resizepart: add new command

This is a simple wrapper for BLKPG_RESIZE_PARTITION (since kernel 3.6).

Co-Author: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 109 insertions, 0 deletions

diff --git a/disk-utils/resizepart.c b/disk-utils/resizepart.c
new file mode 100644
index 000000000..ad8a7b606
--- /dev/null
+++ b/disk-utils/resizepart.c
@@ -0,0 +1,109 @@
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "c.h"
+#include "nls.h"
+#include "partx.h"
+#include "sysfs.h"
+#include "strutils.h"
+
+static void __attribute__ ((__noreturn__)) usage(FILE * out)
+{
+	fputs(USAGE_HEADER, out);
+	fprintf(out, _(" %s <disk device> <partition number> <length>\n"),
+		program_invocation_short_name);
+	fputs(USAGE_OPTIONS, out);
+	fputs(USAGE_HELP, out);
+	fputs(USAGE_VERSION, out);
+	fprintf(out, USAGE_MAN_TAIL("resizepart(8)"));
+	exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+static int get_partition_start(int fd, int partno, uint64_t *start)
+{
+	struct stat st;
+	struct sysfs_cxt disk = UL_SYSFSCXT_EMPTY,
+			 part = UL_SYSFSCXT_EMPTY;
+	dev_t devno = 0;
+	int rc = -1;
+
+	/*
+	 * wholedisk
+	 */
+	if (fstat(fd, &st) || !S_ISBLK(st.st_mode))
+		goto done;
+	devno = st.st_rdev;
+	if (sysfs_init(&disk, devno, NULL))
+		goto done;
+	/*
+	 * partition
+	 */
+	devno = sysfs_partno_to_devno(&disk, partno);
+	if (!devno)
+		goto done;
+	if (sysfs_init(&part, devno, &disk))
+		goto done;
+	if (sysfs_read_u64(&part, "start", start))
+		goto done;
+
+	rc = 0;
+done:
+	sysfs_deinit(&part);
+	sysfs_deinit(&disk);
+	return rc;
+}
+
+int main(int argc, char **argv)
+{
+	int c, fd, partno;
+	const char *wholedisk;
+	uint64_t start;
+
+	static const struct option longopts[] = {
+		{"help", no_argument, 0, 'h'},
+		{"version", no_argument, 0, 'V'},
+		{NULL, no_argument, 0, '0'},
+	};
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+
+	while ((c = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
+		switch (c) {
+		case 'V':
+			printf(UTIL_LINUX_VERSION);
+			return EXIT_SUCCESS;
+		case 'h':
+			usage(stdout);
+		default:
+			usage(stderr);
+		}
+
+	if (argc != 4)
+		usage(stderr);
+
+	wholedisk = argv[1];
+	partno = strtou32_or_err(argv[2], _("invalid partition number argument"));
+
+	if ((fd = open(wholedisk, O_RDONLY)) < 0)
+		err(EXIT_FAILURE, _("cannot open %s"), wholedisk);
+
+	if (get_partition_start(fd, partno, &start))
+		err(EXIT_FAILURE, _("%s: failed to get start of the partition number %s"),
+				wholedisk, argv[2]);
+
+	fprintf(stderr, "KZAK: %d, start=%jd\n", partno, start);
+	exit(1);
+
+	if (partx_resize_partition(fd, partno, start,
+			strtou64_or_err(argv[3], _("invalid length argument"))))
+		err(EXIT_FAILURE, _("failed to resize partition"));
+
+	return 0;
+}