diff options
Diffstat (limited to 'toys/mke2fs.c')
| -rw-r--r-- | toys/mke2fs.c | 73 |
1 files changed, 56 insertions, 17 deletions
diff --git a/toys/mke2fs.c b/toys/mke2fs.c index 8266cec4..464b8b50 100644 --- a/toys/mke2fs.c +++ b/toys/mke2fs.c @@ -7,6 +7,8 @@ #include "toys.h" +#define TT toy.mke2fs + // b - block size (1024, 2048, 4096) // F - force (run on mounted device or non-block device) // i - bytes per inode @@ -54,39 +56,76 @@ void create_uuid(char *uuid) int mke2fs_main(void) { - struct ext2_super_block *sb = xzalloc(sizeof(struct ext2_super_block)); - int temp; + struct ext2_superblock *sb = xzalloc(sizeof(struct ext2_superblock)); + uint32_t temp; off_t length; // Handle command line arguments. if (toys.optargs[1]) { - sscanf(toys.optargs[1], "%u", &(sb->inodes_count)); + sscanf(toys.optargs[1], "%u", &TT.blocks); temp = O_RDWR|O_CREAT; } else temp = O_RDWR; - // Check if filesystem is mounted + // TODO: Check if filesystem is mounted here // For mke?fs, open file. For gene?fs, create file. - length = fdlength(toy.mke2fs.fsfd = xcreate(*toys.optargs, temp, 0777)); + length = fdlength(TT.fsfd = xcreate(*toys.optargs, temp, 0777)); + + // TODO: collect gene2fs list, calculate requirements. - if (toy.mke2fs.blocksize && toy.mke2fs.blocksize!=1024 - && toy.mke2fs.blocksize!=2048 && toy.mke2fs.blocksize!=4096) - error_exit("bad blocksize"); + // Fill out superblock structure - // Determine block size. If unspecified, use simple heuristic. - if (toy.mke2fs.blocksize) - sb->log_block_size = (length && length < 1<<24) ? 1024 : 4096; - else sb->log_block_size = toy.mke2fs.blocksize; + // Determine appropriate block size, set log_block_size and log_frag_size. - if (!sb->inodes_count) sb->inodes_count = length/toy.mke2fs.blocksize; + if (!TT.blocksize) TT.blocksize = (length && length < 1<<29) ? 1024 : 4096; + if (TT.blocksize == 1024) temp = 0; + else if (TT.blocksize == 2048) temp = 1; + else if (TT.blocksize == 4096) temp = 2; + else error_exit("bad blocksize"); + sb->log_block_size = sb->log_frag_size = SWAP_LE32(temp); - // Fill out superblock structure + // Fill out blocks_count, inodes_count, 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); + + // Set blocks_per_group and frags_per_group, which is the size of an + // allocation bitmap that fits in one block (I.E. how many bits per block)? + + temp = TT.blocksize*8; + sb->blocks_per_group = sb->frags_per_group = SWAP_LE32(temp); + + // Set inodes_per_group + + 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); + + sb->max_mnt_count=0xFFFF; + sb->wtime = sb->lastcheck = sb->mkfs_time = SWAP_LE32(time(NULL)); + sb->magic = SWAP_LE32(0xEF53); + sb->state = sb->errors = SWAP_LE16(1); sb->rev_level = SWAP_LE32(1); + sb->inode_size = sizeof(struct ext2_inode); sb->feature_incompat = SWAP_LE32(EXT2_FEATURE_INCOMPAT_FILETYPE); sb->feature_ro_compat = SWAP_LE32(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER); + create_uuid(sb->uuid); + // If we're called as mke3fs or mkfs.ext3, do a journal. //if (strchr(toys.which->name,'3')) @@ -94,11 +133,11 @@ int mke2fs_main(void) // We skip the first 1k (to avoid the boot sector, if any). Use this to // figure out if this file is seekable. - if(-1 == lseek(toy.mke2fs.fsfd, 1024, SEEK_SET)) perror_exit("lseek"); - //{ toy.mke2fs.noseek=1; xwrite(toy.mke2fs.fsfd, sb, 1024); } + if(-1 == lseek(TT.fsfd, 1024, SEEK_SET)) perror_exit("lseek"); + //{ TT.noseek=1; xwrite(TT.fsfd, sb, 1024); } // Write superblock to disk. - xwrite(toy.mke2fs.fsfd, sb, 3072); // 4096-1024 + xwrite(TT.fsfd, sb, sizeof(struct ext2_superblock)); // 4096-1024 return 0; } |