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mkfs_ext2: use compatible inode sizes; add -I <inodesize>. (by Vladimir)

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function                                             old     new   delta
mkfs_ext2_main                                      2385    2495    +110
packed_usage                                       26400   26447     +47
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 157/0)             Total: 157 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2009-10-22 12:12:17 +02:00
parent 3945bc1534
commit 149a32a19b
5 changed files with 46 additions and 30 deletions
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51
util-linux/mkfs_ext2.c
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@ -159,7 +159,7 @@ enum {
OPT_b = 1 << 2, // block size, in bytes
OPT_f = 1 << 3,
OPT_i = 1 << 4, // bytes per inode
OPT_I = 1 << 5,
OPT_I = 1 << 5, // custom inode size, in bytes
OPT_J = 1 << 6,
OPT_G = 1 << 7,
OPT_N = 1 << 8,
@ -188,6 +188,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
unsigned i, pos, n;
unsigned bs, bpi;
unsigned blocksize, blocksize_log2;
unsigned inodesize, user_inodesize;
unsigned reserved_percent = 5;
unsigned long long kilobytes;
uint32_t nblocks, nblocks_full;
@ -211,7 +212,7 @@ 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,
NULL, &bs, NULL, &bpi, &user_inodesize, NULL, NULL, NULL,
&reserved_percent, NULL, NULL, &label, NULL, NULL, NULL, NULL, NULL, NULL);
argv += optind; // argv[0] -- device
@ -249,11 +250,15 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
if (opts & OPT_i)
bytes_per_inode = bpi;
// Determine block size
// Determine block size and inode size
// block size is a multiple of 1024
// inode size is a multiple of 128
blocksize = 1024;
if (kilobytes >= 512*1024) // mke2fs 1.41.9 compat
inodesize = sizeof(struct ext2_inode); // 128
if (kilobytes >= 512*1024) { // mke2fs 1.41.9 compat
blocksize = 4096;
inodesize = 256;
}
if (EXT2_MAX_BLOCK_SIZE > 4096) {
// kilobytes >> 22 == size in 4gigabyte chunks.
// if size >= 16k gigs, blocksize must be increased.
@ -269,6 +274,18 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
) {
bb_error_msg_and_die("blocksize %u is bad", blocksize);
}
// Do we have custom inode size?
if (opts & OPT_I) {
if (user_inodesize < sizeof(*inode)
|| user_inodesize > blocksize
|| (user_inodesize & (user_inodesize - 1)) // not power of 2
) {
bb_error_msg("-%c is bad", 'I');
} else {
inodesize = user_inodesize;
}
}
if ((int32_t)bytes_per_inode < blocksize)
bb_error_msg_and_die("-%c is bad", 'i');
// number of bits in one block, i.e. 8*blocksize
@ -340,14 +357,10 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
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
//incompatibility on images >= 0.5GB:
//difference in sizeof(*inode) sometimes
//results in slightly bigger inodes_per_group here
//compared to standard mke2fs:
inodes_per_group = (div_roundup(inodes_per_group * sizeof(*inode), blocksize) * blocksize) / sizeof(*inode);
inodes_per_group = (div_roundup(inodes_per_group * inodesize, blocksize) * blocksize) / inodesize;
// make sure the number of inodes per group is a multiple of 8
inodes_per_group &= ~7;
inode_table_blocks = div_roundup(inodes_per_group * sizeof(*inode), blocksize);
inode_table_blocks = div_roundup(inodes_per_group * inodesize, blocksize);
// to be useful, lost+found should occupy at least 2 blocks (but not exceeding 16*1024 bytes),
// and at most EXT2_NDIR_BLOCKS. So reserve these blocks right now
@ -434,12 +447,12 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
// fill the superblock
sb = xzalloc(1024);
STORE_LE(sb->s_rev_level, 1); // revision 1 filesystem
STORE_LE(sb->s_rev_level, EXT2_DYNAMIC_REV); // revision 1 filesystem
STORE_LE(sb->s_magic, EXT2_SUPER_MAGIC);
//incompatibility:
//on images > 0.5GB, standard mke2fs uses 256 byte inodes.
//we always use 128 byte ones:
STORE_LE(sb->s_inode_size, sizeof(*inode));
STORE_LE(sb->s_inode_size, inodesize);
// set "Required extra isize" and "Desired extra isize" fields to 28
if (inodesize != sizeof(*inode))
STORE_LE(sb->s_reserved[21], 0x001C001C);
STORE_LE(sb->s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
STORE_LE(sb->s_log_block_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
STORE_LE(sb->s_log_frag_size, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE);
@ -592,8 +605,8 @@ 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) + inode_table_blocks);
PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * sizeof(*inode),
buf, sizeof(*inode));
PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (EXT2_ROOT_INO-1) * inodesize,
buf, inodesize);
// dump lost+found dir inode
STORE_LE(inode->i_links_count, 2); // both "/lost+found" and "/lost+found/." point to this inode
@ -603,8 +616,8 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
for (i = 0; i < lost_and_found_blocks; ++i)
STORE_LE(inode->i_block[i], i + n); // use next block
//bb_info_msg("LAST BLOCK USED[%u]", i + n);
PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) * blocksize) + (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) * inodesize,
buf, inodesize);
// dump directories
memset(buf, 0, blocksize);