Mark Lord wrote:..
One candidate might seem to be the existing /sys/block/dev/partition/start
which I expect is already 64-bit friendly.
But this requires about 150 lines of somewhat complex C code to access,
using only the dev_t (from stat(2) on a file) as a starting point,
or less if one relies upon the udev device name matching the sysfs device name.
Is it time now for HDIO_GETGEO64 to make an appearance?
Similar to how the existing BLKGETSIZE64 is supplanting BLKGETSIZE ?
Probably a better thing to have would be a way to look up block devices in sysfs by device number.
Instead, software has to search everything inside /sys/block/..
looking for a "dev" file whose contents match,
rather than just trying to access something like this:
/sys/block/8:1/start
or
/sys/block/majors/8/minors/1/start
Or any one of a number of similar ways to arrange it.