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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 mode_t orig_i_mode;
84
85 /** Version of last attribute change */
86 u64 attr_version;
87
88 /** Files usable in writepage. Protected by fc->lock */
89 struct list_head write_files;
90
91 /** Writepages pending on truncate or fsync */
92 struct list_head queued_writes;
93
94 /** Number of sent writes, a negative bias (FUSE_NOWRITE)
95 * means more writes are blocked */
96 int writectr;
97
98 /** Waitq for writepage completion */
99 wait_queue_head_t page_waitq;
100
101 /** List of writepage requestst (pending or sent) */
102 struct list_head writepages;
103};
104
105struct fuse_conn;
106
107/** FUSE specific file data */
108struct fuse_file {
109 /** Fuse connection for this file */
110 struct fuse_conn *fc;
111
112 /** Request reserved for flush and release */
113 struct fuse_req *reserved_req;
114
115 /** Kernel file handle guaranteed to be unique */
116 u64 kh;
117
118 /** File handle used by userspace */
119 u64 fh;
120
121 /** Node id of this file */
122 u64 nodeid;
123
124 /** Refcount */
125 atomic_t count;
126
127 /** FOPEN_* flags returned by open */
128 u32 open_flags;
129
130 /** Entry on inode's write_files list */
131 struct list_head write_entry;
132
133 /** RB node to be linked on fuse_conn->polled_files */
134 struct rb_node polled_node;
135
136 /** Wait queue head for poll */
137 wait_queue_head_t poll_wait;
138
139 /** Has flock been performed on this file? */
140 bool flock:1;
141};
142
143/** One input argument of a request */
144struct fuse_in_arg {
145 unsigned size;
146 const void *value;
147};
148
149/** The request input */
150struct fuse_in {
151 /** The request header */
152 struct fuse_in_header h;
153
154 /** True if the data for the last argument is in req->pages */
155 unsigned argpages:1;
156
157 /** Number of arguments */
158 unsigned numargs;
159
160 /** Array of arguments */
161 struct fuse_in_arg args[3];
162};
163
164/** One output argument of a request */
165struct fuse_arg {
166 unsigned size;
167 void *value;
168};
169
170/** The request output */
171struct fuse_out {
172 /** Header returned from userspace */
173 struct fuse_out_header h;
174
175 /*
176 * The following bitfields are not changed during the request
177 * processing
178 */
179
180 /** Last argument is variable length (can be shorter than
181 arg->size) */
182 unsigned argvar:1;
183
184 /** Last argument is a list of pages to copy data to */
185 unsigned argpages:1;
186
187 /** Zero partially or not copied pages */
188 unsigned page_zeroing:1;
189
190 /** Pages may be replaced with new ones */
191 unsigned page_replace:1;
192
193 /** Number or arguments */
194 unsigned numargs;
195
196 /** Array of arguments */
197 struct fuse_arg args[3];
198};
199
200/** The request state */
201enum fuse_req_state {
202 FUSE_REQ_INIT = 0,
203 FUSE_REQ_PENDING,
204 FUSE_REQ_READING,
205 FUSE_REQ_SENT,
206 FUSE_REQ_WRITING,
207 FUSE_REQ_FINISHED
208};
209
210/**
211 * A request to the client
212 */
213struct fuse_req {
214 /** This can be on either pending processing or io lists in
215 fuse_conn */
216 struct list_head list;
217
218 /** Entry on the interrupts list */
219 struct list_head intr_entry;
220
221 /** refcount */
222 atomic_t count;
223
224 /** Unique ID for the interrupt request */
225 u64 intr_unique;
226
227 /*
228 * The following bitfields are either set once before the
229 * request is queued or setting/clearing them is protected by
230 * fuse_conn->lock
231 */
232
233 /** True if the request has reply */
234 unsigned isreply:1;
235
236 /** Force sending of the request even if interrupted */
237 unsigned force:1;
238
239 /** The request was aborted */
240 unsigned aborted:1;
241
242 /** Request is sent in the background */
243 unsigned background:1;
244
245 /** The request has been interrupted */
246 unsigned interrupted:1;
247
248 /** Data is being copied to/from the request */
249 unsigned locked:1;
250
251 /** Request is counted as "waiting" */
252 unsigned waiting:1;
253
254 /** State of the request */
255 enum fuse_req_state state;
256
257 /** The request input */
258 struct fuse_in in;
259
260 /** The request output */
261 struct fuse_out out;
262
263 /** Used to wake up the task waiting for completion of request*/
264 wait_queue_head_t waitq;
265
266 /** Data for asynchronous requests */
267 union {
268 struct {
269 union {
270 struct fuse_release_in in;
271 struct work_struct work;
272 };
273 struct path path;
274 } release;
275 struct fuse_init_in init_in;
276 struct fuse_init_out init_out;
277 struct cuse_init_in cuse_init_in;
278 struct {
279 struct fuse_read_in in;
280 u64 attr_ver;
281 } read;
282 struct {
283 struct fuse_write_in in;
284 struct fuse_write_out out;
285 } write;
286 struct fuse_notify_retrieve_in retrieve_in;
287 struct fuse_lk_in lk_in;
288 } misc;
289
290 /** page vector */
291 struct page *pages[FUSE_MAX_PAGES_PER_REQ];
292
293 /** number of pages in vector */
294 unsigned num_pages;
295
296 /** offset of data on first page */
297 unsigned page_offset;
298
299 /** File used in the request (or NULL) */
300 struct fuse_file *ff;
301
302 /** Inode used in the request or NULL */
303 struct inode *inode;
304
305 /** Link on fi->writepages */
306 struct list_head writepages_entry;
307
308 /** Request completion callback */
309 void (*end)(struct fuse_conn *, struct fuse_req *);
310
311 /** Request is stolen from fuse_file->reserved_req */
312 struct file *stolen_file;
313};
314
315/**
316 * A Fuse connection.
317 *
318 * This structure is created, when the filesystem is mounted, and is
319 * destroyed, when the client device is closed and the filesystem is
320 * unmounted.
321 */
322struct fuse_conn {
323 /** Lock protecting accessess to members of this structure */
324 spinlock_t lock;
325
326 /** Mutex protecting against directory alias creation */
327 struct mutex inst_mutex;
328
329 /** Refcount */
330 atomic_t count;
331
332 /** The user id for this mount */
333 uid_t user_id;
334
335 /** The group id for this mount */
336 gid_t group_id;
337
338 /** The fuse mount flags for this mount */
339 unsigned flags;
340
341 /** Maximum read size */
342 unsigned max_read;
343
344 /** Maximum write size */
345 unsigned max_write;
346
347 /** Readers of the connection are waiting on this */
348 wait_queue_head_t waitq;
349
350 /** The list of pending requests */
351 struct list_head pending;
352
353 /** The list of requests being processed */
354 struct list_head processing;
355
356 /** The list of requests under I/O */
357 struct list_head io;
358
359 /** The next unique kernel file handle */
360 u64 khctr;
361
362 /** rbtree of fuse_files waiting for poll events indexed by ph */
363 struct rb_root polled_files;
364
365 /** Maximum number of outstanding background requests */
366 unsigned max_background;
367
368 /** Number of background requests at which congestion starts */
369 unsigned congestion_threshold;
370
371 /** Number of requests currently in the background */
372 unsigned num_background;
373
374 /** Number of background requests currently queued for userspace */
375 unsigned active_background;
376
377 /** The list of background requests set aside for later queuing */
378 struct list_head bg_queue;
379
380 /** Pending interrupts */
381 struct list_head interrupts;
382
383 /** Queue of pending forgets */
384 struct fuse_forget_link forget_list_head;
385 struct fuse_forget_link *forget_list_tail;
386
387 /** Batching of FORGET requests (positive indicates FORGET batch) */
388 int forget_batch;
389
390 /** Flag indicating if connection is blocked. This will be
391 the case before the INIT reply is received, and if there
392 are too many outstading backgrounds requests */
393 int blocked;
394
395 /** waitq for blocked connection */
396 wait_queue_head_t blocked_waitq;
397
398 /** waitq for reserved requests */
399 wait_queue_head_t reserved_req_waitq;
400
401 /** The next unique request id */
402 u64 reqctr;
403
404 /** Connection established, cleared on umount, connection
405 abort and device release */
406 unsigned connected;
407
408 /** Connection failed (version mismatch). Cannot race with
409 setting other bitfields since it is only set once in INIT
410 reply, before any other request, and never cleared */
411 unsigned conn_error:1;
412
413 /** Connection successful. Only set in INIT */
414 unsigned conn_init:1;
415
416 /** Do readpages asynchronously? Only set in INIT */
417 unsigned async_read:1;
418
419 /** Do not send separate SETATTR request before open(O_TRUNC) */
420 unsigned atomic_o_trunc:1;
421
422 /** Filesystem supports NFS exporting. Only set in INIT */
423 unsigned export_support:1;
424
425 /** Set if bdi is valid */
426 unsigned bdi_initialized:1;
427
428 /*
429 * The following bitfields are only for optimization purposes
430 * and hence races in setting them will not cause malfunction
431 */
432
433 /** Is fsync not implemented by fs? */
434 unsigned no_fsync:1;
435
436 /** Is fsyncdir not implemented by fs? */
437 unsigned no_fsyncdir:1;
438
439 /** Is flush not implemented by fs? */
440 unsigned no_flush:1;
441
442 /** Is setxattr not implemented by fs? */
443 unsigned no_setxattr:1;
444
445 /** Is getxattr not implemented by fs? */
446 unsigned no_getxattr:1;
447
448 /** Is listxattr not implemented by fs? */
449 unsigned no_listxattr:1;
450
451 /** Is removexattr not implemented by fs? */
452 unsigned no_removexattr:1;
453
454 /** Are posix file locking primitives not implemented by fs? */
455 unsigned no_lock:1;
456
457 /** Is access not implemented by fs? */
458 unsigned no_access:1;
459
460 /** Is create not implemented by fs? */
461 unsigned no_create:1;
462
463 /** Is interrupt not implemented by fs? */
464 unsigned no_interrupt:1;
465
466 /** Is bmap not implemented by fs? */
467 unsigned no_bmap:1;
468
469 /** Is poll not implemented by fs? */
470 unsigned no_poll:1;
471
472 /** Do multi-page cached writes */
473 unsigned big_writes:1;
474
475 /** Don't apply umask to creation modes */
476 unsigned dont_mask:1;
477
478 /** Are BSD file locking primitives not implemented by fs? */
479 unsigned no_flock:1;
480
481 /** The number of requests waiting for completion */
482 atomic_t num_waiting;
483
484 /** Negotiated minor version */
485 unsigned minor;
486
487 /** Backing dev info */
488 struct backing_dev_info bdi;
489
490 /** Entry on the fuse_conn_list */
491 struct list_head entry;
492
493 /** Device ID from super block */
494 dev_t dev;
495
496 /** Dentries in the control filesystem */
497 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
498
499 /** number of dentries used in the above array */
500 int ctl_ndents;
501
502 /** O_ASYNC requests */
503 struct fasync_struct *fasync;
504
505 /** Key for lock owner ID scrambling */
506 u32 scramble_key[4];
507
508 /** Reserved request for the DESTROY message */
509 struct fuse_req *destroy_req;
510
511 /** Version counter for attribute changes */
512 u64 attr_version;
513
514 /** Called on final put */
515 void (*release)(struct fuse_conn *);
516
517 /** Super block for this connection. */
518 struct super_block *sb;
519
520 /** Read/write semaphore to hold when accessing sb. */
521 struct rw_semaphore killsb;
522};
523
524static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
525{
526 return sb->s_fs_info;
527}
528
529static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
530{
531 return get_fuse_conn_super(inode->i_sb);
532}
533
534static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
535{
536 return container_of(inode, struct fuse_inode, inode);
537}
538
539static inline u64 get_node_id(struct inode *inode)
540{
541 return get_fuse_inode(inode)->nodeid;
542}
543
544/** Device operations */
545extern const struct file_operations fuse_dev_operations;
546
547extern const struct dentry_operations fuse_dentry_operations;
548
549/**
550 * Inode to nodeid comparison.
551 */
552int fuse_inode_eq(struct inode *inode, void *_nodeidp);
553
554/**
555 * Get a filled in inode
556 */
557struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
558 int generation, struct fuse_attr *attr,
559 u64 attr_valid, u64 attr_version);
560
561int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
562 struct fuse_entry_out *outarg, struct inode **inode);
563
564/**
565 * Send FORGET command
566 */
567void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
568 u64 nodeid, u64 nlookup);
569
570struct fuse_forget_link *fuse_alloc_forget(void);
571
572/**
573 * Initialize READ or READDIR request
574 */
575void fuse_read_fill(struct fuse_req *req, struct file *file,
576 loff_t pos, size_t count, int opcode);
577
578/**
579 * Send OPEN or OPENDIR request
580 */
581int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
582
583struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
584struct fuse_file *fuse_file_get(struct fuse_file *ff);
585void fuse_file_free(struct fuse_file *ff);
586void fuse_finish_open(struct inode *inode, struct file *file);
587
588void fuse_sync_release(struct fuse_file *ff, int flags);
589
590/**
591 * Send RELEASE or RELEASEDIR request
592 */
593void fuse_release_common(struct file *file, int opcode);
594
595/**
596 * Send FSYNC or FSYNCDIR request
597 */
598int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
599 int datasync, int isdir);
600
601/**
602 * Notify poll wakeup
603 */
604int fuse_notify_poll_wakeup(struct fuse_conn *fc,
605 struct fuse_notify_poll_wakeup_out *outarg);
606
607/**
608 * Initialize file operations on a regular file
609 */
610void fuse_init_file_inode(struct inode *inode);
611
612/**
613 * Initialize inode operations on regular files and special files
614 */
615void fuse_init_common(struct inode *inode);
616
617/**
618 * Initialize inode and file operations on a directory
619 */
620void fuse_init_dir(struct inode *inode);
621
622/**
623 * Initialize inode operations on a symlink
624 */
625void fuse_init_symlink(struct inode *inode);
626
627/**
628 * Change attributes of an inode
629 */
630void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
631 u64 attr_valid, u64 attr_version);
632
633void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
634 u64 attr_valid);
635
636/**
637 * Initialize the client device
638 */
639int fuse_dev_init(void);
640
641/**
642 * Cleanup the client device
643 */
644void fuse_dev_cleanup(void);
645
646int fuse_ctl_init(void);
647void fuse_ctl_cleanup(void);
648
649/**
650 * Allocate a request
651 */
652struct fuse_req *fuse_request_alloc(void);
653
654struct fuse_req *fuse_request_alloc_nofs(void);
655
656/**
657 * Free a request
658 */
659void fuse_request_free(struct fuse_req *req);
660
661/**
662 * Get a request, may fail with -ENOMEM
663 */
664struct fuse_req *fuse_get_req(struct fuse_conn *fc);
665
666/**
667 * Gets a requests for a file operation, always succeeds
668 */
669struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file);
670
671/**
672 * Decrement reference count of a request. If count goes to zero free
673 * the request.
674 */
675void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
676
677/**
678 * Send a request (synchronous)
679 */
680void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
681
682/**
683 * Send a request in the background
684 */
685void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
686
687void fuse_request_send_background_locked(struct fuse_conn *fc,
688 struct fuse_req *req);
689
690/* Abort all requests */
691void fuse_abort_conn(struct fuse_conn *fc);
692
693/**
694 * Invalidate inode attributes
695 */
696void fuse_invalidate_attr(struct inode *inode);
697
698void fuse_invalidate_entry_cache(struct dentry *entry);
699
700/**
701 * Acquire reference to fuse_conn
702 */
703struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
704
705void fuse_conn_kill(struct fuse_conn *fc);
706
707/**
708 * Initialize fuse_conn
709 */
710void fuse_conn_init(struct fuse_conn *fc);
711
712/**
713 * Release reference to fuse_conn
714 */
715void fuse_conn_put(struct fuse_conn *fc);
716
717/**
718 * Add connection to control filesystem
719 */
720int fuse_ctl_add_conn(struct fuse_conn *fc);
721
722/**
723 * Remove connection from control filesystem
724 */
725void fuse_ctl_remove_conn(struct fuse_conn *fc);
726
727/**
728 * Is file type valid?
729 */
730int fuse_valid_type(int m);
731
732/**
733 * Is task allowed to perform filesystem operation?
734 */
735int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task);
736
737u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
738
739int fuse_update_attributes(struct inode *inode, struct kstat *stat,
740 struct file *file, bool *refreshed);
741
742void fuse_flush_writepages(struct inode *inode);
743
744void fuse_set_nowrite(struct inode *inode);
745void fuse_release_nowrite(struct inode *inode);
746
747u64 fuse_get_attr_version(struct fuse_conn *fc);
748
749/**
750 * File-system tells the kernel to invalidate cache for the given node id.
751 */
752int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
753 loff_t offset, loff_t len);
754
755/**
756 * File-system tells the kernel to invalidate parent attributes and
757 * the dentry matching parent/name.
758 */
759int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
760 struct qstr *name);
761
762int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
763 bool isdir);
764ssize_t fuse_direct_io(struct file *file, const char __user *buf,
765 size_t count, loff_t *ppos, int write);
766long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
767 unsigned int flags);
768unsigned fuse_file_poll(struct file *file, poll_table *wait);
769int fuse_dev_release(struct inode *inode, struct file *file);
770
771void fuse_write_update_size(struct inode *inode, loff_t pos);
772
773#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#ifdef CONFIG_FUSE_DAX
153 /*
154 * Dax specific inode data
155 */
156 struct fuse_inode_dax *dax;
157#endif
158};
159
160/** FUSE inode state bits */
161enum {
162 /** Advise readdirplus */
163 FUSE_I_ADVISE_RDPLUS,
164 /** Initialized with readdirplus */
165 FUSE_I_INIT_RDPLUS,
166 /** An operation changing file size is in progress */
167 FUSE_I_SIZE_UNSTABLE,
168 /* Bad inode */
169 FUSE_I_BAD,
170};
171
172struct fuse_conn;
173struct fuse_mount;
174struct fuse_release_args;
175
176/** FUSE specific file data */
177struct fuse_file {
178 /** Fuse connection for this file */
179 struct fuse_mount *fm;
180
181 /* Argument space reserved for release */
182 struct fuse_release_args *release_args;
183
184 /** Kernel file handle guaranteed to be unique */
185 u64 kh;
186
187 /** File handle used by userspace */
188 u64 fh;
189
190 /** Node id of this file */
191 u64 nodeid;
192
193 /** Refcount */
194 refcount_t count;
195
196 /** FOPEN_* flags returned by open */
197 u32 open_flags;
198
199 /** Entry on inode's write_files list */
200 struct list_head write_entry;
201
202 /* Readdir related */
203 struct {
204 /*
205 * Protects below fields against (crazy) parallel readdir on
206 * same open file. Uncontended in the normal case.
207 */
208 struct mutex lock;
209
210 /* Dir stream position */
211 loff_t pos;
212
213 /* Offset in cache */
214 loff_t cache_off;
215
216 /* Version of cache we are reading */
217 u64 version;
218
219 } readdir;
220
221 /** RB node to be linked on fuse_conn->polled_files */
222 struct rb_node polled_node;
223
224 /** Wait queue head for poll */
225 wait_queue_head_t poll_wait;
226
227 /** Has flock been performed on this file? */
228 bool flock:1;
229};
230
231/** One input argument of a request */
232struct fuse_in_arg {
233 unsigned size;
234 const void *value;
235};
236
237/** One output argument of a request */
238struct fuse_arg {
239 unsigned size;
240 void *value;
241};
242
243/** FUSE page descriptor */
244struct fuse_page_desc {
245 unsigned int length;
246 unsigned int offset;
247};
248
249struct fuse_args {
250 uint64_t nodeid;
251 uint32_t opcode;
252 unsigned short in_numargs;
253 unsigned short out_numargs;
254 bool force:1;
255 bool noreply:1;
256 bool nocreds:1;
257 bool in_pages:1;
258 bool out_pages:1;
259 bool user_pages:1;
260 bool out_argvar:1;
261 bool page_zeroing:1;
262 bool page_replace:1;
263 bool may_block:1;
264 struct fuse_in_arg in_args[3];
265 struct fuse_arg out_args[2];
266 void (*end)(struct fuse_mount *fm, struct fuse_args *args, int error);
267};
268
269struct fuse_args_pages {
270 struct fuse_args args;
271 struct page **pages;
272 struct fuse_page_desc *descs;
273 unsigned int num_pages;
274};
275
276#define FUSE_ARGS(args) struct fuse_args args = {}
277
278/** The request IO state (for asynchronous processing) */
279struct fuse_io_priv {
280 struct kref refcnt;
281 int async;
282 spinlock_t lock;
283 unsigned reqs;
284 ssize_t bytes;
285 size_t size;
286 __u64 offset;
287 bool write;
288 bool should_dirty;
289 int err;
290 struct kiocb *iocb;
291 struct completion *done;
292 bool blocking;
293};
294
295#define FUSE_IO_PRIV_SYNC(i) \
296{ \
297 .refcnt = KREF_INIT(1), \
298 .async = 0, \
299 .iocb = i, \
300}
301
302/**
303 * Request flags
304 *
305 * FR_ISREPLY: set if the request has reply
306 * FR_FORCE: force sending of the request even if interrupted
307 * FR_BACKGROUND: request is sent in the background
308 * FR_WAITING: request is counted as "waiting"
309 * FR_ABORTED: the request was aborted
310 * FR_INTERRUPTED: the request has been interrupted
311 * FR_LOCKED: data is being copied to/from the request
312 * FR_PENDING: request is not yet in userspace
313 * FR_SENT: request is in userspace, waiting for an answer
314 * FR_FINISHED: request is finished
315 * FR_PRIVATE: request is on private list
316 * FR_ASYNC: request is asynchronous
317 */
318enum fuse_req_flag {
319 FR_ISREPLY,
320 FR_FORCE,
321 FR_BACKGROUND,
322 FR_WAITING,
323 FR_ABORTED,
324 FR_INTERRUPTED,
325 FR_LOCKED,
326 FR_PENDING,
327 FR_SENT,
328 FR_FINISHED,
329 FR_PRIVATE,
330 FR_ASYNC,
331};
332
333/**
334 * A request to the client
335 *
336 * .waitq.lock protects the following fields:
337 * - FR_ABORTED
338 * - FR_LOCKED (may also be modified under fc->lock, tested under both)
339 */
340struct fuse_req {
341 /** This can be on either pending processing or io lists in
342 fuse_conn */
343 struct list_head list;
344
345 /** Entry on the interrupts list */
346 struct list_head intr_entry;
347
348 /* Input/output arguments */
349 struct fuse_args *args;
350
351 /** refcount */
352 refcount_t count;
353
354 /* Request flags, updated with test/set/clear_bit() */
355 unsigned long flags;
356
357 /* The request input header */
358 struct {
359 struct fuse_in_header h;
360 } in;
361
362 /* The request output header */
363 struct {
364 struct fuse_out_header h;
365 } out;
366
367 /** Used to wake up the task waiting for completion of request*/
368 wait_queue_head_t waitq;
369
370#if IS_ENABLED(CONFIG_VIRTIO_FS)
371 /** virtio-fs's physically contiguous buffer for in and out args */
372 void *argbuf;
373#endif
374
375 /** fuse_mount this request belongs to */
376 struct fuse_mount *fm;
377};
378
379struct fuse_iqueue;
380
381/**
382 * Input queue callbacks
383 *
384 * Input queue signalling is device-specific. For example, the /dev/fuse file
385 * uses fiq->waitq and fasync to wake processes that are waiting on queue
386 * readiness. These callbacks allow other device types to respond to input
387 * queue activity.
388 */
389struct fuse_iqueue_ops {
390 /**
391 * Signal that a forget has been queued
392 */
393 void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
394 __releases(fiq->lock);
395
396 /**
397 * Signal that an INTERRUPT request has been queued
398 */
399 void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
400 __releases(fiq->lock);
401
402 /**
403 * Signal that a request has been queued
404 */
405 void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
406 __releases(fiq->lock);
407
408 /**
409 * Clean up when fuse_iqueue is destroyed
410 */
411 void (*release)(struct fuse_iqueue *fiq);
412};
413
414/** /dev/fuse input queue operations */
415extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
416
417struct fuse_iqueue {
418 /** Connection established */
419 unsigned connected;
420
421 /** Lock protecting accesses to members of this structure */
422 spinlock_t lock;
423
424 /** Readers of the connection are waiting on this */
425 wait_queue_head_t waitq;
426
427 /** The next unique request id */
428 u64 reqctr;
429
430 /** The list of pending requests */
431 struct list_head pending;
432
433 /** Pending interrupts */
434 struct list_head interrupts;
435
436 /** Queue of pending forgets */
437 struct fuse_forget_link forget_list_head;
438 struct fuse_forget_link *forget_list_tail;
439
440 /** Batching of FORGET requests (positive indicates FORGET batch) */
441 int forget_batch;
442
443 /** O_ASYNC requests */
444 struct fasync_struct *fasync;
445
446 /** Device-specific callbacks */
447 const struct fuse_iqueue_ops *ops;
448
449 /** Device-specific state */
450 void *priv;
451};
452
453#define FUSE_PQ_HASH_BITS 8
454#define FUSE_PQ_HASH_SIZE (1 << FUSE_PQ_HASH_BITS)
455
456struct fuse_pqueue {
457 /** Connection established */
458 unsigned connected;
459
460 /** Lock protecting accessess to members of this structure */
461 spinlock_t lock;
462
463 /** Hash table of requests being processed */
464 struct list_head *processing;
465
466 /** The list of requests under I/O */
467 struct list_head io;
468};
469
470/**
471 * Fuse device instance
472 */
473struct fuse_dev {
474 /** Fuse connection for this device */
475 struct fuse_conn *fc;
476
477 /** Processing queue */
478 struct fuse_pqueue pq;
479
480 /** list entry on fc->devices */
481 struct list_head entry;
482};
483
484enum fuse_dax_mode {
485 FUSE_DAX_INODE_DEFAULT, /* default */
486 FUSE_DAX_ALWAYS, /* "-o dax=always" */
487 FUSE_DAX_NEVER, /* "-o dax=never" */
488 FUSE_DAX_INODE_USER, /* "-o dax=inode" */
489};
490
491static inline bool fuse_is_inode_dax_mode(enum fuse_dax_mode mode)
492{
493 return mode == FUSE_DAX_INODE_DEFAULT || mode == FUSE_DAX_INODE_USER;
494}
495
496struct fuse_fs_context {
497 int fd;
498 struct file *file;
499 unsigned int rootmode;
500 kuid_t user_id;
501 kgid_t group_id;
502 bool is_bdev:1;
503 bool fd_present:1;
504 bool rootmode_present:1;
505 bool user_id_present:1;
506 bool group_id_present:1;
507 bool default_permissions:1;
508 bool allow_other:1;
509 bool destroy:1;
510 bool no_control:1;
511 bool no_force_umount:1;
512 bool legacy_opts_show:1;
513 enum fuse_dax_mode dax_mode;
514 unsigned int max_read;
515 unsigned int blksize;
516 const char *subtype;
517
518 /* DAX device, may be NULL */
519 struct dax_device *dax_dev;
520
521 /* fuse_dev pointer to fill in, should contain NULL on entry */
522 void **fudptr;
523};
524
525struct fuse_sync_bucket {
526 /* count is a possible scalability bottleneck */
527 atomic_t count;
528 wait_queue_head_t waitq;
529 struct rcu_head rcu;
530};
531
532/**
533 * A Fuse connection.
534 *
535 * This structure is created, when the root filesystem is mounted, and
536 * is destroyed, when the client device is closed and the last
537 * fuse_mount is destroyed.
538 */
539struct fuse_conn {
540 /** Lock protecting accessess to members of this structure */
541 spinlock_t lock;
542
543 /** Refcount */
544 refcount_t count;
545
546 /** Number of fuse_dev's */
547 atomic_t dev_count;
548
549 struct rcu_head rcu;
550
551 /** The user id for this mount */
552 kuid_t user_id;
553
554 /** The group id for this mount */
555 kgid_t group_id;
556
557 /** The pid namespace for this mount */
558 struct pid_namespace *pid_ns;
559
560 /** The user namespace for this mount */
561 struct user_namespace *user_ns;
562
563 /** Maximum read size */
564 unsigned max_read;
565
566 /** Maximum write size */
567 unsigned max_write;
568
569 /** Maximum number of pages that can be used in a single request */
570 unsigned int max_pages;
571
572 /** Constrain ->max_pages to this value during feature negotiation */
573 unsigned int max_pages_limit;
574
575 /** Input queue */
576 struct fuse_iqueue iq;
577
578 /** The next unique kernel file handle */
579 atomic64_t khctr;
580
581 /** rbtree of fuse_files waiting for poll events indexed by ph */
582 struct rb_root polled_files;
583
584 /** Maximum number of outstanding background requests */
585 unsigned max_background;
586
587 /** Number of background requests at which congestion starts */
588 unsigned congestion_threshold;
589
590 /** Number of requests currently in the background */
591 unsigned num_background;
592
593 /** Number of background requests currently queued for userspace */
594 unsigned active_background;
595
596 /** The list of background requests set aside for later queuing */
597 struct list_head bg_queue;
598
599 /** Protects: max_background, congestion_threshold, num_background,
600 * active_background, bg_queue, blocked */
601 spinlock_t bg_lock;
602
603 /** Flag indicating that INIT reply has been received. Allocating
604 * any fuse request will be suspended until the flag is set */
605 int initialized;
606
607 /** Flag indicating if connection is blocked. This will be
608 the case before the INIT reply is received, and if there
609 are too many outstading backgrounds requests */
610 int blocked;
611
612 /** waitq for blocked connection */
613 wait_queue_head_t blocked_waitq;
614
615 /** Connection established, cleared on umount, connection
616 abort and device release */
617 unsigned connected;
618
619 /** Connection aborted via sysfs */
620 bool aborted;
621
622 /** Connection failed (version mismatch). Cannot race with
623 setting other bitfields since it is only set once in INIT
624 reply, before any other request, and never cleared */
625 unsigned conn_error:1;
626
627 /** Connection successful. Only set in INIT */
628 unsigned conn_init:1;
629
630 /** Do readahead asynchronously? Only set in INIT */
631 unsigned async_read:1;
632
633 /** Return an unique read error after abort. Only set in INIT */
634 unsigned abort_err:1;
635
636 /** Do not send separate SETATTR request before open(O_TRUNC) */
637 unsigned atomic_o_trunc:1;
638
639 /** Filesystem supports NFS exporting. Only set in INIT */
640 unsigned export_support:1;
641
642 /** write-back cache policy (default is write-through) */
643 unsigned writeback_cache:1;
644
645 /** allow parallel lookups and readdir (default is serialized) */
646 unsigned parallel_dirops:1;
647
648 /** handle fs handles killing suid/sgid/cap on write/chown/trunc */
649 unsigned handle_killpriv:1;
650
651 /** cache READLINK responses in page cache */
652 unsigned cache_symlinks:1;
653
654 /* show legacy mount options */
655 unsigned int legacy_opts_show:1;
656
657 /*
658 * fs kills suid/sgid/cap on write/chown/trunc. suid is killed on
659 * write/trunc only if caller did not have CAP_FSETID. sgid is killed
660 * on write/truncate only if caller did not have CAP_FSETID as well as
661 * file has group execute permission.
662 */
663 unsigned handle_killpriv_v2:1;
664
665 /*
666 * The following bitfields are only for optimization purposes
667 * and hence races in setting them will not cause malfunction
668 */
669
670 /** Is open/release not implemented by fs? */
671 unsigned no_open:1;
672
673 /** Is opendir/releasedir not implemented by fs? */
674 unsigned no_opendir:1;
675
676 /** Is fsync not implemented by fs? */
677 unsigned no_fsync:1;
678
679 /** Is fsyncdir not implemented by fs? */
680 unsigned no_fsyncdir:1;
681
682 /** Is flush not implemented by fs? */
683 unsigned no_flush:1;
684
685 /** Is setxattr not implemented by fs? */
686 unsigned no_setxattr:1;
687
688 /** Does file server support extended setxattr */
689 unsigned setxattr_ext:1;
690
691 /** Is getxattr not implemented by fs? */
692 unsigned no_getxattr:1;
693
694 /** Is listxattr not implemented by fs? */
695 unsigned no_listxattr:1;
696
697 /** Is removexattr not implemented by fs? */
698 unsigned no_removexattr:1;
699
700 /** Are posix file locking primitives not implemented by fs? */
701 unsigned no_lock:1;
702
703 /** Is access not implemented by fs? */
704 unsigned no_access:1;
705
706 /** Is create not implemented by fs? */
707 unsigned no_create:1;
708
709 /** Is interrupt not implemented by fs? */
710 unsigned no_interrupt:1;
711
712 /** Is bmap not implemented by fs? */
713 unsigned no_bmap:1;
714
715 /** Is poll not implemented by fs? */
716 unsigned no_poll:1;
717
718 /** Do multi-page cached writes */
719 unsigned big_writes:1;
720
721 /** Don't apply umask to creation modes */
722 unsigned dont_mask:1;
723
724 /** Are BSD file locking primitives not implemented by fs? */
725 unsigned no_flock:1;
726
727 /** Is fallocate not implemented by fs? */
728 unsigned no_fallocate:1;
729
730 /** Is rename with flags implemented by fs? */
731 unsigned no_rename2:1;
732
733 /** Use enhanced/automatic page cache invalidation. */
734 unsigned auto_inval_data:1;
735
736 /** Filesystem is fully responsible for page cache invalidation. */
737 unsigned explicit_inval_data:1;
738
739 /** Does the filesystem support readdirplus? */
740 unsigned do_readdirplus:1;
741
742 /** Does the filesystem want adaptive readdirplus? */
743 unsigned readdirplus_auto:1;
744
745 /** Does the filesystem support asynchronous direct-IO submission? */
746 unsigned async_dio:1;
747
748 /** Is lseek not implemented by fs? */
749 unsigned no_lseek:1;
750
751 /** Does the filesystem support posix acls? */
752 unsigned posix_acl:1;
753
754 /** Check permissions based on the file mode or not? */
755 unsigned default_permissions:1;
756
757 /** Allow other than the mounter user to access the filesystem ? */
758 unsigned allow_other:1;
759
760 /** Does the filesystem support copy_file_range? */
761 unsigned no_copy_file_range:1;
762
763 /* Send DESTROY request */
764 unsigned int destroy:1;
765
766 /* Delete dentries that have gone stale */
767 unsigned int delete_stale:1;
768
769 /** Do not create entry in fusectl fs */
770 unsigned int no_control:1;
771
772 /** Do not allow MNT_FORCE umount */
773 unsigned int no_force_umount:1;
774
775 /* Auto-mount submounts announced by the server */
776 unsigned int auto_submounts:1;
777
778 /* Propagate syncfs() to server */
779 unsigned int sync_fs:1;
780
781 /* Initialize security xattrs when creating a new inode */
782 unsigned int init_security:1;
783
784 /* Does the filesystem support per inode DAX? */
785 unsigned int inode_dax:1;
786
787 /* Is tmpfile not implemented by fs? */
788 unsigned int no_tmpfile:1;
789
790 /** The number of requests waiting for completion */
791 atomic_t num_waiting;
792
793 /** Negotiated minor version */
794 unsigned minor;
795
796 /** Entry on the fuse_mount_list */
797 struct list_head entry;
798
799 /** Device ID from the root super block */
800 dev_t dev;
801
802 /** Dentries in the control filesystem */
803 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
804
805 /** number of dentries used in the above array */
806 int ctl_ndents;
807
808 /** Key for lock owner ID scrambling */
809 u32 scramble_key[4];
810
811 /** Version counter for attribute changes */
812 atomic64_t attr_version;
813
814 /** Called on final put */
815 void (*release)(struct fuse_conn *);
816
817 /**
818 * Read/write semaphore to hold when accessing the sb of any
819 * fuse_mount belonging to this connection
820 */
821 struct rw_semaphore killsb;
822
823 /** List of device instances belonging to this connection */
824 struct list_head devices;
825
826#ifdef CONFIG_FUSE_DAX
827 /* Dax mode */
828 enum fuse_dax_mode dax_mode;
829
830 /* Dax specific conn data, non-NULL if DAX is enabled */
831 struct fuse_conn_dax *dax;
832#endif
833
834 /** List of filesystems using this connection */
835 struct list_head mounts;
836
837 /* New writepages go into this bucket */
838 struct fuse_sync_bucket __rcu *curr_bucket;
839};
840
841/*
842 * Represents a mounted filesystem, potentially a submount.
843 *
844 * This object allows sharing a fuse_conn between separate mounts to
845 * allow submounts with dedicated superblocks and thus separate device
846 * IDs.
847 */
848struct fuse_mount {
849 /* Underlying (potentially shared) connection to the FUSE server */
850 struct fuse_conn *fc;
851
852 /*
853 * Super block for this connection (fc->killsb must be held when
854 * accessing this).
855 */
856 struct super_block *sb;
857
858 /* Entry on fc->mounts */
859 struct list_head fc_entry;
860};
861
862static inline struct fuse_mount *get_fuse_mount_super(struct super_block *sb)
863{
864 return sb->s_fs_info;
865}
866
867static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
868{
869 return get_fuse_mount_super(sb)->fc;
870}
871
872static inline struct fuse_mount *get_fuse_mount(struct inode *inode)
873{
874 return get_fuse_mount_super(inode->i_sb);
875}
876
877static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
878{
879 return get_fuse_mount_super(inode->i_sb)->fc;
880}
881
882static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
883{
884 return container_of(inode, struct fuse_inode, inode);
885}
886
887static inline u64 get_node_id(struct inode *inode)
888{
889 return get_fuse_inode(inode)->nodeid;
890}
891
892static inline int invalid_nodeid(u64 nodeid)
893{
894 return !nodeid || nodeid == FUSE_ROOT_ID;
895}
896
897static inline u64 fuse_get_attr_version(struct fuse_conn *fc)
898{
899 return atomic64_read(&fc->attr_version);
900}
901
902static inline bool fuse_stale_inode(const struct inode *inode, int generation,
903 struct fuse_attr *attr)
904{
905 return inode->i_generation != generation ||
906 inode_wrong_type(inode, attr->mode);
907}
908
909static inline void fuse_make_bad(struct inode *inode)
910{
911 remove_inode_hash(inode);
912 set_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state);
913}
914
915static inline bool fuse_is_bad(struct inode *inode)
916{
917 return unlikely(test_bit(FUSE_I_BAD, &get_fuse_inode(inode)->state));
918}
919
920static inline struct page **fuse_pages_alloc(unsigned int npages, gfp_t flags,
921 struct fuse_page_desc **desc)
922{
923 struct page **pages;
924
925 pages = kzalloc(npages * (sizeof(struct page *) +
926 sizeof(struct fuse_page_desc)), flags);
927 *desc = (void *) (pages + npages);
928
929 return pages;
930}
931
932static inline void fuse_page_descs_length_init(struct fuse_page_desc *descs,
933 unsigned int index,
934 unsigned int nr_pages)
935{
936 int i;
937
938 for (i = index; i < index + nr_pages; i++)
939 descs[i].length = PAGE_SIZE - descs[i].offset;
940}
941
942static inline void fuse_sync_bucket_dec(struct fuse_sync_bucket *bucket)
943{
944 /* Need RCU protection to prevent use after free after the decrement */
945 rcu_read_lock();
946 if (atomic_dec_and_test(&bucket->count))
947 wake_up(&bucket->waitq);
948 rcu_read_unlock();
949}
950
951/** Device operations */
952extern const struct file_operations fuse_dev_operations;
953
954extern const struct dentry_operations fuse_dentry_operations;
955extern const struct dentry_operations fuse_root_dentry_operations;
956
957/**
958 * Get a filled in inode
959 */
960struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
961 int generation, struct fuse_attr *attr,
962 u64 attr_valid, u64 attr_version);
963
964int fuse_lookup_name(struct super_block *sb, u64 nodeid, const struct qstr *name,
965 struct fuse_entry_out *outarg, struct inode **inode);
966
967/**
968 * Send FORGET command
969 */
970void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
971 u64 nodeid, u64 nlookup);
972
973struct fuse_forget_link *fuse_alloc_forget(void);
974
975struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
976 unsigned int max,
977 unsigned int *countp);
978
979/*
980 * Initialize READ or READDIR request
981 */
982struct fuse_io_args {
983 union {
984 struct {
985 struct fuse_read_in in;
986 u64 attr_ver;
987 } read;
988 struct {
989 struct fuse_write_in in;
990 struct fuse_write_out out;
991 bool page_locked;
992 } write;
993 };
994 struct fuse_args_pages ap;
995 struct fuse_io_priv *io;
996 struct fuse_file *ff;
997};
998
999void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
1000 size_t count, int opcode);
1001
1002
1003/**
1004 * Send OPEN or OPENDIR request
1005 */
1006int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
1007
1008struct fuse_file *fuse_file_alloc(struct fuse_mount *fm);
1009void fuse_file_free(struct fuse_file *ff);
1010void fuse_finish_open(struct inode *inode, struct file *file);
1011
1012void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
1013 unsigned int flags);
1014
1015/**
1016 * Send RELEASE or RELEASEDIR request
1017 */
1018void fuse_release_common(struct file *file, bool isdir);
1019
1020/**
1021 * Send FSYNC or FSYNCDIR request
1022 */
1023int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
1024 int datasync, int opcode);
1025
1026/**
1027 * Notify poll wakeup
1028 */
1029int fuse_notify_poll_wakeup(struct fuse_conn *fc,
1030 struct fuse_notify_poll_wakeup_out *outarg);
1031
1032/**
1033 * Initialize file operations on a regular file
1034 */
1035void fuse_init_file_inode(struct inode *inode, unsigned int flags);
1036
1037/**
1038 * Initialize inode operations on regular files and special files
1039 */
1040void fuse_init_common(struct inode *inode);
1041
1042/**
1043 * Initialize inode and file operations on a directory
1044 */
1045void fuse_init_dir(struct inode *inode);
1046
1047/**
1048 * Initialize inode operations on a symlink
1049 */
1050void fuse_init_symlink(struct inode *inode);
1051
1052/**
1053 * Change attributes of an inode
1054 */
1055void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
1056 u64 attr_valid, u64 attr_version);
1057
1058void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
1059 u64 attr_valid, u32 cache_mask);
1060
1061u32 fuse_get_cache_mask(struct inode *inode);
1062
1063/**
1064 * Initialize the client device
1065 */
1066int fuse_dev_init(void);
1067
1068/**
1069 * Cleanup the client device
1070 */
1071void fuse_dev_cleanup(void);
1072
1073int fuse_ctl_init(void);
1074void __exit fuse_ctl_cleanup(void);
1075
1076/**
1077 * Simple request sending that does request allocation and freeing
1078 */
1079ssize_t fuse_simple_request(struct fuse_mount *fm, struct fuse_args *args);
1080int fuse_simple_background(struct fuse_mount *fm, struct fuse_args *args,
1081 gfp_t gfp_flags);
1082
1083/**
1084 * End a finished request
1085 */
1086void fuse_request_end(struct fuse_req *req);
1087
1088/* Abort all requests */
1089void fuse_abort_conn(struct fuse_conn *fc);
1090void fuse_wait_aborted(struct fuse_conn *fc);
1091
1092/**
1093 * Invalidate inode attributes
1094 */
1095
1096/* Attributes possibly changed on data modification */
1097#define FUSE_STATX_MODIFY (STATX_MTIME | STATX_CTIME | STATX_BLOCKS)
1098
1099/* Attributes possibly changed on data and/or size modification */
1100#define FUSE_STATX_MODSIZE (FUSE_STATX_MODIFY | STATX_SIZE)
1101
1102void fuse_invalidate_attr(struct inode *inode);
1103void fuse_invalidate_attr_mask(struct inode *inode, u32 mask);
1104
1105void fuse_invalidate_entry_cache(struct dentry *entry);
1106
1107void fuse_invalidate_atime(struct inode *inode);
1108
1109u64 entry_attr_timeout(struct fuse_entry_out *o);
1110void fuse_change_entry_timeout(struct dentry *entry, struct fuse_entry_out *o);
1111
1112/**
1113 * Acquire reference to fuse_conn
1114 */
1115struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
1116
1117/**
1118 * Initialize fuse_conn
1119 */
1120void fuse_conn_init(struct fuse_conn *fc, struct fuse_mount *fm,
1121 struct user_namespace *user_ns,
1122 const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
1123
1124/**
1125 * Release reference to fuse_conn
1126 */
1127void fuse_conn_put(struct fuse_conn *fc);
1128
1129struct fuse_dev *fuse_dev_alloc_install(struct fuse_conn *fc);
1130struct fuse_dev *fuse_dev_alloc(void);
1131void fuse_dev_install(struct fuse_dev *fud, struct fuse_conn *fc);
1132void fuse_dev_free(struct fuse_dev *fud);
1133void fuse_send_init(struct fuse_mount *fm);
1134
1135/**
1136 * Fill in superblock and initialize fuse connection
1137 * @sb: partially-initialized superblock to fill in
1138 * @ctx: mount context
1139 */
1140int fuse_fill_super_common(struct super_block *sb, struct fuse_fs_context *ctx);
1141
1142/*
1143 * Remove the mount from the connection
1144 *
1145 * Returns whether this was the last mount
1146 */
1147bool fuse_mount_remove(struct fuse_mount *fm);
1148
1149/*
1150 * Setup context ops for submounts
1151 */
1152int fuse_init_fs_context_submount(struct fs_context *fsc);
1153
1154/*
1155 * Shut down the connection (possibly sending DESTROY request).
1156 */
1157void fuse_conn_destroy(struct fuse_mount *fm);
1158
1159/* Drop the connection and free the fuse mount */
1160void fuse_mount_destroy(struct fuse_mount *fm);
1161
1162/**
1163 * Add connection to control filesystem
1164 */
1165int fuse_ctl_add_conn(struct fuse_conn *fc);
1166
1167/**
1168 * Remove connection from control filesystem
1169 */
1170void fuse_ctl_remove_conn(struct fuse_conn *fc);
1171
1172/**
1173 * Is file type valid?
1174 */
1175int fuse_valid_type(int m);
1176
1177bool fuse_invalid_attr(struct fuse_attr *attr);
1178
1179/**
1180 * Is current process allowed to perform filesystem operation?
1181 */
1182bool fuse_allow_current_process(struct fuse_conn *fc);
1183
1184u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
1185
1186void fuse_flush_time_update(struct inode *inode);
1187void fuse_update_ctime(struct inode *inode);
1188
1189int fuse_update_attributes(struct inode *inode, struct file *file, u32 mask);
1190
1191void fuse_flush_writepages(struct inode *inode);
1192
1193void fuse_set_nowrite(struct inode *inode);
1194void fuse_release_nowrite(struct inode *inode);
1195
1196/**
1197 * Scan all fuse_mounts belonging to fc to find the first where
1198 * ilookup5() returns a result. Return that result and the
1199 * respective fuse_mount in *fm (unless fm is NULL).
1200 *
1201 * The caller must hold fc->killsb.
1202 */
1203struct inode *fuse_ilookup(struct fuse_conn *fc, u64 nodeid,
1204 struct fuse_mount **fm);
1205
1206/**
1207 * File-system tells the kernel to invalidate cache for the given node id.
1208 */
1209int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
1210 loff_t offset, loff_t len);
1211
1212/**
1213 * File-system tells the kernel to invalidate parent attributes and
1214 * the dentry matching parent/name.
1215 *
1216 * If the child_nodeid is non-zero and:
1217 * - matches the inode number for the dentry matching parent/name,
1218 * - is not a mount point
1219 * - is a file or oan empty directory
1220 * then the dentry is unhashed (d_delete()).
1221 */
1222int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
1223 u64 child_nodeid, struct qstr *name, u32 flags);
1224
1225int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
1226 bool isdir);
1227
1228/**
1229 * fuse_direct_io() flags
1230 */
1231
1232/** If set, it is WRITE; otherwise - READ */
1233#define FUSE_DIO_WRITE (1 << 0)
1234
1235/** CUSE pass fuse_direct_io() a file which f_mapping->host is not from FUSE */
1236#define FUSE_DIO_CUSE (1 << 1)
1237
1238ssize_t fuse_direct_io(struct fuse_io_priv *io, struct iov_iter *iter,
1239 loff_t *ppos, int flags);
1240long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,
1241 unsigned int flags);
1242long fuse_ioctl_common(struct file *file, unsigned int cmd,
1243 unsigned long arg, unsigned int flags);
1244__poll_t fuse_file_poll(struct file *file, poll_table *wait);
1245int fuse_dev_release(struct inode *inode, struct file *file);
1246
1247bool fuse_write_update_attr(struct inode *inode, loff_t pos, ssize_t written);
1248
1249int fuse_flush_times(struct inode *inode, struct fuse_file *ff);
1250int fuse_write_inode(struct inode *inode, struct writeback_control *wbc);
1251
1252int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
1253 struct file *file);
1254
1255void fuse_set_initialized(struct fuse_conn *fc);
1256
1257void fuse_unlock_inode(struct inode *inode, bool locked);
1258bool fuse_lock_inode(struct inode *inode);
1259
1260int fuse_setxattr(struct inode *inode, const char *name, const void *value,
1261 size_t size, int flags, unsigned int extra_flags);
1262ssize_t fuse_getxattr(struct inode *inode, const char *name, void *value,
1263 size_t size);
1264ssize_t fuse_listxattr(struct dentry *entry, char *list, size_t size);
1265int fuse_removexattr(struct inode *inode, const char *name);
1266extern const struct xattr_handler *fuse_xattr_handlers[];
1267
1268struct posix_acl;
1269struct posix_acl *fuse_get_inode_acl(struct inode *inode, int type, bool rcu);
1270struct posix_acl *fuse_get_acl(struct user_namespace *mnt_userns,
1271 struct dentry *dentry, int type);
1272int fuse_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
1273 struct posix_acl *acl, int type);
1274
1275/* readdir.c */
1276int fuse_readdir(struct file *file, struct dir_context *ctx);
1277
1278/**
1279 * Return the number of bytes in an arguments list
1280 */
1281unsigned int fuse_len_args(unsigned int numargs, struct fuse_arg *args);
1282
1283/**
1284 * Get the next unique ID for a request
1285 */
1286u64 fuse_get_unique(struct fuse_iqueue *fiq);
1287void fuse_free_conn(struct fuse_conn *fc);
1288
1289/* dax.c */
1290
1291#define FUSE_IS_DAX(inode) (IS_ENABLED(CONFIG_FUSE_DAX) && IS_DAX(inode))
1292
1293ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to);
1294ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from);
1295int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma);
1296int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, u64 dmap_end);
1297int fuse_dax_conn_alloc(struct fuse_conn *fc, enum fuse_dax_mode mode,
1298 struct dax_device *dax_dev);
1299void fuse_dax_conn_free(struct fuse_conn *fc);
1300bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi);
1301void fuse_dax_inode_init(struct inode *inode, unsigned int flags);
1302void fuse_dax_inode_cleanup(struct inode *inode);
1303void fuse_dax_dontcache(struct inode *inode, unsigned int flags);
1304bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment);
1305void fuse_dax_cancel_work(struct fuse_conn *fc);
1306
1307/* ioctl.c */
1308long fuse_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1309long fuse_file_compat_ioctl(struct file *file, unsigned int cmd,
1310 unsigned long arg);
1311int fuse_fileattr_get(struct dentry *dentry, struct fileattr *fa);
1312int fuse_fileattr_set(struct user_namespace *mnt_userns,
1313 struct dentry *dentry, struct fileattr *fa);
1314
1315/* file.c */
1316
1317struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
1318 unsigned int open_flags, bool isdir);
1319void fuse_file_release(struct inode *inode, struct fuse_file *ff,
1320 unsigned int open_flags, fl_owner_t id, bool isdir);
1321
1322#endif /* _FS_FUSE_I_H */