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

[Ritesh Raj Sarraf]

Hello Scott,

On Monday 15 June 2015 07:17 PM, Scott Moser wrote:
> 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).

That file is supposed to be created only if the user set friendly names,
which would mean create a multipath.conf file.
For setups without friendly names, this should be fine.

>
> 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.

Very true. I guess the best resolution to this problem would be to
document it in the README.Debian file.



>
> 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
>


-- 
Ritesh Raj Sarraf | http://people.debian.org/~rrs
Debian - The Universal Operating System


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