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>
22 #include <linux/aio.h>
23 #include <linux/freezer.h>
25 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
26 MODULE_ALIAS("devname:fuse");
28 static struct kmem_cache *fuse_req_cachep;
30 static struct fuse_conn *fuse_get_conn(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 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 atomic_set(&req->count, 1);
51 req->page_descs = page_descs;
52 req->max_pages = npages;
55 static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
57 struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags);
60 struct fuse_page_desc *page_descs;
62 if (npages <= FUSE_REQ_INLINE_PAGES) {
63 pages = req->inline_pages;
64 page_descs = req->inline_page_descs;
66 pages = kmalloc(sizeof(struct page *) * npages, flags);
67 page_descs = kmalloc(sizeof(struct fuse_page_desc) *
71 if (!pages || !page_descs) {
74 kmem_cache_free(fuse_req_cachep, req);
78 fuse_request_init(req, pages, page_descs, npages);
83 struct fuse_req *fuse_request_alloc(unsigned npages)
85 return __fuse_request_alloc(npages, GFP_KERNEL);
87 EXPORT_SYMBOL_GPL(fuse_request_alloc);
89 struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
91 return __fuse_request_alloc(npages, GFP_NOFS);
94 void fuse_request_free(struct fuse_req *req)
96 if (req->pages != req->inline_pages) {
98 kfree(req->page_descs);
100 kmem_cache_free(fuse_req_cachep, req);
103 static void block_sigs(sigset_t *oldset)
107 siginitsetinv(&mask, sigmask(SIGKILL));
108 sigprocmask(SIG_BLOCK, &mask, oldset);
111 static void restore_sigs(sigset_t *oldset)
113 sigprocmask(SIG_SETMASK, oldset, NULL);
116 void __fuse_get_request(struct fuse_req *req)
118 atomic_inc(&req->count);
121 /* Must be called with > 1 refcount */
122 static void __fuse_put_request(struct fuse_req *req)
124 BUG_ON(atomic_read(&req->count) < 2);
125 atomic_dec(&req->count);
128 static void fuse_req_init_context(struct fuse_req *req)
130 req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid());
131 req->in.h.gid = from_kgid_munged(&init_user_ns, current_fsgid());
132 req->in.h.pid = current->pid;
135 static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
137 return !fc->initialized || (for_background && fc->blocked);
140 static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
143 struct fuse_req *req;
145 atomic_inc(&fc->num_waiting);
147 if (fuse_block_alloc(fc, for_background)) {
152 intr = wait_event_interruptible_exclusive(fc->blocked_waitq,
153 !fuse_block_alloc(fc, for_background));
154 restore_sigs(&oldset);
164 req = fuse_request_alloc(npages);
168 wake_up(&fc->blocked_waitq);
172 fuse_req_init_context(req);
174 req->background = for_background;
178 atomic_dec(&fc->num_waiting);
182 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
184 return __fuse_get_req(fc, npages, false);
186 EXPORT_SYMBOL_GPL(fuse_get_req);
188 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
191 return __fuse_get_req(fc, npages, true);
193 EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
196 * Return request in fuse_file->reserved_req. However that may
197 * currently be in use. If that is the case, wait for it to become
200 static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
203 struct fuse_req *req = NULL;
204 struct fuse_file *ff = file->private_data;
207 wait_event(fc->reserved_req_waitq, ff->reserved_req);
208 spin_lock(&fc->lock);
209 if (ff->reserved_req) {
210 req = ff->reserved_req;
211 ff->reserved_req = NULL;
212 req->stolen_file = get_file(file);
214 spin_unlock(&fc->lock);
221 * Put stolen request back into fuse_file->reserved_req
223 static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
225 struct file *file = req->stolen_file;
226 struct fuse_file *ff = file->private_data;
228 spin_lock(&fc->lock);
229 fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
230 BUG_ON(ff->reserved_req);
231 ff->reserved_req = req;
232 wake_up_all(&fc->reserved_req_waitq);
233 spin_unlock(&fc->lock);
238 * Gets a requests for a file operation, always succeeds
240 * This is used for sending the FLUSH request, which must get to
241 * userspace, due to POSIX locks which may need to be unlocked.
243 * If allocation fails due to OOM, use the reserved request in
246 * This is very unlikely to deadlock accidentally, since the
247 * filesystem should not have it's own file open. If deadlock is
248 * intentional, it can still be broken by "aborting" the filesystem.
250 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
253 struct fuse_req *req;
255 atomic_inc(&fc->num_waiting);
256 wait_event(fc->blocked_waitq, fc->initialized);
257 req = fuse_request_alloc(0);
259 req = get_reserved_req(fc, file);
261 fuse_req_init_context(req);
267 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
269 if (atomic_dec_and_test(&req->count)) {
270 if (unlikely(req->background)) {
272 * We get here in the unlikely case that a background
273 * request was allocated but not sent
275 spin_lock(&fc->lock);
277 wake_up(&fc->blocked_waitq);
278 spin_unlock(&fc->lock);
282 atomic_dec(&fc->num_waiting);
284 if (req->stolen_file)
285 put_reserved_req(fc, req);
287 fuse_request_free(req);
290 EXPORT_SYMBOL_GPL(fuse_put_request);
292 static unsigned len_args(unsigned numargs, struct fuse_arg *args)
297 for (i = 0; i < numargs; i++)
298 nbytes += args[i].size;
303 static u64 fuse_get_unique(struct fuse_conn *fc)
306 /* zero is special */
313 static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
315 req->in.h.len = sizeof(struct fuse_in_header) +
316 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
317 list_add_tail(&req->list, &fc->pending);
318 req->state = FUSE_REQ_PENDING;
321 atomic_inc(&fc->num_waiting);
324 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
327 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
328 u64 nodeid, u64 nlookup)
330 forget->forget_one.nodeid = nodeid;
331 forget->forget_one.nlookup = nlookup;
333 spin_lock(&fc->lock);
335 fc->forget_list_tail->next = forget;
336 fc->forget_list_tail = forget;
338 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
342 spin_unlock(&fc->lock);
345 static void flush_bg_queue(struct fuse_conn *fc)
347 while (fc->active_background < fc->max_background &&
348 !list_empty(&fc->bg_queue)) {
349 struct fuse_req *req;
351 req = list_entry(fc->bg_queue.next, struct fuse_req, list);
352 list_del(&req->list);
353 fc->active_background++;
354 req->in.h.unique = fuse_get_unique(fc);
355 queue_request(fc, req);
360 * This function is called when a request is finished. Either a reply
361 * has arrived or it was aborted (and not yet sent) or some error
362 * occurred during communication with userspace, or the device file
363 * was closed. The requester thread is woken up (if still waiting),
364 * the 'end' callback is called if given, else the reference to the
365 * request is released
367 * Called with fc->lock, unlocks it
369 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
372 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
374 list_del(&req->list);
375 list_del(&req->intr_entry);
376 req->state = FUSE_REQ_FINISHED;
377 if (req->background) {
380 if (fc->num_background == fc->max_background)
383 /* Wake up next waiter, if any */
384 if (!fc->blocked && waitqueue_active(&fc->blocked_waitq))
385 wake_up(&fc->blocked_waitq);
387 if (fc->num_background == fc->congestion_threshold &&
388 fc->connected && fc->bdi_initialized) {
389 clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
390 clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
392 fc->num_background--;
393 fc->active_background--;
396 spin_unlock(&fc->lock);
397 wake_up(&req->waitq);
400 fuse_put_request(fc, req);
403 static void wait_answer_interruptible(struct fuse_conn *fc,
404 struct fuse_req *req)
408 if (signal_pending(current))
411 spin_unlock(&fc->lock);
412 wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
413 spin_lock(&fc->lock);
416 static void queue_interrupt(struct fuse_conn *fc, struct fuse_req *req)
418 list_add_tail(&req->intr_entry, &fc->interrupts);
420 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
423 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
427 if (!fc->no_interrupt) {
428 /* Any signal may interrupt this */
429 wait_answer_interruptible(fc, req);
433 if (req->state == FUSE_REQ_FINISHED)
436 req->interrupted = 1;
437 if (req->state == FUSE_REQ_SENT)
438 queue_interrupt(fc, req);
444 /* Only fatal signals may interrupt this */
446 wait_answer_interruptible(fc, req);
447 restore_sigs(&oldset);
451 if (req->state == FUSE_REQ_FINISHED)
454 /* Request is not yet in userspace, bail out */
455 if (req->state == FUSE_REQ_PENDING) {
456 list_del(&req->list);
457 __fuse_put_request(req);
458 req->out.h.error = -EINTR;
464 * Either request is already in userspace, or it was forced.
467 spin_unlock(&fc->lock);
469 while (req->state != FUSE_REQ_FINISHED)
470 wait_event_freezable(req->waitq,
471 req->state == FUSE_REQ_FINISHED);
472 spin_lock(&fc->lock);
478 BUG_ON(req->state != FUSE_REQ_FINISHED);
480 /* This is uninterruptible sleep, because data is
481 being copied to/from the buffers of req. During
482 locked state, there mustn't be any filesystem
483 operation (e.g. page fault), since that could lead
485 spin_unlock(&fc->lock);
486 wait_event(req->waitq, !req->locked);
487 spin_lock(&fc->lock);
491 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
493 BUG_ON(req->background);
494 spin_lock(&fc->lock);
496 req->out.h.error = -ENOTCONN;
497 else if (fc->conn_error)
498 req->out.h.error = -ECONNREFUSED;
500 req->in.h.unique = fuse_get_unique(fc);
501 queue_request(fc, req);
502 /* acquire extra reference, since request is still needed
503 after request_end() */
504 __fuse_get_request(req);
506 request_wait_answer(fc, req);
508 spin_unlock(&fc->lock);
511 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
514 __fuse_request_send(fc, req);
516 EXPORT_SYMBOL_GPL(fuse_request_send);
518 static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
519 struct fuse_req *req)
521 BUG_ON(!req->background);
522 fc->num_background++;
523 if (fc->num_background == fc->max_background)
525 if (fc->num_background == fc->congestion_threshold &&
526 fc->bdi_initialized) {
527 set_bdi_congested(&fc->bdi, BLK_RW_SYNC);
528 set_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
530 list_add_tail(&req->list, &fc->bg_queue);
534 static void fuse_request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
536 spin_lock(&fc->lock);
538 fuse_request_send_nowait_locked(fc, req);
539 spin_unlock(&fc->lock);
541 req->out.h.error = -ENOTCONN;
542 request_end(fc, req);
546 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
549 fuse_request_send_nowait(fc, req);
551 EXPORT_SYMBOL_GPL(fuse_request_send_background);
553 static int fuse_request_send_notify_reply(struct fuse_conn *fc,
554 struct fuse_req *req, u64 unique)
559 req->in.h.unique = unique;
560 spin_lock(&fc->lock);
562 queue_request(fc, req);
565 spin_unlock(&fc->lock);
571 * Called under fc->lock
573 * fc->connected must have been checked previously
575 void fuse_request_send_background_locked(struct fuse_conn *fc,
576 struct fuse_req *req)
579 fuse_request_send_nowait_locked(fc, req);
582 void fuse_force_forget(struct file *file, u64 nodeid)
584 struct inode *inode = file_inode(file);
585 struct fuse_conn *fc = get_fuse_conn(inode);
586 struct fuse_req *req;
587 struct fuse_forget_in inarg;
589 memset(&inarg, 0, sizeof(inarg));
591 req = fuse_get_req_nofail_nopages(fc, file);
592 req->in.h.opcode = FUSE_FORGET;
593 req->in.h.nodeid = nodeid;
595 req->in.args[0].size = sizeof(inarg);
596 req->in.args[0].value = &inarg;
598 __fuse_request_send(fc, req);
600 fuse_put_request(fc, req);
604 * Lock the request. Up to the next unlock_request() there mustn't be
605 * anything that could cause a page-fault. If the request was already
608 static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
612 spin_lock(&fc->lock);
617 spin_unlock(&fc->lock);
623 * Unlock request. If it was aborted during being locked, the
624 * requester thread is currently waiting for it to be unlocked, so
627 static void unlock_request(struct fuse_conn *fc, struct fuse_req *req)
630 spin_lock(&fc->lock);
633 wake_up(&req->waitq);
634 spin_unlock(&fc->lock);
638 struct fuse_copy_state {
639 struct fuse_conn *fc;
641 struct fuse_req *req;
642 const struct iovec *iov;
643 struct pipe_buffer *pipebufs;
644 struct pipe_buffer *currbuf;
645 struct pipe_inode_info *pipe;
646 unsigned long nr_segs;
647 unsigned long seglen;
653 unsigned move_pages:1;
656 static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
658 const struct iovec *iov, unsigned long nr_segs)
660 memset(cs, 0, sizeof(*cs));
664 cs->nr_segs = nr_segs;
667 /* Unmap and put previous page of userspace buffer */
668 static void fuse_copy_finish(struct fuse_copy_state *cs)
671 struct pipe_buffer *buf = cs->currbuf;
674 buf->ops->unmap(cs->pipe, buf, cs->mapaddr);
677 buf->len = PAGE_SIZE - cs->len;
681 } else if (cs->mapaddr) {
684 flush_dcache_page(cs->pg);
685 set_page_dirty_lock(cs->pg);
693 * Get another pagefull of userspace buffer, and map it to kernel
694 * address space, and lock request
696 static int fuse_copy_fill(struct fuse_copy_state *cs)
698 unsigned long offset;
701 unlock_request(cs->fc, cs->req);
702 fuse_copy_finish(cs);
704 struct pipe_buffer *buf = cs->pipebufs;
707 err = buf->ops->confirm(cs->pipe, buf);
711 BUG_ON(!cs->nr_segs);
713 cs->mapaddr = buf->ops->map(cs->pipe, buf, 0);
715 cs->buf = cs->mapaddr + buf->offset;
721 if (cs->nr_segs == cs->pipe->buffers)
724 page = alloc_page(GFP_HIGHUSER);
733 cs->mapaddr = kmap(page);
734 cs->buf = cs->mapaddr;
741 BUG_ON(!cs->nr_segs);
742 cs->seglen = cs->iov[0].iov_len;
743 cs->addr = (unsigned long) cs->iov[0].iov_base;
747 err = get_user_pages_fast(cs->addr, 1, cs->write, &cs->pg);
751 offset = cs->addr % PAGE_SIZE;
752 cs->mapaddr = kmap(cs->pg);
753 cs->buf = cs->mapaddr + offset;
754 cs->len = min(PAGE_SIZE - offset, cs->seglen);
755 cs->seglen -= cs->len;
759 return lock_request(cs->fc, cs->req);
762 /* Do as much copy to/from userspace buffer as we can */
763 static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
765 unsigned ncpy = min(*size, cs->len);
768 memcpy(cs->buf, *val, ncpy);
770 memcpy(*val, cs->buf, ncpy);
779 static int fuse_check_page(struct page *page)
781 if (page_mapcount(page) ||
782 page->mapping != NULL ||
783 page_count(page) != 1 ||
784 (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
791 printk(KERN_WARNING "fuse: trying to steal weird page\n");
792 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);
798 static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
801 struct page *oldpage = *pagep;
802 struct page *newpage;
803 struct pipe_buffer *buf = cs->pipebufs;
805 unlock_request(cs->fc, cs->req);
806 fuse_copy_finish(cs);
808 err = buf->ops->confirm(cs->pipe, buf);
812 BUG_ON(!cs->nr_segs);
818 if (cs->len != PAGE_SIZE)
821 if (buf->ops->steal(cs->pipe, buf) != 0)
826 if (WARN_ON(!PageUptodate(newpage)))
829 ClearPageMappedToDisk(newpage);
831 if (fuse_check_page(newpage) != 0)
832 goto out_fallback_unlock;
835 * This is a new and locked page, it shouldn't be mapped or
836 * have any special flags on it
838 if (WARN_ON(page_mapped(oldpage)))
839 goto out_fallback_unlock;
840 if (WARN_ON(page_has_private(oldpage)))
841 goto out_fallback_unlock;
842 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
843 goto out_fallback_unlock;
844 if (WARN_ON(PageMlocked(oldpage)))
845 goto out_fallback_unlock;
847 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
849 unlock_page(newpage);
853 page_cache_get(newpage);
855 if (!(buf->flags & PIPE_BUF_FLAG_LRU))
856 lru_cache_add_file(newpage);
859 spin_lock(&cs->fc->lock);
860 if (cs->req->aborted)
864 spin_unlock(&cs->fc->lock);
867 unlock_page(newpage);
868 page_cache_release(newpage);
872 unlock_page(oldpage);
873 page_cache_release(oldpage);
879 unlock_page(newpage);
881 cs->mapaddr = buf->ops->map(cs->pipe, buf, 1);
882 cs->buf = cs->mapaddr + buf->offset;
884 err = lock_request(cs->fc, cs->req);
891 static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
892 unsigned offset, unsigned count)
894 struct pipe_buffer *buf;
896 if (cs->nr_segs == cs->pipe->buffers)
899 unlock_request(cs->fc, cs->req);
900 fuse_copy_finish(cs);
903 page_cache_get(page);
905 buf->offset = offset;
916 * Copy a page in the request to/from the userspace buffer. Must be
919 static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
920 unsigned offset, unsigned count, int zeroing)
923 struct page *page = *pagep;
925 if (page && zeroing && count < PAGE_SIZE)
926 clear_highpage(page);
929 if (cs->write && cs->pipebufs && page) {
930 return fuse_ref_page(cs, page, offset, count);
931 } else if (!cs->len) {
932 if (cs->move_pages && page &&
933 offset == 0 && count == PAGE_SIZE) {
934 err = fuse_try_move_page(cs, pagep);
938 err = fuse_copy_fill(cs);
944 void *mapaddr = kmap_atomic(page);
945 void *buf = mapaddr + offset;
946 offset += fuse_copy_do(cs, &buf, &count);
947 kunmap_atomic(mapaddr);
949 offset += fuse_copy_do(cs, NULL, &count);
951 if (page && !cs->write)
952 flush_dcache_page(page);
956 /* Copy pages in the request to/from userspace buffer */
957 static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
961 struct fuse_req *req = cs->req;
963 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
965 unsigned offset = req->page_descs[i].offset;
966 unsigned count = min(nbytes, req->page_descs[i].length);
968 err = fuse_copy_page(cs, &req->pages[i], offset, count,
978 /* Copy a single argument in the request to/from userspace buffer */
979 static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
983 int err = fuse_copy_fill(cs);
987 fuse_copy_do(cs, &val, &size);
992 /* Copy request arguments to/from userspace buffer */
993 static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
994 unsigned argpages, struct fuse_arg *args,
1000 for (i = 0; !err && i < numargs; i++) {
1001 struct fuse_arg *arg = &args[i];
1002 if (i == numargs - 1 && argpages)
1003 err = fuse_copy_pages(cs, arg->size, zeroing);
1005 err = fuse_copy_one(cs, arg->value, arg->size);
1010 static int forget_pending(struct fuse_conn *fc)
1012 return fc->forget_list_head.next != NULL;
1015 static int request_pending(struct fuse_conn *fc)
1017 return !list_empty(&fc->pending) || !list_empty(&fc->interrupts) ||
1021 /* Wait until a request is available on the pending list */
1022 static void request_wait(struct fuse_conn *fc)
1023 __releases(fc->lock)
1024 __acquires(fc->lock)
1026 DECLARE_WAITQUEUE(wait, current);
1028 add_wait_queue_exclusive(&fc->waitq, &wait);
1029 while (fc->connected && !request_pending(fc)) {
1030 set_current_state(TASK_INTERRUPTIBLE);
1031 if (signal_pending(current))
1034 spin_unlock(&fc->lock);
1036 spin_lock(&fc->lock);
1038 set_current_state(TASK_RUNNING);
1039 remove_wait_queue(&fc->waitq, &wait);
1043 * Transfer an interrupt request to userspace
1045 * Unlike other requests this is assembled on demand, without a need
1046 * to allocate a separate fuse_req structure.
1048 * Called with fc->lock held, releases it
1050 static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_copy_state *cs,
1051 size_t nbytes, struct fuse_req *req)
1052 __releases(fc->lock)
1054 struct fuse_in_header ih;
1055 struct fuse_interrupt_in arg;
1056 unsigned reqsize = sizeof(ih) + sizeof(arg);
1059 list_del_init(&req->intr_entry);
1060 req->intr_unique = fuse_get_unique(fc);
1061 memset(&ih, 0, sizeof(ih));
1062 memset(&arg, 0, sizeof(arg));
1064 ih.opcode = FUSE_INTERRUPT;
1065 ih.unique = req->intr_unique;
1066 arg.unique = req->in.h.unique;
1068 spin_unlock(&fc->lock);
1069 if (nbytes < reqsize)
1072 err = fuse_copy_one(cs, &ih, sizeof(ih));
1074 err = fuse_copy_one(cs, &arg, sizeof(arg));
1075 fuse_copy_finish(cs);
1077 return err ? err : reqsize;
1080 static struct fuse_forget_link *dequeue_forget(struct fuse_conn *fc,
1084 struct fuse_forget_link *head = fc->forget_list_head.next;
1085 struct fuse_forget_link **newhead = &head;
1088 for (count = 0; *newhead != NULL && count < max; count++)
1089 newhead = &(*newhead)->next;
1091 fc->forget_list_head.next = *newhead;
1093 if (fc->forget_list_head.next == NULL)
1094 fc->forget_list_tail = &fc->forget_list_head;
1102 static int fuse_read_single_forget(struct fuse_conn *fc,
1103 struct fuse_copy_state *cs,
1105 __releases(fc->lock)
1108 struct fuse_forget_link *forget = dequeue_forget(fc, 1, NULL);
1109 struct fuse_forget_in arg = {
1110 .nlookup = forget->forget_one.nlookup,
1112 struct fuse_in_header ih = {
1113 .opcode = FUSE_FORGET,
1114 .nodeid = forget->forget_one.nodeid,
1115 .unique = fuse_get_unique(fc),
1116 .len = sizeof(ih) + sizeof(arg),
1119 spin_unlock(&fc->lock);
1121 if (nbytes < ih.len)
1124 err = fuse_copy_one(cs, &ih, sizeof(ih));
1126 err = fuse_copy_one(cs, &arg, sizeof(arg));
1127 fuse_copy_finish(cs);
1135 static int fuse_read_batch_forget(struct fuse_conn *fc,
1136 struct fuse_copy_state *cs, size_t nbytes)
1137 __releases(fc->lock)
1140 unsigned max_forgets;
1142 struct fuse_forget_link *head;
1143 struct fuse_batch_forget_in arg = { .count = 0 };
1144 struct fuse_in_header ih = {
1145 .opcode = FUSE_BATCH_FORGET,
1146 .unique = fuse_get_unique(fc),
1147 .len = sizeof(ih) + sizeof(arg),
1150 if (nbytes < ih.len) {
1151 spin_unlock(&fc->lock);
1155 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
1156 head = dequeue_forget(fc, max_forgets, &count);
1157 spin_unlock(&fc->lock);
1160 ih.len += count * sizeof(struct fuse_forget_one);
1161 err = fuse_copy_one(cs, &ih, sizeof(ih));
1163 err = fuse_copy_one(cs, &arg, sizeof(arg));
1166 struct fuse_forget_link *forget = head;
1169 err = fuse_copy_one(cs, &forget->forget_one,
1170 sizeof(forget->forget_one));
1172 head = forget->next;
1176 fuse_copy_finish(cs);
1184 static int fuse_read_forget(struct fuse_conn *fc, struct fuse_copy_state *cs,
1186 __releases(fc->lock)
1188 if (fc->minor < 16 || fc->forget_list_head.next->next == NULL)
1189 return fuse_read_single_forget(fc, cs, nbytes);
1191 return fuse_read_batch_forget(fc, cs, nbytes);
1195 * Read a single request into the userspace filesystem's buffer. This
1196 * function waits until a request is available, then removes it from
1197 * the pending list and copies request data to userspace buffer. If
1198 * no reply is needed (FORGET) or request has been aborted or there
1199 * was an error during the copying then it's finished by calling
1200 * request_end(). Otherwise add it to the processing list, and set
1203 static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
1204 struct fuse_copy_state *cs, size_t nbytes)
1207 struct fuse_req *req;
1212 spin_lock(&fc->lock);
1214 if ((file->f_flags & O_NONBLOCK) && fc->connected &&
1215 !request_pending(fc))
1223 if (!request_pending(fc))
1226 if (!list_empty(&fc->interrupts)) {
1227 req = list_entry(fc->interrupts.next, struct fuse_req,
1229 return fuse_read_interrupt(fc, cs, nbytes, req);
1232 if (forget_pending(fc)) {
1233 if (list_empty(&fc->pending) || fc->forget_batch-- > 0)
1234 return fuse_read_forget(fc, cs, nbytes);
1236 if (fc->forget_batch <= -8)
1237 fc->forget_batch = 16;
1240 req = list_entry(fc->pending.next, struct fuse_req, list);
1241 req->state = FUSE_REQ_READING;
1242 list_move(&req->list, &fc->io);
1245 reqsize = in->h.len;
1246 /* If request is too large, reply with an error and restart the read */
1247 if (nbytes < reqsize) {
1248 req->out.h.error = -EIO;
1249 /* SETXATTR is special, since it may contain too large data */
1250 if (in->h.opcode == FUSE_SETXATTR)
1251 req->out.h.error = -E2BIG;
1252 request_end(fc, req);
1255 spin_unlock(&fc->lock);
1257 err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1259 err = fuse_copy_args(cs, in->numargs, in->argpages,
1260 (struct fuse_arg *) in->args, 0);
1261 fuse_copy_finish(cs);
1262 spin_lock(&fc->lock);
1265 request_end(fc, req);
1269 req->out.h.error = -EIO;
1270 request_end(fc, req);
1274 request_end(fc, req);
1276 req->state = FUSE_REQ_SENT;
1277 list_move_tail(&req->list, &fc->processing);
1278 if (req->interrupted)
1279 queue_interrupt(fc, req);
1280 spin_unlock(&fc->lock);
1285 spin_unlock(&fc->lock);
1289 static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
1290 unsigned long nr_segs, loff_t pos)
1292 struct fuse_copy_state cs;
1293 struct file *file = iocb->ki_filp;
1294 struct fuse_conn *fc = fuse_get_conn(file);
1298 fuse_copy_init(&cs, fc, 1, iov, nr_segs);
1300 return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
1303 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1304 struct pipe_inode_info *pipe,
1305 size_t len, unsigned int flags)
1310 struct pipe_buffer *bufs;
1311 struct fuse_copy_state cs;
1312 struct fuse_conn *fc = fuse_get_conn(in);
1316 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1320 fuse_copy_init(&cs, fc, 1, NULL, 0);
1323 ret = fuse_dev_do_read(fc, in, &cs, len);
1330 if (!pipe->readers) {
1331 send_sig(SIGPIPE, current, 0);
1337 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1342 while (page_nr < cs.nr_segs) {
1343 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
1344 struct pipe_buffer *buf = pipe->bufs + newbuf;
1346 buf->page = bufs[page_nr].page;
1347 buf->offset = bufs[page_nr].offset;
1348 buf->len = bufs[page_nr].len;
1350 * Need to be careful about this. Having buf->ops in module
1351 * code can Oops if the buffer persists after module unload.
1353 buf->ops = &nosteal_pipe_buf_ops;
1368 if (waitqueue_active(&pipe->wait))
1369 wake_up_interruptible(&pipe->wait);
1370 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
1374 for (; page_nr < cs.nr_segs; page_nr++)
1375 page_cache_release(bufs[page_nr].page);
1381 static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1382 struct fuse_copy_state *cs)
1384 struct fuse_notify_poll_wakeup_out outarg;
1387 if (size != sizeof(outarg))
1390 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1394 fuse_copy_finish(cs);
1395 return fuse_notify_poll_wakeup(fc, &outarg);
1398 fuse_copy_finish(cs);
1402 static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1403 struct fuse_copy_state *cs)
1405 struct fuse_notify_inval_inode_out outarg;
1408 if (size != sizeof(outarg))
1411 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1414 fuse_copy_finish(cs);
1416 down_read(&fc->killsb);
1419 err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1420 outarg.off, outarg.len);
1422 up_read(&fc->killsb);
1426 fuse_copy_finish(cs);
1430 static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1431 struct fuse_copy_state *cs)
1433 struct fuse_notify_inval_entry_out outarg;
1438 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1443 if (size < sizeof(outarg))
1446 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1450 err = -ENAMETOOLONG;
1451 if (outarg.namelen > FUSE_NAME_MAX)
1455 if (size != sizeof(outarg) + outarg.namelen + 1)
1459 name.len = outarg.namelen;
1460 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1463 fuse_copy_finish(cs);
1464 buf[outarg.namelen] = 0;
1465 name.hash = full_name_hash(name.name, name.len);
1467 down_read(&fc->killsb);
1470 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1471 up_read(&fc->killsb);
1477 fuse_copy_finish(cs);
1481 static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1482 struct fuse_copy_state *cs)
1484 struct fuse_notify_delete_out outarg;
1489 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1494 if (size < sizeof(outarg))
1497 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1501 err = -ENAMETOOLONG;
1502 if (outarg.namelen > FUSE_NAME_MAX)
1506 if (size != sizeof(outarg) + outarg.namelen + 1)
1510 name.len = outarg.namelen;
1511 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1514 fuse_copy_finish(cs);
1515 buf[outarg.namelen] = 0;
1516 name.hash = full_name_hash(name.name, name.len);
1518 down_read(&fc->killsb);
1521 err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1522 outarg.child, &name);
1523 up_read(&fc->killsb);
1529 fuse_copy_finish(cs);
1533 static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1534 struct fuse_copy_state *cs)
1536 struct fuse_notify_store_out outarg;
1537 struct inode *inode;
1538 struct address_space *mapping;
1542 unsigned int offset;
1548 if (size < sizeof(outarg))
1551 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1556 if (size - sizeof(outarg) != outarg.size)
1559 nodeid = outarg.nodeid;
1561 down_read(&fc->killsb);
1567 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1571 mapping = inode->i_mapping;
1572 index = outarg.offset >> PAGE_CACHE_SHIFT;
1573 offset = outarg.offset & ~PAGE_CACHE_MASK;
1574 file_size = i_size_read(inode);
1575 end = outarg.offset + outarg.size;
1576 if (end > file_size) {
1578 fuse_write_update_size(inode, file_size);
1584 unsigned int this_num;
1587 page = find_or_create_page(mapping, index,
1588 mapping_gfp_mask(mapping));
1592 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1593 err = fuse_copy_page(cs, &page, offset, this_num, 0);
1594 if (!err && offset == 0 && (num != 0 || file_size == end))
1595 SetPageUptodate(page);
1597 page_cache_release(page);
1612 up_read(&fc->killsb);
1614 fuse_copy_finish(cs);
1618 static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
1620 release_pages(req->pages, req->num_pages, 0);
1623 static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1624 struct fuse_notify_retrieve_out *outarg)
1627 struct address_space *mapping = inode->i_mapping;
1628 struct fuse_req *req;
1632 unsigned int offset;
1633 size_t total_len = 0;
1636 offset = outarg->offset & ~PAGE_CACHE_MASK;
1637 file_size = i_size_read(inode);
1640 if (outarg->offset > file_size)
1642 else if (outarg->offset + num > file_size)
1643 num = file_size - outarg->offset;
1645 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1646 num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
1648 req = fuse_get_req(fc, num_pages);
1650 return PTR_ERR(req);
1652 req->in.h.opcode = FUSE_NOTIFY_REPLY;
1653 req->in.h.nodeid = outarg->nodeid;
1654 req->in.numargs = 2;
1655 req->in.argpages = 1;
1656 req->page_descs[0].offset = offset;
1657 req->end = fuse_retrieve_end;
1659 index = outarg->offset >> PAGE_CACHE_SHIFT;
1661 while (num && req->num_pages < num_pages) {
1663 unsigned int this_num;
1665 page = find_get_page(mapping, index);
1669 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1670 req->pages[req->num_pages] = page;
1671 req->page_descs[req->num_pages].length = this_num;
1676 total_len += this_num;
1679 req->misc.retrieve_in.offset = outarg->offset;
1680 req->misc.retrieve_in.size = total_len;
1681 req->in.args[0].size = sizeof(req->misc.retrieve_in);
1682 req->in.args[0].value = &req->misc.retrieve_in;
1683 req->in.args[1].size = total_len;
1685 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1687 fuse_retrieve_end(fc, req);
1692 static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1693 struct fuse_copy_state *cs)
1695 struct fuse_notify_retrieve_out outarg;
1696 struct inode *inode;
1700 if (size != sizeof(outarg))
1703 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1707 fuse_copy_finish(cs);
1709 down_read(&fc->killsb);
1712 u64 nodeid = outarg.nodeid;
1714 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1716 err = fuse_retrieve(fc, inode, &outarg);
1720 up_read(&fc->killsb);
1725 fuse_copy_finish(cs);
1729 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1730 unsigned int size, struct fuse_copy_state *cs)
1733 case FUSE_NOTIFY_POLL:
1734 return fuse_notify_poll(fc, size, cs);
1736 case FUSE_NOTIFY_INVAL_INODE:
1737 return fuse_notify_inval_inode(fc, size, cs);
1739 case FUSE_NOTIFY_INVAL_ENTRY:
1740 return fuse_notify_inval_entry(fc, size, cs);
1742 case FUSE_NOTIFY_STORE:
1743 return fuse_notify_store(fc, size, cs);
1745 case FUSE_NOTIFY_RETRIEVE:
1746 return fuse_notify_retrieve(fc, size, cs);
1748 case FUSE_NOTIFY_DELETE:
1749 return fuse_notify_delete(fc, size, cs);
1752 fuse_copy_finish(cs);
1757 /* Look up request on processing list by unique ID */
1758 static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
1760 struct list_head *entry;
1762 list_for_each(entry, &fc->processing) {
1763 struct fuse_req *req;
1764 req = list_entry(entry, struct fuse_req, list);
1765 if (req->in.h.unique == unique || req->intr_unique == unique)
1771 static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1774 unsigned reqsize = sizeof(struct fuse_out_header);
1777 return nbytes != reqsize ? -EINVAL : 0;
1779 reqsize += len_args(out->numargs, out->args);
1781 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1783 else if (reqsize > nbytes) {
1784 struct fuse_arg *lastarg = &out->args[out->numargs-1];
1785 unsigned diffsize = reqsize - nbytes;
1786 if (diffsize > lastarg->size)
1788 lastarg->size -= diffsize;
1790 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1795 * Write a single reply to a request. First the header is copied from
1796 * the write buffer. The request is then searched on the processing
1797 * list by the unique ID found in the header. If found, then remove
1798 * it from the list and copy the rest of the buffer to the request.
1799 * The request is finished by calling request_end()
1801 static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
1802 struct fuse_copy_state *cs, size_t nbytes)
1805 struct fuse_req *req;
1806 struct fuse_out_header oh;
1808 if (nbytes < sizeof(struct fuse_out_header))
1811 err = fuse_copy_one(cs, &oh, sizeof(oh));
1816 if (oh.len != nbytes)
1820 * Zero oh.unique indicates unsolicited notification message
1821 * and error contains notification code.
1824 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
1825 return err ? err : nbytes;
1829 if (oh.error <= -1000 || oh.error > 0)
1832 spin_lock(&fc->lock);
1837 req = request_find(fc, oh.unique);
1842 spin_unlock(&fc->lock);
1843 fuse_copy_finish(cs);
1844 spin_lock(&fc->lock);
1845 request_end(fc, req);
1848 /* Is it an interrupt reply? */
1849 if (req->intr_unique == oh.unique) {
1851 if (nbytes != sizeof(struct fuse_out_header))
1854 if (oh.error == -ENOSYS)
1855 fc->no_interrupt = 1;
1856 else if (oh.error == -EAGAIN)
1857 queue_interrupt(fc, req);
1859 spin_unlock(&fc->lock);
1860 fuse_copy_finish(cs);
1864 req->state = FUSE_REQ_WRITING;
1865 list_move(&req->list, &fc->io);
1869 if (!req->out.page_replace)
1871 spin_unlock(&fc->lock);
1873 err = copy_out_args(cs, &req->out, nbytes);
1874 fuse_copy_finish(cs);
1876 spin_lock(&fc->lock);
1881 } else if (!req->aborted)
1882 req->out.h.error = -EIO;
1883 request_end(fc, req);
1885 return err ? err : nbytes;
1888 spin_unlock(&fc->lock);
1890 fuse_copy_finish(cs);
1894 static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
1895 unsigned long nr_segs, loff_t pos)
1897 struct fuse_copy_state cs;
1898 struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
1902 fuse_copy_init(&cs, fc, 0, iov, nr_segs);
1904 return fuse_dev_do_write(fc, &cs, iov_length(iov, nr_segs));
1907 static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1908 struct file *out, loff_t *ppos,
1909 size_t len, unsigned int flags)
1913 struct pipe_buffer *bufs;
1914 struct fuse_copy_state cs;
1915 struct fuse_conn *fc;
1919 fc = fuse_get_conn(out);
1923 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1930 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
1931 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
1941 struct pipe_buffer *ibuf;
1942 struct pipe_buffer *obuf;
1944 BUG_ON(nbuf >= pipe->buffers);
1945 BUG_ON(!pipe->nrbufs);
1946 ibuf = &pipe->bufs[pipe->curbuf];
1949 if (rem >= ibuf->len) {
1952 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
1955 ibuf->ops->get(pipe, ibuf);
1957 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
1959 ibuf->offset += obuf->len;
1960 ibuf->len -= obuf->len;
1967 fuse_copy_init(&cs, fc, 0, NULL, nbuf);
1971 if (flags & SPLICE_F_MOVE)
1974 ret = fuse_dev_do_write(fc, &cs, len);
1976 for (idx = 0; idx < nbuf; idx++) {
1977 struct pipe_buffer *buf = &bufs[idx];
1978 buf->ops->release(pipe, buf);
1985 static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
1987 unsigned mask = POLLOUT | POLLWRNORM;
1988 struct fuse_conn *fc = fuse_get_conn(file);
1992 poll_wait(file, &fc->waitq, wait);
1994 spin_lock(&fc->lock);
1997 else if (request_pending(fc))
1998 mask |= POLLIN | POLLRDNORM;
1999 spin_unlock(&fc->lock);
2005 * Abort all requests on the given list (pending or processing)
2007 * This function releases and reacquires fc->lock
2009 static void end_requests(struct fuse_conn *fc, struct list_head *head)
2010 __releases(fc->lock)
2011 __acquires(fc->lock)
2013 while (!list_empty(head)) {
2014 struct fuse_req *req;
2015 req = list_entry(head->next, struct fuse_req, list);
2016 req->out.h.error = -ECONNABORTED;
2017 request_end(fc, req);
2018 spin_lock(&fc->lock);
2023 * Abort requests under I/O
2025 * The requests are set to aborted and finished, and the request
2026 * waiter is woken up. This will make request_wait_answer() wait
2027 * until the request is unlocked and then return.
2029 * If the request is asynchronous, then the end function needs to be
2030 * called after waiting for the request to be unlocked (if it was
2033 static void end_io_requests(struct fuse_conn *fc)
2034 __releases(fc->lock)
2035 __acquires(fc->lock)
2037 while (!list_empty(&fc->io)) {
2038 struct fuse_req *req =
2039 list_entry(fc->io.next, struct fuse_req, list);
2040 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
2043 req->out.h.error = -ECONNABORTED;
2044 req->state = FUSE_REQ_FINISHED;
2045 list_del_init(&req->list);
2046 wake_up(&req->waitq);
2049 __fuse_get_request(req);
2050 spin_unlock(&fc->lock);
2051 wait_event(req->waitq, !req->locked);
2053 fuse_put_request(fc, req);
2054 spin_lock(&fc->lock);
2059 static void end_queued_requests(struct fuse_conn *fc)
2060 __releases(fc->lock)
2061 __acquires(fc->lock)
2063 fc->max_background = UINT_MAX;
2065 end_requests(fc, &fc->pending);
2066 end_requests(fc, &fc->processing);
2067 while (forget_pending(fc))
2068 kfree(dequeue_forget(fc, 1, NULL));
2071 static void end_polls(struct fuse_conn *fc)
2075 p = rb_first(&fc->polled_files);
2078 struct fuse_file *ff;
2079 ff = rb_entry(p, struct fuse_file, polled_node);
2080 wake_up_interruptible_all(&ff->poll_wait);
2087 * Abort all requests.
2089 * Emergency exit in case of a malicious or accidental deadlock, or
2090 * just a hung filesystem.
2092 * The same effect is usually achievable through killing the
2093 * filesystem daemon and all users of the filesystem. The exception
2094 * is the combination of an asynchronous request and the tricky
2095 * deadlock (see Documentation/filesystems/fuse.txt).
2097 * During the aborting, progression of requests from the pending and
2098 * processing lists onto the io list, and progression of new requests
2099 * onto the pending list is prevented by req->connected being false.
2101 * Progression of requests under I/O to the processing list is
2102 * prevented by the req->aborted flag being true for these requests.
2103 * For this reason requests on the io list must be aborted first.
2105 void fuse_abort_conn(struct fuse_conn *fc)
2107 spin_lock(&fc->lock);
2108 if (fc->connected) {
2111 fc->initialized = 1;
2112 end_io_requests(fc);
2113 end_queued_requests(fc);
2115 wake_up_all(&fc->waitq);
2116 wake_up_all(&fc->blocked_waitq);
2117 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
2119 spin_unlock(&fc->lock);
2121 EXPORT_SYMBOL_GPL(fuse_abort_conn);
2123 int fuse_dev_release(struct inode *inode, struct file *file)
2125 struct fuse_conn *fc = fuse_get_conn(file);
2127 spin_lock(&fc->lock);
2130 fc->initialized = 1;
2131 end_queued_requests(fc);
2133 wake_up_all(&fc->blocked_waitq);
2134 spin_unlock(&fc->lock);
2140 EXPORT_SYMBOL_GPL(fuse_dev_release);
2142 static int fuse_dev_fasync(int fd, struct file *file, int on)
2144 struct fuse_conn *fc = fuse_get_conn(file);
2148 /* No locking - fasync_helper does its own locking */
2149 return fasync_helper(fd, file, on, &fc->fasync);
2152 const struct file_operations fuse_dev_operations = {
2153 .owner = THIS_MODULE,
2154 .llseek = no_llseek,
2155 .read = do_sync_read,
2156 .aio_read = fuse_dev_read,
2157 .splice_read = fuse_dev_splice_read,
2158 .write = do_sync_write,
2159 .aio_write = fuse_dev_write,
2160 .splice_write = fuse_dev_splice_write,
2161 .poll = fuse_dev_poll,
2162 .release = fuse_dev_release,
2163 .fasync = fuse_dev_fasync,
2165 EXPORT_SYMBOL_GPL(fuse_dev_operations);
2167 static struct miscdevice fuse_miscdevice = {
2168 .minor = FUSE_MINOR,
2170 .fops = &fuse_dev_operations,
2173 int __init fuse_dev_init(void)
2176 fuse_req_cachep = kmem_cache_create("fuse_request",
2177 sizeof(struct fuse_req),
2179 if (!fuse_req_cachep)
2182 err = misc_register(&fuse_miscdevice);
2184 goto out_cache_clean;
2189 kmem_cache_destroy(fuse_req_cachep);
2194 void fuse_dev_cleanup(void)
2196 misc_deregister(&fuse_miscdevice);
2197 kmem_cache_destroy(fuse_req_cachep);