[pacman-dev] /etc/fstab rewritten by pacman!

[Roman Kyrylych]

2007/4/11, Dan McGee <dpmcgee at gmail.com>:
> > I wonder if this is biting us:
> > http://www.archlinux.org/pipermail/pacman-dev/2006-December/000838.html
> >
>
> Most certainly.
>
> > Roman, before you update, it would be interesting to get the three
> > different md5sums and see if this is the case. I'm just super
> > surprised that this never happened to me in all of my pacman updates.
>

Ok.

> I was also very surprised, but you explained it clearly below :)
>
> > If this is it, then these should be the steps to reproduce (note that
> > these reports are starting at step 5, the other stuff happened in the
> > past):
> > 1. Install a package that had a NoUpgrade line.
> > 2. Edit a backup file.
> > 3. Upgrade the package, causing the local md5sum to be written to the
> > DB (instead of the original md5sum from the new package).
> > 4. Do NOT edit the file again, and remove the NoUpgrade line from pacman.conf.
> > 5. Upgrade the package, causing the 'original' and 'old' md5sum to be
> > identical, which allows pacman to write an upgraded file over your
> > custom config.
>
> That's indeed when either 3 or 4 are missing that we avoid the bug.
> Once the config files have been edited, the package need to be upgraded at
> least once for the wrong checksums to be stored.
> So if NoUpgrade lines are removed before the damage is done, the bug
> doesn't happen.
>
> > Possible fixes:
> > 1. Put NoUpgrade lines back in. This is hacky/ugly IMO.
> > 2. Back up all config files that are to be overwritten as .pacold
> > files, even if they are supposedly legal candidates for overwriting.
> > This will cause some clutter on systems, however, but will ensure no
> > configurations are lost (although they would be moved).
>
> Like I said the on the forums :
> http://bbs.archlinux.org/viewtopic.php?pid=242384#p242384
> the original plan was apparently to not remove NoUpgrade in the first place,
> and wait long enough so that it's safe to remove them.
> It could take a while though, before the last user updates the packages
> with NoUpgrade files using pacman 3, so that all checksums are corrected.
>
> Maybe the few packages containing NoUpgrade files should be forced
> to be reinstalled, after pacman 3 is installed. I'm not sure that's
> 100% bullet proof though. Maybe checking all checksums in the db would
> be safer.
>
> I've my part of responsibility in this problem, because I'm the one who
> started complaining about NoUpgrade, because it actually caused clutters,
> and it made it harder to keep all config files up to date.
> So 2. would cause even more clutters, which is quite contradictory,
> but well, if it's the only way..
> I'm glad of pacman behavior once the transition is made, I already noticed
> the transition caused problems back then. But unfortunately, no one
> found a correct solution to it yet.
>
> > Thoughts? Am I right on this? I wasn't deep enough in pacman yet when
> > this issue came up.
>
> You look perfectly right to me (not that it means anything), but what
> disturbs be me highly is the behavior Roman describes.
> He claims he already did an upgrade of filesystem without NoUpgrade lines,
> so that should have put the correct checksums in the database.
> How could the bug be reproduced after that?
>

Here are more details I've got when recovered my server:

1) parts of pacman.conf:
. . .
[12/19/06 17:59] starting full system upgrade
[12/19/06 17:59] warning: extracting /etc/fstab as /etc/fstab.pacnew
[12/19/06 17:59] warning: extracting /etc/group as /etc/group.pacnew
[12/19/06 17:59] warning: extracting /etc/hosts as /etc/hosts.pacnew
[12/19/06 17:59] warning: extracting /etc/passwd as /etc/passwd.pacnew
[12/19/06 17:59] warning: extracting /etc/shadow as /etc/shadow.pacnew
[12/19/06 17:59] warning: extracting /etc/ld.so.conf as /etc/ld.so.conf.pacnew
[12/19/06 17:59] warning: extracting /etc/resolv.conf as /etc/resolv.conf.pacnew
[12/19/06 17:59] upgraded filesystem (0.7.2-5 -> 0.8-1)
. . .
[2007-04-10 14:03] upgraded fbreader (0.8.1-1 -> 0.8.1c-2)
[2007-04-10 14:03] warning: /etc/ld.so.conf installed as /etc/ld.so.conf.pacnew
[2007-04-10 14:03] upgraded filesystem (0.8-1 -> 0.8-2)
. . .
First update was made by older pacman version, but I'm not sure if it
was pacman2 or one of pacman3 RCs.

2) timestamps of files:
/etc/fstab - Apr 10, 14:03 (ctime and mtime)
/etc/fstab.pacnew - Dec 19 17:59 (ctime) & Dec 17, 15:54 (mtime)
As you may see fstab.pacnew was created during 0.7.2-5 -> 0.8-1 move

3) hosts, resolv.conf, passwd and group were also rewritten :-(

-- 
Roman Kyrylych (Роман Кирилич)