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

[Tejun Heo]

Hello,

On Mon, Aug 24, 2015 at 10:51:50AM -0400, Tejun Heo wrote:
> > Bah, I see the problem and indeed it was introduced by commit e79729123f639
> > "writeback: don't issue wb_writeback_work if clean". The problem is that
> > we bail out of sync_inodes_sb() if there is no dirty IO. Which is wrong
> > because we have to wait for any outstanding IO (i.e. call wait_sb_inodes())
> > regardless of dirty state! And that also explains why Tejun's patch fixes
> > the problem because it backs out the change to the exit condition in
> > sync_inodes_sb().
> 
> Dang, I'm an idiot sandwich.

A question tho, so this means that an inode may contain dirty or
writeback pages w/o the inode being on one of the dirty lists.
Looking at the generic filesystem and writeback code, this doesn't
seem true in general.  Is this something xfs specific?

Thanks.

-- 
tejun