xref: /netbsd-src/sys/fs/tmpfs/tmpfs_vnops.c (revision 627f7eb200a4419d89b531d55fccd2ee3ffdcde0)
1 /*	$NetBSD: tmpfs_vnops.c,v 1.145 2020/12/13 19:22:02 chs 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 1.145 2020/12/13 19:22:02 chs 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_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, ubc_flags;
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 	/*
607 	 * If we're extending the file and have data to write that would
608 	 * not leave an un-zeroed hole, we can avoid fault processing and
609 	 * zeroing of pages on allocation.
610 	 *
611 	 * Don't do this if the file is mapped and we need to touch an
612 	 * existing page, because writing a mapping of the file into itself
613 	 * could cause a deadlock on PG_BUSY.
614 	 *
615 	 * New pages will not become visible until finished here (because
616 	 * of PG_BUSY and the vnode lock).
617 	 */
618 	ubc_flags = UBC_WRITE | UBC_VNODE_FLAGS(vp);
619 #if 0
620 	/*
621 	 * XXX disable use of UBC_FAULTBUSY for now, this check is insufficient
622 	 * because it does not zero uninitialized parts of pages in all of
623 	 * the cases where zeroing is needed.
624 	 */
625 	if (uio->uio_offset >= oldsize &&
626 	    ((uio->uio_offset & (PAGE_SIZE - 1)) == 0 ||
627 	    ((vp->v_vflag & VV_MAPPED) == 0 &&
628 	    trunc_page(uio->uio_offset) == trunc_page(oldsize)))) {
629 		ubc_flags |= UBC_FAULTBUSY;
630 	}
631 #endif
632 
633 	uobj = node->tn_spec.tn_reg.tn_aobj;
634 	error = 0;
635 	while (error == 0 && uio->uio_resid > 0) {
636 		vsize_t len;
637 
638 		len = MIN(node->tn_size - uio->uio_offset, uio->uio_resid);
639 		if (len == 0) {
640 			break;
641 		}
642 		error = ubc_uiomove(uobj, uio, len, IO_ADV_DECODE(ioflag),
643 		    ubc_flags);
644 	}
645 	if (error) {
646 		(void)tmpfs_reg_resize(vp, oldsize);
647 	}
648 
649 	tmpfs_update(vp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
650 	VN_KNOTE(vp, NOTE_WRITE);
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_v2_args /* {
688 		struct vnode *a_dvp;
689 		struct vnode *a_vp;
690 		struct componentname *a_cnp;
691 	} */ *ap = v;
692 	vnode_t *dvp = ap->a_dvp, *vp = ap->a_vp;
693 	tmpfs_node_t *dnode, *node;
694 	tmpfs_dirent_t *de;
695 	int error, tflags;
696 
697 	KASSERT(VOP_ISLOCKED(dvp));
698 	KASSERT(VOP_ISLOCKED(vp));
699 
700 	if (vp->v_type == VDIR) {
701 		error = EPERM;
702 		goto out;
703 	}
704 	dnode = VP_TO_TMPFS_DIR(dvp);
705 	node = VP_TO_TMPFS_NODE(vp);
706 
707 	/*
708 	 * Files marked as immutable or append-only cannot be deleted.
709 	 * Likewise, files residing on directories marked as append-only
710 	 * cannot be deleted.
711 	 */
712 	if (node->tn_flags & (IMMUTABLE | APPEND)) {
713 		error = EPERM;
714 		goto out;
715 	}
716 	if (dnode->tn_flags & APPEND) {
717 		error = EPERM;
718 		goto out;
719 	}
720 
721 	/* Lookup the directory entry (check the cached hint first). */
722 	de = tmpfs_dir_cached(node);
723 	if (de == NULL) {
724 		struct componentname *cnp = ap->a_cnp;
725 		de = tmpfs_dir_lookup(dnode, cnp);
726 	}
727 	KASSERT(de && de->td_node == node);
728 
729 	/*
730 	 * Remove the entry from the directory (drops the link count) and
731 	 * destroy it or replace with a whiteout.
732 	 *
733 	 * Note: the inode referred by it will not be destroyed until the
734 	 * vnode is reclaimed/recycled.
735 	 */
736 
737 	tmpfs_dir_detach(dnode, de);
738 
739 	if (ap->a_cnp->cn_flags & DOWHITEOUT)
740 		tmpfs_dir_attach(dnode, de, TMPFS_NODE_WHITEOUT);
741 	else
742 		tmpfs_free_dirent(VFS_TO_TMPFS(vp->v_mount), de);
743 
744 	tflags = TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME;
745 	if (node->tn_links > 0) {
746 		/* We removed a hard link. */
747 		tflags |= TMPFS_UPDATE_CTIME;
748 	}
749 	tmpfs_update(dvp, tflags);
750 	error = 0;
751 out:
752 	/* Drop the reference and unlock the node. */
753 	if (dvp == vp) {
754 		vrele(vp);
755 	} else {
756 		vput(vp);
757 	}
758 	return error;
759 }
760 
761 /*
762  * tmpfs_link: create a hard link.
763  */
764 int
765 tmpfs_link(void *v)
766 {
767 	struct vop_link_v2_args /* {
768 		struct vnode *a_dvp;
769 		struct vnode *a_vp;
770 		struct componentname *a_cnp;
771 	} */ *ap = v;
772 	vnode_t *dvp = ap->a_dvp;
773 	vnode_t *vp = ap->a_vp;
774 	struct componentname *cnp = ap->a_cnp;
775 	tmpfs_node_t *dnode, *node;
776 	tmpfs_dirent_t *de;
777 	int error;
778 
779 	KASSERT(dvp != vp);
780 	KASSERT(VOP_ISLOCKED(dvp));
781 	KASSERT(vp->v_type != VDIR);
782 	KASSERT(dvp->v_mount == vp->v_mount);
783 
784 	dnode = VP_TO_TMPFS_DIR(dvp);
785 	node = VP_TO_TMPFS_NODE(vp);
786 
787 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
788 
789 	/* Check for maximum number of links limit. */
790 	if (node->tn_links == LINK_MAX) {
791 		error = EMLINK;
792 		goto out;
793 	}
794 	KASSERT(node->tn_links < LINK_MAX);
795 
796 	/* We cannot create links of files marked immutable or append-only. */
797 	if (node->tn_flags & (IMMUTABLE | APPEND)) {
798 		error = EPERM;
799 		goto out;
800 	}
801 
802 	/* Allocate a new directory entry to represent the inode. */
803 	error = tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount),
804 	    cnp->cn_nameptr, cnp->cn_namelen, &de);
805 	if (error) {
806 		goto out;
807 	}
808 
809 	/*
810 	 * Insert the entry into the directory.
811 	 * It will increase the inode link count.
812 	 */
813 	tmpfs_dir_attach(dnode, de, node);
814 	tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
815 
816 	/* Update the timestamps and trigger the event. */
817 	if (node->tn_vnode) {
818 		VN_KNOTE(node->tn_vnode, NOTE_LINK);
819 	}
820 	tmpfs_update(vp, TMPFS_UPDATE_CTIME);
821 	error = 0;
822 out:
823 	VOP_UNLOCK(vp);
824 	return error;
825 }
826 
827 int
828 tmpfs_mkdir(void *v)
829 {
830 	struct vop_mkdir_v3_args /* {
831 		struct vnode		*a_dvp;
832 		struct vnode		**a_vpp;
833 		struct componentname	*a_cnp;
834 		struct vattr		*a_vap;
835 	} */ *ap = v;
836 	vnode_t *dvp = ap->a_dvp;
837 	vnode_t **vpp = ap->a_vpp;
838 	struct componentname *cnp = ap->a_cnp;
839 	struct vattr *vap = ap->a_vap;
840 
841 	KASSERT(vap->va_type == VDIR);
842 	return tmpfs_construct_node(dvp, vpp, vap, cnp, NULL);
843 }
844 
845 int
846 tmpfs_rmdir(void *v)
847 {
848 	struct vop_rmdir_v2_args /* {
849 		struct vnode		*a_dvp;
850 		struct vnode		*a_vp;
851 		struct componentname	*a_cnp;
852 	} */ *ap = v;
853 	vnode_t *dvp = ap->a_dvp;
854 	vnode_t *vp = ap->a_vp;
855 	tmpfs_mount_t *tmp = VFS_TO_TMPFS(dvp->v_mount);
856 	tmpfs_node_t *dnode = VP_TO_TMPFS_DIR(dvp);
857 	tmpfs_node_t *node = VP_TO_TMPFS_DIR(vp);
858 	tmpfs_dirent_t *de;
859 	int error = 0;
860 
861 	KASSERT(VOP_ISLOCKED(dvp));
862 	KASSERT(VOP_ISLOCKED(vp));
863 
864 	/*
865 	 * Directories with more than two entries ('.' and '..') cannot be
866 	 * removed.  There may be whiteout entries, which we will destroy.
867 	 */
868 	if (node->tn_size > 0) {
869 		/*
870 		 * If never had whiteout entries, the directory is certainly
871 		 * not empty.  Otherwise, scan for any non-whiteout entry.
872 		 */
873 		if ((node->tn_gen & TMPFS_WHITEOUT_BIT) == 0) {
874 			error = ENOTEMPTY;
875 			goto out;
876 		}
877 		TAILQ_FOREACH(de, &node->tn_spec.tn_dir.tn_dir, td_entries) {
878 			if (de->td_node != TMPFS_NODE_WHITEOUT) {
879 				error = ENOTEMPTY;
880 				goto out;
881 			}
882 		}
883 		KASSERT(error == 0);
884 	}
885 
886 	KASSERT(node->tn_spec.tn_dir.tn_parent == dnode);
887 
888 	/* Lookup the directory entry (check the cached hint first). */
889 	de = tmpfs_dir_cached(node);
890 	if (de == NULL) {
891 		struct componentname *cnp = ap->a_cnp;
892 		de = tmpfs_dir_lookup(dnode, cnp);
893 	}
894 	KASSERT(de && de->td_node == node);
895 
896 	/* Check flags to see if we are allowed to remove the directory. */
897 	if (dnode->tn_flags & APPEND || node->tn_flags & (IMMUTABLE | APPEND)) {
898 		error = EPERM;
899 		goto out;
900 	}
901 
902 	/* Decrement the link count for the virtual '.' entry. */
903 	node->tn_links--;
904 
905 	/* Detach the directory entry from the directory. */
906 	tmpfs_dir_detach(dnode, de);
907 
908 	/* Purge the cache for parent. */
909 	cache_purge(dvp);
910 
911 	/*
912 	 * Destroy the directory entry or replace it with a whiteout.
913 	 *
914 	 * Note: the inode referred by it will not be destroyed until the
915 	 * vnode is reclaimed.
916 	 */
917 	if (ap->a_cnp->cn_flags & DOWHITEOUT)
918 		tmpfs_dir_attach(dnode, de, TMPFS_NODE_WHITEOUT);
919 	else
920 		tmpfs_free_dirent(tmp, de);
921 
922 	/* Destroy the whiteout entries from the node. */
923 	while ((de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir)) != NULL) {
924 		KASSERT(de->td_node == TMPFS_NODE_WHITEOUT);
925 		tmpfs_dir_detach(node, de);
926 		tmpfs_free_dirent(tmp, de);
927 	}
928 	tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
929 
930 	KASSERT(node->tn_size == 0);
931 	KASSERT(node->tn_links == 0);
932 out:
933 	/* Release the node. */
934 	KASSERT(dvp != vp);
935 	vput(vp);
936 	return error;
937 }
938 
939 int
940 tmpfs_symlink(void *v)
941 {
942 	struct vop_symlink_v3_args /* {
943 		struct vnode		*a_dvp;
944 		struct vnode		**a_vpp;
945 		struct componentname	*a_cnp;
946 		struct vattr		*a_vap;
947 		char			*a_target;
948 	} */ *ap = v;
949 	vnode_t *dvp = ap->a_dvp;
950 	vnode_t **vpp = ap->a_vpp;
951 	struct componentname *cnp = ap->a_cnp;
952 	struct vattr *vap = ap->a_vap;
953 	char *target = ap->a_target;
954 
955 	KASSERT(vap->va_type == VLNK);
956 	return tmpfs_construct_node(dvp, vpp, vap, cnp, target);
957 }
958 
959 int
960 tmpfs_readdir(void *v)
961 {
962 	struct vop_readdir_args /* {
963 		struct vnode	*a_vp;
964 		struct uio	*a_uio;
965 		kauth_cred_t	a_cred;
966 		int		*a_eofflag;
967 		off_t		**a_cookies;
968 		int		*ncookies;
969 	} */ *ap = v;
970 	vnode_t *vp = ap->a_vp;
971 	struct uio *uio = ap->a_uio;
972 	int *eofflag = ap->a_eofflag;
973 	off_t **cookies = ap->a_cookies;
974 	int *ncookies = ap->a_ncookies;
975 	off_t startoff, cnt;
976 	tmpfs_node_t *node;
977 	int error;
978 
979 	KASSERT(VOP_ISLOCKED(vp));
980 
981 	/* This operation only makes sense on directory nodes. */
982 	if (vp->v_type != VDIR) {
983 		return ENOTDIR;
984 	}
985 	node = VP_TO_TMPFS_DIR(vp);
986 	startoff = uio->uio_offset;
987 	cnt = 0;
988 
989 	/*
990 	 * Retrieve the directory entries, unless it is being destroyed.
991 	 */
992 	if (node->tn_links) {
993 		error = tmpfs_dir_getdents(node, uio, &cnt);
994 	} else {
995 		error = 0;
996 	}
997 
998 	if (eofflag != NULL) {
999 		*eofflag = !error && uio->uio_offset == TMPFS_DIRSEQ_EOF;
1000 	}
1001 	if (error || cookies == NULL || ncookies == NULL) {
1002 		return error;
1003 	}
1004 
1005 	/* Update NFS-related variables, if any. */
1006 	tmpfs_dirent_t *de = NULL;
1007 	off_t i, off = startoff;
1008 
1009 	*cookies = malloc(cnt * sizeof(off_t), M_TEMP, M_WAITOK);
1010 	*ncookies = cnt;
1011 
1012 	for (i = 0; i < cnt; i++) {
1013 		KASSERT(off != TMPFS_DIRSEQ_EOF);
1014 		if (off != TMPFS_DIRSEQ_DOT) {
1015 			if (off == TMPFS_DIRSEQ_DOTDOT) {
1016 				de = TAILQ_FIRST(&node->tn_spec.tn_dir.tn_dir);
1017 			} else if (de != NULL) {
1018 				de = TAILQ_NEXT(de, td_entries);
1019 			} else {
1020 				de = tmpfs_dir_lookupbyseq(node, off);
1021 				KASSERT(de != NULL);
1022 				de = TAILQ_NEXT(de, td_entries);
1023 			}
1024 			if (de == NULL) {
1025 				off = TMPFS_DIRSEQ_EOF;
1026 			} else {
1027 				off = tmpfs_dir_getseq(node, de);
1028 			}
1029 		} else {
1030 			off = TMPFS_DIRSEQ_DOTDOT;
1031 		}
1032 		(*cookies)[i] = off;
1033 	}
1034 	KASSERT(uio->uio_offset == off);
1035 	return error;
1036 }
1037 
1038 int
1039 tmpfs_readlink(void *v)
1040 {
1041 	struct vop_readlink_args /* {
1042 		struct vnode	*a_vp;
1043 		struct uio	*a_uio;
1044 		kauth_cred_t	a_cred;
1045 	} */ *ap = v;
1046 	vnode_t *vp = ap->a_vp;
1047 	struct uio *uio = ap->a_uio;
1048 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1049 	int error;
1050 
1051 	KASSERT(VOP_ISLOCKED(vp));
1052 	KASSERT(uio->uio_offset == 0);
1053 	KASSERT(vp->v_type == VLNK);
1054 
1055 	/* Note: readlink(2) returns the path without NUL terminator. */
1056 	if (node->tn_size > 0) {
1057 		error = uiomove(node->tn_spec.tn_lnk.tn_link,
1058 		    MIN(node->tn_size, uio->uio_resid), uio);
1059 	} else {
1060 		error = 0;
1061 	}
1062 	tmpfs_update(vp, TMPFS_UPDATE_ATIME);
1063 
1064 	return error;
1065 }
1066 
1067 int
1068 tmpfs_inactive(void *v)
1069 {
1070 	struct vop_inactive_v2_args /* {
1071 		struct vnode *a_vp;
1072 		bool *a_recycle;
1073 	} */ *ap = v;
1074 	vnode_t *vp = ap->a_vp;
1075 	tmpfs_node_t *node;
1076 	int error = 0;
1077 
1078 	KASSERT(VOP_ISLOCKED(vp));
1079 
1080 	node = VP_TO_TMPFS_NODE(vp);
1081 	if (node->tn_links == 0) {
1082 		/*
1083 		 * Mark node as dead by setting its generation to zero.
1084 		 */
1085 		atomic_and_32(&node->tn_gen, ~TMPFS_NODE_GEN_MASK);
1086 
1087 		/*
1088 		 * If the file has been deleted, truncate it, otherwise VFS
1089 		 * will quite rightly try to write back dirty data, which in
1090 		 * the case of tmpfs/UAO means needless page deactivations.
1091 		 */
1092 		if (vp->v_type == VREG) {
1093 			error = tmpfs_reg_resize(vp, 0);
1094 		}
1095 		*ap->a_recycle = true;
1096 	} else {
1097 		tmpfs_update(vp, 0);
1098 		*ap->a_recycle = false;
1099 	}
1100 
1101 	return error;
1102 }
1103 
1104 int
1105 tmpfs_reclaim(void *v)
1106 {
1107 	struct vop_reclaim_v2_args /* {
1108 		struct vnode *a_vp;
1109 	} */ *ap = v;
1110 	vnode_t *vp = ap->a_vp;
1111 	tmpfs_mount_t *tmp = VFS_TO_TMPFS(vp->v_mount);
1112 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1113 
1114 	/* Unlock vnode.  We still have exclusive access to it. */
1115 	VOP_UNLOCK(vp);
1116 
1117 	/* Disassociate inode from vnode. */
1118 	node->tn_vnode = NULL;
1119 	vp->v_data = NULL;
1120 
1121 	/* If inode is not referenced, i.e. no links, then destroy it. */
1122 	if (node->tn_links == 0)
1123 		tmpfs_free_node(tmp, node);
1124 	return 0;
1125 }
1126 
1127 int
1128 tmpfs_pathconf(void *v)
1129 {
1130 	struct vop_pathconf_args /* {
1131 		struct vnode	*a_vp;
1132 		int		a_name;
1133 		register_t	*a_retval;
1134 	} */ *ap = v;
1135 	register_t *retval = ap->a_retval;
1136 
1137 	switch (ap->a_name) {
1138 	case _PC_LINK_MAX:
1139 		*retval = LINK_MAX;
1140 		return 0;
1141 	case _PC_NAME_MAX:
1142 		*retval = TMPFS_MAXNAMLEN;
1143 		return 0;
1144 	case _PC_PATH_MAX:
1145 		*retval = PATH_MAX;
1146 		return 0;
1147 	case _PC_PIPE_BUF:
1148 		*retval = PIPE_BUF;
1149 		return 0;
1150 	case _PC_CHOWN_RESTRICTED:
1151 		*retval = 1;
1152 		return 0;
1153 	case _PC_NO_TRUNC:
1154 		*retval = 1;
1155 		return 0;
1156 	case _PC_SYNC_IO:
1157 		*retval = 1;
1158 		return 0;
1159 	case _PC_FILESIZEBITS:
1160 		*retval = sizeof(off_t) * CHAR_BIT;
1161 		return 0;
1162 	default:
1163 		return genfs_pathconf(ap);
1164 	}
1165 }
1166 
1167 int
1168 tmpfs_advlock(void *v)
1169 {
1170 	struct vop_advlock_args /* {
1171 		struct vnode	*a_vp;
1172 		void *		a_id;
1173 		int		a_op;
1174 		struct flock	*a_fl;
1175 		int		a_flags;
1176 	} */ *ap = v;
1177 	vnode_t *vp = ap->a_vp;
1178 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1179 
1180 	return lf_advlock(v, &node->tn_lockf, node->tn_size);
1181 }
1182 
1183 int
1184 tmpfs_getpages(void *v)
1185 {
1186 	struct vop_getpages_args /* {
1187 		struct vnode *a_vp;
1188 		voff_t a_offset;
1189 		struct vm_page **a_m;
1190 		int *a_count;
1191 		int a_centeridx;
1192 		vm_prot_t a_access_type;
1193 		int a_advice;
1194 		int a_flags;
1195 	} */ * const ap = v;
1196 	vnode_t *vp = ap->a_vp;
1197 	const voff_t offset = ap->a_offset;
1198 	struct vm_page **pgs = ap->a_m;
1199 	const int centeridx = ap->a_centeridx;
1200 	const vm_prot_t access_type = ap->a_access_type;
1201 	const int advice = ap->a_advice;
1202 	const int flags = ap->a_flags;
1203 	int error, iflag, npages = *ap->a_count;
1204 	tmpfs_node_t *node;
1205 	struct uvm_object *uobj;
1206 
1207 	KASSERT(vp->v_type == VREG);
1208 	KASSERT(rw_lock_held(vp->v_uobj.vmobjlock));
1209 
1210 	/*
1211 	 * Currently, PGO_PASTEOF is not supported.
1212 	 */
1213 	if (vp->v_size <= offset + (centeridx << PAGE_SHIFT)) {
1214 		if ((flags & PGO_LOCKED) == 0)
1215 			rw_exit(vp->v_uobj.vmobjlock);
1216 		return EINVAL;
1217 	}
1218 
1219 	if (vp->v_size < offset + (npages << PAGE_SHIFT)) {
1220 		npages = (round_page(vp->v_size) - offset) >> PAGE_SHIFT;
1221 	}
1222 
1223 	/*
1224 	 * Check for reclaimed vnode.  v_interlock is not held here, but
1225 	 * VI_DEADCHECK is set with vmobjlock held.
1226 	 */
1227 	iflag = atomic_load_relaxed(&vp->v_iflag);
1228 	if (__predict_false((iflag & VI_DEADCHECK) != 0)) {
1229 		mutex_enter(vp->v_interlock);
1230 		error = vdead_check(vp, VDEAD_NOWAIT);
1231 		mutex_exit(vp->v_interlock);
1232 		if (error) {
1233 			if ((flags & PGO_LOCKED) == 0)
1234 				rw_exit(vp->v_uobj.vmobjlock);
1235 			return error;
1236 		}
1237 	}
1238 
1239 	node = VP_TO_TMPFS_NODE(vp);
1240 	uobj = node->tn_spec.tn_reg.tn_aobj;
1241 
1242 	/*
1243 	 * Update timestamp lazily.  The update will be made real when
1244 	 * a synchronous update is next made -- or by tmpfs_getattr,
1245 	 * tmpfs_putpages, and tmpfs_inactive.
1246 	 */
1247 	if ((flags & PGO_NOTIMESTAMP) == 0) {
1248 		u_int tflags = 0;
1249 
1250 		if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
1251 			tflags |= TMPFS_UPDATE_ATIME;
1252 
1253 		if ((access_type & VM_PROT_WRITE) != 0) {
1254 			tflags |= TMPFS_UPDATE_MTIME;
1255 			if (vp->v_mount->mnt_flag & MNT_RELATIME)
1256 				tflags |= TMPFS_UPDATE_ATIME;
1257 		}
1258 		tmpfs_update_lazily(vp, tflags);
1259 	}
1260 
1261 	/* Invoke the pager.  The vnode vmobjlock is shared with the UAO. */
1262 	KASSERT(vp->v_uobj.vmobjlock == uobj->vmobjlock);
1263 	error = (*uobj->pgops->pgo_get)(uobj, offset, pgs, &npages, centeridx,
1264 	    access_type, advice, flags);
1265 #if defined(DEBUG)
1266 	if (!error && pgs) {
1267 		KASSERT(pgs[centeridx] != NULL);
1268 	}
1269 #endif
1270 	return error;
1271 }
1272 
1273 int
1274 tmpfs_putpages(void *v)
1275 {
1276 	struct vop_putpages_args /* {
1277 		struct vnode *a_vp;
1278 		voff_t a_offlo;
1279 		voff_t a_offhi;
1280 		int a_flags;
1281 	} */ * const ap = v;
1282 	vnode_t *vp = ap->a_vp;
1283 	const voff_t offlo = ap->a_offlo;
1284 	const voff_t offhi = ap->a_offhi;
1285 	const int flags = ap->a_flags;
1286 	tmpfs_node_t *node;
1287 	struct uvm_object *uobj;
1288 	int error;
1289 
1290 	KASSERT(rw_write_held(vp->v_uobj.vmobjlock));
1291 
1292 	if (vp->v_type != VREG) {
1293 		rw_exit(vp->v_uobj.vmobjlock);
1294 		return 0;
1295 	}
1296 
1297 	node = VP_TO_TMPFS_NODE(vp);
1298 	uobj = node->tn_spec.tn_reg.tn_aobj;
1299 
1300 	KASSERT(vp->v_uobj.vmobjlock == uobj->vmobjlock);
1301 	error = (*uobj->pgops->pgo_put)(uobj, offlo, offhi, flags);
1302 
1303 	/* XXX mtime */
1304 
1305 	/* Process deferred updates. */
1306 	tmpfs_update(vp, 0);
1307 	return error;
1308 }
1309 
1310 int
1311 tmpfs_whiteout(void *v)
1312 {
1313 	struct vop_whiteout_args /* {
1314 		struct vnode		*a_dvp;
1315 		struct componentname	*a_cnp;
1316 		int			a_flags;
1317 	} */ *ap = v;
1318 	vnode_t *dvp = ap->a_dvp;
1319 	struct componentname *cnp = ap->a_cnp;
1320 	const int flags = ap->a_flags;
1321 	tmpfs_mount_t *tmp = VFS_TO_TMPFS(dvp->v_mount);
1322 	tmpfs_node_t *dnode = VP_TO_TMPFS_DIR(dvp);
1323 	tmpfs_dirent_t *de;
1324 	int error;
1325 
1326 	switch (flags) {
1327 	case LOOKUP:
1328 		break;
1329 	case CREATE:
1330 		error = tmpfs_alloc_dirent(tmp, cnp->cn_nameptr,
1331 		    cnp->cn_namelen, &de);
1332 		if (error)
1333 			return error;
1334 		tmpfs_dir_attach(dnode, de, TMPFS_NODE_WHITEOUT);
1335 		break;
1336 	case DELETE:
1337 		cnp->cn_flags &= ~DOWHITEOUT; /* when in doubt, cargo cult */
1338 		de = tmpfs_dir_lookup(dnode, cnp);
1339 		if (de == NULL)
1340 			return ENOENT;
1341 		tmpfs_dir_detach(dnode, de);
1342 		tmpfs_free_dirent(tmp, de);
1343 		break;
1344 	}
1345 	tmpfs_update(dvp, TMPFS_UPDATE_MTIME | TMPFS_UPDATE_CTIME);
1346 	return 0;
1347 }
1348 
1349 int
1350 tmpfs_print(void *v)
1351 {
1352 	struct vop_print_args /* {
1353 		struct vnode	*a_vp;
1354 	} */ *ap = v;
1355 	vnode_t *vp = ap->a_vp;
1356 	tmpfs_node_t *node = VP_TO_TMPFS_NODE(vp);
1357 
1358 	printf("tag VT_TMPFS, tmpfs_node %p, flags 0x%x, links %d\n"
1359 	    "\tmode 0%o, owner %d, group %d, size %" PRIdMAX,
1360 	    node, node->tn_flags, node->tn_links, node->tn_mode, node->tn_uid,
1361 	    node->tn_gid, (uintmax_t)node->tn_size);
1362 	if (vp->v_type == VFIFO) {
1363 		VOCALL(fifo_vnodeop_p, VOFFSET(vop_print), v);
1364 	}
1365 	printf("\n");
1366 	return 0;
1367 }
1368