On Fri, Feb 21, 2020 at 1:24 PM David Howells [off-list ref] wrote:

Jann Horn [off-list ref] wrote:

quoted

quoted

+ * Post mount notifications to all watches going rootwards along the tree.
+ *
+ * Must be called with the mount_lock held.

Please put such constraints into lockdep assertions instead of
comments; that way, violations can actually be detected.

What's the best way to write a lockdep assertion?

        BUG_ON(!lockdep_is_held(lock));

lockdep_assert_held(lock) is the normal way, I think - that will
WARN() if lockdep is enabled and the lock is not held.