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/slab.h>
26 #include <linux/ioport.h>
27 #include <linux/fcntl.h>
28 #include <linux/delay.h>
29 #include <linux/skbuff.h>
30 #include <linux/proc_fs.h>
31 #include <linux/vmalloc.h>
33 #include <linux/file.h>
34 #include <linux/poll.h>
35 #include <linux/init.h>
36 #include <linux/list.h>
37 #include <linux/smp_lock.h>
38 #include <linux/device.h>
40 #include <asm/system.h>
42 #include <asm/uaccess.h>
44 #include <linux/coda.h>
45 #include <linux/coda_linux.h>
46 #include <linux/coda_fs_i.h>
47 #include <linux/coda_psdev.h>
52 int coda_hard; /* allows signals during upcalls */
53 unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
56 struct venus_comm coda_comms[MAX_CODADEVS];
57 static struct class *coda_psdev_class;
63 static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
65 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
66 unsigned int mask = POLLOUT | POLLWRNORM;
68 poll_wait(file, &vcp->vc_waitq, wait);
69 if (!list_empty(&vcp->vc_pending))
70 mask |= POLLIN | POLLRDNORM;
75 static int coda_psdev_ioctl(struct inode * inode, struct file * filp,
76 unsigned int cmd, unsigned long arg)
81 case CIOC_KERNEL_VERSION:
82 data = CODA_KERNEL_VERSION;
83 return put_user(data, (int __user *) arg);
92 * Receive a message written by Venus to the psdev
95 static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
96 size_t nbytes, loff_t *off)
98 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
99 struct upc_req *req = NULL;
101 struct list_head *lh;
102 struct coda_in_hdr hdr;
103 ssize_t retval = 0, count = 0;
106 /* Peek at the opcode, uniquefier */
107 if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
110 if (DOWNCALL(hdr.opcode)) {
111 struct super_block *sb = NULL;
112 union outputArgs *dcbuf;
113 int size = sizeof(*dcbuf);
121 if ( nbytes < sizeof(struct coda_out_hdr) ) {
122 printk("coda_downcall opc %d uniq %d, not enough!\n",
123 hdr.opcode, hdr.unique);
127 if ( nbytes > size ) {
128 printk("Coda: downcall opc %d, uniq %d, too much!",
129 hdr.opcode, hdr.unique);
132 CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
133 if (copy_from_user(dcbuf, buf, nbytes)) {
134 CODA_FREE(dcbuf, nbytes);
139 /* what downcall errors does Venus handle ? */
141 error = coda_downcall(hdr.opcode, dcbuf, sb);
144 CODA_FREE(dcbuf, nbytes);
146 printk("psdev_write: coda_downcall error: %d\n", error);
154 /* Look for the message on the processing queue. */
156 list_for_each(lh, &vcp->vc_processing) {
157 tmp = list_entry(lh, struct upc_req , uc_chain);
158 if (tmp->uc_unique == hdr.unique) {
160 list_del(&req->uc_chain);
167 printk("psdev_write: msg (%d, %d) not found\n",
168 hdr.opcode, hdr.unique);
173 /* move data into response buffer. */
174 if (req->uc_outSize < nbytes) {
175 printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
176 req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique);
177 nbytes = req->uc_outSize; /* don't have more space! */
179 if (copy_from_user(req->uc_data, buf, nbytes)) {
180 req->uc_flags |= REQ_ABORT;
181 wake_up(&req->uc_sleep);
186 /* adjust outsize. is this useful ?? */
187 req->uc_outSize = nbytes;
188 req->uc_flags |= REQ_WRITE;
191 /* Convert filedescriptor into a file handle */
192 if (req->uc_opcode == CODA_OPEN_BY_FD) {
193 struct coda_open_by_fd_out *outp =
194 (struct coda_open_by_fd_out *)req->uc_data;
195 if (!outp->oh.result)
196 outp->fh = fget(outp->fd);
199 wake_up(&req->uc_sleep);
201 return(count ? count : retval);
205 * Read a message from the kernel to Venus
208 static ssize_t coda_psdev_read(struct file * file, char __user * buf,
209 size_t nbytes, loff_t *off)
211 DECLARE_WAITQUEUE(wait, current);
212 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
214 ssize_t retval = 0, count = 0;
221 add_wait_queue(&vcp->vc_waitq, &wait);
222 set_current_state(TASK_INTERRUPTIBLE);
224 while (list_empty(&vcp->vc_pending)) {
225 if (file->f_flags & O_NONBLOCK) {
229 if (signal_pending(current)) {
230 retval = -ERESTARTSYS;
236 set_current_state(TASK_RUNNING);
237 remove_wait_queue(&vcp->vc_waitq, &wait);
242 req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
243 list_del(&req->uc_chain);
245 /* Move the input args into userspace */
246 count = req->uc_inSize;
247 if (nbytes < req->uc_inSize) {
248 printk ("psdev_read: Venus read %ld bytes of %d in message\n",
249 (long)nbytes, req->uc_inSize);
253 if (copy_to_user(buf, req->uc_data, count))
256 /* If request was not a signal, enqueue and don't free */
257 if (!(req->uc_flags & REQ_ASYNC)) {
258 req->uc_flags |= REQ_READ;
259 list_add_tail(&(req->uc_chain), &vcp->vc_processing);
263 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
267 return (count ? count : retval);
270 static int coda_psdev_open(struct inode * inode, struct file * file)
272 struct venus_comm *vcp;
276 if (idx < 0 || idx >= MAX_CODADEVS)
282 vcp = &coda_comms[idx];
283 if (!vcp->vc_inuse) {
286 INIT_LIST_HEAD(&vcp->vc_pending);
287 INIT_LIST_HEAD(&vcp->vc_processing);
288 init_waitqueue_head(&vcp->vc_waitq);
292 file->private_data = vcp;
301 static int coda_psdev_release(struct inode * inode, struct file * file)
303 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
304 struct upc_req *req, *tmp;
306 if (!vcp || !vcp->vc_inuse ) {
307 printk("psdev_release: Not open.\n");
313 /* Wakeup clients so they can return. */
314 list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
315 list_del(&req->uc_chain);
317 /* Async requests need to be freed here */
318 if (req->uc_flags & REQ_ASYNC) {
319 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
323 req->uc_flags |= REQ_ABORT;
324 wake_up(&req->uc_sleep);
327 list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
328 list_del(&req->uc_chain);
330 req->uc_flags |= REQ_ABORT;
331 wake_up(&req->uc_sleep);
334 file->private_data = NULL;
341 static const struct file_operations coda_psdev_fops = {
342 .owner = THIS_MODULE,
343 .read = coda_psdev_read,
344 .write = coda_psdev_write,
345 .poll = coda_psdev_poll,
346 .ioctl = coda_psdev_ioctl,
347 .open = coda_psdev_open,
348 .release = coda_psdev_release,
351 static int init_coda_psdev(void)
354 if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
355 printk(KERN_ERR "coda_psdev: unable to get major %d\n",
359 coda_psdev_class = class_create(THIS_MODULE, "coda");
360 if (IS_ERR(coda_psdev_class)) {
361 err = PTR_ERR(coda_psdev_class);
364 for (i = 0; i < MAX_CODADEVS; i++)
365 device_create(coda_psdev_class, NULL,
366 MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i);
371 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
376 MODULE_AUTHOR("Jan Harkes, Peter J. Braam");
377 MODULE_DESCRIPTION("Coda Distributed File System VFS interface");
378 MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR);
379 MODULE_LICENSE("GPL");
380 MODULE_VERSION("6.6");
382 static int __init init_coda(void)
387 status = coda_init_inodecache();
390 status = init_coda_psdev();
392 printk("Problem (%d) in init_coda_psdev\n", status);
396 status = register_filesystem(&coda_fs_type);
398 printk("coda: failed to register filesystem!\n");
403 for (i = 0; i < MAX_CODADEVS; i++)
404 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
405 class_destroy(coda_psdev_class);
406 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
409 coda_destroy_inodecache();
414 static void __exit exit_coda(void)
418 err = unregister_filesystem(&coda_fs_type);
420 printk("coda: failed to unregister filesystem\n");
422 for (i = 0; i < MAX_CODADEVS; i++)
423 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
424 class_destroy(coda_psdev_class);
425 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
427 coda_destroy_inodecache();
430 module_init(init_coda);
431 module_exit(exit_coda);