xref: /freebsd/sys/fs/msdosfs/msdosfs_vfsops.c (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
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/bio.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 <sys/iconv.h>
65 #include <sys/mutex.h>
66 
67 #include <fs/msdosfs/bpb.h>
68 #include <fs/msdosfs/bootsect.h>
69 #include <fs/msdosfs/msdosfsmount.h>
70 #include <fs/msdosfs/direntry.h>
71 #include <fs/msdosfs/denode.h>
72 #include <fs/msdosfs/fat.h>
73 
74 #define MSDOSFS_DFLTBSIZE       4096
75 
76 #if 1 /*def PC98*/
77 /*
78  * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
79  *       garbage or a random value :-{
80  *       If you want to use that broken-signatured media, define the
81  *       following symbol even though PC/AT.
82  *       (ex. mount PC-98 DOS formatted FD on PC/AT)
83  */
84 #define	MSDOSFS_NOCHECKSIG
85 #endif
86 
87 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
88 static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
89 
90 struct iconv_functions *msdosfs_iconv = NULL;
91 
92 static int	update_mp(struct mount *mp, struct msdosfs_args *argp);
93 static int	mountmsdosfs(struct vnode *devvp, struct mount *mp,
94 		    struct thread *td, struct msdosfs_args *argp);
95 static vfs_fhtovp_t	msdosfs_fhtovp;
96 static vfs_mount_t	msdosfs_mount;
97 static vfs_root_t	msdosfs_root;
98 static vfs_statfs_t	msdosfs_statfs;
99 static vfs_sync_t	msdosfs_sync;
100 static vfs_unmount_t	msdosfs_unmount;
101 static vfs_vptofh_t	msdosfs_vptofh;
102 
103 static int
104 update_mp(mp, argp)
105 	struct mount *mp;
106 	struct msdosfs_args *argp;
107 {
108 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
109 	int error;
110 
111 	pmp->pm_gid = argp->gid;
112 	pmp->pm_uid = argp->uid;
113 	pmp->pm_mask = argp->mask & ALLPERMS;
114 	pmp->pm_dirmask = argp->dirmask & ALLPERMS;
115 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
116 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
117 		msdosfs_iconv->open(argp->cs_win, argp->cs_local , &pmp->pm_u2w);
118 		msdosfs_iconv->open(argp->cs_local, argp->cs_win , &pmp->pm_w2u);
119 		msdosfs_iconv->open(argp->cs_dos, argp->cs_local , &pmp->pm_u2d);
120 		msdosfs_iconv->open(argp->cs_local, argp->cs_dos , &pmp->pm_d2u);
121 	} else {
122 		pmp->pm_w2u = NULL;
123 		pmp->pm_u2w = NULL;
124 		pmp->pm_d2u = NULL;
125 		pmp->pm_u2d = NULL;
126 	}
127 
128 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
129 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
130 	else if (!(pmp->pm_flags &
131 	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
132 		struct vnode *rootvp;
133 
134 		/*
135 		 * Try to divine whether to support Win'95 long filenames
136 		 */
137 		if (FAT32(pmp))
138 			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
139 		else {
140 			if ((error = msdosfs_root(mp, &rootvp)) != 0)
141 				return error;
142 			pmp->pm_flags |= findwin95(VTODE(rootvp))
143 				? MSDOSFSMNT_LONGNAME
144 					: MSDOSFSMNT_SHORTNAME;
145 			vput(rootvp);
146 		}
147 	}
148 	return 0;
149 }
150 
151 /*
152  * mp - path - addr in user space of mount point (ie /usr or whatever)
153  * data - addr in user space of mount params including the name of the block
154  * special file to treat as a filesystem.
155  */
156 static int
157 msdosfs_mount(mp, path, data, ndp, td)
158 	struct mount *mp;
159 	char *path;
160 	caddr_t data;
161 	struct nameidata *ndp;
162 	struct thread *td;
163 {
164 	struct vnode *devvp;	  /* vnode for blk device to mount */
165 	struct msdosfs_args args; /* will hold data from mount request */
166 	/* msdosfs specific mount control block */
167 	struct msdosfsmount *pmp = NULL;
168 	size_t size;
169 	int error, flags;
170 	mode_t accessmode;
171 
172 	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
173 	if (error)
174 		return (error);
175 	if (args.magic != MSDOSFS_ARGSMAGIC)
176 		args.flags = 0;
177 	/*
178 	 * If updating, check whether changing from read-only to
179 	 * read/write; if there is no device name, that's all we do.
180 	 */
181 	if (mp->mnt_flag & MNT_UPDATE) {
182 		pmp = VFSTOMSDOSFS(mp);
183 		error = 0;
184 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_flag & MNT_RDONLY)) {
185 			flags = WRITECLOSE;
186 			if (mp->mnt_flag & MNT_FORCE)
187 				flags |= FORCECLOSE;
188 			error = vflush(mp, 0, flags);
189 		}
190 		if (!error && (mp->mnt_flag & MNT_RELOAD))
191 			/* not yet implemented */
192 			error = EOPNOTSUPP;
193 		if (error)
194 			return (error);
195 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) && (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
196 			/*
197 			 * If upgrade to read-write by non-root, then verify
198 			 * that user has necessary permissions on the device.
199 			 */
200 			if (suser(td)) {
201 				devvp = pmp->pm_devvp;
202 				vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
203 				error = VOP_ACCESS(devvp, VREAD | VWRITE,
204 						   td->td_ucred, td);
205 				if (error) {
206 					VOP_UNLOCK(devvp, 0, td);
207 					return (error);
208 				}
209 				VOP_UNLOCK(devvp, 0, td);
210 			}
211 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
212 
213 			/* Now that the volume is modifiable, mark it dirty. */
214 			error = markvoldirty(pmp, 1);
215 			if (error)
216 				return (error);
217 		}
218 		if (args.fspec == 0) {
219 #ifdef	__notyet__	/* doesn't work correctly with current mountd	XXX */
220 			if (args.flags & MSDOSFSMNT_MNTOPT) {
221 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
222 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
223 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
224 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
225 			}
226 #endif
227 			/*
228 			 * Process export requests.
229 			 */
230 			return (vfs_export(mp, &args.export));
231 		}
232 	}
233 	/*
234 	 * Not an update, or updating the name: look up the name
235 	 * and verify that it refers to a sensible disk device.
236 	 */
237 	NDINIT(ndp, LOOKUP, FOLLOW, UIO_USERSPACE, args.fspec, td);
238 	error = namei(ndp);
239 	if (error)
240 		return (error);
241 	devvp = ndp->ni_vp;
242 	NDFREE(ndp, NDF_ONLY_PNBUF);
243 
244 	if (!vn_isdisk(devvp, &error)) {
245 		vrele(devvp);
246 		return (error);
247 	}
248 	/*
249 	 * If mount by non-root, then verify that user has necessary
250 	 * permissions on the device.
251 	 */
252 	if (suser(td)) {
253 		accessmode = VREAD;
254 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
255 			accessmode |= VWRITE;
256 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
257 		error = VOP_ACCESS(devvp, accessmode, td->td_ucred, td);
258 		if (error) {
259 			vput(devvp);
260 			return (error);
261 		}
262 		VOP_UNLOCK(devvp, 0, td);
263 	}
264 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
265 		error = mountmsdosfs(devvp, mp, td, &args);
266 #ifdef MSDOSFS_DEBUG		/* only needed for the printf below */
267 		pmp = VFSTOMSDOSFS(mp);
268 #endif
269 	} else {
270 		if (devvp != pmp->pm_devvp)
271 			error = EINVAL;	/* XXX needs translation */
272 		else
273 			vrele(devvp);
274 	}
275 	if (error) {
276 		vrele(devvp);
277 		return (error);
278 	}
279 
280 	error = update_mp(mp, &args);
281 	if (error) {
282 		msdosfs_unmount(mp, MNT_FORCE, td);
283 		return error;
284 	}
285 	(void) copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1,
286 	    &size);
287 	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
288 	(void) msdosfs_statfs(mp, &mp->mnt_stat, td);
289 #ifdef MSDOSFS_DEBUG
290 	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
291 #endif
292 	return (0);
293 }
294 
295 static int
296 mountmsdosfs(devvp, mp, td, argp)
297 	struct vnode *devvp;
298 	struct mount *mp;
299 	struct thread *td;
300 	struct msdosfs_args *argp;
301 {
302 	struct msdosfsmount *pmp;
303 	struct buf *bp;
304 	struct cdev *dev = devvp->v_rdev;
305 	union bootsector *bsp;
306 	struct byte_bpb33 *b33;
307 	struct byte_bpb50 *b50;
308 	struct byte_bpb710 *b710;
309 	u_int8_t SecPerClust;
310 	u_long clusters;
311 	int	ronly, error;
312 
313 	/*
314 	 * Disallow multiple mounts of the same device.
315 	 * Disallow mounting of a device that is currently in use
316 	 * (except for root, which might share swap device for miniroot).
317 	 * Flush out any old buffers remaining from a previous use.
318 	 */
319 	error = vfs_mountedon(devvp);
320 	if (error)
321 		return (error);
322 	if (vcount(devvp) > 1 && devvp != rootvp)
323 		return (EBUSY);
324 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
325 	error = vinvalbuf(devvp, V_SAVE, td->td_ucred, td, 0, 0);
326 	if (error) {
327 		VOP_UNLOCK(devvp, 0, td);
328 		return (error);
329 	}
330 
331 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
332 	/*
333 	 * XXX: open the device with read and write access even if only
334 	 * read access is needed now.  Write access is needed if the
335 	 * filesystem is ever mounted read/write, and we don't change the
336 	 * access mode for remounts.
337 	 */
338 #ifdef notyet
339 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD | FWRITE, FSCRED, td, -1);
340 #else
341 	error = VOP_OPEN(devvp, FREAD | FWRITE, FSCRED, td, -1);
342 #endif
343 	VOP_UNLOCK(devvp, 0, td);
344 	if (error)
345 		return (error);
346 
347 	bp  = NULL; /* both used in error_exit */
348 	pmp = NULL;
349 
350 	/*
351 	 * Read the boot sector of the filesystem, and then check the
352 	 * boot signature.  If not a dos boot sector then error out.
353 	 *
354 	 * NOTE: 2048 is a maximum sector size in current...
355 	 */
356 	error = bread(devvp, 0, 2048, NOCRED, &bp);
357 	if (error)
358 		goto error_exit;
359 	bp->b_flags |= B_AGE;
360 	bsp = (union bootsector *)bp->b_data;
361 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
362 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
363 	b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
364 
365 #ifndef MSDOSFS_NOCHECKSIG
366 	if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
367 	    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
368 		error = EINVAL;
369 		goto error_exit;
370 	}
371 #endif
372 
373 	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK | M_ZERO);
374 	pmp->pm_mountp = mp;
375 
376 	/*
377 	 * Compute several useful quantities from the bpb in the
378 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
379 	 * the fields that are different between dos 5 and dos 3.3.
380 	 */
381 	SecPerClust = b50->bpbSecPerClust;
382 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
383 	if (pmp->pm_BytesPerSec < DEV_BSIZE) {
384 		error = EINVAL;
385 		goto error_exit;
386 	}
387 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
388 	pmp->pm_FATs = b50->bpbFATs;
389 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
390 	pmp->pm_Sectors = getushort(b50->bpbSectors);
391 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
392 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
393 	pmp->pm_Heads = getushort(b50->bpbHeads);
394 	pmp->pm_Media = b50->bpbMedia;
395 
396 	/* calculate the ratio of sector size to DEV_BSIZE */
397 	pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
398 
399 	/* XXX - We should probably check more values here */
400 	if (!pmp->pm_BytesPerSec || !SecPerClust
401 		|| !pmp->pm_Heads
402 #ifdef PC98
403     		|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 255) {
404 #else
405 		|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 63) {
406 #endif
407 		error = EINVAL;
408 		goto error_exit;
409 	}
410 
411 	if (pmp->pm_Sectors == 0) {
412 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
413 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
414 	} else {
415 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
416 		pmp->pm_HugeSectors = pmp->pm_Sectors;
417 	}
418 	if (pmp->pm_HugeSectors > 0xffffffff /
419 	    (pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) {
420 		/*
421 		 * We cannot deal currently with this size of disk
422 		 * due to fileid limitations (see msdosfs_getattr and
423 		 * msdosfs_readdir)
424 		 */
425 		error = EINVAL;
426 		printf("mountmsdosfs(): disk too big, sorry\n");
427 		goto error_exit;
428 	}
429 
430 	if (pmp->pm_RootDirEnts == 0) {
431 		if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
432 		    || bsp->bs710.bsBootSectSig3 != BOOTSIG3
433 		    || pmp->pm_Sectors
434 		    || pmp->pm_FATsecs
435 		    || getushort(b710->bpbFSVers)) {
436 			error = EINVAL;
437 			printf("mountmsdosfs(): bad FAT32 filesystem\n");
438 			goto error_exit;
439 		}
440 		pmp->pm_fatmask = FAT32_MASK;
441 		pmp->pm_fatmult = 4;
442 		pmp->pm_fatdiv = 1;
443 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
444 		if (getushort(b710->bpbExtFlags) & FATMIRROR)
445 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
446 		else
447 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
448 	} else
449 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
450 
451 	/*
452 	 * Check a few values (could do some more):
453 	 * - logical sector size: power of 2, >= block size
454 	 * - sectors per cluster: power of 2, >= 1
455 	 * - number of sectors:   >= 1, <= size of partition
456 	 * - number of FAT sectors: >= 1
457 	 */
458 	if ( (SecPerClust == 0)
459 	  || (SecPerClust & (SecPerClust - 1))
460 	  || (pmp->pm_BytesPerSec < DEV_BSIZE)
461 	  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
462 	  || (pmp->pm_HugeSectors == 0)
463 	  || (pmp->pm_FATsecs == 0)
464 	) {
465 		error = EINVAL;
466 		goto error_exit;
467 	}
468 
469 	pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
470 	pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
471 	pmp->pm_FATsecs     *= pmp->pm_BlkPerSec;
472 	SecPerClust         *= pmp->pm_BlkPerSec;
473 
474 	pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
475 
476 	if (FAT32(pmp)) {
477 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
478 		pmp->pm_firstcluster = pmp->pm_fatblk
479 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
480 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
481 	} else {
482 		pmp->pm_rootdirblk = pmp->pm_fatblk +
483 			(pmp->pm_FATs * pmp->pm_FATsecs);
484 		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
485 				       + DEV_BSIZE - 1)
486 			/ DEV_BSIZE; /* in blocks */
487 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
488 	}
489 
490 	pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
491 	    SecPerClust + 1;
492 	pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */
493 
494 	if (pmp->pm_fatmask == 0) {
495 		if (pmp->pm_maxcluster
496 		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
497 			/*
498 			 * This will usually be a floppy disk. This size makes
499 			 * sure that one fat entry will not be split across
500 			 * multiple blocks.
501 			 */
502 			pmp->pm_fatmask = FAT12_MASK;
503 			pmp->pm_fatmult = 3;
504 			pmp->pm_fatdiv = 2;
505 		} else {
506 			pmp->pm_fatmask = FAT16_MASK;
507 			pmp->pm_fatmult = 2;
508 			pmp->pm_fatdiv = 1;
509 		}
510 	}
511 
512 	clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
513 	if (pmp->pm_maxcluster >= clusters) {
514 		printf("Warning: number of clusters (%ld) exceeds FAT "
515 		    "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
516 		pmp->pm_maxcluster = clusters - 1;
517 	}
518 
519 
520 	if (FAT12(pmp))
521 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
522 	else
523 		pmp->pm_fatblocksize = MSDOSFS_DFLTBSIZE;
524 
525 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
526 	pmp->pm_bnshift = ffs(DEV_BSIZE) - 1;
527 
528 	/*
529 	 * Compute mask and shift value for isolating cluster relative byte
530 	 * offsets and cluster numbers from a file offset.
531 	 */
532 	pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
533 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
534 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
535 
536 	/*
537 	 * Check for valid cluster size
538 	 * must be a power of 2
539 	 */
540 	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
541 		error = EINVAL;
542 		goto error_exit;
543 	}
544 
545 	/*
546 	 * Release the bootsector buffer.
547 	 */
548 	brelse(bp);
549 	bp = NULL;
550 
551 	/*
552 	 * Check FSInfo.
553 	 */
554 	if (pmp->pm_fsinfo) {
555 		struct fsinfo *fp;
556 
557 		if ((error = bread(devvp, pmp->pm_fsinfo, fsi_size(pmp),
558 		    NOCRED, &bp)) != 0)
559 			goto error_exit;
560 		fp = (struct fsinfo *)bp->b_data;
561 		if (!bcmp(fp->fsisig1, "RRaA", 4)
562 		    && !bcmp(fp->fsisig2, "rrAa", 4)
563 		    && !bcmp(fp->fsisig3, "\0\0\125\252", 4)
564 		    && !bcmp(fp->fsisig4, "\0\0\125\252", 4)) {
565 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
566 			if (pmp->pm_nxtfree == 0xffffffff)
567 				pmp->pm_nxtfree = CLUST_FIRST;
568 		} else
569 			pmp->pm_fsinfo = 0;
570 		brelse(bp);
571 		bp = NULL;
572 	}
573 
574 	/*
575 	 * Check and validate (or perhaps invalidate?) the fsinfo structure?
576 	 */
577 	if (pmp->pm_fsinfo && pmp->pm_nxtfree > pmp->pm_maxcluster) {
578 		printf(
579 		"Next free cluster in FSInfo (%lu) exceeds maxcluster (%lu)\n",
580 		    pmp->pm_nxtfree, pmp->pm_maxcluster);
581 		error = EINVAL;
582 		goto error_exit;
583 	}
584 
585 	/*
586 	 * Allocate memory for the bitmap of allocated clusters, and then
587 	 * fill it in.
588 	 */
589 	pmp->pm_inusemap = malloc(howmany(pmp->pm_maxcluster + 1, N_INUSEBITS)
590 				  * sizeof(*pmp->pm_inusemap),
591 				  M_MSDOSFSFAT, M_WAITOK);
592 
593 	/*
594 	 * fillinusemap() needs pm_devvp.
595 	 */
596 	pmp->pm_dev = dev;
597 	pmp->pm_devvp = devvp;
598 
599 	/*
600 	 * Have the inuse map filled in.
601 	 */
602 	if ((error = fillinusemap(pmp)) != 0)
603 		goto error_exit;
604 
605 	/*
606 	 * If they want fat updates to be synchronous then let them suffer
607 	 * the performance degradation in exchange for the on disk copy of
608 	 * the fat being correct just about all the time.  I suppose this
609 	 * would be a good thing to turn on if the kernel is still flakey.
610 	 */
611 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
612 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
613 
614 	/*
615 	 * Finish up.
616 	 */
617 	if (ronly)
618 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
619 	else {
620 		/* Mark the volume dirty while it is mounted read/write. */
621 		if ((error = markvoldirty(pmp, 1)) != 0)
622 			goto error_exit;
623 		pmp->pm_fmod = 1;
624 	}
625 	mp->mnt_data = (qaddr_t) pmp;
626 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
627 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
628 	mp->mnt_flag |= MNT_LOCAL;
629 	devvp->v_rdev->si_mountpoint = mp;
630 
631 	return 0;
632 
633 error_exit:
634 	if (bp)
635 		brelse(bp);
636 	/* XXX: see comment above VOP_OPEN. */
637 #ifdef notyet
638 	(void)VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE, NOCRED, td);
639 #else
640 	(void)VOP_CLOSE(devvp, FREAD | FWRITE, NOCRED, td);
641 #endif
642 	if (pmp) {
643 		if (pmp->pm_inusemap)
644 			free(pmp->pm_inusemap, M_MSDOSFSFAT);
645 		free(pmp, M_MSDOSFSMNT);
646 		mp->mnt_data = (qaddr_t)0;
647 	}
648 	return (error);
649 }
650 
651 /*
652  * Unmount the filesystem described by mp.
653  */
654 static int
655 msdosfs_unmount(mp, mntflags, td)
656 	struct mount *mp;
657 	int mntflags;
658 	struct thread *td;
659 {
660 	struct msdosfsmount *pmp;
661 	int error, flags;
662 
663 	flags = 0;
664 	if (mntflags & MNT_FORCE)
665 		flags |= FORCECLOSE;
666 	error = vflush(mp, 0, flags);
667 	if (error)
668 		return error;
669 	pmp = VFSTOMSDOSFS(mp);
670 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
671 		if (pmp->pm_w2u)
672 			msdosfs_iconv->close(pmp->pm_w2u);
673 		if (pmp->pm_u2w)
674 			msdosfs_iconv->close(pmp->pm_u2w);
675 		if (pmp->pm_d2u)
676 			msdosfs_iconv->close(pmp->pm_d2u);
677 		if (pmp->pm_u2d)
678 			msdosfs_iconv->close(pmp->pm_u2d);
679 	}
680 	pmp->pm_devvp->v_rdev->si_mountpoint = NULL;
681 
682 	/* If the volume was mounted read/write, mark it clean now. */
683 	if ((pmp->pm_flags & MSDOSFSMNT_RONLY) == 0) {
684 		error = markvoldirty(pmp, 0);
685 		if (error && (flags & FORCECLOSE) == 0)
686 			return (error);
687 	}
688 #ifdef MSDOSFS_DEBUG
689 	{
690 		struct vnode *vp = pmp->pm_devvp;
691 
692 		VI_LOCK(vp);
693 		printf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
694 		printf("iflag %08lx, usecount %d, writecount %d, holdcnt %ld\n",
695 		    vp->vi_flag, vp->v_usecount, vp->v_writecount,
696 		    vp->v_holdcnt);
697 		printf("id %lu, mount %p, op %p\n",
698 		    vp->v_id, vp->v_mount, vp->v_op);
699 		printf("freef %p, freeb %p, mount %p\n",
700 		    TAILQ_NEXT(vp, v_freelist), vp->v_freelist.tqe_prev,
701 		    vp->v_mount);
702 		printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n",
703 		    TAILQ_FIRST(&vp->v_cleanblkhd),
704 		    TAILQ_FIRST(&vp->v_dirtyblkhd),
705 		    vp->v_numoutput, vp->v_type);
706 		printf("union %p, tag %s, data[0] %08x, data[1] %08x\n",
707 		    vp->v_socket, vp->v_tag,
708 		    ((u_int *)vp->v_data)[0],
709 		    ((u_int *)vp->v_data)[1]);
710 		VI_UNLOCK(vp);
711 	}
712 #endif
713 	/* XXX: see comment above VOP_OPEN. */
714 #ifdef notyet
715 	error = VOP_CLOSE(pmp->pm_devvp,
716 	    (pmp->pm_flags & MSDOSFSMNT_RONLY) ? FREAD : FREAD | FWRITE,
717 	    NOCRED, td);
718 #else
719 	error = VOP_CLOSE(pmp->pm_devvp, FREAD | FWRITE, NOCRED, td);
720 #endif
721 	vrele(pmp->pm_devvp);
722 	free(pmp->pm_inusemap, M_MSDOSFSFAT);
723 	free(pmp, M_MSDOSFSMNT);
724 	mp->mnt_data = (qaddr_t)0;
725 	mp->mnt_flag &= ~MNT_LOCAL;
726 	return (error);
727 }
728 
729 static int
730 msdosfs_root(mp, vpp)
731 	struct mount *mp;
732 	struct vnode **vpp;
733 {
734 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
735 	struct denode *ndep;
736 	int error;
737 
738 #ifdef MSDOSFS_DEBUG
739 	printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
740 #endif
741 	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
742 	if (error)
743 		return (error);
744 	*vpp = DETOV(ndep);
745 	return (0);
746 }
747 
748 static int
749 msdosfs_statfs(mp, sbp, td)
750 	struct mount *mp;
751 	struct statfs *sbp;
752 	struct thread *td;
753 {
754 	struct msdosfsmount *pmp;
755 
756 	pmp = VFSTOMSDOSFS(mp);
757 	sbp->f_bsize = pmp->pm_bpcluster;
758 	sbp->f_iosize = pmp->pm_bpcluster;
759 	sbp->f_blocks = pmp->pm_maxcluster + 1;
760 	sbp->f_bfree = pmp->pm_freeclustercount;
761 	sbp->f_bavail = pmp->pm_freeclustercount;
762 	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
763 	sbp->f_ffree = 0;	/* what to put in here? */
764 	if (sbp != &mp->mnt_stat) {
765 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
766 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
767 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
768 	}
769 	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
770 	return (0);
771 }
772 
773 static int
774 msdosfs_sync(mp, waitfor, cred, td)
775 	struct mount *mp;
776 	int waitfor;
777 	struct ucred *cred;
778 	struct thread *td;
779 {
780 	struct vnode *vp, *nvp;
781 	struct denode *dep;
782 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
783 	int error, allerror = 0;
784 
785 	/*
786 	 * If we ever switch to not updating all of the fats all the time,
787 	 * this would be the place to update them from the first one.
788 	 */
789 	if (pmp->pm_fmod != 0) {
790 		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
791 			panic("msdosfs_sync: rofs mod");
792 		else {
793 			/* update fats here */
794 		}
795 	}
796 	/*
797 	 * Write back each (modified) denode.
798 	 */
799 	MNT_ILOCK(mp);
800 loop:
801 	for (vp = TAILQ_FIRST(&mp->mnt_nvnodelist); vp != NULL; vp = nvp) {
802 		/*
803 		 * If the vnode that we are about to sync is no longer
804 		 * associated with this mount point, start over.
805 		 */
806 		if (vp->v_mount != mp)
807 			goto loop;
808 		nvp = TAILQ_NEXT(vp, v_nmntvnodes);
809 
810 		VI_LOCK(vp);
811 		if (vp->v_iflag & VI_XLOCK) {
812 			VI_UNLOCK(vp);
813 			continue;
814 		}
815 		MNT_IUNLOCK(mp);
816 		dep = VTODE(vp);
817 		if (vp->v_type == VNON ||
818 		    ((dep->de_flag &
819 		    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
820 		    (TAILQ_EMPTY(&vp->v_dirtyblkhd) || waitfor == MNT_LAZY))) {
821 			VI_UNLOCK(vp);
822 			MNT_ILOCK(mp);
823 			continue;
824 		}
825 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
826 		if (error) {
827 			MNT_ILOCK(mp);
828 			if (error == ENOENT)
829 				goto loop;
830 			continue;
831 		}
832 		error = VOP_FSYNC(vp, cred, waitfor, td);
833 		if (error)
834 			allerror = error;
835 		VOP_UNLOCK(vp, 0, td);
836 		vrele(vp);
837 		MNT_ILOCK(mp);
838 	}
839 	MNT_IUNLOCK(mp);
840 
841 	/*
842 	 * Flush filesystem control info.
843 	 */
844 	if (waitfor != MNT_LAZY) {
845 		vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY, td);
846 		error = VOP_FSYNC(pmp->pm_devvp, cred, waitfor, td);
847 		if (error)
848 			allerror = error;
849 		VOP_UNLOCK(pmp->pm_devvp, 0, td);
850 	}
851 	return (allerror);
852 }
853 
854 static int
855 msdosfs_fhtovp(mp, fhp, vpp)
856 	struct mount *mp;
857 	struct fid *fhp;
858 	struct vnode **vpp;
859 {
860 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
861 	struct defid *defhp = (struct defid *) fhp;
862 	struct denode *dep;
863 	int error;
864 
865 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
866 	if (error) {
867 		*vpp = NULLVP;
868 		return (error);
869 	}
870 	*vpp = DETOV(dep);
871 	return (0);
872 }
873 
874 static int
875 msdosfs_vptofh(vp, fhp)
876 	struct vnode *vp;
877 	struct fid *fhp;
878 {
879 	struct denode *dep;
880 	struct defid *defhp;
881 
882 	dep = VTODE(vp);
883 	defhp = (struct defid *)fhp;
884 	defhp->defid_len = sizeof(struct defid);
885 	defhp->defid_dirclust = dep->de_dirclust;
886 	defhp->defid_dirofs = dep->de_diroffset;
887 	/* defhp->defid_gen = dep->de_gen; */
888 	return (0);
889 }
890 
891 static struct vfsops msdosfs_vfsops = {
892 	.vfs_fhtovp =		msdosfs_fhtovp,
893 	.vfs_init =		msdosfs_init,
894 	.vfs_mount =		msdosfs_mount,
895 	.vfs_root =		msdosfs_root,
896 	.vfs_statfs =		msdosfs_statfs,
897 	.vfs_sync =		msdosfs_sync,
898 	.vfs_uninit =		msdosfs_uninit,
899 	.vfs_unmount =		msdosfs_unmount,
900 	.vfs_vptofh =		msdosfs_vptofh,
901 };
902 
903 VFS_SET(msdosfs_vfsops, msdosfs, 0);
904 MODULE_VERSION(msdosfs, 1);
905