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[85.226.165.230]) by smtp.gmail.com with ESMTPSA id a7-20020a2eb547000000b00290716d65dcsm651571ljn.136.2023.02.27.01.22.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Feb 2023 01:22:29 -0800 (PST) Message-ID: Subject: [LSF/MM/BFP TOPIC] Composefs vs erofs+overlay From: Alexander Larsson To: lsf-pc@lists.linux-foundation.org Cc: linux-fsdevel@vger.kernel.org Date: Mon, 27 Feb 2023 10:22:29 +0100 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.46.4 (3.46.4-1.fc37) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hello, Recently Giuseppe Scrivano and I have worked on[1] and proposed[2] the Composefs filesystem. It is an opportunistically sharing, validating image-based filesystem, targeting usecases like validated ostree rootfs:es, validated container images that share common files, as well as other image based usecases. During the discussions in the composefs proposal (as seen on LWN[3]) is has been proposed that (with some changes to overlayfs), similar behaviour can be achieved by combining the overlayfs "overlay.redirect" xattr with an read-only filesystem such as erofs. There are pros and cons to both these approaches, and the discussion about their respective value has sometimes been heated. We would like to have an in-person discussion at the summit, ideally also involving more of the filesystem development community, so that we can reach some consensus on what is the best apporach. Good participants would be at least: Alexander Larsson, Giuseppe Scrivano, Amir Goldstein, David Chinner, Gao Xiang, Miklos Szeredi, Jingbo Xu. [1] https://github.com/containers/composefs [2] https://lore.kernel.org/lkml/cover.1674227308.git.alexl@redhat.com/ [3] https://lwn.net/SubscriberLink/922851/45ed93154f336f73/ --=20 =3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D= -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D- =3D-=3D-=3D Alexander Larsson Red Hat, Inc=20 alexl@redhat.com alexander.larsson@gmail.com=20 He's a lounge-singing crooked cowboy on his last day in the job. She's a=20 psychotic nymphomaniac single mother prone to fits of savage,=20 blood-crazed rage. They fight crime!=20