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=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1,USER_IN_DEF_DKIM_WL 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 B942EC43463 for ; Sun, 20 Sep 2020 18:49:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3BAA52073A for ; Sun, 20 Sep 2020 18:49:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GkypHfeN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3BAA52073A Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 91DBB900003; Sun, 20 Sep 2020 14:49:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8CE536B009A; Sun, 20 Sep 2020 14:49:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7E249900003; Sun, 20 Sep 2020 14:49:41 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0077.hostedemail.com [216.40.44.77]) by kanga.kvack.org (Postfix) with ESMTP id 658016B0098 for ; Sun, 20 Sep 2020 14:49:41 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 2A2778249980 for ; Sun, 20 Sep 2020 18:49:41 +0000 (UTC) X-FDA: 77284328562.20.pig92_1d0764a2713e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 09329180C07A3 for ; Sun, 20 Sep 2020 18:49:41 +0000 (UTC) X-HE-Tag: pig92_1d0764a2713e X-Filterd-Recvd-Size: 4497 Received: from mail-oi1-f193.google.com (mail-oi1-f193.google.com [209.85.167.193]) by imf04.hostedemail.com (Postfix) with ESMTP for ; Sun, 20 Sep 2020 18:49:40 +0000 (UTC) Received: by mail-oi1-f193.google.com with SMTP id z26so14308640oih.12 for ; Sun, 20 Sep 2020 11:49:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:mime-version; bh=T2hFKmZJlvTIbWOQCGeuk8z5hREoSVHVU52LKW8EOhQ=; b=GkypHfeNG9sKolaGeFYnd5pUpQ3Plcwj9YLNYxDMMhNy1MjZwta9buiSbQNhKR0w8b uoORmY+tDwnyCm2sJ12M2j+0EYUXshSt7oTdb8KFaAZI6clzshS5X8Zss8AoYZzjojNY a2pzJvwvg0blfztQHd+Bmb66j6PfiFV1eCHR3+uHFHizT+T2zxiqA+8oOcAX16QWql8k MiLLYh4C59S/Y5v7wq450yIBfvoSkkZhyvI6NQeuPXxgsIoLV+66+oRHfUYJJAdldT2d 0TWN+62SeSuE5PHsdQLXpi7qrvYN63SqvgYVZiri9JJRRPl/+g3p2cPIV9gcq2ejTbsl aJHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version; bh=T2hFKmZJlvTIbWOQCGeuk8z5hREoSVHVU52LKW8EOhQ=; b=EF5CUq5b+XpiptQugZBbrauAuYMswubz575fuBXDF2zw1I7Vm1BRMiiu6RdyglIid6 MTHbq6F9PpKWZ8v2euxBZAYoYZ33GCKZW3RyD/KL+xCBipLOr36G0dvPvDTZDoCK5dXm vuiB2PJ58Hg0SZSVFc0B1Vq/tYoDXoKCoNxp+KPzuTSTz1H2gECkd13hAGnhuWDel7o6 co1u5hMZVZBHMU/tItsHvLKqiwxYBt+3YTQzQu4gcRvqT6ztoNTDP+u0a9XeetciXsHr 6+cG/n44fwe7L/D68FesB51/oNhyrat8xB2LQLmG8mSBDZsk4inbjbQCaTJkVWpM7dQi LT1Q== X-Gm-Message-State: AOAM532vvHrEyDGlgaMqNfugvJ93HWnszf92bHcY6XMCZDBvJUNMW7Pk khLa60vi4QZWO1QZc+TWzzcVdg== X-Google-Smtp-Source: ABdhPJzdc9OCQsXRMp9Q5pIlzC47ECQfzDrkMTtjd82DubPRsr1YkLFqfY4C7mAaHoBKdIklPTe+Ag== X-Received: by 2002:a05:6808:14f:: with SMTP id h15mr14768940oie.119.1600627779649; Sun, 20 Sep 2020 11:49:39 -0700 (PDT) Received: from eggly.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id z8sm6418184oic.11.2020.09.20.11.49.37 (version=TLS1 cipher=ECDHE-ECDSA-AES128-SHA bits=128/128); Sun, 20 Sep 2020 11:49:38 -0700 (PDT) Date: Sun, 20 Sep 2020 11:49:20 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Tianjia Zhang cc: Hugh Dickins , Andrew Morton , Al Viro , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/shmem.c: Fix the missing unaccount on the failed path In-Reply-To: <20200920163005.97079-1-tianjia.zhang@linux.alibaba.com> Message-ID: References: <20200920163005.97079-1-tianjia.zhang@linux.alibaba.com> User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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: On Mon, 21 Sep 2020, Tianjia Zhang wrote: > In function __shmem_file_setup(), shmem_unacct_size() is forgotten > on the failed path, so add it. > > Fixes: 93dec2da7b234 ("... and switch shmem_file_setup() to alloc_file_pseudo()") > Cc: Al Viro > Signed-off-by: Tianjia Zhang > --- > mm/shmem.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index 8e2b35ba93ad..591410dc3541 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -4200,8 +4200,10 @@ static struct file *__shmem_file_setup(struct vfsmount *mnt, const char *name, l > if (!IS_ERR(res)) > res = alloc_file_pseudo(inode, mnt, name, O_RDWR, > &shmem_file_operations); > - if (IS_ERR(res)) > + if (IS_ERR(res)) { > iput(inode); > + shmem_unacct_size(flags, size); > + } > return res; > } > > -- > 2.19.1.3.ge56e4f7 Looks mistaken to me. Is this something you noticed by source inspection, or something you have observed in practice? I haven't tried exercising this path while injecting errors into alloc_file_pseudo(); but what I'd expect to happen is that the iput(inode), which you see already on that error path, will get to evict the inode, which will entail calling shmem_evict_inode(), which does that shmem_unacct_size() itself. Hugh