*
* Busybox'ed (2009) by Vladimir Dronnikov <dronnikov@gmail.com>
*
- * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
+//config:config MKE2FS
+//config: bool "mke2fs (10 kb)"
+//config: default y
+//config: select PLATFORM_LINUX
+//config: help
+//config: Utility to create EXT2 filesystems.
+//config:
+//config:config MKFS_EXT2
+//config: bool "mkfs.ext2 (10 kb)"
+//config: default y
+//config: select PLATFORM_LINUX
+//config: help
+//config: Alias to "mke2fs".
+
+// APPLET_ODDNAME:name main location suid_type help
+//applet:IF_MKE2FS( APPLET_ODDNAME(mke2fs, mkfs_ext2, BB_DIR_SBIN, BB_SUID_DROP, mkfs_ext2))
+//applet:IF_MKFS_EXT2(APPLET_ODDNAME(mkfs.ext2, mkfs_ext2, BB_DIR_SBIN, BB_SUID_DROP, mkfs_ext2))
+////////:IF_MKFS_EXT3(APPLET_ODDNAME(mkfs.ext3, mkfs_ext2, BB_DIR_SBIN, BB_SUID_DROP, mkfs_ext2))
+
+//kbuild:lib-$(CONFIG_MKE2FS) += mkfs_ext2.o
+//kbuild:lib-$(CONFIG_MKFS_EXT2) += mkfs_ext2.o
+
+//usage:#define mkfs_ext2_trivial_usage
+//usage: "[-Fn] "
+/* //usage: "[-c|-l filename] " */
+//usage: "[-b BLK_SIZE] "
+/* //usage: "[-f fragment-size] [-g blocks-per-group] " */
+//usage: "[-i INODE_RATIO] [-I INODE_SIZE] "
+/* //usage: "[-j] [-J journal-options] [-N number-of-inodes] " */
+//usage: "[-m RESERVED_PERCENT] "
+/* //usage: "[-o creator-os] [-O feature[,...]] [-q] " */
+/* //usage: "[r fs-revision-level] [-E extended-options] [-v] [-F] " */
+//usage: "[-L LABEL] "
+/* //usage: "[-M last-mounted-directory] [-S] [-T filesystem-type] " */
+//usage: "BLOCKDEV [KBYTES]"
+//usage:#define mkfs_ext2_full_usage "\n\n"
+//usage: " -b BLK_SIZE Block size, bytes"
+/* //usage: "\n -c Check device for bad blocks" */
+/* //usage: "\n -E opts Set extended options" */
+/* //usage: "\n -f size Fragment size in bytes" */
+//usage: "\n -F Force"
+/* //usage: "\n -g N Number of blocks in a block group" */
+//usage: "\n -i RATIO Max number of files is filesystem_size / RATIO"
+//usage: "\n -I BYTES Inode size (min 128)"
+/* //usage: "\n -j Create a journal (ext3)" */
+/* //usage: "\n -J opts Set journal options (size/device)" */
+/* //usage: "\n -l file Read bad blocks list from file" */
+//usage: "\n -L LBL Volume label"
+//usage: "\n -m PERCENT Percent of blocks to reserve for admin"
+/* //usage: "\n -M dir Set last mounted directory" */
+//usage: "\n -n Dry run"
+/* //usage: "\n -N N Number of inodes to create" */
+/* //usage: "\n -o os Set the 'creator os' field" */
+/* //usage: "\n -O features Dir_index/filetype/has_journal/journal_dev/sparse_super" */
+/* //usage: "\n -q Quiet" */
+/* //usage: "\n -r rev Set filesystem revision" */
+/* //usage: "\n -S Write superblock and group descriptors only" */
+/* //usage: "\n -T fs-type Set usage type (news/largefile/largefile4)" */
+/* //usage: "\n -v Verbose" */
+
#include "libbb.h"
#include <linux/fs.h>
-#include <linux/ext2_fs.h>
-#include "volume_id/volume_id_internal.h"
-
-#define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
-#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
-
-// storage helper
-void BUG_unsupported_field_size(void);
-#define STORE_LE(field, value) \
-do { \
- if (sizeof(field) == 4) \
- field = cpu_to_le32(value); \
- else if (sizeof(field) == 2) \
- field = cpu_to_le16(value); \
- else if (sizeof(field) == 1) \
- field = (value); \
- else \
- BUG_unsupported_field_size(); \
-} while (0)
+#include "bb_e2fs_defs.h"
+
+#define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
+#define ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX 1
+
+#define EXT2_HASH_HALF_MD4 1
+#define EXT2_FLAGS_SIGNED_HASH 0x0001
+#define EXT2_FLAGS_UNSIGNED_HASH 0x0002
// All fields are little-endian
struct ext2_dir {
}
// taken from mkfs_minix.c. libbb candidate?
-static unsigned div_roundup(uint32_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
uint32_t res = size / n;
static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32_t end)
{
uint32_t i;
+
+//bb_error_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]:=[%x]", blocksize, start, end, blocksize - end/8 - 1, (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_error_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;
+ uint32_t nblocks, nblocks_full;
+ uint32_t nreserved;
uint32_t ngroups;
uint32_t bytes_per_inode;
- uint32_t first_data_block;
- uint32_t ninodes_per_group;
- uint32_t gdtsz, itsz;
+ uint32_t first_block;
+ uint32_t inodes_per_group;
+ uint32_t group_desc_blocks;
+ uint32_t inode_table_blocks;
+ uint32_t lost_and_found_blocks;
time_t timestamp;
- unsigned opts;
- const char *label;
+ const char *label = "";
struct stat st;
struct ext2_super_block *sb; // superblock
struct ext2_group_desc *gd; // group descriptors
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
+ /*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");
+ xfstat(fd, &st, argv[0]);
+ 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");
- if (nblocks < 8)
- bb_error_msg_and_die("need >= 8 blocks");
#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");
- // number of bits in one block, i.e. 8*blocksize
-#define blocks_per_group (8 * blocksize)
-
-/* e2fsprogs-1.41.9
- overhead = 2 + fs->inode_blocks_per_group;
- if (has_super(fs->group_desc_count - 1))
- overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
- rem = (nblocks - first_data_block) % blocks_per_group);
- if ((fs->group_desc_count == 1) && rem && (rem < overhead)) {
- retval = EXT2_ET_TOOSMALL;
- goto cleanup;
- }
- if (rem && (rem < overhead+50)) {
- nblocks -= rem;
- goto retry;
- }
-*/
+ // 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;
+ // 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);
+
+ 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) {
+ /*
+ * From e2fsprogs: Calculate the number of GDT blocks to reserve for online
+ * filesystem growth.
+ * The absolute maximum number of GDT blocks we can reserve is determined by
+ * the number of block pointers that can fit into a single block.
+ * We set it at 1024x the current filesystem size, or
+ * the upper block count limit (2^32), whichever is lower.
+ */
+ 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;
+ }
{
- // ninodes is the total number of inodes (files) in the file system
- uint32_t ninodes = nblocks / (bytes_per_inode >> blocksize_log2);
+ // N.B. e2fsprogs does as follows!
+ 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;
- ninodes_per_group = div_roundup(ninodes, ngroups);
+ inodes_per_group = div_roundup(ninodes, ngroups);
// minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
- if (ninodes_per_group < 16)
- ninodes_per_group = 16;
- }
-
- // TODO: 5?/5 WE MUST NOT DEPEND ON WHETHER DEVICE IS /dev/zero 'ed OR NOT
- // TODO: 3/5 refuse if mounted
- // TODO: 4/5 compat options
- // TODO: 1/5 sanity checks
- // TODO: 0/5 more verbose error messages
- // TODO: 0/5 info printing
- // TODO: 2/5 bigendianness! Spot where it comes to play! sb->, gd->
- // TODO: 2/5 reserved GDT: how to mark but not allocate?
- // TODO: 3/5 dir_index?
-
- // fill the superblock
- sb = xzalloc(blocksize);
- sb->s_rev_level = 1; // revision 1 filesystem
- sb->s_magic = EXT2_SUPER_MAGIC;
- sb->s_inode_size = sizeof(*inode);
- sb->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
- sb->s_log_block_size = 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
- sb->s_first_data_block = first_data_block; // 0 or 1
- // block and inode bitmaps occupy no more than one block, so maximum number of blocks is
- sb->s_blocks_per_group = sb->s_frags_per_group = blocks_per_group;
- timestamp = time(NULL);
- sb->s_mkfs_time = sb->s_wtime = sb->s_lastcheck = timestamp;
- sb->s_state = 1;
- sb->s_creator_os = EXT2_OS_LINUX;
- sb->s_checkinterval = 24*60*60 * 180; // 180 days
- sb->s_errors = EXT2_ERRORS_DEFAULT;
- 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
- sb->s_feature_incompat = EXT2_FEATURE_INCOMPAT_FILETYPE;// | EXT2_FEATURE_INCOMPAT_WHITEOUT;
- sb->s_feature_ro_compat = EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER;
- sb->s_flags = EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX;
- generate_uuid(sb->s_uuid);
- if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
- sb->s_def_hash_version = EXT2_HASH_HALF_MD4;
- generate_uuid((uint8_t *)sb->s_hash_seed);
- }
- /*
- * From e2fsprogs: add "jitter" to the superblock's check interval so that we
- * 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.
- */
- sb->s_max_mnt_count = EXT2_DFL_MAX_MNT_COUNT
- + (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT);
-
- sb->s_blocks_count = nblocks;
-
- // reserve blocks for superuser
- sb->s_r_blocks_count = ((uint64_t) nblocks * nreserved) / 100;
-
- gdtsz = div_roundup(ngroups, EXT2_DESC_PER_BLOCK(sb));
- /*
- * From e2fsprogs: Calculate the number of GDT blocks to reserve for online
- * filesystem growth.
- * The absolute maximum number of GDT blocks we can reserve is determined by
- * the number of block pointers that can fit into a single block.
- */
- /* We set it at 1024x the current filesystem size, or
- * the upper block count limit (2^32), whichever is lower.
- */
- if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
- 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, EXT2_DESC_PER_BLOCK(sb)) - gdtsz;
- if (rgdtsz > EXT2_ADDR_PER_BLOCK(sb))
- rgdtsz = EXT2_ADDR_PER_BLOCK(sb);
- STORE_LE(sb->s_reserved_gdt_blocks, rgdtsz);
- gdtsz += rgdtsz;
+ if (inodes_per_group < 16)
+ inodes_per_group = 16;
+ // 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 * inodesize, blocksize) * blocksize) / inodesize;
+ // make sure the number of inodes per group is a multiple of 8
+ inodes_per_group &= ~7;
+ 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_error_msg("CHOP[%u]", remainder);
+ nblocks -= remainder;
+ goto retry;
+ }
}
- // N.B. a block group can have no more than 8*blocksize inodes
- if (ninodes_per_group > blocks_per_group)
- ninodes_per_group = blocks_per_group;
- // adjust inodes per group so they completely fill the inode table blocks in the descriptor
- ninodes_per_group = (div_roundup(ninodes_per_group * EXT2_INODE_SIZE(sb), blocksize) << blocksize_log2) / EXT2_INODE_SIZE(sb);
- // make sure the number of inodes per group is a multiple of 8
- ninodes_per_group &= ~7;
- sb->s_inodes_per_group = ninodes_per_group;// = div_roundup(ninodes_per_group * sb->s_inode_size, blocksize);
- // total ninodes
- sb->s_inodes_count = ninodes_per_group * ngroups;
-
- itsz = ninodes_per_group * sb->s_inode_size / blocksize;
- sb->s_free_inodes_count = sb->s_inodes_count - EXT2_GOOD_OLD_FIRST_INO;
-
- // write the label, if any
- if (opts & OPT_L)
- safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
-
-#if 1
-/* if (fs_param.s_blocks_count != s->s_blocks_count)
- fprintf(stderr, _("warning: %u blocks unused.\n\n"),
- fs_param.s_blocks_count - s->s_blocks_count);
-*/
-
+ if (nblocks_full - nblocks)
+ printf("warning: %u blocks unused\n\n", nblocks_full - nblocks);
printf(
"Filesystem label=%s\n"
"OS type: Linux\n"
"%u block groups\n"
"%u blocks per group, %u fragments per group\n"
"%u inodes per group"
- , (char *)sb->s_volume_name
- , blocksize, sb->s_log_block_size
- , blocksize, sb->s_log_block_size
- , sb->s_inodes_count, sb->s_blocks_count
- , sb->s_r_blocks_count, nreserved
- , first_data_block
- , gdtsz * EXT2_DESC_PER_BLOCK(sb) * blocks_per_group
+ , label
+ , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
+ , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
+ , inodes_per_group * ngroups, nblocks
+ , nreserved, reserved_percent
+ , first_block
+ , group_desc_blocks * (blocksize / (unsigned)sizeof(*gd)) * blocks_per_group
, ngroups
, blocks_per_group, blocks_per_group
- , ninodes_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');
-#endif
- 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: 1/5 sanity checks
+ // TODO: 0/5 more verbose error messages
+ // TODO: 4/5 bigendianness: recheck, wait for ARM reporters
+ // TODO: 2/5 reserved GDT: how to mark but not allocate?
+ // TODO: 3/5 dir_index?
+
+ // fill the superblock
+ 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, inodesize);
+ // set "Required extra isize" and "Desired extra isize" fields to 28
+ if (inodesize != sizeof(*inode)) {
+ STORE_LE(sb->s_min_extra_isize, 0x001c);
+ STORE_LE(sb->s_want_extra_isize, 0x001c);
+ }
+ 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 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, 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_free_inodes_count, inodes_per_group * ngroups - EXT2_GOOD_OLD_FIRST_INO);
+ // timestamps
+ timestamp = time(NULL);
+ STORE_LE(sb->s_mkfs_time, timestamp);
+ STORE_LE(sb->s_wtime, timestamp);
+ STORE_LE(sb->s_lastcheck, timestamp);
+ // 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)
+ );
+ 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_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);
+ generate_uuid((uint8_t *)sb->s_hash_seed);
+ }
+ /*
+ * From e2fsprogs: add "jitter" to the superblock's check interval so that we
+ * 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
+ + (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
+
+ // 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;
+ 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);
- gd[i].bg_block_bitmap = overhead + 0;
- gd[i].bg_inode_bitmap = overhead + 1;
- gd[i].bg_inode_table = overhead + 2;
- overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
- gd[i].bg_free_inodes_count = ninodes_per_group;
- //gd[i].bg_used_dirs_count = 0;
- // N.B. both root and lost+found dirs are within the first block group, thus +2
+ 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*/ + inode_table_blocks;
+ gd[i].bg_free_inodes_count = inodes_per_group;
+ //STORE_LE(gd[i].bg_used_dirs_count, 0);
+ // 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;
- gd[i].bg_used_dirs_count = 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) {
- overhead += first_data_block;
- }
- gd[i].bg_free_blocks_count = (n < blocks_per_group ? n : blocks_per_group) - overhead;
- sb->s_free_blocks_count += gd[i].bg_free_blocks_count;
- }
- STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
-
- // dump filesystem skeleton structures
-// printf("Writing superblocks and filesystem accounting information: ");
- buf = xmalloc(blocksize);
- for (i = 0, pos = first_data_block; i < ngroups; i++, pos += blocks_per_group) {
- uint32_t overhead = has_super(i) ? (1/*sb*/ + gdtsz) : 0;
- uint32_t start;
- uint32_t end;
- // dump superblock and group descriptors and their backups
- if (overhead) { // N.B. in fact, we want (has_super(i)) condition, but it is equal to (overhead != 0) and is cheaper
- // 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);
- }
-
- start = overhead + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
- if (i == 0)
- start += 2; // for "/" and "/lost+found"
- end = blocks_per_group - (start + gd[i].bg_free_blocks_count);
+ // cache free block count of the group
+ free_blocks = (n < blocks_per_group ? n : blocks_per_group) - overhead;
// mark preallocated blocks as allocated
- allocate(buf, blocksize, start, end);
+//bb_error_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (free_blocks + overhead));
+ allocate(buf, blocksize,
+ // reserve "overhead" blocks
+ overhead,
+ // mark unused trailing blocks
+ blocks_per_group - (free_blocks + overhead)
+ );
// dump block bitmap
- PUT((uint64_t)(pos + overhead) * blocksize, buf, blocksize);
+ PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
+ STORE_LE(gd[i].bg_free_blocks_count, free_blocks);
// mark preallocated inodes as allocated
allocate(buf, blocksize,
- ninodes_per_group - gd[i].bg_free_inodes_count,
- blocks_per_group - ninodes_per_group
+ // 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
- //PUT((uint64_t)(pos + overhead + 1) * blocksize, buf, blocksize);
+ //PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
//but it's right after block bitmap, so we can just:
xwrite(fd, buf, blocksize);
+ STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);
+
+ // count overall free blocks
+ 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_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) + ((0 == i && 1024 != blocksize) ? 1024 : 0),
+ sb, 1024);
+ PUT(((uint64_t)pos * blocksize) + blocksize,
+ gd, group_desc_blocks * blocksize);
+ }
}
// zero boot sectors
memset(buf, 0, blocksize);
- PUT(0, buf, 1024); // N.B. 1024 <= blocksize
+ // Disabled: standard mke2fs doesn't do this, and
+ // on SPARC this destroys Sun disklabel.
+ // Users who need/want zeroing can easily do it with dd.
+ //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)(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], gd[0].bg_inode_table + itsz);
- PUT(((uint64_t)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 //= gd[0].bg_inode_table + itsz + 1;
- PUT(((uint64_t)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_error_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)(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)(gd[0].bg_inode_table + itsz + 0) * blocksize, buf, blocksize);
-
-// bb_info_msg("done\n"
-// "This filesystem will be automatically checked every %u mounts or\n"
-// "180 days, whichever comes first. Use tune2fs -c or -i to override.",
-// sb->s_max_mnt_count
-// );
+ 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