mkfs_ext2: further work by Vladimir
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
parent
69f2e2cdeb
commit
95484c8706
@ -173,9 +173,9 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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unsigned i, pos, n;
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unsigned bs, bpi;
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unsigned blocksize, blocksize_log2;
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unsigned nreserved = 5;
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unsigned reserved_percent = 5;
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unsigned long long kilobytes;
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uint32_t nblocks, nblocks_full;
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uint32_t nblocks, nblocks_full, nreserved;
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uint32_t ngroups;
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uint32_t bytes_per_inode;
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uint32_t first_data_block;
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@ -194,13 +194,9 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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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, &bpi, NULL, NULL, NULL, NULL,
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&nreserved, NULL, NULL, &label, NULL, NULL, NULL, NULL, NULL, NULL);
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&reserved_percent, NULL, NULL, &label, NULL, NULL, NULL, NULL, NULL, NULL);
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argv += optind; // argv[0] -- device
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// reserved blocks percentage
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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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xmove_fd(xopen(argv[0], O_WRONLY), fd);
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fstat(fd, &st);
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@ -228,14 +224,15 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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if (opts & OPT_i)
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bytes_per_inode = bpi;
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// Determine block size
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// block size is a multiple of 1024
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blocksize = 1024;
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if (kilobytes >= 512*1024) // mke2fs 1.41.9 compat
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blocksize = 4096;
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if (EXT2_MAX_BLOCK_SIZE > 4096) {
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// kilobytes >> 22 == size in 4gigabyte chunks.
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// if it is >= 16k gigs, blocksize must be increased.
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// Try "mke2fs -F image_std $((16 * 1024*1024*1024))"
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// if size >= 16k gigs, blocksize must be increased.
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// Try "mke2fs -F image $((16 * 1024*1024*1024))"
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while ((kilobytes >> 22) >= blocksize)
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blocksize *= 2;
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}
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@ -247,28 +244,38 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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) {
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bb_error_msg_and_die("blocksize %u is bad", blocksize);
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}
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// number of bits in one block, i.e. 8*blocksize
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#define blocks_per_group (8 * blocksize)
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first_data_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
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blocksize_log2 = int_log2(blocksize);
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// Determine number of blocks
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kilobytes >>= (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
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// nblocks: the total number of blocks in the filesystem
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nblocks = kilobytes;
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if (nblocks != kilobytes)
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bb_error_msg_and_die("block count doesn't fit in 32 bits");
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#define kilobytes kilobytes_unused_after_this
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if (blocksize < PAGE_SIZE)
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nblocks &= ~((PAGE_SIZE / blocksize)-1);
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nblocks &= ~((PAGE_SIZE >> blocksize_log2)-1);
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// Experimentally, standard mke2fs won't work on images smaller than 60k
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if (nblocks < 60)
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bb_error_msg_and_die("need >= 60 blocks");
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// How many reserved blocks?
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if (reserved_percent > 50)
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bb_error_msg_and_die("-%c is bad", 'm');
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//nreserved = div_roundup((uint64_t) nblocks * reserved_percent, 100);
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nreserved = (uint64_t)nblocks * reserved_percent / 100;
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// N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
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nblocks_full = nblocks;
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// If last block group is too small, nblocks may be decreased in order
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// to discard it, and control returns here to recalculate some
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// parameters.
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// Note: blocksize and bytes_per_inode are never recalculated.
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retry:
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if (nblocks < 8)
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bb_error_msg_and_die("need >= 8 blocks");
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// number of bits in one block, i.e. 8*blocksize
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#define blocks_per_group (8 * blocksize)
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// N.B. a block group can have no more than blocks_per_group blocks
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first_data_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
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ngroups = div_roundup(nblocks - first_data_block, blocks_per_group);
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if (0 == ngroups)
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bb_error_msg_and_die("ngroups");
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@ -308,21 +315,21 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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if (inodes_per_group < 16)
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inodes_per_group = 16;
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// N.B. a block group can have no more than 8*blocksize inodes
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// a block group can have no more than 8*blocksize inodes
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if (inodes_per_group > blocks_per_group)
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inodes_per_group = blocks_per_group;
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// adjust inodes per group so they completely fill the inode table blocks in the descriptor
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inodes_per_group = (div_roundup(inodes_per_group * sizeof(*inode), blocksize) << blocksize_log2) / sizeof(*inode);
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inodes_per_group = (div_roundup(inodes_per_group * sizeof(*inode), blocksize) * blocksize) / sizeof(*inode);
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// make sure the number of inodes per group is a multiple of 8
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inodes_per_group &= ~7;
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itsz = div_roundup(inodes_per_group * sizeof(*inode), blocksize);
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// the last block needs more attention: doesn't it too small for possible overhead?
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// the last group needs more attention: isn't it too small for possible overhead?
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overhead = (has_super(ngroups - 1) ? (1/*sb*/ + gdtsz) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
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remainder = (nblocks - first_data_block) % blocks_per_group;
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if ((1 == ngroups) && remainder && (remainder < overhead))
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bb_error_msg_and_die("way small device");
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if (remainder && (remainder < overhead + 50)) {
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if (remainder && (remainder < overhead + 50/* e2fsprogs hardcoded */)) {
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//bb_info_msg("CHOP[%u]", remainder);
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nblocks -= remainder;
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goto retry;
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@ -348,8 +355,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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, blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
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, blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
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, inodes_per_group * ngroups, nblocks
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//, div_roundup((uint64_t) nblocks * nreserved, 100), nreserved
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, (unsigned)((uint64_t) nblocks_full * nreserved / 100), nreserved
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, nreserved, reserved_percent
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, first_data_block
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, gdtsz * (blocksize / sizeof(*gd)) * blocks_per_group
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, ngroups
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@ -399,7 +405,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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// blocks
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STORE_LE(sb->s_blocks_count, nblocks);
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// reserve blocks for superuser
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STORE_LE(sb->s_r_blocks_count, (uint32_t)((uint64_t) nblocks_full * nreserved / 100));
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STORE_LE(sb->s_r_blocks_count, nreserved);
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// ninodes
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STORE_LE(sb->s_inodes_per_group, inodes_per_group);
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STORE_LE(sb->s_inodes_count, inodes_per_group * ngroups);
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@ -418,7 +424,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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| (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
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| (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
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);
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// e2fsprogs-1.41.9 doesn't like EXT2_FEATURE_INCOMPAT_WHITEOUT
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// e2fsck from 1.41.9 doesn't like EXT2_FEATURE_INCOMPAT_WHITEOUT
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STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);// | EXT2_FEATURE_INCOMPAT_WHITEOUT;
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STORE_LE(sb->s_feature_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
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STORE_LE(sb->s_flags, EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX);
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@ -435,9 +441,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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STORE_LE(sb->s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT
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+ (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
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// write the label, if any
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if (label) //opts & OPT_L)
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safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
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// write the label
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safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
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// fill group descriptors
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gd = xzalloc(gdtsz * blocksize);
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@ -461,11 +466,6 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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STORE_LE(gd[i].bg_used_dirs_count, 2);
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gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
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}
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// // N.B. the following is pure heuristics!
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// // Likely to cope with 1024-byte blocks, when first block is for boot sectors
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// if (ngroups-1 == i) {
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// n -= first_data_block;
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// }
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// mark preallocated blocks as allocated
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fb = (n < blocks_per_group ? n : blocks_per_group) - overhead;
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@ -500,8 +500,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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// dump superblock and group descriptors and their backups
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if (has_super(i)) {
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// N.B. 1024 byte blocks are special
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PUT(((uint64_t)pos << blocksize_log2) + ((0 == i && 0 == first_data_block) ? 1024 : 0), sb, 1024);//blocksize);
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PUT(((uint64_t)pos << blocksize_log2) + blocksize, gd, gdtsz * blocksize);
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PUT(((uint64_t)pos * blocksize) + ((0 == i && 0 == first_data_block) ? 1024 : 0), sb, 1024);//blocksize);
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PUT(((uint64_t)pos * blocksize) + blocksize, gd, gdtsz * blocksize);
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}
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}
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@ -526,12 +526,12 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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// dump root dir inode
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STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this inode
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STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + itsz);
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PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) << blocksize_log2) + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode));
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PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode));
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// dump lost+found dir inode
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STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
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STORE_LE(inode->i_block[0], inode->i_block[0]+1); // use next block
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PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) << blocksize_log2) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
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PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
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// dump directories
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memset(buf, 0, blocksize);
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@ -23,7 +23,7 @@ run_test() { # params: mke2fs_invocation image_name
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test_mke2fs() {
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echo Testing $kilobytes
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run_test '/usr/bin/mke2fs' image_std || return 1
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run_test '/sbin/mke2fs' image_std || return 1
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run_test './busybox mke2fs' image_bb || return 1
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diff -ua image_bb.out image_std.out >image.out.diff || {
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@ -31,9 +31,33 @@ test_mke2fs() {
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return 1
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}
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e2fsck -f -n image_bb >/dev/null 2>&1 || { echo "e2fsck error on image_bb"; exit 1; }
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e2fsck -f -n image_bb >/dev/null 2>&1 || {
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echo "e2fsck error on image_bb"
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e2fsck -f -n image_bb
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exit 1
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}
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}
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# Should start from kilobytes=60, but e2fsck complains on it:
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# e2fsck 1.41.4 (27-Jan-2009)
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# Pass 1: Checking inodes, blocks, and sizes
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# Pass 2: Checking directory structure
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# Pass 3: Checking directory connectivity
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# Pass 4: Checking reference counts
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# Pass 5: Checking group summary information
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# Inode bitmap differences: +(9--11)
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# Free inodes count wrong for group #0 (5, counted=8).
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# Directories count wrong for group #0 (2, counted=1).
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# Free inodes count wrong (5, counted=8).
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# image_bb: 11/16 files (0.0% non-contiguous), 9/60 blocks
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kilobytes=68
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while true; do
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test_mke2fs #|| exit 1
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: $((kilobytes++))
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done
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exit
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# Specific sizes with known differences:
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# -:bbox +:standard
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# -6240 inodes, 24908 blocks
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@ -58,14 +82,14 @@ kilobytes=1218 test_mke2fs
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# +2064 inodes per group
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kilobytes=57696 test_mke2fs
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# This size results in "warning: 75 blocks unused"
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kilobytes=98380 test_mke2fs
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# -warning: 239 blocks unused.
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# +warning: 242 blocks unused.
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kilobytes=49395 test_mke2fs
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## This size results in "warning: 75 blocks unused"
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#kilobytes=98380 test_mke2fs
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while true; do
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kilobytes=$(( (RANDOM*RANDOM) % 1000000 + 2000))
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kilobytes=$(( (RANDOM*RANDOM) % 1000000 + 60))
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test_mke2fs || exit 1
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done
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