mkfs.c

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/* mkfs  -  make the MINIX filesystem   Authors: Tanenbaum et al. */

/*      Authors: Andy Tanenbaum, Paul Ogilvie, Frans Meulenbroeks, Bruce Evans
 *
 * This program can make both version 1 and version 2 file systems, as follows:
 *      mkfs /dev/fd0 1200      # Version 2 (default)
 *      mkfs -1 /dev/fd0 360    # Version 1
 *
 */

#include <sys/types.h>
#include <sys/dir.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/type.h>
#include <minix/minlib.h>
#include "../../servers/fs/const.h"
#if (MACHINE == IBM_PC)
#include <minix/partition.h>
#include <minix/u64.h>
#include <sys/ioctl.h>
#endif
#include <a.out.h>
#include <tools.h>
#include <dirent.h>

#undef EXTERN
#define EXTERN                  /* get rid of EXTERN by making it null */
#include "../../servers/fs/type.h"
#include "../../servers/fs/super.h"
#include <minix/fslib.h>

#ifndef max
#define max(a,b) ((a) > (b) ? (a) : (b))
#endif

#ifndef DOS
#ifndef UNIX
#define UNIX
#endif
#endif

#define INODE_MAP            2
#define MAX_TOKENS          10
#define LINE_LEN           200
#define BIN                  2
#define BINGRP               2
#define BIT_MAP_SHIFT       13
#define N_BLOCKS         MAX_BLOCK_NR
#define N_BLOCKS16        (128L * 1024)
#define INODE_MAX       ((unsigned) 65535)

/* You can make a really large file system on a 16-bit system, but the array
 * of bits that get_block()/putblock() needs gets a bit big, so we can only
 * prefill MAX_INIT blocks.  (16-bit fsck can't check a file system larger
 * than N_BLOCKS16 anyway.)
 */
#define MAX_INIT         (sizeof(char *) == 2 ? N_BLOCKS16 : N_BLOCKS)


#ifdef DOS
maybedefine O_RDONLY 4          /* O_RDONLY | BINARY_BIT */
 maybedefine BWRITE 5           /* O_WRONLY | BINARY_BIT */
#endif

#if (MACHINE == ATARI)
int isdev;
#endif

extern char *optarg;
extern int optind;

int next_zone, next_inode, zone_size, zone_shift = 0, zoff;
block_t nrblocks;
int inode_offset, lct = 0, disk, fd, print = 0, file = 0;
unsigned int nrinodes;
int override = 0, simple = 0, dflag;
int donttest;                   /* skip test if it fits on medium */
char *progname;

long current_time, bin_time;
char *zero, *lastp;
char umap[MAX_INIT / 8];        /* bit map tells if block read yet */
block_t zone_map;               /* where is zone map? (depends on # inodes) */
int inodes_per_block;
int fs_version;
unsigned int block_size;
block_t max_nrblocks;

FILE *proto;

_PROTOTYPE(int main, (int argc, char **argv));
_PROTOTYPE(block_t sizeup, (char *device));
_PROTOTYPE(void super, (zone_t zones, Ino_t inodes));
_PROTOTYPE(void rootdir, (Ino_t inode));
_PROTOTYPE(void eat_dir, (Ino_t parent));
_PROTOTYPE(void eat_file, (Ino_t inode, int f));
_PROTOTYPE(void enter_dir, (Ino_t parent, char *name, Ino_t child));
_PROTOTYPE(void incr_size, (Ino_t n, long count));
_PROTOTYPE(PRIVATE ino_t alloc_inode, (int mode, int usrid, int grpid));
_PROTOTYPE(PRIVATE zone_t alloc_zone, (void));
_PROTOTYPE(void add_zone, (Ino_t n, zone_t z, long bytes, long cur_time));
_PROTOTYPE(void add_z_1, (Ino_t n, zone_t z, long bytes, long cur_time));
_PROTOTYPE(void add_z_2, (Ino_t n, zone_t z, long bytes, long cur_time));
_PROTOTYPE(void incr_link, (Ino_t n));
_PROTOTYPE(void insert_bit, (block_t block, int bit));
_PROTOTYPE(int mode_con, (char *p));
_PROTOTYPE(void getline, (char line[LINE_LEN], char *parse[MAX_TOKENS]));
_PROTOTYPE(void check_mtab, (char *devname));
_PROTOTYPE(long file_time, (int f));
_PROTOTYPE(void pexit, (char *s));
_PROTOTYPE(void copy, (char *from, char *to, int count));
_PROTOTYPE(void print_fs, (void));
_PROTOTYPE(int read_and_set, (block_t n));
_PROTOTYPE(void special, (char *string));
_PROTOTYPE(void get_block, (block_t n, char *buf));
_PROTOTYPE(void get_super_block, (char *buf));
_PROTOTYPE(void put_block, (block_t n, char *buf));
_PROTOTYPE(void cache_init, (void));
_PROTOTYPE(void flush, (void));
_PROTOTYPE(void mx_read, (int blocknr, char *buf));
_PROTOTYPE(void mx_write, (int blocknr, char *buf));
_PROTOTYPE(void dexit, (char *s, int sectnum, int err));
_PROTOTYPE(void usage, (void));
_PROTOTYPE(char *alloc_block, (void));

/*================================================================
 *                    mkfs  -  make filesystem
 *===============================================================*/
int main(argc, argv)
int argc;
char *argv[];
{
  int nread, mode, usrid, grpid, ch;
  block_t blocks, maxblocks;
  block_t i;
  ino_t root_inum;
  ino_t inodes;
  zone_t zones;
  char *token[MAX_TOKENS], line[LINE_LEN];
  struct stat statbuf;

  /* Get two times, the current time and the mod time of the binary of
   * mkfs itself.  When the -d flag is used, the later time is put into
   * the i_mtimes of all the files.  This feature is useful when
   * producing a set of file systems, and one wants all the times to be
   * identical. First you set the time of the mkfs binary to what you
   * want, then go.
   */
  current_time = time((time_t *) 0);    /* time mkfs is being run */
  stat(argv[0], &statbuf);
  bin_time = statbuf.st_mtime;  /* time when mkfs binary was last modified */

  /* Process switches. */
  progname = argv[0];
  blocks = 0;
  i = 0;
  fs_version = 3;
  inodes_per_block = 0;
  max_nrblocks = N_BLOCKS;
  block_size = 0;
  while ((ch = getopt(argc, argv, "12b:di:lotB:")) != EOF)
        switch (ch) {
            case '1':
                fs_version = 1;
                inodes_per_block = V1_INODES_PER_BLOCK;
                max_nrblocks = 0xFFFF;
                break;
            case '2':
                fs_version = 2;
                break;
            case 'b':
                blocks = strtoul(optarg, (char **) NULL, 0);
                break;
            case 'd':
                dflag = 1;
                current_time = bin_time;
                break;
            case 'i':
                i = strtoul(optarg, (char **) NULL, 0);
                break;
            case 'l':   print = 1;      break;
            case 'o':   override = 1;   break;
            case 't':   donttest = 1;   break;
            case 'B':   block_size = atoi(optarg);      break;
            default:    usage();
        }

  if(fs_version == 3) {
        if(!block_size) block_size = _MAX_BLOCK_SIZE; /* V3 default block size */
        if(block_size%SECTOR_SIZE || block_size < _MIN_BLOCK_SIZE) {
                fprintf(stderr, "block size must be multiple of sector (%d) "
                        "and at least %d bytes\n",
                        SECTOR_SIZE, _MIN_BLOCK_SIZE);
                pexit("specified block size illegal");
        }
        if(block_size%V2_INODE_SIZE) {
                fprintf(stderr, "block size must be a multiple of inode size (%d bytes)\n",
                        V2_INODE_SIZE);
                pexit("specified block size illegal");
        }
  } else {
        if(block_size) {
                pexit("Can't specify a block size if FS version is <3");
        }
        block_size = _STATIC_BLOCK_SIZE;        /* V1/V2 block size */
  }

  if(!inodes_per_block)
        inodes_per_block = V2_INODES_PER_BLOCK(block_size);

  /* now that the block size is known, do buffer allocations where
   * possible.
   */
  zero = alloc_block();
  bzero(zero, block_size);

  /* Determine the size of the device if not specified as -b or proto. */
  maxblocks = sizeup(argv[optind]);
  if (argc - optind == 1 && blocks == 0) {
        blocks = maxblocks;
        /* blocks == 0 is checked later, but leads to a funny way of
         * reporting a 0-sized device (displays usage).
         */
        if(blocks < 1) {
                fprintf(stderr, "%s: this device can't hold a filesystem.\n",
                        progname);
                return 1;
        }
  }

  /* The remaining args must be 'special proto', or just 'special' if the
   * no. of blocks has already been specified.
   */
  if (argc - optind != 2 && (argc - optind != 1 || blocks == 0)) usage();

  if (blocks > maxblocks) {
        fprintf(stderr, "%s: %s: number of blocks too large for device.\n",
                progname, argv[optind]);
        return 1;
  }

  /* Check special. */
  check_mtab(argv[optind]);

  /* Check and start processing proto. */
  optarg = argv[++optind];
  if (optind < argc && (proto = fopen(optarg, "r")) != NULL) {
        /* Prototype file is readable. */
        lct = 1;
        getline(line, token);   /* skip boot block info */

        /* Read the line with the block and inode counts. */
        getline(line, token);
        blocks = atol(token[0]);
        if (blocks > max_nrblocks) pexit("Block count too large");
        if (sizeof(char *) == 2 && blocks > N_BLOCKS16) {
                fprintf(stderr,
                "%s: warning: FS is larger than the %dM that fsck can check!\n",
                        progname, (int) (N_BLOCKS16 / (1024L * 1024)));
        }
        inodes = atoi(token[1]);

        /* Process mode line for root directory. */
        getline(line, token);
        mode = mode_con(token[0]);
        usrid = atoi(token[1]);
        grpid = atoi(token[2]);
  } else {
        lct = 0;
        if (optind < argc) {
                /* Maybe the prototype file is just a size.  Check. */
                blocks = strtoul(optarg, (char **) NULL, 0);
                if (blocks == 0) pexit("Can't open prototype file");
        }
        if (i == 0) {
                int kb;
                kb = blocks * (max(block_size,1024) / 1024);
                /* The default for inodes is 2 blocks per kb, rounded up
                 * to fill an inode block.  Above 20M, the average files are
                 * sure to be larger because it is hard to fill up 20M with
                 * tiny files, so reduce the default number of inodes.  This
                 * default can always be overridden by using the '-i option.
                 */
                i = kb / 2;
                if (kb >= 20000) i = kb / 3;
                if (kb >= 40000) i = kb / 4;
                if (kb >= 60000) i = kb / 5;
                if (kb >= 80000) i = kb / 6;
                if (kb >= 100000) i = kb / 7;

                /* round up to fill inode block */
                i += inodes_per_block - 1;
                i = i / inodes_per_block * inodes_per_block;
                if (i > INODE_MAX && fs_version < 3) i = INODE_MAX;

        }
        if (blocks < 5) pexit("Block count too small");
        if (blocks > max_nrblocks) pexit("Block count too large");
        if (i < 1) pexit("Inode count too small");
        if (i > INODE_MAX && fs_version < 3) pexit("Inode count too large");
        inodes = (ino_t) i;

        /* Make simple file system of the given size, using defaults. */
        mode = 040777;
        usrid = BIN;
        grpid = BINGRP;
        simple = 1;
  }

  if(ULONG_MAX / block_size <= blocks-1) {
        fprintf(stderr, "Warning: too big for filesystem to currently\n");
        fprintf(stderr, "run on (max 4GB), truncating.\n");
        blocks = ULONG_MAX / block_size;
  }

  nrblocks = blocks;
  nrinodes = inodes;

  /* Open special. */
  special(argv[--optind]);

#ifdef UNIX
  if (!donttest) {
        short *testb;
        ssize_t w;

        testb = (short *) alloc_block();

        /* Try writing the last block of partition or diskette. */
        if(lseek(fd, (off_t) (blocks - 1) * block_size, SEEK_SET) < 0) {
                pexit("couldn't seek to last block to test size (1)");
        }
        testb[0] = 0x3245;
        testb[1] = 0x11FF;
        testb[block_size-1] = 0x1F2F;
        if ((w=write(fd, (char *) testb, block_size)) != block_size) {
                if(w < 0) perror("write");
                printf("%d/%d\n", w, block_size);
                pexit("File system is too big for minor device (write)");
        }
        sync();                 /* flush write, so if error next read fails */
        if(lseek(fd, (off_t) (blocks - 1) * block_size, SEEK_SET) < 0) {
                pexit("couldn't seek to last block to test size (2)");
        }
        testb[0] = 0;
        testb[1] = 0;
        nread = read(fd, (char *) testb, block_size);
        if (nread != block_size || testb[0] != 0x3245 || testb[1] != 0x11FF ||
                testb[block_size-1] != 0x1F2F) {
                if(nread < 0) perror("read");
                pexit("File system is too big for minor device (read)");
        }
        lseek(fd, (off_t) (blocks - 1) * block_size, SEEK_SET);
        testb[0] = 0;
        testb[1] = 0;
        if (write(fd, (char *) testb, block_size) != block_size)
                pexit("File system is too big for minor device (write2)");
        lseek(fd, 0L, SEEK_SET);
        free(testb);
  }
#endif

  /* Make the file-system */

  cache_init();

#if (MACHINE == ATARI)
  if (isdev) {
        char block0[BLOCK_SIZE];
        get_block((block_t) 0, block0);
        /* Need to read twice; first time gets an empty block */
        get_block((block_t) 0, block0);
        /* Zero parts of the boot block so the disk won't be
         * recognized as a tos disk any more. */
        block0[0] = block0[1] = 0;      /* branch code to boot code    */
        strncpy(&block0[2], "MINIX ", (size_t) 6);
        block0[16] = 0;         /* number of FATS              */
        block0[17] = block0[18] = 0;    /* number of dir entries       */
        block0[22] = block0[23] = 0;    /* sectors/FAT                 */
        bzero(&block0[30], 480);/* boot code                   */
        put_block((block_t) 0, block0);
  } else
#endif

        put_block((block_t) 0, zero);   /* Write a null boot block. */

  zone_shift = 0;               /* for future use */
  zones = nrblocks >> zone_shift;

  super(zones, inodes);

  root_inum = alloc_inode(mode, usrid, grpid);
  rootdir(root_inum);
  if (simple == 0) eat_dir(root_inum);

  if (print) print_fs();
  flush();
  return(0);

  /* NOTREACHED */
}                               /* end main */


/*================================================================
 *                    sizeup  -  determine device size
 *===============================================================*/
block_t sizeup(device)
char *device;
{
  int fd;
  struct partition entry;
  block_t d;
  struct stat st;

  if ((fd = open(device, O_RDONLY)) == -1) {
        if (errno != ENOENT)
                perror("sizeup open");
        return 0;
  }
  if (ioctl(fd, DIOCGETP, &entry) == -1) {
        perror("sizeup ioctl");
        if(fstat(fd, &st) < 0) {
                perror("fstat");
                entry.size = cvu64(0);
        } else {
                fprintf(stderr, "used fstat instead\n");
                entry.size = cvu64(st.st_size);
        }
  }
  close(fd);
  d = div64u(entry.size, block_size);
  return d;
}


/*================================================================
 *                 super  -  construct a superblock
 *===============================================================*/

void super(zones, inodes)
zone_t zones;
ino_t inodes;
{
  unsigned int i;
  int inodeblks;
  int initblks;

  zone_t initzones, nrzones, v1sq, v2sq;
  zone_t zo;
  struct super_block *sup;
  char *buf, *cp;

  buf = alloc_block();

  for (cp = buf; cp < &buf[block_size]; cp++) *cp = 0;
  sup = (struct super_block *) buf;     /* lint - might use a union */

  sup->s_ninodes = inodes;
  if (fs_version == 1) {
        sup->s_nzones = zones;
  } else {
        sup->s_nzones = 0;      /* not used in V2 - 0 forces errors early */
        sup->s_zones = zones;
  }
  sup->s_imap_blocks = bitmapsize((bit_t) (1 + inodes), block_size);
  sup->s_zmap_blocks = bitmapsize((bit_t) zones, block_size);
  inode_offset = sup->s_imap_blocks + sup->s_zmap_blocks + 2;
  inodeblks = (inodes + inodes_per_block - 1) / inodes_per_block;
  initblks = inode_offset + inodeblks;
  initzones = (initblks + (1 << zone_shift) - 1) >> zone_shift;
  nrzones = nrblocks >> zone_shift;
  sup->s_firstdatazone = (initblks + (1 << zone_shift) - 1) >> zone_shift;
  zoff = sup->s_firstdatazone - 1;
  sup->s_log_zone_size = zone_shift;
  if (fs_version == 1) {
        sup->s_magic = SUPER_MAGIC;     /* identify super blocks */
        v1sq = (zone_t) V1_INDIRECTS * V1_INDIRECTS;
        zo = V1_NR_DZONES + (long) V1_INDIRECTS + v1sq;
        sup->s_max_size = zo * block_size;
  } else {
        v2sq = (zone_t) V2_INDIRECTS(block_size) * V2_INDIRECTS(block_size);
        zo = V2_NR_DZONES + (zone_t) V2_INDIRECTS(block_size) + v2sq;
        if(fs_version == 2) {
                sup->s_magic = SUPER_V2;/* identify super blocks */
                sup->s_max_size = zo * block_size;
        } else {
                sup->s_magic = SUPER_V3;
                sup->s_block_size = block_size;
                sup->s_disk_version = 0;
#define MAX_MAX_SIZE    ((unsigned long) 0xffffffff)
                if(MAX_MAX_SIZE/block_size < zo) {
                        sup->s_max_size = MAX_MAX_SIZE;
                }
                else {
                        sup->s_max_size = zo * block_size;
                }
        }
  }

  zone_size = 1 << zone_shift;  /* nr of blocks per zone */

  if (lseek(fd, (off_t) _STATIC_BLOCK_SIZE, SEEK_SET) == (off_t) -1) {
        pexit("super() couldn't seek");
  }
  if (write(fd, buf, _STATIC_BLOCK_SIZE) != _STATIC_BLOCK_SIZE) {
        pexit("super() couldn't write");
  }

  /* Clear maps and inodes. */
  for (i = 2; i < initblks; i++) put_block((block_t) i, zero);

  next_zone = sup->s_firstdatazone;
  next_inode = 1;

  zone_map = INODE_MAP + sup->s_imap_blocks;

  insert_bit(zone_map, 0);      /* bit zero must always be allocated */
  insert_bit((block_t) INODE_MAP, 0);   /* inode zero not used but
                                         * must be allocated */

  free(buf);
}


/*================================================================
 *              rootdir  -  install the root directory
 *===============================================================*/
void rootdir(inode)
ino_t inode;
{
  zone_t z;

  z = alloc_zone();
  add_zone(inode, z, 2 * sizeof(struct direct), current_time);
  enter_dir(inode, ".", inode);
  enter_dir(inode, "..", inode);
  incr_link(inode);
  incr_link(inode);
}


/*================================================================
 *          eat_dir  -  recursively install directory
 *===============================================================*/
void eat_dir(parent)
ino_t parent;
{
  /* Read prototype lines and set up directory. Recurse if need be. */
  char *token[MAX_TOKENS], *p;
  char line[LINE_LEN];
  int mode, usrid, grpid, maj, min, f;
  ino_t n;
  zone_t z;
  long size;

  while (1) {
        getline(line, token);
        p = token[0];
        if (*p == '$') return;
        p = token[1];
        mode = mode_con(p);
        usrid = atoi(token[2]);
        grpid = atoi(token[3]);
        if (grpid & 0200) fprintf(stderr, "A.S.Tanenbaum\n");
        n = alloc_inode(mode, usrid, grpid);

        /* Enter name in directory and update directory's size. */
        enter_dir(parent, token[0], n);
        incr_size(parent, sizeof(struct direct));

        /* Check to see if file is directory or special. */
        incr_link(n);
        if (*p == 'd') {
                /* This is a directory. */
                z = alloc_zone();       /* zone for new directory */
                add_zone(n, z, 2 * sizeof(struct direct), current_time);
                enter_dir(n, ".", n);
                enter_dir(n, "..", parent);
                incr_link(parent);
                incr_link(n);
                eat_dir(n);
        } else if (*p == 'b' || *p == 'c') {
                /* Special file. */
                maj = atoi(token[4]);
                min = atoi(token[5]);
                size = 0;
                if (token[6]) size = atoi(token[6]);
                size = block_size * size;
                add_zone(n, (zone_t) ((maj << 8) | min), size, current_time);
        } else {
                /* Regular file. Go read it. */
                if ((f = open(token[4], O_RDONLY)) < 0) {
                        fprintf(stderr, "%s: Can't open %s: %s\n",
                                progname, token[4], strerror(errno));
                } else {
                        eat_file(n, f);
                }
        }
  }

}

/*================================================================
 *              eat_file  -  copy file to MINIX
 *===============================================================*/
/* Zonesize >= blocksize */
void eat_file(inode, f)
ino_t inode;
int f;
{
  int ct, i, j, k;
  zone_t z;
  char *buf;
  long timeval;

  buf = alloc_block();

  do {
        for (i = 0, j = 0; i < zone_size; i++, j += ct) {
                for (k = 0; k < block_size; k++) buf[k] = 0;
                if ((ct = read(f, buf, block_size)) > 0) {
                        if (i == 0) z = alloc_zone();
                        put_block((z << zone_shift) + i, buf);
                }
        }
        timeval = (dflag ? current_time : file_time(f));
        if (ct) add_zone(inode, z, (long) j, timeval);
  } while (ct == block_size);
  close(f);
}



/*================================================================
 *          directory & inode management assist group
 *===============================================================*/
void enter_dir(parent, name, child)
ino_t parent, child;
char *name;
{
  /* Enter child in parent directory */
  /* Works for dir > 1 block and zone > block */
  int i, j, k, l, off;
  block_t b;
  zone_t z;
  char *p1, *p2;
  struct direct *dir_entry;
  d1_inode ino1[V1_INODES_PER_BLOCK];
  d2_inode *ino2;
  int nr_dzones;

  b = ((parent - 1) / inodes_per_block) + inode_offset;
  off = (parent - 1) % inodes_per_block;

  if(!(dir_entry = malloc(NR_DIR_ENTRIES(block_size) * sizeof(*dir_entry))))
        pexit("couldn't allocate directory entry");

  if(!(ino2 = malloc(V2_INODES_PER_BLOCK(block_size) * sizeof(*ino2))))
        pexit("couldn't allocate block of inodes entry");

  if (fs_version == 1) {
        get_block(b, (char *) ino1);
        nr_dzones = V1_NR_DZONES;
  } else {
        get_block(b, (char *) ino2);
        nr_dzones = V2_NR_DZONES;
  }
  for (k = 0; k < nr_dzones; k++) {
        if (fs_version == 1) {
                z = ino1[off].d1_zone[k];
                if (z == 0) {
                        z = alloc_zone();
                        ino1[off].d1_zone[k] = z;
                }
        } else {
                z = ino2[off].d2_zone[k];
                if (z == 0) {
                        z = alloc_zone();
                        ino2[off].d2_zone[k] = z;
                }
        }
        for (l = 0; l < zone_size; l++) {
                get_block((z << zone_shift) + l, (char *) dir_entry);
                for (i = 0; i < NR_DIR_ENTRIES(block_size); i++) {
                        if (dir_entry[i].d_ino == 0) {
                                dir_entry[i].d_ino = child;
                                p1 = name;
                                p2 = dir_entry[i].d_name;
                                j = sizeof(dir_entry[i].d_name);
                                while (j--) {
                                        *p2++ = *p1;
                                        if (*p1 != 0) p1++;
                                }
                                put_block((z << zone_shift) + l, (char *) dir_entry);
                                if (fs_version == 1) {
                                        put_block(b, (char *) ino1);
                                } else {
                                        put_block(b, (char *) ino2);
                                }
                                free(dir_entry);
                                free(ino2);
                                return;
                        }
                }
        }
  }

  printf("Directory-inode %d beyond direct blocks.  Could not enter %s\n",
         parent, name);
  pexit("Halt");
}


void add_zone(n, z, bytes, cur_time)
ino_t n;
zone_t z;
long bytes, cur_time;
{
  if (fs_version == 1) {
        add_z_1(n, z, bytes, cur_time);
  } else {
        add_z_2(n, z, bytes, cur_time);
  }
}

void add_z_1(n, z, bytes, cur_time)
ino_t n;
zone_t z;
long bytes, cur_time;
{
  /* Add zone z to inode n. The file has grown by 'bytes' bytes. */

  int off, i;
  block_t b;
  zone_t indir;
  zone1_t blk[V1_INDIRECTS];
  d1_inode *p;
  d1_inode inode[V1_INODES_PER_BLOCK];

  b = ((n - 1) / V1_INODES_PER_BLOCK) + inode_offset;
  off = (n - 1) % V1_INODES_PER_BLOCK;
  get_block(b, (char *) inode);
  p = &inode[off];
  p->d1_size += bytes;
  p->d1_mtime = cur_time;
  for (i = 0; i < V1_NR_DZONES; i++)
        if (p->d1_zone[i] == 0) {
                p->d1_zone[i] = (zone1_t) z;
                put_block(b, (char *) inode);
                return;
        }
  put_block(b, (char *) inode);

  /* File has grown beyond a small file. */
  if (p->d1_zone[V1_NR_DZONES] == 0)
        p->d1_zone[V1_NR_DZONES] = (zone1_t) alloc_zone();
  indir = p->d1_zone[V1_NR_DZONES];
  put_block(b, (char *) inode);
  b = indir << zone_shift;
  get_block(b, (char *) blk);
  for (i = 0; i < V1_INDIRECTS; i++)
        if (blk[i] == 0) {
                blk[i] = (zone1_t) z;
                put_block(b, (char *) blk);
                return;
        }
  pexit("File has grown beyond single indirect");
}

void add_z_2(n, z, bytes, cur_time)
ino_t n;
zone_t z;
long bytes, cur_time;
{
  /* Add zone z to inode n. The file has grown by 'bytes' bytes. */

  int off, i;
  block_t b;
  zone_t indir;
  zone_t *blk;
  d2_inode *p;
  d2_inode *inode;

  if(!(blk = malloc(V2_INDIRECTS(block_size)*sizeof(*blk))))
        pexit("Couldn't allocate indirect block");

  if(!(inode = malloc(V2_INODES_PER_BLOCK(block_size)*sizeof(*inode))))
        pexit("Couldn't allocate block of inodes");

  b = ((n - 1) / V2_INODES_PER_BLOCK(block_size)) + inode_offset;
  off = (n - 1) % V2_INODES_PER_BLOCK(block_size);
  get_block(b, (char *) inode);
  p = &inode[off];
  p->d2_size += bytes;
  p->d2_mtime = cur_time;
  for (i = 0; i < V2_NR_DZONES; i++)
        if (p->d2_zone[i] == 0) {
                p->d2_zone[i] = z;
                put_block(b, (char *) inode);
                free(blk);
                free(inode);
                return;
        }
  put_block(b, (char *) inode);

  /* File has grown beyond a small file. */
  if (p->d2_zone[V2_NR_DZONES] == 0) p->d2_zone[V2_NR_DZONES] = alloc_zone();
  indir = p->d2_zone[V2_NR_DZONES];
  put_block(b, (char *) inode);
  b = indir << zone_shift;
  get_block(b, (char *) blk);
  for (i = 0; i < V2_INDIRECTS(block_size); i++)
        if (blk[i] == 0) {
                blk[i] = z;
                put_block(b, (char *) blk);
                free(blk);
                free(inode);
                return;
        }
  pexit("File has grown beyond single indirect");
}


void incr_link(n)
ino_t n;
{
  /* Increment the link count to inode n */
  int off;
  static int enter = 0;
  block_t b;

  if(enter) exit(1);

  b = ((n - 1) / inodes_per_block) + inode_offset;
  off = (n - 1) % inodes_per_block;
  if (fs_version == 1) {
        d1_inode inode1[V1_INODES_PER_BLOCK];

        get_block(b, (char *) inode1);
        inode1[off].d1_nlinks++;
        put_block(b, (char *) inode1);
  } else {
        static d2_inode *inode2 = NULL;
        int n;

        n = sizeof(*inode2) * V2_INODES_PER_BLOCK(block_size);
        if(!inode2 && !(inode2 = malloc(n)))
                pexit("couldn't allocate a block of inodes");

        get_block(b, (char *) inode2);
        inode2[off].d2_nlinks++;
        put_block(b, (char *) inode2);
  }
  enter = 0;
}


void incr_size(n, count)
ino_t n;
long count;
{
  /* Increment the file-size in inode n */
  block_t b;
  int off;

  b = ((n - 1) / inodes_per_block) + inode_offset;
  off = (n - 1) % inodes_per_block;
  if (fs_version == 1) {
        d1_inode inode1[V1_INODES_PER_BLOCK];

        get_block(b, (char *) inode1);
        inode1[off].d1_size += count;
        put_block(b, (char *) inode1);
  } else {
        d2_inode *inode2;
        if(!(inode2 = malloc(V2_INODES_PER_BLOCK(block_size) * sizeof(*inode2))))
                pexit("couldn't allocate a block of inodes");

        get_block(b, (char *) inode2);
        inode2[off].d2_size += count;
        put_block(b, (char *) inode2);
        free(inode2);
  }
}


/*================================================================
 *                   allocation assist group
 *===============================================================*/
PRIVATE ino_t alloc_inode(mode, usrid, grpid)
int mode, usrid, grpid;
{
  ino_t num;
  int off;
  block_t b;

  num = next_inode++;
  if (num > nrinodes) {
        fprintf(stderr, "have %d inodoes\n", nrinodes);
        pexit("File system does not have enough inodes");
  }
  b = ((num - 1) / inodes_per_block) + inode_offset;
  off = (num - 1) % inodes_per_block;
  if (fs_version == 1) {
        d1_inode inode1[V1_INODES_PER_BLOCK];

        get_block(b, (char *) inode1);
        inode1[off].d1_mode = mode;
        inode1[off].d1_uid = usrid;
        inode1[off].d1_gid = grpid;
        put_block(b, (char *) inode1);
  } else {
        d2_inode *inode2;

        if(!(inode2 = malloc(V2_INODES_PER_BLOCK(block_size) * sizeof(*inode2))))
                pexit("couldn't allocate a block of inodes");

        get_block(b, (char *) inode2);
        inode2[off].d2_mode = mode;
        inode2[off].d2_uid = usrid;
        inode2[off].d2_gid = grpid;
        put_block(b, (char *) inode2);

        free(inode2);
  }

  /* Set the bit in the bit map. */
  /* DEBUG FIXME.  This assumes the bit is in the first inode map block. */
  insert_bit((block_t) INODE_MAP, (int) num);
  return(num);
}


PRIVATE zone_t alloc_zone()
{
  /* Allocate a new zone */
  /* Works for zone > block */
  block_t b;
  int i;
  zone_t z;

  z = next_zone++;
  b = z << zone_shift;
  if ((b + zone_size) > nrblocks)
        pexit("File system not big enough for all the files");
  for (i = 0; i < zone_size; i++)
        put_block(b + i, zero); /* give an empty zone */
  /* DEBUG FIXME.  This assumes the bit is in the first zone map block. */
  insert_bit(zone_map, (int) (z - zoff));       /* lint, NOT OK because
                                                 * z hasn't been broken
                                                 * up into block +
                                                 * offset yet. */
  return(z);
}


void insert_bit(block, bit)
block_t block;
int bit;
{
  /* Insert 'count' bits in the bitmap */
  int w, s;
  short *buf;

  buf = (short *) alloc_block();

  if (block < 0) pexit("insert_bit called with negative argument");
  get_block(block, (char *) buf);
  w = bit / (8 * sizeof(short));
  s = bit % (8 * sizeof(short));
  buf[w] |= (1 << s);
  put_block(block, (char *) buf);

  free(buf);
}


/*================================================================
 *              proto-file processing assist group
 *===============================================================*/
int mode_con(p)
char *p;
{
  /* Convert string to mode */
  int o1, o2, o3, mode;
  char c1, c2, c3;

  c1 = *p++;
  c2 = *p++;
  c3 = *p++;
  o1 = *p++ - '0';
  o2 = *p++ - '0';
  o3 = *p++ - '0';
  mode = (o1 << 6) | (o2 << 3) | o3;
  if (c1 == 'd') mode += I_DIRECTORY;
  if (c1 == 'b') mode += I_BLOCK_SPECIAL;
  if (c1 == 'c') mode += I_CHAR_SPECIAL;
  if (c1 == '-') mode += I_REGULAR;
  if (c2 == 'u') mode += I_SET_UID_BIT;
  if (c3 == 'g') mode += I_SET_GID_BIT;
  return(mode);
}

void getline(line, parse)
char *parse[MAX_TOKENS];
char line[LINE_LEN];
{
  /* Read a line and break it up in tokens */
  int k;
  char c, *p;
  int d;

  for (k = 0; k < MAX_TOKENS; k++) parse[k] = 0;
  for (k = 0; k < LINE_LEN; k++) line[k] = 0;
  k = 0;
  parse[0] = 0;
  p = line;
  while (1) {
        if (++k > LINE_LEN) pexit("Line too long");
        d = fgetc(proto);
        if (d == EOF) pexit("Unexpected end-of-file");
        *p = d;
        if (*p == '\n') lct++;
        if (*p == ' ' || *p == '\t') *p = 0;
        if (*p == '\n') {
                *p++ = 0;
                *p = '\n';
                break;
        }
        p++;
  }

  k = 0;
  p = line;
  lastp = line;
  while (1) {
        c = *p++;
        if (c == '\n') return;
        if (c == 0) continue;
        parse[k++] = p - 1;
        do {
                c = *p++;
        } while (c != 0 && c != '\n');
  }
}


/*================================================================
 *                      other stuff
 *===============================================================*/
void check_mtab(devname)
char *devname;                  /* /dev/hd1 or whatever */
{
/* Check to see if the special file named in s is mounted. */

  int n, r;
  struct stat sb;
  char special[PATH_MAX + 1], mounted_on[PATH_MAX + 1], version[10], rw_flag[10];

  r= stat(devname, &sb);
  if (r == -1)
  {
        if (errno == ENOENT)
                return; /* Does not exist, and therefore not mounted. */
        fprintf(stderr, "%s: stat %s failed: %s\n",
                progname, devname, strerror(errno));
        exit(1);
  }
  if (!S_ISBLK(sb.st_mode))
  {
        /* Not a block device and therefore not mounted. */
        return;
  }

  if (load_mtab("mkfs") < 0) return;
  while (1) {
        n = get_mtab_entry(special, mounted_on, version, rw_flag);
        if (n < 0) return;
        if (strcmp(devname, special) == 0) {
                /* Can't mkfs on top of a mounted file system. */
                fprintf(stderr, "%s: %s is mounted on %s\n",
                        progname, devname, mounted_on);
                exit(1);
        }
  }
}


long file_time(f)
int f;
{
#ifdef UNIX
  struct stat statbuf;
  fstat(f, &statbuf);
  return(statbuf.st_mtime);
#else                           /* fstat not supported by DOS */
  return(0L);
#endif
}


void pexit(s)
char *s;
{
  fprintf(stderr, "%s: %s\n", progname, s);
  if (lct != 0)
        fprintf(stderr, "Line %d being processed when error detected.\n", lct);
  flush();
  exit(2);
}


void copy(from, to, count)
char *from, *to;
int count;
{
  while (count--) *to++ = *from++;
}

char *alloc_block()
{
        char *buf;

        if(!(buf = malloc(block_size))) {
                pexit("couldn't allocate filesystem buffer");
        }
        bzero(buf, block_size);

        return buf;
}

void print_fs()
{
  int i, j;
  ino_t k;
  d1_inode inode1[V1_INODES_PER_BLOCK];
  d2_inode *inode2;
  unsigned short *usbuf;
  block_t b, inode_limit;
  struct direct *dir;

  if(!(inode2 = malloc(V2_INODES_PER_BLOCK(block_size) * sizeof(*inode2))))
        pexit("couldn't allocate a block of inodes");

  if(!(dir = malloc(NR_DIR_ENTRIES(block_size)*sizeof(*dir))))
        pexit("malloc of directory entry failed");

  usbuf = (unsigned short *) alloc_block();

  get_super_block((char *) usbuf);
  printf("\nSuperblock: ");
  for (i = 0; i < 8; i++) printf("%06o ", usbuf[i]);
  get_block((block_t) 2, (char *) usbuf);
  printf("...\nInode map:  ");
  for (i = 0; i < 9; i++) printf("%06o ", usbuf[i]);
  get_block((block_t) 3, (char *) usbuf);
  printf("...\nZone  map:  ");
  for (i = 0; i < 9; i++) printf("%06o ", usbuf[i]);
  printf("...\n");

  free(usbuf);
  usbuf = NULL;

  k = 0;
  for (b = inode_offset; k < nrinodes; b++) {
        if (fs_version == 1) {
                get_block(b, (char *) inode1);
        } else {
                get_block(b, (char *) inode2);
        }
        for (i = 0; i < inodes_per_block; i++) {
                k = inodes_per_block * (int) (b - inode_offset) + i + 1;
                /* Lint but OK */
                if (k > nrinodes) break;
                if (fs_version == 1) {
                        if (inode1[i].d1_mode != 0) {
                                printf("Inode %2d:  mode=", k);
                                printf("%06o", inode1[i].d1_mode);
                                printf("  uid=%2d  gid=%2d  size=",
                                inode1[i].d1_uid, inode1[i].d1_gid);
                                printf("%6ld", inode1[i].d1_size);
                                printf("  zone[0]=%d\n", inode1[i].d1_zone[0]);
                        }
                        if ((inode1[i].d1_mode & I_TYPE) == I_DIRECTORY) {
                                /* This is a directory */
                                get_block(inode1[i].d1_zone[0], (char *) dir);
                                for (j = 0; j < NR_DIR_ENTRIES(block_size); j++)
                                        if (dir[j].d_ino)
                                                printf("\tInode %2d: %s\n", dir[j].d_ino, dir[j].d_name);
                        }
                } else {
                        if (inode2[i].d2_mode != 0) {
                                printf("Inode %2d:  mode=", k);
                                printf("%06o", inode2[i].d2_mode);
                                printf("  uid=%2d  gid=%2d  size=",
                                inode2[i].d2_uid, inode2[i].d2_gid);
                                printf("%6ld", inode2[i].d2_size);
                                printf("  zone[0]=%ld\n", inode2[i].d2_zone[0]);
                        }
                        if ((inode2[i].d2_mode & I_TYPE) == I_DIRECTORY) {
                                /* This is a directory */
                                get_block(inode2[i].d2_zone[0], (char *) dir);
                                for (j = 0; j < NR_DIR_ENTRIES(block_size); j++)
                                        if (dir[j].d_ino)
                                                printf("\tInode %2d: %s\n", dir[j].d_ino, dir[j].d_name);
                        }
                }
        }
  }

  printf("%d inodes used.     %d zones used.\n", next_inode - 1, next_zone);
  free(dir);
  free(inode2);
}


int read_and_set(n)
block_t n;
{
/* The first time a block is read, it returns all 0s, unless there has
 * been a write.  This routine checks to see if a block has been accessed.
 */

  int w, s, mask, r;

  if (sizeof(char *) == 2 && n >= MAX_INIT) pexit("can't initialize past 128M");
  w = n / 8;
  s = n % 8;
  mask = 1 << s;
  r = (umap[w] & mask ? 1 : 0);
  umap[w] |= mask;
  return(r);
}

void usage()
{
  fprintf(stderr,
          "Usage: %s [-12dlot] [-b blocks] [-i inodes] [-B blocksize] special [proto]\n",
          progname);
  exit(1);
}

/*================================================================
 *                    get_block & put_block for MS-DOS
 *===============================================================*/
#ifdef DOS

/*
 *      These are the get_block and put_block routines
 *      when compiling & running mkfs.c under MS-DOS.
 *
 *      It requires the (asembler) routines absread & abswrite
 *      from the file diskio.asm. Since these routines just do
 *      as they are told (read & write the sector specified),
 *      a local cache is used to minimize the i/o-overhead for
 *      frequently used blocks.
 *
 *      The global variable "file" determines whether the output
 *      is to a disk-device or to a binary file.
 */


#define PH_SECTSIZE        512  /* size of a physical disk-sector */


char *derrtab[14] = {
             "no error",
             "disk is read-only",
             "unknown unit",
             "device not ready",
             "bad command",
             "data error",
             "internal error: bad request structure length",
             "seek error",
             "unknown media type",
             "sector not found",
             "printer out of paper (?)",
             "write fault",
             "read error",
             "general error"
};

#define CACHE_SIZE      20      /* 20 block-buffers */


struct cache {
  char blockbuf[BLOCK_SIZE];
  block_t blocknum;
  int dirty;
  int usecnt;
} cache[CACHE_SIZE];


void special(string)
char *string;
{

  if (string[1] == ':' && string[2] == 0) {
        /* Format: d: or d:fname */
        disk = (string[0] & ~32) - 'A';
        if (disk > 1 && !override)      /* safety precaution */
                pexit("Bad drive specifier for special");
  } else {
        file = 1;
        if ((fd = creat(string, BWRITE)) == 0)
                pexit("Can't open special file");
  }
}

void get_block(n, buf)
block_t n;
char *buf;
{
  /* Get a block to the user */
  struct cache *bp, *fp;

  /* First access returns a zero block */
  if (read_and_set(n) == 0) {
        copy(zero, buf, block_size);
        return;
  }

  /* Look for block in cache */
  fp = 0;
  for (bp = cache; bp < &cache[CACHE_SIZE]; bp++) {
        if (bp->blocknum == n) {
                copy(bp, buf, block_size);
                bp->usecnt++;
                return;
        }

        /* Remember clean block */
        if (bp->dirty == 0)
                if (fp) {
                        if (fp->usecnt > bp->usecnt) fp = bp;
                } else
                        fp = bp;
  }

  /* Block not in cache, get it */
  if (!fp) {
        /* No clean buf, flush one */
        for (bp = cache, fp = cache; bp < &cache[CACHE_SIZE]; bp++)
                if (fp->usecnt > bp->usecnt) fp = bp;
        mx_write(fp->blocknum, fp);
  }
  mx_read(n, fp);
  fp->dirty = 0;
  fp->usecnt = 0;
  fp->blocknum = n;
  copy(fp, buf, block_size);
}

void put_block(n, buf)
block_t n;
char *buf;
{   
  /* Accept block from user */
  struct cache *fp, *bp;

  (void) read_and_set(n);

  /* Look for block in cache */
  fp = 0;
  for (bp = cache; bp < &cache[CACHE_SIZE]; bp++) {
        if (bp->blocknum == n) {
                copy(buf, bp, block_size);
                bp->dirty = 1;
                return;
        }

        /* Remember clean block */
        if (bp->dirty == 0)
                if (fp) {
                        if (fp->usecnt > bp->usecnt) fp = bp;
                } else
                        fp = bp;
  }

  /* Block not in cache */
  if (!fp) {
        /* No clean buf, flush one */
        for (bp = cache, fp = cache; bp < &cache[CACHE_SIZE]; bp++)
                if (fp->usecnt > bp->usecnt) fp = bp;
        mx_write(fp->blocknum, fp);
  }
  fp->dirty = 1;
  fp->usecnt = 1;
  fp->blocknum = n;
  copy(buf, fp, block_size);
}

void cache_init()
{
  struct cache *bp;
  for (bp = cache; bp < &cache[CACHE_SIZE]; bp++) bp->blocknum = -1;
}

void flush()
{
  /* Flush all dirty blocks to disk */
  struct cache *bp;

  for (bp = cache; bp < &cache[CACHE_SIZE]; bp++)
        if (bp->dirty) {
                mx_write(bp->blocknum, bp);
                bp->dirty = 0;
        }
}

/*==================================================================
 *                      hard read & write etc.
 *=================================================================*/
#define MAX_RETRIES     5


void mx_read(blocknr, buf)
int blocknr;
char *buf;
{

  /* Read the requested MINIX-block in core */
  char (*bp)[PH_SECTSIZE];
  int sectnum, retries, err;

  if (file) {
        lseek(fd, (off_t) blocknr * block_size, 0);
        if (read(fd, buf, block_size) != block_size)
                pexit("mx_read: error reading file");
  } else {
        sectnum = blocknr * (block_size / PH_SECTSIZE);
        for (bp = buf; bp < &buf[block_size]; bp++) {
                retries = MAX_RETRIES;
                do
                        err = absread(disk, sectnum, bp);
                while (err && --retries);

                if (retries) {
                        sectnum++;
                } else {
                        dexit("mx_read", sectnum, err);
                }
        }
  }
}

void mx_write(blocknr, buf)
int blocknr;
char *buf;
{
  /* Write the MINIX-block to disk */
  char (*bp)[PH_SECTSIZE];
  int retries, sectnum, err;

  if (file) {
        lseek(fd, blocknr * block_size, 0);
        if (write(fd, buf, block_size) != block_size) {
                pexit("mx_write: error writing file");
        }
  } else {
        sectnum = blocknr * (block_size / PH_SECTSIZE);
        for (bp = buf; bp < &buf[block_size]; bp++) {
                retries = MAX_RETRIES;
                do {
                        err = abswrite(disk, sectnum, bp);
                } while (err && --retries);

                if (retries) {
                        sectnum++;
                } else {
                        dexit("mx_write", sectnum, err);
                }
        }
  }
}


void dexit(s, sectnum, err)
int sectnum, err;
char *s;
{
  printf("Error: %s, sector: %d, code: %d, meaning: %s\n",
         s, sectnum, err, derrtab[err]);
  exit(2);
}

#endif

/*================================================================
 *                    get_block & put_block for UNIX
 *===============================================================*/
#ifdef UNIX

void special(string)
char *string;
{
  fd = creat(string, 0777);
  close(fd);
  fd = open(string, O_RDWR);
  if (fd < 0) pexit("Can't open special file");
#if (MACHINE == ATARI)
  {
        struct stat statbuf;

        if (fstat(fd, &statbuf) < 0) return;
        isdev = (statbuf.st_mode & S_IFMT) == S_IFCHR
                ||
                (statbuf.st_mode & S_IFMT) == S_IFBLK
                ;
  }
#endif
}



void get_block(n, buf)
block_t n;
char *buf;
{
/* Read a block. */

  int k;

  /* First access returns a zero block */
  if (read_and_set(n) == 0) {
        copy(zero, buf, block_size);
        return;
  }
  lseek(fd, (off_t) n * block_size, SEEK_SET);
  k = read(fd, buf, block_size);
  if (k != block_size) {
        pexit("get_block couldn't read");
  }
}

void get_super_block(buf)
char *buf;
{
/* Read a block. */

  int k;

  if(lseek(fd, (off_t) SUPER_BLOCK_BYTES, SEEK_SET) < 0) {
        perror("lseek");
        pexit("seek failed");
  }
  k = read(fd, buf, _STATIC_BLOCK_SIZE);
  if (k != _STATIC_BLOCK_SIZE) {
        pexit("get_super_block couldn't read");
  }
}

void put_block(n, buf)
block_t n;
char *buf;
{
/* Write a block. */

  (void) read_and_set(n);

  /* XXX - check other lseeks too. */
  if (lseek(fd, (off_t) n * block_size, SEEK_SET) == (off_t) -1) {
        pexit("put_block couldn't seek");
  }
  if (write(fd, buf, block_size) != block_size) {
        pexit("put_block couldn't write");
  }
}


/* Dummy routines to keep source file clean from #ifdefs */

void flush()
{
  return;
}

void cache_init()
{
  return;
}

#endif

---