3 files changed, 17 insertions, 0 deletions
diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index e7dd07f47825..40b6c5ac46c0 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -196,3 +196,12 @@ config NFS_DEBUG
 	depends on NFS_FS && SUNRPC_DEBUG
 	select CRC32
 	default y
+
+config NFS_DISABLE_UDP_SUPPORT
+       bool "NFS: Disable NFS UDP protocol support"
+       depends on NFS_FS
+       default y
+       help
+	 Choose Y here to disable the use of NFS over UDP. NFS over UDP
+	 on modern networks (1Gb+) can lead to data corruption caused by
+	 fragmentation during high loads.
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 8f760f23748c..989c30c98511 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -474,6 +474,7 @@ void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
 			to->to_maxval = to->to_initval;
 		to->to_exponential = 0;
 		break;
+#ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
 	case XPRT_TRANSPORT_UDP:
 		if (retrans == NFS_UNSPEC_RETRANS)
 			to->to_retries = NFS_DEF_UDP_RETRANS;
@@ -484,6 +485,7 @@ void nfs_init_timeout_values(struct rpc_timeout *to, int proto,
 		to->to_maxval = NFS_MAX_UDP_TIMEOUT;
 		to->to_exponential = 1;
 		break;
+#endif
 	default:
 		BUG();
 	}
@@ -580,8 +582,10 @@ static int nfs_start_lockd(struct nfs_server *server)
 		default:
 			nlm_init.protocol = IPPROTO_TCP;
 			break;
+#ifndef CONFIG_NFS_DISABLE_UDP_SUPPORT
 		case XPRT_TRANSPORT_UDP:
 			nlm_init.protocol = IPPROTO_UDP;
+#endif
 	}
 
 	host = nlmclnt_init(&nlm_init);
diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index 0247dcb7b316..dfd95847f005 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -1215,6 +1215,10 @@ static int nfs_fs_context_validate(struct fs_context *fc)
 		}
 	} else {
 		nfs_set_mount_transport_protocol(ctx);
+#ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
+	       if (ctx->nfs_server.protocol == XPRT_TRANSPORT_UDP)
+		       goto out_invalid_transport_udp;
+#endif
 		if (ctx->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
 			port = NFS_RDMA_PORT;
 	}