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

[Christoph Hellwig <hch@infradead.org>]

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