#define TT toy.mke2fs
- // b - block size (1024, 2048, 4096)
- // F - force (run on mounted device or non-block device)
- // i - bytes per inode
- // N - number of inodes
- // m - reserved blocks percentage
- // n - Don't write
- // q - quiet
-
- // L - volume label
- // M - last mounted path
- // o - creator os
-
- // j - create journal
- // J - journal options (size=1024-102400 blocks,device=)
- // device=/dev/blah or LABEL=label UUID=uuid
+#define INODES_RESERVED 10
- // E - extended options (stride=stripe-size blocks)
- // O - none,dir_index,filetype,has_journal,journal_dev,sparse_super
+static uint32_t div_round_up(uint32_t a, uint32_t b)
+{
+ uint32_t c = a/b;
-#define INODES_RESERVED 10
+ if (a%b) c++;
+ return c;
+}
// Calculate data blocks plus index blocks needed to hold a file.
-static uint32_t count_blocks_used(uint64_t size)
+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.
+
+ if (blocklist) {
+ int i;
+
+ for (i=0; i<13 && i<dblocks; i++) blocklist[i] = i;
+ if (dblocks > 13+idx) blocklist[13] = 13+idx;
+ 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) {
return dblocks + iblocks + diblocks + tiblocks;
}
-// Calculate the number of blocks used by each inode. Returns blocks used,
-// assigns bytes used to *size. Writes total block count to TT.treeblocks
-// and inode count to TT.treeinodes.
+// 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 *this, off_t *size)
{
if (this->child)
this->st.st_blocks = check_treesize(this->child, &this->st.st_size);
else if (S_ISREG(this->st.st_mode)) {
- this->st.st_blocks = count_blocks_used(this->st.st_size);
+ this->st.st_blocks = file_blocks_used(this->st.st_size, 0);
TT.treeblocks += this->st.st_blocks;
}
this = this->next;
}
- TT.treeblocks += blocks = count_blocks_used(*size);
+ TT.treeblocks += blocks = file_blocks_used(*size, 0);
TT.treeinodes++;
return blocks;
}
-// 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;
-}
-
+// 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 but can be done in very little code.
+// 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(void)
+static void check_treelinks(struct dirtree *tree)
{
- struct dirtree *this, *that;
+ struct dirtree *this=tree, *that;
+ long inode = INODES_RESERVED;
- for (this = TT.dt; this; this = treenext(this)) {
+ while (this) {
+ ++inode;
// Since we can't hardlink to directories, we know their link count.
if (S_ISDIR(this->st.st_mode)) this->st.st_nlink = 2;
else {
+ dev_t new = this->st.st_dev;
+
+ if (!new) continue;
+
this->st.st_nlink = 0;
- for (that = TT.dt; that; that = treenext(that))
- if (this->st.st_ino == that->st.st_ino)
- if (this->st.st_dev == that->st.st_dev)
- this->st.st_nlink++;
+ for (that = tree; that; that = treenext(that)) {
+ if (this->st.st_ino == that->st.st_ino &&
+ this->st.st_dev == that->st.st_dev)
+ {
+ this->st.st_nlink++;
+ this->st.st_ino = inode;
+ }
+ }
}
+ this->st.st_ino = inode;
+ this = treenext(this);
}
}
// 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)
+static void fake_uuid(char *uuid)
{
// Read 128 random bits
int fd = xopen("/dev/urandom", O_RDONLY);
uuid[11] = uuid[11] | 128;
}
-// Figure out inodes per group, rounded up to fill complete inode blocks.
+// 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
+// Fill out superblock and TT structures.
static void init_superblock(struct ext2_superblock *sb)
{
// 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->blocks_per_group = sb->frags_per_group = SWAP_LE32(TT.blockbits);
- // How many block groups do we need? (Round up avoiding integer overflow.)
-
- TT.groups = (TT.blocks)/TT.blockbits;
- if (TT.blocks & (TT.blockbits-1)) TT.groups++;
-
- // Figure out inodes per group, rounded up to block size.
-
- TT.inodespg = get_inodespg(TT.inodespg);
-
// 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->feature_incompat = SWAP_LE32(EXT2_FEATURE_INCOMPAT_FILETYPE);
sb->feature_ro_compat = SWAP_LE32(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
- create_uuid(sb->uuid);
-
+ fake_uuid(sb->uuid);
+
// TODO If we're called as mke3fs or mkfs.ext3, do a journal.
//if (strchr(toys.which->name,'3'))
}
-// Number of blocks used in this group by superblock/group list backup.
-static int group_superblock_used(uint32_t group)
+// 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 blocks does the group table take up?
+ // How many blocks does the group descriptor table take up?
used = TT.groups * sizeof(struct ext2_group);
used += TT.blocksize - 1;
used /= TT.blocksize;
return used;
}
-static uint32_t get_all_group_blocks(void)
+// Number of blocks used in group to store superblock/group/inode list
+static int group_overhead(uint32_t group)
{
- uint32_t i, blocks, inodeblks;
-
- inodeblks = get_inodespg(TT.inodespg);
- inodeblks /= TT.blocksize/sizeof(struct ext2_inode);
- for (i = blocks = 0; i<TT.groups; i++)
- blocks += group_superblock_used(i) + 2 + inodeblks;
-
- return blocks;
+ // 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) {
// not seekable
static void put_zeroes(int len)
{
- if(TT.noseek || -1 == lseek(TT.fsfd, len, SEEK_SET)) {
-
- TT.noseek=1;
+ if(-1 == lseek(TT.fsfd, len, SEEK_SET)) {
memset(toybuf, 0, sizeof(toybuf));
while (len) {
int out = len > sizeof(toybuf) ? sizeof(toybuf) : len;
}
}
+// Fill out an inode structure from struct stat info in dirtree.
static void fill_inode(struct ext2_inode *in, struct dirtree *this)
{
- memset(in,0,sizeof(struct ext2_inode));
+ uint32_t fbu[15];
+ int temp;
- // This works on Linux. S_ISREG/DIR/CHR/BLK/FIFO/LNK/SOCK(m)
- in->mode = this->st.st_mode;
+ file_blocks_used(this->st.st_size, fbu);
- in->uid = this->st.st_uid & 0xFFFF;
- in->uid_high = this->st.st_uid >> 16;
- in->gid = this->st.st_gid & 0xFFFF;
- in->gid_high = this->st.st_gid >> 16;
- in->size = this->st.st_size & 0xFFFFFFFF;
+ // If this inode needs data blocks allocated to it.
+ if (this->st.st_size) {
+ int i, group = TT.nextblock/TT.blockbits;
- in->atime = this->st.st_atime;
- in->ctime = this->st.st_ctime;
- in->mtime = this->st.st_mtime;
+ // 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(this->st.st_mode);
+
+ in->uid = SWAP_LE16(this->st.st_uid & 0xFFFF);
+ in->uid_high = SWAP_LE16(this->st.st_uid >> 16);
+ in->gid = SWAP_LE16(this->st.st_gid & 0xFFFF);
+ in->gid_high = SWAP_LE16(this->st.st_gid >> 16);
+ in->size = SWAP_LE32(this->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(this->st.st_size) > 4) temp = 32;
+ else temp = 0;
+ if (temp) in->dir_acl = SWAP_LE32(this->st.st_size >> temp);
+
+ in->atime = SWAP_LE32(this->st.st_atime);
+ in->ctime = SWAP_LE32(this->st.st_ctime);
+ in->mtime = SWAP_LE32(this->st.st_mtime);
- in->links_count = this->st.st_nlink;
- in->blocks = this->st.st_blocks;
+ in->links_count = SWAP_LE16(this->st.st_nlink);
+ in->blocks = SWAP_LE32(this->st.st_blocks);
+ // in->faddr
}
int mke2fs_main(void)
{
int i, temp;
off_t length;
- uint32_t usedblocks, usedinodes;
-
+ uint32_t usedblocks, usedinodes, dtiblk, dtbblk;
+ struct dirtree *dti, *dtb;
+
// Handle command line arguments.
if (toys.optargs[1]) {
TT.blockbits = 8*TT.blocksize;
if (!TT.blocks) TT.blocks = length/TT.blocksize;
- // Figure out how many total inodes we need.
-
- if (!TT.inodespg) {
- if (!TT.bytes_per_inode) TT.bytes_per_inode = 8192;
- TT.inodespg = (TT.blocks * (uint64_t)TT.blocksize) / TT.bytes_per_inode;
- }
-
// Collect gene2fs list or lost+found, calculate requirements.
if (TT.gendir) {
strncpy(toybuf, TT.gendir, sizeof(toybuf));
- TT.dt = read_dirtree(toybuf, NULL);
+ dti = read_dirtree(toybuf, NULL);
} else {
- TT.dt = xzalloc(sizeof(struct dirtree)+11);
- strcpy(TT.dt->name, "lost+found");
- TT.dt->st.st_mode = S_IFDIR|0755;
- TT.dt->st.st_ctime = TT.dt->st.st_mtime = time(NULL);
+ 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 = 0;
- length = check_treesize(TT.dt, &length);
- check_treelinks(); // Calculate st_nlink for each node in tree.
-
- if (TT.gendir && !TT.blocks) {
- // Figure out how many blocks of overhead superblock backups and
- // group descriptor tables impose. Start with a minimal guess,
- // find the overhead for that many groups, and loop until this
- // is enough groups to store this many blocks.
- TT.groups = (TT.treeblocks/TT.blockbits)+1;
- for (;;) {
- TT.blocks = TT.treeblocks + get_all_group_blocks();
- if (TT.blocks <= TT.groups * TT.blockbits) break;
- TT.groups++;
+ 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;
- // TT.blocks is now big enough to initialize superblock structure
+ // Now we know all the TT data, initialize superblock structure.
init_superblock(&TT.sb);
- temp = get_all_group_blocks();
- if (TT.blocks < TT.treeblocks + temp) error_exit("Not enough space.\n");
- TT.sb.free_blocks_count = SWAP_LE32(TT.blocks - TT.treeblocks - temp);
- temp = TT.inodespg*TT.groups - INODES_RESERVED;
- if (temp < TT.treeinodes) error_exit("Not enough inodes.\n");
- TT.sb.free_inodes_count = SWAP_LE32(temp - TT.treeinodes);
-
- // Skip the first 1k to avoid the boot sector (if any)
+ // Start writing. Skip the first 1k to avoid the boot sector (if any).
put_zeroes(1024);
// Loop through block groups, write out each one.
- usedblocks = 0;
- usedinodes = 0;
+ 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;
itable = (TT.inodespg*sizeof(struct ext2_inode))/TT.blocksize;
// If a superblock goes here, write it out.
- start = group_superblock_used(i);
+ start = group_superblock_overhead(i);
if (start) {
struct ext2_group *bg = (struct ext2_group *)toybuf;
int treeblocks = TT.treeblocks, treeinodes = TT.treeinodes;
for(j=0; j<TT.groups; j++) {
// Figure out what sector this group starts in.
- used = group_superblock_used(j);
+ 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 (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);
- // Write empty data blocks
+ 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);
}
return 0;
}
+
+// Scratch pad:
+ // b - block size (1024, 2048, 4096)
+ // F - force (run on mounted device or non-block device)
+ // i - bytes per inode
+ // N - number of inodes
+ // m - reserved blocks percentage
+ // n - Don't write
+ // q - quiet
+
+ // L - volume label
+ // M - last mounted path
+ // o - creator os
+
+ // j - create journal
+ // J - journal options (size=1024-102400 blocks,device=)
+ // device=/dev/blah or LABEL=label UUID=uuid
+
+ // E - extended options (stride=stripe-size blocks)
+ // O - none,dir_index,filetype,has_journal,journal_dev,sparse_super
+
+
projects / platform / upstream / toybox.git / commitdiff