VFS: Add forget_all_cached_acls()

This is required for cluster filesystems which want to use
cached ACLs so that they can invalidate the cache when
required.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>

include/linux/posix_acl.h

@@ -147,6 +147,20 @@ static inline void forget_cached_acl(struct inode *inode, int type)
 	if (old != ACL_NOT_CACHED)
 		posix_acl_release(old);
 }
+
+static inline void forget_all_cached_acls(struct inode *inode)
+{
+	struct posix_acl *old_access, *old_default;
+	spin_lock(&inode->i_lock);
+	old_access = inode->i_acl;
+	old_default = inode->i_default_acl;
+	inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
+	spin_unlock(&inode->i_lock);
+	if (old_access != ACL_NOT_CACHED)
+		posix_acl_release(old_access);
+	if (old_default != ACL_NOT_CACHED)
+		posix_acl_release(old_default);
+}
 #endif
 
 static inline void cache_no_acl(struct inode *inode)