NFS: Slow down state manager after an unhandled error

If the state manager thread is not actually able to fully recover from
some situation, it wakes up waiters, who kick off a new state manager
thread.  Quite often the fresh invocation of the state manager is just
as successful.

This results in a livelock as the client dumps thousands of NFS
requests a second on the network in a vain attempt to recover.  Not
very friendly.

To mitigate this situation, add a delay in the state manager after
an unhandled error, so that the client sends just a few requests
every second in this case.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2012-09-14 17:23:23 -04:00 коммит произвёл Trond Myklebust
Родитель 8cb7f74eee
Коммит ffe5a83005
1 изменённых файлов: 1 добавлений и 0 удалений

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@ -2015,6 +2015,7 @@ out_error:
pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
" with error %d\n", section_sep, section,
clp->cl_hostname, -status);
ssleep(1);
nfs4_end_drain_session(clp);
nfs4_clear_state_manager_bit(clp);
}