xref: /freebsd/sys/fs/msdosfs/msdosfs_denode.c (revision a3e8fd0b7f663db7eafff527d5c3ca3bcfa8a537)
1 /* $FreeBSD$ */
2 /*	$NetBSD: msdosfs_denode.c,v 1.28 1998/02/10 14:10:00 mrg Exp $	*/
3 
4 /*-
5  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
6  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
7  * All rights reserved.
8  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by TooLs GmbH.
21  * 4. The name of TooLs GmbH may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
30  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
32  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
33  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 /*
36  * Written by Paul Popelka (paulp@uts.amdahl.com)
37  *
38  * You can do anything you want with this software, just don't say you wrote
39  * it, and don't remove this notice.
40  *
41  * This software is provided "as is".
42  *
43  * The author supplies this software to be publicly redistributed on the
44  * understanding that the author is not responsible for the correct
45  * functioning of this software in any circumstances and is not liable for
46  * any damages caused by this software.
47  *
48  * October 1992
49  */
50 
51 #include <sys/param.h>
52 #include <sys/systm.h>
53 #include <sys/kernel.h>
54 #include <sys/mount.h>
55 #include <sys/malloc.h>
56 #include <sys/bio.h>
57 #include <sys/buf.h>
58 #include <sys/vnode.h>
59 #include <sys/mutex.h>
60 
61 #include <vm/vm.h>
62 #include <vm/vm_extern.h>
63 
64 #include <fs/msdosfs/bpb.h>
65 #include <fs/msdosfs/msdosfsmount.h>
66 #include <fs/msdosfs/direntry.h>
67 #include <fs/msdosfs/denode.h>
68 #include <fs/msdosfs/fat.h>
69 
70 static MALLOC_DEFINE(M_MSDOSFSNODE, "MSDOSFS node", "MSDOSFS vnode private part");
71 
72 static struct denode **dehashtbl;
73 static u_long dehash;			/* size of hash table - 1 */
74 #define	DEHASH(dev, dcl, doff)	(dehashtbl[(minor(dev) + (dcl) + (doff) / 	\
75 				sizeof(struct direntry)) & dehash])
76 static struct mtx dehash_mtx;
77 
78 union _qcvt {
79 	quad_t qcvt;
80 	long val[2];
81 };
82 #define SETHIGH(q, h) { \
83 	union _qcvt tmp; \
84 	tmp.qcvt = (q); \
85 	tmp.val[_QUAD_HIGHWORD] = (h); \
86 	(q) = tmp.qcvt; \
87 }
88 #define SETLOW(q, l) { \
89 	union _qcvt tmp; \
90 	tmp.qcvt = (q); \
91 	tmp.val[_QUAD_LOWWORD] = (l); \
92 	(q) = tmp.qcvt; \
93 }
94 
95 static struct denode *
96 		msdosfs_hashget(dev_t dev, u_long dirclust, u_long diroff);
97 static void	msdosfs_hashins(struct denode *dep);
98 static void	msdosfs_hashrem(struct denode *dep);
99 
100 /*ARGSUSED*/
101 int
102 msdosfs_init(vfsp)
103 	struct vfsconf *vfsp;
104 {
105 	dehashtbl = hashinit(desiredvnodes/2, M_MSDOSFSMNT, &dehash);
106 	mtx_init(&dehash_mtx, "msdosfs dehash", NULL, MTX_DEF);
107 	return (0);
108 }
109 
110 int
111 msdosfs_uninit(vfsp)
112 	struct vfsconf *vfsp;
113 {
114 
115 	if (dehashtbl)
116 		free(dehashtbl, M_MSDOSFSMNT);
117 	mtx_destroy(&dehash_mtx);
118 	return (0);
119 }
120 
121 static struct denode *
122 msdosfs_hashget(dev, dirclust, diroff)
123 	dev_t dev;
124 	u_long dirclust;
125 	u_long diroff;
126 {
127 	struct thread *td = curthread;	/* XXX */
128 	struct denode *dep;
129 	struct vnode *vp;
130 
131 loop:
132 	mtx_lock(&dehash_mtx);
133 	for (dep = DEHASH(dev, dirclust, diroff); dep; dep = dep->de_next) {
134 		if (dirclust == dep->de_dirclust
135 		    && diroff == dep->de_diroffset
136 		    && dev == dep->de_dev
137 		    && dep->de_refcnt != 0) {
138 			vp = DETOV(dep);
139 			mtx_lock(&vp->v_interlock);
140 			mtx_unlock(&dehash_mtx);
141 			if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td))
142 				goto loop;
143 			return (dep);
144 		}
145 	}
146 	mtx_unlock(&dehash_mtx);
147 	return (NULL);
148 }
149 
150 static void
151 msdosfs_hashins(dep)
152 	struct denode *dep;
153 {
154 	struct denode **depp, *deq;
155 
156 	mtx_lock(&dehash_mtx);
157 	depp = &DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
158 	deq = *depp;
159 	if (deq)
160 		deq->de_prev = &dep->de_next;
161 	dep->de_next = deq;
162 	dep->de_prev = depp;
163 	*depp = dep;
164 	mtx_unlock(&dehash_mtx);
165 }
166 
167 static void
168 msdosfs_hashrem(dep)
169 	struct denode *dep;
170 {
171 	struct denode *deq;
172 
173 	mtx_lock(&dehash_mtx);
174 	deq = dep->de_next;
175 	if (deq)
176 		deq->de_prev = dep->de_prev;
177 	*dep->de_prev = deq;
178 #ifdef DIAGNOSTIC
179 	dep->de_next = NULL;
180 	dep->de_prev = NULL;
181 #endif
182 	mtx_unlock(&dehash_mtx);
183 }
184 
185 /*
186  * If deget() succeeds it returns with the gotten denode locked().
187  *
188  * pmp	     - address of msdosfsmount structure of the filesystem containing
189  *	       the denode of interest.  The pm_dev field and the address of
190  *	       the msdosfsmount structure are used.
191  * dirclust  - which cluster bp contains, if dirclust is 0 (root directory)
192  *	       diroffset is relative to the beginning of the root directory,
193  *	       otherwise it is cluster relative.
194  * diroffset - offset past begin of cluster of denode we want
195  * depp	     - returns the address of the gotten denode.
196  */
197 int
198 deget(pmp, dirclust, diroffset, depp)
199 	struct msdosfsmount *pmp;	/* so we know the maj/min number */
200 	u_long dirclust;		/* cluster this dir entry came from */
201 	u_long diroffset;		/* index of entry within the cluster */
202 	struct denode **depp;		/* returns the addr of the gotten denode */
203 {
204 	int error;
205 	dev_t dev = pmp->pm_dev;
206 	struct mount *mntp = pmp->pm_mountp;
207 	struct direntry *direntptr;
208 	struct denode *ldep;
209 	struct vnode *nvp;
210 	struct buf *bp;
211 	struct thread *td = curthread;	/* XXX */
212 	struct timeval tv;
213 
214 #ifdef MSDOSFS_DEBUG
215 	printf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n",
216 	    pmp, dirclust, diroffset, depp);
217 #endif
218 
219 	/*
220 	 * On FAT32 filesystems, root is a (more or less) normal
221 	 * directory
222 	 */
223 	if (FAT32(pmp) && dirclust == MSDOSFSROOT)
224 		dirclust = pmp->pm_rootdirblk;
225 
226 	/*
227 	 * See if the denode is in the denode cache. Use the location of
228 	 * the directory entry to compute the hash value. For subdir use
229 	 * address of "." entry. For root dir (if not FAT32) use cluster
230 	 * MSDOSFSROOT, offset MSDOSFSROOT_OFS
231 	 *
232 	 * NOTE: The check for de_refcnt > 0 below insures the denode being
233 	 * examined does not represent an unlinked but still open file.
234 	 * These files are not to be accessible even when the directory
235 	 * entry that represented the file happens to be reused while the
236 	 * deleted file is still open.
237 	 */
238 	ldep = msdosfs_hashget(dev, dirclust, diroffset);
239 	if (ldep) {
240 		*depp = ldep;
241 		return (0);
242 	}
243 
244 	/*
245 	 * Do the MALLOC before the getnewvnode since doing so afterward
246 	 * might cause a bogus v_data pointer to get dereferenced
247 	 * elsewhere if MALLOC should block.
248 	 */
249 	MALLOC(ldep, struct denode *, sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK);
250 
251 	/*
252 	 * Directory entry was not in cache, have to create a vnode and
253 	 * copy it from the passed disk buffer.
254 	 */
255 	/* getnewvnode() does a VREF() on the vnode */
256 	error = getnewvnode("msdosfs", mntp, msdosfs_vnodeop_p, &nvp);
257 	if (error) {
258 		*depp = NULL;
259 		FREE(ldep, M_MSDOSFSNODE);
260 		return error;
261 	}
262 	bzero((caddr_t)ldep, sizeof *ldep);
263 	nvp->v_data = ldep;
264 	ldep->de_vnode = nvp;
265 	ldep->de_flag = 0;
266 	ldep->de_devvp = 0;
267 	ldep->de_dev = dev;
268 	ldep->de_dirclust = dirclust;
269 	ldep->de_diroffset = diroffset;
270 	fc_purge(ldep, 0);	/* init the fat cache for this denode */
271 
272 	/*
273 	 * Lock the denode so that it can't be accessed until we've read
274 	 * it in and have done what we need to it.  Do this here instead
275 	 * of at the start of msdosfs_hashins() so that reinsert() can
276 	 * call msdosfs_hashins() with a locked denode.
277 	 */
278 	if (VOP_LOCK(nvp, LK_EXCLUSIVE, td) != 0)
279 		panic("deget: unexpected lock failure");
280 
281 	/*
282 	 * Insert the denode into the hash queue.
283 	 */
284 	msdosfs_hashins(ldep);
285 
286 	ldep->de_pmp = pmp;
287 	ldep->de_refcnt = 1;
288 	/*
289 	 * Copy the directory entry into the denode area of the vnode.
290 	 */
291 	if ((dirclust == MSDOSFSROOT
292 	     || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
293 	    && diroffset == MSDOSFSROOT_OFS) {
294 		/*
295 		 * Directory entry for the root directory. There isn't one,
296 		 * so we manufacture one. We should probably rummage
297 		 * through the root directory and find a label entry (if it
298 		 * exists), and then use the time and date from that entry
299 		 * as the time and date for the root denode.
300 		 */
301 		nvp->v_vflag |= VV_ROOT; /* should be further down XXX */
302 
303 		ldep->de_Attributes = ATTR_DIRECTORY;
304 		ldep->de_LowerCase = 0;
305 		if (FAT32(pmp))
306 			ldep->de_StartCluster = pmp->pm_rootdirblk;
307 			/* de_FileSize will be filled in further down */
308 		else {
309 			ldep->de_StartCluster = MSDOSFSROOT;
310 			ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE;
311 		}
312 		/*
313 		 * fill in time and date so that dos2unixtime() doesn't
314 		 * spit up when called from msdosfs_getattr() with root
315 		 * denode
316 		 */
317 		ldep->de_CHun = 0;
318 		ldep->de_CTime = 0x0000;	/* 00:00:00	 */
319 		ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
320 		    | (1 << DD_DAY_SHIFT);
321 		/* Jan 1, 1980	 */
322 		ldep->de_ADate = ldep->de_CDate;
323 		ldep->de_MTime = ldep->de_CTime;
324 		ldep->de_MDate = ldep->de_CDate;
325 		/* leave the other fields as garbage */
326 	} else {
327 		error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
328 		if (error) {
329 			/*
330 			 * The denode does not contain anything useful, so
331 			 * it would be wrong to leave it on its hash chain.
332 			 * Arrange for vput() to just forget about it.
333 			 */
334 			ldep->de_Name[0] = SLOT_DELETED;
335 
336 			vput(nvp);
337 			*depp = NULL;
338 			return (error);
339 		}
340 		DE_INTERNALIZE(ldep, direntptr);
341 		brelse(bp);
342 	}
343 
344 	/*
345 	 * Fill in a few fields of the vnode and finish filling in the
346 	 * denode.  Then return the address of the found denode.
347 	 */
348 	if (ldep->de_Attributes & ATTR_DIRECTORY) {
349 		/*
350 		 * Since DOS directory entries that describe directories
351 		 * have 0 in the filesize field, we take this opportunity
352 		 * to find out the length of the directory and plug it into
353 		 * the denode structure.
354 		 */
355 		u_long size;
356 
357 		/*
358 		 * XXX Sometimes, these arrives that . entry have cluster
359 		 * number 0, when it shouldn't.  Use real cluster number
360 		 * instead of what is written in directory entry.
361 		 */
362 		if ((diroffset == 0) && (ldep->de_StartCluster != dirclust)) {
363 			printf("deget(): . entry at clust %ld != %ld\n",
364 					dirclust, ldep->de_StartCluster);
365 			ldep->de_StartCluster = dirclust;
366 		}
367 
368 		nvp->v_type = VDIR;
369 		if (ldep->de_StartCluster != MSDOSFSROOT) {
370 			error = pcbmap(ldep, 0xffff, 0, &size, 0);
371 			if (error == E2BIG) {
372 				ldep->de_FileSize = de_cn2off(pmp, size);
373 				error = 0;
374 			} else
375 				printf("deget(): pcbmap returned %d\n", error);
376 		}
377 	} else
378 		nvp->v_type = VREG;
379 	getmicrouptime(&tv);
380 	SETHIGH(ldep->de_modrev, tv.tv_sec);
381 	SETLOW(ldep->de_modrev, tv.tv_usec * 4294);
382 	ldep->de_devvp = pmp->pm_devvp;
383 	VREF(ldep->de_devvp);
384 	*depp = ldep;
385 	return (0);
386 }
387 
388 int
389 deupdat(dep, waitfor)
390 	struct denode *dep;
391 	int waitfor;
392 {
393 	int error;
394 	struct buf *bp;
395 	struct direntry *dirp;
396 	struct timespec ts;
397 
398 	if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY)
399 		return (0);
400 	getnanotime(&ts);
401 	DETIMES(dep, &ts, &ts, &ts);
402 	if ((dep->de_flag & DE_MODIFIED) == 0)
403 		return (0);
404 	dep->de_flag &= ~DE_MODIFIED;
405 	if (dep->de_Attributes & ATTR_DIRECTORY)
406 		return (0);
407 	if (dep->de_refcnt <= 0)
408 		return (0);
409 	error = readde(dep, &bp, &dirp);
410 	if (error)
411 		return (error);
412 	DE_EXTERNALIZE(dirp, dep);
413 	if (waitfor)
414 		return (bwrite(bp));
415 	else {
416 		bdwrite(bp);
417 		return (0);
418 	}
419 }
420 
421 /*
422  * Truncate the file described by dep to the length specified by length.
423  */
424 int
425 detrunc(dep, length, flags, cred, td)
426 	struct denode *dep;
427 	u_long length;
428 	int flags;
429 	struct ucred *cred;
430 	struct thread *td;
431 {
432 	int error;
433 	int allerror;
434 	u_long eofentry;
435 	u_long chaintofree;
436 	daddr_t bn;
437 	int boff;
438 	int isadir = dep->de_Attributes & ATTR_DIRECTORY;
439 	struct buf *bp;
440 	struct msdosfsmount *pmp = dep->de_pmp;
441 
442 #ifdef MSDOSFS_DEBUG
443 	printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
444 #endif
445 
446 	/*
447 	 * Disallow attempts to truncate the root directory since it is of
448 	 * fixed size.  That's just the way dos filesystems are.  We use
449 	 * the VROOT bit in the vnode because checking for the directory
450 	 * bit and a startcluster of 0 in the denode is not adequate to
451 	 * recognize the root directory at this point in a file or
452 	 * directory's life.
453 	 */
454 	if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) {
455 		printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
456 		    dep->de_dirclust, dep->de_diroffset);
457 		return (EINVAL);
458 	}
459 
460 
461 	if (dep->de_FileSize < length) {
462 		vnode_pager_setsize(DETOV(dep), length);
463 		return deextend(dep, length, cred);
464 	}
465 
466 	/*
467 	 * If the desired length is 0 then remember the starting cluster of
468 	 * the file and set the StartCluster field in the directory entry
469 	 * to 0.  If the desired length is not zero, then get the number of
470 	 * the last cluster in the shortened file.  Then get the number of
471 	 * the first cluster in the part of the file that is to be freed.
472 	 * Then set the next cluster pointer in the last cluster of the
473 	 * file to CLUST_EOFE.
474 	 */
475 	if (length == 0) {
476 		chaintofree = dep->de_StartCluster;
477 		dep->de_StartCluster = 0;
478 		eofentry = ~0;
479 	} else {
480 		error = pcbmap(dep, de_clcount(pmp, length) - 1, 0,
481 			       &eofentry, 0);
482 		if (error) {
483 #ifdef MSDOSFS_DEBUG
484 			printf("detrunc(): pcbmap fails %d\n", error);
485 #endif
486 			return (error);
487 		}
488 	}
489 
490 	fc_purge(dep, de_clcount(pmp, length));
491 
492 	/*
493 	 * If the new length is not a multiple of the cluster size then we
494 	 * must zero the tail end of the new last cluster in case it
495 	 * becomes part of the file again because of a seek.
496 	 */
497 	if ((boff = length & pmp->pm_crbomask) != 0) {
498 		if (isadir) {
499 			bn = cntobn(pmp, eofentry);
500 			error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
501 			    NOCRED, &bp);
502 		} else {
503 			bn = de_blk(pmp, length);
504 			error = bread(DETOV(dep), bn, pmp->pm_bpcluster,
505 			    NOCRED, &bp);
506 		}
507 		if (error) {
508 			brelse(bp);
509 #ifdef MSDOSFS_DEBUG
510 			printf("detrunc(): bread fails %d\n", error);
511 #endif
512 			return (error);
513 		}
514 		/*
515 		 * is this the right place for it?
516 		 */
517 		bzero(bp->b_data + boff, pmp->pm_bpcluster - boff);
518 		if (flags & IO_SYNC)
519 			bwrite(bp);
520 		else
521 			bdwrite(bp);
522 	}
523 
524 	/*
525 	 * Write out the updated directory entry.  Even if the update fails
526 	 * we free the trailing clusters.
527 	 */
528 	dep->de_FileSize = length;
529 	if (!isadir)
530 		dep->de_flag |= DE_UPDATE|DE_MODIFIED;
531 	allerror = vtruncbuf(DETOV(dep), cred, td, length, pmp->pm_bpcluster);
532 #ifdef MSDOSFS_DEBUG
533 	if (allerror)
534 		printf("detrunc(): vtruncbuf error %d\n", allerror);
535 #endif
536 	error = deupdat(dep, 1);
537 	if (error && (allerror == 0))
538 		allerror = error;
539 #ifdef MSDOSFS_DEBUG
540 	printf("detrunc(): allerror %d, eofentry %lu\n",
541 	       allerror, eofentry);
542 #endif
543 
544 	/*
545 	 * If we need to break the cluster chain for the file then do it
546 	 * now.
547 	 */
548 	if (eofentry != ~0) {
549 		error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
550 				 &chaintofree, CLUST_EOFE);
551 		if (error) {
552 #ifdef MSDOSFS_DEBUG
553 			printf("detrunc(): fatentry errors %d\n", error);
554 #endif
555 			return (error);
556 		}
557 		fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
558 			    eofentry);
559 	}
560 
561 	/*
562 	 * Now free the clusters removed from the file because of the
563 	 * truncation.
564 	 */
565 	if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
566 		freeclusterchain(pmp, chaintofree);
567 
568 	return (allerror);
569 }
570 
571 /*
572  * Extend the file described by dep to length specified by length.
573  */
574 int
575 deextend(dep, length, cred)
576 	struct denode *dep;
577 	u_long length;
578 	struct ucred *cred;
579 {
580 	struct msdosfsmount *pmp = dep->de_pmp;
581 	u_long count;
582 	int error;
583 
584 	/*
585 	 * The root of a DOS filesystem cannot be extended.
586 	 */
587 	if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp))
588 		return (EINVAL);
589 
590 	/*
591 	 * Directories cannot be extended.
592 	 */
593 	if (dep->de_Attributes & ATTR_DIRECTORY)
594 		return (EISDIR);
595 
596 	if (length <= dep->de_FileSize)
597 		panic("deextend: file too large");
598 
599 	/*
600 	 * Compute the number of clusters to allocate.
601 	 */
602 	count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
603 	if (count > 0) {
604 		if (count > pmp->pm_freeclustercount)
605 			return (ENOSPC);
606 		error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
607 		if (error) {
608 			/* truncate the added clusters away again */
609 			(void) detrunc(dep, dep->de_FileSize, 0, cred, NULL);
610 			return (error);
611 		}
612 	}
613 	dep->de_FileSize = length;
614 	dep->de_flag |= DE_UPDATE|DE_MODIFIED;
615 	return (deupdat(dep, 1));
616 }
617 
618 /*
619  * Move a denode to its correct hash queue after the file it represents has
620  * been moved to a new directory.
621  */
622 void
623 reinsert(dep)
624 	struct denode *dep;
625 {
626 	/*
627 	 * Fix up the denode cache.  If the denode is for a directory,
628 	 * there is nothing to do since the hash is based on the starting
629 	 * cluster of the directory file and that hasn't changed.  If for a
630 	 * file the hash is based on the location of the directory entry,
631 	 * so we must remove it from the cache and re-enter it with the
632 	 * hash based on the new location of the directory entry.
633 	 */
634 	if (dep->de_Attributes & ATTR_DIRECTORY)
635 		return;
636 	msdosfs_hashrem(dep);
637 	msdosfs_hashins(dep);
638 }
639 
640 int
641 msdosfs_reclaim(ap)
642 	struct vop_reclaim_args /* {
643 		struct vnode *a_vp;
644 	} */ *ap;
645 {
646 	struct vnode *vp = ap->a_vp;
647 	struct denode *dep = VTODE(vp);
648 
649 #ifdef MSDOSFS_DEBUG
650 	printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
651 	    dep, dep->de_Name, dep->de_refcnt);
652 #endif
653 
654 	if (prtactive && vrefcnt(vp) != 0)
655 		vprint("msdosfs_reclaim(): pushing active", vp);
656 	/*
657 	 * Remove the denode from its hash chain.
658 	 */
659 	msdosfs_hashrem(dep);
660 	/*
661 	 * Purge old data structures associated with the denode.
662 	 */
663 	cache_purge(vp);
664 	if (dep->de_devvp) {
665 		vrele(dep->de_devvp);
666 		dep->de_devvp = 0;
667 	}
668 #if 0 /* XXX */
669 	dep->de_flag = 0;
670 #endif
671 	FREE(dep, M_MSDOSFSNODE);
672 	vp->v_data = NULL;
673 
674 	return (0);
675 }
676 
677 int
678 msdosfs_inactive(ap)
679 	struct vop_inactive_args /* {
680 		struct vnode *a_vp;
681 		struct thread *a_td;
682 	} */ *ap;
683 {
684 	struct vnode *vp = ap->a_vp;
685 	struct denode *dep = VTODE(vp);
686 	struct thread *td = ap->a_td;
687 	int error = 0;
688 
689 #ifdef MSDOSFS_DEBUG
690 	printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
691 #endif
692 
693 	if (prtactive && vrefcnt(vp) != 0)
694 		vprint("msdosfs_inactive(): pushing active", vp);
695 
696 	/*
697 	 * Ignore denodes related to stale file handles.
698 	 */
699 	if (dep->de_Name[0] == SLOT_DELETED)
700 		goto out;
701 
702 	/*
703 	 * If the file has been deleted and it is on a read/write
704 	 * filesystem, then truncate the file, and mark the directory slot
705 	 * as empty.  (This may not be necessary for the dos filesystem.)
706 	 */
707 #ifdef MSDOSFS_DEBUG
708 	printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n",
709 	       dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
710 #endif
711 	if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
712 		error = detrunc(dep, (u_long) 0, 0, NOCRED, td);
713 		dep->de_flag |= DE_UPDATE;
714 		dep->de_Name[0] = SLOT_DELETED;
715 	}
716 	deupdat(dep, 0);
717 
718 out:
719 	VOP_UNLOCK(vp, 0, td);
720 	/*
721 	 * If we are done with the denode, reclaim it
722 	 * so that it can be reused immediately.
723 	 */
724 #ifdef MSDOSFS_DEBUG
725 	printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n",
726 	       vrefcnt(vp), dep->de_Name[0]);
727 #endif
728 	if (dep->de_Name[0] == SLOT_DELETED)
729 		vrecycle(vp, NULL, td);
730 	return (error);
731 }
732