static int st_int_ioctl()

in st.c [2693:3093]


static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned long arg)
{
	int timeout;
	long ltmp;
	int ioctl_result;
	int chg_eof = 1;
	unsigned char cmd[MAX_COMMAND_SIZE];
	struct st_request *SRpnt;
	struct st_partstat *STps;
	int fileno, blkno, at_sm, undone;
	int datalen = 0, direction = DMA_NONE;

	WARN_ON(STp->buffer->do_dio != 0);
	if (STp->ready != ST_READY) {
		if (STp->ready == ST_NO_TAPE)
			return (-ENOMEDIUM);
		else
			return (-EIO);
	}
	timeout = STp->long_timeout;
	STps = &(STp->ps[STp->partition]);
	fileno = STps->drv_file;
	blkno = STps->drv_block;
	at_sm = STps->at_sm;

	memset(cmd, 0, MAX_COMMAND_SIZE);
	switch (cmd_in) {
	case MTFSFM:
		chg_eof = 0;	/* Changed from the FSF after this */
		fallthrough;
	case MTFSF:
		cmd[0] = SPACE;
		cmd[1] = 0x01;	/* Space FileMarks */
		cmd[2] = (arg >> 16);
		cmd[3] = (arg >> 8);
		cmd[4] = arg;
		deb_space_print(STp, ST_DEB_FORWARD, "filemarks", cmd);
		if (fileno >= 0)
			fileno += arg;
		blkno = 0;
		at_sm &= (arg == 0);
		break;
	case MTBSFM:
		chg_eof = 0;	/* Changed from the FSF after this */
		fallthrough;
	case MTBSF:
		cmd[0] = SPACE;
		cmd[1] = 0x01;	/* Space FileMarks */
		ltmp = (-arg);
		cmd[2] = (ltmp >> 16);
		cmd[3] = (ltmp >> 8);
		cmd[4] = ltmp;
		deb_space_print(STp, ST_DEB_BACKWARD, "filemarks", cmd);
		if (fileno >= 0)
			fileno -= arg;
		blkno = (-1);	/* We can't know the block number */
		at_sm &= (arg == 0);
		break;
	case MTFSR:
		cmd[0] = SPACE;
		cmd[1] = 0x00;	/* Space Blocks */
		cmd[2] = (arg >> 16);
		cmd[3] = (arg >> 8);
		cmd[4] = arg;
		deb_space_print(STp, ST_DEB_FORWARD, "blocks", cmd);
		if (blkno >= 0)
			blkno += arg;
		at_sm &= (arg == 0);
		break;
	case MTBSR:
		cmd[0] = SPACE;
		cmd[1] = 0x00;	/* Space Blocks */
		ltmp = (-arg);
		cmd[2] = (ltmp >> 16);
		cmd[3] = (ltmp >> 8);
		cmd[4] = ltmp;
		deb_space_print(STp, ST_DEB_BACKWARD, "blocks", cmd);
		if (blkno >= 0)
			blkno -= arg;
		at_sm &= (arg == 0);
		break;
	case MTFSS:
		cmd[0] = SPACE;
		cmd[1] = 0x04;	/* Space Setmarks */
		cmd[2] = (arg >> 16);
		cmd[3] = (arg >> 8);
		cmd[4] = arg;
		deb_space_print(STp, ST_DEB_FORWARD, "setmarks", cmd);
		if (arg != 0) {
			blkno = fileno = (-1);
			at_sm = 1;
		}
		break;
	case MTBSS:
		cmd[0] = SPACE;
		cmd[1] = 0x04;	/* Space Setmarks */
		ltmp = (-arg);
		cmd[2] = (ltmp >> 16);
		cmd[3] = (ltmp >> 8);
		cmd[4] = ltmp;
		deb_space_print(STp, ST_DEB_BACKWARD, "setmarks", cmd);
		if (arg != 0) {
			blkno = fileno = (-1);
			at_sm = 1;
		}
		break;
	case MTWEOF:
	case MTWEOFI:
	case MTWSM:
		if (STp->write_prot)
			return (-EACCES);
		cmd[0] = WRITE_FILEMARKS;
		if (cmd_in == MTWSM)
			cmd[1] = 2;
		if (cmd_in == MTWEOFI ||
		    (cmd_in == MTWEOF && STp->immediate_filemark))
			cmd[1] |= 1;
		cmd[2] = (arg >> 16);
		cmd[3] = (arg >> 8);
		cmd[4] = arg;
		timeout = STp->device->request_queue->rq_timeout;
		DEBC(
			if (cmd_in != MTWSM)
				st_printk(ST_DEB_MSG, STp,
					  "Writing %d filemarks.\n",
					  cmd[2] * 65536 +
					  cmd[3] * 256 +
					  cmd[4]);
			else
				st_printk(ST_DEB_MSG, STp,
					  "Writing %d setmarks.\n",
					  cmd[2] * 65536 +
					  cmd[3] * 256 +
					  cmd[4]);
		)
		if (fileno >= 0)
			fileno += arg;
		blkno = 0;
		at_sm = (cmd_in == MTWSM);
		break;
	case MTREW:
		cmd[0] = REZERO_UNIT;
		if (STp->immediate) {
			cmd[1] = 1;	/* Don't wait for completion */
			timeout = STp->device->request_queue->rq_timeout;
		}
		DEBC_printk(STp, "Rewinding tape.\n");
		fileno = blkno = at_sm = 0;
		break;
	case MTNOP:
		DEBC_printk(STp, "No op on tape.\n");
		return 0;	/* Should do something ? */
	case MTRETEN:
		cmd[0] = START_STOP;
		if (STp->immediate) {
			cmd[1] = 1;	/* Don't wait for completion */
			timeout = STp->device->request_queue->rq_timeout;
		}
		cmd[4] = 3;
		DEBC_printk(STp, "Retensioning tape.\n");
		fileno = blkno = at_sm = 0;
		break;
	case MTEOM:
		if (!STp->fast_mteom) {
			/* space to the end of tape */
			ioctl_result = st_int_ioctl(STp, MTFSF, 0x7fffff);
			fileno = STps->drv_file;
			if (STps->eof >= ST_EOD_1)
				return 0;
			/* The next lines would hide the number of spaced FileMarks
			   That's why I inserted the previous lines. I had no luck
			   with detecting EOM with FSF, so we go now to EOM.
			   Joerg Weule */
		} else
			fileno = (-1);
		cmd[0] = SPACE;
		cmd[1] = 3;
		DEBC_printk(STp, "Spacing to end of recorded medium.\n");
		blkno = -1;
		at_sm = 0;
		break;
	case MTERASE:
		if (STp->write_prot)
			return (-EACCES);
		cmd[0] = ERASE;
		cmd[1] = (arg ? 1 : 0);	/* Long erase with non-zero argument */
		if (STp->immediate) {
			cmd[1] |= 2;	/* Don't wait for completion */
			timeout = STp->device->request_queue->rq_timeout;
		}
		else
			timeout = STp->long_timeout * 8;

		DEBC_printk(STp, "Erasing tape.\n");
		fileno = blkno = at_sm = 0;
		break;
	case MTSETBLK:		/* Set block length */
	case MTSETDENSITY:	/* Set tape density */
	case MTSETDRVBUFFER:	/* Set drive buffering */
	case SET_DENS_AND_BLK:	/* Set density and block size */
		chg_eof = 0;
		if (STp->dirty || (STp->buffer)->buffer_bytes != 0)
			return (-EIO);	/* Not allowed if data in buffer */
		if ((cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) &&
		    (arg & MT_ST_BLKSIZE_MASK) != 0 &&
		    STp->max_block > 0 &&
		    ((arg & MT_ST_BLKSIZE_MASK) < STp->min_block ||
		     (arg & MT_ST_BLKSIZE_MASK) > STp->max_block)) {
			st_printk(KERN_WARNING, STp, "Illegal block size.\n");
			return (-EINVAL);
		}
		cmd[0] = MODE_SELECT;
		if ((STp->use_pf & USE_PF))
			cmd[1] = MODE_SELECT_PAGE_FORMAT;
		cmd[4] = datalen = 12;
		direction = DMA_TO_DEVICE;

		memset((STp->buffer)->b_data, 0, 12);
		if (cmd_in == MTSETDRVBUFFER)
			(STp->buffer)->b_data[2] = (arg & 7) << 4;
		else
			(STp->buffer)->b_data[2] =
			    STp->drv_buffer << 4;
		(STp->buffer)->b_data[3] = 8;	/* block descriptor length */
		if (cmd_in == MTSETDENSITY) {
			(STp->buffer)->b_data[4] = arg;
			STp->density_changed = 1;	/* At least we tried ;-) */
		} else if (cmd_in == SET_DENS_AND_BLK)
			(STp->buffer)->b_data[4] = arg >> 24;
		else
			(STp->buffer)->b_data[4] = STp->density;
		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
			ltmp = arg & MT_ST_BLKSIZE_MASK;
			if (cmd_in == MTSETBLK)
				STp->blksize_changed = 1; /* At least we tried ;-) */
		} else
			ltmp = STp->block_size;
		(STp->buffer)->b_data[9] = (ltmp >> 16);
		(STp->buffer)->b_data[10] = (ltmp >> 8);
		(STp->buffer)->b_data[11] = ltmp;
		timeout = STp->device->request_queue->rq_timeout;
		DEBC(
			if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK)
				st_printk(ST_DEB_MSG, STp,
					  "Setting block size to %d bytes.\n",
					  (STp->buffer)->b_data[9] * 65536 +
					  (STp->buffer)->b_data[10] * 256 +
					  (STp->buffer)->b_data[11]);
			if (cmd_in == MTSETDENSITY || cmd_in == SET_DENS_AND_BLK)
				st_printk(ST_DEB_MSG, STp,
					  "Setting density code to %x.\n",
					  (STp->buffer)->b_data[4]);
			if (cmd_in == MTSETDRVBUFFER)
				st_printk(ST_DEB_MSG, STp,
					  "Setting drive buffer code to %d.\n",
					  ((STp->buffer)->b_data[2] >> 4) & 7);
		)
		break;
	default:
		return (-ENOSYS);
	}

	SRpnt = st_do_scsi(NULL, STp, cmd, datalen, direction,
			   timeout, MAX_RETRIES, 1);
	if (!SRpnt)
		return (STp->buffer)->syscall_result;

	ioctl_result = (STp->buffer)->syscall_result;

	if (!ioctl_result) {	/* SCSI command successful */
		st_release_request(SRpnt);
		SRpnt = NULL;
		STps->drv_block = blkno;
		STps->drv_file = fileno;
		STps->at_sm = at_sm;

		if (cmd_in == MTBSFM)
			ioctl_result = st_int_ioctl(STp, MTFSF, 1);
		else if (cmd_in == MTFSFM)
			ioctl_result = st_int_ioctl(STp, MTBSF, 1);

		if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) {
			STp->block_size = arg & MT_ST_BLKSIZE_MASK;
			if (STp->block_size != 0) {
				(STp->buffer)->buffer_blocks =
				    (STp->buffer)->buffer_size / STp->block_size;
			}
			(STp->buffer)->buffer_bytes = (STp->buffer)->read_pointer = 0;
			if (cmd_in == SET_DENS_AND_BLK)
				STp->density = arg >> MT_ST_DENSITY_SHIFT;
		} else if (cmd_in == MTSETDRVBUFFER)
			STp->drv_buffer = (arg & 7);
		else if (cmd_in == MTSETDENSITY)
			STp->density = arg;

		if (cmd_in == MTEOM)
			STps->eof = ST_EOD;
		else if (cmd_in == MTFSF)
			STps->eof = ST_FM;
		else if (chg_eof)
			STps->eof = ST_NOEOF;

		if (cmd_in == MTWEOF || cmd_in == MTWEOFI)
			STps->rw = ST_IDLE;  /* prevent automatic WEOF at close */
	} else { /* SCSI command was not completely successful. Don't return
                    from this block without releasing the SCSI command block! */
		struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;

		if (cmdstatp->flags & SENSE_EOM) {
			if (cmd_in != MTBSF && cmd_in != MTBSFM &&
			    cmd_in != MTBSR && cmd_in != MTBSS)
				STps->eof = ST_EOM_OK;
			STps->drv_block = 0;
		}

		if (cmdstatp->remainder_valid)
			undone = (int)cmdstatp->uremainder64;
		else
			undone = 0;

		if ((cmd_in == MTWEOF || cmd_in == MTWEOFI) &&
		    cmdstatp->have_sense &&
		    (cmdstatp->flags & SENSE_EOM)) {
			if (cmdstatp->sense_hdr.sense_key == NO_SENSE ||
			    cmdstatp->sense_hdr.sense_key == RECOVERED_ERROR) {
				ioctl_result = 0;	/* EOF(s) written successfully at EOM */
				STps->eof = ST_NOEOF;
			} else {  /* Writing EOF(s) failed */
				if (fileno >= 0)
					fileno -= undone;
				if (undone < arg)
					STps->eof = ST_NOEOF;
			}
			STps->drv_file = fileno;
		} else if ((cmd_in == MTFSF) || (cmd_in == MTFSFM)) {
			if (fileno >= 0)
				STps->drv_file = fileno - undone;
			else
				STps->drv_file = fileno;
			STps->drv_block = -1;
			STps->eof = ST_NOEOF;
		} else if ((cmd_in == MTBSF) || (cmd_in == MTBSFM)) {
			if (arg > 0 && undone < 0)  /* Some drives get this wrong */
				undone = (-undone);
			if (STps->drv_file >= 0)
				STps->drv_file = fileno + undone;
			STps->drv_block = 0;
			STps->eof = ST_NOEOF;
		} else if (cmd_in == MTFSR) {
			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
				if (STps->drv_file >= 0)
					STps->drv_file++;
				STps->drv_block = 0;
				STps->eof = ST_FM;
			} else {
				if (blkno >= undone)
					STps->drv_block = blkno - undone;
				else
					STps->drv_block = (-1);
				STps->eof = ST_NOEOF;
			}
		} else if (cmd_in == MTBSR) {
			if (cmdstatp->flags & SENSE_FMK) {	/* Hit filemark */
				STps->drv_file--;
				STps->drv_block = (-1);
			} else {
				if (arg > 0 && undone < 0)  /* Some drives get this wrong */
					undone = (-undone);
				if (STps->drv_block >= 0)
					STps->drv_block = blkno + undone;
			}
			STps->eof = ST_NOEOF;
		} else if (cmd_in == MTEOM) {
			STps->drv_file = (-1);
			STps->drv_block = (-1);
			STps->eof = ST_EOD;
		} else if (cmd_in == MTSETBLK ||
			   cmd_in == MTSETDENSITY ||
			   cmd_in == MTSETDRVBUFFER ||
			   cmd_in == SET_DENS_AND_BLK) {
			if (cmdstatp->sense_hdr.sense_key == ILLEGAL_REQUEST &&
			    !(STp->use_pf & PF_TESTED)) {
				/* Try the other possible state of Page Format if not
				   already tried */
				STp->use_pf = (STp->use_pf ^ USE_PF) | PF_TESTED;
				st_release_request(SRpnt);
				SRpnt = NULL;
				return st_int_ioctl(STp, cmd_in, arg);
			}
		} else if (chg_eof)
			STps->eof = ST_NOEOF;

		if (cmdstatp->sense_hdr.sense_key == BLANK_CHECK)
			STps->eof = ST_EOD;

		st_release_request(SRpnt);
		SRpnt = NULL;
	}

	return ioctl_result;
}