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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#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 */