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fs_set_lx (FS2)

int fs_set_lx( FSLXnum meta, FSLXnum data );

Description

Sets the default logical extent (LX) numbers for file creation. Each file has two parts: the main bulk of data, and the metadata which is a relatively small, fixed amount of data used to journal changes to the file. Both data and metadata can reside on the same extent, or they may be separated. The metadata, no matter where it is located, consumes one sector.

The file creation functions allow the metadata extent to be explicitly specified (in the high byte of the file number), however it is usually easier to call fs_set_lx() to set appropriate defaults. Calling fs_set_lx() is the only way to specify the data extent.

If fs_set_lx() is never called, both data and metadata will default to the first non-reserved extent number.

Parameters

meta

Extent number for metadata.

data

Extent number for data.

Return value

 0: Success.
!0: Error, e.g. non-existent LX number.

ERRNO values

ENODEV - no such extent number, or extent is reserved.

Library

FS2.LIB

See also

fcreate (FS2)