From patchwork Tue Jun 15 15:52:52 2010
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Subject: [v2] block: fix physical_block_size calculation
From: Christoph Hellwig <hch@lst.de>
X-Patchwork-Id: 55733
Message-Id: <20100615155252.GB2364@lst.de>
To: qemu-devel@nongnu.org
Date: Tue, 15 Jun 2010 17:52:52 +0200

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++;
     }