It is possible to recursively destroy snapshots even if the snapshot

doesn't exist on a dataset we are starting from. For example if we
have the following configuration:

	tank
	tank/foo
	tank/foo@snap
	tank/bar
	tank/bar@snap

We can execute:

	# zfs destroy -t tank@snap

eventhough tank@snap doesn't exit.

Unfortunately it is not possible to do the same with recursive rename:

	# zfs rename -r tank@snap tank@pans
	cannot open 'tank@snap': dataset does not exist

...until now. This change allows to recursively rename snapshots even if
snapshot doesn't exist on the starting dataset.

Sponsored by:	rsync.net
MFC after:	2 weeks

1 files changed, 15 insertions, 1 deletions

diff --git a/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c b/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
index e0bc3d7..ea313ba 100644
--- a/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
+++ b/cddl/contrib/opensolaris/cmd/zfs/zfs_main.c
@@ -3081,6 +3081,7 @@ zfs_do_rename(int argc, char **argv)
 	int ret = 0;
 	int types;
 	boolean_t parents = B_FALSE;
+	char *snapshot = NULL;
 
 	/* check options */
 	while ((c = getopt(argc, argv, "fpru")) != -1) {
@@ -3149,6 +3150,19 @@ zfs_do_rename(int argc, char **argv)
 	else
 		types = ZFS_TYPE_DATASET;
 
+	if (flags.recurse) {
+		/*
+		 * When we do recursive rename we are fine when the given
+		 * snapshot for the given dataset doesn't exist - it can
+		 * still exists below.
+		 */
+
+		snapshot = strchr(argv[0], '@');
+		assert(snapshot != NULL);
+		*snapshot = '\0';
+		snapshot++;
+	}
+
 	if ((zhp = zfs_open(g_zfs, argv[0], types)) == NULL)
 		return (1);
 
@@ -3159,7 +3173,7 @@ zfs_do_rename(int argc, char **argv)
 		return (1);
 	}
 
-	ret = (zfs_rename(zhp, argv[1], flags) != 0);
+	ret = (zfs_rename(zhp, snapshot, argv[1], flags) != 0);
 
 	zfs_close(zhp);
 	return (ret);