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 /* Bad inode */
176 FUSE_I_BAD,
177 };
178
179 struct fuse_conn;
180 struct fuse_mount;
181 struct fuse_release_args;
182
183 /**
184 * Reference to lower filesystem file for read/write operations handled in
185 * passthrough mode.
186 * This struct also tracks the credentials to be used for handling read/write
187 * operations.
188 */
189 struct fuse_passthrough {
190 struct file *filp;
191 struct cred *cred;
192 };
193
194 /** FUSE specific file data */
195 struct fuse_file {
196 /** Fuse connection for this file */
197 struct fuse_mount *fm;
198
199 /* Argument space reserved for release */
200 struct fuse_release_args *release_args;
201
202 /** Kernel file handle guaranteed to be unique */
203 u64 kh;
204
205 /** File handle used by userspace */
206 u64 fh;
207
208 /** Node id of this file */
209 u64 nodeid;
210
211 /** Refcount */
212 refcount_t count;
213
214 /** FOPEN_* flags returned by open */
215 u32 open_flags;
216
217 /** Entry on inode's write_files list */
218 struct list_head write_entry;
219
220 /* Readdir related */
221 struct {
222 /*
223 * Protects below fields against (crazy) parallel readdir on
224 * same open file. Uncontended in the normal case.
225 */
226 struct mutex lock;
227
228 /* Dir stream position */
229 loff_t pos;
230
231 /* Offset in cache */
232 loff_t cache_off;
233
234 /* Version of cache we are reading */
235 u64 version;
236
237 } readdir;
238
239 /** Container for data related to the passthrough functionality */
240 struct fuse_passthrough passthrough;
241
242 /** RB node to be linked on fuse_conn->polled_files */
243 struct rb_node polled_node;
244
245 /** Wait queue head for poll */
246 wait_queue_head_t poll_wait;
247
248 /** Has flock been performed on this file? */
249 bool flock:1;
250 };
251
252 /** One input argument of a request */
253 struct fuse_in_arg {
254 unsigned size;
255 const void *value;
256 };
257
258 /** One output argument of a request */
259 struct fuse_arg {
260 unsigned size;
261 void *value;
262 };
263
264 /** FUSE page descriptor */
265 struct fuse_page_desc {
266 unsigned int length;
267 unsigned int offset;
268 };
269
270 struct fuse_args {
271 uint64_t nodeid;
272 uint32_t opcode;
273 unsigned short in_numargs;
274 unsigned short out_numargs;
275 bool force:1;
276 bool noreply:1;
277 bool nocreds:1;
278 bool in_pages:1;
279 bool out_pages:1;
280 bool user_pages:1;
281 bool out_argvar:1;
282 bool page_zeroing:1;
283 bool page_replace:1;
284 bool may_block:1;
285 struct fuse_in_arg in_args[3];
286 struct fuse_arg out_args[2];
287 void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
288
289 /* Path used for completing d_canonical_path */
290 struct path *canonical_path;
291 };
292
293 struct fuse_args_pages {
294 struct fuse_args args;
295 struct page **pages;
296 struct fuse_page_desc *descs;
297 unsigned int num_pages;
298 };
299
300 #define FUSE_ARGS(args) struct fuse_args args = {}
301
302 /** The request IO state (for asynchronous processing) */
303 struct fuse_io_priv {
304 struct kref refcnt;
305 int async;
306 spinlock_t lock;
307 unsigned reqs;
308 ssize_t bytes;
309 size_t size;
310 __u64 offset;
311 bool write;
312 bool should_dirty;
313 int err;
314 struct kiocb *iocb;
315 struct completion *done;
316 bool blocking;
317 };
318
319 #define FUSE_IO_PRIV_SYNC(i) \
320 { \
321 .refcnt = KREF_INIT(1), \
322 .async = 0, \
323 .iocb = i, \
324 }
325
326 /**
327 * Request flags
328 *
329 * FR_ISREPLY: set if the request has reply
330 * FR_FORCE: force sending of the request even if interrupted
331 * FR_BACKGROUND: request is sent in the background
332 * FR_WAITING: request is counted as "waiting"
333 * FR_ABORTED: the request was aborted
334 * FR_INTERRUPTED: the request has been interrupted
335 * FR_LOCKED: data is being copied to/from the request
336 * FR_PENDING: request is not yet in userspace
337 * FR_SENT: request is in userspace, waiting for an answer
338 * FR_FINISHED: request is finished
339 * FR_PRIVATE: request is on private list
340 * FR_ASYNC: request is asynchronous
341 */
342 enum fuse_req_flag {
343 FR_ISREPLY,
344 FR_FORCE,
345 FR_BACKGROUND,
346 FR_WAITING,
347 FR_ABORTED,
348 FR_INTERRUPTED,
349 FR_LOCKED,
350 FR_PENDING,
351 FR_SENT,
352 FR_FINISHED,
353 FR_PRIVATE,
354 FR_ASYNC,
355 };
356
357 /**
358 * A request to the client
359 *
360 * .waitq.lock protects the following fields:
361 * - FR_ABORTED
362 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
363 */
364 struct fuse_req {
365 /** This can be on either pending processing or io lists in
366 fuse_conn */
367 struct list_head list;
368
369 /** Entry on the interrupts list */
370 struct list_head intr_entry;
371
372 /* Input/output arguments */
373 struct fuse_args *args;
374
375 /** refcount */
376 refcount_t count;
377
378 /* Request flags, updated with test/set/clear_bit() */
379 unsigned long flags;
380
381 /* The request input header */
382 struct {
383 struct fuse_in_header h;
384 } in;
385
386 /* The request output header */
387 struct {
388 struct fuse_out_header h;
389 } out;
390
391 /** Used to wake up the task waiting for completion of request*/
392 wait_queue_head_t waitq;
393
394 /** virtio-fs's physically contiguous buffer for in and out args */
395 void *argbuf;
396
397 /** fuse_mount this request belongs to */
398 struct fuse_mount *fm;
399 };
400
401 struct fuse_iqueue;
402
403 /**
404 * Input queue callbacks
405 *
406 * Input queue signalling is device-specific. For example, the /dev/fuse file
407 * uses fiq->waitq and fasync to wake processes that are waiting on queue
408 * readiness. These callbacks allow other device types to respond to input
409 * queue activity.
410 */
411 struct fuse_iqueue_ops {
412 /**
413 * Signal that a forget has been queued
414 */
415 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq, bool sync)
416 __releases(fiq->lock);
417
418 /**
419 * Signal that an INTERRUPT request has been queued
420 */
421 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq, bool sync)
422 __releases(fiq->lock);
423
424 /**
425 * Signal that a request has been queued
426 */
427 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq, bool sync)
428 __releases(fiq->lock);
429
430 /**
431 * Clean up when fuse_iqueue is destroyed
432 */
433 void (*release)(struct fuse_iqueue *fiq);
434 };
435
436 /** /dev/fuse input queue operations */
437 extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
438
439 struct fuse_iqueue {
440 /** Connection established */
441 unsigned connected;
442
443 /** Lock protecting accesses to members of this structure */
444 spinlock_t lock;
445
446 /** Readers of the connection are waiting on this */
447 wait_queue_head_t waitq;
448
449 /** The next unique request id */
450 u64 reqctr;
451
452 /** The list of pending requests */
453 struct list_head pending;
454
455 /** Pending interrupts */
456 struct list_head interrupts;
457
458 /** Queue of pending forgets */
459 struct fuse_forget_link forget_list_head;
460 struct fuse_forget_link *forget_list_tail;
461
462 /** Batching of FORGET requests (positive indicates FORGET batch) */
463 int forget_batch;
464
465 /** O_ASYNC requests */
466 struct fasync_struct *fasync;
467
468 /** Device-specific callbacks */
469 const struct fuse_iqueue_ops *ops;
470
471 /** Device-specific state */
472 void *priv;
473 };
474
475 #define FUSE_PQ_HASH_BITS 8
476 #define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
477
478 struct fuse_pqueue {
479 /** Connection established */
480 unsigned connected;
481
482 /** Lock protecting accessess to members of this structure */
483 spinlock_t lock;
484
485 /** Hash table of requests being processed */
486 struct list_head *processing;
487
488 /** The list of requests under I/O */
489 struct list_head io;
490 };
491
492 /**
493 * Fuse device instance
494 */
495 struct fuse_dev {
496 /** Fuse connection for this device */
497 struct fuse_conn *fc;
498
499 /** Processing queue */
500 struct fuse_pqueue pq;
501
502 /** list entry on fc->devices */
503 struct list_head entry;
504 };
505
506 struct fuse_fs_context {
507 int fd;
508 unsigned int rootmode;
509 kuid_t user_id;
510 kgid_t group_id;
511 bool is_bdev:1;
512 bool fd_present:1;
513 bool rootmode_present:1;
514 bool user_id_present:1;
515 bool group_id_present:1;
516 bool default_permissions:1;
517 bool allow_other:1;
518 bool destroy:1;
519 bool no_control:1;
520 bool no_force_umount:1;
521 bool legacy_opts_show:1;
522 bool dax:1;
523 unsigned int max_read;
524 unsigned int blksize;
525 const char *subtype;
526
527 /* DAX device, may be NULL */
528 struct dax_device *dax_dev;
529
530 /* fuse_dev pointer to fill in, should contain NULL on entry */
531 void **fudptr;
532 };
533
534 /**
535 * A Fuse connection.
536 *
537 * This structure is created, when the root filesystem is mounted, and
538 * is destroyed, when the client device is closed and the last
539 * fuse_mount is destroyed.
540 */
541 struct fuse_conn {
542 /** Lock protecting accessess to members of this structure */
543 spinlock_t lock;
544
545 /** Refcount */
546 refcount_t count;
547
548 /** Number of fuse_dev's */
549 atomic_t dev_count;
550
551 struct rcu_head rcu;
552
553 /** The user id for this mount */
554 kuid_t user_id;
555
556 /** The group id for this mount */
557 kgid_t group_id;
558
559 /** The pid namespace for this mount */
560 struct pid_namespace *pid_ns;
561
562 /** The user namespace for this mount */
563 struct user_namespace *user_ns;
564
565 /** Maximum read size */
566 unsigned max_read;
567
568 /** Maximum write size */
569 unsigned max_write;
570
571 /** Maxmum number of pages that can be used in a single request */
572 unsigned int max_pages;
573
574 /** Input queue */
575 struct fuse_iqueue iq;
576
577 /** The next unique kernel file handle */
578 atomic64_t khctr;
579
580 /** rbtree of fuse_files waiting for poll events indexed by ph */
581 struct rb_root polled_files;
582
583 /** Maximum number of outstanding background requests */
584 unsigned max_background;
585
586 /** Number of background requests at which congestion starts */
587 unsigned congestion_threshold;
588
589 /** Number of requests currently in the background */
590 unsigned num_background;
591
592 /** Number of background requests currently queued for userspace */
593 unsigned active_background;
594
595 /** The list of background requests set aside for later queuing */
596 struct list_head bg_queue;
597
598 /** Protects: max_background, congestion_threshold, num_background,
599 * active_background, bg_queue, blocked */
600 spinlock_t bg_lock;
601
602 /** Flag indicating that INIT reply has been received. Allocating
603 * any fuse request will be suspended until the flag is set */
604 int initialized;
605
606 /** Flag indicating if connection is blocked. This will be
607 the case before the INIT reply is received, and if there
608 are too many outstading backgrounds requests */
609 int blocked;
610
611 /** waitq for blocked connection */
612 wait_queue_head_t blocked_waitq;
613
614 /** Connection established, cleared on umount, connection
615 abort and device release */
616 unsigned connected;
617
618 /** Connection aborted via sysfs */
619 bool aborted;
620
621 /** Connection failed (version mismatch). Cannot race with
622 setting other bitfields since it is only set once in INIT
623 reply, before any other request, and never cleared */
624 unsigned conn_error:1;
625
626 /** Connection successful. Only set in INIT */
627 unsigned conn_init:1;
628
629 /** Do readpages asynchronously? Only set in INIT */
630 unsigned async_read:1;
631
632 /** Return an unique read error after abort. Only set in INIT */
633 unsigned abort_err:1;
634
635 /** Do not send separate SETATTR request before open(O_TRUNC) */
636 unsigned atomic_o_trunc:1;
637
638 /** Filesystem supports NFS exporting. Only set in INIT */
639 unsigned export_support:1;
640
641 /** write-back cache policy (default is write-through) */
642 unsigned writeback_cache:1;
643
644 /** allow parallel lookups and readdir (default is serialized) */
645 unsigned parallel_dirops:1;
646
647 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
648 unsigned handle_killpriv:1;
649
650 /** cache READLINK responses in page cache */
651 unsigned cache_symlinks:1;
652
653 /* show legacy mount options */
654 unsigned int legacy_opts_show:1;
655
656 /*
657 * The following bitfields are only for optimization purposes
658 * and hence races in setting them will not cause malfunction
659 */
660
661 /** Is open/release not implemented by fs? */
662 unsigned no_open:1;
663
664 /** Is opendir/releasedir not implemented by fs? */
665 unsigned no_opendir:1;
666
667 /** Is fsync not implemented by fs? */
668 unsigned no_fsync:1;
669
670 /** Is fsyncdir not implemented by fs? */
671 unsigned no_fsyncdir:1;
672
673 /** Is flush not implemented by fs? */
674 unsigned no_flush:1;
675
676 /** Is setxattr not implemented by fs? */
677 unsigned no_setxattr:1;
678
679 /** Is getxattr not implemented by fs? */
680 unsigned no_getxattr:1;
681
682 /** Is listxattr not implemented by fs? */
683 unsigned no_listxattr:1;
684
685 /** Is removexattr not implemented by fs? */
686 unsigned no_removexattr:1;
687
688 /** Are posix file locking primitives not implemented by fs? */
689 unsigned no_lock:1;
690
691 /** Is access not implemented by fs? */
692 unsigned no_access:1;
693
694 /** Is create not implemented by fs? */
695 unsigned no_create:1;
696
697 /** Is interrupt not implemented by fs? */
698 unsigned no_interrupt:1;
699
700 /** Is bmap not implemented by fs? */
701 unsigned no_bmap:1;
702
703 /** Is poll not implemented by fs? */
704 unsigned no_poll:1;
705
706 /** Do multi-page cached writes */
707 unsigned big_writes:1;
708
709 /** Don't apply umask to creation modes */
710 unsigned dont_mask:1;
711
712 /** Are BSD file locking primitives not implemented by fs? */
713 unsigned no_flock:1;
714
715 /** Is fallocate not implemented by fs? */
716 unsigned no_fallocate:1;
717
718 /** Is rename with flags implemented by fs? */
719 unsigned no_rename2:1;
720
721 /** Use enhanced/automatic page cache invalidation. */
722 unsigned auto_inval_data:1;
723
724 /** Filesystem is fully reponsible for page cache invalidation. */
725 unsigned explicit_inval_data:1;
726
727 /** Does the filesystem support readdirplus? */
728 unsigned do_readdirplus:1;
729
730 /** Does the filesystem want adaptive readdirplus? */
731 unsigned readdirplus_auto:1;
732
733 /** Does the filesystem support asynchronous direct-IO submission? */
734 unsigned async_dio:1;
735
736 /** Is lseek not implemented by fs? */
737 unsigned no_lseek:1;
738
739 /** Does the filesystem support posix acls? */
740 unsigned posix_acl:1;
741
742 /** Check permissions based on the file mode or not? */
743 unsigned default_permissions:1;
744
745 /** Allow other than the mounter user to access the filesystem ? */
746 unsigned allow_other:1;
747
748 /** Does the filesystem support copy_file_range? */
749 unsigned no_copy_file_range:1;
750
751 /* Send DESTROY request */
752 unsigned int destroy:1;
753
754 /* Delete dentries that have gone stale */
755 unsigned int delete_stale:1;
756
757 /** Do not create entry in fusectl fs */
758 unsigned int no_control:1;
759
760 /** Do not allow MNT_FORCE umount */
761 unsigned int no_force_umount:1;
762
763 /* Auto-mount submounts announced by the server */
764 unsigned int auto_submounts:1;
765
766 /** Passthrough mode for read/write IO */
767 unsigned int passthrough:1;
768
769 /** The number of requests waiting for completion */
770 atomic_t num_waiting;
771
772 /** Negotiated minor version */
773 unsigned minor;
774
775 /** Entry on the fuse_mount_list */
776 struct list_head entry;
777
778 /** Device ID from the root super block */
779 dev_t dev;
780
781 /** Dentries in the control filesystem */
782 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
783
784 /** number of dentries used in the above array */
785 int ctl_ndents;
786
787 /** Key for lock owner ID scrambling */
788 u32 scramble_key[4];
789
790 /** Version counter for attribute changes */
791 atomic64_t attr_version;
792
793 /** Called on final put */
794 void (*release)(struct fuse_conn *);
795
796 /**
797 * Read/write semaphore to hold when accessing the sb of any
798 * fuse_mount belonging to this connection
799 */
800 struct rw_semaphore killsb;
801
802 /** List of device instances belonging to this connection */
803 struct list_head devices;
804
805 #ifdef CONFIG_FUSE_DAX
806 /* Dax specific conn data, non-NULL if DAX is enabled */
807 struct fuse_conn_dax *dax;
808 #endif
809
810 /** List of filesystems using this connection */
811 struct list_head mounts;
812
813 /** IDR for passthrough requests */
814 struct idr passthrough_req;
815
816 /** Protects passthrough_req */
817 spinlock_t passthrough_req_lock;
818 };
819
820 /*
821 * Represents a mounted filesystem, potentially a submount.
822 *
823 * This object allows sharing a fuse_conn between separate mounts to
824 * allow submounts with dedicated superblocks and thus separate device
825 * IDs.
826 */
827 struct fuse_mount {
828 /* Underlying (potentially shared) connection to the FUSE server */
829 struct fuse_conn *fc;
830
831 /* Refcount */
832 refcount_t count;
833
834 /*
835 * Super block for this connection (fc->killsb must be held when
836 * accessing this).
837 */
838 struct super_block *sb;
839
840 /* Entry on fc->mounts */
841 struct list_head fc_entry;
842 };
843
get_fuse_mount_super(struct super_block * sb)844 static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
845 {
846 return sb->s_fs_info;
847 }
848
get_fuse_conn_super(struct super_block * sb)849 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
850 {
851 struct fuse_mount *fm = get_fuse_mount_super(sb);
852
853 return fm ? fm->fc : NULL;
854 }
855
get_fuse_mount(struct inode * inode)856 static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
857 {
858 return get_fuse_mount_super(inode->i_sb);
859 }
860
get_fuse_conn(struct inode * inode)861 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
862 {
863 struct fuse_mount *fm = get_fuse_mount(inode);
864
865 return fm ? fm->fc : NULL;
866 }
867
get_fuse_inode(struct inode * inode)868 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
869 {
870 return container_of(inode, struct fuse_inode, inode);
871 }
872
get_node_id(struct inode * inode)873 static inline u64 get_node_id(struct inode *inode)
874 {
875 return get_fuse_inode(inode)->nodeid;
876 }
877
invalid_nodeid(u64 nodeid)878 static inline int invalid_nodeid(u64 nodeid)
879 {
880 return !nodeid || nodeid == FUSE_ROOT_ID;
881 }
882
fuse_get_attr_version(struct fuse_conn * fc)883 static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
884 {
885 return atomic64_read(&fc->attr_version);
886 }
887
fuse_stale_inode(const struct inode * inode,int generation,struct fuse_attr * attr)888 static inline bool fuse_stale_inode(const struct inode *inode, int generation,
889 struct fuse_attr *attr)
890 {
891 return inode->i_generation != generation ||
892 inode_wrong_type(inode, attr->mode);
893 }
894
fuse_make_bad(struct inode * inode)895 static inline void fuse_make_bad(struct inode *inode)
896 {
897 remove_inode_hash(inode);
898 set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
899 }
900
fuse_is_bad(struct inode * inode)901 static inline bool fuse_is_bad(struct inode *inode)
902 {
903 return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
904 }
905
906 /** Device operations */
907 extern const struct file_operations fuse_dev_operations;
908
909 extern const struct dentry_operations fuse_dentry_operations;
910 extern const struct dentry_operations fuse_root_dentry_operations;
911
912 /**
913 * Get a filled in inode
914 */
915 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
916 int generation, struct fuse_attr *attr,
917 u64 attr_valid, u64 attr_version);
918
919 int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
920 struct fuse_entry_out *outarg, struct inode **inode);
921
922 /**
923 * Send FORGET command
924 */
925 void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
926 u64 nodeid, u64 nlookup);
927
928 struct fuse_forget_link *fuse_alloc_forget(void);
929
930 struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
931 unsigned int max,
932 unsigned int *countp);
933
934 /*
935 * Initialize READ or READDIR request
936 */
937 struct fuse_io_args {
938 union {
939 struct {
940 struct fuse_read_in in;
941 u64 attr_ver;
942 } read;
943 struct {
944 struct fuse_write_in in;
945 struct fuse_write_out out;
946 bool page_locked;
947 } write;
948 };
949 struct fuse_args_pages ap;
950 struct fuse_io_priv *io;
951 struct fuse_file *ff;
952 };
953
954 void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
955 size_t count, int opcode);
956
957
958 /**
959 * Send OPEN or OPENDIR request
960 */
961 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
962
963 struct fuse_file *fuse_file_alloc(struct fuse_mount *fm);
964 void fuse_file_free(struct fuse_file *ff);
965 void fuse_finish_open(struct inode *inode, struct file *file);
966
967 void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff, int flags);
968
969 /**
970 * Send RELEASE or RELEASEDIR request
971 */
972 void fuse_release_common(struct file *file, bool isdir);
973
974 /**
975 * Send FSYNC or FSYNCDIR request
976 */
977 int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
978 int datasync, int opcode);
979
980 /**
981 * Notify poll wakeup
982 */
983 int fuse_notify_poll_wakeup(struct fuse_conn *fc,
984 struct fuse_notify_poll_wakeup_out *outarg);
985
986 /**
987 * Initialize file operations on a regular file
988 */
989 void fuse_init_file_inode(struct inode *inode);
990
991 /**
992 * Initialize inode operations on regular files and special files
993 */
994 void fuse_init_common(struct inode *inode);
995
996 /**
997 * Initialize inode and file operations on a directory
998 */
999 void fuse_init_dir(struct inode *inode);
1000
1001 /**
1002 * Initialize inode operations on a symlink
1003 */
1004 void fuse_init_symlink(struct inode *inode);
1005
1006 /**
1007 * Change attributes of an inode
1008 */
1009 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
1010 u64 attr_valid, u64 attr_version);
1011
1012 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
1013 u64 attr_valid);
1014
1015 /**
1016 * Initialize the client device
1017 */
1018 int fuse_dev_init(void);
1019
1020 /**
1021 * Cleanup the client device
1022 */
1023 void fuse_dev_cleanup(void);
1024
1025 int fuse_ctl_init(void);
1026 void __exit fuse_ctl_cleanup(void);
1027
1028 /**
1029 * Simple request sending that does request allocation and freeing
1030 */
1031 ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args);
1032 int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
1033 gfp_t gfp_flags);
1034
1035 /**
1036 * End a finished request
1037 */
1038 void fuse_request_end(struct fuse_req *req);
1039
1040 /* Abort all requests */
1041 void fuse_abort_conn(struct fuse_conn *fc);
1042 void fuse_wait_aborted(struct fuse_conn *fc);
1043
1044 /**
1045 * Invalidate inode attributes
1046 */
1047 void fuse_invalidate_attr(struct inode *inode);
1048
1049 void fuse_invalidate_entry_cache(struct dentry *entry);
1050
1051 void fuse_invalidate_atime(struct inode *inode);
1052
1053 u64 entry_attr_timeout(struct fuse_entry_out *o);
1054 void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
1055
1056 /**
1057 * Acquire reference to fuse_conn
1058 */
1059 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
1060
1061 /**
1062 * Initialize fuse_conn
1063 */
1064 void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
1065 struct user_namespace *user_ns,
1066 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
1067
1068 /**
1069 * Release reference to fuse_conn
1070 */
1071 void fuse_conn_put(struct fuse_conn *fc);
1072
1073 /**
1074 * Acquire reference to fuse_mount
1075 */
1076 struct fuse_mount *fuse_mount_get(struct fuse_mount *fm);
1077
1078 /**
1079 * Release reference to fuse_mount
1080 */
1081 void fuse_mount_put(struct fuse_mount *fm);
1082
1083 struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
1084 struct fuse_dev *fuse_dev_alloc(void);
1085 void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
1086 void fuse_dev_free(struct fuse_dev *fud);
1087 void fuse_send_init(struct fuse_mount *fm);
1088
1089 /**
1090 * Fill in superblock and initialize fuse connection
1091 * @sb: partially-initialized superblock to fill in
1092 * @ctx: mount context
1093 */
1094 int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
1095
1096 /*
1097 * Fill in superblock for submounts
1098 * @sb: partially-initialized superblock to fill in
1099 * @parent_fi: The fuse_inode of the parent filesystem where this submount is
1100 * mounted
1101 */
1102 int fuse_fill_super_submount(struct super_block *sb,
1103 struct fuse_inode *parent_fi);
1104
1105 /*
1106 * Remove the mount from the connection
1107 *
1108 * Returns whether this was the last mount
1109 */
1110 bool fuse_mount_remove(struct fuse_mount *fm);
1111
1112 /*
1113 * Shut down the connection (possibly sending DESTROY request).
1114 */
1115 void fuse_conn_destroy(struct fuse_mount *fm);
1116
1117 /**
1118 * Add connection to control filesystem
1119 */
1120 int fuse_ctl_add_conn(struct fuse_conn *fc);
1121
1122 /**
1123 * Remove connection from control filesystem
1124 */
1125 void fuse_ctl_remove_conn(struct fuse_conn *fc);
1126
1127 /**
1128 * Is file type valid?
1129 */
1130 int fuse_valid_type(int m);
1131
1132 bool fuse_invalid_attr(struct fuse_attr *attr);
1133
1134 /**
1135 * Is current process allowed to perform filesystem operation?
1136 */
1137 int fuse_allow_current_process(struct fuse_conn *fc);
1138
1139 u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1140
1141 void fuse_flush_time_update(struct inode *inode);
1142 void fuse_update_ctime(struct inode *inode);
1143
1144 int fuse_update_attributes(struct inode *inode, struct file *file);
1145
1146 void fuse_flush_writepages(struct inode *inode);
1147
1148 void fuse_set_nowrite(struct inode *inode);
1149 void fuse_release_nowrite(struct inode *inode);
1150
1151 /**
1152 * Scan all fuse_mounts belonging to fc to find the first where
1153 * ilookup5() returns a result. Return that result and the
1154 * respective fuse_mount in *fm (unless fm is NULL).
1155 *
1156 * The caller must hold fc->killsb.
1157 */
1158 struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
1159 struct fuse_mount **fm);
1160
1161 /**
1162 * File-system tells the kernel to invalidate cache for the given node id.
1163 */
1164 int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
1165 loff_t offset, loff_t len);
1166
1167 /**
1168 * File-system tells the kernel to invalidate parent attributes and
1169 * the dentry matching parent/name.
1170 *
1171 * If the child_nodeid is non-zero and:
1172 * - matches the inode number for the dentry matching parent/name,
1173 * - is not a mount point
1174 * - is a file or oan empty directory
1175 * then the dentry is unhashed (d_delete()).
1176 */
1177 int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
1178 u64 child_nodeid, struct qstr *name);
1179
1180 int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
1181 bool isdir);
1182
1183 /**
1184 * fuse_direct_io() flags
1185 */
1186
1187 /** If set, it is WRITE; otherwise - READ */
1188 #define FUSE_DIO_WRITE (1 << 0)
1189
1190 /** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1191 #define FUSE_DIO_CUSE (1 << 1)
1192
1193 ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1194 loff_t *ppos, int flags);
1195 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1196 unsigned int flags);
1197 long fuse_ioctl_common(struct file *file, unsigned int cmd,
1198 unsigned long arg, unsigned int flags);
1199 __poll_t fuse_file_poll(struct file *file, poll_table *wait);
1200 int fuse_dev_release(struct inode *inode, struct file *file);
1201
1202 bool fuse_write_update_size(struct inode *inode, loff_t pos);
1203
1204 int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1205 int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1206
1207 int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1208 struct file *file);
1209
1210 void fuse_set_initialized(struct fuse_conn *fc);
1211
1212 void fuse_unlock_inode(struct inode *inode, bool locked);
1213 bool fuse_lock_inode(struct inode *inode);
1214
1215 int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1216 size_t size, int flags);
1217 ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1218 size_t size);
1219 ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1220 int fuse_removexattr(struct inode *inode, const char *name);
1221 extern const struct xattr_handler *fuse_xattr_handlers[];
1222 extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1223 extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1224
1225 struct posix_acl;
1226 struct posix_acl *fuse_get_acl(struct inode *inode, int type);
1227 int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type);
1228
1229
1230 /* readdir.c */
1231 int fuse_readdir(struct file *file, struct dir_context *ctx);
1232
1233 /**
1234 * Return the number of bytes in an arguments list
1235 */
1236 unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1237
1238 /**
1239 * Get the next unique ID for a request
1240 */
1241 u64 fuse_get_unique(struct fuse_iqueue *fiq);
1242 void fuse_free_conn(struct fuse_conn *fc);
1243
1244 /* dax.c */
1245
1246 #define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
1247
1248 ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
1249 ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
1250 int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
1251 int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
1252 int fuse_dax_conn_alloc(struct fuse_conn *fc, struct dax_device *dax_dev);
1253 void fuse_dax_conn_free(struct fuse_conn *fc);
1254 bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
1255 void fuse_dax_inode_init(struct inode *inode);
1256 void fuse_dax_inode_cleanup(struct inode *inode);
1257 bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
1258 void fuse_dax_cancel_work(struct fuse_conn *fc);
1259
1260 /* passthrough.c */
1261 int fuse_passthrough_open(struct fuse_dev *fud, u32 lower_fd);
1262 int fuse_passthrough_setup(struct fuse_conn *fc, struct fuse_file *ff,
1263 struct fuse_open_out *openarg);
1264 void fuse_passthrough_release(struct fuse_passthrough *passthrough);
1265 ssize_t fuse_passthrough_read_iter(struct kiocb *iocb, struct iov_iter *to);
1266 ssize_t fuse_passthrough_write_iter(struct kiocb *iocb, struct iov_iter *from);
1267 ssize_t fuse_passthrough_mmap(struct file *file, struct vm_area_struct *vma);
1268
1269 #endif /* _FS_FUSE_I_H */
1270