From 90495a45e4ed40bf411a75959346fbaafa465fc1 Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Fri, 26 Jan 2007 10:48:35 -0500 Subject: Filling out most of the ext2 superblock correctly now. --- toys/mke2fs.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-) diff --git a/toys/mke2fs.c b/toys/mke2fs.c index 464b8b50..0c71da87 100644 --- a/toys/mke2fs.c +++ b/toys/mke2fs.c @@ -85,17 +85,11 @@ int mke2fs_main(void) else error_exit("bad blocksize"); sb->log_block_size = sb->log_frag_size = SWAP_LE32(temp); - // Fill out blocks_count, inodes_count, r_blocks_count + // Fill out blocks_count and r_blocks_count if (!TT.blocks) TT.blocks = length/TT.blocksize; sb->blocks_count = SWAP_LE32(TT.blocks); - if (!TT.inodes) { - if (!TT.bytes_per_inode) TT.bytes_per_inode = 8192; - TT.inodes = (TT.blocks * (uint64_t)TT.blocksize) / TT.bytes_per_inode; - } - sb->inodes_count = SWAP_LE32(TT.inodes); - if (!TT.reserved_percent) TT.reserved_percent = 5; temp = (TT.blocks * (uint64_t)TT.reserved_percent) /100; sb->r_blocks_count = SWAP_LE32(temp); @@ -106,14 +100,34 @@ int mke2fs_main(void) temp = TT.blocksize*8; sb->blocks_per_group = sb->frags_per_group = SWAP_LE32(temp); - // Set inodes_per_group + // How many block groups do we need? (Round up avoiding integer overflow.) TT.groups = (TT.blocks)/temp; - if (TT.blocks & (temp-1)) TT.groups++; // Round up without int overflow. - temp = TT.inodes/TT.groups; - if (TT.blocks & (TT.groups-1)) TT.blocks++; - sb->inodes_per_group = SWAP_LE32(temp); + if (TT.blocks & (temp-1)) TT.groups++; + + // Figure out how many inodes we need. + + if (!TT.inodes) { + if (!TT.bytes_per_inode) TT.bytes_per_inode = 8192; + TT.inodes = (TT.blocks * (uint64_t)TT.blocksize) / TT.bytes_per_inode; + } + + // Figure out inodes per group, rounded up to block size. + + // How many blocks of inodes total, rounded up + temp = TT.inodes / (TT.blocksize/sizeof(struct ext2_inode)); + if (TT.inodes & (TT.blocksize-1)) temp++; + // How many blocks of inodes per group, again rounded up + TT.inodes = temp / TT.groups; + if (temp & (TT.groups-1)) TT.inodes++; + // How many inodes per group is that? + TT.inodes *= (TT.blocksize/sizeof(struct ext2_inode)); + + // Set inodes_per_group and total inodes_count + sb->inodes_per_group = SWAP_LE32(TT.inodes); + sb->inodes_count = SWAP_LE32(TT.inodes *= TT.groups); + // Fill out the rest of the superblock. sb->max_mnt_count=0xFFFF; sb->wtime = sb->lastcheck = sb->mkfs_time = SWAP_LE32(time(NULL)); sb->magic = SWAP_LE32(0xEF53); -- cgit v1.2.3