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 X-Spam-Level: X-Spam-Status: No, score=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35409C46471 for ; Sun, 5 Aug 2018 15:05:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDF7121888 for ; Sun, 5 Aug 2018 15:05:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="0novPEVe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDF7121888 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726501AbeHERKM (ORCPT ); Sun, 5 Aug 2018 13:10:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:41138 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726204AbeHERKM (ORCPT ); Sun, 5 Aug 2018 13:10:12 -0400 Received: from localhost.localdomain (unknown [49.77.238.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AF43621885; Sun, 5 Aug 2018 15:05:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1533481518; bh=2hEFIvEtwX7SkoJ+rX/3ZOWeZ3DNR37ztxvYsKfiDcQ=; h=From:To:Cc:Subject:Date:From; b=0novPEVe+VOh+8mtgEL0OqxpM0mX3kTe//IR0AazqJipMqq8X01XbupApqoXE9S7j CSN1UdyBs7LkArQY5Mgh1gvF6t8oathId8B0NphdQy9Y6kDNW70NxambyVK0svBMYy 6D/Q4zBwu92ny4tTITm85iyylDm+1cGs8BTAyO8M= From: Chao Yu To: jaegeuk@kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Chao Yu Subject: [PATCH v2 3/4] f2fs: fix avoid race between truncate and background GC Date: Sun, 5 Aug 2018 23:04:25 +0800 Message-Id: <20180805150425.9433-1-chao@kernel.org> X-Mailer: git-send-email 2.18.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chao Yu Thread A Background GC - f2fs_setattr isize to 0 - truncate_setsize - gc_data_segment - f2fs_get_read_data_page page #0 - set_page_dirty - set_cold_data - f2fs_truncate - f2fs_setattr isize to 4k - read 4k <--- hit data in cached page #0 Above race condition can cause read out invalid data in a truncated page, fix it by i_gc_rwsem[WRITE] lock. Signed-off-by: Chao Yu --- v2: - decrease i_gc_rwsem lock coverage. fs/f2fs/data.c | 4 ++++ fs/f2fs/file.c | 37 +++++++++++++++++++++++-------------- 2 files changed, 27 insertions(+), 14 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 1e6cc68fb7c4..45f043ee48bd 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2199,8 +2199,12 @@ static void f2fs_write_failed(struct address_space *mapping, loff_t to) if (to > i_size) { down_write(&F2FS_I(inode)->i_mmap_sem); + down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); + truncate_pagecache(inode, i_size); f2fs_truncate_blocks(inode, i_size, true); + + up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); up_write(&F2FS_I(inode)->i_mmap_sem); } } diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index bcffb3b608ed..84f9d15788d1 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -796,22 +796,26 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr) } if (attr->ia_valid & ATTR_SIZE) { - if (attr->ia_size <= i_size_read(inode)) { - down_write(&F2FS_I(inode)->i_mmap_sem); - truncate_setsize(inode, attr->ia_size); + bool to_smaller = (attr->ia_size <= i_size_read(inode)); + + down_write(&F2FS_I(inode)->i_mmap_sem); + down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); + + truncate_setsize(inode, attr->ia_size); + + if (to_smaller) err = f2fs_truncate(inode); - up_write(&F2FS_I(inode)->i_mmap_sem); - if (err) - return err; - } else { - /* - * do not trim all blocks after i_size if target size is - * larger than i_size. - */ - down_write(&F2FS_I(inode)->i_mmap_sem); - truncate_setsize(inode, attr->ia_size); - up_write(&F2FS_I(inode)->i_mmap_sem); + /* + * do not trim all blocks after i_size if target size is + * larger than i_size. + */ + up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); + up_write(&F2FS_I(inode)->i_mmap_sem); + + if (err) + return err; + if (!to_smaller) { /* should convert inline inode here */ if (!f2fs_may_inline_data(inode)) { err = f2fs_convert_inline_inode(inode); @@ -958,13 +962,18 @@ static int punch_hole(struct inode *inode, loff_t offset, loff_t len) blk_start = (loff_t)pg_start << PAGE_SHIFT; blk_end = (loff_t)pg_end << PAGE_SHIFT; + down_write(&F2FS_I(inode)->i_mmap_sem); + down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); + truncate_inode_pages_range(mapping, blk_start, blk_end - 1); f2fs_lock_op(sbi); ret = f2fs_truncate_hole(inode, pg_start, pg_end); f2fs_unlock_op(sbi); + + up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); up_write(&F2FS_I(inode)->i_mmap_sem); } } -- 2.18.0