From: Al Viro <viro@ZenIV.linux.org.uk>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Jan Kara <jack@suse.cz>, Christoph Hellwig <hch@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux FS Devel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH 0/4 v3] fs: Remove i_devices from struct inode
Date: Tue, 4 Nov 2014 20:16:21 +0000 [thread overview]
Message-ID: <20141104201620.GL7996@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CALCETrViY8biMs=D9XKAJx-9m5iEEUCbpzmOR2QFVyxcdoczxQ@mail.gmail.com>
On Tue, Nov 04, 2014 at 11:52:22AM -0800, Andy Lutomirski wrote:
> Let me try again, though: what if a chardev inode replaced i_cdev with
> NULL and dropped its kobj reference in iput_final? This would add a
> bit over overhead to things that repeatedly open and close the same
> device node, but I doubt this matters much.
How is it different from what Jan proposed? The whole problem is that
iput_final() is too late. We could clean the reference on close, all
right, and have it looked up again on every open, but I'm not at all sure
that situation with opening/closing cdev is never a hot path, especially with
udev playing silly buggers, etc.
next prev parent reply other threads:[~2014-11-04 20:16 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-04 10:27 [PATCH 0/4 v3] fs: Remove i_devices from struct inode Jan Kara
2014-11-04 10:27 ` [PATCH 1/4] blockdev: Don't use i_devices inode field Jan Kara
2014-11-04 10:27 ` [PATCH 2/4] chardev: Increment cdev reference count when i_cdev references it Jan Kara
2014-11-04 10:27 ` [PATCH 3/4] chardev: Don't use i_devices inode field Jan Kara
2014-11-04 10:27 ` [PATCH 4/4] fs: Remove i_devices list head Jan Kara
2014-11-04 15:39 ` [PATCH 0/4 v3] fs: Remove i_devices from struct inode Al Viro
2014-11-04 19:47 ` Andy Lutomirski
2014-11-04 19:52 ` Andy Lutomirski
2014-11-04 20:16 ` Al Viro [this message]
2014-11-04 20:24 ` Andy Lutomirski
2014-11-04 19:55 ` Jan Kara
2014-11-04 20:14 ` Andy Lutomirski
2014-11-04 20:20 ` Al Viro
2014-11-04 20:25 ` Andy Lutomirski
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