From: "Joseph D. Wagner" <theman@josephdwagner.info>
To: Jamie Lokier <jamie@shareable.org>, Nikita Danilov <Nikita@Namesys.COM>
Subject: Re: [PATCH] fs/locks.c fcntl_setlease did not check if a file was opened for writing before granting a read lease
Date: Thu, 27 Nov 2003 14:49:51 +0600
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Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
       "'Matthew Wilcox'" <willy@debian.org>
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>> But I THINK this is how a patch would fix the problem, in theory.

> Sorry, it won't.
...
> To detect if anyone has the file open for writing, you'll a new count
> field which keeps track of writer references.  Something like this:
>
>        if ((arg == F_RDLCK)
>            && ((atomic_read(&inode->i_writer_count) != 0)))
>
> You'll also need to modify all the places where that needs to be
> maintained.

Well, dang it all.  Why didn't they guy who implemented leasing in the first 
place bother to do it right the first time?

I don't have the time or technical expertise in kernel development to go 
through all that.  Somebody else is going to have to pick up his slack.

Joseph D. Wagner

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