Mauricio, Thanks for your work in finding the corner cases for data=journal. If you don't mind me asking, however --- what are the use cases for you where data=journal is the preferred mode for ext4? There are a lot of advanced features for data=journal mode which don't work. This includes things like dioread_nolock (now the default), delayed allocation, and other optimizations. It used to be that data=journal pretty nicely fell out of how ext4 worked in "normally". These days, data=journal is becoming more and more an exception case that requires special handling. And to be honest, every so often there has been discussion about whether the maintenance overhead of data=journal has been worth keeping it. So far, we just don't bother making data=journal work with things like delayed allocation, and one of ther reasons why we've kept it around is because it's a unique mode that none of the Linux file systems have. It would be useful, though, to understand what are the use cases where you (or your customers) are finding data=journal useful, so we can better optimize for their use case. And if there are enough people who care about it --- and clearly, you've invested so much effort that you definitely fall into that category :-) --- then maybe there's a business case for investing more into data=journal and trying to make it something which is easier to maintain and can work with things like delayed allocation. Thanks, - Ted
