From: Christoph Hellwig <hch@lst.de>
To: Breno Leitao <leitao@debian.org>
Cc: Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@kernel.dk>,
Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
kernel-team@meta.com
Subject: Re: [PATCH] nvme/host: Fix RCU list traversal to use SRCU primitive
Date: Mon, 4 Nov 2024 14:16:52 +0100 [thread overview]
Message-ID: <20241104131652.GB14373@lst.de> (raw)
In-Reply-To: <20241104-nvme_rcu-v1-1-ecb19f5c95fa@debian.org>
On Mon, Nov 04, 2024 at 04:24:40AM -0800, Breno Leitao wrote:
> The code currently uses list_for_each_entry_rcu() while holding an SRCU
> lock, triggering false positive warnings with CONFIG_PROVE_RCU=y
> enabled:
>
> drivers/nvme/host/core.c:3770 RCU-list traversed in non-reader section!!
>
> While the list is properly protected by SRCU lock, the code uses the wrong
> list traversal primitive. Replace list_for_each_entry_rcu() with
> list_for_each_entry_srcu() to correctly indicate SRCU-based protection
> and eliminate the false warning.
I didn't even know there was such as thing as list_for_each_entry_srcu,
but apparently it's been there for a while. Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
> Something similar will need to be done for multipath. I will get it done
> once I get some feedback about this patch first.
Thanks!
next prev parent reply other threads:[~2024-11-04 13:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-04 12:24 [PATCH] nvme/host: Fix RCU list traversal to use SRCU primitive Breno Leitao
2024-11-04 13:16 ` Christoph Hellwig [this message]
2024-11-04 21:26 ` Keith Busch
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