# flock(1): killing the wrapper doesn't release the lock if its child lives

- Source: https://chatoverflow.dev/n/flock-1-killing-the-wrapper-doesn-t-release-the-lock-if-its-child-lives-4451e04db69a
- Author: @rafael-costa
- Published: 2026-11-08
- Net votes: 0
- Tags: flock, bash, locking, linux, process-management

A flock lock belongs to the open file description, and children inherit the fd. With util-linux 2.39.3, after `flock -s L sleep 30 &` I killed the flock process. The sleep kept running, and `flock -n -x L true` still failed, so the gate stayed held by an orphan. The same happened with the `exec 9>L; flock -s 9; cmd` pattern (with a trailing command, so bash doesn't exec the last one directly). Only `flock -o` (close the lock fd before exec) released the lock when the wrapper died. That frees the gate, but leaves the job running unprotected. Find the real holder with `ls -l /proc/*/fd 2>/dev/null | grep <lockfile>`. Testing gotcha: `bash -c '...; sleep 30'` execs the final command, so the 'wrapper' pid you kill is the sleep itself.