From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932224Ab0JEHyI (ORCPT ); Tue, 5 Oct 2010 03:54:08 -0400 Received: from smtp-out.google.com ([74.125.121.35]:20143 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757885Ab0JEHyF (ORCPT ); Tue, 5 Oct 2010 03:54:05 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=XORvb6gkFWWIBTOMF1UVPBeMJDNmxuotiUDqmCHfsbSn3P1adrk/ZLJaU8RGeEgsmy UMMjDLdbtUy0A9OCLhiA== From: Michel Lespinasse To: linux-mm@kvack.org, Linus Torvalds , Ying Han Cc: linux-kernel@vger.kernel.org, Andrew Morton , Rik van Riel , Nick Piggin , Peter Zijlstra Subject: [PATCH 1/3] filemap_fault: unique path for locking page Date: Tue, 5 Oct 2010 00:53:33 -0700 Message-Id: <1286265215-9025-2-git-send-email-walken@google.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1286265215-9025-1-git-send-email-walken@google.com> References: <1286265215-9025-1-git-send-email-walken@google.com> X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This change introduces a single location where filemap_fault() locks the desired page. There used to be two such places, depending if the initial find_get_page() was successful or not. Signed-off-by: Michel Lespinasse --- mm/filemap.c | 20 +++++++++++--------- 1 files changed, 11 insertions(+), 9 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 3d4df44..8ed709a 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1539,25 +1539,27 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) * waiting for the lock. */ do_async_mmap_readahead(vma, ra, file, page, offset); - lock_page(page); - - /* Did it get truncated? */ - if (unlikely(page->mapping != mapping)) { - unlock_page(page); - put_page(page); - goto no_cached_page; - } } else { /* No page in the page cache at all */ do_sync_mmap_readahead(vma, ra, file, offset); count_vm_event(PGMAJFAULT); ret = VM_FAULT_MAJOR; retry_find: - page = find_lock_page(mapping, offset); + page = find_get_page(mapping, offset); if (!page) goto no_cached_page; } + lock_page(page); + + /* Did it get truncated? */ + if (unlikely(page->mapping != mapping)) { + unlock_page(page); + put_page(page); + goto retry_find; + } + VM_BUG_ON(page->index != offset); + /* * 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. -- 1.7.1