NFSv4: Add lockdep checks to nfs4_wait_clnt_recover()

Attempt to detect deadlocks due to caller holding locks on clp->cl_sem

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 35bfcce..1712d03 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2711,11 +2711,15 @@ static int nfs4_wait_clnt_recover(struct rpc_clnt *clnt, struct nfs_client *clp)
 
        might_sleep();
 
+       rwsem_acquire(&clp->cl_sem.dep_map, 0, 0, _RET_IP_);
+
        rpc_clnt_sigmask(clnt, &oldset);
        res = wait_on_bit(&clp->cl_state, NFS4CLNT_STATE_RECOVER,
                        nfs4_wait_bit_interruptible,
                        TASK_INTERRUPTIBLE);
        rpc_clnt_sigunmask(clnt, &oldset);
+
+       rwsem_release(&clp->cl_sem.dep_map, 1, _RET_IP_);
        return res;
 }