Martin Husemann <mar...@duskware.de> writes: > On Sun, Jul 07, 2024 at 11:32:54PM -0400, Mouse wrote: >> Is bup zfs-specific? Because, if you're not doing something >> filesystem-specific, I actually think you will have trouble even >> _defining_ what "100% right" is for this test, since everything about >> sparseness, right down to whether it's even a thing, is >> filesystem-dependent. > > Indeed. Try running the test on a tmpfs or msdofs for example and you > should see the test reliably fail.
It does fail on tmpfs. I see this as a bug; it means that files written sparsely might not fit, when I'd expect them to. I can certainly understand that the person who wrote tmpfs didn't get to this, but given the long history of sparse support in the standard filesystem, I sort it weakly into bug vs feature-I'd-expect-but-is-missing. As for msdosfs, I am not surprised; that's a foreign fs with its own format and semantics -- and one that is viewed as old and primitive.
