Re: [Dump-users] restore -C EA (SELinux) problem

[Stelian P. <st...@po...>]

Le dimanche 23 avril 2006 =E0 22:18 -0400, Tony Nelson a =E9crit :
> At 2:20 PM -0400 4/23/06, Tony Nelson wrote:
> >I'm trying to learn how to use dump and restore (to/from DVD+/-R), and=
 I've
> >gotten it working to the point where the file data seems to be OK but =
the
> >SELinux Extended Attributes are not.  I used the commands (as root, wi=
th my
> >/ being LogVol02):
> >
> >    # mount -r /dev/VolGroup00/LogVol00 /mnt/lv00
> >    # dump -0 -L xxx -B 4590208 -f /tmp/dumpdvd /dev/VolGroup00/LogVol=
00
> >        [cdrecord used once per tape, from another terminal]
> >        # cdrecord -v -sao dev=3Ddvd -data /tmp/dumpdvd
> >    # restore -C -f /dev/dvd
> >
> >OK, some of that is superstition, but it works except for one of these
> >messages for each file, and no other errors (according to grep -v):
> >
> >    ./path/to/file: EA foo_x:object_r:bar_y value changed
>  ...
>=20
> OK, now I understand that these errors are due to a change in SELinux i=
n
> Fedora Core 5, where the 4th component (MLS) of the Security Context ha=
s
> been enabled.  When dump did the backup of the volume made under FC3, i=
t
> only dumped the 3 components that were in current use.

dump should backup *all* the EA which are set on the original inode. The
syscall which is used to retrieve the EA value doesn't know anything
about a 3 or 4 component value. It just retrieves the full value in a
buffer.

So I don't believe this is the cause, or at least not directly.

Before going further, let's just verify exactly what got changed. You
can retrieve the value of EA's using the getfattr command, like in:
	getfattr -d -m . /tmp/foo

(-d is for dumping all the EA, -m is the pattern search for the EAs,
here we want to dump all the EAs).

Try restoring your backup (not just verifying it), and run getfattr on
both the original and the extracted file. What is the result ?

Stelian.
--=20
Stelian Pop <st...@po...>