On Tue, Dec 15, 2020 at 5:33 PM Michael D Labriola <michael.d.labriola@xxxxxxxxx> wrote: > > On Mon, Dec 14, 2020 at 6:06 PM Michael D Labriola <michael.d.labriola@xxxxxxxxx> wrote: > > > > I'm sporatically getting "no data available" as a reason to fail to > > open files on an overlay mount. Most obvious is during ln of backup > > file during apt install. Only seems to happen on copy_up from lower How do you know that? Do you have some more tracing info? > > layer. Lower layer is squashfs (I've seen it happen with both the > > default zlib and also zstd compression), upper is EXT4. > > > > I've only bumped into this problem recently with 5.9+ kernels. I'm > > gonna go see if I can reproduce in some older kernels I still have > > installed. > > Rebooting into 5.4 made the problem go away and I can apt upgrade > w/out any problems. Rebooting an affected virtual machine into 5.8 > also fixed the problem, so it looks to be something introduced in 5.9. There are no overlayfs changes v5.8..v5.9 nor squashfs changes. Are you sure that your reproducer is reliable enough for the bisection? If it is, please try to bisect the offending commit because I have no idea where it may be. > > I suppose I should try 5.10 and see if this problem has already been > fixed. > Wouldn't hurt. Thanks, Amir.
