Add move-blocks scoutfs cli command

Add a move-blocks command that translates arguments and calls the
MOVE_BLOCKS ioctl.

Signed-off-by: Zach Brown <zab@versity.com>

utils/src/move_blocks.c

@@ -0,0 +1,161 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <getopt.h>
+#include <assert.h>
+#include <argp.h>
+
+#include "sparse.h"
+#include "util.h"
+#include "format.h"
+#include "ioctl.h"
+#include "cmd.h"
+#include "parse.h"
+
+struct move_blocks_args {
+	char *from_path;
+	u64 from_offset;
+	u64 length;
+	char *to_path;
+	u64 to_offset;
+
+	unsigned from_off_set:1,
+	         len_set:1,
+	         to_off_set:1;
+};
+
+static int do_move_blocks(struct move_blocks_args *args)
+{
+	struct scoutfs_ioctl_move_blocks mb;
+	int from_fd = -1;
+	int to_fd = -1;
+	int ret;
+
+	from_fd = open(args->from_path, O_RDWR);
+	if (from_fd < 0) {
+		ret = -errno;
+		fprintf(stderr, "failed to open '%s': %s (%d)\n",
+			args->from_path, strerror(errno), errno);
+		goto out;
+	}
+
+	to_fd = open(args->to_path, O_RDWR);
+	if (to_fd < 0) {
+		ret = -errno;
+		fprintf(stderr, "failed to open '%s': %s (%d)\n",
+			args->to_path, strerror(errno), errno);
+		goto out;
+	}
+
+	mb.from_fd = from_fd;
+	mb.from_off = args->from_offset;
+	mb.len = args->length;
+	mb.to_off = args->to_offset;
+
+	ret = ioctl(to_fd, SCOUTFS_IOC_MOVE_BLOCKS, &mb);
+	if (ret < 0) {
+		ret = -errno;
+		fprintf(stderr, "ioctl failed on '%s': %s (%d)\n",
+			args->to_path, strerror(errno), errno);
+	}
+
+out:
+	if (from_fd >= 0)
+		close(from_fd);
+	if (to_fd >= 0)
+		close(to_fd);
+
+	return ret;
+}
+
+static int parse_move_blocks_opts(int key, char *arg, struct argp_state *state)
+{
+	struct move_blocks_args *args = state->input;
+	int ret;
+
+	switch (key) {
+	case 'f':
+		ret = parse_u64(arg, &args->from_offset);
+		if (ret)
+			return ret;
+		args->from_off_set = 1;
+		break;
+	case 'l':
+		ret = parse_human(arg, &args->length);
+		if (ret)
+			return ret;
+		args->len_set = 1;
+		break;
+	case 't':
+		ret = parse_human(arg, &args->to_offset);
+		if (ret)
+			return ret;
+		args->to_off_set = 1;
+		break;
+	case ARGP_KEY_ARG:
+		if (args->to_path)
+			argp_error(state, "more than two file path arguments given");
+		if (args->from_path)
+			args->to_path = strdup_or_error(state, arg);
+		else
+			args->from_path = strdup_or_error(state, arg);
+		break;
+	case ARGP_KEY_FINI:
+		if (!args->from_path)
+			argp_error(state, "must provide from file path");
+		if (!args->to_path)
+			argp_error(state, "must provide to file path");
+		if (!args->from_off_set)
+			argp_error(state, "must provide from file offset --from-offset");
+		if (!args->len_set)
+			argp_error(state, "must provide region length --length");
+		if (!args->to_off_set)
+			argp_error(state, "must provide to file offset --to-offset");
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static struct argp_option move_blocks_options[] = {
+	{ "from-offset", 'f', "OFFSET", 0,
+	   "Byte offset in from file of region to move [Required]"},
+	{ "length", 'l', "LENGTH", 0,
+	   "Length in bytes of region to move between files [Required]"},
+	{ "to-offset", 't', "OFFSET", 0,
+	   "Byte offset in to file where region will be moved to [Required]"},
+	{ NULL }
+};
+
+static struct argp move_blocks_argp = {
+	move_blocks_options,
+	parse_move_blocks_opts,
+	"FROM_FILE --from-offset OFFSET --length LENGTH TO_FILE --to-offset OFFSET",
+	"Move a fixed-size region of extents from one regular file to another",
+};
+
+static int move_blocks_cmd(int argc, char **argv)
+{
+	struct move_blocks_args args = {NULL};
+	int ret;
+
+	ret = argp_parse(&move_blocks_argp, argc, argv, 0, NULL, &args);
+	if (ret)
+		return ret;
+
+	return do_move_blocks(&args);
+}
+
+static void __attribute__((constructor)) move_blocks_ctor(void)
+{
+	cmd_register_argp("move-blocks", &move_blocks_argp, GROUP_AGENT,
+			  move_blocks_cmd);
+}