From: Anthony PERARD <anthony.perard@citrix.com>
Date: Fri, 13 Apr 2012 17:18:56 +0000 (+0000)
Subject: Xen, mapcache: Fix the compute of the size of bucket.
X-Git-Tag: qemu-xen-4.2.0~25
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=0ec445db3137e501e758a50d64e9c2b39d23a6b6;p=qemu-upstream-4.2-testing.git

Xen, mapcache: Fix the compute of the size of bucket.

Because the size of a mapping is wrong when there is an offset and a
size >= bucket_size.

Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---

diff --git a/xen-mapcache.c b/xen-mapcache.c
index d5f52b2cb..eade81632 100644
--- a/xen-mapcache.c
+++ b/xen-mapcache.c
@@ -214,12 +214,14 @@ tryagain:
     }
 
     /* size is always a multiple of MCACHE_BUCKET_SIZE */
-    if ((address_offset + (__size % MCACHE_BUCKET_SIZE)) > MCACHE_BUCKET_SIZE)
-        __size += MCACHE_BUCKET_SIZE;
-    if (__size % MCACHE_BUCKET_SIZE)
-        __size += MCACHE_BUCKET_SIZE - (__size % MCACHE_BUCKET_SIZE);
-    if (!__size)
+    if (size) {
+        __size = size + address_offset;
+        if (__size % MCACHE_BUCKET_SIZE) {
+            __size += MCACHE_BUCKET_SIZE - (__size % MCACHE_BUCKET_SIZE);
+        }
+    } else {
         __size = MCACHE_BUCKET_SIZE;
+    }
 
     entry = &mapcache->entry[address_index % mapcache->nr_buckets];