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freebsd-dev/sys/fs/msdosfs/msdosfsmount.h
Tim J. Robbins 3bc482ec1c By popular request, add a workaround that allows large (>128GB or so) 
FAT32 filesystems to be mounted, subject to some fairly serious limitations.

This works by extending the internal pseudo-inode-numbers generated from
the file's starting cluster number to 64-bits, then creating a table
mapping these into arbitrary 32-bit inode numbers, which can fit in
struct dirent's d_fileno and struct vattr's va_fileid fields. The mappings
do not persist across unmounts or reboots, so it's not possible to export
these filesystems through NFS. The mapping table may grow to be rather
large, and may grow large enough to exhaust kernel memory on filesystems
with millions of files.

Don't enable this option unless you understand the consequences.
2004-07-03 13:22:38 +00:00

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/* $FreeBSD$ */
/* $NetBSD: msdosfsmount.h,v 1.17 1997/11/17 15:37:07 ws Exp $ */
/*-
* Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
* Copyright (C) 1994, 1995, 1997 TooLs GmbH.
* All rights reserved.
* Original code by Paul Popelka (paulp@uts.amdahl.com) (see below).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*/
#ifndef _MSDOSFS_MSDOSFSMOUNT_H_
#define _MSDOSFS_MSDOSFSMOUNT_H_
#ifdef _KERNEL
#include <sys/tree.h>
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_MSDOSFSMNT);
#endif
struct msdosfs_fileno;
/*
* Layout of the mount control block for a msdos filesystem.
*/
struct msdosfsmount {
struct mount *pm_mountp;/* vfs mount struct for this fs */
struct cdev *pm_dev; /* block special device mounted */
uid_t pm_uid; /* uid to set as owner of the files */
gid_t pm_gid; /* gid to set as owner of the files */
mode_t pm_mask; /* mask to and with file protection bits
for files */
mode_t pm_dirmask; /* mask to and with file protection bits
for directories */
struct vnode *pm_devvp; /* vnode for block device mntd */
struct bpb50 pm_bpb; /* BIOS parameter blk for this fs */
u_long pm_BlkPerSec; /* How many DEV_BSIZE blocks fit inside a physical sector */
u_long pm_FATsecs; /* actual number of fat sectors */
u_long pm_fatblk; /* block # of first FAT */
u_long pm_rootdirblk; /* block # (cluster # for FAT32) of root directory number */
u_long pm_rootdirsize; /* size in blocks (not clusters) */
u_long pm_firstcluster; /* block number of first cluster */
u_long pm_maxcluster; /* maximum cluster number */
u_long pm_freeclustercount; /* number of free clusters */
u_long pm_cnshift; /* shift file offset right this amount to get a cluster number */
u_long pm_crbomask; /* and a file offset with this mask to get cluster rel offset */
u_long pm_bnshift; /* shift file offset right this amount to get a block number */
u_long pm_bpcluster; /* bytes per cluster */
u_long pm_fmod; /* ~0 if fs is modified, this can rollover to 0 */
u_long pm_fatblocksize; /* size of fat blocks in bytes */
u_long pm_fatblocksec; /* size of fat blocks in sectors */
u_long pm_fatsize; /* size of fat in bytes */
u_int32_t pm_fatmask; /* mask to use for fat numbers */
u_long pm_fsinfo; /* fsinfo block number */
u_long pm_nxtfree; /* next free cluster in fsinfo block */
u_int pm_fatmult; /* these 2 values are used in fat */
u_int pm_fatdiv; /* offset computation */
u_int pm_curfat; /* current fat for FAT32 (0 otherwise) */
u_int *pm_inusemap; /* ptr to bitmap of in-use clusters */
u_int pm_flags; /* see below */
void *pm_u2w; /* Local->Unicode iconv handle */
void *pm_w2u; /* Unicode->Local iconv handle */
void *pm_u2d; /* Unicode->DOS iconv handle */
void *pm_d2u; /* DOS->Local iconv handle */
u_int32_t pm_nfileno; /* next 32-bit fileno */
RB_HEAD(msdosfs_filenotree, msdosfs_fileno) pm_filenos; /* 64<->32-bit fileno mapping */
};
/*
* A 64-bit file number and the 32-bit file number to which it is mapped,
* in a red-black tree node.
*/
struct msdosfs_fileno {
RB_ENTRY(msdosfs_fileno) mf_tree;
uint32_t mf_fileno32;
uint64_t mf_fileno64;
};
/* Byte offset in FAT on filesystem pmp, cluster cn */
#define FATOFS(pmp, cn) ((cn) * (pmp)->pm_fatmult / (pmp)->pm_fatdiv)
#define VFSTOMSDOSFS(mp) ((struct msdosfsmount *)mp->mnt_data)
/* Number of bits in one pm_inusemap item: */
#define N_INUSEBITS (8 * sizeof(u_int))
/*
* Shorthand for fields in the bpb contained in the msdosfsmount structure.
*/
#define pm_BytesPerSec pm_bpb.bpbBytesPerSec
#define pm_ResSectors pm_bpb.bpbResSectors
#define pm_FATs pm_bpb.bpbFATs
#define pm_RootDirEnts pm_bpb.bpbRootDirEnts
#define pm_Sectors pm_bpb.bpbSectors
#define pm_Media pm_bpb.bpbMedia
#define pm_SecPerTrack pm_bpb.bpbSecPerTrack
#define pm_Heads pm_bpb.bpbHeads
#define pm_HiddenSects pm_bpb.bpbHiddenSecs
#define pm_HugeSectors pm_bpb.bpbHugeSectors
/*
* Convert pointer to buffer -> pointer to direntry
*/
#define bptoep(pmp, bp, dirofs) \
((struct direntry *)(((bp)->b_data) \
+ ((dirofs) & (pmp)->pm_crbomask)))
/*
* Convert block number to cluster number
*/
#define de_bn2cn(pmp, bn) \
((bn) >> ((pmp)->pm_cnshift - (pmp)->pm_bnshift))
/*
* Convert cluster number to block number
*/
#define de_cn2bn(pmp, cn) \
((cn) << ((pmp)->pm_cnshift - (pmp)->pm_bnshift))
/*
* Convert file offset to cluster number
*/
#define de_cluster(pmp, off) \
((off) >> (pmp)->pm_cnshift)
/*
* Clusters required to hold size bytes
*/
#define de_clcount(pmp, size) \
(((size) + (pmp)->pm_bpcluster - 1) >> (pmp)->pm_cnshift)
/*
* Convert file offset to block number
*/
#define de_blk(pmp, off) \
(de_cn2bn(pmp, de_cluster((pmp), (off))))
/*
* Convert cluster number to file offset
*/
#define de_cn2off(pmp, cn) \
((cn) << (pmp)->pm_cnshift)
/*
* Convert block number to file offset
*/
#define de_bn2off(pmp, bn) \
((bn) << (pmp)->pm_bnshift)
/*
* Map a cluster number into a filesystem relative block number.
*/
#define cntobn(pmp, cn) \
(de_cn2bn((pmp), (cn)-CLUST_FIRST) + (pmp)->pm_firstcluster)
/*
* Calculate block number for directory entry in root dir, offset dirofs
*/
#define roottobn(pmp, dirofs) \
(de_blk((pmp), (dirofs)) + (pmp)->pm_rootdirblk)
/*
* Calculate block number for directory entry at cluster dirclu, offset
* dirofs
*/
#define detobn(pmp, dirclu, dirofs) \
((dirclu) == MSDOSFSROOT \
? roottobn((pmp), (dirofs)) \
: cntobn((pmp), (dirclu)))
/*
* Calculate fsinfo block size
*/
#define fsi_size(pmp) \
(1024 << ((pmp)->pm_BlkPerSec >> 2))
int msdosfs_init(struct vfsconf *vfsp);
int msdosfs_uninit(struct vfsconf *vfsp);
int msdosfs_mountroot(void);
void msdosfs_fileno_init(struct mount *);
void msdosfs_fileno_free(struct mount *);
uint32_t msdosfs_fileno_map(struct mount *, uint64_t);
#endif /* _KERNEL */
/*
* Arguments to mount MSDOS filesystems.
*/
struct msdosfs_args {
char *fspec; /* blocks special holding the fs to mount */
struct export_args export; /* network export information */
uid_t uid; /* uid that owns msdosfs files */
gid_t gid; /* gid that owns msdosfs files */
mode_t mask; /* file mask to be applied for msdosfs perms */
int flags; /* see below */
int magic; /* version number */
u_int16_t u2w[128]; /* Local->Unicode table */
char *cs_win; /* Windows(Unicode) Charset */
char *cs_dos; /* DOS Charset */
char *cs_local; /* Local Charset */
mode_t dirmask; /* dir mask to be applied for msdosfs perms */
};
/*
* Msdosfs mount options:
*/
#define MSDOSFSMNT_SHORTNAME 1 /* Force old DOS short names only */
#define MSDOSFSMNT_LONGNAME 2 /* Force Win'95 long names */
#define MSDOSFSMNT_NOWIN95 4 /* Completely ignore Win95 entries */
#define MSDOSFSMNT_KICONV 0x10 /* Use libiconv to convert chars */
/* All flags above: */
#define MSDOSFSMNT_MNTOPT \
(MSDOSFSMNT_SHORTNAME|MSDOSFSMNT_LONGNAME|MSDOSFSMNT_NOWIN95 \
|MSDOSFSMNT_KICONV)
#define MSDOSFSMNT_RONLY 0x80000000 /* mounted read-only */
#define MSDOSFSMNT_WAITONFAT 0x40000000 /* mounted synchronous */
#define MSDOSFS_FATMIRROR 0x20000000 /* FAT is mirrored */
#define MSDOSFS_LARGEFS 0x10000000 /* perform fileno mapping */
#define MSDOSFS_ARGSMAGIC 0xe4eff300
#endif /* !_MSDOSFS_MSDOSFSMOUNT_H_ */
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