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mkfs_ext2: new applet by Vladimir
function old new delta mkfs_ext2_main - 2011 +2011 static.supers - 184 +184 allocate - 118 +118 packed_usage 26692 26791 +99 PUT - 52 +52 has_super - 28 +28 applet_names 2143 2160 +17 applet_main 1264 1272 +8 applet_nameofs 632 636 +4 applet_install_loc 158 159 +1 ------------------------------------------------------------------------------ (add/remove: 5/0 grow/shrink: 5/0 up/down: 2522/0) Total: 2522 bytes Signed-off-by: Vladimir Dronnikov <dronnikov@gmail.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Vladimir Dronnikov
Denys Vlasenko
parent
8dbe9bba8e
commit
823b4e6f26
@ -258,9 +258,9 @@ IF_MESG(APPLET(mesg, _BB_DIR_USR_BIN, _BB_SUID_DROP))
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IF_MICROCOM(APPLET(microcom, _BB_DIR_USR_BIN, _BB_SUID_DROP))
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IF_MKDIR(APPLET_NOFORK(mkdir, mkdir, _BB_DIR_BIN, _BB_SUID_DROP, mkdir))
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IF_MKFS_VFAT(APPLET_ODDNAME(mkdosfs, mkfs_vfat, _BB_DIR_SBIN, _BB_SUID_DROP, mkfs_vfat))
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//IF_MKE2FS(APPLET(mke2fs, _BB_DIR_SBIN, _BB_SUID_DROP))
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IF_MKFS_EXT2(APPLET_ODDNAME(mke2fs, mkfs_ext2, _BB_DIR_SBIN, _BB_SUID_DROP, mkfs_ext2))
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IF_MKFIFO(APPLET(mkfifo, _BB_DIR_USR_BIN, _BB_SUID_DROP))
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//IF_MKE2FS(APPLET_ODDNAME(mkfs.ext2, mke2fs, _BB_DIR_SBIN, _BB_SUID_DROP, mkfs_ext2))
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IF_MKFS_EXT2(APPLET_ODDNAME(mkfs.ext2, mkfs_ext2, _BB_DIR_SBIN, _BB_SUID_DROP, mkfs_ext2))
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//IF_MKE2FS(APPLET_ODDNAME(mkfs.ext3, mke2fs, _BB_DIR_SBIN, _BB_SUID_DROP, mkfs_ext3))
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IF_MKFS_MINIX(APPLET_ODDNAME(mkfs.minix, mkfs_minix, _BB_DIR_SBIN, _BB_SUID_DROP, mkfs_minix))
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IF_MKFS_VFAT(APPLET_ODDNAME(mkfs.vfat, mkfs_vfat, _BB_DIR_SBIN, _BB_SUID_DROP, mkfs_vfat))
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@ -2702,37 +2702,6 @@
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"/tmp/foo/bar/baz: No such file or directory\n" \
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"$ mkdir -p /tmp/foo/bar/baz\n"
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#define mke2fs_trivial_usage \
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"[-c|-l filename] [-b block-size] [-f fragment-size] [-g blocks-per-group] " \
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"[-i bytes-per-inode] [-j] [-J journal-options] [-N number-of-inodes] [-n] " \
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"[-m reserved-blocks-percentage] [-o creator-os] [-O feature[,...]] [-q] " \
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"[r fs-revision-level] [-E extended-options] [-v] [-F] [-L volume-label] " \
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"[-M last-mounted-directory] [-S] [-T filesystem-type] " \
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"device [blocks-count]"
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#define mke2fs_full_usage "\n\n" \
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" -b size Block size in bytes" \
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"\n -c Check for bad blocks before creating" \
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"\n -E opts Set extended options" \
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"\n -f size Fragment size in bytes" \
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"\n -F Force (ignore sanity checks)" \
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"\n -g num Number of blocks in a block group" \
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"\n -i ratio The bytes/inode ratio" \
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"\n -j Create a journal (ext3)" \
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"\n -J opts Set journal options (size/device)" \
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"\n -l file Read bad blocks list from file" \
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"\n -L lbl Set the volume label" \
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"\n -m percent Percent of fs blocks to reserve for admin" \
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"\n -M dir Set last mounted directory" \
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"\n -n Don't actually create anything" \
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"\n -N num Number of inodes to create" \
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"\n -o os Set the 'creator os' field" \
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"\n -O features Dir_index/filetype/has_journal/journal_dev/sparse_super" \
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"\n -q Quiet" \
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"\n -r rev Set filesystem revision" \
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"\n -S Write superblock and group descriptors only" \
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"\n -T fs-type Set usage type (news/largefile/largefile4)" \
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"\n -v Verbose" \
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#define mkfifo_trivial_usage \
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"[OPTIONS] name"
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#define mkfifo_full_usage "\n\n" \
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@ -2743,6 +2712,42 @@
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"\n -Z Set security context" \
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)
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#define mkfs_ext2_trivial_usage \
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/* "[-c|-l filename] " */ \
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"[-b BLK_SIZE] " \
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/* "[-f fragment-size] [-g blocks-per-group] " */ \
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"[-i BYTES_PER_INODE] " \
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/* "[-j] [-J journal-options] [-N number-of-inodes] [-n] " */ \
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"[-m RESERVED_PERCENT] " \
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/* "[-o creator-os] [-O feature[,...]] [-q] " */ \
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/* "[r fs-revision-level] [-E extended-options] [-v] [-F] " */ \
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"[-L LABEL] " \
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/* "[-M last-mounted-directory] [-S] [-T filesystem-type] " */ \
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"DEVICE [BLK_COUNT]"
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#define mkfs_ext2_full_usage "\n" \
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"\n -b BLK_SIZE Block size in bytes" \
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/* "\n -c Check for bad blocks before creating" */ \
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/* "\n -E opts Set extended options" */ \
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/* "\n -f size Fragment size in bytes" */ \
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/* "\n -F Force (ignore sanity checks)" */ \
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/* "\n -g num Number of blocks in a block group" */ \
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"\n -i BYTES The bytes/inode ratio" \
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/* "\n -j Create a journal (ext3)" */ \
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/* "\n -J opts Set journal options (size/device)" */ \
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/* "\n -l file Read bad blocks list from file" */ \
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"\n -L LABEL Set the volume label" \
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"\n -m PERCENT Percent of blocks to reserve for admin" \
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/* "\n -M dir Set last mounted directory" */ \
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/* "\n -n Don't actually create anything" */ \
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/* "\n -N num Number of inodes to create" */ \
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/* "\n -o os Set the 'creator os' field" */ \
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/* "\n -O features Dir_index/filetype/has_journal/journal_dev/sparse_super" */ \
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/* "\n -q Quiet" */ \
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/* "\n -r rev Set filesystem revision" */ \
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/* "\n -S Write superblock and group descriptors only" */ \
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/* "\n -T fs-type Set usage type (news/largefile/largefile4)" */ \
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/* "\n -v Verbose" */ \
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#define mkfs_minix_trivial_usage \
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"[-c | -l filename] [-nXX] [-iXX] /dev/name [blocks]"
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#define mkfs_minix_full_usage "\n\n" \
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@ -239,6 +239,12 @@ config MKFS_VFAT
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help
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Utility to create FAT32 filesystems.
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config MKFS_EXT2
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bool "mkfs_ext2"
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default n
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help
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Utility to create EXT2 filesystems.
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config GETOPT
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bool "getopt"
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default n
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@ -22,6 +22,7 @@ lib-$(CONFIG_IPCRM) += ipcrm.o
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lib-$(CONFIG_IPCS) += ipcs.o
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lib-$(CONFIG_LOSETUP) += losetup.o
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lib-$(CONFIG_MDEV) += mdev.o
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lib-$(CONFIG_MKFS_EXT2) += mkfs_ext2.o
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lib-$(CONFIG_MKFS_MINIX) += mkfs_minix.o
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lib-$(CONFIG_MKFS_VFAT) += mkfs_vfat.o
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lib-$(CONFIG_MKSWAP) += mkswap.o
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479
util-linux/mkfs_ext2.c
Normal file
479
util-linux/mkfs_ext2.c
Normal file
@ -0,0 +1,479 @@
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/* vi: set sw=4 ts=4: */
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/*
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* mkfs_ext2: utility to create EXT2 filesystem
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* inspired by genext2fs
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*
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* Busybox'ed (2009) by Vladimir Dronnikov <dronnikov@gmail.com>
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*
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* Licensed under GPLv2, see file LICENSE in this tarball for details.
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*/
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#include "libbb.h"
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#include <linux/fs.h>
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#include <linux/ext2_fs.h>
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#include "volume_id/volume_id_internal.h"
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#define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
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#define ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX 1
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// from e2fsprogs
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#define s_reserved_gdt_blocks s_padding1
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#define s_mkfs_time s_reserved[0]
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#define s_flags s_reserved[22]
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#define EXT2_HASH_HALF_MD4 1
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#define EXT2_FLAGS_SIGNED_HASH 0x0001
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// whiteout: for writable overlays
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//#define LINUX_S_IFWHT 0160000
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//#define EXT2_FEATURE_INCOMPAT_WHITEOUT 0x0020
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// storage helper
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void BUG_unsupported_field_size(void);
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#define STORE_LE(field, value) \
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do { \
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if (sizeof(field) == 4) \
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field = cpu_to_le32(value); \
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else if (sizeof(field) == 2) \
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field = cpu_to_le16(value); \
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else if (sizeof(field) == 1) \
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field = (value); \
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else \
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BUG_unsupported_field_size(); \
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} while (0)
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// All fields are little-endian
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struct ext2_dir {
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uint32_t inode1;
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uint16_t rec_len1;
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uint8_t name_len1;
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uint8_t file_type1;
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char name1[4];
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uint32_t inode2;
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uint16_t rec_len2;
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uint8_t name_len2;
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uint8_t file_type2;
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char name2[4];
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uint32_t inode3;
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uint16_t rec_len3;
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uint8_t name_len3;
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uint8_t file_type3;
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char name3[12];
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};
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static inline int int_log2(int arg)
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{
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int r = 0;
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while ((arg >>= 1) != 0)
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r++;
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return r;
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}
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// taken from mkfs_minix.c. libbb candidate?
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static ALWAYS_INLINE unsigned div_roundup(uint32_t size, uint32_t n)
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{
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return (size + n-1) / n;
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}
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static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32_t end)
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{
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uint32_t i;
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memset(bitmap, 0, blocksize);
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i = start/8;
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memset(bitmap, 0xFF, i);
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bitmap[i] = 0xFF >> (8-(start&7));
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//bb_info_msg("ALLOC: [%u][%u][%u]: [%u]:=[%x]", blocksize, start, end, blocksize - end/8 - 1, (uint8_t)(0xFF << (8-(end&7))));
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i = end/8;
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bitmap[blocksize - i - 1] = 0xFF << (8-(end&7));
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memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
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}
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#if 0
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// TODO: get rid of FPU
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static bool is_power_of(uint32_t x, uint16_t n)
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{
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// return (!(x % n) && is_power_of(x / n, n));
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double z = logf(x)/logf(n);
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return (z == (int)z);
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}
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static bool has_super(uint32_t x)
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{
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return (0 == x || 1 == x || is_power_of(x, 3) || is_power_of(x, 5) || is_power_of(x, 7));
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}
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#else
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static bool has_super(uint32_t x)
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{
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static const uint32_t supers[] = {
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0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729,
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2187, 2401, 3125, 6561, 15625, 16807, 19683, 59049, 78125,
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117649, 177147, 390625, 531441, 823543, 1594323, 1953125,
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4782969, 5764801, 9765625, 14348907, 40353607, 43046721,
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48828125, 129140163, 244140625, 282475249, 387420489,
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1162261467, 1220703125, 1977326743, 3486784401/* >2^31 */,
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};
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for (int i = sizeof(supers)/sizeof(supers[0]); --i >= 0; )
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if (x == supers[i])
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return 1;
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return 0;
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}
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#endif
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/* Standard mke2fs 1.41.9:
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* Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size]
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* [-i bytes-per-inode] [-I inode-size] [-J journal-options]
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* [-G meta group size] [-N number-of-inodes]
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* [-m reserved-blocks-percentage] [-o creator-os]
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* [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
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* [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
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* [-T fs-type] [-U UUID] [-jnqvFSV] device [blocks-count]
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*/
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// N.B. not commented below options are taken and silently ignored
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enum {
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OPT_c = 1 << 0,
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OPT_l = 1 << 1,
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OPT_b = 1 << 2, // block size, in bytes
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OPT_f = 1 << 3,
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OPT_i = 1 << 4, // bytes per inode
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OPT_I = 1 << 5,
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OPT_J = 1 << 6,
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OPT_G = 1 << 7,
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OPT_N = 1 << 8,
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OPT_m = 1 << 9, // percentage of blocks reserved for superuser
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OPT_o = 1 << 10,
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OPT_g = 1 << 11,
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OPT_L = 1 << 12, // label
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OPT_M = 1 << 13,
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OPT_O = 1 << 14,
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OPT_r = 1 << 15,
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OPT_E = 1 << 16,
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OPT_T = 1 << 17,
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OPT_U = 1 << 18,
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OPT_j = 1 << 19,
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OPT_n = 1 << 20,
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OPT_q = 1 << 21,
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OPT_v = 1 << 22,
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OPT_F = 1 << 23,
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OPT_S = 1 << 24,
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//OPT_V = 1 << 25, // -V version. bbox applets don't support that
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};
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#define fd 3 /* predefined output descriptor */
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static void PUT(uint64_t off, void *buf, uint32_t size)
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{
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if (!(option_mask32 & OPT_n)) {
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xlseek(fd, off, SEEK_SET);
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xwrite(fd, buf, size);
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}
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}
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int mkfs_ext2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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{
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unsigned i, pos, n;
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unsigned bs, blocksize;
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unsigned nreserved = 5;
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uint32_t nblocks;
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uint32_t ngroups;
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unsigned bytes_per_inode;
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uint32_t nblocks_per_group;
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uint32_t first_data_block;
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uint32_t ninodes;
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uint32_t ninodes_per_group;
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uint32_t gdtsz, rgdtsz, itsz;
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time_t timestamp;
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unsigned opts;
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const char *label;
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struct stat st;
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struct ext2_super_block *sb; // superblock
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struct ext2_group_desc *gd; // group descriptors
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struct ext2_inode *inode;
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struct ext2_dir *dir;
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uint8_t *buf;
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bs = EXT2_MIN_BLOCK_SIZE;
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opt_complementary = "-1:b+:m+:i+";
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opts = getopt32(argv, "cl:b:f:i:I:J:G:N:m:o:g:L:M:O:r:E:T:U:jnqvFS",
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NULL, &bs, NULL, &bytes_per_inode, NULL, NULL, NULL, NULL,
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&nreserved, NULL, NULL, &label, NULL, NULL, NULL, NULL, NULL, NULL);
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argv += optind; // argv[0] -- device
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// block size minimax, block size is a multiple of minimum
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blocksize = bs;
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if (blocksize < EXT2_MIN_BLOCK_SIZE
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|| blocksize > EXT2_MAX_BLOCK_SIZE
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|| (blocksize & (blocksize - 1)) // not power of 2
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) {
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bb_error_msg_and_die("-%c is bad", 'b');
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}
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// reserved blocks count
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if (nreserved > 50)
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bb_error_msg_and_die("-%c is bad", 'm');
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// check the device is a block device
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xstat(argv[0], &st);
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if (!S_ISBLK(st.st_mode) && !(opts & OPT_F))
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bb_error_msg_and_die("not a block device");
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// check if it is mounted
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// N.B. what if we format a file? find_mount_point will return false negative since
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// it is loop block device which mounted!
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if (find_mount_point(argv[0], 0))
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bb_error_msg_and_die("can't format mounted filesystem");
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// TODO: 5?/5 WE MUST NOT DEPEND ON WHETHER DEVICE IS /dev/zero 'ed OR NOT
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// TODO: 3/5 refuse if mounted
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// TODO: 4/5 compat options
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// TODO: 1/5 sanity checks
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// TODO: 0/5 more verbose error messages
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// TODO: 0/5 info printing
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// TODO: 2/5 bigendianness! Spot where it comes to play! sb->, gd->
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// TODO: 2/5 reserved GDT: how to mark but not allocate?
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// TODO: 0/5 dir_index?
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// fill the superblock
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sb = xzalloc(blocksize);
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sb->s_rev_level = 1; // revision 1 filesystem
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sb->s_magic = EXT2_SUPER_MAGIC;
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sb->s_inode_size = sizeof(*inode);
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sb->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
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sb->s_log_block_size = sb->s_log_frag_size = int_log2(blocksize >> EXT2_MIN_BLOCK_LOG_SIZE);
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// first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then
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// the first block available for data is 1, otherwise 0
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first_data_block = sb->s_first_data_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
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// block and inode bitmaps occupy no more than one block, so maximum number of blocks is
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// number of bits in one block, i.e. 8*blocksize
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nblocks_per_group = sb->s_blocks_per_group = sb->s_frags_per_group = sb->s_inodes_per_group = 8*blocksize;
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timestamp = time(NULL);
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sb->s_mkfs_time = sb->s_wtime = sb->s_lastcheck = timestamp;
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sb->s_state = 1;
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sb->s_creator_os = EXT2_OS_LINUX;
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sb->s_max_mnt_count = EXT2_DFL_MAX_MNT_COUNT;
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sb->s_checkinterval = 24*60*60 * 180; // 180 days
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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);
|
||||
#endif
|
||||
/*
|
||||
* 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.
|
||||
*/
|
||||
for (i = 0, n = 0; i < sizeof(sb->s_uuid); i++)
|
||||
n += sb->s_uuid[i];
|
||||
sb->s_max_mnt_count += n % EXT2_DFL_MAX_MNT_COUNT;
|
||||
|
||||
// open the device, get number of blocks
|
||||
xmove_fd(xopen3(argv[0], O_WRONLY | O_CREAT, 0666), fd);
|
||||
if (argv[1]) {
|
||||
nblocks = xatou(argv[1]);
|
||||
} else {
|
||||
nblocks = ((uoff_t)xlseek(fd, 0, SEEK_END)) / blocksize;
|
||||
xlseek(fd, 0, SEEK_SET);
|
||||
}
|
||||
sb->s_blocks_count = nblocks;
|
||||
|
||||
// nblocks is the total number of blocks in the filesystem
|
||||
if (nblocks < 8)
|
||||
bb_error_msg_and_die("nblocks");
|
||||
// reserve blocks for superuser
|
||||
sb->s_r_blocks_count = ((uint64_t) nblocks * nreserved) / 100;
|
||||
|
||||
// N.B. a block group can have no more than nblocks_per_group blocks
|
||||
ngroups = div_roundup(nblocks - first_data_block, nblocks_per_group);
|
||||
if (0 == ngroups)
|
||||
bb_error_msg_and_die("ngroups");
|
||||
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
|
||||
rgdtsz = 0xFFFFFFFF; // maximum block number
|
||||
if (nblocks < rgdtsz / 1024)
|
||||
rgdtsz = nblocks * 1024;
|
||||
rgdtsz = div_roundup(rgdtsz - first_data_block, nblocks_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);
|
||||
sb->s_reserved_gdt_blocks = rgdtsz;
|
||||
//bb_info_msg("RSRVD[%u]", n);
|
||||
#else
|
||||
rgdtsz = 0;
|
||||
#endif
|
||||
|
||||
// ninodes is the total number of inodes (files) in the file system
|
||||
if (!(opts & OPT_i)) {
|
||||
bytes_per_inode = 16384;
|
||||
if (nblocks < 512*1024)
|
||||
bytes_per_inode = 4096;
|
||||
if (nblocks < 3*1024)
|
||||
bytes_per_inode = 8192;
|
||||
}
|
||||
ninodes = nblocks / (bytes_per_inode / blocksize);
|
||||
if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
|
||||
ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
|
||||
ninodes_per_group = div_roundup(ninodes, ngroups);
|
||||
if (ninodes_per_group < 16)
|
||||
ninodes_per_group = 16; // minimum number because the first 10 are reserved
|
||||
// N.B. a block group can have no more than 8*blocksize = sb->s_inodes_per_group inodes
|
||||
if (ninodes_per_group > sb->s_inodes_per_group)
|
||||
ninodes_per_group = sb->s_inodes_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) / 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
|
||||
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));
|
||||
|
||||
// fill group descriptors
|
||||
gd = xzalloc((gdtsz + rgdtsz) * blocksize);
|
||||
sb->s_free_blocks_count = 0;
|
||||
for (i = 0, pos = first_data_block, n = nblocks;
|
||||
i < ngroups;
|
||||
i++, pos += nblocks_per_group, n -= nblocks_per_group
|
||||
) {
|
||||
uint32_t overhead = pos + has_super(i) * (1/*sb*/ + gdtsz + rgdtsz);
|
||||
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;
|
||||
// N.B. both root and lost+found dirs are within the first block group, thus +2
|
||||
//gd[i].bg_used_dirs_count = 0;
|
||||
if (0 == i) {
|
||||
overhead += 2;
|
||||
gd[i].bg_used_dirs_count = 2;
|
||||
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 < nblocks_per_group ? n : nblocks_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
|
||||
buf = xmalloc(blocksize);
|
||||
for (i = 0, pos = first_data_block; i < ngroups; i++, pos += nblocks_per_group) {
|
||||
uint32_t overhead = has_super(i) * (1/*sb*/ + gdtsz + rgdtsz);
|
||||
uint32_t start;// = has_super(i) * (1/*sb*/ + gdtsz + rgdtsz);
|
||||
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
|
||||
//bb_info_msg("SUPER@[%d]", pos);
|
||||
// N.B. 1024 byte blocks are special
|
||||
PUT(blocksize * pos + 1024 * (0 == i && 0 == first_data_block), sb, blocksize);
|
||||
PUT(blocksize * pos + blocksize, gd, (gdtsz + rgdtsz) * blocksize);
|
||||
}
|
||||
|
||||
start = overhead + 1/*bbmp*/ + 1/*ibmp*/ + itsz + (0 == i) * 2; // +2: /, /lost+found
|
||||
end = nblocks_per_group - (start + gd[i].bg_free_blocks_count);
|
||||
// mark preallocated blocks as allocated
|
||||
allocate(buf, blocksize, start, end);
|
||||
// dump block bitmap
|
||||
PUT((pos + overhead) * blocksize, buf, blocksize);
|
||||
|
||||
// mark preallocated inodes as allocated
|
||||
allocate(buf, blocksize,
|
||||
ninodes_per_group - gd[i].bg_free_inodes_count,
|
||||
8*blocksize - ninodes_per_group
|
||||
);
|
||||
// dump inode bitmap
|
||||
PUT((pos + overhead + 1) * blocksize, buf, blocksize);
|
||||
|
||||
}
|
||||
|
||||
// zero boot sectors
|
||||
memset(buf, 0, blocksize);
|
||||
PUT(0, buf, 1024); // N.B. 1024 <= blocksize
|
||||
// zero inode tables
|
||||
for (i = 0; i < ngroups; ++i)
|
||||
for (n = 0; n < itsz; ++n)
|
||||
PUT((gd[i].bg_inode_table + n) * blocksize, buf, blocksize);
|
||||
|
||||
// prepare directory inode
|
||||
inode = (struct ext2_inode *)buf;
|
||||
STORE_LE(inode->i_mode, S_IFDIR | S_IRWXU | S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH);
|
||||
inode->i_mtime = 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?!
|
||||
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(gd[0].bg_inode_table * blocksize + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode));
|
||||
|
||||
// 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(gd[0].bg_inode_table * blocksize + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
|
||||
|
||||
// dump directories
|
||||
memset(buf, 0, blocksize);
|
||||
dir = (struct ext2_dir *)buf;
|
||||
|
||||
// dump lost+found dir block
|
||||
STORE_LE(dir->inode1, EXT2_GOOD_OLD_FIRST_INO);
|
||||
STORE_LE(dir->rec_len1, 12);
|
||||
STORE_LE(dir->name_len1, 1);
|
||||
STORE_LE(dir->file_type1, EXT2_FT_DIR);
|
||||
dir->name1[0] = '.';
|
||||
STORE_LE(dir->inode2, EXT2_ROOT_INO);
|
||||
STORE_LE(dir->rec_len2, blocksize - 12);
|
||||
STORE_LE(dir->name_len2, 2);
|
||||
STORE_LE(dir->file_type2, EXT2_FT_DIR);
|
||||
dir->name2[0] = '.'; dir->name2[1] = '.';
|
||||
PUT((gd[0].bg_inode_table + itsz + 1) * blocksize, buf, blocksize);
|
||||
|
||||
// dump root dir block
|
||||
STORE_LE(dir->inode1, EXT2_ROOT_INO);
|
||||
STORE_LE(dir->rec_len2, 12);
|
||||
STORE_LE(dir->inode3, EXT2_GOOD_OLD_FIRST_INO);
|
||||
STORE_LE(dir->rec_len3, blocksize - 12 - 12);
|
||||
STORE_LE(dir->name_len3, 10);
|
||||
STORE_LE(dir->file_type3, EXT2_FT_DIR);
|
||||
strcpy(dir->name3, "lost+found");
|
||||
PUT((gd[0].bg_inode_table + itsz + 0) * blocksize, buf, blocksize);
|
||||
|
||||
// cleanup
|
||||
if (ENABLE_FEATURE_CLEAN_UP) {
|
||||
free(buf);
|
||||
free(gd);
|
||||
free(sb);
|
||||
close(fd);
|
||||
}
|
||||
|
||||
return EXIT_SUCCESS;
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user