 	if (lastcn && (dvp->v_mount->mnt_flag & MNT_RDONLY) != 0 &&
159 	    (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
160 		error = EROFS;
161 		goto out;
162 	}
163 
164 	/*
165 	 * Avoid doing a linear scan of the directory if the requested
166 	 * directory/name couple is already in the cache.
167 	 */
168 	cachefound = cache_lookup(dvp, cnp->cn_nameptr, cnp->cn_namelen,
169 				  cnp->cn_nameiop, cnp->cn_flags,
170 				  &iswhiteout, vpp);
171 	if (iswhiteout) {
172 		cnp->cn_flags |= ISWHITEOUT;
173 	}
174 	if (cachefound && *vpp == NULLVP) {
175 		/* Negative cache hit. */
176 		error = ENOENT;
177 		goto out;
178 	} else if (cachefound) {
179 		error = 0;
180 		goto out;
181 	}
182 
183 	/*
184 	 * Treat an unlinked directory as empty (no "." or "..")
185 	 */
186 	if (dnode->tn_links == 0) {
187 		KASSERT(dnode->tn_size == 0);
188 		error = ENOENT;
189 		goto out;
190 	}
191 
192 	if (cnp->cn_flags & ISDOTDOT) {
193 		tmpfs_node_t *pnode;
194 
195 		/*
196 		 * Lookup of ".." case.
197 		 */
198 		if (lastcn && cnp->cn_nameiop == RENAME) {
199 			error = EINVAL;
200 			goto out;
201 		}
202 		KASSERT(dnode->tn_type == VDIR);
203 		pnode = dnode->tn_spec.tn_dir.tn_parent;
204 		if (pnode == NULL) {
205 			error = ENOENT;
206 			goto done;
207 		}
208 
209 		error = vcache_get(dvp->v_mount, &pnode, sizeof(pnode), vpp);
210 		goto done;
211 	} else if (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') {
212 		/*
213 		 * Lookup of "." case.
214 		 */
215 		if (lastcn && cnp->cn_nameiop == RENAME) {
216 			error = EISDIR;
217 			goto out;
218 		}
219 		vref(dvp);
220 		*vpp = dvp;
221 		error = 0;
222 		goto done;
223 	}
224 
225 	/*
226 	 * Other lookup cases: perform directory scan.
227 	 */
228 	de = tmpfs_dir_lookup(dnode, cnp);
229 	if (de == NULL || de->td_node == TMPFS_NODE_WHITEOUT) {
230 		/*
231 		 * The entry was not found in the directory.  This is valid
232 		 * if we are creating or renaming an entry and are working
233 		 * on the last component of the path name.
234 		 */
235 		if (lastcn && (cnp->cn_nameiop == CREATE ||
236 		    cnp->cn_nameiop == RENAME)) {
237 			error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred);
238 			if (error) {
239 				goto out;
240 			}
241 			error = EJUSTRETURN;
242 		} else {
243 			error = ENOENT;
244 		}
245 		if (de) {
246 			KASSERT(de->td_node == TMPFS_NODE_WHITEOUT);
247 			cnp->cn_flags |= ISWHITEOUT;
248 		}
249 		goto done;
250 	}
251 
252 	tnode = de->td_node;
253 
254 	/*
255 	 * If it is not the last path component and found a non-directory
256 	 * or non-link entry (which may itself be pointing to a directory),
257 	 * raise an error.
258 	 */
259 	if (!lastcn && tnode->tn_type != VDIR && tnode->tn_type != VLNK) {
260 		error = ENOTDIR;
261 		goto out;
262 	}
263 
264 	/* Check the permissions. */
265 	if (lastcn && (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME)) {
266 		error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred);
267 		if (error)
268 			goto out;
269 
270 		if ((dnode->tn_mode & S_ISTXT) != 0) {
271 			error = kauth_authorize_vnode(cnp->cn_cred,
272 			    KAUTH_VNODE_DELETE, tnode->tn_vnode,
273 			    dnode->tn_vnode, genfs_can_sticky(dvp, cnp->cn_cred,
274 			    dnode->tn_uid, tnode->tn_uid));
275 			if (error) {
276 				error = EPERM;
277 				goto out;
278 			}
279 		}
280 	}
281 
282 	/* Get a vnode for the matching entry. */
283 	error = vcache_get(dvp->v_mount, &tnode, sizeof(tnode), vpp);
284 done:
285 	/*
286 	 * Cache the result, unless request was for creation (as it does
287 	 * not improve the performance).
288 	 */
289 	if (cnp->cn_nameiop != CREATE) {
290 		cache_enter(dvp, *vpp, cnp->cn_nameptr, cnp->cn_namelen,
291 			    cnp->cn_flags);
292 	}
293 out:
294 	KASSERT(VOP_ISLOCKED(dvp));
295 
296 	return error;
297 }
298 
299 int
300 tmpfs_create(void *v)
301 {
302 	struct vop_create_v3_args /* {
303 		struct vnode		*a_dvp;
304 		struct vnode		**a_vpp;
305 		struct componentname	*a_cnp;
306 		struct vattr		*a_vap;
307 	} */ *ap = v;
308 	vnode_t *dvp = ap->a_dvp, **vpp = ap->a_vpp;
309 	struct componentname *cnp = ap->a_cnp;
310 	struct vattr *vap = ap->a_vap;
311 
312 	KASSERT(VOP_ISLOCKED(dvp));
313 	KASSERT(vap->va_type == VREG || vap->va_type == VSOCK);
314 	return tmpfs_construct_node(dvp, vpp, vap, cnp, NULL);
315 }
316 
317 int
318 tmpfs_mknod(void *v)
319 {
320 	struct vop_mknod_v3_args /* {
321 		struct vnode		*a_dvp;
322 		struct vnode		**a_vpp;
323 		struct componentname	*a_cnp;
324 		struct vattr		*a_vap;
325 	} */ *ap = v;
326 	vnode_t *dvp = ap->a_dvp, **vpp = ap->a_vpp;
327 	struct componentname *cnp = ap->a_cnp;
328 	struct vattr *vap = ap->a_vap;
329 	enum vtype vt = vap->va_type;
330 
331 	if (vt != VBLK && vt != VCHR && vt != VFIFO) {
332 		*vpp = NULL;
333 		return EINVAL;
334 	}
335 	return tmpfs_construct_node(dvp, vpp, vap, cnp, NULL);
336 }
337 
338 int
339 tmpfs_open(void *v)
340 {
341 	struct vop_open_args /* {
342 		struct vnode	*a_vp;
343 		int		a_mode;
344 		kauth_cred_t	a_cred;
345 	} */ *ap = v;
346 	vnode_t *vp = ap->a_vp;
347 	mode_t mode = ap->a_mode;
348 	tmpfs_node_t *node;
349 
350 	KASSERT(VOP_ISLOCKED(vp));
351 
352 	node = VP_TO_TMPFS_NODE(vp);
353 
354 	/* If the file is marked append-only, deny write requests. */
355 	if ((node->tn_flags & APPEND) != 0 &&
356 	    (mode & (FWRITE | O_APPEND)) == FWRITE) {
357 		return EPERM;
358 	}
359 	return 0;
360 }
361 
362 int
363 tmpfs_close(void *v)
364 {
365 	struct vop_close_args /* {
366 		struct vnode	*a_vp;
367 		int		a_fflag;
368 		kauth_cred_t	a_cred;
369 	} */ *ap = v;
370 	vnode_t *vp __diagused = ap->a_vp;
371 
372 	KASSERT(VOP_ISLOCKED(vp));
373 	return 0;
374 }
375 
376 int
377 tmpfs_access(void *v)
378 {
379 	struct vop_access_args /* {
380 		struct vnode	*a_vp;
381 		accmode_t	a_accmode;
382 		kauth_cred_t	a_cred;
383 	} */ *ap = v;
384 	vnode_t *vp = ap->a_vp;
385 	accmode_t accmode = ap->a_accmode;
386 	kauth_cred_t cred = ap->a_cred;
387 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
388 	const bool writing = (accmode & VWRITE) != 0;
389 
390 	KASSERT(VOP_ISLOCKED(vp));
391 
392 	/* Possible? */
393 	switch (vp->v_type) {
394 	case VDIR:
395 	case VLNK:
396 	case VREG:
397 		if (writing && (vp->v_mount->mnt_flag & MNT_RDONLY) != 0) {
398 			return EROFS;
399 		}
400 		break;
401 	case VBLK:
402 	case VCHR:
403 	case VSOCK:
404 	case VFIFO:
405 		break;
406 	default:
407 		return EINVAL;
408 	}
409 	if (writing && (node->tn_flags & IMMUTABLE) != 0) {
410 		return EPERM;
411 	}
412 
413 	return kauth_authorize_vnode(cred, KAUTH_ACCESS_ACTION(accmode,
414 	    vp->v_type, node->tn_mode), vp, NULL, genfs_can_access(vp, cred,
415 	    node->tn_uid, node->tn_gid, node->tn_mode, NULL, accmode));
416 }
417 
418 int
419 tmpfs_getattr(void *v)
420 {
421 	struct vop_getattr_args /* {
422 		struct vnode	*a_vp;
423 		struct vattr	*a_vap;
424 		kauth_cred_t	a_cred;
425 	} */ *ap = v;
426 	vnode_t *vp = ap->a_vp;
427 	struct vattr *vap = ap->a_vap;
428 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
429 
430 	vattr_null(vap);
431 
432 	vap->va_type = vp->v_type;
433 	vap->va_mode = node->tn_mode;
434 	vap->va_nlink = node->tn_links;
435 	vap->va_uid = node->tn_uid;
436 	vap->va_gid = node->tn_gid;
437 	vap->va_fsid = vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
438 	vap->va_fileid = node->tn_id;
439 	vap->va_size = node->tn_size;
440 	vap->va_blocksize = PAGE_SIZE;
441 	vap->va_gen = TMPFS_NODE_GEN(node);
442 	vap->va_flags = node->tn_flags;
443 	vap->va_rdev = (vp->v_type == VBLK || vp->v_type == VCHR) ?
444 	    node->tn_spec.tn_dev.tn_rdev : VNOVAL;
445 	vap->va_bytes = round_page(node->tn_size);
446 	vap->va_filerev = VNOVAL;
447 	vap->va_vaflags = 0;
448 	vap->va_spare = VNOVAL; /* XXX */
449 
450 	mutex_enter(&node->tn_timelock);
451 	tmpfs_update_locked(vp, 0);
452 	vap->va_atime = node->tn_atime;
453 	vap->va_mtime = node->tn_mtime;
454 	vap->va_ctime = node->tn_ctime;
455 	vap->va_birthtime = node->tn_birthtime;
456 	mutex_exit(&node->tn_timelock);
457 
458 	return 0;
459 }
460 
461 int
462 tmpfs_setattr(void *v)
463 {
464 	struct vop_setattr_args /* {
465 		struct vnode	*a_vp;
466 		struct vattr	*a_vap;
467 		kauth_cred_t	a_cred;
468 	} */ *ap = v;
469 	vnode_t *vp = ap->a_vp;
470 	struct vattr *vap = ap->a_vap;
471 	kauth_cred_t cred = ap->a_cred;
472 	lwp_t *l = curlwp;
473 	int error = 0;
474 
475 	KASSERT(VOP_ISLOCKED(vp));
476 
477 	/* Abort if any unsettable attribute is given. */
478 	if (vap->va_type != VNON || vap->va_nlink != VNOVAL ||
479 	    vap->va_fsid != VNOVAL || vap->va_fileid != VNOVAL ||
480 	    vap->va_blocksize != VNOVAL || vap->va_ctime.tv_sec != VNOVAL ||
481 	    vap->va_gen != VNOVAL || vap->va_rdev != VNOVAL ||
482 	    vap->va_bytes != VNOVAL) {
483 		return EINVAL;
484 	}
485 
486 	if (error == 0 && vap->va_flags != VNOVAL)
487 		error = tmpfs_chflags(vp, vap->va_flags, cred, l);
488 
489 	if (error == 0 && vap->va_size != VNOVAL)
490 		error = tmpfs_chsize(vp, vap->va_size, cred, l);
491 
492 	if (error == 0 && (vap->va_uid != VNOVAL || vap->va_gid != VNOVAL))
493 		error = tmpfs_chown(vp, vap->va_uid, vap->va_gid, cred, l);
494 
495 	if (error == 0 && vap->va_mode != VNOVAL)
496 		error = tmpfs_chmod(vp, vap->va_mode, cred, l);
497 
498 	const bool chsometime =
499 	    vap->va_atime.tv_sec != VNOVAL ||
500 	    vap->va_mtime.tv_sec != VNOVAL ||
501 	    vap->va_birthtime.tv_sec != VNOVAL;
502 	if (error == 0 && chsometime) {
503 		error = tmpfs_chtimes(vp, &vap->va_atime, &vap->va_mtime,
504 		    &vap->va_birthtime, vap->va_vaflags, cred, l);
505 	}
506 	return error;
507 }
508 
509 int
510 tmpfs_read(void *v)
511 {
512 	struct vop_read_args /* {
513 		struct vnode *a_vp;
514 		struct uio *a_uio;
515 		int a_ioflag;
516 		kauth_cred_t a_cred;
517 	} */ *ap = v;
518 	vnode_t *vp = ap->a_vp;
519 	struct uio *uio = ap->a_uio;
520 	const int ioflag = ap->a_ioflag;
521 	tmpfs_node_t *node;
522 	struct uvm_object *uobj;
523 	int error;
524 
525 	KASSERT(VOP_ISLOCKED(vp));
526 
527 	if (vp->v_type == VDIR) {
528 		return EISDIR;
529 	}
530 	if (uio->uio_offset < 0 || vp->v_type != VREG) {
531 		return EINVAL;
532 	}
533 
534 	/* Note: reading zero bytes should not update atime. */
535 	if (uio->uio_resid == 0) {
536 		return 0;
537 	}
538 
539 	node = VP_TO_TMPFS_NODE(vp);
540 	uobj = node->tn_spec.tn_reg.tn_aobj;
541 	error = 0;
542 
543 	while (error == 0 && uio->uio_resid > 0) {
544 		vsize_t len;
545 
546 		if (node->tn_size <= uio->uio_offset) {
547 			break;
548 		}
549 		len = MIN(node->tn_size - uio->uio_offset, uio->uio_resid);
550 		if (len == 0) {
551 			break;
552 		}
553 		error = ubc_uiomove(uobj, uio, len, IO_ADV_DECODE(ioflag),
554 		    UBC_READ | UBC_PARTIALOK | UBC_VNODE_FLAGS(vp));
555 	}
556 
557 	tmpfs_update(vp, TMPFS_UPDATE_ATIME);
558 	return error;
559 }
560 
561 int
562 tmpfs_write(void *v)
563 {
564 	struct vop_write_args /* {
565 		struct vnode	*a_vp;
566 		struct uio	*a_uio;
567 		int		a_ioflag;
568 		kauth_cred_t	a_cred;
569 	} */ *ap = v;
570 	vnode_t *vp = ap->a_vp;
571 	struct uio *uio = ap->a_uio;
572 	const int ioflag = ap->a_ioflag;
573 	tmpfs_node_t *node;
574 	struct uvm_object *uobj;
575 	off_t oldsize;
576 	int error;
577 
578 	KASSERT(VOP_ISLOCKED(vp));
579 
580 	node = VP_TO_TMPFS_NODE(vp);
581 	oldsize = node->tn_size;
582 
583 	if ((vp->v_mount->mnt_flag & MNT_RDONLY) != 0) {
584 		error = EROFS;
585 		goto out;
586 	}
587 
588 	if (uio->uio_offset < 0 || vp->v_type != VREG) {
589 		error = EINVAL;
590 		goto out;
591 	}
592 	if (uio->uio_resid == 0) {
593 		error = 0;
594 		goto out;
595 	}
596 	if (ioflag & IO_APPEND) {
597 		uio->uio_offset = node->tn_size;
598 	}
599 
600 	if (uio->uio_offset + uio->uio_resid > node->tn_size) {
601 		error = tmpfs_reg_resize(vp, uio->uio_offset + uio->uio_resid);
602 		if (error)
603 			goto out;
604 	}
605 
606 	uobj = node->tn_spec.tn_reg.tn_aobj;
607 	error = 0;
608 	while (error == 0 && uio->uio_resid > 0) {
609 		vsize_t len;
610 
611 		len = MIN(node->tn_size - uio->uio_offset, uio->uio_resid);
612 		if (len == 0) {
613 			break;
614 		}
615 		error = ubc_uiomove(uobj, uio, len, IO_ADV_DECODE(ioflag),
616 		    UBC_WRITE | UBC_VNODE_FLAGS(vp));
617 	}
618 	if (error) {
619 		(void)tmpfs_reg_resize(vp, oldsize);
620 	}
621 
622 	tmpfs_update(vp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
623 	VN_KNOTE(vp, NOTE_WRITE);
624 out:
625 	if (error) {
626 		KASSERT(oldsize == node->tn_size);
627 	} else {
628 		KASSERT(uio->uio_resid == 0);
629 	}
630 	return error;
631 }
632 
633 int
634 tmpfs_fsync(void *v)
635 {
636 	struct vop_fsync_args /* {
637 		struct vnode *a_vp;
638 		kauth_cred_t a_cred;
639 		int a_flags;
640 		off_t a_offlo;
641 		off_t a_offhi;
642 		struct lwp *a_l;
643 	} */ *ap = v;
644 	vnode_t *vp __diagused = ap->a_vp;
645 
646 	/* Nothing to do.  Should be up to date. */
647 	KASSERT(VOP_ISLOCKED(vp));
648 	return 0;
649 }
650 
651 /*
652  * tmpfs_remove: unlink a file.
653  *
654  * => Both directory (dvp) and file (vp) are locked.
655  * => We unlock and drop the reference on both.
656  */
657 int
658 tmpfs_remove(void *v)
659 {
660 	struct vop_remove_v2_args /* {
661 		struct vnode *a_dvp;
662 		struct vnode *a_vp;
663 		struct componentname *a_cnp;
664 	} */ *ap = v;
665 	vnode_t *dvp = ap->a_dvp, *vp = ap->a_vp;
666 	tmpfs_node_t *dnode, *node;
667 	tmpfs_dirent_t *de;
668 	int error, tflags;
669 
670 	KASSERT(VOP_ISLOCKED(dvp));
671 	KASSERT(VOP_ISLOCKED(vp));
672 
673 	if (vp->v_type == VDIR) {
674 		error = EPERM;
675 		goto out;
676 	}
677 	dnode = VP_TO_TMPFS_DIR(dvp);
678 	node = VP_TO_TMPFS_NODE(vp);
679 
680 	/*
681 	 * Files marked as immutable or append-only cannot be deleted.
682 	 * Likewise, files residing on directories marked as append-only
683 	 * cannot be deleted.
684 	 */
685 	if (node->tn_flags & (IMMUTABLE | APPEND)) {
686 		error = EPERM;
687 		goto out;
688 	}
689 	if (dnode->tn_flags & APPEND) {
690 		error = EPERM;
691 		goto out;
692 	}
693 
694 	/* Lookup the directory entry (check the cached hint first). */
695 	de = tmpfs_dir_cached(node);
696 	if (de == NULL) {
697 		struct componentname *cnp = ap->a_cnp;
698 		de = tmpfs_dir_lookup(dnode, cnp);
699 	}
700 	KASSERT(de && de->td_node == node);
701 
702 	/*
703 	 * Remove the entry from the directory (drops the link count) and
704 	 * destroy it or replace with a whiteout.
705 	 *
706 	 * Note: the inode referred by it will not be destroyed until the
707 	 * vnode is reclaimed/recycled.
708 	 */
709 
710 	tmpfs_dir_detach(dnode, de);
711 
712 	if (ap->a_cnp->cn_flags & DOWHITEOUT)
713 		tmpfs_dir_attach(dnode, de, TMPFS_NODE_WHITEOUT);
714 	else
715 		tmpfs_free_dirent(VFS_TO_TMPFS(vp->v_mount), de);
716 
717 	tflags = TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME;
718 	if (node->tn_links > 0) {
719 		/* We removed a hard link. */
720 		tflags |= TMPFS_UPDATE_CTIME;
721 	}
722 	tmpfs_update(dvp, tflags);
723 	error = 0;
724 out:
725 	/* Drop the reference and unlock the node. */
726 	if (dvp == vp) {
727 		vrele(vp);
728 	} else {
729 		vput(vp);
730 	}
731 	return error;
732 }
733 
734 /*
735  * tmpfs_link: create a hard link.
736  */
737 int
738 tmpfs_link(void *v)
739 {
740 	struct vop_link_v2_args /* {
741 		struct vnode *a_dvp;
742 		struct vnode *a_vp;
743 		struct componentname *a_cnp;
744 	} */ *ap = v;
745 	vnode_t *dvp = ap->a_dvp;
746 	vnode_t *vp = ap->a_vp;
747 	struct componentname *cnp = ap->a_cnp;
748 	tmpfs_node_t *dnode, *node;
749 	tmpfs_dirent_t *de;
750 	int error;
751 
752 	KASSERT(dvp != vp);
753 	KASSERT(VOP_ISLOCKED(dvp));
754 	KASSERT(vp->v_type != VDIR);
755 	KASSERT(dvp->v_mount == vp->v_mount);
756 
757 	dnode = VP_TO_TMPFS_DIR(dvp);
758 	node = VP_TO_TMPFS_NODE(vp);
759 
760 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
761 
762 	/* Check for maximum number of links limit. */
763 	if (node->tn_links == LINK_MAX) {
764 		error = EMLINK;
765 		goto out;
766 	}
767 	KASSERT(node->tn_links < LINK_MAX);
768 
769 	/* We cannot create links of files marked immutable or append-only. */
770 	if (node->tn_flags & (IMMUTABLE | APPEND)) {
771 		error = EPERM;
772 		goto out;
773 	}
774 
775 	/* Allocate a new directory entry to represent the inode. */
776 	error = tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount),
777 	    cnp->cn_nameptr, cnp->cn_namelen, &de);
778 	if (error) {
779 		goto out;
780 	}
781 
782 	/*
783 	 * Insert the entry into the directory.
784 	 * It will increase the inode link count.
785 	 */
786 	tmpfs_dir_attach(dnode, de, node);
787 	tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
788 
789 	/* Update the timestamps and trigger the event. */
790 	if (node->tn_vnode) {
791 		VN_KNOTE(node->tn_vnode, NOTE_LINK);
792 	}
793 	tmpfs_update(vp, TMPFS_UPDATE_CTIME);
794 	error = 0;
795 out:
796 	VOP_UNLOCK(vp);
797 	return error;
798 }
799 
800 int
801 tmpfs_mkdir(void *v)
802 {
803 	struct vop_mkdir_v3_args /* {
804 		struct vnode		*a_dvp;
805 		struct vnode		**a_vpp;
806 		struct componentname	*a_cnp;
807 		struct vattr		*a_vap;
808 	} */ *ap = v;
809 	vnode_t *dvp = ap->a_dvp;
810 	vnode_t **vpp = ap->a_vpp;
811 	struct componentname *cnp = ap->a_cnp;
812 	struct vattr *vap = ap->a_vap;
813 
814 	KASSERT(vap->va_type == VDIR);
815 	return tmpfs_construct_node(dvp, vpp, vap, cnp, NULL);
816 }
817 
818 int
819 tmpfs_rmdir(void *v)
820 {
821 	struct vop_rmdir_v2_args /* {
822 		struct vnode		*a_dvp;
823 		struct vnode		*a_vp;
824 		struct componentname	*a_cnp;
825 	} */ *ap = v;
826 	vnode_t *dvp = ap->a_dvp;
827 	vnode_t *vp = ap->a_vp;
828 	tmpfs_mount_t *tmp = VFS_TO_TMPFS(dvp->v_mount);
829 	tmpfs_node_t *dnode = VP_TO_TMPFS_DIR(dvp);
830 	tmpfs_node_t *node = VP_TO_TMPFS_DIR(vp);
831 	tmpfs_dirent_t *de;
832 	int error = 0;
833 
834 	KASSERT(VOP_ISLOCKED(dvp));
835 	KASSERT(VOP_ISLOCKED(vp));
836 
837 	/*
838 	 * Directories with more than two entries ('.' and '..') cannot be
839 	 * removed.  There may be whiteout entries, which we will destroy.
840 	 */
841 	if (node->tn_size > 0) {
842 		/*
843 		 * If never had whiteout entries, the directory is certainly
844 		 * not empty.  Otherwise, scan for any non-whiteout entry.
845 		 */
846 		if ((node->tn_gen & TMPFS_WHITEOUT_BIT) == 0) {
847 			error = ENOTEMPTY;
848 			goto out;
849 		}
850 		TAILQ_FOREACH(de, &node->tn_spec.tn_dir.tn_dir, td_entries) {
851 			if (de->td_node != TMPFS_NODE_WHITEOUT) {
852 				error = ENOTEMPTY;
853 				goto out;
854 			}
855 		}
856 		KASSERT(error == 0);
857 	}
858 
859 	KASSERT(node->tn_spec.tn_dir.tn_parent == dnode);
860 
861 	/* Lookup the directory entry (check the cached hint first). */
862 	de = tmpfs_dir_cached(node);
863 	if (de == NULL) {
864 		struct componentname *cnp = ap->a_cnp;
865 		de = tmpfs_dir_lookup(dnode, cnp);
866 	}
867 	KASSERT(de && de->td_node == node);
868 
869 	/* Check flags to see if we are allowed to remove the directory. */
870 	if (dnode->tn_flags & APPEND || node->tn_flags & (IMMUTABLE | APPEND)) {
871 		error = EPERM;
872 		goto out;
873 	}
874 
875 	/* Decrement the link count for the virtual '.' entry. */
876 	node->tn_links--;
877 
878 	/* Detach the directory entry from the directory. */
879 	tmpfs_dir_detach(dnode, de);
880 
881 	/* Purge the cache for parent. */
882 	cache_purge(dvp);
883 
884 	/*
885 	 * Destroy the directory entry or replace it with a whiteout.
886 	 *
887 	 * Note: the inode referred by it will not be destroyed until the
888 	 * vnode is reclaimed.
889 	 */
890 	if (ap->a_cnp->cn_flags & DOWHITEOUT)
891 		tmpfs_dir_attach(dnode, de, TMPFS_NODE_WHITEOUT);
892 	else
893 		tmpfs_free_dirent(tmp, de);
894 
895 	/* Destroy the whiteout entries from the node. */
896 	while ((de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir)) != NULL) {
897 		KASSERT(de->td_node == TMPFS_NODE_WHITEOUT);
898 		tmpfs_dir_detach(node, de);
899 		tmpfs_free_dirent(tmp, de);
900 	}
901 	tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
902 
903 	KASSERT(node->tn_size == 0);
904 	KASSERT(node->tn_links == 0);
905 out:
906 	/* Release the node. */
907 	KASSERT(dvp != vp);
908 	vput(vp);
909 	return error;
910 }
911 
912 int
913 tmpfs_symlink(void *v)
914 {
915 	struct vop_symlink_v3_args /* {
916 		struct vnode		*a_dvp;
917 		struct vnode		**a_vpp;
918 		struct componentname	*a_cnp;
919 		struct vattr		*a_vap;
920 		char			*a_target;
921 	} */ *ap = v;
922 	vnode_t *dvp = ap->a_dvp;
923 	vnode_t **vpp = ap->a_vpp;
924 	struct componentname *cnp = ap->a_cnp;
925 	struct vattr *vap = ap->a_vap;
926 	char *target = ap->a_target;
927 
928 	KASSERT(vap->va_type == VLNK);
929 	return tmpfs_construct_node(dvp, vpp, vap, cnp, target);
930 }
931 
932 int
933 tmpfs_readdir(void *v)
934 {
935 	struct vop_readdir_args /* {
936 		struct vnode	*a_vp;
937 		struct uio	*a_uio;
938 		kauth_cred_t	a_cred;
939 		int		*a_eofflag;
940 		off_t		**a_cookies;
941 		int		*ncookies;
942 	} */ *ap = v;
943 	vnode_t *vp = ap->a_vp;
944 	struct uio *uio = ap->a_uio;
945 	int *eofflag = ap->a_eofflag;
946 	off_t **cookies = ap->a_cookies;
947 	int *ncookies = ap->a_ncookies;
948 	off_t startoff, cnt;
949 	tmpfs_node_t *node;
950 	int error;
951 
952 	KASSERT(VOP_ISLOCKED(vp));
953 
954 	/* This operation only makes sense on directory nodes. */
955 	if (vp->v_type != VDIR) {
956 		return ENOTDIR;
957 	}
958 	node = VP_TO_TMPFS_DIR(vp);
959 	startoff = uio->uio_offset;
960 	cnt = 0;
961 
962 	/*
963 	 * Retrieve the directory entries, unless it is being destroyed.
964 	 */
965 	if (node->tn_links) {
966 		error = tmpfs_dir_getdents(node, uio, &cnt);
967 	} else {
968 		error = 0;
969 	}
970 
971 	if (eofflag != NULL) {
972 		*eofflag = !error && uio->uio_offset == TMPFS_DIRSEQ_EOF;
973 	}
974 	if (error || cookies == NULL || ncookies == NULL) {
975 		return error;
976 	}
977 
978 	/* Update NFS-related variables, if any. */
979 	tmpfs_dirent_t *de = NULL;
980 	off_t i, off = startoff;
981 
982 	*cookies = malloc(cnt * sizeof(off_t), M_TEMP, M_WAITOK);
983 	*ncookies = cnt;
984 
985 	for (i = 0; i < cnt; i++) {
986 		KASSERT(off != TMPFS_DIRSEQ_EOF);
987 		if (off != TMPFS_DIRSEQ_DOT) {
988 			if (off == TMPFS_DIRSEQ_DOTDOT) {
989 				de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir);
990 			} else if (de != NULL) {
991 				de = TAILQ_NEXT(de, td_entries);
992 			} else {
993 				de = tmpfs_dir_lookupbyseq(node, off);
994 				KASSERT(de != NULL);
995 				de = TAILQ_NEXT(de, td_entries);
996 			}
997 			if (de == NULL) {
998 				off = TMPFS_DIRSEQ_EOF;
999 			} else {
1000 				off = tmpfs_dir_getseq(node, de);
1001 			}
1002 		} else {
1003 			off = TMPFS_DIRSEQ_DOTDOT;
1004 		}
1005 		(*cookies)[i] = off;
1006 	}
1007 	KASSERT(uio->uio_offset == off);
1008 	return error;
1009 }
1010 
1011 int
1012 tmpfs_readlink(void *v)
1013 {
1014 	struct vop_readlink_args /* {
1015 		struct vnode	*a_vp;
1016 		struct uio	*a_uio;
1017 		kauth_cred_t	a_cred;
1018 	} */ *ap = v;
1019 	vnode_t *vp = ap->a_vp;
1020 	struct uio *uio = ap->a_uio;
1021 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1022 	int error;
1023 
1024 	KASSERT(VOP_ISLOCKED(vp));
1025 	KASSERT(uio->uio_offset == 0);
1026 	KASSERT(vp->v_type == VLNK);
1027 
1028 	/* Note: readlink(2) returns the path without NUL terminator. */
1029 	if (node->tn_size > 0) {
1030 		error = uiomove(node->tn_spec.tn_lnk.tn_link,
1031 		    MIN(node->tn_size, uio->uio_resid), uio);
1032 	} else {
1033 		error = 0;
1034 	}
1035 	tmpfs_update(vp, TMPFS_UPDATE_ATIME);
1036 
1037 	return error;
1038 }
1039 
1040 int
1041 tmpfs_inactive(void *v)
1042 {
1043 	struct vop_inactive_v2_args /* {
1044 		struct vnode *a_vp;
1045 		bool *a_recycle;
1046 	} */ *ap = v;
1047 	vnode_t *vp = ap->a_vp;
1048 	tmpfs_node_t *node;
1049 	int error = 0;
1050 
1051 	KASSERT(VOP_ISLOCKED(vp));
1052 
1053 	node = VP_TO_TMPFS_NODE(vp);
1054 	if (node->tn_links == 0) {
1055 		/*
1056 		 * Mark node as dead by setting its generation to zero.
1057 		 */
1058 		atomic_and_32(&node->tn_gen, ~TMPFS_NODE_GEN_MASK);
1059 
1060 		/*
1061 		 * If the file has been deleted, truncate it, otherwise VFS
1062 		 * will quite rightly try to write back dirty data, which in
1063 		 * the case of tmpfs/UAO means needless page deactivations.
1064 		 */
1065 		if (vp->v_type == VREG) {
1066 			error = tmpfs_reg_resize(vp, 0);
1067 		}
1068 		*ap->a_recycle = true;
1069 	} else {
1070 		tmpfs_update(vp, 0);
1071 		*ap->a_recycle = false;
1072 	}
1073 
1074 	return error;
1075 }
1076 
1077 int
1078 tmpfs_reclaim(void *v)
1079 {
1080 	struct vop_reclaim_v2_args /* {
1081 		struct vnode *a_vp;
1082 	} */ *ap = v;
1083 	vnode_t *vp = ap->a_vp;
1084 	tmpfs_mount_t *tmp = VFS_TO_TMPFS(vp->v_mount);
1085 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1086 
1087 	/* Unlock vnode.  We still have exclusive access to it. */
1088 	VOP_UNLOCK(vp);
1089 
1090 	/* Disassociate inode from vnode. */
1091 	node->tn_vnode = NULL;
1092 	vp->v_data = NULL;
1093 
1094 	/* If inode is not referenced, i.e. no links, then destroy it. */
1095 	if (node->tn_links == 0)
1096 		tmpfs_free_node(tmp, node);
1097 	return 0;
1098 }
1099 
1100 int
1101 tmpfs_pathconf(void *v)
1102 {
1103 	struct vop_pathconf_args /* {
1104 		struct vnode	*a_vp;
1105 		int		a_name;
1106 		register_t	*a_retval;
1107 	} */ *ap = v;
1108 	const int name = ap->a_name;
1109 	register_t *retval = ap->a_retval;
1110 	int error = 0;
1111 
1112 	switch (name) {
1113 	case _PC_LINK_MAX:
1114 		*retval = LINK_MAX;
1115 		break;
1116 	case _PC_NAME_MAX:
1117 		*retval = TMPFS_MAXNAMLEN;
1118 		break;
1119 	case _PC_PATH_MAX:
1120 		*retval = PATH_MAX;
1121 		break;
1122 	case _PC_PIPE_BUF:
1123 		*retval = PIPE_BUF;
1124 		break;
1125 	case _PC_CHOWN_RESTRICTED:
1126 		*retval = 1;
1127 		break;
1128 	case _PC_NO_TRUNC:
1129 		*retval = 1;
1130 		break;
1131 	case _PC_SYNC_IO:
1132 		*retval = 1;
1133 		break;
1134 	case _PC_FILESIZEBITS:
1135 		*retval = sizeof(off_t) * CHAR_BIT;
1136 		break;
1137 	default:
1138 		error = EINVAL;
1139 	}
1140 	return error;
1141 }
1142 
1143 int
1144 tmpfs_advlock(void *v)
1145 {
1146 	struct vop_advlock_args /* {
1147 		struct vnode	*a_vp;
1148 		void *		a_id;
1149 		int		a_op;
1150 		struct flock	*a_fl;
1151 		int		a_flags;
1152 	} */ *ap = v;
1153 	vnode_t *vp = ap->a_vp;
1154 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1155 
1156 	return lf_advlock(v, &node->tn_lockf, node->tn_size);
1157 }
1158 
1159 int
1160 tmpfs_getpages(void *v)
1161 {
1162 	struct vop_getpages_args /* {
1163 		struct vnode *a_vp;
1164 		voff_t a_offset;
1165 		struct vm_page **a_m;
1166 		int *a_count;
1167 		int a_centeridx;
1168 		vm_prot_t a_access_type;
1169 		int a_advice;
1170 		int a_flags;
1171 	} */ * const ap = v;
1172 	vnode_t *vp = ap->a_vp;
1173 	const voff_t offset = ap->a_offset;
1174 	struct vm_page **pgs = ap->a_m;
1175 	const int centeridx = ap->a_centeridx;
1176 	const vm_prot_t access_type = ap->a_access_type;
1177 	const int advice = ap->a_advice;
1178 	const int flags = ap->a_flags;
1179 	int error, iflag, npages = *ap->a_count;
1180 	tmpfs_node_t *node;
1181 	struct uvm_object *uobj;
1182 
1183 	KASSERT(vp->v_type == VREG);
1184 	KASSERT(rw_lock_held(vp->v_uobj.vmobjlock));
1185 
1186 	/*
1187 	 * Currently, PGO_PASTEOF is not supported.
1188 	 */
1189 	if (vp->v_size <= offset + (centeridx << PAGE_SHIFT)) {
1190 		if ((flags & PGO_LOCKED) == 0)
1191 			rw_exit(vp->v_uobj.vmobjlock);
1192 		return EINVAL;
1193 	}
1194 
1195 	if (vp->v_size < offset + (npages << PAGE_SHIFT)) {
1196 		npages = (round_page(vp->v_size) - offset) >> PAGE_SHIFT;
1197 	}
1198 
1199 	/*
1200 	 * Check for reclaimed vnode.  v_interlock is not held here, but
1201 	 * VI_DEADCHECK is set with vmobjlock held.
1202 	 */
1203 	iflag = atomic_load_relaxed(&vp->v_iflag);
1204 	if (__predict_false((iflag & VI_DEADCHECK) != 0)) {
1205 		mutex_enter(vp->v_interlock);
1206 		error = vdead_check(vp, VDEAD_NOWAIT);
1207 		mutex_exit(vp->v_interlock);
1208 		if (error) {
1209 			if ((flags & PGO_LOCKED) == 0)
1210 				rw_exit(vp->v_uobj.vmobjlock);
1211 			return error;
1212 		}
1213 	}
1214 
1215 	node = VP_TO_TMPFS_NODE(vp);
1216 	uobj = node->tn_spec.tn_reg.tn_aobj;
1217 
1218 	/*
1219 	 * Update timestamp lazily.  The update will be made real when
1220 	 * a synchronous update is next made -- or by tmpfs_getattr,
1221 	 * tmpfs_putpages, and tmpfs_inactive.
1222 	 */
1223 	if ((flags & PGO_NOTIMESTAMP) == 0) {
1224 		u_int tflags = 0;
1225 
1226 		if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
1227 			tflags |= TMPFS_UPDATE_ATIME;
1228 
1229 		if ((access_type & VM_PROT_WRITE) != 0) {
1230 			tflags |= TMPFS_UPDATE_MTIME;
1231 			if (vp->v_mount->mnt_flag & MNT_RELATIME)
1232 				tflags |= TMPFS_UPDATE_ATIME;
1233 		}
1234 		tmpfs_update_lazily(vp, tflags);
1235 	}
1236 
1237 	/* Invoke the pager.  The vnode vmobjlock is shared with the UAO. */
1238 	KASSERT(vp->v_uobj.vmobjlock == uobj->vmobjlock);
1239 	error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, centeridx,
1240 	    access_type, advice, flags);
1241 #if defined(DEBUG)
1242 	if (!error && pgs) {
1243 		KASSERT(pgs[centeridx] != NULL);
1244 	}
1245 #endif
1246 	return error;
1247 }
1248 
1249 int
1250 tmpfs_putpages(void *v)
1251 {
1252 	struct vop_putpages_args /* {
1253 		struct vnode *a_vp;
1254 		voff_t a_offlo;
1255 		voff_t a_offhi;
1256 		int a_flags;
1257 	} */ * const ap = v;
1258 	vnode_t *vp = ap->a_vp;
1259 	const voff_t offlo = ap->a_offlo;
1260 	const voff_t offhi = ap->a_offhi;
1261 	const int flags = ap->a_flags;
1262 	tmpfs_node_t *node;
1263 	struct uvm_object *uobj;
1264 	int error;
1265 
1266 	KASSERT(rw_write_held(vp->v_uobj.vmobjlock));
1267 
1268 	if (vp->v_type != VREG) {
1269 		rw_exit(vp->v_uobj.vmobjlock);
1270 		return 0;
1271 	}
1272 
1273 	node = VP_TO_TMPFS_NODE(vp);
1274 	uobj = node->tn_spec.tn_reg.tn_aobj;
1275 
1276 	KASSERT(vp->v_uobj.vmobjlock == uobj->vmobjlock);
1277 	error = (*uobj->pgops->pgo_put)(uobj, offlo, offhi, flags);
1278 
1279 	/* XXX mtime */
1280 
1281 	/* Process deferred updates. */
1282 	tmpfs_update(vp, 0);
1283 	return error;
1284 }
1285 
1286 int
1287 tmpfs_whiteout(void *v)
1288 {
1289 	struct vop_whiteout_args /* {
1290 		struct vnode		*a_dvp;
1291 		struct componentname	*a_cnp;
1292 		int			a_flags;
1293 	} */ *ap = v;
1294 	vnode_t *dvp = ap->a_dvp;
1295 	struct componentname *cnp = ap->a_cnp;
1296 	const int flags = ap->a_flags;
1297 	tmpfs_mount_t *tmp = VFS_TO_TMPFS(dvp->v_mount);
1298 	tmpfs_node_t *dnode = VP_TO_TMPFS_DIR(dvp);
1299 	tmpfs_dirent_t *de;
1300 	int error;
1301 
1302 	switch (flags) {
1303 	case LOOKUP:
1304 		break;
1305 	case CREATE:
1306 		error = tmpfs_alloc_dirent(tmp, cnp->cn_nameptr,
1307 		    cnp->cn_namelen, &de);
1308 		if (error)
1309 			return error;
1310 		tmpfs_dir_attach(dnode, de, TMPFS_NODE_WHITEOUT);
1311 		break;
1312 	case DELETE:
1313 		cnp->cn_flags &= ~DOWHITEOUT; /* when in doubt, cargo cult */
1314 		de = tmpfs_dir_lookup(dnode, cnp);
1315 		if (de == NULL)
1316 			return ENOENT;
1317 		tmpfs_dir_detach(dnode, de);
1318 		tmpfs_free_dirent(tmp, de);
1319 		break;
1320 	}
1321 	tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
1322 	return 0;
1323 }
1324 
1325 int
1326 tmpfs_print(void *v)
1327 {
1328 	struct vop_print_args /* {
1329 		struct vnode	*a_vp;
1330 	} */ *ap = v;
1331 	vnode_t *vp = ap->a_vp;
1332 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1333 
1334 	printf("tag VT_TMPFS, tmpfs_node %p, flags 0x%x, links %d\n"
1335 	    "\tmode 0%o, owner %d, group %d, size %" PRIdMAX,
1336 	    node, node->tn_flags, node->tn_links, node->tn_mode, node->tn_uid,
1337 	    node->tn_gid, (uintmax_t)node->tn_size);
1338 	if (vp->v_type == VFIFO) {
1339 		VOCALL(fifo_vnodeop_p, VOFFSET(vop_print), v);
1340 	}
1341 	printf("\n");
1342 	return 0;
1343 }
1344