From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753153AbaHCVWr (ORCPT ); Sun, 3 Aug 2014 17:22:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:3060 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752071AbaHCVWp (ORCPT ); Sun, 3 Aug 2014 17:22:45 -0400 Date: Sun, 3 Aug 2014 23:20:27 +0200 From: Oleg Nesterov To: "Kirill A. Shutemov" Cc: Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, David Howells , Peter Zijlstra , Sasha Levin , Cyrill Gorcunov , "David S. Miller" , "Kirill A. Shutemov" Subject: [PATCH 4/5] fs/proc/task_mmu.c: introduce the "stable" proc_maps_private->mm Message-ID: <20140803212027.GE13330@redhat.com> References: <1407010227-2269-1-git-send-email-kirill@shutemov.name> <20140803164452.GA14626@redhat.com> <20140803211843.GA13330@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140803211843.GA13330@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 A separate change to simplify the review of the next one. Add the new "mm_struct *mm" member into struct proc_maps_private, it is initialized by proc_maps_open() at "open" time. This obviously means that proc_maps_open() users should additionally do mmdrop() in fop->release(), add the new helper, proc_map_release(). Signed-off-by: Oleg Nesterov --- fs/proc/internal.h | 1 + fs/proc/task_mmu.c | 31 +++++++++++++++++++++++++------ 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/fs/proc/internal.h b/fs/proc/internal.h index ba0c1c1..78784cd 100644 --- a/fs/proc/internal.h +++ b/fs/proc/internal.h @@ -267,6 +267,7 @@ extern int proc_remount(struct super_block *, int *, char *); struct proc_maps_private { struct pid *pid; struct task_struct *task; + struct mm_struct *mm; #ifdef CONFIG_MMU struct vm_area_struct *tail_vma; #endif diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 794aeb6..1cc623d 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -240,9 +240,28 @@ static int proc_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 proc_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 do_maps_open(struct inode *inode, struct file *file, const struct seq_operations *ops) { @@ -398,14 +417,14 @@ const struct file_operations proc_pid_maps_operations = { .open = pid_maps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_private, + .release = proc_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 = proc_map_release, }; /* @@ -680,14 +699,14 @@ const struct file_operations proc_pid_smaps_operations = { .open = pid_smaps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_private, + .release = proc_map_release, }; const struct file_operations proc_tid_smaps_operations = { .open = tid_smaps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_private, + .release = proc_map_release, }; /* @@ -1520,13 +1539,13 @@ const struct file_operations proc_pid_numa_maps_operations = { .open = pid_numa_maps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_private, + .release = proc_map_release, }; const struct file_operations proc_tid_numa_maps_operations = { .open = tid_numa_maps_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release_private, + .release = proc_map_release, }; #endif /* CONFIG_NUMA */ -- 1.5.5.1