block/nfs.c

   1 /*
   2  * QEMU Block driver for native access to files on NFS shares
   3  *
   4  * Copyright (c) 2014-2016 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-common.h"
  29 #include "qemu/config-file.h"
  30 #include "qemu/error-report.h"
  31 #include "qapi/error.h"
  32 #include "block/block_int.h"
  33 #include "trace.h"
  34 #include "qemu/iov.h"
  35 #include "qemu/uri.h"
  36 #include "qemu/cutils.h"
  37 #include "sysemu/sysemu.h"
  38 #include "qapi/qmp/qdict.h"
  39 #include "qapi/qmp/qint.h"
  40 #include "qapi/qmp/qstring.h"
  41 #include "qapi-visit.h"
  42 #include "qapi/qobject-input-visitor.h"
  43 #include "qapi/qobject-output-visitor.h"
  44 #include <nfsc/libnfs.h>
  45
  46
  47 #define QEMU_NFS_MAX_READAHEAD_SIZE 1048576
  48 #define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE)
  49 #define QEMU_NFS_MAX_DEBUG_LEVEL 2
  50
  51 typedef struct NFSClient {
  52     struct nfs_context *context;
  53     struct nfsfh *fh;
  54     int events;
  55     bool has_zero_init;
  56     AioContext *aio_context;
  57     blkcnt_t st_blocks;
  58     bool cache_used;
  59     NFSServer *server;
  60     char *path;
  61     int64_t uid, gid, tcp_syncnt, readahead, pagecache, debug;
  62 } NFSClient;
  63
  64 typedef struct NFSRPC {
  65     BlockDriverState *bs;
  66     int ret;
  67     int complete;
  68     QEMUIOVector *iov;
  69     struct stat *st;
  70     Coroutine *co;
  71     NFSClient *client;
  72 } NFSRPC;
  73
  74 static int nfs_parse_uri(const char *filename, QDict *options, Error **errp)
  75 {
  76     URI *uri = NULL;
  77     QueryParams *qp = NULL;
  78     int ret = -EINVAL, i;
  79
  80     uri = uri_parse(filename);
  81     if (!uri) {
  82         error_setg(errp, "Invalid URI specified");
  83         goto out;
  84     }
  85     if (strcmp(uri->scheme, "nfs") != 0) {
  86         error_setg(errp, "URI scheme must be 'nfs'");
  87         goto out;
  88     }
  89
  90     if (!uri->server) {
  91         error_setg(errp, "missing hostname in URI");
  92         goto out;
  93     }
  94
  95     if (!uri->path) {
  96         error_setg(errp, "missing file path in URI");
  97         goto out;
  98     }
  99
 100     qp = query_params_parse(uri->query);
 101     if (!qp) {
 102         error_setg(errp, "could not parse query parameters");
 103         goto out;
 104     }
 105
 106     qdict_put(options, "server.host", qstring_from_str(uri->server));
 107     qdict_put(options, "server.type", qstring_from_str("inet"));
 108     qdict_put(options, "path", qstring_from_str(uri->path));
 109
 110     for (i = 0; i < qp->n; i++) {
 111         unsigned long long val;
 112         if (!qp->p[i].value) {
 113             error_setg(errp, "Value for NFS parameter expected: %s",
 114                        qp->p[i].name);
 115             goto out;
 116         }
 117         if (parse_uint_full(qp->p[i].value, &val, 0)) {
 118             error_setg(errp, "Illegal value for NFS parameter: %s",
 119                        qp->p[i].name);
 120             goto out;
 121         }
 122         if (!strcmp(qp->p[i].name, "uid")) {
 123             qdict_put(options, "user",
 124                       qstring_from_str(qp->p[i].value));
 125         } else if (!strcmp(qp->p[i].name, "gid")) {
 126             qdict_put(options, "group",
 127                       qstring_from_str(qp->p[i].value));
 128         } else if (!strcmp(qp->p[i].name, "tcp-syncnt")) {
 129             qdict_put(options, "tcp-syn-count",
 130                       qstring_from_str(qp->p[i].value));
 131         } else if (!strcmp(qp->p[i].name, "readahead")) {
 132             qdict_put(options, "readahead-size",
 133                       qstring_from_str(qp->p[i].value));
 134         } else if (!strcmp(qp->p[i].name, "pagecache")) {
 135             qdict_put(options, "page-cache-size",
 136                       qstring_from_str(qp->p[i].value));
 137         } else if (!strcmp(qp->p[i].name, "debug")) {
 138             qdict_put(options, "debug",
 139                       qstring_from_str(qp->p[i].value));
 140         } else {
 141             error_setg(errp, "Unknown NFS parameter name: %s",
 142                        qp->p[i].name);
 143             goto out;
 144         }
 145     }
 146     ret = 0;
 147 out:
 148     if (qp) {
 149         query_params_free(qp);
 150     }
 151     if (uri) {
 152         uri_free(uri);
 153     }
 154     return ret;
 155 }
 156
 157 static bool nfs_has_filename_options_conflict(QDict *options, Error **errp)
 158 {
 159     const QDictEntry *qe;
 160
 161     for (qe = qdict_first(options); qe; qe = qdict_next(options, qe)) {
 162         if (!strcmp(qe->key, "host") ||
 163             !strcmp(qe->key, "path") ||
 164             !strcmp(qe->key, "user") ||
 165             !strcmp(qe->key, "group") ||
 166             !strcmp(qe->key, "tcp-syn-count") ||
 167             !strcmp(qe->key, "readahead-size") ||
 168             !strcmp(qe->key, "page-cache-size") ||
 169             !strcmp(qe->key, "debug") ||
 170             strstart(qe->key, "server.", NULL))
 171         {
 172             error_setg(errp, "Option %s cannot be used with a filename",
 173                        qe->key);
 174             return true;
 175         }
 176     }
 177
 178     return false;
 179 }
 180
 181 static void nfs_parse_filename(const char *filename, QDict *options,
 182                                Error **errp)
 183 {
 184     if (nfs_has_filename_options_conflict(options, errp)) {
 185         return;
 186     }
 187
 188     nfs_parse_uri(filename, options, errp);
 189 }
 190
 191 static void nfs_process_read(void *arg);
 192 static void nfs_process_write(void *arg);
 193
 194 static void nfs_set_events(NFSClient *client)
 195 {
 196     int ev = nfs_which_events(client->context);
 197     if (ev != client->events) {
 198         aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 199                            false,
 200                            (ev & POLLIN) ? nfs_process_read : NULL,
 201                            (ev & POLLOUT) ? nfs_process_write : NULL,
 202                            NULL, client);
 203
 204     }
 205     client->events = ev;
 206 }
 207
 208 static void nfs_process_read(void *arg)
 209 {
 210     NFSClient *client = arg;
 211
 212     aio_context_acquire(client->aio_context);
 213     nfs_service(client->context, POLLIN);
 214     nfs_set_events(client);
 215     aio_context_release(client->aio_context);
 216 }
 217
 218 static void nfs_process_write(void *arg)
 219 {
 220     NFSClient *client = arg;
 221
 222     aio_context_acquire(client->aio_context);
 223     nfs_service(client->context, POLLOUT);
 224     nfs_set_events(client);
 225     aio_context_release(client->aio_context);
 226 }
 227
 228 static void nfs_co_init_task(BlockDriverState *bs, NFSRPC *task)
 229 {
 230     *task = (NFSRPC) {
 231         .co             = qemu_coroutine_self(),
 232         .bs             = bs,
 233         .client         = bs->opaque,
 234     };
 235 }
 236
 237 static void nfs_co_generic_bh_cb(void *opaque)
 238 {
 239     NFSRPC *task = opaque;
 240
 241     task->complete = 1;
 242     aio_co_wake(task->co);
 243 }
 244
 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     aio_bh_schedule_oneshot(task->client->aio_context,
 263                             nfs_co_generic_bh_cb, task);
 264 }
 265
 266 static int coroutine_fn nfs_co_readv(BlockDriverState *bs,
 267                                      int64_t sector_num, int nb_sectors,
 268                                      QEMUIOVector *iov)
 269 {
 270     NFSClient *client = bs->opaque;
 271     NFSRPC task;
 272
 273     nfs_co_init_task(bs, &task);
 274     task.iov = iov;
 275
 276     if (nfs_pread_async(client->context, client->fh,
 277                         sector_num * BDRV_SECTOR_SIZE,
 278                         nb_sectors * BDRV_SECTOR_SIZE,
 279                         nfs_co_generic_cb, &task) != 0) {
 280         return -ENOMEM;
 281     }
 282
 283     nfs_set_events(client);
 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_writev(BlockDriverState *bs,
 301                                         int64_t sector_num, int nb_sectors,
 302                                         QEMUIOVector *iov)
 303 {
 304     NFSClient *client = bs->opaque;
 305     NFSRPC task;
 306     char *buf = NULL;
 307
 308     nfs_co_init_task(bs, &task);
 309
 310     buf = g_try_malloc(nb_sectors * BDRV_SECTOR_SIZE);
 311     if (nb_sectors && buf == NULL) {
 312         return -ENOMEM;
 313     }
 314
 315     qemu_iovec_to_buf(iov, 0, buf, nb_sectors * BDRV_SECTOR_SIZE);
 316
 317     if (nfs_pwrite_async(client->context, client->fh,
 318                          sector_num * BDRV_SECTOR_SIZE,
 319                          nb_sectors * BDRV_SECTOR_SIZE,
 320                          buf, nfs_co_generic_cb, &task) != 0) {
 321         g_free(buf);
 322         return -ENOMEM;
 323     }
 324
 325     nfs_set_events(client);
 326     while (!task.complete) {
 327         qemu_coroutine_yield();
 328     }
 329
 330     g_free(buf);
 331
 332     if (task.ret != nb_sectors * BDRV_SECTOR_SIZE) {
 333         return task.ret < 0 ? task.ret : -EIO;
 334     }
 335
 336     return 0;
 337 }
 338
 339 static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
 340 {
 341     NFSClient *client = bs->opaque;
 342     NFSRPC task;
 343
 344     nfs_co_init_task(bs, &task);
 345
 346     if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
 347                         &task) != 0) {
 348         return -ENOMEM;
 349     }
 350
 351     nfs_set_events(client);
 352     while (!task.complete) {
 353         qemu_coroutine_yield();
 354     }
 355
 356     return task.ret;
 357 }
 358
 359 static QemuOptsList runtime_opts = {
 360     .name = "nfs",
 361     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 362     .desc = {
 363         {
 364             .name = "path",
 365             .type = QEMU_OPT_STRING,
 366             .help = "Path of the image on the host",
 367         },
 368         {
 369             .name = "user",
 370             .type = QEMU_OPT_NUMBER,
 371             .help = "UID value to use when talking to the server",
 372         },
 373         {
 374             .name = "group",
 375             .type = QEMU_OPT_NUMBER,
 376             .help = "GID value to use when talking to the server",
 377         },
 378         {
 379             .name = "tcp-syn-count",
 380             .type = QEMU_OPT_NUMBER,
 381             .help = "Number of SYNs to send during the session establish",
 382         },
 383         {
 384             .name = "readahead-size",
 385             .type = QEMU_OPT_NUMBER,
 386             .help = "Set the readahead size in bytes",
 387         },
 388         {
 389             .name = "page-cache-size",
 390             .type = QEMU_OPT_NUMBER,
 391             .help = "Set the pagecache size in bytes",
 392         },
 393         {
 394             .name = "debug",
 395             .type = QEMU_OPT_NUMBER,
 396             .help = "Set the NFS debug level (max 2)",
 397         },
 398         { /* end of list */ }
 399     },
 400 };
 401
 402 static void nfs_detach_aio_context(BlockDriverState *bs)
 403 {
 404     NFSClient *client = bs->opaque;
 405
 406     aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 407                        false, NULL, NULL, NULL, NULL);
 408     client->events = 0;
 409 }
 410
 411 static void nfs_attach_aio_context(BlockDriverState *bs,
 412                                    AioContext *new_context)
 413 {
 414     NFSClient *client = bs->opaque;
 415
 416     client->aio_context = new_context;
 417     nfs_set_events(client);
 418 }
 419
 420 static void nfs_client_close(NFSClient *client)
 421 {
 422     if (client->context) {
 423         if (client->fh) {
 424             nfs_close(client->context, client->fh);
 425         }
 426         aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 427                            false, NULL, NULL, NULL, NULL);
 428         nfs_destroy_context(client->context);
 429     }
 430     memset(client, 0, sizeof(NFSClient));
 431 }
 432
 433 static void nfs_file_close(BlockDriverState *bs)
 434 {
 435     NFSClient *client = bs->opaque;
 436     nfs_client_close(client);
 437 }
 438
 439 static NFSServer *nfs_config(QDict *options, Error **errp)
 440 {
 441     NFSServer *server = NULL;
 442     QDict *addr = NULL;
 443     QObject *crumpled_addr = NULL;
 444     Visitor *iv = NULL;
 445     Error *local_error = NULL;
 446
 447     qdict_extract_subqdict(options, &addr, "server.");
 448     if (!qdict_size(addr)) {
 449         error_setg(errp, "NFS server address missing");
 450         goto out;
 451     }
 452
 453     crumpled_addr = qdict_crumple(addr, errp);
 454     if (!crumpled_addr) {
 455         goto out;
 456     }
 457
 458     iv = qobject_input_visitor_new(crumpled_addr, true);
 459     visit_type_NFSServer(iv, NULL, &server, &local_error);
 460     if (local_error) {
 461         error_propagate(errp, local_error);
 462         goto out;
 463     }
 464
 465 out:
 466     QDECREF(addr);
 467     qobject_decref(crumpled_addr);
 468     visit_free(iv);
 469     return server;
 470 }
 471
 472
 473 static int64_t nfs_client_open(NFSClient *client, QDict *options,
 474                                int flags, Error **errp, int open_flags)
 475 {
 476     int ret = -EINVAL;
 477     QemuOpts *opts = NULL;
 478     Error *local_err = NULL;
 479     struct stat st;
 480     char *file = NULL, *strp = NULL;
 481
 482     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 483     qemu_opts_absorb_qdict(opts, options, &local_err);
 484     if (local_err) {
 485         error_propagate(errp, local_err);
 486         ret = -EINVAL;
 487         goto fail;
 488     }
 489
 490     client->path = g_strdup(qemu_opt_get(opts, "path"));
 491     if (!client->path) {
 492         ret = -EINVAL;
 493         error_setg(errp, "No path was specified");
 494         goto fail;
 495     }
 496
 497     strp = strrchr(client->path, '/');
 498     if (strp == NULL) {
 499         error_setg(errp, "Invalid URL specified");
 500         goto fail;
 501     }
 502     file = g_strdup(strp);
 503     *strp = 0;
 504
 505     /* Pop the config into our state object, Exit if invalid */
 506     client->server = nfs_config(options, errp);
 507     if (!client->server) {
 508         ret = -EINVAL;
 509         goto fail;
 510     }
 511
 512     client->context = nfs_init_context();
 513     if (client->context == NULL) {
 514         error_setg(errp, "Failed to init NFS context");
 515         goto fail;
 516     }
 517
 518     if (qemu_opt_get(opts, "user")) {
 519         client->uid = qemu_opt_get_number(opts, "user", 0);
 520         nfs_set_uid(client->context, client->uid);
 521     }
 522
 523     if (qemu_opt_get(opts, "group")) {
 524         client->gid = qemu_opt_get_number(opts, "group", 0);
 525         nfs_set_gid(client->context, client->gid);
 526     }
 527
 528     if (qemu_opt_get(opts, "tcp-syn-count")) {
 529         client->tcp_syncnt = qemu_opt_get_number(opts, "tcp-syn-count", 0);
 530         nfs_set_tcp_syncnt(client->context, client->tcp_syncnt);
 531     }
 532
 533 #ifdef LIBNFS_FEATURE_READAHEAD
 534     if (qemu_opt_get(opts, "readahead-size")) {
 535         if (open_flags & BDRV_O_NOCACHE) {
 536             error_setg(errp, "Cannot enable NFS readahead "
 537                              "if cache.direct = on");
 538             goto fail;
 539         }
 540         client->readahead = qemu_opt_get_number(opts, "readahead-size", 0);
 541         if (client->readahead > QEMU_NFS_MAX_READAHEAD_SIZE) {
 542             error_report("NFS Warning: Truncating NFS readahead "
 543                          "size to %d", QEMU_NFS_MAX_READAHEAD_SIZE);
 544             client->readahead = QEMU_NFS_MAX_READAHEAD_SIZE;
 545         }
 546         nfs_set_readahead(client->context, client->readahead);
 547 #ifdef LIBNFS_FEATURE_PAGECACHE
 548         nfs_set_pagecache_ttl(client->context, 0);
 549 #endif
 550         client->cache_used = true;
 551     }
 552 #endif
 553
 554 #ifdef LIBNFS_FEATURE_PAGECACHE
 555     if (qemu_opt_get(opts, "page-cache-size")) {
 556         if (open_flags & BDRV_O_NOCACHE) {
 557             error_setg(errp, "Cannot enable NFS pagecache "
 558                              "if cache.direct = on");
 559             goto fail;
 560         }
 561         client->pagecache = qemu_opt_get_number(opts, "page-cache-size", 0);
 562         if (client->pagecache > QEMU_NFS_MAX_PAGECACHE_SIZE) {
 563             error_report("NFS Warning: Truncating NFS pagecache "
 564                          "size to %d pages", QEMU_NFS_MAX_PAGECACHE_SIZE);
 565             client->pagecache = QEMU_NFS_MAX_PAGECACHE_SIZE;
 566         }
 567         nfs_set_pagecache(client->context, client->pagecache);
 568         nfs_set_pagecache_ttl(client->context, 0);
 569         client->cache_used = true;
 570     }
 571 #endif
 572
 573 #ifdef LIBNFS_FEATURE_DEBUG
 574     if (qemu_opt_get(opts, "debug")) {
 575         client->debug = qemu_opt_get_number(opts, "debug", 0);
 576         /* limit the maximum debug level to avoid potential flooding
 577          * of our log files. */
 578         if (client->debug > QEMU_NFS_MAX_DEBUG_LEVEL) {
 579             error_report("NFS Warning: Limiting NFS debug level "
 580                          "to %d", QEMU_NFS_MAX_DEBUG_LEVEL);
 581             client->debug = QEMU_NFS_MAX_DEBUG_LEVEL;
 582         }
 583         nfs_set_debug(client->context, client->debug);
 584     }
 585 #endif
 586
 587     ret = nfs_mount(client->context, client->server->host, client->path);
 588     if (ret < 0) {
 589         error_setg(errp, "Failed to mount nfs share: %s",
 590                    nfs_get_error(client->context));
 591         goto fail;
 592     }
 593
 594     if (flags & O_CREAT) {
 595         ret = nfs_creat(client->context, file, 0600, &client->fh);
 596         if (ret < 0) {
 597             error_setg(errp, "Failed to create file: %s",
 598                        nfs_get_error(client->context));
 599             goto fail;
 600         }
 601     } else {
 602         ret = nfs_open(client->context, file, flags, &client->fh);
 603         if (ret < 0) {
 604             error_setg(errp, "Failed to open file : %s",
 605                        nfs_get_error(client->context));
 606             goto fail;
 607         }
 608     }
 609
 610     ret = nfs_fstat(client->context, client->fh, &st);
 611     if (ret < 0) {
 612         error_setg(errp, "Failed to fstat file: %s",
 613                    nfs_get_error(client->context));
 614         goto fail;
 615     }
 616
 617     ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
 618     client->st_blocks = st.st_blocks;
 619     client->has_zero_init = S_ISREG(st.st_mode);
 620     *strp = '/';
 621     goto out;
 622
 623 fail:
 624     nfs_client_close(client);
 625 out:
 626     qemu_opts_del(opts);
 627     g_free(file);
 628     return ret;
 629 }
 630
 631 static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
 632                          Error **errp) {
 633     NFSClient *client = bs->opaque;
 634     int64_t ret;
 635
 636     client->aio_context = bdrv_get_aio_context(bs);
 637
 638     ret = nfs_client_open(client, options,
 639                           (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
 640                           errp, bs->open_flags);
 641     if (ret < 0) {
 642         return ret;
 643     }
 644     bs->total_sectors = ret;
 645     ret = 0;
 646     return ret;
 647 }
 648
 649 static QemuOptsList nfs_create_opts = {
 650     .name = "nfs-create-opts",
 651     .head = QTAILQ_HEAD_INITIALIZER(nfs_create_opts.head),
 652     .desc = {
 653         {
 654             .name = BLOCK_OPT_SIZE,
 655             .type = QEMU_OPT_SIZE,
 656             .help = "Virtual disk size"
 657         },
 658         { /* end of list */ }
 659     }
 660 };
 661
 662 static int nfs_file_create(const char *url, QemuOpts *opts, Error **errp)
 663 {
 664     int ret = 0;
 665     int64_t total_size = 0;
 666     NFSClient *client = g_new0(NFSClient, 1);
 667     QDict *options = NULL;
 668
 669     client->aio_context = qemu_get_aio_context();
 670
 671     /* Read out options */
 672     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 673                           BDRV_SECTOR_SIZE);
 674
 675     options = qdict_new();
 676     ret = nfs_parse_uri(url, options, errp);
 677     if (ret < 0) {
 678         goto out;
 679     }
 680
 681     ret = nfs_client_open(client, options, O_CREAT, errp, 0);
 682     if (ret < 0) {
 683         goto out;
 684     }
 685     ret = nfs_ftruncate(client->context, client->fh, total_size);
 686     nfs_client_close(client);
 687 out:
 688     QDECREF(options);
 689     g_free(client);
 690     return ret;
 691 }
 692
 693 static int nfs_has_zero_init(BlockDriverState *bs)
 694 {
 695     NFSClient *client = bs->opaque;
 696     return client->has_zero_init;
 697 }
 698
 699 static void
 700 nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
 701                                void *private_data)
 702 {
 703     NFSRPC *task = private_data;
 704     task->ret = ret;
 705     if (task->ret == 0) {
 706         memcpy(task->st, data, sizeof(struct stat));
 707     }
 708     if (task->ret < 0) {
 709         error_report("NFS Error: %s", nfs_get_error(nfs));
 710     }
 711     task->complete = 1;
 712     bdrv_wakeup(task->bs);
 713 }
 714
 715 static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
 716 {
 717     NFSClient *client = bs->opaque;
 718     NFSRPC task = {0};
 719     struct stat st;
 720
 721     if (bdrv_is_read_only(bs) &&
 722         !(bs->open_flags & BDRV_O_NOCACHE)) {
 723         return client->st_blocks * 512;
 724     }
 725
 726     task.bs = bs;
 727     task.st = &st;
 728     if (nfs_fstat_async(client->context, client->fh, nfs_get_allocated_file_size_cb,
 729                         &task) != 0) {
 730         return -ENOMEM;
 731     }
 732
 733     nfs_set_events(client);
 734     BDRV_POLL_WHILE(bs, !task.complete);
 735
 736     return (task.ret < 0 ? task.ret : st.st_blocks * 512);
 737 }
 738
 739 static int nfs_file_truncate(BlockDriverState *bs, int64_t offset)
 740 {
 741     NFSClient *client = bs->opaque;
 742     return nfs_ftruncate(client->context, client->fh, offset);
 743 }
 744
 745 /* Note that this will not re-establish a connection with the NFS server
 746  * - it is effectively a NOP.  */
 747 static int nfs_reopen_prepare(BDRVReopenState *state,
 748                               BlockReopenQueue *queue, Error **errp)
 749 {
 750     NFSClient *client = state->bs->opaque;
 751     struct stat st;
 752     int ret = 0;
 753
 754     if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) {
 755         error_setg(errp, "Cannot open a read-only mount as read-write");
 756         return -EACCES;
 757     }
 758
 759     if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) {
 760         error_setg(errp, "Cannot disable cache if libnfs readahead or"
 761                          " pagecache is enabled");
 762         return -EINVAL;
 763     }
 764
 765     /* Update cache for read-only reopens */
 766     if (!(state->flags & BDRV_O_RDWR)) {
 767         ret = nfs_fstat(client->context, client->fh, &st);
 768         if (ret < 0) {
 769             error_setg(errp, "Failed to fstat file: %s",
 770                        nfs_get_error(client->context));
 771             return ret;
 772         }
 773         client->st_blocks = st.st_blocks;
 774     }
 775
 776     return 0;
 777 }
 778
 779 static void nfs_refresh_filename(BlockDriverState *bs, QDict *options)
 780 {
 781     NFSClient *client = bs->opaque;
 782     QDict *opts = qdict_new();
 783     QObject *server_qdict;
 784     Visitor *ov;
 785
 786     qdict_put(opts, "driver", qstring_from_str("nfs"));
 787
 788     if (client->uid && !client->gid) {
 789         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 790                  "nfs://%s%s?uid=%" PRId64, client->server->host, client->path,
 791                  client->uid);
 792     } else if (!client->uid && client->gid) {
 793         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 794                  "nfs://%s%s?gid=%" PRId64, client->server->host, client->path,
 795                  client->gid);
 796     } else if (client->uid && client->gid) {
 797         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 798                  "nfs://%s%s?uid=%" PRId64 "&gid=%" PRId64,
 799                  client->server->host, client->path, client->uid, client->gid);
 800     } else {
 801         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 802                  "nfs://%s%s", client->server->host, client->path);
 803     }
 804
 805     ov = qobject_output_visitor_new(&server_qdict);
 806     visit_type_NFSServer(ov, NULL, &client->server, &error_abort);
 807     visit_complete(ov, &server_qdict);
 808     assert(qobject_type(server_qdict) == QTYPE_QDICT);
 809
 810     qdict_put_obj(opts, "server", server_qdict);
 811     qdict_put(opts, "path", qstring_from_str(client->path));
 812
 813     if (client->uid) {
 814         qdict_put(opts, "user", qint_from_int(client->uid));
 815     }
 816     if (client->gid) {
 817         qdict_put(opts, "group", qint_from_int(client->gid));
 818     }
 819     if (client->tcp_syncnt) {
 820         qdict_put(opts, "tcp-syn-cnt",
 821                   qint_from_int(client->tcp_syncnt));
 822     }
 823     if (client->readahead) {
 824         qdict_put(opts, "readahead-size",
 825                   qint_from_int(client->readahead));
 826     }
 827     if (client->pagecache) {
 828         qdict_put(opts, "page-cache-size",
 829                   qint_from_int(client->pagecache));
 830     }
 831     if (client->debug) {
 832         qdict_put(opts, "debug", qint_from_int(client->debug));
 833     }
 834
 835     visit_free(ov);
 836     qdict_flatten(opts);
 837     bs->full_open_options = opts;
 838 }
 839
 840 #ifdef LIBNFS_FEATURE_PAGECACHE
 841 static void nfs_invalidate_cache(BlockDriverState *bs,
 842                                  Error **errp)
 843 {
 844     NFSClient *client = bs->opaque;
 845     nfs_pagecache_invalidate(client->context, client->fh);
 846 }
 847 #endif
 848
 849 static BlockDriver bdrv_nfs = {
 850     .format_name                    = "nfs",
 851     .protocol_name                  = "nfs",
 852
 853     .instance_size                  = sizeof(NFSClient),
 854     .bdrv_parse_filename            = nfs_parse_filename,
 855     .create_opts                    = &nfs_create_opts,
 856
 857     .bdrv_has_zero_init             = nfs_has_zero_init,
 858     .bdrv_get_allocated_file_size   = nfs_get_allocated_file_size,
 859     .bdrv_truncate                  = nfs_file_truncate,
 860
 861     .bdrv_file_open                 = nfs_file_open,
 862     .bdrv_close                     = nfs_file_close,
 863     .bdrv_create                    = nfs_file_create,
 864     .bdrv_reopen_prepare            = nfs_reopen_prepare,
 865
 866     .bdrv_co_readv                  = nfs_co_readv,
 867     .bdrv_co_writev                 = nfs_co_writev,
 868     .bdrv_co_flush_to_disk          = nfs_co_flush,
 869
 870     .bdrv_detach_aio_context        = nfs_detach_aio_context,
 871     .bdrv_attach_aio_context        = nfs_attach_aio_context,
 872     .bdrv_refresh_filename          = nfs_refresh_filename,
 873
 874 #ifdef LIBNFS_FEATURE_PAGECACHE
 875     .bdrv_invalidate_cache          = nfs_invalidate_cache,
 876 #endif
 877 };
 878
 879 static void nfs_block_init(void)
 880 {
 881     bdrv_register(&bdrv_nfs);
 882 }
 883
 884 block_init(nfs_block_init);