dosfslib.c

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.iP "FIOLABELSET"
Sets the volume label to the string specified as <newLabel>.  The string may
consist of up to eleven ASCII characters:
.CS
    status = ioctl (fd, FIOLABELSET, "newLabel");
.CE
.iP "FIOATTRIBSET"
Sets the file attribute byte in the DOS directory entry to the new value
<newAttrib>.  The file descriptor refers to the file whose entry is to be 
modified:
.CS
    status = ioctl (fd, FIOATTRIBSET, newAttrib);
.CE
.iP "FIOCONTIG"
Allocates contiguous disk space for a file or directory.  The number of
bytes of requested space is specified in <bytesRequested>.  In general,
contiguous space should be allocated immediately after the file is
created:
.CS
    status = ioctl (fd, FIOCONTIG, bytesRequested);
.CE
.iP "FIONCONTIG"
Copies to <maxContigBytes> the size of the largest contiguous free space, 
in bytes, on the volume:
.CS
   status = ioctl (fd, FIONCONTIG, &maxContigBytes);
.CE
.iP "FIOREADDIR"
Reads the next directory entry.  The argument <dirStruct> is a DIR
directory descriptor.  Normally, the readdir() routine is used to read a
directory, rather than using the FIOREADDIR function directly.  See dirLib.
.CS
    DIR dirStruct;
    fd = open ("directory", O_RDONLY);
    status = ioctl (fd, FIOREADDIR, &dirStruct);
.CE
.iP "FIOFSTATGET"
Gets file status information (directory entry data).  The argument
<statStruct> is a pointer to a stat structure that is filled with data
describing the specified file.  Normally, the stat() or fstat() routine is
used to obtain file information, rather than using the FIOFSTATGET
function directly.  See dirLib.
.CS
    struct stat statStruct;
    fd = open ("file", O_RDONLY);
    status = ioctl (fd, FIOFSTATGET, &statStruct);
.CE
.LP
Any other ioctl() function codes are passed to the block device driver for
handling.

MEMORY CONSUMPTION

In order to minimize memory fragmentation in the system memory pool, all
memory consumed by dosFsLib will be contained within a dedicated memory
partition. This partition is accessible via the <dosFsMemPartId> global
variable.

To display the current amount of memory used by dosFsLib, call
show(dosFsMemPartId).  Please see the manual page for memPartShow() for
more details.

The following varibles may be set 
.I before dosFsLib
is initialized to change the behavior of the memory management.

If the dosFsLib memory partition is not provided, one will be allocated from
the system memory pool.  It's size defaults to 8 K, which may be changed
via the <dosFsMemPartInitSize> global. To provide a memory pool, set 
<dosFsMemPartId> to a valid PART_ID returned from memPartCreate().

The global variable <dosFsMemPartIdOptions> may be modified to change the
behavior of error handling for errors in malloc() and free(). The
options default to MEM_BLOCK_ERROR_LOG_FLAG, which will log information
about errors detected by free(). These options only affect operations on
the dosFs memory partition.

The private partition will dynamically grow as much as needed, allocating
additional memory from the system memory pool, in units no smaller than 
1 Kilobyte. This minumum unit size may be adjusted via 
the <dosFsMemPartGrowSize> global variable.

The maximum size for the dosFs memory partition may be limited via the 
global variable <dosFsMemPartCap>.  Once the cap limit has been reached or 
surpassed, dosFs will not attempt to allocate more memory from the system 
memory partition. The default value is -1, which allows uninterupted use of 
the system memory partition.

Additional debugging may be enabled via the global boolean <dosFsDebug>.
Setting this to 1 will enable verbose debug messages from the dosFs 
memory manager.

INCLUDE FILES: dosFsLib.h

SEE ALSO:
ioLib, iosLib, dirLib, ramDrv,
.I "Microsoft MS-DOS Programmer's Reference"
(Microsoft Press),
.I "Advanced MS-DOS Programming"
(Ray Duncan, Microsoft Press),
.I "VxWorks Programmer's Guide: I/O System, Local File Systems"

INTERNAL:
Note:  To represent a backslash in documentation use "\e", not "\\".
The double backslash sometimes works, but results may be unpredictable.

NFS needs a way to uniquely identify files using 32 bytes or less of
information.  For DOS, we use the inode number field (st_ino) of the stat
structure to return two items of information: the "generation number," a
counter that is incremented every time a file is created and maintained on a
per-filesystem basis, and the starting cluster number of the file.  When
files are added to the directory entry tree, they are also added to a hash
table keyed off of the starting cluster number.  Mapping between the
generation/cluster number is a simple search of the hash table to locate a
matching entry.  The generation number is stored in the first two bytes of
the FAT for each file system.
*/

/* LINTLIBRARY */

#include "vxWorks.h"
#include "ctype.h"
#include "dirent.h"
#include "ioLib.h"
#include "lstLib.h"
#include "dosFsLib.h"
#include "stdlib.h"
#include "semLib.h"
#include "sys/stat.h"
#include "string.h"
#include "errnoLib.h"
#include "stdio.h"
#include "pathLib.h"
#include "time.h"
#include "utime.h"
#include "tickLib.h"
#include "taskLib.h"
#include "private/memPartLibP.h"
#include "logLib.h"


#define	DEFAULT_MAX_ROOT_ENTS	112	/* default max # of root dir entries */
#define	DEFAULT_SEC_PER_CLUST	2	/* default sectors per cluster */
#define	DEFAULT_MEDIA_BYTE	0xF0	/* default media byte value */
#define	DEFAULT_NFATS		2	/* default number FAT copies */
#define	DEFAULT_NHIDDEN		0	/* default number of hidden sectors */
#define	DEFAULT_NRESERVED	1	/* default # of reserved sec's (min=1)*/
#define DEFAULT_OPTIONS		0	/* default volume options */
#define DOS_DEFAULT_HASH_SIZE	9	/* default hash table size (2^x) */
                                        /* default NFS file permissions */
#define DOS_DEFAULT_MODE        (S_IRWXU | S_IRWXG | S_IRWXO)

#define	DOT_PADDED	".                                       "	
					/* "." padded to long filename length */
#define	DOTDOT_PADDED	"..                                      "	
					/* ".." padded to long filename length*/

#define	EXT_SPACES	"   "		/* file extension-length set of spaces*/

#define	MODIFIED	1		/* "boolean" flags for FAT mod table */
#define	NOT_MODIFIED	0

#define DOS_OPT_ALL	(DOS_OPT_CHANGENOWARN |    \
			 DOS_OPT_AUTOSYNC |        \
			 DOS_OPT_LONGNAMES |	   \
			 DOS_OPT_EXPORT |	   \
			 DOS_OPT_LOWERCASE)		
					/* all valid options */

#define DOS_OPT_DYNAMIC	(DOS_OPT_CHANGENOWARN |    \
			 DOS_OPT_AUTOSYNC)		
					/* dynamically changable options */

#define DOS_OPT_INIT	(DOS_OPT_DYNAMIC | DOS_OPT_EXPORT | DOS_OPT_LOWERCASE)
					/* options set during dosFsDevInit */


/* Macros to test for options -
 *  "vdptr" must be defined where these are used!!
 */

#define AUTOSYNC_ENABLED	(vdptr->dosvd_options & DOS_OPT_AUTOSYNC ? \
				 TRUE : FALSE)

#define CHANGENOWARN_ENABLED	(vdptr->dosvd_options & DOS_OPT_CHANGENOWARN ? \
				 TRUE : FALSE)

#define LONGNAMES_ENABLED	(vdptr->dosvd_options & DOS_OPT_LONGNAMES ? \
				 TRUE : FALSE)

#define EXPORT_ENABLED		(vdptr->dosvd_options & DOS_OPT_EXPORT ? \
				 TRUE : FALSE)

#define LOWERCASE_ENABLED	(vdptr->dosvd_options & DOS_OPT_LOWERCASE ? \
				 TRUE : FALSE)

/* Macros for effective filename and on-disk directory entry sizes -
 *  "vdptr" must be defined where these are used!!
 */

#define EFFECTIVE_NAME_LEN	(LONGNAMES_ENABLED ? \
				 DOS_LONG_NAME_LEN : DOS_NAME_LEN)

#define EFFECTIVE_DISK_DIR_ENT_SIZE (LONGNAMES_ENABLED ? \
				     sizeof (DOS_DISK_EDIR_ENT) : \
				     sizeof (DOS_DISK_DIR_ENT))

/* Macros to test if file name is "." or ".." 
 *  "vdptr" must be defined where these are used!!
 */

#define	IS_DOT(name)	(strncmp ((char *) name, pDotPadded, \
				  EFFECTIVE_NAME_LEN) == 0)
#define	IS_DOTDOT(name)	(strncmp ((char *) name, pDotDotPadded, \
				  EFFECTIVE_NAME_LEN) == 0)


/* Define byte-swap functions as macros - some arch's may not need them */

#if (_BYTE_ORDER == _BIG_ENDIAN)	/* swapping macros for BIG_ENDIAN */

/* Aligned transfers */
#define	SWAB(pSource16, pDest16) \
			swab ((char *) pSource16, (char *) pDest16, 2)

#define	SWABL(pSource32, pDest32) \
			{swab ((char *) pSource32 + 2, (char *) pDest32, 2); \
			 swab ((char *) pSource32, (char *) pDest32 + 2, 2);}

#define	SWABL2S(pSource32, pDest16) \
			swab ((char *) pSource32 + 2, (char *) pDest16, 2)

#define	SWABS2L(pSource16, pDest32) \
			swab ((char *) pSource16, (char *) pDest32 + 2, 2)


#if (_DYNAMIC_BUS_SIZING == FALSE)

/* unaligned transfers for big endian machines that do require alignment */

#define	USWAB(pSource16, pDest16) \
			uswab ((char *) pSource16, (char *) pDest16, 2)

#define	USWABL(pSource32, pDest32) \
			{uswab ((char *) pSource32 + 2, (char *) pDest32, 2); \
			 uswab ((char *) pSource32, (char *) pDest32 + 2, 2);}

#define	USWABL2S(pSource32, pDest16) \
			uswab ((char *) pSource32 + 2, (char *) pDest16, 2)

#define	USWABS2L(pSource16, pDest32) \
			uswab ((char *) pSource16, (char *) pDest32 + 2, 2)


#else /* _DYNAMIC_BUS_SIZING == TRUE */

/* unaligned transfers for big endian machines that don't require alignment */

#define	USWAB(pSource16, pDest16) SWAB(pSource16, pDest16)
#define	USWABL(pSource32, pDest32) SWABL(pSource32, pDest32)
#define	USWABL2S(pSource32, pDest16) SWABL2S(pSource32, pDest16)
#define	USWABS2L(pSource16, pDest32)  SWABS2L(pSource16, pDest32)

#endif /* _DYNAMIC_BUS_SIZING == TRUE */


#else	/* _BYTE_ORDER == _BIG_ENDIAN 	(little endian swapping macros) */

				/* aligned transfers */

#define SWAB(pSource16, pDest16)        (*pDest16 = *pSource16)
#define SWABL(pSource32, pDest32)       (*pDest32 = *pSource32)
#define SWABL2S(pSource32, pDest16)     (*pDest16 = * (UINT16 *) pSource32)
#define SWABS2L(pSource16, pDest32)     (*pDest32 = (UINT32) *pSource16)

				/* unaligned transfers */

#define	USWAB(pSource16, pDest16)	bcopy ((char *) (pSource16), \
					       (char *) (pDest16), 2)
#define	USWABL(pSource32, pDest32) 	bcopy ((char *) (pSource32), \
					       (char *) (pDest32), 4)

#define USWABL2S(pSource32, pDest16)	bcopy ((char *) (pSource32), \
					       (char *) (pDest16), 2)
#define USWABS2L(pSource16, pDest32)	bcopy ((char *) (pSource16), \
					       (char *) (pDest32), 2)