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mkfs_ext2: compat fixes

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Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2009-10-20 00:06:03 +02:00
parent 3ef4f77620
commit 05647b5551
2 changed files with 249 additions and 225 deletions
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383
util-linux/mkfs_ext2.c
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@ -10,6 +10,10 @@
#include "libbb.h" #include "libbb.h"
#include <linux/fs.h> #include <linux/fs.h>
#include <linux/ext2_fs.h> #include <linux/ext2_fs.h>
#include <sys/user.h> /* PAGE_SIZE */
#ifndef PAGE_SIZE
# define PAGE_SIZE 4096
#endif
#include "volume_id/volume_id_internal.h" #include "volume_id/volume_id_internal.h"
#define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0 #define ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT 0
@ -26,8 +30,8 @@
//#define LINUX_S_IFWHT 0160000 //#define LINUX_S_IFWHT 0160000
//#define EXT2_FEATURE_INCOMPAT_WHITEOUT 0x0020 //#define EXT2_FEATURE_INCOMPAT_WHITEOUT 0x0020
// storage helper // storage helpers
void BUG_unsupported_field_size(void); char BUG_wrong_field_size(void);
#define STORE_LE(field, value) \ #define STORE_LE(field, value) \
do { \ do { \
if (sizeof(field) == 4) \ if (sizeof(field) == 4) \
@ -37,9 +41,12 @@ do { \
else if (sizeof(field) == 1) \ else if (sizeof(field) == 1) \
field = (value); \ field = (value); \
else \ else \
BUG_unsupported_field_size(); \ BUG_wrong_field_size(); \
} while (0) } while (0)
#define FETCH_LE32(field) \
(sizeof(field) == 4 ? cpu_to_le32(field) : BUG_wrong_field_size())
// All fields are little-endian // All fields are little-endian
struct ext2_dir { struct ext2_dir {
uint32_t inode1; uint32_t inode1;
@ -68,10 +75,10 @@ static unsigned int_log2(unsigned arg)
} }
// taken from mkfs_minix.c. libbb candidate? // taken from mkfs_minix.c. libbb candidate?
static unsigned div_roundup(uint32_t size, uint32_t n) static unsigned div_roundup(uint64_t size, uint32_t n)
{ {
// Overflow-resistant // Overflow-resistant
uint32_t res = size / n; uint64_t res = size / n;
if (res * n != size) if (res * n != size)
res++; res++;
return res; return res;
@ -83,8 +90,8 @@ static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32
memset(bitmap, 0, blocksize); memset(bitmap, 0, blocksize);
i = start / 8; i = start / 8;
memset(bitmap, 0xFF, i); memset(bitmap, 0xFF, i);
bitmap[i] = 0xFF >> (8-(start&7)); 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)))); //bb_info_msg("ALLOC: [%u][%u][%u]: [%u-%u]:=[%x],[%x]", blocksize, start, end, start/8, blocksize - end/8 - 1, 0xFF >> (8 - (start & 7)), (uint8_t)(0xFF << (8-(end&7))));
i = end / 8; i = end / 8;
bitmap[blocksize - i - 1] = 0xFF << (8 - (end & 7)); bitmap[blocksize - i - 1] = 0xFF << (8 - (end & 7));
memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here! memset(bitmap + blocksize - i, 0xFF, i); // N.B. no overflow here!
@ -167,15 +174,15 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
unsigned blocksize, blocksize_log2; unsigned blocksize, blocksize_log2;
unsigned nreserved = 5; unsigned nreserved = 5;
unsigned long long kilobytes; unsigned long long kilobytes;
uint32_t nblocks; uint32_t nblocks, nblocks_full;
uint32_t ngroups; uint32_t ngroups;
uint32_t bytes_per_inode; uint32_t bytes_per_inode;
uint32_t first_data_block; uint32_t first_data_block;
uint32_t ninodes_per_group; uint32_t inodes_per_group;
uint32_t gdtsz, itsz; uint32_t gdtsz, itsz;
time_t timestamp; time_t timestamp;
unsigned opts; unsigned opts;
const char *label; const char *label = "";
struct stat st; struct stat st;
struct ext2_super_block *sb; // superblock struct ext2_super_block *sb; // superblock
struct ext2_group_desc *gd; // group descriptors struct ext2_group_desc *gd; // group descriptors
@ -245,145 +252,85 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
nblocks = kilobytes; nblocks = kilobytes;
if (nblocks != kilobytes) if (nblocks != kilobytes)
bb_error_msg_and_die("block count doesn't fit in 32 bits"); bb_error_msg_and_die("block count doesn't fit in 32 bits");
#define kilobytes kilobytes_unused_after_this
if (blocksize < PAGE_SIZE)
nblocks &= ~((PAGE_SIZE / blocksize)-1);
// N.B. killing e2fsprogs feature! Unused blocks don't account in calculations
nblocks_full = nblocks;
retry:
if (nblocks < 8) if (nblocks < 8)
bb_error_msg_and_die("need >= 8 blocks"); bb_error_msg_and_die("need >= 8 blocks");
#define kilobytes kilobytes_unused_after_this
// number of bits in one block, i.e. 8*blocksize // number of bits in one block, i.e. 8*blocksize
#define blocks_per_group (8 * blocksize) #define blocks_per_group (8 * blocksize)
/* e2fsprogs-1.41.9
overhead = 2 + fs->inode_blocks_per_group;
if (has_super(fs->group_desc_count - 1))
overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
rem = (nblocks - first_data_block) % blocks_per_group);
if ((fs->group_desc_count == 1) && rem && (rem < overhead)) {
retval = EXT2_ET_TOOSMALL;
goto cleanup;
}
if (rem && (rem < overhead+50)) {
nblocks -= rem;
goto retry;
}
*/
// N.B. a block group can have no more than blocks_per_group blocks // N.B. a block group can have no more than blocks_per_group blocks
first_data_block = (EXT2_MIN_BLOCK_SIZE == blocksize); first_data_block = (EXT2_MIN_BLOCK_SIZE == blocksize);
ngroups = div_roundup(nblocks - first_data_block, blocks_per_group); ngroups = div_roundup(nblocks - first_data_block, blocks_per_group);
if (0 == ngroups) if (0 == ngroups)
bb_error_msg_and_die("ngroups"); bb_error_msg_and_die("ngroups");
{ gdtsz = div_roundup(ngroups, blocksize / sizeof(*gd));
// ninodes is the total number of inodes (files) in the file system // TODO: reserved blocks must be marked as such in the bitmaps,
uint32_t ninodes = nblocks / (bytes_per_inode >> blocksize_log2); // or resulting filesystem is corrupt
if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
ninodes_per_group = div_roundup(ninodes, ngroups);
// minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
if (ninodes_per_group < 16)
ninodes_per_group = 16;
}
// 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
// TODO: 1/5 sanity checks
// TODO: 0/5 more verbose error messages
// 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: 3/5 dir_index?
// fill the superblock
sb = xzalloc(blocksize);
sb->s_rev_level = 1; // revision 1 filesystem
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 = 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
sb->s_first_data_block = first_data_block; // 0 or 1
// block and inode bitmaps occupy no more than one block, so maximum number of blocks is
sb->s_blocks_per_group = sb->s_frags_per_group = blocks_per_group;
timestamp = time(NULL);
sb->s_mkfs_time = sb->s_wtime = sb->s_lastcheck = timestamp;
sb->s_state = 1;
sb->s_creator_os = EXT2_OS_LINUX;
sb->s_checkinterval = 24*60*60 * 180; // 180 days
sb->s_errors = EXT2_ERRORS_DEFAULT;
sb->s_feature_compat = EXT2_FEATURE_COMPAT_SUPP
| (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
| (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
;
// e2fsprogs-1.41.9 doesn't like EXT2_FEATURE_INCOMPAT_WHITEOUT
sb->s_feature_incompat = EXT2_FEATURE_INCOMPAT_FILETYPE;// | EXT2_FEATURE_INCOMPAT_WHITEOUT;
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);
}
/*
* 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
* kludgy hack of using the UUID to derive a random jitter value.
*/
sb->s_max_mnt_count = EXT2_DFL_MAX_MNT_COUNT
+ (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT);
sb->s_blocks_count = nblocks;
// reserve blocks for superuser
sb->s_r_blocks_count = ((uint64_t) nblocks * nreserved) / 100;
gdtsz = div_roundup(ngroups, EXT2_DESC_PER_BLOCK(sb));
/*
* From e2fsprogs: Calculate the number of GDT blocks to reserve for online
* filesystem growth.
* The absolute maximum number of GDT blocks we can reserve is determined by
* the number of block pointers that can fit into a single block.
*/
/* We set it at 1024x the current filesystem size, or
* the upper block count limit (2^32), whichever is lower.
*/
if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) { if (ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT) {
/*
* From e2fsprogs: Calculate the number of GDT blocks to reserve for online
* filesystem growth.
* The absolute maximum number of GDT blocks we can reserve is determined by
* the number of block pointers that can fit into a single block.
* We set it at 1024x the current filesystem size, or
* the upper block count limit (2^32), whichever is lower.
*/
uint32_t rgdtsz = 0xFFFFFFFF; // maximum block number uint32_t rgdtsz = 0xFFFFFFFF; // maximum block number
if (nblocks < rgdtsz / 1024) if (nblocks < rgdtsz / 1024)
rgdtsz = nblocks * 1024; rgdtsz = nblocks * 1024;
rgdtsz = div_roundup(rgdtsz - first_data_block, blocks_per_group); rgdtsz = div_roundup(rgdtsz - first_data_block, blocks_per_group);
rgdtsz = div_roundup(rgdtsz, EXT2_DESC_PER_BLOCK(sb)) - gdtsz; rgdtsz = div_roundup(rgdtsz, blocksize / sizeof(*gd)) - gdtsz;
if (rgdtsz > EXT2_ADDR_PER_BLOCK(sb)) if (rgdtsz > blocksize / sizeof(uint32_t))
rgdtsz = EXT2_ADDR_PER_BLOCK(sb); rgdtsz = blocksize / sizeof(uint32_t);
STORE_LE(sb->s_reserved_gdt_blocks, rgdtsz); //TODO: STORE_LE(sb->s_reserved_gdt_blocks, rgdtsz);
gdtsz += rgdtsz; gdtsz += rgdtsz;
} }
// N.B. a block group can have no more than 8*blocksize inodes {
if (ninodes_per_group > blocks_per_group) // N.B. e2fsprogs does as follows!
ninodes_per_group = blocks_per_group; // ninodes is the total number of inodes (files) in the file system
// adjust inodes per group so they completely fill the inode table blocks in the descriptor uint32_t ninodes = nblocks_full / (blocksize >= 4096 ? 1 : 4096 / blocksize);
ninodes_per_group = (div_roundup(ninodes_per_group * EXT2_INODE_SIZE(sb), blocksize) << blocksize_log2) / EXT2_INODE_SIZE(sb); uint32_t overhead, remainder;
// make sure the number of inodes per group is a multiple of 8 if (ninodes < EXT2_GOOD_OLD_FIRST_INO+1)
ninodes_per_group &= ~7; ninodes = EXT2_GOOD_OLD_FIRST_INO+1;
sb->s_inodes_per_group = ninodes_per_group;// = div_roundup(ninodes_per_group * sb->s_inode_size, blocksize); inodes_per_group = div_roundup(ninodes, ngroups);
// total ninodes // minimum number because the first EXT2_GOOD_OLD_FIRST_INO-1 are reserved
sb->s_inodes_count = ninodes_per_group * ngroups; if (inodes_per_group < 16)
inodes_per_group = 16;
itsz = ninodes_per_group * sb->s_inode_size / blocksize; // N.B. a block group can have no more than 8*blocksize inodes
sb->s_free_inodes_count = sb->s_inodes_count - EXT2_GOOD_OLD_FIRST_INO; 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
inodes_per_group = (div_roundup(inodes_per_group * sizeof(*inode), blocksize) << blocksize_log2) / sizeof(*inode);
// make sure the number of inodes per group is a multiple of 8
inodes_per_group &= ~7;
itsz = div_roundup(inodes_per_group * sizeof(*inode), blocksize);
// write the label, if any // the last block needs more attention: doesn't it too small for possible overhead?
if (opts & OPT_L) overhead = (has_super(ngroups - 1) ? (1/*sb*/ + gdtsz) : 0) + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name)); remainder = (nblocks - first_data_block) % blocks_per_group;
if ((1 == ngroups) && remainder && (remainder < overhead))
#if 1 bb_error_msg_and_die("way small device");
/* if (fs_param.s_blocks_count != s->s_blocks_count) if (remainder && (remainder < overhead + 50)) {
fprintf(stderr, _("warning: %u blocks unused.\n\n"), //bb_info_msg("CHOP[%u]", remainder);
fs_param.s_blocks_count - s->s_blocks_count); nblocks -= remainder;
*/ goto retry;
}
}
// print info
if (nblocks_full - nblocks)
printf("warning: %u blocks unused\n\n", nblocks_full - nblocks);
printf( printf(
"Filesystem label=%s\n" "Filesystem label=%s\n"
"OS type: Linux\n" "OS type: Linux\n"
@ -396,16 +343,17 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
"%u block groups\n" "%u block groups\n"
"%u blocks per group, %u fragments per group\n" "%u blocks per group, %u fragments per group\n"
"%u inodes per group" "%u inodes per group"
, (char *)sb->s_volume_name , label
, blocksize, sb->s_log_block_size , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
, blocksize, sb->s_log_block_size , blocksize, blocksize_log2 - EXT2_MIN_BLOCK_LOG_SIZE
, sb->s_inodes_count, sb->s_blocks_count , inodes_per_group * ngroups, nblocks
, sb->s_r_blocks_count, nreserved //, div_roundup((uint64_t) nblocks * nreserved, 100), nreserved
, (unsigned)((uint64_t) nblocks_full * nreserved / 100), nreserved
, first_data_block , first_data_block
, gdtsz * EXT2_DESC_PER_BLOCK(sb) * blocks_per_group , gdtsz * (blocksize / sizeof(*gd)) * blocks_per_group
, ngroups , ngroups
, blocks_per_group, blocks_per_group , blocks_per_group, blocks_per_group
, ninodes_per_group , inodes_per_group
); );
{ {
const char *fmt = "\nSuperblock backups stored on blocks:\n" const char *fmt = "\nSuperblock backups stored on blocks:\n"
@ -420,84 +368,149 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
} }
} }
bb_putchar('\n'); bb_putchar('\n');
#endif
// dry run? -> we are done
if (opts & OPT_n) if (opts & OPT_n)
goto done; goto done;
// TODO: 3/5 refuse if mounted
// TODO: 4/5 compat options
// TODO: 1/5 sanity checks
// TODO: 0/5 more verbose error messages
// TODO: 4/5 bigendianness: recheck, wait for ARM reporters
// TODO: 2/5 reserved GDT: how to mark but not allocate?
// TODO: 3/5 dir_index?
// fill the superblock
sb = xzalloc(blocksize);
STORE_LE(sb->s_rev_level, 1); // revision 1 filesystem
STORE_LE(sb->s_magic, EXT2_SUPER_MAGIC);
STORE_LE(sb->s_inode_size, sizeof(*inode));
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);
// 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
STORE_LE(sb->s_first_data_block, first_data_block); // 0 or 1
// block and inode bitmaps occupy no more than one block, so maximum number of blocks is
STORE_LE(sb->s_blocks_per_group, blocks_per_group);
STORE_LE(sb->s_frags_per_group, blocks_per_group);
// blocks
STORE_LE(sb->s_blocks_count, nblocks);
// reserve blocks for superuser
STORE_LE(sb->s_r_blocks_count, (uint32_t)((uint64_t) nblocks_full * nreserved / 100));
// ninodes
STORE_LE(sb->s_inodes_per_group, inodes_per_group);
STORE_LE(sb->s_inodes_count, inodes_per_group * ngroups);
STORE_LE(sb->s_free_inodes_count, inodes_per_group * ngroups - EXT2_GOOD_OLD_FIRST_INO);
// timestamps
timestamp = time(NULL);
STORE_LE(sb->s_mkfs_time, timestamp);
STORE_LE(sb->s_wtime, timestamp);
STORE_LE(sb->s_lastcheck, timestamp);
// misc
STORE_LE(sb->s_state, 1); // TODO: what's 1?
STORE_LE(sb->s_creator_os, EXT2_OS_LINUX);
STORE_LE(sb->s_checkinterval, 24*60*60 * 180); // 180 days
STORE_LE(sb->s_errors, EXT2_ERRORS_DEFAULT);
STORE_LE(sb->s_feature_compat, EXT2_FEATURE_COMPAT_SUPP
| (EXT2_FEATURE_COMPAT_RESIZE_INO * ENABLE_FEATURE_MKFS_EXT2_RESERVED_GDT)
| (EXT2_FEATURE_COMPAT_DIR_INDEX * ENABLE_FEATURE_MKFS_EXT2_DIR_INDEX)
);
// e2fsprogs-1.41.9 doesn't like EXT2_FEATURE_INCOMPAT_WHITEOUT
STORE_LE(sb->s_feature_incompat, EXT2_FEATURE_INCOMPAT_FILETYPE);// | EXT2_FEATURE_INCOMPAT_WHITEOUT;
STORE_LE(sb->s_feature_ro_compat, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER);
STORE_LE(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) {
STORE_LE(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
* kludgy hack of using the UUID to derive a random jitter value.
*/
STORE_LE(sb->s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT
+ (sb->s_uuid[ARRAY_SIZE(sb->s_uuid)-1] % EXT2_DFL_MAX_MNT_COUNT));
// write the label, if any
if (label) //opts & OPT_L)
safe_strncpy((char *)sb->s_volume_name, label, sizeof(sb->s_volume_name));
// fill group descriptors // fill group descriptors
gd = xzalloc(gdtsz * blocksize); gd = xzalloc(gdtsz * blocksize);
buf = xmalloc(blocksize);
sb->s_free_blocks_count = 0; sb->s_free_blocks_count = 0;
for (i = 0, pos = first_data_block, n = nblocks; for (i = 0, pos = first_data_block, n = nblocks - first_data_block;
i < ngroups; i < ngroups;
i++, pos += blocks_per_group, n -= blocks_per_group i++, pos += blocks_per_group, n -= blocks_per_group
) { ) {
uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + gdtsz) : 0); uint32_t overhead = pos + (has_super(i) ? (1/*sb*/ + gdtsz) : 0);
gd[i].bg_block_bitmap = overhead + 0; uint32_t fb;
gd[i].bg_inode_bitmap = overhead + 1; STORE_LE(gd[i].bg_block_bitmap, overhead + 0);
gd[i].bg_inode_table = overhead + 2; STORE_LE(gd[i].bg_inode_bitmap, overhead + 1);
STORE_LE(gd[i].bg_inode_table, overhead + 2);
overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + itsz; overhead = overhead - pos + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
gd[i].bg_free_inodes_count = ninodes_per_group; gd[i].bg_free_inodes_count = inodes_per_group;
//gd[i].bg_used_dirs_count = 0; //STORE_LE(gd[i].bg_used_dirs_count, 0);
// N.B. both root and lost+found dirs are within the first block group, thus +2 // N.B. both root and lost+found dirs are within the first block group, thus +2
if (0 == i) { if (0 == i) {
overhead += 2; overhead += 2;
gd[i].bg_used_dirs_count = 2; STORE_LE(gd[i].bg_used_dirs_count, 2);
gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO; gd[i].bg_free_inodes_count -= EXT2_GOOD_OLD_FIRST_INO;
} }
// N.B. the following is pure heuristics! // // N.B. the following is pure heuristics!
// Likely to cope with 1024-byte blocks, when first block is for boot sectors // // Likely to cope with 1024-byte blocks, when first block is for boot sectors
if (ngroups-1 == i) { // if (ngroups-1 == i) {
overhead += first_data_block; // n -= first_data_block;
} // }
gd[i].bg_free_blocks_count = (n < blocks_per_group ? n : blocks_per_group) - overhead;
sb->s_free_blocks_count += gd[i].bg_free_blocks_count; // mark preallocated blocks as allocated
fb = (n < blocks_per_group ? n : blocks_per_group) - overhead;
//bb_info_msg("ALLOC: [%u][%u][%u]", blocksize, overhead, blocks_per_group - (fb + overhead));
allocate(buf, blocksize,
overhead,
blocks_per_group - (fb + overhead)
);
// dump block bitmap
PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
STORE_LE(gd[i].bg_free_blocks_count, fb);
// mark preallocated inodes as allocated
allocate(buf, blocksize,
inodes_per_group - gd[i].bg_free_inodes_count,
blocks_per_group - inodes_per_group
);
// dump inode bitmap
//PUT((uint64_t)(FETCH_LE32(gd[i].bg_block_bitmap)) * blocksize, buf, blocksize);
//but it's right after block bitmap, so we can just:
xwrite(fd, buf, blocksize);
STORE_LE(gd[i].bg_free_inodes_count, gd[i].bg_free_inodes_count);
// count overall free blocks
sb->s_free_blocks_count += fb;
} }
STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count); STORE_LE(sb->s_free_blocks_count, sb->s_free_blocks_count);
// dump filesystem skeleton structures // dump filesystem skeleton structures
// printf("Writing superblocks and filesystem accounting information: "); // printf("Writing superblocks and filesystem accounting information: ");
buf = xmalloc(blocksize);
for (i = 0, pos = first_data_block; i < ngroups; i++, pos += blocks_per_group) { for (i = 0, pos = first_data_block; i < ngroups; i++, pos += blocks_per_group) {
uint32_t overhead = has_super(i) ? (1/*sb*/ + gdtsz) : 0;
uint32_t start;
uint32_t end;
// dump superblock and group descriptors and their backups // 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 if (has_super(i)) {
// N.B. 1024 byte blocks are special // N.B. 1024 byte blocks are special
PUT(((uint64_t)pos << blocksize_log2) + ((0 == i && 0 == first_data_block) ? 1024 : 0), sb, 1024);//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 * blocksize); PUT(((uint64_t)pos << blocksize_log2) + blocksize, gd, gdtsz * blocksize);
} }
start = overhead + 1/*bbmp*/ + 1/*ibmp*/ + itsz;
if (i == 0)
start += 2; // for "/" and "/lost+found"
end = blocks_per_group - (start + gd[i].bg_free_blocks_count);
// mark preallocated blocks as allocated
allocate(buf, blocksize, start, end);
// dump block bitmap
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,
blocks_per_group - ninodes_per_group
);
// dump inode bitmap
//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 // zero boot sectors
memset(buf, 0, blocksize); memset(buf, 0, blocksize);
PUT(0, buf, 1024); // N.B. 1024 <= blocksize PUT(0, buf, 1024); // N.B. 1024 <= blocksize, so buf[0..1023] contains zeros
// zero inode tables // zero inode tables
for (i = 0; i < ngroups; ++i) for (i = 0; i < ngroups; ++i)
for (n = 0; n < itsz; ++n) for (n = 0; n < itsz; ++n)
PUT((uint64_t)(gd[i].bg_inode_table + n) * blocksize, buf, blocksize); PUT((uint64_t)(FETCH_LE32(gd[i].bg_inode_table) + n) * blocksize, buf, blocksize);
// prepare directory inode // prepare directory inode
inode = (struct ext2_inode *)buf; inode = (struct ext2_inode *)buf;
@ -511,13 +524,13 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
// dump root dir inode // dump root dir inode
STORE_LE(inode->i_links_count, 3); // "/.", "/..", "/lost+found/.." point to this 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); STORE_LE(inode->i_block[0], FETCH_LE32(gd[0].bg_inode_table) + itsz);
PUT(((uint64_t)gd[0].bg_inode_table << blocksize_log2) + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode)); PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) << blocksize_log2) + (EXT2_ROOT_INO-1) * sizeof(*inode), buf, sizeof(*inode));
// dump lost+found dir 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_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; STORE_LE(inode->i_block[0], inode->i_block[0]+1); // use next block
PUT(((uint64_t)gd[0].bg_inode_table << blocksize_log2) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode)); PUT(((uint64_t)FETCH_LE32(gd[0].bg_inode_table) << blocksize_log2) + (EXT2_GOOD_OLD_FIRST_INO-1) * sizeof(*inode), buf, sizeof(*inode));
// dump directories // dump directories
memset(buf, 0, blocksize); memset(buf, 0, blocksize);
@ -534,7 +547,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
STORE_LE(dir->name_len2, 2); STORE_LE(dir->name_len2, 2);
STORE_LE(dir->file_type2, EXT2_FT_DIR); STORE_LE(dir->file_type2, EXT2_FT_DIR);
dir->name2[0] = '.'; dir->name2[1] = '.'; dir->name2[0] = '.'; dir->name2[1] = '.';
PUT((uint64_t)(gd[0].bg_inode_table + itsz + 1) * blocksize, buf, blocksize); PUT((uint64_t)(FETCH_LE32(gd[0].bg_inode_table) + itsz + 1) * blocksize, buf, blocksize);
// dump root dir block // dump root dir block
STORE_LE(dir->inode1, EXT2_ROOT_INO); STORE_LE(dir->inode1, EXT2_ROOT_INO);
@ -544,13 +557,7 @@ int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv)
STORE_LE(dir->name_len3, 10); STORE_LE(dir->name_len3, 10);
STORE_LE(dir->file_type3, EXT2_FT_DIR); STORE_LE(dir->file_type3, EXT2_FT_DIR);
strcpy(dir->name3, "lost+found"); strcpy(dir->name3, "lost+found");
PUT((uint64_t)(gd[0].bg_inode_table + itsz + 0) * blocksize, buf, blocksize); PUT((uint64_t)(FETCH_LE32(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"
// "180 days, whichever comes first. Use tune2fs -c or -i to override.",
// sb->s_max_mnt_count
// );
done: done:
// cleanup // cleanup

91
util-linux/mkfs_ext2_test.sh
View File

@ -1,54 +1,71 @@
#!/bin/sh #!/bin/sh
run_test() { # params: mke2fs_invocation image_name
>$2
dd seek=$((kilobytes-1)) bs=1K count=1 </dev/zero of=$2 >/dev/null 2>&1 || exit 1
$1 -F $2 $kilobytes >$2.raw_out 2>&1 || return 1
cat $2.raw_out \
| grep -v '^mke2fs [0-9]*\.[0-9]*\.[0-9]* ' \
| grep -v '^Maximum filesystem' \
| grep -v '^Writing inode tables' \
| grep -v '^Writing superblocks and filesystem accounting information' \
| grep -v '^This filesystem will be automatically checked every' \
| grep -v '^180 days, whichever comes first' \
| sed 's/inodes, [0-9]* blocks/inodes, N blocks/' \
| sed 's/blocks* unused./blocks unused/' \
| sed 's/block groups*/block groups/' \
| sed 's/ *$//' \
| sed 's/blocks (.*%) reserved/blocks reserved/' \
| grep -v '^$' \
>$2.out
}
test_mke2fs() { test_mke2fs() {
echo Testing $kilobytes echo Testing $kilobytes
>image_std run_test '/usr/bin/mke2fs' image_std || return 1
dd seek=$((kilobytes-1)) bs=1K count=1 </dev/zero of=image_std >/dev/null 2>&1 || exit 1 run_test './busybox mke2fs' image_bb || return 1
/usr/bin/mke2fs -F image_std $kilobytes >image_std.raw_out 2>&1 || return 1
cat image_std.raw_out \
| grep -v '^mke2fs ' \
| grep -v '^Maximum filesystem' \
| grep -v '^warning: .* blocks unused' \
| grep -v '^Writing inode tables' \
| grep -v '^Writing superblocks and filesystem accounting information' \
| grep -v '^This filesystem will be automatically checked every' \
| grep -v '^180 days, whichever comes first' \
| sed 's/block groups/block group/' \
| sed 's/ *$//' \
| sed 's/blocks (.*%) reserved/blocks reserved/' \
| grep -v '^$' \
>image_std.out
>image_bb
dd seek=$((kilobytes-1)) bs=1K count=1 </dev/zero of=image_bb >/dev/null 2>&1 || exit 1
./busybox mke2fs -F image_bb $kilobytes >image_bb.raw_out 2>&1 || return 1
cat image_bb.raw_out \
| grep -v '^mke2fs ' \
| grep -v '^Maximum filesystem' \
| grep -v '^warning: .* blocks unused' \
| grep -v '^Writing inode tables' \
| grep -v '^Writing superblocks and filesystem accounting information' \
| grep -v '^This filesystem will be automatically checked every' \
| grep -v '^180 days, whichever comes first' \
| sed 's/block groups/block group/' \
| sed 's/ *$//' \
| sed 's/blocks (.*%) reserved/blocks reserved/' \
| grep -v '^$' \
>image_bb.out
diff -ua image_bb.out image_std.out >image.out.diff || { diff -ua image_bb.out image_std.out >image.out.diff || {
cat image.out.diff cat image.out.diff
return 1 return 1
} }
e2fsck -f -n image_bb >/dev/null 2>&1 || { echo "e2fsck error on image_bb"; exit 1; }
} }
# -:bbox +:standard
# -6240 inodes, 24908 blocks
# +6240 inodes, 24577 blocks
# -4 block group
# +3 block group
# -1560 inodes per group
# +2080 inodes per group
kilobytes=24908 test_mke2fs kilobytes=24908 test_mke2fs
kilobytes=81940 test_mke2fs
kilobytes=98392 test_mke2fs # -304 inodes, N blocks
exit # +152 inodes, N blocks
# -304 inodes per group
# +152 inodes per group
kilobytes=1218 test_mke2fs
# -14464 inodes, N blocks
# +14448 inodes, N blocks
# -8 block group
# +7 block group
# -1808 inodes per group
# +2064 inodes per group
kilobytes=57696 test_mke2fs
# This size results in "warning: 75 blocks unused"
kilobytes=98380 test_mke2fs
# -warning: 239 blocks unused.
# +warning: 242 blocks unused.
kilobytes=49395 test_mke2fs
while true; do while true; do
kilobytes=$(( (RANDOM*RANDOM) % 100000 + 100)) kilobytes=$(( (RANDOM*RANDOM) % 1000000 + 2000))
test_mke2fs || exit 1 test_mke2fs || exit 1
done done