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authorDenys Vlasenko2009-10-18 16:29:30 +0200
committerDenys Vlasenko2009-10-18 16:29:30 +0200
commit77da1cae94acbeef90da66bf6530556fe191a6e2 (patch)
tree712db9a18d648b14cc6c7e587e8c4edbe11fd079 /util-linux/mkfs_ext2.c
parentf37eb3999bce2ea46fef0214e33279b81609e596 (diff)
downloadbusybox-77da1cae94acbeef90da66bf6530556fe191a6e2.zip
busybox-77da1cae94acbeef90da66bf6530556fe191a6e2.tar.gz
mkfs_ext2: make it able to create images larger than 4G
function old new delta mkfs_ext2_main 1904 2145 +241 has_super 29 23 -6 PUT 52 40 -12 packed_usage 26807 26792 -15 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/3 up/down: 241/-33) Total: 208 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'util-linux/mkfs_ext2.c')
-rw-r--r--util-linux/mkfs_ext2.c150
1 files changed, 95 insertions, 55 deletions
diff --git a/util-linux/mkfs_ext2.c b/util-linux/mkfs_ext2.c
index 8df9f1a..a990668 100644
--- a/util-linux/mkfs_ext2.c
+++ b/util-linux/mkfs_ext2.c
@@ -77,33 +77,18 @@ static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32
{
uint32_t i;
memset(bitmap, 0, blocksize);
- i = start/8;
+ i = start / 8;
memset(bitmap, 0xFF, i);
bitmap[i] = 0xFF >> (8-(start&7));
//bb_info_msg("ALLOC: [%u][%u][%u]: [%u]:=[%x]", blocksize, start, end, blocksize - end/8 - 1, (uint8_t)(0xFF << (8-(end&7))));
- i = end/8;
- bitmap[blocksize - i - 1] = 0xFF << (8-(end&7));
+ i = end / 8;
+ bitmap[blocksize - i - 1] = 0xFF << (8 - (end & 7));
memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
}
-#if 0
-// TODO: get rid of FPU
-static bool is_power_of(uint32_t x, uint16_t n)
-{
-// return (!(x % n) && is_power_of(x / n, n));
- double z = logf(x)/logf(n);
- return (z == (int)z);
-}
-
-static uint32_t has_super(uint32_t x)
-{
- return (0 == x || 1 == x || is_power_of(x, 3) || is_power_of(x, 5) || is_power_of(x, 7));
-}
-
-#else
-
static uint32_t has_super(uint32_t x)
{
+ // 0, 1 and powers of 3, 5, 7 up to 2^32 limit
static const uint32_t supers[] = {
0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729,
2187, 2401, 3125, 6561, 15625, 16807, 19683, 59049, 78125,
@@ -112,16 +97,15 @@ static uint32_t has_super(uint32_t x)
48828125, 129140163, 244140625, 282475249, 387420489,
1162261467, 1220703125, 1977326743, 3486784401/* >2^31 */,
};
- const uint32_t *sp = supers + ARRAY_SIZE(supers)-1;
+ const uint32_t *sp = supers + ARRAY_SIZE(supers);
while (1) {
+ sp--;
if (x == *sp)
return 1;
- if (0 == *sp)
+ if (x > *sp)
return 0;
- sp--;
}
}
-#endif
/* Standard mke2fs 1.41.9:
* Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size]
@@ -154,7 +138,7 @@ enum {
OPT_T = 1 << 17,
OPT_U = 1 << 18,
OPT_j = 1 << 19,
- OPT_n = 1 << 20,
+ OPT_n = 1 << 20, // dry run: do not write anything
OPT_q = 1 << 21,
OPT_v = 1 << 22,
OPT_F = 1 << 23,
@@ -166,17 +150,16 @@ enum {
static void PUT(uint64_t off, void *buf, uint32_t size)
{
- if (!(option_mask32 & OPT_n)) {
- xlseek(fd, off, SEEK_SET);
- xwrite(fd, buf, 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, blocksize;
+ unsigned bs, blocksize, blocksize_log2;
unsigned nreserved = 5;
uint32_t nblocks;
uint32_t ngroups;
@@ -235,7 +218,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
// TODO: 0/5 info printing
// TODO: 2/5 bigendianness! Spot where it comes to play! sb->, gd->
// TODO: 2/5 reserved GDT: how to mark but not allocate?
- // TODO: 0/5 dir_index?
+ // TODO: 3/5 dir_index?
// fill the superblock
sb = xzalloc(blocksize);
@@ -243,13 +226,14 @@ 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;
- sb->s_log_block_size = sb->s_log_frag_size = int_log2(blocksize >> EXT2_MIN_BLOCK_LOG_SIZE);
+ 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
first_data_block = sb->s_first_data_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
// block and inode bitmaps occupy no more than one block, so maximum number of blocks is
// number of bits in one block, i.e. 8*blocksize
- nblocks_per_group = sb->s_blocks_per_group = sb->s_frags_per_group = sb->s_inodes_per_group = 8*blocksize;
+ nblocks_per_group = sb->s_blocks_per_group = sb->s_frags_per_group = sb->s_inodes_per_group = 8 * blocksize;
timestamp = time(NULL);
sb->s_mkfs_time = sb->s_wtime = sb->s_lastcheck = timestamp;
sb->s_state = 1;
@@ -266,10 +250,10 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
sb->s_feature_ro_compat = EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER;
sb->s_flags = EXT2_FLAGS_SIGNED_HASH * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX;
generate_uuid(sb->s_uuid);
-#if ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX
- sb->s_def_hash_version = EXT2_HASH_HALF_MD4;
- generate_uuid((uint8_t *)sb->s_hash_seed);
-#endif
+ if (ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX) {
+ sb->s_def_hash_version = EXT2_HASH_HALF_MD4;
+ generate_uuid((uint8_t *)sb->s_hash_seed);
+ }
/*
* From e2fsprogs: add "jitter" to the superblock's check interval so that we
* don't check all the filesystems at the same time. We use a
@@ -282,7 +266,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
if (argv[1]) {
nblocks = xatou(argv[1]);
} else {
- nblocks = ((uoff_t)xlseek(fd, 0, SEEK_END)) / blocksize;
+ nblocks = (uoff_t)xlseek(fd, 0, SEEK_END) >> blocksize_log2;
}
sb->s_blocks_count = nblocks;
@@ -328,17 +312,17 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
if (nblocks < 3*1024)
bytes_per_inode = 8192;
}
- ninodes = nblocks / (bytes_per_inode / blocksize);
+ ninodes = nblocks / (bytes_per_inode >> blocksize_log2);
if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
ninodes_per_group = div_roundup(ninodes, ngroups);
if (ninodes_per_group < 16)
- ninodes_per_group = 16; // minimum number because the first 10 are reserved
+ ninodes_per_group = 16; // minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
// N.B. a block group can have no more than 8*blocksize = sb->s_inodes_per_group inodes
if (ninodes_per_group > sb->s_inodes_per_group)
ninodes_per_group = sb->s_inodes_per_group;
// adjust inodes per group so they completely fill the inode table blocks in the descriptor
- ninodes_per_group = ((div_roundup(ninodes_per_group * EXT2_INODE_SIZE(sb), blocksize) * blocksize) / EXT2_INODE_SIZE(sb));
+ ninodes_per_group = (div_roundup(ninodes_per_group * EXT2_INODE_SIZE(sb), blocksize) << blocksize_log2) / EXT2_INODE_SIZE(sb);
// make sure the number of inodes per group is a multiple of 8
ninodes_per_group &= ~7;
sb->s_inodes_per_group = ninodes_per_group;// = div_roundup(ninodes_per_group * sb->s_inode_size, blocksize);
@@ -352,6 +336,52 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
if (opts & OPT_L)
safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
+#if 1
+/* if (fs_param.s_blocks_count != s->s_blocks_count)
+ fprintf(stderr, _("warning: %u blocks unused.\n\n"),
+ fs_param.s_blocks_count - s->s_blocks_count);
+*/
+
+ printf(
+ "Filesystem label=%s\n"
+ "OS type: Linux\n"
+ "Block size=%u (log=%u)\n"
+ "Fragment size=%u (log=%u)\n"
+ "%u inodes, %u blocks\n"
+ "%u blocks (%u%%) reserved for the super user\n"
+ "First data block=%u\n"
+// "Maximum filesystem blocks=%lu\n"
+ "%u block groups\n"
+ "%u blocks per group, %u fragments per group\n"
+ "%u inodes per group"
+ , (char *)sb->s_volume_name
+ , blocksize, sb->s_log_block_size
+ , blocksize, sb->s_log_block_size
+ , sb->s_inodes_count, sb->s_blocks_count
+ , sb->s_r_blocks_count, nreserved
+ , first_data_block
+// , (rgdtsz + gdtsz) * EXT2_DESC_PER_BLOCK(sb) * nblocks_per_group
+ , ngroups
+ , nblocks_per_group, nblocks_per_group
+ , ninodes_per_group
+ );
+ {
+ const char *fmt = "\nSuperblock backups stored on blocks: %u";
+ pos = first_data_block;
+ for (i = 1; i < ngroups; i++) {
+ pos += nblocks_per_group;
+ if (has_super(i)) {
+ printf(fmt, (unsigned)pos);
+ fmt = ", %u";
+ }
+ }
+ }
+ bb_putchar('\n');
+#endif
+
+ if (opts & OPT_n)
+ return EXIT_SUCCESS;
+
// fill group descriptors
gd = xzalloc((gdtsz + rgdtsz) * blocksize);
sb->s_free_blocks_count = 0;
@@ -365,8 +395,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
gd[i].bg_inode_table = overhead + 2;
overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
gd[i].bg_free_inodes_count = ninodes_per_group;
- // N.B. both root and lost+found dirs are within the first block group, thus +2
//gd[i].bg_used_dirs_count = 0;
+ // N.B. both root and lost+found dirs are within the first block group, thus +2
if (0 == i) {
overhead += 2;
gd[i].bg_used_dirs_count = 2;
@@ -383,6 +413,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
// dump filesystem skeleton structures
+// printf("Writing superblocks and filesystem accounting information: ");
buf = xmalloc(blocksize);
for (i = 0, pos = first_data_block; i < ngroups; i++, pos += nblocks_per_group) {
uint32_t overhead = has_super(i) ? (1/*sb*/ + gdtsz + rgdtsz) : 0;
@@ -391,28 +422,30 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
// dump superblock and group descriptors and their backups
if (overhead) { // N.B. in fact, we want (has_super(i)) condition, but it is equal to (overhead != 0) and is cheaper
-//bb_info_msg("SUPER@[%d]", pos);
// N.B. 1024 byte blocks are special
- PUT(blocksize * pos + ((0 == i && 0 == first_data_block) ? 1024 : 0), sb, blocksize);
- PUT(blocksize * pos + blocksize, gd, (gdtsz + rgdtsz) * blocksize);
+ 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 + rgdtsz) * blocksize);
}
start = overhead + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
if (i == 0)
- start += 2; // for / and /lost+found
+ start += 2; // for "/" and "/lost+found"
end = nblocks_per_group - (start + gd[i].bg_free_blocks_count);
+
// mark preallocated blocks as allocated
allocate(buf, blocksize, start, end);
// dump block bitmap
- PUT((pos + overhead) * blocksize, buf, blocksize);
+ PUT((uint64_t)(pos + overhead) * blocksize, buf, blocksize);
// mark preallocated inodes as allocated
allocate(buf, blocksize,
ninodes_per_group - gd[i].bg_free_inodes_count,
- 8*blocksize - ninodes_per_group
+ 8 * blocksize - ninodes_per_group
);
// dump inode bitmap
- PUT((pos + overhead + 1) * blocksize, buf, blocksize);
+ //PUT((uint64_t)(pos + overhead + 1) * blocksize, buf, blocksize);
+ //but it's right after block bitmap, so we can just:
+ xwrite(fd, buf, blocksize);
}
// zero boot sectors
@@ -421,12 +454,13 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
// zero inode tables
for (i = 0; i < ngroups; ++i)
for (n = 0; n < itsz; ++n)
- PUT((gd[i].bg_inode_table + n) * blocksize, buf, blocksize);
+ PUT((uint64_t)(gd[i].bg_inode_table + n) * blocksize, buf, blocksize);
// prepare directory inode
inode = (struct ext2_inode *)buf;
STORE_LE(inode->i_mode, S_IFDIR | S_IRWXU | S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH);
- inode->i_mtime = inode->i_atime = timestamp;
+ STORE_LE(inode->i_mtime, timestamp);
+ 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?!
@@ -435,12 +469,12 @@ 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], gd[0].bg_inode_table + itsz);
- PUT(gd[0].bg_inode_table * blocksize + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode));
+ PUT(((uint64_t)gd[0].bg_inode_table << blocksize_log2) + (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 //= gd[0].bg_inode_table + itsz + 1;
- PUT(gd[0].bg_inode_table * blocksize + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
+ PUT(((uint64_t)gd[0].bg_inode_table << blocksize_log2) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
// dump directories
memset(buf, 0, blocksize);
@@ -457,7 +491,7 @@ 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((gd[0].bg_inode_table + itsz + 1) * blocksize, buf, blocksize);
+ PUT((uint64_t)(gd[0].bg_inode_table + itsz + 1) * blocksize, buf, blocksize);
// dump root dir block
STORE_LE(dir->inode1, EXT2_ROOT_INO);
@@ -467,15 +501,21 @@ 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((gd[0].bg_inode_table + itsz + 0) * blocksize, buf, blocksize);
+ PUT((uint64_t)(gd[0].bg_inode_table + itsz + 0) * blocksize, buf, blocksize);
+
+// bb_info_msg("done\n"
+// "This filesystem will be automatically checked every %u mounts or\n"
+// "%u days, whichever comes first. Use tune2fs -c or -i to override.",
+// sb->s_max_mnt_count, sb->s_checkinterval / (3600 * 24)
+// );
// cleanup
if (ENABLE_FEATURE_CLEAN_UP) {
free(buf);
free(gd);
free(sb);
- close(fd);
}
+ xclose(fd);
return EXIT_SUCCESS;
}