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2.4.3 FileAlignmentInformation

This information class is used to query the buffer alignment required by the underlying device.

A FILE_ALIGNMENT_INFORMATION data element, defined as follows, is returned by the server.


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AlignmentRequirement

AlignmentRequirement (4 bytes):  A 32-bit unsigned integer that MUST contain one of the following values.

Value

Meaning

FILE_BYTE_ALIGNMENT

0x00000000

Specifies that there are no alignment requirements for the device.

FILE_WORD_ALIGNMENT

0x00000001

Specifies that data MUST be aligned on a 2-byte boundary.

FILE_LONG_ALIGNMENT

0x00000003

Specifies that data MUST be aligned on a 4-byte boundary.

FILE_QUAD_ALIGNMENT

0x00000007

Specifies that data MUST be aligned on an 8-byte boundary.

FILE_OCTA_ALIGNMENT

0X0000000F

Specifies that data MUST be aligned on a 16-byte boundary.

FILE_32_BYTE_ALIGNMENT

0X0000001F

Specifies that data MUST be aligned on a 32-byte boundary.

FILE_64_BYTE_ALIGNMENT

0X0000003F

Specifies that data MUST be aligned on a 64-byte boundary.

FILE_128_BYTE_ALIGNMENT

0X0000007F

Specifies that data MUST be aligned on a 128-byte boundary.

FILE_256_BYTE_ALIGNMENT

0X000000FF

Specifies that data MUST be aligned on a 256-byte boundary.

FILE_512_BYTE_ALIGNMENT

0X000001FF

Specifies that data MUST be aligned on a 512-byte boundary.

This operation returns a status code as specified in section 2.2. Upon success, the status code returned by the function that processes this file information class is STATUS_SUCCESS. The most common error codes are listed in the following table.

Error code

Meaning

STATUS_INFO_LENGTH_MISMATCH

0xC0000004

The specified information record length does not match the length that is required for the specified information class.