[Ocfs2-devel] [patch 4/8] ocfs2: call ocfs2_update_inode_fsync_trans when updating any inode

[Darrick J. Wong <darrick.wong@oracle.com>]

On Sun, Mar 30, 2014 at 07:05:46PM -0700, Mark Fasheh wrote:
> On Wed, Mar 19, 2014 at 02:10:02PM -0700, Andrew Morton wrote:
> > From: "Darrick J. Wong" <darrick.wong@oracle.com>
> > Subject: ocfs2: call ocfs2_update_inode_fsync_trans when updating any inode
> > 
> > Ensure that ocfs2_update_inode_fsync_trans() is called any time we touch
> > an inode in a given transaction.  This is a follow-on to the previous
> > patch to reduce lock contention and deadlocking during an fsync operation.
> 
> This looks fine but I have a question - what happens if a future patch adds
> some disk structure change but forgets to call
> ocfs2_update_inode_fsync_trans(). Could we wind up skipping some blocks to
> sync in that case?

Yes, you'd almost certainly miss some blocks if such a programming error were
introduced.  It was tempting to try to stuff the functionality into
ocfs2_journal_dirty() rather than requiring a separate call, but that's not
really suitable since not all dirty buffers are tied to inodes.  I think the
only thing we can really do to ensure at review time that anything calling
ocfs2_start_trans() also include a call to ocfs2_update_inode_fsync_trans()
somewhere.

--D
> 	--Mark
> 
> --
> Mark Fasheh