Re: [PATCH block/for-linus] writeback: fix syncing of I_DIRTY_TIME inodes

[Tejun Heo <tj@xxxxxxxxxx>]

On Tue, Aug 18, 2015 at 11:16:03AM +0200, Jan Kara wrote:
> On Mon 17-08-15 16:02:54, Tejun Heo wrote:
> > Hello, Jan.
> > 
> > On Fri, Aug 14, 2015 at 01:14:09PM +0200, Jan Kara wrote:
> > > So the patch looks good to me. But the fact that is fixes Eryu's problem
> > > means there is something fishy going on. Either inodes get wrongly 
> > > attached
> > 
> > Seriously, it shouldn't affect size syncing or xfs but then again my
> > understanding of xfs is severely limited.
> 
> Well, i_size == 0 in XFS usually means that writeback didn't get to
> flushing delay allocated pages - inode size on disk gets increased only
> after the pages are written out in ->end_io callback. So at least this part
> makes some sense to me.

Hmm... the only possibility I can think of is tot_write_bandwidth
being zero when it shouldn't be.  I've been staring at the code for a
while now but nothing rings a bell.  Time for another debug patch, I
guess.

Thanks.

-- 
tejun