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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 9A9CCC2B9F4 for ; Tue, 22 Jun 2021 15:10:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EBC2A611BF for ; Tue, 22 Jun 2021 15:10:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EBC2A611BF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=szeredi.hu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id DD2346B0070; Tue, 22 Jun 2021 11:10:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D82616B0071; Tue, 22 Jun 2021 11:10:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C4C126B0072; Tue, 22 Jun 2021 11:10:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0204.hostedemail.com [216.40.44.204]) by kanga.kvack.org (Postfix) with ESMTP id 883546B0070 for ; Tue, 22 Jun 2021 11:10:17 -0400 (EDT) Received: from smtpin33.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id B5519181AEF1F for ; Tue, 22 Jun 2021 15:10:17 +0000 (UTC) X-FDA: 78281695674.33.C31FD67 Received: from mail-vs1-f54.google.com (mail-vs1-f54.google.com [209.85.217.54]) by imf12.hostedemail.com (Postfix) with ESMTP id 015311428 for ; Tue, 22 Jun 2021 15:10:16 +0000 (UTC) Received: by mail-vs1-f54.google.com with SMTP id j8so11437915vsd.0 for ; Tue, 22 Jun 2021 08:10:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=o6jYECB1uY4kERwbwvQK62eKjskNIcvHqO/SelbLP+4=; b=pAN82221DIsUtrhb0p19lThHLu2emVpyjnLMrwRYEYMDXMZmJmomO2VGncVefPqeLk PnDv1mRg1xC4M0pPQpPSCfRUjwORrNe8KO6RCkK4uVhwO535jnc00YuKndimXSYZwRrL 1qYgII3/HAmV7OjzDGHqcVLo+eR9flvdOJ94w= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=o6jYECB1uY4kERwbwvQK62eKjskNIcvHqO/SelbLP+4=; b=SHez+5nfKz9bU7zfYKBMW7+2VnFuBDElP9qJOVLUGfKgOdiwe0p0DxfdyY2hItPM1e QinIe3jBs67w/qQhIp9UqFQX9pn2Pyq2lWYbwgnFkvTKcXW2oIi26pIzhFNqx59K3t7+ xrpObXRgTYfehOJolk6EnY/E2+u0IBfRgFPvW0FQYkX0Qs9bMVAO+lwOEra/1roQZHqT Ya8oL1ZdPuzObBER3rYnq3QC+N8+rmvtmqb1bWoj/ZTIfuXG5AgtxXAJvly0XFp8xy0h kCjOqzN1ImpQPwc6qndO4inYU1RlYJNO+sTYTxmHhVEGHl2hXC/WNwKQoCKj5iIZfRkN O09Q== X-Gm-Message-State: AOAM5304VmCpV/lfed2BR0QheJ/xqtha+8tq4B7pQM3WRqxiP3+OaIeR y0QE0JP7UAJu41k1H81CC+ofYMVxIE03Zqe0AvAc7g== X-Google-Smtp-Source: ABdhPJzX7TH0X2nUVdZbCqZU8+z232mRwthdahvJ7HHQQYRERYGZF4uBl6yHl06y7O/o8Q4PJiqE+3iLP0fzGCmWnEM= X-Received: by 2002:a67:bb14:: with SMTP id m20mr23694461vsn.0.1624374616050; Tue, 22 Jun 2021 08:10:16 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Miklos Szeredi Date: Tue, 22 Jun 2021 17:10:05 +0200 Message-ID: Subject: Re: [PATCH] ovl: fix mmap denywrite To: =?UTF-8?Q?Christian_K=C3=B6nig?= Cc: linux-fsdevel@vger.kernel.org, linux-mm , Chengguang Xu , overlayfs Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 015311428 Authentication-Results: imf12.hostedemail.com; dkim=none ("invalid DKIM record") header.d=szeredi.hu header.s=google header.b=pAN82221; spf=pass (imf12.hostedemail.com: domain of miklos@szeredi.hu designates 209.85.217.54 as permitted sender) smtp.mailfrom=miklos@szeredi.hu; dmarc=none X-Stat-Signature: s6amyizitezjmkps5b6ngxrkagxkwrjo X-HE-Tag: 1624374616-871981 X-Bogosity: Ham, tests=bogofilter, spamicity=0.026663, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 22 Jun 2021 at 14:43, Christian K=C3=B6nig wrote: > > Am 22.06.21 um 14:30 schrieb Miklos Szeredi: > > Overlayfs did not honor positive i_writecount on realfile for VM_DENYWR= ITE > > mappings. Similarly negative i_mmap_writable counts were ignored for > > VM_SHARED mappings. > > > > Fix by making vma_set_file() switch the temporary counts obtained and > > released by mmap_region(). > > Mhm, I don't fully understand the background but that looks like > something specific to overlayfs to me. > > So why are you changing the common helper? Need to hold the temporary counts until the final ones are obtained in vma_link(), which is out of overlayfs' scope. Thanks, Miklos