Merge pull request #62 from michaelolbrich/hd-fill

image-hd: add option to extend the image to the full size

5 files changed, 57 insertions, 1 deletions

diff --git a/genimage.h b/genimage.h
index 1ebe1cd..eabcc46 100644
--- a/genimage.h
+++ b/genimage.h
@@ -143,6 +143,7 @@ int pad_file(struct image *image, const char *infile,
 		size_t size, unsigned char fillpattern, enum pad_mode mode);
 int insert_data(struct image *image, const char *data, const char *outfile,
 		size_t size, long offset);
+int extend_file(struct image *image, size_t size);
 int reload_partitions(struct image *image);
 
 unsigned long long cfg_getint_suffix(cfg_t *sec, const char *name);
diff --git a/image-hd.c b/image-hd.c
index 90f550e..204d601 100644
--- a/image-hd.c
+++ b/image-hd.c
@@ -33,6 +33,7 @@ struct hdimage {
 	uint32_t disksig;
 	const char *disk_uuid;
 	cfg_bool_t gpt;
+	cfg_bool_t fill;
 };
 
 struct mbr_partition_entry {
@@ -379,6 +380,14 @@ static int hdimage_generate(struct image *image)
 		}
 	}
 
+	if (hd->fill) {
+		ret = extend_file(image, image->size);
+		if (ret) {
+			image_error(image, "failed to fill the image.\n");
+			return ret;
+		}
+	}
+
 	if (hd->partition_table) {
 		if (hd->gpt) {
 			ret = hdimage_insert_gpt(image, &image->partitions);
@@ -414,6 +423,7 @@ static int hdimage_setup(struct image *image, cfg_t *cfg)
 	hd->extended_partition = cfg_getint(cfg, "extended-partition");
 	hd->disksig = strtoul(cfg_getstr(cfg, "disk-signature"), NULL, 0);
 	hd->gpt = cfg_getbool(cfg, "gpt");
+	hd->fill = cfg_getbool(cfg, "fill");
 	hd->disk_uuid = cfg_getstr(cfg, "disk-uuid");
 
 	if (hd->extended_partition > 4) {
@@ -585,6 +595,7 @@ cfg_opt_t hdimage_opts[] = {
 	CFG_BOOL("partition-table", cfg_true, CFGF_NONE),
 	CFG_INT("extended-partition", 0, CFGF_NONE),
 	CFG_BOOL("gpt", cfg_false, CFGF_NONE),
+	CFG_BOOL("fill", cfg_false, CFGF_NONE),
 	CFG_END()
 };
 
diff --git a/test/basic-images.test b/test/basic-images.test
index cf6d68b..4554b7a 100755
--- a/test/basic-images.test
+++ b/test/basic-images.test
@@ -198,7 +198,7 @@ exec_test_set_prereq sfdisk
 test_expect_success fdisk,sfdisk "hdimage" "
 	setup_test_images &&
 	run_genimage hdimage.config test.hdimage &&
-	check_size images/test.hdimage 9442816 &&
+	check_size images/test.hdimage 10485760 &&
 	# check the this identifier
 	fdisk -l images/test.hdimage | grep identifier: > hdimage.fdisk &&
 	# check partitions; filter output to handle different sfdisk versions
diff --git a/test/hdimage.config b/test/hdimage.config
index 117e69f..09978c4 100644
--- a/test/hdimage.config
+++ b/test/hdimage.config
@@ -1,6 +1,7 @@
 image test.hdimage {
 	hdimage {
 		align = 1M
+		fill = true
 		disk-signature = 0x12345678
 	}
 	partition part1 {
diff --git a/util.c b/util.c
index bccd3dd..f659548 100644
--- a/util.c
+++ b/util.c
@@ -479,6 +479,49 @@ err_out:
 	return ret;
 }
 
+int extend_file(struct image *image, size_t size)
+{
+	const char *outfile = imageoutfile(image);
+	char buf = '\0';
+	int f;
+	off_t offset;
+	int ret = 0;
+
+	f = open_file(image, outfile, 0);
+	if (f < 0)
+		return f;
+
+	offset = lseek(f, 0, SEEK_END);
+	if (offset < 0) {
+		ret = -errno;
+		image_error(image, "seek: %s\n", strerror(errno));
+		goto out;
+	}
+	if ((size_t)offset > size) {
+		ret = -EINVAL;
+		image_error(image, "output file is larger than requested size\n");
+		goto out;
+	}
+	if ((size_t)offset == size)
+		goto out;
+
+	if (lseek(f, size - 1, SEEK_SET) < 0) {
+		ret = -errno;
+		image_error(image, "seek %s: %s\n", outfile, strerror(errno));
+		goto out;
+	}
+	ret = write(f, &buf, 1);
+	if (ret < 1) {
+		ret = -errno;
+		image_error(image, "write %s: %s\n", outfile, strerror(errno));
+		goto out;
+	}
+	ret = 0;
+out:
+	close(f);
+	return ret;
+}
+
 int uuid_validate(const char *str)
 {
 	int i;