block: Export blk_pwritev_part() in block-backend-io.h

Also convert it into a generated_co_wrapper.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Message-Id: <20220705161527.1054072-10-afaria@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

block/block-backend.c

@@ -1403,20 +1403,6 @@ int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
     return blk_co_pwritev_part(blk, offset, bytes, qiov, 0, flags);
 }
 
-static int coroutine_fn blk_pwritev_part(BlockBackend *blk, int64_t offset,
-                                         int64_t bytes,
-                                         QEMUIOVector *qiov, size_t qiov_offset,
-                                         BdrvRequestFlags flags)
-{
-    int ret;
-
-    blk_inc_in_flight(blk);
-    ret = blk_do_pwritev_part(blk, offset, bytes, qiov, qiov_offset, flags);
-    blk_dec_in_flight(blk);
-
-    return ret;
-}
-
 typedef struct BlkRwCo {
     BlockBackend *blk;
     int64_t offset;

block/coroutines.h

@@ -107,11 +107,6 @@ bdrv_common_block_status_above(BlockDriverState *bs,
 int generated_co_wrapper
 nbd_do_establish_connection(BlockDriverState *bs, bool blocking, Error **errp);
 
-int generated_co_wrapper
-blk_do_pwritev_part(BlockBackend *blk, int64_t offset, int64_t bytes,
-                    QEMUIOVector *qiov, size_t qiov_offset,
-                    BdrvRequestFlags flags);
-
 int generated_co_wrapper
 blk_do_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
 

include/sysemu/block-backend-io.h

@@ -120,6 +120,10 @@ int generated_co_wrapper blk_preadv(BlockBackend *blk, int64_t offset,
 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
                                int64_t bytes, QEMUIOVector *qiov,
                                BdrvRequestFlags flags);
+int generated_co_wrapper blk_pwritev_part(BlockBackend *blk, int64_t offset,
+                                          int64_t bytes, QEMUIOVector *qiov,
+                                          size_t qiov_offset,
+                                          BdrvRequestFlags flags);
 int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
                                      int64_t bytes,
                                      QEMUIOVector *qiov, size_t qiov_offset,

tests/unit/test-block-iothread.c

@@ -183,6 +183,21 @@ static void test_sync_op_blk_preadv_part(BlockBackend *blk)
     g_assert_cmpint(ret, ==, -EIO);
 }
 
+static void test_sync_op_blk_pwritev_part(BlockBackend *blk)
+{
+    uint8_t buf[512] = { 0 };
+    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, sizeof(buf));
+    int ret;
+
+    /* Success */
+    ret = blk_pwritev_part(blk, 0, sizeof(buf), &qiov, 0, 0);
+    g_assert_cmpint(ret, ==, 0);
+
+    /* Early error: Negative offset */
+    ret = blk_pwritev_part(blk, -2, sizeof(buf), &qiov, 0, 0);
+    g_assert_cmpint(ret, ==, -EIO);
+}
+
 static void test_sync_op_load_vmstate(BdrvChild *c)
 {
     uint8_t buf[512];
@@ -358,6 +373,10 @@ const SyncOpTest sync_op_tests[] = {
         .name   = "/sync-op/preadv_part",
         .fn     = NULL,
         .blkfn  = test_sync_op_blk_preadv_part,
+    }, {
+        .name   = "/sync-op/pwritev_part",
+        .fn     = NULL,
+        .blkfn  = test_sync_op_blk_pwritev_part,
     }, {
         .name   = "/sync-op/load_vmstate",
         .fn     = test_sync_op_load_vmstate,