checkroot.sh: check for conflicting configurations

In our current boot scripts, two ways are used to determine whether
the rootfs is read-only or not. One by checking the READ_ONLY_ROOTFS
value in /etc/default/rcS, the other by checking the /etc/fstab entry.

>From a normal Linux user's point of view, the way of checking the
/etc/fstab entry is preferred. However, as there are several boot scripts
that need to know whether rootfs is read-only or not, checking /etc/fstab
in each script brings too much overhead. Thus, these boot scripts
use the READ_ONLY_ROOTFS value in /etc/default/rcS.

In normal use cases, there would be no problem, as both /etc/default/rcS and
the /etc/fstab are modified at rootfs time. However, if the user changes
the mount option for rootfs in /etc/fstab to read-write, and he/she forgets
to change the value in /etc/default/rcS, there would be unexpected results.
For example, the udev-cache would still be disabled.

So at a minimal, a check for conflicting configurations between /etc/fstab
and /etc/default/rcS should be added in checkroot.sh so that there would be
reasonable warnings if users have configured the system in a non-consistent
way.

[YOCTO #4880]

(From OE-Core rev: 1565a0c5a3f245703e280ca90cf11d3f9374788a)

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Chen Qi 2013-08-26 14:43:54 +08:00 committed by Richard Purdie
parent 6f25176581
commit e6e44cf9c1
1 changed files with 10 additions and 0 deletions

View File

@ -54,6 +54,16 @@ do
done
exec 0>&9 9>&-
# Check for conflicting configurations
if [ "$rootmode" = "ro" -a "$ROOTFS_READ_ONLY" = "no" ] || \
[ "$rootmode" = "rw" -a "$ROOTFS_READ_ONLY" = "yes" ]; then
echo ""
echo "WARN: conflicting configurations in /etc/fstab and /etc/default/rcS"
echo " regarding the writability of rootfs. Please fix one of them."
echo ""
fi
#
# Activate the swap device(s) in /etc/fstab. This needs to be done
# before fsck, since fsck can be quite memory-hungry.