2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2006 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>
20 MODULE_ALIAS_MISCDEV(FUSE_MINOR
);
22 static struct kmem_cache
*fuse_req_cachep
;
24 static struct fuse_conn
*fuse_get_conn(struct file
*file
)
27 * Lockless access is OK, because file->private data is set
28 * once during mount and is valid until the file is released.
30 return file
->private_data
;
33 static void fuse_request_init(struct fuse_req
*req
)
35 memset(req
, 0, sizeof(*req
));
36 INIT_LIST_HEAD(&req
->list
);
37 INIT_LIST_HEAD(&req
->intr_entry
);
38 init_waitqueue_head(&req
->waitq
);
39 atomic_set(&req
->count
, 1);
42 struct fuse_req
*fuse_request_alloc(void)
44 struct fuse_req
*req
= kmem_cache_alloc(fuse_req_cachep
, GFP_KERNEL
);
46 fuse_request_init(req
);
50 void fuse_request_free(struct fuse_req
*req
)
52 kmem_cache_free(fuse_req_cachep
, req
);
55 static void block_sigs(sigset_t
*oldset
)
59 siginitsetinv(&mask
, sigmask(SIGKILL
));
60 sigprocmask(SIG_BLOCK
, &mask
, oldset
);
63 static void restore_sigs(sigset_t
*oldset
)
65 sigprocmask(SIG_SETMASK
, oldset
, NULL
);
68 static void __fuse_get_request(struct fuse_req
*req
)
70 atomic_inc(&req
->count
);
73 /* Must be called with > 1 refcount */
74 static void __fuse_put_request(struct fuse_req
*req
)
76 BUG_ON(atomic_read(&req
->count
) < 2);
77 atomic_dec(&req
->count
);
80 static void fuse_req_init_context(struct fuse_req
*req
)
82 req
->in
.h
.uid
= current
->fsuid
;
83 req
->in
.h
.gid
= current
->fsgid
;
84 req
->in
.h
.pid
= current
->pid
;
87 struct fuse_req
*fuse_get_req(struct fuse_conn
*fc
)
94 atomic_inc(&fc
->num_waiting
);
96 intr
= wait_event_interruptible(fc
->blocked_waitq
, !fc
->blocked
);
97 restore_sigs(&oldset
);
106 req
= fuse_request_alloc();
111 fuse_req_init_context(req
);
116 atomic_dec(&fc
->num_waiting
);
121 * Return request in fuse_file->reserved_req. However that may
122 * currently be in use. If that is the case, wait for it to become
125 static struct fuse_req
*get_reserved_req(struct fuse_conn
*fc
,
128 struct fuse_req
*req
= NULL
;
129 struct fuse_file
*ff
= file
->private_data
;
132 wait_event(fc
->reserved_req_waitq
, ff
->reserved_req
);
133 spin_lock(&fc
->lock
);
134 if (ff
->reserved_req
) {
135 req
= ff
->reserved_req
;
136 ff
->reserved_req
= NULL
;
138 req
->stolen_file
= file
;
140 spin_unlock(&fc
->lock
);
147 * Put stolen request back into fuse_file->reserved_req
149 static void put_reserved_req(struct fuse_conn
*fc
, struct fuse_req
*req
)
151 struct file
*file
= req
->stolen_file
;
152 struct fuse_file
*ff
= file
->private_data
;
154 spin_lock(&fc
->lock
);
155 fuse_request_init(req
);
156 BUG_ON(ff
->reserved_req
);
157 ff
->reserved_req
= req
;
158 wake_up_all(&fc
->reserved_req_waitq
);
159 spin_unlock(&fc
->lock
);
164 * Gets a requests for a file operation, always succeeds
166 * This is used for sending the FLUSH request, which must get to
167 * userspace, due to POSIX locks which may need to be unlocked.
169 * If allocation fails due to OOM, use the reserved request in
172 * This is very unlikely to deadlock accidentally, since the
173 * filesystem should not have it's own file open. If deadlock is
174 * intentional, it can still be broken by "aborting" the filesystem.
176 struct fuse_req
*fuse_get_req_nofail(struct fuse_conn
*fc
, struct file
*file
)
178 struct fuse_req
*req
;
180 atomic_inc(&fc
->num_waiting
);
181 wait_event(fc
->blocked_waitq
, !fc
->blocked
);
182 req
= fuse_request_alloc();
184 req
= get_reserved_req(fc
, file
);
186 fuse_req_init_context(req
);
191 void fuse_put_request(struct fuse_conn
*fc
, struct fuse_req
*req
)
193 if (atomic_dec_and_test(&req
->count
)) {
195 atomic_dec(&fc
->num_waiting
);
197 if (req
->stolen_file
)
198 put_reserved_req(fc
, req
);
200 fuse_request_free(req
);
205 * This function is called when a request is finished. Either a reply
206 * has arrived or it was aborted (and not yet sent) or some error
207 * occurred during communication with userspace, or the device file
208 * was closed. The requester thread is woken up (if still waiting),
209 * the 'end' callback is called if given, else the reference to the
210 * request is released
212 * Called with fc->lock, unlocks it
214 static void request_end(struct fuse_conn
*fc
, struct fuse_req
*req
)
217 void (*end
) (struct fuse_conn
*, struct fuse_req
*) = req
->end
;
219 list_del(&req
->list
);
220 list_del(&req
->intr_entry
);
221 req
->state
= FUSE_REQ_FINISHED
;
222 if (req
->background
) {
223 if (fc
->num_background
== FUSE_MAX_BACKGROUND
) {
225 wake_up_all(&fc
->blocked_waitq
);
227 if (fc
->num_background
== FUSE_CONGESTION_THRESHOLD
) {
228 clear_bdi_congested(&fc
->bdi
, READ
);
229 clear_bdi_congested(&fc
->bdi
, WRITE
);
231 fc
->num_background
--;
233 spin_unlock(&fc
->lock
);
235 mntput(req
->vfsmount
);
236 wake_up(&req
->waitq
);
240 fuse_put_request(fc
, req
);
243 static void wait_answer_interruptible(struct fuse_conn
*fc
,
244 struct fuse_req
*req
)
246 if (signal_pending(current
))
249 spin_unlock(&fc
->lock
);
250 wait_event_interruptible(req
->waitq
, req
->state
== FUSE_REQ_FINISHED
);
251 spin_lock(&fc
->lock
);
254 static void queue_interrupt(struct fuse_conn
*fc
, struct fuse_req
*req
)
256 list_add_tail(&req
->intr_entry
, &fc
->interrupts
);
258 kill_fasync(&fc
->fasync
, SIGIO
, POLL_IN
);
261 /* Called with fc->lock held. Releases, and then reacquires it. */
262 static void request_wait_answer(struct fuse_conn
*fc
, struct fuse_req
*req
)
264 if (!fc
->no_interrupt
) {
265 /* Any signal may interrupt this */
266 wait_answer_interruptible(fc
, req
);
270 if (req
->state
== FUSE_REQ_FINISHED
)
273 req
->interrupted
= 1;
274 if (req
->state
== FUSE_REQ_SENT
)
275 queue_interrupt(fc
, req
);
279 spin_unlock(&fc
->lock
);
280 wait_event(req
->waitq
, req
->state
== FUSE_REQ_FINISHED
);
281 spin_lock(&fc
->lock
);
285 /* Only fatal signals may interrupt this */
287 wait_answer_interruptible(fc
, req
);
288 restore_sigs(&oldset
);
293 if (req
->state
== FUSE_REQ_FINISHED
)
296 req
->out
.h
.error
= -EINTR
;
301 /* This is uninterruptible sleep, because data is
302 being copied to/from the buffers of req. During
303 locked state, there mustn't be any filesystem
304 operation (e.g. page fault), since that could lead
306 spin_unlock(&fc
->lock
);
307 wait_event(req
->waitq
, !req
->locked
);
308 spin_lock(&fc
->lock
);
310 if (req
->state
== FUSE_REQ_PENDING
) {
311 list_del(&req
->list
);
312 __fuse_put_request(req
);
313 } else if (req
->state
== FUSE_REQ_SENT
) {
314 spin_unlock(&fc
->lock
);
315 wait_event(req
->waitq
, req
->state
== FUSE_REQ_FINISHED
);
316 spin_lock(&fc
->lock
);
320 static unsigned len_args(unsigned numargs
, struct fuse_arg
*args
)
325 for (i
= 0; i
< numargs
; i
++)
326 nbytes
+= args
[i
].size
;
331 static u64
fuse_get_unique(struct fuse_conn
*fc
)
334 /* zero is special */
341 static void queue_request(struct fuse_conn
*fc
, struct fuse_req
*req
)
343 req
->in
.h
.unique
= fuse_get_unique(fc
);
344 req
->in
.h
.len
= sizeof(struct fuse_in_header
) +
345 len_args(req
->in
.numargs
, (struct fuse_arg
*) req
->in
.args
);
346 list_add_tail(&req
->list
, &fc
->pending
);
347 req
->state
= FUSE_REQ_PENDING
;
350 atomic_inc(&fc
->num_waiting
);
353 kill_fasync(&fc
->fasync
, SIGIO
, POLL_IN
);
356 void request_send(struct fuse_conn
*fc
, struct fuse_req
*req
)
359 spin_lock(&fc
->lock
);
361 req
->out
.h
.error
= -ENOTCONN
;
362 else if (fc
->conn_error
)
363 req
->out
.h
.error
= -ECONNREFUSED
;
365 queue_request(fc
, req
);
366 /* acquire extra reference, since request is still needed
367 after request_end() */
368 __fuse_get_request(req
);
370 request_wait_answer(fc
, req
);
372 spin_unlock(&fc
->lock
);
375 static void request_send_nowait(struct fuse_conn
*fc
, struct fuse_req
*req
)
377 spin_lock(&fc
->lock
);
380 fc
->num_background
++;
381 if (fc
->num_background
== FUSE_MAX_BACKGROUND
)
383 if (fc
->num_background
== FUSE_CONGESTION_THRESHOLD
) {
384 set_bdi_congested(&fc
->bdi
, READ
);
385 set_bdi_congested(&fc
->bdi
, WRITE
);
388 queue_request(fc
, req
);
389 spin_unlock(&fc
->lock
);
391 req
->out
.h
.error
= -ENOTCONN
;
392 request_end(fc
, req
);
396 void request_send_noreply(struct fuse_conn
*fc
, struct fuse_req
*req
)
399 request_send_nowait(fc
, req
);
402 void request_send_background(struct fuse_conn
*fc
, struct fuse_req
*req
)
405 request_send_nowait(fc
, req
);
409 * Lock the request. Up to the next unlock_request() there mustn't be
410 * anything that could cause a page-fault. If the request was already
413 static int lock_request(struct fuse_conn
*fc
, struct fuse_req
*req
)
417 spin_lock(&fc
->lock
);
422 spin_unlock(&fc
->lock
);
428 * Unlock request. If it was aborted during being locked, the
429 * requester thread is currently waiting for it to be unlocked, so
432 static void unlock_request(struct fuse_conn
*fc
, struct fuse_req
*req
)
435 spin_lock(&fc
->lock
);
438 wake_up(&req
->waitq
);
439 spin_unlock(&fc
->lock
);
443 struct fuse_copy_state
{
444 struct fuse_conn
*fc
;
446 struct fuse_req
*req
;
447 const struct iovec
*iov
;
448 unsigned long nr_segs
;
449 unsigned long seglen
;
457 static void fuse_copy_init(struct fuse_copy_state
*cs
, struct fuse_conn
*fc
,
458 int write
, struct fuse_req
*req
,
459 const struct iovec
*iov
, unsigned long nr_segs
)
461 memset(cs
, 0, sizeof(*cs
));
466 cs
->nr_segs
= nr_segs
;
469 /* Unmap and put previous page of userspace buffer */
470 static void fuse_copy_finish(struct fuse_copy_state
*cs
)
473 kunmap_atomic(cs
->mapaddr
, KM_USER0
);
475 flush_dcache_page(cs
->pg
);
476 set_page_dirty_lock(cs
->pg
);
484 * Get another pagefull of userspace buffer, and map it to kernel
485 * address space, and lock request
487 static int fuse_copy_fill(struct fuse_copy_state
*cs
)
489 unsigned long offset
;
492 unlock_request(cs
->fc
, cs
->req
);
493 fuse_copy_finish(cs
);
495 BUG_ON(!cs
->nr_segs
);
496 cs
->seglen
= cs
->iov
[0].iov_len
;
497 cs
->addr
= (unsigned long) cs
->iov
[0].iov_base
;
501 down_read(¤t
->mm
->mmap_sem
);
502 err
= get_user_pages(current
, current
->mm
, cs
->addr
, 1, cs
->write
, 0,
504 up_read(¤t
->mm
->mmap_sem
);
508 offset
= cs
->addr
% PAGE_SIZE
;
509 cs
->mapaddr
= kmap_atomic(cs
->pg
, KM_USER0
);
510 cs
->buf
= cs
->mapaddr
+ offset
;
511 cs
->len
= min(PAGE_SIZE
- offset
, cs
->seglen
);
512 cs
->seglen
-= cs
->len
;
515 return lock_request(cs
->fc
, cs
->req
);
518 /* Do as much copy to/from userspace buffer as we can */
519 static int fuse_copy_do(struct fuse_copy_state
*cs
, void **val
, unsigned *size
)
521 unsigned ncpy
= min(*size
, cs
->len
);
524 memcpy(cs
->buf
, *val
, ncpy
);
526 memcpy(*val
, cs
->buf
, ncpy
);
536 * Copy a page in the request to/from the userspace buffer. Must be
539 static int fuse_copy_page(struct fuse_copy_state
*cs
, struct page
*page
,
540 unsigned offset
, unsigned count
, int zeroing
)
542 if (page
&& zeroing
&& count
< PAGE_SIZE
) {
543 void *mapaddr
= kmap_atomic(page
, KM_USER1
);
544 memset(mapaddr
, 0, PAGE_SIZE
);
545 kunmap_atomic(mapaddr
, KM_USER1
);
549 if (!cs
->len
&& (err
= fuse_copy_fill(cs
)))
552 void *mapaddr
= kmap_atomic(page
, KM_USER1
);
553 void *buf
= mapaddr
+ offset
;
554 offset
+= fuse_copy_do(cs
, &buf
, &count
);
555 kunmap_atomic(mapaddr
, KM_USER1
);
557 offset
+= fuse_copy_do(cs
, NULL
, &count
);
559 if (page
&& !cs
->write
)
560 flush_dcache_page(page
);
564 /* Copy pages in the request to/from userspace buffer */
565 static int fuse_copy_pages(struct fuse_copy_state
*cs
, unsigned nbytes
,
569 struct fuse_req
*req
= cs
->req
;
570 unsigned offset
= req
->page_offset
;
571 unsigned count
= min(nbytes
, (unsigned) PAGE_SIZE
- offset
);
573 for (i
= 0; i
< req
->num_pages
&& (nbytes
|| zeroing
); i
++) {
574 struct page
*page
= req
->pages
[i
];
575 int err
= fuse_copy_page(cs
, page
, offset
, count
, zeroing
);
580 count
= min(nbytes
, (unsigned) PAGE_SIZE
);
586 /* Copy a single argument in the request to/from userspace buffer */
587 static int fuse_copy_one(struct fuse_copy_state
*cs
, void *val
, unsigned size
)
591 if (!cs
->len
&& (err
= fuse_copy_fill(cs
)))
593 fuse_copy_do(cs
, &val
, &size
);
598 /* Copy request arguments to/from userspace buffer */
599 static int fuse_copy_args(struct fuse_copy_state
*cs
, unsigned numargs
,
600 unsigned argpages
, struct fuse_arg
*args
,
606 for (i
= 0; !err
&& i
< numargs
; i
++) {
607 struct fuse_arg
*arg
= &args
[i
];
608 if (i
== numargs
- 1 && argpages
)
609 err
= fuse_copy_pages(cs
, arg
->size
, zeroing
);
611 err
= fuse_copy_one(cs
, arg
->value
, arg
->size
);
616 static int request_pending(struct fuse_conn
*fc
)
618 return !list_empty(&fc
->pending
) || !list_empty(&fc
->interrupts
);
621 /* Wait until a request is available on the pending list */
622 static void request_wait(struct fuse_conn
*fc
)
624 DECLARE_WAITQUEUE(wait
, current
);
626 add_wait_queue_exclusive(&fc
->waitq
, &wait
);
627 while (fc
->connected
&& !request_pending(fc
)) {
628 set_current_state(TASK_INTERRUPTIBLE
);
629 if (signal_pending(current
))
632 spin_unlock(&fc
->lock
);
634 spin_lock(&fc
->lock
);
636 set_current_state(TASK_RUNNING
);
637 remove_wait_queue(&fc
->waitq
, &wait
);
641 * Transfer an interrupt request to userspace
643 * Unlike other requests this is assembled on demand, without a need
644 * to allocate a separate fuse_req structure.
646 * Called with fc->lock held, releases it
648 static int fuse_read_interrupt(struct fuse_conn
*fc
, struct fuse_req
*req
,
649 const struct iovec
*iov
, unsigned long nr_segs
)
652 struct fuse_copy_state cs
;
653 struct fuse_in_header ih
;
654 struct fuse_interrupt_in arg
;
655 unsigned reqsize
= sizeof(ih
) + sizeof(arg
);
658 list_del_init(&req
->intr_entry
);
659 req
->intr_unique
= fuse_get_unique(fc
);
660 memset(&ih
, 0, sizeof(ih
));
661 memset(&arg
, 0, sizeof(arg
));
663 ih
.opcode
= FUSE_INTERRUPT
;
664 ih
.unique
= req
->intr_unique
;
665 arg
.unique
= req
->in
.h
.unique
;
667 spin_unlock(&fc
->lock
);
668 if (iov_length(iov
, nr_segs
) < reqsize
)
671 fuse_copy_init(&cs
, fc
, 1, NULL
, iov
, nr_segs
);
672 err
= fuse_copy_one(&cs
, &ih
, sizeof(ih
));
674 err
= fuse_copy_one(&cs
, &arg
, sizeof(arg
));
675 fuse_copy_finish(&cs
);
677 return err
? err
: reqsize
;
681 * Read a single request into the userspace filesystem's buffer. This
682 * function waits until a request is available, then removes it from
683 * the pending list and copies request data to userspace buffer. If
684 * no reply is needed (FORGET) or request has been aborted or there
685 * was an error during the copying then it's finished by calling
686 * request_end(). Otherwise add it to the processing list, and set
689 static ssize_t
fuse_dev_read(struct kiocb
*iocb
, const struct iovec
*iov
,
690 unsigned long nr_segs
, loff_t pos
)
693 struct fuse_req
*req
;
695 struct fuse_copy_state cs
;
697 struct file
*file
= iocb
->ki_filp
;
698 struct fuse_conn
*fc
= fuse_get_conn(file
);
703 spin_lock(&fc
->lock
);
705 if ((file
->f_flags
& O_NONBLOCK
) && fc
->connected
&&
706 !request_pending(fc
))
714 if (!request_pending(fc
))
717 if (!list_empty(&fc
->interrupts
)) {
718 req
= list_entry(fc
->interrupts
.next
, struct fuse_req
,
720 return fuse_read_interrupt(fc
, req
, iov
, nr_segs
);
723 req
= list_entry(fc
->pending
.next
, struct fuse_req
, list
);
724 req
->state
= FUSE_REQ_READING
;
725 list_move(&req
->list
, &fc
->io
);
729 /* If request is too large, reply with an error and restart the read */
730 if (iov_length(iov
, nr_segs
) < reqsize
) {
731 req
->out
.h
.error
= -EIO
;
732 /* SETXATTR is special, since it may contain too large data */
733 if (in
->h
.opcode
== FUSE_SETXATTR
)
734 req
->out
.h
.error
= -E2BIG
;
735 request_end(fc
, req
);
738 spin_unlock(&fc
->lock
);
739 fuse_copy_init(&cs
, fc
, 1, req
, iov
, nr_segs
);
740 err
= fuse_copy_one(&cs
, &in
->h
, sizeof(in
->h
));
742 err
= fuse_copy_args(&cs
, in
->numargs
, in
->argpages
,
743 (struct fuse_arg
*) in
->args
, 0);
744 fuse_copy_finish(&cs
);
745 spin_lock(&fc
->lock
);
747 if (!err
&& req
->aborted
)
751 req
->out
.h
.error
= -EIO
;
752 request_end(fc
, req
);
756 request_end(fc
, req
);
758 req
->state
= FUSE_REQ_SENT
;
759 list_move_tail(&req
->list
, &fc
->processing
);
760 if (req
->interrupted
)
761 queue_interrupt(fc
, req
);
762 spin_unlock(&fc
->lock
);
767 spin_unlock(&fc
->lock
);
771 /* Look up request on processing list by unique ID */
772 static struct fuse_req
*request_find(struct fuse_conn
*fc
, u64 unique
)
774 struct list_head
*entry
;
776 list_for_each(entry
, &fc
->processing
) {
777 struct fuse_req
*req
;
778 req
= list_entry(entry
, struct fuse_req
, list
);
779 if (req
->in
.h
.unique
== unique
|| req
->intr_unique
== unique
)
785 static int copy_out_args(struct fuse_copy_state
*cs
, struct fuse_out
*out
,
788 unsigned reqsize
= sizeof(struct fuse_out_header
);
791 return nbytes
!= reqsize
? -EINVAL
: 0;
793 reqsize
+= len_args(out
->numargs
, out
->args
);
795 if (reqsize
< nbytes
|| (reqsize
> nbytes
&& !out
->argvar
))
797 else if (reqsize
> nbytes
) {
798 struct fuse_arg
*lastarg
= &out
->args
[out
->numargs
-1];
799 unsigned diffsize
= reqsize
- nbytes
;
800 if (diffsize
> lastarg
->size
)
802 lastarg
->size
-= diffsize
;
804 return fuse_copy_args(cs
, out
->numargs
, out
->argpages
, out
->args
,
809 * Write a single reply to a request. First the header is copied from
810 * the write buffer. The request is then searched on the processing
811 * list by the unique ID found in the header. If found, then remove
812 * it from the list and copy the rest of the buffer to the request.
813 * The request is finished by calling request_end()
815 static ssize_t
fuse_dev_write(struct kiocb
*iocb
, const struct iovec
*iov
,
816 unsigned long nr_segs
, loff_t pos
)
819 unsigned nbytes
= iov_length(iov
, nr_segs
);
820 struct fuse_req
*req
;
821 struct fuse_out_header oh
;
822 struct fuse_copy_state cs
;
823 struct fuse_conn
*fc
= fuse_get_conn(iocb
->ki_filp
);
827 fuse_copy_init(&cs
, fc
, 0, NULL
, iov
, nr_segs
);
828 if (nbytes
< sizeof(struct fuse_out_header
))
831 err
= fuse_copy_one(&cs
, &oh
, sizeof(oh
));
835 if (!oh
.unique
|| oh
.error
<= -1000 || oh
.error
> 0 ||
839 spin_lock(&fc
->lock
);
844 req
= request_find(fc
, oh
.unique
);
849 spin_unlock(&fc
->lock
);
850 fuse_copy_finish(&cs
);
851 spin_lock(&fc
->lock
);
852 request_end(fc
, req
);
855 /* Is it an interrupt reply? */
856 if (req
->intr_unique
== oh
.unique
) {
858 if (nbytes
!= sizeof(struct fuse_out_header
))
861 if (oh
.error
== -ENOSYS
)
862 fc
->no_interrupt
= 1;
863 else if (oh
.error
== -EAGAIN
)
864 queue_interrupt(fc
, req
);
866 spin_unlock(&fc
->lock
);
867 fuse_copy_finish(&cs
);
871 req
->state
= FUSE_REQ_WRITING
;
872 list_move(&req
->list
, &fc
->io
);
876 spin_unlock(&fc
->lock
);
878 err
= copy_out_args(&cs
, &req
->out
, nbytes
);
879 fuse_copy_finish(&cs
);
881 spin_lock(&fc
->lock
);
886 } else if (!req
->aborted
)
887 req
->out
.h
.error
= -EIO
;
888 request_end(fc
, req
);
890 return err
? err
: nbytes
;
893 spin_unlock(&fc
->lock
);
895 fuse_copy_finish(&cs
);
899 static unsigned fuse_dev_poll(struct file
*file
, poll_table
*wait
)
901 unsigned mask
= POLLOUT
| POLLWRNORM
;
902 struct fuse_conn
*fc
= fuse_get_conn(file
);
906 poll_wait(file
, &fc
->waitq
, wait
);
908 spin_lock(&fc
->lock
);
911 else if (request_pending(fc
))
912 mask
|= POLLIN
| POLLRDNORM
;
913 spin_unlock(&fc
->lock
);
919 * Abort all requests on the given list (pending or processing)
921 * This function releases and reacquires fc->lock
923 static void end_requests(struct fuse_conn
*fc
, struct list_head
*head
)
925 while (!list_empty(head
)) {
926 struct fuse_req
*req
;
927 req
= list_entry(head
->next
, struct fuse_req
, list
);
928 req
->out
.h
.error
= -ECONNABORTED
;
929 request_end(fc
, req
);
930 spin_lock(&fc
->lock
);
935 * Abort requests under I/O
937 * The requests are set to aborted and finished, and the request
938 * waiter is woken up. This will make request_wait_answer() wait
939 * until the request is unlocked and then return.
941 * If the request is asynchronous, then the end function needs to be
942 * called after waiting for the request to be unlocked (if it was
945 static void end_io_requests(struct fuse_conn
*fc
)
947 while (!list_empty(&fc
->io
)) {
948 struct fuse_req
*req
=
949 list_entry(fc
->io
.next
, struct fuse_req
, list
);
950 void (*end
) (struct fuse_conn
*, struct fuse_req
*) = req
->end
;
953 req
->out
.h
.error
= -ECONNABORTED
;
954 req
->state
= FUSE_REQ_FINISHED
;
955 list_del_init(&req
->list
);
956 wake_up(&req
->waitq
);
959 /* The end function will consume this reference */
960 __fuse_get_request(req
);
961 spin_unlock(&fc
->lock
);
962 wait_event(req
->waitq
, !req
->locked
);
964 spin_lock(&fc
->lock
);
970 * Abort all requests.
972 * Emergency exit in case of a malicious or accidental deadlock, or
973 * just a hung filesystem.
975 * The same effect is usually achievable through killing the
976 * filesystem daemon and all users of the filesystem. The exception
977 * is the combination of an asynchronous request and the tricky
978 * deadlock (see Documentation/filesystems/fuse.txt).
980 * During the aborting, progression of requests from the pending and
981 * processing lists onto the io list, and progression of new requests
982 * onto the pending list is prevented by req->connected being false.
984 * Progression of requests under I/O to the processing list is
985 * prevented by the req->aborted flag being true for these requests.
986 * For this reason requests on the io list must be aborted first.
988 void fuse_abort_conn(struct fuse_conn
*fc
)
990 spin_lock(&fc
->lock
);
995 end_requests(fc
, &fc
->pending
);
996 end_requests(fc
, &fc
->processing
);
997 wake_up_all(&fc
->waitq
);
998 wake_up_all(&fc
->blocked_waitq
);
999 kill_fasync(&fc
->fasync
, SIGIO
, POLL_IN
);
1001 spin_unlock(&fc
->lock
);
1004 static int fuse_dev_release(struct inode
*inode
, struct file
*file
)
1006 struct fuse_conn
*fc
= fuse_get_conn(file
);
1008 spin_lock(&fc
->lock
);
1010 end_requests(fc
, &fc
->pending
);
1011 end_requests(fc
, &fc
->processing
);
1012 spin_unlock(&fc
->lock
);
1013 fasync_helper(-1, file
, 0, &fc
->fasync
);
1020 static int fuse_dev_fasync(int fd
, struct file
*file
, int on
)
1022 struct fuse_conn
*fc
= fuse_get_conn(file
);
1026 /* No locking - fasync_helper does its own locking */
1027 return fasync_helper(fd
, file
, on
, &fc
->fasync
);
1030 const struct file_operations fuse_dev_operations
= {
1031 .owner
= THIS_MODULE
,
1032 .llseek
= no_llseek
,
1033 .read
= do_sync_read
,
1034 .aio_read
= fuse_dev_read
,
1035 .write
= do_sync_write
,
1036 .aio_write
= fuse_dev_write
,
1037 .poll
= fuse_dev_poll
,
1038 .release
= fuse_dev_release
,
1039 .fasync
= fuse_dev_fasync
,
1042 static struct miscdevice fuse_miscdevice
= {
1043 .minor
= FUSE_MINOR
,
1045 .fops
= &fuse_dev_operations
,
1048 int __init
fuse_dev_init(void)
1051 fuse_req_cachep
= kmem_cache_create("fuse_request",
1052 sizeof(struct fuse_req
),
1054 if (!fuse_req_cachep
)
1057 err
= misc_register(&fuse_miscdevice
);
1059 goto out_cache_clean
;
1064 kmem_cache_destroy(fuse_req_cachep
);
1069 void fuse_dev_cleanup(void)
1071 misc_deregister(&fuse_miscdevice
);
1072 kmem_cache_destroy(fuse_req_cachep
);