block: Allow bdrv_flush to return errors
This changes bdrv_flush to return 0 on success and -errno in case of failure.
It's a requirement for implementing proper error handle in users of bdrv_flush.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
diff --git a/block_int.h b/block_int.h
index 87e60b8..3c3adb5 100644
--- a/block_int.h
+++ b/block_int.h
@@ -59,7 +59,7 @@
const uint8_t *buf, int nb_sectors);
void (*bdrv_close)(BlockDriverState *bs);
int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
- void (*bdrv_flush)(BlockDriverState *bs);
+ int (*bdrv_flush)(BlockDriverState *bs);
int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum);
int (*bdrv_set_key)(BlockDriverState *bs, const char *key);