xref: /freebsd/sys/fs/msdosfs/msdosfs_vfsops.c (revision 3e0f6b97b257a96f7275e4442204263e44b16686)
1 /*	$FreeBSD$ */
2 /*	$NetBSD: msdosfs_vfsops.c,v 1.19 1994/08/21 18:44:10 ws Exp $	*/
3 
4 /*-
5  * Copyright (C) 1994 Wolfgang Solfrank.
6  * Copyright (C) 1994 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/proc.h>
55 #include <sys/kernel.h>
56 #include <sys/vnode.h>
57 #include <miscfs/specfs/specdev.h> /* XXX */	/* defines v_rdev */
58 #include <sys/mount.h>
59 #include <sys/buf.h>
60 #include <sys/file.h>
61 #include <sys/malloc.h>
62 
63 #include <msdosfs/bpb.h>
64 #include <msdosfs/bootsect.h>
65 #include <msdosfs/direntry.h>
66 #include <msdosfs/denode.h>
67 #include <msdosfs/msdosfsmount.h>
68 #include <msdosfs/fat.h>
69 
70 static int msdosfsdoforce = 1;		/* 1 = force unmount */
71 
72 static int	mountmsdosfs __P((struct vnode *devvp, struct mount *mp,
73 				  struct proc *p));
74 static int	msdosfs_fhtovp __P((struct mount *, struct fid *,
75 				    struct mbuf *, struct vnode **, int *,
76 				    struct ucred **));
77 static int	msdosfs_mount __P((struct mount *, char *, caddr_t,
78 				   struct nameidata *, struct proc *));
79 static int	msdosfs_quotactl __P((struct mount *, int, uid_t, caddr_t,
80 				      struct proc *));
81 static int	msdosfs_root __P((struct mount *, struct vnode **));
82 static int	msdosfs_start __P((struct mount *, int, struct proc *));
83 static int	msdosfs_statfs __P((struct mount *, struct statfs *,
84 				    struct proc *));
85 static int	msdosfs_sync __P((struct mount *, int, struct ucred *,
86 				  struct proc *));
87 static int	msdosfs_unmount __P((struct mount *, int, struct proc *));
88 static int	msdosfs_vget __P((struct mount *mp, ino_t ino,
89 				  struct vnode **vpp));
90 static int	msdosfs_vptofh __P((struct vnode *, struct fid *));
91 
92 /*
93  * mp - path - addr in user space of mount point (ie /usr or whatever)
94  * data - addr in user space of mount params including the name of the block
95  * special file to treat as a filesystem.
96  */
97 static int
98 msdosfs_mount(mp, path, data, ndp, p)
99 	struct mount *mp;
100 	char *path;
101 	caddr_t data;
102 	struct nameidata *ndp;
103 	struct proc *p;
104 {
105 	struct vnode *devvp;	  /* vnode for blk device to mount */
106 	struct msdosfs_args args; /* will hold data from mount request */
107 	struct msdosfsmount *pmp; /* msdosfs specific mount control block */
108 	int error, flags;
109 	u_int size;
110 	struct ucred *cred, *scred;
111 	struct vattr va;
112 
113 	/*
114 	 * Copy in the args for the mount request.
115 	 */
116 	error = copyin(data, (caddr_t) & args, sizeof(struct msdosfs_args));
117 	if (error)
118 		return error;
119 
120 	/*
121 	 * If they just want to update then be sure we can do what is
122 	 * asked.  Can't change a filesystem from read/write to read only.
123 	 * Why? And if they've supplied a new device file name then we
124 	 * continue, otherwise return.
125 	 */
126 	if (mp->mnt_flag & MNT_UPDATE) {
127 		pmp = (struct msdosfsmount *) mp->mnt_data;
128 		error = 0;
129 		if (pmp->pm_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) {
130 			flags = WRITECLOSE;
131 			if (mp->mnt_flag & MNT_FORCE)
132 				flags |= FORCECLOSE;
133 			if (vfs_busy(mp, LK_NOWAIT, 0, p))
134 				return EBUSY;
135 			error = vflush(mp, NULLVP, flags);
136 			vfs_unbusy(mp, p);
137 		}
138 		if (!error && (mp->mnt_flag & MNT_RELOAD))
139 			/* not yet implemented */
140 			error = EINVAL;
141 		if (error)
142 			return error;
143 		if (pmp->pm_ronly && (mp->mnt_flag & MNT_RDONLY) == 0)
144 			pmp->pm_ronly = 0;
145 		if (args.fspec == 0) {
146 			/*
147 			 * Process export requests.
148 			 */
149 			return vfs_export(mp, &pmp->pm_export, &args.export);
150 		}
151 	} else
152 		pmp = NULL;
153 
154 	/*
155 	 * check to see that the user in owns the target directory.
156 	 * Note the very XXX trick to make sure we're checking as the
157 	 * real user -- were mount() executable by anyone, this wouldn't
158 	 * be a problem.
159 	 *
160 	 * XXX there should be one consistent error out.
161 	 */
162 	cred = crdup(p->p_ucred);			/* XXX */
163 	cred->cr_uid = p->p_cred->p_ruid;		/* XXX */
164 	error = VOP_GETATTR(mp->mnt_vnodecovered, &va, cred, p);
165 	if (error) {
166 		crfree(cred);				/* XXX */
167 		return error;
168 	}
169 	if (cred->cr_uid != 0) {
170 		if (va.va_uid != cred->cr_uid) {
171 			error = EACCES;
172 			crfree(cred);			/* XXX */
173 			return error;
174 		}
175 
176 		/* a user mounted it; we'll verify permissions when unmounting */
177 		mp->mnt_flag |= MNT_USER;
178 	}
179 
180 	/*
181 	 * Now, lookup the name of the block device this mount or name
182 	 * update request is to apply to.
183 	 */
184 	NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, p);
185 	scred = p->p_ucred;				/* XXX */
186 	p->p_ucred = cred;				/* XXX */
187 	error = namei(ndp);
188 	p->p_ucred = scred;				/* XXX */
189 	crfree(cred);					/* XXX */
190 	if (error != 0)
191 		return error;
192 
193 	/*
194 	 * Be sure they've given us a block device to treat as a
195 	 * filesystem.  And, that its major number is within the bdevsw
196 	 * table.
197 	 */
198 	devvp = ndp->ni_vp;
199 	if (devvp->v_type != VBLK) {
200 		vrele(devvp);
201 		return ENOTBLK;
202 	}
203 	if (major(devvp->v_rdev) >= nblkdev) {
204 		vrele(devvp);
205 		return ENXIO;
206 	}
207 
208 	/*
209 	 * If this is an update, then make sure the vnode for the block
210 	 * special device is the same as the one our filesystem is in.
211 	 */
212 	if (mp->mnt_flag & MNT_UPDATE) {
213 		if (devvp != pmp->pm_devvp)
214 			error = EINVAL;
215 		else
216 			vrele(devvp);
217 	} else {
218 
219 		/*
220 		 * Well, it's not an update, it's a real mount request.
221 		 * Time to get dirty.
222 		 */
223 		error = mountmsdosfs(devvp, mp, p);
224 	}
225 	if (error) {
226 		vrele(devvp);
227 		return error;
228 	}
229 
230 	/*
231 	 * Copy in the name of the directory the filesystem is to be
232 	 * mounted on. Then copy in the name of the block special file
233 	 * representing the filesystem being mounted. And we clear the
234 	 * remainder of the character strings to be tidy. Set up the
235 	 * user id/group id/mask as specified by the user. Then, we try to
236 	 * fill in the filesystem stats structure as best we can with
237 	 * whatever applies from a dos file system.
238 	 */
239 	pmp = (struct msdosfsmount *) mp->mnt_data;
240 	copyinstr(path, (caddr_t) mp->mnt_stat.f_mntonname,
241 	    sizeof(mp->mnt_stat.f_mntonname) - 1, &size);
242 	bzero(mp->mnt_stat.f_mntonname + size,
243 	    sizeof(mp->mnt_stat.f_mntonname) - size);
244 	copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
245 	bzero(mp->mnt_stat.f_mntfromname + size,
246 	    MNAMELEN - size);
247 	pmp->pm_mounter = p->p_cred->p_ruid;
248 	pmp->pm_gid = args.gid;
249 	pmp->pm_uid = args.uid;
250 	pmp->pm_mask = args.mask;
251 	(void) msdosfs_statfs(mp, &mp->mnt_stat, p);
252 #ifdef MSDOSFS_DEBUG
253 	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
254 #endif
255 	return 0;
256 }
257 
258 static int
259 mountmsdosfs(devvp, mp, p)
260 	struct vnode *devvp;
261 	struct mount *mp;
262 	struct proc *p;
263 {
264 	int i;
265 	int bpc;
266 	int bit;
267 	int error;
268 	int needclose;
269 	int ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
270 	dev_t dev = devvp->v_rdev;
271 	union bootsector *bsp;
272 	struct msdosfsmount *pmp = NULL;
273 	struct buf *bp0 = NULL;
274 	struct byte_bpb33 *b33;
275 	struct byte_bpb50 *b50;
276 #ifdef	PC98
277 	u_int	pc98_wrk;
278 	u_int	Phy_Sector_Size;
279 #endif
280 
281 	/*
282 	 * Multiple mounts of the same block special file aren't allowed.
283 	 * Make sure no one else has the special file open.  And flush any
284 	 * old buffers from this filesystem.  Presumably this prevents us
285 	 * from running into buffers that are the wrong blocksize.
286 	 */
287 	error = vfs_mountedon(devvp);
288 	if (error)
289 		return error;
290 	if (vcount(devvp) > 1)
291 		return EBUSY;
292 	error = vinvalbuf(devvp, V_SAVE, p->p_ucred, p, 0, 0);
293 	if (error)
294 		return error;
295 
296 	/*
297 	 * Now open the block special file.
298 	 */
299 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD | FWRITE, FSCRED, p);
300 	if (error)
301 		return error;
302 	needclose = 1;
303 #ifdef HDSUPPORT
304 	/*
305 	 * Put this in when we support reading dos filesystems from
306 	 * partitioned harddisks.
307 	 */
308 	if (VOP_IOCTL(devvp, DIOCGPART, &msdosfspart, FREAD, NOCRED, p) == 0) {
309 	}
310 #endif
311 
312 	/*
313 	 * Read the boot sector of the filesystem, and then check the boot
314 	 * signature.  If not a dos boot sector then error out.  We could
315 	 * also add some checking on the bsOemName field.  So far I've seen
316 	 * the following values: "IBM  3.3" "MSDOS3.3" "MSDOS5.0"
317 	 */
318 #ifdef	PC98
319 	devvp->v_flag &= 0xffff;
320 	error = bread(devvp, 0, 1024, NOCRED, &bp0);
321 #else
322 	error = bread(devvp, 0, 512, NOCRED, &bp0);
323 #endif
324 	if (error)
325 		goto error_exit;
326 	bp0->b_flags |= B_AGE;
327 	bsp = (union bootsector *) bp0->b_data;
328 	b33 = (struct byte_bpb33 *) bsp->bs33.bsBPB;
329 	b50 = (struct byte_bpb50 *) bsp->bs50.bsBPB;
330 #ifdef MSDOSFS_CHECKSIG
331 #ifdef	PC98
332 	if (bsp->bs50.bsBootSectSig != BOOTSIG &&
333 	    bsp->bs50.bsBootSectSig != 0 &&		/* PC98 DOS 3.3x */
334 	    bsp->bs50.bsBootSectSig != 15760 &&		/* PC98 DOS 5.0	 */
335 	    bsp->bs50.bsBootSectSig != 64070) {		/* PC98 DOS 3.3B */
336 #else
337 	if (bsp->bs50.bsBootSectSig != BOOTSIG) {
338 #endif
339 		error = EINVAL;
340 		goto error_exit;
341 	}
342 #endif
343 	if ( bsp->bs50.bsJump[0] != 0xe9 &&
344 	    (bsp->bs50.bsJump[0] != 0xeb || bsp->bs50.bsJump[2] != 0x90)) {
345 		error = EINVAL;
346 		goto error_exit;
347 	}
348 
349 	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
350 	bzero((caddr_t)pmp, sizeof *pmp);
351 	pmp->pm_mountp = mp;
352 
353 	/*
354 	 * Compute several useful quantities from the bpb in the
355 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
356 	 * the fields that are different between dos 5 and dos 3.3.
357 	 */
358 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
359 	pmp->pm_SectPerClust = b50->bpbSecPerClust;
360 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
361 	pmp->pm_FATs = b50->bpbFATs;
362 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
363 	pmp->pm_Sectors = getushort(b50->bpbSectors);
364 	pmp->pm_Media = b50->bpbMedia;
365 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
366 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
367 	pmp->pm_Heads = getushort(b50->bpbHeads);
368 
369 	/* XXX - We should probably check more values here */
370     	if (!pmp->pm_BytesPerSec || !pmp->pm_SectPerClust ||
371 	    !pmp->pm_Heads || pmp->pm_Heads > 255 ||
372 #ifdef PC98
373 	    !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 255) {
374 #else
375 	    !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 63) {
376 #endif
377 		error = EINVAL;
378 		goto error_exit;
379 	}
380 
381 	if (pmp->pm_Sectors == 0) {
382 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
383 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
384 	} else {
385 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
386 		pmp->pm_HugeSectors = pmp->pm_Sectors;
387 	}
388 #ifdef	PC98	/* for PC98		added Satoshi Yasuda	*/
389 	Phy_Sector_Size = 512;
390 	if ((devvp->v_rdev>>8) == 2) {	/* floppy check */
391 		if (((devvp->v_rdev&077) == 2) && (pmp->pm_HugeSectors == 1232)) {
392 				Phy_Sector_Size = 1024;	/* 2HD */
393 				/*
394 				 * 1024byte/sector support
395 				 */
396 				devvp->v_flag |= 0x10000;
397 		} else {
398 			if ((((devvp->v_rdev&077) == 3)	/* 2DD 8 or 9 sector */
399 				&& (pmp->pm_HugeSectors == 1440)) /* 9 sector */
400 				|| (((devvp->v_rdev&077) == 4)
401 				&& (pmp->pm_HugeSectors == 1280)) /* 8 sector */
402 				|| (((devvp->v_rdev&077) == 5)
403 				&& (pmp->pm_HugeSectors == 2880))) { /* 1.44M */
404 					Phy_Sector_Size = 512;
405 			} else {
406 				if (((devvp->v_rdev&077) != 1)
407 				    && ((devvp->v_rdev&077) != 0)) { /* 2HC */
408 					error = EINVAL;
409 					goto error_exit;
410 				}
411 			}
412 		}
413 	}
414 	pc98_wrk = pmp->pm_BytesPerSec / Phy_Sector_Size;
415 	pmp->pm_BytesPerSec = Phy_Sector_Size;
416 	pmp->pm_SectPerClust = pmp->pm_SectPerClust * pc98_wrk;
417 	pmp->pm_HugeSectors = pmp->pm_HugeSectors * pc98_wrk;
418 	pmp->pm_ResSectors = pmp->pm_ResSectors * pc98_wrk;
419 	pmp->pm_FATsecs = pmp->pm_FATsecs * pc98_wrk;
420 	pmp->pm_SecPerTrack = pmp->pm_SecPerTrack * pc98_wrk;
421 	pmp->pm_HiddenSects = pmp->pm_HiddenSects * pc98_wrk;
422 #endif			/*						*/
423 	pmp->pm_fatblk = pmp->pm_ResSectors;
424 	pmp->pm_rootdirblk = pmp->pm_fatblk +
425 	    (pmp->pm_FATs * pmp->pm_FATsecs);
426 	pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry))
427 	    /
428 	    pmp->pm_BytesPerSec;/* in sectors */
429 	pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
430 	pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
431 	    pmp->pm_SectPerClust;
432 	pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
433 	pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
434 	if (FAT12(pmp))
435 		/*
436 		 * This will usually be a floppy disk. This size makes sure
437 		 * that one fat entry will not be split across multiple
438 		 * blocks.
439 		 */
440 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
441 	else
442 		/*
443 		 * This will usually be a hard disk. Reading or writing one
444 		 * block should be quite fast.
445 		 */
446 		pmp->pm_fatblocksize = MAXBSIZE;
447 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
448 
449 
450 	if ((pmp->pm_rootdirsize % pmp->pm_SectPerClust) != 0)
451 		printf("mountmsdosfs(): Warning: root directory is not a multiple of the clustersize in length\n");
452 
453 	/*
454 	 * Compute mask and shift value for isolating cluster relative byte
455 	 * offsets and cluster numbers from a file offset.
456 	 */
457 	bpc = pmp->pm_SectPerClust * pmp->pm_BytesPerSec;
458 	pmp->pm_bpcluster = bpc;
459 	pmp->pm_depclust = bpc / sizeof(struct direntry);
460 	pmp->pm_crbomask = bpc - 1;
461 	if (bpc == 0) {
462 		error = EINVAL;
463 		goto error_exit;
464 	}
465 	bit = 1;
466 	for (i = 0; i < 32; i++) {
467 		if (bit & bpc) {
468 			if (bit ^ bpc) {
469 				error = EINVAL;
470 				goto error_exit;
471 			}
472 			pmp->pm_cnshift = i;
473 			break;
474 		}
475 		bit <<= 1;
476 	}
477 
478 #ifdef	PC98
479 	if (Phy_Sector_Size == 512) {
480 		pmp->pm_brbomask = 0x01ff;	/* 512 byte blocks only (so far) */
481 		pmp->pm_bnshift = 9;	/* shift right 9 bits to get bn */
482 	} else {
483 		pmp->pm_brbomask = 0x03ff;
484 		pmp->pm_bnshift = 10;
485 	}
486 #else
487 	pmp->pm_brbomask = 0x01ff;	/* 512 byte blocks only (so far) */
488 	pmp->pm_bnshift = 9;	/* shift right 9 bits to get bn */
489 #endif
490 
491 	/*
492 	 * Release the bootsector buffer.
493 	 */
494 	brelse(bp0);
495 	bp0 = NULL;
496 
497 	/*
498 	 * Allocate memory for the bitmap of allocated clusters, and then
499 	 * fill it in.
500 	 */
501 	pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
502 				   / N_INUSEBITS)
503 				  * sizeof(*pmp->pm_inusemap),
504 				  M_MSDOSFSFAT, M_WAITOK);
505 
506 	/*
507 	 * fillinusemap() needs pm_devvp.
508 	 */
509 	pmp->pm_dev = dev;
510 	pmp->pm_devvp = devvp;
511 
512 	/*
513 	 * Have the inuse map filled in.
514 	 */
515 	error = fillinusemap(pmp);
516 	if (error)
517 		goto error_exit;
518 
519 	/*
520 	 * If they want fat updates to be synchronous then let them suffer
521 	 * the performance degradation in exchange for the on disk copy of
522 	 * the fat being correct just about all the time.  I suppose this
523 	 * would be a good thing to turn on if the kernel is still flakey.
524 	 */
525 	pmp->pm_waitonfat = mp->mnt_flag & MNT_SYNCHRONOUS;
526 
527 	/*
528 	 * Finish up.
529 	 */
530 	pmp->pm_ronly = ronly;
531 	if (ronly == 0)
532 		pmp->pm_fmod = 1;
533 	mp->mnt_data = (qaddr_t) pmp;
534         mp->mnt_stat.f_fsid.val[0] = (long)dev;
535         mp->mnt_stat.f_fsid.val[1] = MOUNT_MSDOS;
536 	mp->mnt_flag |= MNT_LOCAL;
537 	devvp->v_specflags |= SI_MOUNTEDON;
538 
539 	return 0;
540 
541 error_exit:;
542 	if (bp0)
543 		brelse(bp0);
544 	if (needclose)
545 		(void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE,
546 		    NOCRED, p);
547 	if (pmp) {
548 		if (pmp->pm_inusemap)
549 			free((caddr_t) pmp->pm_inusemap, M_MSDOSFSFAT);
550 		free((caddr_t) pmp, M_MSDOSFSMNT);
551 		mp->mnt_data = (qaddr_t) 0;
552 	}
553 	return error;
554 }
555 
556 static int
557 msdosfs_start(mp, flags, p)
558 	struct mount *mp;
559 	int flags;
560 	struct proc *p;
561 {
562 	return 0;
563 }
564 
565 /*
566  * Unmount the filesystem described by mp.
567  */
568 static int
569 msdosfs_unmount(mp, mntflags, p)
570 	struct mount *mp;
571 	int mntflags;
572 	struct proc *p;
573 {
574 	int flags = 0;
575 	int error;
576 	struct msdosfsmount *pmp = (struct msdosfsmount *) mp->mnt_data;
577 
578 	/* only the mounter, or superuser can unmount */
579 	if ((p->p_cred->p_ruid != pmp->pm_mounter) &&
580 	    (error = suser(p->p_ucred, &p->p_acflag)))
581 		return error;
582 
583 	if (mntflags & MNT_FORCE) {
584 		if (!msdosfsdoforce)
585 			return EINVAL;
586 		flags |= FORCECLOSE;
587 	}
588 	error = vflush(mp, NULLVP, flags);
589 	if (error)
590 		return error;
591 	pmp->pm_devvp->v_specflags &= ~SI_MOUNTEDON;
592 	error = VOP_CLOSE(pmp->pm_devvp, pmp->pm_ronly ? FREAD : FREAD | FWRITE,
593 	    NOCRED, p);
594 	vrele(pmp->pm_devvp);
595 	free((caddr_t) pmp->pm_inusemap, M_MSDOSFSFAT);
596 	free((caddr_t) pmp, M_MSDOSFSMNT);
597 	mp->mnt_data = (qaddr_t) 0;
598 	mp->mnt_flag &= ~MNT_LOCAL;
599 	return error;
600 }
601 
602 static int
603 msdosfs_root(mp, vpp)
604 	struct mount *mp;
605 	struct vnode **vpp;
606 {
607 	struct denode *ndep;
608 	struct msdosfsmount *pmp = (struct msdosfsmount *) (mp->mnt_data);
609 	int error;
610 
611 	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, NULL, &ndep);
612 #ifdef MSDOSFS_DEBUG
613 	printf("msdosfs_root(); mp %p, pmp %p, ndep %p, vp %p\n",
614 	    mp, pmp, ndep, DETOV(ndep));
615 #endif
616 	if (error == 0)
617 		*vpp = DETOV(ndep);
618 	return error;
619 }
620 
621 static int
622 msdosfs_quotactl(mp, cmds, uid, arg, p)
623 	struct mount *mp;
624 	int cmds;
625 	uid_t uid;
626 	caddr_t arg;
627 	struct proc *p;
628 {
629 	return EOPNOTSUPP;
630 }
631 
632 static int
633 msdosfs_statfs(mp, sbp, p)
634 	struct mount *mp;
635 	struct statfs *sbp;
636 	struct proc *p;
637 {
638 	struct msdosfsmount *pmp = (struct msdosfsmount *) mp->mnt_data;
639 
640 	/*
641 	 * Fill in the stat block.
642 	 */
643 	sbp->f_type = MOUNT_MSDOS;
644 	sbp->f_bsize = pmp->pm_bpcluster;
645 	sbp->f_iosize = pmp->pm_bpcluster;
646 	sbp->f_blocks = pmp->pm_nmbrofclusters;
647 	sbp->f_bfree = pmp->pm_freeclustercount;
648 	sbp->f_bavail = pmp->pm_freeclustercount;
649 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
650 	sbp->f_ffree = 0;	/* what to put in here? */
651 
652 	/*
653 	 * Copy the mounted on and mounted from names into the passed in
654 	 * stat block, if it is not the one in the mount structure.
655 	 */
656 	if (sbp != &mp->mnt_stat) {
657 		bcopy((caddr_t) mp->mnt_stat.f_mntonname,
658 		    (caddr_t) & sbp->f_mntonname[0], MNAMELEN);
659 		bcopy((caddr_t) mp->mnt_stat.f_mntfromname,
660 		    (caddr_t) & sbp->f_mntfromname[0], MNAMELEN);
661 	}
662 #if 0
663 	strncpy(&sbp->f_fstypename[0], mp->mnt_op->vfs_name, MFSNAMELEN);
664 	sbp->f_fstypename[MFSNAMELEN] = '\0';
665 #endif
666 	return 0;
667 }
668 
669 static int
670 msdosfs_sync(mp, waitfor, cred, p)
671 	struct mount *mp;
672 	int waitfor;
673 	struct ucred *cred;
674 	struct proc *p;
675 {
676 	struct vnode *vp;
677 	struct denode *dep;
678 	struct msdosfsmount *pmp;
679 	int error;
680 	int allerror = 0;
681 
682 	pmp = (struct msdosfsmount *) mp->mnt_data;
683 
684 	/*
685 	 * If we ever switch to not updating all of the fats all the time,
686 	 * this would be the place to update them from the first one.
687 	 */
688 	if (pmp->pm_fmod)
689 		if (pmp->pm_ronly)
690 			panic("msdosfs_sync: rofs mod");
691 		else {
692 			/* update fats here */
693 		}
694 
695 	/*
696 	 * Go thru in memory denodes and write them out along with
697 	 * unwritten file blocks.
698 	 */
699 loop:
700 	for (vp = mp->mnt_vnodelist.lh_first; vp;
701 	    vp = vp->v_mntvnodes.le_next) {
702 		if (vp->v_mount != mp)	/* not ours anymore	 */
703 			goto loop;
704 		if (VOP_ISLOCKED(vp))	/* file is busy		 */
705 			continue;
706 		dep = VTODE(vp);
707 		if ((dep->de_flag & (DE_MODIFIED | DE_UPDATE)) == 0 &&
708 		    vp->v_dirtyblkhd.lh_first == NULL)
709 			continue;
710 		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, p))	/* not there anymore?	 */
711 			goto loop;
712 		error = VOP_FSYNC(vp, cred, waitfor, p);
713 		if (error)
714 			allerror = error;
715 		vput(vp);	/* done with this one	 */
716 	}
717 
718 	/*
719 	 * Flush filesystem control info.
720 	 */
721 	error = VOP_FSYNC(pmp->pm_devvp, cred, waitfor, p);
722 	if (error)
723 		allerror = error;
724 	return allerror;
725 }
726 
727 static int
728 msdosfs_fhtovp(mp, fhp, nam, vpp, exflagsp, credanonp)
729 	struct mount *mp;
730 	struct fid *fhp;
731 	struct mbuf *nam;
732 	struct vnode **vpp;
733 	int *exflagsp;
734 	struct ucred **credanonp;
735 {
736 	struct msdosfsmount *pmp = (struct msdosfsmount *) mp->mnt_data;
737 	struct defid *defhp = (struct defid *) fhp;
738 	struct denode *dep;
739 	struct netcred *np;
740 	int error;
741 
742 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
743 	if (np == NULL)
744 		return EACCES;
745 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs,
746 	    NULL, &dep);
747 	if (error) {
748 		*vpp = NULLVP;
749 		return error;
750 	}
751 	*vpp = DETOV(dep);
752 	*exflagsp = np->netc_exflags;
753 	*credanonp = &np->netc_anon;
754 	return 0;
755 }
756 
757 
758 static int
759 msdosfs_vptofh(vp, fhp)
760 	struct vnode *vp;
761 	struct fid *fhp;
762 {
763 	struct denode *dep = VTODE(vp);
764 	struct defid *defhp = (struct defid *) fhp;
765 
766 	defhp->defid_len = sizeof(struct defid);
767 	defhp->defid_dirclust = dep->de_dirclust;
768 	defhp->defid_dirofs = dep->de_diroffset;
769 	/* defhp->defid_gen = ip->i_gen; */
770 	return 0;
771 }
772 
773 static int
774 msdosfs_vget(mp, ino, vpp)
775 	struct mount *mp;
776 	ino_t ino;
777 	struct vnode **vpp;
778 {
779 	return EOPNOTSUPP;
780 }
781 
782 static struct vfsops msdosfs_vfsops = {
783 	msdosfs_mount,
784 	msdosfs_start,
785 	msdosfs_unmount,
786 	msdosfs_root,
787 	msdosfs_quotactl,
788 	msdosfs_statfs,
789 	msdosfs_sync,
790 	msdosfs_vget,
791 	msdosfs_fhtovp,
792 	msdosfs_vptofh,
793 	msdosfs_init
794 };
795 
796 VFS_SET(msdosfs_vfsops, msdos, MOUNT_MSDOS, 0);
797