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 READ_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_array(npages, sizeof(struct page *),
71 sizeof(struct fuse_page_desc),
75 if (!pages || !page_descs) {
78 kmem_cache_free(fuse_req_cachep, req);
82 fuse_request_init(req, pages, page_descs, npages);
87 struct fuse_req *fuse_request_alloc(unsigned npages)
89 return __fuse_request_alloc(npages, GFP_KERNEL);
91 EXPORT_SYMBOL_GPL(fuse_request_alloc);
93 struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
95 return __fuse_request_alloc(npages, GFP_NOFS);
98 void fuse_request_free(struct fuse_req *req)
100 if (req->pages != req->inline_pages) {
102 kfree(req->page_descs);
104 kmem_cache_free(fuse_req_cachep, req);
107 void __fuse_get_request(struct fuse_req *req)
109 refcount_inc(&req->count);
112 /* Must be called with > 1 refcount */
113 static void __fuse_put_request(struct fuse_req *req)
115 refcount_dec(&req->count);
118 void fuse_set_initialized(struct fuse_conn *fc)
120 /* Make sure stores before this are seen on another CPU */
125 static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
127 return !fc->initialized || (for_background && fc->blocked);
130 static void fuse_drop_waiting(struct fuse_conn *fc)
133 * lockess check of fc->connected is okay, because atomic_dec_and_test()
134 * provides a memory barrier mached with the one in fuse_wait_aborted()
135 * to ensure no wake-up is missed.
137 if (atomic_dec_and_test(&fc->num_waiting) &&
138 !READ_ONCE(fc->connected)) {
139 /* wake up aborters */
140 wake_up_all(&fc->blocked_waitq);
144 static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
147 struct fuse_req *req;
149 atomic_inc(&fc->num_waiting);
151 if (fuse_block_alloc(fc, for_background)) {
153 if (wait_event_killable_exclusive(fc->blocked_waitq,
154 !fuse_block_alloc(fc, for_background)))
157 /* Matches smp_wmb() in fuse_set_initialized() */
168 req = fuse_request_alloc(npages);
172 wake_up(&fc->blocked_waitq);
176 req->in.h.uid = from_kuid(fc->user_ns, current_fsuid());
177 req->in.h.gid = from_kgid(fc->user_ns, current_fsgid());
178 req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
180 __set_bit(FR_WAITING, &req->flags);
182 __set_bit(FR_BACKGROUND, &req->flags);
184 if (unlikely(req->in.h.uid == ((uid_t)-1) ||
185 req->in.h.gid == ((gid_t)-1))) {
186 fuse_put_request(fc, req);
187 return ERR_PTR(-EOVERFLOW);
192 fuse_drop_waiting(fc);
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 req->in.h.uid = from_kuid_munged(fc->user_ns, current_fsuid());
278 req->in.h.gid = from_kgid_munged(fc->user_ns, current_fsgid());
279 req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
281 __set_bit(FR_WAITING, &req->flags);
282 __clear_bit(FR_BACKGROUND, &req->flags);
286 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
288 if (refcount_dec_and_test(&req->count)) {
289 if (test_bit(FR_BACKGROUND, &req->flags)) {
291 * We get here in the unlikely case that a background
292 * request was allocated but not sent
294 spin_lock(&fc->lock);
296 wake_up(&fc->blocked_waitq);
297 spin_unlock(&fc->lock);
300 if (test_bit(FR_WAITING, &req->flags)) {
301 __clear_bit(FR_WAITING, &req->flags);
302 fuse_drop_waiting(fc);
305 if (req->stolen_file)
306 put_reserved_req(fc, req);
308 fuse_request_free(req);
311 EXPORT_SYMBOL_GPL(fuse_put_request);
313 static unsigned len_args(unsigned numargs, struct fuse_arg *args)
318 for (i = 0; i < numargs; i++)
319 nbytes += args[i].size;
324 static u64 fuse_get_unique(struct fuse_iqueue *fiq)
326 return ++fiq->reqctr;
329 static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
331 req->in.h.len = sizeof(struct fuse_in_header) +
332 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
333 list_add_tail(&req->list, &fiq->pending);
334 wake_up(&fiq->waitq);
335 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
338 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
339 u64 nodeid, u64 nlookup)
341 struct fuse_iqueue *fiq = &fc->iq;
343 forget->forget_one.nodeid = nodeid;
344 forget->forget_one.nlookup = nlookup;
346 spin_lock(&fiq->lock);
347 if (fiq->connected) {
348 fiq->forget_list_tail->next = forget;
349 fiq->forget_list_tail = forget;
350 wake_up(&fiq->waitq);
351 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
355 spin_unlock(&fiq->lock);
358 static void flush_bg_queue(struct fuse_conn *fc)
360 while (fc->active_background < fc->max_background &&
361 !list_empty(&fc->bg_queue)) {
362 struct fuse_req *req;
363 struct fuse_iqueue *fiq = &fc->iq;
365 req = list_entry(fc->bg_queue.next, struct fuse_req, list);
366 list_del(&req->list);
367 fc->active_background++;
368 spin_lock(&fiq->lock);
369 req->in.h.unique = fuse_get_unique(fiq);
370 queue_request(fiq, req);
371 spin_unlock(&fiq->lock);
376 * This function is called when a request is finished. Either a reply
377 * has arrived or it was aborted (and not yet sent) or some error
378 * occurred during communication with userspace, or the device file
379 * was closed. The requester thread is woken up (if still waiting),
380 * the 'end' callback is called if given, else the reference to the
381 * request is released
383 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
385 struct fuse_iqueue *fiq = &fc->iq;
387 if (test_and_set_bit(FR_FINISHED, &req->flags))
390 spin_lock(&fiq->lock);
391 list_del_init(&req->intr_entry);
392 spin_unlock(&fiq->lock);
393 WARN_ON(test_bit(FR_PENDING, &req->flags));
394 WARN_ON(test_bit(FR_SENT, &req->flags));
395 if (test_bit(FR_BACKGROUND, &req->flags)) {
396 spin_lock(&fc->lock);
397 clear_bit(FR_BACKGROUND, &req->flags);
398 if (fc->num_background == fc->max_background) {
400 wake_up(&fc->blocked_waitq);
401 } else if (!fc->blocked) {
403 * Wake up next waiter, if any. It's okay to use
404 * waitqueue_active(), as we've already synced up
405 * fc->blocked with waiters with the wake_up() call
408 if (waitqueue_active(&fc->blocked_waitq))
409 wake_up(&fc->blocked_waitq);
412 if (fc->num_background == fc->congestion_threshold && fc->sb) {
413 clear_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
414 clear_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
416 fc->num_background--;
417 fc->active_background--;
419 spin_unlock(&fc->lock);
421 wake_up(&req->waitq);
425 fuse_put_request(fc, req);
428 static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
430 spin_lock(&fiq->lock);
431 if (test_bit(FR_FINISHED, &req->flags)) {
432 spin_unlock(&fiq->lock);
435 if (list_empty(&req->intr_entry)) {
436 list_add_tail(&req->intr_entry, &fiq->interrupts);
437 wake_up(&fiq->waitq);
439 spin_unlock(&fiq->lock);
440 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
443 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
445 struct fuse_iqueue *fiq = &fc->iq;
448 if (!fc->no_interrupt) {
449 /* Any signal may interrupt this */
450 err = wait_event_interruptible(req->waitq,
451 test_bit(FR_FINISHED, &req->flags));
455 set_bit(FR_INTERRUPTED, &req->flags);
456 /* matches barrier in fuse_dev_do_read() */
457 smp_mb__after_atomic();
458 if (test_bit(FR_SENT, &req->flags))
459 queue_interrupt(fiq, req);
462 if (!test_bit(FR_FORCE, &req->flags)) {
463 /* Only fatal signals may interrupt this */
464 err = wait_event_killable(req->waitq,
465 test_bit(FR_FINISHED, &req->flags));
469 spin_lock(&fiq->lock);
470 /* Request is not yet in userspace, bail out */
471 if (test_bit(FR_PENDING, &req->flags)) {
472 list_del(&req->list);
473 spin_unlock(&fiq->lock);
474 __fuse_put_request(req);
475 req->out.h.error = -EINTR;
478 spin_unlock(&fiq->lock);
482 * Either request is already in userspace, or it was forced.
485 wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
488 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
490 struct fuse_iqueue *fiq = &fc->iq;
492 BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
493 spin_lock(&fiq->lock);
494 if (!fiq->connected) {
495 spin_unlock(&fiq->lock);
496 req->out.h.error = -ENOTCONN;
498 req->in.h.unique = fuse_get_unique(fiq);
499 queue_request(fiq, req);
500 /* acquire extra reference, since request is still needed
501 after request_end() */
502 __fuse_get_request(req);
503 spin_unlock(&fiq->lock);
505 request_wait_answer(fc, req);
506 /* Pairs with smp_wmb() in request_end() */
511 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
513 __set_bit(FR_ISREPLY, &req->flags);
514 if (!test_bit(FR_WAITING, &req->flags)) {
515 __set_bit(FR_WAITING, &req->flags);
516 atomic_inc(&fc->num_waiting);
518 __fuse_request_send(fc, req);
520 EXPORT_SYMBOL_GPL(fuse_request_send);
522 static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
524 if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS)
525 args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE;
528 switch (args->in.h.opcode) {
535 args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
539 args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
543 if (fc->minor < 12) {
544 switch (args->in.h.opcode) {
546 args->in.args[0].size = sizeof(struct fuse_open_in);
549 args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
555 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
557 struct fuse_req *req;
560 req = fuse_get_req(fc, 0);
564 /* Needs to be done after fuse_get_req() so that fc->minor is valid */
565 fuse_adjust_compat(fc, args);
567 req->in.h.opcode = args->in.h.opcode;
568 req->in.h.nodeid = args->in.h.nodeid;
569 req->in.numargs = args->in.numargs;
570 memcpy(req->in.args, args->in.args,
571 args->in.numargs * sizeof(struct fuse_in_arg));
572 req->out.argvar = args->out.argvar;
573 req->out.numargs = args->out.numargs;
574 memcpy(req->out.args, args->out.args,
575 args->out.numargs * sizeof(struct fuse_arg));
576 fuse_request_send(fc, req);
577 ret = req->out.h.error;
578 if (!ret && args->out.argvar) {
579 BUG_ON(args->out.numargs != 1);
580 ret = req->out.args[0].size;
582 fuse_put_request(fc, req);
588 * Called under fc->lock
590 * fc->connected must have been checked previously
592 void fuse_request_send_background_locked(struct fuse_conn *fc,
593 struct fuse_req *req)
595 BUG_ON(!test_bit(FR_BACKGROUND, &req->flags));
596 if (!test_bit(FR_WAITING, &req->flags)) {
597 __set_bit(FR_WAITING, &req->flags);
598 atomic_inc(&fc->num_waiting);
600 __set_bit(FR_ISREPLY, &req->flags);
601 fc->num_background++;
602 if (fc->num_background == fc->max_background)
604 if (fc->num_background == fc->congestion_threshold && fc->sb) {
605 set_bdi_congested(fc->sb->s_bdi, BLK_RW_SYNC);
606 set_bdi_congested(fc->sb->s_bdi, BLK_RW_ASYNC);
608 list_add_tail(&req->list, &fc->bg_queue);
612 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
615 spin_lock(&fc->lock);
617 fuse_request_send_background_locked(fc, req);
618 spin_unlock(&fc->lock);
620 spin_unlock(&fc->lock);
621 req->out.h.error = -ENOTCONN;
623 fuse_put_request(fc, req);
626 EXPORT_SYMBOL_GPL(fuse_request_send_background);
628 static int fuse_request_send_notify_reply(struct fuse_conn *fc,
629 struct fuse_req *req, u64 unique)
632 struct fuse_iqueue *fiq = &fc->iq;
634 __clear_bit(FR_ISREPLY, &req->flags);
635 req->in.h.unique = unique;
636 spin_lock(&fiq->lock);
637 if (fiq->connected) {
638 queue_request(fiq, req);
641 spin_unlock(&fiq->lock);
646 void fuse_force_forget(struct file *file, u64 nodeid)
648 struct inode *inode = file_inode(file);
649 struct fuse_conn *fc = get_fuse_conn(inode);
650 struct fuse_req *req;
651 struct fuse_forget_in inarg;
653 memset(&inarg, 0, sizeof(inarg));
655 req = fuse_get_req_nofail_nopages(fc, file);
656 req->in.h.opcode = FUSE_FORGET;
657 req->in.h.nodeid = nodeid;
659 req->in.args[0].size = sizeof(inarg);
660 req->in.args[0].value = &inarg;
661 __clear_bit(FR_ISREPLY, &req->flags);
662 __fuse_request_send(fc, req);
664 fuse_put_request(fc, req);
668 * Lock the request. Up to the next unlock_request() there mustn't be
669 * anything that could cause a page-fault. If the request was already
672 static int lock_request(struct fuse_req *req)
676 spin_lock(&req->waitq.lock);
677 if (test_bit(FR_ABORTED, &req->flags))
680 set_bit(FR_LOCKED, &req->flags);
681 spin_unlock(&req->waitq.lock);
687 * Unlock request. If it was aborted while locked, caller is responsible
688 * for unlocking and ending the request.
690 static int unlock_request(struct fuse_req *req)
694 spin_lock(&req->waitq.lock);
695 if (test_bit(FR_ABORTED, &req->flags))
698 clear_bit(FR_LOCKED, &req->flags);
699 spin_unlock(&req->waitq.lock);
704 struct fuse_copy_state {
706 struct fuse_req *req;
707 struct iov_iter *iter;
708 struct pipe_buffer *pipebufs;
709 struct pipe_buffer *currbuf;
710 struct pipe_inode_info *pipe;
711 unsigned long nr_segs;
715 unsigned move_pages:1;
718 static void fuse_copy_init(struct fuse_copy_state *cs, int write,
719 struct iov_iter *iter)
721 memset(cs, 0, sizeof(*cs));
726 /* Unmap and put previous page of userspace buffer */
727 static void fuse_copy_finish(struct fuse_copy_state *cs)
730 struct pipe_buffer *buf = cs->currbuf;
733 buf->len = PAGE_SIZE - cs->len;
737 flush_dcache_page(cs->pg);
738 set_page_dirty_lock(cs->pg);
746 * Get another pagefull of userspace buffer, and map it to kernel
747 * address space, and lock request
749 static int fuse_copy_fill(struct fuse_copy_state *cs)
754 err = unlock_request(cs->req);
758 fuse_copy_finish(cs);
760 struct pipe_buffer *buf = cs->pipebufs;
763 err = pipe_buf_confirm(cs->pipe, buf);
767 BUG_ON(!cs->nr_segs);
770 cs->offset = buf->offset;
775 if (cs->nr_segs == cs->pipe->buffers)
778 page = alloc_page(GFP_HIGHUSER);
795 err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off);
802 iov_iter_advance(cs->iter, err);
805 return lock_request(cs->req);
808 /* Do as much copy to/from userspace buffer as we can */
809 static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
811 unsigned ncpy = min(*size, cs->len);
813 void *pgaddr = kmap_atomic(cs->pg);
814 void *buf = pgaddr + cs->offset;
817 memcpy(buf, *val, ncpy);
819 memcpy(*val, buf, ncpy);
821 kunmap_atomic(pgaddr);
830 static int fuse_check_page(struct page *page)
832 if (page_mapcount(page) ||
833 page->mapping != NULL ||
834 (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
842 printk(KERN_WARNING "fuse: trying to steal weird page\n");
843 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);
849 static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
852 struct page *oldpage = *pagep;
853 struct page *newpage;
854 struct pipe_buffer *buf = cs->pipebufs;
857 err = unlock_request(cs->req);
861 fuse_copy_finish(cs);
863 err = pipe_buf_confirm(cs->pipe, buf);
867 BUG_ON(!cs->nr_segs);
873 if (cs->len != PAGE_SIZE)
876 if (pipe_buf_steal(cs->pipe, buf) != 0)
881 if (!PageUptodate(newpage))
882 SetPageUptodate(newpage);
884 ClearPageMappedToDisk(newpage);
886 if (fuse_check_page(newpage) != 0)
887 goto out_fallback_unlock;
890 * This is a new and locked page, it shouldn't be mapped or
891 * have any special flags on it
893 if (WARN_ON(page_mapped(oldpage)))
894 goto out_fallback_unlock;
895 if (WARN_ON(page_has_private(oldpage)))
896 goto out_fallback_unlock;
897 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
898 goto out_fallback_unlock;
899 if (WARN_ON(PageMlocked(oldpage)))
900 goto out_fallback_unlock;
902 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
904 unlock_page(newpage);
910 if (!(buf->flags & PIPE_BUF_FLAG_LRU))
911 lru_cache_add_file(newpage);
914 * Release while we have extra ref on stolen page. Otherwise
915 * anon_pipe_buf_release() might think the page can be reused.
917 pipe_buf_release(cs->pipe, buf);
920 spin_lock(&cs->req->waitq.lock);
921 if (test_bit(FR_ABORTED, &cs->req->flags))
925 spin_unlock(&cs->req->waitq.lock);
928 unlock_page(newpage);
933 unlock_page(oldpage);
934 /* Drop ref for ap->pages[] array */
940 /* Drop ref obtained in this function */
945 unlock_page(newpage);
948 cs->offset = buf->offset;
950 err = lock_request(cs->req);
957 static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
958 unsigned offset, unsigned count)
960 struct pipe_buffer *buf;
963 if (cs->nr_segs == cs->pipe->buffers)
967 err = unlock_request(cs->req);
973 fuse_copy_finish(cs);
977 buf->offset = offset;
988 * Copy a page in the request to/from the userspace buffer. Must be
991 static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
992 unsigned offset, unsigned count, int zeroing)
995 struct page *page = *pagep;
997 if (page && zeroing && count < PAGE_SIZE)
998 clear_highpage(page);
1001 if (cs->write && cs->pipebufs && page) {
1003 * Can't control lifetime of pipe buffers, so always
1006 if (cs->req->user_pages) {
1007 err = fuse_copy_fill(cs);
1011 return fuse_ref_page(cs, page, offset, count);
1013 } else if (!cs->len) {
1014 if (cs->move_pages && page &&
1015 offset == 0 && count == PAGE_SIZE) {
1016 err = fuse_try_move_page(cs, pagep);
1020 err = fuse_copy_fill(cs);
1026 void *mapaddr = kmap_atomic(page);
1027 void *buf = mapaddr + offset;
1028 offset += fuse_copy_do(cs, &buf, &count);
1029 kunmap_atomic(mapaddr);
1031 offset += fuse_copy_do(cs, NULL, &count);
1033 if (page && !cs->write)
1034 flush_dcache_page(page);
1038 /* Copy pages in the request to/from userspace buffer */
1039 static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
1043 struct fuse_req *req = cs->req;
1045 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
1047 unsigned offset = req->page_descs[i].offset;
1048 unsigned count = min(nbytes, req->page_descs[i].length);
1050 err = fuse_copy_page(cs, &req->pages[i], offset, count,
1060 /* Copy a single argument in the request to/from userspace buffer */
1061 static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
1065 int err = fuse_copy_fill(cs);
1069 fuse_copy_do(cs, &val, &size);
1074 /* Copy request arguments to/from userspace buffer */
1075 static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
1076 unsigned argpages, struct fuse_arg *args,
1082 for (i = 0; !err && i < numargs; i++) {
1083 struct fuse_arg *arg = &args[i];
1084 if (i == numargs - 1 && argpages)
1085 err = fuse_copy_pages(cs, arg->size, zeroing);
1087 err = fuse_copy_one(cs, arg->value, arg->size);
1092 static int forget_pending(struct fuse_iqueue *fiq)
1094 return fiq->forget_list_head.next != NULL;
1097 static int request_pending(struct fuse_iqueue *fiq)
1099 return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) ||
1100 forget_pending(fiq);
1104 * Transfer an interrupt request to userspace
1106 * Unlike other requests this is assembled on demand, without a need
1107 * to allocate a separate fuse_req structure.
1109 * Called with fiq->lock held, releases it
1111 static int fuse_read_interrupt(struct fuse_iqueue *fiq,
1112 struct fuse_copy_state *cs,
1113 size_t nbytes, struct fuse_req *req)
1114 __releases(fiq->lock)
1116 struct fuse_in_header ih;
1117 struct fuse_interrupt_in arg;
1118 unsigned reqsize = sizeof(ih) + sizeof(arg);
1121 list_del_init(&req->intr_entry);
1122 req->intr_unique = fuse_get_unique(fiq);
1123 memset(&ih, 0, sizeof(ih));
1124 memset(&arg, 0, sizeof(arg));
1126 ih.opcode = FUSE_INTERRUPT;
1127 ih.unique = req->intr_unique;
1128 arg.unique = req->in.h.unique;
1130 spin_unlock(&fiq->lock);
1131 if (nbytes < reqsize)
1134 err = fuse_copy_one(cs, &ih, sizeof(ih));
1136 err = fuse_copy_one(cs, &arg, sizeof(arg));
1137 fuse_copy_finish(cs);
1139 return err ? err : reqsize;
1142 static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
1146 struct fuse_forget_link *head = fiq->forget_list_head.next;
1147 struct fuse_forget_link **newhead = &head;
1150 for (count = 0; *newhead != NULL && count < max; count++)
1151 newhead = &(*newhead)->next;
1153 fiq->forget_list_head.next = *newhead;
1155 if (fiq->forget_list_head.next == NULL)
1156 fiq->forget_list_tail = &fiq->forget_list_head;
1164 static int fuse_read_single_forget(struct fuse_iqueue *fiq,
1165 struct fuse_copy_state *cs,
1167 __releases(fiq->lock)
1170 struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
1171 struct fuse_forget_in arg = {
1172 .nlookup = forget->forget_one.nlookup,
1174 struct fuse_in_header ih = {
1175 .opcode = FUSE_FORGET,
1176 .nodeid = forget->forget_one.nodeid,
1177 .unique = fuse_get_unique(fiq),
1178 .len = sizeof(ih) + sizeof(arg),
1181 spin_unlock(&fiq->lock);
1183 if (nbytes < ih.len)
1186 err = fuse_copy_one(cs, &ih, sizeof(ih));
1188 err = fuse_copy_one(cs, &arg, sizeof(arg));
1189 fuse_copy_finish(cs);
1197 static int fuse_read_batch_forget(struct fuse_iqueue *fiq,
1198 struct fuse_copy_state *cs, size_t nbytes)
1199 __releases(fiq->lock)
1202 unsigned max_forgets;
1204 struct fuse_forget_link *head;
1205 struct fuse_batch_forget_in arg = { .count = 0 };
1206 struct fuse_in_header ih = {
1207 .opcode = FUSE_BATCH_FORGET,
1208 .unique = fuse_get_unique(fiq),
1209 .len = sizeof(ih) + sizeof(arg),
1212 if (nbytes < ih.len) {
1213 spin_unlock(&fiq->lock);
1217 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
1218 head = dequeue_forget(fiq, max_forgets, &count);
1219 spin_unlock(&fiq->lock);
1222 ih.len += count * sizeof(struct fuse_forget_one);
1223 err = fuse_copy_one(cs, &ih, sizeof(ih));
1225 err = fuse_copy_one(cs, &arg, sizeof(arg));
1228 struct fuse_forget_link *forget = head;
1231 err = fuse_copy_one(cs, &forget->forget_one,
1232 sizeof(forget->forget_one));
1234 head = forget->next;
1238 fuse_copy_finish(cs);
1246 static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq,
1247 struct fuse_copy_state *cs,
1249 __releases(fiq->lock)
1251 if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
1252 return fuse_read_single_forget(fiq, cs, nbytes);
1254 return fuse_read_batch_forget(fiq, cs, nbytes);
1258 * Read a single request into the userspace filesystem's buffer. This
1259 * function waits until a request is available, then removes it from
1260 * the pending list and copies request data to userspace buffer. If
1261 * no reply is needed (FORGET) or request has been aborted or there
1262 * was an error during the copying then it's finished by calling
1263 * request_end(). Otherwise add it to the processing list, and set
1266 static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file,
1267 struct fuse_copy_state *cs, size_t nbytes)
1270 struct fuse_conn *fc = fud->fc;
1271 struct fuse_iqueue *fiq = &fc->iq;
1272 struct fuse_pqueue *fpq = &fud->pq;
1273 struct fuse_req *req;
1279 spin_lock(&fiq->lock);
1280 if (!fiq->connected || request_pending(fiq))
1282 spin_unlock(&fiq->lock);
1284 if (file->f_flags & O_NONBLOCK)
1286 err = wait_event_interruptible_exclusive(fiq->waitq,
1287 !fiq->connected || request_pending(fiq));
1292 if (!fiq->connected) {
1293 err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV;
1297 if (!list_empty(&fiq->interrupts)) {
1298 req = list_entry(fiq->interrupts.next, struct fuse_req,
1300 return fuse_read_interrupt(fiq, cs, nbytes, req);
1303 if (forget_pending(fiq)) {
1304 if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
1305 return fuse_read_forget(fc, fiq, cs, nbytes);
1307 if (fiq->forget_batch <= -8)
1308 fiq->forget_batch = 16;
1311 req = list_entry(fiq->pending.next, struct fuse_req, list);
1312 clear_bit(FR_PENDING, &req->flags);
1313 list_del_init(&req->list);
1314 spin_unlock(&fiq->lock);
1317 reqsize = in->h.len;
1319 /* If request is too large, reply with an error and restart the read */
1320 if (nbytes < reqsize) {
1321 req->out.h.error = -EIO;
1322 /* SETXATTR is special, since it may contain too large data */
1323 if (in->h.opcode == FUSE_SETXATTR)
1324 req->out.h.error = -E2BIG;
1325 request_end(fc, req);
1328 spin_lock(&fpq->lock);
1330 * Must not put request on fpq->io queue after having been shut down by
1333 if (!fpq->connected) {
1334 req->out.h.error = err = -ECONNABORTED;
1338 list_add(&req->list, &fpq->io);
1339 spin_unlock(&fpq->lock);
1341 err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1343 err = fuse_copy_args(cs, in->numargs, in->argpages,
1344 (struct fuse_arg *) in->args, 0);
1345 fuse_copy_finish(cs);
1346 spin_lock(&fpq->lock);
1347 clear_bit(FR_LOCKED, &req->flags);
1348 if (!fpq->connected) {
1349 err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV;
1353 req->out.h.error = -EIO;
1356 if (!test_bit(FR_ISREPLY, &req->flags)) {
1360 list_move_tail(&req->list, &fpq->processing);
1361 __fuse_get_request(req);
1362 set_bit(FR_SENT, &req->flags);
1363 spin_unlock(&fpq->lock);
1364 /* matches barrier in request_wait_answer() */
1365 smp_mb__after_atomic();
1366 if (test_bit(FR_INTERRUPTED, &req->flags))
1367 queue_interrupt(fiq, req);
1368 fuse_put_request(fc, req);
1373 if (!test_bit(FR_PRIVATE, &req->flags))
1374 list_del_init(&req->list);
1375 spin_unlock(&fpq->lock);
1376 request_end(fc, req);
1380 spin_unlock(&fiq->lock);
1384 static int fuse_dev_open(struct inode *inode, struct file *file)
1387 * The fuse device's file's private_data is used to hold
1388 * the fuse_conn(ection) when it is mounted, and is used to
1389 * keep track of whether the file has been mounted already.
1391 file->private_data = NULL;
1395 static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
1397 struct fuse_copy_state cs;
1398 struct file *file = iocb->ki_filp;
1399 struct fuse_dev *fud = fuse_get_dev(file);
1404 if (!iter_is_iovec(to))
1407 fuse_copy_init(&cs, 1, to);
1409 return fuse_dev_do_read(fud, file, &cs, iov_iter_count(to));
1412 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1413 struct pipe_inode_info *pipe,
1414 size_t len, unsigned int flags)
1418 struct pipe_buffer *bufs;
1419 struct fuse_copy_state cs;
1420 struct fuse_dev *fud = fuse_get_dev(in);
1425 bufs = kvmalloc_array(pipe->buffers, sizeof(struct pipe_buffer),
1430 fuse_copy_init(&cs, 1, NULL);
1433 ret = fuse_dev_do_read(fud, in, &cs, len);
1437 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1442 for (ret = total = 0; page_nr < cs.nr_segs; total += ret) {
1444 * Need to be careful about this. Having buf->ops in module
1445 * code can Oops if the buffer persists after module unload.
1447 bufs[page_nr].ops = &nosteal_pipe_buf_ops;
1448 bufs[page_nr].flags = 0;
1449 ret = add_to_pipe(pipe, &bufs[page_nr++]);
1450 if (unlikely(ret < 0))
1456 for (; page_nr < cs.nr_segs; page_nr++)
1457 put_page(bufs[page_nr].page);
1463 static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1464 struct fuse_copy_state *cs)
1466 struct fuse_notify_poll_wakeup_out outarg;
1469 if (size != sizeof(outarg))
1472 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1476 fuse_copy_finish(cs);
1477 return fuse_notify_poll_wakeup(fc, &outarg);
1480 fuse_copy_finish(cs);
1484 static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1485 struct fuse_copy_state *cs)
1487 struct fuse_notify_inval_inode_out outarg;
1490 if (size != sizeof(outarg))
1493 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1496 fuse_copy_finish(cs);
1498 down_read(&fc->killsb);
1501 err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1502 outarg.off, outarg.len);
1504 up_read(&fc->killsb);
1508 fuse_copy_finish(cs);
1512 static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1513 struct fuse_copy_state *cs)
1515 struct fuse_notify_inval_entry_out outarg;
1520 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1525 if (size < sizeof(outarg))
1528 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1532 err = -ENAMETOOLONG;
1533 if (outarg.namelen > FUSE_NAME_MAX)
1537 if (size != sizeof(outarg) + outarg.namelen + 1)
1541 name.len = outarg.namelen;
1542 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1545 fuse_copy_finish(cs);
1546 buf[outarg.namelen] = 0;
1548 down_read(&fc->killsb);
1551 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1552 up_read(&fc->killsb);
1558 fuse_copy_finish(cs);
1562 static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1563 struct fuse_copy_state *cs)
1565 struct fuse_notify_delete_out outarg;
1570 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1575 if (size < sizeof(outarg))
1578 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1582 err = -ENAMETOOLONG;
1583 if (outarg.namelen > FUSE_NAME_MAX)
1587 if (size != sizeof(outarg) + outarg.namelen + 1)
1591 name.len = outarg.namelen;
1592 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1595 fuse_copy_finish(cs);
1596 buf[outarg.namelen] = 0;
1598 down_read(&fc->killsb);
1601 err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1602 outarg.child, &name);
1603 up_read(&fc->killsb);
1609 fuse_copy_finish(cs);
1613 static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1614 struct fuse_copy_state *cs)
1616 struct fuse_notify_store_out outarg;
1617 struct inode *inode;
1618 struct address_space *mapping;
1622 unsigned int offset;
1628 if (size < sizeof(outarg))
1631 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1636 if (size - sizeof(outarg) != outarg.size)
1639 nodeid = outarg.nodeid;
1641 down_read(&fc->killsb);
1647 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1651 mapping = inode->i_mapping;
1652 index = outarg.offset >> PAGE_SHIFT;
1653 offset = outarg.offset & ~PAGE_MASK;
1654 file_size = i_size_read(inode);
1655 end = outarg.offset + outarg.size;
1656 if (end > file_size) {
1658 fuse_write_update_size(inode, file_size);
1664 unsigned int this_num;
1667 page = find_or_create_page(mapping, index,
1668 mapping_gfp_mask(mapping));
1672 this_num = min_t(unsigned, num, PAGE_SIZE - offset);
1673 err = fuse_copy_page(cs, &page, offset, this_num, 0);
1674 if (!err && offset == 0 &&
1675 (this_num == PAGE_SIZE || file_size == end))
1676 SetPageUptodate(page);
1693 up_read(&fc->killsb);
1695 fuse_copy_finish(cs);
1699 static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
1701 release_pages(req->pages, req->num_pages);
1704 static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1705 struct fuse_notify_retrieve_out *outarg)
1708 struct address_space *mapping = inode->i_mapping;
1709 struct fuse_req *req;
1713 unsigned int offset;
1714 size_t total_len = 0;
1717 offset = outarg->offset & ~PAGE_MASK;
1718 file_size = i_size_read(inode);
1720 num = min(outarg->size, fc->max_write);
1721 if (outarg->offset > file_size)
1723 else if (outarg->offset + num > file_size)
1724 num = file_size - outarg->offset;
1726 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1727 num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
1729 req = fuse_get_req(fc, num_pages);
1731 return PTR_ERR(req);
1733 req->in.h.opcode = FUSE_NOTIFY_REPLY;
1734 req->in.h.nodeid = outarg->nodeid;
1735 req->in.numargs = 2;
1736 req->in.argpages = 1;
1737 req->end = fuse_retrieve_end;
1739 index = outarg->offset >> PAGE_SHIFT;
1741 while (num && req->num_pages < num_pages) {
1743 unsigned int this_num;
1745 page = find_get_page(mapping, index);
1749 this_num = min_t(unsigned, num, PAGE_SIZE - offset);
1750 req->pages[req->num_pages] = page;
1751 req->page_descs[req->num_pages].offset = offset;
1752 req->page_descs[req->num_pages].length = this_num;
1757 total_len += this_num;
1760 req->misc.retrieve_in.offset = outarg->offset;
1761 req->misc.retrieve_in.size = total_len;
1762 req->in.args[0].size = sizeof(req->misc.retrieve_in);
1763 req->in.args[0].value = &req->misc.retrieve_in;
1764 req->in.args[1].size = total_len;
1766 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1768 fuse_retrieve_end(fc, req);
1769 fuse_put_request(fc, req);
1775 static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1776 struct fuse_copy_state *cs)
1778 struct fuse_notify_retrieve_out outarg;
1779 struct inode *inode;
1783 if (size != sizeof(outarg))
1786 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1790 fuse_copy_finish(cs);
1792 down_read(&fc->killsb);
1795 u64 nodeid = outarg.nodeid;
1797 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1799 err = fuse_retrieve(fc, inode, &outarg);
1803 up_read(&fc->killsb);
1808 fuse_copy_finish(cs);
1812 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1813 unsigned int size, struct fuse_copy_state *cs)
1815 /* Don't try to move pages (yet) */
1819 case FUSE_NOTIFY_POLL:
1820 return fuse_notify_poll(fc, size, cs);
1822 case FUSE_NOTIFY_INVAL_INODE:
1823 return fuse_notify_inval_inode(fc, size, cs);
1825 case FUSE_NOTIFY_INVAL_ENTRY:
1826 return fuse_notify_inval_entry(fc, size, cs);
1828 case FUSE_NOTIFY_STORE:
1829 return fuse_notify_store(fc, size, cs);
1831 case FUSE_NOTIFY_RETRIEVE:
1832 return fuse_notify_retrieve(fc, size, cs);
1834 case FUSE_NOTIFY_DELETE:
1835 return fuse_notify_delete(fc, size, cs);
1838 fuse_copy_finish(cs);
1843 /* Look up request on processing list by unique ID */
1844 static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
1846 struct fuse_req *req;
1848 list_for_each_entry(req, &fpq->processing, list) {
1849 if (req->in.h.unique == unique || req->intr_unique == unique)
1855 static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1858 unsigned reqsize = sizeof(struct fuse_out_header);
1861 return nbytes != reqsize ? -EINVAL : 0;
1863 reqsize += len_args(out->numargs, out->args);
1865 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1867 else if (reqsize > nbytes) {
1868 struct fuse_arg *lastarg = &out->args[out->numargs-1];
1869 unsigned diffsize = reqsize - nbytes;
1870 if (diffsize > lastarg->size)
1872 lastarg->size -= diffsize;
1874 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1879 * Write a single reply to a request. First the header is copied from
1880 * the write buffer. The request is then searched on the processing
1881 * list by the unique ID found in the header. If found, then remove
1882 * it from the list and copy the rest of the buffer to the request.
1883 * The request is finished by calling request_end()
1885 static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
1886 struct fuse_copy_state *cs, size_t nbytes)
1889 struct fuse_conn *fc = fud->fc;
1890 struct fuse_pqueue *fpq = &fud->pq;
1891 struct fuse_req *req;
1892 struct fuse_out_header oh;
1894 if (nbytes < sizeof(struct fuse_out_header))
1897 err = fuse_copy_one(cs, &oh, sizeof(oh));
1902 if (oh.len != nbytes)
1906 * Zero oh.unique indicates unsolicited notification message
1907 * and error contains notification code.
1910 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
1911 return err ? err : nbytes;
1915 if (oh.error <= -512 || oh.error > 0)
1918 spin_lock(&fpq->lock);
1920 if (!fpq->connected)
1923 req = request_find(fpq, oh.unique);
1927 /* Is it an interrupt reply? */
1928 if (req->intr_unique == oh.unique) {
1929 __fuse_get_request(req);
1930 spin_unlock(&fpq->lock);
1933 if (nbytes != sizeof(struct fuse_out_header)) {
1934 fuse_put_request(fc, req);
1938 if (oh.error == -ENOSYS)
1939 fc->no_interrupt = 1;
1940 else if (oh.error == -EAGAIN)
1941 queue_interrupt(&fc->iq, req);
1942 fuse_put_request(fc, req);
1944 fuse_copy_finish(cs);
1948 clear_bit(FR_SENT, &req->flags);
1949 list_move(&req->list, &fpq->io);
1951 set_bit(FR_LOCKED, &req->flags);
1952 spin_unlock(&fpq->lock);
1954 if (!req->out.page_replace)
1957 err = copy_out_args(cs, &req->out, nbytes);
1958 fuse_copy_finish(cs);
1960 spin_lock(&fpq->lock);
1961 clear_bit(FR_LOCKED, &req->flags);
1962 if (!fpq->connected)
1965 req->out.h.error = -EIO;
1966 if (!test_bit(FR_PRIVATE, &req->flags))
1967 list_del_init(&req->list);
1968 spin_unlock(&fpq->lock);
1970 request_end(fc, req);
1972 return err ? err : nbytes;
1975 spin_unlock(&fpq->lock);
1977 fuse_copy_finish(cs);
1981 static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
1983 struct fuse_copy_state cs;
1984 struct fuse_dev *fud = fuse_get_dev(iocb->ki_filp);
1989 if (!iter_is_iovec(from))
1992 fuse_copy_init(&cs, 0, from);
1994 return fuse_dev_do_write(fud, &cs, iov_iter_count(from));
1997 static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1998 struct file *out, loff_t *ppos,
1999 size_t len, unsigned int flags)
2003 struct pipe_buffer *bufs;
2004 struct fuse_copy_state cs;
2005 struct fuse_dev *fud;
2009 fud = fuse_get_dev(out);
2015 bufs = kvmalloc_array(pipe->nrbufs, sizeof(struct pipe_buffer),
2024 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
2025 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
2033 struct pipe_buffer *ibuf;
2034 struct pipe_buffer *obuf;
2036 BUG_ON(nbuf >= pipe->buffers);
2037 BUG_ON(!pipe->nrbufs);
2038 ibuf = &pipe->bufs[pipe->curbuf];
2041 if (rem >= ibuf->len) {
2044 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
2047 if (!pipe_buf_get(pipe, ibuf))
2051 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
2053 ibuf->offset += obuf->len;
2054 ibuf->len -= obuf->len;
2061 fuse_copy_init(&cs, 0, NULL);
2066 if (flags & SPLICE_F_MOVE)
2069 ret = fuse_dev_do_write(fud, &cs, len);
2073 for (idx = 0; idx < nbuf; idx++) {
2074 struct pipe_buffer *buf = &bufs[idx];
2077 pipe_buf_release(pipe, buf);
2085 static __poll_t fuse_dev_poll(struct file *file, poll_table *wait)
2087 __poll_t mask = EPOLLOUT | EPOLLWRNORM;
2088 struct fuse_iqueue *fiq;
2089 struct fuse_dev *fud = fuse_get_dev(file);
2095 poll_wait(file, &fiq->waitq, wait);
2097 spin_lock(&fiq->lock);
2098 if (!fiq->connected)
2100 else if (request_pending(fiq))
2101 mask |= EPOLLIN | EPOLLRDNORM;
2102 spin_unlock(&fiq->lock);
2108 * Abort all requests on the given list (pending or processing)
2110 * This function releases and reacquires fc->lock
2112 static void end_requests(struct fuse_conn *fc, struct list_head *head)
2114 while (!list_empty(head)) {
2115 struct fuse_req *req;
2116 req = list_entry(head->next, struct fuse_req, list);
2117 req->out.h.error = -ECONNABORTED;
2118 clear_bit(FR_SENT, &req->flags);
2119 list_del_init(&req->list);
2120 request_end(fc, req);
2124 static void end_polls(struct fuse_conn *fc)
2128 p = rb_first(&fc->polled_files);
2131 struct fuse_file *ff;
2132 ff = rb_entry(p, struct fuse_file, polled_node);
2133 wake_up_interruptible_all(&ff->poll_wait);
2140 * Abort all requests.
2142 * Emergency exit in case of a malicious or accidental deadlock, or just a hung
2145 * The same effect is usually achievable through killing the filesystem daemon
2146 * and all users of the filesystem. The exception is the combination of an
2147 * asynchronous request and the tricky deadlock (see
2148 * Documentation/filesystems/fuse.txt).
2150 * Aborting requests under I/O goes as follows: 1: Separate out unlocked
2151 * requests, they should be finished off immediately. Locked requests will be
2152 * finished after unlock; see unlock_request(). 2: Finish off the unlocked
2153 * requests. It is possible that some request will finish before we can. This
2154 * is OK, the request will in that case be removed from the list before we touch
2157 void fuse_abort_conn(struct fuse_conn *fc, bool is_abort)
2159 struct fuse_iqueue *fiq = &fc->iq;
2161 spin_lock(&fc->lock);
2162 if (fc->connected) {
2163 struct fuse_dev *fud;
2164 struct fuse_req *req, *next;
2169 fc->aborted = is_abort;
2170 fuse_set_initialized(fc);
2171 list_for_each_entry(fud, &fc->devices, entry) {
2172 struct fuse_pqueue *fpq = &fud->pq;
2174 spin_lock(&fpq->lock);
2176 list_for_each_entry_safe(req, next, &fpq->io, list) {
2177 req->out.h.error = -ECONNABORTED;
2178 spin_lock(&req->waitq.lock);
2179 set_bit(FR_ABORTED, &req->flags);
2180 if (!test_bit(FR_LOCKED, &req->flags)) {
2181 set_bit(FR_PRIVATE, &req->flags);
2182 __fuse_get_request(req);
2183 list_move(&req->list, &to_end);
2185 spin_unlock(&req->waitq.lock);
2187 list_splice_tail_init(&fpq->processing, &to_end);
2188 spin_unlock(&fpq->lock);
2190 fc->max_background = UINT_MAX;
2193 spin_lock(&fiq->lock);
2195 list_for_each_entry(req, &fiq->pending, list)
2196 clear_bit(FR_PENDING, &req->flags);
2197 list_splice_tail_init(&fiq->pending, &to_end);
2198 while (forget_pending(fiq))
2199 kfree(dequeue_forget(fiq, 1, NULL));
2200 wake_up_all(&fiq->waitq);
2201 spin_unlock(&fiq->lock);
2202 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
2204 wake_up_all(&fc->blocked_waitq);
2205 spin_unlock(&fc->lock);
2207 end_requests(fc, &to_end);
2209 spin_unlock(&fc->lock);
2212 EXPORT_SYMBOL_GPL(fuse_abort_conn);
2214 void fuse_wait_aborted(struct fuse_conn *fc)
2216 /* matches implicit memory barrier in fuse_drop_waiting() */
2218 wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0);
2221 int fuse_dev_release(struct inode *inode, struct file *file)
2223 struct fuse_dev *fud = fuse_get_dev(file);
2226 struct fuse_conn *fc = fud->fc;
2227 struct fuse_pqueue *fpq = &fud->pq;
2230 spin_lock(&fpq->lock);
2231 WARN_ON(!list_empty(&fpq->io));
2232 list_splice_init(&fpq->processing, &to_end);
2233 spin_unlock(&fpq->lock);
2235 end_requests(fc, &to_end);
2237 /* Are we the last open device? */
2238 if (atomic_dec_and_test(&fc->dev_count)) {
2239 WARN_ON(fc->iq.fasync != NULL);
2240 fuse_abort_conn(fc, false);
2246 EXPORT_SYMBOL_GPL(fuse_dev_release);
2248 static int fuse_dev_fasync(int fd, struct file *file, int on)
2250 struct fuse_dev *fud = fuse_get_dev(file);
2255 /* No locking - fasync_helper does its own locking */
2256 return fasync_helper(fd, file, on, &fud->fc->iq.fasync);
2259 static int fuse_device_clone(struct fuse_conn *fc, struct file *new)
2261 struct fuse_dev *fud;
2263 if (new->private_data)
2266 fud = fuse_dev_alloc(fc);
2270 new->private_data = fud;
2271 atomic_inc(&fc->dev_count);
2276 static long fuse_dev_ioctl(struct file *file, unsigned int cmd,
2281 if (cmd == FUSE_DEV_IOC_CLONE) {
2285 if (!get_user(oldfd, (__u32 __user *) arg)) {
2286 struct file *old = fget(oldfd);
2290 struct fuse_dev *fud = NULL;
2293 * Check against file->f_op because CUSE
2294 * uses the same ioctl handler.
2296 if (old->f_op == file->f_op &&
2297 old->f_cred->user_ns == file->f_cred->user_ns)
2298 fud = fuse_get_dev(old);
2301 mutex_lock(&fuse_mutex);
2302 err = fuse_device_clone(fud->fc, file);
2303 mutex_unlock(&fuse_mutex);
2312 const struct file_operations fuse_dev_operations = {
2313 .owner = THIS_MODULE,
2314 .open = fuse_dev_open,
2315 .llseek = no_llseek,
2316 .read_iter = fuse_dev_read,
2317 .splice_read = fuse_dev_splice_read,
2318 .write_iter = fuse_dev_write,
2319 .splice_write = fuse_dev_splice_write,
2320 .poll = fuse_dev_poll,
2321 .release = fuse_dev_release,
2322 .fasync = fuse_dev_fasync,
2323 .unlocked_ioctl = fuse_dev_ioctl,
2324 .compat_ioctl = fuse_dev_ioctl,
2326 EXPORT_SYMBOL_GPL(fuse_dev_operations);
2328 static struct miscdevice fuse_miscdevice = {
2329 .minor = FUSE_MINOR,
2331 .fops = &fuse_dev_operations,
2334 int __init fuse_dev_init(void)
2337 fuse_req_cachep = kmem_cache_create("fuse_request",
2338 sizeof(struct fuse_req),
2340 if (!fuse_req_cachep)
2343 err = misc_register(&fuse_miscdevice);
2345 goto out_cache_clean;
2350 kmem_cache_destroy(fuse_req_cachep);
2355 void fuse_dev_cleanup(void)
2357 misc_deregister(&fuse_miscdevice);
2358 kmem_cache_destroy(fuse_req_cachep);