[Qemu-devel] [PATCH] block: fix physical_block_size calculation

[Christoph Hellwig]

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 <b...@redhat.com>
Signed-off-by: Christoph Hellwig <h...@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 14:30:00.164034570 +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 / conf->logical_block_size;
+         size > 512;
+        size >>= 1) {
         exp++;
     }