xref: /dflybsd-src/sys/vfs/msdosfs/msdosfs_vnops.c (revision 8bdbc095884336714d87f2877b79c17d22de5cd3)
1 /* $FreeBSD: src/sys/msdosfs/msdosfs_vnops.c,v 1.95.2.4 2003/06/13 15:05:47 trhodes Exp $ */
2 /*	$NetBSD: msdosfs_vnops.c,v 1.68 1998/02/10 14:10:04 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/resourcevar.h>	/* defines plimit structure in proc struct */
54 #include <sys/kernel.h>
55 #include <sys/stat.h>
56 #include <sys/buf.h>
57 #include <sys/proc.h>
58 #include <sys/priv.h>
59 #include <sys/namei.h>
60 #include <sys/mount.h>
61 #include <sys/unistd.h>
62 #include <sys/vnode.h>
63 #include <sys/malloc.h>
64 #include <sys/dirent.h>
65 #include <sys/signalvar.h>
66 
67 #include <vm/vm.h>
68 #include <vm/vm_extern.h>
69 #include <vm/vm_zone.h>
70 #include <vm/vnode_pager.h>
71 
72 #include <sys/buf2.h>
73 
74 #include <machine/inttypes.h>
75 
76 #include "bpb.h"
77 #include "direntry.h"
78 #include "denode.h"
79 #include "msdosfsmount.h"
80 #include "fat.h"
81 
82 #define	DOS_FILESIZE_MAX	0xffffffff
83 
84 /*
85  * Some general notes:
86  *
87  * In the ufs filesystem the inodes, superblocks, and indirect blocks are
88  * read/written using the vnode for the filesystem. Blocks that represent
89  * the contents of a file are read/written using the vnode for the file
90  * (including directories when they are read/written as files). This
91  * presents problems for the dos filesystem because data that should be in
92  * an inode (if dos had them) resides in the directory itself.  Since we
93  * must update directory entries without the benefit of having the vnode
94  * for the directory we must use the vnode for the filesystem.  This means
95  * that when a directory is actually read/written (via read, write, or
96  * readdir, or seek) we must use the vnode for the filesystem instead of
97  * the vnode for the directory as would happen in ufs. This is to insure we
98  * retreive the correct block from the buffer cache since the hash value is
99  * based upon the vnode address and the desired block number.
100  */
101 
102 /*
103  * Create a regular file. On entry the directory to contain the file being
104  * created is locked.  We must release before we return.
105  *
106  * msdosfs_create(struct vnode *a_dvp, struct vnode **a_vpp,
107  *		  struct componentname *a_cnp, struct vattr *a_vap)
108  */
109 static int
110 msdosfs_create(struct vop_old_create_args *ap)
111 {
112 	struct componentname *cnp = ap->a_cnp;
113 	struct denode ndirent;
114 	struct denode *dep;
115 	struct denode *pdep = VTODE(ap->a_dvp);
116 	struct timespec ts;
117 	int error;
118 
119 	mprintf("msdosfs_create(cnp %p, vap %p\n", cnp, ap->a_vap);
120 
121 	/*
122 	 * If this is the root directory and there is no space left we
123 	 * can't do anything.  This is because the root directory can not
124 	 * change size.
125 	 */
126 	if (pdep->de_StartCluster == MSDOSFSROOT
127 	    && pdep->de_fndoffset >= pdep->de_FileSize) {
128 		error = ENOSPC;
129 		goto bad;
130 	}
131 
132 	/*
133 	 * Create a directory entry for the file, then call createde() to
134 	 * have it installed. NOTE: DOS files are always executable.  We
135 	 * use the absence of the owner write bit to make the file
136 	 * readonly.
137 	 */
138 	bzero(&ndirent, sizeof(ndirent));
139 	error = uniqdosname(pdep, cnp, ndirent.de_Name);
140 	if (error)
141 		goto bad;
142 
143 	ndirent.de_Attributes = (ap->a_vap->va_mode & VWRITE) ?
144 				ATTR_ARCHIVE : ATTR_ARCHIVE | ATTR_READONLY;
145 	ndirent.de_LowerCase = 0;
146 	ndirent.de_StartCluster = 0;
147 	ndirent.de_FileSize = 0;
148 	ndirent.de_dev = pdep->de_dev;
149 	ndirent.de_devvp = pdep->de_devvp;
150 	ndirent.de_pmp = pdep->de_pmp;
151 	ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
152 	getnanotime(&ts);
153 	DETIMES(&ndirent, &ts, &ts, &ts);
154 	error = createde(&ndirent, pdep, &dep, cnp);
155 	if (error)
156 		goto bad;
157 	*ap->a_vpp = DETOV(dep);
158 	return (0);
159 
160 bad:
161 	return (error);
162 }
163 
164 static int msdosfs_mkdir(struct vop_old_mkdir_args *);
165 
166 /*
167  * msdosfs_mknod(struct vnode *a_dvp, struct vnode **a_vpp,
168  *		 struct componentname *a_cnp, struct vattr *a_vap)
169  */
170 static int
171 msdosfs_mknod(struct vop_old_mknod_args *ap)
172 {
173 	switch (ap->a_vap->va_type) {
174 	case VDIR:
175 		return (msdosfs_mkdir((struct vop_old_mkdir_args *)ap));
176 	case VREG:
177 		return (msdosfs_create((struct vop_old_create_args *)ap));
178 	default:
179 		return (EINVAL);
180 	}
181 	/* NOTREACHED */
182 }
183 
184 /*
185  * msdosfs_open(struct vnode *a_vp, int a_mode, struct ucred *a_cred,
186  *		struct file *a_fp)
187  */
188 static int
189 msdosfs_open(struct vop_open_args *ap)
190 {
191 	return(vop_stdopen(ap));
192 }
193 
194 /*
195  * msdosfs_close(struct vnode *a_vp, int a_fflag)
196  */
197 static int
198 msdosfs_close(struct vop_close_args *ap)
199 {
200 	struct vnode *vp = ap->a_vp;
201 	struct denode *dep = VTODE(vp);
202 	struct timespec ts;
203 
204 	if (VREFCNT(vp) > 1) {
205 		getnanotime(&ts);
206 		DETIMES(dep, &ts, &ts, &ts);
207 	}
208 	return (vop_stdclose(ap));
209 }
210 
211 /*
212  * msdosfs_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred)
213  */
214 static int
215 msdosfs_access(struct vop_access_args *ap)
216 {
217 	struct denode *dep = VTODE(ap->a_vp);
218 	struct msdosfsmount *pmp = dep->de_pmp;
219 	mode_t file_mode;
220 
221 	file_mode = (S_IXUSR|S_IXGRP|S_IXOTH) | (S_IRUSR|S_IRGRP|S_IROTH) |
222 	    ((dep->de_Attributes & ATTR_READONLY) ?
223 	    0 : (S_IWUSR|S_IWGRP|S_IWOTH));
224 	file_mode &= pmp->pm_mask;
225 
226 	return (vop_helper_access(ap, pmp->pm_uid, pmp->pm_gid, file_mode, 0));
227 }
228 
229 /*
230  * msdosfs_getattr(struct vnode *a_vp, struct vattr *a_vap)
231  */
232 static int
233 msdosfs_getattr(struct vop_getattr_args *ap)
234 {
235 	struct denode *dep = VTODE(ap->a_vp);
236 	struct msdosfsmount *pmp = dep->de_pmp;
237 	struct vattr *vap = ap->a_vap;
238 	mode_t mode;
239 	struct timespec ts;
240 	u_long dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
241 	u_long fileid;
242 
243 	getnanotime(&ts);
244 	DETIMES(dep, &ts, &ts, &ts);
245 	vap->va_fsid = dev2udev(dep->de_dev);
246 	/*
247 	 * The following computation of the fileid must be the same as that
248 	 * used in msdosfs_readdir() to compute d_fileno. If not, pwd
249 	 * doesn't work.
250 	 */
251 	if (dep->de_Attributes & ATTR_DIRECTORY) {
252 		fileid = xcntobn(pmp, dep->de_StartCluster) * dirsperblk;
253 		if (dep->de_StartCluster == MSDOSFSROOT)
254 			fileid = 1;
255 	} else {
256 		fileid = xcntobn(pmp, dep->de_dirclust) * dirsperblk;
257 		if (dep->de_dirclust == MSDOSFSROOT)
258 			fileid = roottobn(pmp, 0) * dirsperblk;
259 		fileid += dep->de_diroffset / sizeof(struct direntry);
260 	}
261 	vap->va_fileid = fileid;
262 	if ((dep->de_Attributes & ATTR_READONLY) == 0)
263 		mode = S_IRWXU|S_IRWXG|S_IRWXO;
264 	else
265 		mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
266 	vap->va_mode = mode & pmp->pm_mask;
267 	vap->va_uid = pmp->pm_uid;
268 	vap->va_gid = pmp->pm_gid;
269 	vap->va_nlink = 1;
270 	vap->va_rmajor = VNOVAL;
271 	vap->va_rminor = VNOVAL;
272 	vap->va_size = dep->de_FileSize;
273 	dos2unixtime(dep->de_MDate, dep->de_MTime, 0, &vap->va_mtime);
274 	if (pmp->pm_flags & MSDOSFSMNT_LONGNAME) {
275 		dos2unixtime(dep->de_ADate, 0, 0, &vap->va_atime);
276 		dos2unixtime(dep->de_CDate, dep->de_CTime, dep->de_CHun,
277 			     &vap->va_ctime);
278 	} else {
279 		vap->va_atime = vap->va_mtime;
280 		vap->va_ctime = vap->va_mtime;
281 	}
282 	vap->va_flags = 0;
283 	if ((dep->de_Attributes & ATTR_ARCHIVE) == 0)
284 		vap->va_flags |= SF_ARCHIVED;
285 	vap->va_gen = 0;
286 	vap->va_blocksize = pmp->pm_bpcluster;
287 	vap->va_bytes =
288 	    (dep->de_FileSize + pmp->pm_crbomask) & ~pmp->pm_crbomask;
289 	vap->va_type = ap->a_vp->v_type;
290 	vap->va_filerev = dep->de_modrev;
291 	return (0);
292 }
293 
294 /*
295  * msdosfs_setattr(struct vnode *a_vp, struct vattr *a_vap,
296  *		   struct ucred *a_cred)
297  */
298 static int
299 msdosfs_setattr(struct vop_setattr_args *ap)
300 {
301 	struct vnode *vp = ap->a_vp;
302 	struct denode *dep = VTODE(vp);
303 	struct msdosfsmount *pmp = dep->de_pmp;
304 	struct vattr *vap = ap->a_vap;
305 	struct ucred *cred = ap->a_cred;
306 	int error = 0;
307 
308 	mprintf("msdosfs_setattr(): vp %p, vap %p, cred %p\n", vp, vap, cred);
309 
310 	/*
311 	 * Check for unsettable attributes.
312 	 */
313 	if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
314 	    (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
315 	    (vap->va_blocksize != VNOVAL) || (vap->va_rmajor != VNOVAL) ||
316 	    (vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
317 		mprintf("msdosfs_setattr(): returning EINVAL\n");
318 		mprintf("    va_type %u, va_nlink %"PRIx64", va_fsid %x, va_fileid %"PRIx64"\n",
319 		    vap->va_type, vap->va_nlink, vap->va_fsid, vap->va_fileid);
320 		mprintf("    va_blocksize %lx, va_rmajor %x, va_bytes %"PRIx64", va_gen %"PRIx64"\n",
321 		    vap->va_blocksize, vap->va_rmajor, vap->va_bytes,
322 		    vap->va_gen);
323 		mprintf("    va_uid %x, va_gid %x\n",
324 		    vap->va_uid, vap->va_gid);
325 		return (EINVAL);
326 	}
327 	if (vap->va_flags != VNOVAL) {
328 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
329 			return (EROFS);
330 		if (cred->cr_uid != pmp->pm_uid &&
331 		    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)))
332 			return (error);
333 		/*
334 		 * We are very inconsistent about handling unsupported
335 		 * attributes.  We ignored the access time and the
336 		 * read and execute bits.  We were strict for the other
337 		 * attributes.
338 		 *
339 		 * Here we are strict, stricter than ufs in not allowing
340 		 * users to attempt to set SF_SETTABLE bits or anyone to
341 		 * set unsupported bits.  However, we ignore attempts to
342 		 * set ATTR_ARCHIVE for directories `cp -pr' from a more
343 		 * sensible file system attempts it a lot.
344 		 */
345 		if (cred->cr_uid != 0) {
346 			if (vap->va_flags & SF_SETTABLE)
347 				return EPERM;
348 		}
349 		if (vap->va_flags & ~SF_ARCHIVED)
350 			return EOPNOTSUPP;
351 		if (vap->va_flags & SF_ARCHIVED)
352 			dep->de_Attributes &= ~ATTR_ARCHIVE;
353 		else if (!(dep->de_Attributes & ATTR_DIRECTORY))
354 			dep->de_Attributes |= ATTR_ARCHIVE;
355 		dep->de_flag |= DE_MODIFIED;
356 	}
357 
358 	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
359 		uid_t uid;
360 		gid_t gid;
361 
362 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
363 			return (EROFS);
364 		uid = vap->va_uid;
365 		if (uid == (uid_t)VNOVAL)
366 			uid = pmp->pm_uid;
367 		gid = vap->va_gid;
368 		if (gid == (gid_t)VNOVAL)
369 			gid = pmp->pm_gid;
370 		if ((cred->cr_uid != pmp->pm_uid || uid != pmp->pm_uid ||
371 		    (gid != pmp->pm_gid && !groupmember(gid, cred))) &&
372 		    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)))
373 			return error;
374 		if (uid != pmp->pm_uid || gid != pmp->pm_gid)
375 			return EINVAL;
376 	}
377 
378 	if (vap->va_size != VNOVAL) {
379 		/*
380 		 * Disallow write attempts on read-only file systems;
381 		 * unless the file is a socket, fifo, or a block or
382 		 * character device resident on the file system.
383 		 */
384 		switch (vp->v_type) {
385 		case VDIR:
386 			return (EISDIR);
387 			/* NOT REACHED */
388 		case VLNK:
389 		case VREG:
390 			if (vp->v_mount->mnt_flag & MNT_RDONLY)
391 				return (EROFS);
392 			break;
393 		default:
394 			break;
395 		}
396 		error = detrunc(dep, vap->va_size, 0);
397 		if (error)
398 			return error;
399 	}
400 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
401 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
402 			return (EROFS);
403 		if (cred->cr_uid != pmp->pm_uid &&
404 		    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)) &&
405 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
406 		    (error = VOP_EACCESS(vp, VWRITE, cred))))
407 			return (error);
408 		if (vp->v_type != VDIR) {
409 			if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) == 0 &&
410 			    vap->va_atime.tv_sec != VNOVAL) {
411 				dep->de_flag &= ~DE_ACCESS;
412 				unix2dostime(&vap->va_atime, &dep->de_ADate,
413 				    NULL, NULL);
414 			}
415 			if (vap->va_mtime.tv_sec != VNOVAL) {
416 				dep->de_flag &= ~DE_UPDATE;
417 				unix2dostime(&vap->va_mtime, &dep->de_MDate,
418 				    &dep->de_MTime, NULL);
419 			}
420 			dep->de_Attributes |= ATTR_ARCHIVE;
421 			dep->de_flag |= DE_MODIFIED;
422 		}
423 	}
424 	/*
425 	 * DOS files only have the ability to have their writability
426 	 * attribute set, so we use the owner write bit to set the readonly
427 	 * attribute.
428 	 */
429 	if (vap->va_mode != (mode_t)VNOVAL) {
430 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
431 			return (EROFS);
432 		if (cred->cr_uid != pmp->pm_uid &&
433 		    (error = priv_check_cred(cred, PRIV_VFS_SETATTR, 0)))
434 			return (error);
435 		if (vp->v_type != VDIR) {
436 			/* We ignore the read and execute bits. */
437 			if (vap->va_mode & VWRITE)
438 				dep->de_Attributes &= ~ATTR_READONLY;
439 			else
440 				dep->de_Attributes |= ATTR_READONLY;
441 			dep->de_Attributes |= ATTR_ARCHIVE;
442 			dep->de_flag |= DE_MODIFIED;
443 		}
444 	}
445 	return (deupdat(dep, 1));
446 }
447 
448 /*
449  * msdosfs_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
450  *		struct ucred *a_cred)
451  */
452 static int
453 msdosfs_read(struct vop_read_args *ap)
454 {
455 	int error = 0;
456 	int blsize;
457 	int isadir;
458 	size_t orig_resid;
459 	u_int n;
460 	u_long diff;
461 	u_long on;
462 	daddr_t lbn;
463 	daddr_t rablock;
464 	off_t raoffset;
465 	off_t loffset;
466 	int rasize;
467 	int seqcount;
468 	struct buf *bp;
469 	struct vnode *vp = ap->a_vp;
470 	struct denode *dep = VTODE(vp);
471 	struct msdosfsmount *pmp = dep->de_pmp;
472 	struct uio *uio = ap->a_uio;
473 
474 	if (uio->uio_offset < 0)
475 		return (EINVAL);
476 
477 	if ((uoff_t)uio->uio_offset > DOS_FILESIZE_MAX)
478                 return (0);
479 	/*
480 	 * If they didn't ask for any data, then we are done.
481 	 */
482 	orig_resid = uio->uio_resid;
483 	if (orig_resid == 0)
484 		return (0);
485 
486 	seqcount = ap->a_ioflag >> IO_SEQSHIFT;
487 
488 	isadir = dep->de_Attributes & ATTR_DIRECTORY;
489 	do {
490 		if (uio->uio_offset >= dep->de_FileSize)
491 			break;
492 
493 		/*
494 		 * note: lbn is a cluster number, not a device block number.
495 		 */
496 		lbn = de_off2cn(pmp, uio->uio_offset);
497 		loffset = de_cn2doff(pmp, lbn);
498 
499 		/*
500 		 * If we are operating on a directory file then be sure to
501 		 * do i/o with the vnode for the filesystem instead of the
502 		 * vnode for the directory.
503 		 */
504 		if (isadir) {
505 			/*
506 			 * convert cluster # to block #.  lbn is a
507 			 * device block number after this.
508 			 */
509 			error = pcbmap(dep, lbn, &lbn, NULL, &blsize);
510 			loffset = de_bntodoff(pmp, lbn);
511 			if (error == E2BIG) {
512 				error = EINVAL;
513 				break;
514 			} else if (error)
515 				break;
516 			error = bread(pmp->pm_devvp, loffset, blsize, &bp);
517 		} else {
518 			blsize = pmp->pm_bpcluster;
519 			rablock = lbn + 1;
520 			raoffset = de_cn2doff(pmp, rablock);
521 			if (seqcount > 1 &&
522 			    raoffset < dep->de_FileSize) {
523 				rasize = pmp->pm_bpcluster;
524 				error = breadn(vp, loffset, blsize,
525 					       &raoffset, &rasize, 1, &bp);
526 			} else {
527 				error = bread(vp, loffset, blsize, &bp);
528 			}
529 		}
530 		if (error) {
531 			brelse(bp);
532 			break;
533 		}
534 		on = uio->uio_offset & pmp->pm_crbomask;
535 		diff = pmp->pm_bpcluster - on;
536 		n = szmin(uio->uio_resid, diff);
537 		diff = dep->de_FileSize - uio->uio_offset;
538 		if (diff < n)
539 			n = diff;
540 		diff = blsize - bp->b_resid;
541 		if (diff < n)
542 			n = diff;
543 		error = uiomovebp(bp, bp->b_data + on, (size_t)n, uio);
544 		brelse(bp);
545 	} while (error == 0 && uio->uio_resid > 0 && n != 0);
546 
547 	if (!isadir && (error == 0 || uio->uio_resid != orig_resid) &&
548 	    (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
549 		dep->de_flag |= DE_ACCESS;
550 	return (error);
551 }
552 
553 /*
554  * Write data to a file or directory.
555  *
556  * msdosfs_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
557  *		 struct ucred *a_cred)
558  */
559 static int
560 msdosfs_write(struct vop_write_args *ap)
561 {
562 	int n;
563 	int croffset;
564 	size_t resid;
565 	u_long osize;
566 	int error = 0;
567 	u_long count;
568 	daddr_t cn, lastcn;
569 	struct buf *bp;
570 	int ioflag = ap->a_ioflag;
571 	struct uio *uio = ap->a_uio;
572 	struct thread *td = uio->uio_td;
573 	struct vnode *vp = ap->a_vp;
574 	struct vnode *thisvp;
575 	struct denode *dep = VTODE(vp);
576 	struct msdosfsmount *pmp = dep->de_pmp;
577 	struct proc *p = (td ? td->td_proc : NULL);
578 	struct lwp *lp = (td ? td->td_lwp : NULL);
579 
580 	mprintf("msdosfs_write(vp %p, uio %p, ioflag %x, cred %p\n",
581 	    vp, uio, ioflag, ap->a_cred);
582 	mprintf("msdosfs_write(): diroff %lu, dirclust %lu, startcluster %lu\n",
583 	    dep->de_diroffset, dep->de_dirclust, dep->de_StartCluster);
584 
585 	switch (vp->v_type) {
586 	case VREG:
587 		if (ioflag & IO_APPEND)
588 			uio->uio_offset = dep->de_FileSize;
589 		thisvp = vp;
590 		break;
591 	case VDIR:
592 		return EISDIR;
593 	default:
594 		panic("msdosfs_write(): bad file type");
595 	}
596 
597 	if (uio->uio_offset < 0)
598 		return (EFBIG);
599 
600 	if (uio->uio_resid == 0)
601 		return (0);
602 
603 	/*
604 	 * If they've exceeded their filesize limit, tell them about it.
605 	 */
606 	if (p &&
607 	    ((uoff_t)uio->uio_offset + uio->uio_resid >
608 	    p->p_rlimit[RLIMIT_FSIZE].rlim_cur)) {
609 		lwpsignal(p, lp, SIGXFSZ);
610 		return (EFBIG);
611 	}
612 
613 	if ((uoff_t)uio->uio_offset > DOS_FILESIZE_MAX)
614                 return (EFBIG);
615 	if ((uoff_t)uio->uio_offset + uio->uio_resid > DOS_FILESIZE_MAX)
616                 return (EFBIG);
617 
618 	/*
619 	 * If the offset we are starting the write at is beyond the end of
620 	 * the file, then they've done a seek.  Unix filesystems allow
621 	 * files with holes in them, DOS doesn't so we must fill the hole
622 	 * with zeroed blocks.
623 	 */
624 	if (uio->uio_offset > dep->de_FileSize) {
625 		error = deextend(dep, uio->uio_offset);
626 		if (error)
627 			return (error);
628 	}
629 
630 	/*
631 	 * Remember some values in case the write fails.
632 	 */
633 	resid = uio->uio_resid;
634 	osize = dep->de_FileSize;
635 
636 	/*
637 	 * If we write beyond the end of the file, extend it to its ultimate
638 	 * size ahead of the time to hopefully get a contiguous area.
639 	 */
640 	if (uio->uio_offset + resid > osize) {
641 		count = de_clcount(pmp, uio->uio_offset + resid) -
642 			de_clcount(pmp, osize);
643 		error = extendfile(dep, count, NULL, NULL, 0);
644 		if (error &&  (error != ENOSPC || (ioflag & IO_UNIT)))
645 			goto errexit;
646 		lastcn = dep->de_fc[FC_LASTFC].fc_frcn;
647 	} else
648 		lastcn = de_clcount(pmp, osize) - 1;
649 
650 	do {
651 		if (de_off2cn(pmp, uio->uio_offset) > lastcn) {
652 			error = ENOSPC;
653 			break;
654 		}
655 
656 		croffset = uio->uio_offset & pmp->pm_crbomask;
657 		n = (int)szmin(uio->uio_resid, pmp->pm_bpcluster - croffset);
658 		if (uio->uio_offset + n > dep->de_FileSize) {
659 			dep->de_FileSize = uio->uio_offset + n;
660 			/* The object size needs to be set before buffer is allocated */
661 			vnode_pager_setsize(vp, dep->de_FileSize);
662 		}
663 
664 		/*
665 		 * If either the whole cluster gets written, or we write
666 		 * the cluster from its start beyond EOF, then no need to
667 		 * read data from disk.
668 		 *
669 		 * If UIO_NOCOPY is set we have to do a read-before-write
670 		 * to fill in any missing pieces of the buffer since no
671 		 * actual overwrite will occur.
672 		 */
673 		cn = de_off2cn(pmp, uio->uio_offset);
674 		if ((uio->uio_offset & pmp->pm_crbomask) == 0
675 		    && uio->uio_segflg != UIO_NOCOPY
676 		    && (de_off2cn(pmp, uio->uio_offset + uio->uio_resid)
677 		        > de_off2cn(pmp, uio->uio_offset)
678 			|| uio->uio_offset + uio->uio_resid >= dep->de_FileSize)) {
679 			bp = getblk(thisvp, de_cn2doff(pmp, cn),
680 				    pmp->pm_bpcluster, 0, 0);
681 			clrbuf(bp);
682 			/*
683 			 * Do the bmap now, since pcbmap needs buffers
684 			 * for the fat table. (see msdosfs_strategy)
685 			 */
686 			if (bp->b_bio2.bio_offset == NOOFFSET) {
687 				daddr_t lblkno = de_off2cn(pmp, bp->b_loffset);
688 				daddr_t dblkno;
689 
690 				error = pcbmap(dep, lblkno,
691 					       &dblkno, NULL, NULL);
692 				if (error || dblkno == (daddr_t)-1) {
693 					bp->b_bio2.bio_offset = NOOFFSET;
694 				} else {
695 					bp->b_bio2.bio_offset = de_bntodoff(pmp,
696 					    dblkno);
697 				}
698 			}
699 			if (bp->b_bio2.bio_offset == NOOFFSET) {
700 				brelse(bp);
701 				if (!error)
702 					error = EIO;		/* XXX */
703 				break;
704 			}
705 		} else {
706 			/*
707 			 * The block we need to write into exists, so read
708 			 * it in.
709 			 */
710 			error = bread(thisvp, de_cn2doff(pmp, cn),
711 				      pmp->pm_bpcluster, &bp);
712 			if (error) {
713 				brelse(bp);
714 				break;
715 			}
716 		}
717 
718 		/*
719 		 * Should these vnode_pager_* functions be done on dir
720 		 * files?
721 		 */
722 
723 		/*
724 		 * Copy the data from user space into the buf header.
725 		 */
726 		error = uiomovebp(bp, bp->b_data + croffset, (size_t)n, uio);
727 		if (error) {
728 			brelse(bp);
729 			break;
730 		}
731 
732 		/*
733 		 * If they want this synchronous then write it and wait for
734 		 * it.  Otherwise, if on a cluster boundary write it
735 		 * asynchronously so we can move on to the next block
736 		 * without delay.  Otherwise do a delayed write because we
737 		 * may want to write somemore into the block later.
738 		 */
739 		if (ioflag & IO_SYNC)
740 			bwrite(bp);
741 		else if (n + croffset == pmp->pm_bpcluster)
742 			bawrite(bp);
743 		else
744 			bdwrite(bp);
745 		dep->de_flag |= DE_UPDATE;
746 	} while (error == 0 && uio->uio_resid > 0);
747 
748 	/*
749 	 * If the write failed and they want us to, truncate the file back
750 	 * to the size it was before the write was attempted.
751 	 */
752 errexit:
753 	if (error) {
754 		if (ioflag & IO_UNIT) {
755 			detrunc(dep, osize, ioflag & IO_SYNC);
756 			uio->uio_offset -= resid - uio->uio_resid;
757 			uio->uio_resid = resid;
758 		} else {
759 			detrunc(dep, dep->de_FileSize, ioflag & IO_SYNC);
760 			if (uio->uio_resid != resid)
761 				error = 0;
762 		}
763 	} else if (ioflag & IO_SYNC)
764 		error = deupdat(dep, 1);
765 	return (error);
766 }
767 
768 /*
769  * Flush the blocks of a file to disk.
770  *
771  * This function is worthless for vnodes that represent directories. Maybe we
772  * could just do a sync if they try an fsync on a directory file.
773  *
774  * msdosfs_fsync(struct vnode *a_vp, int a_waitfor)
775  */
776 static int
777 msdosfs_fsync(struct vop_fsync_args *ap)
778 {
779 	struct vnode *vp = ap->a_vp;
780 
781 	/*
782 	 * Flush all dirty buffers associated with a vnode.
783 	 */
784 #ifdef DIAGNOSTIC
785 loop:
786 #endif
787 	vfsync(vp, ap->a_waitfor, 0, NULL, NULL);
788 #ifdef DIAGNOSTIC
789 	if (ap->a_waitfor == MNT_WAIT && !RB_EMPTY(&vp->v_rbdirty_tree)) {
790 		vprint("msdosfs_fsync: dirty", vp);
791 		goto loop;
792 	}
793 #endif
794 	return (deupdat(VTODE(vp), ap->a_waitfor == MNT_WAIT));
795 }
796 
797 /*
798  * msdosfs_remove(struct vnode *a_dvp, struct vnode *a_vp,
799  *		  struct componentname *a_cnp)
800  */
801 static int
802 msdosfs_remove(struct vop_old_remove_args *ap)
803 {
804 	struct denode *dep = VTODE(ap->a_vp);
805 	struct denode *ddep = VTODE(ap->a_dvp);
806 	int error;
807 
808 	if (ap->a_vp->v_type == VDIR)
809 		error = EPERM;
810 	else
811 		error = removede(ddep, dep);
812 	mprintf("msdosfs_remove(), dep %p, v_refcnt 0x%08x\n",
813 		dep, ap->a_vp->v_refcnt);
814 	return (error);
815 }
816 
817 /*
818  * DOS filesystems don't know what links are. But since we already called
819  * msdosfs_lookup() with create and lockparent, the parent is locked so we
820  * have to free it before we return the error.
821  *
822  * msdosfs_link(struct vnode *a_tdvp, struct vnode *a_vp,
823  *		struct componentname *a_cnp)
824  */
825 static int
826 msdosfs_link(struct vop_old_link_args *ap)
827 {
828 	return (EOPNOTSUPP);
829 }
830 
831 /*
832  * Renames on files require moving the denode to a new hash queue since the
833  * denode's location is used to compute which hash queue to put the file
834  * in. Unless it is a rename in place.  For example "mv a b".
835  *
836  * What follows is the basic algorithm:
837  *
838  * if (file move) {
839  *	if (dest file exists) {
840  *		remove dest file
841  *	}
842  *	if (dest and src in same directory) {
843  *		rewrite name in existing directory slot
844  *	} else {
845  *		write new entry in dest directory
846  *		update offset and dirclust in denode
847  *		move denode to new hash chain
848  *		clear old directory entry
849  *	}
850  * } else {
851  *	directory move
852  *	if (dest directory exists) {
853  *		if (dest is not empty) {
854  *			return ENOTEMPTY
855  *		}
856  *		remove dest directory
857  *	}
858  *	if (dest and src in same directory) {
859  *		rewrite name in existing entry
860  *	} else {
861  *		be sure dest is not a child of src directory
862  *		write entry in dest directory
863  *		update "." and ".." in moved directory
864  *		clear old directory entry for moved directory
865  *	}
866  * }
867  *
868  * On entry:
869  *	source's parent directory is unlocked
870  *	source file or directory is unlocked
871  *	destination's parent directory is locked
872  *	destination file or directory is locked if it exists
873  *
874  * On exit:
875  *	all denodes should be released
876  *
877  * Notes:
878  * I'm not sure how the memory containing the pathnames pointed at by the
879  * componentname structures is freed, there may be some memory bleeding
880  * for each rename done.
881  *
882  * msdosfs_rename(struct vnode *a_fdvp, struct vnode *a_fvp,
883  *		  struct componentname *a_fcnp, struct vnode *a_tdvp,
884  *		  struct vnode *a_tvp, struct componentname *a_tcnp)
885  */
886 static int
887 msdosfs_rename(struct vop_old_rename_args *ap)
888 {
889 	struct vnode *tdvp = ap->a_tdvp;
890 	struct vnode *fvp = ap->a_fvp;
891 	struct vnode *fdvp = ap->a_fdvp;
892 	struct vnode *tvp = ap->a_tvp;
893 	struct componentname *tcnp = ap->a_tcnp;
894 	struct componentname *fcnp = ap->a_fcnp;
895 	struct denode *ip, *xp, *dp, *zp;
896 	u_char toname[11], oldname[11];
897 	u_long from_diroffset, to_diroffset;
898 	u_char to_count;
899 	int doingdirectory = 0, newparent = 0;
900 	int error;
901 	u_long cn;
902 	daddr_t bn;
903 	struct msdosfsmount *pmp;
904 	struct direntry *dotdotp;
905 	struct buf *bp;
906 
907 	pmp = VFSTOMSDOSFS(fdvp->v_mount);
908 
909 	/*
910 	 * Check for cross-device rename.
911 	 */
912 	if ((fvp->v_mount != tdvp->v_mount) ||
913 	    (tvp && (fvp->v_mount != tvp->v_mount))) {
914 		error = EXDEV;
915 abortit:
916 		if (tdvp == tvp)
917 			vrele(tdvp);
918 		else
919 			vput(tdvp);
920 		if (tvp)
921 			vput(tvp);
922 		vrele(fdvp);
923 		vrele(fvp);
924 		return (error);
925 	}
926 
927 	/*
928 	 * If source and dest are the same, do nothing.
929 	 */
930 	if (tvp == fvp) {
931 		error = 0;
932 		goto abortit;
933 	}
934 
935 	/*
936 	 * fvp, fdvp are unlocked, tvp, tdvp are locked.  Lock fvp and note
937 	 * that we have to unlock it to use the abortit target.
938 	 */
939 	error = vn_lock(fvp, LK_EXCLUSIVE | LK_FAILRECLAIM);
940 	if (error)
941 		goto abortit;
942 	dp = VTODE(fdvp);
943 	ip = VTODE(fvp);
944 
945 	/*
946 	 * Be sure we are not renaming ".", "..", or an alias of ".". This
947 	 * leads to a crippled directory tree.  It's pretty tough to do a
948 	 * "ls" or "pwd" with the "." directory entry missing, and "cd .."
949 	 * doesn't work if the ".." entry is missing.
950 	 */
951 	if (ip->de_Attributes & ATTR_DIRECTORY) {
952 		/*
953 		 * Avoid ".", "..", and aliases of "." for obvious reasons.
954 		 */
955 		if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
956 		    dp == ip ||
957 		    (fcnp->cn_flags & CNP_ISDOTDOT) ||
958 		    (tcnp->cn_flags & CNP_ISDOTDOT) ||
959 		    (ip->de_flag & DE_RENAME)) {
960 			vn_unlock(fvp);
961 			error = EINVAL;
962 			goto abortit;
963 		}
964 		ip->de_flag |= DE_RENAME;
965 		doingdirectory++;
966 	}
967 
968 	/*
969 	 * fvp locked, fdvp unlocked, tvp, tdvp locked.  DE_RENAME only
970 	 * set if doingdirectory.  We will get fvp unlocked in fairly
971 	 * short order.  dp and xp must be setup and fvp must be unlocked
972 	 * for the out and bad targets to work properly.
973 	 */
974 	dp = VTODE(tdvp);
975 	xp = tvp ? VTODE(tvp) : NULL;
976 
977 	/*
978 	 * Remember direntry place to use for destination
979 	 */
980 	to_diroffset = dp->de_fndoffset;
981 	to_count = dp->de_fndcnt;
982 
983 	/*
984 	 * If ".." must be changed (ie the directory gets a new
985 	 * parent) then the source directory must not be in the
986 	 * directory heirarchy above the target, as this would
987 	 * orphan everything below the source directory. Also
988 	 * the user must have write permission in the source so
989 	 * as to be able to change "..". We must repeat the call
990 	 * to namei, as the parent directory is unlocked by the
991 	 * call to doscheckpath().
992 	 */
993 	error = VOP_EACCESS(fvp, VWRITE, tcnp->cn_cred);
994 	vn_unlock(fvp);
995 	if (VTODE(fdvp)->de_StartCluster != VTODE(tdvp)->de_StartCluster)
996 		newparent = 1;
997 
998 	/*
999 	 * ok. fvp, fdvp unlocked, tvp, tdvp locked. tvp may be NULL.
1000 	 * DE_RENAME only set if doingdirectory.
1001 	 */
1002 	if (doingdirectory && newparent) {
1003 		if (error)	/* write access check above */
1004 			goto bad;
1005 		if (xp != NULL) {
1006 			vput(tvp);
1007 			xp = NULL;
1008 		}
1009 		/*
1010 		 * checkpath vput's tdvp (VTOI(dp)) on return no matter what,
1011 		 * get an extra ref so we wind up with just an unlocked, ref'd
1012 		 * tdvp.  The 'out' target skips tvp and tdvp cleanups (tdvp
1013 		 * isn't locked so we can't use the out target).
1014 		 */
1015 		vref(tdvp);
1016 		error = doscheckpath(ip, dp);
1017 		tcnp->cn_flags |= CNP_PDIRUNLOCK;
1018 		if (error) {
1019 			vrele(tdvp);
1020 			goto out;
1021 		}
1022 		/*
1023 		 * relookup no longer messes with the ref count.  tdvp must
1024 		 * be unlocked on entry and on success will be locked on
1025 		 * return.
1026 		 */
1027 		error = relookup(tdvp, &tvp, tcnp);
1028 		if (error) {
1029 			if (tcnp->cn_flags & CNP_PDIRUNLOCK)
1030 				vrele(tdvp);
1031 			else
1032 				vput(tdvp);
1033 			goto out;
1034 		}
1035 
1036 		/*
1037 		 * tvp and tdvp are now locked again.
1038 		 */
1039 		dp = VTODE(tdvp);
1040 		xp = tvp ? VTODE(tvp) : NULL;
1041 	}
1042 
1043 	/*
1044 	 * tvp and tdvp are now locked again, the 'bad' target can be used
1045 	 * to clean them up again.  Delete an existant target and clean
1046 	 * up tvp.  Set xp to NULL to indicate that tvp has been cleaned up.
1047 	 */
1048 	if (xp != NULL) {
1049 		/*
1050 		 * Target must be empty if a directory and have no links
1051 		 * to it. Also, ensure source and target are compatible
1052 		 * (both directories, or both not directories).
1053 		 */
1054 		if (xp->de_Attributes & ATTR_DIRECTORY) {
1055 			if (!dosdirempty(xp)) {
1056 				error = ENOTEMPTY;
1057 				goto bad;
1058 			}
1059 			if (!doingdirectory) {
1060 				error = ENOTDIR;
1061 				goto bad;
1062 			}
1063 		} else if (doingdirectory) {
1064 			error = EISDIR;
1065 			goto bad;
1066 		}
1067 		error = removede(dp, xp);
1068 		if (error)
1069 			goto bad;
1070 		vput(tvp);
1071 		xp = NULL;
1072 		tvp = NULL;
1073 	}
1074 
1075 	/*
1076 	 * Convert the filename in tcnp into a dos filename. We copy this
1077 	 * into the denode and directory entry for the destination
1078 	 * file/directory.
1079 	 */
1080 	error = uniqdosname(VTODE(tdvp), tcnp, toname);
1081 	if (error)
1082 		goto bad;
1083 
1084 	/*
1085 	 * Since from wasn't locked at various places above, we have to do
1086 	 * a relookup here.  If the target and source are the same directory
1087 	 * we have to unlock the target directory in order to safely relookup
1088 	 * the source, because relookup expects its directory to be unlocked.
1089 	 *
1090 	 * Note that ap->a_fvp is still valid and ref'd.  Any cleanup must
1091 	 * now take that into account.
1092 	 *
1093 	 * The tdvp locking issues make this a real mess.
1094 	 */
1095 	fcnp->cn_flags &= ~CNP_MODMASK;
1096 	fcnp->cn_flags |= CNP_LOCKPARENT;
1097 	if (newparent == 0)
1098 		vn_unlock(tdvp);
1099 	error = relookup(fdvp, &fvp, fcnp);
1100 	if (error || fvp == NULL) {
1101 		/*
1102 		 * From name has disappeared.  Note: fdvp might == tdvp.
1103 		 *
1104 		 * DE_RENAME is only set if doingdirectory.
1105 		 */
1106 		if (doingdirectory)
1107 			panic("rename: lost dir entry");
1108 		if (fcnp->cn_flags & CNP_PDIRUNLOCK)
1109 			vrele(fdvp);
1110 		else
1111 			vput(fdvp);
1112 		if (newparent == 0)
1113 			vrele(tdvp);
1114 		else
1115 			vput(tdvp);
1116 		vrele(ap->a_fvp);
1117 		return(0);
1118 	}
1119 
1120 	/*
1121 	 * No error occured.  tdvp, fdvp and fvp are all locked.  If
1122 	 * newparent was 0 be aware that fdvp == tdvp.  tvp has been cleaned
1123 	 * up.  ap->a_fvp is still refd.
1124 	 */
1125 	xp = VTODE(fvp);
1126 	zp = VTODE(fdvp);
1127 	from_diroffset = zp->de_fndoffset;
1128 
1129 	/*
1130 	 * Ensure that the directory entry still exists and has not
1131 	 * changed till now. If the source is a file the entry may
1132 	 * have been unlinked or renamed. In either case there is
1133 	 * no further work to be done. If the source is a directory
1134 	 * then it cannot have been rmdir'ed or renamed; this is
1135 	 * prohibited by the DE_RENAME flag.
1136 	 *
1137 	 * DE_RENAME is only set if doingdirectory.
1138 	 */
1139 	if (xp != ip) {
1140 		if (doingdirectory)
1141 			panic("rename: lost dir entry");
1142 		goto done;
1143 	} else {
1144 		u_long new_dirclust;
1145 		u_long new_diroffset;
1146 
1147 		/*
1148 		 * First write a new entry in the destination
1149 		 * directory and mark the entry in the source directory
1150 		 * as deleted.  Then move the denode to the correct hash
1151 		 * chain for its new location in the filesystem.  And, if
1152 		 * we moved a directory, then update its .. entry to point
1153 		 * to the new parent directory.
1154 		 */
1155 		bcopy(ip->de_Name, oldname, 11);
1156 		bcopy(toname, ip->de_Name, 11);	/* update denode */
1157 		dp->de_fndoffset = to_diroffset;
1158 		dp->de_fndcnt = to_count;
1159 		error = createde(ip, dp, NULL, tcnp);
1160 		if (error) {
1161 			bcopy(oldname, ip->de_Name, 11);
1162 			goto done;
1163 		}
1164 		ip->de_refcnt++;
1165 		zp->de_fndoffset = from_diroffset;
1166 		error = removede(zp, ip);
1167 		if (error) {
1168 			/* XXX should really panic here, fs is corrupt */
1169 			goto done;
1170 		}
1171 		if (!doingdirectory) {
1172 			error = pcbmap(dp, de_cluster(pmp, to_diroffset),
1173 				       NULL, &new_dirclust, NULL);
1174 			if (error) {
1175 				/* XXX should really panic here, fs is corrupt */
1176 				goto done;
1177 			}
1178 			if (new_dirclust == MSDOSFSROOT)
1179 				new_diroffset = to_diroffset;
1180 			else
1181 				new_diroffset = to_diroffset & pmp->pm_crbomask;
1182 			msdosfs_reinsert(ip, new_dirclust, new_diroffset);
1183 		}
1184 	}
1185 
1186 	/*
1187 	 * If we moved a directory to a new parent directory, then we must
1188 	 * fixup the ".." entry in the moved directory.
1189 	 */
1190 	if (doingdirectory && newparent) {
1191 		cn = ip->de_StartCluster;
1192 		if (cn == MSDOSFSROOT) {
1193 			/* this should never happen */
1194 			panic("msdosfs_rename(): updating .. in root directory?");
1195 		} else {
1196 			bn = xcntobn(pmp, cn);
1197 		}
1198 		error = bread(pmp->pm_devvp, de_bntodoff(pmp, bn),
1199 			      pmp->pm_bpcluster, &bp);
1200 		if (error) {
1201 			/* XXX should really panic here, fs is corrupt */
1202 			brelse(bp);
1203 			goto done;
1204 		}
1205 		dotdotp = (struct direntry *)bp->b_data + 1;
1206 		putushort(dotdotp->deStartCluster, dp->de_StartCluster);
1207 		if (FAT32(pmp))
1208 			putushort(dotdotp->deHighClust, dp->de_StartCluster >> 16);
1209 		error = bwrite(bp);
1210 		if (error) {
1211 			/* XXX should really panic here, fs is corrupt */
1212 			goto done;
1213 		}
1214 	}
1215 
1216 	/*
1217 	 * done case fvp, fdvp, tdvp are locked.  ap->a_fvp is refd
1218 	 */
1219 done:
1220 	if (doingdirectory)
1221 		ip->de_flag &= ~DE_RENAME;	/* XXX fvp not locked */
1222 	vput(fvp);
1223 	if (newparent)
1224 		vput(fdvp);
1225 	else
1226 		vrele(fdvp);
1227 	vput(tdvp);
1228 	vrele(ap->a_fvp);
1229 	return (error);
1230 
1231 	/*
1232 	 * 'bad' target: xp governs tvp.  tvp and tdvp arel ocked, fdvp and fvp
1233 	 * are not locked.  ip points to fvp's inode which may have DE_RENAME
1234 	 * set.
1235 	 */
1236 bad:
1237 	if (xp)
1238 		vput(tvp);
1239 	vput(tdvp);
1240 out:
1241 	/*
1242 	 * 'out' target: tvp and tdvp have already been cleaned up.
1243 	 */
1244 	if (doingdirectory)
1245 		ip->de_flag &= ~DE_RENAME;
1246 	vrele(fdvp);
1247 	vrele(fvp);
1248 	return (error);
1249 
1250 }
1251 
1252 static struct {
1253 	struct direntry dot;
1254 	struct direntry dotdot;
1255 } dosdirtemplate = {
1256 	{	".          ",				/* the . entry */
1257 		ATTR_DIRECTORY,				/* file attribute */
1258 		0,					/* reserved */
1259 		0, { 0, 0 }, { 0, 0 },			/* create time & date */
1260 		{ 0, 0 },				/* access date */
1261 		{ 0, 0 },				/* high bits of start cluster */
1262 		{ 210, 4 }, { 210, 4 },			/* modify time & date */
1263 		{ 0, 0 },				/* startcluster */
1264 		{ 0, 0, 0, 0 }				/* filesize */
1265 	},
1266 	{	"..         ",				/* the .. entry */
1267 		ATTR_DIRECTORY,				/* file attribute */
1268 		0,					/* reserved */
1269 		0, { 0, 0 }, { 0, 0 },			/* create time & date */
1270 		{ 0, 0 },				/* access date */
1271 		{ 0, 0 },				/* high bits of start cluster */
1272 		{ 210, 4 }, { 210, 4 },			/* modify time & date */
1273 		{ 0, 0 },				/* startcluster */
1274 		{ 0, 0, 0, 0 }				/* filesize */
1275 	}
1276 };
1277 
1278 /*
1279  * msdosfs_mkdir(struct vnode *a_dvp, struct vnode **a_vpp,
1280  *		 struct componentname *a_cnp, struct vattr *a_vap)
1281  */
1282 static int
1283 msdosfs_mkdir(struct vop_old_mkdir_args *ap)
1284 {
1285 	struct componentname *cnp = ap->a_cnp;
1286 	struct denode *dep;
1287 	struct denode *pdep = VTODE(ap->a_dvp);
1288 	struct direntry *denp;
1289 	struct msdosfsmount *pmp = pdep->de_pmp;
1290 	struct buf *bp;
1291 	u_long newcluster, pcl;
1292 	int bn;
1293 	int error;
1294 	struct denode ndirent;
1295 	struct timespec ts;
1296 
1297 	/*
1298 	 * If this is the root directory and there is no space left we
1299 	 * can't do anything.  This is because the root directory can not
1300 	 * change size.
1301 	 */
1302 	if (pdep->de_StartCluster == MSDOSFSROOT
1303 	    && pdep->de_fndoffset >= pdep->de_FileSize) {
1304 		error = ENOSPC;
1305 		goto bad2;
1306 	}
1307 
1308 	/*
1309 	 * Allocate a cluster to hold the about to be created directory.
1310 	 */
1311 	error = clusteralloc(pmp, 0, 1, CLUST_EOFE, &newcluster, NULL);
1312 	if (error)
1313 		goto bad2;
1314 
1315 	bzero(&ndirent, sizeof(ndirent));
1316 	ndirent.de_pmp = pmp;
1317 	ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
1318 	getnanotime(&ts);
1319 	DETIMES(&ndirent, &ts, &ts, &ts);
1320 
1321 	/*
1322 	 * Now fill the cluster with the "." and ".." entries. And write
1323 	 * the cluster to disk.  This way it is there for the parent
1324 	 * directory to be pointing at if there were a crash.
1325 	 */
1326 	bn = xcntobn(pmp, newcluster);
1327 	/* always succeeds */
1328 	bp = getblk(pmp->pm_devvp, de_bntodoff(pmp, bn),
1329 		    pmp->pm_bpcluster, 0, 0);
1330 	bzero(bp->b_data, pmp->pm_bpcluster);
1331 	bcopy(&dosdirtemplate, bp->b_data, sizeof(dosdirtemplate));
1332 	denp = (struct direntry *)bp->b_data;
1333 	putushort(denp[0].deStartCluster, newcluster);
1334 	putushort(denp[0].deCDate, ndirent.de_CDate);
1335 	putushort(denp[0].deCTime, ndirent.de_CTime);
1336 	denp[0].deCHundredth = ndirent.de_CHun;
1337 	putushort(denp[0].deADate, ndirent.de_ADate);
1338 	putushort(denp[0].deMDate, ndirent.de_MDate);
1339 	putushort(denp[0].deMTime, ndirent.de_MTime);
1340 	pcl = pdep->de_StartCluster;
1341 	if (FAT32(pmp) && pcl == pmp->pm_rootdirblk)
1342 		pcl = 0;
1343 	putushort(denp[1].deStartCluster, pcl);
1344 	putushort(denp[1].deCDate, ndirent.de_CDate);
1345 	putushort(denp[1].deCTime, ndirent.de_CTime);
1346 	denp[1].deCHundredth = ndirent.de_CHun;
1347 	putushort(denp[1].deADate, ndirent.de_ADate);
1348 	putushort(denp[1].deMDate, ndirent.de_MDate);
1349 	putushort(denp[1].deMTime, ndirent.de_MTime);
1350 	if (FAT32(pmp)) {
1351 		putushort(denp[0].deHighClust, newcluster >> 16);
1352 		putushort(denp[1].deHighClust, pdep->de_StartCluster >> 16);
1353 	}
1354 
1355 	error = bwrite(bp);
1356 	if (error)
1357 		goto bad;
1358 
1359 	/*
1360 	 * Now build up a directory entry pointing to the newly allocated
1361 	 * cluster.  This will be written to an empty slot in the parent
1362 	 * directory.
1363 	 */
1364 	error = uniqdosname(pdep, cnp, ndirent.de_Name);
1365 	if (error)
1366 		goto bad;
1367 
1368 	ndirent.de_Attributes = ATTR_DIRECTORY;
1369 	ndirent.de_LowerCase = 0;
1370 	ndirent.de_StartCluster = newcluster;
1371 	ndirent.de_FileSize = 0;
1372 	ndirent.de_dev = pdep->de_dev;
1373 	ndirent.de_devvp = pdep->de_devvp;
1374 	error = createde(&ndirent, pdep, &dep, cnp);
1375 	if (error)
1376 		goto bad;
1377 	*ap->a_vpp = DETOV(dep);
1378 	return (0);
1379 
1380 bad:
1381 	clusterfree(pmp, newcluster, NULL);
1382 bad2:
1383 	return (error);
1384 }
1385 
1386 /*
1387  * msdosfs_rmdir(struct vnode *a_dvp, struct vnode *a_vp,
1388  *		 struct componentname *a_cnp)
1389  */
1390 static int
1391 msdosfs_rmdir(struct vop_old_rmdir_args *ap)
1392 {
1393 	struct vnode *vp = ap->a_vp;
1394 	struct vnode *dvp = ap->a_dvp;
1395 	struct denode *ip, *dp;
1396 	int error;
1397 
1398 	ip = VTODE(vp);
1399 	dp = VTODE(dvp);
1400 
1401 	/*
1402 	 * Verify the directory is empty (and valid).
1403 	 * (Rmdir ".." won't be valid since
1404 	 *  ".." will contain a reference to
1405 	 *  the current directory and thus be
1406 	 *  non-empty.)
1407 	 */
1408 	error = 0;
1409 	if (!dosdirempty(ip) || ip->de_flag & DE_RENAME) {
1410 		error = ENOTEMPTY;
1411 		goto out;
1412 	}
1413 	/*
1414 	 * Delete the entry from the directory.  For dos filesystems this
1415 	 * gets rid of the directory entry on disk, the in memory copy
1416 	 * still exists but the de_refcnt is <= 0.  This prevents it from
1417 	 * being found by deget().  When the vput() on dep is done we give
1418 	 * up access and eventually msdosfs_reclaim() will be called which
1419 	 * will remove it from the denode cache.
1420 	 */
1421 	error = removede(dp, ip);
1422 	if (error)
1423 		goto out;
1424 	/*
1425 	 * This is where we decrement the link count in the parent
1426 	 * directory.  Since dos filesystems don't do this we just purge
1427 	 * the name cache.
1428 	 */
1429 	vn_unlock(dvp);
1430 	/*
1431 	 * Truncate the directory that is being deleted.
1432 	 */
1433 	error = detrunc(ip, (u_long)0, IO_SYNC);
1434 
1435 	vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
1436 out:
1437 	return (error);
1438 }
1439 
1440 /*
1441  * DOS filesystems don't know what symlinks are.
1442  *
1443  * msdosfs_symlink(struct vnode *a_dvp, struct vnode **a_vpp,
1444  *		   struct componentname *a_cnp, struct vattr *a_vap,
1445  *		   char *a_target)
1446  */
1447 static int
1448 msdosfs_symlink(struct vop_old_symlink_args *ap)
1449 {
1450 	return (EOPNOTSUPP);
1451 }
1452 
1453 /*
1454  * msdosfs_readdir(struct vnode *a_vp, struct uio *a_uio,
1455  *		   struct ucred *a_cred, int *a_eofflag, int *a_ncookies,
1456  *		   off_t **a_cookies)
1457  */
1458 static int
1459 msdosfs_readdir(struct vop_readdir_args *ap)
1460 {
1461 	struct mbnambuf nb;
1462 	int error = 0;
1463 	int diff;
1464 	long n;
1465 	int blsize;
1466 	long on;
1467 	u_long cn;
1468 	u_long dirsperblk;
1469 	long bias = 0;
1470 	daddr_t bn, lbn;
1471 	struct buf *bp;
1472 	struct denode *dep;
1473 	struct msdosfsmount *pmp;
1474 	struct direntry *dentp;
1475 	struct uio *uio = ap->a_uio;
1476 	off_t *cookies = NULL;
1477 	int ncookies = 0;
1478 	off_t offset, off;
1479 	int chksum = -1;
1480 	ino_t d_ino;
1481 	uint16_t d_namlen;
1482 	uint8_t d_type;
1483 	char *d_name_storage = NULL;
1484 	char *d_name = NULL;
1485 
1486 	error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM);
1487 	if (error)
1488 		return (error);
1489 
1490 	dep = VTODE(ap->a_vp);
1491 	pmp = dep->de_pmp;
1492 
1493 	mprintf("msdosfs_readdir(): vp %p, uio %p, cred %p, eofflagp %p\n",
1494 	    ap->a_vp, uio, ap->a_cred, ap->a_eofflag);
1495 
1496 	/*
1497 	 * msdosfs_readdir() won't operate properly on regular files since
1498 	 * it does i/o only with the the filesystem vnode, and hence can
1499 	 * retrieve the wrong block from the buffer cache for a plain file.
1500 	 * So, fail attempts to readdir() on a plain file.
1501 	 */
1502 	if ((dep->de_Attributes & ATTR_DIRECTORY) == 0) {
1503 		error = ENOTDIR;
1504 		goto done;
1505 	}
1506 
1507 	/*
1508 	 * If the user buffer is smaller than the size of one dos directory
1509 	 * entry or the file offset is not a multiple of the size of a
1510 	 * directory entry, then we fail the read.
1511 	 */
1512 	off = offset = uio->uio_offset;
1513 	if (uio->uio_resid < sizeof(struct direntry) ||
1514 	    (offset & (sizeof(struct direntry) - 1))) {
1515 		error = EINVAL;
1516 		goto done;
1517 	}
1518 
1519 	if (ap->a_ncookies) {
1520 		ncookies = uio->uio_resid / 16 + 1;
1521 		if (ncookies > 1024)
1522 			ncookies = 1024;
1523 		cookies = kmalloc(ncookies * sizeof(off_t), M_TEMP, M_WAITOK);
1524 		*ap->a_cookies = cookies;
1525 		*ap->a_ncookies = ncookies;
1526 	}
1527 
1528 	dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
1529 
1530 	/*
1531 	 * If they are reading from the root directory then, we simulate
1532 	 * the . and .. entries since these don't exist in the root
1533 	 * directory.  We also set the offset bias to make up for having to
1534 	 * simulate these entries. By this I mean that at file offset 64 we
1535 	 * read the first entry in the root directory that lives on disk.
1536 	 */
1537 	if (dep->de_StartCluster == MSDOSFSROOT
1538 	    || (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk)) {
1539 		bias = 2 * sizeof(struct direntry);
1540 		if (offset < bias) {
1541 			for (n = (int)offset / sizeof(struct direntry); n < 2;
1542 			     n++) {
1543 				if (FAT32(pmp))
1544 					d_ino = xcntobn(pmp, pmp->pm_rootdirblk)
1545 					    * dirsperblk;
1546 				else
1547 					d_ino = 1;
1548 				d_type = DT_DIR;
1549 				if (n == 0) {
1550 					d_namlen = 1;
1551 					d_name = ".";
1552 				} else if (n == 1) {
1553 					d_namlen = 2;
1554 					d_name = "..";
1555 				}
1556 				if (vop_write_dirent(&error, uio, d_ino, d_type,
1557 				    d_namlen, d_name))
1558 					goto out;
1559 				if (error)
1560 					goto out;
1561 				offset += sizeof(struct direntry);
1562 				off = offset;
1563 				if (cookies) {
1564 					*cookies++ = offset;
1565 					if (--ncookies <= 0)
1566 						goto out;
1567 				}
1568 			}
1569 		}
1570 	}
1571 
1572 	d_name_storage = kmalloc(WIN_MAXLEN, M_TEMP, M_WAITOK);
1573 	mbnambuf_init(&nb);
1574 	off = offset;
1575 
1576 	while (uio->uio_resid > 0) {
1577 		lbn = de_off2cn(pmp, offset - bias);
1578 		on = (offset - bias) & pmp->pm_crbomask;
1579 		n = szmin(pmp->pm_bpcluster - on, uio->uio_resid);
1580 		diff = dep->de_FileSize - (offset - bias);
1581 		if (diff <= 0)
1582 			break;
1583 		n = min(n, diff);
1584 		error = pcbmap(dep, lbn, &bn, &cn, &blsize);
1585 		if (error)
1586 			break;
1587 		error = bread(pmp->pm_devvp, de_bntodoff(pmp, bn), blsize, &bp);
1588 		if (error) {
1589 			brelse(bp);
1590 			kfree(d_name_storage, M_TEMP);
1591 			goto done;
1592 		}
1593 		n = min(n, blsize - bp->b_resid);
1594 
1595 		/*
1596 		 * Convert from dos directory entries to fs-independent
1597 		 * directory entries.
1598 		 */
1599 		for (dentp = (struct direntry *)(bp->b_data + on);
1600 		     (char *)dentp < bp->b_data + on + n;
1601 		     dentp++, offset += sizeof(struct direntry)) {
1602 			d_name = d_name_storage;
1603 			d_namlen = 0;
1604 			/*
1605 			 * If this is an unused entry, we can stop.
1606 			 */
1607 			if (dentp->deName[0] == SLOT_EMPTY) {
1608 				brelse(bp);
1609 				goto out;
1610 			}
1611 			/*
1612 			 * Skip deleted entries.
1613 			 */
1614 			if (dentp->deName[0] == SLOT_DELETED) {
1615 				chksum = -1;
1616 				mbnambuf_init(&nb);
1617 				continue;
1618 			}
1619 			/*
1620 			 * Handle Win95 long directory entries
1621 			 */
1622 			if (dentp->deAttributes == ATTR_WIN95) {
1623 				if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
1624 					continue;
1625 				chksum = win2unixfn(&nb,
1626 					(struct winentry *)dentp,
1627 					chksum, pmp);
1628 				continue;
1629 			}
1630 
1631 			/*
1632 			 * Skip volume labels
1633 			 */
1634 			if (dentp->deAttributes & ATTR_VOLUME) {
1635 				chksum = -1;
1636 				mbnambuf_init(&nb);
1637 				continue;
1638 			}
1639 			/*
1640 			 * This computation of d_ino must match
1641 			 * the computation of va_fileid in
1642 			 * msdosfs_getattr.
1643 			 */
1644 			if (dentp->deAttributes & ATTR_DIRECTORY) {
1645 				d_ino = getushort(dentp->deStartCluster);
1646 				if (FAT32(pmp))
1647 					d_ino |= getushort(dentp->deHighClust) << 16;
1648 				/* if this is the root directory */
1649 				if (d_ino != MSDOSFSROOT)
1650 					d_ino = xcntobn(pmp, d_ino) * dirsperblk;
1651 				else if (FAT32(pmp))
1652 					d_ino = xcntobn(pmp, pmp->pm_rootdirblk)
1653 					    * dirsperblk;
1654 				else
1655 					d_ino = 1;
1656 				d_type = DT_DIR;
1657 			} else {
1658 				d_ino = offset / sizeof(struct direntry);
1659 				d_type = DT_REG;
1660 			}
1661 			if (chksum != winChksum(dentp->deName)) {
1662 				d_namlen = dos2unixfn(dentp->deName,
1663 				    (u_char *)d_name,
1664 				    dentp->deLowerCase |
1665 					((pmp->pm_flags & MSDOSFSMNT_SHORTNAME) ?
1666 					(LCASE_BASE | LCASE_EXT) : 0),
1667 					pmp);
1668 				mbnambuf_init(&nb);
1669 			} else {
1670 				mbnambuf_flush(&nb, d_name, &d_namlen);
1671 			}
1672 			chksum = -1;
1673 			if (vop_write_dirent(&error, uio, d_ino, d_type,
1674 			    d_namlen, d_name)) {
1675 				brelse(bp);
1676 				goto out;
1677 			}
1678 			if (error) {
1679 				brelse(bp);
1680 				goto out;
1681 			}
1682 
1683 			if (cookies) {
1684 				*cookies++ = offset + sizeof(struct direntry);
1685 				if (--ncookies <= 0) {
1686 					brelse(bp);
1687 					goto out;
1688 				}
1689 			}
1690 			off = offset + sizeof(struct direntry);
1691 		}
1692 		brelse(bp);
1693 	}
1694 out:
1695 	if (d_name_storage != NULL)
1696 		kfree(d_name_storage, M_TEMP);
1697 
1698 	/* Subtract unused cookies */
1699 	if (ap->a_ncookies)
1700 		*ap->a_ncookies -= ncookies;
1701 
1702 	uio->uio_offset = off;
1703 
1704 	/*
1705 	 * Set the eofflag (NFS uses it)
1706 	 */
1707 	if (ap->a_eofflag) {
1708 		if (dep->de_FileSize - (offset - bias) <= 0)
1709 			*ap->a_eofflag = 1;
1710 		else
1711 			*ap->a_eofflag = 0;
1712 	}
1713 done:
1714 	vn_unlock(ap->a_vp);
1715 	return (error);
1716 }
1717 
1718 /*
1719  * vp  - address of vnode file the file
1720  * bn  - which cluster we are interested in mapping to a filesystem block number.
1721  * vpp - returns the vnode for the block special file holding the filesystem
1722  *	 containing the file of interest
1723  * bnp - address of where to return the filesystem relative block number
1724  *
1725  * msdosfs_bmap(struct vnode *a_vp, off_t a_loffset,
1726  *		off_t *a_doffsetp, int *a_runp, int *a_runb)
1727  */
1728 static int
1729 msdosfs_bmap(struct vop_bmap_args *ap)
1730 {
1731 	struct denode *dep = VTODE(ap->a_vp);
1732 	struct msdosfsmount *pmp = dep->de_pmp;
1733 	daddr_t lbn;
1734 	daddr_t dbn;
1735 	int error;
1736 
1737 	if (ap->a_doffsetp == NULL)
1738 		return (0);
1739 	if (ap->a_runp) {
1740 		/*
1741 		 * Sequential clusters should be counted here.
1742 		 */
1743 		*ap->a_runp = 0;
1744 	}
1745 	if (ap->a_runb) {
1746 		*ap->a_runb = 0;
1747 	}
1748 	KKASSERT(((int)ap->a_loffset & ((1 << pmp->pm_cnshift) - 1)) == 0);
1749 	lbn = de_off2cn(pmp, ap->a_loffset);
1750 	error = pcbmap(dep, lbn, &dbn, NULL, NULL);
1751 	if (error || dbn == (daddr_t)-1) {
1752 		*ap->a_doffsetp = NOOFFSET;
1753 	} else {
1754 		*ap->a_doffsetp = de_bntodoff(pmp, dbn);
1755 	}
1756 	return (error);
1757 }
1758 
1759 /*
1760  * msdosfs_strategy(struct vnode *a_vp, struct bio *a_bio)
1761  */
1762 static int
1763 msdosfs_strategy(struct vop_strategy_args *ap)
1764 {
1765 	struct bio *bio = ap->a_bio;
1766 	struct bio *nbio;
1767 	struct buf *bp = bio->bio_buf;
1768 	struct vnode *vp = ap->a_vp;
1769 	struct denode *dep = VTODE(vp);
1770 	struct msdosfsmount *pmp = dep->de_pmp;
1771 	int error = 0;
1772 	daddr_t dblkno;
1773 
1774 	if (vp->v_type == VBLK || vp->v_type == VCHR)
1775 		panic("msdosfs_strategy: spec");
1776 	/*
1777 	 * If we don't already know the filesystem relative block number
1778 	 * then get it using pcbmap().  If pcbmap() returns the block
1779 	 * number as -1 then we've got a hole in the file.  DOS filesystems
1780 	 * don't allow files with holes, so we shouldn't ever see this.
1781 	 */
1782 	nbio = push_bio(bio);
1783 	if (nbio->bio_offset == NOOFFSET) {
1784 		error = pcbmap(dep, de_off2cn(pmp, bio->bio_offset),
1785 			       &dblkno, NULL, NULL);
1786 		if (error) {
1787 			bp->b_error = error;
1788 			bp->b_flags |= B_ERROR;
1789 			/* I/O was never started on nbio, must biodone(bio) */
1790 			biodone(bio);
1791 			return (error);
1792 		}
1793 		if (dblkno == (daddr_t)-1) {
1794 			nbio->bio_offset = NOOFFSET;
1795 			vfs_bio_clrbuf(bp);
1796 		} else {
1797 			nbio->bio_offset = de_bntodoff(pmp, dblkno);
1798 		}
1799 	}
1800 	if (nbio->bio_offset == NOOFFSET) {
1801 		/* I/O was never started on nbio, must biodone(bio) */
1802 		biodone(bio);
1803 		return (0);
1804 	}
1805 	/*
1806 	 * Read/write the block from/to the disk that contains the desired
1807 	 * file block.
1808 	 */
1809 	vn_strategy(dep->de_devvp, nbio);
1810 	return (0);
1811 }
1812 
1813 /*
1814  * msdosfs_print(struct vnode *vp)
1815  */
1816 static int
1817 msdosfs_print(struct vop_print_args *ap)
1818 {
1819 	struct denode *dep = VTODE(ap->a_vp);
1820 
1821 	kprintf("tag VT_MSDOSFS, startcluster %lu, dircluster %lu, "
1822 		"diroffset %lu, dev %d, %d",
1823 		dep->de_StartCluster, dep->de_dirclust, dep->de_diroffset,
1824 		major(dep->de_dev), minor(dep->de_dev));
1825 	lockmgr_printinfo(&ap->a_vp->v_lock);
1826 	return (0);
1827 }
1828 
1829 /*
1830  * msdosfs_pathconf(struct vnode *a_vp, int a_name, int *a_retval)
1831  */
1832 static int
1833 msdosfs_pathconf(struct vop_pathconf_args *ap)
1834 {
1835 	struct msdosfsmount *pmp = VTODE(ap->a_vp)->de_pmp;
1836 
1837 	switch (ap->a_name) {
1838 	case _PC_CHOWN_RESTRICTED:
1839 		*ap->a_retval = 1;
1840 		return (0);
1841 	case _PC_FILESIZEBITS:
1842 		*ap->a_retval = FAT12(pmp) ? 32 : 33;
1843 		return (0);
1844 	case _PC_LINK_MAX:
1845 		*ap->a_retval = 1;
1846 		return (0);
1847 	case _PC_NAME_MAX:
1848 		*ap->a_retval =
1849 		    pmp->pm_flags & MSDOSFSMNT_LONGNAME ? WIN_MAXLEN : 12;
1850 		return (0);
1851 	case _PC_NO_TRUNC:
1852 		*ap->a_retval = 0;
1853 		return (0);
1854 	case _PC_PATH_MAX:
1855 		*ap->a_retval = PATH_MAX;
1856 		return (0);
1857 	default:
1858 		return (EINVAL);
1859 	}
1860 	/* NOTREACHED */
1861 }
1862 
1863 /* Global vfs data structures for msdosfs */
1864 struct vop_ops msdosfs_vnode_vops = {
1865 	.vop_default =		vop_defaultop,
1866 	.vop_access =		msdosfs_access,
1867 	.vop_bmap =		msdosfs_bmap,
1868 	.vop_old_lookup =	msdosfs_lookup,
1869 	.vop_open =		msdosfs_open,
1870 	.vop_close =		msdosfs_close,
1871 	.vop_old_create =	msdosfs_create,
1872 	.vop_fsync =		msdosfs_fsync,
1873 	.vop_getattr =		msdosfs_getattr,
1874 	.vop_inactive =		msdosfs_inactive,
1875 	.vop_old_link =		msdosfs_link,
1876 	.vop_old_mkdir =	msdosfs_mkdir,
1877 	.vop_old_mknod =	msdosfs_mknod,
1878 	.vop_pathconf =		msdosfs_pathconf,
1879 	.vop_print =		msdosfs_print,
1880 	.vop_read =		msdosfs_read,
1881 	.vop_readdir =		msdosfs_readdir,
1882 	.vop_reclaim =		msdosfs_reclaim,
1883 	.vop_old_remove =	msdosfs_remove,
1884 	.vop_old_rename =	msdosfs_rename,
1885 	.vop_old_rmdir =	msdosfs_rmdir,
1886 	.vop_setattr =		msdosfs_setattr,
1887 	.vop_strategy =		msdosfs_strategy,
1888 	.vop_old_symlink =	msdosfs_symlink,
1889 	.vop_write =		msdosfs_write,
1890 	.vop_getpages =		vop_stdgetpages,
1891 	.vop_putpages =		vop_stdputpages
1892 };
1893