Hi! Even with fe6a8fc5ed2f0081f17375ae2005718522c392c6 the LOOP_CONFIGURE ioctl doesn't work correctly. It gets confused if the lo_offset/lo_sizelimit fields are set to non-zero.
In a quick test I ran (on Linux 5.8.3) I call LOOP_CONFIGURE with .lo_offset=3221204992 and .lo_sizelimit=50331648 and immediately verify the size of the block device with BLKGETSIZE64. It should of course return 50331648, but actually returns 3271557120. (the precise values have no particular relevance, it's just what I happened to use in my test.) If I instead use LOOP_SET_STATUS64 with the exact same parameters, everything works correctly. In either case, if I use LOOP_GET_STATUS64 insted of BLKGETSIZE64 to verify things, everything looks great. My guess is that the new ioctl simply doesn't properly propagate the size limit into the underlying block device like it should. I didn't have the time to investigate further though. Lennart
