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