[Qemu-block] [PULL 23/39] block: Allow .bdrv_load/save_vmstate() to return 0/-errno

[Kevin Wolf]

The return value of .bdrv_load/save_vmstate() can be any non-negative
number in case of success now. It used to be bytes/-errno.

Signed-off-by: Kevin Wolf <kw...@redhat.com>
Reviewed-by: Fam Zheng <f...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
---
 block/io.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/block/io.c b/block/io.c
index aac9b67..af4d43e 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1848,9 +1848,16 @@ int bdrv_save_vmstate(BlockDriverState *bs, const 
uint8_t *buf,
         .iov_base   = (void *) buf,
         .iov_len    = size,
     };
+    int ret;
 
     qemu_iovec_init_external(&qiov, &iov, 1);
-    return bdrv_writev_vmstate(bs, &qiov, pos);
+
+    ret = bdrv_writev_vmstate(bs, &qiov, pos);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return size;
 }
 
 int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
@@ -1876,9 +1883,15 @@ int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
         .iov_base   = buf,
         .iov_len    = size,
     };
+    int ret;
 
     qemu_iovec_init_external(&qiov, &iov, 1);
-    return bdrv_readv_vmstate(bs, &qiov, pos);
+    ret = bdrv_readv_vmstate(bs, &qiov, pos);
+    if (ret < 0) {
+        return ret;
+    }
+
+    return size;
 }
 
 int bdrv_readv_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
-- 
1.8.3.1