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Miklos Szeredid8a5ba42005-09-09 13:10:26 -07001/*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2005 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#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
Miklos Szeredi334f4852005-09-09 13:10:27 -070018/** Max number of pages that can be used in a single read request */
19#define FUSE_MAX_PAGES_PER_REQ 32
20
21/** If more requests are outstanding, then the operation will block */
22#define FUSE_MAX_OUTSTANDING 10
23
Miklos Szeredi1d3d7522006-01-06 00:19:40 -080024/** It could be as large as PATH_MAX, but would that have any uses? */
25#define FUSE_NAME_MAX 1024
26
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -070027/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
28 module will check permissions based on the file mode. Otherwise no
29 permission checking is done in the kernel */
30#define FUSE_DEFAULT_PERMISSIONS (1 << 0)
31
32/** If the FUSE_ALLOW_OTHER flag is given, then not only the user
33 doing the mount will be allowed to access the filesystem */
34#define FUSE_ALLOW_OTHER (1 << 1)
35
Miklos Szeredi413ef8c2005-09-09 13:10:35 -070036
Miklos Szeredid8a5ba42005-09-09 13:10:26 -070037/** FUSE inode */
38struct fuse_inode {
39 /** Inode data */
40 struct inode inode;
41
42 /** Unique ID, which identifies the inode between userspace
43 * and kernel */
44 u64 nodeid;
45
Miklos Szeredi9e6268d2005-09-09 13:10:29 -070046 /** Number of lookups on this inode */
47 u64 nlookup;
48
Miklos Szeredie5e55582005-09-09 13:10:28 -070049 /** The request used for sending the FORGET message */
50 struct fuse_req *forget_req;
51
Miklos Szeredid8a5ba42005-09-09 13:10:26 -070052 /** Time in jiffies until the file attributes are valid */
53 unsigned long i_time;
54};
55
Miklos Szeredib6aeade2005-09-09 13:10:30 -070056/** FUSE specific file data */
57struct fuse_file {
58 /** Request reserved for flush and release */
59 struct fuse_req *release_req;
60
61 /** File handle used by userspace */
62 u64 fh;
63};
64
Miklos Szeredi334f4852005-09-09 13:10:27 -070065/** One input argument of a request */
66struct fuse_in_arg {
67 unsigned size;
68 const void *value;
69};
70
71/** The request input */
72struct fuse_in {
73 /** The request header */
74 struct fuse_in_header h;
75
76 /** True if the data for the last argument is in req->pages */
77 unsigned argpages:1;
78
79 /** Number of arguments */
80 unsigned numargs;
81
82 /** Array of arguments */
83 struct fuse_in_arg args[3];
84};
85
86/** One output argument of a request */
87struct fuse_arg {
88 unsigned size;
89 void *value;
90};
91
92/** The request output */
93struct fuse_out {
94 /** Header returned from userspace */
95 struct fuse_out_header h;
96
Miklos Szeredi095da6c2006-01-16 22:14:52 -080097 /*
98 * The following bitfields are not changed during the request
99 * processing
100 */
101
Miklos Szeredi334f4852005-09-09 13:10:27 -0700102 /** Last argument is variable length (can be shorter than
103 arg->size) */
104 unsigned argvar:1;
105
106 /** Last argument is a list of pages to copy data to */
107 unsigned argpages:1;
108
109 /** Zero partially or not copied pages */
110 unsigned page_zeroing:1;
111
112 /** Number or arguments */
113 unsigned numargs;
114
115 /** Array of arguments */
116 struct fuse_arg args[3];
117};
118
Miklos Szeredi83cfd492006-01-16 22:14:31 -0800119/** The request state */
120enum fuse_req_state {
121 FUSE_REQ_INIT = 0,
122 FUSE_REQ_PENDING,
123 FUSE_REQ_READING,
124 FUSE_REQ_SENT,
125 FUSE_REQ_FINISHED
126};
127
Miklos Szeredi64c6d8e2006-01-16 22:14:42 -0800128struct fuse_conn;
129
Miklos Szeredi334f4852005-09-09 13:10:27 -0700130/**
131 * A request to the client
132 */
133struct fuse_req {
Miklos Szeredid77a1d52006-01-16 22:14:31 -0800134 /** This can be on either unused_list, pending processing or
135 io lists in fuse_conn */
Miklos Szeredi334f4852005-09-09 13:10:27 -0700136 struct list_head list;
137
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700138 /** Entry on the background list */
139 struct list_head bg_entry;
140
Miklos Szeredi334f4852005-09-09 13:10:27 -0700141 /** refcount */
142 atomic_t count;
143
Miklos Szeredi095da6c2006-01-16 22:14:52 -0800144 /*
145 * The following bitfields are either set once before the
146 * request is queued or setting/clearing them is protected by
147 * fuse_lock
148 */
149
Miklos Szeredi334f4852005-09-09 13:10:27 -0700150 /** True if the request has reply */
151 unsigned isreply:1;
152
153 /** The request is preallocated */
154 unsigned preallocated:1;
155
156 /** The request was interrupted */
157 unsigned interrupted:1;
158
159 /** Request is sent in the background */
160 unsigned background:1;
161
162 /** Data is being copied to/from the request */
163 unsigned locked:1;
164
Miklos Szeredi83cfd492006-01-16 22:14:31 -0800165 /** State of the request */
166 enum fuse_req_state state;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700167
168 /** The request input */
169 struct fuse_in in;
170
171 /** The request output */
172 struct fuse_out out;
173
174 /** Used to wake up the task waiting for completion of request*/
175 wait_queue_head_t waitq;
176
177 /** Data for asynchronous requests */
178 union {
Miklos Szeredie5e55582005-09-09 13:10:28 -0700179 struct fuse_forget_in forget_in;
Miklos Szeredib6aeade2005-09-09 13:10:30 -0700180 struct fuse_release_in release_in;
Miklos Szeredi3ec870d2006-01-06 00:19:41 -0800181 struct fuse_init_in init_in;
182 struct fuse_init_out init_out;
Miklos Szeredi361b1eb52006-01-16 22:14:45 -0800183 struct fuse_read_in read_in;
Miklos Szeredi334f4852005-09-09 13:10:27 -0700184 } misc;
185
186 /** page vector */
187 struct page *pages[FUSE_MAX_PAGES_PER_REQ];
188
189 /** number of pages in vector */
190 unsigned num_pages;
191
192 /** offset of data on first page */
193 unsigned page_offset;
194
195 /** Inode used in the request */
196 struct inode *inode;
197
198 /** Second inode used in the request (or NULL) */
199 struct inode *inode2;
200
201 /** File used in the request (or NULL) */
202 struct file *file;
Miklos Szeredi64c6d8e2006-01-16 22:14:42 -0800203
204 /** Request completion callback */
205 void (*end)(struct fuse_conn *, struct fuse_req *);
Miklos Szeredi334f4852005-09-09 13:10:27 -0700206};
207
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700208/**
209 * A Fuse connection.
210 *
211 * This structure is created, when the filesystem is mounted, and is
212 * destroyed, when the client device is closed and the filesystem is
213 * unmounted.
214 */
215struct fuse_conn {
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700216 /** The user id for this mount */
217 uid_t user_id;
218
Miklos Szeredi87729a52005-09-09 13:10:34 -0700219 /** The group id for this mount */
220 gid_t group_id;
221
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700222 /** The fuse mount flags for this mount */
223 unsigned flags;
224
Miklos Szeredidb50b962005-09-09 13:10:33 -0700225 /** Maximum read size */
226 unsigned max_read;
227
Miklos Szeredi413ef8c2005-09-09 13:10:35 -0700228 /** Maximum write size */
229 unsigned max_write;
230
Miklos Szeredi334f4852005-09-09 13:10:27 -0700231 /** Readers of the connection are waiting on this */
232 wait_queue_head_t waitq;
233
234 /** The list of pending requests */
235 struct list_head pending;
236
237 /** The list of requests being processed */
238 struct list_head processing;
239
Miklos Szeredid77a1d52006-01-16 22:14:31 -0800240 /** The list of requests under I/O */
241 struct list_head io;
242
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700243 /** Requests put in the background (RELEASE or any other
244 interrupted request) */
245 struct list_head background;
246
Miklos Szeredi334f4852005-09-09 13:10:27 -0700247 /** Controls the maximum number of outstanding requests */
248 struct semaphore outstanding_sem;
249
250 /** This counts the number of outstanding requests if
251 outstanding_sem would go negative */
252 unsigned outstanding_debt;
253
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700254 /** RW semaphore for exclusion with fuse_put_super() */
255 struct rw_semaphore sbput_sem;
256
Miklos Szeredi334f4852005-09-09 13:10:27 -0700257 /** The list of unused requests */
258 struct list_head unused_list;
259
260 /** The next unique request id */
261 u64 reqctr;
262
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700263 /** Mount is active */
Miklos Szeredi095da6c2006-01-16 22:14:52 -0800264 unsigned mounted;
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700265
Miklos Szeredi69a53bf2006-01-16 22:14:41 -0800266 /** Connection established, cleared on umount, connection
267 abort and device release */
Miklos Szeredi095da6c2006-01-16 22:14:52 -0800268 unsigned connected;
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700269
Miklos Szeredi095da6c2006-01-16 22:14:52 -0800270 /** Connection failed (version mismatch). Cannot race with
271 setting other bitfields since it is only set once in INIT
272 reply, before any other request, and never cleared */
Miklos Szeredi334f4852005-09-09 13:10:27 -0700273 unsigned conn_error : 1;
274
Miklos Szeredi9cd68452006-02-01 03:04:40 -0800275 /** Do readpages asynchronously? Only set in INIT */
276 unsigned async_read : 1;
277
Miklos Szeredi095da6c2006-01-16 22:14:52 -0800278 /*
279 * The following bitfields are only for optimization purposes
280 * and hence races in setting them will not cause malfunction
281 */
282
Miklos Szeredib6aeade2005-09-09 13:10:30 -0700283 /** Is fsync not implemented by fs? */
284 unsigned no_fsync : 1;
285
Miklos Szeredi82547982005-09-09 13:10:38 -0700286 /** Is fsyncdir not implemented by fs? */
287 unsigned no_fsyncdir : 1;
288
Miklos Szeredib6aeade2005-09-09 13:10:30 -0700289 /** Is flush not implemented by fs? */
290 unsigned no_flush : 1;
291
Miklos Szeredi92a87802005-09-09 13:10:31 -0700292 /** Is setxattr not implemented by fs? */
293 unsigned no_setxattr : 1;
294
295 /** Is getxattr not implemented by fs? */
296 unsigned no_getxattr : 1;
297
298 /** Is listxattr not implemented by fs? */
299 unsigned no_listxattr : 1;
300
301 /** Is removexattr not implemented by fs? */
302 unsigned no_removexattr : 1;
303
Miklos Szeredi31d40d72005-11-07 00:59:50 -0800304 /** Is access not implemented by fs? */
305 unsigned no_access : 1;
306
Miklos Szeredifd72faa2005-11-07 00:59:51 -0800307 /** Is create not implemented by fs? */
308 unsigned no_create : 1;
309
Miklos Szeredi0cd5b882006-01-16 22:14:38 -0800310 /** The number of requests waiting for completion */
311 atomic_t num_waiting;
312
Miklos Szeredi45714d62006-01-06 00:19:36 -0800313 /** Negotiated minor version */
314 unsigned minor;
315
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700316 /** Backing dev info */
317 struct backing_dev_info bdi;
Miklos Szeredif543f252006-01-16 22:14:35 -0800318
319 /** kobject */
320 struct kobject kobj;
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700321};
322
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700323static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
324{
Miklos Szeredi6383bda2006-01-16 22:14:29 -0800325 return sb->s_fs_info;
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700326}
327
328static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
329{
330 return get_fuse_conn_super(inode->i_sb);
331}
332
Miklos Szeredif543f252006-01-16 22:14:35 -0800333static inline struct fuse_conn *get_fuse_conn_kobj(struct kobject *obj)
334{
335 return container_of(obj, struct fuse_conn, kobj);
336}
337
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700338static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
339{
340 return container_of(inode, struct fuse_inode, inode);
341}
342
343static inline u64 get_node_id(struct inode *inode)
344{
345 return get_fuse_inode(inode)->nodeid;
346}
347
Miklos Szeredi334f4852005-09-09 13:10:27 -0700348/** Device operations */
349extern struct file_operations fuse_dev_operations;
350
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700351/**
352 * This is the single global spinlock which protects FUSE's structures
353 *
354 * The following data is protected by this lock:
355 *
Miklos Szeredi334f4852005-09-09 13:10:27 -0700356 * - the private_data field of the device file
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700357 * - the s_fs_info field of the super block
Miklos Szeredi334f4852005-09-09 13:10:27 -0700358 * - unused_list, pending, processing lists in fuse_conn
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700359 * - background list in fuse_conn
Miklos Szeredi334f4852005-09-09 13:10:27 -0700360 * - the unique request ID counter reqctr in fuse_conn
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700361 * - the sb (super_block) field in fuse_conn
Miklos Szeredi334f4852005-09-09 13:10:27 -0700362 * - the file (device file) field in fuse_conn
Miklos Szeredid8a5ba42005-09-09 13:10:26 -0700363 */
364extern spinlock_t fuse_lock;
365
366/**
Miklos Szeredie5e55582005-09-09 13:10:28 -0700367 * Get a filled in inode
368 */
369struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
Miklos Szeredi9e6268d2005-09-09 13:10:29 -0700370 int generation, struct fuse_attr *attr);
Miklos Szeredie5e55582005-09-09 13:10:28 -0700371
372/**
373 * Send FORGET command
374 */
375void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
Miklos Szeredi9e6268d2005-09-09 13:10:29 -0700376 unsigned long nodeid, u64 nlookup);
Miklos Szeredie5e55582005-09-09 13:10:28 -0700377
378/**
Miklos Szeredi361b1eb52006-01-16 22:14:45 -0800379 * Initialize READ or READDIR request
Miklos Szeredi04730fe2005-09-09 13:10:36 -0700380 */
Miklos Szeredi361b1eb52006-01-16 22:14:45 -0800381void fuse_read_fill(struct fuse_req *req, struct file *file,
382 struct inode *inode, loff_t pos, size_t count, int opcode);
Miklos Szeredi04730fe2005-09-09 13:10:36 -0700383
384/**
385 * Send OPEN or OPENDIR request
386 */
387int fuse_open_common(struct inode *inode, struct file *file, int isdir);
388
Miklos Szeredifd72faa2005-11-07 00:59:51 -0800389struct fuse_file *fuse_file_alloc(void);
390void fuse_file_free(struct fuse_file *ff);
391void fuse_finish_open(struct inode *inode, struct file *file,
392 struct fuse_file *ff, struct fuse_open_out *outarg);
393
394/**
395 * Send a RELEASE request
396 */
397void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
398 u64 nodeid, struct inode *inode, int flags, int isdir);
399
Miklos Szeredi04730fe2005-09-09 13:10:36 -0700400/**
401 * Send RELEASE or RELEASEDIR request
402 */
403int fuse_release_common(struct inode *inode, struct file *file, int isdir);
404
405/**
Miklos Szeredi82547982005-09-09 13:10:38 -0700406 * Send FSYNC or FSYNCDIR request
407 */
408int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
409 int isdir);
410
411/**
Miklos Szeredi17793812005-10-30 15:02:51 -0800412 * Initialize file operations on a regular file
Miklos Szeredib6aeade2005-09-09 13:10:30 -0700413 */
414void fuse_init_file_inode(struct inode *inode);
415
416/**
Miklos Szeredi17793812005-10-30 15:02:51 -0800417 * Initialize inode operations on regular files and special files
Miklos Szeredie5e55582005-09-09 13:10:28 -0700418 */
419void fuse_init_common(struct inode *inode);
420
421/**
Miklos Szeredi17793812005-10-30 15:02:51 -0800422 * Initialize inode and file operations on a directory
Miklos Szeredie5e55582005-09-09 13:10:28 -0700423 */
424void fuse_init_dir(struct inode *inode);
425
426/**
Miklos Szeredi17793812005-10-30 15:02:51 -0800427 * Initialize inode operations on a symlink
Miklos Szeredie5e55582005-09-09 13:10:28 -0700428 */
429void fuse_init_symlink(struct inode *inode);
430
431/**
432 * Change attributes of an inode
433 */
434void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr);
435
436/**
Miklos Szeredi334f4852005-09-09 13:10:27 -0700437 * Initialize the client device
438 */
439int fuse_dev_init(void);
440
441/**
442 * Cleanup the client device
443 */
444void fuse_dev_cleanup(void);
445
446/**
447 * Allocate a request
448 */
449struct fuse_req *fuse_request_alloc(void);
450
451/**
452 * Free a request
453 */
454void fuse_request_free(struct fuse_req *req);
455
456/**
457 * Reinitialize a request, the preallocated flag is left unmodified
458 */
459void fuse_reset_request(struct fuse_req *req);
460
461/**
462 * Reserve a preallocated request
463 */
464struct fuse_req *fuse_get_request(struct fuse_conn *fc);
465
466/**
Miklos Szeredi334f4852005-09-09 13:10:27 -0700467 * Decrement reference count of a request. If count goes to zero put
Miklos Szeredi17793812005-10-30 15:02:51 -0800468 * on unused list (preallocated) or free request (not preallocated).
Miklos Szeredi334f4852005-09-09 13:10:27 -0700469 */
470void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
471
472/**
Miklos Szeredi7c352bd2005-09-09 13:10:39 -0700473 * Send a request (synchronous)
Miklos Szeredi334f4852005-09-09 13:10:27 -0700474 */
475void request_send(struct fuse_conn *fc, struct fuse_req *req);
476
477/**
Miklos Szeredi334f4852005-09-09 13:10:27 -0700478 * Send a request with no reply
479 */
480void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req);
481
482/**
483 * Send a request in the background
484 */
485void request_send_background(struct fuse_conn *fc, struct fuse_req *req);
486
487/**
Miklos Szeredi17793812005-10-30 15:02:51 -0800488 * Release inodes and file associated with background request
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700489 */
490void fuse_release_background(struct fuse_req *req);
491
Miklos Szeredi69a53bf2006-01-16 22:14:41 -0800492/* Abort all requests */
493void fuse_abort_conn(struct fuse_conn *fc);
494
Miklos Szeredi1e9a4ed2005-09-09 13:10:31 -0700495/**
Miklos Szeredie5e55582005-09-09 13:10:28 -0700496 * Get the attributes of a file
497 */
498int fuse_do_getattr(struct inode *inode);
499
500/**
501 * Invalidate inode attributes
502 */
503void fuse_invalidate_attr(struct inode *inode);