xref: /netbsd-src/sys/fs/msdosfs/msdosfs_vfsops.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /*	$NetBSD: msdosfs_vfsops.c,v 1.4 2003/04/16 21:44:19 christos 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 1.4 2003/04/16 21:44:19 christos 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 	int error, flags;
249 	mode_t accessmode;
250 
251 	if (mp->mnt_flag & MNT_GETARGS) {
252 		pmp = VFSTOMSDOSFS(mp);
253 		if (pmp == NULL)
254 			return EIO;
255 		args.fspec = NULL;
256 		args.uid = pmp->pm_uid;
257 		args.gid = pmp->pm_gid;
258 		args.mask = pmp->pm_mask;
259 		args.flags = pmp->pm_flags;
260 		vfs_showexport(mp, &args.export, &pmp->pm_export);
261 		return copyout(&args, data, sizeof(args));
262 	}
263 	error = copyin(data, &args, sizeof(struct msdosfs_args));
264 	if (error)
265 		return (error);
266 	/*
267 	 * If updating, check whether changing from read-only to
268 	 * read/write; if there is no device name, that's all we do.
269 	 */
270 	if (mp->mnt_flag & MNT_UPDATE) {
271 		pmp = VFSTOMSDOSFS(mp);
272 		error = 0;
273 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
274 			flags = WRITECLOSE;
275 			if (mp->mnt_flag & MNT_FORCE)
276 				flags |= FORCECLOSE;
277 			error = vflush(mp, NULLVP, flags);
278 		}
279 		if (!error && (mp->mnt_flag & MNT_RELOAD))
280 			/* not yet implemented */
281 			error = EOPNOTSUPP;
282 		if (error)
283 			return (error);
284 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_WANTRDWR)) {
285 			/*
286 			 * If upgrade to read-write by non-root, then verify
287 			 * that user has necessary permissions on the device.
288 			 */
289 			if (p->p_ucred->cr_uid != 0) {
290 				devvp = pmp->pm_devvp;
291 				vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
292 				error = VOP_ACCESS(devvp, VREAD | VWRITE,
293 						   p->p_ucred, p);
294 				VOP_UNLOCK(devvp, 0);
295 				if (error)
296 					return (error);
297 			}
298 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
299 		}
300 		if (args.fspec == 0) {
301 #ifdef	__notyet__		/* doesn't work correctly with current mountd	XXX */
302 			if (args.flags & MSDOSFSMNT_MNTOPT) {
303 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
304 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
305 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
306 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
307 			}
308 #endif
309 			/*
310 			 * Process export requests.
311 			 */
312 			return (vfs_export(mp, &pmp->pm_export, &args.export));
313 		}
314 	}
315 	/*
316 	 * Not an update, or updating the name: look up the name
317 	 * and verify that it refers to a sensible block device.
318 	 */
319 	NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, p);
320 	if ((error = namei(ndp)) != 0)
321 		return (error);
322 	devvp = ndp->ni_vp;
323 
324 	if (devvp->v_type != VBLK) {
325 		vrele(devvp);
326 		return (ENOTBLK);
327 	}
328 	if (bdevsw_lookup(devvp->v_rdev) == NULL) {
329 		vrele(devvp);
330 		return (ENXIO);
331 	}
332 	/*
333 	 * If mount by non-root, then verify that user has necessary
334 	 * permissions on the device.
335 	 */
336 	if (p->p_ucred->cr_uid != 0) {
337 		accessmode = VREAD;
338 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
339 			accessmode |= VWRITE;
340 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
341 		error = VOP_ACCESS(devvp, accessmode, p->p_ucred, p);
342 		VOP_UNLOCK(devvp, 0);
343 		if (error) {
344 			vrele(devvp);
345 			return (error);
346 		}
347 	}
348 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
349 		error = msdosfs_mountfs(devvp, mp, p, &args);
350 #ifdef MSDOSFS_DEBUG		/* only needed for the printf below */
351 		pmp = VFSTOMSDOSFS(mp);
352 #endif
353 	} else {
354 		if (devvp != pmp->pm_devvp)
355 			error = EINVAL;	/* needs translation */
356 		else
357 			vrele(devvp);
358 	}
359 	if (error) {
360 		vrele(devvp);
361 		return (error);
362 	}
363 
364 	if ((error = update_mp(mp, &args)) != 0) {
365 		msdosfs_unmount(mp, MNT_FORCE, p);
366 		return error;
367 	}
368 
369 #ifdef MSDOSFS_DEBUG
370 	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
371 #endif
372 	return set_statfs_info(path, UIO_USERSPACE, args.fspec, UIO_USERSPACE,
373 	    mp, p);
374 }
375 
376 int
377 msdosfs_mountfs(devvp, mp, p, argp)
378 	struct vnode *devvp;
379 	struct mount *mp;
380 	struct proc *p;
381 	struct msdosfs_args *argp;
382 {
383 	struct msdosfsmount *pmp;
384 	struct buf *bp;
385 	dev_t dev = devvp->v_rdev;
386 	struct partinfo dpart;
387 	union bootsector *bsp;
388 	struct byte_bpb33 *b33;
389 	struct byte_bpb50 *b50;
390 	struct byte_bpb710 *b710;
391 	u_int8_t SecPerClust;
392 	int	ronly, error;
393 	int	bsize = 0, dtype = 0, tmp;
394 	u_long	dirsperblk;
395 
396 	/*
397 	 * Disallow multiple mounts of the same device.
398 	 * Disallow mounting of a device that is currently in use
399 	 * (except for root, which might share swap device for miniroot).
400 	 * Flush out any old buffers remaining from a previous use.
401 	 */
402 	if ((error = vfs_mountedon(devvp)) != 0)
403 		return (error);
404 	if (vcount(devvp) > 1 && devvp != rootvp)
405 		return (EBUSY);
406 	if ((error = vinvalbuf(devvp, V_SAVE, p->p_ucred, p, 0, 0)) != 0)
407 		return (error);
408 
409 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
410 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p);
411 	if (error)
412 		return (error);
413 
414 	bp  = NULL; /* both used in error_exit */
415 	pmp = NULL;
416 
417 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
418 		/*
419 	 	 * We need the disklabel to calculate the size of a FAT entry
420 		 * later on. Also make sure the partition contains a filesystem
421 		 * of type FS_MSDOS. This doesn't work for floppies, so we have
422 		 * to check for them too.
423 	 	 *
424 	 	 * At least some parts of the msdos fs driver seem to assume
425 		 * that the size of a disk block will always be 512 bytes.
426 		 * Let's check it...
427 		 */
428 		error = VOP_IOCTL(devvp, DIOCGPART, &dpart, FREAD, NOCRED, p);
429 		if (error)
430 			goto error_exit;
431 		tmp   = dpart.part->p_fstype;
432 		dtype = dpart.disklab->d_type;
433 		bsize = dpart.disklab->d_secsize;
434 		if (bsize != 512 || (dtype!=DTYPE_FLOPPY && tmp!=FS_MSDOS)) {
435 			error = EINVAL;
436 			goto error_exit;
437 		}
438 	}
439 
440 	/*
441 	 * Read the boot sector of the filesystem, and then check the
442 	 * boot signature.  If not a dos boot sector then error out.
443 	 */
444 	if ((error = bread(devvp, 0, 512, NOCRED, &bp)) != 0)
445 		goto error_exit;
446 	bp->b_flags |= B_AGE;
447 	bsp = (union bootsector *)bp->b_data;
448 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
449 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
450 	b710 = (struct byte_bpb710 *)bsp->bs710.bsPBP;
451 
452 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
453 		if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
454 		    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
455 			error = EINVAL;
456 			goto error_exit;
457 		}
458 	}
459 
460 	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
461 	memset(pmp, 0, sizeof *pmp);
462 	pmp->pm_mountp = mp;
463 
464 	/*
465 	 * Compute several useful quantities from the bpb in the
466 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
467 	 * the fields that are different between dos 5 and dos 3.3.
468 	 */
469 	SecPerClust = b50->bpbSecPerClust;
470 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
471 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
472 	pmp->pm_FATs = b50->bpbFATs;
473 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
474 	pmp->pm_Sectors = getushort(b50->bpbSectors);
475 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
476 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
477 	pmp->pm_Heads = getushort(b50->bpbHeads);
478 	pmp->pm_Media = b50->bpbMedia;
479 
480 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
481 		/* XXX - We should probably check more values here */
482     		if (!pmp->pm_BytesPerSec || !SecPerClust
483 	    		|| pmp->pm_Heads > 255 || pmp->pm_SecPerTrack > 63) {
484 			error = EINVAL;
485 			goto error_exit;
486 		}
487 	}
488 
489 	if (pmp->pm_Sectors == 0) {
490 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
491 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
492 	} else {
493 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
494 		pmp->pm_HugeSectors = pmp->pm_Sectors;
495 	}
496 	dirsperblk = pmp->pm_BytesPerSec / sizeof(struct direntry);
497 	if (pmp->pm_HugeSectors > 0xffffffff / dirsperblk + 1) {
498 		/*
499 		 * We cannot deal currently with this size of disk
500 		 * due to fileid limitations (see msdosfs_getattr and
501 		 * msdosfs_readdir)
502 		 */
503 		error = EINVAL;
504 		goto error_exit;
505 	}
506 
507 	if (pmp->pm_RootDirEnts == 0) {
508 		if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
509 		    || bsp->bs710.bsBootSectSig3 != BOOTSIG3
510 		    || pmp->pm_Sectors
511 		    || pmp->pm_FATsecs
512 		    || getushort(b710->bpbFSVers)) {
513 			error = EINVAL;
514 			goto error_exit;
515 		}
516 		pmp->pm_fatmask = FAT32_MASK;
517 		pmp->pm_fatmult = 4;
518 		pmp->pm_fatdiv = 1;
519 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
520 
521 		/* mirrorring is enabled if the FATMIRROR bit is not set */
522 		if ((getushort(b710->bpbExtFlags) & FATMIRROR) == 0)
523 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
524 		else
525 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
526 	} else
527 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
528 
529 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
530 		if (FAT32(pmp)) {
531 			/*
532 			 * GEMDOS doesn't know fat32.
533 			 */
534 			error = EINVAL;
535 			goto error_exit;
536 		}
537 
538 		/*
539 		 * Check a few values (could do some more):
540 		 * - logical sector size: power of 2, >= block size
541 		 * - sectors per cluster: power of 2, >= 1
542 		 * - number of sectors:   >= 1, <= size of partition
543 		 */
544 		if ( (SecPerClust == 0)
545 		  || (SecPerClust & (SecPerClust - 1))
546 		  || (pmp->pm_BytesPerSec < bsize)
547 		  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
548 		  || (pmp->pm_HugeSectors == 0)
549 		  || (pmp->pm_HugeSectors * (pmp->pm_BytesPerSec / bsize)
550 							> dpart.part->p_size)
551 		   ) {
552 			error = EINVAL;
553 			goto error_exit;
554 		}
555 		/*
556 		 * XXX - Many parts of the msdos fs driver seem to assume that
557 		 * the number of bytes per logical sector (BytesPerSec) will
558 		 * always be the same as the number of bytes per disk block
559 		 * Let's pretend it is.
560 		 */
561 		tmp = pmp->pm_BytesPerSec / bsize;
562 		pmp->pm_BytesPerSec  = bsize;
563 		pmp->pm_HugeSectors *= tmp;
564 		pmp->pm_HiddenSects *= tmp;
565 		pmp->pm_ResSectors  *= tmp;
566 		pmp->pm_Sectors     *= tmp;
567 		pmp->pm_FATsecs     *= tmp;
568 		SecPerClust         *= tmp;
569 	}
570 	pmp->pm_fatblk = pmp->pm_ResSectors;
571 	if (FAT32(pmp)) {
572 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
573 		pmp->pm_firstcluster = pmp->pm_fatblk
574 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
575 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
576 	} else {
577 		pmp->pm_rootdirblk = pmp->pm_fatblk +
578 			(pmp->pm_FATs * pmp->pm_FATsecs);
579 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
580 				       + pmp->pm_BytesPerSec - 1)
581 			/ pmp->pm_BytesPerSec;/* in sectors */
582 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
583 	}
584 
585 	pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
586 	    SecPerClust;
587 	pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
588 	pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
589 
590 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
591 		if (pmp->pm_nmbrofclusters <= (0xff0 - 2)
592 		      && (dtype == DTYPE_FLOPPY
593 			  || (dtype == DTYPE_VND
594 				&& (pmp->pm_Heads == 1 || pmp->pm_Heads == 2)))
595 		    ) {
596 			pmp->pm_fatmask = FAT12_MASK;
597 			pmp->pm_fatmult = 3;
598 			pmp->pm_fatdiv = 2;
599 		} else {
600 			pmp->pm_fatmask = FAT16_MASK;
601 			pmp->pm_fatmult = 2;
602 			pmp->pm_fatdiv = 1;
603 		}
604 	} else if (pmp->pm_fatmask == 0) {
605 		if (pmp->pm_maxcluster
606 		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
607 			/*
608 			 * This will usually be a floppy disk. This size makes
609 			 * sure that one fat entry will not be split across
610 			 * multiple blocks.
611 			 */
612 			pmp->pm_fatmask = FAT12_MASK;
613 			pmp->pm_fatmult = 3;
614 			pmp->pm_fatdiv = 2;
615 		} else {
616 			pmp->pm_fatmask = FAT16_MASK;
617 			pmp->pm_fatmult = 2;
618 			pmp->pm_fatdiv = 1;
619 		}
620 	}
621 	if (FAT12(pmp))
622 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
623 	else
624 		pmp->pm_fatblocksize = MAXBSIZE;
625 
626 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
627 	pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
628 
629 	/*
630 	 * Compute mask and shift value for isolating cluster relative byte
631 	 * offsets and cluster numbers from a file offset.
632 	 */
633 	pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
634 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
635 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
636 
637 	/*
638 	 * Check for valid cluster size
639 	 * must be a power of 2
640 	 */
641 	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
642 		error = EINVAL;
643 		goto error_exit;
644 	}
645 
646 	/*
647 	 * Release the bootsector buffer.
648 	 */
649 	brelse(bp);
650 	bp = NULL;
651 
652 	/*
653 	 * Check FSInfo.
654 	 */
655 	if (pmp->pm_fsinfo) {
656 		struct fsinfo *fp;
657 
658 		if ((error = bread(devvp, pmp->pm_fsinfo, 1024, NOCRED, &bp)) != 0)
659 			goto error_exit;
660 		fp = (struct fsinfo *)bp->b_data;
661 		if (!memcmp(fp->fsisig1, "RRaA", 4)
662 		    && !memcmp(fp->fsisig2, "rrAa", 4)
663 		    && !memcmp(fp->fsisig3, "\0\0\125\252", 4)
664 		    && !memcmp(fp->fsisig4, "\0\0\125\252", 4))
665 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
666 		else
667 			pmp->pm_fsinfo = 0;
668 		brelse(bp);
669 		bp = NULL;
670 	}
671 
672 	/*
673 	 * Check and validate (or perhaps invalidate?) the fsinfo structure?
674 	 * XXX
675 	 */
676 	if (pmp->pm_fsinfo) {
677 		if (pmp->pm_nxtfree == (u_long)-1)
678 			pmp->pm_fsinfo = 0;
679 	}
680 
681 	/*
682 	 * Allocate memory for the bitmap of allocated clusters, and then
683 	 * fill it in.
684 	 */
685 	pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
686 				   / N_INUSEBITS)
687 				  * sizeof(*pmp->pm_inusemap),
688 				  M_MSDOSFSFAT, M_WAITOK);
689 
690 	/*
691 	 * fillinusemap() needs pm_devvp.
692 	 */
693 	pmp->pm_dev = dev;
694 	pmp->pm_devvp = devvp;
695 
696 	/*
697 	 * Have the inuse map filled in.
698 	 */
699 	if ((error = fillinusemap(pmp)) != 0)
700 		goto error_exit;
701 
702 	/*
703 	 * If they want fat updates to be synchronous then let them suffer
704 	 * the performance degradation in exchange for the on disk copy of
705 	 * the fat being correct just about all the time.  I suppose this
706 	 * would be a good thing to turn on if the kernel is still flakey.
707 	 */
708 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
709 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
710 
711 	/*
712 	 * Finish up.
713 	 */
714 	if (ronly)
715 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
716 	else
717 		pmp->pm_fmod = 1;
718 	mp->mnt_data = pmp;
719         mp->mnt_stat.f_fsid.val[0] = (long)dev;
720         mp->mnt_stat.f_fsid.val[1] = makefstype(MOUNT_MSDOS);
721 	mp->mnt_flag |= MNT_LOCAL;
722 	mp->mnt_dev_bshift = pmp->pm_bnshift;
723 	mp->mnt_fs_bshift = pmp->pm_cnshift;
724 
725 #ifdef QUOTA
726 	/*
727 	 * If we ever do quotas for DOS filesystems this would be a place
728 	 * to fill in the info in the msdosfsmount structure. You dolt,
729 	 * quotas on dos filesystems make no sense because files have no
730 	 * owners on dos filesystems. of course there is some empty space
731 	 * in the directory entry where we could put uid's and gid's.
732 	 */
733 #endif
734 	devvp->v_specmountpoint = mp;
735 
736 	return (0);
737 
738 error_exit:;
739 	if (bp)
740 		brelse(bp);
741 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
742 	(void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD|FWRITE, NOCRED, p);
743 	VOP_UNLOCK(devvp, 0);
744 	if (pmp) {
745 		if (pmp->pm_inusemap)
746 			free(pmp->pm_inusemap, M_MSDOSFSFAT);
747 		free(pmp, M_MSDOSFSMNT);
748 		mp->mnt_data = NULL;
749 	}
750 	return (error);
751 }
752 
753 int
754 msdosfs_start(mp, flags, p)
755 	struct mount *mp;
756 	int flags;
757 	struct proc *p;
758 {
759 
760 	return (0);
761 }
762 
763 /*
764  * Unmount the filesystem described by mp.
765  */
766 int
767 msdosfs_unmount(mp, mntflags, p)
768 	struct mount *mp;
769 	int mntflags;
770 	struct proc *p;
771 {
772 	struct msdosfsmount *pmp;
773 	int error, flags;
774 
775 	flags = 0;
776 	if (mntflags & MNT_FORCE)
777 		flags |= FORCECLOSE;
778 #ifdef QUOTA
779 #endif
780 	if ((error = vflush(mp, NULLVP, flags)) != 0)
781 		return (error);
782 	pmp = VFSTOMSDOSFS(mp);
783 	if (pmp->pm_devvp->v_type != VBAD)
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 %08x, usecount %d, writecount %ld, holdcnt %ld\n",
791 		    vp->v_flag, vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
792 		printf("id %lu, mount %p, op %p\n",
793 		    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 %d, 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 	vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
808 	error = VOP_CLOSE(pmp->pm_devvp,
809 	    pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD|FWRITE, NOCRED, p);
810 	vput(pmp->pm_devvp);
811 	free(pmp->pm_inusemap, M_MSDOSFSFAT);
812 	free(pmp, M_MSDOSFSMNT);
813 	mp->mnt_data = NULL;
814 	mp->mnt_flag &= ~MNT_LOCAL;
815 	return (error);
816 }
817 
818 int
819 msdosfs_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 	if ((error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep)) != 0)
831 		return (error);
832 	*vpp = DETOV(ndep);
833 	return (0);
834 }
835 
836 int
837 msdosfs_quotactl(mp, cmds, uid, arg, p)
838 	struct mount *mp;
839 	int cmds;
840 	uid_t uid;
841 	caddr_t arg;
842 	struct proc *p;
843 {
844 
845 #ifdef QUOTA
846 	return (EOPNOTSUPP);
847 #else
848 	return (EOPNOTSUPP);
849 #endif
850 }
851 
852 int
853 msdosfs_statfs(mp, sbp, p)
854 	struct mount *mp;
855 	struct statfs *sbp;
856 	struct proc *p;
857 {
858 	struct msdosfsmount *pmp;
859 
860 	pmp = VFSTOMSDOSFS(mp);
861 #ifdef COMPAT_09
862 	sbp->f_type = 4;
863 #else
864 	sbp->f_type = 0;
865 #endif
866 	sbp->f_bsize = pmp->pm_bpcluster;
867 	sbp->f_iosize = pmp->pm_bpcluster;
868 	sbp->f_blocks = pmp->pm_nmbrofclusters;
869 	sbp->f_bfree = pmp->pm_freeclustercount;
870 	sbp->f_bavail = pmp->pm_freeclustercount;
871 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
872 	sbp->f_ffree = 0;	/* what to put in here? */
873 	copy_statfs_info(sbp, mp);
874 	return (0);
875 }
876 
877 int
878 msdosfs_sync(mp, waitfor, cred, p)
879 	struct mount *mp;
880 	int waitfor;
881 	struct ucred *cred;
882 	struct proc *p;
883 {
884 	struct vnode *vp, *nvp;
885 	struct denode *dep;
886 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
887 	int error, allerror = 0;
888 
889 	/*
890 	 * If we ever switch to not updating all of the fats all the time,
891 	 * this would be the place to update them from the first one.
892 	 */
893 	if (pmp->pm_fmod != 0) {
894 		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
895 			panic("msdosfs_sync: rofs mod");
896 		else {
897 			/* update fats here */
898 		}
899 	}
900 	/*
901 	 * Write back each (modified) denode.
902 	 */
903 	simple_lock(&mntvnode_slock);
904 loop:
905 	for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
906 		/*
907 		 * If the vnode that we are about to sync is no longer
908 		 * assoicated with this mount point, start over.
909 		 */
910 		if (vp->v_mount != mp)
911 			goto loop;
912 		simple_lock(&vp->v_interlock);
913 		nvp = vp->v_mntvnodes.le_next;
914 		dep = VTODE(vp);
915 		if (waitfor == MNT_LAZY || vp->v_type == VNON ||
916 		    (((dep->de_flag &
917 		    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0) &&
918 		     (LIST_EMPTY(&vp->v_dirtyblkhd) &&
919 		      vp->v_uobj.uo_npages == 0))) {
920 			simple_unlock(&vp->v_interlock);
921 			continue;
922 		}
923 		simple_unlock(&mntvnode_slock);
924 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK);
925 		if (error) {
926 			simple_lock(&mntvnode_slock);
927 			if (error == ENOENT)
928 				goto loop;
929 			continue;
930 		}
931 		if ((error = VOP_FSYNC(vp, cred,
932 		    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0, p)) != 0)
933 			allerror = error;
934 		vput(vp);
935 		simple_lock(&mntvnode_slock);
936 	}
937 	simple_unlock(&mntvnode_slock);
938 	/*
939 	 * Force stale file system control information to be flushed.
940 	 */
941 	if ((error = VOP_FSYNC(pmp->pm_devvp, cred,
942 	    waitfor == MNT_WAIT ? FSYNC_WAIT : 0, 0, 0, p)) != 0)
943 		allerror = error;
944 #ifdef QUOTA
945 	/* qsync(mp); */
946 #endif
947 	return (allerror);
948 }
949 
950 int
951 msdosfs_fhtovp(mp, fhp, vpp)
952 	struct mount *mp;
953 	struct fid *fhp;
954 	struct vnode **vpp;
955 {
956 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
957 	struct defid *defhp = (struct defid *) fhp;
958 	struct denode *dep;
959 	int error;
960 
961 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
962 	if (error) {
963 		*vpp = NULLVP;
964 		return (error);
965 	}
966 	*vpp = DETOV(dep);
967 	return (0);
968 }
969 
970 int
971 msdosfs_checkexp(mp, nam, exflagsp, credanonp)
972 	struct mount *mp;
973 	struct mbuf *nam;
974 	int *exflagsp;
975 	struct ucred **credanonp;
976 {
977 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
978 	struct netcred *np;
979 
980 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
981 	if (np == NULL)
982 		return (EACCES);
983 	*exflagsp = np->netc_exflags;
984 	*credanonp = &np->netc_anon;
985 	return (0);
986 }
987 
988 int
989 msdosfs_vptofh(vp, fhp)
990 	struct vnode *vp;
991 	struct fid *fhp;
992 {
993 	struct denode *dep;
994 	struct defid *defhp;
995 
996 	dep = VTODE(vp);
997 	defhp = (struct defid *)fhp;
998 	defhp->defid_len = sizeof(struct defid);
999 	defhp->defid_dirclust = dep->de_dirclust;
1000 	defhp->defid_dirofs = dep->de_diroffset;
1001 	/* defhp->defid_gen = dep->de_gen; */
1002 	return (0);
1003 }
1004 
1005 int
1006 msdosfs_vget(mp, ino, vpp)
1007 	struct mount *mp;
1008 	ino_t ino;
1009 	struct vnode **vpp;
1010 {
1011 
1012 	return (EOPNOTSUPP);
1013 }
1014 
1015 int
1016 msdosfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
1017 	int *name;
1018 	u_int namelen;
1019 	void *oldp;
1020 	size_t *oldlenp;
1021 	void *newp;
1022 	size_t newlen;
1023 	struct proc *p;
1024 {
1025 	return (EOPNOTSUPP);
1026 }
1027