Allow specifying reserved blocks percentage

Signed-off-by: Jo-Philipp Wich <[email protected]>

Author: jow-

ext4_sb.h

@@ -39,6 +39,7 @@ struct fs_info {
 	uint16_t feat_compat;
 	uint16_t feat_incompat;
 	uint32_t bg_desc_reserve_blocks;
+	uint32_t reserve_pcnt;
 	const char *label;
 	uint8_t no_journal;
 };

ext4_utils.c

@@ -191,7 +191,7 @@ void ext4_fill_in_sb()
 
 	sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
 	sb->s_blocks_count_lo = aux_info.len_blocks;
-	sb->s_r_blocks_count_lo = 0;
+	sb->s_r_blocks_count_lo = (aux_info.len_blocks / 100) * info.reserve_pcnt;
 	sb->s_free_blocks_count_lo = 0;
 	sb->s_free_inodes_count = 0;
 	sb->s_first_data_block = aux_info.first_data_block;
@@ -533,4 +533,3 @@ int read_ext(int fd, int verbose)
 
 	return 0;
 }
-

make_ext4fs.c

@@ -456,6 +456,7 @@ int make_ext4fs_internal(int fd, const char *_directory,
 
 	printf("    Blocks: %"PRIu64"\n", aux_info.len_blocks);
 	printf("    Block groups: %d\n", aux_info.groups);
+	printf("    Reserved blocks: %"PRIu64"\n",  (aux_info.len_blocks / 100) * info.reserve_pcnt);
 	printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
 
 	ext4_sparse_file = sparse_file_new(info.block_size, info.len);

make_ext4fs_main.c

@@ -35,7 +35,7 @@ static void usage(char *path)
 {
 	fprintf(stderr, "%s [ -l <len> ] [ -j <journal size> ] [ -b <block_size> ]\n", basename(path));
 	fprintf(stderr, "    [ -g <blocks per group> ] [ -i <inodes> ] [ -I <inode size> ]\n");
-	fprintf(stderr, "    [ -L <label> ] [ -f ]\n");
+	fprintf(stderr, "    [ -m <reserved blocks percent> ] [ -L <label> ] [ -f ]\n");
 	fprintf(stderr, "    [ -S file_contexts ] [ -C fs_config ] [ -T timestamp ]\n");
 	fprintf(stderr, "    [ -z | -s ] [ -w ] [ -c ] [ -J ] [ -v ] [ -B <block_list_file> ]\n");
 	fprintf(stderr, "    <filename> [<directory>]\n");
@@ -58,7 +58,7 @@ int main(int argc, char **argv)
 	time_t fixed_time = -1;
 	FILE* block_list_file = NULL;
 
-	while ((opt = getopt(argc, argv, "l:j:b:g:i:I:L:T:C:B:fwzJsctv")) != -1) {
+	while ((opt = getopt(argc, argv, "l:j:b:g:i:I:L:T:C:B:m:fwzJsctv")) != -1) {
 		switch (opt) {
 		case 'l':
 			info.len = parse_num(optarg);
@@ -118,6 +118,9 @@ int main(int argc, char **argv)
 				exit(EXIT_FAILURE);
 			}
 			break;
+		case 'm':
+			info.reserve_pcnt = strtoul(optarg, NULL, 0);
+			break;
 		default: /* '?' */
 			usage(argv[0]);
 			exit(EXIT_FAILURE);