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=-12.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 22AC1C43461 for ; Mon, 14 Sep 2020 13:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CB6DE208E4 for ; Mon, 14 Sep 2020 13:39:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LNYaV5ht" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726669AbgINNiz (ORCPT ); Mon, 14 Sep 2020 09:38:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726722AbgINN3z (ORCPT ); Mon, 14 Sep 2020 09:29:55 -0400 Received: from mail-ed1-x543.google.com (mail-ed1-x543.google.com [IPv6:2a00:1450:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F13B5C06178B; Mon, 14 Sep 2020 06:29:32 -0700 (PDT) Received: by mail-ed1-x543.google.com with SMTP id g4so17638622edk.0; Mon, 14 Sep 2020 06:29:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=2sgKFqAzyYTWFS7DpgNkPf7xuqkExWpe0vtA6hya4p8=; b=LNYaV5htN1AoGcRr3qutKAdIAJ9K2NpHJmZnCLnFDlG8+zhSr8pFBVrIVZbK7upLCy XuYIA5pbVz06HyYiXjA0CX8OrBfsP8QYVTX6yJ60VAjafiTzs3Dr1q7h1S6WN1SGAvlY UXlmfxZ5/aBJS18uzwRmNUI3/lYVMDzcdWcPZzIRtlGG2B6QiV90AnQEfAOpca3J5cuM fi/i79PCqkzlb/1pkXfPwtPFhCm+AEfUwe9iWPeCcG3ahwbSU9PfGzYe8A8PulfEuuIe /yCSNERBUwZ4Herw4m2hVxb+aHQ2rdJcpWKX6iPZoqfXgRCIkWGGqsSIIr4ud7pRIc3R 2DEg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=2sgKFqAzyYTWFS7DpgNkPf7xuqkExWpe0vtA6hya4p8=; b=AdEobLBxLwsypFTpwwmuXPs3IJYWarxtMVuuDDMehBV0ap8bz/C9eaDqvAMwr5xWhf LatGiZRNvPyJSIceFYo+OdA+zJIqBd6LrkiivACMfRS7fhQGM/jvecHfbrDrudhdF++0 u86No2bvYWZg6eEEgRhG9idyxKPidBPqVrgUweEJiu9l9eD6iC9jNxbmD8E8H6ML1xLg IIaXFx30rtFojSumicyAon89mousZPc5zAdywMRmHki4HdKP+AFUs2OueePk8oK6FAFt Ty8vWS4DiVH65NgH/m9RMYoylR4HzCMAtQITx3Hh/6djMEX8Ac0YxL3y1yzPkEQKq7OK 6I4g== X-Gm-Message-State: AOAM5304ixko22aLBDbL+mKEGgZ08GcSCONvwRgRKzUte8lh9M99aesM U1+HiJ1ThN/R9n/pPxSSPUE= X-Google-Smtp-Source: ABdhPJwqz+YzShnzPAVkh+LgWPDH996EZ9R5Asg2qCZETs+L6ijZw4dfeniXkQwebJgtgDxC1+lltA== X-Received: by 2002:aa7:cad3:: with SMTP id l19mr16523629edt.352.1600090171724; Mon, 14 Sep 2020 06:29:31 -0700 (PDT) Received: from abel.fritz.box ([2a02:908:1252:fb60:6179:d701:8021:da3d]) by smtp.gmail.com with ESMTPSA id d6sm9575625edm.31.2020.09.14.06.29.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Sep 2020 06:29:30 -0700 (PDT) From: "=?UTF-8?q?Christian=20K=C3=B6nig?=" X-Google-Original-From: =?UTF-8?q?Christian=20K=C3=B6nig?= To: akpm@linux-foundation.org Cc: sumit.semwal@linaro.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 2/2] mm: introduce vma_set_file function Date: Mon, 14 Sep 2020 15:29:20 +0200 Message-Id: <20200914132920.59183-3-christian.koenig@amd.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200914132920.59183-1-christian.koenig@amd.com> References: <20200914132920.59183-1-christian.koenig@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add the new vma_set_file() function to allow changing vma->vm_file with the necessary refcount dance. Signed-off-by: Christian König --- drivers/dma-buf/dma-buf.c | 16 +++++----------- include/linux/mm.h | 2 ++ mm/mmap.c | 16 ++++++++++++++++ 3 files changed, 23 insertions(+), 11 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 1699a8e309ef..672f3525ba74 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -1163,20 +1163,14 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, return -EINVAL; /* readjust the vma */ - get_file(dmabuf->file); - oldfile = vma->vm_file; - vma->vm_file = dmabuf->file; + oldfile = vma_set_file(vma, dmabuf->file); vma->vm_pgoff = pgoff; ret = dmabuf->ops->mmap(dmabuf, vma); - if (ret) { - /* restore old parameters on failure */ - vma->vm_file = oldfile; - fput(dmabuf->file); - } else { - if (oldfile) - fput(oldfile); - } + /* restore old parameters on failure */ + if (ret) + vma_set_file(vma, oldfile); + return ret; } diff --git a/include/linux/mm.h b/include/linux/mm.h index 1983e08f5906..398a6fdaad1e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2688,6 +2688,8 @@ static inline void vma_set_page_prot(struct vm_area_struct *vma) } #endif +struct file *vma_set_file(struct vm_area_struct *vma, struct file *file); + #ifdef CONFIG_NUMA_BALANCING unsigned long change_prot_numa(struct vm_area_struct *vma, unsigned long start, unsigned long end); diff --git a/mm/mmap.c b/mm/mmap.c index 40248d84ad5f..d3c3c510f643 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -136,6 +136,22 @@ void vma_set_page_prot(struct vm_area_struct *vma) WRITE_ONCE(vma->vm_page_prot, vm_page_prot); } +/* + * Change backing file, only valid to use during initial VMA setup. + */ +struct file *vma_set_file(struct vm_area_struct *vma, struct file *file) +{ + if (file) + get_file(file); + + swap(vma->vm_file, file); + + if (file) + fput(file); + + return file; +} + /* * Requires inode->i_mapping->i_mmap_rwsem */ -- 2.17.1