block: Catch duplicate IDs in bdrv_new()

Since commit f298d071, block devices added with blockdev-add don't have
a QemuOpts around in dinfo->opts. Consequently, we can't rely any more
on QemuOpts catching duplicate IDs for block devices.

This patch adds a new check for duplicate IDs to bdrv_new(), and moves
the existing check that the ID isn't already taken for a node-name there
as well.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

block.c

@@ -336,6 +336,17 @@ BlockDriverState *bdrv_new(const char *device_name, Error **errp)
 {
     BlockDriverState *bs;
 
+    if (bdrv_find(device_name)) {
+        error_setg(errp, "Device with id '%s' already exists",
+                   device_name);
+        return NULL;
+    }
+    if (bdrv_find_node(device_name)) {
+        error_setg(errp, "Device with node-name '%s' already exists",
+                   device_name);
+        return NULL;
+    }
+
     bs = g_malloc0(sizeof(BlockDriverState));
     QLIST_INIT(&bs->dirty_bitmaps);
     pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);

blockdev.c

@@ -452,12 +452,6 @@ static DriveInfo *blockdev_init(const char *file, QDict *bs_opts,
         }
     }
 
-    if (bdrv_find_node(qemu_opts_id(opts))) {
-        error_setg(errp, "device id=%s is conflicting with a node-name",
-                   qemu_opts_id(opts));
-        goto early_err;
-    }
-
     /* init */
     dinfo = g_malloc0(sizeof(*dinfo));
     dinfo->id = g_strdup(qemu_opts_id(opts));

tests/qemu-iotests/087

@@ -72,6 +72,39 @@ run_qemu <<EOF
 { "execute": "quit" }
 EOF
 
+echo
+echo === Duplicate ID ===
+echo
+
+run_qemu <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "blockdev-add",
+  "arguments": {
+      "options": {
+        "driver": "$IMGFMT",
+        "id": "disk",
+        "file": {
+            "driver": "file",
+            "filename": "$TEST_IMG"
+        }
+      }
+    }
+  }
+{ "execute": "blockdev-add",
+  "arguments": {
+      "options": {
+        "driver": "$IMGFMT",
+        "id": "disk",
+        "file": {
+            "driver": "file",
+            "filename": "$TEST_IMG"
+        }
+      }
+    }
+  }
+{ "execute": "quit" }
+EOF
+
 echo
 echo === aio=native without O_DIRECT ===
 echo

tests/qemu-iotests/087.out

@@ -13,6 +13,19 @@ QMP_VERSION
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "DEVICE_TRAY_MOVED", "data": {"device": "floppy0", "tray-open": true}}
 
 
+=== Duplicate ID ===
+
+Testing:
+QMP_VERSION
+{"return": {}}
+{"return": {}}
+{"error": {"class": "GenericError", "desc": "Device with id 'disk' already exists"}}
+{"return": {}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN"}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "DEVICE_TRAY_MOVED", "data": {"device": "ide1-cd0", "tray-open": true}}
+{"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "DEVICE_TRAY_MOVED", "data": {"device": "floppy0", "tray-open": true}}
+
+
 === aio=native without O_DIRECT ===
 
 Testing: