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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> X-Mailing-List: linux-erofs@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Subscribe: , , List-Unsubscribe: Precedence: list 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