blob: f478222cb5c93b73b7b2b846574df3cb0617d061 [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>
31#include <linux/devfs_fs_kernel.h>
32#include <linux/vmalloc.h>
33#include <linux/fs.h>
34#include <linux/file.h>
35#include <linux/poll.h>
36#include <linux/init.h>
37#include <linux/list.h>
38#include <linux/smp_lock.h>
39#include <linux/device.h>
40#include <asm/io.h>
41#include <asm/system.h>
42#include <asm/poll.h>
43#include <asm/uaccess.h>
44
45#include <linux/coda.h>
46#include <linux/coda_linux.h>
47#include <linux/coda_fs_i.h>
48#include <linux/coda_psdev.h>
49#include <linux/coda_proc.h>
50
Adrian Bunkc98d8cf2006-03-24 03:15:53 -080051#include "coda_int.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
Adrian Bunkc98d8cf2006-03-24 03:15:53 -080053#define upc_free(r) kfree(r)
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55/* statistics */
56int coda_hard; /* allows signals during upcalls */
57unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
58
59
60struct venus_comm coda_comms[MAX_CODADEVS];
gregkh@suse.de1db560a2005-03-23 10:02:26 -080061static struct class *coda_psdev_class;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63/*
64 * Device operations
65 */
66
67static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
68{
69 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
70 unsigned int mask = POLLOUT | POLLWRNORM;
71
72 poll_wait(file, &vcp->vc_waitq, wait);
73 if (!list_empty(&vcp->vc_pending))
74 mask |= POLLIN | POLLRDNORM;
75
76 return mask;
77}
78
79static int coda_psdev_ioctl(struct inode * inode, struct file * filp,
80 unsigned int cmd, unsigned long arg)
81{
82 unsigned int data;
83
84 switch(cmd) {
85 case CIOC_KERNEL_VERSION:
86 data = CODA_KERNEL_VERSION;
87 return put_user(data, (int __user *) arg);
88 default:
89 return -ENOTTY;
90 }
91
92 return 0;
93}
94
95/*
96 * Receive a message written by Venus to the psdev
97 */
98
99static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
100 size_t nbytes, loff_t *off)
101{
102 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
103 struct upc_req *req = NULL;
104 struct upc_req *tmp;
105 struct list_head *lh;
106 struct coda_in_hdr hdr;
107 ssize_t retval = 0, count = 0;
108 int error;
109
110 /* Peek at the opcode, uniquefier */
111 if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
112 return -EFAULT;
113
114 if (DOWNCALL(hdr.opcode)) {
115 struct super_block *sb = NULL;
116 union outputArgs *dcbuf;
117 int size = sizeof(*dcbuf);
118
119 sb = vcp->vc_sb;
120 if ( !sb ) {
121 count = nbytes;
122 goto out;
123 }
124
125 if ( nbytes < sizeof(struct coda_out_hdr) ) {
126 printk("coda_downcall opc %d uniq %d, not enough!\n",
127 hdr.opcode, hdr.unique);
128 count = nbytes;
129 goto out;
130 }
131 if ( nbytes > size ) {
132 printk("Coda: downcall opc %d, uniq %d, too much!",
133 hdr.opcode, hdr.unique);
134 nbytes = size;
135 }
136 CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
137 if (copy_from_user(dcbuf, buf, nbytes)) {
138 CODA_FREE(dcbuf, nbytes);
139 retval = -EFAULT;
140 goto out;
141 }
142
143 /* what downcall errors does Venus handle ? */
144 lock_kernel();
145 error = coda_downcall(hdr.opcode, dcbuf, sb);
146 unlock_kernel();
147
148 CODA_FREE(dcbuf, nbytes);
149 if (error) {
150 printk("psdev_write: coda_downcall error: %d\n", error);
151 retval = error;
152 goto out;
153 }
154 count = nbytes;
155 goto out;
156 }
157
158 /* Look for the message on the processing queue. */
159 lock_kernel();
160 list_for_each(lh, &vcp->vc_processing) {
161 tmp = list_entry(lh, struct upc_req , uc_chain);
162 if (tmp->uc_unique == hdr.unique) {
163 req = tmp;
164 list_del(&req->uc_chain);
165 break;
166 }
167 }
168 unlock_kernel();
169
170 if (!req) {
171 printk("psdev_write: msg (%d, %d) not found\n",
172 hdr.opcode, hdr.unique);
173 retval = -ESRCH;
174 goto out;
175 }
176
177 /* move data into response buffer. */
178 if (req->uc_outSize < nbytes) {
179 printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
180 req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique);
181 nbytes = req->uc_outSize; /* don't have more space! */
182 }
183 if (copy_from_user(req->uc_data, buf, nbytes)) {
184 req->uc_flags |= REQ_ABORT;
185 wake_up(&req->uc_sleep);
186 retval = -EFAULT;
187 goto out;
188 }
189
190 /* adjust outsize. is this useful ?? */
191 req->uc_outSize = nbytes;
192 req->uc_flags |= REQ_WRITE;
193 count = nbytes;
194
195 /* Convert filedescriptor into a file handle */
196 if (req->uc_opcode == CODA_OPEN_BY_FD) {
197 struct coda_open_by_fd_out *outp =
198 (struct coda_open_by_fd_out *)req->uc_data;
199 outp->fh = fget(outp->fd);
200 }
201
202 wake_up(&req->uc_sleep);
203out:
204 return(count ? count : retval);
205}
206
207/*
208 * Read a message from the kernel to Venus
209 */
210
211static ssize_t coda_psdev_read(struct file * file, char __user * buf,
212 size_t nbytes, loff_t *off)
213{
214 DECLARE_WAITQUEUE(wait, current);
215 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
216 struct upc_req *req;
217 ssize_t retval = 0, count = 0;
218
219 if (nbytes == 0)
220 return 0;
221
222 lock_kernel();
223
224 add_wait_queue(&vcp->vc_waitq, &wait);
225 set_current_state(TASK_INTERRUPTIBLE);
226
227 while (list_empty(&vcp->vc_pending)) {
228 if (file->f_flags & O_NONBLOCK) {
229 retval = -EAGAIN;
230 break;
231 }
232 if (signal_pending(current)) {
233 retval = -ERESTARTSYS;
234 break;
235 }
236 schedule();
237 }
238
239 set_current_state(TASK_RUNNING);
240 remove_wait_queue(&vcp->vc_waitq, &wait);
241
242 if (retval)
243 goto out;
244
245 req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
246 list_del(&req->uc_chain);
247
248 /* Move the input args into userspace */
249 count = req->uc_inSize;
250 if (nbytes < req->uc_inSize) {
251 printk ("psdev_read: Venus read %ld bytes of %d in message\n",
252 (long)nbytes, req->uc_inSize);
253 count = nbytes;
254 }
255
256 if (copy_to_user(buf, req->uc_data, count))
257 retval = -EFAULT;
258
259 /* If request was not a signal, enqueue and don't free */
260 if (!(req->uc_flags & REQ_ASYNC)) {
261 req->uc_flags |= REQ_READ;
Akinobu Mita8e130592006-06-26 00:24:37 -0700262 list_add_tail(&(req->uc_chain), &vcp->vc_processing);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 goto out;
264 }
265
266 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
267 upc_free(req);
268out:
269 unlock_kernel();
270 return (count ? count : retval);
271}
272
273static int coda_psdev_open(struct inode * inode, struct file * file)
274{
275 struct venus_comm *vcp;
276 int idx;
277
278 lock_kernel();
279 idx = iminor(inode);
280 if(idx >= MAX_CODADEVS) {
281 unlock_kernel();
282 return -ENODEV;
283 }
284
285 vcp = &coda_comms[idx];
286 if(vcp->vc_inuse) {
287 unlock_kernel();
288 return -EBUSY;
289 }
290
291 if (!vcp->vc_inuse++) {
292 INIT_LIST_HEAD(&vcp->vc_pending);
293 INIT_LIST_HEAD(&vcp->vc_processing);
294 init_waitqueue_head(&vcp->vc_waitq);
295 vcp->vc_sb = NULL;
296 vcp->vc_seq = 0;
297 }
298
299 file->private_data = vcp;
300
301 unlock_kernel();
302 return 0;
303}
304
305
306static int coda_psdev_release(struct inode * inode, struct file * file)
307{
308 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
309 struct upc_req *req, *tmp;
310
311 lock_kernel();
312 if ( !vcp->vc_inuse ) {
313 unlock_kernel();
314 printk("psdev_release: Not open.\n");
315 return -1;
316 }
317
318 if (--vcp->vc_inuse) {
319 unlock_kernel();
320 return 0;
321 }
322
323 /* Wakeup clients so they can return. */
324 list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
325 /* Async requests need to be freed here */
326 if (req->uc_flags & REQ_ASYNC) {
327 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
328 upc_free(req);
329 continue;
330 }
331 req->uc_flags |= REQ_ABORT;
332 wake_up(&req->uc_sleep);
333 }
334
335 list_for_each_entry(req, &vcp->vc_processing, uc_chain) {
336 req->uc_flags |= REQ_ABORT;
337 wake_up(&req->uc_sleep);
338 }
339
340 unlock_kernel();
341 return 0;
342}
343
344
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800345static const struct file_operations coda_psdev_fops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 .owner = THIS_MODULE,
347 .read = coda_psdev_read,
348 .write = coda_psdev_write,
349 .poll = coda_psdev_poll,
350 .ioctl = coda_psdev_ioctl,
351 .open = coda_psdev_open,
352 .release = coda_psdev_release,
353};
354
355static int init_coda_psdev(void)
356{
357 int i, err = 0;
358 if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
359 printk(KERN_ERR "coda_psdev: unable to get major %d\n",
360 CODA_PSDEV_MAJOR);
361 return -EIO;
362 }
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800363 coda_psdev_class = class_create(THIS_MODULE, "coda");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 if (IS_ERR(coda_psdev_class)) {
365 err = PTR_ERR(coda_psdev_class);
366 goto out_chrdev;
367 }
Greg Kroah-Hartman7c69ef72005-06-20 21:15:16 -0700368 for (i = 0; i < MAX_CODADEVS; i++)
Greg Kroah-Hartman53f46542005-10-27 22:25:43 -0700369 class_device_create(coda_psdev_class, NULL,
370 MKDEV(CODA_PSDEV_MAJOR,i), NULL, "cfs%d", i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 coda_sysctl_init();
372 goto out;
373
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374out_chrdev:
375 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
376out:
377 return err;
378}
379
380
381MODULE_AUTHOR("Peter J. Braam <braam@cs.cmu.edu>");
382MODULE_LICENSE("GPL");
383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384static int __init init_coda(void)
385{
386 int status;
387 int i;
388 printk(KERN_INFO "Coda Kernel/Venus communications, "
389#ifdef CONFIG_CODA_FS_OLD_API
390 "v5.3.20"
391#else
392 "v6.0.0"
393#endif
394 ", coda@cs.cmu.edu\n");
395
396 status = coda_init_inodecache();
397 if (status)
398 goto out2;
399 status = init_coda_psdev();
400 if ( status ) {
401 printk("Problem (%d) in init_coda_psdev\n", status);
402 goto out1;
403 }
404
405 status = register_filesystem(&coda_fs_type);
406 if (status) {
407 printk("coda: failed to register filesystem!\n");
408 goto out;
409 }
410 return 0;
411out:
412 for (i = 0; i < MAX_CODADEVS; i++) {
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800413 class_device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 devfs_remove("coda/%d", i);
415 }
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800416 class_destroy(coda_psdev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 devfs_remove("coda");
418 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
419 coda_sysctl_clean();
420out1:
421 coda_destroy_inodecache();
422out2:
423 return status;
424}
425
426static void __exit exit_coda(void)
427{
428 int err, i;
429
430 err = unregister_filesystem(&coda_fs_type);
431 if ( err != 0 ) {
432 printk("coda: failed to unregister filesystem\n");
433 }
434 for (i = 0; i < MAX_CODADEVS; i++) {
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800435 class_device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 devfs_remove("coda/%d", i);
437 }
gregkh@suse.de1db560a2005-03-23 10:02:26 -0800438 class_destroy(coda_psdev_class);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 devfs_remove("coda");
440 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
441 coda_sysctl_clean();
442 coda_destroy_inodecache();
443}
444
445module_init(init_coda);
446module_exit(exit_coda);
447