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 rb_root 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 * Can't take inode lock in fault path (leads to circular dependency).
154 * Introduce another semaphore which can be taken in fault path and
155 * then other filesystem paths can take this to block faults.
156 */
157 struct rw_semaphore i_mmap_sem;
158
159 #ifdef CONFIG_FUSE_DAX
160 /*
161 * Dax specific inode data
162 */
163 struct fuse_inode_dax *dax;
164 #endif
165 };
166
167 /** FUSE inode state bits */
168 enum {
169 /** Advise readdirplus */
170 FUSE_I_ADVISE_RDPLUS,
171 /** Initialized with readdirplus */
172 FUSE_I_INIT_RDPLUS,
173 /** An operation changing file size is in progress */
174 FUSE_I_SIZE_UNSTABLE,
175 };
176
177 struct fuse_conn;
178 struct fuse_mount;
179 struct fuse_release_args;
180
181 /** FUSE specific file data */
182 struct fuse_file {
183 /** Fuse connection for this file */
184 struct fuse_mount *fm;
185
186 /* Argument space reserved for release */
187 struct fuse_release_args *release_args;
188
189 /** Kernel file handle guaranteed to be unique */
190 u64 kh;
191
192 /** File handle used by userspace */
193 u64 fh;
194
195 /** Node id of this file */
196 u64 nodeid;
197
198 /** Refcount */
199 refcount_t count;
200
201 /** FOPEN_* flags returned by open */
202 u32 open_flags;
203
204 /** Entry on inode's write_files list */
205 struct list_head write_entry;
206
207 /* Readdir related */
208 struct {
209 /*
210 * Protects below fields against (crazy) parallel readdir on
211 * same open file. Uncontended in the normal case.
212 */
213 struct mutex lock;
214
215 /* Dir stream position */
216 loff_t pos;
217
218 /* Offset in cache */
219 loff_t cache_off;
220
221 /* Version of cache we are reading */
222 u64 version;
223
224 } readdir;
225
226 /** RB node to be linked on fuse_conn->polled_files */
227 struct rb_node polled_node;
228
229 /** Wait queue head for poll */
230 wait_queue_head_t poll_wait;
231
232 /** Has flock been performed on this file? */
233 bool flock:1;
234 };
235
236 /** One input argument of a request */
237 struct fuse_in_arg {
238 unsigned size;
239 const void *value;
240 };
241
242 /** One output argument of a request */
243 struct fuse_arg {
244 unsigned size;
245 void *value;
246 };
247
248 /** FUSE page descriptor */
249 struct fuse_page_desc {
250 unsigned int length;
251 unsigned int offset;
252 };
253
254 struct fuse_args {
255 uint64_t nodeid;
256 uint32_t opcode;
257 unsigned short in_numargs;
258 unsigned short out_numargs;
259 bool force:1;
260 bool noreply:1;
261 bool nocreds:1;
262 bool in_pages:1;
263 bool out_pages:1;
264 bool out_argvar:1;
265 bool page_zeroing:1;
266 bool page_replace:1;
267 bool may_block:1;
268 struct fuse_in_arg in_args[3];
269 struct fuse_arg out_args[2];
270 void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
271 };
272
273 struct fuse_args_pages {
274 struct fuse_args args;
275 struct page **pages;
276 struct fuse_page_desc *descs;
277 unsigned int num_pages;
278 };
279
280 #define FUSE_ARGS(args) struct fuse_args args = {}
281
282 /** The request IO state (for asynchronous processing) */
283 struct fuse_io_priv {
284 struct kref refcnt;
285 int async;
286 spinlock_t lock;
287 unsigned reqs;
288 ssize_t bytes;
289 size_t size;
290 __u64 offset;
291 bool write;
292 bool should_dirty;
293 int err;
294 struct kiocb *iocb;
295 struct completion *done;
296 bool blocking;
297 };
298
299 #define FUSE_IO_PRIV_SYNC(i) \
300 { \
301 .refcnt = KREF_INIT(1), \
302 .async = 0, \
303 .iocb = i, \
304 }
305
306 /**
307 * Request flags
308 *
309 * FR_ISREPLY: set if the request has reply
310 * FR_FORCE: force sending of the request even if interrupted
311 * FR_BACKGROUND: request is sent in the background
312 * FR_WAITING: request is counted as "waiting"
313 * FR_ABORTED: the request was aborted
314 * FR_INTERRUPTED: the request has been interrupted
315 * FR_LOCKED: data is being copied to/from the request
316 * FR_PENDING: request is not yet in userspace
317 * FR_SENT: request is in userspace, waiting for an answer
318 * FR_FINISHED: request is finished
319 * FR_PRIVATE: request is on private list
320 * FR_ASYNC: request is asynchronous
321 */
322 enum fuse_req_flag {
323 FR_ISREPLY,
324 FR_FORCE,
325 FR_BACKGROUND,
326 FR_WAITING,
327 FR_ABORTED,
328 FR_INTERRUPTED,
329 FR_LOCKED,
330 FR_PENDING,
331 FR_SENT,
332 FR_FINISHED,
333 FR_PRIVATE,
334 FR_ASYNC,
335 };
336
337 /**
338 * A request to the client
339 *
340 * .waitq.lock protects the following fields:
341 * - FR_ABORTED
342 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
343 */
344 struct fuse_req {
345 /** This can be on either pending processing or io lists in
346 fuse_conn */
347 struct list_head list;
348
349 /** Entry on the interrupts list */
350 struct list_head intr_entry;
351
352 /* Input/output arguments */
353 struct fuse_args *args;
354
355 /** refcount */
356 refcount_t count;
357
358 /* Request flags, updated with test/set/clear_bit() */
359 unsigned long flags;
360
361 /* The request input header */
362 struct {
363 struct fuse_in_header h;
364 } in;
365
366 /* The request output header */
367 struct {
368 struct fuse_out_header h;
369 } out;
370
371 /** Used to wake up the task waiting for completion of request*/
372 wait_queue_head_t waitq;
373
374 #if IS_ENABLED(CONFIG_VIRTIO_FS)
375 /** virtio-fs's physically contiguous buffer for in and out args */
376 void *argbuf;
377 #endif
378
379 /** fuse_mount this request belongs to */
380 struct fuse_mount *fm;
381 };
382
383 struct fuse_iqueue;
384
385 /**
386 * Input queue callbacks
387 *
388 * Input queue signalling is device-specific. For example, the /dev/fuse file
389 * uses fiq->waitq and fasync to wake processes that are waiting on queue
390 * readiness. These callbacks allow other device types to respond to input
391 * queue activity.
392 */
393 struct fuse_iqueue_ops {
394 /**
395 * Signal that a forget has been queued
396 */
397 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
398 __releases(fiq->lock);
399
400 /**
401 * Signal that an INTERRUPT request has been queued
402 */
403 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
404 __releases(fiq->lock);
405
406 /**
407 * Signal that a request has been queued
408 */
409 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
410 __releases(fiq->lock);
411
412 /**
413 * Clean up when fuse_iqueue is destroyed
414 */
415 void (*release)(struct fuse_iqueue *fiq);
416 };
417
418 /** /dev/fuse input queue operations */
419 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
420
421 struct fuse_iqueue {
422 /** Connection established */
423 unsigned connected;
424
425 /** Lock protecting accesses to members of this structure */
426 spinlock_t lock;
427
428 /** Readers of the connection are waiting on this */
429 wait_queue_head_t waitq;
430
431 /** The next unique request id */
432 u64 reqctr;
433
434 /** The list of pending requests */
435 struct list_head pending;
436
437 /** Pending interrupts */
438 struct list_head interrupts;
439
440 /** Queue of pending forgets */
441 struct fuse_forget_link forget_list_head;
442 struct fuse_forget_link *forget_list_tail;
443
444 /** Batching of FORGET requests (positive indicates FORGET batch) */
445 int forget_batch;
446
447 /** O_ASYNC requests */
448 struct fasync_struct *fasync;
449
450 /** Device-specific callbacks */
451 const struct fuse_iqueue_ops *ops;
452
453 /** Device-specific state */
454 void *priv;
455 };
456
457 #define FUSE_PQ_HASH_BITS 8
458 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
459
460 struct fuse_pqueue {
461 /** Connection established */
462 unsigned connected;
463
464 /** Lock protecting accessess to members of this structure */
465 spinlock_t lock;
466
467 /** Hash table of requests being processed */
468 struct list_head *processing;
469
470 /** The list of requests under I/O */
471 struct list_head io;
472 };
473
474 /**
475 * Fuse device instance
476 */
477 struct fuse_dev {
478 /** Fuse connection for this device */
479 struct fuse_conn *fc;
480
481 /** Processing queue */
482 struct fuse_pqueue pq;
483
484 /** list entry on fc->devices */
485 struct list_head entry;
486 };
487
488 struct fuse_fs_context {
489 int fd;
490 unsigned int rootmode;
491 kuid_t user_id;
492 kgid_t group_id;
493 bool is_bdev:1;
494 bool fd_present:1;
495 bool rootmode_present:1;
496 bool user_id_present:1;
497 bool group_id_present:1;
498 bool default_permissions:1;
499 bool allow_other:1;
500 bool destroy:1;
501 bool no_control:1;
502 bool no_force_umount:1;
503 bool legacy_opts_show:1;
504 bool dax:1;
505 unsigned int max_read;
506 unsigned int blksize;
507 const char *subtype;
508
509 /* DAX device, may be NULL */
510 struct dax_device *dax_dev;
511
512 /* fuse_dev pointer to fill in, should contain NULL on entry */
513 void **fudptr;
514 };
515
516 /**
517 * A Fuse connection.
518 *
519 * This structure is created, when the root filesystem is mounted, and
520 * is destroyed, when the client device is closed and the last
521 * fuse_mount is destroyed.
522 */
523 struct fuse_conn {
524 /** Lock protecting accessess to members of this structure */
525 spinlock_t lock;
526
527 /** Refcount */
528 refcount_t count;
529
530 /** Number of fuse_dev's */
531 atomic_t dev_count;
532
533 struct rcu_head rcu;
534
535 /** The user id for this mount */
536 kuid_t user_id;
537
538 /** The group id for this mount */
539 kgid_t group_id;
540
541 /** The pid namespace for this mount */
542 struct pid_namespace *pid_ns;
543
544 /** The user namespace for this mount */
545 struct user_namespace *user_ns;
546
547 /** Maximum read size */
548 unsigned max_read;
549
550 /** Maximum write size */
551 unsigned max_write;
552
553 /** Maxmum number of pages that can be used in a single request */
554 unsigned int max_pages;
555
556 /** Input queue */
557 struct fuse_iqueue iq;
558
559 /** The next unique kernel file handle */
560 atomic64_t khctr;
561
562 /** rbtree of fuse_files waiting for poll events indexed by ph */
563 struct rb_root polled_files;
564
565 /** Maximum number of outstanding background requests */
566 unsigned max_background;
567
568 /** Number of background requests at which congestion starts */
569 unsigned congestion_threshold;
570
571 /** Number of requests currently in the background */
572 unsigned num_background;
573
574 /** Number of background requests currently queued for userspace */
575 unsigned active_background;
576
577 /** The list of background requests set aside for later queuing */
578 struct list_head bg_queue;
579
580 /** Protects: max_background, congestion_threshold, num_background,
581 * active_background, bg_queue, blocked */
582 spinlock_t bg_lock;
583
584 /** Flag indicating that INIT reply has been received. Allocating
585 * any fuse request will be suspended until the flag is set */
586 int initialized;
587
588 /** Flag indicating if connection is blocked. This will be
589 the case before the INIT reply is received, and if there
590 are too many outstading backgrounds requests */
591 int blocked;
592
593 /** waitq for blocked connection */
594 wait_queue_head_t blocked_waitq;
595
596 /** Connection established, cleared on umount, connection
597 abort and device release */
598 unsigned connected;
599
600 /** Connection aborted via sysfs */
601 bool aborted;
602
603 /** Connection failed (version mismatch). Cannot race with
604 setting other bitfields since it is only set once in INIT
605 reply, before any other request, and never cleared */
606 unsigned conn_error:1;
607
608 /** Connection successful. Only set in INIT */
609 unsigned conn_init:1;
610
611 /** Do readpages asynchronously? Only set in INIT */
612 unsigned async_read:1;
613
614 /** Return an unique read error after abort. Only set in INIT */
615 unsigned abort_err:1;
616
617 /** Do not send separate SETATTR request before open(O_TRUNC) */
618 unsigned atomic_o_trunc:1;
619
620 /** Filesystem supports NFS exporting. Only set in INIT */
621 unsigned export_support:1;
622
623 /** write-back cache policy (default is write-through) */
624 unsigned writeback_cache:1;
625
626 /** allow parallel lookups and readdir (default is serialized) */
627 unsigned parallel_dirops:1;
628
629 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
630 unsigned handle_killpriv:1;
631
632 /** cache READLINK responses in page cache */
633 unsigned cache_symlinks:1;
634
635 /* show legacy mount options */
636 unsigned int legacy_opts_show:1;
637
638 /*
639 * The following bitfields are only for optimization purposes
640 * and hence races in setting them will not cause malfunction
641 */
642
643 /** Is open/release not implemented by fs? */
644 unsigned no_open:1;
645
646 /** Is opendir/releasedir not implemented by fs? */
647 unsigned no_opendir:1;
648
649 /** Is fsync not implemented by fs? */
650 unsigned no_fsync:1;
651
652 /** Is fsyncdir not implemented by fs? */
653 unsigned no_fsyncdir:1;
654
655 /** Is flush not implemented by fs? */
656 unsigned no_flush:1;
657
658 /** Is setxattr not implemented by fs? */
659 unsigned no_setxattr:1;
660
661 /** Is getxattr not implemented by fs? */
662 unsigned no_getxattr:1;
663
664 /** Is listxattr not implemented by fs? */
665 unsigned no_listxattr:1;
666
667 /** Is removexattr not implemented by fs? */
668 unsigned no_removexattr:1;
669
670 /** Are posix file locking primitives not implemented by fs? */
671 unsigned no_lock:1;
672
673 /** Is access not implemented by fs? */
674 unsigned no_access:1;
675
676 /** Is create not implemented by fs? */
677 unsigned no_create:1;
678
679 /** Is interrupt not implemented by fs? */
680 unsigned no_interrupt:1;
681
682 /** Is bmap not implemented by fs? */
683 unsigned no_bmap:1;
684
685 /** Is poll not implemented by fs? */
686 unsigned no_poll:1;
687
688 /** Do multi-page cached writes */
689 unsigned big_writes:1;
690
691 /** Don't apply umask to creation modes */
692 unsigned dont_mask:1;
693
694 /** Are BSD file locking primitives not implemented by fs? */
695 unsigned no_flock:1;
696
697 /** Is fallocate not implemented by fs? */
698 unsigned no_fallocate:1;
699
700 /** Is rename with flags implemented by fs? */
701 unsigned no_rename2:1;
702
703 /** Use enhanced/automatic page cache invalidation. */
704 unsigned auto_inval_data:1;
705
706 /** Filesystem is fully reponsible for page cache invalidation. */
707 unsigned explicit_inval_data:1;
708
709 /** Does the filesystem support readdirplus? */
710 unsigned do_readdirplus:1;
711
712 /** Does the filesystem want adaptive readdirplus? */
713 unsigned readdirplus_auto:1;
714
715 /** Does the filesystem support asynchronous direct-IO submission? */
716 unsigned async_dio:1;
717
718 /** Is lseek not implemented by fs? */
719 unsigned no_lseek:1;
720
721 /** Does the filesystem support posix acls? */
722 unsigned posix_acl:1;
723
724 /** Check permissions based on the file mode or not? */
725 unsigned default_permissions:1;
726
727 /** Allow other than the mounter user to access the filesystem ? */
728 unsigned allow_other:1;
729
730 /** Does the filesystem support copy_file_range? */
731 unsigned no_copy_file_range:1;
732
733 /* Send DESTROY request */
734 unsigned int destroy:1;
735
736 /* Delete dentries that have gone stale */
737 unsigned int delete_stale:1;
738
739 /** Do not create entry in fusectl fs */
740 unsigned int no_control:1;
741
742 /** Do not allow MNT_FORCE umount */
743 unsigned int no_force_umount:1;
744
745 /* Auto-mount submounts announced by the server */
746 unsigned int auto_submounts:1;
747
748 /** The number of requests waiting for completion */
749 atomic_t num_waiting;
750
751 /** Negotiated minor version */
752 unsigned minor;
753
754 /** Entry on the fuse_mount_list */
755 struct list_head entry;
756
757 /** Device ID from the root super block */
758 dev_t dev;
759
760 /** Dentries in the control filesystem */
761 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
762
763 /** number of dentries used in the above array */
764 int ctl_ndents;
765
766 /** Key for lock owner ID scrambling */
767 u32 scramble_key[4];
768
769 /** Version counter for attribute changes */
770 atomic64_t attr_version;
771
772 /** Called on final put */
773 void (*release)(struct fuse_conn *);
774
775 /**
776 * Read/write semaphore to hold when accessing the sb of any
777 * fuse_mount belonging to this connection
778 */
779 struct rw_semaphore killsb;
780
781 /** List of device instances belonging to this connection */
782 struct list_head devices;
783
784 #ifdef CONFIG_FUSE_DAX
785 /* Dax specific conn data, non-NULL if DAX is enabled */
786 struct fuse_conn_dax *dax;
787 #endif
788
789 /** List of filesystems using this connection */
790 struct list_head mounts;
791 };
792
793 /*
794 * Represents a mounted filesystem, potentially a submount.
795 *
796 * This object allows sharing a fuse_conn between separate mounts to
797 * allow submounts with dedicated superblocks and thus separate device
798 * IDs.
799 */
800 struct fuse_mount {
801 /* Underlying (potentially shared) connection to the FUSE server */
802 struct fuse_conn *fc;
803
804 /* Refcount */
805 refcount_t count;
806
807 /*
808 * Super block for this connection (fc->killsb must be held when
809 * accessing this).
810 */
811 struct super_block *sb;
812
813 /* Entry on fc->mounts */
814 struct list_head fc_entry;
815 };
816
get_fuse_mount_super(struct super_block * sb)817 static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
818 {
819 return sb->s_fs_info;
820 }
821
get_fuse_conn_super(struct super_block * sb)822 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
823 {
824 struct fuse_mount *fm = get_fuse_mount_super(sb);
825
826 return fm ? fm->fc : NULL;
827 }
828
get_fuse_mount(struct inode * inode)829 static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
830 {
831 return get_fuse_mount_super(inode->i_sb);
832 }
833
get_fuse_conn(struct inode * inode)834 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
835 {
836 struct fuse_mount *fm = get_fuse_mount(inode);
837
838 return fm ? fm->fc : NULL;
839 }
840
get_fuse_inode(struct inode * inode)841 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
842 {
843 return container_of(inode, struct fuse_inode, inode);
844 }
845
get_node_id(struct inode * inode)846 static inline u64 get_node_id(struct inode *inode)
847 {
848 return get_fuse_inode(inode)->nodeid;
849 }
850
invalid_nodeid(u64 nodeid)851 static inline int invalid_nodeid(u64 nodeid)
852 {
853 return !nodeid || nodeid == FUSE_ROOT_ID;
854 }
855
fuse_get_attr_version(struct fuse_conn * fc)856 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
857 {
858 return atomic64_read(&fc->attr_version);
859 }
860
861 /** Device operations */
862 extern const struct file_operations fuse_dev_operations;
863
864 extern const struct dentry_operations fuse_dentry_operations;
865 extern const struct dentry_operations fuse_root_dentry_operations;
866
867 /**
868 * Get a filled in inode
869 */
870 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
871 int generation, struct fuse_attr *attr,
872 u64 attr_valid, u64 attr_version);
873
874 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
875 struct fuse_entry_out *outarg, struct inode **inode);
876
877 /**
878 * Send FORGET command
879 */
880 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
881 u64 nodeid, u64 nlookup);
882
883 struct fuse_forget_link *fuse_alloc_forget(void);
884
885 struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
886 unsigned int max,
887 unsigned int *countp);
888
889 /*
890 * Initialize READ or READDIR request
891 */
892 struct fuse_io_args {
893 union {
894 struct {
895 struct fuse_read_in in;
896 u64 attr_ver;
897 } read;
898 struct {
899 struct fuse_write_in in;
900 struct fuse_write_out out;
901 } write;
902 };
903 struct fuse_args_pages ap;
904 struct fuse_io_priv *io;
905 struct fuse_file *ff;
906 };
907
908 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
909 size_t count, int opcode);
910
911
912 /**
913 * Send OPEN or OPENDIR request
914 */
915 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
916
917 struct fuse_file *fuse_file_alloc(struct fuse_mount *fm);
918 void fuse_file_free(struct fuse_file *ff);
919 void fuse_finish_open(struct inode *inode, struct file *file);
920
921 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags);
922
923 /**
924 * Send RELEASE or RELEASEDIR request
925 */
926 void fuse_release_common(struct file *file, bool isdir);
927
928 /**
929 * Send FSYNC or FSYNCDIR request
930 */
931 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
932 int datasync, int opcode);
933
934 /**
935 * Notify poll wakeup
936 */
937 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
938 struct fuse_notify_poll_wakeup_out *outarg);
939
940 /**
941 * Initialize file operations on a regular file
942 */
943 void fuse_init_file_inode(struct inode *inode);
944
945 /**
946 * Initialize inode operations on regular files and special files
947 */
948 void fuse_init_common(struct inode *inode);
949
950 /**
951 * Initialize inode and file operations on a directory
952 */
953 void fuse_init_dir(struct inode *inode);
954
955 /**
956 * Initialize inode operations on a symlink
957 */
958 void fuse_init_symlink(struct inode *inode);
959
960 /**
961 * Change attributes of an inode
962 */
963 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
964 u64 attr_valid, u64 attr_version);
965
966 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
967 u64 attr_valid);
968
969 /**
970 * Initialize the client device
971 */
972 int fuse_dev_init(void);
973
974 /**
975 * Cleanup the client device
976 */
977 void fuse_dev_cleanup(void);
978
979 int fuse_ctl_init(void);
980 void __exit fuse_ctl_cleanup(void);
981
982 /**
983 * Simple request sending that does request allocation and freeing
984 */
985 ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args);
986 int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
987 gfp_t gfp_flags);
988
989 /**
990 * End a finished request
991 */
992 void fuse_request_end(struct fuse_req *req);
993
994 /* Abort all requests */
995 void fuse_abort_conn(struct fuse_conn *fc);
996 void fuse_wait_aborted(struct fuse_conn *fc);
997
998 /**
999 * Invalidate inode attributes
1000 */
1001 void fuse_invalidate_attr(struct inode *inode);
1002
1003 void fuse_invalidate_entry_cache(struct dentry *entry);
1004
1005 void fuse_invalidate_atime(struct inode *inode);
1006
1007 u64 entry_attr_timeout(struct fuse_entry_out *o);
1008 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
1009
1010 /**
1011 * Acquire reference to fuse_conn
1012 */
1013 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
1014
1015 /**
1016 * Initialize fuse_conn
1017 */
1018 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
1019 struct user_namespace *user_ns,
1020 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
1021
1022 /**
1023 * Release reference to fuse_conn
1024 */
1025 void fuse_conn_put(struct fuse_conn *fc);
1026
1027 /**
1028 * Acquire reference to fuse_mount
1029 */
1030 struct fuse_mount *fuse_mount_get(struct fuse_mount *fm);
1031
1032 /**
1033 * Release reference to fuse_mount
1034 */
1035 void fuse_mount_put(struct fuse_mount *fm);
1036
1037 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
1038 struct fuse_dev *fuse_dev_alloc(void);
1039 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
1040 void fuse_dev_free(struct fuse_dev *fud);
1041 void fuse_send_init(struct fuse_mount *fm);
1042
1043 /**
1044 * Fill in superblock and initialize fuse connection
1045 * @sb: partially-initialized superblock to fill in
1046 * @ctx: mount context
1047 */
1048 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
1049
1050 /*
1051 * Fill in superblock for submounts
1052 * @sb: partially-initialized superblock to fill in
1053 * @parent_fi: The fuse_inode of the parent filesystem where this submount is
1054 * mounted
1055 */
1056 int fuse_fill_super_submount(struct super_block *sb,
1057 struct fuse_inode *parent_fi);
1058
1059 /*
1060 * Remove the mount from the connection
1061 *
1062 * Returns whether this was the last mount
1063 */
1064 bool fuse_mount_remove(struct fuse_mount *fm);
1065
1066 /*
1067 * Shut down the connection (possibly sending DESTROY request).
1068 */
1069 void fuse_conn_destroy(struct fuse_mount *fm);
1070
1071 /**
1072 * Add connection to control filesystem
1073 */
1074 int fuse_ctl_add_conn(struct fuse_conn *fc);
1075
1076 /**
1077 * Remove connection from control filesystem
1078 */
1079 void fuse_ctl_remove_conn(struct fuse_conn *fc);
1080
1081 /**
1082 * Is file type valid?
1083 */
1084 int fuse_valid_type(int m);
1085
1086 bool fuse_invalid_attr(struct fuse_attr *attr);
1087
1088 /**
1089 * Is current process allowed to perform filesystem operation?
1090 */
1091 int fuse_allow_current_process(struct fuse_conn *fc);
1092
1093 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1094
1095 void fuse_update_ctime(struct inode *inode);
1096
1097 int fuse_update_attributes(struct inode *inode, struct file *file);
1098
1099 void fuse_flush_writepages(struct inode *inode);
1100
1101 void fuse_set_nowrite(struct inode *inode);
1102 void fuse_release_nowrite(struct inode *inode);
1103
1104 /**
1105 * Scan all fuse_mounts belonging to fc to find the first where
1106 * ilookup5() returns a result. Return that result and the
1107 * respective fuse_mount in *fm (unless fm is NULL).
1108 *
1109 * The caller must hold fc->killsb.
1110 */
1111 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
1112 struct fuse_mount **fm);
1113
1114 /**
1115 * File-system tells the kernel to invalidate cache for the given node id.
1116 */
1117 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
1118 loff_t offset, loff_t len);
1119
1120 /**
1121 * File-system tells the kernel to invalidate parent attributes and
1122 * the dentry matching parent/name.
1123 *
1124 * If the child_nodeid is non-zero and:
1125 * - matches the inode number for the dentry matching parent/name,
1126 * - is not a mount point
1127 * - is a file or oan empty directory
1128 * then the dentry is unhashed (d_delete()).
1129 */
1130 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
1131 u64 child_nodeid, struct qstr *name);
1132
1133 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
1134 bool isdir);
1135
1136 /**
1137 * fuse_direct_io() flags
1138 */
1139
1140 /** If set, it is WRITE; otherwise - READ */
1141 #define FUSE_DIO_WRITE (1 << 0)
1142
1143 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1144 #define FUSE_DIO_CUSE (1 << 1)
1145
1146 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1147 loff_t *ppos, int flags);
1148 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1149 unsigned int flags);
1150 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1151 unsigned long arg, unsigned int flags);
1152 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1153 int fuse_dev_release(struct inode *inode, struct file *file);
1154
1155 bool fuse_write_update_size(struct inode *inode, loff_t pos);
1156
1157 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1158 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1159
1160 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1161 struct file *file);
1162
1163 void fuse_set_initialized(struct fuse_conn *fc);
1164
1165 void fuse_unlock_inode(struct inode *inode, bool locked);
1166 bool fuse_lock_inode(struct inode *inode);
1167
1168 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1169 size_t size, int flags);
1170 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1171 size_t size);
1172 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1173 int fuse_removexattr(struct inode *inode, const char *name);
1174 extern const struct xattr_handler *fuse_xattr_handlers[];
1175 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1176 extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1177
1178 struct posix_acl;
1179 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
1180 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
1181
1182
1183 /* readdir.c */
1184 int fuse_readdir(struct file *file, struct dir_context *ctx);
1185
1186 /**
1187 * Return the number of bytes in an arguments list
1188 */
1189 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1190
1191 /**
1192 * Get the next unique ID for a request
1193 */
1194 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1195 void fuse_free_conn(struct fuse_conn *fc);
1196
1197 /* dax.c */
1198
1199 #define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
1200
1201 ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
1202 ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
1203 int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
1204 int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
1205 int fuse_dax_conn_alloc(struct fuse_conn *fc, struct dax_device *dax_dev);
1206 void fuse_dax_conn_free(struct fuse_conn *fc);
1207 bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
1208 void fuse_dax_inode_init(struct inode *inode);
1209 void fuse_dax_inode_cleanup(struct inode *inode);
1210 bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
1211 void fuse_dax_cancel_work(struct fuse_conn *fc);
1212
1213 #endif /* _FS_FUSE_I_H */
1214
