[PATCH RFC 0/3] Remove NFS v2 support from the client and server

[PATCH RFC 0/3] Remove NFS v2 support from the client and server

[Steve Dickson]

These patches will remove the all references and 
support of NFS v2 in both the server and client.

On server side the support has been off, by default, 
since 2013 (6b4e4965a6b). With this server patch the
ability to enable v2 will be remove.

Currently even with CONFIG_NFS_V2 not set
v2 mounts are still tied (over-the-wire). I looked at creating 
a kernel parameter module so support could re-enabled 
but that got ugly quick.

So I just decided to make all V2 mounts fail with
EOPNOTSUPP, with no way of turn them back on.

Steve Dickson (3):
  nfsd: Remove the ability to enable NFS v2.
  nfs.man: Remove references to NFS v2 from the man pages
  mount: Remove NFS v2 support from mount.nfs

 nfs.conf                  |  1 -
 utils/mount/configfile.c  |  2 +-
 utils/mount/mount.nfs.man |  2 +-
 utils/mount/network.c     |  4 ++--
 utils/mount/nfs.man       | 20 +++-----------------
 utils/mount/nfsmount.conf |  2 +-
 utils/mount/stropts.c     |  3 +++
 utils/nfsd/nfsd.c         |  2 --
 utils/nfsd/nfsd.man       |  4 ++--
 9 files changed, 13 insertions(+), 27 deletions(-)

-- 
2.31.1

[PATCH RFC 1/3] nfsd: Remove the ability to enable NFS v2.

[Steve Dickson]

Signed-off-by: Steve Dickson <steved@redhat.com>
---
 nfs.conf            | 1 -
 utils/nfsd/nfsd.c   | 2 --
 utils/nfsd/nfsd.man | 4 ++--
 3 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/nfs.conf b/nfs.conf
index 8c714ff7..21d3e7b2 100644
--- a/nfs.conf
+++ b/nfs.conf
@@ -68,7 +68,6 @@
 # lease-time=90
 # udp=n
 # tcp=y
-# vers2=n
 # vers3=y
 # vers4=y
 # vers4.0=y
diff --git a/utils/nfsd/nfsd.c b/utils/nfsd/nfsd.c
index b0741718..4016a761 100644
--- a/utils/nfsd/nfsd.c
+++ b/utils/nfsd/nfsd.c
@@ -226,7 +226,6 @@ main(int argc, char **argv)
 				}
 				/* FALLTHRU */
 			case 3:
-			case 2:
 				NFSCTL_VERUNSET(versbits, c);
 				break;
 			default:
@@ -251,7 +250,6 @@ main(int argc, char **argv)
 					minorvers = minorversset = minormask;
 				/* FALLTHRU */
 			case 3:
-			case 2:
 				NFSCTL_VERSET(versbits, c);
 				break;
 			default:
diff --git a/utils/nfsd/nfsd.man b/utils/nfsd/nfsd.man
index 2701ba78..716f538b 100644
--- a/utils/nfsd/nfsd.man
+++ b/utils/nfsd/nfsd.man
@@ -57,7 +57,7 @@ This option can be used to request that
 .B rpc.nfsd
 does not offer certain versions of NFS. The current version of
 .B rpc.nfsd
-can support major NFS versions 2,3,4 and the minor versions 4.0, 4.1 and 4.2.
+can support major NFS versions 3,4 and the minor versions 4.0, 4.1 and 4.2.
 .TP
 .B \-s " or " \-\-syslog
 By default,
@@ -84,7 +84,7 @@ This option can be used to request that
 .B rpc.nfsd
 offer certain versions of NFS. The current version of
 .B rpc.nfsd
-can support major NFS versions 2,3,4 and the minor versions 4.0, 4.1 and 4.2.
+can support major NFS versions 3,4 and the minor versions 4.0, 4.1 and 4.2.
 .TP
 .B \-L " or " \-\-lease-time seconds
 Set the lease-time used for NFSv4.  This corresponds to how often
-- 
2.31.1

[PATCH RFC 2/3] nfs.man: Remove references to NFS v2 from the man pages

[Steve Dickson]

Signed-off-by: Steve Dickson <steved@redhat.com>
---
 utils/mount/mount.nfs.man |  2 +-
 utils/mount/nfs.man       | 20 +++-----------------
 2 files changed, 4 insertions(+), 18 deletions(-)

diff --git a/utils/mount/mount.nfs.man b/utils/mount/mount.nfs.man
index 0409c96f..a78a3b0d 100644
--- a/utils/mount/mount.nfs.man
+++ b/utils/mount/mount.nfs.man
@@ -27,7 +27,7 @@ can mount all NFS file system versions.  Under earlier Linux kernel versions,
 .BR mount.nfs4
 must be used for mounting NFSv4 file systems while
 .BR mount.nfs
-must be used for NFSv3 and v2.
+must be used for NFSv3.
 
 .SH OPTIONS
 .TP
diff --git a/utils/mount/nfs.man b/utils/mount/nfs.man
index 57a693fd..d9f34df3 100644
--- a/utils/mount/nfs.man
+++ b/utils/mount/nfs.man
@@ -12,7 +12,7 @@ created by Sun Microsystems in 1984. NFS was developed
 to allow file sharing between systems residing
 on a local area network.
 Depending on kernel configuration, the Linux NFS client may
-support NFS versions 2, 3, 4.0, 4.1, or 4.2.
+support NFS versions 3, 4.0, 4.1, or 4.2.
 .P
 The
 .BR mount (8)
@@ -954,11 +954,6 @@ file. See
 .BR nfsmount.conf(5)
 for details.
 .SH EXAMPLES
-To mount an export using NFS version 2,
-use the
-.B nfs
-file system type and specify the
-.B nfsvers=2
 mount option.
 To mount using NFS version 3,
 use the
@@ -985,13 +980,6 @@ reasonable defaults for NFS behavior.
 	server:/export	/mnt	nfs	defaults	0 0
 .fi
 .P
-Here is an example from an /etc/fstab file for an NFS version 2 mount over UDP.
-.P
-.nf
-.ta 8n +16n +6n +6n +30n
-	server:/export	/mnt	nfs	nfsvers=2,proto=udp	0 0
-.fi
-.P
 This example shows how to mount using NFS version 4 over TCP
 with Kerberos 5 mutual authentication.
 .P
@@ -1084,7 +1072,7 @@ and
 can safely be allowed to default to the largest values supported by
 both client and server, independent of the network's MTU size.
 .SS "Using the mountproto mount option"
-This section applies only to NFS version 2 and version 3 mounts
+This section applies only to NFS version 3 mounts
 since NFS version 4 does not use a separate protocol for mount
 requests.
 .P
@@ -1487,7 +1475,7 @@ the use of the
 mount option.
 .SS "Using file locks with NFS"
 The Network Lock Manager protocol is a separate sideband protocol
-used to manage file locks in NFS version 2 and version 3.
+used to manage file locks in NFS version 3.
 To support lock recovery after a client or server reboot,
 a second sideband protocol --
 known as the Network Status Manager protocol --
@@ -1907,8 +1895,6 @@ RFC 768 for the UDP specification.
 .br
 RFC 793 for the TCP specification.
 .br
-RFC 1094 for the NFS version 2 specification.
-.br
 RFC 1813 for the NFS version 3 specification.
 .br
 RFC 1832 for the XDR specification.
-- 
2.31.1

[PATCH RFC 3/3] mount: Remove NFS v2 support from mount.nfs

[Steve Dickson]

This patch removes the ability to do NFS v2
mounts. They will now fail with EOPNOTSUPP.

Signed-off-by: Steve Dickson <steved@redhat.com>
---
 utils/mount/configfile.c  | 2 +-
 utils/mount/network.c     | 4 ++--
 utils/mount/nfsmount.conf | 2 +-
 utils/mount/stropts.c     | 3 +++
 4 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/utils/mount/configfile.c b/utils/mount/configfile.c
index 3d3684ef..1d88cbfc 100644
--- a/utils/mount/configfile.c
+++ b/utils/mount/configfile.c
@@ -71,7 +71,7 @@ struct mnt_alias {
 int mnt_alias_sz = (sizeof(mnt_alias_tab)/sizeof(mnt_alias_tab[0]));
 
 static const char *version_keys[] = {
-	"v2", "v3", "v4", "vers", "nfsvers", "minorversion", NULL
+	"v3", "v4", "vers", "nfsvers", "minorversion", NULL
 };
 
 static int strict;
diff --git a/utils/mount/network.c b/utils/mount/network.c
index 35261171..bfda5c41 100644
--- a/utils/mount/network.c
+++ b/utils/mount/network.c
@@ -97,7 +97,7 @@ static const char *nfs_transport_opttbl[] = {
 };
 
 static const char *nfs_version_opttbl[] = {
-	"v2",
+	"v2", /* no longer supported */
 	"v3",
 	"v4",
 	"vers",
@@ -1286,7 +1286,7 @@ nfs_nfs_version(char *type, struct mount_options *options, struct nfs_version *v
 	else if (found < 0)
 		return 1;
 	else if (found <= 2 ) {
-		/* v2, v3, v4 */
+		/* v3, v4 */
 		version_val = version_key + 1;
 		version->v_mode = V_SPECIFIC;
 	} else if (found > 2 ) {
diff --git a/utils/mount/nfsmount.conf b/utils/mount/nfsmount.conf
index 6bdc225a..342063f7 100644
--- a/utils/mount/nfsmount.conf
+++ b/utils/mount/nfsmount.conf
@@ -28,7 +28,7 @@
 # This statically named section defines global mount 
 # options that can be applied on all NFS mount.
 #
-# Protocol Version [2,3,4]
+# Protocol Version [3,4]
 # This defines the default protocol version which will
 # be used to start the negotiation with the server.
 # Defaultvers=4
diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index fa67a66f..f6f0c1d5 100644
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -357,6 +357,7 @@ static int nfs_insert_sloppy_option(struct mount_options *options)
 
 static int nfs_set_version(struct nfsmount_info *mi)
 {
+
 	if (!nfs_nfs_version(mi->type, mi->options, &mi->version))
 		return 0;
 
@@ -1017,6 +1018,8 @@ static int nfs_try_mount(struct nfsmount_info *mi)
 
 	switch (mi->version.major) {
 		case 2:
+			errno = EOPNOTSUPP;
+			break;
 		case 3:
 			result = nfs_try_mount_v3v2(mi, FALSE);
 			break;
-- 
2.31.1

Re: [PATCH RFC 0/3] Remove NFS v2 support from the client and server

[NeilBrown]

On Tue, 30 Nov 2021, Steve Dickson wrote:
> These patches will remove the all references and 
> support of NFS v2 in both the server and client.

What is the motivation for this?
I don't necessarily disagree, but I'm curious as to what you hope to
gain.

Thanks,
NeilBrown

> 
> On server side the support has been off, by default, 
> since 2013 (6b4e4965a6b). With this server patch the
> ability to enable v2 will be remove.
> 
> Currently even with CONFIG_NFS_V2 not set
> v2 mounts are still tied (over-the-wire). I looked at creating 
> a kernel parameter module so support could re-enabled 
> but that got ugly quick.
> 
> So I just decided to make all V2 mounts fail with
> EOPNOTSUPP, with no way of turn them back on.
> 
> Steve Dickson (3):
>   nfsd: Remove the ability to enable NFS v2.
>   nfs.man: Remove references to NFS v2 from the man pages
>   mount: Remove NFS v2 support from mount.nfs
> 
>  nfs.conf                  |  1 -
>  utils/mount/configfile.c  |  2 +-
>  utils/mount/mount.nfs.man |  2 +-
>  utils/mount/network.c     |  4 ++--
>  utils/mount/nfs.man       | 20 +++-----------------
>  utils/mount/nfsmount.conf |  2 +-
>  utils/mount/stropts.c     |  3 +++
>  utils/nfsd/nfsd.c         |  2 --
>  utils/nfsd/nfsd.man       |  4 ++--
>  9 files changed, 13 insertions(+), 27 deletions(-)
> 
> -- 
> 2.31.1
> 
> 

Re: [PATCH RFC 0/3] Remove NFS v2 support from the client and server

[Steve Dickson]

Hey!

On 11/29/21 15:38, NeilBrown wrote:
> On Tue, 30 Nov 2021, Steve Dickson wrote:
>> These patches will remove the all references and
>> support of NFS v2 in both the server and client.
> 
> What is the motivation for this?
> I don't necessarily disagree, but I'm curious as to what you hope to
> gain.
Just to eliminate v2 support once and for all...
It is a dead version, IMHO, so I'm just trying
to clean things up by remove it from the man pages
and error out (on the client), if a v2 mount is tried...

We are coming out with a major fairly soon, so
I'm just trying make it clear v2 is no longer
an option... So I wanted to more eyes on what
we are thinking of doing.

steved.

> 
> Thanks,
> NeilBrown
> 
>>
>> On server side the support has been off, by default,
>> since 2013 (6b4e4965a6b). With this server patch the
>> ability to enable v2 will be remove.
>>
>> Currently even with CONFIG_NFS_V2 not set
>> v2 mounts are still tied (over-the-wire). I looked at creating
>> a kernel parameter module so support could re-enabled
>> but that got ugly quick.
>>
>> So I just decided to make all V2 mounts fail with
>> EOPNOTSUPP, with no way of turn them back on.
>>
>> Steve Dickson (3):
>>    nfsd: Remove the ability to enable NFS v2.
>>    nfs.man: Remove references to NFS v2 from the man pages
>>    mount: Remove NFS v2 support from mount.nfs
>>
>>   nfs.conf                  |  1 -
>>   utils/mount/configfile.c  |  2 +-
>>   utils/mount/mount.nfs.man |  2 +-
>>   utils/mount/network.c     |  4 ++--
>>   utils/mount/nfs.man       | 20 +++-----------------
>>   utils/mount/nfsmount.conf |  2 +-
>>   utils/mount/stropts.c     |  3 +++
>>   utils/nfsd/nfsd.c         |  2 --
>>   utils/nfsd/nfsd.man       |  4 ++--
>>   9 files changed, 13 insertions(+), 27 deletions(-)
>>
>> -- 
>> 2.31.1
>>
>>
> 

Re: [PATCH RFC 0/3] Remove NFS v2 support from the client and server

[J. Bruce Fields]

On Mon, Nov 29, 2021 at 02:27:28PM -0500, Steve Dickson wrote:
> These patches will remove the all references and 
> support of NFS v2 in both the server and client.
> 
> On server side the support has been off, by default, 
> since 2013 (6b4e4965a6b). With this server patch the
> ability to enable v2 will be remove.
> 
> Currently even with CONFIG_NFS_V2 not set
> v2 mounts are still tied (over-the-wire).

So the client is running a kernel built with CONFIG_NFS_V2 not set, and
you're still seeing it send NFSv2 calls?

That's very weird.

> I looked at creating a kernel parameter module so support could
> re-enabled but that got ugly quick.

I don't think there's much point to a module parameter.

One other thing we might want to do is provide a way for distros to
configure out support on the server side too.  That'd help confirm that
people really aren't using it before we tear it out completely.

E.g., untested, and should probably remove more than this, but as a
start:

diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig
index 3d1d17256a91..7b9e9afc5fcb 100644
--- a/fs/nfsd/Kconfig
+++ b/fs/nfsd/Kconfig
@@ -35,6 +35,16 @@ config NFSD_V2_ACL
 	bool
 	depends on NFSD
 
+config NFSD_V2
+	bool "NFS server support for NFS version 2"
+	depends on NFSD
+	help
+	  This option enables server support for version 2 of the NFS
+	  protocol.  This version has significant limitations and is no
+	  longer widely used.
+
+	  If unsure, say N.
+
 config NFSD_V3
 	bool "NFS server support for NFS version 3"
 	depends on NFSD
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 80431921e5d7..09c376063ff0 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -116,7 +116,9 @@ static struct svc_stat	nfsd_acl_svcstats = {
 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
 
 static const struct svc_version *nfsd_version[] = {
+#if defined(CONFIG_NFSD_V2)
 	[2] = &nfsd_version2,
+#endif
 #if defined(CONFIG_NFSD_V3)
 	[3] = &nfsd_version3,
 #endif