xref: /netbsd-src/sys/fs/msdosfs/msdosfs_vfsops.c (revision b8c616269f5ebf18ab2e35cb8099d683130a177c)
1 /*	$NetBSD: msdosfs_vfsops.c,v 1.2 2003/02/01 06:23:41 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
5  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
6  * All rights reserved.
7  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *	This product includes software developed by TooLs GmbH.
20  * 4. The name of TooLs GmbH may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
27  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
29  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
30  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
31  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
32  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 /*
35  * Written by Paul Popelka (paulp@uts.amdahl.com)
36  *
37  * You can do anything you want with this software, just don't say you wrote
38  * it, and don't remove this notice.
39  *
40  * This software is provided "as is".
41  *
42  * The author supplies this software to be publicly redistributed on the
43  * understanding that the author is not responsible for the correct
44  * functioning of this software in any circumstances and is not liable for
45  * any damages caused by this software.
46  *
47  * October 1992
48  */
49 
50 #include <sys/cdefs.h>
51 __KERNEL_RCSID(0, "$NetBSD: msdosfs_vfsops.c,v 1.2 2003/02/01 06:23:41 thorpej Exp $");
52 
53 #if defined(_KERNEL_OPT)
54 #include "opt_quota.h"
55 #include "opt_compat_netbsd.h"
56 #endif
57 
58 #include <sys/param.h>
59 #include <sys/systm.h>
60 #include <sys/namei.h>
61 #include <sys/proc.h>
62 #include <sys/kernel.h>
63 #include <sys/vnode.h>
64 #include <miscfs/specfs/specdev.h> /* XXX */	/* defines v_rdev */
65 #include <sys/mount.h>
66 #include <sys/buf.h>
67 #include <sys/file.h>
68 #include <sys/device.h>
69 #include <sys/disklabel.h>
70 #include <sys/ioctl.h>
71 #include <sys/malloc.h>
72 #include <sys/dirent.h>
73 #include <sys/stat.h>
74 #include <sys/conf.h>
75 
76 #include <fs/msdosfs/bpb.h>
77 #include <fs/msdosfs/bootsect.h>
78 #include <fs/msdosfs/direntry.h>
79 #include <fs/msdosfs/denode.h>
80 #include <fs/msdosfs/msdosfsmount.h>
81 #include <fs/msdosfs/fat.h>
82 
83 int msdosfs_mountroot __P((void));
84 int msdosfs_mount __P((struct mount *, const char *, void *,
85     struct nameidata *, struct proc *));
86 int msdosfs_start __P((struct mount *, int, struct proc *));
87 int msdosfs_unmount __P((struct mount *, int, struct proc *));
88 int msdosfs_root __P((struct mount *, struct vnode **));
89 int msdosfs_quotactl __P((struct mount *, int, uid_t, caddr_t, struct proc *));
90 int msdosfs_statfs __P((struct mount *, struct statfs *, struct proc *));
91 int msdosfs_sync __P((struct mount *, int, struct ucred *, struct proc *));
92 int msdosfs_vget __P((struct mount *, ino_t, struct vnode **));
93 int msdosfs_fhtovp __P((struct mount *, struct fid *, struct vnode **));
94 int msdosfs_checkexp __P((struct mount *, struct mbuf *, int *,
95     struct ucred **));
96 int msdosfs_vptofh __P((struct vnode *, struct fid *));
97 int msdosfs_sysctl __P((int *, u_int, void *, size_t *, void *, size_t,
98 			struct proc *));
99 
100 int msdosfs_mountfs __P((struct vnode *, struct mount *, struct proc *,
101     struct msdosfs_args *));
102 
103 static int update_mp __P((struct mount *, struct msdosfs_args *));
104 
105 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOS FS mount structure");
106 MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS fat", "MSDOS FS fat table");
107 
108 #define ROOTNAME "root_device"
109 
110 extern const struct vnodeopv_desc msdosfs_vnodeop_opv_desc;
111 
112 const struct vnodeopv_desc * const msdosfs_vnodeopv_descs[] = {
113 	&msdosfs_vnodeop_opv_desc,
114 	NULL,
115 };
116 
117 struct vfsops msdosfs_vfsops = {
118 	MOUNT_MSDOS,
119 	msdosfs_mount,
120 	msdosfs_start,
121 	msdosfs_unmount,
122 	msdosfs_root,
123 	msdosfs_quotactl,
124 	msdosfs_statfs,
125 	msdosfs_sync,
126 	msdosfs_vget,
127 	msdosfs_fhtovp,
128 	msdosfs_vptofh,
129 	msdosfs_init,
130 	msdosfs_reinit,
131 	msdosfs_done,
132 	msdosfs_sysctl,
133 	msdosfs_mountroot,
134 	msdosfs_checkexp,
135 	msdosfs_vnodeopv_descs,
136 };
137 
138 static int
139 update_mp(mp, argp)
140 	struct mount *mp;
141 	struct msdosfs_args *argp;
142 {
143 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
144 	int error;
145 
146 	pmp->pm_gid = argp->gid;
147 	pmp->pm_uid = argp->uid;
148 	pmp->pm_mask = argp->mask & ALLPERMS;
149 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
150 
151 	/*
152 	 * GEMDOS knows nothing (yet) about win95
153 	 */
154 	if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
155 		pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
156 
157 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
158 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
159 	else if (!(pmp->pm_flags &
160 	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
161 		struct vnode *rootvp;
162 
163 		/*
164 		 * Try to divine whether to support Win'95 long filenames
165 		 */
166 		if (FAT32(pmp))
167 			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
168 		else {
169 			if ((error = msdosfs_root(mp, &rootvp)) != 0)
170 				return error;
171 			pmp->pm_flags |= findwin95(VTODE(rootvp))
172 				? MSDOSFSMNT_LONGNAME
173 					: MSDOSFSMNT_SHORTNAME;
174 			vput(rootvp);
175 		}
176 	}
177 	return 0;
178 }
179 
180 int
181 msdosfs_mountroot()
182 {
183 	struct mount *mp;
184 	struct proc *p = curproc;	/* XXX */
185 	int error;
186 	struct msdosfs_args args;
187 
188 	if (root_device->dv_class != DV_DISK)
189 		return (ENODEV);
190 
191 	/*
192 	 * Get vnodes for swapdev and rootdev.
193 	 */
194 	if (bdevvp(rootdev, &rootvp))
195 		panic("msdosfs_mountroot: can't setup rootvp");
196 
197 	if ((error = vfs_rootmountalloc(MOUNT_MSDOS, "root_device", &mp))) {
198 		vrele(rootvp);
199 		return (error);
200 	}
201 
202 	args.flags = 0;
203 	args.uid = 0;
204 	args.gid = 0;
205 	args.mask = 0777;
206 
207 	if ((error = msdosfs_mountfs(rootvp, mp, p, &args)) != 0) {
208 		mp->mnt_op->vfs_refcount--;
209 		vfs_unbusy(mp);
210 		free(mp, M_MOUNT);
211 		vrele(rootvp);
212 		return (error);
213 	}
214 
215 	if ((error = update_mp(mp, &args)) != 0) {
216 		(void)msdosfs_unmount(mp, 0, p);
217 		vfs_unbusy(mp);
218 		free(mp, M_MOUNT);
219 		vrele(rootvp);
220 		return (error);
221 	}
222 
223 	simple_lock(&mountlist_slock);
224 	CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
225 	simple_unlock(&mountlist_slock);
226 	(void)msdosfs_statfs(mp, &mp->mnt_stat, p);
227 	vfs_unbusy(mp);
228 	return (0);
229 }
230 
231 /*
232  * mp - path - addr in user space of mount point (ie /usr or whatever)
233  * data - addr in user space of mount params including the name of the block
234  * special file to treat as a filesystem.
235  */
236 int
237 msdosfs_mount(mp, path, data, ndp, p)
238 	struct mount *mp;
239 	const char *path;
240 	void *data;
241 	struct nameidata *ndp;
242 	struct proc *p;
243 {
244 	struct vnode *devvp;	  /* vnode for blk device to mount */
245 	struct msdosfs_args args; /* will hold data from mount request */
246 	/* msdosfs specific mount control block */
247 	struct msdosfsmount *pmp = NULL;
248 	size_t size;
249 	int error, flags;
250 	mode_t accessmode;
251 
252 	if (mp->mnt_flag & MNT_GETARGS) {
253 		pmp = VFSTOMSDOSFS(mp);
254 		if (pmp == NULL)
255 			return EIO;
256 		args.fspec = NULL;
257 		args.uid = pmp->pm_uid;
258 		args.gid = pmp->pm_gid;
259 		args.mask = pmp->pm_mask;
260 		args.flags = pmp->pm_flags;
261 		vfs_showexport(mp, &args.export, &pmp->pm_export);
262 		return copyout(&args, data, sizeof(args));
263 	}
264 	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
265 	if (error)
266 		return (error);
267 	/*
268 	 * If updating, check whether changing from read-only to
269 	 * read/write; if there is no device name, that's all we do.
270 	 */
271 	if (mp->mnt_flag & MNT_UPDATE) {
272 		pmp = VFSTOMSDOSFS(mp);
273 		error = 0;
274 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
275 			flags = WRITECLOSE;
276 			if (mp->mnt_flag & MNT_FORCE)
277 				flags |= FORCECLOSE;
278 			error = vflush(mp, NULLVP, flags);
279 		}
280 		if (!error && (mp->mnt_flag & MNT_RELOAD))
281 			/* not yet implemented */
282 			error = EOPNOTSUPP;
283 		if (error)
284 			return (error);
285 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_WANTRDWR)) {
286 			/*
287 			 * If upgrade to read-write by non-root, then verify
288 			 * that user has necessary permissions on the device.
289 			 */
290 			if (p->p_ucred->cr_uid != 0) {
291 				devvp = pmp->pm_devvp;
292 				vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
293 				error = VOP_ACCESS(devvp, VREAD | VWRITE,
294 						   p->p_ucred, p);
295 				VOP_UNLOCK(devvp, 0);
296 				if (error)
297 					return (error);
298 			}
299 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
300 		}
301 		if (args.fspec == 0) {
302 #ifdef	__notyet__		/* doesn't work correctly with current mountd	XXX */
303 			if (args.flags & MSDOSFSMNT_MNTOPT) {
304 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
305 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
306 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
307 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
308 			}
309 #endif
310 			/*
311 			 * Process export requests.
312 			 */
313 			return (vfs_export(mp, &pmp->pm_export, &args.export));
314 		}
315 	}
316 	/*
317 	 * Not an update, or updating the name: look up the name
318 	 * and verify that it refers to a sensible block device.
319 	 */
320 	NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, p);
321 	if ((error = namei(ndp)) != 0)
322 		return (error);
323 	devvp = ndp->ni_vp;
324 
325 	if (devvp->v_type != VBLK) {
326 		vrele(devvp);
327 		return (ENOTBLK);
328 	}
329 	if (bdevsw_lookup(devvp->v_rdev) == NULL) {
330 		vrele(devvp);
331 		return (ENXIO);
332 	}
333 	/*
334 	 * If mount by non-root, then verify that user has necessary
335 	 * permissions on the device.
336 	 */
337 	if (p->p_ucred->cr_uid != 0) {
338 		accessmode = VREAD;
339 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
340 			accessmode |= VWRITE;
341 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
342 		error = VOP_ACCESS(devvp, accessmode, p->p_ucred, p);
343 		VOP_UNLOCK(devvp, 0);
344 		if (error) {
345 			vrele(devvp);
346 			return (error);
347 		}
348 	}
349 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
350 		error = msdosfs_mountfs(devvp, mp, p, &args);
351 #ifdef MSDOSFS_DEBUG		/* only needed for the printf below */
352 		pmp = VFSTOMSDOSFS(mp);
353 #endif
354 	} else {
355 		if (devvp != pmp->pm_devvp)
356 			error = EINVAL;	/* needs translation */
357 		else
358 			vrele(devvp);
359 	}
360 	if (error) {
361 		vrele(devvp);
362 		return (error);
363 	}
364 
365 	if ((error = update_mp(mp, &args)) != 0) {
366 		msdosfs_unmount(mp, MNT_FORCE, p);
367 		return error;
368 	}
369 
370 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
371 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
372 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
373 	    &size);
374 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
375 #ifdef MSDOSFS_DEBUG
376 	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
377 #endif
378 	return (0);
379 }
380 
381 int
382 msdosfs_mountfs(devvp, mp, p, argp)
383 	struct vnode *devvp;
384 	struct mount *mp;
385 	struct proc *p;
386 	struct msdosfs_args *argp;
387 {
388 	struct msdosfsmount *pmp;
389 	struct buf *bp;
390 	dev_t dev = devvp->v_rdev;
391 	struct partinfo dpart;
392 	union bootsector *bsp;
393 	struct byte_bpb33 *b33;
394 	struct byte_bpb50 *b50;
395 	struct byte_bpb710 *b710;
396 	u_int8_t SecPerClust;
397 	int	ronly, error;
398 	int	bsize = 0, dtype = 0, tmp;
399 	u_long	dirsperblk;
400 
401 	/*
402 	 * Disallow multiple mounts of the same device.
403 	 * Disallow mounting of a device that is currently in use
404 	 * (except for root, which might share swap device for miniroot).
405 	 * Flush out any old buffers remaining from a previous use.
406 	 */
407 	if ((error = vfs_mountedon(devvp)) != 0)
408 		return (error);
409 	if (vcount(devvp) > 1 && devvp != rootvp)
410 		return (EBUSY);
411 	if ((error = vinvalbuf(devvp, V_SAVE, p->p_ucred, p, 0, 0)) != 0)
412 		return (error);
413 
414 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
415 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p);
416 	if (error)
417 		return (error);
418 
419 	bp  = NULL; /* both used in error_exit */
420 	pmp = NULL;
421 
422 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
423 		/*
424 	 	 * We need the disklabel to calculate the size of a FAT entry
425 		 * later on. Also make sure the partition contains a filesystem
426 		 * of type FS_MSDOS. This doesn't work for floppies, so we have
427 		 * to check for them too.
428 	 	 *
429 	 	 * At least some parts of the msdos fs driver seem to assume
430 		 * that the size of a disk block will always be 512 bytes.
431 		 * Let's check it...
432 		 */
433 		error = VOP_IOCTL(devvp, DIOCGPART, (caddr_t)&dpart,
434 				  FREAD, NOCRED, p);
435 		if (error)
436 			goto error_exit;
437 		tmp   = dpart.part->p_fstype;
438 		dtype = dpart.disklab->d_type;
439 		bsize = dpart.disklab->d_secsize;
440 		if (bsize != 512 || (dtype!=DTYPE_FLOPPY && tmp!=FS_MSDOS)) {
441 			error = EINVAL;
442 			goto error_exit;
443 		}
444 	}
445 
446 	/*
447 	 * Read the boot sector of the filesystem, and then check the
448 	 * boot signature.  If not a dos boot sector then error out.
449 	 */
450 	if ((error = bread(devvp, 0, 512, NOCRED, &bp)) != 0)
451 		goto error_exit;
452 	bp->b_flags |= B_AGE;
453 	bsp = (union bootsector *)bp->b_data;
454 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
455 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
456 	b710 = (struct byte_bpb710 *)bsp->bs710.bsPBP;
457 
458 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
459 		if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
460 		    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
461 			error = EINVAL;
462 			goto error_exit;
463 		}
464 	}
465 
466 	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
467 	memset((caddr_t)pmp, 0, sizeof *pmp);
468 	pmp->pm_mountp = mp;
469 
470 	/*
471 	 * Compute several useful quantities from the bpb in the
472 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
473 	 * the fields that are different between dos 5 and dos 3.3.
474 	 */
475 	SecPerClust = b50->bpbSecPerClust;
476 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
477 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
478 	pmp->pm_FATs = b50->bpbFATs;
479 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
480 	pmp->pm_Sectors = getushort(b50->bpbSectors);
481 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
482 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
483 	pmp->pm_Heads = getushort(b50->bpbHeads);
484 	pmp->pm_Media = b50->bpbMedia;
485 
486 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
487 		/* XXX - We should probably check more values here */
488     		if (!pmp->pm_BytesPerSec || !SecPerClust
489 	    		|| pmp->pm_Heads > 255 || pmp->pm_SecPerTrack > 63) {
490 			error = EINVAL;
491 			goto error_exit;
492 		}
493 	}
494 
495 	if (pmp->pm_Sectors == 0) {
496 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
497 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
498 	} else {
499 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
500 		pmp->pm_HugeSectors = pmp->pm_Sectors;
501 	}
502 	dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
503 	if (pmp->pm_HugeSectors > 0xffffffff / dirsperblk + 1) {
504 		/*
505 		 * We cannot deal currently with this size of disk
506 		 * due to fileid limitations (see msdosfs_getattr and
507 		 * msdosfs_readdir)
508 		 */
509 		error = EINVAL;
510 		goto error_exit;
511 	}
512 
513 	if (pmp->pm_RootDirEnts == 0) {
514 		if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
515 		    || bsp->bs710.bsBootSectSig3 != BOOTSIG3
516 		    || pmp->pm_Sectors
517 		    || pmp->pm_FATsecs
518 		    || getushort(b710->bpbFSVers)) {
519 			error = EINVAL;
520 			goto error_exit;
521 		}
522 		pmp->pm_fatmask = FAT32_MASK;
523 		pmp->pm_fatmult = 4;
524 		pmp->pm_fatdiv = 1;
525 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
526 
527 		/* mirrorring is enabled if the FATMIRROR bit is not set */
528 		if ((getushort(b710->bpbExtFlags) & FATMIRROR) == 0)
529 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
530 		else
531 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
532 	} else
533 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
534 
535 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
536 		if (FAT32(pmp)) {
537 			/*
538 			 * GEMDOS doesn't know fat32.
539 			 */
540 			error = EINVAL;
541 			goto error_exit;
542 		}
543 
544 		/*
545 		 * Check a few values (could do some more):
546 		 * - logical sector size: power of 2, >= block size
547 		 * - sectors per cluster: power of 2, >= 1
548 		 * - number of sectors:   >= 1, <= size of partition
549 		 */
550 		if ( (SecPerClust == 0)
551 		  || (SecPerClust & (SecPerClust - 1))
552 		  || (pmp->pm_BytesPerSec < bsize)
553 		  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
554 		  || (pmp->pm_HugeSectors == 0)
555 		  || (pmp->pm_HugeSectors * (pmp->pm_BytesPerSec / bsize)
556 							> dpart.part->p_size)
557 		   ) {
558 			error = EINVAL;
559 			goto error_exit;
560 		}
561 		/*
562 		 * XXX - Many parts of the msdos fs driver seem to assume that
563 		 * the number of bytes per logical sector (BytesPerSec) will
564 		 * always be the same as the number of bytes per disk block
565 		 * Let's pretend it is.
566 		 */
567 		tmp = pmp->pm_BytesPerSec / bsize;
568 		pmp->pm_BytesPerSec  = bsize;
569 		pmp->pm_HugeSectors *= tmp;
570 		pmp->pm_HiddenSects *= tmp;
571 		pmp->pm_ResSectors  *= tmp;
572 		pmp->pm_Sectors     *= tmp;
573 		pmp->pm_FATsecs     *= tmp;
574 		SecPerClust         *= tmp;
575 	}
576 	pmp->pm_fatblk = pmp->pm_ResSectors;
577 	if (FAT32(pmp)) {
578 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
579 		pmp->pm_firstcluster = pmp->pm_fatblk
580 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
581 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
582 	} else {
583 		pmp->pm_rootdirblk = pmp->pm_fatblk +
584 			(pmp->pm_FATs * pmp->pm_FATsecs);
585 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
586 				       + pmp->pm_BytesPerSec - 1)
587 			/ pmp->pm_BytesPerSec;/* in sectors */
588 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
589 	}
590 
591 	pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
592 	    SecPerClust;
593 	pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
594 	pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
595 
596 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
597 		if (pmp->pm_nmbrofclusters <= (0xff0 - 2)
598 		      && (dtype == DTYPE_FLOPPY
599 			  || (dtype == DTYPE_VND
600 				&& (pmp->pm_Heads == 1 || pmp->pm_Heads == 2)))
601 		    ) {
602 			pmp->pm_fatmask = FAT12_MASK;
603 			pmp->pm_fatmult = 3;
604 			pmp->pm_fatdiv = 2;
605 		} else {
606 			pmp->pm_fatmask = FAT16_MASK;
607 			pmp->pm_fatmult = 2;
608 			pmp->pm_fatdiv = 1;
609 		}
610 	} else if (pmp->pm_fatmask == 0) {
611 		if (pmp->pm_maxcluster
612 		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
613 			/*
614 			 * This will usually be a floppy disk. This size makes
615 			 * sure that one fat entry will not be split across
616 			 * multiple blocks.
617 			 */
618 			pmp->pm_fatmask = FAT12_MASK;
619 			pmp->pm_fatmult = 3;
620 			pmp->pm_fatdiv = 2;
621 		} else {
622 			pmp->pm_fatmask = FAT16_MASK;
623 			pmp->pm_fatmult = 2;
624 			pmp->pm_fatdiv = 1;
625 		}
626 	}
627 	if (FAT12(pmp))
628 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
629 	else
630 		pmp->pm_fatblocksize = MAXBSIZE;
631 
632 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
633 	pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
634 
635 	/*
636 	 * Compute mask and shift value for isolating cluster relative byte
637 	 * offsets and cluster numbers from a file offset.
638 	 */
639 	pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
640 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
641 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
642 
643 	/*
644 	 * Check for valid cluster size
645 	 * must be a power of 2
646 	 */
647 	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
648 		error = EINVAL;
649 		goto error_exit;
650 	}
651 
652 	/*
653 	 * Release the bootsector buffer.
654 	 */
655 	brelse(bp);
656 	bp = NULL;
657 
658 	/*
659 	 * Check FSInfo.
660 	 */
661 	if (pmp->pm_fsinfo) {
662 		struct fsinfo *fp;
663 
664 		if ((error = bread(devvp, pmp->pm_fsinfo, 1024, NOCRED, &bp)) != 0)
665 			goto error_exit;
666 		fp = (struct fsinfo *)bp->b_data;
667 		if (!memcmp(fp->fsisig1, "RRaA", 4)
668 		    && !memcmp(fp->fsisig2, "rrAa", 4)
669 		    && !memcmp(fp->fsisig3, "\0\0\125\252", 4)
670 		    && !memcmp(fp->fsisig4, "\0\0\125\252", 4))
671 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
672 		else
673 			pmp->pm_fsinfo = 0;
674 		brelse(bp);
675 		bp = NULL;
676 	}
677 
678 	/*
679 	 * Check and validate (or perhaps invalidate?) the fsinfo structure?
680 	 * XXX
681 	 */
682 	if (pmp->pm_fsinfo) {
683 		if (pmp->pm_nxtfree == (u_long)-1)
684 			pmp->pm_fsinfo = 0;
685 	}
686 
687 	/*
688 	 * Allocate memory for the bitmap of allocated clusters, and then
689 	 * fill it in.
690 	 */
691 	pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
692 				   / N_INUSEBITS)
693 				  * sizeof(*pmp->pm_inusemap),
694 				  M_MSDOSFSFAT, M_WAITOK);
695 
696 	/*
697 	 * fillinusemap() needs pm_devvp.
698 	 */
699 	pmp->pm_dev = dev;
700 	pmp->pm_devvp = devvp;
701 
702 	/*
703 	 * Have the inuse map filled in.
704 	 */
705 	if ((error = fillinusemap(pmp)) != 0)
706 		goto error_exit;
707 
708 	/*
709 	 * If they want fat updates to be synchronous then let them suffer
710 	 * the performance degradation in exchange for the on disk copy of
711 	 * the fat being correct just about all the time.  I suppose this
712 	 * would be a good thing to turn on if the kernel is still flakey.
713 	 */
714 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
715 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
716 
717 	/*
718 	 * Finish up.
719 	 */
720 	if (ronly)
721 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
722 	else
723 		pmp->pm_fmod = 1;
724 	mp->mnt_data = pmp;
725         mp->mnt_stat.f_fsid.val[0] = (long)dev;
726         mp->mnt_stat.f_fsid.val[1] = makefstype(MOUNT_MSDOS);
727 	mp->mnt_flag |= MNT_LOCAL;
728 	mp->mnt_dev_bshift = pmp->pm_bnshift;
729 	mp->mnt_fs_bshift = pmp->pm_cnshift;
730 
731 #ifdef QUOTA
732 	/*
733 	 * If we ever do quotas for DOS filesystems this would be a place
734 	 * to fill in the info in the msdosfsmount structure. You dolt,
735 	 * quotas on dos filesystems make no sense because files have no
736 	 * owners on dos filesystems. of course there is some empty space
737 	 * in the directory entry where we could put uid's and gid's.
738 	 */
739 #endif
740 	devvp->v_specmountpoint = mp;
741 
742 	return (0);
743 
744 error_exit:;
745 	if (bp)
746 		brelse(bp);
747 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
748 	(void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, NOCRED, p);
749 	VOP_UNLOCK(devvp, 0);
750 	if (pmp) {
751 		if (pmp->pm_inusemap)
752 			free(pmp->pm_inusemap, M_MSDOSFSFAT);
753 		free(pmp, M_MSDOSFSMNT);
754 		mp->mnt_data = NULL;
755 	}
756 	return (error);
757 }
758 
759 int
760 msdosfs_start(mp, flags, p)
761 	struct mount *mp;
762 	int flags;
763 	struct proc *p;
764 {
765 
766 	return (0);
767 }
768 
769 /*
770  * Unmount the filesystem described by mp.
771  */
772 int
773 msdosfs_unmount(mp, mntflags, p)
774 	struct mount *mp;
775 	int mntflags;
776 	struct proc *p;
777 {
778 	struct msdosfsmount *pmp;
779 	int error, flags;
780 
781 	flags = 0;
782 	if (mntflags & MNT_FORCE)
783 		flags |= FORCECLOSE;
784 #ifdef QUOTA
785 #endif
786 	if ((error = vflush(mp, NULLVP, flags)) != 0)
787 		return (error);
788 	pmp = VFSTOMSDOSFS(mp);
789 	if (pmp->pm_devvp->v_type != VBAD)
790 		pmp->pm_devvp->v_specmountpoint = NULL;
791 #ifdef MSDOSFS_DEBUG
792 	{
793 		struct vnode *vp = pmp->pm_devvp;
794 
795 		printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
796 		printf("flag %08x, usecount %d, writecount %ld, holdcnt %ld\n",
797 		    vp->v_flag, vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
798 		printf("id %lu, mount %p, op %p\n",
799 		    vp->v_id, vp->v_mount, vp->v_op);
800 		printf("freef %p, freeb %p, mount %p\n",
801 		    vp->v_freelist.tqe_next, vp->v_freelist.tqe_prev,
802 		    vp->v_mount);
803 		printf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
804 		    vp->v_cleanblkhd.lh_first,
805 		    vp->v_dirtyblkhd.lh_first,
806 		    vp->v_numoutput, vp->v_type);
807 		printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
808 		    vp->v_socket, vp->v_tag,
809 		    ((u_int *)vp->v_data)[0],
810 		    ((u_int *)vp->v_data)[1]);
811 	}
812 #endif
813 	vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
814 	error = VOP_CLOSE(pmp->pm_devvp,
815 	    pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD|FWRITE, NOCRED, p);
816 	vput(pmp->pm_devvp);
817 	free(pmp->pm_inusemap, M_MSDOSFSFAT);
818 	free(pmp, M_MSDOSFSMNT);
819 	mp->mnt_data = NULL;
820 	mp->mnt_flag &= ~MNT_LOCAL;
821 	return (error);
822 }
823 
824 int
825 msdosfs_root(mp, vpp)
826 	struct mount *mp;
827 	struct vnode **vpp;
828 {
829 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
830 	struct denode *ndep;
831 	int error;
832 
833 #ifdef MSDOSFS_DEBUG
834 	printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
835 #endif
836 	if ((error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep)) != 0)
837 		return (error);
838 	*vpp = DETOV(ndep);
839 	return (0);
840 }
841 
842 int
843 msdosfs_quotactl(mp, cmds, uid, arg, p)
844 	struct mount *mp;
845 	int cmds;
846 	uid_t uid;
847 	caddr_t arg;
848 	struct proc *p;
849 {
850 
851 #ifdef QUOTA
852 	return (EOPNOTSUPP);
853 #else
854 	return (EOPNOTSUPP);
855 #endif
856 }
857 
858 int
859 msdosfs_statfs(mp, sbp, p)
860 	struct mount *mp;
861 	struct statfs *sbp;
862 	struct proc *p;
863 {
864 	struct msdosfsmount *pmp;
865 
866 	pmp = VFSTOMSDOSFS(mp);
867 #ifdef COMPAT_09
868 	sbp->f_type = 4;
869 #else
870 	sbp->f_type = 0;
871 #endif
872 	sbp->f_bsize = pmp->pm_bpcluster;
873 	sbp->f_iosize = pmp->pm_bpcluster;
874 	sbp->f_blocks = pmp->pm_nmbrofclusters;
875 	sbp->f_bfree = pmp->pm_freeclustercount;
876 	sbp->f_bavail = pmp->pm_freeclustercount;
877 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
878 	sbp->f_ffree = 0;	/* what to put in here? */
879 	if (sbp != &mp->mnt_stat) {
880 		memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN);
881 		memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
882 	}
883 	strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
884 	return (0);
885 }
886 
887 int
888 msdosfs_sync(mp, waitfor, cred, p)
889 	struct mount *mp;
890 	int waitfor;
891 	struct ucred *cred;
892 	struct proc *p;
893 {
894 	struct vnode *vp, *nvp;
895 	struct denode *dep;
896 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
897 	int error, allerror = 0;
898 
899 	/*
900 	 * If we ever switch to not updating all of the fats all the time,
901 	 * this would be the place to update them from the first one.
902 	 */
903 	if (pmp->pm_fmod != 0) {
904 		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
905 			panic("msdosfs_sync: rofs mod");
906 		else {
907 			/* update fats here */
908 		}
909 	}
910 	/*
911 	 * Write back each (modified) denode.
912 	 */
913 	simple_lock(&mntvnode_slock);
914 loop:
915 	for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
916 		/*
917 		 * If the vnode that we are about to sync is no longer
918 		 * assoicated with this mount point, start over.
919 		 */
920 		if (vp->v_mount != mp)
921 			goto loop;
922 		simple_lock(&vp->v_interlock);
923 		nvp = vp->v_mntvnodes.le_next;
924 		dep = VTODE(vp);
925 		if (waitfor == MNT_LAZY || vp->v_type == VNON ||
926 		    (((dep->de_flag &
927 		    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0) &&
928 		     (LIST_EMPTY(&vp->v_dirtyblkhd) &&
929 		      vp->v_uobj.uo_npages == 0))) {
930 			simple_unlock(&vp->v_interlock);
931 			continue;
932 		}
933 		simple_unlock(&mntvnode_slock);
934 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK);
935 		if (error) {
936 			simple_lock(&mntvnode_slock);
937 			if (error == ENOENT)
938 				goto loop;
939 			continue;
940 		}
941 		if ((error = VOP_FSYNC(vp, cred,
942 		    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0, p)) != 0)
943 			allerror = error;
944 		vput(vp);
945 		simple_lock(&mntvnode_slock);
946 	}
947 	simple_unlock(&mntvnode_slock);
948 	/*
949 	 * Force stale file system control information to be flushed.
950 	 */
951 	if ((error = VOP_FSYNC(pmp->pm_devvp, cred,
952 	    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0, p)) != 0)
953 		allerror = error;
954 #ifdef QUOTA
955 	/* qsync(mp); */
956 #endif
957 	return (allerror);
958 }
959 
960 int
961 msdosfs_fhtovp(mp, fhp, vpp)
962 	struct mount *mp;
963 	struct fid *fhp;
964 	struct vnode **vpp;
965 {
966 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
967 	struct defid *defhp = (struct defid *) fhp;
968 	struct denode *dep;
969 	int error;
970 
971 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
972 	if (error) {
973 		*vpp = NULLVP;
974 		return (error);
975 	}
976 	*vpp = DETOV(dep);
977 	return (0);
978 }
979 
980 int
981 msdosfs_checkexp(mp, nam, exflagsp, credanonp)
982 	struct mount *mp;
983 	struct mbuf *nam;
984 	int *exflagsp;
985 	struct ucred **credanonp;
986 {
987 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
988 	struct netcred *np;
989 
990 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
991 	if (np == NULL)
992 		return (EACCES);
993 	*exflagsp = np->netc_exflags;
994 	*credanonp = &np->netc_anon;
995 	return (0);
996 }
997 
998 int
999 msdosfs_vptofh(vp, fhp)
1000 	struct vnode *vp;
1001 	struct fid *fhp;
1002 {
1003 	struct denode *dep;
1004 	struct defid *defhp;
1005 
1006 	dep = VTODE(vp);
1007 	defhp = (struct defid *)fhp;
1008 	defhp->defid_len = sizeof(struct defid);
1009 	defhp->defid_dirclust = dep->de_dirclust;
1010 	defhp->defid_dirofs = dep->de_diroffset;
1011 	/* defhp->defid_gen = dep->de_gen; */
1012 	return (0);
1013 }
1014 
1015 int
1016 msdosfs_vget(mp, ino, vpp)
1017 	struct mount *mp;
1018 	ino_t ino;
1019 	struct vnode **vpp;
1020 {
1021 
1022 	return (EOPNOTSUPP);
1023 }
1024 
1025 int
1026 msdosfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
1027 	int *name;
1028 	u_int namelen;
1029 	void *oldp;
1030 	size_t *oldlenp;
1031 	void *newp;
1032 	size_t newlen;
1033 	struct proc *p;
1034 {
1035 	return (EOPNOTSUPP);
1036 }
1037