From bd1441b92e31cd3c01cc2453aa627d139a1207f7 Mon Sep 17 00:00:00 2001 From: Niu Yawei Date: Fri, 23 Sep 2016 00:06:25 -0400 Subject: [PATCH] LU-7903 ptlrpc: leaked rs on difficult reply reply_out_callback() should call ptlrpc_schedule_difficult_reply() to finalize the rs if it's already not on uncommitted list, otherwise, the rs and the export held by rs could be leaked: - target_send_reply() sends a difficult reply before the transaction committed, the reply is linked to scp_rep_active; - export gets disconnected by umount or whatever reason, server_disconnect_export() is called to complete all outstanding replies, which will calls into ptlrpc_handle_rs() to dispose of the rs, so the rs is removed from the uncommitted list and LNetMDUnlink() is called to unlink the reply buffer and generate an unlink event; - reply_out_callback() is called to process above unlink event, ptlrpc_schedule_difficult_reply() is supposed to be called to dispose of the rs finally. However, it could be skipped because of following flawed code snippet: if (!rs->rs_no_ack || rs->rs_transno <= rs->rs_export->exp_obd->obd_last_committed) ptlrpc_schedule_difficult_reply(rs); The intention of above code is: if rs_no_ack is true (COS enabled), and transaction is not committed, we should rely on commit callback to release the rs. However, it overlooked the situation that rs could have been removed from the uncommitted list by disconnecting export. Signed-off-by: Niu Yawei Change-Id: I76d1a9e08c94340520fb731e8671b7b9205e0eb1 Reviewed-on: http://review.whamcloud.com/22696 Reviewed-by: Andreas Dilger Tested-by: Jenkins Tested-by: Maloo Reviewed-by: Lai Siyao Reviewed-by: Oleg Drokin --- lustre/ptlrpc/events.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/lustre/ptlrpc/events.c b/lustre/ptlrpc/events.c index 0c975b1..3855b3b 100644 --- a/lustre/ptlrpc/events.c +++ b/lustre/ptlrpc/events.c @@ -414,7 +414,8 @@ void reply_out_callback(lnet_event_t *ev) rs->rs_on_net = 0; if (!rs->rs_no_ack || rs->rs_transno <= - rs->rs_export->exp_obd->obd_last_committed) + rs->rs_export->exp_obd->obd_last_committed || + list_empty(&rs->rs_obd_list)) ptlrpc_schedule_difficult_reply(rs); spin_unlock(&rs->rs_lock); -- 1.8.3.1