Hi
I have a report of a the BUG_ON in rpcb_getport_clnt being
triggered. This is:
/* Autobind on cloned rpc clients is discouraged */
BUG_ON(clnt->cl_parent != clnt);
It looks to me that while they might be discouraged, they are not
prevented and so having the BUG_ON is wrong.
When rpc_clone_client creates a clone, it sets cl_autobind to 0,
and gives the new client a reference to the same cl_xprt as the
original client.
The only effect of cl_autobind is to prevent rpc_force_rebind from
clearing the BOUND flag on ->cl_xprt.
So while a call to rpc_force_rebind on the clone will not clear that
flag, a call on the original client will clear that flag.
So a cloned client can still end up with a ->cl_xprt with the BOUND
flag clear.
So call_bind (which is present in the call trace under the oops) can
find that !xprt_bound, even when the client is a cloned client.
When this happens, ->rpcbind, which is rpcb_getport_clnt, goes BOOM.
What should happen when a clone client finds that its transport is no
longer bound? Should rpc_getport_async just do
clnt = task->tk_client->cl_parent;
??
Perplexed,
NeilBrown
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