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=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 C172EC2D0DB for ; Fri, 24 Jan 2020 11:21:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EA5520704 for ; Fri, 24 Jan 2020 11:21:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864878; bh=xx/5NPMChgsJxC9KdTXY9qZMPHMzyd1H6sdrMha8ULg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=hR+mieuPgvtuLyYUbqMYdawZX/tR0b5MnnoJbRGD17oFUlUSq7mxpQx2lyFjezy0q dNzphWXS0rWAayQVAspNV6zRY3anneM6BNol9CrVHDNphEYI2+rsUlNFdTX5PL5iLY 5YkccYKJs4shSfOpyJkYbP2BAAi5vwn2GZ717i8U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391042AbgAXLVR (ORCPT ); Fri, 24 Jan 2020 06:21:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:59232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733219AbgAXLVO (ORCPT ); Fri, 24 Jan 2020 06:21:14 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (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 1C06B206D4; Fri, 24 Jan 2020 11:21:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864873; bh=xx/5NPMChgsJxC9KdTXY9qZMPHMzyd1H6sdrMha8ULg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fbg9qf67A2IFnM4gpit2hpktyM/Hp97sUaVHNZkaj6v54bKZzcLGlE/E7x3GZiB2q VMz1xjADGX6s+02t9gSHHkrXt3mGjqxLlKchon98b3NTIiW0HmwsKXowi7wLZAkBVP 4l1eEOy60W+C+HdlvBixujJcvdtSkLTJ0T8xIv7M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Howells , Sasha Levin Subject: [PATCH 4.19 377/639] afs: Fix lock-wait/callback-break double locking Date: Fri, 24 Jan 2020 10:29:07 +0100 Message-Id: <20200124093134.233102242@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@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: David Howells [ Upstream commit c7226e407b6065d3bda8bd9dc627663d2c505ea3 ] __afs_break_callback() holds vnode->lock around its call of afs_lock_may_be_available() - which also takes that lock. Fix this by not taking the lock in __afs_break_callback(). Also, there's no point checking the granted_locks and pending_locks queues; it's sufficient to check lock_state, so move that check out of afs_lock_may_be_available() into __afs_break_callback() to replace the queue checks. Fixes: e8d6c554126b ("AFS: implement file locking") Signed-off-by: David Howells Signed-off-by: Sasha Levin --- fs/afs/callback.c | 8 +------- fs/afs/flock.c | 3 --- 2 files changed, 1 insertion(+), 10 deletions(-) diff --git a/fs/afs/callback.c b/fs/afs/callback.c index 4ad7012502998..97283b04fa6fd 100644 --- a/fs/afs/callback.c +++ b/fs/afs/callback.c @@ -221,14 +221,8 @@ void afs_break_callback(struct afs_vnode *vnode) vnode->cb_break++; afs_clear_permits(vnode); - spin_lock(&vnode->lock); - - _debug("break callback"); - - if (list_empty(&vnode->granted_locks) && - !list_empty(&vnode->pending_locks)) + if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB) afs_lock_may_be_available(vnode); - spin_unlock(&vnode->lock); } write_sequnlock(&vnode->cb_lock); diff --git a/fs/afs/flock.c b/fs/afs/flock.c index aea7224ba1981..fbf4986b12245 100644 --- a/fs/afs/flock.c +++ b/fs/afs/flock.c @@ -39,9 +39,6 @@ void afs_lock_may_be_available(struct afs_vnode *vnode) { _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode); - if (vnode->lock_state != AFS_VNODE_LOCK_WAITING_FOR_CB) - return; - spin_lock(&vnode->lock); if (vnode->lock_state == AFS_VNODE_LOCK_WAITING_FOR_CB) afs_next_locker(vnode, 0); -- 2.20.1