msdosfsmount.h

/*	$NetBSD: msdosfsmount.h,v 1.17 1997/11/17 15:37:07 ws Exp $	*/

/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
 * Copyright (C) 1994, 1995, 1997 TooLs GmbH.
 * All rights reserved.
 * Original code by Paul Popelka ([email protected]) (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 ([email protected])
 *
 * 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_

#if defined(_KERNEL) || defined(_WANT_MSDOSFS_INTERNALS)

#include <sys/types.h>
#ifdef _KERNEL
#include <sys/lock.h>
#include <sys/lockmgr.h>
#else
#include <sys/_lock.h>
#include <sys/_lockmgr.h>
#endif
#include <sys/_task.h>
#include <sys/tree.h>

#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_MSDOSFSMNT);
#endif

struct msdosfs_fileno;

/*
 * Layout of the mount control block for a MSDOSFS filesystem.
 */
struct msdosfsmount {
	struct mount *pm_mountp;/* vfs mount struct for this fs */
	struct g_consumer *pm_cp;
	struct bufobj *pm_bo;
	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 character device mounted */
	struct vnode *pm_odevvp;/* real devfs vnode */
	struct cdev *pm_dev;	/* character device mounted */
	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 */
	uint32_t pm_fatmask;	/* mask to use for FAT numbers */
	u_long pm_fsinfo;	/* fsinfo block number */
	u_long pm_nxtfree;	/* next place to search for a free cluster */
	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) */
	int pm_rootdirfree;	/* number of free slots in FAT12/16 root directory */
	u_int *pm_inusemap;	/* ptr to bitmap of in-use clusters */
	uint64_t 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 */
	struct lock pm_fatlock;	/* lockmgr protecting allocations */
	struct task pm_rw2ro_task; /* context for emergency remount ro */
};

/*
 * 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)))

/*
 * Increment the number of used entries in a fixed size FAT12/16 root
 * directory
 */
#define rootde_alloced(dep)			   \
	if ((dep)->de_StartCluster == MSDOSFSROOT) \
		(dep)->de_pmp->pm_rootdirfree--;

/*
 * Decrement the number of used entries in a fixed size FAT12/16 root
 * directory
 */
#define rootde_freed(dep)			   \
	if ((dep)->de_StartCluster == MSDOSFSROOT) \
		(dep)->de_pmp->pm_rootdirfree++;

#define	MSDOSFS_LOCK_MP(pmp) \
	lockmgr(&(pmp)->pm_fatlock, LK_EXCLUSIVE, NULL)
#define	MSDOSFS_UNLOCK_MP(pmp) \
	lockmgr(&(pmp)->pm_fatlock, LK_RELEASE, NULL)
#define	MSDOSFS_ASSERT_MP_LOCKED(pmp) \
	lockmgr_assert(&(pmp)->pm_fatlock, KA_XLOCKED)

#endif /* _KERNEL || _WANT_MSDOSFS_INTERNALS */

#ifdef _KERNEL
/*
 *  Arguments to mount MSDOS filesystems.
 */
struct msdosfs_args {
	char	*fspec;		/* blocks special holding the fs to mount */
	struct	oexport_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	unused1;	/* unused, was version number */
	uint16_t unused2[128];	/* no longer used, was 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 */
};
#endif /* _KERNEL */

/*
 * 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_FSIMOD		0x01000000
#define	MSDOSFS_ERR_RO		0x00800000	/* remouning ro due to error */

#ifdef _KERNEL
void msdosfs_integrity_error(struct msdosfsmount *pmp);
#endif

#endif /* !_MSDOSFS_MSDOSFSMOUNT_H_ */