On Thu, Feb 25, 2021 at 09:39:05AM +0530, Chandan Babu R wrote:
> On 23 Feb 2021 at 13:35, Dave Chinner wrote:
> > @@ -2009,13 +2010,14 @@ xlog_sync(
> > * synchronously here; for an internal log we can simply use the block
> > * layer state machine for preflushes.
> > */
> > - if (log->l_targ != log->l_mp->m_ddev_targp || split) {
> > + if (log->l_targ != log->l_mp->m_ddev_targp ||
> > + (split && (iclog->ic_flags & XLOG_ICL_NEED_FLUSH))) {
> > xfs_flush_bdev(log->l_mp->m_ddev_targp->bt_bdev);
> > - need_flush = false;
> > + iclog->ic_flags &= ~XLOG_ICL_NEED_FLUSH;
> > }
>
> If a checkpoint transaction spans across 2 or more iclogs and the log is
> stored on an external device, then the above would remove XLOG_ICL_NEED_FLUSH
> flag from iclog->ic_flags causing xlog_write_iclog() to include only REQ_FUA
> flag in the corresponding bio.
Yup, good catch, this is a subtle change of behaviour only for
external logs and only for the commit iclog that needs to flush the
previous log writes to stable storage. I'll rework the logic here.
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
