From: Kevin Wolf <kwolf@redhat.com>
Date: Sat, 8 Feb 2014 09:42:18 +0000 (+0100)
Subject: block: Fix 32 bit truncation in mark_request_serialising()
X-Git-Tag: qemu-xen-4.5.0-rc1~201^2
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=e96126ffa53d36ec75a1ee900a6b7e7c82d9bb9c;p=qemu-upstream-4.5-testing.git

block: Fix 32 bit truncation in mark_request_serialising()

On 32 bit hosts, size_t is too small for align as the bitmask
~(align - 1) will zero out the higher 32 bits of the offset.

While at it, change the local overlap_bytes variable to unsigned to
match the field in BdrvTrackedRequest.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---

diff --git a/block.c b/block.c
index b0c502597..636aa117c 100644
--- a/block.c
+++ b/block.c
@@ -2240,11 +2240,11 @@ static void tracked_request_begin(BdrvTrackedRequest *req,
     QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
 }
 
-static void mark_request_serialising(BdrvTrackedRequest *req, size_t align)
+static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
 {
     int64_t overlap_offset = req->offset & ~(align - 1);
-    int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
-                      - overlap_offset;
+    unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
+                               - overlap_offset;
 
     if (!req->serialising) {
         req->bs->serialising_in_flight++;