| /* mke2fs.c - Create an ext2 filesystem image. |
| * |
| * Copyright 2006, 2007 Rob Landley <rob@landley.net> |
| |
| // Still to go: "E:jJ:L:m:O:" |
| USE_MKE2FS(NEWTOY(mke2fs, "<1>2g:Fnqm#N#i#b#", TOYFLAG_SBIN)) |
| |
| config MKE2FS |
| bool "mke2fs" |
| default n |
| help |
| usage: mke2fs [-Fnq] [-b ###] [-N|i ###] [-m ###] device |
| |
| Create an ext2 filesystem on a block device or filesystem image. |
| |
| -F Force to run on a mounted device |
| -n Don't write to device |
| -q Quiet (no output) |
| -b size Block size (1024, 2048, or 4096) |
| -N inodes Allocate this many inodes |
| -i bytes Allocate one inode for every XXX bytes of device |
| -m percent Reserve this percent of filesystem space for root user |
| |
| config MKE2FS_JOURNAL |
| bool "Journaling support (ext3)" |
| default n |
| depends on MKE2FS |
| help |
| usage: mke2fs [-j] [-J size=###,device=XXX] |
| |
| -j Create journal (ext3) |
| -J Journal options |
| size: Number of blocks (1024-102400) |
| device: Specify an external journal |
| |
| config MKE2FS_GEN |
| bool "Generate (gene2fs)" |
| default n |
| depends on MKE2FS |
| help |
| usage: gene2fs [options] device filename |
| |
| The [options] are the same as mke2fs. |
| |
| config MKE2FS_LABEL |
| bool "Label support" |
| default n |
| depends on MKE2FS |
| help |
| usage: mke2fs [-L label] [-M path] [-o string] |
| |
| -L Volume label |
| -M Path to mount point |
| -o Created by |
| |
| config MKE2FS_EXTENDED |
| bool "Extended options" |
| default n |
| depends on MKE2FS |
| help |
| usage: mke2fs [-E stride=###] [-O option[,option]] |
| |
| -E stride= Set RAID stripe size (in blocks) |
| -O [opts] Specify fewer ext2 option flags (for old kernels) |
| All of these are on by default (as appropriate) |
| none Clear default options (all but journaling) |
| dir_index Use htree indexes for large directories |
| filetype Store file type info in directory entry |
| has_journal Set by -j |
| journal_dev Set by -J device=XXX |
| sparse_super Don't allocate huge numbers of redundant superblocks |
| */ |
| |
| #define FOR_mke2fs |
| #include "toys.h" |
| |
| GLOBALS( |
| // Command line arguments. |
| long blocksize; |
| long bytes_per_inode; |
| long inodes; // Total inodes in filesystem. |
| long reserved_percent; // Integer precent of space to reserve for root. |
| char *gendir; // Where to read dirtree from. |
| |
| // Internal data. |
| struct dirtree *dt; // Tree of files to copy into the new filesystem. |
| unsigned treeblocks; // Blocks used by dt |
| unsigned treeinodes; // Inodes used by dt |
| |
| unsigned blocks; // Total blocks in the filesystem. |
| unsigned freeblocks; // Free blocks in the filesystem. |
| unsigned inodespg; // Inodes per group |
| unsigned groups; // Total number of block groups. |
| unsigned blockbits; // Bits per block. (Also blocks per group.) |
| |
| // For gene2fs |
| unsigned nextblock; // Next data block to allocate |
| unsigned nextgroup; // Next group we'll be allocating from |
| int fsfd; // File descriptor of filesystem (to output to). |
| ) |
| |
| // Stuff defined in linux/ext2_fs.h |
| |
| #define EXT2_SUPER_MAGIC 0xEF53 |
| |
| struct ext2_superblock { |
| uint32_t inodes_count; // Inodes count |
| uint32_t blocks_count; // Blocks count |
| uint32_t r_blocks_count; // Reserved blocks count |
| uint32_t free_blocks_count; // Free blocks count |
| uint32_t free_inodes_count; // Free inodes count |
| uint32_t first_data_block; // First Data Block |
| uint32_t log_block_size; // Block size |
| uint32_t log_frag_size; // Fragment size |
| uint32_t blocks_per_group; // Blocks per group |
| uint32_t frags_per_group; // Fragments per group |
| uint32_t inodes_per_group; // Inodes per group |
| uint32_t mtime; // Mount time |
| uint32_t wtime; // Write time |
| uint16_t mnt_count; // Mount count |
| uint16_t max_mnt_count; // Maximal mount count |
| uint16_t magic; // Magic signature |
| uint16_t state; // File system state |
| uint16_t errors; // Behaviour when detecting errors |
| uint16_t minor_rev_level; // minor revision level |
| uint32_t lastcheck; // time of last check |
| uint32_t checkinterval; // max. time between checks |
| uint32_t creator_os; // OS |
| uint32_t rev_level; // Revision level |
| uint16_t def_resuid; // Default uid for reserved blocks |
| uint16_t def_resgid; // Default gid for reserved blocks |
| uint32_t first_ino; // First non-reserved inode |
| uint16_t inode_size; // size of inode structure |
| uint16_t block_group_nr; // block group # of this superblock |
| uint32_t feature_compat; // compatible feature set |
| uint32_t feature_incompat; // incompatible feature set |
| uint32_t feature_ro_compat; // readonly-compatible feature set |
| char uuid[16]; // 128-bit uuid for volume |
| char volume_name[16]; // volume name |
| char last_mounted[64]; // directory where last mounted |
| uint32_t alg_usage_bitmap; // For compression |
| // For EXT2_COMPAT_PREALLOC |
| uint8_t prealloc_blocks; // Nr of blocks to try to preallocate |
| uint8_t prealloc_dir_blocks; //Nr to preallocate for dirs |
| uint16_t padding1; |
| // For EXT3_FEATURE_COMPAT_HAS_JOURNAL |
| uint8_t journal_uuid[16]; // uuid of journal superblock |
| uint32_t journal_inum; // inode number of journal file |
| uint32_t journal_dev; // device number of journal file |
| uint32_t last_orphan; // start of list of inodes to delete |
| uint32_t hash_seed[4]; // HTREE hash seed |
| uint8_t def_hash_version; // Default hash version to use |
| uint8_t padding2[3]; |
| uint32_t default_mount_opts; |
| uint32_t first_meta_bg; // First metablock block group |
| uint32_t mkfs_time; // Creation timestamp |
| uint32_t jnl_blocks[17]; // Backup of journal inode |
| // uint32_t reserved[172]; // Padding to the end of the block |
| }; |
| |
| struct ext2_group |
| { |
| uint32_t block_bitmap; // Block number of block bitmap |
| uint32_t inode_bitmap; // Block number of inode bitmap |
| uint32_t inode_table; // Block number of inode table |
| uint16_t free_blocks_count; // How many free blocks in this group? |
| uint16_t free_inodes_count; // How many free inodes in this group? |
| uint16_t used_dirs_count; // How many directories? |
| uint16_t reserved[7]; // pad to 32 bytes |
| }; |
| |
| struct ext2_dentry { |
| uint32_t inode; // Inode number |
| uint16_t rec_len; // Directory entry length |
| uint8_t name_len; // Name length |
| uint8_t file_type; |
| char name[0]; // File name |
| }; |
| |
| struct ext2_inode { |
| uint16_t mode; // File mode |
| uint16_t uid; // Low 16 bits of Owner Uid |
| uint32_t size; // Size in bytes |
| uint32_t atime; // Access time |
| uint32_t ctime; // Creation time |
| uint32_t mtime; // Modification time |
| uint32_t dtime; // Deletion Time |
| uint16_t gid; // Low 16 bits of Group Id |
| uint16_t links_count; // Links count |
| uint32_t blocks; // Blocks count |
| uint32_t flags; // File flags |
| uint32_t reserved1; |
| uint32_t block[15]; // Pointers to blocks |
| uint32_t generation; // File version (for NFS) |
| uint32_t file_acl; // File ACL |
| uint32_t dir_acl; // Directory ACL (or top bits of file length) |
| uint32_t faddr; // Last block in file |
| uint8_t frag; // Fragment number |
| uint8_t fsize; // Fragment size |
| uint16_t pad1; |
| uint16_t uid_high; // High bits of uid |
| uint16_t gid_high; // High bits of gid |
| uint32_t reserved2; |
| }; |
| |
| #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001 |
| #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002 |
| #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004 |
| #define EXT2_FEATURE_COMPAT_EXT_ATTR 0x0008 |
| #define EXT2_FEATURE_COMPAT_RESIZE_INO 0x0010 |
| #define EXT2_FEATURE_COMPAT_DIR_INDEX 0x0020 |
| |
| #define EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001 |
| #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE 0x0002 |
| #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR 0x0004 |
| |
| #define EXT2_FEATURE_INCOMPAT_COMPRESSION 0x0001 |
| #define EXT2_FEATURE_INCOMPAT_FILETYPE 0x0002 |
| #define EXT3_FEATURE_INCOMPAT_RECOVER 0x0004 |
| #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 |
| #define EXT2_FEATURE_INCOMPAT_META_BG 0x0010 |
| |
| #define EXT2_NAME_LEN 255 |
| |
| // Ext2 directory file types. Only the low 3 bits are used. The |
| // other bits are reserved for now. |
| |
| enum { |
| EXT2_FT_UNKNOWN, |
| EXT2_FT_REG_FILE, |
| EXT2_FT_DIR, |
| EXT2_FT_CHRDEV, |
| EXT2_FT_BLKDEV, |
| EXT2_FT_FIFO, |
| EXT2_FT_SOCK, |
| EXT2_FT_SYMLINK, |
| EXT2_FT_MAX |
| }; |
| |
| #define INODES_RESERVED 10 |
| |
| static uint32_t div_round_up(uint32_t a, uint32_t b) |
| { |
| uint32_t c = a/b; |
| |
| if (a%b) c++; |
| return c; |
| } |
| |
| // Calculate data blocks plus index blocks needed to hold a file. |
| |
| static uint32_t file_blocks_used(uint64_t size, uint32_t *blocklist) |
| { |
| uint32_t dblocks = (uint32_t)((size+(TT.blocksize-1))/TT.blocksize); |
| uint32_t idx=TT.blocksize/4, iblocks=0, diblocks=0, tiblocks=0; |
| |
| // Fill out index blocks in inode. |
| |
| if (blocklist) { |
| int i; |
| |
| // Direct index blocks |
| for (i=0; i<13 && i<dblocks; i++) blocklist[i] = i; |
| // Singly indirect index blocks |
| if (dblocks > 13+idx) blocklist[13] = 13+idx; |
| // Doubly indirect index blocks |
| idx = 13 + idx + (idx*idx); |
| if (dblocks > idx) blocklist[14] = idx; |
| |
| return 0; |
| } |
| |
| // Account for direct, singly, doubly, and triply indirect index blocks |
| |
| if (dblocks > 12) { |
| iblocks = ((dblocks-13)/idx)+1; |
| if (iblocks > 1) { |
| diblocks = ((iblocks-2)/idx)+1; |
| if (diblocks > 1) |
| tiblocks = ((diblocks-2)/idx)+1; |
| } |
| } |
| |
| return dblocks + iblocks + diblocks + tiblocks; |
| } |
| |
| // Use the parent pointer to iterate through the tree non-recursively. |
| static struct dirtree *treenext(struct dirtree *this) |
| { |
| while (this && !this->next) this = this->parent; |
| if (this) this = this->next; |
| |
| return this; |
| } |
| |
| // Recursively calculate the number of blocks used by each inode in the tree. |
| // Returns blocks used by this directory, assigns bytes used to *size. |
| // Writes total block count to TT.treeblocks and inode count to TT.treeinodes. |
| |
| static long check_treesize(struct dirtree *that, off_t *size) |
| { |
| long blocks; |
| |
| while (that) { |
| *size += sizeof(struct ext2_dentry) + strlen(that->name); |
| |
| if (that->child) |
| that->st.st_blocks = check_treesize(that->child, &that->st.st_size); |
| else if (S_ISREG(that->st.st_mode)) { |
| that->st.st_blocks = file_blocks_used(that->st.st_size, 0); |
| TT.treeblocks += that->st.st_blocks; |
| } |
| that = that->next; |
| } |
| TT.treeblocks += blocks = file_blocks_used(*size, 0); |
| TT.treeinodes++; |
| |
| return blocks; |
| } |
| |
| // Calculate inode numbers and link counts. |
| // |
| // To do this right I need to copy the tree and sort it, but here's a really |
| // ugly n^2 way of dealing with the problem that doesn't scale well to large |
| // numbers of files (> 100,000) but can be done in very little code. |
| // This rewrites inode numbers to their final values, allocating depth first. |
| |
| static void check_treelinks(struct dirtree *tree) |
| { |
| struct dirtree *current=tree, *that; |
| long inode = INODES_RESERVED; |
| |
| while (current) { |
| ++inode; |
| // Since we can't hardlink to directories, we know their link count. |
| if (S_ISDIR(current->st.st_mode)) current->st.st_nlink = 2; |
| else { |
| dev_t new = current->st.st_dev; |
| |
| if (!new) continue; |
| |
| // Look for other copies of current node |
| current->st.st_nlink = 0; |
| for (that = tree; that; that = treenext(that)) { |
| if (current->st.st_ino == that->st.st_ino && |
| current->st.st_dev == that->st.st_dev) |
| { |
| current->st.st_nlink++; |
| current->st.st_ino = inode; |
| } |
| } |
| } |
| current->st.st_ino = inode; |
| current = treenext(current); |
| } |
| } |
| |
| // Calculate inodes per group from total inodes. |
| static uint32_t get_inodespg(uint32_t inodes) |
| { |
| uint32_t temp; |
| |
| // Round up to fill complete inode blocks. |
| temp = (inodes + TT.groups - 1) / TT.groups; |
| inodes = TT.blocksize/sizeof(struct ext2_inode); |
| return ((temp + inodes - 1)/inodes)*inodes; |
| } |
| |
| // Fill out superblock and TT structures. |
| |
| static void init_superblock(struct ext2_superblock *sb) |
| { |
| uint32_t temp; |
| |
| // Set log_block_size and log_frag_size. |
| |
| for (temp = 0; temp < 4; temp++) if (TT.blocksize == 1024<<temp) break; |
| if (temp==4) error_exit("bad blocksize"); |
| sb->log_block_size = sb->log_frag_size = SWAP_LE32(temp); |
| |
| // Fill out blocks_count, r_blocks_count, first_data_block |
| |
| sb->blocks_count = SWAP_LE32(TT.blocks); |
| sb->free_blocks_count = SWAP_LE32(TT.freeblocks); |
| temp = (TT.blocks * (uint64_t)TT.reserved_percent) / 100; |
| sb->r_blocks_count = SWAP_LE32(temp); |
| |
| sb->first_data_block = SWAP_LE32(TT.blocksize == 1024 ? 1 : 0); |
| |
| // 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)? |
| |
| sb->blocks_per_group = sb->frags_per_group = SWAP_LE32(TT.blockbits); |
| |
| // Set inodes_per_group and total inodes_count |
| sb->inodes_per_group = SWAP_LE32(TT.inodespg); |
| sb->inodes_count = SWAP_LE32(TT.inodespg * TT.groups); |
| |
| // Determine free inodes. |
| temp = TT.inodespg*TT.groups - INODES_RESERVED; |
| if (temp < TT.treeinodes) error_exit("Not enough inodes.\n"); |
| sb->free_inodes_count = SWAP_LE32(temp - TT.treeinodes); |
| |
| // 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); |
| sb->state = sb->errors = SWAP_LE16(1); |
| |
| sb->rev_level = SWAP_LE32(1); |
| sb->first_ino = SWAP_LE32(INODES_RESERVED+1); |
| sb->inode_size = SWAP_LE16(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); |
| |
| // TODO If we're called as mke3fs or mkfs.ext3, do a journal. |
| |
| //if (strchr(toys.which->name,'3')) |
| // sb->feature_compat |= SWAP_LE32(EXT3_FEATURE_COMPAT_HAS_JOURNAL); |
| } |
| |
| // Does this group contain a superblock backup (and group descriptor table)? |
| static int is_sb_group(uint32_t group) |
| { |
| int i; |
| |
| // Superblock backups are on groups 0, 1, and powers of 3, 5, and 7. |
| if(!group || group==1) return 1; |
| for (i=3; i<9; i+=2) { |
| int j = i; |
| while (j<group) j*=i; |
| if (j==group) return 1; |
| } |
| return 0; |
| } |
| |
| |
| // Number of blocks used in group by optional superblock/group list backup. |
| static int group_superblock_overhead(uint32_t group) |
| { |
| int used; |
| |
| if (!is_sb_group(group)) return 0; |
| |
| // How many blocks does the group descriptor table take up? |
| used = TT.groups * sizeof(struct ext2_group); |
| used += TT.blocksize - 1; |
| used /= TT.blocksize; |
| // Plus the superblock itself. |
| used++; |
| // And a corner case. |
| if (!group && TT.blocksize == 1024) used++; |
| |
| return used; |
| } |
| |
| // Number of blocks used in group to store superblock/group/inode list |
| static int group_overhead(uint32_t group) |
| { |
| // Return superblock backup overhead (if any), plus block/inode |
| // allocation bitmaps, plus inode tables. |
| return group_superblock_overhead(group) + 2 + get_inodespg(TT.inodespg) |
| / (TT.blocksize/sizeof(struct ext2_inode)); |
| } |
| |
| // In bitmap "array" set "len" bits starting at position "start" (from 0). |
| static void bits_set(char *array, int start, int len) |
| { |
| while(len) { |
| if ((start&7) || len<8) { |
| array[start/8]|=(1<<(start&7)); |
| start++; |
| len--; |
| } else { |
| array[start/8]=255; |
| start+=8; |
| len-=8; |
| } |
| } |
| } |
| |
| // Seek past len bytes (to maintain sparse file), or write zeroes if output |
| // not seekable |
| static void put_zeroes(int len) |
| { |
| if(-1 == lseek(TT.fsfd, len, SEEK_SET)) { |
| memset(toybuf, 0, sizeof(toybuf)); |
| while (len) { |
| int out = len > sizeof(toybuf) ? sizeof(toybuf) : len; |
| xwrite(TT.fsfd, toybuf, out); |
| len -= out; |
| } |
| } |
| } |
| |
| // Fill out an inode structure from struct stat info in dirtree. |
| static void fill_inode(struct ext2_inode *in, struct dirtree *that) |
| { |
| uint32_t fbu[15]; |
| int temp; |
| |
| file_blocks_used(that->st.st_size, fbu); |
| |
| // If that inode needs data blocks allocated to it. |
| if (that->st.st_size) { |
| int i, group = TT.nextblock/TT.blockbits; |
| |
| // TODO: teach this about indirect blocks. |
| for (i=0; i<15; i++) { |
| // If we just jumped into a new group, skip group overhead blocks. |
| while (group >= TT.nextgroup) |
| TT.nextblock += group_overhead(TT.nextgroup++); |
| } |
| } |
| // TODO : S_ISREG/DIR/CHR/BLK/FIFO/LNK/SOCK(m) |
| in->mode = SWAP_LE32(that->st.st_mode); |
| |
| in->uid = SWAP_LE16(that->st.st_uid & 0xFFFF); |
| in->uid_high = SWAP_LE16(that->st.st_uid >> 16); |
| in->gid = SWAP_LE16(that->st.st_gid & 0xFFFF); |
| in->gid_high = SWAP_LE16(that->st.st_gid >> 16); |
| in->size = SWAP_LE32(that->st.st_size & 0xFFFFFFFF); |
| |
| // Contortions to make the compiler not generate a warning for x>>32 |
| // when x is 32 bits. The optimizer should clean this up. |
| if (sizeof(that->st.st_size) > 4) temp = 32; |
| else temp = 0; |
| if (temp) in->dir_acl = SWAP_LE32(that->st.st_size >> temp); |
| |
| in->atime = SWAP_LE32(that->st.st_atime); |
| in->ctime = SWAP_LE32(that->st.st_ctime); |
| in->mtime = SWAP_LE32(that->st.st_mtime); |
| |
| in->links_count = SWAP_LE16(that->st.st_nlink); |
| in->blocks = SWAP_LE32(that->st.st_blocks); |
| // in->faddr |
| } |
| |
| // Works like an archiver. |
| // The first argument is the name of the file to create. If it already |
| // exists, that size will be used. |
| |
| void mke2fs_main(void) |
| { |
| int i, temp; |
| off_t length; |
| uint32_t usedblocks, usedinodes, dtbblk; |
| struct dirtree *dti, *dtb; |
| struct ext2_superblock sb; |
| |
| // Handle command line arguments. |
| |
| if (toys.optargs[1]) { |
| sscanf(toys.optargs[1], "%u", &TT.blocks); |
| temp = O_RDWR|O_CREAT; |
| } else temp = O_RDWR; |
| if (!TT.reserved_percent) TT.reserved_percent = 5; |
| |
| // TODO: Check if filesystem is mounted here |
| |
| // For mke?fs, open file. For gene?fs, create file. |
| TT.fsfd = xcreate(*toys.optargs, temp, 0777); |
| |
| // Determine appropriate block size and block count from file length. |
| // (If no length, default to 4k. They can override it on the cmdline.) |
| |
| length = fdlength(TT.fsfd); |
| if (!TT.blocksize) TT.blocksize = (length && length < 1<<29) ? 1024 : 4096; |
| TT.blockbits = 8*TT.blocksize; |
| if (!TT.blocks) TT.blocks = length/TT.blocksize; |
| |
| // Collect gene2fs list or lost+found, calculate requirements. |
| |
| if (TT.gendir) { |
| strncpy(toybuf, TT.gendir, sizeof(toybuf)); |
| dti = dirtree_read(toybuf, dirtree_notdotdot); |
| } else { |
| dti = xzalloc(sizeof(struct dirtree)+11); |
| strcpy(dti->name, "lost+found"); |
| dti->st.st_mode = S_IFDIR|0755; |
| dti->st.st_ctime = dti->st.st_mtime = time(NULL); |
| } |
| |
| // Add root directory inode. This is iterated through for when finding |
| // blocks, but not when finding inodes. The tree's parent pointers don't |
| // point back into this. |
| |
| dtb = xzalloc(sizeof(struct dirtree)+1); |
| dtb->st.st_mode = S_IFDIR|0755; |
| dtb->st.st_ctime = dtb->st.st_mtime = time(NULL); |
| dtb->child = dti; |
| |
| // Figure out how much space is used by preset files |
| length = check_treesize(dtb, &(dtb->st.st_size)); |
| check_treelinks(dtb); |
| |
| // Figure out how many total 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; |
| } |
| |
| // If we're generating a filesystem and have no idea how many blocks it |
| // needs, start with a minimal guess, find the overhead of that many |
| // groups, and loop until this is enough groups to store this many blocks. |
| if (!TT.blocks) TT.groups = (TT.treeblocks/TT.blockbits)+1; |
| else TT.groups = div_round_up(TT.blocks, TT.blockbits); |
| |
| for (;;) { |
| temp = TT.treeblocks; |
| |
| for (i = 0; i<TT.groups; i++) temp += group_overhead(i); |
| |
| if (TT.blocks) { |
| if (TT.blocks < temp) error_exit("Not enough space.\n"); |
| break; |
| } |
| if (temp <= TT.groups * TT.blockbits) { |
| TT.blocks = temp; |
| break; |
| } |
| TT.groups++; |
| } |
| TT.freeblocks = TT.blocks - temp; |
| |
| // Now we know all the TT data, initialize superblock structure. |
| |
| init_superblock(&sb); |
| |
| // Start writing. Skip the first 1k to avoid the boot sector (if any). |
| put_zeroes(1024); |
| |
| // Loop through block groups, write out each one. |
| dtbblk = usedblocks = usedinodes = 0; |
| for (i=0; i<TT.groups; i++) { |
| struct ext2_inode *in = (struct ext2_inode *)toybuf; |
| uint32_t start, itable, used, end; |
| int j, slot; |
| |
| // Where does this group end? |
| end = TT.blockbits; |
| if ((i+1)*TT.blockbits > TT.blocks) end = TT.blocks & (TT.blockbits-1); |
| |
| // Blocks used by inode table |
| itable = (TT.inodespg*sizeof(struct ext2_inode))/TT.blocksize; |
| |
| // If a superblock goes here, write it out. |
| start = group_superblock_overhead(i); |
| if (start) { |
| struct ext2_group *bg = (struct ext2_group *)toybuf; |
| int treeblocks = TT.treeblocks, treeinodes = TT.treeinodes; |
| |
| sb.block_group_nr = SWAP_LE16(i); |
| |
| // Write superblock and pad it up to block size |
| xwrite(TT.fsfd, &sb, sizeof(struct ext2_superblock)); |
| temp = TT.blocksize - sizeof(struct ext2_superblock); |
| if (!i && TT.blocksize > 1024) temp -= 1024; |
| memset(toybuf, 0, TT.blocksize); |
| xwrite(TT.fsfd, toybuf, temp); |
| |
| // Loop through groups to write group descriptor table. |
| for(j=0; j<TT.groups; j++) { |
| |
| // Figure out what sector this group starts in. |
| used = group_superblock_overhead(j); |
| |
| // Find next array slot in this block (flush block if full). |
| slot = j % (TT.blocksize/sizeof(struct ext2_group)); |
| if (!slot) { |
| if (j) xwrite(TT.fsfd, bg, TT.blocksize); |
| memset(bg, 0, TT.blocksize); |
| } |
| |
| // How many free inodes in this group? |
| temp = TT.inodespg; |
| if (!i) temp -= INODES_RESERVED; |
| if (temp > treeinodes) { |
| treeinodes -= temp; |
| temp = 0; |
| } else { |
| temp -= treeinodes; |
| treeinodes = 0; |
| } |
| bg[slot].free_inodes_count = SWAP_LE16(temp); |
| |
| // How many free blocks in this group? |
| temp = TT.inodespg/(TT.blocksize/sizeof(struct ext2_inode)) + 2; |
| temp = end-used-temp; |
| if (temp > treeblocks) { |
| treeblocks -= temp; |
| temp = 0; |
| } else { |
| temp -= treeblocks; |
| treeblocks = 0; |
| } |
| bg[slot].free_blocks_count = SWAP_LE32(temp); |
| |
| // Fill out rest of group structure |
| used += j*TT.blockbits; |
| bg[slot].block_bitmap = SWAP_LE32(used++); |
| bg[slot].inode_bitmap = SWAP_LE32(used++); |
| bg[slot].inode_table = SWAP_LE32(used); |
| bg[slot].used_dirs_count = 0; // (TODO) |
| } |
| xwrite(TT.fsfd, bg, TT.blocksize); |
| } |
| |
| // Now write out stuff that every block group has. |
| |
| // Write block usage bitmap |
| |
| start += 2 + itable; |
| memset(toybuf, 0, TT.blocksize); |
| bits_set(toybuf, 0, start); |
| bits_set(toybuf, end, TT.blockbits-end); |
| temp = TT.treeblocks - usedblocks; |
| if (temp) { |
| if (end-start > temp) temp = end-start; |
| bits_set(toybuf, start, temp); |
| } |
| xwrite(TT.fsfd, toybuf, TT.blocksize); |
| |
| // Write inode bitmap |
| memset(toybuf, 0, TT.blocksize); |
| j = 0; |
| if (!i) bits_set(toybuf, 0, j = INODES_RESERVED); |
| bits_set(toybuf, TT.inodespg, slot = TT.blockbits-TT.inodespg); |
| temp = TT.treeinodes - usedinodes; |
| if (temp) { |
| if (slot-j > temp) temp = slot-j; |
| bits_set(toybuf, j, temp); |
| } |
| xwrite(TT.fsfd, toybuf, TT.blocksize); |
| |
| // Write inode table for this group (TODO) |
| for (j = 0; j<TT.inodespg; j++) { |
| slot = j % (TT.blocksize/sizeof(struct ext2_inode)); |
| if (!slot) { |
| if (j) xwrite(TT.fsfd, in, TT.blocksize); |
| memset(in, 0, TT.blocksize); |
| } |
| if (!i && j<INODES_RESERVED) { |
| // Write root inode |
| if (j == 2) fill_inode(in+slot, dtb); |
| } else if (dti) { |
| fill_inode(in+slot, dti); |
| dti = treenext(dti); |
| } |
| } |
| xwrite(TT.fsfd, in, TT.blocksize); |
| |
| while (dtb) { |
| // TODO write index data block |
| // TODO write root directory data block |
| // TODO write directory data block |
| // TODO write file data block |
| put_zeroes(TT.blocksize); |
| start++; |
| if (start == end) break; |
| } |
| // Write data blocks (TODO) |
| put_zeroes((end-start) * TT.blocksize); |
| } |
| } |