Minix1.5/commands/badblocks.c
/* badblocks - collect bad blocks in a file Author: Jacob Bunschoten */
/* Usage "badblocks block_special [Up_to_7_blocks]" */
/* This program is written to handle BADBLOCKS on a hard or floppy disk.
* The program asks for block_numbers. These numbers can be obtained with
* the program disk_check; written by A. Tanenbaum. It then creates a
* file on the disk containing up to 7 bad blocks.
*
* BUG:
*
* When the zone_size > block_size it can happen that
* the zone is already allocated. This means some
* file is using this zone and may use all the blocks including
* the bad one. This can be cured by inspecting the zone_bitmap
* (is already done) and change the file if this zone is used.
* This means that another zone must be allocated and
* the inode wich claims this zone must be found and changed.
*
*/
#include <minix/config.h>
#include <minix/type.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
/* Super block table.
*
* The disk layout is:
*
* Item # block
* boot block 1
* super block 1
* inode map s_imap_blocks
* zone map s_zmap_blocks
* inodes (s_ninodes + 1 + INODES_PER_BLOCK - 1)/INODES_PER_BLOCK
* unused
* data zones (s_nzones - s_firstdatazone) << s_log_zone_size
*
*/
struct super_block {
ino_t s_ninodes; /* # usable inodes on the minor device */
zone_nr s_nzones; /* total device size, including bit maps etc */
unshort s_imap_block; /* # of block used by inode bit map */
unshort s_zmap_block; /* # of block used by zone bit map */
zone_nr s_firstdatazone; /* number of first data zone */
short int s_log_zone_size; /* log2 of block/zone */
off_t s_max_size; /* maximum file size on this device */
int s_magic; /* magic number to recognize super-block */
} super_block;
#define SUPER_MAGIC 0x137F
#define NR_ZONE_NUMS 9
#define NR_DZONE_NUMS (NR_ZONE_NUMS -2 )
struct d_inode { /* disk inode. */
mode_t i_mode; /* file type, protection, etc. */
uid_t i_uid; /* user id of the file's owner */
off_t i_size; /* current file size in bytes */
time_t i_mtime; /* when was file data last changed */
gid_t i_gid; /* group number */
nlink_t i_nlinks; /* how many links to this file */
zone_nr i_zone[NR_ZONE_NUMS]; /* blocks nums for direct, ind, and dbl ind */
} d_inode;
#define OK 0
#define NOT_OK 1
#define QUIT 2
#define READ 0
#define WRITE 1
#define HARMLESS 0
#define DIR_CREATED 1
#define DEV_MOUNTED 2
#define FILE_EXISTS 3
#define SUCCESS 4
#define BLOCK_SIZE 1024
#define INODES_PER_BLOCK (BLOCK_SIZE/sizeof(struct d_inode))
#define INODE_SIZE (sizeof (struct d_inode) )
#define SUPER_SIZE (sizeof (struct super_block) )
#define SIZE_OF_INT (sizeof (int) )
/* ====== globals ======= */
char *dev_name;
char f_name[] = ".Bad_XXXXXX";
char file_name[50];
char dir_name[] = "/tmpXXXXXX";
int block[NR_DZONE_NUMS + 1]; /* last block contains zero */
int interactive; /* 1 if interactive (argc == 2) */
int position = 2; /* next block # is argv[position] */
FILE *fp, *fopen();
int fd;
int eofseen; /* set if '\n' seen */
struct stat stat_buf;
struct d_inode *ip;
struct super_block *sp;
extern char *strcat();
/* ====== super block routines ======= */
rw_super(flag)
{ /* read or write a superblock */
int rwd;
lseek(fd, 0L, SEEK_SET); /* rewind */
lseek(fd, (long) BLOCK_SIZE, SEEK_SET); /* seek */
if (flag == READ)
rwd = read(fd, (char *) sp, SUPER_SIZE);
else
rwd = write(fd, (char *) sp, SUPER_SIZE);
if (rwd != SUPER_SIZE) { /* ok ? */
printf("Bad %s in get_super() (should be %d is %d)\n",
flag == READ ? "read" : "write",
SUPER_SIZE, rwd);
done(DIR_CREATED);
}
}
get_super()
/* Get super_block. global pointer sp is used */
{
rw_super(READ);
if (sp->s_magic != SUPER_MAGIC) { /* check */
printf("Bad magic number in super_block?!\n");
done(DIR_CREATED);
}
}
put_super()
{
rw_super(WRITE);
}
/* ========== inode routines =========== */
rw_inode(stat_ptr, rw_mode)
struct stat *stat_ptr;
{
int rwd, i_num;
long blk, offset;
i_num = stat_ptr->st_ino;
blk = (long) (2 + sp->s_imap_block + sp->s_zmap_block);
blk += (long) ((i_num - 1) / INODES_PER_BLOCK);
blk *= (long) (BLOCK_SIZE); /* this block */
offset = (long) ((i_num - 1) % INODES_PER_BLOCK);
offset *= (long) (INODE_SIZE);/* and this offset */
lseek(fd, 0L, SEEK_SET); /* rewind */
lseek(fd, (long) (blk + offset), SEEK_SET); /* seek */
/* Pointer is at the inode */
if (rw_mode == READ) { /* read it */
rwd = read(fd, (char *) ip, INODE_SIZE);
} else { /* write it */
rwd = write(fd, (char *) ip, INODE_SIZE);
}
if (rwd != INODE_SIZE) { /* ok ? */
printf("Bad %s in get_inode()\n", (rw_mode == READ) ? "read" :
"write");
done(DIR_CREATED);
}
}
get_inode(stat_ptr)
struct stat *stat_ptr;
{
int cnt;
rw_inode(stat_ptr, READ);
for (cnt = 0; cnt < NR_ZONE_NUMS; cnt++)
ip->i_zone[cnt] = 0; /* Just to be safe */
}
put_inode(stat_ptr)
struct stat *stat_ptr;
{
rw_inode(stat_ptr, WRITE);
}
/* ============== main program ================= */
main(argc, argv)
char *argv[];
{
int cnt, finished;
unsigned blk_nr;
struct stat dev_stat;
sp = &super_block;
ip = &d_inode;
if (argc < 2 || argc > 9) {
fprintf(stderr, "Usage: %s block_special [up_to_7_blocks]\n", argv[0]);
done(HARMLESS);
}
interactive = (argc == 2 ? 1 : 0);
/* Do some test. */
if (geteuid()) {
printf("Sorry, not in superuser mode \n");
printf("Set_uid bit must be on or you must become super_user\n");
done(HARMLESS);
}
dev_name = argv[1];
mktemp(dir_name);
if (mkdir(dir_name, 0777) == -1) {
fprintf(stderr, "%s is already used in system\n", dir_name);
done(HARMLESS);
}
/* Mount device. This call may fail. */
mount(dev_name, dir_name, 0);
/* Succes. dev was mounted, try to umount */
/* Umount device. Playing with the file system while other processes
* have access to this device is asking for trouble */
if (umount(dev_name) == -1) {
printf("Could not umount device %s.\n", dev_name);
done(HARMLESS);
}
mktemp(f_name);
/* Create "/tmpXXXXpid/.BadXXpid" */
strcat(file_name, dir_name);
strcat(file_name, "/");
strcat(file_name, f_name);
if (mount(dev_name, dir_name, 0) == -1) { /* this call should work */
fprintf(stderr, "Could not mount device anymore\n");
done(HARMLESS);
}
if (stat(file_name, &stat_buf) != -1) {
printf("File %s already exists\n", file_name);
done(DEV_MOUNTED);
}
if ((fp = fopen(file_name, "w")) == NULL) {
printf("Cannot create file %s\n", file_name);
done(DEV_MOUNTED);
}
chmod(file_name, 0); /* "useless" file */
if (stat(file_name, &stat_buf) == -1) {
printf("What? Second call from stat failed\n");
done(FILE_EXISTS);
}
/* Stat buf must be safed. We can now calculate the inode on disk */
fclose(fp);
/* ===== the badblock file is created ===== */
if (umount(dev_name) == -1) {
printf("Can not umount device anymore??? \n");
done(DIR_CREATED);
}
if ((fd = open(dev_name, O_RDWR)) == -1) {
printf("Can not open device %s\n", dev_name);
done(DEV_MOUNTED);
}
if (fstat(fd, &dev_stat) == -1) {
printf("fstat on device %s failed\n", dev_name);
done(DEV_MOUNTED);
}
if ((dev_stat.st_mode & S_IFMT) != S_IFBLK) {
printf("Device \"%s\" is not a block_special.\n", dev_name);
done(DEV_MOUNTED);
}
get_super();
if (sp->s_log_zone_size) {
printf("Block_size != zone_size.");
printf("This program can not handle it\n");
done(DIR_CREATED);
}
get_inode(&stat_buf);
for (finished = 0; !finished;) {
if (interactive)
printf("Give up to %d bad block numbers separated by spaces\n",
NR_DZONE_NUMS);
reset_blks();
cnt = 0; /* cnt keep track of the zone's */
while (cnt < NR_DZONE_NUMS) {
int tst;
if (interactive)
blk_nr = rd_num();
else
blk_nr = rd_cmdline(argc, argv);
if (blk_nr == -1) break;
tst = blk_ok(blk_nr);
/* Test if this block is free */
if (tst == OK) {
cnt++;
save_blk(blk_nr);
} else if (tst == QUIT)
break;
}
if (interactive) show_blks();
if (!cnt) done(FILE_EXISTS);
if (interactive) {
switch (ok("All these blocks ok <y/n/q> (y:Device will change) ")) {
case OK: finished = 1; break;
case NOT_OK: break;
case QUIT: done(FILE_EXISTS);
}
} else {
finished = 1;
}
}
modify(cnt);
close(fd); /* free device */
done(SUCCESS);
}
rd_cmdline(argc, argv)
int argc;
char *argv[];
{
if (position == argc) return(-1);
return(atoi(argv[position++]));
}
modify(nr_blocks)
{
int i;
if (nr_blocks == 0) return;
for (i = 0; i < nr_blocks; i++) {
set_bit(block[i]);
ip->i_zone[i] = block[i];
}
ip->i_size = (long) (BLOCK_SIZE * nr_blocks); /* give file size */
put_inode(&stat_buf); /* save the inode on disk */
put_super(); /* bit_maps too */
}
static blk_cnt = 0;
save_blk(blk_num)
int blk_num;
{
block[blk_cnt++] = blk_num;
}
reset_blks()
{
int i;
for (i = 0; i <= NR_DZONE_NUMS; i++)
block[i] = 0; /* Note: Last block_number is set to zero */
blk_cnt = 0;
}
show_blks()
{
int i;
for (i = 0; i < blk_cnt; i++) printf("Block[%d] = %d\n", i, block[i]);
}
blk_is_used(blk_num)
int blk_num;
{ /* return TRUE(1) if used */
int i;
for (i = 0; block[i] && block[i] != blk_num; i++);
return(block[i] != 0) ? 1 : 0;
}
/* ===== bitmap handling ====== */
#define BIT_MAP_SHIFT 13
#define INT_BITS (SIZE_OF_INT << 3)
blk_ok(num) /* is this zone free (y/n) */
unsigned num;
{
long blk_offset;
int rd;
int block, offset, words, bit, tst_word;
unsigned z_num;
if (num < 0) {
return QUIT; /* negative number is not allowed */
}
if (blk_is_used(num)) {
printf("Duplicate block (%d) given\n", num);
return NOT_OK;
}
/* Assumption zone_size == block_size */
z_num = num - (sp->s_firstdatazone - 1); /* account offset */
/* Calculate the word in the bitmap. */
block = z_num >> BIT_MAP_SHIFT; /* which block */
offset = z_num - (block << BIT_MAP_SHIFT); /* offset */
words = z_num / INT_BITS; /* which word */
blk_offset = (long) (2 + sp->s_imap_block); /* zone map */
blk_offset *= (long) BLOCK_SIZE; /* of course in block */
blk_offset += (long) (words * SIZE_OF_INT); /* offset */
lseek(fd, 0L, SEEK_SET); /* rewind */
lseek(fd, blk_offset, SEEK_SET); /* set pointer at word */
rd = read(fd, (char *) &tst_word, SIZE_OF_INT);
if (rd != SIZE_OF_INT) {
printf("Read error in bitmap\n");
done(DIR_CREATED);
}
/* We have the tst_word, check if bit was off */
bit = offset % INT_BITS;
if (((tst_word >> bit) & 01) == 0) /* free */
return OK;
else {
printf("Bad number %d. ", num);
printf("This zone (block) is marked in bitmap\n");
return NOT_OK;
}
}
set_bit(num) /* write in the bitmap */
unsigned num;
{
int rwd;
long blk_offset;
int block, offset, words, tst_word, bit;
unsigned z_num;
char wrd_str[17], bit_str[17];
z_num = num + 1 - sp->s_firstdatazone;
block = z_num >> BIT_MAP_SHIFT; /* which block */
offset = z_num - (block << BIT_MAP_SHIFT); /* offset in block */
words = offset / INT_BITS; /* which word */
blk_offset = (long) (2 + sp->s_imap_block);
blk_offset *= (long) BLOCK_SIZE;
blk_offset += (long) (words * SIZE_OF_INT);
lseek(fd, 0L, SEEK_SET); /* rewind */
lseek(fd, blk_offset, SEEK_SET);
rwd = read(fd, (char *) &tst_word, SIZE_OF_INT);
if (rwd != SIZE_OF_INT) {
printf("Read error in bitmap\n");
done(DEV_MOUNTED);
}
bit = offset % INT_BITS;
if (((tst_word >> bit) & 01) == 0) { /* free */
lseek(fd, 0L, SEEK_SET);/* rewind */
lseek(fd, blk_offset, SEEK_SET);
tst_word |= (1 << bit); /* not free anymore */
rwd = write(fd, (char *) &tst_word, SIZE_OF_INT);
if (rwd != SIZE_OF_INT) {
printf("Bad write in zone map\n");
printf("Check file system \n");
done(DIR_CREATED);
}
return;
}
printf("Bit map indicates that block %u is in use. Not marked.\n",num);
/* done(DIR_CREATED); */
return;
}
/* ======= interactive interface ======= */
rd_num()
{ /* read a number from stdin */
static num;
int c;
if (eofseen) return(-1);
do {
c = getchar();
if (c == EOF || c == '\n') return(-1);
} while (c != '-' && (c < '0' || c > '9'));
if (c == '-') {
printf("Block numbers must be positive\n");
exit(1);
}
num = 0;
while (c >= '0' && c <= '9') {
num *= 10;
num += c - '0';
c = getchar();
if (c == '\n') eofseen = 1;
}
return num;
}
ok(str)
char *str;
{
int c;
for (;;) {
printf("%s", str);
while ((c = getchar()) != EOF &&
c != 'y' && c != 'n' && c != 'q')
if (c != '\n') printf(" Bad character %c\n", (char) c);
switch (c) {
case EOF: return QUIT;
case 'y': return OK;
case 'n': return NOT_OK;
case 'q': return QUIT;
}
printf("\n");
}
}
done(nr)
int nr;
{
switch (nr) {
case SUCCESS:
case FILE_EXISTS:
unlink(file_name);
case DEV_MOUNTED:
umount(dev_name);
case DIR_CREATED:
unlink(dir_name);
case HARMLESS:;
}
sync();
exit(nr == SUCCESS ? 0 : 1);
}