From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id D8D116B007B for ; Tue, 5 Oct 2010 03:53:58 -0400 (EDT) Received: from kpbe11.cbf.corp.google.com (kpbe11.cbf.corp.google.com [172.25.105.75]) by smtp-out.google.com with ESMTP id o957ruLU014266 for ; Tue, 5 Oct 2010 00:53:56 -0700 Received: from pvg2 (pvg2.prod.google.com [10.241.210.130]) by kpbe11.cbf.corp.google.com with ESMTP id o957rtai002880 for ; Tue, 5 Oct 2010 00:53:55 -0700 Received: by pvg2 with SMTP id 2so1539080pvg.19 for ; Tue, 05 Oct 2010 00:53:55 -0700 (PDT) From: Michel Lespinasse 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> In-Reply-To: <1286265215-9025-1-git-send-email-walken@google.com> References: <1286265215-9025-1-git-send-email-walken@google.com> Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org, Linus Torvalds , Ying Han Cc: linux-kernel@vger.kernel.org, Andrew Morton , Rik van Riel , Nick Piggin , Peter Zijlstra List-ID: 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org