kernfs: remove KERNFS_ACTIVE_REF and add kernfs_lockdep()
There currently are two mechanisms gating active ref lockdep
annotations - KERNFS_LOCKDEP flag and KERNFS_ACTIVE_REF type mask.
The former disables lockdep annotations in kernfs_get/put_active()
while the latter disables all of kernfs_deactivate().
While KERNFS_ACTIVE_REF also behaves as an optimization to skip the
deactivation step for non-file nodes, the benefit is marginal and it
needlessly diverges code paths. Let's drop KERNFS_ACTIVE_REF.
While at it, add a test helper kernfs_lockdep() to test KERNFS_LOCKDEP
flag so that it's more convenient and the related code can be compiled
out when not enabled.
v2: Refreshed on top of ("kernfs: make kernfs_deactivate() honor
KERNFS_LOCKDEP flag"). As the earlier patch already added
KERNFS_LOCKDEP tests to kernfs_deactivate(), those additions are
dropped from this patch and the existing ones are simply converted
to kernfs_lockdep().
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2 files changed