From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3DCB62DAFAC for ; Tue, 2 Dec 2025 18:00:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764698437; cv=none; b=fUcmOoxgKREkxtJ/4u/2mc+iFx6BSJeyo1yxrbP95DoL7Cx+bY4pIv8ri7H5SENwOycSgNvZOQiM11SRf9q3xi14iIgAmtx2YYl4dpwPMHoW+JipBfT9A9yOtTVZt7/ouIImMwM0xuJakkU0QIqoxVdc0dsRYySQVGAWoIGTZvk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764698437; c=relaxed/simple; bh=h9f6fioitMCYIV/3E/k6YkyvuiuiX7bgdpTo0UL04XY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JP0iawmnXb0KcwhsoncAXxQc/+7bO8mrLzi2VYFSEiYMUXn3VPAZslZC2UDqJlHqPBJA0M7AWEgkdJ1gng9rDS2bCeZL7gRb+MQqOLIGomL+RRBIUOAa1KIoM51SL1YR3oLqhN2ICzo2Qs5GOAWpMVJU92b/K0oWO+hmK2ibCbw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KpYQXF4r; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KpYQXF4r" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E5B0C4CEF1; Tue, 2 Dec 2025 18:00:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764698436; bh=h9f6fioitMCYIV/3E/k6YkyvuiuiX7bgdpTo0UL04XY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KpYQXF4rLKLqJizsHvSK6PjAxthl5cF6HmCvuagwDSleEc3EUWOVfFXRef5If88XA ktbf9j7u/mZPW2MlMpPAMHE8A00BLWOhx+UdeQgFtGEtxXiTQBNPUBsWmEaRotcge1 YYiyExz1ahiw3l4zg6KAPnp52b8m5fcSYsBJcQuIUel5+ic8ITiZkm2UpKZwWayj/G hLQcKN7zayp4MMHdxue3I2kh9ljK+6OwDdmqw5rr51/5ch+GaW7nUk9tYUu10YLk02 7c0u4pfE6H5KPxZSuUsq6M0N4fzId2njUuXjrCI/KOdzf5yynqF/AaXlgebUnRD8a5 w8qwi8s/fFj1Q== Date: Tue, 2 Dec 2025 18:00:34 +0000 From: Jaegeuk Kim To: Xiaole He Cc: linux-f2fs-devel@lists.sourceforge.net, chao@kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org Subject: Re: [PATCH v2] f2fs: fix has_curseg_enough_space to check all data segments for dentry blocks Message-ID: References: <20251111060557.337514-1-hexiaole1994@126.com> <20251111061051.337547-1-hexiaole1994@126.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=us-ascii Content-Disposition: inline In-Reply-To: <20251111061051.337547-1-hexiaole1994@126.com> I need to drop this patch, since this breaks xfstests such as f2fs/005. Please revisit the issue. On 11/11, Xiaole He wrote: > When active_logs == 6, dentry blocks can be allocated to HOT, WARM, or > COLD segments based on various conditions in __get_segment_type_6(): > - age extent cache (if enabled) > - FI_HOT_DATA flag (set when dirty_pages <= min_hot_blocks) > - rw_hint (defaults to WARM via f2fs_rw_hint_to_seg_type) > - file_is_hot(), FI_NEED_IPU, f2fs_is_cow_file(), etc. > > However, has_curseg_enough_space() only checked CURSEG_HOT_DATA segment > for dentry blocks, which could lead to incorrect space calculation when > dentry blocks are actually allocated to WARM or COLD segments. > > Reproducer: > Note: This reproducer requires adding a tracepoint to observe segment > type. Add the following tracepoint to include/trace/events/f2fs.h: > > TRACE_EVENT(f2fs_allocate_data_block, > TP_PROTO(struct f2fs_sb_info *sbi, struct inode *inode, > enum log_type type, block_t blkaddr), > > TP_ARGS(sbi, inode, type, blkaddr), > > TP_STRUCT__entry( > __field(dev_t, dev) > __field(ino_t, ino) > __field(int, type) > __field(block_t, blkaddr) > __field(int, is_dir) > ), > > TP_fast_assign( > __entry->dev = sbi->sb->s_dev; > __entry->ino = inode ? inode->i_ino : 0; > __entry->type = type; > __entry->blkaddr = blkaddr; > __entry->is_dir = inode ? S_ISDIR(inode->i_mode) : 0; > ), > > TP_printk("dev = (%d,%d), ino = %lu, %s, blkaddr = %u, is_dir = %d", > show_dev(__entry->dev), > (unsigned long)__entry->ino, > show_data_type(__entry->type), > __entry->blkaddr, > __entry->is_dir) > ); > > And add the tracepoint call in fs/f2fs/segment.c in > f2fs_allocate_data_block() function. Find the location after > locate_dirty_segment() calls and before IS_DATASEG() check: > > locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr)); > locate_dirty_segment(sbi, GET_SEGNO(sbi, *new_blkaddr)); > > trace_f2fs_allocate_data_block(sbi, folio ? folio->mapping->host : NULL, > type, *new_blkaddr); > > if (IS_DATASEG(curseg->seg_type)) > > 1. Mount F2FS with active_logs=6 and age extent cache disabled: > # mkfs.f2fs -f /dev/sdb1 > # mount -t f2fs -o active_logs=6 /dev/sdb1 /mnt/f2fs-test > > 2. Enable tracing and f2fs_allocate_data_block tracepoint: > # echo 1 > /sys/kernel/debug/tracing/events/f2fs/f2fs_allocate_data_block/enable > # echo 1 > /sys/kernel/debug/tracing/tracing_on > # echo > /sys/kernel/debug/tracing/trace > > 3. Create a directory and write enough files to trigger dirty_pages > > min_hot_blocks (default 16), which will clear FI_HOT_DATA flag: > # mkdir /mnt/f2fs-test/testdir > # cd /mnt/f2fs-test/testdir > # seq 1 8192 | xargs touch > # sync > > 4. Observe dentry block allocation: > # cat /sys/kernel/debug/tracing/trace > > The trace output shows dentry blocks (is_dir = 1) allocated to WARM > segment because FI_HOT_DATA is cleared when dirty_pages > > min_hot_blocks (default 16). However, has_curseg_enough_space() only > checked HOT_DATA segment space. > > Fix by merging the dentry block check into the main data/node block > check loop and checking data_blocks + dent_blocks for data segments, > since both regular data blocks and dentry blocks can be written to the > same segment. When active_logs == 6, dentry blocks can be allocated to > any of the three data segments (HOT, WARM, COLD), so all three segments > need to account for dentry blocks. When active_logs != 6, dentry blocks > are always allocated to HOT_DATA segment only, so only HOT_DATA segment > needs to account for dentry blocks, while WARM and COLD segments only > check data_blocks. > > Fixes: ef095d19e82f ("f2fs: write small sized IO to hot log") > Cc: stable@kernel.org > Signed-off-by: Xiaole He > --- > Changes in v2 (per Yongpeng's feedback): > - Merged dentry block check into the main loop to avoid duplication > - Check data_blocks + dent_blocks for data segments (both can write to same segment) > --- > fs/f2fs/segment.h | 24 ++++++++++++------------ > 1 file changed, 12 insertions(+), 12 deletions(-) > > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h > index 1ce2c8abaf48..acda720a54eb 100644 > --- a/fs/f2fs/segment.h > +++ b/fs/f2fs/segment.h > @@ -626,21 +626,21 @@ static inline bool has_curseg_enough_space(struct f2fs_sb_info *sbi, > > left_blocks = get_left_section_blocks(sbi, i, segno); > > - blocks = i <= CURSEG_COLD_DATA ? data_blocks : node_blocks; > + if (i <= CURSEG_COLD_DATA) { > + blocks = data_blocks; > + /* > + * With active_logs == 6, dentry blocks can be allocated to > + * any data segment. With active_logs != 6, dentry blocks > + * are always allocated to HOT_DATA segment. > + */ > + if ((F2FS_OPTION(sbi).active_logs == 6) || (i == CURSEG_HOT_DATA)) > + blocks += dent_blocks; > + } else { > + blocks = node_blocks; > + } > if (blocks > left_blocks) > return false; > } > - > - /* check current data section for dentry blocks. */ > - segno = CURSEG_I(sbi, CURSEG_HOT_DATA)->segno; > - > - if (unlikely(segno == NULL_SEGNO)) > - return false; > - > - left_blocks = get_left_section_blocks(sbi, CURSEG_HOT_DATA, segno); > - > - if (dent_blocks > left_blocks) > - return false; > return true; > } > > -- > 2.43.0