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Date: Sun, 16 May 2010 15:30:22 +0200
From: Christoph Hellwig <hch@lst.de>
Message-ID: <20100516133022.GB27075@lst.de>
References: <1273930259-12694-1-git-send-email-nab@linux-iscsi.org>
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Subject: [Qemu-devel] Re: [PATCH 2/2] [block]: Skip refresh_total_sectors()
	for scsi-generic devices
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To: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Kevin Wolf <kwolf@redhat.com>, kvm-devel <kvm@vger.kernel.org>, qemu-devel <qemu-devel@nongnu.org>, Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@lst.de>, Gerd Hoffmann <kraxel@redhat.com>

On Sat, May 15, 2010 at 06:30:59AM -0700, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> This patch adds a BlockDriverState->sg check in block.c:bdrv_common_open()
> to skip the new refresh_total_sectors() call once we know we are working with
> a scsi-generic device.
> 
> We go ahead and skip this call for scsi-generic devices because
> block/raw-posix.c:raw_getlength() -> lseek() will return -ESPIPE.

How about moving that check into refresh_total_sectors?