[PATCH] UBI: add a ubi forced detach ioctl

[Artem Bityutskiy]

On Mon, 2014-05-12 at 12:44 +0200, Luka Perkov wrote:
> When running ubi rootfs upgrade on nand based OpenWrt device after
> pivot_root init process is still "hooked" on the old file system. Thus,
> the old file system can not be umounted. If the filesystem is mounted it
> can not be upgraded with using for example ubiupdatevol or removed with
> ubirmvol. Forcing umount would allow to run the before mentioned
> commands.

Generally, a change like this may be fine, but I'd like to see more
detailed description and analysis, which points to how other kernel
subsystems deal with this.

-- 
Best Regards,
Artem Bityutskiy