cp --reflink: add an "auto" parameter to fall back to a normal copy

* doc/coreutils.texi (cp invocation): Document the new
"auto" and "always" options to --reflink.
* src/copy.c (copy_reg): Fall back to a standard copy
when reflink() is not supported and --reflink=auto specified.
* src/copy.h [struct cp_options] (reflink): Change type s/bool/enum/.
* src/cp.c (usage): Describe the --reflink={always,auto} options
and expand a little on what --reflink does.
(main): parse the new parameters to --reflink and allow all
--sparse options with --reflink=auto.
* src/install.c (cp_option_init): Init the enum instead of bool.
* src/mv.c (cp_option_init): Likewise.
* tests/cp/reflink-auto: A new test for falling back to normal copy.
* tests/Makefile.am: Reference the new test.
* NEWS: Mention the new feature.

1 files changed, 45 insertions, 0 deletions

diff --git a/tests/cp/reflink-auto b/tests/cp/reflink-auto
new file mode 100755
index 000000000..ff2b1b39b
--- /dev/null
+++ b/tests/cp/reflink-auto
@@ -0,0 +1,45 @@
+#!/bin/sh
+# Test cp --reflink=auto
+
+# Copyright (C) 2009 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 <http://www.gnu.org/licenses/>.
+
+if test "$VERBOSE" = yes; then
+  set -x
+  cp --version
+fi
+
+. $srcdir/test-lib.sh
+
+cleanup_() { rm -rf "$other_partition_tmpdir"; }
+. "$abs_srcdir/other-fs-tmpdir"
+a_other="$other_partition_tmpdir/a"
+rm -f $a_other || framework_failure
+
+echo non_zero_size > "$a_other"
+
+# we shouldn't be able to reflink() files on separate partitions
+cp --reflink      "$a_other" b && fail=1
+
+# --reflink=auto should fall back to a normal copy
+cp --reflink=auto "$a_other" b || fail=1
+test -s b || fail=1
+
+# --reflink=auto should allow --sparse for fallback copies.
+# This command can be used to create minimal sized copies.
+cp --reflink=auto --sparse=always "$a_other" b || fail=1
+test -s b || fail=1
+
+Exit $fail