From patchwork Tue Sep 25 15:30:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 10614265 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9D41E1803 for ; Tue, 25 Sep 2018 15:30:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 90E752A8AB for ; Tue, 25 Sep 2018 15:30:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 85A222A8A4; Tue, 25 Sep 2018 15:30:43 +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=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 352802A864 for ; Tue, 25 Sep 2018 15:30:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729878AbeIYVia (ORCPT ); Tue, 25 Sep 2018 17:38:30 -0400 Received: from mail-qt1-f194.google.com ([209.85.160.194]:33693 "EHLO mail-qt1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729862AbeIYVi3 (ORCPT ); Tue, 25 Sep 2018 17:38:29 -0400 Received: by mail-qt1-f194.google.com with SMTP id i10-v6so13805731qtp.0 for ; Tue, 25 Sep 2018 08:30:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:in-reply-to:references; bh=ku7/MRL/ppjtTHGZe2O1XF901LokT9maZEyU9FpjnHE=; b=QENpwOrr/7ZhS366ZP7w913/Hs2ElSqyKva/3kYfiaWk0+nhF6n+0Oa0FNzB+IV9Ye w8PDsT3mG1ZBqJSQto0v1fNNqZiiuYsf8CdazEuwY8dEGoeye7fn2Mkgzrzd1pmXKusw ihZdiUq10sVQ4cocO/MxEM+S/6DBh0Z4tjeMK4z44d/zCWr8qs0/nJDyXikVoXRDdTDk mtZ+7pr6nbyNre5aGEML/ZNBB8ndkk8vZSu7Mhd0VOqKcMyDsa5hBcEYJLYdoh4dLmog MdEJGU9LhxBcsHxVKFbrTgk52uT33H2FKS0kYhrbYjBC841r9NXAD4ZgSSGqzActbwAG 2dfw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=ku7/MRL/ppjtTHGZe2O1XF901LokT9maZEyU9FpjnHE=; b=ti/ym6j/QLRtZVmDtoWaVL9VxRiZlhwTt5J1tlX1uWMxfSbFxoee47BFGHS+0lFOGQ BzRs3MccTxzRevQsVTufojo17I1sYe4mY22R334zoab1RyoOIddULWypKl3wqlrcDkrk HSBwGFxlO22UOqCN7l6656Y36dmJQ/iK3e2B/E/mRottnSVFfADcBnBJPHfMww7hQLB9 P31NiYgDEXFx4t4gMZ1TOvlUOa4K34fFxljz2Qa3P5wDtONptHAHWT0GtTKFCzHDG4nk 13aDRW6lhB/R+Lhhbkjriv7IvYHWQa233vwBcXmuKar2/sspCtmnptjzw3HDY+dAzqeG pTGw== X-Gm-Message-State: ABuFfojhRqWhJSSGoP7aoBwzMIxCaT3fUWDzl19KHUdCqqT0iX47Vk4L NPW+a7NA92oTS4yKca976Vdpaw== X-Google-Smtp-Source: ACcGV62u48xuG+u6HnDqHjgjSdJBvYRkbiUdmT4B3A/rajjCC8tIPdq/rTHhk6YGPZQGn6+Y1hSAMw== X-Received: by 2002:a0c:93c1:: with SMTP id g1-v6mr1226748qvg.136.1537889427517; Tue, 25 Sep 2018 08:30:27 -0700 (PDT) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id l16-v6sm1642913qtk.30.2018.09.25.08.30.26 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 25 Sep 2018 08:30:26 -0700 (PDT) From: Josef Bacik To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, linux-btrfs@vger.kernel.org, riel@redhat.com, hannes@cmpxchg.org, tj@kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 7/8] mm: add a flag to indicate we used a cached page Date: Tue, 25 Sep 2018 11:30:10 -0400 Message-Id: <20180925153011.15311-8-josef@toxicpanda.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180925153011.15311-1-josef@toxicpanda.com> References: <20180925153011.15311-1-josef@toxicpanda.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This is preparation for dropping the mmap_sem in page_mkwrite. We need to know if we used our cached page so we can be sure it is the page we already did the page_mkwrite stuff on so we don't have to redo all of that work. Signed-off-by: Josef Bacik --- include/linux/mm.h | 6 +++++- mm/filemap.c | 5 ++++- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 724514be03b2..10a0118f5485 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -318,6 +318,9 @@ extern pgprot_t protection_map[16]; #define FAULT_FLAG_USER 0x40 /* The fault originated in userspace */ #define FAULT_FLAG_REMOTE 0x80 /* faulting for non current tsk/mm */ #define FAULT_FLAG_INSTRUCTION 0x100 /* The fault was during an instruction fetch */ +#define FAULT_FLAG_USED_CACHED 0x200 /* Our vmf->page was from a previous + * loop through the fault handler. + */ #define FAULT_FLAG_TRACE \ { FAULT_FLAG_WRITE, "WRITE" }, \ @@ -328,7 +331,8 @@ extern pgprot_t protection_map[16]; { FAULT_FLAG_TRIED, "TRIED" }, \ { FAULT_FLAG_USER, "USER" }, \ { FAULT_FLAG_REMOTE, "REMOTE" }, \ - { FAULT_FLAG_INSTRUCTION, "INSTRUCTION" } + { FAULT_FLAG_INSTRUCTION, "INSTRUCTION" }, \ + { FAULT_FLAG_USED_CACHED, "USED_CACHED" } /* * vm_fault is filled by the the pagefault handler and passed to the vma's diff --git a/mm/filemap.c b/mm/filemap.c index 49b35293fa95..75a8b252814a 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2556,6 +2556,7 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) if (cached_page->mapping == mapping && cached_page->index == offset) { page = cached_page; + vmf->flags |= FAULT_FLAG_USED_CACHED; goto have_cached_page; } unlock_page(cached_page); @@ -2618,8 +2619,10 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) * We have a locked page in the page cache, now we need to check * that it's up-to-date. If not, it is going to be due to an error. */ - if (unlikely(!PageUptodate(page))) + if (unlikely(!PageUptodate(page))) { + vmf->flags &= ~(FAULT_FLAG_USED_CACHED); goto page_not_uptodate; + } /* * Found the page and have a reference on it.