openat2 codepath

openat2-codepath.md

• openat2 (fs/open.c) - https://elixir.bootlin.com/linux/v6.0.19/source/fs/open.c#L1345
  • do_sys_openat2 - https://elixir.bootlin.com/linux/v6.0.19/source/fs/open.c#L1294
    • do_filp_open - https://elixir.bootlin.com/linux/v6.0.19/source/fs/namei.c#L3710
      • path_openat - https://elixir.bootlin.com/linux/v6.0.19/source/fs/namei.c#L3671
        • open_last_lookups - https://elixir.bootlin.com/linux/v6.0.19/source/fs/namei.c#L3429
          • lookup_open - https://elixir.bootlin.com/linux/v6.0.19/source/fs/namei.c#L3318
            • inode isn't cached
            • dir_inode->i_op->lookup [ext4_lookup] - https://elixir.bootlin.com/linux/v6.0.19/source/fs/ext4/namei.c#L1811
              • ext4_iget - https://elixir.bootlin.com/linux/v6.0.19/source/fs/ext4/inode.c#L4758
                • inode = iget_locked(sb, ino); // allocate inode
                • raw_inode = ext4_raw_inode(&iloc);
                • i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
                • i_uid_write(inode, i_uid) - https://elixir.bootlin.com/linux/v6.0.19/source/include/linux/fs.h#L1611
                  • inode->i_uid = make_kuid(i_user_ns(inode), uid); // use sb.userns to map to kernel_id