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 /* Bad inode */
162 FUSE_I_BAD,
163 };
164
165 struct fuse_conn;
166 struct fuse_release_args;
167
168 /** FUSE specific file data */
169 struct fuse_file {
170 /** Fuse connection for this file */
171 struct fuse_conn *fc;
172
173 /* Argument space reserved for release */
174 struct fuse_release_args *release_args;
175
176 /** Kernel file handle guaranteed to be unique */
177 u64 kh;
178
179 /** File handle used by userspace */
180 u64 fh;
181
182 /** Node id of this file */
183 u64 nodeid;
184
185 /** Refcount */
186 refcount_t count;
187
188 /** FOPEN_* flags returned by open */
189 u32 open_flags;
190
191 /** Entry on inode's write_files list */
192 struct list_head write_entry;
193
194 /* Readdir related */
195 struct {
196 /*
197 * Protects below fields against (crazy) parallel readdir on
198 * same open file. Uncontended in the normal case.
199 */
200 struct mutex lock;
201
202 /* Dir stream position */
203 loff_t pos;
204
205 /* Offset in cache */
206 loff_t cache_off;
207
208 /* Version of cache we are reading */
209 u64 version;
210
211 } readdir;
212
213 /** RB node to be linked on fuse_conn->polled_files */
214 struct rb_node polled_node;
215
216 /** Wait queue head for poll */
217 wait_queue_head_t poll_wait;
218
219 /** Has flock been performed on this file? */
220 bool flock:1;
221 };
222
223 /** One input argument of a request */
224 struct fuse_in_arg {
225 unsigned size;
226 const void *value;
227 };
228
229 /** One output argument of a request */
230 struct fuse_arg {
231 unsigned size;
232 void *value;
233 };
234
235 /** FUSE page descriptor */
236 struct fuse_page_desc {
237 unsigned int length;
238 unsigned int offset;
239 };
240
241 struct fuse_args {
242 uint64_t nodeid;
243 uint32_t opcode;
244 unsigned short in_numargs;
245 unsigned short out_numargs;
246 bool force:1;
247 bool noreply:1;
248 bool nocreds:1;
249 bool in_pages:1;
250 bool out_pages:1;
251 bool user_pages:1;
252 bool out_argvar:1;
253 bool page_zeroing:1;
254 bool page_replace:1;
255 bool may_block:1;
256 struct fuse_in_arg in_args[3];
257 struct fuse_arg out_args[2];
258 void (*end)(struct fuse_conn *fc, struct fuse_args *args, int error);
259
260 /* Path used for completing d_canonical_path */
261 struct path *canonical_path;
262 };
263
264 struct fuse_args_pages {
265 struct fuse_args args;
266 struct page **pages;
267 struct fuse_page_desc *descs;
268 unsigned int num_pages;
269 };
270
271 #define FUSE_ARGS(args) struct fuse_args args = {}
272
273 /** The request IO state (for asynchronous processing) */
274 struct fuse_io_priv {
275 struct kref refcnt;
276 int async;
277 spinlock_t lock;
278 unsigned reqs;
279 ssize_t bytes;
280 size_t size;
281 __u64 offset;
282 bool write;
283 bool should_dirty;
284 int err;
285 struct kiocb *iocb;
286 struct completion *done;
287 bool blocking;
288 };
289
290 #define FUSE_IO_PRIV_SYNC(i) \
291 { \
292 .refcnt = KREF_INIT(1), \
293 .async = 0, \
294 .iocb = i, \
295 }
296
297 /**
298 * Request flags
299 *
300 * FR_ISREPLY: set if the request has reply
301 * FR_FORCE: force sending of the request even if interrupted
302 * FR_BACKGROUND: request is sent in the background
303 * FR_WAITING: request is counted as "waiting"
304 * FR_ABORTED: the request was aborted
305 * FR_INTERRUPTED: the request has been interrupted
306 * FR_LOCKED: data is being copied to/from the request
307 * FR_PENDING: request is not yet in userspace
308 * FR_SENT: request is in userspace, waiting for an answer
309 * FR_FINISHED: request is finished
310 * FR_PRIVATE: request is on private list
311 * FR_ASYNC: request is asynchronous
312 */
313 enum fuse_req_flag {
314 FR_ISREPLY,
315 FR_FORCE,
316 FR_BACKGROUND,
317 FR_WAITING,
318 FR_ABORTED,
319 FR_INTERRUPTED,
320 FR_LOCKED,
321 FR_PENDING,
322 FR_SENT,
323 FR_FINISHED,
324 FR_PRIVATE,
325 FR_ASYNC,
326 };
327
328 /**
329 * A request to the client
330 *
331 * .waitq.lock protects the following fields:
332 * - FR_ABORTED
333 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
334 */
335 struct fuse_req {
336 /** This can be on either pending processing or io lists in
337 fuse_conn */
338 struct list_head list;
339
340 /** Entry on the interrupts list */
341 struct list_head intr_entry;
342
343 /* Input/output arguments */
344 struct fuse_args *args;
345
346 /** refcount */
347 refcount_t count;
348
349 /* Request flags, updated with test/set/clear_bit() */
350 unsigned long flags;
351
352 /* The request input header */
353 struct {
354 struct fuse_in_header h;
355 } in;
356
357 /* The request output header */
358 struct {
359 struct fuse_out_header h;
360 } out;
361
362 /** Used to wake up the task waiting for completion of request*/
363 wait_queue_head_t waitq;
364
365 #if IS_ENABLED(CONFIG_VIRTIO_FS)
366 /** virtio-fs's physically contiguous buffer for in and out args */
367 void *argbuf;
368 #endif
369 };
370
371 struct fuse_iqueue;
372
373 /**
374 * Input queue callbacks
375 *
376 * Input queue signalling is device-specific. For example, the /dev/fuse file
377 * uses fiq->waitq and fasync to wake processes that are waiting on queue
378 * readiness. These callbacks allow other device types to respond to input
379 * queue activity.
380 */
381 struct fuse_iqueue_ops {
382 /**
383 * Signal that a forget has been queued
384 */
385 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
386 __releases(fiq->lock);
387
388 /**
389 * Signal that an INTERRUPT request has been queued
390 */
391 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
392 __releases(fiq->lock);
393
394 /**
395 * Signal that a request has been queued
396 */
397 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
398 __releases(fiq->lock);
399
400 /**
401 * Clean up when fuse_iqueue is destroyed
402 */
403 void (*release)(struct fuse_iqueue *fiq);
404 };
405
406 /** /dev/fuse input queue operations */
407 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
408
409 struct fuse_iqueue {
410 /** Connection established */
411 unsigned connected;
412
413 /** Lock protecting accesses to members of this structure */
414 spinlock_t lock;
415
416 /** Readers of the connection are waiting on this */
417 wait_queue_head_t waitq;
418
419 /** The next unique request id */
420 u64 reqctr;
421
422 /** The list of pending requests */
423 struct list_head pending;
424
425 /** Pending interrupts */
426 struct list_head interrupts;
427
428 /** Queue of pending forgets */
429 struct fuse_forget_link forget_list_head;
430 struct fuse_forget_link *forget_list_tail;
431
432 /** Batching of FORGET requests (positive indicates FORGET batch) */
433 int forget_batch;
434
435 /** O_ASYNC requests */
436 struct fasync_struct *fasync;
437
438 /** Device-specific callbacks */
439 const struct fuse_iqueue_ops *ops;
440
441 /** Device-specific state */
442 void *priv;
443 };
444
445 #define FUSE_PQ_HASH_BITS 8
446 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
447
448 struct fuse_pqueue {
449 /** Connection established */
450 unsigned connected;
451
452 /** Lock protecting accessess to members of this structure */
453 spinlock_t lock;
454
455 /** Hash table of requests being processed */
456 struct list_head *processing;
457
458 /** The list of requests under I/O */
459 struct list_head io;
460 };
461
462 /**
463 * Fuse device instance
464 */
465 struct fuse_dev {
466 /** Fuse connection for this device */
467 struct fuse_conn *fc;
468
469 /** Processing queue */
470 struct fuse_pqueue pq;
471
472 /** list entry on fc->devices */
473 struct list_head entry;
474 };
475
476 struct fuse_fs_context {
477 int fd;
478 unsigned int rootmode;
479 kuid_t user_id;
480 kgid_t group_id;
481 bool is_bdev:1;
482 bool fd_present:1;
483 bool rootmode_present:1;
484 bool user_id_present:1;
485 bool group_id_present:1;
486 bool default_permissions:1;
487 bool allow_other:1;
488 bool destroy:1;
489 bool no_control:1;
490 bool no_force_umount:1;
491 bool no_mount_options:1;
492 unsigned int max_read;
493 unsigned int blksize;
494 const char *subtype;
495
496 /* fuse_dev pointer to fill in, should contain NULL on entry */
497 void **fudptr;
498 };
499
500 /**
501 * A Fuse connection.
502 *
503 * This structure is created, when the filesystem is mounted, and is
504 * destroyed, when the client device is closed and the filesystem is
505 * unmounted.
506 */
507 struct fuse_conn {
508 /** Lock protecting accessess to members of this structure */
509 spinlock_t lock;
510
511 /** Refcount */
512 refcount_t count;
513
514 /** Number of fuse_dev's */
515 atomic_t dev_count;
516
517 struct rcu_head rcu;
518
519 /** The user id for this mount */
520 kuid_t user_id;
521
522 /** The group id for this mount */
523 kgid_t group_id;
524
525 /** The pid namespace for this mount */
526 struct pid_namespace *pid_ns;
527
528 /** The user namespace for this mount */
529 struct user_namespace *user_ns;
530
531 /** Maximum read size */
532 unsigned max_read;
533
534 /** Maximum write size */
535 unsigned max_write;
536
537 /** Maxmum number of pages that can be used in a single request */
538 unsigned int max_pages;
539
540 /** Input queue */
541 struct fuse_iqueue iq;
542
543 /** The next unique kernel file handle */
544 atomic64_t khctr;
545
546 /** rbtree of fuse_files waiting for poll events indexed by ph */
547 struct rb_root polled_files;
548
549 /** Maximum number of outstanding background requests */
550 unsigned max_background;
551
552 /** Number of background requests at which congestion starts */
553 unsigned congestion_threshold;
554
555 /** Number of requests currently in the background */
556 unsigned num_background;
557
558 /** Number of background requests currently queued for userspace */
559 unsigned active_background;
560
561 /** The list of background requests set aside for later queuing */
562 struct list_head bg_queue;
563
564 /** Protects: max_background, congestion_threshold, num_background,
565 * active_background, bg_queue, blocked */
566 spinlock_t bg_lock;
567
568 /** Flag indicating that INIT reply has been received. Allocating
569 * any fuse request will be suspended until the flag is set */
570 int initialized;
571
572 /** Flag indicating if connection is blocked. This will be
573 the case before the INIT reply is received, and if there
574 are too many outstading backgrounds requests */
575 int blocked;
576
577 /** waitq for blocked connection */
578 wait_queue_head_t blocked_waitq;
579
580 /** Connection established, cleared on umount, connection
581 abort and device release */
582 unsigned connected;
583
584 /** Connection aborted via sysfs */
585 bool aborted;
586
587 /** Connection failed (version mismatch). Cannot race with
588 setting other bitfields since it is only set once in INIT
589 reply, before any other request, and never cleared */
590 unsigned conn_error:1;
591
592 /** Connection successful. Only set in INIT */
593 unsigned conn_init:1;
594
595 /** Do readpages asynchronously? Only set in INIT */
596 unsigned async_read:1;
597
598 /** Return an unique read error after abort. Only set in INIT */
599 unsigned abort_err:1;
600
601 /** Do not send separate SETATTR request before open(O_TRUNC) */
602 unsigned atomic_o_trunc:1;
603
604 /** Filesystem supports NFS exporting. Only set in INIT */
605 unsigned export_support:1;
606
607 /** write-back cache policy (default is write-through) */
608 unsigned writeback_cache:1;
609
610 /** allow parallel lookups and readdir (default is serialized) */
611 unsigned parallel_dirops:1;
612
613 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
614 unsigned handle_killpriv:1;
615
616 /** cache READLINK responses in page cache */
617 unsigned cache_symlinks:1;
618
619 /*
620 * The following bitfields are only for optimization purposes
621 * and hence races in setting them will not cause malfunction
622 */
623
624 /** Is open/release not implemented by fs? */
625 unsigned no_open:1;
626
627 /** Is opendir/releasedir not implemented by fs? */
628 unsigned no_opendir:1;
629
630 /** Is fsync not implemented by fs? */
631 unsigned no_fsync:1;
632
633 /** Is fsyncdir not implemented by fs? */
634 unsigned no_fsyncdir:1;
635
636 /** Is flush not implemented by fs? */
637 unsigned no_flush:1;
638
639 /** Is setxattr not implemented by fs? */
640 unsigned no_setxattr:1;
641
642 /** Is getxattr not implemented by fs? */
643 unsigned no_getxattr:1;
644
645 /** Is listxattr not implemented by fs? */
646 unsigned no_listxattr:1;
647
648 /** Is removexattr not implemented by fs? */
649 unsigned no_removexattr:1;
650
651 /** Are posix file locking primitives not implemented by fs? */
652 unsigned no_lock:1;
653
654 /** Is access not implemented by fs? */
655 unsigned no_access:1;
656
657 /** Is create not implemented by fs? */
658 unsigned no_create:1;
659
660 /** Is interrupt not implemented by fs? */
661 unsigned no_interrupt:1;
662
663 /** Is bmap not implemented by fs? */
664 unsigned no_bmap:1;
665
666 /** Is poll not implemented by fs? */
667 unsigned no_poll:1;
668
669 /** Do multi-page cached writes */
670 unsigned big_writes:1;
671
672 /** Don't apply umask to creation modes */
673 unsigned dont_mask:1;
674
675 /** Are BSD file locking primitives not implemented by fs? */
676 unsigned no_flock:1;
677
678 /** Is fallocate not implemented by fs? */
679 unsigned no_fallocate:1;
680
681 /** Is rename with flags implemented by fs? */
682 unsigned no_rename2:1;
683
684 /** Use enhanced/automatic page cache invalidation. */
685 unsigned auto_inval_data:1;
686
687 /** Filesystem is fully reponsible for page cache invalidation. */
688 unsigned explicit_inval_data:1;
689
690 /** Does the filesystem support readdirplus? */
691 unsigned do_readdirplus:1;
692
693 /** Does the filesystem want adaptive readdirplus? */
694 unsigned readdirplus_auto:1;
695
696 /** Does the filesystem support asynchronous direct-IO submission? */
697 unsigned async_dio:1;
698
699 /** Is lseek not implemented by fs? */
700 unsigned no_lseek:1;
701
702 /** Does the filesystem support posix acls? */
703 unsigned posix_acl:1;
704
705 /** Check permissions based on the file mode or not? */
706 unsigned default_permissions:1;
707
708 /** Allow other than the mounter user to access the filesystem ? */
709 unsigned allow_other:1;
710
711 /** Does the filesystem support copy_file_range? */
712 unsigned no_copy_file_range:1;
713
714 /* Send DESTROY request */
715 unsigned int destroy:1;
716
717 /* Delete dentries that have gone stale */
718 unsigned int delete_stale:1;
719
720 /** Do not create entry in fusectl fs */
721 unsigned int no_control:1;
722
723 /** Do not allow MNT_FORCE umount */
724 unsigned int no_force_umount:1;
725
726 /* Do not show mount options */
727 unsigned int no_mount_options:1;
728
729 /** The number of requests waiting for completion */
730 atomic_t num_waiting;
731
732 /** Negotiated minor version */
733 unsigned minor;
734
735 /** Entry on the fuse_conn_list */
736 struct list_head entry;
737
738 /** Device ID from super block */
739 dev_t dev;
740
741 /** Dentries in the control filesystem */
742 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
743
744 /** number of dentries used in the above array */
745 int ctl_ndents;
746
747 /** Key for lock owner ID scrambling */
748 u32 scramble_key[4];
749
750 /** Version counter for attribute changes */
751 atomic64_t attr_version;
752
753 /** Called on final put */
754 void (*release)(struct fuse_conn *);
755
756 /** Super block for this connection. */
757 struct super_block *sb;
758
759 /** Read/write semaphore to hold when accessing sb. */
760 struct rw_semaphore killsb;
761
762 /** List of device instances belonging to this connection */
763 struct list_head devices;
764 };
765
get_fuse_conn_super(struct super_block * sb)766 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
767 {
768 return sb->s_fs_info;
769 }
770
get_fuse_conn(struct inode * inode)771 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
772 {
773 return get_fuse_conn_super(inode->i_sb);
774 }
775
get_fuse_inode(struct inode * inode)776 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
777 {
778 return container_of(inode, struct fuse_inode, inode);
779 }
780
get_node_id(struct inode * inode)781 static inline u64 get_node_id(struct inode *inode)
782 {
783 return get_fuse_inode(inode)->nodeid;
784 }
785
invalid_nodeid(u64 nodeid)786 static inline int invalid_nodeid(u64 nodeid)
787 {
788 return !nodeid || nodeid == FUSE_ROOT_ID;
789 }
790
fuse_get_attr_version(struct fuse_conn * fc)791 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
792 {
793 return atomic64_read(&fc->attr_version);
794 }
795
fuse_make_bad(struct inode * inode)796 static inline void fuse_make_bad(struct inode *inode)
797 {
798 set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
799 }
800
fuse_is_bad(struct inode * inode)801 static inline bool fuse_is_bad(struct inode *inode)
802 {
803 return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
804 }
805
806 /** Device operations */
807 extern const struct file_operations fuse_dev_operations;
808
809 extern const struct dentry_operations fuse_dentry_operations;
810 extern const struct dentry_operations fuse_root_dentry_operations;
811
812 /**
813 * Inode to nodeid comparison.
814 */
815 int fuse_inode_eq(struct inode *inode, void *_nodeidp);
816
817 /**
818 * Get a filled in inode
819 */
820 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
821 int generation, struct fuse_attr *attr,
822 u64 attr_valid, u64 attr_version);
823
824 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
825 struct fuse_entry_out *outarg, struct inode **inode);
826
827 /**
828 * Send FORGET command
829 */
830 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
831 u64 nodeid, u64 nlookup);
832
833 struct fuse_forget_link *fuse_alloc_forget(void);
834
835 struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
836 unsigned int max,
837 unsigned int *countp);
838
839 /*
840 * Initialize READ or READDIR request
841 */
842 struct fuse_io_args {
843 union {
844 struct {
845 struct fuse_read_in in;
846 u64 attr_ver;
847 } read;
848 struct {
849 struct fuse_write_in in;
850 struct fuse_write_out out;
851 bool page_locked;
852 } write;
853 };
854 struct fuse_args_pages ap;
855 struct fuse_io_priv *io;
856 struct fuse_file *ff;
857 };
858
859 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
860 size_t count, int opcode);
861
862
863 /**
864 * Send OPEN or OPENDIR request
865 */
866 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
867
868 struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
869 void fuse_file_free(struct fuse_file *ff);
870 void fuse_finish_open(struct inode *inode, struct file *file);
871
872 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags);
873
874 /**
875 * Send RELEASE or RELEASEDIR request
876 */
877 void fuse_release_common(struct file *file, bool isdir);
878
879 /**
880 * Send FSYNC or FSYNCDIR request
881 */
882 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
883 int datasync, int opcode);
884
885 /**
886 * Notify poll wakeup
887 */
888 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
889 struct fuse_notify_poll_wakeup_out *outarg);
890
891 /**
892 * Initialize file operations on a regular file
893 */
894 void fuse_init_file_inode(struct inode *inode);
895
896 /**
897 * Initialize inode operations on regular files and special files
898 */
899 void fuse_init_common(struct inode *inode);
900
901 /**
902 * Initialize inode and file operations on a directory
903 */
904 void fuse_init_dir(struct inode *inode);
905
906 /**
907 * Initialize inode operations on a symlink
908 */
909 void fuse_init_symlink(struct inode *inode);
910
911 /**
912 * Change attributes of an inode
913 */
914 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
915 u64 attr_valid, u64 attr_version);
916
917 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
918 u64 attr_valid);
919
920 /**
921 * Initialize the client device
922 */
923 int fuse_dev_init(void);
924
925 /**
926 * Cleanup the client device
927 */
928 void fuse_dev_cleanup(void);
929
930 int fuse_ctl_init(void);
931 void __exit fuse_ctl_cleanup(void);
932
933 /**
934 * Simple request sending that does request allocation and freeing
935 */
936 ssize_t fuse_simple_request(struct fuse_conn *fc, struct fuse_args *args);
937 int fuse_simple_background(struct fuse_conn *fc, struct fuse_args *args,
938 gfp_t gfp_flags);
939
940 /**
941 * End a finished request
942 */
943 void fuse_request_end(struct fuse_conn *fc, struct fuse_req *req);
944
945 /* Abort all requests */
946 void fuse_abort_conn(struct fuse_conn *fc);
947 void fuse_wait_aborted(struct fuse_conn *fc);
948
949 /**
950 * Invalidate inode attributes
951 */
952 void fuse_invalidate_attr(struct inode *inode);
953
954 void fuse_invalidate_entry_cache(struct dentry *entry);
955
956 void fuse_invalidate_atime(struct inode *inode);
957
958 u64 entry_attr_timeout(struct fuse_entry_out *o);
959 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
960
961 /**
962 * Acquire reference to fuse_conn
963 */
964 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
965
966 /**
967 * Initialize fuse_conn
968 */
969 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns,
970 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
971
972 /**
973 * Release reference to fuse_conn
974 */
975 void fuse_conn_put(struct fuse_conn *fc);
976
977 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
978 struct fuse_dev *fuse_dev_alloc(void);
979 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
980 void fuse_dev_free(struct fuse_dev *fud);
981 void fuse_send_init(struct fuse_conn *fc);
982
983 /**
984 * Fill in superblock and initialize fuse connection
985 * @sb: partially-initialized superblock to fill in
986 * @ctx: mount context
987 */
988 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
989
990 /**
991 * Disassociate fuse connection from superblock and kill the superblock
992 *
993 * Calls kill_anon_super(), do not use with bdev mounts.
994 */
995 void fuse_kill_sb_anon(struct super_block *sb);
996
997 /**
998 * Add connection to control filesystem
999 */
1000 int fuse_ctl_add_conn(struct fuse_conn *fc);
1001
1002 /**
1003 * Remove connection from control filesystem
1004 */
1005 void fuse_ctl_remove_conn(struct fuse_conn *fc);
1006
1007 /**
1008 * Is file type valid?
1009 */
1010 int fuse_valid_type(int m);
1011
1012 bool fuse_invalid_attr(struct fuse_attr *attr);
1013
1014 /**
1015 * Is current process allowed to perform filesystem operation?
1016 */
1017 int fuse_allow_current_process(struct fuse_conn *fc);
1018
1019 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1020
1021 void fuse_update_ctime(struct inode *inode);
1022
1023 int fuse_update_attributes(struct inode *inode, struct file *file);
1024
1025 void fuse_flush_writepages(struct inode *inode);
1026
1027 void fuse_set_nowrite(struct inode *inode);
1028 void fuse_release_nowrite(struct inode *inode);
1029
1030 /**
1031 * File-system tells the kernel to invalidate cache for the given node id.
1032 */
1033 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
1034 loff_t offset, loff_t len);
1035
1036 /**
1037 * File-system tells the kernel to invalidate parent attributes and
1038 * the dentry matching parent/name.
1039 *
1040 * If the child_nodeid is non-zero and:
1041 * - matches the inode number for the dentry matching parent/name,
1042 * - is not a mount point
1043 * - is a file or oan empty directory
1044 * then the dentry is unhashed (d_delete()).
1045 */
1046 int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
1047 u64 child_nodeid, struct qstr *name);
1048
1049 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
1050 bool isdir);
1051
1052 /**
1053 * fuse_direct_io() flags
1054 */
1055
1056 /** If set, it is WRITE; otherwise - READ */
1057 #define FUSE_DIO_WRITE (1 << 0)
1058
1059 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1060 #define FUSE_DIO_CUSE (1 << 1)
1061
1062 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1063 loff_t *ppos, int flags);
1064 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1065 unsigned int flags);
1066 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1067 unsigned long arg, unsigned int flags);
1068 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1069 int fuse_dev_release(struct inode *inode, struct file *file);
1070
1071 bool fuse_write_update_size(struct inode *inode, loff_t pos);
1072
1073 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1074 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1075
1076 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1077 struct file *file);
1078
1079 void fuse_set_initialized(struct fuse_conn *fc);
1080
1081 void fuse_unlock_inode(struct inode *inode, bool locked);
1082 bool fuse_lock_inode(struct inode *inode);
1083
1084 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1085 size_t size, int flags);
1086 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1087 size_t size);
1088 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1089 int fuse_removexattr(struct inode *inode, const char *name);
1090 extern const struct xattr_handler *fuse_xattr_handlers[];
1091 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1092 extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1093
1094 struct posix_acl;
1095 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
1096 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
1097
1098
1099 /* readdir.c */
1100 int fuse_readdir(struct file *file, struct dir_context *ctx);
1101
1102 /**
1103 * Return the number of bytes in an arguments list
1104 */
1105 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1106
1107 /**
1108 * Get the next unique ID for a request
1109 */
1110 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1111 void fuse_free_conn(struct fuse_conn *fc);
1112
1113 #endif /* _FS_FUSE_I_H */
1114