From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=37496 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1OOYZB-0005qL-5p
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 12:00:50 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69)
	(envelope-from <hch@lst.de>) id 1OOYRZ-0000Qr-F9
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 11:52:54 -0400
Received: from verein.lst.de ([213.95.11.210]:60556)
	by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from <hch@lst.de>)
	id 1OOYRZ-0000Qf-3d
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 11:52:53 -0400
Received: from verein.lst.de (localhost [127.0.0.1])
	by verein.lst.de (8.12.3/8.12.3/Debian-7.1) with ESMTP id
	o5FFqqXt002469
	(version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO)
	for <qemu-devel@nongnu.org>; Tue, 15 Jun 2010 17:52:52 +0200
Received: (from hch@localhost)
	by verein.lst.de (8.12.3/8.12.3/Debian-7.2) id o5FFqqUn002468
	for qemu-devel@nongnu.org; Tue, 15 Jun 2010 17:52:52 +0200
Date: Tue, 15 Jun 2010 17:52:52 +0200
From: Christoph Hellwig <hch@lst.de>
Message-ID: <20100615155252.GB2364@lst.de>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Subject: [Qemu-devel] [PATCH v2] block: fix physical_block_size calculation
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: qemu-devel@nongnu.org

Both SCSI and virtio expect the physical block size relative to the
logical block size.  So get the factor first before calculating the
log2.  

Reported-by: Mike Cao <bcao@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: qemu/block_int.h
===================================================================
--- qemu.orig/block_int.h	2010-06-15 14:29:42.593012221 +0200
+++ qemu/block_int.h	2010-06-15 17:48:55.428255620 +0200
@@ -223,7 +223,9 @@ static inline unsigned int get_physical_
 {
     unsigned int exp = 0, size;
 
-    for (size = conf->physical_block_size; size > 512; size >>= 1) {
+    for (size = conf->physical_block_size;
+    	 size > conf->logical_block_size;
+	 size >>= 1) {
         exp++;
     }