FreeBSD/Linux Kernel Cross Reference
sys/msdosfs/denode.h

     /*      $OpenBSD: denode.h,v 1.36 2022/08/15 01:47:09 jsg Exp $ */
     /*      $NetBSD: denode.h,v 1.24 1997/10/17 11:23:39 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
     */
    
    /*
     * 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 {
           uint32_t fc_frcn;               /* file relative cluster number */
           uint32_t 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_OLASTFC      2       /* entry for the previous last cluster */
   
   #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;
   
   /*
    * This is the in memory variant of a dos directory entry.  It is usually
    * contained within a vnode.
    */
   struct denode {
           struct denode *de_next; /* Hash chain forward */
           struct denode **de_prev; /* Hash chain back */
           struct vnode *de_vnode; /* addr of vnode we are part of */
           struct vnode *de_devvp; /* vnode of blk dev we live on */
           uint32_t de_flag;               /* flag bits */
           dev_t de_dev;           /* device where direntry lives */
           uint32_t de_dirclust;   /* cluster of the directory file containing this entry */
           uint32_t de_diroffset;  /* offset of this entry in the directory cluster */
           uint32_t 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_state *de_lockf;   /* byte level lock list */
           struct rrwlock de_lock; /* denode lock */
           u_char de_Name[11];     /* name, from DOS directory entry */
           u_char de_Attributes;   /* attributes, from directory entry */
           u_char de_CTimeHundredth; /* creation time, 1/100th of a sec */
           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 */
           uint32_t de_StartCluster; /* starting cluster of file */
           uint32_t 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       0x0004  /* Modification time update request. */
   #define DE_CREATE       0x0008  /* Creation time update */
   #define DE_ACCESS       0x0010  /* Access time update */
   #define DE_MODIFIED     0x0020  /* Denode has been modified. */
   #define DE_RENAME       0x0040  /* 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)                 \
           (bcopy((dp)->deName, (dep)->de_Name, 8),        \
            bcopy((dp)->deExtension, (dep)->de_Name + 8, 3), \
            (dep)->de_Attributes = (dp)->deAttributes,     \
            (dep)->de_CTimeHundredth = (dp)->deCTimeHundredth, \
            (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_EXTERNALIZE(dp, dep)                         \
           (bcopy((dep)->de_Name, (dp)->deName, 8),        \
            bcopy((dep)->de_Name + 8, (dp)->deExtension, 3), \
            (dp)->deAttributes = (dep)->de_Attributes,     \
            (dp)->deLowerCase = CASE_LOWER_BASE | CASE_LOWER_EXT,  \
            (dp)->deCTimeHundredth = (dep)->de_CTimeHundredth, \
            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),\
            putushort((dp)->deHighClust, \
                FAT32((dep)->de_pmp) ? (dep)->de_StartCluster >> 16 : 0))
   
   #define de_forw         de_chain[0]
   #define de_back         de_chain[1]
   
   #define VTODE(vp)       ((struct denode *)(vp)->v_data)
   #define DETOV(de)       ((de)->de_vnode)
   
   #define DETIMES(dep, acc, mod, cre) \
           if ((dep)->de_flag & (DE_UPDATE | DE_CREATE | DE_ACCESS)) { \
                   (dep)->de_flag |= DE_MODIFIED; \
                   if ((dep)->de_flag & DE_UPDATE) { \
                           unix2dostime((mod), &(dep)->de_MDate, &(dep)->de_MTime, NULL); \
                           (dep)->de_Attributes |= ATTR_ARCHIVE; \
                   } \
                   if (!((dep)->de_pmp->pm_flags & MSDOSFSMNT_NOWIN95)) { \
                           if ((dep)->de_flag & DE_ACCESS) \
                                   unix2dostime((acc), &(dep)->de_ADate, NULL, NULL); \
                           if ((dep)->de_flag & DE_CREATE) \
                                   unix2dostime((cre), &(dep)->de_CDate, &(dep)->de_CTime, &(dep)->de_CTimeHundredth); \
                   } \
                   (dep)->de_flag &= ~(DE_UPDATE | DE_CREATE | DE_ACCESS); \
           }
   
   /*
    * This overlays the fid structure (see mount.h)
    */
   struct defid {
           u_short defid_len;      /* length of structure */
           u_short defid_pad;      /* force long alignment */
   
           uint32_t defid_dirclust;        /* cluster this dir entry came from */
           uint32_t defid_dirofs;  /* offset of entry within the cluster */
   #if 0
           uint32_t        defid_gen;      /* generation number */
   #endif
   };
   
   
   #ifdef _KERNEL
   /*
    * 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 *);
   int     msdosfs_ioctl(void *);
   int     msdosfs_fsync(void *);
   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 *);
   int     msdosfs_inactive(void *);
   int     msdosfs_reclaim(void *);
   int     msdosfs_lock(void *);
   int     msdosfs_unlock(void *);
   int     msdosfs_bmap(void *);
   int     msdosfs_strategy(void *);
   int     msdosfs_print(void *);
   int     msdosfs_islocked(void *);
   int     msdosfs_advlock(void *);
   int     msdosfs_pathconf(void *);
   
   /*
    * Internal service routine prototypes.
    */
   int createde(struct denode *, struct denode *, struct denode **, struct componentname *);
   int deextend(struct denode *, uint32_t, struct ucred *);
   int deget(struct msdosfsmount *, uint32_t, uint32_t, struct denode **);
   int detrunc(struct denode *, uint32_t, int, struct ucred *, struct proc *);
   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 *, uint32_t, uint32_t, struct buf **, struct direntry **);
   void reinsert(struct denode *);
   int removede(struct denode *, struct denode *);
   int uniqdosname(struct denode *, struct componentname *, u_char *);
   #endif  /* _KERNEL */

Cache object: 71fe4a806bfec3248d4e73e9ebe5dce2