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Tejun Heo151060a2009-04-14 10:54:54 +09001/*
2 * CUSE: Character device in Userspace
3 *
4 * Copyright (C) 2008-2009 SUSE Linux Products GmbH
5 * Copyright (C) 2008-2009 Tejun Heo <tj@kernel.org>
6 *
7 * This file is released under the GPLv2.
8 *
9 * CUSE enables character devices to be implemented from userland much
10 * like FUSE allows filesystems. On initialization /dev/cuse is
11 * created. By opening the file and replying to the CUSE_INIT request
12 * userland CUSE server can create a character device. After that the
13 * operation is very similar to FUSE.
14 *
15 * A CUSE instance involves the following objects.
16 *
17 * cuse_conn : contains fuse_conn and serves as bonding structure
18 * channel : file handle connected to the userland CUSE server
19 * cdev : the implemented character device
20 * dev : generic device for cdev
21 *
22 * Note that 'channel' is what 'dev' is in FUSE. As CUSE deals with
23 * devices, it's called 'channel' to reduce confusion.
24 *
25 * channel determines when the character device dies. When channel is
26 * closed, everything begins to destruct. The cuse_conn is taken off
27 * the lookup table preventing further access from cdev, cdev and
28 * generic device are removed and the base reference of cuse_conn is
29 * put.
30 *
31 * On each open, the matching cuse_conn is looked up and if found an
32 * additional reference is taken which is released when the file is
33 * closed.
34 */
35
36#include <linux/fuse.h>
37#include <linux/cdev.h>
38#include <linux/device.h>
39#include <linux/file.h>
40#include <linux/fs.h>
Kent Overstreeta27bb332013-05-07 16:19:08 -070041#include <linux/aio.h>
Tejun Heo151060a2009-04-14 10:54:54 +090042#include <linux/kdev_t.h>
43#include <linux/kthread.h>
44#include <linux/list.h>
45#include <linux/magic.h>
46#include <linux/miscdevice.h>
47#include <linux/mutex.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090048#include <linux/slab.h>
Tejun Heo151060a2009-04-14 10:54:54 +090049#include <linux/stat.h>
Paul Gortmaker143cb492011-07-01 14:23:34 -040050#include <linux/module.h>
Tejun Heo151060a2009-04-14 10:54:54 +090051
52#include "fuse_i.h"
53
54#define CUSE_CONNTBL_LEN 64
55
56struct cuse_conn {
57 struct list_head list; /* linked on cuse_conntbl */
58 struct fuse_conn fc; /* fuse connection */
59 struct cdev *cdev; /* associated character device */
60 struct device *dev; /* device representing @cdev */
61
62 /* init parameters, set once during initialization */
63 bool unrestricted_ioctl;
64};
65
David Herrmann8ce03fd2012-11-17 12:45:47 +010066static DEFINE_MUTEX(cuse_lock); /* protects registration */
Tejun Heo151060a2009-04-14 10:54:54 +090067static struct list_head cuse_conntbl[CUSE_CONNTBL_LEN];
68static struct class *cuse_class;
69
70static struct cuse_conn *fc_to_cc(struct fuse_conn *fc)
71{
72 return container_of(fc, struct cuse_conn, fc);
73}
74
75static struct list_head *cuse_conntbl_head(dev_t devt)
76{
77 return &cuse_conntbl[(MAJOR(devt) + MINOR(devt)) % CUSE_CONNTBL_LEN];
78}
79
80
81/**************************************************************************
82 * CUSE frontend operations
83 *
84 * These are file operations for the character device.
85 *
86 * On open, CUSE opens a file from the FUSE mnt and stores it to
87 * private_data of the open file. All other ops call FUSE ops on the
88 * FUSE file.
89 */
90
91static ssize_t cuse_read(struct file *file, char __user *buf, size_t count,
92 loff_t *ppos)
93{
94 loff_t pos = 0;
Miklos Szeredifb05f412012-11-10 16:55:56 +010095 struct iovec iov = { .iov_base = buf, .iov_len = count };
Maxim Patlasov36cf66e2012-12-14 19:20:51 +040096 struct fuse_io_priv io = { .async = 0, .file = file };
Al Virod22a9432014-03-16 15:50:47 -040097 struct iov_iter ii;
98 iov_iter_init(&ii, READ, &iov, 1, count);
Tejun Heo151060a2009-04-14 10:54:54 +090099
Al Virod22a9432014-03-16 15:50:47 -0400100 return fuse_direct_io(&io, &ii, &pos, FUSE_DIO_CUSE);
Tejun Heo151060a2009-04-14 10:54:54 +0900101}
102
103static ssize_t cuse_write(struct file *file, const char __user *buf,
104 size_t count, loff_t *ppos)
105{
106 loff_t pos = 0;
Miklos Szeredifb05f412012-11-10 16:55:56 +0100107 struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
Maxim Patlasov36cf66e2012-12-14 19:20:51 +0400108 struct fuse_io_priv io = { .async = 0, .file = file };
Al Virod22a9432014-03-16 15:50:47 -0400109 struct iov_iter ii;
110 iov_iter_init(&ii, WRITE, &iov, 1, count);
Miklos Szeredifb05f412012-11-10 16:55:56 +0100111
Tejun Heo151060a2009-04-14 10:54:54 +0900112 /*
113 * No locking or generic_write_checks(), the server is
114 * responsible for locking and sanity checks.
115 */
Al Virod22a9432014-03-16 15:50:47 -0400116 return fuse_direct_io(&io, &ii, &pos,
Pavel Emelyanovea8cd332013-10-10 17:12:05 +0400117 FUSE_DIO_WRITE | FUSE_DIO_CUSE);
Tejun Heo151060a2009-04-14 10:54:54 +0900118}
119
120static int cuse_open(struct inode *inode, struct file *file)
121{
122 dev_t devt = inode->i_cdev->dev;
123 struct cuse_conn *cc = NULL, *pos;
124 int rc;
125
126 /* look up and get the connection */
David Herrmann8ce03fd2012-11-17 12:45:47 +0100127 mutex_lock(&cuse_lock);
Tejun Heo151060a2009-04-14 10:54:54 +0900128 list_for_each_entry(pos, cuse_conntbl_head(devt), list)
129 if (pos->dev->devt == devt) {
130 fuse_conn_get(&pos->fc);
131 cc = pos;
132 break;
133 }
David Herrmann8ce03fd2012-11-17 12:45:47 +0100134 mutex_unlock(&cuse_lock);
Tejun Heo151060a2009-04-14 10:54:54 +0900135
136 /* dead? */
137 if (!cc)
138 return -ENODEV;
139
140 /*
141 * Generic permission check is already done against the chrdev
142 * file, proceed to open.
143 */
144 rc = fuse_do_open(&cc->fc, 0, file, 0);
145 if (rc)
146 fuse_conn_put(&cc->fc);
147 return rc;
148}
149
150static int cuse_release(struct inode *inode, struct file *file)
151{
152 struct fuse_file *ff = file->private_data;
153 struct fuse_conn *fc = ff->fc;
154
155 fuse_sync_release(ff, file->f_flags);
156 fuse_conn_put(fc);
157
158 return 0;
159}
160
161static long cuse_file_ioctl(struct file *file, unsigned int cmd,
162 unsigned long arg)
163{
164 struct fuse_file *ff = file->private_data;
165 struct cuse_conn *cc = fc_to_cc(ff->fc);
166 unsigned int flags = 0;
167
168 if (cc->unrestricted_ioctl)
169 flags |= FUSE_IOCTL_UNRESTRICTED;
170
171 return fuse_do_ioctl(file, cmd, arg, flags);
172}
173
174static long cuse_file_compat_ioctl(struct file *file, unsigned int cmd,
175 unsigned long arg)
176{
177 struct fuse_file *ff = file->private_data;
178 struct cuse_conn *cc = fc_to_cc(ff->fc);
179 unsigned int flags = FUSE_IOCTL_COMPAT;
180
181 if (cc->unrestricted_ioctl)
182 flags |= FUSE_IOCTL_UNRESTRICTED;
183
184 return fuse_do_ioctl(file, cmd, arg, flags);
185}
186
187static const struct file_operations cuse_frontend_fops = {
188 .owner = THIS_MODULE,
189 .read = cuse_read,
190 .write = cuse_write,
191 .open = cuse_open,
192 .release = cuse_release,
193 .unlocked_ioctl = cuse_file_ioctl,
194 .compat_ioctl = cuse_file_compat_ioctl,
195 .poll = fuse_file_poll,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200196 .llseek = noop_llseek,
Tejun Heo151060a2009-04-14 10:54:54 +0900197};
198
199
200/**************************************************************************
201 * CUSE channel initialization and destruction
202 */
203
204struct cuse_devinfo {
205 const char *name;
206};
207
208/**
209 * cuse_parse_one - parse one key=value pair
210 * @pp: i/o parameter for the current position
211 * @end: points to one past the end of the packed string
212 * @keyp: out parameter for key
213 * @valp: out parameter for value
214 *
215 * *@pp points to packed strings - "key0=val0\0key1=val1\0" which ends
216 * at @end - 1. This function parses one pair and set *@keyp to the
217 * start of the key and *@valp to the start of the value. Note that
218 * the original string is modified such that the key string is
219 * terminated with '\0'. *@pp is updated to point to the next string.
220 *
221 * RETURNS:
222 * 1 on successful parse, 0 on EOF, -errno on failure.
223 */
224static int cuse_parse_one(char **pp, char *end, char **keyp, char **valp)
225{
226 char *p = *pp;
227 char *key, *val;
228
229 while (p < end && *p == '\0')
230 p++;
231 if (p == end)
232 return 0;
233
234 if (end[-1] != '\0') {
235 printk(KERN_ERR "CUSE: info not properly terminated\n");
236 return -EINVAL;
237 }
238
239 key = val = p;
240 p += strlen(p);
241
242 if (valp) {
243 strsep(&val, "=");
244 if (!val)
245 val = key + strlen(key);
246 key = strstrip(key);
247 val = strstrip(val);
248 } else
249 key = strstrip(key);
250
251 if (!strlen(key)) {
252 printk(KERN_ERR "CUSE: zero length info key specified\n");
253 return -EINVAL;
254 }
255
256 *pp = p;
257 *keyp = key;
258 if (valp)
259 *valp = val;
260
261 return 1;
262}
263
264/**
265 * cuse_parse_dev_info - parse device info
266 * @p: device info string
267 * @len: length of device info string
268 * @devinfo: out parameter for parsed device info
269 *
270 * Parse @p to extract device info and store it into @devinfo. String
271 * pointed to by @p is modified by parsing and @devinfo points into
272 * them, so @p shouldn't be freed while @devinfo is in use.
273 *
274 * RETURNS:
275 * 0 on success, -errno on failure.
276 */
277static int cuse_parse_devinfo(char *p, size_t len, struct cuse_devinfo *devinfo)
278{
279 char *end = p + len;
Miklos Szeredie2560362013-01-15 12:24:46 +0100280 char *uninitialized_var(key), *uninitialized_var(val);
Tejun Heo151060a2009-04-14 10:54:54 +0900281 int rc;
282
283 while (true) {
284 rc = cuse_parse_one(&p, end, &key, &val);
285 if (rc < 0)
286 return rc;
287 if (!rc)
288 break;
289 if (strcmp(key, "DEVNAME") == 0)
290 devinfo->name = val;
291 else
292 printk(KERN_WARNING "CUSE: unknown device info \"%s\"\n",
293 key);
294 }
295
296 if (!devinfo->name || !strlen(devinfo->name)) {
297 printk(KERN_ERR "CUSE: DEVNAME unspecified\n");
298 return -EINVAL;
299 }
300
301 return 0;
302}
303
304static void cuse_gendev_release(struct device *dev)
305{
306 kfree(dev);
307}
308
309/**
310 * cuse_process_init_reply - finish initializing CUSE channel
311 *
312 * This function creates the character device and sets up all the
313 * required data structures for it. Please read the comment at the
314 * top of this file for high level overview.
315 */
316static void cuse_process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
317{
David Herrmann30783582012-11-17 12:45:48 +0100318 struct cuse_conn *cc = fc_to_cc(fc), *pos;
Miklos Szeredi07d5f692011-03-21 13:58:05 +0100319 struct cuse_init_out *arg = req->out.args[0].value;
Tejun Heo151060a2009-04-14 10:54:54 +0900320 struct page *page = req->pages[0];
321 struct cuse_devinfo devinfo = { };
322 struct device *dev;
323 struct cdev *cdev;
324 dev_t devt;
David Herrmann30783582012-11-17 12:45:48 +0100325 int rc, i;
Tejun Heo151060a2009-04-14 10:54:54 +0900326
327 if (req->out.h.error ||
328 arg->major != FUSE_KERNEL_VERSION || arg->minor < 11) {
329 goto err;
330 }
331
332 fc->minor = arg->minor;
333 fc->max_read = max_t(unsigned, arg->max_read, 4096);
334 fc->max_write = max_t(unsigned, arg->max_write, 4096);
335
336 /* parse init reply */
337 cc->unrestricted_ioctl = arg->flags & CUSE_UNRESTRICTED_IOCTL;
338
339 rc = cuse_parse_devinfo(page_address(page), req->out.args[1].size,
340 &devinfo);
341 if (rc)
342 goto err;
343
344 /* determine and reserve devt */
345 devt = MKDEV(arg->dev_major, arg->dev_minor);
346 if (!MAJOR(devt))
347 rc = alloc_chrdev_region(&devt, MINOR(devt), 1, devinfo.name);
348 else
349 rc = register_chrdev_region(devt, 1, devinfo.name);
350 if (rc) {
351 printk(KERN_ERR "CUSE: failed to register chrdev region\n");
352 goto err;
353 }
354
355 /* devt determined, create device */
356 rc = -ENOMEM;
357 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
358 if (!dev)
359 goto err_region;
360
361 device_initialize(dev);
362 dev_set_uevent_suppress(dev, 1);
363 dev->class = cuse_class;
364 dev->devt = devt;
365 dev->release = cuse_gendev_release;
366 dev_set_drvdata(dev, cc);
367 dev_set_name(dev, "%s", devinfo.name);
368
David Herrmann30783582012-11-17 12:45:48 +0100369 mutex_lock(&cuse_lock);
370
371 /* make sure the device-name is unique */
372 for (i = 0; i < CUSE_CONNTBL_LEN; ++i) {
373 list_for_each_entry(pos, &cuse_conntbl[i], list)
374 if (!strcmp(dev_name(pos->dev), dev_name(dev)))
375 goto err_unlock;
376 }
377
Tejun Heo151060a2009-04-14 10:54:54 +0900378 rc = device_add(dev);
379 if (rc)
David Herrmann30783582012-11-17 12:45:48 +0100380 goto err_unlock;
Tejun Heo151060a2009-04-14 10:54:54 +0900381
382 /* register cdev */
383 rc = -ENOMEM;
384 cdev = cdev_alloc();
385 if (!cdev)
David Herrmann30783582012-11-17 12:45:48 +0100386 goto err_unlock;
Tejun Heo151060a2009-04-14 10:54:54 +0900387
388 cdev->owner = THIS_MODULE;
389 cdev->ops = &cuse_frontend_fops;
390
391 rc = cdev_add(cdev, devt, 1);
392 if (rc)
393 goto err_cdev;
394
395 cc->dev = dev;
396 cc->cdev = cdev;
397
398 /* make the device available */
Tejun Heo151060a2009-04-14 10:54:54 +0900399 list_add(&cc->list, cuse_conntbl_head(devt));
David Herrmann8ce03fd2012-11-17 12:45:47 +0100400 mutex_unlock(&cuse_lock);
Tejun Heo151060a2009-04-14 10:54:54 +0900401
402 /* announce device availability */
403 dev_set_uevent_suppress(dev, 0);
404 kobject_uevent(&dev->kobj, KOBJ_ADD);
405out:
Miklos Szeredi07d5f692011-03-21 13:58:05 +0100406 kfree(arg);
Tejun Heo151060a2009-04-14 10:54:54 +0900407 __free_page(page);
408 return;
409
410err_cdev:
411 cdev_del(cdev);
David Herrmann30783582012-11-17 12:45:48 +0100412err_unlock:
413 mutex_unlock(&cuse_lock);
Tejun Heo151060a2009-04-14 10:54:54 +0900414 put_device(dev);
415err_region:
416 unregister_chrdev_region(devt, 1);
417err:
Miklos Szeredi580640b2014-12-12 09:49:04 +0100418 fuse_abort_conn(fc);
Tejun Heo151060a2009-04-14 10:54:54 +0900419 goto out;
420}
421
422static int cuse_send_init(struct cuse_conn *cc)
423{
424 int rc;
425 struct fuse_req *req;
426 struct page *page;
427 struct fuse_conn *fc = &cc->fc;
428 struct cuse_init_in *arg;
Miklos Szeredi07d5f692011-03-21 13:58:05 +0100429 void *outarg;
Tejun Heo151060a2009-04-14 10:54:54 +0900430
431 BUILD_BUG_ON(CUSE_INIT_INFO_MAX > PAGE_SIZE);
432
Maxim Patlasov8b41e672013-03-21 18:02:04 +0400433 req = fuse_get_req_for_background(fc, 1);
Tejun Heo151060a2009-04-14 10:54:54 +0900434 if (IS_ERR(req)) {
435 rc = PTR_ERR(req);
436 goto err;
437 }
438
439 rc = -ENOMEM;
440 page = alloc_page(GFP_KERNEL | __GFP_ZERO);
441 if (!page)
442 goto err_put_req;
443
Miklos Szeredi07d5f692011-03-21 13:58:05 +0100444 outarg = kzalloc(sizeof(struct cuse_init_out), GFP_KERNEL);
445 if (!outarg)
446 goto err_free_page;
447
Tejun Heo151060a2009-04-14 10:54:54 +0900448 arg = &req->misc.cuse_init_in;
449 arg->major = FUSE_KERNEL_VERSION;
450 arg->minor = FUSE_KERNEL_MINOR_VERSION;
451 arg->flags |= CUSE_UNRESTRICTED_IOCTL;
452 req->in.h.opcode = CUSE_INIT;
453 req->in.numargs = 1;
454 req->in.args[0].size = sizeof(struct cuse_init_in);
455 req->in.args[0].value = arg;
456 req->out.numargs = 2;
457 req->out.args[0].size = sizeof(struct cuse_init_out);
Miklos Szeredi07d5f692011-03-21 13:58:05 +0100458 req->out.args[0].value = outarg;
Tejun Heo151060a2009-04-14 10:54:54 +0900459 req->out.args[1].size = CUSE_INIT_INFO_MAX;
460 req->out.argvar = 1;
461 req->out.argpages = 1;
462 req->pages[0] = page;
Maxim Patlasov85f40ae2012-10-26 19:49:33 +0400463 req->page_descs[0].length = req->out.args[1].size;
Tejun Heo151060a2009-04-14 10:54:54 +0900464 req->num_pages = 1;
465 req->end = cuse_process_init_reply;
466 fuse_request_send_background(fc, req);
467
468 return 0;
469
Miklos Szeredi07d5f692011-03-21 13:58:05 +0100470err_free_page:
471 __free_page(page);
Tejun Heo151060a2009-04-14 10:54:54 +0900472err_put_req:
473 fuse_put_request(fc, req);
474err:
475 return rc;
476}
477
478static void cuse_fc_release(struct fuse_conn *fc)
479{
480 struct cuse_conn *cc = fc_to_cc(fc);
Al Virodd3e2c52013-10-03 21:21:39 -0400481 kfree_rcu(cc, fc.rcu);
Tejun Heo151060a2009-04-14 10:54:54 +0900482}
483
484/**
485 * cuse_channel_open - open method for /dev/cuse
486 * @inode: inode for /dev/cuse
487 * @file: file struct being opened
488 *
489 * Userland CUSE server can create a CUSE device by opening /dev/cuse
Paul Bolle8272f4c2011-02-15 00:05:34 +0100490 * and replying to the initialization request kernel sends. This
Tejun Heo151060a2009-04-14 10:54:54 +0900491 * function is responsible for handling CUSE device initialization.
492 * Because the fd opened by this function is used during
493 * initialization, this function only creates cuse_conn and sends
494 * init. The rest is delegated to a kthread.
495 *
496 * RETURNS:
497 * 0 on success, -errno on failure.
498 */
499static int cuse_channel_open(struct inode *inode, struct file *file)
500{
501 struct cuse_conn *cc;
502 int rc;
503
504 /* set up cuse_conn */
505 cc = kzalloc(sizeof(*cc), GFP_KERNEL);
506 if (!cc)
507 return -ENOMEM;
508
509 fuse_conn_init(&cc->fc);
510
511 INIT_LIST_HEAD(&cc->list);
512 cc->fc.release = cuse_fc_release;
513
514 cc->fc.connected = 1;
Maxim Patlasov796523fb2013-03-21 18:02:15 +0400515 cc->fc.initialized = 1;
Tejun Heo151060a2009-04-14 10:54:54 +0900516 rc = cuse_send_init(cc);
517 if (rc) {
518 fuse_conn_put(&cc->fc);
519 return rc;
520 }
521 file->private_data = &cc->fc; /* channel owns base reference to cc */
522
523 return 0;
524}
525
526/**
527 * cuse_channel_release - release method for /dev/cuse
528 * @inode: inode for /dev/cuse
529 * @file: file struct being closed
530 *
531 * Disconnect the channel, deregister CUSE device and initiate
532 * destruction by putting the default reference.
533 *
534 * RETURNS:
535 * 0 on success, -errno on failure.
536 */
537static int cuse_channel_release(struct inode *inode, struct file *file)
538{
539 struct cuse_conn *cc = fc_to_cc(file->private_data);
540 int rc;
541
542 /* remove from the conntbl, no more access from this point on */
David Herrmann8ce03fd2012-11-17 12:45:47 +0100543 mutex_lock(&cuse_lock);
Tejun Heo151060a2009-04-14 10:54:54 +0900544 list_del_init(&cc->list);
David Herrmann8ce03fd2012-11-17 12:45:47 +0100545 mutex_unlock(&cuse_lock);
Tejun Heo151060a2009-04-14 10:54:54 +0900546
547 /* remove device */
548 if (cc->dev)
549 device_unregister(cc->dev);
550 if (cc->cdev) {
551 unregister_chrdev_region(cc->cdev->dev, 1);
552 cdev_del(cc->cdev);
553 }
554
Tejun Heo151060a2009-04-14 10:54:54 +0900555 rc = fuse_dev_release(inode, file); /* puts the base reference */
556
557 return rc;
558}
559
560static struct file_operations cuse_channel_fops; /* initialized during init */
561
562
563/**************************************************************************
564 * Misc stuff and module initializatiion
565 *
566 * CUSE exports the same set of attributes to sysfs as fusectl.
567 */
568
569static ssize_t cuse_class_waiting_show(struct device *dev,
570 struct device_attribute *attr, char *buf)
571{
572 struct cuse_conn *cc = dev_get_drvdata(dev);
573
574 return sprintf(buf, "%d\n", atomic_read(&cc->fc.num_waiting));
575}
Rusty Russell58f86cc2014-03-24 12:00:34 +1030576static DEVICE_ATTR(waiting, 0400, cuse_class_waiting_show, NULL);
Tejun Heo151060a2009-04-14 10:54:54 +0900577
578static ssize_t cuse_class_abort_store(struct device *dev,
579 struct device_attribute *attr,
580 const char *buf, size_t count)
581{
582 struct cuse_conn *cc = dev_get_drvdata(dev);
583
584 fuse_abort_conn(&cc->fc);
585 return count;
586}
Rusty Russell58f86cc2014-03-24 12:00:34 +1030587static DEVICE_ATTR(abort, 0200, NULL, cuse_class_abort_store);
Tejun Heo151060a2009-04-14 10:54:54 +0900588
Greg Kroah-Hartman4183fb92013-07-24 15:05:24 -0700589static struct attribute *cuse_class_dev_attrs[] = {
590 &dev_attr_waiting.attr,
591 &dev_attr_abort.attr,
592 NULL,
Tejun Heo151060a2009-04-14 10:54:54 +0900593};
Greg Kroah-Hartman4183fb92013-07-24 15:05:24 -0700594ATTRIBUTE_GROUPS(cuse_class_dev);
Tejun Heo151060a2009-04-14 10:54:54 +0900595
596static struct miscdevice cuse_miscdev = {
Tom Gundersencb2ffb22013-09-09 20:18:27 +0200597 .minor = CUSE_MINOR,
Tejun Heo151060a2009-04-14 10:54:54 +0900598 .name = "cuse",
599 .fops = &cuse_channel_fops,
600};
601
Tom Gundersencb2ffb22013-09-09 20:18:27 +0200602MODULE_ALIAS_MISCDEV(CUSE_MINOR);
603MODULE_ALIAS("devname:cuse");
604
Tejun Heo151060a2009-04-14 10:54:54 +0900605static int __init cuse_init(void)
606{
607 int i, rc;
608
609 /* init conntbl */
610 for (i = 0; i < CUSE_CONNTBL_LEN; i++)
611 INIT_LIST_HEAD(&cuse_conntbl[i]);
612
613 /* inherit and extend fuse_dev_operations */
614 cuse_channel_fops = fuse_dev_operations;
615 cuse_channel_fops.owner = THIS_MODULE;
616 cuse_channel_fops.open = cuse_channel_open;
617 cuse_channel_fops.release = cuse_channel_release;
618
619 cuse_class = class_create(THIS_MODULE, "cuse");
620 if (IS_ERR(cuse_class))
621 return PTR_ERR(cuse_class);
622
Greg Kroah-Hartman4183fb92013-07-24 15:05:24 -0700623 cuse_class->dev_groups = cuse_class_dev_groups;
Tejun Heo151060a2009-04-14 10:54:54 +0900624
625 rc = misc_register(&cuse_miscdev);
626 if (rc) {
627 class_destroy(cuse_class);
628 return rc;
629 }
630
631 return 0;
632}
633
634static void __exit cuse_exit(void)
635{
636 misc_deregister(&cuse_miscdev);
637 class_destroy(cuse_class);
638}
639
640module_init(cuse_init);
641module_exit(cuse_exit);
642
643MODULE_AUTHOR("Tejun Heo <tj@kernel.org>");
644MODULE_DESCRIPTION("Character device in Userspace");
645MODULE_LICENSE("GPL");