2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
5 This program can be distributed under the terms of the GNU GPL.
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/poll.h>
14 #include <linux/uio.h>
15 #include <linux/miscdevice.h>
16 #include <linux/pagemap.h>
17 #include <linux/file.h>
18 #include <linux/slab.h>
19 #include <linux/pipe_fs_i.h>
20 #include <linux/swap.h>
21 #include <linux/splice.h>
23 MODULE_ALIAS_MISCDEV(FUSE_MINOR
);
24 MODULE_ALIAS("devname:fuse");
26 static struct kmem_cache
*fuse_req_cachep
;
28 static struct fuse_conn
*fuse_get_conn(struct file
*file
)
31 * Lockless access is OK, because file->private data is set
32 * once during mount and is valid until the file is released.
34 return file
->private_data
;
37 static void fuse_request_init(struct fuse_req
*req
, struct page
**pages
,
38 struct fuse_page_desc
*page_descs
,
41 memset(req
, 0, sizeof(*req
));
42 memset(pages
, 0, sizeof(*pages
) * npages
);
43 memset(page_descs
, 0, sizeof(*page_descs
) * npages
);
44 INIT_LIST_HEAD(&req
->list
);
45 INIT_LIST_HEAD(&req
->intr_entry
);
46 init_waitqueue_head(&req
->waitq
);
47 atomic_set(&req
->count
, 1);
49 req
->page_descs
= page_descs
;
50 req
->max_pages
= npages
;
51 __set_bit(FR_PENDING
, &req
->flags
);
54 static struct fuse_req
*__fuse_request_alloc(unsigned npages
, gfp_t flags
)
56 struct fuse_req
*req
= kmem_cache_alloc(fuse_req_cachep
, flags
);
59 struct fuse_page_desc
*page_descs
;
61 if (npages
<= FUSE_REQ_INLINE_PAGES
) {
62 pages
= req
->inline_pages
;
63 page_descs
= req
->inline_page_descs
;
65 pages
= kmalloc(sizeof(struct page
*) * npages
, flags
);
66 page_descs
= kmalloc(sizeof(struct fuse_page_desc
) *
70 if (!pages
|| !page_descs
) {
73 kmem_cache_free(fuse_req_cachep
, req
);
77 fuse_request_init(req
, pages
, page_descs
, npages
);
82 struct fuse_req
*fuse_request_alloc(unsigned npages
)
84 return __fuse_request_alloc(npages
, GFP_KERNEL
);
86 EXPORT_SYMBOL_GPL(fuse_request_alloc
);
88 struct fuse_req
*fuse_request_alloc_nofs(unsigned npages
)
90 return __fuse_request_alloc(npages
, GFP_NOFS
);
93 void fuse_request_free(struct fuse_req
*req
)
95 if (req
->pages
!= req
->inline_pages
) {
97 kfree(req
->page_descs
);
99 kmem_cache_free(fuse_req_cachep
, req
);
102 static void block_sigs(sigset_t
*oldset
)
106 siginitsetinv(&mask
, sigmask(SIGKILL
));
107 sigprocmask(SIG_BLOCK
, &mask
, oldset
);
110 static void restore_sigs(sigset_t
*oldset
)
112 sigprocmask(SIG_SETMASK
, oldset
, NULL
);
115 void __fuse_get_request(struct fuse_req
*req
)
117 atomic_inc(&req
->count
);
120 /* Must be called with > 1 refcount */
121 static void __fuse_put_request(struct fuse_req
*req
)
123 BUG_ON(atomic_read(&req
->count
) < 2);
124 atomic_dec(&req
->count
);
127 static void fuse_req_init_context(struct fuse_req
*req
)
129 req
->in
.h
.uid
= from_kuid_munged(&init_user_ns
, current_fsuid());
130 req
->in
.h
.gid
= from_kgid_munged(&init_user_ns
, current_fsgid());
131 req
->in
.h
.pid
= current
->pid
;
134 void fuse_set_initialized(struct fuse_conn
*fc
)
136 /* Make sure stores before this are seen on another CPU */
141 static bool fuse_block_alloc(struct fuse_conn
*fc
, bool for_background
)
143 return !fc
->initialized
|| (for_background
&& fc
->blocked
);
146 static struct fuse_req
*__fuse_get_req(struct fuse_conn
*fc
, unsigned npages
,
149 struct fuse_req
*req
;
151 atomic_inc(&fc
->num_waiting
);
153 if (fuse_block_alloc(fc
, for_background
)) {
158 intr
= wait_event_interruptible_exclusive(fc
->blocked_waitq
,
159 !fuse_block_alloc(fc
, for_background
));
160 restore_sigs(&oldset
);
165 /* Matches smp_wmb() in fuse_set_initialized() */
176 req
= fuse_request_alloc(npages
);
180 wake_up(&fc
->blocked_waitq
);
184 fuse_req_init_context(req
);
185 __set_bit(FR_WAITING
, &req
->flags
);
187 __set_bit(FR_BACKGROUND
, &req
->flags
);
192 atomic_dec(&fc
->num_waiting
);
196 struct fuse_req
*fuse_get_req(struct fuse_conn
*fc
, unsigned npages
)
198 return __fuse_get_req(fc
, npages
, false);
200 EXPORT_SYMBOL_GPL(fuse_get_req
);
202 struct fuse_req
*fuse_get_req_for_background(struct fuse_conn
*fc
,
205 return __fuse_get_req(fc
, npages
, true);
207 EXPORT_SYMBOL_GPL(fuse_get_req_for_background
);
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
214 static struct fuse_req
*get_reserved_req(struct fuse_conn
*fc
,
217 struct fuse_req
*req
= NULL
;
218 struct fuse_file
*ff
= file
->private_data
;
221 wait_event(fc
->reserved_req_waitq
, ff
->reserved_req
);
222 spin_lock(&fc
->lock
);
223 if (ff
->reserved_req
) {
224 req
= ff
->reserved_req
;
225 ff
->reserved_req
= NULL
;
226 req
->stolen_file
= get_file(file
);
228 spin_unlock(&fc
->lock
);
235 * Put stolen request back into fuse_file->reserved_req
237 static void put_reserved_req(struct fuse_conn
*fc
, struct fuse_req
*req
)
239 struct file
*file
= req
->stolen_file
;
240 struct fuse_file
*ff
= file
->private_data
;
242 spin_lock(&fc
->lock
);
243 fuse_request_init(req
, req
->pages
, req
->page_descs
, req
->max_pages
);
244 BUG_ON(ff
->reserved_req
);
245 ff
->reserved_req
= req
;
246 wake_up_all(&fc
->reserved_req_waitq
);
247 spin_unlock(&fc
->lock
);
252 * Gets a requests for a file operation, always succeeds
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.
257 * If allocation fails due to OOM, use the reserved request in
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.
264 struct fuse_req
*fuse_get_req_nofail_nopages(struct fuse_conn
*fc
,
267 struct fuse_req
*req
;
269 atomic_inc(&fc
->num_waiting
);
270 wait_event(fc
->blocked_waitq
, fc
->initialized
);
271 /* Matches smp_wmb() in fuse_set_initialized() */
273 req
= fuse_request_alloc(0);
275 req
= get_reserved_req(fc
, file
);
277 fuse_req_init_context(req
);
278 __set_bit(FR_WAITING
, &req
->flags
);
279 __clear_bit(FR_BACKGROUND
, &req
->flags
);
283 void fuse_put_request(struct fuse_conn
*fc
, struct fuse_req
*req
)
285 if (atomic_dec_and_test(&req
->count
)) {
286 if (test_bit(FR_BACKGROUND
, &req
->flags
)) {
288 * We get here in the unlikely case that a background
289 * request was allocated but not sent
291 spin_lock(&fc
->lock
);
293 wake_up(&fc
->blocked_waitq
);
294 spin_unlock(&fc
->lock
);
297 if (test_bit(FR_WAITING
, &req
->flags
)) {
298 __clear_bit(FR_WAITING
, &req
->flags
);
299 atomic_dec(&fc
->num_waiting
);
302 if (req
->stolen_file
)
303 put_reserved_req(fc
, req
);
305 fuse_request_free(req
);
308 EXPORT_SYMBOL_GPL(fuse_put_request
);
310 static unsigned len_args(unsigned numargs
, struct fuse_arg
*args
)
315 for (i
= 0; i
< numargs
; i
++)
316 nbytes
+= args
[i
].size
;
321 static u64
fuse_get_unique(struct fuse_iqueue
*fiq
)
323 return ++fiq
->reqctr
;
326 static void queue_request(struct fuse_iqueue
*fiq
, struct fuse_req
*req
)
328 req
->in
.h
.len
= sizeof(struct fuse_in_header
) +
329 len_args(req
->in
.numargs
, (struct fuse_arg
*) req
->in
.args
);
330 list_add_tail(&req
->list
, &fiq
->pending
);
331 wake_up_locked(&fiq
->waitq
);
332 kill_fasync(&fiq
->fasync
, SIGIO
, POLL_IN
);
335 void fuse_queue_forget(struct fuse_conn
*fc
, struct fuse_forget_link
*forget
,
336 u64 nodeid
, u64 nlookup
)
338 struct fuse_iqueue
*fiq
= &fc
->iq
;
340 forget
->forget_one
.nodeid
= nodeid
;
341 forget
->forget_one
.nlookup
= nlookup
;
343 spin_lock(&fiq
->waitq
.lock
);
344 if (fiq
->connected
) {
345 fiq
->forget_list_tail
->next
= forget
;
346 fiq
->forget_list_tail
= forget
;
347 wake_up_locked(&fiq
->waitq
);
348 kill_fasync(&fiq
->fasync
, SIGIO
, POLL_IN
);
352 spin_unlock(&fiq
->waitq
.lock
);
355 static void flush_bg_queue(struct fuse_conn
*fc
)
357 while (fc
->active_background
< fc
->max_background
&&
358 !list_empty(&fc
->bg_queue
)) {
359 struct fuse_req
*req
;
360 struct fuse_iqueue
*fiq
= &fc
->iq
;
362 req
= list_entry(fc
->bg_queue
.next
, struct fuse_req
, list
);
363 list_del(&req
->list
);
364 fc
->active_background
++;
365 spin_lock(&fiq
->waitq
.lock
);
366 req
->in
.h
.unique
= fuse_get_unique(fiq
);
367 queue_request(fiq
, req
);
368 spin_unlock(&fiq
->waitq
.lock
);
373 * This function is called when a request is finished. Either a reply
374 * has arrived or it was aborted (and not yet sent) or some error
375 * occurred during communication with userspace, or the device file
376 * was closed. The requester thread is woken up (if still waiting),
377 * the 'end' callback is called if given, else the reference to the
378 * request is released
380 * Called with fc->lock, unlocks it
382 static void request_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
385 struct fuse_iqueue
*fiq
= &fc
->iq
;
386 void (*end
) (struct fuse_conn
*, struct fuse_req
*) = req
->end
;
388 spin_lock(&fiq
->waitq
.lock
);
389 list_del_init(&req
->intr_entry
);
390 spin_unlock(&fiq
->waitq
.lock
);
391 WARN_ON(test_bit(FR_PENDING
, &req
->flags
));
392 WARN_ON(test_bit(FR_SENT
, &req
->flags
));
394 set_bit(FR_FINISHED
, &req
->flags
);
395 if (test_bit(FR_BACKGROUND
, &req
->flags
)) {
396 clear_bit(FR_BACKGROUND
, &req
->flags
);
397 if (fc
->num_background
== fc
->max_background
)
400 /* Wake up next waiter, if any */
401 if (!fc
->blocked
&& waitqueue_active(&fc
->blocked_waitq
))
402 wake_up(&fc
->blocked_waitq
);
404 if (fc
->num_background
== fc
->congestion_threshold
&&
405 fc
->connected
&& fc
->bdi_initialized
) {
406 clear_bdi_congested(&fc
->bdi
, BLK_RW_SYNC
);
407 clear_bdi_congested(&fc
->bdi
, BLK_RW_ASYNC
);
409 fc
->num_background
--;
410 fc
->active_background
--;
413 spin_unlock(&fc
->lock
);
414 wake_up(&req
->waitq
);
417 fuse_put_request(fc
, req
);
420 static void queue_interrupt(struct fuse_iqueue
*fiq
, struct fuse_req
*req
)
422 spin_lock(&fiq
->waitq
.lock
);
423 if (list_empty(&req
->intr_entry
)) {
424 list_add_tail(&req
->intr_entry
, &fiq
->interrupts
);
425 wake_up_locked(&fiq
->waitq
);
427 spin_unlock(&fiq
->waitq
.lock
);
428 kill_fasync(&fiq
->fasync
, SIGIO
, POLL_IN
);
431 static void request_wait_answer(struct fuse_conn
*fc
, struct fuse_req
*req
)
433 struct fuse_iqueue
*fiq
= &fc
->iq
;
436 if (!fc
->no_interrupt
) {
437 /* Any signal may interrupt this */
438 err
= wait_event_interruptible(req
->waitq
,
439 test_bit(FR_FINISHED
, &req
->flags
));
443 set_bit(FR_INTERRUPTED
, &req
->flags
);
444 /* matches barrier in fuse_dev_do_read() */
445 smp_mb__after_atomic();
446 if (test_bit(FR_SENT
, &req
->flags
))
447 queue_interrupt(fiq
, req
);
450 if (!test_bit(FR_FORCE
, &req
->flags
)) {
453 /* Only fatal signals may interrupt this */
455 err
= wait_event_interruptible(req
->waitq
,
456 test_bit(FR_FINISHED
, &req
->flags
));
457 restore_sigs(&oldset
);
462 spin_lock(&fiq
->waitq
.lock
);
463 /* Request is not yet in userspace, bail out */
464 if (test_bit(FR_PENDING
, &req
->flags
)) {
465 list_del(&req
->list
);
466 spin_unlock(&fiq
->waitq
.lock
);
467 __fuse_put_request(req
);
468 req
->out
.h
.error
= -EINTR
;
471 spin_unlock(&fiq
->waitq
.lock
);
475 * Either request is already in userspace, or it was forced.
478 wait_event(req
->waitq
, test_bit(FR_FINISHED
, &req
->flags
));
481 static void __fuse_request_send(struct fuse_conn
*fc
, struct fuse_req
*req
)
483 struct fuse_iqueue
*fiq
= &fc
->iq
;
485 BUG_ON(test_bit(FR_BACKGROUND
, &req
->flags
));
486 spin_lock(&fiq
->waitq
.lock
);
487 if (!fiq
->connected
) {
488 spin_unlock(&fiq
->waitq
.lock
);
489 req
->out
.h
.error
= -ENOTCONN
;
491 req
->in
.h
.unique
= fuse_get_unique(fiq
);
492 queue_request(fiq
, req
);
493 /* acquire extra reference, since request is still needed
494 after request_end() */
495 __fuse_get_request(req
);
496 spin_unlock(&fiq
->waitq
.lock
);
498 request_wait_answer(fc
, req
);
499 /* Pairs with smp_wmb() in request_end() */
504 void fuse_request_send(struct fuse_conn
*fc
, struct fuse_req
*req
)
506 __set_bit(FR_ISREPLY
, &req
->flags
);
507 if (!test_bit(FR_WAITING
, &req
->flags
)) {
508 __set_bit(FR_WAITING
, &req
->flags
);
509 atomic_inc(&fc
->num_waiting
);
511 __fuse_request_send(fc
, req
);
513 EXPORT_SYMBOL_GPL(fuse_request_send
);
515 static void fuse_adjust_compat(struct fuse_conn
*fc
, struct fuse_args
*args
)
517 if (fc
->minor
< 4 && args
->in
.h
.opcode
== FUSE_STATFS
)
518 args
->out
.args
[0].size
= FUSE_COMPAT_STATFS_SIZE
;
521 switch (args
->in
.h
.opcode
) {
528 args
->out
.args
[0].size
= FUSE_COMPAT_ENTRY_OUT_SIZE
;
532 args
->out
.args
[0].size
= FUSE_COMPAT_ATTR_OUT_SIZE
;
536 if (fc
->minor
< 12) {
537 switch (args
->in
.h
.opcode
) {
539 args
->in
.args
[0].size
= sizeof(struct fuse_open_in
);
542 args
->in
.args
[0].size
= FUSE_COMPAT_MKNOD_IN_SIZE
;
548 ssize_t
fuse_simple_request(struct fuse_conn
*fc
, struct fuse_args
*args
)
550 struct fuse_req
*req
;
553 req
= fuse_get_req(fc
, 0);
557 /* Needs to be done after fuse_get_req() so that fc->minor is valid */
558 fuse_adjust_compat(fc
, args
);
560 req
->in
.h
.opcode
= args
->in
.h
.opcode
;
561 req
->in
.h
.nodeid
= args
->in
.h
.nodeid
;
562 req
->in
.numargs
= args
->in
.numargs
;
563 memcpy(req
->in
.args
, args
->in
.args
,
564 args
->in
.numargs
* sizeof(struct fuse_in_arg
));
565 req
->out
.argvar
= args
->out
.argvar
;
566 req
->out
.numargs
= args
->out
.numargs
;
567 memcpy(req
->out
.args
, args
->out
.args
,
568 args
->out
.numargs
* sizeof(struct fuse_arg
));
569 fuse_request_send(fc
, req
);
570 ret
= req
->out
.h
.error
;
571 if (!ret
&& args
->out
.argvar
) {
572 BUG_ON(args
->out
.numargs
!= 1);
573 ret
= req
->out
.args
[0].size
;
575 fuse_put_request(fc
, req
);
581 * Called under fc->lock
583 * fc->connected must have been checked previously
585 void fuse_request_send_background_locked(struct fuse_conn
*fc
,
586 struct fuse_req
*req
)
588 BUG_ON(!test_bit(FR_BACKGROUND
, &req
->flags
));
589 if (!test_bit(FR_WAITING
, &req
->flags
)) {
590 __set_bit(FR_WAITING
, &req
->flags
);
591 atomic_inc(&fc
->num_waiting
);
593 __set_bit(FR_ISREPLY
, &req
->flags
);
594 fc
->num_background
++;
595 if (fc
->num_background
== fc
->max_background
)
597 if (fc
->num_background
== fc
->congestion_threshold
&&
598 fc
->bdi_initialized
) {
599 set_bdi_congested(&fc
->bdi
, BLK_RW_SYNC
);
600 set_bdi_congested(&fc
->bdi
, BLK_RW_ASYNC
);
602 list_add_tail(&req
->list
, &fc
->bg_queue
);
606 void fuse_request_send_background(struct fuse_conn
*fc
, struct fuse_req
*req
)
609 spin_lock(&fc
->lock
);
611 fuse_request_send_background_locked(fc
, req
);
612 spin_unlock(&fc
->lock
);
614 spin_unlock(&fc
->lock
);
615 req
->out
.h
.error
= -ENOTCONN
;
617 fuse_put_request(fc
, req
);
620 EXPORT_SYMBOL_GPL(fuse_request_send_background
);
622 static int fuse_request_send_notify_reply(struct fuse_conn
*fc
,
623 struct fuse_req
*req
, u64 unique
)
626 struct fuse_iqueue
*fiq
= &fc
->iq
;
628 __clear_bit(FR_ISREPLY
, &req
->flags
);
629 req
->in
.h
.unique
= unique
;
630 spin_lock(&fiq
->waitq
.lock
);
631 if (fiq
->connected
) {
632 queue_request(fiq
, req
);
635 spin_unlock(&fiq
->waitq
.lock
);
640 void fuse_force_forget(struct file
*file
, u64 nodeid
)
642 struct inode
*inode
= file_inode(file
);
643 struct fuse_conn
*fc
= get_fuse_conn(inode
);
644 struct fuse_req
*req
;
645 struct fuse_forget_in inarg
;
647 memset(&inarg
, 0, sizeof(inarg
));
649 req
= fuse_get_req_nofail_nopages(fc
, file
);
650 req
->in
.h
.opcode
= FUSE_FORGET
;
651 req
->in
.h
.nodeid
= nodeid
;
653 req
->in
.args
[0].size
= sizeof(inarg
);
654 req
->in
.args
[0].value
= &inarg
;
655 __clear_bit(FR_ISREPLY
, &req
->flags
);
656 __fuse_request_send(fc
, req
);
658 fuse_put_request(fc
, req
);
662 * Lock the request. Up to the next unlock_request() there mustn't be
663 * anything that could cause a page-fault. If the request was already
666 static int lock_request(struct fuse_req
*req
)
670 spin_lock(&req
->waitq
.lock
);
671 if (test_bit(FR_ABORTED
, &req
->flags
))
674 set_bit(FR_LOCKED
, &req
->flags
);
675 spin_unlock(&req
->waitq
.lock
);
681 * Unlock request. If it was aborted while locked, caller is responsible
682 * for unlocking and ending the request.
684 static int unlock_request(struct fuse_req
*req
)
688 spin_lock(&req
->waitq
.lock
);
689 if (test_bit(FR_ABORTED
, &req
->flags
))
692 clear_bit(FR_LOCKED
, &req
->flags
);
693 spin_unlock(&req
->waitq
.lock
);
698 struct fuse_copy_state
{
700 struct fuse_req
*req
;
701 struct iov_iter
*iter
;
702 struct pipe_buffer
*pipebufs
;
703 struct pipe_buffer
*currbuf
;
704 struct pipe_inode_info
*pipe
;
705 unsigned long nr_segs
;
709 unsigned move_pages
:1;
712 static void fuse_copy_init(struct fuse_copy_state
*cs
, int write
,
713 struct iov_iter
*iter
)
715 memset(cs
, 0, sizeof(*cs
));
720 /* Unmap and put previous page of userspace buffer */
721 static void fuse_copy_finish(struct fuse_copy_state
*cs
)
724 struct pipe_buffer
*buf
= cs
->currbuf
;
727 buf
->len
= PAGE_SIZE
- cs
->len
;
731 flush_dcache_page(cs
->pg
);
732 set_page_dirty_lock(cs
->pg
);
740 * Get another pagefull of userspace buffer, and map it to kernel
741 * address space, and lock request
743 static int fuse_copy_fill(struct fuse_copy_state
*cs
)
748 err
= unlock_request(cs
->req
);
752 fuse_copy_finish(cs
);
754 struct pipe_buffer
*buf
= cs
->pipebufs
;
757 err
= buf
->ops
->confirm(cs
->pipe
, buf
);
761 BUG_ON(!cs
->nr_segs
);
764 cs
->offset
= buf
->offset
;
769 if (cs
->nr_segs
== cs
->pipe
->buffers
)
772 page
= alloc_page(GFP_HIGHUSER
);
789 err
= iov_iter_get_pages(cs
->iter
, &page
, PAGE_SIZE
, 1, &off
);
797 iov_iter_advance(cs
->iter
, err
);
800 return lock_request(cs
->req
);
803 /* Do as much copy to/from userspace buffer as we can */
804 static int fuse_copy_do(struct fuse_copy_state
*cs
, void **val
, unsigned *size
)
806 unsigned ncpy
= min(*size
, cs
->len
);
808 void *pgaddr
= kmap_atomic(cs
->pg
);
809 void *buf
= pgaddr
+ cs
->offset
;
812 memcpy(buf
, *val
, ncpy
);
814 memcpy(*val
, buf
, ncpy
);
816 kunmap_atomic(pgaddr
);
825 static int fuse_check_page(struct page
*page
)
827 if (page_mapcount(page
) ||
828 page
->mapping
!= NULL
||
829 page_count(page
) != 1 ||
830 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
&
837 printk(KERN_WARNING
"fuse: trying to steal weird page\n");
838 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
);
844 static int fuse_try_move_page(struct fuse_copy_state
*cs
, struct page
**pagep
)
847 struct page
*oldpage
= *pagep
;
848 struct page
*newpage
;
849 struct pipe_buffer
*buf
= cs
->pipebufs
;
851 err
= unlock_request(cs
->req
);
855 fuse_copy_finish(cs
);
857 err
= buf
->ops
->confirm(cs
->pipe
, buf
);
861 BUG_ON(!cs
->nr_segs
);
867 if (cs
->len
!= PAGE_SIZE
)
870 if (buf
->ops
->steal(cs
->pipe
, buf
) != 0)
875 if (!PageUptodate(newpage
))
876 SetPageUptodate(newpage
);
878 ClearPageMappedToDisk(newpage
);
880 if (fuse_check_page(newpage
) != 0)
881 goto out_fallback_unlock
;
884 * This is a new and locked page, it shouldn't be mapped or
885 * have any special flags on it
887 if (WARN_ON(page_mapped(oldpage
)))
888 goto out_fallback_unlock
;
889 if (WARN_ON(page_has_private(oldpage
)))
890 goto out_fallback_unlock
;
891 if (WARN_ON(PageDirty(oldpage
) || PageWriteback(oldpage
)))
892 goto out_fallback_unlock
;
893 if (WARN_ON(PageMlocked(oldpage
)))
894 goto out_fallback_unlock
;
896 err
= replace_page_cache_page(oldpage
, newpage
, GFP_KERNEL
);
898 unlock_page(newpage
);
902 page_cache_get(newpage
);
904 if (!(buf
->flags
& PIPE_BUF_FLAG_LRU
))
905 lru_cache_add_file(newpage
);
908 spin_lock(&cs
->req
->waitq
.lock
);
909 if (test_bit(FR_ABORTED
, &cs
->req
->flags
))
913 spin_unlock(&cs
->req
->waitq
.lock
);
916 unlock_page(newpage
);
917 page_cache_release(newpage
);
921 unlock_page(oldpage
);
922 page_cache_release(oldpage
);
928 unlock_page(newpage
);
931 cs
->offset
= buf
->offset
;
933 err
= lock_request(cs
->req
);
940 static int fuse_ref_page(struct fuse_copy_state
*cs
, struct page
*page
,
941 unsigned offset
, unsigned count
)
943 struct pipe_buffer
*buf
;
946 if (cs
->nr_segs
== cs
->pipe
->buffers
)
949 err
= unlock_request(cs
->req
);
953 fuse_copy_finish(cs
);
956 page_cache_get(page
);
958 buf
->offset
= offset
;
969 * Copy a page in the request to/from the userspace buffer. Must be
972 static int fuse_copy_page(struct fuse_copy_state
*cs
, struct page
**pagep
,
973 unsigned offset
, unsigned count
, int zeroing
)
976 struct page
*page
= *pagep
;
978 if (page
&& zeroing
&& count
< PAGE_SIZE
)
979 clear_highpage(page
);
982 if (cs
->write
&& cs
->pipebufs
&& page
) {
983 return fuse_ref_page(cs
, page
, offset
, count
);
984 } else if (!cs
->len
) {
985 if (cs
->move_pages
&& page
&&
986 offset
== 0 && count
== PAGE_SIZE
) {
987 err
= fuse_try_move_page(cs
, pagep
);
991 err
= fuse_copy_fill(cs
);
997 void *mapaddr
= kmap_atomic(page
);
998 void *buf
= mapaddr
+ offset
;
999 offset
+= fuse_copy_do(cs
, &buf
, &count
);
1000 kunmap_atomic(mapaddr
);
1002 offset
+= fuse_copy_do(cs
, NULL
, &count
);
1004 if (page
&& !cs
->write
)
1005 flush_dcache_page(page
);
1009 /* Copy pages in the request to/from userspace buffer */
1010 static int fuse_copy_pages(struct fuse_copy_state
*cs
, unsigned nbytes
,
1014 struct fuse_req
*req
= cs
->req
;
1016 for (i
= 0; i
< req
->num_pages
&& (nbytes
|| zeroing
); i
++) {
1018 unsigned offset
= req
->page_descs
[i
].offset
;
1019 unsigned count
= min(nbytes
, req
->page_descs
[i
].length
);
1021 err
= fuse_copy_page(cs
, &req
->pages
[i
], offset
, count
,
1031 /* Copy a single argument in the request to/from userspace buffer */
1032 static int fuse_copy_one(struct fuse_copy_state
*cs
, void *val
, unsigned size
)
1036 int err
= fuse_copy_fill(cs
);
1040 fuse_copy_do(cs
, &val
, &size
);
1045 /* Copy request arguments to/from userspace buffer */
1046 static int fuse_copy_args(struct fuse_copy_state
*cs
, unsigned numargs
,
1047 unsigned argpages
, struct fuse_arg
*args
,
1053 for (i
= 0; !err
&& i
< numargs
; i
++) {
1054 struct fuse_arg
*arg
= &args
[i
];
1055 if (i
== numargs
- 1 && argpages
)
1056 err
= fuse_copy_pages(cs
, arg
->size
, zeroing
);
1058 err
= fuse_copy_one(cs
, arg
->value
, arg
->size
);
1063 static int forget_pending(struct fuse_iqueue
*fiq
)
1065 return fiq
->forget_list_head
.next
!= NULL
;
1068 static int request_pending(struct fuse_iqueue
*fiq
)
1070 return !list_empty(&fiq
->pending
) || !list_empty(&fiq
->interrupts
) ||
1071 forget_pending(fiq
);
1075 * Transfer an interrupt request to userspace
1077 * Unlike other requests this is assembled on demand, without a need
1078 * to allocate a separate fuse_req structure.
1080 * Called with fiq->waitq.lock held, releases it
1082 static int fuse_read_interrupt(struct fuse_iqueue
*fiq
,
1083 struct fuse_copy_state
*cs
,
1084 size_t nbytes
, struct fuse_req
*req
)
1085 __releases(fiq
->waitq
.lock
)
1087 struct fuse_in_header ih
;
1088 struct fuse_interrupt_in arg
;
1089 unsigned reqsize
= sizeof(ih
) + sizeof(arg
);
1092 list_del_init(&req
->intr_entry
);
1093 req
->intr_unique
= fuse_get_unique(fiq
);
1094 memset(&ih
, 0, sizeof(ih
));
1095 memset(&arg
, 0, sizeof(arg
));
1097 ih
.opcode
= FUSE_INTERRUPT
;
1098 ih
.unique
= req
->intr_unique
;
1099 arg
.unique
= req
->in
.h
.unique
;
1101 spin_unlock(&fiq
->waitq
.lock
);
1102 if (nbytes
< reqsize
)
1105 err
= fuse_copy_one(cs
, &ih
, sizeof(ih
));
1107 err
= fuse_copy_one(cs
, &arg
, sizeof(arg
));
1108 fuse_copy_finish(cs
);
1110 return err
? err
: reqsize
;
1113 static struct fuse_forget_link
*dequeue_forget(struct fuse_iqueue
*fiq
,
1117 struct fuse_forget_link
*head
= fiq
->forget_list_head
.next
;
1118 struct fuse_forget_link
**newhead
= &head
;
1121 for (count
= 0; *newhead
!= NULL
&& count
< max
; count
++)
1122 newhead
= &(*newhead
)->next
;
1124 fiq
->forget_list_head
.next
= *newhead
;
1126 if (fiq
->forget_list_head
.next
== NULL
)
1127 fiq
->forget_list_tail
= &fiq
->forget_list_head
;
1135 static int fuse_read_single_forget(struct fuse_iqueue
*fiq
,
1136 struct fuse_copy_state
*cs
,
1138 __releases(fiq
->waitq
.lock
)
1141 struct fuse_forget_link
*forget
= dequeue_forget(fiq
, 1, NULL
);
1142 struct fuse_forget_in arg
= {
1143 .nlookup
= forget
->forget_one
.nlookup
,
1145 struct fuse_in_header ih
= {
1146 .opcode
= FUSE_FORGET
,
1147 .nodeid
= forget
->forget_one
.nodeid
,
1148 .unique
= fuse_get_unique(fiq
),
1149 .len
= sizeof(ih
) + sizeof(arg
),
1152 spin_unlock(&fiq
->waitq
.lock
);
1154 if (nbytes
< ih
.len
)
1157 err
= fuse_copy_one(cs
, &ih
, sizeof(ih
));
1159 err
= fuse_copy_one(cs
, &arg
, sizeof(arg
));
1160 fuse_copy_finish(cs
);
1168 static int fuse_read_batch_forget(struct fuse_iqueue
*fiq
,
1169 struct fuse_copy_state
*cs
, size_t nbytes
)
1170 __releases(fiq
->waitq
.lock
)
1173 unsigned max_forgets
;
1175 struct fuse_forget_link
*head
;
1176 struct fuse_batch_forget_in arg
= { .count
= 0 };
1177 struct fuse_in_header ih
= {
1178 .opcode
= FUSE_BATCH_FORGET
,
1179 .unique
= fuse_get_unique(fiq
),
1180 .len
= sizeof(ih
) + sizeof(arg
),
1183 if (nbytes
< ih
.len
) {
1184 spin_unlock(&fiq
->waitq
.lock
);
1188 max_forgets
= (nbytes
- ih
.len
) / sizeof(struct fuse_forget_one
);
1189 head
= dequeue_forget(fiq
, max_forgets
, &count
);
1190 spin_unlock(&fiq
->waitq
.lock
);
1193 ih
.len
+= count
* sizeof(struct fuse_forget_one
);
1194 err
= fuse_copy_one(cs
, &ih
, sizeof(ih
));
1196 err
= fuse_copy_one(cs
, &arg
, sizeof(arg
));
1199 struct fuse_forget_link
*forget
= head
;
1202 err
= fuse_copy_one(cs
, &forget
->forget_one
,
1203 sizeof(forget
->forget_one
));
1205 head
= forget
->next
;
1209 fuse_copy_finish(cs
);
1217 static int fuse_read_forget(struct fuse_conn
*fc
, struct fuse_iqueue
*fiq
,
1218 struct fuse_copy_state
*cs
,
1220 __releases(fiq
->waitq
.lock
)
1222 if (fc
->minor
< 16 || fiq
->forget_list_head
.next
->next
== NULL
)
1223 return fuse_read_single_forget(fiq
, cs
, nbytes
);
1225 return fuse_read_batch_forget(fiq
, cs
, nbytes
);
1229 * Read a single request into the userspace filesystem's buffer. This
1230 * function waits until a request is available, then removes it from
1231 * the pending list and copies request data to userspace buffer. If
1232 * no reply is needed (FORGET) or request has been aborted or there
1233 * was an error during the copying then it's finished by calling
1234 * request_end(). Otherwise add it to the processing list, and set
1237 static ssize_t
fuse_dev_do_read(struct fuse_conn
*fc
, struct file
*file
,
1238 struct fuse_copy_state
*cs
, size_t nbytes
)
1241 struct fuse_iqueue
*fiq
= &fc
->iq
;
1242 struct fuse_pqueue
*fpq
= &fc
->pq
;
1243 struct fuse_req
*req
;
1248 spin_lock(&fiq
->waitq
.lock
);
1250 if ((file
->f_flags
& O_NONBLOCK
) && fiq
->connected
&&
1251 !request_pending(fiq
))
1254 err
= wait_event_interruptible_exclusive_locked(fiq
->waitq
,
1255 !fiq
->connected
|| request_pending(fiq
));
1260 if (!fiq
->connected
)
1263 if (!list_empty(&fiq
->interrupts
)) {
1264 req
= list_entry(fiq
->interrupts
.next
, struct fuse_req
,
1266 return fuse_read_interrupt(fiq
, cs
, nbytes
, req
);
1269 if (forget_pending(fiq
)) {
1270 if (list_empty(&fiq
->pending
) || fiq
->forget_batch
-- > 0)
1271 return fuse_read_forget(fc
, fiq
, cs
, nbytes
);
1273 if (fiq
->forget_batch
<= -8)
1274 fiq
->forget_batch
= 16;
1277 req
= list_entry(fiq
->pending
.next
, struct fuse_req
, list
);
1278 clear_bit(FR_PENDING
, &req
->flags
);
1279 list_del_init(&req
->list
);
1280 spin_unlock(&fiq
->waitq
.lock
);
1282 spin_lock(&fc
->lock
);
1284 reqsize
= in
->h
.len
;
1285 /* If request is too large, reply with an error and restart the read */
1286 if (nbytes
< reqsize
) {
1287 req
->out
.h
.error
= -EIO
;
1288 /* SETXATTR is special, since it may contain too large data */
1289 if (in
->h
.opcode
== FUSE_SETXATTR
)
1290 req
->out
.h
.error
= -E2BIG
;
1291 request_end(fc
, req
);
1294 spin_lock(&fpq
->lock
);
1295 list_add(&req
->list
, &fpq
->io
);
1296 spin_unlock(&fpq
->lock
);
1297 spin_unlock(&fc
->lock
);
1299 err
= fuse_copy_one(cs
, &in
->h
, sizeof(in
->h
));
1301 err
= fuse_copy_args(cs
, in
->numargs
, in
->argpages
,
1302 (struct fuse_arg
*) in
->args
, 0);
1303 fuse_copy_finish(cs
);
1304 spin_lock(&fc
->lock
);
1305 spin_lock(&fpq
->lock
);
1306 clear_bit(FR_LOCKED
, &req
->flags
);
1307 if (!fpq
->connected
) {
1312 req
->out
.h
.error
= -EIO
;
1315 if (!test_bit(FR_ISREPLY
, &req
->flags
)) {
1319 list_move_tail(&req
->list
, &fpq
->processing
);
1320 spin_unlock(&fpq
->lock
);
1321 set_bit(FR_SENT
, &req
->flags
);
1322 /* matches barrier in request_wait_answer() */
1323 smp_mb__after_atomic();
1324 if (test_bit(FR_INTERRUPTED
, &req
->flags
))
1325 queue_interrupt(fiq
, req
);
1326 spin_unlock(&fc
->lock
);
1331 if (!test_bit(FR_PRIVATE
, &req
->flags
))
1332 list_del_init(&req
->list
);
1333 spin_unlock(&fpq
->lock
);
1334 request_end(fc
, req
);
1338 spin_unlock(&fiq
->waitq
.lock
);
1342 static int fuse_dev_open(struct inode
*inode
, struct file
*file
)
1345 * The fuse device's file's private_data is used to hold
1346 * the fuse_conn(ection) when it is mounted, and is used to
1347 * keep track of whether the file has been mounted already.
1349 file
->private_data
= NULL
;
1353 static ssize_t
fuse_dev_read(struct kiocb
*iocb
, struct iov_iter
*to
)
1355 struct fuse_copy_state cs
;
1356 struct file
*file
= iocb
->ki_filp
;
1357 struct fuse_conn
*fc
= fuse_get_conn(file
);
1361 if (!iter_is_iovec(to
))
1364 fuse_copy_init(&cs
, 1, to
);
1366 return fuse_dev_do_read(fc
, file
, &cs
, iov_iter_count(to
));
1369 static ssize_t
fuse_dev_splice_read(struct file
*in
, loff_t
*ppos
,
1370 struct pipe_inode_info
*pipe
,
1371 size_t len
, unsigned int flags
)
1376 struct pipe_buffer
*bufs
;
1377 struct fuse_copy_state cs
;
1378 struct fuse_conn
*fc
= fuse_get_conn(in
);
1382 bufs
= kmalloc(pipe
->buffers
* sizeof(struct pipe_buffer
), GFP_KERNEL
);
1386 fuse_copy_init(&cs
, 1, NULL
);
1389 ret
= fuse_dev_do_read(fc
, in
, &cs
, len
);
1396 if (!pipe
->readers
) {
1397 send_sig(SIGPIPE
, current
, 0);
1403 if (pipe
->nrbufs
+ cs
.nr_segs
> pipe
->buffers
) {
1408 while (page_nr
< cs
.nr_segs
) {
1409 int newbuf
= (pipe
->curbuf
+ pipe
->nrbufs
) & (pipe
->buffers
- 1);
1410 struct pipe_buffer
*buf
= pipe
->bufs
+ newbuf
;
1412 buf
->page
= bufs
[page_nr
].page
;
1413 buf
->offset
= bufs
[page_nr
].offset
;
1414 buf
->len
= bufs
[page_nr
].len
;
1416 * Need to be careful about this. Having buf->ops in module
1417 * code can Oops if the buffer persists after module unload.
1419 buf
->ops
= &nosteal_pipe_buf_ops
;
1434 if (waitqueue_active(&pipe
->wait
))
1435 wake_up_interruptible(&pipe
->wait
);
1436 kill_fasync(&pipe
->fasync_readers
, SIGIO
, POLL_IN
);
1440 for (; page_nr
< cs
.nr_segs
; page_nr
++)
1441 page_cache_release(bufs
[page_nr
].page
);
1447 static int fuse_notify_poll(struct fuse_conn
*fc
, unsigned int size
,
1448 struct fuse_copy_state
*cs
)
1450 struct fuse_notify_poll_wakeup_out outarg
;
1453 if (size
!= sizeof(outarg
))
1456 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1460 fuse_copy_finish(cs
);
1461 return fuse_notify_poll_wakeup(fc
, &outarg
);
1464 fuse_copy_finish(cs
);
1468 static int fuse_notify_inval_inode(struct fuse_conn
*fc
, unsigned int size
,
1469 struct fuse_copy_state
*cs
)
1471 struct fuse_notify_inval_inode_out outarg
;
1474 if (size
!= sizeof(outarg
))
1477 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1480 fuse_copy_finish(cs
);
1482 down_read(&fc
->killsb
);
1485 err
= fuse_reverse_inval_inode(fc
->sb
, outarg
.ino
,
1486 outarg
.off
, outarg
.len
);
1488 up_read(&fc
->killsb
);
1492 fuse_copy_finish(cs
);
1496 static int fuse_notify_inval_entry(struct fuse_conn
*fc
, unsigned int size
,
1497 struct fuse_copy_state
*cs
)
1499 struct fuse_notify_inval_entry_out outarg
;
1504 buf
= kzalloc(FUSE_NAME_MAX
+ 1, GFP_KERNEL
);
1509 if (size
< sizeof(outarg
))
1512 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1516 err
= -ENAMETOOLONG
;
1517 if (outarg
.namelen
> FUSE_NAME_MAX
)
1521 if (size
!= sizeof(outarg
) + outarg
.namelen
+ 1)
1525 name
.len
= outarg
.namelen
;
1526 err
= fuse_copy_one(cs
, buf
, outarg
.namelen
+ 1);
1529 fuse_copy_finish(cs
);
1530 buf
[outarg
.namelen
] = 0;
1531 name
.hash
= full_name_hash(name
.name
, name
.len
);
1533 down_read(&fc
->killsb
);
1536 err
= fuse_reverse_inval_entry(fc
->sb
, outarg
.parent
, 0, &name
);
1537 up_read(&fc
->killsb
);
1543 fuse_copy_finish(cs
);
1547 static int fuse_notify_delete(struct fuse_conn
*fc
, unsigned int size
,
1548 struct fuse_copy_state
*cs
)
1550 struct fuse_notify_delete_out outarg
;
1555 buf
= kzalloc(FUSE_NAME_MAX
+ 1, GFP_KERNEL
);
1560 if (size
< sizeof(outarg
))
1563 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1567 err
= -ENAMETOOLONG
;
1568 if (outarg
.namelen
> FUSE_NAME_MAX
)
1572 if (size
!= sizeof(outarg
) + outarg
.namelen
+ 1)
1576 name
.len
= outarg
.namelen
;
1577 err
= fuse_copy_one(cs
, buf
, outarg
.namelen
+ 1);
1580 fuse_copy_finish(cs
);
1581 buf
[outarg
.namelen
] = 0;
1582 name
.hash
= full_name_hash(name
.name
, name
.len
);
1584 down_read(&fc
->killsb
);
1587 err
= fuse_reverse_inval_entry(fc
->sb
, outarg
.parent
,
1588 outarg
.child
, &name
);
1589 up_read(&fc
->killsb
);
1595 fuse_copy_finish(cs
);
1599 static int fuse_notify_store(struct fuse_conn
*fc
, unsigned int size
,
1600 struct fuse_copy_state
*cs
)
1602 struct fuse_notify_store_out outarg
;
1603 struct inode
*inode
;
1604 struct address_space
*mapping
;
1608 unsigned int offset
;
1614 if (size
< sizeof(outarg
))
1617 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1622 if (size
- sizeof(outarg
) != outarg
.size
)
1625 nodeid
= outarg
.nodeid
;
1627 down_read(&fc
->killsb
);
1633 inode
= ilookup5(fc
->sb
, nodeid
, fuse_inode_eq
, &nodeid
);
1637 mapping
= inode
->i_mapping
;
1638 index
= outarg
.offset
>> PAGE_CACHE_SHIFT
;
1639 offset
= outarg
.offset
& ~PAGE_CACHE_MASK
;
1640 file_size
= i_size_read(inode
);
1641 end
= outarg
.offset
+ outarg
.size
;
1642 if (end
> file_size
) {
1644 fuse_write_update_size(inode
, file_size
);
1650 unsigned int this_num
;
1653 page
= find_or_create_page(mapping
, index
,
1654 mapping_gfp_mask(mapping
));
1658 this_num
= min_t(unsigned, num
, PAGE_CACHE_SIZE
- offset
);
1659 err
= fuse_copy_page(cs
, &page
, offset
, this_num
, 0);
1660 if (!err
&& offset
== 0 &&
1661 (this_num
== PAGE_CACHE_SIZE
|| file_size
== end
))
1662 SetPageUptodate(page
);
1664 page_cache_release(page
);
1679 up_read(&fc
->killsb
);
1681 fuse_copy_finish(cs
);
1685 static void fuse_retrieve_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
1687 release_pages(req
->pages
, req
->num_pages
, false);
1690 static int fuse_retrieve(struct fuse_conn
*fc
, struct inode
*inode
,
1691 struct fuse_notify_retrieve_out
*outarg
)
1694 struct address_space
*mapping
= inode
->i_mapping
;
1695 struct fuse_req
*req
;
1699 unsigned int offset
;
1700 size_t total_len
= 0;
1703 offset
= outarg
->offset
& ~PAGE_CACHE_MASK
;
1704 file_size
= i_size_read(inode
);
1707 if (outarg
->offset
> file_size
)
1709 else if (outarg
->offset
+ num
> file_size
)
1710 num
= file_size
- outarg
->offset
;
1712 num_pages
= (num
+ offset
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1713 num_pages
= min(num_pages
, FUSE_MAX_PAGES_PER_REQ
);
1715 req
= fuse_get_req(fc
, num_pages
);
1717 return PTR_ERR(req
);
1719 req
->in
.h
.opcode
= FUSE_NOTIFY_REPLY
;
1720 req
->in
.h
.nodeid
= outarg
->nodeid
;
1721 req
->in
.numargs
= 2;
1722 req
->in
.argpages
= 1;
1723 req
->page_descs
[0].offset
= offset
;
1724 req
->end
= fuse_retrieve_end
;
1726 index
= outarg
->offset
>> PAGE_CACHE_SHIFT
;
1728 while (num
&& req
->num_pages
< num_pages
) {
1730 unsigned int this_num
;
1732 page
= find_get_page(mapping
, index
);
1736 this_num
= min_t(unsigned, num
, PAGE_CACHE_SIZE
- offset
);
1737 req
->pages
[req
->num_pages
] = page
;
1738 req
->page_descs
[req
->num_pages
].length
= this_num
;
1743 total_len
+= this_num
;
1746 req
->misc
.retrieve_in
.offset
= outarg
->offset
;
1747 req
->misc
.retrieve_in
.size
= total_len
;
1748 req
->in
.args
[0].size
= sizeof(req
->misc
.retrieve_in
);
1749 req
->in
.args
[0].value
= &req
->misc
.retrieve_in
;
1750 req
->in
.args
[1].size
= total_len
;
1752 err
= fuse_request_send_notify_reply(fc
, req
, outarg
->notify_unique
);
1754 fuse_retrieve_end(fc
, req
);
1759 static int fuse_notify_retrieve(struct fuse_conn
*fc
, unsigned int size
,
1760 struct fuse_copy_state
*cs
)
1762 struct fuse_notify_retrieve_out outarg
;
1763 struct inode
*inode
;
1767 if (size
!= sizeof(outarg
))
1770 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1774 fuse_copy_finish(cs
);
1776 down_read(&fc
->killsb
);
1779 u64 nodeid
= outarg
.nodeid
;
1781 inode
= ilookup5(fc
->sb
, nodeid
, fuse_inode_eq
, &nodeid
);
1783 err
= fuse_retrieve(fc
, inode
, &outarg
);
1787 up_read(&fc
->killsb
);
1792 fuse_copy_finish(cs
);
1796 static int fuse_notify(struct fuse_conn
*fc
, enum fuse_notify_code code
,
1797 unsigned int size
, struct fuse_copy_state
*cs
)
1799 /* Don't try to move pages (yet) */
1803 case FUSE_NOTIFY_POLL
:
1804 return fuse_notify_poll(fc
, size
, cs
);
1806 case FUSE_NOTIFY_INVAL_INODE
:
1807 return fuse_notify_inval_inode(fc
, size
, cs
);
1809 case FUSE_NOTIFY_INVAL_ENTRY
:
1810 return fuse_notify_inval_entry(fc
, size
, cs
);
1812 case FUSE_NOTIFY_STORE
:
1813 return fuse_notify_store(fc
, size
, cs
);
1815 case FUSE_NOTIFY_RETRIEVE
:
1816 return fuse_notify_retrieve(fc
, size
, cs
);
1818 case FUSE_NOTIFY_DELETE
:
1819 return fuse_notify_delete(fc
, size
, cs
);
1822 fuse_copy_finish(cs
);
1827 /* Look up request on processing list by unique ID */
1828 static struct fuse_req
*request_find(struct fuse_pqueue
*fpq
, u64 unique
)
1830 struct fuse_req
*req
;
1832 list_for_each_entry(req
, &fpq
->processing
, list
) {
1833 if (req
->in
.h
.unique
== unique
|| req
->intr_unique
== unique
)
1839 static int copy_out_args(struct fuse_copy_state
*cs
, struct fuse_out
*out
,
1842 unsigned reqsize
= sizeof(struct fuse_out_header
);
1845 return nbytes
!= reqsize
? -EINVAL
: 0;
1847 reqsize
+= len_args(out
->numargs
, out
->args
);
1849 if (reqsize
< nbytes
|| (reqsize
> nbytes
&& !out
->argvar
))
1851 else if (reqsize
> nbytes
) {
1852 struct fuse_arg
*lastarg
= &out
->args
[out
->numargs
-1];
1853 unsigned diffsize
= reqsize
- nbytes
;
1854 if (diffsize
> lastarg
->size
)
1856 lastarg
->size
-= diffsize
;
1858 return fuse_copy_args(cs
, out
->numargs
, out
->argpages
, out
->args
,
1863 * Write a single reply to a request. First the header is copied from
1864 * the write buffer. The request is then searched on the processing
1865 * list by the unique ID found in the header. If found, then remove
1866 * it from the list and copy the rest of the buffer to the request.
1867 * The request is finished by calling request_end()
1869 static ssize_t
fuse_dev_do_write(struct fuse_conn
*fc
,
1870 struct fuse_copy_state
*cs
, size_t nbytes
)
1873 struct fuse_pqueue
*fpq
= &fc
->pq
;
1874 struct fuse_req
*req
;
1875 struct fuse_out_header oh
;
1877 if (nbytes
< sizeof(struct fuse_out_header
))
1880 err
= fuse_copy_one(cs
, &oh
, sizeof(oh
));
1885 if (oh
.len
!= nbytes
)
1889 * Zero oh.unique indicates unsolicited notification message
1890 * and error contains notification code.
1893 err
= fuse_notify(fc
, oh
.error
, nbytes
- sizeof(oh
), cs
);
1894 return err
? err
: nbytes
;
1898 if (oh
.error
<= -1000 || oh
.error
> 0)
1901 spin_lock(&fc
->lock
);
1902 spin_lock(&fpq
->lock
);
1904 if (!fpq
->connected
)
1907 req
= request_find(fpq
, oh
.unique
);
1911 /* Is it an interrupt reply? */
1912 if (req
->intr_unique
== oh
.unique
) {
1913 spin_unlock(&fpq
->lock
);
1916 if (nbytes
!= sizeof(struct fuse_out_header
))
1919 if (oh
.error
== -ENOSYS
)
1920 fc
->no_interrupt
= 1;
1921 else if (oh
.error
== -EAGAIN
)
1922 queue_interrupt(&fc
->iq
, req
);
1924 spin_unlock(&fc
->lock
);
1925 fuse_copy_finish(cs
);
1929 clear_bit(FR_SENT
, &req
->flags
);
1930 list_move(&req
->list
, &fpq
->io
);
1932 set_bit(FR_LOCKED
, &req
->flags
);
1933 spin_unlock(&fpq
->lock
);
1935 if (!req
->out
.page_replace
)
1937 spin_unlock(&fc
->lock
);
1939 err
= copy_out_args(cs
, &req
->out
, nbytes
);
1940 fuse_copy_finish(cs
);
1942 spin_lock(&fc
->lock
);
1943 spin_lock(&fpq
->lock
);
1944 clear_bit(FR_LOCKED
, &req
->flags
);
1945 if (!fpq
->connected
)
1948 req
->out
.h
.error
= -EIO
;
1949 if (!test_bit(FR_PRIVATE
, &req
->flags
))
1950 list_del_init(&req
->list
);
1951 spin_unlock(&fpq
->lock
);
1952 request_end(fc
, req
);
1954 return err
? err
: nbytes
;
1957 spin_unlock(&fpq
->lock
);
1959 spin_unlock(&fc
->lock
);
1961 fuse_copy_finish(cs
);
1965 static ssize_t
fuse_dev_write(struct kiocb
*iocb
, struct iov_iter
*from
)
1967 struct fuse_copy_state cs
;
1968 struct fuse_conn
*fc
= fuse_get_conn(iocb
->ki_filp
);
1972 if (!iter_is_iovec(from
))
1975 fuse_copy_init(&cs
, 0, from
);
1977 return fuse_dev_do_write(fc
, &cs
, iov_iter_count(from
));
1980 static ssize_t
fuse_dev_splice_write(struct pipe_inode_info
*pipe
,
1981 struct file
*out
, loff_t
*ppos
,
1982 size_t len
, unsigned int flags
)
1986 struct pipe_buffer
*bufs
;
1987 struct fuse_copy_state cs
;
1988 struct fuse_conn
*fc
;
1992 fc
= fuse_get_conn(out
);
1996 bufs
= kmalloc(pipe
->buffers
* sizeof(struct pipe_buffer
), GFP_KERNEL
);
2003 for (idx
= 0; idx
< pipe
->nrbufs
&& rem
< len
; idx
++)
2004 rem
+= pipe
->bufs
[(pipe
->curbuf
+ idx
) & (pipe
->buffers
- 1)].len
;
2014 struct pipe_buffer
*ibuf
;
2015 struct pipe_buffer
*obuf
;
2017 BUG_ON(nbuf
>= pipe
->buffers
);
2018 BUG_ON(!pipe
->nrbufs
);
2019 ibuf
= &pipe
->bufs
[pipe
->curbuf
];
2022 if (rem
>= ibuf
->len
) {
2025 pipe
->curbuf
= (pipe
->curbuf
+ 1) & (pipe
->buffers
- 1);
2028 ibuf
->ops
->get(pipe
, ibuf
);
2030 obuf
->flags
&= ~PIPE_BUF_FLAG_GIFT
;
2032 ibuf
->offset
+= obuf
->len
;
2033 ibuf
->len
-= obuf
->len
;
2040 fuse_copy_init(&cs
, 0, NULL
);
2045 if (flags
& SPLICE_F_MOVE
)
2048 ret
= fuse_dev_do_write(fc
, &cs
, len
);
2050 for (idx
= 0; idx
< nbuf
; idx
++) {
2051 struct pipe_buffer
*buf
= &bufs
[idx
];
2052 buf
->ops
->release(pipe
, buf
);
2059 static unsigned fuse_dev_poll(struct file
*file
, poll_table
*wait
)
2061 unsigned mask
= POLLOUT
| POLLWRNORM
;
2062 struct fuse_iqueue
*fiq
;
2063 struct fuse_conn
*fc
= fuse_get_conn(file
);
2068 poll_wait(file
, &fiq
->waitq
, wait
);
2070 spin_lock(&fiq
->waitq
.lock
);
2071 if (!fiq
->connected
)
2073 else if (request_pending(fiq
))
2074 mask
|= POLLIN
| POLLRDNORM
;
2075 spin_unlock(&fiq
->waitq
.lock
);
2081 * Abort all requests on the given list (pending or processing)
2083 * This function releases and reacquires fc->lock
2085 static void end_requests(struct fuse_conn
*fc
, struct list_head
*head
)
2086 __releases(fc
->lock
)
2087 __acquires(fc
->lock
)
2089 while (!list_empty(head
)) {
2090 struct fuse_req
*req
;
2091 req
= list_entry(head
->next
, struct fuse_req
, list
);
2092 req
->out
.h
.error
= -ECONNABORTED
;
2093 clear_bit(FR_PENDING
, &req
->flags
);
2094 clear_bit(FR_SENT
, &req
->flags
);
2095 list_del_init(&req
->list
);
2096 request_end(fc
, req
);
2097 spin_lock(&fc
->lock
);
2101 static void end_polls(struct fuse_conn
*fc
)
2105 p
= rb_first(&fc
->polled_files
);
2108 struct fuse_file
*ff
;
2109 ff
= rb_entry(p
, struct fuse_file
, polled_node
);
2110 wake_up_interruptible_all(&ff
->poll_wait
);
2117 * Abort all requests.
2119 * Emergency exit in case of a malicious or accidental deadlock, or just a hung
2122 * The same effect is usually achievable through killing the filesystem daemon
2123 * and all users of the filesystem. The exception is the combination of an
2124 * asynchronous request and the tricky deadlock (see
2125 * Documentation/filesystems/fuse.txt).
2127 * Aborting requests under I/O goes as follows: 1: Separate out unlocked
2128 * requests, they should be finished off immediately. Locked requests will be
2129 * finished after unlock; see unlock_request(). 2: Finish off the unlocked
2130 * requests. It is possible that some request will finish before we can. This
2131 * is OK, the request will in that case be removed from the list before we touch
2134 void fuse_abort_conn(struct fuse_conn
*fc
)
2136 struct fuse_iqueue
*fiq
= &fc
->iq
;
2137 struct fuse_pqueue
*fpq
= &fc
->pq
;
2139 spin_lock(&fc
->lock
);
2140 if (fc
->connected
) {
2141 struct fuse_req
*req
, *next
;
2147 fuse_set_initialized(fc
);
2148 spin_lock(&fpq
->lock
);
2150 list_for_each_entry_safe(req
, next
, &fpq
->io
, list
) {
2151 req
->out
.h
.error
= -ECONNABORTED
;
2152 spin_lock(&req
->waitq
.lock
);
2153 set_bit(FR_ABORTED
, &req
->flags
);
2154 if (!test_bit(FR_LOCKED
, &req
->flags
)) {
2155 set_bit(FR_PRIVATE
, &req
->flags
);
2156 list_move(&req
->list
, &to_end1
);
2158 spin_unlock(&req
->waitq
.lock
);
2160 list_splice_init(&fpq
->processing
, &to_end2
);
2161 spin_unlock(&fpq
->lock
);
2162 fc
->max_background
= UINT_MAX
;
2165 spin_lock(&fiq
->waitq
.lock
);
2167 list_splice_init(&fiq
->pending
, &to_end2
);
2168 while (forget_pending(fiq
))
2169 kfree(dequeue_forget(fiq
, 1, NULL
));
2170 wake_up_all_locked(&fiq
->waitq
);
2171 spin_unlock(&fiq
->waitq
.lock
);
2172 kill_fasync(&fiq
->fasync
, SIGIO
, POLL_IN
);
2174 while (!list_empty(&to_end1
)) {
2175 req
= list_first_entry(&to_end1
, struct fuse_req
, list
);
2176 __fuse_get_request(req
);
2177 list_del_init(&req
->list
);
2178 request_end(fc
, req
);
2179 spin_lock(&fc
->lock
);
2181 end_requests(fc
, &to_end2
);
2183 wake_up_all(&fc
->blocked_waitq
);
2185 spin_unlock(&fc
->lock
);
2187 EXPORT_SYMBOL_GPL(fuse_abort_conn
);
2189 int fuse_dev_release(struct inode
*inode
, struct file
*file
)
2191 struct fuse_conn
*fc
= fuse_get_conn(file
);
2193 WARN_ON(!list_empty(&fc
->pq
.io
));
2194 WARN_ON(fc
->iq
.fasync
!= NULL
);
2195 fuse_abort_conn(fc
);
2201 EXPORT_SYMBOL_GPL(fuse_dev_release
);
2203 static int fuse_dev_fasync(int fd
, struct file
*file
, int on
)
2205 struct fuse_conn
*fc
= fuse_get_conn(file
);
2209 /* No locking - fasync_helper does its own locking */
2210 return fasync_helper(fd
, file
, on
, &fc
->iq
.fasync
);
2213 const struct file_operations fuse_dev_operations
= {
2214 .owner
= THIS_MODULE
,
2215 .open
= fuse_dev_open
,
2216 .llseek
= no_llseek
,
2217 .read_iter
= fuse_dev_read
,
2218 .splice_read
= fuse_dev_splice_read
,
2219 .write_iter
= fuse_dev_write
,
2220 .splice_write
= fuse_dev_splice_write
,
2221 .poll
= fuse_dev_poll
,
2222 .release
= fuse_dev_release
,
2223 .fasync
= fuse_dev_fasync
,
2225 EXPORT_SYMBOL_GPL(fuse_dev_operations
);
2227 static struct miscdevice fuse_miscdevice
= {
2228 .minor
= FUSE_MINOR
,
2230 .fops
= &fuse_dev_operations
,
2233 int __init
fuse_dev_init(void)
2236 fuse_req_cachep
= kmem_cache_create("fuse_request",
2237 sizeof(struct fuse_req
),
2239 if (!fuse_req_cachep
)
2242 err
= misc_register(&fuse_miscdevice
);
2244 goto out_cache_clean
;
2249 kmem_cache_destroy(fuse_req_cachep
);
2254 void fuse_dev_cleanup(void)
2256 misc_deregister(&fuse_miscdevice
);
2257 kmem_cache_destroy(fuse_req_cachep
);