From mboxrd@z Thu Jan  1 00:00:00 1970
From: Peter Staubach <staubach@redhat.com>
Subject: Re: [PATCH] fix posix lock on NFS
Date: Tue, 03 Jan 2006 14:39:24 -0500
Message-ID: <43BAD2EC.2030807@redhat.com>
References: <20051222.132454.1025208517.masano@tnes.nec.co.jp>
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Cc: trond.myklebust@fys.uio.no, matthew@wil.cx,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
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To: ASANO Masahiro <masano@tnes.nec.co.jp>
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ASANO Masahiro wrote:

>---
>
>--- linux-2.6.15-rc6/fs/nfs/file.c.orig	2005-12-21 21:30:14.000000000 +0900
>+++ linux-2.6.15-rc6/fs/nfs/file.c	2005-12-21 21:42:16.000000000 +0900
>@@ -524,7 +524,8 @@ static int nfs_lock(struct file *filp, i
> 		return -EINVAL;
> 
> 	/* No mandatory locks over NFS */
>-	if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
>+	if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
>+	    fl->fl_type != F_UNLCK)
> 		return -ENOLCK;
> 
> 	if (IS_GETLK(cmd))
>

Just out of curiosity, what is this if() statement intended to protect?
For locking purposes, why would the client care if the file has the
mandatory lock bits set?

    Thanx...

       ps