Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. This code is GPL.
3 * 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
4 * Made nbd_end_request() use the io_request_lock
5 * 2001 Copyright (C) Steven Whitehouse
6 * New nbd_end_request() for compatibility with new linux block
7 * layer code.
8 * 2003/06/24 Louis D. Langholtz <ldl@aros.net>
9 * Removed unneeded blksize_bits field from nbd_device struct.
10 * Cleanup PARANOIA usage & code.
11 * 2004/02/19 Paul Clements
12 * Removed PARANOIA, plus various cleanup and comments
13 */
14
15#ifndef LINUX_NBD_H
16#define LINUX_NBD_H
17
18#define NBD_SET_SOCK _IO( 0xab, 0 )
19#define NBD_SET_BLKSIZE _IO( 0xab, 1 )
20#define NBD_SET_SIZE _IO( 0xab, 2 )
21#define NBD_DO_IT _IO( 0xab, 3 )
22#define NBD_CLEAR_SOCK _IO( 0xab, 4 )
23#define NBD_CLEAR_QUE _IO( 0xab, 5 )
24#define NBD_PRINT_DEBUG _IO( 0xab, 6 )
25#define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )
26#define NBD_DISCONNECT _IO( 0xab, 8 )
27
28enum {
29 NBD_CMD_READ = 0,
30 NBD_CMD_WRITE = 1,
31 NBD_CMD_DISC = 2
32};
33
34#define nbd_cmd(req) ((req)->cmd[0])
35#define MAX_NBD 128
36
37/* userspace doesn't need the nbd_device structure */
38#ifdef __KERNEL__
39
40#include <linux/wait.h>
41
42/* values for flags field */
43#define NBD_READ_ONLY 0x0001
44#define NBD_WRITE_NOCHK 0x0002
45
46struct request;
47
48struct nbd_device {
49 int flags;
50 int harderror; /* Code of hard error */
51 struct socket * sock;
52 struct file * file; /* If == NULL, device is not ready, yet */
53 int magic;
54
55 spinlock_t queue_lock;
56 struct list_head queue_head;/* Requests are added here... */
57 struct request *active_req;
58 wait_queue_head_t active_wq;
59
60 struct semaphore tx_lock;
61 struct gendisk *disk;
62 int blksize;
63 u64 bytesize;
64};
65
66#endif
67
68/* These are sent over the network in the request/reply magic fields */
69
70#define NBD_REQUEST_MAGIC 0x25609513
71#define NBD_REPLY_MAGIC 0x67446698
72/* Do *not* use magics: 0x12560953 0x96744668. */
73
74/*
75 * This is the packet used for communication between client and
76 * server. All data are in network byte order.
77 */
78struct nbd_request {
79 u32 magic;
80 u32 type; /* == READ || == WRITE */
81 char handle[8];
82 u64 from;
83 u32 len;
84}
85#ifdef __GNUC__
86 __attribute__ ((packed))
87#endif
88;
89
90/*
91 * This is the reply packet that nbd-server sends back to the client after
92 * it has completed an I/O request (or an error occurs).
93 */
94struct nbd_reply {
95 u32 magic;
96 u32 error; /* 0 = ok, else error */
97 char handle[8]; /* handle you got from request */
98};
99#endif