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 B0EA939D6F6 for ; Mon, 31 Aug 2026 07:46:25 +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=1788162386; cv=none; b=aiArguPYBhllHK49csC5AtgVUzZ3LqJJ3WkqtkIJ0GgRhNklb7fEW0Jr6R8kesoX3z/9a+umfVb2MtCZMNvobtHKGVSR3HN0yw6GyC1BfSXmzG1JZn1J9WHOE4sC5XZe6J6nfHgvEArYJd9/DJLi8M9Gjl5rTnhAVa49LVNV/7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788162386; c=relaxed/simple; bh=aIaZgPsVBhLkD4VFDu19TSH7Egql2U/u0HunY/L61bw=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=FdsHlwfj29PZKQyL43+Iya8SzWwSOg66UFJz8WqRfu06+ZzRVDSeBPbTaoNZwQy/Y8EXHUBEi1xxYl1VYjteid2Lo/H0ZJ1ih0qmO0177ugyQyGtjanWn1uZbNOH10vdnn/CR3z6kw8IBbA+7dsEuxpPdOi0U6YpZ2io2ulsTeA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oLQry5P8; 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="oLQry5P8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C428E1F000E9; Mon, 31 Aug 2026 07:46:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788162385; bh=VsPmteMgnqcVdcLhtU+19faUBqt6fMPz0Emib+Jo0kw=; h=Date:Cc:Subject:To:References:From:In-Reply-To; b=oLQry5P8smWmfIAGXsHLVdtag7oTjwjxrlgyLqUKWYK4Z7+fWcFfy7M1BxBW/KTux JZFIpBNAmqwf66QJHCY0nV2coIl/eyEm7EK3voBc6QwcFFHmENbE7aj/AdqOjffWvr j1D5I0ygP2eq5qCwuhJ4QLGdeayj1Y7U/aaibkUhMYo4h3sUah1LhlN8uZIGgnt7dw QEl4dN8b5RyQ73MtoFHoTSxQB1/BRC+CQB2Q2/GHV2h4vLx/aFco2F+S4613rVjK3V iXBz7RG0ZgBx3qP+v+S6M57Glp/6Ugla5K+oV8ZwLDiQwDNUkGKhrsyYYdzpkG1QcZ A5V47NwLm60XA== Message-ID: <404d2f2b-c8b6-43de-a6e4-9e4989ae5d44@kernel.org> Date: Mon, 31 Aug 2026 15:46:21 +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 , Nanzhe Zhao , Juan Yescas , Dev Jain , linux-kernel@vger.kernel.org, David Hildenbrand , Bo Zhang , Kalesh Singh , Ryan Roberts , Pengfei Li Subject: Re: [PATCH 10/14] f2fs: handle partial truncate of large folio dirty subpages To: Nanzhe Zhao , linux-f2fs-devel@lists.sourceforge.net, Jaegeuk Kim References: <20260826082641.2007658-1-zhaonanzhe@xiaomi.com> <20260826082641.2007658-11-zhaonanzhe@xiaomi.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20260826082641.2007658-11-zhaonanzhe@xiaomi.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/26/26 16:26, Nanzhe Zhao wrote: > A large folio can be partial truncated and stays in folio mapping, we > need to clear the subrange dirty bits and uptodate bits that the partial > truncate covers. If this partial truncate happens to clear the last > subrange dirty bits, then cancel the whole folio dirty state. > > Also add a guard in f2fs_write_single_data_folio() so a large folio > subpage whose disk block was already truncated (NULL_ADDR) is skipped > > Signed-off-by: Nanzhe Zhao > --- > fs/f2fs/data.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 73 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 59b07b83b216..15774e8e8795 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -2693,6 +2693,34 @@ static void f2fs_ffs_mark_subrange_uptodate(struct folio *folio, size_t offset, > folio_mark_uptodate(folio); > } > > +static void ffs_clear_subrange_uptodate(struct folio *folio, > + size_t offset, size_t len) > +{ > + struct f2fs_folio_state *ffs; > + unsigned int nr_subpages, start, end; > + unsigned long flags; > + > + f2fs_bug_on(F2FS_F_SB(folio), offset + len > folio_size(folio)); > + > + if (!f2fs_folio_has_ffs(folio)) { > + if (folio_test_uptodate(folio)) > + folio_clear_uptodate(folio); > + return; > + } > + > + ffs = (struct f2fs_folio_state *)folio->private; > + nr_subpages = folio_nr_pages(folio); > + start = offset >> PAGE_SHIFT; > + end = (offset + len + PAGE_SIZE - 1) >> PAGE_SHIFT; > + end = min(end, nr_subpages); > + > + spin_lock_irqsave(&ffs->state_lock, flags); > + bitmap_clear(ffs->state, start, end - start); > + spin_unlock_irqrestore(&ffs->state_lock, flags); > + if (folio_test_uptodate(folio)) > + folio_clear_uptodate(folio); > +} > + > bool f2fs_ffs_test_blk_dirty(const struct folio *folio, pgoff_t index) > { > struct f2fs_folio_state *ffs; > @@ -3599,6 +3627,21 @@ static int f2fs_write_single_data_folio(struct folio *folio, int *submitted, > > fio.old_blkaddr = dn.data_blkaddr; > > + /* This page is already truncated */ > + if (fio.old_blkaddr == NULL_ADDR) { > + ffs_clear_subrange_uptodate(folio, > + i << PAGE_SHIFT, PAGE_SIZE); > + folio_clear_f2fs_gcing(folio); > + f2fs_put_dnode(&dn); > + if (f2fs_folio_has_ffs(folio)) { > + struct f2fs_folio_state *ffs = > + (struct f2fs_folio_state *)folio->private; > + > + atomic_dec(&ffs->write_pages_pending); > + } > + continue; > + } > + > got_it: > if (__is_valid_data_blkaddr(fio.old_blkaddr) && > !f2fs_is_valid_blkaddr(sbi, fio.old_blkaddr, > @@ -5075,8 +5118,37 @@ void f2fs_invalidate_folio(struct folio *folio, size_t offset, size_t length) > struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > > if (inode->i_ino >= F2FS_ROOT_INO(sbi) && > - (offset || length != folio_size(folio))) > + (offset || length != folio_size(folio))) { > + size_t clear_start = ALIGN(offset, PAGE_SIZE); round_up(offset, PAGE_SIZE) will be more efficient? > + size_t clear_end = round_down(offset + length, PAGE_SIZE); > + size_t clear_length = 0; > + > + /* > + * If the truncated range falls within a single subpage, no > + * subpage state needs to be cleared. > + */ > + if (clear_start < clear_end && f2fs_folio_has_ffs(folio)) { How about cleaning up to avoid long line w/ if (clear_start >= clear_end || !f2fs_folio_has_ffs(folio)) return; > + bool dirty; > + > + clear_length = clear_end - clear_start; > + dirty = f2fs_ffs_clear_subrange_dirty(folio, > + clear_start, clear_length); > + ffs_clear_subrange_uptodate(folio, clear_start, > + clear_length); > + > + /* > + * If the truncated subrange happens to clear the > + * remaining dirty bitmap of the whole folio, cancel > + * the folio-level dirty state. > + */ > + if (!dirty && folio_test_dirty(folio)) { > + inode_dec_dirty_pages(inode); > + f2fs_remove_dirty_inode(inode); > + folio_cancel_dirty(folio); > + } > + } > return; > + } > > if (folio_test_dirty(folio)) { > if (inode->i_ino == F2FS_META_INO(sbi)) {