From 6d769f1e1420179d1f83cf1a9cdc585b46c28545 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 13 Nov 2013 09:08:21 -0500 Subject: [PATCH] nfs: don't retry detect_trunking with RPC_AUTH_UNIX more than once Currently, when we try to mount and get back NFS4ERR_CLID_IN_USE or NFS4ERR_WRONGSEC, we create a new rpc_clnt and then try the call again. There is no guarantee that doing so will work however, so we can end up retrying the call in an infinite loop. Worse yet, we create the new client using rpc_clone_client_set_auth, which creates the new client as a child of the old one. Thus, we can end up with a *very* long lineage of rpc_clnts. When we go to put all of the references to them, we can end up with a long call chain that can smash the stack as each rpc_free_client() call can recurse back into itself. This patch fixes this by simply ensuring that the SETCLIENTID call will only be retried in this situation if the last attempt did not use RPC_AUTH_UNIX. Note too that with this change, we don't need the (i > 2) check in the -EACCES case since we now have a more reliable test as to whether we should reattempt. Cc: stable@vger.kernel.org # v3.10+ Cc: Chuck Lever Tested-by/Acked-by: Weston Andros Adamson Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index c8e729deb4f7..6f0470667f95 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -2093,10 +2093,15 @@ again: nfs4_root_machine_cred(clp); goto again; } - if (i > 2) + if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) break; case -NFS4ERR_CLID_INUSE: case -NFS4ERR_WRONGSEC: + /* No point in retrying if we already used RPC_AUTH_UNIX */ + if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) { + status = -EPERM; + break; + } clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX); if (IS_ERR(clnt)) { status = PTR_ERR(clnt);