#include "libbb.h"
#include <linux/fs.h>
#include <linux/ext2_fs.h>
-#include <sys/user.h> /* PAGE_SIZE */
-#ifndef PAGE_SIZE
-# define PAGE_SIZE 4096
-#endif
-#include "volume_id/volume_id_internal.h"
#define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
-#define ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX 1
+#define ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX 1
// from e2fsprogs
#define s_reserved_gdt_blocks s_padding1
#define s_mkfs_time s_reserved[0]
#define s_flags s_reserved[22]
-#define EXT2_HASH_HALF_MD4 1
-#define EXT2_FLAGS_SIGNED_HASH 0x0001
-// whiteout: for writable overlays
-//#define LINUX_S_IFWHT 0160000
-//#define EXT2_FEATURE_INCOMPAT_WHITEOUT 0x0020
+#define EXT2_HASH_HALF_MD4 1
+#define EXT2_FLAGS_SIGNED_HASH 0x0001
+#define EXT2_FLAGS_UNSIGNED_HASH 0x0002
// storage helpers
char BUG_wrong_field_size(void);
#define STORE_LE(field, value) \
do { \
if (sizeof(field) == 4) \
- field = cpu_to_le32(value); \
+ field = SWAP_LE32(value); \
else if (sizeof(field) == 2) \
- field = cpu_to_le16(value); \
+ field = SWAP_LE16(value); \
else if (sizeof(field) == 1) \
field = (value); \
else \
} while (0)
#define FETCH_LE32(field) \
- (sizeof(field) == 4 ? cpu_to_le32(field) : BUG_wrong_field_size())
+ (sizeof(field) == 4 ? SWAP_LE32(field) : BUG_wrong_field_size())
// All fields are little-endian
struct ext2_dir {
}
// taken from mkfs_minix.c. libbb candidate?
-static unsigned div_roundup(uint64_t size, uint32_t n)
+// "uint32_t size", since we never use it for anything >32 bits
+static uint32_t div_roundup(uint32_t size, uint32_t n)
{
// Overflow-resistant
- uint64_t res = size / n;
+ uint32_t res = size / n;
if (res * n != size)
res++;
return res;
static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32_t end)
{
uint32_t i;
+
+//bb_info_msg("ALLOC: [%u][%u][%u]: [%u-%u]:=[%x],[%x]", blocksize, start, end, start/8, blocksize - end/8 - 1, (1 << (start & 7)) - 1, (uint8_t)(0xFF00 >> (end & 7)));
memset(bitmap, 0, blocksize);
i = start / 8;
memset(bitmap, 0xFF, i);
- bitmap[i] = 0xFF >> (8 - (start & 7));
-//bb_info_msg("ALLOC: [%u][%u][%u]: [%u-%u]:=[%x],[%x]", blocksize, start, end, start/8, blocksize - end/8 - 1, 0xFF >> (8 - (start & 7)), (uint8_t)(0xFF << (8-(end&7))));
+ bitmap[i] = (1 << (start & 7)) - 1; //0..7 => 00000000..01111111
i = end / 8;
- bitmap[blocksize - i - 1] = 0xFF << (8 - (end & 7));
+ bitmap[blocksize - i - 1] |= 0x7F00 >> (end & 7); //0..7 => 00000000..11111110
memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
}
}
}
-/* Standard mke2fs 1.41.9:
- * Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size]
- * [-i bytes-per-inode] [-I inode-size] [-J journal-options]
- * [-G meta group size] [-N number-of-inodes]
- * [-m reserved-blocks-percentage] [-o creator-os]
- * [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
- * [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
- * [-T fs-type] [-U UUID] [-jnqvFSV] device [blocks-count]
-*/
-// N.B. not commented below options are taken and silently ignored
+#define fd 3 /* predefined output descriptor */
+
+static void PUT(uint64_t off, void *buf, uint32_t size)
+{
+// bb_info_msg("PUT[%llu]:[%u]", off, size);
+ xlseek(fd, off, SEEK_SET);
+ xwrite(fd, buf, size);
+}
+
+// 128 and 256-byte inodes:
+// 128-byte inode is described by struct ext2_inode.
+// 256-byte one just has these fields appended:
+// __u16 i_extra_isize;
+// __u16 i_pad1;
+// __u32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */
+// __u32 i_mtime_extra; /* extra Modification time (nsec << 2 | epoch) */
+// __u32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
+// __u32 i_crtime; /* File creation time */
+// __u32 i_crtime_extra; /* extra File creation time (nsec << 2 | epoch)*/
+// __u32 i_version_hi; /* high 32 bits for 64-bit version */
+// the rest is padding.
+//
+// linux/ext2_fs.h has "#define i_size_high i_dir_acl" which suggests that even
+// 128-byte inode is capable of describing large files (i_dir_acl is meaningful
+// only for directories, which never need i_size_high).
+//
+// Standard mke2fs creates a filesystem with 256-byte inodes if it is
+// bigger than 0.5GB.
+
+// Standard mke2fs 1.41.9:
+// Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size]
+// [-i bytes-per-inode] [-I inode-size] [-J journal-options]
+// [-G meta group size] [-N number-of-inodes]
+// [-m reserved-blocks-percentage] [-o creator-os]
+// [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
+// [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
+// [-T fs-type] [-U UUID] [-jnqvFSV] device [blocks-count]
+//
+// Options not commented below are taken but silently ignored:
enum {
OPT_c = 1 << 0,
OPT_l = 1 << 1,
OPT_b = 1 << 2, // block size, in bytes
OPT_f = 1 << 3,
OPT_i = 1 << 4, // bytes per inode
- OPT_I = 1 << 5,
+ OPT_I = 1 << 5, // custom inode size, in bytes
OPT_J = 1 << 6,
OPT_G = 1 << 7,
OPT_N = 1 << 8,
//OPT_V = 1 << 25, // -V version. bbox applets don't support that
};
-#define fd 3 /* predefined output descriptor */
-
-static void PUT(uint64_t off, void *buf, uint32_t size)
-{
-// bb_info_msg("PUT[%llu]:[%u]", off, size);
- xlseek(fd, off, SEEK_SET);
- xwrite(fd, buf, size);
-}
-
int mkfs_ext2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
{
unsigned i, pos, n;
unsigned bs, bpi;
unsigned blocksize, blocksize_log2;
- unsigned nreserved = 5;
+ unsigned inodesize, user_inodesize;
+ unsigned reserved_percent = 5;
unsigned long long kilobytes;
uint32_t nblocks, nblocks_full;
+ uint32_t nreserved;
uint32_t ngroups;
uint32_t bytes_per_inode;
- uint32_t first_data_block;
+ uint32_t first_block;
uint32_t inodes_per_group;
- uint32_t gdtsz, itsz;
+ uint32_t group_desc_blocks;
+ uint32_t inode_table_blocks;
+ uint32_t lost_and_found_blocks;
time_t timestamp;
- unsigned opts;
const char *label = "";
struct stat st;
struct ext2_super_block *sb; // superblock
struct ext2_dir *dir;
uint8_t *buf;
- opt_complementary = "-1:b+:m+:i+";
- opts = getopt32(argv, "cl:b:f:i:I:J:G:N:m:o:g:L:M:O:r:E:T:U:jnqvFS",
- NULL, &bs, NULL, &bpi, NULL, NULL, NULL, NULL,
- &nreserved, NULL, NULL, &label, NULL, NULL, NULL, NULL, NULL, NULL);
+ // using global "option_mask32" instead of local "opts":
+ // we are register starved here
+ opt_complementary = "-1:b+:i+:I+:m+";
+ /*opts =*/ getopt32(argv, "cl:b:f:i:I:J:G:N:m:o:g:L:M:O:r:E:T:U:jnqvFS",
+ /*lbfi:*/ NULL, &bs, NULL, &bpi,
+ /*IJGN:*/ &user_inodesize, NULL, NULL, NULL,
+ /*mogL:*/ &reserved_percent, NULL, NULL, &label,
+ /*MOrE:*/ NULL, NULL, NULL, NULL,
+ /*TU:*/ NULL, NULL);
argv += optind; // argv[0] -- device
- // reserved blocks percentage
- if (nreserved > 50)
- bb_error_msg_and_die("-%c is bad", 'm');
-
- // check the device is a block device
+ // open the device, check the device is a block device
xmove_fd(xopen(argv[0], O_WRONLY), fd);
fstat(fd, &st);
- if (!S_ISBLK(st.st_mode) && !(opts & OPT_F))
- bb_error_msg_and_die("not a block device");
+ if (!S_ISBLK(st.st_mode) && !(option_mask32 & OPT_F))
+ bb_error_msg_and_die("%s: not a block device", argv[0]);
// check if it is mounted
// N.B. what if we format a file? find_mount_point will return false negative since
- // it is loop block device which mounted!
+ // it is loop block device which is mounted!
if (find_mount_point(argv[0], 0))
bb_error_msg_and_die("can't format mounted filesystem");
- // open the device, get size in kbytes
- if (argv[1]) {
- kilobytes = xatoull(argv[1]);
- } else {
- kilobytes = (uoff_t)xlseek(fd, 0, SEEK_END) / 1024;
- }
+ // get size in kbytes
+ kilobytes = get_volume_size_in_bytes(fd, argv[1], 1024, /*extend:*/ !(option_mask32 & OPT_n)) / 1024;
bytes_per_inode = 16384;
if (kilobytes < 512*1024)
bytes_per_inode = 4096;
if (kilobytes < 3*1024)
bytes_per_inode = 8192;
- if (opts & OPT_i)
+ if (option_mask32 & OPT_i)
bytes_per_inode = bpi;
+ // Determine block size and inode size
// block size is a multiple of 1024
+ // inode size is a multiple of 128
blocksize = 1024;
- if (kilobytes >= 512*1024) // mke2fs 1.41.9 compat
+ inodesize = sizeof(struct ext2_inode); // 128
+ if (kilobytes >= 512*1024) { // mke2fs 1.41.9 compat
blocksize = 4096;
+ inodesize = 256;
+ }
if (EXT2_MAX_BLOCK_SIZE > 4096) {
// kilobytes >> 22 == size in 4gigabyte chunks.
- // if it is >= 16k gigs, blocksize must be increased.
- // Try "mke2fs -F image_std $((16 * 1024*1024*1024))"
+ // if size >= 16k gigs, blocksize must be increased.
+ // Try "mke2fs -F image $((16 * 1024*1024*1024))"
while ((kilobytes >> 22) >= blocksize)
blocksize *= 2;
}
- if (opts & OPT_b)
+ if (option_mask32 & OPT_b)
blocksize = bs;
if (blocksize < EXT2_MIN_BLOCK_SIZE
|| blocksize > EXT2_MAX_BLOCK_SIZE
) {
bb_error_msg_and_die("blocksize %u is bad", blocksize);
}
+ // Do we have custom inode size?
+ if (option_mask32 & OPT_I) {
+ if (user_inodesize < sizeof(*inode)
+ || user_inodesize > blocksize
+ || (user_inodesize & (user_inodesize - 1)) // not power of 2
+ ) {
+ bb_error_msg("-%c is bad", 'I');
+ } else {
+ inodesize = user_inodesize;
+ }
+ }
+
+ if ((int32_t)bytes_per_inode < blocksize)
+ bb_error_msg_and_die("-%c is bad", 'i');
+ // number of bits in one block, i.e. 8*blocksize
+#define blocks_per_group (8 * blocksize)
+ first_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
blocksize_log2 = int_log2(blocksize);
+
+ // Determine number of blocks
kilobytes >>= (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
- // nblocks: the total number of blocks in the filesystem
nblocks = kilobytes;
if (nblocks != kilobytes)
bb_error_msg_and_die("block count doesn't fit in 32 bits");
#define kilobytes kilobytes_unused_after_this
+ // Experimentally, standard mke2fs won't work on images smaller than 60k
+ if (nblocks < 60)
+ bb_error_msg_and_die("need >= 60 blocks");
- if (blocksize < PAGE_SIZE)
- nblocks &= ~((PAGE_SIZE / blocksize)-1);
+ // How many reserved blocks?
+ if (reserved_percent > 50)
+ bb_error_msg_and_die("-%c is bad", 'm');
+ nreserved = (uint64_t)nblocks * reserved_percent / 100;
// N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
- nblocks_full = nblocks;
- retry:
- if (nblocks < 8)
- bb_error_msg_and_die("need >= 8 blocks");
-
- // number of bits in one block, i.e. 8*blocksize
-#define blocks_per_group (8 * blocksize)
+ nblocks_full = nblocks;
+ // If last block group is too small, nblocks may be decreased in order
+ // to discard it, and control returns here to recalculate some
+ // parameters.
+ // Note: blocksize and bytes_per_inode are never recalculated.
+ retry:
// N.B. a block group can have no more than blocks_per_group blocks
- first_data_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
- ngroups = div_roundup(nblocks - first_data_block, blocks_per_group);
- if (0 == ngroups)
- bb_error_msg_and_die("ngroups");
+ ngroups = div_roundup(nblocks - first_block, blocks_per_group);
- gdtsz = div_roundup(ngroups, blocksize / sizeof(*gd));
+ group_desc_blocks = div_roundup(ngroups, blocksize / sizeof(*gd));
// TODO: reserved blocks must be marked as such in the bitmaps,
// or resulting filesystem is corrupt
if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
* We set it at 1024x the current filesystem size, or
* the upper block count limit (2^32), whichever is lower.
*/
- uint32_t rgdtsz = 0xFFFFFFFF; // maximum block number
- if (nblocks < rgdtsz / 1024)
- rgdtsz = nblocks * 1024;
- rgdtsz = div_roundup(rgdtsz - first_data_block, blocks_per_group);
- rgdtsz = div_roundup(rgdtsz, blocksize / sizeof(*gd)) - gdtsz;
- if (rgdtsz > blocksize / sizeof(uint32_t))
- rgdtsz = blocksize / sizeof(uint32_t);
- //TODO: STORE_LE(sb->s_reserved_gdt_blocks, rgdtsz);
- gdtsz += rgdtsz;
+ uint32_t reserved_group_desc_blocks = 0xFFFFFFFF; // maximum block number
+ if (nblocks < reserved_group_desc_blocks / 1024)
+ reserved_group_desc_blocks = nblocks * 1024;
+ reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks - first_block, blocks_per_group);
+ reserved_group_desc_blocks = div_roundup(reserved_group_desc_blocks, blocksize / sizeof(*gd)) - group_desc_blocks;
+ if (reserved_group_desc_blocks > blocksize / sizeof(uint32_t))
+ reserved_group_desc_blocks = blocksize / sizeof(uint32_t);
+ //TODO: STORE_LE(sb->s_reserved_gdt_blocks, reserved_group_desc_blocks);
+ group_desc_blocks += reserved_group_desc_blocks;
}
{
// N.B. e2fsprogs does as follows!
- // ninodes is the total number of inodes (files) in the file system
- uint32_t ninodes = nblocks_full / (blocksize >= 4096 ? 1 : 4096 / blocksize);
uint32_t overhead, remainder;
+ // ninodes is the max number of inodes in this filesystem
+ uint32_t ninodes = ((uint64_t) nblocks_full * blocksize) / bytes_per_inode;
if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
inodes_per_group = div_roundup(ninodes, ngroups);
// minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
if (inodes_per_group < 16)
inodes_per_group = 16;
-
- // N.B. a block group can have no more than 8*blocksize inodes
+ // a block group can't have more inodes than blocks
if (inodes_per_group > blocks_per_group)
inodes_per_group = blocks_per_group;
// adjust inodes per group so they completely fill the inode table blocks in the descriptor
- inodes_per_group = (div_roundup(inodes_per_group * sizeof(*inode), blocksize) << blocksize_log2) / sizeof(*inode);
+ inodes_per_group = (div_roundup(inodes_per_group * inodesize, blocksize) * blocksize) / inodesize;
// make sure the number of inodes per group is a multiple of 8
inodes_per_group &= ~7;
- itsz = div_roundup(inodes_per_group * sizeof(*inode), blocksize);
-
- // the last block needs more attention: doesn't it too small for possible overhead?
- overhead = (has_super(ngroups - 1) ? (1/*sb*/ + gdtsz) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
- remainder = (nblocks - first_data_block) % blocks_per_group;
- if ((1 == ngroups) && remainder && (remainder < overhead))
- bb_error_msg_and_die("way small device");
+ inode_table_blocks = div_roundup(inodes_per_group * inodesize, blocksize);
+
+ // to be useful, lost+found should occupy at least 2 blocks (but not exceeding 16*1024 bytes),
+ // and at most EXT2_NDIR_BLOCKS. So reserve these blocks right now
+ /* Or e2fsprogs comment verbatim (what does it mean?):
+ * Ensure that lost+found is at least 2 blocks, so we always
+ * test large empty blocks for big-block filesystems. */
+ lost_and_found_blocks = MIN(EXT2_NDIR_BLOCKS, 16 >> (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE));
+
+ // the last group needs more attention: isn't it too small for possible overhead?
+ overhead = (has_super(ngroups - 1) ? (1/*sb*/ + group_desc_blocks) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
+ remainder = (nblocks - first_block) % blocks_per_group;
+ ////can't happen, nblocks >= 60 guarantees this
+ ////if ((1 == ngroups)
+ //// && remainder
+ //// && (remainder < overhead + 1/* "/" */ + lost_and_found_blocks)
+ ////) {
+ //// bb_error_msg_and_die("way small device");
+ ////}
+
+ // Standard mke2fs uses 50. Looks like a bug in our calculation
+ // of "remainder" or "overhead" - we don't match standard mke2fs
+ // when we transition from one group to two groups
+ // (a bit after 8M image size), but it works for two->three groups
+ // transition (at 16M).
if (remainder && (remainder < overhead + 50)) {
//bb_info_msg("CHOP[%u]", remainder);
nblocks -= remainder;
}
}
- // print info
if (nblocks_full - nblocks)
printf("warning: %u blocks unused\n\n", nblocks_full - nblocks);
printf(
, blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
, blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
, inodes_per_group * ngroups, nblocks
- //, div_roundup((uint64_t) nblocks * nreserved, 100), nreserved
- , (unsigned)((uint64_t) nblocks_full * nreserved / 100), nreserved
- , first_data_block
- , gdtsz * (blocksize / sizeof(*gd)) * blocks_per_group
+ , nreserved, reserved_percent
+ , first_block
+ , group_desc_blocks * (blocksize / (unsigned)sizeof(*gd)) * blocks_per_group
, ngroups
, blocks_per_group, blocks_per_group
, inodes_per_group
{
const char *fmt = "\nSuperblock backups stored on blocks:\n"
"\t%u";
- pos = first_data_block;
+ pos = first_block;
for (i = 1; i < ngroups; i++) {
pos += blocks_per_group;
if (has_super(i)) {
}
bb_putchar('\n');
- // dry run? -> we are done
- if (opts & OPT_n)
- goto done;
+ if (option_mask32 & OPT_n) {
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(fd);
+ return EXIT_SUCCESS;
+ }
// TODO: 3/5 refuse if mounted
// TODO: 4/5 compat options
// TODO: 3/5 dir_index?
// fill the superblock
- sb = xzalloc(blocksize);
- STORE_LE(sb->s_rev_level, 1); // revision 1 filesystem
+ sb = xzalloc(1024);
+ STORE_LE(sb->s_rev_level, EXT2_DYNAMIC_REV); // revision 1 filesystem
STORE_LE(sb->s_magic, EXT2_SUPER_MAGIC);
- STORE_LE(sb->s_inode_size, sizeof(*inode));
+ STORE_LE(sb->s_inode_size, inodesize);
+ // set "Required extra isize" and "Desired extra isize" fields to 28
+ if (inodesize != sizeof(*inode))
+ STORE_LE(sb->s_reserved[21], 0x001C001C);
STORE_LE(sb->s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
STORE_LE(sb->s_log_block_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
STORE_LE(sb->s_log_frag_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
// first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
- // the first block available for data is 1, otherwise 0
- STORE_LE(sb->s_first_data_block, first_data_block); // 0 or 1
+ // the first block is 1, otherwise 0
+ STORE_LE(sb->s_first_data_block, first_block);
// block and inode bitmaps occupy no more than one block, so maximum number of blocks is
STORE_LE(sb->s_blocks_per_group, blocks_per_group);
STORE_LE(sb->s_frags_per_group, blocks_per_group);
// blocks
STORE_LE(sb->s_blocks_count, nblocks);
// reserve blocks for superuser
- STORE_LE(sb->s_r_blocks_count, (uint32_t)((uint64_t) nblocks_full * nreserved / 100));
+ STORE_LE(sb->s_r_blocks_count, nreserved);
// ninodes
STORE_LE(sb->s_inodes_per_group, inodes_per_group);
STORE_LE(sb->s_inodes_count, inodes_per_group * ngroups);
STORE_LE(sb->s_mkfs_time, timestamp);
STORE_LE(sb->s_wtime, timestamp);
STORE_LE(sb->s_lastcheck, timestamp);
- // misc
+ // misc. Values are chosen to match mke2fs 1.41.9
STORE_LE(sb->s_state, 1); // TODO: what's 1?
STORE_LE(sb->s_creator_os, EXT2_OS_LINUX);
STORE_LE(sb->s_checkinterval, 24*60*60 * 180); // 180 days
STORE_LE(sb->s_errors, EXT2_ERRORS_DEFAULT);
+ // mke2fs 1.41.9 also sets EXT3_FEATURE_COMPAT_RESIZE_INODE
+ // and if >= 0.5GB, EXT3_FEATURE_RO_COMPAT_LARGE_FILE.
+ // we use values which match "mke2fs -O ^resize_inode":
+ // in this case 1.41.9 never sets EXT3_FEATURE_RO_COMPAT_LARGE_FILE.
STORE_LE(sb->s_feature_compat, EXT2_FEATURE_COMPAT_SUPP
| (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
| (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
);
- // e2fsprogs-1.41.9 doesn't like EXT2_FEATURE_INCOMPAT_WHITEOUT
- STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);// | EXT2_FEATURE_INCOMPAT_WHITEOUT;
+ STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);
STORE_LE(sb->s_feature_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
- STORE_LE(sb->s_flags, EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX);
+ STORE_LE(sb->s_flags, EXT2_FLAGS_UNSIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX);
generate_uuid(sb->s_uuid);
if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
STORE_LE(sb->s_def_hash_version, EXT2_HASH_HALF_MD4);
* don't check all the filesystems at the same time. We use a
* kludgy hack of using the UUID to derive a random jitter value.
*/
- STORE_LE(sb->s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT
+ STORE_LE(sb->s_max_mnt_count,
+ EXT2_DFL_MAX_MNT_COUNT
+ (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
- // write the label, if any
- if (label) //opts & OPT_L)
- safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
+ // write the label
+ safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
- // fill group descriptors
- gd = xzalloc(gdtsz * blocksize);
+ // calculate filesystem skeleton structures
+ gd = xzalloc(group_desc_blocks * blocksize);
buf = xmalloc(blocksize);
sb->s_free_blocks_count = 0;
- for (i = 0, pos = first_data_block, n = nblocks - first_data_block;
+ for (i = 0, pos = first_block, n = nblocks - first_block;
i < ngroups;
i++, pos += blocks_per_group, n -= blocks_per_group
) {
- uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + gdtsz) : 0);
- uint32_t fb;
+ uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + group_desc_blocks) : 0);
+ uint32_t free_blocks;
+ // fill group descriptors
STORE_LE(gd[i].bg_block_bitmap, overhead + 0);
STORE_LE(gd[i].bg_inode_bitmap, overhead + 1);
STORE_LE(gd[i].bg_inode_table, overhead + 2);
- overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
+ overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + inode_table_blocks;
gd[i].bg_free_inodes_count = inodes_per_group;
//STORE_LE(gd[i].bg_used_dirs_count, 0);
- // N.B. both root and lost+found dirs are within the first block group, thus +2
+ // N.B. both "/" and "/lost+found" are within the first block group
+ // "/" occupies 1 block, "/lost+found" occupies lost_and_found_blocks...
if (0 == i) {
- overhead += 2;
+ // ... thus increased overhead for the first block group ...
+ overhead += 1 + lost_and_found_blocks;
+ // ... and 2 used directories
STORE_LE(gd[i].bg_used_dirs_count, 2);
+ // well known reserved inodes belong to the first block too
gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
}
-// // N.B. the following is pure heuristics!
-// // Likely to cope with 1024-byte blocks, when first block is for boot sectors
-// if (ngroups-1 == i) {
-// n -= first_data_block;
-// }
+
+ // cache free block count of the group
+ free_blocks = (n < blocks_per_group ? n : blocks_per_group) - overhead;
// mark preallocated blocks as allocated
- fb = (n < blocks_per_group ? n : blocks_per_group) - overhead;
-//bb_info_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (fb + overhead));
+//bb_info_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (free_blocks + overhead));
allocate(buf, blocksize,
+ // reserve "overhead" blocks
overhead,
- blocks_per_group - (fb + overhead)
+ // mark unused trailing blocks
+ blocks_per_group - (free_blocks + overhead)
);
// dump block bitmap
PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
- STORE_LE(gd[i].bg_free_blocks_count, fb);
+ STORE_LE(gd[i].bg_free_blocks_count, free_blocks);
// mark preallocated inodes as allocated
allocate(buf, blocksize,
+ // mark reserved inodes
inodes_per_group - gd[i].bg_free_inodes_count,
+ // mark unused trailing inodes
blocks_per_group - inodes_per_group
);
// dump inode bitmap
STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);
// count overall free blocks
- sb->s_free_blocks_count += fb;
+ sb->s_free_blocks_count += free_blocks;
}
STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
// dump filesystem skeleton structures
// printf("Writing superblocks and filesystem accounting information: ");
- for (i = 0, pos = first_data_block; i < ngroups; i++, pos += blocks_per_group) {
+ for (i = 0, pos = first_block; i < ngroups; i++, pos += blocks_per_group) {
// dump superblock and group descriptors and their backups
if (has_super(i)) {
// N.B. 1024 byte blocks are special
- PUT(((uint64_t)pos << blocksize_log2) + ((0 == i && 0 == first_data_block) ? 1024 : 0), sb, 1024);//blocksize);
- PUT(((uint64_t)pos << blocksize_log2) + blocksize, gd, gdtsz * blocksize);
+ PUT(((uint64_t)pos * blocksize) + ((0 == i && 1024 != blocksize) ? 1024 : 0),
+ sb, 1024);
+ PUT(((uint64_t)pos * blocksize) + blocksize,
+ gd, group_desc_blocks * blocksize);
}
}
PUT(0, buf, 1024); // N.B. 1024 <= blocksize, so buf[0..1023] contains zeros
// zero inode tables
for (i = 0; i < ngroups; ++i)
- for (n = 0; n < itsz; ++n)
- PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize, buf, blocksize);
+ for (n = 0; n < inode_table_blocks; ++n)
+ PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize,
+ buf, blocksize);
// prepare directory inode
inode = (struct ext2_inode *)buf;
STORE_LE(inode->i_atime, timestamp);
STORE_LE(inode->i_ctime, timestamp);
STORE_LE(inode->i_size, blocksize);
- // N.B. inode->i_blocks stores the number of 512 byte data blocks. Why on Earth?!
+ // inode->i_blocks stores the number of 512 byte data blocks
+ // (512, because it goes directly to struct stat without scaling)
STORE_LE(inode->i_blocks, blocksize / 512);
// dump root dir inode
STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
- STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + itsz);
- PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) << blocksize_log2) + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode));
+ STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks);
+ PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * inodesize,
+ buf, inodesize);
// dump lost+found dir inode
STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
- STORE_LE(inode->i_block[0], inode->i_block[0]+1); // use next block
- PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) << blocksize_log2) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
+ STORE_LE(inode->i_size, lost_and_found_blocks * blocksize);
+ STORE_LE(inode->i_blocks, (lost_and_found_blocks * blocksize) / 512);
+ n = FETCH_LE32(inode->i_block[0]) + 1;
+ for (i = 0; i < lost_and_found_blocks; ++i)
+ STORE_LE(inode->i_block[i], i + n); // use next block
+//bb_info_msg("LAST BLOCK USED[%u]", i + n);
+ PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * inodesize,
+ buf, inodesize);
// dump directories
memset(buf, 0, blocksize);
dir = (struct ext2_dir *)buf;
- // dump lost+found dir block
+ // dump 2nd+ blocks of "/lost+found"
+ STORE_LE(dir->rec_len1, blocksize); // e2fsck 1.41.4 compat (1.41.9 does not need this)
+ for (i = 1; i < lost_and_found_blocks; ++i)
+ PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1+i) * blocksize,
+ buf, blocksize);
+
+ // dump 1st block of "/lost+found"
STORE_LE(dir->inode1, EXT2_GOOD_OLD_FIRST_INO);
STORE_LE(dir->rec_len1, 12);
STORE_LE(dir->name_len1, 1);
STORE_LE(dir->name_len2, 2);
STORE_LE(dir->file_type2, EXT2_FT_DIR);
dir->name2[0] = '.'; dir->name2[1] = '.';
- PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + itsz + 1) * blocksize, buf, blocksize);
+ PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 1) * blocksize, buf, blocksize);
// dump root dir block
STORE_LE(dir->inode1, EXT2_ROOT_INO);
STORE_LE(dir->name_len3, 10);
STORE_LE(dir->file_type3, EXT2_FT_DIR);
strcpy(dir->name3, "lost+found");
- PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + itsz + 0) * blocksize, buf, blocksize);
+ PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + inode_table_blocks + 0) * blocksize, buf, blocksize);
- done:
// cleanup
if (ENABLE_FEATURE_CLEAN_UP) {
free(buf);
projects / oweals / busybox.git / blobdiff