From patchwork Mon Oct 18 17:57:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 12567559 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4EAD8C433EF for ; Mon, 18 Oct 2021 17:57:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 040DC60F02 for ; Mon, 18 Oct 2021 17:57:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 040DC60F02 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 920E9900003; Mon, 18 Oct 2021 13:57:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8A95E900002; Mon, 18 Oct 2021 13:57:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 72388900003; Mon, 18 Oct 2021 13:57:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0056.hostedemail.com [216.40.44.56]) by kanga.kvack.org (Postfix) with ESMTP id 5BE3E900002 for ; Mon, 18 Oct 2021 13:57:34 -0400 (EDT) Received: from smtpin39.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 0724D18280022 for ; Mon, 18 Oct 2021 17:57:34 +0000 (UTC) X-FDA: 78710315628.39.D276446 Received: from out01.mta.xmission.com (out01.mta.xmission.com [166.70.13.231]) by imf27.hostedemail.com (Postfix) with ESMTP id 7399970000B4 for ; Mon, 18 Oct 2021 17:57:32 +0000 (UTC) Received: from in01.mta.xmission.com ([166.70.13.51]:54484) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mcWt9-008qvU-Mx; Mon, 18 Oct 2021 11:57:31 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:47776 helo=email.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mcWt8-004BEZ-T2; Mon, 18 Oct 2021 11:57:31 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Alexey Gladkov Cc: Rune Kleveland , Yu Zhao , Jordan Glover , LKML , linux-mm@kvack.org, containers@lists.linux-foundation.org, Hillf Danton References: <1M9_d6wrcu6rdPe1ON0_k0lOxJMyyot3KAb1gdyuwzDPC777XVUWPHoTCEVmcK3fYfgu7sIo3PSaLe9KulUdm4TWVuqlbKyYGxRAjsf_Cpk=@protonmail.ch> <87ee9pa6xw.fsf@disp2133> <878rzw77i3.fsf@disp2133> <20210929173611.fo5traia77o63gpw@example.org> <20210930130640.wudkpmn3cmah2cjz@example.org> <878rz8wwb6.fsf@disp2133> <87v92cvhbf.fsf@disp2133> <87mtnavszx.fsf_-_@disp2133> <87fssytizw.fsf_-_@disp2133> <871r4itfjw.fsf_-_@disp2133> <877dearzfo.fsf_-_@disp2133> Date: Mon, 18 Oct 2021 12:57:24 -0500 In-Reply-To: <877dearzfo.fsf_-_@disp2133> (Eric W. Biederman's message of "Mon, 18 Oct 2021 12:54:35 -0500") Message-ID: <87k0iaqkqj.fsf_-_@disp2133> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 X-XM-SPF: eid=1mcWt8-004BEZ-T2;;;mid=<87k0iaqkqj.fsf_-_@disp2133>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/7j5xL28hfY6kDtmDx4X8fp6SFa2Mv6DA= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 4/4] ucounts: Use atomic_long_sub_return for clarity X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) X-Rspamd-Queue-Id: 7399970000B4 X-Stat-Signature: 89nzocndc4thsgusnf7am5kaf6su9fth Authentication-Results: imf27.hostedemail.com; dkim=none; spf=pass (imf27.hostedemail.com: domain of ebiederm@xmission.com designates 166.70.13.231 as permitted sender) smtp.mailfrom=ebiederm@xmission.com; dmarc=pass (policy=none) header.from=xmission.com X-Rspamd-Server: rspam02 X-HE-Tag: 1634579852-996709 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Decrement ucounts using atomic_long_sub_return to make it clear the point is for the ucount to decrease. Not a big deal but it should make it easier to catch bugs. Suggested-by: Yu Zhao Signed-off-by: "Eric W. Biederman" --- kernel/ucount.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/ucount.c b/kernel/ucount.c index 133b6044fda4..4f5613dac227 100644 --- a/kernel/ucount.c +++ b/kernel/ucount.c @@ -282,7 +282,7 @@ bool dec_rlimit_ucounts(struct ucounts *ucounts, enum ucount_type type, long v) struct ucounts *iter; long new = -1; /* Silence compiler warning */ for (iter = ucounts; iter; iter = iter->ns->ucounts) { - long dec = atomic_long_add_return(-v, &iter->ucount[type]); + long dec = atomic_long_sub_return(v, &iter->ucount[type]); WARN_ON_ONCE(dec < 0); if (iter == ucounts) new = dec; @@ -295,7 +295,7 @@ static void do_dec_rlimit_put_ucounts(struct ucounts *ucounts, { struct ucounts *iter, *next; for (iter = ucounts; iter != last; iter = next) { - long dec = atomic_long_add_return(-1, &iter->ucount[type]); + long dec = atomic_long_sub_return(1, &iter->ucount[type]); WARN_ON_ONCE(dec < 0); next = iter->ns->ucounts; if (dec == 0) @@ -332,7 +332,7 @@ long inc_rlimit_get_ucounts(struct ucounts *ucounts, enum ucount_type type) } return ret; dec_unwind: - dec = atomic_long_add_return(-1, &iter->ucount[type]); + dec = atomic_long_sub_return(1, &iter->ucount[type]); WARN_ON_ONCE(dec < 0); unwind: do_dec_rlimit_put_ucounts(ucounts, iter, type);