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 EFB94606A31A for ; Fri, 23 Oct 2026 22:51:40 +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=fSK0ZWxs; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ZgVooS87 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=Muxf07sSgo53ViJk8EziLS9KAhS0946f8xd/EfFheFY=; b=fSK0ZWxsZVfUTgN9j7UdieJo0D Z7rXjzKcEI54U3ywsTqYa3sWMY//H6XU/m/+L/j9tHhvYo6B91isVW0u63yREq0RYgmdKkx6tDY0T iWcYZnfNwn9yc3aL2UhAKzkCi8mMDEtjAclSBq9yMKku1UAZGTxC7bEBSX8FnOfrZFOb93UYB0I0l 6jwH+ozF51iS1rOjgkXcHS3Khd6I5OCQ6MeQypTvcJ+2/FKrSlNgcR/SB1wW/yAZ5zoHK8FAhE5RL sNUCuMGcSu7AoNQW2yH6P6HqCgF9a+I0bPVsL4luTh+U3fps9dVUMfOmoFvYJEUSHsFePzBDedMx9 fQgM5JEA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xKO6u-0000000H4kg-2kuP; Fri, 23 Oct 2026 22:51:40 +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 1xKO6s-0000000H4hv-3Kwv for kexec@lists.infradead.org; Fri, 23 Oct 2026 22:51:38 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 3F4F660A87; Fri, 23 Oct 2026 22:51:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 228111F01825; Fri, 23 Oct 2026 22:51:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792795898; bh=Muxf07sSgo53ViJk8EziLS9KAhS0946f8xd/EfFheFY=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=ZgVooS879Z8K9qRb+4xZ7cbWx4UAIqxgkVcui9xM6iEEvSe0zTlMtwdHJj5NLObod O5FTV65dYX60NxNaQ9p/vmqdnCP6rR2zW+hi4l2qHKW9LyYELt0P0wQjfS3nqLd6oA X3uvj293lzLyO4v/NisO/GvFsk1IEgCaLsKuDiHpjmaYsRTNdmLFZdR6QRFAWzjlzY JFA5k6J2LVUjqsoELLj5IMQ9gu1UtPuL46qj4lm3DPTcMPVlnC5vOA2lb+CVbMKahU btkChKzdGjME0nsmooAKi+qZ11KOCOfOdR1d3qE2rUisIamI/E/D1O3Hc77c8FxA9M 9KlXsNKv+lDTA== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 07/10] mm/shmem_luo: Retrieve tmpfs files onto a tmpfs mount chosen by userspace 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: <20261022225035.377445-8-dmatlack@google.com> References: <20261022225035.377445-1-dmatlack@google.com> <20261022225035.377445-8-dmatlack@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 23 Oct 2026 22:51:36 +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=-11.2 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: > Retrieve files that were preserved from a tmpfs mount onto a tmpfs mount > chosen by userspace, instead of as memfds on the internal tmpfs mount. > Record which mount a file was on with a new SHMEM_LUO_FLAG_TMPFS flag in > struct shmem_luo_ser, based on the superblock of the file. shmem_luo > already accepts unlinked tmpfs files, such as files created with > O_TMPFILE, and a following commit also accepts linked ones. >=20 > The mount a tmpfs file was on doesn't exist in the new kernel, and > userspace may want to put the file elsewhere anyway. So add struct > liveupdate_shmem_retrieve_arg, which userspace passes as the retrieve > argument of LIVEUPDATE_SESSION_RETRIEVE_FD. It is modeled on open(): The > kernel creates a new file as if by openat(dirfd, ".", O_TMPFILE | flags, > mode), so the file gets the owner, permission checks and security labels > of any new file in that directory, and is charged to that mount. The > kernel then fills the file with the preserved contents, size, position > [ ... ] > Like the other failures before the folios are restored, problems with > the argument and with creating the file can be retried. >=20 > Assisted-by: LLM > Signed-off-by: David Matlack Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261022225035.3774= 45-1-dmatlack@google.com?part=3D7