illumos gate

During some testing I noticed that the first nfsauth_retrieve() from nfsauth_cache_get() is never cached, so for every client I saw two nfsauth_retrieve() calls.

The problem is easily reproducible. Just make sure the nfsauth cache is clean by either unshare and share a dataset, or simply restart the nfs/server SMF service. Then initiate some NFS traffic from one client. You will see this on the server:

# dtrace -n 'nfsauth_retrieve:entry{}'
dtrace: description 'nfsauth_retrieve:entry' matched 1 probe
CPU     ID                    FUNCTION:NAME
  0  62384           nfsauth_retrieve:entry
  0  62384           nfsauth_retrieve:entry

The root cause is here in nfsauth_cache_get() - there are missing curly braces:

1018            /*
1019             * If we failed to preallocate the memory for
1020             * supplemental groups, we won't cache the retrieved
1021             * data.
1022             */
1023            if (p->auth_clnt_ngids != 0 &&
1024                p->auth_clnt_gids == NULL)
1025                p->auth_clnt_ngids = 0;
1026                mutex_exit(&p->auth_lock);
1027
1028                p = NULL;
1029
1030                goto retrieve;

Fortunately, this issue is mostly harmless. It have only small performance impact.