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 4B6F4FC08 for ; Mon, 15 May 2023 17:40:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 703E9C4339B; Mon, 15 May 2023 17:40:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1684172443; bh=192leasKzAIc4vYdJBRT3H2H51t6sT8tDQzqUBjRRQ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FfphZw8tMbndtGP/rNq6IVWn10u5rKxcNcR6f00yRWlGVbGVr/HZMbi4bJKcgiw34 jYYOw/Nb8evxJ9BxM1kMzNP1Zz04QJmNOXzxNTcMNUYoFsi31N2uoaug11kOYnT/2V hpCpeZ665sqVA8fUu5+/f0Ddm8wzJuWewslz7Qsk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christoph Hellwig , Qi Han , Yangtao Li , Chao Yu , Jaegeuk Kim , Sasha Levin Subject: [PATCH 5.10 154/381] f2fs: compress: fix to call f2fs_wait_on_page_writeback() in f2fs_write_raw_pages() Date: Mon, 15 May 2023 18:26:45 +0200 Message-Id: <20230515161743.779320364@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230515161736.775969473@linuxfoundation.org> References: <20230515161736.775969473@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Yangtao Li [ Upstream commit babedcbac164cec970872b8097401ca913a80e61 ] BUG_ON() will be triggered when writing files concurrently, because the same page is writtenback multiple times. 1597 void folio_end_writeback(struct folio *folio) 1598 { ...... 1618 if (!__folio_end_writeback(folio)) 1619 BUG(); ...... 1625 } kernel BUG at mm/filemap.c:1619! Call Trace: f2fs_write_end_io+0x1a0/0x370 blk_update_request+0x6c/0x410 blk_mq_end_request+0x15/0x130 blk_complete_reqs+0x3c/0x50 __do_softirq+0xb8/0x29b ? sort_range+0x20/0x20 run_ksoftirqd+0x19/0x20 smpboot_thread_fn+0x10b/0x1d0 kthread+0xde/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 Below is the concurrency scenario: [Process A] [Process B] [Process C] f2fs_write_raw_pages() - redirty_page_for_writepage() - unlock page() f2fs_do_write_data_page() - lock_page() - clear_page_dirty_for_io() - set_page_writeback() [1st writeback] ..... - unlock page() generic_perform_write() - f2fs_write_begin() - wait_for_stable_page() - f2fs_write_end() - set_page_dirty() - lock_page() - f2fs_do_write_data_page() - set_page_writeback() [2st writeback] This problem was introduced by the previous commit 7377e853967b ("f2fs: compress: fix potential deadlock of compress file"). All pagelocks were released in f2fs_write_raw_pages(), but whether the page was in the writeback state was ignored in the subsequent writing process. Let's fix it by waiting for the page to writeback before writing. Cc: Christoph Hellwig Fixes: 4c8ff7095bef ("f2fs: support data compression") Fixes: 7377e853967b ("f2fs: compress: fix potential deadlock of compress file") Signed-off-by: Qi Han Signed-off-by: Yangtao Li Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/compress.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index 1541da5ace85e..1be9de40f0b5a 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -1391,6 +1391,12 @@ static int f2fs_write_raw_pages(struct compress_ctx *cc, if (!PageDirty(cc->rpages[i])) goto continue_unlock; + if (PageWriteback(cc->rpages[i])) { + if (wbc->sync_mode == WB_SYNC_NONE) + goto continue_unlock; + f2fs_wait_on_page_writeback(cc->rpages[i], DATA, true, true); + } + if (!clear_page_dirty_for_io(cc->rpages[i])) goto continue_unlock; -- 2.39.2