From mboxrd@z Thu Jan  1 00:00:00 1970
From: ebiederm@xmission.com (Eric W. Biederman)
Subject: Re: [RFC][PATCH 2/3] vfs: Add a function to lazily unmount all mounts from any dentry.
Date: Sun, 06 Oct 2013 23:15:08 -0700
Message-ID: <87y5658v4j.fsf@xmission.com>
References: <CAJfpegsxgnSRUW-E5HM3uT5QfGyUtn_v=i4Ppkkkutp34287AA@mail.gmail.com>
	<87a9kkax0j.fsf@xmission.com>
	<CAJfpeguv+7giYNpAuXE9Ja_9BEwB0-fZBVgRSeVqpzSXgQYZ6Q@mail.gmail.com>
	<8761v7h2pt.fsf@tw-ebiederman.twitter.com>
	<CAJfpegtT7y-1HhbEVAMKkdQugTG_w7G_epGtQHGvQLpcZB5FVA@mail.gmail.com>
	<87li281wx6.fsf_-_@xmission.com> <87a9io1wu1.fsf_-_@xmission.com>
	<20131007042225.GA10284@mail.hallyn.com>
Mime-Version: 1.0
Content-Type: text/plain
Cc: Miklos Szeredi <miklos@szeredi.hu>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Linux-Fsdevel <linux-fsdevel@vger.kernel.org>,
	Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andy Lutomirski <luto@amacapital.net>,
	Rob Landley <rob@landley.net>,
	Linus Torvalds <torvalds@linux-foundation.org>
To: "Serge E. Hallyn" <serge@hallyn.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20131007042225.GA10284@mail.hallyn.com> (Serge E. Hallyn's
	message of "Mon, 7 Oct 2013 04:22:26 +0000")
Sender: linux-kernel-owner@vger.kernel.org
List-Id: linux-fsdevel.vger.kernel.org

"Serge E. Hallyn" <serge@hallyn.com> writes:

> Quoting Eric W. Biederman (ebiederm@xmission.com):
>> 
>> Signed-off-by: Eric W. Biederman <ebiederman@twitter.com>
>> ---
>>  fs/mount.h     |    1 +
>>  fs/namespace.c |   24 ++++++++++++++++++++++++
>>  2 files changed, 25 insertions(+), 0 deletions(-)
>> 
>> diff --git a/fs/mount.h b/fs/mount.h
>> index e4342b8dfab1..7a6a2bb3f290 100644
>> --- a/fs/mount.h
>> +++ b/fs/mount.h
>> @@ -79,6 +79,7 @@ static inline int is_mounted(struct vfsmount *mnt)
>>  }
>>  
>>  extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
>> +extern void detach_mounts(struct dentry *dentry);
>>  
>>  static inline void get_mnt_ns(struct mnt_namespace *ns)
>>  {
>> diff --git a/fs/namespace.c b/fs/namespace.c
>> index d092964fe7f9..8eaee0c14fdb 100644
>> --- a/fs/namespace.c
>> +++ b/fs/namespace.c
>> @@ -1294,6 +1294,30 @@ static int do_umount(struct mount *mnt, int flags)
>>  	return retval;
>>  }
>>  
>> +void detach_mounts(struct dentry *dentry)
>> +{
>> +	struct mount *mnt, *next;
>> +	struct mountpoint *mp;
>> +
>> +	namespace_lock();
>> +	if (!d_mountpoint(dentry)) {
>> +		namespace_unlock();
>> +		return;
>> +	}
>> +	mp = new_mountpoint(dentry);
>> +	if (IS_ERR(mp)) {
>
> 	namespace_unlock();

Good catch.  Thank you.

Eric