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>
24 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
25 MODULE_ALIAS("devname:fuse");
27 static struct kmem_cache *fuse_req_cachep;
29 static struct fuse_conn *fuse_get_conn(struct file *file)
32 * Lockless access is OK, because file->private data is set
33 * once during mount and is valid until the file is released.
35 return file->private_data;
38 static void fuse_request_init(struct fuse_req *req, struct page **pages,
39 struct fuse_page_desc *page_descs,
42 memset(req, 0, sizeof(*req));
43 memset(pages, 0, sizeof(*pages) * npages);
44 memset(page_descs, 0, sizeof(*page_descs) * npages);
45 INIT_LIST_HEAD(&req->list);
46 INIT_LIST_HEAD(&req->intr_entry);
47 init_waitqueue_head(&req->waitq);
48 atomic_set(&req->count, 1);
50 req->page_descs = page_descs;
51 req->max_pages = npages;
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() */
172 req = fuse_request_alloc(npages);
176 wake_up(&fc->blocked_waitq);
180 fuse_req_init_context(req);
182 req->background = for_background;
186 atomic_dec(&fc->num_waiting);
190 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
192 return __fuse_get_req(fc, npages, false);
194 EXPORT_SYMBOL_GPL(fuse_get_req);
196 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
199 return __fuse_get_req(fc, npages, true);
201 EXPORT_SYMBOL_GPL(fuse_get_req_for_background);
204 * Return request in fuse_file->reserved_req. However that may
205 * currently be in use. If that is the case, wait for it to become
208 static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
211 struct fuse_req *req = NULL;
212 struct fuse_file *ff = file->private_data;
215 wait_event(fc->reserved_req_waitq, ff->reserved_req);
216 spin_lock(&fc->lock);
217 if (ff->reserved_req) {
218 req = ff->reserved_req;
219 ff->reserved_req = NULL;
220 req->stolen_file = get_file(file);
222 spin_unlock(&fc->lock);
229 * Put stolen request back into fuse_file->reserved_req
231 static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
233 struct file *file = req->stolen_file;
234 struct fuse_file *ff = file->private_data;
236 spin_lock(&fc->lock);
237 fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
238 BUG_ON(ff->reserved_req);
239 ff->reserved_req = req;
240 wake_up_all(&fc->reserved_req_waitq);
241 spin_unlock(&fc->lock);
246 * Gets a requests for a file operation, always succeeds
248 * This is used for sending the FLUSH request, which must get to
249 * userspace, due to POSIX locks which may need to be unlocked.
251 * If allocation fails due to OOM, use the reserved request in
254 * This is very unlikely to deadlock accidentally, since the
255 * filesystem should not have it's own file open. If deadlock is
256 * intentional, it can still be broken by "aborting" the filesystem.
258 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
261 struct fuse_req *req;
263 atomic_inc(&fc->num_waiting);
264 wait_event(fc->blocked_waitq, fc->initialized);
265 /* Matches smp_wmb() in fuse_set_initialized() */
267 req = fuse_request_alloc(0);
269 req = get_reserved_req(fc, file);
271 fuse_req_init_context(req);
277 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
279 if (atomic_dec_and_test(&req->count)) {
280 if (unlikely(req->background)) {
282 * We get here in the unlikely case that a background
283 * request was allocated but not sent
285 spin_lock(&fc->lock);
287 wake_up(&fc->blocked_waitq);
288 spin_unlock(&fc->lock);
292 atomic_dec(&fc->num_waiting);
294 if (req->stolen_file)
295 put_reserved_req(fc, req);
297 fuse_request_free(req);
300 EXPORT_SYMBOL_GPL(fuse_put_request);
302 static unsigned len_args(unsigned numargs, struct fuse_arg *args)
307 for (i = 0; i < numargs; i++)
308 nbytes += args[i].size;
313 static u64 fuse_get_unique(struct fuse_conn *fc)
316 /* zero is special */
323 static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
325 req->in.h.len = sizeof(struct fuse_in_header) +
326 len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
327 list_add_tail(&req->list, &fc->pending);
328 req->state = FUSE_REQ_PENDING;
331 atomic_inc(&fc->num_waiting);
334 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
337 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
338 u64 nodeid, u64 nlookup)
340 forget->forget_one.nodeid = nodeid;
341 forget->forget_one.nlookup = nlookup;
343 spin_lock(&fc->lock);
345 fc->forget_list_tail->next = forget;
346 fc->forget_list_tail = forget;
348 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
352 spin_unlock(&fc->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;
361 req = list_entry(fc->bg_queue.next, struct fuse_req, list);
362 list_del(&req->list);
363 fc->active_background++;
364 req->in.h.unique = fuse_get_unique(fc);
365 queue_request(fc, req);
370 * This function is called when a request is finished. Either a reply
371 * has arrived or it was aborted (and not yet sent) or some error
372 * occurred during communication with userspace, or the device file
373 * was closed. The requester thread is woken up (if still waiting),
374 * the 'end' callback is called if given, else the reference to the
375 * request is released
377 * Called with fc->lock, unlocks it
379 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
382 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
384 list_del(&req->list);
385 list_del(&req->intr_entry);
386 req->state = FUSE_REQ_FINISHED;
387 if (req->background) {
390 if (fc->num_background == fc->max_background)
393 /* Wake up next waiter, if any */
394 if (!fc->blocked && waitqueue_active(&fc->blocked_waitq))
395 wake_up(&fc->blocked_waitq);
397 if (fc->num_background == fc->congestion_threshold &&
398 fc->connected && fc->bdi_initialized) {
399 clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);
400 clear_bdi_congested(&fc->bdi, BLK_RW_ASYNC);
402 fc->num_background--;
403 fc->active_background--;
406 spin_unlock(&fc->lock);
407 wake_up(&req->waitq);
410 fuse_put_request(fc, req);
413 static void wait_answer_interruptible(struct fuse_conn *fc,
414 struct fuse_req *req)
418 if (signal_pending(current))
421 spin_unlock(&fc->lock);
422 wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
423 spin_lock(&fc->lock);
426 static void queue_interrupt(struct fuse_conn *fc, struct fuse_req *req)
428 list_add_tail(&req->intr_entry, &fc->interrupts);
430 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
433 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
437 if (!fc->no_interrupt) {
438 /* Any signal may interrupt this */
439 wait_answer_interruptible(fc, req);
443 if (req->state == FUSE_REQ_FINISHED)
446 req->interrupted = 1;
447 if (req->state == FUSE_REQ_SENT)
448 queue_interrupt(fc, req);
454 /* Only fatal signals may interrupt this */
456 wait_answer_interruptible(fc, req);
457 restore_sigs(&oldset);
461 if (req->state == FUSE_REQ_FINISHED)
464 /* Request is not yet in userspace, bail out */
465 if (req->state == FUSE_REQ_PENDING) {
466 list_del(&req->list);
467 __fuse_put_request(req);
468 req->out.h.error = -EINTR;
474 * Either request is already in userspace, or it was forced.
477 spin_unlock(&fc->lock);
478 wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
479 spin_lock(&fc->lock);
485 BUG_ON(req->state != FUSE_REQ_FINISHED);
487 /* This is uninterruptible sleep, because data is
488 being copied to/from the buffers of req. During
489 locked state, there mustn't be any filesystem
490 operation (e.g. page fault), since that could lead
492 spin_unlock(&fc->lock);
493 wait_event(req->waitq, !req->locked);
494 spin_lock(&fc->lock);
498 static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
500 BUG_ON(req->background);
501 spin_lock(&fc->lock);
503 req->out.h.error = -ENOTCONN;
504 else if (fc->conn_error)
505 req->out.h.error = -ECONNREFUSED;
507 req->in.h.unique = fuse_get_unique(fc);
508 queue_request(fc, req);
509 /* acquire extra reference, since request is still needed
510 after request_end() */
511 __fuse_get_request(req);
513 request_wait_answer(fc, req);
515 spin_unlock(&fc->lock);
518 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
521 __fuse_request_send(fc, req);
523 EXPORT_SYMBOL_GPL(fuse_request_send);
525 static void fuse_adjust_compat(struct fuse_conn *fc, struct fuse_args *args)
527 if (fc->minor < 4 && args->in.h.opcode == FUSE_STATFS)
528 args->out.args[0].size = FUSE_COMPAT_STATFS_SIZE;
531 switch (args->in.h.opcode) {
538 args->out.args[0].size = FUSE_COMPAT_ENTRY_OUT_SIZE;
542 args->out.args[0].size = FUSE_COMPAT_ATTR_OUT_SIZE;
546 if (fc->minor < 12) {
547 switch (args->in.h.opcode) {
549 args->in.args[0].size = sizeof(struct fuse_open_in);
552 args->in.args[0].size = FUSE_COMPAT_MKNOD_IN_SIZE;
558 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args)
560 struct fuse_req *req;
563 req = fuse_get_req(fc, 0);
567 /* Needs to be done after fuse_get_req() so that fc->minor is valid */
568 fuse_adjust_compat(fc, args);
570 req->in.h.opcode = args->in.h.opcode;
571 req->in.h.nodeid = args->in.h.nodeid;
572 req->in.numargs = args->in.numargs;
573 memcpy(req->in.args, args->in.args,
574 args->in.numargs * sizeof(struct fuse_in_arg));
575 req->out.argvar = args->out.argvar;
576 req->out.numargs = args->out.numargs;
577 memcpy(req->out.args, args->out.args,
578 args->out.numargs * sizeof(struct fuse_arg));
579 fuse_request_send(fc, req);
580 ret = req->out.h.error;
581 if (!ret && args->out.argvar) {
582 BUG_ON(args->out.numargs != 1);
583 ret = req->out.args[0].size;
585 fuse_put_request(fc, req);
590 static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
591 struct fuse_req *req)
593 BUG_ON(!req->background);
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 static void fuse_request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
608 spin_lock(&fc->lock);
610 fuse_request_send_nowait_locked(fc, req);
611 spin_unlock(&fc->lock);
613 req->out.h.error = -ENOTCONN;
614 request_end(fc, req);
618 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req)
621 fuse_request_send_nowait(fc, req);
623 EXPORT_SYMBOL_GPL(fuse_request_send_background);
625 static int fuse_request_send_notify_reply(struct fuse_conn *fc,
626 struct fuse_req *req, u64 unique)
631 req->in.h.unique = unique;
632 spin_lock(&fc->lock);
634 queue_request(fc, req);
637 spin_unlock(&fc->lock);
643 * Called under fc->lock
645 * fc->connected must have been checked previously
647 void fuse_request_send_background_locked(struct fuse_conn *fc,
648 struct fuse_req *req)
651 fuse_request_send_nowait_locked(fc, req);
654 void fuse_force_forget(struct file *file, u64 nodeid)
656 struct inode *inode = file_inode(file);
657 struct fuse_conn *fc = get_fuse_conn(inode);
658 struct fuse_req *req;
659 struct fuse_forget_in inarg;
661 memset(&inarg, 0, sizeof(inarg));
663 req = fuse_get_req_nofail_nopages(fc, file);
664 req->in.h.opcode = FUSE_FORGET;
665 req->in.h.nodeid = nodeid;
667 req->in.args[0].size = sizeof(inarg);
668 req->in.args[0].value = &inarg;
670 __fuse_request_send(fc, req);
672 fuse_put_request(fc, req);
676 * Lock the request. Up to the next unlock_request() there mustn't be
677 * anything that could cause a page-fault. If the request was already
680 static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
684 spin_lock(&fc->lock);
689 spin_unlock(&fc->lock);
695 * Unlock request. If it was aborted during being locked, the
696 * requester thread is currently waiting for it to be unlocked, so
699 static void unlock_request(struct fuse_conn *fc, struct fuse_req *req)
702 spin_lock(&fc->lock);
705 wake_up(&req->waitq);
706 spin_unlock(&fc->lock);
710 struct fuse_copy_state {
711 struct fuse_conn *fc;
713 struct fuse_req *req;
714 const struct iovec *iov;
715 struct pipe_buffer *pipebufs;
716 struct pipe_buffer *currbuf;
717 struct pipe_inode_info *pipe;
718 unsigned long nr_segs;
719 unsigned long seglen;
724 unsigned move_pages:1;
727 static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
729 const struct iovec *iov, unsigned long nr_segs)
731 memset(cs, 0, sizeof(*cs));
735 cs->nr_segs = nr_segs;
738 /* Unmap and put previous page of userspace buffer */
739 static void fuse_copy_finish(struct fuse_copy_state *cs)
742 struct pipe_buffer *buf = cs->currbuf;
745 buf->len = PAGE_SIZE - cs->len;
749 flush_dcache_page(cs->pg);
750 set_page_dirty_lock(cs->pg);
758 * Get another pagefull of userspace buffer, and map it to kernel
759 * address space, and lock request
761 static int fuse_copy_fill(struct fuse_copy_state *cs)
766 unlock_request(cs->fc, cs->req);
767 fuse_copy_finish(cs);
769 struct pipe_buffer *buf = cs->pipebufs;
772 err = buf->ops->confirm(cs->pipe, buf);
776 BUG_ON(!cs->nr_segs);
779 cs->offset = buf->offset;
784 if (cs->nr_segs == cs->pipe->buffers)
787 page = alloc_page(GFP_HIGHUSER);
804 BUG_ON(!cs->nr_segs);
805 cs->seglen = cs->iov[0].iov_len;
806 cs->addr = (unsigned long) cs->iov[0].iov_base;
810 err = get_user_pages_fast(cs->addr, 1, cs->write, &page);
815 cs->offset = cs->addr % PAGE_SIZE;
816 cs->len = min(PAGE_SIZE - cs->offset, cs->seglen);
817 cs->seglen -= cs->len;
821 return lock_request(cs->fc, cs->req);
824 /* Do as much copy to/from userspace buffer as we can */
825 static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
827 unsigned ncpy = min(*size, cs->len);
829 void *pgaddr = kmap_atomic(cs->pg);
830 void *buf = pgaddr + cs->offset;
833 memcpy(buf, *val, ncpy);
835 memcpy(*val, buf, ncpy);
837 kunmap_atomic(pgaddr);
846 static int fuse_check_page(struct page *page)
848 if (page_mapcount(page) ||
849 page->mapping != NULL ||
850 page_count(page) != 1 ||
851 (page->flags & PAGE_FLAGS_CHECK_AT_PREP &
858 printk(KERN_WARNING "fuse: trying to steal weird page\n");
859 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);
865 static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
868 struct page *oldpage = *pagep;
869 struct page *newpage;
870 struct pipe_buffer *buf = cs->pipebufs;
872 unlock_request(cs->fc, cs->req);
873 fuse_copy_finish(cs);
875 err = buf->ops->confirm(cs->pipe, buf);
879 BUG_ON(!cs->nr_segs);
885 if (cs->len != PAGE_SIZE)
888 if (buf->ops->steal(cs->pipe, buf) != 0)
893 if (WARN_ON(!PageUptodate(newpage)))
896 ClearPageMappedToDisk(newpage);
898 if (fuse_check_page(newpage) != 0)
899 goto out_fallback_unlock;
902 * This is a new and locked page, it shouldn't be mapped or
903 * have any special flags on it
905 if (WARN_ON(page_mapped(oldpage)))
906 goto out_fallback_unlock;
907 if (WARN_ON(page_has_private(oldpage)))
908 goto out_fallback_unlock;
909 if (WARN_ON(PageDirty(oldpage) || PageWriteback(oldpage)))
910 goto out_fallback_unlock;
911 if (WARN_ON(PageMlocked(oldpage)))
912 goto out_fallback_unlock;
914 err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL);
916 unlock_page(newpage);
920 page_cache_get(newpage);
922 if (!(buf->flags & PIPE_BUF_FLAG_LRU))
923 lru_cache_add_file(newpage);
926 spin_lock(&cs->fc->lock);
927 if (cs->req->aborted)
931 spin_unlock(&cs->fc->lock);
934 unlock_page(newpage);
935 page_cache_release(newpage);
939 unlock_page(oldpage);
940 page_cache_release(oldpage);
946 unlock_page(newpage);
949 cs->offset = buf->offset;
951 err = lock_request(cs->fc, cs->req);
958 static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
959 unsigned offset, unsigned count)
961 struct pipe_buffer *buf;
963 if (cs->nr_segs == cs->pipe->buffers)
966 unlock_request(cs->fc, cs->req);
967 fuse_copy_finish(cs);
970 page_cache_get(page);
972 buf->offset = offset;
983 * Copy a page in the request to/from the userspace buffer. Must be
986 static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
987 unsigned offset, unsigned count, int zeroing)
990 struct page *page = *pagep;
992 if (page && zeroing && count < PAGE_SIZE)
993 clear_highpage(page);
996 if (cs->write && cs->pipebufs && page) {
997 return fuse_ref_page(cs, page, offset, count);
998 } else if (!cs->len) {
999 if (cs->move_pages && page &&
1000 offset == 0 && count == PAGE_SIZE) {
1001 err = fuse_try_move_page(cs, pagep);
1005 err = fuse_copy_fill(cs);
1011 void *mapaddr = kmap_atomic(page);
1012 void *buf = mapaddr + offset;
1013 offset += fuse_copy_do(cs, &buf, &count);
1014 kunmap_atomic(mapaddr);
1016 offset += fuse_copy_do(cs, NULL, &count);
1018 if (page && !cs->write)
1019 flush_dcache_page(page);
1023 /* Copy pages in the request to/from userspace buffer */
1024 static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
1028 struct fuse_req *req = cs->req;
1030 for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
1032 unsigned offset = req->page_descs[i].offset;
1033 unsigned count = min(nbytes, req->page_descs[i].length);
1035 err = fuse_copy_page(cs, &req->pages[i], offset, count,
1045 /* Copy a single argument in the request to/from userspace buffer */
1046 static int fuse_copy_one(struct fuse_copy_state *cs, void *val, unsigned size)
1050 int err = fuse_copy_fill(cs);
1054 fuse_copy_do(cs, &val, &size);
1059 /* Copy request arguments to/from userspace buffer */
1060 static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
1061 unsigned argpages, struct fuse_arg *args,
1067 for (i = 0; !err && i < numargs; i++) {
1068 struct fuse_arg *arg = &args[i];
1069 if (i == numargs - 1 && argpages)
1070 err = fuse_copy_pages(cs, arg->size, zeroing);
1072 err = fuse_copy_one(cs, arg->value, arg->size);
1077 static int forget_pending(struct fuse_conn *fc)
1079 return fc->forget_list_head.next != NULL;
1082 static int request_pending(struct fuse_conn *fc)
1084 return !list_empty(&fc->pending) || !list_empty(&fc->interrupts) ||
1088 /* Wait until a request is available on the pending list */
1089 static void request_wait(struct fuse_conn *fc)
1090 __releases(fc->lock)
1091 __acquires(fc->lock)
1093 DECLARE_WAITQUEUE(wait, current);
1095 add_wait_queue_exclusive(&fc->waitq, &wait);
1096 while (fc->connected && !request_pending(fc)) {
1097 set_current_state(TASK_INTERRUPTIBLE);
1098 if (signal_pending(current))
1101 spin_unlock(&fc->lock);
1103 spin_lock(&fc->lock);
1105 set_current_state(TASK_RUNNING);
1106 remove_wait_queue(&fc->waitq, &wait);
1110 * Transfer an interrupt request to userspace
1112 * Unlike other requests this is assembled on demand, without a need
1113 * to allocate a separate fuse_req structure.
1115 * Called with fc->lock held, releases it
1117 static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_copy_state *cs,
1118 size_t nbytes, struct fuse_req *req)
1119 __releases(fc->lock)
1121 struct fuse_in_header ih;
1122 struct fuse_interrupt_in arg;
1123 unsigned reqsize = sizeof(ih) + sizeof(arg);
1126 list_del_init(&req->intr_entry);
1127 req->intr_unique = fuse_get_unique(fc);
1128 memset(&ih, 0, sizeof(ih));
1129 memset(&arg, 0, sizeof(arg));
1131 ih.opcode = FUSE_INTERRUPT;
1132 ih.unique = req->intr_unique;
1133 arg.unique = req->in.h.unique;
1135 spin_unlock(&fc->lock);
1136 if (nbytes < reqsize)
1139 err = fuse_copy_one(cs, &ih, sizeof(ih));
1141 err = fuse_copy_one(cs, &arg, sizeof(arg));
1142 fuse_copy_finish(cs);
1144 return err ? err : reqsize;
1147 static struct fuse_forget_link *dequeue_forget(struct fuse_conn *fc,
1151 struct fuse_forget_link *head = fc->forget_list_head.next;
1152 struct fuse_forget_link **newhead = &head;
1155 for (count = 0; *newhead != NULL && count < max; count++)
1156 newhead = &(*newhead)->next;
1158 fc->forget_list_head.next = *newhead;
1160 if (fc->forget_list_head.next == NULL)
1161 fc->forget_list_tail = &fc->forget_list_head;
1169 static int fuse_read_single_forget(struct fuse_conn *fc,
1170 struct fuse_copy_state *cs,
1172 __releases(fc->lock)
1175 struct fuse_forget_link *forget = dequeue_forget(fc, 1, NULL);
1176 struct fuse_forget_in arg = {
1177 .nlookup = forget->forget_one.nlookup,
1179 struct fuse_in_header ih = {
1180 .opcode = FUSE_FORGET,
1181 .nodeid = forget->forget_one.nodeid,
1182 .unique = fuse_get_unique(fc),
1183 .len = sizeof(ih) + sizeof(arg),
1186 spin_unlock(&fc->lock);
1188 if (nbytes < ih.len)
1191 err = fuse_copy_one(cs, &ih, sizeof(ih));
1193 err = fuse_copy_one(cs, &arg, sizeof(arg));
1194 fuse_copy_finish(cs);
1202 static int fuse_read_batch_forget(struct fuse_conn *fc,
1203 struct fuse_copy_state *cs, size_t nbytes)
1204 __releases(fc->lock)
1207 unsigned max_forgets;
1209 struct fuse_forget_link *head;
1210 struct fuse_batch_forget_in arg = { .count = 0 };
1211 struct fuse_in_header ih = {
1212 .opcode = FUSE_BATCH_FORGET,
1213 .unique = fuse_get_unique(fc),
1214 .len = sizeof(ih) + sizeof(arg),
1217 if (nbytes < ih.len) {
1218 spin_unlock(&fc->lock);
1222 max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
1223 head = dequeue_forget(fc, max_forgets, &count);
1224 spin_unlock(&fc->lock);
1227 ih.len += count * sizeof(struct fuse_forget_one);
1228 err = fuse_copy_one(cs, &ih, sizeof(ih));
1230 err = fuse_copy_one(cs, &arg, sizeof(arg));
1233 struct fuse_forget_link *forget = head;
1236 err = fuse_copy_one(cs, &forget->forget_one,
1237 sizeof(forget->forget_one));
1239 head = forget->next;
1243 fuse_copy_finish(cs);
1251 static int fuse_read_forget(struct fuse_conn *fc, struct fuse_copy_state *cs,
1253 __releases(fc->lock)
1255 if (fc->minor < 16 || fc->forget_list_head.next->next == NULL)
1256 return fuse_read_single_forget(fc, cs, nbytes);
1258 return fuse_read_batch_forget(fc, cs, nbytes);
1262 * Read a single request into the userspace filesystem's buffer. This
1263 * function waits until a request is available, then removes it from
1264 * the pending list and copies request data to userspace buffer. If
1265 * no reply is needed (FORGET) or request has been aborted or there
1266 * was an error during the copying then it's finished by calling
1267 * request_end(). Otherwise add it to the processing list, and set
1270 static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
1271 struct fuse_copy_state *cs, size_t nbytes)
1274 struct fuse_req *req;
1279 spin_lock(&fc->lock);
1281 if ((file->f_flags & O_NONBLOCK) && fc->connected &&
1282 !request_pending(fc))
1290 if (!request_pending(fc))
1293 if (!list_empty(&fc->interrupts)) {
1294 req = list_entry(fc->interrupts.next, struct fuse_req,
1296 return fuse_read_interrupt(fc, cs, nbytes, req);
1299 if (forget_pending(fc)) {
1300 if (list_empty(&fc->pending) || fc->forget_batch-- > 0)
1301 return fuse_read_forget(fc, cs, nbytes);
1303 if (fc->forget_batch <= -8)
1304 fc->forget_batch = 16;
1307 req = list_entry(fc->pending.next, struct fuse_req, list);
1308 req->state = FUSE_REQ_READING;
1309 list_move(&req->list, &fc->io);
1312 reqsize = in->h.len;
1313 /* If request is too large, reply with an error and restart the read */
1314 if (nbytes < reqsize) {
1315 req->out.h.error = -EIO;
1316 /* SETXATTR is special, since it may contain too large data */
1317 if (in->h.opcode == FUSE_SETXATTR)
1318 req->out.h.error = -E2BIG;
1319 request_end(fc, req);
1322 spin_unlock(&fc->lock);
1324 err = fuse_copy_one(cs, &in->h, sizeof(in->h));
1326 err = fuse_copy_args(cs, in->numargs, in->argpages,
1327 (struct fuse_arg *) in->args, 0);
1328 fuse_copy_finish(cs);
1329 spin_lock(&fc->lock);
1332 request_end(fc, req);
1336 req->out.h.error = -EIO;
1337 request_end(fc, req);
1341 request_end(fc, req);
1343 req->state = FUSE_REQ_SENT;
1344 list_move_tail(&req->list, &fc->processing);
1345 if (req->interrupted)
1346 queue_interrupt(fc, req);
1347 spin_unlock(&fc->lock);
1352 spin_unlock(&fc->lock);
1356 static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
1357 unsigned long nr_segs, loff_t pos)
1359 struct fuse_copy_state cs;
1360 struct file *file = iocb->ki_filp;
1361 struct fuse_conn *fc = fuse_get_conn(file);
1365 fuse_copy_init(&cs, fc, 1, iov, nr_segs);
1367 return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
1370 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
1371 struct pipe_inode_info *pipe,
1372 size_t len, unsigned int flags)
1377 struct pipe_buffer *bufs;
1378 struct fuse_copy_state cs;
1379 struct fuse_conn *fc = fuse_get_conn(in);
1383 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1387 fuse_copy_init(&cs, fc, 1, NULL, 0);
1390 ret = fuse_dev_do_read(fc, in, &cs, len);
1397 if (!pipe->readers) {
1398 send_sig(SIGPIPE, current, 0);
1404 if (pipe->nrbufs + cs.nr_segs > pipe->buffers) {
1409 while (page_nr < cs.nr_segs) {
1410 int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
1411 struct pipe_buffer *buf = pipe->bufs + newbuf;
1413 buf->page = bufs[page_nr].page;
1414 buf->offset = bufs[page_nr].offset;
1415 buf->len = bufs[page_nr].len;
1417 * Need to be careful about this. Having buf->ops in module
1418 * code can Oops if the buffer persists after module unload.
1420 buf->ops = &nosteal_pipe_buf_ops;
1435 if (waitqueue_active(&pipe->wait))
1436 wake_up_interruptible(&pipe->wait);
1437 kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
1441 for (; page_nr < cs.nr_segs; page_nr++)
1442 page_cache_release(bufs[page_nr].page);
1448 static int fuse_notify_poll(struct fuse_conn *fc, unsigned int size,
1449 struct fuse_copy_state *cs)
1451 struct fuse_notify_poll_wakeup_out outarg;
1454 if (size != sizeof(outarg))
1457 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1461 fuse_copy_finish(cs);
1462 return fuse_notify_poll_wakeup(fc, &outarg);
1465 fuse_copy_finish(cs);
1469 static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
1470 struct fuse_copy_state *cs)
1472 struct fuse_notify_inval_inode_out outarg;
1475 if (size != sizeof(outarg))
1478 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1481 fuse_copy_finish(cs);
1483 down_read(&fc->killsb);
1486 err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
1487 outarg.off, outarg.len);
1489 up_read(&fc->killsb);
1493 fuse_copy_finish(cs);
1497 static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
1498 struct fuse_copy_state *cs)
1500 struct fuse_notify_inval_entry_out outarg;
1505 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1510 if (size < sizeof(outarg))
1513 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1517 err = -ENAMETOOLONG;
1518 if (outarg.namelen > FUSE_NAME_MAX)
1522 if (size != sizeof(outarg) + outarg.namelen + 1)
1526 name.len = outarg.namelen;
1527 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1530 fuse_copy_finish(cs);
1531 buf[outarg.namelen] = 0;
1532 name.hash = full_name_hash(name.name, name.len);
1534 down_read(&fc->killsb);
1537 err = fuse_reverse_inval_entry(fc->sb, outarg.parent, 0, &name);
1538 up_read(&fc->killsb);
1544 fuse_copy_finish(cs);
1548 static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
1549 struct fuse_copy_state *cs)
1551 struct fuse_notify_delete_out outarg;
1556 buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
1561 if (size < sizeof(outarg))
1564 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1568 err = -ENAMETOOLONG;
1569 if (outarg.namelen > FUSE_NAME_MAX)
1573 if (size != sizeof(outarg) + outarg.namelen + 1)
1577 name.len = outarg.namelen;
1578 err = fuse_copy_one(cs, buf, outarg.namelen + 1);
1581 fuse_copy_finish(cs);
1582 buf[outarg.namelen] = 0;
1583 name.hash = full_name_hash(name.name, name.len);
1585 down_read(&fc->killsb);
1588 err = fuse_reverse_inval_entry(fc->sb, outarg.parent,
1589 outarg.child, &name);
1590 up_read(&fc->killsb);
1596 fuse_copy_finish(cs);
1600 static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
1601 struct fuse_copy_state *cs)
1603 struct fuse_notify_store_out outarg;
1604 struct inode *inode;
1605 struct address_space *mapping;
1609 unsigned int offset;
1615 if (size < sizeof(outarg))
1618 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1623 if (size - sizeof(outarg) != outarg.size)
1626 nodeid = outarg.nodeid;
1628 down_read(&fc->killsb);
1634 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1638 mapping = inode->i_mapping;
1639 index = outarg.offset >> PAGE_CACHE_SHIFT;
1640 offset = outarg.offset & ~PAGE_CACHE_MASK;
1641 file_size = i_size_read(inode);
1642 end = outarg.offset + outarg.size;
1643 if (end > file_size) {
1645 fuse_write_update_size(inode, file_size);
1651 unsigned int this_num;
1654 page = find_or_create_page(mapping, index,
1655 mapping_gfp_mask(mapping));
1659 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1660 err = fuse_copy_page(cs, &page, offset, this_num, 0);
1661 if (!err && offset == 0 &&
1662 (this_num == PAGE_CACHE_SIZE || file_size == end))
1663 SetPageUptodate(page);
1665 page_cache_release(page);
1680 up_read(&fc->killsb);
1682 fuse_copy_finish(cs);
1686 static void fuse_retrieve_end(struct fuse_conn *fc, struct fuse_req *req)
1688 release_pages(req->pages, req->num_pages, false);
1691 static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
1692 struct fuse_notify_retrieve_out *outarg)
1695 struct address_space *mapping = inode->i_mapping;
1696 struct fuse_req *req;
1700 unsigned int offset;
1701 size_t total_len = 0;
1704 offset = outarg->offset & ~PAGE_CACHE_MASK;
1705 file_size = i_size_read(inode);
1708 if (outarg->offset > file_size)
1710 else if (outarg->offset + num > file_size)
1711 num = file_size - outarg->offset;
1713 num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
1714 num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
1716 req = fuse_get_req(fc, num_pages);
1718 return PTR_ERR(req);
1720 req->in.h.opcode = FUSE_NOTIFY_REPLY;
1721 req->in.h.nodeid = outarg->nodeid;
1722 req->in.numargs = 2;
1723 req->in.argpages = 1;
1724 req->page_descs[0].offset = offset;
1725 req->end = fuse_retrieve_end;
1727 index = outarg->offset >> PAGE_CACHE_SHIFT;
1729 while (num && req->num_pages < num_pages) {
1731 unsigned int this_num;
1733 page = find_get_page(mapping, index);
1737 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
1738 req->pages[req->num_pages] = page;
1739 req->page_descs[req->num_pages].length = this_num;
1744 total_len += this_num;
1747 req->misc.retrieve_in.offset = outarg->offset;
1748 req->misc.retrieve_in.size = total_len;
1749 req->in.args[0].size = sizeof(req->misc.retrieve_in);
1750 req->in.args[0].value = &req->misc.retrieve_in;
1751 req->in.args[1].size = total_len;
1753 err = fuse_request_send_notify_reply(fc, req, outarg->notify_unique);
1755 fuse_retrieve_end(fc, req);
1760 static int fuse_notify_retrieve(struct fuse_conn *fc, unsigned int size,
1761 struct fuse_copy_state *cs)
1763 struct fuse_notify_retrieve_out outarg;
1764 struct inode *inode;
1768 if (size != sizeof(outarg))
1771 err = fuse_copy_one(cs, &outarg, sizeof(outarg));
1775 fuse_copy_finish(cs);
1777 down_read(&fc->killsb);
1780 u64 nodeid = outarg.nodeid;
1782 inode = ilookup5(fc->sb, nodeid, fuse_inode_eq, &nodeid);
1784 err = fuse_retrieve(fc, inode, &outarg);
1788 up_read(&fc->killsb);
1793 fuse_copy_finish(cs);
1797 static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
1798 unsigned int size, struct fuse_copy_state *cs)
1800 /* Don't try to move pages (yet) */
1804 case FUSE_NOTIFY_POLL:
1805 return fuse_notify_poll(fc, size, cs);
1807 case FUSE_NOTIFY_INVAL_INODE:
1808 return fuse_notify_inval_inode(fc, size, cs);
1810 case FUSE_NOTIFY_INVAL_ENTRY:
1811 return fuse_notify_inval_entry(fc, size, cs);
1813 case FUSE_NOTIFY_STORE:
1814 return fuse_notify_store(fc, size, cs);
1816 case FUSE_NOTIFY_RETRIEVE:
1817 return fuse_notify_retrieve(fc, size, cs);
1819 case FUSE_NOTIFY_DELETE:
1820 return fuse_notify_delete(fc, size, cs);
1823 fuse_copy_finish(cs);
1828 /* Look up request on processing list by unique ID */
1829 static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
1831 struct fuse_req *req;
1833 list_for_each_entry(req, &fc->processing, list) {
1834 if (req->in.h.unique == unique || req->intr_unique == unique)
1840 static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
1843 unsigned reqsize = sizeof(struct fuse_out_header);
1846 return nbytes != reqsize ? -EINVAL : 0;
1848 reqsize += len_args(out->numargs, out->args);
1850 if (reqsize < nbytes || (reqsize > nbytes && !out->argvar))
1852 else if (reqsize > nbytes) {
1853 struct fuse_arg *lastarg = &out->args[out->numargs-1];
1854 unsigned diffsize = reqsize - nbytes;
1855 if (diffsize > lastarg->size)
1857 lastarg->size -= diffsize;
1859 return fuse_copy_args(cs, out->numargs, out->argpages, out->args,
1864 * Write a single reply to a request. First the header is copied from
1865 * the write buffer. The request is then searched on the processing
1866 * list by the unique ID found in the header. If found, then remove
1867 * it from the list and copy the rest of the buffer to the request.
1868 * The request is finished by calling request_end()
1870 static ssize_t fuse_dev_do_write(struct fuse_conn *fc,
1871 struct fuse_copy_state *cs, size_t nbytes)
1874 struct fuse_req *req;
1875 struct fuse_out_header oh;
1877 if (nbytes < sizeof(struct fuse_out_header))
1880 err = fuse_copy_one(cs, &oh, sizeof(oh));
1885 if (oh.len != nbytes)
1889 * Zero oh.unique indicates unsolicited notification message
1890 * and error contains notification code.
1893 err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), cs);
1894 return err ? err : nbytes;
1898 if (oh.error <= -1000 || oh.error > 0)
1901 spin_lock(&fc->lock);
1906 req = request_find(fc, oh.unique);
1911 spin_unlock(&fc->lock);
1912 fuse_copy_finish(cs);
1913 spin_lock(&fc->lock);
1914 request_end(fc, req);
1917 /* Is it an interrupt reply? */
1918 if (req->intr_unique == oh.unique) {
1920 if (nbytes != sizeof(struct fuse_out_header))
1923 if (oh.error == -ENOSYS)
1924 fc->no_interrupt = 1;
1925 else if (oh.error == -EAGAIN)
1926 queue_interrupt(fc, req);
1928 spin_unlock(&fc->lock);
1929 fuse_copy_finish(cs);
1933 req->state = FUSE_REQ_WRITING;
1934 list_move(&req->list, &fc->io);
1938 if (!req->out.page_replace)
1940 spin_unlock(&fc->lock);
1942 err = copy_out_args(cs, &req->out, nbytes);
1943 fuse_copy_finish(cs);
1945 spin_lock(&fc->lock);
1950 } else if (!req->aborted)
1951 req->out.h.error = -EIO;
1952 request_end(fc, req);
1954 return err ? err : nbytes;
1957 spin_unlock(&fc->lock);
1959 fuse_copy_finish(cs);
1963 static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
1964 unsigned long nr_segs, loff_t pos)
1966 struct fuse_copy_state cs;
1967 struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
1971 fuse_copy_init(&cs, fc, 0, iov, nr_segs);
1973 return fuse_dev_do_write(fc, &cs, iov_length(iov, nr_segs));
1976 static ssize_t fuse_dev_splice_write(struct pipe_inode_info *pipe,
1977 struct file *out, loff_t *ppos,
1978 size_t len, unsigned int flags)
1982 struct pipe_buffer *bufs;
1983 struct fuse_copy_state cs;
1984 struct fuse_conn *fc;
1988 fc = fuse_get_conn(out);
1992 bufs = kmalloc(pipe->buffers * sizeof(struct pipe_buffer), GFP_KERNEL);
1999 for (idx = 0; idx < pipe->nrbufs && rem < len; idx++)
2000 rem += pipe->bufs[(pipe->curbuf + idx) & (pipe->buffers - 1)].len;
2010 struct pipe_buffer *ibuf;
2011 struct pipe_buffer *obuf;
2013 BUG_ON(nbuf >= pipe->buffers);
2014 BUG_ON(!pipe->nrbufs);
2015 ibuf = &pipe->bufs[pipe->curbuf];
2018 if (rem >= ibuf->len) {
2021 pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
2024 ibuf->ops->get(pipe, ibuf);
2026 obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
2028 ibuf->offset += obuf->len;
2029 ibuf->len -= obuf->len;
2036 fuse_copy_init(&cs, fc, 0, NULL, nbuf);
2040 if (flags & SPLICE_F_MOVE)
2043 ret = fuse_dev_do_write(fc, &cs, len);
2045 for (idx = 0; idx < nbuf; idx++) {
2046 struct pipe_buffer *buf = &bufs[idx];
2047 buf->ops->release(pipe, buf);
2054 static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
2056 unsigned mask = POLLOUT | POLLWRNORM;
2057 struct fuse_conn *fc = fuse_get_conn(file);
2061 poll_wait(file, &fc->waitq, wait);
2063 spin_lock(&fc->lock);
2066 else if (request_pending(fc))
2067 mask |= POLLIN | POLLRDNORM;
2068 spin_unlock(&fc->lock);
2074 * Abort all requests on the given list (pending or processing)
2076 * This function releases and reacquires fc->lock
2078 static void end_requests(struct fuse_conn *fc, struct list_head *head)
2079 __releases(fc->lock)
2080 __acquires(fc->lock)
2082 while (!list_empty(head)) {
2083 struct fuse_req *req;
2084 req = list_entry(head->next, struct fuse_req, list);
2085 req->out.h.error = -ECONNABORTED;
2086 request_end(fc, req);
2087 spin_lock(&fc->lock);
2092 * Abort requests under I/O
2094 * The requests are set to aborted and finished, and the request
2095 * waiter is woken up. This will make request_wait_answer() wait
2096 * until the request is unlocked and then return.
2098 * If the request is asynchronous, then the end function needs to be
2099 * called after waiting for the request to be unlocked (if it was
2102 static void end_io_requests(struct fuse_conn *fc)
2103 __releases(fc->lock)
2104 __acquires(fc->lock)
2106 while (!list_empty(&fc->io)) {
2107 struct fuse_req *req =
2108 list_entry(fc->io.next, struct fuse_req, list);
2109 void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
2112 req->out.h.error = -ECONNABORTED;
2113 req->state = FUSE_REQ_FINISHED;
2114 list_del_init(&req->list);
2115 wake_up(&req->waitq);
2118 __fuse_get_request(req);
2119 spin_unlock(&fc->lock);
2120 wait_event(req->waitq, !req->locked);
2122 fuse_put_request(fc, req);
2123 spin_lock(&fc->lock);
2128 static void end_queued_requests(struct fuse_conn *fc)
2129 __releases(fc->lock)
2130 __acquires(fc->lock)
2132 fc->max_background = UINT_MAX;
2134 end_requests(fc, &fc->pending);
2135 end_requests(fc, &fc->processing);
2136 while (forget_pending(fc))
2137 kfree(dequeue_forget(fc, 1, NULL));
2140 static void end_polls(struct fuse_conn *fc)
2144 p = rb_first(&fc->polled_files);
2147 struct fuse_file *ff;
2148 ff = rb_entry(p, struct fuse_file, polled_node);
2149 wake_up_interruptible_all(&ff->poll_wait);
2156 * Abort all requests.
2158 * Emergency exit in case of a malicious or accidental deadlock, or
2159 * just a hung filesystem.
2161 * The same effect is usually achievable through killing the
2162 * filesystem daemon and all users of the filesystem. The exception
2163 * is the combination of an asynchronous request and the tricky
2164 * deadlock (see Documentation/filesystems/fuse.txt).
2166 * During the aborting, progression of requests from the pending and
2167 * processing lists onto the io list, and progression of new requests
2168 * onto the pending list is prevented by req->connected being false.
2170 * Progression of requests under I/O to the processing list is
2171 * prevented by the req->aborted flag being true for these requests.
2172 * For this reason requests on the io list must be aborted first.
2174 void fuse_abort_conn(struct fuse_conn *fc)
2176 spin_lock(&fc->lock);
2177 if (fc->connected) {
2180 fuse_set_initialized(fc);
2181 end_io_requests(fc);
2182 end_queued_requests(fc);
2184 wake_up_all(&fc->waitq);
2185 wake_up_all(&fc->blocked_waitq);
2186 kill_fasync(&fc->fasync, SIGIO, POLL_IN);
2188 spin_unlock(&fc->lock);
2190 EXPORT_SYMBOL_GPL(fuse_abort_conn);
2192 int fuse_dev_release(struct inode *inode, struct file *file)
2194 struct fuse_conn *fc = fuse_get_conn(file);
2196 spin_lock(&fc->lock);
2199 fuse_set_initialized(fc);
2200 end_queued_requests(fc);
2202 wake_up_all(&fc->blocked_waitq);
2203 spin_unlock(&fc->lock);
2209 EXPORT_SYMBOL_GPL(fuse_dev_release);
2211 static int fuse_dev_fasync(int fd, struct file *file, int on)
2213 struct fuse_conn *fc = fuse_get_conn(file);
2217 /* No locking - fasync_helper does its own locking */
2218 return fasync_helper(fd, file, on, &fc->fasync);
2221 const struct file_operations fuse_dev_operations = {
2222 .owner = THIS_MODULE,
2223 .llseek = no_llseek,
2224 .read = do_sync_read,
2225 .aio_read = fuse_dev_read,
2226 .splice_read = fuse_dev_splice_read,
2227 .write = do_sync_write,
2228 .aio_write = fuse_dev_write,
2229 .splice_write = fuse_dev_splice_write,
2230 .poll = fuse_dev_poll,
2231 .release = fuse_dev_release,
2232 .fasync = fuse_dev_fasync,
2234 EXPORT_SYMBOL_GPL(fuse_dev_operations);
2236 static struct miscdevice fuse_miscdevice = {
2237 .minor = FUSE_MINOR,
2239 .fops = &fuse_dev_operations,
2242 int __init fuse_dev_init(void)
2245 fuse_req_cachep = kmem_cache_create("fuse_request",
2246 sizeof(struct fuse_req),
2248 if (!fuse_req_cachep)
2251 err = misc_register(&fuse_miscdevice);
2253 goto out_cache_clean;
2258 kmem_cache_destroy(fuse_req_cachep);
2263 void fuse_dev_cleanup(void)
2265 misc_deregister(&fuse_miscdevice);
2266 kmem_cache_destroy(fuse_req_cachep);