[Qemu-devel] [PATCH] qcow2: Fix image creation regression

[Kevin Wolf <kwolf@redhat.com>]

When checking for errors, commit db89119d compares with the wrong values,
failing image creation even when there was no error. Additionally, if an
error has occured, we can't preallocate the image (it's likely broken).

This unbreaks test 023 of qemu-iotests.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow2.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/qcow2.c b/block/qcow2.c
index 6632e6d..0e4cd98 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -986,7 +986,7 @@ static int qcow_create2(const char *filename, int64_t total_size,
     lseek(fd, s->refcount_block_offset, SEEK_SET);
     ret = qemu_write_full(fd, s->refcount_block,
 		    ref_clusters * s->cluster_size);
-    if (ret != s->cluster_size) {
+    if (ret != ref_clusters * s->cluster_size) {
         ret = -1;
         goto exit;
     }
@@ -998,7 +998,7 @@ exit:
     close(fd);
 
     /* Preallocate metadata */
-    if (prealloc) {
+    if (ret == 0 && prealloc) {
         BlockDriverState *bs;
         bs = bdrv_new("");
         bdrv_open(bs, filename, BDRV_O_CACHE_WB | BDRV_O_RDWR);
-- 
1.6.6.1