diff options
| author | Tejun Heo | 2014-02-03 14:02:59 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2014-02-07 15:42:40 -0800 |
| commit | 182fd64b66342219d6fcf2b84d337529d120d95c (patch) | |
| tree | f8e0377fa5cdf90ea11245fd4f028c07ada4a5cd | |
| parent | 988cd7afb3f37598891ca70b4c6eb914c338c46a (diff) | |
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>
| -rw-r--r-- | fs/kernfs/dir.c | 20 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 1 |
2 files changed, 13 insertions, 8 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 948551d222b4..5cf137b63db9 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -22,6 +22,15 @@ DEFINE_MUTEX(kernfs_mutex); #define rb_to_kn(X) rb_entry((X), struct kernfs_node, rb) +static bool kernfs_lockdep(struct kernfs_node *kn) +{ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + return kn->flags & KERNFS_LOCKDEP; +#else + return false; +#endif +} + /** * kernfs_name_hash * @name: Null terminated string to hash @@ -144,7 +153,7 @@ struct kernfs_node *kernfs_get_active(struct kernfs_node *kn) if (!atomic_inc_unless_negative(&kn->active)) return NULL; - if (kn->flags & KERNFS_LOCKDEP) + if (kernfs_lockdep(kn)) rwsem_acquire_read(&kn->dep_map, 0, 1, _RET_IP_); return kn; } @@ -164,7 +173,7 @@ void kernfs_put_active(struct kernfs_node *kn) if (unlikely(!kn)) return; - if (kn->flags & KERNFS_LOCKDEP) + if (kernfs_lockdep(kn)) rwsem_release(&kn->dep_map, 1, _RET_IP_); v = atomic_dec_return(&kn->active); if (likely(v != KN_DEACTIVATED_BIAS)) @@ -190,16 +199,13 @@ static void kernfs_deactivate(struct kernfs_node *kn) lockdep_assert_held(&kernfs_mutex); BUG_ON(!(kn->flags & KERNFS_REMOVED)); - if (!(kernfs_type(kn) & KERNFS_ACTIVE_REF)) - return; - /* only the first invocation on @kn should deactivate it */ if (atomic_read(&kn->active) >= 0) atomic_add(KN_DEACTIVATED_BIAS, &kn->active); mutex_unlock(&kernfs_mutex); - if (kn->flags & KERNFS_LOCKDEP) { + if (kernfs_lockdep(kn)) { rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_); if (atomic_read(&kn->active) != KN_DEACTIVATED_BIAS) lock_contended(&kn->dep_map, _RET_IP_); @@ -209,7 +215,7 @@ static void kernfs_deactivate(struct kernfs_node *kn) wait_event(root->deactivate_waitq, atomic_read(&kn->active) == KN_DEACTIVATED_BIAS); - if (kn->flags & KERNFS_LOCKDEP) { + if (kernfs_lockdep(kn)) { lock_acquired(&kn->dep_map, _RET_IP_); rwsem_release(&kn->dep_map, 1, _RET_IP_); } diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index 38646f6096bc..dc4cd6c04236 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -35,7 +35,6 @@ enum kernfs_node_type { }; #define KERNFS_TYPE_MASK 0x000f -#define KERNFS_ACTIVE_REF KERNFS_FILE #define KERNFS_FLAG_MASK ~KERNFS_TYPE_MASK enum kernfs_node_flag { |