1 files changed, 30 insertions, 15 deletions

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 8f56e6b2f114..826b3877a157 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -268,7 +268,7 @@ static void nbd_size_clear(struct nbd_device *nbd)
 	}
 }
 
-static void nbd_size_update(struct nbd_device *nbd)
+static void nbd_size_update(struct nbd_device *nbd, bool start)
 {
 	struct nbd_config *config = nbd->config;
 	struct block_device *bdev = bdget_disk(nbd->disk, 0);
@@ -279,7 +279,8 @@ static void nbd_size_update(struct nbd_device *nbd)
 	if (bdev) {
 		if (bdev->bd_disk) {
 			bd_set_size(bdev, config->bytesize);
-			set_blocksize(bdev, config->blksize);
+			if (start)
+				set_blocksize(bdev, config->blksize);
 		} else
 			bdev->bd_invalidated = 1;
 		bdput(bdev);
@@ -294,7 +295,7 @@ static void nbd_size_set(struct nbd_device *nbd, loff_t blocksize,
 	config->blksize = blocksize;
 	config->bytesize = blocksize * nr_blocks;
 	if (nbd->task_recv != NULL)
-		nbd_size_update(nbd);
+		nbd_size_update(nbd, false);
 }
 
 static void nbd_complete_rq(struct request *req)
@@ -725,9 +726,9 @@ static void recv_work(struct work_struct *work)
 
 		blk_mq_complete_request(blk_mq_rq_from_pdu(cmd));
 	}
+	nbd_config_put(nbd);
 	atomic_dec(&config->recv_threads);
 	wake_up(&config->recv_wq);
-	nbd_config_put(nbd);
 	kfree(args);
 }
 
@@ -951,6 +952,12 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
 	if (!sock)
 		return err;
 
+	/*
+	 * We need to make sure we don't get any errant requests while we're
+	 * reallocating the ->socks array.
+	 */
+	blk_mq_freeze_queue(nbd->disk->queue);
+
 	if (!netlink && !nbd->task_setup &&
 	    !test_bit(NBD_BOUND, &config->runtime_flags))
 		nbd->task_setup = current;
@@ -960,25 +967,26 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
 	     test_bit(NBD_BOUND, &config->runtime_flags))) {
 		dev_err(disk_to_dev(nbd->disk),
 			"Device being setup by another task");
-		sockfd_put(sock);
-		return -EBUSY;
+		err = -EBUSY;
+		goto put_socket;
+	}
+
+	nsock = kzalloc(sizeof(*nsock), GFP_KERNEL);
+	if (!nsock) {
+		err = -ENOMEM;
+		goto put_socket;
 	}
 
 	socks = krealloc(config->socks, (config->num_connections + 1) *
 			 sizeof(struct nbd_sock *), GFP_KERNEL);
 	if (!socks) {
-		sockfd_put(sock);
-		return -ENOMEM;
+		kfree(nsock);
+		err = -ENOMEM;
+		goto put_socket;
 	}
 
 	config->socks = socks;
 
-	nsock = kzalloc(sizeof(struct nbd_sock), GFP_KERNEL);
-	if (!nsock) {
-		sockfd_put(sock);
-		return -ENOMEM;
-	}
-
 	nsock->fallback_index = -1;
 	nsock->dead = false;
 	mutex_init(&nsock->tx_lock);
@@ -988,8 +996,14 @@ static int nbd_add_socket(struct nbd_device *nbd, unsigned long arg,
 	nsock->cookie = 0;
 	socks[config->num_connections++] = nsock;
 	atomic_inc(&config->live_connections);
+	blk_mq_unfreeze_queue(nbd->disk->queue);
 
 	return 0;
+
+put_socket:
+	blk_mq_unfreeze_queue(nbd->disk->queue);
+	sockfd_put(sock);
+	return err;
 }
 
 static int nbd_reconnect_socket(struct nbd_device *nbd, unsigned long arg)
@@ -1226,7 +1240,7 @@ static int nbd_start_device(struct nbd_device *nbd)
 		args->index = i;
 		queue_work(nbd->recv_workq, &args->work);
 	}
-	nbd_size_update(nbd);
+	nbd_size_update(nbd, true);
 	return error;
 }
 
@@ -1426,6 +1440,7 @@ static void nbd_release(struct gendisk *disk, fmode_t mode)
 	if (test_bit(NBD_DISCONNECT_ON_CLOSE, &nbd->config->runtime_flags) &&
 			bdev->bd_openers == 0)
 		nbd_disconnect_and_put(nbd);
+	bdput(bdev);
 
 	nbd_config_put(nbd);
 	nbd_put(nbd);