Re: adding proper O_SYNC/O_DSYNC, was Re: O_DIRECT and barriers

From: Christoph Hellwig
Date: Fri Aug 28 2009 - 17:08:49 EST


On Fri, Aug 28, 2009 at 01:51:03PM -0700, Ulrich Drepper wrote:
> No, that's not a good idea. This would mean a program compiled with
> newer headers is using O_SYNC which isn't known to old kernels and
> ignored. Such programs will then not even get the current O_DSYNC
> benefits.

Ok, let's agree on how to proceed:


once 2.6.31 is out we will do the following

- do a global s/O_SYNC/O_DSYNC/g over the whole kernel tree
- add a this to include/asm-generic/fcntl.h and in modified form
to arch headers not using it:

#ifndef O_FULLSYNC
#define O_FULLSYNC 02000000
#endif

#ifndef O_RSYNC
#define O_RSYNC 04000000
#endif

#define O_SYNC (O_FULLSYNC|O_DSYNC)

- during the normal merge window I will add a real implementation for
for O_FULLSYNC and O_RSYNC

P.S. better naming suggestions for O_FULLSYNC welcome
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