ceph: don't try fill file_lock on unsuccessful GETFILELOCK reply

commit 28a282616f56990547b9dcd5c6fbd2001344664c upstream.

When ceph_mdsc_do_request returns an error, we can't assume that the
filelock_reply pointer will be set. Only try to fetch fields out of
the r_reply_info when it returns success.

Cc: stable@vger.kernel.org
Reported-by: Hector Martin <hector@marcansoft.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c
index e7cce412f2cf7b5362606f2286291290a218b9c8..cb647c8c7b685ca2e54716401d0d5902905b8f59 100644 (file)
--- a/fs/ceph/locks.c
+++ b/fs/ceph/locks.c
@@ -78,8 +78,7 @@ static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
                req->r_wait_for_completion = ceph_lock_wait_for_completion;
 
        err = ceph_mdsc_do_request(mdsc, inode, req);
-
-       if (operation == CEPH_MDS_OP_GETFILELOCK) {
+       if (!err && operation == CEPH_MDS_OP_GETFILELOCK) {
                fl->fl_pid = -le64_to_cpu(req->r_reply_info.filelock_reply->pid);
                if (CEPH_LOCK_SHARED == req->r_reply_info.filelock_reply->type)
                        fl->fl_type = F_RDLCK;