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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 C8A87C4CECE for ; Mon, 14 Oct 2019 21:30:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9AE7D21835 for ; Mon, 14 Oct 2019 21:30:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731967AbfJNVaZ (ORCPT ); Mon, 14 Oct 2019 17:30:25 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45846 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729900AbfJNVaY (ORCPT ); Mon, 14 Oct 2019 17:30:24 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D68DC308FFB1 for ; Mon, 14 Oct 2019 21:30:24 +0000 (UTC) Received: from [IPv6:::1] (ovpn04.gateway.prod.ext.phx2.redhat.com [10.5.9.4]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AECD66012C for ; Mon, 14 Oct 2019 21:30:24 +0000 (UTC) To: fsdevel From: Eric Sandeen Subject: [PATCH V2] fs: avoid softlockups in s_inodes iterators Message-ID: Date: Mon, 14 Oct 2019 16:30:24 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Mon, 14 Oct 2019 21:30:24 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Anything that walks all inodes on sb->s_inodes list without rescheduling risks softlockups. Previous efforts were made in 2 functions, see: c27d82f fs/drop_caches.c: avoid softlockups in drop_pagecache_sb() ac05fbb inode: don't softlockup when evicting inodes but there hasn't been an audit of all walkers, so do that now. This also consistently moves the cond_resched() calls to the bottom of each loop in cases where it already exists. One loop remains: remove_dquot_ref(), because I'm not quite sure how to deal with that one w/o taking the i_lock. Signed-off-by: Eric Sandeen --- V2: Drop unrelated iput cleanups in fsnotify diff --git a/fs/drop_caches.c b/fs/drop_caches.c index d31b6c72b476..dc1a1d5d825b 100644 --- a/fs/drop_caches.c +++ b/fs/drop_caches.c @@ -35,11 +35,11 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused) spin_unlock(&inode->i_lock); spin_unlock(&sb->s_inode_list_lock); - cond_resched(); invalidate_mapping_pages(inode->i_mapping, 0, -1); iput(toput_inode); toput_inode = inode; + cond_resched(); spin_lock(&sb->s_inode_list_lock); } spin_unlock(&sb->s_inode_list_lock); diff --git a/fs/inode.c b/fs/inode.c index fef457a42882..b0c789bb3dba 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -676,6 +676,7 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty) struct inode *inode, *next; LIST_HEAD(dispose); +again: spin_lock(&sb->s_inode_list_lock); list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { spin_lock(&inode->i_lock); @@ -698,6 +699,13 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty) inode_lru_list_del(inode); spin_unlock(&inode->i_lock); list_add(&inode->i_lru, &dispose); + + if (need_resched()) { + spin_unlock(&sb->s_inode_list_lock); + cond_resched(); + dispose_list(&dispose); + goto again; + } } spin_unlock(&sb->s_inode_list_lock); diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 2ecef6155fc0..ac9eb273e28c 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -77,6 +77,7 @@ static void fsnotify_unmount_inodes(struct super_block *sb) iput_inode = inode; + cond_resched(); spin_lock(&sb->s_inode_list_lock); } spin_unlock(&sb->s_inode_list_lock); diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 6e826b454082..4a085b3c7cac 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -985,6 +985,7 @@ static int add_dquot_ref(struct super_block *sb, int type) * later. */ old_inode = inode; + cond_resched(); spin_lock(&sb->s_inode_list_lock); } spin_unlock(&sb->s_inode_list_lock);