--- /dev/null
+/*
+ * 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>
+ */
+
+#define KMSG_COMPONENT "tape"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/proc_fs.h>
+#include <linux/mtio.h>
+#include <linux/compat.h>
+
+#include <asm/uaccess.h>
+
+#define TAPE_DBF_AREA tape_core_dbf
+
+#include "tape.h"
+#include "tape_std.h"
+#include "tape_class.h"
+
+#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 long tapechar_ioctl(struct file *, unsigned int, unsigned long);
+#ifdef CONFIG_COMPAT
+static long tapechar_compat_ioctl(struct file *, unsigned int, unsigned long);
+#endif
+
+static const struct file_operations tape_fops =
+{
+ .owner = THIS_MODULE,
+ .read = tapechar_read,
+ .write = tapechar_write,
+ .unlocked_ioctl = tapechar_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = tapechar_compat_ioctl,
+#endif
+ .open = tapechar_open,
+ .release = tapechar_release,
+ .llseek = no_llseek,
+};
+
+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);
+ 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 immediately.
+ */
+ 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;
+
+ 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);
+ /* 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;
+
+ 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);
+ 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(file_inode(filp)),
+ iminor(file_inode(filp)));
+
+ if (imajor(file_inode(filp)) != tapechar_major)
+ return -ENODEV;
+
+ minor = iminor(file_inode(filp));
+ device = tape_find_device(minor / TAPE_MINORS_PER_DEV);
+ if (IS_ERR(device)) {
+ DBF_EVENT(3, "TCHAR:open: tape_find_device() failed\n");
+ return PTR_ERR(device);
+ }
+
+ rc = tape_open(device);
+ if (rc == 0) {
+ filp->private_data = device;
+ nonseekable_open(inode, filp);
+ } else
+ tape_put_device(device);
+
+ 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 = NULL;
+ tape_put_device(device);
+
+ return 0;
+}
+
+/*
+ * Tape device io controls.
+ */
+static int
+__tapechar_ioctl(struct tape_device *device,
+ unsigned int no, unsigned long data)
+{
+ int rc;
+
+ 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:
+ 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->char_data.block_size << MT_ST_BLKSIZE_SHIFT)
+ & MT_ST_BLKSIZE_MASK);
+ /* 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_ioctl(struct file *filp, unsigned int no, unsigned long data)
+{
+ struct tape_device *device;
+ long rc;
+
+ DBF_EVENT(6, "TCHAR:ioct\n");
+
+ device = (struct tape_device *) filp->private_data;
+ mutex_lock(&device->mutex);
+ rc = __tapechar_ioctl(device, no, data);
+ mutex_unlock(&device->mutex);
+ return rc;
+}
+
+#ifdef CONFIG_COMPAT
+static long
+tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data)
+{
+ struct tape_device *device = filp->private_data;
+ int rval = -ENOIOCTLCMD;
+ unsigned long argp;
+
+ /* The 'arg' argument of any ioctl function may only be used for
+ * pointers because of the compat pointer conversion.
+ * Consider this when adding new ioctls.
+ */
+ argp = (unsigned long) compat_ptr(data);
+ if (device->discipline->ioctl_fn) {
+ mutex_lock(&device->mutex);
+ rval = device->discipline->ioctl_fn(device, no, argp);
+ mutex_unlock(&device->mutex);
+ if (rval == -EINVAL)
+ rval = -ENOIOCTLCMD;
+ }
+
+ return rval;
+}
+#endif /* CONFIG_COMPAT */
+
+/*
+ * 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);
+
+ return 0;
+}
+
+/*
+ * cleanup
+ */
+void
+tapechar_exit(void)
+{
+ unregister_chrdev_region(MKDEV(tapechar_major, 0), 256);
+}
Code Review / kvmfornfv.git / blobdiff