linux-kernel - Re: [PATCH 3/3] xfs: work around sparse context tracking in xfs_qm_dquot

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20251118060032.GD22733@lst.de>
Date: Tue, 18 Nov 2025 07:00:32 +0100
From: Christoph Hellwig <hch@....de>
To: "Darrick J. Wong" <djwong@...nel.org>
Cc: Christoph Hellwig <hch@....de>, Carlos Maiolino <cem@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Luc Van Oostenryck <luc.vanoostenryck@...il.com>,
	Chris Li <sparse@...isli.org>, linux-sparse@...r.kernel.org,
	linux-xfs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] xfs: work around sparse context tracking in
 xfs_qm_dquot_isolate

On Fri, Nov 14, 2025 at 09:06:23AM -0800, Darrick J. Wong wrote:
> On Fri, Nov 14, 2025 at 06:52:25AM +0100, Christoph Hellwig wrote:
> > sparse gets confused by the goto after spin_trylock:
> > 
> > fs/xfs/xfs_qm.c:486:33: warning: context imbalance in 'xfs_qm_dquot_isolate' - different lock contexts for basic block
> > 
> > work around this by duplicating the trivial amount of code after the
> > label.
> 
> Might want to leave a code comment about shutting up sparse so that
> someone doesn't revert this change to optimize LOC.  That said ...
> what is the differing lock context?  Does sparse not understand the
> spin_trylock?

So in case that my cover letter wasn't clear enough (or not widely read
:)), I'm somewhat doubtful about wanting to actually merge this upstream.
It just feels wrong to me.  But it was the list thing to need a clean
compile, so I wanted to demonstrate it.