pointer MFS_Read_directory_sector
(
MFS_DRIVE_STRUCT_PTR drive_ptr,
uint_32 cluster, /*[IN] number of the cluster containing the sector to be read */
uint_16 sector, /*[IN] index of the sector within the cluster */
_mfs_error_ptr error_ptr
)
{
uint_32 abs_sector;
if ( cluster == 0 )
{
/*
** Reading the root directory
*/
abs_sector = drive_ptr->ROOT_START_SECTOR+sector;
/*
** Overflow...
*/
if ( abs_sector >= drive_ptr->DATA_START_SECTOR )
{
*error_ptr = MFS_Flush_directory_sector_buffer(drive_ptr);
drive_ptr->DIR_SECTOR_NUMBER = 0;
return(NULL);
}
}
else
{
abs_sector = CLUSTER_TO_SECTOR(cluster) + sector;
}
if ( abs_sector > drive_ptr->BPB.MEGA_SECTORS )
{
*error_ptr = MFS_Flush_directory_sector_buffer(drive_ptr);
return(NULL);
}
if ( abs_sector != drive_ptr->DIR_SECTOR_NUMBER )
{
*error_ptr = MFS_Flush_directory_sector_buffer(drive_ptr);
if ( *error_ptr )
{
return(NULL);
}
*error_ptr = MFS_Read_device_sector(drive_ptr, abs_sector, drive_ptr->DIR_SECTOR_PTR);
if ( *error_ptr )
{
MFS_Invalidate_directory_sector(drive_ptr);
return( NULL );
}
drive_ptr->DIR_SECTOR_NUMBER = abs_sector;
}
else
{
*error_ptr = MFS_NO_ERROR;
}
return(drive_ptr->DIR_SECTOR_PTR);
}
_mfs_error MFS_Clear_cluster
(
MFS_DRIVE_STRUCT_PTR drive_ptr, /*[IN] the drive on which to operate */
uint_32 cluster /*[IN] the # of the cluster to clear*/
)
{
uint_32 sector,i;
_mfs_error error_code;
#if MFSCFG_READ_ONLY_CHECK
if (MFS_is_read_only (NULL, drive_ptr))
{
return MFS_DISK_IS_WRITE_PROTECTED;
}
#endif
error_code = MFS_Flush_directory_sector_buffer(drive_ptr);
sector = CLUSTER_TO_SECTOR(cluster);
_mem_zero(drive_ptr->DIR_SECTOR_PTR, drive_ptr->BPB.SECTOR_SIZE);
for ( i = 0; ((i<drive_ptr->BPB.SECTORS_PER_CLUSTER) && (error_code==MFS_NO_ERROR));i++ )
{
error_code = MFS_Write_device_sector(drive_ptr,sector+i,drive_ptr->DIR_SECTOR_PTR);
}
drive_ptr->DIR_SECTOR_NUMBER = sector;
return(error_code);
}
_mfs_error MFS_Flush_caches
(
MFS_DRIVE_STRUCT_PTR drive_ptr
)
{
#if MFSCFG_READ_ONLY
return MFS_NO_ERROR;
#else
_mfs_error error_code, return_code = MFS_NO_ERROR;
#if MFSCFG_READ_ONLY_CHECK
if (MFS_is_read_only (NULL, drive_ptr))
{
return return_code;
}
#endif
return_code = MFS_Flush_directory_sector_buffer(drive_ptr);
error_code = MFS_Flush_data_sector_buffer(drive_ptr);
if ( return_code == MFS_NO_ERROR ) return_code = error_code;
error_code = MFS_Flush_fat_cache(drive_ptr);
if ( return_code == MFS_NO_ERROR ) return_code = error_code;
return(return_code);
#endif
}
/*FUNCTION*-------------------------------------------------------------------
*
* Function Name : MFS_Write_back_directory_sector_buffer
* Returned Value : MFS error code
* Comments :
* Write the sector buffer back to the disk.
* Assumes the semaphore is already obtained.
*END*---------------------------------------------------------------------*/
_mfs_error MFS_Write_back_directory_sector_buffer
(
MFS_DRIVE_STRUCT_PTR drive_ptr
)
{
#if MFSCFG_READ_ONLY
return MFS_NO_ERROR;
#else
_mfs_error error_code = MFS_NO_ERROR;
#if MFSCFG_READ_ONLY_CHECK
if (MFS_is_read_only (NULL, drive_ptr))
{
return error_code;
}
#endif
MFS_LOG(printf("MFS_Write_back_directory_sector_buffer"));
drive_ptr->DIR_SECTOR_DIRTY = TRUE;
if ( drive_ptr->WRITE_CACHE_POLICY==MFS_WRITE_THROUGH_CACHE )
{
error_code = MFS_Flush_directory_sector_buffer(drive_ptr);
}
return(error_code);
#endif
}
