From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7DDD5606A31B for ; Wed, 4 Nov 2026 01:03:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=chlQpFwi; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=SieJqreB DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Date: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Cc:To:Subject: From:Message-ID:MIME-Version:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=4axXO3nL7G5bgijsfeANN8KYpkb6wMVtpEHlvk23Fcc=; b=chlQpFwi7l6EjOj0vbSNb5HQu3 1QynFt6t2rTAjy/tf8XAZvWlZyv03RNKimnvrIJ4HNEfkvNsgmAb42xI14BD79xNKcM8oDVDvW6II t7O6Mcp7AJOMOx4/CaqeoMh2A4koTXEpeU2AiNQKTn7qr6D684Wm9qgz85zNrLvAEwxTb3Y/QuLcs eMEmshS8L1zVKV188EVdfhtVEJ5KRy2YoBf0duhWxOORFg/q3JlZjRLnRuAEEvAKhXeJXlGu8WhnA +IPWANGaeVC3687gBvgxW3Kf51hnR2TeAvHILnhVY06r/4HeL2HViZO2ih8Nyod1dlgife17pC48R X2zJHG5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOPPc-000000042Tv-0Sgt; Wed, 04 Nov 2026 01:03:36 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xOPPa-000000042Ql-1die for kexec@lists.infradead.org; Wed, 04 Nov 2026 01:03:34 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 6588D60D85; Wed, 4 Nov 2026 01:03:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3ED401F000C1; Wed, 4 Nov 2026 01:03:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793754213; bh=4axXO3nL7G5bgijsfeANN8KYpkb6wMVtpEHlvk23Fcc=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=SieJqreB9CvP6QrZes4bq2SUXxisTj7TQfJdTpET9m/wQP5Q25KVKN8oefzmB3R3O FLIMzLz5+g67iDAeuHqX5zUD0byPqcJXNGfrsyaHUq9yVpcERADEo/gqKbCaU/V369 OwsBiYvs/sABqTNFQNJaG7TiyGKDCy1/qFGDnWrCcnC39t1zv2ZpiSxmPYS2D42cp8 IY3DpTmYal25XhQUgmVLfOZBnm0QfBNrkBAiRBMguBLBPVHIfk5338HalAZqFEuLCB u5bRa/JpQraZXpB9huOKdw2ZML2yip2jFjwcPEYFXXcnA9WPSAJVWCwx9RkgF1vIBN HNmFKrnLqLiog== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 08/10] mm/shmem_luo: Allow preserving tmpfs files that are still linked To: "David Matlack" , kexec@lists.infradead.org Cc: "Alexander Graf" , "Andrew Morton" , "Baolin Wang" , "Christian Brauner" , "David Hildenbrand" , "Hugh Dickins" , "Jonathan Corbet" , "Liam R. Howlett" , "Lorenzo Stoakes" , "Michal Hocko" , "Mike Rapoport" , "Pasha Tatashin" , "Pratyush Yadav" , "Randy Dunlap" , "Samiullah Khawaja" , "Shuah Khan" , "Suren Baghdasaryan" , "Vlastimil Babka" In-Reply-To: <20261103010216.3447716-9-dmatlack@google.com> References: <20261103010216.3447716-1-dmatlack@google.com> <20261103010216.3447716-9-dmatlack@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Wed, 04 Nov 2026 01:03:31 +0000 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "kexec" X-Spam-Status: No, score=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: > Allow preserving tmpfs files that are still linked. To preserve any > file, require permission to write to it and the file to be opened for > reading, and reject append-only files. >=20 > shmem_luo already accepts any shmem file without links, which includes > unlinked tmpfs files and files created with O_TMPFILE. Accepting linked > files means that userspace doesn't have to unlink files to preserve them > and can keep using them by path until the live update. >=20 > The path of the file isn't preserved. Like other files from tmpfs > mounts, a linked file is retrieved onto a tmpfs mount chosen by > userspace, which can then link it at the path it wants. >=20 > While a file is preserved, its size is frozen, so truncating it, > fallocate() and writes past its end fail with -EPERM. For a linked file, > [ ... ] > and for immutable files. >=20 > Document the frozen size and the permission requirements. >=20 > Signed-off-by: David Matlack Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261103010216.3447= 716-1-dmatlack@google.com?part=3D8