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/sched/signal.h>
15 #include <linux/uio.h>
16 #include <linux/miscdevice.h>
17 #include <linux/pagemap.h>
18 #include <linux/file.h>
19 #include <linux/slab.h>
20 #include <linux/pipe_fs_i.h>
21 #include <linux/swap.h>
22 #include <linux/splice.h>
23 #include <linux/sched.h>
25 MODULE_ALIAS_MISCDEV(FUSE_MINOR
);
26 MODULE_ALIAS("devname:fuse");
28 static struct kmem_cache
*fuse_req_cachep
;
30 static struct fuse_dev
*fuse_get_dev(struct file
*file
)
33 * Lockless access is OK, because file->private data is set
34 * once during mount and is valid until the file is released.
36 return ACCESS_ONCE(file
->private_data
);
39 static void fuse_request_init(struct fuse_req
*req
, struct page
**pages
,
40 struct fuse_page_desc
*page_descs
,
43 memset(req
, 0, sizeof(*req
));
44 memset(pages
, 0, sizeof(*pages
) * npages
);
45 memset(page_descs
, 0, sizeof(*page_descs
) * npages
);
46 INIT_LIST_HEAD(&req
->list
);
47 INIT_LIST_HEAD(&req
->intr_entry
);
48 init_waitqueue_head(&req
->waitq
);
49 refcount_set(&req
->count
, 1);
51 req
->page_descs
= page_descs
;
52 req
->max_pages
= npages
;
53 __set_bit(FR_PENDING
, &req
->flags
);
56 static struct fuse_req
*__fuse_request_alloc(unsigned npages
, gfp_t flags
)
58 struct fuse_req
*req
= kmem_cache_alloc(fuse_req_cachep
, flags
);
61 struct fuse_page_desc
*page_descs
;
63 if (npages
<= FUSE_REQ_INLINE_PAGES
) {
64 pages
= req
->inline_pages
;
65 page_descs
= req
->inline_page_descs
;
67 pages
= kmalloc(sizeof(struct page
*) * npages
, flags
);
68 page_descs
= kmalloc(sizeof(struct fuse_page_desc
) *
72 if (!pages
|| !page_descs
) {
75 kmem_cache_free(fuse_req_cachep
, req
);
79 fuse_request_init(req
, pages
, page_descs
, npages
);
84 struct fuse_req
*fuse_request_alloc(unsigned npages
)
86 return __fuse_request_alloc(npages
, GFP_KERNEL
);
88 EXPORT_SYMBOL_GPL(fuse_request_alloc
);
90 struct fuse_req
*fuse_request_alloc_nofs(unsigned npages
)
92 return __fuse_request_alloc(npages
, GFP_NOFS
);
95 void fuse_request_free(struct fuse_req
*req
)
97 if (req
->pages
!= req
->inline_pages
) {
99 kfree(req
->page_descs
);
101 kmem_cache_free(fuse_req_cachep
, req
);
104 void __fuse_get_request(struct fuse_req
*req
)
106 refcount_inc(&req
->count
);
109 /* Must be called with > 1 refcount */
110 static void __fuse_put_request(struct fuse_req
*req
)
112 refcount_dec(&req
->count
);
115 static void fuse_req_init_context(struct fuse_conn
*fc
, struct fuse_req
*req
)
117 req
->in
.h
.uid
= from_kuid_munged(&init_user_ns
, current_fsuid());
118 req
->in
.h
.gid
= from_kgid_munged(&init_user_ns
, current_fsgid());
119 req
->in
.h
.pid
= pid_nr_ns(task_pid(current
), fc
->pid_ns
);
122 void fuse_set_initialized(struct fuse_conn
*fc
)
124 /* Make sure stores before this are seen on another CPU */
129 static bool fuse_block_alloc(struct fuse_conn
*fc
, bool for_background
)
131 return !fc
->initialized
|| (for_background
&& fc
->blocked
);
134 static struct fuse_req
*__fuse_get_req(struct fuse_conn
*fc
, unsigned npages
,
137 struct fuse_req
*req
;
139 atomic_inc(&fc
->num_waiting
);
141 if (fuse_block_alloc(fc
, for_background
)) {
143 if (wait_event_killable_exclusive(fc
->blocked_waitq
,
144 !fuse_block_alloc(fc
, for_background
)))
147 /* Matches smp_wmb() in fuse_set_initialized() */
158 req
= fuse_request_alloc(npages
);
162 wake_up(&fc
->blocked_waitq
);
166 fuse_req_init_context(fc
, req
);
167 __set_bit(FR_WAITING
, &req
->flags
);
169 __set_bit(FR_BACKGROUND
, &req
->flags
);
174 atomic_dec(&fc
->num_waiting
);
178 struct fuse_req
*fuse_get_req(struct fuse_conn
*fc
, unsigned npages
)
180 return __fuse_get_req(fc
, npages
, false);
182 EXPORT_SYMBOL_GPL(fuse_get_req
);
184 struct fuse_req
*fuse_get_req_for_background(struct fuse_conn
*fc
,
187 return __fuse_get_req(fc
, npages
, true);
189 EXPORT_SYMBOL_GPL(fuse_get_req_for_background
);
192 * Return request in fuse_file->reserved_req. However that may
193 * currently be in use. If that is the case, wait for it to become
196 static struct fuse_req
*get_reserved_req(struct fuse_conn
*fc
,
199 struct fuse_req
*req
= NULL
;
200 struct fuse_file
*ff
= file
->private_data
;
203 wait_event(fc
->reserved_req_waitq
, ff
->reserved_req
);
204 spin_lock(&fc
->lock
);
205 if (ff
->reserved_req
) {
206 req
= ff
->reserved_req
;
207 ff
->reserved_req
= NULL
;
208 req
->stolen_file
= get_file(file
);
210 spin_unlock(&fc
->lock
);
217 * Put stolen request back into fuse_file->reserved_req
219 static void put_reserved_req(struct fuse_conn
*fc
, struct fuse_req
*req
)
221 struct file
*file
= req
->stolen_file
;
222 struct fuse_file
*ff
= file
->private_data
;
224 spin_lock(&fc
->lock
);
225 fuse_request_init(req
, req
->pages
, req
->page_descs
, req
->max_pages
);
226 BUG_ON(ff
->reserved_req
);
227 ff
->reserved_req
= req
;
228 wake_up_all(&fc
->reserved_req_waitq
);
229 spin_unlock(&fc
->lock
);
234 * Gets a requests for a file operation, always succeeds
236 * This is used for sending the FLUSH request, which must get to
237 * userspace, due to POSIX locks which may need to be unlocked.
239 * If allocation fails due to OOM, use the reserved request in
242 * This is very unlikely to deadlock accidentally, since the
243 * filesystem should not have it's own file open. If deadlock is
244 * intentional, it can still be broken by "aborting" the filesystem.
246 struct fuse_req
*fuse_get_req_nofail_nopages(struct fuse_conn
*fc
,
249 struct fuse_req
*req
;
251 atomic_inc(&fc
->num_waiting
);
252 wait_event(fc
->blocked_waitq
, fc
->initialized
);
253 /* Matches smp_wmb() in fuse_set_initialized() */
255 req
= fuse_request_alloc(0);
257 req
= get_reserved_req(fc
, file
);
259 fuse_req_init_context(fc
, req
);
260 __set_bit(FR_WAITING
, &req
->flags
);
261 __clear_bit(FR_BACKGROUND
, &req
->flags
);
265 void fuse_put_request(struct fuse_conn
*fc
, struct fuse_req
*req
)
267 if (refcount_dec_and_test(&req
->count
)) {
268 if (test_bit(FR_BACKGROUND
, &req
->flags
)) {
270 * We get here in the unlikely case that a background
271 * request was allocated but not sent
273 spin_lock(&fc
->lock
);
275 wake_up(&fc
->blocked_waitq
);
276 spin_unlock(&fc
->lock
);
279 if (test_bit(FR_WAITING
, &req
->flags
)) {
280 __clear_bit(FR_WAITING
, &req
->flags
);
281 atomic_dec(&fc
->num_waiting
);
284 if (req
->stolen_file
)
285 put_reserved_req(fc
, req
);
287 fuse_request_free(req
);
290 EXPORT_SYMBOL_GPL(fuse_put_request
);
292 static unsigned len_args(unsigned numargs
, struct fuse_arg
*args
)
297 for (i
= 0; i
< numargs
; i
++)
298 nbytes
+= args
[i
].size
;
303 static u64
fuse_get_unique(struct fuse_iqueue
*fiq
)
305 return ++fiq
->reqctr
;
308 static void queue_request(struct fuse_iqueue
*fiq
, struct fuse_req
*req
)
310 req
->in
.h
.len
= sizeof(struct fuse_in_header
) +
311 len_args(req
->in
.numargs
, (struct fuse_arg
*) req
->in
.args
);
312 list_add_tail(&req
->list
, &fiq
->pending
);
313 wake_up_locked(&fiq
->waitq
);
314 kill_fasync(&fiq
->fasync
, SIGIO
, POLL_IN
);
317 void fuse_queue_forget(struct fuse_conn
*fc
, struct fuse_forget_link
*forget
,
318 u64 nodeid
, u64 nlookup
)
320 struct fuse_iqueue
*fiq
= &fc
->iq
;
322 forget
->forget_one
.nodeid
= nodeid
;
323 forget
->forget_one
.nlookup
= nlookup
;
325 spin_lock(&fiq
->waitq
.lock
);
326 if (fiq
->connected
) {
327 fiq
->forget_list_tail
->next
= forget
;
328 fiq
->forget_list_tail
= forget
;
329 wake_up_locked(&fiq
->waitq
);
330 kill_fasync(&fiq
->fasync
, SIGIO
, POLL_IN
);
334 spin_unlock(&fiq
->waitq
.lock
);
337 static void flush_bg_queue(struct fuse_conn
*fc
)
339 while (fc
->active_background
< fc
->max_background
&&
340 !list_empty(&fc
->bg_queue
)) {
341 struct fuse_req
*req
;
342 struct fuse_iqueue
*fiq
= &fc
->iq
;
344 req
= list_entry(fc
->bg_queue
.next
, struct fuse_req
, list
);
345 list_del(&req
->list
);
346 fc
->active_background
++;
347 spin_lock(&fiq
->waitq
.lock
);
348 req
->in
.h
.unique
= fuse_get_unique(fiq
);
349 queue_request(fiq
, req
);
350 spin_unlock(&fiq
->waitq
.lock
);
355 * This function is called when a request is finished. Either a reply
356 * has arrived or it was aborted (and not yet sent) or some error
357 * occurred during communication with userspace, or the device file
358 * was closed. The requester thread is woken up (if still waiting),
359 * the 'end' callback is called if given, else the reference to the
360 * request is released
362 static void request_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
364 struct fuse_iqueue
*fiq
= &fc
->iq
;
366 if (test_and_set_bit(FR_FINISHED
, &req
->flags
))
369 spin_lock(&fiq
->waitq
.lock
);
370 list_del_init(&req
->intr_entry
);
371 spin_unlock(&fiq
->waitq
.lock
);
372 WARN_ON(test_bit(FR_PENDING
, &req
->flags
));
373 WARN_ON(test_bit(FR_SENT
, &req
->flags
));
374 if (test_bit(FR_BACKGROUND
, &req
->flags
)) {
375 spin_lock(&fc
->lock
);
376 clear_bit(FR_BACKGROUND
, &req
->flags
);
377 if (fc
->num_background
== fc
->max_background
)
380 /* Wake up next waiter, if any */
381 if (!fc
->blocked
&& waitqueue_active(&fc
->blocked_waitq
))
382 wake_up(&fc
->blocked_waitq
);
384 if (fc
->num_background
== fc
->congestion_threshold
&&
385 fc
->connected
&& fc
->sb
) {
386 clear_bdi_congested(fc
->sb
->s_bdi
, BLK_RW_SYNC
);
387 clear_bdi_congested(fc
->sb
->s_bdi
, BLK_RW_ASYNC
);
389 fc
->num_background
--;
390 fc
->active_background
--;
392 spin_unlock(&fc
->lock
);
394 wake_up(&req
->waitq
);
397 fuse_put_request(fc
, req
);
400 static void queue_interrupt(struct fuse_iqueue
*fiq
, struct fuse_req
*req
)
402 spin_lock(&fiq
->waitq
.lock
);
403 if (test_bit(FR_FINISHED
, &req
->flags
)) {
404 spin_unlock(&fiq
->waitq
.lock
);
407 if (list_empty(&req
->intr_entry
)) {
408 list_add_tail(&req
->intr_entry
, &fiq
->interrupts
);
409 wake_up_locked(&fiq
->waitq
);
411 spin_unlock(&fiq
->waitq
.lock
);
412 kill_fasync(&fiq
->fasync
, SIGIO
, POLL_IN
);
415 static void request_wait_answer(struct fuse_conn
*fc
, struct fuse_req
*req
)
417 struct fuse_iqueue
*fiq
= &fc
->iq
;
420 if (!fc
->no_interrupt
) {
421 /* Any signal may interrupt this */
422 err
= wait_event_interruptible(req
->waitq
,
423 test_bit(FR_FINISHED
, &req
->flags
));
427 set_bit(FR_INTERRUPTED
, &req
->flags
);
428 /* matches barrier in fuse_dev_do_read() */
429 smp_mb__after_atomic();
430 if (test_bit(FR_SENT
, &req
->flags
))
431 queue_interrupt(fiq
, req
);
434 if (!test_bit(FR_FORCE
, &req
->flags
)) {
435 /* Only fatal signals may interrupt this */
436 err
= wait_event_killable(req
->waitq
,
437 test_bit(FR_FINISHED
, &req
->flags
));
441 spin_lock(&fiq
->waitq
.lock
);
442 /* Request is not yet in userspace, bail out */
443 if (test_bit(FR_PENDING
, &req
->flags
)) {
444 list_del(&req
->list
);
445 spin_unlock(&fiq
->waitq
.lock
);
446 __fuse_put_request(req
);
447 req
->out
.h
.error
= -EINTR
;
450 spin_unlock(&fiq
->waitq
.lock
);
454 * Either request is already in userspace, or it was forced.
457 wait_event(req
->waitq
, test_bit(FR_FINISHED
, &req
->flags
));
460 static void __fuse_request_send(struct fuse_conn
*fc
, struct fuse_req
*req
)
462 struct fuse_iqueue
*fiq
= &fc
->iq
;
464 BUG_ON(test_bit(FR_BACKGROUND
, &req
->flags
));
465 spin_lock(&fiq
->waitq
.lock
);
466 if (!fiq
->connected
) {
467 spin_unlock(&fiq
->waitq
.lock
);
468 req
->out
.h
.error
= -ENOTCONN
;
470 req
->in
.h
.unique
= fuse_get_unique(fiq
);
471 queue_request(fiq
, req
);
472 /* acquire extra reference, since request is still needed
473 after request_end() */
474 __fuse_get_request(req
);
475 spin_unlock(&fiq
->waitq
.lock
);
477 request_wait_answer(fc
, req
);
478 /* Pairs with smp_wmb() in request_end() */
483 void fuse_request_send(struct fuse_conn
*fc
, struct fuse_req
*req
)
485 __set_bit(FR_ISREPLY
, &req
->flags
);
486 if (!test_bit(FR_WAITING
, &req
->flags
)) {
487 __set_bit(FR_WAITING
, &req
->flags
);
488 atomic_inc(&fc
->num_waiting
);
490 __fuse_request_send(fc
, req
);
492 EXPORT_SYMBOL_GPL(fuse_request_send
);
494 static void fuse_adjust_compat(struct fuse_conn
*fc
, struct fuse_args
*args
)
496 if (fc
->minor
< 4 && args
->in
.h
.opcode
== FUSE_STATFS
)
497 args
->out
.args
[0].size
= FUSE_COMPAT_STATFS_SIZE
;
500 switch (args
->in
.h
.opcode
) {
507 args
->out
.args
[0].size
= FUSE_COMPAT_ENTRY_OUT_SIZE
;
511 args
->out
.args
[0].size
= FUSE_COMPAT_ATTR_OUT_SIZE
;
515 if (fc
->minor
< 12) {
516 switch (args
->in
.h
.opcode
) {
518 args
->in
.args
[0].size
= sizeof(struct fuse_open_in
);
521 args
->in
.args
[0].size
= FUSE_COMPAT_MKNOD_IN_SIZE
;
527 ssize_t
fuse_simple_request(struct fuse_conn
*fc
, struct fuse_args
*args
)
529 struct fuse_req
*req
;
532 req
= fuse_get_req(fc
, 0);
536 /* Needs to be done after fuse_get_req() so that fc->minor is valid */
537 fuse_adjust_compat(fc
, args
);
539 req
->in
.h
.opcode
= args
->in
.h
.opcode
;
540 req
->in
.h
.nodeid
= args
->in
.h
.nodeid
;
541 req
->in
.numargs
= args
->in
.numargs
;
542 memcpy(req
->in
.args
, args
->in
.args
,
543 args
->in
.numargs
* sizeof(struct fuse_in_arg
));
544 req
->out
.argvar
= args
->out
.argvar
;
545 req
->out
.numargs
= args
->out
.numargs
;
546 memcpy(req
->out
.args
, args
->out
.args
,
547 args
->out
.numargs
* sizeof(struct fuse_arg
));
548 fuse_request_send(fc
, req
);
549 ret
= req
->out
.h
.error
;
550 if (!ret
&& args
->out
.argvar
) {
551 BUG_ON(args
->out
.numargs
!= 1);
552 ret
= req
->out
.args
[0].size
;
554 fuse_put_request(fc
, req
);
560 * Called under fc->lock
562 * fc->connected must have been checked previously
564 void fuse_request_send_background_locked(struct fuse_conn
*fc
,
565 struct fuse_req
*req
)
567 BUG_ON(!test_bit(FR_BACKGROUND
, &req
->flags
));
568 if (!test_bit(FR_WAITING
, &req
->flags
)) {
569 __set_bit(FR_WAITING
, &req
->flags
);
570 atomic_inc(&fc
->num_waiting
);
572 __set_bit(FR_ISREPLY
, &req
->flags
);
573 fc
->num_background
++;
574 if (fc
->num_background
== fc
->max_background
)
576 if (fc
->num_background
== fc
->congestion_threshold
&& fc
->sb
) {
577 set_bdi_congested(fc
->sb
->s_bdi
, BLK_RW_SYNC
);
578 set_bdi_congested(fc
->sb
->s_bdi
, BLK_RW_ASYNC
);
580 list_add_tail(&req
->list
, &fc
->bg_queue
);
584 void fuse_request_send_background(struct fuse_conn
*fc
, struct fuse_req
*req
)
587 spin_lock(&fc
->lock
);
589 fuse_request_send_background_locked(fc
, req
);
590 spin_unlock(&fc
->lock
);
592 spin_unlock(&fc
->lock
);
593 req
->out
.h
.error
= -ENOTCONN
;
595 fuse_put_request(fc
, req
);
598 EXPORT_SYMBOL_GPL(fuse_request_send_background
);
600 static int fuse_request_send_notify_reply(struct fuse_conn
*fc
,
601 struct fuse_req
*req
, u64 unique
)
604 struct fuse_iqueue
*fiq
= &fc
->iq
;
606 __clear_bit(FR_ISREPLY
, &req
->flags
);
607 req
->in
.h
.unique
= unique
;
608 spin_lock(&fiq
->waitq
.lock
);
609 if (fiq
->connected
) {
610 queue_request(fiq
, req
);
613 spin_unlock(&fiq
->waitq
.lock
);
618 void fuse_force_forget(struct file
*file
, u64 nodeid
)
620 struct inode
*inode
= file_inode(file
);
621 struct fuse_conn
*fc
= get_fuse_conn(inode
);
622 struct fuse_req
*req
;
623 struct fuse_forget_in inarg
;
625 memset(&inarg
, 0, sizeof(inarg
));
627 req
= fuse_get_req_nofail_nopages(fc
, file
);
628 req
->in
.h
.opcode
= FUSE_FORGET
;
629 req
->in
.h
.nodeid
= nodeid
;
631 req
->in
.args
[0].size
= sizeof(inarg
);
632 req
->in
.args
[0].value
= &inarg
;
633 __clear_bit(FR_ISREPLY
, &req
->flags
);
634 __fuse_request_send(fc
, req
);
636 fuse_put_request(fc
, req
);
640 * Lock the request. Up to the next unlock_request() there mustn't be
641 * anything that could cause a page-fault. If the request was already
644 static int lock_request(struct fuse_req
*req
)
648 spin_lock(&req
->waitq
.lock
);
649 if (test_bit(FR_ABORTED
, &req
->flags
))
652 set_bit(FR_LOCKED
, &req
->flags
);
653 spin_unlock(&req
->waitq
.lock
);
659 * Unlock request. If it was aborted while locked, caller is responsible
660 * for unlocking and ending the request.
662 static int unlock_request(struct fuse_req
*req
)
666 spin_lock(&req
->waitq
.lock
);
667 if (test_bit(FR_ABORTED
, &req
->flags
))
670 clear_bit(FR_LOCKED
, &req
->flags
);
671 spin_unlock(&req
->waitq
.lock
);
676 struct fuse_copy_state
{
678 struct fuse_req
*req
;
679 struct iov_iter
*iter
;
680 struct pipe_buffer
*pipebufs
;
681 struct pipe_buffer
*currbuf
;
682 struct pipe_inode_info
*pipe
;
683 unsigned long nr_segs
;
687 unsigned move_pages
:1;
690 static void fuse_copy_init(struct fuse_copy_state
*cs
, int write
,
691 struct iov_iter
*iter
)
693 memset(cs
, 0, sizeof(*cs
));
698 /* Unmap and put previous page of userspace buffer */
699 static void fuse_copy_finish(struct fuse_copy_state
*cs
)
702 struct pipe_buffer
*buf
= cs
->currbuf
;
705 buf
->len
= PAGE_SIZE
- cs
->len
;
709 flush_dcache_page(cs
->pg
);
710 set_page_dirty_lock(cs
->pg
);
718 * Get another pagefull of userspace buffer, and map it to kernel
719 * address space, and lock request
721 static int fuse_copy_fill(struct fuse_copy_state
*cs
)
726 err
= unlock_request(cs
->req
);
730 fuse_copy_finish(cs
);
732 struct pipe_buffer
*buf
= cs
->pipebufs
;
735 err
= pipe_buf_confirm(cs
->pipe
, buf
);
739 BUG_ON(!cs
->nr_segs
);
742 cs
->offset
= buf
->offset
;
747 if (cs
->nr_segs
== cs
->pipe
->buffers
)
750 page
= alloc_page(GFP_HIGHUSER
);
767 err
= iov_iter_get_pages(cs
->iter
, &page
, PAGE_SIZE
, 1, &off
);
774 iov_iter_advance(cs
->iter
, err
);
777 return lock_request(cs
->req
);
780 /* Do as much copy to/from userspace buffer as we can */
781 static int fuse_copy_do(struct fuse_copy_state
*cs
, void **val
, unsigned *size
)
783 unsigned ncpy
= min(*size
, cs
->len
);
785 void *pgaddr
= kmap_atomic(cs
->pg
);
786 void *buf
= pgaddr
+ cs
->offset
;
789 memcpy(buf
, *val
, ncpy
);
791 memcpy(*val
, buf
, ncpy
);
793 kunmap_atomic(pgaddr
);
802 static int fuse_check_page(struct page
*page
)
804 if (page_mapcount(page
) ||
805 page
->mapping
!= NULL
||
806 page_count(page
) != 1 ||
807 (page
->flags
& PAGE_FLAGS_CHECK_AT_PREP
&
814 printk(KERN_WARNING
"fuse: trying to steal weird page\n");
815 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
);
821 static int fuse_try_move_page(struct fuse_copy_state
*cs
, struct page
**pagep
)
824 struct page
*oldpage
= *pagep
;
825 struct page
*newpage
;
826 struct pipe_buffer
*buf
= cs
->pipebufs
;
828 err
= unlock_request(cs
->req
);
832 fuse_copy_finish(cs
);
834 err
= pipe_buf_confirm(cs
->pipe
, buf
);
838 BUG_ON(!cs
->nr_segs
);
844 if (cs
->len
!= PAGE_SIZE
)
847 if (pipe_buf_steal(cs
->pipe
, buf
) != 0)
852 if (!PageUptodate(newpage
))
853 SetPageUptodate(newpage
);
855 ClearPageMappedToDisk(newpage
);
857 if (fuse_check_page(newpage
) != 0)
858 goto out_fallback_unlock
;
861 * This is a new and locked page, it shouldn't be mapped or
862 * have any special flags on it
864 if (WARN_ON(page_mapped(oldpage
)))
865 goto out_fallback_unlock
;
866 if (WARN_ON(page_has_private(oldpage
)))
867 goto out_fallback_unlock
;
868 if (WARN_ON(PageDirty(oldpage
) || PageWriteback(oldpage
)))
869 goto out_fallback_unlock
;
870 if (WARN_ON(PageMlocked(oldpage
)))
871 goto out_fallback_unlock
;
873 err
= replace_page_cache_page(oldpage
, newpage
, GFP_KERNEL
);
875 unlock_page(newpage
);
881 if (!(buf
->flags
& PIPE_BUF_FLAG_LRU
))
882 lru_cache_add_file(newpage
);
885 spin_lock(&cs
->req
->waitq
.lock
);
886 if (test_bit(FR_ABORTED
, &cs
->req
->flags
))
890 spin_unlock(&cs
->req
->waitq
.lock
);
893 unlock_page(newpage
);
898 unlock_page(oldpage
);
905 unlock_page(newpage
);
908 cs
->offset
= buf
->offset
;
910 err
= lock_request(cs
->req
);
917 static int fuse_ref_page(struct fuse_copy_state
*cs
, struct page
*page
,
918 unsigned offset
, unsigned count
)
920 struct pipe_buffer
*buf
;
923 if (cs
->nr_segs
== cs
->pipe
->buffers
)
926 err
= unlock_request(cs
->req
);
930 fuse_copy_finish(cs
);
935 buf
->offset
= offset
;
946 * Copy a page in the request to/from the userspace buffer. Must be
949 static int fuse_copy_page(struct fuse_copy_state
*cs
, struct page
**pagep
,
950 unsigned offset
, unsigned count
, int zeroing
)
953 struct page
*page
= *pagep
;
955 if (page
&& zeroing
&& count
< PAGE_SIZE
)
956 clear_highpage(page
);
959 if (cs
->write
&& cs
->pipebufs
&& page
) {
960 return fuse_ref_page(cs
, page
, offset
, count
);
961 } else if (!cs
->len
) {
962 if (cs
->move_pages
&& page
&&
963 offset
== 0 && count
== PAGE_SIZE
) {
964 err
= fuse_try_move_page(cs
, pagep
);
968 err
= fuse_copy_fill(cs
);
974 void *mapaddr
= kmap_atomic(page
);
975 void *buf
= mapaddr
+ offset
;
976 offset
+= fuse_copy_do(cs
, &buf
, &count
);
977 kunmap_atomic(mapaddr
);
979 offset
+= fuse_copy_do(cs
, NULL
, &count
);
981 if (page
&& !cs
->write
)
982 flush_dcache_page(page
);
986 /* Copy pages in the request to/from userspace buffer */
987 static int fuse_copy_pages(struct fuse_copy_state
*cs
, unsigned nbytes
,
991 struct fuse_req
*req
= cs
->req
;
993 for (i
= 0; i
< req
->num_pages
&& (nbytes
|| zeroing
); i
++) {
995 unsigned offset
= req
->page_descs
[i
].offset
;
996 unsigned count
= min(nbytes
, req
->page_descs
[i
].length
);
998 err
= fuse_copy_page(cs
, &req
->pages
[i
], offset
, count
,
1008 /* Copy a single argument in the request to/from userspace buffer */
1009 static int fuse_copy_one(struct fuse_copy_state
*cs
, void *val
, unsigned size
)
1013 int err
= fuse_copy_fill(cs
);
1017 fuse_copy_do(cs
, &val
, &size
);
1022 /* Copy request arguments to/from userspace buffer */
1023 static int fuse_copy_args(struct fuse_copy_state
*cs
, unsigned numargs
,
1024 unsigned argpages
, struct fuse_arg
*args
,
1030 for (i
= 0; !err
&& i
< numargs
; i
++) {
1031 struct fuse_arg
*arg
= &args
[i
];
1032 if (i
== numargs
- 1 && argpages
)
1033 err
= fuse_copy_pages(cs
, arg
->size
, zeroing
);
1035 err
= fuse_copy_one(cs
, arg
->value
, arg
->size
);
1040 static int forget_pending(struct fuse_iqueue
*fiq
)
1042 return fiq
->forget_list_head
.next
!= NULL
;
1045 static int request_pending(struct fuse_iqueue
*fiq
)
1047 return !list_empty(&fiq
->pending
) || !list_empty(&fiq
->interrupts
) ||
1048 forget_pending(fiq
);
1052 * Transfer an interrupt request to userspace
1054 * Unlike other requests this is assembled on demand, without a need
1055 * to allocate a separate fuse_req structure.
1057 * Called with fiq->waitq.lock held, releases it
1059 static int fuse_read_interrupt(struct fuse_iqueue
*fiq
,
1060 struct fuse_copy_state
*cs
,
1061 size_t nbytes
, struct fuse_req
*req
)
1062 __releases(fiq
->waitq
.lock
)
1064 struct fuse_in_header ih
;
1065 struct fuse_interrupt_in arg
;
1066 unsigned reqsize
= sizeof(ih
) + sizeof(arg
);
1069 list_del_init(&req
->intr_entry
);
1070 req
->intr_unique
= fuse_get_unique(fiq
);
1071 memset(&ih
, 0, sizeof(ih
));
1072 memset(&arg
, 0, sizeof(arg
));
1074 ih
.opcode
= FUSE_INTERRUPT
;
1075 ih
.unique
= req
->intr_unique
;
1076 arg
.unique
= req
->in
.h
.unique
;
1078 spin_unlock(&fiq
->waitq
.lock
);
1079 if (nbytes
< reqsize
)
1082 err
= fuse_copy_one(cs
, &ih
, sizeof(ih
));
1084 err
= fuse_copy_one(cs
, &arg
, sizeof(arg
));
1085 fuse_copy_finish(cs
);
1087 return err
? err
: reqsize
;
1090 static struct fuse_forget_link
*dequeue_forget(struct fuse_iqueue
*fiq
,
1094 struct fuse_forget_link
*head
= fiq
->forget_list_head
.next
;
1095 struct fuse_forget_link
**newhead
= &head
;
1098 for (count
= 0; *newhead
!= NULL
&& count
< max
; count
++)
1099 newhead
= &(*newhead
)->next
;
1101 fiq
->forget_list_head
.next
= *newhead
;
1103 if (fiq
->forget_list_head
.next
== NULL
)
1104 fiq
->forget_list_tail
= &fiq
->forget_list_head
;
1112 static int fuse_read_single_forget(struct fuse_iqueue
*fiq
,
1113 struct fuse_copy_state
*cs
,
1115 __releases(fiq
->waitq
.lock
)
1118 struct fuse_forget_link
*forget
= dequeue_forget(fiq
, 1, NULL
);
1119 struct fuse_forget_in arg
= {
1120 .nlookup
= forget
->forget_one
.nlookup
,
1122 struct fuse_in_header ih
= {
1123 .opcode
= FUSE_FORGET
,
1124 .nodeid
= forget
->forget_one
.nodeid
,
1125 .unique
= fuse_get_unique(fiq
),
1126 .len
= sizeof(ih
) + sizeof(arg
),
1129 spin_unlock(&fiq
->waitq
.lock
);
1131 if (nbytes
< ih
.len
)
1134 err
= fuse_copy_one(cs
, &ih
, sizeof(ih
));
1136 err
= fuse_copy_one(cs
, &arg
, sizeof(arg
));
1137 fuse_copy_finish(cs
);
1145 static int fuse_read_batch_forget(struct fuse_iqueue
*fiq
,
1146 struct fuse_copy_state
*cs
, size_t nbytes
)
1147 __releases(fiq
->waitq
.lock
)
1150 unsigned max_forgets
;
1152 struct fuse_forget_link
*head
;
1153 struct fuse_batch_forget_in arg
= { .count
= 0 };
1154 struct fuse_in_header ih
= {
1155 .opcode
= FUSE_BATCH_FORGET
,
1156 .unique
= fuse_get_unique(fiq
),
1157 .len
= sizeof(ih
) + sizeof(arg
),
1160 if (nbytes
< ih
.len
) {
1161 spin_unlock(&fiq
->waitq
.lock
);
1165 max_forgets
= (nbytes
- ih
.len
) / sizeof(struct fuse_forget_one
);
1166 head
= dequeue_forget(fiq
, max_forgets
, &count
);
1167 spin_unlock(&fiq
->waitq
.lock
);
1170 ih
.len
+= count
* sizeof(struct fuse_forget_one
);
1171 err
= fuse_copy_one(cs
, &ih
, sizeof(ih
));
1173 err
= fuse_copy_one(cs
, &arg
, sizeof(arg
));
1176 struct fuse_forget_link
*forget
= head
;
1179 err
= fuse_copy_one(cs
, &forget
->forget_one
,
1180 sizeof(forget
->forget_one
));
1182 head
= forget
->next
;
1186 fuse_copy_finish(cs
);
1194 static int fuse_read_forget(struct fuse_conn
*fc
, struct fuse_iqueue
*fiq
,
1195 struct fuse_copy_state
*cs
,
1197 __releases(fiq
->waitq
.lock
)
1199 if (fc
->minor
< 16 || fiq
->forget_list_head
.next
->next
== NULL
)
1200 return fuse_read_single_forget(fiq
, cs
, nbytes
);
1202 return fuse_read_batch_forget(fiq
, cs
, nbytes
);
1206 * Read a single request into the userspace filesystem's buffer. This
1207 * function waits until a request is available, then removes it from
1208 * the pending list and copies request data to userspace buffer. If
1209 * no reply is needed (FORGET) or request has been aborted or there
1210 * was an error during the copying then it's finished by calling
1211 * request_end(). Otherwise add it to the processing list, and set
1214 static ssize_t
fuse_dev_do_read(struct fuse_dev
*fud
, struct file
*file
,
1215 struct fuse_copy_state
*cs
, size_t nbytes
)
1218 struct fuse_conn
*fc
= fud
->fc
;
1219 struct fuse_iqueue
*fiq
= &fc
->iq
;
1220 struct fuse_pqueue
*fpq
= &fud
->pq
;
1221 struct fuse_req
*req
;
1225 if (task_active_pid_ns(current
) != fc
->pid_ns
)
1229 spin_lock(&fiq
->waitq
.lock
);
1231 if ((file
->f_flags
& O_NONBLOCK
) && fiq
->connected
&&
1232 !request_pending(fiq
))
1235 err
= wait_event_interruptible_exclusive_locked(fiq
->waitq
,
1236 !fiq
->connected
|| request_pending(fiq
));
1241 if (!fiq
->connected
)
1244 if (!list_empty(&fiq
->interrupts
)) {
1245 req
= list_entry(fiq
->interrupts
.next
, struct fuse_req
,
1247 return fuse_read_interrupt(fiq
, cs
, nbytes
, req
);
1250 if (forget_pending(fiq
)) {
1251 if (list_empty(&fiq
->pending
) || fiq
->forget_batch
-- > 0)
1252 return fuse_read_forget(fc
, fiq
, cs
, nbytes
);
1254 if (fiq
->forget_batch
<= -8)
1255 fiq
->forget_batch
= 16;
1258 req
= list_entry(fiq
->pending
.next
, struct fuse_req
, list
);
1259 clear_bit(FR_PENDING
, &req
->flags
);
1260 list_del_init(&req
->list
);
1261 spin_unlock(&fiq
->waitq
.lock
);
1264 reqsize
= in
->h
.len
;
1265 /* If request is too large, reply with an error and restart the read */
1266 if (nbytes
< reqsize
) {
1267 req
->out
.h
.error
= -EIO
;
1268 /* SETXATTR is special, since it may contain too large data */
1269 if (in
->h
.opcode
== FUSE_SETXATTR
)
1270 req
->out
.h
.error
= -E2BIG
;
1271 request_end(fc
, req
);
1274 spin_lock(&fpq
->lock
);
1275 list_add(&req
->list
, &fpq
->io
);
1276 spin_unlock(&fpq
->lock
);
1278 err
= fuse_copy_one(cs
, &in
->h
, sizeof(in
->h
));
1280 err
= fuse_copy_args(cs
, in
->numargs
, in
->argpages
,
1281 (struct fuse_arg
*) in
->args
, 0);
1282 fuse_copy_finish(cs
);
1283 spin_lock(&fpq
->lock
);
1284 clear_bit(FR_LOCKED
, &req
->flags
);
1285 if (!fpq
->connected
) {
1290 req
->out
.h
.error
= -EIO
;
1293 if (!test_bit(FR_ISREPLY
, &req
->flags
)) {
1297 list_move_tail(&req
->list
, &fpq
->processing
);
1298 spin_unlock(&fpq
->lock
);
1299 set_bit(FR_SENT
, &req
->flags
);
1300 /* matches barrier in request_wait_answer() */
1301 smp_mb__after_atomic();
1302 if (test_bit(FR_INTERRUPTED
, &req
->flags
))
1303 queue_interrupt(fiq
, req
);
1308 if (!test_bit(FR_PRIVATE
, &req
->flags
))
1309 list_del_init(&req
->list
);
1310 spin_unlock(&fpq
->lock
);
1311 request_end(fc
, req
);
1315 spin_unlock(&fiq
->waitq
.lock
);
1319 static int fuse_dev_open(struct inode
*inode
, struct file
*file
)
1322 * The fuse device's file's private_data is used to hold
1323 * the fuse_conn(ection) when it is mounted, and is used to
1324 * keep track of whether the file has been mounted already.
1326 file
->private_data
= NULL
;
1330 static ssize_t
fuse_dev_read(struct kiocb
*iocb
, struct iov_iter
*to
)
1332 struct fuse_copy_state cs
;
1333 struct file
*file
= iocb
->ki_filp
;
1334 struct fuse_dev
*fud
= fuse_get_dev(file
);
1339 if (!iter_is_iovec(to
))
1342 fuse_copy_init(&cs
, 1, to
);
1344 return fuse_dev_do_read(fud
, file
, &cs
, iov_iter_count(to
));
1347 static ssize_t
fuse_dev_splice_read(struct file
*in
, loff_t
*ppos
,
1348 struct pipe_inode_info
*pipe
,
1349 size_t len
, unsigned int flags
)
1353 struct pipe_buffer
*bufs
;
1354 struct fuse_copy_state cs
;
1355 struct fuse_dev
*fud
= fuse_get_dev(in
);
1360 bufs
= kmalloc(pipe
->buffers
* sizeof(struct pipe_buffer
), GFP_KERNEL
);
1364 fuse_copy_init(&cs
, 1, NULL
);
1367 ret
= fuse_dev_do_read(fud
, in
, &cs
, len
);
1371 if (pipe
->nrbufs
+ cs
.nr_segs
> pipe
->buffers
) {
1376 for (ret
= total
= 0; page_nr
< cs
.nr_segs
; total
+= ret
) {
1378 * Need to be careful about this. Having buf->ops in module
1379 * code can Oops if the buffer persists after module unload.
1381 bufs
[page_nr
].ops
= &nosteal_pipe_buf_ops
;
1382 bufs
[page_nr
].flags
= 0;
1383 ret
= add_to_pipe(pipe
, &bufs
[page_nr
++]);
1384 if (unlikely(ret
< 0))
1390 for (; page_nr
< cs
.nr_segs
; page_nr
++)
1391 put_page(bufs
[page_nr
].page
);
1397 static int fuse_notify_poll(struct fuse_conn
*fc
, unsigned int size
,
1398 struct fuse_copy_state
*cs
)
1400 struct fuse_notify_poll_wakeup_out outarg
;
1403 if (size
!= sizeof(outarg
))
1406 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1410 fuse_copy_finish(cs
);
1411 return fuse_notify_poll_wakeup(fc
, &outarg
);
1414 fuse_copy_finish(cs
);
1418 static int fuse_notify_inval_inode(struct fuse_conn
*fc
, unsigned int size
,
1419 struct fuse_copy_state
*cs
)
1421 struct fuse_notify_inval_inode_out outarg
;
1424 if (size
!= sizeof(outarg
))
1427 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1430 fuse_copy_finish(cs
);
1432 down_read(&fc
->killsb
);
1435 err
= fuse_reverse_inval_inode(fc
->sb
, outarg
.ino
,
1436 outarg
.off
, outarg
.len
);
1438 up_read(&fc
->killsb
);
1442 fuse_copy_finish(cs
);
1446 static int fuse_notify_inval_entry(struct fuse_conn
*fc
, unsigned int size
,
1447 struct fuse_copy_state
*cs
)
1449 struct fuse_notify_inval_entry_out outarg
;
1454 buf
= kzalloc(FUSE_NAME_MAX
+ 1, GFP_KERNEL
);
1459 if (size
< sizeof(outarg
))
1462 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1466 err
= -ENAMETOOLONG
;
1467 if (outarg
.namelen
> FUSE_NAME_MAX
)
1471 if (size
!= sizeof(outarg
) + outarg
.namelen
+ 1)
1475 name
.len
= outarg
.namelen
;
1476 err
= fuse_copy_one(cs
, buf
, outarg
.namelen
+ 1);
1479 fuse_copy_finish(cs
);
1480 buf
[outarg
.namelen
] = 0;
1482 down_read(&fc
->killsb
);
1485 err
= fuse_reverse_inval_entry(fc
->sb
, outarg
.parent
, 0, &name
);
1486 up_read(&fc
->killsb
);
1492 fuse_copy_finish(cs
);
1496 static int fuse_notify_delete(struct fuse_conn
*fc
, unsigned int size
,
1497 struct fuse_copy_state
*cs
)
1499 struct fuse_notify_delete_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;
1532 down_read(&fc
->killsb
);
1535 err
= fuse_reverse_inval_entry(fc
->sb
, outarg
.parent
,
1536 outarg
.child
, &name
);
1537 up_read(&fc
->killsb
);
1543 fuse_copy_finish(cs
);
1547 static int fuse_notify_store(struct fuse_conn
*fc
, unsigned int size
,
1548 struct fuse_copy_state
*cs
)
1550 struct fuse_notify_store_out outarg
;
1551 struct inode
*inode
;
1552 struct address_space
*mapping
;
1556 unsigned int offset
;
1562 if (size
< sizeof(outarg
))
1565 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1570 if (size
- sizeof(outarg
) != outarg
.size
)
1573 nodeid
= outarg
.nodeid
;
1575 down_read(&fc
->killsb
);
1581 inode
= ilookup5(fc
->sb
, nodeid
, fuse_inode_eq
, &nodeid
);
1585 mapping
= inode
->i_mapping
;
1586 index
= outarg
.offset
>> PAGE_SHIFT
;
1587 offset
= outarg
.offset
& ~PAGE_MASK
;
1588 file_size
= i_size_read(inode
);
1589 end
= outarg
.offset
+ outarg
.size
;
1590 if (end
> file_size
) {
1592 fuse_write_update_size(inode
, file_size
);
1598 unsigned int this_num
;
1601 page
= find_or_create_page(mapping
, index
,
1602 mapping_gfp_mask(mapping
));
1606 this_num
= min_t(unsigned, num
, PAGE_SIZE
- offset
);
1607 err
= fuse_copy_page(cs
, &page
, offset
, this_num
, 0);
1608 if (!err
&& offset
== 0 &&
1609 (this_num
== PAGE_SIZE
|| file_size
== end
))
1610 SetPageUptodate(page
);
1627 up_read(&fc
->killsb
);
1629 fuse_copy_finish(cs
);
1633 static void fuse_retrieve_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
1635 release_pages(req
->pages
, req
->num_pages
, false);
1638 static int fuse_retrieve(struct fuse_conn
*fc
, struct inode
*inode
,
1639 struct fuse_notify_retrieve_out
*outarg
)
1642 struct address_space
*mapping
= inode
->i_mapping
;
1643 struct fuse_req
*req
;
1647 unsigned int offset
;
1648 size_t total_len
= 0;
1651 offset
= outarg
->offset
& ~PAGE_MASK
;
1652 file_size
= i_size_read(inode
);
1655 if (outarg
->offset
> file_size
)
1657 else if (outarg
->offset
+ num
> file_size
)
1658 num
= file_size
- outarg
->offset
;
1660 num_pages
= (num
+ offset
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1661 num_pages
= min(num_pages
, FUSE_MAX_PAGES_PER_REQ
);
1663 req
= fuse_get_req(fc
, num_pages
);
1665 return PTR_ERR(req
);
1667 req
->in
.h
.opcode
= FUSE_NOTIFY_REPLY
;
1668 req
->in
.h
.nodeid
= outarg
->nodeid
;
1669 req
->in
.numargs
= 2;
1670 req
->in
.argpages
= 1;
1671 req
->page_descs
[0].offset
= offset
;
1672 req
->end
= fuse_retrieve_end
;
1674 index
= outarg
->offset
>> PAGE_SHIFT
;
1676 while (num
&& req
->num_pages
< num_pages
) {
1678 unsigned int this_num
;
1680 page
= find_get_page(mapping
, index
);
1684 this_num
= min_t(unsigned, num
, PAGE_SIZE
- offset
);
1685 req
->pages
[req
->num_pages
] = page
;
1686 req
->page_descs
[req
->num_pages
].length
= this_num
;
1691 total_len
+= this_num
;
1694 req
->misc
.retrieve_in
.offset
= outarg
->offset
;
1695 req
->misc
.retrieve_in
.size
= total_len
;
1696 req
->in
.args
[0].size
= sizeof(req
->misc
.retrieve_in
);
1697 req
->in
.args
[0].value
= &req
->misc
.retrieve_in
;
1698 req
->in
.args
[1].size
= total_len
;
1700 err
= fuse_request_send_notify_reply(fc
, req
, outarg
->notify_unique
);
1702 fuse_retrieve_end(fc
, req
);
1707 static int fuse_notify_retrieve(struct fuse_conn
*fc
, unsigned int size
,
1708 struct fuse_copy_state
*cs
)
1710 struct fuse_notify_retrieve_out outarg
;
1711 struct inode
*inode
;
1715 if (size
!= sizeof(outarg
))
1718 err
= fuse_copy_one(cs
, &outarg
, sizeof(outarg
));
1722 fuse_copy_finish(cs
);
1724 down_read(&fc
->killsb
);
1727 u64 nodeid
= outarg
.nodeid
;
1729 inode
= ilookup5(fc
->sb
, nodeid
, fuse_inode_eq
, &nodeid
);
1731 err
= fuse_retrieve(fc
, inode
, &outarg
);
1735 up_read(&fc
->killsb
);
1740 fuse_copy_finish(cs
);
1744 static int fuse_notify(struct fuse_conn
*fc
, enum fuse_notify_code code
,
1745 unsigned int size
, struct fuse_copy_state
*cs
)
1747 /* Don't try to move pages (yet) */
1751 case FUSE_NOTIFY_POLL
:
1752 return fuse_notify_poll(fc
, size
, cs
);
1754 case FUSE_NOTIFY_INVAL_INODE
:
1755 return fuse_notify_inval_inode(fc
, size
, cs
);
1757 case FUSE_NOTIFY_INVAL_ENTRY
:
1758 return fuse_notify_inval_entry(fc
, size
, cs
);
1760 case FUSE_NOTIFY_STORE
:
1761 return fuse_notify_store(fc
, size
, cs
);
1763 case FUSE_NOTIFY_RETRIEVE
:
1764 return fuse_notify_retrieve(fc
, size
, cs
);
1766 case FUSE_NOTIFY_DELETE
:
1767 return fuse_notify_delete(fc
, size
, cs
);
1770 fuse_copy_finish(cs
);
1775 /* Look up request on processing list by unique ID */
1776 static struct fuse_req
*request_find(struct fuse_pqueue
*fpq
, u64 unique
)
1778 struct fuse_req
*req
;
1780 list_for_each_entry(req
, &fpq
->processing
, list
) {
1781 if (req
->in
.h
.unique
== unique
|| req
->intr_unique
== unique
)
1787 static int copy_out_args(struct fuse_copy_state
*cs
, struct fuse_out
*out
,
1790 unsigned reqsize
= sizeof(struct fuse_out_header
);
1793 return nbytes
!= reqsize
? -EINVAL
: 0;
1795 reqsize
+= len_args(out
->numargs
, out
->args
);
1797 if (reqsize
< nbytes
|| (reqsize
> nbytes
&& !out
->argvar
))
1799 else if (reqsize
> nbytes
) {
1800 struct fuse_arg
*lastarg
= &out
->args
[out
->numargs
-1];
1801 unsigned diffsize
= reqsize
- nbytes
;
1802 if (diffsize
> lastarg
->size
)
1804 lastarg
->size
-= diffsize
;
1806 return fuse_copy_args(cs
, out
->numargs
, out
->argpages
, out
->args
,
1811 * Write a single reply to a request. First the header is copied from
1812 * the write buffer. The request is then searched on the processing
1813 * list by the unique ID found in the header. If found, then remove
1814 * it from the list and copy the rest of the buffer to the request.
1815 * The request is finished by calling request_end()
1817 static ssize_t
fuse_dev_do_write(struct fuse_dev
*fud
,
1818 struct fuse_copy_state
*cs
, size_t nbytes
)
1821 struct fuse_conn
*fc
= fud
->fc
;
1822 struct fuse_pqueue
*fpq
= &fud
->pq
;
1823 struct fuse_req
*req
;
1824 struct fuse_out_header oh
;
1826 if (task_active_pid_ns(current
) != fc
->pid_ns
)
1829 if (nbytes
< sizeof(struct fuse_out_header
))
1832 err
= fuse_copy_one(cs
, &oh
, sizeof(oh
));
1837 if (oh
.len
!= nbytes
)
1841 * Zero oh.unique indicates unsolicited notification message
1842 * and error contains notification code.
1845 err
= fuse_notify(fc
, oh
.error
, nbytes
- sizeof(oh
), cs
);
1846 return err
? err
: nbytes
;
1850 if (oh
.error
<= -1000 || oh
.error
> 0)
1853 spin_lock(&fpq
->lock
);
1855 if (!fpq
->connected
)
1858 req
= request_find(fpq
, oh
.unique
);
1862 /* Is it an interrupt reply? */
1863 if (req
->intr_unique
== oh
.unique
) {
1864 spin_unlock(&fpq
->lock
);
1867 if (nbytes
!= sizeof(struct fuse_out_header
))
1870 if (oh
.error
== -ENOSYS
)
1871 fc
->no_interrupt
= 1;
1872 else if (oh
.error
== -EAGAIN
)
1873 queue_interrupt(&fc
->iq
, req
);
1875 fuse_copy_finish(cs
);
1879 clear_bit(FR_SENT
, &req
->flags
);
1880 list_move(&req
->list
, &fpq
->io
);
1882 set_bit(FR_LOCKED
, &req
->flags
);
1883 spin_unlock(&fpq
->lock
);
1885 if (!req
->out
.page_replace
)
1888 err
= copy_out_args(cs
, &req
->out
, nbytes
);
1889 fuse_copy_finish(cs
);
1891 spin_lock(&fpq
->lock
);
1892 clear_bit(FR_LOCKED
, &req
->flags
);
1893 if (!fpq
->connected
)
1896 req
->out
.h
.error
= -EIO
;
1897 if (!test_bit(FR_PRIVATE
, &req
->flags
))
1898 list_del_init(&req
->list
);
1899 spin_unlock(&fpq
->lock
);
1901 request_end(fc
, req
);
1903 return err
? err
: nbytes
;
1906 spin_unlock(&fpq
->lock
);
1908 fuse_copy_finish(cs
);
1912 static ssize_t
fuse_dev_write(struct kiocb
*iocb
, struct iov_iter
*from
)
1914 struct fuse_copy_state cs
;
1915 struct fuse_dev
*fud
= fuse_get_dev(iocb
->ki_filp
);
1920 if (!iter_is_iovec(from
))
1923 fuse_copy_init(&cs
, 0, from
);
1925 return fuse_dev_do_write(fud
, &cs
, iov_iter_count(from
));
1928 static ssize_t
fuse_dev_splice_write(struct pipe_inode_info
*pipe
,
1929 struct file
*out
, loff_t
*ppos
,
1930 size_t len
, unsigned int flags
)
1934 struct pipe_buffer
*bufs
;
1935 struct fuse_copy_state cs
;
1936 struct fuse_dev
*fud
;
1940 fud
= fuse_get_dev(out
);
1944 bufs
= kmalloc(pipe
->buffers
* sizeof(struct pipe_buffer
), GFP_KERNEL
);
1951 for (idx
= 0; idx
< pipe
->nrbufs
&& rem
< len
; idx
++)
1952 rem
+= pipe
->bufs
[(pipe
->curbuf
+ idx
) & (pipe
->buffers
- 1)].len
;
1962 struct pipe_buffer
*ibuf
;
1963 struct pipe_buffer
*obuf
;
1965 BUG_ON(nbuf
>= pipe
->buffers
);
1966 BUG_ON(!pipe
->nrbufs
);
1967 ibuf
= &pipe
->bufs
[pipe
->curbuf
];
1970 if (rem
>= ibuf
->len
) {
1973 pipe
->curbuf
= (pipe
->curbuf
+ 1) & (pipe
->buffers
- 1);
1976 pipe_buf_get(pipe
, ibuf
);
1978 obuf
->flags
&= ~PIPE_BUF_FLAG_GIFT
;
1980 ibuf
->offset
+= obuf
->len
;
1981 ibuf
->len
-= obuf
->len
;
1988 fuse_copy_init(&cs
, 0, NULL
);
1993 if (flags
& SPLICE_F_MOVE
)
1996 ret
= fuse_dev_do_write(fud
, &cs
, len
);
1998 for (idx
= 0; idx
< nbuf
; idx
++)
1999 pipe_buf_release(pipe
, &bufs
[idx
]);
2006 static unsigned fuse_dev_poll(struct file
*file
, poll_table
*wait
)
2008 unsigned mask
= POLLOUT
| POLLWRNORM
;
2009 struct fuse_iqueue
*fiq
;
2010 struct fuse_dev
*fud
= fuse_get_dev(file
);
2016 poll_wait(file
, &fiq
->waitq
, wait
);
2018 spin_lock(&fiq
->waitq
.lock
);
2019 if (!fiq
->connected
)
2021 else if (request_pending(fiq
))
2022 mask
|= POLLIN
| POLLRDNORM
;
2023 spin_unlock(&fiq
->waitq
.lock
);
2029 * Abort all requests on the given list (pending or processing)
2031 * This function releases and reacquires fc->lock
2033 static void end_requests(struct fuse_conn
*fc
, struct list_head
*head
)
2035 while (!list_empty(head
)) {
2036 struct fuse_req
*req
;
2037 req
= list_entry(head
->next
, struct fuse_req
, list
);
2038 req
->out
.h
.error
= -ECONNABORTED
;
2039 clear_bit(FR_SENT
, &req
->flags
);
2040 list_del_init(&req
->list
);
2041 request_end(fc
, req
);
2045 static void end_polls(struct fuse_conn
*fc
)
2049 p
= rb_first(&fc
->polled_files
);
2052 struct fuse_file
*ff
;
2053 ff
= rb_entry(p
, struct fuse_file
, polled_node
);
2054 wake_up_interruptible_all(&ff
->poll_wait
);
2061 * Abort all requests.
2063 * Emergency exit in case of a malicious or accidental deadlock, or just a hung
2066 * The same effect is usually achievable through killing the filesystem daemon
2067 * and all users of the filesystem. The exception is the combination of an
2068 * asynchronous request and the tricky deadlock (see
2069 * Documentation/filesystems/fuse.txt).
2071 * Aborting requests under I/O goes as follows: 1: Separate out unlocked
2072 * requests, they should be finished off immediately. Locked requests will be
2073 * finished after unlock; see unlock_request(). 2: Finish off the unlocked
2074 * requests. It is possible that some request will finish before we can. This
2075 * is OK, the request will in that case be removed from the list before we touch
2078 void fuse_abort_conn(struct fuse_conn
*fc
)
2080 struct fuse_iqueue
*fiq
= &fc
->iq
;
2082 spin_lock(&fc
->lock
);
2083 if (fc
->connected
) {
2084 struct fuse_dev
*fud
;
2085 struct fuse_req
*req
, *next
;
2091 fuse_set_initialized(fc
);
2092 list_for_each_entry(fud
, &fc
->devices
, entry
) {
2093 struct fuse_pqueue
*fpq
= &fud
->pq
;
2095 spin_lock(&fpq
->lock
);
2097 list_for_each_entry_safe(req
, next
, &fpq
->io
, list
) {
2098 req
->out
.h
.error
= -ECONNABORTED
;
2099 spin_lock(&req
->waitq
.lock
);
2100 set_bit(FR_ABORTED
, &req
->flags
);
2101 if (!test_bit(FR_LOCKED
, &req
->flags
)) {
2102 set_bit(FR_PRIVATE
, &req
->flags
);
2103 list_move(&req
->list
, &to_end1
);
2105 spin_unlock(&req
->waitq
.lock
);
2107 list_splice_init(&fpq
->processing
, &to_end2
);
2108 spin_unlock(&fpq
->lock
);
2110 fc
->max_background
= UINT_MAX
;
2113 spin_lock(&fiq
->waitq
.lock
);
2115 list_splice_init(&fiq
->pending
, &to_end2
);
2116 list_for_each_entry(req
, &to_end2
, list
)
2117 clear_bit(FR_PENDING
, &req
->flags
);
2118 while (forget_pending(fiq
))
2119 kfree(dequeue_forget(fiq
, 1, NULL
));
2120 wake_up_all_locked(&fiq
->waitq
);
2121 spin_unlock(&fiq
->waitq
.lock
);
2122 kill_fasync(&fiq
->fasync
, SIGIO
, POLL_IN
);
2124 wake_up_all(&fc
->blocked_waitq
);
2125 spin_unlock(&fc
->lock
);
2127 while (!list_empty(&to_end1
)) {
2128 req
= list_first_entry(&to_end1
, struct fuse_req
, list
);
2129 __fuse_get_request(req
);
2130 list_del_init(&req
->list
);
2131 request_end(fc
, req
);
2133 end_requests(fc
, &to_end2
);
2135 spin_unlock(&fc
->lock
);
2138 EXPORT_SYMBOL_GPL(fuse_abort_conn
);
2140 int fuse_dev_release(struct inode
*inode
, struct file
*file
)
2142 struct fuse_dev
*fud
= fuse_get_dev(file
);
2145 struct fuse_conn
*fc
= fud
->fc
;
2146 struct fuse_pqueue
*fpq
= &fud
->pq
;
2148 WARN_ON(!list_empty(&fpq
->io
));
2149 end_requests(fc
, &fpq
->processing
);
2150 /* Are we the last open device? */
2151 if (atomic_dec_and_test(&fc
->dev_count
)) {
2152 WARN_ON(fc
->iq
.fasync
!= NULL
);
2153 fuse_abort_conn(fc
);
2159 EXPORT_SYMBOL_GPL(fuse_dev_release
);
2161 static int fuse_dev_fasync(int fd
, struct file
*file
, int on
)
2163 struct fuse_dev
*fud
= fuse_get_dev(file
);
2168 /* No locking - fasync_helper does its own locking */
2169 return fasync_helper(fd
, file
, on
, &fud
->fc
->iq
.fasync
);
2172 static int fuse_device_clone(struct fuse_conn
*fc
, struct file
*new)
2174 struct fuse_dev
*fud
;
2176 if (new->private_data
)
2179 fud
= fuse_dev_alloc(fc
);
2183 new->private_data
= fud
;
2184 atomic_inc(&fc
->dev_count
);
2189 static long fuse_dev_ioctl(struct file
*file
, unsigned int cmd
,
2194 if (cmd
== FUSE_DEV_IOC_CLONE
) {
2198 if (!get_user(oldfd
, (__u32 __user
*) arg
)) {
2199 struct file
*old
= fget(oldfd
);
2203 struct fuse_dev
*fud
= NULL
;
2206 * Check against file->f_op because CUSE
2207 * uses the same ioctl handler.
2209 if (old
->f_op
== file
->f_op
&&
2210 old
->f_cred
->user_ns
== file
->f_cred
->user_ns
)
2211 fud
= fuse_get_dev(old
);
2214 mutex_lock(&fuse_mutex
);
2215 err
= fuse_device_clone(fud
->fc
, file
);
2216 mutex_unlock(&fuse_mutex
);
2225 const struct file_operations fuse_dev_operations
= {
2226 .owner
= THIS_MODULE
,
2227 .open
= fuse_dev_open
,
2228 .llseek
= no_llseek
,
2229 .read_iter
= fuse_dev_read
,
2230 .splice_read
= fuse_dev_splice_read
,
2231 .write_iter
= fuse_dev_write
,
2232 .splice_write
= fuse_dev_splice_write
,
2233 .poll
= fuse_dev_poll
,
2234 .release
= fuse_dev_release
,
2235 .fasync
= fuse_dev_fasync
,
2236 .unlocked_ioctl
= fuse_dev_ioctl
,
2237 .compat_ioctl
= fuse_dev_ioctl
,
2239 EXPORT_SYMBOL_GPL(fuse_dev_operations
);
2241 static struct miscdevice fuse_miscdevice
= {
2242 .minor
= FUSE_MINOR
,
2244 .fops
= &fuse_dev_operations
,
2247 int __init
fuse_dev_init(void)
2250 fuse_req_cachep
= kmem_cache_create("fuse_request",
2251 sizeof(struct fuse_req
),
2253 if (!fuse_req_cachep
)
2256 err
= misc_register(&fuse_miscdevice
);
2258 goto out_cache_clean
;
2263 kmem_cache_destroy(fuse_req_cachep
);
2268 void fuse_dev_cleanup(void)
2270 misc_deregister(&fuse_miscdevice
);
2271 kmem_cache_destroy(fuse_req_cachep
);