Bug#466138: Is this LVM message actually useful?

[Alasdair G Kergon]

On Thu, Jul 09, 2009 at 12:19:21AM +0200, Andras Korn wrote:
> I'm still not sure I understand why this is such a big deal that it's
> unacceptable to just close them silently, 

Because the cause needs investigating in case it's a security hole (or other
program bug).  I believe every program has a responsibility to behave defensively
and report upon things it notices like that that are not normal.  When you're
satisfied there's not a security problem, and you don't want to change things
you can choose to add the suppression.  The original bug, by the way, was a
system-wide file descriptor leak (not on Debian), where most processes on the
system (irrespective of uid) gained unintended access to a root-only
File.

> Currently, --quiet doesn't work properly because LVM still prints messages
> that aren't critical errors.

Currently the role of --quiet is simply to disable any pre-configured
verbose or debug settings.  In other words it doesn't do very much useful.

But perhaps we could redefine it to suppress all the pointless "successfully"
messages inherited from LVM1.  In coding terms, to split the 'log_print' macro
into two macros, essential output (like the data from 'lvs') and non-essential
output, and have --quiet suppress the non-essential output.

> I wouldn't object to this bug being downgraded to wishlist and retitled to
> something like "Please fix --quiet so that it suppresseses the warning about
> FDs left open" (it's not my bug, so I won't mess with it myself). Add a
> wontfix tag if you think it's never going to be fixed.

As I indicated, that won't get changed without significant code restructuring,
which is unlikely to happen.
 
> However, I think at the very least the magic envvar should be documented for
> use in those cases where a stay FD is known to be present and LVM should be
> silent. This would help avoid kludges like lvsomething 2>&1 | fgrep -v ...

This bug provides documentation now for anyone searching...
 
Alasdair