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 A432A1C5F0E; Sat, 25 Jan 2025 09:22:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737796950; cv=none; b=VdAGv6WgpRIz0BYLL0W0jitrMuEPECZiLbPXF6emG0oc0BZGcNM8i42aTF+11lz6K1FHnhD6EIvtmo+pTXdYE4L3gg+YJRajI7FmsM4ctjS5xMtkQvp098i00SAsOo0pUoFea9hhrf2Lq6MNOb11bvU+4niUZoGjMv3dY7JQaQg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737796950; c=relaxed/simple; bh=cqUlUk2k5pKbHBcnRD85SRBc5qNEMVL84HeU65uNupg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ymmmsml7csN3U8paROmzcR5DrwJV8imZGUzMYqTXc7Hn0/8a2e/nUAqZBsrTZVDVvZMgKpFdzzK4zpqo4oKDWWVkJzgnh6OGPqbZe90odb3t9BqBUfsEtreQ8Oy1ulKaYkiNUeB+BbhihTkrFafLADqOjBpNCCtHDYUgIVlF1HY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nGRnD05v; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nGRnD05v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7622FC4CED6; Sat, 25 Jan 2025 09:22:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737796950; bh=cqUlUk2k5pKbHBcnRD85SRBc5qNEMVL84HeU65uNupg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=nGRnD05vmKrclL+x7ivQhXL3r/RRgSwiinN0LaeCaVh8PmEL/ZHYjcaEO1E1j6uiS Z4nGsHnt4FnkbamCXo3UfCe1lkQdxwSzG88l9UJXadXovBcwIGkUiD91enJy706BWv 6Ir/L1KEwPutdMf2Zslv2dC7MfHd98neMa6gMXpTBdDmL/jl/lpceXcaK7C767pMUB lC+UxQlLoNn/G60ZYu7SBTSD9W64A1hOow3jUpz8g/v2wweJRtlXJMDnpsF/5TVBdF hQ8KT5RRr6oTS3gNvkIevCrcCYnweO40H8kZJ0XQkqa1nFUoEYMGnh9f52sX/ybxa8 Mwef9jl0Obivw== Date: Sat, 25 Jan 2025 10:22:24 +0100 From: Christian Brauner To: Miklos Szeredi Cc: Miklos Szeredi , linux-fsdevel@vger.kernel.org, Jan Kara , Amir Goldstein , Karel Zak , Lennart Poettering , Ian Kent , Al Viro , linux-security-module@vger.kernel.org, Paul Moore Subject: Re: [PATCH v4 4/4] vfs: add notifications for mount attribute change Message-ID: <20250125-gesessen-gerutscht-0a0468193303@brauner> References: <20250123194108.1025273-1-mszeredi@redhat.com> <20250123194108.1025273-5-mszeredi@redhat.com> <20250124-abklopfen-orbit-287ed6b59c61@brauner> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Fri, Jan 24, 2025 at 04:49:28PM +0100, Miklos Szeredi wrote: > On Fri, 24 Jan 2025 at 16:38, Christian Brauner wrote: > > > > On Thu, Jan 23, 2025 at 08:41:07PM +0100, Miklos Szeredi wrote: > > > Notify when mount flags, propagation or idmap changes. > > > > > > Just like attach and detach, no details are given in the notification, only > > > the mount ID. > > > > > > Signed-off-by: Miklos Szeredi > > > --- > > > > I think this is a good next step but I would first go with the minimal > > functionality of notifying about mount topology changes for v6.15. > > I can totally relate to that. I added the fourth patch more as a > "let's see if this can also fit into the current framework". > > > Btw, if we notify in do_remount() on the mount that triggered > > superblock reconfiguration then we also need to trigger in > > vfs_cmd_reconfigure() aka fsconfig(FSCONFIG_CMD_RECONFIGURE) but the > > mount that was used to change superblock options is only available in > > fspick() currently. That would need to be handled. > > No, if we'd want to watch changes on super blocks, then we'd need to > iterate all the mounts of the superblock and notify each. Ah, I remember that old remount had unclear semantics where mount specific and superblock specific options are interleaved. So we would need to notify from do_remount() on mount specific changes. Right, then this change is correct and I agree about the superblock part.