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 */
305 enum fuse_req_flag {
306 FR_ISREPLY,
307 FR_FORCE,
308 FR_BACKGROUND,
309 FR_WAITING,
310 FR_ABORTED,
311 FR_INTERRUPTED,
312 FR_LOCKED,
313 FR_PENDING,
314 FR_SENT,
315 FR_FINISHED,
316 FR_PRIVATE,
317 };
318
319 /**
320 * A request to the client
321 *
322 * .waitq.lock protects the following fields:
323 * - FR_ABORTED
324 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
325 */
326 struct fuse_req {
327 /** This can be on either pending processing or io lists in
328 fuse_conn */
329 struct list_head list;
330
331 /** Entry on the interrupts list */
332 struct list_head intr_entry;
333
334 /* Input/output arguments */
335 struct fuse_args *args;
336
337 /** refcount */
338 refcount_t count;
339
340 /* Request flags, updated with test/set/clear_bit() */
341 unsigned long flags;
342
343 /* The request input header */
344 struct {
345 struct fuse_in_header h;
346 } in;
347
348 /* The request output header */
349 struct {
350 struct fuse_out_header h;
351 } out;
352
353 /** Used to wake up the task waiting for completion of request*/
354 wait_queue_head_t waitq;
355
356 #if IS_ENABLED(CONFIG_VIRTIO_FS)
357 /** virtio-fs's physically contiguous buffer for in and out args */
358 void *argbuf;
359 #endif
360 };
361
362 struct fuse_iqueue;
363
364 /**
365 * Input queue callbacks
366 *
367 * Input queue signalling is device-specific. For example, the /dev/fuse file
368 * uses fiq->waitq and fasync to wake processes that are waiting on queue
369 * readiness. These callbacks allow other device types to respond to input
370 * queue activity.
371 */
372 struct fuse_iqueue_ops {
373 /**
374 * Signal that a forget has been queued
375 */
376 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
377 __releases(fiq->lock);
378
379 /**
380 * Signal that an INTERRUPT request has been queued
381 */
382 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
383 __releases(fiq->lock);
384
385 /**
386 * Signal that a request has been queued
387 */
388 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
389 __releases(fiq->lock);
390
391 /**
392 * Clean up when fuse_iqueue is destroyed
393 */
394 void (*release)(struct fuse_iqueue *fiq);
395 };
396
397 /** /dev/fuse input queue operations */
398 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
399
400 struct fuse_iqueue {
401 /** Connection established */
402 unsigned connected;
403
404 /** Lock protecting accesses to members of this structure */
405 spinlock_t lock;
406
407 /** Readers of the connection are waiting on this */
408 wait_queue_head_t waitq;
409
410 /** The next unique request id */
411 u64 reqctr;
412
413 /** The list of pending requests */
414 struct list_head pending;
415
416 /** Pending interrupts */
417 struct list_head interrupts;
418
419 /** Queue of pending forgets */
420 struct fuse_forget_link forget_list_head;
421 struct fuse_forget_link *forget_list_tail;
422
423 /** Batching of FORGET requests (positive indicates FORGET batch) */
424 int forget_batch;
425
426 /** O_ASYNC requests */
427 struct fasync_struct *fasync;
428
429 /** Device-specific callbacks */
430 const struct fuse_iqueue_ops *ops;
431
432 /** Device-specific state */
433 void *priv;
434 };
435
436 #define FUSE_PQ_HASH_BITS 8
437 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
438
439 struct fuse_pqueue {
440 /** Connection established */
441 unsigned connected;
442
443 /** Lock protecting accessess to members of this structure */
444 spinlock_t lock;
445
446 /** Hash table of requests being processed */
447 struct list_head *processing;
448
449 /** The list of requests under I/O */
450 struct list_head io;
451 };
452
453 /**
454 * Fuse device instance
455 */
456 struct fuse_dev {
457 /** Fuse connection for this device */
458 struct fuse_conn *fc;
459
460 /** Processing queue */
461 struct fuse_pqueue pq;
462
463 /** list entry on fc->devices */
464 struct list_head entry;
465 };
466
467 struct fuse_fs_context {
468 int fd;
469 unsigned int rootmode;
470 kuid_t user_id;
471 kgid_t group_id;
472 bool is_bdev:1;
473 bool fd_present:1;
474 bool rootmode_present:1;
475 bool user_id_present:1;
476 bool group_id_present:1;
477 bool default_permissions:1;
478 bool allow_other:1;
479 bool destroy:1;
480 bool no_control:1;
481 bool no_force_umount:1;
482 bool no_mount_options:1;
483 unsigned int max_read;
484 unsigned int blksize;
485 const char *subtype;
486
487 /* fuse_dev pointer to fill in, should contain NULL on entry */
488 void **fudptr;
489 };
490
491 /**
492 * A Fuse connection.
493 *
494 * This structure is created, when the filesystem is mounted, and is
495 * destroyed, when the client device is closed and the filesystem is
496 * unmounted.
497 */
498 struct fuse_conn {
499 /** Lock protecting accessess to members of this structure */
500 spinlock_t lock;
501
502 /** Refcount */
503 refcount_t count;
504
505 /** Number of fuse_dev's */
506 atomic_t dev_count;
507
508 struct rcu_head rcu;
509
510 /** The user id for this mount */
511 kuid_t user_id;
512
513 /** The group id for this mount */
514 kgid_t group_id;
515
516 /** The pid namespace for this mount */
517 struct pid_namespace *pid_ns;
518
519 /** The user namespace for this mount */
520 struct user_namespace *user_ns;
521
522 /** Maximum read size */
523 unsigned max_read;
524
525 /** Maximum write size */
526 unsigned max_write;
527
528 /** Maxmum number of pages that can be used in a single request */
529 unsigned int max_pages;
530
531 /** Input queue */
532 struct fuse_iqueue iq;
533
534 /** The next unique kernel file handle */
535 atomic64_t khctr;
536
537 /** rbtree of fuse_files waiting for poll events indexed by ph */
538 struct rb_root polled_files;
539
540 /** Maximum number of outstanding background requests */
541 unsigned max_background;
542
543 /** Number of background requests at which congestion starts */
544 unsigned congestion_threshold;
545
546 /** Number of requests currently in the background */
547 unsigned num_background;
548
549 /** Number of background requests currently queued for userspace */
550 unsigned active_background;
551
552 /** The list of background requests set aside for later queuing */
553 struct list_head bg_queue;
554
555 /** Protects: max_background, congestion_threshold, num_background,
556 * active_background, bg_queue, blocked */
557 spinlock_t bg_lock;
558
559 /** Flag indicating that INIT reply has been received. Allocating
560 * any fuse request will be suspended until the flag is set */
561 int initialized;
562
563 /** Flag indicating if connection is blocked. This will be
564 the case before the INIT reply is received, and if there
565 are too many outstading backgrounds requests */
566 int blocked;
567
568 /** waitq for blocked connection */
569 wait_queue_head_t blocked_waitq;
570
571 /** Connection established, cleared on umount, connection
572 abort and device release */
573 unsigned connected;
574
575 /** Connection aborted via sysfs */
576 bool aborted;
577
578 /** Connection failed (version mismatch). Cannot race with
579 setting other bitfields since it is only set once in INIT
580 reply, before any other request, and never cleared */
581 unsigned conn_error:1;
582
583 /** Connection successful. Only set in INIT */
584 unsigned conn_init:1;
585
586 /** Do readpages asynchronously? Only set in INIT */
587 unsigned async_read:1;
588
589 /** Return an unique read error after abort. Only set in INIT */
590 unsigned abort_err:1;
591
592 /** Do not send separate SETATTR request before open(O_TRUNC) */
593 unsigned atomic_o_trunc:1;
594
595 /** Filesystem supports NFS exporting. Only set in INIT */
596 unsigned export_support:1;
597
598 /** write-back cache policy (default is write-through) */
599 unsigned writeback_cache:1;
600
601 /** allow parallel lookups and readdir (default is serialized) */
602 unsigned parallel_dirops:1;
603
604 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
605 unsigned handle_killpriv:1;
606
607 /** cache READLINK responses in page cache */
608 unsigned cache_symlinks:1;
609
610 /*
611 * The following bitfields are only for optimization purposes
612 * and hence races in setting them will not cause malfunction
613 */
614
615 /** Is open/release not implemented by fs? */
616 unsigned no_open:1;
617
618 /** Is opendir/releasedir not implemented by fs? */
619 unsigned no_opendir:1;
620
621 /** Is fsync not implemented by fs? */
622 unsigned no_fsync:1;
623
624 /** Is fsyncdir not implemented by fs? */
625 unsigned no_fsyncdir:1;
626
627 /** Is flush not implemented by fs? */
628 unsigned no_flush:1;
629
630 /** Is setxattr not implemented by fs? */
631 unsigned no_setxattr:1;
632
633 /** Is getxattr not implemented by fs? */
634 unsigned no_getxattr:1;
635
636 /** Is listxattr not implemented by fs? */
637 unsigned no_listxattr:1;
638
639 /** Is removexattr not implemented by fs? */
640 unsigned no_removexattr:1;
641
642 /** Are posix file locking primitives not implemented by fs? */
643 unsigned no_lock:1;
644
645 /** Is access not implemented by fs? */
646 unsigned no_access:1;
647
648 /** Is create not implemented by fs? */
649 unsigned no_create:1;
650
651 /** Is interrupt not implemented by fs? */
652 unsigned no_interrupt:1;
653
654 /** Is bmap not implemented by fs? */
655 unsigned no_bmap:1;
656
657 /** Is poll not implemented by fs? */
658 unsigned no_poll:1;
659
660 /** Do multi-page cached writes */
661 unsigned big_writes:1;
662
663 /** Don't apply umask to creation modes */
664 unsigned dont_mask:1;
665
666 /** Are BSD file locking primitives not implemented by fs? */
667 unsigned no_flock:1;
668
669 /** Is fallocate not implemented by fs? */
670 unsigned no_fallocate:1;
671
672 /** Is rename with flags implemented by fs? */
673 unsigned no_rename2:1;
674
675 /** Use enhanced/automatic page cache invalidation. */
676 unsigned auto_inval_data:1;
677
678 /** Filesystem is fully reponsible for page cache invalidation. */
679 unsigned explicit_inval_data:1;
680
681 /** Does the filesystem support readdirplus? */
682 unsigned do_readdirplus:1;
683
684 /** Does the filesystem want adaptive readdirplus? */
685 unsigned readdirplus_auto:1;
686
687 /** Does the filesystem support asynchronous direct-IO submission? */
688 unsigned async_dio:1;
689
690 /** Is lseek not implemented by fs? */
691 unsigned no_lseek:1;
692
693 /** Does the filesystem support posix acls? */
694 unsigned posix_acl:1;
695
696 /** Check permissions based on the file mode or not? */
697 unsigned default_permissions:1;
698
699 /** Allow other than the mounter user to access the filesystem ? */
700 unsigned allow_other:1;
701
702 /** Does the filesystem support copy_file_range? */
703 unsigned no_copy_file_range:1;
704
705 /* Send DESTROY request */
706 unsigned int destroy:1;
707
708 /* Delete dentries that have gone stale */
709 unsigned int delete_stale:1;
710
711 /** Do not create entry in fusectl fs */
712 unsigned int no_control:1;
713
714 /** Do not allow MNT_FORCE umount */
715 unsigned int no_force_umount:1;
716
717 /* Do not show mount options */
718 unsigned int no_mount_options:1;
719
720 /** The number of requests waiting for completion */
721 atomic_t num_waiting;
722
723 /** Negotiated minor version */
724 unsigned minor;
725
726 /** Entry on the fuse_conn_list */
727 struct list_head entry;
728
729 /** Device ID from super block */
730 dev_t dev;
731
732 /** Dentries in the control filesystem */
733 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
734
735 /** number of dentries used in the above array */
736 int ctl_ndents;
737
738 /** Key for lock owner ID scrambling */
739 u32 scramble_key[4];
740
741 /** Version counter for attribute changes */
742 atomic64_t attr_version;
743
744 /** Called on final put */
745 void (*release)(struct fuse_conn *);
746
747 /** Super block for this connection. */
748 struct super_block *sb;
749
750 /** Read/write semaphore to hold when accessing sb. */
751 struct rw_semaphore killsb;
752
753 /** List of device instances belonging to this connection */
754 struct list_head devices;
755 };
756
get_fuse_conn_super(struct super_block * sb)757 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
758 {
759 return sb->s_fs_info;
760 }
761
get_fuse_conn(struct inode * inode)762 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
763 {
764 return get_fuse_conn_super(inode->i_sb);
765 }
766
get_fuse_inode(struct inode * inode)767 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
768 {
769 return container_of(inode, struct fuse_inode, inode);
770 }
771
get_node_id(struct inode * inode)772 static inline u64 get_node_id(struct inode *inode)
773 {
774 return get_fuse_inode(inode)->nodeid;
775 }
776
invalid_nodeid(u64 nodeid)777 static inline int invalid_nodeid(u64 nodeid)
778 {
779 return !nodeid || nodeid == FUSE_ROOT_ID;
780 }
781
fuse_get_attr_version(struct fuse_conn * fc)782 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
783 {
784 return atomic64_read(&fc->attr_version);
785 }
786
787 /** Device operations */
788 extern const struct file_operations fuse_dev_operations;
789
790 extern const struct dentry_operations fuse_dentry_operations;
791 extern const struct dentry_operations fuse_root_dentry_operations;
792
793 /**
794 * Inode to nodeid comparison.
795 */
796 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
797
798 /**
799 * Get a filled in inode
800 */
801 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
802 int generation, struct fuse_attr *attr,
803 u64 attr_valid, u64 attr_version);
804
805 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
806 struct fuse_entry_out *outarg, struct inode **inode);
807
808 /**
809 * Send FORGET command
810 */
811 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
812 u64 nodeid, u64 nlookup);
813
814 struct fuse_forget_link *fuse_alloc_forget(void);
815
816 struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
817 unsigned int max,
818 unsigned int *countp);
819
820 /*
821 * Initialize READ or READDIR request
822 */
823 struct fuse_io_args {
824 union {
825 struct {
826 struct fuse_read_in in;
827 u64 attr_ver;
828 } read;
829 struct {
830 struct fuse_write_in in;
831 struct fuse_write_out out;
832 } write;
833 };
834 struct fuse_args_pages ap;
835 struct fuse_io_priv *io;
836 struct fuse_file *ff;
837 };
838
839 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
840 size_t count, int opcode);
841
842
843 /**
844 * Send OPEN or OPENDIR request
845 */
846 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
847
848 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
849 void fuse_file_free(struct fuse_file *ff);
850 void fuse_finish_open(struct inode *inode, struct file *file);
851
852 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags);
853
854 /**
855 * Send RELEASE or RELEASEDIR request
856 */
857 void fuse_release_common(struct file *file, bool isdir);
858
859 /**
860 * Send FSYNC or FSYNCDIR request
861 */
862 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
863 int datasync, int opcode);
864
865 /**
866 * Notify poll wakeup
867 */
868 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
869 struct fuse_notify_poll_wakeup_out *outarg);
870
871 /**
872 * Initialize file operations on a regular file
873 */
874 void fuse_init_file_inode(struct inode *inode);
875
876 /**
877 * Initialize inode operations on regular files and special files
878 */
879 void fuse_init_common(struct inode *inode);
880
881 /**
882 * Initialize inode and file operations on a directory
883 */
884 void fuse_init_dir(struct inode *inode);
885
886 /**
887 * Initialize inode operations on a symlink
888 */
889 void fuse_init_symlink(struct inode *inode);
890
891 /**
892 * Change attributes of an inode
893 */
894 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
895 u64 attr_valid, u64 attr_version);
896
897 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
898 u64 attr_valid);
899
900 /**
901 * Initialize the client device
902 */
903 int fuse_dev_init(void);
904
905 /**
906 * Cleanup the client device
907 */
908 void fuse_dev_cleanup(void);
909
910 int fuse_ctl_init(void);
911 void __exit fuse_ctl_cleanup(void);
912
913 /**
914 * Simple request sending that does request allocation and freeing
915 */
916 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
917 int fuse_simple_background(struct fuse_conn *fc, struct fuse_args *args,
918 gfp_t gfp_flags);
919
920 /**
921 * End a finished request
922 */
923 void fuse_request_end(struct fuse_conn *fc, struct fuse_req *req);
924
925 /* Abort all requests */
926 void fuse_abort_conn(struct fuse_conn *fc);
927 void fuse_wait_aborted(struct fuse_conn *fc);
928
929 /**
930 * Invalidate inode attributes
931 */
932 void fuse_invalidate_attr(struct inode *inode);
933
934 void fuse_invalidate_entry_cache(struct dentry *entry);
935
936 void fuse_invalidate_atime(struct inode *inode);
937
938 u64 entry_attr_timeout(struct fuse_entry_out *o);
939 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
940
941 /**
942 * Acquire reference to fuse_conn
943 */
944 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
945
946 /**
947 * Initialize fuse_conn
948 */
949 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns,
950 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
951
952 /**
953 * Release reference to fuse_conn
954 */
955 void fuse_conn_put(struct fuse_conn *fc);
956
957 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
958 struct fuse_dev *fuse_dev_alloc(void);
959 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
960 void fuse_dev_free(struct fuse_dev *fud);
961 void fuse_send_init(struct fuse_conn *fc);
962
963 /**
964 * Fill in superblock and initialize fuse connection
965 * @sb: partially-initialized superblock to fill in
966 * @ctx: mount context
967 */
968 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
969
970 /**
971 * Disassociate fuse connection from superblock and kill the superblock
972 *
973 * Calls kill_anon_super(), do not use with bdev mounts.
974 */
975 void fuse_kill_sb_anon(struct super_block *sb);
976
977 /**
978 * Add connection to control filesystem
979 */
980 int fuse_ctl_add_conn(struct fuse_conn *fc);
981
982 /**
983 * Remove connection from control filesystem
984 */
985 void fuse_ctl_remove_conn(struct fuse_conn *fc);
986
987 /**
988 * Is file type valid?
989 */
990 int fuse_valid_type(int m);
991
992 /**
993 * Is current process allowed to perform filesystem operation?
994 */
995 int fuse_allow_current_process(struct fuse_conn *fc);
996
997 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
998
999 void fuse_update_ctime(struct inode *inode);
1000
1001 int fuse_update_attributes(struct inode *inode, struct file *file);
1002
1003 void fuse_flush_writepages(struct inode *inode);
1004
1005 void fuse_set_nowrite(struct inode *inode);
1006 void fuse_release_nowrite(struct inode *inode);
1007
1008 /**
1009 * File-system tells the kernel to invalidate cache for the given node id.
1010 */
1011 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
1012 loff_t offset, loff_t len);
1013
1014 /**
1015 * File-system tells the kernel to invalidate parent attributes and
1016 * the dentry matching parent/name.
1017 *
1018 * If the child_nodeid is non-zero and:
1019 * - matches the inode number for the dentry matching parent/name,
1020 * - is not a mount point
1021 * - is a file or oan empty directory
1022 * then the dentry is unhashed (d_delete()).
1023 */
1024 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
1025 u64 child_nodeid, struct qstr *name);
1026
1027 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
1028 bool isdir);
1029
1030 /**
1031 * fuse_direct_io() flags
1032 */
1033
1034 /** If set, it is WRITE; otherwise - READ */
1035 #define FUSE_DIO_WRITE (1 << 0)
1036
1037 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1038 #define FUSE_DIO_CUSE (1 << 1)
1039
1040 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1041 loff_t *ppos, int flags);
1042 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1043 unsigned int flags);
1044 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1045 unsigned long arg, unsigned int flags);
1046 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1047 int fuse_dev_release(struct inode *inode, struct file *file);
1048
1049 bool fuse_write_update_size(struct inode *inode, loff_t pos);
1050
1051 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1052 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1053
1054 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1055 struct file *file);
1056
1057 void fuse_set_initialized(struct fuse_conn *fc);
1058
1059 void fuse_unlock_inode(struct inode *inode, bool locked);
1060 bool fuse_lock_inode(struct inode *inode);
1061
1062 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1063 size_t size, int flags);
1064 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1065 size_t size);
1066 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1067 int fuse_removexattr(struct inode *inode, const char *name);
1068 extern const struct xattr_handler *fuse_xattr_handlers[];
1069 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1070 extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1071
1072 struct posix_acl;
1073 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
1074 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
1075
1076
1077 /* readdir.c */
1078 int fuse_readdir(struct file *file, struct dir_context *ctx);
1079
1080 /**
1081 * Return the number of bytes in an arguments list
1082 */
1083 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1084
1085 /**
1086 * Get the next unique ID for a request
1087 */
1088 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1089 void fuse_free_conn(struct fuse_conn *fc);
1090
1091 #endif /* _FS_FUSE_I_H */
1092
