Commit | Line | Data |
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d8a5ba45 MS |
1 | /* |
2 | FUSE: Filesystem in Userspace | |
d7133114 | 3 | Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu> |
d8a5ba45 MS |
4 | |
5 | This program can be distributed under the terms of the GNU GPL. | |
6 | See the file COPYING. | |
7 | */ | |
8 | ||
9 | #include <linux/fuse.h> | |
10 | #include <linux/fs.h> | |
51eb01e7 | 11 | #include <linux/mount.h> |
d8a5ba45 MS |
12 | #include <linux/wait.h> |
13 | #include <linux/list.h> | |
14 | #include <linux/spinlock.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/backing-dev.h> | |
bafa9654 | 17 | #include <linux/mutex.h> |
d8a5ba45 | 18 | |
334f485d MS |
19 | /** Max number of pages that can be used in a single read request */ |
20 | #define FUSE_MAX_PAGES_PER_REQ 32 | |
21 | ||
08a53cdc | 22 | /** Maximum number of outstanding background requests */ |
f92b99b9 MS |
23 | #define FUSE_MAX_BACKGROUND 12 |
24 | ||
25 | /** Congestion starts at 75% of maximum */ | |
26 | #define FUSE_CONGESTION_THRESHOLD (FUSE_MAX_BACKGROUND * 75 / 100) | |
08a53cdc | 27 | |
1d3d752b MS |
28 | /** It could be as large as PATH_MAX, but would that have any uses? */ |
29 | #define FUSE_NAME_MAX 1024 | |
30 | ||
bafa9654 MS |
31 | /** Number of dentries for each connection in the control filesystem */ |
32 | #define FUSE_CTL_NUM_DENTRIES 3 | |
33 | ||
1e9a4ed9 MS |
34 | /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem |
35 | module will check permissions based on the file mode. Otherwise no | |
36 | permission checking is done in the kernel */ | |
37 | #define FUSE_DEFAULT_PERMISSIONS (1 << 0) | |
38 | ||
39 | /** If the FUSE_ALLOW_OTHER flag is given, then not only the user | |
40 | doing the mount will be allowed to access the filesystem */ | |
41 | #define FUSE_ALLOW_OTHER (1 << 1) | |
42 | ||
bafa9654 MS |
43 | /** List of active connections */ |
44 | extern struct list_head fuse_conn_list; | |
45 | ||
46 | /** Global mutex protecting fuse_conn_list and the control filesystem */ | |
47 | extern struct mutex fuse_mutex; | |
413ef8cb | 48 | |
d8a5ba45 MS |
49 | /** FUSE inode */ |
50 | struct fuse_inode { | |
51 | /** Inode data */ | |
52 | struct inode inode; | |
53 | ||
54 | /** Unique ID, which identifies the inode between userspace | |
55 | * and kernel */ | |
56 | u64 nodeid; | |
57 | ||
9e6268db MS |
58 | /** Number of lookups on this inode */ |
59 | u64 nlookup; | |
60 | ||
e5e5558e MS |
61 | /** The request used for sending the FORGET message */ |
62 | struct fuse_req *forget_req; | |
63 | ||
d8a5ba45 | 64 | /** Time in jiffies until the file attributes are valid */ |
0a0898cf | 65 | u64 i_time; |
ebc14c4d MS |
66 | |
67 | /** The sticky bit in inode->i_mode may have been removed, so | |
68 | preserve the original mode */ | |
69 | mode_t orig_i_mode; | |
1fb69e78 MS |
70 | |
71 | /** Version of last attribute change */ | |
72 | u64 attr_version; | |
d8a5ba45 MS |
73 | }; |
74 | ||
b6aeaded MS |
75 | /** FUSE specific file data */ |
76 | struct fuse_file { | |
77 | /** Request reserved for flush and release */ | |
33649c91 | 78 | struct fuse_req *reserved_req; |
b6aeaded MS |
79 | |
80 | /** File handle used by userspace */ | |
81 | u64 fh; | |
c756e0a4 MS |
82 | |
83 | /** Refcount */ | |
84 | atomic_t count; | |
b6aeaded MS |
85 | }; |
86 | ||
334f485d MS |
87 | /** One input argument of a request */ |
88 | struct fuse_in_arg { | |
89 | unsigned size; | |
90 | const void *value; | |
91 | }; | |
92 | ||
93 | /** The request input */ | |
94 | struct fuse_in { | |
95 | /** The request header */ | |
96 | struct fuse_in_header h; | |
97 | ||
98 | /** True if the data for the last argument is in req->pages */ | |
99 | unsigned argpages:1; | |
100 | ||
101 | /** Number of arguments */ | |
102 | unsigned numargs; | |
103 | ||
104 | /** Array of arguments */ | |
105 | struct fuse_in_arg args[3]; | |
106 | }; | |
107 | ||
108 | /** One output argument of a request */ | |
109 | struct fuse_arg { | |
110 | unsigned size; | |
111 | void *value; | |
112 | }; | |
113 | ||
114 | /** The request output */ | |
115 | struct fuse_out { | |
116 | /** Header returned from userspace */ | |
117 | struct fuse_out_header h; | |
118 | ||
095da6cb MS |
119 | /* |
120 | * The following bitfields are not changed during the request | |
121 | * processing | |
122 | */ | |
123 | ||
334f485d MS |
124 | /** Last argument is variable length (can be shorter than |
125 | arg->size) */ | |
126 | unsigned argvar:1; | |
127 | ||
128 | /** Last argument is a list of pages to copy data to */ | |
129 | unsigned argpages:1; | |
130 | ||
131 | /** Zero partially or not copied pages */ | |
132 | unsigned page_zeroing:1; | |
133 | ||
134 | /** Number or arguments */ | |
135 | unsigned numargs; | |
136 | ||
137 | /** Array of arguments */ | |
138 | struct fuse_arg args[3]; | |
139 | }; | |
140 | ||
83cfd493 MS |
141 | /** The request state */ |
142 | enum fuse_req_state { | |
143 | FUSE_REQ_INIT = 0, | |
144 | FUSE_REQ_PENDING, | |
145 | FUSE_REQ_READING, | |
146 | FUSE_REQ_SENT, | |
a4d27e75 | 147 | FUSE_REQ_WRITING, |
83cfd493 MS |
148 | FUSE_REQ_FINISHED |
149 | }; | |
150 | ||
64c6d8ed MS |
151 | struct fuse_conn; |
152 | ||
334f485d MS |
153 | /** |
154 | * A request to the client | |
155 | */ | |
156 | struct fuse_req { | |
ce1d5a49 MS |
157 | /** This can be on either pending processing or io lists in |
158 | fuse_conn */ | |
334f485d MS |
159 | struct list_head list; |
160 | ||
a4d27e75 MS |
161 | /** Entry on the interrupts list */ |
162 | struct list_head intr_entry; | |
163 | ||
334f485d MS |
164 | /** refcount */ |
165 | atomic_t count; | |
166 | ||
a4d27e75 MS |
167 | /** Unique ID for the interrupt request */ |
168 | u64 intr_unique; | |
169 | ||
095da6cb MS |
170 | /* |
171 | * The following bitfields are either set once before the | |
172 | * request is queued or setting/clearing them is protected by | |
d7133114 | 173 | * fuse_conn->lock |
095da6cb MS |
174 | */ |
175 | ||
334f485d MS |
176 | /** True if the request has reply */ |
177 | unsigned isreply:1; | |
178 | ||
51eb01e7 MS |
179 | /** Force sending of the request even if interrupted */ |
180 | unsigned force:1; | |
181 | ||
f9a2842e MS |
182 | /** The request was aborted */ |
183 | unsigned aborted:1; | |
334f485d MS |
184 | |
185 | /** Request is sent in the background */ | |
186 | unsigned background:1; | |
187 | ||
a4d27e75 MS |
188 | /** The request has been interrupted */ |
189 | unsigned interrupted:1; | |
190 | ||
334f485d MS |
191 | /** Data is being copied to/from the request */ |
192 | unsigned locked:1; | |
193 | ||
9bc5ddda MS |
194 | /** Request is counted as "waiting" */ |
195 | unsigned waiting:1; | |
196 | ||
83cfd493 MS |
197 | /** State of the request */ |
198 | enum fuse_req_state state; | |
334f485d MS |
199 | |
200 | /** The request input */ | |
201 | struct fuse_in in; | |
202 | ||
203 | /** The request output */ | |
204 | struct fuse_out out; | |
205 | ||
206 | /** Used to wake up the task waiting for completion of request*/ | |
207 | wait_queue_head_t waitq; | |
208 | ||
209 | /** Data for asynchronous requests */ | |
210 | union { | |
e5e5558e | 211 | struct fuse_forget_in forget_in; |
b6aeaded | 212 | struct fuse_release_in release_in; |
3ec870d5 MS |
213 | struct fuse_init_in init_in; |
214 | struct fuse_init_out init_out; | |
361b1eb5 | 215 | struct fuse_read_in read_in; |
71421259 | 216 | struct fuse_lk_in lk_in; |
334f485d MS |
217 | } misc; |
218 | ||
219 | /** page vector */ | |
220 | struct page *pages[FUSE_MAX_PAGES_PER_REQ]; | |
221 | ||
222 | /** number of pages in vector */ | |
223 | unsigned num_pages; | |
224 | ||
225 | /** offset of data on first page */ | |
226 | unsigned page_offset; | |
227 | ||
334f485d | 228 | /** File used in the request (or NULL) */ |
c756e0a4 | 229 | struct fuse_file *ff; |
64c6d8ed | 230 | |
51eb01e7 MS |
231 | /** vfsmount used in release */ |
232 | struct vfsmount *vfsmount; | |
233 | ||
234 | /** dentry used in release */ | |
235 | struct dentry *dentry; | |
236 | ||
64c6d8ed MS |
237 | /** Request completion callback */ |
238 | void (*end)(struct fuse_conn *, struct fuse_req *); | |
33649c91 MS |
239 | |
240 | /** Request is stolen from fuse_file->reserved_req */ | |
241 | struct file *stolen_file; | |
334f485d MS |
242 | }; |
243 | ||
d8a5ba45 MS |
244 | /** |
245 | * A Fuse connection. | |
246 | * | |
247 | * This structure is created, when the filesystem is mounted, and is | |
248 | * destroyed, when the client device is closed and the filesystem is | |
249 | * unmounted. | |
250 | */ | |
251 | struct fuse_conn { | |
d7133114 MS |
252 | /** Lock protecting accessess to members of this structure */ |
253 | spinlock_t lock; | |
254 | ||
d2a85164 MS |
255 | /** Mutex protecting against directory alias creation */ |
256 | struct mutex inst_mutex; | |
257 | ||
bafa9654 MS |
258 | /** Refcount */ |
259 | atomic_t count; | |
260 | ||
d8a5ba45 MS |
261 | /** The user id for this mount */ |
262 | uid_t user_id; | |
263 | ||
87729a55 MS |
264 | /** The group id for this mount */ |
265 | gid_t group_id; | |
266 | ||
1e9a4ed9 MS |
267 | /** The fuse mount flags for this mount */ |
268 | unsigned flags; | |
269 | ||
db50b96c MS |
270 | /** Maximum read size */ |
271 | unsigned max_read; | |
272 | ||
413ef8cb MS |
273 | /** Maximum write size */ |
274 | unsigned max_write; | |
275 | ||
334f485d MS |
276 | /** Readers of the connection are waiting on this */ |
277 | wait_queue_head_t waitq; | |
278 | ||
279 | /** The list of pending requests */ | |
280 | struct list_head pending; | |
281 | ||
282 | /** The list of requests being processed */ | |
283 | struct list_head processing; | |
284 | ||
d77a1d5b MS |
285 | /** The list of requests under I/O */ |
286 | struct list_head io; | |
287 | ||
08a53cdc MS |
288 | /** Number of requests currently in the background */ |
289 | unsigned num_background; | |
290 | ||
a4d27e75 MS |
291 | /** Pending interrupts */ |
292 | struct list_head interrupts; | |
293 | ||
08a53cdc MS |
294 | /** Flag indicating if connection is blocked. This will be |
295 | the case before the INIT reply is received, and if there | |
296 | are too many outstading backgrounds requests */ | |
297 | int blocked; | |
298 | ||
299 | /** waitq for blocked connection */ | |
300 | wait_queue_head_t blocked_waitq; | |
de5e3dec MS |
301 | |
302 | /** waitq for reserved requests */ | |
303 | wait_queue_head_t reserved_req_waitq; | |
08a53cdc | 304 | |
334f485d MS |
305 | /** The next unique request id */ |
306 | u64 reqctr; | |
307 | ||
69a53bf2 MS |
308 | /** Connection established, cleared on umount, connection |
309 | abort and device release */ | |
095da6cb | 310 | unsigned connected; |
1e9a4ed9 | 311 | |
095da6cb MS |
312 | /** Connection failed (version mismatch). Cannot race with |
313 | setting other bitfields since it is only set once in INIT | |
314 | reply, before any other request, and never cleared */ | |
334f485d MS |
315 | unsigned conn_error : 1; |
316 | ||
0ec7ca41 MS |
317 | /** Connection successful. Only set in INIT */ |
318 | unsigned conn_init : 1; | |
319 | ||
9cd68455 MS |
320 | /** Do readpages asynchronously? Only set in INIT */ |
321 | unsigned async_read : 1; | |
322 | ||
6ff958ed MS |
323 | /** Do not send separate SETATTR request before open(O_TRUNC) */ |
324 | unsigned atomic_o_trunc : 1; | |
325 | ||
095da6cb MS |
326 | /* |
327 | * The following bitfields are only for optimization purposes | |
328 | * and hence races in setting them will not cause malfunction | |
329 | */ | |
330 | ||
b6aeaded MS |
331 | /** Is fsync not implemented by fs? */ |
332 | unsigned no_fsync : 1; | |
333 | ||
82547981 MS |
334 | /** Is fsyncdir not implemented by fs? */ |
335 | unsigned no_fsyncdir : 1; | |
336 | ||
b6aeaded MS |
337 | /** Is flush not implemented by fs? */ |
338 | unsigned no_flush : 1; | |
339 | ||
92a8780e MS |
340 | /** Is setxattr not implemented by fs? */ |
341 | unsigned no_setxattr : 1; | |
342 | ||
343 | /** Is getxattr not implemented by fs? */ | |
344 | unsigned no_getxattr : 1; | |
345 | ||
346 | /** Is listxattr not implemented by fs? */ | |
347 | unsigned no_listxattr : 1; | |
348 | ||
349 | /** Is removexattr not implemented by fs? */ | |
350 | unsigned no_removexattr : 1; | |
351 | ||
71421259 MS |
352 | /** Are file locking primitives not implemented by fs? */ |
353 | unsigned no_lock : 1; | |
354 | ||
31d40d74 MS |
355 | /** Is access not implemented by fs? */ |
356 | unsigned no_access : 1; | |
357 | ||
fd72faac MS |
358 | /** Is create not implemented by fs? */ |
359 | unsigned no_create : 1; | |
360 | ||
a4d27e75 MS |
361 | /** Is interrupt not implemented by fs? */ |
362 | unsigned no_interrupt : 1; | |
363 | ||
b2d2272f MS |
364 | /** Is bmap not implemented by fs? */ |
365 | unsigned no_bmap : 1; | |
366 | ||
0cd5b885 MS |
367 | /** The number of requests waiting for completion */ |
368 | atomic_t num_waiting; | |
369 | ||
45714d65 MS |
370 | /** Negotiated minor version */ |
371 | unsigned minor; | |
372 | ||
d8a5ba45 MS |
373 | /** Backing dev info */ |
374 | struct backing_dev_info bdi; | |
f543f253 | 375 | |
bafa9654 MS |
376 | /** Entry on the fuse_conn_list */ |
377 | struct list_head entry; | |
378 | ||
379 | /** Unique ID */ | |
380 | u64 id; | |
381 | ||
382 | /** Dentries in the control filesystem */ | |
383 | struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES]; | |
384 | ||
385 | /** number of dentries used in the above array */ | |
386 | int ctl_ndents; | |
385a17bf JD |
387 | |
388 | /** O_ASYNC requests */ | |
389 | struct fasync_struct *fasync; | |
9c8ef561 MS |
390 | |
391 | /** Key for lock owner ID scrambling */ | |
392 | u32 scramble_key[4]; | |
0ec7ca41 MS |
393 | |
394 | /** Reserved request for the DESTROY message */ | |
395 | struct fuse_req *destroy_req; | |
1fb69e78 MS |
396 | |
397 | /** Version counter for attribute changes */ | |
398 | u64 attr_version; | |
d8a5ba45 MS |
399 | }; |
400 | ||
d8a5ba45 MS |
401 | static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb) |
402 | { | |
6383bdaa | 403 | return sb->s_fs_info; |
d8a5ba45 MS |
404 | } |
405 | ||
406 | static inline struct fuse_conn *get_fuse_conn(struct inode *inode) | |
407 | { | |
408 | return get_fuse_conn_super(inode->i_sb); | |
409 | } | |
410 | ||
411 | static inline struct fuse_inode *get_fuse_inode(struct inode *inode) | |
412 | { | |
413 | return container_of(inode, struct fuse_inode, inode); | |
414 | } | |
415 | ||
416 | static inline u64 get_node_id(struct inode *inode) | |
417 | { | |
418 | return get_fuse_inode(inode)->nodeid; | |
419 | } | |
420 | ||
334f485d | 421 | /** Device operations */ |
4b6f5d20 | 422 | extern const struct file_operations fuse_dev_operations; |
334f485d | 423 | |
e5e5558e MS |
424 | /** |
425 | * Get a filled in inode | |
426 | */ | |
427 | struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid, | |
1fb69e78 MS |
428 | int generation, struct fuse_attr *attr, |
429 | u64 attr_valid, u64 attr_version); | |
e5e5558e MS |
430 | |
431 | /** | |
432 | * Send FORGET command | |
433 | */ | |
434 | void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, | |
9e6268db | 435 | unsigned long nodeid, u64 nlookup); |
e5e5558e | 436 | |
04730fef | 437 | /** |
361b1eb5 | 438 | * Initialize READ or READDIR request |
04730fef | 439 | */ |
c756e0a4 | 440 | void fuse_read_fill(struct fuse_req *req, struct fuse_file *ff, |
361b1eb5 | 441 | struct inode *inode, loff_t pos, size_t count, int opcode); |
04730fef MS |
442 | |
443 | /** | |
444 | * Send OPEN or OPENDIR request | |
445 | */ | |
446 | int fuse_open_common(struct inode *inode, struct file *file, int isdir); | |
447 | ||
fd72faac MS |
448 | struct fuse_file *fuse_file_alloc(void); |
449 | void fuse_file_free(struct fuse_file *ff); | |
450 | void fuse_finish_open(struct inode *inode, struct file *file, | |
451 | struct fuse_file *ff, struct fuse_open_out *outarg); | |
452 | ||
c756e0a4 MS |
453 | /** Fill in ff->reserved_req with a RELEASE request */ |
454 | void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode); | |
455 | ||
04730fef MS |
456 | /** |
457 | * Send RELEASE or RELEASEDIR request | |
458 | */ | |
459 | int fuse_release_common(struct inode *inode, struct file *file, int isdir); | |
460 | ||
82547981 MS |
461 | /** |
462 | * Send FSYNC or FSYNCDIR request | |
463 | */ | |
464 | int fuse_fsync_common(struct file *file, struct dentry *de, int datasync, | |
465 | int isdir); | |
466 | ||
b6aeaded | 467 | /** |
1779381d | 468 | * Initialize file operations on a regular file |
b6aeaded MS |
469 | */ |
470 | void fuse_init_file_inode(struct inode *inode); | |
471 | ||
e5e5558e | 472 | /** |
1779381d | 473 | * Initialize inode operations on regular files and special files |
e5e5558e MS |
474 | */ |
475 | void fuse_init_common(struct inode *inode); | |
476 | ||
477 | /** | |
1779381d | 478 | * Initialize inode and file operations on a directory |
e5e5558e MS |
479 | */ |
480 | void fuse_init_dir(struct inode *inode); | |
481 | ||
482 | /** | |
1779381d | 483 | * Initialize inode operations on a symlink |
e5e5558e MS |
484 | */ |
485 | void fuse_init_symlink(struct inode *inode); | |
486 | ||
487 | /** | |
488 | * Change attributes of an inode | |
489 | */ | |
1fb69e78 MS |
490 | void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, |
491 | u64 attr_valid, u64 attr_version); | |
e5e5558e | 492 | |
334f485d MS |
493 | /** |
494 | * Initialize the client device | |
495 | */ | |
496 | int fuse_dev_init(void); | |
497 | ||
498 | /** | |
499 | * Cleanup the client device | |
500 | */ | |
501 | void fuse_dev_cleanup(void); | |
502 | ||
bafa9654 MS |
503 | int fuse_ctl_init(void); |
504 | void fuse_ctl_cleanup(void); | |
505 | ||
334f485d MS |
506 | /** |
507 | * Allocate a request | |
508 | */ | |
509 | struct fuse_req *fuse_request_alloc(void); | |
510 | ||
511 | /** | |
512 | * Free a request | |
513 | */ | |
514 | void fuse_request_free(struct fuse_req *req); | |
515 | ||
334f485d | 516 | /** |
33649c91 | 517 | * Get a request, may fail with -ENOMEM |
334f485d | 518 | */ |
ce1d5a49 | 519 | struct fuse_req *fuse_get_req(struct fuse_conn *fc); |
334f485d | 520 | |
33649c91 MS |
521 | /** |
522 | * Gets a requests for a file operation, always succeeds | |
523 | */ | |
524 | struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file); | |
525 | ||
334f485d | 526 | /** |
ce1d5a49 MS |
527 | * Decrement reference count of a request. If count goes to zero free |
528 | * the request. | |
334f485d MS |
529 | */ |
530 | void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req); | |
531 | ||
532 | /** | |
7c352bdf | 533 | * Send a request (synchronous) |
334f485d MS |
534 | */ |
535 | void request_send(struct fuse_conn *fc, struct fuse_req *req); | |
536 | ||
334f485d MS |
537 | /** |
538 | * Send a request with no reply | |
539 | */ | |
540 | void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req); | |
541 | ||
542 | /** | |
543 | * Send a request in the background | |
544 | */ | |
545 | void request_send_background(struct fuse_conn *fc, struct fuse_req *req); | |
546 | ||
5a5fb1ea | 547 | /* Abort all requests */ |
69a53bf2 MS |
548 | void fuse_abort_conn(struct fuse_conn *fc); |
549 | ||
e5e5558e MS |
550 | /** |
551 | * Invalidate inode attributes | |
552 | */ | |
553 | void fuse_invalidate_attr(struct inode *inode); | |
bafa9654 MS |
554 | |
555 | /** | |
556 | * Acquire reference to fuse_conn | |
557 | */ | |
558 | struct fuse_conn *fuse_conn_get(struct fuse_conn *fc); | |
559 | ||
560 | /** | |
561 | * Release reference to fuse_conn | |
562 | */ | |
563 | void fuse_conn_put(struct fuse_conn *fc); | |
564 | ||
565 | /** | |
566 | * Add connection to control filesystem | |
567 | */ | |
568 | int fuse_ctl_add_conn(struct fuse_conn *fc); | |
569 | ||
570 | /** | |
571 | * Remove connection from control filesystem | |
572 | */ | |
573 | void fuse_ctl_remove_conn(struct fuse_conn *fc); | |
a5bfffac TS |
574 | |
575 | /** | |
576 | * Is file type valid? | |
577 | */ | |
578 | int fuse_valid_type(int m); | |
e57ac683 MS |
579 | |
580 | /** | |
581 | * Is task allowed to perform filesystem operation? | |
582 | */ | |
583 | int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task); |