From: Alan Stern <stern@rowland.harvard.edu>
To: Greg KH <greg@kroah.com>
Cc: Kernel development list <linux-kernel@vger.kernel.org>,
Patrick Mochel <mochel@digitalimplant.org>
Subject: Re: Inconsistency in sysfs behavior?
Date: Wed, 7 Jan 2004 17:24:08 -0500 (EST) [thread overview]
Message-ID: <Pine.LNX.4.44L0.0401071712550.1589-100000@ida.rowland.org> (raw)
In-Reply-To: <20040107215624.GC1083@kroah.com>
On Wed, 7 Jan 2004, Greg KH wrote:
> On Wed, Jan 07, 2004 at 04:50:24PM -0500, Alan Stern wrote:
> >
> > I had in mind approaching this the opposite way. Instead of trying to
> > make open directories also pin a kobject, why not make open attribute
> > files not pin them?
> >
> > It shouldn't be hard to avoid any errors; in fact I had a patch from some
> > time ago that would do the trick (although in a hacked-up kind of way).
> > The main idea is to return -ENXIO instead of calling the show()/store()
> > routines once the attribute has been removed.
>
> And you can do this without adding another lock, race free?
I used dentry->d_inode->i_sem. While I'm not very familiar with the ins
and outs of the filesystem code, that ought to be safe enough.
The real problem was finding a way to indicate that the file was
disconnected from its kobject. I did that by setting
dentry->d_inode->i_mode to 0. (I didn't want to erase dentry->d_fsdata
for fear that it might be needed somewhere else.) That's definitely not a
good way; it was intended only for my proof-of-principle. No doubt
someone else could do a much better job.
Alan Stern
next prev parent reply other threads:[~2004-01-07 22:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-01-07 15:48 Inconsistency in sysfs behavior? Alan Stern
2004-01-07 17:27 ` Greg KH
2004-01-07 21:50 ` Alan Stern
2004-01-07 21:56 ` Greg KH
2004-01-07 22:24 ` Alan Stern [this message]
2004-01-07 22:34 ` Greg KH
2004-01-08 10:32 ` Maneesh Soni
2004-01-08 20:19 ` Greg KH
2004-01-09 4:56 ` Maneesh Soni
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