[PATCH] nfs_lib: Skip NFS versions disabled on server

From: Avinesh Kumar <avinesh.kumar-IBi9RG/[email protected]>

nfs06.sh mount several NFS versions in a single run
(e.g. "3,4.0,4.1,4.2"). If the server has disabled one of
the requested versions (reported via /proc/fs/nfsd/versions),
the whole test currently aborts with TBROK on the failed mount
instead of continuing with the versions that are supported.

nfs06 1 TINFO: setup NFSv4.0, socket type tcp
nfs06 1 TINFO: Mounting /var/tmp/LTP_nfs06.GHDqCwPYES/4.0/1
nfs06 1 TINFO: Mounting NFS: mount -v -t nfs -o proto=tcp,vers=4.0 10.0.0.2:/var/tmp/LTP_nfs06.GHDqCwPYES/mntpoint/4.0/tcp /var/tmp/LTP_nfs06.GHDqCwPYES/4.0/1
mount.nfs: mount(2): Invalid argument
mount.nfs: an incorrect mount option was specified for /var/tmp/LTP_nfs06.GHDqCwPYES/4.0/1
mount.nfs: timeout set for Wed Aug  5 08:06:38 2026
mount.nfs: trying text-based options 'proto=tcp,vers=4.0,addr=10.0.0.2,clientaddr=10.0.0.1'
nfs06 1 TBROK: mount command failed

Add nfs_server_vers_enabled() to check /proc/fs/nfsd/versions on the
server, and nfs_filter_versions() to drop disabled versions from
$VERSION (keeping $SOCKET_TYPE aligned by position) before mounting.
If none of the requested versions are enabled, TCONF as before.

Signed-off-by: Avinesh Kumar <avinesh.kumar-IBi9RG/[email protected]>
---
 testcases/network/nfs/nfs_stress/nfs_lib.sh | 56 ++++++++++++++++++++-
 1 file changed, 54 insertions(+), 2 deletions(-)

diff --git a/testcases/network/nfs/nfs_stress/nfs_lib.sh b/testcases/network/nfs/nfs_stress/nfs_lib.sh
index 8bff3f23ae12..4065b000467e 100644
--- a/testcases/network/nfs/nfs_stress/nfs_lib.sh
+++ b/testcases/network/nfs/nfs_stress/nfs_lib.sh
@@ -55,19 +55,24 @@ TST_NEEDS_DRIVERS="nfsd"
 # debugging whether test failures are related to veth/netns).
 LTP_NFS_NETNS_USE_LO=${LTP_NFS_NETNS_USE_LO:-}
 
-get_socket_type()
+get_socket_type_raw()
 {
 	local t
 	local k=0
 	for t in $SOCKET_TYPE; do
 		if [ "$k" -eq "$1" ]; then
-			echo "${t}${TST_IPV6}"
+			echo "$t"
 			return
 		fi
 		k=$(( k + 1 ))
 	done
 }
 
+get_socket_type()
+{
+	echo "$(get_socket_type_raw "$1")${TST_IPV6}"
+}
+
 # directory mounted by NFS client
 get_local_dir()
 {
@@ -109,6 +114,51 @@ nfs_server_udp_enabled()
 	tst_rhost_run -c "grep -q \"^[# ]*udp *= *y\" /etc/nfs.conf $config"
 }
 
+# nfs_server_vers_enabled VERS
+# Only returns false (1) when the server explicitly lists "-VERS" in
+# /proc/fs/nfsd/versions. If that file is unavailable or doesn't mention
+# VERS at all, defaults to true so the mount is still attempted.
+nfs_server_vers_enabled()
+{
+	local vers="$1"
+	local versions=" $(tst_rhost_run -c 'cat /proc/fs/nfsd/versions 2>/dev/null') "
+
+	case "$versions" in
+	*" -$vers "*) return 1;;
+	esac
+
+	return 0
+}
+
+# Drops NFS versions the server explicitly disabled from $VERSION, keeping
+# $SOCKET_TYPE entries aligned by position with what remains.
+nfs_filter_versions()
+{
+	local v type
+	local n=0
+	local new_version=
+	local new_socket_type=
+
+	for v in $VERSION; do
+		type=$(get_socket_type_raw $n)
+
+		if nfs_server_vers_enabled "$v"; then
+			new_version="$new_version $v"
+			new_socket_type="$new_socket_type $type"
+		else
+			tst_res TINFO "NFSv$v disabled on server, skipping"
+		fi
+
+		n=$(( n + 1 ))
+	done
+
+	[ -z "$new_version" ] && \
+		tst_brk TCONF "none of the requested NFS versions ($VERSION) are enabled on server"
+
+	VERSION="${new_version# }"
+	SOCKET_TYPE="${new_socket_type# }"
+}
+
 nfs_setup_server()
 {
 	local remote_dir="$1"
@@ -198,6 +248,8 @@ nfs_setup()
 
 	tst_res TINFO "$(mount.nfs -V)"
 
+	nfs_filter_versions
+
 	for i in $VERSION; do
 		type=$(get_socket_type $n)
 		tst_res TINFO "setup NFSv$i, socket type $type"
-- 
2.55.0


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