From c0bd50e2eeddf139d8f61e709d7003210301e93a Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Tue, 7 Apr 2015 15:51:08 +0800 Subject: [PATCH] ceph: fix null pointer dereference in send_mds_reconnect() sb->s_root can be null when umounting Signed-off-by: Yan, Zheng --- fs/ceph/mds_client.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index fd5585b8d382..0a2eb32ffe43 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -2892,7 +2892,8 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, spin_unlock(&session->s_cap_lock); /* trim unused caps to reduce MDS's cache rejoin time */ - shrink_dcache_parent(mdsc->fsc->sb->s_root); + if (mdsc->fsc->sb->s_root) + shrink_dcache_parent(mdsc->fsc->sb->s_root); ceph_con_close(&session->s_con); ceph_con_open(&session->s_con, -- 2.20.1