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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 11597C33CAF for ; Thu, 16 Jan 2020 18:55:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDFFD20663 for ; Thu, 16 Jan 2020 18:55:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579200948; bh=9ffIg72vfAL9XOeRGbQvUSJeUprb7SNydkmcRf2SO2o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=v+qWwpzThABMp4g4lQPjVW+Ar9EdJJwMeJxsXoyGGrf1ss9Uw5R5vsSYnafTxcnOw 0E4PpbuIy0AIuVR7GudRPZDE6vQbnF1ldR4BB/aGmMqbQhhKZ9qvgWeb95uRB5yggh pTFiAGPNzZLY+q0Hjlk2KoFMJB1EX0sk7feVI2mc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389594AbgAPSzr (ORCPT ); Thu, 16 Jan 2020 13:55:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:39646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729950AbgAPRHc (ORCPT ); Thu, 16 Jan 2020 12:07:32 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8897821582; Thu, 16 Jan 2020 17:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194452; bh=9ffIg72vfAL9XOeRGbQvUSJeUprb7SNydkmcRf2SO2o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0XcO2XazkZ77b+AhN+4jzVvtfR5ZJ4h3cWJh9X/76aBXYTLBtCfQgGb50/lHAgomB vyRVb24VOqQtTSGa+uRFDyrXjJ6BhlNrHslsjHE0NaK0G07r9MeyB9r/uuB+YrUFPF HywCBsxzMjrk4YJMFUKqJQJlLV+UDpPcj+S492LA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Howells , Sasha Levin , linux-afs@lists.infradead.org Subject: [PATCH AUTOSEL 4.19 362/671] afs: Fix lock-wait/callback-break double locking Date: Thu, 16 Jan 2020 12:00:00 -0500 Message-Id: <20200116170509.12787-99-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116170509.12787-1-sashal@kernel.org> References: <20200116170509.12787-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 4ad701250299..97283b04fa6f 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 075fe7f94810..457ce62e5c0f 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