[Pkg-sysvinit-devel] Bug#655582: initscripts: incorrect rootfs unmount logic causes dirty FS at every boot

[Michele Mazzucchi]

Package: initscripts
Version: 2.88dsf-13.1
Severity: important

Hello folks,

While building a system based on an "aufs" root, I noticed that all
partitions, at start up, always require fsck when the union is used,
even after clean shutdowns.

The /etc/rc0.d/K08umountfs node (really /etc/init.d/umountfs ) fails
to unmount them at shutdown. That script contains this logic to determine
which mounted entries not to unmount:

========================
do_stop () {
        exec 9<&0 </proc/mounts
        PROTECTED_MOUNTS="$(sed -n '0,/^\/[^ ]* \/ /p' /proc/mounts)"
========================

This protects all mounts "up to the / ". However, such sed pattern matches the
root filesystem as "is mounted on path <slash> AND the mount device starts
with <slash>". If the root filesystem is mounted from a node such as "aufs",
the root line does not match, and all mounts end up in PROTECTED_MOUNTS.

I suppose the additional "/" constraint is a hack used to prevent matching the
initial "rootfs /" entry. I would rewrite this as:

PROTECTED_MOUNTS="$(awk 'NR==1,$1 != "rootfs" && $2 == "/"' /proc/mounts)"

or, since awk dwells in /usr,

PROTECTED_MOUNTS="$(sed -n ':a;/^[^ ]* \/ /!{H;n;ba};{H;s/.*//;x;s/\n//;p}'
/proc/mounts)"

This unmounts all entries down to the "base" root which is not the kernel standard
"rootfs". If / is mounted multiple times, this unmounts all "stacked" entries as well.
In the "aufs" case I described above, this ensures the additional partitions are
cleanly unmounted.

Any comments?

cheers
michele


-- System Information:
Debian Release: 6.0.3
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: armel (armv5tel)

Kernel: Linux 2.6.32-5-kirkwood
Locale: LANG=en_US.UTF-8, LC_CTYPE=UTF-8 (charmap=locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash

Versions of packages initscripts depends on:
ii  coreutils               8.5-1            GNU core utilities
ii  debianutils             3.4              Miscellaneous utilities specific t
ii  libc6                   2.11.2-10        Embedded GNU C Library: Shared lib
ii  lsb-base                3.2-23.2squeeze1 Linux Standard Base 3.2 init scrip
ii  sysv-rc                 2.88dsf-13.1     System-V-like runlevel change mech
ii  sysvinit-utils          2.88dsf-13.1     System-V-like utilities

Versions of packages initscripts recommends:
ii  e2fsprogs               1.41.12-4stable1 ext2/ext3/ext4 file system utiliti
ii  psmisc                  22.11-1          utilities that use the proc file s

initscripts suggests no packages.

-- debconf information excluded


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