DFSReturnFileMappingInformation

Returns file extents, each with the number of blocks, and starting file and volume block numbers

Local Servers:nonblocking
Remote Servers:N/A
NetWare Server:4.x, 5.x, 6.x
Platform:NLM
Service:Direct File System

Syntax

  #include <nwdfs.h>  
   
  LONG DFSReturnFileMappingInformation  (  
     LONG    fileHandle,   
     LONG    startingBlockNumber,   
     LONG   *numberOfEntries,   
     LONG    tableSize,   
     struct FileMapStructure   *table);

Parameters

fileHandle
(IN) Specifies the file handle returned from a prior call to open for the file.
startingBlockNumber
(IN) Specifies the starting file block address for which map is requested (zero relative).
numberOfEntries
(OUT) Points to the number of valid file map entries returned.
tableSize
(IN) Specifies the number of file map entries for which space has been allocated by the caller in the following table (that is, max # of struct FileMapStructure to be returned).
table
(OUT) Points to a table of file map entries.

Return Values

Decimal

Constant

Description

0

DFSNormalCompletion

The operation was completed and information fields are valid.

18

DFSParameterError

The function caller supplied an invalid parameter.

136

DFSInvalidFileHandle

A DFS call was made using a file handle that is not valid. Typically an open was omitted or the user inadvertently closed the file before attempting this access.

Remarks

This function is required to provide the calling NLM application with details of exactly where a given file’s logical blocks are located, including where file holes and the end of a file’s allocated storage space is, so that the application can expand the file by calling DFSExpandFile.

See Also

DFSReturnVolumeBlockInformation, DFSReturnVolumeMappingInformation