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 E9C6F3D967A for ; Wed, 9 Sep 2026 12:49:03 +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=1788958145; cv=none; b=PHLjbTRpuOR0ZPEXPnbQsGopPUvYYHw5k0X7xxLmvAYw/mox6dzYuCKBSegMhDfQqQGllMcG+dh0r3z/AddfkGjJb1PWBWu+bGfhG3lalLDpI5TftX9DszW0DQteCpZBu//chmRfZubfkkb7l06c+PwZ/rpvIcIobFYqvEi3fpo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788958145; c=relaxed/simple; bh=mzbcbjNcDnG7b1cMtDPYgMYpmGnleVU0pOD4fqhwAGE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=TG3r4c/J9BPnRuHdhMaNRtS9Qasgf5JaJ7VguBhZXXfowTyrXKMtQF2PX8iBBW6cTPLKyGGlfozIu1lr3yOmcV6Nmwz2XkGimvH/xr6eOFsy0doZMiZ7B20MUUeVb9xYcpCiaYwg5oD9LgUI2y7F7y5KGTnqs1VavJND1QKZeU4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ihpsg7zT; 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="ihpsg7zT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4AA2C1F00A3A; Wed, 9 Sep 2026 12:48:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788958143; bh=UeqpL36l3dlEIn9tPEeks2LG3oiHF6m9Q3Dm+vsjlY0=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ihpsg7zTtPBvi4+Os8u/1ED3tUrdC9elm20t4ZSzvBE9Bkx4e6b7G1ij7jXXses4N 2P5PWnIJ7hACkVVCEhrCtdfGv1nIq8YAOhgwcd+wgfkpib0lD1YcLByZ7rgA5qOppM 70MsqMVlNj4SfK5N/oZQ0WexzasmdicY9pWcO5mU31Q5E6d7+WH/OMoMbKv56uhqfr oShcWJy2lXM7w/ywj0JU41Hr8OoM4FxpTgq7iiZEWvb4eNwcvsUgLkBwQ27HL/INuX 2YSSUzuIbpCilwu21fzlQsl/3MYNNg7Lzv0aymQKMIqSljSl+P2XyhINnen+7hbBrJ TYkY3cgk4OjIg== Message-ID: <83a8743b-9cbb-42a5-9ff5-718297916a76@kernel.org> Date: Wed, 9 Sep 2026 14:48:54 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 06/14] f2fs: stop using PG_private To: Tal Zussman Cc: Zi Yan , "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, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net References: <20260907-remove-pg_private-v3-0-6ae22f9d9272@nvidia.com> <20260907-remove-pg_private-v3-6-6ae22f9d9272@nvidia.com> <178889163877.1334491.3646957026033534678.b4-reply@b4> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <178889163877.1334491.3646957026033534678.b4-reply@b4> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/8/26 20:20, Tal Zussman wrote: > On 2026-09-08 17:47 +0200, David Hildenbrand (Arm) wrote: >> On 9/8/26 04:56, Zi Yan wrote: >>> f2fs sets its PAGE_PRIVATE_* flags in page->private and checking >>> page->private != NULL is equivalent to checking PG_private. Change >>> PagePrivate() to page_private(). Meanwhile, in set_page_private_##name(), >>> page->private is first set to 0/NULL before an PAGE_PRIVATE_* flag is set, >>> but it can cause confusion when PG_private is removed and >>> page->private != NULL is used instead. Change it to initialize >>> page->private to PAGE_PRIVATE_NOT_POINTER instead and retain the original >>> semantics. >>> >>> It prepares for a future commit that removes PG_private. >>> >>> No functional change intended. >>> >>> Assisted-by: Claude:claude-opus-4-8 >>> Assisted-by: Codex:gpt-5 >>> To: Jaegeuk Kim >>> To: Chao Yu >>> Cc: linux-f2fs-devel@lists.sourceforge.net >>> Cc: linux-kernel@vger.kernel.org >>> Acked-by: Usama Arif >>> Acked-by: Chao Yu >>> Signed-off-by: Zi Yan >>> --- >>> fs/f2fs/f2fs.h | 8 ++++---- >>> 1 file changed, 4 insertions(+), 4 deletions(-) >>> >>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h >>> index 9940a6cecf1a2..2f7ab5888b078 100644 >>> --- a/fs/f2fs/f2fs.h >>> +++ b/fs/f2fs/f2fs.h >>> @@ -2691,7 +2691,7 @@ static inline bool folio_test_f2fs_##name(const struct folio *folio) \ >>> } \ >>> static inline bool page_private_##name(struct page *page) \ >>> { \ >>> - return PagePrivate(page) && \ >>> + return page_private(page) && \ >>> test_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page)) && \ >>> test_bit(PAGE_PRIVATE_##flagname, &page_private(page)); \ >>> } >>> @@ -2710,9 +2710,9 @@ static inline void folio_set_f2fs_##name(struct folio *folio) \ >>> } \ >>> static inline void set_page_private_##name(struct page *page) \ >>> { \ >>> - if (!PagePrivate(page)) \ >>> - attach_page_private(page, (void *)0); \ >>> - set_bit(PAGE_PRIVATE_NOT_POINTER, &page_private(page)); \ >>> + if (!page_private(page)) \ >>> + attach_page_private(page, \ >>> + (void *)BIT(PAGE_PRIVATE_NOT_POINTER)); \ >>> set_bit(PAGE_PRIVATE_##flagname, &page_private(page)); \ >>> } >> >> Very weird interface. Why do we even need the page-based interface still? >> >> $ git grep -E "(set|clear)_page_private" >> compress.c: clear_page_private_gcing(cc->rpages[i]); >> compress.c: set_page_private_gcing(cc->rpages[i]); >> compress.c: clear_page_private_gcing(cic->rpages[i]); >> f2fs.h:static inline void set_page_private_##name(struct page *page) \ >> f2fs.h:static inline void clear_page_private_##name(struct page *page) \ >> >> Seeing code like: >> >> clear_page_private_gcing(cc->rpages[i]); >> if (folio_test_writeback(page_folio(cc->rpages[i]))) >> end_page_writeback(cc->rpages[i]); >> >> Makes me wonder whether we can just use the folio helper instead? >> >> In f2fs_iget(), we enable large folios only when !f2fs_compressed_file(inode). >> >> So naive me would assume that we can just get rid of the >> set_page_private_/clear_page_private_ stuff entirely. >> > > I have a WIP series of ~30 patches converting much of the remaining page > users in f2fs (including the below) to folios. Still have to do some > testing and clean it up, but hoping to send it out in the next couple of > weeks (in the hopes of eliminating some more folio_compat.c functions by > next cycle...) Indeed best to wait a bit before flooding -mm even more, it's rather a lot at this point. In the context of this series, it would be great if you could review whether the diff I proposed would get the job done, thanks! -- Cheers, David