From patchwork Wed Dec 9 05:34:53 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 7804731 Return-Path: X-Original-To: patchwork-linux-fsdevel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 589A9BEEE5 for ; Wed, 9 Dec 2015 05:38:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 93436204AE for ; Wed, 9 Dec 2015 05:38:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8C578204C9 for ; Wed, 9 Dec 2015 05:38:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751451AbbLIFhp (ORCPT ); Wed, 9 Dec 2015 00:37:45 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:46494 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751682AbbLIFe5 (ORCPT ); Wed, 9 Dec 2015 00:34:57 -0500 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.76 #1 (Red Hat Linux)) id 1a6XOy-0005Ls-D3; Wed, 09 Dec 2015 05:34:56 +0000 From: Al Viro To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Neil Brown , linux-fsdevel@vger.kernel.org Subject: [PATCH v2 09/11] teach shmem_get_link() to work in RCU mode Date: Wed, 9 Dec 2015 05:34:53 +0000 Message-Id: <1449639295-20512-9-git-send-email-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <20151209053209.GV20997@ZenIV.linux.org.uk> References: <20151209053209.GV20997@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Al Viro Signed-off-by: Al Viro --- mm/shmem.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 684dbc3..0605716 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2501,12 +2501,20 @@ static const char *shmem_get_link(struct dentry *dentry, { struct page *page = NULL; int error; - if (!dentry) - return ERR_PTR(-ECHILD); - error = shmem_getpage(inode, 0, &page, SGP_READ, NULL); - if (error) - return ERR_PTR(error); - unlock_page(page); + if (!dentry) { + page = find_get_page(inode->i_mapping, 0); + if (!page) + return ERR_PTR(-ECHILD); + if (!PageUptodate(page)) { + put_page(page); + return ERR_PTR(-ECHILD); + } + } else { + error = shmem_getpage(inode, 0, &page, SGP_READ, NULL); + if (error) + return ERR_PTR(error); + unlock_page(page); + } *cookie = page; return page_address(page); }