fs/coda/psdev.c - kernel/msm-4.9 - Gitiles

 /*
  *      	An implementation of a loadable kernel mode driver providing
  *		multiple kernel/user space bidirectional communications links.
  *
  * 		Author: 	Alan Cox <alan@lxorguk.ukuu.org.uk>
  *
  *		This program is free software; you can redistribute it and/or
  *		modify it under the terms of the GNU General Public License
  *		as published by the Free Software Foundation; either version
  *		2 of the License, or (at your option) any later version.
  *
  *              Adapted to become the Linux 2.0 Coda pseudo device
  *              Peter  Braam  <braam@maths.ox.ac.uk>
  *              Michael Callahan <mjc@emmy.smith.edu>
  *
  *              Changes for Linux 2.1
  *              Copyright (c) 1997 Carnegie-Mellon University
  */

 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/major.h>
 #include <linux/time.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/ioport.h>
 #include <linux/fcntl.h>
 #include <linux/delay.h>
 #include <linux/skbuff.h>
 #include <linux/proc_fs.h>
 #include <linux/vmalloc.h>
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/poll.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/device.h>
 #include <linux/pid_namespace.h>
 #include <asm/io.h>
 #include <asm/poll.h>
 #include <linux/uaccess.h>

 #include <linux/coda.h>
 #include <linux/coda_psdev.h>

 #include "coda_linux.h"

 #include "coda_int.h"

 /* statistics */
 int           coda_hard;         /* allows signals during upcalls */
 unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */


 struct venus_comm coda_comms[MAX_CODADEVS];
 static struct class *coda_psdev_class;

 /*
  * Device operations
  */

 static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
 {
         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
 	unsigned int mask = POLLOUT | POLLWRNORM;

 	poll_wait(file, &vcp->vc_waitq, wait);
 	mutex_lock(&vcp->vc_mutex);
 	if (!list_empty(&vcp->vc_pending))
                 mask |= POLLIN | POLLRDNORM;
 	mutex_unlock(&vcp->vc_mutex);

 	return mask;
 }

 static long coda_psdev_ioctl(struct file * filp, unsigned int cmd, unsigned long arg)
 {
 	unsigned int data;

 	switch(cmd) {
 	case CIOC_KERNEL_VERSION:
 		data = CODA_KERNEL_VERSION;
 		return put_user(data, (int __user *) arg);
 	default:
 		return -ENOTTY;
 	}

 	return 0;
 }

 /*
  *	Receive a message written by Venus to the psdev
  */

 static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
 				size_t nbytes, loff_t *off)
 {
         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
         struct upc_req *req = NULL;
         struct upc_req *tmp;
 	struct list_head *lh;
 	struct coda_in_hdr hdr;
 	ssize_t retval = 0, count = 0;
 	int error;

         /* Peek at the opcode, uniquefier */
 	if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
 	        return -EFAULT;

         if (DOWNCALL(hdr.opcode)) {
 		union outputArgs *dcbuf;
 		int size = sizeof(*dcbuf);

 		if  ( nbytes < sizeof(struct coda_out_hdr) ) {
 			pr_warn("coda_downcall opc %d uniq %d, not enough!\n",
 				hdr.opcode, hdr.unique);
 			count = nbytes;
 			goto out;
 		}
 		if ( nbytes > size ) {
 			pr_warn("downcall opc %d, uniq %d, too much!",
 				hdr.opcode, hdr.unique);
 		        nbytes = size;
 		}
 		CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
 		if (copy_from_user(dcbuf, buf, nbytes)) {
 			CODA_FREE(dcbuf, nbytes);
 			retval = -EFAULT;
 			goto out;
 		}

 		/* what downcall errors does Venus handle ? */
 		error = coda_downcall(vcp, hdr.opcode, dcbuf);

 		CODA_FREE(dcbuf, nbytes);
 		if (error) {
 			pr_warn("%s: coda_downcall error: %d\n",
 				__func__, error);
 			retval = error;
 			goto out;
 		}
 		count = nbytes;
 		goto out;
 	}

 	/* Look for the message on the processing queue. */
 	mutex_lock(&vcp->vc_mutex);
 	list_for_each(lh, &vcp->vc_processing) {
 		tmp = list_entry(lh, struct upc_req , uc_chain);
 		if (tmp->uc_unique == hdr.unique) {
 			req = tmp;
 			list_del(&req->uc_chain);
 			break;
 		}
 	}
 	mutex_unlock(&vcp->vc_mutex);

 	if (!req) {
 		pr_warn("%s: msg (%d, %d) not found\n",
 			__func__, hdr.opcode, hdr.unique);
 		retval = -ESRCH;
 		goto out;
 	}

         /* move data into response buffer. */
 	if (req->uc_outSize < nbytes) {
 		pr_warn("%s: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
 			__func__, req->uc_outSize, (long)nbytes,
 			hdr.opcode, hdr.unique);
 		nbytes = req->uc_outSize; /* don't have more space! */
 	}
         if (copy_from_user(req->uc_data, buf, nbytes)) {
 		req->uc_flags |= CODA_REQ_ABORT;
 		wake_up(&req->uc_sleep);
 		retval = -EFAULT;
 		goto out;
 	}

 	/* adjust outsize. is this useful ?? */
 	req->uc_outSize = nbytes;
 	req->uc_flags |= CODA_REQ_WRITE;
 	count = nbytes;

 	/* Convert filedescriptor into a file handle */
 	if (req->uc_opcode == CODA_OPEN_BY_FD) {
 		struct coda_open_by_fd_out *outp =
 			(struct coda_open_by_fd_out *)req->uc_data;
 		if (!outp->oh.result) {
 			outp->fh = fget(outp->fd);
 			if (!outp->fh)
 				return -EBADF;
 		}
 	}

         wake_up(&req->uc_sleep);
 out:
         return(count ? count : retval);
 }

 /*
  *	Read a message from the kernel to Venus
  */

 static ssize_t coda_psdev_read(struct file * file, char __user * buf,
 			       size_t nbytes, loff_t *off)
 {
 	DECLARE_WAITQUEUE(wait, current);
         struct venus_comm *vcp = (struct venus_comm *) file->private_data;
         struct upc_req *req;
 	ssize_t retval = 0, count = 0;

 	if (nbytes == 0)
 		return 0;

 	mutex_lock(&vcp->vc_mutex);

 	add_wait_queue(&vcp->vc_waitq, &wait);
 	set_current_state(TASK_INTERRUPTIBLE);

 	while (list_empty(&vcp->vc_pending)) {
 		if (file->f_flags & O_NONBLOCK) {
 			retval = -EAGAIN;
 			break;
 		}
 		if (signal_pending(current)) {
 			retval = -ERESTARTSYS;
 			break;
 		}
 		mutex_unlock(&vcp->vc_mutex);
 		schedule();
 		mutex_lock(&vcp->vc_mutex);
 	}

 	set_current_state(TASK_RUNNING);
 	remove_wait_queue(&vcp->vc_waitq, &wait);

 	if (retval)
 		goto out;

 	req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
 	list_del(&req->uc_chain);

 	/* Move the input args into userspace */
 	count = req->uc_inSize;
 	if (nbytes < req->uc_inSize) {
 		pr_warn("%s: Venus read %ld bytes of %d in message\n",
 			__func__, (long)nbytes, req->uc_inSize);
 		count = nbytes;
         }

 	if (copy_to_user(buf, req->uc_data, count))
 	        retval = -EFAULT;

 	/* If request was not a signal, enqueue and don't free */
 	if (!(req->uc_flags & CODA_REQ_ASYNC)) {
 		req->uc_flags |= CODA_REQ_READ;
 		list_add_tail(&(req->uc_chain), &vcp->vc_processing);
 		goto out;
 	}

 	CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
 	kfree(req);
 out:
 	mutex_unlock(&vcp->vc_mutex);
 	return (count ? count : retval);
 }

 static int coda_psdev_open(struct inode * inode, struct file * file)
 {
 	struct venus_comm *vcp;
 	int idx, err;

 	if (task_active_pid_ns(current) != &init_pid_ns)
 		return -EINVAL;

 	if (current_user_ns() != &init_user_ns)
 		return -EINVAL;

 	idx = iminor(inode);
 	if (idx < 0 || idx >= MAX_CODADEVS)
 		return -ENODEV;

 	err = -EBUSY;
 	vcp = &coda_comms[idx];
 	mutex_lock(&vcp->vc_mutex);

 	if (!vcp->vc_inuse) {
 		vcp->vc_inuse++;

 		INIT_LIST_HEAD(&vcp->vc_pending);
 		INIT_LIST_HEAD(&vcp->vc_processing);
 		init_waitqueue_head(&vcp->vc_waitq);
 		vcp->vc_sb = NULL;
 		vcp->vc_seq = 0;

 		file->private_data = vcp;
 		err = 0;
 	}

 	mutex_unlock(&vcp->vc_mutex);
 	return err;
 }


 static int coda_psdev_release(struct inode * inode, struct file * file)
 {
 	struct venus_comm *vcp = (struct venus_comm *) file->private_data;
 	struct upc_req *req, *tmp;

 	if (!vcp || !vcp->vc_inuse ) {
 		pr_warn("%s: Not open.\n", __func__);
 		return -1;
 	}

 	mutex_lock(&vcp->vc_mutex);

 	/* Wakeup clients so they can return. */
 	list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
 		list_del(&req->uc_chain);

 		/* Async requests need to be freed here */
 		if (req->uc_flags & CODA_REQ_ASYNC) {
 			CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
 			kfree(req);
 			continue;
 		}
 		req->uc_flags |= CODA_REQ_ABORT;
 		wake_up(&req->uc_sleep);
 	}

 	list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
 		list_del(&req->uc_chain);

 		req->uc_flags |= CODA_REQ_ABORT;
 		wake_up(&req->uc_sleep);
 	}

 	file->private_data = NULL;
 	vcp->vc_inuse--;
 	mutex_unlock(&vcp->vc_mutex);
 	return 0;
 }


 static const struct file_operations coda_psdev_fops = {
 	.owner		= THIS_MODULE,
 	.read		= coda_psdev_read,
 	.write		= coda_psdev_write,
 	.poll		= coda_psdev_poll,
 	.unlocked_ioctl	= coda_psdev_ioctl,
 	.open		= coda_psdev_open,
 	.release	= coda_psdev_release,
 	.llseek		= noop_llseek,
 };

 static int init_coda_psdev(void)
 {
 	int i, err = 0;
 	if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
 		pr_err("%s: unable to get major %d\n",
 		       __func__, CODA_PSDEV_MAJOR);
               return -EIO;
 	}
 	coda_psdev_class = class_create(THIS_MODULE, "coda");
 	if (IS_ERR(coda_psdev_class)) {
 		err = PTR_ERR(coda_psdev_class);
 		goto out_chrdev;
 	}
 	for (i = 0; i < MAX_CODADEVS; i++) {
 		mutex_init(&(&coda_comms[i])->vc_mutex);
 		device_create(coda_psdev_class, NULL,
 			      MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i);
 	}
 	coda_sysctl_init();
 	goto out;

 out_chrdev:
 	unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
 out:
 	return err;
 }

 MODULE_AUTHOR("Jan Harkes, Peter J. Braam");
 MODULE_DESCRIPTION("Coda Distributed File System VFS interface");
 MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR);
 MODULE_LICENSE("GPL");
 MODULE_VERSION("6.6");

 static int __init init_coda(void)
 {
 	int status;
 	int i;

 	status = coda_init_inodecache();
 	if (status)
 		goto out2;
 	status = init_coda_psdev();
 	if ( status ) {
 		pr_warn("Problem (%d) in init_coda_psdev\n", status);
 		goto out1;
 	}

 	status = register_filesystem(&coda_fs_type);
 	if (status) {
 		pr_warn("failed to register filesystem!\n");
 		goto out;
 	}
 	return 0;
 out:
 	for (i = 0; i < MAX_CODADEVS; i++)
 		device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
 	class_destroy(coda_psdev_class);
 	unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
 	coda_sysctl_clean();
 out1:
 	coda_destroy_inodecache();
 out2:
 	return status;
 }

 static void __exit exit_coda(void)
 {
         int err, i;

 	err = unregister_filesystem(&coda_fs_type);
 	if (err != 0)
 		pr_warn("failed to unregister filesystem\n");
 	for (i = 0; i < MAX_CODADEVS; i++)
 		device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
 	class_destroy(coda_psdev_class);
 	unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
 	coda_sysctl_clean();
 	coda_destroy_inodecache();
 }

 module_init(init_coda);
 module_exit(exit_coda);
	/*
	* An implementation of a loadable kernel mode driver providing
	* multiple kernel/user space bidirectional communications links.
	*
	* Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	* Adapted to become the Linux 2.0 Coda pseudo device
	* Peter Braam <braam@maths.ox.ac.uk>
	* Michael Callahan <mjc@emmy.smith.edu>
	*
	* Changes for Linux 2.1
	* Copyright (c) 1997 Carnegie-Mellon University
	*/

	#include <linux/module.h>
	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/major.h>
	#include <linux/time.h>
	#include <linux/sched.h>
	#include <linux/slab.h>
	#include <linux/ioport.h>
	#include <linux/fcntl.h>
	#include <linux/delay.h>
	#include <linux/skbuff.h>
	#include <linux/proc_fs.h>
	#include <linux/vmalloc.h>
	#include <linux/fs.h>
	#include <linux/file.h>
	#include <linux/poll.h>
	#include <linux/init.h>
	#include <linux/list.h>
	#include <linux/mutex.h>
	#include <linux/device.h>
	#include <linux/pid_namespace.h>
	#include <asm/io.h>
	#include <asm/poll.h>
	#include <linux/uaccess.h>

	#include <linux/coda.h>
	#include <linux/coda_psdev.h>

	#include "coda_linux.h"

	#include "coda_int.h"

	/* statistics */
	int coda_hard; /* allows signals during upcalls */
	unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */


	struct venus_comm coda_comms[MAX_CODADEVS];
	static struct class *coda_psdev_class;

	/*
	* Device operations
	*/

	static unsigned int coda_psdev_poll(struct file file, poll_table wait)
	{
	struct venus_comm vcp = (struct venus_comm ) file->private_data;
	unsigned int mask = POLLOUT \| POLLWRNORM;

	poll_wait(file, &vcp->vc_waitq, wait);
	mutex_lock(&vcp->vc_mutex);
	if (!list_empty(&vcp->vc_pending))
	mask \|= POLLIN \| POLLRDNORM;
	mutex_unlock(&vcp->vc_mutex);

	return mask;
	}

	static long coda_psdev_ioctl(struct file * filp, unsigned int cmd, unsigned long arg)
	{
	unsigned int data;

	switch(cmd) {
	case CIOC_KERNEL_VERSION:
	data = CODA_KERNEL_VERSION;
	return put_user(data, (int __user *) arg);
	default:
	return -ENOTTY;
	}

	return 0;
	}

	/*
	* Receive a message written by Venus to the psdev
	*/

	static ssize_t coda_psdev_write(struct file file, const char __user buf,
	size_t nbytes, loff_t *off)
	{
	struct venus_comm vcp = (struct venus_comm ) file->private_data;
	struct upc_req *req = NULL;
	struct upc_req *tmp;
	struct list_head *lh;
	struct coda_in_hdr hdr;
	ssize_t retval = 0, count = 0;
	int error;

	/* Peek at the opcode, uniquefier */
	if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
	return -EFAULT;

	if (DOWNCALL(hdr.opcode)) {
	union outputArgs *dcbuf;
	int size = sizeof(*dcbuf);

	if ( nbytes < sizeof(struct coda_out_hdr) ) {
	pr_warn("coda_downcall opc %d uniq %d, not enough!\n",
	hdr.opcode, hdr.unique);
	count = nbytes;
	goto out;
	}
	if ( nbytes > size ) {
	pr_warn("downcall opc %d, uniq %d, too much!",
	hdr.opcode, hdr.unique);
	nbytes = size;
	}
	CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
	if (copy_from_user(dcbuf, buf, nbytes)) {
	CODA_FREE(dcbuf, nbytes);
	retval = -EFAULT;
	goto out;
	}

	/* what downcall errors does Venus handle ? */
	error = coda_downcall(vcp, hdr.opcode, dcbuf);

	CODA_FREE(dcbuf, nbytes);
	if (error) {
	pr_warn("%s: coda_downcall error: %d\n",
	__func__, error);
	retval = error;
	goto out;
	}
	count = nbytes;
	goto out;
	}

	/* Look for the message on the processing queue. */
	mutex_lock(&vcp->vc_mutex);
	list_for_each(lh, &vcp->vc_processing) {
	tmp = list_entry(lh, struct upc_req , uc_chain);
	if (tmp->uc_unique == hdr.unique) {
	req = tmp;
	list_del(&req->uc_chain);
	break;
	}
	}
	mutex_unlock(&vcp->vc_mutex);

	if (!req) {
	pr_warn("%s: msg (%d, %d) not found\n",
	__func__, hdr.opcode, hdr.unique);
	retval = -ESRCH;
	goto out;
	}

	/* move data into response buffer. */
	if (req->uc_outSize < nbytes) {
	pr_warn("%s: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
	__func__, req->uc_outSize, (long)nbytes,
	hdr.opcode, hdr.unique);
	nbytes = req->uc_outSize; /* don't have more space! */
	}
	if (copy_from_user(req->uc_data, buf, nbytes)) {
	req->uc_flags \|= CODA_REQ_ABORT;
	wake_up(&req->uc_sleep);
	retval = -EFAULT;
	goto out;
	}

	/* adjust outsize. is this useful ?? */
	req->uc_outSize = nbytes;
	req->uc_flags \|= CODA_REQ_WRITE;
	count = nbytes;

	/* Convert filedescriptor into a file handle */
	if (req->uc_opcode == CODA_OPEN_BY_FD) {
	struct coda_open_by_fd_out *outp =
	(struct coda_open_by_fd_out *)req->uc_data;
	if (!outp->oh.result) {
	outp->fh = fget(outp->fd);
	if (!outp->fh)
	return -EBADF;
	}
	}

	wake_up(&req->uc_sleep);
	out:
	return(count ? count : retval);
	}

	/*
	* Read a message from the kernel to Venus
	*/

	static ssize_t coda_psdev_read(struct file * file, char __user * buf,
	size_t nbytes, loff_t *off)
	{
	DECLARE_WAITQUEUE(wait, current);
	struct venus_comm vcp = (struct venus_comm ) file->private_data;
	struct upc_req *req;
	ssize_t retval = 0, count = 0;

	if (nbytes == 0)
	return 0;

	mutex_lock(&vcp->vc_mutex);

	add_wait_queue(&vcp->vc_waitq, &wait);
	set_current_state(TASK_INTERRUPTIBLE);

	while (list_empty(&vcp->vc_pending)) {
	if (file->f_flags & O_NONBLOCK) {
	retval = -EAGAIN;
	break;
	}
	if (signal_pending(current)) {
	retval = -ERESTARTSYS;
	break;
	}
	mutex_unlock(&vcp->vc_mutex);
	schedule();
	mutex_lock(&vcp->vc_mutex);
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(&vcp->vc_waitq, &wait);

	if (retval)
	goto out;

	req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
	list_del(&req->uc_chain);

	/* Move the input args into userspace */
	count = req->uc_inSize;
	if (nbytes < req->uc_inSize) {
	pr_warn("%s: Venus read %ld bytes of %d in message\n",
	__func__, (long)nbytes, req->uc_inSize);
	count = nbytes;
	}

	if (copy_to_user(buf, req->uc_data, count))
	retval = -EFAULT;

	/* If request was not a signal, enqueue and don't free */
	if (!(req->uc_flags & CODA_REQ_ASYNC)) {
	req->uc_flags \|= CODA_REQ_READ;
	list_add_tail(&(req->uc_chain), &vcp->vc_processing);
	goto out;
	}

	CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
	kfree(req);
	out:
	mutex_unlock(&vcp->vc_mutex);
	return (count ? count : retval);
	}

	static int coda_psdev_open(struct inode * inode, struct file * file)
	{
	struct venus_comm *vcp;
	int idx, err;

	if (task_active_pid_ns(current) != &init_pid_ns)
	return -EINVAL;

	if (current_user_ns() != &init_user_ns)
	return -EINVAL;

	idx = iminor(inode);
	if (idx < 0 \|\| idx >= MAX_CODADEVS)
	return -ENODEV;

	err = -EBUSY;
	vcp = &coda_comms[idx];
	mutex_lock(&vcp->vc_mutex);

	if (!vcp->vc_inuse) {
	vcp->vc_inuse++;

	INIT_LIST_HEAD(&vcp->vc_pending);
	INIT_LIST_HEAD(&vcp->vc_processing);
	init_waitqueue_head(&vcp->vc_waitq);
	vcp->vc_sb = NULL;
	vcp->vc_seq = 0;

	file->private_data = vcp;
	err = 0;
	}

	mutex_unlock(&vcp->vc_mutex);
	return err;
	}


	static int coda_psdev_release(struct inode * inode, struct file * file)
	{
	struct venus_comm vcp = (struct venus_comm ) file->private_data;
	struct upc_req req, tmp;

	if (!vcp \|\| !vcp->vc_inuse ) {
	pr_warn("%s: Not open.\n", __func__);
	return -1;
	}

	mutex_lock(&vcp->vc_mutex);

	/* Wakeup clients so they can return. */
	list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
	list_del(&req->uc_chain);

	/* Async requests need to be freed here */
	if (req->uc_flags & CODA_REQ_ASYNC) {
	CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
	kfree(req);
	continue;
	}
	req->uc_flags \|= CODA_REQ_ABORT;
	wake_up(&req->uc_sleep);
	}

	list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
	list_del(&req->uc_chain);

	req->uc_flags \|= CODA_REQ_ABORT;
	wake_up(&req->uc_sleep);
	}

	file->private_data = NULL;
	vcp->vc_inuse--;
	mutex_unlock(&vcp->vc_mutex);
	return 0;
	}


	static const struct file_operations coda_psdev_fops = {
	.owner = THIS_MODULE,
	.read = coda_psdev_read,
	.write = coda_psdev_write,
	.poll = coda_psdev_poll,
	.unlocked_ioctl = coda_psdev_ioctl,
	.open = coda_psdev_open,
	.release = coda_psdev_release,
	.llseek = noop_llseek,
	};

	static int init_coda_psdev(void)
	{
	int i, err = 0;
	if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
	pr_err("%s: unable to get major %d\n",
	__func__, CODA_PSDEV_MAJOR);
	return -EIO;
	}
	coda_psdev_class = class_create(THIS_MODULE, "coda");
	if (IS_ERR(coda_psdev_class)) {
	err = PTR_ERR(coda_psdev_class);
	goto out_chrdev;
	}
	for (i = 0; i < MAX_CODADEVS; i++) {
	mutex_init(&(&coda_comms[i])->vc_mutex);
	device_create(coda_psdev_class, NULL,
	MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i);
	}
	coda_sysctl_init();
	goto out;

	out_chrdev:
	unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
	out:
	return err;
	}

	MODULE_AUTHOR("Jan Harkes, Peter J. Braam");
	MODULE_DESCRIPTION("Coda Distributed File System VFS interface");
	MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR);
	MODULE_LICENSE("GPL");
	MODULE_VERSION("6.6");

	static int __init init_coda(void)
	{
	int status;
	int i;

	status = coda_init_inodecache();
	if (status)
	goto out2;
	status = init_coda_psdev();
	if ( status ) {
	pr_warn("Problem (%d) in init_coda_psdev\n", status);
	goto out1;
	}

	status = register_filesystem(&coda_fs_type);
	if (status) {
	pr_warn("failed to register filesystem!\n");
	goto out;
	}
	return 0;
	out:
	for (i = 0; i < MAX_CODADEVS; i++)
	device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
	class_destroy(coda_psdev_class);
	unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
	coda_sysctl_clean();
	out1:
	coda_destroy_inodecache();
	out2:
	return status;
	}

	static void __exit exit_coda(void)
	{
	int err, i;

	err = unregister_filesystem(&coda_fs_type);
	if (err != 0)
	pr_warn("failed to unregister filesystem\n");
	for (i = 0; i < MAX_CODADEVS; i++)
	device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
	class_destroy(coda_psdev_class);
	unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
	coda_sysctl_clean();
	coda_destroy_inodecache();
	}

	module_init(init_coda);
	module_exit(exit_coda);