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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 AF934C43381 for ; Wed, 20 Mar 2019 02:56:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68310217F4 for ; Wed, 20 Mar 2019 02:56:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="BqQ9CbWv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727106AbfCTC44 (ORCPT ); Tue, 19 Mar 2019 22:56:56 -0400 Received: from mout.gmx.net ([212.227.17.22]:54345 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726937AbfCTC44 (ORCPT ); Tue, 19 Mar 2019 22:56:56 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1553050614; bh=446xnWccmwxmzq6ZScgPsRNAjdCDISotdcTHzMLPmFI=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=BqQ9CbWvwIMzL6FifHBNk3wK1Zt7iVOQBiPYhj5bmh3N8hZL7Y9EkwHeIgCcLx098 Rfw9WYXUwOx1w9hWdHD8zIC93u2nOAvIpWSFCiIchEZYhNVwCfs7BZP/dZCPrdNI5a Flm5ArClXWS88pH7/GFrk5dYSQeVYAABHzL64zPY= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [192.168.183.223] ([218.18.229.179]) by mail.gmx.com (mrgmx102 [212.227.17.174]) with ESMTPSA (Nemesis) id 0MZOan-1hR7zU3Zin-00LAta; Wed, 20 Mar 2019 03:56:54 +0100 Subject: Re: [PATCH 1/2] block: increase bio_slab_nr only for necessary case To: axboe@kernel.dk Cc: linux-block@vger.kernel.org References: <20190308101540.24337-1-cgxu519@gmx.com> From: cgxu519 Message-ID: <672a4135-9d68-e6c9-f9b6-c759018c3d65@gmx.com> Date: Wed, 20 Mar 2019 10:56:50 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: <20190308101540.24337-1-cgxu519@gmx.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable Content-Language: en-US X-Provags-ID: V03:K1:w+GUcBWeiDFy+BoM5+Q9RmJfIJZsHbgqQtur1c68KTMVLQlDnlD jwgoyMntJS+LalkB2ZGhoCeKQWHQEWfN58gyqehiOyhPAK8B65tCZsgp0IqyMOQrJS7eXwG jSUEbW+qa/Kuv6NL1vMCOcrhxibva4rF72o0VIGvOzqOtxzsR8J7kvMBQvz6u5gCBLzs//Y c+9pMsBho4k1a3i5Mx+pg== X-UI-Out-Filterresults: notjunk:1;V03:K0:SSCdehzoSBE=:VGKqvLFDN7aUrsMOTqS15t xSTh2wlWb0kWD93I2293X3YZ6+SgcJUyZtaB5cy+aqzDewtCBy8W1MiFNHyINdx/7YJ0UNxv5 34kwKIUu1EWUuwmgKwwUQ9wIYBYf8N6IYkTsC6jDoIY8HhGyjGCjFd5vlg+wyTyODTI453C0N UJczCn+5HLVj4aqmYLIXGJlJiyFVczfZhPKx4P4T3oPHyXgbNJBdu3oPKMrAv2ZuiBPuSkVqE KCDlAFwBC5HtxHntYHLEUcS7Jq2fQd8uZcHtKu4l0zLwAtB2vTYwU3h9upjyQxVdPHnxpDwu9 WcvSZfCTAwlc5mvHciv3nVb9S/V0jDVewbIGpy/ucMyxlzgSscGmkG1ppVEOIMP54si0uqCqQ LK/EsQ3OFJh2fa6dMlMuoW8DwPIovmsd03h6aSdhCtjx5+uW2zhXV8baU0E+zjAneuex0s8cT Ej1Yn47FBdD5cCvmfVZhEIGwTdA57230kvUTGwxzvztUAMpiJOeAjSah4K0EhERGNcnt1jXwk MDXlmAyAcIfuPIzlD8c5r4h0IyHUBPMdOYdrdt0Eiq3N7FHh3lCZGSSJioOE5RpBFnz+34W2Q 9vIKrmlrEMN9T9fYMv/dINSbkAWJVDFlsIRy9naUWahFJfEDzynrjSAe93hy7L1bOZnqFE56m bjP50OM5birnutP+NhRKEFmQ6PtU/PAyvcb05ue7+6zomHKDboIeKW0anX4+cknaX9CYJzDUj L3gM/aaZHZ7cvHHgWGA4NcdvlcAB+HGu2tIKNAQLi+SDT/0Kk8gOqpvGcaGMWhzWpt9ya7CAw 0y60TOKtQ2hxvgCLAsjrRBdlEkjYYa9720v9FeFcGX27xWdbjRVzQh2HyCb3Iq7UpW4qbLBUY ky2cHJ8ZPPrMlTVQpYmq39Xng1OTTQDy9QBi17SgwH/jyj9Cd3X9OxA/Gy+g5VKJ9kNe2ondI OHDMnv0Wutw== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 3/8/19 6:15 PM, Chengguang Xu wrote: > When fail to create new cache in bio_find_or_create_slab(), > we should not increase bio_slab_nr because it will cause > referring uninitilized data in subsequent search. > > Signed-off-by: Chengguang Xu > --- > block/bio.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/block/bio.c b/block/bio.c > index 4db1008309ed..8081906f5d01 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -109,7 +109,7 @@ static struct kmem_cache *bio_find_or_create_slab(un= signed int extra_size) > bio_slabs =3D new_bio_slabs; > } > if (entry =3D=3D -1) > - entry =3D bio_slab_nr++; > + entry =3D bio_slab_nr; > > bslab =3D &bio_slabs[entry]; > > @@ -122,6 +122,10 @@ static struct kmem_cache *bio_find_or_create_slab(u= nsigned int extra_size) > bslab->slab =3D slab; > bslab->slab_ref =3D 1; > bslab->slab_size =3D sz; > + > + if (entry =3D=3D bio_slab_nr) > + bio_slab_nr++; > + > out_unlock: > mutex_unlock(&bio_slab_lock); > return slab; Any suggestion? Thanks.