Ext4 breaking the promise of data=ordered ?

Posted Mar 31, 2009 22:57 UTC (Tue) by bojan (subscriber, #14302)
In reply to: Ext4 breaking the promise of data=ordered ? by sbergman27
Parent article: From ext3 to ext4: An Interview with Theodore Ts'o (Linux Magazine)

Since you mention Stephen, here is an interesting quote (from here: http://markmail.org/message/nkh4og2ymaavek73):

> Correct. Journaled data mode has the side-effect of maintaining a strict order for data writes, both with respect to each other (ie. writes in a given order will always preserve that order after a crash), and with respect to metadata such as timestamps. That's not a data integrity issue, but it is certainly a consistency issue; Unix semantics basically don't give you any consistency guarantees whatsoever unless the application is requesting consistent checkpoints via fsync/O_SYNC etc; but journaled data mode provides extra consistency nonetheless.

I think more than one person understands the _real_ semantics here.