On Thu, Aug 31, 2023 at 07:31:55AM +0200, Christoph Hellwig wrote: > sb->s_fs_info can only be safely freed after generic_shutdown_super was > called and all access to the super_block has stopped. Similar to ramfs case; nothing in dentry/inode eviction codepaths is using anything in ->s_fs_info. And references in tty are holding an active ref to superblock in question, preventing ->kill_sb(), so nothing from the outside is going to play with e.g. devpts_{new,kill}_index() under us.