[PATCH 22/46] fs: dcache reduce locking in d_alloc

[Nick Piggin]

Signed-off-by: Nick Piggin <npiggin@xxxxxxxxx>
---
 fs/dcache.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index a117139..3e4f7c1 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1220,11 +1220,13 @@ 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);
 	}
 
-- 
1.7.1

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