[deliverable/linux.git] / drivers / s390 / char / tape_char.c

/*
 *  drivers/s390/char/tape_char.c
 *    character device frontend for tape device driver
 *
 *  S390 and zSeries version
 *    Copyright IBM Corp. 2001,2006
 *    Author(s): Carsten Otte <cotte@de.ibm.com>
 *		 Michael Holzheu <holzheu@de.ibm.com>
 *		 Tuan Ngo-Anh <ngoanh@de.ibm.com>
 *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/proc_fs.h>
#include <linux/mtio.h>
#include <linux/smp_lock.h>

#include <asm/uaccess.h>

#define TAPE_DBF_AREA	tape_core_dbf

#include "tape.h"
#include "tape_std.h"
#include "tape_class.h"

#define PRINTK_HEADER "TAPE_CHAR: "

#define TAPECHAR_MAJOR		0	/* get dynamic major */

/*
 * file operation structure for tape character frontend
 */
static ssize_t tapechar_read(struct file *, char __user *, size_t, loff_t *);
static ssize_t tapechar_write(struct file *, const char __user *, size_t, loff_t *);
static int tapechar_open(struct inode *,struct file *);
static int tapechar_release(struct inode *,struct file *);
static int tapechar_ioctl(struct inode *, struct file *, unsigned int,
			  unsigned long);
static long tapechar_compat_ioctl(struct file *, unsigned int,
			  unsigned long);

static const struct file_operations tape_fops =
{
	.owner = THIS_MODULE,
	.read = tapechar_read,
	.write = tapechar_write,
	.ioctl = tapechar_ioctl,
	.compat_ioctl = tapechar_compat_ioctl,
	.open = tapechar_open,
	.release = tapechar_release,
};

static int tapechar_major = TAPECHAR_MAJOR;

/*
 * This function is called for every new tapedevice
 */
int
tapechar_setup_device(struct tape_device * device)
{
	char	device_name[20];

	sprintf(device_name, "ntibm%i", device->first_minor / 2);
	device->nt = register_tape_dev(
		&device->cdev->dev,
		MKDEV(tapechar_major, device->first_minor),
		&tape_fops,
		device_name,
		"non-rewinding"
	);
	device_name[0] = 'r';
	device->rt = register_tape_dev(
		&device->cdev->dev,
		MKDEV(tapechar_major, device->first_minor + 1),
		&tape_fops,
		device_name,
		"rewinding"
	);

	return 0;
}

void
tapechar_cleanup_device(struct tape_device *device)
{
	unregister_tape_dev(&device->cdev->dev, device->rt);
	device->rt = NULL;
	unregister_tape_dev(&device->cdev->dev, device->nt);
	device->nt = NULL;
}

static int
tapechar_check_idalbuffer(struct tape_device *device, size_t block_size)
{
	struct idal_buffer *new;

	if (device->char_data.idal_buf != NULL &&
	    device->char_data.idal_buf->size == block_size)
		return 0;

	if (block_size > MAX_BLOCKSIZE) {
		DBF_EVENT(3, "Invalid blocksize (%zd > %d)\n",
			block_size, MAX_BLOCKSIZE);
		PRINT_ERR("Invalid blocksize (%zd> %d)\n",
			block_size, MAX_BLOCKSIZE);
		return -EINVAL;
	}

	/* The current idal buffer is not correct. Allocate a new one. */
	new = idal_buffer_alloc(block_size, 0);
	if (IS_ERR(new))
		return -ENOMEM;

	if (device->char_data.idal_buf != NULL)
		idal_buffer_free(device->char_data.idal_buf);

	device->char_data.idal_buf = new;

	return 0;
}

/*
 * Tape device read function
 */
static ssize_t
tapechar_read(struct file *filp, char __user *data, size_t count, loff_t *ppos)
{
	struct tape_device *device;
	struct tape_request *request;
	size_t block_size;
	int rc;

	DBF_EVENT(6, "TCHAR:read\n");
	device = (struct tape_device *) filp->private_data;

	/*
	 * If the tape isn't terminated yet, do it now. And since we then
	 * are at the end of the tape there wouldn't be anything to read
	 * anyways. So we return immediatly.
	 */
	if(device->required_tapemarks) {
		return tape_std_terminate_write(device);
	}

	/* Find out block size to use */
	if (device->char_data.block_size != 0) {
		if (count < device->char_data.block_size) {
			DBF_EVENT(3, "TCHAR:read smaller than block "
				  "size was requested\n");
			return -EINVAL;
		}
		block_size = device->char_data.block_size;
	} else {
		block_size = count;
	}

	rc = tapechar_check_idalbuffer(device, block_size);
	if (rc)
		return rc;

#ifdef CONFIG_S390_TAPE_BLOCK
	/* Changes position. */
	device->blk_data.medium_changed = 1;
#endif

	DBF_EVENT(6, "TCHAR:nbytes: %lx\n", block_size);
	/* Let the discipline build the ccw chain. */
	request = device->discipline->read_block(device, block_size);
	if (IS_ERR(request))
		return PTR_ERR(request);
	/* Execute it. */
	rc = tape_do_io(device, request);
	if (rc == 0) {
		rc = block_size - request->rescnt;
		DBF_EVENT(6, "TCHAR:rbytes:  %x\n", rc);
		filp->f_pos += rc;
		/* Copy data from idal buffer to user space. */
		if (idal_buffer_to_user(device->char_data.idal_buf,
					data, rc) != 0)
			rc = -EFAULT;
	}
	tape_free_request(request);
	return rc;
}

/*
 * Tape device write function
 */
static ssize_t
tapechar_write(struct file *filp, const char __user *data, size_t count, loff_t *ppos)
{
	struct tape_device *device;
	struct tape_request *request;
	size_t block_size;
	size_t written;
	int nblocks;
	int i, rc;

	DBF_EVENT(6, "TCHAR:write\n");
	device = (struct tape_device *) filp->private_data;
	/* Find out block size and number of blocks */
	if (device->char_data.block_size != 0) {
		if (count < device->char_data.block_size) {
			DBF_EVENT(3, "TCHAR:write smaller than block "
				  "size was requested\n");
			return -EINVAL;
		}
		block_size = device->char_data.block_size;
		nblocks = count / block_size;
	} else {
		block_size = count;
		nblocks = 1;
	}

	rc = tapechar_check_idalbuffer(device, block_size);
	if (rc)
		return rc;

#ifdef CONFIG_S390_TAPE_BLOCK
	/* Changes position. */
	device->blk_data.medium_changed = 1;
#endif

	DBF_EVENT(6,"TCHAR:nbytes: %lx\n", block_size);
	DBF_EVENT(6, "TCHAR:nblocks: %x\n", nblocks);
	/* Let the discipline build the ccw chain. */
	request = device->discipline->write_block(device, block_size);
	if (IS_ERR(request))
		return PTR_ERR(request);
	rc = 0;
	written = 0;
	for (i = 0; i < nblocks; i++) {
		/* Copy data from user space to idal buffer. */
		if (idal_buffer_from_user(device->char_data.idal_buf,
					  data, block_size)) {
			rc = -EFAULT;
			break;
		}
		rc = tape_do_io(device, request);
		if (rc)
			break;
		DBF_EVENT(6, "TCHAR:wbytes: %lx\n",
			  block_size - request->rescnt);
		filp->f_pos += block_size - request->rescnt;
		written += block_size - request->rescnt;
		if (request->rescnt != 0)
			break;
		data += block_size;
	}
	tape_free_request(request);
	if (rc == -ENOSPC) {
		/*
		 * Ok, the device has no more space. It has NOT written
		 * the block.
		 */
		if (device->discipline->process_eov)
			device->discipline->process_eov(device);
		if (written > 0)
			rc = 0;

	}

	/*
	 * After doing a write we always need two tapemarks to correctly
	 * terminate the tape (one to terminate the file, the second to
	 * flag the end of recorded data.
	 * Since process_eov positions the tape in front of the written
	 * tapemark it doesn't hurt to write two marks again.
	 */
	if (!rc)
		device->required_tapemarks = 2;

	return rc ? rc : written;
}

/*
 * Character frontend tape device open function.
 */
static int
tapechar_open (struct inode *inode, struct file *filp)
{
	struct tape_device *device;
	int minor, rc;

	DBF_EVENT(6, "TCHAR:open: %i:%i\n",
		imajor(filp->f_path.dentry->d_inode),
		iminor(filp->f_path.dentry->d_inode));

	if (imajor(filp->f_path.dentry->d_inode) != tapechar_major)
		return -ENODEV;

	lock_kernel();
	minor = iminor(filp->f_path.dentry->d_inode);
	device = tape_get_device(minor / TAPE_MINORS_PER_DEV);
	if (IS_ERR(device)) {
		DBF_EVENT(3, "TCHAR:open: tape_get_device() failed\n");
		rc = PTR_ERR(device);
		goto out;
	}


	rc = tape_open(device);
	if (rc == 0) {
		filp->private_data = device;
		rc = nonseekable_open(inode, filp);
	}
	else
		tape_put_device(device);

out:
	unlock_kernel();
	return rc;
}

/*
 * Character frontend tape device release function.
 */

static int
tapechar_release(struct inode *inode, struct file *filp)
{
	struct tape_device *device;

	DBF_EVENT(6, "TCHAR:release: %x\n", iminor(inode));
	device = (struct tape_device *) filp->private_data;

	/*
	 * If this is the rewinding tape minor then rewind. In that case we
	 * write all required tapemarks. Otherwise only one to terminate the
	 * file.
	 */
	if ((iminor(inode) & 1) != 0) {
		if (device->required_tapemarks)
			tape_std_terminate_write(device);
		tape_mtop(device, MTREW, 1);
	} else {
		if (device->required_tapemarks > 1) {
			if (tape_mtop(device, MTWEOF, 1) == 0)
				device->required_tapemarks--;
		}
	}

	if (device->char_data.idal_buf != NULL) {
		idal_buffer_free(device->char_data.idal_buf);
		device->char_data.idal_buf = NULL;
	}
	tape_release(device);
	filp->private_data = tape_put_device(device);

	return 0;
}

/*
 * Tape device io controls.
 */
static int
tapechar_ioctl(struct inode *inp, struct file *filp,
	       unsigned int no, unsigned long data)
{
	struct tape_device *device;
	int rc;

	DBF_EVENT(6, "TCHAR:ioct\n");

	device = (struct tape_device *) filp->private_data;

	if (no == MTIOCTOP) {
		struct mtop op;

		if (copy_from_user(&op, (char __user *) data, sizeof(op)) != 0)
			return -EFAULT;
		if (op.mt_count < 0)
			return -EINVAL;

		/*
		 * Operations that change tape position should write final
		 * tapemarks.
		 */
		switch (op.mt_op) {
			case MTFSF:
			case MTBSF:
			case MTFSR:
			case MTBSR:
			case MTREW:
			case MTOFFL:
			case MTEOM:
			case MTRETEN:
			case MTBSFM:
			case MTFSFM:
			case MTSEEK:
#ifdef CONFIG_S390_TAPE_BLOCK
				device->blk_data.medium_changed = 1;
#endif
				if (device->required_tapemarks)
					tape_std_terminate_write(device);
			default:
				;
		}
		rc = tape_mtop(device, op.mt_op, op.mt_count);

		if (op.mt_op == MTWEOF && rc == 0) {
			if (op.mt_count > device->required_tapemarks)
				device->required_tapemarks = 0;
			else
				device->required_tapemarks -= op.mt_count;
		}
		return rc;
	}
	if (no == MTIOCPOS) {
		/* MTIOCPOS: query the tape position. */
		struct mtpos pos;

		rc = tape_mtop(device, MTTELL, 1);
		if (rc < 0)
			return rc;
		pos.mt_blkno = rc;
		if (copy_to_user((char __user *) data, &pos, sizeof(pos)) != 0)
			return -EFAULT;
		return 0;
	}
	if (no == MTIOCGET) {
		/* MTIOCGET: query the tape drive status. */
		struct mtget get;

		memset(&get, 0, sizeof(get));
		get.mt_type = MT_ISUNKNOWN;
		get.mt_resid = 0 /* device->devstat.rescnt */;
		get.mt_dsreg = device->tape_state;
		/* FIXME: mt_gstat, mt_erreg, mt_fileno */
		get.mt_gstat = 0;
		get.mt_erreg = 0;
		get.mt_fileno = 0;
		get.mt_gstat  = device->tape_generic_status;

		if (device->medium_state == MS_LOADED) {
			rc = tape_mtop(device, MTTELL, 1);

			if (rc < 0)
				return rc;

			if (rc == 0)
				get.mt_gstat |= GMT_BOT(~0);

			get.mt_blkno = rc;
		}

		if (copy_to_user((char __user *) data, &get, sizeof(get)) != 0)
			return -EFAULT;

		return 0;
	}
	/* Try the discipline ioctl function. */
	if (device->discipline->ioctl_fn == NULL)
		return -EINVAL;
	return device->discipline->ioctl_fn(device, no, data);
}

static long
tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data)
{
	struct tape_device *device = filp->private_data;
	int rval = -ENOIOCTLCMD;

	if (device->discipline->ioctl_fn) {
		lock_kernel();
		rval = device->discipline->ioctl_fn(device, no, data);
		unlock_kernel();
		if (rval == -EINVAL)
			rval = -ENOIOCTLCMD;
	}

	return rval;
}

/*
 * Initialize character device frontend.
 */
int
tapechar_init (void)
{
	dev_t	dev;

	if (alloc_chrdev_region(&dev, 0, 256, "tape") != 0)
		return -1;

	tapechar_major = MAJOR(dev);
	PRINT_INFO("tape gets major %d for character devices\n", MAJOR(dev));

	return 0;
}

/*
 * cleanup
 */
void
tapechar_exit(void)
{
	PRINT_INFO("tape releases major %d for character devices\n",
		tapechar_major);
	unregister_chrdev_region(MKDEV(tapechar_major, 0), 256);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* drivers/s390/char/tape_char.c
	3	* character device frontend for tape device driver
	4	*
	5	* S390 and zSeries version
cced1dd4	6	* Copyright IBM Corp. 2001,2006
1da177e4 LT	7	* Author(s): Carsten Otte <cotte@de.ibm.com>
	8	* Michael Holzheu <holzheu@de.ibm.com>
	9	* Tuan Ngo-Anh <ngoanh@de.ibm.com>
	10	* Martin Schwidefsky <schwidefsky@de.ibm.com>
	11	*/
	12
1da177e4 LT	13	#include <linux/module.h>
	14	#include <linux/types.h>
	15	#include <linux/proc_fs.h>
	16	#include <linux/mtio.h>
764a4a8e	17	#include <linux/smp_lock.h>
1da177e4 LT	18
	19	#include <asm/uaccess.h>
	20
	21	#define TAPE_DBF_AREA tape_core_dbf
	22
	23	#include "tape.h"
	24	#include "tape_std.h"
	25	#include "tape_class.h"
	26
	27	#define PRINTK_HEADER "TAPE_CHAR: "
	28
	29	#define TAPECHAR_MAJOR 0 /* get dynamic major */
	30
	31	/*
	32	* file operation structure for tape character frontend
	33	*/
	34	static ssize_t tapechar_read(struct file , char __user , size_t, loff_t *);
	35	static ssize_t tapechar_write(struct file , const char __user , size_t, loff_t *);
	36	static int tapechar_open(struct inode ,struct file );
	37	static int tapechar_release(struct inode ,struct file );
	38	static int tapechar_ioctl(struct inode , struct file , unsigned int,
	39	unsigned long);
f042e0f8 CH	40	static long tapechar_compat_ioctl(struct file *, unsigned int,
f042e0f8 CH	41	unsigned long);
1da177e4	42
d54b1fdb	43	static const struct file_operations tape_fops =
1da177e4 LT	44	{
	45	.owner = THIS_MODULE,
	46	.read = tapechar_read,
	47	.write = tapechar_write,
	48	.ioctl = tapechar_ioctl,
f042e0f8	49	.compat_ioctl = tapechar_compat_ioctl,
1da177e4 LT	50	.open = tapechar_open,
	51	.release = tapechar_release,
	52	};
	53
	54	static int tapechar_major = TAPECHAR_MAJOR;
	55
	56	/*
	57	* This function is called for every new tapedevice
	58	*/
	59	int
	60	tapechar_setup_device(struct tape_device * device)
	61	{
	62	char device_name[20];
	63
	64	sprintf(device_name, "ntibm%i", device->first_minor / 2);
	65	device->nt = register_tape_dev(
	66	&device->cdev->dev,
	67	MKDEV(tapechar_major, device->first_minor),
	68	&tape_fops,
	69	device_name,
	70	"non-rewinding"
	71	);
	72	device_name[0] = 'r';
	73	device->rt = register_tape_dev(
	74	&device->cdev->dev,
	75	MKDEV(tapechar_major, device->first_minor + 1),
	76	&tape_fops,
	77	device_name,
	78	"rewinding"
	79	);
	80
	81	return 0;
	82	}
	83
	84	void
	85	tapechar_cleanup_device(struct tape_device *device)
	86	{
92bf435f	87	unregister_tape_dev(&device->cdev->dev, device->rt);
1da177e4	88	device->rt = NULL;
92bf435f	89	unregister_tape_dev(&device->cdev->dev, device->nt);
1da177e4 LT	90	device->nt = NULL;
	91	}
	92
4d284cac	93	static int
1da177e4 LT	94	tapechar_check_idalbuffer(struct tape_device *device, size_t block_size)
	95	{
	96	struct idal_buffer *new;
	97
	98	if (device->char_data.idal_buf != NULL &&
	99	device->char_data.idal_buf->size == block_size)
	100	return 0;
	101
	102	if (block_size > MAX_BLOCKSIZE) {
	103	DBF_EVENT(3, "Invalid blocksize (%zd > %d)\n",
	104	block_size, MAX_BLOCKSIZE);
	105	PRINT_ERR("Invalid blocksize (%zd> %d)\n",
	106	block_size, MAX_BLOCKSIZE);
	107	return -EINVAL;
	108	}
	109
	110	/* The current idal buffer is not correct. Allocate a new one. */
	111	new = idal_buffer_alloc(block_size, 0);
0983e568	112	if (IS_ERR(new))
1da177e4 LT	113	return -ENOMEM;
	114
	115	if (device->char_data.idal_buf != NULL)
	116	idal_buffer_free(device->char_data.idal_buf);
	117
	118	device->char_data.idal_buf = new;
	119
	120	return 0;
	121	}
	122
	123	/*
	124	* Tape device read function
	125	*/
2b67fc46	126	static ssize_t
1da177e4 LT	127	tapechar_read(struct file filp, char __user data, size_t count, loff_t *ppos)
	128	{
	129	struct tape_device *device;
	130	struct tape_request *request;
	131	size_t block_size;
	132	int rc;
	133
	134	DBF_EVENT(6, "TCHAR:read\n");
	135	device = (struct tape_device *) filp->private_data;
	136
	137	/*
	138	* If the tape isn't terminated yet, do it now. And since we then
	139	* are at the end of the tape there wouldn't be anything to read
	140	* anyways. So we return immediatly.
	141	*/
	142	if(device->required_tapemarks) {
	143	return tape_std_terminate_write(device);
	144	}
	145
	146	/* Find out block size to use */
	147	if (device->char_data.block_size != 0) {
	148	if (count < device->char_data.block_size) {
	149	DBF_EVENT(3, "TCHAR:read smaller than block "
	150	"size was requested\n");
	151	return -EINVAL;
	152	}
	153	block_size = device->char_data.block_size;
	154	} else {
	155	block_size = count;
	156	}
	157
	158	rc = tapechar_check_idalbuffer(device, block_size);
	159	if (rc)
	160	return rc;
	161
	162	#ifdef CONFIG_S390_TAPE_BLOCK
	163	/* Changes position. */
	164	device->blk_data.medium_changed = 1;
	165	#endif
	166
	167	DBF_EVENT(6, "TCHAR:nbytes: %lx\n", block_size);
	168	/* Let the discipline build the ccw chain. */
	169	request = device->discipline->read_block(device, block_size);
	170	if (IS_ERR(request))
	171	return PTR_ERR(request);
	172	/* Execute it. */
	173	rc = tape_do_io(device, request);
	174	if (rc == 0) {
	175	rc = block_size - request->rescnt;
	176	DBF_EVENT(6, "TCHAR:rbytes: %x\n", rc);
	177	filp->f_pos += rc;
	178	/* Copy data from idal buffer to user space. */
	179	if (idal_buffer_to_user(device->char_data.idal_buf,
	180	data, rc) != 0)
	181	rc = -EFAULT;
	182	}
	183	tape_free_request(request);
	184	return rc;
	185	}
	186
	187	/*
	188	* Tape device write function
	189	*/
2b67fc46	190	static ssize_t
1da177e4 LT	191	tapechar_write(struct file filp, const char __user data, size_t count, loff_t *ppos)
	192	{
	193	struct tape_device *device;
	194	struct tape_request *request;
	195	size_t block_size;
	196	size_t written;
	197	int nblocks;
	198	int i, rc;
	199
	200	DBF_EVENT(6, "TCHAR:write\n");
	201	device = (struct tape_device *) filp->private_data;
	202	/* Find out block size and number of blocks */
	203	if (device->char_data.block_size != 0) {
	204	if (count < device->char_data.block_size) {
	205	DBF_EVENT(3, "TCHAR:write smaller than block "
	206	"size was requested\n");
	207	return -EINVAL;
	208	}
	209	block_size = device->char_data.block_size;
	210	nblocks = count / block_size;
	211	} else {
	212	block_size = count;
	213	nblocks = 1;
	214	}
	215
	216	rc = tapechar_check_idalbuffer(device, block_size);
	217	if (rc)
	218	return rc;
	219
	220	#ifdef CONFIG_S390_TAPE_BLOCK
	221	/* Changes position. */
	222	device->blk_data.medium_changed = 1;
	223	#endif
	224
	225	DBF_EVENT(6,"TCHAR:nbytes: %lx\n", block_size);
	226	DBF_EVENT(6, "TCHAR:nblocks: %x\n", nblocks);
	227	/* Let the discipline build the ccw chain. */
	228	request = device->discipline->write_block(device, block_size);
	229	if (IS_ERR(request))
	230	return PTR_ERR(request);
	231	rc = 0;
	232	written = 0;
	233	for (i = 0; i < nblocks; i++) {
	234	/* Copy data from user space to idal buffer. */
	235	if (idal_buffer_from_user(device->char_data.idal_buf,
	236	data, block_size)) {
	237	rc = -EFAULT;
	238	break;
	239	}
	240	rc = tape_do_io(device, request);
	241	if (rc)
	242	break;
	243	DBF_EVENT(6, "TCHAR:wbytes: %lx\n",
	244	block_size - request->rescnt);
	245	filp->f_pos += block_size - request->rescnt;
	246	written += block_size - request->rescnt;
	247	if (request->rescnt != 0)
	248	break;
	249	data += block_size;
	250	}
	251	tape_free_request(request);
	252	if (rc == -ENOSPC) {
	253	/*
	254	* Ok, the device has no more space. It has NOT written
255	* the block.
256	*/
257	if (device->discipline->process_eov)
258	device->discipline->process_eov(device);
259	if (written > 0)
260	rc = 0;
261
262	}
263
264	/*
265	* After doing a write we always need two tapemarks to correctly
266	* terminate the tape (one to terminate the file, the second to
267	* flag the end of recorded data.
268	* Since process_eov positions the tape in front of the written
269	* tapemark it doesn't hurt to write two marks again.
270	*/
271	if (!rc)
272	device->required_tapemarks = 2;
273
274	return rc ? rc : written;
275	}
276
277	/*
278	* Character frontend tape device open function.
279	*/
2b67fc46	280	static int
1da177e4 LT	281	tapechar_open (struct inode inode, struct file filp)
	282	{
	283	struct tape_device *device;
	284	int minor, rc;
	285
	286	DBF_EVENT(6, "TCHAR:open: %i:%i\n",
49522c97 JS	287	imajor(filp->f_path.dentry->d_inode),
49522c97 JS	288	iminor(filp->f_path.dentry->d_inode));
1da177e4	289
49522c97	290	if (imajor(filp->f_path.dentry->d_inode) != tapechar_major)
1da177e4 LT	291	return -ENODEV;
1da177e4 LT	292
764a4a8e	293	lock_kernel();
49522c97	294	minor = iminor(filp->f_path.dentry->d_inode);
1da177e4 LT	295	device = tape_get_device(minor / TAPE_MINORS_PER_DEV);
	296	if (IS_ERR(device)) {
	297	DBF_EVENT(3, "TCHAR:open: tape_get_device() failed\n");
764a4a8e JC	298	rc = PTR_ERR(device);
764a4a8e JC	299	goto out;
1da177e4 LT	300	}
	301
	302
	303	rc = tape_open(device);
	304	if (rc == 0) {
	305	filp->private_data = device;
764a4a8e	306	rc = nonseekable_open(inode, filp);
1da177e4	307	}
764a4a8e JC	308	else
764a4a8e JC	309	tape_put_device(device);
1da177e4	310
764a4a8e JC	311	out:
764a4a8e JC	312	unlock_kernel();
1da177e4 LT	313	return rc;
	314	}
	315
	316	/*
	317	* Character frontend tape device release function.
	318	*/
	319
2b67fc46	320	static int
1da177e4 LT	321	tapechar_release(struct inode inode, struct file filp)
	322	{
	323	struct tape_device *device;
	324
	325	DBF_EVENT(6, "TCHAR:release: %x\n", iminor(inode));
	326	device = (struct tape_device *) filp->private_data;
	327
	328	/*
	329	* If this is the rewinding tape minor then rewind. In that case we
	330	* write all required tapemarks. Otherwise only one to terminate the
	331	* file.
	332	*/
	333	if ((iminor(inode) & 1) != 0) {
	334	if (device->required_tapemarks)
	335	tape_std_terminate_write(device);
	336	tape_mtop(device, MTREW, 1);
	337	} else {
	338	if (device->required_tapemarks > 1) {
	339	if (tape_mtop(device, MTWEOF, 1) == 0)
	340	device->required_tapemarks--;
	341	}
	342	}
	343
	344	if (device->char_data.idal_buf != NULL) {
	345	idal_buffer_free(device->char_data.idal_buf);
	346	device->char_data.idal_buf = NULL;
	347	}
	348	tape_release(device);
	349	filp->private_data = tape_put_device(device);
	350
	351	return 0;
	352	}
	353
	354	/*
	355	* Tape device io controls.
	356	*/
	357	static int
	358	tapechar_ioctl(struct inode inp, struct file filp,
	359	unsigned int no, unsigned long data)
	360	{
	361	struct tape_device *device;
	362	int rc;
	363
	364	DBF_EVENT(6, "TCHAR:ioct\n");
	365
	366	device = (struct tape_device *) filp->private_data;
	367
	368	if (no == MTIOCTOP) {
	369	struct mtop op;
	370
	371	if (copy_from_user(&op, (char __user *) data, sizeof(op)) != 0)
	372	return -EFAULT;
	373	if (op.mt_count < 0)
	374	return -EINVAL;
	375
	376	/*
	377	* Operations that change tape position should write final
	378	* tapemarks.
	379	*/
	380	switch (op.mt_op) {
	381	case MTFSF:
	382	case MTBSF:
	383	case MTFSR:
	384	case MTBSR:
385	case MTREW:
386	case MTOFFL:
387	case MTEOM:
388	case MTRETEN:
389	case MTBSFM:
390	case MTFSFM:
391	case MTSEEK:
392	#ifdef CONFIG_S390_TAPE_BLOCK
393	device->blk_data.medium_changed = 1;
394	#endif
395	if (device->required_tapemarks)
396	tape_std_terminate_write(device);
397	default:
398	;
399	}
400	rc = tape_mtop(device, op.mt_op, op.mt_count);
401
402	if (op.mt_op == MTWEOF && rc == 0) {
403	if (op.mt_count > device->required_tapemarks)
404	device->required_tapemarks = 0;
405	else
406	device->required_tapemarks -= op.mt_count;
407	}
408	return rc;
409	}
410	if (no == MTIOCPOS) {
411	/* MTIOCPOS: query the tape position. */
412	struct mtpos pos;
413
414	rc = tape_mtop(device, MTTELL, 1);
415	if (rc < 0)
416	return rc;
417	pos.mt_blkno = rc;
418	if (copy_to_user((char __user *) data, &pos, sizeof(pos)) != 0)
419	return -EFAULT;
420	return 0;
421	}
422	if (no == MTIOCGET) {
423	/* MTIOCGET: query the tape drive status. */
424	struct mtget get;
425
426	memset(&get, 0, sizeof(get));
427	get.mt_type = MT_ISUNKNOWN;
428	get.mt_resid = 0 /* device->devstat.rescnt */;
429	get.mt_dsreg = device->tape_state;
430	/* FIXME: mt_gstat, mt_erreg, mt_fileno */
431	get.mt_gstat = 0;
432	get.mt_erreg = 0;
433	get.mt_fileno = 0;
434	get.mt_gstat = device->tape_generic_status;
435
436	if (device->medium_state == MS_LOADED) {
437	rc = tape_mtop(device, MTTELL, 1);
438
439	if (rc < 0)
440	return rc;
441
442	if (rc == 0)
443	get.mt_gstat \|= GMT_BOT(~0);
444
445	get.mt_blkno = rc;
446	}
447
448	if (copy_to_user((char __user *) data, &get, sizeof(get)) != 0)
449	return -EFAULT;
450
451	return 0;
452	}
453	/* Try the discipline ioctl function. */
454	if (device->discipline->ioctl_fn == NULL)
455	return -EINVAL;
456	return device->discipline->ioctl_fn(device, no, data);
457	}
458
f042e0f8 CH	459	static long
	460	tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data)
	461	{
	462	struct tape_device *device = filp->private_data;
	463	int rval = -ENOIOCTLCMD;
	464
	465	if (device->discipline->ioctl_fn) {
	466	lock_kernel();
	467	rval = device->discipline->ioctl_fn(device, no, data);
	468	unlock_kernel();
	469	if (rval == -EINVAL)
	470	rval = -ENOIOCTLCMD;
	471	}
	472
	473	return rval;
	474	}
	475
1da177e4 LT	476	/*
	477	* Initialize character device frontend.
	478	*/
	479	int
	480	tapechar_init (void)
	481	{
	482	dev_t dev;
	483
	484	if (alloc_chrdev_region(&dev, 0, 256, "tape") != 0)
	485	return -1;
	486
	487	tapechar_major = MAJOR(dev);
	488	PRINT_INFO("tape gets major %d for character devices\n", MAJOR(dev));
	489
	490	return 0;
	491	}
	492
	493	/*
	494	* cleanup
	495	*/
	496	void
	497	tapechar_exit(void)
	498	{
	499	PRINT_INFO("tape releases major %d for character devices\n",
	500	tapechar_major);
	501	unregister_chrdev_region(MKDEV(tapechar_major, 0), 256);
	502	}