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Commit | Line | Data |
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151060ac TH |
1 | /* |
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 | ||
f2294482 KS |
36 | #define pr_fmt(fmt) "CUSE: " fmt |
37 | ||
151060ac TH |
38 | #include <linux/fuse.h> |
39 | #include <linux/cdev.h> | |
40 | #include <linux/device.h> | |
41 | #include <linux/file.h> | |
42 | #include <linux/fs.h> | |
43 | #include <linux/kdev_t.h> | |
44 | #include <linux/kthread.h> | |
45 | #include <linux/list.h> | |
46 | #include <linux/magic.h> | |
47 | #include <linux/miscdevice.h> | |
48 | #include <linux/mutex.h> | |
5a0e3ad6 | 49 | #include <linux/slab.h> |
151060ac | 50 | #include <linux/stat.h> |
143cb494 | 51 | #include <linux/module.h> |
e2e40f2c | 52 | #include <linux/uio.h> |
8cb08329 | 53 | #include <linux/user_namespace.h> |
151060ac TH |
54 | |
55 | #include "fuse_i.h" | |
56 | ||
57 | #define CUSE_CONNTBL_LEN 64 | |
58 | ||
59 | struct cuse_conn { | |
60 | struct list_head list; /* linked on cuse_conntbl */ | |
61 | struct fuse_conn fc; /* fuse connection */ | |
62 | struct cdev *cdev; /* associated character device */ | |
63 | struct device *dev; /* device representing @cdev */ | |
64 | ||
65 | /* init parameters, set once during initialization */ | |
66 | bool unrestricted_ioctl; | |
67 | }; | |
68 | ||
8ce03fd7 | 69 | static DEFINE_MUTEX(cuse_lock); /* protects registration */ |
151060ac TH |
70 | static struct list_head cuse_conntbl[CUSE_CONNTBL_LEN]; |
71 | static struct class *cuse_class; | |
72 | ||
73 | static struct cuse_conn *fc_to_cc(struct fuse_conn *fc) | |
74 | { | |
75 | return container_of(fc, struct cuse_conn, fc); | |
76 | } | |
77 | ||
78 | static struct list_head *cuse_conntbl_head(dev_t devt) | |
79 | { | |
80 | return &cuse_conntbl[(MAJOR(devt) + MINOR(devt)) % CUSE_CONNTBL_LEN]; | |
81 | } | |
82 | ||
83 | ||
84 | /************************************************************************** | |
85 | * CUSE frontend operations | |
86 | * | |
87 | * These are file operations for the character device. | |
88 | * | |
89 | * On open, CUSE opens a file from the FUSE mnt and stores it to | |
90 | * private_data of the open file. All other ops call FUSE ops on the | |
91 | * FUSE file. | |
92 | */ | |
93 | ||
cfa86a74 | 94 | static ssize_t cuse_read_iter(struct kiocb *kiocb, struct iov_iter *to) |
151060ac | 95 | { |
e1c0eecb | 96 | struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(kiocb); |
151060ac TH |
97 | loff_t pos = 0; |
98 | ||
cfa86a74 | 99 | return fuse_direct_io(&io, to, &pos, FUSE_DIO_CUSE); |
151060ac TH |
100 | } |
101 | ||
cfa86a74 | 102 | static ssize_t cuse_write_iter(struct kiocb *kiocb, struct iov_iter *from) |
151060ac | 103 | { |
e1c0eecb | 104 | struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(kiocb); |
151060ac TH |
105 | loff_t pos = 0; |
106 | /* | |
107 | * No locking or generic_write_checks(), the server is | |
108 | * responsible for locking and sanity checks. | |
109 | */ | |
cfa86a74 | 110 | return fuse_direct_io(&io, from, &pos, |
ea8cd333 | 111 | FUSE_DIO_WRITE | FUSE_DIO_CUSE); |
151060ac TH |
112 | } |
113 | ||
114 | static int cuse_open(struct inode *inode, struct file *file) | |
115 | { | |
116 | dev_t devt = inode->i_cdev->dev; | |
117 | struct cuse_conn *cc = NULL, *pos; | |
118 | int rc; | |
119 | ||
120 | /* look up and get the connection */ | |
8ce03fd7 | 121 | mutex_lock(&cuse_lock); |
151060ac TH |
122 | list_for_each_entry(pos, cuse_conntbl_head(devt), list) |
123 | if (pos->dev->devt == devt) { | |
124 | fuse_conn_get(&pos->fc); | |
125 | cc = pos; | |
126 | break; | |
127 | } | |
8ce03fd7 | 128 | mutex_unlock(&cuse_lock); |
151060ac TH |
129 | |
130 | /* dead? */ | |
131 | if (!cc) | |
132 | return -ENODEV; | |
133 | ||
134 | /* | |
135 | * Generic permission check is already done against the chrdev | |
136 | * file, proceed to open. | |
137 | */ | |
138 | rc = fuse_do_open(&cc->fc, 0, file, 0); | |
139 | if (rc) | |
140 | fuse_conn_put(&cc->fc); | |
141 | return rc; | |
142 | } | |
143 | ||
144 | static int cuse_release(struct inode *inode, struct file *file) | |
145 | { | |
ebf84d0c | 146 | struct fuse_inode *fi = get_fuse_inode(inode); |
151060ac TH |
147 | struct fuse_file *ff = file->private_data; |
148 | struct fuse_conn *fc = ff->fc; | |
149 | ||
ebf84d0c | 150 | fuse_sync_release(fi, ff, file->f_flags); |
151060ac TH |
151 | fuse_conn_put(fc); |
152 | ||
153 | return 0; | |
154 | } | |
155 | ||
156 | static long cuse_file_ioctl(struct file *file, unsigned int cmd, | |
157 | unsigned long arg) | |
158 | { | |
159 | struct fuse_file *ff = file->private_data; | |
160 | struct cuse_conn *cc = fc_to_cc(ff->fc); | |
161 | unsigned int flags = 0; | |
162 | ||
163 | if (cc->unrestricted_ioctl) | |
164 | flags |= FUSE_IOCTL_UNRESTRICTED; | |
165 | ||
166 | return fuse_do_ioctl(file, cmd, arg, flags); | |
167 | } | |
168 | ||
169 | static long cuse_file_compat_ioctl(struct file *file, unsigned int cmd, | |
170 | unsigned long arg) | |
171 | { | |
172 | struct fuse_file *ff = file->private_data; | |
173 | struct cuse_conn *cc = fc_to_cc(ff->fc); | |
174 | unsigned int flags = FUSE_IOCTL_COMPAT; | |
175 | ||
176 | if (cc->unrestricted_ioctl) | |
177 | flags |= FUSE_IOCTL_UNRESTRICTED; | |
178 | ||
179 | return fuse_do_ioctl(file, cmd, arg, flags); | |
180 | } | |
181 | ||
182 | static const struct file_operations cuse_frontend_fops = { | |
183 | .owner = THIS_MODULE, | |
cfa86a74 AV |
184 | .read_iter = cuse_read_iter, |
185 | .write_iter = cuse_write_iter, | |
151060ac TH |
186 | .open = cuse_open, |
187 | .release = cuse_release, | |
188 | .unlocked_ioctl = cuse_file_ioctl, | |
189 | .compat_ioctl = cuse_file_compat_ioctl, | |
190 | .poll = fuse_file_poll, | |
6038f373 | 191 | .llseek = noop_llseek, |
151060ac TH |
192 | }; |
193 | ||
194 | ||
195 | /************************************************************************** | |
196 | * CUSE channel initialization and destruction | |
197 | */ | |
198 | ||
199 | struct cuse_devinfo { | |
200 | const char *name; | |
201 | }; | |
202 | ||
203 | /** | |
204 | * cuse_parse_one - parse one key=value pair | |
205 | * @pp: i/o parameter for the current position | |
206 | * @end: points to one past the end of the packed string | |
207 | * @keyp: out parameter for key | |
208 | * @valp: out parameter for value | |
209 | * | |
210 | * *@pp points to packed strings - "key0=val0\0key1=val1\0" which ends | |
211 | * at @end - 1. This function parses one pair and set *@keyp to the | |
212 | * start of the key and *@valp to the start of the value. Note that | |
213 | * the original string is modified such that the key string is | |
214 | * terminated with '\0'. *@pp is updated to point to the next string. | |
215 | * | |
216 | * RETURNS: | |
217 | * 1 on successful parse, 0 on EOF, -errno on failure. | |
218 | */ | |
219 | static int cuse_parse_one(char **pp, char *end, char **keyp, char **valp) | |
220 | { | |
221 | char *p = *pp; | |
222 | char *key, *val; | |
223 | ||
224 | while (p < end && *p == '\0') | |
225 | p++; | |
226 | if (p == end) | |
227 | return 0; | |
228 | ||
229 | if (end[-1] != '\0') { | |
f2294482 | 230 | pr_err("info not properly terminated\n"); |
151060ac TH |
231 | return -EINVAL; |
232 | } | |
233 | ||
234 | key = val = p; | |
235 | p += strlen(p); | |
236 | ||
237 | if (valp) { | |
238 | strsep(&val, "="); | |
239 | if (!val) | |
240 | val = key + strlen(key); | |
241 | key = strstrip(key); | |
242 | val = strstrip(val); | |
243 | } else | |
244 | key = strstrip(key); | |
245 | ||
246 | if (!strlen(key)) { | |
f2294482 | 247 | pr_err("zero length info key specified\n"); |
151060ac TH |
248 | return -EINVAL; |
249 | } | |
250 | ||
251 | *pp = p; | |
252 | *keyp = key; | |
253 | if (valp) | |
254 | *valp = val; | |
255 | ||
256 | return 1; | |
257 | } | |
258 | ||
259 | /** | |
260 | * cuse_parse_dev_info - parse device info | |
261 | * @p: device info string | |
262 | * @len: length of device info string | |
263 | * @devinfo: out parameter for parsed device info | |
264 | * | |
265 | * Parse @p to extract device info and store it into @devinfo. String | |
266 | * pointed to by @p is modified by parsing and @devinfo points into | |
267 | * them, so @p shouldn't be freed while @devinfo is in use. | |
268 | * | |
269 | * RETURNS: | |
270 | * 0 on success, -errno on failure. | |
271 | */ | |
272 | static int cuse_parse_devinfo(char *p, size_t len, struct cuse_devinfo *devinfo) | |
273 | { | |
274 | char *end = p + len; | |
e2560362 | 275 | char *uninitialized_var(key), *uninitialized_var(val); |
151060ac TH |
276 | int rc; |
277 | ||
278 | while (true) { | |
279 | rc = cuse_parse_one(&p, end, &key, &val); | |
280 | if (rc < 0) | |
281 | return rc; | |
282 | if (!rc) | |
283 | break; | |
284 | if (strcmp(key, "DEVNAME") == 0) | |
285 | devinfo->name = val; | |
286 | else | |
f2294482 | 287 | pr_warn("unknown device info \"%s\"\n", key); |
151060ac TH |
288 | } |
289 | ||
290 | if (!devinfo->name || !strlen(devinfo->name)) { | |
f2294482 | 291 | pr_err("DEVNAME unspecified\n"); |
151060ac TH |
292 | return -EINVAL; |
293 | } | |
294 | ||
295 | return 0; | |
296 | } | |
297 | ||
298 | static void cuse_gendev_release(struct device *dev) | |
299 | { | |
300 | kfree(dev); | |
301 | } | |
302 | ||
303 | /** | |
304 | * cuse_process_init_reply - finish initializing CUSE channel | |
305 | * | |
306 | * This function creates the character device and sets up all the | |
307 | * required data structures for it. Please read the comment at the | |
308 | * top of this file for high level overview. | |
309 | */ | |
310 | static void cuse_process_init_reply(struct fuse_conn *fc, struct fuse_req *req) | |
311 | { | |
30783587 | 312 | struct cuse_conn *cc = fc_to_cc(fc), *pos; |
07d5f69b | 313 | struct cuse_init_out *arg = req->out.args[0].value; |
151060ac TH |
314 | struct page *page = req->pages[0]; |
315 | struct cuse_devinfo devinfo = { }; | |
316 | struct device *dev; | |
317 | struct cdev *cdev; | |
318 | dev_t devt; | |
30783587 | 319 | int rc, i; |
151060ac TH |
320 | |
321 | if (req->out.h.error || | |
322 | arg->major != FUSE_KERNEL_VERSION || arg->minor < 11) { | |
323 | goto err; | |
324 | } | |
325 | ||
326 | fc->minor = arg->minor; | |
327 | fc->max_read = max_t(unsigned, arg->max_read, 4096); | |
328 | fc->max_write = max_t(unsigned, arg->max_write, 4096); | |
329 | ||
330 | /* parse init reply */ | |
331 | cc->unrestricted_ioctl = arg->flags & CUSE_UNRESTRICTED_IOCTL; | |
332 | ||
333 | rc = cuse_parse_devinfo(page_address(page), req->out.args[1].size, | |
334 | &devinfo); | |
335 | if (rc) | |
336 | goto err; | |
337 | ||
338 | /* determine and reserve devt */ | |
339 | devt = MKDEV(arg->dev_major, arg->dev_minor); | |
340 | if (!MAJOR(devt)) | |
341 | rc = alloc_chrdev_region(&devt, MINOR(devt), 1, devinfo.name); | |
342 | else | |
343 | rc = register_chrdev_region(devt, 1, devinfo.name); | |
344 | if (rc) { | |
f2294482 | 345 | pr_err("failed to register chrdev region\n"); |
151060ac TH |
346 | goto err; |
347 | } | |
348 | ||
349 | /* devt determined, create device */ | |
350 | rc = -ENOMEM; | |
351 | dev = kzalloc(sizeof(*dev), GFP_KERNEL); | |
352 | if (!dev) | |
353 | goto err_region; | |
354 | ||
355 | device_initialize(dev); | |
356 | dev_set_uevent_suppress(dev, 1); | |
357 | dev->class = cuse_class; | |
358 | dev->devt = devt; | |
359 | dev->release = cuse_gendev_release; | |
360 | dev_set_drvdata(dev, cc); | |
361 | dev_set_name(dev, "%s", devinfo.name); | |
362 | ||
30783587 DH |
363 | mutex_lock(&cuse_lock); |
364 | ||
365 | /* make sure the device-name is unique */ | |
366 | for (i = 0; i < CUSE_CONNTBL_LEN; ++i) { | |
367 | list_for_each_entry(pos, &cuse_conntbl[i], list) | |
368 | if (!strcmp(dev_name(pos->dev), dev_name(dev))) | |
369 | goto err_unlock; | |
370 | } | |
371 | ||
151060ac TH |
372 | rc = device_add(dev); |
373 | if (rc) | |
30783587 | 374 | goto err_unlock; |
151060ac TH |
375 | |
376 | /* register cdev */ | |
377 | rc = -ENOMEM; | |
378 | cdev = cdev_alloc(); | |
379 | if (!cdev) | |
30783587 | 380 | goto err_unlock; |
151060ac TH |
381 | |
382 | cdev->owner = THIS_MODULE; | |
383 | cdev->ops = &cuse_frontend_fops; | |
384 | ||
385 | rc = cdev_add(cdev, devt, 1); | |
386 | if (rc) | |
387 | goto err_cdev; | |
388 | ||
389 | cc->dev = dev; | |
390 | cc->cdev = cdev; | |
391 | ||
392 | /* make the device available */ | |
151060ac | 393 | list_add(&cc->list, cuse_conntbl_head(devt)); |
8ce03fd7 | 394 | mutex_unlock(&cuse_lock); |
151060ac TH |
395 | |
396 | /* announce device availability */ | |
397 | dev_set_uevent_suppress(dev, 0); | |
398 | kobject_uevent(&dev->kobj, KOBJ_ADD); | |
399 | out: | |
07d5f69b | 400 | kfree(arg); |
151060ac TH |
401 | __free_page(page); |
402 | return; | |
403 | ||
404 | err_cdev: | |
405 | cdev_del(cdev); | |
30783587 DH |
406 | err_unlock: |
407 | mutex_unlock(&cuse_lock); | |
151060ac TH |
408 | put_device(dev); |
409 | err_region: | |
410 | unregister_chrdev_region(devt, 1); | |
411 | err: | |
eb98e3bd | 412 | fuse_abort_conn(fc); |
151060ac TH |
413 | goto out; |
414 | } | |
415 | ||
416 | static int cuse_send_init(struct cuse_conn *cc) | |
417 | { | |
418 | int rc; | |
419 | struct fuse_req *req; | |
420 | struct page *page; | |
421 | struct fuse_conn *fc = &cc->fc; | |
422 | struct cuse_init_in *arg; | |
07d5f69b | 423 | void *outarg; |
151060ac TH |
424 | |
425 | BUILD_BUG_ON(CUSE_INIT_INFO_MAX > PAGE_SIZE); | |
426 | ||
8b41e671 | 427 | req = fuse_get_req_for_background(fc, 1); |
151060ac TH |
428 | if (IS_ERR(req)) { |
429 | rc = PTR_ERR(req); | |
430 | goto err; | |
431 | } | |
432 | ||
433 | rc = -ENOMEM; | |
434 | page = alloc_page(GFP_KERNEL | __GFP_ZERO); | |
435 | if (!page) | |
436 | goto err_put_req; | |
437 | ||
07d5f69b MS |
438 | outarg = kzalloc(sizeof(struct cuse_init_out), GFP_KERNEL); |
439 | if (!outarg) | |
440 | goto err_free_page; | |
441 | ||
151060ac TH |
442 | arg = &req->misc.cuse_init_in; |
443 | arg->major = FUSE_KERNEL_VERSION; | |
444 | arg->minor = FUSE_KERNEL_MINOR_VERSION; | |
445 | arg->flags |= CUSE_UNRESTRICTED_IOCTL; | |
446 | req->in.h.opcode = CUSE_INIT; | |
447 | req->in.numargs = 1; | |
448 | req->in.args[0].size = sizeof(struct cuse_init_in); | |
449 | req->in.args[0].value = arg; | |
450 | req->out.numargs = 2; | |
451 | req->out.args[0].size = sizeof(struct cuse_init_out); | |
07d5f69b | 452 | req->out.args[0].value = outarg; |
151060ac TH |
453 | req->out.args[1].size = CUSE_INIT_INFO_MAX; |
454 | req->out.argvar = 1; | |
455 | req->out.argpages = 1; | |
456 | req->pages[0] = page; | |
85f40aec | 457 | req->page_descs[0].length = req->out.args[1].size; |
151060ac TH |
458 | req->num_pages = 1; |
459 | req->end = cuse_process_init_reply; | |
460 | fuse_request_send_background(fc, req); | |
461 | ||
462 | return 0; | |
463 | ||
07d5f69b MS |
464 | err_free_page: |
465 | __free_page(page); | |
151060ac TH |
466 | err_put_req: |
467 | fuse_put_request(fc, req); | |
468 | err: | |
469 | return rc; | |
470 | } | |
471 | ||
472 | static void cuse_fc_release(struct fuse_conn *fc) | |
473 | { | |
474 | struct cuse_conn *cc = fc_to_cc(fc); | |
dd3e2c55 | 475 | kfree_rcu(cc, fc.rcu); |
151060ac TH |
476 | } |
477 | ||
478 | /** | |
479 | * cuse_channel_open - open method for /dev/cuse | |
480 | * @inode: inode for /dev/cuse | |
481 | * @file: file struct being opened | |
482 | * | |
483 | * Userland CUSE server can create a CUSE device by opening /dev/cuse | |
8272f4c9 | 484 | * and replying to the initialization request kernel sends. This |
151060ac TH |
485 | * function is responsible for handling CUSE device initialization. |
486 | * Because the fd opened by this function is used during | |
487 | * initialization, this function only creates cuse_conn and sends | |
488 | * init. The rest is delegated to a kthread. | |
489 | * | |
490 | * RETURNS: | |
491 | * 0 on success, -errno on failure. | |
492 | */ | |
493 | static int cuse_channel_open(struct inode *inode, struct file *file) | |
494 | { | |
cc080e9e | 495 | struct fuse_dev *fud; |
151060ac TH |
496 | struct cuse_conn *cc; |
497 | int rc; | |
498 | ||
499 | /* set up cuse_conn */ | |
500 | cc = kzalloc(sizeof(*cc), GFP_KERNEL); | |
501 | if (!cc) | |
502 | return -ENOMEM; | |
503 | ||
8cb08329 EB |
504 | /* |
505 | * Limit the cuse channel to requests that can | |
506 | * be represented in file->f_cred->user_ns. | |
507 | */ | |
508 | fuse_conn_init(&cc->fc, file->f_cred->user_ns); | |
151060ac | 509 | |
cc080e9e MS |
510 | fud = fuse_dev_alloc(&cc->fc); |
511 | if (!fud) { | |
512 | kfree(cc); | |
513 | return -ENOMEM; | |
514 | } | |
515 | ||
151060ac TH |
516 | INIT_LIST_HEAD(&cc->list); |
517 | cc->fc.release = cuse_fc_release; | |
518 | ||
796523fb | 519 | cc->fc.initialized = 1; |
151060ac TH |
520 | rc = cuse_send_init(cc); |
521 | if (rc) { | |
cc080e9e | 522 | fuse_dev_free(fud); |
151060ac TH |
523 | return rc; |
524 | } | |
cc080e9e | 525 | file->private_data = fud; |
151060ac TH |
526 | |
527 | return 0; | |
528 | } | |
529 | ||
530 | /** | |
531 | * cuse_channel_release - release method for /dev/cuse | |
532 | * @inode: inode for /dev/cuse | |
533 | * @file: file struct being closed | |
534 | * | |
535 | * Disconnect the channel, deregister CUSE device and initiate | |
536 | * destruction by putting the default reference. | |
537 | * | |
538 | * RETURNS: | |
539 | * 0 on success, -errno on failure. | |
540 | */ | |
541 | static int cuse_channel_release(struct inode *inode, struct file *file) | |
542 | { | |
cc080e9e MS |
543 | struct fuse_dev *fud = file->private_data; |
544 | struct cuse_conn *cc = fc_to_cc(fud->fc); | |
151060ac TH |
545 | int rc; |
546 | ||
547 | /* remove from the conntbl, no more access from this point on */ | |
8ce03fd7 | 548 | mutex_lock(&cuse_lock); |
151060ac | 549 | list_del_init(&cc->list); |
8ce03fd7 | 550 | mutex_unlock(&cuse_lock); |
151060ac TH |
551 | |
552 | /* remove device */ | |
553 | if (cc->dev) | |
554 | device_unregister(cc->dev); | |
555 | if (cc->cdev) { | |
556 | unregister_chrdev_region(cc->cdev->dev, 1); | |
557 | cdev_del(cc->cdev); | |
558 | } | |
2c5816b4 MS |
559 | /* Base reference is now owned by "fud" */ |
560 | fuse_conn_put(&cc->fc); | |
151060ac | 561 | |
151060ac TH |
562 | rc = fuse_dev_release(inode, file); /* puts the base reference */ |
563 | ||
564 | return rc; | |
565 | } | |
566 | ||
567 | static struct file_operations cuse_channel_fops; /* initialized during init */ | |
568 | ||
569 | ||
570 | /************************************************************************** | |
571 | * Misc stuff and module initializatiion | |
572 | * | |
573 | * CUSE exports the same set of attributes to sysfs as fusectl. | |
574 | */ | |
575 | ||
576 | static ssize_t cuse_class_waiting_show(struct device *dev, | |
577 | struct device_attribute *attr, char *buf) | |
578 | { | |
579 | struct cuse_conn *cc = dev_get_drvdata(dev); | |
580 | ||
581 | return sprintf(buf, "%d\n", atomic_read(&cc->fc.num_waiting)); | |
582 | } | |
58f86cc8 | 583 | static DEVICE_ATTR(waiting, 0400, cuse_class_waiting_show, NULL); |
151060ac TH |
584 | |
585 | static ssize_t cuse_class_abort_store(struct device *dev, | |
586 | struct device_attribute *attr, | |
587 | const char *buf, size_t count) | |
588 | { | |
589 | struct cuse_conn *cc = dev_get_drvdata(dev); | |
590 | ||
eb98e3bd | 591 | fuse_abort_conn(&cc->fc); |
151060ac TH |
592 | return count; |
593 | } | |
58f86cc8 | 594 | static DEVICE_ATTR(abort, 0200, NULL, cuse_class_abort_store); |
151060ac | 595 | |
4183fb95 GKH |
596 | static struct attribute *cuse_class_dev_attrs[] = { |
597 | &dev_attr_waiting.attr, | |
598 | &dev_attr_abort.attr, | |
599 | NULL, | |
151060ac | 600 | }; |
4183fb95 | 601 | ATTRIBUTE_GROUPS(cuse_class_dev); |
151060ac TH |
602 | |
603 | static struct miscdevice cuse_miscdev = { | |
cb2ffb26 | 604 | .minor = CUSE_MINOR, |
151060ac TH |
605 | .name = "cuse", |
606 | .fops = &cuse_channel_fops, | |
607 | }; | |
608 | ||
cb2ffb26 TG |
609 | MODULE_ALIAS_MISCDEV(CUSE_MINOR); |
610 | MODULE_ALIAS("devname:cuse"); | |
611 | ||
151060ac TH |
612 | static int __init cuse_init(void) |
613 | { | |
614 | int i, rc; | |
615 | ||
616 | /* init conntbl */ | |
617 | for (i = 0; i < CUSE_CONNTBL_LEN; i++) | |
618 | INIT_LIST_HEAD(&cuse_conntbl[i]); | |
619 | ||
620 | /* inherit and extend fuse_dev_operations */ | |
621 | cuse_channel_fops = fuse_dev_operations; | |
622 | cuse_channel_fops.owner = THIS_MODULE; | |
623 | cuse_channel_fops.open = cuse_channel_open; | |
624 | cuse_channel_fops.release = cuse_channel_release; | |
625 | ||
626 | cuse_class = class_create(THIS_MODULE, "cuse"); | |
627 | if (IS_ERR(cuse_class)) | |
628 | return PTR_ERR(cuse_class); | |
629 | ||
4183fb95 | 630 | cuse_class->dev_groups = cuse_class_dev_groups; |
151060ac TH |
631 | |
632 | rc = misc_register(&cuse_miscdev); | |
633 | if (rc) { | |
634 | class_destroy(cuse_class); | |
635 | return rc; | |
636 | } | |
637 | ||
638 | return 0; | |
639 | } | |
640 | ||
641 | static void __exit cuse_exit(void) | |
642 | { | |
643 | misc_deregister(&cuse_miscdev); | |
644 | class_destroy(cuse_class); | |
645 | } | |
646 | ||
647 | module_init(cuse_init); | |
648 | module_exit(cuse_exit); | |
649 | ||
650 | MODULE_AUTHOR("Tejun Heo <tj@kernel.org>"); | |
651 | MODULE_DESCRIPTION("Character device in Userspace"); | |
652 | MODULE_LICENSE("GPL"); |