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 #ifndef pr_fmt
13 # define pr_fmt(fmt) "fuse: " fmt
14 #endif
15
16 #include <linux/fuse.h>
17 #include <linux/fs.h>
18 #include <linux/mount.h>
19 #include <linux/wait.h>
20 #include <linux/list.h>
21 #include <linux/spinlock.h>
22 #include <linux/mm.h>
23 #include <linux/backing-dev.h>
24 #include <linux/mutex.h>
25 #include <linux/rwsem.h>
26 #include <linux/rbtree.h>
27 #include <linux/poll.h>
28 #include <linux/workqueue.h>
29 #include <linux/kref.h>
30 #include <linux/xattr.h>
31 #include <linux/pid_namespace.h>
32 #include <linux/refcount.h>
33 #include <linux/user_namespace.h>
34
35 /** Default max number of pages that can be used in a single read request */
36 #define FUSE_DEFAULT_MAX_PAGES_PER_REQ 32
37
38 /** Maximum of max_pages received in init_out */
39 #define FUSE_MAX_MAX_PAGES 256
40
41 /** Bias for fi->writectr, meaning new writepages must not be sent */
42 #define FUSE_NOWRITE INT_MIN
43
44 /** It could be as large as PATH_MAX, but would that have any uses? */
45 #define FUSE_NAME_MAX 1024
46
47 /** Number of dentries for each connection in the control filesystem */
48 #define FUSE_CTL_NUM_DENTRIES 5
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 /* Which attributes are invalid */
85 u32 inval_mask;
86
87 /** The sticky bit in inode->i_mode may have been removed, so
88 preserve the original mode */
89 umode_t orig_i_mode;
90
91 /** 64 bit inode number */
92 u64 orig_ino;
93
94 /** Version of last attribute change */
95 u64 attr_version;
96
97 union {
98 /* Write related fields (regular file only) */
99 struct {
100 /* Files usable in writepage. Protected by fi->lock */
101 struct list_head write_files;
102
103 /* Writepages pending on truncate or fsync */
104 struct list_head queued_writes;
105
106 /* Number of sent writes, a negative bias
107 * (FUSE_NOWRITE) means more writes are blocked */
108 int writectr;
109
110 /* Waitq for writepage completion */
111 wait_queue_head_t page_waitq;
112
113 /* List of writepage requestst (pending or sent) */
114 struct list_head writepages;
115 };
116
117 /* readdir cache (directory only) */
118 struct {
119 /* true if fully cached */
120 bool cached;
121
122 /* size of cache */
123 loff_t size;
124
125 /* position at end of cache (position of next entry) */
126 loff_t pos;
127
128 /* version of the cache */
129 u64 version;
130
131 /* modification time of directory when cache was
132 * started */
133 struct timespec64 mtime;
134
135 /* iversion of directory when cache was started */
136 u64 iversion;
137
138 /* protects above fields */
139 spinlock_t lock;
140 } rdc;
141 };
142
143 /** Miscellaneous bits describing inode state */
144 unsigned long state;
145
146 /** Lock for serializing lookup and readdir for back compatibility*/
147 struct mutex mutex;
148
149 /** Lock to protect write related fields */
150 spinlock_t lock;
151 };
152
153 /** FUSE inode state bits */
154 enum {
155 /** Advise readdirplus */
156 FUSE_I_ADVISE_RDPLUS,
157 /** Initialized with readdirplus */
158 FUSE_I_INIT_RDPLUS,
159 /** An operation changing file size is in progress */
160 FUSE_I_SIZE_UNSTABLE,
161 };
162
163 struct fuse_conn;
164 struct fuse_release_args;
165
166 /** FUSE specific file data */
167 struct fuse_file {
168 /** Fuse connection for this file */
169 struct fuse_conn *fc;
170
171 /* Argument space reserved for release */
172 struct fuse_release_args *release_args;
173
174 /** Kernel file handle guaranteed to be unique */
175 u64 kh;
176
177 /** File handle used by userspace */
178 u64 fh;
179
180 /** Node id of this file */
181 u64 nodeid;
182
183 /** Refcount */
184 refcount_t count;
185
186 /** FOPEN_* flags returned by open */
187 u32 open_flags;
188
189 /** Entry on inode's write_files list */
190 struct list_head write_entry;
191
192 /* Readdir related */
193 struct {
194 /*
195 * Protects below fields against (crazy) parallel readdir on
196 * same open file. Uncontended in the normal case.
197 */
198 struct mutex lock;
199
200 /* Dir stream position */
201 loff_t pos;
202
203 /* Offset in cache */
204 loff_t cache_off;
205
206 /* Version of cache we are reading */
207 u64 version;
208
209 } readdir;
210
211 /** RB node to be linked on fuse_conn->polled_files */
212 struct rb_node polled_node;
213
214 /** Wait queue head for poll */
215 wait_queue_head_t poll_wait;
216
217 /** Has flock been performed on this file? */
218 bool flock:1;
219 };
220
221 /** One input argument of a request */
222 struct fuse_in_arg {
223 unsigned size;
224 const void *value;
225 };
226
227 /** One output argument of a request */
228 struct fuse_arg {
229 unsigned size;
230 void *value;
231 };
232
233 /** FUSE page descriptor */
234 struct fuse_page_desc {
235 unsigned int length;
236 unsigned int offset;
237 };
238
239 struct fuse_args {
240 uint64_t nodeid;
241 uint32_t opcode;
242 unsigned short in_numargs;
243 unsigned short out_numargs;
244 bool force:1;
245 bool noreply:1;
246 bool nocreds:1;
247 bool in_pages:1;
248 bool out_pages:1;
249 bool out_argvar:1;
250 bool page_zeroing:1;
251 bool page_replace:1;
252 struct fuse_in_arg in_args[3];
253 struct fuse_arg out_args[2];
254 void (*end)(struct fuse_conn *fc, struct fuse_args *args, int error);
255 };
256
257 struct fuse_args_pages {
258 struct fuse_args args;
259 struct page **pages;
260 struct fuse_page_desc *descs;
261 unsigned int num_pages;
262 };
263
264 #define FUSE_ARGS(args) struct fuse_args args = {}
265
266 /** The request IO state (for asynchronous processing) */
267 struct fuse_io_priv {
268 struct kref refcnt;
269 int async;
270 spinlock_t lock;
271 unsigned reqs;
272 ssize_t bytes;
273 size_t size;
274 __u64 offset;
275 bool write;
276 bool should_dirty;
277 int err;
278 struct kiocb *iocb;
279 struct completion *done;
280 bool blocking;
281 };
282
283 #define FUSE_IO_PRIV_SYNC(i) \
284 { \
285 .refcnt = KREF_INIT(1), \
286 .async = 0, \
287 .iocb = i, \
288 }
289
290 /**
291 * Request flags
292 *
293 * FR_ISREPLY: set if the request has reply
294 * FR_FORCE: force sending of the request even if interrupted
295 * FR_BACKGROUND: request is sent in the background
296 * FR_WAITING: request is counted as "waiting"
297 * FR_ABORTED: the request was aborted
298 * FR_INTERRUPTED: the request has been interrupted
299 * FR_LOCKED: data is being copied to/from the request
300 * FR_PENDING: request is not yet in userspace
301 * FR_SENT: request is in userspace, waiting for an answer
302 * FR_FINISHED: request is finished
303 * FR_PRIVATE: request is on private list
304 * FR_ASYNC: request is asynchronous
305 */
306 enum fuse_req_flag {
307 FR_ISREPLY,
308 FR_FORCE,
309 FR_BACKGROUND,
310 FR_WAITING,
311 FR_ABORTED,
312 FR_INTERRUPTED,
313 FR_LOCKED,
314 FR_PENDING,
315 FR_SENT,
316 FR_FINISHED,
317 FR_PRIVATE,
318 FR_ASYNC,
319 };
320
321 /**
322 * A request to the client
323 *
324 * .waitq.lock protects the following fields:
325 * - FR_ABORTED
326 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
327 */
328 struct fuse_req {
329 /** This can be on either pending processing or io lists in
330 fuse_conn */
331 struct list_head list;
332
333 /** Entry on the interrupts list */
334 struct list_head intr_entry;
335
336 /* Input/output arguments */
337 struct fuse_args *args;
338
339 /** refcount */
340 refcount_t count;
341
342 /* Request flags, updated with test/set/clear_bit() */
343 unsigned long flags;
344
345 /* The request input header */
346 struct {
347 struct fuse_in_header h;
348 } in;
349
350 /* The request output header */
351 struct {
352 struct fuse_out_header h;
353 } out;
354
355 /** Used to wake up the task waiting for completion of request*/
356 wait_queue_head_t waitq;
357
358 #if IS_ENABLED(CONFIG_VIRTIO_FS)
359 /** virtio-fs's physically contiguous buffer for in and out args */
360 void *argbuf;
361 #endif
362 };
363
364 struct fuse_iqueue;
365
366 /**
367 * Input queue callbacks
368 *
369 * Input queue signalling is device-specific. For example, the /dev/fuse file
370 * uses fiq->waitq and fasync to wake processes that are waiting on queue
371 * readiness. These callbacks allow other device types to respond to input
372 * queue activity.
373 */
374 struct fuse_iqueue_ops {
375 /**
376 * Signal that a forget has been queued
377 */
378 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
379 __releases(fiq->lock);
380
381 /**
382 * Signal that an INTERRUPT request has been queued
383 */
384 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
385 __releases(fiq->lock);
386
387 /**
388 * Signal that a request has been queued
389 */
390 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
391 __releases(fiq->lock);
392
393 /**
394 * Clean up when fuse_iqueue is destroyed
395 */
396 void (*release)(struct fuse_iqueue *fiq);
397 };
398
399 /** /dev/fuse input queue operations */
400 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
401
402 struct fuse_iqueue {
403 /** Connection established */
404 unsigned connected;
405
406 /** Lock protecting accesses to members of this structure */
407 spinlock_t lock;
408
409 /** Readers of the connection are waiting on this */
410 wait_queue_head_t waitq;
411
412 /** The next unique request id */
413 u64 reqctr;
414
415 /** The list of pending requests */
416 struct list_head pending;
417
418 /** Pending interrupts */
419 struct list_head interrupts;
420
421 /** Queue of pending forgets */
422 struct fuse_forget_link forget_list_head;
423 struct fuse_forget_link *forget_list_tail;
424
425 /** Batching of FORGET requests (positive indicates FORGET batch) */
426 int forget_batch;
427
428 /** O_ASYNC requests */
429 struct fasync_struct *fasync;
430
431 /** Device-specific callbacks */
432 const struct fuse_iqueue_ops *ops;
433
434 /** Device-specific state */
435 void *priv;
436 };
437
438 #define FUSE_PQ_HASH_BITS 8
439 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
440
441 struct fuse_pqueue {
442 /** Connection established */
443 unsigned connected;
444
445 /** Lock protecting accessess to members of this structure */
446 spinlock_t lock;
447
448 /** Hash table of requests being processed */
449 struct list_head *processing;
450
451 /** The list of requests under I/O */
452 struct list_head io;
453 };
454
455 /**
456 * Fuse device instance
457 */
458 struct fuse_dev {
459 /** Fuse connection for this device */
460 struct fuse_conn *fc;
461
462 /** Processing queue */
463 struct fuse_pqueue pq;
464
465 /** list entry on fc->devices */
466 struct list_head entry;
467 };
468
469 struct fuse_fs_context {
470 int fd;
471 unsigned int rootmode;
472 kuid_t user_id;
473 kgid_t group_id;
474 bool is_bdev:1;
475 bool fd_present:1;
476 bool rootmode_present:1;
477 bool user_id_present:1;
478 bool group_id_present:1;
479 bool default_permissions:1;
480 bool allow_other:1;
481 bool destroy:1;
482 bool no_control:1;
483 bool no_force_umount:1;
484 bool no_mount_options:1;
485 unsigned int max_read;
486 unsigned int blksize;
487 const char *subtype;
488
489 /* fuse_dev pointer to fill in, should contain NULL on entry */
490 void **fudptr;
491 };
492
493 /**
494 * A Fuse connection.
495 *
496 * This structure is created, when the filesystem is mounted, and is
497 * destroyed, when the client device is closed and the filesystem is
498 * unmounted.
499 */
500 struct fuse_conn {
501 /** Lock protecting accessess to members of this structure */
502 spinlock_t lock;
503
504 /** Refcount */
505 refcount_t count;
506
507 /** Number of fuse_dev's */
508 atomic_t dev_count;
509
510 struct rcu_head rcu;
511
512 /** The user id for this mount */
513 kuid_t user_id;
514
515 /** The group id for this mount */
516 kgid_t group_id;
517
518 /** The pid namespace for this mount */
519 struct pid_namespace *pid_ns;
520
521 /** The user namespace for this mount */
522 struct user_namespace *user_ns;
523
524 /** Maximum read size */
525 unsigned max_read;
526
527 /** Maximum write size */
528 unsigned max_write;
529
530 /** Maxmum number of pages that can be used in a single request */
531 unsigned int max_pages;
532
533 /** Input queue */
534 struct fuse_iqueue iq;
535
536 /** The next unique kernel file handle */
537 atomic64_t khctr;
538
539 /** rbtree of fuse_files waiting for poll events indexed by ph */
540 struct rb_root polled_files;
541
542 /** Maximum number of outstanding background requests */
543 unsigned max_background;
544
545 /** Number of background requests at which congestion starts */
546 unsigned congestion_threshold;
547
548 /** Number of requests currently in the background */
549 unsigned num_background;
550
551 /** Number of background requests currently queued for userspace */
552 unsigned active_background;
553
554 /** The list of background requests set aside for later queuing */
555 struct list_head bg_queue;
556
557 /** Protects: max_background, congestion_threshold, num_background,
558 * active_background, bg_queue, blocked */
559 spinlock_t bg_lock;
560
561 /** Flag indicating that INIT reply has been received. Allocating
562 * any fuse request will be suspended until the flag is set */
563 int initialized;
564
565 /** Flag indicating if connection is blocked. This will be
566 the case before the INIT reply is received, and if there
567 are too many outstading backgrounds requests */
568 int blocked;
569
570 /** waitq for blocked connection */
571 wait_queue_head_t blocked_waitq;
572
573 /** Connection established, cleared on umount, connection
574 abort and device release */
575 unsigned connected;
576
577 /** Connection aborted via sysfs */
578 bool aborted;
579
580 /** Connection failed (version mismatch). Cannot race with
581 setting other bitfields since it is only set once in INIT
582 reply, before any other request, and never cleared */
583 unsigned conn_error:1;
584
585 /** Connection successful. Only set in INIT */
586 unsigned conn_init:1;
587
588 /** Do readpages asynchronously? Only set in INIT */
589 unsigned async_read:1;
590
591 /** Return an unique read error after abort. Only set in INIT */
592 unsigned abort_err:1;
593
594 /** Do not send separate SETATTR request before open(O_TRUNC) */
595 unsigned atomic_o_trunc:1;
596
597 /** Filesystem supports NFS exporting. Only set in INIT */
598 unsigned export_support:1;
599
600 /** write-back cache policy (default is write-through) */
601 unsigned writeback_cache:1;
602
603 /** allow parallel lookups and readdir (default is serialized) */
604 unsigned parallel_dirops:1;
605
606 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
607 unsigned handle_killpriv:1;
608
609 /** cache READLINK responses in page cache */
610 unsigned cache_symlinks:1;
611
612 /*
613 * The following bitfields are only for optimization purposes
614 * and hence races in setting them will not cause malfunction
615 */
616
617 /** Is open/release not implemented by fs? */
618 unsigned no_open:1;
619
620 /** Is opendir/releasedir not implemented by fs? */
621 unsigned no_opendir:1;
622
623 /** Is fsync not implemented by fs? */
624 unsigned no_fsync:1;
625
626 /** Is fsyncdir not implemented by fs? */
627 unsigned no_fsyncdir:1;
628
629 /** Is flush not implemented by fs? */
630 unsigned no_flush:1;
631
632 /** Is setxattr not implemented by fs? */
633 unsigned no_setxattr:1;
634
635 /** Is getxattr not implemented by fs? */
636 unsigned no_getxattr:1;
637
638 /** Is listxattr not implemented by fs? */
639 unsigned no_listxattr:1;
640
641 /** Is removexattr not implemented by fs? */
642 unsigned no_removexattr:1;
643
644 /** Are posix file locking primitives not implemented by fs? */
645 unsigned no_lock:1;
646
647 /** Is access not implemented by fs? */
648 unsigned no_access:1;
649
650 /** Is create not implemented by fs? */
651 unsigned no_create:1;
652
653 /** Is interrupt not implemented by fs? */
654 unsigned no_interrupt:1;
655
656 /** Is bmap not implemented by fs? */
657 unsigned no_bmap:1;
658
659 /** Is poll not implemented by fs? */
660 unsigned no_poll:1;
661
662 /** Do multi-page cached writes */
663 unsigned big_writes:1;
664
665 /** Don't apply umask to creation modes */
666 unsigned dont_mask:1;
667
668 /** Are BSD file locking primitives not implemented by fs? */
669 unsigned no_flock:1;
670
671 /** Is fallocate not implemented by fs? */
672 unsigned no_fallocate:1;
673
674 /** Is rename with flags implemented by fs? */
675 unsigned no_rename2:1;
676
677 /** Use enhanced/automatic page cache invalidation. */
678 unsigned auto_inval_data:1;
679
680 /** Filesystem is fully reponsible for page cache invalidation. */
681 unsigned explicit_inval_data:1;
682
683 /** Does the filesystem support readdirplus? */
684 unsigned do_readdirplus:1;
685
686 /** Does the filesystem want adaptive readdirplus? */
687 unsigned readdirplus_auto:1;
688
689 /** Does the filesystem support asynchronous direct-IO submission? */
690 unsigned async_dio:1;
691
692 /** Is lseek not implemented by fs? */
693 unsigned no_lseek:1;
694
695 /** Does the filesystem support posix acls? */
696 unsigned posix_acl:1;
697
698 /** Check permissions based on the file mode or not? */
699 unsigned default_permissions:1;
700
701 /** Allow other than the mounter user to access the filesystem ? */
702 unsigned allow_other:1;
703
704 /** Does the filesystem support copy_file_range? */
705 unsigned no_copy_file_range:1;
706
707 /* Send DESTROY request */
708 unsigned int destroy:1;
709
710 /* Delete dentries that have gone stale */
711 unsigned int delete_stale:1;
712
713 /** Do not create entry in fusectl fs */
714 unsigned int no_control:1;
715
716 /** Do not allow MNT_FORCE umount */
717 unsigned int no_force_umount:1;
718
719 /* Do not show mount options */
720 unsigned int no_mount_options:1;
721
722 /** The number of requests waiting for completion */
723 atomic_t num_waiting;
724
725 /** Negotiated minor version */
726 unsigned minor;
727
728 /** Entry on the fuse_conn_list */
729 struct list_head entry;
730
731 /** Device ID from super block */
732 dev_t dev;
733
734 /** Dentries in the control filesystem */
735 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
736
737 /** number of dentries used in the above array */
738 int ctl_ndents;
739
740 /** Key for lock owner ID scrambling */
741 u32 scramble_key[4];
742
743 /** Version counter for attribute changes */
744 atomic64_t attr_version;
745
746 /** Called on final put */
747 void (*release)(struct fuse_conn *);
748
749 /** Super block for this connection. */
750 struct super_block *sb;
751
752 /** Read/write semaphore to hold when accessing sb. */
753 struct rw_semaphore killsb;
754
755 /** List of device instances belonging to this connection */
756 struct list_head devices;
757 };
758
759 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
760 {
761 return sb->s_fs_info;
762 }
763
764 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
765 {
766 return get_fuse_conn_super(inode->i_sb);
767 }
768
769 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
770 {
771 return container_of(inode, struct fuse_inode, inode);
772 }
773
774 static inline u64 get_node_id(struct inode *inode)
775 {
776 return get_fuse_inode(inode)->nodeid;
777 }
778
779 static inline int invalid_nodeid(u64 nodeid)
780 {
781 return !nodeid || nodeid == FUSE_ROOT_ID;
782 }
783
784 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
785 {
786 return atomic64_read(&fc->attr_version);
787 }
788
789 /** Device operations */
790 extern const struct file_operations fuse_dev_operations;
791
792 extern const struct dentry_operations fuse_dentry_operations;
793 extern const struct dentry_operations fuse_root_dentry_operations;
794
795 /**
796 * Inode to nodeid comparison.
797 */
798 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
799
800 /**
801 * Get a filled in inode
802 */
803 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
804 int generation, struct fuse_attr *attr,
805 u64 attr_valid, u64 attr_version);
806
807 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
808 struct fuse_entry_out *outarg, struct inode **inode);
809
810 /**
811 * Send FORGET command
812 */
813 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
814 u64 nodeid, u64 nlookup);
815
816 struct fuse_forget_link *fuse_alloc_forget(void);
817
818 struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
819 unsigned int max,
820 unsigned int *countp);
821
822 /*
823 * Initialize READ or READDIR request
824 */
825 struct fuse_io_args {
826 union {
827 struct {
828 struct fuse_read_in in;
829 u64 attr_ver;
830 } read;
831 struct {
832 struct fuse_write_in in;
833 struct fuse_write_out out;
834 } write;
835 };
836 struct fuse_args_pages ap;
837 struct fuse_io_priv *io;
838 struct fuse_file *ff;
839 };
840
841 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
842 size_t count, int opcode);
843
844
845 /**
846 * Send OPEN or OPENDIR request
847 */
848 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
849
850 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
851 void fuse_file_free(struct fuse_file *ff);
852 void fuse_finish_open(struct inode *inode, struct file *file);
853
854 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags);
855
856 /**
857 * Send RELEASE or RELEASEDIR request
858 */
859 void fuse_release_common(struct file *file, bool isdir);
860
861 /**
862 * Send FSYNC or FSYNCDIR request
863 */
864 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
865 int datasync, int opcode);
866
867 /**
868 * Notify poll wakeup
869 */
870 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
871 struct fuse_notify_poll_wakeup_out *outarg);
872
873 /**
874 * Initialize file operations on a regular file
875 */
876 void fuse_init_file_inode(struct inode *inode);
877
878 /**
879 * Initialize inode operations on regular files and special files
880 */
881 void fuse_init_common(struct inode *inode);
882
883 /**
884 * Initialize inode and file operations on a directory
885 */
886 void fuse_init_dir(struct inode *inode);
887
888 /**
889 * Initialize inode operations on a symlink
890 */
891 void fuse_init_symlink(struct inode *inode);
892
893 /**
894 * Change attributes of an inode
895 */
896 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
897 u64 attr_valid, u64 attr_version);
898
899 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
900 u64 attr_valid);
901
902 /**
903 * Initialize the client device
904 */
905 int fuse_dev_init(void);
906
907 /**
908 * Cleanup the client device
909 */
910 void fuse_dev_cleanup(void);
911
912 int fuse_ctl_init(void);
913 void __exit fuse_ctl_cleanup(void);
914
915 /**
916 * Simple request sending that does request allocation and freeing
917 */
918 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
919 int fuse_simple_background(struct fuse_conn *fc, struct fuse_args *args,
920 gfp_t gfp_flags);
921
922 /**
923 * End a finished request
924 */
925 void fuse_request_end(struct fuse_conn *fc, struct fuse_req *req);
926
927 /* Abort all requests */
928 void fuse_abort_conn(struct fuse_conn *fc);
929 void fuse_wait_aborted(struct fuse_conn *fc);
930
931 /**
932 * Invalidate inode attributes
933 */
934 void fuse_invalidate_attr(struct inode *inode);
935
936 void fuse_invalidate_entry_cache(struct dentry *entry);
937
938 void fuse_invalidate_atime(struct inode *inode);
939
940 u64 entry_attr_timeout(struct fuse_entry_out *o);
941 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
942
943 /**
944 * Acquire reference to fuse_conn
945 */
946 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
947
948 /**
949 * Initialize fuse_conn
950 */
951 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns,
952 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
953
954 /**
955 * Release reference to fuse_conn
956 */
957 void fuse_conn_put(struct fuse_conn *fc);
958
959 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
960 struct fuse_dev *fuse_dev_alloc(void);
961 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
962 void fuse_dev_free(struct fuse_dev *fud);
963 void fuse_send_init(struct fuse_conn *fc);
964
965 /**
966 * Fill in superblock and initialize fuse connection
967 * @sb: partially-initialized superblock to fill in
968 * @ctx: mount context
969 */
970 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
971
972 /**
973 * Disassociate fuse connection from superblock and kill the superblock
974 *
975 * Calls kill_anon_super(), do not use with bdev mounts.
976 */
977 void fuse_kill_sb_anon(struct super_block *sb);
978
979 /**
980 * Add connection to control filesystem
981 */
982 int fuse_ctl_add_conn(struct fuse_conn *fc);
983
984 /**
985 * Remove connection from control filesystem
986 */
987 void fuse_ctl_remove_conn(struct fuse_conn *fc);
988
989 /**
990 * Is file type valid?
991 */
992 int fuse_valid_type(int m);
993
994 bool fuse_invalid_attr(struct fuse_attr *attr);
995
996 /**
997 * Is current process allowed to perform filesystem operation?
998 */
999 int fuse_allow_current_process(struct fuse_conn *fc);
1000
1001 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1002
1003 void fuse_update_ctime(struct inode *inode);
1004
1005 int fuse_update_attributes(struct inode *inode, struct file *file);
1006
1007 void fuse_flush_writepages(struct inode *inode);
1008
1009 void fuse_set_nowrite(struct inode *inode);
1010 void fuse_release_nowrite(struct inode *inode);
1011
1012 /**
1013 * File-system tells the kernel to invalidate cache for the given node id.
1014 */
1015 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
1016 loff_t offset, loff_t len);
1017
1018 /**
1019 * File-system tells the kernel to invalidate parent attributes and
1020 * the dentry matching parent/name.
1021 *
1022 * If the child_nodeid is non-zero and:
1023 * - matches the inode number for the dentry matching parent/name,
1024 * - is not a mount point
1025 * - is a file or oan empty directory
1026 * then the dentry is unhashed (d_delete()).
1027 */
1028 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
1029 u64 child_nodeid, struct qstr *name);
1030
1031 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
1032 bool isdir);
1033
1034 /**
1035 * fuse_direct_io() flags
1036 */
1037
1038 /** If set, it is WRITE; otherwise - READ */
1039 #define FUSE_DIO_WRITE (1 << 0)
1040
1041 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1042 #define FUSE_DIO_CUSE (1 << 1)
1043
1044 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1045 loff_t *ppos, int flags);
1046 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1047 unsigned int flags);
1048 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1049 unsigned long arg, unsigned int flags);
1050 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1051 int fuse_dev_release(struct inode *inode, struct file *file);
1052
1053 bool fuse_write_update_size(struct inode *inode, loff_t pos);
1054
1055 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1056 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1057
1058 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1059 struct file *file);
1060
1061 void fuse_set_initialized(struct fuse_conn *fc);
1062
1063 void fuse_unlock_inode(struct inode *inode, bool locked);
1064 bool fuse_lock_inode(struct inode *inode);
1065
1066 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1067 size_t size, int flags);
1068 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1069 size_t size);
1070 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1071 int fuse_removexattr(struct inode *inode, const char *name);
1072 extern const struct xattr_handler *fuse_xattr_handlers[];
1073 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1074 extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1075
1076 struct posix_acl;
1077 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
1078 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
1079
1080
1081 /* readdir.c */
1082 int fuse_readdir(struct file *file, struct dir_context *ctx);
1083
1084 /**
1085 * Return the number of bytes in an arguments list
1086 */
1087 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1088
1089 /**
1090 * Get the next unique ID for a request
1091 */
1092 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1093 void fuse_free_conn(struct fuse_conn *fc);
1094
1095 #endif /* _FS_FUSE_I_H */