Re: [rdiff-backup-users] Creates a mirror with chmod 644 directories

[dean gaudet]

On Thu, 8 Jun 2006, Douglas Bollinger wrote:

> Using: rdiff-backup 1.0.4 on source and dest.
> 
> Source: Runs as root
> Dest: a non-root, regular user
> 
> Source: Make a directory with 644 perms:
> 
> address@hidden ~/.gnome2 $ ll
> total 188K
> drw-r--r-- 2 doug users 4.0K 2006-05-27 08:23 accels
> 
> It will backup without any problems at dest...
> 
> address@hidden ~/backup_sets/ghidorah/home/doug/.gnome2 $ ls -l
> total 188
> drw-r--r-- 2 backup users  4096 May 27 08:23 accels
> 
> But now the backup user at dest can't enter that directory anymore...
> 
> address@hidden ~/backup_sets/ghidorah/home/doug/.gnome2 $ cd accels
> -su: cd: accels: Permission denied
>
> I believe at some point having a directory that a normal user at the dest
> can't enter will be a problem.  At least, when rdiff-backup-data became
> corrupt and I erased it, rdiff-backup couldn't create a new data directory
> until I put sane 730 perms on all the backup directories at source and dest.

rdiff-backup, for better or worse, does a chmod on the directory while 
it's operating.  it has no problems with the directory... i even tried 
removing rdiff-backup-data subdir and doing a new backup and it worked as 
well.

i'm using 1.0.4 + recent cvs but i don't think that will make a 
difference...


> Granted, this was using the older version, but I'm leary of nuking the new
> rdiff-backup-data directory as it takes hours to create and I would like to
> keep the backup revisions for now.  Besides, once the 644 perms directories
> are created, I don't see how a normal user on dest can get around entering the
> directory.  Or am I wrong on this?

you can just chmod it... rdiff-backup won't care even if you do a restore 
-- it'll use its own metadata representation to get the correct perms.


> Of course, the solution for me was to have sane perms for directories at the
> source, but this seems like a bug if you wish to backup as a normal user at
> dest.

there've been issues similar to this in the past -- ben generally chooses 
to have the destination be as faithful a mirror as possible given the 
constraints of the destination filesystem/user/OS/etc.

i said "for better or worse" above because rdiff-backup emphatically 
cannot operate with a read-only repository even when doing a restore... 
precisely because of tweaks like this required to read the mirror... 
although it shouldn't be too hard to add a feature where it sets the 
mirror perms to something explicit (i.e. r/w by backup user, and r/o for 
restore group)... i'd review such a patch if someone wrote it.

if you're somehow getting rdiff-backup tracebacks when i'm not getting 
them then we should look further... otherwise i think this is a feature 
request rather than a bug report...

-dean