Re: [PATCH v2] fuse: invalidate readdir cache on epoch bump

[Luis Henriques <luis@igalia.com>]

On Fri, May 15 2026, Jun Wu wrote:

> Thanks for your review! I think my DNS records had expired when sending,
> and retrying after fixing the DNS didn't help. I will resend with a regular
> Gmail address.

Awesome, thanks.  I can confirm v3 is now on the mailing-list, though this
email I'm replying to seems to have been dropped again :-)

Cheers,
-- 
Luís


>
> Regards,
> Jun
>
> On Fri, May 15, 2026 at 9:26 AM Luis Henriques <luis@igalia.com> wrote:
>
>> On Fri, May 15 2026, Joanne Koong wrote:
>>
>> > On Fri, May 15, 2026 at 1:53 AM Luis Henriques <luis@igalia.com> wrote:
>> >>
>> >> On Thu, May 14 2026, Jun Wu wrote:
>> >>
>> >> > From: Jun Wu <quark@meta.com>
>> >> >
>> >> > FUSE_NOTIFY_INC_EPOCH invalidates dentries, but does not invalidate
>> cached
>> >> > readdir results. A process with cwd inside a FUSE mount can therefore
>> >> > observe stale readdir(".") output after an epoch bump.
>> >> >
>> >> > Fix this by recording epoch in the readdir cache and checking it on
>> reuse.
>> >> >
>> >> > Minimal reproducer:
>> >> >
>> >> > - mount a tiny FUSE fs with an empty root directory
>> >> > - on opendir, enable fi->cache_readdir and fi->keep_cache
>> >> > - chdir into the mount and call readdir(".") to populate readdir cache
>> >> > - make the FUSE server report one file in the root directory
>> >> > - send only FUSE_NOTIFY_INC_EPOCH
>> >> > - call readdir(".") again; before this change it stays stale, after
>> this
>> >> >   change it sees the new file
>> >> >
>> >> > Fixes: 2396356a945b ("fuse: add more control over cache invalidation
>> behaviour")
>> >> > Signed-off-by: Jun Wu <quark@meta.com>
>> >
>> > Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
>> >
>> > (btw, I think your v2 email may have gotten corrupted when sending. I
>> > wasn't able to find it in my inbox and had to manually import Luis's.
>> > I'm not seeing it show up on lore [1] either)
>>
>> Hmm... yeah, looks like there's something funny with his email.  The mail
>> server I use seems to be more tolerant than lore regarding incorrect
>> email.  So maybe lore blocked it because the domain and the smtp server
>> address don't match...?  Anyway, maybe it's worth resending so that
>> everyone can see it.
>>
>> Cheers,
>> --
>> Luís
>>
>
>
> -- 
> WU Jun
> <quark@lihdd.net>