From patchwork Fri Jun 3 13:49:56 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artem Bityutskiy X-Patchwork-Id: 98573 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 4F399B6FB0 for ; Fri, 3 Jun 2011 23:46:35 +1000 (EST) Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QSUhb-00014T-J4; Fri, 03 Jun 2011 13:46:15 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QSUhb-0004mW-8u; Fri, 03 Jun 2011 13:46:15 +0000 Received: from smtp.nokia.com ([147.243.1.47] helo=mgw-sa01.nokia.com) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QSUhL-0004hh-QL for linux-mtd@lists.infradead.org; Fri, 03 Jun 2011 13:46:01 +0000 Received: from eru.research.nokia.com (esdhcp038109.research.nokia.com [172.21.38.109]) by mgw-sa01.nokia.com (Switch-3.4.4/Switch-3.4.3) with ESMTP id p53Djuqi013884 for ; Fri, 3 Jun 2011 16:45:57 +0300 From: Artem Bityutskiy To: linux-mtd@lists.infradead.org Subject: [PATCH 05/10] UBIFS: fix shrinker object count reports Date: Fri, 3 Jun 2011 16:49:56 +0300 Message-Id: <1307109001-19761-6-git-send-email-dedekind1@gmail.com> X-Mailer: git-send-email 1.7.2.3 In-Reply-To: <1307109001-19761-1-git-send-email-dedekind1@gmail.com> References: <1307109001-19761-1-git-send-email-dedekind1@gmail.com> X-Nokia-AV: Clean X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110603_094600_333196_8A401A05 X-CRM114-Status: GOOD ( 14.99 ) X-Spam-Score: 3.4 (+++) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (3.4 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, low trust [147.243.1.47 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is freemail (dedekind1[at]gmail.com) 0.0 DKIM_ADSP_CUSTOM_MED No valid author signature, adsp_override is CUSTOM_MED 2.2 FREEMAIL_ENVFROM_END_DIGIT Envelope-from freemail username ends in digit (dedekind1[at]gmail.com) 0.0 RFC_ABUSE_POST Both abuse and postmaster missing on sender domain 1.2 NML_ADSP_CUSTOM_MED ADSP custom_med hit, and not from a mailing list 0.0 T_TO_NO_BRKTS_FREEMAIL T_TO_NO_BRKTS_FREEMAIL X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-mtd-bounces@lists.infradead.org Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Artem Bityutskiy Sometimes VM asks the shrinker to return amount of objects it can shrink, and we return the ubifs_clean_zn_cnt in that case. However, it is possible that this counter is negative for a short period of time, due to the way UBIFS TNC code updates it. And I can observe the following warnings sometimes: shrink_slab: ubifs_shrinker+0x0/0x2b7 [ubifs] negative objects to delete nr=-8541616642706119788 This patch makes sure UBIFS never returns negative count of objects. Signed-off-by: Artem Bityutskiy Cc: stable@kernel.org --- fs/ubifs/shrinker.c | 6 +++++- 1 files changed, 5 insertions(+), 1 deletions(-) diff --git a/fs/ubifs/shrinker.c b/fs/ubifs/shrinker.c index ca953a9..dfc105a 100644 --- a/fs/ubifs/shrinker.c +++ b/fs/ubifs/shrinker.c @@ -284,7 +284,11 @@ int ubifs_shrinker(struct shrinker *shrink, struct shrink_control *sc) long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt); if (nr == 0) - return clean_zn_cnt; + /* + * Due to the way UBIFS updates the clean znode counter it may + * temporarily be negative. + */ + return clean_zn_cnt > 0 ?: 1; if (!clean_zn_cnt) { /*