From 1e297c323590d3deae46e566956cc4351e2aa5da Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 15 Jun 2010 17:52:52 +0200
Subject: [PATCH] block: fix physical_block_size calculation

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>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block_int.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/block_int.h b/block_int.h
index e3bfd192a..b64a0095f 100644
--- a/block_int.h
+++ b/block_int.h
@@ -224,7 +224,9 @@ static inline unsigned int get_physical_block_exp(BlockConf *conf)
 {
     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++;
     }
 
-- 
2.39.2