On 2019/07/22 9:05, Dave Chinner wrote: > On Sat, Jul 20, 2019 at 07:15:26AM +0000, Damien Le Moal wrote: >> Jeff, >> >> On 2019/07/19 23:25, Jeff Moyer wrote: >>> OK, I can see how a file system eases adoption across multiple >>> languages, and may, in some cases, be easier to adopt by applications. >>> However, I'm not a fan of the file system interface for this usage. >>> Once you present a file system, there are certain expectations from >>> users, and this fs breaks most of them. >> >> Your comments got me thinking more about zonefs specifications/features and I am >> now wondering if I am not pushing this too far in terms of simplicity. So here >> is a new RFC/Question to chew on... While keeping as a target the concept of >> "file == zone" or as close to it as possible, what do you think zonefs minimal >> feature set should be ? >> >> One idea I have since a while back now is this: >> 1) If a zone is unused, do not show a file for it. This means adding a dynamic >> "zone allocation" code and supporting O_CREAT on open, unlink, etc. So have more >> normal file system calls behave as with a normal FS. >> 2) Allow file names to be decided by the user instead of using a fixed names. >> Again, have O_CREAT behave as expected > > So now you have to implement a persistent directory structure, > atomic/transactional updates, etc. You've just added at least 2 > orders of magnitude complexity to zonefs and a very substantial > amount of additional, ongoing QA to ensure it works correctly. > > I think keeping it simple by exposing all zones to userspace and > leaving it to the application to track/index what zones it is > using is the simplest way forward for everyone. OK. Anything more complicated would probably be better implemented within an existing file system. Thank you for your comments. Best regards. -- Damien Le Moal Western Digital Research
