* MKDEV() expect that the max bits of first_minor is 20.
                 */
                if (index < 0 || index > MINORMASK >> part_shift) {
-                       printk(KERN_ERR "nbd: illegal input index %d\n", index);
+                       pr_err("illegal input index %d\n", index);
                        return -EINVAL;
                }
        }
        if (!info->attrs[NBD_ATTR_SOCKETS]) {
-               printk(KERN_ERR "nbd: must specify at least one socket\n");
+               pr_err("must specify at least one socket\n");
                return -EINVAL;
        }
        if (!info->attrs[NBD_ATTR_SIZE_BYTES]) {
-               printk(KERN_ERR "nbd: must specify a size in bytes for the device\n");
+               pr_err("must specify a size in bytes for the device\n");
                return -EINVAL;
        }
 again:
                nbd_put(nbd);
                if (index == -1)
                        goto again;
-               printk(KERN_ERR "nbd: nbd%d already in use\n", index);
+               pr_err("nbd%d already in use\n", index);
                return -EBUSY;
        }
        if (WARN_ON(nbd->config)) {
        if (IS_ERR(config)) {
                mutex_unlock(&nbd->config_lock);
                nbd_put(nbd);
-               printk(KERN_ERR "nbd: couldn't allocate config\n");
+               pr_err("couldn't allocate config\n");
                return PTR_ERR(config);
        }
        nbd->config = config;
                        struct nlattr *socks[NBD_SOCK_MAX+1];
 
                        if (nla_type(attr) != NBD_SOCK_ITEM) {
-                               printk(KERN_ERR "nbd: socks must be embedded in a SOCK_ITEM attr\n");
+                               pr_err("socks must be embedded in a SOCK_ITEM attr\n");
                                ret = -EINVAL;
                                goto out;
                        }
                                                          nbd_sock_policy,
                                                          info->extack);
                        if (ret != 0) {
-                               printk(KERN_ERR "nbd: error processing sock list\n");
+                               pr_err("error processing sock list\n");
                                ret = -EINVAL;
                                goto out;
                        }
                return -EPERM;
 
        if (!info->attrs[NBD_ATTR_INDEX]) {
-               printk(KERN_ERR "nbd: must specify an index to disconnect\n");
+               pr_err("must specify an index to disconnect\n");
                return -EINVAL;
        }
        index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
        nbd = idr_find(&nbd_index_idr, index);
        if (!nbd) {
                mutex_unlock(&nbd_index_mutex);
-               printk(KERN_ERR "nbd: couldn't find device at index %d\n",
-                      index);
+               pr_err("couldn't find device at index %d\n", index);
                return -EINVAL;
        }
        if (!refcount_inc_not_zero(&nbd->refs)) {
                mutex_unlock(&nbd_index_mutex);
-               printk(KERN_ERR "nbd: device at index %d is going down\n",
-                      index);
+               pr_err("device at index %d is going down\n", index);
                return -EINVAL;
        }
        mutex_unlock(&nbd_index_mutex);
                return -EPERM;
 
        if (!info->attrs[NBD_ATTR_INDEX]) {
-               printk(KERN_ERR "nbd: must specify a device to reconfigure\n");
+               pr_err("must specify a device to reconfigure\n");
                return -EINVAL;
        }
        index = nla_get_u32(info->attrs[NBD_ATTR_INDEX]);
        nbd = idr_find(&nbd_index_idr, index);
        if (!nbd) {
                mutex_unlock(&nbd_index_mutex);
-               printk(KERN_ERR "nbd: couldn't find a device at index %d\n",
-                      index);
+               pr_err("couldn't find a device at index %d\n", index);
                return -EINVAL;
        }
        if (nbd->backend) {
        }
        if (!refcount_inc_not_zero(&nbd->refs)) {
                mutex_unlock(&nbd_index_mutex);
-               printk(KERN_ERR "nbd: device at index %d is going down\n",
-                      index);
+               pr_err("device at index %d is going down\n", index);
                return -EINVAL;
        }
        mutex_unlock(&nbd_index_mutex);
                        struct nlattr *socks[NBD_SOCK_MAX+1];
 
                        if (nla_type(attr) != NBD_SOCK_ITEM) {
-                               printk(KERN_ERR "nbd: socks must be embedded in a SOCK_ITEM attr\n");
+                               pr_err("socks must be embedded in a SOCK_ITEM attr\n");
                                ret = -EINVAL;
                                goto out;
                        }
                                                          nbd_sock_policy,
                                                          info->extack);
                        if (ret != 0) {
-                               printk(KERN_ERR "nbd: error processing sock list\n");
+                               pr_err("error processing sock list\n");
                                ret = -EINVAL;
                                goto out;
                        }
        BUILD_BUG_ON(sizeof(struct nbd_request) != 28);
 
        if (max_part < 0) {
-               printk(KERN_ERR "nbd: max_part must be >= 0\n");
+               pr_err("max_part must be >= 0\n");
                return -EINVAL;
        }
 
                nbd = list_first_entry(&del_list, struct nbd_device, list);
                list_del_init(&nbd->list);
                if (refcount_read(&nbd->config_refs))
-                       printk(KERN_ERR "nbd: possibly leaking nbd_config (ref %d)\n",
+                       pr_err("possibly leaking nbd_config (ref %d)\n",
                                        refcount_read(&nbd->config_refs));
                if (refcount_read(&nbd->refs) != 1)
-                       printk(KERN_ERR "nbd: possibly leaking a device\n");
+                       pr_err("possibly leaking a device\n");
                nbd_put(nbd);
        }