Peter Lieven | 6542aa9 | 2014-02-03 10:26:13 +0100 | [diff] [blame] | 1 | /* |
| 2 | * QEMU Block driver for native access to files on NFS shares |
| 3 | * |
| 4 | * Copyright (c) 2014 Peter Lieven <pl@kamp.de> |
| 5 | * |
| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 7 | * of this software and associated documentation files (the "Software"), to deal |
| 8 | * in the Software without restriction, including without limitation the rights |
| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 10 | * copies of the Software, and to permit persons to whom the Software is |
| 11 | * furnished to do so, subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be included in |
| 14 | * all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 22 | * THE SOFTWARE. |
| 23 | */ |
| 24 | |
| 25 | #include "config-host.h" |
| 26 | |
| 27 | #include <poll.h> |
| 28 | #include "qemu-common.h" |
| 29 | #include "qemu/config-file.h" |
| 30 | #include "qemu/error-report.h" |
| 31 | #include "block/block_int.h" |
| 32 | #include "trace.h" |
| 33 | #include "qemu/iov.h" |
| 34 | #include "qemu/uri.h" |
| 35 | #include "sysemu/sysemu.h" |
| 36 | #include <nfsc/libnfs.h> |
| 37 | |
| 38 | typedef struct NFSClient { |
| 39 | struct nfs_context *context; |
| 40 | struct nfsfh *fh; |
| 41 | int events; |
| 42 | bool has_zero_init; |
| 43 | } NFSClient; |
| 44 | |
| 45 | typedef struct NFSRPC { |
| 46 | int ret; |
| 47 | int complete; |
| 48 | QEMUIOVector *iov; |
| 49 | struct stat *st; |
| 50 | Coroutine *co; |
| 51 | QEMUBH *bh; |
| 52 | } NFSRPC; |
| 53 | |
| 54 | static void nfs_process_read(void *arg); |
| 55 | static void nfs_process_write(void *arg); |
| 56 | |
| 57 | static void nfs_set_events(NFSClient *client) |
| 58 | { |
| 59 | int ev = nfs_which_events(client->context); |
| 60 | if (ev != client->events) { |
| 61 | qemu_aio_set_fd_handler(nfs_get_fd(client->context), |
| 62 | (ev & POLLIN) ? nfs_process_read : NULL, |
| 63 | (ev & POLLOUT) ? nfs_process_write : NULL, |
| 64 | client); |
| 65 | |
| 66 | } |
| 67 | client->events = ev; |
| 68 | } |
| 69 | |
| 70 | static void nfs_process_read(void *arg) |
| 71 | { |
| 72 | NFSClient *client = arg; |
| 73 | nfs_service(client->context, POLLIN); |
| 74 | nfs_set_events(client); |
| 75 | } |
| 76 | |
| 77 | static void nfs_process_write(void *arg) |
| 78 | { |
| 79 | NFSClient *client = arg; |
| 80 | nfs_service(client->context, POLLOUT); |
| 81 | nfs_set_events(client); |
| 82 | } |
| 83 | |
| 84 | static void nfs_co_init_task(NFSClient *client, NFSRPC *task) |
| 85 | { |
| 86 | *task = (NFSRPC) { |
| 87 | .co = qemu_coroutine_self(), |
| 88 | }; |
| 89 | } |
| 90 | |
| 91 | static void nfs_co_generic_bh_cb(void *opaque) |
| 92 | { |
| 93 | NFSRPC *task = opaque; |
| 94 | qemu_bh_delete(task->bh); |
| 95 | qemu_coroutine_enter(task->co, NULL); |
| 96 | } |
| 97 | |
| 98 | static void |
| 99 | nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data, |
| 100 | void *private_data) |
| 101 | { |
| 102 | NFSRPC *task = private_data; |
| 103 | task->complete = 1; |
| 104 | task->ret = ret; |
| 105 | if (task->ret > 0 && task->iov) { |
| 106 | if (task->ret <= task->iov->size) { |
| 107 | qemu_iovec_from_buf(task->iov, 0, data, task->ret); |
| 108 | } else { |
| 109 | task->ret = -EIO; |
| 110 | } |
| 111 | } |
| 112 | if (task->ret == 0 && task->st) { |
| 113 | memcpy(task->st, data, sizeof(struct stat)); |
| 114 | } |
Peter Lieven | 20fccb1 | 2014-03-17 09:37:21 +0100 | [diff] [blame] | 115 | if (task->ret < 0) { |
| 116 | error_report("NFS Error: %s", nfs_get_error(nfs)); |
| 117 | } |
Peter Lieven | 6542aa9 | 2014-02-03 10:26:13 +0100 | [diff] [blame] | 118 | if (task->co) { |
| 119 | task->bh = qemu_bh_new(nfs_co_generic_bh_cb, task); |
| 120 | qemu_bh_schedule(task->bh); |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | static int coroutine_fn nfs_co_readv(BlockDriverState *bs, |
| 125 | int64_t sector_num, int nb_sectors, |
| 126 | QEMUIOVector *iov) |
| 127 | { |
| 128 | NFSClient *client = bs->opaque; |
| 129 | NFSRPC task; |
| 130 | |
| 131 | nfs_co_init_task(client, &task); |
| 132 | task.iov = iov; |
| 133 | |
| 134 | if (nfs_pread_async(client->context, client->fh, |
| 135 | sector_num * BDRV_SECTOR_SIZE, |
| 136 | nb_sectors * BDRV_SECTOR_SIZE, |
| 137 | nfs_co_generic_cb, &task) != 0) { |
| 138 | return -ENOMEM; |
| 139 | } |
| 140 | |
| 141 | while (!task.complete) { |
| 142 | nfs_set_events(client); |
| 143 | qemu_coroutine_yield(); |
| 144 | } |
| 145 | |
| 146 | if (task.ret < 0) { |
| 147 | return task.ret; |
| 148 | } |
| 149 | |
| 150 | /* zero pad short reads */ |
| 151 | if (task.ret < iov->size) { |
| 152 | qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret); |
| 153 | } |
| 154 | |
| 155 | return 0; |
| 156 | } |
| 157 | |
| 158 | static int coroutine_fn nfs_co_writev(BlockDriverState *bs, |
| 159 | int64_t sector_num, int nb_sectors, |
| 160 | QEMUIOVector *iov) |
| 161 | { |
| 162 | NFSClient *client = bs->opaque; |
| 163 | NFSRPC task; |
| 164 | char *buf = NULL; |
| 165 | |
| 166 | nfs_co_init_task(client, &task); |
| 167 | |
| 168 | buf = g_malloc(nb_sectors * BDRV_SECTOR_SIZE); |
| 169 | qemu_iovec_to_buf(iov, 0, buf, nb_sectors * BDRV_SECTOR_SIZE); |
| 170 | |
| 171 | if (nfs_pwrite_async(client->context, client->fh, |
| 172 | sector_num * BDRV_SECTOR_SIZE, |
| 173 | nb_sectors * BDRV_SECTOR_SIZE, |
| 174 | buf, nfs_co_generic_cb, &task) != 0) { |
| 175 | g_free(buf); |
| 176 | return -ENOMEM; |
| 177 | } |
| 178 | |
| 179 | while (!task.complete) { |
| 180 | nfs_set_events(client); |
| 181 | qemu_coroutine_yield(); |
| 182 | } |
| 183 | |
| 184 | g_free(buf); |
| 185 | |
| 186 | if (task.ret != nb_sectors * BDRV_SECTOR_SIZE) { |
| 187 | return task.ret < 0 ? task.ret : -EIO; |
| 188 | } |
| 189 | |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | static int coroutine_fn nfs_co_flush(BlockDriverState *bs) |
| 194 | { |
| 195 | NFSClient *client = bs->opaque; |
| 196 | NFSRPC task; |
| 197 | |
| 198 | nfs_co_init_task(client, &task); |
| 199 | |
| 200 | if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb, |
| 201 | &task) != 0) { |
| 202 | return -ENOMEM; |
| 203 | } |
| 204 | |
| 205 | while (!task.complete) { |
| 206 | nfs_set_events(client); |
| 207 | qemu_coroutine_yield(); |
| 208 | } |
| 209 | |
| 210 | return task.ret; |
| 211 | } |
| 212 | |
| 213 | /* TODO Convert to fine grained options */ |
| 214 | static QemuOptsList runtime_opts = { |
| 215 | .name = "nfs", |
| 216 | .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), |
| 217 | .desc = { |
| 218 | { |
| 219 | .name = "filename", |
| 220 | .type = QEMU_OPT_STRING, |
| 221 | .help = "URL to the NFS file", |
| 222 | }, |
| 223 | { /* end of list */ } |
| 224 | }, |
| 225 | }; |
| 226 | |
| 227 | static void nfs_client_close(NFSClient *client) |
| 228 | { |
| 229 | if (client->context) { |
| 230 | if (client->fh) { |
| 231 | nfs_close(client->context, client->fh); |
| 232 | } |
| 233 | qemu_aio_set_fd_handler(nfs_get_fd(client->context), NULL, NULL, NULL); |
| 234 | nfs_destroy_context(client->context); |
| 235 | } |
| 236 | memset(client, 0, sizeof(NFSClient)); |
| 237 | } |
| 238 | |
| 239 | static void nfs_file_close(BlockDriverState *bs) |
| 240 | { |
| 241 | NFSClient *client = bs->opaque; |
| 242 | nfs_client_close(client); |
| 243 | } |
| 244 | |
| 245 | static int64_t nfs_client_open(NFSClient *client, const char *filename, |
| 246 | int flags, Error **errp) |
| 247 | { |
| 248 | int ret = -EINVAL, i; |
| 249 | struct stat st; |
| 250 | URI *uri; |
| 251 | QueryParams *qp = NULL; |
| 252 | char *file = NULL, *strp = NULL; |
| 253 | |
| 254 | uri = uri_parse(filename); |
| 255 | if (!uri) { |
| 256 | error_setg(errp, "Invalid URL specified"); |
| 257 | goto fail; |
| 258 | } |
Max Reitz | 5f4d5e1 | 2014-05-05 20:27:49 +0200 | [diff] [blame] | 259 | if (!uri->server) { |
| 260 | error_setg(errp, "Invalid URL specified"); |
| 261 | goto fail; |
| 262 | } |
Peter Lieven | 6542aa9 | 2014-02-03 10:26:13 +0100 | [diff] [blame] | 263 | strp = strrchr(uri->path, '/'); |
| 264 | if (strp == NULL) { |
| 265 | error_setg(errp, "Invalid URL specified"); |
| 266 | goto fail; |
| 267 | } |
| 268 | file = g_strdup(strp); |
| 269 | *strp = 0; |
| 270 | |
| 271 | client->context = nfs_init_context(); |
| 272 | if (client->context == NULL) { |
| 273 | error_setg(errp, "Failed to init NFS context"); |
| 274 | goto fail; |
| 275 | } |
| 276 | |
| 277 | qp = query_params_parse(uri->query); |
| 278 | for (i = 0; i < qp->n; i++) { |
| 279 | if (!qp->p[i].value) { |
| 280 | error_setg(errp, "Value for NFS parameter expected: %s", |
| 281 | qp->p[i].name); |
| 282 | goto fail; |
| 283 | } |
| 284 | if (!strncmp(qp->p[i].name, "uid", 3)) { |
| 285 | nfs_set_uid(client->context, atoi(qp->p[i].value)); |
| 286 | } else if (!strncmp(qp->p[i].name, "gid", 3)) { |
| 287 | nfs_set_gid(client->context, atoi(qp->p[i].value)); |
| 288 | } else if (!strncmp(qp->p[i].name, "tcp-syncnt", 10)) { |
| 289 | nfs_set_tcp_syncnt(client->context, atoi(qp->p[i].value)); |
| 290 | } else { |
| 291 | error_setg(errp, "Unknown NFS parameter name: %s", |
| 292 | qp->p[i].name); |
| 293 | goto fail; |
| 294 | } |
| 295 | } |
| 296 | |
| 297 | ret = nfs_mount(client->context, uri->server, uri->path); |
| 298 | if (ret < 0) { |
| 299 | error_setg(errp, "Failed to mount nfs share: %s", |
| 300 | nfs_get_error(client->context)); |
| 301 | goto fail; |
| 302 | } |
| 303 | |
| 304 | if (flags & O_CREAT) { |
| 305 | ret = nfs_creat(client->context, file, 0600, &client->fh); |
| 306 | if (ret < 0) { |
| 307 | error_setg(errp, "Failed to create file: %s", |
| 308 | nfs_get_error(client->context)); |
| 309 | goto fail; |
| 310 | } |
| 311 | } else { |
| 312 | ret = nfs_open(client->context, file, flags, &client->fh); |
| 313 | if (ret < 0) { |
| 314 | error_setg(errp, "Failed to open file : %s", |
| 315 | nfs_get_error(client->context)); |
| 316 | goto fail; |
| 317 | } |
| 318 | } |
| 319 | |
| 320 | ret = nfs_fstat(client->context, client->fh, &st); |
| 321 | if (ret < 0) { |
| 322 | error_setg(errp, "Failed to fstat file: %s", |
| 323 | nfs_get_error(client->context)); |
| 324 | goto fail; |
| 325 | } |
| 326 | |
| 327 | ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE); |
| 328 | client->has_zero_init = S_ISREG(st.st_mode); |
| 329 | goto out; |
| 330 | fail: |
| 331 | nfs_client_close(client); |
| 332 | out: |
| 333 | if (qp) { |
| 334 | query_params_free(qp); |
| 335 | } |
| 336 | uri_free(uri); |
| 337 | g_free(file); |
| 338 | return ret; |
| 339 | } |
| 340 | |
| 341 | static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags, |
| 342 | Error **errp) { |
| 343 | NFSClient *client = bs->opaque; |
| 344 | int64_t ret; |
| 345 | QemuOpts *opts; |
| 346 | Error *local_err = NULL; |
| 347 | |
| 348 | opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); |
| 349 | qemu_opts_absorb_qdict(opts, options, &local_err); |
Markus Armbruster | 0fb6395 | 2014-04-25 16:50:31 +0200 | [diff] [blame] | 350 | if (local_err) { |
Peter Lieven | 6542aa9 | 2014-02-03 10:26:13 +0100 | [diff] [blame] | 351 | error_propagate(errp, local_err); |
| 352 | return -EINVAL; |
| 353 | } |
| 354 | ret = nfs_client_open(client, qemu_opt_get(opts, "filename"), |
| 355 | (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY, |
| 356 | errp); |
| 357 | if (ret < 0) { |
| 358 | return ret; |
| 359 | } |
| 360 | bs->total_sectors = ret; |
| 361 | return 0; |
| 362 | } |
| 363 | |
| 364 | static int nfs_file_create(const char *url, QEMUOptionParameter *options, |
| 365 | Error **errp) |
| 366 | { |
| 367 | int ret = 0; |
| 368 | int64_t total_size = 0; |
| 369 | NFSClient *client = g_malloc0(sizeof(NFSClient)); |
| 370 | |
| 371 | /* Read out options */ |
| 372 | while (options && options->name) { |
| 373 | if (!strcmp(options->name, "size")) { |
| 374 | total_size = options->value.n; |
| 375 | } |
| 376 | options++; |
| 377 | } |
| 378 | |
| 379 | ret = nfs_client_open(client, url, O_CREAT, errp); |
| 380 | if (ret < 0) { |
| 381 | goto out; |
| 382 | } |
| 383 | ret = nfs_ftruncate(client->context, client->fh, total_size); |
| 384 | nfs_client_close(client); |
| 385 | out: |
| 386 | g_free(client); |
| 387 | return ret; |
| 388 | } |
| 389 | |
| 390 | static int nfs_has_zero_init(BlockDriverState *bs) |
| 391 | { |
| 392 | NFSClient *client = bs->opaque; |
| 393 | return client->has_zero_init; |
| 394 | } |
| 395 | |
| 396 | static int64_t nfs_get_allocated_file_size(BlockDriverState *bs) |
| 397 | { |
| 398 | NFSClient *client = bs->opaque; |
| 399 | NFSRPC task = {0}; |
| 400 | struct stat st; |
| 401 | |
| 402 | task.st = &st; |
| 403 | if (nfs_fstat_async(client->context, client->fh, nfs_co_generic_cb, |
| 404 | &task) != 0) { |
| 405 | return -ENOMEM; |
| 406 | } |
| 407 | |
| 408 | while (!task.complete) { |
| 409 | nfs_set_events(client); |
| 410 | qemu_aio_wait(); |
| 411 | } |
| 412 | |
| 413 | return (task.ret < 0 ? task.ret : st.st_blocks * st.st_blksize); |
| 414 | } |
| 415 | |
| 416 | static int nfs_file_truncate(BlockDriverState *bs, int64_t offset) |
| 417 | { |
| 418 | NFSClient *client = bs->opaque; |
| 419 | return nfs_ftruncate(client->context, client->fh, offset); |
| 420 | } |
| 421 | |
| 422 | static BlockDriver bdrv_nfs = { |
| 423 | .format_name = "nfs", |
| 424 | .protocol_name = "nfs", |
| 425 | |
| 426 | .instance_size = sizeof(NFSClient), |
| 427 | .bdrv_needs_filename = true, |
| 428 | .bdrv_has_zero_init = nfs_has_zero_init, |
| 429 | .bdrv_get_allocated_file_size = nfs_get_allocated_file_size, |
| 430 | .bdrv_truncate = nfs_file_truncate, |
| 431 | |
| 432 | .bdrv_file_open = nfs_file_open, |
| 433 | .bdrv_close = nfs_file_close, |
| 434 | .bdrv_create = nfs_file_create, |
| 435 | |
| 436 | .bdrv_co_readv = nfs_co_readv, |
| 437 | .bdrv_co_writev = nfs_co_writev, |
| 438 | .bdrv_co_flush_to_disk = nfs_co_flush, |
| 439 | }; |
| 440 | |
| 441 | static void nfs_block_init(void) |
| 442 | { |
| 443 | bdrv_register(&bdrv_nfs); |
| 444 | } |
| 445 | |
| 446 | block_init(nfs_block_init); |