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fuse: add max_pages to init_out
[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/sched/signal.h>
15 #include <linux/uio.h>
16 #include <linux/miscdevice.h>
17 #include <linux/pagemap.h>
18 #include <linux/file.h>
19 #include <linux/slab.h>
20 #include <linux/pipe_fs_i.h>
21 #include <linux/swap.h>
22 #include <linux/splice.h>
23 #include <linux/sched.h>
24
25 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
26 MODULE_ALIAS("devname:fuse");
27
28 /* Ordinary requests have even IDs, while interrupts IDs are odd */
29 #define FUSE_INT_REQ_BIT (1ULL << 0)
30 #define FUSE_REQ_ID_STEP (1ULL << 1)
31
32 static struct kmem_cache *fuse_req_cachep;
33
34 static struct fuse_dev *fuse_get_dev(struct file *file)
35 {
36 /*
37 * Lockless access is OK, because file->private data is set
38 * once during mount and is valid until the file is released.
39 */
40 return READ_ONCE(file->private_data);
41 }
42
43 static void fuse_request_init(struct fuse_req *req, struct page **pages,
44 struct fuse_page_desc *page_descs,
45 unsigned npages)
46 {
47 INIT_LIST_HEAD(&req->list);
48 INIT_LIST_HEAD(&req->intr_entry);
49 init_waitqueue_head(&req->waitq);
50 refcount_set(&req->count, 1);
51 req->pages = pages;
52 req->page_descs = page_descs;
53 req->max_pages = npages;
54 __set_bit(FR_PENDING, &req->flags);
55 }
56
57 static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
58 {
59 struct fuse_req *req = kmem_cache_zalloc(fuse_req_cachep, flags);
60 if (req) {
61 struct page **pages = NULL;
62 struct fuse_page_desc *page_descs = NULL;
63
64 WARN_ON(npages > FUSE_MAX_MAX_PAGES);
65 if (npages > FUSE_REQ_INLINE_PAGES) {
66 pages = kzalloc(npages * (sizeof(*pages) +
67 sizeof(*page_descs)), flags);
68 if (!pages) {
69 kmem_cache_free(fuse_req_cachep, req);
70 return NULL;
71 }
72 page_descs = (void *) pages + npages * sizeof(*pages);
73 } else if (npages) {
74 pages = req->inline_pages;
75 page_descs = req->inline_page_descs;
76 }
77
78 fuse_request_init(req, pages, page_descs, npages);
79 }
80 return req;
81 }
82
83 struct fuse_req *fuse_request_alloc(unsigned npages)
84 {
85 return __fuse_request_alloc(npages, GFP_KERNEL);
86 }
87 EXPORT_SYMBOL_GPL(fuse_request_alloc);
88
89 struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
90 {
91 return __fuse_request_alloc(npages, GFP_NOFS);
92 }
93
94 void fuse_request_free(struct fuse_req *req)
95 {
96 if (req->pages != req->inline_pages)
97 kfree(req->pages);
98
99 kmem_cache_free(fuse_req_cachep, req);
100 }
101
102 void __fuse_get_request(struct fuse_req *req)
103 {
104 refcount_inc(&req->count);
105 }
106
107 /* Must be called with > 1 refcount */
108 static void __fuse_put_request(struct fuse_req *req)
109 {
110 refcount_dec(&req->count);
111 }
112
113 void fuse_set_initialized(struct fuse_conn *fc)
114 {
115 /* Make sure stores before this are seen on another CPU */
116 smp_wmb();
117 fc->initialized = 1;
118 }
119
120 static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
121 {
122 return !fc->initialized || (for_background && fc->blocked);
123 }
124
125 static void fuse_drop_waiting(struct fuse_conn *fc)
126 {
127 if (fc->connected) {
128 atomic_dec(&fc->num_waiting);
129 } else if (atomic_dec_and_test(&fc->num_waiting)) {
130 /* wake up aborters */
131 wake_up_all(&fc->blocked_waitq);
132 }
133 }
134
135 static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
136 bool for_background)
137 {
138 struct fuse_req *req;
139 int err;
140 atomic_inc(&fc->num_waiting);
141
142 if (fuse_block_alloc(fc, for_background)) {
143 err = -EINTR;
144 if (wait_event_killable_exclusive(fc->blocked_waitq,
145 !fuse_block_alloc(fc, for_background)))
146 goto out;
147 }
148 /* Matches smp_wmb() in fuse_set_initialized() */
149 smp_rmb();
150
151 err = -ENOTCONN;
152 if (!fc->connected)
153 goto out;
154
155 err = -ECONNREFUSED;
156 if (fc->conn_error)
157 goto out;
158
159 req = fuse_request_alloc(npages);
160 err = -ENOMEM;
161 if (!req) {
162 if (for_background)
163 wake_up(&fc->blocked_waitq);
164 goto out;
165 }
166
167 req->in.h.uid = from_kuid(fc->user_ns, current_fsuid());
168 req->in.h.gid = from_kgid(fc->user_ns, current_fsgid());
169 req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
170
171 __set_bit(FR_WAITING, &req->flags);
172 if (for_background)
173 __set_bit(FR_BACKGROUND, &req->flags);
174
175 if (unlikely(req->in.h.uid == ((uid_t)-1) ||
176 req->in.h.gid == ((gid_t)-1))) {
177 fuse_put_request(fc, req);
178 return ERR_PTR(-EOVERFLOW);
179 }
180 return req;
181
182 out:
183 fuse_drop_waiting(fc);
184 return ERR_PTR(err);
185 }
186
187 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
188 {
189 return __fuse_get_req(fc, npages, false);
190 }
191 EXPORT_SYMBOL_GPL(fuse_get_req);
192
193 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
194 unsigned npages)
195 {
196 return __fuse_get_req(fc, npages, true);
197 }
198 EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
199
200 /*
201 * Return request in fuse_file->reserved_req. However that may
202 * currently be in use. If that is the case, wait for it to become
203 * available.
204 */
205 static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
206 struct file *file)
207 {
208 struct fuse_req *req = NULL;
209 struct fuse_file *ff = file->private_data;
210
211 do {
212 wait_event(fc->reserved_req_waitq, ff->reserved_req);
213 spin_lock(&fc->lock);
214 if (ff->reserved_req) {
215 req = ff->reserved_req;
216 ff->reserved_req = NULL;
217 req->stolen_file = get_file(file);
218 }
219 spin_unlock(&fc->lock);
220 } while (!req);
221
222 return req;
223 }
224
225 /*
226 * Put stolen request back into fuse_file->reserved_req
227 */
228 static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
229 {
230 struct file *file = req->stolen_file;
231 struct fuse_file *ff = file->private_data;
232
233 WARN_ON(req->max_pages);
234 spin_lock(&fc->lock);
235 memset(req, 0, sizeof(*req));
236 fuse_request_init(req, NULL, NULL, 0);
237 BUG_ON(ff->reserved_req);
238 ff->reserved_req = req;
239 wake_up_all(&fc->reserved_req_waitq);
240 spin_unlock(&fc->lock);
241 fput(file);
242 }
243
244 /*
245 * Gets a requests for a file operation, always succeeds
246 *
247 * This is used for sending the FLUSH request, which must get to
248 * userspace, due to POSIX locks which may need to be unlocked.
249 *
250 * If allocation fails due to OOM, use the reserved request in
251 * fuse_file.
252 *
253 * This is very unlikely to deadlock accidentally, since the
254 * filesystem should not have it's own file open. If deadlock is
255 * intentional, it can still be broken by "aborting" the filesystem.
256 */
257 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
258 struct file *file)
259 {
260 struct fuse_req *req;
261
262 atomic_inc(&fc->num_waiting);
263 wait_event(fc->blocked_waitq, fc->initialized);
264 /* Matches smp_wmb() in fuse_set_initialized() */
265 smp_rmb();
266 req = fuse_request_alloc(0);
267 if (!req)
268 req = get_reserved_req(fc, file);
269
270 req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid());
271 req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid());
272 req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
273
274 __set_bit(FR_WAITING, &req->flags);
275 __clear_bit(FR_BACKGROUND, &req->flags);
276 return req;
277 }
278
279 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
280 {
281 if (refcount_dec_and_test(&req->count)) {
282 if (test_bit(FR_BACKGROUND, &req->flags)) {
283 /*
284 * We get here in the unlikely case that a background
285 * request was allocated but not sent
286 */
287 spin_lock(&fc->bg_lock);
288 if (!fc->blocked)
289 wake_up(&fc->blocked_waitq);
290 spin_unlock(&fc->bg_lock);
291 }
292
293 if (test_bit(FR_WAITING, &req->flags)) {
294 __clear_bit(FR_WAITING, &req->flags);
295 fuse_drop_waiting(fc);
296 }
297
298 if (req->stolen_file)
299 put_reserved_req(fc, req);
300 else
301 fuse_request_free(req);
302 }
303 }
304 EXPORT_SYMBOL_GPL(fuse_put_request);
305
306 static unsigned len_args(unsigned numargs, struct fuse_arg *args)
307 {
308 unsigned nbytes = 0;
309 unsigned i;
310
311 for (i = 0; i < numargs; i++)
312 nbytes += args[i].size;
313
314 return nbytes;
315 }
316
317 static u64 fuse_get_unique(struct fuse_iqueue *fiq)
318 {
319 fiq->reqctr += FUSE_REQ_ID_STEP;
320 return fiq->reqctr;
321 }
322
323 static unsigned int fuse_req_hash(u64 unique)
324 {
325 return hash_long(unique & ~FUSE_INT_REQ_BIT, FUSE_PQ_HASH_BITS);
326 }
327
328 static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
329 {
330 req->in.h.len = sizeof(struct fuse_in_header) +
331 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
332 list_add_tail(&req->list, &fiq->pending);
333 wake_up_locked(&fiq->waitq);
334 kill_fasync(&fiq->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 struct fuse_iqueue *fiq = &fc->iq;
341
342 forget->forget_one.nodeid = nodeid;
343 forget->forget_one.nlookup = nlookup;
344
345 spin_lock(&fiq->waitq.lock);
346 if (fiq->connected) {
347 fiq->forget_list_tail->next = forget;
348 fiq->forget_list_tail = forget;
349 wake_up_locked(&fiq->waitq);
350 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
351 } else {
352 kfree(forget);
353 }
354 spin_unlock(&fiq->waitq.lock);
355 }
356
357 static void flush_bg_queue(struct fuse_conn *fc)
358 {
359 struct fuse_iqueue *fiq = &fc->iq;
360
361 while (fc->active_background < fc->max_background &&
362 !list_empty(&fc->bg_queue)) {
363 struct fuse_req *req;
364
365 req = list_first_entry(&fc->bg_queue, struct fuse_req, list);
366 list_del(&req->list);
367 fc->active_background++;
368 spin_lock(&fiq->waitq.lock);
369 req->in.h.unique = fuse_get_unique(fiq);
370 queue_request(fiq, req);
371 spin_unlock(&fiq->waitq.lock);
372 }
373 }
374
375 /*
376 * This function is called when a request is finished. Either a reply
377 * has arrived or it was aborted (and not yet sent) or some error
378 * occurred during communication with userspace, or the device file
379 * was closed. The requester thread is woken up (if still waiting),
380 * the 'end' callback is called if given, else the reference to the
381 * request is released
382 */
383 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
384 {
385 struct fuse_iqueue *fiq = &fc->iq;
386
387 if (test_and_set_bit(FR_FINISHED, &req->flags))
388 goto put_request;
389
390 spin_lock(&fiq->waitq.lock);
391 list_del_init(&req->intr_entry);
392 spin_unlock(&fiq->waitq.lock);
393 WARN_ON(test_bit(FR_PENDING, &req->flags));
394 WARN_ON(test_bit(FR_SENT, &req->flags));
395 if (test_bit(FR_BACKGROUND, &req->flags)) {
396 spin_lock(&fc->bg_lock);
397 clear_bit(FR_BACKGROUND, &req->flags);
398 if (fc->num_background == fc->max_background) {
399 fc->blocked = 0;
400 wake_up(&fc->blocked_waitq);
401 } else if (!fc->blocked) {
402 /*
403 * Wake up next waiter, if any. It's okay to use
404 * waitqueue_active(), as we've already synced up
405 * fc->blocked with waiters with the wake_up() call
406 * above.
407 */
408 if (waitqueue_active(&fc->blocked_waitq))
409 wake_up(&fc->blocked_waitq);
410 }
411
412 if (fc->num_background == fc->congestion_threshold && fc->sb) {
413 clear_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
414 clear_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
415 }
416 fc->num_background--;
417 fc->active_background--;
418 flush_bg_queue(fc);
419 spin_unlock(&fc->bg_lock);
420 }
421 wake_up(&req->waitq);
422 if (req->end)
423 req->end(fc, req);
424 put_request:
425 fuse_put_request(fc, req);
426 }
427
428 static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
429 {
430 spin_lock(&fiq->waitq.lock);
431 if (test_bit(FR_FINISHED, &req->flags)) {
432 spin_unlock(&fiq->waitq.lock);
433 return;
434 }
435 if (list_empty(&req->intr_entry)) {
436 list_add_tail(&req->intr_entry, &fiq->interrupts);
437 wake_up_locked(&fiq->waitq);
438 }
439 spin_unlock(&fiq->waitq.lock);
440 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
441 }
442
443 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
444 {
445 struct fuse_iqueue *fiq = &fc->iq;
446 int err;
447
448 if (!fc->no_interrupt) {
449 /* Any signal may interrupt this */
450 err = wait_event_interruptible(req->waitq,
451 test_bit(FR_FINISHED, &req->flags));
452 if (!err)
453 return;
454
455 set_bit(FR_INTERRUPTED, &req->flags);
456 /* matches barrier in fuse_dev_do_read() */
457 smp_mb__after_atomic();
458 if (test_bit(FR_SENT, &req->flags))
459 queue_interrupt(fiq, req);
460 }
461
462 if (!test_bit(FR_FORCE, &req->flags)) {
463 /* Only fatal signals may interrupt this */
464 err = wait_event_killable(req->waitq,
465 test_bit(FR_FINISHED, &req->flags));
466 if (!err)
467 return;
468
469 spin_lock(&fiq->waitq.lock);
470 /* Request is not yet in userspace, bail out */
471 if (test_bit(FR_PENDING, &req->flags)) {
472 list_del(&req->list);
473 spin_unlock(&fiq->waitq.lock);
474 __fuse_put_request(req);
475 req->out.h.error = -EINTR;
476 return;
477 }
478 spin_unlock(&fiq->waitq.lock);
479 }
480
481 /*
482 * Either request is already in userspace, or it was forced.
483 * Wait it out.
484 */
485 wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
486 }
487
488 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
489 {
490 struct fuse_iqueue *fiq = &fc->iq;
491
492 BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
493 spin_lock(&fiq->waitq.lock);
494 if (!fiq->connected) {
495 spin_unlock(&fiq->waitq.lock);
496 req->out.h.error = -ENOTCONN;
497 } else {
498 req->in.h.unique = fuse_get_unique(fiq);
499 queue_request(fiq, req);
500 /* acquire extra reference, since request is still needed
501 after request_end() */
502 __fuse_get_request(req);
503 spin_unlock(&fiq->waitq.lock);
504
505 request_wait_answer(fc, req);
506 /* Pairs with smp_wmb() in request_end() */
507 smp_rmb();
508 }
509 }
510
511 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
512 {
513 __set_bit(FR_ISREPLY, &req->flags);
514 if (!test_bit(FR_WAITING, &req->flags)) {
515 __set_bit(FR_WAITING, &req->flags);
516 atomic_inc(&fc->num_waiting);
517 }
518 __fuse_request_send(fc, req);
519 }
520 EXPORT_SYMBOL_GPL(fuse_request_send);
521
522 static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
523 {
524 if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS)
525 args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE;
526
527 if (fc->minor < 9) {
528 switch (args->in.h.opcode) {
529 case FUSE_LOOKUP:
530 case FUSE_CREATE:
531 case FUSE_MKNOD:
532 case FUSE_MKDIR:
533 case FUSE_SYMLINK:
534 case FUSE_LINK:
535 args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
536 break;
537 case FUSE_GETATTR:
538 case FUSE_SETATTR:
539 args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
540 break;
541 }
542 }
543 if (fc->minor < 12) {
544 switch (args->in.h.opcode) {
545 case FUSE_CREATE:
546 args->in.args[0].size = sizeof(struct fuse_open_in);
547 break;
548 case FUSE_MKNOD:
549 args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
550 break;
551 }
552 }
553 }
554
555 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
556 {
557 struct fuse_req *req;
558 ssize_t ret;
559
560 req = fuse_get_req(fc, 0);
561 if (IS_ERR(req))
562 return PTR_ERR(req);
563
564 /* Needs to be done after fuse_get_req() so that fc->minor is valid */
565 fuse_adjust_compat(fc, args);
566
567 req->in.h.opcode = args->in.h.opcode;
568 req->in.h.nodeid = args->in.h.nodeid;
569 req->in.numargs = args->in.numargs;
570 memcpy(req->in.args, args->in.args,
571 args->in.numargs * sizeof(struct fuse_in_arg));
572 req->out.argvar = args->out.argvar;
573 req->out.numargs = args->out.numargs;
574 memcpy(req->out.args, args->out.args,
575 args->out.numargs * sizeof(struct fuse_arg));
576 fuse_request_send(fc, req);
577 ret = req->out.h.error;
578 if (!ret && args->out.argvar) {
579 BUG_ON(args->out.numargs != 1);
580 ret = req->out.args[0].size;
581 }
582 fuse_put_request(fc, req);
583
584 return ret;
585 }
586
587 bool fuse_request_queue_background(struct fuse_conn *fc, struct fuse_req *req)
588 {
589 bool queued = false;
590
591 WARN_ON(!test_bit(FR_BACKGROUND, &req->flags));
592 if (!test_bit(FR_WAITING, &req->flags)) {
593 __set_bit(FR_WAITING, &req->flags);
594 atomic_inc(&fc->num_waiting);
595 }
596 __set_bit(FR_ISREPLY, &req->flags);
597 spin_lock(&fc->bg_lock);
598 if (likely(fc->connected)) {
599 fc->num_background++;
600 if (fc->num_background == fc->max_background)
601 fc->blocked = 1;
602 if (fc->num_background == fc->congestion_threshold && fc->sb) {
603 set_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
604 set_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
605 }
606 list_add_tail(&req->list, &fc->bg_queue);
607 flush_bg_queue(fc);
608 queued = true;
609 }
610 spin_unlock(&fc->bg_lock);
611
612 return queued;
613 }
614
615 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
616 {
617 WARN_ON(!req->end);
618 if (!fuse_request_queue_background(fc, req)) {
619 req->out.h.error = -ENOTCONN;
620 req->end(fc, req);
621 fuse_put_request(fc, req);
622 }
623 }
624 EXPORT_SYMBOL_GPL(fuse_request_send_background);
625
626 static int fuse_request_send_notify_reply(struct fuse_conn *fc,
627 struct fuse_req *req, u64 unique)
628 {
629 int err = -ENODEV;
630 struct fuse_iqueue *fiq = &fc->iq;
631
632 __clear_bit(FR_ISREPLY, &req->flags);
633 req->in.h.unique = unique;
634 spin_lock(&fiq->waitq.lock);
635 if (fiq->connected) {
636 queue_request(fiq, req);
637 err = 0;
638 }
639 spin_unlock(&fiq->waitq.lock);
640
641 return err;
642 }
643
644 void fuse_force_forget(struct file *file, u64 nodeid)
645 {
646 struct inode *inode = file_inode(file);
647 struct fuse_conn *fc = get_fuse_conn(inode);
648 struct fuse_req *req;
649 struct fuse_forget_in inarg;
650
651 memset(&inarg, 0, sizeof(inarg));
652 inarg.nlookup = 1;
653 req = fuse_get_req_nofail_nopages(fc, file);
654 req->in.h.opcode = FUSE_FORGET;
655 req->in.h.nodeid = nodeid;
656 req->in.numargs = 1;
657 req->in.args[0].size = sizeof(inarg);
658 req->in.args[0].value = &inarg;
659 __clear_bit(FR_ISREPLY, &req->flags);
660 __fuse_request_send(fc, req);
661 /* ignore errors */
662 fuse_put_request(fc, req);
663 }
664
665 /*
666 * Lock the request. Up to the next unlock_request() there mustn't be
667 * anything that could cause a page-fault. If the request was already
668 * aborted bail out.
669 */
670 static int lock_request(struct fuse_req *req)
671 {
672 int err = 0;
673 if (req) {
674 spin_lock(&req->waitq.lock);
675 if (test_bit(FR_ABORTED, &req->flags))
676 err = -ENOENT;
677 else
678 set_bit(FR_LOCKED, &req->flags);
679 spin_unlock(&req->waitq.lock);
680 }
681 return err;
682 }
683
684 /*
685 * Unlock request. If it was aborted while locked, caller is responsible
686 * for unlocking and ending the request.
687 */
688 static int unlock_request(struct fuse_req *req)
689 {
690 int err = 0;
691 if (req) {
692 spin_lock(&req->waitq.lock);
693 if (test_bit(FR_ABORTED, &req->flags))
694 err = -ENOENT;
695 else
696 clear_bit(FR_LOCKED, &req->flags);
697 spin_unlock(&req->waitq.lock);
698 }
699 return err;
700 }
701
702 struct fuse_copy_state {
703 int write;
704 struct fuse_req *req;
705 struct iov_iter *iter;
706 struct pipe_buffer *pipebufs;
707 struct pipe_buffer *currbuf;
708 struct pipe_inode_info *pipe;
709 unsigned long nr_segs;
710 struct page *pg;
711 unsigned len;
712 unsigned offset;
713 unsigned move_pages:1;
714 };
715
716 static void fuse_copy_init(struct fuse_copy_state *cs, int write,
717 struct iov_iter *iter)
718 {
719 memset(cs, 0, sizeof(*cs));
720 cs->write = write;
721 cs->iter = iter;
722 }
723
724 /* Unmap and put previous page of userspace buffer */
725 static void fuse_copy_finish(struct fuse_copy_state *cs)
726 {
727 if (cs->currbuf) {
728 struct pipe_buffer *buf = cs->currbuf;
729
730 if (cs->write)
731 buf->len = PAGE_SIZE - cs->len;
732 cs->currbuf = NULL;
733 } else if (cs->pg) {
734 if (cs->write) {
735 flush_dcache_page(cs->pg);
736 set_page_dirty_lock(cs->pg);
737 }
738 put_page(cs->pg);
739 }
740 cs->pg = NULL;
741 }
742
743 /*
744 * Get another pagefull of userspace buffer, and map it to kernel
745 * address space, and lock request
746 */
747 static int fuse_copy_fill(struct fuse_copy_state *cs)
748 {
749 struct page *page;
750 int err;
751
752 err = unlock_request(cs->req);
753 if (err)
754 return err;
755
756 fuse_copy_finish(cs);
757 if (cs->pipebufs) {
758 struct pipe_buffer *buf = cs->pipebufs;
759
760 if (!cs->write) {
761 err = pipe_buf_confirm(cs->pipe, buf);
762 if (err)
763 return err;
764
765 BUG_ON(!cs->nr_segs);
766 cs->currbuf = buf;
767 cs->pg = buf->page;
768 cs->offset = buf->offset;
769 cs->len = buf->len;
770 cs->pipebufs++;
771 cs->nr_segs--;
772 } else {
773 if (cs->nr_segs == cs->pipe->buffers)
774 return -EIO;
775
776 page = alloc_page(GFP_HIGHUSER);
777 if (!page)
778 return -ENOMEM;
779
780 buf->page = page;
781 buf->offset = 0;
782 buf->len = 0;
783
784 cs->currbuf = buf;
785 cs->pg = page;
786 cs->offset = 0;
787 cs->len = PAGE_SIZE;
788 cs->pipebufs++;
789 cs->nr_segs++;
790 }
791 } else {
792 size_t off;
793 err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off);
794 if (err < 0)
795 return err;
796 BUG_ON(!err);
797 cs->len = err;
798 cs->offset = off;
799 cs->pg = page;
800 iov_iter_advance(cs->iter, err);
801 }
802
803 return lock_request(cs->req);
804 }
805
806 /* Do as much copy to/from userspace buffer as we can */
807 static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
808 {
809 unsigned ncpy = min(*size, cs->len);
810 if (val) {
811 void *pgaddr = kmap_atomic(cs->pg);
812 void *buf = pgaddr + cs->offset;
813
814 if (cs->write)
815 memcpy(buf, *val, ncpy);
816 else
817 memcpy(*val, buf, ncpy);
818
819 kunmap_atomic(pgaddr);
820 *val += ncpy;
821 }
822 *size -= ncpy;
823 cs->len -= ncpy;
824 cs->offset += ncpy;
825 return ncpy;
826 }
827
828 static int fuse_check_page(struct page *page)
829 {
830 if (page_mapcount(page) ||
831 page->mapping != NULL ||
832 page_count(page) != 1 ||
833 (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
834 ~(1 << PG_locked |
835 1 << PG_referenced |
836 1 << PG_uptodate |
837 1 << PG_lru |
838 1 << PG_active |
839 1 << PG_reclaim))) {
840 printk(KERN_WARNING "fuse: trying to steal weird page\n");
841 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);
842 return 1;
843 }
844 return 0;
845 }
846
847 static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
848 {
849 int err;
850 struct page *oldpage = *pagep;
851 struct page *newpage;
852 struct pipe_buffer *buf = cs->pipebufs;
853
854 err = unlock_request(cs->req);
855 if (err)
856 return err;
857
858 fuse_copy_finish(cs);
859
860 err = pipe_buf_confirm(cs->pipe, buf);
861 if (err)
862 return err;
863
864 BUG_ON(!cs->nr_segs);
865 cs->currbuf = buf;
866 cs->len = buf->len;
867 cs->pipebufs++;
868 cs->nr_segs--;
869
870 if (cs->len != PAGE_SIZE)
871 goto out_fallback;
872
873 if (pipe_buf_steal(cs->pipe, buf) != 0)
874 goto out_fallback;
875
876 newpage = buf->page;
877
878 if (!PageUptodate(newpage))
879 SetPageUptodate(newpage);
880
881 ClearPageMappedToDisk(newpage);
882
883 if (fuse_check_page(newpage) != 0)
884 goto out_fallback_unlock;
885
886 /*
887 * This is a new and locked page, it shouldn't be mapped or
888 * have any special flags on it
889 */
890 if (WARN_ON(page_mapped(oldpage)))
891 goto out_fallback_unlock;
892 if (WARN_ON(page_has_private(oldpage)))
893 goto out_fallback_unlock;
894 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
895 goto out_fallback_unlock;
896 if (WARN_ON(PageMlocked(oldpage)))
897 goto out_fallback_unlock;
898
899 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
900 if (err) {
901 unlock_page(newpage);
902 return err;
903 }
904
905 get_page(newpage);
906
907 if (!(buf->flags & PIPE_BUF_FLAG_LRU))
908 lru_cache_add_file(newpage);
909
910 err = 0;
911 spin_lock(&cs->req->waitq.lock);
912 if (test_bit(FR_ABORTED, &cs->req->flags))
913 err = -ENOENT;
914 else
915 *pagep = newpage;
916 spin_unlock(&cs->req->waitq.lock);
917
918 if (err) {
919 unlock_page(newpage);
920 put_page(newpage);
921 return err;
922 }
923
924 unlock_page(oldpage);
925 put_page(oldpage);
926 cs->len = 0;
927
928 return 0;
929
930 out_fallback_unlock:
931 unlock_page(newpage);
932 out_fallback:
933 cs->pg = buf->page;
934 cs->offset = buf->offset;
935
936 err = lock_request(cs->req);
937 if (err)
938 return err;
939
940 return 1;
941 }
942
943 static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
944 unsigned offset, unsigned count)
945 {
946 struct pipe_buffer *buf;
947 int err;
948
949 if (cs->nr_segs == cs->pipe->buffers)
950 return -EIO;
951
952 err = unlock_request(cs->req);
953 if (err)
954 return err;
955
956 fuse_copy_finish(cs);
957
958 buf = cs->pipebufs;
959 get_page(page);
960 buf->page = page;
961 buf->offset = offset;
962 buf->len = count;
963
964 cs->pipebufs++;
965 cs->nr_segs++;
966 cs->len = 0;
967
968 return 0;
969 }
970
971 /*
972 * Copy a page in the request to/from the userspace buffer. Must be
973 * done atomically
974 */
975 static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
976 unsigned offset, unsigned count, int zeroing)
977 {
978 int err;
979 struct page *page = *pagep;
980
981 if (page && zeroing && count < PAGE_SIZE)
982 clear_highpage(page);
983
984 while (count) {
985 if (cs->write && cs->pipebufs && page) {
986 return fuse_ref_page(cs, page, offset, count);
987 } else if (!cs->len) {
988 if (cs->move_pages && page &&
989 offset == 0 && count == PAGE_SIZE) {
990 err = fuse_try_move_page(cs, pagep);
991 if (err <= 0)
992 return err;
993 } else {
994 err = fuse_copy_fill(cs);
995 if (err)
996 return err;
997 }
998 }
999 if (page) {
1000 void *mapaddr = kmap_atomic(page);
1001 void *buf = mapaddr + offset;
1002 offset += fuse_copy_do(cs, &buf, &count);
1003 kunmap_atomic(mapaddr);
1004 } else
1005 offset += fuse_copy_do(cs, NULL, &count);
1006 }
1007 if (page && !cs->write)
1008 flush_dcache_page(page);
1009 return 0;
1010 }
1011
1012 /* Copy pages in the request to/from userspace buffer */
1013 static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
1014 int zeroing)
1015 {
1016 unsigned i;
1017 struct fuse_req *req = cs->req;
1018
1019 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
1020 int err;
1021 unsigned offset = req->page_descs[i].offset;
1022 unsigned count = min(nbytes, req->page_descs[i].length);
1023
1024 err = fuse_copy_page(cs, &req->pages[i], offset, count,
1025 zeroing);
1026 if (err)
1027 return err;
1028
1029 nbytes -= count;
1030 }
1031 return 0;
1032 }
1033
1034 /* Copy a single argument in the request to/from userspace buffer */
1035 static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
1036 {
1037 while (size) {
1038 if (!cs->len) {
1039 int err = fuse_copy_fill(cs);
1040 if (err)
1041 return err;
1042 }
1043 fuse_copy_do(cs, &val, &size);
1044 }
1045 return 0;
1046 }
1047
1048 /* Copy request arguments to/from userspace buffer */
1049 static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
1050 unsigned argpages, struct fuse_arg *args,
1051 int zeroing)
1052 {
1053 int err = 0;
1054 unsigned i;
1055
1056 for (i = 0; !err && i < numargs; i++) {
1057 struct fuse_arg *arg = &args[i];
1058 if (i == numargs - 1 && argpages)
1059 err = fuse_copy_pages(cs, arg->size, zeroing);
1060 else
1061 err = fuse_copy_one(cs, arg->value, arg->size);
1062 }
1063 return err;
1064 }
1065
1066 static int forget_pending(struct fuse_iqueue *fiq)
1067 {
1068 return fiq->forget_list_head.next != NULL;
1069 }
1070
1071 static int request_pending(struct fuse_iqueue *fiq)
1072 {
1073 return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) ||
1074 forget_pending(fiq);
1075 }
1076
1077 /*
1078 * Transfer an interrupt request to userspace
1079 *
1080 * Unlike other requests this is assembled on demand, without a need
1081 * to allocate a separate fuse_req structure.
1082 *
1083 * Called with fiq->waitq.lock held, releases it
1084 */
1085 static int fuse_read_interrupt(struct fuse_iqueue *fiq,
1086 struct fuse_copy_state *cs,
1087 size_t nbytes, struct fuse_req *req)
1088 __releases(fiq->waitq.lock)
1089 {
1090 struct fuse_in_header ih;
1091 struct fuse_interrupt_in arg;
1092 unsigned reqsize = sizeof(ih) + sizeof(arg);
1093 int err;
1094
1095 list_del_init(&req->intr_entry);
1096 memset(&ih, 0, sizeof(ih));
1097 memset(&arg, 0, sizeof(arg));
1098 ih.len = reqsize;
1099 ih.opcode = FUSE_INTERRUPT;
1100 ih.unique = (req->in.h.unique | FUSE_INT_REQ_BIT);
1101 arg.unique = req->in.h.unique;
1102
1103 spin_unlock(&fiq->waitq.lock);
1104 if (nbytes < reqsize)
1105 return -EINVAL;
1106
1107 err = fuse_copy_one(cs, &ih, sizeof(ih));
1108 if (!err)
1109 err = fuse_copy_one(cs, &arg, sizeof(arg));
1110 fuse_copy_finish(cs);
1111
1112 return err ? err : reqsize;
1113 }
1114
1115 static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
1116 unsigned max,
1117 unsigned *countp)
1118 {
1119 struct fuse_forget_link *head = fiq->forget_list_head.next;
1120 struct fuse_forget_link **newhead = &head;
1121 unsigned count;
1122
1123 for (count = 0; *newhead != NULL && count < max; count++)
1124 newhead = &(*newhead)->next;
1125
1126 fiq->forget_list_head.next = *newhead;
1127 *newhead = NULL;
1128 if (fiq->forget_list_head.next == NULL)
1129 fiq->forget_list_tail = &fiq->forget_list_head;
1130
1131 if (countp != NULL)
1132 *countp = count;
1133
1134 return head;
1135 }
1136
1137 static int fuse_read_single_forget(struct fuse_iqueue *fiq,
1138 struct fuse_copy_state *cs,
1139 size_t nbytes)
1140 __releases(fiq->waitq.lock)
1141 {
1142 int err;
1143 struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
1144 struct fuse_forget_in arg = {
1145 .nlookup = forget->forget_one.nlookup,
1146 };
1147 struct fuse_in_header ih = {
1148 .opcode = FUSE_FORGET,
1149 .nodeid = forget->forget_one.nodeid,
1150 .unique = fuse_get_unique(fiq),
1151 .len = sizeof(ih) + sizeof(arg),
1152 };
1153
1154 spin_unlock(&fiq->waitq.lock);
1155 kfree(forget);
1156 if (nbytes < ih.len)
1157 return -EINVAL;
1158
1159 err = fuse_copy_one(cs, &ih, sizeof(ih));
1160 if (!err)
1161 err = fuse_copy_one(cs, &arg, sizeof(arg));
1162 fuse_copy_finish(cs);
1163
1164 if (err)
1165 return err;
1166
1167 return ih.len;
1168 }
1169
1170 static int fuse_read_batch_forget(struct fuse_iqueue *fiq,
1171 struct fuse_copy_state *cs, size_t nbytes)
1172 __releases(fiq->waitq.lock)
1173 {
1174 int err;
1175 unsigned max_forgets;
1176 unsigned count;
1177 struct fuse_forget_link *head;
1178 struct fuse_batch_forget_in arg = { .count = 0 };
1179 struct fuse_in_header ih = {
1180 .opcode = FUSE_BATCH_FORGET,
1181 .unique = fuse_get_unique(fiq),
1182 .len = sizeof(ih) + sizeof(arg),
1183 };
1184
1185 if (nbytes < ih.len) {
1186 spin_unlock(&fiq->waitq.lock);
1187 return -EINVAL;
1188 }
1189
1190 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
1191 head = dequeue_forget(fiq, max_forgets, &count);
1192 spin_unlock(&fiq->waitq.lock);
1193
1194 arg.count = count;
1195 ih.len += count * sizeof(struct fuse_forget_one);
1196 err = fuse_copy_one(cs, &ih, sizeof(ih));
1197 if (!err)
1198 err = fuse_copy_one(cs, &arg, sizeof(arg));
1199
1200 while (head) {
1201 struct fuse_forget_link *forget = head;
1202
1203 if (!err) {
1204 err = fuse_copy_one(cs, &forget->forget_one,
1205 sizeof(forget->forget_one));
1206 }
1207 head = forget->next;
1208 kfree(forget);
1209 }
1210
1211 fuse_copy_finish(cs);
1212
1213 if (err)
1214 return err;
1215
1216 return ih.len;
1217 }
1218
1219 static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq,
1220 struct fuse_copy_state *cs,
1221 size_t nbytes)
1222 __releases(fiq->waitq.lock)
1223 {
1224 if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
1225 return fuse_read_single_forget(fiq, cs, nbytes);
1226 else
1227 return fuse_read_batch_forget(fiq, cs, nbytes);
1228 }
1229
1230 /*
1231 * Read a single request into the userspace filesystem's buffer. This
1232 * function waits until a request is available, then removes it from
1233 * the pending list and copies request data to userspace buffer. If
1234 * no reply is needed (FORGET) or request has been aborted or there
1235 * was an error during the copying then it's finished by calling
1236 * request_end(). Otherwise add it to the processing list, and set
1237 * the 'sent' flag.
1238 */
1239 static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file,
1240 struct fuse_copy_state *cs, size_t nbytes)
1241 {
1242 ssize_t err;
1243 struct fuse_conn *fc = fud->fc;
1244 struct fuse_iqueue *fiq = &fc->iq;
1245 struct fuse_pqueue *fpq = &fud->pq;
1246 struct fuse_req *req;
1247 struct fuse_in *in;
1248 unsigned reqsize;
1249 unsigned int hash;
1250
1251 restart:
1252 spin_lock(&fiq->waitq.lock);
1253 err = -EAGAIN;
1254 if ((file->f_flags & O_NONBLOCK) && fiq->connected &&
1255 !request_pending(fiq))
1256 goto err_unlock;
1257
1258 err = wait_event_interruptible_exclusive_locked(fiq->waitq,
1259 !fiq->connected || request_pending(fiq));
1260 if (err)
1261 goto err_unlock;
1262
1263 if (!fiq->connected) {
1264 err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV;
1265 goto err_unlock;
1266 }
1267
1268 if (!list_empty(&fiq->interrupts)) {
1269 req = list_entry(fiq->interrupts.next, struct fuse_req,
1270 intr_entry);
1271 return fuse_read_interrupt(fiq, cs, nbytes, req);
1272 }
1273
1274 if (forget_pending(fiq)) {
1275 if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
1276 return fuse_read_forget(fc, fiq, cs, nbytes);
1277
1278 if (fiq->forget_batch <= -8)
1279 fiq->forget_batch = 16;
1280 }
1281
1282 req = list_entry(fiq->pending.next, struct fuse_req, list);
1283 clear_bit(FR_PENDING, &req->flags);
1284 list_del_init(&req->list);
1285 spin_unlock(&fiq->waitq.lock);
1286
1287 in = &req->in;
1288 reqsize = in->h.len;
1289
1290 /* If request is too large, reply with an error and restart the read */
1291 if (nbytes < reqsize) {
1292 req->out.h.error = -EIO;
1293 /* SETXATTR is special, since it may contain too large data */
1294 if (in->h.opcode == FUSE_SETXATTR)
1295 req->out.h.error = -E2BIG;
1296 request_end(fc, req);
1297 goto restart;
1298 }
1299 spin_lock(&fpq->lock);
1300 list_add(&req->list, &fpq->io);
1301 spin_unlock(&fpq->lock);
1302 cs->req = req;
1303 err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1304 if (!err)
1305 err = fuse_copy_args(cs, in->numargs, in->argpages,
1306 (struct fuse_arg *) in->args, 0);
1307 fuse_copy_finish(cs);
1308 spin_lock(&fpq->lock);
1309 clear_bit(FR_LOCKED, &req->flags);
1310 if (!fpq->connected) {
1311 err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV;
1312 goto out_end;
1313 }
1314 if (err) {
1315 req->out.h.error = -EIO;
1316 goto out_end;
1317 }
1318 if (!test_bit(FR_ISREPLY, &req->flags)) {
1319 err = reqsize;
1320 goto out_end;
1321 }
1322 hash = fuse_req_hash(req->in.h.unique);
1323 list_move_tail(&req->list, &fpq->processing[hash]);
1324 __fuse_get_request(req);
1325 set_bit(FR_SENT, &req->flags);
1326 spin_unlock(&fpq->lock);
1327 /* matches barrier in request_wait_answer() */
1328 smp_mb__after_atomic();
1329 if (test_bit(FR_INTERRUPTED, &req->flags))
1330 queue_interrupt(fiq, req);
1331 fuse_put_request(fc, req);
1332
1333 return reqsize;
1334
1335 out_end:
1336 if (!test_bit(FR_PRIVATE, &req->flags))
1337 list_del_init(&req->list);
1338 spin_unlock(&fpq->lock);
1339 request_end(fc, req);
1340 return err;
1341
1342 err_unlock:
1343 spin_unlock(&fiq->waitq.lock);
1344 return err;
1345 }
1346
1347 static int fuse_dev_open(struct inode *inode, struct file *file)
1348 {
1349 /*
1350 * The fuse device's file's private_data is used to hold
1351 * the fuse_conn(ection) when it is mounted, and is used to
1352 * keep track of whether the file has been mounted already.
1353 */
1354 file->private_data = NULL;
1355 return 0;
1356 }
1357
1358 static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
1359 {
1360 struct fuse_copy_state cs;
1361 struct file *file = iocb->ki_filp;
1362 struct fuse_dev *fud = fuse_get_dev(file);
1363
1364 if (!fud)
1365 return -EPERM;
1366
1367 if (!iter_is_iovec(to))
1368 return -EINVAL;
1369
1370 fuse_copy_init(&cs, 1, to);
1371
1372 return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to));
1373 }
1374
1375 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1376 struct pipe_inode_info *pipe,
1377 size_t len, unsigned int flags)
1378 {
1379 int total, ret;
1380 int page_nr = 0;
1381 struct pipe_buffer *bufs;
1382 struct fuse_copy_state cs;
1383 struct fuse_dev *fud = fuse_get_dev(in);
1384
1385 if (!fud)
1386 return -EPERM;
1387
1388 bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
1389 GFP_KERNEL);
1390 if (!bufs)
1391 return -ENOMEM;
1392
1393 fuse_copy_init(&cs, 1, NULL);
1394 cs.pipebufs = bufs;
1395 cs.pipe = pipe;
1396 ret = fuse_dev_do_read(fud, in, &cs, len);
1397 if (ret < 0)
1398 goto out;
1399
1400 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1401 ret = -EIO;
1402 goto out;
1403 }
1404
1405 for (ret = total = 0; page_nr < cs.nr_segs; total += ret) {
1406 /*
1407 * Need to be careful about this. Having buf->ops in module
1408 * code can Oops if the buffer persists after module unload.
1409 */
1410 bufs[page_nr].ops = &nosteal_pipe_buf_ops;
1411 bufs[page_nr].flags = 0;
1412 ret = add_to_pipe(pipe, &bufs[page_nr++]);
1413 if (unlikely(ret < 0))
1414 break;
1415 }
1416 if (total)
1417 ret = total;
1418 out:
1419 for (; page_nr < cs.nr_segs; page_nr++)
1420 put_page(bufs[page_nr].page);
1421
1422 kvfree(bufs);
1423 return ret;
1424 }
1425
1426 static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1427 struct fuse_copy_state *cs)
1428 {
1429 struct fuse_notify_poll_wakeup_out outarg;
1430 int err = -EINVAL;
1431
1432 if (size != sizeof(outarg))
1433 goto err;
1434
1435 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1436 if (err)
1437 goto err;
1438
1439 fuse_copy_finish(cs);
1440 return fuse_notify_poll_wakeup(fc, &outarg);
1441
1442 err:
1443 fuse_copy_finish(cs);
1444 return err;
1445 }
1446
1447 static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1448 struct fuse_copy_state *cs)
1449 {
1450 struct fuse_notify_inval_inode_out outarg;
1451 int err = -EINVAL;
1452
1453 if (size != sizeof(outarg))
1454 goto err;
1455
1456 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1457 if (err)
1458 goto err;
1459 fuse_copy_finish(cs);
1460
1461 down_read(&fc->killsb);
1462 err = -ENOENT;
1463 if (fc->sb) {
1464 err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1465 outarg.off, outarg.len);
1466 }
1467 up_read(&fc->killsb);
1468 return err;
1469
1470 err:
1471 fuse_copy_finish(cs);
1472 return err;
1473 }
1474
1475 static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1476 struct fuse_copy_state *cs)
1477 {
1478 struct fuse_notify_inval_entry_out outarg;
1479 int err = -ENOMEM;
1480 char *buf;
1481 struct qstr name;
1482
1483 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1484 if (!buf)
1485 goto err;
1486
1487 err = -EINVAL;
1488 if (size < sizeof(outarg))
1489 goto err;
1490
1491 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1492 if (err)
1493 goto err;
1494
1495 err = -ENAMETOOLONG;
1496 if (outarg.namelen > FUSE_NAME_MAX)
1497 goto err;
1498
1499 err = -EINVAL;
1500 if (size != sizeof(outarg) + outarg.namelen + 1)
1501 goto err;
1502
1503 name.name = buf;
1504 name.len = outarg.namelen;
1505 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1506 if (err)
1507 goto err;
1508 fuse_copy_finish(cs);
1509 buf[outarg.namelen] = 0;
1510
1511 down_read(&fc->killsb);
1512 err = -ENOENT;
1513 if (fc->sb)
1514 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1515 up_read(&fc->killsb);
1516 kfree(buf);
1517 return err;
1518
1519 err:
1520 kfree(buf);
1521 fuse_copy_finish(cs);
1522 return err;
1523 }
1524
1525 static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1526 struct fuse_copy_state *cs)
1527 {
1528 struct fuse_notify_delete_out outarg;
1529 int err = -ENOMEM;
1530 char *buf;
1531 struct qstr name;
1532
1533 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1534 if (!buf)
1535 goto err;
1536
1537 err = -EINVAL;
1538 if (size < sizeof(outarg))
1539 goto err;
1540
1541 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1542 if (err)
1543 goto err;
1544
1545 err = -ENAMETOOLONG;
1546 if (outarg.namelen > FUSE_NAME_MAX)
1547 goto err;
1548
1549 err = -EINVAL;
1550 if (size != sizeof(outarg) + outarg.namelen + 1)
1551 goto err;
1552
1553 name.name = buf;
1554 name.len = outarg.namelen;
1555 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1556 if (err)
1557 goto err;
1558 fuse_copy_finish(cs);
1559 buf[outarg.namelen] = 0;
1560
1561 down_read(&fc->killsb);
1562 err = -ENOENT;
1563 if (fc->sb)
1564 err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1565 outarg.child, &name);
1566 up_read(&fc->killsb);
1567 kfree(buf);
1568 return err;
1569
1570 err:
1571 kfree(buf);
1572 fuse_copy_finish(cs);
1573 return err;
1574 }
1575
1576 static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1577 struct fuse_copy_state *cs)
1578 {
1579 struct fuse_notify_store_out outarg;
1580 struct inode *inode;
1581 struct address_space *mapping;
1582 u64 nodeid;
1583 int err;
1584 pgoff_t index;
1585 unsigned int offset;
1586 unsigned int num;
1587 loff_t file_size;
1588 loff_t end;
1589
1590 err = -EINVAL;
1591 if (size < sizeof(outarg))
1592 goto out_finish;
1593
1594 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1595 if (err)
1596 goto out_finish;
1597
1598 err = -EINVAL;
1599 if (size - sizeof(outarg) != outarg.size)
1600 goto out_finish;
1601
1602 nodeid = outarg.nodeid;
1603
1604 down_read(&fc->killsb);
1605
1606 err = -ENOENT;
1607 if (!fc->sb)
1608 goto out_up_killsb;
1609
1610 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1611 if (!inode)
1612 goto out_up_killsb;
1613
1614 mapping = inode->i_mapping;
1615 index = outarg.offset >> PAGE_SHIFT;
1616 offset = outarg.offset & ~PAGE_MASK;
1617 file_size = i_size_read(inode);
1618 end = outarg.offset + outarg.size;
1619 if (end > file_size) {
1620 file_size = end;
1621 fuse_write_update_size(inode, file_size);
1622 }
1623
1624 num = outarg.size;
1625 while (num) {
1626 struct page *page;
1627 unsigned int this_num;
1628
1629 err = -ENOMEM;
1630 page = find_or_create_page(mapping, index,
1631 mapping_gfp_mask(mapping));
1632 if (!page)
1633 goto out_iput;
1634
1635 this_num = min_t(unsigned, num, PAGE_SIZE - offset);
1636 err = fuse_copy_page(cs, &page, offset, this_num, 0);
1637 if (!err && offset == 0 &&
1638 (this_num == PAGE_SIZE || file_size == end))
1639 SetPageUptodate(page);
1640 unlock_page(page);
1641 put_page(page);
1642
1643 if (err)
1644 goto out_iput;
1645
1646 num -= this_num;
1647 offset = 0;
1648 index++;
1649 }
1650
1651 err = 0;
1652
1653 out_iput:
1654 iput(inode);
1655 out_up_killsb:
1656 up_read(&fc->killsb);
1657 out_finish:
1658 fuse_copy_finish(cs);
1659 return err;
1660 }
1661
1662 static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
1663 {
1664 release_pages(req->pages, req->num_pages);
1665 }
1666
1667 static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1668 struct fuse_notify_retrieve_out *outarg)
1669 {
1670 int err;
1671 struct address_space *mapping = inode->i_mapping;
1672 struct fuse_req *req;
1673 pgoff_t index;
1674 loff_t file_size;
1675 unsigned int num;
1676 unsigned int offset;
1677 size_t total_len = 0;
1678 unsigned int num_pages;
1679
1680 offset = outarg->offset & ~PAGE_MASK;
1681 file_size = i_size_read(inode);
1682
1683 num = outarg->size;
1684 if (outarg->offset > file_size)
1685 num = 0;
1686 else if (outarg->offset + num > file_size)
1687 num = file_size - outarg->offset;
1688
1689 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1690 num_pages = min(num_pages, fc->max_pages);
1691
1692 req = fuse_get_req(fc, num_pages);
1693 if (IS_ERR(req))
1694 return PTR_ERR(req);
1695
1696 req->in.h.opcode = FUSE_NOTIFY_REPLY;
1697 req->in.h.nodeid = outarg->nodeid;
1698 req->in.numargs = 2;
1699 req->in.argpages = 1;
1700 req->page_descs[0].offset = offset;
1701 req->end = fuse_retrieve_end;
1702
1703 index = outarg->offset >> PAGE_SHIFT;
1704
1705 while (num && req->num_pages < num_pages) {
1706 struct page *page;
1707 unsigned int this_num;
1708
1709 page = find_get_page(mapping, index);
1710 if (!page)
1711 break;
1712
1713 this_num = min_t(unsigned, num, PAGE_SIZE - offset);
1714 req->pages[req->num_pages] = page;
1715 req->page_descs[req->num_pages].length = this_num;
1716 req->num_pages++;
1717
1718 offset = 0;
1719 num -= this_num;
1720 total_len += this_num;
1721 index++;
1722 }
1723 req->misc.retrieve_in.offset = outarg->offset;
1724 req->misc.retrieve_in.size = total_len;
1725 req->in.args[0].size = sizeof(req->misc.retrieve_in);
1726 req->in.args[0].value = &req->misc.retrieve_in;
1727 req->in.args[1].size = total_len;
1728
1729 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1730 if (err)
1731 fuse_retrieve_end(fc, req);
1732
1733 return err;
1734 }
1735
1736 static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1737 struct fuse_copy_state *cs)
1738 {
1739 struct fuse_notify_retrieve_out outarg;
1740 struct inode *inode;
1741 int err;
1742
1743 err = -EINVAL;
1744 if (size != sizeof(outarg))
1745 goto copy_finish;
1746
1747 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1748 if (err)
1749 goto copy_finish;
1750
1751 fuse_copy_finish(cs);
1752
1753 down_read(&fc->killsb);
1754 err = -ENOENT;
1755 if (fc->sb) {
1756 u64 nodeid = outarg.nodeid;
1757
1758 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1759 if (inode) {
1760 err = fuse_retrieve(fc, inode, &outarg);
1761 iput(inode);
1762 }
1763 }
1764 up_read(&fc->killsb);
1765
1766 return err;
1767
1768 copy_finish:
1769 fuse_copy_finish(cs);
1770 return err;
1771 }
1772
1773 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1774 unsigned int size, struct fuse_copy_state *cs)
1775 {
1776 /* Don't try to move pages (yet) */
1777 cs->move_pages = 0;
1778
1779 switch (code) {
1780 case FUSE_NOTIFY_POLL:
1781 return fuse_notify_poll(fc, size, cs);
1782
1783 case FUSE_NOTIFY_INVAL_INODE:
1784 return fuse_notify_inval_inode(fc, size, cs);
1785
1786 case FUSE_NOTIFY_INVAL_ENTRY:
1787 return fuse_notify_inval_entry(fc, size, cs);
1788
1789 case FUSE_NOTIFY_STORE:
1790 return fuse_notify_store(fc, size, cs);
1791
1792 case FUSE_NOTIFY_RETRIEVE:
1793 return fuse_notify_retrieve(fc, size, cs);
1794
1795 case FUSE_NOTIFY_DELETE:
1796 return fuse_notify_delete(fc, size, cs);
1797
1798 default:
1799 fuse_copy_finish(cs);
1800 return -EINVAL;
1801 }
1802 }
1803
1804 /* Look up request on processing list by unique ID */
1805 static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
1806 {
1807 unsigned int hash = fuse_req_hash(unique);
1808 struct fuse_req *req;
1809
1810 list_for_each_entry(req, &fpq->processing[hash], list) {
1811 if (req->in.h.unique == unique)
1812 return req;
1813 }
1814 return NULL;
1815 }
1816
1817 static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1818 unsigned nbytes)
1819 {
1820 unsigned reqsize = sizeof(struct fuse_out_header);
1821
1822 if (out->h.error)
1823 return nbytes != reqsize ? -EINVAL : 0;
1824
1825 reqsize += len_args(out->numargs, out->args);
1826
1827 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1828 return -EINVAL;
1829 else if (reqsize > nbytes) {
1830 struct fuse_arg *lastarg = &out->args[out->numargs-1];
1831 unsigned diffsize = reqsize - nbytes;
1832 if (diffsize > lastarg->size)
1833 return -EINVAL;
1834 lastarg->size -= diffsize;
1835 }
1836 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1837 out->page_zeroing);
1838 }
1839
1840 /*
1841 * Write a single reply to a request. First the header is copied from
1842 * the write buffer. The request is then searched on the processing
1843 * list by the unique ID found in the header. If found, then remove
1844 * it from the list and copy the rest of the buffer to the request.
1845 * The request is finished by calling request_end()
1846 */
1847 static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
1848 struct fuse_copy_state *cs, size_t nbytes)
1849 {
1850 int err;
1851 struct fuse_conn *fc = fud->fc;
1852 struct fuse_pqueue *fpq = &fud->pq;
1853 struct fuse_req *req;
1854 struct fuse_out_header oh;
1855
1856 if (nbytes < sizeof(struct fuse_out_header))
1857 return -EINVAL;
1858
1859 err = fuse_copy_one(cs, &oh, sizeof(oh));
1860 if (err)
1861 goto err_finish;
1862
1863 err = -EINVAL;
1864 if (oh.len != nbytes)
1865 goto err_finish;
1866
1867 /*
1868 * Zero oh.unique indicates unsolicited notification message
1869 * and error contains notification code.
1870 */
1871 if (!oh.unique) {
1872 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
1873 return err ? err : nbytes;
1874 }
1875
1876 err = -EINVAL;
1877 if (oh.error <= -1000 || oh.error > 0)
1878 goto err_finish;
1879
1880 spin_lock(&fpq->lock);
1881 err = -ENOENT;
1882 if (!fpq->connected)
1883 goto err_unlock_pq;
1884
1885 req = request_find(fpq, oh.unique & ~FUSE_INT_REQ_BIT);
1886 if (!req)
1887 goto err_unlock_pq;
1888
1889 /* Is it an interrupt reply ID? */
1890 if (oh.unique & FUSE_INT_REQ_BIT) {
1891 __fuse_get_request(req);
1892 spin_unlock(&fpq->lock);
1893
1894 err = -EINVAL;
1895 if (nbytes != sizeof(struct fuse_out_header)) {
1896 fuse_put_request(fc, req);
1897 goto err_finish;
1898 }
1899
1900 if (oh.error == -ENOSYS)
1901 fc->no_interrupt = 1;
1902 else if (oh.error == -EAGAIN)
1903 queue_interrupt(&fc->iq, req);
1904 fuse_put_request(fc, req);
1905
1906 fuse_copy_finish(cs);
1907 return nbytes;
1908 }
1909
1910 clear_bit(FR_SENT, &req->flags);
1911 list_move(&req->list, &fpq->io);
1912 req->out.h = oh;
1913 set_bit(FR_LOCKED, &req->flags);
1914 spin_unlock(&fpq->lock);
1915 cs->req = req;
1916 if (!req->out.page_replace)
1917 cs->move_pages = 0;
1918
1919 err = copy_out_args(cs, &req->out, nbytes);
1920 fuse_copy_finish(cs);
1921
1922 spin_lock(&fpq->lock);
1923 clear_bit(FR_LOCKED, &req->flags);
1924 if (!fpq->connected)
1925 err = -ENOENT;
1926 else if (err)
1927 req->out.h.error = -EIO;
1928 if (!test_bit(FR_PRIVATE, &req->flags))
1929 list_del_init(&req->list);
1930 spin_unlock(&fpq->lock);
1931
1932 request_end(fc, req);
1933
1934 return err ? err : nbytes;
1935
1936 err_unlock_pq:
1937 spin_unlock(&fpq->lock);
1938 err_finish:
1939 fuse_copy_finish(cs);
1940 return err;
1941 }
1942
1943 static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
1944 {
1945 struct fuse_copy_state cs;
1946 struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp);
1947
1948 if (!fud)
1949 return -EPERM;
1950
1951 if (!iter_is_iovec(from))
1952 return -EINVAL;
1953
1954 fuse_copy_init(&cs, 0, from);
1955
1956 return fuse_dev_do_write(fud, &cs, iov_iter_count(from));
1957 }
1958
1959 static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1960 struct file *out, loff_t *ppos,
1961 size_t len, unsigned int flags)
1962 {
1963 unsigned nbuf;
1964 unsigned idx;
1965 struct pipe_buffer *bufs;
1966 struct fuse_copy_state cs;
1967 struct fuse_dev *fud;
1968 size_t rem;
1969 ssize_t ret;
1970
1971 fud = fuse_get_dev(out);
1972 if (!fud)
1973 return -EPERM;
1974
1975 pipe_lock(pipe);
1976
1977 bufs = kvmalloc_array(pipe->nrbufs, sizeof(struct pipe_buffer),
1978 GFP_KERNEL);
1979 if (!bufs) {
1980 pipe_unlock(pipe);
1981 return -ENOMEM;
1982 }
1983
1984 nbuf = 0;
1985 rem = 0;
1986 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
1987 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
1988
1989 ret = -EINVAL;
1990 if (rem < len) {
1991 pipe_unlock(pipe);
1992 goto out;
1993 }
1994
1995 rem = len;
1996 while (rem) {
1997 struct pipe_buffer *ibuf;
1998 struct pipe_buffer *obuf;
1999
2000 BUG_ON(nbuf >= pipe->buffers);
2001 BUG_ON(!pipe->nrbufs);
2002 ibuf = &pipe->bufs[pipe->curbuf];
2003 obuf = &bufs[nbuf];
2004
2005 if (rem >= ibuf->len) {
2006 *obuf = *ibuf;
2007 ibuf->ops = NULL;
2008 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
2009 pipe->nrbufs--;
2010 } else {
2011 pipe_buf_get(pipe, ibuf);
2012 *obuf = *ibuf;
2013 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
2014 obuf->len = rem;
2015 ibuf->offset += obuf->len;
2016 ibuf->len -= obuf->len;
2017 }
2018 nbuf++;
2019 rem -= obuf->len;
2020 }
2021 pipe_unlock(pipe);
2022
2023 fuse_copy_init(&cs, 0, NULL);
2024 cs.pipebufs = bufs;
2025 cs.nr_segs = nbuf;
2026 cs.pipe = pipe;
2027
2028 if (flags & SPLICE_F_MOVE)
2029 cs.move_pages = 1;
2030
2031 ret = fuse_dev_do_write(fud, &cs, len);
2032
2033 for (idx = 0; idx < nbuf; idx++)
2034 pipe_buf_release(pipe, &bufs[idx]);
2035
2036 out:
2037 kvfree(bufs);
2038 return ret;
2039 }
2040
2041 static __poll_t fuse_dev_poll(struct file *file, poll_table *wait)
2042 {
2043 __poll_t mask = EPOLLOUT | EPOLLWRNORM;
2044 struct fuse_iqueue *fiq;
2045 struct fuse_dev *fud = fuse_get_dev(file);
2046
2047 if (!fud)
2048 return EPOLLERR;
2049
2050 fiq = &fud->fc->iq;
2051 poll_wait(file, &fiq->waitq, wait);
2052
2053 spin_lock(&fiq->waitq.lock);
2054 if (!fiq->connected)
2055 mask = EPOLLERR;
2056 else if (request_pending(fiq))
2057 mask |= EPOLLIN | EPOLLRDNORM;
2058 spin_unlock(&fiq->waitq.lock);
2059
2060 return mask;
2061 }
2062
2063 /*
2064 * Abort all requests on the given list (pending or processing)
2065 *
2066 * This function releases and reacquires fc->lock
2067 */
2068 static void end_requests(struct fuse_conn *fc, struct list_head *head)
2069 {
2070 while (!list_empty(head)) {
2071 struct fuse_req *req;
2072 req = list_entry(head->next, struct fuse_req, list);
2073 req->out.h.error = -ECONNABORTED;
2074 clear_bit(FR_SENT, &req->flags);
2075 list_del_init(&req->list);
2076 request_end(fc, req);
2077 }
2078 }
2079
2080 static void end_polls(struct fuse_conn *fc)
2081 {
2082 struct rb_node *p;
2083
2084 p = rb_first(&fc->polled_files);
2085
2086 while (p) {
2087 struct fuse_file *ff;
2088 ff = rb_entry(p, struct fuse_file, polled_node);
2089 wake_up_interruptible_all(&ff->poll_wait);
2090
2091 p = rb_next(p);
2092 }
2093 }
2094
2095 /*
2096 * Abort all requests.
2097 *
2098 * Emergency exit in case of a malicious or accidental deadlock, or just a hung
2099 * filesystem.
2100 *
2101 * The same effect is usually achievable through killing the filesystem daemon
2102 * and all users of the filesystem. The exception is the combination of an
2103 * asynchronous request and the tricky deadlock (see
2104 * Documentation/filesystems/fuse.txt).
2105 *
2106 * Aborting requests under I/O goes as follows: 1: Separate out unlocked
2107 * requests, they should be finished off immediately. Locked requests will be
2108 * finished after unlock; see unlock_request(). 2: Finish off the unlocked
2109 * requests. It is possible that some request will finish before we can. This
2110 * is OK, the request will in that case be removed from the list before we touch
2111 * it.
2112 */
2113 void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
2114 {
2115 struct fuse_iqueue *fiq = &fc->iq;
2116
2117 spin_lock(&fc->lock);
2118 if (fc->connected) {
2119 struct fuse_dev *fud;
2120 struct fuse_req *req, *next;
2121 LIST_HEAD(to_end);
2122 unsigned int i;
2123
2124 /* Background queuing checks fc->connected under bg_lock */
2125 spin_lock(&fc->bg_lock);
2126 fc->connected = 0;
2127 spin_unlock(&fc->bg_lock);
2128
2129 fc->aborted = is_abort;
2130 fuse_set_initialized(fc);
2131 list_for_each_entry(fud, &fc->devices, entry) {
2132 struct fuse_pqueue *fpq = &fud->pq;
2133
2134 spin_lock(&fpq->lock);
2135 fpq->connected = 0;
2136 list_for_each_entry_safe(req, next, &fpq->io, list) {
2137 req->out.h.error = -ECONNABORTED;
2138 spin_lock(&req->waitq.lock);
2139 set_bit(FR_ABORTED, &req->flags);
2140 if (!test_bit(FR_LOCKED, &req->flags)) {
2141 set_bit(FR_PRIVATE, &req->flags);
2142 __fuse_get_request(req);
2143 list_move(&req->list, &to_end);
2144 }
2145 spin_unlock(&req->waitq.lock);
2146 }
2147 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
2148 list_splice_tail_init(&fpq->processing[i],
2149 &to_end);
2150 spin_unlock(&fpq->lock);
2151 }
2152 spin_lock(&fc->bg_lock);
2153 fc->blocked = 0;
2154 fc->max_background = UINT_MAX;
2155 flush_bg_queue(fc);
2156 spin_unlock(&fc->bg_lock);
2157
2158 spin_lock(&fiq->waitq.lock);
2159 fiq->connected = 0;
2160 list_for_each_entry(req, &fiq->pending, list)
2161 clear_bit(FR_PENDING, &req->flags);
2162 list_splice_tail_init(&fiq->pending, &to_end);
2163 while (forget_pending(fiq))
2164 kfree(dequeue_forget(fiq, 1, NULL));
2165 wake_up_all_locked(&fiq->waitq);
2166 spin_unlock(&fiq->waitq.lock);
2167 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
2168 end_polls(fc);
2169 wake_up_all(&fc->blocked_waitq);
2170 spin_unlock(&fc->lock);
2171
2172 end_requests(fc, &to_end);
2173 } else {
2174 spin_unlock(&fc->lock);
2175 }
2176 }
2177 EXPORT_SYMBOL_GPL(fuse_abort_conn);
2178
2179 void fuse_wait_aborted(struct fuse_conn *fc)
2180 {
2181 wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0);
2182 }
2183
2184 int fuse_dev_release(struct inode *inode, struct file *file)
2185 {
2186 struct fuse_dev *fud = fuse_get_dev(file);
2187
2188 if (fud) {
2189 struct fuse_conn *fc = fud->fc;
2190 struct fuse_pqueue *fpq = &fud->pq;
2191 LIST_HEAD(to_end);
2192 unsigned int i;
2193
2194 spin_lock(&fpq->lock);
2195 WARN_ON(!list_empty(&fpq->io));
2196 for (i = 0; i < FUSE_PQ_HASH_SIZE; i++)
2197 list_splice_init(&fpq->processing[i], &to_end);
2198 spin_unlock(&fpq->lock);
2199
2200 end_requests(fc, &to_end);
2201
2202 /* Are we the last open device? */
2203 if (atomic_dec_and_test(&fc->dev_count)) {
2204 WARN_ON(fc->iq.fasync != NULL);
2205 fuse_abort_conn(fc, false);
2206 }
2207 fuse_dev_free(fud);
2208 }
2209 return 0;
2210 }
2211 EXPORT_SYMBOL_GPL(fuse_dev_release);
2212
2213 static int fuse_dev_fasync(int fd, struct file *file, int on)
2214 {
2215 struct fuse_dev *fud = fuse_get_dev(file);
2216
2217 if (!fud)
2218 return -EPERM;
2219
2220 /* No locking - fasync_helper does its own locking */
2221 return fasync_helper(fd, file, on, &fud->fc->iq.fasync);
2222 }
2223
2224 static int fuse_device_clone(struct fuse_conn *fc, struct file *new)
2225 {
2226 struct fuse_dev *fud;
2227
2228 if (new->private_data)
2229 return -EINVAL;
2230
2231 fud = fuse_dev_alloc(fc);
2232 if (!fud)
2233 return -ENOMEM;
2234
2235 new->private_data = fud;
2236 atomic_inc(&fc->dev_count);
2237
2238 return 0;
2239 }
2240
2241 static long fuse_dev_ioctl(struct file *file, unsigned int cmd,
2242 unsigned long arg)
2243 {
2244 int err = -ENOTTY;
2245
2246 if (cmd == FUSE_DEV_IOC_CLONE) {
2247 int oldfd;
2248
2249 err = -EFAULT;
2250 if (!get_user(oldfd, (__u32 __user *) arg)) {
2251 struct file *old = fget(oldfd);
2252
2253 err = -EINVAL;
2254 if (old) {
2255 struct fuse_dev *fud = NULL;
2256
2257 /*
2258 * Check against file->f_op because CUSE
2259 * uses the same ioctl handler.
2260 */
2261 if (old->f_op == file->f_op &&
2262 old->f_cred->user_ns == file->f_cred->user_ns)
2263 fud = fuse_get_dev(old);
2264
2265 if (fud) {
2266 mutex_lock(&fuse_mutex);
2267 err = fuse_device_clone(fud->fc, file);
2268 mutex_unlock(&fuse_mutex);
2269 }
2270 fput(old);
2271 }
2272 }
2273 }
2274 return err;
2275 }
2276
2277 const struct file_operations fuse_dev_operations = {
2278 .owner = THIS_MODULE,
2279 .open = fuse_dev_open,
2280 .llseek = no_llseek,
2281 .read_iter = fuse_dev_read,
2282 .splice_read = fuse_dev_splice_read,
2283 .write_iter = fuse_dev_write,
2284 .splice_write = fuse_dev_splice_write,
2285 .poll = fuse_dev_poll,
2286 .release = fuse_dev_release,
2287 .fasync = fuse_dev_fasync,
2288 .unlocked_ioctl = fuse_dev_ioctl,
2289 .compat_ioctl = fuse_dev_ioctl,
2290 };
2291 EXPORT_SYMBOL_GPL(fuse_dev_operations);
2292
2293 static struct miscdevice fuse_miscdevice = {
2294 .minor = FUSE_MINOR,
2295 .name = "fuse",
2296 .fops = &fuse_dev_operations,
2297 };
2298
2299 int __init fuse_dev_init(void)
2300 {
2301 int err = -ENOMEM;
2302 fuse_req_cachep = kmem_cache_create("fuse_request",
2303 sizeof(struct fuse_req),
2304 0, 0, NULL);
2305 if (!fuse_req_cachep)
2306 goto out;
2307
2308 err = misc_register(&fuse_miscdevice);
2309 if (err)
2310 goto out_cache_clean;
2311
2312 return 0;
2313
2314 out_cache_clean:
2315 kmem_cache_destroy(fuse_req_cachep);
2316 out:
2317 return err;
2318 }
2319
2320 void fuse_dev_cleanup(void)
2321 {
2322 misc_deregister(&fuse_miscdevice);
2323 kmem_cache_destroy(fuse_req_cachep);
2324 }
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