xprtrdma: Fix completion wait during device removal

BugLink: https://bugs.launchpad.net/bugs/1861934
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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 0829c0a503b6d025c46c02accbb018b6a8d61f5a..b7eed2c54db176ce4ab0fc20a33a4028c5b68d27 100644 (file)
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -250,6 +250,7 @@ rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
                        ia->ri_device->name,
                        sap, rpc_get_port(sap));
 #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);
@@ -305,7 +306,6 @@ rpcrdma_create_id(struct rpcrdma_xprt *xprt,
        int rc;
 
        init_completion(&ia->ri_done);
-       init_completion(&ia->ri_remove_done);
 
        id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
                            IB_QPT_RC);