[PATCH 2/4] xfs: introduce CONFIG_XFS_WARN

[Ben Myers]

On Tue, Apr 30, 2013 at 09:39:34PM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner at redhat.com>
> 
> Running a CONFIG_XFS_DEBUG kernel in production environments is not
> the best idea as it introduces significant overhead, can change
> the behaviour of algorithms (such as allocation) to improve test
> coverage, and (most importantly) panic the machine on non-fatal
> errors.
> 
> There are many cases where all we want to do is run a
> kernel with more bounds checking enabled, such as is provided by the
> ASSERT() statements throughout the code, but without all the
> potential overhead and drawbacks.
> 
> This patch converts all the ASSERT statements to evaluate as
> WARN_ON(1) statements and hence if they fail dump a warning and a
> stack trace to the log. This has minimal overhead and does not
> change any algorithms, and will allow us to find strange "out of
> bounds" problems more easily on production machines.
> 
> There are a few places where assert statements contain debug only
> code. These are converted to be debug-or-warn only code so that we
> still get all the assert checks in the code.
> 
> Signed-off-by: Dave Chinner <dchinner at redhat.com>

Applied.