xref: /dflybsd-src/sys/vfs/msdosfs/msdosfs_vfsops.c (revision d9bb5dfdc3905237fb704584b71c9e0a9627656c)
1 /* $FreeBSD$ */
2 /*	$NetBSD: msdosfs_vfsops.c,v 1.51 1997/11/17 15:36:58 ws Exp $	*/
3 
4 /*-
5  * SPDX-License-Identifier: BSD-4-Clause
6  *
7  * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
8  * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
9  * All rights reserved.
10  * Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by TooLs GmbH.
23  * 4. The name of TooLs GmbH may not be used to endorse or promote products
24  *    derived from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
32  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
33  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
34  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
35  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 /*-
38  * Written by Paul Popelka (paulp@uts.amdahl.com)
39  *
40  * You can do anything you want with this software, just don't say you wrote
41  * it, and don't remove this notice.
42  *
43  * This software is provided "as is".
44  *
45  * The author supplies this software to be publicly redistributed on the
46  * understanding that the author is not responsible for the correct
47  * functioning of this software in any circumstances and is not liable for
48  * any damages caused by this software.
49  *
50  * October 1992
51  */
52 
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/conf.h>
56 #include <sys/proc.h>
57 #include <sys/nlookup.h>
58 #include <sys/kernel.h>
59 #include <sys/vnode.h>
60 #include <sys/iconv.h>
61 #include <sys/mount.h>
62 #include <sys/buf.h>
63 #include <sys/fcntl.h>
64 #include <sys/malloc.h>
65 #include <sys/stat.h>				/* defines ALLPERMS */
66 #include <vm/vm_zone.h>
67 
68 #include <sys/buf2.h>
69 
70 #include "bpb.h"
71 #include "bootsect.h"
72 #include "direntry.h"
73 #include "denode.h"
74 #include "msdosfsmount.h"
75 #include "fat.h"
76 
77 extern struct vop_ops msdosfs_vnode_vops;
78 struct iconv_functions *msdosfs_iconv;
79 
80 #define MSDOSFS_DFLTBSIZE       4096
81 #define ENCODING_UNICODE        "UTF-16BE"
82 #if 1 /*def PC98*/
83 /*
84  * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
85  *       garbage or a random value :-{
86  *       If you want to use that broken-signatured media, define the
87  *       following symbol even though PC/AT.
88  *       (ex. mount PC-98 DOS formatted FD on PC/AT)
89  */
90 #define	MSDOSFS_NOCHECKSIG
91 #endif
92 
93 MALLOC_DEFINE(M_MSDOSFSMNT, "MSDOSFS mount", "MSDOSFS mount structure");
94 static MALLOC_DEFINE(M_MSDOSFSFAT, "MSDOSFS FAT", "MSDOSFS file allocation table");
95 
96 static int mountmsdosfs(struct vnode *devvp, struct mount *mp,
97     struct msdosfs_args *argp);
98 static int msdosfs_root(struct mount *, struct vnode **);
99 static int msdosfs_statfs(struct mount *, struct statfs *, struct ucred *);
100 static int msdosfs_unmount(struct mount *, int);
101 
102 static int
103 update_mp(struct mount *mp, struct msdosfs_args *argp)
104 {
105 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
106 	int error;
107 	char cs_local[ICONV_CSNMAXLEN];
108 	char cs_dos[ICONV_CSNMAXLEN];
109 
110 	pmp->pm_gid = argp->gid;
111 	pmp->pm_uid = argp->uid;
112 	pmp->pm_mask = argp->mask & ALLPERMS;
113 	pmp->pm_dirmask = argp->dirmask & ALLPERMS;
114 	pmp->pm_flags |= argp->flags & MSDOSFSMNT_MNTOPT;
115 
116 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
117 		memcpy(cs_local, argp->cs_local, sizeof(cs_local));
118 		memcpy(cs_dos, argp->cs_dos, sizeof(cs_dos));
119 		kprintf("local: %s dos: %s\n",argp->cs_local, argp->cs_dos);
120 		error = msdosfs_iconv->open(cs_local, ENCODING_UNICODE,
121 					    &pmp->pm_w2u);
122 		if(error)
123 			return error;
124 		error = msdosfs_iconv->open(ENCODING_UNICODE, cs_local,
125 					    &pmp->pm_u2w);
126 		if(error)
127 			return error;
128 		error = msdosfs_iconv->open(cs_dos, cs_local, &pmp->pm_u2d);
129 		if(error)
130 			return error;
131 		error = msdosfs_iconv->open(cs_local, cs_dos, &pmp->pm_d2u);
132 		if(error)
133 			return error;
134 	}
135 
136 	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
137 		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
138 	else
139 		pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
140 	return 0;
141 }
142 
143 /*
144  * mp - path - addr in user space of mount point (ie /usr or whatever)
145  * data - addr in user space of mount params including the name of the block
146  * special file to treat as a filesystem.
147  */
148 static int
149 msdosfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
150 {
151 	struct vnode *devvp;	  /* vnode for blk device to mount */
152 	struct msdosfs_args args; /* will hold data from mount request */
153 	/* msdosfs specific mount control block */
154 	struct msdosfsmount *pmp = NULL;
155 	size_t size;
156 	int error, flags;
157 	mode_t accessmode;
158 	struct nlookupdata nd;
159 
160 	error = copyin(data, (caddr_t)&args, sizeof(struct msdosfs_args));
161 	if (error)
162 		return (error);
163 	/*
164 	 * If updating, check whether changing from read-only to
165 	 * read/write; if there is no device name, that's all we do.
166 	 */
167 	if (mp->mnt_flag & MNT_UPDATE) {
168 		pmp = VFSTOMSDOSFS(mp);
169 		error = 0;
170 		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
171 		    (mp->mnt_flag & MNT_RDONLY)) {
172 			flags = WRITECLOSE;
173 			if (mp->mnt_flag & MNT_FORCE)
174 				flags |= FORCECLOSE;
175 			error = vflush(mp, 0, flags);
176 			if (error == 0) {
177 				devvp = pmp->pm_devvp;
178 				vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
179 				VOP_OPEN(devvp, FREAD, FSCRED, NULL);
180 				VOP_CLOSE(devvp, FREAD|FWRITE, NULL);
181 				vn_unlock(devvp);
182 				pmp->pm_flags |= MSDOSFSMNT_RONLY;
183 			}
184 		}
185 		if (!error && (mp->mnt_flag & MNT_RELOAD))
186 			error = EOPNOTSUPP; /* not yet implemented */
187 		if (error)
188 			return (error);
189 		if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
190 		    (mp->mnt_kern_flag & MNTK_WANTRDWR)) {
191 			/*
192 			 * If upgrade to read-write by non-root, then verify
193 			 * that user has necessary permissions on the device.
194 			 */
195 			devvp = pmp->pm_devvp;
196 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
197 			if (cred->cr_uid != 0) {
198 				error = VOP_EACCESS(devvp, VREAD | VWRITE,
199 						    cred);
200 				if (error) {
201 					vn_unlock(devvp);
202 					return (error);
203 				}
204 			}
205 			VOP_OPEN(devvp, FREAD|FWRITE, FSCRED, NULL);
206 			VOP_CLOSE(devvp, FREAD, NULL);
207 			vn_unlock(devvp);
208 			pmp->pm_flags &= ~MSDOSFSMNT_RONLY;
209 		}
210 		if (args.fspec == NULL) {
211 #ifdef __notyet__	/* doesn't work correctly with current mountd XXX */
212 			if (args.flags & MSDOSFSMNT_MNTOPT) {
213 				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
214 				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
215 				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
216 					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
217 			}
218 #endif
219 			/*
220 			 * Process export requests.
221 			 */
222 			return (vfs_export(mp, &pmp->pm_export, &args.export));
223 		}
224 	}
225 	/*
226 	 * Not an update, or updating the name: look up the name
227 	 * and verify that it refers to a sensible disk device.
228 	 */
229 	devvp = NULL;
230 	error = nlookup_init(&nd, args.fspec, UIO_USERSPACE, NLC_FOLLOW);
231 	if (error == 0)
232 		error = nlookup(&nd);
233 	if (error == 0)
234 		error = cache_vref(&nd.nl_nch, nd.nl_cred, &devvp);
235 	nlookup_done(&nd);
236 	if (error)
237 		return (error);
238 
239 	if (!vn_isdisk(devvp, &error)) {
240 		vrele(devvp);
241 		return (error);
242 	}
243 	/*
244 	 * If mount by non-root, then verify that user has necessary
245 	 * permissions on the device.
246 	 */
247 	if (cred->cr_uid != 0) {
248 		accessmode = VREAD;
249 		if ((mp->mnt_flag & MNT_RDONLY) == 0)
250 			accessmode |= VWRITE;
251 		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
252 		error = VOP_EACCESS(devvp, accessmode, cred);
253 		if (error) {
254 			vput(devvp);
255 			return (error);
256 		}
257 		vn_unlock(devvp);
258 	}
259 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
260 		error = mountmsdosfs(devvp, mp, &args);
261 #ifdef MSDOSFS_DEBUG		/* only needed for the kprintf below */
262 		pmp = VFSTOMSDOSFS(mp);
263 #endif
264 	} else {
265 		if (devvp != pmp->pm_devvp)
266 			error = EINVAL;	/* XXX needs translation */
267 		else
268 			vrele(devvp);
269 	}
270 	if (error) {
271 		vrele(devvp);
272 		return (error);
273 	}
274 
275 	error = update_mp(mp, &args);
276 	if (error) {
277 		msdosfs_unmount(mp, MNT_FORCE);
278 		return error;
279 	}
280 
281 	copyinstr(args.fspec, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
282 	memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size);
283 	msdosfs_statfs(mp, &mp->mnt_stat, cred);
284 #ifdef MSDOSFS_DEBUG
285 	kprintf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n",
286 		mp, pmp, pmp->pm_inusemap);
287 #endif
288 	return (0);
289 }
290 
291 static int
292 mountmsdosfs(struct vnode *devvp, struct mount *mp, struct msdosfs_args *argp)
293 {
294 	struct msdosfsmount *pmp;
295 	struct buf *bp;
296 	cdev_t dev;
297 	union bootsector *bsp;
298 	struct byte_bpb33 *b33;
299 	struct byte_bpb50 *b50;
300 	struct byte_bpb710 *b710;
301 	uint8_t SecPerClust;
302 	u_long clusters;
303 	int ronly, error;
304 
305 	/*
306 	 * Disallow multiple mounts of the same device.
307 	 * Disallow mounting of a device that is currently in use
308 	 * Flush out any old buffers remaining from a previous use.
309 	 */
310 	error = vfs_mountedon(devvp);
311 	if (error)
312 		return (error);
313 	if (vcount(devvp) > 0)
314 		return (EBUSY);
315 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
316 	error = vinvalbuf(devvp, V_SAVE, 0, 0);
317 	vn_unlock(devvp);
318 	if (error)
319 		return (error);
320 
321 	ronly = (mp->mnt_flag & MNT_RDONLY) != 0;
322 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
323 	error = VOP_OPEN(devvp, ronly ? FREAD : FREAD|FWRITE, FSCRED, NULL);
324 	vn_unlock(devvp);
325 	if (error)
326 		return (error);
327 	dev = devvp->v_rdev;
328 	bp  = NULL; /* both used in error_exit */
329 	pmp = NULL;
330 
331 	/*
332 	 * Read the boot sector of the filesystem, and then check the
333 	 * boot signature.  If not a dos boot sector then error out.
334 	 *
335 	 * NOTE: 2048 is a maximum sector size in current...
336 	 */
337 	error = bread(devvp, 0, 2048, &bp);
338 	if (error)
339 		goto error_exit;
340 	bp->b_flags |= B_AGE;
341 	bsp = (union bootsector *)bp->b_data;
342 	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
343 	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
344 	b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
345 
346 #ifndef MSDOSFS_NOCHECKSIG
347 	if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
348 	    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
349 		error = EINVAL;
350 		goto error_exit;
351 	}
352 #endif
353 
354 	pmp = kmalloc(sizeof(*pmp), M_MSDOSFSMNT, M_WAITOK | M_ZERO);
355 	pmp->pm_mountp = mp;
356 
357 	/*
358 	 * Compute several useful quantities from the bpb in the
359 	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
360 	 * the fields that are different between dos 5 and dos 3.3.
361 	 */
362 	SecPerClust = b50->bpbSecPerClust;
363 	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
364 	if (pmp->pm_BytesPerSec < DEV_BSIZE) {
365 		error = EINVAL;
366 		goto error_exit;
367 	}
368 	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
369 	pmp->pm_FATs = b50->bpbFATs;
370 	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
371 	pmp->pm_Sectors = getushort(b50->bpbSectors);
372 	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
373 	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
374 	pmp->pm_Heads = getushort(b50->bpbHeads);
375 	pmp->pm_Media = b50->bpbMedia;
376 
377 	/* calculate the ratio of sector size to DEV_BSIZE */
378 	pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
379 
380 	/*
381 	 * We don't check pm_Heads nor pm_SecPerTrack, because
382 	 * these may not be set for EFI file systems. We don't
383 	 * use these anyway, so we're unaffected if they are
384 	 * invalid.
385 	 */
386 	if (!pmp->pm_BytesPerSec || !SecPerClust) {
387 		error = EINVAL;
388 		goto error_exit;
389 	}
390 
391 	if (pmp->pm_Sectors == 0) {
392 		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
393 		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
394 	} else {
395 		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
396 		pmp->pm_HugeSectors = pmp->pm_Sectors;
397 	}
398 
399 	if (pmp->pm_RootDirEnts == 0) {
400 		if (pmp->pm_FATsecs
401 		    || getushort(b710->bpbFSVers)) {
402 			error = EINVAL;
403 			kprintf("mountmsdosfs(): bad FAT32 filesystem\n");
404 			goto error_exit;
405 		}
406 		pmp->pm_fatmask = FAT32_MASK;
407 		pmp->pm_fatmult = 4;
408 		pmp->pm_fatdiv = 1;
409 		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
410 		if (getushort(b710->bpbExtFlags) & FATMIRROR)
411 			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
412 		else
413 			pmp->pm_flags |= MSDOSFS_FATMIRROR;
414 	} else
415 		pmp->pm_flags |= MSDOSFS_FATMIRROR;
416 
417 	/*
418 	 * Check a few values (could do some more):
419 	 * - logical sector size: power of 2, >= block size
420 	 * - sectors per cluster: power of 2, >= 1
421 	 * - number of sectors:   >= 1, <= size of partition
422 	 * - number of FAT sectors: >= 1
423 	 */
424 	if ( (SecPerClust == 0)
425 	  || (SecPerClust & (SecPerClust - 1))
426 	  || (pmp->pm_BytesPerSec < DEV_BSIZE)
427 	  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
428 	  || (pmp->pm_HugeSectors == 0)
429 	  || (pmp->pm_FATsecs == 0)
430 	  || (SecPerClust * pmp->pm_BlkPerSec > MAXBSIZE / DEV_BSIZE)) {
431 		error = EINVAL;
432 		goto error_exit;
433 	}
434 
435 	pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
436 	pmp->pm_HiddenSects *= pmp->pm_BlkPerSec;	/* XXX not used? */
437 	pmp->pm_FATsecs     *= pmp->pm_BlkPerSec;
438 	SecPerClust         *= pmp->pm_BlkPerSec;
439 
440 	pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
441 
442 	if (FAT32(pmp)) {
443 		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
444 		pmp->pm_firstcluster = pmp->pm_fatblk
445 			+ (pmp->pm_FATs * pmp->pm_FATsecs);
446 		pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
447 	} else {
448 		pmp->pm_rootdirblk = pmp->pm_fatblk +
449 			(pmp->pm_FATs * pmp->pm_FATsecs);
450 		pmp->pm_rootdirsize = howmany(pmp->pm_RootDirEnts *
451 			sizeof(struct direntry), DEV_BSIZE); /* in blocks */
452 		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
453 	}
454 
455 	pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
456 	    SecPerClust + 1;
457 
458 	if (pmp->pm_fatmask == 0) {
459 		if (pmp->pm_maxcluster
460 		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
461 			/*
462 			 * This will usually be a floppy disk. This size makes
463 			 * sure that one FAT entry will not be split across
464 			 * multiple blocks.
465 			 */
466 			pmp->pm_fatmask = FAT12_MASK;
467 			pmp->pm_fatmult = 3;
468 			pmp->pm_fatdiv = 2;
469 		} else {
470 			pmp->pm_fatmask = FAT16_MASK;
471 			pmp->pm_fatmult = 2;
472 			pmp->pm_fatdiv = 1;
473 		}
474 	}
475 
476 	clusters = ((pmp->pm_FATsecs * DEV_BSIZE) / pmp->pm_fatmult) *
477 		pmp->pm_fatdiv;
478 	if (pmp->pm_maxcluster >= clusters) {
479 		kprintf("Warning: number of clusters (%ld) exceeds FAT "
480 		    "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
481 		pmp->pm_maxcluster = clusters - 1;
482 	}
483 
484 	if (FAT12(pmp))
485 		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
486 	else
487 		pmp->pm_fatblocksize = MSDOSFS_DFLTBSIZE;
488 
489 	pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
490 	pmp->pm_bnshift = DEV_BSHIFT;
491 
492 	/*
493 	 * Compute mask and shift value for isolating cluster relative byte
494 	 * offsets and cluster numbers from a file offset.
495 	 */
496 	pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
497 	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
498 	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
499 
500 	/*
501 	 * Check for valid cluster size
502 	 * must be a power of 2
503 	 */
504 	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
505 		error = EINVAL;
506 		goto error_exit;
507 	}
508 
509 	/*
510 	 * Release the bootsector buffer.
511 	 */
512 	bp->b_flags |= B_RELBUF;
513 	brelse(bp);
514 	bp = NULL;
515 
516 	/*
517 	 * Check the fsinfo sector if we have one.  Silently fix up our
518 	 * in-core copy of fp->fsinxtfree if it is unknown (0xffffffff)
519 	 * or too large.  Ignore fp->fsinfree for now, since we need to
520 	 * read the entire FAT anyway to fill the inuse map.
521 	 */
522 	if (pmp->pm_fsinfo) {
523 		struct fsinfo *fp;
524 
525 		if ((error = bread(devvp, de_bn2doff(pmp, pmp->pm_fsinfo),
526 		    pmp->pm_BytesPerSec, &bp)) != 0)
527 			goto error_exit;
528 		fp = (struct fsinfo *)bp->b_data;
529 		if (!memcmp(fp->fsisig1, "RRaA", 4) &&
530 		    !memcmp(fp->fsisig2, "rrAa", 4) &&
531 		    !memcmp(fp->fsisig3, "\0\0\125\252", 4)) {
532 			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
533 			if (pmp->pm_nxtfree > pmp->pm_maxcluster)
534 				pmp->pm_nxtfree = CLUST_FIRST;
535 		} else
536 			pmp->pm_fsinfo = 0;
537 		bp->b_flags |= B_RELBUF;
538 		brelse(bp);
539 		bp = NULL;
540 	}
541 
542 	/*
543 	 * Finish initializing pmp->pm_nxtfree (just in case the first few
544 	 * sectors aren't properly reserved in the FAT).  This completes
545 	 * the fixup for fp->fsinxtfree, and fixes up the zero-initialized
546 	 * value if there is no fsinfo.  We will use pmp->pm_nxtfree
547 	 * internally even if there is no fsinfo.
548 	 */
549 	if (pmp->pm_nxtfree < CLUST_FIRST)
550 		pmp->pm_nxtfree = CLUST_FIRST;
551 
552 	/*
553 	 * Allocate memory for the bitmap of allocated clusters, and then
554 	 * fill it in.
555 	 */
556 	pmp->pm_inusemap = kmalloc(howmany(pmp->pm_maxcluster + 1, N_INUSEBITS)
557 				   * sizeof(*pmp->pm_inusemap),
558 				   M_MSDOSFSFAT, M_WAITOK);
559 
560 	/*
561 	 * fillinusemap() needs pm_devvp.
562 	 */
563 	pmp->pm_devvp = devvp;
564 	pmp->pm_dev = dev;
565 
566 	/*
567 	 * Have the inuse map filled in.
568 	 */
569 	MSDOSFS_LOCK_MP(pmp);
570 	error = fillinusemap(pmp);
571 	MSDOSFS_UNLOCK_MP(pmp);
572 	if (error != 0)
573 		goto error_exit;
574 
575 	/*
576 	 * If they want FAT updates to be synchronous then let them suffer
577 	 * the performance degradation in exchange for the on disk copy of
578 	 * the FAT being correct just about all the time.  I suppose this
579 	 * would be a good thing to turn on if the kernel is still flakey.
580 	 */
581 	if (mp->mnt_flag & MNT_SYNCHRONOUS)
582 		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
583 
584 	/*
585 	 * Finish up.
586 	 */
587 	if (ronly)
588 		pmp->pm_flags |= MSDOSFSMNT_RONLY;
589 	else
590 		pmp->pm_fmod = 1;
591 	mp->mnt_data = (qaddr_t) pmp;
592 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
593 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
594 	mp->mnt_flag |= MNT_LOCAL;
595 	vfs_add_vnodeops(mp, &msdosfs_vnode_vops, &mp->mnt_vn_norm_ops);
596 	dev->si_mountpoint = mp;
597 
598 	return (0);
599 
600 error_exit:
601 	if (bp) {
602 		bp->b_flags |= B_RELBUF;
603 		brelse(bp);
604 	}
605 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
606 	VOP_CLOSE(devvp, ronly ? FREAD : FREAD | FWRITE, NULL);
607 	vn_unlock(devvp);
608 	if (pmp) {
609 		if (pmp->pm_inusemap)
610 			kfree(pmp->pm_inusemap, M_MSDOSFSFAT);
611 		kfree(pmp, M_MSDOSFSMNT);
612 		mp->mnt_data = (qaddr_t)0;
613 	}
614 	return (error);
615 }
616 
617 /*
618  * Unmount the filesystem described by mp.
619  */
620 static int
621 msdosfs_unmount(struct mount *mp, int mntflags)
622 {
623 	struct msdosfsmount *pmp;
624 	int error, flags;
625 #ifdef MSDOSFS_DEBUG
626 	struct vnode *vp;
627 #endif
628 	flags = 0;
629 	if (mntflags & MNT_FORCE)
630 		flags |= FORCECLOSE;
631 	error = vflush(mp, 0, flags);
632 	if (error)
633 		return error;
634 
635 	pmp = VFSTOMSDOSFS(mp);
636 	pmp->pm_devvp->v_rdev->si_mountpoint = NULL;
637 
638 	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
639 		if (pmp->pm_w2u)
640 			msdosfs_iconv->close(pmp->pm_w2u);
641 		if (pmp->pm_u2w)
642 			msdosfs_iconv->close(pmp->pm_u2w);
643 		if (pmp->pm_d2u)
644 			msdosfs_iconv->close(pmp->pm_d2u);
645 		if (pmp->pm_u2d)
646 			msdosfs_iconv->close(pmp->pm_u2d);
647 	}
648 
649 #ifdef MSDOSFS_DEBUG
650 	vp = pmp->pm_devvp;
651 	kprintf("msdosfs_umount(): just before calling VOP_CLOSE()\n");
652 	kprintf("flag %08x, refcnt 0x%08x, writecount %d, auxrefs 0x%08x\n",
653 		vp->v_flag, vp->v_refcnt, vp->v_writecount, vp->v_auxrefs);
654 	kprintf("mount %p, op %p\n", vp->v_mount, vp->v_ops);
655 	kprintf("mount %p\n", vp->v_mount);
656 	kprintf("cleanblkhd %p, dirtyblkhd %p, numoutput %d, type %d\n",
657 		RB_ROOT(&vp->v_rbclean_tree), RB_ROOT(&vp->v_rbdirty_tree),
658 		bio_track_active(&vp->v_track_write), vp->v_type);
659 	kprintf("union %p, tag %d, data[0] %08x, data[1] %08x\n",
660 		vp->v_socket, vp->v_tag, ((u_int *)vp->v_data)[0],
661 		((u_int *)vp->v_data)[1]);
662 #endif
663 
664 	vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
665 	error = VOP_CLOSE(pmp->pm_devvp,
666 		    pmp->pm_flags & MSDOSFSMNT_RONLY ? FREAD : FREAD | FWRITE,
667 		    NULL);
668 	vn_unlock(pmp->pm_devvp);
669 	vrele(pmp->pm_devvp);
670 	kfree(pmp->pm_inusemap, M_MSDOSFSFAT);
671 	kfree(pmp, M_MSDOSFSMNT);
672 	mp->mnt_data = (qaddr_t)0;
673 	mp->mnt_flag &= ~MNT_LOCAL;
674 	return (error);
675 }
676 
677 static int
678 msdosfs_root(struct mount *mp, struct vnode **vpp)
679 {
680 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
681 	struct denode *ndep;
682 	int error;
683 
684 	mprintf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
685 	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
686 	if (error)
687 		return (error);
688 	*vpp = DETOV(ndep);
689 	return (0);
690 }
691 
692 static int
693 msdosfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
694 {
695 	struct msdosfsmount *pmp;
696 
697 	pmp = VFSTOMSDOSFS(mp);
698 	sbp->f_bsize = pmp->pm_bpcluster;
699 	sbp->f_iosize = pmp->pm_bpcluster;
700 	sbp->f_blocks = pmp->pm_maxcluster + 1;
701 	sbp->f_bfree = pmp->pm_freeclustercount;
702 	sbp->f_bavail = pmp->pm_freeclustercount;
703 	sbp->f_files = pmp->pm_RootDirEnts;	/* XXX */
704 	sbp->f_ffree = 0;	/* what to put in here? */
705 	if (sbp != &mp->mnt_stat) {
706 		sbp->f_type = mp->mnt_vfc->vfc_typenum;
707 		memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
708 	}
709 	strncpy(sbp->f_fstypename, mp->mnt_vfc->vfc_name, MFSNAMELEN);
710 	return (0);
711 }
712 
713 struct scaninfo {
714 	int rescan;
715 	int allerror;
716 	int waitfor;
717 };
718 
719 static int msdosfs_sync_scan(struct mount *mp, struct vnode *vp, void *data);
720 
721 /*
722  * If we have an FSInfo block, update it.
723  */
724 static int
725 msdosfs_fsiflush(struct msdosfsmount *pmp, int waitfor)
726 {
727 	struct fsinfo *fp;
728 	struct buf *bp;
729 	int error;
730 
731 	MSDOSFS_LOCK_MP(pmp);
732 	if (pmp->pm_fsinfo == 0 || (pmp->pm_flags & MSDOSFS_FSIMOD) == 0) {
733 		error = 0;
734 		goto unlock;
735 	}
736 	error = bread(pmp->pm_devvp, de_bn2doff(pmp, pmp->pm_fsinfo),
737 	    pmp->pm_BytesPerSec, &bp);
738 	if (error != 0) {
739 		brelse(bp);
740 		goto unlock;
741 	}
742 
743 	fp = (struct fsinfo *)bp->b_data;
744 	putulong(fp->fsinfree, pmp->pm_freeclustercount);
745 	putulong(fp->fsinxtfree, pmp->pm_nxtfree);
746 	pmp->pm_flags &= ~MSDOSFS_FSIMOD;
747 	if (waitfor == MNT_WAIT)
748 		error = bwrite(bp);
749 	else
750 		bawrite(bp);
751 unlock:
752 	MSDOSFS_UNLOCK_MP(pmp);
753 	return (error);
754 }
755 
756 static int
757 msdosfs_sync(struct mount *mp, int waitfor)
758 {
759 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
760 	struct scaninfo scaninfo;
761 	int error;
762 
763 	/*
764 	 * If we ever switch to not updating all of the FATs all the time,
765 	 * this would be the place to update them from the first one.
766 	 */
767 	if (pmp->pm_fmod != 0) {
768 		if (pmp->pm_flags & MSDOSFSMNT_RONLY) {
769 			panic("msdosfs_sync: rofs mod");
770 		} else {
771 			/* update FATs here */
772 		}
773 	}
774 	/*
775 	 * Write back each (modified) denode.
776 	 */
777 	scaninfo.allerror = 0;
778 	scaninfo.rescan = 1;
779 	while (scaninfo.rescan) {
780 		scaninfo.rescan = 0;
781 		vmntvnodescan(mp, VMSC_GETVP|VMSC_NOWAIT, NULL,
782 			      msdosfs_sync_scan, &scaninfo);
783 	}
784 
785 	/*
786 	 * Flush filesystem control info.
787 	 */
788 	if ((waitfor & MNT_LAZY) == 0) {
789 		vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY);
790 		if ((error = VOP_FSYNC(pmp->pm_devvp, waitfor, 0)) != 0)
791 			scaninfo.allerror = error;
792 		vn_unlock(pmp->pm_devvp);
793 	}
794 
795 	error = msdosfs_fsiflush(pmp, waitfor);
796 	if (error != 0)
797 		scaninfo.allerror = error;
798 	return (scaninfo.allerror);
799 }
800 
801 static int
802 msdosfs_sync_scan(struct mount *mp, struct vnode *vp, void *data)
803 {
804 	struct scaninfo *info = data;
805 	struct denode *dep;
806 	int error;
807 
808 	dep = VTODE(vp);
809 	if (vp->v_type == VNON || vp->v_type == VBAD ||
810 	    ((dep->de_flag &
811 	    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
812 	    (RB_EMPTY(&vp->v_rbdirty_tree) || (info->waitfor & MNT_LAZY)))) {
813 		return(0);
814 	}
815 	if ((error = VOP_FSYNC(vp, info->waitfor, 0)) != 0)
816 		info->allerror = error;
817 	return(0);
818 }
819 
820 static int
821 msdosfs_fhtovp(struct mount *mp, struct vnode *rootvp,
822 	       struct fid *fhp, struct vnode **vpp)
823 {
824 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
825 	struct defid *defhp = (struct defid *) fhp;
826 	struct denode *dep;
827 	int error;
828 
829 	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
830 	if (error) {
831 		*vpp = NULLVP;
832 		return (error);
833 	}
834 	*vpp = DETOV(dep);
835 	return (0);
836 }
837 
838 static int
839 msdosfs_checkexp(struct mount *mp, struct sockaddr *nam, int *exflagsp,
840 		 struct ucred **credanonp)
841 {
842 	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
843 	struct netcred *np;
844 
845 	np = vfs_export_lookup(mp, &pmp->pm_export, nam);
846 	if (np == NULL)
847 		return (EACCES);
848 	*exflagsp = np->netc_exflags;
849 	*credanonp = &np->netc_anon;
850 	return (0);
851 }
852 
853 static int
854 msdosfs_vptofh(struct vnode *vp, struct fid *fhp)
855 {
856 	struct denode *dep;
857 	struct defid *defhp;
858 
859 	dep = VTODE(vp);
860 	defhp = (struct defid *)fhp;
861 	defhp->defid_len = sizeof(struct defid);
862 	defhp->defid_dirclust = dep->de_dirclust;
863 	defhp->defid_dirofs = dep->de_diroffset;
864 	/* defhp->defid_gen = dep->de_gen; */
865 	return (0);
866 }
867 
868 static struct vfsops msdosfs_vfsops = {
869 	.vfs_mount =		msdosfs_mount,
870 	.vfs_unmount =		msdosfs_unmount,
871 	.vfs_root =		msdosfs_root,
872 	.vfs_statfs =		msdosfs_statfs,
873 	.vfs_sync =		msdosfs_sync,
874 	.vfs_fhtovp =		msdosfs_fhtovp,
875 	.vfs_checkexp =		msdosfs_checkexp,
876 	.vfs_vptofh =		msdosfs_vptofh,
877 	.vfs_init =		msdosfs_init,
878 	.vfs_uninit =		msdosfs_uninit
879 };
880 
881 VFS_SET(msdosfs_vfsops, msdos, 0);
882 MODULE_VERSION(msdos, 1);
883