The cloner program is capable of cloning files using the BTRFS_IOC_CLONE
and BTRFS_IOC_CLONE_RANGE ioctls.
Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
---
src/Makefile | 2 +-
src/cloner.c | 168 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 169 insertions(+), 1 deletion(-)
create mode 100644 src/cloner.c
diff --git a/src/Makefile b/src/Makefile
index 84c8297..6509f2d 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -18,7 +18,7 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
locktest unwritten_mmap bulkstat_unlink_test t_stripealign \
bulkstat_unlink_test_modified t_dir_offset t_futimens t_immutable \
stale_handle pwrite_mmap_blocked t_dir_offset2 seek_sanity_test \
- seek_copy_test t_readdir_1 t_readdir_2 fsync-tester nsexec
+ seek_copy_test t_readdir_1 t_readdir_2 fsync-tester nsexec cloner
SUBDIRS =
diff --git a/src/cloner.c b/src/cloner.c
new file mode 100644
index 0000000..59defbb
--- /dev/null
+++ b/src/cloner.c
@@ -0,0 +1,168 @@
+/*
+ * Tiny program to perform file (range) clones using raw Btrfs ioctls.
+ * It should only be needed until btrfs-progs has an xfs_io equivalent.
+ *
+ * Copyright (C) 2014 SUSE Linux Products GmbH. All Rights Reserved.
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+struct btrfs_ioctl_clone_range_args {
+ int64_t src_fd;
+ uint64_t src_offset;
+ uint64_t src_length;
+ uint64_t dest_offset;
+};
+
+#define BTRFS_IOCTL_MAGIC 0x94
+#define BTRFS_IOC_CLONE _IOW(BTRFS_IOCTL_MAGIC, 9, int)
+#define BTRFS_IOC_CLONE_RANGE _IOW(BTRFS_IOCTL_MAGIC, 13, \
+ struct btrfs_ioctl_clone_range_args)
+
+static void
+usage(char *name, const char *msg)
+{
+ printf("Fatal: %s\n"
+ "Usage:\n"
+ "%s [options] <src_file> <dest_file>\n"
+ "\tA full file clone (reflink) is performed by default, "
+ "unless any of the following are specified:\n"
+ "\t-s <offset>: source file offset (default = 0)\n"
+ "\t-d <offset>: destination file offset (default = 0)\n"
+ "\t-l <length>: length of clone (default = 0)\n",
+ msg, name);
+ _exit(1);
+}
+
+static int
+clone_file(int src_fd, int dst_fd)
+{
+ int ret = ioctl(dst_fd, BTRFS_IOC_CLONE, src_fd);
+ if (ret != 0)
+ ret = errno;
+ return ret;
+}
+
+static int
+clone_file_range(int src_fd, int dst_fd, uint64_t src_off, uint64_t dst_off,
+ uint64_t len)
+{
+ struct btrfs_ioctl_clone_range_args cr_args;
+ int ret;
+
+ memset(&cr_args, 0, sizeof(cr_args));
+ cr_args.src_fd = src_fd;
+ cr_args.src_offset = src_off;
+ cr_args.src_length = len;
+ cr_args.dest_offset = dst_off;
+ ret = ioctl(dst_fd, BTRFS_IOC_CLONE_RANGE, &cr_args);
+ if (ret != 0)
+ ret = errno;
+ return ret;
+}
+
+int
+main(int argc, char **argv)
+{
+ bool full_file = true;
+ uint64_t src_off = 0;
+ uint64_t dst_off = 0;
+ uint64_t len = 0;
+ char *src_file;
+ int src_fd;
+ char *dst_file;
+ int dst_fd;
+ int ret;
+ int opt;
+
+ while ((opt = getopt(argc, argv, "s:d:l:")) != -1) {
+ switch (opt) {
+ case 's':
+ src_off = atoi(optarg);
+ full_file = false;
+ break;
+ case 'd':
+ dst_off = atoi(optarg);
+ full_file = false;
+ break;
+ case 'l':
+ len = atoi(optarg);
+ full_file = false;
+ break;
+ default:
+ usage(argv[0], "invalid argument");
+ }
+ }
+
+ /* should be exactly two args left */
+ if (optind != argc - 2)
+ usage(argv[0], "src_file and dst_file arguments are madatory");
+
+ src_file = (char *)strdup(argv[optind++]);
+ if (src_file == NULL) {
+ ret = ENOMEM;
+ goto err_out;
+ }
+ dst_file = (char *)strdup(argv[optind++]);
+ if (dst_file == NULL) {
+ ret = ENOMEM;
+ goto err_src_free;
+ }
+
+ src_fd = open(src_file, O_RDONLY);
+ if (src_fd == -1) {
+ ret = errno;
+ goto err_dst_free;
+ }
+ dst_fd = open(dst_file, O_CREAT | O_WRONLY, 0644);
+ if (dst_fd == -1) {
+ ret = errno;
+ goto err_src_close;
+ }
+
+ if (full_file) {
+ ret = clone_file(src_fd, dst_fd);
+ } else {
+ ret = clone_file_range(src_fd, dst_fd, src_off, dst_off, len);
+ }
+ if (ret != 0) {
+ printf("clone failed with %d\n", ret);
+ goto err_dst_close;
+ }
+
+ ret = 0;
+err_dst_close:
+ ret |= close(dst_fd);
+err_src_close:
+ ret |= close(src_fd);
+err_dst_free:
+ free(dst_file);
+err_src_free:
+ free(src_file);
+err_out:
+ return ret;
+}
--
1.8.4.5
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