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From: Leon Romanovsky <leon@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@kernel.dk>,
	Sagi Grimberg <sagi@grimberg.me>,
	Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>,
	linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] nvme-pci: add missing condition check for existence of mapped data
Date: Tue, 30 Jul 2024 20:39:20 +0300	[thread overview]
Message-ID: <20240730173920.GD4209@unreal> (raw)
In-Reply-To: <20240730172111.GA32320@lst.de>

On Tue, Jul 30, 2024 at 07:21:11PM +0200, Christoph Hellwig wrote:
> On Tue, Jul 30, 2024 at 11:09:04AM -0600, Keith Busch wrote:
> > > +	if (blk_rq_nr_phys_segments(req))
> > > +		nvme_unmap_data(dev, req);
> > 
> > This is already applied, but it is kind of strange. We get here only if
> > metadata mapping fails. Is there actually a command that has metadata
> > without data?
> 
> Well, passthrough can always set metadata to map without data even
> if there is no NVMe defined command that works that way, so we should
> handle the error.
> 
> But I suspect this is due to Leon's dma-mapping work, and it probably
> points to a bug in that :)

Yeah, something like that. I had a bug in my code and saw this
asymmetry while reviewed all paths which lead to nvme_unmap_data().

Thanks

      parent reply	other threads:[~2024-07-30 17:39 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20240724180451epcas5p3cffc89fcc59156ca49078a60851f1e29@epcas5p3.samsung.com>
2024-07-24 10:31 ` [PATCH] nvme-pci: add missing condition check for existence of mapped data Leon Romanovsky
2024-07-24 17:57   ` Nitesh Shetty
2024-07-25 14:06   ` Christoph Hellwig
2024-07-25 14:29   ` Keith Busch
2024-07-30 17:09   ` Keith Busch
2024-07-30 17:21     ` Christoph Hellwig
2024-07-30 17:33       ` Keith Busch
2024-07-30 17:39       ` Leon Romanovsky [this message]

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