mirror of https://gitee.com/openkylin/linux.git
499 lines
11 KiB
C
499 lines
11 KiB
C
/*
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* character device frontend for tape device driver
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*
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* S390 and zSeries version
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* Copyright IBM Corp. 2001, 2006
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* Author(s): Carsten Otte <cotte@de.ibm.com>
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* Michael Holzheu <holzheu@de.ibm.com>
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* Tuan Ngo-Anh <ngoanh@de.ibm.com>
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* Martin Schwidefsky <schwidefsky@de.ibm.com>
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*/
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#define KMSG_COMPONENT "tape"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/proc_fs.h>
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#include <linux/mtio.h>
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#include <linux/compat.h>
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#include <asm/uaccess.h>
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#define TAPE_DBF_AREA tape_core_dbf
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#include "tape.h"
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#include "tape_std.h"
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#include "tape_class.h"
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#define TAPECHAR_MAJOR 0 /* get dynamic major */
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/*
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* file operation structure for tape character frontend
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*/
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static ssize_t tapechar_read(struct file *, char __user *, size_t, loff_t *);
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static ssize_t tapechar_write(struct file *, const char __user *, size_t, loff_t *);
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static int tapechar_open(struct inode *,struct file *);
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static int tapechar_release(struct inode *,struct file *);
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static long tapechar_ioctl(struct file *, unsigned int, unsigned long);
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#ifdef CONFIG_COMPAT
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static long tapechar_compat_ioctl(struct file *, unsigned int, unsigned long);
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#endif
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static const struct file_operations tape_fops =
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{
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.owner = THIS_MODULE,
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.read = tapechar_read,
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.write = tapechar_write,
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.unlocked_ioctl = tapechar_ioctl,
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#ifdef CONFIG_COMPAT
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.compat_ioctl = tapechar_compat_ioctl,
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#endif
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.open = tapechar_open,
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.release = tapechar_release,
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.llseek = no_llseek,
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};
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static int tapechar_major = TAPECHAR_MAJOR;
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/*
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* This function is called for every new tapedevice
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*/
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int
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tapechar_setup_device(struct tape_device * device)
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{
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char device_name[20];
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sprintf(device_name, "ntibm%i", device->first_minor / 2);
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device->nt = register_tape_dev(
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&device->cdev->dev,
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MKDEV(tapechar_major, device->first_minor),
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&tape_fops,
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device_name,
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"non-rewinding"
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);
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device_name[0] = 'r';
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device->rt = register_tape_dev(
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&device->cdev->dev,
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MKDEV(tapechar_major, device->first_minor + 1),
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&tape_fops,
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device_name,
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"rewinding"
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);
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return 0;
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}
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void
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tapechar_cleanup_device(struct tape_device *device)
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{
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unregister_tape_dev(&device->cdev->dev, device->rt);
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device->rt = NULL;
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unregister_tape_dev(&device->cdev->dev, device->nt);
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device->nt = NULL;
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}
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static int
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tapechar_check_idalbuffer(struct tape_device *device, size_t block_size)
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{
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struct idal_buffer *new;
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if (device->char_data.idal_buf != NULL &&
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device->char_data.idal_buf->size == block_size)
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return 0;
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if (block_size > MAX_BLOCKSIZE) {
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DBF_EVENT(3, "Invalid blocksize (%zd > %d)\n",
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block_size, MAX_BLOCKSIZE);
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return -EINVAL;
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}
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/* The current idal buffer is not correct. Allocate a new one. */
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new = idal_buffer_alloc(block_size, 0);
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if (IS_ERR(new))
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return -ENOMEM;
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if (device->char_data.idal_buf != NULL)
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idal_buffer_free(device->char_data.idal_buf);
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device->char_data.idal_buf = new;
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return 0;
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}
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/*
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* Tape device read function
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*/
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static ssize_t
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tapechar_read(struct file *filp, char __user *data, size_t count, loff_t *ppos)
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{
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struct tape_device *device;
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struct tape_request *request;
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size_t block_size;
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int rc;
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DBF_EVENT(6, "TCHAR:read\n");
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device = (struct tape_device *) filp->private_data;
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/*
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* If the tape isn't terminated yet, do it now. And since we then
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* are at the end of the tape there wouldn't be anything to read
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* anyways. So we return immediately.
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*/
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if(device->required_tapemarks) {
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return tape_std_terminate_write(device);
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}
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/* Find out block size to use */
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if (device->char_data.block_size != 0) {
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if (count < device->char_data.block_size) {
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DBF_EVENT(3, "TCHAR:read smaller than block "
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"size was requested\n");
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return -EINVAL;
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}
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block_size = device->char_data.block_size;
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} else {
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block_size = count;
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}
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rc = tapechar_check_idalbuffer(device, block_size);
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if (rc)
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return rc;
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DBF_EVENT(6, "TCHAR:nbytes: %lx\n", block_size);
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/* Let the discipline build the ccw chain. */
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request = device->discipline->read_block(device, block_size);
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if (IS_ERR(request))
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return PTR_ERR(request);
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/* Execute it. */
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rc = tape_do_io(device, request);
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if (rc == 0) {
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rc = block_size - request->rescnt;
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DBF_EVENT(6, "TCHAR:rbytes: %x\n", rc);
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/* Copy data from idal buffer to user space. */
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if (idal_buffer_to_user(device->char_data.idal_buf,
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data, rc) != 0)
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rc = -EFAULT;
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}
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tape_free_request(request);
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return rc;
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}
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/*
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* Tape device write function
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*/
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static ssize_t
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tapechar_write(struct file *filp, const char __user *data, size_t count, loff_t *ppos)
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{
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struct tape_device *device;
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struct tape_request *request;
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size_t block_size;
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size_t written;
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int nblocks;
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int i, rc;
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DBF_EVENT(6, "TCHAR:write\n");
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device = (struct tape_device *) filp->private_data;
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/* Find out block size and number of blocks */
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if (device->char_data.block_size != 0) {
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if (count < device->char_data.block_size) {
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DBF_EVENT(3, "TCHAR:write smaller than block "
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"size was requested\n");
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return -EINVAL;
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}
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block_size = device->char_data.block_size;
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nblocks = count / block_size;
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} else {
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block_size = count;
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nblocks = 1;
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}
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rc = tapechar_check_idalbuffer(device, block_size);
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if (rc)
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return rc;
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DBF_EVENT(6,"TCHAR:nbytes: %lx\n", block_size);
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DBF_EVENT(6, "TCHAR:nblocks: %x\n", nblocks);
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/* Let the discipline build the ccw chain. */
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request = device->discipline->write_block(device, block_size);
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if (IS_ERR(request))
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return PTR_ERR(request);
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rc = 0;
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written = 0;
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for (i = 0; i < nblocks; i++) {
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/* Copy data from user space to idal buffer. */
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if (idal_buffer_from_user(device->char_data.idal_buf,
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data, block_size)) {
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rc = -EFAULT;
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break;
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}
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rc = tape_do_io(device, request);
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if (rc)
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break;
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DBF_EVENT(6, "TCHAR:wbytes: %lx\n",
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block_size - request->rescnt);
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written += block_size - request->rescnt;
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if (request->rescnt != 0)
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break;
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data += block_size;
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}
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tape_free_request(request);
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if (rc == -ENOSPC) {
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/*
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* Ok, the device has no more space. It has NOT written
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* the block.
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*/
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if (device->discipline->process_eov)
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device->discipline->process_eov(device);
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if (written > 0)
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rc = 0;
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}
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/*
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* After doing a write we always need two tapemarks to correctly
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* terminate the tape (one to terminate the file, the second to
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* flag the end of recorded data.
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* Since process_eov positions the tape in front of the written
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* tapemark it doesn't hurt to write two marks again.
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*/
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if (!rc)
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device->required_tapemarks = 2;
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return rc ? rc : written;
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}
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/*
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* Character frontend tape device open function.
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*/
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static int
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tapechar_open (struct inode *inode, struct file *filp)
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{
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struct tape_device *device;
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int minor, rc;
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DBF_EVENT(6, "TCHAR:open: %i:%i\n",
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imajor(file_inode(filp)),
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iminor(file_inode(filp)));
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if (imajor(file_inode(filp)) != tapechar_major)
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return -ENODEV;
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minor = iminor(file_inode(filp));
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device = tape_find_device(minor / TAPE_MINORS_PER_DEV);
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if (IS_ERR(device)) {
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DBF_EVENT(3, "TCHAR:open: tape_find_device() failed\n");
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return PTR_ERR(device);
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}
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rc = tape_open(device);
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if (rc == 0) {
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filp->private_data = device;
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nonseekable_open(inode, filp);
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} else
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tape_put_device(device);
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return rc;
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}
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/*
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* Character frontend tape device release function.
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*/
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static int
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tapechar_release(struct inode *inode, struct file *filp)
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{
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struct tape_device *device;
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DBF_EVENT(6, "TCHAR:release: %x\n", iminor(inode));
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device = (struct tape_device *) filp->private_data;
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/*
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* If this is the rewinding tape minor then rewind. In that case we
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* write all required tapemarks. Otherwise only one to terminate the
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* file.
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*/
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if ((iminor(inode) & 1) != 0) {
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if (device->required_tapemarks)
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tape_std_terminate_write(device);
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tape_mtop(device, MTREW, 1);
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} else {
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if (device->required_tapemarks > 1) {
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if (tape_mtop(device, MTWEOF, 1) == 0)
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device->required_tapemarks--;
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}
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}
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if (device->char_data.idal_buf != NULL) {
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idal_buffer_free(device->char_data.idal_buf);
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device->char_data.idal_buf = NULL;
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}
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tape_release(device);
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filp->private_data = NULL;
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tape_put_device(device);
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return 0;
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}
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/*
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* Tape device io controls.
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*/
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static int
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__tapechar_ioctl(struct tape_device *device,
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unsigned int no, unsigned long data)
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{
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int rc;
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if (no == MTIOCTOP) {
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struct mtop op;
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if (copy_from_user(&op, (char __user *) data, sizeof(op)) != 0)
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return -EFAULT;
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if (op.mt_count < 0)
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return -EINVAL;
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/*
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* Operations that change tape position should write final
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* tapemarks.
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*/
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switch (op.mt_op) {
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case MTFSF:
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case MTBSF:
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case MTFSR:
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case MTBSR:
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case MTREW:
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case MTOFFL:
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case MTEOM:
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case MTRETEN:
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case MTBSFM:
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case MTFSFM:
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case MTSEEK:
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if (device->required_tapemarks)
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tape_std_terminate_write(device);
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default:
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;
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}
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rc = tape_mtop(device, op.mt_op, op.mt_count);
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if (op.mt_op == MTWEOF && rc == 0) {
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if (op.mt_count > device->required_tapemarks)
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device->required_tapemarks = 0;
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else
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device->required_tapemarks -= op.mt_count;
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}
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return rc;
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}
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if (no == MTIOCPOS) {
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/* MTIOCPOS: query the tape position. */
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struct mtpos pos;
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rc = tape_mtop(device, MTTELL, 1);
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if (rc < 0)
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return rc;
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pos.mt_blkno = rc;
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if (copy_to_user((char __user *) data, &pos, sizeof(pos)) != 0)
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return -EFAULT;
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return 0;
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}
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if (no == MTIOCGET) {
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/* MTIOCGET: query the tape drive status. */
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struct mtget get;
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memset(&get, 0, sizeof(get));
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get.mt_type = MT_ISUNKNOWN;
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get.mt_resid = 0 /* device->devstat.rescnt */;
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get.mt_dsreg = device->tape_state;
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/* FIXME: mt_gstat, mt_erreg, mt_fileno */
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get.mt_gstat = 0;
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get.mt_erreg = 0;
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get.mt_fileno = 0;
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get.mt_gstat = device->tape_generic_status;
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if (device->medium_state == MS_LOADED) {
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rc = tape_mtop(device, MTTELL, 1);
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if (rc < 0)
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return rc;
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if (rc == 0)
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get.mt_gstat |= GMT_BOT(~0);
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get.mt_blkno = rc;
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}
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if (copy_to_user((char __user *) data, &get, sizeof(get)) != 0)
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return -EFAULT;
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return 0;
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}
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/* Try the discipline ioctl function. */
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if (device->discipline->ioctl_fn == NULL)
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return -EINVAL;
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return device->discipline->ioctl_fn(device, no, data);
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}
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static long
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tapechar_ioctl(struct file *filp, unsigned int no, unsigned long data)
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{
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struct tape_device *device;
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long rc;
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DBF_EVENT(6, "TCHAR:ioct\n");
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device = (struct tape_device *) filp->private_data;
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mutex_lock(&device->mutex);
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rc = __tapechar_ioctl(device, no, data);
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mutex_unlock(&device->mutex);
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return rc;
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}
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#ifdef CONFIG_COMPAT
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static long
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tapechar_compat_ioctl(struct file *filp, unsigned int no, unsigned long data)
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{
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struct tape_device *device = filp->private_data;
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int rval = -ENOIOCTLCMD;
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unsigned long argp;
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/* The 'arg' argument of any ioctl function may only be used for
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* pointers because of the compat pointer conversion.
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* Consider this when adding new ioctls.
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*/
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argp = (unsigned long) compat_ptr(data);
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if (device->discipline->ioctl_fn) {
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mutex_lock(&device->mutex);
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rval = device->discipline->ioctl_fn(device, no, argp);
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mutex_unlock(&device->mutex);
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if (rval == -EINVAL)
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rval = -ENOIOCTLCMD;
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}
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return rval;
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}
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#endif /* CONFIG_COMPAT */
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/*
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* Initialize character device frontend.
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*/
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int
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tapechar_init (void)
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{
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dev_t dev;
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if (alloc_chrdev_region(&dev, 0, 256, "tape") != 0)
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return -1;
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tapechar_major = MAJOR(dev);
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return 0;
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}
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/*
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* cleanup
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*/
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void
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tapechar_exit(void)
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{
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unregister_chrdev_region(MKDEV(tapechar_major, 0), 256);
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}
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