From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4868921CEB for ; Mon, 12 Jun 2023 16:32:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88CBAC433D2; Mon, 12 Jun 2023 16:32:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686587538; bh=PV5OW3UaWfWmaC3Hd9wjtEzKlQ9Rb16b7K8BlJN47QQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E+8mITw9pTk12tRvdksTbVB+55sgKuY5k8jelBY+flV6vPrMyDXlroQAqc6PC9jJy xfErlu4b6gikEXx4RUsWnar5wejmHSnFs4P+eoefjP5QwA4EPPHNPpFGTSuNYF0icV DYMyS0hdoOMCq2I0Gu3mwGER0nS7Zk05VKYUEk4g923q2dmHzQAxXc1Uo6OJ/outvD IhIXMyD5bEgmDlwiZh2kQ37xfkbVjSJGXmDNMQVIpgen5qSyP1PPOP/YcnxNo9j7TC fZnWyT692R4WMrbyxAjsEKDKwl7mjT+cD4t+3/MBcIU5qtY6r1EsDWqzFnf3gT5Fb/ cJGBttEK519Aw== Date: Mon, 12 Jun 2023 09:32:16 -0700 From: Eric Biggers To: Alexander Larsson Cc: miklos@szeredi.hu, linux-unionfs@vger.kernel.org, amir73il@gmail.com, tytso@mit.edu, fsverity@lists.linux.dev Subject: Re: [PATCH v3 2/4] ovl: Add framework for verity support Message-ID: <20230612163216.GA847@sol.localdomain> References: <03ac0ffd82bc1edc3a9baa68d1125f5e8cad93fd.1686565330.git.alexl@redhat.com> Precedence: bulk X-Mailing-List: fsverity@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <03ac0ffd82bc1edc3a9baa68d1125f5e8cad93fd.1686565330.git.alexl@redhat.com> On Mon, Jun 12, 2023 at 12:27:17PM +0200, Alexander Larsson wrote: > +fs-verity support > +---------------------- > + > +When metadata copy up is used for a file, then the xattr > +"trusted.overlay.verity" may be set on the metacopy file. This > +specifies the expected fs-verity digest of the lowerdata file. This > +may then be used to verify the content of the source file at the time > +the file is opened. During metacopy copy up overlayfs can also set > +this xattr. > + > +This is controlled by the "verity" mount option, which supports > +these values: > + > +- "off": > + The verity xattr is never used. This is the default if verity > + option is not specified. > +- "on": > + Whenever a metacopy files specifies an expected digest, the > + corresponding data file must match the specified digest. > + When generating a metacopy file the verity xattr will be set > + from the source file fs-verity digest (if it has one). > +- "require": > + Same as "on", but additionally all metacopy files must specify a > + verity xattr. This means metadata copy up will only be used if > + the data file has fs-verity enabled, otherwise a full copy-up is > + used. It looks like my request for improved documentation was not taken, which is unfortunate and makes this patchset difficult to review. - Eric