posix_fadvise

[Ulrich Drepper]

Another function from a recent POSIX standard which requires a kernel
implementation:

	int posix_fadvise (int fd, off_t offset, size_t len, int advise)

This function works very similar to madvise (which has the name
posix_madvise in the standard) except that it works on a file and not
a mmap()ed region.

The standard defines the advises

#define POSIX_FADV_NORMAL      0 /* No further special treatment.  */
#define POSIX_FADV_RANDOM      1 /* Expect random page references.  */
#define POSIX_FADV_SEQUENTIAL  2 /* Expect sequential page references.  */
#define POSIX_FADV_WILLNEED    3 /* Will need these pages.  */
#define POSIX_FADV_DONTNEED    4 /* Don't need these pages.  */
#define POSIX_FADV_NOREUSE     5 /* Data will be accessed once.  */

(I've reused the numbers already used for the MADV_* values and added
POSIX_FADV_NOREUSE at the end.)

With madvise already in place it should not be too hard to implement
this function.

I can provide more information to somebody who wants to give it a shot.

As far posix_fallocate, this function should implemented in the kernel
with a 64-bit offset (like pread/pwrite).

-- 
---------------.      drepper at gnu.org  ,-.   1325 Chesapeake Terrace
Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
Red Hat          `--' drepper at redhat.com   `------------------------