fs: dcache reduce locking in d_alloc

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

1 files changed, 4 insertions, 2 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 98a05696593e..ccdc5c2512df 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1253,11 +1253,13 @@ struct dentry *d_alloc(struct dentry * parent, const struct qstr *name)
 
         if (parent) {
                 spin_lock(&parent->d_lock);
-                spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
+                /*
+                 * don't need child lock because it is not subject
+                 * to concurrency here
+                 */
                 dentry->d_parent = dget_dlock(parent);
                 dentry->d_sb = parent->d_sb;
                 list_add(&dentry->d_u.d_child, &parent->d_subdirs);
-                spin_unlock(&dentry->d_lock);
                 spin_unlock(&parent->d_lock);
         }