[PATCH 4.19 41/84] xprtrdma: Fix completion wait during device removal

Greg Kroah-Hartman
2020-01-16T23:29:00Z

From: Chuck Lever <chuck.lever@oracle.com>

commit 13cb886c591f341a8759f175292ddf978ef903a1 upstream.

I've found that on occasion, "rmmod <dev>" will hang while if an NFS
is under load.

Ensure that ri_remove_done is initialized only just before the
transport is woken up to force a close. This avoids the completion
possibly getting initialized again while the CM event handler is
waiting for a wake-up.

Fixes: bebd031866ca ("xprtrdma: Support unplugging an HCA from under an NFS mount")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/sunrpc/xprtrdma/verbs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -248,6 +248,7 @@ rpcrdma_conn_upcall(struct rdma_cm_id *i
ia->ri_device->name,
rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt));
#endif
+ init_completion(&ia->ri_remove_done);
set_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags);
ep->rep_connected = -ENODEV;
xprt_force_disconnect(&xprt->rx_xprt);
@@ -306,7 +307,6 @@ rpcrdma_create_id(struct rpcrdma_xprt *x
trace_xprtrdma_conn_start(xprt);

init_completion(&ia->ri_done);
- init_completion(&ia->ri_remove_done);

id = rdma_create_id(xprt->rx_xprt.xprt_net, rpcrdma_conn_upcall,
xprt, RDMA_PS_TCP, IB_QPT_RC);