2 * An implementation of a loadable kernel mode driver providing
3 * multiple kernel/user space bidirectional communications links.
5 * Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
12 * Adapted to become the Linux 2.0 Coda pseudo device
13 * Peter Braam <braam@maths.ox.ac.uk>
14 * Michael Callahan <mjc@emmy.smith.edu>
16 * Changes for Linux 2.1
17 * Copyright (c) 1997 Carnegie-Mellon University
20 #include <linux/module.h>
21 #include <linux/errno.h>
22 #include <linux/kernel.h>
23 #include <linux/major.h>
24 #include <linux/time.h>
25 #include <linux/sched.h>
26 #include <linux/slab.h>
27 #include <linux/ioport.h>
28 #include <linux/fcntl.h>
29 #include <linux/delay.h>
30 #include <linux/skbuff.h>
31 #include <linux/proc_fs.h>
32 #include <linux/vmalloc.h>
34 #include <linux/file.h>
35 #include <linux/poll.h>
36 #include <linux/init.h>
37 #include <linux/list.h>
38 #include <linux/mutex.h>
39 #include <linux/device.h>
40 #include <linux/pid_namespace.h>
43 #include <asm/uaccess.h>
45 #include <linux/coda.h>
46 #include <linux/coda_psdev.h>
48 #include "coda_linux.h"
53 int coda_hard; /* allows signals during upcalls */
54 unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
57 struct venus_comm coda_comms[MAX_CODADEVS];
58 static struct class *coda_psdev_class;
64 static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
66 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
67 unsigned int mask = POLLOUT | POLLWRNORM;
69 poll_wait(file, &vcp->vc_waitq, wait);
70 mutex_lock(&vcp->vc_mutex);
71 if (!list_empty(&vcp->vc_pending))
72 mask |= POLLIN | POLLRDNORM;
73 mutex_unlock(&vcp->vc_mutex);
78 static long coda_psdev_ioctl(struct file * filp, unsigned int cmd, unsigned long arg)
83 case CIOC_KERNEL_VERSION:
84 data = CODA_KERNEL_VERSION;
85 return put_user(data, (int __user *) arg);
94 * Receive a message written by Venus to the psdev
97 static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
98 size_t nbytes, loff_t *off)
100 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
101 struct upc_req *req = NULL;
103 struct list_head *lh;
104 struct coda_in_hdr hdr;
105 ssize_t retval = 0, count = 0;
108 /* Peek at the opcode, uniquefier */
109 if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
112 if (DOWNCALL(hdr.opcode)) {
113 union outputArgs *dcbuf;
114 int size = sizeof(*dcbuf);
116 if ( nbytes < sizeof(struct coda_out_hdr) ) {
117 pr_warn("coda_downcall opc %d uniq %d, not enough!\n",
118 hdr.opcode, hdr.unique);
122 if ( nbytes > size ) {
123 pr_warn("Coda: downcall opc %d, uniq %d, too much!",
124 hdr.opcode, hdr.unique);
127 CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
128 if (copy_from_user(dcbuf, buf, nbytes)) {
129 CODA_FREE(dcbuf, nbytes);
134 /* what downcall errors does Venus handle ? */
135 error = coda_downcall(vcp, hdr.opcode, dcbuf);
137 CODA_FREE(dcbuf, nbytes);
139 pr_warn("psdev_write: coda_downcall error: %d\n",
148 /* Look for the message on the processing queue. */
149 mutex_lock(&vcp->vc_mutex);
150 list_for_each(lh, &vcp->vc_processing) {
151 tmp = list_entry(lh, struct upc_req , uc_chain);
152 if (tmp->uc_unique == hdr.unique) {
154 list_del(&req->uc_chain);
158 mutex_unlock(&vcp->vc_mutex);
161 pr_warn("psdev_write: msg (%d, %d) not found\n",
162 hdr.opcode, hdr.unique);
167 /* move data into response buffer. */
168 if (req->uc_outSize < nbytes) {
169 pr_warn("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
170 req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique);
171 nbytes = req->uc_outSize; /* don't have more space! */
173 if (copy_from_user(req->uc_data, buf, nbytes)) {
174 req->uc_flags |= CODA_REQ_ABORT;
175 wake_up(&req->uc_sleep);
180 /* adjust outsize. is this useful ?? */
181 req->uc_outSize = nbytes;
182 req->uc_flags |= CODA_REQ_WRITE;
185 /* Convert filedescriptor into a file handle */
186 if (req->uc_opcode == CODA_OPEN_BY_FD) {
187 struct coda_open_by_fd_out *outp =
188 (struct coda_open_by_fd_out *)req->uc_data;
189 if (!outp->oh.result)
190 outp->fh = fget(outp->fd);
193 wake_up(&req->uc_sleep);
195 return(count ? count : retval);
199 * Read a message from the kernel to Venus
202 static ssize_t coda_psdev_read(struct file * file, char __user * buf,
203 size_t nbytes, loff_t *off)
205 DECLARE_WAITQUEUE(wait, current);
206 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
208 ssize_t retval = 0, count = 0;
213 mutex_lock(&vcp->vc_mutex);
215 add_wait_queue(&vcp->vc_waitq, &wait);
216 set_current_state(TASK_INTERRUPTIBLE);
218 while (list_empty(&vcp->vc_pending)) {
219 if (file->f_flags & O_NONBLOCK) {
223 if (signal_pending(current)) {
224 retval = -ERESTARTSYS;
227 mutex_unlock(&vcp->vc_mutex);
229 mutex_lock(&vcp->vc_mutex);
232 set_current_state(TASK_RUNNING);
233 remove_wait_queue(&vcp->vc_waitq, &wait);
238 req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
239 list_del(&req->uc_chain);
241 /* Move the input args into userspace */
242 count = req->uc_inSize;
243 if (nbytes < req->uc_inSize) {
244 pr_warn("psdev_read: Venus read %ld bytes of %d in message\n",
245 (long)nbytes, req->uc_inSize);
249 if (copy_to_user(buf, req->uc_data, count))
252 /* If request was not a signal, enqueue and don't free */
253 if (!(req->uc_flags & CODA_REQ_ASYNC)) {
254 req->uc_flags |= CODA_REQ_READ;
255 list_add_tail(&(req->uc_chain), &vcp->vc_processing);
259 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
262 mutex_unlock(&vcp->vc_mutex);
263 return (count ? count : retval);
266 static int coda_psdev_open(struct inode * inode, struct file * file)
268 struct venus_comm *vcp;
271 if (task_active_pid_ns(current) != &init_pid_ns)
274 if (current_user_ns() != &init_user_ns)
278 if (idx < 0 || idx >= MAX_CODADEVS)
282 vcp = &coda_comms[idx];
283 mutex_lock(&vcp->vc_mutex);
285 if (!vcp->vc_inuse) {
288 INIT_LIST_HEAD(&vcp->vc_pending);
289 INIT_LIST_HEAD(&vcp->vc_processing);
290 init_waitqueue_head(&vcp->vc_waitq);
294 file->private_data = vcp;
298 mutex_unlock(&vcp->vc_mutex);
303 static int coda_psdev_release(struct inode * inode, struct file * file)
305 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
306 struct upc_req *req, *tmp;
308 if (!vcp || !vcp->vc_inuse ) {
309 pr_warn("psdev_release: Not open.\n");
313 mutex_lock(&vcp->vc_mutex);
315 /* Wakeup clients so they can return. */
316 list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
317 list_del(&req->uc_chain);
319 /* Async requests need to be freed here */
320 if (req->uc_flags & CODA_REQ_ASYNC) {
321 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
325 req->uc_flags |= CODA_REQ_ABORT;
326 wake_up(&req->uc_sleep);
329 list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
330 list_del(&req->uc_chain);
332 req->uc_flags |= CODA_REQ_ABORT;
333 wake_up(&req->uc_sleep);
336 file->private_data = NULL;
338 mutex_unlock(&vcp->vc_mutex);
343 static const struct file_operations coda_psdev_fops = {
344 .owner = THIS_MODULE,
345 .read = coda_psdev_read,
346 .write = coda_psdev_write,
347 .poll = coda_psdev_poll,
348 .unlocked_ioctl = coda_psdev_ioctl,
349 .open = coda_psdev_open,
350 .release = coda_psdev_release,
351 .llseek = noop_llseek,
354 static int init_coda_psdev(void)
357 if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
358 pr_err("coda_psdev: unable to get major %d\n",
362 coda_psdev_class = class_create(THIS_MODULE, "coda");
363 if (IS_ERR(coda_psdev_class)) {
364 err = PTR_ERR(coda_psdev_class);
367 for (i = 0; i < MAX_CODADEVS; i++) {
368 mutex_init(&(&coda_comms[i])->vc_mutex);
369 device_create(coda_psdev_class, NULL,
370 MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i);
376 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
381 MODULE_AUTHOR("Jan Harkes, Peter J. Braam");
382 MODULE_DESCRIPTION("Coda Distributed File System VFS interface");
383 MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR);
384 MODULE_LICENSE("GPL");
385 MODULE_VERSION("6.6");
387 static int __init init_coda(void)
392 status = coda_init_inodecache();
395 status = init_coda_psdev();
397 pr_warn("Problem (%d) in init_coda_psdev\n", status);
401 status = register_filesystem(&coda_fs_type);
403 pr_warn("coda: failed to register filesystem!\n");
408 for (i = 0; i < MAX_CODADEVS; i++)
409 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
410 class_destroy(coda_psdev_class);
411 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
414 coda_destroy_inodecache();
419 static void __exit exit_coda(void)
423 err = unregister_filesystem(&coda_fs_type);
425 pr_warn("coda: failed to unregister filesystem\n");
426 for (i = 0; i < MAX_CODADEVS; i++)
427 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
428 class_destroy(coda_psdev_class);
429 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
431 coda_destroy_inodecache();
434 module_init(init_coda);
435 module_exit(exit_coda);