From: tsutomu.owa@toshiba.co.jp <tsutomu.owa@toshiba.co.jp>
Date: Tue, 12 Sep 2017 09:01:46 +0000 (+0000)
Subject: DLM: fix overflow dlm_cb_seq
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ccbbea04326e061651e0b38eda0792c758ce4f91;p=linux.git

DLM: fix overflow dlm_cb_seq

dlm_cb_seq is 64 bits. If dlm_cb_seq overflows and returns to 0,
dlm_rem_lkb_callback() will not work properly.

Signed-off-by: Tadashi Miyauchi <miyauchi@toshiba-tops.co.jp>
Signed-off-by: Tsutomu Owa <tsutomu.owa@toshiba.co.jp>
Signed-off-by: David Teigland <teigland@redhat.com>
---

diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index 07fed838d8fdd..562fa8c3edff3 100644
--- a/fs/dlm/ast.c
+++ b/fs/dlm/ast.c
@@ -181,6 +181,8 @@ void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status,
 
 	spin_lock(&dlm_cb_seq_spin);
 	new_seq = ++dlm_cb_seq;
+	if (!dlm_cb_seq)
+		new_seq = ++dlm_cb_seq;
 	spin_unlock(&dlm_cb_seq_spin);
 
 	if (lkb->lkb_flags & DLM_IFL_USER) {