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 AC032606A31A for ; Fri, 30 Oct 2026 03:40:29 +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=tOaBbQf4; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=R0Mt206+ 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=LqAfEiYgEiTiORKa7c0pxw0fos1KinhMxbjU0AdSzd0=; b=tOaBbQf4A79vkfvtWpFSj0KZiZ 2f0ixlqFbMe/qCvGwkiulG5K+gBOrMK4pix2pSih7Zl0YkbjGPjkIxVUzLFxCx4jxHGJX9SHkQPUP mowlZIpZ3BXMjCrZQq3SA7oDl0+0UQ0TlLi2VpsvvW61Rr2q3v5m9ISnZ6gcvWCshNEL6nFjh/Ytr GhVHeMdc+W0tamkyo8Q8ubbpqmPbZ/MstEDl1AwYU6lF/wS2TsXOMepwiNRkOk3+Eczv2MBwmmDjX 7Br3YKQdVmjN2AD8iYILX9AC58u6ewaS+iBcIXUYHNt7W3HaDjoDE2ZFqdM6XpjH1hyEP1M1+k+vY ZZkAP4qg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdTh-0000000Ajm7-1hOg; Fri, 30 Oct 2026 03:40:29 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdTf-0000000AjlO-2NJ2 for kexec@lists.infradead.org; Fri, 30 Oct 2026 03:40:27 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 51072436C4; Fri, 30 Oct 2026 03:40:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AB85A1F0093A; Fri, 30 Oct 2026 03:40:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793331627; bh=LqAfEiYgEiTiORKa7c0pxw0fos1KinhMxbjU0AdSzd0=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=R0Mt206+gIuegbQeP5By6JaeJ+LSLSMdTmb6t4CHZnx8LTQYnJjkR4qrdlCVjSM81 T++3ZosJz5ABEmnJUH3j9fDxVw8idGp7etM/Ixce48N/qNae4rP2M5vwRxFWEGUWk7 /hhfEjTLxDwKOTicmr/mtFZ2gtqMVP88pjzgfmnCFoioUVDhCCk3ZqvuWfvHlMPqk9 iXAWm4X9h8QkYVJb6lwOAQGuEXz+QcSwRoKJtT4Snp6HRn7Aay6KVFTpmTPIou+r6K 7mwBYi51UQcvCplY/wVn19+6Z2UC50NZJgmJ3aWZnlBy+8Qkcv5C1QpAclC6XhLrSD owdewHh3aik/g== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 05/47] mm/truncate: look again if a folio left the mapping To: =?utf-8?b?RGF2aWQgSGlsZGVuYnJhbmQgKEFybSk=?= , "Andrew Morton" , "Johannes Weiner" , "Michal Hocko" , "Qi Zheng" , "Shakeel Butt" , "Lorenzo Stoakes" , "Kairui Song" , "Barry Song" , "Axel Rasmussen" , "Yuanchu Xie" , "Wei Xu" , "Baoquan He" , "Baolin Wang" , "Liam R. Howlett" , "Vlastimil Babka" , "Mike Rapoport" , "Suren Baghdasaryan" , "Michal Hocko" , "Kees Cook" , "Peter Zijlstra" , "Jann Horn" , "Pedro Falcato" , "Hugh Dickins" , "Pasha Tatashin" , "Pratyush Yadav" , =?utf-8?b?TWF0dGhldyBXaWxjb3ggKE9yYWNsZSk=?= , "Jan Kara" , "Zi Yan" , "Lance Yang" , "Rik van Riel" , "Harry Yoo" , "Alistair Popple" , "Nico Pache" , "Ryan Roberts" , "Dev Jain" , "Usama Arif" , "Kiryl Shutsemau" , "Matthew Brost" , "John Hubbard" , "Peter Xu" , "Will Deacon" , "Aneesh Kumar K.V" , "Nick Piggin" , "Oscar Salvador" , "Minchan Kim" , "Muchun Song" , "Xu Xin" , "Chengming Zhou" , "Chris Li" , "Kemeng Shi" , "Nhat Pham" , "Youngjun Park" , "Gregory Price" , "Joshua Hahn" , "Rakie Kim" , "Ying Huang" , "Jason Gunthorpe" Cc: kexec@lists.infradead.org, "Josef Bacik" In-Reply-To: <20261029-fixes_core-v2-5-a64ce7f83abb@kernel.org> References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> <20261029-fixes_core-v2-5-a64ce7f83abb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Oct 2026 03:40:24 +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: > invalidate_inode_pages2_range() skips a folio which no longer belongs to > the mapping by the time it has got the folio lock, on the assumption > that somebody else has removed it from the page cache. But the folio may > have been replaced, and then there is a new folio with the same data at > that index. >=20 > For most cases, like folio migration, that is impossible. However, > collapse_file() only checks the refcount of the old folios, under the > i_pages lock, and relies on their folio locks from there on. That works f= or > users which repeat the lookup when they find folio->mapping changed. > The following scenario is, however, possible: >=20 > CPU0 pwrite(O_DIRECT) CPU1 collapse_file() > kiocb_invalidate_pages() > read the folio (old data), lock it > [ ... ] > Fixes: 1b6444331beb ("mm/khugepaged: enable clean pagecache folio collaps= e for writable files") > Cc: stable@vger.kernel.org > Reported-by: Josef Bacik > Reviewed-by: Rik van Riel > Signed-off-by: David Hildenbrand (Arm) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261029-fixes_core= -v2-0-a64ce7f83abb@kernel.org?part=3D5