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=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 7E23FCA9EAF for ; Mon, 21 Oct 2019 19:03:38 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5173A2086D for ; Mon, 21 Oct 2019 19:03:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VPFLCqVK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5173A2086D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from new-ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id C49901007B1FF; Mon, 21 Oct 2019 12:04:12 -0700 (PDT) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=205.139.110.120; helo=us-smtp-1.mimecast.com; envelope-from=jmoyer@redhat.com; receiver= Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 31E2D100792EA for ; Mon, 21 Oct 2019 05:09:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571659665; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jZW2w85TwEDR7o6SJHU50uEOcHT5Iw+gP89ZUiYLiLY=; b=VPFLCqVKXG8ryyFxNxlnPORr0JlIJNViViCFzDv37GpQsfm6u2b14Mu74w+Mp3Yo3Tyxqd IB6TIMXo0yvznjnIXbyY8XjtSwNZDNZcaLFD4o+YyYaEHNeoihvIoN0l1pqPXb4d029Gzt Fw5YNRpffwxHOVQobhhADpkGi0K0QYA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-258-tqajfzzvNaaD0mZxWWnBcg-1; Mon, 21 Oct 2019 08:07:41 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1C8EF800D41; Mon, 21 Oct 2019 12:07:40 +0000 (UTC) Received: from segfault.boston.devel.redhat.com (segfault.boston.devel.redhat.com [10.19.60.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0CAC25D9E2; Mon, 21 Oct 2019 12:07:38 +0000 (UTC) From: Jeff Moyer To: Dan Williams Subject: Re: [PATCH] fs/dax: Fix pmd vs pte conflict detection References: <157150237973.3940076.12626102230619807187.stgit@dwillia2-desk3.amr.corp.intel.com> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 Date: Mon, 21 Oct 2019 08:07:38 -0400 In-Reply-To: <157150237973.3940076.12626102230619807187.stgit@dwillia2-desk3.amr.corp.intel.com> (Dan Williams's message of "Sat, 19 Oct 2019 09:26:19 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: tqajfzzvNaaD0mZxWWnBcg-1 X-Mimecast-Spam-Score: 0 Message-ID-Hash: 2RINEA6VRU3QELET7LFPTAMG7VJB2JWN X-Message-ID-Hash: 2RINEA6VRU3QELET7LFPTAMG7VJB2JWN X-MailFrom: jmoyer@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header CC: linux-fsdevel@vger.kernel.org, Jeff Smits , Doug Nelson , stable@vger.kernel.org, Jan Kara , "Matthew Wilcox (Oracle)" , linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Dan Williams writes: > Check for NULL entries before checking the entry order, otherwise NULL > is misinterpreted as a present pte conflict. The 'order' check needs to > happen before the locked check as an unlocked entry at the wrong order > must fallback to lookup the correct order. Please include the user-visible effects of the problem in the changelog. Thanks, Jeff > > Reported-by: Jeff Smits > Reported-by: Doug Nelson > Cc: > Fixes: 23c84eb78375 ("dax: Fix missed wakeup with PMD faults") > Cc: Jan Kara > Cc: Matthew Wilcox (Oracle) > Signed-off-by: Dan Williams > --- > fs/dax.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index a71881e77204..08160011d94c 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -221,10 +221,11 @@ static void *get_unlocked_entry(struct xa_state *xas, unsigned int order) > > for (;;) { > entry = xas_find_conflict(xas); > + if (!entry || WARN_ON_ONCE(!xa_is_value(entry))) > + return entry; > if (dax_entry_order(entry) < order) > return XA_RETRY_ENTRY; > - if (!entry || WARN_ON_ONCE(!xa_is_value(entry)) || > - !dax_is_locked(entry)) > + if (!dax_is_locked(entry)) > return entry; > > wq = dax_entry_waitqueue(xas, entry, &ewait.key); _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org