X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fmkfs_ext2.c;h=8b435c12041e0ff14397febb88a32df6a9217a6d;hb=f5914992f316f8a628505067e108e7ba5a9590ba;hp=e840f7810344bf0f6102f94cfe7f940329d18341;hpb=69f2e2cdeba8237d51fe63aa32efbd178ce02663;p=oweals%2Fbusybox.git diff --git a/util-linux/mkfs_ext2.c b/util-linux/mkfs_ext2.c index e840f7810..8b435c120 100644 --- a/util-linux/mkfs_ext2.c +++ b/util-linux/mkfs_ext2.c @@ -10,25 +10,19 @@ #include "libbb.h" #include #include -#include /* 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); @@ -75,8 +69,8 @@ static unsigned int_log2(unsigned arg) } // taken from mkfs_minix.c. libbb candidate? -// why "uint64_t size"? we never use it for anything >32 bits -static uint32_t 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 uint32_t res = size / n; @@ -88,13 +82,14 @@ static uint32_t div_roundup(uint64_t size, uint32_t n) 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! } @@ -119,23 +114,52 @@ static uint32_t has_super(uint32_t x) } } -/* 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. So far, we do not do this. + +// 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, @@ -158,31 +182,25 @@ enum { //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 @@ -191,20 +209,18 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) struct ext2_dir *dir; uint8_t *buf; + // using global "option_mask32" instead of local "opts": + // we are register starved here 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); + /*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, &user_inodesize, NULL, NULL, NULL, + &reserved_percent, NULL, NULL, &label, NULL, NULL, NULL, NULL, 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 xmove_fd(xopen(argv[0], O_WRONLY), fd); fstat(fd, &st); - if (!S_ISBLK(st.st_mode) && !(opts & OPT_F)) + if (!S_ISBLK(st.st_mode) && !(option_mask32 & OPT_F)) bb_error_msg_and_die("not a block device"); // check if it is mounted @@ -216,6 +232,14 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) // open the device, get size in kbytes if (argv[1]) { kilobytes = xatoull(argv[1]); + // seek past end fails on block devices but works on files + if (lseek(fd, kilobytes * 1024 - 1, SEEK_SET) != (off_t)-1) { + if (!(option_mask32 & OPT_n)) + xwrite(fd, "", 1); // file grows if needed + } + //else { + // bb_error_msg("warning, block device is smaller"); + //} } else { kilobytes = (uoff_t)xlseek(fd, 0, SEEK_END) / 1024; } @@ -225,21 +249,26 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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 @@ -247,33 +276,52 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) ) { 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) + // 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) { @@ -285,43 +333,60 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) * 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; @@ -329,7 +394,6 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) } } - // print info if (nblocks_full - nblocks) printf("warning: %u blocks unused\n\n", nblocks_full - nblocks); printf( @@ -348,10 +412,9 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) , 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 @@ -359,7 +422,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) { 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)) { @@ -370,9 +433,11 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) } 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 @@ -383,23 +448,26 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) // 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); @@ -409,19 +477,22 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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); @@ -432,55 +503,61 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) * 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 @@ -490,18 +567,20 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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); } } @@ -510,8 +589,9 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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; @@ -520,24 +600,38 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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); @@ -548,7 +642,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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); @@ -558,9 +652,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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);