NFS_FSDATA_BLOCKED
if (dentry->d_fsdata == NFS_FSDATA_BLOCKED)
!= NFS_FSDATA_BLOCKED);
dentry->d_fsdata = NFS_FSDATA_BLOCKED;
WARN_ON(dentry->d_fsdata == NFS_FSDATA_BLOCKED)) {
WARN_ON(new_dentry->d_fsdata == NFS_FSDATA_BLOCKED))