msdosfs_vfsops.c revision 35511
1/*	$Id: msdosfs_vfsops.c,v 1.33 1998/04/15 11:04:53 dt Exp $ */
2/*	$NetBSD: msdosfs_vfsops.c,v 1.51 1997/11/17 15:36:58 ws 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/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/fcntl.h>
61#include <sys/malloc.h>
62#include <sys/stat.h> 				/* defines ALLPERMS */
63
64#include <msdosfs/bpb.h>
65#include <msdosfs/bootsect.h>
66#include <msdosfs/direntry.h>
67#include <msdosfs/denode.h>
68#include <msdosfs/msdosfsmount.h>
69#include <msdosfs/fat.h>
70
71MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
72static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
73
74static int	update_mp __P((struct mount *mp, struct msdosfs_args *argp));
75static int	mountmsdosfs __P((struct vnode *devvp, struct mount *mp,
76				  struct proc *p, struct msdosfs_args *argp));
77static int	msdosfs_fhtovp __P((struct mount *, struct fid *,
78				    struct sockaddr *, struct vnode **, int *,
79				    struct ucred **));
80static int	msdosfs_mount __P((struct mount *, char *, caddr_t,
81				   struct nameidata *, struct proc *));
82static int	msdosfs_quotactl __P((struct mount *, int, uid_t, caddr_t,
83				      struct proc *));
84static int	msdosfs_root __P((struct mount *, struct vnode **));
85static int	msdosfs_start __P((struct mount *, int, struct proc *));
86static int	msdosfs_statfs __P((struct mount *, struct statfs *,
87				    struct proc *));
88static int	msdosfs_sync __P((struct mount *, int, struct ucred *,
89				  struct proc *));
90static int	msdosfs_unmount __P((struct mount *, int, struct proc *));
91static int	msdosfs_vget __P((struct mount *mp, ino_t ino,
92				  struct vnode **vpp));
93static int	msdosfs_vptofh __P((struct vnode *, struct fid *));
94
95static int
96update_mp(mp, argp)
97	struct mount *mp;
98	struct msdosfs_args *argp;
99{
100	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
101	int error;
102
103	pmp->pm_gid = argp->gid;
104	pmp->pm_uid = argp->uid;
105	pmp->pm_mask = argp->mask & ALLPERMS;
106	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
107	if (pmp->pm_flags & MSDOSFSMNT_U2WTABLE) {
108		bcopy(argp->u2w, pmp->pm_u2w, sizeof(pmp->pm_u2w));
109		bcopy(argp->d2u, pmp->pm_d2u, sizeof(pmp->pm_d2u));
110		bcopy(argp->u2d, pmp->pm_u2d, sizeof(pmp->pm_u2d));
111	}
112	if (pmp->pm_flags & MSDOSFSMNT_ULTABLE) {
113		bcopy(argp->ul, pmp->pm_ul, sizeof(pmp->pm_ul));
114		bcopy(argp->lu, pmp->pm_lu, sizeof(pmp->pm_lu));
115	}
116
117#ifndef __FreeBSD__
118	/*
119	 * GEMDOS knows nothing (yet) about win95
120	 */
121	if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
122		pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
123#endif
124
125	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
126		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
127	else if (!(pmp->pm_flags &
128	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
129		struct vnode *rootvp;
130
131		/*
132		 * Try to divine whether to support Win'95 long filenames
133		 */
134		if (FAT32(pmp))
135			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
136		else {
137			if ((error = msdosfs_root(mp, &rootvp)) != 0)
138				return error;
139			pmp->pm_flags |= findwin95(VTODE(rootvp))
140				? MSDOSFSMNT_LONGNAME
141					: MSDOSFSMNT_SHORTNAME;
142			vput(rootvp);
143		}
144	}
145	return 0;
146}
147
148#ifndef __FreeBSD__
149int
150msdosfs_mountroot()
151{
152	register struct mount *mp;
153	struct proc *p = curproc;	/* XXX */
154	size_t size;
155	int error;
156	struct msdosfs_args args;
157
158	if (root_device->dv_class != DV_DISK)
159		return (ENODEV);
160
161	/*
162	 * Get vnodes for swapdev and rootdev.
163	 */
164	if (bdevvp(rootdev, &rootvp))
165		panic("msdosfs_mountroot: can't setup rootvp");
166
167	mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
168	bzero((char *)mp, (u_long)sizeof(struct mount));
169	mp->mnt_op = &msdosfs_vfsops;
170	mp->mnt_flag = 0;
171	LIST_INIT(&mp->mnt_vnodelist);
172
173	args.flags = 0;
174	args.uid = 0;
175	args.gid = 0;
176	args.mask = 0777;
177
178	if ((error = mountmsdosfs(rootvp, mp, p, &args)) != 0) {
179		free(mp, M_MOUNT);
180		return (error);
181	}
182
183	if ((error = update_mp(mp, &args)) != 0) {
184		(void)msdosfs_unmount(mp, 0, p);
185		free(mp, M_MOUNT);
186		return (error);
187	}
188
189	if ((error = vfs_lock(mp)) != 0) {
190		(void)msdosfs_unmount(mp, 0, p);
191		free(mp, M_MOUNT);
192		return (error);
193	}
194
195	CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
196	mp->mnt_vnodecovered = NULLVP;
197	(void) copystr("/", mp->mnt_stat.f_mntonname, MNAMELEN - 1,
198	    &size);
199	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
200	(void) copystr(ROOTNAME, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
201	    &size);
202	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
203	(void)msdosfs_statfs(mp, &mp->mnt_stat, p);
204	vfs_unlock(mp);
205	return (0);
206}
207#endif
208
209/*
210 * mp - path - addr in user space of mount point (ie /usr or whatever)
211 * data - addr in user space of mount params including the name of the block
212 * special file to treat as a filesystem.
213 */
214static int
215msdosfs_mount(mp, path, data, ndp, p)
216	struct mount *mp;
217	char *path;
218	caddr_t data;
219	struct nameidata *ndp;
220	struct proc *p;
221{
222	struct vnode *devvp;	  /* vnode for blk device to mount */
223	struct msdosfs_args args; /* will hold data from mount request */
224	/* msdosfs specific mount control block */
225	struct msdosfsmount *pmp = NULL;
226	size_t size;
227	int error, flags;
228	mode_t accessmode;
229
230	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
231	if (error)
232		return (error);
233	if (args.magic != MSDOSFS_ARGSMAGIC)
234		args.flags = 0;
235	/*
236	 * If updating, check whether changing from read-only to
237	 * read/write; if there is no device name, that's all we do.
238	 */
239	if (mp->mnt_flag & MNT_UPDATE) {
240		pmp = VFSTOMSDOSFS(mp);
241		error = 0;
242		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
243			flags = WRITECLOSE;
244			if (mp->mnt_flag & MNT_FORCE)
245				flags |= FORCECLOSE;
246			error = vflush(mp, NULLVP, flags);
247		}
248		if (!error && (mp->mnt_flag & MNT_RELOAD))
249			/* not yet implemented */
250			error = EOPNOTSUPP;
251		if (error)
252			return (error);
253		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
254			/*
255			 * If upgrade to read-write by non-root, then verify
256			 * that user has necessary permissions on the device.
257			 */
258			if (p->p_ucred->cr_uid != 0) {
259				devvp = pmp->pm_devvp;
260				vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
261				error = VOP_ACCESS(devvp, VREAD | VWRITE,
262						   p->p_ucred, p);
263				if (error) {
264					VOP_UNLOCK(devvp, 0, p);
265					return (error);
266				}
267				VOP_UNLOCK(devvp, 0, p);
268			}
269			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
270		}
271		if (args.fspec == 0) {
272#ifdef	__notyet__		/* doesn't work correctly with current mountd	XXX */
273			if (args.flags & MSDOSFSMNT_MNTOPT) {
274				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
275				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
276				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
277					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
278			}
279#endif
280			/*
281			 * Process export requests.
282			 */
283			return (vfs_export(mp, &pmp->pm_export, &args.export));
284		}
285	}
286	/*
287	 * Not an update, or updating the name: look up the name
288	 * and verify that it refers to a sensible block device.
289	 */
290	NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, p);
291	error = namei(ndp);
292	if (error)
293		return (error);
294	devvp = ndp->ni_vp;
295
296	if (devvp->v_type != VBLK) {
297		vrele(devvp);
298		return (ENOTBLK);
299	}
300	if (major(devvp->v_rdev) >= nblkdev) {
301		vrele(devvp);
302		return (ENXIO);
303	}
304	/*
305	 * If mount by non-root, then verify that user has necessary
306	 * permissions on the device.
307	 */
308	if (p->p_ucred->cr_uid != 0) {
309		accessmode = VREAD;
310		if ((mp->mnt_flag & MNT_RDONLY) == 0)
311			accessmode |= VWRITE;
312		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
313		error = VOP_ACCESS(devvp, accessmode, p->p_ucred, p);
314		if (error) {
315			vput(devvp);
316			return (error);
317		}
318		VOP_UNLOCK(devvp, 0, p);
319	}
320	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
321		error = mountmsdosfs(devvp, mp, p, &args);
322#ifdef MSDOSFS_DEBUG		/* only needed for the printf below */
323		pmp = VFSTOMSDOSFS(mp);
324#endif
325	} else {
326		if (devvp != pmp->pm_devvp)
327			error = EINVAL;	/* XXX needs translation */
328		else
329			vrele(devvp);
330	}
331	if (error) {
332		vrele(devvp);
333		return (error);
334	}
335
336	error = update_mp(mp, &args);
337	if (error) {
338		msdosfs_unmount(mp, MNT_FORCE, p);
339		return error;
340	}
341
342	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
343	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
344	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
345	    &size);
346	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
347	(void) msdosfs_statfs(mp, &mp->mnt_stat, p);
348#ifdef MSDOSFS_DEBUG
349	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
350#endif
351	return (0);
352}
353
354static int
355mountmsdosfs(devvp, mp, p, argp)
356	struct vnode *devvp;
357	struct mount *mp;
358	struct proc *p;
359	struct msdosfs_args *argp;
360{
361	struct msdosfsmount *pmp;
362	struct buf *bp;
363	dev_t dev = devvp->v_rdev;
364#ifndef __FreeBSD__
365	struct partinfo dpart;
366#endif
367	union bootsector *bsp;
368	struct byte_bpb33 *b33;
369	struct byte_bpb50 *b50;
370	struct byte_bpb710 *b710;
371	u_int8_t SecPerClust;
372	int	ronly, error;
373	int	bsize = 0, dtype = 0, tmp;
374
375	/*
376	 * Disallow multiple mounts of the same device.
377	 * Disallow mounting of a device that is currently in use
378	 * (except for root, which might share swap device for miniroot).
379	 * Flush out any old buffers remaining from a previous use.
380	 */
381	error = vfs_mountedon(devvp);
382	if (error)
383		return (error);
384	if (vcount(devvp) > 1 && devvp != rootvp)
385		return (EBUSY);
386	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
387	error = vinvalbuf(devvp, V_SAVE, p->p_ucred, p, 0, 0);
388	VOP_UNLOCK(devvp, 0, p);
389	if (error)
390		return (error);
391
392	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
393	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p);
394	if (error)
395		return (error);
396
397	bp  = NULL; /* both used in error_exit */
398	pmp = NULL;
399
400#ifndef __FreeBSD__
401	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
402		/*
403	 	 * We need the disklabel to calculate the size of a FAT entry
404		 * later on. Also make sure the partition contains a filesystem
405		 * of type FS_MSDOS. This doesn't work for floppies, so we have
406		 * to check for them too.
407	 	 *
408	 	 * At least some parts of the msdos fs driver seem to assume
409		 * that the size of a disk block will always be 512 bytes.
410		 * Let's check it...
411		 */
412		error = VOP_IOCTL(devvp, DIOCGPART, (caddr_t)&dpart,
413				  FREAD, NOCRED, p);
414		if (error)
415			goto error_exit;
416		tmp   = dpart.part->p_fstype;
417		dtype = dpart.disklab->d_type;
418		bsize = dpart.disklab->d_secsize;
419		if (bsize != 512 || (dtype!=DTYPE_FLOPPY && tmp!=FS_MSDOS)) {
420			error = EINVAL;
421			goto error_exit;
422		}
423	}
424#endif
425
426	/*
427	 * Read the boot sector of the filesystem, and then check the
428	 * boot signature.  If not a dos boot sector then error out.
429	 */
430#ifdef	PC98
431	error = bread(devvp, 0, 1024, NOCRED, &bp);
432#else
433	error = bread(devvp, 0, 512, NOCRED, &bp);
434#endif
435	if (error)
436		goto error_exit;
437	bp->b_flags |= B_AGE;
438	bsp = (union bootsector *)bp->b_data;
439	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
440	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
441	b710 = (struct byte_bpb710 *)bsp->bs710.bsPBP;
442
443#ifndef __FreeBSD__
444	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
445#endif
446#ifdef PC98
447		if ((bsp->bs50.bsBootSectSig0 != BOOTSIG0
448		    || bsp->bs50.bsBootSectSig1 != BOOTSIG1)
449		    && (bsp->bs50.bsBootSectSig0 != 0       /* PC98 DOS 3.3x */
450		    || bsp->bs50.bsBootSectSig1 != 0)
451		    && (bsp->bs50.bsBootSectSig0 != 0x90    /* PC98 DOS 5.0  */
452		    || bsp->bs50.bsBootSectSig1 != 0x3d)
453		    && (bsp->bs50.bsBootSectSig0 != 0x46    /* PC98 DOS 3.3B */
454		    || bsp->bs50.bsBootSectSig1 != 0xfa)) {
455#else
456		if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
457		    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
458#endif
459			error = EINVAL;
460			printf("mountmsdosfs(): bad signature\n");
461			goto error_exit;
462		}
463#ifndef __FreeBSD__
464	}
465#endif
466
467	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
468	bzero((caddr_t)pmp, sizeof *pmp);
469	pmp->pm_mountp = mp;
470
471	/*
472	 * Compute several useful quantities from the bpb in the
473	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
474	 * the fields that are different between dos 5 and dos 3.3.
475	 */
476	SecPerClust = b50->bpbSecPerClust;
477	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
478	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
479	pmp->pm_FATs = b50->bpbFATs;
480	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
481	pmp->pm_Sectors = getushort(b50->bpbSectors);
482	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
483	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
484	pmp->pm_Heads = getushort(b50->bpbHeads);
485	pmp->pm_Media = b50->bpbMedia;
486
487#ifndef __FreeBSD__
488	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
489#endif
490		/* XXX - We should probably check more values here */
491		if (!pmp->pm_BytesPerSec || !SecPerClust
492			|| !pmp->pm_Heads || pmp->pm_Heads > 255
493#ifdef PC98
494	    		|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 255) {
495#else
496			|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 63) {
497#endif
498			error = EINVAL;
499			printf("mountmsdosfs(): bad bpb\n");
500			goto error_exit;
501		}
502#ifndef __FreeBSD__
503	}
504#endif
505
506	if (pmp->pm_Sectors == 0) {
507		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
508		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
509	} else {
510		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
511		pmp->pm_HugeSectors = pmp->pm_Sectors;
512	}
513	if (pmp->pm_HugeSectors > 0xffffffff /
514	    (pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) {
515		/*
516		 * We cannot deal currently with this size of disk
517		 * due to fileid limitations (see msdosfs_getattr and
518		 * msdosfs_readdir)
519		 */
520		error = EINVAL;
521		printf("mountmsdosfs(): disk too big, sorry\n");
522		goto error_exit;
523	}
524
525	if (pmp->pm_RootDirEnts == 0) {
526		if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
527		    || bsp->bs710.bsBootSectSig3 != BOOTSIG3
528		    || pmp->pm_Sectors
529		    || pmp->pm_FATsecs
530		    || getushort(b710->bpbFSVers)) {
531			error = EINVAL;
532			printf("mountmsdosfs(): bad FAT32 filesystem\n");
533			goto error_exit;
534		}
535		pmp->pm_fatmask = FAT32_MASK;
536		pmp->pm_fatmult = 4;
537		pmp->pm_fatdiv = 1;
538		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
539		if (getushort(b710->bpbExtFlags) & FATMIRROR)
540			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
541		else
542			pmp->pm_flags |= MSDOSFS_FATMIRROR;
543	} else
544		pmp->pm_flags |= MSDOSFS_FATMIRROR;
545
546#ifndef __FreeBSD__
547	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
548		if (FAT32(pmp)) {
549			/*
550			 * GEMDOS doesn't know fat32.
551			 */
552			error = EINVAL;
553			goto error_exit;
554		}
555
556		/*
557		 * Check a few values (could do some more):
558		 * - logical sector size: power of 2, >= block size
559		 * - sectors per cluster: power of 2, >= 1
560		 * - number of sectors:   >= 1, <= size of partition
561		 */
562		if ( (SecPerClust == 0)
563		  || (SecPerClust & (SecPerClust - 1))
564		  || (pmp->pm_BytesPerSec < bsize)
565		  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
566		  || (pmp->pm_HugeSectors == 0)
567		  || (pmp->pm_HugeSectors * (pmp->pm_BytesPerSec / bsize)
568							> dpart.part->p_size)
569		   ) {
570			error = EINVAL;
571			goto error_exit;
572		}
573		/*
574		 * XXX - Many parts of the msdos fs driver seem to assume that
575		 * the number of bytes per logical sector (BytesPerSec) will
576		 * always be the same as the number of bytes per disk block
577		 * Let's pretend it is.
578		 */
579		tmp = pmp->pm_BytesPerSec / bsize;
580		pmp->pm_BytesPerSec  = bsize;
581		pmp->pm_HugeSectors *= tmp;
582		pmp->pm_HiddenSects *= tmp;
583		pmp->pm_ResSectors  *= tmp;
584		pmp->pm_Sectors     *= tmp;
585		pmp->pm_FATsecs     *= tmp;
586		SecPerClust         *= tmp;
587	}
588#endif
589	pmp->pm_fatblk = pmp->pm_ResSectors;
590	if (FAT32(pmp)) {
591		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
592		pmp->pm_firstcluster = pmp->pm_fatblk
593			+ (pmp->pm_FATs * pmp->pm_FATsecs);
594		pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
595	} else {
596		pmp->pm_rootdirblk = pmp->pm_fatblk +
597			(pmp->pm_FATs * pmp->pm_FATsecs);
598		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
599				       + pmp->pm_BytesPerSec - 1)
600			/ pmp->pm_BytesPerSec;/* in sectors */
601		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
602	}
603
604	pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
605	    SecPerClust;
606	pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
607	pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
608
609#ifndef __FreeBSD__
610	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
611		if ((pmp->pm_nmbrofclusters <= (0xff0 - 2))
612		      && ((dtype == DTYPE_FLOPPY) || ((dtype == DTYPE_VNODE)
613		      && ((pmp->pm_Heads == 1) || (pmp->pm_Heads == 2))))
614		    ) {
615			pmp->pm_fatmask = FAT12_MASK;
616			pmp->pm_fatmult = 3;
617			pmp->pm_fatdiv = 2;
618		} else {
619			pmp->pm_fatmask = FAT16_MASK;
620			pmp->pm_fatmult = 2;
621			pmp->pm_fatdiv = 1;
622		}
623	} else
624#endif
625	if (pmp->pm_fatmask == 0) {
626		if (pmp->pm_maxcluster
627		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
628			/*
629			 * This will usually be a floppy disk. This size makes
630			 * sure that one fat entry will not be split across
631			 * multiple blocks.
632			 */
633			pmp->pm_fatmask = FAT12_MASK;
634			pmp->pm_fatmult = 3;
635			pmp->pm_fatdiv = 2;
636		} else {
637			pmp->pm_fatmask = FAT16_MASK;
638			pmp->pm_fatmult = 2;
639			pmp->pm_fatdiv = 1;
640		}
641	}
642	if (FAT12(pmp))
643		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
644	else
645		pmp->pm_fatblocksize = DFLTBSIZE;
646
647	pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
648	pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
649
650	/*
651	 * Compute mask and shift value for isolating cluster relative byte
652	 * offsets and cluster numbers from a file offset.
653	 */
654	pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
655	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
656	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
657
658	/*
659	 * Check for valid cluster size
660	 * must be a power of 2
661	 */
662	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
663		error = EINVAL;
664		goto error_exit;
665	}
666
667	/*
668	 * Release the bootsector buffer.
669	 */
670	brelse(bp);
671	bp = NULL;
672
673	/*
674	 * Check FSInfo.
675	 */
676	if (pmp->pm_fsinfo) {
677		struct fsinfo *fp;
678
679		if ((error = bread(devvp, pmp->pm_fsinfo, 1024, NOCRED, &bp)) != 0)
680			goto error_exit;
681		fp = (struct fsinfo *)bp->b_data;
682		if (!bcmp(fp->fsisig1, "RRaA", 4)
683		    && !bcmp(fp->fsisig2, "rrAa", 4)
684		    && !bcmp(fp->fsisig3, "\0\0\125\252", 4)
685		    && !bcmp(fp->fsisig4, "\0\0\125\252", 4))
686			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
687		else
688			pmp->pm_fsinfo = 0;
689		brelse(bp);
690		bp = NULL;
691	}
692
693	/*
694	 * Check and validate (or perhaps invalidate?) the fsinfo structure?		XXX
695	 */
696
697	/*
698	 * Allocate memory for the bitmap of allocated clusters, and then
699	 * fill it in.
700	 */
701	pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
702				   / N_INUSEBITS)
703				  * sizeof(*pmp->pm_inusemap),
704				  M_MSDOSFSFAT, M_WAITOK);
705
706	/*
707	 * fillinusemap() needs pm_devvp.
708	 */
709	pmp->pm_dev = dev;
710	pmp->pm_devvp = devvp;
711
712	/*
713	 * Have the inuse map filled in.
714	 */
715	if ((error = fillinusemap(pmp)) != 0)
716		goto error_exit;
717
718	/*
719	 * If they want fat updates to be synchronous then let them suffer
720	 * the performance degradation in exchange for the on disk copy of
721	 * the fat being correct just about all the time.  I suppose this
722	 * would be a good thing to turn on if the kernel is still flakey.
723	 */
724	if (mp->mnt_flag & MNT_SYNCHRONOUS)
725		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
726
727	/*
728	 * Finish up.
729	 */
730	if (ronly)
731		pmp->pm_flags |= MSDOSFSMNT_RONLY;
732	else
733		pmp->pm_fmod = 1;
734	mp->mnt_data = (qaddr_t) pmp;
735	mp->mnt_stat.f_fsid.val[0] = (long)dev;
736	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
737	mp->mnt_flag |= MNT_LOCAL;
738	devvp->v_specmountpoint = mp;
739
740	return 0;
741
742error_exit:
743	if (bp)
744		brelse(bp);
745	(void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE, NOCRED, p);
746	if (pmp) {
747		if (pmp->pm_inusemap)
748			free(pmp->pm_inusemap, M_MSDOSFSFAT);
749		free(pmp, M_MSDOSFSMNT);
750		mp->mnt_data = (qaddr_t)0;
751	}
752	return (error);
753}
754
755static int
756msdosfs_start(mp, flags, p)
757	struct mount *mp;
758	int flags;
759	struct proc *p;
760{
761
762	return (0);
763}
764
765/*
766 * Unmount the filesystem described by mp.
767 */
768static int
769msdosfs_unmount(mp, mntflags, p)
770	struct mount *mp;
771	int mntflags;
772	struct proc *p;
773{
774	struct msdosfsmount *pmp;
775	int error, flags;
776
777	flags = 0;
778	if (mntflags & MNT_FORCE)
779		flags |= FORCECLOSE;
780	error = vflush(mp, NULLVP, flags);
781	if (error)
782		return error;
783	pmp = VFSTOMSDOSFS(mp);
784	pmp->pm_devvp->v_specmountpoint = NULL;
785#ifdef MSDOSFS_DEBUG
786	{
787		struct vnode *vp = pmp->pm_devvp;
788
789		printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
790		printf("flag %08lx, usecount %d, writecount %d, holdcnt %ld\n",
791		    vp->v_flag, vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
792		printf("lastr %d, id %lu, mount %p, op %p\n",
793		    vp->v_lastr, vp->v_id, vp->v_mount, vp->v_op);
794		printf("freef %p, freeb %p, mount %p\n",
795		    vp->v_freelist.tqe_next, vp->v_freelist.tqe_prev,
796		    vp->v_mount);
797		printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n",
798		    vp->v_cleanblkhd.lh_first,
799		    vp->v_dirtyblkhd.lh_first,
800		    vp->v_numoutput, vp->v_type);
801		printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
802		    vp->v_socket, vp->v_tag,
803		    ((u_int *)vp->v_data)[0],
804		    ((u_int *)vp->v_data)[1]);
805	}
806#endif
807	error = VOP_CLOSE(pmp->pm_devvp,
808		    (pmp->pm_flags&MSDOSFSMNT_RONLY) ? FREAD : FREAD | FWRITE,
809		    NOCRED, p);
810	vrele(pmp->pm_devvp);
811	free(pmp->pm_inusemap, M_MSDOSFSFAT);
812	free(pmp, M_MSDOSFSMNT);
813	mp->mnt_data = (qaddr_t)0;
814	mp->mnt_flag &= ~MNT_LOCAL;
815	return (error);
816}
817
818static int
819msdosfs_root(mp, vpp)
820	struct mount *mp;
821	struct vnode **vpp;
822{
823	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
824	struct denode *ndep;
825	int error;
826
827#ifdef MSDOSFS_DEBUG
828	printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
829#endif
830	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
831	if (error)
832		return (error);
833	*vpp = DETOV(ndep);
834	return (0);
835}
836
837static int
838msdosfs_quotactl(mp, cmds, uid, arg, p)
839	struct mount *mp;
840	int cmds;
841	uid_t uid;
842	caddr_t arg;
843	struct proc *p;
844{
845	return EOPNOTSUPP;
846}
847
848static int
849msdosfs_statfs(mp, sbp, p)
850	struct mount *mp;
851	struct statfs *sbp;
852	struct proc *p;
853{
854	struct msdosfsmount *pmp;
855
856	pmp = VFSTOMSDOSFS(mp);
857	sbp->f_bsize = pmp->pm_bpcluster;
858	sbp->f_iosize = pmp->pm_bpcluster;
859	sbp->f_blocks = pmp->pm_nmbrofclusters;
860	sbp->f_bfree = pmp->pm_freeclustercount;
861	sbp->f_bavail = pmp->pm_freeclustercount;
862	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
863	sbp->f_ffree = 0;	/* what to put in here? */
864	if (sbp != &mp->mnt_stat) {
865		sbp->f_type = mp->mnt_vfc->vfc_typenum;
866		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
867		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
868	}
869	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
870	return (0);
871}
872
873static int
874msdosfs_sync(mp, waitfor, cred, p)
875	struct mount *mp;
876	int waitfor;
877	struct ucred *cred;
878	struct proc *p;
879{
880	struct vnode *vp, *nvp;
881	struct denode *dep;
882	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
883	int error, allerror = 0;
884
885	/*
886	 * If we ever switch to not updating all of the fats all the time,
887	 * this would be the place to update them from the first one.
888	 */
889	if (pmp->pm_fmod != 0)
890		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
891			panic("msdosfs_sync: rofs mod");
892		else {
893			/* update fats here */
894		}
895	/*
896	 * Write back each (modified) denode.
897	 */
898	simple_lock(&mntvnode_slock);
899loop:
900	for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
901		/*
902		 * If the vnode that we are about to sync is no longer
903		 * associated with this mount point, start over.
904		 */
905		if (vp->v_mount != mp)
906			goto loop;
907
908		simple_lock(&vp->v_interlock);
909		nvp = vp->v_mntvnodes.le_next;
910		dep = VTODE(vp);
911		if (vp->v_type == VNON ||
912		    (dep->de_flag &
913		    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
914		    (vp->v_dirtyblkhd.lh_first == NULL ||
915		    waitfor == MNT_LAZY)) {
916			simple_unlock(&vp->v_interlock);
917			continue;
918		}
919		simple_unlock(&mntvnode_slock);
920		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, p);
921		if (error) {
922			simple_lock(&mntvnode_slock);
923			if (error == ENOENT)
924				goto loop;
925			continue;
926		}
927		error = VOP_FSYNC(vp, cred, waitfor, p);
928		if (error)
929			allerror = error;
930		VOP_UNLOCK(vp, 0, p);
931		vrele(vp);
932		simple_lock(&mntvnode_slock);
933	}
934	simple_unlock(&mntvnode_slock);
935
936	/*
937	 * Flush filesystem control info.
938	 */
939	if (waitfor != MNT_LAZY) {
940		vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY, p);
941		error = VOP_FSYNC(pmp->pm_devvp, cred, waitfor, p);
942		if (error)
943			allerror = error;
944		VOP_UNLOCK(pmp->pm_devvp, 0, p);
945	}
946	return (allerror);
947}
948
949static int
950msdosfs_fhtovp(mp, fhp, nam, vpp, exflagsp, credanonp)
951	struct mount *mp;
952	struct fid *fhp;
953	struct sockaddr *nam;
954	struct vnode **vpp;
955	int *exflagsp;
956	struct ucred **credanonp;
957{
958	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
959	struct defid *defhp = (struct defid *) fhp;
960	struct denode *dep;
961	struct netcred *np;
962	int error;
963
964	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
965	if (np == NULL)
966		return (EACCES);
967	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
968	if (error) {
969		*vpp = NULLVP;
970		return (error);
971	}
972	*vpp = DETOV(dep);
973	*exflagsp = np->netc_exflags;
974	*credanonp = &np->netc_anon;
975	return (0);
976}
977
978static int
979msdosfs_vptofh(vp, fhp)
980	struct vnode *vp;
981	struct fid *fhp;
982{
983	struct denode *dep;
984	struct defid *defhp;
985
986	dep = VTODE(vp);
987	defhp = (struct defid *)fhp;
988	defhp->defid_len = sizeof(struct defid);
989	defhp->defid_dirclust = dep->de_dirclust;
990	defhp->defid_dirofs = dep->de_diroffset;
991	/* defhp->defid_gen = dep->de_gen; */
992	return (0);
993}
994
995static int
996msdosfs_vget(mp, ino, vpp)
997	struct mount *mp;
998	ino_t ino;
999	struct vnode **vpp;
1000{
1001	return EOPNOTSUPP;
1002}
1003
1004static struct vfsops msdosfs_vfsops = {
1005	msdosfs_mount,
1006	msdosfs_start,
1007	msdosfs_unmount,
1008	msdosfs_root,
1009	msdosfs_quotactl,
1010	msdosfs_statfs,
1011	msdosfs_sync,
1012	msdosfs_vget,
1013	vfs_vrele,
1014	msdosfs_fhtovp,
1015	msdosfs_vptofh,
1016	msdosfs_init
1017};
1018
1019VFS_SET(msdosfs_vfsops, msdos, MOUNT_MSDOS, 0);
1020