4.16-stable review patch. If anyone has any objections, please let me know.
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From: Long Li longli@microsoft.com
commit 48f238a79f668f8ff013024d83010de551833d7f upstream.
During transport reconnect, other processes may have registered memory and blocked on transport. This creates a deadlock situation because the transport resources can't be freed, and reconnect is blocked.
Fix this by returning to upper layer on timeout. Before returning, transport status is set to reconnecting so other processes will release memory registration resources.
Upper layer will retry the reconnect. This is not in fast I/O path so setting the timeout to 5 seconds.
Signed-off-by: Long Li longli@microsoft.com Signed-off-by: Steve French smfrench@gmail.com Reviewed-by: Ronnie Sahlberg lsahlber@redhat.com CC: Stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/cifs/smbdirect.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
--- a/fs/cifs/smbdirect.c +++ b/fs/cifs/smbdirect.c @@ -1498,8 +1498,8 @@ int smbd_reconnect(struct TCP_Server_Inf log_rdma_event(INFO, "reconnecting rdma session\n");
if (!server->smbd_conn) { - log_rdma_event(ERR, "rdma session already destroyed\n"); - return -EINVAL; + log_rdma_event(INFO, "rdma session already destroyed\n"); + goto create_conn; }
/* @@ -1512,15 +1512,19 @@ int smbd_reconnect(struct TCP_Server_Inf }
/* wait until the transport is destroyed */ - wait_event(server->smbd_conn->wait_destroy, - server->smbd_conn->transport_status == SMBD_DESTROYED); + if (!wait_event_timeout(server->smbd_conn->wait_destroy, + server->smbd_conn->transport_status == SMBD_DESTROYED, 5*HZ)) + return -EAGAIN;
destroy_workqueue(server->smbd_conn->workqueue); kfree(server->smbd_conn);
+create_conn: log_rdma_event(INFO, "creating rdma session\n"); server->smbd_conn = smbd_get_connection( server, (struct sockaddr *) &server->dstaddr); + log_rdma_event(INFO, "created rdma session info=%p\n", + server->smbd_conn);
return server->smbd_conn ? 0 : -ENOENT; }