xref: /OK3568_Linux_fs/kernel/include/uapi/linux/nbd.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-1.0+ WITH Linux-syscall-note */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. This code is GPL.
4*4882a593Smuzhiyun  * 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
5*4882a593Smuzhiyun  *            Made nbd_end_request() use the io_request_lock
6*4882a593Smuzhiyun  * 2001 Copyright (C) Steven Whitehouse
7*4882a593Smuzhiyun  *            New nbd_end_request() for compatibility with new linux block
8*4882a593Smuzhiyun  *            layer code.
9*4882a593Smuzhiyun  * 2003/06/24 Louis D. Langholtz <ldl@aros.net>
10*4882a593Smuzhiyun  *            Removed unneeded blksize_bits field from nbd_device struct.
11*4882a593Smuzhiyun  *            Cleanup PARANOIA usage & code.
12*4882a593Smuzhiyun  * 2004/02/19 Paul Clements
13*4882a593Smuzhiyun  *            Removed PARANOIA, plus various cleanup and comments
14*4882a593Smuzhiyun  */
15*4882a593Smuzhiyun 
16*4882a593Smuzhiyun #ifndef _UAPILINUX_NBD_H
17*4882a593Smuzhiyun #define _UAPILINUX_NBD_H
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun #include <linux/types.h>
20*4882a593Smuzhiyun 
21*4882a593Smuzhiyun #define NBD_SET_SOCK	_IO( 0xab, 0 )
22*4882a593Smuzhiyun #define NBD_SET_BLKSIZE	_IO( 0xab, 1 )
23*4882a593Smuzhiyun #define NBD_SET_SIZE	_IO( 0xab, 2 )
24*4882a593Smuzhiyun #define NBD_DO_IT	_IO( 0xab, 3 )
25*4882a593Smuzhiyun #define NBD_CLEAR_SOCK	_IO( 0xab, 4 )
26*4882a593Smuzhiyun #define NBD_CLEAR_QUE	_IO( 0xab, 5 )
27*4882a593Smuzhiyun #define NBD_PRINT_DEBUG	_IO( 0xab, 6 )
28*4882a593Smuzhiyun #define NBD_SET_SIZE_BLOCKS	_IO( 0xab, 7 )
29*4882a593Smuzhiyun #define NBD_DISCONNECT  _IO( 0xab, 8 )
30*4882a593Smuzhiyun #define NBD_SET_TIMEOUT _IO( 0xab, 9 )
31*4882a593Smuzhiyun #define NBD_SET_FLAGS   _IO( 0xab, 10)
32*4882a593Smuzhiyun 
33*4882a593Smuzhiyun enum {
34*4882a593Smuzhiyun 	NBD_CMD_READ = 0,
35*4882a593Smuzhiyun 	NBD_CMD_WRITE = 1,
36*4882a593Smuzhiyun 	NBD_CMD_DISC = 2,
37*4882a593Smuzhiyun 	NBD_CMD_FLUSH = 3,
38*4882a593Smuzhiyun 	NBD_CMD_TRIM = 4
39*4882a593Smuzhiyun };
40*4882a593Smuzhiyun 
41*4882a593Smuzhiyun /* values for flags field, these are server interaction specific. */
42*4882a593Smuzhiyun #define NBD_FLAG_HAS_FLAGS	(1 << 0) /* nbd-server supports flags */
43*4882a593Smuzhiyun #define NBD_FLAG_READ_ONLY	(1 << 1) /* device is read-only */
44*4882a593Smuzhiyun #define NBD_FLAG_SEND_FLUSH	(1 << 2) /* can flush writeback cache */
45*4882a593Smuzhiyun #define NBD_FLAG_SEND_FUA	(1 << 3) /* send FUA (forced unit access) */
46*4882a593Smuzhiyun /* there is a gap here to match userspace */
47*4882a593Smuzhiyun #define NBD_FLAG_SEND_TRIM	(1 << 5) /* send trim/discard */
48*4882a593Smuzhiyun #define NBD_FLAG_CAN_MULTI_CONN	(1 << 8)	/* Server supports multiple connections per export. */
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun /* values for cmd flags in the upper 16 bits of request type */
51*4882a593Smuzhiyun #define NBD_CMD_FLAG_FUA	(1 << 16) /* FUA (forced unit access) op */
52*4882a593Smuzhiyun 
53*4882a593Smuzhiyun /* These are client behavior specific flags. */
54*4882a593Smuzhiyun #define NBD_CFLAG_DESTROY_ON_DISCONNECT	(1 << 0) /* delete the nbd device on
55*4882a593Smuzhiyun 						    disconnect. */
56*4882a593Smuzhiyun #define NBD_CFLAG_DISCONNECT_ON_CLOSE (1 << 1) /* disconnect the nbd device on
57*4882a593Smuzhiyun 						*  close by last opener.
58*4882a593Smuzhiyun 						*/
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun /* userspace doesn't need the nbd_device structure */
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun /* These are sent over the network in the request/reply magic fields */
63*4882a593Smuzhiyun 
64*4882a593Smuzhiyun #define NBD_REQUEST_MAGIC 0x25609513
65*4882a593Smuzhiyun #define NBD_REPLY_MAGIC 0x67446698
66*4882a593Smuzhiyun /* Do *not* use magics: 0x12560953 0x96744668. */
67*4882a593Smuzhiyun 
68*4882a593Smuzhiyun /*
69*4882a593Smuzhiyun  * This is the packet used for communication between client and
70*4882a593Smuzhiyun  * server. All data are in network byte order.
71*4882a593Smuzhiyun  */
72*4882a593Smuzhiyun struct nbd_request {
73*4882a593Smuzhiyun 	__be32 magic;
74*4882a593Smuzhiyun 	__be32 type;	/* == READ || == WRITE 	*/
75*4882a593Smuzhiyun 	char handle[8];
76*4882a593Smuzhiyun 	__be64 from;
77*4882a593Smuzhiyun 	__be32 len;
78*4882a593Smuzhiyun } __attribute__((packed));
79*4882a593Smuzhiyun 
80*4882a593Smuzhiyun /*
81*4882a593Smuzhiyun  * This is the reply packet that nbd-server sends back to the client after
82*4882a593Smuzhiyun  * it has completed an I/O request (or an error occurs).
83*4882a593Smuzhiyun  */
84*4882a593Smuzhiyun struct nbd_reply {
85*4882a593Smuzhiyun 	__be32 magic;
86*4882a593Smuzhiyun 	__be32 error;		/* 0 = ok, else error	*/
87*4882a593Smuzhiyun 	char handle[8];		/* handle you got from request	*/
88*4882a593Smuzhiyun };
89*4882a593Smuzhiyun #endif /* _UAPILINUX_NBD_H */
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