Bug#788841: multipath-tools-boot: inclusion of /etc/multipath/bindings in initramfs on install contains race condition

[Scott Moser]

Package: multipath-tools-boot
Version: 0.5.0-6+deb8u1
Severity: normal

Dear Maintainer,

Hi, in debugging an issue on Ubuntu under ubuntu bug 1462530
(http://pad.lv/1462530), we found that /etc/multipath/bindings needs to be
included in the initramfs.

The code in /usr/share/initramfs-tools/hooks/multipath will do that, but
only if the file exists.  The file is created in normal operation by
the multipath-tools service (/etc/init.d/multipath-tools).

However a normall install path of:
  apt-get install multipath-tools-boot

will cause multipath-tools service to be started in the background and will not
guarantee that the file exists before update-initramfs runs the hooks file to
collect it.

One possible way of addressing this would be to run 'multipath -r' to force its
creation.  That does possibly have side affects.

Generally speaking this is an unlikely race condition to hit, but I don't see
anything that guarantees it wont happen.


-- Package-specific info:
/etc/multipath.conf does not exist.


-- System Information:
Debian Release: 8.0
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.16.0-4-amd64 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages multipath-tools-boot depends on:
ii  debconf [debconf-2.0]  1.5.56
ii  initramfs-tools        0.120
ii  multipath-tools        0.5.0-6+deb8u1

multipath-tools-boot recommends no packages.

multipath-tools-boot suggests no packages.

-- debconf information excluded