ia64/linux-2.6.18-xen.hg

view fs/fuse/fuse_i.h @ 524:7f8b544237bf

netfront: Allow netfront in domain 0.

This is useful if your physical network device is in a utility domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Tue Apr 15 15:18:58 2008 +0100 (2008-04-15)
parents 831230e53067
children
line source
1 /*
2 FUSE: Filesystem in Userspace
3 Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu>
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7 */
9 #include <linux/fuse.h>
10 #include <linux/fs.h>
11 #include <linux/mount.h>
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>
17 #include <linux/mutex.h>
19 /** Max number of pages that can be used in a single read request */
20 #define FUSE_MAX_PAGES_PER_REQ 32
22 /** Maximum number of outstanding background requests */
23 #define FUSE_MAX_BACKGROUND 10
25 /** It could be as large as PATH_MAX, but would that have any uses? */
26 #define FUSE_NAME_MAX 1024
28 /** Number of dentries for each connection in the control filesystem */
29 #define FUSE_CTL_NUM_DENTRIES 3
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)
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)
40 /** List of active connections */
41 extern struct list_head fuse_conn_list;
43 /** Global mutex protecting fuse_conn_list and the control filesystem */
44 extern struct mutex fuse_mutex;
46 /** FUSE inode */
47 struct fuse_inode {
48 /** Inode data */
49 struct inode inode;
51 /** Unique ID, which identifies the inode between userspace
52 * and kernel */
53 u64 nodeid;
55 /** Number of lookups on this inode */
56 u64 nlookup;
58 /** The request used for sending the FORGET message */
59 struct fuse_req *forget_req;
61 /** Time in jiffies until the file attributes are valid */
62 u64 i_time;
63 };
65 /** FUSE specific file data */
66 struct fuse_file {
67 /** Request reserved for flush and release */
68 struct fuse_req *reserved_req;
70 /** File handle used by userspace */
71 u64 fh;
72 };
74 /** One input argument of a request */
75 struct fuse_in_arg {
76 unsigned size;
77 const void *value;
78 };
80 /** The request input */
81 struct fuse_in {
82 /** The request header */
83 struct fuse_in_header h;
85 /** True if the data for the last argument is in req->pages */
86 unsigned argpages:1;
88 /** Number of arguments */
89 unsigned numargs;
91 /** Array of arguments */
92 struct fuse_in_arg args[3];
93 };
95 /** One output argument of a request */
96 struct fuse_arg {
97 unsigned size;
98 void *value;
99 };
101 /** The request output */
102 struct fuse_out {
103 /** Header returned from userspace */
104 struct fuse_out_header h;
106 /*
107 * The following bitfields are not changed during the request
108 * processing
109 */
111 /** Last argument is variable length (can be shorter than
112 arg->size) */
113 unsigned argvar:1;
115 /** Last argument is a list of pages to copy data to */
116 unsigned argpages:1;
118 /** Zero partially or not copied pages */
119 unsigned page_zeroing:1;
121 /** Number or arguments */
122 unsigned numargs;
124 /** Array of arguments */
125 struct fuse_arg args[3];
126 };
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_WRITING,
135 FUSE_REQ_FINISHED
136 };
138 struct fuse_conn;
140 /**
141 * A request to the client
142 */
143 struct fuse_req {
144 /** This can be on either pending processing or io lists in
145 fuse_conn */
146 struct list_head list;
148 /** Entry on the interrupts list */
149 struct list_head intr_entry;
151 /** refcount */
152 atomic_t count;
154 /** Unique ID for the interrupt request */
155 u64 intr_unique;
157 /*
158 * The following bitfields are either set once before the
159 * request is queued or setting/clearing them is protected by
160 * fuse_conn->lock
161 */
163 /** True if the request has reply */
164 unsigned isreply:1;
166 /** Force sending of the request even if interrupted */
167 unsigned force:1;
169 /** The request was aborted */
170 unsigned aborted:1;
172 /** Request is sent in the background */
173 unsigned background:1;
175 /** The request has been interrupted */
176 unsigned interrupted:1;
178 /** Data is being copied to/from the request */
179 unsigned locked:1;
181 /** Request is counted as "waiting" */
182 unsigned waiting:1;
184 /** State of the request */
185 enum fuse_req_state state;
187 /** The request input */
188 struct fuse_in in;
190 /** The request output */
191 struct fuse_out out;
193 /** Used to wake up the task waiting for completion of request*/
194 wait_queue_head_t waitq;
196 /** Data for asynchronous requests */
197 union {
198 struct fuse_forget_in forget_in;
199 struct fuse_release_in release_in;
200 struct fuse_init_in init_in;
201 struct fuse_init_out init_out;
202 struct fuse_read_in read_in;
203 struct fuse_lk_in lk_in;
204 } misc;
206 /** page vector */
207 struct page *pages[FUSE_MAX_PAGES_PER_REQ];
209 /** number of pages in vector */
210 unsigned num_pages;
212 /** offset of data on first page */
213 unsigned page_offset;
215 /** File used in the request (or NULL) */
216 struct file *file;
218 /** vfsmount used in release */
219 struct vfsmount *vfsmount;
221 /** dentry used in release */
222 struct dentry *dentry;
224 /** Request completion callback */
225 void (*end)(struct fuse_conn *, struct fuse_req *);
227 /** Request is stolen from fuse_file->reserved_req */
228 struct file *stolen_file;
229 };
231 /**
232 * A Fuse connection.
233 *
234 * This structure is created, when the filesystem is mounted, and is
235 * destroyed, when the client device is closed and the filesystem is
236 * unmounted.
237 */
238 struct fuse_conn {
239 /** Lock protecting accessess to members of this structure */
240 spinlock_t lock;
242 /** Refcount */
243 atomic_t count;
245 /** The user id for this mount */
246 uid_t user_id;
248 /** The group id for this mount */
249 gid_t group_id;
251 /** The fuse mount flags for this mount */
252 unsigned flags;
254 /** Maximum read size */
255 unsigned max_read;
257 /** Maximum write size */
258 unsigned max_write;
260 /** Readers of the connection are waiting on this */
261 wait_queue_head_t waitq;
263 /** The list of pending requests */
264 struct list_head pending;
266 /** The list of requests being processed */
267 struct list_head processing;
269 /** The list of requests under I/O */
270 struct list_head io;
272 /** Number of requests currently in the background */
273 unsigned num_background;
275 /** Pending interrupts */
276 struct list_head interrupts;
278 /** Flag indicating if connection is blocked. This will be
279 the case before the INIT reply is received, and if there
280 are too many outstading backgrounds requests */
281 int blocked;
283 /** waitq for blocked connection */
284 wait_queue_head_t blocked_waitq;
286 /** The next unique request id */
287 u64 reqctr;
289 /** Connection established, cleared on umount, connection
290 abort and device release */
291 unsigned connected;
293 /** Connection failed (version mismatch). Cannot race with
294 setting other bitfields since it is only set once in INIT
295 reply, before any other request, and never cleared */
296 unsigned conn_error : 1;
298 /** Do readpages asynchronously? Only set in INIT */
299 unsigned async_read : 1;
301 /*
302 * The following bitfields are only for optimization purposes
303 * and hence races in setting them will not cause malfunction
304 */
306 /** Is fsync not implemented by fs? */
307 unsigned no_fsync : 1;
309 /** Is fsyncdir not implemented by fs? */
310 unsigned no_fsyncdir : 1;
312 /** Is flush not implemented by fs? */
313 unsigned no_flush : 1;
315 /** Is setxattr not implemented by fs? */
316 unsigned no_setxattr : 1;
318 /** Is getxattr not implemented by fs? */
319 unsigned no_getxattr : 1;
321 /** Is listxattr not implemented by fs? */
322 unsigned no_listxattr : 1;
324 /** Is removexattr not implemented by fs? */
325 unsigned no_removexattr : 1;
327 /** Are file locking primitives not implemented by fs? */
328 unsigned no_lock : 1;
330 /** Is access not implemented by fs? */
331 unsigned no_access : 1;
333 /** Is create not implemented by fs? */
334 unsigned no_create : 1;
336 /** Is interrupt not implemented by fs? */
337 unsigned no_interrupt : 1;
339 /** The number of requests waiting for completion */
340 atomic_t num_waiting;
342 /** Negotiated minor version */
343 unsigned minor;
345 /** Backing dev info */
346 struct backing_dev_info bdi;
348 /** Entry on the fuse_conn_list */
349 struct list_head entry;
351 /** Unique ID */
352 u64 id;
354 /** Dentries in the control filesystem */
355 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
357 /** number of dentries used in the above array */
358 int ctl_ndents;
360 /** O_ASYNC requests */
361 struct fasync_struct *fasync;
363 /** Key for lock owner ID scrambling */
364 u32 scramble_key[4];
365 };
367 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
368 {
369 return sb->s_fs_info;
370 }
372 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
373 {
374 return get_fuse_conn_super(inode->i_sb);
375 }
377 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
378 {
379 return container_of(inode, struct fuse_inode, inode);
380 }
382 static inline u64 get_node_id(struct inode *inode)
383 {
384 return get_fuse_inode(inode)->nodeid;
385 }
387 /** Device operations */
388 extern const struct file_operations fuse_dev_operations;
390 /**
391 * Get a filled in inode
392 */
393 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
394 int generation, struct fuse_attr *attr);
396 /**
397 * Send FORGET command
398 */
399 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
400 unsigned long nodeid, u64 nlookup);
402 /**
403 * Initialize READ or READDIR request
404 */
405 void fuse_read_fill(struct fuse_req *req, struct file *file,
406 struct inode *inode, loff_t pos, size_t count, int opcode);
408 /**
409 * Send OPEN or OPENDIR request
410 */
411 int fuse_open_common(struct inode *inode, struct file *file, int isdir);
413 struct fuse_file *fuse_file_alloc(void);
414 void fuse_file_free(struct fuse_file *ff);
415 void fuse_finish_open(struct inode *inode, struct file *file,
416 struct fuse_file *ff, struct fuse_open_out *outarg);
418 /** */
419 struct fuse_req *fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags,
420 int opcode);
421 /**
422 * Send RELEASE or RELEASEDIR request
423 */
424 int fuse_release_common(struct inode *inode, struct file *file, int isdir);
426 /**
427 * Send FSYNC or FSYNCDIR request
428 */
429 int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
430 int isdir);
432 /**
433 * Initialize file operations on a regular file
434 */
435 void fuse_init_file_inode(struct inode *inode);
437 /**
438 * Initialize inode operations on regular files and special files
439 */
440 void fuse_init_common(struct inode *inode);
442 /**
443 * Initialize inode and file operations on a directory
444 */
445 void fuse_init_dir(struct inode *inode);
447 /**
448 * Initialize inode operations on a symlink
449 */
450 void fuse_init_symlink(struct inode *inode);
452 /**
453 * Change attributes of an inode
454 */
455 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr);
457 /**
458 * Initialize the client device
459 */
460 int fuse_dev_init(void);
462 /**
463 * Cleanup the client device
464 */
465 void fuse_dev_cleanup(void);
467 int fuse_ctl_init(void);
468 void fuse_ctl_cleanup(void);
470 /**
471 * Allocate a request
472 */
473 struct fuse_req *fuse_request_alloc(void);
475 /**
476 * Free a request
477 */
478 void fuse_request_free(struct fuse_req *req);
480 /**
481 * Get a request, may fail with -ENOMEM
482 */
483 struct fuse_req *fuse_get_req(struct fuse_conn *fc);
485 /**
486 * Gets a requests for a file operation, always succeeds
487 */
488 struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file);
490 /**
491 * Decrement reference count of a request. If count goes to zero free
492 * the request.
493 */
494 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
496 /**
497 * Send a request (synchronous)
498 */
499 void request_send(struct fuse_conn *fc, struct fuse_req *req);
501 /**
502 * Send a request with no reply
503 */
504 void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req);
506 /**
507 * Send a request in the background
508 */
509 void request_send_background(struct fuse_conn *fc, struct fuse_req *req);
511 /* Abort all requests */
512 void fuse_abort_conn(struct fuse_conn *fc);
514 /**
515 * Get the attributes of a file
516 */
517 int fuse_do_getattr(struct inode *inode);
519 /**
520 * Invalidate inode attributes
521 */
522 void fuse_invalidate_attr(struct inode *inode);
524 /**
525 * Acquire reference to fuse_conn
526 */
527 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
529 /**
530 * Release reference to fuse_conn
531 */
532 void fuse_conn_put(struct fuse_conn *fc);
534 /**
535 * Add connection to control filesystem
536 */
537 int fuse_ctl_add_conn(struct fuse_conn *fc);
539 /**
540 * Remove connection from control filesystem
541 */
542 void fuse_ctl_remove_conn(struct fuse_conn *fc);