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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@lxorguk.ukuu.org.uk> |
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/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 | |
49 | #include "coda_int.h" |
50 | |
51 | /* statistics */ |
52 | int coda_hard; /* allows signals during upcalls */ |
53 | unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */ |
54 | |
55 | |
56 | struct venus_comm coda_comms[MAX_CODADEVS]; |
57 | static struct class *coda_psdev_class; |
58 | |
59 | /* |
60 | * Device operations |
61 | */ |
62 | |
63 | static unsigned int coda_psdev_poll(struct file *file, poll_table * wait) |
64 | { |
65 | struct venus_comm *vcp = (struct venus_comm *) file->private_data; |
66 | unsigned int mask = POLLOUT | POLLWRNORM; |
67 | |
68 | poll_wait(file, &vcp->vc_waitq, wait); |
69 | if (!list_empty(&vcp->vc_pending)) |
70 | mask |= POLLIN | POLLRDNORM; |
71 | |
72 | return mask; |
73 | } |
74 | |
75 | static int coda_psdev_ioctl(struct inode * inode, struct file * filp, |
76 | unsigned int cmd, unsigned long arg) |
77 | { |
78 | unsigned int data; |
79 | |
80 | switch(cmd) { |
81 | case CIOC_KERNEL_VERSION: |
82 | data = CODA_KERNEL_VERSION; |
83 | return put_user(data, (int __user *) arg); |
84 | default: |
85 | return -ENOTTY; |
86 | } |
87 | |
88 | return 0; |
89 | } |
90 | |
91 | /* |
92 | * Receive a message written by Venus to the psdev |
93 | */ |
94 | |
95 | static ssize_t coda_psdev_write(struct file *file, const char __user *buf, |
96 | size_t nbytes, loff_t *off) |
97 | { |
98 | struct venus_comm *vcp = (struct venus_comm *) file->private_data; |
99 | struct upc_req *req = NULL; |
100 | struct upc_req *tmp; |
101 | struct list_head *lh; |
102 | struct coda_in_hdr hdr; |
103 | ssize_t retval = 0, count = 0; |
104 | int error; |
105 | |
106 | /* Peek at the opcode, uniquefier */ |
107 | if (copy_from_user(&hdr, buf, 2 * sizeof(u_long))) |
108 | return -EFAULT; |
109 | |
110 | if (DOWNCALL(hdr.opcode)) { |
111 | struct super_block *sb = NULL; |
112 | union outputArgs *dcbuf; |
113 | int size = sizeof(*dcbuf); |
114 | |
115 | sb = vcp->vc_sb; |
116 | if ( !sb ) { |
117 | count = nbytes; |
118 | goto out; |
119 | } |
120 | |
121 | if ( nbytes < sizeof(struct coda_out_hdr) ) { |
122 | printk("coda_downcall opc %d uniq %d, not enough!\n", |
123 | hdr.opcode, hdr.unique); |
124 | count = nbytes; |
125 | goto out; |
126 | } |
127 | if ( nbytes > size ) { |
128 | printk("Coda: downcall opc %d, uniq %d, too much!", |
129 | hdr.opcode, hdr.unique); |
130 | nbytes = size; |
131 | } |
132 | CODA_ALLOC(dcbuf, union outputArgs *, nbytes); |
133 | if (copy_from_user(dcbuf, buf, nbytes)) { |
134 | CODA_FREE(dcbuf, nbytes); |
135 | retval = -EFAULT; |
136 | goto out; |
137 | } |
138 | |
139 | /* what downcall errors does Venus handle ? */ |
140 | lock_kernel(); |
141 | error = coda_downcall(hdr.opcode, dcbuf, sb); |
142 | unlock_kernel(); |
143 | |
144 | CODA_FREE(dcbuf, nbytes); |
145 | if (error) { |
146 | printk("psdev_write: coda_downcall error: %d\n", error); |
147 | retval = error; |
148 | goto out; |
149 | } |
150 | count = nbytes; |
151 | goto out; |
152 | } |
153 | |
154 | /* Look for the message on the processing queue. */ |
155 | lock_kernel(); |
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) { |
159 | req = tmp; |
160 | list_del(&req->uc_chain); |
161 | break; |
162 | } |
163 | } |
164 | unlock_kernel(); |
165 | |
166 | if (!req) { |
167 | printk("psdev_write: msg (%d, %d) not found\n", |
168 | hdr.opcode, hdr.unique); |
169 | retval = -ESRCH; |
170 | goto out; |
171 | } |
172 | |
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! */ |
178 | } |
179 | if (copy_from_user(req->uc_data, buf, nbytes)) { |
180 | req->uc_flags |= REQ_ABORT; |
181 | wake_up(&req->uc_sleep); |
182 | retval = -EFAULT; |
183 | goto out; |
184 | } |
185 | |
186 | /* adjust outsize. is this useful ?? */ |
187 | req->uc_outSize = nbytes; |
188 | req->uc_flags |= REQ_WRITE; |
189 | count = nbytes; |
190 | |
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); |
197 | } |
198 | |
199 | wake_up(&req->uc_sleep); |
200 | out: |
201 | return(count ? count : retval); |
202 | } |
203 | |
204 | /* |
205 | * Read a message from the kernel to Venus |
206 | */ |
207 | |
208 | static ssize_t coda_psdev_read(struct file * file, char __user * buf, |
209 | size_t nbytes, loff_t *off) |
210 | { |
211 | DECLARE_WAITQUEUE(wait, current); |
212 | struct venus_comm *vcp = (struct venus_comm *) file->private_data; |
213 | struct upc_req *req; |
214 | ssize_t retval = 0, count = 0; |
215 | |
216 | if (nbytes == 0) |
217 | return 0; |
218 | |
219 | lock_kernel(); |
220 | |
221 | add_wait_queue(&vcp->vc_waitq, &wait); |
222 | set_current_state(TASK_INTERRUPTIBLE); |
223 | |
224 | while (list_empty(&vcp->vc_pending)) { |
225 | if (file->f_flags & O_NONBLOCK) { |
226 | retval = -EAGAIN; |
227 | break; |
228 | } |
229 | if (signal_pending(current)) { |
230 | retval = -ERESTARTSYS; |
231 | break; |
232 | } |
233 | schedule(); |
234 | } |
235 | |
236 | set_current_state(TASK_RUNNING); |
237 | remove_wait_queue(&vcp->vc_waitq, &wait); |
238 | |
239 | if (retval) |
240 | goto out; |
241 | |
242 | req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain); |
243 | list_del(&req->uc_chain); |
244 | |
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); |
250 | count = nbytes; |
251 | } |
252 | |
253 | if (copy_to_user(buf, req->uc_data, count)) |
254 | retval = -EFAULT; |
255 | |
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); |
260 | goto out; |
261 | } |
262 | |
263 | CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr)); |
264 | kfree(req); |
265 | out: |
266 | unlock_kernel(); |
267 | return (count ? count : retval); |
268 | } |
269 | |
270 | static int coda_psdev_open(struct inode * inode, struct file * file) |
271 | { |
272 | struct venus_comm *vcp; |
273 | int idx, err; |
274 | |
275 | idx = iminor(inode); |
276 | if (idx < 0 || idx >= MAX_CODADEVS) |
277 | return -ENODEV; |
278 | |
279 | lock_kernel(); |
280 | |
281 | err = -EBUSY; |
282 | vcp = &coda_comms[idx]; |
283 | if (!vcp->vc_inuse) { |
284 | vcp->vc_inuse++; |
285 | |
286 | INIT_LIST_HEAD(&vcp->vc_pending); |
287 | INIT_LIST_HEAD(&vcp->vc_processing); |
288 | init_waitqueue_head(&vcp->vc_waitq); |
289 | vcp->vc_sb = NULL; |
290 | vcp->vc_seq = 0; |
291 | |
292 | file->private_data = vcp; |
293 | err = 0; |
294 | } |
295 | |
296 | unlock_kernel(); |
297 | return err; |
298 | } |
299 | |
300 | |
301 | static int coda_psdev_release(struct inode * inode, struct file * file) |
302 | { |
303 | struct venus_comm *vcp = (struct venus_comm *) file->private_data; |
304 | struct upc_req *req, *tmp; |
305 | |
306 | if (!vcp || !vcp->vc_inuse ) { |
307 | printk("psdev_release: Not open.\n"); |
308 | return -1; |
309 | } |
310 | |
311 | lock_kernel(); |
312 | |
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); |
316 | |
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)); |
320 | kfree(req); |
321 | continue; |
322 | } |
323 | req->uc_flags |= REQ_ABORT; |
324 | wake_up(&req->uc_sleep); |
325 | } |
326 | |
327 | list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) { |
328 | list_del(&req->uc_chain); |
329 | |
330 | req->uc_flags |= REQ_ABORT; |
331 | wake_up(&req->uc_sleep); |
332 | } |
333 | |
334 | file->private_data = NULL; |
335 | vcp->vc_inuse--; |
336 | unlock_kernel(); |
337 | return 0; |
338 | } |
339 | |
340 | |
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, |
349 | }; |
350 | |
351 | static int init_coda_psdev(void) |
352 | { |
353 | int i, err = 0; |
354 | if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) { |
355 | printk(KERN_ERR "coda_psdev: unable to get major %d\n", |
356 | CODA_PSDEV_MAJOR); |
357 | return -EIO; |
358 | } |
359 | coda_psdev_class = class_create(THIS_MODULE, "coda"); |
360 | if (IS_ERR(coda_psdev_class)) { |
361 | err = PTR_ERR(coda_psdev_class); |
362 | goto out_chrdev; |
363 | } |
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); |
367 | coda_sysctl_init(); |
368 | goto out; |
369 | |
370 | out_chrdev: |
371 | unregister_chrdev(CODA_PSDEV_MAJOR, "coda"); |
372 | out: |
373 | return err; |
374 | } |
375 | |
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"); |
381 | |
382 | static int __init init_coda(void) |
383 | { |
384 | int status; |
385 | int i; |
386 | |
387 | status = coda_init_inodecache(); |
388 | if (status) |
389 | goto out2; |
390 | status = init_coda_psdev(); |
391 | if ( status ) { |
392 | printk("Problem (%d) in init_coda_psdev\n", status); |
393 | goto out1; |
394 | } |
395 | |
396 | status = register_filesystem(&coda_fs_type); |
397 | if (status) { |
398 | printk("coda: failed to register filesystem!\n"); |
399 | goto out; |
400 | } |
401 | return 0; |
402 | out: |
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"); |
407 | coda_sysctl_clean(); |
408 | out1: |
409 | coda_destroy_inodecache(); |
410 | out2: |
411 | return status; |
412 | } |
413 | |
414 | static void __exit exit_coda(void) |
415 | { |
416 | int err, i; |
417 | |
418 | err = unregister_filesystem(&coda_fs_type); |
419 | if ( err != 0 ) { |
420 | printk("coda: failed to unregister filesystem\n"); |
421 | } |
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"); |
426 | coda_sysctl_clean(); |
427 | coda_destroy_inodecache(); |
428 | } |
429 | |
430 | module_init(init_coda); |
431 | module_exit(exit_coda); |
432 | |
433 |
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