fs: dcache scale dentry refcount

Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

1 files changed, 0 insertions, 2 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 746055b214d7..eb7af39350c6 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3655,9 +3655,7 @@ again:
         list_del(&cgrp->sibling);
         cgroup_unlock_hierarchy(cgrp->root);
 
-        spin_lock(&cgrp->dentry->d_lock);
         d = dget(cgrp->dentry);
-        spin_unlock(&d->d_lock);
 
         cgroup_d_remove_dir(d);
         dput(d);