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> | |
11 | #include <linux/wait.h> | |
12 | #include <linux/list.h> | |
13 | #include <linux/spinlock.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/backing-dev.h> | |
16 | #include <asm/semaphore.h> | |
17 | ||
334f485d MS |
18 | /** Max number of pages that can be used in a single read request */ |
19 | #define FUSE_MAX_PAGES_PER_REQ 32 | |
20 | ||
1d3d752b MS |
21 | /** It could be as large as PATH_MAX, but would that have any uses? */ |
22 | #define FUSE_NAME_MAX 1024 | |
23 | ||
1e9a4ed9 MS |
24 | /** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem |
25 | module will check permissions based on the file mode. Otherwise no | |
26 | permission checking is done in the kernel */ | |
27 | #define FUSE_DEFAULT_PERMISSIONS (1 << 0) | |
28 | ||
29 | /** If the FUSE_ALLOW_OTHER flag is given, then not only the user | |
30 | doing the mount will be allowed to access the filesystem */ | |
31 | #define FUSE_ALLOW_OTHER (1 << 1) | |
32 | ||
413ef8cb | 33 | |
d8a5ba45 MS |
34 | /** FUSE inode */ |
35 | struct fuse_inode { | |
36 | /** Inode data */ | |
37 | struct inode inode; | |
38 | ||
39 | /** Unique ID, which identifies the inode between userspace | |
40 | * and kernel */ | |
41 | u64 nodeid; | |
42 | ||
9e6268db MS |
43 | /** Number of lookups on this inode */ |
44 | u64 nlookup; | |
45 | ||
e5e5558e MS |
46 | /** The request used for sending the FORGET message */ |
47 | struct fuse_req *forget_req; | |
48 | ||
d8a5ba45 MS |
49 | /** Time in jiffies until the file attributes are valid */ |
50 | unsigned long i_time; | |
51 | }; | |
52 | ||
b6aeaded MS |
53 | /** FUSE specific file data */ |
54 | struct fuse_file { | |
55 | /** Request reserved for flush and release */ | |
56 | struct fuse_req *release_req; | |
57 | ||
58 | /** File handle used by userspace */ | |
59 | u64 fh; | |
60 | }; | |
61 | ||
334f485d MS |
62 | /** One input argument of a request */ |
63 | struct fuse_in_arg { | |
64 | unsigned size; | |
65 | const void *value; | |
66 | }; | |
67 | ||
68 | /** The request input */ | |
69 | struct fuse_in { | |
70 | /** The request header */ | |
71 | struct fuse_in_header h; | |
72 | ||
73 | /** True if the data for the last argument is in req->pages */ | |
74 | unsigned argpages:1; | |
75 | ||
76 | /** Number of arguments */ | |
77 | unsigned numargs; | |
78 | ||
79 | /** Array of arguments */ | |
80 | struct fuse_in_arg args[3]; | |
81 | }; | |
82 | ||
83 | /** One output argument of a request */ | |
84 | struct fuse_arg { | |
85 | unsigned size; | |
86 | void *value; | |
87 | }; | |
88 | ||
89 | /** The request output */ | |
90 | struct fuse_out { | |
91 | /** Header returned from userspace */ | |
92 | struct fuse_out_header h; | |
93 | ||
095da6cb MS |
94 | /* |
95 | * The following bitfields are not changed during the request | |
96 | * processing | |
97 | */ | |
98 | ||
334f485d MS |
99 | /** Last argument is variable length (can be shorter than |
100 | arg->size) */ | |
101 | unsigned argvar:1; | |
102 | ||
103 | /** Last argument is a list of pages to copy data to */ | |
104 | unsigned argpages:1; | |
105 | ||
106 | /** Zero partially or not copied pages */ | |
107 | unsigned page_zeroing:1; | |
108 | ||
109 | /** Number or arguments */ | |
110 | unsigned numargs; | |
111 | ||
112 | /** Array of arguments */ | |
113 | struct fuse_arg args[3]; | |
114 | }; | |
115 | ||
83cfd493 MS |
116 | /** The request state */ |
117 | enum fuse_req_state { | |
118 | FUSE_REQ_INIT = 0, | |
119 | FUSE_REQ_PENDING, | |
120 | FUSE_REQ_READING, | |
121 | FUSE_REQ_SENT, | |
122 | FUSE_REQ_FINISHED | |
123 | }; | |
124 | ||
64c6d8ed MS |
125 | struct fuse_conn; |
126 | ||
334f485d MS |
127 | /** |
128 | * A request to the client | |
129 | */ | |
130 | struct fuse_req { | |
ce1d5a49 MS |
131 | /** This can be on either pending processing or io lists in |
132 | fuse_conn */ | |
334f485d MS |
133 | struct list_head list; |
134 | ||
1e9a4ed9 MS |
135 | /** Entry on the background list */ |
136 | struct list_head bg_entry; | |
137 | ||
334f485d MS |
138 | /** refcount */ |
139 | atomic_t count; | |
140 | ||
095da6cb MS |
141 | /* |
142 | * The following bitfields are either set once before the | |
143 | * request is queued or setting/clearing them is protected by | |
d7133114 | 144 | * fuse_conn->lock |
095da6cb MS |
145 | */ |
146 | ||
334f485d MS |
147 | /** True if the request has reply */ |
148 | unsigned isreply:1; | |
149 | ||
334f485d MS |
150 | /** The request was interrupted */ |
151 | unsigned interrupted:1; | |
152 | ||
153 | /** Request is sent in the background */ | |
154 | unsigned background:1; | |
155 | ||
156 | /** Data is being copied to/from the request */ | |
157 | unsigned locked:1; | |
158 | ||
83cfd493 MS |
159 | /** State of the request */ |
160 | enum fuse_req_state state; | |
334f485d MS |
161 | |
162 | /** The request input */ | |
163 | struct fuse_in in; | |
164 | ||
165 | /** The request output */ | |
166 | struct fuse_out out; | |
167 | ||
168 | /** Used to wake up the task waiting for completion of request*/ | |
169 | wait_queue_head_t waitq; | |
170 | ||
171 | /** Data for asynchronous requests */ | |
172 | union { | |
e5e5558e | 173 | struct fuse_forget_in forget_in; |
b6aeaded | 174 | struct fuse_release_in release_in; |
3ec870d5 MS |
175 | struct fuse_init_in init_in; |
176 | struct fuse_init_out init_out; | |
361b1eb5 | 177 | struct fuse_read_in read_in; |
334f485d MS |
178 | } misc; |
179 | ||
180 | /** page vector */ | |
181 | struct page *pages[FUSE_MAX_PAGES_PER_REQ]; | |
182 | ||
183 | /** number of pages in vector */ | |
184 | unsigned num_pages; | |
185 | ||
186 | /** offset of data on first page */ | |
187 | unsigned page_offset; | |
188 | ||
189 | /** Inode used in the request */ | |
190 | struct inode *inode; | |
191 | ||
192 | /** Second inode used in the request (or NULL) */ | |
193 | struct inode *inode2; | |
194 | ||
195 | /** File used in the request (or NULL) */ | |
196 | struct file *file; | |
64c6d8ed MS |
197 | |
198 | /** Request completion callback */ | |
199 | void (*end)(struct fuse_conn *, struct fuse_req *); | |
334f485d MS |
200 | }; |
201 | ||
d8a5ba45 MS |
202 | /** |
203 | * A Fuse connection. | |
204 | * | |
205 | * This structure is created, when the filesystem is mounted, and is | |
206 | * destroyed, when the client device is closed and the filesystem is | |
207 | * unmounted. | |
208 | */ | |
209 | struct fuse_conn { | |
d7133114 MS |
210 | /** Lock protecting accessess to members of this structure */ |
211 | spinlock_t lock; | |
212 | ||
d8a5ba45 MS |
213 | /** The user id for this mount */ |
214 | uid_t user_id; | |
215 | ||
87729a55 MS |
216 | /** The group id for this mount */ |
217 | gid_t group_id; | |
218 | ||
1e9a4ed9 MS |
219 | /** The fuse mount flags for this mount */ |
220 | unsigned flags; | |
221 | ||
db50b96c MS |
222 | /** Maximum read size */ |
223 | unsigned max_read; | |
224 | ||
413ef8cb MS |
225 | /** Maximum write size */ |
226 | unsigned max_write; | |
227 | ||
334f485d MS |
228 | /** Readers of the connection are waiting on this */ |
229 | wait_queue_head_t waitq; | |
230 | ||
231 | /** The list of pending requests */ | |
232 | struct list_head pending; | |
233 | ||
234 | /** The list of requests being processed */ | |
235 | struct list_head processing; | |
236 | ||
d77a1d5b MS |
237 | /** The list of requests under I/O */ |
238 | struct list_head io; | |
239 | ||
1e9a4ed9 MS |
240 | /** Requests put in the background (RELEASE or any other |
241 | interrupted request) */ | |
242 | struct list_head background; | |
243 | ||
1e9a4ed9 MS |
244 | /** RW semaphore for exclusion with fuse_put_super() */ |
245 | struct rw_semaphore sbput_sem; | |
246 | ||
334f485d MS |
247 | /** The next unique request id */ |
248 | u64 reqctr; | |
249 | ||
1e9a4ed9 | 250 | /** Mount is active */ |
095da6cb | 251 | unsigned mounted; |
1e9a4ed9 | 252 | |
69a53bf2 MS |
253 | /** Connection established, cleared on umount, connection |
254 | abort and device release */ | |
095da6cb | 255 | unsigned connected; |
1e9a4ed9 | 256 | |
095da6cb MS |
257 | /** Connection failed (version mismatch). Cannot race with |
258 | setting other bitfields since it is only set once in INIT | |
259 | reply, before any other request, and never cleared */ | |
334f485d MS |
260 | unsigned conn_error : 1; |
261 | ||
9cd68455 MS |
262 | /** Do readpages asynchronously? Only set in INIT */ |
263 | unsigned async_read : 1; | |
264 | ||
095da6cb MS |
265 | /* |
266 | * The following bitfields are only for optimization purposes | |
267 | * and hence races in setting them will not cause malfunction | |
268 | */ | |
269 | ||
b6aeaded MS |
270 | /** Is fsync not implemented by fs? */ |
271 | unsigned no_fsync : 1; | |
272 | ||
82547981 MS |
273 | /** Is fsyncdir not implemented by fs? */ |
274 | unsigned no_fsyncdir : 1; | |
275 | ||
b6aeaded MS |
276 | /** Is flush not implemented by fs? */ |
277 | unsigned no_flush : 1; | |
278 | ||
92a8780e MS |
279 | /** Is setxattr not implemented by fs? */ |
280 | unsigned no_setxattr : 1; | |
281 | ||
282 | /** Is getxattr not implemented by fs? */ | |
283 | unsigned no_getxattr : 1; | |
284 | ||
285 | /** Is listxattr not implemented by fs? */ | |
286 | unsigned no_listxattr : 1; | |
287 | ||
288 | /** Is removexattr not implemented by fs? */ | |
289 | unsigned no_removexattr : 1; | |
290 | ||
31d40d74 MS |
291 | /** Is access not implemented by fs? */ |
292 | unsigned no_access : 1; | |
293 | ||
fd72faac MS |
294 | /** Is create not implemented by fs? */ |
295 | unsigned no_create : 1; | |
296 | ||
0cd5b885 MS |
297 | /** The number of requests waiting for completion */ |
298 | atomic_t num_waiting; | |
299 | ||
45714d65 MS |
300 | /** Negotiated minor version */ |
301 | unsigned minor; | |
302 | ||
d8a5ba45 MS |
303 | /** Backing dev info */ |
304 | struct backing_dev_info bdi; | |
f543f253 MS |
305 | |
306 | /** kobject */ | |
307 | struct kobject kobj; | |
385a17bf JD |
308 | |
309 | /** O_ASYNC requests */ | |
310 | struct fasync_struct *fasync; | |
d8a5ba45 MS |
311 | }; |
312 | ||
d8a5ba45 MS |
313 | static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb) |
314 | { | |
6383bdaa | 315 | return sb->s_fs_info; |
d8a5ba45 MS |
316 | } |
317 | ||
318 | static inline struct fuse_conn *get_fuse_conn(struct inode *inode) | |
319 | { | |
320 | return get_fuse_conn_super(inode->i_sb); | |
321 | } | |
322 | ||
f543f253 MS |
323 | static inline struct fuse_conn *get_fuse_conn_kobj(struct kobject *obj) |
324 | { | |
325 | return container_of(obj, struct fuse_conn, kobj); | |
326 | } | |
327 | ||
d8a5ba45 MS |
328 | static inline struct fuse_inode *get_fuse_inode(struct inode *inode) |
329 | { | |
330 | return container_of(inode, struct fuse_inode, inode); | |
331 | } | |
332 | ||
333 | static inline u64 get_node_id(struct inode *inode) | |
334 | { | |
335 | return get_fuse_inode(inode)->nodeid; | |
336 | } | |
337 | ||
334f485d | 338 | /** Device operations */ |
4b6f5d20 | 339 | extern const struct file_operations fuse_dev_operations; |
334f485d | 340 | |
e5e5558e MS |
341 | /** |
342 | * Get a filled in inode | |
343 | */ | |
344 | struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid, | |
9e6268db | 345 | int generation, struct fuse_attr *attr); |
e5e5558e MS |
346 | |
347 | /** | |
348 | * Send FORGET command | |
349 | */ | |
350 | void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, | |
9e6268db | 351 | unsigned long nodeid, u64 nlookup); |
e5e5558e | 352 | |
04730fef | 353 | /** |
361b1eb5 | 354 | * Initialize READ or READDIR request |
04730fef | 355 | */ |
361b1eb5 MS |
356 | void fuse_read_fill(struct fuse_req *req, struct file *file, |
357 | struct inode *inode, loff_t pos, size_t count, int opcode); | |
04730fef MS |
358 | |
359 | /** | |
360 | * Send OPEN or OPENDIR request | |
361 | */ | |
362 | int fuse_open_common(struct inode *inode, struct file *file, int isdir); | |
363 | ||
fd72faac MS |
364 | struct fuse_file *fuse_file_alloc(void); |
365 | void fuse_file_free(struct fuse_file *ff); | |
366 | void fuse_finish_open(struct inode *inode, struct file *file, | |
367 | struct fuse_file *ff, struct fuse_open_out *outarg); | |
368 | ||
369 | /** | |
370 | * Send a RELEASE request | |
371 | */ | |
372 | void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff, | |
373 | u64 nodeid, struct inode *inode, int flags, int isdir); | |
374 | ||
04730fef MS |
375 | /** |
376 | * Send RELEASE or RELEASEDIR request | |
377 | */ | |
378 | int fuse_release_common(struct inode *inode, struct file *file, int isdir); | |
379 | ||
82547981 MS |
380 | /** |
381 | * Send FSYNC or FSYNCDIR request | |
382 | */ | |
383 | int fuse_fsync_common(struct file *file, struct dentry *de, int datasync, | |
384 | int isdir); | |
385 | ||
b6aeaded | 386 | /** |
1779381d | 387 | * Initialize file operations on a regular file |
b6aeaded MS |
388 | */ |
389 | void fuse_init_file_inode(struct inode *inode); | |
390 | ||
e5e5558e | 391 | /** |
1779381d | 392 | * Initialize inode operations on regular files and special files |
e5e5558e MS |
393 | */ |
394 | void fuse_init_common(struct inode *inode); | |
395 | ||
396 | /** | |
1779381d | 397 | * Initialize inode and file operations on a directory |
e5e5558e MS |
398 | */ |
399 | void fuse_init_dir(struct inode *inode); | |
400 | ||
401 | /** | |
1779381d | 402 | * Initialize inode operations on a symlink |
e5e5558e MS |
403 | */ |
404 | void fuse_init_symlink(struct inode *inode); | |
405 | ||
406 | /** | |
407 | * Change attributes of an inode | |
408 | */ | |
409 | void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr); | |
410 | ||
334f485d MS |
411 | /** |
412 | * Initialize the client device | |
413 | */ | |
414 | int fuse_dev_init(void); | |
415 | ||
416 | /** | |
417 | * Cleanup the client device | |
418 | */ | |
419 | void fuse_dev_cleanup(void); | |
420 | ||
421 | /** | |
422 | * Allocate a request | |
423 | */ | |
424 | struct fuse_req *fuse_request_alloc(void); | |
425 | ||
426 | /** | |
427 | * Free a request | |
428 | */ | |
429 | void fuse_request_free(struct fuse_req *req); | |
430 | ||
431 | /** | |
432 | * Reinitialize a request, the preallocated flag is left unmodified | |
433 | */ | |
434 | void fuse_reset_request(struct fuse_req *req); | |
435 | ||
436 | /** | |
437 | * Reserve a preallocated request | |
438 | */ | |
ce1d5a49 | 439 | struct fuse_req *fuse_get_req(struct fuse_conn *fc); |
334f485d | 440 | |
334f485d | 441 | /** |
ce1d5a49 MS |
442 | * Decrement reference count of a request. If count goes to zero free |
443 | * the request. | |
334f485d MS |
444 | */ |
445 | void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req); | |
446 | ||
447 | /** | |
7c352bdf | 448 | * Send a request (synchronous) |
334f485d MS |
449 | */ |
450 | void request_send(struct fuse_conn *fc, struct fuse_req *req); | |
451 | ||
334f485d MS |
452 | /** |
453 | * Send a request with no reply | |
454 | */ | |
455 | void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req); | |
456 | ||
457 | /** | |
458 | * Send a request in the background | |
459 | */ | |
460 | void request_send_background(struct fuse_conn *fc, struct fuse_req *req); | |
461 | ||
1e9a4ed9 | 462 | /** |
1779381d | 463 | * Release inodes and file associated with background request |
1e9a4ed9 | 464 | */ |
d7133114 | 465 | void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req); |
1e9a4ed9 | 466 | |
69a53bf2 MS |
467 | /* Abort all requests */ |
468 | void fuse_abort_conn(struct fuse_conn *fc); | |
469 | ||
e5e5558e MS |
470 | /** |
471 | * Get the attributes of a file | |
472 | */ | |
473 | int fuse_do_getattr(struct inode *inode); | |
474 | ||
475 | /** | |
476 | * Invalidate inode attributes | |
477 | */ | |
478 | void fuse_invalidate_attr(struct inode *inode); |