xref: /openbmc/linux/fs/fuse/fuse_i.h (revision 8e9356c6)
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 
26 /** Max number of pages that can be used in a single read request */
27 #define FUSE_MAX_PAGES_PER_REQ 32
28 
29 /** Bias for fi->writectr, meaning new writepages must not be sent */
30 #define FUSE_NOWRITE INT_MIN
31 
32 /** It could be as large as PATH_MAX, but would that have any uses? */
33 #define FUSE_NAME_MAX 1024
34 
35 /** Number of dentries for each connection in the control filesystem */
36 #define FUSE_CTL_NUM_DENTRIES 5
37 
38 /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
39     module will check permissions based on the file mode.  Otherwise no
40     permission checking is done in the kernel */
41 #define FUSE_DEFAULT_PERMISSIONS (1 << 0)
42 
43 /** If the FUSE_ALLOW_OTHER flag is given, then not only the user
44     doing the mount will be allowed to access the filesystem */
45 #define FUSE_ALLOW_OTHER         (1 << 1)
46 
47 /** Number of page pointers embedded in fuse_req */
48 #define FUSE_REQ_INLINE_PAGES 1
49 
50 /** List of active connections */
51 extern struct list_head fuse_conn_list;
52 
53 /** Global mutex protecting fuse_conn_list and the control filesystem */
54 extern struct mutex fuse_mutex;
55 
56 /** Module parameters */
57 extern unsigned max_user_bgreq;
58 extern unsigned max_user_congthresh;
59 
60 /* One forget request */
61 struct fuse_forget_link {
62 	struct fuse_forget_one forget_one;
63 	struct fuse_forget_link *next;
64 };
65 
66 /** FUSE inode */
67 struct fuse_inode {
68 	/** Inode data */
69 	struct inode inode;
70 
71 	/** Unique ID, which identifies the inode between userspace
72 	 * and kernel */
73 	u64 nodeid;
74 
75 	/** Number of lookups on this inode */
76 	u64 nlookup;
77 
78 	/** The request used for sending the FORGET message */
79 	struct fuse_forget_link *forget;
80 
81 	/** Time in jiffies until the file attributes are valid */
82 	u64 i_time;
83 
84 	/** The sticky bit in inode->i_mode may have been removed, so
85 	    preserve the original mode */
86 	umode_t orig_i_mode;
87 
88 	/** 64 bit inode number */
89 	u64 orig_ino;
90 
91 	/** Version of last attribute change */
92 	u64 attr_version;
93 
94 	/** Files usable in writepage.  Protected by fc->lock */
95 	struct list_head write_files;
96 
97 	/** Writepages pending on truncate or fsync */
98 	struct list_head queued_writes;
99 
100 	/** Number of sent writes, a negative bias (FUSE_NOWRITE)
101 	 * means more writes are blocked */
102 	int writectr;
103 
104 	/** Waitq for writepage completion */
105 	wait_queue_head_t page_waitq;
106 
107 	/** List of writepage requestst (pending or sent) */
108 	struct list_head writepages;
109 
110 	/** Miscellaneous bits describing inode state */
111 	unsigned long state;
112 };
113 
114 /** FUSE inode state bits */
115 enum {
116 	/** Advise readdirplus  */
117 	FUSE_I_ADVISE_RDPLUS,
118 	/** Initialized with readdirplus */
119 	FUSE_I_INIT_RDPLUS,
120 	/** An operation changing file size is in progress  */
121 	FUSE_I_SIZE_UNSTABLE,
122 };
123 
124 struct fuse_conn;
125 
126 /** FUSE specific file data */
127 struct fuse_file {
128 	/** Fuse connection for this file */
129 	struct fuse_conn *fc;
130 
131 	/** Request reserved for flush and release */
132 	struct fuse_req *reserved_req;
133 
134 	/** Kernel file handle guaranteed to be unique */
135 	u64 kh;
136 
137 	/** File handle used by userspace */
138 	u64 fh;
139 
140 	/** Node id of this file */
141 	u64 nodeid;
142 
143 	/** Refcount */
144 	atomic_t count;
145 
146 	/** FOPEN_* flags returned by open */
147 	u32 open_flags;
148 
149 	/** Entry on inode's write_files list */
150 	struct list_head write_entry;
151 
152 	/** RB node to be linked on fuse_conn->polled_files */
153 	struct rb_node polled_node;
154 
155 	/** Wait queue head for poll */
156 	wait_queue_head_t poll_wait;
157 
158 	/** Has flock been performed on this file? */
159 	bool flock:1;
160 };
161 
162 /** One input argument of a request */
163 struct fuse_in_arg {
164 	unsigned size;
165 	const void *value;
166 };
167 
168 /** The request input */
169 struct fuse_in {
170 	/** The request header */
171 	struct fuse_in_header h;
172 
173 	/** True if the data for the last argument is in req->pages */
174 	unsigned argpages:1;
175 
176 	/** Number of arguments */
177 	unsigned numargs;
178 
179 	/** Array of arguments */
180 	struct fuse_in_arg args[3];
181 };
182 
183 /** One output argument of a request */
184 struct fuse_arg {
185 	unsigned size;
186 	void *value;
187 };
188 
189 /** The request output */
190 struct fuse_out {
191 	/** Header returned from userspace */
192 	struct fuse_out_header h;
193 
194 	/*
195 	 * The following bitfields are not changed during the request
196 	 * processing
197 	 */
198 
199 	/** Last argument is variable length (can be shorter than
200 	    arg->size) */
201 	unsigned argvar:1;
202 
203 	/** Last argument is a list of pages to copy data to */
204 	unsigned argpages:1;
205 
206 	/** Zero partially or not copied pages */
207 	unsigned page_zeroing:1;
208 
209 	/** Pages may be replaced with new ones */
210 	unsigned page_replace:1;
211 
212 	/** Number or arguments */
213 	unsigned numargs;
214 
215 	/** Array of arguments */
216 	struct fuse_arg args[3];
217 };
218 
219 /** FUSE page descriptor */
220 struct fuse_page_desc {
221 	unsigned int length;
222 	unsigned int offset;
223 };
224 
225 /** The request state */
226 enum fuse_req_state {
227 	FUSE_REQ_INIT = 0,
228 	FUSE_REQ_PENDING,
229 	FUSE_REQ_READING,
230 	FUSE_REQ_SENT,
231 	FUSE_REQ_WRITING,
232 	FUSE_REQ_FINISHED
233 };
234 
235 /** The request IO state (for asynchronous processing) */
236 struct fuse_io_priv {
237 	int async;
238 	spinlock_t lock;
239 	unsigned reqs;
240 	ssize_t bytes;
241 	size_t size;
242 	__u64 offset;
243 	bool write;
244 	int err;
245 	struct kiocb *iocb;
246 	struct file *file;
247 };
248 
249 /**
250  * A request to the client
251  */
252 struct fuse_req {
253 	/** This can be on either pending processing or io lists in
254 	    fuse_conn */
255 	struct list_head list;
256 
257 	/** Entry on the interrupts list  */
258 	struct list_head intr_entry;
259 
260 	/** refcount */
261 	atomic_t count;
262 
263 	/** Unique ID for the interrupt request */
264 	u64 intr_unique;
265 
266 	/*
267 	 * The following bitfields are either set once before the
268 	 * request is queued or setting/clearing them is protected by
269 	 * fuse_conn->lock
270 	 */
271 
272 	/** True if the request has reply */
273 	unsigned isreply:1;
274 
275 	/** Force sending of the request even if interrupted */
276 	unsigned force:1;
277 
278 	/** The request was aborted */
279 	unsigned aborted:1;
280 
281 	/** Request is sent in the background */
282 	unsigned background:1;
283 
284 	/** The request has been interrupted */
285 	unsigned interrupted:1;
286 
287 	/** Data is being copied to/from the request */
288 	unsigned locked:1;
289 
290 	/** Request is counted as "waiting" */
291 	unsigned waiting:1;
292 
293 	/** State of the request */
294 	enum fuse_req_state state;
295 
296 	/** The request input */
297 	struct fuse_in in;
298 
299 	/** The request output */
300 	struct fuse_out out;
301 
302 	/** Used to wake up the task waiting for completion of request*/
303 	wait_queue_head_t waitq;
304 
305 	/** Data for asynchronous requests */
306 	union {
307 		struct {
308 			union {
309 				struct fuse_release_in in;
310 				struct work_struct work;
311 			};
312 			struct path path;
313 		} release;
314 		struct fuse_init_in init_in;
315 		struct fuse_init_out init_out;
316 		struct cuse_init_in cuse_init_in;
317 		struct {
318 			struct fuse_read_in in;
319 			u64 attr_ver;
320 		} read;
321 		struct {
322 			struct fuse_write_in in;
323 			struct fuse_write_out out;
324 			struct fuse_req *next;
325 		} write;
326 		struct fuse_notify_retrieve_in retrieve_in;
327 		struct fuse_lk_in lk_in;
328 	} misc;
329 
330 	/** page vector */
331 	struct page **pages;
332 
333 	/** page-descriptor vector */
334 	struct fuse_page_desc *page_descs;
335 
336 	/** size of the 'pages' array */
337 	unsigned max_pages;
338 
339 	/** inline page vector */
340 	struct page *inline_pages[FUSE_REQ_INLINE_PAGES];
341 
342 	/** inline page-descriptor vector */
343 	struct fuse_page_desc inline_page_descs[FUSE_REQ_INLINE_PAGES];
344 
345 	/** number of pages in vector */
346 	unsigned num_pages;
347 
348 	/** File used in the request (or NULL) */
349 	struct fuse_file *ff;
350 
351 	/** Inode used in the request or NULL */
352 	struct inode *inode;
353 
354 	/** AIO control block */
355 	struct fuse_io_priv *io;
356 
357 	/** Link on fi->writepages */
358 	struct list_head writepages_entry;
359 
360 	/** Request completion callback */
361 	void (*end)(struct fuse_conn *, struct fuse_req *);
362 
363 	/** Request is stolen from fuse_file->reserved_req */
364 	struct file *stolen_file;
365 };
366 
367 /**
368  * A Fuse connection.
369  *
370  * This structure is created, when the filesystem is mounted, and is
371  * destroyed, when the client device is closed and the filesystem is
372  * unmounted.
373  */
374 struct fuse_conn {
375 	/** Lock protecting accessess to  members of this structure */
376 	spinlock_t lock;
377 
378 	/** Refcount */
379 	atomic_t count;
380 
381 	struct rcu_head rcu;
382 
383 	/** The user id for this mount */
384 	kuid_t user_id;
385 
386 	/** The group id for this mount */
387 	kgid_t group_id;
388 
389 	/** The fuse mount flags for this mount */
390 	unsigned flags;
391 
392 	/** Maximum read size */
393 	unsigned max_read;
394 
395 	/** Maximum write size */
396 	unsigned max_write;
397 
398 	/** Readers of the connection are waiting on this */
399 	wait_queue_head_t waitq;
400 
401 	/** The list of pending requests */
402 	struct list_head pending;
403 
404 	/** The list of requests being processed */
405 	struct list_head processing;
406 
407 	/** The list of requests under I/O */
408 	struct list_head io;
409 
410 	/** The next unique kernel file handle */
411 	u64 khctr;
412 
413 	/** rbtree of fuse_files waiting for poll events indexed by ph */
414 	struct rb_root polled_files;
415 
416 	/** Maximum number of outstanding background requests */
417 	unsigned max_background;
418 
419 	/** Number of background requests at which congestion starts */
420 	unsigned congestion_threshold;
421 
422 	/** Number of requests currently in the background */
423 	unsigned num_background;
424 
425 	/** Number of background requests currently queued for userspace */
426 	unsigned active_background;
427 
428 	/** The list of background requests set aside for later queuing */
429 	struct list_head bg_queue;
430 
431 	/** Pending interrupts */
432 	struct list_head interrupts;
433 
434 	/** Queue of pending forgets */
435 	struct fuse_forget_link forget_list_head;
436 	struct fuse_forget_link *forget_list_tail;
437 
438 	/** Batching of FORGET requests (positive indicates FORGET batch) */
439 	int forget_batch;
440 
441 	/** Flag indicating that INIT reply has been received. Allocating
442 	 * any fuse request will be suspended until the flag is set */
443 	int initialized;
444 
445 	/** Flag indicating if connection is blocked.  This will be
446 	    the case before the INIT reply is received, and if there
447 	    are too many outstading backgrounds requests */
448 	int blocked;
449 
450 	/** waitq for blocked connection */
451 	wait_queue_head_t blocked_waitq;
452 
453 	/** waitq for reserved requests */
454 	wait_queue_head_t reserved_req_waitq;
455 
456 	/** The next unique request id */
457 	u64 reqctr;
458 
459 	/** Connection established, cleared on umount, connection
460 	    abort and device release */
461 	unsigned connected;
462 
463 	/** Connection failed (version mismatch).  Cannot race with
464 	    setting other bitfields since it is only set once in INIT
465 	    reply, before any other request, and never cleared */
466 	unsigned conn_error:1;
467 
468 	/** Connection successful.  Only set in INIT */
469 	unsigned conn_init:1;
470 
471 	/** Do readpages asynchronously?  Only set in INIT */
472 	unsigned async_read:1;
473 
474 	/** Do not send separate SETATTR request before open(O_TRUNC)  */
475 	unsigned atomic_o_trunc:1;
476 
477 	/** Filesystem supports NFS exporting.  Only set in INIT */
478 	unsigned export_support:1;
479 
480 	/** Set if bdi is valid */
481 	unsigned bdi_initialized:1;
482 
483 	/*
484 	 * The following bitfields are only for optimization purposes
485 	 * and hence races in setting them will not cause malfunction
486 	 */
487 
488 	/** Is open/release not implemented by fs? */
489 	unsigned no_open:1;
490 
491 	/** Is fsync not implemented by fs? */
492 	unsigned no_fsync:1;
493 
494 	/** Is fsyncdir not implemented by fs? */
495 	unsigned no_fsyncdir:1;
496 
497 	/** Is flush not implemented by fs? */
498 	unsigned no_flush:1;
499 
500 	/** Is setxattr not implemented by fs? */
501 	unsigned no_setxattr:1;
502 
503 	/** Is getxattr not implemented by fs? */
504 	unsigned no_getxattr:1;
505 
506 	/** Is listxattr not implemented by fs? */
507 	unsigned no_listxattr:1;
508 
509 	/** Is removexattr not implemented by fs? */
510 	unsigned no_removexattr:1;
511 
512 	/** Are posix file locking primitives not implemented by fs? */
513 	unsigned no_lock:1;
514 
515 	/** Is access not implemented by fs? */
516 	unsigned no_access:1;
517 
518 	/** Is create not implemented by fs? */
519 	unsigned no_create:1;
520 
521 	/** Is interrupt not implemented by fs? */
522 	unsigned no_interrupt:1;
523 
524 	/** Is bmap not implemented by fs? */
525 	unsigned no_bmap:1;
526 
527 	/** Is poll not implemented by fs? */
528 	unsigned no_poll:1;
529 
530 	/** Do multi-page cached writes */
531 	unsigned big_writes:1;
532 
533 	/** Don't apply umask to creation modes */
534 	unsigned dont_mask:1;
535 
536 	/** Are BSD file locking primitives not implemented by fs? */
537 	unsigned no_flock:1;
538 
539 	/** Is fallocate not implemented by fs? */
540 	unsigned no_fallocate:1;
541 
542 	/** Use enhanced/automatic page cache invalidation. */
543 	unsigned auto_inval_data:1;
544 
545 	/** Does the filesystem support readdirplus? */
546 	unsigned do_readdirplus:1;
547 
548 	/** Does the filesystem want adaptive readdirplus? */
549 	unsigned readdirplus_auto:1;
550 
551 	/** Does the filesystem support asynchronous direct-IO submission? */
552 	unsigned async_dio:1;
553 
554 	/** The number of requests waiting for completion */
555 	atomic_t num_waiting;
556 
557 	/** Negotiated minor version */
558 	unsigned minor;
559 
560 	/** Backing dev info */
561 	struct backing_dev_info bdi;
562 
563 	/** Entry on the fuse_conn_list */
564 	struct list_head entry;
565 
566 	/** Device ID from super block */
567 	dev_t dev;
568 
569 	/** Dentries in the control filesystem */
570 	struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
571 
572 	/** number of dentries used in the above array */
573 	int ctl_ndents;
574 
575 	/** O_ASYNC requests */
576 	struct fasync_struct *fasync;
577 
578 	/** Key for lock owner ID scrambling */
579 	u32 scramble_key[4];
580 
581 	/** Reserved request for the DESTROY message */
582 	struct fuse_req *destroy_req;
583 
584 	/** Version counter for attribute changes */
585 	u64 attr_version;
586 
587 	/** Called on final put */
588 	void (*release)(struct fuse_conn *);
589 
590 	/** Super block for this connection. */
591 	struct super_block *sb;
592 
593 	/** Read/write semaphore to hold when accessing sb. */
594 	struct rw_semaphore killsb;
595 };
596 
597 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
598 {
599 	return sb->s_fs_info;
600 }
601 
602 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
603 {
604 	return get_fuse_conn_super(inode->i_sb);
605 }
606 
607 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
608 {
609 	return container_of(inode, struct fuse_inode, inode);
610 }
611 
612 static inline u64 get_node_id(struct inode *inode)
613 {
614 	return get_fuse_inode(inode)->nodeid;
615 }
616 
617 /** Device operations */
618 extern const struct file_operations fuse_dev_operations;
619 
620 extern const struct dentry_operations fuse_dentry_operations;
621 
622 /**
623  * Inode to nodeid comparison.
624  */
625 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
626 
627 /**
628  * Get a filled in inode
629  */
630 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
631 			int generation, struct fuse_attr *attr,
632 			u64 attr_valid, u64 attr_version);
633 
634 int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
635 		     struct fuse_entry_out *outarg, struct inode **inode);
636 
637 /**
638  * Send FORGET command
639  */
640 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
641 		       u64 nodeid, u64 nlookup);
642 
643 struct fuse_forget_link *fuse_alloc_forget(void);
644 
645 /* Used by READDIRPLUS */
646 void fuse_force_forget(struct file *file, u64 nodeid);
647 
648 /**
649  * Initialize READ or READDIR request
650  */
651 void fuse_read_fill(struct fuse_req *req, struct file *file,
652 		    loff_t pos, size_t count, int opcode);
653 
654 /**
655  * Send OPEN or OPENDIR request
656  */
657 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
658 
659 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
660 struct fuse_file *fuse_file_get(struct fuse_file *ff);
661 void fuse_file_free(struct fuse_file *ff);
662 void fuse_finish_open(struct inode *inode, struct file *file);
663 
664 void fuse_sync_release(struct fuse_file *ff, int flags);
665 
666 /**
667  * Send RELEASE or RELEASEDIR request
668  */
669 void fuse_release_common(struct file *file, int opcode);
670 
671 /**
672  * Send FSYNC or FSYNCDIR request
673  */
674 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
675 		      int datasync, int isdir);
676 
677 /**
678  * Notify poll wakeup
679  */
680 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
681 			    struct fuse_notify_poll_wakeup_out *outarg);
682 
683 /**
684  * Initialize file operations on a regular file
685  */
686 void fuse_init_file_inode(struct inode *inode);
687 
688 /**
689  * Initialize inode operations on regular files and special files
690  */
691 void fuse_init_common(struct inode *inode);
692 
693 /**
694  * Initialize inode and file operations on a directory
695  */
696 void fuse_init_dir(struct inode *inode);
697 
698 /**
699  * Initialize inode operations on a symlink
700  */
701 void fuse_init_symlink(struct inode *inode);
702 
703 /**
704  * Change attributes of an inode
705  */
706 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
707 			    u64 attr_valid, u64 attr_version);
708 
709 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
710 				   u64 attr_valid);
711 
712 /**
713  * Initialize the client device
714  */
715 int fuse_dev_init(void);
716 
717 /**
718  * Cleanup the client device
719  */
720 void fuse_dev_cleanup(void);
721 
722 int fuse_ctl_init(void);
723 void fuse_ctl_cleanup(void);
724 
725 /**
726  * Allocate a request
727  */
728 struct fuse_req *fuse_request_alloc(unsigned npages);
729 
730 struct fuse_req *fuse_request_alloc_nofs(unsigned npages);
731 
732 /**
733  * Free a request
734  */
735 void fuse_request_free(struct fuse_req *req);
736 
737 /**
738  * Get a request, may fail with -ENOMEM,
739  * caller should specify # elements in req->pages[] explicitly
740  */
741 struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
742 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
743 					     unsigned npages);
744 
745 /*
746  * Increment reference count on request
747  */
748 void __fuse_get_request(struct fuse_req *req);
749 
750 /**
751  * Get a request, may fail with -ENOMEM,
752  * useful for callers who doesn't use req->pages[]
753  */
754 static inline struct fuse_req *fuse_get_req_nopages(struct fuse_conn *fc)
755 {
756 	return fuse_get_req(fc, 0);
757 }
758 
759 /**
760  * Gets a requests for a file operation, always succeeds
761  */
762 struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
763 					     struct file *file);
764 
765 /**
766  * Decrement reference count of a request.  If count goes to zero free
767  * the request.
768  */
769 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
770 
771 /**
772  * Send a request (synchronous)
773  */
774 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
775 
776 /**
777  * Send a request in the background
778  */
779 void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
780 
781 void fuse_request_send_background_locked(struct fuse_conn *fc,
782 					 struct fuse_req *req);
783 
784 /* Abort all requests */
785 void fuse_abort_conn(struct fuse_conn *fc);
786 
787 /**
788  * Invalidate inode attributes
789  */
790 void fuse_invalidate_attr(struct inode *inode);
791 
792 void fuse_invalidate_entry_cache(struct dentry *entry);
793 
794 void fuse_invalidate_atime(struct inode *inode);
795 
796 /**
797  * Acquire reference to fuse_conn
798  */
799 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
800 
801 void fuse_conn_kill(struct fuse_conn *fc);
802 
803 /**
804  * Initialize fuse_conn
805  */
806 void fuse_conn_init(struct fuse_conn *fc);
807 
808 /**
809  * Release reference to fuse_conn
810  */
811 void fuse_conn_put(struct fuse_conn *fc);
812 
813 /**
814  * Add connection to control filesystem
815  */
816 int fuse_ctl_add_conn(struct fuse_conn *fc);
817 
818 /**
819  * Remove connection from control filesystem
820  */
821 void fuse_ctl_remove_conn(struct fuse_conn *fc);
822 
823 /**
824  * Is file type valid?
825  */
826 int fuse_valid_type(int m);
827 
828 /**
829  * Is current process allowed to perform filesystem operation?
830  */
831 int fuse_allow_current_process(struct fuse_conn *fc);
832 
833 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
834 
835 int fuse_update_attributes(struct inode *inode, struct kstat *stat,
836 			   struct file *file, bool *refreshed);
837 
838 void fuse_flush_writepages(struct inode *inode);
839 
840 void fuse_set_nowrite(struct inode *inode);
841 void fuse_release_nowrite(struct inode *inode);
842 
843 u64 fuse_get_attr_version(struct fuse_conn *fc);
844 
845 /**
846  * File-system tells the kernel to invalidate cache for the given node id.
847  */
848 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
849 			     loff_t offset, loff_t len);
850 
851 /**
852  * File-system tells the kernel to invalidate parent attributes and
853  * the dentry matching parent/name.
854  *
855  * If the child_nodeid is non-zero and:
856  *    - matches the inode number for the dentry matching parent/name,
857  *    - is not a mount point
858  *    - is a file or oan empty directory
859  * then the dentry is unhashed (d_delete()).
860  */
861 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
862 			     u64 child_nodeid, struct qstr *name);
863 
864 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
865 		 bool isdir);
866 ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
867 		       unsigned long nr_segs, size_t count, loff_t *ppos,
868 		       int write);
869 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
870 		   unsigned int flags);
871 long fuse_ioctl_common(struct file *file, unsigned int cmd,
872 		       unsigned long arg, unsigned int flags);
873 unsigned fuse_file_poll(struct file *file, poll_table *wait);
874 int fuse_dev_release(struct inode *inode, struct file *file);
875 
876 void fuse_write_update_size(struct inode *inode, loff_t pos);
877 
878 int fuse_do_setattr(struct inode *inode, struct iattr *attr,
879 		    struct file *file);
880 
881 #endif /* _FS_FUSE_I_H */
882