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         if (!qp->p[i].value) {
 112             error_setg(errp, "Value for NFS parameter expected: %s",
 113                        qp->p[i].name);
 114             goto out;
 115         }
 116         if (parse_uint_full(qp->p[i].value, NULL, 0)) {
 117             error_setg(errp, "Illegal value for NFS parameter: %s",
 118                        qp->p[i].name);
 119             goto out;
 120         }
 121         if (!strcmp(qp->p[i].name, "uid")) {
 122             qdict_put(options, "user",
 123                       qstring_from_str(qp->p[i].value));
 124         } else if (!strcmp(qp->p[i].name, "gid")) {
 125             qdict_put(options, "group",
 126                       qstring_from_str(qp->p[i].value));
 127         } else if (!strcmp(qp->p[i].name, "tcp-syncnt")) {
 128             qdict_put(options, "tcp-syn-count",
 129                       qstring_from_str(qp->p[i].value));
 130         } else if (!strcmp(qp->p[i].name, "readahead")) {
 131             qdict_put(options, "readahead-size",
 132                       qstring_from_str(qp->p[i].value));
 133         } else if (!strcmp(qp->p[i].name, "pagecache")) {
 134             qdict_put(options, "page-cache-size",
 135                       qstring_from_str(qp->p[i].value));
 136         } else if (!strcmp(qp->p[i].name, "debug")) {
 137             qdict_put(options, "debug",
 138                       qstring_from_str(qp->p[i].value));
 139         } else {
 140             error_setg(errp, "Unknown NFS parameter name: %s",
 141                        qp->p[i].name);
 142             goto out;
 143         }
 144     }
 145     ret = 0;
 146 out:
 147     if (qp) {
 148         query_params_free(qp);
 149     }
 150     if (uri) {
 151         uri_free(uri);
 152     }
 153     return ret;
 154 }
 155
 156 static bool nfs_has_filename_options_conflict(QDict *options, Error **errp)
 157 {
 158     const QDictEntry *qe;
 159
 160     for (qe = qdict_first(options); qe; qe = qdict_next(options, qe)) {
 161         if (!strcmp(qe->key, "host") ||
 162             !strcmp(qe->key, "path") ||
 163             !strcmp(qe->key, "user") ||
 164             !strcmp(qe->key, "group") ||
 165             !strcmp(qe->key, "tcp-syn-count") ||
 166             !strcmp(qe->key, "readahead-size") ||
 167             !strcmp(qe->key, "page-cache-size") ||
 168             !strcmp(qe->key, "debug") ||
 169             strstart(qe->key, "server.", NULL))
 170         {
 171             error_setg(errp, "Option %s cannot be used with a filename",
 172                        qe->key);
 173             return true;
 174         }
 175     }
 176
 177     return false;
 178 }
 179
 180 static void nfs_parse_filename(const char *filename, QDict *options,
 181                                Error **errp)
 182 {
 183     if (nfs_has_filename_options_conflict(options, errp)) {
 184         return;
 185     }
 186
 187     nfs_parse_uri(filename, options, errp);
 188 }
 189
 190 static void nfs_process_read(void *arg);
 191 static void nfs_process_write(void *arg);
 192
 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     nfs_service(client->context, POLLIN);
 211     nfs_set_events(client);
 212 }
 213
 214 static void nfs_process_write(void *arg)
 215 {
 216     NFSClient *client = arg;
 217     nfs_service(client->context, POLLOUT);
 218     nfs_set_events(client);
 219 }
 220
 221 static void nfs_co_init_task(BlockDriverState *bs, NFSRPC *task)
 222 {
 223     *task = (NFSRPC) {
 224         .co             = qemu_coroutine_self(),
 225         .bs             = bs,
 226         .client         = bs->opaque,
 227     };
 228 }
 229
 230 static void nfs_co_generic_bh_cb(void *opaque)
 231 {
 232     NFSRPC *task = opaque;
 233     task->complete = 1;
 234     qemu_coroutine_enter(task->co);
 235 }
 236
 237 static void
 238 nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
 239                   void *private_data)
 240 {
 241     NFSRPC *task = private_data;
 242     task->ret = ret;
 243     assert(!task->st);
 244     if (task->ret > 0 && task->iov) {
 245         if (task->ret <= task->iov->size) {
 246             qemu_iovec_from_buf(task->iov, 0, data, task->ret);
 247         } else {
 248             task->ret = -EIO;
 249         }
 250     }
 251     if (task->ret < 0) {
 252         error_report("NFS Error: %s", nfs_get_error(nfs));
 253     }
 254     aio_bh_schedule_oneshot(task->client->aio_context,
 255                             nfs_co_generic_bh_cb, task);
 256 }
 257
 258 static int coroutine_fn nfs_co_readv(BlockDriverState *bs,
 259                                      int64_t sector_num, int nb_sectors,
 260                                      QEMUIOVector *iov)
 261 {
 262     NFSClient *client = bs->opaque;
 263     NFSRPC task;
 264
 265     nfs_co_init_task(bs, &task);
 266     task.iov = iov;
 267
 268     if (nfs_pread_async(client->context, client->fh,
 269                         sector_num * BDRV_SECTOR_SIZE,
 270                         nb_sectors * BDRV_SECTOR_SIZE,
 271                         nfs_co_generic_cb, &task) != 0) {
 272         return -ENOMEM;
 273     }
 274
 275     nfs_set_events(client);
 276     while (!task.complete) {
 277         qemu_coroutine_yield();
 278     }
 279
 280     if (task.ret < 0) {
 281         return task.ret;
 282     }
 283
 284     /* zero pad short reads */
 285     if (task.ret < iov->size) {
 286         qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret);
 287     }
 288
 289     return 0;
 290 }
 291
 292 static int coroutine_fn nfs_co_writev(BlockDriverState *bs,
 293                                         int64_t sector_num, int nb_sectors,
 294                                         QEMUIOVector *iov)
 295 {
 296     NFSClient *client = bs->opaque;
 297     NFSRPC task;
 298     char *buf = NULL;
 299
 300     nfs_co_init_task(bs, &task);
 301
 302     buf = g_try_malloc(nb_sectors * BDRV_SECTOR_SIZE);
 303     if (nb_sectors && buf == NULL) {
 304         return -ENOMEM;
 305     }
 306
 307     qemu_iovec_to_buf(iov, 0, buf, nb_sectors * BDRV_SECTOR_SIZE);
 308
 309     if (nfs_pwrite_async(client->context, client->fh,
 310                          sector_num * BDRV_SECTOR_SIZE,
 311                          nb_sectors * BDRV_SECTOR_SIZE,
 312                          buf, nfs_co_generic_cb, &task) != 0) {
 313         g_free(buf);
 314         return -ENOMEM;
 315     }
 316
 317     nfs_set_events(client);
 318     while (!task.complete) {
 319         qemu_coroutine_yield();
 320     }
 321
 322     g_free(buf);
 323
 324     if (task.ret != nb_sectors * BDRV_SECTOR_SIZE) {
 325         return task.ret < 0 ? task.ret : -EIO;
 326     }
 327
 328     return 0;
 329 }
 330
 331 static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
 332 {
 333     NFSClient *client = bs->opaque;
 334     NFSRPC task;
 335
 336     nfs_co_init_task(bs, &task);
 337
 338     if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
 339                         &task) != 0) {
 340         return -ENOMEM;
 341     }
 342
 343     nfs_set_events(client);
 344     while (!task.complete) {
 345         qemu_coroutine_yield();
 346     }
 347
 348     return task.ret;
 349 }
 350
 351 static QemuOptsList runtime_opts = {
 352     .name = "nfs",
 353     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 354     .desc = {
 355         {
 356             .name = "path",
 357             .type = QEMU_OPT_STRING,
 358             .help = "Path of the image on the host",
 359         },
 360         {
 361             .name = "uid",
 362             .type = QEMU_OPT_NUMBER,
 363             .help = "UID value to use when talking to the server",
 364         },
 365         {
 366             .name = "gid",
 367             .type = QEMU_OPT_NUMBER,
 368             .help = "GID value to use when talking to the server",
 369         },
 370         {
 371             .name = "tcp-syncnt",
 372             .type = QEMU_OPT_NUMBER,
 373             .help = "Number of SYNs to send during the session establish",
 374         },
 375         {
 376             .name = "readahead",
 377             .type = QEMU_OPT_NUMBER,
 378             .help = "Set the readahead size in bytes",
 379         },
 380         {
 381             .name = "pagecache",
 382             .type = QEMU_OPT_NUMBER,
 383             .help = "Set the pagecache size in bytes",
 384         },
 385         {
 386             .name = "debug",
 387             .type = QEMU_OPT_NUMBER,
 388             .help = "Set the NFS debug level (max 2)",
 389         },
 390         { /* end of list */ }
 391     },
 392 };
 393
 394 static void nfs_detach_aio_context(BlockDriverState *bs)
 395 {
 396     NFSClient *client = bs->opaque;
 397
 398     aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 399                        false, NULL, NULL, NULL, NULL);
 400     client->events = 0;
 401 }
 402
 403 static void nfs_attach_aio_context(BlockDriverState *bs,
 404                                    AioContext *new_context)
 405 {
 406     NFSClient *client = bs->opaque;
 407
 408     client->aio_context = new_context;
 409     nfs_set_events(client);
 410 }
 411
 412 static void nfs_client_close(NFSClient *client)
 413 {
 414     if (client->context) {
 415         if (client->fh) {
 416             nfs_close(client->context, client->fh);
 417         }
 418         aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 419                            false, NULL, NULL, NULL, NULL);
 420         nfs_destroy_context(client->context);
 421     }
 422     memset(client, 0, sizeof(NFSClient));
 423 }
 424
 425 static void nfs_file_close(BlockDriverState *bs)
 426 {
 427     NFSClient *client = bs->opaque;
 428     nfs_client_close(client);
 429 }
 430
 431 static NFSServer *nfs_config(QDict *options, Error **errp)
 432 {
 433     NFSServer *server = NULL;
 434     QDict *addr = NULL;
 435     QObject *crumpled_addr = NULL;
 436     Visitor *iv = NULL;
 437     Error *local_error = NULL;
 438
 439     qdict_extract_subqdict(options, &addr, "server.");
 440     if (!qdict_size(addr)) {
 441         error_setg(errp, "NFS server address missing");
 442         goto out;
 443     }
 444
 445     crumpled_addr = qdict_crumple(addr, errp);
 446     if (!crumpled_addr) {
 447         goto out;
 448     }
 449
 450     iv = qobject_input_visitor_new(crumpled_addr, true);
 451     visit_type_NFSServer(iv, NULL, &server, &local_error);
 452     if (local_error) {
 453         error_propagate(errp, local_error);
 454         goto out;
 455     }
 456
 457 out:
 458     QDECREF(addr);
 459     qobject_decref(crumpled_addr);
 460     visit_free(iv);
 461     return server;
 462 }
 463
 464
 465 static int64_t nfs_client_open(NFSClient *client, QDict *options,
 466                                int flags, Error **errp, int open_flags)
 467 {
 468     int ret = -EINVAL;
 469     QemuOpts *opts = NULL;
 470     Error *local_err = NULL;
 471     struct stat st;
 472     char *file = NULL, *strp = NULL;
 473
 474     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
 475     qemu_opts_absorb_qdict(opts, options, &local_err);
 476     if (local_err) {
 477         error_propagate(errp, local_err);
 478         ret = -EINVAL;
 479         goto fail;
 480     }
 481
 482     client->path = g_strdup(qemu_opt_get(opts, "path"));
 483     if (!client->path) {
 484         ret = -EINVAL;
 485         error_setg(errp, "No path was specified");
 486         goto fail;
 487     }
 488
 489     strp = strrchr(client->path, '/');
 490     if (strp == NULL) {
 491         error_setg(errp, "Invalid URL specified");
 492         goto fail;
 493     }
 494     file = g_strdup(strp);
 495     *strp = 0;
 496
 497     /* Pop the config into our state object, Exit if invalid */
 498     client->server = nfs_config(options, errp);
 499     if (!client->server) {
 500         ret = -EINVAL;
 501         goto fail;
 502     }
 503
 504     client->context = nfs_init_context();
 505     if (client->context == NULL) {
 506         error_setg(errp, "Failed to init NFS context");
 507         goto fail;
 508     }
 509
 510     if (qemu_opt_get(opts, "uid")) {
 511         client->uid = qemu_opt_get_number(opts, "uid", 0);
 512         nfs_set_uid(client->context, client->uid);
 513     }
 514
 515     if (qemu_opt_get(opts, "gid")) {
 516         client->gid = qemu_opt_get_number(opts, "gid", 0);
 517         nfs_set_gid(client->context, client->gid);
 518     }
 519
 520     if (qemu_opt_get(opts, "tcp-syncnt")) {
 521         client->tcp_syncnt = qemu_opt_get_number(opts, "tcp-syncnt", 0);
 522         nfs_set_tcp_syncnt(client->context, client->tcp_syncnt);
 523     }
 524
 525 #ifdef LIBNFS_FEATURE_READAHEAD
 526     if (qemu_opt_get(opts, "readahead")) {
 527         if (open_flags & BDRV_O_NOCACHE) {
 528             error_setg(errp, "Cannot enable NFS readahead "
 529                              "if cache.direct = on");
 530             goto fail;
 531         }
 532         client->readahead = qemu_opt_get_number(opts, "readahead", 0);
 533         if (client->readahead > QEMU_NFS_MAX_READAHEAD_SIZE) {
 534             error_report("NFS Warning: Truncating NFS readahead "
 535                          "size to %d", QEMU_NFS_MAX_READAHEAD_SIZE);
 536             client->readahead = QEMU_NFS_MAX_READAHEAD_SIZE;
 537         }
 538         nfs_set_readahead(client->context, client->readahead);
 539 #ifdef LIBNFS_FEATURE_PAGECACHE
 540         nfs_set_pagecache_ttl(client->context, 0);
 541 #endif
 542         client->cache_used = true;
 543     }
 544 #endif
 545
 546 #ifdef LIBNFS_FEATURE_PAGECACHE
 547     if (qemu_opt_get(opts, "pagecache")) {
 548         if (open_flags & BDRV_O_NOCACHE) {
 549             error_setg(errp, "Cannot enable NFS pagecache "
 550                              "if cache.direct = on");
 551             goto fail;
 552         }
 553         client->pagecache = qemu_opt_get_number(opts, "pagecache", 0);
 554         if (client->pagecache > QEMU_NFS_MAX_PAGECACHE_SIZE) {
 555             error_report("NFS Warning: Truncating NFS pagecache "
 556                          "size to %d pages", QEMU_NFS_MAX_PAGECACHE_SIZE);
 557             client->pagecache = QEMU_NFS_MAX_PAGECACHE_SIZE;
 558         }
 559         nfs_set_pagecache(client->context, client->pagecache);
 560         nfs_set_pagecache_ttl(client->context, 0);
 561         client->cache_used = true;
 562     }
 563 #endif
 564
 565 #ifdef LIBNFS_FEATURE_DEBUG
 566     if (qemu_opt_get(opts, "debug")) {
 567         client->debug = qemu_opt_get_number(opts, "debug", 0);
 568         /* limit the maximum debug level to avoid potential flooding
 569          * of our log files. */
 570         if (client->debug > QEMU_NFS_MAX_DEBUG_LEVEL) {
 571             error_report("NFS Warning: Limiting NFS debug level "
 572                          "to %d", QEMU_NFS_MAX_DEBUG_LEVEL);
 573             client->debug = QEMU_NFS_MAX_DEBUG_LEVEL;
 574         }
 575         nfs_set_debug(client->context, client->debug);
 576     }
 577 #endif
 578
 579     ret = nfs_mount(client->context, client->server->host, client->path);
 580     if (ret < 0) {
 581         error_setg(errp, "Failed to mount nfs share: %s",
 582                    nfs_get_error(client->context));
 583         goto fail;
 584     }
 585
 586     if (flags & O_CREAT) {
 587         ret = nfs_creat(client->context, file, 0600, &client->fh);
 588         if (ret < 0) {
 589             error_setg(errp, "Failed to create file: %s",
 590                        nfs_get_error(client->context));
 591             goto fail;
 592         }
 593     } else {
 594         ret = nfs_open(client->context, file, flags, &client->fh);
 595         if (ret < 0) {
 596             error_setg(errp, "Failed to open file : %s",
 597                        nfs_get_error(client->context));
 598             goto fail;
 599         }
 600     }
 601
 602     ret = nfs_fstat(client->context, client->fh, &st);
 603     if (ret < 0) {
 604         error_setg(errp, "Failed to fstat file: %s",
 605                    nfs_get_error(client->context));
 606         goto fail;
 607     }
 608
 609     ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
 610     client->st_blocks = st.st_blocks;
 611     client->has_zero_init = S_ISREG(st.st_mode);
 612     *strp = '/';
 613     goto out;
 614
 615 fail:
 616     nfs_client_close(client);
 617 out:
 618     qemu_opts_del(opts);
 619     g_free(file);
 620     return ret;
 621 }
 622
 623 static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
 624                          Error **errp) {
 625     NFSClient *client = bs->opaque;
 626     int64_t ret;
 627
 628     client->aio_context = bdrv_get_aio_context(bs);
 629
 630     ret = nfs_client_open(client, options,
 631                           (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
 632                           errp, bs->open_flags);
 633     if (ret < 0) {
 634         return ret;
 635     }
 636     bs->total_sectors = ret;
 637     ret = 0;
 638     return ret;
 639 }
 640
 641 static QemuOptsList nfs_create_opts = {
 642     .name = "nfs-create-opts",
 643     .head = QTAILQ_HEAD_INITIALIZER(nfs_create_opts.head),
 644     .desc = {
 645         {
 646             .name = BLOCK_OPT_SIZE,
 647             .type = QEMU_OPT_SIZE,
 648             .help = "Virtual disk size"
 649         },
 650         { /* end of list */ }
 651     }
 652 };
 653
 654 static int nfs_file_create(const char *url, QemuOpts *opts, Error **errp)
 655 {
 656     int ret = 0;
 657     int64_t total_size = 0;
 658     NFSClient *client = g_new0(NFSClient, 1);
 659     QDict *options = NULL;
 660
 661     client->aio_context = qemu_get_aio_context();
 662
 663     /* Read out options */
 664     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 665                           BDRV_SECTOR_SIZE);
 666
 667     options = qdict_new();
 668     ret = nfs_parse_uri(url, options, errp);
 669     if (ret < 0) {
 670         goto out;
 671     }
 672
 673     ret = nfs_client_open(client, options, O_CREAT, errp, 0);
 674     if (ret < 0) {
 675         goto out;
 676     }
 677     ret = nfs_ftruncate(client->context, client->fh, total_size);
 678     nfs_client_close(client);
 679 out:
 680     QDECREF(options);
 681     g_free(client);
 682     return ret;
 683 }
 684
 685 static int nfs_has_zero_init(BlockDriverState *bs)
 686 {
 687     NFSClient *client = bs->opaque;
 688     return client->has_zero_init;
 689 }
 690
 691 static void
 692 nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
 693                                void *private_data)
 694 {
 695     NFSRPC *task = private_data;
 696     task->ret = ret;
 697     if (task->ret == 0) {
 698         memcpy(task->st, data, sizeof(struct stat));
 699     }
 700     if (task->ret < 0) {
 701         error_report("NFS Error: %s", nfs_get_error(nfs));
 702     }
 703     task->complete = 1;
 704     bdrv_wakeup(task->bs);
 705 }
 706
 707 static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
 708 {
 709     NFSClient *client = bs->opaque;
 710     NFSRPC task = {0};
 711     struct stat st;
 712
 713     if (bdrv_is_read_only(bs) &&
 714         !(bs->open_flags & BDRV_O_NOCACHE)) {
 715         return client->st_blocks * 512;
 716     }
 717
 718     task.bs = bs;
 719     task.st = &st;
 720     if (nfs_fstat_async(client->context, client->fh, nfs_get_allocated_file_size_cb,
 721                         &task) != 0) {
 722         return -ENOMEM;
 723     }
 724
 725     nfs_set_events(client);
 726     BDRV_POLL_WHILE(bs, !task.complete);
 727
 728     return (task.ret < 0 ? task.ret : st.st_blocks * 512);
 729 }
 730
 731 static int nfs_file_truncate(BlockDriverState *bs, int64_t offset)
 732 {
 733     NFSClient *client = bs->opaque;
 734     return nfs_ftruncate(client->context, client->fh, offset);
 735 }
 736
 737 /* Note that this will not re-establish a connection with the NFS server
 738  * - it is effectively a NOP.  */
 739 static int nfs_reopen_prepare(BDRVReopenState *state,
 740                               BlockReopenQueue *queue, Error **errp)
 741 {
 742     NFSClient *client = state->bs->opaque;
 743     struct stat st;
 744     int ret = 0;
 745
 746     if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) {
 747         error_setg(errp, "Cannot open a read-only mount as read-write");
 748         return -EACCES;
 749     }
 750
 751     if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) {
 752         error_setg(errp, "Cannot disable cache if libnfs readahead or"
 753                          " pagecache is enabled");
 754         return -EINVAL;
 755     }
 756
 757     /* Update cache for read-only reopens */
 758     if (!(state->flags & BDRV_O_RDWR)) {
 759         ret = nfs_fstat(client->context, client->fh, &st);
 760         if (ret < 0) {
 761             error_setg(errp, "Failed to fstat file: %s",
 762                        nfs_get_error(client->context));
 763             return ret;
 764         }
 765         client->st_blocks = st.st_blocks;
 766     }
 767
 768     return 0;
 769 }
 770
 771 static void nfs_refresh_filename(BlockDriverState *bs, QDict *options)
 772 {
 773     NFSClient *client = bs->opaque;
 774     QDict *opts = qdict_new();
 775     QObject *server_qdict;
 776     Visitor *ov;
 777
 778     qdict_put(opts, "driver", qstring_from_str("nfs"));
 779
 780     if (client->uid && !client->gid) {
 781         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 782                  "nfs://%s%s?uid=%" PRId64, client->server->host, client->path,
 783                  client->uid);
 784     } else if (!client->uid && client->gid) {
 785         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 786                  "nfs://%s%s?gid=%" PRId64, client->server->host, client->path,
 787                  client->gid);
 788     } else if (client->uid && client->gid) {
 789         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 790                  "nfs://%s%s?uid=%" PRId64 "&gid=%" PRId64,
 791                  client->server->host, client->path, client->uid, client->gid);
 792     } else {
 793         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 794                  "nfs://%s%s", client->server->host, client->path);
 795     }
 796
 797     ov = qobject_output_visitor_new(&server_qdict);
 798     visit_type_NFSServer(ov, NULL, &client->server, &error_abort);
 799     visit_complete(ov, &server_qdict);
 800     assert(qobject_type(server_qdict) == QTYPE_QDICT);
 801
 802     qdict_put_obj(opts, "server", server_qdict);
 803     qdict_put(opts, "path", qstring_from_str(client->path));
 804
 805     if (client->uid) {
 806         qdict_put(opts, "uid", qint_from_int(client->uid));
 807     }
 808     if (client->gid) {
 809         qdict_put(opts, "gid", qint_from_int(client->gid));
 810     }
 811     if (client->tcp_syncnt) {
 812         qdict_put(opts, "tcp-syncnt",
 813                       qint_from_int(client->tcp_syncnt));
 814     }
 815     if (client->readahead) {
 816         qdict_put(opts, "readahead",
 817                       qint_from_int(client->readahead));
 818     }
 819     if (client->pagecache) {
 820         qdict_put(opts, "pagecache",
 821                       qint_from_int(client->pagecache));
 822     }
 823     if (client->debug) {
 824         qdict_put(opts, "debug", qint_from_int(client->debug));
 825     }
 826
 827     visit_free(ov);
 828     qdict_flatten(opts);
 829     bs->full_open_options = opts;
 830 }
 831
 832 #ifdef LIBNFS_FEATURE_PAGECACHE
 833 static void nfs_invalidate_cache(BlockDriverState *bs,
 834                                  Error **errp)
 835 {
 836     NFSClient *client = bs->opaque;
 837     nfs_pagecache_invalidate(client->context, client->fh);
 838 }
 839 #endif
 840
 841 static BlockDriver bdrv_nfs = {
 842     .format_name                    = "nfs",
 843     .protocol_name                  = "nfs",
 844
 845     .instance_size                  = sizeof(NFSClient),
 846     .bdrv_parse_filename            = nfs_parse_filename,
 847     .create_opts                    = &nfs_create_opts,
 848
 849     .bdrv_has_zero_init             = nfs_has_zero_init,
 850     .bdrv_get_allocated_file_size   = nfs_get_allocated_file_size,
 851     .bdrv_truncate                  = nfs_file_truncate,
 852
 853     .bdrv_file_open                 = nfs_file_open,
 854     .bdrv_close                     = nfs_file_close,
 855     .bdrv_create                    = nfs_file_create,
 856     .bdrv_reopen_prepare            = nfs_reopen_prepare,
 857
 858     .bdrv_co_readv                  = nfs_co_readv,
 859     .bdrv_co_writev                 = nfs_co_writev,
 860     .bdrv_co_flush_to_disk          = nfs_co_flush,
 861
 862     .bdrv_detach_aio_context        = nfs_detach_aio_context,
 863     .bdrv_attach_aio_context        = nfs_attach_aio_context,
 864     .bdrv_refresh_filename          = nfs_refresh_filename,
 865
 866 #ifdef LIBNFS_FEATURE_PAGECACHE
 867     .bdrv_invalidate_cache          = nfs_invalidate_cache,
 868 #endif
 869 };
 870
 871 static void nfs_block_init(void)
 872 {
 873     bdrv_register(&bdrv_nfs);
 874 }
 875
 876 block_init(nfs_block_init);