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Date: Thu, 12 Sep 2024 09:46:13 +0200
From: Christoph Hellwig <hch@lst.de>
To: Keith Busch <kbusch@kernel.org>
Cc: Keith Busch <kbusch@meta.com>, axboe@kernel.dk, hch@lst.de,
	martin.petersen@oracle.com, linux-block@vger.kernel.org,
	linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org,
	sagi@grimberg.me
Subject: Re: [PATCHv4 10/10] blk-integrity: improved sg segment mapping
Message-ID: <20240912074613.GA8409@lst.de>
References: <20240911201240.3982856-1-kbusch@meta.com> <20240911201240.3982856-11-kbusch@meta.com> <ZuImbgYqqZzLZkho@kbusch-mbp.dhcp.thefacebook.com>
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On Wed, Sep 11, 2024 at 05:23:26PM -0600, Keith Busch wrote:
> On Wed, Sep 11, 2024 at 01:12:40PM -0700, Keith Busch wrote:
> > @@ -102,6 +103,12 @@ int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
> > +	 */
> > +	BUG_ON(segments > blk_rq_nr_phys_segments(rq));
> 
> Doh, this was mixed up with the copy from blk_rq_map_sg. It should say:
> 
> 	BUG_ON(segments > blk_rq_nr_integrity_segments(rq));
> 
> Question though, blk_rq_map_sg uses WARN and scsi used BUG for this
> check. But if the condition is true, a buffer overrun occured. So BUG,
> right?

That would be my preference, unless we manage to add a error return
condition.  Note that Linus seems to be on his weird anti-BUG crusade
again, though.