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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 EC159C33C9E for ; Sat, 11 Jan 2020 10:17:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3ED92082E for ; Sat, 11 Jan 2020 10:17:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578737875; bh=ZcTsifWem0eSkVnmFP7zkUEfZC5rRi4x95HHdQZ3e7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=R6hd//atveR67sUp0hbzI9Bn5VaBt+IEfpzwWkqQj8pIroqBWCl8BM+mmeJ+fumD4 CqLUjBGZL8isXSkO7Cp6xFgpIq0RoL7Jq4Ulpz1pVZMclB/6UA92NLk+9CebovKwvN +hGvrOXN3T8CR150Fj+ugQbp96ZvGMQFMn75U1CM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730421AbgAKKRy (ORCPT ); Sat, 11 Jan 2020 05:17:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:34986 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728946AbgAKKRs (ORCPT ); Sat, 11 Jan 2020 05:17:48 -0500 Received: from localhost (unknown [62.119.166.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 29D2820842; Sat, 11 Jan 2020 10:17:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578737867; bh=ZcTsifWem0eSkVnmFP7zkUEfZC5rRi4x95HHdQZ3e7w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j1mCOjJ4+/8yDWkbbILpmNq+4Iz9XWdBUu+LkYrDRe5iVS1r9x6wxrEpIh0uyn875 3tZOzifakdhWvgpjEfaY2KTrBV9mTrPyn6yx0OU9s9eAkgUZk3JCBLcsCYy5QV17UA 6rdsAFzlsd2Ah4Z+6D+fGp0XryK2NQ0KwIN3M0h4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Sandeen , Jan Kara , Al Viro , Sasha Levin Subject: [PATCH 4.19 47/84] fs: avoid softlockups in s_inodes iterators Date: Sat, 11 Jan 2020 10:50:24 +0100 Message-Id: <20200111094904.123179432@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200111094845.328046411@linuxfoundation.org> References: <20200111094845.328046411@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Sandeen [ Upstream commit 04646aebd30b99f2cfa0182435a2ec252fcb16d0 ] 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 Reviewed-by: Jan Kara Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- fs/drop_caches.c | 2 +- fs/inode.c | 7 +++++++ fs/notify/fsnotify.c | 1 + fs/quota/dquot.c | 1 + 4 files changed, 10 insertions(+), 1 deletion(-) 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 5c63693326bb..9c50521c9fe4 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -660,6 +660,7 @@ 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); @@ -682,6 +683,12 @@ 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 170a733454f7..e8ee4263d7b2 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -90,6 +90,7 @@ 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 154f175066b3..1d1d393f4208 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -980,6 +980,7 @@ 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); -- 2.20.1