@@ -110,10 +110,6 @@ static int qcow2_cache_entry_flush(BlockDriverState *bs, Qcow2Cache *c, int i)
BDRVQcowState *s = bs->opaque;
int ret = 0;
- if (!c->entries[i].dirty || !c->entries[i].offset) {
- return 0;
- }
-
trace_qcow2_cache_entry_flush(qemu_coroutine_self(),
c == s->l2_table_cache, i);
@@ -166,19 +162,23 @@ int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c)
{
BDRVQcowState *s = bs->opaque;
int result = 0;
+ bool need_bdrv_flush = false;
int ret;
int i;
trace_qcow2_cache_flush(qemu_coroutine_self(), c == s->l2_table_cache);
for (i = 0; i < c->size; i++) {
- ret = qcow2_cache_entry_flush(bs, c, i);
- if (ret < 0 && result != -ENOSPC) {
- result = ret;
+ if (c->entries[i].dirty && c->entries[i].offset) {
+ ret = qcow2_cache_entry_flush(bs, c, i);
+ if (ret < 0 && result != -ENOSPC) {
+ result = ret;
+ }
+ need_bdrv_flush = true;
}
}
- if (result == 0) {
+ if (need_bdrv_flush && result == 0) {
ret = bdrv_flush(bs->file);
if (ret < 0) {
result = ret;
@@ -289,9 +289,11 @@ static int qcow2_cache_do_get(BlockDriverState *bs, Qcow2Cache *c,
return i;
}
- ret = qcow2_cache_entry_flush(bs, c, i);
- if (ret < 0) {
- return ret;
+ if (c->entries[i].dirty && c->entries[i].offset) {
+ ret = qcow2_cache_entry_flush(bs, c, i);
+ if (ret < 0) {
+ return ret;
+ }
}
trace_qcow2_cache_get_read(qemu_coroutine_self(),
Needless to call bdrv_flush() in qcow2_cache_flush() if no cache entry is dirty. Signed-off-by: Zhang Haoyu <zhanghy@sangfor.com> --- block/qcow2-cache.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)