xref: /dflybsd-src/sys/vfs/tmpfs/tmpfs_subr.c (revision b2dae6435bc5f6ad302e31151fc99b6b28f42cca)
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/priv.h>
40 #include <sys/proc.h>
41 #include <sys/stat.h>
42 #include <sys/systm.h>
43 #include <sys/vnode.h>
44 #include <sys/vmmeter.h>
45 
46 #include <vm/vm.h>
47 #include <vm/vm_object.h>
48 #include <vm/vm_page.h>
49 #include <vm/vm_pager.h>
50 #include <vm/vm_extern.h>
51 #include <vm/vm_pageout.h>
52 #include <vm/vm_page2.h>
53 
54 #include <vfs/tmpfs/tmpfs.h>
55 #include <vfs/tmpfs/tmpfs_vnops.h>
56 
57 static ino_t tmpfs_fetch_ino(struct tmpfs_mount *);
58 
59 static int tmpfs_dirtree_compare(struct tmpfs_dirent *a,
60 	struct tmpfs_dirent *b);
61 RB_GENERATE(tmpfs_dirtree, tmpfs_dirent, rb_node, tmpfs_dirtree_compare);
62 
63 static int tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a,
64 	struct tmpfs_dirent *b);
65 RB_GENERATE(tmpfs_dirtree_cookie, tmpfs_dirent,
66 	rb_cookienode, tmpfs_dirtree_compare_cookie);
67 
68 
69 /* --------------------------------------------------------------------- */
70 
71 /*
72  * Allocates a new node of type 'type' inside the 'tmp' mount point, with
73  * its owner set to 'uid', its group to 'gid' and its mode set to 'mode',
74  * using the credentials of the process 'p'.
75  *
76  * If the node type is set to 'VDIR', then the parent parameter must point
77  * to the parent directory of the node being created.  It may only be NULL
78  * while allocating the root node.
79  *
80  * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter
81  * specifies the device the node represents.
82  *
83  * If the node type is set to 'VLNK', then the parameter target specifies
84  * the file name of the target file for the symbolic link that is being
85  * created.
86  *
87  * Note that new nodes are retrieved from the available list if it has
88  * items or, if it is empty, from the node pool as long as there is enough
89  * space to create them.
90  *
91  * Returns zero on success or an appropriate error code on failure.
92  */
93 int
94 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type,
95 		 uid_t uid, gid_t gid, mode_t mode,
96 		 char *target, int rmajor, int rminor,
97 		 struct tmpfs_node **node)
98 {
99 	struct tmpfs_node *nnode;
100 	struct timespec ts;
101 	dev_t rdev;
102 
103 	KKASSERT(IFF(type == VLNK, target != NULL));
104 	KKASSERT(IFF(type == VBLK || type == VCHR, rmajor != VNOVAL));
105 
106 	if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max)
107 		return (ENOSPC);
108 
109 	nnode = objcache_get(tmp->tm_node_pool, M_WAITOK | M_NULLOK);
110 	if (nnode == NULL)
111 		return (ENOSPC);
112 
113 	/* Generic initialization. */
114 	nnode->tn_type = type;
115 	vfs_timestamp(&ts);
116 	nnode->tn_ctime = nnode->tn_mtime = nnode->tn_atime
117 		= ts.tv_sec;
118 	nnode->tn_ctimensec = nnode->tn_mtimensec = nnode->tn_atimensec
119 		= ts.tv_nsec;
120 	nnode->tn_uid = uid;
121 	nnode->tn_gid = gid;
122 	nnode->tn_mode = mode;
123 	nnode->tn_id = tmpfs_fetch_ino(tmp);
124 	nnode->tn_advlock.init_done = 0;
125 	KKASSERT(nnode->tn_links == 0);
126 
127 	/* Type-specific initialization. */
128 	switch (nnode->tn_type) {
129 	case VBLK:
130 	case VCHR:
131 		rdev = makeudev(rmajor, rminor);
132 		if (rdev == NOUDEV) {
133 			objcache_put(tmp->tm_node_pool, nnode);
134 			return(EINVAL);
135 		}
136 		nnode->tn_rdev = rdev;
137 		break;
138 
139 	case VDIR:
140 		RB_INIT(&nnode->tn_dir.tn_dirtree);
141 		RB_INIT(&nnode->tn_dir.tn_cookietree);
142 		nnode->tn_dir.tn_parent = NULL;
143 		nnode->tn_size = 0;
144 		break;
145 
146 	case VFIFO:
147 		/* FALLTHROUGH */
148 	case VSOCK:
149 		break;
150 
151 	case VLNK:
152 		nnode->tn_size = strlen(target);
153 		nnode->tn_link = kmalloc(nnode->tn_size + 1, tmp->tm_name_zone,
154 					 M_WAITOK | M_NULLOK);
155 		if (nnode->tn_link == NULL) {
156 			objcache_put(tmp->tm_node_pool, nnode);
157 			return (ENOSPC);
158 		}
159 		bcopy(target, nnode->tn_link, nnode->tn_size);
160 		nnode->tn_link[nnode->tn_size] = '\0';
161 		break;
162 
163 	case VREG:
164 		nnode->tn_reg.tn_aobj = swap_pager_alloc(NULL, 0,
165 							 VM_PROT_DEFAULT, 0);
166 		nnode->tn_reg.tn_aobj_pages = 0;
167 		nnode->tn_size = 0;
168 		vm_object_set_flag(nnode->tn_reg.tn_aobj, OBJ_NOPAGEIN);
169 		break;
170 
171 	default:
172 		panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type);
173 	}
174 
175 	TMPFS_NODE_LOCK(nnode);
176 	TMPFS_LOCK(tmp);
177 	LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries);
178 	tmp->tm_nodes_inuse++;
179 	TMPFS_UNLOCK(tmp);
180 	TMPFS_NODE_UNLOCK(nnode);
181 
182 	*node = nnode;
183 	return 0;
184 }
185 
186 /* --------------------------------------------------------------------- */
187 
188 /*
189  * Destroys the node pointed to by node from the file system 'tmp'.
190  * If the node does not belong to the given mount point, the results are
191  * unpredicted.
192  *
193  * If the node references a directory; no entries are allowed because
194  * their removal could need a recursive algorithm, something forbidden in
195  * kernel space.  Furthermore, there is not need to provide such
196  * functionality (recursive removal) because the only primitives offered
197  * to the user are the removal of empty directories and the deletion of
198  * individual files.
199  *
200  * Note that nodes are not really deleted; in fact, when a node has been
201  * allocated, it cannot be deleted during the whole life of the file
202  * system.  Instead, they are moved to the available list and remain there
203  * until reused.
204  *
205  * A caller must have TMPFS_NODE_LOCK(node) and this function unlocks it.
206  */
207 void
208 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node)
209 {
210 	vm_pindex_t pages = 0;
211 
212 #ifdef INVARIANTS
213 	TMPFS_ASSERT_ELOCKED(node);
214 	KKASSERT(node->tn_vnode == NULL);
215 #endif
216 
217 	TMPFS_LOCK(tmp);
218 	LIST_REMOVE(node, tn_entries);
219 	tmp->tm_nodes_inuse--;
220 	TMPFS_UNLOCK(tmp);
221 	TMPFS_NODE_UNLOCK(node);  /* Caller has this lock */
222 
223 	switch (node->tn_type) {
224 	case VNON:
225 		/* Do not do anything.  VNON is provided to let the
226 		 * allocation routine clean itself easily by avoiding
227 		 * duplicating code in it. */
228 		/* FALLTHROUGH */
229 	case VBLK:
230 		/* FALLTHROUGH */
231 	case VCHR:
232 		/* FALLTHROUGH */
233 		break;
234 	case VDIR:
235 		/*
236 		 * The parent link can be NULL if this is the root
237 		 * node or if it is a directory node that was rmdir'd.
238 		 *
239 		 * XXX what if node is a directory which still contains
240 		 * directory entries (e.g. due to a forced umount) ?
241 		 */
242 		node->tn_size = 0;
243 		KKASSERT(node->tn_dir.tn_parent == NULL);
244 
245 		/*
246 		 * If the root node is being destroyed don't leave a
247 		 * dangling pointer in tmpfs_mount.
248 		 */
249 		if (node == tmp->tm_root)
250 			tmp->tm_root = NULL;
251 		break;
252 	case VFIFO:
253 		/* FALLTHROUGH */
254 	case VSOCK:
255 		break;
256 
257 	case VLNK:
258 		kfree(node->tn_link, tmp->tm_name_zone);
259 		node->tn_link = NULL;
260 		node->tn_size = 0;
261 		break;
262 
263 	case VREG:
264 		if (node->tn_reg.tn_aobj != NULL)
265 			vm_object_deallocate(node->tn_reg.tn_aobj);
266 		node->tn_reg.tn_aobj = NULL;
267 		pages = node->tn_reg.tn_aobj_pages;
268 		break;
269 
270 	default:
271 		panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type);
272 	}
273 
274 	/*
275 	 * Clean up fields for the next allocation.  The objcache only ctors
276 	 * new allocations.
277 	 */
278 	tmpfs_node_ctor(node, NULL, 0);
279 	objcache_put(tmp->tm_node_pool, node);
280 	/* node is now invalid */
281 
282 	if (pages)
283 		atomic_add_long(&tmp->tm_pages_used, -(long)pages);
284 }
285 
286 /* --------------------------------------------------------------------- */
287 
288 /*
289  * Allocates a new directory entry for the node node with a name of name.
290  * The new directory entry is returned in *de.
291  *
292  * The link count of node is increased by one to reflect the new object
293  * referencing it.
294  *
295  * Returns zero on success or an appropriate error code on failure.
296  */
297 int
298 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
299 		   const char *name, uint16_t len, struct tmpfs_dirent **de)
300 {
301 	struct tmpfs_dirent *nde;
302 
303 	nde = objcache_get(tmp->tm_dirent_pool, M_WAITOK);
304 	nde->td_name = kmalloc(len + 1, tmp->tm_name_zone, M_WAITOK | M_NULLOK);
305 	if (nde->td_name == NULL) {
306 		objcache_put(tmp->tm_dirent_pool, nde);
307 		*de = NULL;
308 		return (ENOSPC);
309 	}
310 	nde->td_namelen = len;
311 	bcopy(name, nde->td_name, len);
312 	nde->td_name[len] = '\0';
313 
314 	nde->td_node = node;
315 
316 	atomic_add_int(&node->tn_links, 1);
317 
318 	*de = nde;
319 
320 	return 0;
321 }
322 
323 /* --------------------------------------------------------------------- */
324 
325 /*
326  * Frees a directory entry.  It is the caller's responsibility to destroy
327  * the node referenced by it if needed.
328  *
329  * The link count of node is decreased by one to reflect the removal of an
330  * object that referenced it.  This only happens if 'node_exists' is true;
331  * otherwise the function will not access the node referred to by the
332  * directory entry, as it may already have been released from the outside.
333  */
334 void
335 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de)
336 {
337 	struct tmpfs_node *node;
338 
339 	node = de->td_node;
340 
341 	KKASSERT(node->tn_links > 0);
342 	atomic_add_int(&node->tn_links, -1);
343 
344 	kfree(de->td_name, tmp->tm_name_zone);
345 	de->td_namelen = 0;
346 	de->td_name = NULL;
347 	de->td_node = NULL;
348 	objcache_put(tmp->tm_dirent_pool, de);
349 }
350 
351 /* --------------------------------------------------------------------- */
352 
353 /*
354  * Allocates a new vnode for the node node or returns a new reference to
355  * an existing one if the node had already a vnode referencing it.  The
356  * resulting locked vnode is returned in *vpp.
357  *
358  * Returns zero on success or an appropriate error code on failure.
359  *
360  * The caller must ensure that node cannot go away (usually by holding
361  * the related directory entry).
362  *
363  * If dnode is non-NULL this routine avoids deadlocking against it but
364  * can return EAGAIN.  Caller must try again.  The dnode lock will cycle
365  * in this case, it remains locked on return in all cases.  dnode must
366  * be shared-locked.
367  */
368 int
369 tmpfs_alloc_vp(struct mount *mp,
370 	       struct tmpfs_node *dnode, struct tmpfs_node *node, int lkflag,
371 	       struct vnode **vpp)
372 {
373 	int error = 0;
374 	struct vnode *vp;
375 
376 loop:
377 	vp = NULL;
378 	if (node->tn_vnode == NULL) {
379 		error = getnewvnode(VT_TMPFS, mp, &vp,
380 				    VLKTIMEOUT, LK_CANRECURSE);
381 		if (error)
382 			goto out;
383 	}
384 
385 	/*
386 	 * Interlocked extraction from node.  This can race many things.
387 	 * We have to get a soft reference on the vnode while we hold
388 	 * the node locked, then acquire it properly and check for races.
389 	 */
390 	TMPFS_NODE_LOCK(node);
391 	if (node->tn_vnode) {
392 		if (vp) {
393 			vp->v_type = VBAD;
394 			vx_put(vp);
395 		}
396 		vp = node->tn_vnode;
397 
398 		KKASSERT((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0);
399 		vhold(vp);
400 		TMPFS_NODE_UNLOCK(node);
401 
402 		if (dnode) {
403 			/*
404 			 * Special-case handling to avoid deadlocking against
405 			 * dnode.  This case has been validated and occurs
406 			 * every so often during synth builds.
407 			 */
408 			if (vget(vp, (lkflag & ~LK_RETRY) |
409 				     LK_NOWAIT |
410 				     LK_EXCLUSIVE) != 0) {
411 				TMPFS_NODE_UNLOCK(dnode);
412 				if (vget(vp, (lkflag & ~LK_RETRY) |
413 					     LK_SLEEPFAIL |
414 					     LK_EXCLUSIVE) == 0) {
415 					vn_unlock(vp);
416 				}
417 				vdrop(vp);
418 				TMPFS_NODE_LOCK_SH(dnode);
419 
420 				return EAGAIN;
421 			}
422 		} else {
423 			/*
424 			 * Normal path
425 			 */
426 			if (vget(vp, lkflag | LK_EXCLUSIVE) != 0) {
427 				vdrop(vp);
428 				goto loop;
429 			}
430 		}
431 		if (node->tn_vnode != vp) {
432 			vput(vp);
433 			vdrop(vp);
434 			goto loop;
435 		}
436 		vdrop(vp);
437 		goto out;
438 	}
439 
440 	/*
441 	 * We need to assign node->tn_vnode.  If vp is NULL, loop up to
442 	 * allocate the vp.  This can happen due to SMP races.
443 	 */
444 	if (vp == NULL) {
445 		TMPFS_NODE_UNLOCK(node);
446 		goto loop;
447 	}
448 
449 	/*
450 	 * This should never happen.
451 	 */
452 	if (node->tn_vpstate & TMPFS_VNODE_DOOMED) {
453 		TMPFS_NODE_UNLOCK(node);
454 		vp->v_type = VBAD;
455 		vx_put(vp);
456 		error = ENOENT;
457 		goto out;
458 	}
459 
460 	KKASSERT(node->tn_vnode == NULL);
461 	KKASSERT(vp != NULL);
462 	vp->v_data = node;
463 	vp->v_type = node->tn_type;
464 
465 	/* Type-specific initialization. */
466 	switch (node->tn_type) {
467 	case VBLK:
468 		/* FALLTHROUGH */
469 	case VCHR:
470 		/* FALLTHROUGH */
471 	case VSOCK:
472 		break;
473 	case VREG:
474 		/*
475 		 * VMIO is mandatory.  Tmpfs also supports KVABIO
476 		 * for its tmpfs_strategy().
477 		 */
478 		vsetflags(vp, VKVABIO);
479 		vinitvmio(vp, node->tn_size, node->tn_blksize, -1);
480 		break;
481 	case VLNK:
482 		break;
483 	case VFIFO:
484 		vp->v_ops = &mp->mnt_vn_fifo_ops;
485 		break;
486 	case VDIR:
487 		break;
488 
489 	default:
490 		panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type);
491 	}
492 
493 	node->tn_vnode = vp;
494 	TMPFS_NODE_UNLOCK(node);
495 
496 	vx_downgrade(vp);
497 out:
498 	*vpp = vp;
499 	KKASSERT(IFF(error == 0, *vpp != NULL && vn_islocked(*vpp)));
500 
501 	return error;
502 }
503 
504 /* --------------------------------------------------------------------- */
505 
506 /*
507  * Allocates a new file of type 'type' and adds it to the parent directory
508  * 'dvp'; this addition is done using the component name given in 'cnp'.
509  * The ownership of the new file is automatically assigned based on the
510  * credentials of the caller (through 'cnp'), the group is set based on
511  * the parent directory and the mode is determined from the 'vap' argument.
512  * If successful, *vpp holds a vnode to the newly created file and zero
513  * is returned.  Otherwise *vpp is NULL and the function returns an
514  * appropriate error code.
515  */
516 int
517 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap,
518 		 struct namecache *ncp, struct ucred *cred, char *target)
519 {
520 	int error;
521 	struct tmpfs_dirent *de;
522 	struct tmpfs_mount *tmp;
523 	struct tmpfs_node *dnode;
524 	struct tmpfs_node *node;
525 
526 	tmp = VFS_TO_TMPFS(dvp->v_mount);
527 	dnode = VP_TO_TMPFS_DIR(dvp);
528 	*vpp = NULL;
529 
530 	/*
531 	 * If the directory was removed but a process was CD'd into it,
532 	 * we do not allow any more file/dir creation within it.  Otherwise
533 	 * we will lose track of it.
534 	 */
535 	KKASSERT(dnode->tn_type == VDIR);
536 	if (dnode != tmp->tm_root && dnode->tn_dir.tn_parent == NULL)
537 		return ENOENT;
538 
539 	/*
540 	 * Make sure the link count does not overflow.
541 	 */
542 	if (vap->va_type == VDIR && dnode->tn_links >= LINK_MAX)
543 		return EMLINK;
544 
545 	/* Allocate a node that represents the new file. */
546 	error = tmpfs_alloc_node(tmp, vap->va_type, cred->cr_uid,
547 				 dnode->tn_gid, vap->va_mode, target,
548 				 vap->va_rmajor, vap->va_rminor, &node);
549 	if (error != 0)
550 		return error;
551 	TMPFS_NODE_LOCK(node);
552 
553 	/* Allocate a directory entry that points to the new file. */
554 	error = tmpfs_alloc_dirent(tmp, node, ncp->nc_name, ncp->nc_nlen, &de);
555 	if (error != 0) {
556 		tmpfs_free_node(tmp, node);
557 		/* eats node lock */
558 		return error;
559 	}
560 
561 	/* Allocate a vnode for the new file. */
562 	error = tmpfs_alloc_vp(dvp->v_mount, NULL, node, LK_EXCLUSIVE, vpp);
563 	if (error != 0) {
564 		tmpfs_free_dirent(tmp, de);
565 		tmpfs_free_node(tmp, node);
566 		/* eats node lock */
567 		return error;
568 	}
569 
570 	/*
571 	 * Now that all required items are allocated, we can proceed to
572 	 * insert the new node into the directory, an operation that
573 	 * cannot fail.
574 	 */
575 	tmpfs_dir_attach(dnode, de);
576 	TMPFS_NODE_UNLOCK(node);
577 
578 	return error;
579 }
580 
581 /* --------------------------------------------------------------------- */
582 
583 /*
584  * Attaches the directory entry de to the directory represented by dnode.
585  * Note that this does not change the link count of the node pointed by
586  * the directory entry, as this is done by tmpfs_alloc_dirent.
587  */
588 void
589 tmpfs_dir_attach(struct tmpfs_node *dnode, struct tmpfs_dirent *de)
590 {
591 	struct tmpfs_node *node = de->td_node;
592 
593 	TMPFS_NODE_LOCK(dnode);
594 	if (node && node->tn_type == VDIR) {
595 		TMPFS_NODE_LOCK(node);
596 		atomic_add_int(&node->tn_links, 1);
597 		node->tn_status |= TMPFS_NODE_CHANGED;
598 		node->tn_dir.tn_parent = dnode;
599 		atomic_add_int(&dnode->tn_links, 1);
600 		TMPFS_NODE_UNLOCK(node);
601 	}
602 	RB_INSERT(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de);
603 	RB_INSERT(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de);
604 	dnode->tn_size += sizeof(struct tmpfs_dirent);
605 	dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
606 			    TMPFS_NODE_MODIFIED;
607 	TMPFS_NODE_UNLOCK(dnode);
608 }
609 
610 /* --------------------------------------------------------------------- */
611 
612 /*
613  * Detaches the directory entry de from the directory represented by dnode.
614  * Note that this does not change the link count of the node pointed by
615  * the directory entry, as this is done by tmpfs_free_dirent.
616  */
617 void
618 tmpfs_dir_detach(struct tmpfs_node *dnode, struct tmpfs_dirent *de)
619 {
620 	struct tmpfs_node *node = de->td_node;
621 
622 	TMPFS_NODE_LOCK(dnode);
623 	RB_REMOVE(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de);
624 	RB_REMOVE(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de);
625 	dnode->tn_size -= sizeof(struct tmpfs_dirent);
626 	dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
627 			    TMPFS_NODE_MODIFIED;
628 	TMPFS_NODE_UNLOCK(dnode);
629 
630 	/*
631 	 * Clean out the tn_parent pointer immediately when removing a
632 	 * directory.
633 	 *
634 	 * Removal of the parent linkage also cleans out the extra tn_links
635 	 * count we had on both node and dnode.
636 	 *
637 	 * node can be NULL (typ during a forced umount), in which case
638 	 * the mount code is dealing with the linkages from a linked list
639 	 * scan.
640 	 */
641 	if (node && node->tn_type == VDIR && node->tn_dir.tn_parent) {
642 		TMPFS_NODE_LOCK(dnode);
643 		TMPFS_NODE_LOCK(node);
644 		KKASSERT(node->tn_dir.tn_parent == dnode);
645 		atomic_add_int(&dnode->tn_links, -1);
646 		atomic_add_int(&node->tn_links, -1);
647 		node->tn_dir.tn_parent = NULL;
648 		TMPFS_NODE_UNLOCK(node);
649 		TMPFS_NODE_UNLOCK(dnode);
650 	}
651 }
652 
653 /* --------------------------------------------------------------------- */
654 
655 /*
656  * Looks for a directory entry in the directory represented by node.
657  * 'ncp' describes the name of the entry to look for.  Note that the .
658  * and .. components are not allowed as they do not physically exist
659  * within directories.
660  *
661  * Returns a pointer to the entry when found, otherwise NULL.
662  *
663  * Caller must hold the node locked (shared ok)
664  */
665 struct tmpfs_dirent *
666 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f,
667 		 struct namecache *ncp)
668 {
669 	struct tmpfs_dirent *de;
670 	int len = ncp->nc_nlen;
671 	struct tmpfs_dirent wanted;
672 
673 	wanted.td_namelen = len;
674 	wanted.td_name = ncp->nc_name;
675 
676 	TMPFS_VALIDATE_DIR(node);
677 
678 	de = RB_FIND(tmpfs_dirtree, &node->tn_dir.tn_dirtree, &wanted);
679 
680 	KKASSERT(f == NULL || de == NULL || f == de->td_node);
681 
682 	return de;
683 }
684 
685 /* --------------------------------------------------------------------- */
686 
687 /*
688  * Helper function for tmpfs_readdir.  Creates a '.' entry for the given
689  * directory and returns it in the uio space.  The function returns 0
690  * on success, -1 if there was not enough space in the uio structure to
691  * hold the directory entry or an appropriate error code if another
692  * error happens.
693  */
694 int
695 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio)
696 {
697 	int error;
698 
699 	TMPFS_VALIDATE_DIR(node);
700 	KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOT);
701 
702 	if (vop_write_dirent(&error, uio, node->tn_id, DT_DIR, 1, "."))
703 		return -1;
704 	if (error == 0)
705 		uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT;
706 	return error;
707 }
708 
709 /* --------------------------------------------------------------------- */
710 
711 /*
712  * Helper function for tmpfs_readdir.  Creates a '..' entry for the given
713  * directory and returns it in the uio space.  The function returns 0
714  * on success, -1 if there was not enough space in the uio structure to
715  * hold the directory entry or an appropriate error code if another
716  * error happens.
717  */
718 int
719 tmpfs_dir_getdotdotdent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
720 			struct uio *uio)
721 {
722 	int error;
723 	ino_t d_ino;
724 
725 	TMPFS_VALIDATE_DIR(node);
726 	KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
727 
728 	if (node->tn_dir.tn_parent) {
729 		TMPFS_NODE_LOCK(node);
730 		if (node->tn_dir.tn_parent)
731 			d_ino = node->tn_dir.tn_parent->tn_id;
732 		else
733 			d_ino = tmp->tm_root->tn_id;
734 		TMPFS_NODE_UNLOCK(node);
735 	} else {
736 		d_ino = tmp->tm_root->tn_id;
737 	}
738 
739 	if (vop_write_dirent(&error, uio, d_ino, DT_DIR, 2, ".."))
740 		return -1;
741 	if (error == 0) {
742 		struct tmpfs_dirent *de;
743 		de = RB_MIN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree);
744 		if (de == NULL)
745 			uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
746 		else
747 			uio->uio_offset = tmpfs_dircookie(de);
748 	}
749 	return error;
750 }
751 
752 /* --------------------------------------------------------------------- */
753 
754 /*
755  * Lookup a directory entry by its associated cookie.
756  *
757  * Must be called with the directory node locked (shared ok)
758  */
759 struct lubycookie_info {
760 	off_t	cookie;
761 	struct tmpfs_dirent *de;
762 };
763 
764 static int
765 lubycookie_cmp(struct tmpfs_dirent *de, void *arg)
766 {
767 	struct lubycookie_info *info = arg;
768 	off_t cookie = tmpfs_dircookie(de);
769 
770 	if (cookie < info->cookie)
771 		return(-1);
772 	if (cookie > info->cookie)
773 		return(1);
774 	return(0);
775 }
776 
777 static int
778 lubycookie_callback(struct tmpfs_dirent *de, void *arg)
779 {
780 	struct lubycookie_info *info = arg;
781 
782 	if (tmpfs_dircookie(de) == info->cookie) {
783 		info->de = de;
784 		return(-1);
785 	}
786 	return(0);
787 }
788 
789 struct tmpfs_dirent *
790 tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie)
791 {
792 	struct lubycookie_info info;
793 
794 	info.cookie = cookie;
795 	info.de = NULL;
796 	RB_SCAN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree,
797 		lubycookie_cmp, lubycookie_callback, &info);
798 	return (info.de);
799 }
800 
801 /* --------------------------------------------------------------------- */
802 
803 /*
804  * Helper function for tmpfs_readdir.  Returns as much directory entries
805  * as can fit in the uio space.  The read starts at uio->uio_offset.
806  * The function returns 0 on success, -1 if there was not enough space
807  * in the uio structure to hold the directory entry or an appropriate
808  * error code if another error happens.
809  *
810  * Caller must hold the node locked (shared ok)
811  */
812 int
813 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, off_t *cntp)
814 {
815 	int error;
816 	off_t startcookie;
817 	struct tmpfs_dirent *de;
818 
819 	TMPFS_VALIDATE_DIR(node);
820 
821 	/*
822 	 * Locate the first directory entry we have to return.  We have cached
823 	 * the last readdir in the node, so use those values if appropriate.
824 	 * Otherwise do a linear scan to find the requested entry.
825 	 */
826 	startcookie = uio->uio_offset;
827 	KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOT);
828 	KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOTDOT);
829 
830 	if (startcookie == TMPFS_DIRCOOKIE_EOF)
831 		return 0;
832 
833 	de = tmpfs_dir_lookupbycookie(node, startcookie);
834 	if (de == NULL)
835 		return EINVAL;
836 
837 	/*
838 	 * Read as much entries as possible; i.e., until we reach the end of
839 	 * the directory or we exhaust uio space.
840 	 */
841 	do {
842 		ino_t d_ino;
843 		uint8_t d_type;
844 
845 		/* Create a dirent structure representing the current
846 		 * tmpfs_node and fill it. */
847 		d_ino = de->td_node->tn_id;
848 		switch (de->td_node->tn_type) {
849 		case VBLK:
850 			d_type = DT_BLK;
851 			break;
852 
853 		case VCHR:
854 			d_type = DT_CHR;
855 			break;
856 
857 		case VDIR:
858 			d_type = DT_DIR;
859 			break;
860 
861 		case VFIFO:
862 			d_type = DT_FIFO;
863 			break;
864 
865 		case VLNK:
866 			d_type = DT_LNK;
867 			break;
868 
869 		case VREG:
870 			d_type = DT_REG;
871 			break;
872 
873 		case VSOCK:
874 			d_type = DT_SOCK;
875 			break;
876 
877 		default:
878 			panic("tmpfs_dir_getdents: type %p %d",
879 			    de->td_node, (int)de->td_node->tn_type);
880 		}
881 		KKASSERT(de->td_namelen < 256); /* 255 + 1 */
882 
883 		if (vop_write_dirent(&error, uio, d_ino, d_type,
884 		    de->td_namelen, de->td_name)) {
885 			error = -1;
886 			break;
887 		}
888 
889 		(*cntp)++;
890 		de = RB_NEXT(tmpfs_dirtree_cookie,
891 			     node->tn_dir.tn_cookietree, de);
892 	} while (error == 0 && uio->uio_resid > 0 && de != NULL);
893 
894 	/* Update the offset and cache. */
895 	if (de == NULL) {
896 		uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
897 	} else {
898 		uio->uio_offset = tmpfs_dircookie(de);
899 	}
900 
901 	return error;
902 }
903 
904 /* --------------------------------------------------------------------- */
905 
906 /*
907  * Resizes the aobj associated to the regular file pointed to by vp to
908  * the size newsize.  'vp' must point to a vnode that represents a regular
909  * file.  'newsize' must be positive.
910  *
911  * pass NVEXTF_TRIVIAL when buf content will be overwritten, otherwise set 0
912  * to be zero filled.
913  *
914  * Returns zero on success or an appropriate error code on failure.
915  *
916  * Caller must hold the node exclusively locked.
917  */
918 int
919 tmpfs_reg_resize(struct vnode *vp, off_t newsize, int trivial)
920 {
921 	int error;
922 	vm_pindex_t newpages, oldpages;
923 	struct tmpfs_mount *tmp;
924 	struct tmpfs_node *node;
925 	off_t oldsize;
926 	int nvextflags;
927 
928 #ifdef INVARIANTS
929 	KKASSERT(vp->v_type == VREG);
930 	KKASSERT(newsize >= 0);
931 #endif
932 
933 	node = VP_TO_TMPFS_NODE(vp);
934 	tmp = VFS_TO_TMPFS(vp->v_mount);
935 
936 	/*
937 	 * Convert the old and new sizes to the number of pages needed to
938 	 * store them.  It may happen that we do not need to do anything
939 	 * because the last allocated page can accommodate the change on
940 	 * its own.
941 	 */
942 	oldsize = node->tn_size;
943 	oldpages = round_page64(oldsize) / PAGE_SIZE;
944 	KKASSERT(oldpages == node->tn_reg.tn_aobj_pages);
945 	newpages = round_page64(newsize) / PAGE_SIZE;
946 
947 	if (newpages > oldpages &&
948 	   tmp->tm_pages_used + newpages - oldpages > tmp->tm_pages_max) {
949 		error = ENOSPC;
950 		goto out;
951 	}
952 	node->tn_reg.tn_aobj_pages = newpages;
953 	node->tn_size = newsize;
954 
955 	if (newpages != oldpages)
956 		atomic_add_long(&tmp->tm_pages_used, (newpages - oldpages));
957 
958 	/*
959 	 * nvextflags to pass along for bdwrite() vs buwrite()
960 	 */
961 	if (vm_pages_needed || vm_paging_needed(0) ||
962 	    tmpfs_bufcache_mode >= 2) {
963 		nvextflags = 0;
964 	} else {
965 		nvextflags = NVEXTF_BUWRITE;
966 	}
967 
968 
969 	/*
970 	 * When adjusting the vnode filesize and its VM object we must
971 	 * also adjust our backing VM object (aobj).  The blocksize
972 	 * used must match the block sized we use for the buffer cache.
973 	 *
974 	 * The backing VM object may contain VM pages as well as swap
975 	 * assignments if we previously renamed main object pages into
976 	 * it during deactivation.
977 	 *
978 	 * To make things easier tmpfs uses a blksize in multiples of
979 	 * PAGE_SIZE, and will only increase the blksize as a small file
980 	 * increases in size.  Once a file has exceeded TMPFS_BLKSIZE (16KB),
981 	 * the blksize is maxed out.  Truncating the file does not reduce
982 	 * the blksize.
983 	 */
984 	if (newsize < oldsize) {
985 		vm_pindex_t osize;
986 		vm_pindex_t nsize;
987 		vm_object_t aobj;
988 
989 		error = nvtruncbuf(vp, newsize, node->tn_blksize,
990 				   -1, nvextflags);
991 		aobj = node->tn_reg.tn_aobj;
992 		if (aobj) {
993 			osize = aobj->size;
994 			nsize = vp->v_object->size;
995 			if (nsize < osize) {
996 				aobj->size = osize;
997 				swap_pager_freespace(aobj, nsize,
998 						     osize - nsize);
999 				vm_object_page_remove(aobj, nsize, osize,
1000 						      FALSE);
1001 			}
1002 		}
1003 	} else {
1004 		vm_object_t aobj;
1005 		int nblksize;
1006 
1007 		/*
1008 		 * The first (and only the first) buffer in the file is resized
1009 		 * in multiples of PAGE_SIZE, up to TMPFS_BLKSIZE.
1010 		 */
1011 		nblksize = node->tn_blksize;
1012 		while (nblksize < TMPFS_BLKSIZE &&
1013 		       nblksize < newsize) {
1014 			nblksize += PAGE_SIZE;
1015 		}
1016 
1017 		if (trivial)
1018 			nvextflags |= NVEXTF_TRIVIAL;
1019 
1020 		error = nvextendbuf(vp, oldsize, newsize,
1021 				    node->tn_blksize, nblksize,
1022 				    -1, -1, nvextflags);
1023 		node->tn_blksize = nblksize;
1024 		aobj = node->tn_reg.tn_aobj;
1025 		if (aobj)
1026 			aobj->size = vp->v_object->size;
1027 	}
1028 
1029 out:
1030 	return error;
1031 }
1032 
1033 /* --------------------------------------------------------------------- */
1034 
1035 /*
1036  * Change flags of the given vnode.
1037  * Caller should execute tmpfs_update on vp after a successful execution.
1038  * The vnode must be locked on entry and remain locked on exit.
1039  */
1040 int
1041 tmpfs_chflags(struct vnode *vp, u_long vaflags, struct ucred *cred)
1042 {
1043 	int error;
1044 	struct tmpfs_node *node;
1045 	int flags;
1046 
1047 	KKASSERT(vn_islocked(vp));
1048 
1049 	node = VP_TO_TMPFS_NODE(vp);
1050 	flags = node->tn_flags;
1051 
1052 	/* Disallow this operation if the file system is mounted read-only. */
1053 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1054 		return EROFS;
1055 	error = vop_helper_setattr_flags(&flags, vaflags, node->tn_uid, cred);
1056 
1057 	/* Actually change the flags on the node itself */
1058 	if (error == 0) {
1059 		TMPFS_NODE_LOCK(node);
1060 		node->tn_flags = flags;
1061 		node->tn_status |= TMPFS_NODE_CHANGED;
1062 		TMPFS_NODE_UNLOCK(node);
1063 	}
1064 
1065 	KKASSERT(vn_islocked(vp));
1066 
1067 	return error;
1068 }
1069 
1070 /* --------------------------------------------------------------------- */
1071 
1072 /*
1073  * Change access mode on the given vnode.
1074  * Caller should execute tmpfs_update on vp after a successful execution.
1075  * The vnode must be locked on entry and remain locked on exit.
1076  */
1077 int
1078 tmpfs_chmod(struct vnode *vp, mode_t vamode, struct ucred *cred)
1079 {
1080 	struct tmpfs_node *node;
1081 	mode_t cur_mode;
1082 	int error;
1083 
1084 	KKASSERT(vn_islocked(vp));
1085 
1086 	node = VP_TO_TMPFS_NODE(vp);
1087 
1088 	/* Disallow this operation if the file system is mounted read-only. */
1089 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1090 		return EROFS;
1091 
1092 	/* Immutable or append-only files cannot be modified, either. */
1093 	if (node->tn_flags & (IMMUTABLE | APPEND))
1094 		return EPERM;
1095 
1096 	cur_mode = node->tn_mode;
1097 	error = vop_helper_chmod(vp, vamode, cred, node->tn_uid, node->tn_gid,
1098 				 &cur_mode);
1099 
1100 	if (error == 0 &&
1101 	    (node->tn_mode & ALLPERMS) != (cur_mode & ALLPERMS)) {
1102 		TMPFS_NODE_LOCK(node);
1103 		node->tn_mode &= ~ALLPERMS;
1104 		node->tn_mode |= cur_mode & ALLPERMS;
1105 
1106 		node->tn_status |= TMPFS_NODE_CHANGED;
1107 		TMPFS_NODE_UNLOCK(node);
1108 	}
1109 
1110 	KKASSERT(vn_islocked(vp));
1111 
1112 	return 0;
1113 }
1114 
1115 /* --------------------------------------------------------------------- */
1116 
1117 /*
1118  * Change ownership of the given vnode.  At least one of uid or gid must
1119  * be different than VNOVAL.  If one is set to that value, the attribute
1120  * is unchanged.
1121  * Caller should execute tmpfs_update on vp after a successful execution.
1122  * The vnode must be locked on entry and remain locked on exit.
1123  */
1124 int
1125 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred)
1126 {
1127 	mode_t cur_mode;
1128 	uid_t cur_uid;
1129 	gid_t cur_gid;
1130 	struct tmpfs_node *node;
1131 	int error;
1132 
1133 	KKASSERT(vn_islocked(vp));
1134 	node = VP_TO_TMPFS_NODE(vp);
1135 
1136 	/* Disallow this operation if the file system is mounted read-only. */
1137 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1138 		return EROFS;
1139 
1140 	/* Immutable or append-only files cannot be modified, either. */
1141 	if (node->tn_flags & (IMMUTABLE | APPEND))
1142 		return EPERM;
1143 
1144 	cur_uid = node->tn_uid;
1145 	cur_gid = node->tn_gid;
1146 	cur_mode = node->tn_mode;
1147 	error = vop_helper_chown(vp, uid, gid, cred,
1148 				 &cur_uid, &cur_gid, &cur_mode);
1149 
1150 	if (error == 0) {
1151 		TMPFS_NODE_LOCK(node);
1152 		if (cur_uid != node->tn_uid ||
1153 		    cur_gid != node->tn_gid ||
1154 		    cur_mode != node->tn_mode) {
1155 			node->tn_uid = cur_uid;
1156 			node->tn_gid = cur_gid;
1157 			node->tn_mode = cur_mode;
1158 			node->tn_status |= TMPFS_NODE_CHANGED;
1159 		}
1160 		TMPFS_NODE_UNLOCK(node);
1161 	}
1162 
1163 	return error;
1164 }
1165 
1166 /* --------------------------------------------------------------------- */
1167 
1168 /*
1169  * Change size of the given vnode.
1170  * Caller should execute tmpfs_update on vp after a successful execution.
1171  * The vnode must be locked on entry and remain locked on exit.
1172  */
1173 int
1174 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred)
1175 {
1176 	int error;
1177 	struct tmpfs_node *node;
1178 
1179 	KKASSERT(vn_islocked(vp));
1180 
1181 	node = VP_TO_TMPFS_NODE(vp);
1182 
1183 	/* Decide whether this is a valid operation based on the file type. */
1184 	error = 0;
1185 	switch (vp->v_type) {
1186 	case VDIR:
1187 		return EISDIR;
1188 
1189 	case VREG:
1190 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
1191 			return EROFS;
1192 		break;
1193 
1194 	case VBLK:
1195 		/* FALLTHROUGH */
1196 	case VCHR:
1197 		/* FALLTHROUGH */
1198 	case VFIFO:
1199 		/* Allow modifications of special files even if in the file
1200 		 * system is mounted read-only (we are not modifying the
1201 		 * files themselves, but the objects they represent). */
1202 		return 0;
1203 
1204 	default:
1205 		/* Anything else is unsupported. */
1206 		return EOPNOTSUPP;
1207 	}
1208 
1209 	/* Immutable or append-only files cannot be modified, either. */
1210 	if (node->tn_flags & (IMMUTABLE | APPEND))
1211 		return EPERM;
1212 
1213 	error = tmpfs_truncate(vp, size);
1214 	/* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
1215 	 * for us, as will update tn_status; no need to do that here. */
1216 
1217 	KKASSERT(vn_islocked(vp));
1218 
1219 	return error;
1220 }
1221 
1222 /* --------------------------------------------------------------------- */
1223 
1224 /*
1225  * Change access and modification times of the given vnode.
1226  * Caller should execute tmpfs_update on vp after a successful execution.
1227  * The vnode must be locked on entry and remain locked on exit.
1228  */
1229 int
1230 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime,
1231 	      int vaflags, struct ucred *cred)
1232 {
1233 	struct tmpfs_node *node;
1234 
1235 	KKASSERT(vn_islocked(vp));
1236 
1237 	node = VP_TO_TMPFS_NODE(vp);
1238 
1239 	/* Disallow this operation if the file system is mounted read-only. */
1240 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
1241 		return EROFS;
1242 
1243 	/* Immutable or append-only files cannot be modified, either. */
1244 	if (node->tn_flags & (IMMUTABLE | APPEND))
1245 		return EPERM;
1246 
1247 	TMPFS_NODE_LOCK(node);
1248 	if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL)
1249 		node->tn_status |= TMPFS_NODE_ACCESSED;
1250 
1251 	if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL) {
1252 		node->tn_status |= TMPFS_NODE_MODIFIED;
1253 		vclrflags(vp, VLASTWRITETS);
1254 	}
1255 
1256 	TMPFS_NODE_UNLOCK(node);
1257 
1258 	tmpfs_itimes(vp, atime, mtime);
1259 
1260 	KKASSERT(vn_islocked(vp));
1261 
1262 	return 0;
1263 }
1264 
1265 /* --------------------------------------------------------------------- */
1266 /* Sync timestamps */
1267 void
1268 tmpfs_itimes(struct vnode *vp, const struct timespec *acc,
1269 	     const struct timespec *mod)
1270 {
1271 	struct tmpfs_node *node;
1272 	struct timespec now;
1273 
1274 	node = VP_TO_TMPFS_NODE(vp);
1275 
1276 	if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
1277 	    TMPFS_NODE_CHANGED)) == 0) {
1278 		return;
1279 	}
1280 
1281 	vfs_timestamp(&now);
1282 
1283 	TMPFS_NODE_LOCK(node);
1284 	if (node->tn_status & TMPFS_NODE_ACCESSED) {
1285 		if (acc == NULL)
1286 			 acc = &now;
1287 		node->tn_atime = acc->tv_sec;
1288 		node->tn_atimensec = acc->tv_nsec;
1289 	}
1290 	if (node->tn_status & TMPFS_NODE_MODIFIED) {
1291 		if (mod == NULL)
1292 			mod = &now;
1293 		node->tn_mtime = mod->tv_sec;
1294 		node->tn_mtimensec = mod->tv_nsec;
1295 	}
1296 	if (node->tn_status & TMPFS_NODE_CHANGED) {
1297 		node->tn_ctime = now.tv_sec;
1298 		node->tn_ctimensec = now.tv_nsec;
1299 	}
1300 
1301 	node->tn_status &= ~(TMPFS_NODE_ACCESSED |
1302 			     TMPFS_NODE_MODIFIED |
1303 			     TMPFS_NODE_CHANGED);
1304 	TMPFS_NODE_UNLOCK(node);
1305 }
1306 
1307 /* --------------------------------------------------------------------- */
1308 
1309 void
1310 tmpfs_update(struct vnode *vp)
1311 {
1312 	tmpfs_itimes(vp, NULL, NULL);
1313 }
1314 
1315 /* --------------------------------------------------------------------- */
1316 
1317 /*
1318  * Caller must hold an exclusive node lock.
1319  */
1320 int
1321 tmpfs_truncate(struct vnode *vp, off_t length)
1322 {
1323 	int error;
1324 	struct tmpfs_node *node;
1325 
1326 	node = VP_TO_TMPFS_NODE(vp);
1327 
1328 	if (length < 0) {
1329 		error = EINVAL;
1330 		goto out;
1331 	}
1332 
1333 	if (node->tn_size == length) {
1334 		error = 0;
1335 		goto out;
1336 	}
1337 
1338 	if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
1339 		return (EFBIG);
1340 
1341 
1342 	error = tmpfs_reg_resize(vp, length, 1);
1343 
1344 	if (error == 0)
1345 		node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
1346 
1347 out:
1348 	tmpfs_update(vp);
1349 
1350 	return error;
1351 }
1352 
1353 /* --------------------------------------------------------------------- */
1354 
1355 static ino_t
1356 tmpfs_fetch_ino(struct tmpfs_mount *tmp)
1357 {
1358 	ino_t ret;
1359 
1360 	ret = atomic_fetchadd_64(&tmp->tm_ino, 1);
1361 
1362 	return (ret);
1363 }
1364 
1365 static int
1366 tmpfs_dirtree_compare(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
1367 {
1368 	if (a->td_namelen > b->td_namelen)
1369 		return 1;
1370 	else if (a->td_namelen < b->td_namelen)
1371 		return -1;
1372 	else
1373 		return strncmp(a->td_name, b->td_name, a->td_namelen);
1374 }
1375 
1376 static int
1377 tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
1378 {
1379 	if (a < b)
1380 		return(-1);
1381 	if (a > b)
1382 		return(1);
1383 	return 0;
1384 }
1385 
1386 /*
1387  * Lock for rename.  The namecache entries are already locked so
1388  * theoretically we should be able to lock the directories in any
1389  * order.  Underlying files must be locked after the related directory.
1390  */
1391 void
1392 tmpfs_lock4(struct tmpfs_node *node1, struct tmpfs_node *node2,
1393 	    struct tmpfs_node *node3, struct tmpfs_node *node4)
1394 {
1395 	TMPFS_NODE_LOCK(node1);		/* fdir */
1396 	TMPFS_NODE_LOCK(node3);		/* ffile */
1397 	TMPFS_NODE_LOCK(node2);		/* tdir */
1398 	if (node4)
1399 		TMPFS_NODE_LOCK(node4);	/* tfile */
1400 }
1401 
1402 void
1403 tmpfs_unlock4(struct tmpfs_node *node1, struct tmpfs_node *node2,
1404 	      struct tmpfs_node *node3, struct tmpfs_node *node4)
1405 {
1406 	if (node4)
1407 		TMPFS_NODE_UNLOCK(node4);
1408 	TMPFS_NODE_UNLOCK(node2);
1409 	TMPFS_NODE_UNLOCK(node3);
1410 	TMPFS_NODE_UNLOCK(node1);
1411 }
1412