Bug 10236

Summary:	busybox umount doesn't support -c
Product:	Busybox	Reporter:	Neil MacLeod <busybox>
Component:	Standard Compliance	Assignee:	unassigned
Status:	NEW ---
Severity:	enhancement	CC:	busybox-cvs
Priority:	P5
Version:	1.27.x
Target Milestone:	---
Hardware:	All
OS:	Linux
Host:		Target:
Build:

Description Neil MacLeod 2017-08-18 21:10:21 UTC

systemd v234 now adds the "-c" argument when unmounting:

https://github.com/systemd/systemd/blob/v234/src/core/mount.c#L889

systemd v234 will exit with an error when unmounting a partition using busybox 1.27.x: https://forum.libreelec.tv/thread/9599-8-1-0-beta-systemd-unmounts-fail-due-to-c-parameter-not-existing/

From Ubuntu 16.04 "man umount":

-c, --no-canonicalize
   Do not canonicalize paths.  For more details about this option see the mount(8) man page.  Note that umount does not pass this option to the /sbin/umount.type helpers.

util-linux also supports -c.

At the very least busybox could just treat -c as a umount no-op?

Thanks.