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 

1 files changed, 29 insertions, 19 deletions

diff --git a/cmd/zfs/zfs_main.c b/cmd/zfs/zfs_main.c
index 76c82fd53..9939f206a 100644
--- a/cmd/zfs/zfs_main.c
+++ b/cmd/zfs/zfs_main.c
@@ -339,7 +339,7 @@ get_usage(zfs_help_t idx)
 		    "\tsend [-nVvPe] -t <receive_resume_token>\n"
 		    "\tsend [-PnVv] --saved filesystem\n"));
 	case HELP_SET:
-		return (gettext("\tset <property=value> ... "
+		return (gettext("\tset [-u] <property=value> ... "
 		    "<filesystem|volume|snapshot> ...\n"));
 	case HELP_SHARE:
 		return (gettext("\tshare [-l] <-a [nfs|smb] | filesystem>\n"));
@@ -4206,8 +4206,8 @@ out:
 static int
 set_callback(zfs_handle_t *zhp, void *data)
 {
-	nvlist_t *props = data;
-	int ret = zfs_prop_set_list(zhp, props);
+	zprop_set_cbdata_t *cb = data;
+	int ret = zfs_prop_set_list_flags(zhp, cb->cb_proplist, cb->cb_flags);
 
 	if (ret != 0 || libzfs_errno(g_zfs) != EZFS_SUCCESS) {
 		switch (libzfs_errno(g_zfs)) {
@@ -4227,25 +4227,35 @@ set_callback(zfs_handle_t *zhp, void *data)
 static int
 zfs_do_set(int argc, char **argv)
 {
-	nvlist_t *props = NULL;
+	zprop_set_cbdata_t cb = { 0 };
 	int ds_start = -1; /* argv idx of first dataset arg */
 	int ret = 0;
-	int i;
+	int i, c;
 
-	/* check for options */
-	if (argc > 1 && argv[1][0] == '-') {
-		(void) fprintf(stderr, gettext("invalid option '%c'\n"),
-		    argv[1][1]);
-		usage(B_FALSE);
+	/* check options */
+	while ((c = getopt(argc, argv, "u")) != -1) {
+		switch (c) {
+		case 'u':
+			cb.cb_flags |= ZFS_SET_NOMOUNT;
+			break;
+		case '?':
+		default:
+			(void) fprintf(stderr, gettext("invalid option '%c'\n"),
+			    optopt);
+			usage(B_FALSE);
+		}
 	}
 
+	argc -= optind;
+	argv += optind;
+
 	/* check number of arguments */
-	if (argc < 2) {
+	if (argc < 1) {
 		(void) fprintf(stderr, gettext("missing arguments\n"));
 		usage(B_FALSE);
 	}
-	if (argc < 3) {
-		if (strchr(argv[1], '=') == NULL) {
+	if (argc < 2) {
+		if (strchr(argv[0], '=') == NULL) {
 			(void) fprintf(stderr, gettext("missing property=value "
 			    "argument(s)\n"));
 		} else {
@@ -4256,7 +4266,7 @@ zfs_do_set(int argc, char **argv)
 	}
 
 	/* validate argument order:  prop=val args followed by dataset args */
-	for (i = 1; i < argc; i++) {
+	for (i = 0; i < argc; i++) {
 		if (strchr(argv[i], '=') != NULL) {
 			if (ds_start > 0) {
 				/* out-of-order prop=val argument */
@@ -4274,20 +4284,20 @@ zfs_do_set(int argc, char **argv)
 	}
 
 	/* Populate a list of property settings */
-	if (nvlist_alloc(&props, NV_UNIQUE_NAME, 0) != 0)
+	if (nvlist_alloc(&cb.cb_proplist, NV_UNIQUE_NAME, 0) != 0)
 		nomem();
-	for (i = 1; i < ds_start; i++) {
-		if (!parseprop(props, argv[i])) {
+	for (i = 0; i < ds_start; i++) {
+		if (!parseprop(cb.cb_proplist, argv[i])) {
 			ret = -1;
 			goto error;
 		}
 	}
 
 	ret = zfs_for_each(argc - ds_start, argv + ds_start, 0,
-	    ZFS_TYPE_DATASET, NULL, NULL, 0, set_callback, props);
+	    ZFS_TYPE_DATASET, NULL, NULL, 0, set_callback, &cb);
 
 error:
-	nvlist_free(props);
+	nvlist_free(cb.cb_proplist);
 	return (ret);
 }