xref: /dflybsd-src/sys/vfs/msdosfs/msdosfs_denode.c (revision ed183f8c2f9bb14cbccb8377f3cdd29e0971d8a0)
1 /* $FreeBSD$ */
2 /*	$NetBSD: msdosfs_denode.c,v 1.28 1998/02/10 14:10:00 mrg Exp $	*/
3 
4 /*-
5  * SPDX-License-Identifier: BSD-4-Clause
6  *
7  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
8  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
9  * All rights reserved.
10  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by TooLs GmbH.
23  * 4. The name of TooLs GmbH may not be used to endorse or promote products
24  *    derived from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
32  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
33  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
34  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
35  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 /*-
38  * Written by Paul Popelka (paulp@uts.amdahl.com)
39  *
40  * You can do anything you want with this software, just don't say you wrote
41  * it, and don't remove this notice.
42  *
43  * This software is provided "as is".
44  *
45  * The author supplies this software to be publicly redistributed on the
46  * understanding that the author is not responsible for the correct
47  * functioning of this software in any circumstances and is not liable for
48  * any damages caused by this software.
49  *
50  * October 1992
51  */
52 
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/buf.h>
56 #include <sys/kernel.h>
57 #include <sys/malloc.h>
58 #include <sys/proc.h>
59 #include <sys/mount.h>
60 #include <sys/vnode.h>
61 #include <sys/time.h>
62 
63 #include <vm/vm.h>
64 #include <vm/vm_extern.h>
65 
66 #include <sys/buf2.h>
67 
68 #include "bpb.h"
69 #include "msdosfsmount.h"
70 #include "direntry.h"
71 #include "denode.h"
72 #include "fat.h"
73 
74 static MALLOC_DEFINE(M_MSDOSFSNODE, "MSDOSFS node", "MSDOSFS vnode private part");
75 
76 /*
77  * Hash table caching denode instances.
78  *
79  * denodes are keyed by the disk location (cluster num, entry offset) of the
80  * directory entry of the file they represent.
81  *
82  * denodes representing deleted but still opened files are left in this cache
83  * until reclaimed.  Deleted directory entries can be reused when files are
84  * renamed or new files created.  As a consequence, several denodes associated
85  * with the same entry may coexist in this cache as long as a single one of
86  * them map to an existing file (de_refcnt > 0).
87  *
88  * R/w access to this cache is protected by dehash_token.
89  */
90 static struct denode **dehashtbl;
91 static u_long dehash;			/* size of hash table - 1 */
92 static struct lwkt_token dehash_token;
93 
94 #define	DEHASH(dev, dcl, doff)	(dehashtbl[(minor(dev) + (dcl) + (doff) / \
95 				sizeof(struct direntry)) & dehash])
96 
97 /*ARGSUSED*/
98 int
99 msdosfs_init(struct vfsconf *vfsp)
100 {
101 	dehash = vfs_inodehashsize();
102 	dehashtbl = kmalloc(sizeof(void *) * dehash,
103 			    M_MSDOSFSMNT, M_WAITOK|M_ZERO);
104 	--dehash;
105 	lwkt_token_init(&dehash_token, "msdosihash");
106 
107 	return (0);
108 }
109 
110 int
111 msdosfs_uninit(struct vfsconf *vfsp)
112 {
113 	if (dehashtbl)
114 		kfree(dehashtbl, M_MSDOSFSMNT);
115 	return (0);
116 }
117 
118 static struct denode *
119 msdosfs_hashget(cdev_t dev, u_long dirclust, u_long diroff)
120 {
121 	struct denode *dep;
122 	struct vnode *vp;
123 
124 	lwkt_gettoken(&dehash_token);
125 loop:
126 	for (dep = DEHASH(dev, dirclust, diroff); dep; dep = dep->de_next) {
127 		if (dirclust != dep->de_dirclust
128 		    || diroff != dep->de_diroffset
129 		    || dev != dep->de_dev
130 		    || dep->de_refcnt <= 0) {
131 			continue;
132 		}
133 		vp = DETOV(dep);
134 		if (vget(vp, LK_EXCLUSIVE))
135 			goto loop;
136 
137 		/*
138 		 * We must check to see if the inode has been ripped
139 		 * out from under us after blocking.
140 		 */
141 		for (dep = DEHASH(dev, dirclust, diroff); dep;
142 		     dep = dep->de_next) {
143 			if (dirclust == dep->de_dirclust
144 			    && diroff == dep->de_diroffset
145 			    && dev == dep->de_dev
146 			    && dep->de_refcnt > 0) {
147 				break;
148 			}
149 		}
150 		if (dep == NULL || DETOV(dep) != vp) {
151 			vput(vp);
152 			goto loop;
153 		}
154 		lwkt_reltoken(&dehash_token);
155 		return (dep);
156 	}
157 	lwkt_reltoken(&dehash_token);
158 	return (NULL);
159 }
160 
161 /*
162  * Try to insert specified denode into the hash table.  Return 0 on success
163  * and EBUSY if there is already a denode with the same key.
164  */
165 static
166 int
167 msdosfs_hashins(struct denode *dep)
168 {
169 	struct denode **depp, *deq;
170 
171 	lwkt_gettoken(&dehash_token);
172 	depp = &DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
173 	while ((deq = *depp) != NULL) {
174 		if (deq->de_dev == dep->de_dev &&
175 		    deq->de_dirclust == dep->de_dirclust &&
176 		    deq->de_diroffset == dep->de_diroffset &&
177 		    deq->de_refcnt > 0) {
178 			lwkt_reltoken(&dehash_token);
179 			return(EBUSY);
180 		}
181 		depp = &deq->de_next;
182 	}
183 	dep->de_next = NULL;
184 	*depp = dep;
185 	lwkt_reltoken(&dehash_token);
186 	return(0);
187 }
188 
189 static
190 void
191 msdosfs_hashrem(struct denode *dep)
192 {
193 	struct denode **depp, *deq;
194 
195 	lwkt_gettoken(&dehash_token);
196 	depp = &DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
197 	while ((deq = *depp) != NULL) {
198 		if (dep == deq)
199 			break;
200 		depp = &deq->de_next;
201 	}
202 	KKASSERT(dep == deq);
203 	*depp = dep->de_next;
204 	dep->de_next = NULL;
205 	lwkt_reltoken(&dehash_token);
206 }
207 
208 void
209 msdosfs_reinsert(struct denode *ip, u_long new_dirclust, u_long new_diroffset)
210 {
211 	int error;
212 
213 	lwkt_gettoken(&dehash_token);
214 	msdosfs_hashrem(ip);
215 	ip->de_dirclust = new_dirclust;
216 	ip->de_diroffset = new_diroffset;
217 	error = msdosfs_hashins(ip);
218 	KASSERT(!error, ("msdosfs_reinsert: insertion failed %d", error));
219 	lwkt_reltoken(&dehash_token);
220 }
221 
222 /*
223  * If deget() succeeds it returns with the gotten denode locked().
224  *
225  * pmp	     - address of msdosfsmount structure of the filesystem containing
226  *	       the denode of interest.  The address of
227  *	       the msdosfsmount structure are used.
228  * dirclust  - which cluster bp contains, if dirclust is 0 (root directory)
229  *	       diroffset is relative to the beginning of the root directory,
230  *	       otherwise it is cluster relative.
231  * diroffset - offset past begin of cluster of denode we want
232  * depp	     - returns the address of the gotten denode.
233  */
234 int
235 deget(struct msdosfsmount *pmp, u_long dirclust, u_long diroffset,
236     struct denode **depp)
237 {
238 	int error;
239 	cdev_t dev = pmp->pm_dev;
240 	struct mount *mntp = pmp->pm_mountp;
241 	struct direntry *direntptr;
242 	struct denode *ldep;
243 	struct vnode *nvp;
244 	struct buf *bp;
245 
246 	mprintf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n",
247 	    pmp, dirclust, diroffset, depp);
248 
249 	/*
250 	 * On FAT32 filesystems, root is a (more or less) normal
251 	 * directory
252 	 */
253 	if (FAT32(pmp) && dirclust == MSDOSFSROOT)
254 		dirclust = pmp->pm_rootdirblk;
255 
256 again:
257 	/*
258 	 * See if the denode is in the denode cache. Use the location of
259 	 * the directory entry to compute the hash value. For subdir use
260 	 * address of "." entry. For root dir (if not FAT32) use cluster
261 	 * MSDOSFSROOT, offset MSDOSFSROOT_OFS
262 	 *
263 	 * NOTE: The check for de_refcnt > 0 below insures the denode being
264 	 * examined does not represent an unlinked but still open file.
265 	 * These files are not to be accessible even when the directory
266 	 * entry that represented the file happens to be reused while the
267 	 * deleted file is still open.
268 	 */
269 	ldep = msdosfs_hashget(dev, dirclust, diroffset);
270 	if (ldep) {
271 		*depp = ldep;
272 		return (0);
273 	}
274 
275 	/*
276 	 * Do the MALLOC before the getnewvnode since doing so afterward
277 	 * might cause a bogus v_data pointer to get dereferenced
278 	 * elsewhere if MALLOC should block.
279 	 */
280 	ldep = kmalloc(sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK | M_ZERO);
281 
282 	/*
283 	 * Directory entry was not in cache, have to create a vnode and
284 	 * copy it from the passed disk buffer.
285 	 */
286 
287 	/* getnewvnode() does a vref() on the vnode */
288 	error = getnewvnode(VT_MSDOSFS, mntp, &nvp, VLKTIMEOUT, 0);
289 	if (error) {
290 		*depp = NULL;
291 		kfree(ldep, M_MSDOSFSNODE);
292 		return error;
293 	}
294 
295 	ldep->de_vnode = nvp;
296 	ldep->de_flag = 0;
297 	ldep->de_devvp = 0;
298 	ldep->de_dev = dev;
299 	ldep->de_dirclust = dirclust;
300 	ldep->de_diroffset = diroffset;
301 	fc_purge(ldep, 0);	/* init the fat cache for this denode */
302 
303 	/*
304 	 * Insert the denode into the hash queue.  If a collision occurs
305 	 * throw away the vnode and try again.
306 	 */
307 	error = msdosfs_hashins(ldep);
308 	if (error == EBUSY) {
309 		nvp->v_type = VBAD;
310 		vx_put(nvp);
311 		kfree(ldep, M_MSDOSFSNODE);
312 		goto again;
313 	} else if (error) {
314 		nvp->v_type = VBAD;
315 		vx_put(nvp);
316 		kfree(ldep, M_MSDOSFSNODE);
317 		*depp = NULL;
318 		return (EINVAL);
319 	}
320 	nvp->v_data = ldep;
321 	ldep->de_pmp = pmp;
322 	ldep->de_refcnt = 1;
323 	/*
324 	 * Copy the directory entry into the denode area of the vnode.
325 	 */
326 	if ((dirclust == MSDOSFSROOT
327 	     || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
328 	    && diroffset == MSDOSFSROOT_OFS) {
329 		/*
330 		 * Directory entry for the root directory. There isn't one,
331 		 * so we manufacture one. We should probably rummage
332 		 * through the root directory and find a label entry (if it
333 		 * exists), and then use the time and date from that entry
334 		 * as the time and date for the root denode.
335 		 */
336 		vsetflags(nvp, VROOT); /* should be further down XXX */
337 
338 		ldep->de_Attributes = ATTR_DIRECTORY;
339 		ldep->de_LowerCase = 0;
340 		if (FAT32(pmp)) {
341 			ldep->de_StartCluster = pmp->pm_rootdirblk;
342 			/* de_FileSize will be filled in further down */
343 		} else {
344 			ldep->de_StartCluster = MSDOSFSROOT;
345 			ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE;
346 		}
347 		/*
348 		 * fill in time and date so that fattime2timespec() doesn't
349 		 * spit up when called from msdosfs_getattr() with root
350 		 * denode
351 		 */
352 		ldep->de_CHun = 0;
353 		ldep->de_CTime = 0x0000;	/* 00:00:00	 */
354 		ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
355 		    | (1 << DD_DAY_SHIFT);
356 		/* Jan 1, 1980	 */
357 		ldep->de_ADate = ldep->de_CDate;
358 		ldep->de_MTime = ldep->de_CTime;
359 		ldep->de_MDate = ldep->de_CDate;
360 		/* leave the other fields as garbage */
361 	} else {
362 		error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
363 		if (error) {
364 			/*
365 			 * The denode does not contain anything useful, so
366 			 * it would be wrong to leave it on its hash chain.
367 			 * Arrange for vput() to just forget about it.
368 			 */
369 			ldep->de_Name[0] = SLOT_DELETED;
370 			nvp->v_type = VBAD;
371 
372 			vx_put(nvp);
373 			*depp = NULL;
374 			return (error);
375 		}
376 		DE_INTERNALIZE(ldep, direntptr);
377 		brelse(bp);
378 	}
379 
380 	/*
381 	 * Fill in a few fields of the vnode and finish filling in the
382 	 * denode.  Then return the address of the found denode.
383 	 */
384 	if (ldep->de_Attributes & ATTR_DIRECTORY) {
385 		/*
386 		 * Since DOS directory entries that describe directories
387 		 * have 0 in the filesize field, we take this opportunity
388 		 * to find out the length of the directory and plug it into
389 		 * the denode structure.
390 		 */
391 		u_long size;
392 
393 		/*
394 		 * XXX it sometimes happens that the "." entry has cluster
395 		 * number 0 when it shouldn't.  Use the actual cluster number
396 		 * instead of what is written in directory entry.
397 		 */
398 		if (diroffset == 0 && ldep->de_StartCluster != dirclust) {
399 			kprintf("deget(): \".\" entry at clust %lu != %lu\n",
400 			    dirclust, ldep->de_StartCluster);
401 			ldep->de_StartCluster = dirclust;
402 		}
403 
404 		nvp->v_type = VDIR;
405 		if (ldep->de_StartCluster != MSDOSFSROOT) {
406 			error = pcbmap(ldep, 0xffff, NULL, &size, NULL);
407 			if (error == E2BIG) {
408 				ldep->de_FileSize = de_cn2off(pmp, size);
409 				error = 0;
410 			} else
411 				kprintf("deget(): pcbmap returned %d\n", error);
412 		}
413 	} else {
414 		nvp->v_type = VREG;
415 	}
416 
417 	ldep->de_modrev = init_va_filerev();
418 	ldep->de_devvp = pmp->pm_devvp;
419 	vref(ldep->de_devvp);
420 	vinitvmio(nvp, ldep->de_FileSize, PAGE_SIZE, -1);
421 	/*
422 	 * Leave nvp locked and refd so the returned inode is effectively
423 	 * locked and refd.
424 	 */
425 	*depp = ldep;
426 	return (0);
427 }
428 
429 int
430 deupdat(struct denode *dep, int waitfor)
431 {
432 	int error;
433 	struct buf *bp;
434 	struct direntry *dirp;
435 	struct timespec ts;
436 
437 	if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY)
438 		return (0);
439 	vfs_timestamp(&ts);
440 	DETIMES(dep, &ts, &ts, &ts);
441 	if ((dep->de_flag & DE_MODIFIED) == 0)
442 		return (0);
443 	dep->de_flag &= ~DE_MODIFIED;
444 	if (dep->de_Attributes & ATTR_DIRECTORY)
445 		return (0);
446 	if (dep->de_refcnt <= 0)
447 		return (0);
448 	error = readde(dep, &bp, &dirp);
449 	if (error)
450 		return (error);
451 	DE_EXTERNALIZE(dirp, dep);
452 	if (waitfor) {
453 		return (bwrite(bp));
454 	} else {
455 		bdwrite(bp);
456 		return (0);
457 	}
458 }
459 
460 /*
461  * Truncate the file described by dep to the length specified by length.
462  */
463 int
464 detrunc(struct denode *dep, u_long length, int flags)
465 {
466 	int error;
467 	int allerror;
468 	u_long eofentry;
469 	u_long chaintofree;
470 	daddr_t bn, cn;
471 	int boff;
472 	int isadir = dep->de_Attributes & ATTR_DIRECTORY;
473 	struct buf *bp;
474 	struct msdosfsmount *pmp = dep->de_pmp;
475 
476 	mprintf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name,
477 		length, flags);
478 
479 	/*
480 	 * Disallow attempts to truncate the root directory since it is of
481 	 * fixed size.  That's just the way dos filesystems are.  We use
482 	 * the VROOT bit in the vnode because checking for the directory
483 	 * bit and a startcluster of 0 in the denode is not adequate to
484 	 * recognize the root directory at this point in a file or
485 	 * directory's life.
486 	 */
487 	if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) {
488 		kprintf("detrunc(): can't truncate root directory, clust %ld, "
489 			"offset %ld\n",
490 			dep->de_dirclust, dep->de_diroffset);
491 		return (EINVAL);
492 	}
493 
494 	if (dep->de_FileSize < length) {
495 		vnode_pager_setsize(DETOV(dep), length);
496 		return deextend(dep, length);
497 	}
498 
499 	/*
500 	 * If the desired length is 0 then remember the starting cluster of
501 	 * the file and set the StartCluster field in the directory entry
502 	 * to 0.  If the desired length is not zero, then get the number of
503 	 * the last cluster in the shortened file.  Then get the number of
504 	 * the first cluster in the part of the file that is to be freed.
505 	 * Then set the next cluster pointer in the last cluster of the
506 	 * file to CLUST_EOFE.
507 	 */
508 	if (length == 0) {
509 		chaintofree = dep->de_StartCluster;
510 		dep->de_StartCluster = 0;
511 		eofentry = ~0;
512 	} else {
513 		error = pcbmap(dep, de_clcount(pmp, length) - 1,
514 			       NULL, &eofentry, NULL);
515 		if (error) {
516 			mprintf("detrunc(): pcbmap fails %d\n", error);
517 			return (error);
518 		}
519 	}
520 
521 	fc_purge(dep, de_clcount(pmp, length));
522 
523 	/*
524 	 * If the new length is not a multiple of the cluster size then we
525 	 * must zero the tail end of the new last cluster in case it
526 	 * becomes part of the file again because of a seek.
527 	 */
528 	if ((boff = length & pmp->pm_crbomask) != 0) {
529 		if (isadir) {
530 			bn = cntobn(pmp, eofentry);
531 			error = bread(pmp->pm_devvp, de_bn2doff(pmp, bn),
532 				      pmp->pm_bpcluster, &bp);
533 		} else {
534 			cn = de_cluster(pmp, length);
535 			error = bread(DETOV(dep), de_cn2doff(pmp, cn),
536 				      pmp->pm_bpcluster, &bp);
537 		}
538 		if (error) {
539 			brelse(bp);
540 			mprintf("detrunc(): bread fails %d\n", error);
541 			return (error);
542 		}
543 		memset(bp->b_data + boff, 0, pmp->pm_bpcluster - boff);
544 		if ((flags & IO_SYNC) != 0)
545 			bwrite(bp);
546 		else
547 			bdwrite(bp);
548 	}
549 
550 	/*
551 	 * Write out the updated directory entry.  Even if the update fails
552 	 * we free the trailing clusters.
553 	 */
554 	dep->de_FileSize = length;
555 	if (!isadir)
556 		dep->de_flag |= DE_UPDATE | DE_MODIFIED;
557 	allerror = vtruncbuf(DETOV(dep), length, pmp->pm_bpcluster);
558 #ifdef MSDOSFS_DEBUG
559 	if (allerror)
560 		kprintf("detrunc(): vtruncbuf error %d\n", allerror);
561 #endif
562 	error = deupdat(dep, 1);
563 	if (error != 0 && allerror == 0)
564 		allerror = error;
565 	mprintf("detrunc(): allerror %d, eofentry %lu\n",
566 		allerror, eofentry);
567 
568 	/*
569 	 * If we need to break the cluster chain for the file then do it
570 	 * now.
571 	 */
572 	if (eofentry != ~0) {
573 		error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
574 				 &chaintofree, CLUST_EOFE);
575 		if (error) {
576 			mprintf("detrunc(): fatentry errors %d\n", error);
577 			return (error);
578 		}
579 		fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
580 			    eofentry);
581 	}
582 
583 	/*
584 	 * Now free the clusters removed from the file because of the
585 	 * truncation.
586 	 */
587 	if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
588 		freeclusterchain(pmp, chaintofree);
589 
590 	return (allerror);
591 }
592 
593 /*
594  * Extend the file described by dep to length specified by length.
595  */
596 int
597 deextend(struct denode *dep, u_long length)
598 {
599 	struct msdosfsmount *pmp = dep->de_pmp;
600 	u_long count;
601 	int error;
602 
603 	/*
604 	 * The root of a DOS filesystem cannot be extended.
605 	 */
606 	if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp))
607 		return (EINVAL);
608 
609 	/*
610 	 * Directories cannot be extended.
611 	 */
612 	if (dep->de_Attributes & ATTR_DIRECTORY)
613 		return (EISDIR);
614 
615 	if (length <= dep->de_FileSize)
616 		panic("deextend: file too large");
617 
618 	/*
619 	 * Compute the number of clusters to allocate.
620 	 */
621 	count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
622 	if (count > 0) {
623 		if (count > pmp->pm_freeclustercount)
624 			return (ENOSPC);
625 		error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
626 		if (error) {
627 			/* truncate the added clusters away again */
628 			detrunc(dep, dep->de_FileSize, 0);
629 			return (error);
630 		}
631 	}
632 	dep->de_FileSize = length;
633 	dep->de_flag |= DE_UPDATE | DE_MODIFIED;
634 	return (deupdat(dep, 1));
635 }
636 
637 int
638 msdosfs_reclaim(struct vop_reclaim_args *ap)
639 {
640 	struct vnode *vp = ap->a_vp;
641 	struct denode *dep = VTODE(vp);
642 
643 	mprintf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
644 	    dep, dep ? (char *)dep->de_Name : "?", dep ? dep->de_refcnt : -1);
645 
646 	if (prtactive && VREFCNT(vp) > 1)
647 		vprint("msdosfs_reclaim(): pushing active", vp);
648 	/*
649 	 * Remove the denode from its hash chain.
650 	 */
651 	vp->v_data = NULL;
652 	if (dep) {
653 		msdosfs_hashrem(dep);
654 		if (dep->de_devvp) {
655 			vrele(dep->de_devvp);
656 			dep->de_devvp = 0;
657 		}
658 		kfree(dep, M_MSDOSFSNODE);
659 	}
660 	return (0);
661 }
662 
663 int
664 msdosfs_inactive(struct vop_inactive_args *ap)
665 {
666 	struct vnode *vp = ap->a_vp;
667 	struct denode *dep = VTODE(vp);
668 	int error = 0;
669 
670 	mprintf("msdosfs_inactive(): dep %p, de_Name[0] %x\n",
671 		dep, (dep ? dep->de_Name[0] : 0));
672 
673 	if (prtactive && VREFCNT(vp) > 1)
674 		vprint("msdosfs_inactive(): pushing active", vp);
675 
676 	/*
677 	 * Ignore denodes related to stale file handles.
678 	 */
679 	if (dep == NULL || dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
680 		goto out;
681 
682 	/*
683 	 * If the file has been deleted and it is on a read/write
684 	 * filesystem, then truncate the file, and mark the directory slot
685 	 * as empty.  (This may not be necessary for the dos filesystem.)
686 	 */
687 	mprintf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n",
688 		dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
689 	if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
690 		error = detrunc(dep, (u_long) 0, 0);
691 		dep->de_flag |= DE_UPDATE;
692 		dep->de_Name[0] = SLOT_DELETED;
693 	}
694 	deupdat(dep, 0);
695 
696 out:
697 	/*
698 	 * If we are done with the denode, reclaim it
699 	 * so that it can be reused immediately.
700 	 */
701 	mprintf("msdosfs_inactive(): v_refcnt 0x%08x, de_Name[0] %x\n",
702 		vp->v_refcnt, (dep ? dep->de_Name[0] : 0));
703 	if (dep == NULL || dep->de_Name[0] == SLOT_DELETED || dep->de_Name[0] == SLOT_EMPTY)
704 		vrecycle(vp);
705 	return (error);
706 }
707