xref: /dflybsd-src/sys/vfs/msdosfs/msdosfs_denode.c (revision e7b4468ce80913950cd099c393f3ce6ece6fcb2c)
1 /* $FreeBSD: src/sys/msdosfs/msdosfs_denode.c,v 1.47.2.3 2002/08/22 16:20:15 trhodes Exp $ */
2 /* $DragonFly: src/sys/vfs/msdosfs/msdosfs_denode.c,v 1.34 2007/08/08 00:12:51 swildner Exp $ */
3 /*	$NetBSD: msdosfs_denode.c,v 1.28 1998/02/10 14:10:00 mrg Exp $	*/
4 
5 /*-
6  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
7  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
8  * All rights reserved.
9  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
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  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by TooLs GmbH.
22  * 4. The name of TooLs GmbH may not be used to endorse or promote products
23  *    derived from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
31  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
32  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
33  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
34  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 /*
37  * Written by Paul Popelka (paulp@uts.amdahl.com)
38  *
39  * You can do anything you want with this software, just don't say you wrote
40  * it, and don't remove this notice.
41  *
42  * This software is provided "as is".
43  *
44  * The author supplies this software to be publicly redistributed on the
45  * understanding that the author is not responsible for the correct
46  * functioning of this software in any circumstances and is not liable for
47  * any damages caused by this software.
48  *
49  * October 1992
50  */
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/kernel.h>
55 #include <sys/mount.h>
56 #include <sys/malloc.h>
57 #include <sys/proc.h>
58 #include <sys/buf.h>
59 #include <sys/vnode.h>
60 
61 #include <vm/vm.h>
62 #include <vm/vm_extern.h>
63 
64 #include "bpb.h"
65 #include "msdosfsmount.h"
66 #include "direntry.h"
67 #include "denode.h"
68 #include "fat.h"
69 
70 static int msdosfs_hashins (struct denode *dep);
71 static void msdosfs_hashrem (struct denode *dep);
72 
73 static MALLOC_DEFINE(M_MSDOSFSNODE, "MSDOSFS node", "MSDOSFS vnode private part");
74 
75 static struct denode **dehashtbl;
76 static u_long dehash;			/* size of hash table - 1 */
77 #define	DEHASH(dev, dcl, doff)	(dehashtbl[(minor(dev) + (dcl) + (doff) / 	\
78 				sizeof(struct direntry)) & dehash])
79 static struct lwkt_token dehash_token;
80 
81 union _qcvt {
82 	quad_t qcvt;
83 	long val[2];
84 };
85 #define SETHIGH(q, h) { \
86 	union _qcvt tmp; \
87 	tmp.qcvt = (q); \
88 	tmp.val[_QUAD_HIGHWORD] = (h); \
89 	(q) = tmp.qcvt; \
90 }
91 #define SETLOW(q, l) { \
92 	union _qcvt tmp; \
93 	tmp.qcvt = (q); \
94 	tmp.val[_QUAD_LOWWORD] = (l); \
95 	(q) = tmp.qcvt; \
96 }
97 
98 static struct denode *
99 		msdosfs_hashget (cdev_t dev, u_long dirclust, u_long diroff);
100 
101 /*ARGSUSED*/
102 int
103 msdosfs_init(struct vfsconf *vfsp)
104 {
105 	dehash = 16;
106 	while (dehash < desiredvnodes)
107 		dehash <<= 1;
108 	dehashtbl = kmalloc(sizeof(void *) * dehash, M_MSDOSFSMNT,
109 			   M_WAITOK|M_ZERO);
110 	--dehash;
111 	lwkt_token_init(&dehash_token);
112 	return (0);
113 }
114 
115 int
116 msdosfs_uninit(struct vfsconf *vfsp)
117 {
118 
119 	if (dehashtbl)
120 		kfree(dehashtbl, M_MSDOSFSMNT);
121 	return (0);
122 }
123 
124 static struct denode *
125 msdosfs_hashget(cdev_t dev, u_long dirclust, u_long diroff)
126 {
127 	struct denode *dep;
128 	lwkt_tokref ilock;
129 	struct vnode *vp;
130 
131 	lwkt_gettoken(&ilock, &dehash_token);
132 loop:
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 			continue;
139 		}
140 		vp = DETOV(dep);
141 		if (vget(vp, LK_EXCLUSIVE))
142 			goto loop;
143 
144 		/*
145 		 * We must check to see if the inode has been ripped
146 		 * out from under us after blocking.
147 		 */
148 		for (dep = DEHASH(dev, dirclust, diroff); dep; dep = dep->de_next) {
149 			if (dirclust == dep->de_dirclust
150 			    && diroff == dep->de_diroffset
151 			    && dev == dep->de_dev
152 			    && dep->de_refcnt != 0) {
153 				break;
154 			}
155 		}
156 		if (dep == NULL || DETOV(dep) != vp) {
157 			vput(vp);
158 			goto loop;
159 		}
160 		lwkt_reltoken(&ilock);
161 		return (dep);
162 	}
163 	lwkt_reltoken(&ilock);
164 	return (NULL);
165 }
166 
167 static
168 int
169 msdosfs_hashins(struct denode *dep)
170 {
171 	struct denode **depp, *deq;
172 	lwkt_tokref ilock;
173 
174 	lwkt_gettoken(&ilock, &dehash_token);
175 	depp = &DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
176 	while ((deq = *depp) != NULL) {
177 		if (deq->de_dev == dep->de_dev &&
178 		    deq->de_dirclust == dep->de_dirclust &&
179 		    deq->de_diroffset == dep->de_diroffset) {
180 			lwkt_reltoken(&ilock);
181 			if (dep->de_refcnt)
182 				return(EBUSY);
183 			else
184 				return(EINVAL);
185 		}
186 		depp = &deq->de_next;
187 	}
188 	dep->de_next = NULL;
189 	*depp = dep;
190 	lwkt_reltoken(&ilock);
191 	return(0);
192 }
193 
194 static
195 void
196 msdosfs_hashrem(struct denode *dep)
197 {
198 	struct denode **depp, *deq;
199 	lwkt_tokref ilock;
200 
201 	lwkt_gettoken(&ilock, &dehash_token);
202 	depp = &DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
203 	while ((deq = *depp) != NULL) {
204 		if (dep == deq)
205 			break;
206 		depp = &deq->de_next;
207 	}
208 	KKASSERT(dep == deq);
209 	*depp = dep->de_next;
210 	dep->de_next = NULL;
211 	lwkt_reltoken(&ilock);
212 }
213 
214 void
215 msdosfs_reinsert(struct denode *ip, u_long new_dirclust, u_long new_diroffset)
216 {
217 	lwkt_tokref ilock;
218 
219 	lwkt_gettoken(&ilock, &dehash_token);
220 	msdosfs_hashrem(ip);
221 	ip->de_dirclust = new_dirclust;
222 	ip->de_diroffset = new_diroffset;
223 	msdosfs_hashins(ip);
224 	lwkt_reltoken(&ilock);
225 }
226 
227 /*
228  * If deget() succeeds it returns with the gotten denode locked().
229  *
230  * pmp	     - address of msdosfsmount structure of the filesystem containing
231  *	       the denode of interest.  The pm_dev field and the address of
232  *	       the msdosfsmount structure are used.
233  * dirclust  - which cluster bp contains, if dirclust is 0 (root directory)
234  *	       diroffset is relative to the beginning of the root directory,
235  *	       otherwise it is cluster relative.
236  * diroffset - offset past begin of cluster of denode we want
237  * depp	     - returns the address of the gotten denode.
238  */
239 int
240 deget(struct msdosfsmount *pmp,	/* so we know the maj/min number */
241       u_long dirclust,		/* cluster this dir entry came from */
242       u_long diroffset,		/* index of entry within the cluster */
243       struct denode **depp)	/* returns the addr of the gotten denode */
244 {
245 	int error;
246 	cdev_t dev = pmp->pm_dev;
247 	struct mount *mntp = pmp->pm_mountp;
248 	struct direntry *direntptr;
249 	struct denode *ldep;
250 	struct vnode *nvp;
251 	struct buf *bp;
252 	struct timeval tv;
253 
254 #ifdef MSDOSFS_DEBUG
255 	kprintf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n",
256 	    pmp, dirclust, diroffset, depp);
257 #endif
258 
259 	/*
260 	 * On FAT32 filesystems, root is a (more or less) normal
261 	 * directory
262 	 */
263 	if (FAT32(pmp) && dirclust == MSDOSFSROOT)
264 		dirclust = pmp->pm_rootdirblk;
265 
266 again:
267 	/*
268 	 * See if the denode is in the denode cache. Use the location of
269 	 * the directory entry to compute the hash value. For subdir use
270 	 * address of "." entry. For root dir (if not FAT32) use cluster
271 	 * MSDOSFSROOT, offset MSDOSFSROOT_OFS
272 	 *
273 	 * NOTE: The check for de_refcnt > 0 below insures the denode being
274 	 * examined does not represent an unlinked but still open file.
275 	 * These files are not to be accessible even when the directory
276 	 * entry that represented the file happens to be reused while the
277 	 * deleted file is still open.
278 	 */
279 	ldep = msdosfs_hashget(dev, dirclust, diroffset);
280 	if (ldep) {
281 		*depp = ldep;
282 		return (0);
283 	}
284 
285 	/*
286 	 * Do the MALLOC before the getnewvnode since doing so afterward
287 	 * might cause a bogus v_data pointer to get dereferenced
288 	 * elsewhere if MALLOC should block.
289 	 */
290 	MALLOC(ldep, struct denode *, sizeof(struct denode), M_MSDOSFSNODE, M_WAITOK);
291 
292 	/*
293 	 * Directory entry was not in cache, have to create a vnode and
294 	 * copy it from the passed disk buffer.
295 	 */
296 
297 	/* getnewvnode() does a vref() on the vnode */
298 	error = getnewvnode(VT_MSDOSFS, mntp, &nvp, VLKTIMEOUT, 0);
299 	if (error) {
300 		*depp = NULL;
301 		FREE(ldep, M_MSDOSFSNODE);
302 		return error;
303 	}
304 
305 	bzero((caddr_t)ldep, sizeof *ldep);
306 	ldep->de_vnode = nvp;
307 	ldep->de_flag = 0;
308 	ldep->de_devvp = 0;
309 	ldep->de_dev = dev;
310 	ldep->de_dirclust = dirclust;
311 	ldep->de_diroffset = diroffset;
312 	fc_purge(ldep, 0);	/* init the fat cache for this denode */
313 
314 	/*
315 	 * Insert the denode into the hash queue.  If a collision occurs
316 	 * throw away the vnode and try again.
317 	 */
318 	error = msdosfs_hashins(ldep);
319 	if (error == EBUSY) {
320 		nvp->v_type = VBAD;
321 		vx_put(nvp);
322 		kfree(ldep, M_MSDOSFSNODE);
323 		goto again;
324 	} else if (error) {
325 		nvp->v_type = VBAD;
326 		vx_put(nvp);
327 		kfree(ldep, M_MSDOSFSNODE);
328 		return (EINVAL);
329 	}
330 	nvp->v_data = ldep;
331 	ldep->de_pmp = pmp;
332 	ldep->de_refcnt = 1;
333 	/*
334 	 * Copy the directory entry into the denode area of the vnode.
335 	 */
336 	if ((dirclust == MSDOSFSROOT
337 	     || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
338 	    && diroffset == MSDOSFSROOT_OFS) {
339 		/*
340 		 * Directory entry for the root directory. There isn't one,
341 		 * so we manufacture one. We should probably rummage
342 		 * through the root directory and find a label entry (if it
343 		 * exists), and then use the time and date from that entry
344 		 * as the time and date for the root denode.
345 		 */
346 		nvp->v_flag |= VROOT; /* should be further down		XXX */
347 
348 		ldep->de_Attributes = ATTR_DIRECTORY;
349 		ldep->de_LowerCase = 0;
350 		if (FAT32(pmp))
351 			ldep->de_StartCluster = pmp->pm_rootdirblk;
352 			/* de_FileSize will be filled in further down */
353 		else {
354 			ldep->de_StartCluster = MSDOSFSROOT;
355 			ldep->de_FileSize = pmp->pm_rootdirsize * DEV_BSIZE;
356 		}
357 		/*
358 		 * fill in time and date so that dos2unixtime() doesn't
359 		 * spit up when called from msdosfs_getattr() with root
360 		 * denode
361 		 */
362 		ldep->de_CHun = 0;
363 		ldep->de_CTime = 0x0000;	/* 00:00:00	 */
364 		ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
365 		    | (1 << DD_DAY_SHIFT);
366 		/* Jan 1, 1980	 */
367 		ldep->de_ADate = ldep->de_CDate;
368 		ldep->de_MTime = ldep->de_CTime;
369 		ldep->de_MDate = ldep->de_CDate;
370 		/* leave the other fields as garbage */
371 	} else {
372 		error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
373 		if (error) {
374 			/*
375 			 * The denode does not contain anything useful, so
376 			 * it would be wrong to leave it on its hash chain.
377 			 * Arrange for vput() to just forget about it.
378 			 */
379 			ldep->de_Name[0] = SLOT_DELETED;
380 			nvp->v_type = VBAD;
381 
382 			vx_put(nvp);
383 			*depp = NULL;
384 			return (error);
385 		}
386 		DE_INTERNALIZE(ldep, direntptr);
387 		brelse(bp);
388 	}
389 
390 	/*
391 	 * Fill in a few fields of the vnode and finish filling in the
392 	 * denode.  Then return the address of the found denode.
393 	 */
394 	if (ldep->de_Attributes & ATTR_DIRECTORY) {
395 		/*
396 		 * Since DOS directory entries that describe directories
397 		 * have 0 in the filesize field, we take this opportunity
398 		 * to find out the length of the directory and plug it into
399 		 * the denode structure.
400 		 */
401 		u_long size;
402 
403 		/*
404 		 * XXX Sometimes, these arrives that . entry have cluster
405 		 * number 0, when it shouldn't.  Use real cluster number
406 		 * instead of what is written in directory entry.
407 		 */
408 		if ((diroffset == 0) && (ldep->de_StartCluster != dirclust)) {
409 			kprintf("deget(): . entry at clust %ld != %ld\n",
410 					dirclust, ldep->de_StartCluster);
411 			ldep->de_StartCluster = dirclust;
412 		}
413 
414 		nvp->v_type = VDIR;
415 		if (ldep->de_StartCluster != MSDOSFSROOT) {
416 			error = pcbmap(ldep, 0xffff, NULL, &size, NULL);
417 			if (error == E2BIG) {
418 				ldep->de_FileSize = de_cn2off(pmp, size);
419 				error = 0;
420 			} else
421 				kprintf("deget(): pcbmap returned %d\n", error);
422 		}
423 	} else {
424 		nvp->v_type = VREG;
425 	}
426 	getmicrouptime(&tv);
427 	SETHIGH(ldep->de_modrev, tv.tv_sec);
428 	SETLOW(ldep->de_modrev, tv.tv_usec * 4294);
429 	ldep->de_devvp = pmp->pm_devvp;
430 	vref(ldep->de_devvp);
431 	vinitvmio(nvp, ldep->de_FileSize);
432 	/*
433 	 * Leave nvp locked and refd so the returned inode is effectively
434 	 * locked and refd.
435 	 */
436 	*depp = ldep;
437 	return (0);
438 }
439 
440 int
441 deupdat(struct denode *dep, int waitfor)
442 {
443 	int error;
444 	struct buf *bp;
445 	struct direntry *dirp;
446 	struct timespec ts;
447 
448 	if (DETOV(dep)->v_mount->mnt_flag & MNT_RDONLY)
449 		return (0);
450 	getnanotime(&ts);
451 	DETIMES(dep, &ts, &ts, &ts);
452 	if ((dep->de_flag & DE_MODIFIED) == 0)
453 		return (0);
454 	dep->de_flag &= ~DE_MODIFIED;
455 	if (dep->de_Attributes & ATTR_DIRECTORY)
456 		return (0);
457 	if (dep->de_refcnt <= 0)
458 		return (0);
459 	error = readde(dep, &bp, &dirp);
460 	if (error)
461 		return (error);
462 	DE_EXTERNALIZE(dirp, dep);
463 	if (waitfor)
464 		return (bwrite(bp));
465 	else {
466 		bdwrite(bp);
467 		return (0);
468 	}
469 }
470 
471 /*
472  * Truncate the file described by dep to the length specified by length.
473  */
474 int
475 detrunc(struct denode *dep, u_long length, int flags)
476 {
477 	int error;
478 	int allerror;
479 	u_long eofentry;
480 	u_long chaintofree;
481 	daddr_t bn, cn;
482 	int boff;
483 	int isadir = dep->de_Attributes & ATTR_DIRECTORY;
484 	struct buf *bp;
485 	struct msdosfsmount *pmp = dep->de_pmp;
486 
487 #ifdef MSDOSFS_DEBUG
488 	kprintf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
489 #endif
490 
491 	/*
492 	 * Disallow attempts to truncate the root directory since it is of
493 	 * fixed size.  That's just the way dos filesystems are.  We use
494 	 * the VROOT bit in the vnode because checking for the directory
495 	 * bit and a startcluster of 0 in the denode is not adequate to
496 	 * recognize the root directory at this point in a file or
497 	 * directory's life.
498 	 */
499 	if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp)) {
500 		kprintf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
501 		    dep->de_dirclust, dep->de_diroffset);
502 		return (EINVAL);
503 	}
504 
505 
506 	if (dep->de_FileSize < length) {
507 		vnode_pager_setsize(DETOV(dep), length);
508 		return deextend(dep, length);
509 	}
510 
511 	/*
512 	 * If the desired length is 0 then remember the starting cluster of
513 	 * the file and set the StartCluster field in the directory entry
514 	 * to 0.  If the desired length is not zero, then get the number of
515 	 * the last cluster in the shortened file.  Then get the number of
516 	 * the first cluster in the part of the file that is to be freed.
517 	 * Then set the next cluster pointer in the last cluster of the
518 	 * file to CLUST_EOFE.
519 	 */
520 	if (length == 0) {
521 		chaintofree = dep->de_StartCluster;
522 		dep->de_StartCluster = 0;
523 		eofentry = ~0;
524 	} else {
525 		error = pcbmap(dep, de_clcount(pmp, length) - 1,
526 			       NULL, &eofentry, NULL);
527 		if (error) {
528 #ifdef MSDOSFS_DEBUG
529 			kprintf("detrunc(): pcbmap fails %d\n", error);
530 #endif
531 			return (error);
532 		}
533 	}
534 
535 	fc_purge(dep, de_clcount(pmp, length));
536 
537 	/*
538 	 * If the new length is not a multiple of the cluster size then we
539 	 * must zero the tail end of the new last cluster in case it
540 	 * becomes part of the file again because of a seek.
541 	 */
542 	if ((boff = length & pmp->pm_crbomask) != 0) {
543 		if (isadir) {
544 			bn = xcntobn(pmp, eofentry);
545 			error = bread(pmp->pm_devvp, de_bntodoff(pmp, bn), pmp->pm_bpcluster, &bp);
546 		} else {
547 			cn = de_cluster(pmp, length);
548 			error = bread(DETOV(dep), de_cn2doff(pmp, cn), pmp->pm_bpcluster, &bp);
549 		}
550 		if (error) {
551 			brelse(bp);
552 #ifdef MSDOSFS_DEBUG
553 			kprintf("detrunc(): bread fails %d\n", error);
554 #endif
555 			return (error);
556 		}
557 		/*
558 		 * is this the right place for it?
559 		 */
560 		bzero(bp->b_data + boff, pmp->pm_bpcluster - boff);
561 		if (flags & IO_SYNC)
562 			bwrite(bp);
563 		else
564 			bdwrite(bp);
565 	}
566 
567 	/*
568 	 * Write out the updated directory entry.  Even if the update fails
569 	 * we free the trailing clusters.
570 	 */
571 	dep->de_FileSize = length;
572 	if (!isadir)
573 		dep->de_flag |= DE_UPDATE|DE_MODIFIED;
574 	allerror = vtruncbuf(DETOV(dep), length, pmp->pm_bpcluster);
575 #ifdef MSDOSFS_DEBUG
576 	if (allerror)
577 		kprintf("detrunc(): vtruncbuf error %d\n", allerror);
578 #endif
579 	error = deupdat(dep, 1);
580 	if (error && (allerror == 0))
581 		allerror = error;
582 #ifdef MSDOSFS_DEBUG
583 	kprintf("detrunc(): allerror %d, eofentry %lu\n",
584 	       allerror, eofentry);
585 #endif
586 
587 	/*
588 	 * If we need to break the cluster chain for the file then do it
589 	 * now.
590 	 */
591 	if (eofentry != ~0) {
592 		error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
593 				 &chaintofree, CLUST_EOFE);
594 		if (error) {
595 #ifdef MSDOSFS_DEBUG
596 			kprintf("detrunc(): fatentry errors %d\n", error);
597 #endif
598 			return (error);
599 		}
600 		fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
601 			    eofentry);
602 	}
603 
604 	/*
605 	 * Now free the clusters removed from the file because of the
606 	 * truncation.
607 	 */
608 	if (chaintofree != 0 && !MSDOSFSEOF(pmp, chaintofree))
609 		freeclusterchain(pmp, chaintofree);
610 
611 	return (allerror);
612 }
613 
614 /*
615  * Extend the file described by dep to length specified by length.
616  */
617 int
618 deextend(struct denode *dep, u_long length)
619 {
620 	struct msdosfsmount *pmp = dep->de_pmp;
621 	u_long count;
622 	int error;
623 
624 	/*
625 	 * The root of a DOS filesystem cannot be extended.
626 	 */
627 	if ((DETOV(dep)->v_flag & VROOT) && !FAT32(pmp))
628 		return (EINVAL);
629 
630 	/*
631 	 * Directories cannot be extended.
632 	 */
633 	if (dep->de_Attributes & ATTR_DIRECTORY)
634 		return (EISDIR);
635 
636 	if (length <= dep->de_FileSize)
637 		panic("deextend: file too large");
638 
639 	/*
640 	 * Compute the number of clusters to allocate.
641 	 */
642 	count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
643 	if (count > 0) {
644 		if (count > pmp->pm_freeclustercount)
645 			return (ENOSPC);
646 		error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
647 		if (error) {
648 			/* truncate the added clusters away again */
649 			detrunc(dep, dep->de_FileSize, 0);
650 			return (error);
651 		}
652 	}
653 	dep->de_FileSize = length;
654 	dep->de_flag |= DE_UPDATE|DE_MODIFIED;
655 	return (deupdat(dep, 1));
656 }
657 
658 /*
659  * msdosfs_reclaim(struct vnode *a_vp)
660  */
661 int
662 msdosfs_reclaim(struct vop_reclaim_args *ap)
663 {
664 	struct vnode *vp = ap->a_vp;
665 	struct denode *dep = VTODE(vp);
666 
667 #ifdef MSDOSFS_DEBUG
668 	kprintf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
669 	    dep, dep ? (char *)dep->de_Name : "?", dep ? dep->de_refcnt : -1);
670 #endif
671 
672 	if (prtactive && vp->v_sysref.refcnt > 1)
673 		vprint("msdosfs_reclaim(): pushing active", vp);
674 	/*
675 	 * Remove the denode from its hash chain.
676 	 */
677 	vp->v_data = NULL;
678 	if (dep) {
679 		msdosfs_hashrem(dep);
680 		if (dep->de_devvp) {
681 			vrele(dep->de_devvp);
682 			dep->de_devvp = 0;
683 		}
684 		kfree(dep, M_MSDOSFSNODE);
685 	}
686 	return (0);
687 }
688 
689 /*
690  * msdosfs_inactive(struct vnode *a_vp)
691  */
692 int
693 msdosfs_inactive(struct vop_inactive_args *ap)
694 {
695 	struct vnode *vp = ap->a_vp;
696 	struct denode *dep = VTODE(vp);
697 	int error = 0;
698 
699 #ifdef MSDOSFS_DEBUG
700 	kprintf("msdosfs_inactive(): dep %p, de_Name[0] %x\n",
701 		dep, (dep ? dep->de_Name[0] : 0));
702 #endif
703 
704 	if (prtactive && vp->v_sysref.refcnt > 1)
705 		vprint("msdosfs_inactive(): pushing active", vp);
706 
707 	/*
708 	 * Ignore denodes related to stale file handles.
709 	 */
710 	if (dep == NULL || dep->de_Name[0] == SLOT_DELETED)
711 		goto out;
712 
713 	/*
714 	 * If the file has been deleted and it is on a read/write
715 	 * filesystem, then truncate the file, and mark the directory slot
716 	 * as empty.  (This may not be necessary for the dos filesystem.)
717 	 */
718 #ifdef MSDOSFS_DEBUG
719 	kprintf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x, MNT_RDONLY %x\n",
720 	       dep, dep->de_refcnt, vp->v_mount->mnt_flag, MNT_RDONLY);
721 #endif
722 	if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
723 		error = detrunc(dep, (u_long) 0, 0);
724 		dep->de_flag |= DE_UPDATE;
725 		dep->de_Name[0] = SLOT_DELETED;
726 	}
727 	deupdat(dep, 0);
728 
729 out:
730 	/*
731 	 * If we are done with the denode, reclaim it
732 	 * so that it can be reused immediately.
733 	 */
734 #ifdef MSDOSFS_DEBUG
735 	kprintf("msdosfs_inactive(): v_sysrefs %d, de_Name[0] %x\n",
736 		vp->v_sysref.refcnt, (dep ? dep->de_Name[0] : 0));
737 #endif
738 	if (dep == NULL || dep->de_Name[0] == SLOT_DELETED)
739 		vrecycle(vp);
740 	return (error);
741 }
742