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Thu, 12 Feb 2026 05:24:58 -0800 (PST) From: Askar Safin To: viro@zeniv.linux.org.uk Cc: christian@brauner.io, hpa@zytor.com, jack@suse.cz, linux-fsdevel@vger.kernel.org, torvalds@linux-foundation.org, werner@almesberger.net Subject: Re: [RFC] pivot_root(2) races Date: Thu, 12 Feb 2026 16:23:45 +0300 Message-ID: <20260212132345.2571124-1-safinaskar@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260209003437.GF3183987@ZenIV> References: <20260209003437.GF3183987@ZenIV> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Al Viro : > The interesting part is whether > we want to deal with the possibility of errors at that point... You mean that finding topmost overmount of root of namespace may fail? Current code in mntns_install indeed can fail, at least theoretically: https://elixir.bootlin.com/linux/v6.19-rc5/source/fs/namespace.c#L6243 But I argue that this line is unnessesary and should be simply replaced with call to topmost_overmount (which, as well as I understand, cannot fail). As an additional benefit, this will allow us to remove LOOKUP_DOWN (this line is the only user of it). -- Askar Safin