> > This looks like a false positive because lockdep is not aware of > > s_stack_depth of the file (fs) associated with the pipe. > > There must be some annotation to tell lockdep about this. > It's a long story that can be summed up as "not simple": https://lkml.org/lkml/2017/9/21/63 Overlayfs annotates inode mutex in lockdep friendly manner. This is why you see: (&ovl_i_mutex_key[depth]){+.+.}, at: inode_lock But this does not extend to other locks that may be associated with filesystem or blockdev objects (e.g. pipe_lock()) and does not cover the case of stacked blockdev (e.g. loop). Thanks, Amir.