xref: /dragonfly/sys/vfs/msdosfs/msdosfs_vfsops.c (revision af79c6e5)
1 /* $FreeBSD: src/sys/msdosfs/msdosfs_vfsops.c,v 1.60.2.6 2002/09/12 21:33:38 trhodes Exp $ */
2 /* $DragonFly: src/sys/vfs/msdosfs/msdosfs_vfsops.c,v 1.9 2003/09/23 05:03:52 dillon Exp $ */
3 /*	$NetBSD: msdosfs_vfsops.c,v 1.51 1997/11/17 15:36:58 ws Exp $	*/
4 
5 /*-
6  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
7  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
8  * All rights reserved.
9  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by TooLs GmbH.
22  * 4. The name of TooLs GmbH may not be used to endorse or promote products
23  *    derived from this software without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
26  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
31  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
32  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
33  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
34  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 /*
37  * Written by Paul Popelka (paulp@uts.amdahl.com)
38  *
39  * You can do anything you want with this software, just don't say you wrote
40  * it, and don't remove this notice.
41  *
42  * This software is provided "as is".
43  *
44  * The author supplies this software to be publicly redistributed on the
45  * understanding that the author is not responsible for the correct
46  * functioning of this software in any circumstances and is not liable for
47  * any damages caused by this software.
48  *
49  * October 1992
50  */
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/conf.h>
55 #include <sys/proc.h>
56 #include <sys/namei.h>
57 #include <sys/kernel.h>
58 #include <sys/vnode.h>
59 #include <sys/mount.h>
60 #include <sys/buf.h>
61 #include <sys/fcntl.h>
62 #include <sys/malloc.h>
63 #include <sys/stat.h> 				/* defines ALLPERMS */
64 #include <vm/vm_zone.h>
65 
66 #include "bpb.h"
67 #include "bootsect.h"
68 #include "direntry.h"
69 #include "denode.h"
70 #include "msdosfsmount.h"
71 #include "fat.h"
72 
73 #define MSDOSFS_DFLTBSIZE       4096
74 
75 #if 1 /*def PC98*/
76 /*
77  * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
78  *       garbage or a random value :-{
79  *       If you want to use that broken-signatured media, define the
80  *       following symbol even though PC/AT.
81  *       (ex. mount PC-98 DOS formatted FD on PC/AT)
82  */
83 #define	MSDOSFS_NOCHECKSIG
84 #endif
85 
86 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
87 static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
88 
89 static int	update_mp (struct mount *mp, struct msdosfs_args *argp);
90 static int	mountmsdosfs (struct vnode *devvp, struct mount *mp,
91 				  struct thread *td, struct msdosfs_args *argp);
92 static int	msdosfs_fhtovp (struct mount *, struct fid *,
93 				    struct vnode **);
94 static int	msdosfs_checkexp (struct mount *, struct sockaddr *,
95 				    int *, struct ucred **);
96 static int	msdosfs_mount (struct mount *, char *, caddr_t,
97 				   struct nameidata *, struct thread *);
98 static int	msdosfs_root (struct mount *, struct vnode **);
99 static int	msdosfs_statfs (struct mount *, struct statfs *,
100 				    struct thread *);
101 static int	msdosfs_sync (struct mount *, int, struct thread *);
102 static int	msdosfs_unmount (struct mount *, int, struct thread *);
103 static int	msdosfs_vptofh (struct vnode *, struct fid *);
104 
105 static int
106 update_mp(mp, argp)
107 	struct mount *mp;
108 	struct msdosfs_args *argp;
109 {
110 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
111 	int error;
112 
113 	pmp->pm_gid = argp->gid;
114 	pmp->pm_uid = argp->uid;
115 	pmp->pm_mask = argp->mask & ALLPERMS;
116 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
117 	if (pmp->pm_flags & MSDOSFSMNT_U2WTABLE) {
118 		bcopy(argp->u2w, pmp->pm_u2w, sizeof(pmp->pm_u2w));
119 		bcopy(argp->d2u, pmp->pm_d2u, sizeof(pmp->pm_d2u));
120 		bcopy(argp->u2d, pmp->pm_u2d, sizeof(pmp->pm_u2d));
121 	}
122 	if (pmp->pm_flags & MSDOSFSMNT_ULTABLE) {
123 		bcopy(argp->ul, pmp->pm_ul, sizeof(pmp->pm_ul));
124 		bcopy(argp->lu, pmp->pm_lu, sizeof(pmp->pm_lu));
125 	}
126 
127 #ifndef __FreeBSD__
128 	/*
129 	 * GEMDOS knows nothing (yet) about win95
130 	 */
131 	if (pmp->pm_flags & MSDOSFSMNT_GEMDOSFS)
132 		pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
133 #endif
134 
135 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
136 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
137 	else if (!(pmp->pm_flags &
138 	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
139 		struct vnode *rootvp;
140 
141 		/*
142 		 * Try to divine whether to support Win'95 long filenames
143 		 */
144 		if (FAT32(pmp))
145 			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
146 		else {
147 			if ((error = msdosfs_root(mp, &rootvp)) != 0)
148 				return error;
149 			pmp->pm_flags |= findwin95(VTODE(rootvp))
150 				? MSDOSFSMNT_LONGNAME
151 					: MSDOSFSMNT_SHORTNAME;
152 			vput(rootvp);
153 		}
154 	}
155 	return 0;
156 }
157 
158 #ifndef __FreeBSD__
159 int
160 msdosfs_mountroot()
161 {
162 	struct mount *mp;
163 	struct thread *td = curthread;	/* XXX */
164 	size_t size;
165 	int error;
166 	struct msdosfs_args args;
167 
168 	if (root_device->dv_class != DV_DISK)
169 		return (ENODEV);
170 
171 	/*
172 	 * Get vnodes for swapdev and rootdev.
173 	 */
174 	if (bdevvp(rootdev, &rootvp))
175 		panic("msdosfs_mountroot: can't setup rootvp");
176 
177 	mp = malloc((u_long)sizeof(struct mount), M_MOUNT, M_WAITOK);
178 	bzero((char *)mp, (u_long)sizeof(struct mount));
179 	mp->mnt_op = &msdosfs_vfsops;
180 	mp->mnt_flag = 0;
181 	TAILQ_INIT(&mp->mnt_nvnodelist);
182 	TAILQ_INIT(&mp->mnt_reservedvnlist);
183 
184 	args.flags = 0;
185 	args.uid = 0;
186 	args.gid = 0;
187 	args.mask = 0777;
188 
189 	if ((error = mountmsdosfs(rootvp, mp, p, &args)) != 0) {
190 		free(mp, M_MOUNT);
191 		return (error);
192 	}
193 
194 	if ((error = update_mp(mp, &args)) != 0) {
195 		(void)msdosfs_unmount(mp, 0, p);
196 		free(mp, M_MOUNT);
197 		return (error);
198 	}
199 
200 	if ((error = vfs_lock(mp)) != 0) {
201 		(void)msdosfs_unmount(mp, 0, p);
202 		free(mp, M_MOUNT);
203 		return (error);
204 	}
205 
206 	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
207 	mp->mnt_vnodecovered = NULLVP;
208 	(void) copystr("/", mp->mnt_stat.f_mntonname, MNAMELEN - 1,
209 	    &size);
210 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
211 	(void) copystr(ROOTNAME, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
212 	    &size);
213 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
214 	(void)msdosfs_statfs(mp, &mp->mnt_stat, p);
215 	vfs_unlock(mp);
216 	return (0);
217 }
218 #endif
219 
220 /*
221  * mp - path - addr in user space of mount point (ie /usr or whatever)
222  * data - addr in user space of mount params including the name of the block
223  * special file to treat as a filesystem.
224  */
225 static int
226 msdosfs_mount(mp, path, data, ndp, td)
227 	struct mount *mp;
228 	char *path;
229 	caddr_t data;
230 	struct nameidata *ndp;
231 	struct thread *td;
232 {
233 	struct vnode *devvp;	  /* vnode for blk device to mount */
234 	struct msdosfs_args args; /* will hold data from mount request */
235 	/* msdosfs specific mount control block */
236 	struct msdosfsmount *pmp = NULL;
237 	size_t size;
238 	int error, flags;
239 	mode_t accessmode;
240 	struct proc *p = td->td_proc;
241 
242 	KKASSERT(p);
243 
244 	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
245 	if (error)
246 		return (error);
247 	if (args.magic != MSDOSFS_ARGSMAGIC)
248 		args.flags = 0;
249 	/*
250 	 * If updating, check whether changing from read-only to
251 	 * read/write; if there is no device name, that's all we do.
252 	 */
253 	if (mp->mnt_flag & MNT_UPDATE) {
254 		pmp = VFSTOMSDOSFS(mp);
255 		error = 0;
256 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
257 			flags = WRITECLOSE;
258 			if (mp->mnt_flag & MNT_FORCE)
259 				flags |= FORCECLOSE;
260 			error = vflush(mp, 0, flags);
261 		}
262 		if (!error && (mp->mnt_flag & MNT_RELOAD))
263 			/* not yet implemented */
264 			error = EOPNOTSUPP;
265 		if (error)
266 			return (error);
267 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
268 			/*
269 			 * If upgrade to read-write by non-root, then verify
270 			 * that user has necessary permissions on the device.
271 			 */
272 			if (p->p_ucred->cr_uid != 0) {
273 				devvp = pmp->pm_devvp;
274 				vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
275 				error = VOP_ACCESS(devvp, VREAD | VWRITE,
276 						   p->p_ucred, td);
277 				if (error) {
278 					VOP_UNLOCK(devvp, 0, td);
279 					return (error);
280 				}
281 				VOP_UNLOCK(devvp, 0, td);
282 			}
283 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
284 		}
285 		if (args.fspec == 0) {
286 #ifdef	__notyet__		/* doesn't work correctly with current mountd	XXX */
287 			if (args.flags & MSDOSFSMNT_MNTOPT) {
288 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
289 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
290 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
291 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
292 			}
293 #endif
294 			/*
295 			 * Process export requests.
296 			 */
297 			return (vfs_export(mp, &pmp->pm_export, &args.export));
298 		}
299 	}
300 	/*
301 	 * Not an update, or updating the name: look up the name
302 	 * and verify that it refers to a sensible block device.
303 	 */
304 	NDINIT(ndp, NAMEI_LOOKUP, CNP_FOLLOW, UIO_USERSPACE, args.fspec, td);
305 	error = namei(ndp);
306 	if (error)
307 		return (error);
308 	devvp = ndp->ni_vp;
309 	NDFREE(ndp, NDF_ONLY_PNBUF);
310 
311 	if (!vn_isdisk(devvp, &error)) {
312 		vrele(devvp);
313 		return (error);
314 	}
315 	/*
316 	 * If mount by non-root, then verify that user has necessary
317 	 * permissions on the device.
318 	 */
319 	if (p->p_ucred->cr_uid != 0) {
320 		accessmode = VREAD;
321 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
322 			accessmode |= VWRITE;
323 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
324 		error = VOP_ACCESS(devvp, accessmode, p->p_ucred, td);
325 		if (error) {
326 			vput(devvp);
327 			return (error);
328 		}
329 		VOP_UNLOCK(devvp, 0, td);
330 	}
331 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
332 		error = mountmsdosfs(devvp, mp, td, &args);
333 #ifdef MSDOSFS_DEBUG		/* only needed for the printf below */
334 		pmp = VFSTOMSDOSFS(mp);
335 #endif
336 	} else {
337 		if (devvp != pmp->pm_devvp)
338 			error = EINVAL;	/* XXX needs translation */
339 		else
340 			vrele(devvp);
341 	}
342 	if (error) {
343 		vrele(devvp);
344 		return (error);
345 	}
346 
347 	error = update_mp(mp, &args);
348 	if (error) {
349 		msdosfs_unmount(mp, MNT_FORCE, td);
350 		return error;
351 	}
352 
353 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
354 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
355 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
356 	    &size);
357 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
358 	(void) msdosfs_statfs(mp, &mp->mnt_stat, td);
359 #ifdef MSDOSFS_DEBUG
360 	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
361 #endif
362 	return (0);
363 }
364 
365 static int
366 mountmsdosfs(devvp, mp, td, argp)
367 	struct vnode *devvp;
368 	struct mount *mp;
369 	struct thread *td;
370 	struct msdosfs_args *argp;
371 {
372 	struct msdosfsmount *pmp;
373 	struct buf *bp;
374 	dev_t dev = devvp->v_rdev;
375 #ifndef __FreeBSD__
376 	struct partinfo dpart;
377 	int bsize = 0, dtype = 0, tmp;
378 #endif
379 	union bootsector *bsp;
380 	struct byte_bpb33 *b33;
381 	struct byte_bpb50 *b50;
382 	struct byte_bpb710 *b710;
383 	u_int8_t SecPerClust;
384 	u_long clusters;
385 	int	ronly, error;
386 
387 	/*
388 	 * Disallow multiple mounts of the same device.
389 	 * Disallow mounting of a device that is currently in use
390 	 * (except for root, which might share swap device for miniroot).
391 	 * Flush out any old buffers remaining from a previous use.
392 	 */
393 	error = vfs_mountedon(devvp);
394 	if (error)
395 		return (error);
396 	if (vcount(devvp) > 1 && devvp != rootvp)
397 		return (EBUSY);
398 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
399 	error = vinvalbuf(devvp, V_SAVE, td, 0, 0);
400 	VOP_UNLOCK(devvp, 0, td);
401 	if (error)
402 		return (error);
403 
404 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
405 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
406 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, td);
407 	VOP_UNLOCK(devvp, 0, td);
408 	if (error)
409 		return (error);
410 
411 	bp  = NULL; /* both used in error_exit */
412 	pmp = NULL;
413 
414 #ifndef __FreeBSD__
415 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
416 		/*
417 	 	 * We need the disklabel to calculate the size of a FAT entry
418 		 * later on. Also make sure the partition contains a filesystem
419 		 * of type FS_MSDOS. This doesn't work for floppies, so we have
420 		 * to check for them too.
421 	 	 *
422 	 	 * At least some parts of the msdos fs driver seem to assume
423 		 * that the size of a disk block will always be 512 bytes.
424 		 * Let's check it...
425 		 */
426 		error = VOP_IOCTL(devvp, DIOCGPART, (caddr_t)&dpart, FREAD, td);
427 		if (error)
428 			goto error_exit;
429 		tmp   = dpart.part->p_fstype;
430 		dtype = dpart.disklab->d_type;
431 		bsize = dpart.disklab->d_secsize;
432 		if (bsize != 512 || (dtype!=DTYPE_FLOPPY && tmp!=FS_MSDOS)) {
433 			error = EINVAL;
434 			goto error_exit;
435 		}
436 	}
437 #endif
438 
439 	/*
440 	 * Read the boot sector of the filesystem, and then check the
441 	 * boot signature.  If not a dos boot sector then error out.
442 	 *
443 	 * NOTE: 2048 is a maximum sector size in current...
444 	 */
445 	error = bread(devvp, 0, 2048, &bp);
446 	if (error)
447 		goto error_exit;
448 	bp->b_flags |= B_AGE;
449 	bsp = (union bootsector *)bp->b_data;
450 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
451 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
452 	b710 = (struct byte_bpb710 *)bsp->bs710.bsPBP;
453 
454 #ifndef __FreeBSD__
455 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
456 #endif
457 #ifndef MSDOSFS_NOCHECKSIG
458 		if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
459 		    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
460 			error = EINVAL;
461 			goto error_exit;
462 		}
463 #endif
464 #ifndef __FreeBSD__
465 	}
466 #endif
467 
468 	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK);
469 	bzero((caddr_t)pmp, sizeof *pmp);
470 	pmp->pm_mountp = mp;
471 
472 	/*
473 	 * Compute several useful quantities from the bpb in the
474 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
475 	 * the fields that are different between dos 5 and dos 3.3.
476 	 */
477 	SecPerClust = b50->bpbSecPerClust;
478 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
479 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
480 	pmp->pm_FATs = b50->bpbFATs;
481 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
482 	pmp->pm_Sectors = getushort(b50->bpbSectors);
483 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
484 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
485 	pmp->pm_Heads = getushort(b50->bpbHeads);
486 	pmp->pm_Media = b50->bpbMedia;
487 
488 	/* calculate the ratio of sector size to DEV_BSIZE */
489 	pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
490 
491 #ifndef __FreeBSD__
492 	if (!(argp->flags & MSDOSFSMNT_GEMDOSFS)) {
493 #endif
494 		/* XXX - We should probably check more values here */
495 		if (!pmp->pm_BytesPerSec || !SecPerClust
496 			|| !pmp->pm_Heads || pmp->pm_Heads > 255
497 #ifdef PC98
498 	    		|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 255) {
499 #else
500 			|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 63) {
501 #endif
502 			error = EINVAL;
503 			goto error_exit;
504 		}
505 #ifndef __FreeBSD__
506 	}
507 #endif
508 
509 	if (pmp->pm_Sectors == 0) {
510 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
511 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
512 	} else {
513 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
514 		pmp->pm_HugeSectors = pmp->pm_Sectors;
515 	}
516 	if (pmp->pm_HugeSectors > 0xffffffff /
517 	    (pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) {
518 		/*
519 		 * We cannot deal currently with this size of disk
520 		 * due to fileid limitations (see msdosfs_getattr and
521 		 * msdosfs_readdir)
522 		 */
523 		error = EINVAL;
524 		printf("mountmsdosfs(): disk too big, sorry\n");
525 		goto error_exit;
526 	}
527 
528 	if (pmp->pm_RootDirEnts == 0) {
529 		if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
530 		    || bsp->bs710.bsBootSectSig3 != BOOTSIG3
531 		    || pmp->pm_Sectors
532 		    || pmp->pm_FATsecs
533 		    || getushort(b710->bpbFSVers)) {
534 			error = EINVAL;
535 			printf("mountmsdosfs(): bad FAT32 filesystem\n");
536 			goto error_exit;
537 		}
538 		pmp->pm_fatmask = FAT32_MASK;
539 		pmp->pm_fatmult = 4;
540 		pmp->pm_fatdiv = 1;
541 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
542 		if (getushort(b710->bpbExtFlags) & FATMIRROR)
543 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
544 		else
545 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
546 	} else
547 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
548 
549 	/*
550 	 * Check a few values (could do some more):
551 	 * - logical sector size: power of 2, >= block size
552 	 * - sectors per cluster: power of 2, >= 1
553 	 * - number of sectors:   >= 1, <= size of partition
554 	 */
555 	if ( (SecPerClust == 0)
556 	  || (SecPerClust & (SecPerClust - 1))
557 	  || (pmp->pm_BytesPerSec < DEV_BSIZE)
558 	  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
559 	  || (pmp->pm_HugeSectors == 0)
560 	) {
561 		error = EINVAL;
562 		goto error_exit;
563 	}
564 
565 	pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
566 	pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
567 	pmp->pm_FATsecs     *= pmp->pm_BlkPerSec;
568 	SecPerClust         *= pmp->pm_BlkPerSec;
569 
570 	pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
571 
572 	if (FAT32(pmp)) {
573 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
574 		pmp->pm_firstcluster = pmp->pm_fatblk
575 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
576 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
577 	} else {
578 		pmp->pm_rootdirblk = pmp->pm_fatblk +
579 			(pmp->pm_FATs * pmp->pm_FATsecs);
580 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
581 				       + DEV_BSIZE - 1)
582 			/ DEV_BSIZE; /* in blocks */
583 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
584 	}
585 
586 	pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
587 	    SecPerClust + 1;
588 	pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */
589 
590 #ifndef __FreeBSD__
591 	if (argp->flags & MSDOSFSMNT_GEMDOSFS) {
592 		if ((pmp->pm_maxcluster <= (0xff0 - 2))
593 		      && ((dtype == DTYPE_FLOPPY) || ((dtype == DTYPE_VNODE)
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
605 #endif
606 	if (pmp->pm_fatmask == 0) {
607 		if (pmp->pm_maxcluster
608 		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
609 			/*
610 			 * This will usually be a floppy disk. This size makes
611 			 * sure that one fat entry will not be split across
612 			 * multiple blocks.
613 			 */
614 			pmp->pm_fatmask = FAT12_MASK;
615 			pmp->pm_fatmult = 3;
616 			pmp->pm_fatdiv = 2;
617 		} else {
618 			pmp->pm_fatmask = FAT16_MASK;
619 			pmp->pm_fatmult = 2;
620 			pmp->pm_fatdiv = 1;
621 		}
622 	}
623 
624 	clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
625 	if (pmp->pm_maxcluster >= clusters) {
626 		printf("Warning: number of clusters (%ld) exceeds FAT "
627 		    "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
628 		pmp->pm_maxcluster = clusters - 1;
629 	}
630 
631 
632 	if (FAT12(pmp))
633 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
634 	else
635 		pmp->pm_fatblocksize = MSDOSFS_DFLTBSIZE;
636 
637 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
638 	pmp->pm_bnshift = ffs(DEV_BSIZE) - 1;
639 
640 	/*
641 	 * Compute mask and shift value for isolating cluster relative byte
642 	 * offsets and cluster numbers from a file offset.
643 	 */
644 	pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
645 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
646 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
647 
648 	/*
649 	 * Check for valid cluster size
650 	 * must be a power of 2
651 	 */
652 	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
653 		error = EINVAL;
654 		goto error_exit;
655 	}
656 
657 	/*
658 	 * Release the bootsector buffer.
659 	 */
660 	brelse(bp);
661 	bp = NULL;
662 
663 	/*
664 	 * Check FSInfo.
665 	 */
666 	if (pmp->pm_fsinfo) {
667 		struct fsinfo *fp;
668 
669 		if ((error = bread(devvp, pmp->pm_fsinfo, fsi_size(pmp), &bp)) != 0)
670 			goto error_exit;
671 		fp = (struct fsinfo *)bp->b_data;
672 		if (!bcmp(fp->fsisig1, "RRaA", 4)
673 		    && !bcmp(fp->fsisig2, "rrAa", 4)
674 		    && !bcmp(fp->fsisig3, "\0\0\125\252", 4)
675 		    && !bcmp(fp->fsisig4, "\0\0\125\252", 4))
676 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
677 		else
678 			pmp->pm_fsinfo = 0;
679 		brelse(bp);
680 		bp = NULL;
681 	}
682 
683 	/*
684 	 * Check and validate (or perhaps invalidate?) the fsinfo structure?
685 	 */
686 	if (pmp->pm_fsinfo && pmp->pm_nxtfree > pmp->pm_maxcluster) {
687 		printf(
688 		"Next free cluster in FSInfo (%lu) exceeds maxcluster (%lu)\n",
689 		    pmp->pm_nxtfree, pmp->pm_maxcluster);
690 		error = EINVAL;
691 		goto error_exit;
692 	}
693 
694 	/*
695 	 * Allocate memory for the bitmap of allocated clusters, and then
696 	 * fill it in.
697 	 */
698 	pmp->pm_inusemap = malloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
699 				   / N_INUSEBITS)
700 				  * sizeof(*pmp->pm_inusemap),
701 				  M_MSDOSFSFAT, M_WAITOK);
702 
703 	/*
704 	 * fillinusemap() needs pm_devvp.
705 	 */
706 	pmp->pm_dev = dev;
707 	pmp->pm_devvp = devvp;
708 
709 	/*
710 	 * Have the inuse map filled in.
711 	 */
712 	if ((error = fillinusemap(pmp)) != 0)
713 		goto error_exit;
714 
715 	/*
716 	 * If they want fat updates to be synchronous then let them suffer
717 	 * the performance degradation in exchange for the on disk copy of
718 	 * the fat being correct just about all the time.  I suppose this
719 	 * would be a good thing to turn on if the kernel is still flakey.
720 	 */
721 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
722 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
723 
724 	/*
725 	 * Finish up.
726 	 */
727 	if (ronly)
728 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
729 	else
730 		pmp->pm_fmod = 1;
731 	mp->mnt_data = (qaddr_t) pmp;
732 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
733 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
734 	mp->mnt_flag |= MNT_LOCAL;
735 	devvp->v_specmountpoint = mp;
736 
737 	return 0;
738 
739 error_exit:
740 	if (bp)
741 		brelse(bp);
742 	(void) VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE, td);
743 	if (pmp) {
744 		if (pmp->pm_inusemap)
745 			free(pmp->pm_inusemap, M_MSDOSFSFAT);
746 		free(pmp, M_MSDOSFSMNT);
747 		mp->mnt_data = (qaddr_t)0;
748 	}
749 	return (error);
750 }
751 
752 /*
753  * Unmount the filesystem described by mp.
754  */
755 static int
756 msdosfs_unmount(mp, mntflags, td)
757 	struct mount *mp;
758 	int mntflags;
759 	struct thread *td;
760 {
761 	struct msdosfsmount *pmp;
762 	int error, flags;
763 
764 	flags = 0;
765 	if (mntflags & MNT_FORCE)
766 		flags |= FORCECLOSE;
767 	error = vflush(mp, 0, flags);
768 	if (error)
769 		return error;
770 	pmp = VFSTOMSDOSFS(mp);
771 	pmp->pm_devvp->v_specmountpoint = NULL;
772 #ifdef MSDOSFS_DEBUG
773 	{
774 		struct vnode *vp = pmp->pm_devvp;
775 
776 		printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
777 		printf("flag %08lx, usecount %d, writecount %d, holdcnt %ld\n",
778 		    vp->v_flag, vp->v_usecount, vp->v_writecount, vp->v_holdcnt);
779 		printf("id %lu, mount %p, op %p\n",
780 		    vp->v_id, vp->v_mount, vp->v_op);
781 		printf("freef %p, freeb %p, mount %p\n",
782 		    vp->v_freelist.tqe_next, vp->v_freelist.tqe_prev,
783 		    vp->v_mount);
784 		printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n",
785 		    TAILQ_FIRST(&vp->v_cleanblkhd),
786 		    TAILQ_FIRST(&vp->v_dirtyblkhd),
787 		    vp->v_numoutput, vp->v_type);
788 		printf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
789 		    vp->v_socket, vp->v_tag,
790 		    ((u_int *)vp->v_data)[0],
791 		    ((u_int *)vp->v_data)[1]);
792 	}
793 #endif
794 	error = VOP_CLOSE(pmp->pm_devvp,
795 		    (pmp->pm_flags&MSDOSFSMNT_RONLY) ? FREAD : FREAD | FWRITE,
796 		    td);
797 	vrele(pmp->pm_devvp);
798 	free(pmp->pm_inusemap, M_MSDOSFSFAT);
799 	free(pmp, M_MSDOSFSMNT);
800 	mp->mnt_data = (qaddr_t)0;
801 	mp->mnt_flag &= ~MNT_LOCAL;
802 	return (error);
803 }
804 
805 static int
806 msdosfs_root(mp, vpp)
807 	struct mount *mp;
808 	struct vnode **vpp;
809 {
810 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
811 	struct denode *ndep;
812 	int error;
813 
814 #ifdef MSDOSFS_DEBUG
815 	printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
816 #endif
817 	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
818 	if (error)
819 		return (error);
820 	*vpp = DETOV(ndep);
821 	return (0);
822 }
823 
824 static int
825 msdosfs_statfs(mp, sbp, td)
826 	struct mount *mp;
827 	struct statfs *sbp;
828 	struct thread *td;
829 {
830 	struct msdosfsmount *pmp;
831 
832 	pmp = VFSTOMSDOSFS(mp);
833 	sbp->f_bsize = pmp->pm_bpcluster;
834 	sbp->f_iosize = pmp->pm_bpcluster;
835 	sbp->f_blocks = pmp->pm_maxcluster + 1;
836 	sbp->f_bfree = pmp->pm_freeclustercount;
837 	sbp->f_bavail = pmp->pm_freeclustercount;
838 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
839 	sbp->f_ffree = 0;	/* what to put in here? */
840 	if (sbp != &mp->mnt_stat) {
841 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
842 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
843 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
844 	}
845 	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
846 	return (0);
847 }
848 
849 static int
850 msdosfs_sync(mp, waitfor, td)
851 	struct mount *mp;
852 	int waitfor;
853 	struct thread *td;
854 {
855 	struct vnode *vp, *nvp;
856 	struct denode *dep;
857 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
858 	int error, allerror = 0;
859 	int gen;
860 
861 	/*
862 	 * If we ever switch to not updating all of the fats all the time,
863 	 * this would be the place to update them from the first one.
864 	 */
865 	if (pmp->pm_fmod != 0) {
866 		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
867 			panic("msdosfs_sync: rofs mod");
868 		else {
869 			/* update fats here */
870 		}
871 	}
872 	/*
873 	 * Write back each (modified) denode.
874 	 *
875 	 * YYY gen number handling needs more work.
876 	 */
877 	gen = lwkt_gettoken(&mntvnode_token);
878 loop:
879 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
880 		lwkt_gettoken(&vp->v_interlock);
881 		/*
882 		 * If the vnode that we are about to sync is no longer
883 		 * associated with this mount point, start over.  If
884 		 * we lost the mntvnode token, start over.
885 		 */
886 		if (vp->v_mount != mp) {
887 			lwkt_reltoken(&vp->v_interlock);
888 			goto loop;
889 		}
890 		if (lwkt_gentoken(&mntvnode_token, &gen) != 0) {
891 			lwkt_reltoken(&vp->v_interlock);
892 			goto loop;
893 		}
894 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
895 		dep = VTODE(vp);
896 		if (vp->v_type == VNON ||
897 		    ((dep->de_flag &
898 		    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
899 		    (TAILQ_EMPTY(&vp->v_dirtyblkhd) || waitfor == MNT_LAZY))) {
900 			lwkt_reltoken(&vp->v_interlock);
901 			continue;
902 		}
903 		lwkt_reltoken(&mntvnode_token);
904 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
905 		if (error) {
906 			lwkt_gettoken(&mntvnode_token);
907 			if (error == ENOENT)
908 				goto loop;
909 			continue;
910 		}
911 		error = VOP_FSYNC(vp, waitfor, td);
912 		if (error)
913 			allerror = error;
914 		VOP_UNLOCK(vp, 0, td);
915 		vrele(vp);
916 		lwkt_gettoken(&mntvnode_token);
917 	}
918 	lwkt_reltoken(&mntvnode_token);
919 
920 	/*
921 	 * Flush filesystem control info.
922 	 */
923 	if (waitfor != MNT_LAZY) {
924 		vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY, td);
925 		error = VOP_FSYNC(pmp->pm_devvp, waitfor, td);
926 		if (error)
927 			allerror = error;
928 		VOP_UNLOCK(pmp->pm_devvp, 0, td);
929 	}
930 	return (allerror);
931 }
932 
933 static int
934 msdosfs_fhtovp(mp, fhp, vpp)
935 	struct mount *mp;
936 	struct fid *fhp;
937 	struct vnode **vpp;
938 {
939 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
940 	struct defid *defhp = (struct defid *) fhp;
941 	struct denode *dep;
942 	int error;
943 
944 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
945 	if (error) {
946 		*vpp = NULLVP;
947 		return (error);
948 	}
949 	*vpp = DETOV(dep);
950 	return (0);
951 }
952 
953 static int
954 msdosfs_checkexp(mp, nam,  exflagsp, credanonp)
955 	struct mount *mp;
956 	struct sockaddr *nam;
957 	int *exflagsp;
958 	struct ucred **credanonp;
959 {
960 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
961 	struct netcred *np;
962 
963 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
964 	if (np == NULL)
965 		return (EACCES);
966 	*exflagsp = np->netc_exflags;
967 	*credanonp = &np->netc_anon;
968 	return (0);
969 }
970 
971 static int
972 msdosfs_vptofh(vp, fhp)
973 	struct vnode *vp;
974 	struct fid *fhp;
975 {
976 	struct denode *dep;
977 	struct defid *defhp;
978 
979 	dep = VTODE(vp);
980 	defhp = (struct defid *)fhp;
981 	defhp->defid_len = sizeof(struct defid);
982 	defhp->defid_dirclust = dep->de_dirclust;
983 	defhp->defid_dirofs = dep->de_diroffset;
984 	/* defhp->defid_gen = dep->de_gen; */
985 	return (0);
986 }
987 
988 static struct vfsops msdosfs_vfsops = {
989 	msdosfs_mount,
990 	vfs_stdstart,
991 	msdosfs_unmount,
992 	msdosfs_root,
993 	vfs_stdquotactl,
994 	msdosfs_statfs,
995 	msdosfs_sync,
996 	vfs_stdvget,
997 	msdosfs_fhtovp,
998 	msdosfs_checkexp,
999 	msdosfs_vptofh,
1000 	msdosfs_init,
1001 	msdosfs_uninit,
1002 	vfs_stdextattrctl,
1003 };
1004 
1005 VFS_SET(msdosfs_vfsops, msdos, 0);
1006