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ext2.c
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typedef struct
{
char* address;
} DISK_MEMORY;
#include "ext2.h"
#include "ext2_shell.h"
#include "ext2_indirect.h"
#define MIN( a, b ) ( ( a ) < ( b ) ? ( a ) : ( b ) )
#define MAX( a, b ) ( ( a ) > ( b ) ? ( a ) : ( b ) )
#define GET_RECORD_LEN(entry) ((entry)->name_len + 8)
// 임시 expand
UINT32 expand_block_scope(EXT2_FILESYSTEM * fs, UINT32 inode_num, DWORD start, DWORD end, UINT32 prefer_group, UINT32 is_dir)
{
INODE *inode_buf;
EXT2_ENTRY_LOCATION loc;
UINT32 i_blk_idx, new_block;
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
get_inode_location(fs, inode_num, &loc);
read_disk_per_block(fs, loc.group, loc.block, block);
inode_buf = ((INODE *)block) + loc.offset;
if (start > end || start < 0 || 15 <= end) return EXT2_ERROR;
// 간접 i_block 추가구현 해야함 일단 고려 안하고 짬
for (i_blk_idx = start; i_blk_idx <= end; i_blk_idx++) {
if (inode_buf->i_block[i_blk_idx] == 0)
break;
}
if (i_blk_idx == 15) {
printf("i_blocks full\n");
return EXT2_ERROR;
}
// group 임시로 0으로 해놓음 수정해야함
new_block = alloc_free_data_block_in_group(fs, 0);
if (new_block == -1) {
printf("alloc block error\n");
return EXT2_ERROR;
}
inode_buf->block_cnt++;
inode_buf->i_block[i_blk_idx] = new_block;
write_disk_per_block(fs, loc.group, loc.block, block);
ZeroMemory(block, sizeof(block));
if (is_dir == EXT2_FT_DIR)
{
((EXT2_DIR_ENTRY *)block)->record_len = (MAX_SECTOR_SIZE * SECTOR_PER_BLOCK);
}
get_block_location(fs, new_block, &loc);
write_disk_per_block(fs, loc.group, loc.block, block);
return EXT2_SUCCESS;
}
#define FILL_ENTRY(entry, _inode, _name, _type) \
(entry)->inode = _inode; \
(entry)->file_type = _type; \
(entry)->name_len = strlen(_name); \
memcpy((entry)->name, _name, (entry)->name_len); \
(entry)->record_len = GET_RECORD_LEN((entry))
int ext2_write(EXT2_NODE* file, unsigned long offset, unsigned long length, const char* buffer)
{
DWORD current_offset, current_block;
DWORD block_number; // 실제 블록 넘버말고 논리적인 블록 순서
DWORD start_block_number;
DWORD read_end;
DWORD block_offset = 0;
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
UINT32 byte_per_block = 1024 << LOG_BLOCK_SIZE; // MAX_SECTOR_SIZE * SECTOR_PER_BLOCK
EXT2_DIR_ENTRY *entry = &file->entry;
INODE *inode_ptr;
EXT2_ENTRY_LOCATION loc;
read_end = offset + length;
current_offset = offset;
start_block_number = offset / byte_per_block;
block_number = read_end / byte_per_block;
// start_block_number 에서부터 block_number까지 할당 안돼있으면 할당해줘야함.
for (int i = start_block_number ; i <= block_number ; i++)
{
// 나중에 0 수정할 것.
/*if (expand_block(file->fs, entry->inode, 0, EXT2_FT_UNKNOWN) == EXT2_ERROR)
{
printf("Can't expand block.\n");
return EXT2_ERROR;
}*/
// 임시
expand_block_scope(file->fs, entry->inode, start_block_number, block_number, 0, EXT2_FT_REG_FILE);
//get_inode(file->fs, entry->inode, &inode_ptr); // 이거 나중에 이 줄 없애게 수정?
}
while (current_offset < read_end)
{
DWORD copy_length;
current_block = current_offset / byte_per_block;
block_offset = current_offset % byte_per_block;
copy_length = MIN(byte_per_block - block_offset, read_end - current_offset);
// 어쨋든 block 읽어와서 copy_length만큼 쓴 다음 그거 write
if (read_data_by_logical_block_num(file->fs, entry->inode, current_block, block) == EXT2_ERROR)
{
printf("read_data_by_logical_block_num() function error.\n");
return EXT2_ERROR;
}
memcpy(&block[block_offset], buffer, copy_length);
if( write_data_by_logical_block_num(file->fs, entry->inode, current_block, block) == EXT2_ERROR)
{
printf("write_data_by_logical_block_num() function error.\n");
return EXT2_ERROR;
}
get_inode_location(file->fs, entry->inode, &loc);
read_disk_per_block(file->fs, loc.group, loc.block, block); // block 버퍼 재활용
inode_ptr = ((INODE*)block) + loc.offset;
inode_ptr->size += copy_length;
buffer += copy_length;
current_offset += copy_length;
}
write_disk_per_block(file->fs, loc.group, loc.block, block);
return current_offset - offset;
}
int ext2_read(EXT2_NODE* file, unsigned long offset, unsigned long length, const char* buffer)
{
DWORD current_offset;
DWORD block_number; // 실제 블록 넘버말고 논리적인 블록 순서
DWORD read_end;
DWORD block_offset = 0;
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
UINT32 byte_per_block = 1024 << LOG_BLOCK_SIZE;
EXT2_DIR_ENTRY *entry = &file->entry;
INODE inode;
int i_block_index;
get_inode(file->fs, entry->inode, &inode);
read_end = MIN(offset + length, inode.size);
current_offset = offset;
block_number = offset / byte_per_block;
while (current_offset < read_end)
{
DWORD copy_length;
block_number = current_offset / byte_per_block;
block_offset = current_offset % byte_per_block;
// block_number 에 따라서 data block 가져오기
if (read_data_by_logical_block_num(file->fs, entry->inode, block_number , block) == EXT2_ERROR)
{
printf("read_data_by_logical_block_num() function error.\n");
return EXT2_ERROR;
}
copy_length = MIN(byte_per_block - block_offset, read_end - current_offset);
memcpy(buffer, &block[block_offset], copy_length);
buffer += copy_length;
current_offset += copy_length;
}
return current_offset - offset;
}
// file이 차지하는 블록의 논리적 순서에 위치한 블록의 i_block_index구함
int get_i_block_index_by_logical_block_num(int block_number)
{
UINT32 i_block_index;
if (0<=block_number && block_number < 12)
i_block_index = block_number;
else if (12 <= block_number && block_number < 12 + 256)
i_block_index = 12;
else if (12 + 256 <= block_number && block_number < 12 + 256 + 256*256)
i_block_index = 13;
else if (12 + 256 + 256*256 <= block_number && block_number < 12 + 256 + 256*256 + 256*256*256)
i_block_index = 14;
return i_block_index;
}
int read_data_by_logical_block_num(EXT2_FILESYSTEM* fs, const int inode_num, UINT32 logical_block_num , BYTE* block_buf)
{
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
INODE inode;
UINT32 byte_per_block = 1024 << LOG_BLOCK_SIZE;
UINT32 i_block_index = logical_block_num;
get_inode(fs, inode_num, &inode);
i_block_index = get_i_block_index_by_logical_block_num(logical_block_num);
if (i_block_index < 0 || 15 <= i_block_index)
{
return EXT2_ERROR;
}
// inode.i_block[i_block_index] 번째 block, block 버퍼에 저장
UINT32 block_num = inode.i_block[i_block_index];
EXT2_ENTRY_LOCATION loc;
get_block_location(fs, block_num, &loc);
if (!inode.i_block[i_block_index])
{
printf("그런 블록 또 없습니다~\n"); // 나중에 삭제
return EXT2_ERROR;
}
if (i_block_index < 12)
{
read_disk_per_block(fs, loc.group, loc.block, block_buf);
return EXT2_SUCCESS;
}
else if (i_block_index >= 12) // 뒤에 아직 구현 대충
{
int block_offset_1, block_offset_2, block_offset_3;
int file_block, file_block_2, file_block_3;
int max_block_offset = byte_per_block / sizeof(int *); // 256
read_disk_per_block(fs, loc.group, loc.block, block);
switch(i_block_index)
{
case 12: // 단일 간접
block_offset_1 = logical_block_num - 12;
*((int *)block + block_offset_1) = file_block;
get_block_location(fs, file_block, &loc);
read_disk_per_block(fs, loc.group, loc.block, block_buf);
return EXT2_SUCCESS;
case 13: // 이중 간접
block_offset_2 = (logical_block_num - max_block_offset - 12) / max_block_offset;
block_offset_1 = (logical_block_num - max_block_offset - 12) % max_block_offset;
*((int *)block + block_offset_2) = file_block_2;
get_block_location(fs, file_block_2, &loc);
read_disk_per_block(fs, loc.group, loc.block, block);
*((int *)block + block_offset_1) = file_block;
get_block_location(fs, file_block, &loc);
read_disk_per_block(fs, loc.group, loc.block, block_buf);
return EXT2_SUCCESS;
case 14: // 삼중 간접
block_offset_3 = (logical_block_num - max_block_offset*max_block_offset - max_block_offset - 12) / (max_block_offset*max_block_offset);
block_offset_2 = (logical_block_num - max_block_offset*max_block_offset - max_block_offset - 12) / max_block_offset;
block_offset_1 = (logical_block_num - max_block_offset - 12) % max_block_offset;
*((int *)block + block_offset_3 ) = file_block_3;
get_block_location(fs, file_block_3, &loc);
read_disk_per_block(fs, loc.group, loc.block, block);
*((int *)block + block_offset_2 ) = file_block_2;
get_block_location(fs, file_block_2, &loc);
read_disk_per_block(fs, loc.group, loc.block, block);
*((int *)block + block_offset_1 ) = file_block;
get_block_location(fs, file_block, &loc);
read_disk_per_block(fs, loc.group, loc.block, block_buf);
return EXT2_SUCCESS;
} // switch문 종료
}
return EXT2_ERROR;
}
int write_data_by_logical_block_num(EXT2_FILESYSTEM* fs, const int inode_num, UINT32 logical_block_num , BYTE* block_buf)
{
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
INODE inode;
UINT32 byte_per_block = 1024 << LOG_BLOCK_SIZE;
UINT32 i_block_index = logical_block_num;
get_inode(fs, inode_num, &inode);
i_block_index = get_i_block_index_by_logical_block_num(logical_block_num);
// inode.i_block[i_block_index] 번째 block, block 버퍼에 저장
UINT32 block_num = inode.i_block[i_block_index];
EXT2_ENTRY_LOCATION loc;
get_block_location(fs, block_num, &loc);
if (!inode.i_block[i_block_index])
{
printf("그런 블록 또 없습니다~\n"); //나중에 삭제
return EXT2_ERROR;
}
if (i_block_index < 12)
{
write_disk_per_block(fs, loc.group, loc.block, block_buf);
return EXT2_SUCCESS;
}
else if (i_block_index >= 12) // 뒤에 구현 대충 함
{
int block_offset_1, block_offset_2, block_offset_3;
int max_block_offset = byte_per_block / sizeof(int *);
BYTE file_block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
BYTE file_block_2[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
BYTE file_block_3[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
read_disk_per_block(fs, loc.group, loc.block, block);
switch(i_block_index)
{
case 12: // 단일 간접
block_offset_1 = logical_block_num - 12;
*((int *)block + block_offset_1) = file_block;
get_block_location(fs, file_block, &loc);
write_disk_per_block(fs, loc.group, loc.block, block);
return EXT2_SUCCESS;
case 13: // 이중 간접
block_offset_2 = (logical_block_num - max_block_offset - 12) / max_block_offset;
block_offset_1 = (logical_block_num - max_block_offset - 12) % max_block_offset;
*((int *)block + block_offset_2) = file_block_2;
get_block_location(fs, file_block_2, &loc);
read_disk_per_block(fs, loc.group, loc.block, block);
*((int *)block + block_offset_1) = file_block;
get_block_location(fs, file_block, &loc);
write_disk_per_block(fs, loc.group, loc.block, block_buf);
return EXT2_SUCCESS;
case 14: // 삼중 간접
block_offset_3 = (logical_block_num - max_block_offset*max_block_offset - max_block_offset - 12) / (max_block_offset*max_block_offset);
block_offset_2 = (logical_block_num - max_block_offset*max_block_offset - max_block_offset - 12) / max_block_offset;
block_offset_1 = (logical_block_num - max_block_offset - 12) % max_block_offset;
*((int *)block + block_offset_3 ) = file_block_3;
get_block_location(fs, file_block_3, &loc);
read_disk_per_block(fs, loc.group, loc.block, block);
*((int *)block + block_offset_2 ) = file_block_2;
get_block_location(fs, file_block_2, &loc);
read_disk_per_block(fs, loc.group, loc.block, block);
*((int *)block + block_offset_1 ) = file_block;
get_block_location(fs, file_block, &loc);
write_disk_per_block(fs, loc.group, loc.block, block_buf);
return EXT2_SUCCESS;
} // switch문 종료
}
return EXT2_ERROR;
}
UINT32 get_free_inode_number(EXT2_FILESYSTEM* fs);
int write_block(DISK_OPERATIONS* disk, EXT2_SUPER_BLOCK* sb, BYTE* block, unsigned int start_block)
{
SECTOR sector_index = start_block * sb->sector_per_block + BOOT_SECTOR_BASE;
for (int i = 0; i < sb->sector_per_block; i++)
{
if (disk->write_sector(disk, sector_index + i, &(block[i * disk->bytes_per_sector])) == EXT2_ERROR) {
PRINTF("write_block() function error\n");
return EXT2_ERROR;
}
}
return EXT2_SUCCESS;
}
int read_block(DISK_OPERATIONS* disk, EXT2_SUPER_BLOCK* sb, BYTE* block, unsigned int start_block)
{
SECTOR sector_index = start_block * sb->sector_per_block + BOOT_SECTOR_BASE;
for (int i = 0; i < sb->sector_per_block; i++)
{
if(disk->read_sector(disk, sector_index + i, &(block[i * disk->bytes_per_sector]))== EXT2_ERROR) {
PRINTF("read_block() function error\n");
return EXT2_ERROR;
}
}
return EXT2_SUCCESS;
}
// 나중에 수정 : log_block_size는 define해줬으니까 삭제 해야함.
int ext2_format(DISK_OPERATIONS* disk, UINT32 log_block_size)
{
EXT2_SUPER_BLOCK sb;
EXT2_GROUP_DESCRIPTOR gd;
EXT2_GROUP_DESCRIPTOR gd_another_group;
int i, gi, j;
/* super block 채우기 */
if (fill_super_block(&sb, disk->number_of_sectors, disk->bytes_per_sector) != EXT2_SUCCESS)
return EXT2_ERROR;
UINT32 byte_per_block = 1024 << log_block_size;
UINT32 number_of_group = disk->number_of_sectors / (sb.sector_per_block * sb.block_per_group);
//BYTE block[MAX_SECTOR_SIZE * sector_per_block];
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
ZeroMemory(block, sizeof(block));
memcpy(block, &sb, sizeof(sb));
if (write_block(disk, &sb, block, 0) == EXT2_ERROR)
return EXT2_ERROR;
/* 0번 descriptor 채우기 */
if (fill_descriptor_block(&gd, &sb, disk->number_of_sectors, disk->bytes_per_sector) != EXT2_SUCCESS)
return EXT2_ERROR;
/* descriptor table 채우기 */
// 0번 block group과 달리, 1번~ block groups는 inode 예약 영역이 없고,
// root block이 없어서 free count 다시 초기화
UINT32 descriptor_per_block = (1024 << sb.log_block_size) / 32;
int descriptor_block_index = 0;
gd_another_group = gd;
gd_another_group.free_inodes_count = sb.inode_per_group;
gd_another_group.free_blocks_count = sb.free_block_count / number_of_group;
ZeroMemory(block, sizeof(block));
for (j = 0; j < number_of_group; j++)
{
if (j == 0) memcpy(block + j * sizeof(gd), &gd, sizeof(gd));
else memcpy(block + j * sizeof(gd_another_group), &gd_another_group, sizeof(gd_another_group));
// 한 block 꽉 차면 다음 block으로 넘어감
if ((j + 1) % descriptor_per_block == 0)
{
if (write_block(disk, &sb, block, 1 + descriptor_block_index++) == EXT2_ERROR)
return EXT2_ERROR;
ZeroMemory(block, sizeof(block));
}
}
// 꽉 채우지 못한 마지막 block 써줌
if (number_of_group % descriptor_per_block != 0)
{
if (write_block(disk, &sb, block, 1 + descriptor_block_index) == EXT2_ERROR)
return EXT2_ERROR;
}
/* block bitmap 채우기 */
ZeroMemory((block), sizeof(block));
for (unsigned int i = 0; i < sb.first_meta_bg + 1; i++) {
(((volatile unsigned int *) block)[i >> 5]) |= (1UL << (i & 31));
}
if (write_block(disk, &sb, block, gd.start_block_of_block_bitmap) == EXT2_ERROR)
return EXT2_ERROR;
/* inode bitmap 채우기 */
ZeroMemory(block, sizeof(block));
block[0] = 0xff; // 8개
block[1] = 0x03; // 2개 inode 예약 영역 10개 잡아줌
if (write_block(disk, &sb, block, gd.start_block_of_inode_bitmap) == EXT2_ERROR)
return EXT2_ERROR;
/* inode table 채우기 */
ZeroMemory(block, sizeof(block));
for (i = gd.start_block_of_inode_table; i < sb.first_meta_bg; i++)
{
if (write_block(disk, &sb, block, i) == EXT2_ERROR)
return EXT2_ERROR;
}
/* 1번째 block group부터 차례로 super block ~ inode table 채움 */
for (gi = 1; gi < number_of_group; gi++)
{
sb.block_group_num = gi;
/* gi번째 group에 super block 채우기 */
ZeroMemory(block, sizeof(block));
memcpy(block, &sb, sizeof(sb));
if (write_block(disk, &sb, block, sb.block_per_group * gi) == EXT2_ERROR)
return EXT2_ERROR;
/* gi번째 group에 descriptor table 채우기 */
ZeroMemory(block, sizeof(block));
descriptor_block_index = 0;
for (j = 0; j < number_of_group; j++)
{
if (j == 0) memcpy(block + j * sizeof(gd), &gd, sizeof(gd));
else memcpy(block + j * sizeof(gd_another_group), &gd_another_group, sizeof(gd_another_group));
// 한 block 꽉 차면 다음 block으로 넘어감
if ((j + 1) % descriptor_per_block == 0)
{
if (write_block(disk, &sb, block, sb.block_per_group * gi + 1 + descriptor_block_index++) == EXT2_ERROR)
return EXT2_ERROR;
ZeroMemory(block, sizeof(block));
}
}
// 꽉 채우지 못한 마지막 block 써줌
if (number_of_group % descriptor_per_block != 0)
{
if (write_block(disk, &sb, block, sb.block_per_group * gi + 1 + descriptor_block_index) == EXT2_ERROR)
return EXT2_ERROR;
}
/* gi번째 group에 block bitmap 채우기 */
ZeroMemory(block, sizeof(block));
for (unsigned int i = 0; i < sb.first_meta_bg; i++) {
(((volatile unsigned int *) block)[i >> 5]) |= (1UL << (i & 31));
}
if (write_block(disk, &sb, block, sb.block_per_group * gi + gd.start_block_of_block_bitmap) == EXT2_ERROR)
return EXT2_ERROR;
/* gi번째 group에 inode bitmap 채우기 */
ZeroMemory(block, sizeof(block));
if (write_block(disk, &sb, block, sb.block_per_group * gi + gd.start_block_of_inode_bitmap) == EXT2_ERROR)
return EXT2_ERROR;
/* gi번째 group에 inode table 채우기 */
ZeroMemory(block, sizeof(block));
for (i = sb.block_per_group * gi + gd.start_block_of_inode_table; i < sb.block_per_group * gi + sb.first_meta_bg; i++)
{
if (write_block(disk, &sb, block, i) == EXT2_ERROR)
return EXT2_ERROR;
}
}
PRINTF("max inode count : %u\n", sb.max_inode_count);
PRINTF("total block count : %u\n", sb.block_count);
PRINTF("byte size of inode : %u\n", sb.inode_size);
PRINTF("block byte size : %u\n", byte_per_block);
PRINTF("total sectors count : %u\n", disk->number_of_sectors);
PRINTF("sector byte size : %u\n", MAX_SECTOR_SIZE);
PRINTF("sector per block : %u\n", sb.sector_per_block);
PRINTF("number of group : %u\n", number_of_group);
PRINTF("inode per group : %u\n", sb.inode_per_group);
PRINTF("block per group : %u\n", sb.block_per_group);
PRINTF("\n");
if (create_root(disk, &sb, &gd) != EXT2_SUCCESS)
{
PRINTF("create_root() function error\n");
return EXT2_ERROR;
}
return EXT2_SUCCESS;
}
int fill_super_block(EXT2_SUPER_BLOCK * sb, SECTOR numberOfSectors, UINT32 bytesPerSector)
{
UINT32 byte_per_block = 1024 << LOG_BLOCK_SIZE;
UINT32 block_per_group = byte_per_block << 3;
BYTE sector_per_block = byte_per_block / bytesPerSector;
UINT32 number_of_group = (numberOfSectors + (sector_per_block * block_per_group - 1)) / (sector_per_block * block_per_group);
UINT32 number_of_descriptor_block = ( number_of_group * 32 + ( byte_per_block - 1 ) ) / byte_per_block;
UINT32 inode_per_block = 1 << (3 + LOG_BLOCK_SIZE);
UINT32 max_inode_count = numberOfSectors / sector_per_block / 2;
UINT32 inode_per_group = max_inode_count / number_of_group;
UINT32 number_of_inode_block = (inode_per_group + (inode_per_block - 1)) / inode_per_block; // 한 그룹에서 inode table이 차지하는 block 수
UINT32 number_of_used_block = number_of_descriptor_block + number_of_inode_block + 3; // 3 : super block + block bitmap + inode bitmap
ZeroMemory(sb, sizeof(EXT2_SUPER_BLOCK));
// max_inode_count = block 개수 / 2로 약속
sb->max_inode_count = max_inode_count;
sb->block_count = numberOfSectors / sector_per_block;
sb->reserved_block_count = (UINT32)( (double)sb->block_count * (5./100.) );
// 전체 block group에서 free한 block, inode의 개수
sb->free_block_count = sb->block_count - number_of_used_block * number_of_group - 1; // 1 : root
sb->free_inode_count = sb->max_inode_count - 10; // 10 : 예약된 inode
// 첫 번째 블록
sb->first_data_block = 0x00;
sb->log_block_size = LOG_BLOCK_SIZE; // 0, 1, 2
sb->log_fragmentation_size = 2; // 0, 1, 2 (2 - 임시)
sb->block_per_group = block_per_group;
// sb->fragmentation_per_group;
sb->inode_per_group = inode_per_group;
// 0
// sb->mtime;
// sb->wtime;
sb->mount_cnt = 0;
sb->max_mount_cnt = 0xFFFF;
sb->magic_signature = 0xEF53;
sb->state = 1;
sb->errors = 0;
// 0
// sb->minor_version;
// sb->last_check;
sb->check_interval = 0;
sb->creator_OS = 0; // linux
sb->major_version = 0; // inode 크기 고정
// 0
// sb->def_res_uid;
// sb->def_res_gid;
sb->first_ino = 11;
sb->inode_size = 128;
sb->block_group_num = 0;
// 책에 있는 것 그대로
sb->feature_compat = 0x24;
sb->feature_incompat = 0x02 ;
sb->feature_read_only_compat = 0x01;
// 0
// sb->uuid[16];
// sb->volume_name[16];
// sb->last_mounted[64];
// sb->algorithm_usage_bitmap;
// sb->prealloc_block;
// sb->prealloc_dir_block;
// sb->padding_1;
// sb->journal_uuid[16];
// sb->journal_inode_num;
// sb->journal_dev;
// sb->last_orphan;
// sb->hash_seed[16];
// sb->def_hash_version;
sb->sector_per_block = sector_per_block;
// 0
// sb->padding_3;
// sb->default_mount_opt;
sb->first_meta_bg = number_of_used_block; // 그룹내에서 meta block 이전까지의 블록의 개수
return EXT2_SUCCESS;
}
int fill_descriptor_block(EXT2_GROUP_DESCRIPTOR * gd, EXT2_SUPER_BLOCK * sb, SECTOR numberOfSectors, UINT32 bytesPerSector)
{
UINT32 byte_per_block = 1024 << sb->log_block_size;
UINT32 number_of_group = numberOfSectors / (sb->sector_per_block * sb->block_per_group);
UINT32 number_of_descriptor_block = ( number_of_group * 32 + (byte_per_block - 1)) / byte_per_block;
ZeroMemory(gd, sizeof(EXT2_GROUP_DESCRIPTOR));
gd->start_block_of_block_bitmap = number_of_descriptor_block + 1;
gd->start_block_of_inode_bitmap = gd->start_block_of_block_bitmap + 1;
gd->start_block_of_inode_table = gd->start_block_of_inode_bitmap + 1;
gd->free_blocks_count = (sb->free_block_count + 1) / number_of_group ;
gd->free_inodes_count = sb->inode_per_group - 10;
gd->directories_count = 0; // Block Group 내에 생성된 디렉토리 수
// 0
// gd->padding[2];
// gd->reserved[12];
return EXT2_SUCCESS;
}
int create_root(DISK_OPERATIONS* disk, EXT2_SUPER_BLOCK * sb, EXT2_GROUP_DESCRIPTOR *gd)
{
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
UINT32 block_bitmap_block = gd->start_block_of_block_bitmap;
UINT32 inode_table_block = gd->start_block_of_inode_table;
UINT32 root_entry_block = sb->first_meta_bg;
// set inode
ZeroMemory(block, sizeof(block));
INODE *root_inode = (INODE *)block; // 2번 inode
root_inode++;
root_inode->mode = 0x41ed; // directory, 755
root_inode->link_cnt = 2; // ".", ".."
root_inode->block_cnt = 1;
root_inode->size = MAX_SECTOR_SIZE * SECTOR_PER_BLOCK;
root_inode->i_block[0] = root_entry_block;
write_block(disk, sb, block, inode_table_block);
//dump_block(disk, sb, inode_table_block);
// set dir_entry
// "." entry
ZeroMemory(block, sizeof(block));
EXT2_DIR_ENTRY *entry = (EXT2_DIR_ENTRY *)block;
FILL_ENTRY(entry, 2, ".", EXT2_FT_DIR);
// ".." entry
EXT2_DIR_ENTRY *prev_entry = entry;
entry = (EXT2_DIR_ENTRY *)(block + prev_entry->record_len);
FILL_ENTRY(entry, 2, "..", EXT2_FT_DIR);
entry->record_len = (1024 << sb->log_block_size) - prev_entry->record_len;
write_block(disk, sb, block, root_entry_block);
return EXT2_SUCCESS;
}
int insert_entry(UINT32 inode_num, EXT2_NODE * retEntry)
{
EXT2_NODE new_entry;
new_entry.fs = retEntry->fs;
new_entry.entry.name_len = retEntry->entry.name_len;
// 새로운 entry가 들어가는 위치의 바로 앞에 있는 entry 위치정보를 new_entry->loc에 저장
if (lookup_entry(retEntry->fs, inode_num, NULL, &new_entry) == EXT2_SUCCESS)
{
retEntry->location = new_entry.location;
set_entry(retEntry->fs, &new_entry.location, &retEntry->entry);
}
else // lookup_entry에서 빈자리 못찾았으면 오류
{
return EXT2_ERROR;
}
return EXT2_SUCCESS;
}
int set_entry(EXT2_FILESYSTEM * fs, EXT2_ENTRY_LOCATION *loc, EXT2_DIR_ENTRY *new_entry)
{
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
BYTE *block_offset;
EXT2_DIR_ENTRY *entry;
UINT32 new_record_len;
read_disk_per_block(fs, loc->group, loc->block, block);
block_offset = block + loc->offset;
// entry의 record_len 수정
entry = (EXT2_DIR_ENTRY *)block_offset;
if (loc->offset == 0 && GET_RECORD_LEN(entry) == 8) // mkdir할 때 첫 entry
{
new_entry->record_len = entry->record_len;
memcpy(entry, new_entry, GET_RECORD_LEN(new_entry));
}
else
{
new_record_len = entry->record_len - GET_RECORD_LEN(entry);
entry->record_len = GET_RECORD_LEN(entry);
// new entry의 record_len 수정한 뒤에 블럭에 추가
block_offset += entry->record_len;
entry = (EXT2_DIR_ENTRY *)block_offset;
new_entry->record_len = new_record_len;
memcpy(entry, new_entry, GET_RECORD_LEN(new_entry));
}
write_disk_per_block(fs, loc->group, loc->block, block);
return EXT2_SUCCESS;
}
int set_new_inode(EXT2_FILESYSTEM *fs, UINT32 prefer_group, UINT32 is_dir)
{
INODE *inode_ptr;
EXT2_ENTRY_LOCATION loc;
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
UINT32 new_inode;
new_inode = alloc_free_inode_in_group(fs, 0);
if (new_inode == -1){
printf("alloc inode error\n");
return EXT2_ERROR;
}
printf("new inode : %u\n", new_inode);
get_inode_location(fs, new_inode, &loc);
read_disk_per_block(fs, loc.group, loc.block, block);
inode_ptr = ((INODE *)block) + loc.offset;
ZeroMemory(inode_ptr, sizeof(INODE));
if (is_dir == EXT2_FT_DIR) {
inode_ptr->mode = 0x41ed; // directory, 755
inode_ptr->link_cnt = 2; // ".", ".."
inode_ptr->block_cnt = 1;
inode_ptr->size = MAX_SECTOR_SIZE * SECTOR_PER_BLOCK;
}
else {
inode_ptr->mode = 0x81A4; // regular, 644
}
write_disk_per_block(fs, loc.group, loc.block, block);
return new_inode;
}
UINT32 expand_block(EXT2_FILESYSTEM * fs, UINT32 inode_num, UINT32 blk_idx, UINT32 prefer_group, UINT32 is_dir)
{
INODE *inode_buf;
EXT2_ENTRY_LOCATION loc;
UINT32 new_block;
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
get_inode_location(fs, inode_num, &loc);
read_disk_per_block(fs, loc.group, loc.block, block);
inode_buf = ((INODE *)block) + loc.offset;
if (inode_buf->i_block[blk_idx]) {
printf("i_block[blk_idx] is full\n");
return EXT2_ERROR;
}
// group 임시로 0으로 해놓음 수정해야함
new_block = alloc_free_data_block_in_group(fs, 0);
if (new_block == -1) {
printf("alloc block error\n");
return EXT2_ERROR;
}
inode_buf->block_cnt++;
inode_buf->i_block[blk_idx] = new_block;
write_disk_per_block(fs, loc.group, loc.block, block);
ZeroMemory(block, sizeof(block));
if (is_dir == EXT2_FT_DIR) {
((EXT2_DIR_ENTRY *)block)->record_len = (MAX_SECTOR_SIZE * SECTOR_PER_BLOCK);
// inode -> size 증가 추가해야 함
}
get_block_location(fs, new_block, &loc);
write_disk_per_block(fs, loc.group, loc.block, block);
return EXT2_SUCCESS;
}
// ------------------------------------------------------
int read_disk_per_block(EXT2_FILESYSTEM *fs, SECTOR group, SECTOR block, BYTE *block_buf)
{
DISK_OPERATIONS* disk = fs->disk;
SECTOR sector_per_block = fs->sb.sector_per_block;
SECTOR real_block_index = group * fs->sb.block_per_group + block;
SECTOR real_sector_index = BOOT_SECTOR_BASE + real_block_index * sector_per_block;
for (SECTOR i = 0; i < sector_per_block; i++)
{
if ( disk->read_sector(fs->disk, real_sector_index + i, &(block_buf[i * disk->bytes_per_sector])) == EXT2_ERROR)
return EXT2_ERROR;
}
return EXT2_SUCCESS;
}
int write_disk_per_block(EXT2_FILESYSTEM *fs, SECTOR group, SECTOR block, BYTE *block_buf)
{
DISK_OPERATIONS* disk = fs->disk;
SECTOR sector_per_block = fs->sb.sector_per_block;
SECTOR real_block_index = group * fs->sb.block_per_group + block;
SECTOR real_sector_index = BOOT_SECTOR_BASE + real_block_index * sector_per_block;
for (SECTOR i = 0; i < sector_per_block; i++)
{
if ( disk->write_sector(fs->disk, real_sector_index + i, &(block_buf[i * disk->bytes_per_sector])) == EXT2_ERROR)
return EXT2_ERROR;
}
return EXT2_SUCCESS;
}
// inode table에서의 inode 위치
int get_inode_location(EXT2_FILESYSTEM *fs, UINT32 inode_num, EXT2_ENTRY_LOCATION *loc) {
if (inode_num < 1)
return EXT2_ERROR;
UINT32 inode_per_group = fs->sb.inode_per_group;
UINT32 table_index = (inode_num - 1) % inode_per_group;
UINT32 inode_per_block = (1024 << fs->sb.log_block_size) / fs->sb.inode_size;
// 128말고 fs->sb.inode_size 하면 안될까
loc->group = (inode_num - 1) / inode_per_group;
loc->block = (table_index / inode_per_block) + fs->gd.start_block_of_inode_table;
loc->offset = table_index % inode_per_block;
return EXT2_SUCCESS;
}
int get_inode(EXT2_FILESYSTEM* fs, const UINT32 inode_num, INODE *inodeBuffer) {
if (inode_num < 1)
return EXT2_ERROR;
BYTE block[MAX_SECTOR_SIZE * SECTOR_PER_BLOCK];
EXT2_ENTRY_LOCATION loc;
if (get_inode_location(fs, inode_num, &loc) == EXT2_ERROR)
return EXT2_ERROR;
if (read_disk_per_block(fs, loc.group, loc.block, block) == EXT2_ERROR)
return EXT2_ERROR;
*inodeBuffer = ((INODE *)block)[loc.offset];
return EXT2_SUCCESS;
}
int get_block_location(EXT2_FILESYSTEM *fs, UINT32 block_num, EXT2_ENTRY_LOCATION *loc) {
if (block_num < 1)
return EXT2_ERROR;
UINT32 block_per_group = fs->sb.block_per_group;
loc->group = block_num / block_per_group;
loc->block = block_num % block_per_group;
loc->offset = 0;
return EXT2_SUCCESS;
}
// ------------------------------------------------------
// int isalpha(unsigned char ch) {
// return ((ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z'));
// }
// int isdigit(unsigned char ch) {
// return (ch >= '0' && ch <= '9');
// }
// name의 format을 검사하는 함수로 바꿈
int format_name(EXT2_FILESYSTEM* fs, const char* name)
{
UINT32 i, length;
UINT32 extender = 0;
UINT32 extenderCurrent = 8;
length = strlen(name);
if (strcmp(name, "..") == 0 || strcmp(name, ".") == 0)
{
return EXT2_SUCCESS;
}
else
{
for (i = 0; i < length; i++)
{
if (name[i] != '.' && !isdigit(name[i]) && !isalpha(name[i])) {
printf("%c is not valid characte\n", name[i]);
return EXT2_ERROR;
}
if (name[i] == '.')
{
if (extender) {
printf("reduplication extender('.')\n");
return EXT2_ERROR;
}
extender = 1;
}
}
if (length > EXT2_NAME_LEN || length == 0 || extenderCurrent > 11) {
printf("wrong length : %u\n", length);