1/*
2  FUSE: Filesystem in Userspace
3  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
4
5  This program can be distributed under the terms of the GNU GPL.
6  See the file COPYING.
7*/
8
9#ifndef _FS_FUSE_I_H
10#define _FS_FUSE_I_H
11
12#include <linux/fuse.h>
13#include <linux/fs.h>
14#include <linux/mount.h>
15#include <linux/wait.h>
16#include <linux/list.h>
17#include <linux/spinlock.h>
18#include <linux/mm.h>
19#include <linux/backing-dev.h>
20#include <linux/mutex.h>
21#include <linux/rwsem.h>
22#include <linux/rbtree.h>
23#include <linux/poll.h>
24#include <linux/workqueue.h>
25#include <linux/kref.h>
26
27/** Max number of pages that can be used in a single read request */
28#define FUSE_MAX_PAGES_PER_REQ 32
29
30/** Bias for fi->writectr, meaning new writepages must not be sent */
31#define FUSE_NOWRITE INT_MIN
32
33/** It could be as large as PATH_MAX, but would that have any uses? */
34#define FUSE_NAME_MAX 1024
35
36/** Number of dentries for each connection in the control filesystem */
37#define FUSE_CTL_NUM_DENTRIES 5
38
39/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
40    module will check permissions based on the file mode.  Otherwise no
41    permission checking is done in the kernel */
42#define FUSE_DEFAULT_PERMISSIONS (1 << 0)
43
44/** If the FUSE_ALLOW_OTHER flag is given, then not only the user
45    doing the mount will be allowed to access the filesystem */
46#define FUSE_ALLOW_OTHER         (1 << 1)
47
48/** Number of page pointers embedded in fuse_req */
49#define FUSE_REQ_INLINE_PAGES 1
50
51/** List of active connections */
52extern struct list_head fuse_conn_list;
53
54/** Global mutex protecting fuse_conn_list and the control filesystem */
55extern struct mutex fuse_mutex;
56
57/** Module parameters */
58extern unsigned max_user_bgreq;
59extern unsigned max_user_congthresh;
60
61/* One forget request */
62struct fuse_forget_link {
63	struct fuse_forget_one forget_one;
64	struct fuse_forget_link *next;
65};
66
67/** FUSE inode */
68struct fuse_inode {
69	/** Inode data */
70	struct inode inode;
71
72	/** Unique ID, which identifies the inode between userspace
73	 * and kernel */
74	u64 nodeid;
75
76	/** Number of lookups on this inode */
77	u64 nlookup;
78
79	/** The request used for sending the FORGET message */
80	struct fuse_forget_link *forget;
81
82	/** Time in jiffies until the file attributes are valid */
83	u64 i_time;
84
85	/** The sticky bit in inode->i_mode may have been removed, so
86	    preserve the original mode */
87	umode_t orig_i_mode;
88
89	/** 64 bit inode number */
90	u64 orig_ino;
91
92	/** Version of last attribute change */
93	u64 attr_version;
94
95	/** Files usable in writepage.  Protected by fc->lock */
96	struct list_head write_files;
97
98	/** Writepages pending on truncate or fsync */
99	struct list_head queued_writes;
100
101	/** Number of sent writes, a negative bias (FUSE_NOWRITE)
102	 * means more writes are blocked */
103	int writectr;
104
105	/** Waitq for writepage completion */
106	wait_queue_head_t page_waitq;
107
108	/** List of writepage requestst (pending or sent) */
109	struct list_head writepages;
110
111	/** Miscellaneous bits describing inode state */
112	unsigned long state;
113};
114
115/** FUSE inode state bits */
116enum {
117	/** Advise readdirplus  */
118	FUSE_I_ADVISE_RDPLUS,
119	/** Initialized with readdirplus */
120	FUSE_I_INIT_RDPLUS,
121	/** An operation changing file size is in progress  */
122	FUSE_I_SIZE_UNSTABLE,
123};
124
125struct fuse_conn;
126
127/** FUSE specific file data */
128struct fuse_file {
129	/** Fuse connection for this file */
130	struct fuse_conn *fc;
131
132	/** Request reserved for flush and release */
133	struct fuse_req *reserved_req;
134
135	/** Kernel file handle guaranteed to be unique */
136	u64 kh;
137
138	/** File handle used by userspace */
139	u64 fh;
140
141	/** Node id of this file */
142	u64 nodeid;
143
144	/** Refcount */
145	atomic_t count;
146
147	/** FOPEN_* flags returned by open */
148	u32 open_flags;
149
150	/** Entry on inode's write_files list */
151	struct list_head write_entry;
152
153	/** RB node to be linked on fuse_conn->polled_files */
154	struct rb_node polled_node;
155
156	/** Wait queue head for poll */
157	wait_queue_head_t poll_wait;
158
159	/** Has flock been performed on this file? */
160	bool flock:1;
161};
162
163/** One input argument of a request */
164struct fuse_in_arg {
165	unsigned size;
166	const void *value;
167};
168
169/** The request input */
170struct fuse_in {
171	/** The request header */
172	struct fuse_in_header h;
173
174	/** True if the data for the last argument is in req->pages */
175	unsigned argpages:1;
176
177	/** Number of arguments */
178	unsigned numargs;
179
180	/** Array of arguments */
181	struct fuse_in_arg args[3];
182};
183
184/** One output argument of a request */
185struct fuse_arg {
186	unsigned size;
187	void *value;
188};
189
190/** The request output */
191struct fuse_out {
192	/** Header returned from userspace */
193	struct fuse_out_header h;
194
195	/*
196	 * The following bitfields are not changed during the request
197	 * processing
198	 */
199
200	/** Last argument is variable length (can be shorter than
201	    arg->size) */
202	unsigned argvar:1;
203
204	/** Last argument is a list of pages to copy data to */
205	unsigned argpages:1;
206
207	/** Zero partially or not copied pages */
208	unsigned page_zeroing:1;
209
210	/** Pages may be replaced with new ones */
211	unsigned page_replace:1;
212
213	/** Number or arguments */
214	unsigned numargs;
215
216	/** Array of arguments */
217	struct fuse_arg args[2];
218};
219
220/** FUSE page descriptor */
221struct fuse_page_desc {
222	unsigned int length;
223	unsigned int offset;
224};
225
226struct fuse_args {
227	struct {
228		struct {
229			uint32_t opcode;
230			uint64_t nodeid;
231		} h;
232		unsigned numargs;
233		struct fuse_in_arg args[3];
234
235	} in;
236	struct {
237		unsigned argvar:1;
238		unsigned numargs;
239		struct fuse_arg args[2];
240	} out;
241};
242
243#define FUSE_ARGS(args) struct fuse_args args = {}
244
245/** The request IO state (for asynchronous processing) */
246struct fuse_io_priv {
247	struct kref refcnt;
248	int async;
249	spinlock_t lock;
250	unsigned reqs;
251	ssize_t bytes;
252	size_t size;
253	__u64 offset;
254	bool write;
255	int err;
256	struct kiocb *iocb;
257	struct file *file;
258	struct completion *done;
259};
260
261#define FUSE_IO_PRIV_SYNC(f) \
262{					\
263	.refcnt = { ATOMIC_INIT(1) },	\
264	.async = 0,			\
265	.file = f,			\
266}
267
268/**
269 * Request flags
270 *
271 * FR_ISREPLY:		set if the request has reply
272 * FR_FORCE:		force sending of the request even if interrupted
273 * FR_BACKGROUND:	request is sent in the background
274 * FR_WAITING:		request is counted as "waiting"
275 * FR_ABORTED:		the request was aborted
276 * FR_INTERRUPTED:	the request has been interrupted
277 * FR_LOCKED:		data is being copied to/from the request
278 * FR_PENDING:		request is not yet in userspace
279 * FR_SENT:		request is in userspace, waiting for an answer
280 * FR_FINISHED:		request is finished
281 * FR_PRIVATE:		request is on private list
282 */
283enum fuse_req_flag {
284	FR_ISREPLY,
285	FR_FORCE,
286	FR_BACKGROUND,
287	FR_WAITING,
288	FR_ABORTED,
289	FR_INTERRUPTED,
290	FR_LOCKED,
291	FR_PENDING,
292	FR_SENT,
293	FR_FINISHED,
294	FR_PRIVATE,
295};
296
297/**
298 * A request to the client
299 *
300 * .waitq.lock protects the following fields:
301 *   - FR_ABORTED
302 *   - FR_LOCKED (may also be modified under fc->lock, tested under both)
303 */
304struct fuse_req {
305	/** This can be on either pending processing or io lists in
306	    fuse_conn */
307	struct list_head list;
308
309	/** Entry on the interrupts list  */
310	struct list_head intr_entry;
311
312	/** refcount */
313	atomic_t count;
314
315	/** Unique ID for the interrupt request */
316	u64 intr_unique;
317
318	/* Request flags, updated with test/set/clear_bit() */
319	unsigned long flags;
320
321	/** The request input */
322	struct fuse_in in;
323
324	/** The request output */
325	struct fuse_out out;
326
327	/** Used to wake up the task waiting for completion of request*/
328	wait_queue_head_t waitq;
329
330	/** Data for asynchronous requests */
331	union {
332		struct {
333			struct fuse_release_in in;
334			struct inode *inode;
335		} release;
336		struct fuse_init_in init_in;
337		struct fuse_init_out init_out;
338		struct cuse_init_in cuse_init_in;
339		struct {
340			struct fuse_read_in in;
341			u64 attr_ver;
342		} read;
343		struct {
344			struct fuse_write_in in;
345			struct fuse_write_out out;
346			struct fuse_req *next;
347		} write;
348		struct fuse_notify_retrieve_in retrieve_in;
349	} misc;
350
351	/** page vector */
352	struct page **pages;
353
354	/** page-descriptor vector */
355	struct fuse_page_desc *page_descs;
356
357	/** size of the 'pages' array */
358	unsigned max_pages;
359
360	/** inline page vector */
361	struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
362
363	/** inline page-descriptor vector */
364	struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
365
366	/** number of pages in vector */
367	unsigned num_pages;
368
369	/** File used in the request (or NULL) */
370	struct fuse_file *ff;
371
372	/** Inode used in the request or NULL */
373	struct inode *inode;
374
375	/** AIO control block */
376	struct fuse_io_priv *io;
377
378	/** Link on fi->writepages */
379	struct list_head writepages_entry;
380
381	/** Request completion callback */
382	void (*end)(struct fuse_conn *, struct fuse_req *);
383
384	/** Request is stolen from fuse_file->reserved_req */
385	struct file *stolen_file;
386};
387
388struct fuse_iqueue {
389	/** Connection established */
390	unsigned connected;
391
392	/** Readers of the connection are waiting on this */
393	wait_queue_head_t waitq;
394
395	/** The next unique request id */
396	u64 reqctr;
397
398	/** The list of pending requests */
399	struct list_head pending;
400
401	/** Pending interrupts */
402	struct list_head interrupts;
403
404	/** Queue of pending forgets */
405	struct fuse_forget_link forget_list_head;
406	struct fuse_forget_link *forget_list_tail;
407
408	/** Batching of FORGET requests (positive indicates FORGET batch) */
409	int forget_batch;
410
411	/** O_ASYNC requests */
412	struct fasync_struct *fasync;
413};
414
415struct fuse_pqueue {
416	/** Connection established */
417	unsigned connected;
418
419	/** Lock protecting accessess to  members of this structure */
420	spinlock_t lock;
421
422	/** The list of requests being processed */
423	struct list_head processing;
424
425	/** The list of requests under I/O */
426	struct list_head io;
427};
428
429/**
430 * Fuse device instance
431 */
432struct fuse_dev {
433	/** Fuse connection for this device */
434	struct fuse_conn *fc;
435
436	/** Processing queue */
437	struct fuse_pqueue pq;
438
439	/** list entry on fc->devices */
440	struct list_head entry;
441};
442
443/**
444 * A Fuse connection.
445 *
446 * This structure is created, when the filesystem is mounted, and is
447 * destroyed, when the client device is closed and the filesystem is
448 * unmounted.
449 */
450struct fuse_conn {
451	/** Lock protecting accessess to  members of this structure */
452	spinlock_t lock;
453
454	/** Refcount */
455	atomic_t count;
456
457	/** Number of fuse_dev's */
458	atomic_t dev_count;
459
460	struct rcu_head rcu;
461
462	/** The user id for this mount */
463	kuid_t user_id;
464
465	/** The group id for this mount */
466	kgid_t group_id;
467
468	/** The fuse mount flags for this mount */
469	unsigned flags;
470
471	/** Maximum read size */
472	unsigned max_read;
473
474	/** Maximum write size */
475	unsigned max_write;
476
477	/** Input queue */
478	struct fuse_iqueue iq;
479
480	/** The next unique kernel file handle */
481	u64 khctr;
482
483	/** rbtree of fuse_files waiting for poll events indexed by ph */
484	struct rb_root polled_files;
485
486	/** Maximum number of outstanding background requests */
487	unsigned max_background;
488
489	/** Number of background requests at which congestion starts */
490	unsigned congestion_threshold;
491
492	/** Number of requests currently in the background */
493	unsigned num_background;
494
495	/** Number of background requests currently queued for userspace */
496	unsigned active_background;
497
498	/** The list of background requests set aside for later queuing */
499	struct list_head bg_queue;
500
501	/** Flag indicating that INIT reply has been received. Allocating
502	 * any fuse request will be suspended until the flag is set */
503	int initialized;
504
505	/** Flag indicating if connection is blocked.  This will be
506	    the case before the INIT reply is received, and if there
507	    are too many outstading backgrounds requests */
508	int blocked;
509
510	/** waitq for blocked connection */
511	wait_queue_head_t blocked_waitq;
512
513	/** waitq for reserved requests */
514	wait_queue_head_t reserved_req_waitq;
515
516	/** Connection established, cleared on umount, connection
517	    abort and device release */
518	unsigned connected;
519
520	/** Connection failed (version mismatch).  Cannot race with
521	    setting other bitfields since it is only set once in INIT
522	    reply, before any other request, and never cleared */
523	unsigned conn_error:1;
524
525	/** Connection successful.  Only set in INIT */
526	unsigned conn_init:1;
527
528	/** Do readpages asynchronously?  Only set in INIT */
529	unsigned async_read:1;
530
531	/** Do not send separate SETATTR request before open(O_TRUNC)  */
532	unsigned atomic_o_trunc:1;
533
534	/** Filesystem supports NFS exporting.  Only set in INIT */
535	unsigned export_support:1;
536
537	/** Set if bdi is valid */
538	unsigned bdi_initialized:1;
539
540	/** write-back cache policy (default is write-through) */
541	unsigned writeback_cache:1;
542
543	/*
544	 * The following bitfields are only for optimization purposes
545	 * and hence races in setting them will not cause malfunction
546	 */
547
548	/** Is open/release not implemented by fs? */
549	unsigned no_open:1;
550
551	/** Is fsync not implemented by fs? */
552	unsigned no_fsync:1;
553
554	/** Is fsyncdir not implemented by fs? */
555	unsigned no_fsyncdir:1;
556
557	/** Is flush not implemented by fs? */
558	unsigned no_flush:1;
559
560	/** Is setxattr not implemented by fs? */
561	unsigned no_setxattr:1;
562
563	/** Is getxattr not implemented by fs? */
564	unsigned no_getxattr:1;
565
566	/** Is listxattr not implemented by fs? */
567	unsigned no_listxattr:1;
568
569	/** Is removexattr not implemented by fs? */
570	unsigned no_removexattr:1;
571
572	/** Are posix file locking primitives not implemented by fs? */
573	unsigned no_lock:1;
574
575	/** Is access not implemented by fs? */
576	unsigned no_access:1;
577
578	/** Is create not implemented by fs? */
579	unsigned no_create:1;
580
581	/** Is interrupt not implemented by fs? */
582	unsigned no_interrupt:1;
583
584	/** Is bmap not implemented by fs? */
585	unsigned no_bmap:1;
586
587	/** Is poll not implemented by fs? */
588	unsigned no_poll:1;
589
590	/** Do multi-page cached writes */
591	unsigned big_writes:1;
592
593	/** Don't apply umask to creation modes */
594	unsigned dont_mask:1;
595
596	/** Are BSD file locking primitives not implemented by fs? */
597	unsigned no_flock:1;
598
599	/** Is fallocate not implemented by fs? */
600	unsigned no_fallocate:1;
601
602	/** Is rename with flags implemented by fs? */
603	unsigned no_rename2:1;
604
605	/** Use enhanced/automatic page cache invalidation. */
606	unsigned auto_inval_data:1;
607
608	/** Does the filesystem support readdirplus? */
609	unsigned do_readdirplus:1;
610
611	/** Does the filesystem want adaptive readdirplus? */
612	unsigned readdirplus_auto:1;
613
614	/** Does the filesystem support asynchronous direct-IO submission? */
615	unsigned async_dio:1;
616
617	/** The number of requests waiting for completion */
618	atomic_t num_waiting;
619
620	/** Negotiated minor version */
621	unsigned minor;
622
623	/** Backing dev info */
624	struct backing_dev_info bdi;
625
626	/** Entry on the fuse_conn_list */
627	struct list_head entry;
628
629	/** Device ID from super block */
630	dev_t dev;
631
632	/** Dentries in the control filesystem */
633	struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
634
635	/** number of dentries used in the above array */
636	int ctl_ndents;
637
638	/** Key for lock owner ID scrambling */
639	u32 scramble_key[4];
640
641	/** Reserved request for the DESTROY message */
642	struct fuse_req *destroy_req;
643
644	/** Version counter for attribute changes */
645	u64 attr_version;
646
647	/** Called on final put */
648	void (*release)(struct fuse_conn *);
649
650	/** Super block for this connection. */
651	struct super_block *sb;
652
653	/** Read/write semaphore to hold when accessing sb. */
654	struct rw_semaphore killsb;
655
656	/** List of device instances belonging to this connection */
657	struct list_head devices;
658};
659
660static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
661{
662	return sb->s_fs_info;
663}
664
665static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
666{
667	return get_fuse_conn_super(inode->i_sb);
668}
669
670static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
671{
672	return container_of(inode, struct fuse_inode, inode);
673}
674
675static inline u64 get_node_id(struct inode *inode)
676{
677	return get_fuse_inode(inode)->nodeid;
678}
679
680/** Device operations */
681extern const struct file_operations fuse_dev_operations;
682
683extern const struct dentry_operations fuse_dentry_operations;
684
685/**
686 * Inode to nodeid comparison.
687 */
688int fuse_inode_eq(struct inode *inode, void *_nodeidp);
689
690/**
691 * Get a filled in inode
692 */
693struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
694			int generation, struct fuse_attr *attr,
695			u64 attr_valid, u64 attr_version);
696
697int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
698		     struct fuse_entry_out *outarg, struct inode **inode);
699
700/**
701 * Send FORGET command
702 */
703void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
704		       u64 nodeid, u64 nlookup);
705
706struct fuse_forget_link *fuse_alloc_forget(void);
707
708/* Used by READDIRPLUS */
709void fuse_force_forget(struct file *file, u64 nodeid);
710
711/**
712 * Initialize READ or READDIR request
713 */
714void fuse_read_fill(struct fuse_req *req, struct file *file,
715		    loff_t pos, size_t count, int opcode);
716
717/**
718 * Send OPEN or OPENDIR request
719 */
720int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
721
722struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
723struct fuse_file *fuse_file_get(struct fuse_file *ff);
724void fuse_file_free(struct fuse_file *ff);
725void fuse_finish_open(struct inode *inode, struct file *file);
726
727void fuse_sync_release(struct fuse_file *ff, int flags);
728
729/**
730 * Send RELEASE or RELEASEDIR request
731 */
732void fuse_release_common(struct file *file, int opcode);
733
734/**
735 * Send FSYNC or FSYNCDIR request
736 */
737int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
738		      int datasync, int isdir);
739
740/**
741 * Notify poll wakeup
742 */
743int fuse_notify_poll_wakeup(struct fuse_conn *fc,
744			    struct fuse_notify_poll_wakeup_out *outarg);
745
746/**
747 * Initialize file operations on a regular file
748 */
749void fuse_init_file_inode(struct inode *inode);
750
751/**
752 * Initialize inode operations on regular files and special files
753 */
754void fuse_init_common(struct inode *inode);
755
756/**
757 * Initialize inode and file operations on a directory
758 */
759void fuse_init_dir(struct inode *inode);
760
761/**
762 * Initialize inode operations on a symlink
763 */
764void fuse_init_symlink(struct inode *inode);
765
766/**
767 * Change attributes of an inode
768 */
769void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
770			    u64 attr_valid, u64 attr_version);
771
772void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
773				   u64 attr_valid);
774
775/**
776 * Initialize the client device
777 */
778int fuse_dev_init(void);
779
780/**
781 * Cleanup the client device
782 */
783void fuse_dev_cleanup(void);
784
785int fuse_ctl_init(void);
786void __exit fuse_ctl_cleanup(void);
787
788/**
789 * Allocate a request
790 */
791struct fuse_req *fuse_request_alloc(unsigned npages);
792
793struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
794
795/**
796 * Free a request
797 */
798void fuse_request_free(struct fuse_req *req);
799
800/**
801 * Get a request, may fail with -ENOMEM,
802 * caller should specify # elements in req->pages[] explicitly
803 */
804struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
805struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
806					     unsigned npages);
807
808/*
809 * Increment reference count on request
810 */
811void __fuse_get_request(struct fuse_req *req);
812
813/**
814 * Gets a requests for a file operation, always succeeds
815 */
816struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
817					     struct file *file);
818
819/**
820 * Decrement reference count of a request.  If count goes to zero free
821 * the request.
822 */
823void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
824
825/**
826 * Send a request (synchronous)
827 */
828void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
829
830/**
831 * Simple request sending that does request allocation and freeing
832 */
833ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
834
835/**
836 * Send a request in the background
837 */
838void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
839
840void fuse_request_send_background_locked(struct fuse_conn *fc,
841					 struct fuse_req *req);
842
843/* Abort all requests */
844void fuse_abort_conn(struct fuse_conn *fc);
845
846/**
847 * Invalidate inode attributes
848 */
849void fuse_invalidate_attr(struct inode *inode);
850
851void fuse_invalidate_entry_cache(struct dentry *entry);
852
853void fuse_invalidate_atime(struct inode *inode);
854
855/**
856 * Acquire reference to fuse_conn
857 */
858struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
859
860/**
861 * Initialize fuse_conn
862 */
863void fuse_conn_init(struct fuse_conn *fc);
864
865/**
866 * Release reference to fuse_conn
867 */
868void fuse_conn_put(struct fuse_conn *fc);
869
870struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc);
871void fuse_dev_free(struct fuse_dev *fud);
872
873/**
874 * Add connection to control filesystem
875 */
876int fuse_ctl_add_conn(struct fuse_conn *fc);
877
878/**
879 * Remove connection from control filesystem
880 */
881void fuse_ctl_remove_conn(struct fuse_conn *fc);
882
883/**
884 * Is file type valid?
885 */
886int fuse_valid_type(int m);
887
888/**
889 * Is current process allowed to perform filesystem operation?
890 */
891int fuse_allow_current_process(struct fuse_conn *fc);
892
893u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
894
895int fuse_update_attributes(struct inode *inode, struct kstat *stat,
896			   struct file *file, bool *refreshed);
897
898void fuse_flush_writepages(struct inode *inode);
899
900void fuse_set_nowrite(struct inode *inode);
901void fuse_release_nowrite(struct inode *inode);
902
903u64 fuse_get_attr_version(struct fuse_conn *fc);
904
905/**
906 * File-system tells the kernel to invalidate cache for the given node id.
907 */
908int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
909			     loff_t offset, loff_t len);
910
911/**
912 * File-system tells the kernel to invalidate parent attributes and
913 * the dentry matching parent/name.
914 *
915 * If the child_nodeid is non-zero and:
916 *    - matches the inode number for the dentry matching parent/name,
917 *    - is not a mount point
918 *    - is a file or oan empty directory
919 * then the dentry is unhashed (d_delete()).
920 */
921int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
922			     u64 child_nodeid, struct qstr *name);
923
924int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
925		 bool isdir);
926
927/**
928 * fuse_direct_io() flags
929 */
930
931/** If set, it is WRITE; otherwise - READ */
932#define FUSE_DIO_WRITE (1 << 0)
933
934/** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
935#define FUSE_DIO_CUSE  (1 << 1)
936
937ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
938		       loff_t *ppos, int flags);
939long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
940		   unsigned int flags);
941long fuse_ioctl_common(struct file *file, unsigned int cmd,
942		       unsigned long arg, unsigned int flags);
943unsigned fuse_file_poll(struct file *file, poll_table *wait);
944int fuse_dev_release(struct inode *inode, struct file *file);
945
946bool fuse_write_update_size(struct inode *inode, loff_t pos);
947
948int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
949int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
950
951int fuse_do_setattr(struct inode *inode, struct iattr *attr,
952		    struct file *file);
953
954void fuse_set_initialized(struct fuse_conn *fc);
955
956#endif /* _FS_FUSE_I_H */
957