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msdosfs_denode.c revision 1.34
      1 /*	$NetBSD: msdosfs_denode.c,v 1.34 2009/03/14 15:36:21 dsl Exp $	*/
      2 
      3 /*-
      4  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
      5  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
      6  * All rights reserved.
      7  * Original code by Paul Popelka (paulp (at) uts.amdahl.com) (see below).
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed by TooLs GmbH.
     20  * 4. The name of TooLs GmbH may not be used to endorse or promote products
     21  *    derived from this software without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
     24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     26  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     28  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     29  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     30  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     31  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     32  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     33  */
     34 /*
     35  * Written by Paul Popelka (paulp (at) uts.amdahl.com)
     36  *
     37  * You can do anything you want with this software, just don't say you wrote
     38  * it, and don't remove this notice.
     39  *
     40  * This software is provided "as is".
     41  *
     42  * The author supplies this software to be publicly redistributed on the
     43  * understanding that the author is not responsible for the correct
     44  * functioning of this software in any circumstances and is not liable for
     45  * any damages caused by this software.
     46  *
     47  * October 1992
     48  */
     49 
     50 #include <sys/cdefs.h>
     51 __KERNEL_RCSID(0, "$NetBSD: msdosfs_denode.c,v 1.34 2009/03/14 15:36:21 dsl Exp $");
     52 
     53 #include <sys/param.h>
     54 #include <sys/systm.h>
     55 #include <sys/mount.h>
     56 #include <sys/malloc.h>
     57 #include <sys/pool.h>
     58 #include <sys/proc.h>
     59 #include <sys/buf.h>
     60 #include <sys/vnode.h>
     61 #include <sys/kernel.h>		/* defines "time" */
     62 #include <sys/dirent.h>
     63 #include <sys/namei.h>
     64 #include <sys/kauth.h>
     65 
     66 #include <uvm/uvm_extern.h>
     67 
     68 #include <fs/msdosfs/bpb.h>
     69 #include <fs/msdosfs/msdosfsmount.h>
     70 #include <fs/msdosfs/direntry.h>
     71 #include <fs/msdosfs/denode.h>
     72 #include <fs/msdosfs/fat.h>
     73 
     74 LIST_HEAD(ihashhead, denode) *dehashtbl;
     75 u_long dehash;			/* size of hash table - 1 */
     76 #define	DEHASH(dev, dcl, doff) \
     77     (((dev) + (dcl) + (doff) / sizeof(struct direntry)) & dehash)
     78 
     79 kmutex_t msdosfs_ihash_lock;
     80 kmutex_t msdosfs_hashlock;
     81 
     82 struct pool msdosfs_denode_pool;
     83 
     84 extern int prtactive;
     85 
     86 static const struct genfs_ops msdosfs_genfsops = {
     87 	.gop_size = genfs_size,
     88 	.gop_alloc = msdosfs_gop_alloc,
     89 	.gop_write = genfs_gop_write,
     90 	.gop_markupdate = msdosfs_gop_markupdate,
     91 };
     92 
     93 static struct denode *msdosfs_hashget(dev_t, u_long, u_long, int);
     94 static void msdosfs_hashins(struct denode *);
     95 static void msdosfs_hashrem(struct denode *);
     96 
     97 MALLOC_DECLARE(M_MSDOSFSFAT);
     98 
     99 void
    100 msdosfs_init()
    101 {
    102 
    103 	malloc_type_attach(M_MSDOSFSMNT);
    104 	malloc_type_attach(M_MSDOSFSFAT);
    105 	malloc_type_attach(M_MSDOSFSTMP);
    106 	pool_init(&msdosfs_denode_pool, sizeof(struct denode), 0, 0, 0,
    107 	    "msdosnopl", &pool_allocator_nointr, IPL_NONE);
    108 	dehashtbl = hashinit(desiredvnodes / 2, HASH_LIST, true, &dehash);
    109 	mutex_init(&msdosfs_ihash_lock, MUTEX_DEFAULT, IPL_NONE);
    110 	mutex_init(&msdosfs_hashlock, MUTEX_DEFAULT, IPL_NONE);
    111 }
    112 
    113 /*
    114  * Reinitialize inode hash table.
    115  */
    116 
    117 void
    118 msdosfs_reinit()
    119 {
    120 	struct denode *dep;
    121 	struct ihashhead *oldhash, *hash;
    122 	u_long oldmask, mask, val;
    123 	int i;
    124 
    125 	hash = hashinit(desiredvnodes / 2, HASH_LIST, true, &mask);
    126 
    127 	mutex_enter(&msdosfs_ihash_lock);
    128 	oldhash = dehashtbl;
    129 	oldmask = dehash;
    130 	dehashtbl = hash;
    131 	dehash = mask;
    132 	for (i = 0; i <= oldmask; i++) {
    133 		while ((dep = LIST_FIRST(&oldhash[i])) != NULL) {
    134 			LIST_REMOVE(dep, de_hash);
    135 			val = DEHASH(dep->de_dev, dep->de_dirclust,
    136 			    dep->de_diroffset);
    137 			LIST_INSERT_HEAD(&hash[val], dep, de_hash);
    138 		}
    139 	}
    140 	mutex_exit(&msdosfs_ihash_lock);
    141 	hashdone(oldhash, HASH_LIST, oldmask);
    142 }
    143 
    144 void
    145 msdosfs_done()
    146 {
    147 	hashdone(dehashtbl, HASH_LIST, dehash);
    148 	pool_destroy(&msdosfs_denode_pool);
    149 	mutex_destroy(&msdosfs_ihash_lock);
    150 	mutex_destroy(&msdosfs_hashlock);
    151 	malloc_type_detach(M_MSDOSFSTMP);
    152 	malloc_type_detach(M_MSDOSFSFAT);
    153 	malloc_type_detach(M_MSDOSFSMNT);
    154 }
    155 
    156 static struct denode *
    157 msdosfs_hashget(dev_t dev, u_long dirclust, u_long diroff, int flags)
    158 {
    159 	struct denode *dep;
    160 	struct vnode *vp;
    161 
    162 loop:
    163 	mutex_enter(&msdosfs_ihash_lock);
    164 	LIST_FOREACH(dep, &dehashtbl[DEHASH(dev, dirclust, diroff)], de_hash) {
    165 		if (dirclust == dep->de_dirclust &&
    166 		    diroff == dep->de_diroffset &&
    167 		    dev == dep->de_dev &&
    168 		    dep->de_refcnt != 0) {
    169 			vp = DETOV(dep);
    170 			if (flags == 0) {
    171 				mutex_exit(&msdosfs_ihash_lock);
    172 			} else {
    173 				mutex_enter(&vp->v_interlock);
    174 				mutex_exit(&msdosfs_ihash_lock);
    175 				if (vget(vp, flags | LK_INTERLOCK))
    176 					goto loop;
    177 			}
    178 			return (dep);
    179 		}
    180 	}
    181 	mutex_exit(&msdosfs_ihash_lock);
    182 	return (NULL);
    183 }
    184 
    185 static void
    186 msdosfs_hashins(struct denode *dep)
    187 {
    188 	struct ihashhead *depp;
    189 	int val;
    190 
    191 	KASSERT(mutex_owned(&msdosfs_hashlock));
    192 
    193 	mutex_enter(&msdosfs_ihash_lock);
    194 	val = DEHASH(dep->de_dev, dep->de_dirclust, dep->de_diroffset);
    195 	depp = &dehashtbl[val];
    196 	LIST_INSERT_HEAD(depp, dep, de_hash);
    197 	mutex_exit(&msdosfs_ihash_lock);
    198 }
    199 
    200 static void
    201 msdosfs_hashrem(struct denode *dep)
    202 {
    203 	mutex_enter(&msdosfs_ihash_lock);
    204 	LIST_REMOVE(dep, de_hash);
    205 	mutex_exit(&msdosfs_ihash_lock);
    206 }
    207 
    208 /*
    209  * If deget() succeeds it returns with the gotten denode locked().
    210  *
    211  * pmp	     - address of msdosfsmount structure of the filesystem containing
    212  *	       the denode of interest.  The pm_dev field and the address of
    213  *	       the msdosfsmount structure are used.
    214  * dirclust  - which cluster bp contains, if dirclust is 0 (root directory)
    215  *	       diroffset is relative to the beginning of the root directory,
    216  *	       otherwise it is cluster relative.
    217  * diroffset - offset past begin of cluster of denode we want
    218  * depp	     - returns the address of the gotten denode.
    219  */
    220 int
    221 deget(pmp, dirclust, diroffset, depp)
    222 	struct msdosfsmount *pmp;	/* so we know the maj/min number */
    223 	u_long dirclust;		/* cluster this dir entry came from */
    224 	u_long diroffset;		/* index of entry within the cluster */
    225 	struct denode **depp;		/* returns the addr of the gotten denode */
    226 {
    227 	int error;
    228 	extern int (**msdosfs_vnodeop_p)(void *);
    229 	struct direntry *direntptr;
    230 	struct denode *ldep;
    231 	struct vnode *nvp;
    232 	struct buf *bp;
    233 
    234 #ifdef MSDOSFS_DEBUG
    235 	printf("deget(pmp %p, dirclust %lu, diroffset %lx, depp %p)\n",
    236 	    pmp, dirclust, diroffset, depp);
    237 #endif
    238 
    239 	/*
    240 	 * On FAT32 filesystems, root is a (more or less) normal
    241 	 * directory
    242 	 */
    243 	if (FAT32(pmp) && dirclust == MSDOSFSROOT)
    244 		dirclust = pmp->pm_rootdirblk;
    245 
    246 	/*
    247 	 * See if the denode is in the denode cache. Use the location of
    248 	 * the directory entry to compute the hash value. For subdir use
    249 	 * address of "." entry. For root dir (if not FAT32) use cluster
    250 	 * MSDOSFSROOT, offset MSDOSFSROOT_OFS
    251 	 *
    252 	 * NOTE: The check for de_refcnt > 0 below insures the denode being
    253 	 * examined does not represent an unlinked but still open file.
    254 	 * These files are not to be accessible even when the directory
    255 	 * entry that represented the file happens to be reused while the
    256 	 * deleted file is still open.
    257 	 */
    258  retry:
    259 	ldep = msdosfs_hashget(pmp->pm_dev, dirclust, diroffset, LK_EXCLUSIVE);
    260 	if (ldep) {
    261 		*depp = ldep;
    262 		return (0);
    263 	}
    264 
    265 	/*
    266 	 * Directory entry was not in cache, have to create a vnode and
    267 	 * copy it from the passed disk buffer.
    268 	 */
    269 	/* getnewvnode() does a VREF() on the vnode */
    270 	error = getnewvnode(VT_MSDOSFS, pmp->pm_mountp,
    271 			    msdosfs_vnodeop_p, &nvp);
    272 	if (error) {
    273 		*depp = 0;
    274 		return (error);
    275 	}
    276 	ldep = pool_get(&msdosfs_denode_pool, PR_WAITOK);
    277 
    278 	/*
    279 	 * If someone beat us to it, put back the freshly allocated
    280 	 * vnode/inode pair and retry.
    281 	 */
    282 	mutex_enter(&msdosfs_hashlock);
    283 	if (msdosfs_hashget(pmp->pm_dev, dirclust, diroffset, 0)) {
    284 		mutex_exit(&msdosfs_hashlock);
    285 		ungetnewvnode(nvp);
    286 		pool_put(&msdosfs_denode_pool, ldep);
    287 		goto retry;
    288 	}
    289 	memset(ldep, 0, sizeof *ldep);
    290 	nvp->v_data = ldep;
    291 	ldep->de_vnode = nvp;
    292 	ldep->de_flag = 0;
    293 	ldep->de_devvp = 0;
    294 	ldep->de_lockf = 0;
    295 	ldep->de_dev = pmp->pm_dev;
    296 	ldep->de_dirclust = dirclust;
    297 	ldep->de_diroffset = diroffset;
    298 	fc_purge(ldep, 0);	/* init the fat cache for this denode */
    299 
    300 	/*
    301 	 * Insert the denode into the hash queue and lock the denode so it
    302 	 * can't be accessed until we've read it in and have done what we
    303 	 * need to it.
    304 	 */
    305 	vn_lock(nvp, LK_EXCLUSIVE | LK_RETRY);
    306 	genfs_node_init(nvp, &msdosfs_genfsops);
    307 	msdosfs_hashins(ldep);
    308 	mutex_exit(&msdosfs_hashlock);
    309 
    310 	ldep->de_pmp = pmp;
    311 	ldep->de_devvp = pmp->pm_devvp;
    312 	ldep->de_refcnt = 1;
    313 	/*
    314 	 * Copy the directory entry into the denode area of the vnode.
    315 	 */
    316 	if ((dirclust == MSDOSFSROOT
    317 	     || (FAT32(pmp) && dirclust == pmp->pm_rootdirblk))
    318 	    && diroffset == MSDOSFSROOT_OFS) {
    319 		/*
    320 		 * Directory entry for the root directory. There isn't one,
    321 		 * so we manufacture one. We should probably rummage
    322 		 * through the root directory and find a label entry (if it
    323 		 * exists), and then use the time and date from that entry
    324 		 * as the time and date for the root denode.
    325 		 */
    326 		nvp->v_vflag |= VV_ROOT; /* should be further down XXX */
    327 
    328 		ldep->de_Attributes = ATTR_DIRECTORY;
    329 		if (FAT32(pmp))
    330 			ldep->de_StartCluster = pmp->pm_rootdirblk;
    331 			/* de_FileSize will be filled in further down */
    332 		else {
    333 			ldep->de_StartCluster = MSDOSFSROOT;
    334 			ldep->de_FileSize = pmp->pm_rootdirsize * pmp->pm_BytesPerSec;
    335 		}
    336 		/*
    337 		 * fill in time and date so that dos2unixtime() doesn't
    338 		 * spit up when called from msdosfs_getattr() with root
    339 		 * denode
    340 		 */
    341 		ldep->de_CHun = 0;
    342 		ldep->de_CTime = 0x0000;	/* 00:00:00	 */
    343 		ldep->de_CDate = (0 << DD_YEAR_SHIFT) | (1 << DD_MONTH_SHIFT)
    344 		    | (1 << DD_DAY_SHIFT);
    345 		/* Jan 1, 1980	 */
    346 		ldep->de_ADate = ldep->de_CDate;
    347 		ldep->de_MTime = ldep->de_CTime;
    348 		ldep->de_MDate = ldep->de_CDate;
    349 		/* leave the other fields as garbage */
    350 	} else {
    351 		error = readep(pmp, dirclust, diroffset, &bp, &direntptr);
    352 		if (error) {
    353 			ldep->de_devvp = NULL;
    354 			ldep->de_Name[0] = SLOT_DELETED;
    355 			vput(nvp);
    356 			return (error);
    357 		}
    358 		DE_INTERNALIZE(ldep, direntptr);
    359 		brelse(bp, 0);
    360 	}
    361 
    362 	/*
    363 	 * Fill in a few fields of the vnode and finish filling in the
    364 	 * denode.  Then return the address of the found denode.
    365 	 */
    366 	if (ldep->de_Attributes & ATTR_DIRECTORY) {
    367 		/*
    368 		 * Since DOS directory entries that describe directories
    369 		 * have 0 in the filesize field, we take this opportunity
    370 		 * to find out the length of the directory and plug it into
    371 		 * the denode structure.
    372 		 */
    373 		u_long size;
    374 
    375 		nvp->v_type = VDIR;
    376 		if (ldep->de_StartCluster != MSDOSFSROOT) {
    377 			error = pcbmap(ldep, CLUST_END, 0, &size, 0);
    378 			if (error == E2BIG) {
    379 				ldep->de_FileSize = de_cn2off(pmp, size);
    380 				error = 0;
    381 			} else
    382 				printf("deget(): pcbmap returned %d\n", error);
    383 		}
    384 	} else
    385 		nvp->v_type = VREG;
    386 	VREF(ldep->de_devvp);
    387 	*depp = ldep;
    388 	uvm_vnp_setsize(nvp, ldep->de_FileSize);
    389 	return (0);
    390 }
    391 
    392 int
    393 deupdat(struct denode *dep, int waitfor)
    394 {
    395 
    396 	return (msdosfs_update(DETOV(dep), NULL, NULL,
    397 	    waitfor ? UPDATE_WAIT : 0));
    398 }
    399 
    400 /*
    401  * Truncate the file described by dep to the length specified by length.
    402  */
    403 int
    404 detrunc(struct denode *dep, u_long length, int flags, kauth_cred_t cred)
    405 {
    406 	int error;
    407 	int allerror;
    408 	u_long eofentry;
    409 	u_long chaintofree = 0;
    410 	daddr_t bn, lastblock;
    411 	int boff;
    412 	int isadir = dep->de_Attributes & ATTR_DIRECTORY;
    413 	struct buf *bp;
    414 	struct msdosfsmount *pmp = dep->de_pmp;
    415 
    416 #ifdef MSDOSFS_DEBUG
    417 	printf("detrunc(): file %s, length %lu, flags %x\n", dep->de_Name, length, flags);
    418 #endif
    419 
    420 	/*
    421 	 * Disallow attempts to truncate the root directory since it is of
    422 	 * fixed size.  That's just the way dos filesystems are.  We use
    423 	 * the VROOT bit in the vnode because checking for the directory
    424 	 * bit and a startcluster of 0 in the denode is not adequate to
    425 	 * recognize the root directory at this point in a file or
    426 	 * directory's life.
    427 	 */
    428 	if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp)) {
    429 		printf("detrunc(): can't truncate root directory, clust %ld, offset %ld\n",
    430 		    dep->de_dirclust, dep->de_diroffset);
    431 		return (EINVAL);
    432 	}
    433 
    434 	uvm_vnp_setsize(DETOV(dep), length);
    435 
    436 	if (dep->de_FileSize < length)
    437 		return (deextend(dep, length, cred));
    438 	lastblock = de_clcount(pmp, length) - 1;
    439 
    440 	/*
    441 	 * If the desired length is 0 then remember the starting cluster of
    442 	 * the file and set the StartCluster field in the directory entry
    443 	 * to 0.  If the desired length is not zero, then get the number of
    444 	 * the last cluster in the shortened file.  Then get the number of
    445 	 * the first cluster in the part of the file that is to be freed.
    446 	 * Then set the next cluster pointer in the last cluster of the
    447 	 * file to CLUST_EOFE.
    448 	 */
    449 	if (length == 0) {
    450 		chaintofree = dep->de_StartCluster;
    451 		dep->de_StartCluster = 0;
    452 		eofentry = ~0;
    453 	} else {
    454 		error = pcbmap(dep, lastblock, 0, &eofentry, 0);
    455 		if (error) {
    456 #ifdef MSDOSFS_DEBUG
    457 			printf("detrunc(): pcbmap fails %d\n", error);
    458 #endif
    459 			return (error);
    460 		}
    461 	}
    462 
    463 	fc_purge(dep, lastblock + 1);
    464 
    465 	/*
    466 	 * If the new length is not a multiple of the cluster size then we
    467 	 * must zero the tail end of the new last cluster in case it
    468 	 * becomes part of the file again because of a seek.
    469 	 */
    470 	if ((boff = length & pmp->pm_crbomask) != 0) {
    471 		if (isadir) {
    472 			bn = cntobn(pmp, eofentry);
    473 			error = bread(pmp->pm_devvp, de_bn2kb(pmp, bn),
    474 			    pmp->pm_bpcluster, NOCRED, B_MODIFY, &bp);
    475 			if (error) {
    476 				brelse(bp, 0);
    477 #ifdef MSDOSFS_DEBUG
    478 				printf("detrunc(): bread fails %d\n", error);
    479 #endif
    480 				return (error);
    481 			}
    482 			memset((char *)bp->b_data + boff, 0,
    483 			    pmp->pm_bpcluster - boff);
    484 			if (flags & IO_SYNC)
    485 				bwrite(bp);
    486 			else
    487 				bdwrite(bp);
    488 		} else {
    489 			uvm_vnp_zerorange(DETOV(dep), length,
    490 					  pmp->pm_bpcluster - boff);
    491 		}
    492 	}
    493 
    494 	/*
    495 	 * Write out the updated directory entry.  Even if the update fails
    496 	 * we free the trailing clusters.
    497 	 */
    498 	dep->de_FileSize = length;
    499 	if (!isadir)
    500 		dep->de_flag |= DE_UPDATE|DE_MODIFIED;
    501 	vtruncbuf(DETOV(dep), lastblock + 1, 0, 0);
    502 	allerror = deupdat(dep, 1);
    503 #ifdef MSDOSFS_DEBUG
    504 	printf("detrunc(): allerror %d, eofentry %lu\n",
    505 	       allerror, eofentry);
    506 #endif
    507 
    508 	/*
    509 	 * If we need to break the cluster chain for the file then do it
    510 	 * now.
    511 	 */
    512 	if (eofentry != ~0) {
    513 		error = fatentry(FAT_GET_AND_SET, pmp, eofentry,
    514 				 &chaintofree, CLUST_EOFE);
    515 		if (error) {
    516 #ifdef MSDOSFS_DEBUG
    517 			printf("detrunc(): fatentry errors %d\n", error);
    518 #endif
    519 			return (error);
    520 		}
    521 		fc_setcache(dep, FC_LASTFC, de_cluster(pmp, length - 1),
    522 			    eofentry);
    523 	}
    524 
    525 	/*
    526 	 * Now free the clusters removed from the file because of the
    527 	 * truncation.
    528 	 */
    529 	if (chaintofree != 0 && !MSDOSFSEOF(chaintofree, pmp->pm_fatmask))
    530 		freeclusterchain(pmp, chaintofree);
    531 
    532 	return (allerror);
    533 }
    534 
    535 /*
    536  * Extend the file described by dep to length specified by length.
    537  */
    538 int
    539 deextend(struct denode *dep, u_long length, kauth_cred_t cred)
    540 {
    541 	struct msdosfsmount *pmp = dep->de_pmp;
    542 	u_long count, osize;
    543 	int error;
    544 
    545 	/*
    546 	 * The root of a DOS filesystem cannot be extended.
    547 	 */
    548 	if ((DETOV(dep)->v_vflag & VV_ROOT) && !FAT32(pmp))
    549 		return (EINVAL);
    550 
    551 	/*
    552 	 * Directories cannot be extended.
    553 	 */
    554 	if (dep->de_Attributes & ATTR_DIRECTORY)
    555 		return (EISDIR);
    556 
    557 	if (length <= dep->de_FileSize)
    558 		panic("deextend: file too large");
    559 
    560 	/*
    561 	 * Compute the number of clusters to allocate.
    562 	 */
    563 	count = de_clcount(pmp, length) - de_clcount(pmp, dep->de_FileSize);
    564 	if (count > 0) {
    565 		if (count > pmp->pm_freeclustercount)
    566 			return (ENOSPC);
    567 		error = extendfile(dep, count, NULL, NULL, DE_CLEAR);
    568 		if (error) {
    569 			/* truncate the added clusters away again */
    570 			(void) detrunc(dep, dep->de_FileSize, 0, cred);
    571 			return (error);
    572 		}
    573 	}
    574 
    575 	/*
    576 	 * Zero extend file range; uvm_vnp_zerorange() uses ubc_alloc() and a
    577 	 * memset(); we set the write size so ubc won't read in file data that
    578 	 * is zero'd later.
    579 	 */
    580 	osize = dep->de_FileSize;
    581 	dep->de_FileSize = length;
    582 	uvm_vnp_setwritesize(DETOV(dep), (voff_t)dep->de_FileSize);
    583 	dep->de_flag |= DE_UPDATE|DE_MODIFIED;
    584 	uvm_vnp_zerorange(DETOV(dep), (off_t)osize,
    585 	    (size_t)(dep->de_FileSize - osize));
    586 	uvm_vnp_setsize(DETOV(dep), (voff_t)dep->de_FileSize);
    587 	return (deupdat(dep, 1));
    588 }
    589 
    590 /*
    591  * Move a denode to its correct hash queue after the file it represents has
    592  * been moved to a new directory.
    593  */
    594 void
    595 reinsert(struct denode *dep)
    596 {
    597 	/*
    598 	 * Fix up the denode cache.  If the denode is for a directory,
    599 	 * there is nothing to do since the hash is based on the starting
    600 	 * cluster of the directory file and that hasn't changed.  If for a
    601 	 * file the hash is based on the location of the directory entry,
    602 	 * so we must remove it from the cache and re-enter it with the
    603 	 * hash based on the new location of the directory entry.
    604 	 */
    605 	if (dep->de_Attributes & ATTR_DIRECTORY)
    606 		return;
    607 	mutex_enter(&msdosfs_hashlock);
    608 	msdosfs_hashrem(dep);
    609 	msdosfs_hashins(dep);
    610 	mutex_exit(&msdosfs_hashlock);
    611 }
    612 
    613 int
    614 msdosfs_reclaim(void *v)
    615 {
    616 	struct vop_reclaim_args /* {
    617 		struct vnode *a_vp;
    618 	} */ *ap = v;
    619 	struct vnode *vp = ap->a_vp;
    620 	struct denode *dep = VTODE(vp);
    621 
    622 #ifdef MSDOSFS_DEBUG
    623 	printf("msdosfs_reclaim(): dep %p, file %s, refcnt %ld\n",
    624 	    dep, dep->de_Name, dep->de_refcnt);
    625 #endif
    626 
    627 	if (prtactive && vp->v_usecount > 1)
    628 		vprint("msdosfs_reclaim(): pushing active", vp);
    629 	/*
    630 	 * Remove the denode from its hash chain.
    631 	 */
    632 	msdosfs_hashrem(dep);
    633 	/*
    634 	 * Purge old data structures associated with the denode.
    635 	 */
    636 	cache_purge(vp);
    637 	if (dep->de_devvp) {
    638 		vrele(dep->de_devvp);
    639 		dep->de_devvp = 0;
    640 	}
    641 #if 0 /* XXX */
    642 	dep->de_flag = 0;
    643 #endif
    644 	genfs_node_destroy(vp);
    645 	pool_put(&msdosfs_denode_pool, dep);
    646 	vp->v_data = NULL;
    647 	return (0);
    648 }
    649 
    650 int
    651 msdosfs_inactive(void *v)
    652 {
    653 	struct vop_inactive_args /* {
    654 		struct vnode *a_vp;
    655 		bool *a_recycle;
    656 	} */ *ap = v;
    657 	struct vnode *vp = ap->a_vp;
    658 	struct denode *dep = VTODE(vp);
    659 	int error = 0;
    660 
    661 #ifdef MSDOSFS_DEBUG
    662 	printf("msdosfs_inactive(): dep %p, de_Name[0] %x\n", dep, dep->de_Name[0]);
    663 #endif
    664 
    665 	/*
    666 	 * Get rid of denodes related to stale file handles.
    667 	 */
    668 	if (dep->de_Name[0] == SLOT_DELETED)
    669 		goto out;
    670 
    671 	/*
    672 	 * If the file has been deleted and it is on a read/write
    673 	 * filesystem, then truncate the file, and mark the directory slot
    674 	 * as empty.  (This may not be necessary for the dos filesystem.)
    675 	 */
    676 #ifdef MSDOSFS_DEBUG
    677 	printf("msdosfs_inactive(): dep %p, refcnt %ld, mntflag %x %s\n",
    678 	       dep, dep->de_refcnt, vp->v_mount->mnt_flag,
    679 		(vp->v_mount->mnt_flag & MNT_RDONLY) ? "MNT_RDONLY" : "");
    680 #endif
    681 	if (dep->de_refcnt <= 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
    682 		if (dep->de_FileSize != 0) {
    683 			error = detrunc(dep, (u_long)0, 0, NOCRED);
    684 		}
    685 		dep->de_Name[0] = SLOT_DELETED;
    686 	}
    687 	deupdat(dep, 0);
    688 out:
    689 	/*
    690 	 * If we are done with the denode, reclaim it
    691 	 * so that it can be reused immediately.
    692 	 */
    693 #ifdef MSDOSFS_DEBUG
    694 	printf("msdosfs_inactive(): v_usecount %d, de_Name[0] %x\n",
    695 		vp->v_usecount, dep->de_Name[0]);
    696 #endif
    697 	*ap->a_recycle = (dep->de_Name[0] == SLOT_DELETED);
    698 	VOP_UNLOCK(vp, 0);
    699 	return (error);
    700 }
    701 
    702 int
    703 msdosfs_gop_alloc(struct vnode *vp, off_t off,
    704     off_t len, int flags, kauth_cred_t cred)
    705 {
    706 	return 0;
    707 }
    708 
    709 void
    710 msdosfs_gop_markupdate(struct vnode *vp, int flags)
    711 {
    712 	u_long mask = 0;
    713 
    714 	if ((flags & GOP_UPDATE_ACCESSED) != 0) {
    715 		mask = DE_ACCESS;
    716 	}
    717 	if ((flags & GOP_UPDATE_MODIFIED) != 0) {
    718 		mask |= DE_UPDATE;
    719 	}
    720 	if (mask) {
    721 		struct denode *dep = VTODE(vp);
    722 
    723 		dep->de_flag |= mask;
    724 	}
    725 }
    726