xref: /freebsd/sys/fs/msdosfs/msdosfs_vfsops.c (revision 5129159789cc9d7bc514e4546b88e3427695002d)
1 /* $FreeBSD$ */
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/conf.h>
54 #include <sys/namei.h>
55 #include <sys/proc.h>
56 #include <sys/kernel.h>
57 #include <sys/vnode.h>
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 #include <vm/vm_zone.h>
64 
65 #include <msdosfs/bpb.h>
66 #include <msdosfs/bootsect.h>
67 #include <msdosfs/direntry.h>
68 #include <msdosfs/denode.h>
69 #include <msdosfs/msdosfsmount.h>
70 #include <msdosfs/fat.h>
71 
72 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
73 static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
74 
75 static int	update_mp __P((struct mount *mp, struct msdosfs_args *argp));
76 static int	mountmsdosfs __P((struct vnode *devvp, struct mount *mp,
77 				  struct proc *p, struct msdosfs_args *argp));
78 static int	msdosfs_fhtovp __P((struct mount *, struct fid *,
79 				    struct vnode **));
80 static int	msdosfs_checkexp __P((struct mount *, struct sockaddr *,
81 				    int *, struct ucred **));
82 static int	msdosfs_mount __P((struct mount *, char *, caddr_t,
83 				   struct nameidata *, struct proc *));
84 static int	msdosfs_root __P((struct mount *, struct vnode **));
85 static int	msdosfs_statfs __P((struct mount *, struct statfs *,
86 				    struct proc *));
87 static int	msdosfs_sync __P((struct mount *, int, struct ucred *,
88 				  struct proc *));
89 static int	msdosfs_unmount __P((struct mount *, int, struct proc *));
90 static int	msdosfs_vptofh __P((struct vnode *, struct fid *));
91 
92 static int
93 update_mp(mp, argp)
94 	struct mount *mp;
95 	struct msdosfs_args *argp;
96 {
97 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
98 	int error;
99 
100 	pmp->pm_gid = argp->gid;
101 	pmp->pm_uid = argp->uid;
102 	pmp->pm_mask = argp->mask & ALLPERMS;
103 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
104 	if (pmp->pm_flags & MSDOSFSMNT_U2WTABLE) {
105 		bcopy(argp->u2w, pmp->pm_u2w, sizeof(pmp->pm_u2w));
106 		bcopy(argp->d2u, pmp->pm_d2u, sizeof(pmp->pm_d2u));
107 		bcopy(argp->u2d, pmp->pm_u2d, sizeof(pmp->pm_u2d));
108 	}
109 	if (pmp->pm_flags & MSDOSFSMNT_ULTABLE) {
110 		bcopy(argp->ul, pmp->pm_ul, sizeof(pmp->pm_ul));
111 		bcopy(argp->lu, pmp->pm_lu, sizeof(pmp->pm_lu));
112 	}
113 
114 #ifndef __FreeBSD__
115 	/*
116 	 * GEMDOS knows nothing (yet) about win95
117 	 */
118 	if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
119 		pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
120 #endif
121 
122 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
123 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
124 	else if (!(pmp->pm_flags &
125 	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
126 		struct vnode *rootvp;
127 
128 		/*
129 		 * Try to divine whether to support Win'95 long filenames
130 		 */
131 		if (FAT32(pmp))
132 			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
133 		else {
134 			if ((error = msdosfs_root(mp, &rootvp)) != 0)
135 				return error;
136 			pmp->pm_flags |= findwin95(VTODE(rootvp))
137 				? MSDOSFSMNT_LONGNAME
138 					: MSDOSFSMNT_SHORTNAME;
139 			vput(rootvp);
140 		}
141 	}
142 	return 0;
143 }
144 
145 #ifndef __FreeBSD__
146 int
147 msdosfs_mountroot()
148 {
149 	register struct mount *mp;
150 	struct proc *p = curproc;	/* XXX */
151 	size_t size;
152 	int error;
153 	struct msdosfs_args args;
154 
155 	if (root_device->dv_class != DV_DISK)
156 		return (ENODEV);
157 
158 	/*
159 	 * Get vnodes for swapdev and rootdev.
160 	 */
161 	if (bdevvp(rootdev, &rootvp))
162 		panic("msdosfs_mountroot: can't setup rootvp");
163 
164 	mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
165 	bzero((char *)mp, (u_long)sizeof(struct mount));
166 	mp->mnt_op = &msdosfs_vfsops;
167 	mp->mnt_flag = 0;
168 	LIST_INIT(&mp->mnt_vnodelist);
169 
170 	args.flags = 0;
171 	args.uid = 0;
172 	args.gid = 0;
173 	args.mask = 0777;
174 
175 	if ((error = mountmsdosfs(rootvp, mp, p, &args)) != 0) {
176 		free(mp, M_MOUNT);
177 		return (error);
178 	}
179 
180 	if ((error = update_mp(mp, &args)) != 0) {
181 		(void)msdosfs_unmount(mp, 0, p);
182 		free(mp, M_MOUNT);
183 		return (error);
184 	}
185 
186 	if ((error = vfs_lock(mp)) != 0) {
187 		(void)msdosfs_unmount(mp, 0, p);
188 		free(mp, M_MOUNT);
189 		return (error);
190 	}
191 
192 	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
193 	mp->mnt_vnodecovered = NULLVP;
194 	(void) copystr("/", mp->mnt_stat.f_mntonname, MNAMELEN - 1,
195 	    &size);
196 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
197 	(void) copystr(ROOTNAME, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
198 	    &size);
199 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
200 	(void)msdosfs_statfs(mp, &mp->mnt_stat, p);
201 	vfs_unlock(mp);
202 	return (0);
203 }
204 #endif
205 
206 /*
207  * mp - path - addr in user space of mount point (ie /usr or whatever)
208  * data - addr in user space of mount params including the name of the block
209  * special file to treat as a filesystem.
210  */
211 static int
212 msdosfs_mount(mp, path, data, ndp, p)
213 	struct mount *mp;
214 	char *path;
215 	caddr_t data;
216 	struct nameidata *ndp;
217 	struct proc *p;
218 {
219 	struct vnode *devvp;	  /* vnode for blk device to mount */
220 	struct msdosfs_args args; /* will hold data from mount request */
221 	/* msdosfs specific mount control block */
222 	struct msdosfsmount *pmp = NULL;
223 	size_t size;
224 	int error, flags;
225 	mode_t accessmode;
226 
227 	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
228 	if (error)
229 		return (error);
230 	if (args.magic != MSDOSFS_ARGSMAGIC)
231 		args.flags = 0;
232 	/*
233 	 * If updating, check whether changing from read-only to
234 	 * read/write; if there is no device name, that's all we do.
235 	 */
236 	if (mp->mnt_flag & MNT_UPDATE) {
237 		pmp = VFSTOMSDOSFS(mp);
238 		error = 0;
239 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
240 			flags = WRITECLOSE;
241 			if (mp->mnt_flag & MNT_FORCE)
242 				flags |= FORCECLOSE;
243 			error = vflush(mp, NULLVP, flags);
244 		}
245 		if (!error && (mp->mnt_flag & MNT_RELOAD))
246 			/* not yet implemented */
247 			error = EOPNOTSUPP;
248 		if (error)
249 			return (error);
250 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
251 			/*
252 			 * If upgrade to read-write by non-root, then verify
253 			 * that user has necessary permissions on the device.
254 			 */
255 			if (p->p_ucred->cr_uid != 0) {
256 				devvp = pmp->pm_devvp;
257 				vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
258 				error = VOP_ACCESS(devvp, VREAD | VWRITE,
259 						   p->p_ucred, p);
260 				if (error) {
261 					VOP_UNLOCK(devvp, 0, p);
262 					return (error);
263 				}
264 				VOP_UNLOCK(devvp, 0, p);
265 			}
266 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
267 		}
268 		if (args.fspec == 0) {
269 #ifdef	__notyet__		/* doesn't work correctly with current mountd	XXX */
270 			if (args.flags & MSDOSFSMNT_MNTOPT) {
271 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
272 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
273 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
274 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
275 			}
276 #endif
277 			/*
278 			 * Process export requests.
279 			 */
280 			return (vfs_export(mp, &pmp->pm_export, &args.export));
281 		}
282 	}
283 	/*
284 	 * Not an update, or updating the name: look up the name
285 	 * and verify that it refers to a sensible block device.
286 	 */
287 	NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, p);
288 	error = namei(ndp);
289 	if (error)
290 		return (error);
291 	devvp = ndp->ni_vp;
292 	NDFREE(ndp, NDF_ONLY_PNBUF);
293 
294 	if (!vn_isdisk(devvp)) {
295 		vrele(devvp);
296 		return (ENOTBLK);
297 	}
298 	/*
299 	 * If mount by non-root, then verify that user has necessary
300 	 * permissions on the device.
301 	 */
302 	if (p->p_ucred->cr_uid != 0) {
303 		accessmode = VREAD;
304 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
305 			accessmode |= VWRITE;
306 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
307 		error = VOP_ACCESS(devvp, accessmode, p->p_ucred, p);
308 		if (error) {
309 			vput(devvp);
310 			return (error);
311 		}
312 		VOP_UNLOCK(devvp, 0, p);
313 	}
314 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
315 		error = mountmsdosfs(devvp, mp, p, &args);
316 #ifdef MSDOSFS_DEBUG		/* only needed for the printf below */
317 		pmp = VFSTOMSDOSFS(mp);
318 #endif
319 	} else {
320 		if (devvp != pmp->pm_devvp)
321 			error = EINVAL;	/* XXX needs translation */
322 		else
323 			vrele(devvp);
324 	}
325 	if (error) {
326 		vrele(devvp);
327 		return (error);
328 	}
329 
330 	error = update_mp(mp, &args);
331 	if (error) {
332 		msdosfs_unmount(mp, MNT_FORCE, p);
333 		return error;
334 	}
335 
336 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
337 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
338 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
339 	    &size);
340 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
341 	(void) msdosfs_statfs(mp, &mp->mnt_stat, p);
342 #ifdef MSDOSFS_DEBUG
343 	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
344 #endif
345 	return (0);
346 }
347 
348 static int
349 mountmsdosfs(devvp, mp, p, argp)
350 	struct vnode *devvp;
351 	struct mount *mp;
352 	struct proc *p;
353 	struct msdosfs_args *argp;
354 {
355 	struct msdosfsmount *pmp;
356 	struct buf *bp;
357 	dev_t dev = devvp->v_rdev;
358 #ifndef __FreeBSD__
359 	struct partinfo dpart;
360 	int bsize = 0, dtype = 0, tmp;
361 #endif
362 	union bootsector *bsp;
363 	struct byte_bpb33 *b33;
364 	struct byte_bpb50 *b50;
365 	struct byte_bpb710 *b710;
366 	u_int8_t SecPerClust;
367 	int	ronly, error;
368 
369 	/*
370 	 * Disallow multiple mounts of the same device.
371 	 * Disallow mounting of a device that is currently in use
372 	 * (except for root, which might share swap device for miniroot).
373 	 * Flush out any old buffers remaining from a previous use.
374 	 */
375 	error = vfs_mountedon(devvp);
376 	if (error)
377 		return (error);
378 	if (vcount(devvp) > 1 && devvp != rootvp)
379 		return (EBUSY);
380 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
381 	error = vinvalbuf(devvp, V_SAVE, p->p_ucred, p, 0, 0);
382 	VOP_UNLOCK(devvp, 0, p);
383 	if (error)
384 		return (error);
385 
386 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
387 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, p);
388 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, p);
389 	VOP_UNLOCK(devvp, 0, p);
390 	if (error)
391 		return (error);
392 
393 	bp  = NULL; /* both used in error_exit */
394 	pmp = NULL;
395 
396 #ifndef __FreeBSD__
397 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
398 		/*
399 	 	 * We need the disklabel to calculate the size of a FAT entry
400 		 * later on. Also make sure the partition contains a filesystem
401 		 * of type FS_MSDOS. This doesn't work for floppies, so we have
402 		 * to check for them too.
403 	 	 *
404 	 	 * At least some parts of the msdos fs driver seem to assume
405 		 * that the size of a disk block will always be 512 bytes.
406 		 * Let's check it...
407 		 */
408 		error = VOP_IOCTL(devvp, DIOCGPART, (caddr_t)&dpart,
409 				  FREAD, NOCRED, p);
410 		if (error)
411 			goto error_exit;
412 		tmp   = dpart.part->p_fstype;
413 		dtype = dpart.disklab->d_type;
414 		bsize = dpart.disklab->d_secsize;
415 		if (bsize != 512 || (dtype!=DTYPE_FLOPPY && tmp!=FS_MSDOS)) {
416 			error = EINVAL;
417 			goto error_exit;
418 		}
419 	}
420 #endif
421 
422 	/*
423 	 * Read the boot sector of the filesystem, and then check the
424 	 * boot signature.  If not a dos boot sector then error out.
425 	 */
426 #ifdef	PC98
427 	error = bread(devvp, 0, 1024, NOCRED, &bp);
428 #else
429 	error = bread(devvp, 0, 512, NOCRED, &bp);
430 #endif
431 	if (error)
432 		goto error_exit;
433 	bp->b_flags |= B_AGE;
434 	bsp = (union bootsector *)bp->b_data;
435 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
436 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
437 	b710 = (struct byte_bpb710 *)bsp->bs710.bsPBP;
438 
439 #ifndef __FreeBSD__
440 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
441 #endif
442 #ifdef PC98
443 		if ((bsp->bs50.bsBootSectSig0 != BOOTSIG0
444 		    || bsp->bs50.bsBootSectSig1 != BOOTSIG1)
445 		    && (bsp->bs50.bsBootSectSig0 != 0       /* PC98 DOS 3.3x */
446 		    || bsp->bs50.bsBootSectSig1 != 0)
447 		    && (bsp->bs50.bsBootSectSig0 != 0x90    /* PC98 DOS 5.0  */
448 		    || bsp->bs50.bsBootSectSig1 != 0x3d)
449 		    && (bsp->bs50.bsBootSectSig0 != 0x46    /* PC98 DOS 3.3B */
450 		    || bsp->bs50.bsBootSectSig1 != 0xfa)) {
451 #else
452 		if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
453 		    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
454 #endif
455 			error = EINVAL;
456 			goto error_exit;
457 		}
458 #ifndef __FreeBSD__
459 	}
460 #endif
461 
462 	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
463 	bzero((caddr_t)pmp, sizeof *pmp);
464 	pmp->pm_mountp = mp;
465 
466 	/*
467 	 * Compute several useful quantities from the bpb in the
468 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
469 	 * the fields that are different between dos 5 and dos 3.3.
470 	 */
471 	SecPerClust = b50->bpbSecPerClust;
472 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
473 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
474 	pmp->pm_FATs = b50->bpbFATs;
475 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
476 	pmp->pm_Sectors = getushort(b50->bpbSectors);
477 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
478 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
479 	pmp->pm_Heads = getushort(b50->bpbHeads);
480 	pmp->pm_Media = b50->bpbMedia;
481 
482 #ifndef __FreeBSD__
483 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
484 #endif
485 		/* XXX - We should probably check more values here */
486 		if (!pmp->pm_BytesPerSec || !SecPerClust
487 			|| !pmp->pm_Heads || pmp->pm_Heads > 255
488 #ifdef PC98
489 	    		|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 255) {
490 #else
491 			|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 63) {
492 #endif
493 			error = EINVAL;
494 			goto error_exit;
495 		}
496 #ifndef __FreeBSD__
497 	}
498 #endif
499 
500 	if (pmp->pm_Sectors == 0) {
501 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
502 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
503 	} else {
504 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
505 		pmp->pm_HugeSectors = pmp->pm_Sectors;
506 	}
507 	if (pmp->pm_HugeSectors > 0xffffffff /
508 	    (pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) {
509 		/*
510 		 * We cannot deal currently with this size of disk
511 		 * due to fileid limitations (see msdosfs_getattr and
512 		 * msdosfs_readdir)
513 		 */
514 		error = EINVAL;
515 		printf("mountmsdosfs(): disk too big, sorry\n");
516 		goto error_exit;
517 	}
518 
519 	if (pmp->pm_RootDirEnts == 0) {
520 		if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
521 		    || bsp->bs710.bsBootSectSig3 != BOOTSIG3
522 		    || pmp->pm_Sectors
523 		    || pmp->pm_FATsecs
524 		    || getushort(b710->bpbFSVers)) {
525 			error = EINVAL;
526 			printf("mountmsdosfs(): bad FAT32 filesystem\n");
527 			goto error_exit;
528 		}
529 		pmp->pm_fatmask = FAT32_MASK;
530 		pmp->pm_fatmult = 4;
531 		pmp->pm_fatdiv = 1;
532 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
533 		if (getushort(b710->bpbExtFlags) & FATMIRROR)
534 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
535 		else
536 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
537 	} else
538 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
539 
540 #ifndef __FreeBSD__
541 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
542 		if (FAT32(pmp)) {
543 			/*
544 			 * GEMDOS doesn't know fat32.
545 			 */
546 			error = EINVAL;
547 			goto error_exit;
548 		}
549 
550 		/*
551 		 * Check a few values (could do some more):
552 		 * - logical sector size: power of 2, >= block size
553 		 * - sectors per cluster: power of 2, >= 1
554 		 * - number of sectors:   >= 1, <= size of partition
555 		 */
556 		if ( (SecPerClust == 0)
557 		  || (SecPerClust & (SecPerClust - 1))
558 		  || (pmp->pm_BytesPerSec < bsize)
559 		  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
560 		  || (pmp->pm_HugeSectors == 0)
561 		  || (pmp->pm_HugeSectors * (pmp->pm_BytesPerSec / bsize)
562 							> dpart.part->p_size)
563 		   ) {
564 			error = EINVAL;
565 			goto error_exit;
566 		}
567 		/*
568 		 * XXX - Many parts of the msdos fs driver seem to assume that
569 		 * the number of bytes per logical sector (BytesPerSec) will
570 		 * always be the same as the number of bytes per disk block
571 		 * Let's pretend it is.
572 		 */
573 		tmp = pmp->pm_BytesPerSec / bsize;
574 		pmp->pm_BytesPerSec  = bsize;
575 		pmp->pm_HugeSectors *= tmp;
576 		pmp->pm_HiddenSects *= tmp;
577 		pmp->pm_ResSectors  *= tmp;
578 		pmp->pm_Sectors     *= tmp;
579 		pmp->pm_FATsecs     *= tmp;
580 		SecPerClust         *= tmp;
581 	}
582 #endif
583 	pmp->pm_fatblk = pmp->pm_ResSectors;
584 	if (FAT32(pmp)) {
585 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
586 		pmp->pm_firstcluster = pmp->pm_fatblk
587 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
588 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo);
589 	} else {
590 		pmp->pm_rootdirblk = pmp->pm_fatblk +
591 			(pmp->pm_FATs * pmp->pm_FATsecs);
592 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
593 				       + pmp->pm_BytesPerSec - 1)
594 			/ pmp->pm_BytesPerSec;/* in sectors */
595 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
596 	}
597 
598 	pmp->pm_nmbrofclusters = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
599 	    SecPerClust;
600 	pmp->pm_maxcluster = pmp->pm_nmbrofclusters + 1;
601 	pmp->pm_fatsize = pmp->pm_FATsecs * pmp->pm_BytesPerSec;
602 
603 #ifndef __FreeBSD__
604 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
605 		if ((pmp->pm_nmbrofclusters <= (0xff0 - 2))
606 		      && ((dtype == DTYPE_FLOPPY) || ((dtype == DTYPE_VNODE)
607 		      && ((pmp->pm_Heads == 1) || (pmp->pm_Heads == 2))))
608 		    ) {
609 			pmp->pm_fatmask = FAT12_MASK;
610 			pmp->pm_fatmult = 3;
611 			pmp->pm_fatdiv = 2;
612 		} else {
613 			pmp->pm_fatmask = FAT16_MASK;
614 			pmp->pm_fatmult = 2;
615 			pmp->pm_fatdiv = 1;
616 		}
617 	} else
618 #endif
619 	if (pmp->pm_fatmask == 0) {
620 		if (pmp->pm_maxcluster
621 		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
622 			/*
623 			 * This will usually be a floppy disk. This size makes
624 			 * sure that one fat entry will not be split across
625 			 * multiple blocks.
626 			 */
627 			pmp->pm_fatmask = FAT12_MASK;
628 			pmp->pm_fatmult = 3;
629 			pmp->pm_fatdiv = 2;
630 		} else {
631 			pmp->pm_fatmask = FAT16_MASK;
632 			pmp->pm_fatmult = 2;
633 			pmp->pm_fatdiv = 1;
634 		}
635 	}
636 	if (FAT12(pmp))
637 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
638 	else
639 		pmp->pm_fatblocksize = DFLTBSIZE;
640 
641 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / pmp->pm_BytesPerSec;
642 	pmp->pm_bnshift = ffs(pmp->pm_BytesPerSec) - 1;
643 
644 	/*
645 	 * Compute mask and shift value for isolating cluster relative byte
646 	 * offsets and cluster numbers from a file offset.
647 	 */
648 	pmp->pm_bpcluster = SecPerClust * pmp->pm_BytesPerSec;
649 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
650 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
651 
652 	/*
653 	 * Check for valid cluster size
654 	 * must be a power of 2
655 	 */
656 	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
657 		error = EINVAL;
658 		goto error_exit;
659 	}
660 
661 	/*
662 	 * Release the bootsector buffer.
663 	 */
664 	brelse(bp);
665 	bp = NULL;
666 
667 	/*
668 	 * Check FSInfo.
669 	 */
670 	if (pmp->pm_fsinfo) {
671 		struct fsinfo *fp;
672 
673 		if ((error = bread(devvp, pmp->pm_fsinfo, 1024, NOCRED, &bp)) != 0)
674 			goto error_exit;
675 		fp = (struct fsinfo *)bp->b_data;
676 		if (!bcmp(fp->fsisig1, "RRaA", 4)
677 		    && !bcmp(fp->fsisig2, "rrAa", 4)
678 		    && !bcmp(fp->fsisig3, "\0\0\125\252", 4)
679 		    && !bcmp(fp->fsisig4, "\0\0\125\252", 4))
680 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
681 		else
682 			pmp->pm_fsinfo = 0;
683 		brelse(bp);
684 		bp = NULL;
685 	}
686 
687 	/*
688 	 * Check and validate (or perhaps invalidate?) the fsinfo structure?		XXX
689 	 */
690 
691 	/*
692 	 * Allocate memory for the bitmap of allocated clusters, and then
693 	 * fill it in.
694 	 */
695 	pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
696 				   / N_INUSEBITS)
697 				  * sizeof(*pmp->pm_inusemap),
698 				  M_MSDOSFSFAT, M_WAITOK);
699 
700 	/*
701 	 * fillinusemap() needs pm_devvp.
702 	 */
703 	pmp->pm_dev = dev;
704 	pmp->pm_devvp = devvp;
705 
706 	/*
707 	 * Have the inuse map filled in.
708 	 */
709 	if ((error = fillinusemap(pmp)) != 0)
710 		goto error_exit;
711 
712 	/*
713 	 * If they want fat updates to be synchronous then let them suffer
714 	 * the performance degradation in exchange for the on disk copy of
715 	 * the fat being correct just about all the time.  I suppose this
716 	 * would be a good thing to turn on if the kernel is still flakey.
717 	 */
718 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
719 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
720 
721 	/*
722 	 * Finish up.
723 	 */
724 	if (ronly)
725 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
726 	else
727 		pmp->pm_fmod = 1;
728 	mp->mnt_data = (qaddr_t) pmp;
729 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
730 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
731 	mp->mnt_flag |= MNT_LOCAL;
732 	devvp->v_specmountpoint = mp;
733 
734 	return 0;
735 
736 error_exit:
737 	if (bp)
738 		brelse(bp);
739 	(void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE, NOCRED, p);
740 	if (pmp) {
741 		if (pmp->pm_inusemap)
742 			free(pmp->pm_inusemap, M_MSDOSFSFAT);
743 		free(pmp, M_MSDOSFSMNT);
744 		mp->mnt_data = (qaddr_t)0;
745 	}
746 	return (error);
747 }
748 
749 /*
750  * Unmount the filesystem described by mp.
751  */
752 static int
753 msdosfs_unmount(mp, mntflags, p)
754 	struct mount *mp;
755 	int mntflags;
756 	struct proc *p;
757 {
758 	struct msdosfsmount *pmp;
759 	int error, flags;
760 
761 	flags = 0;
762 	if (mntflags & MNT_FORCE)
763 		flags |= FORCECLOSE;
764 	error = vflush(mp, NULLVP, flags);
765 	if (error)
766 		return error;
767 	pmp = VFSTOMSDOSFS(mp);
768 	pmp->pm_devvp->v_specmountpoint = NULL;
769 #ifdef MSDOSFS_DEBUG
770 	{
771 		struct vnode *vp = pmp->pm_devvp;
772 
773 		printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
774 		printf("flag %08lx, usecount %d, writecount %d, holdcnt %ld\n",
775 		    vp->v_flag, vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
776 		printf("id %lu, mount %p, op %p\n",
777 		    vp->v_id, vp->v_mount, vp->v_op);
778 		printf("freef %p, freeb %p, mount %p\n",
779 		    vp->v_freelist.tqe_next, vp->v_freelist.tqe_prev,
780 		    vp->v_mount);
781 		printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n",
782 		    TAILQ_FIRST(&vp->v_cleanblkhd),
783 		    TAILQ_FIRST(&vp->v_dirtyblkhd),
784 		    vp->v_numoutput, vp->v_type);
785 		printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
786 		    vp->v_socket, vp->v_tag,
787 		    ((u_int *)vp->v_data)[0],
788 		    ((u_int *)vp->v_data)[1]);
789 	}
790 #endif
791 	error = VOP_CLOSE(pmp->pm_devvp,
792 		    (pmp->pm_flags&MSDOSFSMNT_RONLY) ? FREAD : FREAD | FWRITE,
793 		    NOCRED, p);
794 	vrele(pmp->pm_devvp);
795 	free(pmp->pm_inusemap, M_MSDOSFSFAT);
796 	free(pmp, M_MSDOSFSMNT);
797 	mp->mnt_data = (qaddr_t)0;
798 	mp->mnt_flag &= ~MNT_LOCAL;
799 	return (error);
800 }
801 
802 static int
803 msdosfs_root(mp, vpp)
804 	struct mount *mp;
805 	struct vnode **vpp;
806 {
807 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
808 	struct denode *ndep;
809 	int error;
810 
811 #ifdef MSDOSFS_DEBUG
812 	printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
813 #endif
814 	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
815 	if (error)
816 		return (error);
817 	*vpp = DETOV(ndep);
818 	return (0);
819 }
820 
821 static int
822 msdosfs_statfs(mp, sbp, p)
823 	struct mount *mp;
824 	struct statfs *sbp;
825 	struct proc *p;
826 {
827 	struct msdosfsmount *pmp;
828 
829 	pmp = VFSTOMSDOSFS(mp);
830 	sbp->f_bsize = pmp->pm_bpcluster;
831 	sbp->f_iosize = pmp->pm_bpcluster;
832 	sbp->f_blocks = pmp->pm_nmbrofclusters;
833 	sbp->f_bfree = pmp->pm_freeclustercount;
834 	sbp->f_bavail = pmp->pm_freeclustercount;
835 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
836 	sbp->f_ffree = 0;	/* what to put in here? */
837 	if (sbp != &mp->mnt_stat) {
838 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
839 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
840 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
841 	}
842 	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
843 	return (0);
844 }
845 
846 static int
847 msdosfs_sync(mp, waitfor, cred, p)
848 	struct mount *mp;
849 	int waitfor;
850 	struct ucred *cred;
851 	struct proc *p;
852 {
853 	struct vnode *vp, *nvp;
854 	struct denode *dep;
855 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
856 	int error, allerror = 0;
857 
858 	/*
859 	 * If we ever switch to not updating all of the fats all the time,
860 	 * this would be the place to update them from the first one.
861 	 */
862 	if (pmp->pm_fmod != 0) {
863 		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
864 			panic("msdosfs_sync: rofs mod");
865 		else {
866 			/* update fats here */
867 		}
868 	}
869 	/*
870 	 * Write back each (modified) denode.
871 	 */
872 	simple_lock(&mntvnode_slock);
873 loop:
874 	for (vp = mp->mnt_vnodelist.lh_first; vp != NULL; vp = nvp) {
875 		/*
876 		 * If the vnode that we are about to sync is no longer
877 		 * associated with this mount point, start over.
878 		 */
879 		if (vp->v_mount != mp)
880 			goto loop;
881 
882 		simple_lock(&vp->v_interlock);
883 		nvp = vp->v_mntvnodes.le_next;
884 		dep = VTODE(vp);
885 		if (vp->v_type == VNON ||
886 		    ((dep->de_flag &
887 		    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
888 		    (TAILQ_EMPTY(&vp->v_dirtyblkhd) || waitfor == MNT_LAZY))) {
889 			simple_unlock(&vp->v_interlock);
890 			continue;
891 		}
892 		simple_unlock(&mntvnode_slock);
893 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, p);
894 		if (error) {
895 			simple_lock(&mntvnode_slock);
896 			if (error == ENOENT)
897 				goto loop;
898 			continue;
899 		}
900 		error = VOP_FSYNC(vp, cred, waitfor, p);
901 		if (error)
902 			allerror = error;
903 		VOP_UNLOCK(vp, 0, p);
904 		vrele(vp);
905 		simple_lock(&mntvnode_slock);
906 	}
907 	simple_unlock(&mntvnode_slock);
908 
909 	/*
910 	 * Flush filesystem control info.
911 	 */
912 	if (waitfor != MNT_LAZY) {
913 		vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY, p);
914 		error = VOP_FSYNC(pmp->pm_devvp, cred, waitfor, p);
915 		if (error)
916 			allerror = error;
917 		VOP_UNLOCK(pmp->pm_devvp, 0, p);
918 	}
919 	return (allerror);
920 }
921 
922 static int
923 msdosfs_fhtovp(mp, fhp, vpp)
924 	struct mount *mp;
925 	struct fid *fhp;
926 	struct vnode **vpp;
927 {
928 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
929 	struct defid *defhp = (struct defid *) fhp;
930 	struct denode *dep;
931 	int error;
932 
933 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
934 	if (error) {
935 		*vpp = NULLVP;
936 		return (error);
937 	}
938 	*vpp = DETOV(dep);
939 	return (0);
940 }
941 
942 static int
943 msdosfs_checkexp(mp, nam,  exflagsp, credanonp)
944 	struct mount *mp;
945 	struct sockaddr *nam;
946 	int *exflagsp;
947 	struct ucred **credanonp;
948 {
949 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
950 	struct netcred *np;
951 
952 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
953 	if (np == NULL)
954 		return (EACCES);
955 	*exflagsp = np->netc_exflags;
956 	*credanonp = &np->netc_anon;
957 	return (0);
958 }
959 
960 static int
961 msdosfs_vptofh(vp, fhp)
962 	struct vnode *vp;
963 	struct fid *fhp;
964 {
965 	struct denode *dep;
966 	struct defid *defhp;
967 
968 	dep = VTODE(vp);
969 	defhp = (struct defid *)fhp;
970 	defhp->defid_len = sizeof(struct defid);
971 	defhp->defid_dirclust = dep->de_dirclust;
972 	defhp->defid_dirofs = dep->de_diroffset;
973 	/* defhp->defid_gen = dep->de_gen; */
974 	return (0);
975 }
976 
977 static struct vfsops msdosfs_vfsops = {
978 	msdosfs_mount,
979 	vfs_stdstart,
980 	msdosfs_unmount,
981 	msdosfs_root,
982 	vfs_stdquotactl,
983 	msdosfs_statfs,
984 	msdosfs_sync,
985 	vfs_stdvget,
986 	msdosfs_fhtovp,
987 	msdosfs_checkexp,
988 	msdosfs_vptofh,
989 	msdosfs_init,
990 	vfs_stduninit,
991 	vfs_stdextattrctl,
992 };
993 
994 VFS_SET(msdosfs_vfsops, msdos, 0);
995