kernfs: replace kernfs_node->u.completion with kernfs_root->deactivate_waitq

[karo-tx-linux.git] / fs / kernfs / dir.c

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 5104cf5d25c5af6d28996bbe9b4a00700bf4479c..2193d30156efeaf1bf07a772e9fee731f3d6f40d 100644 (file)
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -8,6 +8,7 @@
  * This file is released under the GPLv2.
  */
 
+#include <linux/sched.h>
 #include <linux/fs.h>
 #include <linux/namei.h>
 #include <linux/idr.h>
@@ -151,6 +152,7 @@ struct kernfs_node *kernfs_get_active(struct kernfs_node *kn)
  */
 void kernfs_put_active(struct kernfs_node *kn)
 {
+       struct kernfs_root *root = kernfs_root(kn);
        int v;
 
        if (unlikely(!kn))
@@ -162,11 +164,7 @@ void kernfs_put_active(struct kernfs_node *kn)
        if (likely(v != KN_DEACTIVATED_BIAS))
                return;
 
-       /*
-        * atomic_dec_return() is a mb(), we'll always see the updated
-        * kn->u.completion.
-        */
-       complete(kn->u.completion);
+       wake_up_all(&root->deactivate_waitq);
 }
 
 /**
@@ -177,29 +175,29 @@ void kernfs_put_active(struct kernfs_node *kn)
  */
 static void kernfs_deactivate(struct kernfs_node *kn)
 {
-       DECLARE_COMPLETION_ONSTACK(wait);
-       int v;
+       struct kernfs_root *root = kernfs_root(kn);
 
        BUG_ON(!(kn->flags & KERNFS_REMOVED));
 
        if (!(kernfs_type(kn) & KERNFS_ACTIVE_REF))
                return;
 
-       kn->u.completion = (void *)&wait;
+       if (kn->flags & KERNFS_LOCKDEP)
+               rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_);
 
-       rwsem_acquire(&kn->dep_map, 0, 0, _RET_IP_);
-       /* atomic_add_return() is a mb(), put_active() will always see
-        * the updated kn->u.completion.
-        */
-       v = atomic_add_return(KN_DEACTIVATED_BIAS, &kn->active);
+       atomic_add(KN_DEACTIVATED_BIAS, &kn->active);
 
-       if (v != KN_DEACTIVATED_BIAS) {
+       if ((kn->flags & KERNFS_LOCKDEP) &&
+           atomic_read(&kn->active) != KN_DEACTIVATED_BIAS)
                lock_contended(&kn->dep_map, _RET_IP_);
-               wait_for_completion(&wait);
-       }
 
-       lock_acquired(&kn->dep_map, _RET_IP_);
-       rwsem_release(&kn->dep_map, 1, _RET_IP_);
+       wait_event(root->deactivate_waitq,
+                  atomic_read(&kn->active) == KN_DEACTIVATED_BIAS);
+
+       if (kn->flags & KERNFS_LOCKDEP) {
+               lock_acquired(&kn->dep_map, _RET_IP_);
+               rwsem_release(&kn->dep_map, 1, _RET_IP_);
+       }
 }
 
 /**
@@ -626,6 +624,7 @@ struct kernfs_root *kernfs_create_root(struct kernfs_dir_ops *kdops, void *priv)
 
        root->dir_ops = kdops;
        root->kn = kn;
+       init_waitqueue_head(&root->deactivate_waitq);
 
        return root;
 }