2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
5 This program can be distributed under the terms of the GNU GPL.
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/poll.h>
14 #include <linux/uio.h>
15 #include <linux/miscdevice.h>
16 #include <linux/pagemap.h>
17 #include <linux/file.h>
18 #include <linux/slab.h>
19 #include <linux/pipe_fs_i.h>
20 #include <linux/swap.h>
21 #include <linux/splice.h>
23 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
24 MODULE_ALIAS("devname:fuse");
26 static struct kmem_cache *fuse_req_cachep;
28 static struct fuse_conn *fuse_get_conn(struct file *file)
31 * Lockless access is OK, because file->private data is set
32 * once during mount and is valid until the file is released.
34 return file->private_data;
37 static void fuse_request_init(struct fuse_req *req, struct page **pages,
38 struct fuse_page_desc *page_descs,
41 memset(req, 0, sizeof(*req));
42 memset(pages, 0, sizeof(*pages) * npages);
43 memset(page_descs, 0, sizeof(*page_descs) * npages);
44 INIT_LIST_HEAD(&req->list);
45 INIT_LIST_HEAD(&req->intr_entry);
46 init_waitqueue_head(&req->waitq);
47 atomic_set(&req->count, 1);
49 req->page_descs = page_descs;
50 req->max_pages = npages;
51 __set_bit(FR_PENDING, &req->flags);
54 static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
56 struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags);
59 struct fuse_page_desc *page_descs;
61 if (npages <= FUSE_REQ_INLINE_PAGES) {
62 pages = req->inline_pages;
63 page_descs = req->inline_page_descs;
65 pages = kmalloc(sizeof(struct page *) * npages, flags);
66 page_descs = kmalloc(sizeof(struct fuse_page_desc) *
70 if (!pages || !page_descs) {
73 kmem_cache_free(fuse_req_cachep, req);
77 fuse_request_init(req, pages, page_descs, npages);
82 struct fuse_req *fuse_request_alloc(unsigned npages)
84 return __fuse_request_alloc(npages, GFP_KERNEL);
86 EXPORT_SYMBOL_GPL(fuse_request_alloc);
88 struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
90 return __fuse_request_alloc(npages, GFP_NOFS);
93 void fuse_request_free(struct fuse_req *req)
95 if (req->pages != req->inline_pages) {
97 kfree(req->page_descs);
99 kmem_cache_free(fuse_req_cachep, req);
102 static void block_sigs(sigset_t *oldset)
106 siginitsetinv(&mask, sigmask(SIGKILL));
107 sigprocmask(SIG_BLOCK, &mask, oldset);
110 static void restore_sigs(sigset_t *oldset)
112 sigprocmask(SIG_SETMASK, oldset, NULL);
115 void __fuse_get_request(struct fuse_req *req)
117 atomic_inc(&req->count);
120 /* Must be called with > 1 refcount */
121 static void __fuse_put_request(struct fuse_req *req)
123 BUG_ON(atomic_read(&req->count) < 2);
124 atomic_dec(&req->count);
127 static void fuse_req_init_context(struct fuse_req *req)
129 req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid());
130 req->in.h.gid = from_kgid_munged(&init_user_ns, current_fsgid());
131 req->in.h.pid = current->pid;
134 void fuse_set_initialized(struct fuse_conn *fc)
136 /* Make sure stores before this are seen on another CPU */
141 static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
143 return !fc->initialized || (for_background && fc->blocked);
146 static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
149 struct fuse_req *req;
151 atomic_inc(&fc->num_waiting);
153 if (fuse_block_alloc(fc, for_background)) {
158 intr = wait_event_interruptible_exclusive(fc->blocked_waitq,
159 !fuse_block_alloc(fc, for_background));
160 restore_sigs(&oldset);
165 /* Matches smp_wmb() in fuse_set_initialized() */
176 req = fuse_request_alloc(npages);
180 wake_up(&fc->blocked_waitq);
184 fuse_req_init_context(req);
185 __set_bit(FR_WAITING, &req->flags);
187 __set_bit(FR_BACKGROUND, &req->flags);
192 atomic_dec(&fc->num_waiting);
196 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
198 return __fuse_get_req(fc, npages, false);
200 EXPORT_SYMBOL_GPL(fuse_get_req);
202 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
205 return __fuse_get_req(fc, npages, true);
207 EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
210 * Return request in fuse_file->reserved_req. However that may
211 * currently be in use. If that is the case, wait for it to become
214 static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
217 struct fuse_req *req = NULL;
218 struct fuse_file *ff = file->private_data;
221 wait_event(fc->reserved_req_waitq, ff->reserved_req);
222 spin_lock(&fc->lock);
223 if (ff->reserved_req) {
224 req = ff->reserved_req;
225 ff->reserved_req = NULL;
226 req->stolen_file = get_file(file);
228 spin_unlock(&fc->lock);
235 * Put stolen request back into fuse_file->reserved_req
237 static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
239 struct file *file = req->stolen_file;
240 struct fuse_file *ff = file->private_data;
242 spin_lock(&fc->lock);
243 fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
244 BUG_ON(ff->reserved_req);
245 ff->reserved_req = req;
246 wake_up_all(&fc->reserved_req_waitq);
247 spin_unlock(&fc->lock);
252 * Gets a requests for a file operation, always succeeds
254 * This is used for sending the FLUSH request, which must get to
255 * userspace, due to POSIX locks which may need to be unlocked.
257 * If allocation fails due to OOM, use the reserved request in
260 * This is very unlikely to deadlock accidentally, since the
261 * filesystem should not have it's own file open. If deadlock is
262 * intentional, it can still be broken by "aborting" the filesystem.
264 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
267 struct fuse_req *req;
269 atomic_inc(&fc->num_waiting);
270 wait_event(fc->blocked_waitq, fc->initialized);
271 /* Matches smp_wmb() in fuse_set_initialized() */
273 req = fuse_request_alloc(0);
275 req = get_reserved_req(fc, file);
277 fuse_req_init_context(req);
278 __set_bit(FR_WAITING, &req->flags);
279 __clear_bit(FR_BACKGROUND, &req->flags);
283 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
285 if (atomic_dec_and_test(&req->count)) {
286 if (test_bit(FR_BACKGROUND, &req->flags)) {
288 * We get here in the unlikely case that a background
289 * request was allocated but not sent
291 spin_lock(&fc->lock);
293 wake_up(&fc->blocked_waitq);
294 spin_unlock(&fc->lock);
297 if (test_bit(FR_WAITING, &req->flags)) {
298 __clear_bit(FR_WAITING, &req->flags);
299 atomic_dec(&fc->num_waiting);
302 if (req->stolen_file)
303 put_reserved_req(fc, req);
305 fuse_request_free(req);
308 EXPORT_SYMBOL_GPL(fuse_put_request);
310 static unsigned len_args(unsigned numargs, struct fuse_arg *args)
315 for (i = 0; i < numargs; i++)
316 nbytes += args[i].size;
321 static u64 fuse_get_unique(struct fuse_iqueue *fiq)
323 return ++fiq->reqctr;
326 static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
328 req->in.h.len = sizeof(struct fuse_in_header) +
329 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
330 list_add_tail(&req->list, &fiq->pending);
331 wake_up_locked(&fiq->waitq);
332 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
335 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
336 u64 nodeid, u64 nlookup)
338 struct fuse_iqueue *fiq = &fc->iq;
340 forget->forget_one.nodeid = nodeid;
341 forget->forget_one.nlookup = nlookup;
343 spin_lock(&fiq->waitq.lock);
344 if (fiq->connected) {
345 fiq->forget_list_tail->next = forget;
346 fiq->forget_list_tail = forget;
347 wake_up_locked(&fiq->waitq);
348 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
352 spin_unlock(&fiq->waitq.lock);
355 static void flush_bg_queue(struct fuse_conn *fc)
357 while (fc->active_background < fc->max_background &&
358 !list_empty(&fc->bg_queue)) {
359 struct fuse_req *req;
360 struct fuse_iqueue *fiq = &fc->iq;
362 req = list_entry(fc->bg_queue.next, struct fuse_req, list);
363 list_del(&req->list);
364 fc->active_background++;
365 spin_lock(&fiq->waitq.lock);
366 req->in.h.unique = fuse_get_unique(fiq);
367 queue_request(fiq, req);
368 spin_unlock(&fiq->waitq.lock);
373 * This function is called when a request is finished. Either a reply
374 * has arrived or it was aborted (and not yet sent) or some error
375 * occurred during communication with userspace, or the device file
376 * was closed. The requester thread is woken up (if still waiting),
377 * the 'end' callback is called if given, else the reference to the
378 * request is released
380 * Called with fc->lock, unlocks it
382 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
385 struct fuse_iqueue *fiq = &fc->iq;
386 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
388 spin_lock(&fiq->waitq.lock);
389 list_del_init(&req->intr_entry);
390 spin_unlock(&fiq->waitq.lock);
391 WARN_ON(test_bit(FR_PENDING, &req->flags));
392 WARN_ON(test_bit(FR_SENT, &req->flags));
394 set_bit(FR_FINISHED, &req->flags);
395 if (test_bit(FR_BACKGROUND, &req->flags)) {
396 clear_bit(FR_BACKGROUND, &req->flags);
397 if (fc->num_background == fc->max_background)
400 /* Wake up next waiter, if any */
401 if (!fc->blocked && waitqueue_active(&fc->blocked_waitq))
402 wake_up(&fc->blocked_waitq);
404 if (fc->num_background == fc->congestion_threshold &&
405 fc->connected && fc->bdi_initialized) {
406 clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
407 clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
409 fc->num_background--;
410 fc->active_background--;
413 spin_unlock(&fc->lock);
414 wake_up(&req->waitq);
417 fuse_put_request(fc, req);
420 static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
422 spin_lock(&fiq->waitq.lock);
423 if (list_empty(&req->intr_entry)) {
424 list_add_tail(&req->intr_entry, &fiq->interrupts);
425 wake_up_locked(&fiq->waitq);
427 spin_unlock(&fiq->waitq.lock);
428 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
431 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
433 struct fuse_iqueue *fiq = &fc->iq;
436 if (!fc->no_interrupt) {
437 /* Any signal may interrupt this */
438 err = wait_event_interruptible(req->waitq,
439 test_bit(FR_FINISHED, &req->flags));
443 set_bit(FR_INTERRUPTED, &req->flags);
444 /* matches barrier in fuse_dev_do_read() */
445 smp_mb__after_atomic();
446 if (test_bit(FR_SENT, &req->flags))
447 queue_interrupt(fiq, req);
450 if (!test_bit(FR_FORCE, &req->flags)) {
453 /* Only fatal signals may interrupt this */
455 err = wait_event_interruptible(req->waitq,
456 test_bit(FR_FINISHED, &req->flags));
457 restore_sigs(&oldset);
462 spin_lock(&fiq->waitq.lock);
463 /* Request is not yet in userspace, bail out */
464 if (test_bit(FR_PENDING, &req->flags)) {
465 list_del(&req->list);
466 spin_unlock(&fiq->waitq.lock);
467 __fuse_put_request(req);
468 req->out.h.error = -EINTR;
471 spin_unlock(&fiq->waitq.lock);
475 * Either request is already in userspace, or it was forced.
478 wait_event(req->waitq, test_bit(FR_FINISHED, &req->flags));
481 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
483 struct fuse_iqueue *fiq = &fc->iq;
485 BUG_ON(test_bit(FR_BACKGROUND, &req->flags));
486 spin_lock(&fiq->waitq.lock);
487 if (!fiq->connected) {
488 spin_unlock(&fiq->waitq.lock);
489 req->out.h.error = -ENOTCONN;
491 req->in.h.unique = fuse_get_unique(fiq);
492 queue_request(fiq, req);
493 /* acquire extra reference, since request is still needed
494 after request_end() */
495 __fuse_get_request(req);
496 spin_unlock(&fiq->waitq.lock);
498 request_wait_answer(fc, req);
499 /* Pairs with smp_wmb() in request_end() */
504 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
506 __set_bit(FR_ISREPLY, &req->flags);
507 if (!test_bit(FR_WAITING, &req->flags)) {
508 __set_bit(FR_WAITING, &req->flags);
509 atomic_inc(&fc->num_waiting);
511 __fuse_request_send(fc, req);
513 EXPORT_SYMBOL_GPL(fuse_request_send);
515 static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
517 if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS)
518 args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE;
521 switch (args->in.h.opcode) {
528 args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
532 args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
536 if (fc->minor < 12) {
537 switch (args->in.h.opcode) {
539 args->in.args[0].size = sizeof(struct fuse_open_in);
542 args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
548 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
550 struct fuse_req *req;
553 req = fuse_get_req(fc, 0);
557 /* Needs to be done after fuse_get_req() so that fc->minor is valid */
558 fuse_adjust_compat(fc, args);
560 req->in.h.opcode = args->in.h.opcode;
561 req->in.h.nodeid = args->in.h.nodeid;
562 req->in.numargs = args->in.numargs;
563 memcpy(req->in.args, args->in.args,
564 args->in.numargs * sizeof(struct fuse_in_arg));
565 req->out.argvar = args->out.argvar;
566 req->out.numargs = args->out.numargs;
567 memcpy(req->out.args, args->out.args,
568 args->out.numargs * sizeof(struct fuse_arg));
569 fuse_request_send(fc, req);
570 ret = req->out.h.error;
571 if (!ret && args->out.argvar) {
572 BUG_ON(args->out.numargs != 1);
573 ret = req->out.args[0].size;
575 fuse_put_request(fc, req);
581 * Called under fc->lock
583 * fc->connected must have been checked previously
585 void fuse_request_send_background_locked(struct fuse_conn *fc,
586 struct fuse_req *req)
588 BUG_ON(!test_bit(FR_BACKGROUND, &req->flags));
589 if (!test_bit(FR_WAITING, &req->flags)) {
590 __set_bit(FR_WAITING, &req->flags);
591 atomic_inc(&fc->num_waiting);
593 __set_bit(FR_ISREPLY, &req->flags);
594 fc->num_background++;
595 if (fc->num_background == fc->max_background)
597 if (fc->num_background == fc->congestion_threshold &&
598 fc->bdi_initialized) {
599 set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
600 set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
602 list_add_tail(&req->list, &fc->bg_queue);
606 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
609 spin_lock(&fc->lock);
611 fuse_request_send_background_locked(fc, req);
612 spin_unlock(&fc->lock);
614 spin_unlock(&fc->lock);
615 req->out.h.error = -ENOTCONN;
617 fuse_put_request(fc, req);
620 EXPORT_SYMBOL_GPL(fuse_request_send_background);
622 static int fuse_request_send_notify_reply(struct fuse_conn *fc,
623 struct fuse_req *req, u64 unique)
626 struct fuse_iqueue *fiq = &fc->iq;
628 __clear_bit(FR_ISREPLY, &req->flags);
629 req->in.h.unique = unique;
630 spin_lock(&fiq->waitq.lock);
631 if (fiq->connected) {
632 queue_request(fiq, req);
635 spin_unlock(&fiq->waitq.lock);
640 void fuse_force_forget(struct file *file, u64 nodeid)
642 struct inode *inode = file_inode(file);
643 struct fuse_conn *fc = get_fuse_conn(inode);
644 struct fuse_req *req;
645 struct fuse_forget_in inarg;
647 memset(&inarg, 0, sizeof(inarg));
649 req = fuse_get_req_nofail_nopages(fc, file);
650 req->in.h.opcode = FUSE_FORGET;
651 req->in.h.nodeid = nodeid;
653 req->in.args[0].size = sizeof(inarg);
654 req->in.args[0].value = &inarg;
655 __clear_bit(FR_ISREPLY, &req->flags);
656 __fuse_request_send(fc, req);
658 fuse_put_request(fc, req);
662 * Lock the request. Up to the next unlock_request() there mustn't be
663 * anything that could cause a page-fault. If the request was already
666 static int lock_request(struct fuse_req *req)
670 spin_lock(&req->waitq.lock);
671 if (test_bit(FR_ABORTED, &req->flags))
674 set_bit(FR_LOCKED, &req->flags);
675 spin_unlock(&req->waitq.lock);
681 * Unlock request. If it was aborted while locked, caller is responsible
682 * for unlocking and ending the request.
684 static int unlock_request(struct fuse_req *req)
688 spin_lock(&req->waitq.lock);
689 if (test_bit(FR_ABORTED, &req->flags))
692 clear_bit(FR_LOCKED, &req->flags);
693 spin_unlock(&req->waitq.lock);
698 struct fuse_copy_state {
700 struct fuse_req *req;
701 struct iov_iter *iter;
702 struct pipe_buffer *pipebufs;
703 struct pipe_buffer *currbuf;
704 struct pipe_inode_info *pipe;
705 unsigned long nr_segs;
709 unsigned move_pages:1;
712 static void fuse_copy_init(struct fuse_copy_state *cs, int write,
713 struct iov_iter *iter)
715 memset(cs, 0, sizeof(*cs));
720 /* Unmap and put previous page of userspace buffer */
721 static void fuse_copy_finish(struct fuse_copy_state *cs)
724 struct pipe_buffer *buf = cs->currbuf;
727 buf->len = PAGE_SIZE - cs->len;
731 flush_dcache_page(cs->pg);
732 set_page_dirty_lock(cs->pg);
740 * Get another pagefull of userspace buffer, and map it to kernel
741 * address space, and lock request
743 static int fuse_copy_fill(struct fuse_copy_state *cs)
748 err = unlock_request(cs->req);
752 fuse_copy_finish(cs);
754 struct pipe_buffer *buf = cs->pipebufs;
757 err = buf->ops->confirm(cs->pipe, buf);
761 BUG_ON(!cs->nr_segs);
764 cs->offset = buf->offset;
769 if (cs->nr_segs == cs->pipe->buffers)
772 page = alloc_page(GFP_HIGHUSER);
789 err = iov_iter_get_pages(cs->iter, &page, PAGE_SIZE, 1, &off);
797 iov_iter_advance(cs->iter, err);
800 return lock_request(cs->req);
803 /* Do as much copy to/from userspace buffer as we can */
804 static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
806 unsigned ncpy = min(*size, cs->len);
808 void *pgaddr = kmap_atomic(cs->pg);
809 void *buf = pgaddr + cs->offset;
812 memcpy(buf, *val, ncpy);
814 memcpy(*val, buf, ncpy);
816 kunmap_atomic(pgaddr);
825 static int fuse_check_page(struct page *page)
827 if (page_mapcount(page) ||
828 page->mapping != NULL ||
829 page_count(page) != 1 ||
830 (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
837 printk(KERN_WARNING "fuse: trying to steal weird page\n");
838 printk(KERN_WARNING " page=%p index=%li flags=%08lx, count=%i, mapcount=%i, mapping=%p\n", page, page->index, page->flags, page_count(page), page_mapcount(page), page->mapping);
844 static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
847 struct page *oldpage = *pagep;
848 struct page *newpage;
849 struct pipe_buffer *buf = cs->pipebufs;
851 err = unlock_request(cs->req);
855 fuse_copy_finish(cs);
857 err = buf->ops->confirm(cs->pipe, buf);
861 BUG_ON(!cs->nr_segs);
867 if (cs->len != PAGE_SIZE)
870 if (buf->ops->steal(cs->pipe, buf) != 0)
875 if (!PageUptodate(newpage))
876 SetPageUptodate(newpage);
878 ClearPageMappedToDisk(newpage);
880 if (fuse_check_page(newpage) != 0)
881 goto out_fallback_unlock;
884 * This is a new and locked page, it shouldn't be mapped or
885 * have any special flags on it
887 if (WARN_ON(page_mapped(oldpage)))
888 goto out_fallback_unlock;
889 if (WARN_ON(page_has_private(oldpage)))
890 goto out_fallback_unlock;
891 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
892 goto out_fallback_unlock;
893 if (WARN_ON(PageMlocked(oldpage)))
894 goto out_fallback_unlock;
896 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
898 unlock_page(newpage);
902 page_cache_get(newpage);
904 if (!(buf->flags & PIPE_BUF_FLAG_LRU))
905 lru_cache_add_file(newpage);
908 spin_lock(&cs->req->waitq.lock);
909 if (test_bit(FR_ABORTED, &cs->req->flags))
913 spin_unlock(&cs->req->waitq.lock);
916 unlock_page(newpage);
917 page_cache_release(newpage);
921 unlock_page(oldpage);
922 page_cache_release(oldpage);
928 unlock_page(newpage);
931 cs->offset = buf->offset;
933 err = lock_request(cs->req);
940 static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
941 unsigned offset, unsigned count)
943 struct pipe_buffer *buf;
946 if (cs->nr_segs == cs->pipe->buffers)
949 err = unlock_request(cs->req);
953 fuse_copy_finish(cs);
956 page_cache_get(page);
958 buf->offset = offset;
969 * Copy a page in the request to/from the userspace buffer. Must be
972 static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
973 unsigned offset, unsigned count, int zeroing)
976 struct page *page = *pagep;
978 if (page && zeroing && count < PAGE_SIZE)
979 clear_highpage(page);
982 if (cs->write && cs->pipebufs && page) {
983 return fuse_ref_page(cs, page, offset, count);
984 } else if (!cs->len) {
985 if (cs->move_pages && page &&
986 offset == 0 && count == PAGE_SIZE) {
987 err = fuse_try_move_page(cs, pagep);
991 err = fuse_copy_fill(cs);
997 void *mapaddr = kmap_atomic(page);
998 void *buf = mapaddr + offset;
999 offset += fuse_copy_do(cs, &buf, &count);
1000 kunmap_atomic(mapaddr);
1002 offset += fuse_copy_do(cs, NULL, &count);
1004 if (page && !cs->write)
1005 flush_dcache_page(page);
1009 /* Copy pages in the request to/from userspace buffer */
1010 static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
1014 struct fuse_req *req = cs->req;
1016 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
1018 unsigned offset = req->page_descs[i].offset;
1019 unsigned count = min(nbytes, req->page_descs[i].length);
1021 err = fuse_copy_page(cs, &req->pages[i], offset, count,
1031 /* Copy a single argument in the request to/from userspace buffer */
1032 static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
1036 int err = fuse_copy_fill(cs);
1040 fuse_copy_do(cs, &val, &size);
1045 /* Copy request arguments to/from userspace buffer */
1046 static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
1047 unsigned argpages, struct fuse_arg *args,
1053 for (i = 0; !err && i < numargs; i++) {
1054 struct fuse_arg *arg = &args[i];
1055 if (i == numargs - 1 && argpages)
1056 err = fuse_copy_pages(cs, arg->size, zeroing);
1058 err = fuse_copy_one(cs, arg->value, arg->size);
1063 static int forget_pending(struct fuse_iqueue *fiq)
1065 return fiq->forget_list_head.next != NULL;
1068 static int request_pending(struct fuse_iqueue *fiq)
1070 return !list_empty(&fiq->pending) || !list_empty(&fiq->interrupts) ||
1071 forget_pending(fiq);
1075 * Transfer an interrupt request to userspace
1077 * Unlike other requests this is assembled on demand, without a need
1078 * to allocate a separate fuse_req structure.
1080 * Called with fiq->waitq.lock held, releases it
1082 static int fuse_read_interrupt(struct fuse_iqueue *fiq,
1083 struct fuse_copy_state *cs,
1084 size_t nbytes, struct fuse_req *req)
1085 __releases(fiq->waitq.lock)
1087 struct fuse_in_header ih;
1088 struct fuse_interrupt_in arg;
1089 unsigned reqsize = sizeof(ih) + sizeof(arg);
1092 list_del_init(&req->intr_entry);
1093 req->intr_unique = fuse_get_unique(fiq);
1094 memset(&ih, 0, sizeof(ih));
1095 memset(&arg, 0, sizeof(arg));
1097 ih.opcode = FUSE_INTERRUPT;
1098 ih.unique = req->intr_unique;
1099 arg.unique = req->in.h.unique;
1101 spin_unlock(&fiq->waitq.lock);
1102 if (nbytes < reqsize)
1105 err = fuse_copy_one(cs, &ih, sizeof(ih));
1107 err = fuse_copy_one(cs, &arg, sizeof(arg));
1108 fuse_copy_finish(cs);
1110 return err ? err : reqsize;
1113 static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
1117 struct fuse_forget_link *head = fiq->forget_list_head.next;
1118 struct fuse_forget_link **newhead = &head;
1121 for (count = 0; *newhead != NULL && count < max; count++)
1122 newhead = &(*newhead)->next;
1124 fiq->forget_list_head.next = *newhead;
1126 if (fiq->forget_list_head.next == NULL)
1127 fiq->forget_list_tail = &fiq->forget_list_head;
1135 static int fuse_read_single_forget(struct fuse_iqueue *fiq,
1136 struct fuse_copy_state *cs,
1138 __releases(fiq->waitq.lock)
1141 struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
1142 struct fuse_forget_in arg = {
1143 .nlookup = forget->forget_one.nlookup,
1145 struct fuse_in_header ih = {
1146 .opcode = FUSE_FORGET,
1147 .nodeid = forget->forget_one.nodeid,
1148 .unique = fuse_get_unique(fiq),
1149 .len = sizeof(ih) + sizeof(arg),
1152 spin_unlock(&fiq->waitq.lock);
1154 if (nbytes < ih.len)
1157 err = fuse_copy_one(cs, &ih, sizeof(ih));
1159 err = fuse_copy_one(cs, &arg, sizeof(arg));
1160 fuse_copy_finish(cs);
1168 static int fuse_read_batch_forget(struct fuse_iqueue *fiq,
1169 struct fuse_copy_state *cs, size_t nbytes)
1170 __releases(fiq->waitq.lock)
1173 unsigned max_forgets;
1175 struct fuse_forget_link *head;
1176 struct fuse_batch_forget_in arg = { .count = 0 };
1177 struct fuse_in_header ih = {
1178 .opcode = FUSE_BATCH_FORGET,
1179 .unique = fuse_get_unique(fiq),
1180 .len = sizeof(ih) + sizeof(arg),
1183 if (nbytes < ih.len) {
1184 spin_unlock(&fiq->waitq.lock);
1188 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
1189 head = dequeue_forget(fiq, max_forgets, &count);
1190 spin_unlock(&fiq->waitq.lock);
1193 ih.len += count * sizeof(struct fuse_forget_one);
1194 err = fuse_copy_one(cs, &ih, sizeof(ih));
1196 err = fuse_copy_one(cs, &arg, sizeof(arg));
1199 struct fuse_forget_link *forget = head;
1202 err = fuse_copy_one(cs, &forget->forget_one,
1203 sizeof(forget->forget_one));
1205 head = forget->next;
1209 fuse_copy_finish(cs);
1217 static int fuse_read_forget(struct fuse_conn *fc, struct fuse_iqueue *fiq,
1218 struct fuse_copy_state *cs,
1220 __releases(fiq->waitq.lock)
1222 if (fc->minor < 16 || fiq->forget_list_head.next->next == NULL)
1223 return fuse_read_single_forget(fiq, cs, nbytes);
1225 return fuse_read_batch_forget(fiq, cs, nbytes);
1229 * Read a single request into the userspace filesystem's buffer. This
1230 * function waits until a request is available, then removes it from
1231 * the pending list and copies request data to userspace buffer. If
1232 * no reply is needed (FORGET) or request has been aborted or there
1233 * was an error during the copying then it's finished by calling
1234 * request_end(). Otherwise add it to the processing list, and set
1237 static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
1238 struct fuse_copy_state *cs, size_t nbytes)
1241 struct fuse_iqueue *fiq = &fc->iq;
1242 struct fuse_pqueue *fpq = &fc->pq;
1243 struct fuse_req *req;
1248 spin_lock(&fiq->waitq.lock);
1250 if ((file->f_flags & O_NONBLOCK) && fiq->connected &&
1251 !request_pending(fiq))
1254 err = wait_event_interruptible_exclusive_locked(fiq->waitq,
1255 !fiq->connected || request_pending(fiq));
1260 if (!fiq->connected)
1263 if (!list_empty(&fiq->interrupts)) {
1264 req = list_entry(fiq->interrupts.next, struct fuse_req,
1266 return fuse_read_interrupt(fiq, cs, nbytes, req);
1269 if (forget_pending(fiq)) {
1270 if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
1271 return fuse_read_forget(fc, fiq, cs, nbytes);
1273 if (fiq->forget_batch <= -8)
1274 fiq->forget_batch = 16;
1277 req = list_entry(fiq->pending.next, struct fuse_req, list);
1278 clear_bit(FR_PENDING, &req->flags);
1279 list_del_init(&req->list);
1280 spin_unlock(&fiq->waitq.lock);
1282 spin_lock(&fc->lock);
1283 list_add(&req->list, &fpq->io);
1286 reqsize = in->h.len;
1287 /* If request is too large, reply with an error and restart the read */
1288 if (nbytes < reqsize) {
1289 req->out.h.error = -EIO;
1290 /* SETXATTR is special, since it may contain too large data */
1291 if (in->h.opcode == FUSE_SETXATTR)
1292 req->out.h.error = -E2BIG;
1293 list_del_init(&req->list);
1294 request_end(fc, req);
1297 spin_unlock(&fc->lock);
1299 err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1301 err = fuse_copy_args(cs, in->numargs, in->argpages,
1302 (struct fuse_arg *) in->args, 0);
1303 fuse_copy_finish(cs);
1304 spin_lock(&fc->lock);
1305 clear_bit(FR_LOCKED, &req->flags);
1306 if (!fpq->connected) {
1307 list_del_init(&req->list);
1308 request_end(fc, req);
1312 req->out.h.error = -EIO;
1313 list_del_init(&req->list);
1314 request_end(fc, req);
1317 if (!test_bit(FR_ISREPLY, &req->flags)) {
1318 list_del_init(&req->list);
1319 request_end(fc, req);
1321 list_move_tail(&req->list, &fpq->processing);
1322 set_bit(FR_SENT, &req->flags);
1323 /* matches barrier in request_wait_answer() */
1324 smp_mb__after_atomic();
1325 if (test_bit(FR_INTERRUPTED, &req->flags))
1326 queue_interrupt(fiq, req);
1327 spin_unlock(&fc->lock);
1332 spin_unlock(&fiq->waitq.lock);
1336 static int fuse_dev_open(struct inode *inode, struct file *file)
1339 * The fuse device's file's private_data is used to hold
1340 * the fuse_conn(ection) when it is mounted, and is used to
1341 * keep track of whether the file has been mounted already.
1343 file->private_data = NULL;
1347 static ssize_t fuse_dev_read(struct kiocb *iocb, struct iov_iter *to)
1349 struct fuse_copy_state cs;
1350 struct file *file = iocb->ki_filp;
1351 struct fuse_conn *fc = fuse_get_conn(file);
1355 if (!iter_is_iovec(to))
1358 fuse_copy_init(&cs, 1, to);
1360 return fuse_dev_do_read(fc, file, &cs, iov_iter_count(to));
1363 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1364 struct pipe_inode_info *pipe,
1365 size_t len, unsigned int flags)
1370 struct pipe_buffer *bufs;
1371 struct fuse_copy_state cs;
1372 struct fuse_conn *fc = fuse_get_conn(in);
1376 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1380 fuse_copy_init(&cs, 1, NULL);
1383 ret = fuse_dev_do_read(fc, in, &cs, len);
1390 if (!pipe->readers) {
1391 send_sig(SIGPIPE, current, 0);
1397 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1402 while (page_nr < cs.nr_segs) {
1403 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
1404 struct pipe_buffer *buf = pipe->bufs + newbuf;
1406 buf->page = bufs[page_nr].page;
1407 buf->offset = bufs[page_nr].offset;
1408 buf->len = bufs[page_nr].len;
1410 * Need to be careful about this. Having buf->ops in module
1411 * code can Oops if the buffer persists after module unload.
1413 buf->ops = &nosteal_pipe_buf_ops;
1428 if (waitqueue_active(&pipe->wait))
1429 wake_up_interruptible(&pipe->wait);
1430 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
1434 for (; page_nr < cs.nr_segs; page_nr++)
1435 page_cache_release(bufs[page_nr].page);
1441 static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1442 struct fuse_copy_state *cs)
1444 struct fuse_notify_poll_wakeup_out outarg;
1447 if (size != sizeof(outarg))
1450 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1454 fuse_copy_finish(cs);
1455 return fuse_notify_poll_wakeup(fc, &outarg);
1458 fuse_copy_finish(cs);
1462 static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1463 struct fuse_copy_state *cs)
1465 struct fuse_notify_inval_inode_out outarg;
1468 if (size != sizeof(outarg))
1471 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1474 fuse_copy_finish(cs);
1476 down_read(&fc->killsb);
1479 err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1480 outarg.off, outarg.len);
1482 up_read(&fc->killsb);
1486 fuse_copy_finish(cs);
1490 static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1491 struct fuse_copy_state *cs)
1493 struct fuse_notify_inval_entry_out outarg;
1498 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1503 if (size < sizeof(outarg))
1506 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1510 err = -ENAMETOOLONG;
1511 if (outarg.namelen > FUSE_NAME_MAX)
1515 if (size != sizeof(outarg) + outarg.namelen + 1)
1519 name.len = outarg.namelen;
1520 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1523 fuse_copy_finish(cs);
1524 buf[outarg.namelen] = 0;
1525 name.hash = full_name_hash(name.name, name.len);
1527 down_read(&fc->killsb);
1530 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1531 up_read(&fc->killsb);
1537 fuse_copy_finish(cs);
1541 static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1542 struct fuse_copy_state *cs)
1544 struct fuse_notify_delete_out outarg;
1549 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1554 if (size < sizeof(outarg))
1557 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1561 err = -ENAMETOOLONG;
1562 if (outarg.namelen > FUSE_NAME_MAX)
1566 if (size != sizeof(outarg) + outarg.namelen + 1)
1570 name.len = outarg.namelen;
1571 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1574 fuse_copy_finish(cs);
1575 buf[outarg.namelen] = 0;
1576 name.hash = full_name_hash(name.name, name.len);
1578 down_read(&fc->killsb);
1581 err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1582 outarg.child, &name);
1583 up_read(&fc->killsb);
1589 fuse_copy_finish(cs);
1593 static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1594 struct fuse_copy_state *cs)
1596 struct fuse_notify_store_out outarg;
1597 struct inode *inode;
1598 struct address_space *mapping;
1602 unsigned int offset;
1608 if (size < sizeof(outarg))
1611 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1616 if (size - sizeof(outarg) != outarg.size)
1619 nodeid = outarg.nodeid;
1621 down_read(&fc->killsb);
1627 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1631 mapping = inode->i_mapping;
1632 index = outarg.offset >> PAGE_CACHE_SHIFT;
1633 offset = outarg.offset & ~PAGE_CACHE_MASK;
1634 file_size = i_size_read(inode);
1635 end = outarg.offset + outarg.size;
1636 if (end > file_size) {
1638 fuse_write_update_size(inode, file_size);
1644 unsigned int this_num;
1647 page = find_or_create_page(mapping, index,
1648 mapping_gfp_mask(mapping));
1652 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1653 err = fuse_copy_page(cs, &page, offset, this_num, 0);
1654 if (!err && offset == 0 &&
1655 (this_num == PAGE_CACHE_SIZE || file_size == end))
1656 SetPageUptodate(page);
1658 page_cache_release(page);
1673 up_read(&fc->killsb);
1675 fuse_copy_finish(cs);
1679 static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
1681 release_pages(req->pages, req->num_pages, false);
1684 static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1685 struct fuse_notify_retrieve_out *outarg)
1688 struct address_space *mapping = inode->i_mapping;
1689 struct fuse_req *req;
1693 unsigned int offset;
1694 size_t total_len = 0;
1697 offset = outarg->offset & ~PAGE_CACHE_MASK;
1698 file_size = i_size_read(inode);
1701 if (outarg->offset > file_size)
1703 else if (outarg->offset + num > file_size)
1704 num = file_size - outarg->offset;
1706 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1707 num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
1709 req = fuse_get_req(fc, num_pages);
1711 return PTR_ERR(req);
1713 req->in.h.opcode = FUSE_NOTIFY_REPLY;
1714 req->in.h.nodeid = outarg->nodeid;
1715 req->in.numargs = 2;
1716 req->in.argpages = 1;
1717 req->page_descs[0].offset = offset;
1718 req->end = fuse_retrieve_end;
1720 index = outarg->offset >> PAGE_CACHE_SHIFT;
1722 while (num && req->num_pages < num_pages) {
1724 unsigned int this_num;
1726 page = find_get_page(mapping, index);
1730 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1731 req->pages[req->num_pages] = page;
1732 req->page_descs[req->num_pages].length = this_num;
1737 total_len += this_num;
1740 req->misc.retrieve_in.offset = outarg->offset;
1741 req->misc.retrieve_in.size = total_len;
1742 req->in.args[0].size = sizeof(req->misc.retrieve_in);
1743 req->in.args[0].value = &req->misc.retrieve_in;
1744 req->in.args[1].size = total_len;
1746 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1748 fuse_retrieve_end(fc, req);
1753 static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1754 struct fuse_copy_state *cs)
1756 struct fuse_notify_retrieve_out outarg;
1757 struct inode *inode;
1761 if (size != sizeof(outarg))
1764 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1768 fuse_copy_finish(cs);
1770 down_read(&fc->killsb);
1773 u64 nodeid = outarg.nodeid;
1775 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1777 err = fuse_retrieve(fc, inode, &outarg);
1781 up_read(&fc->killsb);
1786 fuse_copy_finish(cs);
1790 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1791 unsigned int size, struct fuse_copy_state *cs)
1793 /* Don't try to move pages (yet) */
1797 case FUSE_NOTIFY_POLL:
1798 return fuse_notify_poll(fc, size, cs);
1800 case FUSE_NOTIFY_INVAL_INODE:
1801 return fuse_notify_inval_inode(fc, size, cs);
1803 case FUSE_NOTIFY_INVAL_ENTRY:
1804 return fuse_notify_inval_entry(fc, size, cs);
1806 case FUSE_NOTIFY_STORE:
1807 return fuse_notify_store(fc, size, cs);
1809 case FUSE_NOTIFY_RETRIEVE:
1810 return fuse_notify_retrieve(fc, size, cs);
1812 case FUSE_NOTIFY_DELETE:
1813 return fuse_notify_delete(fc, size, cs);
1816 fuse_copy_finish(cs);
1821 /* Look up request on processing list by unique ID */
1822 static struct fuse_req *request_find(struct fuse_pqueue *fpq, u64 unique)
1824 struct fuse_req *req;
1826 list_for_each_entry(req, &fpq->processing, list) {
1827 if (req->in.h.unique == unique || req->intr_unique == unique)
1833 static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1836 unsigned reqsize = sizeof(struct fuse_out_header);
1839 return nbytes != reqsize ? -EINVAL : 0;
1841 reqsize += len_args(out->numargs, out->args);
1843 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1845 else if (reqsize > nbytes) {
1846 struct fuse_arg *lastarg = &out->args[out->numargs-1];
1847 unsigned diffsize = reqsize - nbytes;
1848 if (diffsize > lastarg->size)
1850 lastarg->size -= diffsize;
1852 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1857 * Write a single reply to a request. First the header is copied from
1858 * the write buffer. The request is then searched on the processing
1859 * list by the unique ID found in the header. If found, then remove
1860 * it from the list and copy the rest of the buffer to the request.
1861 * The request is finished by calling request_end()
1863 static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
1864 struct fuse_copy_state *cs, size_t nbytes)
1867 struct fuse_pqueue *fpq = &fc->pq;
1868 struct fuse_req *req;
1869 struct fuse_out_header oh;
1871 if (nbytes < sizeof(struct fuse_out_header))
1874 err = fuse_copy_one(cs, &oh, sizeof(oh));
1879 if (oh.len != nbytes)
1883 * Zero oh.unique indicates unsolicited notification message
1884 * and error contains notification code.
1887 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
1888 return err ? err : nbytes;
1892 if (oh.error <= -1000 || oh.error > 0)
1895 spin_lock(&fc->lock);
1897 if (!fpq->connected)
1900 req = request_find(fpq, oh.unique);
1904 /* Is it an interrupt reply? */
1905 if (req->intr_unique == oh.unique) {
1907 if (nbytes != sizeof(struct fuse_out_header))
1910 if (oh.error == -ENOSYS)
1911 fc->no_interrupt = 1;
1912 else if (oh.error == -EAGAIN)
1913 queue_interrupt(&fc->iq, req);
1915 spin_unlock(&fc->lock);
1916 fuse_copy_finish(cs);
1920 clear_bit(FR_SENT, &req->flags);
1921 list_move(&req->list, &fpq->io);
1923 set_bit(FR_LOCKED, &req->flags);
1925 if (!req->out.page_replace)
1927 spin_unlock(&fc->lock);
1929 err = copy_out_args(cs, &req->out, nbytes);
1930 fuse_copy_finish(cs);
1932 spin_lock(&fc->lock);
1933 clear_bit(FR_LOCKED, &req->flags);
1934 if (!fpq->connected)
1937 req->out.h.error = -EIO;
1938 list_del_init(&req->list);
1939 request_end(fc, req);
1941 return err ? err : nbytes;
1944 spin_unlock(&fc->lock);
1946 fuse_copy_finish(cs);
1950 static ssize_t fuse_dev_write(struct kiocb *iocb, struct iov_iter *from)
1952 struct fuse_copy_state cs;
1953 struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
1957 if (!iter_is_iovec(from))
1960 fuse_copy_init(&cs, 0, from);
1962 return fuse_dev_do_write(fc, &cs, iov_iter_count(from));
1965 static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1966 struct file *out, loff_t *ppos,
1967 size_t len, unsigned int flags)
1971 struct pipe_buffer *bufs;
1972 struct fuse_copy_state cs;
1973 struct fuse_conn *fc;
1977 fc = fuse_get_conn(out);
1981 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1988 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
1989 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
1999 struct pipe_buffer *ibuf;
2000 struct pipe_buffer *obuf;
2002 BUG_ON(nbuf >= pipe->buffers);
2003 BUG_ON(!pipe->nrbufs);
2004 ibuf = &pipe->bufs[pipe->curbuf];
2007 if (rem >= ibuf->len) {
2010 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
2013 ibuf->ops->get(pipe, ibuf);
2015 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
2017 ibuf->offset += obuf->len;
2018 ibuf->len -= obuf->len;
2025 fuse_copy_init(&cs, 0, NULL);
2030 if (flags & SPLICE_F_MOVE)
2033 ret = fuse_dev_do_write(fc, &cs, len);
2035 for (idx = 0; idx < nbuf; idx++) {
2036 struct pipe_buffer *buf = &bufs[idx];
2037 buf->ops->release(pipe, buf);
2044 static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
2046 unsigned mask = POLLOUT | POLLWRNORM;
2047 struct fuse_iqueue *fiq;
2048 struct fuse_conn *fc = fuse_get_conn(file);
2053 poll_wait(file, &fiq->waitq, wait);
2055 spin_lock(&fiq->waitq.lock);
2056 if (!fiq->connected)
2058 else if (request_pending(fiq))
2059 mask |= POLLIN | POLLRDNORM;
2060 spin_unlock(&fiq->waitq.lock);
2066 * Abort all requests on the given list (pending or processing)
2068 * This function releases and reacquires fc->lock
2070 static void end_requests(struct fuse_conn *fc, struct list_head *head)
2071 __releases(fc->lock)
2072 __acquires(fc->lock)
2074 while (!list_empty(head)) {
2075 struct fuse_req *req;
2076 req = list_entry(head->next, struct fuse_req, list);
2077 req->out.h.error = -ECONNABORTED;
2078 clear_bit(FR_PENDING, &req->flags);
2079 clear_bit(FR_SENT, &req->flags);
2080 list_del_init(&req->list);
2081 request_end(fc, req);
2082 spin_lock(&fc->lock);
2086 static void end_polls(struct fuse_conn *fc)
2090 p = rb_first(&fc->polled_files);
2093 struct fuse_file *ff;
2094 ff = rb_entry(p, struct fuse_file, polled_node);
2095 wake_up_interruptible_all(&ff->poll_wait);
2102 * Abort all requests.
2104 * Emergency exit in case of a malicious or accidental deadlock, or just a hung
2107 * The same effect is usually achievable through killing the filesystem daemon
2108 * and all users of the filesystem. The exception is the combination of an
2109 * asynchronous request and the tricky deadlock (see
2110 * Documentation/filesystems/fuse.txt).
2112 * Aborting requests under I/O goes as follows: 1: Separate out unlocked
2113 * requests, they should be finished off immediately. Locked requests will be
2114 * finished after unlock; see unlock_request(). 2: Finish off the unlocked
2115 * requests. It is possible that some request will finish before we can. This
2116 * is OK, the request will in that case be removed from the list before we touch
2119 void fuse_abort_conn(struct fuse_conn *fc)
2121 struct fuse_iqueue *fiq = &fc->iq;
2122 struct fuse_pqueue *fpq = &fc->pq;
2124 spin_lock(&fc->lock);
2125 if (fc->connected) {
2126 struct fuse_req *req, *next;
2132 fuse_set_initialized(fc);
2134 list_for_each_entry_safe(req, next, &fpq->io, list) {
2135 req->out.h.error = -ECONNABORTED;
2136 spin_lock(&req->waitq.lock);
2137 set_bit(FR_ABORTED, &req->flags);
2138 if (!test_bit(FR_LOCKED, &req->flags))
2139 list_move(&req->list, &to_end1);
2140 spin_unlock(&req->waitq.lock);
2142 fc->max_background = UINT_MAX;
2145 spin_lock(&fiq->waitq.lock);
2147 list_splice_init(&fiq->pending, &to_end2);
2148 while (forget_pending(fiq))
2149 kfree(dequeue_forget(fiq, 1, NULL));
2150 wake_up_all_locked(&fiq->waitq);
2151 spin_unlock(&fiq->waitq.lock);
2152 kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
2154 list_splice_init(&fpq->processing, &to_end2);
2155 while (!list_empty(&to_end1)) {
2156 req = list_first_entry(&to_end1, struct fuse_req, list);
2157 __fuse_get_request(req);
2158 list_del_init(&req->list);
2159 request_end(fc, req);
2160 spin_lock(&fc->lock);
2162 end_requests(fc, &to_end2);
2164 wake_up_all(&fc->blocked_waitq);
2166 spin_unlock(&fc->lock);
2168 EXPORT_SYMBOL_GPL(fuse_abort_conn);
2170 int fuse_dev_release(struct inode *inode, struct file *file)
2172 struct fuse_conn *fc = fuse_get_conn(file);
2174 WARN_ON(!list_empty(&fc->pq.io));
2175 WARN_ON(fc->iq.fasync != NULL);
2176 fuse_abort_conn(fc);
2182 EXPORT_SYMBOL_GPL(fuse_dev_release);
2184 static int fuse_dev_fasync(int fd, struct file *file, int on)
2186 struct fuse_conn *fc = fuse_get_conn(file);
2190 /* No locking - fasync_helper does its own locking */
2191 return fasync_helper(fd, file, on, &fc->iq.fasync);
2194 const struct file_operations fuse_dev_operations = {
2195 .owner = THIS_MODULE,
2196 .open = fuse_dev_open,
2197 .llseek = no_llseek,
2198 .read_iter = fuse_dev_read,
2199 .splice_read = fuse_dev_splice_read,
2200 .write_iter = fuse_dev_write,
2201 .splice_write = fuse_dev_splice_write,
2202 .poll = fuse_dev_poll,
2203 .release = fuse_dev_release,
2204 .fasync = fuse_dev_fasync,
2206 EXPORT_SYMBOL_GPL(fuse_dev_operations);
2208 static struct miscdevice fuse_miscdevice = {
2209 .minor = FUSE_MINOR,
2211 .fops = &fuse_dev_operations,
2214 int __init fuse_dev_init(void)
2217 fuse_req_cachep = kmem_cache_create("fuse_request",
2218 sizeof(struct fuse_req),
2220 if (!fuse_req_cachep)
2223 err = misc_register(&fuse_miscdevice);
2225 goto out_cache_clean;
2230 kmem_cache_destroy(fuse_req_cachep);
2235 void fuse_dev_cleanup(void)
2237 misc_deregister(&fuse_miscdevice);
2238 kmem_cache_destroy(fuse_req_cachep);