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