* [PATCH 1/2] checkroot.sh: check for conflicting configurations
2013-08-26 6:43 [PATCH 0/2] initscripts: read-only rootfs fixes Qi.Chen
@ 2013-08-26 6:43 ` Qi.Chen
2013-08-26 6:43 ` [PATCH 2/2] read-only-rootfs-hook.sh: check before bind mounting /var/lib Qi.Chen
1 sibling, 0 replies; 3+ messages in thread
From: Qi.Chen @ 2013-08-26 6:43 UTC (permalink / raw)
To: openembedded-core
From: Chen Qi <Qi.Chen@windriver.com>
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]
Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
.../initscripts/initscripts-1.0/checkroot.sh | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/meta/recipes-core/initscripts/initscripts-1.0/checkroot.sh b/meta/recipes-core/initscripts/initscripts-1.0/checkroot.sh
index cf84cfa..dfee2af 100755
--- a/meta/recipes-core/initscripts/initscripts-1.0/checkroot.sh
+++ b/meta/recipes-core/initscripts/initscripts-1.0/checkroot.sh
@@ -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.
--
1.7.9.5
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 2/2] read-only-rootfs-hook.sh: check before bind mounting /var/lib
2013-08-26 6:43 [PATCH 0/2] initscripts: read-only rootfs fixes Qi.Chen
2013-08-26 6:43 ` [PATCH 1/2] checkroot.sh: check for conflicting configurations Qi.Chen
@ 2013-08-26 6:43 ` Qi.Chen
1 sibling, 0 replies; 3+ messages in thread
From: Qi.Chen @ 2013-08-26 6:43 UTC (permalink / raw)
To: openembedded-core
From: Chen Qi <Qi.Chen@windriver.com>
It's possible that /var/lib is on a separate writable partition. In such
situation, we should not bind mount /var/lib with tmpfs, becasue it's
already writable.
This patch fixes this problem by checking whether /var/lib is already
on a writable partition.
[YOCTO #4888]
Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
.../initscripts-1.0/read-only-rootfs-hook.sh | 33 +++++++++++++++++---
1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/meta/recipes-core/initscripts/initscripts-1.0/read-only-rootfs-hook.sh b/meta/recipes-core/initscripts/initscripts-1.0/read-only-rootfs-hook.sh
index 9cf0921..1a0328d 100644
--- a/meta/recipes-core/initscripts/initscripts-1.0/read-only-rootfs-hook.sh
+++ b/meta/recipes-core/initscripts/initscripts-1.0/read-only-rootfs-hook.sh
@@ -4,10 +4,35 @@
[ "$ROOTFS_READ_ONLY" = "no" ] && exit 0
+is_on_read_only_partition () {
+ DIRECTORY=$1
+ dir=`readlink -f $DIRECTORY`
+ while true; do
+ if [ ! -d "$dir" ]; then
+ echo "ERROR: $dir is not a directory"
+ exit 1
+ else
+ for flag in `awk -v dir=$dir '{ if ($2 == dir) { print "FOUND"; split($4,FLAGS,",") } }; \
+ END { for (f in FLAGS) print FLAGS[f] }' < /proc/mounts`; do
+ [ "$flag" = "FOUND" ] && partition="read-write"
+ [ "$flag" = "ro" ] && { partition="read-only"; break; }
+ done
+ if [ "$dir" = "/" -o -n "$partition" ]; then
+ break
+ else
+ dir=`dirname $dir`
+ fi
+ fi
+ done
+ [ "$partition" = "read-only" ] && echo "yes" || echo "no"
+}
+
if [ "$1" = "start" ] ; then
- grep -q "tmpfs /var/volatile" /proc/mounts || mount /var/volatile
- mkdir -p /var/volatile/lib
- cp -a /var/lib/* /var/volatile/lib
- mount --bind /var/volatile/lib /var/lib
+ if [ `is_on_read_only_partition /var/lib` = "yes" ]; then
+ grep -q "tmpfs /var/volatile" /proc/mounts || mount /var/volatile
+ mkdir -p /var/volatile/lib
+ cp -a /var/lib/* /var/volatile/lib
+ mount --bind /var/volatile/lib /var/lib
+ fi
fi
--
1.7.9.5
^ permalink raw reply related [flat|nested] 3+ messages in thread