xref: /dragonfly/sys/vfs/tmpfs/tmpfs_subr.c (revision de78d61c)
1 /*	$NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2005 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  * Efficient memory file system supporting functions.
35  */
36 
37 #include <sys/kernel.h>
38 #include <sys/param.h>
39 #include <sys/namei.h>
40 #include <sys/priv.h>
41 #include <sys/proc.h>
42 #include <sys/stat.h>
43 #include <sys/systm.h>
44 #include <sys/vnode.h>
45 #include <sys/vmmeter.h>
46 
47 #include <vm/vm.h>
48 #include <vm/vm_object.h>
49 #include <vm/vm_page.h>
50 #include <vm/vm_pager.h>
51 #include <vm/vm_extern.h>
52 
53 #include <vfs/tmpfs/tmpfs.h>
54 #include <vfs/tmpfs/tmpfs_vnops.h>
55 
56 static ino_t tmpfs_fetch_ino(struct tmpfs_mount *);
57 
58 static int tmpfs_dirtree_compare(struct tmpfs_dirent *a,
59 	struct tmpfs_dirent *b);
60 RB_GENERATE(tmpfs_dirtree, tmpfs_dirent, rb_node, tmpfs_dirtree_compare);
61 
62 static int tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a,
63 	struct tmpfs_dirent *b);
64 RB_GENERATE(tmpfs_dirtree_cookie, tmpfs_dirent,
65 	rb_cookienode, tmpfs_dirtree_compare_cookie);
66 
67 
68 /* --------------------------------------------------------------------- */
69 
70 /*
71  * Allocates a new node of type 'type' inside the 'tmp' mount point, with
72  * its owner set to 'uid', its group to 'gid' and its mode set to 'mode',
73  * using the credentials of the process 'p'.
74  *
75  * If the node type is set to 'VDIR', then the parent parameter must point
76  * to the parent directory of the node being created.  It may only be NULL
77  * while allocating the root node.
78  *
79  * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter
80  * specifies the device the node represents.
81  *
82  * If the node type is set to 'VLNK', then the parameter target specifies
83  * the file name of the target file for the symbolic link that is being
84  * created.
85  *
86  * Note that new nodes are retrieved from the available list if it has
87  * items or, if it is empty, from the node pool as long as there is enough
88  * space to create them.
89  *
90  * Returns zero on success or an appropriate error code on failure.
91  */
92 int
93 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type,
94 		 uid_t uid, gid_t gid, mode_t mode,
95 		 char *target, int rmajor, int rminor,
96 		 struct tmpfs_node **node)
97 {
98 	struct tmpfs_node *nnode;
99 	struct timespec ts;
100 	udev_t rdev;
101 
102 	KKASSERT(IFF(type == VLNK, target != NULL));
103 	KKASSERT(IFF(type == VBLK || type == VCHR, rmajor != VNOVAL));
104 
105 	if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max)
106 		return (ENOSPC);
107 
108 	nnode = objcache_get(tmp->tm_node_pool, M_WAITOK | M_NULLOK);
109 	if (nnode == NULL)
110 		return (ENOSPC);
111 
112 	/* Generic initialization. */
113 	nnode->tn_type = type;
114 	vfs_timestamp(&ts);
115 	nnode->tn_ctime = nnode->tn_mtime = nnode->tn_atime
116 		= ts.tv_sec;
117 	nnode->tn_ctimensec = nnode->tn_mtimensec = nnode->tn_atimensec
118 		= ts.tv_nsec;
119 	nnode->tn_uid = uid;
120 	nnode->tn_gid = gid;
121 	nnode->tn_mode = mode;
122 	nnode->tn_id = tmpfs_fetch_ino(tmp);
123 	nnode->tn_advlock.init_done = 0;
124 	KKASSERT(nnode->tn_links == 0);
125 
126 	/* Type-specific initialization. */
127 	switch (nnode->tn_type) {
128 	case VBLK:
129 	case VCHR:
130 		rdev = makeudev(rmajor, rminor);
131 		if (rdev == NOUDEV) {
132 			objcache_put(tmp->tm_node_pool, nnode);
133 			return(EINVAL);
134 		}
135 		nnode->tn_rdev = rdev;
136 		break;
137 
138 	case VDIR:
139 		RB_INIT(&nnode->tn_dir.tn_dirtree);
140 		RB_INIT(&nnode->tn_dir.tn_cookietree);
141 		nnode->tn_size = 0;
142 		break;
143 
144 	case VFIFO:
145 		/* FALLTHROUGH */
146 	case VSOCK:
147 		break;
148 
149 	case VLNK:
150 		nnode->tn_size = strlen(target);
151 		nnode->tn_link = kmalloc(nnode->tn_size + 1, tmp->tm_name_zone,
152 					 M_WAITOK | M_NULLOK);
153 		if (nnode->tn_link == NULL) {
154 			objcache_put(tmp->tm_node_pool, nnode);
155 			return (ENOSPC);
156 		}
157 		bcopy(target, nnode->tn_link, nnode->tn_size);
158 		nnode->tn_link[nnode->tn_size] = '\0';
159 		break;
160 
161 	case VREG:
162 		nnode->tn_reg.tn_aobj = swap_pager_alloc(NULL, 0,
163 							 VM_PROT_DEFAULT, 0);
164 		nnode->tn_reg.tn_aobj_pages = 0;
165 		nnode->tn_size = 0;
166 		vm_object_set_flag(nnode->tn_reg.tn_aobj, OBJ_NOPAGEIN);
167 		break;
168 
169 	default:
170 		panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type);
171 	}
172 
173 	TMPFS_NODE_LOCK(nnode);
174 	TMPFS_LOCK(tmp);
175 	LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries);
176 	tmp->tm_nodes_inuse++;
177 	TMPFS_UNLOCK(tmp);
178 	TMPFS_NODE_UNLOCK(nnode);
179 
180 	*node = nnode;
181 	return 0;
182 }
183 
184 /* --------------------------------------------------------------------- */
185 
186 /*
187  * Destroys the node pointed to by node from the file system 'tmp'.
188  * If the node does not belong to the given mount point, the results are
189  * unpredicted.
190  *
191  * If the node references a directory; no entries are allowed because
192  * their removal could need a recursive algorithm, something forbidden in
193  * kernel space.  Furthermore, there is not need to provide such
194  * functionality (recursive removal) because the only primitives offered
195  * to the user are the removal of empty directories and the deletion of
196  * individual files.
197  *
198  * Note that nodes are not really deleted; in fact, when a node has been
199  * allocated, it cannot be deleted during the whole life of the file
200  * system.  Instead, they are moved to the available list and remain there
201  * until reused.
202  *
203  * A caller must have TMPFS_NODE_LOCK(node) and this function unlocks it.
204  */
205 void
206 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node)
207 {
208 	vm_pindex_t pages = 0;
209 
210 #ifdef INVARIANTS
211 	TMPFS_ASSERT_ELOCKED(node);
212 	KKASSERT(node->tn_vnode == NULL);
213 	KKASSERT((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0);
214 #endif
215 
216 	TMPFS_LOCK(tmp);
217 	LIST_REMOVE(node, tn_entries);
218 	tmp->tm_nodes_inuse--;
219 	TMPFS_UNLOCK(tmp);
220 	TMPFS_NODE_UNLOCK(node);  /* Caller has this lock */
221 
222 	switch (node->tn_type) {
223 	case VNON:
224 		/* Do not do anything.  VNON is provided to let the
225 		 * allocation routine clean itself easily by avoiding
226 		 * duplicating code in it. */
227 		/* FALLTHROUGH */
228 	case VBLK:
229 		/* FALLTHROUGH */
230 	case VCHR:
231 		/* FALLTHROUGH */
232 		break;
233 	case VDIR:
234 		/*
235 		 * The parent link can be NULL if this is the root
236 		 * node or if it is a directory node that was rmdir'd.
237 		 *
238 		 * XXX what if node is a directory which still contains
239 		 * directory entries (e.g. due to a forced umount) ?
240 		 */
241 		node->tn_size = 0;
242 		KKASSERT(node->tn_dir.tn_parent == NULL);
243 
244 		/*
245 		 * If the root node is being destroyed don't leave a
246 		 * dangling pointer in tmpfs_mount.
247 		 */
248 		if (node == tmp->tm_root)
249 			tmp->tm_root = NULL;
250 		break;
251 	case VFIFO:
252 		/* FALLTHROUGH */
253 	case VSOCK:
254 		break;
255 
256 	case VLNK:
257 		kfree(node->tn_link, tmp->tm_name_zone);
258 		node->tn_link = NULL;
259 		node->tn_size = 0;
260 		break;
261 
262 	case VREG:
263 		if (node->tn_reg.tn_aobj != NULL)
264 			vm_object_deallocate(node->tn_reg.tn_aobj);
265 		node->tn_reg.tn_aobj = NULL;
266 		pages = node->tn_reg.tn_aobj_pages;
267 		break;
268 
269 	default:
270 		panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type);
271 	}
272 
273 	/*
274 	 * Clean up fields for the next allocation.  The objcache only ctors
275 	 * new allocations.
276 	 */
277 	tmpfs_node_ctor(node, NULL, 0);
278 	objcache_put(tmp->tm_node_pool, node);
279 	/* node is now invalid */
280 
281 	if (pages)
282 		atomic_add_long(&tmp->tm_pages_used, -(long)pages);
283 }
284 
285 /* --------------------------------------------------------------------- */
286 
287 /*
288  * Allocates a new directory entry for the node node with a name of name.
289  * The new directory entry is returned in *de.
290  *
291  * The link count of node is increased by one to reflect the new object
292  * referencing it.
293  *
294  * Returns zero on success or an appropriate error code on failure.
295  */
296 int
297 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
298 		   const char *name, uint16_t len, struct tmpfs_dirent **de)
299 {
300 	struct tmpfs_dirent *nde;
301 
302 	nde = objcache_get(tmp->tm_dirent_pool, M_WAITOK);
303 	nde->td_name = kmalloc(len + 1, tmp->tm_name_zone, M_WAITOK | M_NULLOK);
304 	if (nde->td_name == NULL) {
305 		objcache_put(tmp->tm_dirent_pool, nde);
306 		*de = NULL;
307 		return (ENOSPC);
308 	}
309 	nde->td_namelen = len;
310 	bcopy(name, nde->td_name, len);
311 	nde->td_name[len] = '\0';
312 
313 	nde->td_node = node;
314 
315 	TMPFS_NODE_LOCK(node);
316 	++node->tn_links;
317 	TMPFS_NODE_UNLOCK(node);
318 
319 	*de = nde;
320 
321 	return 0;
322 }
323 
324 /* --------------------------------------------------------------------- */
325 
326 /*
327  * Frees a directory entry.  It is the caller's responsibility to destroy
328  * the node referenced by it if needed.
329  *
330  * The link count of node is decreased by one to reflect the removal of an
331  * object that referenced it.  This only happens if 'node_exists' is true;
332  * otherwise the function will not access the node referred to by the
333  * directory entry, as it may already have been released from the outside.
334  */
335 void
336 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de)
337 {
338 	struct tmpfs_node *node;
339 
340 	node = de->td_node;
341 
342 	TMPFS_NODE_LOCK(node);
343 	TMPFS_ASSERT_ELOCKED(node);
344 	KKASSERT(node->tn_links > 0);
345 	node->tn_links--;
346 	TMPFS_NODE_UNLOCK(node);
347 
348 	kfree(de->td_name, tmp->tm_name_zone);
349 	de->td_namelen = 0;
350 	de->td_name = NULL;
351 	de->td_node = NULL;
352 	objcache_put(tmp->tm_dirent_pool, de);
353 }
354 
355 /* --------------------------------------------------------------------- */
356 
357 /*
358  * Allocates a new vnode for the node node or returns a new reference to
359  * an existing one if the node had already a vnode referencing it.  The
360  * resulting locked vnode is returned in *vpp.
361  *
362  * Returns zero on success or an appropriate error code on failure.
363  *
364  * The caller must ensure that node cannot go away (usually by holding
365  * the related directory entry).
366  *
367  * If dnode is non-NULL this routine avoids deadlocking against it but
368  * can return EAGAIN.  Caller must try again.  The dnode lock will cycle
369  * in this case, it remains locked on return in all cases.  dnode must
370  * be shared-locked.
371  */
372 int
373 tmpfs_alloc_vp(struct mount *mp,
374 	       struct tmpfs_node *dnode, struct tmpfs_node *node, int lkflag,
375 	       struct vnode **vpp)
376 {
377 	int error = 0;
378 	struct vnode *vp;
379 
380 loop:
381 	/*
382 	 * Interlocked extraction from node.  This can race many things.
383 	 * We have to get a soft reference on the vnode while we hold
384 	 * the node locked, then acquire it properly and check for races.
385 	 */
386 	TMPFS_NODE_LOCK(node);
387 	if ((vp = node->tn_vnode) != NULL) {
388 		KKASSERT((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0);
389 		vhold(vp);
390 		TMPFS_NODE_UNLOCK(node);
391 
392 		if (dnode) {
393 			/*
394 			 * Special-case handling to avoid deadlocking against
395 			 * dnode.  This case has been validated and occurs
396 			 * every so often during synth builds.
397 			 */
398 			if (vget(vp, (lkflag & ~LK_RETRY) |
399 				     LK_NOWAIT |
400 				     LK_EXCLUSIVE) != 0) {
401 				TMPFS_NODE_UNLOCK(dnode);
402 				if (vget(vp, (lkflag & ~LK_RETRY) |
403 					     LK_SLEEPFAIL |
404 					     LK_EXCLUSIVE) == 0) {
405 					vn_unlock(vp);
406 				}
407 				vdrop(vp);
408 				TMPFS_NODE_LOCK_SH(dnode);
409 
410 				return EAGAIN;
411 			}
412 		} else {
413 			/*
414 			 * Normal path
415 			 */
416 			if (vget(vp, lkflag | LK_EXCLUSIVE) != 0) {
417 				vdrop(vp);
418 				goto loop;
419 			}
420 		}
421 		if (node->tn_vnode != vp) {
422 			vput(vp);
423 			vdrop(vp);
424 			goto loop;
425 		}
426 		vdrop(vp);
427 		goto out;
428 	}
429 	/* vp is NULL */
430 
431 	/*
432 	 * This should never happen.
433 	 */
434 	if (node->tn_vpstate & TMPFS_VNODE_DOOMED) {
435 		TMPFS_NODE_UNLOCK(node);
436 		error = ENOENT;
437 		goto out;
438 	}
439 
440 	/*
441 	 * Interlock against other calls to tmpfs_alloc_vp() trying to
442 	 * allocate and assign a vp to node.
443 	 */
444 	if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) {
445 		node->tn_vpstate |= TMPFS_VNODE_WANT;
446 		error = tsleep(&node->tn_vpstate, PINTERLOCKED | PCATCH,
447 			       "tmpfs_alloc_vp", 0);
448 		TMPFS_NODE_UNLOCK(node);
449 		if (error)
450 			return error;
451 		goto loop;
452 	}
453 	node->tn_vpstate |= TMPFS_VNODE_ALLOCATING;
454 	TMPFS_NODE_UNLOCK(node);
455 
456 	/*
457 	 * Allocate a new vnode (may block).  The ALLOCATING flag should
458 	 * prevent a race against someone else assigning node->tn_vnode.
459 	 */
460 	error = getnewvnode(VT_TMPFS, mp, &vp, VLKTIMEOUT, LK_CANRECURSE);
461 	if (error != 0)
462 		goto unlock;
463 
464 	KKASSERT(node->tn_vnode == NULL);
465 	KKASSERT(vp != NULL);
466 	vp->v_data = node;
467 	vp->v_type = node->tn_type;
468 
469 	/* Type-specific initialization. */
470 	switch (node->tn_type) {
471 	case VBLK:
472 		/* FALLTHROUGH */
473 	case VCHR:
474 		/* FALLTHROUGH */
475 	case VSOCK:
476 		break;
477 	case VREG:
478 		/*
479 		 * VMIO is mandatory.  Tmpfs also supports KVABIO
480 		 * for its tmpfs_strategy().
481 		 */
482 		vsetflags(vp, VKVABIO);
483 		vinitvmio(vp, node->tn_size, TMPFS_BLKSIZE, -1);
484 		break;
485 	case VLNK:
486 		break;
487 	case VFIFO:
488 		vp->v_ops = &mp->mnt_vn_fifo_ops;
489 		break;
490 	case VDIR:
491 		break;
492 
493 	default:
494 		panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type);
495 	}
496 
497 
498 unlock:
499 	TMPFS_NODE_LOCK(node);
500 
501 	KKASSERT(node->tn_vpstate & TMPFS_VNODE_ALLOCATING);
502 	node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING;
503 	node->tn_vnode = vp;
504 
505 	if (node->tn_vpstate & TMPFS_VNODE_WANT) {
506 		node->tn_vpstate &= ~TMPFS_VNODE_WANT;
507 		TMPFS_NODE_UNLOCK(node);
508 		wakeup(&node->tn_vpstate);
509 	} else {
510 		TMPFS_NODE_UNLOCK(node);
511 	}
512 
513 out:
514 	*vpp = vp;
515 	KKASSERT(IFF(error == 0, *vpp != NULL && vn_islocked(*vpp)));
516 
517 	return error;
518 }
519 
520 /* --------------------------------------------------------------------- */
521 
522 /*
523  * Destroys the association between the vnode vp and the node it
524  * references.
525  */
526 void
527 tmpfs_free_vp(struct vnode *vp)
528 {
529 	struct tmpfs_node *node;
530 
531 	node = VP_TO_TMPFS_NODE(vp);
532 
533 	TMPFS_NODE_LOCK(node);
534 	KKASSERT(lockinuse(TMPFS_NODE_MTX(node)));
535 	node->tn_vnode = NULL;
536 	vp->v_data = NULL;
537 	TMPFS_NODE_UNLOCK(node);
538 }
539 
540 /* --------------------------------------------------------------------- */
541 
542 /*
543  * Allocates a new file of type 'type' and adds it to the parent directory
544  * 'dvp'; this addition is done using the component name given in 'cnp'.
545  * The ownership of the new file is automatically assigned based on the
546  * credentials of the caller (through 'cnp'), the group is set based on
547  * the parent directory and the mode is determined from the 'vap' argument.
548  * If successful, *vpp holds a vnode to the newly created file and zero
549  * is returned.  Otherwise *vpp is NULL and the function returns an
550  * appropriate error code.
551  */
552 int
553 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap,
554 		 struct namecache *ncp, struct ucred *cred, char *target)
555 {
556 	int error;
557 	struct tmpfs_dirent *de;
558 	struct tmpfs_mount *tmp;
559 	struct tmpfs_node *dnode;
560 	struct tmpfs_node *node;
561 
562 	tmp = VFS_TO_TMPFS(dvp->v_mount);
563 	dnode = VP_TO_TMPFS_DIR(dvp);
564 	*vpp = NULL;
565 
566 	/*
567 	 * If the directory was removed but a process was CD'd into it,
568 	 * we do not allow any more file/dir creation within it.  Otherwise
569 	 * we will lose track of it.
570 	 */
571 	KKASSERT(dnode->tn_type == VDIR);
572 	if (dnode != tmp->tm_root && dnode->tn_dir.tn_parent == NULL)
573 		return ENOENT;
574 
575 	/*
576 	 * Make sure the link count does not overflow.
577 	 */
578 	if (vap->va_type == VDIR && dnode->tn_links >= LINK_MAX)
579 		return EMLINK;
580 
581 	/* Allocate a node that represents the new file. */
582 	error = tmpfs_alloc_node(tmp, vap->va_type, cred->cr_uid,
583 				 dnode->tn_gid, vap->va_mode, target,
584 				 vap->va_rmajor, vap->va_rminor, &node);
585 	if (error != 0)
586 		return error;
587 	TMPFS_NODE_LOCK(node);
588 
589 	/* Allocate a directory entry that points to the new file. */
590 	error = tmpfs_alloc_dirent(tmp, node, ncp->nc_name, ncp->nc_nlen, &de);
591 	if (error != 0) {
592 		tmpfs_free_node(tmp, node);
593 		/* eats node lock */
594 		return error;
595 	}
596 
597 	/* Allocate a vnode for the new file. */
598 	error = tmpfs_alloc_vp(dvp->v_mount, NULL, node, LK_EXCLUSIVE, vpp);
599 	if (error != 0) {
600 		tmpfs_free_dirent(tmp, de);
601 		tmpfs_free_node(tmp, node);
602 		/* eats node lock */
603 		return error;
604 	}
605 
606 	/*
607 	 * Now that all required items are allocated, we can proceed to
608 	 * insert the new node into the directory, an operation that
609 	 * cannot fail.
610 	 */
611 	tmpfs_dir_attach(dnode, de);
612 	TMPFS_NODE_UNLOCK(node);
613 
614 	return error;
615 }
616 
617 /* --------------------------------------------------------------------- */
618 
619 /*
620  * Attaches the directory entry de to the directory represented by dnode.
621  * Note that this does not change the link count of the node pointed by
622  * the directory entry, as this is done by tmpfs_alloc_dirent.
623  */
624 void
625 tmpfs_dir_attach(struct tmpfs_node *dnode, struct tmpfs_dirent *de)
626 {
627 	struct tmpfs_node *node = de->td_node;
628 
629 	TMPFS_NODE_LOCK(dnode);
630 	if (node && node->tn_type == VDIR) {
631 		TMPFS_NODE_LOCK(node);
632 		++node->tn_links;
633 		node->tn_status |= TMPFS_NODE_CHANGED;
634 		node->tn_dir.tn_parent = dnode;
635 		++dnode->tn_links;
636 		TMPFS_NODE_UNLOCK(node);
637 	}
638 	RB_INSERT(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de);
639 	RB_INSERT(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de);
640 	dnode->tn_size += sizeof(struct tmpfs_dirent);
641 	dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
642 			    TMPFS_NODE_MODIFIED;
643 	TMPFS_NODE_UNLOCK(dnode);
644 }
645 
646 /* --------------------------------------------------------------------- */
647 
648 /*
649  * Detaches the directory entry de from the directory represented by dnode.
650  * Note that this does not change the link count of the node pointed by
651  * the directory entry, as this is done by tmpfs_free_dirent.
652  */
653 void
654 tmpfs_dir_detach(struct tmpfs_node *dnode, struct tmpfs_dirent *de)
655 {
656 	struct tmpfs_node *node = de->td_node;
657 
658 	TMPFS_NODE_LOCK(dnode);
659 	RB_REMOVE(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de);
660 	RB_REMOVE(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de);
661 	dnode->tn_size -= sizeof(struct tmpfs_dirent);
662 	dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
663 			    TMPFS_NODE_MODIFIED;
664 	TMPFS_NODE_UNLOCK(dnode);
665 
666 	/*
667 	 * Clean out the tn_parent pointer immediately when removing a
668 	 * directory.
669 	 *
670 	 * Removal of the parent linkage also cleans out the extra tn_links
671 	 * count we had on both node and dnode.
672 	 *
673 	 * node can be NULL (typ during a forced umount), in which case
674 	 * the mount code is dealing with the linkages from a linked list
675 	 * scan.
676 	 */
677 	if (node && node->tn_type == VDIR && node->tn_dir.tn_parent) {
678 		TMPFS_NODE_LOCK(dnode);
679 		TMPFS_NODE_LOCK(node);
680 		KKASSERT(node->tn_dir.tn_parent == dnode);
681 		dnode->tn_links--;
682 		node->tn_links--;
683 		node->tn_dir.tn_parent = NULL;
684 		TMPFS_NODE_UNLOCK(node);
685 		TMPFS_NODE_UNLOCK(dnode);
686 	}
687 }
688 
689 /* --------------------------------------------------------------------- */
690 
691 /*
692  * Looks for a directory entry in the directory represented by node.
693  * 'ncp' describes the name of the entry to look for.  Note that the .
694  * and .. components are not allowed as they do not physically exist
695  * within directories.
696  *
697  * Returns a pointer to the entry when found, otherwise NULL.
698  *
699  * Caller must hold the node locked (shared ok)
700  */
701 struct tmpfs_dirent *
702 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f,
703 		 struct namecache *ncp)
704 {
705 	struct tmpfs_dirent *de;
706 	int len = ncp->nc_nlen;
707 	struct tmpfs_dirent wanted;
708 
709 	wanted.td_namelen = len;
710 	wanted.td_name = ncp->nc_name;
711 
712 	TMPFS_VALIDATE_DIR(node);
713 
714 	de = RB_FIND(tmpfs_dirtree, &node->tn_dir.tn_dirtree, &wanted);
715 
716 	KKASSERT(f == NULL || f == de->td_node);
717 
718 	return de;
719 }
720 
721 /* --------------------------------------------------------------------- */
722 
723 /*
724  * Helper function for tmpfs_readdir.  Creates a '.' entry for the given
725  * directory and returns it in the uio space.  The function returns 0
726  * on success, -1 if there was not enough space in the uio structure to
727  * hold the directory entry or an appropriate error code if another
728  * error happens.
729  */
730 int
731 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio)
732 {
733 	int error;
734 
735 	TMPFS_VALIDATE_DIR(node);
736 	KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOT);
737 
738 	if (vop_write_dirent(&error, uio, node->tn_id, DT_DIR, 1, "."))
739 		return -1;
740 	if (error == 0)
741 		uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT;
742 	return error;
743 }
744 
745 /* --------------------------------------------------------------------- */
746 
747 /*
748  * Helper function for tmpfs_readdir.  Creates a '..' entry for the given
749  * directory and returns it in the uio space.  The function returns 0
750  * on success, -1 if there was not enough space in the uio structure to
751  * hold the directory entry or an appropriate error code if another
752  * error happens.
753  */
754 int
755 tmpfs_dir_getdotdotdent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
756 			struct uio *uio)
757 {
758 	int error;
759 	ino_t d_ino;
760 
761 	TMPFS_VALIDATE_DIR(node);
762 	KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
763 
764 	if (node->tn_dir.tn_parent) {
765 		TMPFS_NODE_LOCK(node);
766 		if (node->tn_dir.tn_parent)
767 			d_ino = node->tn_dir.tn_parent->tn_id;
768 		else
769 			d_ino = tmp->tm_root->tn_id;
770 		TMPFS_NODE_UNLOCK(node);
771 	} else {
772 		d_ino = tmp->tm_root->tn_id;
773 	}
774 
775 	if (vop_write_dirent(&error, uio, d_ino, DT_DIR, 2, ".."))
776 		return -1;
777 	if (error == 0) {
778 		struct tmpfs_dirent *de;
779 		de = RB_MIN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree);
780 		if (de == NULL)
781 			uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
782 		else
783 			uio->uio_offset = tmpfs_dircookie(de);
784 	}
785 	return error;
786 }
787 
788 /* --------------------------------------------------------------------- */
789 
790 /*
791  * Lookup a directory entry by its associated cookie.
792  *
793  * Must be called with the directory node locked (shared ok)
794  */
795 struct lubycookie_info {
796 	off_t	cookie;
797 	struct tmpfs_dirent *de;
798 };
799 
800 static int
801 lubycookie_cmp(struct tmpfs_dirent *de, void *arg)
802 {
803 	struct lubycookie_info *info = arg;
804 	off_t cookie = tmpfs_dircookie(de);
805 
806 	if (cookie < info->cookie)
807 		return(-1);
808 	if (cookie > info->cookie)
809 		return(1);
810 	return(0);
811 }
812 
813 static int
814 lubycookie_callback(struct tmpfs_dirent *de, void *arg)
815 {
816 	struct lubycookie_info *info = arg;
817 
818 	if (tmpfs_dircookie(de) == info->cookie) {
819 		info->de = de;
820 		return(-1);
821 	}
822 	return(0);
823 }
824 
825 struct tmpfs_dirent *
826 tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie)
827 {
828 	struct lubycookie_info info;
829 
830 	info.cookie = cookie;
831 	info.de = NULL;
832 	RB_SCAN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree,
833 		lubycookie_cmp, lubycookie_callback, &info);
834 	return (info.de);
835 }
836 
837 /* --------------------------------------------------------------------- */
838 
839 /*
840  * Helper function for tmpfs_readdir.  Returns as much directory entries
841  * as can fit in the uio space.  The read starts at uio->uio_offset.
842  * The function returns 0 on success, -1 if there was not enough space
843  * in the uio structure to hold the directory entry or an appropriate
844  * error code if another error happens.
845  *
846  * Caller must hold the node locked (shared ok)
847  */
848 int
849 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, off_t *cntp)
850 {
851 	int error;
852 	off_t startcookie;
853 	struct tmpfs_dirent *de;
854 
855 	TMPFS_VALIDATE_DIR(node);
856 
857 	/*
858 	 * Locate the first directory entry we have to return.  We have cached
859 	 * the last readdir in the node, so use those values if appropriate.
860 	 * Otherwise do a linear scan to find the requested entry.
861 	 */
862 	startcookie = uio->uio_offset;
863 	KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOT);
864 	KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOTDOT);
865 
866 	if (startcookie == TMPFS_DIRCOOKIE_EOF)
867 		return 0;
868 
869 	de = tmpfs_dir_lookupbycookie(node, startcookie);
870 	if (de == NULL)
871 		return EINVAL;
872 
873 	/*
874 	 * Read as much entries as possible; i.e., until we reach the end of
875 	 * the directory or we exhaust uio space.
876 	 */
877 	do {
878 		ino_t d_ino;
879 		uint8_t d_type;
880 
881 		/* Create a dirent structure representing the current
882 		 * tmpfs_node and fill it. */
883 		d_ino = de->td_node->tn_id;
884 		switch (de->td_node->tn_type) {
885 		case VBLK:
886 			d_type = DT_BLK;
887 			break;
888 
889 		case VCHR:
890 			d_type = DT_CHR;
891 			break;
892 
893 		case VDIR:
894 			d_type = DT_DIR;
895 			break;
896 
897 		case VFIFO:
898 			d_type = DT_FIFO;
899 			break;
900 
901 		case VLNK:
902 			d_type = DT_LNK;
903 			break;
904 
905 		case VREG:
906 			d_type = DT_REG;
907 			break;
908 
909 		case VSOCK:
910 			d_type = DT_SOCK;
911 			break;
912 
913 		default:
914 			panic("tmpfs_dir_getdents: type %p %d",
915 			    de->td_node, (int)de->td_node->tn_type);
916 		}
917 		KKASSERT(de->td_namelen < 256); /* 255 + 1 */
918 
919 		if (vop_write_dirent(&error, uio, d_ino, d_type,
920 		    de->td_namelen, de->td_name)) {
921 			error = -1;
922 			break;
923 		}
924 
925 		(*cntp)++;
926 		de = RB_NEXT(tmpfs_dirtree_cookie,
927 			     node->tn_dir.tn_cookietree, de);
928 	} while (error == 0 && uio->uio_resid > 0 && de != NULL);
929 
930 	/* Update the offset and cache. */
931 	if (de == NULL) {
932 		uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
933 	} else {
934 		uio->uio_offset = tmpfs_dircookie(de);
935 	}
936 
937 	return error;
938 }
939 
940 /* --------------------------------------------------------------------- */
941 
942 /*
943  * Resizes the aobj associated to the regular file pointed to by vp to
944  * the size newsize.  'vp' must point to a vnode that represents a regular
945  * file.  'newsize' must be positive.
946  *
947  * pass trivial as 1 when buf content will be overwritten, otherwise set 0
948  * to be zero filled.
949  *
950  * Returns zero on success or an appropriate error code on failure.
951  *
952  * Caller must hold the node exclusively locked.
953  */
954 int
955 tmpfs_reg_resize(struct vnode *vp, off_t newsize, int trivial)
956 {
957 	int error;
958 	vm_pindex_t newpages, oldpages;
959 	struct tmpfs_mount *tmp;
960 	struct tmpfs_node *node;
961 	off_t oldsize;
962 
963 #ifdef INVARIANTS
964 	KKASSERT(vp->v_type == VREG);
965 	KKASSERT(newsize >= 0);
966 #endif
967 
968 	node = VP_TO_TMPFS_NODE(vp);
969 	tmp = VFS_TO_TMPFS(vp->v_mount);
970 
971 	/*
972 	 * Convert the old and new sizes to the number of pages needed to
973 	 * store them.  It may happen that we do not need to do anything
974 	 * because the last allocated page can accommodate the change on
975 	 * its own.
976 	 */
977 	oldsize = node->tn_size;
978 	oldpages = round_page64(oldsize) / PAGE_SIZE;
979 	KKASSERT(oldpages == node->tn_reg.tn_aobj_pages);
980 	newpages = round_page64(newsize) / PAGE_SIZE;
981 
982 	if (newpages > oldpages &&
983 	   tmp->tm_pages_used + newpages - oldpages > tmp->tm_pages_max) {
984 		error = ENOSPC;
985 		goto out;
986 	}
987 	node->tn_reg.tn_aobj_pages = newpages;
988 	node->tn_size = newsize;
989 
990 	if (newpages != oldpages)
991 		atomic_add_long(&tmp->tm_pages_used, (newpages - oldpages));
992 
993 	/*
994 	 * When adjusting the vnode filesize and its VM object we must
995 	 * also adjust our backing VM object (aobj).  The blocksize
996 	 * used must match the block sized we use for the buffer cache.
997 	 *
998 	 * The backing VM object may contain VM pages as well as swap
999 	 * assignments if we previously renamed main object pages into
1000 	 * it during deactivation.
1001 	 */
1002 	if (newsize < oldsize) {
1003 		vm_pindex_t osize;
1004 		vm_pindex_t nsize;
1005 		vm_object_t aobj;
1006 
1007 		error = nvtruncbuf(vp, newsize, TMPFS_BLKSIZE, -1, 0);
1008 		aobj = node->tn_reg.tn_aobj;
1009 		if (aobj) {
1010 			osize = aobj->size;
1011 			nsize = vp->v_object->size;
1012 			if (nsize < osize) {
1013 				aobj->size = osize;
1014 				swap_pager_freespace(aobj, nsize,
1015 						     osize - nsize);
1016 				vm_object_page_remove(aobj, nsize, osize,
1017 						      FALSE);
1018 			}
1019 		}
1020 	} else {
1021 		vm_object_t aobj;
1022 
1023 		error = nvextendbuf(vp, oldsize, newsize,
1024 				    TMPFS_BLKSIZE, TMPFS_BLKSIZE,
1025 				    -1, -1, trivial);
1026 		aobj = node->tn_reg.tn_aobj;
1027 		if (aobj)
1028 			aobj->size = vp->v_object->size;
1029 	}
1030 
1031 out:
1032 	return error;
1033 }
1034 
1035 /* --------------------------------------------------------------------- */
1036 
1037 /*
1038  * Change flags of the given vnode.
1039  * Caller should execute tmpfs_update on vp after a successful execution.
1040  * The vnode must be locked on entry and remain locked on exit.
1041  */
1042 int
1043 tmpfs_chflags(struct vnode *vp, int vaflags, struct ucred *cred)
1044 {
1045 	int error;
1046 	struct tmpfs_node *node;
1047 	int flags;
1048 
1049 	KKASSERT(vn_islocked(vp));
1050 
1051 	node = VP_TO_TMPFS_NODE(vp);
1052 	flags = node->tn_flags;
1053 
1054 	/* Disallow this operation if the file system is mounted read-only. */
1055 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1056 		return EROFS;
1057 	error = vop_helper_setattr_flags(&flags, vaflags, node->tn_uid, cred);
1058 
1059 	/* Actually change the flags on the node itself */
1060 	if (error == 0) {
1061 		TMPFS_NODE_LOCK(node);
1062 		node->tn_flags = flags;
1063 		node->tn_status |= TMPFS_NODE_CHANGED;
1064 		TMPFS_NODE_UNLOCK(node);
1065 	}
1066 
1067 	KKASSERT(vn_islocked(vp));
1068 
1069 	return error;
1070 }
1071 
1072 /* --------------------------------------------------------------------- */
1073 
1074 /*
1075  * Change access mode on the given vnode.
1076  * Caller should execute tmpfs_update on vp after a successful execution.
1077  * The vnode must be locked on entry and remain locked on exit.
1078  */
1079 int
1080 tmpfs_chmod(struct vnode *vp, mode_t vamode, struct ucred *cred)
1081 {
1082 	struct tmpfs_node *node;
1083 	mode_t cur_mode;
1084 	int error;
1085 
1086 	KKASSERT(vn_islocked(vp));
1087 
1088 	node = VP_TO_TMPFS_NODE(vp);
1089 
1090 	/* Disallow this operation if the file system is mounted read-only. */
1091 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1092 		return EROFS;
1093 
1094 	/* Immutable or append-only files cannot be modified, either. */
1095 	if (node->tn_flags & (IMMUTABLE | APPEND))
1096 		return EPERM;
1097 
1098 	cur_mode = node->tn_mode;
1099 	error = vop_helper_chmod(vp, vamode, cred, node->tn_uid, node->tn_gid,
1100 				 &cur_mode);
1101 
1102 	if (error == 0 &&
1103 	    (node->tn_mode & ALLPERMS) != (cur_mode & ALLPERMS)) {
1104 		TMPFS_NODE_LOCK(node);
1105 		node->tn_mode &= ~ALLPERMS;
1106 		node->tn_mode |= cur_mode & ALLPERMS;
1107 
1108 		node->tn_status |= TMPFS_NODE_CHANGED;
1109 		TMPFS_NODE_UNLOCK(node);
1110 	}
1111 
1112 	KKASSERT(vn_islocked(vp));
1113 
1114 	return 0;
1115 }
1116 
1117 /* --------------------------------------------------------------------- */
1118 
1119 /*
1120  * Change ownership of the given vnode.  At least one of uid or gid must
1121  * be different than VNOVAL.  If one is set to that value, the attribute
1122  * is unchanged.
1123  * Caller should execute tmpfs_update on vp after a successful execution.
1124  * The vnode must be locked on entry and remain locked on exit.
1125  */
1126 int
1127 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred)
1128 {
1129 	mode_t cur_mode;
1130 	uid_t cur_uid;
1131 	gid_t cur_gid;
1132 	struct tmpfs_node *node;
1133 	int error;
1134 
1135 	KKASSERT(vn_islocked(vp));
1136 	node = VP_TO_TMPFS_NODE(vp);
1137 
1138 	/* Disallow this operation if the file system is mounted read-only. */
1139 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1140 		return EROFS;
1141 
1142 	/* Immutable or append-only files cannot be modified, either. */
1143 	if (node->tn_flags & (IMMUTABLE | APPEND))
1144 		return EPERM;
1145 
1146 	cur_uid = node->tn_uid;
1147 	cur_gid = node->tn_gid;
1148 	cur_mode = node->tn_mode;
1149 	error = vop_helper_chown(vp, uid, gid, cred,
1150 				 &cur_uid, &cur_gid, &cur_mode);
1151 
1152 	if (error == 0) {
1153 		TMPFS_NODE_LOCK(node);
1154 		if (cur_uid != node->tn_uid ||
1155 		    cur_gid != node->tn_gid ||
1156 		    cur_mode != node->tn_mode) {
1157 			node->tn_uid = cur_uid;
1158 			node->tn_gid = cur_gid;
1159 			node->tn_mode = cur_mode;
1160 			node->tn_status |= TMPFS_NODE_CHANGED;
1161 		}
1162 		TMPFS_NODE_UNLOCK(node);
1163 	}
1164 
1165 	return error;
1166 }
1167 
1168 /* --------------------------------------------------------------------- */
1169 
1170 /*
1171  * Change size of the given vnode.
1172  * Caller should execute tmpfs_update on vp after a successful execution.
1173  * The vnode must be locked on entry and remain locked on exit.
1174  */
1175 int
1176 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred)
1177 {
1178 	int error;
1179 	struct tmpfs_node *node;
1180 
1181 	KKASSERT(vn_islocked(vp));
1182 
1183 	node = VP_TO_TMPFS_NODE(vp);
1184 
1185 	/* Decide whether this is a valid operation based on the file type. */
1186 	error = 0;
1187 	switch (vp->v_type) {
1188 	case VDIR:
1189 		return EISDIR;
1190 
1191 	case VREG:
1192 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
1193 			return EROFS;
1194 		break;
1195 
1196 	case VBLK:
1197 		/* FALLTHROUGH */
1198 	case VCHR:
1199 		/* FALLTHROUGH */
1200 	case VFIFO:
1201 		/* Allow modifications of special files even if in the file
1202 		 * system is mounted read-only (we are not modifying the
1203 		 * files themselves, but the objects they represent). */
1204 		return 0;
1205 
1206 	default:
1207 		/* Anything else is unsupported. */
1208 		return EOPNOTSUPP;
1209 	}
1210 
1211 	/* Immutable or append-only files cannot be modified, either. */
1212 	if (node->tn_flags & (IMMUTABLE | APPEND))
1213 		return EPERM;
1214 
1215 	error = tmpfs_truncate(vp, size);
1216 	/* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
1217 	 * for us, as will update tn_status; no need to do that here. */
1218 
1219 	KKASSERT(vn_islocked(vp));
1220 
1221 	return error;
1222 }
1223 
1224 /* --------------------------------------------------------------------- */
1225 
1226 /*
1227  * Change access and modification times of the given vnode.
1228  * Caller should execute tmpfs_update on vp after a successful execution.
1229  * The vnode must be locked on entry and remain locked on exit.
1230  */
1231 int
1232 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime,
1233 	      int vaflags, struct ucred *cred)
1234 {
1235 	struct tmpfs_node *node;
1236 
1237 	KKASSERT(vn_islocked(vp));
1238 
1239 	node = VP_TO_TMPFS_NODE(vp);
1240 
1241 	/* Disallow this operation if the file system is mounted read-only. */
1242 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1243 		return EROFS;
1244 
1245 	/* Immutable or append-only files cannot be modified, either. */
1246 	if (node->tn_flags & (IMMUTABLE | APPEND))
1247 		return EPERM;
1248 
1249 	TMPFS_NODE_LOCK(node);
1250 	if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL)
1251 		node->tn_status |= TMPFS_NODE_ACCESSED;
1252 
1253 	if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL) {
1254 		node->tn_status |= TMPFS_NODE_MODIFIED;
1255 		vclrflags(vp, VLASTWRITETS);
1256 	}
1257 
1258 	TMPFS_NODE_UNLOCK(node);
1259 
1260 	tmpfs_itimes(vp, atime, mtime);
1261 
1262 	KKASSERT(vn_islocked(vp));
1263 
1264 	return 0;
1265 }
1266 
1267 /* --------------------------------------------------------------------- */
1268 /* Sync timestamps */
1269 void
1270 tmpfs_itimes(struct vnode *vp, const struct timespec *acc,
1271 	     const struct timespec *mod)
1272 {
1273 	struct tmpfs_node *node;
1274 	struct timespec now;
1275 
1276 	node = VP_TO_TMPFS_NODE(vp);
1277 
1278 	if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
1279 	    TMPFS_NODE_CHANGED)) == 0)
1280 		return;
1281 
1282 	vfs_timestamp(&now);
1283 
1284 	TMPFS_NODE_LOCK(node);
1285 	if (node->tn_status & TMPFS_NODE_ACCESSED) {
1286 		if (acc == NULL)
1287 			 acc = &now;
1288 		node->tn_atime = acc->tv_sec;
1289 		node->tn_atimensec = acc->tv_nsec;
1290 	}
1291 	if (node->tn_status & TMPFS_NODE_MODIFIED) {
1292 		if (mod == NULL)
1293 			mod = &now;
1294 		node->tn_mtime = mod->tv_sec;
1295 		node->tn_mtimensec = mod->tv_nsec;
1296 	}
1297 	if (node->tn_status & TMPFS_NODE_CHANGED) {
1298 		node->tn_ctime = now.tv_sec;
1299 		node->tn_ctimensec = now.tv_nsec;
1300 	}
1301 
1302 	node->tn_status &= ~(TMPFS_NODE_ACCESSED |
1303 			     TMPFS_NODE_MODIFIED |
1304 			     TMPFS_NODE_CHANGED);
1305 	TMPFS_NODE_UNLOCK(node);
1306 }
1307 
1308 /* --------------------------------------------------------------------- */
1309 
1310 void
1311 tmpfs_update(struct vnode *vp)
1312 {
1313 	tmpfs_itimes(vp, NULL, NULL);
1314 }
1315 
1316 /* --------------------------------------------------------------------- */
1317 
1318 /*
1319  * Caller must hold an exclusive node lock.
1320  */
1321 int
1322 tmpfs_truncate(struct vnode *vp, off_t length)
1323 {
1324 	int error;
1325 	struct tmpfs_node *node;
1326 
1327 	node = VP_TO_TMPFS_NODE(vp);
1328 
1329 	if (length < 0) {
1330 		error = EINVAL;
1331 		goto out;
1332 	}
1333 
1334 	if (node->tn_size == length) {
1335 		error = 0;
1336 		goto out;
1337 	}
1338 
1339 	if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
1340 		return (EFBIG);
1341 
1342 
1343 	error = tmpfs_reg_resize(vp, length, 1);
1344 
1345 	if (error == 0)
1346 		node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
1347 
1348 out:
1349 	tmpfs_update(vp);
1350 
1351 	return error;
1352 }
1353 
1354 /* --------------------------------------------------------------------- */
1355 
1356 static ino_t
1357 tmpfs_fetch_ino(struct tmpfs_mount *tmp)
1358 {
1359 	ino_t ret;
1360 
1361 	ret = atomic_fetchadd_64(&tmp->tm_ino, 1);
1362 
1363 	return (ret);
1364 }
1365 
1366 static int
1367 tmpfs_dirtree_compare(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
1368 {
1369 	if (a->td_namelen > b->td_namelen)
1370 		return 1;
1371 	else if (a->td_namelen < b->td_namelen)
1372 		return -1;
1373 	else
1374 		return strncmp(a->td_name, b->td_name, a->td_namelen);
1375 }
1376 
1377 static int
1378 tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
1379 {
1380 	if (a < b)
1381 		return(-1);
1382 	if (a > b)
1383 		return(1);
1384 	return 0;
1385 }
1386