ceph: fix NULL pointer deref when debugging is enabled

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 9f53c3d..7ae0f49 100644 (file)
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -928,7 +928,7 @@ ceph_direct_read_write(struct kiocb *iocb, struct iov_iter *iter,
 
        dout("sync_direct_%s on file %p %lld~%u snapc %p seq %lld\n",
             (write ? "write" : "read"), file, pos, (unsigned)count,
-            snapc, snapc->seq);
+            snapc, snapc ? snapc->seq : 0);
 
        ret = filemap_write_and_wait_range(inode->i_mapping,
                                           pos, pos + count - 1);