xref: /freebsd/sys/fs/tmpfs/tmpfs_vnops.c (revision 98fc0505155575df4170c863107153df2a751a13)
1 /*	$NetBSD: tmpfs_vnops.c,v 1.39 2007/07/23 15:41:01 jmmv Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
5  *
6  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The NetBSD Foundation
10  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
11  * 2005 program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 /*
36  * tmpfs vnode interface.
37  */
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/param.h>
42 #include <sys/dirent.h>
43 #include <sys/fcntl.h>
44 #include <sys/limits.h>
45 #include <sys/lockf.h>
46 #include <sys/lock.h>
47 #include <sys/mount.h>
48 #include <sys/namei.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/rwlock.h>
52 #include <sys/sched.h>
53 #include <sys/stat.h>
54 #include <sys/systm.h>
55 #include <sys/sysctl.h>
56 #include <sys/unistd.h>
57 #include <sys/vnode.h>
58 
59 #include <vm/vm.h>
60 #include <vm/vm_param.h>
61 #include <vm/vm_object.h>
62 #include <vm/vm_page.h>
63 #include <vm/vm_pager.h>
64 
65 #include <fs/tmpfs/tmpfs_vnops.h>
66 #include <fs/tmpfs/tmpfs.h>
67 
68 SYSCTL_DECL(_vfs_tmpfs);
69 
70 static volatile int tmpfs_rename_restarts;
71 SYSCTL_INT(_vfs_tmpfs, OID_AUTO, rename_restarts, CTLFLAG_RD,
72     __DEVOLATILE(int *, &tmpfs_rename_restarts), 0,
73     "Times rename had to restart due to lock contention");
74 
75 static int
76 tmpfs_vn_get_ino_alloc(struct mount *mp, void *arg, int lkflags,
77     struct vnode **rvp)
78 {
79 
80 	return (tmpfs_alloc_vp(mp, arg, lkflags, rvp));
81 }
82 
83 static int
84 tmpfs_lookup1(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp)
85 {
86 	struct tmpfs_dirent *de;
87 	struct tmpfs_node *dnode, *pnode;
88 	struct tmpfs_mount *tm;
89 	int error;
90 
91 	dnode = VP_TO_TMPFS_DIR(dvp);
92 	*vpp = NULLVP;
93 
94 	/* Check accessibility of requested node as a first step. */
95 	error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_thread);
96 	if (error != 0)
97 		goto out;
98 
99 	/* We cannot be requesting the parent directory of the root node. */
100 	MPASS(IMPLIES(dnode->tn_type == VDIR &&
101 	    dnode->tn_dir.tn_parent == dnode,
102 	    !(cnp->cn_flags & ISDOTDOT)));
103 
104 	TMPFS_ASSERT_LOCKED(dnode);
105 	if (dnode->tn_dir.tn_parent == NULL) {
106 		error = ENOENT;
107 		goto out;
108 	}
109 	if (cnp->cn_flags & ISDOTDOT) {
110 		tm = VFS_TO_TMPFS(dvp->v_mount);
111 		pnode = dnode->tn_dir.tn_parent;
112 		tmpfs_ref_node(pnode);
113 		error = vn_vget_ino_gen(dvp, tmpfs_vn_get_ino_alloc,
114 		    pnode, cnp->cn_lkflags, vpp);
115 		tmpfs_free_node(tm, pnode);
116 		if (error != 0)
117 			goto out;
118 	} else if (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') {
119 		VREF(dvp);
120 		*vpp = dvp;
121 		error = 0;
122 	} else {
123 		de = tmpfs_dir_lookup(dnode, NULL, cnp);
124 		if (de != NULL && de->td_node == NULL)
125 			cnp->cn_flags |= ISWHITEOUT;
126 		if (de == NULL || de->td_node == NULL) {
127 			/*
128 			 * The entry was not found in the directory.
129 			 * This is OK if we are creating or renaming an
130 			 * entry and are working on the last component of
131 			 * the path name.
132 			 */
133 			if ((cnp->cn_flags & ISLASTCN) &&
134 			    (cnp->cn_nameiop == CREATE || \
135 			    cnp->cn_nameiop == RENAME ||
136 			    (cnp->cn_nameiop == DELETE &&
137 			    cnp->cn_flags & DOWHITEOUT &&
138 			    cnp->cn_flags & ISWHITEOUT))) {
139 				error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred,
140 				    cnp->cn_thread);
141 				if (error != 0)
142 					goto out;
143 
144 				/*
145 				 * Keep the component name in the buffer for
146 				 * future uses.
147 				 */
148 				cnp->cn_flags |= SAVENAME;
149 
150 				error = EJUSTRETURN;
151 			} else
152 				error = ENOENT;
153 		} else {
154 			struct tmpfs_node *tnode;
155 
156 			/*
157 			 * The entry was found, so get its associated
158 			 * tmpfs_node.
159 			 */
160 			tnode = de->td_node;
161 
162 			/*
163 			 * If we are not at the last path component and
164 			 * found a non-directory or non-link entry (which
165 			 * may itself be pointing to a directory), raise
166 			 * an error.
167 			 */
168 			if ((tnode->tn_type != VDIR &&
169 			    tnode->tn_type != VLNK) &&
170 			    !(cnp->cn_flags & ISLASTCN)) {
171 				error = ENOTDIR;
172 				goto out;
173 			}
174 
175 			/*
176 			 * If we are deleting or renaming the entry, keep
177 			 * track of its tmpfs_dirent so that it can be
178 			 * easily deleted later.
179 			 */
180 			if ((cnp->cn_flags & ISLASTCN) &&
181 			    (cnp->cn_nameiop == DELETE ||
182 			    cnp->cn_nameiop == RENAME)) {
183 				error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred,
184 				    cnp->cn_thread);
185 				if (error != 0)
186 					goto out;
187 
188 				/* Allocate a new vnode on the matching entry. */
189 				error = tmpfs_alloc_vp(dvp->v_mount, tnode,
190 				    cnp->cn_lkflags, vpp);
191 				if (error != 0)
192 					goto out;
193 
194 				if ((dnode->tn_mode & S_ISTXT) &&
195 				  VOP_ACCESS(dvp, VADMIN, cnp->cn_cred,
196 				  cnp->cn_thread) && VOP_ACCESS(*vpp, VADMIN,
197 				  cnp->cn_cred, cnp->cn_thread)) {
198 					error = EPERM;
199 					vput(*vpp);
200 					*vpp = NULL;
201 					goto out;
202 				}
203 				cnp->cn_flags |= SAVENAME;
204 			} else {
205 				error = tmpfs_alloc_vp(dvp->v_mount, tnode,
206 				    cnp->cn_lkflags, vpp);
207 				if (error != 0)
208 					goto out;
209 			}
210 		}
211 	}
212 
213 	/*
214 	 * Store the result of this lookup in the cache.  Avoid this if the
215 	 * request was for creation, as it does not improve timings on
216 	 * emprical tests.
217 	 */
218 	if ((cnp->cn_flags & MAKEENTRY) != 0 && tmpfs_use_nc(dvp))
219 		cache_enter(dvp, *vpp, cnp);
220 
221 out:
222 	/*
223 	 * If there were no errors, *vpp cannot be null and it must be
224 	 * locked.
225 	 */
226 	MPASS(IFF(error == 0, *vpp != NULLVP && VOP_ISLOCKED(*vpp)));
227 
228 	return (error);
229 }
230 
231 static int
232 tmpfs_cached_lookup(struct vop_cachedlookup_args *v)
233 {
234 
235 	return (tmpfs_lookup1(v->a_dvp, v->a_vpp, v->a_cnp));
236 }
237 
238 static int
239 tmpfs_lookup(struct vop_lookup_args *v)
240 {
241 
242 	return (tmpfs_lookup1(v->a_dvp, v->a_vpp, v->a_cnp));
243 }
244 
245 static int
246 tmpfs_create(struct vop_create_args *v)
247 {
248 	struct vnode *dvp = v->a_dvp;
249 	struct vnode **vpp = v->a_vpp;
250 	struct componentname *cnp = v->a_cnp;
251 	struct vattr *vap = v->a_vap;
252 	int error;
253 
254 	MPASS(vap->va_type == VREG || vap->va_type == VSOCK);
255 
256 	error = tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
257 	if (error == 0 && (cnp->cn_flags & MAKEENTRY) != 0 && tmpfs_use_nc(dvp))
258 		cache_enter(dvp, *vpp, cnp);
259 	return (error);
260 }
261 
262 static int
263 tmpfs_mknod(struct vop_mknod_args *v)
264 {
265 	struct vnode *dvp = v->a_dvp;
266 	struct vnode **vpp = v->a_vpp;
267 	struct componentname *cnp = v->a_cnp;
268 	struct vattr *vap = v->a_vap;
269 
270 	if (vap->va_type != VBLK && vap->va_type != VCHR &&
271 	    vap->va_type != VFIFO)
272 		return EINVAL;
273 
274 	return tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
275 }
276 
277 static int
278 tmpfs_open(struct vop_open_args *v)
279 {
280 	struct vnode *vp = v->a_vp;
281 	int mode = v->a_mode;
282 
283 	int error;
284 	struct tmpfs_node *node;
285 
286 	MPASS(VOP_ISLOCKED(vp));
287 
288 	node = VP_TO_TMPFS_NODE(vp);
289 
290 	/* The file is still active but all its names have been removed
291 	 * (e.g. by a "rmdir $(pwd)").  It cannot be opened any more as
292 	 * it is about to die. */
293 	if (node->tn_links < 1)
294 		return (ENOENT);
295 
296 	/* If the file is marked append-only, deny write requests. */
297 	if (node->tn_flags & APPEND && (mode & (FWRITE | O_APPEND)) == FWRITE)
298 		error = EPERM;
299 	else {
300 		error = 0;
301 		/* For regular files, the call below is nop. */
302 		KASSERT(vp->v_type != VREG || (node->tn_reg.tn_aobj->flags &
303 		    OBJ_DEAD) == 0, ("dead object"));
304 		vnode_create_vobject(vp, node->tn_size, v->a_td);
305 	}
306 
307 	MPASS(VOP_ISLOCKED(vp));
308 	return error;
309 }
310 
311 static int
312 tmpfs_close(struct vop_close_args *v)
313 {
314 	struct vnode *vp = v->a_vp;
315 
316 	/* Update node times. */
317 	tmpfs_update(vp);
318 
319 	return (0);
320 }
321 
322 int
323 tmpfs_access(struct vop_access_args *v)
324 {
325 	struct vnode *vp = v->a_vp;
326 	accmode_t accmode = v->a_accmode;
327 	struct ucred *cred = v->a_cred;
328 
329 	int error;
330 	struct tmpfs_node *node;
331 
332 	MPASS(VOP_ISLOCKED(vp));
333 
334 	node = VP_TO_TMPFS_NODE(vp);
335 
336 	switch (vp->v_type) {
337 	case VDIR:
338 		/* FALLTHROUGH */
339 	case VLNK:
340 		/* FALLTHROUGH */
341 	case VREG:
342 		if (accmode & VWRITE && vp->v_mount->mnt_flag & MNT_RDONLY) {
343 			error = EROFS;
344 			goto out;
345 		}
346 		break;
347 
348 	case VBLK:
349 		/* FALLTHROUGH */
350 	case VCHR:
351 		/* FALLTHROUGH */
352 	case VSOCK:
353 		/* FALLTHROUGH */
354 	case VFIFO:
355 		break;
356 
357 	default:
358 		error = EINVAL;
359 		goto out;
360 	}
361 
362 	if (accmode & VWRITE && node->tn_flags & IMMUTABLE) {
363 		error = EPERM;
364 		goto out;
365 	}
366 
367 	error = vaccess(vp->v_type, node->tn_mode, node->tn_uid,
368 	    node->tn_gid, accmode, cred, NULL);
369 
370 out:
371 	MPASS(VOP_ISLOCKED(vp));
372 
373 	return error;
374 }
375 
376 int
377 tmpfs_getattr(struct vop_getattr_args *v)
378 {
379 	struct vnode *vp = v->a_vp;
380 	struct vattr *vap = v->a_vap;
381 	vm_object_t obj;
382 	struct tmpfs_node *node;
383 
384 	node = VP_TO_TMPFS_NODE(vp);
385 
386 	tmpfs_update(vp);
387 
388 	vap->va_type = vp->v_type;
389 	vap->va_mode = node->tn_mode;
390 	vap->va_nlink = node->tn_links;
391 	vap->va_uid = node->tn_uid;
392 	vap->va_gid = node->tn_gid;
393 	vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
394 	vap->va_fileid = node->tn_id;
395 	vap->va_size = node->tn_size;
396 	vap->va_blocksize = PAGE_SIZE;
397 	vap->va_atime = node->tn_atime;
398 	vap->va_mtime = node->tn_mtime;
399 	vap->va_ctime = node->tn_ctime;
400 	vap->va_birthtime = node->tn_birthtime;
401 	vap->va_gen = node->tn_gen;
402 	vap->va_flags = node->tn_flags;
403 	vap->va_rdev = (vp->v_type == VBLK || vp->v_type == VCHR) ?
404 		node->tn_rdev : NODEV;
405 	if (vp->v_type == VREG) {
406 		obj = node->tn_reg.tn_aobj;
407 		vap->va_bytes = (u_quad_t)obj->resident_page_count * PAGE_SIZE;
408 	} else
409 		vap->va_bytes = node->tn_size;
410 	vap->va_filerev = 0;
411 
412 	return 0;
413 }
414 
415 int
416 tmpfs_setattr(struct vop_setattr_args *v)
417 {
418 	struct vnode *vp = v->a_vp;
419 	struct vattr *vap = v->a_vap;
420 	struct ucred *cred = v->a_cred;
421 	struct thread *td = curthread;
422 
423 	int error;
424 
425 	MPASS(VOP_ISLOCKED(vp));
426 
427 	error = 0;
428 
429 	/* Abort if any unsettable attribute is given. */
430 	if (vap->va_type != VNON ||
431 	    vap->va_nlink != VNOVAL ||
432 	    vap->va_fsid != VNOVAL ||
433 	    vap->va_fileid != VNOVAL ||
434 	    vap->va_blocksize != VNOVAL ||
435 	    vap->va_gen != VNOVAL ||
436 	    vap->va_rdev != VNOVAL ||
437 	    vap->va_bytes != VNOVAL)
438 		error = EINVAL;
439 
440 	if (error == 0 && (vap->va_flags != VNOVAL))
441 		error = tmpfs_chflags(vp, vap->va_flags, cred, td);
442 
443 	if (error == 0 && (vap->va_size != VNOVAL))
444 		error = tmpfs_chsize(vp, vap->va_size, cred, td);
445 
446 	if (error == 0 && (vap->va_uid != VNOVAL || vap->va_gid != VNOVAL))
447 		error = tmpfs_chown(vp, vap->va_uid, vap->va_gid, cred, td);
448 
449 	if (error == 0 && (vap->va_mode != (mode_t)VNOVAL))
450 		error = tmpfs_chmod(vp, vap->va_mode, cred, td);
451 
452 	if (error == 0 && ((vap->va_atime.tv_sec != VNOVAL &&
453 	    vap->va_atime.tv_nsec != VNOVAL) ||
454 	    (vap->va_mtime.tv_sec != VNOVAL &&
455 	    vap->va_mtime.tv_nsec != VNOVAL) ||
456 	    (vap->va_birthtime.tv_sec != VNOVAL &&
457 	    vap->va_birthtime.tv_nsec != VNOVAL)))
458 		error = tmpfs_chtimes(vp, vap, cred, td);
459 
460 	/* Update the node times.  We give preference to the error codes
461 	 * generated by this function rather than the ones that may arise
462 	 * from tmpfs_update. */
463 	tmpfs_update(vp);
464 
465 	MPASS(VOP_ISLOCKED(vp));
466 
467 	return error;
468 }
469 
470 static int
471 tmpfs_read(struct vop_read_args *v)
472 {
473 	struct vnode *vp;
474 	struct uio *uio;
475 	struct tmpfs_node *node;
476 
477 	vp = v->a_vp;
478 	if (vp->v_type != VREG)
479 		return (EISDIR);
480 	uio = v->a_uio;
481 	if (uio->uio_offset < 0)
482 		return (EINVAL);
483 	node = VP_TO_TMPFS_NODE(vp);
484 	tmpfs_set_status(node, TMPFS_NODE_ACCESSED);
485 	return (uiomove_object(node->tn_reg.tn_aobj, node->tn_size, uio));
486 }
487 
488 static int
489 tmpfs_write(struct vop_write_args *v)
490 {
491 	struct vnode *vp;
492 	struct uio *uio;
493 	struct tmpfs_node *node;
494 	off_t oldsize;
495 	int error, ioflag;
496 
497 	vp = v->a_vp;
498 	uio = v->a_uio;
499 	ioflag = v->a_ioflag;
500 	error = 0;
501 	node = VP_TO_TMPFS_NODE(vp);
502 	oldsize = node->tn_size;
503 
504 	if (uio->uio_offset < 0 || vp->v_type != VREG)
505 		return (EINVAL);
506 	if (uio->uio_resid == 0)
507 		return (0);
508 	if (ioflag & IO_APPEND)
509 		uio->uio_offset = node->tn_size;
510 	if (uio->uio_offset + uio->uio_resid >
511 	  VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
512 		return (EFBIG);
513 	if (vn_rlimit_fsize(vp, uio, uio->uio_td))
514 		return (EFBIG);
515 	if (uio->uio_offset + uio->uio_resid > node->tn_size) {
516 		error = tmpfs_reg_resize(vp, uio->uio_offset + uio->uio_resid,
517 		    FALSE);
518 		if (error != 0)
519 			goto out;
520 	}
521 
522 	error = uiomove_object(node->tn_reg.tn_aobj, node->tn_size, uio);
523 	node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
524 	    TMPFS_NODE_CHANGED;
525 	if (node->tn_mode & (S_ISUID | S_ISGID)) {
526 		if (priv_check_cred(v->a_cred, PRIV_VFS_RETAINSUGID, 0))
527 			node->tn_mode &= ~(S_ISUID | S_ISGID);
528 	}
529 	if (error != 0)
530 		(void)tmpfs_reg_resize(vp, oldsize, TRUE);
531 
532 out:
533 	MPASS(IMPLIES(error == 0, uio->uio_resid == 0));
534 	MPASS(IMPLIES(error != 0, oldsize == node->tn_size));
535 
536 	return (error);
537 }
538 
539 static int
540 tmpfs_fsync(struct vop_fsync_args *v)
541 {
542 	struct vnode *vp = v->a_vp;
543 
544 	MPASS(VOP_ISLOCKED(vp));
545 
546 	tmpfs_check_mtime(vp);
547 	tmpfs_update(vp);
548 
549 	return 0;
550 }
551 
552 static int
553 tmpfs_remove(struct vop_remove_args *v)
554 {
555 	struct vnode *dvp = v->a_dvp;
556 	struct vnode *vp = v->a_vp;
557 
558 	int error;
559 	struct tmpfs_dirent *de;
560 	struct tmpfs_mount *tmp;
561 	struct tmpfs_node *dnode;
562 	struct tmpfs_node *node;
563 
564 	MPASS(VOP_ISLOCKED(dvp));
565 	MPASS(VOP_ISLOCKED(vp));
566 
567 	if (vp->v_type == VDIR) {
568 		error = EISDIR;
569 		goto out;
570 	}
571 
572 	dnode = VP_TO_TMPFS_DIR(dvp);
573 	node = VP_TO_TMPFS_NODE(vp);
574 	tmp = VFS_TO_TMPFS(vp->v_mount);
575 	de = tmpfs_dir_lookup(dnode, node, v->a_cnp);
576 	MPASS(de != NULL);
577 
578 	/* Files marked as immutable or append-only cannot be deleted. */
579 	if ((node->tn_flags & (IMMUTABLE | APPEND | NOUNLINK)) ||
580 	    (dnode->tn_flags & APPEND)) {
581 		error = EPERM;
582 		goto out;
583 	}
584 
585 	/* Remove the entry from the directory; as it is a file, we do not
586 	 * have to change the number of hard links of the directory. */
587 	tmpfs_dir_detach(dvp, de);
588 	if (v->a_cnp->cn_flags & DOWHITEOUT)
589 		tmpfs_dir_whiteout_add(dvp, v->a_cnp);
590 
591 	/* Free the directory entry we just deleted.  Note that the node
592 	 * referred by it will not be removed until the vnode is really
593 	 * reclaimed. */
594 	tmpfs_free_dirent(tmp, de);
595 
596 	node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED;
597 	error = 0;
598 
599 out:
600 
601 	return error;
602 }
603 
604 static int
605 tmpfs_link(struct vop_link_args *v)
606 {
607 	struct vnode *dvp = v->a_tdvp;
608 	struct vnode *vp = v->a_vp;
609 	struct componentname *cnp = v->a_cnp;
610 
611 	int error;
612 	struct tmpfs_dirent *de;
613 	struct tmpfs_node *node;
614 
615 	MPASS(VOP_ISLOCKED(dvp));
616 	MPASS(cnp->cn_flags & HASBUF);
617 	MPASS(dvp != vp); /* XXX When can this be false? */
618 	node = VP_TO_TMPFS_NODE(vp);
619 
620 	/* Ensure that we do not overflow the maximum number of links imposed
621 	 * by the system. */
622 	MPASS(node->tn_links <= TMPFS_LINK_MAX);
623 	if (node->tn_links == TMPFS_LINK_MAX) {
624 		error = EMLINK;
625 		goto out;
626 	}
627 
628 	/* We cannot create links of files marked immutable or append-only. */
629 	if (node->tn_flags & (IMMUTABLE | APPEND)) {
630 		error = EPERM;
631 		goto out;
632 	}
633 
634 	/* Allocate a new directory entry to represent the node. */
635 	error = tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), node,
636 	    cnp->cn_nameptr, cnp->cn_namelen, &de);
637 	if (error != 0)
638 		goto out;
639 
640 	/* Insert the new directory entry into the appropriate directory. */
641 	if (cnp->cn_flags & ISWHITEOUT)
642 		tmpfs_dir_whiteout_remove(dvp, cnp);
643 	tmpfs_dir_attach(dvp, de);
644 
645 	/* vp link count has changed, so update node times. */
646 	node->tn_status |= TMPFS_NODE_CHANGED;
647 	tmpfs_update(vp);
648 
649 	error = 0;
650 
651 out:
652 	return error;
653 }
654 
655 /*
656  * We acquire all but fdvp locks using non-blocking acquisitions.  If we
657  * fail to acquire any lock in the path we will drop all held locks,
658  * acquire the new lock in a blocking fashion, and then release it and
659  * restart the rename.  This acquire/release step ensures that we do not
660  * spin on a lock waiting for release.  On error release all vnode locks
661  * and decrement references the way tmpfs_rename() would do.
662  */
663 static int
664 tmpfs_rename_relock(struct vnode *fdvp, struct vnode **fvpp,
665     struct vnode *tdvp, struct vnode **tvpp,
666     struct componentname *fcnp, struct componentname *tcnp)
667 {
668 	struct vnode *nvp;
669 	struct mount *mp;
670 	struct tmpfs_dirent *de;
671 	int error, restarts = 0;
672 
673 	VOP_UNLOCK(tdvp, 0);
674 	if (*tvpp != NULL && *tvpp != tdvp)
675 		VOP_UNLOCK(*tvpp, 0);
676 	mp = fdvp->v_mount;
677 
678 relock:
679 	restarts += 1;
680 	error = vn_lock(fdvp, LK_EXCLUSIVE);
681 	if (error)
682 		goto releout;
683 	if (vn_lock(tdvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
684 		VOP_UNLOCK(fdvp, 0);
685 		error = vn_lock(tdvp, LK_EXCLUSIVE);
686 		if (error)
687 			goto releout;
688 		VOP_UNLOCK(tdvp, 0);
689 		goto relock;
690 	}
691 	/*
692 	 * Re-resolve fvp to be certain it still exists and fetch the
693 	 * correct vnode.
694 	 */
695 	de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(fdvp), NULL, fcnp);
696 	if (de == NULL) {
697 		VOP_UNLOCK(fdvp, 0);
698 		VOP_UNLOCK(tdvp, 0);
699 		if ((fcnp->cn_flags & ISDOTDOT) != 0 ||
700 		    (fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.'))
701 			error = EINVAL;
702 		else
703 			error = ENOENT;
704 		goto releout;
705 	}
706 	error = tmpfs_alloc_vp(mp, de->td_node, LK_EXCLUSIVE | LK_NOWAIT, &nvp);
707 	if (error != 0) {
708 		VOP_UNLOCK(fdvp, 0);
709 		VOP_UNLOCK(tdvp, 0);
710 		if (error != EBUSY)
711 			goto releout;
712 		error = tmpfs_alloc_vp(mp, de->td_node, LK_EXCLUSIVE, &nvp);
713 		if (error != 0)
714 			goto releout;
715 		VOP_UNLOCK(nvp, 0);
716 		/*
717 		 * Concurrent rename race.
718 		 */
719 		if (nvp == tdvp) {
720 			vrele(nvp);
721 			error = EINVAL;
722 			goto releout;
723 		}
724 		vrele(*fvpp);
725 		*fvpp = nvp;
726 		goto relock;
727 	}
728 	vrele(*fvpp);
729 	*fvpp = nvp;
730 	VOP_UNLOCK(*fvpp, 0);
731 	/*
732 	 * Re-resolve tvp and acquire the vnode lock if present.
733 	 */
734 	de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(tdvp), NULL, tcnp);
735 	/*
736 	 * If tvp disappeared we just carry on.
737 	 */
738 	if (de == NULL && *tvpp != NULL) {
739 		vrele(*tvpp);
740 		*tvpp = NULL;
741 	}
742 	/*
743 	 * Get the tvp ino if the lookup succeeded.  We may have to restart
744 	 * if the non-blocking acquire fails.
745 	 */
746 	if (de != NULL) {
747 		nvp = NULL;
748 		error = tmpfs_alloc_vp(mp, de->td_node,
749 		    LK_EXCLUSIVE | LK_NOWAIT, &nvp);
750 		if (*tvpp != NULL)
751 			vrele(*tvpp);
752 		*tvpp = nvp;
753 		if (error != 0) {
754 			VOP_UNLOCK(fdvp, 0);
755 			VOP_UNLOCK(tdvp, 0);
756 			if (error != EBUSY)
757 				goto releout;
758 			error = tmpfs_alloc_vp(mp, de->td_node, LK_EXCLUSIVE,
759 			    &nvp);
760 			if (error != 0)
761 				goto releout;
762 			VOP_UNLOCK(nvp, 0);
763 			/*
764 			 * fdvp contains fvp, thus tvp (=fdvp) is not empty.
765 			 */
766 			if (nvp == fdvp) {
767 				error = ENOTEMPTY;
768 				goto releout;
769 			}
770 			goto relock;
771 		}
772 	}
773 	tmpfs_rename_restarts += restarts;
774 
775 	return (0);
776 
777 releout:
778 	vrele(fdvp);
779 	vrele(*fvpp);
780 	vrele(tdvp);
781 	if (*tvpp != NULL)
782 		vrele(*tvpp);
783 	tmpfs_rename_restarts += restarts;
784 
785 	return (error);
786 }
787 
788 static int
789 tmpfs_rename(struct vop_rename_args *v)
790 {
791 	struct vnode *fdvp = v->a_fdvp;
792 	struct vnode *fvp = v->a_fvp;
793 	struct componentname *fcnp = v->a_fcnp;
794 	struct vnode *tdvp = v->a_tdvp;
795 	struct vnode *tvp = v->a_tvp;
796 	struct componentname *tcnp = v->a_tcnp;
797 	struct mount *mp = NULL;
798 
799 	char *newname;
800 	int error;
801 	struct tmpfs_dirent *de;
802 	struct tmpfs_mount *tmp;
803 	struct tmpfs_node *fdnode;
804 	struct tmpfs_node *fnode;
805 	struct tmpfs_node *tnode;
806 	struct tmpfs_node *tdnode;
807 
808 	MPASS(VOP_ISLOCKED(tdvp));
809 	MPASS(IMPLIES(tvp != NULL, VOP_ISLOCKED(tvp)));
810 	MPASS(fcnp->cn_flags & HASBUF);
811 	MPASS(tcnp->cn_flags & HASBUF);
812 
813 	/* Disallow cross-device renames.
814 	 * XXX Why isn't this done by the caller? */
815 	if (fvp->v_mount != tdvp->v_mount ||
816 	    (tvp != NULL && fvp->v_mount != tvp->v_mount)) {
817 		error = EXDEV;
818 		goto out;
819 	}
820 
821 	/* If source and target are the same file, there is nothing to do. */
822 	if (fvp == tvp) {
823 		error = 0;
824 		goto out;
825 	}
826 
827 	/* If we need to move the directory between entries, lock the
828 	 * source so that we can safely operate on it. */
829 	if (fdvp != tdvp && fdvp != tvp) {
830 		if (vn_lock(fdvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
831 			mp = tdvp->v_mount;
832 			error = vfs_busy(mp, 0);
833 			if (error != 0) {
834 				mp = NULL;
835 				goto out;
836 			}
837 			error = tmpfs_rename_relock(fdvp, &fvp, tdvp, &tvp,
838 			    fcnp, tcnp);
839 			if (error != 0) {
840 				vfs_unbusy(mp);
841 				return (error);
842 			}
843 			ASSERT_VOP_ELOCKED(fdvp,
844 			    "tmpfs_rename: fdvp not locked");
845 			ASSERT_VOP_ELOCKED(tdvp,
846 			    "tmpfs_rename: tdvp not locked");
847 			if (tvp != NULL)
848 				ASSERT_VOP_ELOCKED(tvp,
849 				    "tmpfs_rename: tvp not locked");
850 			if (fvp == tvp) {
851 				error = 0;
852 				goto out_locked;
853 			}
854 		}
855 	}
856 
857 	tmp = VFS_TO_TMPFS(tdvp->v_mount);
858 	tdnode = VP_TO_TMPFS_DIR(tdvp);
859 	tnode = (tvp == NULL) ? NULL : VP_TO_TMPFS_NODE(tvp);
860 	fdnode = VP_TO_TMPFS_DIR(fdvp);
861 	fnode = VP_TO_TMPFS_NODE(fvp);
862 	de = tmpfs_dir_lookup(fdnode, fnode, fcnp);
863 
864 	/* Entry can disappear before we lock fdvp,
865 	 * also avoid manipulating '.' and '..' entries. */
866 	if (de == NULL) {
867 		if ((fcnp->cn_flags & ISDOTDOT) != 0 ||
868 		    (fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.'))
869 			error = EINVAL;
870 		else
871 			error = ENOENT;
872 		goto out_locked;
873 	}
874 	MPASS(de->td_node == fnode);
875 
876 	/* If re-naming a directory to another preexisting directory
877 	 * ensure that the target directory is empty so that its
878 	 * removal causes no side effects.
879 	 * Kern_rename guarantees the destination to be a directory
880 	 * if the source is one. */
881 	if (tvp != NULL) {
882 		MPASS(tnode != NULL);
883 
884 		if ((tnode->tn_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
885 		    (tdnode->tn_flags & (APPEND | IMMUTABLE))) {
886 			error = EPERM;
887 			goto out_locked;
888 		}
889 
890 		if (fnode->tn_type == VDIR && tnode->tn_type == VDIR) {
891 			if (tnode->tn_size > 0) {
892 				error = ENOTEMPTY;
893 				goto out_locked;
894 			}
895 		} else if (fnode->tn_type == VDIR && tnode->tn_type != VDIR) {
896 			error = ENOTDIR;
897 			goto out_locked;
898 		} else if (fnode->tn_type != VDIR && tnode->tn_type == VDIR) {
899 			error = EISDIR;
900 			goto out_locked;
901 		} else {
902 			MPASS(fnode->tn_type != VDIR &&
903 				tnode->tn_type != VDIR);
904 		}
905 	}
906 
907 	if ((fnode->tn_flags & (NOUNLINK | IMMUTABLE | APPEND))
908 	    || (fdnode->tn_flags & (APPEND | IMMUTABLE))) {
909 		error = EPERM;
910 		goto out_locked;
911 	}
912 
913 	/* Ensure that we have enough memory to hold the new name, if it
914 	 * has to be changed. */
915 	if (fcnp->cn_namelen != tcnp->cn_namelen ||
916 	    bcmp(fcnp->cn_nameptr, tcnp->cn_nameptr, fcnp->cn_namelen) != 0) {
917 		newname = malloc(tcnp->cn_namelen, M_TMPFSNAME, M_WAITOK);
918 	} else
919 		newname = NULL;
920 
921 	/* If the node is being moved to another directory, we have to do
922 	 * the move. */
923 	if (fdnode != tdnode) {
924 		/* In case we are moving a directory, we have to adjust its
925 		 * parent to point to the new parent. */
926 		if (de->td_node->tn_type == VDIR) {
927 			struct tmpfs_node *n;
928 
929 			/* Ensure the target directory is not a child of the
930 			 * directory being moved.  Otherwise, we'd end up
931 			 * with stale nodes. */
932 			n = tdnode;
933 			/* TMPFS_LOCK garanties that no nodes are freed while
934 			 * traversing the list. Nodes can only be marked as
935 			 * removed: tn_parent == NULL. */
936 			TMPFS_LOCK(tmp);
937 			TMPFS_NODE_LOCK(n);
938 			while (n != n->tn_dir.tn_parent) {
939 				struct tmpfs_node *parent;
940 
941 				if (n == fnode) {
942 					TMPFS_NODE_UNLOCK(n);
943 					TMPFS_UNLOCK(tmp);
944 					error = EINVAL;
945 					if (newname != NULL)
946 						    free(newname, M_TMPFSNAME);
947 					goto out_locked;
948 				}
949 				parent = n->tn_dir.tn_parent;
950 				TMPFS_NODE_UNLOCK(n);
951 				if (parent == NULL) {
952 					n = NULL;
953 					break;
954 				}
955 				TMPFS_NODE_LOCK(parent);
956 				if (parent->tn_dir.tn_parent == NULL) {
957 					TMPFS_NODE_UNLOCK(parent);
958 					n = NULL;
959 					break;
960 				}
961 				n = parent;
962 			}
963 			TMPFS_UNLOCK(tmp);
964 			if (n == NULL) {
965 				error = EINVAL;
966 				if (newname != NULL)
967 					    free(newname, M_TMPFSNAME);
968 				goto out_locked;
969 			}
970 			TMPFS_NODE_UNLOCK(n);
971 
972 			/* Adjust the parent pointer. */
973 			TMPFS_VALIDATE_DIR(fnode);
974 			TMPFS_NODE_LOCK(de->td_node);
975 			de->td_node->tn_dir.tn_parent = tdnode;
976 			TMPFS_NODE_UNLOCK(de->td_node);
977 
978 			/* As a result of changing the target of the '..'
979 			 * entry, the link count of the source and target
980 			 * directories has to be adjusted. */
981 			TMPFS_NODE_LOCK(tdnode);
982 			TMPFS_ASSERT_LOCKED(tdnode);
983 			tdnode->tn_links++;
984 			TMPFS_NODE_UNLOCK(tdnode);
985 
986 			TMPFS_NODE_LOCK(fdnode);
987 			TMPFS_ASSERT_LOCKED(fdnode);
988 			fdnode->tn_links--;
989 			TMPFS_NODE_UNLOCK(fdnode);
990 		}
991 	}
992 
993 	/* Do the move: just remove the entry from the source directory
994 	 * and insert it into the target one. */
995 	tmpfs_dir_detach(fdvp, de);
996 
997 	if (fcnp->cn_flags & DOWHITEOUT)
998 		tmpfs_dir_whiteout_add(fdvp, fcnp);
999 	if (tcnp->cn_flags & ISWHITEOUT)
1000 		tmpfs_dir_whiteout_remove(tdvp, tcnp);
1001 
1002 	/* If the name has changed, we need to make it effective by changing
1003 	 * it in the directory entry. */
1004 	if (newname != NULL) {
1005 		MPASS(tcnp->cn_namelen <= MAXNAMLEN);
1006 
1007 		free(de->ud.td_name, M_TMPFSNAME);
1008 		de->ud.td_name = newname;
1009 		tmpfs_dirent_init(de, tcnp->cn_nameptr, tcnp->cn_namelen);
1010 
1011 		fnode->tn_status |= TMPFS_NODE_CHANGED;
1012 		tdnode->tn_status |= TMPFS_NODE_MODIFIED;
1013 	}
1014 
1015 	/* If we are overwriting an entry, we have to remove the old one
1016 	 * from the target directory. */
1017 	if (tvp != NULL) {
1018 		struct tmpfs_dirent *tde;
1019 
1020 		/* Remove the old entry from the target directory. */
1021 		tde = tmpfs_dir_lookup(tdnode, tnode, tcnp);
1022 		tmpfs_dir_detach(tdvp, tde);
1023 
1024 		/* Free the directory entry we just deleted.  Note that the
1025 		 * node referred by it will not be removed until the vnode is
1026 		 * really reclaimed. */
1027 		tmpfs_free_dirent(VFS_TO_TMPFS(tvp->v_mount), tde);
1028 	}
1029 
1030 	tmpfs_dir_attach(tdvp, de);
1031 
1032 	if (tmpfs_use_nc(fvp)) {
1033 		cache_purge(fvp);
1034 		if (tvp != NULL)
1035 			cache_purge(tvp);
1036 		cache_purge_negative(tdvp);
1037 	}
1038 
1039 	error = 0;
1040 
1041 out_locked:
1042 	if (fdvp != tdvp && fdvp != tvp)
1043 		VOP_UNLOCK(fdvp, 0);
1044 
1045 out:
1046 	/* Release target nodes. */
1047 	/* XXX: I don't understand when tdvp can be the same as tvp, but
1048 	 * other code takes care of this... */
1049 	if (tdvp == tvp)
1050 		vrele(tdvp);
1051 	else
1052 		vput(tdvp);
1053 	if (tvp != NULL)
1054 		vput(tvp);
1055 
1056 	/* Release source nodes. */
1057 	vrele(fdvp);
1058 	vrele(fvp);
1059 
1060 	if (mp != NULL)
1061 		vfs_unbusy(mp);
1062 
1063 	return error;
1064 }
1065 
1066 static int
1067 tmpfs_mkdir(struct vop_mkdir_args *v)
1068 {
1069 	struct vnode *dvp = v->a_dvp;
1070 	struct vnode **vpp = v->a_vpp;
1071 	struct componentname *cnp = v->a_cnp;
1072 	struct vattr *vap = v->a_vap;
1073 
1074 	MPASS(vap->va_type == VDIR);
1075 
1076 	return tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
1077 }
1078 
1079 static int
1080 tmpfs_rmdir(struct vop_rmdir_args *v)
1081 {
1082 	struct vnode *dvp = v->a_dvp;
1083 	struct vnode *vp = v->a_vp;
1084 
1085 	int error;
1086 	struct tmpfs_dirent *de;
1087 	struct tmpfs_mount *tmp;
1088 	struct tmpfs_node *dnode;
1089 	struct tmpfs_node *node;
1090 
1091 	MPASS(VOP_ISLOCKED(dvp));
1092 	MPASS(VOP_ISLOCKED(vp));
1093 
1094 	tmp = VFS_TO_TMPFS(dvp->v_mount);
1095 	dnode = VP_TO_TMPFS_DIR(dvp);
1096 	node = VP_TO_TMPFS_DIR(vp);
1097 
1098 	/* Directories with more than two entries ('.' and '..') cannot be
1099 	 * removed. */
1100 	 if (node->tn_size > 0) {
1101 		 error = ENOTEMPTY;
1102 		 goto out;
1103 	 }
1104 
1105 	if ((dnode->tn_flags & APPEND)
1106 	    || (node->tn_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
1107 		error = EPERM;
1108 		goto out;
1109 	}
1110 
1111 	/* This invariant holds only if we are not trying to remove "..".
1112 	  * We checked for that above so this is safe now. */
1113 	MPASS(node->tn_dir.tn_parent == dnode);
1114 
1115 	/* Get the directory entry associated with node (vp).  This was
1116 	 * filled by tmpfs_lookup while looking up the entry. */
1117 	de = tmpfs_dir_lookup(dnode, node, v->a_cnp);
1118 	MPASS(TMPFS_DIRENT_MATCHES(de,
1119 	    v->a_cnp->cn_nameptr,
1120 	    v->a_cnp->cn_namelen));
1121 
1122 	/* Check flags to see if we are allowed to remove the directory. */
1123 	if ((dnode->tn_flags & APPEND) != 0 ||
1124 	    (node->tn_flags & (NOUNLINK | IMMUTABLE | APPEND)) != 0) {
1125 		error = EPERM;
1126 		goto out;
1127 	}
1128 
1129 
1130 	/* Detach the directory entry from the directory (dnode). */
1131 	tmpfs_dir_detach(dvp, de);
1132 	if (v->a_cnp->cn_flags & DOWHITEOUT)
1133 		tmpfs_dir_whiteout_add(dvp, v->a_cnp);
1134 
1135 	/* No vnode should be allocated for this entry from this point */
1136 	TMPFS_NODE_LOCK(node);
1137 	node->tn_links--;
1138 	node->tn_dir.tn_parent = NULL;
1139 	node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
1140 	    TMPFS_NODE_MODIFIED;
1141 
1142 	TMPFS_NODE_UNLOCK(node);
1143 
1144 	TMPFS_NODE_LOCK(dnode);
1145 	dnode->tn_links--;
1146 	dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
1147 	    TMPFS_NODE_MODIFIED;
1148 	TMPFS_NODE_UNLOCK(dnode);
1149 
1150 	if (tmpfs_use_nc(dvp)) {
1151 		cache_purge(dvp);
1152 		cache_purge(vp);
1153 	}
1154 
1155 	/* Free the directory entry we just deleted.  Note that the node
1156 	 * referred by it will not be removed until the vnode is really
1157 	 * reclaimed. */
1158 	tmpfs_free_dirent(tmp, de);
1159 
1160 	/* Release the deleted vnode (will destroy the node, notify
1161 	 * interested parties and clean it from the cache). */
1162 
1163 	dnode->tn_status |= TMPFS_NODE_CHANGED;
1164 	tmpfs_update(dvp);
1165 
1166 	error = 0;
1167 
1168 out:
1169 	return error;
1170 }
1171 
1172 static int
1173 tmpfs_symlink(struct vop_symlink_args *v)
1174 {
1175 	struct vnode *dvp = v->a_dvp;
1176 	struct vnode **vpp = v->a_vpp;
1177 	struct componentname *cnp = v->a_cnp;
1178 	struct vattr *vap = v->a_vap;
1179 	char *target = v->a_target;
1180 
1181 #ifdef notyet /* XXX FreeBSD BUG: kern_symlink is not setting VLNK */
1182 	MPASS(vap->va_type == VLNK);
1183 #else
1184 	vap->va_type = VLNK;
1185 #endif
1186 
1187 	return tmpfs_alloc_file(dvp, vpp, vap, cnp, target);
1188 }
1189 
1190 static int
1191 tmpfs_readdir(struct vop_readdir_args *v)
1192 {
1193 	struct vnode *vp = v->a_vp;
1194 	struct uio *uio = v->a_uio;
1195 	int *eofflag = v->a_eofflag;
1196 	u_long **cookies = v->a_cookies;
1197 	int *ncookies = v->a_ncookies;
1198 
1199 	int error;
1200 	ssize_t startresid;
1201 	int maxcookies;
1202 	struct tmpfs_node *node;
1203 
1204 	/* This operation only makes sense on directory nodes. */
1205 	if (vp->v_type != VDIR)
1206 		return ENOTDIR;
1207 
1208 	maxcookies = 0;
1209 	node = VP_TO_TMPFS_DIR(vp);
1210 
1211 	startresid = uio->uio_resid;
1212 
1213 	/* Allocate cookies for NFS and compat modules. */
1214 	if (cookies != NULL && ncookies != NULL) {
1215 		maxcookies = howmany(node->tn_size,
1216 		    sizeof(struct tmpfs_dirent)) + 2;
1217 		*cookies = malloc(maxcookies * sizeof(**cookies), M_TEMP,
1218 		    M_WAITOK);
1219 		*ncookies = 0;
1220 	}
1221 
1222 	if (cookies == NULL)
1223 		error = tmpfs_dir_getdents(node, uio, 0, NULL, NULL);
1224 	else
1225 		error = tmpfs_dir_getdents(node, uio, maxcookies, *cookies,
1226 		    ncookies);
1227 
1228 	/* Buffer was filled without hitting EOF. */
1229 	if (error == EJUSTRETURN)
1230 		error = (uio->uio_resid != startresid) ? 0 : EINVAL;
1231 
1232 	if (error != 0 && cookies != NULL && ncookies != NULL) {
1233 		free(*cookies, M_TEMP);
1234 		*cookies = NULL;
1235 		*ncookies = 0;
1236 	}
1237 
1238 	if (eofflag != NULL)
1239 		*eofflag =
1240 		    (error == 0 && uio->uio_offset == TMPFS_DIRCOOKIE_EOF);
1241 
1242 	return error;
1243 }
1244 
1245 static int
1246 tmpfs_readlink(struct vop_readlink_args *v)
1247 {
1248 	struct vnode *vp = v->a_vp;
1249 	struct uio *uio = v->a_uio;
1250 
1251 	int error;
1252 	struct tmpfs_node *node;
1253 
1254 	MPASS(uio->uio_offset == 0);
1255 	MPASS(vp->v_type == VLNK);
1256 
1257 	node = VP_TO_TMPFS_NODE(vp);
1258 
1259 	error = uiomove(node->tn_link, MIN(node->tn_size, uio->uio_resid),
1260 	    uio);
1261 	tmpfs_set_status(node, TMPFS_NODE_ACCESSED);
1262 
1263 	return (error);
1264 }
1265 
1266 static int
1267 tmpfs_inactive(struct vop_inactive_args *v)
1268 {
1269 	struct vnode *vp;
1270 	struct tmpfs_node *node;
1271 
1272 	vp = v->a_vp;
1273 	node = VP_TO_TMPFS_NODE(vp);
1274 	if (node->tn_links == 0)
1275 		vrecycle(vp);
1276 	else
1277 		tmpfs_check_mtime(vp);
1278 	return (0);
1279 }
1280 
1281 int
1282 tmpfs_reclaim(struct vop_reclaim_args *v)
1283 {
1284 	struct vnode *vp = v->a_vp;
1285 
1286 	struct tmpfs_mount *tmp;
1287 	struct tmpfs_node *node;
1288 
1289 	node = VP_TO_TMPFS_NODE(vp);
1290 	tmp = VFS_TO_TMPFS(vp->v_mount);
1291 
1292 	if (vp->v_type == VREG)
1293 		tmpfs_destroy_vobject(vp, node->tn_reg.tn_aobj);
1294 	else
1295 		vnode_destroy_vobject(vp);
1296 	vp->v_object = NULL;
1297 	if (tmpfs_use_nc(vp))
1298 		cache_purge(vp);
1299 
1300 	TMPFS_NODE_LOCK(node);
1301 	tmpfs_free_vp(vp);
1302 
1303 	/* If the node referenced by this vnode was deleted by the user,
1304 	 * we must free its associated data structures (now that the vnode
1305 	 * is being reclaimed). */
1306 	if (node->tn_links == 0 &&
1307 	    (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0) {
1308 		node->tn_vpstate = TMPFS_VNODE_DOOMED;
1309 		TMPFS_NODE_UNLOCK(node);
1310 		tmpfs_free_node(tmp, node);
1311 	} else
1312 		TMPFS_NODE_UNLOCK(node);
1313 
1314 	MPASS(vp->v_data == NULL);
1315 	return 0;
1316 }
1317 
1318 int
1319 tmpfs_print(struct vop_print_args *v)
1320 {
1321 	struct vnode *vp = v->a_vp;
1322 
1323 	struct tmpfs_node *node;
1324 
1325 	node = VP_TO_TMPFS_NODE(vp);
1326 
1327 	printf("tag VT_TMPFS, tmpfs_node %p, flags 0x%lx, links %jd\n",
1328 	    node, node->tn_flags, (uintmax_t)node->tn_links);
1329 	printf("\tmode 0%o, owner %d, group %d, size %jd, status 0x%x\n",
1330 	    node->tn_mode, node->tn_uid, node->tn_gid,
1331 	    (intmax_t)node->tn_size, node->tn_status);
1332 
1333 	if (vp->v_type == VFIFO)
1334 		fifo_printinfo(vp);
1335 
1336 	printf("\n");
1337 
1338 	return 0;
1339 }
1340 
1341 int
1342 tmpfs_pathconf(struct vop_pathconf_args *v)
1343 {
1344 	struct vnode *vp = v->a_vp;
1345 	int name = v->a_name;
1346 	long *retval = v->a_retval;
1347 
1348 	int error;
1349 
1350 	error = 0;
1351 
1352 	switch (name) {
1353 	case _PC_LINK_MAX:
1354 		*retval = TMPFS_LINK_MAX;
1355 		break;
1356 
1357 	case _PC_NAME_MAX:
1358 		*retval = NAME_MAX;
1359 		break;
1360 
1361 	case _PC_PIPE_BUF:
1362 		if (vp->v_type == VDIR || vp->v_type == VFIFO)
1363 			*retval = PIPE_BUF;
1364 		else
1365 			error = EINVAL;
1366 		break;
1367 
1368 	case _PC_CHOWN_RESTRICTED:
1369 		*retval = 1;
1370 		break;
1371 
1372 	case _PC_NO_TRUNC:
1373 		*retval = 1;
1374 		break;
1375 
1376 	case _PC_SYNC_IO:
1377 		*retval = 1;
1378 		break;
1379 
1380 	case _PC_FILESIZEBITS:
1381 		*retval = 64;
1382 		break;
1383 
1384 	default:
1385 		error = vop_stdpathconf(v);
1386 	}
1387 
1388 	return error;
1389 }
1390 
1391 static int
1392 tmpfs_vptofh(struct vop_vptofh_args *ap)
1393 {
1394 	struct tmpfs_fid *tfhp;
1395 	struct tmpfs_node *node;
1396 
1397 	tfhp = (struct tmpfs_fid *)ap->a_fhp;
1398 	node = VP_TO_TMPFS_NODE(ap->a_vp);
1399 
1400 	tfhp->tf_len = sizeof(struct tmpfs_fid);
1401 	tfhp->tf_id = node->tn_id;
1402 	tfhp->tf_gen = node->tn_gen;
1403 
1404 	return (0);
1405 }
1406 
1407 static int
1408 tmpfs_whiteout(struct vop_whiteout_args *ap)
1409 {
1410 	struct vnode *dvp = ap->a_dvp;
1411 	struct componentname *cnp = ap->a_cnp;
1412 	struct tmpfs_dirent *de;
1413 
1414 	switch (ap->a_flags) {
1415 	case LOOKUP:
1416 		return (0);
1417 	case CREATE:
1418 		de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp);
1419 		if (de != NULL)
1420 			return (de->td_node == NULL ? 0 : EEXIST);
1421 		return (tmpfs_dir_whiteout_add(dvp, cnp));
1422 	case DELETE:
1423 		tmpfs_dir_whiteout_remove(dvp, cnp);
1424 		return (0);
1425 	default:
1426 		panic("tmpfs_whiteout: unknown op");
1427 	}
1428 }
1429 
1430 static int
1431 tmpfs_vptocnp_dir(struct tmpfs_node *tn, struct tmpfs_node *tnp,
1432     struct tmpfs_dirent **pde)
1433 {
1434 	struct tmpfs_dir_cursor dc;
1435 	struct tmpfs_dirent *de;
1436 
1437 	for (de = tmpfs_dir_first(tnp, &dc); de != NULL;
1438 	     de = tmpfs_dir_next(tnp, &dc)) {
1439 		if (de->td_node == tn) {
1440 			*pde = de;
1441 			return (0);
1442 		}
1443 	}
1444 	return (ENOENT);
1445 }
1446 
1447 static int
1448 tmpfs_vptocnp_fill(struct vnode *vp, struct tmpfs_node *tn,
1449     struct tmpfs_node *tnp, char *buf, int *buflen, struct vnode **dvp)
1450 {
1451 	struct tmpfs_dirent *de;
1452 	int error, i;
1453 
1454 	error = vn_vget_ino_gen(vp, tmpfs_vn_get_ino_alloc, tnp, LK_SHARED,
1455 	    dvp);
1456 	if (error != 0)
1457 		return (error);
1458 	error = tmpfs_vptocnp_dir(tn, tnp, &de);
1459 	if (error == 0) {
1460 		i = *buflen;
1461 		i -= de->td_namelen;
1462 		if (i < 0) {
1463 			error = ENOMEM;
1464 		} else {
1465 			bcopy(de->ud.td_name, buf + i, de->td_namelen);
1466 			*buflen = i;
1467 		}
1468 	}
1469 	if (error == 0) {
1470 		if (vp != *dvp)
1471 			VOP_UNLOCK(*dvp, 0);
1472 	} else {
1473 		if (vp != *dvp)
1474 			vput(*dvp);
1475 		else
1476 			vrele(vp);
1477 	}
1478 	return (error);
1479 }
1480 
1481 static int
1482 tmpfs_vptocnp(struct vop_vptocnp_args *ap)
1483 {
1484 	struct vnode *vp, **dvp;
1485 	struct tmpfs_node *tn, *tnp, *tnp1;
1486 	struct tmpfs_dirent *de;
1487 	struct tmpfs_mount *tm;
1488 	char *buf;
1489 	int *buflen;
1490 	int error;
1491 
1492 	vp = ap->a_vp;
1493 	dvp = ap->a_vpp;
1494 	buf = ap->a_buf;
1495 	buflen = ap->a_buflen;
1496 
1497 	tm = VFS_TO_TMPFS(vp->v_mount);
1498 	tn = VP_TO_TMPFS_NODE(vp);
1499 	if (tn->tn_type == VDIR) {
1500 		tnp = tn->tn_dir.tn_parent;
1501 		if (tnp == NULL)
1502 			return (ENOENT);
1503 		tmpfs_ref_node(tnp);
1504 		error = tmpfs_vptocnp_fill(vp, tn, tn->tn_dir.tn_parent, buf,
1505 		    buflen, dvp);
1506 		tmpfs_free_node(tm, tnp);
1507 		return (error);
1508 	}
1509 restart:
1510 	TMPFS_LOCK(tm);
1511 	LIST_FOREACH_SAFE(tnp, &tm->tm_nodes_used, tn_entries, tnp1) {
1512 		if (tnp->tn_type != VDIR)
1513 			continue;
1514 		TMPFS_NODE_LOCK(tnp);
1515 		tmpfs_ref_node_locked(tnp);
1516 
1517 		/*
1518 		 * tn_vnode cannot be instantiated while we hold the
1519 		 * node lock, so the directory cannot be changed while
1520 		 * we iterate over it.  Do this to avoid instantiating
1521 		 * vnode for directories which cannot point to our
1522 		 * node.
1523 		 */
1524 		error = tnp->tn_vnode == NULL ? tmpfs_vptocnp_dir(tn, tnp,
1525 		    &de) : 0;
1526 
1527 		if (error == 0) {
1528 			TMPFS_NODE_UNLOCK(tnp);
1529 			TMPFS_UNLOCK(tm);
1530 			error = tmpfs_vptocnp_fill(vp, tn, tnp, buf, buflen,
1531 			    dvp);
1532 			if (error == 0) {
1533 				tmpfs_free_node(tm, tnp);
1534 				return (0);
1535 			}
1536 			if ((vp->v_iflag & VI_DOOMED) != 0) {
1537 				tmpfs_free_node(tm, tnp);
1538 				return (ENOENT);
1539 			}
1540 			TMPFS_LOCK(tm);
1541 			TMPFS_NODE_LOCK(tnp);
1542 		}
1543 		if (tmpfs_free_node_locked(tm, tnp, false)) {
1544 			goto restart;
1545 		} else {
1546 			KASSERT(tnp->tn_refcount > 0,
1547 			    ("node %p refcount zero", tnp));
1548 			tnp1 = LIST_NEXT(tnp, tn_entries);
1549 			TMPFS_NODE_UNLOCK(tnp);
1550 		}
1551 	}
1552 	TMPFS_UNLOCK(tm);
1553 	return (ENOENT);
1554 }
1555 
1556 /*
1557  * Vnode operations vector used for files stored in a tmpfs file system.
1558  */
1559 struct vop_vector tmpfs_vnodeop_entries = {
1560 	.vop_default =			&default_vnodeops,
1561 	.vop_lookup =			vfs_cache_lookup,
1562 	.vop_cachedlookup =		tmpfs_cached_lookup,
1563 	.vop_create =			tmpfs_create,
1564 	.vop_mknod =			tmpfs_mknod,
1565 	.vop_open =			tmpfs_open,
1566 	.vop_close =			tmpfs_close,
1567 	.vop_access =			tmpfs_access,
1568 	.vop_getattr =			tmpfs_getattr,
1569 	.vop_setattr =			tmpfs_setattr,
1570 	.vop_read =			tmpfs_read,
1571 	.vop_write =			tmpfs_write,
1572 	.vop_fsync =			tmpfs_fsync,
1573 	.vop_remove =			tmpfs_remove,
1574 	.vop_link =			tmpfs_link,
1575 	.vop_rename =			tmpfs_rename,
1576 	.vop_mkdir =			tmpfs_mkdir,
1577 	.vop_rmdir =			tmpfs_rmdir,
1578 	.vop_symlink =			tmpfs_symlink,
1579 	.vop_readdir =			tmpfs_readdir,
1580 	.vop_readlink =			tmpfs_readlink,
1581 	.vop_inactive =			tmpfs_inactive,
1582 	.vop_reclaim =			tmpfs_reclaim,
1583 	.vop_print =			tmpfs_print,
1584 	.vop_pathconf =			tmpfs_pathconf,
1585 	.vop_vptofh =			tmpfs_vptofh,
1586 	.vop_whiteout =			tmpfs_whiteout,
1587 	.vop_bmap =			VOP_EOPNOTSUPP,
1588 	.vop_vptocnp =			tmpfs_vptocnp,
1589 };
1590 
1591 /*
1592  * Same vector for mounts which do not use namecache.
1593  */
1594 struct vop_vector tmpfs_vnodeop_nonc_entries = {
1595 	.vop_default =			&tmpfs_vnodeop_entries,
1596 	.vop_lookup =			tmpfs_lookup,
1597 };
1598