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Diffstat (limited to 'toys/mke2fs.c')
| -rw-r--r-- | toys/mke2fs.c | 662 |
1 files changed, 0 insertions, 662 deletions
diff --git a/toys/mke2fs.c b/toys/mke2fs.c deleted file mode 100644 index 47f31f2d..00000000 --- a/toys/mke2fs.c +++ /dev/null @@ -1,662 +0,0 @@ -/* vi: set ts=4: - * - * mke2fs.c - Create an ext2 filesystem image. - * - * Copyright 2006, 2007 Rob Landley <rob@landley.net> - * - * Not in SUSv3. - -// Still to go: "E:jJ:L:m:O:" -USE_MKE2FS(NEWTOY(mke2fs, "<1>2g:Fnqm#N#i#b#", TOYFLAG_SBIN)) - -config MKE2FS - bool "mke2fs (unfinished and broken by dirtree changes)" - 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: [-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 -*/ - -#include "toys.h" - -DEFINE_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). - - struct ext2_superblock sb; -) - -// Shortcut to our global data structure, since we use it so much. -#define TT this.mke2fs - -#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); - } -} - -// According to http://www.opengroup.org/onlinepubs/9629399/apdxa.htm -// we should generate a uuid structure by reading a clock with 100 nanosecond -// precision, normalizing it to the start of the gregorian calendar in 1582, -// and looking up our eth0 mac address. -// -// On the other hand, we have 128 bits to come up with a unique identifier, of -// which 6 have a defined value. /dev/urandom it is. - -static void create_uuid(char *uuid) -{ - // Read 128 random bits - int fd = xopen("/dev/urandom", O_RDONLY); - xreadall(fd, uuid, 16); - close(fd); - - // Claim to be a DCE format UUID. - uuid[6] = (uuid[6] & 0x0F) | 0x40; - uuid[8] = (uuid[8] & 0x3F) | 0x80; - - // rfc2518 section 6.4.1 suggests if we're not using a macaddr, we should - // set bit 1 of the node ID, which is the mac multicast bit. This means we - // should never collide with anybody actually using a macaddr. - uuid[11] = uuid[11] | 128; -} - -// 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, dtiblk, dtbblk; - struct dirtree *dti, *dtb; - - // 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, NULL, NULL); - } 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(&TT.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. - dtiblk = 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; - - TT.sb.block_group_nr = SWAP_LE16(i); - - // Write superblock and pad it up to block size - xwrite(TT.fsfd, &TT.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); - } -} |