xref: /openbmc/qemu/include/standard-headers/linux/fuse.h (revision 050b3d3630051fc4637d6c5078033680ec7c5f5e)
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 #include <stdint.h>
249 
250 /*
251  * Version negotiation:
252  *
253  * Both the kernel and userspace send the version they support in the
254  * INIT request and reply respectively.
255  *
256  * If the major versions match then both shall use the smallest
257  * of the two minor versions for communication.
258  *
259  * If the kernel supports a larger major version, then userspace shall
260  * reply with the major version it supports, ignore the rest of the
261  * INIT message and expect a new INIT message from the kernel with a
262  * matching major version.
263  *
264  * If the library supports a larger major version, then it shall fall
265  * back to the major protocol version sent by the kernel for
266  * communication and reply with that major version (and an arbitrary
267  * supported minor version).
268  */
269 
270 /** Version number of this interface */
271 #define FUSE_KERNEL_VERSION 7
272 
273 /** Minor version number of this interface */
274 #define FUSE_KERNEL_MINOR_VERSION 45
275 
276 /** The node ID of the root inode */
277 #define FUSE_ROOT_ID 1
278 
279 /* Make sure all structures are padded to 64bit boundary, so 32bit
280    userspace works under 64bit kernels */
281 
282 struct fuse_attr {
283 	uint64_t	ino;
284 	uint64_t	size;
285 	uint64_t	blocks;
286 	uint64_t	atime;
287 	uint64_t	mtime;
288 	uint64_t	ctime;
289 	uint32_t	atimensec;
290 	uint32_t	mtimensec;
291 	uint32_t	ctimensec;
292 	uint32_t	mode;
293 	uint32_t	nlink;
294 	uint32_t	uid;
295 	uint32_t	gid;
296 	uint32_t	rdev;
297 	uint32_t	blksize;
298 	uint32_t	flags;
299 };
300 
301 /*
302  * The following structures are bit-for-bit compatible with the statx(2) ABI in
303  * Linux.
304  */
305 struct fuse_sx_time {
306 	int64_t		tv_sec;
307 	uint32_t	tv_nsec;
308 	int32_t		__reserved;
309 };
310 
311 struct fuse_statx {
312 	uint32_t	mask;
313 	uint32_t	blksize;
314 	uint64_t	attributes;
315 	uint32_t	nlink;
316 	uint32_t	uid;
317 	uint32_t	gid;
318 	uint16_t	mode;
319 	uint16_t	__spare0[1];
320 	uint64_t	ino;
321 	uint64_t	size;
322 	uint64_t	blocks;
323 	uint64_t	attributes_mask;
324 	struct fuse_sx_time	atime;
325 	struct fuse_sx_time	btime;
326 	struct fuse_sx_time	ctime;
327 	struct fuse_sx_time	mtime;
328 	uint32_t	rdev_major;
329 	uint32_t	rdev_minor;
330 	uint32_t	dev_major;
331 	uint32_t	dev_minor;
332 	uint64_t	__spare2[14];
333 };
334 
335 struct fuse_kstatfs {
336 	uint64_t	blocks;
337 	uint64_t	bfree;
338 	uint64_t	bavail;
339 	uint64_t	files;
340 	uint64_t	ffree;
341 	uint32_t	bsize;
342 	uint32_t	namelen;
343 	uint32_t	frsize;
344 	uint32_t	padding;
345 	uint32_t	spare[6];
346 };
347 
348 struct fuse_file_lock {
349 	uint64_t	start;
350 	uint64_t	end;
351 	uint32_t	type;
352 	uint32_t	pid; /* tgid */
353 };
354 
355 /**
356  * Bitmasks for fuse_setattr_in.valid
357  */
358 #define FATTR_MODE	(1 << 0)
359 #define FATTR_UID	(1 << 1)
360 #define FATTR_GID	(1 << 2)
361 #define FATTR_SIZE	(1 << 3)
362 #define FATTR_ATIME	(1 << 4)
363 #define FATTR_MTIME	(1 << 5)
364 #define FATTR_FH	(1 << 6)
365 #define FATTR_ATIME_NOW	(1 << 7)
366 #define FATTR_MTIME_NOW	(1 << 8)
367 #define FATTR_LOCKOWNER	(1 << 9)
368 #define FATTR_CTIME	(1 << 10)
369 #define FATTR_KILL_SUIDGID	(1 << 11)
370 
371 /**
372  * Flags returned by the OPEN request
373  *
374  * FOPEN_DIRECT_IO: bypass page cache for this open file
375  * FOPEN_KEEP_CACHE: don't invalidate the data cache on open
376  * FOPEN_NONSEEKABLE: the file is not seekable
377  * FOPEN_CACHE_DIR: allow caching this directory
378  * FOPEN_STREAM: the file is stream-like (no file position at all)
379  * FOPEN_NOFLUSH: don't flush data cache on close (unless FUSE_WRITEBACK_CACHE)
380  * FOPEN_PARALLEL_DIRECT_WRITES: Allow concurrent direct writes on the same inode
381  * FOPEN_PASSTHROUGH: passthrough read/write io for this open file
382  */
383 #define FOPEN_DIRECT_IO		(1 << 0)
384 #define FOPEN_KEEP_CACHE	(1 << 1)
385 #define FOPEN_NONSEEKABLE	(1 << 2)
386 #define FOPEN_CACHE_DIR		(1 << 3)
387 #define FOPEN_STREAM		(1 << 4)
388 #define FOPEN_NOFLUSH		(1 << 5)
389 #define FOPEN_PARALLEL_DIRECT_WRITES	(1 << 6)
390 #define FOPEN_PASSTHROUGH	(1 << 7)
391 
392 /**
393  * INIT request/reply flags
394  *
395  * FUSE_ASYNC_READ: asynchronous read requests
396  * FUSE_POSIX_LOCKS: remote locking for POSIX file locks
397  * FUSE_FILE_OPS: kernel sends file handle for fstat, etc... (not yet supported)
398  * FUSE_ATOMIC_O_TRUNC: handles the O_TRUNC open flag in the filesystem
399  * FUSE_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
400  * FUSE_BIG_WRITES: filesystem can handle write size larger than 4kB
401  * FUSE_DONT_MASK: don't apply umask to file mode on create operations
402  * FUSE_SPLICE_WRITE: kernel supports splice write on the device
403  * FUSE_SPLICE_MOVE: kernel supports splice move on the device
404  * FUSE_SPLICE_READ: kernel supports splice read on the device
405  * FUSE_FLOCK_LOCKS: remote locking for BSD style file locks
406  * FUSE_HAS_IOCTL_DIR: kernel supports ioctl on directories
407  * FUSE_AUTO_INVAL_DATA: automatically invalidate cached pages
408  * FUSE_DO_READDIRPLUS: do READDIRPLUS (READDIR+LOOKUP in one)
409  * FUSE_READDIRPLUS_AUTO: adaptive readdirplus
410  * FUSE_ASYNC_DIO: asynchronous direct I/O submission
411  * FUSE_WRITEBACK_CACHE: use writeback cache for buffered writes
412  * FUSE_NO_OPEN_SUPPORT: kernel supports zero-message opens
413  * FUSE_PARALLEL_DIROPS: allow parallel lookups and readdir
414  * FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on write/chown/trunc
415  * FUSE_POSIX_ACL: filesystem supports posix acls
416  * FUSE_ABORT_ERROR: reading the device after abort returns ECONNABORTED
417  * FUSE_MAX_PAGES: init_out.max_pages contains the max number of req pages
418  * FUSE_CACHE_SYMLINKS: cache READLINK responses
419  * FUSE_NO_OPENDIR_SUPPORT: kernel supports zero-message opendir
420  * FUSE_EXPLICIT_INVAL_DATA: only invalidate cached pages on explicit request
421  * FUSE_MAP_ALIGNMENT: init_out.map_alignment contains log2(byte alignment) for
422  *		       foffset and moffset fields in struct
423  *		       fuse_setupmapping_out and fuse_removemapping_one.
424  * FUSE_SUBMOUNTS: kernel supports auto-mounting directory submounts
425  * FUSE_HANDLE_KILLPRIV_V2: fs kills suid/sgid/cap on write/chown/trunc.
426  *			Upon write/truncate suid/sgid is only killed if caller
427  *			does not have CAP_FSETID. Additionally upon
428  *			write/truncate sgid is killed only if file has group
429  *			execute permission. (Same as Linux VFS behavior).
430  * FUSE_SETXATTR_EXT:	Server supports extended struct fuse_setxattr_in
431  * FUSE_INIT_EXT: extended fuse_init_in request
432  * FUSE_INIT_RESERVED: reserved, do not use
433  * FUSE_SECURITY_CTX:	add security context to create, mkdir, symlink, and
434  *			mknod
435  * FUSE_HAS_INODE_DAX:  use per inode DAX
436  * FUSE_CREATE_SUPP_GROUP: add supplementary group info to create, mkdir,
437  *			symlink and mknod (single group that matches parent)
438  * FUSE_HAS_EXPIRE_ONLY: kernel supports expiry-only entry invalidation
439  * FUSE_DIRECT_IO_ALLOW_MMAP: allow shared mmap in FOPEN_DIRECT_IO mode.
440  * FUSE_NO_EXPORT_SUPPORT: explicitly disable export support
441  * FUSE_HAS_RESEND: kernel supports resending pending requests, and the high bit
442  *		    of the request ID indicates resend requests
443  * FUSE_ALLOW_IDMAP: allow creation of idmapped mounts
444  * FUSE_OVER_IO_URING: Indicate that client supports io-uring
445  * FUSE_REQUEST_TIMEOUT: kernel supports timing out requests.
446  *			 init_out.request_timeout contains the timeout (in secs)
447  */
448 #define FUSE_ASYNC_READ		(1 << 0)
449 #define FUSE_POSIX_LOCKS	(1 << 1)
450 #define FUSE_FILE_OPS		(1 << 2)
451 #define FUSE_ATOMIC_O_TRUNC	(1 << 3)
452 #define FUSE_EXPORT_SUPPORT	(1 << 4)
453 #define FUSE_BIG_WRITES		(1 << 5)
454 #define FUSE_DONT_MASK		(1 << 6)
455 #define FUSE_SPLICE_WRITE	(1 << 7)
456 #define FUSE_SPLICE_MOVE	(1 << 8)
457 #define FUSE_SPLICE_READ	(1 << 9)
458 #define FUSE_FLOCK_LOCKS	(1 << 10)
459 #define FUSE_HAS_IOCTL_DIR	(1 << 11)
460 #define FUSE_AUTO_INVAL_DATA	(1 << 12)
461 #define FUSE_DO_READDIRPLUS	(1 << 13)
462 #define FUSE_READDIRPLUS_AUTO	(1 << 14)
463 #define FUSE_ASYNC_DIO		(1 << 15)
464 #define FUSE_WRITEBACK_CACHE	(1 << 16)
465 #define FUSE_NO_OPEN_SUPPORT	(1 << 17)
466 #define FUSE_PARALLEL_DIROPS    (1 << 18)
467 #define FUSE_HANDLE_KILLPRIV	(1 << 19)
468 #define FUSE_POSIX_ACL		(1 << 20)
469 #define FUSE_ABORT_ERROR	(1 << 21)
470 #define FUSE_MAX_PAGES		(1 << 22)
471 #define FUSE_CACHE_SYMLINKS	(1 << 23)
472 #define FUSE_NO_OPENDIR_SUPPORT (1 << 24)
473 #define FUSE_EXPLICIT_INVAL_DATA (1 << 25)
474 #define FUSE_MAP_ALIGNMENT	(1 << 26)
475 #define FUSE_SUBMOUNTS		(1 << 27)
476 #define FUSE_HANDLE_KILLPRIV_V2	(1 << 28)
477 #define FUSE_SETXATTR_EXT	(1 << 29)
478 #define FUSE_INIT_EXT		(1 << 30)
479 #define FUSE_INIT_RESERVED	(1 << 31)
480 /* bits 32..63 get shifted down 32 bits into the flags2 field */
481 #define FUSE_SECURITY_CTX	(1ULL << 32)
482 #define FUSE_HAS_INODE_DAX	(1ULL << 33)
483 #define FUSE_CREATE_SUPP_GROUP	(1ULL << 34)
484 #define FUSE_HAS_EXPIRE_ONLY	(1ULL << 35)
485 #define FUSE_DIRECT_IO_ALLOW_MMAP (1ULL << 36)
486 #define FUSE_PASSTHROUGH	(1ULL << 37)
487 #define FUSE_NO_EXPORT_SUPPORT	(1ULL << 38)
488 #define FUSE_HAS_RESEND		(1ULL << 39)
489 /* Obsolete alias for FUSE_DIRECT_IO_ALLOW_MMAP */
490 #define FUSE_DIRECT_IO_RELAX	FUSE_DIRECT_IO_ALLOW_MMAP
491 #define FUSE_ALLOW_IDMAP	(1ULL << 40)
492 #define FUSE_OVER_IO_URING	(1ULL << 41)
493 #define FUSE_REQUEST_TIMEOUT	(1ULL << 42)
494 
495 /**
496  * CUSE INIT request/reply flags
497  *
498  * CUSE_UNRESTRICTED_IOCTL:  use unrestricted ioctl
499  */
500 #define CUSE_UNRESTRICTED_IOCTL	(1 << 0)
501 
502 /**
503  * Release flags
504  */
505 #define FUSE_RELEASE_FLUSH	(1 << 0)
506 #define FUSE_RELEASE_FLOCK_UNLOCK	(1 << 1)
507 
508 /**
509  * Getattr flags
510  */
511 #define FUSE_GETATTR_FH		(1 << 0)
512 
513 /**
514  * Lock flags
515  */
516 #define FUSE_LK_FLOCK		(1 << 0)
517 
518 /**
519  * WRITE flags
520  *
521  * FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
522  * FUSE_WRITE_LOCKOWNER: lock_owner field is valid
523  * FUSE_WRITE_KILL_SUIDGID: kill suid and sgid bits
524  */
525 #define FUSE_WRITE_CACHE	(1 << 0)
526 #define FUSE_WRITE_LOCKOWNER	(1 << 1)
527 #define FUSE_WRITE_KILL_SUIDGID (1 << 2)
528 
529 /* Obsolete alias; this flag implies killing suid/sgid only. */
530 #define FUSE_WRITE_KILL_PRIV	FUSE_WRITE_KILL_SUIDGID
531 
532 /**
533  * Read flags
534  */
535 #define FUSE_READ_LOCKOWNER	(1 << 1)
536 
537 /**
538  * Ioctl flags
539  *
540  * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
541  * FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
542  * FUSE_IOCTL_RETRY: retry with new iovecs
543  * FUSE_IOCTL_32BIT: 32bit ioctl
544  * FUSE_IOCTL_DIR: is a directory
545  * FUSE_IOCTL_COMPAT_X32: x32 compat ioctl on 64bit machine (64bit time_t)
546  *
547  * FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
548  */
549 #define FUSE_IOCTL_COMPAT	(1 << 0)
550 #define FUSE_IOCTL_UNRESTRICTED	(1 << 1)
551 #define FUSE_IOCTL_RETRY	(1 << 2)
552 #define FUSE_IOCTL_32BIT	(1 << 3)
553 #define FUSE_IOCTL_DIR		(1 << 4)
554 #define FUSE_IOCTL_COMPAT_X32	(1 << 5)
555 
556 #define FUSE_IOCTL_MAX_IOV	256
557 
558 /**
559  * Poll flags
560  *
561  * FUSE_POLL_SCHEDULE_NOTIFY: request poll notify
562  */
563 #define FUSE_POLL_SCHEDULE_NOTIFY (1 << 0)
564 
565 /**
566  * Fsync flags
567  *
568  * FUSE_FSYNC_FDATASYNC: Sync data only, not metadata
569  */
570 #define FUSE_FSYNC_FDATASYNC	(1 << 0)
571 
572 /**
573  * fuse_attr flags
574  *
575  * FUSE_ATTR_SUBMOUNT: Object is a submount root
576  * FUSE_ATTR_DAX: Enable DAX for this file in per inode DAX mode
577  */
578 #define FUSE_ATTR_SUBMOUNT      (1 << 0)
579 #define FUSE_ATTR_DAX		(1 << 1)
580 
581 /**
582  * Open flags
583  * FUSE_OPEN_KILL_SUIDGID: Kill suid and sgid if executable
584  */
585 #define FUSE_OPEN_KILL_SUIDGID	(1 << 0)
586 
587 /**
588  * setxattr flags
589  * FUSE_SETXATTR_ACL_KILL_SGID: Clear SGID when system.posix_acl_access is set
590  */
591 #define FUSE_SETXATTR_ACL_KILL_SGID	(1 << 0)
592 
593 /**
594  * notify_inval_entry flags
595  * FUSE_EXPIRE_ONLY
596  */
597 #define FUSE_EXPIRE_ONLY		(1 << 0)
598 
599 /**
600  * extension type
601  * FUSE_MAX_NR_SECCTX: maximum value of &fuse_secctx_header.nr_secctx
602  * FUSE_EXT_GROUPS: &fuse_supp_groups extension
603  */
604 enum fuse_ext_type {
605 	/* Types 0..31 are reserved for fuse_secctx_header */
606 	FUSE_MAX_NR_SECCTX	= 31,
607 	FUSE_EXT_GROUPS		= 32,
608 };
609 
610 enum fuse_opcode {
611 	FUSE_LOOKUP		= 1,
612 	FUSE_FORGET		= 2,  /* no reply */
613 	FUSE_GETATTR		= 3,
614 	FUSE_SETATTR		= 4,
615 	FUSE_READLINK		= 5,
616 	FUSE_SYMLINK		= 6,
617 	FUSE_MKNOD		= 8,
618 	FUSE_MKDIR		= 9,
619 	FUSE_UNLINK		= 10,
620 	FUSE_RMDIR		= 11,
621 	FUSE_RENAME		= 12,
622 	FUSE_LINK		= 13,
623 	FUSE_OPEN		= 14,
624 	FUSE_READ		= 15,
625 	FUSE_WRITE		= 16,
626 	FUSE_STATFS		= 17,
627 	FUSE_RELEASE		= 18,
628 	FUSE_FSYNC		= 20,
629 	FUSE_SETXATTR		= 21,
630 	FUSE_GETXATTR		= 22,
631 	FUSE_LISTXATTR		= 23,
632 	FUSE_REMOVEXATTR	= 24,
633 	FUSE_FLUSH		= 25,
634 	FUSE_INIT		= 26,
635 	FUSE_OPENDIR		= 27,
636 	FUSE_READDIR		= 28,
637 	FUSE_RELEASEDIR		= 29,
638 	FUSE_FSYNCDIR		= 30,
639 	FUSE_GETLK		= 31,
640 	FUSE_SETLK		= 32,
641 	FUSE_SETLKW		= 33,
642 	FUSE_ACCESS		= 34,
643 	FUSE_CREATE		= 35,
644 	FUSE_INTERRUPT		= 36,
645 	FUSE_BMAP		= 37,
646 	FUSE_DESTROY		= 38,
647 	FUSE_IOCTL		= 39,
648 	FUSE_POLL		= 40,
649 	FUSE_NOTIFY_REPLY	= 41,
650 	FUSE_BATCH_FORGET	= 42,
651 	FUSE_FALLOCATE		= 43,
652 	FUSE_READDIRPLUS	= 44,
653 	FUSE_RENAME2		= 45,
654 	FUSE_LSEEK		= 46,
655 	FUSE_COPY_FILE_RANGE	= 47,
656 	FUSE_SETUPMAPPING	= 48,
657 	FUSE_REMOVEMAPPING	= 49,
658 	FUSE_SYNCFS		= 50,
659 	FUSE_TMPFILE		= 51,
660 	FUSE_STATX		= 52,
661 	FUSE_COPY_FILE_RANGE_64	= 53,
662 
663 	/* CUSE specific operations */
664 	CUSE_INIT		= 4096,
665 
666 	/* Reserved opcodes: helpful to detect structure endian-ness */
667 	CUSE_INIT_BSWAP_RESERVED	= 1048576,	/* CUSE_INIT << 8 */
668 	FUSE_INIT_BSWAP_RESERVED	= 436207616,	/* FUSE_INIT << 24 */
669 };
670 
671 enum fuse_notify_code {
672 	FUSE_NOTIFY_POLL   = 1,
673 	FUSE_NOTIFY_INVAL_INODE = 2,
674 	FUSE_NOTIFY_INVAL_ENTRY = 3,
675 	FUSE_NOTIFY_STORE = 4,
676 	FUSE_NOTIFY_RETRIEVE = 5,
677 	FUSE_NOTIFY_DELETE = 6,
678 	FUSE_NOTIFY_RESEND = 7,
679 	FUSE_NOTIFY_INC_EPOCH = 8,
680 	FUSE_NOTIFY_PRUNE = 9,
681 };
682 
683 /* The read buffer is required to be at least 8k, but may be much larger */
684 #define FUSE_MIN_READ_BUFFER 8192
685 
686 #define FUSE_COMPAT_ENTRY_OUT_SIZE 120
687 
688 struct fuse_entry_out {
689 	uint64_t	nodeid;		/* Inode ID */
690 	uint64_t	generation;	/* Inode generation: nodeid:gen must
691 					   be unique for the fs's lifetime */
692 	uint64_t	entry_valid;	/* Cache timeout for the name */
693 	uint64_t	attr_valid;	/* Cache timeout for the attributes */
694 	uint32_t	entry_valid_nsec;
695 	uint32_t	attr_valid_nsec;
696 	struct fuse_attr attr;
697 };
698 
699 struct fuse_forget_in {
700 	uint64_t	nlookup;
701 };
702 
703 struct fuse_forget_one {
704 	uint64_t	nodeid;
705 	uint64_t	nlookup;
706 };
707 
708 struct fuse_batch_forget_in {
709 	uint32_t	count;
710 	uint32_t	dummy;
711 };
712 
713 struct fuse_getattr_in {
714 	uint32_t	getattr_flags;
715 	uint32_t	dummy;
716 	uint64_t	fh;
717 };
718 
719 #define FUSE_COMPAT_ATTR_OUT_SIZE 96
720 
721 struct fuse_attr_out {
722 	uint64_t	attr_valid;	/* Cache timeout for the attributes */
723 	uint32_t	attr_valid_nsec;
724 	uint32_t	dummy;
725 	struct fuse_attr attr;
726 };
727 
728 struct fuse_statx_in {
729 	uint32_t	getattr_flags;
730 	uint32_t	reserved;
731 	uint64_t	fh;
732 	uint32_t	sx_flags;
733 	uint32_t	sx_mask;
734 };
735 
736 struct fuse_statx_out {
737 	uint64_t	attr_valid;	/* Cache timeout for the attributes */
738 	uint32_t	attr_valid_nsec;
739 	uint32_t	flags;
740 	uint64_t	spare[2];
741 	struct fuse_statx stat;
742 };
743 
744 #define FUSE_COMPAT_MKNOD_IN_SIZE 8
745 
746 struct fuse_mknod_in {
747 	uint32_t	mode;
748 	uint32_t	rdev;
749 	uint32_t	umask;
750 	uint32_t	padding;
751 };
752 
753 struct fuse_mkdir_in {
754 	uint32_t	mode;
755 	uint32_t	umask;
756 };
757 
758 struct fuse_rename_in {
759 	uint64_t	newdir;
760 };
761 
762 struct fuse_rename2_in {
763 	uint64_t	newdir;
764 	uint32_t	flags;
765 	uint32_t	padding;
766 };
767 
768 struct fuse_link_in {
769 	uint64_t	oldnodeid;
770 };
771 
772 struct fuse_setattr_in {
773 	uint32_t	valid;
774 	uint32_t	padding;
775 	uint64_t	fh;
776 	uint64_t	size;
777 	uint64_t	lock_owner;
778 	uint64_t	atime;
779 	uint64_t	mtime;
780 	uint64_t	ctime;
781 	uint32_t	atimensec;
782 	uint32_t	mtimensec;
783 	uint32_t	ctimensec;
784 	uint32_t	mode;
785 	uint32_t	unused4;
786 	uint32_t	uid;
787 	uint32_t	gid;
788 	uint32_t	unused5;
789 };
790 
791 struct fuse_open_in {
792 	uint32_t	flags;
793 	uint32_t	open_flags;	/* FUSE_OPEN_... */
794 };
795 
796 struct fuse_create_in {
797 	uint32_t	flags;
798 	uint32_t	mode;
799 	uint32_t	umask;
800 	uint32_t	open_flags;	/* FUSE_OPEN_... */
801 };
802 
803 struct fuse_open_out {
804 	uint64_t	fh;
805 	uint32_t	open_flags;
806 	int32_t		backing_id;
807 };
808 
809 struct fuse_release_in {
810 	uint64_t	fh;
811 	uint32_t	flags;
812 	uint32_t	release_flags;
813 	uint64_t	lock_owner;
814 };
815 
816 struct fuse_flush_in {
817 	uint64_t	fh;
818 	uint32_t	unused;
819 	uint32_t	padding;
820 	uint64_t	lock_owner;
821 };
822 
823 struct fuse_read_in {
824 	uint64_t	fh;
825 	uint64_t	offset;
826 	uint32_t	size;
827 	uint32_t	read_flags;
828 	uint64_t	lock_owner;
829 	uint32_t	flags;
830 	uint32_t	padding;
831 };
832 
833 #define FUSE_COMPAT_WRITE_IN_SIZE 24
834 
835 struct fuse_write_in {
836 	uint64_t	fh;
837 	uint64_t	offset;
838 	uint32_t	size;
839 	uint32_t	write_flags;
840 	uint64_t	lock_owner;
841 	uint32_t	flags;
842 	uint32_t	padding;
843 };
844 
845 struct fuse_write_out {
846 	uint32_t	size;
847 	uint32_t	padding;
848 };
849 
850 #define FUSE_COMPAT_STATFS_SIZE 48
851 
852 struct fuse_statfs_out {
853 	struct fuse_kstatfs st;
854 };
855 
856 struct fuse_fsync_in {
857 	uint64_t	fh;
858 	uint32_t	fsync_flags;
859 	uint32_t	padding;
860 };
861 
862 #define FUSE_COMPAT_SETXATTR_IN_SIZE 8
863 
864 struct fuse_setxattr_in {
865 	uint32_t	size;
866 	uint32_t	flags;
867 	uint32_t	setxattr_flags;
868 	uint32_t	padding;
869 };
870 
871 struct fuse_getxattr_in {
872 	uint32_t	size;
873 	uint32_t	padding;
874 };
875 
876 struct fuse_getxattr_out {
877 	uint32_t	size;
878 	uint32_t	padding;
879 };
880 
881 struct fuse_lk_in {
882 	uint64_t	fh;
883 	uint64_t	owner;
884 	struct fuse_file_lock lk;
885 	uint32_t	lk_flags;
886 	uint32_t	padding;
887 };
888 
889 struct fuse_lk_out {
890 	struct fuse_file_lock lk;
891 };
892 
893 struct fuse_access_in {
894 	uint32_t	mask;
895 	uint32_t	padding;
896 };
897 
898 struct fuse_init_in {
899 	uint32_t	major;
900 	uint32_t	minor;
901 	uint32_t	max_readahead;
902 	uint32_t	flags;
903 	uint32_t	flags2;
904 	uint32_t	unused[11];
905 };
906 
907 #define FUSE_COMPAT_INIT_OUT_SIZE 8
908 #define FUSE_COMPAT_22_INIT_OUT_SIZE 24
909 
910 struct fuse_init_out {
911 	uint32_t	major;
912 	uint32_t	minor;
913 	uint32_t	max_readahead;
914 	uint32_t	flags;
915 	uint16_t	max_background;
916 	uint16_t	congestion_threshold;
917 	uint32_t	max_write;
918 	uint32_t	time_gran;
919 	uint16_t	max_pages;
920 	uint16_t	map_alignment;
921 	uint32_t	flags2;
922 	uint32_t	max_stack_depth;
923 	uint16_t	request_timeout;
924 	uint16_t	unused[11];
925 };
926 
927 #define CUSE_INIT_INFO_MAX 4096
928 
929 struct cuse_init_in {
930 	uint32_t	major;
931 	uint32_t	minor;
932 	uint32_t	unused;
933 	uint32_t	flags;
934 };
935 
936 struct cuse_init_out {
937 	uint32_t	major;
938 	uint32_t	minor;
939 	uint32_t	unused;
940 	uint32_t	flags;
941 	uint32_t	max_read;
942 	uint32_t	max_write;
943 	uint32_t	dev_major;		/* chardev major */
944 	uint32_t	dev_minor;		/* chardev minor */
945 	uint32_t	spare[10];
946 };
947 
948 struct fuse_interrupt_in {
949 	uint64_t	unique;
950 };
951 
952 struct fuse_bmap_in {
953 	uint64_t	block;
954 	uint32_t	blocksize;
955 	uint32_t	padding;
956 };
957 
958 struct fuse_bmap_out {
959 	uint64_t	block;
960 };
961 
962 struct fuse_ioctl_in {
963 	uint64_t	fh;
964 	uint32_t	flags;
965 	uint32_t	cmd;
966 	uint64_t	arg;
967 	uint32_t	in_size;
968 	uint32_t	out_size;
969 };
970 
971 struct fuse_ioctl_iovec {
972 	uint64_t	base;
973 	uint64_t	len;
974 };
975 
976 struct fuse_ioctl_out {
977 	int32_t		result;
978 	uint32_t	flags;
979 	uint32_t	in_iovs;
980 	uint32_t	out_iovs;
981 };
982 
983 struct fuse_poll_in {
984 	uint64_t	fh;
985 	uint64_t	kh;
986 	uint32_t	flags;
987 	uint32_t	events;
988 };
989 
990 struct fuse_poll_out {
991 	uint32_t	revents;
992 	uint32_t	padding;
993 };
994 
995 struct fuse_notify_poll_wakeup_out {
996 	uint64_t	kh;
997 };
998 
999 struct fuse_fallocate_in {
1000 	uint64_t	fh;
1001 	uint64_t	offset;
1002 	uint64_t	length;
1003 	uint32_t	mode;
1004 	uint32_t	padding;
1005 };
1006 
1007 /**
1008  * FUSE request unique ID flag
1009  *
1010  * Indicates whether this is a resend request. The receiver should handle this
1011  * request accordingly.
1012  */
1013 #define FUSE_UNIQUE_RESEND (1ULL << 63)
1014 
1015 /**
1016  * This value will be set by the kernel to
1017  * (struct fuse_in_header).{uid,gid} fields in
1018  * case when:
1019  * - fuse daemon enabled FUSE_ALLOW_IDMAP
1020  * - idmapping information is not available and uid/gid
1021  *   can not be mapped in accordance with an idmapping.
1022  *
1023  * Note: an idmapping information always available
1024  * for inode creation operations like:
1025  * FUSE_MKNOD, FUSE_SYMLINK, FUSE_MKDIR, FUSE_TMPFILE,
1026  * FUSE_CREATE and FUSE_RENAME2 (with RENAME_WHITEOUT).
1027  */
1028 #define FUSE_INVALID_UIDGID ((uint32_t)(-1))
1029 
1030 struct fuse_in_header {
1031 	uint32_t	len;
1032 	uint32_t	opcode;
1033 	uint64_t	unique;
1034 	uint64_t	nodeid;
1035 	uint32_t	uid;
1036 	uint32_t	gid;
1037 	uint32_t	pid;
1038 	uint16_t	total_extlen; /* length of extensions in 8byte units */
1039 	uint16_t	padding;
1040 };
1041 
1042 struct fuse_out_header {
1043 	uint32_t	len;
1044 	int32_t		error;
1045 	uint64_t	unique;
1046 };
1047 
1048 struct fuse_dirent {
1049 	uint64_t	ino;
1050 	uint64_t	off;
1051 	uint32_t	namelen;
1052 	uint32_t	type;
1053 	char name[];
1054 };
1055 
1056 /* Align variable length records to 64bit boundary */
1057 #define FUSE_REC_ALIGN(x) \
1058 	(((x) + sizeof(uint64_t) - 1) & ~(sizeof(uint64_t) - 1))
1059 
1060 #define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
1061 #define FUSE_DIRENT_ALIGN(x) FUSE_REC_ALIGN(x)
1062 #define FUSE_DIRENT_SIZE(d) \
1063 	FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)
1064 
1065 struct fuse_direntplus {
1066 	struct fuse_entry_out entry_out;
1067 	struct fuse_dirent dirent;
1068 };
1069 
1070 #define FUSE_NAME_OFFSET_DIRENTPLUS \
1071 	offsetof(struct fuse_direntplus, dirent.name)
1072 #define FUSE_DIRENTPLUS_SIZE(d) \
1073 	FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET_DIRENTPLUS + (d)->dirent.namelen)
1074 
1075 struct fuse_notify_inval_inode_out {
1076 	uint64_t	ino;
1077 	int64_t		off;
1078 	int64_t		len;
1079 };
1080 
1081 struct fuse_notify_inval_entry_out {
1082 	uint64_t	parent;
1083 	uint32_t	namelen;
1084 	uint32_t	flags;
1085 };
1086 
1087 struct fuse_notify_delete_out {
1088 	uint64_t	parent;
1089 	uint64_t	child;
1090 	uint32_t	namelen;
1091 	uint32_t	padding;
1092 };
1093 
1094 struct fuse_notify_store_out {
1095 	uint64_t	nodeid;
1096 	uint64_t	offset;
1097 	uint32_t	size;
1098 	uint32_t	padding;
1099 };
1100 
1101 struct fuse_notify_retrieve_out {
1102 	uint64_t	notify_unique;
1103 	uint64_t	nodeid;
1104 	uint64_t	offset;
1105 	uint32_t	size;
1106 	uint32_t	padding;
1107 };
1108 
1109 /* Matches the size of fuse_write_in */
1110 struct fuse_notify_retrieve_in {
1111 	uint64_t	dummy1;
1112 	uint64_t	offset;
1113 	uint32_t	size;
1114 	uint32_t	dummy2;
1115 	uint64_t	dummy3;
1116 	uint64_t	dummy4;
1117 };
1118 
1119 struct fuse_notify_prune_out {
1120 	uint32_t	count;
1121 	uint32_t	padding;
1122 	uint64_t	spare;
1123 };
1124 
1125 struct fuse_backing_map {
1126 	int32_t		fd;
1127 	uint32_t	flags;
1128 	uint64_t	padding;
1129 };
1130 
1131 /* Device ioctls: */
1132 #define FUSE_DEV_IOC_MAGIC		229
1133 #define FUSE_DEV_IOC_CLONE		_IOR(FUSE_DEV_IOC_MAGIC, 0, uint32_t)
1134 #define FUSE_DEV_IOC_BACKING_OPEN	_IOW(FUSE_DEV_IOC_MAGIC, 1, \
1135 					     struct fuse_backing_map)
1136 #define FUSE_DEV_IOC_BACKING_CLOSE	_IOW(FUSE_DEV_IOC_MAGIC, 2, uint32_t)
1137 #define FUSE_DEV_IOC_SYNC_INIT		_IO(FUSE_DEV_IOC_MAGIC, 3)
1138 
1139 struct fuse_lseek_in {
1140 	uint64_t	fh;
1141 	uint64_t	offset;
1142 	uint32_t	whence;
1143 	uint32_t	padding;
1144 };
1145 
1146 struct fuse_lseek_out {
1147 	uint64_t	offset;
1148 };
1149 
1150 struct fuse_copy_file_range_in {
1151 	uint64_t	fh_in;
1152 	uint64_t	off_in;
1153 	uint64_t	nodeid_out;
1154 	uint64_t	fh_out;
1155 	uint64_t	off_out;
1156 	uint64_t	len;
1157 	uint64_t	flags;
1158 };
1159 
1160 /* For FUSE_COPY_FILE_RANGE_64 */
1161 struct fuse_copy_file_range_out {
1162 	uint64_t	bytes_copied;
1163 };
1164 
1165 #define FUSE_SETUPMAPPING_FLAG_WRITE (1ull << 0)
1166 #define FUSE_SETUPMAPPING_FLAG_READ (1ull << 1)
1167 struct fuse_setupmapping_in {
1168 	/* An already open handle */
1169 	uint64_t	fh;
1170 	/* Offset into the file to start the mapping */
1171 	uint64_t	foffset;
1172 	/* Length of mapping required */
1173 	uint64_t	len;
1174 	/* Flags, FUSE_SETUPMAPPING_FLAG_* */
1175 	uint64_t	flags;
1176 	/* Offset in Memory Window */
1177 	uint64_t	moffset;
1178 };
1179 
1180 struct fuse_removemapping_in {
1181 	/* number of fuse_removemapping_one follows */
1182 	uint32_t        count;
1183 };
1184 
1185 struct fuse_removemapping_one {
1186 	/* Offset into the dax window start the unmapping */
1187 	uint64_t        moffset;
1188 	/* Length of mapping required */
1189 	uint64_t	len;
1190 };
1191 
1192 #define FUSE_REMOVEMAPPING_MAX_ENTRY   \
1193 		(PAGE_SIZE / sizeof(struct fuse_removemapping_one))
1194 
1195 struct fuse_syncfs_in {
1196 	uint64_t	padding;
1197 };
1198 
1199 /*
1200  * For each security context, send fuse_secctx with size of security context
1201  * fuse_secctx will be followed by security context name and this in turn
1202  * will be followed by actual context label.
1203  * fuse_secctx, name, context
1204  */
1205 struct fuse_secctx {
1206 	uint32_t	size;
1207 	uint32_t	padding;
1208 };
1209 
1210 /*
1211  * Contains the information about how many fuse_secctx structures are being
1212  * sent and what's the total size of all security contexts (including
1213  * size of fuse_secctx_header).
1214  *
1215  */
1216 struct fuse_secctx_header {
1217 	uint32_t	size;
1218 	uint32_t	nr_secctx;
1219 };
1220 
1221 /**
1222  * struct fuse_ext_header - extension header
1223  * @size: total size of this extension including this header
1224  * @type: type of extension
1225  *
1226  * This is made compatible with fuse_secctx_header by using type values >
1227  * FUSE_MAX_NR_SECCTX
1228  */
1229 struct fuse_ext_header {
1230 	uint32_t	size;
1231 	uint32_t	type;
1232 };
1233 
1234 /**
1235  * struct fuse_supp_groups - Supplementary group extension
1236  * @nr_groups: number of supplementary groups
1237  * @groups: flexible array of group IDs
1238  */
1239 struct fuse_supp_groups {
1240 	uint32_t	nr_groups;
1241 	uint32_t	groups[];
1242 };
1243 
1244 /**
1245  * Size of the ring buffer header
1246  */
1247 #define FUSE_URING_IN_OUT_HEADER_SZ 128
1248 #define FUSE_URING_OP_IN_OUT_SZ 128
1249 
1250 /* Used as part of the fuse_uring_req_header */
1251 struct fuse_uring_ent_in_out {
1252 	uint64_t flags;
1253 
1254 	/*
1255 	 * commit ID to be used in a reply to a ring request (see also
1256 	 * struct fuse_uring_cmd_req)
1257 	 */
1258 	uint64_t commit_id;
1259 
1260 	/* size of user payload buffer */
1261 	uint32_t payload_sz;
1262 	uint32_t padding;
1263 
1264 	uint64_t reserved;
1265 };
1266 
1267 /**
1268  * Header for all fuse-io-uring requests
1269  */
1270 struct fuse_uring_req_header {
1271 	/* struct fuse_in_header / struct fuse_out_header */
1272 	char in_out[FUSE_URING_IN_OUT_HEADER_SZ];
1273 
1274 	/* per op code header */
1275 	char op_in[FUSE_URING_OP_IN_OUT_SZ];
1276 
1277 	struct fuse_uring_ent_in_out ring_ent_in_out;
1278 };
1279 
1280 /**
1281  * sqe commands to the kernel
1282  */
1283 enum fuse_uring_cmd {
1284 	FUSE_IO_URING_CMD_INVALID = 0,
1285 
1286 	/* register the request buffer and fetch a fuse request */
1287 	FUSE_IO_URING_CMD_REGISTER = 1,
1288 
1289 	/* commit fuse request result and fetch next request */
1290 	FUSE_IO_URING_CMD_COMMIT_AND_FETCH = 2,
1291 };
1292 
1293 /**
1294  * In the 80B command area of the SQE.
1295  */
1296 struct fuse_uring_cmd_req {
1297 	uint64_t flags;
1298 
1299 	/* entry identifier for commits */
1300 	uint64_t commit_id;
1301 
1302 	/* queue the command is for (queue index) */
1303 	uint16_t qid;
1304 	uint8_t padding[6];
1305 };
1306 
1307 #endif /* _LINUX_FUSE_H */
1308