xref: /linux/include/uapi/linux/fuse.h (revision 6238729bfce13f94b701766996a5d116d2df8bff)
1 /* SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) */
2 /*
3     This file defines the kernel interface of FUSE
4     Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
5 
6     This program can be distributed under the terms of the GNU GPL.
7     See the file COPYING.
8 
9     This -- and only this -- header file may also be distributed under
10     the terms of the BSD Licence as follows:
11 
12     Copyright (C) 2001-2007 Miklos Szeredi. All rights reserved.
13 
14     Redistribution and use in source and binary forms, with or without
15     modification, are permitted provided that the following conditions
16     are met:
17     1. Redistributions of source code must retain the above copyright
18        notice, this list of conditions and the following disclaimer.
19     2. Redistributions in binary form must reproduce the above copyright
20        notice, this list of conditions and the following disclaimer in the
21        documentation and/or other materials provided with the distribution.
22 
23     THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24     ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26     ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
27     FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28     DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29     OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31     LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33     SUCH DAMAGE.
34 */
35 
36 /*
37  * This file defines the kernel interface of FUSE
38  *
39  * Protocol changelog:
40  *
41  * 7.1:
42  *  - add the following messages:
43  *      FUSE_SETATTR, FUSE_SYMLINK, FUSE_MKNOD, FUSE_MKDIR, FUSE_UNLINK,
44  *      FUSE_RMDIR, FUSE_RENAME, FUSE_LINK, FUSE_OPEN, FUSE_READ, FUSE_WRITE,
45  *      FUSE_RELEASE, FUSE_FSYNC, FUSE_FLUSH, FUSE_SETXATTR, FUSE_GETXATTR,
46  *      FUSE_LISTXATTR, FUSE_REMOVEXATTR, FUSE_OPENDIR, FUSE_READDIR,
47  *      FUSE_RELEASEDIR
48  *  - add padding to messages to accommodate 32-bit servers on 64-bit kernels
49  *
50  * 7.2:
51  *  - add FOPEN_DIRECT_IO and FOPEN_KEEP_CACHE flags
52  *  - add FUSE_FSYNCDIR message
53  *
54  * 7.3:
55  *  - add FUSE_ACCESS message
56  *  - add FUSE_CREATE message
57  *  - add filehandle to fuse_setattr_in
58  *
59  * 7.4:
60  *  - add frsize to fuse_kstatfs
61  *  - clean up request size limit checking
62  *
63  * 7.5:
64  *  - add flags and max_write to fuse_init_out
65  *
66  * 7.6:
67  *  - add max_readahead to fuse_init_in and fuse_init_out
68  *
69  * 7.7:
70  *  - add FUSE_INTERRUPT message
71  *  - add POSIX file lock support
72  *
73  * 7.8:
74  *  - add lock_owner and flags fields to fuse_release_in
75  *  - add FUSE_BMAP message
76  *  - add FUSE_DESTROY message
77  *
78  * 7.9:
79  *  - new fuse_getattr_in input argument of GETATTR
80  *  - add lk_flags in fuse_lk_in
81  *  - add lock_owner field to fuse_setattr_in, fuse_read_in and fuse_write_in
82  *  - add blksize field to fuse_attr
83  *  - add file flags field to fuse_read_in and fuse_write_in
84  *  - Add ATIME_NOW and MTIME_NOW flags to fuse_setattr_in
85  *
86  * 7.10
87  *  - add nonseekable open flag
88  *
89  * 7.11
90  *  - add IOCTL message
91  *  - add unsolicited notification support
92  *  - add POLL message and NOTIFY_POLL notification
93  *
94  * 7.12
95  *  - add umask flag to input argument of create, mknod and mkdir
96  *  - add notification messages for invalidation of inodes and
97  *    directory entries
98  *
99  * 7.13
100  *  - make max number of background requests and congestion threshold
101  *    tunables
102  *
103  * 7.14
104  *  - add splice support to fuse device
105  *
106  * 7.15
107  *  - add store notify
108  *  - add retrieve notify
109  *
110  * 7.16
111  *  - add BATCH_FORGET request
112  *  - FUSE_IOCTL_UNRESTRICTED shall now return with array of 'struct
113  *    fuse_ioctl_iovec' instead of ambiguous 'struct iovec'
114  *  - add FUSE_IOCTL_32BIT flag
115  *
116  * 7.17
117  *  - add FUSE_FLOCK_LOCKS and FUSE_RELEASE_FLOCK_UNLOCK
118  *
119  * 7.18
120  *  - add FUSE_IOCTL_DIR flag
121  *  - add FUSE_NOTIFY_DELETE
122  *
123  * 7.19
124  *  - add FUSE_FALLOCATE
125  *
126  * 7.20
127  *  - add FUSE_AUTO_INVAL_DATA
128  *
129  * 7.21
130  *  - add FUSE_READDIRPLUS
131  *  - send the requested events in POLL request
132  *
133  * 7.22
134  *  - add FUSE_ASYNC_DIO
135  *
136  * 7.23
137  *  - add FUSE_WRITEBACK_CACHE
138  *  - add time_gran to fuse_init_out
139  *  - add reserved space to fuse_init_out
140  *  - add FATTR_CTIME
141  *  - add ctime and ctimensec to fuse_setattr_in
142  *  - add FUSE_RENAME2 request
143  *  - add FUSE_NO_OPEN_SUPPORT flag
144  *
145  *  7.24
146  *  - add FUSE_LSEEK for SEEK_HOLE and SEEK_DATA support
147  *
148  *  7.25
149  *  - add FUSE_PARALLEL_DIROPS
150  *
151  *  7.26
152  *  - add FUSE_HANDLE_KILLPRIV
153  *  - add FUSE_POSIX_ACL
154  *
155  *  7.27
156  *  - add FUSE_ABORT_ERROR
157  *
158  *  7.28
159  *  - add FUSE_COPY_FILE_RANGE
160  *  - add FOPEN_CACHE_DIR
161  *  - add FUSE_MAX_PAGES, add max_pages to init_out
162  *  - add FUSE_CACHE_SYMLINKS
163  *
164  *  7.29
165  *  - add FUSE_NO_OPENDIR_SUPPORT flag
166  *
167  *  7.30
168  *  - add FUSE_EXPLICIT_INVAL_DATA
169  *  - add FUSE_IOCTL_COMPAT_X32
170  *
171  *  7.31
172  *  - add FUSE_WRITE_KILL_PRIV flag
173  *  - add FUSE_SETUPMAPPING and FUSE_REMOVEMAPPING
174  *  - add map_alignment to fuse_init_out, add FUSE_MAP_ALIGNMENT flag
175  *
176  *  7.32
177  *  - add flags to fuse_attr, add FUSE_ATTR_SUBMOUNT, add FUSE_SUBMOUNTS
178  *
179  *  7.33
180  *  - add FUSE_HANDLE_KILLPRIV_V2, FUSE_WRITE_KILL_SUIDGID, FATTR_KILL_SUIDGID
181  *  - add FUSE_OPEN_KILL_SUIDGID
182  *  - extend fuse_setxattr_in, add FUSE_SETXATTR_EXT
183  *  - add FUSE_SETXATTR_ACL_KILL_SGID
184  *
185  *  7.34
186  *  - add FUSE_SYNCFS
187  *
188  *  7.35
189  *  - add FOPEN_NOFLUSH
190  *
191  *  7.36
192  *  - extend fuse_init_in with reserved fields, add FUSE_INIT_EXT init flag
193  *  - add flags2 to fuse_init_in and fuse_init_out
194  *  - add FUSE_SECURITY_CTX init flag
195  *  - add security context to create, mkdir, symlink, and mknod requests
196  *  - add FUSE_HAS_INODE_DAX, FUSE_ATTR_DAX
197  *
198  *  7.37
199  *  - add FUSE_TMPFILE
200  *
201  *  7.38
202  *  - add FUSE_EXPIRE_ONLY flag to fuse_notify_inval_entry
203  *  - add FOPEN_PARALLEL_DIRECT_WRITES
204  *  - add total_extlen to fuse_in_header
205  *  - add FUSE_MAX_NR_SECCTX
206  *  - add extension header
207  *  - add FUSE_EXT_GROUPS
208  *  - add FUSE_CREATE_SUPP_GROUP
209  *  - add FUSE_HAS_EXPIRE_ONLY
210  *
211  *  7.39
212  *  - add FUSE_DIRECT_IO_ALLOW_MMAP
213  *  - add FUSE_STATX and related structures
214  *
215  *  7.40
216  *  - add max_stack_depth to fuse_init_out, add FUSE_PASSTHROUGH init flag
217  *  - add backing_id to fuse_open_out, add FOPEN_PASSTHROUGH open flag
218  *  - add FUSE_NO_EXPORT_SUPPORT init flag
219  *  - add FUSE_NOTIFY_RESEND, add FUSE_HAS_RESEND init flag
220  *
221  *  7.41
222  *  - add FUSE_ALLOW_IDMAP
223  *  7.42
224  *  - Add FUSE_OVER_IO_URING and all other io-uring related flags and data
225  *    structures:
226  *    - struct fuse_uring_ent_in_out
227  *    - struct fuse_uring_req_header
228  *    - struct fuse_uring_cmd_req
229  *    - FUSE_URING_IN_OUT_HEADER_SZ
230  *    - FUSE_URING_OP_IN_OUT_SZ
231  *    - enum fuse_uring_cmd
232  *
233  *  7.43
234  *  - add FUSE_REQUEST_TIMEOUT
235  *
236  *  7.44
237  *  - add FUSE_NOTIFY_INC_EPOCH
238  *
239  *  7.45
240  *  - add FUSE_COPY_FILE_RANGE_64
241  *  - add struct fuse_copy_file_range_out
242  *  - add FUSE_NOTIFY_PRUNE
243  */
244 
245 #ifndef _LINUX_FUSE_H
246 #define _LINUX_FUSE_H
247 
248 #ifdef __KERNEL__
249 #include <linux/types.h>
250 #else
251 #include <stdint.h>
252 #endif
253 
254 /*
255  * Version negotiation:
256  *
257  * Both the kernel and userspace send the version they support in the
258  * INIT request and reply respectively.
259  *
260  * If the major versions match then both shall use the smallest
261  * of the two minor versions for communication.
262  *
263  * If the kernel supports a larger major version, then userspace shall
264  * reply with the major version it supports, ignore the rest of the
265  * INIT message and expect a new INIT message from the kernel with a
266  * matching major version.
267  *
268  * If the library supports a larger major version, then it shall fall
269  * back to the major protocol version sent by the kernel for
270  * communication and reply with that major version (and an arbitrary
271  * supported minor version).
272  */
273 
274 /** Version number of this interface */
275 #define FUSE_KERNEL_VERSION 7
276 
277 /** Minor version number of this interface */
278 #define FUSE_KERNEL_MINOR_VERSION 45
279 
280 /** The node ID of the root inode */
281 #define FUSE_ROOT_ID 1
282 
283 /* Make sure all structures are padded to 64bit boundary, so 32bit
284    userspace works under 64bit kernels */
285 
286 struct fuse_attr {
287 	uint64_t	ino;
288 	uint64_t	size;
289 	uint64_t	blocks;
290 	uint64_t	atime;
291 	uint64_t	mtime;
292 	uint64_t	ctime;
293 	uint32_t	atimensec;
294 	uint32_t	mtimensec;
295 	uint32_t	ctimensec;
296 	uint32_t	mode;
297 	uint32_t	nlink;
298 	uint32_t	uid;
299 	uint32_t	gid;
300 	uint32_t	rdev;
301 	uint32_t	blksize;
302 	uint32_t	flags;
303 };
304 
305 /*
306  * The following structures are bit-for-bit compatible with the statx(2) ABI in
307  * Linux.
308  */
309 struct fuse_sx_time {
310 	int64_t		tv_sec;
311 	uint32_t	tv_nsec;
312 	int32_t		__reserved;
313 };
314 
315 struct fuse_statx {
316 	uint32_t	mask;
317 	uint32_t	blksize;
318 	uint64_t	attributes;
319 	uint32_t	nlink;
320 	uint32_t	uid;
321 	uint32_t	gid;
322 	uint16_t	mode;
323 	uint16_t	__spare0[1];
324 	uint64_t	ino;
325 	uint64_t	size;
326 	uint64_t	blocks;
327 	uint64_t	attributes_mask;
328 	struct fuse_sx_time	atime;
329 	struct fuse_sx_time	btime;
330 	struct fuse_sx_time	ctime;
331 	struct fuse_sx_time	mtime;
332 	uint32_t	rdev_major;
333 	uint32_t	rdev_minor;
334 	uint32_t	dev_major;
335 	uint32_t	dev_minor;
336 	uint64_t	__spare2[14];
337 };
338 
339 struct fuse_kstatfs {
340 	uint64_t	blocks;
341 	uint64_t	bfree;
342 	uint64_t	bavail;
343 	uint64_t	files;
344 	uint64_t	ffree;
345 	uint32_t	bsize;
346 	uint32_t	namelen;
347 	uint32_t	frsize;
348 	uint32_t	padding;
349 	uint32_t	spare[6];
350 };
351 
352 struct fuse_file_lock {
353 	uint64_t	start;
354 	uint64_t	end;
355 	uint32_t	type;
356 	uint32_t	pid; /* tgid */
357 };
358 
359 /**
360  * Bitmasks for fuse_setattr_in.valid
361  */
362 #define FATTR_MODE	(1 << 0)
363 #define FATTR_UID	(1 << 1)
364 #define FATTR_GID	(1 << 2)
365 #define FATTR_SIZE	(1 << 3)
366 #define FATTR_ATIME	(1 << 4)
367 #define FATTR_MTIME	(1 << 5)
368 #define FATTR_FH	(1 << 6)
369 #define FATTR_ATIME_NOW	(1 << 7)
370 #define FATTR_MTIME_NOW	(1 << 8)
371 #define FATTR_LOCKOWNER	(1 << 9)
372 #define FATTR_CTIME	(1 << 10)
373 #define FATTR_KILL_SUIDGID	(1 << 11)
374 
375 /**
376  * Flags returned by the OPEN request
377  *
378  * FOPEN_DIRECT_IO: bypass page cache for this open file
379  * FOPEN_KEEP_CACHE: don't invalidate the data cache on open
380  * FOPEN_NONSEEKABLE: the file is not seekable
381  * FOPEN_CACHE_DIR: allow caching this directory
382  * FOPEN_STREAM: the file is stream-like (no file position at all)
383  * FOPEN_NOFLUSH: don't flush data cache on close (unless FUSE_WRITEBACK_CACHE)
384  * FOPEN_PARALLEL_DIRECT_WRITES: Allow concurrent direct writes on the same inode
385  * FOPEN_PASSTHROUGH: passthrough read/write io for this open file
386  */
387 #define FOPEN_DIRECT_IO		(1 << 0)
388 #define FOPEN_KEEP_CACHE	(1 << 1)
389 #define FOPEN_NONSEEKABLE	(1 << 2)
390 #define FOPEN_CACHE_DIR		(1 << 3)
391 #define FOPEN_STREAM		(1 << 4)
392 #define FOPEN_NOFLUSH		(1 << 5)
393 #define FOPEN_PARALLEL_DIRECT_WRITES	(1 << 6)
394 #define FOPEN_PASSTHROUGH	(1 << 7)
395 
396 /**
397  * INIT request/reply flags
398  *
399  * FUSE_ASYNC_READ: asynchronous read requests
400  * FUSE_POSIX_LOCKS: remote locking for POSIX file locks
401  * FUSE_FILE_OPS: kernel sends file handle for fstat, etc... (not yet supported)
402  * FUSE_ATOMIC_O_TRUNC: handles the O_TRUNC open flag in the filesystem
403  * FUSE_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
404  * FUSE_BIG_WRITES: filesystem can handle write size larger than 4kB
405  * FUSE_DONT_MASK: don't apply umask to file mode on create operations
406  * FUSE_SPLICE_WRITE: kernel supports splice write on the device
407  * FUSE_SPLICE_MOVE: kernel supports splice move on the device
408  * FUSE_SPLICE_READ: kernel supports splice read on the device
409  * FUSE_FLOCK_LOCKS: remote locking for BSD style file locks
410  * FUSE_HAS_IOCTL_DIR: kernel supports ioctl on directories
411  * FUSE_AUTO_INVAL_DATA: automatically invalidate cached pages
412  * FUSE_DO_READDIRPLUS: do READDIRPLUS (READDIR+LOOKUP in one)
413  * FUSE_READDIRPLUS_AUTO: adaptive readdirplus
414  * FUSE_ASYNC_DIO: asynchronous direct I/O submission
415  * FUSE_WRITEBACK_CACHE: use writeback cache for buffered writes
416  * FUSE_NO_OPEN_SUPPORT: kernel supports zero-message opens
417  * FUSE_PARALLEL_DIROPS: allow parallel lookups and readdir
418  * FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on write/chown/trunc
419  * FUSE_POSIX_ACL: filesystem supports posix acls
420  * FUSE_ABORT_ERROR: reading the device after abort returns ECONNABORTED
421  * FUSE_MAX_PAGES: init_out.max_pages contains the max number of req pages
422  * FUSE_CACHE_SYMLINKS: cache READLINK responses
423  * FUSE_NO_OPENDIR_SUPPORT: kernel supports zero-message opendir
424  * FUSE_EXPLICIT_INVAL_DATA: only invalidate cached pages on explicit request
425  * FUSE_MAP_ALIGNMENT: init_out.map_alignment contains log2(byte alignment) for
426  *		       foffset and moffset fields in struct
427  *		       fuse_setupmapping_out and fuse_removemapping_one.
428  * FUSE_SUBMOUNTS: kernel supports auto-mounting directory submounts
429  * FUSE_HANDLE_KILLPRIV_V2: fs kills suid/sgid/cap on write/chown/trunc.
430  *			Upon write/truncate suid/sgid is only killed if caller
431  *			does not have CAP_FSETID. Additionally upon
432  *			write/truncate sgid is killed only if file has group
433  *			execute permission. (Same as Linux VFS behavior).
434  * FUSE_SETXATTR_EXT:	Server supports extended struct fuse_setxattr_in
435  * FUSE_INIT_EXT: extended fuse_init_in request
436  * FUSE_INIT_RESERVED: reserved, do not use
437  * FUSE_SECURITY_CTX:	add security context to create, mkdir, symlink, and
438  *			mknod
439  * FUSE_HAS_INODE_DAX:  use per inode DAX
440  * FUSE_CREATE_SUPP_GROUP: add supplementary group info to create, mkdir,
441  *			symlink and mknod (single group that matches parent)
442  * FUSE_HAS_EXPIRE_ONLY: kernel supports expiry-only entry invalidation
443  * FUSE_DIRECT_IO_ALLOW_MMAP: allow shared mmap in FOPEN_DIRECT_IO mode.
444  * FUSE_NO_EXPORT_SUPPORT: explicitly disable export support
445  * FUSE_HAS_RESEND: kernel supports resending pending requests, and the high bit
446  *		    of the request ID indicates resend requests
447  * FUSE_ALLOW_IDMAP: allow creation of idmapped mounts
448  * FUSE_OVER_IO_URING: Indicate that client supports io-uring
449  * FUSE_REQUEST_TIMEOUT: kernel supports timing out requests.
450  *			 init_out.request_timeout contains the timeout (in secs)
451  */
452 #define FUSE_ASYNC_READ		(1 << 0)
453 #define FUSE_POSIX_LOCKS	(1 << 1)
454 #define FUSE_FILE_OPS		(1 << 2)
455 #define FUSE_ATOMIC_O_TRUNC	(1 << 3)
456 #define FUSE_EXPORT_SUPPORT	(1 << 4)
457 #define FUSE_BIG_WRITES		(1 << 5)
458 #define FUSE_DONT_MASK		(1 << 6)
459 #define FUSE_SPLICE_WRITE	(1 << 7)
460 #define FUSE_SPLICE_MOVE	(1 << 8)
461 #define FUSE_SPLICE_READ	(1 << 9)
462 #define FUSE_FLOCK_LOCKS	(1 << 10)
463 #define FUSE_HAS_IOCTL_DIR	(1 << 11)
464 #define FUSE_AUTO_INVAL_DATA	(1 << 12)
465 #define FUSE_DO_READDIRPLUS	(1 << 13)
466 #define FUSE_READDIRPLUS_AUTO	(1 << 14)
467 #define FUSE_ASYNC_DIO		(1 << 15)
468 #define FUSE_WRITEBACK_CACHE	(1 << 16)
469 #define FUSE_NO_OPEN_SUPPORT	(1 << 17)
470 #define FUSE_PARALLEL_DIROPS    (1 << 18)
471 #define FUSE_HANDLE_KILLPRIV	(1 << 19)
472 #define FUSE_POSIX_ACL		(1 << 20)
473 #define FUSE_ABORT_ERROR	(1 << 21)
474 #define FUSE_MAX_PAGES		(1 << 22)
475 #define FUSE_CACHE_SYMLINKS	(1 << 23)
476 #define FUSE_NO_OPENDIR_SUPPORT (1 << 24)
477 #define FUSE_EXPLICIT_INVAL_DATA (1 << 25)
478 #define FUSE_MAP_ALIGNMENT	(1 << 26)
479 #define FUSE_SUBMOUNTS		(1 << 27)
480 #define FUSE_HANDLE_KILLPRIV_V2	(1 << 28)
481 #define FUSE_SETXATTR_EXT	(1 << 29)
482 #define FUSE_INIT_EXT		(1 << 30)
483 #define FUSE_INIT_RESERVED	(1 << 31)
484 /* bits 32..63 get shifted down 32 bits into the flags2 field */
485 #define FUSE_SECURITY_CTX	(1ULL << 32)
486 #define FUSE_HAS_INODE_DAX	(1ULL << 33)
487 #define FUSE_CREATE_SUPP_GROUP	(1ULL << 34)
488 #define FUSE_HAS_EXPIRE_ONLY	(1ULL << 35)
489 #define FUSE_DIRECT_IO_ALLOW_MMAP (1ULL << 36)
490 #define FUSE_PASSTHROUGH	(1ULL << 37)
491 #define FUSE_NO_EXPORT_SUPPORT	(1ULL << 38)
492 #define FUSE_HAS_RESEND		(1ULL << 39)
493 /* Obsolete alias for FUSE_DIRECT_IO_ALLOW_MMAP */
494 #define FUSE_DIRECT_IO_RELAX	FUSE_DIRECT_IO_ALLOW_MMAP
495 #define FUSE_ALLOW_IDMAP	(1ULL << 40)
496 #define FUSE_OVER_IO_URING	(1ULL << 41)
497 #define FUSE_REQUEST_TIMEOUT	(1ULL << 42)
498 
499 /**
500  * CUSE INIT request/reply flags
501  *
502  * CUSE_UNRESTRICTED_IOCTL:  use unrestricted ioctl
503  */
504 #define CUSE_UNRESTRICTED_IOCTL	(1 << 0)
505 
506 /**
507  * Release flags
508  */
509 #define FUSE_RELEASE_FLUSH	(1 << 0)
510 #define FUSE_RELEASE_FLOCK_UNLOCK	(1 << 1)
511 
512 /**
513  * Getattr flags
514  */
515 #define FUSE_GETATTR_FH		(1 << 0)
516 
517 /**
518  * Lock flags
519  */
520 #define FUSE_LK_FLOCK		(1 << 0)
521 
522 /**
523  * WRITE flags
524  *
525  * FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
526  * FUSE_WRITE_LOCKOWNER: lock_owner field is valid
527  * FUSE_WRITE_KILL_SUIDGID: kill suid and sgid bits
528  */
529 #define FUSE_WRITE_CACHE	(1 << 0)
530 #define FUSE_WRITE_LOCKOWNER	(1 << 1)
531 #define FUSE_WRITE_KILL_SUIDGID (1 << 2)
532 
533 /* Obsolete alias; this flag implies killing suid/sgid only. */
534 #define FUSE_WRITE_KILL_PRIV	FUSE_WRITE_KILL_SUIDGID
535 
536 /**
537  * Read flags
538  */
539 #define FUSE_READ_LOCKOWNER	(1 << 1)
540 
541 /**
542  * Ioctl flags
543  *
544  * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
545  * FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
546  * FUSE_IOCTL_RETRY: retry with new iovecs
547  * FUSE_IOCTL_32BIT: 32bit ioctl
548  * FUSE_IOCTL_DIR: is a directory
549  * FUSE_IOCTL_COMPAT_X32: x32 compat ioctl on 64bit machine (64bit time_t)
550  *
551  * FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
552  */
553 #define FUSE_IOCTL_COMPAT	(1 << 0)
554 #define FUSE_IOCTL_UNRESTRICTED	(1 << 1)
555 #define FUSE_IOCTL_RETRY	(1 << 2)
556 #define FUSE_IOCTL_32BIT	(1 << 3)
557 #define FUSE_IOCTL_DIR		(1 << 4)
558 #define FUSE_IOCTL_COMPAT_X32	(1 << 5)
559 
560 #define FUSE_IOCTL_MAX_IOV	256
561 
562 /**
563  * Poll flags
564  *
565  * FUSE_POLL_SCHEDULE_NOTIFY: request poll notify
566  */
567 #define FUSE_POLL_SCHEDULE_NOTIFY (1 << 0)
568 
569 /**
570  * Fsync flags
571  *
572  * FUSE_FSYNC_FDATASYNC: Sync data only, not metadata
573  */
574 #define FUSE_FSYNC_FDATASYNC	(1 << 0)
575 
576 /**
577  * fuse_attr flags
578  *
579  * FUSE_ATTR_SUBMOUNT: Object is a submount root
580  * FUSE_ATTR_DAX: Enable DAX for this file in per inode DAX mode
581  */
582 #define FUSE_ATTR_SUBMOUNT      (1 << 0)
583 #define FUSE_ATTR_DAX		(1 << 1)
584 
585 /**
586  * Open flags
587  * FUSE_OPEN_KILL_SUIDGID: Kill suid and sgid if executable
588  */
589 #define FUSE_OPEN_KILL_SUIDGID	(1 << 0)
590 
591 /**
592  * setxattr flags
593  * FUSE_SETXATTR_ACL_KILL_SGID: Clear SGID when system.posix_acl_access is set
594  */
595 #define FUSE_SETXATTR_ACL_KILL_SGID	(1 << 0)
596 
597 /**
598  * notify_inval_entry flags
599  * FUSE_EXPIRE_ONLY
600  */
601 #define FUSE_EXPIRE_ONLY		(1 << 0)
602 
603 /**
604  * extension type
605  * FUSE_MAX_NR_SECCTX: maximum value of &fuse_secctx_header.nr_secctx
606  * FUSE_EXT_GROUPS: &fuse_supp_groups extension
607  */
608 enum fuse_ext_type {
609 	/* Types 0..31 are reserved for fuse_secctx_header */
610 	FUSE_MAX_NR_SECCTX	= 31,
611 	FUSE_EXT_GROUPS		= 32,
612 };
613 
614 enum fuse_opcode {
615 	FUSE_LOOKUP		= 1,
616 	FUSE_FORGET		= 2,  /* no reply */
617 	FUSE_GETATTR		= 3,
618 	FUSE_SETATTR		= 4,
619 	FUSE_READLINK		= 5,
620 	FUSE_SYMLINK		= 6,
621 	FUSE_MKNOD		= 8,
622 	FUSE_MKDIR		= 9,
623 	FUSE_UNLINK		= 10,
624 	FUSE_RMDIR		= 11,
625 	FUSE_RENAME		= 12,
626 	FUSE_LINK		= 13,
627 	FUSE_OPEN		= 14,
628 	FUSE_READ		= 15,
629 	FUSE_WRITE		= 16,
630 	FUSE_STATFS		= 17,
631 	FUSE_RELEASE		= 18,
632 	FUSE_FSYNC		= 20,
633 	FUSE_SETXATTR		= 21,
634 	FUSE_GETXATTR		= 22,
635 	FUSE_LISTXATTR		= 23,
636 	FUSE_REMOVEXATTR	= 24,
637 	FUSE_FLUSH		= 25,
638 	FUSE_INIT		= 26,
639 	FUSE_OPENDIR		= 27,
640 	FUSE_READDIR		= 28,
641 	FUSE_RELEASEDIR		= 29,
642 	FUSE_FSYNCDIR		= 30,
643 	FUSE_GETLK		= 31,
644 	FUSE_SETLK		= 32,
645 	FUSE_SETLKW		= 33,
646 	FUSE_ACCESS		= 34,
647 	FUSE_CREATE		= 35,
648 	FUSE_INTERRUPT		= 36,
649 	FUSE_BMAP		= 37,
650 	FUSE_DESTROY		= 38,
651 	FUSE_IOCTL		= 39,
652 	FUSE_POLL		= 40,
653 	FUSE_NOTIFY_REPLY	= 41,
654 	FUSE_BATCH_FORGET	= 42,
655 	FUSE_FALLOCATE		= 43,
656 	FUSE_READDIRPLUS	= 44,
657 	FUSE_RENAME2		= 45,
658 	FUSE_LSEEK		= 46,
659 	FUSE_COPY_FILE_RANGE	= 47,
660 	FUSE_SETUPMAPPING	= 48,
661 	FUSE_REMOVEMAPPING	= 49,
662 	FUSE_SYNCFS		= 50,
663 	FUSE_TMPFILE		= 51,
664 	FUSE_STATX		= 52,
665 	FUSE_COPY_FILE_RANGE_64	= 53,
666 
667 	/* CUSE specific operations */
668 	CUSE_INIT		= 4096,
669 
670 	/* Reserved opcodes: helpful to detect structure endian-ness */
671 	CUSE_INIT_BSWAP_RESERVED	= 1048576,	/* CUSE_INIT << 8 */
672 	FUSE_INIT_BSWAP_RESERVED	= 436207616,	/* FUSE_INIT << 24 */
673 };
674 
675 enum fuse_notify_code {
676 	FUSE_NOTIFY_POLL   = 1,
677 	FUSE_NOTIFY_INVAL_INODE = 2,
678 	FUSE_NOTIFY_INVAL_ENTRY = 3,
679 	FUSE_NOTIFY_STORE = 4,
680 	FUSE_NOTIFY_RETRIEVE = 5,
681 	FUSE_NOTIFY_DELETE = 6,
682 	FUSE_NOTIFY_RESEND = 7,
683 	FUSE_NOTIFY_INC_EPOCH = 8,
684 	FUSE_NOTIFY_PRUNE = 9,
685 };
686 
687 /* The read buffer is required to be at least 8k, but may be much larger */
688 #define FUSE_MIN_READ_BUFFER 8192
689 
690 #define FUSE_COMPAT_ENTRY_OUT_SIZE 120
691 
692 struct fuse_entry_out {
693 	uint64_t	nodeid;		/* Inode ID */
694 	uint64_t	generation;	/* Inode generation: nodeid:gen must
695 					   be unique for the fs's lifetime */
696 	uint64_t	entry_valid;	/* Cache timeout for the name */
697 	uint64_t	attr_valid;	/* Cache timeout for the attributes */
698 	uint32_t	entry_valid_nsec;
699 	uint32_t	attr_valid_nsec;
700 	struct fuse_attr attr;
701 };
702 
703 struct fuse_forget_in {
704 	uint64_t	nlookup;
705 };
706 
707 struct fuse_forget_one {
708 	uint64_t	nodeid;
709 	uint64_t	nlookup;
710 };
711 
712 struct fuse_batch_forget_in {
713 	uint32_t	count;
714 	uint32_t	dummy;
715 };
716 
717 struct fuse_getattr_in {
718 	uint32_t	getattr_flags;
719 	uint32_t	dummy;
720 	uint64_t	fh;
721 };
722 
723 #define FUSE_COMPAT_ATTR_OUT_SIZE 96
724 
725 struct fuse_attr_out {
726 	uint64_t	attr_valid;	/* Cache timeout for the attributes */
727 	uint32_t	attr_valid_nsec;
728 	uint32_t	dummy;
729 	struct fuse_attr attr;
730 };
731 
732 struct fuse_statx_in {
733 	uint32_t	getattr_flags;
734 	uint32_t	reserved;
735 	uint64_t	fh;
736 	uint32_t	sx_flags;
737 	uint32_t	sx_mask;
738 };
739 
740 struct fuse_statx_out {
741 	uint64_t	attr_valid;	/* Cache timeout for the attributes */
742 	uint32_t	attr_valid_nsec;
743 	uint32_t	flags;
744 	uint64_t	spare[2];
745 	struct fuse_statx stat;
746 };
747 
748 #define FUSE_COMPAT_MKNOD_IN_SIZE 8
749 
750 struct fuse_mknod_in {
751 	uint32_t	mode;
752 	uint32_t	rdev;
753 	uint32_t	umask;
754 	uint32_t	padding;
755 };
756 
757 struct fuse_mkdir_in {
758 	uint32_t	mode;
759 	uint32_t	umask;
760 };
761 
762 struct fuse_rename_in {
763 	uint64_t	newdir;
764 };
765 
766 struct fuse_rename2_in {
767 	uint64_t	newdir;
768 	uint32_t	flags;
769 	uint32_t	padding;
770 };
771 
772 struct fuse_link_in {
773 	uint64_t	oldnodeid;
774 };
775 
776 struct fuse_setattr_in {
777 	uint32_t	valid;
778 	uint32_t	padding;
779 	uint64_t	fh;
780 	uint64_t	size;
781 	uint64_t	lock_owner;
782 	uint64_t	atime;
783 	uint64_t	mtime;
784 	uint64_t	ctime;
785 	uint32_t	atimensec;
786 	uint32_t	mtimensec;
787 	uint32_t	ctimensec;
788 	uint32_t	mode;
789 	uint32_t	unused4;
790 	uint32_t	uid;
791 	uint32_t	gid;
792 	uint32_t	unused5;
793 };
794 
795 struct fuse_open_in {
796 	uint32_t	flags;
797 	uint32_t	open_flags;	/* FUSE_OPEN_... */
798 };
799 
800 struct fuse_create_in {
801 	uint32_t	flags;
802 	uint32_t	mode;
803 	uint32_t	umask;
804 	uint32_t	open_flags;	/* FUSE_OPEN_... */
805 };
806 
807 struct fuse_open_out {
808 	uint64_t	fh;
809 	uint32_t	open_flags;
810 	int32_t		backing_id;
811 };
812 
813 struct fuse_release_in {
814 	uint64_t	fh;
815 	uint32_t	flags;
816 	uint32_t	release_flags;
817 	uint64_t	lock_owner;
818 };
819 
820 struct fuse_flush_in {
821 	uint64_t	fh;
822 	uint32_t	unused;
823 	uint32_t	padding;
824 	uint64_t	lock_owner;
825 };
826 
827 struct fuse_read_in {
828 	uint64_t	fh;
829 	uint64_t	offset;
830 	uint32_t	size;
831 	uint32_t	read_flags;
832 	uint64_t	lock_owner;
833 	uint32_t	flags;
834 	uint32_t	padding;
835 };
836 
837 #define FUSE_COMPAT_WRITE_IN_SIZE 24
838 
839 struct fuse_write_in {
840 	uint64_t	fh;
841 	uint64_t	offset;
842 	uint32_t	size;
843 	uint32_t	write_flags;
844 	uint64_t	lock_owner;
845 	uint32_t	flags;
846 	uint32_t	padding;
847 };
848 
849 struct fuse_write_out {
850 	uint32_t	size;
851 	uint32_t	padding;
852 };
853 
854 #define FUSE_COMPAT_STATFS_SIZE 48
855 
856 struct fuse_statfs_out {
857 	struct fuse_kstatfs st;
858 };
859 
860 struct fuse_fsync_in {
861 	uint64_t	fh;
862 	uint32_t	fsync_flags;
863 	uint32_t	padding;
864 };
865 
866 #define FUSE_COMPAT_SETXATTR_IN_SIZE 8
867 
868 struct fuse_setxattr_in {
869 	uint32_t	size;
870 	uint32_t	flags;
871 	uint32_t	setxattr_flags;
872 	uint32_t	padding;
873 };
874 
875 struct fuse_getxattr_in {
876 	uint32_t	size;
877 	uint32_t	padding;
878 };
879 
880 struct fuse_getxattr_out {
881 	uint32_t	size;
882 	uint32_t	padding;
883 };
884 
885 struct fuse_lk_in {
886 	uint64_t	fh;
887 	uint64_t	owner;
888 	struct fuse_file_lock lk;
889 	uint32_t	lk_flags;
890 	uint32_t	padding;
891 };
892 
893 struct fuse_lk_out {
894 	struct fuse_file_lock lk;
895 };
896 
897 struct fuse_access_in {
898 	uint32_t	mask;
899 	uint32_t	padding;
900 };
901 
902 struct fuse_init_in {
903 	uint32_t	major;
904 	uint32_t	minor;
905 	uint32_t	max_readahead;
906 	uint32_t	flags;
907 	uint32_t	flags2;
908 	uint32_t	unused[11];
909 };
910 
911 #define FUSE_COMPAT_INIT_OUT_SIZE 8
912 #define FUSE_COMPAT_22_INIT_OUT_SIZE 24
913 
914 struct fuse_init_out {
915 	uint32_t	major;
916 	uint32_t	minor;
917 	uint32_t	max_readahead;
918 	uint32_t	flags;
919 	uint16_t	max_background;
920 	uint16_t	congestion_threshold;
921 	uint32_t	max_write;
922 	uint32_t	time_gran;
923 	uint16_t	max_pages;
924 	uint16_t	map_alignment;
925 	uint32_t	flags2;
926 	uint32_t	max_stack_depth;
927 	uint16_t	request_timeout;
928 	uint16_t	unused[11];
929 };
930 
931 #define CUSE_INIT_INFO_MAX 4096
932 
933 struct cuse_init_in {
934 	uint32_t	major;
935 	uint32_t	minor;
936 	uint32_t	unused;
937 	uint32_t	flags;
938 };
939 
940 struct cuse_init_out {
941 	uint32_t	major;
942 	uint32_t	minor;
943 	uint32_t	unused;
944 	uint32_t	flags;
945 	uint32_t	max_read;
946 	uint32_t	max_write;
947 	uint32_t	dev_major;		/* chardev major */
948 	uint32_t	dev_minor;		/* chardev minor */
949 	uint32_t	spare[10];
950 };
951 
952 struct fuse_interrupt_in {
953 	uint64_t	unique;
954 };
955 
956 struct fuse_bmap_in {
957 	uint64_t	block;
958 	uint32_t	blocksize;
959 	uint32_t	padding;
960 };
961 
962 struct fuse_bmap_out {
963 	uint64_t	block;
964 };
965 
966 struct fuse_ioctl_in {
967 	uint64_t	fh;
968 	uint32_t	flags;
969 	uint32_t	cmd;
970 	uint64_t	arg;
971 	uint32_t	in_size;
972 	uint32_t	out_size;
973 };
974 
975 struct fuse_ioctl_iovec {
976 	uint64_t	base;
977 	uint64_t	len;
978 };
979 
980 struct fuse_ioctl_out {
981 	int32_t		result;
982 	uint32_t	flags;
983 	uint32_t	in_iovs;
984 	uint32_t	out_iovs;
985 };
986 
987 struct fuse_poll_in {
988 	uint64_t	fh;
989 	uint64_t	kh;
990 	uint32_t	flags;
991 	uint32_t	events;
992 };
993 
994 struct fuse_poll_out {
995 	uint32_t	revents;
996 	uint32_t	padding;
997 };
998 
999 struct fuse_notify_poll_wakeup_out {
1000 	uint64_t	kh;
1001 };
1002 
1003 struct fuse_fallocate_in {
1004 	uint64_t	fh;
1005 	uint64_t	offset;
1006 	uint64_t	length;
1007 	uint32_t	mode;
1008 	uint32_t	padding;
1009 };
1010 
1011 /**
1012  * FUSE request unique ID flag
1013  *
1014  * Indicates whether this is a resend request. The receiver should handle this
1015  * request accordingly.
1016  */
1017 #define FUSE_UNIQUE_RESEND (1ULL << 63)
1018 
1019 /**
1020  * This value will be set by the kernel to
1021  * (struct fuse_in_header).{uid,gid} fields in
1022  * case when:
1023  * - fuse daemon enabled FUSE_ALLOW_IDMAP
1024  * - idmapping information is not available and uid/gid
1025  *   can not be mapped in accordance with an idmapping.
1026  *
1027  * Note: an idmapping information always available
1028  * for inode creation operations like:
1029  * FUSE_MKNOD, FUSE_SYMLINK, FUSE_MKDIR, FUSE_TMPFILE,
1030  * FUSE_CREATE and FUSE_RENAME2 (with RENAME_WHITEOUT).
1031  */
1032 #define FUSE_INVALID_UIDGID ((uint32_t)(-1))
1033 
1034 struct fuse_in_header {
1035 	uint32_t	len;
1036 	uint32_t	opcode;
1037 	uint64_t	unique;
1038 	uint64_t	nodeid;
1039 	uint32_t	uid;
1040 	uint32_t	gid;
1041 	uint32_t	pid;
1042 	uint16_t	total_extlen; /* length of extensions in 8byte units */
1043 	uint16_t	padding;
1044 };
1045 
1046 struct fuse_out_header {
1047 	uint32_t	len;
1048 	int32_t		error;
1049 	uint64_t	unique;
1050 };
1051 
1052 struct fuse_dirent {
1053 	uint64_t	ino;
1054 	uint64_t	off;
1055 	uint32_t	namelen;
1056 	uint32_t	type;
1057 	char name[];
1058 };
1059 
1060 /* Align variable length records to 64bit boundary */
1061 #define FUSE_REC_ALIGN(x) \
1062 	(((x) + sizeof(uint64_t) - 1) & ~(sizeof(uint64_t) - 1))
1063 
1064 #define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
1065 #define FUSE_DIRENT_ALIGN(x) FUSE_REC_ALIGN(x)
1066 #define FUSE_DIRENT_SIZE(d) \
1067 	FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)
1068 
1069 struct fuse_direntplus {
1070 	struct fuse_entry_out entry_out;
1071 	struct fuse_dirent dirent;
1072 };
1073 
1074 #define FUSE_NAME_OFFSET_DIRENTPLUS \
1075 	offsetof(struct fuse_direntplus, dirent.name)
1076 #define FUSE_DIRENTPLUS_SIZE(d) \
1077 	FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET_DIRENTPLUS + (d)->dirent.namelen)
1078 
1079 struct fuse_notify_inval_inode_out {
1080 	uint64_t	ino;
1081 	int64_t		off;
1082 	int64_t		len;
1083 };
1084 
1085 struct fuse_notify_inval_entry_out {
1086 	uint64_t	parent;
1087 	uint32_t	namelen;
1088 	uint32_t	flags;
1089 };
1090 
1091 struct fuse_notify_delete_out {
1092 	uint64_t	parent;
1093 	uint64_t	child;
1094 	uint32_t	namelen;
1095 	uint32_t	padding;
1096 };
1097 
1098 struct fuse_notify_store_out {
1099 	uint64_t	nodeid;
1100 	uint64_t	offset;
1101 	uint32_t	size;
1102 	uint32_t	padding;
1103 };
1104 
1105 struct fuse_notify_retrieve_out {
1106 	uint64_t	notify_unique;
1107 	uint64_t	nodeid;
1108 	uint64_t	offset;
1109 	uint32_t	size;
1110 	uint32_t	padding;
1111 };
1112 
1113 /* Matches the size of fuse_write_in */
1114 struct fuse_notify_retrieve_in {
1115 	uint64_t	dummy1;
1116 	uint64_t	offset;
1117 	uint32_t	size;
1118 	uint32_t	dummy2;
1119 	uint64_t	dummy3;
1120 	uint64_t	dummy4;
1121 };
1122 
1123 struct fuse_notify_prune_out {
1124 	uint32_t	count;
1125 	uint32_t	padding;
1126 	uint64_t	spare;
1127 };
1128 
1129 struct fuse_backing_map {
1130 	int32_t		fd;
1131 	uint32_t	flags;
1132 	uint64_t	padding;
1133 };
1134 
1135 /* Device ioctls: */
1136 #define FUSE_DEV_IOC_MAGIC		229
1137 #define FUSE_DEV_IOC_CLONE		_IOR(FUSE_DEV_IOC_MAGIC, 0, uint32_t)
1138 #define FUSE_DEV_IOC_BACKING_OPEN	_IOW(FUSE_DEV_IOC_MAGIC, 1, \
1139 					     struct fuse_backing_map)
1140 #define FUSE_DEV_IOC_BACKING_CLOSE	_IOW(FUSE_DEV_IOC_MAGIC, 2, uint32_t)
1141 #define FUSE_DEV_IOC_SYNC_INIT		_IO(FUSE_DEV_IOC_MAGIC, 3)
1142 
1143 struct fuse_lseek_in {
1144 	uint64_t	fh;
1145 	uint64_t	offset;
1146 	uint32_t	whence;
1147 	uint32_t	padding;
1148 };
1149 
1150 struct fuse_lseek_out {
1151 	uint64_t	offset;
1152 };
1153 
1154 struct fuse_copy_file_range_in {
1155 	uint64_t	fh_in;
1156 	uint64_t	off_in;
1157 	uint64_t	nodeid_out;
1158 	uint64_t	fh_out;
1159 	uint64_t	off_out;
1160 	uint64_t	len;
1161 	uint64_t	flags;
1162 };
1163 
1164 /* For FUSE_COPY_FILE_RANGE_64 */
1165 struct fuse_copy_file_range_out {
1166 	uint64_t	bytes_copied;
1167 };
1168 
1169 #define FUSE_SETUPMAPPING_FLAG_WRITE (1ull << 0)
1170 #define FUSE_SETUPMAPPING_FLAG_READ (1ull << 1)
1171 struct fuse_setupmapping_in {
1172 	/* An already open handle */
1173 	uint64_t	fh;
1174 	/* Offset into the file to start the mapping */
1175 	uint64_t	foffset;
1176 	/* Length of mapping required */
1177 	uint64_t	len;
1178 	/* Flags, FUSE_SETUPMAPPING_FLAG_* */
1179 	uint64_t	flags;
1180 	/* Offset in Memory Window */
1181 	uint64_t	moffset;
1182 };
1183 
1184 struct fuse_removemapping_in {
1185 	/* number of fuse_removemapping_one follows */
1186 	uint32_t        count;
1187 };
1188 
1189 struct fuse_removemapping_one {
1190 	/* Offset into the dax window start the unmapping */
1191 	uint64_t        moffset;
1192 	/* Length of mapping required */
1193 	uint64_t	len;
1194 };
1195 
1196 #define FUSE_REMOVEMAPPING_MAX_ENTRY   \
1197 		(PAGE_SIZE / sizeof(struct fuse_removemapping_one))
1198 
1199 struct fuse_syncfs_in {
1200 	uint64_t	padding;
1201 };
1202 
1203 /*
1204  * For each security context, send fuse_secctx with size of security context
1205  * fuse_secctx will be followed by security context name and this in turn
1206  * will be followed by actual context label.
1207  * fuse_secctx, name, context
1208  */
1209 struct fuse_secctx {
1210 	uint32_t	size;
1211 	uint32_t	padding;
1212 };
1213 
1214 /*
1215  * Contains the information about how many fuse_secctx structures are being
1216  * sent and what's the total size of all security contexts (including
1217  * size of fuse_secctx_header).
1218  *
1219  */
1220 struct fuse_secctx_header {
1221 	uint32_t	size;
1222 	uint32_t	nr_secctx;
1223 };
1224 
1225 /**
1226  * struct fuse_ext_header - extension header
1227  * @size: total size of this extension including this header
1228  * @type: type of extension
1229  *
1230  * This is made compatible with fuse_secctx_header by using type values >
1231  * FUSE_MAX_NR_SECCTX
1232  */
1233 struct fuse_ext_header {
1234 	uint32_t	size;
1235 	uint32_t	type;
1236 };
1237 
1238 /**
1239  * struct fuse_supp_groups - Supplementary group extension
1240  * @nr_groups: number of supplementary groups
1241  * @groups: flexible array of group IDs
1242  */
1243 struct fuse_supp_groups {
1244 	uint32_t	nr_groups;
1245 	uint32_t	groups[];
1246 };
1247 
1248 /**
1249  * Size of the ring buffer header
1250  */
1251 #define FUSE_URING_IN_OUT_HEADER_SZ 128
1252 #define FUSE_URING_OP_IN_OUT_SZ 128
1253 
1254 /* Used as part of the fuse_uring_req_header */
1255 struct fuse_uring_ent_in_out {
1256 	uint64_t flags;
1257 
1258 	/*
1259 	 * commit ID to be used in a reply to a ring request (see also
1260 	 * struct fuse_uring_cmd_req)
1261 	 */
1262 	uint64_t commit_id;
1263 
1264 	/* size of user payload buffer */
1265 	uint32_t payload_sz;
1266 	uint32_t padding;
1267 
1268 	uint64_t reserved;
1269 };
1270 
1271 /**
1272  * Header for all fuse-io-uring requests
1273  */
1274 struct fuse_uring_req_header {
1275 	/* struct fuse_in_header / struct fuse_out_header */
1276 	char in_out[FUSE_URING_IN_OUT_HEADER_SZ];
1277 
1278 	/* per op code header */
1279 	char op_in[FUSE_URING_OP_IN_OUT_SZ];
1280 
1281 	struct fuse_uring_ent_in_out ring_ent_in_out;
1282 };
1283 
1284 /**
1285  * sqe commands to the kernel
1286  */
1287 enum fuse_uring_cmd {
1288 	FUSE_IO_URING_CMD_INVALID = 0,
1289 
1290 	/* register the request buffer and fetch a fuse request */
1291 	FUSE_IO_URING_CMD_REGISTER = 1,
1292 
1293 	/* commit fuse request result and fetch next request */
1294 	FUSE_IO_URING_CMD_COMMIT_AND_FETCH = 2,
1295 };
1296 
1297 /**
1298  * In the 80B command area of the SQE.
1299  */
1300 struct fuse_uring_cmd_req {
1301 	uint64_t flags;
1302 
1303 	/* entry identifier for commits */
1304 	uint64_t commit_id;
1305 
1306 	/* queue the command is for (queue index) */
1307 	uint16_t qid;
1308 	uint8_t padding[6];
1309 };
1310 
1311 #endif /* _LINUX_FUSE_H */
1312