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Miklos Szeredi334f4852005-09-09 13:10:27 -07001/*
2 FUSE: Filesystem in Userspace
Miklos Szeredi1729a162008-11-26 12:03:54 +01003 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
Miklos Szeredi334f4852005-09-09 13:10:27 -07004
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7*/
8
9#include "fuse_i.h"
10
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/poll.h>
14#include <linux/uio.h>
15#include <linux/miscdevice.h>
16#include <linux/pagemap.h>
17#include <linux/file.h>
18#include <linux/slab.h>
19
20MODULE_ALIAS_MISCDEV(FUSE_MINOR);
21
Christoph Lametere18b8902006-12-06 20:33:20 -080022static struct kmem_cache *fuse_req_cachep;
Miklos Szeredi334f4852005-09-09 13:10:27 -070023
Miklos Szeredi8bfc0162006-01-16 22:14:28 -080024static struct fuse_conn *fuse_get_conn(struct file *file)
Miklos Szeredi334f4852005-09-09 13:10:27 -070025{
Miklos Szeredi0720b312006-04-10 22:54:55 -070026 /*
27 * Lockless access is OK, because file->private data is set
28 * once during mount and is valid until the file is released.
29 */
30 return file->private_data;
Miklos Szeredi334f4852005-09-09 13:10:27 -070031}
32
Miklos Szeredi8bfc0162006-01-16 22:14:28 -080033static void fuse_request_init(struct fuse_req *req)
Miklos Szeredi334f4852005-09-09 13:10:27 -070034{
35 memset(req, 0, sizeof(*req));
36 INIT_LIST_HEAD(&req->list);
Miklos Szeredia4d27e72006-06-25 05:48:54 -070037 INIT_LIST_HEAD(&req->intr_entry);
Miklos Szeredi334f4852005-09-09 13:10:27 -070038 init_waitqueue_head(&req->waitq);
39 atomic_set(&req->count, 1);
40}
41
42struct fuse_req *fuse_request_alloc(void)
43{
Christoph Lametere94b1762006-12-06 20:33:17 -080044 struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_KERNEL);
Miklos Szeredi334f4852005-09-09 13:10:27 -070045 if (req)
46 fuse_request_init(req);
47 return req;
48}
49
Miklos Szeredi3be5a522008-04-30 00:54:41 -070050struct fuse_req *fuse_request_alloc_nofs(void)
51{
52 struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_NOFS);
53 if (req)
54 fuse_request_init(req);
55 return req;
56}
57
Miklos Szeredi334f4852005-09-09 13:10:27 -070058void fuse_request_free(struct fuse_req *req)
59{
60 kmem_cache_free(fuse_req_cachep, req);
61}
62
Miklos Szeredi8bfc0162006-01-16 22:14:28 -080063static void block_sigs(sigset_t *oldset)
Miklos Szeredi334f4852005-09-09 13:10:27 -070064{
65 sigset_t mask;
66
67 siginitsetinv(&mask, sigmask(SIGKILL));
68 sigprocmask(SIG_BLOCK, &mask, oldset);
69}
70
Miklos Szeredi8bfc0162006-01-16 22:14:28 -080071static void restore_sigs(sigset_t *oldset)
Miklos Szeredi334f4852005-09-09 13:10:27 -070072{
73 sigprocmask(SIG_SETMASK, oldset, NULL);
74}
75
Miklos Szeredi334f4852005-09-09 13:10:27 -070076static void __fuse_get_request(struct fuse_req *req)
77{
78 atomic_inc(&req->count);
79}
80
81/* Must be called with > 1 refcount */
82static void __fuse_put_request(struct fuse_req *req)
83{
84 BUG_ON(atomic_read(&req->count) < 2);
85 atomic_dec(&req->count);
86}
87
Miklos Szeredi33649c92006-06-25 05:48:52 -070088static void fuse_req_init_context(struct fuse_req *req)
89{
90 req->in.h.uid = current->fsuid;
91 req->in.h.gid = current->fsgid;
92 req->in.h.pid = current->pid;
93}
94
Miklos Szeredice1d5a42006-04-10 22:54:58 -070095struct fuse_req *fuse_get_req(struct fuse_conn *fc)
Miklos Szeredi334f4852005-09-09 13:10:27 -070096{
Miklos Szeredi08a53cd2006-04-10 22:54:59 -070097 struct fuse_req *req;
98 sigset_t oldset;
Miklos Szeredi9bc5ddd2006-04-11 21:16:09 +020099 int intr;
Miklos Szeredi08a53cd2006-04-10 22:54:59 -0700100 int err;
101
Miklos Szeredi9bc5ddd2006-04-11 21:16:09 +0200102 atomic_inc(&fc->num_waiting);
Miklos Szeredi08a53cd2006-04-10 22:54:59 -0700103 block_sigs(&oldset);
Miklos Szeredi9bc5ddd2006-04-11 21:16:09 +0200104 intr = wait_event_interruptible(fc->blocked_waitq, !fc->blocked);
Miklos Szeredi08a53cd2006-04-10 22:54:59 -0700105 restore_sigs(&oldset);
Miklos Szeredi9bc5ddd2006-04-11 21:16:09 +0200106 err = -EINTR;
107 if (intr)
108 goto out;
Miklos Szeredi08a53cd2006-04-10 22:54:59 -0700109
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700110 err = -ENOTCONN;
111 if (!fc->connected)
112 goto out;
113
Miklos Szeredi08a53cd2006-04-10 22:54:59 -0700114 req = fuse_request_alloc();
Miklos Szeredi9bc5ddd2006-04-11 21:16:09 +0200115 err = -ENOMEM;
Miklos Szeredice1d5a42006-04-10 22:54:58 -0700116 if (!req)
Miklos Szeredi9bc5ddd2006-04-11 21:16:09 +0200117 goto out;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700118
Miklos Szeredi33649c92006-06-25 05:48:52 -0700119 fuse_req_init_context(req);
Miklos Szeredi9bc5ddd2006-04-11 21:16:09 +0200120 req->waiting = 1;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700121 return req;
Miklos Szeredi9bc5ddd2006-04-11 21:16:09 +0200122
123 out:
124 atomic_dec(&fc->num_waiting);
125 return ERR_PTR(err);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700126}
127
Miklos Szeredi33649c92006-06-25 05:48:52 -0700128/*
129 * Return request in fuse_file->reserved_req. However that may
130 * currently be in use. If that is the case, wait for it to become
131 * available.
132 */
133static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
134 struct file *file)
135{
136 struct fuse_req *req = NULL;
137 struct fuse_file *ff = file->private_data;
138
139 do {
Miklos Szeredide5e3de2007-10-16 23:31:00 -0700140 wait_event(fc->reserved_req_waitq, ff->reserved_req);
Miklos Szeredi33649c92006-06-25 05:48:52 -0700141 spin_lock(&fc->lock);
142 if (ff->reserved_req) {
143 req = ff->reserved_req;
144 ff->reserved_req = NULL;
145 get_file(file);
146 req->stolen_file = file;
147 }
148 spin_unlock(&fc->lock);
149 } while (!req);
150
151 return req;
152}
153
154/*
155 * Put stolen request back into fuse_file->reserved_req
156 */
157static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
158{
159 struct file *file = req->stolen_file;
160 struct fuse_file *ff = file->private_data;
161
162 spin_lock(&fc->lock);
163 fuse_request_init(req);
164 BUG_ON(ff->reserved_req);
165 ff->reserved_req = req;
Miklos Szeredide5e3de2007-10-16 23:31:00 -0700166 wake_up_all(&fc->reserved_req_waitq);
Miklos Szeredi33649c92006-06-25 05:48:52 -0700167 spin_unlock(&fc->lock);
168 fput(file);
169}
170
171/*
172 * Gets a requests for a file operation, always succeeds
173 *
174 * This is used for sending the FLUSH request, which must get to
175 * userspace, due to POSIX locks which may need to be unlocked.
176 *
177 * If allocation fails due to OOM, use the reserved request in
178 * fuse_file.
179 *
180 * This is very unlikely to deadlock accidentally, since the
181 * filesystem should not have it's own file open. If deadlock is
182 * intentional, it can still be broken by "aborting" the filesystem.
183 */
184struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file)
185{
186 struct fuse_req *req;
187
188 atomic_inc(&fc->num_waiting);
189 wait_event(fc->blocked_waitq, !fc->blocked);
190 req = fuse_request_alloc();
191 if (!req)
192 req = get_reserved_req(fc, file);
193
194 fuse_req_init_context(req);
195 req->waiting = 1;
196 return req;
197}
198
Miklos Szeredi334f4852005-09-09 13:10:27 -0700199void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
200{
Miklos Szeredi7128ec22006-02-04 23:27:40 -0800201 if (atomic_dec_and_test(&req->count)) {
Miklos Szeredi9bc5ddd2006-04-11 21:16:09 +0200202 if (req->waiting)
203 atomic_dec(&fc->num_waiting);
Miklos Szeredi33649c92006-06-25 05:48:52 -0700204
205 if (req->stolen_file)
206 put_reserved_req(fc, req);
207 else
208 fuse_request_free(req);
Miklos Szeredi7128ec22006-02-04 23:27:40 -0800209 }
210}
211
Miklos Szeredid12def12008-02-06 01:38:39 -0800212static unsigned len_args(unsigned numargs, struct fuse_arg *args)
213{
214 unsigned nbytes = 0;
215 unsigned i;
216
217 for (i = 0; i < numargs; i++)
218 nbytes += args[i].size;
219
220 return nbytes;
221}
222
223static u64 fuse_get_unique(struct fuse_conn *fc)
224{
225 fc->reqctr++;
226 /* zero is special */
227 if (fc->reqctr == 0)
228 fc->reqctr = 1;
229
230 return fc->reqctr;
231}
232
233static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
234{
235 req->in.h.unique = fuse_get_unique(fc);
236 req->in.h.len = sizeof(struct fuse_in_header) +
237 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
238 list_add_tail(&req->list, &fc->pending);
239 req->state = FUSE_REQ_PENDING;
240 if (!req->waiting) {
241 req->waiting = 1;
242 atomic_inc(&fc->num_waiting);
243 }
244 wake_up(&fc->waitq);
245 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
246}
247
248static void flush_bg_queue(struct fuse_conn *fc)
249{
250 while (fc->active_background < FUSE_MAX_BACKGROUND &&
251 !list_empty(&fc->bg_queue)) {
252 struct fuse_req *req;
253
254 req = list_entry(fc->bg_queue.next, struct fuse_req, list);
255 list_del(&req->list);
256 fc->active_background++;
257 queue_request(fc, req);
258 }
259}
260
Miklos Szeredi6dbbcb12006-04-26 10:49:06 +0200261/*
Miklos Szeredi334f4852005-09-09 13:10:27 -0700262 * This function is called when a request is finished. Either a reply
Miklos Szeredif9a28422006-06-25 05:48:53 -0700263 * has arrived or it was aborted (and not yet sent) or some error
Miklos Szeredif43b1552006-01-16 22:14:26 -0800264 * occurred during communication with userspace, or the device file
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700265 * was closed. The requester thread is woken up (if still waiting),
266 * the 'end' callback is called if given, else the reference to the
267 * request is released
Miklos Szeredi7128ec22006-02-04 23:27:40 -0800268 *
Miklos Szeredid7133112006-04-10 22:54:55 -0700269 * Called with fc->lock, unlocks it
Miklos Szeredi334f4852005-09-09 13:10:27 -0700270 */
271static void request_end(struct fuse_conn *fc, struct fuse_req *req)
Josh Triplett105f4d72006-09-29 01:59:25 -0700272 __releases(fc->lock)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700273{
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700274 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
275 req->end = NULL;
Miklos Szeredid77a1d52006-01-16 22:14:31 -0800276 list_del(&req->list);
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700277 list_del(&req->intr_entry);
Miklos Szeredi83cfd492006-01-16 22:14:31 -0800278 req->state = FUSE_REQ_FINISHED;
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700279 if (req->background) {
280 if (fc->num_background == FUSE_MAX_BACKGROUND) {
281 fc->blocked = 0;
282 wake_up_all(&fc->blocked_waitq);
283 }
Miklos Szeredif92b99b2007-10-16 23:30:59 -0700284 if (fc->num_background == FUSE_CONGESTION_THRESHOLD) {
285 clear_bdi_congested(&fc->bdi, READ);
286 clear_bdi_congested(&fc->bdi, WRITE);
287 }
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700288 fc->num_background--;
Miklos Szeredid12def12008-02-06 01:38:39 -0800289 fc->active_background--;
290 flush_bg_queue(fc);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700291 }
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700292 spin_unlock(&fc->lock);
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700293 wake_up(&req->waitq);
294 if (end)
295 end(fc, req);
Tejun Heoe9bb09d2008-11-26 12:03:54 +0100296 fuse_put_request(fc, req);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700297}
298
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700299static void wait_answer_interruptible(struct fuse_conn *fc,
300 struct fuse_req *req)
Miklos Szeredi4dbf9302008-04-30 00:54:45 -0700301 __releases(fc->lock) __acquires(fc->lock)
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700302{
303 if (signal_pending(current))
304 return;
305
306 spin_unlock(&fc->lock);
307 wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
308 spin_lock(&fc->lock);
309}
310
311static void queue_interrupt(struct fuse_conn *fc, struct fuse_req *req)
312{
313 list_add_tail(&req->intr_entry, &fc->interrupts);
314 wake_up(&fc->waitq);
315 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
316}
317
Miklos Szeredi7c352bd2005-09-09 13:10:39 -0700318static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
Miklos Szeredi4dbf9302008-04-30 00:54:45 -0700319 __releases(fc->lock) __acquires(fc->lock)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700320{
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700321 if (!fc->no_interrupt) {
322 /* Any signal may interrupt this */
323 wait_answer_interruptible(fc, req);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700324
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700325 if (req->aborted)
326 goto aborted;
327 if (req->state == FUSE_REQ_FINISHED)
328 return;
329
330 req->interrupted = 1;
331 if (req->state == FUSE_REQ_SENT)
332 queue_interrupt(fc, req);
333 }
334
Miklos Szeredia131de02007-10-16 23:31:04 -0700335 if (!req->force) {
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700336 sigset_t oldset;
337
338 /* Only fatal signals may interrupt this */
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700339 block_sigs(&oldset);
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700340 wait_answer_interruptible(fc, req);
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700341 restore_sigs(&oldset);
Miklos Szeredia131de02007-10-16 23:31:04 -0700342
343 if (req->aborted)
344 goto aborted;
345 if (req->state == FUSE_REQ_FINISHED)
346 return;
347
348 /* Request is not yet in userspace, bail out */
349 if (req->state == FUSE_REQ_PENDING) {
350 list_del(&req->list);
351 __fuse_put_request(req);
352 req->out.h.error = -EINTR;
353 return;
354 }
Miklos Szeredi51eb01e2006-06-25 05:48:50 -0700355 }
Miklos Szeredi334f4852005-09-09 13:10:27 -0700356
Miklos Szeredia131de02007-10-16 23:31:04 -0700357 /*
358 * Either request is already in userspace, or it was forced.
359 * Wait it out.
360 */
361 spin_unlock(&fc->lock);
362 wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
363 spin_lock(&fc->lock);
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700364
Miklos Szeredia131de02007-10-16 23:31:04 -0700365 if (!req->aborted)
366 return;
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700367
368 aborted:
Miklos Szeredia131de02007-10-16 23:31:04 -0700369 BUG_ON(req->state != FUSE_REQ_FINISHED);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700370 if (req->locked) {
371 /* This is uninterruptible sleep, because data is
372 being copied to/from the buffers of req. During
373 locked state, there mustn't be any filesystem
374 operation (e.g. page fault), since that could lead
375 to deadlock */
Miklos Szeredid7133112006-04-10 22:54:55 -0700376 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700377 wait_event(req->waitq, !req->locked);
Miklos Szeredid7133112006-04-10 22:54:55 -0700378 spin_lock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700379 }
Miklos Szeredi334f4852005-09-09 13:10:27 -0700380}
381
Miklos Szeredi7c352bd2005-09-09 13:10:39 -0700382void request_send(struct fuse_conn *fc, struct fuse_req *req)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700383{
384 req->isreply = 1;
Miklos Szeredid7133112006-04-10 22:54:55 -0700385 spin_lock(&fc->lock);
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700386 if (!fc->connected)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700387 req->out.h.error = -ENOTCONN;
388 else if (fc->conn_error)
389 req->out.h.error = -ECONNREFUSED;
390 else {
391 queue_request(fc, req);
392 /* acquire extra reference, since request is still needed
393 after request_end() */
394 __fuse_get_request(req);
395
Miklos Szeredi7c352bd2005-09-09 13:10:39 -0700396 request_wait_answer(fc, req);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700397 }
Miklos Szeredid7133112006-04-10 22:54:55 -0700398 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700399}
400
Miklos Szeredid12def12008-02-06 01:38:39 -0800401static void request_send_nowait_locked(struct fuse_conn *fc,
402 struct fuse_req *req)
403{
404 req->background = 1;
405 fc->num_background++;
406 if (fc->num_background == FUSE_MAX_BACKGROUND)
407 fc->blocked = 1;
408 if (fc->num_background == FUSE_CONGESTION_THRESHOLD) {
409 set_bdi_congested(&fc->bdi, READ);
410 set_bdi_congested(&fc->bdi, WRITE);
411 }
412 list_add_tail(&req->list, &fc->bg_queue);
413 flush_bg_queue(fc);
414}
415
Miklos Szeredi334f4852005-09-09 13:10:27 -0700416static void request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
417{
Miklos Szeredid7133112006-04-10 22:54:55 -0700418 spin_lock(&fc->lock);
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700419 if (fc->connected) {
Miklos Szeredid12def12008-02-06 01:38:39 -0800420 request_send_nowait_locked(fc, req);
Miklos Szeredid7133112006-04-10 22:54:55 -0700421 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700422 } else {
423 req->out.h.error = -ENOTCONN;
424 request_end(fc, req);
425 }
426}
427
428void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req)
429{
430 req->isreply = 0;
431 request_send_nowait(fc, req);
432}
433
434void request_send_background(struct fuse_conn *fc, struct fuse_req *req)
435{
436 req->isreply = 1;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700437 request_send_nowait(fc, req);
438}
439
Miklos Szeredi334f4852005-09-09 13:10:27 -0700440/*
Miklos Szeredi3be5a522008-04-30 00:54:41 -0700441 * Called under fc->lock
442 *
443 * fc->connected must have been checked previously
444 */
445void request_send_background_locked(struct fuse_conn *fc, struct fuse_req *req)
446{
447 req->isreply = 1;
448 request_send_nowait_locked(fc, req);
449}
450
451/*
Miklos Szeredi334f4852005-09-09 13:10:27 -0700452 * Lock the request. Up to the next unlock_request() there mustn't be
453 * anything that could cause a page-fault. If the request was already
Miklos Szeredif9a28422006-06-25 05:48:53 -0700454 * aborted bail out.
Miklos Szeredi334f4852005-09-09 13:10:27 -0700455 */
Miklos Szeredid7133112006-04-10 22:54:55 -0700456static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700457{
458 int err = 0;
459 if (req) {
Miklos Szeredid7133112006-04-10 22:54:55 -0700460 spin_lock(&fc->lock);
Miklos Szeredif9a28422006-06-25 05:48:53 -0700461 if (req->aborted)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700462 err = -ENOENT;
463 else
464 req->locked = 1;
Miklos Szeredid7133112006-04-10 22:54:55 -0700465 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700466 }
467 return err;
468}
469
470/*
Miklos Szeredif9a28422006-06-25 05:48:53 -0700471 * Unlock request. If it was aborted during being locked, the
Miklos Szeredi334f4852005-09-09 13:10:27 -0700472 * requester thread is currently waiting for it to be unlocked, so
473 * wake it up.
474 */
Miklos Szeredid7133112006-04-10 22:54:55 -0700475static void unlock_request(struct fuse_conn *fc, struct fuse_req *req)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700476{
477 if (req) {
Miklos Szeredid7133112006-04-10 22:54:55 -0700478 spin_lock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700479 req->locked = 0;
Miklos Szeredif9a28422006-06-25 05:48:53 -0700480 if (req->aborted)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700481 wake_up(&req->waitq);
Miklos Szeredid7133112006-04-10 22:54:55 -0700482 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700483 }
484}
485
486struct fuse_copy_state {
Miklos Szeredid7133112006-04-10 22:54:55 -0700487 struct fuse_conn *fc;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700488 int write;
489 struct fuse_req *req;
490 const struct iovec *iov;
491 unsigned long nr_segs;
492 unsigned long seglen;
493 unsigned long addr;
494 struct page *pg;
495 void *mapaddr;
496 void *buf;
497 unsigned len;
498};
499
Miklos Szeredid7133112006-04-10 22:54:55 -0700500static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
501 int write, struct fuse_req *req,
502 const struct iovec *iov, unsigned long nr_segs)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700503{
504 memset(cs, 0, sizeof(*cs));
Miklos Szeredid7133112006-04-10 22:54:55 -0700505 cs->fc = fc;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700506 cs->write = write;
507 cs->req = req;
508 cs->iov = iov;
509 cs->nr_segs = nr_segs;
510}
511
512/* Unmap and put previous page of userspace buffer */
Miklos Szeredi8bfc0162006-01-16 22:14:28 -0800513static void fuse_copy_finish(struct fuse_copy_state *cs)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700514{
515 if (cs->mapaddr) {
516 kunmap_atomic(cs->mapaddr, KM_USER0);
517 if (cs->write) {
518 flush_dcache_page(cs->pg);
519 set_page_dirty_lock(cs->pg);
520 }
521 put_page(cs->pg);
522 cs->mapaddr = NULL;
523 }
524}
525
526/*
527 * Get another pagefull of userspace buffer, and map it to kernel
528 * address space, and lock request
529 */
530static int fuse_copy_fill(struct fuse_copy_state *cs)
531{
532 unsigned long offset;
533 int err;
534
Miklos Szeredid7133112006-04-10 22:54:55 -0700535 unlock_request(cs->fc, cs->req);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700536 fuse_copy_finish(cs);
537 if (!cs->seglen) {
538 BUG_ON(!cs->nr_segs);
539 cs->seglen = cs->iov[0].iov_len;
540 cs->addr = (unsigned long) cs->iov[0].iov_base;
Miklos Szeredi1729a162008-11-26 12:03:54 +0100541 cs->iov++;
542 cs->nr_segs--;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700543 }
544 down_read(&current->mm->mmap_sem);
545 err = get_user_pages(current, current->mm, cs->addr, 1, cs->write, 0,
546 &cs->pg, NULL);
547 up_read(&current->mm->mmap_sem);
548 if (err < 0)
549 return err;
550 BUG_ON(err != 1);
551 offset = cs->addr % PAGE_SIZE;
552 cs->mapaddr = kmap_atomic(cs->pg, KM_USER0);
553 cs->buf = cs->mapaddr + offset;
554 cs->len = min(PAGE_SIZE - offset, cs->seglen);
555 cs->seglen -= cs->len;
556 cs->addr += cs->len;
557
Miklos Szeredid7133112006-04-10 22:54:55 -0700558 return lock_request(cs->fc, cs->req);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700559}
560
561/* Do as much copy to/from userspace buffer as we can */
Miklos Szeredi8bfc0162006-01-16 22:14:28 -0800562static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700563{
564 unsigned ncpy = min(*size, cs->len);
565 if (val) {
566 if (cs->write)
567 memcpy(cs->buf, *val, ncpy);
568 else
569 memcpy(*val, cs->buf, ncpy);
570 *val += ncpy;
571 }
572 *size -= ncpy;
573 cs->len -= ncpy;
574 cs->buf += ncpy;
575 return ncpy;
576}
577
578/*
579 * Copy a page in the request to/from the userspace buffer. Must be
580 * done atomically
581 */
Miklos Szeredi8bfc0162006-01-16 22:14:28 -0800582static int fuse_copy_page(struct fuse_copy_state *cs, struct page *page,
583 unsigned offset, unsigned count, int zeroing)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700584{
585 if (page && zeroing && count < PAGE_SIZE) {
586 void *mapaddr = kmap_atomic(page, KM_USER1);
587 memset(mapaddr, 0, PAGE_SIZE);
588 kunmap_atomic(mapaddr, KM_USER1);
589 }
590 while (count) {
Miklos Szeredi1729a162008-11-26 12:03:54 +0100591 if (!cs->len) {
592 int err = fuse_copy_fill(cs);
593 if (err)
594 return err;
595 }
Miklos Szeredi334f4852005-09-09 13:10:27 -0700596 if (page) {
597 void *mapaddr = kmap_atomic(page, KM_USER1);
598 void *buf = mapaddr + offset;
599 offset += fuse_copy_do(cs, &buf, &count);
600 kunmap_atomic(mapaddr, KM_USER1);
601 } else
602 offset += fuse_copy_do(cs, NULL, &count);
603 }
604 if (page && !cs->write)
605 flush_dcache_page(page);
606 return 0;
607}
608
609/* Copy pages in the request to/from userspace buffer */
610static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
611 int zeroing)
612{
613 unsigned i;
614 struct fuse_req *req = cs->req;
615 unsigned offset = req->page_offset;
616 unsigned count = min(nbytes, (unsigned) PAGE_SIZE - offset);
617
618 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
619 struct page *page = req->pages[i];
620 int err = fuse_copy_page(cs, page, offset, count, zeroing);
621 if (err)
622 return err;
623
624 nbytes -= count;
625 count = min(nbytes, (unsigned) PAGE_SIZE);
626 offset = 0;
627 }
628 return 0;
629}
630
631/* Copy a single argument in the request to/from userspace buffer */
632static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
633{
634 while (size) {
Miklos Szeredi1729a162008-11-26 12:03:54 +0100635 if (!cs->len) {
636 int err = fuse_copy_fill(cs);
637 if (err)
638 return err;
639 }
Miklos Szeredi334f4852005-09-09 13:10:27 -0700640 fuse_copy_do(cs, &val, &size);
641 }
642 return 0;
643}
644
645/* Copy request arguments to/from userspace buffer */
646static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
647 unsigned argpages, struct fuse_arg *args,
648 int zeroing)
649{
650 int err = 0;
651 unsigned i;
652
653 for (i = 0; !err && i < numargs; i++) {
654 struct fuse_arg *arg = &args[i];
655 if (i == numargs - 1 && argpages)
656 err = fuse_copy_pages(cs, arg->size, zeroing);
657 else
658 err = fuse_copy_one(cs, arg->value, arg->size);
659 }
660 return err;
661}
662
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700663static int request_pending(struct fuse_conn *fc)
664{
665 return !list_empty(&fc->pending) || !list_empty(&fc->interrupts);
666}
667
Miklos Szeredi334f4852005-09-09 13:10:27 -0700668/* Wait until a request is available on the pending list */
669static void request_wait(struct fuse_conn *fc)
670{
671 DECLARE_WAITQUEUE(wait, current);
672
673 add_wait_queue_exclusive(&fc->waitq, &wait);
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700674 while (fc->connected && !request_pending(fc)) {
Miklos Szeredi334f4852005-09-09 13:10:27 -0700675 set_current_state(TASK_INTERRUPTIBLE);
676 if (signal_pending(current))
677 break;
678
Miklos Szeredid7133112006-04-10 22:54:55 -0700679 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700680 schedule();
Miklos Szeredid7133112006-04-10 22:54:55 -0700681 spin_lock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700682 }
683 set_current_state(TASK_RUNNING);
684 remove_wait_queue(&fc->waitq, &wait);
685}
686
687/*
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700688 * Transfer an interrupt request to userspace
689 *
690 * Unlike other requests this is assembled on demand, without a need
691 * to allocate a separate fuse_req structure.
692 *
693 * Called with fc->lock held, releases it
694 */
695static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_req *req,
696 const struct iovec *iov, unsigned long nr_segs)
Josh Triplett105f4d72006-09-29 01:59:25 -0700697 __releases(fc->lock)
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700698{
699 struct fuse_copy_state cs;
700 struct fuse_in_header ih;
701 struct fuse_interrupt_in arg;
702 unsigned reqsize = sizeof(ih) + sizeof(arg);
703 int err;
704
705 list_del_init(&req->intr_entry);
706 req->intr_unique = fuse_get_unique(fc);
707 memset(&ih, 0, sizeof(ih));
708 memset(&arg, 0, sizeof(arg));
709 ih.len = reqsize;
710 ih.opcode = FUSE_INTERRUPT;
711 ih.unique = req->intr_unique;
712 arg.unique = req->in.h.unique;
713
714 spin_unlock(&fc->lock);
715 if (iov_length(iov, nr_segs) < reqsize)
716 return -EINVAL;
717
718 fuse_copy_init(&cs, fc, 1, NULL, iov, nr_segs);
719 err = fuse_copy_one(&cs, &ih, sizeof(ih));
720 if (!err)
721 err = fuse_copy_one(&cs, &arg, sizeof(arg));
722 fuse_copy_finish(&cs);
723
724 return err ? err : reqsize;
725}
726
727/*
Miklos Szeredi334f4852005-09-09 13:10:27 -0700728 * Read a single request into the userspace filesystem's buffer. This
729 * function waits until a request is available, then removes it from
730 * the pending list and copies request data to userspace buffer. If
Miklos Szeredif9a28422006-06-25 05:48:53 -0700731 * no reply is needed (FORGET) or request has been aborted or there
732 * was an error during the copying then it's finished by calling
Miklos Szeredi334f4852005-09-09 13:10:27 -0700733 * request_end(). Otherwise add it to the processing list, and set
734 * the 'sent' flag.
735 */
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700736static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
737 unsigned long nr_segs, loff_t pos)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700738{
739 int err;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700740 struct fuse_req *req;
741 struct fuse_in *in;
742 struct fuse_copy_state cs;
743 unsigned reqsize;
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700744 struct file *file = iocb->ki_filp;
Miklos Szeredi0720b312006-04-10 22:54:55 -0700745 struct fuse_conn *fc = fuse_get_conn(file);
746 if (!fc)
747 return -EPERM;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700748
Miklos Szeredi1d3d7522006-01-06 00:19:40 -0800749 restart:
Miklos Szeredid7133112006-04-10 22:54:55 -0700750 spin_lock(&fc->lock);
Jeff Dikee5ac1d12006-04-10 22:54:53 -0700751 err = -EAGAIN;
752 if ((file->f_flags & O_NONBLOCK) && fc->connected &&
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700753 !request_pending(fc))
Jeff Dikee5ac1d12006-04-10 22:54:53 -0700754 goto err_unlock;
755
Miklos Szeredi334f4852005-09-09 13:10:27 -0700756 request_wait(fc);
757 err = -ENODEV;
Miklos Szeredi9ba7cbb2006-01-16 22:14:34 -0800758 if (!fc->connected)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700759 goto err_unlock;
760 err = -ERESTARTSYS;
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700761 if (!request_pending(fc))
Miklos Szeredi334f4852005-09-09 13:10:27 -0700762 goto err_unlock;
763
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700764 if (!list_empty(&fc->interrupts)) {
765 req = list_entry(fc->interrupts.next, struct fuse_req,
766 intr_entry);
767 return fuse_read_interrupt(fc, req, iov, nr_segs);
768 }
769
Miklos Szeredi334f4852005-09-09 13:10:27 -0700770 req = list_entry(fc->pending.next, struct fuse_req, list);
Miklos Szeredi83cfd492006-01-16 22:14:31 -0800771 req->state = FUSE_REQ_READING;
Miklos Szeredid77a1d52006-01-16 22:14:31 -0800772 list_move(&req->list, &fc->io);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700773
774 in = &req->in;
Miklos Szeredi1d3d7522006-01-06 00:19:40 -0800775 reqsize = in->h.len;
776 /* If request is too large, reply with an error and restart the read */
777 if (iov_length(iov, nr_segs) < reqsize) {
778 req->out.h.error = -EIO;
779 /* SETXATTR is special, since it may contain too large data */
780 if (in->h.opcode == FUSE_SETXATTR)
781 req->out.h.error = -E2BIG;
782 request_end(fc, req);
783 goto restart;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700784 }
Miklos Szeredid7133112006-04-10 22:54:55 -0700785 spin_unlock(&fc->lock);
786 fuse_copy_init(&cs, fc, 1, req, iov, nr_segs);
Miklos Szeredi1d3d7522006-01-06 00:19:40 -0800787 err = fuse_copy_one(&cs, &in->h, sizeof(in->h));
788 if (!err)
789 err = fuse_copy_args(&cs, in->numargs, in->argpages,
790 (struct fuse_arg *) in->args, 0);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700791 fuse_copy_finish(&cs);
Miklos Szeredid7133112006-04-10 22:54:55 -0700792 spin_lock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700793 req->locked = 0;
Miklos Szeredic9c9d7d2007-10-16 23:31:05 -0700794 if (req->aborted) {
795 request_end(fc, req);
796 return -ENODEV;
797 }
Miklos Szeredi334f4852005-09-09 13:10:27 -0700798 if (err) {
Miklos Szeredic9c9d7d2007-10-16 23:31:05 -0700799 req->out.h.error = -EIO;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700800 request_end(fc, req);
801 return err;
802 }
803 if (!req->isreply)
804 request_end(fc, req);
805 else {
Miklos Szeredi83cfd492006-01-16 22:14:31 -0800806 req->state = FUSE_REQ_SENT;
Miklos Szeredid77a1d52006-01-16 22:14:31 -0800807 list_move_tail(&req->list, &fc->processing);
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700808 if (req->interrupted)
809 queue_interrupt(fc, req);
Miklos Szeredid7133112006-04-10 22:54:55 -0700810 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700811 }
812 return reqsize;
813
814 err_unlock:
Miklos Szeredid7133112006-04-10 22:54:55 -0700815 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700816 return err;
817}
818
Miklos Szeredi334f4852005-09-09 13:10:27 -0700819/* Look up request on processing list by unique ID */
820static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
821{
822 struct list_head *entry;
823
824 list_for_each(entry, &fc->processing) {
825 struct fuse_req *req;
826 req = list_entry(entry, struct fuse_req, list);
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700827 if (req->in.h.unique == unique || req->intr_unique == unique)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700828 return req;
829 }
830 return NULL;
831}
832
833static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
834 unsigned nbytes)
835{
836 unsigned reqsize = sizeof(struct fuse_out_header);
837
838 if (out->h.error)
839 return nbytes != reqsize ? -EINVAL : 0;
840
841 reqsize += len_args(out->numargs, out->args);
842
843 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
844 return -EINVAL;
845 else if (reqsize > nbytes) {
846 struct fuse_arg *lastarg = &out->args[out->numargs-1];
847 unsigned diffsize = reqsize - nbytes;
848 if (diffsize > lastarg->size)
849 return -EINVAL;
850 lastarg->size -= diffsize;
851 }
852 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
853 out->page_zeroing);
854}
855
856/*
857 * Write a single reply to a request. First the header is copied from
858 * the write buffer. The request is then searched on the processing
859 * list by the unique ID found in the header. If found, then remove
860 * it from the list and copy the rest of the buffer to the request.
861 * The request is finished by calling request_end()
862 */
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700863static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
864 unsigned long nr_segs, loff_t pos)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700865{
866 int err;
867 unsigned nbytes = iov_length(iov, nr_segs);
868 struct fuse_req *req;
869 struct fuse_out_header oh;
870 struct fuse_copy_state cs;
Badari Pulavartyee0b3e62006-09-30 23:28:47 -0700871 struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700872 if (!fc)
Miklos Szeredia87046d2006-04-10 22:54:56 -0700873 return -EPERM;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700874
Miklos Szeredid7133112006-04-10 22:54:55 -0700875 fuse_copy_init(&cs, fc, 0, NULL, iov, nr_segs);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700876 if (nbytes < sizeof(struct fuse_out_header))
877 return -EINVAL;
878
879 err = fuse_copy_one(&cs, &oh, sizeof(oh));
880 if (err)
881 goto err_finish;
882 err = -EINVAL;
883 if (!oh.unique || oh.error <= -1000 || oh.error > 0 ||
884 oh.len != nbytes)
885 goto err_finish;
886
Miklos Szeredid7133112006-04-10 22:54:55 -0700887 spin_lock(&fc->lock);
Miklos Szeredi69a53bf2006-01-16 22:14:41 -0800888 err = -ENOENT;
889 if (!fc->connected)
890 goto err_unlock;
891
Miklos Szeredi334f4852005-09-09 13:10:27 -0700892 req = request_find(fc, oh.unique);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700893 if (!req)
894 goto err_unlock;
895
Miklos Szeredif9a28422006-06-25 05:48:53 -0700896 if (req->aborted) {
Miklos Szeredid7133112006-04-10 22:54:55 -0700897 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700898 fuse_copy_finish(&cs);
Miklos Szeredid7133112006-04-10 22:54:55 -0700899 spin_lock(&fc->lock);
Miklos Szeredi222f1d62006-01-16 22:14:25 -0800900 request_end(fc, req);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700901 return -ENOENT;
902 }
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700903 /* Is it an interrupt reply? */
904 if (req->intr_unique == oh.unique) {
905 err = -EINVAL;
906 if (nbytes != sizeof(struct fuse_out_header))
907 goto err_unlock;
908
909 if (oh.error == -ENOSYS)
910 fc->no_interrupt = 1;
911 else if (oh.error == -EAGAIN)
912 queue_interrupt(fc, req);
913
914 spin_unlock(&fc->lock);
915 fuse_copy_finish(&cs);
916 return nbytes;
917 }
918
919 req->state = FUSE_REQ_WRITING;
Miklos Szeredid77a1d52006-01-16 22:14:31 -0800920 list_move(&req->list, &fc->io);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700921 req->out.h = oh;
922 req->locked = 1;
923 cs.req = req;
Miklos Szeredid7133112006-04-10 22:54:55 -0700924 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700925
926 err = copy_out_args(&cs, &req->out, nbytes);
927 fuse_copy_finish(&cs);
928
Miklos Szeredid7133112006-04-10 22:54:55 -0700929 spin_lock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700930 req->locked = 0;
931 if (!err) {
Miklos Szeredif9a28422006-06-25 05:48:53 -0700932 if (req->aborted)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700933 err = -ENOENT;
Miklos Szeredif9a28422006-06-25 05:48:53 -0700934 } else if (!req->aborted)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700935 req->out.h.error = -EIO;
936 request_end(fc, req);
937
938 return err ? err : nbytes;
939
940 err_unlock:
Miklos Szeredid7133112006-04-10 22:54:55 -0700941 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700942 err_finish:
943 fuse_copy_finish(&cs);
944 return err;
945}
946
Miklos Szeredi334f4852005-09-09 13:10:27 -0700947static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
948{
Miklos Szeredi334f4852005-09-09 13:10:27 -0700949 unsigned mask = POLLOUT | POLLWRNORM;
Miklos Szeredi7025d9a2006-04-10 22:54:50 -0700950 struct fuse_conn *fc = fuse_get_conn(file);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700951 if (!fc)
Miklos Szeredi7025d9a2006-04-10 22:54:50 -0700952 return POLLERR;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700953
954 poll_wait(file, &fc->waitq, wait);
955
Miklos Szeredid7133112006-04-10 22:54:55 -0700956 spin_lock(&fc->lock);
Miklos Szeredi7025d9a2006-04-10 22:54:50 -0700957 if (!fc->connected)
958 mask = POLLERR;
Miklos Szeredia4d27e72006-06-25 05:48:54 -0700959 else if (request_pending(fc))
Miklos Szeredi7025d9a2006-04-10 22:54:50 -0700960 mask |= POLLIN | POLLRDNORM;
Miklos Szeredid7133112006-04-10 22:54:55 -0700961 spin_unlock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700962
963 return mask;
964}
965
Miklos Szeredi69a53bf2006-01-16 22:14:41 -0800966/*
967 * Abort all requests on the given list (pending or processing)
968 *
Miklos Szeredid7133112006-04-10 22:54:55 -0700969 * This function releases and reacquires fc->lock
Miklos Szeredi69a53bf2006-01-16 22:14:41 -0800970 */
Miklos Szeredi334f4852005-09-09 13:10:27 -0700971static void end_requests(struct fuse_conn *fc, struct list_head *head)
972{
973 while (!list_empty(head)) {
974 struct fuse_req *req;
975 req = list_entry(head->next, struct fuse_req, list);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700976 req->out.h.error = -ECONNABORTED;
977 request_end(fc, req);
Miklos Szeredid7133112006-04-10 22:54:55 -0700978 spin_lock(&fc->lock);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700979 }
980}
981
Miklos Szeredi69a53bf2006-01-16 22:14:41 -0800982/*
983 * Abort requests under I/O
984 *
Miklos Szeredif9a28422006-06-25 05:48:53 -0700985 * The requests are set to aborted and finished, and the request
Miklos Szeredi69a53bf2006-01-16 22:14:41 -0800986 * waiter is woken up. This will make request_wait_answer() wait
987 * until the request is unlocked and then return.
Miklos Szeredi64c6d8e2006-01-16 22:14:42 -0800988 *
989 * If the request is asynchronous, then the end function needs to be
990 * called after waiting for the request to be unlocked (if it was
991 * locked).
Miklos Szeredi69a53bf2006-01-16 22:14:41 -0800992 */
993static void end_io_requests(struct fuse_conn *fc)
Miklos Szeredi4dbf9302008-04-30 00:54:45 -0700994 __releases(fc->lock) __acquires(fc->lock)
Miklos Szeredi69a53bf2006-01-16 22:14:41 -0800995{
996 while (!list_empty(&fc->io)) {
Miklos Szeredi64c6d8e2006-01-16 22:14:42 -0800997 struct fuse_req *req =
998 list_entry(fc->io.next, struct fuse_req, list);
999 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
1000
Miklos Szeredif9a28422006-06-25 05:48:53 -07001001 req->aborted = 1;
Miklos Szeredi69a53bf2006-01-16 22:14:41 -08001002 req->out.h.error = -ECONNABORTED;
1003 req->state = FUSE_REQ_FINISHED;
1004 list_del_init(&req->list);
1005 wake_up(&req->waitq);
Miklos Szeredi64c6d8e2006-01-16 22:14:42 -08001006 if (end) {
1007 req->end = NULL;
Miklos Szeredi64c6d8e2006-01-16 22:14:42 -08001008 __fuse_get_request(req);
Miklos Szeredid7133112006-04-10 22:54:55 -07001009 spin_unlock(&fc->lock);
Miklos Szeredi64c6d8e2006-01-16 22:14:42 -08001010 wait_event(req->waitq, !req->locked);
1011 end(fc, req);
Tejun Heoe9bb09d2008-11-26 12:03:54 +01001012 fuse_put_request(fc, req);
Miklos Szeredid7133112006-04-10 22:54:55 -07001013 spin_lock(&fc->lock);
Miklos Szeredi64c6d8e2006-01-16 22:14:42 -08001014 }
Miklos Szeredi69a53bf2006-01-16 22:14:41 -08001015 }
1016}
1017
1018/*
1019 * Abort all requests.
1020 *
1021 * Emergency exit in case of a malicious or accidental deadlock, or
1022 * just a hung filesystem.
1023 *
1024 * The same effect is usually achievable through killing the
1025 * filesystem daemon and all users of the filesystem. The exception
1026 * is the combination of an asynchronous request and the tricky
1027 * deadlock (see Documentation/filesystems/fuse.txt).
1028 *
1029 * During the aborting, progression of requests from the pending and
1030 * processing lists onto the io list, and progression of new requests
1031 * onto the pending list is prevented by req->connected being false.
1032 *
1033 * Progression of requests under I/O to the processing list is
Miklos Szeredif9a28422006-06-25 05:48:53 -07001034 * prevented by the req->aborted flag being true for these requests.
1035 * For this reason requests on the io list must be aborted first.
Miklos Szeredi69a53bf2006-01-16 22:14:41 -08001036 */
1037void fuse_abort_conn(struct fuse_conn *fc)
1038{
Miklos Szeredid7133112006-04-10 22:54:55 -07001039 spin_lock(&fc->lock);
Miklos Szeredi69a53bf2006-01-16 22:14:41 -08001040 if (fc->connected) {
1041 fc->connected = 0;
Miklos Szeredi51eb01e2006-06-25 05:48:50 -07001042 fc->blocked = 0;
Miklos Szeredi69a53bf2006-01-16 22:14:41 -08001043 end_io_requests(fc);
1044 end_requests(fc, &fc->pending);
1045 end_requests(fc, &fc->processing);
1046 wake_up_all(&fc->waitq);
Miklos Szeredi51eb01e2006-06-25 05:48:50 -07001047 wake_up_all(&fc->blocked_waitq);
Jeff Dike385a17b2006-04-10 22:54:52 -07001048 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
Miklos Szeredi69a53bf2006-01-16 22:14:41 -08001049 }
Miklos Szeredid7133112006-04-10 22:54:55 -07001050 spin_unlock(&fc->lock);
Miklos Szeredi69a53bf2006-01-16 22:14:41 -08001051}
1052
Miklos Szeredi334f4852005-09-09 13:10:27 -07001053static int fuse_dev_release(struct inode *inode, struct file *file)
1054{
Miklos Szeredi0720b312006-04-10 22:54:55 -07001055 struct fuse_conn *fc = fuse_get_conn(file);
Miklos Szeredi334f4852005-09-09 13:10:27 -07001056 if (fc) {
Miklos Szeredid7133112006-04-10 22:54:55 -07001057 spin_lock(&fc->lock);
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -07001058 fc->connected = 0;
Miklos Szeredi334f4852005-09-09 13:10:27 -07001059 end_requests(fc, &fc->pending);
1060 end_requests(fc, &fc->processing);
Miklos Szeredid7133112006-04-10 22:54:55 -07001061 spin_unlock(&fc->lock);
Miklos Szeredibafa9652006-06-25 05:48:51 -07001062 fuse_conn_put(fc);
Jeff Dike385a17b2006-04-10 22:54:52 -07001063 }
Miklos Szeredif543f252006-01-16 22:14:35 -08001064
Miklos Szeredi334f4852005-09-09 13:10:27 -07001065 return 0;
1066}
1067
Jeff Dike385a17b2006-04-10 22:54:52 -07001068static int fuse_dev_fasync(int fd, struct file *file, int on)
1069{
1070 struct fuse_conn *fc = fuse_get_conn(file);
1071 if (!fc)
Miklos Szeredia87046d2006-04-10 22:54:56 -07001072 return -EPERM;
Jeff Dike385a17b2006-04-10 22:54:52 -07001073
1074 /* No locking - fasync_helper does its own locking */
1075 return fasync_helper(fd, file, on, &fc->fasync);
1076}
1077
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -08001078const struct file_operations fuse_dev_operations = {
Miklos Szeredi334f4852005-09-09 13:10:27 -07001079 .owner = THIS_MODULE,
1080 .llseek = no_llseek,
Badari Pulavartyee0b3e62006-09-30 23:28:47 -07001081 .read = do_sync_read,
1082 .aio_read = fuse_dev_read,
1083 .write = do_sync_write,
1084 .aio_write = fuse_dev_write,
Miklos Szeredi334f4852005-09-09 13:10:27 -07001085 .poll = fuse_dev_poll,
1086 .release = fuse_dev_release,
Jeff Dike385a17b2006-04-10 22:54:52 -07001087 .fasync = fuse_dev_fasync,
Miklos Szeredi334f4852005-09-09 13:10:27 -07001088};
1089
1090static struct miscdevice fuse_miscdevice = {
1091 .minor = FUSE_MINOR,
1092 .name = "fuse",
1093 .fops = &fuse_dev_operations,
1094};
1095
1096int __init fuse_dev_init(void)
1097{
1098 int err = -ENOMEM;
1099 fuse_req_cachep = kmem_cache_create("fuse_request",
1100 sizeof(struct fuse_req),
Paul Mundt20c2df82007-07-20 10:11:58 +09001101 0, 0, NULL);
Miklos Szeredi334f4852005-09-09 13:10:27 -07001102 if (!fuse_req_cachep)
1103 goto out;
1104
1105 err = misc_register(&fuse_miscdevice);
1106 if (err)
1107 goto out_cache_clean;
1108
1109 return 0;
1110
1111 out_cache_clean:
1112 kmem_cache_destroy(fuse_req_cachep);
1113 out:
1114 return err;
1115}
1116
1117void fuse_dev_cleanup(void)
1118{
1119 misc_deregister(&fuse_miscdevice);
1120 kmem_cache_destroy(fuse_req_cachep);
1121}