[Qemu-devel] [PATCH] vpc: Round up image size during fixed image creation

[Kevin Wolf <kwolf@redhat.com>]

The geometry calculation algorithm from the VHD spec rounds the image
size down if it doesn't exactly match a geometry. During image
conversion, this causes the image to be truncated. For dynamic images,
we already have code in place to round up instead, let's do the same for
fixed images.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vpc.c |   23 ++++++++++-------------
 1 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/block/vpc.c b/block/vpc.c
index db6b14b..6b4816f 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -685,24 +685,21 @@ static int vpc_create(const char *filename, QEMUOptionParameter *options)
         return -EIO;
     }
 
+    /*
+     * Calculate matching total_size and geometry. Increase the number of
+     * sectors requested until we get enough (or fail). This ensures that
+     * qemu-img convert doesn't truncate images, but rather rounds up.
+     */
     total_sectors = total_size / BDRV_SECTOR_SIZE;
-    if (disk_type == VHD_DYNAMIC) {
-        /* Calculate matching total_size and geometry. Increase the number of
-           sectors requested until we get enough (or fail). */
-        for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl;
-             i++) {
-            if (calculate_geometry(total_sectors + i,
-                                   &cyls, &heads, &secs_per_cyl)) {
-                ret = -EFBIG;
-                goto fail;
-            }
-        }
-    } else {
-        if (calculate_geometry(total_sectors, &cyls, &heads, &secs_per_cyl)) {
+    for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) {
+        if (calculate_geometry(total_sectors + i, &cyls, &heads,
+                               &secs_per_cyl))
+        {
             ret = -EFBIG;
             goto fail;
         }
     }
+
     total_sectors = (int64_t) cyls * heads * secs_per_cyl;
 
     /* Prepare the Hard Disk Footer */
-- 
1.7.6.5