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-rw-r--r--toys/pending/mke2fs.c656
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+/* 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 (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
+*/
+
+#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).
+
+ struct ext2_superblock sb;
+)
+
+#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);
+ }
+}
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