Linux 7.0: explicitly set setlease handler to kernel implementation

The upcoming 7.0 kernel will no longer fall back to generic_setlease(),
instead returning EINVAL if .setlease is NULL. So, we set it explicitly.

To ensure that we catch any future kernel change, adds a sanity test for
F_SETLEASE and F_GETLEASE too. Since this is a Linux-specific test,
also a small adjustment to the test runner to allow OS-specific helper
programs.

Sponsored-by: TrueNAS
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@truenas.com>
Closes #18215

config/kernel-filelock.m4

@@ -0,0 +1,23 @@
+dnl # SPDX-License-Identifier: CDDL-1.0
+dnl #
+dnl # 6.3 API change
+dnl # locking support functions (eg generic_setlease) were moved out of
+dnl # linux/fs.h to linux/filelock.h
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_SRC_FILELOCK_HEADER], [
+	ZFS_LINUX_TEST_SRC([filelock_header], [
+		#include <linux/fs.h>
+		#include <linux/filelock.h>
+	], [])
+])
+
+AC_DEFUN([ZFS_AC_KERNEL_FILELOCK_HEADER], [
+	AC_MSG_CHECKING([for standalone filelock header])
+	ZFS_LINUX_TEST_RESULT([filelock_header], [
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_FILELOCK_HEADER, 1, [linux/filelock.h exists])
+	], [
+		AC_MSG_RESULT(no)
+	])
+])
+

config/kernel.m4

@@ -141,6 +141,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_SRC], [
 	ZFS_AC_KERNEL_SRC_NAMESPACE
 	ZFS_AC_KERNEL_SRC_INODE_GENERIC_DROP
 	ZFS_AC_KERNEL_SRC_KASAN_ENABLED
+	ZFS_AC_KERNEL_SRC_FILELOCK_HEADER
 	case "$host_cpu" in
 		powerpc*)
 			ZFS_AC_KERNEL_SRC_CPU_HAS_FEATURE
@@ -265,6 +266,7 @@ AC_DEFUN([ZFS_AC_KERNEL_TEST_RESULT], [
 	ZFS_AC_KERNEL_NAMESPACE
 	ZFS_AC_KERNEL_INODE_GENERIC_DROP
 	ZFS_AC_KERNEL_KASAN_ENABLED
+	ZFS_AC_KERNEL_FILELOCK_HEADER
 	case "$host_cpu" in
 		powerpc*)
 			ZFS_AC_KERNEL_CPU_HAS_FEATURE

module/os/linux/zfs/zpl_file.c

@@ -43,6 +43,9 @@
 #ifdef HAVE_VFS_FILEMAP_DIRTY_FOLIO
 #include <linux/writeback.h>
 #endif
+#ifdef HAVE_FILELOCK_HEADER
+#include <linux/filelock.h>
+#endif
 
 /*
  * When using fallocate(2) to preallocate space, inflate the requested
@@ -1242,6 +1245,7 @@ const struct file_operations zpl_file_operations = {
 	.mmap		= zpl_mmap,
 	.fsync		= zpl_fsync,
 	.fallocate	= zpl_fallocate,
+	.setlease	= generic_setlease,
 	.copy_file_range	= zpl_copy_file_range,
 #ifdef HAVE_VFS_CLONE_FILE_RANGE
 	.clone_file_range	= zpl_clone_file_range,

scripts/zfs-tests.sh

@@ -294,6 +294,16 @@ constrain_path() {
 	SYSTEM_DIRS="/usr/local/bin /usr/local/sbin"
 	SYSTEM_DIRS="$SYSTEM_DIRS /usr/bin /usr/sbin /bin /sbin $LIBEXEC_DIR"
 
+	SYSTEM_FILES="$SYSTEM_FILES_COMMON"
+	ZFSTEST_FILES="$ZFSTEST_FILES_COMMON"
+	if [ "$UNAME" = "FreeBSD" ] ; then
+		SYSTEM_FILES="$SYSTEM_FILES $SYSTEM_FILES_FREEBSD"
+		ZFSTEST_FILES="$ZFSTEST_FILES $ZFSTEST_FILES_FREEBSD"
+	else
+		SYSTEM_FILES="$SYSTEM_FILES $SYSTEM_FILES_LINUX"
+		ZFSTEST_FILES="$ZFSTEST_FILES $ZFSTEST_FILES_LINUX"
+	fi
+
 	if [ "$INTREE" = "yes" ]; then
 		# Constrained path set to $(top_builddir)/tests/zfs-tests/bin
 		STF_PATH="$BIN_DIR"
@@ -326,12 +336,6 @@ constrain_path() {
 	fi
 
 	# Standard system utilities
-	SYSTEM_FILES="$SYSTEM_FILES_COMMON"
-	if [ "$UNAME" = "FreeBSD" ] ; then
-		SYSTEM_FILES="$SYSTEM_FILES $SYSTEM_FILES_FREEBSD"
-	else
-		SYSTEM_FILES="$SYSTEM_FILES $SYSTEM_FILES_LINUX"
-	fi
 	create_links "$SYSTEM_DIRS" "$SYSTEM_FILES"
 
 	# Exceptions

tests/runfiles/linux.run

@@ -141,6 +141,10 @@ pre =
 post =
 tags = ['functional', 'largest_pool']
 
+[tests/functional/lease:Linux]
+tests = ['lease_setlease']
+tags = ['functional', 'lease']
+
 [tests/functional/longname:Linux]
 tests = ['longname_001_pos', 'longname_002_pos', 'longname_003_pos']
 tags = ['functional', 'longname']

tests/zfs-tests/cmd/.gitignore

@@ -58,3 +58,4 @@
 /sha2_test
 /idmap_util
 /statx
+/setlease

tests/zfs-tests/cmd/Makefile.am

@@ -130,6 +130,7 @@ scripts_zfs_tests_bin_PROGRAMS += %D%/statx
 scripts_zfs_tests_bin_PROGRAMS += %D%/xattrtest
 scripts_zfs_tests_bin_PROGRAMS += %D%/zed_fd_spill-zedlet
 scripts_zfs_tests_bin_PROGRAMS += %D%/idmap_util
+scripts_zfs_tests_bin_PROGRAMS += %D%/setlease
 
 %C%_idmap_util_LDADD = libspl.la
 

tests/zfs-tests/cmd/setlease.c

@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: CDDL-1.0
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2026, TrueNAS.
+ */
+
+/*
+ * This is a sanity check test for the F_SETLEASE and F_GETLEASE fcntl() calls.
+ * We use the generic kernel implementation, but we want to be alerted if it
+ * ever breaks.
+ *
+ * This is not a comprehensive test. It would be nice if it could be!
+ */
+
+#ifndef _GNU_SOURCE
+#define	_GNU_SOURCE
+#endif
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+
+static int
+get_lease(int fd) {
+	int r = fcntl(fd, F_GETLEASE);
+	if (r < 0) {
+		perror("fcntl(GETLEASE)");
+		exit(2);
+	}
+	return (r);
+}
+
+static int
+set_lease(int fd, int lease) {
+	return (fcntl(fd, F_SETLEASE, lease) < 0 ? errno : 0);
+}
+
+static const char *lease_str[] = {
+	[F_RDLCK] = "RDLCK",
+	[F_WRLCK] = "WRLCK",
+	[F_UNLCK] = "UNLCK",
+};
+
+static void
+assert_lease(int fd, int expect) {
+	int got = get_lease(fd);
+	if (got != expect) {
+		fprintf(stderr, "ASSERT_LEASE: expected %s [%d], got %s [%d]\n",
+		    lease_str[expect], expect, lease_str[got], got);
+		abort();
+	}
+	printf("ok: lease is %s\n", lease_str[got]);
+}
+
+static void
+assert_set_lease(int fd, int lease) {
+	int err = set_lease(fd, lease);
+	if (err != 0) {
+		fprintf(stderr, "ASSERT_SET_LEASE: tried %s [%d], error: %s\n",
+		    lease_str[lease], lease, strerror(err));
+		abort();
+	}
+	printf("ok: set lease to %s\n", lease_str[lease]);
+}
+
+int
+main(int argc, char **argv)
+{
+	if (argc != 2) {
+		fprintf(stderr, "usage: %s <filename>\n", argv[0]);
+		exit(1);
+	}
+
+	/* create and open file, read+write */
+	int fd = open(argv[1], O_CREAT|O_RDONLY, S_IRWXU|S_IRWXG|S_IRWXO);
+	if (fd < 0) {
+		perror("open");
+		exit(2);
+	}
+	printf("ok: opened file RDONLY\n");
+
+	/* fd starts with no lease */
+	assert_lease(fd, F_UNLCK);
+
+	/* fd is readonly, so can take read lease */
+	assert_set_lease(fd, F_RDLCK);
+	/* confirm read lease */
+	assert_lease(fd, F_RDLCK);
+
+	/* no other openers, so can take write lease */
+	assert_set_lease(fd, F_WRLCK);
+	/* confirm write lease */
+	assert_lease(fd, F_WRLCK);
+
+	/* release lease */
+	assert_set_lease(fd, F_UNLCK);
+	/* confirm lease released */
+	assert_lease(fd, F_UNLCK);
+
+	close(fd);
+
+	return (0);
+}

tests/zfs-tests/include/commands.cfg

@@ -182,7 +182,7 @@ export ZFS_FILES='zdb
     zfs_ids_to_path
     zpool_influxdb'
 
-export ZFSTEST_FILES='badsend
+export ZFSTEST_FILES_COMMON='badsend
     btree_test
     chg_usr_exec
     clonefile
@@ -241,3 +241,6 @@ export ZFSTEST_FILES='badsend
     zfs_diff-socket
     dosmode_readonly_write
     idmap_util'
+
+export ZFSTEST_FILES_LINUX='
+    setlease'

tests/zfs-tests/tests/Makefile.am

@@ -1658,6 +1658,9 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/io/psync.ksh \
 	functional/io/setup.ksh \
 	functional/io/sync.ksh \
+	functional/lease/cleanup.ksh \
+	functional/lease/lease_setlease.ksh \
+	functional/lease/setup.ksh \
 	functional/l2arc/cleanup.ksh \
 	functional/l2arc/l2arc_arcstats_pos.ksh \
 	functional/l2arc/l2arc_l2miss_pos.ksh \

tests/zfs-tests/tests/functional/lease/cleanup.ksh

@@ -0,0 +1,26 @@
+#!/bin/ksh -p
+# SPDX-License-Identifier: CDDL-1.0
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or https://opensource.org/licenses/CDDL-1.0.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+default_cleanup

tests/zfs-tests/tests/functional/lease/lease_setlease.ksh

@@ -0,0 +1,44 @@
+#!/bin/ksh -p
+# SPDX-License-Identifier: CDDL-1.0
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or https://opensource.org/licenses/CDDL-1.0.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2026, TrueNAS.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+verify_runnable "both"
+
+leasefile=/$TESTPOOL/leasefile
+
+function cleanup
+{
+	rm -f $leasefile
+}
+
+log_assert "F_SETLEASE is supported"
+log_onexit cleanup
+
+log_must setlease $leasefile
+
+log_pass "F_SETLEASE is supported"

tests/zfs-tests/tests/functional/lease/setup.ksh

@@ -0,0 +1,27 @@
+#!/bin/ksh -p
+# SPDX-License-Identifier: CDDL-1.0
+#
+# CDDL HEADER START
+#
+# The contents of this file are subject to the terms of the
+# Common Development and Distribution License (the "License").
+# You may not use this file except in compliance with the License.
+#
+# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+# or https://opensource.org/licenses/CDDL-1.0.
+# See the License for the specific language governing permissions
+# and limitations under the License.
+#
+# When distributing Covered Code, include this CDDL HEADER in each
+# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+# If applicable, add the following below this CDDL HEADER, with the
+# fields enclosed by brackets "[]" replaced with your own identifying
+# information: Portions Copyright [yyyy] [name of copyright owner]
+#
+# CDDL HEADER END
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+DISK=${DISKS%% *}
+default_setup $DISK