On Tue, Mar 31, 2020 at 03:35:36PM +0200, Linus Walleij wrote: > It was brought to my attention that this bug from 2018 was > still unresolved: 32 bit emulators like QEMU were given > 64 bit hashes when running 32 bit emulation on 64 bit systems. > > This adds a fcntl() operation to set the underlying filesystem > into 32bit mode even if the file hanle was opened using 64bit > mode without the compat syscalls. s/hanle/handle/ The API that you've proposed as a way to set the 32-bit mode, but there is no way to clear the 32-bit mode, nor there is a way to get the current status mode. My suggestion is to add a flag bit for F_GETFD and F_SETFD (set and get file descriptor flags). Currently the only file descriptor flag is FD_CLOEXEC, so why not add a FD_32BIT_MODE bit? Cheers, - Ted