blob: 803aacf0d49c29576252dcbe2aa2ff8e73d9e5f5 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * An implementation of a loadable kernel mode driver providing
3 * multiple kernel/user space bidirectional communications links.
4 *
5 * Author: Alan Cox <alan@redhat.com>
6 *
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.
11 *
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>
15 *
16 * Changes for Linux 2.1
17 * Copyright (c) 1997 Carnegie-Mellon University
18 */
19
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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <linux/vmalloc.h>
32#include <linux/fs.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>
39#include <asm/io.h>
40#include <asm/system.h>
41#include <asm/poll.h>
42#include <asm/uaccess.h>
43
44#include <linux/coda.h>
45#include <linux/coda_linux.h>
46#include <linux/coda_fs_i.h>
47#include <linux/coda_psdev.h>
48#include <linux/coda_proc.h>
49
Adrian Bunkc98d8cf2006-03-24 03:15:53 -080050#include "coda_int.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Adrian Bunkc98d8cf2006-03-24 03:15:53 -080052#define upc_free(r) kfree(r)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
54/* statistics */
55int coda_hard; /* allows signals during upcalls */
56unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
57
58
59struct venus_comm coda_comms[MAX_CODADEVS];
gregkh@suse.de1db560a2005-03-23 10:02:26 -080060static struct class *coda_psdev_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62/*
63 * Device operations
64 */
65
66static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
67{
68 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
69 unsigned int mask = POLLOUT | POLLWRNORM;
70
71 poll_wait(file, &vcp->vc_waitq, wait);
72 if (!list_empty(&vcp->vc_pending))
73 mask |= POLLIN | POLLRDNORM;
74
75 return mask;
76}
77
78static int coda_psdev_ioctl(struct inode * inode, struct file * filp,
79 unsigned int cmd, unsigned long arg)
80{
81 unsigned int data;
82
83 switch(cmd) {
84 case CIOC_KERNEL_VERSION:
85 data = CODA_KERNEL_VERSION;
86 return put_user(data, (int __user *) arg);
87 default:
88 return -ENOTTY;
89 }
90
91 return 0;
92}
93
94/*
95 * Receive a message written by Venus to the psdev
96 */
97
98static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
99 size_t nbytes, loff_t *off)
100{
101 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
102 struct upc_req *req = NULL;
103 struct upc_req *tmp;
104 struct list_head *lh;
105 struct coda_in_hdr hdr;
106 ssize_t retval = 0, count = 0;
107 int error;
108
109 /* Peek at the opcode, uniquefier */
110 if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
111 return -EFAULT;
112
113 if (DOWNCALL(hdr.opcode)) {
114 struct super_block *sb = NULL;
115 union outputArgs *dcbuf;
116 int size = sizeof(*dcbuf);
117
118 sb = vcp->vc_sb;
119 if ( !sb ) {
120 count = nbytes;
121 goto out;
122 }
123
124 if ( nbytes < sizeof(struct coda_out_hdr) ) {
125 printk("coda_downcall opc %d uniq %d, not enough!\n",
126 hdr.opcode, hdr.unique);
127 count = nbytes;
128 goto out;
129 }
130 if ( nbytes > size ) {
131 printk("Coda: downcall opc %d, uniq %d, too much!",
132 hdr.opcode, hdr.unique);
133 nbytes = size;
134 }
135 CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
136 if (copy_from_user(dcbuf, buf, nbytes)) {
137 CODA_FREE(dcbuf, nbytes);
138 retval = -EFAULT;
139 goto out;
140 }
141
142 /* what downcall errors does Venus handle ? */
143 lock_kernel();
144 error = coda_downcall(hdr.opcode, dcbuf, sb);
145 unlock_kernel();
146
147 CODA_FREE(dcbuf, nbytes);
148 if (error) {
149 printk("psdev_write: coda_downcall error: %d\n", error);
150 retval = error;
151 goto out;
152 }
153 count = nbytes;
154 goto out;
155 }
156
157 /* Look for the message on the processing queue. */
158 lock_kernel();
159 list_for_each(lh, &vcp->vc_processing) {
160 tmp = list_entry(lh, struct upc_req , uc_chain);
161 if (tmp->uc_unique == hdr.unique) {
162 req = tmp;
163 list_del(&req->uc_chain);
164 break;
165 }
166 }
167 unlock_kernel();
168
169 if (!req) {
170 printk("psdev_write: msg (%d, %d) not found\n",
171 hdr.opcode, hdr.unique);
172 retval = -ESRCH;
173 goto out;
174 }
175
176 /* move data into response buffer. */
177 if (req->uc_outSize < nbytes) {
178 printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
179 req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique);
180 nbytes = req->uc_outSize; /* don't have more space! */
181 }
182 if (copy_from_user(req->uc_data, buf, nbytes)) {
183 req->uc_flags |= REQ_ABORT;
184 wake_up(&req->uc_sleep);
185 retval = -EFAULT;
186 goto out;
187 }
188
189 /* adjust outsize. is this useful ?? */
190 req->uc_outSize = nbytes;
191 req->uc_flags |= REQ_WRITE;
192 count = nbytes;
193
194 /* Convert filedescriptor into a file handle */
195 if (req->uc_opcode == CODA_OPEN_BY_FD) {
196 struct coda_open_by_fd_out *outp =
197 (struct coda_open_by_fd_out *)req->uc_data;
198 outp->fh = fget(outp->fd);
199 }
200
201 wake_up(&req->uc_sleep);
202out:
203 return(count ? count : retval);
204}
205
206/*
207 * Read a message from the kernel to Venus
208 */
209
210static ssize_t coda_psdev_read(struct file * file, char __user * buf,
211 size_t nbytes, loff_t *off)
212{
213 DECLARE_WAITQUEUE(wait, current);
214 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
215 struct upc_req *req;
216 ssize_t retval = 0, count = 0;
217
218 if (nbytes == 0)
219 return 0;
220
221 lock_kernel();
222
223 add_wait_queue(&vcp->vc_waitq, &wait);
224 set_current_state(TASK_INTERRUPTIBLE);
225
226 while (list_empty(&vcp->vc_pending)) {
227 if (file->f_flags & O_NONBLOCK) {
228 retval = -EAGAIN;
229 break;
230 }
231 if (signal_pending(current)) {
232 retval = -ERESTARTSYS;
233 break;
234 }
235 schedule();
236 }
237
238 set_current_state(TASK_RUNNING);
239 remove_wait_queue(&vcp->vc_waitq, &wait);
240
241 if (retval)
242 goto out;
243
244 req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
245 list_del(&req->uc_chain);
246
247 /* Move the input args into userspace */
248 count = req->uc_inSize;
249 if (nbytes < req->uc_inSize) {
250 printk ("psdev_read: Venus read %ld bytes of %d in message\n",
251 (long)nbytes, req->uc_inSize);
252 count = nbytes;
253 }
254
255 if (copy_to_user(buf, req->uc_data, count))
256 retval = -EFAULT;
257
258 /* If request was not a signal, enqueue and don't free */
259 if (!(req->uc_flags & REQ_ASYNC)) {
260 req->uc_flags |= REQ_READ;
Akinobu Mita8e130592006-06-26 00:24:37 -0700261 list_add_tail(&(req->uc_chain), &vcp->vc_processing);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 goto out;
263 }
264
265 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
266 upc_free(req);
267out:
268 unlock_kernel();
269 return (count ? count : retval);
270}
271
272static int coda_psdev_open(struct inode * inode, struct file * file)
273{
274 struct venus_comm *vcp;
275 int idx;
276
277 lock_kernel();
278 idx = iminor(inode);
279 if(idx >= MAX_CODADEVS) {
280 unlock_kernel();
281 return -ENODEV;
282 }
283
284 vcp = &coda_comms[idx];
285 if(vcp->vc_inuse) {
286 unlock_kernel();
287 return -EBUSY;
288 }
289
290 if (!vcp->vc_inuse++) {
291 INIT_LIST_HEAD(&vcp->vc_pending);
292 INIT_LIST_HEAD(&vcp->vc_processing);
293 init_waitqueue_head(&vcp->vc_waitq);
294 vcp->vc_sb = NULL;
295 vcp->vc_seq = 0;
296 }
297
298 file->private_data = vcp;
299
300 unlock_kernel();
301 return 0;
302}
303
304
305static int coda_psdev_release(struct inode * inode, struct file * file)
306{
307 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
308 struct upc_req *req, *tmp;
309
310 lock_kernel();
311 if ( !vcp->vc_inuse ) {
312 unlock_kernel();
313 printk("psdev_release: Not open.\n");
314 return -1;
315 }
316
317 if (--vcp->vc_inuse) {
318 unlock_kernel();
319 return 0;
320 }
321
322 /* Wakeup clients so they can return. */
323 list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
324 /* Async requests need to be freed here */
325 if (req->uc_flags & REQ_ASYNC) {
326 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
327 upc_free(req);
328 continue;
329 }
330 req->uc_flags |= REQ_ABORT;
331 wake_up(&req->uc_sleep);
332 }
333
334 list_for_each_entry(req, &vcp->vc_processing, uc_chain) {
335 req->uc_flags |= REQ_ABORT;
336 wake_up(&req->uc_sleep);
337 }
338
339 unlock_kernel();
340 return 0;
341}
342
343
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800344static const struct file_operations coda_psdev_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 .owner = THIS_MODULE,
346 .read = coda_psdev_read,
347 .write = coda_psdev_write,
348 .poll = coda_psdev_poll,
349 .ioctl = coda_psdev_ioctl,
350 .open = coda_psdev_open,
351 .release = coda_psdev_release,
352};
353
354static int init_coda_psdev(void)
355{
356 int i, err = 0;
357 if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
358 printk(KERN_ERR "coda_psdev: unable to get major %d\n",
359 CODA_PSDEV_MAJOR);
360 return -EIO;
361 }
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800362 coda_psdev_class = class_create(THIS_MODULE, "coda");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 if (IS_ERR(coda_psdev_class)) {
364 err = PTR_ERR(coda_psdev_class);
365 goto out_chrdev;
366 }
Greg Kroah-Hartman7c69ef72005-06-20 21:15:16 -0700367 for (i = 0; i < MAX_CODADEVS; i++)
Greg Kroah-Hartman53f46542005-10-27 22:25:43 -0700368 class_device_create(coda_psdev_class, NULL,
369 MKDEV(CODA_PSDEV_MAJOR,i), NULL, "cfs%d", i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 coda_sysctl_init();
371 goto out;
372
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373out_chrdev:
374 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
375out:
376 return err;
377}
378
379
380MODULE_AUTHOR("Peter J. Braam <braam@cs.cmu.edu>");
381MODULE_LICENSE("GPL");
382
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383static int __init init_coda(void)
384{
385 int status;
386 int i;
387 printk(KERN_INFO "Coda Kernel/Venus communications, "
388#ifdef CONFIG_CODA_FS_OLD_API
389 "v5.3.20"
390#else
391 "v6.0.0"
392#endif
393 ", coda@cs.cmu.edu\n");
394
395 status = coda_init_inodecache();
396 if (status)
397 goto out2;
398 status = init_coda_psdev();
399 if ( status ) {
400 printk("Problem (%d) in init_coda_psdev\n", status);
401 goto out1;
402 }
403
404 status = register_filesystem(&coda_fs_type);
405 if (status) {
406 printk("coda: failed to register filesystem!\n");
407 goto out;
408 }
409 return 0;
410out:
Greg Kroah-Hartman8ab5e4c2005-06-20 21:15:16 -0700411 for (i = 0; i < MAX_CODADEVS; i++)
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800412 class_device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800413 class_destroy(coda_psdev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
415 coda_sysctl_clean();
416out1:
417 coda_destroy_inodecache();
418out2:
419 return status;
420}
421
422static void __exit exit_coda(void)
423{
424 int err, i;
425
426 err = unregister_filesystem(&coda_fs_type);
427 if ( err != 0 ) {
428 printk("coda: failed to unregister filesystem\n");
429 }
Greg Kroah-Hartman8ab5e4c2005-06-20 21:15:16 -0700430 for (i = 0; i < MAX_CODADEVS; i++)
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800431 class_device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800432 class_destroy(coda_psdev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
434 coda_sysctl_clean();
435 coda_destroy_inodecache();
436}
437
438module_init(init_coda);
439module_exit(exit_coda);
440