From patchwork Tue Sep 27 16:08:16 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 9352255 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E1924600CB for ; Tue, 27 Sep 2016 16:08:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D3019286CD for ; Tue, 27 Sep 2016 16:08:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C7B4728A05; Tue, 27 Sep 2016 16:08:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=2.0 tests=BAYES_05, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 72A89286CD for ; Tue, 27 Sep 2016 16:08:47 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 33C4E1A1E7E; Tue, 27 Sep 2016 09:08:39 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id D8C851A1E3D for ; Tue, 27 Sep 2016 09:08:35 -0700 (PDT) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 7F78275021; Tue, 27 Sep 2016 16:08:32 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 0EDFA1E110B; Tue, 27 Sep 2016 18:08:31 +0200 (CEST) From: Jan Kara To: linux-mm@kvack.org Subject: [PATCH 12/20] mm: Factor out common parts of write fault handling Date: Tue, 27 Sep 2016 18:08:16 +0200 Message-Id: <1474992504-20133-13-git-send-email-jack@suse.cz> X-Mailer: git-send-email 2.6.6 In-Reply-To: <1474992504-20133-1-git-send-email-jack@suse.cz> References: <1474992504-20133-1-git-send-email-jack@suse.cz> X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Kara , linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, "Kirill A. Shutemov" MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP Currently we duplicate handling of shared write faults in wp_page_reuse() and do_shared_fault(). Factor them out into a common function. Signed-off-by: Jan Kara Reviewed-by: Ross Zwisler --- mm/memory.c | 78 +++++++++++++++++++++++++++++-------------------------------- 1 file changed, 37 insertions(+), 41 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 63d9c1a54caf..0643b3b5a12a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2063,6 +2063,41 @@ static int do_page_mkwrite(struct vm_area_struct *vma, struct page *page, } /* + * Handle dirtying of a page in shared file mapping on a write fault. + * + * The function expects the page to be locked and unlocks it. + */ +static void fault_dirty_shared_page(struct vm_area_struct *vma, + struct page *page) +{ + struct address_space *mapping; + bool dirtied; + bool page_mkwrite = vma->vm_ops->page_mkwrite; + + dirtied = set_page_dirty(page); + VM_BUG_ON_PAGE(PageAnon(page), page); + /* + * Take a local copy of the address_space - page.mapping may be zeroed + * by truncate after unlock_page(). The address_space itself remains + * pinned by vma->vm_file's reference. We rely on unlock_page()'s + * release semantics to prevent the compiler from undoing this copying. + */ + mapping = page_rmapping(page); + unlock_page(page); + + if ((dirtied || page_mkwrite) && mapping) { + /* + * Some device drivers do not set page.mapping + * but still dirty their pages + */ + balance_dirty_pages_ratelimited(mapping); + } + + if (!page_mkwrite) + file_update_time(vma->vm_file); +} + +/* * Handle write page faults for pages that can be reused in the current vma * * This can happen either due to the mapping being with the VM_SHARED flag, @@ -2092,28 +2127,11 @@ static inline int wp_page_reuse(struct vm_fault *vmf, struct page *page, pte_unmap_unlock(vmf->pte, vmf->ptl); if (dirty_shared) { - struct address_space *mapping; - int dirtied; - if (!page_mkwrite) lock_page(page); - dirtied = set_page_dirty(page); - VM_BUG_ON_PAGE(PageAnon(page), page); - mapping = page->mapping; - unlock_page(page); + fault_dirty_shared_page(vma, page); put_page(page); - - if ((dirtied || page_mkwrite) && mapping) { - /* - * Some device drivers do not set page.mapping - * but still dirty their pages - */ - balance_dirty_pages_ratelimited(mapping); - } - - if (!page_mkwrite) - file_update_time(vma->vm_file); } return VM_FAULT_WRITE; @@ -3256,8 +3274,6 @@ uncharge_out: static int do_shared_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; - struct address_space *mapping; - int dirtied = 0; int ret, tmp; ret = __do_fault(vmf); @@ -3286,27 +3302,7 @@ static int do_shared_fault(struct vm_fault *vmf) return ret; } - if (set_page_dirty(vmf->page)) - dirtied = 1; - /* - * Take a local copy of the address_space - page.mapping may be zeroed - * by truncate after unlock_page(). The address_space itself remains - * pinned by vma->vm_file's reference. We rely on unlock_page()'s - * release semantics to prevent the compiler from undoing this copying. - */ - mapping = page_rmapping(vmf->page); - unlock_page(vmf->page); - if ((dirtied || vma->vm_ops->page_mkwrite) && mapping) { - /* - * Some device drivers do not set page.mapping but still - * dirty their pages - */ - balance_dirty_pages_ratelimited(mapping); - } - - if (!vma->vm_ops->page_mkwrite) - file_update_time(vma->vm_file); - + fault_dirty_shared_page(vma, vmf->page); return ret; }