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From: Kay Sievers <kay.sievers@vrfy.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Kyle Moffett <kyle@moffetthome.net>,
	Pantelis Koukousoulas <pktoss@gmail.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: How to tell whether a struct file is held by a process?
Date: Fri, 22 May 2009 17:21:17 +0200	[thread overview]
Message-ID: <ac3eb2510905220821n629314c3tb113802f52abc67c@mail.gmail.com> (raw)
In-Reply-To: <Pine.LNX.4.44L0.0905221051350.3006-100000@iolanthe.rowland.org>

On Fri, May 22, 2009 at 17:12, Alan Stern <stern@rowland.harvard.edu> wrote:
> Anyway, enumeration isn't the problem.  The real problem has two parts:
>
>        Automatic probing and binding of kernel drivers, including
>        selection and installation of a configuration (this really
>        _does_ mess up virtualization).
>
>        The fact that a window exists immediately after the
>        registration of a newly-detected device before a user
>        process can lock the device file.  During this window,
>        other processes could open the file.
>
> The second part can be solved (among cooperating processes) by use of
> port-lock files, with no kernel involvement.  The first part does
> require a kernel interface of some sort, but it wouldn't have to be
> complicated.  The mere fact that a port-lock file was open could be
> enough to prevent automatic configuration, probing, and binding.
>
> Does this seem like reasonable approach?

Would releasing the "lock" trigger a kernel-driver-binding call?

The lock will always lock all devices of a specific hub?

Thanks,
Kay

  parent reply	other threads:[~2009-05-22 15:21 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-19 16:57 Alan Stern
2009-05-21  9:52 ` Al Viro
2009-05-21 14:06   ` Alan Stern
2009-05-21 21:07     ` Kay Sievers
2009-05-21 21:27       ` Alan Stern
2009-05-22 13:30         ` Pantelis Koukousoulas
2009-05-22 13:38           ` Oliver Neukum
2009-05-22 13:43           ` Alan Cox
2009-05-22 13:52             ` Pantelis Koukousoulas
2009-05-22 14:12               ` Alan Cox
2009-05-22 14:29                 ` Pantelis Koukousoulas
2009-05-21 22:14       ` Alan Cox
2009-05-22  1:28         ` Kyle Moffett
2009-05-22  9:53           ` Alan Cox
2009-05-22 15:12             ` Alan Stern
2009-05-22 15:20               ` Alan Cox
2009-05-22 16:04                 ` Alan Stern
2009-05-22 16:23                   ` Pantelis Koukousoulas
2009-05-22 18:19                     ` Alan Stern
2009-05-22 15:21               ` Kay Sievers [this message]
2009-05-22 15:54                 ` Alan Stern
2009-05-22 18:24                   ` Kay Sievers
2009-05-22 18:48                     ` Pantelis Koukousoulas
2009-05-22 19:31                     ` Alan Stern
2009-05-22 21:54                       ` Kay Sievers
2009-05-22 22:07                         ` Alan Stern
2009-05-23 22:47                           ` Kay Sievers
2009-05-22  8:36         ` Oliver Neukum
2009-05-21 22:22     ` Alan Cox
2009-05-22 12:26     ` Oliver Neukum

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