[Cluster-devel] Re: [GFS2] Don't flush everything on fdatasync [70/70]

[Andrew Morton]

On Fri, 01 Dec 2006 10:58:58 +0000
Steven Whitehouse <swhiteho at redhat.com> wrote:

> On Thu, 2006-11-30 at 23:01 -0800, Andrew Morton wrote:
> > On Thu, 30 Nov 2006 12:24:08 +0000
> > Steven Whitehouse <swhiteho at redhat.com> wrote:
> > 
> > >  static int gfs2_fsync(struct file *file, struct dentry *dentry, int datasync)
> > >  {
> > > -	struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
> > > +	struct inode *inode = dentry->d_inode;
> > > +	int sync_state = inode->i_state & (I_DIRTY_SYNC|I_DIRTY_DATASYNC);
> > > +	int ret = 0;
> > > +	struct writeback_control wbc = {
> > > +		.sync_mode = WB_SYNC_ALL,
> > > +		.nr_to_write = 0,
> > > +	};
> > > +
> > > +	if (gfs2_is_jdata(GFS2_I(inode))) {
> > > +		gfs2_log_flush(GFS2_SB(inode), GFS2_I(inode)->i_gl);
> > > +		return 0;
> > > +	}
> > >  
> > > -	gfs2_log_flush(ip->i_gl->gl_sbd, ip->i_gl);
> > > +	if (sync_state != 0) {
> > > +		if (!datasync)
> > > +			ret = sync_inode(inode, &wbc);
> > 
> > filemap_fdatawrite() would be simpler.
> 
> I was taking my cue here from ext3 which does something similar. The
> filemap_fdatawrite() is done by the VFS before this is called with a
> filemap_fdatawait() afterwards. This was intended to flush the metadata
> via (eventually) ->write_inode() although I guess I should be calling
> write_inode_now() instead?

oh I see, you're jsut trying to write the inode itself, not the pages.

write_inode_now() will write the pages, which you seem to not want to do.
Whatever.  The APIs here are a bit awkward.