From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752941AbeDRJpY (ORCPT ); Wed, 18 Apr 2018 05:45:24 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:38411 "EHLO huawei.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751870AbeDRJpV (ORCPT ); Wed, 18 Apr 2018 05:45:21 -0400 From: Chao Yu To: CC: , , , Chao Yu Subject: [PATCH 1/5] f2fs: fix race in between GC and atomic open Date: Wed, 18 Apr 2018 17:45:01 +0800 Message-ID: <20180418094505.98888-1-yuchao0@huawei.com> X-Mailer: git-send-email 2.15.0.55.gc2ece9dc4de6 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.120.216.130] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thread GC thread - f2fs_ioc_start_atomic_write - get_dirty_pages - filemap_write_and_wait_range - f2fs_gc - do_garbage_collect - gc_data_segment - move_data_page - f2fs_is_atomic_file - set_page_dirty - set_inode_flag(, FI_ATOMIC_FILE) Dirty data page can still be generated by GC in race condition as above call stack. This patch adds fi->dio_rwsem[WRITE] in f2fs_ioc_start_atomic_write to avoid such race. Signed-off-by: Chao Yu --- fs/f2fs/file.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 78b3a58cfe21..408471bf4799 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1677,6 +1677,8 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) inode_lock(inode); + down_write(&F2FS_I(inode)->dio_rwsem[WRITE]); + if (f2fs_is_atomic_file(inode)) goto out; @@ -1702,6 +1704,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) stat_inc_atomic_write(inode); stat_update_max_atomic_write(inode); out: + up_write(&F2FS_I(inode)->dio_rwsem[WRITE]); inode_unlock(inode); mnt_drop_write_file(filp); return ret; -- 2.15.0.55.gc2ece9dc4de6