From: Benjamin Coddington <ben.coddington@hammerspace.com>
To: Sean Chang <seanwascoding@gmail.com>
Cc: Benjamin Coddington <ben.coddington@hammerspace.com>,
Jeff Layton <jlayton@kernel.org>,
trondmy@kernel.org, anna@kernel.org, linux-nfs@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/2] NFS: Fix RCU dereference of cl_xprt in nfs_compare_super_address
Date: Tue, 21 Apr 2026 07:00:46 -0400 [thread overview]
Message-ID: <00DC338C-976F-43A7-B38F-3C9D8DD2D082@hammerspace.com> (raw)
In-Reply-To: <20260419163138.26963-3-seanwascoding@gmail.com>
On 19 Apr 2026, at 12:31, Sean Chang wrote:
> The cl_xprt pointer in struct rpc_clnt is marked as __rcu. Accessing
> it directly in nfs_compare_super_address() is unsafe and triggers
> Sparse warnings.
>
> Fix this by using rcu_dereference() within an RCU read-side critical
> section to retrieve the transport pointer. This addresses the sparse
> warning and ensures atomic access to the pointer, as the transport
> can be updated via transport switching even while the superblock
> remains active under sb_lock.
>
> Fixes: 7e3fcf61abde ("nfs: don't share mounts between network namespaces")
> Signed-off-by: Sean Chang <seanwascoding@gmail.com>
Reviewed-by: Benjamin Coddington <bcodding@hammerspace.com>
Ben
prev parent reply other threads:[~2026-04-21 11:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-19 16:31 [PATCH v3 0/2] NFS: fix RCU and tracing pointer safety Sean Chang
2026-04-19 16:31 ` [PATCH v3 1/2] NFS: remove redundant __private attribute from nfs_page_class Sean Chang
2026-04-19 16:31 ` [PATCH v3 2/2] NFS: Fix RCU dereference of cl_xprt in nfs_compare_super_address Sean Chang
2026-04-21 11:00 ` Benjamin Coddington [this message]
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