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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,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 D80E6C43603 for ; Fri, 6 Dec 2019 03:32:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B23DB21823 for ; Fri, 6 Dec 2019 03:32:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726418AbfLFDcA (ORCPT ); Thu, 5 Dec 2019 22:32:00 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:7643 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726076AbfLFDcA (ORCPT ); Thu, 5 Dec 2019 22:32:00 -0500 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 67EADA3DF8EF18778786; Fri, 6 Dec 2019 11:31:58 +0800 (CST) Received: from szvp000203569.huawei.com (10.120.216.130) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.439.0; Fri, 6 Dec 2019 11:31:47 +0800 From: Chao Yu To: CC: , , , Chao Yu Subject: [PATCH] f2fs: fix to relocate f2fs_balance_fs() in mkwrite() Date: Fri, 6 Dec 2019 11:31:00 +0800 Message-ID: <20191206033100.36345-1-yuchao0@huawei.com> X-Mailer: git-send-email 2.18.0.rc1 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As Dinosaur Huang reported, there is a potential deadlock in between GC and mkwrite(): Thread A Thread B - do_page_mkwrite - f2fs_vm_page_mkwrite - lock_page - f2fs_balance_fs - mutex_lock(gc_mutex) - f2fs_gc - do_garbage_collect - ra_data_block - grab_cache_page - f2fs_balance_fs - mutex_lock(gc_mutex) In order to fix this, we just move f2fs_balance_fs() out of page lock's coverage in f2fs_vm_page_mkwrite(). Reported-by: Dinosaur Huang Signed-off-by: Chao Yu --- fs/f2fs/file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index c0560d62dbee..ed3290225506 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -67,6 +67,8 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) f2fs_bug_on(sbi, f2fs_has_inline_data(inode)); + f2fs_balance_fs(sbi, true); + file_update_time(vmf->vma->vm_file); down_read(&F2FS_I(inode)->i_mmap_sem); lock_page(page); @@ -120,8 +122,6 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) out_sem: up_read(&F2FS_I(inode)->i_mmap_sem); - f2fs_balance_fs(sbi, dn.node_changed); - sb_end_pagefault(inode->i_sb); err: return block_page_mkwrite_return(err); -- 2.18.0.rc1