From: Phillip Susi <psusi@cfl.rr.com>
To: Greg KH <gregkh@suse.de>
Cc: linux-kernel@vger.kernel.org
Subject: Re: tty idle time and hooking inode_ops from a chardev
Date: Fri, 16 Dec 2011 14:49:31 -0500 [thread overview]
Message-ID: <4EEBA0CB.1050006@cfl.rr.com> (raw)
In-Reply-To: <20111216183613.GA3612@suse.de>
On 12/16/2011 1:36 PM, Greg KH wrote:
> As you are opening the tty node once, that's when atime is set, right?
> The fact that you keep it open still keeps the atime to the original
> open time, you aren't supposed to check for every single read/write of
> the node once it was opened.
>
> But to be sure, what does POSIX say about this?
Actually it looks like POSIX 4.8 "File Times Update" requires the
timestamps to be updated on every read/write, which is probably why
Linux does that.
So the problem is just the /dev/tty alias having a different inode than
the actual controlling tty. It also makes the output of lsof less
useful, so maybe the real fix is to somehow make opening /dev/tty
actually open the correct tty inode and dentry.
I have a feeling that will require changing /dev/tty from being a
devnode to a symlink to something in /dev/pts.
prev parent reply other threads:[~2011-12-16 19:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-16 16:52 tty idle time and hooking inode_ops from a chardev Phillip Susi
2011-12-16 17:57 ` Greg KH
2011-12-16 18:22 ` Phillip Susi
2011-12-16 18:36 ` Greg KH
2011-12-16 19:09 ` Phillip Susi
2011-12-16 19:49 ` Phillip Susi [this message]
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