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[netbsd-mini2440.git] / sys / fs / msdosfs / denode.h

/*      $NetBSD: denode.h,v 1.15 2007/04/09 12:21:25 pooka 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_DENODE_H_
#define _MSDOSFS_DENODE_H_

#include <miscfs/genfs/genfs_node.h>

/*
 * This is the pc filesystem specific portion of the vnode structure.
 *
 * To describe a file uniquely the de_dirclust, de_diroffset, and
 * de_StartCluster fields are used.
 *
 * de_dirclust contains the cluster number of the directory cluster
 *      containing the entry for a file or directory.
 * de_diroffset is the index into the cluster for the entry describing
 *      a file or directory.
 * de_StartCluster is the number of the first cluster of the file or directory.
 *
 * Now to describe the quirks of the pc filesystem.
 * - Clusters 0 and 1 are reserved.
 * - The first allocatable cluster is 2.
 * - The root directory is of fixed size and all blocks that make it up
 *   are contiguous.
 * - Cluster 0 refers to the root directory when it is found in the
 *   startcluster field of a directory entry that points to another directory.
 * - Cluster 0 implies a 0 length file when found in the start cluster field
 *   of a directory entry that points to a file.
 * - You can't use the cluster number 0 to derive the address of the root
 *   directory.
 * - Multiple directory entries can point to a directory. The entry in the
 *   parent directory points to a child directory.  Any directories in the
 *   child directory contain a ".." entry that points back to the parent.
 *   The child directory itself contains a "." entry that points to itself.
 * - The root directory does not contain a "." or ".." entry.
 * - Directory entries for directories are never changed once they are created
 *   (except when removed).  The size stays 0, and the last modification time
 *   is never changed.  This is because so many directory entries can point to
 *   the physical clusters that make up a directory.  It would lead to an
 *   update nightmare.
 * - The length field in a directory entry pointing to a directory contains 0
 *   (always).  The only way to find the end of a directory is to follow the
 *   cluster chain until the "last cluster" marker is found.
 *
 * My extensions to make this house of cards work.  These apply only to the in
 * memory copy of the directory entry.
 * - A reference count for each denode will be kept since dos doesn't keep such
 *   things.
 */

/*
 * Internal pseudo-offset for (nonexistent) directory entry for the root
 * dir in the root dir
 */
#define MSDOSFSROOT_OFS 0x1fffffff

/*
 * The fat cache structure. fc_fsrcn is the filesystem relative cluster
 * number that corresponds to the file relative cluster number in this
 * structure (fc_frcn).
 */
struct fatcache {
        u_long fc_frcn;         /* file relative cluster number */
        u_long fc_fsrcn;        /* filesystem relative cluster number */
};

/*
 * The fat entry cache as it stands helps make extending files a "quick"
 * operation by avoiding having to scan the fat to discover the last
 * cluster of the file. The cache also helps sequential reads by
 * remembering the last cluster read from the file.  This also prevents us
 * from having to rescan the fat to find the next cluster to read.  This
 * cache is probably pretty worthless if a file is opened by multiple
 * processes.
 */
#define FC_SIZE         3       /* number of entries in the cache */
#define FC_LASTMAP      0       /* entry the last call to pcbmap() resolved
                                 * to */
#define FC_LASTFC       1       /* entry for the last cluster in the file */
#define FC_NEXTTOLASTFC 2       /* entry for a close to the last cluster in the file */

#define FCE_EMPTY       0xffffffff      /* doesn't represent an actual cluster # */

/*
 * Set a slot in the fat cache.
 */
#define fc_setcache(dep, slot, frcn, fsrcn) \
        (dep)->de_fc[slot].fc_frcn = frcn; \
        (dep)->de_fc[slot].fc_fsrcn = fsrcn;

#define fc_last_to_nexttolast(dep) \
        do {  \
                (dep)->de_fc[FC_NEXTTOLASTFC].fc_frcn = (dep)->de_fc[FC_LASTFC].fc_frcn; \
                (dep)->de_fc[FC_NEXTTOLASTFC].fc_fsrcn = (dep)->de_fc[FC_LASTFC].fc_fsrcn; \
        } while (0)
         

/*
 * This is the in memory variant of a dos directory entry.  It is usually
 * contained within a vnode.
 */
struct denode {
        struct genfs_node de_gnode;
        LIST_ENTRY(denode) de_hash;
        struct vnode *de_vnode; /* addr of vnode we are part of */
        struct vnode *de_devvp; /* vnode of blk dev we live on */
        u_long de_flag;         /* flag bits */
        dev_t de_dev;           /* device where direntry lives */
        u_long de_dirclust;     /* cluster of the directory file containing this entry */
        u_long de_diroffset;    /* offset of this entry in the directory cluster */
        u_long de_fndoffset;    /* offset of found dir entry */
        int de_fndcnt;          /* number of slots before de_fndoffset */
        long de_refcnt;         /* reference count */
        struct msdosfsmount *de_pmp;    /* addr of our mount struct */
        struct lockf *de_lockf; /* byte level lock list */
        u_char de_Name[12];     /* name, from DOS directory entry */
        u_char de_Attributes;   /* attributes, from directory entry */
        u_char de_CHun;         /* Hundredth of second of CTime*/
        u_short de_CTime;       /* creation time */
        u_short de_CDate;       /* creation date */
        u_short de_ADate;       /* access date */
        u_short de_MTime;       /* modification time */
        u_short de_MDate;       /* modification date */
        u_long de_StartCluster; /* starting cluster of file */
        u_long de_FileSize;     /* size of file in bytes */
        struct fatcache de_fc[FC_SIZE]; /* fat cache */
};

/*
 * Values for the de_flag field of the denode.
 */
#define DE_UPDATE       0x0001  /* Modification time update request. */
#define DE_CREATE       0x0002  /* Creation time update */
#define DE_ACCESS       0x0004  /* Access time update */
#define DE_MODIFIED     0x0008  /* Denode has been modified. */
#define DE_RENAME       0x0010  /* Denode is in the process of being renamed */

/*
 * Maximum filename length in Win95
 * Note: Must be < sizeof(dirent.d_name)
 */
#define WIN_MAXLEN      255

/* Maximum size of a file on a FAT filesystem */
#define MSDOSFS_FILESIZE_MAX    0xFFFFFFFFLL

/*
 * Transfer directory entries between internal and external form.
 * dep is a struct denode * (internal form),
 * dp is a struct direntry * (external form).
 */
#define DE_INTERNALIZE32(dep, dp)                       \
         ((dep)->de_StartCluster |= getushort((dp)->deHighClust) << 16)
#define DE_INTERNALIZE(dep, dp)                         \
        (memcpy((dep)->de_Name, (dp)->deName, 11),      \
         (dep)->de_Attributes = (dp)->deAttributes,     \
         (dep)->de_CHun = (dp)->deCHundredth,           \
         (dep)->de_CTime = getushort((dp)->deCTime),    \
         (dep)->de_CDate = getushort((dp)->deCDate),    \
         (dep)->de_ADate = getushort((dp)->deADate),    \
         (dep)->de_MTime = getushort((dp)->deMTime),    \
         (dep)->de_MDate = getushort((dp)->deMDate),    \
         (dep)->de_StartCluster = getushort((dp)->deStartCluster), \
         (dep)->de_FileSize = getulong((dp)->deFileSize), \
         (FAT32((dep)->de_pmp) ? DE_INTERNALIZE32((dep), (dp)) : 0))

#define DE_EXTERNALIZE32(dp, dep)                       \
         putushort((dp)->deHighClust, (dep)->de_StartCluster >> 16)
#define DE_EXTERNALIZE16(dp, dep)                       \
         putushort((dp)->deHighClust, 0)
#define DE_EXTERNALIZE(dp, dep)                         \
        (memcpy((dp)->deName, (dep)->de_Name, 11),      \
         (dp)->deAttributes = (dep)->de_Attributes,     \
         (dp)->deCHundredth = (dep)->de_CHun,           \
         putushort((dp)->deCTime, (dep)->de_CTime),     \
         putushort((dp)->deCDate, (dep)->de_CDate),     \
         putushort((dp)->deADate, (dep)->de_ADate),     \
         putushort((dp)->deMTime, (dep)->de_MTime),     \
         putushort((dp)->deMDate, (dep)->de_MDate),     \
         putushort((dp)->deStartCluster, (dep)->de_StartCluster), \
         putulong((dp)->deFileSize,                     \
             ((dep)->de_Attributes & ATTR_DIRECTORY) ? 0 : (dep)->de_FileSize), \
         (FAT32((dep)->de_pmp) ? DE_EXTERNALIZE32((dp), (dep)) : DE_EXTERNALIZE16((dp), (dep))))

#define de_forw         de_chain[0]
#define de_back         de_chain[1]

#ifdef _KERNEL

#define VTODE(vp)       ((struct denode *)(vp)->v_data)
#define DETOV(de)       ((de)->de_vnode)

#define DETIMES(dep, acc, mod, cre, gmtoff) \
        while ((dep)->de_flag & (DE_UPDATE | DE_CREATE | DE_ACCESS)) \
                msdosfs_detimes(dep, acc, mod, cre, gmtoff)

/*
 * This overlays the fid structure (see fstypes.h)
 */
struct defid {
        u_int16_t defid_len;    /* length of structure */
        u_int16_t defid_pad;    /* force 4-byte alignment */

        u_int32_t defid_dirclust; /* cluster this dir entry came from */
        u_int32_t defid_dirofs; /* offset of entry within the cluster */
#if 0
        u_int32_t defid_gen;    /* generation number */
#endif
};

/*
 * Prototypes for MSDOSFS vnode operations
 */
int     msdosfs_lookup          (void *);
int     msdosfs_create          (void *);
int     msdosfs_mknod           (void *);
int     msdosfs_open            (void *);
int     msdosfs_close           (void *);
int     msdosfs_access          (void *);
int     msdosfs_getattr         (void *);
int     msdosfs_setattr         (void *);
int     msdosfs_read            (void *);
int     msdosfs_write           (void *);
#define msdosfs_lease_check     genfs_lease_check
#define msdosfs_ioctl           genfs_enoioctl
#define msdosfs_poll            genfs_poll
#define msdosfs_revoke          genfs_revoke
#define msdosfs_mmap            genfs_mmap
int     msdosfs_fsync           (void *);
#define msdosfs_seek            genfs_seek
int     msdosfs_remove          (void *);
int     msdosfs_link            (void *);
int     msdosfs_rename          (void *);
int     msdosfs_mkdir           (void *);
int     msdosfs_rmdir           (void *);
int     msdosfs_symlink         (void *);
int     msdosfs_readdir         (void *);
int     msdosfs_readlink        (void *);
#define msdosfs_abortop         genfs_abortop
int     msdosfs_inactive        (void *);
int     msdosfs_reclaim         (void *);
int     msdosfs_bmap            (void *);
int     msdosfs_strategy        (void *);
int     msdosfs_print           (void *);
int     msdosfs_advlock         (void *);
int     msdosfs_pathconf        (void *);

/*
 * Internal service routine prototypes.
 */
int msdosfs_update(struct vnode *, const struct timespec *,
            const struct timespec *, int);
int createde(struct denode *, struct denode *,
                struct denode **, struct componentname *);
int deextend(struct denode *, u_long, kauth_cred_t);
int deget(struct msdosfsmount *, u_long, u_long, struct denode **);
int detrunc(struct denode *, u_long, int, kauth_cred_t);
int deupdat(struct denode *, int);
int doscheckpath(struct denode *, struct denode *);
int dosdirempty(struct denode *);
int readde(struct denode *, struct buf **, struct direntry **);
int readep(struct msdosfsmount *, u_long, u_long,
                struct buf **, struct direntry **);
void reinsert(struct denode *);
int removede(struct denode *, struct denode *);
int uniqdosname(struct denode *, struct componentname *, u_char *);
int findwin95(struct denode *);
int msdosfs_gop_alloc(struct vnode *, off_t, off_t, int, kauth_cred_t);
void msdosfs_gop_markupdate(struct vnode *, int);
void msdosfs_detimes(struct denode *, const struct timespec *,
    const struct timespec *, const struct timespec *, int);
#endif  /* _KERNEL */
#endif /* _MSDOSFS_DENODE_H_ */