diff options
| author | Yan, Zheng <zheng.z.yan@intel.com> | 2014-03-24 09:56:43 +0800 |
|---|---|---|
| committer | Sage Weil <sage@inktank.com> | 2014-04-04 21:07:17 -0700 |
| commit | 00bd8edb861eb41d274938cfc0338999d9c593a3 (patch) | |
| tree | f924d27c0651107432a5fb6505ead522c65cc8fe | |
| parent | d90deda69cb82411ba7d990e97218e0f8b2d07bb (diff) | |
ceph: fix null pointer dereference in discard_cap_releases()
send_mds_reconnect() may call discard_cap_releases() after all
release messages have been dropped by cleanup_cap_releases()
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
| -rw-r--r-- | fs/ceph/mds_client.c | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index f260bd8d61cd..77640ada487a 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -1462,15 +1462,18 @@ static void discard_cap_releases(struct ceph_mds_client *mdsc, dout("discard_cap_releases mds%d\n", session->s_mds); - /* zero out the in-progress message */ - msg = list_first_entry(&session->s_cap_releases, - struct ceph_msg, list_head); - head = msg->front.iov_base; - num = le32_to_cpu(head->num); - dout("discard_cap_releases mds%d %p %u\n", session->s_mds, msg, num); - head->num = cpu_to_le32(0); - msg->front.iov_len = sizeof(*head); - session->s_num_cap_releases += num; + if (!list_empty(&session->s_cap_releases)) { + /* zero out the in-progress message */ + msg = list_first_entry(&session->s_cap_releases, + struct ceph_msg, list_head); + head = msg->front.iov_base; + num = le32_to_cpu(head->num); + dout("discard_cap_releases mds%d %p %u\n", + session->s_mds, msg, num); + head->num = cpu_to_le32(0); + msg->front.iov_len = sizeof(*head); + session->s_num_cap_releases += num; + } /* requeue completed messages */ while (!list_empty(&session->s_cap_releases_done)) { |