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;
53 static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
55 struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags);
58 struct fuse_page_desc *page_descs;
60 if (npages <= FUSE_REQ_INLINE_PAGES) {
61 pages = req->inline_pages;
62 page_descs = req->inline_page_descs;
64 pages = kmalloc(sizeof(struct page *) * npages, flags);
65 page_descs = kmalloc(sizeof(struct fuse_page_desc) *
69 if (!pages || !page_descs) {
72 kmem_cache_free(fuse_req_cachep, req);
76 fuse_request_init(req, pages, page_descs, npages);
81 struct fuse_req *fuse_request_alloc(unsigned npages)
83 return __fuse_request_alloc(npages, GFP_KERNEL);
85 EXPORT_SYMBOL_GPL(fuse_request_alloc);
87 struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
89 return __fuse_request_alloc(npages, GFP_NOFS);
92 void fuse_request_free(struct fuse_req *req)
94 if (req->pages != req->inline_pages) {
96 kfree(req->page_descs);
98 kmem_cache_free(fuse_req_cachep, req);
101 static void block_sigs(sigset_t *oldset)
105 siginitsetinv(&mask, sigmask(SIGKILL));
106 sigprocmask(SIG_BLOCK, &mask, oldset);
109 static void restore_sigs(sigset_t *oldset)
111 sigprocmask(SIG_SETMASK, oldset, NULL);
114 static void __fuse_get_request(struct fuse_req *req)
116 atomic_inc(&req->count);
119 /* Must be called with > 1 refcount */
120 static void __fuse_put_request(struct fuse_req *req)
122 BUG_ON(atomic_read(&req->count) < 2);
123 atomic_dec(&req->count);
126 static void fuse_req_init_context(struct fuse_req *req)
128 req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid());
129 req->in.h.gid = from_kgid_munged(&init_user_ns, current_fsgid());
130 req->in.h.pid = current->pid;
133 static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
135 return !fc->initialized || (for_background && fc->blocked);
138 static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
141 struct fuse_req *req;
143 atomic_inc(&fc->num_waiting);
145 if (fuse_block_alloc(fc, for_background)) {
150 intr = wait_event_interruptible_exclusive(fc->blocked_waitq,
151 !fuse_block_alloc(fc, for_background));
152 restore_sigs(&oldset);
162 req = fuse_request_alloc(npages);
166 wake_up(&fc->blocked_waitq);
170 fuse_req_init_context(req);
172 req->background = for_background;
176 atomic_dec(&fc->num_waiting);
180 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
182 return __fuse_get_req(fc, npages, false);
184 EXPORT_SYMBOL_GPL(fuse_get_req);
186 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
189 return __fuse_get_req(fc, npages, true);
191 EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
194 * Return request in fuse_file->reserved_req. However that may
195 * currently be in use. If that is the case, wait for it to become
198 static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
201 struct fuse_req *req = NULL;
202 struct fuse_file *ff = file->private_data;
205 wait_event(fc->reserved_req_waitq, ff->reserved_req);
206 spin_lock(&fc->lock);
207 if (ff->reserved_req) {
208 req = ff->reserved_req;
209 ff->reserved_req = NULL;
210 req->stolen_file = get_file(file);
212 spin_unlock(&fc->lock);
219 * Put stolen request back into fuse_file->reserved_req
221 static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
223 struct file *file = req->stolen_file;
224 struct fuse_file *ff = file->private_data;
226 spin_lock(&fc->lock);
227 fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
228 BUG_ON(ff->reserved_req);
229 ff->reserved_req = req;
230 wake_up_all(&fc->reserved_req_waitq);
231 spin_unlock(&fc->lock);
236 * Gets a requests for a file operation, always succeeds
238 * This is used for sending the FLUSH request, which must get to
239 * userspace, due to POSIX locks which may need to be unlocked.
241 * If allocation fails due to OOM, use the reserved request in
244 * This is very unlikely to deadlock accidentally, since the
245 * filesystem should not have it's own file open. If deadlock is
246 * intentional, it can still be broken by "aborting" the filesystem.
248 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
251 struct fuse_req *req;
253 atomic_inc(&fc->num_waiting);
254 wait_event(fc->blocked_waitq, fc->initialized);
255 req = fuse_request_alloc(0);
257 req = get_reserved_req(fc, file);
259 fuse_req_init_context(req);
265 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
267 if (atomic_dec_and_test(&req->count)) {
268 if (unlikely(req->background)) {
270 * We get here in the unlikely case that a background
271 * request was allocated but not sent
273 spin_lock(&fc->lock);
275 wake_up(&fc->blocked_waitq);
276 spin_unlock(&fc->lock);
280 atomic_dec(&fc->num_waiting);
282 if (req->stolen_file)
283 put_reserved_req(fc, req);
285 fuse_request_free(req);
288 EXPORT_SYMBOL_GPL(fuse_put_request);
290 static unsigned len_args(unsigned numargs, struct fuse_arg *args)
295 for (i = 0; i < numargs; i++)
296 nbytes += args[i].size;
301 static u64 fuse_get_unique(struct fuse_conn *fc)
304 /* zero is special */
311 static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
313 req->in.h.len = sizeof(struct fuse_in_header) +
314 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
315 list_add_tail(&req->list, &fc->pending);
316 req->state = FUSE_REQ_PENDING;
319 atomic_inc(&fc->num_waiting);
322 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
325 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
326 u64 nodeid, u64 nlookup)
328 forget->forget_one.nodeid = nodeid;
329 forget->forget_one.nlookup = nlookup;
331 spin_lock(&fc->lock);
333 fc->forget_list_tail->next = forget;
334 fc->forget_list_tail = forget;
336 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
340 spin_unlock(&fc->lock);
343 static void flush_bg_queue(struct fuse_conn *fc)
345 while (fc->active_background < fc->max_background &&
346 !list_empty(&fc->bg_queue)) {
347 struct fuse_req *req;
349 req = list_entry(fc->bg_queue.next, struct fuse_req, list);
350 list_del(&req->list);
351 fc->active_background++;
352 req->in.h.unique = fuse_get_unique(fc);
353 queue_request(fc, req);
358 * This function is called when a request is finished. Either a reply
359 * has arrived or it was aborted (and not yet sent) or some error
360 * occurred during communication with userspace, or the device file
361 * was closed. The requester thread is woken up (if still waiting),
362 * the 'end' callback is called if given, else the reference to the
363 * request is released
365 * Called with fc->lock, unlocks it
367 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
370 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
372 list_del(&req->list);
373 list_del(&req->intr_entry);
374 req->state = FUSE_REQ_FINISHED;
375 if (req->background) {
378 if (fc->num_background == fc->max_background)
381 /* Wake up next waiter, if any */
382 if (!fc->blocked && waitqueue_active(&fc->blocked_waitq))
383 wake_up(&fc->blocked_waitq);
385 if (fc->num_background == fc->congestion_threshold &&
386 fc->connected && fc->bdi_initialized) {
387 clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
388 clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
390 fc->num_background--;
391 fc->active_background--;
394 spin_unlock(&fc->lock);
395 wake_up(&req->waitq);
398 fuse_put_request(fc, req);
401 static void wait_answer_interruptible(struct fuse_conn *fc,
402 struct fuse_req *req)
406 if (signal_pending(current))
409 spin_unlock(&fc->lock);
410 wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
411 spin_lock(&fc->lock);
414 static void queue_interrupt(struct fuse_conn *fc, struct fuse_req *req)
416 list_add_tail(&req->intr_entry, &fc->interrupts);
418 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
421 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
425 if (!fc->no_interrupt) {
426 /* Any signal may interrupt this */
427 wait_answer_interruptible(fc, req);
431 if (req->state == FUSE_REQ_FINISHED)
434 req->interrupted = 1;
435 if (req->state == FUSE_REQ_SENT)
436 queue_interrupt(fc, req);
442 /* Only fatal signals may interrupt this */
444 wait_answer_interruptible(fc, req);
445 restore_sigs(&oldset);
449 if (req->state == FUSE_REQ_FINISHED)
452 /* Request is not yet in userspace, bail out */
453 if (req->state == FUSE_REQ_PENDING) {
454 list_del(&req->list);
455 __fuse_put_request(req);
456 req->out.h.error = -EINTR;
462 * Either request is already in userspace, or it was forced.
465 spin_unlock(&fc->lock);
466 wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
467 spin_lock(&fc->lock);
473 BUG_ON(req->state != FUSE_REQ_FINISHED);
475 /* This is uninterruptible sleep, because data is
476 being copied to/from the buffers of req. During
477 locked state, there mustn't be any filesystem
478 operation (e.g. page fault), since that could lead
480 spin_unlock(&fc->lock);
481 wait_event(req->waitq, !req->locked);
482 spin_lock(&fc->lock);
486 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
488 BUG_ON(req->background);
489 spin_lock(&fc->lock);
491 req->out.h.error = -ENOTCONN;
492 else if (fc->conn_error)
493 req->out.h.error = -ECONNREFUSED;
495 req->in.h.unique = fuse_get_unique(fc);
496 queue_request(fc, req);
497 /* acquire extra reference, since request is still needed
498 after request_end() */
499 __fuse_get_request(req);
501 request_wait_answer(fc, req);
503 spin_unlock(&fc->lock);
506 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
509 __fuse_request_send(fc, req);
511 EXPORT_SYMBOL_GPL(fuse_request_send);
513 static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
514 struct fuse_req *req)
516 BUG_ON(!req->background);
517 fc->num_background++;
518 if (fc->num_background == fc->max_background)
520 if (fc->num_background == fc->congestion_threshold &&
521 fc->bdi_initialized) {
522 set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
523 set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
525 list_add_tail(&req->list, &fc->bg_queue);
529 static void fuse_request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
531 spin_lock(&fc->lock);
533 fuse_request_send_nowait_locked(fc, req);
534 spin_unlock(&fc->lock);
536 req->out.h.error = -ENOTCONN;
537 request_end(fc, req);
541 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
544 fuse_request_send_nowait(fc, req);
546 EXPORT_SYMBOL_GPL(fuse_request_send_background);
548 static int fuse_request_send_notify_reply(struct fuse_conn *fc,
549 struct fuse_req *req, u64 unique)
554 req->in.h.unique = unique;
555 spin_lock(&fc->lock);
557 queue_request(fc, req);
560 spin_unlock(&fc->lock);
566 * Called under fc->lock
568 * fc->connected must have been checked previously
570 void fuse_request_send_background_locked(struct fuse_conn *fc,
571 struct fuse_req *req)
574 fuse_request_send_nowait_locked(fc, req);
577 void fuse_force_forget(struct file *file, u64 nodeid)
579 struct inode *inode = file_inode(file);
580 struct fuse_conn *fc = get_fuse_conn(inode);
581 struct fuse_req *req;
582 struct fuse_forget_in inarg;
584 memset(&inarg, 0, sizeof(inarg));
586 req = fuse_get_req_nofail_nopages(fc, file);
587 req->in.h.opcode = FUSE_FORGET;
588 req->in.h.nodeid = nodeid;
590 req->in.args[0].size = sizeof(inarg);
591 req->in.args[0].value = &inarg;
593 __fuse_request_send(fc, req);
595 fuse_put_request(fc, req);
599 * Lock the request. Up to the next unlock_request() there mustn't be
600 * anything that could cause a page-fault. If the request was already
603 static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
607 spin_lock(&fc->lock);
612 spin_unlock(&fc->lock);
618 * Unlock request. If it was aborted during being locked, the
619 * requester thread is currently waiting for it to be unlocked, so
622 static void unlock_request(struct fuse_conn *fc, struct fuse_req *req)
625 spin_lock(&fc->lock);
628 wake_up(&req->waitq);
629 spin_unlock(&fc->lock);
633 struct fuse_copy_state {
634 struct fuse_conn *fc;
636 struct fuse_req *req;
637 const struct iovec *iov;
638 struct pipe_buffer *pipebufs;
639 struct pipe_buffer *currbuf;
640 struct pipe_inode_info *pipe;
641 unsigned long nr_segs;
642 unsigned long seglen;
648 unsigned move_pages:1;
651 static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
653 const struct iovec *iov, unsigned long nr_segs)
655 memset(cs, 0, sizeof(*cs));
659 cs->nr_segs = nr_segs;
662 /* Unmap and put previous page of userspace buffer */
663 static void fuse_copy_finish(struct fuse_copy_state *cs)
666 struct pipe_buffer *buf = cs->currbuf;
669 buf->ops->unmap(cs->pipe, buf, cs->mapaddr);
672 buf->len = PAGE_SIZE - cs->len;
676 } else if (cs->mapaddr) {
679 flush_dcache_page(cs->pg);
680 set_page_dirty_lock(cs->pg);
688 * Get another pagefull of userspace buffer, and map it to kernel
689 * address space, and lock request
691 static int fuse_copy_fill(struct fuse_copy_state *cs)
693 unsigned long offset;
696 unlock_request(cs->fc, cs->req);
697 fuse_copy_finish(cs);
699 struct pipe_buffer *buf = cs->pipebufs;
702 err = buf->ops->confirm(cs->pipe, buf);
706 BUG_ON(!cs->nr_segs);
708 cs->mapaddr = buf->ops->map(cs->pipe, buf, 0);
710 cs->buf = cs->mapaddr + buf->offset;
716 if (cs->nr_segs == cs->pipe->buffers)
719 page = alloc_page(GFP_HIGHUSER);
728 cs->mapaddr = kmap(page);
729 cs->buf = cs->mapaddr;
736 BUG_ON(!cs->nr_segs);
737 cs->seglen = cs->iov[0].iov_len;
738 cs->addr = (unsigned long) cs->iov[0].iov_base;
742 err = get_user_pages_fast(cs->addr, 1, cs->write, &cs->pg);
746 offset = cs->addr % PAGE_SIZE;
747 cs->mapaddr = kmap(cs->pg);
748 cs->buf = cs->mapaddr + offset;
749 cs->len = min(PAGE_SIZE - offset, cs->seglen);
750 cs->seglen -= cs->len;
754 return lock_request(cs->fc, cs->req);
757 /* Do as much copy to/from userspace buffer as we can */
758 static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
760 unsigned ncpy = min(*size, cs->len);
763 memcpy(cs->buf, *val, ncpy);
765 memcpy(*val, cs->buf, ncpy);
774 static int fuse_check_page(struct page *page)
776 if (page_mapcount(page) ||
777 page->mapping != NULL ||
778 page_count(page) != 1 ||
779 (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
786 printk(KERN_WARNING "fuse: trying to steal weird page\n");
787 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);
793 static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
796 struct page *oldpage = *pagep;
797 struct page *newpage;
798 struct pipe_buffer *buf = cs->pipebufs;
800 unlock_request(cs->fc, cs->req);
801 fuse_copy_finish(cs);
803 err = buf->ops->confirm(cs->pipe, buf);
807 BUG_ON(!cs->nr_segs);
813 if (cs->len != PAGE_SIZE)
816 if (buf->ops->steal(cs->pipe, buf) != 0)
821 if (WARN_ON(!PageUptodate(newpage)))
824 ClearPageMappedToDisk(newpage);
826 if (fuse_check_page(newpage) != 0)
827 goto out_fallback_unlock;
830 * This is a new and locked page, it shouldn't be mapped or
831 * have any special flags on it
833 if (WARN_ON(page_mapped(oldpage)))
834 goto out_fallback_unlock;
835 if (WARN_ON(page_has_private(oldpage)))
836 goto out_fallback_unlock;
837 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
838 goto out_fallback_unlock;
839 if (WARN_ON(PageMlocked(oldpage)))
840 goto out_fallback_unlock;
842 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
844 unlock_page(newpage);
848 page_cache_get(newpage);
850 if (!(buf->flags & PIPE_BUF_FLAG_LRU))
851 lru_cache_add_file(newpage);
854 spin_lock(&cs->fc->lock);
855 if (cs->req->aborted)
859 spin_unlock(&cs->fc->lock);
862 unlock_page(newpage);
863 page_cache_release(newpage);
867 unlock_page(oldpage);
868 page_cache_release(oldpage);
874 unlock_page(newpage);
876 cs->mapaddr = buf->ops->map(cs->pipe, buf, 1);
877 cs->buf = cs->mapaddr + buf->offset;
879 err = lock_request(cs->fc, cs->req);
886 static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
887 unsigned offset, unsigned count)
889 struct pipe_buffer *buf;
891 if (cs->nr_segs == cs->pipe->buffers)
894 unlock_request(cs->fc, cs->req);
895 fuse_copy_finish(cs);
898 page_cache_get(page);
900 buf->offset = offset;
911 * Copy a page in the request to/from the userspace buffer. Must be
914 static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
915 unsigned offset, unsigned count, int zeroing)
918 struct page *page = *pagep;
920 if (page && zeroing && count < PAGE_SIZE)
921 clear_highpage(page);
924 if (cs->write && cs->pipebufs && page) {
925 return fuse_ref_page(cs, page, offset, count);
926 } else if (!cs->len) {
927 if (cs->move_pages && page &&
928 offset == 0 && count == PAGE_SIZE) {
929 err = fuse_try_move_page(cs, pagep);
933 err = fuse_copy_fill(cs);
939 void *mapaddr = kmap_atomic(page);
940 void *buf = mapaddr + offset;
941 offset += fuse_copy_do(cs, &buf, &count);
942 kunmap_atomic(mapaddr);
944 offset += fuse_copy_do(cs, NULL, &count);
946 if (page && !cs->write)
947 flush_dcache_page(page);
951 /* Copy pages in the request to/from userspace buffer */
952 static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
956 struct fuse_req *req = cs->req;
958 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
960 unsigned offset = req->page_descs[i].offset;
961 unsigned count = min(nbytes, req->page_descs[i].length);
963 err = fuse_copy_page(cs, &req->pages[i], offset, count,
973 /* Copy a single argument in the request to/from userspace buffer */
974 static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
978 int err = fuse_copy_fill(cs);
982 fuse_copy_do(cs, &val, &size);
987 /* Copy request arguments to/from userspace buffer */
988 static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
989 unsigned argpages, struct fuse_arg *args,
995 for (i = 0; !err && i < numargs; i++) {
996 struct fuse_arg *arg = &args[i];
997 if (i == numargs - 1 && argpages)
998 err = fuse_copy_pages(cs, arg->size, zeroing);
1000 err = fuse_copy_one(cs, arg->value, arg->size);
1005 static int forget_pending(struct fuse_conn *fc)
1007 return fc->forget_list_head.next != NULL;
1010 static int request_pending(struct fuse_conn *fc)
1012 return !list_empty(&fc->pending) || !list_empty(&fc->interrupts) ||
1016 /* Wait until a request is available on the pending list */
1017 static void request_wait(struct fuse_conn *fc)
1018 __releases(fc->lock)
1019 __acquires(fc->lock)
1021 DECLARE_WAITQUEUE(wait, current);
1023 add_wait_queue_exclusive(&fc->waitq, &wait);
1024 while (fc->connected && !request_pending(fc)) {
1025 set_current_state(TASK_INTERRUPTIBLE);
1026 if (signal_pending(current))
1029 spin_unlock(&fc->lock);
1031 spin_lock(&fc->lock);
1033 set_current_state(TASK_RUNNING);
1034 remove_wait_queue(&fc->waitq, &wait);
1038 * Transfer an interrupt request to userspace
1040 * Unlike other requests this is assembled on demand, without a need
1041 * to allocate a separate fuse_req structure.
1043 * Called with fc->lock held, releases it
1045 static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_copy_state *cs,
1046 size_t nbytes, struct fuse_req *req)
1047 __releases(fc->lock)
1049 struct fuse_in_header ih;
1050 struct fuse_interrupt_in arg;
1051 unsigned reqsize = sizeof(ih) + sizeof(arg);
1054 list_del_init(&req->intr_entry);
1055 req->intr_unique = fuse_get_unique(fc);
1056 memset(&ih, 0, sizeof(ih));
1057 memset(&arg, 0, sizeof(arg));
1059 ih.opcode = FUSE_INTERRUPT;
1060 ih.unique = req->intr_unique;
1061 arg.unique = req->in.h.unique;
1063 spin_unlock(&fc->lock);
1064 if (nbytes < reqsize)
1067 err = fuse_copy_one(cs, &ih, sizeof(ih));
1069 err = fuse_copy_one(cs, &arg, sizeof(arg));
1070 fuse_copy_finish(cs);
1072 return err ? err : reqsize;
1075 static struct fuse_forget_link *dequeue_forget(struct fuse_conn *fc,
1079 struct fuse_forget_link *head = fc->forget_list_head.next;
1080 struct fuse_forget_link **newhead = &head;
1083 for (count = 0; *newhead != NULL && count < max; count++)
1084 newhead = &(*newhead)->next;
1086 fc->forget_list_head.next = *newhead;
1088 if (fc->forget_list_head.next == NULL)
1089 fc->forget_list_tail = &fc->forget_list_head;
1097 static int fuse_read_single_forget(struct fuse_conn *fc,
1098 struct fuse_copy_state *cs,
1100 __releases(fc->lock)
1103 struct fuse_forget_link *forget = dequeue_forget(fc, 1, NULL);
1104 struct fuse_forget_in arg = {
1105 .nlookup = forget->forget_one.nlookup,
1107 struct fuse_in_header ih = {
1108 .opcode = FUSE_FORGET,
1109 .nodeid = forget->forget_one.nodeid,
1110 .unique = fuse_get_unique(fc),
1111 .len = sizeof(ih) + sizeof(arg),
1114 spin_unlock(&fc->lock);
1116 if (nbytes < ih.len)
1119 err = fuse_copy_one(cs, &ih, sizeof(ih));
1121 err = fuse_copy_one(cs, &arg, sizeof(arg));
1122 fuse_copy_finish(cs);
1130 static int fuse_read_batch_forget(struct fuse_conn *fc,
1131 struct fuse_copy_state *cs, size_t nbytes)
1132 __releases(fc->lock)
1135 unsigned max_forgets;
1137 struct fuse_forget_link *head;
1138 struct fuse_batch_forget_in arg = { .count = 0 };
1139 struct fuse_in_header ih = {
1140 .opcode = FUSE_BATCH_FORGET,
1141 .unique = fuse_get_unique(fc),
1142 .len = sizeof(ih) + sizeof(arg),
1145 if (nbytes < ih.len) {
1146 spin_unlock(&fc->lock);
1150 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
1151 head = dequeue_forget(fc, max_forgets, &count);
1152 spin_unlock(&fc->lock);
1155 ih.len += count * sizeof(struct fuse_forget_one);
1156 err = fuse_copy_one(cs, &ih, sizeof(ih));
1158 err = fuse_copy_one(cs, &arg, sizeof(arg));
1161 struct fuse_forget_link *forget = head;
1164 err = fuse_copy_one(cs, &forget->forget_one,
1165 sizeof(forget->forget_one));
1167 head = forget->next;
1171 fuse_copy_finish(cs);
1179 static int fuse_read_forget(struct fuse_conn *fc, struct fuse_copy_state *cs,
1181 __releases(fc->lock)
1183 if (fc->minor < 16 || fc->forget_list_head.next->next == NULL)
1184 return fuse_read_single_forget(fc, cs, nbytes);
1186 return fuse_read_batch_forget(fc, cs, nbytes);
1190 * Read a single request into the userspace filesystem's buffer. This
1191 * function waits until a request is available, then removes it from
1192 * the pending list and copies request data to userspace buffer. If
1193 * no reply is needed (FORGET) or request has been aborted or there
1194 * was an error during the copying then it's finished by calling
1195 * request_end(). Otherwise add it to the processing list, and set
1198 static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
1199 struct fuse_copy_state *cs, size_t nbytes)
1202 struct fuse_req *req;
1207 spin_lock(&fc->lock);
1209 if ((file->f_flags & O_NONBLOCK) && fc->connected &&
1210 !request_pending(fc))
1218 if (!request_pending(fc))
1221 if (!list_empty(&fc->interrupts)) {
1222 req = list_entry(fc->interrupts.next, struct fuse_req,
1224 return fuse_read_interrupt(fc, cs, nbytes, req);
1227 if (forget_pending(fc)) {
1228 if (list_empty(&fc->pending) || fc->forget_batch-- > 0)
1229 return fuse_read_forget(fc, cs, nbytes);
1231 if (fc->forget_batch <= -8)
1232 fc->forget_batch = 16;
1235 req = list_entry(fc->pending.next, struct fuse_req, list);
1236 req->state = FUSE_REQ_READING;
1237 list_move(&req->list, &fc->io);
1240 reqsize = in->h.len;
1241 /* If request is too large, reply with an error and restart the read */
1242 if (nbytes < reqsize) {
1243 req->out.h.error = -EIO;
1244 /* SETXATTR is special, since it may contain too large data */
1245 if (in->h.opcode == FUSE_SETXATTR)
1246 req->out.h.error = -E2BIG;
1247 request_end(fc, req);
1250 spin_unlock(&fc->lock);
1252 err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1254 err = fuse_copy_args(cs, in->numargs, in->argpages,
1255 (struct fuse_arg *) in->args, 0);
1256 fuse_copy_finish(cs);
1257 spin_lock(&fc->lock);
1260 request_end(fc, req);
1264 req->out.h.error = -EIO;
1265 request_end(fc, req);
1269 request_end(fc, req);
1271 req->state = FUSE_REQ_SENT;
1272 list_move_tail(&req->list, &fc->processing);
1273 if (req->interrupted)
1274 queue_interrupt(fc, req);
1275 spin_unlock(&fc->lock);
1280 spin_unlock(&fc->lock);
1284 static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
1285 unsigned long nr_segs, loff_t pos)
1287 struct fuse_copy_state cs;
1288 struct file *file = iocb->ki_filp;
1289 struct fuse_conn *fc = fuse_get_conn(file);
1293 fuse_copy_init(&cs, fc, 1, iov, nr_segs);
1295 return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
1298 static int fuse_dev_pipe_buf_steal(struct pipe_inode_info *pipe,
1299 struct pipe_buffer *buf)
1304 static const struct pipe_buf_operations fuse_dev_pipe_buf_ops = {
1306 .map = generic_pipe_buf_map,
1307 .unmap = generic_pipe_buf_unmap,
1308 .confirm = generic_pipe_buf_confirm,
1309 .release = generic_pipe_buf_release,
1310 .steal = fuse_dev_pipe_buf_steal,
1311 .get = generic_pipe_buf_get,
1314 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1315 struct pipe_inode_info *pipe,
1316 size_t len, unsigned int flags)
1321 struct pipe_buffer *bufs;
1322 struct fuse_copy_state cs;
1323 struct fuse_conn *fc = fuse_get_conn(in);
1327 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1331 fuse_copy_init(&cs, fc, 1, NULL, 0);
1334 ret = fuse_dev_do_read(fc, in, &cs, len);
1341 if (!pipe->readers) {
1342 send_sig(SIGPIPE, current, 0);
1348 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1353 while (page_nr < cs.nr_segs) {
1354 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
1355 struct pipe_buffer *buf = pipe->bufs + newbuf;
1357 buf->page = bufs[page_nr].page;
1358 buf->offset = bufs[page_nr].offset;
1359 buf->len = bufs[page_nr].len;
1360 buf->ops = &fuse_dev_pipe_buf_ops;
1375 if (waitqueue_active(&pipe->wait))
1376 wake_up_interruptible(&pipe->wait);
1377 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
1381 for (; page_nr < cs.nr_segs; page_nr++)
1382 page_cache_release(bufs[page_nr].page);
1388 static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1389 struct fuse_copy_state *cs)
1391 struct fuse_notify_poll_wakeup_out outarg;
1394 if (size != sizeof(outarg))
1397 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1401 fuse_copy_finish(cs);
1402 return fuse_notify_poll_wakeup(fc, &outarg);
1405 fuse_copy_finish(cs);
1409 static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1410 struct fuse_copy_state *cs)
1412 struct fuse_notify_inval_inode_out outarg;
1415 if (size != sizeof(outarg))
1418 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1421 fuse_copy_finish(cs);
1423 down_read(&fc->killsb);
1426 err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1427 outarg.off, outarg.len);
1429 up_read(&fc->killsb);
1433 fuse_copy_finish(cs);
1437 static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1438 struct fuse_copy_state *cs)
1440 struct fuse_notify_inval_entry_out outarg;
1445 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1450 if (size < sizeof(outarg))
1453 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1457 err = -ENAMETOOLONG;
1458 if (outarg.namelen > FUSE_NAME_MAX)
1462 if (size != sizeof(outarg) + outarg.namelen + 1)
1466 name.len = outarg.namelen;
1467 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1470 fuse_copy_finish(cs);
1471 buf[outarg.namelen] = 0;
1472 name.hash = full_name_hash(name.name, name.len);
1474 down_read(&fc->killsb);
1477 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1478 up_read(&fc->killsb);
1484 fuse_copy_finish(cs);
1488 static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1489 struct fuse_copy_state *cs)
1491 struct fuse_notify_delete_out outarg;
1496 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1501 if (size < sizeof(outarg))
1504 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1508 err = -ENAMETOOLONG;
1509 if (outarg.namelen > FUSE_NAME_MAX)
1513 if (size != sizeof(outarg) + outarg.namelen + 1)
1517 name.len = outarg.namelen;
1518 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1521 fuse_copy_finish(cs);
1522 buf[outarg.namelen] = 0;
1523 name.hash = full_name_hash(name.name, name.len);
1525 down_read(&fc->killsb);
1528 err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1529 outarg.child, &name);
1530 up_read(&fc->killsb);
1536 fuse_copy_finish(cs);
1540 static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1541 struct fuse_copy_state *cs)
1543 struct fuse_notify_store_out outarg;
1544 struct inode *inode;
1545 struct address_space *mapping;
1549 unsigned int offset;
1555 if (size < sizeof(outarg))
1558 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1563 if (size - sizeof(outarg) != outarg.size)
1566 nodeid = outarg.nodeid;
1568 down_read(&fc->killsb);
1574 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1578 mapping = inode->i_mapping;
1579 index = outarg.offset >> PAGE_CACHE_SHIFT;
1580 offset = outarg.offset & ~PAGE_CACHE_MASK;
1581 file_size = i_size_read(inode);
1582 end = outarg.offset + outarg.size;
1583 if (end > file_size) {
1585 fuse_write_update_size(inode, file_size);
1591 unsigned int this_num;
1594 page = find_or_create_page(mapping, index,
1595 mapping_gfp_mask(mapping));
1599 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1600 err = fuse_copy_page(cs, &page, offset, this_num, 0);
1601 if (!err && offset == 0 && (num != 0 || file_size == end))
1602 SetPageUptodate(page);
1604 page_cache_release(page);
1619 up_read(&fc->killsb);
1621 fuse_copy_finish(cs);
1625 static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
1627 release_pages(req->pages, req->num_pages, 0);
1630 static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1631 struct fuse_notify_retrieve_out *outarg)
1634 struct address_space *mapping = inode->i_mapping;
1635 struct fuse_req *req;
1639 unsigned int offset;
1640 size_t total_len = 0;
1643 offset = outarg->offset & ~PAGE_CACHE_MASK;
1644 file_size = i_size_read(inode);
1647 if (outarg->offset > file_size)
1649 else if (outarg->offset + num > file_size)
1650 num = file_size - outarg->offset;
1652 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1653 num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
1655 req = fuse_get_req(fc, num_pages);
1657 return PTR_ERR(req);
1659 req->in.h.opcode = FUSE_NOTIFY_REPLY;
1660 req->in.h.nodeid = outarg->nodeid;
1661 req->in.numargs = 2;
1662 req->in.argpages = 1;
1663 req->page_descs[0].offset = offset;
1664 req->end = fuse_retrieve_end;
1666 index = outarg->offset >> PAGE_CACHE_SHIFT;
1668 while (num && req->num_pages < num_pages) {
1670 unsigned int this_num;
1672 page = find_get_page(mapping, index);
1676 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1677 req->pages[req->num_pages] = page;
1678 req->page_descs[req->num_pages].length = this_num;
1683 total_len += this_num;
1686 req->misc.retrieve_in.offset = outarg->offset;
1687 req->misc.retrieve_in.size = total_len;
1688 req->in.args[0].size = sizeof(req->misc.retrieve_in);
1689 req->in.args[0].value = &req->misc.retrieve_in;
1690 req->in.args[1].size = total_len;
1692 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1694 fuse_retrieve_end(fc, req);
1699 static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1700 struct fuse_copy_state *cs)
1702 struct fuse_notify_retrieve_out outarg;
1703 struct inode *inode;
1707 if (size != sizeof(outarg))
1710 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1714 fuse_copy_finish(cs);
1716 down_read(&fc->killsb);
1719 u64 nodeid = outarg.nodeid;
1721 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1723 err = fuse_retrieve(fc, inode, &outarg);
1727 up_read(&fc->killsb);
1732 fuse_copy_finish(cs);
1736 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1737 unsigned int size, struct fuse_copy_state *cs)
1740 case FUSE_NOTIFY_POLL:
1741 return fuse_notify_poll(fc, size, cs);
1743 case FUSE_NOTIFY_INVAL_INODE:
1744 return fuse_notify_inval_inode(fc, size, cs);
1746 case FUSE_NOTIFY_INVAL_ENTRY:
1747 return fuse_notify_inval_entry(fc, size, cs);
1749 case FUSE_NOTIFY_STORE:
1750 return fuse_notify_store(fc, size, cs);
1752 case FUSE_NOTIFY_RETRIEVE:
1753 return fuse_notify_retrieve(fc, size, cs);
1755 case FUSE_NOTIFY_DELETE:
1756 return fuse_notify_delete(fc, size, cs);
1759 fuse_copy_finish(cs);
1764 /* Look up request on processing list by unique ID */
1765 static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
1767 struct list_head *entry;
1769 list_for_each(entry, &fc->processing) {
1770 struct fuse_req *req;
1771 req = list_entry(entry, struct fuse_req, list);
1772 if (req->in.h.unique == unique || req->intr_unique == unique)
1778 static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1781 unsigned reqsize = sizeof(struct fuse_out_header);
1784 return nbytes != reqsize ? -EINVAL : 0;
1786 reqsize += len_args(out->numargs, out->args);
1788 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1790 else if (reqsize > nbytes) {
1791 struct fuse_arg *lastarg = &out->args[out->numargs-1];
1792 unsigned diffsize = reqsize - nbytes;
1793 if (diffsize > lastarg->size)
1795 lastarg->size -= diffsize;
1797 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1802 * Write a single reply to a request. First the header is copied from
1803 * the write buffer. The request is then searched on the processing
1804 * list by the unique ID found in the header. If found, then remove
1805 * it from the list and copy the rest of the buffer to the request.
1806 * The request is finished by calling request_end()
1808 static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
1809 struct fuse_copy_state *cs, size_t nbytes)
1812 struct fuse_req *req;
1813 struct fuse_out_header oh;
1815 if (nbytes < sizeof(struct fuse_out_header))
1818 err = fuse_copy_one(cs, &oh, sizeof(oh));
1823 if (oh.len != nbytes)
1827 * Zero oh.unique indicates unsolicited notification message
1828 * and error contains notification code.
1831 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
1832 return err ? err : nbytes;
1836 if (oh.error <= -1000 || oh.error > 0)
1839 spin_lock(&fc->lock);
1844 req = request_find(fc, oh.unique);
1849 spin_unlock(&fc->lock);
1850 fuse_copy_finish(cs);
1851 spin_lock(&fc->lock);
1852 request_end(fc, req);
1855 /* Is it an interrupt reply? */
1856 if (req->intr_unique == oh.unique) {
1858 if (nbytes != sizeof(struct fuse_out_header))
1861 if (oh.error == -ENOSYS)
1862 fc->no_interrupt = 1;
1863 else if (oh.error == -EAGAIN)
1864 queue_interrupt(fc, req);
1866 spin_unlock(&fc->lock);
1867 fuse_copy_finish(cs);
1871 req->state = FUSE_REQ_WRITING;
1872 list_move(&req->list, &fc->io);
1876 if (!req->out.page_replace)
1878 spin_unlock(&fc->lock);
1880 err = copy_out_args(cs, &req->out, nbytes);
1881 fuse_copy_finish(cs);
1883 spin_lock(&fc->lock);
1888 } else if (!req->aborted)
1889 req->out.h.error = -EIO;
1890 request_end(fc, req);
1892 return err ? err : nbytes;
1895 spin_unlock(&fc->lock);
1897 fuse_copy_finish(cs);
1901 static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
1902 unsigned long nr_segs, loff_t pos)
1904 struct fuse_copy_state cs;
1905 struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
1909 fuse_copy_init(&cs, fc, 0, iov, nr_segs);
1911 return fuse_dev_do_write(fc, &cs, iov_length(iov, nr_segs));
1914 static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1915 struct file *out, loff_t *ppos,
1916 size_t len, unsigned int flags)
1920 struct pipe_buffer *bufs;
1921 struct fuse_copy_state cs;
1922 struct fuse_conn *fc;
1926 fc = fuse_get_conn(out);
1930 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1937 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
1938 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
1948 struct pipe_buffer *ibuf;
1949 struct pipe_buffer *obuf;
1951 BUG_ON(nbuf >= pipe->buffers);
1952 BUG_ON(!pipe->nrbufs);
1953 ibuf = &pipe->bufs[pipe->curbuf];
1956 if (rem >= ibuf->len) {
1959 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
1962 ibuf->ops->get(pipe, ibuf);
1964 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
1966 ibuf->offset += obuf->len;
1967 ibuf->len -= obuf->len;
1974 fuse_copy_init(&cs, fc, 0, NULL, nbuf);
1978 if (flags & SPLICE_F_MOVE)
1981 ret = fuse_dev_do_write(fc, &cs, len);
1983 for (idx = 0; idx < nbuf; idx++) {
1984 struct pipe_buffer *buf = &bufs[idx];
1985 buf->ops->release(pipe, buf);
1992 static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
1994 unsigned mask = POLLOUT | POLLWRNORM;
1995 struct fuse_conn *fc = fuse_get_conn(file);
1999 poll_wait(file, &fc->waitq, wait);
2001 spin_lock(&fc->lock);
2004 else if (request_pending(fc))
2005 mask |= POLLIN | POLLRDNORM;
2006 spin_unlock(&fc->lock);
2012 * Abort all requests on the given list (pending or processing)
2014 * This function releases and reacquires fc->lock
2016 static void end_requests(struct fuse_conn *fc, struct list_head *head)
2017 __releases(fc->lock)
2018 __acquires(fc->lock)
2020 while (!list_empty(head)) {
2021 struct fuse_req *req;
2022 req = list_entry(head->next, struct fuse_req, list);
2023 req->out.h.error = -ECONNABORTED;
2024 request_end(fc, req);
2025 spin_lock(&fc->lock);
2030 * Abort requests under I/O
2032 * The requests are set to aborted and finished, and the request
2033 * waiter is woken up. This will make request_wait_answer() wait
2034 * until the request is unlocked and then return.
2036 * If the request is asynchronous, then the end function needs to be
2037 * called after waiting for the request to be unlocked (if it was
2040 static void end_io_requests(struct fuse_conn *fc)
2041 __releases(fc->lock)
2042 __acquires(fc->lock)
2044 while (!list_empty(&fc->io)) {
2045 struct fuse_req *req =
2046 list_entry(fc->io.next, struct fuse_req, list);
2047 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
2050 req->out.h.error = -ECONNABORTED;
2051 req->state = FUSE_REQ_FINISHED;
2052 list_del_init(&req->list);
2053 wake_up(&req->waitq);
2056 __fuse_get_request(req);
2057 spin_unlock(&fc->lock);
2058 wait_event(req->waitq, !req->locked);
2060 fuse_put_request(fc, req);
2061 spin_lock(&fc->lock);
2066 static void end_queued_requests(struct fuse_conn *fc)
2067 __releases(fc->lock)
2068 __acquires(fc->lock)
2070 fc->max_background = UINT_MAX;
2072 end_requests(fc, &fc->pending);
2073 end_requests(fc, &fc->processing);
2074 while (forget_pending(fc))
2075 kfree(dequeue_forget(fc, 1, NULL));
2078 static void end_polls(struct fuse_conn *fc)
2082 p = rb_first(&fc->polled_files);
2085 struct fuse_file *ff;
2086 ff = rb_entry(p, struct fuse_file, polled_node);
2087 wake_up_interruptible_all(&ff->poll_wait);
2094 * Abort all requests.
2096 * Emergency exit in case of a malicious or accidental deadlock, or
2097 * just a hung filesystem.
2099 * The same effect is usually achievable through killing the
2100 * filesystem daemon and all users of the filesystem. The exception
2101 * is the combination of an asynchronous request and the tricky
2102 * deadlock (see Documentation/filesystems/fuse.txt).
2104 * During the aborting, progression of requests from the pending and
2105 * processing lists onto the io list, and progression of new requests
2106 * onto the pending list is prevented by req->connected being false.
2108 * Progression of requests under I/O to the processing list is
2109 * prevented by the req->aborted flag being true for these requests.
2110 * For this reason requests on the io list must be aborted first.
2112 void fuse_abort_conn(struct fuse_conn *fc)
2114 spin_lock(&fc->lock);
2115 if (fc->connected) {
2118 fc->initialized = 1;
2119 end_io_requests(fc);
2120 end_queued_requests(fc);
2122 wake_up_all(&fc->waitq);
2123 wake_up_all(&fc->blocked_waitq);
2124 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
2126 spin_unlock(&fc->lock);
2128 EXPORT_SYMBOL_GPL(fuse_abort_conn);
2130 int fuse_dev_release(struct inode *inode, struct file *file)
2132 struct fuse_conn *fc = fuse_get_conn(file);
2134 spin_lock(&fc->lock);
2137 fc->initialized = 1;
2138 end_queued_requests(fc);
2140 wake_up_all(&fc->blocked_waitq);
2141 spin_unlock(&fc->lock);
2147 EXPORT_SYMBOL_GPL(fuse_dev_release);
2149 static int fuse_dev_fasync(int fd, struct file *file, int on)
2151 struct fuse_conn *fc = fuse_get_conn(file);
2155 /* No locking - fasync_helper does its own locking */
2156 return fasync_helper(fd, file, on, &fc->fasync);
2159 const struct file_operations fuse_dev_operations = {
2160 .owner = THIS_MODULE,
2161 .llseek = no_llseek,
2162 .read = do_sync_read,
2163 .aio_read = fuse_dev_read,
2164 .splice_read = fuse_dev_splice_read,
2165 .write = do_sync_write,
2166 .aio_write = fuse_dev_write,
2167 .splice_write = fuse_dev_splice_write,
2168 .poll = fuse_dev_poll,
2169 .release = fuse_dev_release,
2170 .fasync = fuse_dev_fasync,
2172 EXPORT_SYMBOL_GPL(fuse_dev_operations);
2174 static struct miscdevice fuse_miscdevice = {
2175 .minor = FUSE_MINOR,
2177 .fops = &fuse_dev_operations,
2180 int __init fuse_dev_init(void)
2183 fuse_req_cachep = kmem_cache_create("fuse_request",
2184 sizeof(struct fuse_req),
2186 if (!fuse_req_cachep)
2189 err = misc_register(&fuse_miscdevice);
2191 goto out_cache_clean;
2196 kmem_cache_destroy(fuse_req_cachep);
2201 void fuse_dev_cleanup(void)
2203 misc_deregister(&fuse_miscdevice);
2204 kmem_cache_destroy(fuse_req_cachep);