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