From patchwork Thu Mar 9 18:55:55 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 9614053 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0B18060417 for ; Thu, 9 Mar 2017 19:03:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0AB41223A6 for ; Thu, 9 Mar 2017 19:03:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F3C362866F; Thu, 9 Mar 2017 19:03:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A4C96223A6 for ; Thu, 9 Mar 2017 19:03:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754906AbdCIS4I (ORCPT ); Thu, 9 Mar 2017 13:56:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54638 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754618AbdCIS4F (ORCPT ); Thu, 9 Mar 2017 13:56:05 -0500 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6C3B33A7680; Thu, 9 Mar 2017 18:55:59 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-66.rdu2.redhat.com [10.10.120.66] (may be forged)) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v29Itv6W031211; Thu, 9 Mar 2017 13:55:58 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 02/27] afs: Fix page overput in afs_fill_page() From: David Howells To: viro@ZenIV.linux.org.uk Cc: Marc Dionne , dhowells@redhat.com, linux-fsdevel@vger.kernel.org, linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org Date: Thu, 09 Mar 2017 18:55:55 +0000 Message-ID: <148908575583.16794.5285608492468338019.stgit@warthog.procyon.org.uk> In-Reply-To: <148908574888.16794.14109877851518811944.stgit@warthog.procyon.org.uk> References: <148908574888.16794.14109877851518811944.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 09 Mar 2017 18:55:59 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP afs_fill_page() loads the page it wants to fill into the afs_read request without incrementing its refcount - but then calls afs_put_read() to clean up afterwards, which then releases a ref on the page. Fix this by getting a ref on the page before calling afs_vnode_fetch_data(). This causes sync after a write to hang in afs_writepages_region() because find_get_pages_tag() gets confused and doesn't return. Fixes: 196ee9cd2d04 ("afs: Make afs_fs_fetch_data() take a list of pages") Reported-by: Marc Dionne Signed-off-by: David Howells Tested-by: Marc Dionne --- fs/afs/write.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/afs/write.c b/fs/afs/write.c index e919e64cd4e0..3ac52f6a96ff 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -101,6 +101,7 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key, req->pos = pos; req->nr_pages = 1; req->pages[0] = page; + get_page(page); i_size = i_size_read(&vnode->vfs_inode); if (pos + PAGE_SIZE > i_size)