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Date: Tue, 1 Dec 2009 13:52:25 -0500
From: tytso@mit.edu
To: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Amerigo Wang <amwang@redhat.com>, linux-kernel@vger.kernel.org,
       Alexander Viro <viro@zeniv.linux.org.uk>,
       Jens Axboe <jens.axboe@oracle.com>, Nick Piggin <npiggin@suse.de>,
       linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org
Subject: Re: [Patch] fs: remove a useless BUG()
Message-ID: <20091201185225.GB6278@thunk.org>
Mail-Followup-To: tytso@mit.edu, Marcin Slusarz <marcin.slusarz@gmail.com>,
	Amerigo Wang <amwang@redhat.com>, linux-kernel@vger.kernel.org,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Jens Axboe <jens.axboe@oracle.com>, Nick Piggin <npiggin@suse.de>,
	linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org
References: <20091201023714.3863.92566.sendpatchset@localhost.localdomain>
 <20091201165440.GA2688@joi.lan>
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On Tue, Dec 01, 2009 at 05:55:11PM +0100, Marcin Slusarz wrote:
> On Mon, Nov 30, 2009 at 09:34:14PM -0500, Amerigo Wang wrote:
> > This BUG() is suspicious, it makes its following statements
> > unreachable, 
> only when CONFIG_BUG=y

Which is true for all kernels except for the very rare embedded case.

> > and it seems to be useless, since the caller
> > of this function already handles the failure properly.
> because this function can return NULL in other codepath
> 
> > Remove it.
> I don't know why this BUG() is there (and maybe it's not really
> needed), but your rationale is wrong.

Your reply is a bit snarky, IMHO.  It might have been nicer and more
courteous if you had bothered to take a closer look at the patch
before firing off a reply.

In fact, it's good to avoid BUG() if at all possible, especially if it
can happen in the normally course of events --- such as running out of
memory.  Having code which triggers an BUG in an low memory situation
is very bad form.

Looks good to me.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

							- Ted

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