Re: problem with cp-command

[Bob Proulx]

Peter Landgren wrote:
> In the test I did I got this problem, when I copied one file from a specific 
> user. The files are always copied, but the error occurs afterwords. If I use 
> konqueror or krusader to copy the same file, no errors.

Throughout the coreutils there has been a goal to detect and report
errors because silent data corruption due to an unreported error is
very bad.  Unfortunately not all projects have this as their goal.
This is not saying anything about konqueror or krusader because I
don't know but looking at it from here the fact that they did not
report an error does not mean that an error did not occur.  It may
have simply gone unreported.  Unfortunately this is simply a "no data"
point.

> I have a trace of one cp-command. See attachment.

The trace shows routines called attr_copy_file() and
attr_copy_check_permissions() and it appears to be the latter one that
is faiing.  I also see the string "setting attributes for %s" and
similar.  However none of those appear in coreutils.  They appear in
libattr.  This appears to be a patched version of coreutils for
SELinux, I guess?

> Some more tests. Its only with certain files from certain users I get
> this problem.

I am not familiar with SELinux but I believe you might be running
afoul of the access control lists.  In SELinux being root does not
mean that you have superuser access.  This would explain why you are
seeing errors even when running as root.  Root is meaningless for
SELinux.  This would also explain why you are seeing this problem only
on certain files or with certain users.

You might try turning off the SELinux policy layer and seeing if the
problem goes away at that time.

I would also try compiling a pristine copy of coreutils.  It is
possible that a bug was introduced by the 3rd party patches.

Bob