Commit c1f5bafd authored Mar 04, 2013 by Stefan Hajnoczi

qcow2: set L2 cache dependency in qcow2_alloc_bytes()



Compressed writes use qcow2_alloc_bytes() to allocate space with byte
granularity.  The affected clusters' refcounts will be incremented but
we do not need to flush yet.

Set a L2 cache dependency on the refcount block cache, so that the
refcounts get written out before the L2 updates.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

parent f6977f15

block/qcow2-refcount.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -669,7 +669,11 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
		}
		}

		bdrv_flush(bs->file);
		/* The cluster refcount was incremented, either by qcow2_alloc_clusters()
		* or explicitly by update_cluster_refcount(). Refcount blocks must be
		* flushed before the caller's L2 table updates.
		*/
		qcow2_cache_set_dependency(bs, s->l2_table_cache, s->refcount_block_cache);
		return offset;
		}