f9d3a91a8
Denys Vlasenko
2009-10-18
Subject
mkfs_ext2: fixes for huge filesystems
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include/usage.h+1 -1
| @@ -2724,7 +2724,7 @@ | |
| "[-L LABEL] " \ | |
| "[-n] " \ | |
| /* "[-M last-mounted-directory] [-S] [-T filesystem-type] " */ \ | |
| - | "DEVICE [BLK_COUNT]" |
| + | "DEVICE [KBYTES]" |
| #define mkfs_ext2_full_usage "\n" \ | |
| "\n -b BLK_SIZE Block size in bytes" \ | |
| /* "\n -c Check for bad blocks before creating" */ \ | |
util-linux/mkfs_ext2.c+43 -23
| @@ -70,7 +70,11 @@ static unsigned int_log2(unsigned arg) | |
| // taken from mkfs_minix.c. libbb candidate? | |
| static unsigned div_roundup(uint32_t size, uint32_t n) | |
| { | |
| - | return (size + n-1) / n; |
| + | // Overflow-resistant |
| + | uint32_t res = size / n; |
| + | if (res * n != size) |
| + | res++; |
| + | return res; |
| } | |
| static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32_t end) | |
| @@ -161,6 +165,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) | |
| unsigned i, pos, n; | |
| unsigned bs, blocksize, blocksize_log2; | |
| unsigned nreserved = 5; | |
| + | unsigned long long nblocks_ull; |
| uint32_t nblocks; | |
| uint32_t ngroups; | |
| unsigned bytes_per_inode; | |
| @@ -179,23 +184,13 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) | |
| struct ext2_dir *dir; | |
| uint8_t *buf; | |
| - | bs = EXT2_MIN_BLOCK_SIZE; |
| 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, &bytes_per_inode, NULL, NULL, NULL, NULL, | |
| &nreserved, NULL, NULL, &label, NULL, NULL, NULL, NULL, NULL, NULL); | |
| argv += optind; // argv[0] -- device | |
| - | // block size minimax, block size is a multiple of minimum |
| - | blocksize = bs; |
| - | if (blocksize < EXT2_MIN_BLOCK_SIZE |
| - | || blocksize > EXT2_MAX_BLOCK_SIZE |
| - | || (blocksize & (blocksize - 1)) // not power of 2 |
| - | ) { |
| - | bb_error_msg_and_die("-%c is bad", 'b'); |
| - | } |
| - | |
| - | // reserved blocks count |
| + | // reserved blocks percentage |
| if (nreserved > 50) | |
| bb_error_msg_and_die("-%c is bad", 'm'); | |
| @@ -210,6 +205,42 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) | |
| if (find_mount_point(argv[0], 0)) | |
| bb_error_msg_and_die("can't format mounted filesystem"); | |
| + | // open the device, get size in kbytes |
| + | xmove_fd(xopen3(argv[0], O_WRONLY | O_CREAT, 0666), fd); |
| + | if (argv[1]) { |
| + | nblocks_ull = xatoull(argv[1]); |
| + | } else { |
| + | nblocks_ull = (uoff_t)xlseek(fd, 0, SEEK_END) / 1024; |
| + | } |
| + | |
| + | // block size is a multiple of 1024 |
| + | blocksize = 1024; |
| + | if (nblocks_ull >= 512*1024) // mke2fs 1.41.9 compat |
| + | blocksize = 4096; |
| + | if (EXT2_MAX_BLOCK_SIZE > 4096) { |
| + | // nblocks_ull >> 22 == size in 4gigabyte chunks. |
| + | // if it is >= 16k gigs, blocksize must be increased. |
| + | // Try "mke2fs -F image_std $((16 * 1024*1024*1024))" |
| + | while ((nblocks_ull >> 22) >= blocksize) |
| + | blocksize *= 2; |
| + | } |
| + | if (opts & OPT_b) |
| + | blocksize = bs; |
| + | if (blocksize < EXT2_MIN_BLOCK_SIZE |
| + | || blocksize > EXT2_MAX_BLOCK_SIZE |
| + | || (blocksize & (blocksize - 1)) // not power of 2 |
| + | ) { |
| + | bb_error_msg_and_die("blocksize %u is bad", blocksize); |
| + | } |
| + | blocksize_log2 = int_log2(blocksize); |
| + | nblocks_ull >>= (blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE); |
| + | // nblocks: the total number of blocks in the filesystem |
| + | nblocks = nblocks_ull; |
| + | if (nblocks != nblocks_ull) |
| + | bb_error_msg_and_die("block count doesn't fit in 32 bits"); |
| + | if (nblocks < 8) |
| + | bb_error_msg_and_die("need >= 8 blocks"); |
| + | |
| // TODO: 5?/5 WE MUST NOT DEPEND ON WHETHER DEVICE IS /dev/zero 'ed OR NOT | |
| // TODO: 3/5 refuse if mounted | |
| // TODO: 4/5 compat options | |
| @@ -226,7 +257,6 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) | |
| sb->s_magic = EXT2_SUPER_MAGIC; | |
| sb->s_inode_size = sizeof(*inode); | |
| sb->s_first_ino = EXT2_GOOD_OLD_FIRST_INO; | |
| - | blocksize_log2 = int_log2(blocksize); |
| sb->s_log_block_size = sb->s_log_frag_size = blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE; | |
| // first 1024 bytes of the device are for boot record. If block size is 1024 bytes, then | |
| // the first block available for data is 1, otherwise 0 | |
| @@ -261,18 +291,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) | |
| */ | |
| sb->s_max_mnt_count += sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % 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_log2; |
| - | } |
| 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; | |