FS_NEWSIZE

Purpose

Changes a file's logical (EOD) size.

Calling Sequence

int far pascal FS_NEWSIZE(psffsi, psffsd, len, IOflag) struct sffsi far * psffsi; struct sffsd far * psffsd; unsigned long len; unsigned short IOflag;

Where

psffsi is a pointer to the file-system-independent portion of an open file instance.

psffsd is a pointer to the file-system-dependent portion of an open file instance.

len is the desired new length of the file.

IOflag	indicates information about the operation on the handle.
IOflag == 0x0010	indicates write-through.
IOflag == 0x0020	indicates no-cache.

Remarks

The FSD should return an error if an attempt is made to write beyond the end with a direct access device handle.

The file system driver attempts to set the size (EOD) of the file to newsize and update sfi_size, if successful. If the new size is larger than the currently allocated size, the file system driver arranges for for efficient access to the newly-allocated storage.

Of the information passed in IOflag, the write-through bit is a mandatory bit in that any data written to the block device must be put out on the medium before the device driver returns. The no-cache bit, on the other hand, is an advisory bit that says whether the data being transferred is worth caching or not.