From: Olga Kornievskaia <kolga@xxxxxxxxxx>
Add a kernel config CONFIG_NFS_DISABLE_UDP_SUPPORT to disallow NFS
UDP mounts.
I took the same approach as Chuck's deprecation of DES enc types
to start with default to still allow but I think the ultimate
goal is to disable
Question: how do we have folks trying this unless we set it to false?
Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
---
fs/nfs/Kconfig | 10 ++++++++++
fs/nfs/client.c | 4 ++++
fs/nfs/super.c | 8 ++++++++
3 files changed, 22 insertions(+)
diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig
index 295a7a2..6320113 100644
--- a/fs/nfs/Kconfig
+++ b/fs/nfs/Kconfig
@@ -196,3 +196,13 @@ 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 n
+ 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.
+ The default is N because many deployments still use UDP.
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 02110a3..24ca314 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;
+#ifdef 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;
+#ifdef 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/super.c b/fs/nfs/super.c
index a84df7d6..21e59da 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1011,7 +1011,9 @@ static void nfs_set_port(struct sockaddr *sap, int *port,
static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
{
switch (mnt->nfs_server.protocol) {
+#ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
case XPRT_TRANSPORT_UDP:
+#endif
case XPRT_TRANSPORT_TCP:
case XPRT_TRANSPORT_RDMA:
break;
@@ -1033,8 +1035,10 @@ static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
return;
switch (mnt->nfs_server.protocol) {
case XPRT_TRANSPORT_UDP:
+#ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
break;
+#endif
case XPRT_TRANSPORT_TCP:
case XPRT_TRANSPORT_RDMA:
mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
@@ -2204,6 +2208,10 @@ static int nfs_validate_text_mount_data(void *options,
#endif /* CONFIG_NFS_V4 */
} else {
nfs_set_mount_transport_protocol(args);
+#ifdef CONFIG_NFS_DISABLE_UDP_SUPPORT
+ if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
+ goto out_invalid_transport_udp;
+#endif
if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
port = NFS_RDMA_PORT;
}
--
1.8.3.1
