From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 29E0EC87FCA for ; Wed, 6 Aug 2025 06:11:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.sourceforge.net; s=beta; h=Content-Transfer-Encoding:Content-Type:Cc: Reply-To:From:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Subject:MIME-Version:Message-ID:Date:To:Sender: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=d02WC86eGxZdOhBw6lULP1+vP7MklAlyleFe778PVQk=; b=eA5Wp/wYMoREplKUxG3WSsqONr IyCXR2YJ03uenj8NbHLXeyx42g996O/dtg6h5bZitxDmkdF6UiyNzUjiX4HuhYq/shetRtBMFv4Ei Zvrt/YDZVoqOE22/33wm7taoNnAULuuOq7DZ3bKrnK2KBNHnGoumFF7vZ4ZyKiNtsttA=; Received: from [127.0.0.1] (helo=sfs-ml-3.v29.lw.sourceforge.com) by sfs-ml-3.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1ujXN2-0003jd-VX; Wed, 06 Aug 2025 06:11:28 +0000 Received: from [172.30.29.66] (helo=mx.sourceforge.net) by sfs-ml-3.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1ujXN2-0003jX-28 for linux-f2fs-devel@lists.sourceforge.net; Wed, 06 Aug 2025 06:11:28 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:Message-ID: Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=PMetFtcNlM56lAQPUpKLTZ1OYiXuj3UKSImWA5QbJ9s=; b=CFq3xbASanDiMrSP97KunOhYYq 0ZXY/Cu8wI7hpqZgjBM+3dQQygzFYDJrUbzc+q/HRwG0c1s/KfQ4jt5K6ZyQ3f4u2tUEYp8gzoPov cYXTFDwYTJ+kfyKW/rA52bqhmg8aGBpZJEk9DkHmdhIxb3PleAUACMZdnP6dLvVx/RuU=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:Cc:To:From :Sender:Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Id:List-Help:List-Unsubscribe:List-Subscribe:List-Post: List-Owner:List-Archive; bh=PMetFtcNlM56lAQPUpKLTZ1OYiXuj3UKSImWA5QbJ9s=; b=a uJvCVivSLUH6anG3t5OGHDB6X2KYT2Jt1T7N4w7lUmsqICImHQhGyvNX/9vVFEBgtISq2Z29JCLPZ GCLWjBLfUT0gaxC1vnGZVLeKQBVu33BUzyJMrxaP6/Out+W1rTM9gyyrCKqalJ2thTAn1Gr+R8pm6 buelAvtel+BQB1t0=; Received: from nyc.source.kernel.org ([147.75.193.91]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1ujXN1-0008Bu-Fn for linux-f2fs-devel@lists.sourceforge.net; Wed, 06 Aug 2025 06:11:28 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 7D855A568F1; Wed, 6 Aug 2025 06:11:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 032CEC4CEE7; Wed, 6 Aug 2025 06:11:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754460676; bh=UGRY8U7DyQIAExkPpgwhAztMw+LzvH6mrxdC0BG9rKw=; h=From:To:Cc:Subject:Date:From; b=o0vUjU7v2hvImqezzBHGghNRv1MPIxihHdzpDsW8LXDIuFV/lTIqfq0qz+VEKjGtV Daf+SwCKdMR4GgVa0M5d1tcnGHuYNBRxF8J4qMEfKypxu5Dvagbf1T3tfciQE5GrM1 3lQa92cwXicg5VwpL4K2KZbMOeWN9zfKkp4t4DoT9wBYk2fmU7p4RzpcB3j25/MJsO 8YfVe1Zm8UV3krf9lAjdOA/VFE4jnD8w1OpHUDxbD/wWFbC7cUsp3tqKRNuNchxT07 NqCNS7Pw7Rlre6YRPWpr8cvh6wLEybpMrVztz40zAOiT7MbRSzNIOY7iYqeuCu8ArZ AiKLAx8zMhrUw== To: jaegeuk@kernel.org Date: Wed, 6 Aug 2025 14:11:06 +0800 Message-ID: <20250806061106.3445717-1-chao@kernel.org> X-Mailer: git-send-email 2.50.1.565.gc32cd1483b-goog MIME-Version: 1.0 X-Headers-End: 1ujXN1-0008Bu-Fn Subject: [f2fs-dev] [PATCH v4 2/3] f2fs: fix to zero data after EOF for compressed file correctly X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Chao Yu via Linux-f2fs-devel Reply-To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net generic/091 may fail, then it bisects to the bad commit ba8dac350faf ("f2fs: fix to zero post-eof page"). What will cause generic/091 to fail is something like below Testcase #1: 1. write 16k as compressed blocks 2. truncate to 12k 3. truncate to 20k 4. verify data in range of [12k, 16k], however data is not zero as expected Script of Testcase #1 mkfs.f2fs -f -O extra_attr,compression /dev/vdb mount -t f2fs -o compress_extension=* /dev/vdb /mnt/f2fs dd if=/dev/zero of=/mnt/f2fs/file bs=12k count=1 dd if=/dev/random of=/mnt/f2fs/file bs=4k count=1 seek=3 conv=notrunc sync truncate -s $((12*1024)) /mnt/f2fs/file truncate -s $((20*1024)) /mnt/f2fs/file dd if=/mnt/f2fs/file of=/mnt/f2fs/data bs=4k count=1 skip=3 od /mnt/f2fs/data umount /mnt/f2fs Analisys: in step 2), we will redirty all data pages from #0 to #3 in compressed cluster, and zero page #3, in step 3), f2fs_setattr() will call f2fs_zero_post_eof_page() to drop all page cache post eof, includeing dirtied page #3, in step 4) when we read data from page #3, it will decompressed cluster and extra random data to page #3, finally, we hit the non-zeroed data post eof. However, the commit ba8dac350faf ("f2fs: fix to zero post-eof page") just let the issue be reproduced easily, w/o the commit, it can reproduce this bug w/ below Testcase #2: 1. write 16k as compressed blocks 2. truncate to 8k 3. truncate to 12k 4. truncate to 20k 5. verify data in range of [12k, 16k], however data is not zero as expected Script of Testcase #2 mkfs.f2fs -f -O extra_attr,compression /dev/vdb mount -t f2fs -o compress_extension=* /dev/vdb /mnt/f2fs dd if=/dev/zero of=/mnt/f2fs/file bs=12k count=1 dd if=/dev/random of=/mnt/f2fs/file bs=4k count=1 seek=3 conv=notrunc sync truncate -s $((8*1024)) /mnt/f2fs/file truncate -s $((12*1024)) /mnt/f2fs/file truncate -s $((20*1024)) /mnt/f2fs/file echo 3 > /proc/sys/vm/drop_caches dd if=/mnt/f2fs/file of=/mnt/f2fs/data bs=4k count=1 skip=3 od /mnt/f2fs/data umount /mnt/f2fs Anlysis: in step 2), we will redirty all data pages from #0 to #3 in compressed cluster, and zero page #2 and #3, in step 3), we will truncate page #3 in page cache, in step 4), expand file size, in step 5), hit random data post eof w/ the same reason in Testcase #1. Root Cause: In f2fs_truncate_partial_cluster(), after we truncate partial data block on compressed cluster, all pages in cluster including the one post eof will be dirtied, after another tuncation, dirty page post eof will be dropped, however on-disk compressed cluster is still valid, it may include non-zero data post eof, result in exposing previous non-zero data post eof while reading. Fix: In f2fs_truncate_partial_cluster(), let change as below to fix: - call filemap_write_and_wait_range() to flush dirty page - call truncate_pagecache() to drop pages or zero partial page post eof - call f2fs_do_truncate_blocks() to truncate non-compress cluster to last valid block Fixes: 3265d3db1f16 ("f2fs: support partial truncation on compressed inode") Reported-by: Jan Prusakowski Signed-off-by: Chao Yu --- v4: - update commit message to avoid typo and misunderstanding. fs/f2fs/compress.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index 6cd8902849cf..72bc05b913af 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -1246,19 +1246,28 @@ int f2fs_truncate_partial_cluster(struct inode *inode, u64 from, bool lock) for (i = cluster_size - 1; i >= 0; i--) { struct folio *folio = page_folio(rpages[i]); loff_t start = (loff_t)folio->index << PAGE_SHIFT; + loff_t offset = from > start ? from - start : 0; - if (from <= start) { - folio_zero_segment(folio, 0, folio_size(folio)); - } else { - folio_zero_segment(folio, from - start, - folio_size(folio)); + folio_zero_segment(folio, offset, folio_size(folio)); + + if (from >= start) break; - } } f2fs_compress_write_end(inode, fsdata, start_idx, true); + + err = filemap_write_and_wait_range(inode->i_mapping, + round_down(from, cluster_size << PAGE_SHIFT), + LLONG_MAX); + if (err) + return err; + + truncate_pagecache(inode, from); + + err = f2fs_do_truncate_blocks(inode, + round_up(from, PAGE_SIZE), lock); } - return 0; + return err; } static int f2fs_write_compressed_pages(struct compress_ctx *cc, -- 2.49.0 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel