1 files changed, 40 insertions, 0 deletions
diff --git a/tests/cp/sparse-perf.sh b/tests/cp/sparse-perf.sh
new file mode 100755
index 0000000..793ecee
--- /dev/null
+++ b/tests/cp/sparse-perf.sh
@@ -0,0 +1,40 @@
+#!/bin/sh
+# ensure that a sparse file is copied efficiently, by default
+
+# Copyright (C) 2021-2023 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ cp
+
+# Create a large-but-sparse file.
+timeout 10 truncate -s1T f ||
+  skip_ "unable to create a 1 TiB sparse file"
+
+# Note zfs with zfs_dmu_offset_next_sync=0 (the default)
+# will generally skip here, due to needing about 5 seconds
+# between the creation of the file and the use of SEEK_DATA,
+# for it to determine it's an empty file (return ENXIO).
+seek_data_capable_ f ||
+  skip_ "insufficient SEEK_DATA support"
+
+# Nothing can read that many bytes in so little time.
+timeout 10 cp --reflink=never f f2 || fail=1
+
+# Ensure that the sparse file copied through SEEK_DATA has the same size
+# in bytes as the original.
+test "$(stat --printf %s f)" = "$(stat --printf %s f2)" || fail=1
+
+Exit $fail