diff --git a/module/zfs/zfs_ctldir.c b/module/zfs/zfs_ctldir.c
index 4fa530b6c..168f853f1 100644
--- a/module/zfs/zfs_ctldir.c
+++ b/module/zfs/zfs_ctldir.c
@@ -732,7 +732,11 @@ zfsctl_unmount_snapshot(zfs_sb_t *zsb, char *name, int flags)
 	sep = avl_find(&zsb->z_ctldir_snaps, &search, NULL);
 	if (sep) {
 		avl_remove(&zsb->z_ctldir_snaps, sep);
+		mutex_exit(&zsb->z_ctldir_lock);
+
 		error = __zfsctl_unmount_snapshot(sep, flags);
+
+		mutex_enter(&zsb->z_ctldir_lock);
 		if (error == EBUSY)
 			avl_add(&zsb->z_ctldir_snaps, sep);
 		else
@@ -767,7 +771,11 @@ zfsctl_unmount_snapshots(zfs_sb_t *zsb, int flags, int *count)
 	while (sep != NULL) {
 		next = AVL_NEXT(&zsb->z_ctldir_snaps, sep);
 		avl_remove(&zsb->z_ctldir_snaps, sep);
+		mutex_exit(&zsb->z_ctldir_lock);
+
 		error = __zfsctl_unmount_snapshot(sep, flags);
+
+		mutex_enter(&zsb->z_ctldir_lock);
 		if (error == EBUSY) {
 			avl_add(&zsb->z_ctldir_snaps, sep);
 			(*count)++;