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QUERY_FILE_LAYOUT_OUTPUT structure (ntifs.h)

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The QUERY_FILE_LAYOUT_OUTPUT structure serves as a header for the file layout entries that are returned from a FSCTL_QUERY_FILE_LAYOUT request.

Syntax

typedef struct _QUERY_FILE_LAYOUT_OUTPUT {
  ULONG FileEntryCount;
  ULONG FirstFileOffset;
  ULONG Flags;
  ULONG Reserved;
} QUERY_FILE_LAYOUT_OUTPUT, *PQUERY_FILE_LAYOUT_OUTPUT;

Members

FileEntryCount

The number of file entries that follow this structure.

FirstFileOffset

The offset in the user buffer for the first file entry.

Flags

Indicates the format of layout entries returned. Can be 0 or the following:

Value Meaning
QUERY_FILE_LAYOUT_SINGLE_INSTANCED
 Single instances of stream and file layout entries are returned. When set, only one STREAM_LAYOUT_ENTRY structure is returned per stream and only one FILE_LAYOUT_ENTRY structure is returned per file. This flag is always set for NTFS.

Reserved

Reserved.

Remarks

The file layout entries that follow the QUERY_FILE_LAYOUT_OUTPUT structure are determined by the flags set in the Flags member of QUERY_FILE_LAYOUT_INPUT provided as input to the FSCTL_QUERY_FILE_LAYOUT request. A number of FILE_LAYOUT_ENTRY structures follow QUERY_FILE_LAYOUT_OUTPUT. Depending on the entries selected to return from a query, offsets in FILE_LAYOUT_ENTRY indicate where the additional informational entries are located in the user buffer.

The following entry structures are returned when their corresponding inclusion flag is set in the Flags member of QUERY_FILE_LAYOUT_INPUT.

Entry Inclusion flag
FILE_LAYOUT_NAME_ENTRY QUERY_FILE_LAYOUT_INCLUDE_NAMES
FILE_LAYOUT_INFO_ENTRY QUERY_FILE_LAYOUT_INCLUDE_EXTRA_INFO
STREAM_LAYOUT_ENTRY QUERY_FILE_LAYOUT_INCLUDE_STREAMS
STREAM_EXTENT_ENTRY QUERY_FILE_LAYOUT_INCLUDE_EXTENTS
 

When multiple entries of the same type exist for a single FILE_LAYOUT_ENTRY structure, each informational entry structure has an offset member that indicates the location of the next entry. The chain of entry structures continues until the value of the offset member is 0.

Requirements

Requirement Value
Minimum supported client Available starting in Windows 8.
Header ntifs.h (include Ntifs.h)

See also

FSCTL_QUERY_FILE_LAYOUT

QUERY_FILE_LAYOUT_INPUT