tags 494001 + patch
thanks
On Tue, May 12, 2009 at 05:43:28AM +1000, Kel Modderman wrote:
> > Does checkroot.sh need to change at all with respect to what it does to
> > /etc/mtab?
[patch]
I've attached a new patch against the current sources to implement
this. Note that it only handles migration in one direction, that
it, it will not switch /back/ from a symlink in the absence of
/proc/mounts. While this could be added, is this a situation we
really need to cater for?
There are no OS checks--this permits kfreebsd support and future
Hurd support. The logic is in the shell function mtab_migrate
to permit the clean addition of special casing for e.g. Hurd.
This patch, like /dev/shm → /run/shm and /etc/network/ifstate →
/run/network/ifstate, does not preserve symlinks to places other
than /proc/* (the assumption being that symlinks to other files
were hacks to permit read-only root but still being static files).
Such hacks are no longer needed.
Regards,
Roger
--
.''`. Roger Leigh
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>From 36e073fbd1cd02bbc4756c0d4eedda7cd05c745d Mon Sep 17 00:00:00 2001
From: Roger Leigh <rle...@debian.org>
Date: Sun, 23 Oct 2011 14:45:51 +0100
Subject: [PATCH 1/2] Migrate /etc/mtab to symlink to /proc/mounts when
possible
---
debian/src/initscripts/etc/init.d/checkroot.sh | 15 +++++++
debian/src/initscripts/etc/init.d/mtab.sh | 45 +-------------------
debian/src/initscripts/lib/init/mount-functions.sh | 24 ++++++++++
3 files changed, 41 insertions(+), 43 deletions(-)
diff --git a/debian/src/initscripts/etc/init.d/checkroot.sh b/debian/src/initscripts/etc/init.d/checkroot.sh
index 2ce59f8..beef8cf 100755
--- a/debian/src/initscripts/etc/init.d/checkroot.sh
+++ b/debian/src/initscripts/etc/init.d/checkroot.sh
@@ -286,6 +286,13 @@ but requested that the system be restarted."
mount -n -o remount,$rootopts,$rootmode /
fi
+ # If possible, migrate /etc/mtab to be a symlink to
+ # /proc/mounts. Note that not all systems e.g. Hurd currently
+ # support this.
+ if [ "$rootmode" != "ro" ]; then
+ mtab_migrate
+ fi
+
#
# We only create/modify /etc/mtab if the location where it is
# stored is writable. If /etc/mtab is a symlink into /proc/
@@ -295,11 +302,14 @@ but requested that the system be restarted."
MTAB_PATH="$(readlink -f /etc/mtab || :)"
case "$MTAB_PATH" in
/proc/*)
+ # Assume that /proc/ is not writable (do nothing)
;;
/*)
+ # Common case for file or symlink (initialise)
if touch "$MTAB_PATH" >/dev/null 2>&1
then
:> "$MTAB_PATH"
+ chmod 644 /etc/mtab
rm -f ${MTAB_PATH}~
INIT_MTAB_FILE=yes
fi
@@ -318,6 +328,11 @@ but requested that the system be restarted."
;;
esac
+ if selinux_enabled && [ -x /sbin/restorecon ] && [ -r /etc/mtab ]
+ then
+ restorecon /etc/mtab
+ fi
+
if [ "$INIT_MTAB_FILE" = yes ]
then
[ "$roottype" != none ] &&
diff --git a/debian/src/initscripts/etc/init.d/mtab.sh b/debian/src/initscripts/etc/init.d/mtab.sh
index 65ad2d2..0be7f96 100644
--- a/debian/src/initscripts/etc/init.d/mtab.sh
+++ b/debian/src/initscripts/etc/init.d/mtab.sh
@@ -30,49 +30,8 @@ KERNEL="$(uname -s)"
. /lib/init/mount-functions.sh
do_start () {
- # Needed to determine if root is being mounted read-only.
- read_fstab
-
- DO_MTAB=""
- MTAB_PATH="$(readlink -f /etc/mtab || :)"
- case "$MTAB_PATH" in
- /proc/*)
- # Assume that /proc/ is not writable
- ;;
- /*)
- # Only update mtab if it is known to be writable
- # Note that the touch program is in /usr/bin
- #if ! touch "$MTAB_PATH" >/dev/null 2>&1
- #then
- # return
- #fi
- ;;
- "")
- [ -L /etc/mtab ] && MTAB_PATH="$(readlink /etc/mtab)"
- if [ "$MTAB_PATH" ]
- then
- log_failure_msg "Cannot initialize ${MTAB_PATH}."
- else
- log_failure_msg "Cannot initialize /etc/mtab."
- fi
- ;;
- *)
- log_failure_msg "Illegal mtab location '${MTAB_PATH}'."
- ;;
- esac
-
- #
- # Initialize mtab file if necessary
- #
- if [ ! -f /etc/mtab ]
- then
- :> /etc/mtab
- chmod 644 /etc/mtab
- fi
- if selinux_enabled && [ -x /sbin/restorecon ] && [ -r /etc/mtab ]
- then
- restorecon /etc/mtab
- fi
+ # Note that mtab should have been previously initialised by
+ # checkroot.sh.
# Add entries for mounts created in early boot
# S01mountkernfs.sh
diff --git a/debian/src/initscripts/lib/init/mount-functions.sh b/debian/src/initscripts/lib/init/mount-functions.sh
index 3c97ed5..019b9de 100644
--- a/debian/src/initscripts/lib/init/mount-functions.sh
+++ b/debian/src/initscripts/lib/init/mount-functions.sh
@@ -336,6 +336,30 @@ run_migrate ()
}
#
+# Migrate /etc/mtab to a compatibility symlink
+#
+mtab_migrate ()
+{
+ # Don't symlink if /proc/mounts does not exist.
+ if [ ! -r "/proc/mounts" ]; then
+ return 1
+ fi
+
+ # Create symlink if not already present.
+ if [ -L "/etc/mtab" ] && [ "$(readlink "/etc/mtab")" = "/proc/mounts" ]; then
+ :
+ else
+ log_warning_msg "Creating compatibility symlink from /etc/mtab to /proc/mounts."
+
+ rm -f "/etc/mtab" || return 1
+ ln -fs "/proc/mounts" "/etc/mtab" || return 1
+ [ -x /sbin/restorecon ] && /sbin/restorecon "/etc/mtab"
+ fi
+
+ return 0
+}
+
+#
# For compatibility, create /var/run and /var/lock symlinks to /run
# and /run/lock, respectively.
#
--
1.7.7
>From 27bd8d918e68f8a1ef5d480613e16c92f3973c3d Mon Sep 17 00:00:00 2001
From: Roger Leigh <rle...@debian.org>
Date: Sun, 23 Oct 2011 15:15:51 +0100
Subject: [PATCH 2/2] Close #494001
---
debian/changelog | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/debian/changelog b/debian/changelog
index fee3db6..7b08ddf 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,8 +1,14 @@
sysvinit (2.88dsf-14) UNRELEASED; urgency=low
+ [ Kel Modderman ]
* Add support for s390x, thanks to Aurelien Jarno <aure...@debian.org>.
(Closes: #641107)
+ [ Roger Leigh ]
+ * Make /etc/mtab a symlink to /proc/mounts. (Closes: #494001)
+ Note that this is only done when the root filesystem is writable
+ and /proc/mount is readable.
+
-- Kel Modderman <k...@otaku42.de> Sun, 11 Sep 2011 09:39:40 +1000
sysvinit (2.88dsf-13.11) unstable; urgency=low
--
1.7.7
