static errcode_t open_and_check(o2fsck_state *ost, char *filename,
int open_flags, uint64_t blkno,
uint64_t blksize)
{
errcode_t ret;
ret = ocfs2_open(filename, open_flags, blkno, blksize, &ost->ost_fs);
if (ret) {
com_err(whoami, ret, "while opening \"%s\"", filename);
goto out;
}
ret = check_superblock(ost);
if (ret) {
printf("fsck saw unrecoverable errors in the super block and "
"will not continue.\n");
goto out;
}
out:
return ret;
}
int main(int argc, char *argv[])
{
int fd;
int i = 0, c = 0;
struct stat filestat;
int inode_number, blk_grp_number;
int inode_grp_offset;
int superblock_present;
int offset;
int filesize;
uint32_t data32;
uint16_t data16;
// Setting up buffers
unsigned char blk[MAX_BLOCK_SIZE];
unsigned char blk_bitmap[MAX_BLOCK_SIZE];
unsigned char inode_bitmap[MAX_BLOCK_SIZE];
unsigned char inode[MAX_INODE_SIZE];
if (argc < 3) {
printf("\nUsage : fileblock [filename] [/dev/sda1]\n\n");
return 1;
}
// Open data file
fd = open(argv[1], O_RDONLY);
if (fd < 0) {
printf("Error opening file\n");
return 1;
}
// Open file system
fs = open(argv[2], O_RDONLY);
if (fs < 0) {
printf("Error opening file system\n");
close(fd);
return 1;
}
// Initialize all the file system specific structures
if (init_fs() != 0) {
printf("Error reading extfs information from super block\n");
close(fs); close(fd);
return 1;
}
// Read inode number of file
if (fstat(fd, &filestat) < 0) {
printf("Error reading inode number for a file\n");
close(fs); close(fd);
return 1;
}
inode_number = filestat.st_ino;
blk_grp_number = (inode_number / INODE_PER_GROUP);
inode_grp_offset = ((inode_number - 1) % INODE_PER_GROUP) * INODE_SIZE;
// Super block copy present in block number 0, 1 and power of 3, 5, 7
superblock_present = check_superblock(blk_grp_number);
printf("Inode number: %d (offset = %d)\n",
inode_number, inode_grp_offset);
printf("Block number: %d (super block = %d)\n",
blk_grp_number, superblock_present);
close(fd);
if (read_gdt(blk_grp_number) < 0) {
close(fs);
return 1;
}
offset = (inode_table_addr * BLOCK_SIZE) + inode_grp_offset;
printf("Inode table entry at : %d\n", offset);
if (lseek(fs, offset, 0) < 0) {
printf("Failed to seek to inode table entry\n");
close(fs);
return 1;
}
// Read inode table
read(fs, inode, INODE_SIZE);
// Decoding inode data which in is LE format
// http://wiki.osdev.org/Ext2
// User id
data16 = inode[3];
data16 = (data16 << 8) | inode[2];
printf("User ID : %d\n", data16);
// File size
data32 = inode[7];
data32 = (data32 << 8) | inode[6];
data32 = (data32 << 8) | inode[5];
data32 = (data32 << 8) | inode[4];
filesize = data32;
printf("Size : %d\n", filesize);
// Address of direct block 0
data32 = inode[43];
data32 = (data32 << 8) | inode[42];
data32 = (data32 << 8) | inode[41];
data32 = (data32 << 8) | inode[40];
printf("Direct Block 0 : %d\n", data32);
// Reading inode data
if (lseek(fs, data32 * BLOCK_SIZE, 0) < 0) {
printf("Failed to seek to inode data block 0\n");
close(fs);
return 1;
}
read(fs, blk, BLOCK_SIZE);
// Showing upto max first 1024 bytes by adding \0 in the data buffer
if (filesize < 1024) {
blk[filesize] = '\0';
} else {
blk[1024] = '\0';
}
printf("Data 0 (max 1024 bytes) :\n%s\n", blk);
close(fs);
return 0;
}
