Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin

* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
  fs: scale mntget/mntput
  fs: rename vfsmount counter helpers
  fs: implement faster dentry memcmp
  fs: prefetch inode data in dcache lookup
  fs: improve scalability of pseudo filesystems
  fs: dcache per-inode inode alias locking
  fs: dcache per-bucket dcache hash locking
  bit_spinlock: add required includes
  kernel: add bl_list
  xfs: provide simple rcu-walk ACL implementation
  btrfs: provide simple rcu-walk ACL implementation
  ext2,3,4: provide simple rcu-walk ACL implementation
  fs: provide simple rcu-walk generic_check_acl implementation
  fs: provide rcu-walk aware permission i_ops
  fs: rcu-walk aware d_revalidate method
  fs: cache optimise dentry and inode for rcu-walk
  fs: dcache reduce branches in lookup path
  fs: dcache remove d_mounted
  fs: fs_struct use seqlock
  fs: rcu-walk for path lookup
  ...

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c
index b690aa3..1b125c2 100644
--- a/drivers/usb/core/inode.c
+++ b/drivers/usb/core/inode.c
@@ -343,17 +343,19 @@ static int usbfs_empty (struct dentry *dentry)
 {
 	struct list_head *list;
 
-	spin_lock(&dcache_lock);
-
+	spin_lock(&dentry->d_lock);
 	list_for_each(list, &dentry->d_subdirs) {
 		struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
+
+		spin_lock_nested(&de->d_lock, DENTRY_D_LOCK_NESTED);
 		if (usbfs_positive(de)) {
-			spin_unlock(&dcache_lock);
+			spin_unlock(&de->d_lock);
+			spin_unlock(&dentry->d_lock);
 			return 0;
 		}
+		spin_unlock(&de->d_lock);
 	}
-
-	spin_unlock(&dcache_lock);
+	spin_unlock(&dentry->d_lock);
 	return 1;
 }