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Merge tag 'driver-core-4.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git...
[mirror_ubuntu-jammy-kernel.git] / fs / fuse / dev.c
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
4
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 #include <linux/pipe_fs_i.h>
20 #include <linux/swap.h>
21 #include <linux/splice.h>
22 #include <linux/aio.h>
23
24 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
25 MODULE_ALIAS("devname:fuse");
26
27 static struct kmem_cache *fuse_req_cachep;
28
29 static struct fuse_conn *fuse_get_conn(struct file *file)
30 {
31 /*
32 * Lockless access is OK, because file->private data is set
33 * once during mount and is valid until the file is released.
34 */
35 return file->private_data;
36 }
37
38 static void fuse_request_init(struct fuse_req *req, struct page **pages,
39 struct fuse_page_desc *page_descs,
40 unsigned npages)
41 {
42 memset(req, 0, sizeof(*req));
43 memset(pages, 0, sizeof(*pages) * npages);
44 memset(page_descs, 0, sizeof(*page_descs) * npages);
45 INIT_LIST_HEAD(&req->list);
46 INIT_LIST_HEAD(&req->intr_entry);
47 init_waitqueue_head(&req->waitq);
48 atomic_set(&req->count, 1);
49 req->pages = pages;
50 req->page_descs = page_descs;
51 req->max_pages = npages;
52 }
53
54 static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
55 {
56 struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags);
57 if (req) {
58 struct page **pages;
59 struct fuse_page_desc *page_descs;
60
61 if (npages <= FUSE_REQ_INLINE_PAGES) {
62 pages = req->inline_pages;
63 page_descs = req->inline_page_descs;
64 } else {
65 pages = kmalloc(sizeof(struct page *) * npages, flags);
66 page_descs = kmalloc(sizeof(struct fuse_page_desc) *
67 npages, flags);
68 }
69
70 if (!pages || !page_descs) {
71 kfree(pages);
72 kfree(page_descs);
73 kmem_cache_free(fuse_req_cachep, req);
74 return NULL;
75 }
76
77 fuse_request_init(req, pages, page_descs, npages);
78 }
79 return req;
80 }
81
82 struct fuse_req *fuse_request_alloc(unsigned npages)
83 {
84 return __fuse_request_alloc(npages, GFP_KERNEL);
85 }
86 EXPORT_SYMBOL_GPL(fuse_request_alloc);
87
88 struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
89 {
90 return __fuse_request_alloc(npages, GFP_NOFS);
91 }
92
93 void fuse_request_free(struct fuse_req *req)
94 {
95 if (req->pages != req->inline_pages) {
96 kfree(req->pages);
97 kfree(req->page_descs);
98 }
99 kmem_cache_free(fuse_req_cachep, req);
100 }
101
102 static void block_sigs(sigset_t *oldset)
103 {
104 sigset_t mask;
105
106 siginitsetinv(&mask, sigmask(SIGKILL));
107 sigprocmask(SIG_BLOCK, &mask, oldset);
108 }
109
110 static void restore_sigs(sigset_t *oldset)
111 {
112 sigprocmask(SIG_SETMASK, oldset, NULL);
113 }
114
115 void __fuse_get_request(struct fuse_req *req)
116 {
117 atomic_inc(&req->count);
118 }
119
120 /* Must be called with > 1 refcount */
121 static void __fuse_put_request(struct fuse_req *req)
122 {
123 BUG_ON(atomic_read(&req->count) < 2);
124 atomic_dec(&req->count);
125 }
126
127 static void fuse_req_init_context(struct fuse_req *req)
128 {
129 req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid());
130 req->in.h.gid = from_kgid_munged(&init_user_ns, current_fsgid());
131 req->in.h.pid = current->pid;
132 }
133
134 void fuse_set_initialized(struct fuse_conn *fc)
135 {
136 /* Make sure stores before this are seen on another CPU */
137 smp_wmb();
138 fc->initialized = 1;
139 }
140
141 static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
142 {
143 return !fc->initialized || (for_background && fc->blocked);
144 }
145
146 static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
147 bool for_background)
148 {
149 struct fuse_req *req;
150 int err;
151 atomic_inc(&fc->num_waiting);
152
153 if (fuse_block_alloc(fc, for_background)) {
154 sigset_t oldset;
155 int intr;
156
157 block_sigs(&oldset);
158 intr = wait_event_interruptible_exclusive(fc->blocked_waitq,
159 !fuse_block_alloc(fc, for_background));
160 restore_sigs(&oldset);
161 err = -EINTR;
162 if (intr)
163 goto out;
164 }
165 /* Matches smp_wmb() in fuse_set_initialized() */
166 smp_rmb();
167
168 err = -ENOTCONN;
169 if (!fc->connected)
170 goto out;
171
172 req = fuse_request_alloc(npages);
173 err = -ENOMEM;
174 if (!req) {
175 if (for_background)
176 wake_up(&fc->blocked_waitq);
177 goto out;
178 }
179
180 fuse_req_init_context(req);
181 req->waiting = 1;
182 req->background = for_background;
183 return req;
184
185 out:
186 atomic_dec(&fc->num_waiting);
187 return ERR_PTR(err);
188 }
189
190 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
191 {
192 return __fuse_get_req(fc, npages, false);
193 }
194 EXPORT_SYMBOL_GPL(fuse_get_req);
195
196 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
197 unsigned npages)
198 {
199 return __fuse_get_req(fc, npages, true);
200 }
201 EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
202
203 /*
204 * Return request in fuse_file->reserved_req. However that may
205 * currently be in use. If that is the case, wait for it to become
206 * available.
207 */
208 static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
209 struct file *file)
210 {
211 struct fuse_req *req = NULL;
212 struct fuse_file *ff = file->private_data;
213
214 do {
215 wait_event(fc->reserved_req_waitq, ff->reserved_req);
216 spin_lock(&fc->lock);
217 if (ff->reserved_req) {
218 req = ff->reserved_req;
219 ff->reserved_req = NULL;
220 req->stolen_file = get_file(file);
221 }
222 spin_unlock(&fc->lock);
223 } while (!req);
224
225 return req;
226 }
227
228 /*
229 * Put stolen request back into fuse_file->reserved_req
230 */
231 static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
232 {
233 struct file *file = req->stolen_file;
234 struct fuse_file *ff = file->private_data;
235
236 spin_lock(&fc->lock);
237 fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
238 BUG_ON(ff->reserved_req);
239 ff->reserved_req = req;
240 wake_up_all(&fc->reserved_req_waitq);
241 spin_unlock(&fc->lock);
242 fput(file);
243 }
244
245 /*
246 * Gets a requests for a file operation, always succeeds
247 *
248 * This is used for sending the FLUSH request, which must get to
249 * userspace, due to POSIX locks which may need to be unlocked.
250 *
251 * If allocation fails due to OOM, use the reserved request in
252 * fuse_file.
253 *
254 * This is very unlikely to deadlock accidentally, since the
255 * filesystem should not have it's own file open. If deadlock is
256 * intentional, it can still be broken by "aborting" the filesystem.
257 */
258 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
259 struct file *file)
260 {
261 struct fuse_req *req;
262
263 atomic_inc(&fc->num_waiting);
264 wait_event(fc->blocked_waitq, fc->initialized);
265 /* Matches smp_wmb() in fuse_set_initialized() */
266 smp_rmb();
267 req = fuse_request_alloc(0);
268 if (!req)
269 req = get_reserved_req(fc, file);
270
271 fuse_req_init_context(req);
272 req->waiting = 1;
273 req->background = 0;
274 return req;
275 }
276
277 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
278 {
279 if (atomic_dec_and_test(&req->count)) {
280 if (unlikely(req->background)) {
281 /*
282 * We get here in the unlikely case that a background
283 * request was allocated but not sent
284 */
285 spin_lock(&fc->lock);
286 if (!fc->blocked)
287 wake_up(&fc->blocked_waitq);
288 spin_unlock(&fc->lock);
289 }
290
291 if (req->waiting)
292 atomic_dec(&fc->num_waiting);
293
294 if (req->stolen_file)
295 put_reserved_req(fc, req);
296 else
297 fuse_request_free(req);
298 }
299 }
300 EXPORT_SYMBOL_GPL(fuse_put_request);
301
302 static unsigned len_args(unsigned numargs, struct fuse_arg *args)
303 {
304 unsigned nbytes = 0;
305 unsigned i;
306
307 for (i = 0; i < numargs; i++)
308 nbytes += args[i].size;
309
310 return nbytes;
311 }
312
313 static u64 fuse_get_unique(struct fuse_conn *fc)
314 {
315 fc->reqctr++;
316 /* zero is special */
317 if (fc->reqctr == 0)
318 fc->reqctr = 1;
319
320 return fc->reqctr;
321 }
322
323 static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
324 {
325 req->in.h.len = sizeof(struct fuse_in_header) +
326 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
327 list_add_tail(&req->list, &fc->pending);
328 req->state = FUSE_REQ_PENDING;
329 if (!req->waiting) {
330 req->waiting = 1;
331 atomic_inc(&fc->num_waiting);
332 }
333 wake_up(&fc->waitq);
334 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
335 }
336
337 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
338 u64 nodeid, u64 nlookup)
339 {
340 forget->forget_one.nodeid = nodeid;
341 forget->forget_one.nlookup = nlookup;
342
343 spin_lock(&fc->lock);
344 if (fc->connected) {
345 fc->forget_list_tail->next = forget;
346 fc->forget_list_tail = forget;
347 wake_up(&fc->waitq);
348 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
349 } else {
350 kfree(forget);
351 }
352 spin_unlock(&fc->lock);
353 }
354
355 static void flush_bg_queue(struct fuse_conn *fc)
356 {
357 while (fc->active_background < fc->max_background &&
358 !list_empty(&fc->bg_queue)) {
359 struct fuse_req *req;
360
361 req = list_entry(fc->bg_queue.next, struct fuse_req, list);
362 list_del(&req->list);
363 fc->active_background++;
364 req->in.h.unique = fuse_get_unique(fc);
365 queue_request(fc, req);
366 }
367 }
368
369 /*
370 * This function is called when a request is finished. Either a reply
371 * has arrived or it was aborted (and not yet sent) or some error
372 * occurred during communication with userspace, or the device file
373 * was closed. The requester thread is woken up (if still waiting),
374 * the 'end' callback is called if given, else the reference to the
375 * request is released
376 *
377 * Called with fc->lock, unlocks it
378 */
379 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
380 __releases(fc->lock)
381 {
382 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
383 req->end = NULL;
384 list_del(&req->list);
385 list_del(&req->intr_entry);
386 req->state = FUSE_REQ_FINISHED;
387 if (req->background) {
388 req->background = 0;
389
390 if (fc->num_background == fc->max_background)
391 fc->blocked = 0;
392
393 /* Wake up next waiter, if any */
394 if (!fc->blocked && waitqueue_active(&fc->blocked_waitq))
395 wake_up(&fc->blocked_waitq);
396
397 if (fc->num_background == fc->congestion_threshold &&
398 fc->connected && fc->bdi_initialized) {
399 clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
400 clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
401 }
402 fc->num_background--;
403 fc->active_background--;
404 flush_bg_queue(fc);
405 }
406 spin_unlock(&fc->lock);
407 wake_up(&req->waitq);
408 if (end)
409 end(fc, req);
410 fuse_put_request(fc, req);
411 }
412
413 static void wait_answer_interruptible(struct fuse_conn *fc,
414 struct fuse_req *req)
415 __releases(fc->lock)
416 __acquires(fc->lock)
417 {
418 if (signal_pending(current))
419 return;
420
421 spin_unlock(&fc->lock);
422 wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
423 spin_lock(&fc->lock);
424 }
425
426 static void queue_interrupt(struct fuse_conn *fc, struct fuse_req *req)
427 {
428 list_add_tail(&req->intr_entry, &fc->interrupts);
429 wake_up(&fc->waitq);
430 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
431 }
432
433 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
434 __releases(fc->lock)
435 __acquires(fc->lock)
436 {
437 if (!fc->no_interrupt) {
438 /* Any signal may interrupt this */
439 wait_answer_interruptible(fc, req);
440
441 if (req->aborted)
442 goto aborted;
443 if (req->state == FUSE_REQ_FINISHED)
444 return;
445
446 req->interrupted = 1;
447 if (req->state == FUSE_REQ_SENT)
448 queue_interrupt(fc, req);
449 }
450
451 if (!req->force) {
452 sigset_t oldset;
453
454 /* Only fatal signals may interrupt this */
455 block_sigs(&oldset);
456 wait_answer_interruptible(fc, req);
457 restore_sigs(&oldset);
458
459 if (req->aborted)
460 goto aborted;
461 if (req->state == FUSE_REQ_FINISHED)
462 return;
463
464 /* Request is not yet in userspace, bail out */
465 if (req->state == FUSE_REQ_PENDING) {
466 list_del(&req->list);
467 __fuse_put_request(req);
468 req->out.h.error = -EINTR;
469 return;
470 }
471 }
472
473 /*
474 * Either request is already in userspace, or it was forced.
475 * Wait it out.
476 */
477 spin_unlock(&fc->lock);
478 wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
479 spin_lock(&fc->lock);
480
481 if (!req->aborted)
482 return;
483
484 aborted:
485 BUG_ON(req->state != FUSE_REQ_FINISHED);
486 if (req->locked) {
487 /* This is uninterruptible sleep, because data is
488 being copied to/from the buffers of req. During
489 locked state, there mustn't be any filesystem
490 operation (e.g. page fault), since that could lead
491 to deadlock */
492 spin_unlock(&fc->lock);
493 wait_event(req->waitq, !req->locked);
494 spin_lock(&fc->lock);
495 }
496 }
497
498 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
499 {
500 BUG_ON(req->background);
501 spin_lock(&fc->lock);
502 if (!fc->connected)
503 req->out.h.error = -ENOTCONN;
504 else if (fc->conn_error)
505 req->out.h.error = -ECONNREFUSED;
506 else {
507 req->in.h.unique = fuse_get_unique(fc);
508 queue_request(fc, req);
509 /* acquire extra reference, since request is still needed
510 after request_end() */
511 __fuse_get_request(req);
512
513 request_wait_answer(fc, req);
514 }
515 spin_unlock(&fc->lock);
516 }
517
518 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
519 {
520 req->isreply = 1;
521 __fuse_request_send(fc, req);
522 }
523 EXPORT_SYMBOL_GPL(fuse_request_send);
524
525 static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
526 {
527 if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS)
528 args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE;
529
530 if (fc->minor < 9) {
531 switch (args->in.h.opcode) {
532 case FUSE_LOOKUP:
533 case FUSE_CREATE:
534 case FUSE_MKNOD:
535 case FUSE_MKDIR:
536 case FUSE_SYMLINK:
537 case FUSE_LINK:
538 args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
539 break;
540 case FUSE_GETATTR:
541 case FUSE_SETATTR:
542 args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
543 break;
544 }
545 }
546 if (fc->minor < 12) {
547 switch (args->in.h.opcode) {
548 case FUSE_CREATE:
549 args->in.args[0].size = sizeof(struct fuse_open_in);
550 break;
551 case FUSE_MKNOD:
552 args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
553 break;
554 }
555 }
556 }
557
558 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
559 {
560 struct fuse_req *req;
561 ssize_t ret;
562
563 req = fuse_get_req(fc, 0);
564 if (IS_ERR(req))
565 return PTR_ERR(req);
566
567 /* Needs to be done after fuse_get_req() so that fc->minor is valid */
568 fuse_adjust_compat(fc, args);
569
570 req->in.h.opcode = args->in.h.opcode;
571 req->in.h.nodeid = args->in.h.nodeid;
572 req->in.numargs = args->in.numargs;
573 memcpy(req->in.args, args->in.args,
574 args->in.numargs * sizeof(struct fuse_in_arg));
575 req->out.argvar = args->out.argvar;
576 req->out.numargs = args->out.numargs;
577 memcpy(req->out.args, args->out.args,
578 args->out.numargs * sizeof(struct fuse_arg));
579 fuse_request_send(fc, req);
580 ret = req->out.h.error;
581 if (!ret && args->out.argvar) {
582 BUG_ON(args->out.numargs != 1);
583 ret = req->out.args[0].size;
584 }
585 fuse_put_request(fc, req);
586
587 return ret;
588 }
589
590 static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
591 struct fuse_req *req)
592 {
593 BUG_ON(!req->background);
594 fc->num_background++;
595 if (fc->num_background == fc->max_background)
596 fc->blocked = 1;
597 if (fc->num_background == fc->congestion_threshold &&
598 fc->bdi_initialized) {
599 set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
600 set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
601 }
602 list_add_tail(&req->list, &fc->bg_queue);
603 flush_bg_queue(fc);
604 }
605
606 static void fuse_request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
607 {
608 spin_lock(&fc->lock);
609 if (fc->connected) {
610 fuse_request_send_nowait_locked(fc, req);
611 spin_unlock(&fc->lock);
612 } else {
613 req->out.h.error = -ENOTCONN;
614 request_end(fc, req);
615 }
616 }
617
618 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
619 {
620 req->isreply = 1;
621 fuse_request_send_nowait(fc, req);
622 }
623 EXPORT_SYMBOL_GPL(fuse_request_send_background);
624
625 static int fuse_request_send_notify_reply(struct fuse_conn *fc,
626 struct fuse_req *req, u64 unique)
627 {
628 int err = -ENODEV;
629
630 req->isreply = 0;
631 req->in.h.unique = unique;
632 spin_lock(&fc->lock);
633 if (fc->connected) {
634 queue_request(fc, req);
635 err = 0;
636 }
637 spin_unlock(&fc->lock);
638
639 return err;
640 }
641
642 /*
643 * Called under fc->lock
644 *
645 * fc->connected must have been checked previously
646 */
647 void fuse_request_send_background_locked(struct fuse_conn *fc,
648 struct fuse_req *req)
649 {
650 req->isreply = 1;
651 fuse_request_send_nowait_locked(fc, req);
652 }
653
654 void fuse_force_forget(struct file *file, u64 nodeid)
655 {
656 struct inode *inode = file_inode(file);
657 struct fuse_conn *fc = get_fuse_conn(inode);
658 struct fuse_req *req;
659 struct fuse_forget_in inarg;
660
661 memset(&inarg, 0, sizeof(inarg));
662 inarg.nlookup = 1;
663 req = fuse_get_req_nofail_nopages(fc, file);
664 req->in.h.opcode = FUSE_FORGET;
665 req->in.h.nodeid = nodeid;
666 req->in.numargs = 1;
667 req->in.args[0].size = sizeof(inarg);
668 req->in.args[0].value = &inarg;
669 req->isreply = 0;
670 __fuse_request_send(fc, req);
671 /* ignore errors */
672 fuse_put_request(fc, req);
673 }
674
675 /*
676 * Lock the request. Up to the next unlock_request() there mustn't be
677 * anything that could cause a page-fault. If the request was already
678 * aborted bail out.
679 */
680 static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
681 {
682 int err = 0;
683 if (req) {
684 spin_lock(&fc->lock);
685 if (req->aborted)
686 err = -ENOENT;
687 else
688 req->locked = 1;
689 spin_unlock(&fc->lock);
690 }
691 return err;
692 }
693
694 /*
695 * Unlock request. If it was aborted during being locked, the
696 * requester thread is currently waiting for it to be unlocked, so
697 * wake it up.
698 */
699 static void unlock_request(struct fuse_conn *fc, struct fuse_req *req)
700 {
701 if (req) {
702 spin_lock(&fc->lock);
703 req->locked = 0;
704 if (req->aborted)
705 wake_up(&req->waitq);
706 spin_unlock(&fc->lock);
707 }
708 }
709
710 struct fuse_copy_state {
711 struct fuse_conn *fc;
712 int write;
713 struct fuse_req *req;
714 const struct iovec *iov;
715 struct pipe_buffer *pipebufs;
716 struct pipe_buffer *currbuf;
717 struct pipe_inode_info *pipe;
718 unsigned long nr_segs;
719 unsigned long seglen;
720 unsigned long addr;
721 struct page *pg;
722 unsigned len;
723 unsigned offset;
724 unsigned move_pages:1;
725 };
726
727 static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
728 int write,
729 const struct iovec *iov, unsigned long nr_segs)
730 {
731 memset(cs, 0, sizeof(*cs));
732 cs->fc = fc;
733 cs->write = write;
734 cs->iov = iov;
735 cs->nr_segs = nr_segs;
736 }
737
738 /* Unmap and put previous page of userspace buffer */
739 static void fuse_copy_finish(struct fuse_copy_state *cs)
740 {
741 if (cs->currbuf) {
742 struct pipe_buffer *buf = cs->currbuf;
743
744 if (cs->write)
745 buf->len = PAGE_SIZE - cs->len;
746 cs->currbuf = NULL;
747 } else if (cs->pg) {
748 if (cs->write) {
749 flush_dcache_page(cs->pg);
750 set_page_dirty_lock(cs->pg);
751 }
752 put_page(cs->pg);
753 }
754 cs->pg = NULL;
755 }
756
757 /*
758 * Get another pagefull of userspace buffer, and map it to kernel
759 * address space, and lock request
760 */
761 static int fuse_copy_fill(struct fuse_copy_state *cs)
762 {
763 struct page *page;
764 int err;
765
766 unlock_request(cs->fc, cs->req);
767 fuse_copy_finish(cs);
768 if (cs->pipebufs) {
769 struct pipe_buffer *buf = cs->pipebufs;
770
771 if (!cs->write) {
772 err = buf->ops->confirm(cs->pipe, buf);
773 if (err)
774 return err;
775
776 BUG_ON(!cs->nr_segs);
777 cs->currbuf = buf;
778 cs->pg = buf->page;
779 cs->offset = buf->offset;
780 cs->len = buf->len;
781 cs->pipebufs++;
782 cs->nr_segs--;
783 } else {
784 if (cs->nr_segs == cs->pipe->buffers)
785 return -EIO;
786
787 page = alloc_page(GFP_HIGHUSER);
788 if (!page)
789 return -ENOMEM;
790
791 buf->page = page;
792 buf->offset = 0;
793 buf->len = 0;
794
795 cs->currbuf = buf;
796 cs->pg = page;
797 cs->offset = 0;
798 cs->len = PAGE_SIZE;
799 cs->pipebufs++;
800 cs->nr_segs++;
801 }
802 } else {
803 if (!cs->seglen) {
804 BUG_ON(!cs->nr_segs);
805 cs->seglen = cs->iov[0].iov_len;
806 cs->addr = (unsigned long) cs->iov[0].iov_base;
807 cs->iov++;
808 cs->nr_segs--;
809 }
810 err = get_user_pages_fast(cs->addr, 1, cs->write, &page);
811 if (err < 0)
812 return err;
813 BUG_ON(err != 1);
814 cs->pg = page;
815 cs->offset = cs->addr % PAGE_SIZE;
816 cs->len = min(PAGE_SIZE - cs->offset, cs->seglen);
817 cs->seglen -= cs->len;
818 cs->addr += cs->len;
819 }
820
821 return lock_request(cs->fc, cs->req);
822 }
823
824 /* Do as much copy to/from userspace buffer as we can */
825 static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
826 {
827 unsigned ncpy = min(*size, cs->len);
828 if (val) {
829 void *pgaddr = kmap_atomic(cs->pg);
830 void *buf = pgaddr + cs->offset;
831
832 if (cs->write)
833 memcpy(buf, *val, ncpy);
834 else
835 memcpy(*val, buf, ncpy);
836
837 kunmap_atomic(pgaddr);
838 *val += ncpy;
839 }
840 *size -= ncpy;
841 cs->len -= ncpy;
842 cs->offset += ncpy;
843 return ncpy;
844 }
845
846 static int fuse_check_page(struct page *page)
847 {
848 if (page_mapcount(page) ||
849 page->mapping != NULL ||
850 page_count(page) != 1 ||
851 (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
852 ~(1 << PG_locked |
853 1 << PG_referenced |
854 1 << PG_uptodate |
855 1 << PG_lru |
856 1 << PG_active |
857 1 << PG_reclaim))) {
858 printk(KERN_WARNING "fuse: trying to steal weird page\n");
859 printk(KERN_WARNING " page=%p index=%li flags=%08lx, count=%i, mapcount=%i, mapping=%p\n", page, page->index, page->flags, page_count(page), page_mapcount(page), page->mapping);
860 return 1;
861 }
862 return 0;
863 }
864
865 static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
866 {
867 int err;
868 struct page *oldpage = *pagep;
869 struct page *newpage;
870 struct pipe_buffer *buf = cs->pipebufs;
871
872 unlock_request(cs->fc, cs->req);
873 fuse_copy_finish(cs);
874
875 err = buf->ops->confirm(cs->pipe, buf);
876 if (err)
877 return err;
878
879 BUG_ON(!cs->nr_segs);
880 cs->currbuf = buf;
881 cs->len = buf->len;
882 cs->pipebufs++;
883 cs->nr_segs--;
884
885 if (cs->len != PAGE_SIZE)
886 goto out_fallback;
887
888 if (buf->ops->steal(cs->pipe, buf) != 0)
889 goto out_fallback;
890
891 newpage = buf->page;
892
893 if (!PageUptodate(newpage))
894 SetPageUptodate(newpage);
895
896 ClearPageMappedToDisk(newpage);
897
898 if (fuse_check_page(newpage) != 0)
899 goto out_fallback_unlock;
900
901 /*
902 * This is a new and locked page, it shouldn't be mapped or
903 * have any special flags on it
904 */
905 if (WARN_ON(page_mapped(oldpage)))
906 goto out_fallback_unlock;
907 if (WARN_ON(page_has_private(oldpage)))
908 goto out_fallback_unlock;
909 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
910 goto out_fallback_unlock;
911 if (WARN_ON(PageMlocked(oldpage)))
912 goto out_fallback_unlock;
913
914 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
915 if (err) {
916 unlock_page(newpage);
917 return err;
918 }
919
920 page_cache_get(newpage);
921
922 if (!(buf->flags & PIPE_BUF_FLAG_LRU))
923 lru_cache_add_file(newpage);
924
925 err = 0;
926 spin_lock(&cs->fc->lock);
927 if (cs->req->aborted)
928 err = -ENOENT;
929 else
930 *pagep = newpage;
931 spin_unlock(&cs->fc->lock);
932
933 if (err) {
934 unlock_page(newpage);
935 page_cache_release(newpage);
936 return err;
937 }
938
939 unlock_page(oldpage);
940 page_cache_release(oldpage);
941 cs->len = 0;
942
943 return 0;
944
945 out_fallback_unlock:
946 unlock_page(newpage);
947 out_fallback:
948 cs->pg = buf->page;
949 cs->offset = buf->offset;
950
951 err = lock_request(cs->fc, cs->req);
952 if (err)
953 return err;
954
955 return 1;
956 }
957
958 static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
959 unsigned offset, unsigned count)
960 {
961 struct pipe_buffer *buf;
962
963 if (cs->nr_segs == cs->pipe->buffers)
964 return -EIO;
965
966 unlock_request(cs->fc, cs->req);
967 fuse_copy_finish(cs);
968
969 buf = cs->pipebufs;
970 page_cache_get(page);
971 buf->page = page;
972 buf->offset = offset;
973 buf->len = count;
974
975 cs->pipebufs++;
976 cs->nr_segs++;
977 cs->len = 0;
978
979 return 0;
980 }
981
982 /*
983 * Copy a page in the request to/from the userspace buffer. Must be
984 * done atomically
985 */
986 static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
987 unsigned offset, unsigned count, int zeroing)
988 {
989 int err;
990 struct page *page = *pagep;
991
992 if (page && zeroing && count < PAGE_SIZE)
993 clear_highpage(page);
994
995 while (count) {
996 if (cs->write && cs->pipebufs && page) {
997 return fuse_ref_page(cs, page, offset, count);
998 } else if (!cs->len) {
999 if (cs->move_pages && page &&
1000 offset == 0 && count == PAGE_SIZE) {
1001 err = fuse_try_move_page(cs, pagep);
1002 if (err <= 0)
1003 return err;
1004 } else {
1005 err = fuse_copy_fill(cs);
1006 if (err)
1007 return err;
1008 }
1009 }
1010 if (page) {
1011 void *mapaddr = kmap_atomic(page);
1012 void *buf = mapaddr + offset;
1013 offset += fuse_copy_do(cs, &buf, &count);
1014 kunmap_atomic(mapaddr);
1015 } else
1016 offset += fuse_copy_do(cs, NULL, &count);
1017 }
1018 if (page && !cs->write)
1019 flush_dcache_page(page);
1020 return 0;
1021 }
1022
1023 /* Copy pages in the request to/from userspace buffer */
1024 static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
1025 int zeroing)
1026 {
1027 unsigned i;
1028 struct fuse_req *req = cs->req;
1029
1030 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
1031 int err;
1032 unsigned offset = req->page_descs[i].offset;
1033 unsigned count = min(nbytes, req->page_descs[i].length);
1034
1035 err = fuse_copy_page(cs, &req->pages[i], offset, count,
1036 zeroing);
1037 if (err)
1038 return err;
1039
1040 nbytes -= count;
1041 }
1042 return 0;
1043 }
1044
1045 /* Copy a single argument in the request to/from userspace buffer */
1046 static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
1047 {
1048 while (size) {
1049 if (!cs->len) {
1050 int err = fuse_copy_fill(cs);
1051 if (err)
1052 return err;
1053 }
1054 fuse_copy_do(cs, &val, &size);
1055 }
1056 return 0;
1057 }
1058
1059 /* Copy request arguments to/from userspace buffer */
1060 static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
1061 unsigned argpages, struct fuse_arg *args,
1062 int zeroing)
1063 {
1064 int err = 0;
1065 unsigned i;
1066
1067 for (i = 0; !err && i < numargs; i++) {
1068 struct fuse_arg *arg = &args[i];
1069 if (i == numargs - 1 && argpages)
1070 err = fuse_copy_pages(cs, arg->size, zeroing);
1071 else
1072 err = fuse_copy_one(cs, arg->value, arg->size);
1073 }
1074 return err;
1075 }
1076
1077 static int forget_pending(struct fuse_conn *fc)
1078 {
1079 return fc->forget_list_head.next != NULL;
1080 }
1081
1082 static int request_pending(struct fuse_conn *fc)
1083 {
1084 return !list_empty(&fc->pending) || !list_empty(&fc->interrupts) ||
1085 forget_pending(fc);
1086 }
1087
1088 /* Wait until a request is available on the pending list */
1089 static void request_wait(struct fuse_conn *fc)
1090 __releases(fc->lock)
1091 __acquires(fc->lock)
1092 {
1093 DECLARE_WAITQUEUE(wait, current);
1094
1095 add_wait_queue_exclusive(&fc->waitq, &wait);
1096 while (fc->connected && !request_pending(fc)) {
1097 set_current_state(TASK_INTERRUPTIBLE);
1098 if (signal_pending(current))
1099 break;
1100
1101 spin_unlock(&fc->lock);
1102 schedule();
1103 spin_lock(&fc->lock);
1104 }
1105 set_current_state(TASK_RUNNING);
1106 remove_wait_queue(&fc->waitq, &wait);
1107 }
1108
1109 /*
1110 * Transfer an interrupt request to userspace
1111 *
1112 * Unlike other requests this is assembled on demand, without a need
1113 * to allocate a separate fuse_req structure.
1114 *
1115 * Called with fc->lock held, releases it
1116 */
1117 static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_copy_state *cs,
1118 size_t nbytes, struct fuse_req *req)
1119 __releases(fc->lock)
1120 {
1121 struct fuse_in_header ih;
1122 struct fuse_interrupt_in arg;
1123 unsigned reqsize = sizeof(ih) + sizeof(arg);
1124 int err;
1125
1126 list_del_init(&req->intr_entry);
1127 req->intr_unique = fuse_get_unique(fc);
1128 memset(&ih, 0, sizeof(ih));
1129 memset(&arg, 0, sizeof(arg));
1130 ih.len = reqsize;
1131 ih.opcode = FUSE_INTERRUPT;
1132 ih.unique = req->intr_unique;
1133 arg.unique = req->in.h.unique;
1134
1135 spin_unlock(&fc->lock);
1136 if (nbytes < reqsize)
1137 return -EINVAL;
1138
1139 err = fuse_copy_one(cs, &ih, sizeof(ih));
1140 if (!err)
1141 err = fuse_copy_one(cs, &arg, sizeof(arg));
1142 fuse_copy_finish(cs);
1143
1144 return err ? err : reqsize;
1145 }
1146
1147 static struct fuse_forget_link *dequeue_forget(struct fuse_conn *fc,
1148 unsigned max,
1149 unsigned *countp)
1150 {
1151 struct fuse_forget_link *head = fc->forget_list_head.next;
1152 struct fuse_forget_link **newhead = &head;
1153 unsigned count;
1154
1155 for (count = 0; *newhead != NULL && count < max; count++)
1156 newhead = &(*newhead)->next;
1157
1158 fc->forget_list_head.next = *newhead;
1159 *newhead = NULL;
1160 if (fc->forget_list_head.next == NULL)
1161 fc->forget_list_tail = &fc->forget_list_head;
1162
1163 if (countp != NULL)
1164 *countp = count;
1165
1166 return head;
1167 }
1168
1169 static int fuse_read_single_forget(struct fuse_conn *fc,
1170 struct fuse_copy_state *cs,
1171 size_t nbytes)
1172 __releases(fc->lock)
1173 {
1174 int err;
1175 struct fuse_forget_link *forget = dequeue_forget(fc, 1, NULL);
1176 struct fuse_forget_in arg = {
1177 .nlookup = forget->forget_one.nlookup,
1178 };
1179 struct fuse_in_header ih = {
1180 .opcode = FUSE_FORGET,
1181 .nodeid = forget->forget_one.nodeid,
1182 .unique = fuse_get_unique(fc),
1183 .len = sizeof(ih) + sizeof(arg),
1184 };
1185
1186 spin_unlock(&fc->lock);
1187 kfree(forget);
1188 if (nbytes < ih.len)
1189 return -EINVAL;
1190
1191 err = fuse_copy_one(cs, &ih, sizeof(ih));
1192 if (!err)
1193 err = fuse_copy_one(cs, &arg, sizeof(arg));
1194 fuse_copy_finish(cs);
1195
1196 if (err)
1197 return err;
1198
1199 return ih.len;
1200 }
1201
1202 static int fuse_read_batch_forget(struct fuse_conn *fc,
1203 struct fuse_copy_state *cs, size_t nbytes)
1204 __releases(fc->lock)
1205 {
1206 int err;
1207 unsigned max_forgets;
1208 unsigned count;
1209 struct fuse_forget_link *head;
1210 struct fuse_batch_forget_in arg = { .count = 0 };
1211 struct fuse_in_header ih = {
1212 .opcode = FUSE_BATCH_FORGET,
1213 .unique = fuse_get_unique(fc),
1214 .len = sizeof(ih) + sizeof(arg),
1215 };
1216
1217 if (nbytes < ih.len) {
1218 spin_unlock(&fc->lock);
1219 return -EINVAL;
1220 }
1221
1222 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
1223 head = dequeue_forget(fc, max_forgets, &count);
1224 spin_unlock(&fc->lock);
1225
1226 arg.count = count;
1227 ih.len += count * sizeof(struct fuse_forget_one);
1228 err = fuse_copy_one(cs, &ih, sizeof(ih));
1229 if (!err)
1230 err = fuse_copy_one(cs, &arg, sizeof(arg));
1231
1232 while (head) {
1233 struct fuse_forget_link *forget = head;
1234
1235 if (!err) {
1236 err = fuse_copy_one(cs, &forget->forget_one,
1237 sizeof(forget->forget_one));
1238 }
1239 head = forget->next;
1240 kfree(forget);
1241 }
1242
1243 fuse_copy_finish(cs);
1244
1245 if (err)
1246 return err;
1247
1248 return ih.len;
1249 }
1250
1251 static int fuse_read_forget(struct fuse_conn *fc, struct fuse_copy_state *cs,
1252 size_t nbytes)
1253 __releases(fc->lock)
1254 {
1255 if (fc->minor < 16 || fc->forget_list_head.next->next == NULL)
1256 return fuse_read_single_forget(fc, cs, nbytes);
1257 else
1258 return fuse_read_batch_forget(fc, cs, nbytes);
1259 }
1260
1261 /*
1262 * Read a single request into the userspace filesystem's buffer. This
1263 * function waits until a request is available, then removes it from
1264 * the pending list and copies request data to userspace buffer. If
1265 * no reply is needed (FORGET) or request has been aborted or there
1266 * was an error during the copying then it's finished by calling
1267 * request_end(). Otherwise add it to the processing list, and set
1268 * the 'sent' flag.
1269 */
1270 static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
1271 struct fuse_copy_state *cs, size_t nbytes)
1272 {
1273 int err;
1274 struct fuse_req *req;
1275 struct fuse_in *in;
1276 unsigned reqsize;
1277
1278 restart:
1279 spin_lock(&fc->lock);
1280 err = -EAGAIN;
1281 if ((file->f_flags & O_NONBLOCK) && fc->connected &&
1282 !request_pending(fc))
1283 goto err_unlock;
1284
1285 request_wait(fc);
1286 err = -ENODEV;
1287 if (!fc->connected)
1288 goto err_unlock;
1289 err = -ERESTARTSYS;
1290 if (!request_pending(fc))
1291 goto err_unlock;
1292
1293 if (!list_empty(&fc->interrupts)) {
1294 req = list_entry(fc->interrupts.next, struct fuse_req,
1295 intr_entry);
1296 return fuse_read_interrupt(fc, cs, nbytes, req);
1297 }
1298
1299 if (forget_pending(fc)) {
1300 if (list_empty(&fc->pending) || fc->forget_batch-- > 0)
1301 return fuse_read_forget(fc, cs, nbytes);
1302
1303 if (fc->forget_batch <= -8)
1304 fc->forget_batch = 16;
1305 }
1306
1307 req = list_entry(fc->pending.next, struct fuse_req, list);
1308 req->state = FUSE_REQ_READING;
1309 list_move(&req->list, &fc->io);
1310
1311 in = &req->in;
1312 reqsize = in->h.len;
1313 /* If request is too large, reply with an error and restart the read */
1314 if (nbytes < reqsize) {
1315 req->out.h.error = -EIO;
1316 /* SETXATTR is special, since it may contain too large data */
1317 if (in->h.opcode == FUSE_SETXATTR)
1318 req->out.h.error = -E2BIG;
1319 request_end(fc, req);
1320 goto restart;
1321 }
1322 spin_unlock(&fc->lock);
1323 cs->req = req;
1324 err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1325 if (!err)
1326 err = fuse_copy_args(cs, in->numargs, in->argpages,
1327 (struct fuse_arg *) in->args, 0);
1328 fuse_copy_finish(cs);
1329 spin_lock(&fc->lock);
1330 req->locked = 0;
1331 if (req->aborted) {
1332 request_end(fc, req);
1333 return -ENODEV;
1334 }
1335 if (err) {
1336 req->out.h.error = -EIO;
1337 request_end(fc, req);
1338 return err;
1339 }
1340 if (!req->isreply)
1341 request_end(fc, req);
1342 else {
1343 req->state = FUSE_REQ_SENT;
1344 list_move_tail(&req->list, &fc->processing);
1345 if (req->interrupted)
1346 queue_interrupt(fc, req);
1347 spin_unlock(&fc->lock);
1348 }
1349 return reqsize;
1350
1351 err_unlock:
1352 spin_unlock(&fc->lock);
1353 return err;
1354 }
1355
1356 static int fuse_dev_open(struct inode *inode, struct file *file)
1357 {
1358 /*
1359 * The fuse device's file's private_data is used to hold
1360 * the fuse_conn(ection) when it is mounted, and is used to
1361 * keep track of whether the file has been mounted already.
1362 */
1363 file->private_data = NULL;
1364 return 0;
1365 }
1366
1367 static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
1368 unsigned long nr_segs, loff_t pos)
1369 {
1370 struct fuse_copy_state cs;
1371 struct file *file = iocb->ki_filp;
1372 struct fuse_conn *fc = fuse_get_conn(file);
1373 if (!fc)
1374 return -EPERM;
1375
1376 fuse_copy_init(&cs, fc, 1, iov, nr_segs);
1377
1378 return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
1379 }
1380
1381 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1382 struct pipe_inode_info *pipe,
1383 size_t len, unsigned int flags)
1384 {
1385 int ret;
1386 int page_nr = 0;
1387 int do_wakeup = 0;
1388 struct pipe_buffer *bufs;
1389 struct fuse_copy_state cs;
1390 struct fuse_conn *fc = fuse_get_conn(in);
1391 if (!fc)
1392 return -EPERM;
1393
1394 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1395 if (!bufs)
1396 return -ENOMEM;
1397
1398 fuse_copy_init(&cs, fc, 1, NULL, 0);
1399 cs.pipebufs = bufs;
1400 cs.pipe = pipe;
1401 ret = fuse_dev_do_read(fc, in, &cs, len);
1402 if (ret < 0)
1403 goto out;
1404
1405 ret = 0;
1406 pipe_lock(pipe);
1407
1408 if (!pipe->readers) {
1409 send_sig(SIGPIPE, current, 0);
1410 if (!ret)
1411 ret = -EPIPE;
1412 goto out_unlock;
1413 }
1414
1415 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1416 ret = -EIO;
1417 goto out_unlock;
1418 }
1419
1420 while (page_nr < cs.nr_segs) {
1421 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
1422 struct pipe_buffer *buf = pipe->bufs + newbuf;
1423
1424 buf->page = bufs[page_nr].page;
1425 buf->offset = bufs[page_nr].offset;
1426 buf->len = bufs[page_nr].len;
1427 /*
1428 * Need to be careful about this. Having buf->ops in module
1429 * code can Oops if the buffer persists after module unload.
1430 */
1431 buf->ops = &nosteal_pipe_buf_ops;
1432
1433 pipe->nrbufs++;
1434 page_nr++;
1435 ret += buf->len;
1436
1437 if (pipe->files)
1438 do_wakeup = 1;
1439 }
1440
1441 out_unlock:
1442 pipe_unlock(pipe);
1443
1444 if (do_wakeup) {
1445 smp_mb();
1446 if (waitqueue_active(&pipe->wait))
1447 wake_up_interruptible(&pipe->wait);
1448 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
1449 }
1450
1451 out:
1452 for (; page_nr < cs.nr_segs; page_nr++)
1453 page_cache_release(bufs[page_nr].page);
1454
1455 kfree(bufs);
1456 return ret;
1457 }
1458
1459 static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1460 struct fuse_copy_state *cs)
1461 {
1462 struct fuse_notify_poll_wakeup_out outarg;
1463 int err = -EINVAL;
1464
1465 if (size != sizeof(outarg))
1466 goto err;
1467
1468 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1469 if (err)
1470 goto err;
1471
1472 fuse_copy_finish(cs);
1473 return fuse_notify_poll_wakeup(fc, &outarg);
1474
1475 err:
1476 fuse_copy_finish(cs);
1477 return err;
1478 }
1479
1480 static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1481 struct fuse_copy_state *cs)
1482 {
1483 struct fuse_notify_inval_inode_out outarg;
1484 int err = -EINVAL;
1485
1486 if (size != sizeof(outarg))
1487 goto err;
1488
1489 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1490 if (err)
1491 goto err;
1492 fuse_copy_finish(cs);
1493
1494 down_read(&fc->killsb);
1495 err = -ENOENT;
1496 if (fc->sb) {
1497 err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1498 outarg.off, outarg.len);
1499 }
1500 up_read(&fc->killsb);
1501 return err;
1502
1503 err:
1504 fuse_copy_finish(cs);
1505 return err;
1506 }
1507
1508 static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1509 struct fuse_copy_state *cs)
1510 {
1511 struct fuse_notify_inval_entry_out outarg;
1512 int err = -ENOMEM;
1513 char *buf;
1514 struct qstr name;
1515
1516 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1517 if (!buf)
1518 goto err;
1519
1520 err = -EINVAL;
1521 if (size < sizeof(outarg))
1522 goto err;
1523
1524 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1525 if (err)
1526 goto err;
1527
1528 err = -ENAMETOOLONG;
1529 if (outarg.namelen > FUSE_NAME_MAX)
1530 goto err;
1531
1532 err = -EINVAL;
1533 if (size != sizeof(outarg) + outarg.namelen + 1)
1534 goto err;
1535
1536 name.name = buf;
1537 name.len = outarg.namelen;
1538 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1539 if (err)
1540 goto err;
1541 fuse_copy_finish(cs);
1542 buf[outarg.namelen] = 0;
1543 name.hash = full_name_hash(name.name, name.len);
1544
1545 down_read(&fc->killsb);
1546 err = -ENOENT;
1547 if (fc->sb)
1548 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1549 up_read(&fc->killsb);
1550 kfree(buf);
1551 return err;
1552
1553 err:
1554 kfree(buf);
1555 fuse_copy_finish(cs);
1556 return err;
1557 }
1558
1559 static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1560 struct fuse_copy_state *cs)
1561 {
1562 struct fuse_notify_delete_out outarg;
1563 int err = -ENOMEM;
1564 char *buf;
1565 struct qstr name;
1566
1567 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1568 if (!buf)
1569 goto err;
1570
1571 err = -EINVAL;
1572 if (size < sizeof(outarg))
1573 goto err;
1574
1575 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1576 if (err)
1577 goto err;
1578
1579 err = -ENAMETOOLONG;
1580 if (outarg.namelen > FUSE_NAME_MAX)
1581 goto err;
1582
1583 err = -EINVAL;
1584 if (size != sizeof(outarg) + outarg.namelen + 1)
1585 goto err;
1586
1587 name.name = buf;
1588 name.len = outarg.namelen;
1589 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1590 if (err)
1591 goto err;
1592 fuse_copy_finish(cs);
1593 buf[outarg.namelen] = 0;
1594 name.hash = full_name_hash(name.name, name.len);
1595
1596 down_read(&fc->killsb);
1597 err = -ENOENT;
1598 if (fc->sb)
1599 err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1600 outarg.child, &name);
1601 up_read(&fc->killsb);
1602 kfree(buf);
1603 return err;
1604
1605 err:
1606 kfree(buf);
1607 fuse_copy_finish(cs);
1608 return err;
1609 }
1610
1611 static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1612 struct fuse_copy_state *cs)
1613 {
1614 struct fuse_notify_store_out outarg;
1615 struct inode *inode;
1616 struct address_space *mapping;
1617 u64 nodeid;
1618 int err;
1619 pgoff_t index;
1620 unsigned int offset;
1621 unsigned int num;
1622 loff_t file_size;
1623 loff_t end;
1624
1625 err = -EINVAL;
1626 if (size < sizeof(outarg))
1627 goto out_finish;
1628
1629 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1630 if (err)
1631 goto out_finish;
1632
1633 err = -EINVAL;
1634 if (size - sizeof(outarg) != outarg.size)
1635 goto out_finish;
1636
1637 nodeid = outarg.nodeid;
1638
1639 down_read(&fc->killsb);
1640
1641 err = -ENOENT;
1642 if (!fc->sb)
1643 goto out_up_killsb;
1644
1645 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1646 if (!inode)
1647 goto out_up_killsb;
1648
1649 mapping = inode->i_mapping;
1650 index = outarg.offset >> PAGE_CACHE_SHIFT;
1651 offset = outarg.offset & ~PAGE_CACHE_MASK;
1652 file_size = i_size_read(inode);
1653 end = outarg.offset + outarg.size;
1654 if (end > file_size) {
1655 file_size = end;
1656 fuse_write_update_size(inode, file_size);
1657 }
1658
1659 num = outarg.size;
1660 while (num) {
1661 struct page *page;
1662 unsigned int this_num;
1663
1664 err = -ENOMEM;
1665 page = find_or_create_page(mapping, index,
1666 mapping_gfp_mask(mapping));
1667 if (!page)
1668 goto out_iput;
1669
1670 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1671 err = fuse_copy_page(cs, &page, offset, this_num, 0);
1672 if (!err && offset == 0 &&
1673 (this_num == PAGE_CACHE_SIZE || file_size == end))
1674 SetPageUptodate(page);
1675 unlock_page(page);
1676 page_cache_release(page);
1677
1678 if (err)
1679 goto out_iput;
1680
1681 num -= this_num;
1682 offset = 0;
1683 index++;
1684 }
1685
1686 err = 0;
1687
1688 out_iput:
1689 iput(inode);
1690 out_up_killsb:
1691 up_read(&fc->killsb);
1692 out_finish:
1693 fuse_copy_finish(cs);
1694 return err;
1695 }
1696
1697 static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
1698 {
1699 release_pages(req->pages, req->num_pages, false);
1700 }
1701
1702 static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1703 struct fuse_notify_retrieve_out *outarg)
1704 {
1705 int err;
1706 struct address_space *mapping = inode->i_mapping;
1707 struct fuse_req *req;
1708 pgoff_t index;
1709 loff_t file_size;
1710 unsigned int num;
1711 unsigned int offset;
1712 size_t total_len = 0;
1713 int num_pages;
1714
1715 offset = outarg->offset & ~PAGE_CACHE_MASK;
1716 file_size = i_size_read(inode);
1717
1718 num = outarg->size;
1719 if (outarg->offset > file_size)
1720 num = 0;
1721 else if (outarg->offset + num > file_size)
1722 num = file_size - outarg->offset;
1723
1724 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1725 num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
1726
1727 req = fuse_get_req(fc, num_pages);
1728 if (IS_ERR(req))
1729 return PTR_ERR(req);
1730
1731 req->in.h.opcode = FUSE_NOTIFY_REPLY;
1732 req->in.h.nodeid = outarg->nodeid;
1733 req->in.numargs = 2;
1734 req->in.argpages = 1;
1735 req->page_descs[0].offset = offset;
1736 req->end = fuse_retrieve_end;
1737
1738 index = outarg->offset >> PAGE_CACHE_SHIFT;
1739
1740 while (num && req->num_pages < num_pages) {
1741 struct page *page;
1742 unsigned int this_num;
1743
1744 page = find_get_page(mapping, index);
1745 if (!page)
1746 break;
1747
1748 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1749 req->pages[req->num_pages] = page;
1750 req->page_descs[req->num_pages].length = this_num;
1751 req->num_pages++;
1752
1753 offset = 0;
1754 num -= this_num;
1755 total_len += this_num;
1756 index++;
1757 }
1758 req->misc.retrieve_in.offset = outarg->offset;
1759 req->misc.retrieve_in.size = total_len;
1760 req->in.args[0].size = sizeof(req->misc.retrieve_in);
1761 req->in.args[0].value = &req->misc.retrieve_in;
1762 req->in.args[1].size = total_len;
1763
1764 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1765 if (err)
1766 fuse_retrieve_end(fc, req);
1767
1768 return err;
1769 }
1770
1771 static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1772 struct fuse_copy_state *cs)
1773 {
1774 struct fuse_notify_retrieve_out outarg;
1775 struct inode *inode;
1776 int err;
1777
1778 err = -EINVAL;
1779 if (size != sizeof(outarg))
1780 goto copy_finish;
1781
1782 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1783 if (err)
1784 goto copy_finish;
1785
1786 fuse_copy_finish(cs);
1787
1788 down_read(&fc->killsb);
1789 err = -ENOENT;
1790 if (fc->sb) {
1791 u64 nodeid = outarg.nodeid;
1792
1793 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1794 if (inode) {
1795 err = fuse_retrieve(fc, inode, &outarg);
1796 iput(inode);
1797 }
1798 }
1799 up_read(&fc->killsb);
1800
1801 return err;
1802
1803 copy_finish:
1804 fuse_copy_finish(cs);
1805 return err;
1806 }
1807
1808 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1809 unsigned int size, struct fuse_copy_state *cs)
1810 {
1811 /* Don't try to move pages (yet) */
1812 cs->move_pages = 0;
1813
1814 switch (code) {
1815 case FUSE_NOTIFY_POLL:
1816 return fuse_notify_poll(fc, size, cs);
1817
1818 case FUSE_NOTIFY_INVAL_INODE:
1819 return fuse_notify_inval_inode(fc, size, cs);
1820
1821 case FUSE_NOTIFY_INVAL_ENTRY:
1822 return fuse_notify_inval_entry(fc, size, cs);
1823
1824 case FUSE_NOTIFY_STORE:
1825 return fuse_notify_store(fc, size, cs);
1826
1827 case FUSE_NOTIFY_RETRIEVE:
1828 return fuse_notify_retrieve(fc, size, cs);
1829
1830 case FUSE_NOTIFY_DELETE:
1831 return fuse_notify_delete(fc, size, cs);
1832
1833 default:
1834 fuse_copy_finish(cs);
1835 return -EINVAL;
1836 }
1837 }
1838
1839 /* Look up request on processing list by unique ID */
1840 static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
1841 {
1842 struct fuse_req *req;
1843
1844 list_for_each_entry(req, &fc->processing, list) {
1845 if (req->in.h.unique == unique || req->intr_unique == unique)
1846 return req;
1847 }
1848 return NULL;
1849 }
1850
1851 static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1852 unsigned nbytes)
1853 {
1854 unsigned reqsize = sizeof(struct fuse_out_header);
1855
1856 if (out->h.error)
1857 return nbytes != reqsize ? -EINVAL : 0;
1858
1859 reqsize += len_args(out->numargs, out->args);
1860
1861 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1862 return -EINVAL;
1863 else if (reqsize > nbytes) {
1864 struct fuse_arg *lastarg = &out->args[out->numargs-1];
1865 unsigned diffsize = reqsize - nbytes;
1866 if (diffsize > lastarg->size)
1867 return -EINVAL;
1868 lastarg->size -= diffsize;
1869 }
1870 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1871 out->page_zeroing);
1872 }
1873
1874 /*
1875 * Write a single reply to a request. First the header is copied from
1876 * the write buffer. The request is then searched on the processing
1877 * list by the unique ID found in the header. If found, then remove
1878 * it from the list and copy the rest of the buffer to the request.
1879 * The request is finished by calling request_end()
1880 */
1881 static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
1882 struct fuse_copy_state *cs, size_t nbytes)
1883 {
1884 int err;
1885 struct fuse_req *req;
1886 struct fuse_out_header oh;
1887
1888 if (nbytes < sizeof(struct fuse_out_header))
1889 return -EINVAL;
1890
1891 err = fuse_copy_one(cs, &oh, sizeof(oh));
1892 if (err)
1893 goto err_finish;
1894
1895 err = -EINVAL;
1896 if (oh.len != nbytes)
1897 goto err_finish;
1898
1899 /*
1900 * Zero oh.unique indicates unsolicited notification message
1901 * and error contains notification code.
1902 */
1903 if (!oh.unique) {
1904 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
1905 return err ? err : nbytes;
1906 }
1907
1908 err = -EINVAL;
1909 if (oh.error <= -1000 || oh.error > 0)
1910 goto err_finish;
1911
1912 spin_lock(&fc->lock);
1913 err = -ENOENT;
1914 if (!fc->connected)
1915 goto err_unlock;
1916
1917 req = request_find(fc, oh.unique);
1918 if (!req)
1919 goto err_unlock;
1920
1921 if (req->aborted) {
1922 spin_unlock(&fc->lock);
1923 fuse_copy_finish(cs);
1924 spin_lock(&fc->lock);
1925 request_end(fc, req);
1926 return -ENOENT;
1927 }
1928 /* Is it an interrupt reply? */
1929 if (req->intr_unique == oh.unique) {
1930 err = -EINVAL;
1931 if (nbytes != sizeof(struct fuse_out_header))
1932 goto err_unlock;
1933
1934 if (oh.error == -ENOSYS)
1935 fc->no_interrupt = 1;
1936 else if (oh.error == -EAGAIN)
1937 queue_interrupt(fc, req);
1938
1939 spin_unlock(&fc->lock);
1940 fuse_copy_finish(cs);
1941 return nbytes;
1942 }
1943
1944 req->state = FUSE_REQ_WRITING;
1945 list_move(&req->list, &fc->io);
1946 req->out.h = oh;
1947 req->locked = 1;
1948 cs->req = req;
1949 if (!req->out.page_replace)
1950 cs->move_pages = 0;
1951 spin_unlock(&fc->lock);
1952
1953 err = copy_out_args(cs, &req->out, nbytes);
1954 fuse_copy_finish(cs);
1955
1956 spin_lock(&fc->lock);
1957 req->locked = 0;
1958 if (!err) {
1959 if (req->aborted)
1960 err = -ENOENT;
1961 } else if (!req->aborted)
1962 req->out.h.error = -EIO;
1963 request_end(fc, req);
1964
1965 return err ? err : nbytes;
1966
1967 err_unlock:
1968 spin_unlock(&fc->lock);
1969 err_finish:
1970 fuse_copy_finish(cs);
1971 return err;
1972 }
1973
1974 static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
1975 unsigned long nr_segs, loff_t pos)
1976 {
1977 struct fuse_copy_state cs;
1978 struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
1979 if (!fc)
1980 return -EPERM;
1981
1982 fuse_copy_init(&cs, fc, 0, iov, nr_segs);
1983
1984 return fuse_dev_do_write(fc, &cs, iov_length(iov, nr_segs));
1985 }
1986
1987 static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1988 struct file *out, loff_t *ppos,
1989 size_t len, unsigned int flags)
1990 {
1991 unsigned nbuf;
1992 unsigned idx;
1993 struct pipe_buffer *bufs;
1994 struct fuse_copy_state cs;
1995 struct fuse_conn *fc;
1996 size_t rem;
1997 ssize_t ret;
1998
1999 fc = fuse_get_conn(out);
2000 if (!fc)
2001 return -EPERM;
2002
2003 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
2004 if (!bufs)
2005 return -ENOMEM;
2006
2007 pipe_lock(pipe);
2008 nbuf = 0;
2009 rem = 0;
2010 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
2011 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
2012
2013 ret = -EINVAL;
2014 if (rem < len) {
2015 pipe_unlock(pipe);
2016 goto out;
2017 }
2018
2019 rem = len;
2020 while (rem) {
2021 struct pipe_buffer *ibuf;
2022 struct pipe_buffer *obuf;
2023
2024 BUG_ON(nbuf >= pipe->buffers);
2025 BUG_ON(!pipe->nrbufs);
2026 ibuf = &pipe->bufs[pipe->curbuf];
2027 obuf = &bufs[nbuf];
2028
2029 if (rem >= ibuf->len) {
2030 *obuf = *ibuf;
2031 ibuf->ops = NULL;
2032 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
2033 pipe->nrbufs--;
2034 } else {
2035 ibuf->ops->get(pipe, ibuf);
2036 *obuf = *ibuf;
2037 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
2038 obuf->len = rem;
2039 ibuf->offset += obuf->len;
2040 ibuf->len -= obuf->len;
2041 }
2042 nbuf++;
2043 rem -= obuf->len;
2044 }
2045 pipe_unlock(pipe);
2046
2047 fuse_copy_init(&cs, fc, 0, NULL, nbuf);
2048 cs.pipebufs = bufs;
2049 cs.pipe = pipe;
2050
2051 if (flags & SPLICE_F_MOVE)
2052 cs.move_pages = 1;
2053
2054 ret = fuse_dev_do_write(fc, &cs, len);
2055
2056 for (idx = 0; idx < nbuf; idx++) {
2057 struct pipe_buffer *buf = &bufs[idx];
2058 buf->ops->release(pipe, buf);
2059 }
2060 out:
2061 kfree(bufs);
2062 return ret;
2063 }
2064
2065 static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
2066 {
2067 unsigned mask = POLLOUT | POLLWRNORM;
2068 struct fuse_conn *fc = fuse_get_conn(file);
2069 if (!fc)
2070 return POLLERR;
2071
2072 poll_wait(file, &fc->waitq, wait);
2073
2074 spin_lock(&fc->lock);
2075 if (!fc->connected)
2076 mask = POLLERR;
2077 else if (request_pending(fc))
2078 mask |= POLLIN | POLLRDNORM;
2079 spin_unlock(&fc->lock);
2080
2081 return mask;
2082 }
2083
2084 /*
2085 * Abort all requests on the given list (pending or processing)
2086 *
2087 * This function releases and reacquires fc->lock
2088 */
2089 static void end_requests(struct fuse_conn *fc, struct list_head *head)
2090 __releases(fc->lock)
2091 __acquires(fc->lock)
2092 {
2093 while (!list_empty(head)) {
2094 struct fuse_req *req;
2095 req = list_entry(head->next, struct fuse_req, list);
2096 req->out.h.error = -ECONNABORTED;
2097 request_end(fc, req);
2098 spin_lock(&fc->lock);
2099 }
2100 }
2101
2102 /*
2103 * Abort requests under I/O
2104 *
2105 * The requests are set to aborted and finished, and the request
2106 * waiter is woken up. This will make request_wait_answer() wait
2107 * until the request is unlocked and then return.
2108 *
2109 * If the request is asynchronous, then the end function needs to be
2110 * called after waiting for the request to be unlocked (if it was
2111 * locked).
2112 */
2113 static void end_io_requests(struct fuse_conn *fc)
2114 __releases(fc->lock)
2115 __acquires(fc->lock)
2116 {
2117 while (!list_empty(&fc->io)) {
2118 struct fuse_req *req =
2119 list_entry(fc->io.next, struct fuse_req, list);
2120 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
2121
2122 req->aborted = 1;
2123 req->out.h.error = -ECONNABORTED;
2124 req->state = FUSE_REQ_FINISHED;
2125 list_del_init(&req->list);
2126 wake_up(&req->waitq);
2127 if (end) {
2128 req->end = NULL;
2129 __fuse_get_request(req);
2130 spin_unlock(&fc->lock);
2131 wait_event(req->waitq, !req->locked);
2132 end(fc, req);
2133 fuse_put_request(fc, req);
2134 spin_lock(&fc->lock);
2135 }
2136 }
2137 }
2138
2139 static void end_queued_requests(struct fuse_conn *fc)
2140 __releases(fc->lock)
2141 __acquires(fc->lock)
2142 {
2143 fc->max_background = UINT_MAX;
2144 flush_bg_queue(fc);
2145 end_requests(fc, &fc->pending);
2146 end_requests(fc, &fc->processing);
2147 while (forget_pending(fc))
2148 kfree(dequeue_forget(fc, 1, NULL));
2149 }
2150
2151 static void end_polls(struct fuse_conn *fc)
2152 {
2153 struct rb_node *p;
2154
2155 p = rb_first(&fc->polled_files);
2156
2157 while (p) {
2158 struct fuse_file *ff;
2159 ff = rb_entry(p, struct fuse_file, polled_node);
2160 wake_up_interruptible_all(&ff->poll_wait);
2161
2162 p = rb_next(p);
2163 }
2164 }
2165
2166 /*
2167 * Abort all requests.
2168 *
2169 * Emergency exit in case of a malicious or accidental deadlock, or
2170 * just a hung filesystem.
2171 *
2172 * The same effect is usually achievable through killing the
2173 * filesystem daemon and all users of the filesystem. The exception
2174 * is the combination of an asynchronous request and the tricky
2175 * deadlock (see Documentation/filesystems/fuse.txt).
2176 *
2177 * During the aborting, progression of requests from the pending and
2178 * processing lists onto the io list, and progression of new requests
2179 * onto the pending list is prevented by req->connected being false.
2180 *
2181 * Progression of requests under I/O to the processing list is
2182 * prevented by the req->aborted flag being true for these requests.
2183 * For this reason requests on the io list must be aborted first.
2184 */
2185 void fuse_abort_conn(struct fuse_conn *fc)
2186 {
2187 spin_lock(&fc->lock);
2188 if (fc->connected) {
2189 fc->connected = 0;
2190 fc->blocked = 0;
2191 fuse_set_initialized(fc);
2192 end_io_requests(fc);
2193 end_queued_requests(fc);
2194 end_polls(fc);
2195 wake_up_all(&fc->waitq);
2196 wake_up_all(&fc->blocked_waitq);
2197 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
2198 }
2199 spin_unlock(&fc->lock);
2200 }
2201 EXPORT_SYMBOL_GPL(fuse_abort_conn);
2202
2203 int fuse_dev_release(struct inode *inode, struct file *file)
2204 {
2205 struct fuse_conn *fc = fuse_get_conn(file);
2206 if (fc) {
2207 spin_lock(&fc->lock);
2208 fc->connected = 0;
2209 fc->blocked = 0;
2210 fuse_set_initialized(fc);
2211 end_queued_requests(fc);
2212 end_polls(fc);
2213 wake_up_all(&fc->blocked_waitq);
2214 spin_unlock(&fc->lock);
2215 fuse_conn_put(fc);
2216 }
2217
2218 return 0;
2219 }
2220 EXPORT_SYMBOL_GPL(fuse_dev_release);
2221
2222 static int fuse_dev_fasync(int fd, struct file *file, int on)
2223 {
2224 struct fuse_conn *fc = fuse_get_conn(file);
2225 if (!fc)
2226 return -EPERM;
2227
2228 /* No locking - fasync_helper does its own locking */
2229 return fasync_helper(fd, file, on, &fc->fasync);
2230 }
2231
2232 const struct file_operations fuse_dev_operations = {
2233 .owner = THIS_MODULE,
2234 .open = fuse_dev_open,
2235 .llseek = no_llseek,
2236 .read = do_sync_read,
2237 .aio_read = fuse_dev_read,
2238 .splice_read = fuse_dev_splice_read,
2239 .write = do_sync_write,
2240 .aio_write = fuse_dev_write,
2241 .splice_write = fuse_dev_splice_write,
2242 .poll = fuse_dev_poll,
2243 .release = fuse_dev_release,
2244 .fasync = fuse_dev_fasync,
2245 };
2246 EXPORT_SYMBOL_GPL(fuse_dev_operations);
2247
2248 static struct miscdevice fuse_miscdevice = {
2249 .minor = FUSE_MINOR,
2250 .name = "fuse",
2251 .fops = &fuse_dev_operations,
2252 };
2253
2254 int __init fuse_dev_init(void)
2255 {
2256 int err = -ENOMEM;
2257 fuse_req_cachep = kmem_cache_create("fuse_request",
2258 sizeof(struct fuse_req),
2259 0, 0, NULL);
2260 if (!fuse_req_cachep)
2261 goto out;
2262
2263 err = misc_register(&fuse_miscdevice);
2264 if (err)
2265 goto out_cache_clean;
2266
2267 return 0;
2268
2269 out_cache_clean:
2270 kmem_cache_destroy(fuse_req_cachep);
2271 out:
2272 return err;
2273 }
2274
2275 void fuse_dev_cleanup(void)
2276 {
2277 misc_deregister(&fuse_miscdevice);
2278 kmem_cache_destroy(fuse_req_cachep);
2279 }
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