Re: nfsd: Replace nfsd_sync() with vfs_fsync() and vfs_fsync_range()

[Trond Myklebust <Trond.Myklebust@netapp.com>]

On Fri, 2010-01-29 at 15:50 -0500, Christoph Hellwig wrote: 
> On Fri, Jan 29, 2010 at 03:19:13PM -0500, Trond Myklebust wrote:
> > From: Trond Myklebust <Trond.Myklebust@netapp.com>
> > 
> > Currently, the nfs server holds the inode->i_mutex across both the
> > filemap_write_and_wait() call and the fsync() call itself. However we know
> > that filemap_write_and_wait() is already safe against livelocks, so we only
> > need to hold the mutex across the fsync() call.
> > 
> > Fix this by reusing vfs_fsync(), which already does the right thing.
> > Also make sure that we use vfs_fsync_range() in the COMMIT operation, to
> > improve the efficiency for clients that do specify a range.
> 
> I already sent a patch to replace nfsd_sync with it that should be
> queued up.  We can't use vfs_fsync for nfsd_sync_dir as we're already
> holding i_mutex when calling it.  The vfs_fsync_range optimizations
> seems like something that should be applied ontop, though.
> 

OK. I missed your patch as it flew by on the list, but I assume it is
this one:

http://git.linux-nfs.org/?p=bfields/linux.git;a=commitdiff;h=6a68f89ee1f2d177af4a5410fa7a45734c975fd6;hp=de3cab793c6a5c8505d66bee111edcc7098380ba


I'll separate out the vfs_sync_range() changes and cobble up a patch on
top of the above changeset...

Cheers
  Trond