Re: [for-6.13 PATCH 00/19] nfs/nfsd: fixes and improvements for LOCALIO

Chuck Lever III
2024-11-10T15:49:17Z

> On Nov 8, 2024, at 6:39 PM, Mike Snitzer <snitzer@kernel.org> wrote:
>
> Hi,
>
> I really wanted to post these patches at the beginning of the week (or
> sooner) but I had quite a few issues to work through. The biggest
> challenge came from trying to develop the final patch only to hit the
> wall of needing to find and fix memory corruption with the first
> patch.
>
> HUGE special thanks to NeilBrown for helping me identify the source of
> the NFSv3 LOCALIO memory corruption fixed by the first patch. Anna,
> we'd do well for that patch to land upstream for 6.12 final (but Trond
> if it slips to the 6.13 merge window pull that should be fine, as the
> Fixes: tag should get it to land in 6.12-stable).
>
> The 2nd patch is also a fundamental fix but it is kernel config
> dependant on whether you'll experience the RCU splat it fixes.
>
> Patches 3 - 6 are cleanups I've been carrying since just after the
> 6.12 merge window.
>
> Patch 7 adds a 'localio_O_DIRECT_semantics' nfs module parameter that
> when set will allow the use of O_DIRECT from the LOCALIO client
> through to the underlying filesystem.
>
> Patches 8 and beyond are dealing with the leftover bake-a-thon
> business of switching from caching LOCALIO's open nfsd_file in the
> server to doing so in the client. Definitely took some effort but the
> end result is working really well.
>
> This is quite a bit of change at the end of the 6.13 development
> window, but I _think_ it worthy of considersation for 6.13 (the bulk
> of the changes are confined to fs/nfs/localio.c and
> fs/nfs_common/nfslocalio.c which are only built if LOCALIO Kconfig
> options enabled (even general NFS code paths are all wrapped with
> CONFIG_NFS_LOCALIO).
>
> I'm happy to work through any issues found in review with urgency next
> week (or this weekend if others are interested to look and happen to
> find something).
>
> Happy to take it as it comes, I'm in no way _pushing_ for these
> changes to land for 6.13. I'm just now comfortable posting them for
> serious consideration.

Hey Mike -

I'd like to see patches 7ff get an unhurried review and then
spend a few weeks in fs-next and/or linux-next. I don't have
any objection to moving forward quickly with 1 - 6.

--
Chuck Lever