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nbd  3.2
nbd.h
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00001 /*
00002  * 1999 Copyright (C) Pavel Machek, pavel@ucw.cz. This code is GPL.
00003  * 1999/11/04 Copyright (C) 1999 VMware, Inc. (Regis "HPReg" Duchesne)
00004  *            Made nbd_end_request() use the io_request_lock
00005  * 2001 Copyright (C) Steven Whitehouse
00006  *            New nbd_end_request() for compatibility with new linux block
00007  *            layer code.
00008  * 2003/06/24 Louis D. Langholtz <ldl@aros.net>
00009  *            Removed unneeded blksize_bits field from nbd_device struct.
00010  *            Cleanup PARANOIA usage & code.
00011  * 2004/02/19 Paul Clements
00012  *            Removed PARANOIA, plus various cleanup and comments
00013  */
00014 
00015 #ifndef LINUX_NBD_H
00016 #define LINUX_NBD_H
00017 
00018 //#include <linux/types.h>
00019 
00020 #define NBD_SET_SOCK _IO( 0xab, 0 )
00021 #define NBD_SET_BLKSIZE     _IO( 0xab, 1 )
00022 #define NBD_SET_SIZE _IO( 0xab, 2 )
00023 #define NBD_DO_IT    _IO( 0xab, 3 )
00024 #define NBD_CLEAR_SOCK      _IO( 0xab, 4 )
00025 #define NBD_CLEAR_QUE       _IO( 0xab, 5 )
00026 #define NBD_PRINT_DEBUG     _IO( 0xab, 6 )
00027 #define NBD_SET_SIZE_BLOCKS _IO( 0xab, 7 )
00028 #define NBD_DISCONNECT  _IO( 0xab, 8 )
00029 #define NBD_SET_TIMEOUT _IO( 0xab, 9 )
00030 #define NBD_SET_FLAGS _IO( 0xab, 10 )
00031 
00032 enum {
00033        NBD_CMD_READ = 0,
00034        NBD_CMD_WRITE = 1,
00035        NBD_CMD_DISC = 2,
00036        NBD_CMD_FLUSH = 3,
00037        NBD_CMD_TRIM = 4
00038 };
00039 
00040 #define NBD_CMD_MASK_COMMAND 0x0000ffff
00041 #define NBD_CMD_FLAG_FUA (1<<16)
00042 
00043 /* values for flags field */
00044 #define NBD_FLAG_HAS_FLAGS  (1 << 0)      /* Flags are there */
00045 #define NBD_FLAG_READ_ONLY  (1 << 1)      /* Device is read-only */
00046 #define NBD_FLAG_SEND_FLUSH (1 << 2)      /* Send FLUSH */
00047 #define NBD_FLAG_SEND_FUA   (1 << 3)      /* Send FUA (Force Unit Access) */
00048 #define NBD_FLAG_ROTATIONAL (1 << 4)      /* Use elevator algorithm - rotational media */
00049 #define NBD_FLAG_SEND_TRIM  (1 << 5)      /* Send TRIM (discard) */
00050 
00051 #define nbd_cmd(req) ((req)->cmd[0])
00052 
00053 /* userspace doesn't need the nbd_device structure */
00054 
00055 /* These are sent over the network in the request/reply magic fields */
00056 
00057 #define NBD_REQUEST_MAGIC 0x25609513
00058 #define NBD_REPLY_MAGIC 0x67446698
00059 /* Do *not* use magics: 0x12560953 0x96744668. */
00060 
00061 /*
00062  * This is the packet used for communication between client and
00063  * server. All data are in network byte order.
00064  */
00065 struct nbd_request {
00066        __be32 magic;
00067        __be32 type;  /* == READ || == WRITE      */
00068        char handle[8];
00069        __be64 from;
00070        __be32 len;
00071 } __attribute__ ((packed));
00072 
00073 /*
00074  * This is the reply packet that nbd-server sends back to the client after
00075  * it has completed an I/O request (or an error occurs).
00076  */
00077 struct nbd_reply {
00078        __be32 magic;
00079        __be32 error;        /* 0 = ok, else error       */
00080        char handle[8];             /* handle you got from request     */
00081 };
00082 #endif