This patch enables using the macOS 10.12+ clonefile(2) system call for
reflinking on supported filesystems. The system BSD cp(1) only
supports -c (--reflink=always), which is quite a pain.
Tested on a hackintosh machine with macOS 10.15. And yes, this is a
resubmission.
---
configure.ac | 14 ++++++++++++++
src/copy.c | 45 ++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 58 insertions(+), 1 deletion(-)
diff --git a/configure.ac b/configure.ac
index 69d4e7d..07ad5c1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -362,6 +362,20 @@ case $utils_cv_func_setpriority,$ac_cv_func_nice in
gl_ADD_PROG([optional_bin_progs], [nice])
esac
+AC_CACHE_CHECK([for clonefile],
+ [utils_cv_func_clonefile],
+ [AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <sys/attr.h>
+ #include <sys/clonefile.h>
+ ]],
+ [[clonefile("", "", CLONE_NOFOLLOW);]])],
+ [utils_cv_func_clonefile=yes],
+ [utils_cv_func_clonefile=no])])
+if test $utils_cv_func_clonefile = yes; then
+ AC_DEFINE([HAVE_CLONEFILE], [1], [Define if clonefile exists.])
+fi
+
if test "$cross_compiling" = yes || test -c /dev/stdin <.; then
AC_DEFINE([DEV_FD_MIGHT_BE_CHR], [1],
[Define to 1 if /dev/std{in,out,err} and /dev/fd/N, if they exist, might be
diff --git a/src/copy.c b/src/copy.c
index 4050f69..fad8189 100644
--- a/src/copy.c
+++ b/src/copy.c
@@ -73,6 +73,11 @@
# include "verror.h"
#endif
+#if HAVE_CLONEFILE
+# include <sys/attr.h>
+# include <sys/clonefile.h>
+#endif
+
#if HAVE_LINUX_FALLOC_H
# include <linux/falloc.h>
#endif
@@ -1311,12 +1316,48 @@ copy_reg (char const *src_name, char const *dst_name,
goto close_src_desc;
}
+#if HAVE_CLONEFILE
+ /* The macOS clonefile() syscall is like link in that it takes
+ pathnames. Do it first. */
+ if (data_copy_required && x->reflink_mode)
+ {
+ bool clone_ok = false;
+ if (! *new_dst)
+ {
+ if (unlink(dst_name) != 0)
+ {
+ error (0, errno, _("cannot remove %s"), quoteaf (dst_name));
+ goto noclone;
+ }
+ if (x->verbose)
+ printf (_("removed %s\n"), quoteaf (dst_name));
+ }
+ uint32_t cloneflags = 0;
+ if (x->dereference == DEREF_NEVER) cloneflags |= CLONE_NOFOLLOW;
+ /* CLONE_NOOWNERCOPY (0x0002) is recently added with no specific
+ * date. Let's not feed ourselves to Apple-versioning. */
+ clone_ok = clonefile (src_name, dst_name, cloneflags) == 0;
+ noclone:;
+ if (clone_ok || x->reflink_mode == REFLINK_ALWAYS)
+ {
+ if (!clone_ok)
+ {
+ error (0, errno, _("failed to clone %s from %s"),
+ quoteaf_n (0, dst_name), quoteaf_n (1, src_name));
+ return false;
+ }
+ data_copy_required = false;
+ *new_dst = false;
+ }
+ }
+#endif
+
/* The semantics of the following open calls are mandated
by the specs for both cp and mv. */
if (! *new_dst)
{
int open_flags =
- O_WRONLY | O_BINARY | (x->data_copy_required ? O_TRUNC : 0);
+ O_WRONLY | O_BINARY | (data_copy_required ? O_TRUNC : 0);
dest_desc = open (dst_name, open_flags);
dest_errno = errno;
@@ -1453,6 +1494,7 @@ copy_reg (char const *src_name, char const *dst_name,
goto close_src_and_dst_desc;
}
+#if ! HAVE_CLONEFILE
/* --attributes-only overrides --reflink. */
if (data_copy_required && x->reflink_mode)
{
@@ -1469,6 +1511,7 @@ copy_reg (char const *src_name, char const *dst_name,
data_copy_required = false;
}
}
+#endif
if (data_copy_required)
{
--
2.20.1.windows.1
