nbd: Fully initialize client in case of failed negotiation

[mirror_qemu.git] / nbd / server.c

diff --git a/nbd/server.c b/nbd/server.c
index ac92fa072751262ca0715504f1232b5c2e745470..edfda84d4320cf81a0ffa3905656f00083529bdd 100644 (file)
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -891,9 +891,21 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
 {
     BlockBackend *blk;
     NBDExport *exp = g_malloc0(sizeof(NBDExport));
+    uint64_t perm;
+    int ret;
 
-    blk = blk_new();
-    blk_insert_bs(blk, bs);
+    /* Don't allow resize while the NBD server is running, otherwise we don't
+     * care what happens with the node. */
+    perm = BLK_PERM_CONSISTENT_READ;
+    if ((nbdflags & NBD_FLAG_READ_ONLY) == 0) {
+        perm |= BLK_PERM_WRITE;
+    }
+    blk = blk_new(perm, BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
+                        BLK_PERM_WRITE | BLK_PERM_GRAPH_MOD);
+    ret = blk_insert_bs(blk, bs, errp);
+    if (ret < 0) {
+        goto fail;
+    }
     blk_set_enable_write_cache(blk, !writethrough);
 
     exp->refcount = 1;
@@ -1364,16 +1376,14 @@ static coroutine_fn void nbd_co_client_start(void *opaque)
 
     if (exp) {
         nbd_export_get(exp);
+        QTAILQ_INSERT_TAIL(&exp->clients, client, next);
     }
+    qemu_co_mutex_init(&client->send_lock);
+
     if (nbd_negotiate(data)) {
         client_close(client);
         goto out;
     }
-    qemu_co_mutex_init(&client->send_lock);
-
-    if (exp) {
-        QTAILQ_INSERT_TAIL(&exp->clients, client, next);
-    }
 
     nbd_client_receive_next_request(client);