ext4_utils: mark uninitialized inode tables in block groups

Block groups that have no used inodes have their inode table left
uninitialized, unless -t is specified, in which case they are
explicitly zeroed.  When they are uninitialized, writing a sparse
ext4 image over existing data can cause e2fsck to confuse the
uninitialized data for lost inodes.

Set the EXT4_BG_INODE_UNINIT flags on block groups that have no
used inodes.  This flag requires the block group checksum feature
to be enabled, so also enable the checksum feature in the superblock
and compute the checksum for the block group.

Since zeroing the inode tables is now useless, remove the code for
it and deprecate the -t command line option.

Change-Id: I4927c1d866d051547cf0dadc8c8703ded0163925

1 files changed, 3 insertions, 4 deletions

diff --git a/ext4_utils/make_ext4fs_main.c b/ext4_utils/make_ext4fs_main.c
index 739c4a16..b6c740d2 100644
--- a/ext4_utils/make_ext4fs_main.c
+++ b/ext4_utils/make_ext4fs_main.c
@@ -53,7 +53,7 @@ static void usage(char *path)
 	fprintf(stderr, "    [ -g <blocks per group> ] [ -i <inodes> ] [ -I <inode size> ]\n");
 	fprintf(stderr, "    [ -L <label> ] [ -f ] [ -a <android mountpoint> ]\n");
 	fprintf(stderr, "    [ -S file_contexts ]\n");
-	fprintf(stderr, "    [ -z | -s ] [ -t ] [ -w ] [ -c ] [ -J ] [ -v ]\n");
+	fprintf(stderr, "    [ -z | -s ] [ -w ] [ -c ] [ -J ] [ -v ]\n");
 	fprintf(stderr, "    <filename> [<directory>]\n");
 }
 
@@ -68,7 +68,6 @@ int main(int argc, char **argv)
 	int sparse = 0;
 	int crc = 0;
 	int wipe = 0;
-	int init_itabs = 0;
 	int fd;
 	int exitcode;
 	int verbose = 0;
@@ -129,7 +128,7 @@ int main(int argc, char **argv)
 			sparse = 1;
 			break;
 		case 't':
-			init_itabs = 1;
+			fprintf(stderr, "Warning: -t (initialize inode tables) is deprecated\n");
 			break;
 		case 'S':
 #ifndef USE_MINGW
@@ -202,7 +201,7 @@ int main(int argc, char **argv)
 	}
 
 	exitcode = make_ext4fs_internal(fd, directory, mountpoint, fs_config_func, gzip,
-			sparse, crc, wipe, init_itabs, sehnd, verbose);
+			sparse, crc, wipe, sehnd, verbose);
 	close(fd);
 
 	return exitcode;