From: Al Viro <viro@zeniv.linux.org.uk>
To: NeilBrown <neil@brown.name>
Cc: Kees Cook <kees@kernel.org>,
Joel Granados <joel.granados@kernel.org>,
linux-fsdevel@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] proc_sysctl: remove RCU annotations for accessing ->sysctl
Date: Fri, 13 Jun 2025 04:04:17 +0100 [thread overview]
Message-ID: <20250613030417.GG1647736@ZenIV> (raw)
In-Reply-To: <174978315268.608730.1330012617868311392@noble.neil.brown.name>
On Fri, Jun 13, 2025 at 12:52:32PM +1000, NeilBrown wrote:
>
> The ->sysctl field of a procfs inode is only set when the inode is
> created, and when it is being evicted. In both these cases there cannot
> be concurrent accesses and so using RCU_INIT_POINTER() and
> rcu_dereference() is misleading.
Wait a minute. Why can't there be concurrent accesses? ->evict_inode()
is *before* RCU delay, not after it.
Sure, you can't hit it from d_alloc_parallel(), but you very much can
in normal dcache lookup...
prev parent reply other threads:[~2025-06-13 3:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-13 2:52 [PATCH] proc_sysctl: remove RCU annotations for accessing ->sysctl NeilBrown
2025-06-13 3:04 ` Al Viro [this message]
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