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334f485d
MS
1/*
2 FUSE: Filesystem in Userspace
1729a16c 3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
334f485d
MS
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>
dd3bb14f 19#include <linux/pipe_fs_i.h>
ce534fb0
MS
20#include <linux/swap.h>
21#include <linux/splice.h>
334f485d
MS
22
23MODULE_ALIAS_MISCDEV(FUSE_MINOR);
578454ff 24MODULE_ALIAS("devname:fuse");
334f485d 25
e18b890b 26static struct kmem_cache *fuse_req_cachep;
334f485d 27
cc080e9e 28static struct fuse_dev *fuse_get_dev(struct file *file)
334f485d 29{
0720b315
MS
30 /*
31 * Lockless access is OK, because file->private data is set
32 * once during mount and is valid until the file is released.
33 */
cc080e9e 34 return ACCESS_ONCE(file->private_data);
334f485d
MS
35}
36
4250c066 37static void fuse_request_init(struct fuse_req *req, struct page **pages,
b2430d75 38 struct fuse_page_desc *page_descs,
4250c066 39 unsigned npages)
334f485d
MS
40{
41 memset(req, 0, sizeof(*req));
4250c066 42 memset(pages, 0, sizeof(*pages) * npages);
b2430d75 43 memset(page_descs, 0, sizeof(*page_descs) * npages);
334f485d 44 INIT_LIST_HEAD(&req->list);
a4d27e75 45 INIT_LIST_HEAD(&req->intr_entry);
334f485d
MS
46 init_waitqueue_head(&req->waitq);
47 atomic_set(&req->count, 1);
4250c066 48 req->pages = pages;
b2430d75 49 req->page_descs = page_descs;
4250c066 50 req->max_pages = npages;
33e14b4d 51 __set_bit(FR_PENDING, &req->flags);
334f485d
MS
52}
53
4250c066 54static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
334f485d 55{
4250c066
MP
56 struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags);
57 if (req) {
58 struct page **pages;
b2430d75 59 struct fuse_page_desc *page_descs;
4250c066 60
b2430d75 61 if (npages <= FUSE_REQ_INLINE_PAGES) {
4250c066 62 pages = req->inline_pages;
b2430d75
MP
63 page_descs = req->inline_page_descs;
64 } else {
4250c066 65 pages = kmalloc(sizeof(struct page *) * npages, flags);
b2430d75
MP
66 page_descs = kmalloc(sizeof(struct fuse_page_desc) *
67 npages, flags);
68 }
4250c066 69
b2430d75
MP
70 if (!pages || !page_descs) {
71 kfree(pages);
72 kfree(page_descs);
4250c066
MP
73 kmem_cache_free(fuse_req_cachep, req);
74 return NULL;
75 }
76
b2430d75 77 fuse_request_init(req, pages, page_descs, npages);
4250c066 78 }
334f485d
MS
79 return req;
80}
4250c066
MP
81
82struct fuse_req *fuse_request_alloc(unsigned npages)
83{
84 return __fuse_request_alloc(npages, GFP_KERNEL);
85}
08cbf542 86EXPORT_SYMBOL_GPL(fuse_request_alloc);
334f485d 87
4250c066 88struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
3be5a52b 89{
4250c066 90 return __fuse_request_alloc(npages, GFP_NOFS);
3be5a52b
MS
91}
92
334f485d
MS
93void fuse_request_free(struct fuse_req *req)
94{
b2430d75 95 if (req->pages != req->inline_pages) {
4250c066 96 kfree(req->pages);
b2430d75
MP
97 kfree(req->page_descs);
98 }
334f485d
MS
99 kmem_cache_free(fuse_req_cachep, req);
100}
101
36cf66ed 102void __fuse_get_request(struct fuse_req *req)
334f485d
MS
103{
104 atomic_inc(&req->count);
105}
106
107/* Must be called with > 1 refcount */
108static void __fuse_put_request(struct fuse_req *req)
109{
110 BUG_ON(atomic_read(&req->count) < 2);
111 atomic_dec(&req->count);
112}
113
33649c91
MS
114static void fuse_req_init_context(struct fuse_req *req)
115{
499dcf20
EB
116 req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid());
117 req->in.h.gid = from_kgid_munged(&init_user_ns, current_fsgid());
33649c91
MS
118 req->in.h.pid = current->pid;
119}
120
9759bd51
MS
121void fuse_set_initialized(struct fuse_conn *fc)
122{
123 /* Make sure stores before this are seen on another CPU */
124 smp_wmb();
125 fc->initialized = 1;
126}
127
0aada884
MP
128static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
129{
130 return !fc->initialized || (for_background && fc->blocked);
131}
132
8b41e671
MP
133static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
134 bool for_background)
334f485d 135{
08a53cdc 136 struct fuse_req *req;
08a53cdc 137 int err;
9bc5ddda 138 atomic_inc(&fc->num_waiting);
0aada884
MP
139
140 if (fuse_block_alloc(fc, for_background)) {
0aada884 141 err = -EINTR;
7d3a07fc
AV
142 if (wait_event_killable_exclusive(fc->blocked_waitq,
143 !fuse_block_alloc(fc, for_background)))
0aada884
MP
144 goto out;
145 }
9759bd51
MS
146 /* Matches smp_wmb() in fuse_set_initialized() */
147 smp_rmb();
08a53cdc 148
51eb01e7
MS
149 err = -ENOTCONN;
150 if (!fc->connected)
151 goto out;
152
de155226
MS
153 err = -ECONNREFUSED;
154 if (fc->conn_error)
155 goto out;
156
b111c8c0 157 req = fuse_request_alloc(npages);
9bc5ddda 158 err = -ENOMEM;
722d2bea
MP
159 if (!req) {
160 if (for_background)
161 wake_up(&fc->blocked_waitq);
9bc5ddda 162 goto out;
722d2bea 163 }
334f485d 164
33649c91 165 fuse_req_init_context(req);
825d6d33
MS
166 __set_bit(FR_WAITING, &req->flags);
167 if (for_background)
168 __set_bit(FR_BACKGROUND, &req->flags);
169
334f485d 170 return req;
9bc5ddda
MS
171
172 out:
173 atomic_dec(&fc->num_waiting);
174 return ERR_PTR(err);
334f485d 175}
8b41e671
MP
176
177struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
178{
179 return __fuse_get_req(fc, npages, false);
180}
08cbf542 181EXPORT_SYMBOL_GPL(fuse_get_req);
334f485d 182
8b41e671
MP
183struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
184 unsigned npages)
185{
186 return __fuse_get_req(fc, npages, true);
187}
188EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
189
33649c91
MS
190/*
191 * Return request in fuse_file->reserved_req. However that may
192 * currently be in use. If that is the case, wait for it to become
193 * available.
194 */
195static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
196 struct file *file)
197{
198 struct fuse_req *req = NULL;
199 struct fuse_file *ff = file->private_data;
200
201 do {
de5e3dec 202 wait_event(fc->reserved_req_waitq, ff->reserved_req);
33649c91
MS
203 spin_lock(&fc->lock);
204 if (ff->reserved_req) {
205 req = ff->reserved_req;
206 ff->reserved_req = NULL;
cb0942b8 207 req->stolen_file = get_file(file);
33649c91
MS
208 }
209 spin_unlock(&fc->lock);
210 } while (!req);
211
212 return req;
213}
214
215/*
216 * Put stolen request back into fuse_file->reserved_req
217 */
218static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
219{
220 struct file *file = req->stolen_file;
221 struct fuse_file *ff = file->private_data;
222
223 spin_lock(&fc->lock);
b2430d75 224 fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
33649c91
MS
225 BUG_ON(ff->reserved_req);
226 ff->reserved_req = req;
de5e3dec 227 wake_up_all(&fc->reserved_req_waitq);
33649c91
MS
228 spin_unlock(&fc->lock);
229 fput(file);
230}
231
232/*
233 * Gets a requests for a file operation, always succeeds
234 *
235 * This is used for sending the FLUSH request, which must get to
236 * userspace, due to POSIX locks which may need to be unlocked.
237 *
238 * If allocation fails due to OOM, use the reserved request in
239 * fuse_file.
240 *
241 * This is very unlikely to deadlock accidentally, since the
242 * filesystem should not have it's own file open. If deadlock is
243 * intentional, it can still be broken by "aborting" the filesystem.
244 */
b111c8c0
MP
245struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
246 struct file *file)
33649c91
MS
247{
248 struct fuse_req *req;
249
250 atomic_inc(&fc->num_waiting);
0aada884 251 wait_event(fc->blocked_waitq, fc->initialized);
9759bd51
MS
252 /* Matches smp_wmb() in fuse_set_initialized() */
253 smp_rmb();
b111c8c0 254 req = fuse_request_alloc(0);
33649c91
MS
255 if (!req)
256 req = get_reserved_req(fc, file);
257
258 fuse_req_init_context(req);
825d6d33
MS
259 __set_bit(FR_WAITING, &req->flags);
260 __clear_bit(FR_BACKGROUND, &req->flags);
33649c91
MS
261 return req;
262}
263
334f485d 264void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
7128ec2a
MS
265{
266 if (atomic_dec_and_test(&req->count)) {
825d6d33 267 if (test_bit(FR_BACKGROUND, &req->flags)) {
722d2bea
MP
268 /*
269 * We get here in the unlikely case that a background
270 * request was allocated but not sent
271 */
272 spin_lock(&fc->lock);
273 if (!fc->blocked)
274 wake_up(&fc->blocked_waitq);
275 spin_unlock(&fc->lock);
276 }
277
825d6d33
MS
278 if (test_bit(FR_WAITING, &req->flags)) {
279 __clear_bit(FR_WAITING, &req->flags);
9bc5ddda 280 atomic_dec(&fc->num_waiting);
73e0e738 281 }
33649c91
MS
282
283 if (req->stolen_file)
284 put_reserved_req(fc, req);
285 else
286 fuse_request_free(req);
7128ec2a
MS
287 }
288}
08cbf542 289EXPORT_SYMBOL_GPL(fuse_put_request);
7128ec2a 290
d12def1b
MS
291static unsigned len_args(unsigned numargs, struct fuse_arg *args)
292{
293 unsigned nbytes = 0;
294 unsigned i;
295
296 for (i = 0; i < numargs; i++)
297 nbytes += args[i].size;
298
299 return nbytes;
300}
301
f88996a9 302static u64 fuse_get_unique(struct fuse_iqueue *fiq)
d12def1b 303{
f88996a9 304 return ++fiq->reqctr;
d12def1b
MS
305}
306
f88996a9 307static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
d12def1b 308{
d12def1b
MS
309 req->in.h.len = sizeof(struct fuse_in_header) +
310 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
f88996a9 311 list_add_tail(&req->list, &fiq->pending);
4ce60812 312 wake_up_locked(&fiq->waitq);
f88996a9 313 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
d12def1b
MS
314}
315
07e77dca
MS
316void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
317 u64 nodeid, u64 nlookup)
318{
f88996a9
MS
319 struct fuse_iqueue *fiq = &fc->iq;
320
02c048b9
MS
321 forget->forget_one.nodeid = nodeid;
322 forget->forget_one.nlookup = nlookup;
07e77dca 323
4ce60812 324 spin_lock(&fiq->waitq.lock);
e16714d8 325 if (fiq->connected) {
f88996a9
MS
326 fiq->forget_list_tail->next = forget;
327 fiq->forget_list_tail = forget;
4ce60812 328 wake_up_locked(&fiq->waitq);
f88996a9 329 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
5dfcc87f
MS
330 } else {
331 kfree(forget);
332 }
4ce60812 333 spin_unlock(&fiq->waitq.lock);
07e77dca
MS
334}
335
d12def1b
MS
336static void flush_bg_queue(struct fuse_conn *fc)
337{
7a6d3c8b 338 while (fc->active_background < fc->max_background &&
d12def1b
MS
339 !list_empty(&fc->bg_queue)) {
340 struct fuse_req *req;
f88996a9 341 struct fuse_iqueue *fiq = &fc->iq;
d12def1b
MS
342
343 req = list_entry(fc->bg_queue.next, struct fuse_req, list);
344 list_del(&req->list);
345 fc->active_background++;
4ce60812 346 spin_lock(&fiq->waitq.lock);
f88996a9
MS
347 req->in.h.unique = fuse_get_unique(fiq);
348 queue_request(fiq, req);
4ce60812 349 spin_unlock(&fiq->waitq.lock);
d12def1b
MS
350 }
351}
352
334f485d
MS
353/*
354 * This function is called when a request is finished. Either a reply
f9a2842e 355 * has arrived or it was aborted (and not yet sent) or some error
f43b155a 356 * occurred during communication with userspace, or the device file
51eb01e7
MS
357 * was closed. The requester thread is woken up (if still waiting),
358 * the 'end' callback is called if given, else the reference to the
359 * request is released
334f485d
MS
360 */
361static void request_end(struct fuse_conn *fc, struct fuse_req *req)
362{
4ce60812 363 struct fuse_iqueue *fiq = &fc->iq;
365ae710 364
efe2800f 365 if (test_and_set_bit(FR_FINISHED, &req->flags))
365ae710 366 return;
365ae710 367
4ce60812 368 spin_lock(&fiq->waitq.lock);
0d8e84b0 369 list_del_init(&req->intr_entry);
4ce60812 370 spin_unlock(&fiq->waitq.lock);
33e14b4d
MS
371 WARN_ON(test_bit(FR_PENDING, &req->flags));
372 WARN_ON(test_bit(FR_SENT, &req->flags));
825d6d33 373 if (test_bit(FR_BACKGROUND, &req->flags)) {
efe2800f 374 spin_lock(&fc->lock);
825d6d33 375 clear_bit(FR_BACKGROUND, &req->flags);
722d2bea 376 if (fc->num_background == fc->max_background)
51eb01e7 377 fc->blocked = 0;
722d2bea
MP
378
379 /* Wake up next waiter, if any */
3c18ef81 380 if (!fc->blocked && waitqueue_active(&fc->blocked_waitq))
722d2bea
MP
381 wake_up(&fc->blocked_waitq);
382
7a6d3c8b 383 if (fc->num_background == fc->congestion_threshold &&
a325f9b9 384 fc->connected && fc->bdi_initialized) {
8aa7e847
JA
385 clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
386 clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
f92b99b9 387 }
51eb01e7 388 fc->num_background--;
d12def1b
MS
389 fc->active_background--;
390 flush_bg_queue(fc);
efe2800f 391 spin_unlock(&fc->lock);
334f485d 392 }
51eb01e7 393 wake_up(&req->waitq);
1e6881c3
MS
394 if (req->end)
395 req->end(fc, req);
e9bb09dd 396 fuse_put_request(fc, req);
334f485d
MS
397}
398
f88996a9 399static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
a4d27e75 400{
4ce60812 401 spin_lock(&fiq->waitq.lock);
8f7bb368
MS
402 if (list_empty(&req->intr_entry)) {
403 list_add_tail(&req->intr_entry, &fiq->interrupts);
404 wake_up_locked(&fiq->waitq);
405 }
4ce60812 406 spin_unlock(&fiq->waitq.lock);
f88996a9 407 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
a4d27e75
MS
408}
409
7c352bdf 410static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
334f485d 411{
4ce60812 412 struct fuse_iqueue *fiq = &fc->iq;
c4775267
MS
413 int err;
414
a4d27e75
MS
415 if (!fc->no_interrupt) {
416 /* Any signal may interrupt this */
c4775267 417 err = wait_event_interruptible(req->waitq,
33e14b4d 418 test_bit(FR_FINISHED, &req->flags));
c4775267 419 if (!err)
a4d27e75
MS
420 return;
421
825d6d33 422 set_bit(FR_INTERRUPTED, &req->flags);
8f7bb368
MS
423 /* matches barrier in fuse_dev_do_read() */
424 smp_mb__after_atomic();
33e14b4d 425 if (test_bit(FR_SENT, &req->flags))
4ce60812 426 queue_interrupt(fiq, req);
a4d27e75
MS
427 }
428
825d6d33 429 if (!test_bit(FR_FORCE, &req->flags)) {
a4d27e75 430 /* Only fatal signals may interrupt this */
7d3a07fc 431 err = wait_event_killable(req->waitq,
33e14b4d 432 test_bit(FR_FINISHED, &req->flags));
c4775267 433 if (!err)
a131de0a
MS
434 return;
435
4ce60812 436 spin_lock(&fiq->waitq.lock);
a131de0a 437 /* Request is not yet in userspace, bail out */
33e14b4d 438 if (test_bit(FR_PENDING, &req->flags)) {
a131de0a 439 list_del(&req->list);
4ce60812 440 spin_unlock(&fiq->waitq.lock);
a131de0a
MS
441 __fuse_put_request(req);
442 req->out.h.error = -EINTR;
443 return;
444 }
4ce60812 445 spin_unlock(&fiq->waitq.lock);
51eb01e7 446 }
334f485d 447
a131de0a
MS
448 /*
449 * Either request is already in userspace, or it was forced.
450 * Wait it out.
451 */
33e14b4d 452 wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
334f485d
MS
453}
454
6a4e922c 455static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
334f485d 456{
e16714d8
MS
457 struct fuse_iqueue *fiq = &fc->iq;
458
825d6d33 459 BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
4ce60812 460 spin_lock(&fiq->waitq.lock);
e16714d8 461 if (!fiq->connected) {
4ce60812 462 spin_unlock(&fiq->waitq.lock);
334f485d 463 req->out.h.error = -ENOTCONN;
c4775267 464 } else {
f88996a9
MS
465 req->in.h.unique = fuse_get_unique(fiq);
466 queue_request(fiq, req);
334f485d
MS
467 /* acquire extra reference, since request is still needed
468 after request_end() */
469 __fuse_get_request(req);
4ce60812 470 spin_unlock(&fiq->waitq.lock);
334f485d 471
7c352bdf 472 request_wait_answer(fc, req);
c4775267
MS
473 /* Pairs with smp_wmb() in request_end() */
474 smp_rmb();
334f485d 475 }
334f485d 476}
6a4e922c
EW
477
478void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
479{
825d6d33
MS
480 __set_bit(FR_ISREPLY, &req->flags);
481 if (!test_bit(FR_WAITING, &req->flags)) {
482 __set_bit(FR_WAITING, &req->flags);
5437f241
MS
483 atomic_inc(&fc->num_waiting);
484 }
6a4e922c
EW
485 __fuse_request_send(fc, req);
486}
08cbf542 487EXPORT_SYMBOL_GPL(fuse_request_send);
334f485d 488
21f62174
MS
489static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
490{
491 if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS)
492 args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE;
493
494 if (fc->minor < 9) {
495 switch (args->in.h.opcode) {
496 case FUSE_LOOKUP:
497 case FUSE_CREATE:
498 case FUSE_MKNOD:
499 case FUSE_MKDIR:
500 case FUSE_SYMLINK:
501 case FUSE_LINK:
502 args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
503 break;
504 case FUSE_GETATTR:
505 case FUSE_SETATTR:
506 args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
507 break;
508 }
509 }
510 if (fc->minor < 12) {
511 switch (args->in.h.opcode) {
512 case FUSE_CREATE:
513 args->in.args[0].size = sizeof(struct fuse_open_in);
514 break;
515 case FUSE_MKNOD:
516 args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
517 break;
518 }
519 }
520}
521
7078187a
MS
522ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
523{
524 struct fuse_req *req;
525 ssize_t ret;
526
527 req = fuse_get_req(fc, 0);
528 if (IS_ERR(req))
529 return PTR_ERR(req);
530
21f62174
MS
531 /* Needs to be done after fuse_get_req() so that fc->minor is valid */
532 fuse_adjust_compat(fc, args);
533
7078187a
MS
534 req->in.h.opcode = args->in.h.opcode;
535 req->in.h.nodeid = args->in.h.nodeid;
536 req->in.numargs = args->in.numargs;
537 memcpy(req->in.args, args->in.args,
538 args->in.numargs * sizeof(struct fuse_in_arg));
539 req->out.argvar = args->out.argvar;
540 req->out.numargs = args->out.numargs;
541 memcpy(req->out.args, args->out.args,
542 args->out.numargs * sizeof(struct fuse_arg));
543 fuse_request_send(fc, req);
544 ret = req->out.h.error;
545 if (!ret && args->out.argvar) {
546 BUG_ON(args->out.numargs != 1);
547 ret = req->out.args[0].size;
548 }
549 fuse_put_request(fc, req);
550
551 return ret;
552}
553
f0139aa8
MS
554/*
555 * Called under fc->lock
556 *
557 * fc->connected must have been checked previously
558 */
559void fuse_request_send_background_locked(struct fuse_conn *fc,
560 struct fuse_req *req)
d12def1b 561{
825d6d33
MS
562 BUG_ON(!test_bit(FR_BACKGROUND, &req->flags));
563 if (!test_bit(FR_WAITING, &req->flags)) {
564 __set_bit(FR_WAITING, &req->flags);
5437f241
MS
565 atomic_inc(&fc->num_waiting);
566 }
825d6d33 567 __set_bit(FR_ISREPLY, &req->flags);
d12def1b 568 fc->num_background++;
7a6d3c8b 569 if (fc->num_background == fc->max_background)
d12def1b 570 fc->blocked = 1;
7a6d3c8b 571 if (fc->num_background == fc->congestion_threshold &&
a325f9b9 572 fc->bdi_initialized) {
8aa7e847
JA
573 set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
574 set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
d12def1b
MS
575 }
576 list_add_tail(&req->list, &fc->bg_queue);
577 flush_bg_queue(fc);
578}
579
f0139aa8 580void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
334f485d 581{
42dc6211 582 BUG_ON(!req->end);
d7133114 583 spin_lock(&fc->lock);
1e9a4ed9 584 if (fc->connected) {
f0139aa8 585 fuse_request_send_background_locked(fc, req);
d7133114 586 spin_unlock(&fc->lock);
334f485d 587 } else {
42dc6211 588 spin_unlock(&fc->lock);
334f485d 589 req->out.h.error = -ENOTCONN;
42dc6211
MS
590 req->end(fc, req);
591 fuse_put_request(fc, req);
334f485d
MS
592 }
593}
08cbf542 594EXPORT_SYMBOL_GPL(fuse_request_send_background);
334f485d 595
2d45ba38
MS
596static int fuse_request_send_notify_reply(struct fuse_conn *fc,
597 struct fuse_req *req, u64 unique)
598{
599 int err = -ENODEV;
f88996a9 600 struct fuse_iqueue *fiq = &fc->iq;
2d45ba38 601
825d6d33 602 __clear_bit(FR_ISREPLY, &req->flags);
2d45ba38 603 req->in.h.unique = unique;
4ce60812 604 spin_lock(&fiq->waitq.lock);
e16714d8 605 if (fiq->connected) {
f88996a9 606 queue_request(fiq, req);
2d45ba38
MS
607 err = 0;
608 }
4ce60812 609 spin_unlock(&fiq->waitq.lock);
2d45ba38
MS
610
611 return err;
612}
613
0b05b183
AA
614void fuse_force_forget(struct file *file, u64 nodeid)
615{
6131ffaa 616 struct inode *inode = file_inode(file);
0b05b183
AA
617 struct fuse_conn *fc = get_fuse_conn(inode);
618 struct fuse_req *req;
619 struct fuse_forget_in inarg;
620
621 memset(&inarg, 0, sizeof(inarg));
622 inarg.nlookup = 1;
b111c8c0 623 req = fuse_get_req_nofail_nopages(fc, file);
0b05b183
AA
624 req->in.h.opcode = FUSE_FORGET;
625 req->in.h.nodeid = nodeid;
626 req->in.numargs = 1;
627 req->in.args[0].size = sizeof(inarg);
628 req->in.args[0].value = &inarg;
825d6d33 629 __clear_bit(FR_ISREPLY, &req->flags);
6a4e922c
EW
630 __fuse_request_send(fc, req);
631 /* ignore errors */
632 fuse_put_request(fc, req);
0b05b183
AA
633}
634
334f485d
MS
635/*
636 * Lock the request. Up to the next unlock_request() there mustn't be
637 * anything that could cause a page-fault. If the request was already
f9a2842e 638 * aborted bail out.
334f485d 639 */
dc00809a 640static int lock_request(struct fuse_req *req)
334f485d
MS
641{
642 int err = 0;
643 if (req) {
dc00809a 644 spin_lock(&req->waitq.lock);
825d6d33 645 if (test_bit(FR_ABORTED, &req->flags))
334f485d
MS
646 err = -ENOENT;
647 else
825d6d33 648 set_bit(FR_LOCKED, &req->flags);
dc00809a 649 spin_unlock(&req->waitq.lock);
334f485d
MS
650 }
651 return err;
652}
653
654/*
0d8e84b0
MS
655 * Unlock request. If it was aborted while locked, caller is responsible
656 * for unlocking and ending the request.
334f485d 657 */
dc00809a 658static int unlock_request(struct fuse_req *req)
334f485d 659{
0d8e84b0 660 int err = 0;
334f485d 661 if (req) {
dc00809a 662 spin_lock(&req->waitq.lock);
825d6d33 663 if (test_bit(FR_ABORTED, &req->flags))
0d8e84b0
MS
664 err = -ENOENT;
665 else
825d6d33 666 clear_bit(FR_LOCKED, &req->flags);
dc00809a 667 spin_unlock(&req->waitq.lock);
334f485d 668 }
0d8e84b0 669 return err;
334f485d
MS
670}
671
672struct fuse_copy_state {
673 int write;
674 struct fuse_req *req;
6c09e94a 675 struct iov_iter *iter;
dd3bb14f
MS
676 struct pipe_buffer *pipebufs;
677 struct pipe_buffer *currbuf;
678 struct pipe_inode_info *pipe;
334f485d 679 unsigned long nr_segs;
334f485d 680 struct page *pg;
334f485d 681 unsigned len;
c55a01d3 682 unsigned offset;
ce534fb0 683 unsigned move_pages:1;
334f485d
MS
684};
685
dc00809a 686static void fuse_copy_init(struct fuse_copy_state *cs, int write,
6c09e94a 687 struct iov_iter *iter)
334f485d
MS
688{
689 memset(cs, 0, sizeof(*cs));
690 cs->write = write;
6c09e94a 691 cs->iter = iter;
334f485d
MS
692}
693
694/* Unmap and put previous page of userspace buffer */
8bfc016d 695static void fuse_copy_finish(struct fuse_copy_state *cs)
334f485d 696{
dd3bb14f
MS
697 if (cs->currbuf) {
698 struct pipe_buffer *buf = cs->currbuf;
699
c55a01d3 700 if (cs->write)
c3021629 701 buf->len = PAGE_SIZE - cs->len;
dd3bb14f 702 cs->currbuf = NULL;
c55a01d3 703 } else if (cs->pg) {
334f485d
MS
704 if (cs->write) {
705 flush_dcache_page(cs->pg);
706 set_page_dirty_lock(cs->pg);
707 }
708 put_page(cs->pg);
334f485d 709 }
c55a01d3 710 cs->pg = NULL;
334f485d
MS
711}
712
713/*
714 * Get another pagefull of userspace buffer, and map it to kernel
715 * address space, and lock request
716 */
717static int fuse_copy_fill(struct fuse_copy_state *cs)
718{
c55a01d3 719 struct page *page;
334f485d
MS
720 int err;
721
dc00809a 722 err = unlock_request(cs->req);
0d8e84b0
MS
723 if (err)
724 return err;
725
334f485d 726 fuse_copy_finish(cs);
dd3bb14f
MS
727 if (cs->pipebufs) {
728 struct pipe_buffer *buf = cs->pipebufs;
729
c3021629 730 if (!cs->write) {
fba597db 731 err = pipe_buf_confirm(cs->pipe, buf);
c3021629
MS
732 if (err)
733 return err;
734
735 BUG_ON(!cs->nr_segs);
736 cs->currbuf = buf;
c55a01d3
MS
737 cs->pg = buf->page;
738 cs->offset = buf->offset;
c3021629 739 cs->len = buf->len;
c3021629
MS
740 cs->pipebufs++;
741 cs->nr_segs--;
742 } else {
c3021629
MS
743 if (cs->nr_segs == cs->pipe->buffers)
744 return -EIO;
745
746 page = alloc_page(GFP_HIGHUSER);
747 if (!page)
748 return -ENOMEM;
749
750 buf->page = page;
751 buf->offset = 0;
752 buf->len = 0;
753
754 cs->currbuf = buf;
c55a01d3
MS
755 cs->pg = page;
756 cs->offset = 0;
c3021629
MS
757 cs->len = PAGE_SIZE;
758 cs->pipebufs++;
759 cs->nr_segs++;
760 }
dd3bb14f 761 } else {
6c09e94a
AV
762 size_t off;
763 err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off);
dd3bb14f
MS
764 if (err < 0)
765 return err;
6c09e94a
AV
766 BUG_ON(!err);
767 cs->len = err;
768 cs->offset = off;
c55a01d3 769 cs->pg = page;
6c09e94a 770 iov_iter_advance(cs->iter, err);
334f485d 771 }
334f485d 772
dc00809a 773 return lock_request(cs->req);
334f485d
MS
774}
775
776/* Do as much copy to/from userspace buffer as we can */
8bfc016d 777static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
334f485d
MS
778{
779 unsigned ncpy = min(*size, cs->len);
780 if (val) {
c55a01d3
MS
781 void *pgaddr = kmap_atomic(cs->pg);
782 void *buf = pgaddr + cs->offset;
783
334f485d 784 if (cs->write)
c55a01d3 785 memcpy(buf, *val, ncpy);
334f485d 786 else
c55a01d3
MS
787 memcpy(*val, buf, ncpy);
788
789 kunmap_atomic(pgaddr);
334f485d
MS
790 *val += ncpy;
791 }
792 *size -= ncpy;
793 cs->len -= ncpy;
c55a01d3 794 cs->offset += ncpy;
334f485d
MS
795 return ncpy;
796}
797
ce534fb0
MS
798static int fuse_check_page(struct page *page)
799{
800 if (page_mapcount(page) ||
801 page->mapping != NULL ||
802 page_count(page) != 1 ||
803 (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
804 ~(1 << PG_locked |
805 1 << PG_referenced |
806 1 << PG_uptodate |
807 1 << PG_lru |
808 1 << PG_active |
809 1 << PG_reclaim))) {
810 printk(KERN_WARNING "fuse: trying to steal weird page\n");
811 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);
812 return 1;
813 }
814 return 0;
815}
816
817static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
818{
819 int err;
820 struct page *oldpage = *pagep;
821 struct page *newpage;
822 struct pipe_buffer *buf = cs->pipebufs;
ce534fb0 823
dc00809a 824 err = unlock_request(cs->req);
0d8e84b0
MS
825 if (err)
826 return err;
827
ce534fb0
MS
828 fuse_copy_finish(cs);
829
fba597db 830 err = pipe_buf_confirm(cs->pipe, buf);
ce534fb0
MS
831 if (err)
832 return err;
833
834 BUG_ON(!cs->nr_segs);
835 cs->currbuf = buf;
836 cs->len = buf->len;
837 cs->pipebufs++;
838 cs->nr_segs--;
839
840 if (cs->len != PAGE_SIZE)
841 goto out_fallback;
842
ca76f5b6 843 if (pipe_buf_steal(cs->pipe, buf) != 0)
ce534fb0
MS
844 goto out_fallback;
845
846 newpage = buf->page;
847
aa991b3b
MS
848 if (!PageUptodate(newpage))
849 SetPageUptodate(newpage);
ce534fb0
MS
850
851 ClearPageMappedToDisk(newpage);
852
853 if (fuse_check_page(newpage) != 0)
854 goto out_fallback_unlock;
855
ce534fb0
MS
856 /*
857 * This is a new and locked page, it shouldn't be mapped or
858 * have any special flags on it
859 */
860 if (WARN_ON(page_mapped(oldpage)))
861 goto out_fallback_unlock;
862 if (WARN_ON(page_has_private(oldpage)))
863 goto out_fallback_unlock;
864 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
865 goto out_fallback_unlock;
866 if (WARN_ON(PageMlocked(oldpage)))
867 goto out_fallback_unlock;
868
ef6a3c63 869 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
ce534fb0 870 if (err) {
ef6a3c63
MS
871 unlock_page(newpage);
872 return err;
ce534fb0 873 }
ef6a3c63 874
09cbfeaf 875 get_page(newpage);
ce534fb0
MS
876
877 if (!(buf->flags & PIPE_BUF_FLAG_LRU))
878 lru_cache_add_file(newpage);
879
880 err = 0;
dc00809a 881 spin_lock(&cs->req->waitq.lock);
825d6d33 882 if (test_bit(FR_ABORTED, &cs->req->flags))
ce534fb0
MS
883 err = -ENOENT;
884 else
885 *pagep = newpage;
dc00809a 886 spin_unlock(&cs->req->waitq.lock);
ce534fb0
MS
887
888 if (err) {
889 unlock_page(newpage);
09cbfeaf 890 put_page(newpage);
ce534fb0
MS
891 return err;
892 }
893
894 unlock_page(oldpage);
09cbfeaf 895 put_page(oldpage);
ce534fb0
MS
896 cs->len = 0;
897
898 return 0;
899
900out_fallback_unlock:
901 unlock_page(newpage);
902out_fallback:
c55a01d3
MS
903 cs->pg = buf->page;
904 cs->offset = buf->offset;
ce534fb0 905
dc00809a 906 err = lock_request(cs->req);
ce534fb0
MS
907 if (err)
908 return err;
909
910 return 1;
911}
912
c3021629
MS
913static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
914 unsigned offset, unsigned count)
915{
916 struct pipe_buffer *buf;
0d8e84b0 917 int err;
c3021629
MS
918
919 if (cs->nr_segs == cs->pipe->buffers)
920 return -EIO;
921
dc00809a 922 err = unlock_request(cs->req);
0d8e84b0
MS
923 if (err)
924 return err;
925
c3021629
MS
926 fuse_copy_finish(cs);
927
928 buf = cs->pipebufs;
09cbfeaf 929 get_page(page);
c3021629
MS
930 buf->page = page;
931 buf->offset = offset;
932 buf->len = count;
933
934 cs->pipebufs++;
935 cs->nr_segs++;
936 cs->len = 0;
937
938 return 0;
939}
940
334f485d
MS
941/*
942 * Copy a page in the request to/from the userspace buffer. Must be
943 * done atomically
944 */
ce534fb0 945static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
8bfc016d 946 unsigned offset, unsigned count, int zeroing)
334f485d 947{
ce534fb0
MS
948 int err;
949 struct page *page = *pagep;
950
b6777c40
MS
951 if (page && zeroing && count < PAGE_SIZE)
952 clear_highpage(page);
953
334f485d 954 while (count) {
c3021629
MS
955 if (cs->write && cs->pipebufs && page) {
956 return fuse_ref_page(cs, page, offset, count);
957 } else if (!cs->len) {
ce534fb0
MS
958 if (cs->move_pages && page &&
959 offset == 0 && count == PAGE_SIZE) {
960 err = fuse_try_move_page(cs, pagep);
961 if (err <= 0)
962 return err;
963 } else {
964 err = fuse_copy_fill(cs);
965 if (err)
966 return err;
967 }
1729a16c 968 }
334f485d 969 if (page) {
2408f6ef 970 void *mapaddr = kmap_atomic(page);
334f485d
MS
971 void *buf = mapaddr + offset;
972 offset += fuse_copy_do(cs, &buf, &count);
2408f6ef 973 kunmap_atomic(mapaddr);
334f485d
MS
974 } else
975 offset += fuse_copy_do(cs, NULL, &count);
976 }
977 if (page && !cs->write)
978 flush_dcache_page(page);
979 return 0;
980}
981
982/* Copy pages in the request to/from userspace buffer */
983static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
984 int zeroing)
985{
986 unsigned i;
987 struct fuse_req *req = cs->req;
334f485d
MS
988
989 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
ce534fb0 990 int err;
85f40aec
MP
991 unsigned offset = req->page_descs[i].offset;
992 unsigned count = min(nbytes, req->page_descs[i].length);
ce534fb0
MS
993
994 err = fuse_copy_page(cs, &req->pages[i], offset, count,
995 zeroing);
334f485d
MS
996 if (err)
997 return err;
998
999 nbytes -= count;
334f485d
MS
1000 }
1001 return 0;
1002}
1003
1004/* Copy a single argument in the request to/from userspace buffer */
1005static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
1006{
1007 while (size) {
1729a16c
MS
1008 if (!cs->len) {
1009 int err = fuse_copy_fill(cs);
1010 if (err)
1011 return err;
1012 }
334f485d
MS
1013 fuse_copy_do(cs, &val, &size);
1014 }
1015 return 0;
1016}
1017
1018/* Copy request arguments to/from userspace buffer */
1019static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
1020 unsigned argpages, struct fuse_arg *args,
1021 int zeroing)
1022{
1023 int err = 0;
1024 unsigned i;
1025
1026 for (i = 0; !err && i < numargs; i++) {
1027 struct fuse_arg *arg = &args[i];
1028 if (i == numargs - 1 && argpages)
1029 err = fuse_copy_pages(cs, arg->size, zeroing);
1030 else
1031 err = fuse_copy_one(cs, arg->value, arg->size);
1032 }
1033 return err;
1034}
1035
f88996a9 1036static int forget_pending(struct fuse_iqueue *fiq)
07e77dca 1037{
f88996a9 1038 return fiq->forget_list_head.next != NULL;
07e77dca
MS
1039}
1040
f88996a9 1041static int request_pending(struct fuse_iqueue *fiq)
a4d27e75 1042{
f88996a9
MS
1043 return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) ||
1044 forget_pending(fiq);
a4d27e75
MS
1045}
1046
a4d27e75
MS
1047/*
1048 * Transfer an interrupt request to userspace
1049 *
1050 * Unlike other requests this is assembled on demand, without a need
1051 * to allocate a separate fuse_req structure.
1052 *
fd22d62e 1053 * Called with fiq->waitq.lock held, releases it
a4d27e75 1054 */
fd22d62e
MS
1055static int fuse_read_interrupt(struct fuse_iqueue *fiq,
1056 struct fuse_copy_state *cs,
c3021629 1057 size_t nbytes, struct fuse_req *req)
fd22d62e 1058__releases(fiq->waitq.lock)
a4d27e75 1059{
a4d27e75
MS
1060 struct fuse_in_header ih;
1061 struct fuse_interrupt_in arg;
1062 unsigned reqsize = sizeof(ih) + sizeof(arg);
1063 int err;
1064
1065 list_del_init(&req->intr_entry);
4ce60812 1066 req->intr_unique = fuse_get_unique(fiq);
a4d27e75
MS
1067 memset(&ih, 0, sizeof(ih));
1068 memset(&arg, 0, sizeof(arg));
1069 ih.len = reqsize;
1070 ih.opcode = FUSE_INTERRUPT;
1071 ih.unique = req->intr_unique;
1072 arg.unique = req->in.h.unique;
1073
4ce60812 1074 spin_unlock(&fiq->waitq.lock);
c3021629 1075 if (nbytes < reqsize)
a4d27e75
MS
1076 return -EINVAL;
1077
c3021629 1078 err = fuse_copy_one(cs, &ih, sizeof(ih));
a4d27e75 1079 if (!err)
c3021629
MS
1080 err = fuse_copy_one(cs, &arg, sizeof(arg));
1081 fuse_copy_finish(cs);
a4d27e75
MS
1082
1083 return err ? err : reqsize;
1084}
1085
f88996a9 1086static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
02c048b9
MS
1087 unsigned max,
1088 unsigned *countp)
07e77dca 1089{
f88996a9 1090 struct fuse_forget_link *head = fiq->forget_list_head.next;
02c048b9
MS
1091 struct fuse_forget_link **newhead = &head;
1092 unsigned count;
07e77dca 1093
02c048b9
MS
1094 for (count = 0; *newhead != NULL && count < max; count++)
1095 newhead = &(*newhead)->next;
1096
f88996a9 1097 fiq->forget_list_head.next = *newhead;
02c048b9 1098 *newhead = NULL;
f88996a9
MS
1099 if (fiq->forget_list_head.next == NULL)
1100 fiq->forget_list_tail = &fiq->forget_list_head;
07e77dca 1101
02c048b9
MS
1102 if (countp != NULL)
1103 *countp = count;
1104
1105 return head;
07e77dca
MS
1106}
1107
fd22d62e 1108static int fuse_read_single_forget(struct fuse_iqueue *fiq,
07e77dca
MS
1109 struct fuse_copy_state *cs,
1110 size_t nbytes)
fd22d62e 1111__releases(fiq->waitq.lock)
07e77dca
MS
1112{
1113 int err;
f88996a9 1114 struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
07e77dca 1115 struct fuse_forget_in arg = {
02c048b9 1116 .nlookup = forget->forget_one.nlookup,
07e77dca
MS
1117 };
1118 struct fuse_in_header ih = {
1119 .opcode = FUSE_FORGET,
02c048b9 1120 .nodeid = forget->forget_one.nodeid,
f88996a9 1121 .unique = fuse_get_unique(fiq),
07e77dca
MS
1122 .len = sizeof(ih) + sizeof(arg),
1123 };
1124
4ce60812 1125 spin_unlock(&fiq->waitq.lock);
07e77dca
MS
1126 kfree(forget);
1127 if (nbytes < ih.len)
1128 return -EINVAL;
1129
1130 err = fuse_copy_one(cs, &ih, sizeof(ih));
1131 if (!err)
1132 err = fuse_copy_one(cs, &arg, sizeof(arg));
1133 fuse_copy_finish(cs);
1134
1135 if (err)
1136 return err;
1137
1138 return ih.len;
1139}
1140
fd22d62e 1141static int fuse_read_batch_forget(struct fuse_iqueue *fiq,
02c048b9 1142 struct fuse_copy_state *cs, size_t nbytes)
fd22d62e 1143__releases(fiq->waitq.lock)
02c048b9
MS
1144{
1145 int err;
1146 unsigned max_forgets;
1147 unsigned count;
1148 struct fuse_forget_link *head;
1149 struct fuse_batch_forget_in arg = { .count = 0 };
1150 struct fuse_in_header ih = {
1151 .opcode = FUSE_BATCH_FORGET,
f88996a9 1152 .unique = fuse_get_unique(fiq),
02c048b9
MS
1153 .len = sizeof(ih) + sizeof(arg),
1154 };
1155
1156 if (nbytes < ih.len) {
4ce60812 1157 spin_unlock(&fiq->waitq.lock);
02c048b9
MS
1158 return -EINVAL;
1159 }
1160
1161 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
f88996a9 1162 head = dequeue_forget(fiq, max_forgets, &count);
4ce60812 1163 spin_unlock(&fiq->waitq.lock);
02c048b9
MS
1164
1165 arg.count = count;
1166 ih.len += count * sizeof(struct fuse_forget_one);
1167 err = fuse_copy_one(cs, &ih, sizeof(ih));
1168 if (!err)
1169 err = fuse_copy_one(cs, &arg, sizeof(arg));
1170
1171 while (head) {
1172 struct fuse_forget_link *forget = head;
1173
1174 if (!err) {
1175 err = fuse_copy_one(cs, &forget->forget_one,
1176 sizeof(forget->forget_one));
1177 }
1178 head = forget->next;
1179 kfree(forget);
1180 }
1181
1182 fuse_copy_finish(cs);
1183
1184 if (err)
1185 return err;
1186
1187 return ih.len;
1188}
1189
fd22d62e
MS
1190static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq,
1191 struct fuse_copy_state *cs,
02c048b9 1192 size_t nbytes)
fd22d62e 1193__releases(fiq->waitq.lock)
02c048b9 1194{
f88996a9 1195 if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
fd22d62e 1196 return fuse_read_single_forget(fiq, cs, nbytes);
02c048b9 1197 else
fd22d62e 1198 return fuse_read_batch_forget(fiq, cs, nbytes);
02c048b9
MS
1199}
1200
334f485d
MS
1201/*
1202 * Read a single request into the userspace filesystem's buffer. This
1203 * function waits until a request is available, then removes it from
1204 * the pending list and copies request data to userspace buffer. If
f9a2842e
MS
1205 * no reply is needed (FORGET) or request has been aborted or there
1206 * was an error during the copying then it's finished by calling
334f485d
MS
1207 * request_end(). Otherwise add it to the processing list, and set
1208 * the 'sent' flag.
1209 */
c3696046 1210static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file,
c3021629 1211 struct fuse_copy_state *cs, size_t nbytes)
334f485d 1212{
82cbdcd3 1213 ssize_t err;
c3696046 1214 struct fuse_conn *fc = fud->fc;
f88996a9 1215 struct fuse_iqueue *fiq = &fc->iq;
c3696046 1216 struct fuse_pqueue *fpq = &fud->pq;
334f485d
MS
1217 struct fuse_req *req;
1218 struct fuse_in *in;
334f485d
MS
1219 unsigned reqsize;
1220
1d3d752b 1221 restart:
4ce60812 1222 spin_lock(&fiq->waitq.lock);
e5ac1d1e 1223 err = -EAGAIN;
e16714d8 1224 if ((file->f_flags & O_NONBLOCK) && fiq->connected &&
f88996a9 1225 !request_pending(fiq))
e5ac1d1e
JD
1226 goto err_unlock;
1227
5250921b
MS
1228 err = wait_event_interruptible_exclusive_locked(fiq->waitq,
1229 !fiq->connected || request_pending(fiq));
1230 if (err)
1231 goto err_unlock;
1232
334f485d 1233 err = -ENODEV;
e16714d8 1234 if (!fiq->connected)
334f485d 1235 goto err_unlock;
334f485d 1236
f88996a9
MS
1237 if (!list_empty(&fiq->interrupts)) {
1238 req = list_entry(fiq->interrupts.next, struct fuse_req,
a4d27e75 1239 intr_entry);
fd22d62e 1240 return fuse_read_interrupt(fiq, cs, nbytes, req);
a4d27e75
MS
1241 }
1242
f88996a9
MS
1243 if (forget_pending(fiq)) {
1244 if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
fd22d62e 1245 return fuse_read_forget(fc, fiq, cs, nbytes);
07e77dca 1246
f88996a9
MS
1247 if (fiq->forget_batch <= -8)
1248 fiq->forget_batch = 16;
07e77dca
MS
1249 }
1250
f88996a9 1251 req = list_entry(fiq->pending.next, struct fuse_req, list);
33e14b4d 1252 clear_bit(FR_PENDING, &req->flags);
ef759258 1253 list_del_init(&req->list);
4ce60812
MS
1254 spin_unlock(&fiq->waitq.lock);
1255
334f485d 1256 in = &req->in;
1d3d752b
MS
1257 reqsize = in->h.len;
1258 /* If request is too large, reply with an error and restart the read */
c3021629 1259 if (nbytes < reqsize) {
1d3d752b
MS
1260 req->out.h.error = -EIO;
1261 /* SETXATTR is special, since it may contain too large data */
1262 if (in->h.opcode == FUSE_SETXATTR)
1263 req->out.h.error = -E2BIG;
1264 request_end(fc, req);
1265 goto restart;
334f485d 1266 }
45a91cb1 1267 spin_lock(&fpq->lock);
82cbdcd3 1268 list_add(&req->list, &fpq->io);
45a91cb1 1269 spin_unlock(&fpq->lock);
c3021629
MS
1270 cs->req = req;
1271 err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1d3d752b 1272 if (!err)
c3021629 1273 err = fuse_copy_args(cs, in->numargs, in->argpages,
1d3d752b 1274 (struct fuse_arg *) in->args, 0);
c3021629 1275 fuse_copy_finish(cs);
45a91cb1 1276 spin_lock(&fpq->lock);
825d6d33 1277 clear_bit(FR_LOCKED, &req->flags);
e96edd94 1278 if (!fpq->connected) {
82cbdcd3
MS
1279 err = -ENODEV;
1280 goto out_end;
c9c9d7df 1281 }
334f485d 1282 if (err) {
c9c9d7df 1283 req->out.h.error = -EIO;
82cbdcd3 1284 goto out_end;
334f485d 1285 }
825d6d33 1286 if (!test_bit(FR_ISREPLY, &req->flags)) {
82cbdcd3
MS
1287 err = reqsize;
1288 goto out_end;
334f485d 1289 }
82cbdcd3 1290 list_move_tail(&req->list, &fpq->processing);
45a91cb1 1291 spin_unlock(&fpq->lock);
82cbdcd3
MS
1292 set_bit(FR_SENT, &req->flags);
1293 /* matches barrier in request_wait_answer() */
1294 smp_mb__after_atomic();
1295 if (test_bit(FR_INTERRUPTED, &req->flags))
1296 queue_interrupt(fiq, req);
82cbdcd3 1297
334f485d
MS
1298 return reqsize;
1299
82cbdcd3 1300out_end:
77cd9d48
MS
1301 if (!test_bit(FR_PRIVATE, &req->flags))
1302 list_del_init(&req->list);
45a91cb1 1303 spin_unlock(&fpq->lock);
82cbdcd3
MS
1304 request_end(fc, req);
1305 return err;
1306
334f485d 1307 err_unlock:
4ce60812 1308 spin_unlock(&fiq->waitq.lock);
334f485d
MS
1309 return err;
1310}
1311
94e4fe2c
TVB
1312static int fuse_dev_open(struct inode *inode, struct file *file)
1313{
1314 /*
1315 * The fuse device's file's private_data is used to hold
1316 * the fuse_conn(ection) when it is mounted, and is used to
1317 * keep track of whether the file has been mounted already.
1318 */
1319 file->private_data = NULL;
1320 return 0;
1321}
1322
fbdbacca 1323static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
c3021629
MS
1324{
1325 struct fuse_copy_state cs;
1326 struct file *file = iocb->ki_filp;
cc080e9e
MS
1327 struct fuse_dev *fud = fuse_get_dev(file);
1328
1329 if (!fud)
c3021629
MS
1330 return -EPERM;
1331
fbdbacca
AV
1332 if (!iter_is_iovec(to))
1333 return -EINVAL;
1334
dc00809a 1335 fuse_copy_init(&cs, 1, to);
c3021629 1336
c3696046 1337 return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to));
c3021629
MS
1338}
1339
c3021629
MS
1340static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1341 struct pipe_inode_info *pipe,
1342 size_t len, unsigned int flags)
1343{
d82718e3 1344 int total, ret;
c3021629 1345 int page_nr = 0;
c3021629
MS
1346 struct pipe_buffer *bufs;
1347 struct fuse_copy_state cs;
cc080e9e
MS
1348 struct fuse_dev *fud = fuse_get_dev(in);
1349
1350 if (!fud)
c3021629
MS
1351 return -EPERM;
1352
07e77dca 1353 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
c3021629
MS
1354 if (!bufs)
1355 return -ENOMEM;
1356
dc00809a 1357 fuse_copy_init(&cs, 1, NULL);
c3021629
MS
1358 cs.pipebufs = bufs;
1359 cs.pipe = pipe;
c3696046 1360 ret = fuse_dev_do_read(fud, in, &cs, len);
c3021629
MS
1361 if (ret < 0)
1362 goto out;
1363
c3021629
MS
1364 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1365 ret = -EIO;
d82718e3 1366 goto out;
c3021629
MS
1367 }
1368
d82718e3 1369 for (ret = total = 0; page_nr < cs.nr_segs; total += ret) {
28a625cb
MS
1370 /*
1371 * Need to be careful about this. Having buf->ops in module
1372 * code can Oops if the buffer persists after module unload.
1373 */
d82718e3
AV
1374 bufs[page_nr].ops = &nosteal_pipe_buf_ops;
1375 ret = add_to_pipe(pipe, &bufs[page_nr++]);
1376 if (unlikely(ret < 0))
1377 break;
c3021629 1378 }
d82718e3
AV
1379 if (total)
1380 ret = total;
c3021629
MS
1381out:
1382 for (; page_nr < cs.nr_segs; page_nr++)
09cbfeaf 1383 put_page(bufs[page_nr].page);
c3021629
MS
1384
1385 kfree(bufs);
1386 return ret;
1387}
1388
95668a69
TH
1389static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1390 struct fuse_copy_state *cs)
1391{
1392 struct fuse_notify_poll_wakeup_out outarg;
f6d47a17 1393 int err = -EINVAL;
95668a69
TH
1394
1395 if (size != sizeof(outarg))
f6d47a17 1396 goto err;
95668a69
TH
1397
1398 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1399 if (err)
f6d47a17 1400 goto err;
95668a69 1401
f6d47a17 1402 fuse_copy_finish(cs);
95668a69 1403 return fuse_notify_poll_wakeup(fc, &outarg);
f6d47a17
MS
1404
1405err:
1406 fuse_copy_finish(cs);
1407 return err;
95668a69
TH
1408}
1409
3b463ae0
JM
1410static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1411 struct fuse_copy_state *cs)
1412{
1413 struct fuse_notify_inval_inode_out outarg;
1414 int err = -EINVAL;
1415
1416 if (size != sizeof(outarg))
1417 goto err;
1418
1419 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1420 if (err)
1421 goto err;
1422 fuse_copy_finish(cs);
1423
1424 down_read(&fc->killsb);
1425 err = -ENOENT;
b21dda43
MS
1426 if (fc->sb) {
1427 err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1428 outarg.off, outarg.len);
1429 }
3b463ae0
JM
1430 up_read(&fc->killsb);
1431 return err;
1432
1433err:
1434 fuse_copy_finish(cs);
1435 return err;
1436}
1437
1438static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1439 struct fuse_copy_state *cs)
1440{
1441 struct fuse_notify_inval_entry_out outarg;
b2d82ee3
FW
1442 int err = -ENOMEM;
1443 char *buf;
3b463ae0
JM
1444 struct qstr name;
1445
b2d82ee3
FW
1446 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1447 if (!buf)
1448 goto err;
1449
1450 err = -EINVAL;
3b463ae0
JM
1451 if (size < sizeof(outarg))
1452 goto err;
1453
1454 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1455 if (err)
1456 goto err;
1457
1458 err = -ENAMETOOLONG;
1459 if (outarg.namelen > FUSE_NAME_MAX)
1460 goto err;
1461
c2183d1e
MS
1462 err = -EINVAL;
1463 if (size != sizeof(outarg) + outarg.namelen + 1)
1464 goto err;
1465
3b463ae0
JM
1466 name.name = buf;
1467 name.len = outarg.namelen;
1468 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1469 if (err)
1470 goto err;
1471 fuse_copy_finish(cs);
1472 buf[outarg.namelen] = 0;
3b463ae0
JM
1473
1474 down_read(&fc->killsb);
1475 err = -ENOENT;
b21dda43 1476 if (fc->sb)
451d0f59
JM
1477 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1478 up_read(&fc->killsb);
1479 kfree(buf);
1480 return err;
1481
1482err:
1483 kfree(buf);
1484 fuse_copy_finish(cs);
1485 return err;
1486}
1487
1488static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1489 struct fuse_copy_state *cs)
1490{
1491 struct fuse_notify_delete_out outarg;
1492 int err = -ENOMEM;
1493 char *buf;
1494 struct qstr name;
1495
1496 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1497 if (!buf)
1498 goto err;
1499
1500 err = -EINVAL;
1501 if (size < sizeof(outarg))
1502 goto err;
1503
1504 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1505 if (err)
1506 goto err;
1507
1508 err = -ENAMETOOLONG;
1509 if (outarg.namelen > FUSE_NAME_MAX)
1510 goto err;
1511
1512 err = -EINVAL;
1513 if (size != sizeof(outarg) + outarg.namelen + 1)
1514 goto err;
1515
1516 name.name = buf;
1517 name.len = outarg.namelen;
1518 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1519 if (err)
1520 goto err;
1521 fuse_copy_finish(cs);
1522 buf[outarg.namelen] = 0;
451d0f59
JM
1523
1524 down_read(&fc->killsb);
1525 err = -ENOENT;
1526 if (fc->sb)
1527 err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1528 outarg.child, &name);
3b463ae0 1529 up_read(&fc->killsb);
b2d82ee3 1530 kfree(buf);
3b463ae0
JM
1531 return err;
1532
1533err:
b2d82ee3 1534 kfree(buf);
3b463ae0
JM
1535 fuse_copy_finish(cs);
1536 return err;
1537}
1538
a1d75f25
MS
1539static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1540 struct fuse_copy_state *cs)
1541{
1542 struct fuse_notify_store_out outarg;
1543 struct inode *inode;
1544 struct address_space *mapping;
1545 u64 nodeid;
1546 int err;
1547 pgoff_t index;
1548 unsigned int offset;
1549 unsigned int num;
1550 loff_t file_size;
1551 loff_t end;
1552
1553 err = -EINVAL;
1554 if (size < sizeof(outarg))
1555 goto out_finish;
1556
1557 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1558 if (err)
1559 goto out_finish;
1560
1561 err = -EINVAL;
1562 if (size - sizeof(outarg) != outarg.size)
1563 goto out_finish;
1564
1565 nodeid = outarg.nodeid;
1566
1567 down_read(&fc->killsb);
1568
1569 err = -ENOENT;
1570 if (!fc->sb)
1571 goto out_up_killsb;
1572
1573 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1574 if (!inode)
1575 goto out_up_killsb;
1576
1577 mapping = inode->i_mapping;
09cbfeaf
KS
1578 index = outarg.offset >> PAGE_SHIFT;
1579 offset = outarg.offset & ~PAGE_MASK;
a1d75f25
MS
1580 file_size = i_size_read(inode);
1581 end = outarg.offset + outarg.size;
1582 if (end > file_size) {
1583 file_size = end;
1584 fuse_write_update_size(inode, file_size);
1585 }
1586
1587 num = outarg.size;
1588 while (num) {
1589 struct page *page;
1590 unsigned int this_num;
1591
1592 err = -ENOMEM;
1593 page = find_or_create_page(mapping, index,
1594 mapping_gfp_mask(mapping));
1595 if (!page)
1596 goto out_iput;
1597
09cbfeaf 1598 this_num = min_t(unsigned, num, PAGE_SIZE - offset);
a1d75f25 1599 err = fuse_copy_page(cs, &page, offset, this_num, 0);
063ec1e5 1600 if (!err && offset == 0 &&
09cbfeaf 1601 (this_num == PAGE_SIZE || file_size == end))
a1d75f25
MS
1602 SetPageUptodate(page);
1603 unlock_page(page);
09cbfeaf 1604 put_page(page);
a1d75f25
MS
1605
1606 if (err)
1607 goto out_iput;
1608
1609 num -= this_num;
1610 offset = 0;
1611 index++;
1612 }
1613
1614 err = 0;
1615
1616out_iput:
1617 iput(inode);
1618out_up_killsb:
1619 up_read(&fc->killsb);
1620out_finish:
1621 fuse_copy_finish(cs);
1622 return err;
1623}
1624
2d45ba38
MS
1625static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
1626{
b745bc85 1627 release_pages(req->pages, req->num_pages, false);
2d45ba38
MS
1628}
1629
1630static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1631 struct fuse_notify_retrieve_out *outarg)
1632{
1633 int err;
1634 struct address_space *mapping = inode->i_mapping;
1635 struct fuse_req *req;
1636 pgoff_t index;
1637 loff_t file_size;
1638 unsigned int num;
1639 unsigned int offset;
0157443c 1640 size_t total_len = 0;
4d53dc99 1641 int num_pages;
2d45ba38 1642
09cbfeaf 1643 offset = outarg->offset & ~PAGE_MASK;
4d53dc99
MP
1644 file_size = i_size_read(inode);
1645
1646 num = outarg->size;
1647 if (outarg->offset > file_size)
1648 num = 0;
1649 else if (outarg->offset + num > file_size)
1650 num = file_size - outarg->offset;
1651
1652 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1653 num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
1654
1655 req = fuse_get_req(fc, num_pages);
2d45ba38
MS
1656 if (IS_ERR(req))
1657 return PTR_ERR(req);
1658
2d45ba38
MS
1659 req->in.h.opcode = FUSE_NOTIFY_REPLY;
1660 req->in.h.nodeid = outarg->nodeid;
1661 req->in.numargs = 2;
1662 req->in.argpages = 1;
b2430d75 1663 req->page_descs[0].offset = offset;
2d45ba38
MS
1664 req->end = fuse_retrieve_end;
1665
09cbfeaf 1666 index = outarg->offset >> PAGE_SHIFT;
2d45ba38 1667
4d53dc99 1668 while (num && req->num_pages < num_pages) {
2d45ba38
MS
1669 struct page *page;
1670 unsigned int this_num;
1671
1672 page = find_get_page(mapping, index);
1673 if (!page)
1674 break;
1675
09cbfeaf 1676 this_num = min_t(unsigned, num, PAGE_SIZE - offset);
2d45ba38 1677 req->pages[req->num_pages] = page;
85f40aec 1678 req->page_descs[req->num_pages].length = this_num;
2d45ba38
MS
1679 req->num_pages++;
1680
c9e67d48 1681 offset = 0;
2d45ba38
MS
1682 num -= this_num;
1683 total_len += this_num;
48706d0a 1684 index++;
2d45ba38
MS
1685 }
1686 req->misc.retrieve_in.offset = outarg->offset;
1687 req->misc.retrieve_in.size = total_len;
1688 req->in.args[0].size = sizeof(req->misc.retrieve_in);
1689 req->in.args[0].value = &req->misc.retrieve_in;
1690 req->in.args[1].size = total_len;
1691
1692 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1693 if (err)
1694 fuse_retrieve_end(fc, req);
1695
1696 return err;
1697}
1698
1699static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1700 struct fuse_copy_state *cs)
1701{
1702 struct fuse_notify_retrieve_out outarg;
1703 struct inode *inode;
1704 int err;
1705
1706 err = -EINVAL;
1707 if (size != sizeof(outarg))
1708 goto copy_finish;
1709
1710 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1711 if (err)
1712 goto copy_finish;
1713
1714 fuse_copy_finish(cs);
1715
1716 down_read(&fc->killsb);
1717 err = -ENOENT;
1718 if (fc->sb) {
1719 u64 nodeid = outarg.nodeid;
1720
1721 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1722 if (inode) {
1723 err = fuse_retrieve(fc, inode, &outarg);
1724 iput(inode);
1725 }
1726 }
1727 up_read(&fc->killsb);
1728
1729 return err;
1730
1731copy_finish:
1732 fuse_copy_finish(cs);
1733 return err;
1734}
1735
8599396b
TH
1736static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1737 unsigned int size, struct fuse_copy_state *cs)
1738{
0d278362
MS
1739 /* Don't try to move pages (yet) */
1740 cs->move_pages = 0;
1741
8599396b 1742 switch (code) {
95668a69
TH
1743 case FUSE_NOTIFY_POLL:
1744 return fuse_notify_poll(fc, size, cs);
1745
3b463ae0
JM
1746 case FUSE_NOTIFY_INVAL_INODE:
1747 return fuse_notify_inval_inode(fc, size, cs);
1748
1749 case FUSE_NOTIFY_INVAL_ENTRY:
1750 return fuse_notify_inval_entry(fc, size, cs);
1751
a1d75f25
MS
1752 case FUSE_NOTIFY_STORE:
1753 return fuse_notify_store(fc, size, cs);
1754
2d45ba38
MS
1755 case FUSE_NOTIFY_RETRIEVE:
1756 return fuse_notify_retrieve(fc, size, cs);
1757
451d0f59
JM
1758 case FUSE_NOTIFY_DELETE:
1759 return fuse_notify_delete(fc, size, cs);
1760
8599396b 1761 default:
f6d47a17 1762 fuse_copy_finish(cs);
8599396b
TH
1763 return -EINVAL;
1764 }
1765}
1766
334f485d 1767/* Look up request on processing list by unique ID */
3a2b5b9c 1768static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
334f485d 1769{
05726aca 1770 struct fuse_req *req;
334f485d 1771
3a2b5b9c 1772 list_for_each_entry(req, &fpq->processing, list) {
a4d27e75 1773 if (req->in.h.unique == unique || req->intr_unique == unique)
334f485d
MS
1774 return req;
1775 }
1776 return NULL;
1777}
1778
1779static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1780 unsigned nbytes)
1781{
1782 unsigned reqsize = sizeof(struct fuse_out_header);
1783
1784 if (out->h.error)
1785 return nbytes != reqsize ? -EINVAL : 0;
1786
1787 reqsize += len_args(out->numargs, out->args);
1788
1789 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1790 return -EINVAL;
1791 else if (reqsize > nbytes) {
1792 struct fuse_arg *lastarg = &out->args[out->numargs-1];
1793 unsigned diffsize = reqsize - nbytes;
1794 if (diffsize > lastarg->size)
1795 return -EINVAL;
1796 lastarg->size -= diffsize;
1797 }
1798 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1799 out->page_zeroing);
1800}
1801
1802/*
1803 * Write a single reply to a request. First the header is copied from
1804 * the write buffer. The request is then searched on the processing
1805 * list by the unique ID found in the header. If found, then remove
1806 * it from the list and copy the rest of the buffer to the request.
1807 * The request is finished by calling request_end()
1808 */
c3696046 1809static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
dd3bb14f 1810 struct fuse_copy_state *cs, size_t nbytes)
334f485d
MS
1811{
1812 int err;
c3696046
MS
1813 struct fuse_conn *fc = fud->fc;
1814 struct fuse_pqueue *fpq = &fud->pq;
334f485d
MS
1815 struct fuse_req *req;
1816 struct fuse_out_header oh;
334f485d 1817
334f485d
MS
1818 if (nbytes < sizeof(struct fuse_out_header))
1819 return -EINVAL;
1820
dd3bb14f 1821 err = fuse_copy_one(cs, &oh, sizeof(oh));
334f485d
MS
1822 if (err)
1823 goto err_finish;
8599396b
TH
1824
1825 err = -EINVAL;
1826 if (oh.len != nbytes)
1827 goto err_finish;
1828
1829 /*
1830 * Zero oh.unique indicates unsolicited notification message
1831 * and error contains notification code.
1832 */
1833 if (!oh.unique) {
dd3bb14f 1834 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
8599396b
TH
1835 return err ? err : nbytes;
1836 }
1837
334f485d 1838 err = -EINVAL;
8599396b 1839 if (oh.error <= -1000 || oh.error > 0)
334f485d
MS
1840 goto err_finish;
1841
45a91cb1 1842 spin_lock(&fpq->lock);
69a53bf2 1843 err = -ENOENT;
e96edd94 1844 if (!fpq->connected)
45a91cb1 1845 goto err_unlock_pq;
69a53bf2 1846
3a2b5b9c 1847 req = request_find(fpq, oh.unique);
334f485d 1848 if (!req)
45a91cb1 1849 goto err_unlock_pq;
334f485d 1850
a4d27e75
MS
1851 /* Is it an interrupt reply? */
1852 if (req->intr_unique == oh.unique) {
45a91cb1
MS
1853 spin_unlock(&fpq->lock);
1854
a4d27e75
MS
1855 err = -EINVAL;
1856 if (nbytes != sizeof(struct fuse_out_header))
46c34a34 1857 goto err_finish;
a4d27e75
MS
1858
1859 if (oh.error == -ENOSYS)
1860 fc->no_interrupt = 1;
1861 else if (oh.error == -EAGAIN)
f88996a9 1862 queue_interrupt(&fc->iq, req);
a4d27e75 1863
dd3bb14f 1864 fuse_copy_finish(cs);
a4d27e75
MS
1865 return nbytes;
1866 }
1867
33e14b4d 1868 clear_bit(FR_SENT, &req->flags);
3a2b5b9c 1869 list_move(&req->list, &fpq->io);
334f485d 1870 req->out.h = oh;
825d6d33 1871 set_bit(FR_LOCKED, &req->flags);
45a91cb1 1872 spin_unlock(&fpq->lock);
dd3bb14f 1873 cs->req = req;
ce534fb0
MS
1874 if (!req->out.page_replace)
1875 cs->move_pages = 0;
334f485d 1876
dd3bb14f
MS
1877 err = copy_out_args(cs, &req->out, nbytes);
1878 fuse_copy_finish(cs);
334f485d 1879
45a91cb1 1880 spin_lock(&fpq->lock);
825d6d33 1881 clear_bit(FR_LOCKED, &req->flags);
e96edd94 1882 if (!fpq->connected)
0d8e84b0
MS
1883 err = -ENOENT;
1884 else if (err)
334f485d 1885 req->out.h.error = -EIO;
77cd9d48
MS
1886 if (!test_bit(FR_PRIVATE, &req->flags))
1887 list_del_init(&req->list);
45a91cb1 1888 spin_unlock(&fpq->lock);
46c34a34 1889
334f485d
MS
1890 request_end(fc, req);
1891
1892 return err ? err : nbytes;
1893
45a91cb1
MS
1894 err_unlock_pq:
1895 spin_unlock(&fpq->lock);
334f485d 1896 err_finish:
dd3bb14f 1897 fuse_copy_finish(cs);
334f485d
MS
1898 return err;
1899}
1900
fbdbacca 1901static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
dd3bb14f
MS
1902{
1903 struct fuse_copy_state cs;
cc080e9e
MS
1904 struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp);
1905
1906 if (!fud)
dd3bb14f
MS
1907 return -EPERM;
1908
fbdbacca
AV
1909 if (!iter_is_iovec(from))
1910 return -EINVAL;
1911
dc00809a 1912 fuse_copy_init(&cs, 0, from);
dd3bb14f 1913
c3696046 1914 return fuse_dev_do_write(fud, &cs, iov_iter_count(from));
dd3bb14f
MS
1915}
1916
1917static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1918 struct file *out, loff_t *ppos,
1919 size_t len, unsigned int flags)
1920{
1921 unsigned nbuf;
1922 unsigned idx;
1923 struct pipe_buffer *bufs;
1924 struct fuse_copy_state cs;
cc080e9e 1925 struct fuse_dev *fud;
dd3bb14f
MS
1926 size_t rem;
1927 ssize_t ret;
1928
cc080e9e
MS
1929 fud = fuse_get_dev(out);
1930 if (!fud)
dd3bb14f
MS
1931 return -EPERM;
1932
07e77dca 1933 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
dd3bb14f
MS
1934 if (!bufs)
1935 return -ENOMEM;
1936
1937 pipe_lock(pipe);
1938 nbuf = 0;
1939 rem = 0;
1940 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
1941 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
1942
1943 ret = -EINVAL;
1944 if (rem < len) {
1945 pipe_unlock(pipe);
1946 goto out;
1947 }
1948
1949 rem = len;
1950 while (rem) {
1951 struct pipe_buffer *ibuf;
1952 struct pipe_buffer *obuf;
1953
1954 BUG_ON(nbuf >= pipe->buffers);
1955 BUG_ON(!pipe->nrbufs);
1956 ibuf = &pipe->bufs[pipe->curbuf];
1957 obuf = &bufs[nbuf];
1958
1959 if (rem >= ibuf->len) {
1960 *obuf = *ibuf;
1961 ibuf->ops = NULL;
1962 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
1963 pipe->nrbufs--;
1964 } else {
7bf2d1df 1965 pipe_buf_get(pipe, ibuf);
dd3bb14f
MS
1966 *obuf = *ibuf;
1967 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
1968 obuf->len = rem;
1969 ibuf->offset += obuf->len;
1970 ibuf->len -= obuf->len;
1971 }
1972 nbuf++;
1973 rem -= obuf->len;
1974 }
1975 pipe_unlock(pipe);
1976
dc00809a 1977 fuse_copy_init(&cs, 0, NULL);
dd3bb14f 1978 cs.pipebufs = bufs;
6c09e94a 1979 cs.nr_segs = nbuf;
dd3bb14f
MS
1980 cs.pipe = pipe;
1981
ce534fb0
MS
1982 if (flags & SPLICE_F_MOVE)
1983 cs.move_pages = 1;
1984
c3696046 1985 ret = fuse_dev_do_write(fud, &cs, len);
dd3bb14f 1986
a779638c
MS
1987 for (idx = 0; idx < nbuf; idx++)
1988 pipe_buf_release(pipe, &bufs[idx]);
1989
dd3bb14f
MS
1990out:
1991 kfree(bufs);
1992 return ret;
1993}
1994
334f485d
MS
1995static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
1996{
334f485d 1997 unsigned mask = POLLOUT | POLLWRNORM;
f88996a9 1998 struct fuse_iqueue *fiq;
cc080e9e
MS
1999 struct fuse_dev *fud = fuse_get_dev(file);
2000
2001 if (!fud)
7025d9ad 2002 return POLLERR;
334f485d 2003
cc080e9e 2004 fiq = &fud->fc->iq;
f88996a9 2005 poll_wait(file, &fiq->waitq, wait);
334f485d 2006
4ce60812 2007 spin_lock(&fiq->waitq.lock);
e16714d8 2008 if (!fiq->connected)
7025d9ad 2009 mask = POLLERR;
f88996a9 2010 else if (request_pending(fiq))
7025d9ad 2011 mask |= POLLIN | POLLRDNORM;
4ce60812 2012 spin_unlock(&fiq->waitq.lock);
334f485d
MS
2013
2014 return mask;
2015}
2016
69a53bf2
MS
2017/*
2018 * Abort all requests on the given list (pending or processing)
2019 *
d7133114 2020 * This function releases and reacquires fc->lock
69a53bf2 2021 */
334f485d
MS
2022static void end_requests(struct fuse_conn *fc, struct list_head *head)
2023{
2024 while (!list_empty(head)) {
2025 struct fuse_req *req;
2026 req = list_entry(head->next, struct fuse_req, list);
334f485d 2027 req->out.h.error = -ECONNABORTED;
33e14b4d
MS
2028 clear_bit(FR_PENDING, &req->flags);
2029 clear_bit(FR_SENT, &req->flags);
f377cb79 2030 list_del_init(&req->list);
334f485d 2031 request_end(fc, req);
334f485d
MS
2032 }
2033}
2034
357ccf2b
BG
2035static void end_polls(struct fuse_conn *fc)
2036{
2037 struct rb_node *p;
2038
2039 p = rb_first(&fc->polled_files);
2040
2041 while (p) {
2042 struct fuse_file *ff;
2043 ff = rb_entry(p, struct fuse_file, polled_node);
2044 wake_up_interruptible_all(&ff->poll_wait);
2045
2046 p = rb_next(p);
2047 }
2048}
2049
69a53bf2
MS
2050/*
2051 * Abort all requests.
2052 *
b716d425
MS
2053 * Emergency exit in case of a malicious or accidental deadlock, or just a hung
2054 * filesystem.
2055 *
2056 * The same effect is usually achievable through killing the filesystem daemon
2057 * and all users of the filesystem. The exception is the combination of an
2058 * asynchronous request and the tricky deadlock (see
2059 * Documentation/filesystems/fuse.txt).
69a53bf2 2060 *
b716d425
MS
2061 * Aborting requests under I/O goes as follows: 1: Separate out unlocked
2062 * requests, they should be finished off immediately. Locked requests will be
2063 * finished after unlock; see unlock_request(). 2: Finish off the unlocked
2064 * requests. It is possible that some request will finish before we can. This
2065 * is OK, the request will in that case be removed from the list before we touch
2066 * it.
69a53bf2
MS
2067 */
2068void fuse_abort_conn(struct fuse_conn *fc)
2069{
f88996a9
MS
2070 struct fuse_iqueue *fiq = &fc->iq;
2071
d7133114 2072 spin_lock(&fc->lock);
69a53bf2 2073 if (fc->connected) {
c3696046 2074 struct fuse_dev *fud;
b716d425 2075 struct fuse_req *req, *next;
41f98274
MS
2076 LIST_HEAD(to_end1);
2077 LIST_HEAD(to_end2);
b716d425 2078
69a53bf2 2079 fc->connected = 0;
51eb01e7 2080 fc->blocked = 0;
9759bd51 2081 fuse_set_initialized(fc);
c3696046
MS
2082 list_for_each_entry(fud, &fc->devices, entry) {
2083 struct fuse_pqueue *fpq = &fud->pq;
2084
2085 spin_lock(&fpq->lock);
2086 fpq->connected = 0;
2087 list_for_each_entry_safe(req, next, &fpq->io, list) {
2088 req->out.h.error = -ECONNABORTED;
2089 spin_lock(&req->waitq.lock);
2090 set_bit(FR_ABORTED, &req->flags);
2091 if (!test_bit(FR_LOCKED, &req->flags)) {
2092 set_bit(FR_PRIVATE, &req->flags);
2093 list_move(&req->list, &to_end1);
2094 }
2095 spin_unlock(&req->waitq.lock);
77cd9d48 2096 }
c3696046
MS
2097 list_splice_init(&fpq->processing, &to_end2);
2098 spin_unlock(&fpq->lock);
b716d425 2099 }
41f98274
MS
2100 fc->max_background = UINT_MAX;
2101 flush_bg_queue(fc);
8c91189a 2102
4ce60812 2103 spin_lock(&fiq->waitq.lock);
8c91189a 2104 fiq->connected = 0;
f88996a9 2105 list_splice_init(&fiq->pending, &to_end2);
8c91189a
MS
2106 while (forget_pending(fiq))
2107 kfree(dequeue_forget(fiq, 1, NULL));
4ce60812
MS
2108 wake_up_all_locked(&fiq->waitq);
2109 spin_unlock(&fiq->waitq.lock);
8c91189a 2110 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
ee314a87
MS
2111 end_polls(fc);
2112 wake_up_all(&fc->blocked_waitq);
2113 spin_unlock(&fc->lock);
8c91189a 2114
41f98274
MS
2115 while (!list_empty(&to_end1)) {
2116 req = list_first_entry(&to_end1, struct fuse_req, list);
b716d425 2117 __fuse_get_request(req);
f377cb79 2118 list_del_init(&req->list);
b716d425 2119 request_end(fc, req);
b716d425 2120 }
41f98274 2121 end_requests(fc, &to_end2);
ee314a87
MS
2122 } else {
2123 spin_unlock(&fc->lock);
69a53bf2 2124 }
69a53bf2 2125}
08cbf542 2126EXPORT_SYMBOL_GPL(fuse_abort_conn);
69a53bf2 2127
08cbf542 2128int fuse_dev_release(struct inode *inode, struct file *file)
334f485d 2129{
cc080e9e
MS
2130 struct fuse_dev *fud = fuse_get_dev(file);
2131
2132 if (fud) {
2133 struct fuse_conn *fc = fud->fc;
c3696046
MS
2134 struct fuse_pqueue *fpq = &fud->pq;
2135
2136 WARN_ON(!list_empty(&fpq->io));
2137 end_requests(fc, &fpq->processing);
2138 /* Are we the last open device? */
2139 if (atomic_dec_and_test(&fc->dev_count)) {
2140 WARN_ON(fc->iq.fasync != NULL);
2141 fuse_abort_conn(fc);
2142 }
cc080e9e 2143 fuse_dev_free(fud);
385a17bf 2144 }
334f485d
MS
2145 return 0;
2146}
08cbf542 2147EXPORT_SYMBOL_GPL(fuse_dev_release);
334f485d 2148
385a17bf
JD
2149static int fuse_dev_fasync(int fd, struct file *file, int on)
2150{
cc080e9e
MS
2151 struct fuse_dev *fud = fuse_get_dev(file);
2152
2153 if (!fud)
a87046d8 2154 return -EPERM;
385a17bf
JD
2155
2156 /* No locking - fasync_helper does its own locking */
cc080e9e 2157 return fasync_helper(fd, file, on, &fud->fc->iq.fasync);
385a17bf
JD
2158}
2159
00c570f4
MS
2160static int fuse_device_clone(struct fuse_conn *fc, struct file *new)
2161{
cc080e9e
MS
2162 struct fuse_dev *fud;
2163
00c570f4
MS
2164 if (new->private_data)
2165 return -EINVAL;
2166
cc080e9e
MS
2167 fud = fuse_dev_alloc(fc);
2168 if (!fud)
2169 return -ENOMEM;
2170
2171 new->private_data = fud;
c3696046 2172 atomic_inc(&fc->dev_count);
00c570f4
MS
2173
2174 return 0;
2175}
2176
2177static long fuse_dev_ioctl(struct file *file, unsigned int cmd,
2178 unsigned long arg)
2179{
2180 int err = -ENOTTY;
2181
2182 if (cmd == FUSE_DEV_IOC_CLONE) {
2183 int oldfd;
2184
2185 err = -EFAULT;
2186 if (!get_user(oldfd, (__u32 __user *) arg)) {
2187 struct file *old = fget(oldfd);
2188
2189 err = -EINVAL;
2190 if (old) {
8ed1f0e2
JH
2191 struct fuse_dev *fud = NULL;
2192
2193 /*
2194 * Check against file->f_op because CUSE
2195 * uses the same ioctl handler.
2196 */
2197 if (old->f_op == file->f_op &&
2198 old->f_cred->user_ns == file->f_cred->user_ns)
2199 fud = fuse_get_dev(old);
00c570f4 2200
cc080e9e 2201 if (fud) {
00c570f4 2202 mutex_lock(&fuse_mutex);
cc080e9e 2203 err = fuse_device_clone(fud->fc, file);
00c570f4
MS
2204 mutex_unlock(&fuse_mutex);
2205 }
2206 fput(old);
2207 }
2208 }
2209 }
2210 return err;
2211}
2212
4b6f5d20 2213const struct file_operations fuse_dev_operations = {
334f485d 2214 .owner = THIS_MODULE,
94e4fe2c 2215 .open = fuse_dev_open,
334f485d 2216 .llseek = no_llseek,
fbdbacca 2217 .read_iter = fuse_dev_read,
c3021629 2218 .splice_read = fuse_dev_splice_read,
fbdbacca 2219 .write_iter = fuse_dev_write,
dd3bb14f 2220 .splice_write = fuse_dev_splice_write,
334f485d
MS
2221 .poll = fuse_dev_poll,
2222 .release = fuse_dev_release,
385a17bf 2223 .fasync = fuse_dev_fasync,
00c570f4
MS
2224 .unlocked_ioctl = fuse_dev_ioctl,
2225 .compat_ioctl = fuse_dev_ioctl,
334f485d 2226};
08cbf542 2227EXPORT_SYMBOL_GPL(fuse_dev_operations);
334f485d
MS
2228
2229static struct miscdevice fuse_miscdevice = {
2230 .minor = FUSE_MINOR,
2231 .name = "fuse",
2232 .fops = &fuse_dev_operations,
2233};
2234
2235int __init fuse_dev_init(void)
2236{
2237 int err = -ENOMEM;
2238 fuse_req_cachep = kmem_cache_create("fuse_request",
2239 sizeof(struct fuse_req),
20c2df83 2240 0, 0, NULL);
334f485d
MS
2241 if (!fuse_req_cachep)
2242 goto out;
2243
2244 err = misc_register(&fuse_miscdevice);
2245 if (err)
2246 goto out_cache_clean;
2247
2248 return 0;
2249
2250 out_cache_clean:
2251 kmem_cache_destroy(fuse_req_cachep);
2252 out:
2253 return err;
2254}
2255
2256void fuse_dev_cleanup(void)
2257{
2258 misc_deregister(&fuse_miscdevice);
2259 kmem_cache_destroy(fuse_req_cachep);
2260}