xref: /freebsd/sys/fs/msdosfs/msdosfs_vnops.c (revision 77a0943ded95b9e6438f7db70c4a28e4d93946d4)
1 /* $FreeBSD$ */
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/namei.h>
54 #include <sys/resourcevar.h>	/* defines plimit structure in proc struct */
55 #include <sys/kernel.h>
56 #include <sys/stat.h>
57 #include <sys/bio.h>
58 #include <sys/buf.h>
59 #include <sys/proc.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/vnode_pager.h>
70 
71 #include <machine/mutex.h>
72 
73 #include <msdosfs/bpb.h>
74 #include <msdosfs/direntry.h>
75 #include <msdosfs/denode.h>
76 #include <msdosfs/msdosfsmount.h>
77 #include <msdosfs/fat.h>
78 
79 #define	DOS_FILESIZE_MAX	0xffffffff
80 
81 /*
82  * Prototypes for MSDOSFS vnode operations
83  */
84 static int msdosfs_create __P((struct vop_create_args *));
85 static int msdosfs_mknod __P((struct vop_mknod_args *));
86 static int msdosfs_close __P((struct vop_close_args *));
87 static int msdosfs_access __P((struct vop_access_args *));
88 static int msdosfs_getattr __P((struct vop_getattr_args *));
89 static int msdosfs_setattr __P((struct vop_setattr_args *));
90 static int msdosfs_read __P((struct vop_read_args *));
91 static int msdosfs_write __P((struct vop_write_args *));
92 static int msdosfs_fsync __P((struct vop_fsync_args *));
93 static int msdosfs_remove __P((struct vop_remove_args *));
94 static int msdosfs_link __P((struct vop_link_args *));
95 static int msdosfs_rename __P((struct vop_rename_args *));
96 static int msdosfs_mkdir __P((struct vop_mkdir_args *));
97 static int msdosfs_rmdir __P((struct vop_rmdir_args *));
98 static int msdosfs_symlink __P((struct vop_symlink_args *));
99 static int msdosfs_readdir __P((struct vop_readdir_args *));
100 static int msdosfs_bmap __P((struct vop_bmap_args *));
101 static int msdosfs_strategy __P((struct vop_strategy_args *));
102 static int msdosfs_print __P((struct vop_print_args *));
103 static int msdosfs_pathconf __P((struct vop_pathconf_args *ap));
104 static int msdosfs_getpages __P((struct vop_getpages_args *));
105 static int msdosfs_putpages __P((struct vop_putpages_args *));
106 
107 /*
108  * Some general notes:
109  *
110  * In the ufs filesystem the inodes, superblocks, and indirect blocks are
111  * read/written using the vnode for the filesystem. Blocks that represent
112  * the contents of a file are read/written using the vnode for the file
113  * (including directories when they are read/written as files). This
114  * presents problems for the dos filesystem because data that should be in
115  * an inode (if dos had them) resides in the directory itself.  Since we
116  * must update directory entries without the benefit of having the vnode
117  * for the directory we must use the vnode for the filesystem.  This means
118  * that when a directory is actually read/written (via read, write, or
119  * readdir, or seek) we must use the vnode for the filesystem instead of
120  * the vnode for the directory as would happen in ufs. This is to insure we
121  * retreive the correct block from the buffer cache since the hash value is
122  * based upon the vnode address and the desired block number.
123  */
124 
125 /*
126  * Create a regular file. On entry the directory to contain the file being
127  * created is locked.  We must release before we return. We must also free
128  * the pathname buffer pointed at by cnp->cn_pnbuf, always on error, or
129  * only if the SAVESTART bit in cn_flags is clear on success.
130  */
131 static int
132 msdosfs_create(ap)
133 	struct vop_create_args /* {
134 		struct vnode *a_dvp;
135 		struct vnode **a_vpp;
136 		struct componentname *a_cnp;
137 		struct vattr *a_vap;
138 	} */ *ap;
139 {
140 	struct componentname *cnp = ap->a_cnp;
141 	struct denode ndirent;
142 	struct denode *dep;
143 	struct denode *pdep = VTODE(ap->a_dvp);
144 	struct timespec ts;
145 	int error;
146 
147 #ifdef MSDOSFS_DEBUG
148 	printf("msdosfs_create(cnp %p, vap %p\n", cnp, ap->a_vap);
149 #endif
150 
151 	/*
152 	 * If this is the root directory and there is no space left we
153 	 * can't do anything.  This is because the root directory can not
154 	 * change size.
155 	 */
156 	if (pdep->de_StartCluster == MSDOSFSROOT
157 	    && pdep->de_fndoffset >= pdep->de_FileSize) {
158 		error = ENOSPC;
159 		goto bad;
160 	}
161 
162 	/*
163 	 * Create a directory entry for the file, then call createde() to
164 	 * have it installed. NOTE: DOS files are always executable.  We
165 	 * use the absence of the owner write bit to make the file
166 	 * readonly.
167 	 */
168 #ifdef DIAGNOSTIC
169 	if ((cnp->cn_flags & HASBUF) == 0)
170 		panic("msdosfs_create: no name");
171 #endif
172 	bzero(&ndirent, sizeof(ndirent));
173 	error = uniqdosname(pdep, cnp, ndirent.de_Name);
174 	if (error)
175 		goto bad;
176 
177 	ndirent.de_Attributes = (ap->a_vap->va_mode & VWRITE) ?
178 				ATTR_ARCHIVE : ATTR_ARCHIVE | ATTR_READONLY;
179 	ndirent.de_LowerCase = 0;
180 	ndirent.de_StartCluster = 0;
181 	ndirent.de_FileSize = 0;
182 	ndirent.de_dev = pdep->de_dev;
183 	ndirent.de_devvp = pdep->de_devvp;
184 	ndirent.de_pmp = pdep->de_pmp;
185 	ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
186 	getnanotime(&ts);
187 	DETIMES(&ndirent, &ts, &ts, &ts);
188 	error = createde(&ndirent, pdep, &dep, cnp);
189 	if (error)
190 		goto bad;
191 	*ap->a_vpp = DETOV(dep);
192 	return (0);
193 
194 bad:
195 	return (error);
196 }
197 
198 static int
199 msdosfs_mknod(ap)
200 	struct vop_mknod_args /* {
201 		struct vnode *a_dvp;
202 		struct vnode **a_vpp;
203 		struct componentname *a_cnp;
204 		struct vattr *a_vap;
205 	} */ *ap;
206 {
207 
208 	switch (ap->a_vap->va_type) {
209 	case VDIR:
210 		return (msdosfs_mkdir((struct vop_mkdir_args *)ap));
211 		break;
212 
213 	case VREG:
214 		return (msdosfs_create((struct vop_create_args *)ap));
215 		break;
216 
217 	default:
218 		return (EINVAL);
219 	}
220 	/* NOTREACHED */
221 }
222 
223 static int
224 msdosfs_close(ap)
225 	struct vop_close_args /* {
226 		struct vnode *a_vp;
227 		int a_fflag;
228 		struct ucred *a_cred;
229 		struct proc *a_p;
230 	} */ *ap;
231 {
232 	struct vnode *vp = ap->a_vp;
233 	struct denode *dep = VTODE(vp);
234 	struct timespec ts;
235 
236 	mtx_enter(&vp->v_interlock, MTX_DEF);
237 	if (vp->v_usecount > 1) {
238 		getnanotime(&ts);
239 		DETIMES(dep, &ts, &ts, &ts);
240 	}
241 	mtx_exit(&vp->v_interlock, MTX_DEF);
242 	return 0;
243 }
244 
245 static int
246 msdosfs_access(ap)
247 	struct vop_access_args /* {
248 		struct vnode *a_vp;
249 		int a_mode;
250 		struct ucred *a_cred;
251 		struct proc *a_p;
252 	} */ *ap;
253 {
254 	struct vnode *vp = ap->a_vp;
255 	struct denode *dep = VTODE(ap->a_vp);
256 	struct msdosfsmount *pmp = dep->de_pmp;
257 	mode_t file_mode, mode = ap->a_mode;
258 
259 	file_mode = (S_IXUSR|S_IXGRP|S_IXOTH) | (S_IRUSR|S_IRGRP|S_IROTH) |
260 	    ((dep->de_Attributes & ATTR_READONLY) ? 0 : (S_IWUSR|S_IWGRP|S_IWOTH));
261 	file_mode &= pmp->pm_mask;
262 
263 	/*
264 	 * Disallow write attempts on read-only file systems;
265 	 * unless the file is a socket, fifo, or a block or
266 	 * character device resident on the file system.
267 	 */
268 	if (mode & VWRITE) {
269 		switch (vp->v_type) {
270 		case VDIR:
271 		case VLNK:
272 		case VREG:
273 			if (vp->v_mount->mnt_flag & MNT_RDONLY)
274 				return (EROFS);
275 			break;
276 		default:
277 			break;
278 		}
279 	}
280 
281 	return (vaccess(vp->v_type, file_mode, pmp->pm_uid, pmp->pm_gid,
282 	    ap->a_mode, ap->a_cred, NULL));
283 }
284 
285 static int
286 msdosfs_getattr(ap)
287 	struct vop_getattr_args /* {
288 		struct vnode *a_vp;
289 		struct vattr *a_vap;
290 		struct ucred *a_cred;
291 		struct proc *a_p;
292 	} */ *ap;
293 {
294 	struct denode *dep = VTODE(ap->a_vp);
295 	struct msdosfsmount *pmp = dep->de_pmp;
296 	struct vattr *vap = ap->a_vap;
297 	mode_t mode;
298 	struct timespec ts;
299 	u_long dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
300 	u_long fileid;
301 
302 	getnanotime(&ts);
303 	DETIMES(dep, &ts, &ts, &ts);
304 	vap->va_fsid = dev2udev(dep->de_dev);
305 	/*
306 	 * The following computation of the fileid must be the same as that
307 	 * used in msdosfs_readdir() to compute d_fileno. If not, pwd
308 	 * doesn't work.
309 	 */
310 	if (dep->de_Attributes & ATTR_DIRECTORY) {
311 		fileid = cntobn(pmp, dep->de_StartCluster) * dirsperblk;
312 		if (dep->de_StartCluster == MSDOSFSROOT)
313 			fileid = 1;
314 	} else {
315 		fileid = cntobn(pmp, dep->de_dirclust) * dirsperblk;
316 		if (dep->de_dirclust == MSDOSFSROOT)
317 			fileid = roottobn(pmp, 0) * dirsperblk;
318 		fileid += dep->de_diroffset / sizeof(struct direntry);
319 	}
320 	vap->va_fileid = fileid;
321 	if ((dep->de_Attributes & ATTR_READONLY) == 0)
322 		mode = S_IRWXU|S_IRWXG|S_IRWXO;
323 	else
324 		mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
325 	vap->va_mode = mode & pmp->pm_mask;
326 	vap->va_uid = pmp->pm_uid;
327 	vap->va_gid = pmp->pm_gid;
328 	vap->va_nlink = 1;
329 	vap->va_rdev = 0;
330 	vap->va_size = dep->de_FileSize;
331 	dos2unixtime(dep->de_MDate, dep->de_MTime, 0, &vap->va_mtime);
332 	if (pmp->pm_flags & MSDOSFSMNT_LONGNAME) {
333 		dos2unixtime(dep->de_ADate, 0, 0, &vap->va_atime);
334 		dos2unixtime(dep->de_CDate, dep->de_CTime, dep->de_CHun, &vap->va_ctime);
335 	} else {
336 		vap->va_atime = vap->va_mtime;
337 		vap->va_ctime = vap->va_mtime;
338 	}
339 	vap->va_flags = 0;
340 	if ((dep->de_Attributes & ATTR_ARCHIVE) == 0)
341 		vap->va_flags |= SF_ARCHIVED;
342 	vap->va_gen = 0;
343 	vap->va_blocksize = pmp->pm_bpcluster;
344 	vap->va_bytes =
345 	    (dep->de_FileSize + pmp->pm_crbomask) & ~pmp->pm_crbomask;
346 	vap->va_type = ap->a_vp->v_type;
347 	vap->va_filerev = dep->de_modrev;
348 	return (0);
349 }
350 
351 static int
352 msdosfs_setattr(ap)
353 	struct vop_setattr_args /* {
354 		struct vnode *a_vp;
355 		struct vattr *a_vap;
356 		struct ucred *a_cred;
357 		struct proc *a_p;
358 	} */ *ap;
359 {
360 	struct vnode *vp = ap->a_vp;
361 	struct denode *dep = VTODE(ap->a_vp);
362 	struct msdosfsmount *pmp = dep->de_pmp;
363 	struct vattr *vap = ap->a_vap;
364 	struct ucred *cred = ap->a_cred;
365 	int error = 0;
366 
367 #ifdef MSDOSFS_DEBUG
368 	printf("msdosfs_setattr(): vp %p, vap %p, cred %p, p %p\n",
369 	    ap->a_vp, vap, cred, ap->a_p);
370 #endif
371 
372 	/*
373 	 * Check for unsettable attributes.
374 	 */
375 	if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
376 	    (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
377 	    (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
378 	    (vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
379 #ifdef MSDOSFS_DEBUG
380 		printf("msdosfs_setattr(): returning EINVAL\n");
381 		printf("    va_type %d, va_nlink %x, va_fsid %lx, va_fileid %lx\n",
382 		    vap->va_type, vap->va_nlink, vap->va_fsid, vap->va_fileid);
383 		printf("    va_blocksize %lx, va_rdev %x, va_bytes %qx, va_gen %lx\n",
384 		    vap->va_blocksize, vap->va_rdev, vap->va_bytes, vap->va_gen);
385 		printf("    va_uid %x, va_gid %x\n",
386 		    vap->va_uid, vap->va_gid);
387 #endif
388 		return (EINVAL);
389 	}
390 	if (vap->va_flags != VNOVAL) {
391 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
392 			return (EROFS);
393 		if (cred->cr_uid != pmp->pm_uid &&
394 		    (error = suser_xxx(cred, ap->a_p, PRISON_ROOT)))
395 			return (error);
396 		/*
397 		 * We are very inconsistent about handling unsupported
398 		 * attributes.  We ignored the access time and the
399 		 * read and execute bits.  We were strict for the other
400 		 * attributes.
401 		 *
402 		 * Here we are strict, stricter than ufs in not allowing
403 		 * users to attempt to set SF_SETTABLE bits or anyone to
404 		 * set unsupported bits.  However, we ignore attempts to
405 		 * set ATTR_ARCHIVE for directories `cp -pr' from a more
406 		 * sensible file system attempts it a lot.
407 		 */
408 		if (cred->cr_uid != 0) {
409 			if (vap->va_flags & SF_SETTABLE)
410 				return EPERM;
411 		}
412 		if (vap->va_flags & ~SF_ARCHIVED)
413 			return EOPNOTSUPP;
414 		if (vap->va_flags & SF_ARCHIVED)
415 			dep->de_Attributes &= ~ATTR_ARCHIVE;
416 		else if (!(dep->de_Attributes & ATTR_DIRECTORY))
417 			dep->de_Attributes |= ATTR_ARCHIVE;
418 		dep->de_flag |= DE_MODIFIED;
419 	}
420 
421 	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
422 		uid_t uid;
423 		gid_t gid;
424 
425 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
426 			return (EROFS);
427 		uid = vap->va_uid;
428 		if (uid == (uid_t)VNOVAL)
429 			uid = pmp->pm_uid;
430 		gid = vap->va_gid;
431 		if (gid == (gid_t)VNOVAL)
432 			gid = pmp->pm_gid;
433 		if ((cred->cr_uid != pmp->pm_uid || uid != pmp->pm_uid ||
434 		    (gid != pmp->pm_gid && !groupmember(gid, cred))) &&
435 		    (error = suser_xxx(cred, ap->a_p, PRISON_ROOT)))
436 			return error;
437 		if (uid != pmp->pm_uid || gid != pmp->pm_gid)
438 			return EINVAL;
439 	}
440 
441 	if (vap->va_size != VNOVAL) {
442 		/*
443 		 * Disallow write attempts on read-only file systems;
444 		 * unless the file is a socket, fifo, or a block or
445 		 * character device resident on the file system.
446 		 */
447 		switch (vp->v_type) {
448 		case VDIR:
449 			return (EISDIR);
450 			/* NOT REACHED */
451 		case VLNK:
452 		case VREG:
453 			if (vp->v_mount->mnt_flag & MNT_RDONLY)
454 				return (EROFS);
455 			break;
456 		default:
457 			break;
458 		}
459 		error = detrunc(dep, vap->va_size, 0, cred, ap->a_p);
460 		if (error)
461 			return error;
462 	}
463 	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
464 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
465 			return (EROFS);
466 		if (cred->cr_uid != pmp->pm_uid &&
467 		    (error = suser_xxx(cred, ap->a_p, PRISON_ROOT)) &&
468 		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
469 		    (error = VOP_ACCESS(ap->a_vp, VWRITE, cred, ap->a_p))))
470 			return (error);
471 		if (vp->v_type != VDIR) {
472 			if ((pmp->pm_flags & MSDOSFSMNT_NOWIN95) == 0 &&
473 			    vap->va_atime.tv_sec != VNOVAL)
474 				unix2dostime(&vap->va_atime, &dep->de_ADate, NULL, NULL);
475 			if (vap->va_mtime.tv_sec != VNOVAL)
476 				unix2dostime(&vap->va_mtime, &dep->de_MDate, &dep->de_MTime, NULL);
477 			dep->de_Attributes |= ATTR_ARCHIVE;
478 			dep->de_flag |= DE_MODIFIED;
479 		}
480 	}
481 	/*
482 	 * DOS files only have the ability to have their writability
483 	 * attribute set, so we use the owner write bit to set the readonly
484 	 * attribute.
485 	 */
486 	if (vap->va_mode != (mode_t)VNOVAL) {
487 		if (vp->v_mount->mnt_flag & MNT_RDONLY)
488 			return (EROFS);
489 		if (cred->cr_uid != pmp->pm_uid &&
490 		    (error = suser_xxx(cred, ap->a_p, PRISON_ROOT)))
491 			return (error);
492 		if (vp->v_type != VDIR) {
493 			/* We ignore the read and execute bits. */
494 			if (vap->va_mode & VWRITE)
495 				dep->de_Attributes &= ~ATTR_READONLY;
496 			else
497 				dep->de_Attributes |= ATTR_READONLY;
498 			dep->de_flag |= DE_MODIFIED;
499 		}
500 	}
501 	return (deupdat(dep, 1));
502 }
503 
504 static int
505 msdosfs_read(ap)
506 	struct vop_read_args /* {
507 		struct vnode *a_vp;
508 		struct uio *a_uio;
509 		int a_ioflag;
510 		struct ucred *a_cred;
511 	} */ *ap;
512 {
513 	int error = 0;
514 	int blsize;
515 	int isadir;
516 	int orig_resid;
517 	u_int n;
518 	u_long diff;
519 	u_long on;
520 	daddr_t lbn;
521 	daddr_t rablock;
522 	int rasize;
523 	int seqcount;
524 	struct buf *bp;
525 	struct vnode *vp = ap->a_vp;
526 	struct denode *dep = VTODE(vp);
527 	struct msdosfsmount *pmp = dep->de_pmp;
528 	struct uio *uio = ap->a_uio;
529 
530 	if (uio->uio_offset < 0)
531 		return (EINVAL);
532 
533 	if ((uoff_t)uio->uio_offset > DOS_FILESIZE_MAX)
534                 return (0);
535 	/*
536 	 * If they didn't ask for any data, then we are done.
537 	 */
538 	orig_resid = uio->uio_resid;
539 	if (orig_resid <= 0)
540 		return (0);
541 
542 	seqcount = ap->a_ioflag >> 16;
543 
544 	isadir = dep->de_Attributes & ATTR_DIRECTORY;
545 	do {
546 		if (uio->uio_offset >= dep->de_FileSize)
547 			break;
548 		lbn = de_cluster(pmp, uio->uio_offset);
549 		/*
550 		 * If we are operating on a directory file then be sure to
551 		 * do i/o with the vnode for the filesystem instead of the
552 		 * vnode for the directory.
553 		 */
554 		if (isadir) {
555 			/* convert cluster # to block # */
556 			error = pcbmap(dep, lbn, &lbn, 0, &blsize);
557 			if (error == E2BIG) {
558 				error = EINVAL;
559 				break;
560 			} else if (error)
561 				break;
562 			error = bread(pmp->pm_devvp, lbn, blsize, NOCRED, &bp);
563 		} else {
564 			blsize = pmp->pm_bpcluster;
565 			rablock = lbn + 1;
566 			if (seqcount > 1 &&
567 			    de_cn2off(pmp, rablock) < dep->de_FileSize) {
568 				rasize = pmp->pm_bpcluster;
569 				error = breadn(vp, lbn, blsize,
570 				    &rablock, &rasize, 1, NOCRED, &bp);
571 			} else {
572 				error = bread(vp, lbn, blsize, NOCRED, &bp);
573 			}
574 		}
575 		if (error) {
576 			brelse(bp);
577 			break;
578 		}
579 		on = uio->uio_offset & pmp->pm_crbomask;
580 		diff = pmp->pm_bpcluster - on;
581 		n = diff > uio->uio_resid ? uio->uio_resid : diff;
582 		diff = dep->de_FileSize - uio->uio_offset;
583 		if (diff < n)
584 			n = diff;
585 		diff = blsize - bp->b_resid;
586 		if (diff < n)
587 			n = diff;
588 		error = uiomove(bp->b_data + on, (int) n, uio);
589 		brelse(bp);
590 	} while (error == 0 && uio->uio_resid > 0 && n != 0);
591 	if (!isadir && (error == 0 || uio->uio_resid != orig_resid) &&
592 	    (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
593 		dep->de_flag |= DE_ACCESS;
594 	return (error);
595 }
596 
597 /*
598  * Write data to a file or directory.
599  */
600 static int
601 msdosfs_write(ap)
602 	struct vop_write_args /* {
603 		struct vnode *a_vp;
604 		struct uio *a_uio;
605 		int a_ioflag;
606 		struct ucred *a_cred;
607 	} */ *ap;
608 {
609 	int n;
610 	int croffset;
611 	int resid;
612 	u_long osize;
613 	int error = 0;
614 	u_long count;
615 	daddr_t bn, lastcn;
616 	struct buf *bp;
617 	int ioflag = ap->a_ioflag;
618 	struct uio *uio = ap->a_uio;
619 	struct proc *p = uio->uio_procp;
620 	struct vnode *vp = ap->a_vp;
621 	struct vnode *thisvp;
622 	struct denode *dep = VTODE(vp);
623 	struct msdosfsmount *pmp = dep->de_pmp;
624 	struct ucred *cred = ap->a_cred;
625 
626 #ifdef MSDOSFS_DEBUG
627 	printf("msdosfs_write(vp %p, uio %p, ioflag %x, cred %p\n",
628 	    vp, uio, ioflag, cred);
629 	printf("msdosfs_write(): diroff %lu, dirclust %lu, startcluster %lu\n",
630 	    dep->de_diroffset, dep->de_dirclust, dep->de_StartCluster);
631 #endif
632 
633 	switch (vp->v_type) {
634 	case VREG:
635 		if (ioflag & IO_APPEND)
636 			uio->uio_offset = dep->de_FileSize;
637 		thisvp = vp;
638 		break;
639 	case VDIR:
640 		return EISDIR;
641 	default:
642 		panic("msdosfs_write(): bad file type");
643 	}
644 
645 	if (uio->uio_offset < 0)
646 		return (EFBIG);
647 
648 	if (uio->uio_resid == 0)
649 		return (0);
650 
651 	/*
652 	 * If they've exceeded their filesize limit, tell them about it.
653 	 */
654 	if (p &&
655 	    ((uoff_t)uio->uio_offset + uio->uio_resid >
656 	    p->p_rlimit[RLIMIT_FSIZE].rlim_cur)) {
657 		psignal(p, SIGXFSZ);
658 		return (EFBIG);
659 	}
660 
661 	if ((uoff_t)uio->uio_offset + uio->uio_resid > DOS_FILESIZE_MAX)
662                 return (EFBIG);
663 
664 	/*
665 	 * If the offset we are starting the write at is beyond the end of
666 	 * the file, then they've done a seek.  Unix filesystems allow
667 	 * files with holes in them, DOS doesn't so we must fill the hole
668 	 * with zeroed blocks.
669 	 */
670 	if (uio->uio_offset > dep->de_FileSize) {
671 		error = deextend(dep, uio->uio_offset, cred);
672 		if (error)
673 			return (error);
674 	}
675 
676 	/*
677 	 * Remember some values in case the write fails.
678 	 */
679 	resid = uio->uio_resid;
680 	osize = dep->de_FileSize;
681 
682 	/*
683 	 * If we write beyond the end of the file, extend it to its ultimate
684 	 * size ahead of the time to hopefully get a contiguous area.
685 	 */
686 	if (uio->uio_offset + resid > osize) {
687 		count = de_clcount(pmp, uio->uio_offset + resid) -
688 			de_clcount(pmp, osize);
689 		error = extendfile(dep, count, NULL, NULL, 0);
690 		if (error &&  (error != ENOSPC || (ioflag & IO_UNIT)))
691 			goto errexit;
692 		lastcn = dep->de_fc[FC_LASTFC].fc_frcn;
693 	} else
694 		lastcn = de_clcount(pmp, osize) - 1;
695 
696 	do {
697 		if (de_cluster(pmp, uio->uio_offset) > lastcn) {
698 			error = ENOSPC;
699 			break;
700 		}
701 
702 		croffset = uio->uio_offset & pmp->pm_crbomask;
703 		n = min(uio->uio_resid, pmp->pm_bpcluster - croffset);
704 		if (uio->uio_offset + n > dep->de_FileSize) {
705 			dep->de_FileSize = uio->uio_offset + n;
706 			/* The object size needs to be set before buffer is allocated */
707 			vnode_pager_setsize(vp, dep->de_FileSize);
708 		}
709 
710 		bn = de_cluster(pmp, uio->uio_offset);
711 		if ((uio->uio_offset & pmp->pm_crbomask) == 0
712 		    && (de_cluster(pmp, uio->uio_offset + uio->uio_resid)
713 		        > de_cluster(pmp, uio->uio_offset)
714 			|| uio->uio_offset + uio->uio_resid >= dep->de_FileSize)) {
715 			/*
716 			 * If either the whole cluster gets written,
717 			 * or we write the cluster from its start beyond EOF,
718 			 * then no need to read data from disk.
719 			 */
720 			bp = getblk(thisvp, bn, pmp->pm_bpcluster, 0, 0);
721 			clrbuf(bp);
722 			/*
723 			 * Do the bmap now, since pcbmap needs buffers
724 			 * for the fat table. (see msdosfs_strategy)
725 			 */
726 			if (bp->b_blkno == bp->b_lblkno) {
727 				error = pcbmap(dep, bp->b_lblkno, &bp->b_blkno,
728 				     0, 0);
729 				if (error)
730 					bp->b_blkno = -1;
731 			}
732 			if (bp->b_blkno == -1) {
733 				brelse(bp);
734 				if (!error)
735 					error = EIO;		/* XXX */
736 				break;
737 			}
738 		} else {
739 			/*
740 			 * The block we need to write into exists, so read it in.
741 			 */
742 			error = bread(thisvp, bn, pmp->pm_bpcluster, cred, &bp);
743 			if (error) {
744 				brelse(bp);
745 				break;
746 			}
747 		}
748 
749 		/*
750 		 * Should these vnode_pager_* functions be done on dir
751 		 * files?
752 		 */
753 
754 		/*
755 		 * Copy the data from user space into the buf header.
756 		 */
757 		error = uiomove(bp->b_data + croffset, n, uio);
758 		if (error) {
759 			brelse(bp);
760 			break;
761 		}
762 
763 		/*
764 		 * If they want this synchronous then write it and wait for
765 		 * it.  Otherwise, if on a cluster boundary write it
766 		 * asynchronously so we can move on to the next block
767 		 * without delay.  Otherwise do a delayed write because we
768 		 * may want to write somemore into the block later.
769 		 */
770 		if (ioflag & IO_SYNC)
771 			(void) bwrite(bp);
772 		else if (n + croffset == pmp->pm_bpcluster)
773 			bawrite(bp);
774 		else
775 			bdwrite(bp);
776 		dep->de_flag |= DE_UPDATE;
777 	} while (error == 0 && uio->uio_resid > 0);
778 
779 	/*
780 	 * If the write failed and they want us to, truncate the file back
781 	 * to the size it was before the write was attempted.
782 	 */
783 errexit:
784 	if (error) {
785 		if (ioflag & IO_UNIT) {
786 			detrunc(dep, osize, ioflag & IO_SYNC, NOCRED, NULL);
787 			uio->uio_offset -= resid - uio->uio_resid;
788 			uio->uio_resid = resid;
789 		} else {
790 			detrunc(dep, dep->de_FileSize, ioflag & IO_SYNC, NOCRED, NULL);
791 			if (uio->uio_resid != resid)
792 				error = 0;
793 		}
794 	} else if (ioflag & IO_SYNC)
795 		error = deupdat(dep, 1);
796 	return (error);
797 }
798 
799 /*
800  * Flush the blocks of a file to disk.
801  *
802  * This function is worthless for vnodes that represent directories. Maybe we
803  * could just do a sync if they try an fsync on a directory file.
804  */
805 static int
806 msdosfs_fsync(ap)
807 	struct vop_fsync_args /* {
808 		struct vnode *a_vp;
809 		struct ucred *a_cred;
810 		int a_waitfor;
811 		struct proc *a_p;
812 	} */ *ap;
813 {
814 	struct vnode *vp = ap->a_vp;
815 	int s;
816 	struct buf *bp, *nbp;
817 
818 	/*
819 	 * Flush all dirty buffers associated with a vnode.
820 	 */
821 loop:
822 	s = splbio();
823 	for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
824 		nbp = TAILQ_NEXT(bp, b_vnbufs);
825 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
826 			continue;
827 		if ((bp->b_flags & B_DELWRI) == 0)
828 			panic("msdosfs_fsync: not dirty");
829 		bremfree(bp);
830 		splx(s);
831 		(void) bwrite(bp);
832 		goto loop;
833 	}
834 	while (vp->v_numoutput) {
835 		vp->v_flag |= VBWAIT;
836 		(void) tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "msdosfsn", 0);
837 	}
838 #ifdef DIAGNOSTIC
839 	if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
840 		vprint("msdosfs_fsync: dirty", vp);
841 		goto loop;
842 	}
843 #endif
844 	splx(s);
845 	return (deupdat(VTODE(vp), ap->a_waitfor == MNT_WAIT));
846 }
847 
848 static int
849 msdosfs_remove(ap)
850 	struct vop_remove_args /* {
851 		struct vnode *a_dvp;
852 		struct vnode *a_vp;
853 		struct componentname *a_cnp;
854 	} */ *ap;
855 {
856 	struct denode *dep = VTODE(ap->a_vp);
857 	struct denode *ddep = VTODE(ap->a_dvp);
858 	int error;
859 
860 	if (ap->a_vp->v_type == VDIR)
861 		error = EPERM;
862 	else
863 		error = removede(ddep, dep);
864 #ifdef MSDOSFS_DEBUG
865 	printf("msdosfs_remove(), dep %p, v_usecount %d\n", dep, ap->a_vp->v_usecount);
866 #endif
867 	return (error);
868 }
869 
870 /*
871  * DOS filesystems don't know what links are.
872  */
873 static int
874 msdosfs_link(ap)
875 	struct vop_link_args /* {
876 		struct vnode *a_tdvp;
877 		struct vnode *a_vp;
878 		struct componentname *a_cnp;
879 	} */ *ap;
880 {
881 	return (EOPNOTSUPP);
882 }
883 
884 /*
885  * Renames on files require moving the denode to a new hash queue since the
886  * denode's location is used to compute which hash queue to put the file
887  * in. Unless it is a rename in place.  For example "mv a b".
888  *
889  * What follows is the basic algorithm:
890  *
891  * if (file move) {
892  *	if (dest file exists) {
893  *		remove dest file
894  *	}
895  *	if (dest and src in same directory) {
896  *		rewrite name in existing directory slot
897  *	} else {
898  *		write new entry in dest directory
899  *		update offset and dirclust in denode
900  *		move denode to new hash chain
901  *		clear old directory entry
902  *	}
903  * } else {
904  *	directory move
905  *	if (dest directory exists) {
906  *		if (dest is not empty) {
907  *			return ENOTEMPTY
908  *		}
909  *		remove dest directory
910  *	}
911  *	if (dest and src in same directory) {
912  *		rewrite name in existing entry
913  *	} else {
914  *		be sure dest is not a child of src directory
915  *		write entry in dest directory
916  *		update "." and ".." in moved directory
917  *		clear old directory entry for moved directory
918  *	}
919  * }
920  *
921  * On entry:
922  *	source's parent directory is unlocked
923  *	source file or directory is unlocked
924  *	destination's parent directory is locked
925  *	destination file or directory is locked if it exists
926  *
927  * On exit:
928  *	all denodes should be released
929  */
930 static int
931 msdosfs_rename(ap)
932 	struct vop_rename_args /* {
933 		struct vnode *a_fdvp;
934 		struct vnode *a_fvp;
935 		struct componentname *a_fcnp;
936 		struct vnode *a_tdvp;
937 		struct vnode *a_tvp;
938 		struct componentname *a_tcnp;
939 	} */ *ap;
940 {
941 	struct vnode *tdvp = ap->a_tdvp;
942 	struct vnode *fvp = ap->a_fvp;
943 	struct vnode *fdvp = ap->a_fdvp;
944 	struct vnode *tvp = ap->a_tvp;
945 	struct componentname *tcnp = ap->a_tcnp;
946 	struct componentname *fcnp = ap->a_fcnp;
947 	struct proc *p = fcnp->cn_proc;
948 	struct denode *ip, *xp, *dp, *zp;
949 	u_char toname[11], oldname[11];
950 	u_long from_diroffset, to_diroffset;
951 	u_char to_count;
952 	int doingdirectory = 0, newparent = 0;
953 	int error;
954 	u_long cn;
955 	daddr_t bn;
956 	struct denode *fddep;	/* from file's parent directory	 */
957 	struct denode *fdep;	/* from file or directory	 */
958 	struct denode *tddep;	/* to file's parent directory	 */
959 	struct denode *tdep;	/* to file or directory		 */
960 	struct msdosfsmount *pmp;
961 	struct direntry *dotdotp;
962 	struct buf *bp;
963 
964 	fddep = VTODE(ap->a_fdvp);
965 	fdep = VTODE(ap->a_fvp);
966 	tddep = VTODE(ap->a_tdvp);
967 	tdep = tvp ? VTODE(tvp) : NULL;
968 	pmp = fddep->de_pmp;
969 
970 	pmp = VFSTOMSDOSFS(fdvp->v_mount);
971 
972 #ifdef DIAGNOSTIC
973 	if ((tcnp->cn_flags & HASBUF) == 0 ||
974 	    (fcnp->cn_flags & HASBUF) == 0)
975 		panic("msdosfs_rename: no name");
976 #endif
977 	/*
978 	 * Check for cross-device rename.
979 	 */
980 	if ((fvp->v_mount != tdvp->v_mount) ||
981 	    (tvp && (fvp->v_mount != tvp->v_mount))) {
982 		error = EXDEV;
983 abortit:
984 		if (tdvp == tvp)
985 			vrele(tdvp);
986 		else
987 			vput(tdvp);
988 		if (tvp)
989 			vput(tvp);
990 		vrele(fdvp);
991 		vrele(fvp);
992 		return (error);
993 	}
994 
995 	/*
996 	 * If source and dest are the same, do nothing.
997 	 */
998 	if (tvp == fvp) {
999 		error = 0;
1000 		goto abortit;
1001 	}
1002 
1003 	error = vn_lock(fvp, LK_EXCLUSIVE, p);
1004 	if (error)
1005 		goto abortit;
1006 	dp = VTODE(fdvp);
1007 	ip = VTODE(fvp);
1008 
1009 	/*
1010 	 * Be sure we are not renaming ".", "..", or an alias of ".". This
1011 	 * leads to a crippled directory tree.  It's pretty tough to do a
1012 	 * "ls" or "pwd" with the "." directory entry missing, and "cd .."
1013 	 * doesn't work if the ".." entry is missing.
1014 	 */
1015 	if (ip->de_Attributes & ATTR_DIRECTORY) {
1016 		/*
1017 		 * Avoid ".", "..", and aliases of "." for obvious reasons.
1018 		 */
1019 		if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
1020 		    dp == ip ||
1021 		    (fcnp->cn_flags & ISDOTDOT) ||
1022 		    (tcnp->cn_flags & ISDOTDOT) ||
1023 		    (ip->de_flag & DE_RENAME)) {
1024 			VOP_UNLOCK(fvp, 0, p);
1025 			error = EINVAL;
1026 			goto abortit;
1027 		}
1028 		ip->de_flag |= DE_RENAME;
1029 		doingdirectory++;
1030 	}
1031 
1032 	/*
1033 	 * When the target exists, both the directory
1034 	 * and target vnodes are returned locked.
1035 	 */
1036 	dp = VTODE(tdvp);
1037 	xp = tvp ? VTODE(tvp) : NULL;
1038 	/*
1039 	 * Remember direntry place to use for destination
1040 	 */
1041 	to_diroffset = dp->de_fndoffset;
1042 	to_count = dp->de_fndcnt;
1043 
1044 	/*
1045 	 * If ".." must be changed (ie the directory gets a new
1046 	 * parent) then the source directory must not be in the
1047 	 * directory heirarchy above the target, as this would
1048 	 * orphan everything below the source directory. Also
1049 	 * the user must have write permission in the source so
1050 	 * as to be able to change "..". We must repeat the call
1051 	 * to namei, as the parent directory is unlocked by the
1052 	 * call to doscheckpath().
1053 	 */
1054 	error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
1055 	VOP_UNLOCK(fvp, 0, p);
1056 	if (VTODE(fdvp)->de_StartCluster != VTODE(tdvp)->de_StartCluster)
1057 		newparent = 1;
1058 	if (doingdirectory && newparent) {
1059 		if (error)	/* write access check above */
1060 			goto bad;
1061 		if (xp != NULL)
1062 			vput(tvp);
1063 		/*
1064 		 * doscheckpath() vput()'s dp,
1065 		 * so we have to do a relookup afterwards
1066 		 */
1067 		error = doscheckpath(ip, dp);
1068 		if (error)
1069 			goto out;
1070 		if ((tcnp->cn_flags & SAVESTART) == 0)
1071 			panic("msdosfs_rename: lost to startdir");
1072 		error = relookup(tdvp, &tvp, tcnp);
1073 		if (error)
1074 			goto out;
1075 		dp = VTODE(tdvp);
1076 		xp = tvp ? VTODE(tvp) : NULL;
1077 	}
1078 
1079 	if (xp != NULL) {
1080 		/*
1081 		 * Target must be empty if a directory and have no links
1082 		 * to it. Also, ensure source and target are compatible
1083 		 * (both directories, or both not directories).
1084 		 */
1085 		if (xp->de_Attributes & ATTR_DIRECTORY) {
1086 			if (!dosdirempty(xp)) {
1087 				error = ENOTEMPTY;
1088 				goto bad;
1089 			}
1090 			if (!doingdirectory) {
1091 				error = ENOTDIR;
1092 				goto bad;
1093 			}
1094 			cache_purge(tdvp);
1095 		} else if (doingdirectory) {
1096 			error = EISDIR;
1097 			goto bad;
1098 		}
1099 		error = removede(dp, xp);
1100 		if (error)
1101 			goto bad;
1102 		vput(tvp);
1103 		xp = NULL;
1104 	}
1105 
1106 	/*
1107 	 * Convert the filename in tcnp into a dos filename. We copy this
1108 	 * into the denode and directory entry for the destination
1109 	 * file/directory.
1110 	 */
1111 	error = uniqdosname(VTODE(tdvp), tcnp, toname);
1112 	if (error)
1113 		goto abortit;
1114 
1115 	/*
1116 	 * Since from wasn't locked at various places above,
1117 	 * have to do a relookup here.
1118 	 */
1119 	fcnp->cn_flags &= ~MODMASK;
1120 	fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
1121 	if ((fcnp->cn_flags & SAVESTART) == 0)
1122 		panic("msdosfs_rename: lost from startdir");
1123 	if (!newparent)
1124 		VOP_UNLOCK(tdvp, 0, p);
1125 	if (relookup(fdvp, &fvp, fcnp) == 0)
1126 		vrele(fdvp);
1127 	if (fvp == NULL) {
1128 		/*
1129 		 * From name has disappeared.
1130 		 */
1131 		if (doingdirectory)
1132 			panic("rename: lost dir entry");
1133 		vrele(ap->a_fvp);
1134 		if (newparent)
1135 			VOP_UNLOCK(tdvp, 0, p);
1136 		vrele(tdvp);
1137 		return 0;
1138 	}
1139 	xp = VTODE(fvp);
1140 	zp = VTODE(fdvp);
1141 	from_diroffset = zp->de_fndoffset;
1142 
1143 	/*
1144 	 * Ensure that the directory entry still exists and has not
1145 	 * changed till now. If the source is a file the entry may
1146 	 * have been unlinked or renamed. In either case there is
1147 	 * no further work to be done. If the source is a directory
1148 	 * then it cannot have been rmdir'ed or renamed; this is
1149 	 * prohibited by the DE_RENAME flag.
1150 	 */
1151 	if (xp != ip) {
1152 		if (doingdirectory)
1153 			panic("rename: lost dir entry");
1154 		vrele(ap->a_fvp);
1155 		VOP_UNLOCK(fvp, 0, p);
1156 		if (newparent)
1157 			VOP_UNLOCK(fdvp, 0, p);
1158 		xp = NULL;
1159 	} else {
1160 		vrele(fvp);
1161 		xp = NULL;
1162 
1163 		/*
1164 		 * First write a new entry in the destination
1165 		 * directory and mark the entry in the source directory
1166 		 * as deleted.  Then move the denode to the correct hash
1167 		 * chain for its new location in the filesystem.  And, if
1168 		 * we moved a directory, then update its .. entry to point
1169 		 * to the new parent directory.
1170 		 */
1171 		bcopy(ip->de_Name, oldname, 11);
1172 		bcopy(toname, ip->de_Name, 11);	/* update denode */
1173 		dp->de_fndoffset = to_diroffset;
1174 		dp->de_fndcnt = to_count;
1175 		error = createde(ip, dp, (struct denode **)0, tcnp);
1176 		if (error) {
1177 			bcopy(oldname, ip->de_Name, 11);
1178 			if (newparent)
1179 				VOP_UNLOCK(fdvp, 0, p);
1180 			VOP_UNLOCK(fvp, 0, p);
1181 			goto bad;
1182 		}
1183 		ip->de_refcnt++;
1184 		zp->de_fndoffset = from_diroffset;
1185 		error = removede(zp, ip);
1186 		if (error) {
1187 			/* XXX should really panic here, fs is corrupt */
1188 			if (newparent)
1189 				VOP_UNLOCK(fdvp, 0, p);
1190 			VOP_UNLOCK(fvp, 0, p);
1191 			goto bad;
1192 		}
1193 		if (!doingdirectory) {
1194 			error = pcbmap(dp, de_cluster(pmp, to_diroffset), 0,
1195 				       &ip->de_dirclust, 0);
1196 			if (error) {
1197 				/* XXX should really panic here, fs is corrupt */
1198 				if (newparent)
1199 					VOP_UNLOCK(fdvp, 0, p);
1200 				VOP_UNLOCK(fvp, 0, p);
1201 				goto bad;
1202 			}
1203 			if (ip->de_dirclust == MSDOSFSROOT)
1204 				ip->de_diroffset = to_diroffset;
1205 			else
1206 				ip->de_diroffset = to_diroffset & pmp->pm_crbomask;
1207 		}
1208 		reinsert(ip);
1209 		if (newparent)
1210 			VOP_UNLOCK(fdvp, 0, p);
1211 	}
1212 
1213 	/*
1214 	 * If we moved a directory to a new parent directory, then we must
1215 	 * fixup the ".." entry in the moved directory.
1216 	 */
1217 	if (doingdirectory && newparent) {
1218 		cn = ip->de_StartCluster;
1219 		if (cn == MSDOSFSROOT) {
1220 			/* this should never happen */
1221 			panic("msdosfs_rename(): updating .. in root directory?");
1222 		} else
1223 			bn = cntobn(pmp, cn);
1224 		error = bread(pmp->pm_devvp, bn, pmp->pm_bpcluster,
1225 			      NOCRED, &bp);
1226 		if (error) {
1227 			/* XXX should really panic here, fs is corrupt */
1228 			brelse(bp);
1229 			VOP_UNLOCK(fvp, 0, p);
1230 			goto bad;
1231 		}
1232 		dotdotp = (struct direntry *)bp->b_data + 1;
1233 		putushort(dotdotp->deStartCluster, dp->de_StartCluster);
1234 		if (FAT32(pmp))
1235 			putushort(dotdotp->deHighClust, dp->de_StartCluster >> 16);
1236 		error = bwrite(bp);
1237 		if (error) {
1238 			/* XXX should really panic here, fs is corrupt */
1239 			VOP_UNLOCK(fvp, 0, p);
1240 			goto bad;
1241 		}
1242 	}
1243 
1244 	VOP_UNLOCK(fvp, 0, p);
1245 bad:
1246 	if (xp)
1247 		vput(tvp);
1248 	vput(tdvp);
1249 out:
1250 	ip->de_flag &= ~DE_RENAME;
1251 	vrele(fdvp);
1252 	vrele(fvp);
1253 	return (error);
1254 
1255 }
1256 
1257 static struct {
1258 	struct direntry dot;
1259 	struct direntry dotdot;
1260 } dosdirtemplate = {
1261 	{	".       ", "   ",			/* the . entry */
1262 		ATTR_DIRECTORY,				/* file attribute */
1263 		0,	 				/* reserved */
1264 		0, { 0, 0 }, { 0, 0 },			/* create time & date */
1265 		{ 0, 0 },				/* access date */
1266 		{ 0, 0 },				/* high bits of start cluster */
1267 		{ 210, 4 }, { 210, 4 },			/* modify time & date */
1268 		{ 0, 0 },				/* startcluster */
1269 		{ 0, 0, 0, 0 } 				/* filesize */
1270 	},
1271 	{	"..      ", "   ",			/* the .. entry */
1272 		ATTR_DIRECTORY,				/* file attribute */
1273 		0,	 				/* reserved */
1274 		0, { 0, 0 }, { 0, 0 },			/* create time & date */
1275 		{ 0, 0 },				/* access date */
1276 		{ 0, 0 },				/* high bits of start cluster */
1277 		{ 210, 4 }, { 210, 4 },			/* modify time & date */
1278 		{ 0, 0 },				/* startcluster */
1279 		{ 0, 0, 0, 0 }				/* filesize */
1280 	}
1281 };
1282 
1283 static int
1284 msdosfs_mkdir(ap)
1285 	struct vop_mkdir_args /* {
1286 		struct vnode *a_dvp;
1287 		struvt vnode **a_vpp;
1288 		struvt componentname *a_cnp;
1289 		struct vattr *a_vap;
1290 	} */ *ap;
1291 {
1292 	struct componentname *cnp = ap->a_cnp;
1293 	struct denode *dep;
1294 	struct denode *pdep = VTODE(ap->a_dvp);
1295 	struct direntry *denp;
1296 	struct msdosfsmount *pmp = pdep->de_pmp;
1297 	struct buf *bp;
1298 	u_long newcluster, pcl;
1299 	int bn;
1300 	int error;
1301 	struct denode ndirent;
1302 	struct timespec ts;
1303 
1304 	/*
1305 	 * If this is the root directory and there is no space left we
1306 	 * can't do anything.  This is because the root directory can not
1307 	 * change size.
1308 	 */
1309 	if (pdep->de_StartCluster == MSDOSFSROOT
1310 	    && pdep->de_fndoffset >= pdep->de_FileSize) {
1311 		error = ENOSPC;
1312 		goto bad2;
1313 	}
1314 
1315 	/*
1316 	 * Allocate a cluster to hold the about to be created directory.
1317 	 */
1318 	error = clusteralloc(pmp, 0, 1, CLUST_EOFE, &newcluster, NULL);
1319 	if (error)
1320 		goto bad2;
1321 
1322 	bzero(&ndirent, sizeof(ndirent));
1323 	ndirent.de_pmp = pmp;
1324 	ndirent.de_flag = DE_ACCESS | DE_CREATE | DE_UPDATE;
1325 	getnanotime(&ts);
1326 	DETIMES(&ndirent, &ts, &ts, &ts);
1327 
1328 	/*
1329 	 * Now fill the cluster with the "." and ".." entries. And write
1330 	 * the cluster to disk.  This way it is there for the parent
1331 	 * directory to be pointing at if there were a crash.
1332 	 */
1333 	bn = cntobn(pmp, newcluster);
1334 	/* always succeeds */
1335 	bp = getblk(pmp->pm_devvp, bn, pmp->pm_bpcluster, 0, 0);
1336 	bzero(bp->b_data, pmp->pm_bpcluster);
1337 	bcopy(&dosdirtemplate, bp->b_data, sizeof dosdirtemplate);
1338 	denp = (struct direntry *)bp->b_data;
1339 	putushort(denp[0].deStartCluster, newcluster);
1340 	putushort(denp[0].deCDate, ndirent.de_CDate);
1341 	putushort(denp[0].deCTime, ndirent.de_CTime);
1342 	denp[0].deCHundredth = ndirent.de_CHun;
1343 	putushort(denp[0].deADate, ndirent.de_ADate);
1344 	putushort(denp[0].deMDate, ndirent.de_MDate);
1345 	putushort(denp[0].deMTime, ndirent.de_MTime);
1346 	pcl = pdep->de_StartCluster;
1347 	if (FAT32(pmp) && pcl == pmp->pm_rootdirblk)
1348 		pcl = 0;
1349 	putushort(denp[1].deStartCluster, pcl);
1350 	putushort(denp[1].deCDate, ndirent.de_CDate);
1351 	putushort(denp[1].deCTime, ndirent.de_CTime);
1352 	denp[1].deCHundredth = ndirent.de_CHun;
1353 	putushort(denp[1].deADate, ndirent.de_ADate);
1354 	putushort(denp[1].deMDate, ndirent.de_MDate);
1355 	putushort(denp[1].deMTime, ndirent.de_MTime);
1356 	if (FAT32(pmp)) {
1357 		putushort(denp[0].deHighClust, newcluster >> 16);
1358 		putushort(denp[1].deHighClust, pdep->de_StartCluster >> 16);
1359 	}
1360 
1361 	error = bwrite(bp);
1362 	if (error)
1363 		goto bad;
1364 
1365 	/*
1366 	 * Now build up a directory entry pointing to the newly allocated
1367 	 * cluster.  This will be written to an empty slot in the parent
1368 	 * directory.
1369 	 */
1370 #ifdef DIAGNOSTIC
1371 	if ((cnp->cn_flags & HASBUF) == 0)
1372 		panic("msdosfs_mkdir: no name");
1373 #endif
1374 	error = uniqdosname(pdep, cnp, ndirent.de_Name);
1375 	if (error)
1376 		goto bad;
1377 
1378 	ndirent.de_Attributes = ATTR_DIRECTORY;
1379 	ndirent.de_LowerCase = 0;
1380 	ndirent.de_StartCluster = newcluster;
1381 	ndirent.de_FileSize = 0;
1382 	ndirent.de_dev = pdep->de_dev;
1383 	ndirent.de_devvp = pdep->de_devvp;
1384 	error = createde(&ndirent, pdep, &dep, cnp);
1385 	if (error)
1386 		goto bad;
1387 	*ap->a_vpp = DETOV(dep);
1388 	return (0);
1389 
1390 bad:
1391 	clusterfree(pmp, newcluster, NULL);
1392 bad2:
1393 	return (error);
1394 }
1395 
1396 static int
1397 msdosfs_rmdir(ap)
1398 	struct vop_rmdir_args /* {
1399 		struct vnode *a_dvp;
1400 		struct vnode *a_vp;
1401 		struct componentname *a_cnp;
1402 	} */ *ap;
1403 {
1404 	register struct vnode *vp = ap->a_vp;
1405 	register struct vnode *dvp = ap->a_dvp;
1406 	register struct componentname *cnp = ap->a_cnp;
1407 	register struct denode *ip, *dp;
1408 	struct proc *p = cnp->cn_proc;
1409 	int error;
1410 
1411 	ip = VTODE(vp);
1412 	dp = VTODE(dvp);
1413 
1414 	/*
1415 	 * Verify the directory is empty (and valid).
1416 	 * (Rmdir ".." won't be valid since
1417 	 *  ".." will contain a reference to
1418 	 *  the current directory and thus be
1419 	 *  non-empty.)
1420 	 */
1421 	error = 0;
1422 	if (!dosdirempty(ip) || ip->de_flag & DE_RENAME) {
1423 		error = ENOTEMPTY;
1424 		goto out;
1425 	}
1426 	/*
1427 	 * Delete the entry from the directory.  For dos filesystems this
1428 	 * gets rid of the directory entry on disk, the in memory copy
1429 	 * still exists but the de_refcnt is <= 0.  This prevents it from
1430 	 * being found by deget().  When the vput() on dep is done we give
1431 	 * up access and eventually msdosfs_reclaim() will be called which
1432 	 * will remove it from the denode cache.
1433 	 */
1434 	error = removede(dp, ip);
1435 	if (error)
1436 		goto out;
1437 	/*
1438 	 * This is where we decrement the link count in the parent
1439 	 * directory.  Since dos filesystems don't do this we just purge
1440 	 * the name cache.
1441 	 */
1442 	cache_purge(dvp);
1443 	VOP_UNLOCK(dvp, 0, p);
1444 	/*
1445 	 * Truncate the directory that is being deleted.
1446 	 */
1447 	error = detrunc(ip, (u_long)0, IO_SYNC, cnp->cn_cred, p);
1448 	cache_purge(vp);
1449 
1450 	vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
1451 out:
1452 	return (error);
1453 }
1454 
1455 /*
1456  * DOS filesystems don't know what symlinks are.
1457  */
1458 static int
1459 msdosfs_symlink(ap)
1460 	struct vop_symlink_args /* {
1461 		struct vnode *a_dvp;
1462 		struct vnode **a_vpp;
1463 		struct componentname *a_cnp;
1464 		struct vattr *a_vap;
1465 		char *a_target;
1466 	} */ *ap;
1467 {
1468 	return (EOPNOTSUPP);
1469 }
1470 
1471 static int
1472 msdosfs_readdir(ap)
1473 	struct vop_readdir_args /* {
1474 		struct vnode *a_vp;
1475 		struct uio *a_uio;
1476 		struct ucred *a_cred;
1477 		int *a_eofflag;
1478 		int *a_ncookies;
1479 		u_long **a_cookies;
1480 	} */ *ap;
1481 {
1482 	int error = 0;
1483 	int diff;
1484 	long n;
1485 	int blsize;
1486 	long on;
1487 	u_long cn;
1488 	u_long fileno;
1489 	u_long dirsperblk;
1490 	long bias = 0;
1491 	daddr_t bn, lbn;
1492 	struct buf *bp;
1493 	struct denode *dep = VTODE(ap->a_vp);
1494 	struct msdosfsmount *pmp = dep->de_pmp;
1495 	struct direntry *dentp;
1496 	struct dirent dirbuf;
1497 	struct uio *uio = ap->a_uio;
1498 	u_long *cookies = NULL;
1499 	int ncookies = 0;
1500 	off_t offset, off;
1501 	int chksum = -1;
1502 
1503 #ifdef MSDOSFS_DEBUG
1504 	printf("msdosfs_readdir(): vp %p, uio %p, cred %p, eofflagp %p\n",
1505 	    ap->a_vp, uio, ap->a_cred, ap->a_eofflag);
1506 #endif
1507 
1508 	/*
1509 	 * msdosfs_readdir() won't operate properly on regular files since
1510 	 * it does i/o only with the the filesystem vnode, and hence can
1511 	 * retrieve the wrong block from the buffer cache for a plain file.
1512 	 * So, fail attempts to readdir() on a plain file.
1513 	 */
1514 	if ((dep->de_Attributes & ATTR_DIRECTORY) == 0)
1515 		return (ENOTDIR);
1516 
1517 	/*
1518 	 * To be safe, initialize dirbuf
1519 	 */
1520 	bzero(dirbuf.d_name, sizeof(dirbuf.d_name));
1521 
1522 	/*
1523 	 * If the user buffer is smaller than the size of one dos directory
1524 	 * entry or the file offset is not a multiple of the size of a
1525 	 * directory entry, then we fail the read.
1526 	 */
1527 	off = offset = uio->uio_offset;
1528 	if (uio->uio_resid < sizeof(struct direntry) ||
1529 	    (offset & (sizeof(struct direntry) - 1)))
1530 		return (EINVAL);
1531 
1532 	if (ap->a_ncookies) {
1533 		ncookies = uio->uio_resid / 16;
1534 		MALLOC(cookies, u_long *, ncookies * sizeof(u_long), M_TEMP,
1535 		       M_WAITOK);
1536 		*ap->a_cookies = cookies;
1537 		*ap->a_ncookies = ncookies;
1538 	}
1539 
1540 	dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
1541 
1542 	/*
1543 	 * If they are reading from the root directory then, we simulate
1544 	 * the . and .. entries since these don't exist in the root
1545 	 * directory.  We also set the offset bias to make up for having to
1546 	 * simulate these entries. By this I mean that at file offset 64 we
1547 	 * read the first entry in the root directory that lives on disk.
1548 	 */
1549 	if (dep->de_StartCluster == MSDOSFSROOT
1550 	    || (FAT32(pmp) && dep->de_StartCluster == pmp->pm_rootdirblk)) {
1551 #if 0
1552 		printf("msdosfs_readdir(): going after . or .. in root dir, offset %d\n",
1553 		    offset);
1554 #endif
1555 		bias = 2 * sizeof(struct direntry);
1556 		if (offset < bias) {
1557 			for (n = (int)offset / sizeof(struct direntry);
1558 			     n < 2; n++) {
1559 				if (FAT32(pmp))
1560 					dirbuf.d_fileno = cntobn(pmp,
1561 								 pmp->pm_rootdirblk)
1562 							  * dirsperblk;
1563 				else
1564 					dirbuf.d_fileno = 1;
1565 				dirbuf.d_type = DT_DIR;
1566 				switch (n) {
1567 				case 0:
1568 					dirbuf.d_namlen = 1;
1569 					strcpy(dirbuf.d_name, ".");
1570 					break;
1571 				case 1:
1572 					dirbuf.d_namlen = 2;
1573 					strcpy(dirbuf.d_name, "..");
1574 					break;
1575 				}
1576 				dirbuf.d_reclen = GENERIC_DIRSIZ(&dirbuf);
1577 				if (uio->uio_resid < dirbuf.d_reclen)
1578 					goto out;
1579 				error = uiomove((caddr_t) &dirbuf,
1580 						dirbuf.d_reclen, uio);
1581 				if (error)
1582 					goto out;
1583 				offset += sizeof(struct direntry);
1584 				off = offset;
1585 				if (cookies) {
1586 					*cookies++ = offset;
1587 					if (--ncookies <= 0)
1588 						goto out;
1589 				}
1590 			}
1591 		}
1592 	}
1593 
1594 	off = offset;
1595 	while (uio->uio_resid > 0) {
1596 		lbn = de_cluster(pmp, offset - bias);
1597 		on = (offset - bias) & pmp->pm_crbomask;
1598 		n = min(pmp->pm_bpcluster - on, uio->uio_resid);
1599 		diff = dep->de_FileSize - (offset - bias);
1600 		if (diff <= 0)
1601 			break;
1602 		n = min(n, diff);
1603 		error = pcbmap(dep, lbn, &bn, &cn, &blsize);
1604 		if (error)
1605 			break;
1606 		error = bread(pmp->pm_devvp, bn, blsize, NOCRED, &bp);
1607 		if (error) {
1608 			brelse(bp);
1609 			return (error);
1610 		}
1611 		n = min(n, blsize - bp->b_resid);
1612 
1613 		/*
1614 		 * Convert from dos directory entries to fs-independent
1615 		 * directory entries.
1616 		 */
1617 		for (dentp = (struct direntry *)(bp->b_data + on);
1618 		     (char *)dentp < bp->b_data + on + n;
1619 		     dentp++, offset += sizeof(struct direntry)) {
1620 #if 0
1621 			printf("rd: dentp %08x prev %08x crnt %08x deName %02x attr %02x\n",
1622 			    dentp, prev, crnt, dentp->deName[0], dentp->deAttributes);
1623 #endif
1624 			/*
1625 			 * If this is an unused entry, we can stop.
1626 			 */
1627 			if (dentp->deName[0] == SLOT_EMPTY) {
1628 				brelse(bp);
1629 				goto out;
1630 			}
1631 			/*
1632 			 * Skip deleted entries.
1633 			 */
1634 			if (dentp->deName[0] == SLOT_DELETED) {
1635 				chksum = -1;
1636 				continue;
1637 			}
1638 
1639 			/*
1640 			 * Handle Win95 long directory entries
1641 			 */
1642 			if (dentp->deAttributes == ATTR_WIN95) {
1643 				if (pmp->pm_flags & MSDOSFSMNT_SHORTNAME)
1644 					continue;
1645 				chksum = win2unixfn((struct winentry *)dentp,
1646 					&dirbuf, chksum,
1647 					pmp->pm_flags & MSDOSFSMNT_U2WTABLE,
1648 					pmp->pm_u2w);
1649 				continue;
1650 			}
1651 
1652 			/*
1653 			 * Skip volume labels
1654 			 */
1655 			if (dentp->deAttributes & ATTR_VOLUME) {
1656 				chksum = -1;
1657 				continue;
1658 			}
1659 			/*
1660 			 * This computation of d_fileno must match
1661 			 * the computation of va_fileid in
1662 			 * msdosfs_getattr.
1663 			 */
1664 			if (dentp->deAttributes & ATTR_DIRECTORY) {
1665 				fileno = getushort(dentp->deStartCluster);
1666 				if (FAT32(pmp))
1667 					fileno |= getushort(dentp->deHighClust) << 16;
1668 				/* if this is the root directory */
1669 				if (fileno == MSDOSFSROOT)
1670 					if (FAT32(pmp))
1671 						fileno = cntobn(pmp,
1672 								pmp->pm_rootdirblk)
1673 							 * dirsperblk;
1674 					else
1675 						fileno = 1;
1676 				else
1677 					fileno = cntobn(pmp, fileno) * dirsperblk;
1678 				dirbuf.d_fileno = fileno;
1679 				dirbuf.d_type = DT_DIR;
1680 			} else {
1681 				dirbuf.d_fileno = offset / sizeof(struct direntry);
1682 				dirbuf.d_type = DT_REG;
1683 			}
1684 			if (chksum != winChksum(dentp->deName))
1685 				dirbuf.d_namlen = dos2unixfn(dentp->deName,
1686 				    (u_char *)dirbuf.d_name,
1687 				    dentp->deLowerCase |
1688 					((pmp->pm_flags & MSDOSFSMNT_SHORTNAME) ?
1689 					(LCASE_BASE | LCASE_EXT) : 0),
1690 				    pmp->pm_flags & MSDOSFSMNT_U2WTABLE,
1691 				    pmp->pm_d2u,
1692 				    pmp->pm_flags & MSDOSFSMNT_ULTABLE,
1693 				    pmp->pm_ul);
1694 			else
1695 				dirbuf.d_name[dirbuf.d_namlen] = 0;
1696 			chksum = -1;
1697 			dirbuf.d_reclen = GENERIC_DIRSIZ(&dirbuf);
1698 			if (uio->uio_resid < dirbuf.d_reclen) {
1699 				brelse(bp);
1700 				goto out;
1701 			}
1702 			error = uiomove((caddr_t) &dirbuf,
1703 					dirbuf.d_reclen, uio);
1704 			if (error) {
1705 				brelse(bp);
1706 				goto out;
1707 			}
1708 			if (cookies) {
1709 				*cookies++ = offset + sizeof(struct direntry);
1710 				if (--ncookies <= 0) {
1711 					brelse(bp);
1712 					goto out;
1713 				}
1714 			}
1715 			off = offset + sizeof(struct direntry);
1716 		}
1717 		brelse(bp);
1718 	}
1719 out:
1720 	/* Subtract unused cookies */
1721 	if (ap->a_ncookies)
1722 		*ap->a_ncookies -= ncookies;
1723 
1724 	uio->uio_offset = off;
1725 
1726 	/*
1727 	 * Set the eofflag (NFS uses it)
1728 	 */
1729 	if (ap->a_eofflag) {
1730 		if (dep->de_FileSize - (offset - bias) <= 0)
1731 			*ap->a_eofflag = 1;
1732 		else
1733 			*ap->a_eofflag = 0;
1734 	}
1735 	return (error);
1736 }
1737 
1738 /*
1739  * vp  - address of vnode file the file
1740  * bn  - which cluster we are interested in mapping to a filesystem block number.
1741  * vpp - returns the vnode for the block special file holding the filesystem
1742  *	 containing the file of interest
1743  * bnp - address of where to return the filesystem relative block number
1744  */
1745 static int
1746 msdosfs_bmap(ap)
1747 	struct vop_bmap_args /* {
1748 		struct vnode *a_vp;
1749 		daddr_t a_bn;
1750 		struct vnode **a_vpp;
1751 		daddr_t *a_bnp;
1752 		int *a_runp;
1753 		int *a_runb;
1754 	} */ *ap;
1755 {
1756 	struct denode *dep = VTODE(ap->a_vp);
1757 
1758 	if (ap->a_vpp != NULL)
1759 		*ap->a_vpp = dep->de_devvp;
1760 	if (ap->a_bnp == NULL)
1761 		return (0);
1762 	if (ap->a_runp) {
1763 		/*
1764 		 * Sequential clusters should be counted here.
1765 		 */
1766 		*ap->a_runp = 0;
1767 	}
1768 	if (ap->a_runb) {
1769 		*ap->a_runb = 0;
1770 	}
1771 	return (pcbmap(dep, ap->a_bn, ap->a_bnp, 0, 0));
1772 }
1773 
1774 static int
1775 msdosfs_strategy(ap)
1776 	struct vop_strategy_args /* {
1777 		struct vnode *a_vp;
1778 		struct buf *a_bp;
1779 	} */ *ap;
1780 {
1781 	struct buf *bp = ap->a_bp;
1782 	struct denode *dep = VTODE(bp->b_vp);
1783 	struct vnode *vp;
1784 	int error = 0;
1785 
1786 	if (bp->b_vp->v_type == VBLK || bp->b_vp->v_type == VCHR)
1787 		panic("msdosfs_strategy: spec");
1788 	/*
1789 	 * If we don't already know the filesystem relative block number
1790 	 * then get it using pcbmap().  If pcbmap() returns the block
1791 	 * number as -1 then we've got a hole in the file.  DOS filesystems
1792 	 * don't allow files with holes, so we shouldn't ever see this.
1793 	 */
1794 	if (bp->b_blkno == bp->b_lblkno) {
1795 		error = pcbmap(dep, bp->b_lblkno, &bp->b_blkno, 0, 0);
1796 		if (error) {
1797 			bp->b_error = error;
1798 			bp->b_ioflags |= BIO_ERROR;
1799 			bufdone(bp);
1800 			return (error);
1801 		}
1802 		if ((long)bp->b_blkno == -1)
1803 			vfs_bio_clrbuf(bp);
1804 	}
1805 	if (bp->b_blkno == -1) {
1806 		bufdone(bp);
1807 		return (0);
1808 	}
1809 	/*
1810 	 * Read/write the block from/to the disk that contains the desired
1811 	 * file block.
1812 	 */
1813 	vp = dep->de_devvp;
1814 	bp->b_dev = vp->v_rdev;
1815 	VOP_STRATEGY(vp, bp);
1816 	return (0);
1817 }
1818 
1819 static int
1820 msdosfs_print(ap)
1821 	struct vop_print_args /* {
1822 		struct vnode *vp;
1823 	} */ *ap;
1824 {
1825 	struct denode *dep = VTODE(ap->a_vp);
1826 
1827 	printf(
1828 	    "tag VT_MSDOSFS, startcluster %lu, dircluster %lu, diroffset %lu ",
1829 	       dep->de_StartCluster, dep->de_dirclust, dep->de_diroffset);
1830 	printf(" dev %d, %d", major(dep->de_dev), minor(dep->de_dev));
1831 	lockmgr_printinfo(&ap->a_vp->v_lock);
1832 	printf("\n");
1833 	return (0);
1834 }
1835 
1836 static int
1837 msdosfs_pathconf(ap)
1838 	struct vop_pathconf_args /* {
1839 		struct vnode *a_vp;
1840 		int a_name;
1841 		int *a_retval;
1842 	} */ *ap;
1843 {
1844 	struct msdosfsmount *pmp = VTODE(ap->a_vp)->de_pmp;
1845 
1846 	switch (ap->a_name) {
1847 	case _PC_LINK_MAX:
1848 		*ap->a_retval = 1;
1849 		return (0);
1850 	case _PC_NAME_MAX:
1851 		*ap->a_retval = pmp->pm_flags & MSDOSFSMNT_LONGNAME ? WIN_MAXLEN : 12;
1852 		return (0);
1853 	case _PC_PATH_MAX:
1854 		*ap->a_retval = PATH_MAX;
1855 		return (0);
1856 	case _PC_CHOWN_RESTRICTED:
1857 		*ap->a_retval = 1;
1858 		return (0);
1859 	case _PC_NO_TRUNC:
1860 		*ap->a_retval = 0;
1861 		return (0);
1862 	default:
1863 		return (EINVAL);
1864 	}
1865 	/* NOTREACHED */
1866 }
1867 
1868 /*
1869  * get page routine
1870  *
1871  * XXX By default, wimp out... note that a_offset is ignored (and always
1872  * XXX has been).
1873  */
1874 int
1875 msdosfs_getpages(ap)
1876 	struct vop_getpages_args *ap;
1877 {
1878 	return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
1879 		ap->a_reqpage);
1880 }
1881 
1882 /*
1883  * put page routine
1884  *
1885  * XXX By default, wimp out... note that a_offset is ignored (and always
1886  * XXX has been).
1887  */
1888 int
1889 msdosfs_putpages(ap)
1890 	struct vop_putpages_args *ap;
1891 {
1892 	return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count,
1893 		ap->a_sync, ap->a_rtvals);
1894 }
1895 
1896 /* Global vfs data structures for msdosfs */
1897 vop_t **msdosfs_vnodeop_p;
1898 static struct vnodeopv_entry_desc msdosfs_vnodeop_entries[] = {
1899 	{ &vop_default_desc,		(vop_t *) vop_defaultop },
1900 	{ &vop_access_desc,		(vop_t *) msdosfs_access },
1901 	{ &vop_bmap_desc,		(vop_t *) msdosfs_bmap },
1902 	{ &vop_cachedlookup_desc,	(vop_t *) msdosfs_lookup },
1903 	{ &vop_close_desc,		(vop_t *) msdosfs_close },
1904 	{ &vop_create_desc,		(vop_t *) msdosfs_create },
1905 	{ &vop_fsync_desc,		(vop_t *) msdosfs_fsync },
1906 	{ &vop_getattr_desc,		(vop_t *) msdosfs_getattr },
1907 	{ &vop_inactive_desc,		(vop_t *) msdosfs_inactive },
1908 	{ &vop_islocked_desc,		(vop_t *) vop_stdislocked },
1909 	{ &vop_link_desc,		(vop_t *) msdosfs_link },
1910 	{ &vop_lock_desc,		(vop_t *) vop_stdlock },
1911 	{ &vop_lookup_desc,		(vop_t *) vfs_cache_lookup },
1912 	{ &vop_mkdir_desc,		(vop_t *) msdosfs_mkdir },
1913 	{ &vop_mknod_desc,		(vop_t *) msdosfs_mknod },
1914 	{ &vop_pathconf_desc,		(vop_t *) msdosfs_pathconf },
1915 	{ &vop_print_desc,		(vop_t *) msdosfs_print },
1916 	{ &vop_read_desc,		(vop_t *) msdosfs_read },
1917 	{ &vop_readdir_desc,		(vop_t *) msdosfs_readdir },
1918 	{ &vop_reclaim_desc,		(vop_t *) msdosfs_reclaim },
1919 	{ &vop_remove_desc,		(vop_t *) msdosfs_remove },
1920 	{ &vop_rename_desc,		(vop_t *) msdosfs_rename },
1921 	{ &vop_rmdir_desc,		(vop_t *) msdosfs_rmdir },
1922 	{ &vop_setattr_desc,		(vop_t *) msdosfs_setattr },
1923 	{ &vop_strategy_desc,		(vop_t *) msdosfs_strategy },
1924 	{ &vop_symlink_desc,		(vop_t *) msdosfs_symlink },
1925 	{ &vop_unlock_desc,		(vop_t *) vop_stdunlock },
1926 	{ &vop_write_desc,		(vop_t *) msdosfs_write },
1927 	{ &vop_getpages_desc,		(vop_t *) msdosfs_getpages },
1928 	{ &vop_putpages_desc,		(vop_t *) msdosfs_putpages },
1929 	{ NULL, NULL }
1930 };
1931 static struct vnodeopv_desc msdosfs_vnodeop_opv_desc =
1932 	{ &msdosfs_vnodeop_p, msdosfs_vnodeop_entries };
1933 
1934 VNODEOP_SET(msdosfs_vnodeop_opv_desc);
1935