On Sat, Jan 27, 2018 at 10:34:25AM +0200, Amir Goldstein wrote: > On Thu, Jan 25, 2018 at 7:51 AM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > > The video from my talk at LCA 2018 yesterday about the XFS subvolume and > > snapshot support I'm working on has been uploaded and can be found > > here: > > > > https://www.youtube.com/watch?v=wG8FUvSGROw > > > > I don't have the code in a reviewable form yet - there's still quite > > a bit of work before I get to that point, but this is a good > > introduction to how all the pieces will fit together.... > > > > Very cool! > > Got any paper napkin design photo to share? No. I have some arch docs I wrote after the initial Poc on loopback devices and a bunch of bash, sed, awk and xfs_io hacks.... > What are the big unknowns at this point? None - all of the concepts needed for snapshot/clone/repl are now proven and have a working implementation. Matthew Wilcox has a pretty good handle on what is needed for page cache sharing, and encryption is just a matter of implementing the generic interfaces.... > Is the data part challenging because of no buffer cache for data? Not at all. I just didn't have time to implement the remapping hooks into the IO path before I gave the talk. > I suppose all subvolumes use the host fs journal? No. A subvolume is a "fully functioning filesystem" and so - by definition - they each have their own internal journal. The journal IO remapping and COW functionality all works as seen in that demo... > Not gonna share this master plan with fsdevel? There's nothing really to talk about outside of XFS until I split the device space management API out from the XFS code. And that's far from my highest priority right now... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
