diff options
Diffstat (limited to 'util-linux')
| -rw-r--r-- | util-linux/mkfs_ext2.c | 78 | ||||
| -rwxr-xr-x | util-linux/mkfs_ext2_test.sh | 36 |
2 files changed, 69 insertions, 45 deletions
diff --git a/util-linux/mkfs_ext2.c b/util-linux/mkfs_ext2.c index e840f7810..da27dc77d 100644 --- a/util-linux/mkfs_ext2.c +++ b/util-linux/mkfs_ext2.c @@ -173,9 +173,9 @@ 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 reserved_percent = 5; unsigned long long kilobytes; - uint32_t nblocks, nblocks_full; + uint32_t nblocks, nblocks_full, nreserved; uint32_t ngroups; uint32_t bytes_per_inode; uint32_t first_data_block; @@ -194,13 +194,9 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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); + &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); @@ -228,14 +224,15 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) if (opts & OPT_i) bytes_per_inode = bpi; + // Determine block size // block size is a multiple of 1024 blocksize = 1024; if (kilobytes >= 512*1024) // mke2fs 1.41.9 compat blocksize = 4096; 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; } @@ -247,28 +244,38 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) ) { bb_error_msg_and_die("blocksize %u is bad", blocksize); } + // number of bits in one block, i.e. 8*blocksize +#define blocks_per_group (8 * blocksize) + first_data_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 - if (blocksize < PAGE_SIZE) - nblocks &= ~((PAGE_SIZE / blocksize)-1); + nblocks &= ~((PAGE_SIZE >> blocksize_log2)-1); + // Experimentally, standard mke2fs won't work on images smaller than 60k + if (nblocks < 60) + bb_error_msg_and_die("need >= 60 blocks"); + + // How many reserved blocks? + if (reserved_percent > 50) + bb_error_msg_and_die("-%c is bad", 'm'); + //nreserved = div_roundup((uint64_t) nblocks * reserved_percent, 100); + 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"); @@ -308,21 +315,21 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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 have no more than 8*blocksize inodes 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 * sizeof(*inode), blocksize) * blocksize) / sizeof(*inode); // 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? + // the last group needs more attention: isn'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"); - if (remainder && (remainder < overhead + 50)) { + if (remainder && (remainder < overhead + 50/* e2fsprogs hardcoded */)) { //bb_info_msg("CHOP[%u]", remainder); nblocks -= remainder; goto retry; @@ -348,8 +355,7 @@ 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 + , nreserved, reserved_percent , first_data_block , gdtsz * (blocksize / sizeof(*gd)) * blocks_per_group , ngroups @@ -399,7 +405,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) // 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); @@ -418,7 +424,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) | (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 + // e2fsck from 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_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER); STORE_LE(sb->s_flags, EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX); @@ -435,9 +441,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) 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); @@ -461,11 +466,6 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) STORE_LE(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) { -// n -= first_data_block; -// } // mark preallocated blocks as allocated fb = (n < blocks_per_group ? n : blocks_per_group) - overhead; @@ -500,8 +500,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) // 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 && 0 == first_data_block) ? 1024 : 0), sb, 1024);//blocksize); + PUT(((uint64_t)pos * blocksize) + blocksize, gd, gdtsz * blocksize); } } @@ -526,12 +526,12 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) // 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)); + PUT(((uint64_t)FETCH_LE32(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 - PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) << blocksize_log2) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode)); + PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode)); // dump directories memset(buf, 0, blocksize); diff --git a/util-linux/mkfs_ext2_test.sh b/util-linux/mkfs_ext2_test.sh index 9c20b3b89..53f15d2c8 100755 --- a/util-linux/mkfs_ext2_test.sh +++ b/util-linux/mkfs_ext2_test.sh @@ -23,7 +23,7 @@ run_test() { # params: mke2fs_invocation image_name test_mke2fs() { echo Testing $kilobytes - run_test '/usr/bin/mke2fs' image_std || return 1 + run_test '/sbin/mke2fs' image_std || return 1 run_test './busybox mke2fs' image_bb || return 1 diff -ua image_bb.out image_std.out >image.out.diff || { @@ -31,9 +31,33 @@ test_mke2fs() { return 1 } - e2fsck -f -n image_bb >/dev/null 2>&1 || { echo "e2fsck error on image_bb"; exit 1; } + e2fsck -f -n image_bb >/dev/null 2>&1 || { + echo "e2fsck error on image_bb" + e2fsck -f -n image_bb + exit 1 + } } +# Should start from kilobytes=60, but e2fsck complains on it: +# e2fsck 1.41.4 (27-Jan-2009) +# Pass 1: Checking inodes, blocks, and sizes +# Pass 2: Checking directory structure +# Pass 3: Checking directory connectivity +# Pass 4: Checking reference counts +# Pass 5: Checking group summary information +# Inode bitmap differences: +(9--11) +# Free inodes count wrong for group #0 (5, counted=8). +# Directories count wrong for group #0 (2, counted=1). +# Free inodes count wrong (5, counted=8). +# image_bb: 11/16 files (0.0% non-contiguous), 9/60 blocks +kilobytes=68 +while true; do + test_mke2fs #|| exit 1 + : $((kilobytes++)) +done +exit + +# Specific sizes with known differences: # -:bbox +:standard # -6240 inodes, 24908 blocks @@ -58,14 +82,14 @@ kilobytes=1218 test_mke2fs # +2064 inodes per group kilobytes=57696 test_mke2fs -# This size results in "warning: 75 blocks unused" -kilobytes=98380 test_mke2fs - # -warning: 239 blocks unused. # +warning: 242 blocks unused. kilobytes=49395 test_mke2fs +## This size results in "warning: 75 blocks unused" +#kilobytes=98380 test_mke2fs + while true; do - kilobytes=$(( (RANDOM*RANDOM) % 1000000 + 2000)) + kilobytes=$(( (RANDOM*RANDOM) % 1000000 + 60)) test_mke2fs || exit 1 done |