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=-7.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 CDB83C43610 for ; Thu, 29 Nov 2018 14:32:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 947B42146F for ; Thu, 29 Nov 2018 14:32:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="1wSxhGNF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 947B42146F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389629AbeK3Bi3 (ORCPT ); Thu, 29 Nov 2018 20:38:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:42066 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732483AbeK3Bi1 (ORCPT ); Thu, 29 Nov 2018 20:38:27 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 313B5213A2; Thu, 29 Nov 2018 14:32:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543501974; bh=5GTV/uNPYmmzougMSUCYronxFxCFZbx7OGYHxGKfpa4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1wSxhGNFNgRm8Hqq12/94xw2bwLHa2IFLRIgfY7oTprB+oYVsoPxh0P3ZR267d92n 19qS+aPz2j11sUUvjWNGuILlFeqlMAndI+onQT/h6kxwmte/+7W4Epj+3Iz95pIdUk HPawS7zBVGv5DLRAi6fAL2sLSmfcfMYBLgtYGzfc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthew Wilcox Subject: [PATCH 4.19 099/110] dax: Avoid losing wakeup in dax_lock_mapping_entry Date: Thu, 29 Nov 2018 15:13:10 +0100 Message-Id: <20181129135925.248125334@linuxfoundation.org> X-Mailer: git-send-email 2.19.2 In-Reply-To: <20181129135921.231283053@linuxfoundation.org> References: <20181129135921.231283053@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matthew Wilcox commit 25bbe21bf427a81b8e3ccd480ea0e1d940256156 upstream. After calling get_unlocked_entry(), you have to call put_unlocked_entry() to avoid subsequent waiters losing wakeups. Fixes: c2a7d2a11552 ("filesystem-dax: Introduce dax_lock_mapping_entry()") Cc: stable@vger.kernel.org Signed-off-by: Matthew Wilcox Signed-off-by: Greg Kroah-Hartman --- fs/dax.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/fs/dax.c +++ b/fs/dax.c @@ -217,6 +217,9 @@ static inline void *unlock_slot(struct a return (void *)entry; } +static void put_unlocked_mapping_entry(struct address_space *mapping, + pgoff_t index, void *entry); + /* * Lookup entry in radix tree, wait for it to become unlocked if it is * exceptional entry and return it. The caller must call @@ -256,8 +259,10 @@ static void *__get_unlocked_mapping_entr revalidate = wait_fn(); finish_wait(wq, &ewait.wait); xa_lock_irq(&mapping->i_pages); - if (revalidate) + if (revalidate) { + put_unlocked_mapping_entry(mapping, index, entry); return ERR_PTR(-EAGAIN); + } } }