[PATCH v3 2/6] block-backend: improve blk_root_get_parent_desc()

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

We have different types of parents: block nodes, block backends and
jobs. So, it makes sense to specify type together with name.

While being here also use g_autofree.

iotest 307 output is updated.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
---
 block/block-backend.c      | 9 ++++-----
 tests/qemu-iotests/307.out | 2 +-
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/block/block-backend.c b/block/block-backend.c
index d1a33a2c8e..5be32c0c42 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -141,19 +141,18 @@ static void blk_root_set_aio_ctx(BdrvChild *child, AioContext *ctx,
 static char *blk_root_get_parent_desc(BdrvChild *child)
 {
     BlockBackend *blk = child->opaque;
-    char *dev_id;
+    g_autofree char *dev_id = NULL;
 
     if (blk->name) {
-        return g_strdup(blk->name);
+        return g_strdup_printf("block device '%s'", blk->name);
     }
 
     dev_id = blk_get_attached_dev_id(blk);
     if (*dev_id) {
-        return dev_id;
+        return g_strdup_printf("block device '%s'", dev_id);
     } else {
         /* TODO Callback into the BB owner for something more detailed */
-        g_free(dev_id);
-        return g_strdup("a block device");
+        return g_strdup("an unnamed block device");
     }
 }
 
diff --git a/tests/qemu-iotests/307.out b/tests/qemu-iotests/307.out
index daa8ad2da0..66bf2ddb74 100644
--- a/tests/qemu-iotests/307.out
+++ b/tests/qemu-iotests/307.out
@@ -53,7 +53,7 @@ exports available: 1
 
 === Add a writable export ===
 {"execute": "block-export-add", "arguments": {"description": "This is the writable second export", "id": "export1", "name": "export1", "node-name": "fmt", "type": "nbd", "writable": true, "writethrough": true}}
-{"error": {"class": "GenericError", "desc": "Conflicts with use by sda as 'root', which does not allow 'write' on fmt"}}
+{"error": {"class": "GenericError", "desc": "Conflicts with use by block device 'sda' as 'root', which does not allow 'write' on fmt"}}
 {"execute": "device_del", "arguments": {"id": "sda"}}
 {"return": {}}
 {"data": {"device": "sda", "path": "/machine/peripheral/sda"}, "event": "DEVICE_DELETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
-- 
2.29.2