msdosfs_vfsops.c revision 166340
1/* $FreeBSD: head/sys/fs/msdosfs/msdosfs_vfsops.c 166340 2007-01-30 03:11:45Z rodrigc $ */
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/priv.h>
56#include <sys/proc.h>
57#include <sys/kernel.h>
58#include <sys/vnode.h>
59#include <sys/mount.h>
60#include <sys/bio.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 <sys/iconv.h>
66#include <sys/mutex.h>
67
68#include <fs/msdosfs/bpb.h>
69#include <fs/msdosfs/bootsect.h>
70#include <fs/msdosfs/msdosfsmount.h>
71#include <fs/msdosfs/direntry.h>
72#include <fs/msdosfs/denode.h>
73#include <fs/msdosfs/fat.h>
74
75#include <geom/geom.h>
76#include <geom/geom_vfs.h>
77
78#include "opt_msdosfs.h"
79
80/* List of mount options we support */
81static const char *msdosfs_opts[] = {
82	"from",
83	"export", "force", "sync",
84	"uid", "gid", "mask", "dirmask",
85	"shortname", "shortnames", "longname", "longnames", "nowin95", "win95",
86	"kiconv", "cs_win", "cs_dos", "cs_local", "large",
87	NULL
88};
89
90#define MSDOSFS_DFLTBSIZE       4096
91
92#if 1 /*def PC98*/
93/*
94 * XXX - The boot signature formatted by NEC PC-98 DOS looks like a
95 *       garbage or a random value :-{
96 *       If you want to use that broken-signatured media, define the
97 *       following symbol even though PC/AT.
98 *       (ex. mount PC-98 DOS formatted FD on PC/AT)
99 */
100#define	MSDOSFS_NOCHECKSIG
101#endif
102
103MALLOC_DEFINE(M_MSDOSFSMNT, "msdosfs_mount", "MSDOSFS mount structure");
104static MALLOC_DEFINE(M_MSDOSFSFAT, "msdosfs_fat", "MSDOSFS file allocation table");
105
106struct iconv_functions *msdosfs_iconv = NULL;
107
108static int	update_mp(struct mount *mp, struct thread *td);
109static int	mountmsdosfs(struct vnode *devvp, struct mount *mp,
110		    struct thread *td);
111static vfs_fhtovp_t	msdosfs_fhtovp;
112static vfs_mount_t	msdosfs_mount;
113static vfs_root_t	msdosfs_root;
114static vfs_statfs_t	msdosfs_statfs;
115static vfs_sync_t	msdosfs_sync;
116static vfs_unmount_t	msdosfs_unmount;
117static vfs_vptofh_t	msdosfs_vptofh;
118
119/* Maximum length of a character set name (arbitrary). */
120#define	MAXCSLEN	64
121
122static int
123update_mp(mp, td)
124	struct mount *mp;
125	struct thread *td;
126{
127	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
128	void *dos, *win, *local;
129	int error, v;
130
131	if (!vfs_getopt(mp->mnt_optnew, "kiconv", NULL, NULL)) {
132		if (msdosfs_iconv != NULL) {
133			error = vfs_getopt(mp->mnt_optnew,
134			    "cs_win", &win, NULL);
135			if (!error)
136				error = vfs_getopt(mp->mnt_optnew,
137				    "cs_local", &local, NULL);
138			if (!error)
139				error = vfs_getopt(mp->mnt_optnew,
140				    "cs_dos", &dos, NULL);
141			if (!error) {
142				msdosfs_iconv->open(win, local, &pmp->pm_u2w);
143				msdosfs_iconv->open(local, win, &pmp->pm_w2u);
144				msdosfs_iconv->open(dos, local, &pmp->pm_u2d);
145				msdosfs_iconv->open(local, dos, &pmp->pm_d2u);
146			}
147			if (error != 0)
148				return (error);
149		} else {
150			pmp->pm_w2u = NULL;
151			pmp->pm_u2w = NULL;
152			pmp->pm_d2u = NULL;
153			pmp->pm_u2d = NULL;
154		}
155	}
156
157	if (1 == vfs_scanopt(mp->mnt_optnew, "gid", "%d", &v))
158		pmp->pm_gid = v;
159	if (1 == vfs_scanopt(mp->mnt_optnew, "uid", "%d", &v))
160		pmp->pm_uid = v;
161	if (1 == vfs_scanopt(mp->mnt_optnew, "mask", "%d", &v))
162		pmp->pm_mask = v & ALLPERMS;
163	if (1 == vfs_scanopt(mp->mnt_optnew, "dirmask", "%d", &v))
164		pmp->pm_dirmask = v & ALLPERMS;
165	vfs_flagopt(mp->mnt_optnew, "shortname",
166	    &pmp->pm_flags, MSDOSFSMNT_SHORTNAME);
167	vfs_flagopt(mp->mnt_optnew, "shortnames",
168	    &pmp->pm_flags, MSDOSFSMNT_SHORTNAME);
169	vfs_flagopt(mp->mnt_optnew, "longname",
170	    &pmp->pm_flags, MSDOSFSMNT_LONGNAME);
171	vfs_flagopt(mp->mnt_optnew, "longnames",
172	    &pmp->pm_flags, MSDOSFSMNT_LONGNAME);
173	vfs_flagopt(mp->mnt_optnew, "kiconv",
174	    &pmp->pm_flags, MSDOSFSMNT_KICONV);
175
176	if (vfs_getopt(mp->mnt_optnew, "nowin95", NULL, NULL) == 0)
177		pmp->pm_flags |= MSDOSFSMNT_NOWIN95;
178	else
179		pmp->pm_flags &= ~MSDOSFSMNT_NOWIN95;
180
181	if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
182		pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
183	else if (!(pmp->pm_flags &
184	    (MSDOSFSMNT_SHORTNAME | MSDOSFSMNT_LONGNAME))) {
185		struct vnode *rootvp;
186
187		/*
188		 * Try to divine whether to support Win'95 long filenames
189		 */
190		if (FAT32(pmp))
191			pmp->pm_flags |= MSDOSFSMNT_LONGNAME;
192		else {
193			if ((error =
194			    msdosfs_root(mp, LK_EXCLUSIVE, &rootvp, td)) != 0)
195				return error;
196			pmp->pm_flags |= findwin95(VTODE(rootvp))
197				? MSDOSFSMNT_LONGNAME
198					: MSDOSFSMNT_SHORTNAME;
199			vput(rootvp);
200		}
201	}
202	return 0;
203}
204
205static int
206msdosfs_cmount(struct mntarg *ma, void *data, int flags, struct thread *td)
207{
208	struct msdosfs_args args;
209	int error;
210
211	if (data == NULL)
212		return (EINVAL);
213	error = copyin(data, &args, sizeof args);
214	if (error)
215		return (error);
216
217	ma = mount_argsu(ma, "from", args.fspec, MAXPATHLEN);
218	ma = mount_arg(ma, "export", &args.export, sizeof args.export);
219	ma = mount_argf(ma, "uid", "%d", args.uid);
220	ma = mount_argf(ma, "gid", "%d", args.gid);
221	ma = mount_argf(ma, "mask", "%d", args.mask);
222	ma = mount_argf(ma, "dirmask", "%d", args.dirmask);
223
224        ma = mount_argb(ma, args.flags & MSDOSFSMNT_SHORTNAME, "noshortname");
225        ma = mount_argb(ma, args.flags & MSDOSFSMNT_LONGNAME, "nolongname");
226        ma = mount_argb(ma, !(args.flags & MSDOSFSMNT_NOWIN95), "nowin95");
227        ma = mount_argb(ma, args.flags & MSDOSFSMNT_KICONV, "nokiconv");
228
229        ma = mount_argsu(ma, "cs_win", args.cs_win, MAXCSLEN);
230        ma = mount_argsu(ma, "cs_dos", args.cs_dos, MAXCSLEN);
231        ma = mount_argsu(ma, "cs_local", args.cs_local, MAXCSLEN);
232
233	error = kernel_mount(ma, flags);
234
235	return (error);
236}
237
238/*
239 * mp - path - addr in user space of mount point (ie /usr or whatever)
240 * data - addr in user space of mount params including the name of the block
241 * special file to treat as a filesystem.
242 */
243static int
244msdosfs_mount(struct mount *mp, struct thread *td)
245{
246	struct vnode *devvp;	  /* vnode for blk device to mount */
247	/* msdosfs specific mount control block */
248	struct msdosfsmount *pmp = NULL;
249	struct nameidata ndp;
250	int error, flags;
251	mode_t accessmode;
252	char *from;
253
254	if (vfs_filteropt(mp->mnt_optnew, msdosfs_opts))
255		return (EINVAL);
256
257	/*
258	 * If updating, check whether changing from read-only to
259	 * read/write; if there is no device name, that's all we do.
260	 */
261	if (mp->mnt_flag & MNT_UPDATE) {
262		int ro_to_rw = 0;
263		pmp = VFSTOMSDOSFS(mp);
264
265		if (vfs_flagopt(mp->mnt_optnew, "export", NULL, 0)) {
266			/*
267			 * Forbid export requests if filesystem has
268			 * MSDOSFS_LARGEFS flag set.
269			 */
270			if ((pmp->pm_flags & MSDOSFS_LARGEFS) != 0) {
271				vfs_mount_error(mp,
272				    "MSDOSFS_LARGEFS flag set, cannot export");
273				return (EOPNOTSUPP);
274			}
275		}
276		if (!(pmp->pm_flags & MSDOSFSMNT_RONLY) &&
277		    vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
278			error = VFS_SYNC(mp, MNT_WAIT, td);
279			if (error)
280				return (error);
281			flags = WRITECLOSE;
282			if (mp->mnt_flag & MNT_FORCE)
283				flags |= FORCECLOSE;
284			error = vflush(mp, 0, flags, td);
285			if (error)
286				return (error);
287			DROP_GIANT();
288			g_topology_lock();
289			g_access(pmp->pm_cp, 0, -1, 0);
290			g_topology_unlock();
291			PICKUP_GIANT();
292			/* Now the volume is clean. Mark it. */
293			error = markvoldirty(pmp, 0);
294			if (error && (flags & FORCECLOSE) == 0)
295				return (error);
296		} else if ((pmp->pm_flags & MSDOSFSMNT_RONLY) &&
297		    !vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0)) {
298			/*
299			 * If upgrade to read-write by non-root, then verify
300			 * that user has necessary permissions on the device.
301			 */
302			devvp = pmp->pm_devvp;
303			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY, td);
304			error = VOP_ACCESS(devvp, VREAD | VWRITE,
305			   td->td_ucred, td);
306			if (error)
307				error = priv_check(td, PRIV_VFS_MOUNT_PERM);
308			if (error) {
309				VOP_UNLOCK(devvp, 0, td);
310				return (error);
311			}
312			VOP_UNLOCK(devvp, 0, td);
313			DROP_GIANT();
314			g_topology_lock();
315			error = g_access(pmp->pm_cp, 0, 1, 0);
316			g_topology_unlock();
317			PICKUP_GIANT();
318			if (error)
319				return (error);
320
321			ro_to_rw = 1;
322		}
323		vfs_flagopt(mp->mnt_optnew, "ro",
324		    &pmp->pm_flags, MSDOSFSMNT_RONLY);
325		vfs_flagopt(mp->mnt_optnew, "ro",
326		    &mp->mnt_flag, MNT_RDONLY);
327
328		if (ro_to_rw) {
329			/* Now that the volume is modifiable, mark it dirty. */
330			error = markvoldirty(pmp, 1);
331			if (error)
332				return (error);
333		}
334
335		if (vfs_getopt(mp->mnt_optnew, "from", NULL, NULL)) {
336#ifdef	__notyet__	/* doesn't work correctly with current mountd	XXX */
337			if (args.flags & MSDOSFSMNT_MNTOPT) {
338				pmp->pm_flags &= ~MSDOSFSMNT_MNTOPT;
339				pmp->pm_flags |= args.flags & MSDOSFSMNT_MNTOPT;
340				if (pmp->pm_flags & MSDOSFSMNT_NOWIN95)
341					pmp->pm_flags |= MSDOSFSMNT_SHORTNAME;
342			}
343#endif
344		}
345	}
346	/*
347	 * Not an update, or updating the name: look up the name
348	 * and verify that it refers to a sensible disk device.
349	 */
350	if (vfs_getopt(mp->mnt_optnew, "from", (void **)&from, NULL))
351		return (EINVAL);
352	NDINIT(&ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, from, td);
353	error = namei(&ndp);
354	if (error)
355		return (error);
356	devvp = ndp.ni_vp;
357	NDFREE(&ndp, NDF_ONLY_PNBUF);
358
359	if (!vn_isdisk(devvp, &error)) {
360		vput(devvp);
361		return (error);
362	}
363	/*
364	 * If mount by non-root, then verify that user has necessary
365	 * permissions on the device.
366	 */
367	accessmode = VREAD;
368	if ((mp->mnt_flag & MNT_RDONLY) == 0)
369		accessmode |= VWRITE;
370	error = VOP_ACCESS(devvp, accessmode, td->td_ucred, td);
371	if (error)
372		error = priv_check(td, PRIV_VFS_MOUNT_PERM);
373	if (error) {
374		vput(devvp);
375		return (error);
376	}
377	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
378		error = mountmsdosfs(devvp, mp, td);
379#ifdef MSDOSFS_DEBUG		/* only needed for the printf below */
380		pmp = VFSTOMSDOSFS(mp);
381#endif
382	} else {
383		if (devvp != pmp->pm_devvp)
384			error = EINVAL;	/* XXX needs translation */
385		else
386			vput(devvp);
387	}
388	if (error) {
389		vrele(devvp);
390		return (error);
391	}
392
393	error = update_mp(mp, td);
394	if (error) {
395		if ((mp->mnt_flag & MNT_UPDATE) == 0)
396			msdosfs_unmount(mp, MNT_FORCE, td);
397		return error;
398	}
399
400	vfs_mountedfrom(mp, from);
401#ifdef MSDOSFS_DEBUG
402	printf("msdosfs_mount(): mp %p, pmp %p, inusemap %p\n", mp, pmp, pmp->pm_inusemap);
403#endif
404	return (0);
405}
406
407static int
408mountmsdosfs(devvp, mp, td)
409	struct vnode *devvp;
410	struct mount *mp;
411	struct thread *td;
412{
413	struct msdosfsmount *pmp;
414	struct buf *bp;
415	struct cdev *dev = devvp->v_rdev;
416	union bootsector *bsp;
417	struct byte_bpb33 *b33;
418	struct byte_bpb50 *b50;
419	struct byte_bpb710 *b710;
420	u_int8_t SecPerClust;
421	u_long clusters;
422	int	ronly, error;
423	struct g_consumer *cp;
424	struct bufobj *bo;
425
426	ronly = !vfs_getopt(mp->mnt_optnew, "ro", NULL, NULL);
427	/* XXX: use VOP_ACCESS to check FS perms */
428	DROP_GIANT();
429	g_topology_lock();
430	error = g_vfs_open(devvp, &cp, "msdos", ronly ? 0 : 1);
431	g_topology_unlock();
432	PICKUP_GIANT();
433	VOP_UNLOCK(devvp, 0, td);
434	if (error)
435		return (error);
436
437	bo = &devvp->v_bufobj;
438	bp  = NULL; /* both used in error_exit */
439	pmp = NULL;
440
441	/*
442	 * Read the boot sector of the filesystem, and then check the
443	 * boot signature.  If not a dos boot sector then error out.
444	 *
445	 * NOTE: 2048 is a maximum sector size in current...
446	 */
447	error = bread(devvp, 0, 2048, NOCRED, &bp);
448	if (error)
449		goto error_exit;
450	bp->b_flags |= B_AGE;
451	bsp = (union bootsector *)bp->b_data;
452	b33 = (struct byte_bpb33 *)bsp->bs33.bsBPB;
453	b50 = (struct byte_bpb50 *)bsp->bs50.bsBPB;
454	b710 = (struct byte_bpb710 *)bsp->bs710.bsBPB;
455
456#ifndef MSDOSFS_NOCHECKSIG
457	if (bsp->bs50.bsBootSectSig0 != BOOTSIG0
458	    || bsp->bs50.bsBootSectSig1 != BOOTSIG1) {
459		error = EINVAL;
460		goto error_exit;
461	}
462#endif
463
464	pmp = malloc(sizeof *pmp, M_MSDOSFSMNT, M_WAITOK | M_ZERO);
465	pmp->pm_mountp = mp;
466	pmp->pm_cp = cp;
467	pmp->pm_bo = bo;
468
469	/*
470	 * Experimental support for large MS-DOS filesystems.
471	 * WARNING: This uses at least 32 bytes of kernel memory (which is not
472	 * reclaimed until the FS is unmounted) for each file on disk to map
473	 * between the 32-bit inode numbers used by VFS and the 64-bit
474	 * pseudo-inode numbers used internally by msdosfs. This is only
475	 * safe to use in certain controlled situations (e.g. read-only FS
476	 * with less than 1 million files).
477	 * Since the mappings do not persist across unmounts (or reboots), these
478	 * filesystems are not suitable for exporting through NFS, or any other
479	 * application that requires fixed inode numbers.
480	 */
481	vfs_flagopt(mp->mnt_optnew, "large", &pmp->pm_flags,
482	  MSDOSFS_LARGEFS);
483
484	/*
485	 * Compute several useful quantities from the bpb in the
486	 * bootsector.  Copy in the dos 5 variant of the bpb then fix up
487	 * the fields that are different between dos 5 and dos 3.3.
488	 */
489	SecPerClust = b50->bpbSecPerClust;
490	pmp->pm_BytesPerSec = getushort(b50->bpbBytesPerSec);
491	if (pmp->pm_BytesPerSec < DEV_BSIZE) {
492		error = EINVAL;
493		goto error_exit;
494	}
495	pmp->pm_ResSectors = getushort(b50->bpbResSectors);
496	pmp->pm_FATs = b50->bpbFATs;
497	pmp->pm_RootDirEnts = getushort(b50->bpbRootDirEnts);
498	pmp->pm_Sectors = getushort(b50->bpbSectors);
499	pmp->pm_FATsecs = getushort(b50->bpbFATsecs);
500	pmp->pm_SecPerTrack = getushort(b50->bpbSecPerTrack);
501	pmp->pm_Heads = getushort(b50->bpbHeads);
502	pmp->pm_Media = b50->bpbMedia;
503
504	/* calculate the ratio of sector size to DEV_BSIZE */
505	pmp->pm_BlkPerSec = pmp->pm_BytesPerSec / DEV_BSIZE;
506
507	/* XXX - We should probably check more values here */
508	if (!pmp->pm_BytesPerSec || !SecPerClust
509		|| !pmp->pm_Heads
510#ifdef PC98
511    		|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 255) {
512#else
513		|| !pmp->pm_SecPerTrack || pmp->pm_SecPerTrack > 63) {
514#endif
515		error = EINVAL;
516		goto error_exit;
517	}
518
519	if (pmp->pm_Sectors == 0) {
520		pmp->pm_HiddenSects = getulong(b50->bpbHiddenSecs);
521		pmp->pm_HugeSectors = getulong(b50->bpbHugeSectors);
522	} else {
523		pmp->pm_HiddenSects = getushort(b33->bpbHiddenSecs);
524		pmp->pm_HugeSectors = pmp->pm_Sectors;
525	}
526	if (!(pmp->pm_flags & MSDOSFS_LARGEFS)) {
527		if (pmp->pm_HugeSectors > 0xffffffff /
528		    (pmp->pm_BytesPerSec / sizeof(struct direntry)) + 1) {
529			/*
530			 * We cannot deal currently with this size of disk
531			 * due to fileid limitations (see msdosfs_getattr and
532			 * msdosfs_readdir)
533			 */
534			error = EINVAL;
535			vfs_mount_error(mp,
536			    "Disk too big, try '-o large' mount option");
537			goto error_exit;
538		}
539	}
540
541	if (pmp->pm_RootDirEnts == 0) {
542		if (pmp->pm_Sectors
543		    || pmp->pm_FATsecs
544		    || getushort(b710->bpbFSVers)) {
545			error = EINVAL;
546			printf("mountmsdosfs(): bad FAT32 filesystem\n");
547			goto error_exit;
548		}
549		pmp->pm_fatmask = FAT32_MASK;
550		pmp->pm_fatmult = 4;
551		pmp->pm_fatdiv = 1;
552		pmp->pm_FATsecs = getulong(b710->bpbBigFATsecs);
553		if (getushort(b710->bpbExtFlags) & FATMIRROR)
554			pmp->pm_curfat = getushort(b710->bpbExtFlags) & FATNUM;
555		else
556			pmp->pm_flags |= MSDOSFS_FATMIRROR;
557	} else
558		pmp->pm_flags |= MSDOSFS_FATMIRROR;
559
560	/*
561	 * Check a few values (could do some more):
562	 * - logical sector size: power of 2, >= block size
563	 * - sectors per cluster: power of 2, >= 1
564	 * - number of sectors:   >= 1, <= size of partition
565	 * - number of FAT sectors: >= 1
566	 */
567	if ( (SecPerClust == 0)
568	  || (SecPerClust & (SecPerClust - 1))
569	  || (pmp->pm_BytesPerSec < DEV_BSIZE)
570	  || (pmp->pm_BytesPerSec & (pmp->pm_BytesPerSec - 1))
571	  || (pmp->pm_HugeSectors == 0)
572	  || (pmp->pm_FATsecs == 0)
573	) {
574		error = EINVAL;
575		goto error_exit;
576	}
577
578	pmp->pm_HugeSectors *= pmp->pm_BlkPerSec;
579	pmp->pm_HiddenSects *= pmp->pm_BlkPerSec; /* XXX not used? */
580	pmp->pm_FATsecs     *= pmp->pm_BlkPerSec;
581	SecPerClust         *= pmp->pm_BlkPerSec;
582
583	pmp->pm_fatblk = pmp->pm_ResSectors * pmp->pm_BlkPerSec;
584
585	if (FAT32(pmp)) {
586		pmp->pm_rootdirblk = getulong(b710->bpbRootClust);
587		pmp->pm_firstcluster = pmp->pm_fatblk
588			+ (pmp->pm_FATs * pmp->pm_FATsecs);
589		pmp->pm_fsinfo = getushort(b710->bpbFSInfo) * pmp->pm_BlkPerSec;
590	} else {
591		pmp->pm_rootdirblk = pmp->pm_fatblk +
592			(pmp->pm_FATs * pmp->pm_FATsecs);
593		pmp->pm_rootdirsize = (pmp->pm_RootDirEnts * sizeof(struct direntry)
594				       + DEV_BSIZE - 1)
595			/ DEV_BSIZE; /* in blocks */
596		pmp->pm_firstcluster = pmp->pm_rootdirblk + pmp->pm_rootdirsize;
597	}
598
599	pmp->pm_maxcluster = (pmp->pm_HugeSectors - pmp->pm_firstcluster) /
600	    SecPerClust + 1;
601	pmp->pm_fatsize = pmp->pm_FATsecs * DEV_BSIZE; /* XXX not used? */
602
603	if (pmp->pm_fatmask == 0) {
604		if (pmp->pm_maxcluster
605		    <= ((CLUST_RSRVD - CLUST_FIRST) & FAT12_MASK)) {
606			/*
607			 * This will usually be a floppy disk. This size makes
608			 * sure that one fat entry will not be split across
609			 * multiple blocks.
610			 */
611			pmp->pm_fatmask = FAT12_MASK;
612			pmp->pm_fatmult = 3;
613			pmp->pm_fatdiv = 2;
614		} else {
615			pmp->pm_fatmask = FAT16_MASK;
616			pmp->pm_fatmult = 2;
617			pmp->pm_fatdiv = 1;
618		}
619	}
620
621	clusters = (pmp->pm_fatsize / pmp->pm_fatmult) * pmp->pm_fatdiv;
622	if (pmp->pm_maxcluster >= clusters) {
623		printf("Warning: number of clusters (%ld) exceeds FAT "
624		    "capacity (%ld)\n", pmp->pm_maxcluster + 1, clusters);
625		pmp->pm_maxcluster = clusters - 1;
626	}
627
628
629	if (FAT12(pmp))
630		pmp->pm_fatblocksize = 3 * pmp->pm_BytesPerSec;
631	else
632		pmp->pm_fatblocksize = MSDOSFS_DFLTBSIZE;
633
634	pmp->pm_fatblocksec = pmp->pm_fatblocksize / DEV_BSIZE;
635	pmp->pm_bnshift = ffs(DEV_BSIZE) - 1;
636
637	/*
638	 * Compute mask and shift value for isolating cluster relative byte
639	 * offsets and cluster numbers from a file offset.
640	 */
641	pmp->pm_bpcluster = SecPerClust * DEV_BSIZE;
642	pmp->pm_crbomask = pmp->pm_bpcluster - 1;
643	pmp->pm_cnshift = ffs(pmp->pm_bpcluster) - 1;
644
645	/*
646	 * Check for valid cluster size
647	 * must be a power of 2
648	 */
649	if (pmp->pm_bpcluster ^ (1 << pmp->pm_cnshift)) {
650		error = EINVAL;
651		goto error_exit;
652	}
653
654	/*
655	 * Release the bootsector buffer.
656	 */
657	brelse(bp);
658	bp = NULL;
659
660	/*
661	 * Check FSInfo.
662	 */
663	if (pmp->pm_fsinfo) {
664		struct fsinfo *fp;
665
666		if ((error = bread(devvp, pmp->pm_fsinfo, fsi_size(pmp),
667		    NOCRED, &bp)) != 0)
668			goto error_exit;
669		fp = (struct fsinfo *)bp->b_data;
670		if (!bcmp(fp->fsisig1, "RRaA", 4)
671		    && !bcmp(fp->fsisig2, "rrAa", 4)
672		    && !bcmp(fp->fsisig3, "\0\0\125\252", 4)
673		    && !bcmp(fp->fsisig4, "\0\0\125\252", 4)) {
674			pmp->pm_nxtfree = getulong(fp->fsinxtfree);
675			if (pmp->pm_nxtfree == 0xffffffff)
676				pmp->pm_nxtfree = CLUST_FIRST;
677		} else
678			pmp->pm_fsinfo = 0;
679		brelse(bp);
680		bp = NULL;
681	}
682
683	/*
684	 * Check and validate (or perhaps invalidate?) the fsinfo structure?
685	 */
686	if (pmp->pm_fsinfo && pmp->pm_nxtfree > pmp->pm_maxcluster) {
687		printf(
688		"Next free cluster in FSInfo (%lu) exceeds maxcluster (%lu)\n",
689		    pmp->pm_nxtfree, pmp->pm_maxcluster);
690		error = EINVAL;
691		goto error_exit;
692	}
693
694	/*
695	 * Allocate memory for the bitmap of allocated clusters, and then
696	 * fill it in.
697	 */
698	pmp->pm_inusemap = malloc(howmany(pmp->pm_maxcluster + 1, N_INUSEBITS)
699				  * sizeof(*pmp->pm_inusemap),
700				  M_MSDOSFSFAT, M_WAITOK);
701
702	/*
703	 * fillinusemap() needs pm_devvp.
704	 */
705	pmp->pm_devvp = devvp;
706
707	/*
708	 * Have the inuse map filled in.
709	 */
710	if ((error = fillinusemap(pmp)) != 0)
711		goto error_exit;
712
713	/*
714	 * If they want fat updates to be synchronous then let them suffer
715	 * the performance degradation in exchange for the on disk copy of
716	 * the fat being correct just about all the time.  I suppose this
717	 * would be a good thing to turn on if the kernel is still flakey.
718	 */
719	if (mp->mnt_flag & MNT_SYNCHRONOUS)
720		pmp->pm_flags |= MSDOSFSMNT_WAITONFAT;
721
722	/*
723	 * Finish up.
724	 */
725	if (ronly)
726		pmp->pm_flags |= MSDOSFSMNT_RONLY;
727	else {
728		/* Mark the volume dirty while it is mounted read/write. */
729		if ((error = markvoldirty(pmp, 1)) != 0)
730			goto error_exit;
731		pmp->pm_fmod = 1;
732	}
733	mp->mnt_data = (qaddr_t) pmp;
734	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
735	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
736	MNT_ILOCK(mp);
737	mp->mnt_flag |= MNT_LOCAL;
738	MNT_IUNLOCK(mp);
739
740	if (pmp->pm_flags & MSDOSFS_LARGEFS)
741		msdosfs_fileno_init(mp);
742
743	return 0;
744
745error_exit:
746	if (bp)
747		brelse(bp);
748	if (cp != NULL) {
749		DROP_GIANT();
750		g_topology_lock();
751		g_vfs_close(cp, td);
752		g_topology_unlock();
753		PICKUP_GIANT();
754	}
755	if (pmp) {
756		if (pmp->pm_inusemap)
757			free(pmp->pm_inusemap, M_MSDOSFSFAT);
758		free(pmp, M_MSDOSFSMNT);
759		mp->mnt_data = (qaddr_t)0;
760	}
761	return (error);
762}
763
764/*
765 * Unmount the filesystem described by mp.
766 */
767static int
768msdosfs_unmount(mp, mntflags, td)
769	struct mount *mp;
770	int mntflags;
771	struct thread *td;
772{
773	struct msdosfsmount *pmp;
774	int error, flags;
775
776	flags = 0;
777	if (mntflags & MNT_FORCE)
778		flags |= FORCECLOSE;
779	error = vflush(mp, 0, flags, td);
780	if (error)
781		return error;
782	pmp = VFSTOMSDOSFS(mp);
783	if (pmp->pm_flags & MSDOSFSMNT_KICONV && msdosfs_iconv) {
784		if (pmp->pm_w2u)
785			msdosfs_iconv->close(pmp->pm_w2u);
786		if (pmp->pm_u2w)
787			msdosfs_iconv->close(pmp->pm_u2w);
788		if (pmp->pm_d2u)
789			msdosfs_iconv->close(pmp->pm_d2u);
790		if (pmp->pm_u2d)
791			msdosfs_iconv->close(pmp->pm_u2d);
792	}
793
794	/* If the volume was mounted read/write, mark it clean now. */
795	if ((pmp->pm_flags & MSDOSFSMNT_RONLY) == 0) {
796		error = markvoldirty(pmp, 0);
797		if (error && (flags & FORCECLOSE) == 0)
798			return (error);
799	}
800#ifdef MSDOSFS_DEBUG
801	{
802		struct vnode *vp = pmp->pm_devvp;
803
804		VI_LOCK(vp);
805		vn_printf(vp,
806		    "msdosfs_umount(): just before calling VOP_CLOSE()\n");
807		printf("freef %p, freeb %p, mount %p\n",
808		    TAILQ_NEXT(vp, v_freelist), vp->v_freelist.tqe_prev,
809		    vp->v_mount);
810		printf("cleanblkhd %p, dirtyblkhd %p, numoutput %ld, type %d\n",
811		    TAILQ_FIRST(&vp->v_bufobj.bo_clean.bv_hd),
812		    TAILQ_FIRST(&vp->v_bufobj.bo_dirty.bv_hd),
813		    vp->v_bufobj.bo_numoutput, vp->v_type);
814		VI_UNLOCK(vp);
815	}
816#endif
817	DROP_GIANT();
818	g_topology_lock();
819	g_vfs_close(pmp->pm_cp, td);
820	g_topology_unlock();
821	PICKUP_GIANT();
822	vrele(pmp->pm_devvp);
823	free(pmp->pm_inusemap, M_MSDOSFSFAT);
824	if (pmp->pm_flags & MSDOSFS_LARGEFS) {
825		msdosfs_fileno_free(mp);
826	}
827	free(pmp, M_MSDOSFSMNT);
828	mp->mnt_data = (qaddr_t)0;
829	MNT_ILOCK(mp);
830	mp->mnt_flag &= ~MNT_LOCAL;
831	MNT_IUNLOCK(mp);
832	return (error);
833}
834
835static int
836msdosfs_root(mp, flags, vpp, td)
837	struct mount *mp;
838	int flags;
839	struct vnode **vpp;
840	struct thread *td;
841{
842	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
843	struct denode *ndep;
844	int error;
845
846#ifdef MSDOSFS_DEBUG
847	printf("msdosfs_root(); mp %p, pmp %p\n", mp, pmp);
848#endif
849	error = deget(pmp, MSDOSFSROOT, MSDOSFSROOT_OFS, &ndep);
850	if (error)
851		return (error);
852	*vpp = DETOV(ndep);
853	return (0);
854}
855
856static int
857msdosfs_statfs(mp, sbp, td)
858	struct mount *mp;
859	struct statfs *sbp;
860	struct thread *td;
861{
862	struct msdosfsmount *pmp;
863
864	pmp = VFSTOMSDOSFS(mp);
865	sbp->f_bsize = pmp->pm_bpcluster;
866	sbp->f_iosize = pmp->pm_bpcluster;
867	sbp->f_blocks = pmp->pm_maxcluster + 1;
868	sbp->f_bfree = pmp->pm_freeclustercount;
869	sbp->f_bavail = pmp->pm_freeclustercount;
870	sbp->f_files = pmp->pm_RootDirEnts;			/* XXX */
871	sbp->f_ffree = 0;	/* what to put in here? */
872	return (0);
873}
874
875static int
876msdosfs_sync(mp, waitfor, td)
877	struct mount *mp;
878	int waitfor;
879	struct thread *td;
880{
881	struct vnode *vp, *nvp;
882	struct denode *dep;
883	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
884	int error, allerror = 0;
885
886	/*
887	 * If we ever switch to not updating all of the fats all the time,
888	 * this would be the place to update them from the first one.
889	 */
890	if (pmp->pm_fmod != 0) {
891		if (pmp->pm_flags & MSDOSFSMNT_RONLY)
892			panic("msdosfs_sync: rofs mod");
893		else {
894			/* update fats here */
895		}
896	}
897	/*
898	 * Write back each (modified) denode.
899	 */
900	MNT_ILOCK(mp);
901loop:
902	MNT_VNODE_FOREACH(vp, mp, nvp) {
903		VI_LOCK(vp);
904		if (vp->v_type == VNON || (vp->v_iflag & VI_DOOMED)) {
905			VI_UNLOCK(vp);
906			continue;
907		}
908		MNT_IUNLOCK(mp);
909		dep = VTODE(vp);
910		if ((dep->de_flag &
911		    (DE_ACCESS | DE_CREATE | DE_UPDATE | DE_MODIFIED)) == 0 &&
912		    (vp->v_bufobj.bo_dirty.bv_cnt == 0 ||
913		    waitfor == MNT_LAZY)) {
914			VI_UNLOCK(vp);
915			MNT_ILOCK(mp);
916			continue;
917		}
918		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK, td);
919		if (error) {
920			MNT_ILOCK(mp);
921			if (error == ENOENT)
922				goto loop;
923			continue;
924		}
925		error = VOP_FSYNC(vp, waitfor, td);
926		if (error)
927			allerror = error;
928		VOP_UNLOCK(vp, 0, td);
929		vrele(vp);
930		MNT_ILOCK(mp);
931	}
932	MNT_IUNLOCK(mp);
933
934	/*
935	 * Flush filesystem control info.
936	 */
937	if (waitfor != MNT_LAZY) {
938		vn_lock(pmp->pm_devvp, LK_EXCLUSIVE | LK_RETRY, td);
939		error = VOP_FSYNC(pmp->pm_devvp, waitfor, td);
940		if (error)
941			allerror = error;
942		VOP_UNLOCK(pmp->pm_devvp, 0, td);
943	}
944	return (allerror);
945}
946
947static int
948msdosfs_fhtovp(mp, fhp, vpp)
949	struct mount *mp;
950	struct fid *fhp;
951	struct vnode **vpp;
952{
953	struct msdosfsmount *pmp = VFSTOMSDOSFS(mp);
954	struct defid *defhp = (struct defid *) fhp;
955	struct denode *dep;
956	int error;
957
958	error = deget(pmp, defhp->defid_dirclust, defhp->defid_dirofs, &dep);
959	if (error) {
960		*vpp = NULLVP;
961		return (error);
962	}
963	*vpp = DETOV(dep);
964	vnode_create_vobject(*vpp, dep->de_FileSize, curthread);
965	return (0);
966}
967
968static int
969msdosfs_vptofh(vp, fhp)
970	struct vnode *vp;
971	struct fid *fhp;
972{
973	struct denode *dep;
974	struct defid *defhp;
975
976	dep = VTODE(vp);
977	defhp = (struct defid *)fhp;
978	defhp->defid_len = sizeof(struct defid);
979	defhp->defid_dirclust = dep->de_dirclust;
980	defhp->defid_dirofs = dep->de_diroffset;
981	/* defhp->defid_gen = dep->de_gen; */
982	return (0);
983}
984
985static struct vfsops msdosfs_vfsops = {
986	.vfs_fhtovp =		msdosfs_fhtovp,
987	.vfs_mount =		msdosfs_mount,
988	.vfs_cmount =		msdosfs_cmount,
989	.vfs_root =		msdosfs_root,
990	.vfs_statfs =		msdosfs_statfs,
991	.vfs_sync =		msdosfs_sync,
992	.vfs_unmount =		msdosfs_unmount,
993	.vfs_vptofh =		msdosfs_vptofh,
994};
995
996VFS_SET(msdosfs_vfsops, msdosfs, 0);
997MODULE_VERSION(msdosfs, 1);
998