1 /* 2 * QEMU Block driver for native access to files on NFS shares 3 * 4 * Copyright (c) 2014-2017 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 "qemu/osdep.h" 26 27 #include <poll.h> 28 #include "qemu/config-file.h" 29 #include "qemu/error-report.h" 30 #include "qapi/error.h" 31 #include "block/block_int.h" 32 #include "block/qdict.h" 33 #include "trace.h" 34 #include "qemu/iov.h" 35 #include "qemu/main-loop.h" 36 #include "qemu/module.h" 37 #include "qemu/option.h" 38 #include "qemu/uri.h" 39 #include "qemu/cutils.h" 40 #include "sysemu/sysemu.h" 41 #include "sysemu/replay.h" 42 #include "qapi/qapi-visit-block-core.h" 43 #include "qapi/qmp/qdict.h" 44 #include "qapi/qmp/qstring.h" 45 #include "qapi/qobject-input-visitor.h" 46 #include "qapi/qobject-output-visitor.h" 47 #include <nfsc/libnfs.h> 48 49 50 #define QEMU_NFS_MAX_READAHEAD_SIZE 1048576 51 #define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE) 52 #define QEMU_NFS_MAX_DEBUG_LEVEL 2 53 54 typedef struct NFSClient { 55 struct nfs_context *context; 56 struct nfsfh *fh; 57 int events; 58 bool has_zero_init; 59 AioContext *aio_context; 60 QemuMutex mutex; 61 blkcnt_t st_blocks; 62 bool cache_used; 63 NFSServer *server; 64 char *path; 65 int64_t uid, gid, tcp_syncnt, readahead, pagecache, debug; 66 } NFSClient; 67 68 typedef struct NFSRPC { 69 BlockDriverState *bs; 70 int ret; 71 int complete; 72 QEMUIOVector *iov; 73 struct stat *st; 74 Coroutine *co; 75 NFSClient *client; 76 } NFSRPC; 77 78 static int nfs_parse_uri(const char *filename, QDict *options, Error **errp) 79 { 80 URI *uri = NULL; 81 QueryParams *qp = NULL; 82 int ret = -EINVAL, i; 83 84 uri = uri_parse(filename); 85 if (!uri) { 86 error_setg(errp, "Invalid URI specified"); 87 goto out; 88 } 89 if (g_strcmp0(uri->scheme, "nfs") != 0) { 90 error_setg(errp, "URI scheme must be 'nfs'"); 91 goto out; 92 } 93 94 if (!uri->server) { 95 error_setg(errp, "missing hostname in URI"); 96 goto out; 97 } 98 99 if (!uri->path) { 100 error_setg(errp, "missing file path in URI"); 101 goto out; 102 } 103 104 qp = query_params_parse(uri->query); 105 if (!qp) { 106 error_setg(errp, "could not parse query parameters"); 107 goto out; 108 } 109 110 qdict_put_str(options, "server.host", uri->server); 111 qdict_put_str(options, "server.type", "inet"); 112 qdict_put_str(options, "path", uri->path); 113 114 for (i = 0; i < qp->n; i++) { 115 unsigned long long val; 116 if (!qp->p[i].value) { 117 error_setg(errp, "Value for NFS parameter expected: %s", 118 qp->p[i].name); 119 goto out; 120 } 121 if (parse_uint_full(qp->p[i].value, &val, 0)) { 122 error_setg(errp, "Illegal value for NFS parameter: %s", 123 qp->p[i].name); 124 goto out; 125 } 126 if (!strcmp(qp->p[i].name, "uid")) { 127 qdict_put_str(options, "user", qp->p[i].value); 128 } else if (!strcmp(qp->p[i].name, "gid")) { 129 qdict_put_str(options, "group", qp->p[i].value); 130 } else if (!strcmp(qp->p[i].name, "tcp-syncnt")) { 131 qdict_put_str(options, "tcp-syn-count", qp->p[i].value); 132 } else if (!strcmp(qp->p[i].name, "readahead")) { 133 qdict_put_str(options, "readahead-size", qp->p[i].value); 134 } else if (!strcmp(qp->p[i].name, "pagecache")) { 135 qdict_put_str(options, "page-cache-size", qp->p[i].value); 136 } else if (!strcmp(qp->p[i].name, "debug")) { 137 qdict_put_str(options, "debug", qp->p[i].value); 138 } else { 139 error_setg(errp, "Unknown NFS parameter name: %s", 140 qp->p[i].name); 141 goto out; 142 } 143 } 144 ret = 0; 145 out: 146 if (qp) { 147 query_params_free(qp); 148 } 149 if (uri) { 150 uri_free(uri); 151 } 152 return ret; 153 } 154 155 static bool nfs_has_filename_options_conflict(QDict *options, Error **errp) 156 { 157 const QDictEntry *qe; 158 159 for (qe = qdict_first(options); qe; qe = qdict_next(options, qe)) { 160 if (!strcmp(qe->key, "host") || 161 !strcmp(qe->key, "path") || 162 !strcmp(qe->key, "user") || 163 !strcmp(qe->key, "group") || 164 !strcmp(qe->key, "tcp-syn-count") || 165 !strcmp(qe->key, "readahead-size") || 166 !strcmp(qe->key, "page-cache-size") || 167 !strcmp(qe->key, "debug") || 168 strstart(qe->key, "server.", NULL)) 169 { 170 error_setg(errp, "Option %s cannot be used with a filename", 171 qe->key); 172 return true; 173 } 174 } 175 176 return false; 177 } 178 179 static void nfs_parse_filename(const char *filename, QDict *options, 180 Error **errp) 181 { 182 if (nfs_has_filename_options_conflict(options, errp)) { 183 return; 184 } 185 186 nfs_parse_uri(filename, options, errp); 187 } 188 189 static void nfs_process_read(void *arg); 190 static void nfs_process_write(void *arg); 191 192 /* Called with QemuMutex held. */ 193 static void nfs_set_events(NFSClient *client) 194 { 195 int ev = nfs_which_events(client->context); 196 if (ev != client->events) { 197 aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context), 198 false, 199 (ev & POLLIN) ? nfs_process_read : NULL, 200 (ev & POLLOUT) ? nfs_process_write : NULL, 201 NULL, client); 202 203 } 204 client->events = ev; 205 } 206 207 static void nfs_process_read(void *arg) 208 { 209 NFSClient *client = arg; 210 211 qemu_mutex_lock(&client->mutex); 212 nfs_service(client->context, POLLIN); 213 nfs_set_events(client); 214 qemu_mutex_unlock(&client->mutex); 215 } 216 217 static void nfs_process_write(void *arg) 218 { 219 NFSClient *client = arg; 220 221 qemu_mutex_lock(&client->mutex); 222 nfs_service(client->context, POLLOUT); 223 nfs_set_events(client); 224 qemu_mutex_unlock(&client->mutex); 225 } 226 227 static void nfs_co_init_task(BlockDriverState *bs, NFSRPC *task) 228 { 229 *task = (NFSRPC) { 230 .co = qemu_coroutine_self(), 231 .bs = bs, 232 .client = bs->opaque, 233 }; 234 } 235 236 static void nfs_co_generic_bh_cb(void *opaque) 237 { 238 NFSRPC *task = opaque; 239 240 task->complete = 1; 241 aio_co_wake(task->co); 242 } 243 244 /* Called (via nfs_service) with QemuMutex held. */ 245 static void 246 nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data, 247 void *private_data) 248 { 249 NFSRPC *task = private_data; 250 task->ret = ret; 251 assert(!task->st); 252 if (task->ret > 0 && task->iov) { 253 if (task->ret <= task->iov->size) { 254 qemu_iovec_from_buf(task->iov, 0, data, task->ret); 255 } else { 256 task->ret = -EIO; 257 } 258 } 259 if (task->ret < 0) { 260 error_report("NFS Error: %s", nfs_get_error(nfs)); 261 } 262 replay_bh_schedule_oneshot_event(task->client->aio_context, 263 nfs_co_generic_bh_cb, task); 264 } 265 266 static int coroutine_fn nfs_co_preadv(BlockDriverState *bs, uint64_t offset, 267 uint64_t bytes, QEMUIOVector *iov, 268 int flags) 269 { 270 NFSClient *client = bs->opaque; 271 NFSRPC task; 272 273 nfs_co_init_task(bs, &task); 274 task.iov = iov; 275 276 WITH_QEMU_LOCK_GUARD(&client->mutex) { 277 if (nfs_pread_async(client->context, client->fh, 278 offset, bytes, nfs_co_generic_cb, &task) != 0) { 279 return -ENOMEM; 280 } 281 282 nfs_set_events(client); 283 } 284 while (!task.complete) { 285 qemu_coroutine_yield(); 286 } 287 288 if (task.ret < 0) { 289 return task.ret; 290 } 291 292 /* zero pad short reads */ 293 if (task.ret < iov->size) { 294 qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret); 295 } 296 297 return 0; 298 } 299 300 static int coroutine_fn nfs_co_pwritev(BlockDriverState *bs, uint64_t offset, 301 uint64_t bytes, QEMUIOVector *iov, 302 int flags) 303 { 304 NFSClient *client = bs->opaque; 305 NFSRPC task; 306 char *buf = NULL; 307 bool my_buffer = false; 308 309 nfs_co_init_task(bs, &task); 310 311 if (iov->niov != 1) { 312 buf = g_try_malloc(bytes); 313 if (bytes && buf == NULL) { 314 return -ENOMEM; 315 } 316 qemu_iovec_to_buf(iov, 0, buf, bytes); 317 my_buffer = true; 318 } else { 319 buf = iov->iov[0].iov_base; 320 } 321 322 WITH_QEMU_LOCK_GUARD(&client->mutex) { 323 if (nfs_pwrite_async(client->context, client->fh, 324 offset, bytes, buf, 325 nfs_co_generic_cb, &task) != 0) { 326 if (my_buffer) { 327 g_free(buf); 328 } 329 return -ENOMEM; 330 } 331 332 nfs_set_events(client); 333 } 334 while (!task.complete) { 335 qemu_coroutine_yield(); 336 } 337 338 if (my_buffer) { 339 g_free(buf); 340 } 341 342 if (task.ret != bytes) { 343 return task.ret < 0 ? task.ret : -EIO; 344 } 345 346 return 0; 347 } 348 349 static int coroutine_fn nfs_co_flush(BlockDriverState *bs) 350 { 351 NFSClient *client = bs->opaque; 352 NFSRPC task; 353 354 nfs_co_init_task(bs, &task); 355 356 WITH_QEMU_LOCK_GUARD(&client->mutex) { 357 if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb, 358 &task) != 0) { 359 return -ENOMEM; 360 } 361 362 nfs_set_events(client); 363 } 364 while (!task.complete) { 365 qemu_coroutine_yield(); 366 } 367 368 return task.ret; 369 } 370 371 static void nfs_detach_aio_context(BlockDriverState *bs) 372 { 373 NFSClient *client = bs->opaque; 374 375 aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context), 376 false, NULL, NULL, NULL, NULL); 377 client->events = 0; 378 } 379 380 static void nfs_attach_aio_context(BlockDriverState *bs, 381 AioContext *new_context) 382 { 383 NFSClient *client = bs->opaque; 384 385 client->aio_context = new_context; 386 nfs_set_events(client); 387 } 388 389 static void nfs_client_close(NFSClient *client) 390 { 391 if (client->context) { 392 qemu_mutex_lock(&client->mutex); 393 aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context), 394 false, NULL, NULL, NULL, NULL); 395 qemu_mutex_unlock(&client->mutex); 396 if (client->fh) { 397 nfs_close(client->context, client->fh); 398 client->fh = NULL; 399 } 400 #ifdef LIBNFS_FEATURE_UMOUNT 401 nfs_umount(client->context); 402 #endif 403 nfs_destroy_context(client->context); 404 client->context = NULL; 405 } 406 g_free(client->path); 407 qemu_mutex_destroy(&client->mutex); 408 qapi_free_NFSServer(client->server); 409 client->server = NULL; 410 } 411 412 static void nfs_file_close(BlockDriverState *bs) 413 { 414 NFSClient *client = bs->opaque; 415 nfs_client_close(client); 416 } 417 418 static int64_t nfs_client_open(NFSClient *client, BlockdevOptionsNfs *opts, 419 int flags, int open_flags, Error **errp) 420 { 421 int64_t ret = -EINVAL; 422 struct stat st; 423 char *file = NULL, *strp = NULL; 424 425 qemu_mutex_init(&client->mutex); 426 427 client->path = g_strdup(opts->path); 428 429 strp = strrchr(client->path, '/'); 430 if (strp == NULL) { 431 error_setg(errp, "Invalid URL specified"); 432 goto fail; 433 } 434 file = g_strdup(strp); 435 *strp = 0; 436 437 /* Steal the NFSServer object from opts; set the original pointer to NULL 438 * to avoid use after free and double free. */ 439 client->server = opts->server; 440 opts->server = NULL; 441 442 client->context = nfs_init_context(); 443 if (client->context == NULL) { 444 error_setg(errp, "Failed to init NFS context"); 445 goto fail; 446 } 447 448 if (opts->has_user) { 449 client->uid = opts->user; 450 nfs_set_uid(client->context, client->uid); 451 } 452 453 if (opts->has_group) { 454 client->gid = opts->group; 455 nfs_set_gid(client->context, client->gid); 456 } 457 458 if (opts->has_tcp_syn_count) { 459 client->tcp_syncnt = opts->tcp_syn_count; 460 nfs_set_tcp_syncnt(client->context, client->tcp_syncnt); 461 } 462 463 #ifdef LIBNFS_FEATURE_READAHEAD 464 if (opts->has_readahead_size) { 465 if (open_flags & BDRV_O_NOCACHE) { 466 error_setg(errp, "Cannot enable NFS readahead " 467 "if cache.direct = on"); 468 goto fail; 469 } 470 client->readahead = opts->readahead_size; 471 if (client->readahead > QEMU_NFS_MAX_READAHEAD_SIZE) { 472 warn_report("Truncating NFS readahead size to %d", 473 QEMU_NFS_MAX_READAHEAD_SIZE); 474 client->readahead = QEMU_NFS_MAX_READAHEAD_SIZE; 475 } 476 nfs_set_readahead(client->context, client->readahead); 477 #ifdef LIBNFS_FEATURE_PAGECACHE 478 nfs_set_pagecache_ttl(client->context, 0); 479 #endif 480 client->cache_used = true; 481 } 482 #endif 483 484 #ifdef LIBNFS_FEATURE_PAGECACHE 485 if (opts->has_page_cache_size) { 486 if (open_flags & BDRV_O_NOCACHE) { 487 error_setg(errp, "Cannot enable NFS pagecache " 488 "if cache.direct = on"); 489 goto fail; 490 } 491 client->pagecache = opts->page_cache_size; 492 if (client->pagecache > QEMU_NFS_MAX_PAGECACHE_SIZE) { 493 warn_report("Truncating NFS pagecache size to %d pages", 494 QEMU_NFS_MAX_PAGECACHE_SIZE); 495 client->pagecache = QEMU_NFS_MAX_PAGECACHE_SIZE; 496 } 497 nfs_set_pagecache(client->context, client->pagecache); 498 nfs_set_pagecache_ttl(client->context, 0); 499 client->cache_used = true; 500 } 501 #endif 502 503 #ifdef LIBNFS_FEATURE_DEBUG 504 if (opts->has_debug) { 505 client->debug = opts->debug; 506 /* limit the maximum debug level to avoid potential flooding 507 * of our log files. */ 508 if (client->debug > QEMU_NFS_MAX_DEBUG_LEVEL) { 509 warn_report("Limiting NFS debug level to %d", 510 QEMU_NFS_MAX_DEBUG_LEVEL); 511 client->debug = QEMU_NFS_MAX_DEBUG_LEVEL; 512 } 513 nfs_set_debug(client->context, client->debug); 514 } 515 #endif 516 517 ret = nfs_mount(client->context, client->server->host, client->path); 518 if (ret < 0) { 519 error_setg(errp, "Failed to mount nfs share: %s", 520 nfs_get_error(client->context)); 521 goto fail; 522 } 523 524 if (flags & O_CREAT) { 525 ret = nfs_creat(client->context, file, 0600, &client->fh); 526 if (ret < 0) { 527 error_setg(errp, "Failed to create file: %s", 528 nfs_get_error(client->context)); 529 goto fail; 530 } 531 } else { 532 ret = nfs_open(client->context, file, flags, &client->fh); 533 if (ret < 0) { 534 error_setg(errp, "Failed to open file : %s", 535 nfs_get_error(client->context)); 536 goto fail; 537 } 538 } 539 540 ret = nfs_fstat(client->context, client->fh, &st); 541 if (ret < 0) { 542 error_setg(errp, "Failed to fstat file: %s", 543 nfs_get_error(client->context)); 544 goto fail; 545 } 546 547 ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE); 548 client->st_blocks = st.st_blocks; 549 client->has_zero_init = S_ISREG(st.st_mode); 550 *strp = '/'; 551 goto out; 552 553 fail: 554 nfs_client_close(client); 555 out: 556 g_free(file); 557 return ret; 558 } 559 560 static BlockdevOptionsNfs *nfs_options_qdict_to_qapi(QDict *options, 561 Error **errp) 562 { 563 BlockdevOptionsNfs *opts = NULL; 564 Visitor *v; 565 const QDictEntry *e; 566 Error *local_err = NULL; 567 568 v = qobject_input_visitor_new_flat_confused(options, errp); 569 if (!v) { 570 return NULL; 571 } 572 573 visit_type_BlockdevOptionsNfs(v, NULL, &opts, &local_err); 574 visit_free(v); 575 576 if (local_err) { 577 error_propagate(errp, local_err); 578 return NULL; 579 } 580 581 /* Remove the processed options from the QDict (the visitor processes 582 * _all_ options in the QDict) */ 583 while ((e = qdict_first(options))) { 584 qdict_del(options, e->key); 585 } 586 587 return opts; 588 } 589 590 static int64_t nfs_client_open_qdict(NFSClient *client, QDict *options, 591 int flags, int open_flags, Error **errp) 592 { 593 BlockdevOptionsNfs *opts; 594 int ret; 595 596 opts = nfs_options_qdict_to_qapi(options, errp); 597 if (opts == NULL) { 598 ret = -EINVAL; 599 goto fail; 600 } 601 602 ret = nfs_client_open(client, opts, flags, open_flags, errp); 603 fail: 604 qapi_free_BlockdevOptionsNfs(opts); 605 return ret; 606 } 607 608 static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags, 609 Error **errp) { 610 NFSClient *client = bs->opaque; 611 int64_t ret; 612 613 client->aio_context = bdrv_get_aio_context(bs); 614 615 ret = nfs_client_open_qdict(client, options, 616 (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY, 617 bs->open_flags, errp); 618 if (ret < 0) { 619 return ret; 620 } 621 622 bs->total_sectors = ret; 623 if (client->has_zero_init) { 624 bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE; 625 } 626 return 0; 627 } 628 629 static QemuOptsList nfs_create_opts = { 630 .name = "nfs-create-opts", 631 .head = QTAILQ_HEAD_INITIALIZER(nfs_create_opts.head), 632 .desc = { 633 { 634 .name = BLOCK_OPT_SIZE, 635 .type = QEMU_OPT_SIZE, 636 .help = "Virtual disk size" 637 }, 638 { /* end of list */ } 639 } 640 }; 641 642 static int nfs_file_co_create(BlockdevCreateOptions *options, Error **errp) 643 { 644 BlockdevCreateOptionsNfs *opts = &options->u.nfs; 645 NFSClient *client = g_new0(NFSClient, 1); 646 int ret; 647 648 assert(options->driver == BLOCKDEV_DRIVER_NFS); 649 650 client->aio_context = qemu_get_aio_context(); 651 652 ret = nfs_client_open(client, opts->location, O_CREAT, 0, errp); 653 if (ret < 0) { 654 goto out; 655 } 656 ret = nfs_ftruncate(client->context, client->fh, opts->size); 657 nfs_client_close(client); 658 659 out: 660 g_free(client); 661 return ret; 662 } 663 664 static int coroutine_fn nfs_file_co_create_opts(BlockDriver *drv, 665 const char *url, 666 QemuOpts *opts, 667 Error **errp) 668 { 669 BlockdevCreateOptions *create_options; 670 BlockdevCreateOptionsNfs *nfs_opts; 671 QDict *options; 672 int ret; 673 674 create_options = g_new0(BlockdevCreateOptions, 1); 675 create_options->driver = BLOCKDEV_DRIVER_NFS; 676 nfs_opts = &create_options->u.nfs; 677 678 /* Read out options */ 679 nfs_opts->size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), 680 BDRV_SECTOR_SIZE); 681 682 options = qdict_new(); 683 ret = nfs_parse_uri(url, options, errp); 684 if (ret < 0) { 685 goto out; 686 } 687 688 nfs_opts->location = nfs_options_qdict_to_qapi(options, errp); 689 if (nfs_opts->location == NULL) { 690 ret = -EINVAL; 691 goto out; 692 } 693 694 ret = nfs_file_co_create(create_options, errp); 695 if (ret < 0) { 696 goto out; 697 } 698 699 ret = 0; 700 out: 701 qobject_unref(options); 702 qapi_free_BlockdevCreateOptions(create_options); 703 return ret; 704 } 705 706 static int nfs_has_zero_init(BlockDriverState *bs) 707 { 708 NFSClient *client = bs->opaque; 709 return client->has_zero_init; 710 } 711 712 /* Called (via nfs_service) with QemuMutex held. */ 713 static void 714 nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data, 715 void *private_data) 716 { 717 NFSRPC *task = private_data; 718 task->ret = ret; 719 if (task->ret == 0) { 720 memcpy(task->st, data, sizeof(struct stat)); 721 } 722 if (task->ret < 0) { 723 error_report("NFS Error: %s", nfs_get_error(nfs)); 724 } 725 726 /* Set task->complete before reading bs->wakeup. */ 727 atomic_mb_set(&task->complete, 1); 728 bdrv_wakeup(task->bs); 729 } 730 731 static int64_t nfs_get_allocated_file_size(BlockDriverState *bs) 732 { 733 NFSClient *client = bs->opaque; 734 NFSRPC task = {0}; 735 struct stat st; 736 737 if (bdrv_is_read_only(bs) && 738 !(bs->open_flags & BDRV_O_NOCACHE)) { 739 return client->st_blocks * 512; 740 } 741 742 task.bs = bs; 743 task.st = &st; 744 if (nfs_fstat_async(client->context, client->fh, nfs_get_allocated_file_size_cb, 745 &task) != 0) { 746 return -ENOMEM; 747 } 748 749 nfs_set_events(client); 750 BDRV_POLL_WHILE(bs, !task.complete); 751 752 return (task.ret < 0 ? task.ret : st.st_blocks * 512); 753 } 754 755 static int coroutine_fn 756 nfs_file_co_truncate(BlockDriverState *bs, int64_t offset, bool exact, 757 PreallocMode prealloc, BdrvRequestFlags flags, 758 Error **errp) 759 { 760 NFSClient *client = bs->opaque; 761 int ret; 762 763 if (prealloc != PREALLOC_MODE_OFF) { 764 error_setg(errp, "Unsupported preallocation mode '%s'", 765 PreallocMode_str(prealloc)); 766 return -ENOTSUP; 767 } 768 769 ret = nfs_ftruncate(client->context, client->fh, offset); 770 if (ret < 0) { 771 error_setg_errno(errp, -ret, "Failed to truncate file"); 772 return ret; 773 } 774 775 return 0; 776 } 777 778 /* Note that this will not re-establish a connection with the NFS server 779 * - it is effectively a NOP. */ 780 static int nfs_reopen_prepare(BDRVReopenState *state, 781 BlockReopenQueue *queue, Error **errp) 782 { 783 NFSClient *client = state->bs->opaque; 784 struct stat st; 785 int ret = 0; 786 787 if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) { 788 error_setg(errp, "Cannot open a read-only mount as read-write"); 789 return -EACCES; 790 } 791 792 if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) { 793 error_setg(errp, "Cannot disable cache if libnfs readahead or" 794 " pagecache is enabled"); 795 return -EINVAL; 796 } 797 798 /* Update cache for read-only reopens */ 799 if (!(state->flags & BDRV_O_RDWR)) { 800 ret = nfs_fstat(client->context, client->fh, &st); 801 if (ret < 0) { 802 error_setg(errp, "Failed to fstat file: %s", 803 nfs_get_error(client->context)); 804 return ret; 805 } 806 client->st_blocks = st.st_blocks; 807 } 808 809 return 0; 810 } 811 812 static void nfs_refresh_filename(BlockDriverState *bs) 813 { 814 NFSClient *client = bs->opaque; 815 816 if (client->uid && !client->gid) { 817 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 818 "nfs://%s%s?uid=%" PRId64, client->server->host, client->path, 819 client->uid); 820 } else if (!client->uid && client->gid) { 821 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 822 "nfs://%s%s?gid=%" PRId64, client->server->host, client->path, 823 client->gid); 824 } else if (client->uid && client->gid) { 825 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 826 "nfs://%s%s?uid=%" PRId64 "&gid=%" PRId64, 827 client->server->host, client->path, client->uid, client->gid); 828 } else { 829 snprintf(bs->exact_filename, sizeof(bs->exact_filename), 830 "nfs://%s%s", client->server->host, client->path); 831 } 832 } 833 834 static char *nfs_dirname(BlockDriverState *bs, Error **errp) 835 { 836 NFSClient *client = bs->opaque; 837 838 if (client->uid || client->gid) { 839 bdrv_refresh_filename(bs); 840 error_setg(errp, "Cannot generate a base directory for NFS node '%s'", 841 bs->filename); 842 return NULL; 843 } 844 845 return g_strdup_printf("nfs://%s%s/", client->server->host, client->path); 846 } 847 848 #ifdef LIBNFS_FEATURE_PAGECACHE 849 static void coroutine_fn nfs_co_invalidate_cache(BlockDriverState *bs, 850 Error **errp) 851 { 852 NFSClient *client = bs->opaque; 853 nfs_pagecache_invalidate(client->context, client->fh); 854 } 855 #endif 856 857 static const char *nfs_strong_runtime_opts[] = { 858 "path", 859 "user", 860 "group", 861 "server.", 862 863 NULL 864 }; 865 866 static BlockDriver bdrv_nfs = { 867 .format_name = "nfs", 868 .protocol_name = "nfs", 869 870 .instance_size = sizeof(NFSClient), 871 .bdrv_parse_filename = nfs_parse_filename, 872 .create_opts = &nfs_create_opts, 873 874 .bdrv_has_zero_init = nfs_has_zero_init, 875 .bdrv_get_allocated_file_size = nfs_get_allocated_file_size, 876 .bdrv_co_truncate = nfs_file_co_truncate, 877 878 .bdrv_file_open = nfs_file_open, 879 .bdrv_close = nfs_file_close, 880 .bdrv_co_create = nfs_file_co_create, 881 .bdrv_co_create_opts = nfs_file_co_create_opts, 882 .bdrv_reopen_prepare = nfs_reopen_prepare, 883 884 .bdrv_co_preadv = nfs_co_preadv, 885 .bdrv_co_pwritev = nfs_co_pwritev, 886 .bdrv_co_flush_to_disk = nfs_co_flush, 887 888 .bdrv_detach_aio_context = nfs_detach_aio_context, 889 .bdrv_attach_aio_context = nfs_attach_aio_context, 890 .bdrv_refresh_filename = nfs_refresh_filename, 891 .bdrv_dirname = nfs_dirname, 892 893 .strong_runtime_opts = nfs_strong_runtime_opts, 894 895 #ifdef LIBNFS_FEATURE_PAGECACHE 896 .bdrv_co_invalidate_cache = nfs_co_invalidate_cache, 897 #endif 898 }; 899 900 static void nfs_block_init(void) 901 { 902 bdrv_register(&bdrv_nfs); 903 } 904 905 block_init(nfs_block_init); 906