cp: optional --reflink support

function                                             old     new   delta
cp_main                                              428     512     +84
copy_file                                           1676    1742     +66

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/libbb/copy_file.c b/libbb/copy_file.c
index 1b8befd65..98bd4fe72 100644
--- a/libbb/copy_file.c
+++ b/libbb/copy_file.c
@@ -340,8 +340,27 @@ int FAST_FUNC copy_file(const char *source, const char *dest, int flags)
                         }
                 }
 #endif
+#if ENABLE_FEATURE_CP_REFLINK
+# undef BTRFS_IOCTL_MAGIC
+# define BTRFS_IOCTL_MAGIC 0x94
+# undef BTRFS_IOC_CLONE
+# define BTRFS_IOC_CLONE _IOW (BTRFS_IOCTL_MAGIC, 9, int)
+                if (flags & FILEUTILS_REFLINK) {
+                        retval = ioctl(dst_fd, BTRFS_IOC_CLONE, src_fd);
+                        if (retval == 0)
+                                goto do_close;
+                        /* reflink did not work */
+                        if (flags & FILEUTILS_REFLINK_ALWAYS) {
+                                bb_perror_msg("failed to clone '%s' from '%s'", dest, source);
+                                goto do_close;
+                        }
+                        /* fall through to standard copy */
+                        retval = 0;
+                }
+#endif
                 if (bb_copyfd_eof(src_fd, dst_fd) == -1)
                         retval = -1;
+ IF_FEATURE_CP_REFLINK(do_close:)
                 /* Careful with writing... */
                 if (close(dst_fd) < 0) {
                         bb_perror_msg("error writing to '%s'", dest);