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authorDenys Vlasenko <vda.linux@googlemail.com>2009-10-18 16:05:27 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2009-10-18 16:05:27 (GMT)
commitf9d3a91a89251cc4470a3cb94e918a49191438d2 (patch)
tree680c90260abb0ba65e6bb84acde6adfe80557d4b
parent77da1cae94acbeef90da66bf6530556fe191a6e2 (diff)
downloadbusybox-f9d3a91a89251cc4470a3cb94e918a49191438d2.tar.gz
busybox-f9d3a91a89251cc4470a3cb94e918a49191438d2.tar.bz2
mkfs_ext2: fixes for huge filesystems
function old new delta mkfs_ext2_main 2145 2617 +472 div_roundup 15 35 +20 packed_usage 26792 26776 -16 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--include/usage.h2
-rw-r--r--util-linux/mkfs_ext2.c66
2 files changed, 44 insertions, 24 deletions
diff --git a/include/usage.h b/include/usage.h
index bdd9ae3..80111e5 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -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" */ \
diff --git a/util-linux/mkfs_ext2.c b/util-linux/mkfs_ext2.c
index a990668..56203c7 100644
--- a/util-linux/mkfs_ext2.c
+++ b/util-linux/mkfs_ext2.c
@@ -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;