On Tue 14-01-20 08:37:02, Christoph Hellwig wrote: > Using i_dio_count for any kind of detection is bogus. If you want to > pass flags to the writeback code please do so explicitly through > struct writeback_control. We want to detect in the writeback path whether there's direct IO (read) currently running for the inode. Not for the writeback issued from iomap_dio_rw() but for any arbitrary writeback that iomap_dio_rw() can be racing with - so struct writeback_control won't help. Now if you want to see the ugly details why this hack is needed, see my other email to Ritesh in this thread with details of the race. Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR
