block/nfs.c

   1 /*
   2  * QEMU Block driver for native access to files on NFS shares
   3  *
   4  * Copyright (c) 2014-2017 Peter Lieven <pl@kamp.de>
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24
  25 #include "qemu/osdep.h"
  26
  27 #include <poll.h>
  28 #include "qemu/config-file.h"
  29 #include "qemu/error-report.h"
  30 #include "qapi/error.h"
  31 #include "block/block_int.h"
  32 #include "block/qdict.h"
  33 #include "trace.h"
  34 #include "qemu/iov.h"
  35 #include "qemu/module.h"
  36 #include "qemu/option.h"
  37 #include "qemu/uri.h"
  38 #include "qemu/cutils.h"
  39 #include "sysemu/sysemu.h"
  40 #include "qapi/qapi-visit-block-core.h"
  41 #include "qapi/qmp/qdict.h"
  42 #include "qapi/qmp/qstring.h"
  43 #include "qapi/qobject-input-visitor.h"
  44 #include "qapi/qobject-output-visitor.h"
  45 #include <nfsc/libnfs.h>
  46
  47
  48 #define QEMU_NFS_MAX_READAHEAD_SIZE 1048576
  49 #define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE)
  50 #define QEMU_NFS_MAX_DEBUG_LEVEL 2
  51
  52 typedef struct NFSClient {
  53     struct nfs_context *context;
  54     struct nfsfh *fh;
  55     int events;
  56     bool has_zero_init;
  57     AioContext *aio_context;
  58     QemuMutex mutex;
  59     blkcnt_t st_blocks;
  60     bool cache_used;
  61     NFSServer *server;
  62     char *path;
  63     int64_t uid, gid, tcp_syncnt, readahead, pagecache, debug;
  64 } NFSClient;
  65
  66 typedef struct NFSRPC {
  67     BlockDriverState *bs;
  68     int ret;
  69     int complete;
  70     QEMUIOVector *iov;
  71     struct stat *st;
  72     Coroutine *co;
  73     NFSClient *client;
  74 } NFSRPC;
  75
  76 static int nfs_parse_uri(const char *filename, QDict *options, Error **errp)
  77 {
  78     URI *uri = NULL;
  79     QueryParams *qp = NULL;
  80     int ret = -EINVAL, i;
  81
  82     uri = uri_parse(filename);
  83     if (!uri) {
  84         error_setg(errp, "Invalid URI specified");
  85         goto out;
  86     }
  87     if (g_strcmp0(uri->scheme, "nfs") != 0) {
  88         error_setg(errp, "URI scheme must be 'nfs'");
  89         goto out;
  90     }
  91
  92     if (!uri->server) {
  93         error_setg(errp, "missing hostname in URI");
  94         goto out;
  95     }
  96
  97     if (!uri->path) {
  98         error_setg(errp, "missing file path in URI");
  99         goto out;
 100     }
 101
 102     qp = query_params_parse(uri->query);
 103     if (!qp) {
 104         error_setg(errp, "could not parse query parameters");
 105         goto out;
 106     }
 107
 108     qdict_put_str(options, "server.host", uri->server);
 109     qdict_put_str(options, "server.type", "inet");
 110     qdict_put_str(options, "path", uri->path);
 111
 112     for (i = 0; i < qp->n; i++) {
 113         unsigned long long val;
 114         if (!qp->p[i].value) {
 115             error_setg(errp, "Value for NFS parameter expected: %s",
 116                        qp->p[i].name);
 117             goto out;
 118         }
 119         if (parse_uint_full(qp->p[i].value, &val, 0)) {
 120             error_setg(errp, "Illegal value for NFS parameter: %s",
 121                        qp->p[i].name);
 122             goto out;
 123         }
 124         if (!strcmp(qp->p[i].name, "uid")) {
 125             qdict_put_str(options, "user", qp->p[i].value);
 126         } else if (!strcmp(qp->p[i].name, "gid")) {
 127             qdict_put_str(options, "group", qp->p[i].value);
 128         } else if (!strcmp(qp->p[i].name, "tcp-syncnt")) {
 129             qdict_put_str(options, "tcp-syn-count", qp->p[i].value);
 130         } else if (!strcmp(qp->p[i].name, "readahead")) {
 131             qdict_put_str(options, "readahead-size", qp->p[i].value);
 132         } else if (!strcmp(qp->p[i].name, "pagecache")) {
 133             qdict_put_str(options, "page-cache-size", qp->p[i].value);
 134         } else if (!strcmp(qp->p[i].name, "debug")) {
 135             qdict_put_str(options, "debug", qp->p[i].value);
 136         } else {
 137             error_setg(errp, "Unknown NFS parameter name: %s",
 138                        qp->p[i].name);
 139             goto out;
 140         }
 141     }
 142     ret = 0;
 143 out:
 144     if (qp) {
 145         query_params_free(qp);
 146     }
 147     if (uri) {
 148         uri_free(uri);
 149     }
 150     return ret;
 151 }
 152
 153 static bool nfs_has_filename_options_conflict(QDict *options, Error **errp)
 154 {
 155     const QDictEntry *qe;
 156
 157     for (qe = qdict_first(options); qe; qe = qdict_next(options, qe)) {
 158         if (!strcmp(qe->key, "host") ||
 159             !strcmp(qe->key, "path") ||
 160             !strcmp(qe->key, "user") ||
 161             !strcmp(qe->key, "group") ||
 162             !strcmp(qe->key, "tcp-syn-count") ||
 163             !strcmp(qe->key, "readahead-size") ||
 164             !strcmp(qe->key, "page-cache-size") ||
 165             !strcmp(qe->key, "debug") ||
 166             strstart(qe->key, "server.", NULL))
 167         {
 168             error_setg(errp, "Option %s cannot be used with a filename",
 169                        qe->key);
 170             return true;
 171         }
 172     }
 173
 174     return false;
 175 }
 176
 177 static void nfs_parse_filename(const char *filename, QDict *options,
 178                                Error **errp)
 179 {
 180     if (nfs_has_filename_options_conflict(options, errp)) {
 181         return;
 182     }
 183
 184     nfs_parse_uri(filename, options, errp);
 185 }
 186
 187 static void nfs_process_read(void *arg);
 188 static void nfs_process_write(void *arg);
 189
 190 /* Called with QemuMutex held.  */
 191 static void nfs_set_events(NFSClient *client)
 192 {
 193     int ev = nfs_which_events(client->context);
 194     if (ev != client->events) {
 195         aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 196                            false,
 197                            (ev & POLLIN) ? nfs_process_read : NULL,
 198                            (ev & POLLOUT) ? nfs_process_write : NULL,
 199                            NULL, client);
 200
 201     }
 202     client->events = ev;
 203 }
 204
 205 static void nfs_process_read(void *arg)
 206 {
 207     NFSClient *client = arg;
 208
 209     qemu_mutex_lock(&client->mutex);
 210     nfs_service(client->context, POLLIN);
 211     nfs_set_events(client);
 212     qemu_mutex_unlock(&client->mutex);
 213 }
 214
 215 static void nfs_process_write(void *arg)
 216 {
 217     NFSClient *client = arg;
 218
 219     qemu_mutex_lock(&client->mutex);
 220     nfs_service(client->context, POLLOUT);
 221     nfs_set_events(client);
 222     qemu_mutex_unlock(&client->mutex);
 223 }
 224
 225 static void nfs_co_init_task(BlockDriverState *bs, NFSRPC *task)
 226 {
 227     *task = (NFSRPC) {
 228         .co             = qemu_coroutine_self(),
 229         .bs             = bs,
 230         .client         = bs->opaque,
 231     };
 232 }
 233
 234 static void nfs_co_generic_bh_cb(void *opaque)
 235 {
 236     NFSRPC *task = opaque;
 237
 238     task->complete = 1;
 239     aio_co_wake(task->co);
 240 }
 241
 242 /* Called (via nfs_service) with QemuMutex held.  */
 243 static void
 244 nfs_co_generic_cb(int ret, struct nfs_context *nfs, void *data,
 245                   void *private_data)
 246 {
 247     NFSRPC *task = private_data;
 248     task->ret = ret;
 249     assert(!task->st);
 250     if (task->ret > 0 && task->iov) {
 251         if (task->ret <= task->iov->size) {
 252             qemu_iovec_from_buf(task->iov, 0, data, task->ret);
 253         } else {
 254             task->ret = -EIO;
 255         }
 256     }
 257     if (task->ret < 0) {
 258         error_report("NFS Error: %s", nfs_get_error(nfs));
 259     }
 260     aio_bh_schedule_oneshot(task->client->aio_context,
 261                             nfs_co_generic_bh_cb, task);
 262 }
 263
 264 static int coroutine_fn nfs_co_preadv(BlockDriverState *bs, uint64_t offset,
 265                                       uint64_t bytes, QEMUIOVector *iov,
 266                                       int flags)
 267 {
 268     NFSClient *client = bs->opaque;
 269     NFSRPC task;
 270
 271     nfs_co_init_task(bs, &task);
 272     task.iov = iov;
 273
 274     qemu_mutex_lock(&client->mutex);
 275     if (nfs_pread_async(client->context, client->fh,
 276                         offset, bytes, nfs_co_generic_cb, &task) != 0) {
 277         qemu_mutex_unlock(&client->mutex);
 278         return -ENOMEM;
 279     }
 280
 281     nfs_set_events(client);
 282     qemu_mutex_unlock(&client->mutex);
 283     while (!task.complete) {
 284         qemu_coroutine_yield();
 285     }
 286
 287     if (task.ret < 0) {
 288         return task.ret;
 289     }
 290
 291     /* zero pad short reads */
 292     if (task.ret < iov->size) {
 293         qemu_iovec_memset(iov, task.ret, 0, iov->size - task.ret);
 294     }
 295
 296     return 0;
 297 }
 298
 299 static int coroutine_fn nfs_co_pwritev(BlockDriverState *bs, uint64_t offset,
 300                                        uint64_t bytes, QEMUIOVector *iov,
 301                                        int flags)
 302 {
 303     NFSClient *client = bs->opaque;
 304     NFSRPC task;
 305     char *buf = NULL;
 306     bool my_buffer = false;
 307
 308     nfs_co_init_task(bs, &task);
 309
 310     if (iov->niov != 1) {
 311         buf = g_try_malloc(bytes);
 312         if (bytes && buf == NULL) {
 313             return -ENOMEM;
 314         }
 315         qemu_iovec_to_buf(iov, 0, buf, bytes);
 316         my_buffer = true;
 317     } else {
 318         buf = iov->iov[0].iov_base;
 319     }
 320
 321     qemu_mutex_lock(&client->mutex);
 322     if (nfs_pwrite_async(client->context, client->fh,
 323                          offset, bytes, buf,
 324                          nfs_co_generic_cb, &task) != 0) {
 325         qemu_mutex_unlock(&client->mutex);
 326         if (my_buffer) {
 327             g_free(buf);
 328         }
 329         return -ENOMEM;
 330     }
 331
 332     nfs_set_events(client);
 333     qemu_mutex_unlock(&client->mutex);
 334     while (!task.complete) {
 335         qemu_coroutine_yield();
 336     }
 337
 338     if (my_buffer) {
 339         g_free(buf);
 340     }
 341
 342     if (task.ret != bytes) {
 343         return task.ret < 0 ? task.ret : -EIO;
 344     }
 345
 346     return 0;
 347 }
 348
 349 static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
 350 {
 351     NFSClient *client = bs->opaque;
 352     NFSRPC task;
 353
 354     nfs_co_init_task(bs, &task);
 355
 356     qemu_mutex_lock(&client->mutex);
 357     if (nfs_fsync_async(client->context, client->fh, nfs_co_generic_cb,
 358                         &task) != 0) {
 359         qemu_mutex_unlock(&client->mutex);
 360         return -ENOMEM;
 361     }
 362
 363     nfs_set_events(client);
 364     qemu_mutex_unlock(&client->mutex);
 365     while (!task.complete) {
 366         qemu_coroutine_yield();
 367     }
 368
 369     return task.ret;
 370 }
 371
 372 static void nfs_detach_aio_context(BlockDriverState *bs)
 373 {
 374     NFSClient *client = bs->opaque;
 375
 376     aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 377                        false, NULL, NULL, NULL, NULL);
 378     client->events = 0;
 379 }
 380
 381 static void nfs_attach_aio_context(BlockDriverState *bs,
 382                                    AioContext *new_context)
 383 {
 384     NFSClient *client = bs->opaque;
 385
 386     client->aio_context = new_context;
 387     nfs_set_events(client);
 388 }
 389
 390 static void nfs_client_close(NFSClient *client)
 391 {
 392     if (client->context) {
 393         if (client->fh) {
 394             nfs_close(client->context, client->fh);
 395             client->fh = NULL;
 396         }
 397         aio_set_fd_handler(client->aio_context, nfs_get_fd(client->context),
 398                            false, NULL, NULL, NULL, NULL);
 399         nfs_destroy_context(client->context);
 400         client->context = NULL;
 401     }
 402     g_free(client->path);
 403     qemu_mutex_destroy(&client->mutex);
 404     qapi_free_NFSServer(client->server);
 405     client->server = NULL;
 406 }
 407
 408 static void nfs_file_close(BlockDriverState *bs)
 409 {
 410     NFSClient *client = bs->opaque;
 411     nfs_client_close(client);
 412 }
 413
 414 static int64_t nfs_client_open(NFSClient *client, BlockdevOptionsNfs *opts,
 415                                int flags, int open_flags, Error **errp)
 416 {
 417     int64_t ret = -EINVAL;
 418     struct stat st;
 419     char *file = NULL, *strp = NULL;
 420
 421     qemu_mutex_init(&client->mutex);
 422
 423     client->path = g_strdup(opts->path);
 424
 425     strp = strrchr(client->path, '/');
 426     if (strp == NULL) {
 427         error_setg(errp, "Invalid URL specified");
 428         goto fail;
 429     }
 430     file = g_strdup(strp);
 431     *strp = 0;
 432
 433     /* Steal the NFSServer object from opts; set the original pointer to NULL
 434      * to avoid use after free and double free. */
 435     client->server = opts->server;
 436     opts->server = NULL;
 437
 438     client->context = nfs_init_context();
 439     if (client->context == NULL) {
 440         error_setg(errp, "Failed to init NFS context");
 441         goto fail;
 442     }
 443
 444     if (opts->has_user) {
 445         client->uid = opts->user;
 446         nfs_set_uid(client->context, client->uid);
 447     }
 448
 449     if (opts->has_group) {
 450         client->gid = opts->group;
 451         nfs_set_gid(client->context, client->gid);
 452     }
 453
 454     if (opts->has_tcp_syn_count) {
 455         client->tcp_syncnt = opts->tcp_syn_count;
 456         nfs_set_tcp_syncnt(client->context, client->tcp_syncnt);
 457     }
 458
 459 #ifdef LIBNFS_FEATURE_READAHEAD
 460     if (opts->has_readahead_size) {
 461         if (open_flags & BDRV_O_NOCACHE) {
 462             error_setg(errp, "Cannot enable NFS readahead "
 463                              "if cache.direct = on");
 464             goto fail;
 465         }
 466         client->readahead = opts->readahead_size;
 467         if (client->readahead > QEMU_NFS_MAX_READAHEAD_SIZE) {
 468             warn_report("Truncating NFS readahead size to %d",
 469                         QEMU_NFS_MAX_READAHEAD_SIZE);
 470             client->readahead = QEMU_NFS_MAX_READAHEAD_SIZE;
 471         }
 472         nfs_set_readahead(client->context, client->readahead);
 473 #ifdef LIBNFS_FEATURE_PAGECACHE
 474         nfs_set_pagecache_ttl(client->context, 0);
 475 #endif
 476         client->cache_used = true;
 477     }
 478 #endif
 479
 480 #ifdef LIBNFS_FEATURE_PAGECACHE
 481     if (opts->has_page_cache_size) {
 482         if (open_flags & BDRV_O_NOCACHE) {
 483             error_setg(errp, "Cannot enable NFS pagecache "
 484                              "if cache.direct = on");
 485             goto fail;
 486         }
 487         client->pagecache = opts->page_cache_size;
 488         if (client->pagecache > QEMU_NFS_MAX_PAGECACHE_SIZE) {
 489             warn_report("Truncating NFS pagecache size to %d pages",
 490                         QEMU_NFS_MAX_PAGECACHE_SIZE);
 491             client->pagecache = QEMU_NFS_MAX_PAGECACHE_SIZE;
 492         }
 493         nfs_set_pagecache(client->context, client->pagecache);
 494         nfs_set_pagecache_ttl(client->context, 0);
 495         client->cache_used = true;
 496     }
 497 #endif
 498
 499 #ifdef LIBNFS_FEATURE_DEBUG
 500     if (opts->has_debug) {
 501         client->debug = opts->debug;
 502         /* limit the maximum debug level to avoid potential flooding
 503          * of our log files. */
 504         if (client->debug > QEMU_NFS_MAX_DEBUG_LEVEL) {
 505             warn_report("Limiting NFS debug level to %d",
 506                         QEMU_NFS_MAX_DEBUG_LEVEL);
 507             client->debug = QEMU_NFS_MAX_DEBUG_LEVEL;
 508         }
 509         nfs_set_debug(client->context, client->debug);
 510     }
 511 #endif
 512
 513     ret = nfs_mount(client->context, client->server->host, client->path);
 514     if (ret < 0) {
 515         error_setg(errp, "Failed to mount nfs share: %s",
 516                    nfs_get_error(client->context));
 517         goto fail;
 518     }
 519
 520     if (flags & O_CREAT) {
 521         ret = nfs_creat(client->context, file, 0600, &client->fh);
 522         if (ret < 0) {
 523             error_setg(errp, "Failed to create file: %s",
 524                        nfs_get_error(client->context));
 525             goto fail;
 526         }
 527     } else {
 528         ret = nfs_open(client->context, file, flags, &client->fh);
 529         if (ret < 0) {
 530             error_setg(errp, "Failed to open file : %s",
 531                        nfs_get_error(client->context));
 532             goto fail;
 533         }
 534     }
 535
 536     ret = nfs_fstat(client->context, client->fh, &st);
 537     if (ret < 0) {
 538         error_setg(errp, "Failed to fstat file: %s",
 539                    nfs_get_error(client->context));
 540         goto fail;
 541     }
 542
 543     ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
 544     client->st_blocks = st.st_blocks;
 545     client->has_zero_init = S_ISREG(st.st_mode);
 546     *strp = '/';
 547     goto out;
 548
 549 fail:
 550     nfs_client_close(client);
 551 out:
 552     g_free(file);
 553     return ret;
 554 }
 555
 556 static BlockdevOptionsNfs *nfs_options_qdict_to_qapi(QDict *options,
 557                                                      Error **errp)
 558 {
 559     BlockdevOptionsNfs *opts = NULL;
 560     Visitor *v;
 561     const QDictEntry *e;
 562     Error *local_err = NULL;
 563
 564     v = qobject_input_visitor_new_flat_confused(options, errp);
 565     if (!v) {
 566         return NULL;
 567     }
 568
 569     visit_type_BlockdevOptionsNfs(v, NULL, &opts, &local_err);
 570     visit_free(v);
 571
 572     if (local_err) {
 573         error_propagate(errp, local_err);
 574         return NULL;
 575     }
 576
 577     /* Remove the processed options from the QDict (the visitor processes
 578      * _all_ options in the QDict) */
 579     while ((e = qdict_first(options))) {
 580         qdict_del(options, e->key);
 581     }
 582
 583     return opts;
 584 }
 585
 586 static int64_t nfs_client_open_qdict(NFSClient *client, QDict *options,
 587                                      int flags, int open_flags, Error **errp)
 588 {
 589     BlockdevOptionsNfs *opts;
 590     int ret;
 591
 592     opts = nfs_options_qdict_to_qapi(options, errp);
 593     if (opts == NULL) {
 594         ret = -EINVAL;
 595         goto fail;
 596     }
 597
 598     ret = nfs_client_open(client, opts, flags, open_flags, errp);
 599 fail:
 600     qapi_free_BlockdevOptionsNfs(opts);
 601     return ret;
 602 }
 603
 604 static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
 605                          Error **errp) {
 606     NFSClient *client = bs->opaque;
 607     int64_t ret;
 608
 609     client->aio_context = bdrv_get_aio_context(bs);
 610
 611     ret = nfs_client_open_qdict(client, options,
 612                                 (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
 613                                 bs->open_flags, errp);
 614     if (ret < 0) {
 615         return ret;
 616     }
 617
 618     bs->total_sectors = ret;
 619     ret = 0;
 620     return ret;
 621 }
 622
 623 static QemuOptsList nfs_create_opts = {
 624     .name = "nfs-create-opts",
 625     .head = QTAILQ_HEAD_INITIALIZER(nfs_create_opts.head),
 626     .desc = {
 627         {
 628             .name = BLOCK_OPT_SIZE,
 629             .type = QEMU_OPT_SIZE,
 630             .help = "Virtual disk size"
 631         },
 632         { /* end of list */ }
 633     }
 634 };
 635
 636 static int nfs_file_co_create(BlockdevCreateOptions *options, Error **errp)
 637 {
 638     BlockdevCreateOptionsNfs *opts = &options->u.nfs;
 639     NFSClient *client = g_new0(NFSClient, 1);
 640     int ret;
 641
 642     assert(options->driver == BLOCKDEV_DRIVER_NFS);
 643
 644     client->aio_context = qemu_get_aio_context();
 645
 646     ret = nfs_client_open(client, opts->location, O_CREAT, 0, errp);
 647     if (ret < 0) {
 648         goto out;
 649     }
 650     ret = nfs_ftruncate(client->context, client->fh, opts->size);
 651     nfs_client_close(client);
 652
 653 out:
 654     g_free(client);
 655     return ret;
 656 }
 657
 658 static int coroutine_fn nfs_file_co_create_opts(const char *url, QemuOpts *opts,
 659                                                 Error **errp)
 660 {
 661     BlockdevCreateOptions *create_options;
 662     BlockdevCreateOptionsNfs *nfs_opts;
 663     QDict *options;
 664     int ret;
 665
 666     create_options = g_new0(BlockdevCreateOptions, 1);
 667     create_options->driver = BLOCKDEV_DRIVER_NFS;
 668     nfs_opts = &create_options->u.nfs;
 669
 670     /* Read out options */
 671     nfs_opts->size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
 672                               BDRV_SECTOR_SIZE);
 673
 674     options = qdict_new();
 675     ret = nfs_parse_uri(url, options, errp);
 676     if (ret < 0) {
 677         goto out;
 678     }
 679
 680     nfs_opts->location = nfs_options_qdict_to_qapi(options, errp);
 681     if (nfs_opts->location == NULL) {
 682         ret = -EINVAL;
 683         goto out;
 684     }
 685
 686     ret = nfs_file_co_create(create_options, errp);
 687     if (ret < 0) {
 688         goto out;
 689     }
 690
 691     ret = 0;
 692 out:
 693     qobject_unref(options);
 694     qapi_free_BlockdevCreateOptions(create_options);
 695     return ret;
 696 }
 697
 698 static int nfs_has_zero_init(BlockDriverState *bs)
 699 {
 700     NFSClient *client = bs->opaque;
 701     return client->has_zero_init;
 702 }
 703
 704 /* Called (via nfs_service) with QemuMutex held.  */
 705 static void
 706 nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
 707                                void *private_data)
 708 {
 709     NFSRPC *task = private_data;
 710     task->ret = ret;
 711     if (task->ret == 0) {
 712         memcpy(task->st, data, sizeof(struct stat));
 713     }
 714     if (task->ret < 0) {
 715         error_report("NFS Error: %s", nfs_get_error(nfs));
 716     }
 717
 718     /* Set task->complete before reading bs->wakeup.  */
 719     atomic_mb_set(&task->complete, 1);
 720     bdrv_wakeup(task->bs);
 721 }
 722
 723 static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
 724 {
 725     NFSClient *client = bs->opaque;
 726     NFSRPC task = {0};
 727     struct stat st;
 728
 729     if (bdrv_is_read_only(bs) &&
 730         !(bs->open_flags & BDRV_O_NOCACHE)) {
 731         return client->st_blocks * 512;
 732     }
 733
 734     task.bs = bs;
 735     task.st = &st;
 736     if (nfs_fstat_async(client->context, client->fh, nfs_get_allocated_file_size_cb,
 737                         &task) != 0) {
 738         return -ENOMEM;
 739     }
 740
 741     nfs_set_events(client);
 742     BDRV_POLL_WHILE(bs, !task.complete);
 743
 744     return (task.ret < 0 ? task.ret : st.st_blocks * 512);
 745 }
 746
 747 static int coroutine_fn
 748 nfs_file_co_truncate(BlockDriverState *bs, int64_t offset,
 749                      PreallocMode prealloc, Error **errp)
 750 {
 751     NFSClient *client = bs->opaque;
 752     int ret;
 753
 754     if (prealloc != PREALLOC_MODE_OFF) {
 755         error_setg(errp, "Unsupported preallocation mode '%s'",
 756                    PreallocMode_str(prealloc));
 757         return -ENOTSUP;
 758     }
 759
 760     ret = nfs_ftruncate(client->context, client->fh, offset);
 761     if (ret < 0) {
 762         error_setg_errno(errp, -ret, "Failed to truncate file");
 763         return ret;
 764     }
 765
 766     return 0;
 767 }
 768
 769 /* Note that this will not re-establish a connection with the NFS server
 770  * - it is effectively a NOP.  */
 771 static int nfs_reopen_prepare(BDRVReopenState *state,
 772                               BlockReopenQueue *queue, Error **errp)
 773 {
 774     NFSClient *client = state->bs->opaque;
 775     struct stat st;
 776     int ret = 0;
 777
 778     if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) {
 779         error_setg(errp, "Cannot open a read-only mount as read-write");
 780         return -EACCES;
 781     }
 782
 783     if ((state->flags & BDRV_O_NOCACHE) && client->cache_used) {
 784         error_setg(errp, "Cannot disable cache if libnfs readahead or"
 785                          " pagecache is enabled");
 786         return -EINVAL;
 787     }
 788
 789     /* Update cache for read-only reopens */
 790     if (!(state->flags & BDRV_O_RDWR)) {
 791         ret = nfs_fstat(client->context, client->fh, &st);
 792         if (ret < 0) {
 793             error_setg(errp, "Failed to fstat file: %s",
 794                        nfs_get_error(client->context));
 795             return ret;
 796         }
 797         client->st_blocks = st.st_blocks;
 798     }
 799
 800     return 0;
 801 }
 802
 803 static void nfs_refresh_filename(BlockDriverState *bs)
 804 {
 805     NFSClient *client = bs->opaque;
 806
 807     if (client->uid && !client->gid) {
 808         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 809                  "nfs://%s%s?uid=%" PRId64, client->server->host, client->path,
 810                  client->uid);
 811     } else if (!client->uid && client->gid) {
 812         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 813                  "nfs://%s%s?gid=%" PRId64, client->server->host, client->path,
 814                  client->gid);
 815     } else if (client->uid && client->gid) {
 816         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 817                  "nfs://%s%s?uid=%" PRId64 "&gid=%" PRId64,
 818                  client->server->host, client->path, client->uid, client->gid);
 819     } else {
 820         snprintf(bs->exact_filename, sizeof(bs->exact_filename),
 821                  "nfs://%s%s", client->server->host, client->path);
 822     }
 823 }
 824
 825 static char *nfs_dirname(BlockDriverState *bs, Error **errp)
 826 {
 827     NFSClient *client = bs->opaque;
 828
 829     if (client->uid || client->gid) {
 830         bdrv_refresh_filename(bs);
 831         error_setg(errp, "Cannot generate a base directory for NFS node '%s'",
 832                    bs->filename);
 833         return NULL;
 834     }
 835
 836     return g_strdup_printf("nfs://%s%s/", client->server->host, client->path);
 837 }
 838
 839 #ifdef LIBNFS_FEATURE_PAGECACHE
 840 static void coroutine_fn nfs_co_invalidate_cache(BlockDriverState *bs,
 841                                                  Error **errp)
 842 {
 843     NFSClient *client = bs->opaque;
 844     nfs_pagecache_invalidate(client->context, client->fh);
 845 }
 846 #endif
 847
 848 static const char *nfs_strong_runtime_opts[] = {
 849     "path",
 850     "user",
 851     "group",
 852     "server.",
 853
 854     NULL
 855 };
 856
 857 static BlockDriver bdrv_nfs = {
 858     .format_name                    = "nfs",
 859     .protocol_name                  = "nfs",
 860
 861     .instance_size                  = sizeof(NFSClient),
 862     .bdrv_parse_filename            = nfs_parse_filename,
 863     .create_opts                    = &nfs_create_opts,
 864
 865     .bdrv_has_zero_init             = nfs_has_zero_init,
 866     .bdrv_get_allocated_file_size   = nfs_get_allocated_file_size,
 867     .bdrv_co_truncate               = nfs_file_co_truncate,
 868
 869     .bdrv_file_open                 = nfs_file_open,
 870     .bdrv_close                     = nfs_file_close,
 871     .bdrv_co_create                 = nfs_file_co_create,
 872     .bdrv_co_create_opts            = nfs_file_co_create_opts,
 873     .bdrv_reopen_prepare            = nfs_reopen_prepare,
 874
 875     .bdrv_co_preadv                 = nfs_co_preadv,
 876     .bdrv_co_pwritev                = nfs_co_pwritev,
 877     .bdrv_co_flush_to_disk          = nfs_co_flush,
 878
 879     .bdrv_detach_aio_context        = nfs_detach_aio_context,
 880     .bdrv_attach_aio_context        = nfs_attach_aio_context,
 881     .bdrv_refresh_filename          = nfs_refresh_filename,
 882     .bdrv_dirname                   = nfs_dirname,
 883
 884     .strong_runtime_opts            = nfs_strong_runtime_opts,
 885
 886 #ifdef LIBNFS_FEATURE_PAGECACHE
 887     .bdrv_co_invalidate_cache       = nfs_co_invalidate_cache,
 888 #endif
 889 };
 890
 891 static void nfs_block_init(void)
 892 {
 893     bdrv_register(&bdrv_nfs);
 894 }
 895
 896 block_init(nfs_block_init);