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