On Thu, Jun 18, 2020 at 11:22:58PM +0530, Kanchan Joshi wrote: > I was thinking of raw block-access to zone device rather than pristine file > abstraction. Why? > And in that context, semantics, at this point, are unchanged > (i.e. same as direct writes) while flexibility of async-interface gets > added. > Synchronous-writes on single-zone sound fine, but synchronous-appends on > single-zone do not sound that fine. Where does synchronous access come into play? > > What could be a useful addition is a way for O_APPEND/RWF_APPEND writes > > to report where they actually wrote, as that comes close to Zone Append > > while still making sense at our usual abstraction level for file I/O. > > Thanks for suggesting this. O and RWF_APPEND may not go well with block > access as end-of-file will be picked from dev inode. No, but they go really well with zonefs. > But perhaps a new > flag like RWF_ZONE_APPEND can help to transform writes (aio or uring) > into append without introducing new opcodes. I don't think this is a good idea. Zones are a concept for a a very specific class of zoned devices. Trying to shoe-horn this into the byte address files / whole device abstraction not only is ugly conceptually but also adds the overhead for it to the VFS. And O_APPEND that returns the written position OTOH makes total sense at the file level as well and not just for raw zoned devices.
