From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 99A002BE639 for ; Mon, 3 Aug 2026 23:41:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785800464; cv=none; b=lqWXLqE8DKStUe+UHgvtGcvTk/OCGjgQREDme2NdDGMtXXIsWfzijKIWxjHal7DCFo2ORAgX/6ma7ZYBCiuKKPzgWxbktN11+eeWffm7EbKz6ZXhrN4itEk3xaDmo+2M2ydybFdLTDU+Cl38WBi24bRuxJA0pkqoKe4ryGlNqbA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785800464; c=relaxed/simple; bh=gOiKK4TQnjuvHfvq6c7Cll6VZUKkJoEn7ru0Um1HfdU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=pif3xQOvyzI5bKrOy0zeurwRK8oRZ9M9qV7eVc2IgyHx7oMzy2ZWJWJyrb+dymHyFQtEtakssknrBso6vn9j8dbawavqenVxL1UoE2auI5Iyw4lajT+4SOCCYBJSloHrDWQuV2uSMUIfzLN6j8woBywWxnx19VLCAaJHzKZ+6tM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=M0BJuQs9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="M0BJuQs9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 536C21F000E9; Mon, 3 Aug 2026 23:40:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785800463; bh=q4ebMADhzsqGZo4g2q++EvXNBy8Vyr9f7ox5xCdjmho=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=M0BJuQs9xua3UyQqpC0j/HzH7OM14N+1DH/hAcRO2svjCN/3bZujd0RW2lU8qu0gF ms2psthVQ+Nn0B1T4dQrABCA+ZDBBasfUnRp/v5Ge2rO3aOrRBt44JK6kxceO1smfC +NENk9pw7T8+tnz/l1hYduFQgbEGkdavPuUyokC1mw/5s2qQGMvHBI8BNY7u9dCnCn FTya97HCJcY9vSR2Ruzi/PBnCmFr+tfKc7uGUpg+GF6CztprtvmAxO/pgbOWouZ9tp 9pZWn6ovDywvRZ3mb2zgd2ZZKbujQRR6deEJmd8zMmKZZPLSZSnghcWfhIKIn9CHEC LmUilB2cQBumQ== Date: Tue, 4 Aug 2026 07:40:53 +0800 From: Gao Xiang To: Zi Yan Cc: David Hildenbrand , "Matthew Wilcox (Oracle)" , Andrew Morton , Muchun Song , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Gregory Price , Ying Huang , Alistair Popple , Johannes Weiner , Qi Zheng , Shakeel Butt , Kairui Song , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Gao Xiang , Chao Yu , Yue Hu , Jeffle Xu , Sandeep Dhavale , Hongbo Li , Chunhai Guo , linux-erofs@lists.ozlabs.org Subject: Re: [PATCH RFC 08/14] fs/erofs: use folio_attach/detach_private() instead of direct assignment Message-ID: Mail-Followup-To: Zi Yan , David Hildenbrand , "Matthew Wilcox (Oracle)" , Andrew Morton , Muchun Song , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Gregory Price , Ying Huang , Alistair Popple , Johannes Weiner , Qi Zheng , Shakeel Butt , Kairui Song , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Gao Xiang , Chao Yu , Yue Hu , Jeffle Xu , Sandeep Dhavale , Hongbo Li , Chunhai Guo , linux-erofs@lists.ozlabs.org References: <20260731-remove-pg_private-v1-0-142c97ba3562@nvidia.com> <20260731-remove-pg_private-v1-8-142c97ba3562@nvidia.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260731-remove-pg_private-v1-8-142c97ba3562@nvidia.com> Hi Zi, On Fri, Jul 31, 2026 at 10:13:31PM -0400, Zi Yan wrote: > erofs_onelinefolio_init/split/end() use folio->private without setting > PG_private or increase folio refcount and it works. But after PG_private is > replaced by checking folio->private in a future commit, it can break > folio_expected_ref_count(), since the folio has private data without > elevated refcount. Change it now. > > It prepares for a future commit that removes PG_private. > > No funtional change intended. > > Assisted-by: Claude:claude-opus-4-8 > Assisted-by: Codex:gpt-5 > Signed-off-by: Zi Yan > To: Gao Xiang > To: Chao Yu > Cc: Yue Hu > Cc: Jeffle Xu > Cc: Sandeep Dhavale > Cc: Hongbo Li > Cc: Chunhai Guo > Cc: linux-erofs@lists.ozlabs.org > Cc: linux-kernel@vger.kernel.org It looks fine as long as PG_private flag will be removed in the follow-up patches: Reviewed-by: Gao Xiang Thanks, Gao Xiang