From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754550AbaHKRDh (ORCPT ); Mon, 11 Aug 2014 13:03:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11947 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754499AbaHKRDC (ORCPT ); Mon, 11 Aug 2014 13:03:02 -0400 Date: Mon, 11 Aug 2014 19:00:35 +0200 From: Oleg Nesterov To: Andrew Morton , Greg Ungerer Cc: Alexander Viro , Cyrill Gorcunov , David Howells , "David S. Miller" , "Eric W. Biederman" , "Kirill A. Shutemov" , "Kirill A. Shutemov" , Peter Zijlstra , Sasha Levin , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/3] fs/proc/task_nommu.c: shift mm_access() from m_start() to proc_maps_open() Message-ID: <20140811170035.GA24800@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140811170008.GA24629@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Copy-and-paste the changes from "fs/proc/task_mmu.c: shift mm_access() from m_start() to proc_maps_open()" into task_nommu.c. Change maps_open() to initialize priv->mm using proc_mem_open(), m_start() can rely on atomic_inc_not_zero(mm_users) like task_mmu.c does. Signed-off-by: Oleg Nesterov --- fs/proc/task_nommu.c | 29 ++++++++++++++++++++++++----- 1 files changed, 24 insertions(+), 5 deletions(-) diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index c12eab3..003f2be 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -216,11 +216,11 @@ static void *m_start(struct seq_file *m, loff_t *pos) if (!priv->task) return ERR_PTR(-ESRCH); - mm = mm_access(priv->task, PTRACE_MODE_READ); - if (!mm || IS_ERR(mm)) { + mm = priv->mm; + if (!mm || !atomic_inc_not_zero(&mm->mm_users)) { put_task_struct(priv->task); priv->task = NULL; - return mm; + return NULL; } down_read(&mm->mmap_sem); @@ -274,9 +274,28 @@ static int maps_open(struct inode *inode, struct file *file, return -ENOMEM; priv->pid = proc_pid(inode); + priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); + if (IS_ERR(priv->mm)) { + int err = PTR_ERR(priv->mm); + seq_release_private(inode, file); + return err; + } + return 0; } + +static int map_release(struct inode *inode, struct file *file) +{ + struct seq_file *seq = file->private_data; + struct proc_maps_private *priv = seq->private; + + if (priv->mm) + mmdrop(priv->mm); + + return seq_release_private(inode, file); +} + static int pid_maps_open(struct inode *inode, struct file *file) { return maps_open(inode, file, &proc_pid_maps_ops); @@ -291,13 +310,13 @@ const struct file_operations proc_pid_maps_operations = { .open = pid_maps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_private, + .release = map_release, }; const struct file_operations proc_tid_maps_operations = { .open = tid_maps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_private, + .release = map_release, }; -- 1.5.5.1