aboutsummaryrefslogtreecommitdiffstats
path: root/fs/coda/psdev.c
blob: ebc2bae6c289038803f4542f88fc8291c5006c8d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
/*
 *      	An implementation of a loadable kernel mode driver providing
 *		multiple kernel/user space bidirectional communications links.
 *
 * 		Author: 	Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 * 
 *              Adapted to become the Linux 2.0 Coda pseudo device
 *              Peter  Braam  <braam@maths.ox.ac.uk> 
 *              Michael Callahan <mjc@emmy.smith.edu>           
 *
 *              Changes for Linux 2.1
 *              Copyright (c) 1997 Carnegie-Mellon University
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <linux/delay.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/pid_namespace.h>
#include <asm/io.h>
#include <asm/poll.h>
#include <asm/uaccess.h>

#include <linux/coda.h>
#include <linux/coda_psdev.h>

#include "coda_linux.h"

#include "coda_int.h"

/* statistics */
int           coda_hard;         /* allows signals during upcalls */
unsigned long coda_timeout = 30; /* .. secs, then signals will dequeue */


struct venus_comm coda_comms[MAX_CODADEVS];
static struct class *coda_psdev_class;

/*
 * Device operations
 */

static unsigned int coda_psdev_poll(struct file *file, poll_table * wait)
{
        struct venus_comm *vcp = (struct venus_comm *) file->private_data;
	unsigned int mask = POLLOUT | POLLWRNORM;

	poll_wait(file, &vcp->vc_waitq, wait);
	mutex_lock(&vcp->vc_mutex);
	if (!list_empty(&vcp->vc_pending))
                mask |= POLLIN | POLLRDNORM;
	mutex_unlock(&vcp->vc_mutex);

	return mask;
}

static long coda_psdev_ioctl(struct file * filp, unsigned int cmd, unsigned long arg)
{
	unsigned int data;

	switch(cmd) {
	case CIOC_KERNEL_VERSION:
		data = CODA_KERNEL_VERSION;
		return put_user(data, (int __user *) arg);
	default:
		return -ENOTTY;
	}

	return 0;
}

/*
 *	Receive a message written by Venus to the psdev
 */
 
static ssize_t coda_psdev_write(struct file *file, const char __user *buf, 
				size_t nbytes, loff_t *off)
{
        struct venus_comm *vcp = (struct venus_comm *) file->private_data;
        struct upc_req *req = NULL;
        struct upc_req *tmp;
	struct list_head *lh;
	struct coda_in_hdr hdr;
	ssize_t retval = 0, count = 0;
	int error;

        /* Peek at the opcode, uniquefier */
	if (copy_from_user(&hdr, buf, 2 * sizeof(u_long)))
	        return -EFAULT;

        if (DOWNCALL(hdr.opcode)) {
		union outputArgs *dcbuf;
		int size = sizeof(*dcbuf);

		if  ( nbytes < sizeof(struct coda_out_hdr) ) {
		        printk("coda_downcall opc %d uniq %d, not enough!\n",
			       hdr.opcode, hdr.unique);
			count = nbytes;
			goto out;
		}
		if ( nbytes > size ) {
		        printk("Coda: downcall opc %d, uniq %d, too much!",
			       hdr.opcode, hdr.unique);
		        nbytes = size;
		}
		CODA_ALLOC(dcbuf, union outputArgs *, nbytes);
		if (copy_from_user(dcbuf, buf, nbytes)) {
			CODA_FREE(dcbuf, nbytes);
			retval = -EFAULT;
			goto out;
		}

		/* what downcall errors does Venus handle ? */
		error = coda_downcall(vcp, hdr.opcode, dcbuf);

		CODA_FREE(dcbuf, nbytes);
		if (error) {
		        printk("psdev_write: coda_downcall error: %d\n", error);
			retval = error;
			goto out;
		}
		count = nbytes;
		goto out;
	}
        
	/* Look for the message on the processing queue. */
	mutex_lock(&vcp->vc_mutex);
	list_for_each(lh, &vcp->vc_processing) {
		tmp = list_entry(lh, struct upc_req , uc_chain);
		if (tmp->uc_unique == hdr.unique) {
			req = tmp;
			list_del(&req->uc_chain);
			break;
		}
	}
	mutex_unlock(&vcp->vc_mutex);

	if (!req) {
		printk("psdev_write: msg (%d, %d) not found\n", 
			hdr.opcode, hdr.unique);
		retval = -ESRCH;
		goto out;
	}

        /* move data into response buffer. */
	if (req->uc_outSize < nbytes) {
                printk("psdev_write: too much cnt: %d, cnt: %ld, opc: %d, uniq: %d.\n",
		       req->uc_outSize, (long)nbytes, hdr.opcode, hdr.unique);
		nbytes = req->uc_outSize; /* don't have more space! */
	}
        if (copy_from_user(req->uc_data, buf, nbytes)) {
		req->uc_flags |= CODA_REQ_ABORT;
		wake_up(&req->uc_sleep);
		retval = -EFAULT;
		goto out;
	}

	/* adjust outsize. is this useful ?? */
	req->uc_outSize = nbytes;
	req->uc_flags |= CODA_REQ_WRITE;
	count = nbytes;

	/* Convert filedescriptor into a file handle */
	if (req->uc_opcode == CODA_OPEN_BY_FD) {
		struct coda_open_by_fd_out *outp =
			(struct coda_open_by_fd_out *)req->uc_data;
		if (!outp->oh.result)
			outp->fh = fget(outp->fd);
	}

        wake_up(&req->uc_sleep);
out:
        return(count ? count : retval);  
}

/*
 *	Read a message from the kernel to Venus
 */

static ssize_t coda_psdev_read(struct file * file, char __user * buf, 
			       size_t nbytes, loff_t *off)
{
	DECLARE_WAITQUEUE(wait, current);
        struct venus_comm *vcp = (struct venus_comm *) file->private_data;
        struct upc_req *req;
	ssize_t retval = 0, count = 0;

	if (nbytes == 0)
		return 0;

	mutex_lock(&vcp->vc_mutex);

	add_wait_queue(&vcp->vc_waitq, &wait);
	set_current_state(TASK_INTERRUPTIBLE);

	while (list_empty(&vcp->vc_pending)) {
		if (file->f_flags & O_NONBLOCK) {
			retval = -EAGAIN;
			break;
		}
		if (signal_pending(current)) {
			retval = -ERESTARTSYS;
			break;
		}
		mutex_unlock(&vcp->vc_mutex);
		schedule();
		mutex_lock(&vcp->vc_mutex);
	}

	set_current_state(TASK_RUNNING);
	remove_wait_queue(&vcp->vc_waitq, &wait);

	if (retval)
		goto out;

	req = list_entry(vcp->vc_pending.next, struct upc_req,uc_chain);
	list_del(&req->uc_chain);

	/* Move the input args into userspace */
	count = req->uc_inSize;
	if (nbytes < req->uc_inSize) {
                printk ("psdev_read: Venus read %ld bytes of %d in message\n",
			(long)nbytes, req->uc_inSize);
		count = nbytes;
        }

	if (copy_to_user(buf, req->uc_data, count))
	        retval = -EFAULT;
        
	/* If request was not a signal, enqueue and don't free */
	if (!(req->uc_flags & CODA_REQ_ASYNC)) {
		req->uc_flags |= CODA_REQ_READ;
		list_add_tail(&(req->uc_chain), &vcp->vc_processing);
		goto out;
	}

	CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
	kfree(req);
out:
	mutex_unlock(&vcp->vc_mutex);
	return (count ? count : retval);
}

static int coda_psdev_open(struct inode * inode, struct file * file)
{
	struct venus_comm *vcp;
	int idx, err;

	if (task_active_pid_ns(current) != &init_pid_ns)
		return -EINVAL;

	if (current_user_ns() != &init_user_ns)
		return -EINVAL;

	idx = iminor(inode);
	if (idx < 0 || idx >= MAX_CODADEVS)
		return -ENODEV;

	err = -EBUSY;
	vcp = &coda_comms[idx];
	mutex_lock(&vcp->vc_mutex);

	if (!vcp->vc_inuse) {
		vcp->vc_inuse++;

		INIT_LIST_HEAD(&vcp->vc_pending);
		INIT_LIST_HEAD(&vcp->vc_processing);
		init_waitqueue_head(&vcp->vc_waitq);
		vcp->vc_sb = NULL;
		vcp->vc_seq = 0;

		file->private_data = vcp;
		err = 0;
	}

	mutex_unlock(&vcp->vc_mutex);
	return err;
}


static int coda_psdev_release(struct inode * inode, struct file * file)
{
	struct venus_comm *vcp = (struct venus_comm *) file->private_data;
	struct upc_req *req, *tmp;

	if (!vcp || !vcp->vc_inuse ) {
		printk("psdev_release: Not open.\n");
		return -1;
	}

	mutex_lock(&vcp->vc_mutex);

	/* Wakeup clients so they can return. */
	list_for_each_entry_safe(req, tmp, &vcp->vc_pending, uc_chain) {
		list_del(&req->uc_chain);

		/* Async requests need to be freed here */
		if (req->uc_flags & CODA_REQ_ASYNC) {
			CODA_FREE(req->uc_data, sizeof(struct coda_in_hdr));
			kfree(req);
			continue;
		}
		req->uc_flags |= CODA_REQ_ABORT;
		wake_up(&req->uc_sleep);
	}

	list_for_each_entry_safe(req, tmp, &vcp->vc_processing, uc_chain) {
		list_del(&req->uc_chain);

		req->uc_flags |= CODA_REQ_ABORT;
		wake_up(&req->uc_sleep);
	}

	file->private_data = NULL;
	vcp->vc_inuse--;
	mutex_unlock(&vcp->vc_mutex);
	return 0;
}


static const struct file_operations coda_psdev_fops = {
	.owner		= THIS_MODULE,
	.read		= coda_psdev_read,
	.write		= coda_psdev_write,
	.poll		= coda_psdev_poll,
	.unlocked_ioctl	= coda_psdev_ioctl,
	.open		= coda_psdev_open,
	.release	= coda_psdev_release,
	.llseek		= noop_llseek,
};

static int init_coda_psdev(void)
{
	int i, err = 0;
	if (register_chrdev(CODA_PSDEV_MAJOR, "coda", &coda_psdev_fops)) {
              printk(KERN_ERR "coda_psdev: unable to get major %d\n", 
		     CODA_PSDEV_MAJOR);
              return -EIO;
	}
	coda_psdev_class = class_create(THIS_MODULE, "coda");
	if (IS_ERR(coda_psdev_class)) {
		err = PTR_ERR(coda_psdev_class);
		goto out_chrdev;
	}		
	for (i = 0; i < MAX_CODADEVS; i++) {
		mutex_init(&(&coda_comms[i])->vc_mutex);
		device_create(coda_psdev_class, NULL,
			      MKDEV(CODA_PSDEV_MAJOR, i), NULL, "cfs%d", i);
	}
	coda_sysctl_init();
	goto out;

out_chrdev:
	unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
out:
	return err;
}

MODULE_AUTHOR("Jan Harkes, Peter J. Braam");
MODULE_DESCRIPTION("Coda Distributed File System VFS interface");
MODULE_ALIAS_CHARDEV_MAJOR(CODA_PSDEV_MAJOR);
MODULE_LICENSE("GPL");
MODULE_VERSION("6.6");

static int __init init_coda(void)
{
	int status;
	int i;

	status = coda_init_inodecache();
	if (status)
		goto out2;
	status = init_coda_psdev();
	if ( status ) {
		printk("Problem (%d) in init_coda_psdev\n", status);
		goto out1;
	}
	
	status = register_filesystem(&coda_fs_type);
	if (status) {
		printk("coda: failed to register filesystem!\n");
		goto out;
	}
	return 0;
out:
	for (i = 0; i < MAX_CODADEVS; i++)
		device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
	class_destroy(coda_psdev_class);
	unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
	coda_sysctl_clean();
out1:
	coda_destroy_inodecache();
out2:
	return status;
}

static void __exit exit_coda(void)
{
        int err, i;

	err = unregister_filesystem(&coda_fs_type);
        if ( err != 0 ) {
                printk("coda: failed to unregister filesystem\n");
        }
	for (i = 0; i < MAX_CODADEVS; i++)
		device_destroy(coda_psdev_class, MKDEV(CODA_PSDEV_MAJOR, i));
	class_destroy(coda_psdev_class);
	unregister_chrdev(CODA_PSDEV_MAJOR, "coda");
	coda_sysctl_clean();
	coda_destroy_inodecache();
}

module_init(init_coda);
module_exit(exit_coda);