From b2a6662932c52304eee11323701f8a01aa110e37 Mon Sep 17 00:00:00 2001
From: "tsutomu.owa@toshiba.co.jp" <tsutomu.owa@toshiba.co.jp>
Date: Tue, 12 Sep 2017 08:55:50 +0000
Subject: [PATCH 06/19] DLM: fix race condition between dlm_send and dlm_recv
Git-commit: b2a6662932c52304eee11323701f8a01aa110e37
Patch-mainline: v4.15-rc1
References: bsc#1074590
When kernel_sendpage(in send_to_sock) and kernel_recvmsg
(in receive_from_sock) return error, close_connection may works at the
same time. At that time, they may wait for each other by cancel_work_sync.
Signed-off-by: Tadashi Miyauchi <miayuchi@toshiba-tops.co.jp>
Signed-off-by: Tsutomu Owa <tsutomu.owa@toshiba.co.jp>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Gang He <ghe@suse.com>
---
fs/dlm/lowcomms.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index 980c58b..420946d 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -110,6 +110,7 @@ struct connection {
#define CF_IS_OTHERCON 5
#define CF_CLOSE 6
#define CF_APP_LIMITED 7
+#define CF_CLOSING 8
struct list_head writequeue; /* List of outgoing writequeue_entries */
spinlock_t writequeue_lock;
int (*rx_action) (struct connection *); /* What to do when active */
@@ -581,9 +582,11 @@ static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
static void close_connection(struct connection *con, bool and_other,
bool tx, bool rx)
{
- if (tx && cancel_work_sync(&con->swork))
+ bool closing = test_and_set_bit(CF_CLOSING, &con->flags);
+
+ if (tx && !closing && cancel_work_sync(&con->swork))
log_print("canceled swork for node %d", con->nodeid);
- if (rx && cancel_work_sync(&con->rwork))
+ if (rx && !closing && cancel_work_sync(&con->rwork))
log_print("canceled rwork for node %d", con->nodeid);
mutex_lock(&con->sock_mutex);
@@ -603,6 +606,7 @@ static void close_connection(struct connection *con, bool and_other,
con->retries = 0;
mutex_unlock(&con->sock_mutex);
+ clear_bit(CF_CLOSING, &con->flags);
}
/* Data received from remote end */
--
1.8.5.6