xref: /dragonfly/sys/vfs/msdosfs/msdosfs_vfsops.c (revision fb151170)
1 /* $FreeBSD: /usr/local/www/cvsroot/FreeBSD/src/sys/msdosfs/Attic/msdosfs_vfsops.c,v 1.60.2.8 2004/03/02 09:43:04 tjr Exp $ */
2 /* $DragonFly: src/sys/vfs/msdosfs/msdosfs_vfsops.c,v 1.52 2008/09/17 21:44:24 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/nlookup.h>
57 #include <sys/kernel.h>
58 #include <sys/vnode.h>
59 #include <sys/iconv.h>
60 #include <sys/mount.h>
61 #include <sys/buf.h>
62 #include <sys/fcntl.h>
63 #include <sys/malloc.h>
64 #include <sys/stat.h> 				/* defines ALLPERMS */
65 #include <vm/vm_zone.h>
66 
67 #include <sys/buf2.h>
68 
69 #include "bpb.h"
70 #include "bootsect.h"
71 #include "direntry.h"
72 #include "denode.h"
73 #include "msdosfsmount.h"
74 #include "fat.h"
75 
76 extern struct vop_ops msdosfs_vnode_vops;
77 struct iconv_functions *msdos_iconv;
78 
79 #define MSDOSFS_DFLTBSIZE       4096
80 #define ENCODING_UNICODE        "UTF-16BE"
81 #if 1 /*def PC98*/
82 /*
83  * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
84  *       garbage or a random value :-{
85  *       If you want to use that broken-signatured media, define the
86  *       following symbol even though PC/AT.
87  *       (ex. mount PC-98 DOS formatted FD on PC/AT)
88  */
89 #define	MSDOSFS_NOCHECKSIG
90 #endif
91 
92 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
93 static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
94 
95 static int	update_mp (struct mount *mp, struct msdosfs_args *argp);
96 static int	mountmsdosfs (struct vnode *devvp, struct mount *mp,
97 				  struct msdosfs_args *argp);
98 static int	msdosfs_fhtovp (struct mount *, struct vnode *,
99 				struct fid *, struct vnode **);
100 static int	msdosfs_checkexp (struct mount *, struct sockaddr *,
101 				    int *, struct ucred **);
102 static int	msdosfs_mount (struct mount *, char *, caddr_t,
103 				   struct ucred *);
104 static int	msdosfs_root (struct mount *, struct vnode **);
105 static int	msdosfs_statfs (struct mount *, struct statfs *,
106 				struct ucred *);
107 static int	msdosfs_sync (struct mount *, int);
108 static int	msdosfs_unmount (struct mount *, int);
109 static int	msdosfs_vptofh (struct vnode *, struct fid *);
110 
111 static int
112 update_mp(struct mount *mp, struct msdosfs_args *argp)
113 {
114 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
115 	int error;
116         char cs_local[ICONV_CSNMAXLEN];
117         char cs_dos[ICONV_CSNMAXLEN];
118 
119 	pmp->pm_gid = argp->gid;
120 	pmp->pm_uid = argp->uid;
121 	pmp->pm_mask = argp->mask & ALLPERMS;
122 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
123 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdos_iconv) {
124 		bcopy(argp->cs_local, cs_local, sizeof(cs_local));
125 		bcopy(argp->cs_dos, cs_dos, sizeof(cs_dos));
126 		kprintf("local: %s dos: %s\n",argp->cs_local, argp->cs_dos);
127 		error = msdos_iconv->open(cs_local, ENCODING_UNICODE, &pmp->pm_w2u);
128 		if(error)
129 			return error;
130 		error = msdos_iconv->open(ENCODING_UNICODE, cs_local, &pmp->pm_u2w);
131 		if(error)
132 			return error;
133 		error = msdos_iconv->open(cs_dos, cs_local, &pmp->pm_u2d);
134 		if(error)
135 			return error;
136 		error = msdos_iconv->open(cs_local, cs_dos, &pmp->pm_d2u);
137 		if(error)
138 			return error;
139 	}
140 
141 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
142 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
143 	else if (!(pmp->pm_flags &
144 	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
145 		struct vnode *rootvp;
146 
147 		/*
148 		 * Try to divine whether to support Win'95 long filenames
149 		 */
150 		if (FAT32(pmp))
151 			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
152 		else {
153 			if ((error = msdosfs_root(mp, &rootvp)) != 0)
154 				return error;
155 			pmp->pm_flags |= findwin95(VTODE(rootvp))
156 				? MSDOSFSMNT_LONGNAME
157 					: MSDOSFSMNT_SHORTNAME;
158 			vput(rootvp);
159 		}
160 	}
161 	return 0;
162 }
163 
164 /*
165  * mp - path - addr in user space of mount point (ie /usr or whatever)
166  * data - addr in user space of mount params including the name of the block
167  * special file to treat as a filesystem.
168  */
169 static int
170 msdosfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
171 {
172 	struct vnode *devvp;	  /* vnode for blk device to mount */
173 	struct msdosfs_args args; /* will hold data from mount request */
174 	/* msdosfs specific mount control block */
175 	struct msdosfsmount *pmp = NULL;
176 	size_t size;
177 	int error, flags;
178 	mode_t accessmode;
179 	struct nlookupdata nd;
180 
181 	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
182 	if (error)
183 		return (error);
184 	if (args.magic != MSDOSFS_ARGSMAGIC)
185 		args.flags = 0;
186 	/*
187 	 * If updating, check whether changing from read-only to
188 	 * read/write; if there is no device name, that's all we do.
189 	 */
190 	if (mp->mnt_flag & MNT_UPDATE) {
191 		pmp = VFSTOMSDOSFS(mp);
192 		error = 0;
193 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
194 			flags = WRITECLOSE;
195 			if (mp->mnt_flag & MNT_FORCE)
196 				flags |= FORCECLOSE;
197 			error = vflush(mp, 0, flags);
198 			if (error == 0) {
199 				devvp = pmp->pm_devvp;
200 				VOP_OPEN(devvp, FREAD, FSCRED, NULL);
201 				VOP_CLOSE(devvp, FREAD|FWRITE);
202 				pmp->pm_flags |= MSDOSFSMNT_RONLY;
203 			}
204 		}
205 		if (!error && (mp->mnt_flag & MNT_RELOAD))
206 			/* not yet implemented */
207 			error = EOPNOTSUPP;
208 		if (error)
209 			return (error);
210 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
211 			/*
212 			 * If upgrade to read-write by non-root, then verify
213 			 * that user has necessary permissions on the device.
214 			 */
215 			devvp = pmp->pm_devvp;
216 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
217 			if (cred->cr_uid != 0) {
218 				error = VOP_EACCESS(devvp, VREAD | VWRITE, cred);
219 				if (error) {
220 					vn_unlock(devvp);
221 					return (error);
222 				}
223 			}
224 			VOP_OPEN(devvp, FREAD|FWRITE, FSCRED, NULL);
225 			VOP_CLOSE(devvp, FREAD);
226 			vn_unlock(devvp);
227 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
228 		}
229 		if (args.fspec == 0) {
230 #ifdef	__notyet__		/* doesn't work correctly with current mountd	XXX */
231 			if (args.flags & MSDOSFSMNT_MNTOPT) {
232 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
233 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
234 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
235 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
236 			}
237 #endif
238 			/*
239 			 * Process export requests.
240 			 */
241 			return (vfs_export(mp, &pmp->pm_export, &args.export));
242 		}
243 	}
244 	/*
245 	 * Not an update, or updating the name: look up the name
246 	 * and verify that it refers to a sensible block device.
247 	 */
248 	devvp = NULL;
249 	error = nlookup_init(&nd, args.fspec, UIO_USERSPACE, NLC_FOLLOW);
250 	if (error == 0)
251 		error = nlookup(&nd);
252 	if (error == 0)
253 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
254 	nlookup_done(&nd);
255 	if (error)
256 		return (error);
257 
258 	if (!vn_isdisk(devvp, &error)) {
259 		vrele(devvp);
260 		return (error);
261 	}
262 	/*
263 	 * If mount by non-root, then verify that user has necessary
264 	 * permissions on the device.
265 	 */
266 	if (cred->cr_uid != 0) {
267 		accessmode = VREAD;
268 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
269 			accessmode |= VWRITE;
270 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
271 		error = VOP_EACCESS(devvp, accessmode, cred);
272 		if (error) {
273 			vput(devvp);
274 			return (error);
275 		}
276 		vn_unlock(devvp);
277 	}
278 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
279 		error = mountmsdosfs(devvp, mp, &args);
280 #ifdef MSDOSFS_DEBUG		/* only needed for the kprintf below */
281 		pmp = VFSTOMSDOSFS(mp);
282 #endif
283 	} else {
284 		if (devvp != pmp->pm_devvp)
285 			error = EINVAL;	/* XXX needs translation */
286 		else
287 			vrele(devvp);
288 	}
289 	if (error) {
290 		vrele(devvp);
291 		return (error);
292 	}
293 
294 	error = update_mp(mp, &args);
295 	if (error) {
296 		msdosfs_unmount(mp, MNT_FORCE);
297 		return error;
298 	}
299 
300 	copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
301 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
302 	msdosfs_statfs(mp, &mp->mnt_stat, cred);
303 #ifdef MSDOSFS_DEBUG
304 	kprintf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
305 #endif
306 	return (0);
307 }
308 
309 static int
310 mountmsdosfs(struct vnode *devvp, struct mount *mp, struct msdosfs_args *argp)
311 {
312 	struct msdosfsmount *pmp;
313 	struct buf *bp;
314 	cdev_t dev;
315 	union bootsector *bsp;
316 	struct byte_bpb33 *b33;
317 	struct byte_bpb50 *b50;
318 	struct byte_bpb710 *b710;
319 	u_int8_t SecPerClust;
320 	u_long clusters;
321 	int	ronly, error;
322 
323 	/*
324 	 * Disallow multiple mounts of the same device.
325 	 * Disallow mounting of a device that is currently in use
326 	 * Flush out any old buffers remaining from a previous use.
327 	 */
328 	error = vfs_mountedon(devvp);
329 	if (error)
330 		return (error);
331 	if (vcount(devvp) > 0)
332 		return (EBUSY);
333 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
334 	error = vinvalbuf(devvp, V_SAVE, 0, 0);
335 	vn_unlock(devvp);
336 	if (error)
337 		return (error);
338 
339 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
340 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
341 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, NULL);
342 	vn_unlock(devvp);
343 	if (error)
344 		return (error);
345 	dev = devvp->v_rdev;
346 	bp  = NULL; /* both used in error_exit */
347 	pmp = NULL;
348 
349 	/*
350 	 * Read the boot sector of the filesystem, and then check the
351 	 * boot signature.  If not a dos boot sector then error out.
352 	 *
353 	 * NOTE: 2048 is a maximum sector size in current...
354 	 */
355 	error = bread(devvp, 0, 2048, &bp);
356 	if (error)
357 		goto error_exit;
358 	bp->b_flags |= B_AGE;
359 	bsp = (union bootsector *)bp->b_data;
360 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
361 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
362 	b710 = (struct byte_bpb710 *)bsp->bs710.bsPBP;
363 
364 #ifndef MSDOSFS_NOCHECKSIG
365 	if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
366 	    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
367 		error = EINVAL;
368 		goto error_exit;
369 	}
370 #endif
371 
372 	pmp = kmalloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK | M_ZERO);
373 	pmp->pm_mountp = mp;
374 
375 	/*
376 	 * Compute several useful quantities from the bpb in the
377 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
378 	 * the fields that are different between dos 5 and dos 3.3.
379 	 */
380 	SecPerClust = b50->bpbSecPerClust;
381 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
382 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
383 	pmp->pm_FATs = b50->bpbFATs;
384 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
385 	pmp->pm_Sectors = getushort(b50->bpbSectors);
386 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
387 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
388 	pmp->pm_Heads = getushort(b50->bpbHeads);
389 	pmp->pm_Media = b50->bpbMedia;
390 
391 	/* calculate the ratio of sector size to DEV_BSIZE */
392 	pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
393 
394 	/*
395 	 * We don't check pm_Heads nor pm_SecPerTrack, because
396 	 * these may not be set for EFI file systems. We don't
397 	 * use these anyway, so we're unaffected if they are
398 	 * invalid.
399 	 */
400 	if (!pmp->pm_BytesPerSec || !SecPerClust) {
401 		error = EINVAL;
402 		goto error_exit;
403 	}
404 
405 	if (pmp->pm_Sectors == 0) {
406 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
407 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
408 	} else {
409 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
410 		pmp->pm_HugeSectors = pmp->pm_Sectors;
411 	}
412 
413 	if (pmp->pm_RootDirEnts == 0) {
414 		if (pmp->pm_Sectors
415 		    || pmp->pm_FATsecs
416 		    || getushort(b710->bpbFSVers)) {
417 			error = EINVAL;
418 			kprintf("mountmsdosfs(): bad FAT32 filesystem\n");
419 			goto error_exit;
420 		}
421 		pmp->pm_fatmask = FAT32_MASK;
422 		pmp->pm_fatmult = 4;
423 		pmp->pm_fatdiv = 1;
424 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
425 		if (getushort(b710->bpbExtFlags) & FATMIRROR)
426 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
427 		else
428 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
429 	} else
430 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
431 
432 	/*
433 	 * Check a few values (could do some more):
434 	 * - logical sector size: power of 2, >= block size
435 	 * - sectors per cluster: power of 2, >= 1
436 	 * - number of sectors:   >= 1, <= size of partition
437 	 */
438 	if ( (SecPerClust == 0)
439 	  || (SecPerClust & (SecPerClust - 1))
440 	  || (pmp->pm_BytesPerSec < DEV_BSIZE)
441 	  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
442 	  || (pmp->pm_HugeSectors == 0)
443 	) {
444 		error = EINVAL;
445 		goto error_exit;
446 	}
447 
448 	pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
449 	pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
450 	pmp->pm_FATsecs     *= pmp->pm_BlkPerSec;
451 	SecPerClust         *= pmp->pm_BlkPerSec;
452 
453 	pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
454 
455 	if (FAT32(pmp)) {
456 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
457 		pmp->pm_firstcluster = pmp->pm_fatblk
458 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
459 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
460 	} else {
461 		pmp->pm_rootdirblk = pmp->pm_fatblk +
462 			(pmp->pm_FATs * pmp->pm_FATsecs);
463 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
464 				       + DEV_BSIZE - 1)
465 			/ DEV_BSIZE; /* in blocks */
466 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
467 	}
468 
469 	pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
470 	    SecPerClust + 1;
471 	pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */
472 
473 	if (pmp->pm_fatmask == 0) {
474 		if (pmp->pm_maxcluster
475 		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
476 			/*
477 			 * This will usually be a floppy disk. This size makes
478 			 * sure that one fat entry will not be split across
479 			 * multiple blocks.
480 			 */
481 			pmp->pm_fatmask = FAT12_MASK;
482 			pmp->pm_fatmult = 3;
483 			pmp->pm_fatdiv = 2;
484 		} else {
485 			pmp->pm_fatmask = FAT16_MASK;
486 			pmp->pm_fatmult = 2;
487 			pmp->pm_fatdiv = 1;
488 		}
489 	}
490 
491 	clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
492 	if (pmp->pm_maxcluster >= clusters) {
493 		kprintf("Warning: number of clusters (%ld) exceeds FAT "
494 		    "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
495 		pmp->pm_maxcluster = clusters - 1;
496 	}
497 
498 
499 	if (FAT12(pmp))
500 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
501 	else
502 		pmp->pm_fatblocksize = MSDOSFS_DFLTBSIZE;
503 
504 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
505 	pmp->pm_bnshift = DEV_BSHIFT;
506 
507 	/*
508 	 * Compute mask and shift value for isolating cluster relative byte
509 	 * offsets and cluster numbers from a file offset.
510 	 */
511 	pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
512 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
513 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
514 
515 	/*
516 	 * Check for valid cluster size
517 	 * must be a power of 2
518 	 */
519 	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
520 		error = EINVAL;
521 		goto error_exit;
522 	}
523 
524 	/*
525 	 * Release the bootsector buffer.
526 	 */
527 	bp->b_flags |= B_RELBUF;
528 	brelse(bp);
529 	bp = NULL;
530 
531 	/*
532 	 * Check FSInfo.
533 	 */
534 	if (pmp->pm_fsinfo) {
535 		struct fsinfo *fp;
536 
537 		if ((error = bread(devvp, de_bntodoff(pmp, pmp->pm_fsinfo), fsi_size(pmp), &bp)) != 0)
538 			goto error_exit;
539 		fp = (struct fsinfo *)bp->b_data;
540 		if (!bcmp(fp->fsisig1, "RRaA", 4)
541 		    && !bcmp(fp->fsisig2, "rrAa", 4)
542 		    && !bcmp(fp->fsisig3, "\0\0\125\252", 4)
543 		    && !bcmp(fp->fsisig4, "\0\0\125\252", 4)) {
544 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
545 			if (pmp->pm_nxtfree == 0xffffffff)
546 				pmp->pm_nxtfree = CLUST_FIRST;
547 		} else
548 			pmp->pm_fsinfo = 0;
549 		bp->b_flags |= B_RELBUF;
550 		brelse(bp);
551 		bp = NULL;
552 	}
553 
554 	/*
555 	 * Check and validate (or perhaps invalidate?) the fsinfo structure?
556 	 */
557 	if (pmp->pm_fsinfo && pmp->pm_nxtfree > pmp->pm_maxcluster) {
558 		kprintf(
559 		"Next free cluster in FSInfo (%lu) exceeds maxcluster (%lu)\n",
560 		    pmp->pm_nxtfree, pmp->pm_maxcluster);
561 		error = EINVAL;
562 		goto error_exit;
563 	}
564 
565 	/*
566 	 * Allocate memory for the bitmap of allocated clusters, and then
567 	 * fill it in.
568 	 */
569 	pmp->pm_inusemap = kmalloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
570 				   / N_INUSEBITS)
571 				  * sizeof(*pmp->pm_inusemap),
572 				  M_MSDOSFSFAT, M_WAITOK);
573 
574 	/*
575 	 * fillinusemap() needs pm_devvp.
576 	 */
577 	pmp->pm_dev = dev;
578 	pmp->pm_devvp = devvp;
579 
580 	/*
581 	 * Have the inuse map filled in.
582 	 */
583 	if ((error = fillinusemap(pmp)) != 0)
584 		goto error_exit;
585 
586 	/*
587 	 * If they want fat updates to be synchronous then let them suffer
588 	 * the performance degradation in exchange for the on disk copy of
589 	 * the fat being correct just about all the time.  I suppose this
590 	 * would be a good thing to turn on if the kernel is still flakey.
591 	 */
592 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
593 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
594 
595 	/*
596 	 * Finish up.
597 	 */
598 	if (ronly)
599 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
600 	else
601 		pmp->pm_fmod = 1;
602 	mp->mnt_data = (qaddr_t) pmp;
603 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
604 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
605 	mp->mnt_flag |= MNT_LOCAL;
606 	vfs_add_vnodeops(mp, &msdosfs_vnode_vops, &mp->mnt_vn_norm_ops);
607 	dev->si_mountpoint = mp;
608 
609 	return 0;
610 
611 error_exit:
612 	if (bp) {
613 		bp->b_flags |= B_RELBUF;
614 		brelse(bp);
615 	}
616 	VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE);
617 	if (pmp) {
618 		if (pmp->pm_inusemap)
619 			kfree(pmp->pm_inusemap, M_MSDOSFSFAT);
620 		kfree(pmp, M_MSDOSFSMNT);
621 		mp->mnt_data = (qaddr_t)0;
622 	}
623 	return (error);
624 }
625 
626 /*
627  * Unmount the filesystem described by mp.
628  */
629 static int
630 msdosfs_unmount(struct mount *mp, int mntflags)
631 {
632 	struct msdosfsmount *pmp;
633 	int error, flags;
634 
635 	flags = 0;
636 	if (mntflags & MNT_FORCE)
637 		flags |= FORCECLOSE;
638 	error = vflush(mp, 0, flags);
639 	if (error)
640 		return error;
641 	pmp = VFSTOMSDOSFS(mp);
642 	pmp->pm_devvp->v_rdev->si_mountpoint = NULL;
643 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdos_iconv) {
644 		if(pmp->pm_w2u)
645 			msdos_iconv->close(pmp->pm_w2u);
646 		if(pmp->pm_u2w)
647 			msdos_iconv->close(pmp->pm_u2w);
648 		if(pmp->pm_d2u)
649 			msdos_iconv->close(pmp->pm_d2u);
650 		if(pmp->pm_u2d)
651 			msdos_iconv->close(pmp->pm_u2d);
652 	}
653 #ifdef MSDOSFS_DEBUG
654 	{
655 		struct vnode *vp = pmp->pm_devvp;
656 
657 		kprintf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
658 		kprintf("flag %08x, sysrefs %d, writecount %d, auxrefs %d\n",
659 		    vp->v_flag, vp->v_sysref.refcnt,
660 		    vp->v_writecount, vp->v_auxrefs);
661 		kprintf("mount %p, op %p\n", vp->v_mount, vp->v_ops);
662 		kprintf("mount %p\n", vp->v_mount);
663 		kprintf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
664 		    RB_ROOT(&vp->v_rbclean_tree),
665 		    RB_ROOT(&vp->v_rbdirty_tree),
666 		    bio_track_active(&vp->v_track_write),
667 		    vp->v_type);
668 		kprintf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
669 		    vp->v_socket, vp->v_tag,
670 		    ((u_int *)vp->v_data)[0],
671 		    ((u_int *)vp->v_data)[1]);
672 	}
673 #endif
674 	error = VOP_CLOSE(pmp->pm_devvp,
675 		    (pmp->pm_flags&MSDOSFSMNT_RONLY) ? FREAD : FREAD | FWRITE);
676 	vrele(pmp->pm_devvp);
677 	kfree(pmp->pm_inusemap, M_MSDOSFSFAT);
678 	kfree(pmp, M_MSDOSFSMNT);
679 	mp->mnt_data = (qaddr_t)0;
680 	mp->mnt_flag &= ~MNT_LOCAL;
681 	return (error);
682 }
683 
684 static int
685 msdosfs_root(struct mount *mp, struct vnode **vpp)
686 {
687 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
688 	struct denode *ndep;
689 	int error;
690 
691 #ifdef MSDOSFS_DEBUG
692 	kprintf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
693 #endif
694 	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
695 	if (error)
696 		return (error);
697 	*vpp = DETOV(ndep);
698 	return (0);
699 }
700 
701 static int
702 msdosfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
703 {
704 	struct msdosfsmount *pmp;
705 
706 	pmp = VFSTOMSDOSFS(mp);
707 	sbp->f_bsize = pmp->pm_bpcluster;
708 	sbp->f_iosize = pmp->pm_bpcluster;
709 	sbp->f_blocks = pmp->pm_maxcluster + 1;
710 	sbp->f_bfree = pmp->pm_freeclustercount;
711 	sbp->f_bavail = pmp->pm_freeclustercount;
712 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
713 	sbp->f_ffree = 0;	/* what to put in here? */
714 	if (sbp != &mp->mnt_stat) {
715 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
716 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
717 	}
718 	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
719 	return (0);
720 }
721 
722 struct scaninfo {
723 	int rescan;
724 	int allerror;
725 	int waitfor;
726 };
727 
728 static int msdosfs_sync_scan(struct mount *mp, struct vnode *vp, void *data);
729 
730 static int
731 msdosfs_sync(struct mount *mp, int waitfor)
732 {
733 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
734 	struct scaninfo scaninfo;
735 	int error;
736 
737 	/*
738 	 * If we ever switch to not updating all of the fats all the time,
739 	 * this would be the place to update them from the first one.
740 	 */
741 	if (pmp->pm_fmod != 0) {
742 		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
743 			panic("msdosfs_sync: rofs mod");
744 		else {
745 			/* update fats here */
746 		}
747 	}
748 	/*
749 	 * Write back each (modified) denode.
750 	 */
751 	scaninfo.allerror = 0;
752 	scaninfo.rescan = 1;
753 	while (scaninfo.rescan) {
754 		scaninfo.rescan = 0;
755 		vmntvnodescan(mp, VMSC_GETVP|VMSC_NOWAIT, NULL, msdosfs_sync_scan, &scaninfo);
756 	}
757 
758 	/*
759 	 * Flush filesystem control info.
760 	 */
761 	if ((waitfor & MNT_LAZY) == 0) {
762 		vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
763 		if ((error = VOP_FSYNC(pmp->pm_devvp, waitfor, 0)) != 0)
764 			scaninfo.allerror = error;
765 		vn_unlock(pmp->pm_devvp);
766 	}
767 	return (scaninfo.allerror);
768 }
769 
770 static int
771 msdosfs_sync_scan(struct mount *mp, struct vnode *vp, void *data)
772 {
773 	struct scaninfo *info = data;
774 	struct denode *dep;
775 	int error;
776 
777 	dep = VTODE(vp);
778 	if (vp->v_type == VNON || vp->v_type == VBAD ||
779 	    ((dep->de_flag &
780 	    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
781 	    (RB_EMPTY(&vp->v_rbdirty_tree) || (info->waitfor & MNT_LAZY)))) {
782 		return(0);
783 	}
784 	if ((error = VOP_FSYNC(vp, info->waitfor, 0)) != 0)
785 		info->allerror = error;
786 	return(0);
787 }
788 
789 static int
790 msdosfs_fhtovp(struct mount *mp, struct vnode *rootvp,
791 	       struct fid *fhp, struct vnode **vpp)
792 {
793 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
794 	struct defid *defhp = (struct defid *) fhp;
795 	struct denode *dep;
796 	int error;
797 
798 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
799 	if (error) {
800 		*vpp = NULLVP;
801 		return (error);
802 	}
803 	*vpp = DETOV(dep);
804 	return (0);
805 }
806 
807 static int
808 msdosfs_checkexp(struct mount *mp, struct sockaddr *nam, int *exflagsp,
809 		 struct ucred **credanonp)
810 {
811 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
812 	struct netcred *np;
813 
814 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
815 	if (np == NULL)
816 		return (EACCES);
817 	*exflagsp = np->netc_exflags;
818 	*credanonp = &np->netc_anon;
819 	return (0);
820 }
821 
822 static int
823 msdosfs_vptofh(struct vnode *vp, struct fid *fhp)
824 {
825 	struct denode *dep;
826 	struct defid *defhp;
827 
828 	dep = VTODE(vp);
829 	defhp = (struct defid *)fhp;
830 	defhp->defid_len = sizeof(struct defid);
831 	defhp->defid_dirclust = dep->de_dirclust;
832 	defhp->defid_dirofs = dep->de_diroffset;
833 	/* defhp->defid_gen = dep->de_gen; */
834 	return (0);
835 }
836 
837 static struct vfsops msdosfs_vfsops = {
838 	.vfs_mount =     	msdosfs_mount,
839 	.vfs_unmount =   	msdosfs_unmount,
840 	.vfs_root =     	msdosfs_root,
841 	.vfs_statfs =   	msdosfs_statfs,
842 	.vfs_sync =     	msdosfs_sync,
843 	.vfs_fhtovp =   	msdosfs_fhtovp,
844 	.vfs_checkexp =  	msdosfs_checkexp,
845 	.vfs_vptofh =   	msdosfs_vptofh,
846 	.vfs_init =     	msdosfs_init,
847 	.vfs_uninit =   	msdosfs_uninit
848 };
849 
850 VFS_SET(msdosfs_vfsops, msdos, 0);
851 MODULE_VERSION(msdos, 1);
852