On Tue, Aug 16, 2022 at 01:21:24PM +0200, Jan Kara wrote: > 2) I_DIRTY_TIME flag passed to ->dirty_inode() callback. This is admittedly > bit of a hack. Currently XFS relies on the fact that the only time its > ->dirty_inode() callback needs to do anything is when VFS decides it is > time to writeback timestamps and XFS detects this situation by checking for > I_DIRTY_TIME in inode->i_state. Now to fix the race, we need to first clear > I_DIRTY_TIME in inode->i_state and only then call the ->dirty_inode() > callback (otherwise timestamp update can get lost). So the solution I've > suggested was to propagate the information "timestamp update needed" to XFS > through I_DIRTY_TIME in flags passed to ->dirty_inode(). Maybe we should just add a separate update_lazy_time method to make this a little more clear?
