On Tue, 30 May 2023 at 16:15, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > On Tue, May 30, 2023 at 5:08 PM Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > > > > On Sat, 27 May 2023 at 16:04, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > > > > If we would want to support data-only layers in the middle on the > > > stack, which would this syntax make sense? > > > lowerdir=lower1::data1:lower2::data2 > > > > > > If this syntax makes sense to everyone, then we can change the syntax > > > of data-only in the tail from lower1::data1:data2 to lower1::data1::data2 > > > and enforce that after the first ::, only :: are allowed. > > > > > > Miklos, any thoughts? > > > I have a feeling that this was your natural interpretation when you first > > > saw the :: syntax. > > > > Yes, I think it's more natural to have a prefix for each data-only > > layer. And this is also good for extensibility, as discussed. > > > > Good timing ;-) > > I was just about to say that I changed the syntax and pushed to: > > https://github.com/amir73il/linux/commits/ovl-lazy-lowerdata-v3 > https://github.com/amir73il/xfstests/commits/ovl-lazy-lowerdata > > The gist of the documentation of v3 is: > > Below the top most lower layer, any number of lower most layers may be defined > as "data-only" lower layers, using double colon ("::") separators. > A normal lower layer is not allowed to be below a data-only layer, so single > colon separators are not allowed to the right of double colon ("::") separators. > > For example: > > mount -t overlay overlay -olowerdir=/l1:/l2:/l3::/do1::/do2 /merged > > > Do you need me to post the v3 patches? > > The changes since ovl-lazy-lowerdata-v2 branch are: > - Reabse on 6.4-rc2 + NULL deref fixes > - Syntax change Patches look good to me. Pushed v3 to overlayfs-next. It'd be interesting to hear what obstacles you encountered when trying to implement generic lazy lookup. I can put that into the pull request so the information is not lost. Thanks, Miklos
