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, 1 insertions, 1 deletions

diff --git a/fs/namei.c b/fs/namei.c
index f3b5ca404659..cbfa5fb31072 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2133,7 +2133,7 @@ void dentry_unhash(struct dentry *dentry)
         shrink_dcache_parent(dentry);
         spin_lock(&dcache_lock);
         spin_lock(&dentry->d_lock);
-        if (atomic_read(&dentry->d_count) == 2)
+        if (dentry->d_count == 2)
                 __d_drop(dentry);
         spin_unlock(&dentry->d_lock);
         spin_unlock(&dcache_lock);