On Tue 26-03-19 04:15:10, Al Viro wrote: > On Mon, Mar 25, 2019 at 08:18:25PM -0700, Mark Fasheh wrote: > > > Hey Al, > > > > It's been a while since I've looked at that bit of code but it looks like > > Ocfs2 is syncing the inode to disk and disposing of it's memory > > representation (which would include the cluster locks held) so that other > > nodes get a chance to delete the potentially orphaned inode. In Ocfs2 we > > won't delete an inode if it exists in another nodes cache. > > Wait a sec - what's the reason for forcing that write_inode_now(); why > doesn't the normal mechanism work? I'm afraid I still don't get it - > we do wait for writeback in evict_inode(), or the local filesystems > wouldn't work. I'm just guessing here but they don't want an inode cached once its last dentry goes away (it makes cluster wide synchronization easier for them and they do play tricks with cluster lock on dentries). There is some info in 513e2dae9422 "ocfs2: flush inode data to disk and free inode when i_count becomes zero" which adds this ocfs2_drop_inode() implementation. So when the last inode reference is dropped, they want to flush any dirty data to disk and evict the inode. But AFAICT they should be fine with flushing the inode from their ->evict_inode method. I_FREEING just stops the flusher thread from touching the inode but explicit writeback through write_inode_now(inode, 1) should go through just fine. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
