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1 | 75818250 | ths | /*
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2 | 75818250 | ths | * QEMU Block driver for NBD
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3 | 75818250 | ths | *
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4 | 75818250 | ths | * Copyright (C) 2008 Bull S.A.S.
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5 | bd5921b4 | malc | * Author: Laurent Vivier <Laurent.Vivier@bull.net>
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6 | 75818250 | ths | *
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7 | 75818250 | ths | * Some parts:
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8 | 75818250 | ths | * Copyright (C) 2007 Anthony Liguori <anthony@codemonkey.ws>
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9 | 75818250 | ths | *
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10 | 75818250 | ths | * Permission is hereby granted, free of charge, to any person obtaining a copy
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11 | 75818250 | ths | * of this software and associated documentation files (the "Software"), to deal
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12 | 75818250 | ths | * in the Software without restriction, including without limitation the rights
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13 | 75818250 | ths | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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14 | 75818250 | ths | * copies of the Software, and to permit persons to whom the Software is
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15 | 75818250 | ths | * furnished to do so, subject to the following conditions:
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16 | 75818250 | ths | *
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17 | 75818250 | ths | * The above copyright notice and this permission notice shall be included in
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18 | 75818250 | ths | * all copies or substantial portions of the Software.
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19 | 75818250 | ths | *
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20 | 75818250 | ths | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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21 | 75818250 | ths | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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22 | 75818250 | ths | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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23 | 75818250 | ths | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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24 | 75818250 | ths | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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25 | 75818250 | ths | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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26 | 75818250 | ths | * THE SOFTWARE.
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27 | 75818250 | ths | */
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28 | 75818250 | ths | |
29 | 75818250 | ths | #include "qemu-common.h" |
30 | 75818250 | ths | #include "nbd.h" |
31 | 5efa9d5a | Anthony Liguori | #include "module.h" |
32 | 33897dc7 | Nick Thomas | #include "qemu_socket.h" |
33 | 75818250 | ths | |
34 | 75818250 | ths | #include <sys/types.h> |
35 | 75818250 | ths | #include <unistd.h> |
36 | 75818250 | ths | |
37 | 1d45f8b5 | Laurent Vivier | #define EN_OPTSTR ":exportname=" |
38 | 1d45f8b5 | Laurent Vivier | |
39 | 33897dc7 | Nick Thomas | /* #define DEBUG_NBD */
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40 | 33897dc7 | Nick Thomas | |
41 | 33897dc7 | Nick Thomas | #if defined(DEBUG_NBD)
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42 | 33897dc7 | Nick Thomas | #define logout(fmt, ...) \
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43 | 33897dc7 | Nick Thomas | fprintf(stderr, "nbd\t%-24s" fmt, __func__, ##__VA_ARGS__) |
44 | 33897dc7 | Nick Thomas | #else
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45 | 33897dc7 | Nick Thomas | #define logout(fmt, ...) ((void)0) |
46 | 33897dc7 | Nick Thomas | #endif
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47 | 33897dc7 | Nick Thomas | |
48 | 75818250 | ths | typedef struct BDRVNBDState { |
49 | 75818250 | ths | int sock;
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50 | 75818250 | ths | off_t size; |
51 | 75818250 | ths | size_t blocksize; |
52 | 33897dc7 | Nick Thomas | char *export_name; /* An NBD server may export several devices */ |
53 | 33897dc7 | Nick Thomas | |
54 | 33897dc7 | Nick Thomas | /* If it begins with '/', this is a UNIX domain socket. Otherwise,
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55 | 33897dc7 | Nick Thomas | * it's a string of the form <hostname|ip4|\[ip6\]>:port
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56 | 33897dc7 | Nick Thomas | */
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57 | 33897dc7 | Nick Thomas | char *host_spec;
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58 | 75818250 | ths | } BDRVNBDState; |
59 | 75818250 | ths | |
60 | 33897dc7 | Nick Thomas | static int nbd_config(BDRVNBDState *s, const char *filename, int flags) |
61 | 75818250 | ths | { |
62 | 1d45f8b5 | Laurent Vivier | char *file;
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63 | 33897dc7 | Nick Thomas | char *export_name;
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64 | 33897dc7 | Nick Thomas | const char *host_spec; |
65 | 75818250 | ths | const char *unixpath; |
66 | 1d45f8b5 | Laurent Vivier | int err = -EINVAL;
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67 | 75818250 | ths | |
68 | 1d45f8b5 | Laurent Vivier | file = qemu_strdup(filename); |
69 | 1d45f8b5 | Laurent Vivier | |
70 | 33897dc7 | Nick Thomas | export_name = strstr(file, EN_OPTSTR); |
71 | 33897dc7 | Nick Thomas | if (export_name) {
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72 | 33897dc7 | Nick Thomas | if (export_name[strlen(EN_OPTSTR)] == 0) { |
73 | 1d45f8b5 | Laurent Vivier | goto out;
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74 | 1d45f8b5 | Laurent Vivier | } |
75 | 33897dc7 | Nick Thomas | export_name[0] = 0; /* truncate 'file' */ |
76 | 33897dc7 | Nick Thomas | export_name += strlen(EN_OPTSTR); |
77 | 33897dc7 | Nick Thomas | s->export_name = qemu_strdup(export_name); |
78 | 1d45f8b5 | Laurent Vivier | } |
79 | 1d45f8b5 | Laurent Vivier | |
80 | 33897dc7 | Nick Thomas | /* extract the host_spec - fail if it's not nbd:... */
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81 | 33897dc7 | Nick Thomas | if (!strstart(file, "nbd:", &host_spec)) { |
82 | 1d45f8b5 | Laurent Vivier | goto out;
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83 | 1d45f8b5 | Laurent Vivier | } |
84 | 75818250 | ths | |
85 | 33897dc7 | Nick Thomas | /* are we a UNIX or TCP socket? */
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86 | 33897dc7 | Nick Thomas | if (strstart(host_spec, "unix:", &unixpath)) { |
87 | 33897dc7 | Nick Thomas | if (unixpath[0] != '/') { /* We demand an absolute path*/ |
88 | 1d45f8b5 | Laurent Vivier | goto out;
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89 | 1d45f8b5 | Laurent Vivier | } |
90 | 33897dc7 | Nick Thomas | s->host_spec = qemu_strdup(unixpath); |
91 | 75818250 | ths | } else {
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92 | 33897dc7 | Nick Thomas | s->host_spec = qemu_strdup(host_spec); |
93 | 33897dc7 | Nick Thomas | } |
94 | 75818250 | ths | |
95 | 33897dc7 | Nick Thomas | err = 0;
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96 | 75818250 | ths | |
97 | 33897dc7 | Nick Thomas | out:
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98 | 33897dc7 | Nick Thomas | qemu_free(file); |
99 | 33897dc7 | Nick Thomas | if (err != 0) { |
100 | 33897dc7 | Nick Thomas | qemu_free(s->export_name); |
101 | 33897dc7 | Nick Thomas | qemu_free(s->host_spec); |
102 | 33897dc7 | Nick Thomas | } |
103 | 33897dc7 | Nick Thomas | return err;
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104 | 33897dc7 | Nick Thomas | } |
105 | 1d45f8b5 | Laurent Vivier | |
106 | 33897dc7 | Nick Thomas | static int nbd_establish_connection(BlockDriverState *bs) |
107 | 33897dc7 | Nick Thomas | { |
108 | 33897dc7 | Nick Thomas | BDRVNBDState *s = bs->opaque; |
109 | 33897dc7 | Nick Thomas | int sock;
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110 | 33897dc7 | Nick Thomas | int ret;
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111 | 33897dc7 | Nick Thomas | off_t size; |
112 | 33897dc7 | Nick Thomas | size_t blocksize; |
113 | 33897dc7 | Nick Thomas | uint32_t nbdflags; |
114 | 75818250 | ths | |
115 | 33897dc7 | Nick Thomas | if (s->host_spec[0] == '/') { |
116 | 33897dc7 | Nick Thomas | sock = unix_socket_outgoing(s->host_spec); |
117 | 33897dc7 | Nick Thomas | } else {
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118 | 33897dc7 | Nick Thomas | sock = tcp_socket_outgoing_spec(s->host_spec); |
119 | 75818250 | ths | } |
120 | 75818250 | ths | |
121 | 33897dc7 | Nick Thomas | /* Failed to establish connection */
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122 | 1d45f8b5 | Laurent Vivier | if (sock == -1) { |
123 | 33897dc7 | Nick Thomas | logout("Failed to establish connection to NBD server\n");
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124 | 33897dc7 | Nick Thomas | return -errno;
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125 | 1d45f8b5 | Laurent Vivier | } |
126 | 75818250 | ths | |
127 | 33897dc7 | Nick Thomas | /* NBD handshake */
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128 | 33897dc7 | Nick Thomas | ret = nbd_receive_negotiate(sock, s->export_name, &nbdflags, &size, |
129 | 33897dc7 | Nick Thomas | &blocksize); |
130 | 1d45f8b5 | Laurent Vivier | if (ret == -1) { |
131 | 33897dc7 | Nick Thomas | logout("Failed to negotiate with the NBD server\n");
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132 | 33897dc7 | Nick Thomas | closesocket(sock); |
133 | 33897dc7 | Nick Thomas | return -errno;
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134 | 1d45f8b5 | Laurent Vivier | } |
135 | 75818250 | ths | |
136 | 33897dc7 | Nick Thomas | /* Now that we're connected, set the socket to be non-blocking */
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137 | 33897dc7 | Nick Thomas | socket_set_nonblock(sock); |
138 | 33897dc7 | Nick Thomas | |
139 | 75818250 | ths | s->sock = sock; |
140 | 75818250 | ths | s->size = size; |
141 | 75818250 | ths | s->blocksize = blocksize; |
142 | 75818250 | ths | |
143 | 33897dc7 | Nick Thomas | logout("Established connection with NBD server\n");
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144 | 33897dc7 | Nick Thomas | return 0; |
145 | 33897dc7 | Nick Thomas | } |
146 | 33897dc7 | Nick Thomas | |
147 | 33897dc7 | Nick Thomas | static void nbd_teardown_connection(BlockDriverState *bs) |
148 | 33897dc7 | Nick Thomas | { |
149 | 33897dc7 | Nick Thomas | BDRVNBDState *s = bs->opaque; |
150 | 33897dc7 | Nick Thomas | struct nbd_request request;
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151 | 33897dc7 | Nick Thomas | |
152 | 33897dc7 | Nick Thomas | request.type = NBD_CMD_DISC; |
153 | 33897dc7 | Nick Thomas | request.handle = (uint64_t)(intptr_t)bs; |
154 | 33897dc7 | Nick Thomas | request.from = 0;
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155 | 33897dc7 | Nick Thomas | request.len = 0;
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156 | 33897dc7 | Nick Thomas | nbd_send_request(s->sock, &request); |
157 | 33897dc7 | Nick Thomas | |
158 | 33897dc7 | Nick Thomas | closesocket(s->sock); |
159 | 33897dc7 | Nick Thomas | } |
160 | 33897dc7 | Nick Thomas | |
161 | 33897dc7 | Nick Thomas | static int nbd_open(BlockDriverState *bs, const char* filename, int flags) |
162 | 33897dc7 | Nick Thomas | { |
163 | 33897dc7 | Nick Thomas | BDRVNBDState *s = bs->opaque; |
164 | 33897dc7 | Nick Thomas | int result;
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165 | 33897dc7 | Nick Thomas | |
166 | 33897dc7 | Nick Thomas | /* Pop the config into our state object. Exit if invalid. */
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167 | 33897dc7 | Nick Thomas | result = nbd_config(s, filename, flags); |
168 | 33897dc7 | Nick Thomas | if (result != 0) { |
169 | 33897dc7 | Nick Thomas | return result;
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170 | 33897dc7 | Nick Thomas | } |
171 | 33897dc7 | Nick Thomas | |
172 | 33897dc7 | Nick Thomas | /* establish TCP connection, return error if it fails
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173 | 33897dc7 | Nick Thomas | * TODO: Configurable retry-until-timeout behaviour.
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174 | 33897dc7 | Nick Thomas | */
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175 | 33897dc7 | Nick Thomas | result = nbd_establish_connection(bs); |
176 | 33897dc7 | Nick Thomas | |
177 | 33897dc7 | Nick Thomas | return result;
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178 | 75818250 | ths | } |
179 | 75818250 | ths | |
180 | 75818250 | ths | static int nbd_read(BlockDriverState *bs, int64_t sector_num, |
181 | 75818250 | ths | uint8_t *buf, int nb_sectors)
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182 | 75818250 | ths | { |
183 | 75818250 | ths | BDRVNBDState *s = bs->opaque; |
184 | 75818250 | ths | struct nbd_request request;
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185 | 75818250 | ths | struct nbd_reply reply;
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186 | 75818250 | ths | |
187 | 75818250 | ths | request.type = NBD_CMD_READ; |
188 | 75818250 | ths | request.handle = (uint64_t)(intptr_t)bs; |
189 | 75818250 | ths | request.from = sector_num * 512;;
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190 | 75818250 | ths | request.len = nb_sectors * 512;
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191 | 75818250 | ths | |
192 | 75818250 | ths | if (nbd_send_request(s->sock, &request) == -1) |
193 | 75818250 | ths | return -errno;
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194 | 75818250 | ths | |
195 | 75818250 | ths | if (nbd_receive_reply(s->sock, &reply) == -1) |
196 | 75818250 | ths | return -errno;
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197 | 75818250 | ths | |
198 | 75818250 | ths | if (reply.error !=0) |
199 | 75818250 | ths | return -reply.error;
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200 | 75818250 | ths | |
201 | 75818250 | ths | if (reply.handle != request.handle)
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202 | 75818250 | ths | return -EIO;
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203 | 75818250 | ths | |
204 | 75818250 | ths | if (nbd_wr_sync(s->sock, buf, request.len, 1) != request.len) |
205 | 75818250 | ths | return -EIO;
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206 | 75818250 | ths | |
207 | 75818250 | ths | return 0; |
208 | 75818250 | ths | } |
209 | 75818250 | ths | |
210 | 75818250 | ths | static int nbd_write(BlockDriverState *bs, int64_t sector_num, |
211 | 75818250 | ths | const uint8_t *buf, int nb_sectors) |
212 | 75818250 | ths | { |
213 | 75818250 | ths | BDRVNBDState *s = bs->opaque; |
214 | 75818250 | ths | struct nbd_request request;
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215 | 75818250 | ths | struct nbd_reply reply;
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216 | 75818250 | ths | |
217 | 75818250 | ths | request.type = NBD_CMD_WRITE; |
218 | 75818250 | ths | request.handle = (uint64_t)(intptr_t)bs; |
219 | 75818250 | ths | request.from = sector_num * 512;;
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220 | 75818250 | ths | request.len = nb_sectors * 512;
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221 | 75818250 | ths | |
222 | 75818250 | ths | if (nbd_send_request(s->sock, &request) == -1) |
223 | 75818250 | ths | return -errno;
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224 | 75818250 | ths | |
225 | 75818250 | ths | if (nbd_wr_sync(s->sock, (uint8_t*)buf, request.len, 0) != request.len) |
226 | 75818250 | ths | return -EIO;
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227 | 75818250 | ths | |
228 | 75818250 | ths | if (nbd_receive_reply(s->sock, &reply) == -1) |
229 | 75818250 | ths | return -errno;
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230 | 75818250 | ths | |
231 | 75818250 | ths | if (reply.error !=0) |
232 | 75818250 | ths | return -reply.error;
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233 | 75818250 | ths | |
234 | 75818250 | ths | if (reply.handle != request.handle)
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235 | 75818250 | ths | return -EIO;
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236 | 75818250 | ths | |
237 | 75818250 | ths | return 0; |
238 | 75818250 | ths | } |
239 | 75818250 | ths | |
240 | 75818250 | ths | static void nbd_close(BlockDriverState *bs) |
241 | 75818250 | ths | { |
242 | d2d979c6 | Nick Thomas | BDRVNBDState *s = bs->opaque; |
243 | d2d979c6 | Nick Thomas | qemu_free(s->export_name); |
244 | d2d979c6 | Nick Thomas | qemu_free(s->host_spec); |
245 | d2d979c6 | Nick Thomas | |
246 | 33897dc7 | Nick Thomas | nbd_teardown_connection(bs); |
247 | 75818250 | ths | } |
248 | 75818250 | ths | |
249 | 75818250 | ths | static int64_t nbd_getlength(BlockDriverState *bs)
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250 | 75818250 | ths | { |
251 | 75818250 | ths | BDRVNBDState *s = bs->opaque; |
252 | 75818250 | ths | |
253 | 75818250 | ths | return s->size;
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254 | 75818250 | ths | } |
255 | 75818250 | ths | |
256 | 5efa9d5a | Anthony Liguori | static BlockDriver bdrv_nbd = {
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257 | e60f469c | aurel32 | .format_name = "nbd",
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258 | e60f469c | aurel32 | .instance_size = sizeof(BDRVNBDState),
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259 | 66f82cee | Kevin Wolf | .bdrv_file_open = nbd_open, |
260 | e60f469c | aurel32 | .bdrv_read = nbd_read, |
261 | e60f469c | aurel32 | .bdrv_write = nbd_write, |
262 | e60f469c | aurel32 | .bdrv_close = nbd_close, |
263 | e60f469c | aurel32 | .bdrv_getlength = nbd_getlength, |
264 | e60f469c | aurel32 | .protocol_name = "nbd",
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265 | 75818250 | ths | }; |
266 | 5efa9d5a | Anthony Liguori | |
267 | 5efa9d5a | Anthony Liguori | static void bdrv_nbd_init(void) |
268 | 5efa9d5a | Anthony Liguori | { |
269 | 5efa9d5a | Anthony Liguori | bdrv_register(&bdrv_nbd); |
270 | 5efa9d5a | Anthony Liguori | } |
271 | 5efa9d5a | Anthony Liguori | |
272 | 5efa9d5a | Anthony Liguori | block_init(bdrv_nbd_init); |