qcow2: flush refcount cache correctly in alloc_refcount_block()

update_refcount() affects the refcount cache, it does not write to disk.
Therefore bdrv_flush(bs->file) does nothing.  We need to flush the
refcount cache in order to write out the refcount updates!

While we're here also add error returns when qcow2_cache_flush() fails.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
master
Stefan Hajnoczi 2013-03-04 15:02:30 +01:00
parent 74c4510a3c
commit 9991923b26
1 changed files with 8 additions and 2 deletions

View File

@ -201,7 +201,10 @@ static int alloc_refcount_block(BlockDriverState *bs,
*refcount_block = NULL;
/* We write to the refcount table, so we might depend on L2 tables */
qcow2_cache_flush(bs, s->l2_table_cache);
ret = qcow2_cache_flush(bs, s->l2_table_cache);
if (ret < 0) {
return ret;
}
/* Allocate the refcount block itself and mark it as used */
int64_t new_block = alloc_clusters_noref(bs, s->cluster_size);
@ -237,7 +240,10 @@ static int alloc_refcount_block(BlockDriverState *bs,
goto fail_block;
}
bdrv_flush(bs->file);
ret = qcow2_cache_flush(bs, s->refcount_block_cache);
if (ret < 0) {
goto fail_block;
}
/* Initialize the new refcount block only after updating its refcount,
* update_refcount uses the refcount cache itself */