Add '-u' - nomount flag for zfs set

This commit adds '-u' flag for zfs set operation. With this flag,
mountpoint, sharenfs and sharesmb properties can be updated
without actually mounting or sharing the dataset.

Previously, if dataset was unmounted, and mountpoint property was
updated, dataset was not mounted after the update. This behavior
is changed in #15240. We mount the dataset whenever mountpoint
property is updated, regardless if it's mounted or not.

To provide the user with option to keep the dataset unmounted and
still update the mountpoint without mounting the dataset, '-u'
flag can be used.

If any of mountpoint, sharenfs or sharesmb properties are updated
with '-u' flag, the property is set to desired value but the
operation to (re/un)mount and/or (re/un)share the dataset is not
performed and dataset remains as it was before.

Reviewed-by: Alexander Motin <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Umer Saleem <[email protected]>
Closes #15322 

4 files changed, 106 insertions, 2 deletions

diff --git a/tests/runfiles/common.run b/tests/runfiles/common.run
index 342f56d50..ef787c65c 100644
--- a/tests/runfiles/common.run
+++ b/tests/runfiles/common.run
@@ -281,7 +281,7 @@ tests = ['cache_001_pos', 'cache_002_neg', 'canmount_001_pos',
     'user_property_004_pos', 'version_001_neg', 'zfs_set_001_neg',
     'zfs_set_002_neg', 'zfs_set_003_neg', 'property_alias_001_pos',
     'mountpoint_003_pos', 'ro_props_001_pos', 'zfs_set_keylocation',
-    'zfs_set_feature_activation']
+    'zfs_set_feature_activation', 'zfs_set_nomount']
 tags = ['functional', 'cli_root', 'zfs_set']
 
 [tests/functional/cli_root/zfs_share]
diff --git a/tests/runfiles/sanity.run b/tests/runfiles/sanity.run
index 449bf1c0f..ab41c05b8 100644
--- a/tests/runfiles/sanity.run
+++ b/tests/runfiles/sanity.run
@@ -212,7 +212,7 @@ tests = ['cache_001_pos', 'cache_002_neg', 'canmount_001_pos',
     'user_property_001_pos', 'user_property_003_neg', 'readonly_001_pos',
     'user_property_004_pos', 'version_001_neg',
     'zfs_set_003_neg', 'property_alias_001_pos',
-    'zfs_set_keylocation', 'zfs_set_feature_activation']
+    'zfs_set_keylocation', 'zfs_set_feature_activation', 'zfs_set_nomount']
 tags = ['functional', 'cli_root', 'zfs_set']
 
 [tests/functional/cli_root/zfs_snapshot]
diff --git a/tests/zfs-tests/tests/Makefile.am b/tests/zfs-tests/tests/Makefile.am
index 1a58e6f77..3272a5d58 100644
--- a/tests/zfs-tests/tests/Makefile.am
+++ b/tests/zfs-tests/tests/Makefile.am
@@ -870,6 +870,7 @@ nobase_dist_datadir_zfs_tests_tests_SCRIPTS += \
 	functional/cli_root/zfs_set/zfs_set_003_neg.ksh \
 	functional/cli_root/zfs_set/zfs_set_feature_activation.ksh \
 	functional/cli_root/zfs_set/zfs_set_keylocation.ksh \
+	functional/cli_root/zfs_set/zfs_set_nomount.ksh \
 	functional/cli_root/zfs_share/cleanup.ksh \
 	functional/cli_root/zfs_share/setup.ksh \
 	functional/cli_root/zfs_share/zfs_share_001_pos.ksh \
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_set/zfs_set_nomount.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_set/zfs_set_nomount.ksh
new file mode 100755
index 000000000..ebf087114
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_set/zfs_set_nomount.ksh
@@ -0,0 +1,103 @@
+#!/bin/ksh -p
+#
+# 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) 2023 by iXsystems, Inc. All rights reserved.
+#
+
+. $STF_SUITE/include/libtest.shlib
+. $STF_SUITE/tests/functional/cli_root/zfs_set/zfs_set_common.kshlib
+
+#
+# DESCRIPTION:
+# 'zfs set -u' should update the mountpoint, sharenfs and sharesmb
+# properties without mounting and sharing the dataset. Validate the
+# bevaior while dataset is mounted and unmounted.
+#
+# STRATEGY:
+# 1. Confirm dataset is currently mounted
+# 2. Update the mountpoint with -u flag
+# 3. Confirm mountpoint property is updated with new value
+# 4. Confirm dataset is still mounted at previous mountpoint
+# 5. Unmount the dataset
+# 6. Confirm dataset is unmounted
+# 7. Mount the dataset
+# 8. Confirm dataset is mounted at new mountpoint, that was set with -u flag.
+# 9. Update and mount the dataset at previous mountpoint.
+# 10. Unmount the dataset
+# 11. Update mountpoint property with zfs set -u
+# 12. Confirm dataset is not mounted
+# 13. Update sharenfs property with zfs set -u
+# 14. Confirm dataset is not mounted
+# 15. Update sharesmb property with zfs set -u
+# 16. Confirm dataset is not mounted
+# 17. Mount the dataset and confirm dataset is mounted at new mountpoint
+#
+
+verify_runnable "both"
+
+function cleanup
+{
+	log_must zfs set sharenfs=off $TESTPOOL/$TESTFS
+	if is_linux; then
+		log_must zfs set sharesmb=off $TESTPOOL/$TESTFS
+	fi
+	rm -r $newmpt
+}
+
+log_assert "'zfs set -u' sets the mountpoint and share properties without " \
+	"mounting the dataset"
+log_onexit cleanup
+
+oldmpt=$(get_prop mountpoint $TESTPOOL/$TESTFS)
+newmpt=$TEST_BASE_DIR/abc
+
+# Test while dataset is mounted
+log_must ismounted $TESTPOOL/$TESTFS
+log_must zfs set -u mountpoint=$newmpt $TESTPOOL/$TESTFS
+log_must check_user_prop $TESTPOOL/$TESTFS mountpoint $newmpt
+log_must eval "[[ "$(mount | grep $TESTPOOL/$TESTFS | awk '{print $3}')" == $oldmpt ]]"
+log_must zfs unmount $TESTPOOL/$TESTFS
+log_mustnot ismounted $TESTPOOL/$TESTFS
+log_must zfs mount $TESTPOOL/$TESTFS
+log_must eval "[[ "$(mount | grep $TESTPOOL/$TESTFS | awk '{print $3}')" == $newmpt ]]"
+
+# Test while dataset is unmounted
+log_must zfs set mountpoint=$oldmpt $TESTPOOL/$TESTFS
+log_must ismounted $TESTPOOL/$TESTFS
+log_must zfs unmount $TESTPOOL/$TESTFS
+log_must zfs set -u mountpoint=$newmpt $TESTPOOL/$TESTFS
+log_mustnot ismounted $TESTPOOL/$TESTFS
+log_must zfs set -u sharenfs=on $TESTPOOL/$TESTFS
+log_mustnot ismounted $TESTPOOL/$TESTFS
+if is_linux; then
+	log_must zfs set -u sharesmb=on $TESTPOOL/$TESTFS
+	log_mustnot ismounted $TESTPOOL/$TESTFS
+fi
+log_must zfs mount $TESTPOOL/$TESTFS
+log_must check_user_prop $TESTPOOL/$TESTFS mountpoint $newmpt
+log_must eval "[[ "$(mount | grep $TESTPOOL/$TESTFS | awk '{print $3}')" == $newmpt ]]"
+
+log_must zfs set mountpoint=$oldmpt $TESTPOOL/$TESTFS
+log_must ismounted $TESTPOOL/$TESTFS
+
+log_pass "'zfs set -u' functions correctly"