Message-ID: <53568529.2030103@panasas.com>
Date: Tue, 22 Apr 2014 18:05:13 +0300
From: Boaz Harrosh <bharrosh@panasas.com>
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To: Jeff Layton <jlayton@redhat.com>
CC: <linux-fsdevel@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <samba-technical@lists.samba.org>,
        Ganesha NFS List <nfs-ganesha-devel@lists.sourceforge.net>,
        libc-alpha <libc-alpha@sourceware.org>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        Christoph Hellwig <hch@infradead.org>,
        "Carlos O'Donell" <carlos@redhat.com>,
        Stefan Metzmacher <metze@samba.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Frank Filz <ffilzlnx@mindspring.com>, "Theodore Ts'o" <tytso@mit.edu>
Subject: Re: [PATCH] locks: rename file-private locks to "open file description
 locks"
References: <1398169383-10743-1-git-send-email-jlayton@redhat.com>	<5356808B.3040303@gmail.com> <20140422105520.7b09eda5@tlielax.poochiereds.net>
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On 04/22/2014 05:55 PM, Jeff Layton wrote:
> On Tue, 22 Apr 2014 17:45:31 +0300
> Boaz Harrosh <openosd@gmail.com> wrote:
> 
> 
> There's a big difference between the descriptor and the description.
> 
> The numerical value you get back from something like open() is a file
> descriptor. 

Ha OK sorry I thought that was a file-handle I think in FBSD they
call it that. I guess file-handle is the NFS thing.

I guess the most common name for those is file-No, fn in
code

> The thing that that value points to internally in the
> kernel is the file description. 

I did not know that and I completely interchanged these two.
In Kernel this is called plain "struct file" so I've never
seen this name used before.

OK Now it is clear

> It's very important that we do not
> conflate the two here as these locks are associated with the file
> description and not the file descriptor.
> 

Sure you are right.

> The best way to illustrate this is the interaction with dup() -- see
> the LWN article on these for a complete overview.
> 

I know the difference very well only I got the names mixed

Thanks
Boaz

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