Re: [PATCH v5 2/2] tmpfs: Support 64-bit inums per-sb

Chris Down
2020-01-07T00:16:47Z

Dave Chinner writes:
>It took 15 years for us to be able to essentially deprecate
>inode32 (inode64 is the default behaviour), and we were very happy
>to get that albatross off our necks. In reality, almost everything
>out there in the world handles 64 bit inodes correctly
>including 32 bit machines and 32bit binaries on 64 bit machines.
>And, IMNSHO, there no excuse these days for 32 bit binaries that
>don't using the *64() syscall variants directly and hence support
>64 bit inodes correctlyi out of the box on all platforms.
>
>I don't think we should be repeating past mistakes by trying to
>cater for broken 32 bit applications on 64 bit machines in this day
>and age.

I'm very glad to hear that. I strongly support moving to 64-bit inums in all
cases if there is precedent that it's not a compatibility issue, but from the
comments on my original[0] patch (especially that they strayed from the
original patches' change to use ino_t directly into slab reuse), I'd been given
the impression that it was known to be one.

From my perspective I have no evidence that inode32 is needed other than the
comment from Jeff above get_next_ino. If that turns out not to be a problem, I
am more than happy to just wholesale migrate 64-bit inodes per-sb in tmpfs.

0: https://lore.kernel.org/patchwork/patch/1170963/