Re: API break, sysfs "capability" file

[Christoph Hellwig]

On Wed, Apr 17, 2024 at 05:48:16PM +0200, Lennart Poettering wrote:
> Block devices with part scanning off are quite common after all,
> i.e. "losetup" creates them by default like that, and partition block
> devices themselves have no part scanning on and so on, hence we have
> to be ablet to operate sanely with them.

Maybe and ioctl to turn on partition scanning if it is currently disabled
or return an error otherwise would be the better thing?  It would
do the right thing for the most common loop case, and with a bit more
work could do the right thing for those that more or less disable it
graciously (ubiblock, drbd, zram) and would just fail for those who are
so grotty old code and slow devices that we never want to do a partition
scan (basically old floppy drivers and the Nintendo N64 cartridge driver)