ceph: avoid invalid memory dereference in the middle of umount
extra_mon_dispatch() and debugfs' foo_show functions dereference
fsc->mdsc. we should clean up fsc->client->extra_mon_dispatch
and debugfs before destroying fsc->mds.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 0c05df4..666a9f2 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -3769,13 +3769,13 @@ static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
{
struct ceph_mds_client *mdsc = fsc->mdsc;
-
dout("mdsc_destroy %p\n", mdsc);
- ceph_mdsc_stop(mdsc);
/* flush out any connection work with references to us */
ceph_msgr_flush();
+ ceph_mdsc_stop(mdsc);
+
fsc->mdsc = NULL;
kfree(mdsc);
dout("mdsc_destroy %p done\n", mdsc);
