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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#include <linux/fuse.h>
13#include <linux/fs.h>
14#include <linux/mount.h>
15#include <linux/wait.h>
16#include <linux/list.h>
17#include <linux/spinlock.h>
18#include <linux/mm.h>
19#include <linux/backing-dev.h>
20#include <linux/mutex.h>
21#include <linux/rwsem.h>
22#include <linux/rbtree.h>
23#include <linux/poll.h>
24#include <linux/workqueue.h>
25
26/** Max number of pages that can be used in a single read request */
27#define FUSE_MAX_PAGES_PER_REQ 32
28
29/** Bias for fi->writectr, meaning new writepages must not be sent */
30#define FUSE_NOWRITE INT_MIN
31
32/** It could be as large as PATH_MAX, but would that have any uses? */
33#define FUSE_NAME_MAX 1024
34
35/** Number of dentries for each connection in the control filesystem */
36#define FUSE_CTL_NUM_DENTRIES 5
37
38/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
39 module will check permissions based on the file mode. Otherwise no
40 permission checking is done in the kernel */
41#define FUSE_DEFAULT_PERMISSIONS (1 << 0)
42
43/** If the FUSE_ALLOW_OTHER flag is given, then not only the user
44 doing the mount will be allowed to access the filesystem */
45#define FUSE_ALLOW_OTHER (1 << 1)
46
47/** List of active connections */
48extern struct list_head fuse_conn_list;
49
50/** Global mutex protecting fuse_conn_list and the control filesystem */
51extern struct mutex fuse_mutex;
52
53/** Module parameters */
54extern unsigned max_user_bgreq;
55extern unsigned max_user_congthresh;
56
57/* One forget request */
58struct fuse_forget_link {
59 struct fuse_forget_one forget_one;
60 struct fuse_forget_link *next;
61};
62
63/** FUSE inode */
64struct fuse_inode {
65 /** Inode data */
66 struct inode inode;
67
68 /** Unique ID, which identifies the inode between userspace
69 * and kernel */
70 u64 nodeid;
71
72 /** Number of lookups on this inode */
73 u64 nlookup;
74
75 /** The request used for sending the FORGET message */
76 struct fuse_forget_link *forget;
77
78 /** Time in jiffies until the file attributes are valid */
79 u64 i_time;
80
81 /** The sticky bit in inode->i_mode may have been removed, so
82 preserve the original mode */
83 umode_t orig_i_mode;
84
85 /** 64 bit inode number */
86 u64 orig_ino;
87
88 /** Version of last attribute change */
89 u64 attr_version;
90
91 /** Files usable in writepage. Protected by fc->lock */
92 struct list_head write_files;
93
94 /** Writepages pending on truncate or fsync */
95 struct list_head queued_writes;
96
97 /** Number of sent writes, a negative bias (FUSE_NOWRITE)
98 * means more writes are blocked */
99 int writectr;
100
101 /** Waitq for writepage completion */
102 wait_queue_head_t page_waitq;
103
104 /** List of writepage requestst (pending or sent) */
105 struct list_head writepages;
106};
107
108struct fuse_conn;
109
110/** FUSE specific file data */
111struct fuse_file {
112 /** Fuse connection for this file */
113 struct fuse_conn *fc;
114
115 /** Request reserved for flush and release */
116 struct fuse_req *reserved_req;
117
118 /** Kernel file handle guaranteed to be unique */
119 u64 kh;
120
121 /** File handle used by userspace */
122 u64 fh;
123
124 /** Node id of this file */
125 u64 nodeid;
126
127 /** Refcount */
128 atomic_t count;
129
130 /** FOPEN_* flags returned by open */
131 u32 open_flags;
132
133 /** Entry on inode's write_files list */
134 struct list_head write_entry;
135
136 /** RB node to be linked on fuse_conn->polled_files */
137 struct rb_node polled_node;
138
139 /** Wait queue head for poll */
140 wait_queue_head_t poll_wait;
141
142 /** Has flock been performed on this file? */
143 bool flock:1;
144};
145
146/** One input argument of a request */
147struct fuse_in_arg {
148 unsigned size;
149 const void *value;
150};
151
152/** The request input */
153struct fuse_in {
154 /** The request header */
155 struct fuse_in_header h;
156
157 /** True if the data for the last argument is in req->pages */
158 unsigned argpages:1;
159
160 /** Number of arguments */
161 unsigned numargs;
162
163 /** Array of arguments */
164 struct fuse_in_arg args[3];
165};
166
167/** One output argument of a request */
168struct fuse_arg {
169 unsigned size;
170 void *value;
171};
172
173/** The request output */
174struct fuse_out {
175 /** Header returned from userspace */
176 struct fuse_out_header h;
177
178 /*
179 * The following bitfields are not changed during the request
180 * processing
181 */
182
183 /** Last argument is variable length (can be shorter than
184 arg->size) */
185 unsigned argvar:1;
186
187 /** Last argument is a list of pages to copy data to */
188 unsigned argpages:1;
189
190 /** Zero partially or not copied pages */
191 unsigned page_zeroing:1;
192
193 /** Pages may be replaced with new ones */
194 unsigned page_replace:1;
195
196 /** Number or arguments */
197 unsigned numargs;
198
199 /** Array of arguments */
200 struct fuse_arg args[3];
201};
202
203/** The request state */
204enum fuse_req_state {
205 FUSE_REQ_INIT = 0,
206 FUSE_REQ_PENDING,
207 FUSE_REQ_READING,
208 FUSE_REQ_SENT,
209 FUSE_REQ_WRITING,
210 FUSE_REQ_FINISHED
211};
212
213/**
214 * A request to the client
215 */
216struct fuse_req {
217 /** This can be on either pending processing or io lists in
218 fuse_conn */
219 struct list_head list;
220
221 /** Entry on the interrupts list */
222 struct list_head intr_entry;
223
224 /** refcount */
225 atomic_t count;
226
227 /** Unique ID for the interrupt request */
228 u64 intr_unique;
229
230 /*
231 * The following bitfields are either set once before the
232 * request is queued or setting/clearing them is protected by
233 * fuse_conn->lock
234 */
235
236 /** True if the request has reply */
237 unsigned isreply:1;
238
239 /** Force sending of the request even if interrupted */
240 unsigned force:1;
241
242 /** The request was aborted */
243 unsigned aborted:1;
244
245 /** Request is sent in the background */
246 unsigned background:1;
247
248 /** The request has been interrupted */
249 unsigned interrupted:1;
250
251 /** Data is being copied to/from the request */
252 unsigned locked:1;
253
254 /** Request is counted as "waiting" */
255 unsigned waiting:1;
256
257 /** State of the request */
258 enum fuse_req_state state;
259
260 /** The request input */
261 struct fuse_in in;
262
263 /** The request output */
264 struct fuse_out out;
265
266 /** Used to wake up the task waiting for completion of request*/
267 wait_queue_head_t waitq;
268
269 /** Data for asynchronous requests */
270 union {
271 struct {
272 union {
273 struct fuse_release_in in;
274 struct work_struct work;
275 };
276 struct path path;
277 } release;
278 struct fuse_init_in init_in;
279 struct fuse_init_out init_out;
280 struct cuse_init_in cuse_init_in;
281 struct {
282 struct fuse_read_in in;
283 u64 attr_ver;
284 } read;
285 struct {
286 struct fuse_write_in in;
287 struct fuse_write_out out;
288 } write;
289 struct fuse_notify_retrieve_in retrieve_in;
290 struct fuse_lk_in lk_in;
291 } misc;
292
293 /** page vector */
294 struct page *pages[FUSE_MAX_PAGES_PER_REQ];
295
296 /** number of pages in vector */
297 unsigned num_pages;
298
299 /** offset of data on first page */
300 unsigned page_offset;
301
302 /** File used in the request (or NULL) */
303 struct fuse_file *ff;
304
305 /** Inode used in the request or NULL */
306 struct inode *inode;
307
308 /** Link on fi->writepages */
309 struct list_head writepages_entry;
310
311 /** Request completion callback */
312 void (*end)(struct fuse_conn *, struct fuse_req *);
313
314 /** Request is stolen from fuse_file->reserved_req */
315 struct file *stolen_file;
316};
317
318/**
319 * A Fuse connection.
320 *
321 * This structure is created, when the filesystem is mounted, and is
322 * destroyed, when the client device is closed and the filesystem is
323 * unmounted.
324 */
325struct fuse_conn {
326 /** Lock protecting accessess to members of this structure */
327 spinlock_t lock;
328
329 /** Mutex protecting against directory alias creation */
330 struct mutex inst_mutex;
331
332 /** Refcount */
333 atomic_t count;
334
335 /** The user id for this mount */
336 uid_t user_id;
337
338 /** The group id for this mount */
339 gid_t group_id;
340
341 /** The fuse mount flags for this mount */
342 unsigned flags;
343
344 /** Maximum read size */
345 unsigned max_read;
346
347 /** Maximum write size */
348 unsigned max_write;
349
350 /** Readers of the connection are waiting on this */
351 wait_queue_head_t waitq;
352
353 /** The list of pending requests */
354 struct list_head pending;
355
356 /** The list of requests being processed */
357 struct list_head processing;
358
359 /** The list of requests under I/O */
360 struct list_head io;
361
362 /** The next unique kernel file handle */
363 u64 khctr;
364
365 /** rbtree of fuse_files waiting for poll events indexed by ph */
366 struct rb_root polled_files;
367
368 /** Maximum number of outstanding background requests */
369 unsigned max_background;
370
371 /** Number of background requests at which congestion starts */
372 unsigned congestion_threshold;
373
374 /** Number of requests currently in the background */
375 unsigned num_background;
376
377 /** Number of background requests currently queued for userspace */
378 unsigned active_background;
379
380 /** The list of background requests set aside for later queuing */
381 struct list_head bg_queue;
382
383 /** Pending interrupts */
384 struct list_head interrupts;
385
386 /** Queue of pending forgets */
387 struct fuse_forget_link forget_list_head;
388 struct fuse_forget_link *forget_list_tail;
389
390 /** Batching of FORGET requests (positive indicates FORGET batch) */
391 int forget_batch;
392
393 /** Flag indicating if connection is blocked. This will be
394 the case before the INIT reply is received, and if there
395 are too many outstading backgrounds requests */
396 int blocked;
397
398 /** waitq for blocked connection */
399 wait_queue_head_t blocked_waitq;
400
401 /** waitq for reserved requests */
402 wait_queue_head_t reserved_req_waitq;
403
404 /** The next unique request id */
405 u64 reqctr;
406
407 /** Connection established, cleared on umount, connection
408 abort and device release */
409 unsigned connected;
410
411 /** Connection failed (version mismatch). Cannot race with
412 setting other bitfields since it is only set once in INIT
413 reply, before any other request, and never cleared */
414 unsigned conn_error:1;
415
416 /** Connection successful. Only set in INIT */
417 unsigned conn_init:1;
418
419 /** Do readpages asynchronously? Only set in INIT */
420 unsigned async_read:1;
421
422 /** Do not send separate SETATTR request before open(O_TRUNC) */
423 unsigned atomic_o_trunc:1;
424
425 /** Filesystem supports NFS exporting. Only set in INIT */
426 unsigned export_support:1;
427
428 /** Set if bdi is valid */
429 unsigned bdi_initialized:1;
430
431 /*
432 * The following bitfields are only for optimization purposes
433 * and hence races in setting them will not cause malfunction
434 */
435
436 /** Is fsync not implemented by fs? */
437 unsigned no_fsync:1;
438
439 /** Is fsyncdir not implemented by fs? */
440 unsigned no_fsyncdir:1;
441
442 /** Is flush not implemented by fs? */
443 unsigned no_flush:1;
444
445 /** Is setxattr not implemented by fs? */
446 unsigned no_setxattr:1;
447
448 /** Is getxattr not implemented by fs? */
449 unsigned no_getxattr:1;
450
451 /** Is listxattr not implemented by fs? */
452 unsigned no_listxattr:1;
453
454 /** Is removexattr not implemented by fs? */
455 unsigned no_removexattr:1;
456
457 /** Are posix file locking primitives not implemented by fs? */
458 unsigned no_lock:1;
459
460 /** Is access not implemented by fs? */
461 unsigned no_access:1;
462
463 /** Is create not implemented by fs? */
464 unsigned no_create:1;
465
466 /** Is interrupt not implemented by fs? */
467 unsigned no_interrupt:1;
468
469 /** Is bmap not implemented by fs? */
470 unsigned no_bmap:1;
471
472 /** Is poll not implemented by fs? */
473 unsigned no_poll:1;
474
475 /** Do multi-page cached writes */
476 unsigned big_writes:1;
477
478 /** Don't apply umask to creation modes */
479 unsigned dont_mask:1;
480
481 /** Are BSD file locking primitives not implemented by fs? */
482 unsigned no_flock:1;
483
484 /** Is fallocate not implemented by fs? */
485 unsigned no_fallocate:1;
486
487 /** The number of requests waiting for completion */
488 atomic_t num_waiting;
489
490 /** Negotiated minor version */
491 unsigned minor;
492
493 /** Backing dev info */
494 struct backing_dev_info bdi;
495
496 /** Entry on the fuse_conn_list */
497 struct list_head entry;
498
499 /** Device ID from super block */
500 dev_t dev;
501
502 /** Dentries in the control filesystem */
503 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
504
505 /** number of dentries used in the above array */
506 int ctl_ndents;
507
508 /** O_ASYNC requests */
509 struct fasync_struct *fasync;
510
511 /** Key for lock owner ID scrambling */
512 u32 scramble_key[4];
513
514 /** Reserved request for the DESTROY message */
515 struct fuse_req *destroy_req;
516
517 /** Version counter for attribute changes */
518 u64 attr_version;
519
520 /** Called on final put */
521 void (*release)(struct fuse_conn *);
522
523 /** Super block for this connection. */
524 struct super_block *sb;
525
526 /** Read/write semaphore to hold when accessing sb. */
527 struct rw_semaphore killsb;
528};
529
530static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
531{
532 return sb->s_fs_info;
533}
534
535static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
536{
537 return get_fuse_conn_super(inode->i_sb);
538}
539
540static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
541{
542 return container_of(inode, struct fuse_inode, inode);
543}
544
545static inline u64 get_node_id(struct inode *inode)
546{
547 return get_fuse_inode(inode)->nodeid;
548}
549
550/** Device operations */
551extern const struct file_operations fuse_dev_operations;
552
553extern const struct dentry_operations fuse_dentry_operations;
554
555/**
556 * Inode to nodeid comparison.
557 */
558int fuse_inode_eq(struct inode *inode, void *_nodeidp);
559
560/**
561 * Get a filled in inode
562 */
563struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
564 int generation, struct fuse_attr *attr,
565 u64 attr_valid, u64 attr_version);
566
567int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
568 struct fuse_entry_out *outarg, struct inode **inode);
569
570/**
571 * Send FORGET command
572 */
573void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
574 u64 nodeid, u64 nlookup);
575
576struct fuse_forget_link *fuse_alloc_forget(void);
577
578/**
579 * Initialize READ or READDIR request
580 */
581void fuse_read_fill(struct fuse_req *req, struct file *file,
582 loff_t pos, size_t count, int opcode);
583
584/**
585 * Send OPEN or OPENDIR request
586 */
587int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
588
589struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
590struct fuse_file *fuse_file_get(struct fuse_file *ff);
591void fuse_file_free(struct fuse_file *ff);
592void fuse_finish_open(struct inode *inode, struct file *file);
593
594void fuse_sync_release(struct fuse_file *ff, int flags);
595
596/**
597 * Send RELEASE or RELEASEDIR request
598 */
599void fuse_release_common(struct file *file, int opcode);
600
601/**
602 * Send FSYNC or FSYNCDIR request
603 */
604int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
605 int datasync, int isdir);
606
607/**
608 * Notify poll wakeup
609 */
610int fuse_notify_poll_wakeup(struct fuse_conn *fc,
611 struct fuse_notify_poll_wakeup_out *outarg);
612
613/**
614 * Initialize file operations on a regular file
615 */
616void fuse_init_file_inode(struct inode *inode);
617
618/**
619 * Initialize inode operations on regular files and special files
620 */
621void fuse_init_common(struct inode *inode);
622
623/**
624 * Initialize inode and file operations on a directory
625 */
626void fuse_init_dir(struct inode *inode);
627
628/**
629 * Initialize inode operations on a symlink
630 */
631void fuse_init_symlink(struct inode *inode);
632
633/**
634 * Change attributes of an inode
635 */
636void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
637 u64 attr_valid, u64 attr_version);
638
639void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
640 u64 attr_valid);
641
642/**
643 * Initialize the client device
644 */
645int fuse_dev_init(void);
646
647/**
648 * Cleanup the client device
649 */
650void fuse_dev_cleanup(void);
651
652int fuse_ctl_init(void);
653void fuse_ctl_cleanup(void);
654
655/**
656 * Allocate a request
657 */
658struct fuse_req *fuse_request_alloc(void);
659
660struct fuse_req *fuse_request_alloc_nofs(void);
661
662/**
663 * Free a request
664 */
665void fuse_request_free(struct fuse_req *req);
666
667/**
668 * Get a request, may fail with -ENOMEM
669 */
670struct fuse_req *fuse_get_req(struct fuse_conn *fc);
671
672/**
673 * Gets a requests for a file operation, always succeeds
674 */
675struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file);
676
677/**
678 * Decrement reference count of a request. If count goes to zero free
679 * the request.
680 */
681void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
682
683/**
684 * Send a request (synchronous)
685 */
686void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
687
688/**
689 * Send a request in the background
690 */
691void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
692
693void fuse_request_send_background_locked(struct fuse_conn *fc,
694 struct fuse_req *req);
695
696/* Abort all requests */
697void fuse_abort_conn(struct fuse_conn *fc);
698
699/**
700 * Invalidate inode attributes
701 */
702void fuse_invalidate_attr(struct inode *inode);
703
704void fuse_invalidate_entry_cache(struct dentry *entry);
705
706/**
707 * Acquire reference to fuse_conn
708 */
709struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
710
711void fuse_conn_kill(struct fuse_conn *fc);
712
713/**
714 * Initialize fuse_conn
715 */
716void fuse_conn_init(struct fuse_conn *fc);
717
718/**
719 * Release reference to fuse_conn
720 */
721void fuse_conn_put(struct fuse_conn *fc);
722
723/**
724 * Add connection to control filesystem
725 */
726int fuse_ctl_add_conn(struct fuse_conn *fc);
727
728/**
729 * Remove connection from control filesystem
730 */
731void fuse_ctl_remove_conn(struct fuse_conn *fc);
732
733/**
734 * Is file type valid?
735 */
736int fuse_valid_type(int m);
737
738/**
739 * Is task allowed to perform filesystem operation?
740 */
741int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task);
742
743u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
744
745int fuse_update_attributes(struct inode *inode, struct kstat *stat,
746 struct file *file, bool *refreshed);
747
748void fuse_flush_writepages(struct inode *inode);
749
750void fuse_set_nowrite(struct inode *inode);
751void fuse_release_nowrite(struct inode *inode);
752
753u64 fuse_get_attr_version(struct fuse_conn *fc);
754
755/**
756 * File-system tells the kernel to invalidate cache for the given node id.
757 */
758int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
759 loff_t offset, loff_t len);
760
761/**
762 * File-system tells the kernel to invalidate parent attributes and
763 * the dentry matching parent/name.
764 *
765 * If the child_nodeid is non-zero and:
766 * - matches the inode number for the dentry matching parent/name,
767 * - is not a mount point
768 * - is a file or oan empty directory
769 * then the dentry is unhashed (d_delete()).
770 */
771int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
772 u64 child_nodeid, struct qstr *name);
773
774int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
775 bool isdir);
776ssize_t fuse_direct_io(struct file *file, const char __user *buf,
777 size_t count, loff_t *ppos, int write);
778long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
779 unsigned int flags);
780long fuse_ioctl_common(struct file *file, unsigned int cmd,
781 unsigned long arg, unsigned int flags);
782unsigned fuse_file_poll(struct file *file, poll_table *wait);
783int fuse_dev_release(struct inode *inode, struct file *file);
784
785void fuse_write_update_size(struct inode *inode, loff_t pos);
786
787#endif /* _FS_FUSE_I_H */
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 */
51extern struct list_head fuse_conn_list;
52
53/** Global mutex protecting fuse_conn_list and the control filesystem */
54extern struct mutex fuse_mutex;
55
56/** Module parameters */
57extern unsigned max_user_bgreq;
58extern unsigned max_user_congthresh;
59
60/* One forget request */
61struct fuse_forget_link {
62 struct fuse_forget_one forget_one;
63 struct fuse_forget_link *next;
64};
65
66/** FUSE inode */
67struct 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 */
168enum {
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
179struct fuse_conn;
180struct fuse_mount;
181struct fuse_release_args;
182
183/** FUSE specific file data */
184struct fuse_file {
185 /** Fuse connection for this file */
186 struct fuse_mount *fm;
187
188 /* Argument space reserved for release */
189 struct fuse_release_args *release_args;
190
191 /** Kernel file handle guaranteed to be unique */
192 u64 kh;
193
194 /** File handle used by userspace */
195 u64 fh;
196
197 /** Node id of this file */
198 u64 nodeid;
199
200 /** Refcount */
201 refcount_t count;
202
203 /** FOPEN_* flags returned by open */
204 u32 open_flags;
205
206 /** Entry on inode's write_files list */
207 struct list_head write_entry;
208
209 /* Readdir related */
210 struct {
211 /*
212 * Protects below fields against (crazy) parallel readdir on
213 * same open file. Uncontended in the normal case.
214 */
215 struct mutex lock;
216
217 /* Dir stream position */
218 loff_t pos;
219
220 /* Offset in cache */
221 loff_t cache_off;
222
223 /* Version of cache we are reading */
224 u64 version;
225
226 } readdir;
227
228 /** RB node to be linked on fuse_conn->polled_files */
229 struct rb_node polled_node;
230
231 /** Wait queue head for poll */
232 wait_queue_head_t poll_wait;
233
234 /** Has flock been performed on this file? */
235 bool flock:1;
236};
237
238/** One input argument of a request */
239struct fuse_in_arg {
240 unsigned size;
241 const void *value;
242};
243
244/** One output argument of a request */
245struct fuse_arg {
246 unsigned size;
247 void *value;
248};
249
250/** FUSE page descriptor */
251struct fuse_page_desc {
252 unsigned int length;
253 unsigned int offset;
254};
255
256struct fuse_args {
257 uint64_t nodeid;
258 uint32_t opcode;
259 unsigned short in_numargs;
260 unsigned short out_numargs;
261 bool force:1;
262 bool noreply:1;
263 bool nocreds:1;
264 bool in_pages:1;
265 bool out_pages:1;
266 bool out_argvar:1;
267 bool page_zeroing:1;
268 bool page_replace:1;
269 bool may_block:1;
270 struct fuse_in_arg in_args[3];
271 struct fuse_arg out_args[2];
272 void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
273};
274
275struct fuse_args_pages {
276 struct fuse_args args;
277 struct page **pages;
278 struct fuse_page_desc *descs;
279 unsigned int num_pages;
280};
281
282#define FUSE_ARGS(args) struct fuse_args args = {}
283
284/** The request IO state (for asynchronous processing) */
285struct fuse_io_priv {
286 struct kref refcnt;
287 int async;
288 spinlock_t lock;
289 unsigned reqs;
290 ssize_t bytes;
291 size_t size;
292 __u64 offset;
293 bool write;
294 bool should_dirty;
295 int err;
296 struct kiocb *iocb;
297 struct completion *done;
298 bool blocking;
299};
300
301#define FUSE_IO_PRIV_SYNC(i) \
302{ \
303 .refcnt = KREF_INIT(1), \
304 .async = 0, \
305 .iocb = i, \
306}
307
308/**
309 * Request flags
310 *
311 * FR_ISREPLY: set if the request has reply
312 * FR_FORCE: force sending of the request even if interrupted
313 * FR_BACKGROUND: request is sent in the background
314 * FR_WAITING: request is counted as "waiting"
315 * FR_ABORTED: the request was aborted
316 * FR_INTERRUPTED: the request has been interrupted
317 * FR_LOCKED: data is being copied to/from the request
318 * FR_PENDING: request is not yet in userspace
319 * FR_SENT: request is in userspace, waiting for an answer
320 * FR_FINISHED: request is finished
321 * FR_PRIVATE: request is on private list
322 * FR_ASYNC: request is asynchronous
323 */
324enum fuse_req_flag {
325 FR_ISREPLY,
326 FR_FORCE,
327 FR_BACKGROUND,
328 FR_WAITING,
329 FR_ABORTED,
330 FR_INTERRUPTED,
331 FR_LOCKED,
332 FR_PENDING,
333 FR_SENT,
334 FR_FINISHED,
335 FR_PRIVATE,
336 FR_ASYNC,
337};
338
339/**
340 * A request to the client
341 *
342 * .waitq.lock protects the following fields:
343 * - FR_ABORTED
344 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
345 */
346struct fuse_req {
347 /** This can be on either pending processing or io lists in
348 fuse_conn */
349 struct list_head list;
350
351 /** Entry on the interrupts list */
352 struct list_head intr_entry;
353
354 /* Input/output arguments */
355 struct fuse_args *args;
356
357 /** refcount */
358 refcount_t count;
359
360 /* Request flags, updated with test/set/clear_bit() */
361 unsigned long flags;
362
363 /* The request input header */
364 struct {
365 struct fuse_in_header h;
366 } in;
367
368 /* The request output header */
369 struct {
370 struct fuse_out_header h;
371 } out;
372
373 /** Used to wake up the task waiting for completion of request*/
374 wait_queue_head_t waitq;
375
376#if IS_ENABLED(CONFIG_VIRTIO_FS)
377 /** virtio-fs's physically contiguous buffer for in and out args */
378 void *argbuf;
379#endif
380
381 /** fuse_mount this request belongs to */
382 struct fuse_mount *fm;
383};
384
385struct fuse_iqueue;
386
387/**
388 * Input queue callbacks
389 *
390 * Input queue signalling is device-specific. For example, the /dev/fuse file
391 * uses fiq->waitq and fasync to wake processes that are waiting on queue
392 * readiness. These callbacks allow other device types to respond to input
393 * queue activity.
394 */
395struct fuse_iqueue_ops {
396 /**
397 * Signal that a forget has been queued
398 */
399 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
400 __releases(fiq->lock);
401
402 /**
403 * Signal that an INTERRUPT request has been queued
404 */
405 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
406 __releases(fiq->lock);
407
408 /**
409 * Signal that a request has been queued
410 */
411 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
412 __releases(fiq->lock);
413
414 /**
415 * Clean up when fuse_iqueue is destroyed
416 */
417 void (*release)(struct fuse_iqueue *fiq);
418};
419
420/** /dev/fuse input queue operations */
421extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
422
423struct fuse_iqueue {
424 /** Connection established */
425 unsigned connected;
426
427 /** Lock protecting accesses to members of this structure */
428 spinlock_t lock;
429
430 /** Readers of the connection are waiting on this */
431 wait_queue_head_t waitq;
432
433 /** The next unique request id */
434 u64 reqctr;
435
436 /** The list of pending requests */
437 struct list_head pending;
438
439 /** Pending interrupts */
440 struct list_head interrupts;
441
442 /** Queue of pending forgets */
443 struct fuse_forget_link forget_list_head;
444 struct fuse_forget_link *forget_list_tail;
445
446 /** Batching of FORGET requests (positive indicates FORGET batch) */
447 int forget_batch;
448
449 /** O_ASYNC requests */
450 struct fasync_struct *fasync;
451
452 /** Device-specific callbacks */
453 const struct fuse_iqueue_ops *ops;
454
455 /** Device-specific state */
456 void *priv;
457};
458
459#define FUSE_PQ_HASH_BITS 8
460#define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
461
462struct fuse_pqueue {
463 /** Connection established */
464 unsigned connected;
465
466 /** Lock protecting accessess to members of this structure */
467 spinlock_t lock;
468
469 /** Hash table of requests being processed */
470 struct list_head *processing;
471
472 /** The list of requests under I/O */
473 struct list_head io;
474};
475
476/**
477 * Fuse device instance
478 */
479struct fuse_dev {
480 /** Fuse connection for this device */
481 struct fuse_conn *fc;
482
483 /** Processing queue */
484 struct fuse_pqueue pq;
485
486 /** list entry on fc->devices */
487 struct list_head entry;
488};
489
490struct fuse_fs_context {
491 int fd;
492 unsigned int rootmode;
493 kuid_t user_id;
494 kgid_t group_id;
495 bool is_bdev:1;
496 bool fd_present:1;
497 bool rootmode_present:1;
498 bool user_id_present:1;
499 bool group_id_present:1;
500 bool default_permissions:1;
501 bool allow_other:1;
502 bool destroy:1;
503 bool no_control:1;
504 bool no_force_umount:1;
505 bool legacy_opts_show:1;
506 bool dax:1;
507 unsigned int max_read;
508 unsigned int blksize;
509 const char *subtype;
510
511 /* DAX device, may be NULL */
512 struct dax_device *dax_dev;
513
514 /* fuse_dev pointer to fill in, should contain NULL on entry */
515 void **fudptr;
516};
517
518struct fuse_sync_bucket {
519 /* count is a possible scalability bottleneck */
520 atomic_t count;
521 wait_queue_head_t waitq;
522 struct rcu_head rcu;
523};
524
525/**
526 * A Fuse connection.
527 *
528 * This structure is created, when the root filesystem is mounted, and
529 * is destroyed, when the client device is closed and the last
530 * fuse_mount is destroyed.
531 */
532struct fuse_conn {
533 /** Lock protecting accessess to members of this structure */
534 spinlock_t lock;
535
536 /** Refcount */
537 refcount_t count;
538
539 /** Number of fuse_dev's */
540 atomic_t dev_count;
541
542 struct rcu_head rcu;
543
544 /** The user id for this mount */
545 kuid_t user_id;
546
547 /** The group id for this mount */
548 kgid_t group_id;
549
550 /** The pid namespace for this mount */
551 struct pid_namespace *pid_ns;
552
553 /** The user namespace for this mount */
554 struct user_namespace *user_ns;
555
556 /** Maximum read size */
557 unsigned max_read;
558
559 /** Maximum write size */
560 unsigned max_write;
561
562 /** Maximum number of pages that can be used in a single request */
563 unsigned int max_pages;
564
565 /** Constrain ->max_pages to this value during feature negotiation */
566 unsigned int max_pages_limit;
567
568 /** Input queue */
569 struct fuse_iqueue iq;
570
571 /** The next unique kernel file handle */
572 atomic64_t khctr;
573
574 /** rbtree of fuse_files waiting for poll events indexed by ph */
575 struct rb_root polled_files;
576
577 /** Maximum number of outstanding background requests */
578 unsigned max_background;
579
580 /** Number of background requests at which congestion starts */
581 unsigned congestion_threshold;
582
583 /** Number of requests currently in the background */
584 unsigned num_background;
585
586 /** Number of background requests currently queued for userspace */
587 unsigned active_background;
588
589 /** The list of background requests set aside for later queuing */
590 struct list_head bg_queue;
591
592 /** Protects: max_background, congestion_threshold, num_background,
593 * active_background, bg_queue, blocked */
594 spinlock_t bg_lock;
595
596 /** Flag indicating that INIT reply has been received. Allocating
597 * any fuse request will be suspended until the flag is set */
598 int initialized;
599
600 /** Flag indicating if connection is blocked. This will be
601 the case before the INIT reply is received, and if there
602 are too many outstading backgrounds requests */
603 int blocked;
604
605 /** waitq for blocked connection */
606 wait_queue_head_t blocked_waitq;
607
608 /** Connection established, cleared on umount, connection
609 abort and device release */
610 unsigned connected;
611
612 /** Connection aborted via sysfs */
613 bool aborted;
614
615 /** Connection failed (version mismatch). Cannot race with
616 setting other bitfields since it is only set once in INIT
617 reply, before any other request, and never cleared */
618 unsigned conn_error:1;
619
620 /** Connection successful. Only set in INIT */
621 unsigned conn_init:1;
622
623 /** Do readpages asynchronously? Only set in INIT */
624 unsigned async_read:1;
625
626 /** Return an unique read error after abort. Only set in INIT */
627 unsigned abort_err:1;
628
629 /** Do not send separate SETATTR request before open(O_TRUNC) */
630 unsigned atomic_o_trunc:1;
631
632 /** Filesystem supports NFS exporting. Only set in INIT */
633 unsigned export_support:1;
634
635 /** write-back cache policy (default is write-through) */
636 unsigned writeback_cache:1;
637
638 /** allow parallel lookups and readdir (default is serialized) */
639 unsigned parallel_dirops:1;
640
641 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
642 unsigned handle_killpriv:1;
643
644 /** cache READLINK responses in page cache */
645 unsigned cache_symlinks:1;
646
647 /* show legacy mount options */
648 unsigned int legacy_opts_show:1;
649
650 /*
651 * fs kills suid/sgid/cap on write/chown/trunc. suid is killed on
652 * write/trunc only if caller did not have CAP_FSETID. sgid is killed
653 * on write/truncate only if caller did not have CAP_FSETID as well as
654 * file has group execute permission.
655 */
656 unsigned handle_killpriv_v2:1;
657
658 /*
659 * The following bitfields are only for optimization purposes
660 * and hence races in setting them will not cause malfunction
661 */
662
663 /** Is open/release not implemented by fs? */
664 unsigned no_open:1;
665
666 /** Is opendir/releasedir not implemented by fs? */
667 unsigned no_opendir:1;
668
669 /** Is fsync not implemented by fs? */
670 unsigned no_fsync:1;
671
672 /** Is fsyncdir not implemented by fs? */
673 unsigned no_fsyncdir:1;
674
675 /** Is flush not implemented by fs? */
676 unsigned no_flush:1;
677
678 /** Is setxattr not implemented by fs? */
679 unsigned no_setxattr:1;
680
681 /** Does file server support extended setxattr */
682 unsigned setxattr_ext:1;
683
684 /** Is getxattr not implemented by fs? */
685 unsigned no_getxattr:1;
686
687 /** Is listxattr not implemented by fs? */
688 unsigned no_listxattr:1;
689
690 /** Is removexattr not implemented by fs? */
691 unsigned no_removexattr:1;
692
693 /** Are posix file locking primitives not implemented by fs? */
694 unsigned no_lock:1;
695
696 /** Is access not implemented by fs? */
697 unsigned no_access:1;
698
699 /** Is create not implemented by fs? */
700 unsigned no_create:1;
701
702 /** Is interrupt not implemented by fs? */
703 unsigned no_interrupt:1;
704
705 /** Is bmap not implemented by fs? */
706 unsigned no_bmap:1;
707
708 /** Is poll not implemented by fs? */
709 unsigned no_poll:1;
710
711 /** Do multi-page cached writes */
712 unsigned big_writes:1;
713
714 /** Don't apply umask to creation modes */
715 unsigned dont_mask:1;
716
717 /** Are BSD file locking primitives not implemented by fs? */
718 unsigned no_flock:1;
719
720 /** Is fallocate not implemented by fs? */
721 unsigned no_fallocate:1;
722
723 /** Is rename with flags implemented by fs? */
724 unsigned no_rename2:1;
725
726 /** Use enhanced/automatic page cache invalidation. */
727 unsigned auto_inval_data:1;
728
729 /** Filesystem is fully responsible for page cache invalidation. */
730 unsigned explicit_inval_data:1;
731
732 /** Does the filesystem support readdirplus? */
733 unsigned do_readdirplus:1;
734
735 /** Does the filesystem want adaptive readdirplus? */
736 unsigned readdirplus_auto:1;
737
738 /** Does the filesystem support asynchronous direct-IO submission? */
739 unsigned async_dio:1;
740
741 /** Is lseek not implemented by fs? */
742 unsigned no_lseek:1;
743
744 /** Does the filesystem support posix acls? */
745 unsigned posix_acl:1;
746
747 /** Check permissions based on the file mode or not? */
748 unsigned default_permissions:1;
749
750 /** Allow other than the mounter user to access the filesystem ? */
751 unsigned allow_other:1;
752
753 /** Does the filesystem support copy_file_range? */
754 unsigned no_copy_file_range:1;
755
756 /* Send DESTROY request */
757 unsigned int destroy:1;
758
759 /* Delete dentries that have gone stale */
760 unsigned int delete_stale:1;
761
762 /** Do not create entry in fusectl fs */
763 unsigned int no_control:1;
764
765 /** Do not allow MNT_FORCE umount */
766 unsigned int no_force_umount:1;
767
768 /* Auto-mount submounts announced by the server */
769 unsigned int auto_submounts:1;
770
771 /* Propagate syncfs() to server */
772 unsigned int sync_fs:1;
773
774 /** The number of requests waiting for completion */
775 atomic_t num_waiting;
776
777 /** Negotiated minor version */
778 unsigned minor;
779
780 /** Entry on the fuse_mount_list */
781 struct list_head entry;
782
783 /** Device ID from the root super block */
784 dev_t dev;
785
786 /** Dentries in the control filesystem */
787 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
788
789 /** number of dentries used in the above array */
790 int ctl_ndents;
791
792 /** Key for lock owner ID scrambling */
793 u32 scramble_key[4];
794
795 /** Version counter for attribute changes */
796 atomic64_t attr_version;
797
798 /** Called on final put */
799 void (*release)(struct fuse_conn *);
800
801 /**
802 * Read/write semaphore to hold when accessing the sb of any
803 * fuse_mount belonging to this connection
804 */
805 struct rw_semaphore killsb;
806
807 /** List of device instances belonging to this connection */
808 struct list_head devices;
809
810#ifdef CONFIG_FUSE_DAX
811 /* Dax specific conn data, non-NULL if DAX is enabled */
812 struct fuse_conn_dax *dax;
813#endif
814
815 /** List of filesystems using this connection */
816 struct list_head mounts;
817
818 /* New writepages go into this bucket */
819 struct fuse_sync_bucket __rcu *curr_bucket;
820};
821
822/*
823 * Represents a mounted filesystem, potentially a submount.
824 *
825 * This object allows sharing a fuse_conn between separate mounts to
826 * allow submounts with dedicated superblocks and thus separate device
827 * IDs.
828 */
829struct fuse_mount {
830 /* Underlying (potentially shared) connection to the FUSE server */
831 struct fuse_conn *fc;
832
833 /*
834 * Super block for this connection (fc->killsb must be held when
835 * accessing this).
836 */
837 struct super_block *sb;
838
839 /* Entry on fc->mounts */
840 struct list_head fc_entry;
841};
842
843static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
844{
845 return sb->s_fs_info;
846}
847
848static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
849{
850 return get_fuse_mount_super(sb)->fc;
851}
852
853static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
854{
855 return get_fuse_mount_super(inode->i_sb);
856}
857
858static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
859{
860 return get_fuse_mount_super(inode->i_sb)->fc;
861}
862
863static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
864{
865 return container_of(inode, struct fuse_inode, inode);
866}
867
868static inline u64 get_node_id(struct inode *inode)
869{
870 return get_fuse_inode(inode)->nodeid;
871}
872
873static inline int invalid_nodeid(u64 nodeid)
874{
875 return !nodeid || nodeid == FUSE_ROOT_ID;
876}
877
878static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
879{
880 return atomic64_read(&fc->attr_version);
881}
882
883static inline bool fuse_stale_inode(const struct inode *inode, int generation,
884 struct fuse_attr *attr)
885{
886 return inode->i_generation != generation ||
887 inode_wrong_type(inode, attr->mode);
888}
889
890static inline void fuse_make_bad(struct inode *inode)
891{
892 remove_inode_hash(inode);
893 set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
894}
895
896static inline bool fuse_is_bad(struct inode *inode)
897{
898 return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
899}
900
901static inline struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,
902 struct fuse_page_desc **desc)
903{
904 struct page **pages;
905
906 pages = kzalloc(npages * (sizeof(struct page *) +
907 sizeof(struct fuse_page_desc)), flags);
908 *desc = (void *) (pages + npages);
909
910 return pages;
911}
912
913static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,
914 unsigned int index,
915 unsigned int nr_pages)
916{
917 int i;
918
919 for (i = index; i < index + nr_pages; i++)
920 descs[i].length = PAGE_SIZE - descs[i].offset;
921}
922
923static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket)
924{
925 /* Need RCU protection to prevent use after free after the decrement */
926 rcu_read_lock();
927 if (atomic_dec_and_test(&bucket->count))
928 wake_up(&bucket->waitq);
929 rcu_read_unlock();
930}
931
932/** Device operations */
933extern const struct file_operations fuse_dev_operations;
934
935extern const struct dentry_operations fuse_dentry_operations;
936extern const struct dentry_operations fuse_root_dentry_operations;
937
938/**
939 * Get a filled in inode
940 */
941struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
942 int generation, struct fuse_attr *attr,
943 u64 attr_valid, u64 attr_version);
944
945int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
946 struct fuse_entry_out *outarg, struct inode **inode);
947
948/**
949 * Send FORGET command
950 */
951void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
952 u64 nodeid, u64 nlookup);
953
954struct fuse_forget_link *fuse_alloc_forget(void);
955
956struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
957 unsigned int max,
958 unsigned int *countp);
959
960/*
961 * Initialize READ or READDIR request
962 */
963struct fuse_io_args {
964 union {
965 struct {
966 struct fuse_read_in in;
967 u64 attr_ver;
968 } read;
969 struct {
970 struct fuse_write_in in;
971 struct fuse_write_out out;
972 bool page_locked;
973 } write;
974 };
975 struct fuse_args_pages ap;
976 struct fuse_io_priv *io;
977 struct fuse_file *ff;
978};
979
980void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
981 size_t count, int opcode);
982
983
984/**
985 * Send OPEN or OPENDIR request
986 */
987int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
988
989struct fuse_file *fuse_file_alloc(struct fuse_mount *fm);
990void fuse_file_free(struct fuse_file *ff);
991void fuse_finish_open(struct inode *inode, struct file *file);
992
993void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
994 unsigned int flags);
995
996/**
997 * Send RELEASE or RELEASEDIR request
998 */
999void fuse_release_common(struct file *file, bool isdir);
1000
1001/**
1002 * Send FSYNC or FSYNCDIR request
1003 */
1004int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
1005 int datasync, int opcode);
1006
1007/**
1008 * Notify poll wakeup
1009 */
1010int fuse_notify_poll_wakeup(struct fuse_conn *fc,
1011 struct fuse_notify_poll_wakeup_out *outarg);
1012
1013/**
1014 * Initialize file operations on a regular file
1015 */
1016void fuse_init_file_inode(struct inode *inode);
1017
1018/**
1019 * Initialize inode operations on regular files and special files
1020 */
1021void fuse_init_common(struct inode *inode);
1022
1023/**
1024 * Initialize inode and file operations on a directory
1025 */
1026void fuse_init_dir(struct inode *inode);
1027
1028/**
1029 * Initialize inode operations on a symlink
1030 */
1031void fuse_init_symlink(struct inode *inode);
1032
1033/**
1034 * Change attributes of an inode
1035 */
1036void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
1037 u64 attr_valid, u64 attr_version);
1038
1039void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
1040 u64 attr_valid);
1041
1042/**
1043 * Initialize the client device
1044 */
1045int fuse_dev_init(void);
1046
1047/**
1048 * Cleanup the client device
1049 */
1050void fuse_dev_cleanup(void);
1051
1052int fuse_ctl_init(void);
1053void __exit fuse_ctl_cleanup(void);
1054
1055/**
1056 * Simple request sending that does request allocation and freeing
1057 */
1058ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args);
1059int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
1060 gfp_t gfp_flags);
1061
1062/**
1063 * End a finished request
1064 */
1065void fuse_request_end(struct fuse_req *req);
1066
1067/* Abort all requests */
1068void fuse_abort_conn(struct fuse_conn *fc);
1069void fuse_wait_aborted(struct fuse_conn *fc);
1070
1071/**
1072 * Invalidate inode attributes
1073 */
1074void fuse_invalidate_attr(struct inode *inode);
1075
1076void fuse_invalidate_entry_cache(struct dentry *entry);
1077
1078void fuse_invalidate_atime(struct inode *inode);
1079
1080u64 entry_attr_timeout(struct fuse_entry_out *o);
1081void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
1082
1083/**
1084 * Acquire reference to fuse_conn
1085 */
1086struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
1087
1088/**
1089 * Initialize fuse_conn
1090 */
1091void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
1092 struct user_namespace *user_ns,
1093 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
1094
1095/**
1096 * Release reference to fuse_conn
1097 */
1098void fuse_conn_put(struct fuse_conn *fc);
1099
1100struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
1101struct fuse_dev *fuse_dev_alloc(void);
1102void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
1103void fuse_dev_free(struct fuse_dev *fud);
1104void fuse_send_init(struct fuse_mount *fm);
1105
1106/**
1107 * Fill in superblock and initialize fuse connection
1108 * @sb: partially-initialized superblock to fill in
1109 * @ctx: mount context
1110 */
1111int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
1112
1113/*
1114 * Remove the mount from the connection
1115 *
1116 * Returns whether this was the last mount
1117 */
1118bool fuse_mount_remove(struct fuse_mount *fm);
1119
1120/*
1121 * Setup context ops for submounts
1122 */
1123int fuse_init_fs_context_submount(struct fs_context *fsc);
1124
1125/*
1126 * Shut down the connection (possibly sending DESTROY request).
1127 */
1128void fuse_conn_destroy(struct fuse_mount *fm);
1129
1130/**
1131 * Add connection to control filesystem
1132 */
1133int fuse_ctl_add_conn(struct fuse_conn *fc);
1134
1135/**
1136 * Remove connection from control filesystem
1137 */
1138void fuse_ctl_remove_conn(struct fuse_conn *fc);
1139
1140/**
1141 * Is file type valid?
1142 */
1143int fuse_valid_type(int m);
1144
1145bool fuse_invalid_attr(struct fuse_attr *attr);
1146
1147/**
1148 * Is current process allowed to perform filesystem operation?
1149 */
1150int fuse_allow_current_process(struct fuse_conn *fc);
1151
1152u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1153
1154void fuse_update_ctime(struct inode *inode);
1155
1156int fuse_update_attributes(struct inode *inode, struct file *file);
1157
1158void fuse_flush_writepages(struct inode *inode);
1159
1160void fuse_set_nowrite(struct inode *inode);
1161void fuse_release_nowrite(struct inode *inode);
1162
1163/**
1164 * Scan all fuse_mounts belonging to fc to find the first where
1165 * ilookup5() returns a result. Return that result and the
1166 * respective fuse_mount in *fm (unless fm is NULL).
1167 *
1168 * The caller must hold fc->killsb.
1169 */
1170struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
1171 struct fuse_mount **fm);
1172
1173/**
1174 * File-system tells the kernel to invalidate cache for the given node id.
1175 */
1176int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
1177 loff_t offset, loff_t len);
1178
1179/**
1180 * File-system tells the kernel to invalidate parent attributes and
1181 * the dentry matching parent/name.
1182 *
1183 * If the child_nodeid is non-zero and:
1184 * - matches the inode number for the dentry matching parent/name,
1185 * - is not a mount point
1186 * - is a file or oan empty directory
1187 * then the dentry is unhashed (d_delete()).
1188 */
1189int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
1190 u64 child_nodeid, struct qstr *name);
1191
1192int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
1193 bool isdir);
1194
1195/**
1196 * fuse_direct_io() flags
1197 */
1198
1199/** If set, it is WRITE; otherwise - READ */
1200#define FUSE_DIO_WRITE (1 << 0)
1201
1202/** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1203#define FUSE_DIO_CUSE (1 << 1)
1204
1205ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1206 loff_t *ppos, int flags);
1207long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1208 unsigned int flags);
1209long fuse_ioctl_common(struct file *file, unsigned int cmd,
1210 unsigned long arg, unsigned int flags);
1211__poll_t fuse_file_poll(struct file *file, poll_table *wait);
1212int fuse_dev_release(struct inode *inode, struct file *file);
1213
1214bool fuse_write_update_size(struct inode *inode, loff_t pos);
1215
1216int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1217int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1218
1219int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1220 struct file *file);
1221
1222void fuse_set_initialized(struct fuse_conn *fc);
1223
1224void fuse_unlock_inode(struct inode *inode, bool locked);
1225bool fuse_lock_inode(struct inode *inode);
1226
1227int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1228 size_t size, int flags, unsigned int extra_flags);
1229ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1230 size_t size);
1231ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1232int fuse_removexattr(struct inode *inode, const char *name);
1233extern const struct xattr_handler *fuse_xattr_handlers[];
1234extern const struct xattr_handler *fuse_acl_xattr_handlers[];
1235extern const struct xattr_handler *fuse_no_acl_xattr_handlers[];
1236
1237struct posix_acl;
1238struct posix_acl *fuse_get_acl(struct inode *inode, int type);
1239int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
1240 struct posix_acl *acl, int type);
1241
1242/* readdir.c */
1243int fuse_readdir(struct file *file, struct dir_context *ctx);
1244
1245/**
1246 * Return the number of bytes in an arguments list
1247 */
1248unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1249
1250/**
1251 * Get the next unique ID for a request
1252 */
1253u64 fuse_get_unique(struct fuse_iqueue *fiq);
1254void fuse_free_conn(struct fuse_conn *fc);
1255
1256/* dax.c */
1257
1258#define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
1259
1260ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
1261ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
1262int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
1263int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
1264int fuse_dax_conn_alloc(struct fuse_conn *fc, struct dax_device *dax_dev);
1265void fuse_dax_conn_free(struct fuse_conn *fc);
1266bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
1267void fuse_dax_inode_init(struct inode *inode);
1268void fuse_dax_inode_cleanup(struct inode *inode);
1269bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
1270void fuse_dax_cancel_work(struct fuse_conn *fc);
1271
1272/* ioctl.c */
1273long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1274long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
1275 unsigned long arg);
1276int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa);
1277int fuse_fileattr_set(struct user_namespace *mnt_userns,
1278 struct dentry *dentry, struct fileattr *fa);
1279
1280/* file.c */
1281
1282struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
1283 unsigned int open_flags, bool isdir);
1284void fuse_file_release(struct inode *inode, struct fuse_file *ff,
1285 unsigned int open_flags, fl_owner_t id, bool isdir);
1286
1287#endif /* _FS_FUSE_I_H */