OpenZFS 6428 - set canmount=off on unmounted filesystem tries to unmount children

Authored by: Andriy Gapon <andriy.gapon@clusterhq.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Gordon Ross <gordon.w.ross@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Ported-by: George Melikov <mail@gmelikov.ru>
OpenZFS-issue: https://www.illumos.org/issues/6428
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/c079fa4
Closes #5628

diff --git a/lib/libzfs/libzfs_dataset.c b/lib/libzfs/libzfs_dataset.c
index d4f016660054a48c2aafc924bf2a4fc35377026b..240728f9637b90986938806f3ce41a36a0cf512c 100644 (file)
--- a/lib/libzfs/libzfs_dataset.c
+++ b/lib/libzfs/libzfs_dataset.c
@@ -1628,8 +1628,9 @@ zfs_prop_set_list(zfs_handle_t *zhp, nvlist_t *props)
                 * its canmount property to 'on' or 'noauto'.  We only use
                 * the changelist logic to unmount when setting canmount=off.
                 */
-               if (!(prop == ZFS_PROP_CANMOUNT &&
-                   fnvpair_value_uint64(elem) != ZFS_CANMOUNT_OFF)) {
+               if (prop != ZFS_PROP_CANMOUNT ||
+                   (fnvpair_value_uint64(elem) == ZFS_CANMOUNT_OFF &&
+                   zfs_is_mounted(zhp, NULL))) {
                        cls[cl_idx] = changelist_gather(zhp, prop, 0, 0);
                        if (cls[cl_idx] == NULL)
                                goto error;