Merge branch 'topic/asoc' into for-linus
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / fuse / fuse_i.h
CommitLineData
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1/*
2 FUSE: Filesystem in Userspace
1729a16c 3 Copyright (C) 2001-2008 Miklos Szeredi <miklos@szeredi.hu>
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4
5 This program can be distributed under the terms of the GNU GPL.
6 See the file COPYING.
7*/
8
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9#ifndef _FS_FUSE_I_H
10#define _FS_FUSE_I_H
11
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12#include <linux/fuse.h>
13#include <linux/fs.h>
51eb01e7 14#include <linux/mount.h>
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15#include <linux/wait.h>
16#include <linux/list.h>
17#include <linux/spinlock.h>
18#include <linux/mm.h>
19#include <linux/backing-dev.h>
bafa9654 20#include <linux/mutex.h>
3be5a52b 21#include <linux/rwsem.h>
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22#include <linux/rbtree.h>
23#include <linux/poll.h>
d8a5ba45 24
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25/** Max number of pages that can be used in a single read request */
26#define FUSE_MAX_PAGES_PER_REQ 32
27
08a53cdc 28/** Maximum number of outstanding background requests */
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29#define FUSE_MAX_BACKGROUND 12
30
31/** Congestion starts at 75% of maximum */
32#define FUSE_CONGESTION_THRESHOLD (FUSE_MAX_BACKGROUND * 75 / 100)
08a53cdc 33
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34/** Bias for fi->writectr, meaning new writepages must not be sent */
35#define FUSE_NOWRITE INT_MIN
36
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37/** It could be as large as PATH_MAX, but would that have any uses? */
38#define FUSE_NAME_MAX 1024
39
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40/** Number of dentries for each connection in the control filesystem */
41#define FUSE_CTL_NUM_DENTRIES 3
42
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43/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
44 module will check permissions based on the file mode. Otherwise no
45 permission checking is done in the kernel */
46#define FUSE_DEFAULT_PERMISSIONS (1 << 0)
47
48/** If the FUSE_ALLOW_OTHER flag is given, then not only the user
49 doing the mount will be allowed to access the filesystem */
50#define FUSE_ALLOW_OTHER (1 << 1)
51
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52/** List of active connections */
53extern struct list_head fuse_conn_list;
54
55/** Global mutex protecting fuse_conn_list and the control filesystem */
56extern struct mutex fuse_mutex;
413ef8cb 57
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58/** FUSE inode */
59struct fuse_inode {
60 /** Inode data */
61 struct inode inode;
62
63 /** Unique ID, which identifies the inode between userspace
64 * and kernel */
65 u64 nodeid;
66
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67 /** Number of lookups on this inode */
68 u64 nlookup;
69
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70 /** The request used for sending the FORGET message */
71 struct fuse_req *forget_req;
72
d8a5ba45 73 /** Time in jiffies until the file attributes are valid */
0a0898cf 74 u64 i_time;
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75
76 /** The sticky bit in inode->i_mode may have been removed, so
77 preserve the original mode */
78 mode_t orig_i_mode;
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79
80 /** Version of last attribute change */
81 u64 attr_version;
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82
83 /** Files usable in writepage. Protected by fc->lock */
84 struct list_head write_files;
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85
86 /** Writepages pending on truncate or fsync */
87 struct list_head queued_writes;
88
89 /** Number of sent writes, a negative bias (FUSE_NOWRITE)
90 * means more writes are blocked */
91 int writectr;
92
93 /** Waitq for writepage completion */
94 wait_queue_head_t page_waitq;
95
96 /** List of writepage requestst (pending or sent) */
97 struct list_head writepages;
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98};
99
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100/** FUSE specific file data */
101struct fuse_file {
102 /** Request reserved for flush and release */
33649c91 103 struct fuse_req *reserved_req;
b6aeaded 104
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105 /** Kernel file handle guaranteed to be unique */
106 u64 kh;
107
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108 /** File handle used by userspace */
109 u64 fh;
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110
111 /** Refcount */
112 atomic_t count;
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113
114 /** Entry on inode's write_files list */
115 struct list_head write_entry;
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116
117 /** RB node to be linked on fuse_conn->polled_files */
118 struct rb_node polled_node;
119
120 /** Wait queue head for poll */
121 wait_queue_head_t poll_wait;
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122};
123
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124/** One input argument of a request */
125struct fuse_in_arg {
126 unsigned size;
127 const void *value;
128};
129
130/** The request input */
131struct fuse_in {
132 /** The request header */
133 struct fuse_in_header h;
134
135 /** True if the data for the last argument is in req->pages */
136 unsigned argpages:1;
137
138 /** Number of arguments */
139 unsigned numargs;
140
141 /** Array of arguments */
142 struct fuse_in_arg args[3];
143};
144
145/** One output argument of a request */
146struct fuse_arg {
147 unsigned size;
148 void *value;
149};
150
151/** The request output */
152struct fuse_out {
153 /** Header returned from userspace */
154 struct fuse_out_header h;
155
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156 /*
157 * The following bitfields are not changed during the request
158 * processing
159 */
160
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161 /** Last argument is variable length (can be shorter than
162 arg->size) */
163 unsigned argvar:1;
164
165 /** Last argument is a list of pages to copy data to */
166 unsigned argpages:1;
167
168 /** Zero partially or not copied pages */
169 unsigned page_zeroing:1;
170
171 /** Number or arguments */
172 unsigned numargs;
173
174 /** Array of arguments */
175 struct fuse_arg args[3];
176};
177
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178/** The request state */
179enum fuse_req_state {
180 FUSE_REQ_INIT = 0,
181 FUSE_REQ_PENDING,
182 FUSE_REQ_READING,
183 FUSE_REQ_SENT,
a4d27e75 184 FUSE_REQ_WRITING,
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185 FUSE_REQ_FINISHED
186};
187
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188struct fuse_conn;
189
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190/**
191 * A request to the client
192 */
193struct fuse_req {
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194 /** This can be on either pending processing or io lists in
195 fuse_conn */
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196 struct list_head list;
197
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198 /** Entry on the interrupts list */
199 struct list_head intr_entry;
200
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201 /** refcount */
202 atomic_t count;
203
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204 /** Unique ID for the interrupt request */
205 u64 intr_unique;
206
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207 /*
208 * The following bitfields are either set once before the
209 * request is queued or setting/clearing them is protected by
d7133114 210 * fuse_conn->lock
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211 */
212
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213 /** True if the request has reply */
214 unsigned isreply:1;
215
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216 /** Force sending of the request even if interrupted */
217 unsigned force:1;
218
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219 /** The request was aborted */
220 unsigned aborted:1;
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221
222 /** Request is sent in the background */
223 unsigned background:1;
224
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225 /** The request has been interrupted */
226 unsigned interrupted:1;
227
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228 /** Data is being copied to/from the request */
229 unsigned locked:1;
230
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231 /** Request is counted as "waiting" */
232 unsigned waiting:1;
233
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234 /** State of the request */
235 enum fuse_req_state state;
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236
237 /** The request input */
238 struct fuse_in in;
239
240 /** The request output */
241 struct fuse_out out;
242
243 /** Used to wake up the task waiting for completion of request*/
244 wait_queue_head_t waitq;
245
246 /** Data for asynchronous requests */
247 union {
e5e5558e 248 struct fuse_forget_in forget_in;
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249 struct {
250 struct fuse_release_in in;
251 struct vfsmount *vfsmount;
252 struct dentry *dentry;
253 } release;
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254 struct fuse_init_in init_in;
255 struct fuse_init_out init_out;
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256 struct {
257 struct fuse_read_in in;
258 u64 attr_ver;
259 } read;
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260 struct {
261 struct fuse_write_in in;
262 struct fuse_write_out out;
263 } write;
71421259 264 struct fuse_lk_in lk_in;
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265 } misc;
266
267 /** page vector */
268 struct page *pages[FUSE_MAX_PAGES_PER_REQ];
269
270 /** number of pages in vector */
271 unsigned num_pages;
272
273 /** offset of data on first page */
274 unsigned page_offset;
275
334f485d 276 /** File used in the request (or NULL) */
c756e0a4 277 struct fuse_file *ff;
64c6d8ed 278
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279 /** Inode used in the request or NULL */
280 struct inode *inode;
281
282 /** Link on fi->writepages */
283 struct list_head writepages_entry;
284
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285 /** Request completion callback */
286 void (*end)(struct fuse_conn *, struct fuse_req *);
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287
288 /** Request is stolen from fuse_file->reserved_req */
289 struct file *stolen_file;
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290};
291
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292/**
293 * A Fuse connection.
294 *
295 * This structure is created, when the filesystem is mounted, and is
296 * destroyed, when the client device is closed and the filesystem is
297 * unmounted.
298 */
299struct fuse_conn {
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300 /** Lock protecting accessess to members of this structure */
301 spinlock_t lock;
302
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303 /** Mutex protecting against directory alias creation */
304 struct mutex inst_mutex;
305
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306 /** Refcount */
307 atomic_t count;
308
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309 /** The user id for this mount */
310 uid_t user_id;
311
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312 /** The group id for this mount */
313 gid_t group_id;
314
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315 /** The fuse mount flags for this mount */
316 unsigned flags;
317
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318 /** Maximum read size */
319 unsigned max_read;
320
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321 /** Maximum write size */
322 unsigned max_write;
323
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324 /** Readers of the connection are waiting on this */
325 wait_queue_head_t waitq;
326
327 /** The list of pending requests */
328 struct list_head pending;
329
330 /** The list of requests being processed */
331 struct list_head processing;
332
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333 /** The list of requests under I/O */
334 struct list_head io;
335
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336 /** The next unique kernel file handle */
337 u64 khctr;
338
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339 /** rbtree of fuse_files waiting for poll events indexed by ph */
340 struct rb_root polled_files;
341
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342 /** Number of requests currently in the background */
343 unsigned num_background;
344
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345 /** Number of background requests currently queued for userspace */
346 unsigned active_background;
347
348 /** The list of background requests set aside for later queuing */
349 struct list_head bg_queue;
350
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351 /** Pending interrupts */
352 struct list_head interrupts;
353
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354 /** Flag indicating if connection is blocked. This will be
355 the case before the INIT reply is received, and if there
356 are too many outstading backgrounds requests */
357 int blocked;
358
359 /** waitq for blocked connection */
360 wait_queue_head_t blocked_waitq;
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361
362 /** waitq for reserved requests */
363 wait_queue_head_t reserved_req_waitq;
08a53cdc 364
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365 /** The next unique request id */
366 u64 reqctr;
367
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368 /** Connection established, cleared on umount, connection
369 abort and device release */
095da6cb 370 unsigned connected;
1e9a4ed9 371
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372 /** Connection failed (version mismatch). Cannot race with
373 setting other bitfields since it is only set once in INIT
374 reply, before any other request, and never cleared */
1729a16c 375 unsigned conn_error:1;
334f485d 376
0ec7ca41 377 /** Connection successful. Only set in INIT */
1729a16c 378 unsigned conn_init:1;
0ec7ca41 379
9cd68455 380 /** Do readpages asynchronously? Only set in INIT */
1729a16c 381 unsigned async_read:1;
9cd68455 382
6ff958ed 383 /** Do not send separate SETATTR request before open(O_TRUNC) */
1729a16c 384 unsigned atomic_o_trunc:1;
6ff958ed 385
33670fa2 386 /** Filesystem supports NFS exporting. Only set in INIT */
1729a16c 387 unsigned export_support:1;
33670fa2 388
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389 /*
390 * The following bitfields are only for optimization purposes
391 * and hence races in setting them will not cause malfunction
392 */
393
b6aeaded 394 /** Is fsync not implemented by fs? */
1729a16c 395 unsigned no_fsync:1;
b6aeaded 396
82547981 397 /** Is fsyncdir not implemented by fs? */
1729a16c 398 unsigned no_fsyncdir:1;
82547981 399
b6aeaded 400 /** Is flush not implemented by fs? */
1729a16c 401 unsigned no_flush:1;
b6aeaded 402
92a8780e 403 /** Is setxattr not implemented by fs? */
1729a16c 404 unsigned no_setxattr:1;
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405
406 /** Is getxattr not implemented by fs? */
1729a16c 407 unsigned no_getxattr:1;
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408
409 /** Is listxattr not implemented by fs? */
1729a16c 410 unsigned no_listxattr:1;
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411
412 /** Is removexattr not implemented by fs? */
1729a16c 413 unsigned no_removexattr:1;
92a8780e 414
71421259 415 /** Are file locking primitives not implemented by fs? */
1729a16c 416 unsigned no_lock:1;
71421259 417
31d40d74 418 /** Is access not implemented by fs? */
1729a16c 419 unsigned no_access:1;
31d40d74 420
fd72faac 421 /** Is create not implemented by fs? */
1729a16c 422 unsigned no_create:1;
fd72faac 423
a4d27e75 424 /** Is interrupt not implemented by fs? */
1729a16c 425 unsigned no_interrupt:1;
a4d27e75 426
b2d2272f 427 /** Is bmap not implemented by fs? */
1729a16c 428 unsigned no_bmap:1;
b2d2272f 429
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430 /** Is poll not implemented by fs? */
431 unsigned no_poll:1;
432
78bb6cb9 433 /** Do multi-page cached writes */
1729a16c 434 unsigned big_writes:1;
78bb6cb9 435
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436 /** The number of requests waiting for completion */
437 atomic_t num_waiting;
438
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439 /** Negotiated minor version */
440 unsigned minor;
441
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442 /** Backing dev info */
443 struct backing_dev_info bdi;
f543f253 444
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445 /** Entry on the fuse_conn_list */
446 struct list_head entry;
447
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448 /** Device ID from super block */
449 dev_t dev;
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450
451 /** Dentries in the control filesystem */
452 struct dentry *ctl_dentry[FUSE_CTL_NUM_DENTRIES];
453
454 /** number of dentries used in the above array */
455 int ctl_ndents;
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456
457 /** O_ASYNC requests */
458 struct fasync_struct *fasync;
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459
460 /** Key for lock owner ID scrambling */
461 u32 scramble_key[4];
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462
463 /** Reserved request for the DESTROY message */
464 struct fuse_req *destroy_req;
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465
466 /** Version counter for attribute changes */
467 u64 attr_version;
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468
469 /** Called on final put */
470 void (*release)(struct fuse_conn *);
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471};
472
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473static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
474{
6383bdaa 475 return sb->s_fs_info;
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476}
477
478static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
479{
480 return get_fuse_conn_super(inode->i_sb);
481}
482
483static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
484{
485 return container_of(inode, struct fuse_inode, inode);
486}
487
488static inline u64 get_node_id(struct inode *inode)
489{
490 return get_fuse_inode(inode)->nodeid;
491}
492
334f485d 493/** Device operations */
4b6f5d20 494extern const struct file_operations fuse_dev_operations;
334f485d 495
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496extern struct dentry_operations fuse_dentry_operations;
497
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498/**
499 * Get a filled in inode
500 */
b48badf0 501struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
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502 int generation, struct fuse_attr *attr,
503 u64 attr_valid, u64 attr_version);
e5e5558e 504
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505int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
506 struct fuse_entry_out *outarg, struct inode **inode);
507
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508/**
509 * Send FORGET command
510 */
511void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
b48badf0 512 u64 nodeid, u64 nlookup);
e5e5558e 513
04730fef 514/**
361b1eb5 515 * Initialize READ or READDIR request
04730fef 516 */
a6643094 517void fuse_read_fill(struct fuse_req *req, struct file *file,
361b1eb5 518 struct inode *inode, loff_t pos, size_t count, int opcode);
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519
520/**
521 * Send OPEN or OPENDIR request
522 */
523int fuse_open_common(struct inode *inode, struct file *file, int isdir);
524
acf99433 525struct fuse_file *fuse_file_alloc(struct fuse_conn *fc);
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526void fuse_file_free(struct fuse_file *ff);
527void fuse_finish_open(struct inode *inode, struct file *file,
528 struct fuse_file *ff, struct fuse_open_out *outarg);
529
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530/** Fill in ff->reserved_req with a RELEASE request */
531void fuse_release_fill(struct fuse_file *ff, u64 nodeid, int flags, int opcode);
532
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533/**
534 * Send RELEASE or RELEASEDIR request
535 */
536int fuse_release_common(struct inode *inode, struct file *file, int isdir);
537
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538/**
539 * Send FSYNC or FSYNCDIR request
540 */
541int fuse_fsync_common(struct file *file, struct dentry *de, int datasync,
542 int isdir);
543
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544/**
545 * Notify poll wakeup
546 */
547int fuse_notify_poll_wakeup(struct fuse_conn *fc,
548 struct fuse_notify_poll_wakeup_out *outarg);
549
b6aeaded 550/**
1779381d 551 * Initialize file operations on a regular file
b6aeaded
MS
552 */
553void fuse_init_file_inode(struct inode *inode);
554
e5e5558e 555/**
1779381d 556 * Initialize inode operations on regular files and special files
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557 */
558void fuse_init_common(struct inode *inode);
559
560/**
1779381d 561 * Initialize inode and file operations on a directory
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562 */
563void fuse_init_dir(struct inode *inode);
564
565/**
1779381d 566 * Initialize inode operations on a symlink
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567 */
568void fuse_init_symlink(struct inode *inode);
569
570/**
571 * Change attributes of an inode
572 */
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573void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
574 u64 attr_valid, u64 attr_version);
e5e5558e 575
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576void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
577 u64 attr_valid);
578
579void fuse_truncate(struct address_space *mapping, loff_t offset);
580
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581/**
582 * Initialize the client device
583 */
584int fuse_dev_init(void);
585
586/**
587 * Cleanup the client device
588 */
589void fuse_dev_cleanup(void);
590
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591int fuse_ctl_init(void);
592void fuse_ctl_cleanup(void);
593
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594/**
595 * Allocate a request
596 */
597struct fuse_req *fuse_request_alloc(void);
598
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599struct fuse_req *fuse_request_alloc_nofs(void);
600
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601/**
602 * Free a request
603 */
604void fuse_request_free(struct fuse_req *req);
605
334f485d 606/**
33649c91 607 * Get a request, may fail with -ENOMEM
334f485d 608 */
ce1d5a49 609struct fuse_req *fuse_get_req(struct fuse_conn *fc);
334f485d 610
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611/**
612 * Gets a requests for a file operation, always succeeds
613 */
614struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file);
615
334f485d 616/**
ce1d5a49
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617 * Decrement reference count of a request. If count goes to zero free
618 * the request.
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619 */
620void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req);
621
622/**
7c352bdf 623 * Send a request (synchronous)
334f485d 624 */
b93f858a 625void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req);
334f485d 626
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627/**
628 * Send a request with no reply
629 */
b93f858a 630void fuse_request_send_noreply(struct fuse_conn *fc, struct fuse_req *req);
334f485d
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631
632/**
633 * Send a request in the background
634 */
b93f858a 635void fuse_request_send_background(struct fuse_conn *fc, struct fuse_req *req);
334f485d 636
b93f858a
TH
637void fuse_request_send_background_locked(struct fuse_conn *fc,
638 struct fuse_req *req);
3be5a52b 639
5a5fb1ea 640/* Abort all requests */
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641void fuse_abort_conn(struct fuse_conn *fc);
642
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643/**
644 * Invalidate inode attributes
645 */
646void fuse_invalidate_attr(struct inode *inode);
bafa9654 647
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648void fuse_invalidate_entry_cache(struct dentry *entry);
649
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650/**
651 * Acquire reference to fuse_conn
652 */
653struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
654
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TH
655/**
656 * Initialize fuse_conn
657 */
658int fuse_conn_init(struct fuse_conn *fc, struct super_block *sb);
659
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660/**
661 * Release reference to fuse_conn
662 */
663void fuse_conn_put(struct fuse_conn *fc);
664
665/**
666 * Add connection to control filesystem
667 */
668int fuse_ctl_add_conn(struct fuse_conn *fc);
669
670/**
671 * Remove connection from control filesystem
672 */
673void fuse_ctl_remove_conn(struct fuse_conn *fc);
a5bfffac
TS
674
675/**
676 * Is file type valid?
677 */
678int fuse_valid_type(int m);
e57ac683
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679
680/**
681 * Is task allowed to perform filesystem operation?
682 */
683int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task);
f3332114
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684
685u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
bcb4be80
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686
687int fuse_update_attributes(struct inode *inode, struct kstat *stat,
688 struct file *file, bool *refreshed);
3be5a52b
MS
689
690void fuse_flush_writepages(struct inode *inode);
691
692void fuse_set_nowrite(struct inode *inode);
693void fuse_release_nowrite(struct inode *inode);
5c5c5e51
MS
694
695u64 fuse_get_attr_version(struct fuse_conn *fc);
29d434b3
TH
696
697#endif /* _FS_FUSE_I_H */