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 54C7539E19C for ; Tue, 22 Sep 2026 03:09:40 +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=1790046581; cv=none; b=IUMODwIQZ/S/nQhoSDRNYnVAeEjiC3dWfcJVDyhCNKziiZQZDrH2hbvgymBJdkVmAPMFa/pIxZR+SJ/2R5vMP/Zk8jkh8JICdIkW1rPwT0v64bf0XsFhkerWvYJh+uyoJUAr5j1NTxjoDSBrLpispwcZhZ01bP2OmqkKmBzBwJc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790046581; c=relaxed/simple; bh=g+4UhE/miynh/nrL+ppRVYV8EK/P7dnl+OZxiQwvWKE=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=mw1TLHKC9DL2mC4l8k3uK1AwbiJ+sYHymZG0P6+wvZZ5n22oLCgtME8J5MFmXBTrrZeYLyT2+jlB2iomjiUvFTo/PcUFg3tLjdwTM/jXlxYP3YOC/P+oLPEcXbcr9OuR64dSISEnfZoj24qMA09Ow7v/Pn/cydcRLbB1WHwBZkE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iGH8lUKF; 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="iGH8lUKF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFEB11F000FF; Tue, 22 Sep 2026 03:09:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790046579; bh=CBrq0W4hwuHtFakDlzYoO5CFxEwhKTqvSW2yit9CFf4=; h=Date:Cc:Subject:To:References:From:In-Reply-To; b=iGH8lUKFZTsbN++vJ/QwgzV0AfW4e21HkwgcxJtIBtce0InGcNNKyQVmFb/Y488e2 sE2k/I6sXlnJ4pSqL6/AWnwzHg/pdkIxKMyaX/5Ccw919j8KpfKtXz7yUnjw10GC/l gZcuBAPGEW7S4SyL2n2HbnnrxP03XnMOS02PFImiTMo8sUDXLNFV+e65pOlaUMSS/u OlNxLb2Fa+rjqYCXbTD6Q6cK5VpxXwICBax0bzK9rR/DV5OHGTHvJy3dl8LhmFmDCb iR+aO663/okc1AjvfWfBa2ujn55i/d3brjCERAr0Kcw7EgdZvFEGSRiS6/pfjPMiI2 5OhybF6cmvJPw== Message-ID: <747d2cbe-01ce-4261-a699-e51ede593434@kernel.org> Date: Tue, 22 Sep 2026 11:09:36 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: chao@kernel.org, Barry Song , Juan Yescas , Dev Jain , linux-kernel@vger.kernel.org, David Hildenbrand , Bo Zhang , Kalesh Singh , Nanzhe Zhao , Pengfei Li , Ryan Roberts Subject: Re: [PATCH v2 14/14] f2fs: make compressed files compatible with large folio To: Nanzhe Zhao , linux-f2fs-devel@lists.sourceforge.net, Jaegeuk Kim References: <20260915041909.2903887-1-zhaonanzhe@xiaomi.com> <20260915042503.2912616-4-zhaonanzhe@xiaomi.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20260915042503.2912616-4-zhaonanzhe@xiaomi.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/15/26 12:25, Nanzhe Zhao wrote: > The compression flag is the hint indicates that the inode can be > compressed, when the inode is using large folio, we expected it keeps > using the large folio read/write paths and its data stays uncompressed > on disk until the inode is evicted and re-read > > Let f2fs_write_begin() skip the compression overwrite preparation for > such inodes and remove the compressed-file gate in > f2fs_read_data_large_folio() so the data is simply read/written as > regular blocks. > > For the same reason, reject F2FS_IOC_COMPRESS_FILE with -EOPNOTSUPP > once the inode mapping is switched to large folios. > > Signed-off-by: Nanzhe Zhao > --- > Documentation/filesystems/f2fs.rst | 10 ++++++++++ > fs/f2fs/compress.c | 2 ++ > fs/f2fs/data.c | 9 ++------- > fs/f2fs/file.c | 7 +++++++ > 4 files changed, 21 insertions(+), 7 deletions(-) > > diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst > index 771216f45207..b4f436ffd9ac 100644 > --- a/Documentation/filesystems/f2fs.rst > +++ b/Documentation/filesystems/f2fs.rst > @@ -941,6 +941,16 @@ Compression implementation > reserved via ioctl(F2FS_IOC_RESERVE_COMPRESS_BLOCKS) or the file size is > truncated to zero. > > +- Compression and large folios are not effective at the same time on a file: > + a compressed inode does not use large folios, while an inode which is > + using large folios keeps its data uncompressed on disk. If the compression > + flag is set on an inode that is already using large folios, the flag works > + as a hint until the inode is evicted: the inode keeps using the large folio > + read/write paths, f2fs_write_begin() skips the compression overwrite > + preparation, and ioctl(F2FS_IOC_COMPRESS_FILE) fails with -EOPNOTSUPP. > + Once the inode is evicted and read back, it uses order-0 folios again and > + compression is applied as usual. > + > Compress metadata layout:: > > [Dnode Structure] > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c > index b130e43b4566..fa0f8449a12c 100644 > --- a/fs/f2fs/compress.c > +++ b/fs/f2fs/compress.c > @@ -78,6 +78,8 @@ bool f2fs_is_compressed_page(struct folio *folio) > return false; > if (folio_test_f2fs_nonpointer(folio)) > return false; > + if (f2fs_folio_has_ffs(folio)) > + return false; > > f2fs_bug_on(F2FS_F_SB(folio), > *((u32 *)folio->private) != F2FS_COMPRESSED_PAGE_MAGIC); > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index c9dba8d0ad3d..f5421334ecf3 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -2941,12 +2941,6 @@ static int f2fs_read_data_large_folio(struct inode *inode, > int ret = 0; > bool folio_in_bio = false; > > - if (f2fs_compressed_file(inode)) { > - if (folio) > - folio_unlock(folio); > - return -EOPNOTSUPP; > - } > - > map.m_seg_type = NO_CHECK_TYPE; > > if (rac) > @@ -4828,7 +4822,8 @@ static int f2fs_write_begin(const struct kiocb *iocb, > } > > #ifdef CONFIG_F2FS_FS_COMPRESSION > - if (f2fs_compressed_file(inode)) { > + if (f2fs_compressed_file(inode) && > + !mapping_large_folio_support(inode->i_mapping)) { > int ret; > struct page *page; > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index db71cadefabd..c5cb0b0384b6 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -5002,6 +5002,13 @@ static int f2fs_ioc_compress_file(struct file *filp) > if (!(filp->f_mode & FMODE_WRITE)) > return -EBADF; > > + /* > + * The mapping is already using large folios, where the data is kept > + * uncompressed, so refuse to start compressing the file. > + */ > + if (mapping_large_folio_support(inode->i_mapping)) It needs to print log here to give notice. e.g "not support if large folio bit is set, drop inode cache to unset the flag and retry" ? Thanks, > + return -EOPNOTSUPP; > + > f2fs_balance_fs(sbi, true); > > ret = mnt_want_write_file(filp);