From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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> In-Reply-To: <20151209053209.GV20997@ZenIV.linux.org.uk> References: <20151209053209.GV20997@ZenIV.linux.org.uk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: 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); } -- 2.1.4