From 9e4751b3a9c0435c4cb199c353144acb55458473 Mon Sep 17 00:00:00 2001
From: Sebastian Mitterle <smitterl@redhat.com>
Date: Sat, 29 Aug 2020 00:49:07 +0000
Subject: [PATCH 027/108] disk storage: fix allocation size for pool format dos

The changed condition was always false because the function was always
called with boundary values 0.

Use the free extent's start value to get its start offset from the
cylinder boundary and determine if the needed size for allocation
needs to be expanded too in case the offset doesn't fit within extra
bytes for alignment.

This fixes an issue where vol-create-from will call qemu-img convert
to create a destination volume of same capacity as the source volume
and qemu-img will error 'Cannot grow device files' due to the partition
being too small for the source although both destination partition and
source volume have the same capacity.

Signed-off-by: Sebastian Mitterle <smitterl@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
(cherry picked from commit 653fdf48e352814efdbff72aa5421f65385088ac)
---
 src/storage/storage_backend_disk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/storage/storage_backend_disk.c b/src/storage/storage_backend_disk.c
index eae23ec24a..da06357b90 100644
--- a/src/storage/storage_backend_disk.c
+++ b/src/storage/storage_backend_disk.c
@@ -691,7 +691,7 @@ virStorageBackendDiskPartBoundaries(virStoragePoolObjPtr pool,
          if (def->source.format == VIR_STORAGE_POOL_DISK_DOS) {
              /* align to cylinder boundary */
              neededSize += extraBytes;
-             if ((*start % cylinderSize) > extraBytes) {
+             if ((dev->freeExtents[i].start % cylinderSize) > extraBytes) {
                  /* add an extra cylinder if the offset can't fit within
                     the extra bytes we have */
                  neededSize += cylinderSize;
-- 
2.33.0