[PATCH 2/3] block/block-backend: delegate blk_co_preadv to blk_co_preadv_part

[Bin Guo <guobin@linux.alibaba.com>]

blk_co_preadv() and blk_co_preadv_part() share identical bodies except
that blk_co_preadv() always passes qiov_offset=0.  blk_co_pwritev()
already uses this pattern and simply calls blk_co_pwritev_part() with
qiov_offset=0.  Apply the same simplification to the read side so that
both pairs are consistent and the shared logic lives in a single place.

Before this change blk_co_preadv() duplicated the
blk_inc_in_flight / blk_co_do_preadv_part / blk_dec_in_flight
sequence.  After this change it is a one-liner wrapper, matching the
write side.

Signed-off-by: Bin Guo <guobin@linux.alibaba.com>
---
 block/block-backend.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index 9944657120..490b149bf8 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1376,14 +1376,8 @@ int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
                                int64_t bytes, QEMUIOVector *qiov,
                                BdrvRequestFlags flags)
 {
-    int ret;
     IO_OR_GS_CODE();
-
-    blk_inc_in_flight(blk);
-    ret = blk_co_do_preadv_part(blk, offset, bytes, qiov, 0, flags);
-    blk_dec_in_flight(blk);
-
-    return ret;
+    return blk_co_preadv_part(blk, offset, bytes, qiov, 0, flags);
 }
 
 int coroutine_fn blk_co_preadv_part(BlockBackend *blk, int64_t offset,
-- 
2.50.1 (Apple Git-155)