fuse_i.h 15.8 KB
Newer Older
Miklos Szeredi's avatar
Miklos Szeredi committed
1
2
/*
  FUSE: Filesystem in Userspace
Miklos Szeredi's avatar
Miklos Szeredi committed
3
  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
Miklos Szeredi's avatar
Miklos Szeredi committed
4
5
6
7
8

  This program can be distributed under the terms of the GNU GPL.
  See the file COPYING.
*/

Tejun Heo's avatar
Tejun Heo committed
9
10
11
#ifndef _FS_FUSE_I_H
#define _FS_FUSE_I_H

Miklos Szeredi's avatar
Miklos Szeredi committed
12
13
#include <linux/fuse.h>
#include <linux/fs.h>
14
#include <linux/mount.h>
Miklos Szeredi's avatar
Miklos Szeredi committed
15
16
17
18
19
#include <linux/wait.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/backing-dev.h>
20
#include <linux/mutex.h>
Miklos Szeredi's avatar
Miklos Szeredi committed
21
#include <linux/rwsem.h>
Tejun Heo's avatar
Tejun Heo committed
22
23
#include <linux/rbtree.h>
#include <linux/poll.h>
Miklos Szeredi's avatar
Miklos Szeredi committed
24

25
26
27
/** Max number of pages that can be used in a single read request */
#define FUSE_MAX_PAGES_PER_REQ 32

28
/** Maximum number of outstanding background requests */
29
30
31
32
#define FUSE_MAX_BACKGROUND 12

/** Congestion starts at 75% of maximum */
#define FUSE_CONGESTION_THRESHOLD (FUSE_MAX_BACKGROUND * 75 / 100)
33

Miklos Szeredi's avatar
Miklos Szeredi committed
34
35
36
/** Bias for fi->writectr, meaning new writepages must not be sent */
#define FUSE_NOWRITE INT_MIN

37
38
39
/** It could be as large as PATH_MAX, but would that have any uses? */
#define FUSE_NAME_MAX 1024

40
41
42
/** Number of dentries for each connection in the control filesystem */
#define FUSE_CTL_NUM_DENTRIES 3

Miklos Szeredi's avatar
Miklos Szeredi committed
43
44
45
46
47
48
49
50
51
/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
    module will check permissions based on the file mode.  Otherwise no
    permission checking is done in the kernel */
#define FUSE_DEFAULT_PERMISSIONS (1 << 0)

/** If the FUSE_ALLOW_OTHER flag is given, then not only the user
    doing the mount will be allowed to access the filesystem */
#define FUSE_ALLOW_OTHER         (1 << 1)

52
53
54
55
56
/** List of active connections */
extern struct list_head fuse_conn_list;

/** Global mutex protecting fuse_conn_list and the control filesystem */
extern struct mutex fuse_mutex;
Miklos Szeredi's avatar
Miklos Szeredi committed
57

Miklos Szeredi's avatar
Miklos Szeredi committed
58
59
60
61
62
63
64
65
66
/** FUSE inode */
struct fuse_inode {
	/** Inode data */
	struct inode inode;

	/** Unique ID, which identifies the inode between userspace
	 * and kernel */
	u64 nodeid;

67
68
69
	/** Number of lookups on this inode */
	u64 nlookup;

70
71
72
	/** The request used for sending the FORGET message */
	struct fuse_req *forget_req;

Miklos Szeredi's avatar
Miklos Szeredi committed
73
	/** Time in jiffies until the file attributes are valid */
Miklos Szeredi's avatar
Miklos Szeredi committed
74
	u64 i_time;
75
76
77
78

	/** The sticky bit in inode->i_mode may have been removed, so
	    preserve the original mode */
	mode_t orig_i_mode;
79
80
81

	/** Version of last attribute change */
	u64 attr_version;
82
83
84

	/** Files usable in writepage.  Protected by fc->lock */
	struct list_head write_files;
Miklos Szeredi's avatar
Miklos Szeredi committed
85
86
87
88
89
90
91
92
93
94
95
96
97

	/** Writepages pending on truncate or fsync */
	struct list_head queued_writes;

	/** Number of sent writes, a negative bias (FUSE_NOWRITE)
	 * means more writes are blocked */
	int writectr;

	/** Waitq for writepage completion */
	wait_queue_head_t page_waitq;

	/** List of writepage requestst (pending or sent) */
	struct list_head writepages;
Miklos Szeredi's avatar
Miklos Szeredi committed
98
99
};

100
101
102
/** FUSE specific file data */
struct fuse_file {
	/** Request reserved for flush and release */
103
	struct fuse_req *reserved_req;
104

Tejun Heo's avatar
Tejun Heo committed
105
106
107
	/** Kernel file handle guaranteed to be unique */
	u64 kh;

108
109
	/** File handle used by userspace */
	u64 fh;
110
111
112

	/** Refcount */
	atomic_t count;
113
114
115

	/** Entry on inode's write_files list */
	struct list_head write_entry;
Tejun Heo's avatar
Tejun Heo committed
116
117
118
119
120
121

	/** RB node to be linked on fuse_conn->polled_files */
	struct rb_node polled_node;

	/** Wait queue head for poll */
	wait_queue_head_t poll_wait;
122
123
};

124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
/** One input argument of a request */
struct fuse_in_arg {
	unsigned size;
	const void *value;
};

/** The request input */
struct fuse_in {
	/** The request header */
	struct fuse_in_header h;

	/** True if the data for the last argument is in req->pages */
	unsigned argpages:1;

	/** Number of arguments */
	unsigned numargs;

	/** Array of arguments */
	struct fuse_in_arg args[3];
};

/** One output argument of a request */
struct fuse_arg {
	unsigned size;
	void *value;
};

/** The request output */
struct fuse_out {
	/** Header returned from userspace */
	struct fuse_out_header h;

156
157
158
159
160
	/*
	 * The following bitfields are not changed during the request
	 * processing
	 */

161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
	/** Last argument is variable length (can be shorter than
	    arg->size) */
	unsigned argvar:1;

	/** Last argument is a list of pages to copy data to */
	unsigned argpages:1;

	/** Zero partially or not copied pages */
	unsigned page_zeroing:1;

	/** Number or arguments */
	unsigned numargs;

	/** Array of arguments */
	struct fuse_arg args[3];
};

178
179
180
181
182
183
/** The request state */
enum fuse_req_state {
	FUSE_REQ_INIT = 0,
	FUSE_REQ_PENDING,
	FUSE_REQ_READING,
	FUSE_REQ_SENT,
184
	FUSE_REQ_WRITING,
185
186
187
	FUSE_REQ_FINISHED
};

188
189
struct fuse_conn;

190
191
192
193
/**
 * A request to the client
 */
struct fuse_req {
194
195
	/** This can be on either pending processing or io lists in
	    fuse_conn */
196
197
	struct list_head list;

198
199
200
	/** Entry on the interrupts list  */
	struct list_head intr_entry;

201
202
203
	/** refcount */
	atomic_t count;

204
205
206
	/** Unique ID for the interrupt request */
	u64 intr_unique;

207
208
209
	/*
	 * The following bitfields are either set once before the
	 * request is queued or setting/clearing them is protected by
210
	 * fuse_conn->lock
211
212
	 */

213
214
215
	/** True if the request has reply */
	unsigned isreply:1;

216
217
218
	/** Force sending of the request even if interrupted */
	unsigned force:1;

219
220
	/** The request was aborted */
	unsigned aborted:1;
221
222
223
224

	/** Request is sent in the background */
	unsigned background:1;

225
226
227
	/** The request has been interrupted */
	unsigned interrupted:1;

228
229
230
	/** Data is being copied to/from the request */
	unsigned locked:1;

231
232
233
	/** Request is counted as "waiting" */
	unsigned waiting:1;

234
235
	/** State of the request */
	enum fuse_req_state state;
236
237
238
239
240
241
242
243
244
245
246
247

	/** The request input */
	struct fuse_in in;

	/** The request output */
	struct fuse_out out;

	/** Used to wake up the task waiting for completion of request*/
	wait_queue_head_t waitq;

	/** Data for asynchronous requests */
	union {
248
		struct fuse_forget_in forget_in;
249
250
251
252
253
		struct {
			struct fuse_release_in in;
			struct vfsmount *vfsmount;
			struct dentry *dentry;
		} release;
254
255
		struct fuse_init_in init_in;
		struct fuse_init_out init_out;
256
257
258
259
		struct {
			struct fuse_read_in in;
			u64 attr_ver;
		} read;
260
261
262
263
		struct {
			struct fuse_write_in in;
			struct fuse_write_out out;
		} write;
264
		struct fuse_lk_in lk_in;
265
266
267
268
269
270
271
272
273
274
275
276
	} misc;

	/** page vector */
	struct page *pages[FUSE_MAX_PAGES_PER_REQ];

	/** number of pages in vector */
	unsigned num_pages;

	/** offset of data on first page */
	unsigned page_offset;

	/** File used in the request (or NULL) */
277
	struct fuse_file *ff;
278

Miklos Szeredi's avatar
Miklos Szeredi committed
279
280
281
282
283
284
	/** Inode used in the request or NULL */
	struct inode *inode;

	/** Link on fi->writepages */
	struct list_head writepages_entry;

285
286
	/** Request completion callback */
	void (*end)(struct fuse_conn *, struct fuse_req *);
287
288
289

	/** Request is stolen from fuse_file->reserved_req */
	struct file *stolen_file;
290
291
};

Miklos Szeredi's avatar
Miklos Szeredi committed
292
293
294
295
296
297
298
299
/**
 * A Fuse connection.
 *
 * This structure is created, when the filesystem is mounted, and is
 * destroyed, when the client device is closed and the filesystem is
 * unmounted.
 */
struct fuse_conn {
300
301
302
	/** Lock protecting accessess to  members of this structure */
	spinlock_t lock;

303
304
305
	/** Mutex protecting against directory alias creation */
	struct mutex inst_mutex;

306
307
308
	/** Refcount */
	atomic_t count;

Miklos Szeredi's avatar
Miklos Szeredi committed
309
310
311
	/** The user id for this mount */
	uid_t user_id;

312
313
314
	/** The group id for this mount */
	gid_t group_id;

Miklos Szeredi's avatar
Miklos Szeredi committed
315
316
317
	/** The fuse mount flags for this mount */
	unsigned flags;

318
319
320
	/** Maximum read size */
	unsigned max_read;

Miklos Szeredi's avatar
Miklos Szeredi committed
321
322
323
	/** Maximum write size */
	unsigned max_write;

324
325
326
327
328
329
330
331
332
	/** Readers of the connection are waiting on this */
	wait_queue_head_t waitq;

	/** The list of pending requests */
	struct list_head pending;

	/** The list of requests being processed */
	struct list_head processing;

333
334
335
	/** The list of requests under I/O */
	struct list_head io;

Tejun Heo's avatar
Tejun Heo committed
336
337
338
	/** The next unique kernel file handle */
	u64 khctr;

Tejun Heo's avatar
Tejun Heo committed
339
340
341
	/** rbtree of fuse_files waiting for poll events indexed by ph */
	struct rb_root polled_files;

342
343
344
	/** Number of requests currently in the background */
	unsigned num_background;

345
346
347
348
349
350
	/** Number of background requests currently queued for userspace */
	unsigned active_background;

	/** The list of background requests set aside for later queuing */
	struct list_head bg_queue;

351
352
353
	/** Pending interrupts */
	struct list_head interrupts;

354
355
356
357
358
359
360
	/** Flag indicating if connection is blocked.  This will be
	    the case before the INIT reply is received, and if there
	    are too many outstading backgrounds requests */
	int blocked;

	/** waitq for blocked connection */
	wait_queue_head_t blocked_waitq;
361
362
363

	/** waitq for reserved requests */
	wait_queue_head_t reserved_req_waitq;
364

365
366
367
	/** The next unique request id */
	u64 reqctr;

368
369
	/** Connection established, cleared on umount, connection
	    abort and device release */
370
	unsigned connected;
Miklos Szeredi's avatar
Miklos Szeredi committed
371

372
373
374
	/** Connection failed (version mismatch).  Cannot race with
	    setting other bitfields since it is only set once in INIT
	    reply, before any other request, and never cleared */
Miklos Szeredi's avatar
Miklos Szeredi committed
375
	unsigned conn_error:1;
376

377
	/** Connection successful.  Only set in INIT */
Miklos Szeredi's avatar
Miklos Szeredi committed
378
	unsigned conn_init:1;
379

380
	/** Do readpages asynchronously?  Only set in INIT */
Miklos Szeredi's avatar
Miklos Szeredi committed
381
	unsigned async_read:1;
382

383
	/** Do not send separate SETATTR request before open(O_TRUNC)  */
Miklos Szeredi's avatar
Miklos Szeredi committed
384
	unsigned atomic_o_trunc:1;
385

386
	/** Filesystem supports NFS exporting.  Only set in INIT */
Miklos Szeredi's avatar
Miklos Szeredi committed
387
	unsigned export_support:1;
388

389
390
391
392
393
	/*
	 * The following bitfields are only for optimization purposes
	 * and hence races in setting them will not cause malfunction
	 */

394
	/** Is fsync not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
395
	unsigned no_fsync:1;
396

397
	/** Is fsyncdir not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
398
	unsigned no_fsyncdir:1;
399

400
	/** Is flush not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
401
	unsigned no_flush:1;
402

403
	/** Is setxattr not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
404
	unsigned no_setxattr:1;
405
406

	/** Is getxattr not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
407
	unsigned no_getxattr:1;
408
409

	/** Is listxattr not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
410
	unsigned no_listxattr:1;
411
412

	/** Is removexattr not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
413
	unsigned no_removexattr:1;
414

415
	/** Are file locking primitives not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
416
	unsigned no_lock:1;
417

Miklos Szeredi's avatar
Miklos Szeredi committed
418
	/** Is access not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
419
	unsigned no_access:1;
Miklos Szeredi's avatar
Miklos Szeredi committed
420

421
	/** Is create not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
422
	unsigned no_create:1;
423

424
	/** Is interrupt not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
425
	unsigned no_interrupt:1;
426

427
	/** Is bmap not implemented by fs? */
Miklos Szeredi's avatar
Miklos Szeredi committed
428
	unsigned no_bmap:1;
429

Tejun Heo's avatar
Tejun Heo committed
430
431
432
	/** Is poll not implemented by fs? */
	unsigned no_poll:1;

433
	/** Do multi-page cached writes */
Miklos Szeredi's avatar
Miklos Szeredi committed
434
	unsigned big_writes:1;
435

436
437
438
	/** The number of requests waiting for completion */
	atomic_t num_waiting;

439
440
441
	/** Negotiated minor version */
	unsigned minor;

Miklos Szeredi's avatar
Miklos Szeredi committed
442
443
	/** Backing dev info */
	struct backing_dev_info bdi;
444

445
446
447
	/** Entry on the fuse_conn_list */
	struct list_head entry;

448
449
	/** Device ID from super block */
	dev_t dev;
450
451
452
453
454
455

	/** Dentries in the control filesystem */
	struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];

	/** number of dentries used in the above array */
	int ctl_ndents;
456
457
458

	/** O_ASYNC requests */
	struct fasync_struct *fasync;
459
460
461

	/** Key for lock owner ID scrambling */
	u32 scramble_key[4];
462
463
464

	/** Reserved request for the DESTROY message */
	struct fuse_req *destroy_req;
465
466
467

	/** Version counter for attribute changes */
	u64 attr_version;
Miklos Szeredi's avatar
Miklos Szeredi committed
468
469
470
471
};

static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
{
472
	return sb->s_fs_info;
Miklos Szeredi's avatar
Miklos Szeredi committed
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
}

static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
{
	return get_fuse_conn_super(inode->i_sb);
}

static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
{
	return container_of(inode, struct fuse_inode, inode);
}

static inline u64 get_node_id(struct inode *inode)
{
	return get_fuse_inode(inode)->nodeid;
}

490
/** Device operations */
491
extern const struct file_operations fuse_dev_operations;
492

Miklos Szeredi's avatar
Miklos Szeredi committed
493
494
extern struct dentry_operations fuse_dentry_operations;

495
496
497
/**
 * Get a filled in inode
 */
Miklos Szeredi's avatar
Miklos Szeredi committed
498
struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
499
500
			int generation, struct fuse_attr *attr,
			u64 attr_valid, u64 attr_version);
501

502
503
504
int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
		     struct fuse_entry_out *outarg, struct inode **inode);

505
506
507
508
/**
 * Send FORGET command
 */
void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
Miklos Szeredi's avatar
Miklos Szeredi committed
509
		      u64 nodeid, u64 nlookup);
510

511
/**
512
 * Initialize READ or READDIR request
513
 */
514
void fuse_read_fill(struct fuse_req *req, struct file *file,
515
		    struct inode *inode, loff_t pos, size_t count, int opcode);
516
517
518
519
520
521

/**
 * Send OPEN or OPENDIR request
 */
int fuse_open_common(struct inode *inode, struct file *file, int isdir);

Tejun Heo's avatar
Tejun Heo committed
522
struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
523
524
525
526
void fuse_file_free(struct fuse_file *ff);
void fuse_finish_open(struct inode *inode, struct file *file,
		      struct fuse_file *ff, struct fuse_open_out *outarg);

527
528
529
/** Fill in ff->reserved_req with a RELEASE request */
void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode);

530
531
532
533
534
/**
 * Send RELEASE or RELEASEDIR request
 */
int fuse_release_common(struct inode *inode, struct file *file, int isdir);

535
536
537
538
539
540
/**
 * Send FSYNC or FSYNCDIR request
 */
int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
		      int isdir);

Tejun Heo's avatar
Tejun Heo committed
541
542
543
544
545
546
/**
 * Notify poll wakeup
 */
int fuse_notify_poll_wakeup(struct fuse_conn *fc,
			    struct fuse_notify_poll_wakeup_out *outarg);

547
/**
Miklos Szeredi's avatar
Miklos Szeredi committed
548
 * Initialize file operations on a regular file
549
550
551
 */
void fuse_init_file_inode(struct inode *inode);

552
/**
Miklos Szeredi's avatar
Miklos Szeredi committed
553
 * Initialize inode operations on regular files and special files
554
555
556
557
 */
void fuse_init_common(struct inode *inode);

/**
Miklos Szeredi's avatar
Miklos Szeredi committed
558
 * Initialize inode and file operations on a directory
559
560
561
562
 */
void fuse_init_dir(struct inode *inode);

/**
Miklos Szeredi's avatar
Miklos Szeredi committed
563
 * Initialize inode operations on a symlink
564
565
566
567
568
569
 */
void fuse_init_symlink(struct inode *inode);

/**
 * Change attributes of an inode
 */
570
571
void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
			    u64 attr_valid, u64 attr_version);
572

Miklos Szeredi's avatar
Miklos Szeredi committed
573
574
575
576
577
void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
				   u64 attr_valid);

void fuse_truncate(struct address_space *mapping, loff_t offset);

578
579
580
581
582
583
584
585
586
587
/**
 * Initialize the client device
 */
int fuse_dev_init(void);

/**
 * Cleanup the client device
 */
void fuse_dev_cleanup(void);

588
589
590
int fuse_ctl_init(void);
void fuse_ctl_cleanup(void);

591
592
593
594
595
/**
 * Allocate a request
 */
struct fuse_req *fuse_request_alloc(void);

Miklos Szeredi's avatar
Miklos Szeredi committed
596
597
struct fuse_req *fuse_request_alloc_nofs(void);

598
599
600
601
602
603
/**
 * Free a request
 */
void fuse_request_free(struct fuse_req *req);

/**
604
 * Get a request, may fail with -ENOMEM
605
 */
606
struct fuse_req *fuse_get_req(struct fuse_conn *fc);
607

608
609
610
611
612
/**
 * Gets a requests for a file operation, always succeeds
 */
struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file);

613
/**
614
615
 * Decrement reference count of a request.  If count goes to zero free
 * the request.
616
617
618
619
 */
void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);

/**
620
 * Send a request (synchronous)
621
 */
622
void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
623
624
625
626

/**
 * Send a request with no reply
 */
627
void fuse_request_send_noreply(struct fuse_conn *fc, struct fuse_req *req);
628
629
630
631

/**
 * Send a request in the background
 */
632
void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
633

634
635
void fuse_request_send_background_locked(struct fuse_conn *fc,
					 struct fuse_req *req);
Miklos Szeredi's avatar
Miklos Szeredi committed
636

637
/* Abort all requests */
638
639
void fuse_abort_conn(struct fuse_conn *fc);

640
641
642
643
/**
 * Invalidate inode attributes
 */
void fuse_invalidate_attr(struct inode *inode);
644

Miklos Szeredi's avatar
Miklos Szeredi committed
645
646
void fuse_invalidate_entry_cache(struct dentry *entry);

647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
/**
 * Acquire reference to fuse_conn
 */
struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);

/**
 * Release reference to fuse_conn
 */
void fuse_conn_put(struct fuse_conn *fc);

/**
 * Add connection to control filesystem
 */
int fuse_ctl_add_conn(struct fuse_conn *fc);

/**
 * Remove connection from control filesystem
 */
void fuse_ctl_remove_conn(struct fuse_conn *fc);
666
667
668
669
670

/**
 * Is file type valid?
 */
int fuse_valid_type(int m);
Miklos Szeredi's avatar
Miklos Szeredi committed
671
672
673
674
675

/**
 * Is task allowed to perform filesystem operation?
 */
int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task);
676
677

u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
Miklos Szeredi's avatar
Miklos Szeredi committed
678
679
680

int fuse_update_attributes(struct inode *inode, struct kstat *stat,
			   struct file *file, bool *refreshed);
Miklos Szeredi's avatar
Miklos Szeredi committed
681
682
683
684
685

void fuse_flush_writepages(struct inode *inode);

void fuse_set_nowrite(struct inode *inode);
void fuse_release_nowrite(struct inode *inode);
686
687

u64 fuse_get_attr_version(struct fuse_conn *fc);
Tejun Heo's avatar
Tejun Heo committed
688
689

#endif /* _FS_FUSE_I_H */