On Thu, Nov 2, 2017 at 11:57 PM, L A Walsh <lkml@xxxxxxxxx> wrote: > Amir Goldstein wrote: >> >> >> Whiteout certainly shouldn't appear that way. >> > > (thank goodness!) > >> The reason it does is that your upper fs does not support >> "d_type" (see below). >> It's a "known" issue, but don't know where/if it is documented. >> >> I expect if you look in dmesg, you will see this warning: >> "overlayfs: upper fs needs to support d_type." >> > > ---- > Yup...found that. >> >> We also do not check for lower fs d_type support. >> That can also expose old whiteouts in certain setups. >> > > ---- *ouch*. I wonder if d_type can be set for existing file systems. > I easily have some file systems that date back more than a few years. > Don't think you need to worry about that. The corner case where d_type matters on lower fs are probably not relevant for your use case. It only matters if you are using a directory that was once an upper layer as a lower layer (i.e. stacking of layers) and that layer already has whiteouts in it. ... >> >>> >>> BTW -- is the setup in that bug report even "valid"? I.e. using >>> the same single-underlying file system for all 4 directories? >>> >>> >> >> >> Yes. Actually your setup uses 2 different file system instances >> for lower and upper, which is fine, but it is perfectly valid, quite >> common and even has some advantages to use upper/lower >> on the same underlying filesystem instance. >> > > ---- > I was referring to the RH bug report where they had created > everything on 1 FS. Doesn't matter to the issue at hand. Bug happens when upper fs has no d_type support regardless of lower fs is the same or not. > I wondered about upper+lower overlap problems > on the same fs. I'd think that could get a bit tangled > Not sure what exactly you are referring to, but if you are thinking about using lower/upper directories that overlap - don't! Overlayfs will not prevent you from shooting your own foot. Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
