From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932709AbbKQXBu (ORCPT ); Tue, 17 Nov 2015 18:01:50 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:54386 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754974AbbKQXAs (ORCPT ); Tue, 17 Nov 2015 18:00:48 -0500 From: Al Viro To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Neil Brown , linux-fsdevel@vger.kernel.org Subject: [PATCH 09/10] teach shmem_get_link() to work in RCU mode Date: Tue, 17 Nov 2015 23:00:45 +0000 Message-Id: <1447801246-24588-9-git-send-email-viro@ZenIV.linux.org.uk> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <20151117225752.GZ22011@ZenIV.linux.org.uk> References: <20151117225752.GZ22011@ZenIV.linux.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 e8220cf..e1ea5b5 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); } -- 2.1.4