How does XFS handle file data with regards to journaling?

[Martin Steigerwald <Martin@xxxxxxxxxxxx>]

Hello,

AFAIK XFS does not support real data journaling. But when does it write 
changes to file data? Does ist write it before or after it updates the 
journal? IOW does it support ordered writes as ext3 does?

data=ordered    (*)     All data are forced directly out to the main file
system prior to its metadata being committed to the journal.

Or does it work in writeback mode?

data=writeback      Data ordering is not preserved, data may be written
into the main file system after its metadata has been                      
committed to the journal.

Regards,
-- 
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
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