xref: /dflybsd-src/sys/vfs/msdosfs/msdosfs_vfsops.c (revision 8bdbc095884336714d87f2877b79c17d22de5cd3)
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 /*	$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/proc.h>
55 #include <sys/nlookup.h>
56 #include <sys/kernel.h>
57 #include <sys/vnode.h>
58 #include <sys/iconv.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 <sys/buf2.h>
67 
68 #include "bpb.h"
69 #include "bootsect.h"
70 #include "direntry.h"
71 #include "denode.h"
72 #include "msdosfsmount.h"
73 #include "fat.h"
74 
75 extern struct vop_ops msdosfs_vnode_vops;
76 struct iconv_functions *msdos_iconv;
77 
78 #define MSDOSFS_DFLTBSIZE       4096
79 #define ENCODING_UNICODE        "UTF-16BE"
80 #if 1 /*def PC98*/
81 /*
82  * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
83  *       garbage or a random value :-{
84  *       If you want to use that broken-signatured media, define the
85  *       following symbol even though PC/AT.
86  *       (ex. mount PC-98 DOS formatted FD on PC/AT)
87  */
88 #define	MSDOSFS_NOCHECKSIG
89 #endif
90 
91 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
92 static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
93 
94 static int mountmsdosfs(struct vnode *devvp, struct mount *mp,
95     struct msdosfs_args *argp);
96 static int msdosfs_root(struct mount *, struct vnode **);
97 static int msdosfs_statfs(struct mount *, struct statfs *, struct ucred *);
98 static int msdosfs_unmount(struct mount *, int);
99 
100 static int
101 update_mp(struct mount *mp, struct msdosfs_args *argp)
102 {
103 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
104 	int error;
105         char cs_local[ICONV_CSNMAXLEN];
106         char cs_dos[ICONV_CSNMAXLEN];
107 
108 	pmp->pm_gid = argp->gid;
109 	pmp->pm_uid = argp->uid;
110 	pmp->pm_mask = argp->mask & ALLPERMS;
111 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
112 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdos_iconv) {
113 		bcopy(argp->cs_local, cs_local, sizeof(cs_local));
114 		bcopy(argp->cs_dos, cs_dos, sizeof(cs_dos));
115 		kprintf("local: %s dos: %s\n",argp->cs_local, argp->cs_dos);
116 		error = msdos_iconv->open(cs_local, ENCODING_UNICODE,
117 					  &pmp->pm_w2u);
118 		if(error)
119 			return error;
120 		error = msdos_iconv->open(ENCODING_UNICODE, cs_local,
121 					  &pmp->pm_u2w);
122 		if(error)
123 			return error;
124 		error = msdos_iconv->open(cs_dos, cs_local, &pmp->pm_u2d);
125 		if(error)
126 			return error;
127 		error = msdos_iconv->open(cs_local, cs_dos, &pmp->pm_d2u);
128 		if(error)
129 			return error;
130 	}
131 
132 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95) {
133 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
134 	} else if (!(pmp->pm_flags &
135 	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
136 		/*
137 		 * Try to divine whether to support Win'95 long filenames
138 		 */
139 		if (FAT32(pmp)) {
140 			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
141 		} else {
142 			struct vnode *rootvp;
143 			if ((error = msdosfs_root(mp, &rootvp)) != 0)
144 				return error;
145 			pmp->pm_flags |= findwin95(VTODE(rootvp))
146 				? MSDOSFSMNT_LONGNAME : MSDOSFSMNT_SHORTNAME;
147 			vput(rootvp);
148 		}
149 	}
150 	return 0;
151 }
152 
153 /*
154  * mp - path - addr in user space of mount point (ie /usr or whatever)
155  * data - addr in user space of mount params including the name of the block
156  * special file to treat as a filesystem.
157  */
158 static int
159 msdosfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
160 {
161 	struct vnode *devvp;	  /* vnode for blk device to mount */
162 	struct msdosfs_args args; /* will hold data from mount request */
163 	/* msdosfs specific mount control block */
164 	struct msdosfsmount *pmp = NULL;
165 	size_t size;
166 	int error, flags;
167 	mode_t accessmode;
168 	struct nlookupdata nd;
169 
170 	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
171 	if (error)
172 		return (error);
173 	if (args.magic != MSDOSFS_ARGSMAGIC)
174 		args.flags = 0;
175 	/*
176 	 * If updating, check whether changing from read-only to
177 	 * read/write; if there is no device name, that's all we do.
178 	 */
179 	if (mp->mnt_flag & MNT_UPDATE) {
180 		pmp = VFSTOMSDOSFS(mp);
181 		error = 0;
182 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
183 		    (mp->mnt_flag & MNT_RDONLY)) {
184 			flags = WRITECLOSE;
185 			if (mp->mnt_flag & MNT_FORCE)
186 				flags |= FORCECLOSE;
187 			error = vflush(mp, 0, flags);
188 			if (error == 0) {
189 				devvp = pmp->pm_devvp;
190 				vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
191 				VOP_OPEN(devvp, FREAD, FSCRED, NULL);
192 				VOP_CLOSE(devvp, FREAD|FWRITE, NULL);
193 				vn_unlock(devvp);
194 				pmp->pm_flags |= MSDOSFSMNT_RONLY;
195 			}
196 		}
197 		if (!error && (mp->mnt_flag & MNT_RELOAD))
198 			/* not yet implemented */
199 			error = EOPNOTSUPP;
200 		if (error)
201 			return (error);
202 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
203 		    (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
204 			/*
205 			 * If upgrade to read-write by non-root, then verify
206 			 * that user has necessary permissions on the device.
207 			 */
208 			devvp = pmp->pm_devvp;
209 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
210 			if (cred->cr_uid != 0) {
211 				error = VOP_EACCESS(devvp, VREAD | VWRITE,
212 						    cred);
213 				if (error) {
214 					vn_unlock(devvp);
215 					return (error);
216 				}
217 			}
218 			VOP_OPEN(devvp, FREAD|FWRITE, FSCRED, NULL);
219 			VOP_CLOSE(devvp, FREAD, NULL);
220 			vn_unlock(devvp);
221 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
222 		}
223 		if (args.fspec == NULL) {
224 #ifdef __notyet__	/* doesn't work correctly with current mountd XXX */
225 			if (args.flags & MSDOSFSMNT_MNTOPT) {
226 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
227 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
228 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
229 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
230 			}
231 #endif
232 			/*
233 			 * Process export requests.
234 			 */
235 			return (vfs_export(mp, &pmp->pm_export, &args.export));
236 		}
237 	}
238 	/*
239 	 * Not an update, or updating the name: look up the name
240 	 * and verify that it refers to a sensible block device.
241 	 */
242 	devvp = NULL;
243 	error = nlookup_init(&nd, args.fspec, UIO_USERSPACE, NLC_FOLLOW);
244 	if (error == 0)
245 		error = nlookup(&nd);
246 	if (error == 0)
247 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
248 	nlookup_done(&nd);
249 	if (error)
250 		return (error);
251 
252 	if (!vn_isdisk(devvp, &error)) {
253 		vrele(devvp);
254 		return (error);
255 	}
256 	/*
257 	 * If mount by non-root, then verify that user has necessary
258 	 * permissions on the device.
259 	 */
260 	if (cred->cr_uid != 0) {
261 		accessmode = VREAD;
262 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
263 			accessmode |= VWRITE;
264 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
265 		error = VOP_EACCESS(devvp, accessmode, cred);
266 		if (error) {
267 			vput(devvp);
268 			return (error);
269 		}
270 		vn_unlock(devvp);
271 	}
272 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
273 		error = mountmsdosfs(devvp, mp, &args);
274 #ifdef MSDOSFS_DEBUG		/* only needed for the kprintf below */
275 		pmp = VFSTOMSDOSFS(mp);
276 #endif
277 	} else {
278 		if (devvp != pmp->pm_devvp)
279 			error = EINVAL;	/* XXX needs translation */
280 		else
281 			vrele(devvp);
282 	}
283 	if (error) {
284 		vrele(devvp);
285 		return (error);
286 	}
287 
288 	error = update_mp(mp, &args);
289 	if (error) {
290 		msdosfs_unmount(mp, MNT_FORCE);
291 		return error;
292 	}
293 
294 	copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
295 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
296 	msdosfs_statfs(mp, &mp->mnt_stat, cred);
297 #ifdef MSDOSFS_DEBUG
298 	kprintf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n",
299 		mp, pmp, pmp->pm_inusemap);
300 #endif
301 	return (0);
302 }
303 
304 static int
305 mountmsdosfs(struct vnode *devvp, struct mount *mp, struct msdosfs_args *argp)
306 {
307 	struct msdosfsmount *pmp;
308 	struct buf *bp;
309 	cdev_t dev;
310 	union bootsector *bsp;
311 	struct byte_bpb33 *b33;
312 	struct byte_bpb50 *b50;
313 	struct byte_bpb710 *b710;
314 	u_int8_t SecPerClust;
315 	u_long clusters;
316 	int ronly, error;
317 
318 	/*
319 	 * Disallow multiple mounts of the same device.
320 	 * Disallow mounting of a device that is currently in use
321 	 * Flush out any old buffers remaining from a previous use.
322 	 */
323 	error = vfs_mountedon(devvp);
324 	if (error)
325 		return (error);
326 	if (vcount(devvp) > 0)
327 		return (EBUSY);
328 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
329 	error = vinvalbuf(devvp, V_SAVE, 0, 0);
330 	vn_unlock(devvp);
331 	if (error)
332 		return (error);
333 
334 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
335 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
336 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, NULL);
337 	vn_unlock(devvp);
338 	if (error)
339 		return (error);
340 	dev = devvp->v_rdev;
341 	bp  = NULL; /* both used in error_exit */
342 	pmp = NULL;
343 
344 	/*
345 	 * Read the boot sector of the filesystem, and then check the
346 	 * boot signature.  If not a dos boot sector then error out.
347 	 *
348 	 * NOTE: 2048 is a maximum sector size in current...
349 	 */
350 	error = bread(devvp, 0, 2048, &bp);
351 	if (error)
352 		goto error_exit;
353 	bp->b_flags |= B_AGE;
354 	bsp = (union bootsector *)bp->b_data;
355 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
356 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
357 	b710 = (struct byte_bpb710 *)bsp->bs710.bsPBP;
358 
359 #ifndef MSDOSFS_NOCHECKSIG
360 	if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
361 	    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
362 		error = EINVAL;
363 		goto error_exit;
364 	}
365 #endif
366 
367 	pmp = kmalloc(sizeof(*pmp), M_MSDOSFSMNT, M_WAITOK | M_ZERO);
368 	pmp->pm_mountp = mp;
369 
370 	/*
371 	 * Compute several useful quantities from the bpb in the
372 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
373 	 * the fields that are different between dos 5 and dos 3.3.
374 	 */
375 	SecPerClust = b50->bpbSecPerClust;
376 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
377 	if (pmp->pm_BytesPerSec < DEV_BSIZE) {
378 		error = EINVAL;
379 		goto error_exit;
380 	}
381 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
382 	pmp->pm_FATs = b50->bpbFATs;
383 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
384 	pmp->pm_Sectors = getushort(b50->bpbSectors);
385 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
386 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
387 	pmp->pm_Heads = getushort(b50->bpbHeads);
388 	pmp->pm_Media = b50->bpbMedia;
389 
390 	/* calculate the ratio of sector size to DEV_BSIZE */
391 	pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
392 
393 	/*
394 	 * We don't check pm_Heads nor pm_SecPerTrack, because
395 	 * these may not be set for EFI file systems. We don't
396 	 * use these anyway, so we're unaffected if they are
397 	 * invalid.
398 	 */
399 	if (!pmp->pm_BytesPerSec || !SecPerClust) {
400 		error = EINVAL;
401 		goto error_exit;
402 	}
403 
404 	if (pmp->pm_Sectors == 0) {
405 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
406 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
407 	} else {
408 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
409 		pmp->pm_HugeSectors = pmp->pm_Sectors;
410 	}
411 
412 	if (pmp->pm_RootDirEnts == 0) {
413 		if (pmp->pm_Sectors
414 		    || pmp->pm_FATsecs
415 		    || getushort(b710->bpbFSVers)) {
416 			error = EINVAL;
417 			kprintf("mountmsdosfs(): bad FAT32 filesystem\n");
418 			goto error_exit;
419 		}
420 		pmp->pm_fatmask = FAT32_MASK;
421 		pmp->pm_fatmult = 4;
422 		pmp->pm_fatdiv = 1;
423 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
424 		if (getushort(b710->bpbExtFlags) & FATMIRROR)
425 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
426 		else
427 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
428 	} else
429 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
430 
431 	/*
432 	 * Check a few values (could do some more):
433 	 * - logical sector size: power of 2, >= block size
434 	 * - sectors per cluster: power of 2, >= 1
435 	 * - number of sectors:   >= 1, <= size of partition
436 	 * - number of FAT sectors: >= 1
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 	  || (pmp->pm_FATsecs == 0)
444 	  || (SecPerClust * pmp->pm_BlkPerSec > MAXBSIZE / DEV_BSIZE)) {
445 		error = EINVAL;
446 		goto error_exit;
447 	}
448 
449 	pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
450 	pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
451 	pmp->pm_FATsecs     *= pmp->pm_BlkPerSec;
452 	SecPerClust         *= pmp->pm_BlkPerSec;
453 
454 	pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
455 
456 	if (FAT32(pmp)) {
457 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
458 		pmp->pm_firstcluster = pmp->pm_fatblk
459 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
460 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
461 	} else {
462 		pmp->pm_rootdirblk = pmp->pm_fatblk +
463 			(pmp->pm_FATs * pmp->pm_FATsecs);
464 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts *
465 			sizeof(struct direntry) + DEV_BSIZE - 1)
466 			/ DEV_BSIZE; /* in blocks */
467 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
468 	}
469 
470 	pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
471 	    SecPerClust + 1;
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_FATsecs * DEV_BSIZE) / pmp->pm_fatmult) *
492 		pmp->pm_fatdiv;
493 	if (pmp->pm_maxcluster >= clusters) {
494 		kprintf("Warning: number of clusters (%ld) exceeds FAT "
495 		    "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
496 		pmp->pm_maxcluster = clusters - 1;
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),
538 		    fsi_size(pmp), &bp)) != 0)
539 			goto error_exit;
540 		fp = (struct fsinfo *)bp->b_data;
541 		if (!bcmp(fp->fsisig1, "RRaA", 4) &&
542 		    !bcmp(fp->fsisig2, "rrAa", 4) &&
543 		    !bcmp(fp->fsisig3, "\0\0\125\252", 4) &&
544 		    !bcmp(fp->fsisig4, "\0\0\125\252", 4)) {
545 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
546 			if (pmp->pm_nxtfree == (u_long)-1)
547 				pmp->pm_nxtfree = CLUST_FIRST;
548 			if (pmp->pm_nxtfree == (u_int)-1) {
549 				kprintf("msdosfs_mount(): "
550 					"ignoring illegal nxtfree 0x%016jx\n",
551 					(uintmax_t)pmp->pm_nxtfree);
552 				pmp->pm_nxtfree = CLUST_FIRST;
553 			}
554 		} else
555 			pmp->pm_fsinfo = 0;
556 		bp->b_flags |= B_RELBUF;
557 		brelse(bp);
558 		bp = NULL;
559 	}
560 
561 	/*
562 	 * Check and validate (or perhaps invalidate?) the fsinfo structure?
563 	 */
564 	if (pmp->pm_fsinfo && pmp->pm_nxtfree > pmp->pm_maxcluster) {
565 		kprintf(
566 		"Next free cluster in FSInfo (%lu) exceeds maxcluster (%lu)\n",
567 		    pmp->pm_nxtfree, pmp->pm_maxcluster);
568 		error = EINVAL;
569 		goto error_exit;
570 	}
571 
572 	/*
573 	 * Allocate memory for the bitmap of allocated clusters, and then
574 	 * fill it in.
575 	 */
576 	pmp->pm_inusemap = kmalloc(((pmp->pm_maxcluster + N_INUSEBITS - 1)
577 				   / N_INUSEBITS) * sizeof(*pmp->pm_inusemap),
578 				   M_MSDOSFSFAT, M_WAITOK);
579 
580 	/*
581 	 * fillinusemap() needs pm_devvp.
582 	 */
583 	pmp->pm_dev = dev;
584 	pmp->pm_devvp = devvp;
585 
586 	/*
587 	 * Have the inuse map filled in.
588 	 */
589 	if ((error = fillinusemap(pmp)) != 0)
590 		goto error_exit;
591 
592 	/*
593 	 * If they want fat updates to be synchronous then let them suffer
594 	 * the performance degradation in exchange for the on disk copy of
595 	 * the fat being correct just about all the time.  I suppose this
596 	 * would be a good thing to turn on if the kernel is still flakey.
597 	 */
598 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
599 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
600 
601 	/*
602 	 * Finish up.
603 	 */
604 	if (ronly)
605 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
606 	else
607 		pmp->pm_fmod = 1;
608 	mp->mnt_data = (qaddr_t) pmp;
609 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
610 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
611 	mp->mnt_flag |= MNT_LOCAL;
612 	vfs_add_vnodeops(mp, &msdosfs_vnode_vops, &mp->mnt_vn_norm_ops);
613 	dev->si_mountpoint = mp;
614 
615 	return 0;
616 
617 error_exit:
618 	if (bp) {
619 		bp->b_flags |= B_RELBUF;
620 		brelse(bp);
621 	}
622 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
623 	VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE, NULL);
624 	vn_unlock(devvp);
625 	if (pmp) {
626 		if (pmp->pm_inusemap)
627 			kfree(pmp->pm_inusemap, M_MSDOSFSFAT);
628 		kfree(pmp, M_MSDOSFSMNT);
629 		mp->mnt_data = (qaddr_t)0;
630 	}
631 	return (error);
632 }
633 
634 /*
635  * Unmount the filesystem described by mp.
636  */
637 static int
638 msdosfs_unmount(struct mount *mp, int mntflags)
639 {
640 	struct msdosfsmount *pmp;
641 	int error, flags;
642 #ifdef MSDOSFS_DEBUG
643 	struct vnode *vp;
644 #endif
645 	flags = 0;
646 	if (mntflags & MNT_FORCE)
647 		flags |= FORCECLOSE;
648 	error = vflush(mp, 0, flags);
649 	if (error)
650 		return error;
651 	pmp = VFSTOMSDOSFS(mp);
652 	pmp->pm_devvp->v_rdev->si_mountpoint = NULL;
653 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdos_iconv) {
654 		if(pmp->pm_w2u)
655 			msdos_iconv->close(pmp->pm_w2u);
656 		if(pmp->pm_u2w)
657 			msdos_iconv->close(pmp->pm_u2w);
658 		if(pmp->pm_d2u)
659 			msdos_iconv->close(pmp->pm_d2u);
660 		if(pmp->pm_u2d)
661 			msdos_iconv->close(pmp->pm_u2d);
662 	}
663 
664 #ifdef MSDOSFS_DEBUG
665 	vp = pmp->pm_devvp;
666 	kprintf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
667 	kprintf("flag %08x, refcnt 0x%08x, writecount %d, auxrefs 0x%08x\n",
668 		vp->v_flag, vp->v_refcnt, vp->v_writecount, vp->v_auxrefs);
669 	kprintf("mount %p, op %p\n", vp->v_mount, vp->v_ops);
670 	kprintf("mount %p\n", vp->v_mount);
671 	kprintf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
672 		RB_ROOT(&vp->v_rbclean_tree), RB_ROOT(&vp->v_rbdirty_tree),
673 		bio_track_active(&vp->v_track_write), vp->v_type);
674 	kprintf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
675 		vp->v_socket, vp->v_tag, ((u_int *)vp->v_data)[0],
676 		((u_int *)vp->v_data)[1]);
677 #endif
678 
679 	vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
680 	error = VOP_CLOSE(pmp->pm_devvp,
681 		    (pmp->pm_flags&MSDOSFSMNT_RONLY) ? FREAD : FREAD | FWRITE,
682 		    NULL);
683 	vn_unlock(pmp->pm_devvp);
684 	vrele(pmp->pm_devvp);
685 	kfree(pmp->pm_inusemap, M_MSDOSFSFAT);
686 	kfree(pmp, M_MSDOSFSMNT);
687 	mp->mnt_data = (qaddr_t)0;
688 	mp->mnt_flag &= ~MNT_LOCAL;
689 	return (error);
690 }
691 
692 static int
693 msdosfs_root(struct mount *mp, struct vnode **vpp)
694 {
695 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
696 	struct denode *ndep;
697 	int error;
698 
699 	mprintf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
700 	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
701 	if (error)
702 		return (error);
703 	*vpp = DETOV(ndep);
704 	return (0);
705 }
706 
707 static int
708 msdosfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
709 {
710 	struct msdosfsmount *pmp;
711 
712 	pmp = VFSTOMSDOSFS(mp);
713 	sbp->f_bsize = pmp->pm_bpcluster;
714 	sbp->f_iosize = pmp->pm_bpcluster;
715 	sbp->f_blocks = pmp->pm_maxcluster + 1;
716 	sbp->f_bfree = pmp->pm_freeclustercount;
717 	sbp->f_bavail = pmp->pm_freeclustercount;
718 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
719 	sbp->f_ffree = 0;	/* what to put in here? */
720 	if (sbp != &mp->mnt_stat) {
721 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
722 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
723 	}
724 	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
725 	return (0);
726 }
727 
728 struct scaninfo {
729 	int rescan;
730 	int allerror;
731 	int waitfor;
732 };
733 
734 static int msdosfs_sync_scan(struct mount *mp, struct vnode *vp, void *data);
735 
736 static int
737 msdosfs_sync(struct mount *mp, int waitfor)
738 {
739 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
740 	struct scaninfo scaninfo;
741 	int error;
742 
743 	/*
744 	 * If we ever switch to not updating all of the fats all the time,
745 	 * this would be the place to update them from the first one.
746 	 */
747 	if (pmp->pm_fmod != 0) {
748 		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
749 			panic("msdosfs_sync: rofs mod");
750 		else {
751 			/* update fats here */
752 		}
753 	}
754 	/*
755 	 * Write back each (modified) denode.
756 	 */
757 	scaninfo.allerror = 0;
758 	scaninfo.rescan = 1;
759 	while (scaninfo.rescan) {
760 		scaninfo.rescan = 0;
761 		vmntvnodescan(mp, VMSC_GETVP|VMSC_NOWAIT, NULL,
762 			      msdosfs_sync_scan, &scaninfo);
763 	}
764 
765 	/*
766 	 * Flush filesystem control info.
767 	 */
768 	if ((waitfor & MNT_LAZY) == 0) {
769 		vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
770 		if ((error = VOP_FSYNC(pmp->pm_devvp, waitfor, 0)) != 0)
771 			scaninfo.allerror = error;
772 		vn_unlock(pmp->pm_devvp);
773 	}
774 	return (scaninfo.allerror);
775 }
776 
777 static int
778 msdosfs_sync_scan(struct mount *mp, struct vnode *vp, void *data)
779 {
780 	struct scaninfo *info = data;
781 	struct denode *dep;
782 	int error;
783 
784 	dep = VTODE(vp);
785 	if (vp->v_type == VNON || vp->v_type == VBAD ||
786 	    ((dep->de_flag &
787 	    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
788 	    (RB_EMPTY(&vp->v_rbdirty_tree) || (info->waitfor & MNT_LAZY)))) {
789 		return(0);
790 	}
791 	if ((error = VOP_FSYNC(vp, info->waitfor, 0)) != 0)
792 		info->allerror = error;
793 	return(0);
794 }
795 
796 static int
797 msdosfs_fhtovp(struct mount *mp, struct vnode *rootvp,
798 	       struct fid *fhp, struct vnode **vpp)
799 {
800 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
801 	struct defid *defhp = (struct defid *) fhp;
802 	struct denode *dep;
803 	int error;
804 
805 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
806 	if (error) {
807 		*vpp = NULLVP;
808 		return (error);
809 	}
810 	*vpp = DETOV(dep);
811 	return (0);
812 }
813 
814 static int
815 msdosfs_checkexp(struct mount *mp, struct sockaddr *nam, int *exflagsp,
816 		 struct ucred **credanonp)
817 {
818 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
819 	struct netcred *np;
820 
821 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
822 	if (np == NULL)
823 		return (EACCES);
824 	*exflagsp = np->netc_exflags;
825 	*credanonp = &np->netc_anon;
826 	return (0);
827 }
828 
829 static int
830 msdosfs_vptofh(struct vnode *vp, struct fid *fhp)
831 {
832 	struct denode *dep;
833 	struct defid *defhp;
834 
835 	dep = VTODE(vp);
836 	defhp = (struct defid *)fhp;
837 	defhp->defid_len = sizeof(struct defid);
838 	defhp->defid_dirclust = dep->de_dirclust;
839 	defhp->defid_dirofs = dep->de_diroffset;
840 	/* defhp->defid_gen = dep->de_gen; */
841 	return (0);
842 }
843 
844 static struct vfsops msdosfs_vfsops = {
845 	.vfs_mount =		msdosfs_mount,
846 	.vfs_unmount =		msdosfs_unmount,
847 	.vfs_root =		msdosfs_root,
848 	.vfs_statfs =		msdosfs_statfs,
849 	.vfs_sync =		msdosfs_sync,
850 	.vfs_fhtovp =		msdosfs_fhtovp,
851 	.vfs_checkexp =		msdosfs_checkexp,
852 	.vfs_vptofh =		msdosfs_vptofh,
853 	.vfs_init =		msdosfs_init,
854 	.vfs_uninit =		msdosfs_uninit
855 };
856 
857 VFS_SET(msdosfs_vfsops, msdos, 0);
858 MODULE_VERSION(msdos, 1);
859