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CommitLineData
1da177e4
LT
1/*
2 * An implementation of a loadable kernel mode driver providing
3 * multiple kernel/user space bidirectional communications links.
4 *
526719ba 5 * Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
1da177e4
LT
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>
174cd4b1 25#include <linux/sched/signal.h>
1da177e4
LT
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>
1da177e4
LT
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>
da47c19e 38#include <linux/mutex.h>
1da177e4 39#include <linux/device.h>
9fd973e0 40#include <linux/pid_namespace.h>
1da177e4 41#include <asm/io.h>
1da177e4 42#include <asm/poll.h>
834b46c3 43#include <linux/uaccess.h>
1da177e4
LT
44
45#include <linux/coda.h>
1da177e4 46#include <linux/coda_psdev.h>
1da177e4 47
31a203df
AV
48#include "coda_linux.h"
49
c98d8cfb 50#include "coda_int.h"
1da177e4 51
1da177e4
LT
52/* statistics */
53int coda_hard; /* allows signals during upcalls */
54unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */
55
56
57struct venus_comm coda_comms[MAX_CODADEVS];
1db560af 58static struct class *coda_psdev_class;
1da177e4
LT
59
60/*
61 * Device operations
62 */
63
64static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
65{
66 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
67 unsigned int mask = POLLOUT | POLLWRNORM;
68
69 poll_wait(file, &vcp->vc_waitq, wait);
da47c19e 70 mutex_lock(&vcp->vc_mutex);
1da177e4
LT
71 if (!list_empty(&vcp->vc_pending))
72 mask |= POLLIN | POLLRDNORM;
da47c19e 73 mutex_unlock(&vcp->vc_mutex);
1da177e4
LT
74
75 return mask;
76}
77
97718390 78static long coda_psdev_ioctl(struct file * filp, unsigned int cmd, unsigned long arg)
1da177e4
LT
79{
80 unsigned int data;
81
82 switch(cmd) {
83 case CIOC_KERNEL_VERSION:
84 data = CODA_KERNEL_VERSION;
85 return put_user(data, (int __user *) arg);
86 default:
87 return -ENOTTY;
88 }
89
90 return 0;
91}
92
93/*
94 * Receive a message written by Venus to the psdev
95 */
96
97static ssize_t coda_psdev_write(struct file *file, const char __user *buf,
98 size_t nbytes, loff_t *off)
99{
100 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
101 struct upc_req *req = NULL;
102 struct upc_req *tmp;
103 struct list_head *lh;
104 struct coda_in_hdr hdr;
105 ssize_t retval = 0, count = 0;
106 int error;
107
108 /* Peek at the opcode, uniquefier */
109 if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
110 return -EFAULT;
111
112 if (DOWNCALL(hdr.opcode)) {
f7cc02b8 113 union outputArgs *dcbuf;
1da177e4
LT
114 int size = sizeof(*dcbuf);
115
1da177e4 116 if ( nbytes < sizeof(struct coda_out_hdr) ) {
d9b4b319
FF
117 pr_warn("coda_downcall opc %d uniq %d, not enough!\n",
118 hdr.opcode, hdr.unique);
1da177e4
LT
119 count = nbytes;
120 goto out;
121 }
122 if ( nbytes > size ) {
f38cfb25 123 pr_warn("downcall opc %d, uniq %d, too much!",
d9b4b319 124 hdr.opcode, hdr.unique);
1da177e4
LT
125 nbytes = size;
126 }
127 CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
128 if (copy_from_user(dcbuf, buf, nbytes)) {
129 CODA_FREE(dcbuf, nbytes);
130 retval = -EFAULT;
131 goto out;
132 }
133
134 /* what downcall errors does Venus handle ? */
f7cc02b8 135 error = coda_downcall(vcp, hdr.opcode, dcbuf);
1da177e4
LT
136
137 CODA_FREE(dcbuf, nbytes);
138 if (error) {
6d6bd94f
FF
139 pr_warn("%s: coda_downcall error: %d\n",
140 __func__, error);
1da177e4
LT
141 retval = error;
142 goto out;
143 }
144 count = nbytes;
145 goto out;
146 }
147
148 /* Look for the message on the processing queue. */
da47c19e 149 mutex_lock(&vcp->vc_mutex);
1da177e4
LT
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) {
153 req = tmp;
154 list_del(&req->uc_chain);
155 break;
156 }
157 }
da47c19e 158 mutex_unlock(&vcp->vc_mutex);
1da177e4
LT
159
160 if (!req) {
6d6bd94f
FF
161 pr_warn("%s: msg (%d, %d) not found\n",
162 __func__, hdr.opcode, hdr.unique);
1da177e4
LT
163 retval = -ESRCH;
164 goto out;
165 }
166
167 /* move data into response buffer. */
168 if (req->uc_outSize < nbytes) {
6d6bd94f
FF
169 pr_warn("%s: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
170 __func__, req->uc_outSize, (long)nbytes,
171 hdr.opcode, hdr.unique);
1da177e4
LT
172 nbytes = req->uc_outSize; /* don't have more space! */
173 }
174 if (copy_from_user(req->uc_data, buf, nbytes)) {
4aeefdc6 175 req->uc_flags |= CODA_REQ_ABORT;
1da177e4
LT
176 wake_up(&req->uc_sleep);
177 retval = -EFAULT;
178 goto out;
179 }
180
181 /* adjust outsize. is this useful ?? */
112d421d
JH
182 req->uc_outSize = nbytes;
183 req->uc_flags |= CODA_REQ_WRITE;
1da177e4
LT
184 count = nbytes;
185
186 /* Convert filedescriptor into a file handle */
187 if (req->uc_opcode == CODA_OPEN_BY_FD) {
188 struct coda_open_by_fd_out *outp =
189 (struct coda_open_by_fd_out *)req->uc_data;
38c2e437
JH
190 if (!outp->oh.result)
191 outp->fh = fget(outp->fd);
1da177e4
LT
192 }
193
194 wake_up(&req->uc_sleep);
195out:
196 return(count ? count : retval);
197}
198
199/*
200 * Read a message from the kernel to Venus
201 */
202
203static ssize_t coda_psdev_read(struct file * file, char __user * buf,
204 size_t nbytes, loff_t *off)
205{
206 DECLARE_WAITQUEUE(wait, current);
207 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
208 struct upc_req *req;
209 ssize_t retval = 0, count = 0;
210
211 if (nbytes == 0)
212 return 0;
213
da47c19e 214 mutex_lock(&vcp->vc_mutex);
1da177e4
LT
215
216 add_wait_queue(&vcp->vc_waitq, &wait);
217 set_current_state(TASK_INTERRUPTIBLE);
218
219 while (list_empty(&vcp->vc_pending)) {
220 if (file->f_flags & O_NONBLOCK) {
221 retval = -EAGAIN;
222 break;
223 }
224 if (signal_pending(current)) {
225 retval = -ERESTARTSYS;
226 break;
227 }
da47c19e 228 mutex_unlock(&vcp->vc_mutex);
1da177e4 229 schedule();
da47c19e 230 mutex_lock(&vcp->vc_mutex);
1da177e4
LT
231 }
232
233 set_current_state(TASK_RUNNING);
234 remove_wait_queue(&vcp->vc_waitq, &wait);
235
236 if (retval)
237 goto out;
238
239 req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
240 list_del(&req->uc_chain);
241
242 /* Move the input args into userspace */
243 count = req->uc_inSize;
244 if (nbytes < req->uc_inSize) {
6d6bd94f
FF
245 pr_warn("%s: Venus read %ld bytes of %d in message\n",
246 __func__, (long)nbytes, req->uc_inSize);
1da177e4
LT
247 count = nbytes;
248 }
249
250 if (copy_to_user(buf, req->uc_data, count))
251 retval = -EFAULT;
252
253 /* If request was not a signal, enqueue and don't free */
4aeefdc6
JA
254 if (!(req->uc_flags & CODA_REQ_ASYNC)) {
255 req->uc_flags |= CODA_REQ_READ;
8e13059a 256 list_add_tail(&(req->uc_chain), &vcp->vc_processing);
1da177e4
LT
257 goto out;
258 }
259
260 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
37461e19 261 kfree(req);
1da177e4 262out:
da47c19e 263 mutex_unlock(&vcp->vc_mutex);
1da177e4
LT
264 return (count ? count : retval);
265}
266
267static int coda_psdev_open(struct inode * inode, struct file * file)
268{
87065519
JH
269 struct venus_comm *vcp;
270 int idx, err;
1da177e4 271
9fd973e0
EB
272 if (task_active_pid_ns(current) != &init_pid_ns)
273 return -EINVAL;
274
d83f5901
EB
275 if (current_user_ns() != &init_user_ns)
276 return -EINVAL;
277
1da177e4 278 idx = iminor(inode);
87065519 279 if (idx < 0 || idx >= MAX_CODADEVS)
1da177e4 280 return -ENODEV;
1da177e4 281
87065519 282 err = -EBUSY;
1da177e4 283 vcp = &coda_comms[idx];
da47c19e
YA
284 mutex_lock(&vcp->vc_mutex);
285
87065519
JH
286 if (!vcp->vc_inuse) {
287 vcp->vc_inuse++;
288
1da177e4
LT
289 INIT_LIST_HEAD(&vcp->vc_pending);
290 INIT_LIST_HEAD(&vcp->vc_processing);
291 init_waitqueue_head(&vcp->vc_waitq);
292 vcp->vc_sb = NULL;
293 vcp->vc_seq = 0;
87065519
JH
294
295 file->private_data = vcp;
296 err = 0;
1da177e4 297 }
1da177e4 298
da47c19e 299 mutex_unlock(&vcp->vc_mutex);
87065519 300 return err;
1da177e4
LT
301}
302
303
304static int coda_psdev_release(struct inode * inode, struct file * file)
305{
87065519
JH
306 struct venus_comm *vcp = (struct venus_comm *) file->private_data;
307 struct upc_req *req, *tmp;
1da177e4 308
87065519 309 if (!vcp || !vcp->vc_inuse ) {
6d6bd94f 310 pr_warn("%s: Not open.\n", __func__);
1da177e4
LT
311 return -1;
312 }
313
da47c19e 314 mutex_lock(&vcp->vc_mutex);
87065519
JH
315
316 /* Wakeup clients so they can return. */
1da177e4 317 list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
87065519
JH
318 list_del(&req->uc_chain);
319
1da177e4 320 /* Async requests need to be freed here */
4aeefdc6 321 if (req->uc_flags & CODA_REQ_ASYNC) {
1da177e4 322 CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
37461e19 323 kfree(req);
1da177e4
LT
324 continue;
325 }
4aeefdc6 326 req->uc_flags |= CODA_REQ_ABORT;
1da177e4 327 wake_up(&req->uc_sleep);
87065519
JH
328 }
329
330 list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
331 list_del(&req->uc_chain);
332
4aeefdc6 333 req->uc_flags |= CODA_REQ_ABORT;
87065519
JH
334 wake_up(&req->uc_sleep);
335 }
1da177e4 336
87065519
JH
337 file->private_data = NULL;
338 vcp->vc_inuse--;
da47c19e 339 mutex_unlock(&vcp->vc_mutex);
1da177e4
LT
340 return 0;
341}
342
343
4b6f5d20 344static const struct file_operations coda_psdev_fops = {
1da177e4
LT
345 .owner = THIS_MODULE,
346 .read = coda_psdev_read,
347 .write = coda_psdev_write,
348 .poll = coda_psdev_poll,
97718390 349 .unlocked_ioctl = coda_psdev_ioctl,
1da177e4
LT
350 .open = coda_psdev_open,
351 .release = coda_psdev_release,
6038f373 352 .llseek = noop_llseek,
1da177e4
LT
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)) {
6d6bd94f
FF
359 pr_err("%s: unable to get major %d\n",
360 __func__, CODA_PSDEV_MAJOR);
1da177e4
LT
361 return -EIO;
362 }
1db560af 363 coda_psdev_class = class_create(THIS_MODULE, "coda");
1da177e4
LT
364 if (IS_ERR(coda_psdev_class)) {
365 err = PTR_ERR(coda_psdev_class);
366 goto out_chrdev;
367 }
da47c19e
YA
368 for (i = 0; i < MAX_CODADEVS; i++) {
369 mutex_init(&(&coda_comms[i])->vc_mutex);
a9b12619
GKH
370 device_create(coda_psdev_class, NULL,
371 MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i);
da47c19e 372 }
1da177e4
LT
373 coda_sysctl_init();
374 goto out;
375
1da177e4
LT
376out_chrdev:
377 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
378out:
379 return err;
380}
381
5b7f13bd
JH
382MODULE_AUTHOR("Jan Harkes, Peter J. Braam");
383MODULE_DESCRIPTION("Coda Distributed File System VFS interface");
384MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR);
1da177e4 385MODULE_LICENSE("GPL");
5b7f13bd 386MODULE_VERSION("6.6");
1da177e4 387
1da177e4
LT
388static int __init init_coda(void)
389{
390 int status;
391 int i;
1da177e4
LT
392
393 status = coda_init_inodecache();
394 if (status)
395 goto out2;
396 status = init_coda_psdev();
397 if ( status ) {
d9b4b319 398 pr_warn("Problem (%d) in init_coda_psdev\n", status);
1da177e4
LT
399 goto out1;
400 }
401
402 status = register_filesystem(&coda_fs_type);
403 if (status) {
f38cfb25 404 pr_warn("failed to register filesystem!\n");
1da177e4
LT
405 goto out;
406 }
407 return 0;
408out:
8ab5e4c1 409 for (i = 0; i < MAX_CODADEVS; i++)
62ca8792 410 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
1db560af 411 class_destroy(coda_psdev_class);
1da177e4
LT
412 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
413 coda_sysctl_clean();
414out1:
415 coda_destroy_inodecache();
416out2:
417 return status;
418}
419
420static void __exit exit_coda(void)
421{
422 int err, i;
423
424 err = unregister_filesystem(&coda_fs_type);
d9b4b319 425 if (err != 0)
f38cfb25 426 pr_warn("failed to unregister filesystem\n");
8ab5e4c1 427 for (i = 0; i < MAX_CODADEVS; i++)
62ca8792 428 device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
1db560af 429 class_destroy(coda_psdev_class);
1da177e4
LT
430 unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
431 coda_sysctl_clean();
432 coda_destroy_inodecache();
433}
434
435module_init(init_coda);
436module_exit(exit_coda);
437