dosvdirlib.c

vxworks操作系统的文件系统部分原代码

    		 pDirDesc->deDesc.nameLen + pDirDesc->deDesc.extLen,0 );
    return retVal;
    
error:
    bzero( (char *)pDstBuf, DOS_DIRENT_STD_LEN );
    return NO_SHORT;
    } /* dosVDirNameEncodeShort() */
    
/***************************************************************************
*
* dosVDirNameEncode - encode name to disk format.
*
* This routine encodes incoming file name into Windows-95 long names
* format. During encoding the
* name is verified to be composed of valid characters.
* 
* The source name is
* split into several directory entries, that has valid format,
* unless alias checksum.
* Also src name is attempted to be encoded in short manner.
*
* RETURNS: directory entries per long name include alias or (-1) if name is
*  illegal.
* 
* ERRNO:
* S_dosFsLib_ILLEGAL_NAME
*/
LOCAL int dosVDirNameEncode
    ( 
    DOS_DIR_PDESCR_ID	pDirDesc,
    PATH_ARRAY_ID	pNamePtr,	/* name buffer */
    u_char *	pDstName,	/* buffer for name in disk format */
    SHORT_ENCODE *	pShortEncodeStrat /* short name encodding */
    					 /* strategy/result */	
    )
    {
    u_char *	pSrc = pNamePtr->pName;	/* source name dynamic ptr */
    u_char *	pDst;		/* ptr to encoded destination entry */
    u_char	numEnt;		/* entries per long name */
    u_char	entNum, chNum;	/* loop counters */
    
    if( pNamePtr->nameLen > DOS_VFAT_NAME_LEN )
    	goto error;
    
    /* number of entries per long name */
    
    numEnt = ( pNamePtr->nameLen + CHAR_PER_VENTRY  - 1 ) /
    	     CHAR_PER_VENTRY;
    
    /* try to encode src name as short */
    
    bzero( (char *)pDstName, DOS_DIRENT_STD_LEN );

    if( ( dosVDirNameEncodeShort( pDirDesc, pNamePtr,
    			          pDstName ) == STRICT_SHORT ) )
    	
    	{
    	if( *pShortEncodeStrat == STRICT_SHORT )
	    {
	    return 1; 
    	    }
        *pShortEncodeStrat = STRICT_SHORT;
	}
    else
    	{
    	*pShortEncodeStrat = NOT_STRICT_SHORT;
    	}
    	
    
    bcopy( (char *)pDstName, (char *)pDstName + numEnt * DOS_DIRENT_STD_LEN,
           DOS_DIRENT_STD_LEN );

    bzero( (char *)pDstName, numEnt * DOS_DIRENT_STD_LEN );
    			    
    /* start encoding from bottom (first) entry */
    
    pDst = pDstName + (numEnt - 1) * DOS_DIRENT_STD_LEN;
    for( entNum = 1;
    	 entNum <= numEnt;
    	 entNum ++, pDst -=  DOS_DIRENT_STD_LEN )
    	{
    	*pDst = entNum;	/* encode entry number */
    	*(pDst + pDirDesc->deDesc.atrribOff) = DOS_ATTR_VFAT;
    				/* VFAT long name representation */
    	
    	/* encode characters */
    	
    	for( chNum = 0;
    	     chNum < CHAR_PER_VENTRY &&
    	     pSrc < pNamePtr->pName + pNamePtr->nameLen;
    	     pSrc ++, chNum ++ )
    	    {
    	    if( dosVDirCharEncode( pSrc, pDst + chOffsets[ chNum ],
    	    			   longNamesChar ) == ERROR )
    	    	{
    	    	goto error;
    	    	}
    	    }
    	
        /* fill extra characters in last entry with 0xff */
    	
    	for( chNum ++; chNum < CHAR_PER_VENTRY; chNum ++ )
    	    {
    	    assert( pSrc >= pNamePtr->pName + pNamePtr->nameLen );
    	    
    	    *(pDst + chOffsets[ chNum ]) = 0xff;
    	    *(pDst + chOffsets[ chNum ] + 1) = 0xff;
    	    }
    	}
    
    /* mark last entry */
    
    pDst += DOS_DIRENT_STD_LEN;
    *pDst |= DOS_VLAST_ENTRY;
        
    return numEnt + 1;

error:
    errnoSet( S_dosFsLib_ILLEGAL_NAME );
    return (-1);
    } /* dosVDirNameEncode() */
    
/***************************************************************************
*
* dosVDirClustNext - get next or add and init cluster to directory.
*
* RETURNS: OK or ERROR if end of directory is reached or
* no more cluster could be allocated or disk is full.
*/
LOCAL STATUS dosVDirClustNext
    (
    DOS_FILE_DESC_ID	pFd,
    u_int	alloc	/* 0 or DH_ALLOC */
    )
    {
    block_t	sec;	/* work count */
    
    /* get next/allocate cluster */
    
    alloc = ( alloc == 0 ) ? FAT_NOT_ALLOC : FAT_ALLOC_ONE;

    if( pFd->pVolDesc->pFatDesc->getNext( pFd, alloc ) == ERROR )
    	return ERROR;
    
    assert( pFd->pFileHdl->startClust != 0 );
    
    if( alloc == FAT_NOT_ALLOC )
    	return OK;
    
    /* init cluster */

    for( sec = pFd->curSec; sec < pFd->curSec + pFd->nSec; sec ++ )
    	{
    	if( cbioIoctl(pFd->pVolDesc->pCbio,
			CBIO_CACHE_NEWBLK, (void *)sec ) == ERROR )
    	    {
    	    return ERROR;
    	    }
    	}
        
    return (OK);
    } /* dosVDirClustNext() */

/***************************************************************************
*
* dosVDirDirentGet - get bundle directory entry from disk.
*
* This routine reads bundle directory entry from disk. 
* On this level each entry containing part of long name is accepted
* independent of others.
*
* <which> argument defines which entry to get.
* This routine can be
* used for readdir (<which> = RD_FIRST/RD_CURRENT/RD_NEXT),
* in that case <pFd> describes the
* directory is being read, or for getting directory entry
* corresponding to <pFd> (<which> = FD_ENTRY).
*
* RETURNS: OK or ERROR if directory chain end reached or
*  disk access error.
*/
LOCAL STATUS dosVDirDirentGet
    (
    DOS_FILE_DESC_ID	pFd,	/* dos file descriptor to fill */
    u_char *	pDirEnt,
    RDE_OPTION	 which		/* which entry to get */
    )
    {
    DOS_DIR_PDESCR_ID	pDirDesc = (void *)pFd->pVolDesc->pDirDesc;
    DOS_DIR_HDL_ID	pDirHdl = (void *)&(pFd->pFileHdl->dirHdl);
    int			dirEntSize = pDirDesc->deDesc.dirEntSize;
    DOS_FILE_DESC	workFd;
    
    /* prepare to operation */
    
    if( which == FD_ENTRY ) /* get directory entry of file */
    	{
    	DBG_MSG( 600, "pFd = %p, FD_ENTRY\n", pFd ,0,0,0,0,0,0,0);
    	/*
    	 * it is being read directory entry of the file/dir,
    	 * pointed by file descriptor.
    	 * Prepare working fd.
    	 */
    	workFd = *pFd;
    	workFd.curSec = pDirHdl->sector;
    	workFd.pos = pDirHdl->offset;
    	workFd.cbioCookie = pDirHdl->cookie;
    	
    	goto getEntry;
    	}
    
    /* readdir */
    
    if(  which == RD_CURRENT )	/* read current dir entry */
    	{
    	assert( pFd->nSec != 0 );
    	assert( pFd->curSec != 0 );
    	
    	goto getEntry;
    	}
    
    if( which == RD_FIRST )	/* read start dir entry */
    	{
    	DBG_MSG( 600, "pFd = %p, RD_FIRST\n", pFd ,0,0,0,0,0,0,0);
    	dosVDirRewindDir( pFd );	/* rewind directory */
    	}
    else if( which == RD_NEXT )	/* read next dir entry */
    	{
    	DBG_MSG( 600, "pFd = %p, RD_NEXT\n", pFd ,0,0,0,0,0,0,0);
    	assert( pFd->curSec != 0 );
    	
    	/* correct position */
    	
    	pFd->pos += dirEntSize;
    	
    	/* check for sector bounds */
    	
    	if( OFFSET_IN_SEC( pFd->pVolDesc, pFd->pos ) == 0 )
    	    {
    	    pFd->curSec++;
    	    pFd->nSec--;
    	    }
    	}
    else	/* impossible flag */
    	{
    	assert( which != which );
    	} 
    	
    /* may be contiguous block finished - get next contiguous block */
    	    
    if( pFd->nSec == 0 )
    	{
    	if( pFd->pVolDesc->pFatDesc->getNext(
    	    			pFd, FAT_NOT_ALLOC ) == ERROR )
    	    {
    	    return ERROR;
    	    }
    	pFd->cbioCookie = (cookie_t) NULL;	/* we jumped to other sector */
    	}
    
    workFd = *pFd;
    
getEntry:

    /* read directory entry */
    
    if( cbioBytesRW(workFd.pVolDesc->pCbio, workFd.curSec,
    		    OFFSET_IN_SEC( workFd.pVolDesc, workFd.pos ),
		    (addr_t)pDirEnt, dirEntSize, CBIO_READ,
    		    &workFd.cbioCookie ) == ERROR )
    	{
    	return ERROR;
    	}
    DBG_PRN_STR( 600, "entry: %s\n", pDirEnt,
    		 pDirDesc->deDesc.nameLen + pDirDesc->deDesc.extLen,0 );
    		 
    return OK;
    } /* dosVDirDirentGet() */

/***************************************************************************
*
* dosVDirDeStore - store some contiguous fields of directory entry.
*
* This routine stores <nBytes> pointed by <pData> starting
* from offset <offset> in directory entry is currently
* pointed by <pFd> or next to this one, depending on
* the <which> argument.
* 
* <which> can be one of PUT_CURRENT or PUT_NEXT bitwise or-ed with
* DH_ALLOC, if new directory entry is being created.
*
* RETURNS: OK or ERROR if write error occurred.
*/
LOCAL STATUS dosVDirDeStore
    (
    DOS_FILE_DESC_ID	pFd,	/* directory descriptor */
    off_t	offset,	/* offset in directory entry */
    size_t	nBytes,	/* num of bytes to write */
    void *	pData,	/* ptr to data buffer */
    u_int	which	/* (PUT_CURRENT or PUT_NEXT) ored with */
    			/* DH_ALLOC */
    )
    {
    DOS_VOLUME_DESC_ID	pVolDesc = pFd->pVolDesc;
    
    if( (which & PUT_NEXT) != 0 )
    	{
    	pFd->pos += DOS_DIRENT_STD_LEN;

    	if( OFFSET_IN_SEC( pFd->pVolDesc, pFd->pos ) == 0 )
    	    {
    	    pFd->curSec ++;
    	    pFd->nSec --;
    	    }
    	}
    
    if( pFd->nSec == 0 )	/* current cluster group exhausted */
    	{
    	if( dosVDirClustNext( pFd, (which & DH_ALLOC) ) == ERROR )
    	    return ERROR;
    	}
    
    /* store data */
    
    if( cbioBytesRW( pVolDesc->pCbio, pFd->curSec,
                     OFFSET_IN_SEC( pVolDesc, pFd->pos ) + offset,
    		pData, nBytes, CBIO_WRITE, &pFd->cbioCookie ) == ERROR )
    	{
    	return ERROR;
    	}
    
    return OK;
    } /* dosVDirDeStore() */

/***************************************************************************
*
* dosVDirEntryDel - mark long name as deleted.
* 
* This routine marks <nEnt> traditional directory entries as deleted.
* Entries are started from position is pointed by <pLnPtr>.
*
* RETURNS: OK or ERROR if disk access failed.
*/
LOCAL STATUS dosVDirEntryDel
    (
    DOS_VOLUME_DESC_ID	pVolDesc,/* dos volume descriptor */
    DIRENT_PTR_ID	pLnPtr,	/* long name start ptr */
    u_int		nEnt,	/* number of entries to mark as deleted */
    				/* 0 - to accept the number from disk */
    BOOL		always	/* delete independent of is check disk */
    				/* in progress or not */
    )
    {
    DOS_DIR_PDESCR_ID	pDirDesc;
    DOS_FILE_DESC	workFd = {0};	/* temporary file descriptor */
    DOS_FILE_HDL	workFileHdl; /* temporary file handle */
    u_char	dirent[ DOS_DIRENT_STD_LEN ]; /* directory entry buffer */
    cookie_t	cookie = (cookie_t) NULL;		/* temp buffer */
    u_int	which;
    
    if( ! always && pVolDesc->chkLevel <= DOS_CHK_ONLY )
    	return OK;

#if TRUE /* SPR#70968 fix enabled */
    /* 
     * 01o,09nov01,jkf  SPR#70968, chkdsk destroys boot sector
      *
     * When chkdsk() is in repair mode(DOS_CHK_REPAIR): it can
     * destroy the boot sector's first byte (sector 0, offset 0) 
     * by writing DOS_DEL_MARK(0xe5). The cause of the problem is
     * function dosVDirEntryDel() lacks a sanity check for
     * pLnPtr->sector being zero.
     *
     * Workaround:
     * 
     * Add an "if" statement to check if pLnPtr is illegal: 
     * 
     * if( ! always && pVolDesc->chkLevel <= DOS_CHK_ONLY )
     *     return OK;    
     *
     * /@ SPR#70968: check if pLnPtr is illegal @/
     *
     * if ( 0 == pLnPtr->sector ) 
     *     return ERROR; 
     */

    if ( 0 == pLnPtr->sector ) 
        {
        /* return ERROR if long name start pointer is from 0 sector */
        return (ERROR);
        }
#endif /* SPR#70968 fix enabled */

    pDirDesc = (void *)pVolDesc->pDirDesc;

    bzero( (char *)&workFileHdl, sizeof( workFileHdl ) );

    workFd.pVolDesc = pVolDesc;

    workFd.pFileHdl = &workFileHdl;

    workFd.curSec = pLnPtr->sector;

    workFd.pos = pLnPtr->offset;

    workFileHdl.startClust = NONE;	/* don't care */
    
    if( workFd.curSec < pVolDesc->dataStartSec )
    	{	/* old root */
    	workFd.nSec = pVolDesc->dataStartSec - workFd.curSec;
    	}
    else if( pVolDesc->pFatDesc->seek(
    				&workFd, workFd.curSec, 0 ) == ERROR )
        {
        assert( FALSE );
        return ERROR;
        }
    
    /* get number of entries per long name */
    
    if( nEnt == 0 )
    	{
        if( cbioBytesRW(pVolDesc->pCbio, workFd.curSec,
		OFFSET_IN_SEC( pVolDesc, workFd.pos ),
    		(addr_t)dirent, DOS_DIRENT_STD_LEN, 
		CBIO_READ, &cookie ) == ERROR )
    	    {
    	    return ERROR;
    	    }
    	
    	assert( dirent[ pDirDesc->deDesc.atrribOff ] == DOS_ATTR_VFAT );
    	
    	nEnt = ( *dirent & VFAT_ENTNUM_MASK ) + 1 /* include alias */;
    	}
    
    /* mark all directory entries */