mt.c

来自「mt 是linux下得磁带机」· C语言 代码 · 共 713 行 · 第 1/2 页

	if (i) {
	    if (errno == ENOSYS)
		fprintf(stderr, "mt: Command not supported by this kernel.\n");
	    else if (comp->error_tests != 0)
		test_error(mtfd, comp);
	}
    }
    else {
	fprintf(stderr, "mt: Internal error: command without function.\n");
	i = 1;
    }

    if (mtfd >= 0)
	close(mtfd);
    return i;
}


	static void
usage(int explain)
{
    int ind;
    char line[100];

    fprintf(stderr, "usage: mt [-v] [--version] [-h] [ -f device ] command [ count ]\n");
    if (explain) {
	for (ind=0; cmds[ind].cmd_name != NULL; ) {
	    if (ind == 0)
		strcpy(line, "commands: ");
	    else
		strcpy(line, "          ");
	    for ( ; cmds[ind].cmd_name != NULL; ind++) {
		strcat(line, cmds[ind].cmd_name);
		if (cmds[ind+1].cmd_name != NULL)
		    strcat(line, ", ");
		else
		    strcat(line, ".");
		if (strlen(line) >= 70 || cmds[ind+1].cmd_name == NULL) {
		    fprintf(stderr, "%s\n", line);
		    ind++;
		    break;
		}
	    }
	}
    }
}



/* Do a command that simply feeds an argument to the MTIOCTOP ioctl */
	static int
do_standard(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtop mt_com;
    char *endp;

    mt_com.mt_op = cmd->cmd_code;
    mt_com.mt_count = (argc > 0 ? strtol(*argv, &endp, 0) : 1);
    if (argc > 0 && endp != *argv) {
	if (*endp == 'k')
	    mt_com.mt_count *= 1024;
	else if (*endp == 'M')
	    mt_com.mt_count *= 1024 * 1024;
	else if (*endp == 'G')
	    mt_com.mt_count *= 1024 * 1024 * 1024;
    }
    mt_com.mt_count |= cmd->cmd_count_bits;
    if (mt_com.mt_count < 0) {
	fprintf(stderr, "mt: negative repeat count\n");
	return 1;
    }
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    return 0;
}


/* The the drive buffering and other things with this (highly overloaded)
   ioctl function. (See also do_options below.) */
	static int
do_drvbuffer(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtop mt_com;

    mt_com.mt_op = MTSETDRVBUFFER;
    mt_com.mt_count = (argc > 0 ? strtol(*argv, NULL, 0) : 1);
    if ((cmd->cmd_count_bits & MT_ST_OPTIONS) == MT_ST_DEF_OPTIONS)
	mt_com.mt_count &= 0xfffff;
#ifdef MT_ST_TIMEOUTS
    else if ((cmd->cmd_count_bits & MT_ST_OPTIONS) == MT_ST_TIMEOUTS)
	mt_com.mt_count &= 0x7ffffff;
#endif
    else
	mt_com.mt_count &= 0xfffffff;
    mt_com.mt_count |= cmd->cmd_count_bits;
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    return 0;
}


/* Set the tape driver options */
	static int
do_options(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    int i, an, len;
    struct mtop mt_com;

    mt_com.mt_op = MTSETDRVBUFFER;
    if (argc == 0)
	mt_com.mt_count = 0;
    else if (isdigit(**argv))
	mt_com.mt_count = strtol(*argv, NULL, 0) & ~MT_ST_OPTIONS;
    else
	for (an = 0, mt_com.mt_count = 0; an < argc; an++) {
	    len = strlen(argv[an]);
	    for (i=0; boolean_tbl[i].name != NULL; i++)
		if (!strncmp(boolean_tbl[i].name, argv[an], len)) {
		    mt_com.mt_count |= boolean_tbl[i].bitmask;
		    break;
		}
	    if (boolean_tbl[i].name == NULL) {
		fprintf(stderr, "Illegal property name '%s'.\n", argv[an]);
		fprintf(stderr, "The implemented property names are:\n");
		for (i=0; boolean_tbl[i].name != NULL; i++)
		    fprintf(stderr, "  %9s -> %s\n", boolean_tbl[i].name,
			    boolean_tbl[i].expl);
		return 1;
	    }
	    if (len != strlen(boolean_tbl[i].name))
		for (i++ ; boolean_tbl[i].name != NULL; i++)
		    if (!strncmp(boolean_tbl[i].name, argv[an], len)) {
			fprintf(stderr, "Property name '%s' ambiguous.\n",
				argv[an]);
			return 1;
		    }
	}

    switch (cmd->cmd_code) {
    case DO_BOOLEANS:
	mt_com.mt_count |= MT_ST_BOOLEANS;
	break;
    case SET_BOOLEANS:
	mt_com.mt_count |= MT_ST_SETBOOLEANS;
	break;
    case CLEAR_BOOLEANS:
	mt_com.mt_count |= MT_ST_CLEARBOOLEANS;
	break;
    }
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    return 0;
}


/* Tell where the tape is */
	static int
do_tell(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtpos mt_pos;

    if (ioctl(mtfd, MTIOCPOS, (char *)&mt_pos) < 0) {
	perror(tape_name);
	return 2;
    }
    printf("At block %ld.\n", mt_pos.mt_blkno);
    return 0;
}


/* Position the tape to a specific location within a specified partition */
	static int
do_partseek(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtop mt_com;

    mt_com.mt_op = MTSETPART;
    mt_com.mt_count = (argc > 0 ? strtol(*argv, NULL, 0) : 0);
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    mt_com.mt_op = MTSEEK;
    mt_com.mt_count = (argc > 1 ? strtol(argv[1], NULL, 0) : 0);
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    return 0;
}


/* Position to start of file n. This might be implemented more intelligently
   some day. */
	static int
do_asf(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtop mt_com;

    mt_com.mt_op = MTREW;
    mt_com.mt_count = 1;
    if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	perror(tape_name);
	return 2;
    }
    mt_com.mt_count = (argc > 0 ? strtol(*argv, NULL, 0) : 0);
    if (mt_com.mt_count > 0) {
	mt_com.mt_op = MTFSF;
	if (ioctl(mtfd, MTIOCTOP, (char *)&mt_com) < 0) {
	    perror(tape_name);
	    return 2;
	}
    }
    return 0;
}


/*** Decipher the status ***/

	static int
do_status(int mtfd, cmdef_tr *cmd, int argc, char **argv)
{
    struct mtget status;
    int dens, i;
    char *type, *density;

    if (ioctl(mtfd, MTIOCGET, (char *)&status) < 0) {
	perror(tape_name);
	return 2;
    }

    if (status.mt_type == MT_ISSCSI1)
	type = "SCSI 1";
    else if (status.mt_type == MT_ISSCSI2)
	type = "SCSI 2";
    else if (status.mt_type == MT_ISONSTREAM_SC)
	type = "OnStream SC-, DI-, DP-, or USB";
    else
	type = NULL;
    if (type == NULL) {
	if (status.mt_type & 0x800000)
	    printf ("qic-117 drive type = 0x%05lx\n", status.mt_type & 0x1ffff);
	else if (status.mt_type == 0)
	    printf("IDE-Tape (type code 0) ?\n");
	else
	    printf("Unknown tape drive type (type code %ld)\n", status.mt_type);
	printf("File number=%d, block number=%d.\n",
	       status.mt_fileno, status.mt_blkno);
	printf("mt_resid: %ld, mt_erreg: 0x%lx\n",
	       status.mt_resid, status.mt_erreg);
	printf("mt_dsreg: 0x%lx, mt_gstat: 0x%lx\n",
	       status.mt_dsreg, status.mt_gstat);
    }
    else {
	printf("%s tape drive:\n", type);
	if (status.mt_type == MT_ISSCSI2)
	    printf("File number=%d, block number=%d, partition=%ld.\n",
		   status.mt_fileno, status.mt_blkno, (status.mt_resid & 0xff));
	else
	    printf("File number=%d, block number=%d.\n",
		   status.mt_fileno, status.mt_blkno);
	if (status.mt_type == MT_ISSCSI1 ||
	    status.mt_type == MT_ISSCSI2 ||
	    status.mt_type == MT_ISONSTREAM_SC) {
	    dens = (status.mt_dsreg & MT_ST_DENSITY_MASK) >> MT_ST_DENSITY_SHIFT;
	    density = "no translation";
	    for (i=0; i < NBR_DENSITIES; i++)
		if (density_tbl[i].code == dens) {
		    density = density_tbl[i].name;
		    break;
		}
	    printf("Tape block size %ld bytes. Density code 0x%x (%s).\n",
		   ((status.mt_dsreg & MT_ST_BLKSIZE_MASK) >> MT_ST_BLKSIZE_SHIFT),
		   dens, density);

	    printf("Soft error count since last status=%ld\n",
		   (status.mt_erreg & MT_ST_SOFTERR_MASK) >> MT_ST_SOFTERR_SHIFT);
	}
    }

    printf("General status bits on (%lx):\n", status.mt_gstat);
    if (GMT_EOF(status.mt_gstat))
	printf(" EOF");
    if (GMT_BOT(status.mt_gstat))
	printf(" BOT");
    if (GMT_EOT(status.mt_gstat))
	printf(" EOT");
    if (GMT_SM(status.mt_gstat))
	printf(" SM");
    if (GMT_EOD(status.mt_gstat))
	printf(" EOD");
    if (GMT_WR_PROT(status.mt_gstat))
	printf(" WR_PROT");
    if (GMT_ONLINE(status.mt_gstat))
	printf(" ONLINE");
    if (GMT_D_6250(status.mt_gstat))
	printf(" D_6250");
    if (GMT_D_1600(status.mt_gstat))
	printf(" D_1600");
    if (GMT_D_800(status.mt_gstat))
	printf(" D_800");
    if (GMT_DR_OPEN(status.mt_gstat))
	printf(" DR_OPEN");	  
    if (GMT_IM_REP_EN(status.mt_gstat))
	printf(" IM_REP_EN");
    if (GMT_CLN(status.mt_gstat))
	printf(" CLN");
    printf("\n");
    return 0;
}


/* Print a list of possible density codes */
	static int
print_densities(int fd, cmdef_tr *cmd, int argc, char **argv)
{
    int i, offset;

    printf("Some SCSI tape density codes:\ncode   explanation                   code   explanation\n");
    offset = (NBR_DENSITIES + 1) / 2;
    for (i=0; i < offset; i++) {
	printf("0x%02x   %-28s", density_tbl[i].code, density_tbl[i].name);
	if (i + offset < NBR_DENSITIES)
	    printf("  0x%02x   %s\n", density_tbl[i + offset].code, density_tbl[i + offset].name);
	else
	    printf("\n");
    }
    return 0;
}


/* Try to find out why the command failed */
	static void
test_error(int mtfd, cmdef_tr *cmd)
{
    struct mtget status;

    if (ioctl(mtfd, MTIOCGET, (char *)&status) < 0)
	return;

    if (status.mt_type != MT_ISSCSI1 && status.mt_type != MT_ISSCSI2)
	return;

    if ((cmd->error_tests & ET_ONLINE) && !GMT_ONLINE(status.mt_gstat))
	fprintf(stderr, "mt: The device is offline (not powered on, no tape ?).\n");
    if ((cmd->error_tests & ET_WPROT) && !GMT_WR_PROT(status.mt_gstat))
	fprintf(stderr, "mt: The tape is write-protected.\n");
}