DosQFSInfo

This call queries information from a file system device.

DosQFSInfo

(DriveNumber, FSInfoLevel, FSInfoBuf, FSInfoBufSize)

DriveNumber (USHORT) - input

Logical drive number (0 = default, 1 = A, and so on).

When a logical drive is specified, the media in the drive is examined (local drive only) and the request is passed to the FSD responsible for managing that media or to the FSD that is attached to the drive.

FSInfoLevel (USHORT) - input
Level of file information required.
FSInfoBuf (PBYTE) - output
Address of the storage area where the system returns the requested level of file information.

Level 1 Information

For FSInfoLevel = 1, information is returned in the following structure:

filesysid (ULONG)

File system ID.
sectornum (ULONG)
Number of sectors per allocation unit.
unitnum (ULONG)
Number of allocation units.
unitavail (ULONG)
Number of allocation units available.
bytesnum (USHORT)
Number of bytes per sector.
Level 2 Information
For FSInfoLevel = 2, the information is returned in the following format:

reserved (ULONG)

Reserved
volumelength (BYTE)
Length of the volume label, not including the null.
volumelabel (CHAR)
Volume label ASCIIZ string.
FSInfoBufSize (USHORT)
Length of the buffer.
rc (USHORT) - return
Return code descriptions are:
• NO_ERROR 15
  ERROR_INVALID_DRIVE
  111
  ERROR_BUFFER_OVERFLOW
  124
  ERROR_INVALID_LEVEL
  125
  ERROR_NO_VOLUME_LABEL
  Remarks

  Trailing blanks supplied at volume label definition time are not considered to be part of the label and are therefore not returned as valid label data. Volume label is limited to a length of 11 bytes.

  Volume Serial Number is a unique 32-bit number used by OS/2 to positively identify its disk/diskette volumes. The hard error prompts the user for an unmounted removable volume by displaying both the Volume Serial Number (as an 8 digit hexadecimal number) and the Volume Label.

  If there is no volume serial number on the disk/diskette, the volume serial number information is returned as binary zeros. If there is no volume label on the disk/diskette, the volume label information is returned as blank spaces. If there is no volume serial number and/or volume label for disk/diskette volumes formatted by DOS 3.X, this information is not displayed by the Hard Error Handler.

  ---

  [Back: DosQFSAttach]
  [Next: DosQHandType]