From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marco Stornelli <marco.stornelli@gmail.com>
Subject: Re: [PATCH 1/7] BTRFS: Fix lseek return value for error
Date: Sun, 18 Sep 2011 10:42:37 +0200
Message-ID: <4E75AEFD.105@gmail.com>
References: <1316128013-21980-1-git-send-email-andi@firstfloor.org> <1316128013-21980-2-git-send-email-andi@firstfloor.org> <20110916154815.GA27150@infradead.org> <4E7439EB.7080100@oracle.com> <41C7FF67-8658-4E7F-BB50-E9AAEA1F755C@dilger.ca> <20110918014608.GA16198@alboin.amr.corp.intel.com> <4E759DE5.3020907@oracle.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Cc: Andi Kleen <ak@linux.intel.com>,
	Andreas Dilger <adilger@dilger.ca>,
	Christoph Hellwig <hch@infradead.org>,
	Andi Kleen <andi@firstfloor.org>,
	"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
To: jeff.liu@oracle.com
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <4E759DE5.3020907@oracle.com>
Sender: linux-kernel-owner@vger.kernel.org
List-Id: linux-fsdevel.vger.kernel.org

Il 18/09/2011 09:29, Jeff Liu ha scritto:
> Hi Andreas and Andi,
>
> Thanks for your comments.
>
> On 09/18/2011 09:46 AM, Andi Kleen wrote:
>
>>>> with an additional improvement if the offset is larger or equal to the
>>>> file size, return -ENXIO in directly:
>>>>
>>>>                 if (offset>= inode->i_size) {
>>>>                         mutex_unlock(&inode->i_mutex);
>>>>                         return -ENXIO;
>>>>                 }
>>>
>>> Except that is wrong, because it would then be impossible to write sparse files.
>
> Per my tryout, except that, if the offset>= source file size, call
> lseek(fd, offset, SEEK_DATA/SEEK_HOLE) against Btrfs will always return
> the total file size rather than -ENXIO.  however, our desired result it
> -ENXIO in this case, Am I right?
>

Yes, ENXIO should be the operation result.