From 3e339f964b74b7223ab128f36f4b2aaf9dc12eb9 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 30 Jul 2014 08:27:09 -0400 Subject: [PATCH] nfsd: Ensure lookup_clientid() takes client_lock Ensure that the client lookup is done safely under the client_lock, so we're not relying on the client_mutex. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4state.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 68383b09c7dc..f9d077d800ee 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -3451,13 +3451,17 @@ static __be32 lookup_clientid(clientid_t *clid, * will be false. */ WARN_ON_ONCE(cstate->session); + spin_lock(&nn->client_lock); found = find_confirmed_client(clid, false, nn); - if (!found) + if (!found) { + spin_unlock(&nn->client_lock); return nfserr_expired; + } + atomic_inc(&found->cl_refcount); + spin_unlock(&nn->client_lock); /* Cache the nfs4_client in cstate! */ cstate->clp = found; - atomic_inc(&found->cl_refcount); return nfs_ok; }