Function check_fs_node_setxattr_access 

pub fn check_fs_node_setxattr_access(
    current_task: &CurrentTask,
    fs_node: &FsNode,
    name: &FsStr,
    value: &FsStr,
    op: XattrOp,
) -> Result<(), Errno>

This is called by Starnix even for filesystems which support extended attributes, unlike Linux LSM. Partially corresponds to the inode_setxattr() LSM hook: It is equivalent to inode_setxattr() for non-security xattrs, while fs_node_setsecurity() is always called for security xattrs. See also fs_node_setsecurity().