Re: [Y2038] [RFC 02/15] vfs: Change all structures to support 64 bit time

From: Arnd Bergmann
Date: Thu Jan 14 2016 - 17:54:47 EST

On Thursday 14 January 2016 23:46:16 Arnd Bergmann wrote:
> I'm not following the line of thought here. We have some users
> that want ext4 to mount old file system images without long
> inodes writable, because they don't care about the 2038 problem.
> We also have other users that want to force the same file system
> image to be read-only because they want to ensure that it does
> not stop working correctly when the time overflow happens while
> the fs is mounted.
> If you don't want a compile-time option for it, how do you suggest
> we decide which case we have?

In case that came across wrong, I'm assuming that the first
user also wants all the system calls enabled that pass 32-bit
time_t values, while the second one wants them all left out from
the kernel to ensure that no user space program gets incorrect
data. This could be done using a sysctl of course, but I still
think we want a compile-time option for the syscalls for clarity,
and I would simply use the same compile-time option to determine
the behavior of the file system, network protocols and device
drivers that deal with 32-bit timestamps outside of the kernel.