xref: /linux/include/uapi/linux/fuse.h (revision ab93e0dd72c37d378dd936f031ffb83ff2bd87ce)
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 
240 #ifndef _LINUX_FUSE_H
241 #define _LINUX_FUSE_H
242 
243 #ifdef __KERNEL__
244 #include <linux/types.h>
245 #else
246 #include <stdint.h>
247 #endif
248 
249 /*
250  * Version negotiation:
251  *
252  * Both the kernel and userspace send the version they support in the
253  * INIT request and reply respectively.
254  *
255  * If the major versions match then both shall use the smallest
256  * of the two minor versions for communication.
257  *
258  * If the kernel supports a larger major version, then userspace shall
259  * reply with the major version it supports, ignore the rest of the
260  * INIT message and expect a new INIT message from the kernel with a
261  * matching major version.
262  *
263  * If the library supports a larger major version, then it shall fall
264  * back to the major protocol version sent by the kernel for
265  * communication and reply with that major version (and an arbitrary
266  * supported minor version).
267  */
268 
269 /** Version number of this interface */
270 #define FUSE_KERNEL_VERSION 7
271 
272 /** Minor version number of this interface */
273 #define FUSE_KERNEL_MINOR_VERSION 44
274 
275 /** The node ID of the root inode */
276 #define FUSE_ROOT_ID 1
277 
278 /* Make sure all structures are padded to 64bit boundary, so 32bit
279    userspace works under 64bit kernels */
280 
281 struct fuse_attr {
282 	uint64_t	ino;
283 	uint64_t	size;
284 	uint64_t	blocks;
285 	uint64_t	atime;
286 	uint64_t	mtime;
287 	uint64_t	ctime;
288 	uint32_t	atimensec;
289 	uint32_t	mtimensec;
290 	uint32_t	ctimensec;
291 	uint32_t	mode;
292 	uint32_t	nlink;
293 	uint32_t	uid;
294 	uint32_t	gid;
295 	uint32_t	rdev;
296 	uint32_t	blksize;
297 	uint32_t	flags;
298 };
299 
300 /*
301  * The following structures are bit-for-bit compatible with the statx(2) ABI in
302  * Linux.
303  */
304 struct fuse_sx_time {
305 	int64_t		tv_sec;
306 	uint32_t	tv_nsec;
307 	int32_t		__reserved;
308 };
309 
310 struct fuse_statx {
311 	uint32_t	mask;
312 	uint32_t	blksize;
313 	uint64_t	attributes;
314 	uint32_t	nlink;
315 	uint32_t	uid;
316 	uint32_t	gid;
317 	uint16_t	mode;
318 	uint16_t	__spare0[1];
319 	uint64_t	ino;
320 	uint64_t	size;
321 	uint64_t	blocks;
322 	uint64_t	attributes_mask;
323 	struct fuse_sx_time	atime;
324 	struct fuse_sx_time	btime;
325 	struct fuse_sx_time	ctime;
326 	struct fuse_sx_time	mtime;
327 	uint32_t	rdev_major;
328 	uint32_t	rdev_minor;
329 	uint32_t	dev_major;
330 	uint32_t	dev_minor;
331 	uint64_t	__spare2[14];
332 };
333 
334 struct fuse_kstatfs {
335 	uint64_t	blocks;
336 	uint64_t	bfree;
337 	uint64_t	bavail;
338 	uint64_t	files;
339 	uint64_t	ffree;
340 	uint32_t	bsize;
341 	uint32_t	namelen;
342 	uint32_t	frsize;
343 	uint32_t	padding;
344 	uint32_t	spare[6];
345 };
346 
347 struct fuse_file_lock {
348 	uint64_t	start;
349 	uint64_t	end;
350 	uint32_t	type;
351 	uint32_t	pid; /* tgid */
352 };
353 
354 /**
355  * Bitmasks for fuse_setattr_in.valid
356  */
357 #define FATTR_MODE	(1 << 0)
358 #define FATTR_UID	(1 << 1)
359 #define FATTR_GID	(1 << 2)
360 #define FATTR_SIZE	(1 << 3)
361 #define FATTR_ATIME	(1 << 4)
362 #define FATTR_MTIME	(1 << 5)
363 #define FATTR_FH	(1 << 6)
364 #define FATTR_ATIME_NOW	(1 << 7)
365 #define FATTR_MTIME_NOW	(1 << 8)
366 #define FATTR_LOCKOWNER	(1 << 9)
367 #define FATTR_CTIME	(1 << 10)
368 #define FATTR_KILL_SUIDGID	(1 << 11)
369 
370 /**
371  * Flags returned by the OPEN request
372  *
373  * FOPEN_DIRECT_IO: bypass page cache for this open file
374  * FOPEN_KEEP_CACHE: don't invalidate the data cache on open
375  * FOPEN_NONSEEKABLE: the file is not seekable
376  * FOPEN_CACHE_DIR: allow caching this directory
377  * FOPEN_STREAM: the file is stream-like (no file position at all)
378  * FOPEN_NOFLUSH: don't flush data cache on close (unless FUSE_WRITEBACK_CACHE)
379  * FOPEN_PARALLEL_DIRECT_WRITES: Allow concurrent direct writes on the same inode
380  * FOPEN_PASSTHROUGH: passthrough read/write io for this open file
381  */
382 #define FOPEN_DIRECT_IO		(1 << 0)
383 #define FOPEN_KEEP_CACHE	(1 << 1)
384 #define FOPEN_NONSEEKABLE	(1 << 2)
385 #define FOPEN_CACHE_DIR		(1 << 3)
386 #define FOPEN_STREAM		(1 << 4)
387 #define FOPEN_NOFLUSH		(1 << 5)
388 #define FOPEN_PARALLEL_DIRECT_WRITES	(1 << 6)
389 #define FOPEN_PASSTHROUGH	(1 << 7)
390 
391 /**
392  * INIT request/reply flags
393  *
394  * FUSE_ASYNC_READ: asynchronous read requests
395  * FUSE_POSIX_LOCKS: remote locking for POSIX file locks
396  * FUSE_FILE_OPS: kernel sends file handle for fstat, etc... (not yet supported)
397  * FUSE_ATOMIC_O_TRUNC: handles the O_TRUNC open flag in the filesystem
398  * FUSE_EXPORT_SUPPORT: filesystem handles lookups of "." and ".."
399  * FUSE_BIG_WRITES: filesystem can handle write size larger than 4kB
400  * FUSE_DONT_MASK: don't apply umask to file mode on create operations
401  * FUSE_SPLICE_WRITE: kernel supports splice write on the device
402  * FUSE_SPLICE_MOVE: kernel supports splice move on the device
403  * FUSE_SPLICE_READ: kernel supports splice read on the device
404  * FUSE_FLOCK_LOCKS: remote locking for BSD style file locks
405  * FUSE_HAS_IOCTL_DIR: kernel supports ioctl on directories
406  * FUSE_AUTO_INVAL_DATA: automatically invalidate cached pages
407  * FUSE_DO_READDIRPLUS: do READDIRPLUS (READDIR+LOOKUP in one)
408  * FUSE_READDIRPLUS_AUTO: adaptive readdirplus
409  * FUSE_ASYNC_DIO: asynchronous direct I/O submission
410  * FUSE_WRITEBACK_CACHE: use writeback cache for buffered writes
411  * FUSE_NO_OPEN_SUPPORT: kernel supports zero-message opens
412  * FUSE_PARALLEL_DIROPS: allow parallel lookups and readdir
413  * FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on write/chown/trunc
414  * FUSE_POSIX_ACL: filesystem supports posix acls
415  * FUSE_ABORT_ERROR: reading the device after abort returns ECONNABORTED
416  * FUSE_MAX_PAGES: init_out.max_pages contains the max number of req pages
417  * FUSE_CACHE_SYMLINKS: cache READLINK responses
418  * FUSE_NO_OPENDIR_SUPPORT: kernel supports zero-message opendir
419  * FUSE_EXPLICIT_INVAL_DATA: only invalidate cached pages on explicit request
420  * FUSE_MAP_ALIGNMENT: init_out.map_alignment contains log2(byte alignment) for
421  *		       foffset and moffset fields in struct
422  *		       fuse_setupmapping_out and fuse_removemapping_one.
423  * FUSE_SUBMOUNTS: kernel supports auto-mounting directory submounts
424  * FUSE_HANDLE_KILLPRIV_V2: fs kills suid/sgid/cap on write/chown/trunc.
425  *			Upon write/truncate suid/sgid is only killed if caller
426  *			does not have CAP_FSETID. Additionally upon
427  *			write/truncate sgid is killed only if file has group
428  *			execute permission. (Same as Linux VFS behavior).
429  * FUSE_SETXATTR_EXT:	Server supports extended struct fuse_setxattr_in
430  * FUSE_INIT_EXT: extended fuse_init_in request
431  * FUSE_INIT_RESERVED: reserved, do not use
432  * FUSE_SECURITY_CTX:	add security context to create, mkdir, symlink, and
433  *			mknod
434  * FUSE_HAS_INODE_DAX:  use per inode DAX
435  * FUSE_CREATE_SUPP_GROUP: add supplementary group info to create, mkdir,
436  *			symlink and mknod (single group that matches parent)
437  * FUSE_HAS_EXPIRE_ONLY: kernel supports expiry-only entry invalidation
438  * FUSE_DIRECT_IO_ALLOW_MMAP: allow shared mmap in FOPEN_DIRECT_IO mode.
439  * FUSE_NO_EXPORT_SUPPORT: explicitly disable export support
440  * FUSE_HAS_RESEND: kernel supports resending pending requests, and the high bit
441  *		    of the request ID indicates resend requests
442  * FUSE_ALLOW_IDMAP: allow creation of idmapped mounts
443  * FUSE_OVER_IO_URING: Indicate that client supports io-uring
444  * FUSE_REQUEST_TIMEOUT: kernel supports timing out requests.
445  *			 init_out.request_timeout contains the timeout (in secs)
446  */
447 #define FUSE_ASYNC_READ		(1 << 0)
448 #define FUSE_POSIX_LOCKS	(1 << 1)
449 #define FUSE_FILE_OPS		(1 << 2)
450 #define FUSE_ATOMIC_O_TRUNC	(1 << 3)
451 #define FUSE_EXPORT_SUPPORT	(1 << 4)
452 #define FUSE_BIG_WRITES		(1 << 5)
453 #define FUSE_DONT_MASK		(1 << 6)
454 #define FUSE_SPLICE_WRITE	(1 << 7)
455 #define FUSE_SPLICE_MOVE	(1 << 8)
456 #define FUSE_SPLICE_READ	(1 << 9)
457 #define FUSE_FLOCK_LOCKS	(1 << 10)
458 #define FUSE_HAS_IOCTL_DIR	(1 << 11)
459 #define FUSE_AUTO_INVAL_DATA	(1 << 12)
460 #define FUSE_DO_READDIRPLUS	(1 << 13)
461 #define FUSE_READDIRPLUS_AUTO	(1 << 14)
462 #define FUSE_ASYNC_DIO		(1 << 15)
463 #define FUSE_WRITEBACK_CACHE	(1 << 16)
464 #define FUSE_NO_OPEN_SUPPORT	(1 << 17)
465 #define FUSE_PARALLEL_DIROPS    (1 << 18)
466 #define FUSE_HANDLE_KILLPRIV	(1 << 19)
467 #define FUSE_POSIX_ACL		(1 << 20)
468 #define FUSE_ABORT_ERROR	(1 << 21)
469 #define FUSE_MAX_PAGES		(1 << 22)
470 #define FUSE_CACHE_SYMLINKS	(1 << 23)
471 #define FUSE_NO_OPENDIR_SUPPORT (1 << 24)
472 #define FUSE_EXPLICIT_INVAL_DATA (1 << 25)
473 #define FUSE_MAP_ALIGNMENT	(1 << 26)
474 #define FUSE_SUBMOUNTS		(1 << 27)
475 #define FUSE_HANDLE_KILLPRIV_V2	(1 << 28)
476 #define FUSE_SETXATTR_EXT	(1 << 29)
477 #define FUSE_INIT_EXT		(1 << 30)
478 #define FUSE_INIT_RESERVED	(1 << 31)
479 /* bits 32..63 get shifted down 32 bits into the flags2 field */
480 #define FUSE_SECURITY_CTX	(1ULL << 32)
481 #define FUSE_HAS_INODE_DAX	(1ULL << 33)
482 #define FUSE_CREATE_SUPP_GROUP	(1ULL << 34)
483 #define FUSE_HAS_EXPIRE_ONLY	(1ULL << 35)
484 #define FUSE_DIRECT_IO_ALLOW_MMAP (1ULL << 36)
485 #define FUSE_PASSTHROUGH	(1ULL << 37)
486 #define FUSE_NO_EXPORT_SUPPORT	(1ULL << 38)
487 #define FUSE_HAS_RESEND		(1ULL << 39)
488 /* Obsolete alias for FUSE_DIRECT_IO_ALLOW_MMAP */
489 #define FUSE_DIRECT_IO_RELAX	FUSE_DIRECT_IO_ALLOW_MMAP
490 #define FUSE_ALLOW_IDMAP	(1ULL << 40)
491 #define FUSE_OVER_IO_URING	(1ULL << 41)
492 #define FUSE_REQUEST_TIMEOUT	(1ULL << 42)
493 
494 /**
495  * CUSE INIT request/reply flags
496  *
497  * CUSE_UNRESTRICTED_IOCTL:  use unrestricted ioctl
498  */
499 #define CUSE_UNRESTRICTED_IOCTL	(1 << 0)
500 
501 /**
502  * Release flags
503  */
504 #define FUSE_RELEASE_FLUSH	(1 << 0)
505 #define FUSE_RELEASE_FLOCK_UNLOCK	(1 << 1)
506 
507 /**
508  * Getattr flags
509  */
510 #define FUSE_GETATTR_FH		(1 << 0)
511 
512 /**
513  * Lock flags
514  */
515 #define FUSE_LK_FLOCK		(1 << 0)
516 
517 /**
518  * WRITE flags
519  *
520  * FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
521  * FUSE_WRITE_LOCKOWNER: lock_owner field is valid
522  * FUSE_WRITE_KILL_SUIDGID: kill suid and sgid bits
523  */
524 #define FUSE_WRITE_CACHE	(1 << 0)
525 #define FUSE_WRITE_LOCKOWNER	(1 << 1)
526 #define FUSE_WRITE_KILL_SUIDGID (1 << 2)
527 
528 /* Obsolete alias; this flag implies killing suid/sgid only. */
529 #define FUSE_WRITE_KILL_PRIV	FUSE_WRITE_KILL_SUIDGID
530 
531 /**
532  * Read flags
533  */
534 #define FUSE_READ_LOCKOWNER	(1 << 1)
535 
536 /**
537  * Ioctl flags
538  *
539  * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
540  * FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
541  * FUSE_IOCTL_RETRY: retry with new iovecs
542  * FUSE_IOCTL_32BIT: 32bit ioctl
543  * FUSE_IOCTL_DIR: is a directory
544  * FUSE_IOCTL_COMPAT_X32: x32 compat ioctl on 64bit machine (64bit time_t)
545  *
546  * FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
547  */
548 #define FUSE_IOCTL_COMPAT	(1 << 0)
549 #define FUSE_IOCTL_UNRESTRICTED	(1 << 1)
550 #define FUSE_IOCTL_RETRY	(1 << 2)
551 #define FUSE_IOCTL_32BIT	(1 << 3)
552 #define FUSE_IOCTL_DIR		(1 << 4)
553 #define FUSE_IOCTL_COMPAT_X32	(1 << 5)
554 
555 #define FUSE_IOCTL_MAX_IOV	256
556 
557 /**
558  * Poll flags
559  *
560  * FUSE_POLL_SCHEDULE_NOTIFY: request poll notify
561  */
562 #define FUSE_POLL_SCHEDULE_NOTIFY (1 << 0)
563 
564 /**
565  * Fsync flags
566  *
567  * FUSE_FSYNC_FDATASYNC: Sync data only, not metadata
568  */
569 #define FUSE_FSYNC_FDATASYNC	(1 << 0)
570 
571 /**
572  * fuse_attr flags
573  *
574  * FUSE_ATTR_SUBMOUNT: Object is a submount root
575  * FUSE_ATTR_DAX: Enable DAX for this file in per inode DAX mode
576  */
577 #define FUSE_ATTR_SUBMOUNT      (1 << 0)
578 #define FUSE_ATTR_DAX		(1 << 1)
579 
580 /**
581  * Open flags
582  * FUSE_OPEN_KILL_SUIDGID: Kill suid and sgid if executable
583  */
584 #define FUSE_OPEN_KILL_SUIDGID	(1 << 0)
585 
586 /**
587  * setxattr flags
588  * FUSE_SETXATTR_ACL_KILL_SGID: Clear SGID when system.posix_acl_access is set
589  */
590 #define FUSE_SETXATTR_ACL_KILL_SGID	(1 << 0)
591 
592 /**
593  * notify_inval_entry flags
594  * FUSE_EXPIRE_ONLY
595  */
596 #define FUSE_EXPIRE_ONLY		(1 << 0)
597 
598 /**
599  * extension type
600  * FUSE_MAX_NR_SECCTX: maximum value of &fuse_secctx_header.nr_secctx
601  * FUSE_EXT_GROUPS: &fuse_supp_groups extension
602  */
603 enum fuse_ext_type {
604 	/* Types 0..31 are reserved for fuse_secctx_header */
605 	FUSE_MAX_NR_SECCTX	= 31,
606 	FUSE_EXT_GROUPS		= 32,
607 };
608 
609 enum fuse_opcode {
610 	FUSE_LOOKUP		= 1,
611 	FUSE_FORGET		= 2,  /* no reply */
612 	FUSE_GETATTR		= 3,
613 	FUSE_SETATTR		= 4,
614 	FUSE_READLINK		= 5,
615 	FUSE_SYMLINK		= 6,
616 	FUSE_MKNOD		= 8,
617 	FUSE_MKDIR		= 9,
618 	FUSE_UNLINK		= 10,
619 	FUSE_RMDIR		= 11,
620 	FUSE_RENAME		= 12,
621 	FUSE_LINK		= 13,
622 	FUSE_OPEN		= 14,
623 	FUSE_READ		= 15,
624 	FUSE_WRITE		= 16,
625 	FUSE_STATFS		= 17,
626 	FUSE_RELEASE		= 18,
627 	FUSE_FSYNC		= 20,
628 	FUSE_SETXATTR		= 21,
629 	FUSE_GETXATTR		= 22,
630 	FUSE_LISTXATTR		= 23,
631 	FUSE_REMOVEXATTR	= 24,
632 	FUSE_FLUSH		= 25,
633 	FUSE_INIT		= 26,
634 	FUSE_OPENDIR		= 27,
635 	FUSE_READDIR		= 28,
636 	FUSE_RELEASEDIR		= 29,
637 	FUSE_FSYNCDIR		= 30,
638 	FUSE_GETLK		= 31,
639 	FUSE_SETLK		= 32,
640 	FUSE_SETLKW		= 33,
641 	FUSE_ACCESS		= 34,
642 	FUSE_CREATE		= 35,
643 	FUSE_INTERRUPT		= 36,
644 	FUSE_BMAP		= 37,
645 	FUSE_DESTROY		= 38,
646 	FUSE_IOCTL		= 39,
647 	FUSE_POLL		= 40,
648 	FUSE_NOTIFY_REPLY	= 41,
649 	FUSE_BATCH_FORGET	= 42,
650 	FUSE_FALLOCATE		= 43,
651 	FUSE_READDIRPLUS	= 44,
652 	FUSE_RENAME2		= 45,
653 	FUSE_LSEEK		= 46,
654 	FUSE_COPY_FILE_RANGE	= 47,
655 	FUSE_SETUPMAPPING	= 48,
656 	FUSE_REMOVEMAPPING	= 49,
657 	FUSE_SYNCFS		= 50,
658 	FUSE_TMPFILE		= 51,
659 	FUSE_STATX		= 52,
660 
661 	/* CUSE specific operations */
662 	CUSE_INIT		= 4096,
663 
664 	/* Reserved opcodes: helpful to detect structure endian-ness */
665 	CUSE_INIT_BSWAP_RESERVED	= 1048576,	/* CUSE_INIT << 8 */
666 	FUSE_INIT_BSWAP_RESERVED	= 436207616,	/* FUSE_INIT << 24 */
667 };
668 
669 enum fuse_notify_code {
670 	FUSE_NOTIFY_POLL   = 1,
671 	FUSE_NOTIFY_INVAL_INODE = 2,
672 	FUSE_NOTIFY_INVAL_ENTRY = 3,
673 	FUSE_NOTIFY_STORE = 4,
674 	FUSE_NOTIFY_RETRIEVE = 5,
675 	FUSE_NOTIFY_DELETE = 6,
676 	FUSE_NOTIFY_RESEND = 7,
677 	FUSE_NOTIFY_INC_EPOCH = 8,
678 	FUSE_NOTIFY_CODE_MAX,
679 };
680 
681 /* The read buffer is required to be at least 8k, but may be much larger */
682 #define FUSE_MIN_READ_BUFFER 8192
683 
684 #define FUSE_COMPAT_ENTRY_OUT_SIZE 120
685 
686 struct fuse_entry_out {
687 	uint64_t	nodeid;		/* Inode ID */
688 	uint64_t	generation;	/* Inode generation: nodeid:gen must
689 					   be unique for the fs's lifetime */
690 	uint64_t	entry_valid;	/* Cache timeout for the name */
691 	uint64_t	attr_valid;	/* Cache timeout for the attributes */
692 	uint32_t	entry_valid_nsec;
693 	uint32_t	attr_valid_nsec;
694 	struct fuse_attr attr;
695 };
696 
697 struct fuse_forget_in {
698 	uint64_t	nlookup;
699 };
700 
701 struct fuse_forget_one {
702 	uint64_t	nodeid;
703 	uint64_t	nlookup;
704 };
705 
706 struct fuse_batch_forget_in {
707 	uint32_t	count;
708 	uint32_t	dummy;
709 };
710 
711 struct fuse_getattr_in {
712 	uint32_t	getattr_flags;
713 	uint32_t	dummy;
714 	uint64_t	fh;
715 };
716 
717 #define FUSE_COMPAT_ATTR_OUT_SIZE 96
718 
719 struct fuse_attr_out {
720 	uint64_t	attr_valid;	/* Cache timeout for the attributes */
721 	uint32_t	attr_valid_nsec;
722 	uint32_t	dummy;
723 	struct fuse_attr attr;
724 };
725 
726 struct fuse_statx_in {
727 	uint32_t	getattr_flags;
728 	uint32_t	reserved;
729 	uint64_t	fh;
730 	uint32_t	sx_flags;
731 	uint32_t	sx_mask;
732 };
733 
734 struct fuse_statx_out {
735 	uint64_t	attr_valid;	/* Cache timeout for the attributes */
736 	uint32_t	attr_valid_nsec;
737 	uint32_t	flags;
738 	uint64_t	spare[2];
739 	struct fuse_statx stat;
740 };
741 
742 #define FUSE_COMPAT_MKNOD_IN_SIZE 8
743 
744 struct fuse_mknod_in {
745 	uint32_t	mode;
746 	uint32_t	rdev;
747 	uint32_t	umask;
748 	uint32_t	padding;
749 };
750 
751 struct fuse_mkdir_in {
752 	uint32_t	mode;
753 	uint32_t	umask;
754 };
755 
756 struct fuse_rename_in {
757 	uint64_t	newdir;
758 };
759 
760 struct fuse_rename2_in {
761 	uint64_t	newdir;
762 	uint32_t	flags;
763 	uint32_t	padding;
764 };
765 
766 struct fuse_link_in {
767 	uint64_t	oldnodeid;
768 };
769 
770 struct fuse_setattr_in {
771 	uint32_t	valid;
772 	uint32_t	padding;
773 	uint64_t	fh;
774 	uint64_t	size;
775 	uint64_t	lock_owner;
776 	uint64_t	atime;
777 	uint64_t	mtime;
778 	uint64_t	ctime;
779 	uint32_t	atimensec;
780 	uint32_t	mtimensec;
781 	uint32_t	ctimensec;
782 	uint32_t	mode;
783 	uint32_t	unused4;
784 	uint32_t	uid;
785 	uint32_t	gid;
786 	uint32_t	unused5;
787 };
788 
789 struct fuse_open_in {
790 	uint32_t	flags;
791 	uint32_t	open_flags;	/* FUSE_OPEN_... */
792 };
793 
794 struct fuse_create_in {
795 	uint32_t	flags;
796 	uint32_t	mode;
797 	uint32_t	umask;
798 	uint32_t	open_flags;	/* FUSE_OPEN_... */
799 };
800 
801 struct fuse_open_out {
802 	uint64_t	fh;
803 	uint32_t	open_flags;
804 	int32_t		backing_id;
805 };
806 
807 struct fuse_release_in {
808 	uint64_t	fh;
809 	uint32_t	flags;
810 	uint32_t	release_flags;
811 	uint64_t	lock_owner;
812 };
813 
814 struct fuse_flush_in {
815 	uint64_t	fh;
816 	uint32_t	unused;
817 	uint32_t	padding;
818 	uint64_t	lock_owner;
819 };
820 
821 struct fuse_read_in {
822 	uint64_t	fh;
823 	uint64_t	offset;
824 	uint32_t	size;
825 	uint32_t	read_flags;
826 	uint64_t	lock_owner;
827 	uint32_t	flags;
828 	uint32_t	padding;
829 };
830 
831 #define FUSE_COMPAT_WRITE_IN_SIZE 24
832 
833 struct fuse_write_in {
834 	uint64_t	fh;
835 	uint64_t	offset;
836 	uint32_t	size;
837 	uint32_t	write_flags;
838 	uint64_t	lock_owner;
839 	uint32_t	flags;
840 	uint32_t	padding;
841 };
842 
843 struct fuse_write_out {
844 	uint32_t	size;
845 	uint32_t	padding;
846 };
847 
848 #define FUSE_COMPAT_STATFS_SIZE 48
849 
850 struct fuse_statfs_out {
851 	struct fuse_kstatfs st;
852 };
853 
854 struct fuse_fsync_in {
855 	uint64_t	fh;
856 	uint32_t	fsync_flags;
857 	uint32_t	padding;
858 };
859 
860 #define FUSE_COMPAT_SETXATTR_IN_SIZE 8
861 
862 struct fuse_setxattr_in {
863 	uint32_t	size;
864 	uint32_t	flags;
865 	uint32_t	setxattr_flags;
866 	uint32_t	padding;
867 };
868 
869 struct fuse_getxattr_in {
870 	uint32_t	size;
871 	uint32_t	padding;
872 };
873 
874 struct fuse_getxattr_out {
875 	uint32_t	size;
876 	uint32_t	padding;
877 };
878 
879 struct fuse_lk_in {
880 	uint64_t	fh;
881 	uint64_t	owner;
882 	struct fuse_file_lock lk;
883 	uint32_t	lk_flags;
884 	uint32_t	padding;
885 };
886 
887 struct fuse_lk_out {
888 	struct fuse_file_lock lk;
889 };
890 
891 struct fuse_access_in {
892 	uint32_t	mask;
893 	uint32_t	padding;
894 };
895 
896 struct fuse_init_in {
897 	uint32_t	major;
898 	uint32_t	minor;
899 	uint32_t	max_readahead;
900 	uint32_t	flags;
901 	uint32_t	flags2;
902 	uint32_t	unused[11];
903 };
904 
905 #define FUSE_COMPAT_INIT_OUT_SIZE 8
906 #define FUSE_COMPAT_22_INIT_OUT_SIZE 24
907 
908 struct fuse_init_out {
909 	uint32_t	major;
910 	uint32_t	minor;
911 	uint32_t	max_readahead;
912 	uint32_t	flags;
913 	uint16_t	max_background;
914 	uint16_t	congestion_threshold;
915 	uint32_t	max_write;
916 	uint32_t	time_gran;
917 	uint16_t	max_pages;
918 	uint16_t	map_alignment;
919 	uint32_t	flags2;
920 	uint32_t	max_stack_depth;
921 	uint16_t	request_timeout;
922 	uint16_t	unused[11];
923 };
924 
925 #define CUSE_INIT_INFO_MAX 4096
926 
927 struct cuse_init_in {
928 	uint32_t	major;
929 	uint32_t	minor;
930 	uint32_t	unused;
931 	uint32_t	flags;
932 };
933 
934 struct cuse_init_out {
935 	uint32_t	major;
936 	uint32_t	minor;
937 	uint32_t	unused;
938 	uint32_t	flags;
939 	uint32_t	max_read;
940 	uint32_t	max_write;
941 	uint32_t	dev_major;		/* chardev major */
942 	uint32_t	dev_minor;		/* chardev minor */
943 	uint32_t	spare[10];
944 };
945 
946 struct fuse_interrupt_in {
947 	uint64_t	unique;
948 };
949 
950 struct fuse_bmap_in {
951 	uint64_t	block;
952 	uint32_t	blocksize;
953 	uint32_t	padding;
954 };
955 
956 struct fuse_bmap_out {
957 	uint64_t	block;
958 };
959 
960 struct fuse_ioctl_in {
961 	uint64_t	fh;
962 	uint32_t	flags;
963 	uint32_t	cmd;
964 	uint64_t	arg;
965 	uint32_t	in_size;
966 	uint32_t	out_size;
967 };
968 
969 struct fuse_ioctl_iovec {
970 	uint64_t	base;
971 	uint64_t	len;
972 };
973 
974 struct fuse_ioctl_out {
975 	int32_t		result;
976 	uint32_t	flags;
977 	uint32_t	in_iovs;
978 	uint32_t	out_iovs;
979 };
980 
981 struct fuse_poll_in {
982 	uint64_t	fh;
983 	uint64_t	kh;
984 	uint32_t	flags;
985 	uint32_t	events;
986 };
987 
988 struct fuse_poll_out {
989 	uint32_t	revents;
990 	uint32_t	padding;
991 };
992 
993 struct fuse_notify_poll_wakeup_out {
994 	uint64_t	kh;
995 };
996 
997 struct fuse_fallocate_in {
998 	uint64_t	fh;
999 	uint64_t	offset;
1000 	uint64_t	length;
1001 	uint32_t	mode;
1002 	uint32_t	padding;
1003 };
1004 
1005 /**
1006  * FUSE request unique ID flag
1007  *
1008  * Indicates whether this is a resend request. The receiver should handle this
1009  * request accordingly.
1010  */
1011 #define FUSE_UNIQUE_RESEND (1ULL << 63)
1012 
1013 /**
1014  * This value will be set by the kernel to
1015  * (struct fuse_in_header).{uid,gid} fields in
1016  * case when:
1017  * - fuse daemon enabled FUSE_ALLOW_IDMAP
1018  * - idmapping information is not available and uid/gid
1019  *   can not be mapped in accordance with an idmapping.
1020  *
1021  * Note: an idmapping information always available
1022  * for inode creation operations like:
1023  * FUSE_MKNOD, FUSE_SYMLINK, FUSE_MKDIR, FUSE_TMPFILE,
1024  * FUSE_CREATE and FUSE_RENAME2 (with RENAME_WHITEOUT).
1025  */
1026 #define FUSE_INVALID_UIDGID ((uint32_t)(-1))
1027 
1028 struct fuse_in_header {
1029 	uint32_t	len;
1030 	uint32_t	opcode;
1031 	uint64_t	unique;
1032 	uint64_t	nodeid;
1033 	uint32_t	uid;
1034 	uint32_t	gid;
1035 	uint32_t	pid;
1036 	uint16_t	total_extlen; /* length of extensions in 8byte units */
1037 	uint16_t	padding;
1038 };
1039 
1040 struct fuse_out_header {
1041 	uint32_t	len;
1042 	int32_t		error;
1043 	uint64_t	unique;
1044 };
1045 
1046 struct fuse_dirent {
1047 	uint64_t	ino;
1048 	uint64_t	off;
1049 	uint32_t	namelen;
1050 	uint32_t	type;
1051 	char name[];
1052 };
1053 
1054 /* Align variable length records to 64bit boundary */
1055 #define FUSE_REC_ALIGN(x) \
1056 	(((x) + sizeof(uint64_t) - 1) & ~(sizeof(uint64_t) - 1))
1057 
1058 #define FUSE_NAME_OFFSET offsetof(struct fuse_dirent, name)
1059 #define FUSE_DIRENT_ALIGN(x) FUSE_REC_ALIGN(x)
1060 #define FUSE_DIRENT_SIZE(d) \
1061 	FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)
1062 
1063 struct fuse_direntplus {
1064 	struct fuse_entry_out entry_out;
1065 	struct fuse_dirent dirent;
1066 };
1067 
1068 #define FUSE_NAME_OFFSET_DIRENTPLUS \
1069 	offsetof(struct fuse_direntplus, dirent.name)
1070 #define FUSE_DIRENTPLUS_SIZE(d) \
1071 	FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET_DIRENTPLUS + (d)->dirent.namelen)
1072 
1073 struct fuse_notify_inval_inode_out {
1074 	uint64_t	ino;
1075 	int64_t		off;
1076 	int64_t		len;
1077 };
1078 
1079 struct fuse_notify_inval_entry_out {
1080 	uint64_t	parent;
1081 	uint32_t	namelen;
1082 	uint32_t	flags;
1083 };
1084 
1085 struct fuse_notify_delete_out {
1086 	uint64_t	parent;
1087 	uint64_t	child;
1088 	uint32_t	namelen;
1089 	uint32_t	padding;
1090 };
1091 
1092 struct fuse_notify_store_out {
1093 	uint64_t	nodeid;
1094 	uint64_t	offset;
1095 	uint32_t	size;
1096 	uint32_t	padding;
1097 };
1098 
1099 struct fuse_notify_retrieve_out {
1100 	uint64_t	notify_unique;
1101 	uint64_t	nodeid;
1102 	uint64_t	offset;
1103 	uint32_t	size;
1104 	uint32_t	padding;
1105 };
1106 
1107 /* Matches the size of fuse_write_in */
1108 struct fuse_notify_retrieve_in {
1109 	uint64_t	dummy1;
1110 	uint64_t	offset;
1111 	uint32_t	size;
1112 	uint32_t	dummy2;
1113 	uint64_t	dummy3;
1114 	uint64_t	dummy4;
1115 };
1116 
1117 struct fuse_backing_map {
1118 	int32_t		fd;
1119 	uint32_t	flags;
1120 	uint64_t	padding;
1121 };
1122 
1123 /* Device ioctls: */
1124 #define FUSE_DEV_IOC_MAGIC		229
1125 #define FUSE_DEV_IOC_CLONE		_IOR(FUSE_DEV_IOC_MAGIC, 0, uint32_t)
1126 #define FUSE_DEV_IOC_BACKING_OPEN	_IOW(FUSE_DEV_IOC_MAGIC, 1, \
1127 					     struct fuse_backing_map)
1128 #define FUSE_DEV_IOC_BACKING_CLOSE	_IOW(FUSE_DEV_IOC_MAGIC, 2, uint32_t)
1129 
1130 struct fuse_lseek_in {
1131 	uint64_t	fh;
1132 	uint64_t	offset;
1133 	uint32_t	whence;
1134 	uint32_t	padding;
1135 };
1136 
1137 struct fuse_lseek_out {
1138 	uint64_t	offset;
1139 };
1140 
1141 struct fuse_copy_file_range_in {
1142 	uint64_t	fh_in;
1143 	uint64_t	off_in;
1144 	uint64_t	nodeid_out;
1145 	uint64_t	fh_out;
1146 	uint64_t	off_out;
1147 	uint64_t	len;
1148 	uint64_t	flags;
1149 };
1150 
1151 #define FUSE_SETUPMAPPING_FLAG_WRITE (1ull << 0)
1152 #define FUSE_SETUPMAPPING_FLAG_READ (1ull << 1)
1153 struct fuse_setupmapping_in {
1154 	/* An already open handle */
1155 	uint64_t	fh;
1156 	/* Offset into the file to start the mapping */
1157 	uint64_t	foffset;
1158 	/* Length of mapping required */
1159 	uint64_t	len;
1160 	/* Flags, FUSE_SETUPMAPPING_FLAG_* */
1161 	uint64_t	flags;
1162 	/* Offset in Memory Window */
1163 	uint64_t	moffset;
1164 };
1165 
1166 struct fuse_removemapping_in {
1167 	/* number of fuse_removemapping_one follows */
1168 	uint32_t        count;
1169 };
1170 
1171 struct fuse_removemapping_one {
1172 	/* Offset into the dax window start the unmapping */
1173 	uint64_t        moffset;
1174 	/* Length of mapping required */
1175 	uint64_t	len;
1176 };
1177 
1178 #define FUSE_REMOVEMAPPING_MAX_ENTRY   \
1179 		(PAGE_SIZE / sizeof(struct fuse_removemapping_one))
1180 
1181 struct fuse_syncfs_in {
1182 	uint64_t	padding;
1183 };
1184 
1185 /*
1186  * For each security context, send fuse_secctx with size of security context
1187  * fuse_secctx will be followed by security context name and this in turn
1188  * will be followed by actual context label.
1189  * fuse_secctx, name, context
1190  */
1191 struct fuse_secctx {
1192 	uint32_t	size;
1193 	uint32_t	padding;
1194 };
1195 
1196 /*
1197  * Contains the information about how many fuse_secctx structures are being
1198  * sent and what's the total size of all security contexts (including
1199  * size of fuse_secctx_header).
1200  *
1201  */
1202 struct fuse_secctx_header {
1203 	uint32_t	size;
1204 	uint32_t	nr_secctx;
1205 };
1206 
1207 /**
1208  * struct fuse_ext_header - extension header
1209  * @size: total size of this extension including this header
1210  * @type: type of extension
1211  *
1212  * This is made compatible with fuse_secctx_header by using type values >
1213  * FUSE_MAX_NR_SECCTX
1214  */
1215 struct fuse_ext_header {
1216 	uint32_t	size;
1217 	uint32_t	type;
1218 };
1219 
1220 /**
1221  * struct fuse_supp_groups - Supplementary group extension
1222  * @nr_groups: number of supplementary groups
1223  * @groups: flexible array of group IDs
1224  */
1225 struct fuse_supp_groups {
1226 	uint32_t	nr_groups;
1227 	uint32_t	groups[];
1228 };
1229 
1230 /**
1231  * Size of the ring buffer header
1232  */
1233 #define FUSE_URING_IN_OUT_HEADER_SZ 128
1234 #define FUSE_URING_OP_IN_OUT_SZ 128
1235 
1236 /* Used as part of the fuse_uring_req_header */
1237 struct fuse_uring_ent_in_out {
1238 	uint64_t flags;
1239 
1240 	/*
1241 	 * commit ID to be used in a reply to a ring request (see also
1242 	 * struct fuse_uring_cmd_req)
1243 	 */
1244 	uint64_t commit_id;
1245 
1246 	/* size of user payload buffer */
1247 	uint32_t payload_sz;
1248 	uint32_t padding;
1249 
1250 	uint64_t reserved;
1251 };
1252 
1253 /**
1254  * Header for all fuse-io-uring requests
1255  */
1256 struct fuse_uring_req_header {
1257 	/* struct fuse_in_header / struct fuse_out_header */
1258 	char in_out[FUSE_URING_IN_OUT_HEADER_SZ];
1259 
1260 	/* per op code header */
1261 	char op_in[FUSE_URING_OP_IN_OUT_SZ];
1262 
1263 	struct fuse_uring_ent_in_out ring_ent_in_out;
1264 };
1265 
1266 /**
1267  * sqe commands to the kernel
1268  */
1269 enum fuse_uring_cmd {
1270 	FUSE_IO_URING_CMD_INVALID = 0,
1271 
1272 	/* register the request buffer and fetch a fuse request */
1273 	FUSE_IO_URING_CMD_REGISTER = 1,
1274 
1275 	/* commit fuse request result and fetch next request */
1276 	FUSE_IO_URING_CMD_COMMIT_AND_FETCH = 2,
1277 };
1278 
1279 /**
1280  * In the 80B command area of the SQE.
1281  */
1282 struct fuse_uring_cmd_req {
1283 	uint64_t flags;
1284 
1285 	/* entry identifier for commits */
1286 	uint64_t commit_id;
1287 
1288 	/* queue the command is for (queue index) */
1289 	uint16_t qid;
1290 	uint8_t padding[6];
1291 };
1292 
1293 #endif /* _LINUX_FUSE_H */
1294