zftape-ctl.c

linux-2.6.15.6

	TRACE_EXIT result;
} 

/*  Sets the new blocksize in BYTES
 *
 */
static int mt_setblk(int *new_size)
{
	TRACE_FUN(ft_t_flow);
	
	if((unsigned int)(*new_size) > ZFT_MAX_BLK_SZ) {
		TRACE_ABORT(-EINVAL, ft_t_info,
			    "desired blk_sz (%d) should be <= %d bytes",
			    *new_size, ZFT_MAX_BLK_SZ);
	}
	if ((*new_size & (FT_SECTOR_SIZE-1)) != 0) {
		TRACE_ABORT(-EINVAL, ft_t_info,
			"desired blk_sz (%d) must be a multiple of %d bytes",
			    *new_size, FT_SECTOR_SIZE);
	}
	if (*new_size == 0) {
		if (zft_use_compression) {
			TRACE_ABORT(-EINVAL, ft_t_info,
				    "Variable block size not yet "
				    "supported with compression");
		}
		*new_size = 1;
	}
	zft_blk_sz = *new_size;
	TRACE_EXIT 0;
} 

static int mt_setdensity(int *arg)
{
	TRACE_FUN(ft_t_flow);
	
	SET_TRACE_LEVEL(*arg);
	TRACE(TRACE_LEVEL, "tracing set to %d", TRACE_LEVEL);
	if ((int)TRACE_LEVEL != *arg) {
		TRACE_EXIT -EINVAL;
	}
	TRACE_EXIT 0;
}          

static int mt_seek(int *new_block_pos)
{ 
	int result= 0;        
	TRACE_FUN(ft_t_any);
	
	result = seek_block(0, (__s64)*new_block_pos, &zft_pos);
	TRACE_EXIT result;
}

/*  OK, this is totally different from SCSI, but the worst thing that can 
 *  happen is that there is not enough defragmentated memory that can be 
 *  allocated. Also, there is a hardwired limit of 16 dma buffers in the 
 *  stock ftape module. This shouldn't bring the system down.
 *
 * NOTE: the argument specifies the total number of dma buffers to use.
 *       The driver needs at least 3 buffers to function at all.
 * 
 */
static int mt_setdrvbuffer(int *cnt)
{
	TRACE_FUN(ft_t_flow);

	if (*cnt < 3) {
		TRACE_EXIT -EINVAL;
	}
	TRACE_CATCH(ftape_set_nr_buffers(*cnt),);
	TRACE_EXIT 0;
}
/* return the block position from start of volume 
 */
static int mt_tell(int *arg)
{
	TRACE_FUN(ft_t_flow);
	
	*arg   = zft_div_blksz(zft_pos.volume_pos,
			       zft_find_volume(zft_pos.seg_pos)->blk_sz);
	TRACE_EXIT 0;
}

static int mt_compression(int *arg)
{
	TRACE_FUN(ft_t_flow);
	
	/*  Ok. We could also check whether compression is available at
	 *  all by trying to load the compression module.  We could
	 *  also check for a block size of 1 byte which is illegal
	 *  with compression.  Instead of doing it here we rely on
	 *  zftape_write() to do the proper checks.
	 */
	if ((unsigned int)*arg > 1) {
		TRACE_EXIT -EINVAL;
	}
	if (*arg != 0 && zft_blk_sz == 1) { /* variable block size */
		TRACE_ABORT(-EINVAL, ft_t_info,
			    "Compression not yet supported "
			    "with variable block size");
	}
	zft_mt_compression  = *arg;
	if ((zft_unit & ZFT_ZIP_MODE) == 0) {
		zft_use_compression = zft_mt_compression;
	}
	TRACE_EXIT 0;
}

/*  check whether write access is allowed. Write access is denied when
 *  + zft_write_protected == 1 -- this accounts for either hard write 
 *                                protection of the cartridge or for 
 *                                O_RDONLY access mode of the tape device
 *  + zft_offline == 1         -- this meany that there is either no tape 
 *                                or that the MTOFFLINE ioctl has been 
 *                                previously issued (`soft eject')
 *  + ft_formatted == 0        -- this means that the cartridge is not
 *                                formatted
 *  Then we distinuguish two cases. When zft_qic_mode is TRUE, then we try
 *  to emulate a `traditional' (aka SCSI like) UN*X tape device. Therefore we
 *  deny writes when
 *  + zft_qic_mode ==1 && 
 *       (!zft_tape_at_lbot() &&   -- tape no at logical BOT
 *        !(zft_tape_at_eom() ||   -- tape not at logical EOM (or EOD)
 *          (zft_tape_at_eom() &&
 *           zft_old_ftape())))    -- we can't add new volume to tapes 
 *                                    written by old ftape because ftape
 *                                    don't use the volume table
 *
 *  when the drive is in true raw mode (aka /dev/rawft0) then we don't 
 *  care about LBOT and EOM conditions. This device is intended for a 
 *  user level program that wants to truly implement the QIC-80 compliance
 *  at the logical data layout level of the cartridge, i.e. implement all
 *  that volume table and volume directory stuff etc.<
 */
int zft_check_write_access(zft_position *pos)
{
	TRACE_FUN(ft_t_flow);

	if (zft_offline) { /* offline includes no_tape */
		TRACE_ABORT(-ENXIO,
			    ft_t_info, "tape is offline or no cartridge");
	}
	if (!ft_formatted) {
		TRACE_ABORT(-EACCES, ft_t_info, "tape is not formatted");
	} 
	if (zft_write_protected) {
		TRACE_ABORT(-EACCES, ft_t_info, "cartridge write protected");
	} 
	if (zft_qic_mode) {
		/*  check BOT condition */
		if (!zft_tape_at_lbot(pos)) {
			/*  protect cartridges written by old ftape if
			 *  not at BOT because they use the vtbl
			 *  segment for storing data
			 */
			if (zft_old_ftape) {
				TRACE_ABORT(-EACCES, ft_t_warn, 
      "Cannot write to cartridges written by old ftape when not at BOT");
			}
			/*  not at BOT, but allow writes at EOD, of course
			 */
			if (!zft_tape_at_eod(pos)) {
				TRACE_ABORT(-EACCES, ft_t_info,
					    "tape not at BOT and not at EOD");
			}
		}
		/*  fine. Now the tape is either at BOT or at EOD. */
	}
	/* or in raw mode in which case we don't care about BOT and EOD */
	TRACE_EXIT 0;
}

/*      OPEN routine called by kernel-interface code
 *
 *      NOTE: this is also called by mt_reset() with dev_minor == -1
 *            to fake a reopen after a reset.
 */
int _zft_open(unsigned int dev_minor, unsigned int access_mode)
{
	static unsigned int tape_unit;
	static unsigned int file_access_mode;
	int result;
	TRACE_FUN(ft_t_flow);

	if ((int)dev_minor == -1) {
		/* fake reopen */
		zft_unit    = tape_unit;
		access_mode = file_access_mode;
		zft_init_driver(); /* reset all static data to defaults */
	} else {
		tape_unit        = dev_minor;
		file_access_mode = access_mode;
		if ((result = ftape_enable(FTAPE_SEL(dev_minor))) < 0) {
			TRACE_ABORT(-ENXIO, ft_t_err,
				    "ftape_enable failed: %d", result);
		}
		if (ft_new_tape || ft_no_tape || !ft_formatted ||
		    (FTAPE_SEL(zft_unit) != FTAPE_SEL(dev_minor)) ||
		    (zft_unit & ZFT_RAW_MODE) != (dev_minor & ZFT_RAW_MODE)) {
			/* reset all static data to defaults,
			 */
			zft_init_driver(); 
		}
		zft_unit = dev_minor;
	}
	zft_set_flags(zft_unit); /* decode the minor bits */
	if (zft_blk_sz == 1 && zft_use_compression) {
		ftape_disable(); /* resets ft_no_tape */
		TRACE_ABORT(-ENODEV, ft_t_warn, "Variable block size not yet "
			    "supported with compression");
	}
	/*  no need for most of the buffers when no tape or not
	 *  formatted.  for the read/write operations, it is the
	 *  regardless whether there is no tape, a not-formatted tape
	 *  or the whether the driver is soft offline.  
	 *  Nevertheless we allow some ioctls with non-formatted tapes, 
	 *  like rewind and reset.
	 */
	if (ft_no_tape || !ft_formatted) {
		zft_uninit_mem();
	}
	if (ft_no_tape) {
		zft_offline = 1; /* so we need not test two variables */
	}
	if ((access_mode == O_WRONLY || access_mode == O_RDWR) &&
	    (ft_write_protected || ft_no_tape)) {
		ftape_disable(); /* resets ft_no_tape */
		TRACE_ABORT(ft_no_tape ? -ENXIO : -EROFS,
			    ft_t_warn, "wrong access mode %s cartridge",
			    ft_no_tape ? "without a" : "with write protected");
	}
	zft_write_protected = (access_mode == O_RDONLY || 
			       ft_write_protected != 0);
	if (zft_write_protected) {
		TRACE(ft_t_noise,
		      "read only access mode: %d, "
		      "drive write protected: %d", 
		      access_mode == O_RDONLY,
		      ft_write_protected != 0);
	}
	if (!zft_offline) {
		TRACE_CATCH(zft_vmalloc_once(&zft_deblock_buf,FT_SEGMENT_SIZE),
			    ftape_disable());
	}
	/* zft_seg_pos should be greater than the vtbl segpos but not
	 * if in compatibility mode and only after we read in the
	 * header segments
	 *
	 * might also be a problem if the user makes a backup with a
	 * *qft* device and rewinds it with a raw device.
	 */
	if (zft_qic_mode         &&
	    !zft_old_ftape       &&
	    zft_pos.seg_pos >= 0 &&
	    zft_header_read      && 
	    zft_pos.seg_pos <= ft_first_data_segment) {
		TRACE(ft_t_noise, "you probably mixed up the zftape devices!");
		zft_reset_position(&zft_pos); 
	}
	TRACE_EXIT 0;
}

/*      RELEASE routine called by kernel-interface code
 */
int _zft_close(void)
{
	int result = 0;
	TRACE_FUN(ft_t_flow);
	
	if (zft_offline) {
		/* call the hardware release routine. Puts the drive offline */
		ftape_disable();
		TRACE_EXIT 0;
	}
	if (!(ft_write_protected || zft_old_ftape)) {
		result = zft_flush_buffers();
		TRACE(ft_t_noise, "writing file mark at current position");
		if (zft_qic_mode && zft_close_volume(&zft_pos) == 0) {
			zft_move_past_eof(&zft_pos);
		}
		if ((zft_tape_at_lbot(&zft_pos) ||
		     !(zft_unit & FTAPE_NO_REWIND))) {
			if (result >= 0) {
				result = zft_update_header_segments();
			} else {
				TRACE(ft_t_err,
				"Error: unable to update header segments");
			}
		}
	}
	ftape_abort_operation();
	if (!(zft_unit & FTAPE_NO_REWIND)) {
		TRACE(ft_t_noise, "rewinding tape");
		if (ftape_seek_to_bot() < 0 && result >= 0) {
			result = -EIO; /* keep old value */
		}
		zft_reset_position(&zft_pos);
	} 
	zft_zap_read_buffers();
	/*  now free up memory as much as possible. We don't destroy
	 *  the deblock buffer if it containes a valid segment.
	 */
	if (zft_deblock_segment == -1) {
		zft_vfree(&zft_deblock_buf, FT_SEGMENT_SIZE); 
	}
	/* high level driver status, forces creation of a new volume
	 * when calling ftape_write again and not zft_just_before_eof
	 */
	zft_io_state = zft_idle;  
	if (going_offline) {
		zft_init_driver();
		zft_uninit_mem();
		going_offline = 0;
		zft_offline   = 1;
	} else if (zft_cmpr_lock(0 /* don't load */) == 0) {
		(*zft_cmpr_ops->reset)(); /* unlock it again */
	}
	zft_memory_stats();
	/* call the hardware release routine. Puts the drive offline */
	ftape_disable();
	TRACE_EXIT result;
}

/*
 *  the wrapper function around the wrapper MTIOCTOP ioctl
 */
static int mtioctop(struct mtop *mtop, int arg_size)
{
	int result = 0;
	fun_entry *mt_fun_entry;
	TRACE_FUN(ft_t_flow);
	
	if (arg_size != sizeof(struct mtop) || mtop->mt_op >= NR_MT_CMDS) {
		TRACE_EXIT -EINVAL;
	}
	TRACE(ft_t_noise, "calling MTIOCTOP command: %s",
	      mt_funs[mtop->mt_op].name);
	mt_fun_entry= &mt_funs[mtop->mt_op];
	zft_resid = mtop->mt_count;
	if (!mt_fun_entry->offline && zft_offline) {
		if (ft_no_tape) {
			TRACE_ABORT(-ENXIO, ft_t_info, "no tape present");
		} else {
			TRACE_ABORT(-ENXIO, ft_t_info, "drive is offline");
		}
	}
	if (!mt_fun_entry->not_formatted && !ft_formatted) {
		TRACE_ABORT(-EACCES, ft_t_info, "tape is not formatted");
	}
	if (!mt_fun_entry->write_protected) {
		TRACE_CATCH(zft_check_write_access(&zft_pos),);
	}
	if (mt_fun_entry->need_idle_state && !(zft_offline || !ft_formatted)) {
		TRACE_CATCH(zft_def_idle_state(),);
	}
	if (!zft_qic_mode && !mt_fun_entry->raw_mode) {
		TRACE_ABORT(-EACCES, ft_t_info, 
"Drive needs to be in QIC-80 compatibility mode for this command");
	}
	result = (mt_fun_entry->function)(&mtop->mt_count);
	if (zft_tape_at_lbot(&zft_pos)) {
		TRACE_CATCH(zft_update_header_segments(),);
	}
	if (result >= 0) {
		zft_resid = 0;
	}
	TRACE_EXIT result;
}

/*
 *  standard MTIOCGET ioctl
 */
static int mtiocget(struct mtget *mtget, int arg_size)
{
	const zft_volinfo *volume;
	__s64 max_tape_pos;
	TRACE_FUN(ft_t_flow);
	
	if (arg_size != sizeof(struct mtget)) {
		TRACE_ABORT(-EINVAL, ft_t_info, "bad argument size: %d",
			    arg_size);
	}
	mtget->mt_type  = ft_drive_type.vendor_id + 0x800000;
	mtget->mt_dsreg = ft_last_status.space;
	mtget->mt_erreg = ft_last_error.space; /* error register */
	mtget->mt_resid = zft_resid; /* residuum of writes, reads and
				      * MTIOCTOP commands 
				      */
	if (!zft_offline) { /* neither no_tape nor soft offline */
		mtget->mt_gstat = GMT_ONLINE(~0UL);
		/* should rather return the status of the cartridge
		 * than the access mode of the file, therefor use
		 * ft_write_protected, not zft_write_protected 
		 */
		if (ft_write_protected) {
			mtget->mt_gstat |= GMT_WR_PROT(~0UL);
		}
		if(zft_header_read) { /* this catches non-formatted */
			volume = zft_find_volume(zft_pos.seg_pos);
			mtget->mt_fileno = volume->count;
			max_tape_pos = zft_capacity - zft_blk_sz;
			if (zft_use_compression) {
				max_tape_pos -= ZFT_CMPR_OVERHEAD;
			}
			if (zft_tape_at_eod(&zft_pos)) {
				mtget->mt_gstat |= GMT_EOD(~0UL);
			}
			if (zft_pos.tape_pos > max_tape_pos) {
				mtget->mt_gstat |= GMT_EOT(~0UL);
			}
			mtget->mt_blkno = zft_div_blksz(zft_pos.volume_pos,
							volume->blk_sz);
			if (zft_just_before_eof) {
				mtget->mt_gstat |= GMT_EOF(~0UL);
			}
			if (zft_tape_at_lbot(&zft_pos)) {
				mtget->mt_gstat |= GMT_BOT(~0UL);
			}
		} else {
			mtget->mt_fileno = mtget->mt_blkno = -1;
			if (mtget->mt_dsreg & QIC_STATUS_AT_BOT) {
				mtget->mt_gstat |= GMT_BOT(~0UL);
			}
		}
	} else {
		if (ft_no_tape) {
			mtget->mt_gstat = GMT_DR_OPEN(~0UL);
		} else {
			mtget->mt_gstat = 0UL;
		}
 		mtget->mt_fileno = mtget->mt_blkno = -1;
	}
	TRACE_EXIT 0;
}

#ifdef MTIOCRDFTSEG
/*
 *  Read a floppy tape segment. This is useful for manipulating the
 *  volume table, and read the old header segment before re-formatting
 *  the cartridge.
 */
static int mtiocrdftseg(struct mtftseg * mtftseg, int arg_size)
{
	TRACE_FUN(ft_t_flow);
	
	TRACE(ft_t_noise, "Mag tape ioctl command: MTIOCRDFTSEG");
	if (zft_qic_mode) {
		TRACE_ABORT(-EACCES, ft_t_info,
			    "driver needs to be in raw mode for this ioctl");
	} 
	if (arg_size != sizeof(struct mtftseg)) {
		TRACE_ABORT(-EINVAL, ft_t_info, "bad argument size: %d",
			    arg_size);
	}
	if (zft_offline) {
		TRACE_EXIT -ENXIO;
	}
	if (mtftseg->mt_mode != FT_RD_SINGLE &&
	    mtftseg->mt_mode != FT_RD_AHEAD) {
		TRACE_ABORT(-EINVAL, ft_t_info, "invalid read mode");
	}
	if (!ft_formatted) {
		TRACE_EXIT -EACCES; /* -ENXIO ? */

	}
	if (!zft_header_read) {
		TRACE_CATCH(zft_def_idle_state(),);
	}
	if (mtftseg->mt_segno > ft_last_data_segment) {
		TRACE_ABORT(-EINVAL, ft_t_info, "segment number is too large");
	}
	mtftseg->mt_result = ftape_read_segment(mtftseg->mt_segno,
						zft_deblock_buf,