> I was following previous discussions in the mailing list and found that
> caching mechanism affected hlfsd behavior. It looks like the problem was
> resolved by updating mtime on every access. But still caching will lead
> to a problem if two accesses are taking place in same jiffy.
Yes, because the the nfs client is broken in this respect. noac
should mean noac, but the nfs client will still cache attributes if the
second access happens within the same jiffy as the previous access which
updated the attribute cache.
Replacing a couple of time_after() calls with time_after_eq() calls
fixes the issue, at least for hlfsd. Of course, running with noac might
be very much unacceptable if all you want is to avoid caching symlinks.
> We are considering following design strategy to implement the parameter.
> 1. Make nfs_symlink_caching dynamically tunable using /proc and sysctl
No. Do it on a per-mount basis, like the other OS's do.
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