From: Dave Chinner <david@fromorbit.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>, linux-xfs@vger.kernel.org
Subject: Re: [PATCH 1/2 V2] xfs: gut error handling in xfs_trans_unreserve_and_mod_sb()
Date: Thu, 21 May 2020 07:55:30 +1000 [thread overview]
Message-ID: <20200520215530.GZ2040@dread.disaster.area> (raw)
In-Reply-To: <20200520202702.GA17627@magnolia>
On Wed, May 20, 2020 at 01:27:02PM -0700, Darrick J. Wong wrote:
> On Wed, May 20, 2020 at 12:48:05AM -0700, Christoph Hellwig wrote:
> > On Wed, May 20, 2020 at 05:33:58PM +1000, Dave Chinner wrote:
> > > + /*
> > > + * Debug checks outside of the spinlock so they don't lock up the
> > > + * machine if they fail.
> > > + */
> > > + ASSERT(mp->m_sb.sb_frextents >= 0);
> > > + ASSERT(mp->m_sb.sb_dblocks >= 0);
> > > + ASSERT(mp->m_sb.sb_agcount >= 0);
> > > + ASSERT(mp->m_sb.sb_imax_pct >= 0);
> > > + ASSERT(mp->m_sb.sb_rextsize >= 0);
> > > + ASSERT(mp->m_sb.sb_rbmblocks >= 0);
> > > + ASSERT(mp->m_sb.sb_rblocks >= 0);
> > > + ASSERT(mp->m_sb.sb_rextents >= 0);
> > > + ASSERT(mp->m_sb.sb_rextslog >= 0);
>
> Except for imax_pct and rextslog, all of these are unsigned quantities,
> right? So the asserts will /never/ trigger?
In truth, I didn't look that far. I just assumed that because all
the xfs_sb_mod*() functions used signed math that they could all
underflow/overflow. IOWs, the checking for overflow/underflow was
completely wrong in the first place.
Should I just remove the ASSERT()s entirely?
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2020-05-20 21:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 21:48 [PATCH 0/2] xfs: fix unecessary percpu counter overhead Dave Chinner
2020-05-19 21:48 ` [PATCH 1/2] xfs: gut error handling in xfs_trans_unreserve_and_mod_sb() Dave Chinner
2020-05-20 6:53 ` Christoph Hellwig
2020-05-20 7:03 ` Dave Chinner
2020-05-20 7:33 ` [PATCH 1/2 V2] " Dave Chinner
2020-05-20 7:48 ` Christoph Hellwig
2020-05-20 20:27 ` Darrick J. Wong
2020-05-20 21:55 ` Dave Chinner [this message]
2020-05-20 22:28 ` Darrick J. Wong
2020-05-20 22:37 ` Dave Chinner
2020-05-19 21:48 ` [PATCH 2/2] xfs: reduce free inode accounting overhead Dave Chinner
2020-05-20 6:56 ` Christoph Hellwig
2020-05-20 20:43 ` Darrick J. Wong
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