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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
8bfc016d 28static struct fuse_conn *fuse_get_conn(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 */
34 return 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
8bfc016d 102static void block_sigs(sigset_t *oldset)
334f485d
MS
103{
104 sigset_t mask;
105
106 siginitsetinv(&mask, sigmask(SIGKILL));
107 sigprocmask(SIG_BLOCK, &mask, oldset);
108}
109
8bfc016d 110static void restore_sigs(sigset_t *oldset)
334f485d
MS
111{
112 sigprocmask(SIG_SETMASK, oldset, NULL);
113}
114
36cf66ed 115void __fuse_get_request(struct fuse_req *req)
334f485d
MS
116{
117 atomic_inc(&req->count);
118}
119
120/* Must be called with > 1 refcount */
121static void __fuse_put_request(struct fuse_req *req)
122{
123 BUG_ON(atomic_read(&req->count) < 2);
124 atomic_dec(&req->count);
125}
126
33649c91
MS
127static void fuse_req_init_context(struct fuse_req *req)
128{
499dcf20
EB
129 req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid());
130 req->in.h.gid = from_kgid_munged(&init_user_ns, current_fsgid());
33649c91
MS
131 req->in.h.pid = current->pid;
132}
133
9759bd51
MS
134void fuse_set_initialized(struct fuse_conn *fc)
135{
136 /* Make sure stores before this are seen on another CPU */
137 smp_wmb();
138 fc->initialized = 1;
139}
140
0aada884
MP
141static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
142{
143 return !fc->initialized || (for_background && fc->blocked);
144}
145
8b41e671
MP
146static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
147 bool for_background)
334f485d 148{
08a53cdc 149 struct fuse_req *req;
08a53cdc 150 int err;
9bc5ddda 151 atomic_inc(&fc->num_waiting);
0aada884
MP
152
153 if (fuse_block_alloc(fc, for_background)) {
154 sigset_t oldset;
155 int intr;
156
157 block_sigs(&oldset);
722d2bea 158 intr = wait_event_interruptible_exclusive(fc->blocked_waitq,
0aada884
MP
159 !fuse_block_alloc(fc, for_background));
160 restore_sigs(&oldset);
161 err = -EINTR;
162 if (intr)
163 goto out;
164 }
9759bd51
MS
165 /* Matches smp_wmb() in fuse_set_initialized() */
166 smp_rmb();
08a53cdc 167
51eb01e7
MS
168 err = -ENOTCONN;
169 if (!fc->connected)
170 goto out;
171
de155226
MS
172 err = -ECONNREFUSED;
173 if (fc->conn_error)
174 goto out;
175
b111c8c0 176 req = fuse_request_alloc(npages);
9bc5ddda 177 err = -ENOMEM;
722d2bea
MP
178 if (!req) {
179 if (for_background)
180 wake_up(&fc->blocked_waitq);
9bc5ddda 181 goto out;
722d2bea 182 }
334f485d 183
33649c91 184 fuse_req_init_context(req);
825d6d33
MS
185 __set_bit(FR_WAITING, &req->flags);
186 if (for_background)
187 __set_bit(FR_BACKGROUND, &req->flags);
188
334f485d 189 return req;
9bc5ddda
MS
190
191 out:
192 atomic_dec(&fc->num_waiting);
193 return ERR_PTR(err);
334f485d 194}
8b41e671
MP
195
196struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
197{
198 return __fuse_get_req(fc, npages, false);
199}
08cbf542 200EXPORT_SYMBOL_GPL(fuse_get_req);
334f485d 201
8b41e671
MP
202struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
203 unsigned npages)
204{
205 return __fuse_get_req(fc, npages, true);
206}
207EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
208
33649c91
MS
209/*
210 * Return request in fuse_file->reserved_req. However that may
211 * currently be in use. If that is the case, wait for it to become
212 * available.
213 */
214static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
215 struct file *file)
216{
217 struct fuse_req *req = NULL;
218 struct fuse_file *ff = file->private_data;
219
220 do {
de5e3dec 221 wait_event(fc->reserved_req_waitq, ff->reserved_req);
33649c91
MS
222 spin_lock(&fc->lock);
223 if (ff->reserved_req) {
224 req = ff->reserved_req;
225 ff->reserved_req = NULL;
cb0942b8 226 req->stolen_file = get_file(file);
33649c91
MS
227 }
228 spin_unlock(&fc->lock);
229 } while (!req);
230
231 return req;
232}
233
234/*
235 * Put stolen request back into fuse_file->reserved_req
236 */
237static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
238{
239 struct file *file = req->stolen_file;
240 struct fuse_file *ff = file->private_data;
241
242 spin_lock(&fc->lock);
b2430d75 243 fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
33649c91
MS
244 BUG_ON(ff->reserved_req);
245 ff->reserved_req = req;
de5e3dec 246 wake_up_all(&fc->reserved_req_waitq);
33649c91
MS
247 spin_unlock(&fc->lock);
248 fput(file);
249}
250
251/*
252 * Gets a requests for a file operation, always succeeds
253 *
254 * This is used for sending the FLUSH request, which must get to
255 * userspace, due to POSIX locks which may need to be unlocked.
256 *
257 * If allocation fails due to OOM, use the reserved request in
258 * fuse_file.
259 *
260 * This is very unlikely to deadlock accidentally, since the
261 * filesystem should not have it's own file open. If deadlock is
262 * intentional, it can still be broken by "aborting" the filesystem.
263 */
b111c8c0
MP
264struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
265 struct file *file)
33649c91
MS
266{
267 struct fuse_req *req;
268
269 atomic_inc(&fc->num_waiting);
0aada884 270 wait_event(fc->blocked_waitq, fc->initialized);
9759bd51
MS
271 /* Matches smp_wmb() in fuse_set_initialized() */
272 smp_rmb();
b111c8c0 273 req = fuse_request_alloc(0);
33649c91
MS
274 if (!req)
275 req = get_reserved_req(fc, file);
276
277 fuse_req_init_context(req);
825d6d33
MS
278 __set_bit(FR_WAITING, &req->flags);
279 __clear_bit(FR_BACKGROUND, &req->flags);
33649c91
MS
280 return req;
281}
282
334f485d 283void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
7128ec2a
MS
284{
285 if (atomic_dec_and_test(&req->count)) {
825d6d33 286 if (test_bit(FR_BACKGROUND, &req->flags)) {
722d2bea
MP
287 /*
288 * We get here in the unlikely case that a background
289 * request was allocated but not sent
290 */
291 spin_lock(&fc->lock);
292 if (!fc->blocked)
293 wake_up(&fc->blocked_waitq);
294 spin_unlock(&fc->lock);
295 }
296
825d6d33
MS
297 if (test_bit(FR_WAITING, &req->flags)) {
298 __clear_bit(FR_WAITING, &req->flags);
9bc5ddda 299 atomic_dec(&fc->num_waiting);
73e0e738 300 }
33649c91
MS
301
302 if (req->stolen_file)
303 put_reserved_req(fc, req);
304 else
305 fuse_request_free(req);
7128ec2a
MS
306 }
307}
08cbf542 308EXPORT_SYMBOL_GPL(fuse_put_request);
7128ec2a 309
d12def1b
MS
310static unsigned len_args(unsigned numargs, struct fuse_arg *args)
311{
312 unsigned nbytes = 0;
313 unsigned i;
314
315 for (i = 0; i < numargs; i++)
316 nbytes += args[i].size;
317
318 return nbytes;
319}
320
f88996a9 321static u64 fuse_get_unique(struct fuse_iqueue *fiq)
d12def1b 322{
f88996a9 323 return ++fiq->reqctr;
d12def1b
MS
324}
325
f88996a9 326static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
d12def1b 327{
d12def1b
MS
328 req->in.h.len = sizeof(struct fuse_in_header) +
329 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
f88996a9
MS
330 list_add_tail(&req->list, &fiq->pending);
331 wake_up(&fiq->waitq);
332 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
d12def1b
MS
333}
334
07e77dca
MS
335void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
336 u64 nodeid, u64 nlookup)
337{
f88996a9
MS
338 struct fuse_iqueue *fiq = &fc->iq;
339
02c048b9
MS
340 forget->forget_one.nodeid = nodeid;
341 forget->forget_one.nlookup = nlookup;
07e77dca
MS
342
343 spin_lock(&fc->lock);
e16714d8 344 if (fiq->connected) {
f88996a9
MS
345 fiq->forget_list_tail->next = forget;
346 fiq->forget_list_tail = forget;
347 wake_up(&fiq->waitq);
348 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
5dfcc87f
MS
349 } else {
350 kfree(forget);
351 }
07e77dca
MS
352 spin_unlock(&fc->lock);
353}
354
d12def1b
MS
355static void flush_bg_queue(struct fuse_conn *fc)
356{
7a6d3c8b 357 while (fc->active_background < fc->max_background &&
d12def1b
MS
358 !list_empty(&fc->bg_queue)) {
359 struct fuse_req *req;
f88996a9 360 struct fuse_iqueue *fiq = &fc->iq;
d12def1b
MS
361
362 req = list_entry(fc->bg_queue.next, struct fuse_req, list);
363 list_del(&req->list);
364 fc->active_background++;
f88996a9
MS
365 req->in.h.unique = fuse_get_unique(fiq);
366 queue_request(fiq, req);
d12def1b
MS
367 }
368}
369
334f485d
MS
370/*
371 * This function is called when a request is finished. Either a reply
f9a2842e 372 * has arrived or it was aborted (and not yet sent) or some error
f43b155a 373 * occurred during communication with userspace, or the device file
51eb01e7
MS
374 * was closed. The requester thread is woken up (if still waiting),
375 * the 'end' callback is called if given, else the reference to the
376 * request is released
7128ec2a 377 *
d7133114 378 * Called with fc->lock, unlocks it
334f485d
MS
379 */
380static void request_end(struct fuse_conn *fc, struct fuse_req *req)
b9ca67b2 381__releases(fc->lock)
334f485d 382{
51eb01e7
MS
383 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
384 req->end = NULL;
0d8e84b0
MS
385 list_del_init(&req->list);
386 list_del_init(&req->intr_entry);
33e14b4d
MS
387 WARN_ON(test_bit(FR_PENDING, &req->flags));
388 WARN_ON(test_bit(FR_SENT, &req->flags));
c4775267 389 smp_wmb();
33e14b4d 390 set_bit(FR_FINISHED, &req->flags);
825d6d33
MS
391 if (test_bit(FR_BACKGROUND, &req->flags)) {
392 clear_bit(FR_BACKGROUND, &req->flags);
722d2bea 393 if (fc->num_background == fc->max_background)
51eb01e7 394 fc->blocked = 0;
722d2bea
MP
395
396 /* Wake up next waiter, if any */
3c18ef81 397 if (!fc->blocked && waitqueue_active(&fc->blocked_waitq))
722d2bea
MP
398 wake_up(&fc->blocked_waitq);
399
7a6d3c8b 400 if (fc->num_background == fc->congestion_threshold &&
a325f9b9 401 fc->connected && fc->bdi_initialized) {
8aa7e847
JA
402 clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
403 clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
f92b99b9 404 }
51eb01e7 405 fc->num_background--;
d12def1b
MS
406 fc->active_background--;
407 flush_bg_queue(fc);
334f485d 408 }
51eb01e7 409 spin_unlock(&fc->lock);
51eb01e7
MS
410 wake_up(&req->waitq);
411 if (end)
412 end(fc, req);
e9bb09dd 413 fuse_put_request(fc, req);
334f485d
MS
414}
415
f88996a9 416static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
a4d27e75 417{
f88996a9
MS
418 list_add_tail(&req->intr_entry, &fiq->interrupts);
419 wake_up(&fiq->waitq);
420 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
a4d27e75
MS
421}
422
7c352bdf 423static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
334f485d 424{
c4775267
MS
425 int err;
426
a4d27e75
MS
427 if (!fc->no_interrupt) {
428 /* Any signal may interrupt this */
c4775267 429 err = wait_event_interruptible(req->waitq,
33e14b4d 430 test_bit(FR_FINISHED, &req->flags));
c4775267 431 if (!err)
a4d27e75
MS
432 return;
433
c4775267 434 spin_lock(&fc->lock);
825d6d33 435 set_bit(FR_INTERRUPTED, &req->flags);
33e14b4d 436 if (test_bit(FR_SENT, &req->flags))
f88996a9 437 queue_interrupt(&fc->iq, req);
c4775267 438 spin_unlock(&fc->lock);
a4d27e75
MS
439 }
440
825d6d33 441 if (!test_bit(FR_FORCE, &req->flags)) {
a4d27e75
MS
442 sigset_t oldset;
443
444 /* Only fatal signals may interrupt this */
51eb01e7 445 block_sigs(&oldset);
c4775267 446 err = wait_event_interruptible(req->waitq,
33e14b4d 447 test_bit(FR_FINISHED, &req->flags));
51eb01e7 448 restore_sigs(&oldset);
a131de0a 449
c4775267 450 if (!err)
a131de0a
MS
451 return;
452
c4775267 453 spin_lock(&fc->lock);
a131de0a 454 /* Request is not yet in userspace, bail out */
33e14b4d 455 if (test_bit(FR_PENDING, &req->flags)) {
a131de0a 456 list_del(&req->list);
c4775267 457 spin_unlock(&fc->lock);
a131de0a
MS
458 __fuse_put_request(req);
459 req->out.h.error = -EINTR;
460 return;
461 }
c4775267 462 spin_unlock(&fc->lock);
51eb01e7 463 }
334f485d 464
a131de0a
MS
465 /*
466 * Either request is already in userspace, or it was forced.
467 * Wait it out.
468 */
33e14b4d 469 wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
334f485d
MS
470}
471
6a4e922c 472static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
334f485d 473{
e16714d8
MS
474 struct fuse_iqueue *fiq = &fc->iq;
475
825d6d33 476 BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
d7133114 477 spin_lock(&fc->lock);
e16714d8 478 if (!fiq->connected) {
c4775267 479 spin_unlock(&fc->lock);
334f485d 480 req->out.h.error = -ENOTCONN;
c4775267 481 } else {
f88996a9
MS
482 req->in.h.unique = fuse_get_unique(fiq);
483 queue_request(fiq, req);
334f485d
MS
484 /* acquire extra reference, since request is still needed
485 after request_end() */
486 __fuse_get_request(req);
c4775267 487 spin_unlock(&fc->lock);
334f485d 488
7c352bdf 489 request_wait_answer(fc, req);
c4775267
MS
490 /* Pairs with smp_wmb() in request_end() */
491 smp_rmb();
334f485d 492 }
334f485d 493}
6a4e922c
EW
494
495void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
496{
825d6d33
MS
497 __set_bit(FR_ISREPLY, &req->flags);
498 if (!test_bit(FR_WAITING, &req->flags)) {
499 __set_bit(FR_WAITING, &req->flags);
5437f241
MS
500 atomic_inc(&fc->num_waiting);
501 }
6a4e922c
EW
502 __fuse_request_send(fc, req);
503}
08cbf542 504EXPORT_SYMBOL_GPL(fuse_request_send);
334f485d 505
21f62174
MS
506static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
507{
508 if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS)
509 args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE;
510
511 if (fc->minor < 9) {
512 switch (args->in.h.opcode) {
513 case FUSE_LOOKUP:
514 case FUSE_CREATE:
515 case FUSE_MKNOD:
516 case FUSE_MKDIR:
517 case FUSE_SYMLINK:
518 case FUSE_LINK:
519 args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
520 break;
521 case FUSE_GETATTR:
522 case FUSE_SETATTR:
523 args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
524 break;
525 }
526 }
527 if (fc->minor < 12) {
528 switch (args->in.h.opcode) {
529 case FUSE_CREATE:
530 args->in.args[0].size = sizeof(struct fuse_open_in);
531 break;
532 case FUSE_MKNOD:
533 args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
534 break;
535 }
536 }
537}
538
7078187a
MS
539ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
540{
541 struct fuse_req *req;
542 ssize_t ret;
543
544 req = fuse_get_req(fc, 0);
545 if (IS_ERR(req))
546 return PTR_ERR(req);
547
21f62174
MS
548 /* Needs to be done after fuse_get_req() so that fc->minor is valid */
549 fuse_adjust_compat(fc, args);
550
7078187a
MS
551 req->in.h.opcode = args->in.h.opcode;
552 req->in.h.nodeid = args->in.h.nodeid;
553 req->in.numargs = args->in.numargs;
554 memcpy(req->in.args, args->in.args,
555 args->in.numargs * sizeof(struct fuse_in_arg));
556 req->out.argvar = args->out.argvar;
557 req->out.numargs = args->out.numargs;
558 memcpy(req->out.args, args->out.args,
559 args->out.numargs * sizeof(struct fuse_arg));
560 fuse_request_send(fc, req);
561 ret = req->out.h.error;
562 if (!ret && args->out.argvar) {
563 BUG_ON(args->out.numargs != 1);
564 ret = req->out.args[0].size;
565 }
566 fuse_put_request(fc, req);
567
568 return ret;
569}
570
f0139aa8
MS
571/*
572 * Called under fc->lock
573 *
574 * fc->connected must have been checked previously
575 */
576void fuse_request_send_background_locked(struct fuse_conn *fc,
577 struct fuse_req *req)
d12def1b 578{
825d6d33
MS
579 BUG_ON(!test_bit(FR_BACKGROUND, &req->flags));
580 if (!test_bit(FR_WAITING, &req->flags)) {
581 __set_bit(FR_WAITING, &req->flags);
5437f241
MS
582 atomic_inc(&fc->num_waiting);
583 }
825d6d33 584 __set_bit(FR_ISREPLY, &req->flags);
d12def1b 585 fc->num_background++;
7a6d3c8b 586 if (fc->num_background == fc->max_background)
d12def1b 587 fc->blocked = 1;
7a6d3c8b 588 if (fc->num_background == fc->congestion_threshold &&
a325f9b9 589 fc->bdi_initialized) {
8aa7e847
JA
590 set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
591 set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
d12def1b
MS
592 }
593 list_add_tail(&req->list, &fc->bg_queue);
594 flush_bg_queue(fc);
595}
596
f0139aa8 597void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
334f485d 598{
42dc6211 599 BUG_ON(!req->end);
d7133114 600 spin_lock(&fc->lock);
1e9a4ed9 601 if (fc->connected) {
f0139aa8 602 fuse_request_send_background_locked(fc, req);
d7133114 603 spin_unlock(&fc->lock);
334f485d 604 } else {
42dc6211 605 spin_unlock(&fc->lock);
334f485d 606 req->out.h.error = -ENOTCONN;
42dc6211
MS
607 req->end(fc, req);
608 fuse_put_request(fc, req);
334f485d
MS
609 }
610}
08cbf542 611EXPORT_SYMBOL_GPL(fuse_request_send_background);
334f485d 612
2d45ba38
MS
613static int fuse_request_send_notify_reply(struct fuse_conn *fc,
614 struct fuse_req *req, u64 unique)
615{
616 int err = -ENODEV;
f88996a9 617 struct fuse_iqueue *fiq = &fc->iq;
2d45ba38 618
825d6d33 619 __clear_bit(FR_ISREPLY, &req->flags);
2d45ba38
MS
620 req->in.h.unique = unique;
621 spin_lock(&fc->lock);
e16714d8 622 if (fiq->connected) {
f88996a9 623 queue_request(fiq, req);
2d45ba38
MS
624 err = 0;
625 }
626 spin_unlock(&fc->lock);
627
628 return err;
629}
630
0b05b183
AA
631void fuse_force_forget(struct file *file, u64 nodeid)
632{
6131ffaa 633 struct inode *inode = file_inode(file);
0b05b183
AA
634 struct fuse_conn *fc = get_fuse_conn(inode);
635 struct fuse_req *req;
636 struct fuse_forget_in inarg;
637
638 memset(&inarg, 0, sizeof(inarg));
639 inarg.nlookup = 1;
b111c8c0 640 req = fuse_get_req_nofail_nopages(fc, file);
0b05b183
AA
641 req->in.h.opcode = FUSE_FORGET;
642 req->in.h.nodeid = nodeid;
643 req->in.numargs = 1;
644 req->in.args[0].size = sizeof(inarg);
645 req->in.args[0].value = &inarg;
825d6d33 646 __clear_bit(FR_ISREPLY, &req->flags);
6a4e922c
EW
647 __fuse_request_send(fc, req);
648 /* ignore errors */
649 fuse_put_request(fc, req);
0b05b183
AA
650}
651
334f485d
MS
652/*
653 * Lock the request. Up to the next unlock_request() there mustn't be
654 * anything that could cause a page-fault. If the request was already
f9a2842e 655 * aborted bail out.
334f485d 656 */
dc00809a 657static int lock_request(struct fuse_req *req)
334f485d
MS
658{
659 int err = 0;
660 if (req) {
dc00809a 661 spin_lock(&req->waitq.lock);
825d6d33 662 if (test_bit(FR_ABORTED, &req->flags))
334f485d
MS
663 err = -ENOENT;
664 else
825d6d33 665 set_bit(FR_LOCKED, &req->flags);
dc00809a 666 spin_unlock(&req->waitq.lock);
334f485d
MS
667 }
668 return err;
669}
670
671/*
0d8e84b0
MS
672 * Unlock request. If it was aborted while locked, caller is responsible
673 * for unlocking and ending the request.
334f485d 674 */
dc00809a 675static int unlock_request(struct fuse_req *req)
334f485d 676{
0d8e84b0 677 int err = 0;
334f485d 678 if (req) {
dc00809a 679 spin_lock(&req->waitq.lock);
825d6d33 680 if (test_bit(FR_ABORTED, &req->flags))
0d8e84b0
MS
681 err = -ENOENT;
682 else
825d6d33 683 clear_bit(FR_LOCKED, &req->flags);
dc00809a 684 spin_unlock(&req->waitq.lock);
334f485d 685 }
0d8e84b0 686 return err;
334f485d
MS
687}
688
689struct fuse_copy_state {
690 int write;
691 struct fuse_req *req;
6c09e94a 692 struct iov_iter *iter;
dd3bb14f
MS
693 struct pipe_buffer *pipebufs;
694 struct pipe_buffer *currbuf;
695 struct pipe_inode_info *pipe;
334f485d 696 unsigned long nr_segs;
334f485d 697 struct page *pg;
334f485d 698 unsigned len;
c55a01d3 699 unsigned offset;
ce534fb0 700 unsigned move_pages:1;
334f485d
MS
701};
702
dc00809a 703static void fuse_copy_init(struct fuse_copy_state *cs, int write,
6c09e94a 704 struct iov_iter *iter)
334f485d
MS
705{
706 memset(cs, 0, sizeof(*cs));
707 cs->write = write;
6c09e94a 708 cs->iter = iter;
334f485d
MS
709}
710
711/* Unmap and put previous page of userspace buffer */
8bfc016d 712static void fuse_copy_finish(struct fuse_copy_state *cs)
334f485d 713{
dd3bb14f
MS
714 if (cs->currbuf) {
715 struct pipe_buffer *buf = cs->currbuf;
716
c55a01d3 717 if (cs->write)
c3021629 718 buf->len = PAGE_SIZE - cs->len;
dd3bb14f 719 cs->currbuf = NULL;
c55a01d3 720 } else if (cs->pg) {
334f485d
MS
721 if (cs->write) {
722 flush_dcache_page(cs->pg);
723 set_page_dirty_lock(cs->pg);
724 }
725 put_page(cs->pg);
334f485d 726 }
c55a01d3 727 cs->pg = NULL;
334f485d
MS
728}
729
730/*
731 * Get another pagefull of userspace buffer, and map it to kernel
732 * address space, and lock request
733 */
734static int fuse_copy_fill(struct fuse_copy_state *cs)
735{
c55a01d3 736 struct page *page;
334f485d
MS
737 int err;
738
dc00809a 739 err = unlock_request(cs->req);
0d8e84b0
MS
740 if (err)
741 return err;
742
334f485d 743 fuse_copy_finish(cs);
dd3bb14f
MS
744 if (cs->pipebufs) {
745 struct pipe_buffer *buf = cs->pipebufs;
746
c3021629
MS
747 if (!cs->write) {
748 err = buf->ops->confirm(cs->pipe, buf);
749 if (err)
750 return err;
751
752 BUG_ON(!cs->nr_segs);
753 cs->currbuf = buf;
c55a01d3
MS
754 cs->pg = buf->page;
755 cs->offset = buf->offset;
c3021629 756 cs->len = buf->len;
c3021629
MS
757 cs->pipebufs++;
758 cs->nr_segs--;
759 } else {
c3021629
MS
760 if (cs->nr_segs == cs->pipe->buffers)
761 return -EIO;
762
763 page = alloc_page(GFP_HIGHUSER);
764 if (!page)
765 return -ENOMEM;
766
767 buf->page = page;
768 buf->offset = 0;
769 buf->len = 0;
770
771 cs->currbuf = buf;
c55a01d3
MS
772 cs->pg = page;
773 cs->offset = 0;
c3021629
MS
774 cs->len = PAGE_SIZE;
775 cs->pipebufs++;
776 cs->nr_segs++;
777 }
dd3bb14f 778 } else {
6c09e94a
AV
779 size_t off;
780 err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off);
dd3bb14f
MS
781 if (err < 0)
782 return err;
6c09e94a
AV
783 BUG_ON(!err);
784 cs->len = err;
785 cs->offset = off;
c55a01d3 786 cs->pg = page;
6c09e94a
AV
787 cs->offset = off;
788 iov_iter_advance(cs->iter, err);
334f485d 789 }
334f485d 790
dc00809a 791 return lock_request(cs->req);
334f485d
MS
792}
793
794/* Do as much copy to/from userspace buffer as we can */
8bfc016d 795static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
334f485d
MS
796{
797 unsigned ncpy = min(*size, cs->len);
798 if (val) {
c55a01d3
MS
799 void *pgaddr = kmap_atomic(cs->pg);
800 void *buf = pgaddr + cs->offset;
801
334f485d 802 if (cs->write)
c55a01d3 803 memcpy(buf, *val, ncpy);
334f485d 804 else
c55a01d3
MS
805 memcpy(*val, buf, ncpy);
806
807 kunmap_atomic(pgaddr);
334f485d
MS
808 *val += ncpy;
809 }
810 *size -= ncpy;
811 cs->len -= ncpy;
c55a01d3 812 cs->offset += ncpy;
334f485d
MS
813 return ncpy;
814}
815
ce534fb0
MS
816static int fuse_check_page(struct page *page)
817{
818 if (page_mapcount(page) ||
819 page->mapping != NULL ||
820 page_count(page) != 1 ||
821 (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
822 ~(1 << PG_locked |
823 1 << PG_referenced |
824 1 << PG_uptodate |
825 1 << PG_lru |
826 1 << PG_active |
827 1 << PG_reclaim))) {
828 printk(KERN_WARNING "fuse: trying to steal weird page\n");
829 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);
830 return 1;
831 }
832 return 0;
833}
834
835static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
836{
837 int err;
838 struct page *oldpage = *pagep;
839 struct page *newpage;
840 struct pipe_buffer *buf = cs->pipebufs;
ce534fb0 841
dc00809a 842 err = unlock_request(cs->req);
0d8e84b0
MS
843 if (err)
844 return err;
845
ce534fb0
MS
846 fuse_copy_finish(cs);
847
848 err = buf->ops->confirm(cs->pipe, buf);
849 if (err)
850 return err;
851
852 BUG_ON(!cs->nr_segs);
853 cs->currbuf = buf;
854 cs->len = buf->len;
855 cs->pipebufs++;
856 cs->nr_segs--;
857
858 if (cs->len != PAGE_SIZE)
859 goto out_fallback;
860
861 if (buf->ops->steal(cs->pipe, buf) != 0)
862 goto out_fallback;
863
864 newpage = buf->page;
865
aa991b3b
MS
866 if (!PageUptodate(newpage))
867 SetPageUptodate(newpage);
ce534fb0
MS
868
869 ClearPageMappedToDisk(newpage);
870
871 if (fuse_check_page(newpage) != 0)
872 goto out_fallback_unlock;
873
ce534fb0
MS
874 /*
875 * This is a new and locked page, it shouldn't be mapped or
876 * have any special flags on it
877 */
878 if (WARN_ON(page_mapped(oldpage)))
879 goto out_fallback_unlock;
880 if (WARN_ON(page_has_private(oldpage)))
881 goto out_fallback_unlock;
882 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
883 goto out_fallback_unlock;
884 if (WARN_ON(PageMlocked(oldpage)))
885 goto out_fallback_unlock;
886
ef6a3c63 887 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
ce534fb0 888 if (err) {
ef6a3c63
MS
889 unlock_page(newpage);
890 return err;
ce534fb0 891 }
ef6a3c63 892
ce534fb0
MS
893 page_cache_get(newpage);
894
895 if (!(buf->flags & PIPE_BUF_FLAG_LRU))
896 lru_cache_add_file(newpage);
897
898 err = 0;
dc00809a 899 spin_lock(&cs->req->waitq.lock);
825d6d33 900 if (test_bit(FR_ABORTED, &cs->req->flags))
ce534fb0
MS
901 err = -ENOENT;
902 else
903 *pagep = newpage;
dc00809a 904 spin_unlock(&cs->req->waitq.lock);
ce534fb0
MS
905
906 if (err) {
907 unlock_page(newpage);
908 page_cache_release(newpage);
909 return err;
910 }
911
912 unlock_page(oldpage);
913 page_cache_release(oldpage);
914 cs->len = 0;
915
916 return 0;
917
918out_fallback_unlock:
919 unlock_page(newpage);
920out_fallback:
c55a01d3
MS
921 cs->pg = buf->page;
922 cs->offset = buf->offset;
ce534fb0 923
dc00809a 924 err = lock_request(cs->req);
ce534fb0
MS
925 if (err)
926 return err;
927
928 return 1;
929}
930
c3021629
MS
931static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
932 unsigned offset, unsigned count)
933{
934 struct pipe_buffer *buf;
0d8e84b0 935 int err;
c3021629
MS
936
937 if (cs->nr_segs == cs->pipe->buffers)
938 return -EIO;
939
dc00809a 940 err = unlock_request(cs->req);
0d8e84b0
MS
941 if (err)
942 return err;
943
c3021629
MS
944 fuse_copy_finish(cs);
945
946 buf = cs->pipebufs;
947 page_cache_get(page);
948 buf->page = page;
949 buf->offset = offset;
950 buf->len = count;
951
952 cs->pipebufs++;
953 cs->nr_segs++;
954 cs->len = 0;
955
956 return 0;
957}
958
334f485d
MS
959/*
960 * Copy a page in the request to/from the userspace buffer. Must be
961 * done atomically
962 */
ce534fb0 963static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
8bfc016d 964 unsigned offset, unsigned count, int zeroing)
334f485d 965{
ce534fb0
MS
966 int err;
967 struct page *page = *pagep;
968
b6777c40
MS
969 if (page && zeroing && count < PAGE_SIZE)
970 clear_highpage(page);
971
334f485d 972 while (count) {
c3021629
MS
973 if (cs->write && cs->pipebufs && page) {
974 return fuse_ref_page(cs, page, offset, count);
975 } else if (!cs->len) {
ce534fb0
MS
976 if (cs->move_pages && page &&
977 offset == 0 && count == PAGE_SIZE) {
978 err = fuse_try_move_page(cs, pagep);
979 if (err <= 0)
980 return err;
981 } else {
982 err = fuse_copy_fill(cs);
983 if (err)
984 return err;
985 }
1729a16c 986 }
334f485d 987 if (page) {
2408f6ef 988 void *mapaddr = kmap_atomic(page);
334f485d
MS
989 void *buf = mapaddr + offset;
990 offset += fuse_copy_do(cs, &buf, &count);
2408f6ef 991 kunmap_atomic(mapaddr);
334f485d
MS
992 } else
993 offset += fuse_copy_do(cs, NULL, &count);
994 }
995 if (page && !cs->write)
996 flush_dcache_page(page);
997 return 0;
998}
999
1000/* Copy pages in the request to/from userspace buffer */
1001static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
1002 int zeroing)
1003{
1004 unsigned i;
1005 struct fuse_req *req = cs->req;
334f485d
MS
1006
1007 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
ce534fb0 1008 int err;
85f40aec
MP
1009 unsigned offset = req->page_descs[i].offset;
1010 unsigned count = min(nbytes, req->page_descs[i].length);
ce534fb0
MS
1011
1012 err = fuse_copy_page(cs, &req->pages[i], offset, count,
1013 zeroing);
334f485d
MS
1014 if (err)
1015 return err;
1016
1017 nbytes -= count;
334f485d
MS
1018 }
1019 return 0;
1020}
1021
1022/* Copy a single argument in the request to/from userspace buffer */
1023static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
1024{
1025 while (size) {
1729a16c
MS
1026 if (!cs->len) {
1027 int err = fuse_copy_fill(cs);
1028 if (err)
1029 return err;
1030 }
334f485d
MS
1031 fuse_copy_do(cs, &val, &size);
1032 }
1033 return 0;
1034}
1035
1036/* Copy request arguments to/from userspace buffer */
1037static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
1038 unsigned argpages, struct fuse_arg *args,
1039 int zeroing)
1040{
1041 int err = 0;
1042 unsigned i;
1043
1044 for (i = 0; !err && i < numargs; i++) {
1045 struct fuse_arg *arg = &args[i];
1046 if (i == numargs - 1 && argpages)
1047 err = fuse_copy_pages(cs, arg->size, zeroing);
1048 else
1049 err = fuse_copy_one(cs, arg->value, arg->size);
1050 }
1051 return err;
1052}
1053
f88996a9 1054static int forget_pending(struct fuse_iqueue *fiq)
07e77dca 1055{
f88996a9 1056 return fiq->forget_list_head.next != NULL;
07e77dca
MS
1057}
1058
f88996a9 1059static int request_pending(struct fuse_iqueue *fiq)
a4d27e75 1060{
f88996a9
MS
1061 return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) ||
1062 forget_pending(fiq);
a4d27e75
MS
1063}
1064
334f485d
MS
1065/* Wait until a request is available on the pending list */
1066static void request_wait(struct fuse_conn *fc)
b9ca67b2
MS
1067__releases(fc->lock)
1068__acquires(fc->lock)
334f485d 1069{
f88996a9 1070 struct fuse_iqueue *fiq = &fc->iq;
334f485d
MS
1071 DECLARE_WAITQUEUE(wait, current);
1072
f88996a9 1073 add_wait_queue_exclusive(&fiq->waitq, &wait);
e16714d8 1074 while (fiq->connected && !request_pending(fiq)) {
334f485d
MS
1075 set_current_state(TASK_INTERRUPTIBLE);
1076 if (signal_pending(current))
1077 break;
1078
d7133114 1079 spin_unlock(&fc->lock);
334f485d 1080 schedule();
d7133114 1081 spin_lock(&fc->lock);
334f485d
MS
1082 }
1083 set_current_state(TASK_RUNNING);
f88996a9 1084 remove_wait_queue(&fiq->waitq, &wait);
334f485d
MS
1085}
1086
a4d27e75
MS
1087/*
1088 * Transfer an interrupt request to userspace
1089 *
1090 * Unlike other requests this is assembled on demand, without a need
1091 * to allocate a separate fuse_req structure.
1092 *
1093 * Called with fc->lock held, releases it
1094 */
c3021629
MS
1095static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_copy_state *cs,
1096 size_t nbytes, struct fuse_req *req)
b9ca67b2 1097__releases(fc->lock)
a4d27e75 1098{
a4d27e75
MS
1099 struct fuse_in_header ih;
1100 struct fuse_interrupt_in arg;
1101 unsigned reqsize = sizeof(ih) + sizeof(arg);
1102 int err;
1103
1104 list_del_init(&req->intr_entry);
f88996a9 1105 req->intr_unique = fuse_get_unique(&fc->iq);
a4d27e75
MS
1106 memset(&ih, 0, sizeof(ih));
1107 memset(&arg, 0, sizeof(arg));
1108 ih.len = reqsize;
1109 ih.opcode = FUSE_INTERRUPT;
1110 ih.unique = req->intr_unique;
1111 arg.unique = req->in.h.unique;
1112
1113 spin_unlock(&fc->lock);
c3021629 1114 if (nbytes < reqsize)
a4d27e75
MS
1115 return -EINVAL;
1116
c3021629 1117 err = fuse_copy_one(cs, &ih, sizeof(ih));
a4d27e75 1118 if (!err)
c3021629
MS
1119 err = fuse_copy_one(cs, &arg, sizeof(arg));
1120 fuse_copy_finish(cs);
a4d27e75
MS
1121
1122 return err ? err : reqsize;
1123}
1124
f88996a9 1125static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
02c048b9
MS
1126 unsigned max,
1127 unsigned *countp)
07e77dca 1128{
f88996a9 1129 struct fuse_forget_link *head = fiq->forget_list_head.next;
02c048b9
MS
1130 struct fuse_forget_link **newhead = &head;
1131 unsigned count;
07e77dca 1132
02c048b9
MS
1133 for (count = 0; *newhead != NULL && count < max; count++)
1134 newhead = &(*newhead)->next;
1135
f88996a9 1136 fiq->forget_list_head.next = *newhead;
02c048b9 1137 *newhead = NULL;
f88996a9
MS
1138 if (fiq->forget_list_head.next == NULL)
1139 fiq->forget_list_tail = &fiq->forget_list_head;
07e77dca 1140
02c048b9
MS
1141 if (countp != NULL)
1142 *countp = count;
1143
1144 return head;
07e77dca
MS
1145}
1146
1147static int fuse_read_single_forget(struct fuse_conn *fc,
1148 struct fuse_copy_state *cs,
1149 size_t nbytes)
1150__releases(fc->lock)
1151{
1152 int err;
f88996a9
MS
1153 struct fuse_iqueue *fiq = &fc->iq;
1154 struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
07e77dca 1155 struct fuse_forget_in arg = {
02c048b9 1156 .nlookup = forget->forget_one.nlookup,
07e77dca
MS
1157 };
1158 struct fuse_in_header ih = {
1159 .opcode = FUSE_FORGET,
02c048b9 1160 .nodeid = forget->forget_one.nodeid,
f88996a9 1161 .unique = fuse_get_unique(fiq),
07e77dca
MS
1162 .len = sizeof(ih) + sizeof(arg),
1163 };
1164
1165 spin_unlock(&fc->lock);
1166 kfree(forget);
1167 if (nbytes < ih.len)
1168 return -EINVAL;
1169
1170 err = fuse_copy_one(cs, &ih, sizeof(ih));
1171 if (!err)
1172 err = fuse_copy_one(cs, &arg, sizeof(arg));
1173 fuse_copy_finish(cs);
1174
1175 if (err)
1176 return err;
1177
1178 return ih.len;
1179}
1180
02c048b9
MS
1181static int fuse_read_batch_forget(struct fuse_conn *fc,
1182 struct fuse_copy_state *cs, size_t nbytes)
1183__releases(fc->lock)
1184{
1185 int err;
1186 unsigned max_forgets;
1187 unsigned count;
1188 struct fuse_forget_link *head;
f88996a9 1189 struct fuse_iqueue *fiq = &fc->iq;
02c048b9
MS
1190 struct fuse_batch_forget_in arg = { .count = 0 };
1191 struct fuse_in_header ih = {
1192 .opcode = FUSE_BATCH_FORGET,
f88996a9 1193 .unique = fuse_get_unique(fiq),
02c048b9
MS
1194 .len = sizeof(ih) + sizeof(arg),
1195 };
1196
1197 if (nbytes < ih.len) {
1198 spin_unlock(&fc->lock);
1199 return -EINVAL;
1200 }
1201
1202 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
f88996a9 1203 head = dequeue_forget(fiq, max_forgets, &count);
02c048b9
MS
1204 spin_unlock(&fc->lock);
1205
1206 arg.count = count;
1207 ih.len += count * sizeof(struct fuse_forget_one);
1208 err = fuse_copy_one(cs, &ih, sizeof(ih));
1209 if (!err)
1210 err = fuse_copy_one(cs, &arg, sizeof(arg));
1211
1212 while (head) {
1213 struct fuse_forget_link *forget = head;
1214
1215 if (!err) {
1216 err = fuse_copy_one(cs, &forget->forget_one,
1217 sizeof(forget->forget_one));
1218 }
1219 head = forget->next;
1220 kfree(forget);
1221 }
1222
1223 fuse_copy_finish(cs);
1224
1225 if (err)
1226 return err;
1227
1228 return ih.len;
1229}
1230
1231static int fuse_read_forget(struct fuse_conn *fc, struct fuse_copy_state *cs,
1232 size_t nbytes)
1233__releases(fc->lock)
1234{
f88996a9
MS
1235 struct fuse_iqueue *fiq = &fc->iq;
1236
1237 if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
02c048b9
MS
1238 return fuse_read_single_forget(fc, cs, nbytes);
1239 else
1240 return fuse_read_batch_forget(fc, cs, nbytes);
1241}
1242
334f485d
MS
1243/*
1244 * Read a single request into the userspace filesystem's buffer. This
1245 * function waits until a request is available, then removes it from
1246 * the pending list and copies request data to userspace buffer. If
f9a2842e
MS
1247 * no reply is needed (FORGET) or request has been aborted or there
1248 * was an error during the copying then it's finished by calling
334f485d
MS
1249 * request_end(). Otherwise add it to the processing list, and set
1250 * the 'sent' flag.
1251 */
c3021629
MS
1252static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
1253 struct fuse_copy_state *cs, size_t nbytes)
334f485d
MS
1254{
1255 int err;
f88996a9 1256 struct fuse_iqueue *fiq = &fc->iq;
334f485d
MS
1257 struct fuse_req *req;
1258 struct fuse_in *in;
334f485d
MS
1259 unsigned reqsize;
1260
1d3d752b 1261 restart:
d7133114 1262 spin_lock(&fc->lock);
e5ac1d1e 1263 err = -EAGAIN;
e16714d8 1264 if ((file->f_flags & O_NONBLOCK) && fiq->connected &&
f88996a9 1265 !request_pending(fiq))
e5ac1d1e
JD
1266 goto err_unlock;
1267
334f485d
MS
1268 request_wait(fc);
1269 err = -ENODEV;
e16714d8 1270 if (!fiq->connected)
334f485d
MS
1271 goto err_unlock;
1272 err = -ERESTARTSYS;
f88996a9 1273 if (!request_pending(fiq))
334f485d
MS
1274 goto err_unlock;
1275
f88996a9
MS
1276 if (!list_empty(&fiq->interrupts)) {
1277 req = list_entry(fiq->interrupts.next, struct fuse_req,
a4d27e75 1278 intr_entry);
c3021629 1279 return fuse_read_interrupt(fc, cs, nbytes, req);
a4d27e75
MS
1280 }
1281
f88996a9
MS
1282 if (forget_pending(fiq)) {
1283 if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
02c048b9 1284 return fuse_read_forget(fc, cs, nbytes);
07e77dca 1285
f88996a9
MS
1286 if (fiq->forget_batch <= -8)
1287 fiq->forget_batch = 16;
07e77dca
MS
1288 }
1289
f88996a9 1290 req = list_entry(fiq->pending.next, struct fuse_req, list);
33e14b4d 1291 clear_bit(FR_PENDING, &req->flags);
d77a1d5b 1292 list_move(&req->list, &fc->io);
334f485d
MS
1293
1294 in = &req->in;
1d3d752b
MS
1295 reqsize = in->h.len;
1296 /* If request is too large, reply with an error and restart the read */
c3021629 1297 if (nbytes < reqsize) {
1d3d752b
MS
1298 req->out.h.error = -EIO;
1299 /* SETXATTR is special, since it may contain too large data */
1300 if (in->h.opcode == FUSE_SETXATTR)
1301 req->out.h.error = -E2BIG;
1302 request_end(fc, req);
1303 goto restart;
334f485d 1304 }
d7133114 1305 spin_unlock(&fc->lock);
c3021629
MS
1306 cs->req = req;
1307 err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1d3d752b 1308 if (!err)
c3021629 1309 err = fuse_copy_args(cs, in->numargs, in->argpages,
1d3d752b 1310 (struct fuse_arg *) in->args, 0);
c3021629 1311 fuse_copy_finish(cs);
d7133114 1312 spin_lock(&fc->lock);
825d6d33 1313 clear_bit(FR_LOCKED, &req->flags);
0d8e84b0 1314 if (!fc->connected) {
c9c9d7df
MS
1315 request_end(fc, req);
1316 return -ENODEV;
1317 }
334f485d 1318 if (err) {
c9c9d7df 1319 req->out.h.error = -EIO;
334f485d
MS
1320 request_end(fc, req);
1321 return err;
1322 }
825d6d33 1323 if (!test_bit(FR_ISREPLY, &req->flags)) {
334f485d 1324 request_end(fc, req);
825d6d33 1325 } else {
33e14b4d 1326 set_bit(FR_SENT, &req->flags);
d77a1d5b 1327 list_move_tail(&req->list, &fc->processing);
825d6d33 1328 if (test_bit(FR_INTERRUPTED, &req->flags))
f88996a9 1329 queue_interrupt(fiq, req);
d7133114 1330 spin_unlock(&fc->lock);
334f485d
MS
1331 }
1332 return reqsize;
1333
1334 err_unlock:
d7133114 1335 spin_unlock(&fc->lock);
334f485d
MS
1336 return err;
1337}
1338
94e4fe2c
TVB
1339static int fuse_dev_open(struct inode *inode, struct file *file)
1340{
1341 /*
1342 * The fuse device's file's private_data is used to hold
1343 * the fuse_conn(ection) when it is mounted, and is used to
1344 * keep track of whether the file has been mounted already.
1345 */
1346 file->private_data = NULL;
1347 return 0;
1348}
1349
fbdbacca 1350static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
c3021629
MS
1351{
1352 struct fuse_copy_state cs;
1353 struct file *file = iocb->ki_filp;
1354 struct fuse_conn *fc = fuse_get_conn(file);
1355 if (!fc)
1356 return -EPERM;
1357
fbdbacca
AV
1358 if (!iter_is_iovec(to))
1359 return -EINVAL;
1360
dc00809a 1361 fuse_copy_init(&cs, 1, to);
c3021629 1362
fbdbacca 1363 return fuse_dev_do_read(fc, file, &cs, iov_iter_count(to));
c3021629
MS
1364}
1365
c3021629
MS
1366static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1367 struct pipe_inode_info *pipe,
1368 size_t len, unsigned int flags)
1369{
1370 int ret;
1371 int page_nr = 0;
1372 int do_wakeup = 0;
1373 struct pipe_buffer *bufs;
1374 struct fuse_copy_state cs;
1375 struct fuse_conn *fc = fuse_get_conn(in);
1376 if (!fc)
1377 return -EPERM;
1378
07e77dca 1379 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
c3021629
MS
1380 if (!bufs)
1381 return -ENOMEM;
1382
dc00809a 1383 fuse_copy_init(&cs, 1, NULL);
c3021629
MS
1384 cs.pipebufs = bufs;
1385 cs.pipe = pipe;
1386 ret = fuse_dev_do_read(fc, in, &cs, len);
1387 if (ret < 0)
1388 goto out;
1389
1390 ret = 0;
1391 pipe_lock(pipe);
1392
1393 if (!pipe->readers) {
1394 send_sig(SIGPIPE, current, 0);
1395 if (!ret)
1396 ret = -EPIPE;
1397 goto out_unlock;
1398 }
1399
1400 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1401 ret = -EIO;
1402 goto out_unlock;
1403 }
1404
1405 while (page_nr < cs.nr_segs) {
1406 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
1407 struct pipe_buffer *buf = pipe->bufs + newbuf;
1408
1409 buf->page = bufs[page_nr].page;
1410 buf->offset = bufs[page_nr].offset;
1411 buf->len = bufs[page_nr].len;
28a625cb
MS
1412 /*
1413 * Need to be careful about this. Having buf->ops in module
1414 * code can Oops if the buffer persists after module unload.
1415 */
1416 buf->ops = &nosteal_pipe_buf_ops;
c3021629
MS
1417
1418 pipe->nrbufs++;
1419 page_nr++;
1420 ret += buf->len;
1421
6447a3cf 1422 if (pipe->files)
c3021629
MS
1423 do_wakeup = 1;
1424 }
1425
1426out_unlock:
1427 pipe_unlock(pipe);
1428
1429 if (do_wakeup) {
1430 smp_mb();
1431 if (waitqueue_active(&pipe->wait))
1432 wake_up_interruptible(&pipe->wait);
1433 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
1434 }
1435
1436out:
1437 for (; page_nr < cs.nr_segs; page_nr++)
1438 page_cache_release(bufs[page_nr].page);
1439
1440 kfree(bufs);
1441 return ret;
1442}
1443
95668a69
TH
1444static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1445 struct fuse_copy_state *cs)
1446{
1447 struct fuse_notify_poll_wakeup_out outarg;
f6d47a17 1448 int err = -EINVAL;
95668a69
TH
1449
1450 if (size != sizeof(outarg))
f6d47a17 1451 goto err;
95668a69
TH
1452
1453 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1454 if (err)
f6d47a17 1455 goto err;
95668a69 1456
f6d47a17 1457 fuse_copy_finish(cs);
95668a69 1458 return fuse_notify_poll_wakeup(fc, &outarg);
f6d47a17
MS
1459
1460err:
1461 fuse_copy_finish(cs);
1462 return err;
95668a69
TH
1463}
1464
3b463ae0
JM
1465static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1466 struct fuse_copy_state *cs)
1467{
1468 struct fuse_notify_inval_inode_out outarg;
1469 int err = -EINVAL;
1470
1471 if (size != sizeof(outarg))
1472 goto err;
1473
1474 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1475 if (err)
1476 goto err;
1477 fuse_copy_finish(cs);
1478
1479 down_read(&fc->killsb);
1480 err = -ENOENT;
b21dda43
MS
1481 if (fc->sb) {
1482 err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1483 outarg.off, outarg.len);
1484 }
3b463ae0
JM
1485 up_read(&fc->killsb);
1486 return err;
1487
1488err:
1489 fuse_copy_finish(cs);
1490 return err;
1491}
1492
1493static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1494 struct fuse_copy_state *cs)
1495{
1496 struct fuse_notify_inval_entry_out outarg;
b2d82ee3
FW
1497 int err = -ENOMEM;
1498 char *buf;
3b463ae0
JM
1499 struct qstr name;
1500
b2d82ee3
FW
1501 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1502 if (!buf)
1503 goto err;
1504
1505 err = -EINVAL;
3b463ae0
JM
1506 if (size < sizeof(outarg))
1507 goto err;
1508
1509 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1510 if (err)
1511 goto err;
1512
1513 err = -ENAMETOOLONG;
1514 if (outarg.namelen > FUSE_NAME_MAX)
1515 goto err;
1516
c2183d1e
MS
1517 err = -EINVAL;
1518 if (size != sizeof(outarg) + outarg.namelen + 1)
1519 goto err;
1520
3b463ae0
JM
1521 name.name = buf;
1522 name.len = outarg.namelen;
1523 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1524 if (err)
1525 goto err;
1526 fuse_copy_finish(cs);
1527 buf[outarg.namelen] = 0;
1528 name.hash = full_name_hash(name.name, name.len);
1529
1530 down_read(&fc->killsb);
1531 err = -ENOENT;
b21dda43 1532 if (fc->sb)
451d0f59
JM
1533 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1534 up_read(&fc->killsb);
1535 kfree(buf);
1536 return err;
1537
1538err:
1539 kfree(buf);
1540 fuse_copy_finish(cs);
1541 return err;
1542}
1543
1544static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1545 struct fuse_copy_state *cs)
1546{
1547 struct fuse_notify_delete_out outarg;
1548 int err = -ENOMEM;
1549 char *buf;
1550 struct qstr name;
1551
1552 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1553 if (!buf)
1554 goto err;
1555
1556 err = -EINVAL;
1557 if (size < sizeof(outarg))
1558 goto err;
1559
1560 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1561 if (err)
1562 goto err;
1563
1564 err = -ENAMETOOLONG;
1565 if (outarg.namelen > FUSE_NAME_MAX)
1566 goto err;
1567
1568 err = -EINVAL;
1569 if (size != sizeof(outarg) + outarg.namelen + 1)
1570 goto err;
1571
1572 name.name = buf;
1573 name.len = outarg.namelen;
1574 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1575 if (err)
1576 goto err;
1577 fuse_copy_finish(cs);
1578 buf[outarg.namelen] = 0;
1579 name.hash = full_name_hash(name.name, name.len);
1580
1581 down_read(&fc->killsb);
1582 err = -ENOENT;
1583 if (fc->sb)
1584 err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1585 outarg.child, &name);
3b463ae0 1586 up_read(&fc->killsb);
b2d82ee3 1587 kfree(buf);
3b463ae0
JM
1588 return err;
1589
1590err:
b2d82ee3 1591 kfree(buf);
3b463ae0
JM
1592 fuse_copy_finish(cs);
1593 return err;
1594}
1595
a1d75f25
MS
1596static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1597 struct fuse_copy_state *cs)
1598{
1599 struct fuse_notify_store_out outarg;
1600 struct inode *inode;
1601 struct address_space *mapping;
1602 u64 nodeid;
1603 int err;
1604 pgoff_t index;
1605 unsigned int offset;
1606 unsigned int num;
1607 loff_t file_size;
1608 loff_t end;
1609
1610 err = -EINVAL;
1611 if (size < sizeof(outarg))
1612 goto out_finish;
1613
1614 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1615 if (err)
1616 goto out_finish;
1617
1618 err = -EINVAL;
1619 if (size - sizeof(outarg) != outarg.size)
1620 goto out_finish;
1621
1622 nodeid = outarg.nodeid;
1623
1624 down_read(&fc->killsb);
1625
1626 err = -ENOENT;
1627 if (!fc->sb)
1628 goto out_up_killsb;
1629
1630 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1631 if (!inode)
1632 goto out_up_killsb;
1633
1634 mapping = inode->i_mapping;
1635 index = outarg.offset >> PAGE_CACHE_SHIFT;
1636 offset = outarg.offset & ~PAGE_CACHE_MASK;
1637 file_size = i_size_read(inode);
1638 end = outarg.offset + outarg.size;
1639 if (end > file_size) {
1640 file_size = end;
1641 fuse_write_update_size(inode, file_size);
1642 }
1643
1644 num = outarg.size;
1645 while (num) {
1646 struct page *page;
1647 unsigned int this_num;
1648
1649 err = -ENOMEM;
1650 page = find_or_create_page(mapping, index,
1651 mapping_gfp_mask(mapping));
1652 if (!page)
1653 goto out_iput;
1654
1655 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1656 err = fuse_copy_page(cs, &page, offset, this_num, 0);
063ec1e5
MS
1657 if (!err && offset == 0 &&
1658 (this_num == PAGE_CACHE_SIZE || file_size == end))
a1d75f25
MS
1659 SetPageUptodate(page);
1660 unlock_page(page);
1661 page_cache_release(page);
1662
1663 if (err)
1664 goto out_iput;
1665
1666 num -= this_num;
1667 offset = 0;
1668 index++;
1669 }
1670
1671 err = 0;
1672
1673out_iput:
1674 iput(inode);
1675out_up_killsb:
1676 up_read(&fc->killsb);
1677out_finish:
1678 fuse_copy_finish(cs);
1679 return err;
1680}
1681
2d45ba38
MS
1682static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
1683{
b745bc85 1684 release_pages(req->pages, req->num_pages, false);
2d45ba38
MS
1685}
1686
1687static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1688 struct fuse_notify_retrieve_out *outarg)
1689{
1690 int err;
1691 struct address_space *mapping = inode->i_mapping;
1692 struct fuse_req *req;
1693 pgoff_t index;
1694 loff_t file_size;
1695 unsigned int num;
1696 unsigned int offset;
0157443c 1697 size_t total_len = 0;
4d53dc99 1698 int num_pages;
2d45ba38 1699
4d53dc99
MP
1700 offset = outarg->offset & ~PAGE_CACHE_MASK;
1701 file_size = i_size_read(inode);
1702
1703 num = outarg->size;
1704 if (outarg->offset > file_size)
1705 num = 0;
1706 else if (outarg->offset + num > file_size)
1707 num = file_size - outarg->offset;
1708
1709 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1710 num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
1711
1712 req = fuse_get_req(fc, num_pages);
2d45ba38
MS
1713 if (IS_ERR(req))
1714 return PTR_ERR(req);
1715
2d45ba38
MS
1716 req->in.h.opcode = FUSE_NOTIFY_REPLY;
1717 req->in.h.nodeid = outarg->nodeid;
1718 req->in.numargs = 2;
1719 req->in.argpages = 1;
b2430d75 1720 req->page_descs[0].offset = offset;
2d45ba38
MS
1721 req->end = fuse_retrieve_end;
1722
1723 index = outarg->offset >> PAGE_CACHE_SHIFT;
2d45ba38 1724
4d53dc99 1725 while (num && req->num_pages < num_pages) {
2d45ba38
MS
1726 struct page *page;
1727 unsigned int this_num;
1728
1729 page = find_get_page(mapping, index);
1730 if (!page)
1731 break;
1732
1733 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1734 req->pages[req->num_pages] = page;
85f40aec 1735 req->page_descs[req->num_pages].length = this_num;
2d45ba38
MS
1736 req->num_pages++;
1737
c9e67d48 1738 offset = 0;
2d45ba38
MS
1739 num -= this_num;
1740 total_len += this_num;
48706d0a 1741 index++;
2d45ba38
MS
1742 }
1743 req->misc.retrieve_in.offset = outarg->offset;
1744 req->misc.retrieve_in.size = total_len;
1745 req->in.args[0].size = sizeof(req->misc.retrieve_in);
1746 req->in.args[0].value = &req->misc.retrieve_in;
1747 req->in.args[1].size = total_len;
1748
1749 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1750 if (err)
1751 fuse_retrieve_end(fc, req);
1752
1753 return err;
1754}
1755
1756static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1757 struct fuse_copy_state *cs)
1758{
1759 struct fuse_notify_retrieve_out outarg;
1760 struct inode *inode;
1761 int err;
1762
1763 err = -EINVAL;
1764 if (size != sizeof(outarg))
1765 goto copy_finish;
1766
1767 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1768 if (err)
1769 goto copy_finish;
1770
1771 fuse_copy_finish(cs);
1772
1773 down_read(&fc->killsb);
1774 err = -ENOENT;
1775 if (fc->sb) {
1776 u64 nodeid = outarg.nodeid;
1777
1778 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1779 if (inode) {
1780 err = fuse_retrieve(fc, inode, &outarg);
1781 iput(inode);
1782 }
1783 }
1784 up_read(&fc->killsb);
1785
1786 return err;
1787
1788copy_finish:
1789 fuse_copy_finish(cs);
1790 return err;
1791}
1792
8599396b
TH
1793static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1794 unsigned int size, struct fuse_copy_state *cs)
1795{
0d278362
MS
1796 /* Don't try to move pages (yet) */
1797 cs->move_pages = 0;
1798
8599396b 1799 switch (code) {
95668a69
TH
1800 case FUSE_NOTIFY_POLL:
1801 return fuse_notify_poll(fc, size, cs);
1802
3b463ae0
JM
1803 case FUSE_NOTIFY_INVAL_INODE:
1804 return fuse_notify_inval_inode(fc, size, cs);
1805
1806 case FUSE_NOTIFY_INVAL_ENTRY:
1807 return fuse_notify_inval_entry(fc, size, cs);
1808
a1d75f25
MS
1809 case FUSE_NOTIFY_STORE:
1810 return fuse_notify_store(fc, size, cs);
1811
2d45ba38
MS
1812 case FUSE_NOTIFY_RETRIEVE:
1813 return fuse_notify_retrieve(fc, size, cs);
1814
451d0f59
JM
1815 case FUSE_NOTIFY_DELETE:
1816 return fuse_notify_delete(fc, size, cs);
1817
8599396b 1818 default:
f6d47a17 1819 fuse_copy_finish(cs);
8599396b
TH
1820 return -EINVAL;
1821 }
1822}
1823
334f485d
MS
1824/* Look up request on processing list by unique ID */
1825static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
1826{
05726aca 1827 struct fuse_req *req;
334f485d 1828
05726aca 1829 list_for_each_entry(req, &fc->processing, list) {
a4d27e75 1830 if (req->in.h.unique == unique || req->intr_unique == unique)
334f485d
MS
1831 return req;
1832 }
1833 return NULL;
1834}
1835
1836static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1837 unsigned nbytes)
1838{
1839 unsigned reqsize = sizeof(struct fuse_out_header);
1840
1841 if (out->h.error)
1842 return nbytes != reqsize ? -EINVAL : 0;
1843
1844 reqsize += len_args(out->numargs, out->args);
1845
1846 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1847 return -EINVAL;
1848 else if (reqsize > nbytes) {
1849 struct fuse_arg *lastarg = &out->args[out->numargs-1];
1850 unsigned diffsize = reqsize - nbytes;
1851 if (diffsize > lastarg->size)
1852 return -EINVAL;
1853 lastarg->size -= diffsize;
1854 }
1855 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1856 out->page_zeroing);
1857}
1858
1859/*
1860 * Write a single reply to a request. First the header is copied from
1861 * the write buffer. The request is then searched on the processing
1862 * list by the unique ID found in the header. If found, then remove
1863 * it from the list and copy the rest of the buffer to the request.
1864 * The request is finished by calling request_end()
1865 */
dd3bb14f
MS
1866static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
1867 struct fuse_copy_state *cs, size_t nbytes)
334f485d
MS
1868{
1869 int err;
334f485d
MS
1870 struct fuse_req *req;
1871 struct fuse_out_header oh;
334f485d 1872
334f485d
MS
1873 if (nbytes < sizeof(struct fuse_out_header))
1874 return -EINVAL;
1875
dd3bb14f 1876 err = fuse_copy_one(cs, &oh, sizeof(oh));
334f485d
MS
1877 if (err)
1878 goto err_finish;
8599396b
TH
1879
1880 err = -EINVAL;
1881 if (oh.len != nbytes)
1882 goto err_finish;
1883
1884 /*
1885 * Zero oh.unique indicates unsolicited notification message
1886 * and error contains notification code.
1887 */
1888 if (!oh.unique) {
dd3bb14f 1889 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
8599396b
TH
1890 return err ? err : nbytes;
1891 }
1892
334f485d 1893 err = -EINVAL;
8599396b 1894 if (oh.error <= -1000 || oh.error > 0)
334f485d
MS
1895 goto err_finish;
1896
d7133114 1897 spin_lock(&fc->lock);
69a53bf2
MS
1898 err = -ENOENT;
1899 if (!fc->connected)
1900 goto err_unlock;
1901
334f485d 1902 req = request_find(fc, oh.unique);
334f485d
MS
1903 if (!req)
1904 goto err_unlock;
1905
a4d27e75
MS
1906 /* Is it an interrupt reply? */
1907 if (req->intr_unique == oh.unique) {
1908 err = -EINVAL;
1909 if (nbytes != sizeof(struct fuse_out_header))
1910 goto err_unlock;
1911
1912 if (oh.error == -ENOSYS)
1913 fc->no_interrupt = 1;
1914 else if (oh.error == -EAGAIN)
f88996a9 1915 queue_interrupt(&fc->iq, req);
a4d27e75
MS
1916
1917 spin_unlock(&fc->lock);
dd3bb14f 1918 fuse_copy_finish(cs);
a4d27e75
MS
1919 return nbytes;
1920 }
1921
33e14b4d 1922 clear_bit(FR_SENT, &req->flags);
d77a1d5b 1923 list_move(&req->list, &fc->io);
334f485d 1924 req->out.h = oh;
825d6d33 1925 set_bit(FR_LOCKED, &req->flags);
dd3bb14f 1926 cs->req = req;
ce534fb0
MS
1927 if (!req->out.page_replace)
1928 cs->move_pages = 0;
d7133114 1929 spin_unlock(&fc->lock);
334f485d 1930
dd3bb14f
MS
1931 err = copy_out_args(cs, &req->out, nbytes);
1932 fuse_copy_finish(cs);
334f485d 1933
d7133114 1934 spin_lock(&fc->lock);
825d6d33 1935 clear_bit(FR_LOCKED, &req->flags);
0d8e84b0
MS
1936 if (!fc->connected)
1937 err = -ENOENT;
1938 else if (err)
334f485d
MS
1939 req->out.h.error = -EIO;
1940 request_end(fc, req);
1941
1942 return err ? err : nbytes;
1943
1944 err_unlock:
d7133114 1945 spin_unlock(&fc->lock);
334f485d 1946 err_finish:
dd3bb14f 1947 fuse_copy_finish(cs);
334f485d
MS
1948 return err;
1949}
1950
fbdbacca 1951static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
dd3bb14f
MS
1952{
1953 struct fuse_copy_state cs;
1954 struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
1955 if (!fc)
1956 return -EPERM;
1957
fbdbacca
AV
1958 if (!iter_is_iovec(from))
1959 return -EINVAL;
1960
dc00809a 1961 fuse_copy_init(&cs, 0, from);
dd3bb14f 1962
fbdbacca 1963 return fuse_dev_do_write(fc, &cs, iov_iter_count(from));
dd3bb14f
MS
1964}
1965
1966static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1967 struct file *out, loff_t *ppos,
1968 size_t len, unsigned int flags)
1969{
1970 unsigned nbuf;
1971 unsigned idx;
1972 struct pipe_buffer *bufs;
1973 struct fuse_copy_state cs;
1974 struct fuse_conn *fc;
1975 size_t rem;
1976 ssize_t ret;
1977
1978 fc = fuse_get_conn(out);
1979 if (!fc)
1980 return -EPERM;
1981
07e77dca 1982 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
dd3bb14f
MS
1983 if (!bufs)
1984 return -ENOMEM;
1985
1986 pipe_lock(pipe);
1987 nbuf = 0;
1988 rem = 0;
1989 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
1990 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
1991
1992 ret = -EINVAL;
1993 if (rem < len) {
1994 pipe_unlock(pipe);
1995 goto out;
1996 }
1997
1998 rem = len;
1999 while (rem) {
2000 struct pipe_buffer *ibuf;
2001 struct pipe_buffer *obuf;
2002
2003 BUG_ON(nbuf >= pipe->buffers);
2004 BUG_ON(!pipe->nrbufs);
2005 ibuf = &pipe->bufs[pipe->curbuf];
2006 obuf = &bufs[nbuf];
2007
2008 if (rem >= ibuf->len) {
2009 *obuf = *ibuf;
2010 ibuf->ops = NULL;
2011 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
2012 pipe->nrbufs--;
2013 } else {
2014 ibuf->ops->get(pipe, ibuf);
2015 *obuf = *ibuf;
2016 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
2017 obuf->len = rem;
2018 ibuf->offset += obuf->len;
2019 ibuf->len -= obuf->len;
2020 }
2021 nbuf++;
2022 rem -= obuf->len;
2023 }
2024 pipe_unlock(pipe);
2025
dc00809a 2026 fuse_copy_init(&cs, 0, NULL);
dd3bb14f 2027 cs.pipebufs = bufs;
6c09e94a 2028 cs.nr_segs = nbuf;
dd3bb14f
MS
2029 cs.pipe = pipe;
2030
ce534fb0
MS
2031 if (flags & SPLICE_F_MOVE)
2032 cs.move_pages = 1;
2033
dd3bb14f
MS
2034 ret = fuse_dev_do_write(fc, &cs, len);
2035
2036 for (idx = 0; idx < nbuf; idx++) {
2037 struct pipe_buffer *buf = &bufs[idx];
2038 buf->ops->release(pipe, buf);
2039 }
2040out:
2041 kfree(bufs);
2042 return ret;
2043}
2044
334f485d
MS
2045static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
2046{
334f485d 2047 unsigned mask = POLLOUT | POLLWRNORM;
f88996a9 2048 struct fuse_iqueue *fiq;
7025d9ad 2049 struct fuse_conn *fc = fuse_get_conn(file);
334f485d 2050 if (!fc)
7025d9ad 2051 return POLLERR;
334f485d 2052
f88996a9
MS
2053 fiq = &fc->iq;
2054 poll_wait(file, &fiq->waitq, wait);
334f485d 2055
d7133114 2056 spin_lock(&fc->lock);
e16714d8 2057 if (!fiq->connected)
7025d9ad 2058 mask = POLLERR;
f88996a9 2059 else if (request_pending(fiq))
7025d9ad 2060 mask |= POLLIN | POLLRDNORM;
d7133114 2061 spin_unlock(&fc->lock);
334f485d
MS
2062
2063 return mask;
2064}
2065
69a53bf2
MS
2066/*
2067 * Abort all requests on the given list (pending or processing)
2068 *
d7133114 2069 * This function releases and reacquires fc->lock
69a53bf2 2070 */
334f485d 2071static void end_requests(struct fuse_conn *fc, struct list_head *head)
b9ca67b2
MS
2072__releases(fc->lock)
2073__acquires(fc->lock)
334f485d
MS
2074{
2075 while (!list_empty(head)) {
2076 struct fuse_req *req;
2077 req = list_entry(head->next, struct fuse_req, list);
334f485d 2078 req->out.h.error = -ECONNABORTED;
33e14b4d
MS
2079 clear_bit(FR_PENDING, &req->flags);
2080 clear_bit(FR_SENT, &req->flags);
334f485d 2081 request_end(fc, req);
d7133114 2082 spin_lock(&fc->lock);
334f485d
MS
2083 }
2084}
2085
357ccf2b
BG
2086static void end_polls(struct fuse_conn *fc)
2087{
2088 struct rb_node *p;
2089
2090 p = rb_first(&fc->polled_files);
2091
2092 while (p) {
2093 struct fuse_file *ff;
2094 ff = rb_entry(p, struct fuse_file, polled_node);
2095 wake_up_interruptible_all(&ff->poll_wait);
2096
2097 p = rb_next(p);
2098 }
2099}
2100
69a53bf2
MS
2101/*
2102 * Abort all requests.
2103 *
b716d425
MS
2104 * Emergency exit in case of a malicious or accidental deadlock, or just a hung
2105 * filesystem.
2106 *
2107 * The same effect is usually achievable through killing the filesystem daemon
2108 * and all users of the filesystem. The exception is the combination of an
2109 * asynchronous request and the tricky deadlock (see
2110 * Documentation/filesystems/fuse.txt).
69a53bf2 2111 *
b716d425
MS
2112 * Aborting requests under I/O goes as follows: 1: Separate out unlocked
2113 * requests, they should be finished off immediately. Locked requests will be
2114 * finished after unlock; see unlock_request(). 2: Finish off the unlocked
2115 * requests. It is possible that some request will finish before we can. This
2116 * is OK, the request will in that case be removed from the list before we touch
2117 * it.
69a53bf2
MS
2118 */
2119void fuse_abort_conn(struct fuse_conn *fc)
2120{
f88996a9
MS
2121 struct fuse_iqueue *fiq = &fc->iq;
2122
d7133114 2123 spin_lock(&fc->lock);
69a53bf2 2124 if (fc->connected) {
b716d425 2125 struct fuse_req *req, *next;
41f98274
MS
2126 LIST_HEAD(to_end1);
2127 LIST_HEAD(to_end2);
b716d425 2128
69a53bf2 2129 fc->connected = 0;
e16714d8 2130 fiq->connected = 0;
51eb01e7 2131 fc->blocked = 0;
9759bd51 2132 fuse_set_initialized(fc);
b716d425
MS
2133 list_for_each_entry_safe(req, next, &fc->io, list) {
2134 req->out.h.error = -ECONNABORTED;
2135 spin_lock(&req->waitq.lock);
2136 set_bit(FR_ABORTED, &req->flags);
2137 if (!test_bit(FR_LOCKED, &req->flags))
41f98274 2138 list_move(&req->list, &to_end1);
b716d425
MS
2139 spin_unlock(&req->waitq.lock);
2140 }
41f98274
MS
2141 fc->max_background = UINT_MAX;
2142 flush_bg_queue(fc);
f88996a9 2143 list_splice_init(&fiq->pending, &to_end2);
41f98274
MS
2144 list_splice_init(&fc->processing, &to_end2);
2145 while (!list_empty(&to_end1)) {
2146 req = list_first_entry(&to_end1, struct fuse_req, list);
b716d425
MS
2147 __fuse_get_request(req);
2148 request_end(fc, req);
2149 spin_lock(&fc->lock);
2150 }
41f98274 2151 end_requests(fc, &to_end2);
f88996a9
MS
2152 while (forget_pending(fiq))
2153 kfree(dequeue_forget(fiq, 1, NULL));
357ccf2b 2154 end_polls(fc);
f88996a9 2155 wake_up_all(&fiq->waitq);
51eb01e7 2156 wake_up_all(&fc->blocked_waitq);
f88996a9 2157 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
69a53bf2 2158 }
d7133114 2159 spin_unlock(&fc->lock);
69a53bf2 2160}
08cbf542 2161EXPORT_SYMBOL_GPL(fuse_abort_conn);
69a53bf2 2162
08cbf542 2163int fuse_dev_release(struct inode *inode, struct file *file)
334f485d 2164{
0720b315 2165 struct fuse_conn *fc = fuse_get_conn(file);
334f485d 2166 if (fc) {
ccd0a0bd 2167 WARN_ON(!list_empty(&fc->io));
f88996a9 2168 WARN_ON(fc->iq.fasync != NULL);
ccd0a0bd 2169 fuse_abort_conn(fc);
bafa9654 2170 fuse_conn_put(fc);
385a17bf 2171 }
f543f253 2172
334f485d
MS
2173 return 0;
2174}
08cbf542 2175EXPORT_SYMBOL_GPL(fuse_dev_release);
334f485d 2176
385a17bf
JD
2177static int fuse_dev_fasync(int fd, struct file *file, int on)
2178{
2179 struct fuse_conn *fc = fuse_get_conn(file);
2180 if (!fc)
a87046d8 2181 return -EPERM;
385a17bf
JD
2182
2183 /* No locking - fasync_helper does its own locking */
f88996a9 2184 return fasync_helper(fd, file, on, &fc->iq.fasync);
385a17bf
JD
2185}
2186
4b6f5d20 2187const struct file_operations fuse_dev_operations = {
334f485d 2188 .owner = THIS_MODULE,
94e4fe2c 2189 .open = fuse_dev_open,
334f485d 2190 .llseek = no_llseek,
fbdbacca 2191 .read_iter = fuse_dev_read,
c3021629 2192 .splice_read = fuse_dev_splice_read,
fbdbacca 2193 .write_iter = fuse_dev_write,
dd3bb14f 2194 .splice_write = fuse_dev_splice_write,
334f485d
MS
2195 .poll = fuse_dev_poll,
2196 .release = fuse_dev_release,
385a17bf 2197 .fasync = fuse_dev_fasync,
334f485d 2198};
08cbf542 2199EXPORT_SYMBOL_GPL(fuse_dev_operations);
334f485d
MS
2200
2201static struct miscdevice fuse_miscdevice = {
2202 .minor = FUSE_MINOR,
2203 .name = "fuse",
2204 .fops = &fuse_dev_operations,
2205};
2206
2207int __init fuse_dev_init(void)
2208{
2209 int err = -ENOMEM;
2210 fuse_req_cachep = kmem_cache_create("fuse_request",
2211 sizeof(struct fuse_req),
20c2df83 2212 0, 0, NULL);
334f485d
MS
2213 if (!fuse_req_cachep)
2214 goto out;
2215
2216 err = misc_register(&fuse_miscdevice);
2217 if (err)
2218 goto out_cache_clean;
2219
2220 return 0;
2221
2222 out_cache_clean:
2223 kmem_cache_destroy(fuse_req_cachep);
2224 out:
2225 return err;
2226}
2227
2228void fuse_dev_cleanup(void)
2229{
2230 misc_deregister(&fuse_miscdevice);
2231 kmem_cache_destroy(fuse_req_cachep);
2232}