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     nfs_service(client->context, POLLIN);
 212     nfs_set_events(client);
 213 }
 214
 215 static void nfs_process_write(void *arg)
 216 {
 217     NFSClient *client = arg;
 218     nfs_service(client->context, POLLOUT);
 219     nfs_set_events(client);
 220 }
 221
 222 static void nfs_co_init_task(BlockDriverState *bs, NFSRPC *task)
 223 {
 224     *task = (NFSRPC) {
 225         .co             = qemu_coroutine_self(),
 226         .bs             = bs,
 227         .client         = bs->opaque,
 228     };
 229 }
 230
 231 static void nfs_co_generic_bh_cb(void *opaque)
 232 {
 233     NFSRPC *task = opaque;
 234     task->complete = 1;
 235     qemu_coroutine_enter(task->co);
 236 }
 237
 238 static void
 239 nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
 240                   void *private_data)
 241 {
 242     NFSRPC *task = private_data;
 243     task->ret = ret;
 244     assert(!task->st);
 245     if (task->ret > 0 && task->iov) {
 246         if (task->ret <= task->iov->size) {
 247             qemu_iovec_from_buf(task->iov, 0, data, task->ret);
 248         } else {
 249             task->ret = -EIO;
 250         }
 251     }
 252     if (task->ret < 0) {
 253         error_report("NFS Error: %s", nfs_get_error(nfs));
 254     }
 255     aio_bh_schedule_oneshot(task->client->aio_context,
 256                             nfs_co_generic_bh_cb, task);
 257 }
 258
 259 static int coroutine_fn nfs_co_readv(BlockDriverState *bs,
 260                                      int64_t sector_num, int nb_sectors,
 261                                      QEMUIOVector *iov)
 262 {
 263     NFSClient *client = bs->opaque;
 264     NFSRPC task;
 265
 266     nfs_co_init_task(bs, &task);
 267     task.iov = iov;
 268
 269     if (nfs_pread_async(client->context, client->fh,
 270                         sector_num * BDRV_SECTOR_SIZE,
 271                         nb_sectors * BDRV_SECTOR_SIZE,
 272                         nfs_co_generic_cb, &task) != 0) {
 273         return -ENOMEM;
 274     }
 275
 276     nfs_set_events(client);
 277     while (!task.complete) {
 278         qemu_coroutine_yield();
 279     }
 280
 281     if (task.ret < 0) {
 282         return task.ret;
 283     }
 284
 285     /* zero pad short reads */
 286     if (task.ret < iov->size) {
 287         qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret);
 288     }
 289
 290     return 0;
 291 }
 292
 293 static int coroutine_fn nfs_co_writev(BlockDriverState *bs,
 294                                         int64_t sector_num, int nb_sectors,
 295                                         QEMUIOVector *iov)
 296 {
 297     NFSClient *client = bs->opaque;
 298     NFSRPC task;
 299     char *buf = NULL;
 300
 301     nfs_co_init_task(bs, &task);
 302
 303     buf = g_try_malloc(nb_sectors * BDRV_SECTOR_SIZE);
 304     if (nb_sectors && buf == NULL) {
 305         return -ENOMEM;
 306     }
 307
 308     qemu_iovec_to_buf(iov, 0, buf, nb_sectors * BDRV_SECTOR_SIZE);
 309
 310     if (nfs_pwrite_async(client->context, client->fh,
 311                          sector_num * BDRV_SECTOR_SIZE,
 312                          nb_sectors * BDRV_SECTOR_SIZE,
 313                          buf, nfs_co_generic_cb, &task) != 0) {
 314         g_free(buf);
 315         return -ENOMEM;
 316     }
 317
 318     nfs_set_events(client);
 319     while (!task.complete) {
 320         qemu_coroutine_yield();
 321     }
 322
 323     g_free(buf);
 324
 325     if (task.ret != nb_sectors * BDRV_SECTOR_SIZE) {
 326         return task.ret < 0 ? task.ret : -EIO;
 327     }
 328
 329     return 0;
 330 }
 331
 332 static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
 333 {
 334     NFSClient *client = bs->opaque;
 335     NFSRPC task;
 336
 337     nfs_co_init_task(bs, &task);
 338
 339     if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
 340                         &task) != 0) {
 341         return -ENOMEM;
 342     }
 343
 344     nfs_set_events(client);
 345     while (!task.complete) {
 346         qemu_coroutine_yield();
 347     }
 348
 349     return task.ret;
 350 }
 351
 352 static QemuOptsList runtime_opts = {
 353     .name = "nfs",
 354     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 355     .desc = {
 356         {
 357             .name = "path",
 358             .type = QEMU_OPT_STRING,
 359             .help = "Path of the image on the host",
 360         },
 361         {
 362             .name = "user",
 363             .type = QEMU_OPT_NUMBER,
 364             .help = "UID value to use when talking to the server",
 365         },
 366         {
 367             .name = "group",
 368             .type = QEMU_OPT_NUMBER,
 369             .help = "GID value to use when talking to the server",
 370         },
 371         {
 372             .name = "tcp-syn-count",
 373             .type = QEMU_OPT_NUMBER,
 374             .help = "Number of SYNs to send during the session establish",
 375         },
 376         {
 377             .name = "readahead-size",
 378             .type = QEMU_OPT_NUMBER,
 379             .help = "Set the readahead size in bytes",
 380         },
 381         {
 382             .name = "page-cache-size",
 383             .type = QEMU_OPT_NUMBER,
 384             .help = "Set the pagecache size in bytes",
 385         },
 386         {
 387             .name = "debug",
 388             .type = QEMU_OPT_NUMBER,
 389             .help = "Set the NFS debug level (max 2)",
 390         },
 391         { /* end of list */ }
 392     },
 393 };
 394
 395 static void nfs_detach_aio_context(BlockDriverState *bs)
 396 {
 397     NFSClient *client = bs->opaque;
 398
 399     aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 400                        false, NULL, NULL, NULL, NULL);
 401     client->events = 0;
 402 }
 403
 404 static void nfs_attach_aio_context(BlockDriverState *bs,
 405                                    AioContext *new_context)
 406 {
 407     NFSClient *client = bs->opaque;
 408
 409     client->aio_context = new_context;
 410     nfs_set_events(client);
 411 }
 412
 413 static void nfs_client_close(NFSClient *client)
 414 {
 415     if (client->context) {
 416         if (client->fh) {
 417             nfs_close(client->context, client->fh);
 418         }
 419         aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 420                            false, NULL, NULL, NULL, NULL);
 421         nfs_destroy_context(client->context);
 422     }
 423     memset(client, 0, sizeof(NFSClient));
 424 }
 425
 426 static void nfs_file_close(BlockDriverState *bs)
 427 {
 428     NFSClient *client = bs->opaque;
 429     nfs_client_close(client);
 430 }
 431
 432 static NFSServer *nfs_config(QDict *options, Error **errp)
 433 {
 434     NFSServer *server = NULL;
 435     QDict *addr = NULL;
 436     QObject *crumpled_addr = NULL;
 437     Visitor *iv = NULL;
 438     Error *local_error = NULL;
 439
 440     qdict_extract_subqdict(options, &addr, "server.");
 441     if (!qdict_size(addr)) {
 442         error_setg(errp, "NFS server address missing");
 443         goto out;
 444     }
 445
 446     crumpled_addr = qdict_crumple(addr, errp);
 447     if (!crumpled_addr) {
 448         goto out;
 449     }
 450
 451     iv = qobject_input_visitor_new(crumpled_addr, true);
 452     visit_type_NFSServer(iv, NULL, &server, &local_error);
 453     if (local_error) {
 454         error_propagate(errp, local_error);
 455         goto out;
 456     }
 457
 458 out:
 459     QDECREF(addr);
 460     qobject_decref(crumpled_addr);
 461     visit_free(iv);
 462     return server;
 463 }
 464
 465
 466 static int64_t nfs_client_open(NFSClient *client, QDict *options,
 467                                int flags, Error **errp, int open_flags)
 468 {
 469     int ret = -EINVAL;
 470     QemuOpts *opts = NULL;
 471     Error *local_err = NULL;
 472     struct stat st;
 473     char *file = NULL, *strp = NULL;
 474
 475     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 476     qemu_opts_absorb_qdict(opts, options, &local_err);
 477     if (local_err) {
 478         error_propagate(errp, local_err);
 479         ret = -EINVAL;
 480         goto fail;
 481     }
 482
 483     client->path = g_strdup(qemu_opt_get(opts, "path"));
 484     if (!client->path) {
 485         ret = -EINVAL;
 486         error_setg(errp, "No path was specified");
 487         goto fail;
 488     }
 489
 490     strp = strrchr(client->path, '/');
 491     if (strp == NULL) {
 492         error_setg(errp, "Invalid URL specified");
 493         goto fail;
 494     }
 495     file = g_strdup(strp);
 496     *strp = 0;
 497
 498     /* Pop the config into our state object, Exit if invalid */
 499     client->server = nfs_config(options, errp);
 500     if (!client->server) {
 501         ret = -EINVAL;
 502         goto fail;
 503     }
 504
 505     client->context = nfs_init_context();
 506     if (client->context == NULL) {
 507         error_setg(errp, "Failed to init NFS context");
 508         goto fail;
 509     }
 510
 511     if (qemu_opt_get(opts, "user")) {
 512         client->uid = qemu_opt_get_number(opts, "user", 0);
 513         nfs_set_uid(client->context, client->uid);
 514     }
 515
 516     if (qemu_opt_get(opts, "group")) {
 517         client->gid = qemu_opt_get_number(opts, "group", 0);
 518         nfs_set_gid(client->context, client->gid);
 519     }
 520
 521     if (qemu_opt_get(opts, "tcp-syn-count")) {
 522         client->tcp_syncnt = qemu_opt_get_number(opts, "tcp-syn-count", 0);
 523         nfs_set_tcp_syncnt(client->context, client->tcp_syncnt);
 524     }
 525
 526 #ifdef LIBNFS_FEATURE_READAHEAD
 527     if (qemu_opt_get(opts, "readahead-size")) {
 528         if (open_flags & BDRV_O_NOCACHE) {
 529             error_setg(errp, "Cannot enable NFS readahead "
 530                              "if cache.direct = on");
 531             goto fail;
 532         }
 533         client->readahead = qemu_opt_get_number(opts, "readahead-size", 0);
 534         if (client->readahead > QEMU_NFS_MAX_READAHEAD_SIZE) {
 535             error_report("NFS Warning: Truncating NFS readahead "
 536                          "size to %d", QEMU_NFS_MAX_READAHEAD_SIZE);
 537             client->readahead = QEMU_NFS_MAX_READAHEAD_SIZE;
 538         }
 539         nfs_set_readahead(client->context, client->readahead);
 540 #ifdef LIBNFS_FEATURE_PAGECACHE
 541         nfs_set_pagecache_ttl(client->context, 0);
 542 #endif
 543         client->cache_used = true;
 544     }
 545 #endif
 546
 547 #ifdef LIBNFS_FEATURE_PAGECACHE
 548     if (qemu_opt_get(opts, "page-cache-size")) {
 549         if (open_flags & BDRV_O_NOCACHE) {
 550             error_setg(errp, "Cannot enable NFS pagecache "
 551                              "if cache.direct = on");
 552             goto fail;
 553         }
 554         client->pagecache = qemu_opt_get_number(opts, "page-cache-size", 0);
 555         if (client->pagecache > QEMU_NFS_MAX_PAGECACHE_SIZE) {
 556             error_report("NFS Warning: Truncating NFS pagecache "
 557                          "size to %d pages", QEMU_NFS_MAX_PAGECACHE_SIZE);
 558             client->pagecache = QEMU_NFS_MAX_PAGECACHE_SIZE;
 559         }
 560         nfs_set_pagecache(client->context, client->pagecache);
 561         nfs_set_pagecache_ttl(client->context, 0);
 562         client->cache_used = true;
 563     }
 564 #endif
 565
 566 #ifdef LIBNFS_FEATURE_DEBUG
 567     if (qemu_opt_get(opts, "debug")) {
 568         client->debug = qemu_opt_get_number(opts, "debug", 0);
 569         /* limit the maximum debug level to avoid potential flooding
 570          * of our log files. */
 571         if (client->debug > QEMU_NFS_MAX_DEBUG_LEVEL) {
 572             error_report("NFS Warning: Limiting NFS debug level "
 573                          "to %d", QEMU_NFS_MAX_DEBUG_LEVEL);
 574             client->debug = QEMU_NFS_MAX_DEBUG_LEVEL;
 575         }
 576         nfs_set_debug(client->context, client->debug);
 577     }
 578 #endif
 579
 580     ret = nfs_mount(client->context, client->server->host, client->path);
 581     if (ret < 0) {
 582         error_setg(errp, "Failed to mount nfs share: %s",
 583                    nfs_get_error(client->context));
 584         goto fail;
 585     }
 586
 587     if (flags & O_CREAT) {
 588         ret = nfs_creat(client->context, file, 0600, &client->fh);
 589         if (ret < 0) {
 590             error_setg(errp, "Failed to create file: %s",
 591                        nfs_get_error(client->context));
 592             goto fail;
 593         }
 594     } else {
 595         ret = nfs_open(client->context, file, flags, &client->fh);
 596         if (ret < 0) {
 597             error_setg(errp, "Failed to open file : %s",
 598                        nfs_get_error(client->context));
 599             goto fail;
 600         }
 601     }
 602
 603     ret = nfs_fstat(client->context, client->fh, &st);
 604     if (ret < 0) {
 605         error_setg(errp, "Failed to fstat file: %s",
 606                    nfs_get_error(client->context));
 607         goto fail;
 608     }
 609
 610     ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
 611     client->st_blocks = st.st_blocks;
 612     client->has_zero_init = S_ISREG(st.st_mode);
 613     *strp = '/';
 614     goto out;
 615
 616 fail:
 617     nfs_client_close(client);
 618 out:
 619     qemu_opts_del(opts);
 620     g_free(file);
 621     return ret;
 622 }
 623
 624 static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
 625                          Error **errp) {
 626     NFSClient *client = bs->opaque;
 627     int64_t ret;
 628
 629     client->aio_context = bdrv_get_aio_context(bs);
 630
 631     ret = nfs_client_open(client, options,
 632                           (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
 633                           errp, bs->open_flags);
 634     if (ret < 0) {
 635         return ret;
 636     }
 637     bs->total_sectors = ret;
 638     ret = 0;
 639     return ret;
 640 }
 641
 642 static QemuOptsList nfs_create_opts = {
 643     .name = "nfs-create-opts",
 644     .head = QTAILQ_HEAD_INITIALIZER(nfs_create_opts.head),
 645     .desc = {
 646         {
 647             .name = BLOCK_OPT_SIZE,
 648             .type = QEMU_OPT_SIZE,
 649             .help = "Virtual disk size"
 650         },
 651         { /* end of list */ }
 652     }
 653 };
 654
 655 static int nfs_file_create(const char *url, QemuOpts *opts, Error **errp)
 656 {
 657     int ret = 0;
 658     int64_t total_size = 0;
 659     NFSClient *client = g_new0(NFSClient, 1);
 660     QDict *options = NULL;
 661
 662     client->aio_context = qemu_get_aio_context();
 663
 664     /* Read out options */
 665     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 666                           BDRV_SECTOR_SIZE);
 667
 668     options = qdict_new();
 669     ret = nfs_parse_uri(url, options, errp);
 670     if (ret < 0) {
 671         goto out;
 672     }
 673
 674     ret = nfs_client_open(client, options, O_CREAT, errp, 0);
 675     if (ret < 0) {
 676         goto out;
 677     }
 678     ret = nfs_ftruncate(client->context, client->fh, total_size);
 679     nfs_client_close(client);
 680 out:
 681     QDECREF(options);
 682     g_free(client);
 683     return ret;
 684 }
 685
 686 static int nfs_has_zero_init(BlockDriverState *bs)
 687 {
 688     NFSClient *client = bs->opaque;
 689     return client->has_zero_init;
 690 }
 691
 692 static void
 693 nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
 694                                void *private_data)
 695 {
 696     NFSRPC *task = private_data;
 697     task->ret = ret;
 698     if (task->ret == 0) {
 699         memcpy(task->st, data, sizeof(struct stat));
 700     }
 701     if (task->ret < 0) {
 702         error_report("NFS Error: %s", nfs_get_error(nfs));
 703     }
 704     task->complete = 1;
 705     bdrv_wakeup(task->bs);
 706 }
 707
 708 static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
 709 {
 710     NFSClient *client = bs->opaque;
 711     NFSRPC task = {0};
 712     struct stat st;
 713
 714     if (bdrv_is_read_only(bs) &&
 715         !(bs->open_flags & BDRV_O_NOCACHE)) {
 716         return client->st_blocks * 512;
 717     }
 718
 719     task.bs = bs;
 720     task.st = &st;
 721     if (nfs_fstat_async(client->context, client->fh, nfs_get_allocated_file_size_cb,
 722                         &task) != 0) {
 723         return -ENOMEM;
 724     }
 725
 726     nfs_set_events(client);
 727     BDRV_POLL_WHILE(bs, !task.complete);
 728
 729     return (task.ret < 0 ? task.ret : st.st_blocks * 512);
 730 }
 731
 732 static int nfs_file_truncate(BlockDriverState *bs, int64_t offset)
 733 {
 734     NFSClient *client = bs->opaque;
 735     return nfs_ftruncate(client->context, client->fh, offset);
 736 }
 737
 738 /* Note that this will not re-establish a connection with the NFS server
 739  * - it is effectively a NOP.  */
 740 static int nfs_reopen_prepare(BDRVReopenState *state,
 741                               BlockReopenQueue *queue, Error **errp)
 742 {
 743     NFSClient *client = state->bs->opaque;
 744     struct stat st;
 745     int ret = 0;
 746
 747     if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) {
 748         error_setg(errp, "Cannot open a read-only mount as read-write");
 749         return -EACCES;
 750     }
 751
 752     if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) {
 753         error_setg(errp, "Cannot disable cache if libnfs readahead or"
 754                          " pagecache is enabled");
 755         return -EINVAL;
 756     }
 757
 758     /* Update cache for read-only reopens */
 759     if (!(state->flags & BDRV_O_RDWR)) {
 760         ret = nfs_fstat(client->context, client->fh, &st);
 761         if (ret < 0) {
 762             error_setg(errp, "Failed to fstat file: %s",
 763                        nfs_get_error(client->context));
 764             return ret;
 765         }
 766         client->st_blocks = st.st_blocks;
 767     }
 768
 769     return 0;
 770 }
 771
 772 static void nfs_refresh_filename(BlockDriverState *bs, QDict *options)
 773 {
 774     NFSClient *client = bs->opaque;
 775     QDict *opts = qdict_new();
 776     QObject *server_qdict;
 777     Visitor *ov;
 778
 779     qdict_put(opts, "driver", qstring_from_str("nfs"));
 780
 781     if (client->uid && !client->gid) {
 782         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 783                  "nfs://%s%s?uid=%" PRId64, client->server->host, client->path,
 784                  client->uid);
 785     } else if (!client->uid && client->gid) {
 786         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 787                  "nfs://%s%s?gid=%" PRId64, client->server->host, client->path,
 788                  client->gid);
 789     } else if (client->uid && client->gid) {
 790         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 791                  "nfs://%s%s?uid=%" PRId64 "&gid=%" PRId64,
 792                  client->server->host, client->path, client->uid, client->gid);
 793     } else {
 794         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 795                  "nfs://%s%s", client->server->host, client->path);
 796     }
 797
 798     ov = qobject_output_visitor_new(&server_qdict);
 799     visit_type_NFSServer(ov, NULL, &client->server, &error_abort);
 800     visit_complete(ov, &server_qdict);
 801     assert(qobject_type(server_qdict) == QTYPE_QDICT);
 802
 803     qdict_put_obj(opts, "server", server_qdict);
 804     qdict_put(opts, "path", qstring_from_str(client->path));
 805
 806     if (client->uid) {
 807         qdict_put(opts, "user", qint_from_int(client->uid));
 808     }
 809     if (client->gid) {
 810         qdict_put(opts, "group", qint_from_int(client->gid));
 811     }
 812     if (client->tcp_syncnt) {
 813         qdict_put(opts, "tcp-syn-cnt",
 814                   qint_from_int(client->tcp_syncnt));
 815     }
 816     if (client->readahead) {
 817         qdict_put(opts, "readahead-size",
 818                   qint_from_int(client->readahead));
 819     }
 820     if (client->pagecache) {
 821         qdict_put(opts, "page-cache-size",
 822                   qint_from_int(client->pagecache));
 823     }
 824     if (client->debug) {
 825         qdict_put(opts, "debug", qint_from_int(client->debug));
 826     }
 827
 828     visit_free(ov);
 829     qdict_flatten(opts);
 830     bs->full_open_options = opts;
 831 }
 832
 833 #ifdef LIBNFS_FEATURE_PAGECACHE
 834 static void nfs_invalidate_cache(BlockDriverState *bs,
 835                                  Error **errp)
 836 {
 837     NFSClient *client = bs->opaque;
 838     nfs_pagecache_invalidate(client->context, client->fh);
 839 }
 840 #endif
 841
 842 static BlockDriver bdrv_nfs = {
 843     .format_name                    = "nfs",
 844     .protocol_name                  = "nfs",
 845
 846     .instance_size                  = sizeof(NFSClient),
 847     .bdrv_parse_filename            = nfs_parse_filename,
 848     .create_opts                    = &nfs_create_opts,
 849
 850     .bdrv_has_zero_init             = nfs_has_zero_init,
 851     .bdrv_get_allocated_file_size   = nfs_get_allocated_file_size,
 852     .bdrv_truncate                  = nfs_file_truncate,
 853
 854     .bdrv_file_open                 = nfs_file_open,
 855     .bdrv_close                     = nfs_file_close,
 856     .bdrv_create                    = nfs_file_create,
 857     .bdrv_reopen_prepare            = nfs_reopen_prepare,
 858
 859     .bdrv_co_readv                  = nfs_co_readv,
 860     .bdrv_co_writev                 = nfs_co_writev,
 861     .bdrv_co_flush_to_disk          = nfs_co_flush,
 862
 863     .bdrv_detach_aio_context        = nfs_detach_aio_context,
 864     .bdrv_attach_aio_context        = nfs_attach_aio_context,
 865     .bdrv_refresh_filename          = nfs_refresh_filename,
 866
 867 #ifdef LIBNFS_FEATURE_PAGECACHE
 868     .bdrv_invalidate_cache          = nfs_invalidate_cache,
 869 #endif
 870 };
 871
 872 static void nfs_block_init(void)
 873 {
 874     bdrv_register(&bdrv_nfs);
 875 }
 876
 877 block_init(nfs_block_init);