On Sat 13 Apr 2019 02:53:42 AM CEST, Max Reitz wrote: >> Calling x-blockdev-reopen without 'backing' should only fail if >> >> a) the image has a backing file attached to it. >> In this case it doesn't: we just detached it in the previous line. >> >> b) there's a default backing file written on the image header. >> In this case there isn't (hd0 is created without one in setUp()). > > That’s what I thought, too, hence me applying effectively the same > change to the test in v4 of my series as you in your "Fix check for > default backing files" series: > > http://lists.nongnu.org/archive/html/qemu-block/2019-04/msg00308.html > >> So it should not fail. I think the bug is that the test for condition >> (b) in bdrv_reopen_prepare() that returns "backing is missing..." is >> using backing_file but it should use (correct me if I'm wrong) >> auto_backing_file. > > Well, I think both should be fine, because...
Why would both be fine? backing_file refers to the backing file currently attached, and auto_backing_file refers to the one written on the image metadata, or am I wrong? >> Not directly related to this, but should bdrv_backing_detach() also >> clear backing_file ? > > ...I don’t think it should. That’s what that my patch addresses. The > real problem is that bs->backing_file is not a cache for > bs->backing->bs->filename, so it shouldn’t be treated as such. But what's the point of having backing_file set if no backing file is attached? Berto
