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-rw-r--r--fs/coda/psdev.c462
1 files changed, 462 insertions, 0 deletions
diff --git a/fs/coda/psdev.c b/fs/coda/psdev.c
new file mode 100644
index 000000000000..ef001a9313e6
--- /dev/null
+++ b/fs/coda/psdev.c
@@ -0,0 +1,462 @@
1/*
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
51#define upc_free(r) kfree(r)
52
53/*
54 * Coda stuff
55 */
56extern struct file_system_type coda_fs_type;
57
58/* statistics */
59int coda_hard; /* allows signals during upcalls */
60unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
61
62
63struct venus_comm coda_comms[MAX_CODADEVS];
64static struct class_simple *coda_psdev_class;
65
66/*
67 * Device operations
68 */
69
70static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
71{
72 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
73 unsigned int mask = POLLOUT | POLLWRNORM;
74
75 poll_wait(file, &vcp->vc_waitq, wait);
76 if (!list_empty(&vcp->vc_pending))
77 mask |= POLLIN | POLLRDNORM;
78
79 return mask;
80}
81
82static int coda_psdev_ioctl(struct inode * inode, struct file * filp,
83 unsigned int cmd, unsigned long arg)
84{
85 unsigned int data;
86
87 switch(cmd) {
88 case CIOC_KERNEL_VERSION:
89 data = CODA_KERNEL_VERSION;
90 return put_user(data, (int __user *) arg);
91 default:
92 return -ENOTTY;
93 }
94
95 return 0;
96}
97
98/*
99 * Receive a message written by Venus to the psdev
100 */
101
102static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
103 size_t nbytes, loff_t *off)
104{
105 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
106 struct upc_req *req = NULL;
107 struct upc_req *tmp;
108 struct list_head *lh;
109 struct coda_in_hdr hdr;
110 ssize_t retval = 0, count = 0;
111 int error;
112
113 /* Peek at the opcode, uniquefier */
114 if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
115 return -EFAULT;
116
117 if (DOWNCALL(hdr.opcode)) {
118 struct super_block *sb = NULL;
119 union outputArgs *dcbuf;
120 int size = sizeof(*dcbuf);
121
122 sb = vcp->vc_sb;
123 if ( !sb ) {
124 count = nbytes;
125 goto out;
126 }
127
128 if ( nbytes < sizeof(struct coda_out_hdr) ) {
129 printk("coda_downcall opc %d uniq %d, not enough!\n",
130 hdr.opcode, hdr.unique);
131 count = nbytes;
132 goto out;
133 }
134 if ( nbytes > size ) {
135 printk("Coda: downcall opc %d, uniq %d, too much!",
136 hdr.opcode, hdr.unique);
137 nbytes = size;
138 }
139 CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
140 if (copy_from_user(dcbuf, buf, nbytes)) {
141 CODA_FREE(dcbuf, nbytes);
142 retval = -EFAULT;
143 goto out;
144 }
145
146 /* what downcall errors does Venus handle ? */
147 lock_kernel();
148 error = coda_downcall(hdr.opcode, dcbuf, sb);
149 unlock_kernel();
150
151 CODA_FREE(dcbuf, nbytes);
152 if (error) {
153 printk("psdev_write: coda_downcall error: %d\n", error);
154 retval = error;
155 goto out;
156 }
157 count = nbytes;
158 goto out;
159 }
160
161 /* Look for the message on the processing queue. */
162 lock_kernel();
163 list_for_each(lh, &vcp->vc_processing) {
164 tmp = list_entry(lh, struct upc_req , uc_chain);
165 if (tmp->uc_unique == hdr.unique) {
166 req = tmp;
167 list_del(&req->uc_chain);
168 break;
169 }
170 }
171 unlock_kernel();
172
173 if (!req) {
174 printk("psdev_write: msg (%d, %d) not found\n",
175 hdr.opcode, hdr.unique);
176 retval = -ESRCH;
177 goto out;
178 }
179
180 /* move data into response buffer. */
181 if (req->uc_outSize < nbytes) {
182 printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
183 req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique);
184 nbytes = req->uc_outSize; /* don't have more space! */
185 }
186 if (copy_from_user(req->uc_data, buf, nbytes)) {
187 req->uc_flags |= REQ_ABORT;
188 wake_up(&req->uc_sleep);
189 retval = -EFAULT;
190 goto out;
191 }
192
193 /* adjust outsize. is this useful ?? */
194 req->uc_outSize = nbytes;
195 req->uc_flags |= REQ_WRITE;
196 count = nbytes;
197
198 /* Convert filedescriptor into a file handle */
199 if (req->uc_opcode == CODA_OPEN_BY_FD) {
200 struct coda_open_by_fd_out *outp =
201 (struct coda_open_by_fd_out *)req->uc_data;
202 outp->fh = fget(outp->fd);
203 }
204
205 wake_up(&req->uc_sleep);
206out:
207 return(count ? count : retval);
208}
209
210/*
211 * Read a message from the kernel to Venus
212 */
213
214static ssize_t coda_psdev_read(struct file * file, char __user * buf,
215 size_t nbytes, loff_t *off)
216{
217 DECLARE_WAITQUEUE(wait, current);
218 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
219 struct upc_req *req;
220 ssize_t retval = 0, count = 0;
221
222 if (nbytes == 0)
223 return 0;
224
225 lock_kernel();
226
227 add_wait_queue(&vcp->vc_waitq, &wait);
228 set_current_state(TASK_INTERRUPTIBLE);
229
230 while (list_empty(&vcp->vc_pending)) {
231 if (file->f_flags & O_NONBLOCK) {
232 retval = -EAGAIN;
233 break;
234 }
235 if (signal_pending(current)) {
236 retval = -ERESTARTSYS;
237 break;
238 }
239 schedule();
240 }
241
242 set_current_state(TASK_RUNNING);
243 remove_wait_queue(&vcp->vc_waitq, &wait);
244
245 if (retval)
246 goto out;
247
248 req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
249 list_del(&req->uc_chain);
250
251 /* Move the input args into userspace */
252 count = req->uc_inSize;
253 if (nbytes < req->uc_inSize) {
254 printk ("psdev_read: Venus read %ld bytes of %d in message\n",
255 (long)nbytes, req->uc_inSize);
256 count = nbytes;
257 }
258
259 if (copy_to_user(buf, req->uc_data, count))
260 retval = -EFAULT;
261
262 /* If request was not a signal, enqueue and don't free */
263 if (!(req->uc_flags & REQ_ASYNC)) {
264 req->uc_flags |= REQ_READ;
265 list_add(&(req->uc_chain), vcp->vc_processing.prev);
266 goto out;
267 }
268
269 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
270 upc_free(req);
271out:
272 unlock_kernel();
273 return (count ? count : retval);
274}
275
276static int coda_psdev_open(struct inode * inode, struct file * file)
277{
278 struct venus_comm *vcp;
279 int idx;
280
281 lock_kernel();
282 idx = iminor(inode);
283 if(idx >= MAX_CODADEVS) {
284 unlock_kernel();
285 return -ENODEV;
286 }
287
288 vcp = &coda_comms[idx];
289 if(vcp->vc_inuse) {
290 unlock_kernel();
291 return -EBUSY;
292 }
293
294 if (!vcp->vc_inuse++) {
295 INIT_LIST_HEAD(&vcp->vc_pending);
296 INIT_LIST_HEAD(&vcp->vc_processing);
297 init_waitqueue_head(&vcp->vc_waitq);
298 vcp->vc_sb = NULL;
299 vcp->vc_seq = 0;
300 }
301
302 file->private_data = vcp;
303
304 unlock_kernel();
305 return 0;
306}
307
308
309static int coda_psdev_release(struct inode * inode, struct file * file)
310{
311 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
312 struct upc_req *req, *tmp;
313
314 lock_kernel();
315 if ( !vcp->vc_inuse ) {
316 unlock_kernel();
317 printk("psdev_release: Not open.\n");
318 return -1;
319 }
320
321 if (--vcp->vc_inuse) {
322 unlock_kernel();
323 return 0;
324 }
325
326 /* Wakeup clients so they can return. */
327 list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
328 /* Async requests need to be freed here */
329 if (req->uc_flags & REQ_ASYNC) {
330 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
331 upc_free(req);
332 continue;
333 }
334 req->uc_flags |= REQ_ABORT;
335 wake_up(&req->uc_sleep);
336 }
337
338 list_for_each_entry(req, &vcp->vc_processing, uc_chain) {
339 req->uc_flags |= REQ_ABORT;
340 wake_up(&req->uc_sleep);
341 }
342
343 unlock_kernel();
344 return 0;
345}
346
347
348static struct file_operations coda_psdev_fops = {
349 .owner = THIS_MODULE,
350 .read = coda_psdev_read,
351 .write = coda_psdev_write,
352 .poll = coda_psdev_poll,
353 .ioctl = coda_psdev_ioctl,
354 .open = coda_psdev_open,
355 .release = coda_psdev_release,
356};
357
358static int init_coda_psdev(void)
359{
360 int i, err = 0;
361 if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
362 printk(KERN_ERR "coda_psdev: unable to get major %d\n",
363 CODA_PSDEV_MAJOR);
364 return -EIO;
365 }
366 coda_psdev_class = class_simple_create(THIS_MODULE, "coda");
367 if (IS_ERR(coda_psdev_class)) {
368 err = PTR_ERR(coda_psdev_class);
369 goto out_chrdev;
370 }
371 devfs_mk_dir ("coda");
372 for (i = 0; i < MAX_CODADEVS; i++) {
373 class_simple_device_add(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR,i),
374 NULL, "cfs%d", i);
375 err = devfs_mk_cdev(MKDEV(CODA_PSDEV_MAJOR, i),
376 S_IFCHR|S_IRUSR|S_IWUSR, "coda/%d", i);
377 if (err)
378 goto out_class;
379 }
380 coda_sysctl_init();
381 goto out;
382
383out_class:
384 for (i = 0; i < MAX_CODADEVS; i++)
385 class_simple_device_remove(MKDEV(CODA_PSDEV_MAJOR, i));
386 class_simple_destroy(coda_psdev_class);
387out_chrdev:
388 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
389out:
390 return err;
391}
392
393
394MODULE_AUTHOR("Peter J. Braam <braam@cs.cmu.edu>");
395MODULE_LICENSE("GPL");
396
397extern int coda_init_inodecache(void);
398extern void coda_destroy_inodecache(void);
399static int __init init_coda(void)
400{
401 int status;
402 int i;
403 printk(KERN_INFO "Coda Kernel/Venus communications, "
404#ifdef CONFIG_CODA_FS_OLD_API
405 "v5.3.20"
406#else
407 "v6.0.0"
408#endif
409 ", coda@cs.cmu.edu\n");
410
411 status = coda_init_inodecache();
412 if (status)
413 goto out2;
414 status = init_coda_psdev();
415 if ( status ) {
416 printk("Problem (%d) in init_coda_psdev\n", status);
417 goto out1;
418 }
419
420 status = register_filesystem(&coda_fs_type);
421 if (status) {
422 printk("coda: failed to register filesystem!\n");
423 goto out;
424 }
425 return 0;
426out:
427 for (i = 0; i < MAX_CODADEVS; i++) {
428 class_simple_device_remove(MKDEV(CODA_PSDEV_MAJOR, i));
429 devfs_remove("coda/%d", i);
430 }
431 class_simple_destroy(coda_psdev_class);
432 devfs_remove("coda");
433 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
434 coda_sysctl_clean();
435out1:
436 coda_destroy_inodecache();
437out2:
438 return status;
439}
440
441static void __exit exit_coda(void)
442{
443 int err, i;
444
445 err = unregister_filesystem(&coda_fs_type);
446 if ( err != 0 ) {
447 printk("coda: failed to unregister filesystem\n");
448 }
449 for (i = 0; i < MAX_CODADEVS; i++) {
450 class_simple_device_remove(MKDEV(CODA_PSDEV_MAJOR, i));
451 devfs_remove("coda/%d", i);
452 }
453 class_simple_destroy(coda_psdev_class);
454 devfs_remove("coda");
455 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
456 coda_sysctl_clean();
457 coda_destroy_inodecache();
458}
459
460module_init(init_coda);
461module_exit(exit_coda);
462
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