git: a43b61a1ba45 - stable/15 - makefs: Allow "legacy" as a valid ZFS mountpoint

The branch stable/15 has been updated by jlduran:

URL: https://cgit.FreeBSD.org/src/commit/?id=a43b61a1ba453c95018c0cb0042f823863e3ac69

commit a43b61a1ba453c95018c0cb0042f823863e3ac69
Author:     Jose Luis Duran <[email protected]>
AuthorDate: 2026-08-11 22:34:16 +0000
Commit:     Jose Luis Duran <[email protected]>
CommitDate: 2026-08-18 00:30:35 +0000

    makefs: Allow "legacy" as a valid ZFS mountpoint
    
    Allow "legacy" alongside "none" as a valid value for the ZFS mountpoint
    property, matching zfsprops(7).
    
    Reviewed by:    imp, markj
    MFC after:      1 week
    Differential Revision:  https://reviews.freebsd.org/D58781
    
    (cherry picked from commit 59d6422d6f21fd5cf4709ce9fcada54d3925a4f6)
---
 usr.sbin/makefs/tests/makefs_zfs_tests.sh | 39 +++++++++++++++++++++++++++++++
 usr.sbin/makefs/zfs/dsl.c                 |  5 ++--
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/usr.sbin/makefs/tests/makefs_zfs_tests.sh b/usr.sbin/makefs/tests/makefs_zfs_tests.sh
index 0a6e5597499f..5b6c701ca291 100644
--- a/usr.sbin/makefs/tests/makefs_zfs_tests.sh
+++ b/usr.sbin/makefs/tests/makefs_zfs_tests.sh
@@ -654,6 +654,44 @@ multi_dataset_4_cleanup()
 	common_cleanup
 }
 
+#
+# Create a legacy dataset.
+#
+atf_test_case multi_dataset_5 cleanup
+multi_dataset_5_body()
+{
+	create_test_dirs
+	cd $TEST_INPUTS_DIR
+
+	mkdir dir1
+	echo a > dir1/a
+
+	cd -
+
+	atf_check $MAKEFS -s 1g -o rootpath=/ -o poolname=$ZFS_POOL_NAME \
+	    -o fs=${ZFS_POOL_NAME}/dir1\;canmount=noauto\;mountpoint=legacy \
+	    $TEST_IMAGE $TEST_INPUTS_DIR
+
+	import_image
+
+	atf_check -o inline:legacy\\n \
+	    zfs list -H -o mountpoint ${ZFS_POOL_NAME}/dir1
+
+	check_image_contents
+
+	atf_check zfs set mountpoint=/dir1 ${ZFS_POOL_NAME}/dir1
+	atf_check zfs mount ${ZFS_POOL_NAME}/dir1
+	atf_check -o inline:${TEST_MOUNT_DIR}/dir1\\n \
+	    zfs list -H -o mountpoint ${ZFS_POOL_NAME}/dir1
+
+	# dir1/a should be part of the root dataset, not dir1.
+	atf_check -s not-exit:0 -e not-empty stat ${TEST_MOUNT_DIR}/dir1/a
+}
+multi_dataset_5_cleanup()
+{
+	common_cleanup
+}
+
 #
 # Validate handling of multiple staging directories.
 #
@@ -1043,6 +1081,7 @@ atf_init_test_cases()
 	atf_add_test_case multi_dataset_2
 	atf_add_test_case multi_dataset_3
 	atf_add_test_case multi_dataset_4
+	atf_add_test_case multi_dataset_5
 	atf_add_test_case multi_staging_1
 	atf_add_test_case multi_staging_2
 	atf_add_test_case reproducible
diff --git a/usr.sbin/makefs/zfs/dsl.c b/usr.sbin/makefs/zfs/dsl.c
index 7a634272b7d4..8c336131cea0 100644
--- a/usr.sbin/makefs/zfs/dsl.c
+++ b/usr.sbin/makefs/zfs/dsl.c
@@ -103,7 +103,8 @@ dsl_dir_get_mountpoint(zfs_opt_t *zfs, zfs_dsl_dir_t *dir)
 	char *mountpoint;
 
 	if (nvlist_find_string(dir->propsnv, "mountpoint", &mountpoint) == 0) {
-		if (strcmp(mountpoint, "none") == 0)
+		if (strcmp(mountpoint, "none") == 0 ||
+		    strcmp(mountpoint, "legacy") == 0)
 			return (NULL);
 	} else {
 		/*
@@ -165,7 +166,7 @@ dsl_dir_set_prop(zfs_opt_t *zfs, zfs_dsl_dir_t *dir, const char *key,
 		errx(1, "property `%s' already set", key);
 
 	if (strcmp(key, "mountpoint") == 0) {
-		if (strcmp(val, "none") != 0) {
+		if (strcmp(val, "none") != 0 && strcmp(val, "legacy") != 0) {
 			if (val[0] != '/')
 				errx(1, "mountpoint `%s' is not absolute", val);
 			if (strcmp(val, zfs->rootpath) != 0 &&