block/gluster.c

   1 /*
   2  * GlusterFS backend for QEMU
   3  *
   4  * Copyright (C) 2012 Bharata B Rao <[email protected]>
   5  *
   6  * Pipe handling mechanism in AIO implementation is derived from
   7  * block/rbd.c. Hence,
   8  *
   9  * Copyright (C) 2010-2011 Christian Brunner <[email protected]>,
  10  *                         Josh Durgin <[email protected]>
  11  *
  12  * This work is licensed under the terms of the GNU GPL, version 2.  See
  13  * the COPYING file in the top-level directory.
  14  *
  15  * Contributions after 2012-01-13 are licensed under the terms of the
  16  * GNU GPL, version 2 or (at your option) any later version.
  17  */
  18 #include <glusterfs/api/glfs.h>
  19 #include "block/block_int.h"
  20 #include "qemu/sockets.h"
  21 #include "qemu/uri.h"
  22
  23 typedef struct GlusterAIOCB {
  24     BlockDriverAIOCB common;
  25     int64_t size;
  26     int ret;
  27     bool *finished;
  28     QEMUBH *bh;
  29 } GlusterAIOCB;
  30
  31 typedef struct BDRVGlusterState {
  32     struct glfs *glfs;
  33     int fds[2];
  34     struct glfs_fd *fd;
  35     int event_reader_pos;
  36     GlusterAIOCB *event_acb;
  37 } BDRVGlusterState;
  38
  39 #define GLUSTER_FD_READ  0
  40 #define GLUSTER_FD_WRITE 1
  41
  42 typedef struct GlusterConf {
  43     char *server;
  44     int port;
  45     char *volname;
  46     char *image;
  47     char *transport;
  48 } GlusterConf;
  49
  50 static void qemu_gluster_gconf_free(GlusterConf *gconf)
  51 {
  52     g_free(gconf->server);
  53     g_free(gconf->volname);
  54     g_free(gconf->image);
  55     g_free(gconf->transport);
  56     g_free(gconf);
  57 }
  58
  59 static int parse_volume_options(GlusterConf *gconf, char *path)
  60 {
  61     char *p, *q;
  62
  63     if (!path) {
  64         return -EINVAL;
  65     }
  66
  67     /* volume */
  68     p = q = path + strspn(path, "/");
  69     p += strcspn(p, "/");
  70     if (*p == '\0') {
  71         return -EINVAL;
  72     }
  73     gconf->volname = g_strndup(q, p - q);
  74
  75     /* image */
  76     p += strspn(p, "/");
  77     if (*p == '\0') {
  78         return -EINVAL;
  79     }
  80     gconf->image = g_strdup(p);
  81     return 0;
  82 }
  83
  84 /*
  85  * file=gluster[+transport]://[server[:port]]/volname/image[?socket=...]
  86  *
  87  * 'gluster' is the protocol.
  88  *
  89  * 'transport' specifies the transport type used to connect to gluster
  90  * management daemon (glusterd). Valid transport types are
  91  * tcp, unix and rdma. If a transport type isn't specified, then tcp
  92  * type is assumed.
  93  *
  94  * 'server' specifies the server where the volume file specification for
  95  * the given volume resides. This can be either hostname, ipv4 address
  96  * or ipv6 address. ipv6 address needs to be within square brackets [ ].
  97  * If transport type is 'unix', then 'server' field should not be specifed.
  98  * The 'socket' field needs to be populated with the path to unix domain
  99  * socket.
 100  *
 101  * 'port' is the port number on which glusterd is listening. This is optional
 102  * and if not specified, QEMU will send 0 which will make gluster to use the
 103  * default port. If the transport type is unix, then 'port' should not be
 104  * specified.
 105  *
 106  * 'volname' is the name of the gluster volume which contains the VM image.
 107  *
 108  * 'image' is the path to the actual VM image that resides on gluster volume.
 109  *
 110  * Examples:
 111  *
 112  * file=gluster://1.2.3.4/testvol/a.img
 113  * file=gluster+tcp://1.2.3.4/testvol/a.img
 114  * file=gluster+tcp://1.2.3.4:24007/testvol/dir/a.img
 115  * file=gluster+tcp://[1:2:3:4:5:6:7:8]/testvol/dir/a.img
 116  * file=gluster+tcp://[1:2:3:4:5:6:7:8]:24007/testvol/dir/a.img
 117  * file=gluster+tcp://server.domain.com:24007/testvol/dir/a.img
 118  * file=gluster+unix:///testvol/dir/a.img?socket=/tmp/glusterd.socket
 119  * file=gluster+rdma://1.2.3.4:24007/testvol/a.img
 120  */
 121 static int qemu_gluster_parseuri(GlusterConf *gconf, const char *filename)
 122 {
 123     URI *uri;
 124     QueryParams *qp = NULL;
 125     bool is_unix = false;
 126     int ret = 0;
 127
 128     uri = uri_parse(filename);
 129     if (!uri) {
 130         return -EINVAL;
 131     }
 132
 133     /* transport */
 134     if (!strcmp(uri->scheme, "gluster")) {
 135         gconf->transport = g_strdup("tcp");
 136     } else if (!strcmp(uri->scheme, "gluster+tcp")) {
 137         gconf->transport = g_strdup("tcp");
 138     } else if (!strcmp(uri->scheme, "gluster+unix")) {
 139         gconf->transport = g_strdup("unix");
 140         is_unix = true;
 141     } else if (!strcmp(uri->scheme, "gluster+rdma")) {
 142         gconf->transport = g_strdup("rdma");
 143     } else {
 144         ret = -EINVAL;
 145         goto out;
 146     }
 147
 148     ret = parse_volume_options(gconf, uri->path);
 149     if (ret < 0) {
 150         goto out;
 151     }
 152
 153     qp = query_params_parse(uri->query);
 154     if (qp->n > 1 || (is_unix && !qp->n) || (!is_unix && qp->n)) {
 155         ret = -EINVAL;
 156         goto out;
 157     }
 158
 159     if (is_unix) {
 160         if (uri->server || uri->port) {
 161             ret = -EINVAL;
 162             goto out;
 163         }
 164         if (strcmp(qp->p[0].name, "socket")) {
 165             ret = -EINVAL;
 166             goto out;
 167         }
 168         gconf->server = g_strdup(qp->p[0].value);
 169     } else {
 170         gconf->server = g_strdup(uri->server);
 171         gconf->port = uri->port;
 172     }
 173
 174 out:
 175     if (qp) {
 176         query_params_free(qp);
 177     }
 178     uri_free(uri);
 179     return ret;
 180 }
 181
 182 static struct glfs *qemu_gluster_init(GlusterConf *gconf, const char *filename)
 183 {
 184     struct glfs *glfs = NULL;
 185     int ret;
 186     int old_errno;
 187
 188     ret = qemu_gluster_parseuri(gconf, filename);
 189     if (ret < 0) {
 190         error_report("Usage: file=gluster[+transport]://[server[:port]]/"
 191             "volname/image[?socket=...]");
 192         errno = -ret;
 193         goto out;
 194     }
 195
 196     glfs = glfs_new(gconf->volname);
 197     if (!glfs) {
 198         goto out;
 199     }
 200
 201     ret = glfs_set_volfile_server(glfs, gconf->transport, gconf->server,
 202             gconf->port);
 203     if (ret < 0) {
 204         goto out;
 205     }
 206
 207     /*
 208      * TODO: Use GF_LOG_ERROR instead of hard code value of 4 here when
 209      * GlusterFS makes GF_LOG_* macros available to libgfapi users.
 210      */
 211     ret = glfs_set_logging(glfs, "-", 4);
 212     if (ret < 0) {
 213         goto out;
 214     }
 215
 216     ret = glfs_init(glfs);
 217     if (ret) {
 218         error_report("Gluster connection failed for server=%s port=%d "
 219              "volume=%s image=%s transport=%s", gconf->server, gconf->port,
 220              gconf->volname, gconf->image, gconf->transport);
 221         goto out;
 222     }
 223     return glfs;
 224
 225 out:
 226     if (glfs) {
 227         old_errno = errno;
 228         glfs_fini(glfs);
 229         errno = old_errno;
 230     }
 231     return NULL;
 232 }
 233
 234 static void qemu_gluster_complete_aio(GlusterAIOCB *acb, BDRVGlusterState *s)
 235 {
 236     int ret;
 237     bool *finished = acb->finished;
 238     BlockDriverCompletionFunc *cb = acb->common.cb;
 239     void *opaque = acb->common.opaque;
 240
 241     if (!acb->ret || acb->ret == acb->size) {
 242         ret = 0; /* Success */
 243     } else if (acb->ret < 0) {
 244         ret = acb->ret; /* Read/Write failed */
 245     } else {
 246         ret = -EIO; /* Partial read/write - fail it */
 247     }
 248
 249     qemu_aio_release(acb);
 250     cb(opaque, ret);
 251     if (finished) {
 252         *finished = true;
 253     }
 254 }
 255
 256 static void qemu_gluster_aio_event_reader(void *opaque)
 257 {
 258     BDRVGlusterState *s = opaque;
 259     ssize_t ret;
 260
 261     do {
 262         char *p = (char *)&s->event_acb;
 263
 264         ret = read(s->fds[GLUSTER_FD_READ], p + s->event_reader_pos,
 265                    sizeof(s->event_acb) - s->event_reader_pos);
 266         if (ret > 0) {
 267             s->event_reader_pos += ret;
 268             if (s->event_reader_pos == sizeof(s->event_acb)) {
 269                 s->event_reader_pos = 0;
 270                 qemu_gluster_complete_aio(s->event_acb, s);
 271             }
 272         }
 273     } while (ret < 0 && errno == EINTR);
 274 }
 275
 276 /* TODO Convert to fine grained options */
 277 static QemuOptsList runtime_opts = {
 278     .name = "gluster",
 279     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
 280     .desc = {
 281         {
 282             .name = "filename",
 283             .type = QEMU_OPT_STRING,
 284             .help = "URL to the gluster image",
 285         },
 286         { /* end of list */ }
 287     },
 288 };
 289
 290 static int qemu_gluster_open(BlockDriverState *bs,  QDict *options,
 291                              int bdrv_flags, Error **errp)
 292 {
 293     BDRVGlusterState *s = bs->opaque;
 294     int open_flags = O_BINARY;
 295     int ret = 0;
 296     GlusterConf *gconf = g_malloc0(sizeof(GlusterConf));
 297     QemuOpts *opts;
 298     Error *local_err = NULL;
 299     const char *filename;
 300
 301     opts = qemu_opts_create_nofail(&runtime_opts);
 302     qemu_opts_absorb_qdict(opts, options, &local_err);
 303     if (error_is_set(&local_err)) {
 304         qerror_report_err(local_err);
 305         error_free(local_err);
 306         ret = -EINVAL;
 307         goto out;
 308     }
 309
 310     filename = qemu_opt_get(opts, "filename");
 311
 312
 313     s->glfs = qemu_gluster_init(gconf, filename);
 314     if (!s->glfs) {
 315         ret = -errno;
 316         goto out;
 317     }
 318
 319     if (bdrv_flags & BDRV_O_RDWR) {
 320         open_flags |= O_RDWR;
 321     } else {
 322         open_flags |= O_RDONLY;
 323     }
 324
 325     if ((bdrv_flags & BDRV_O_NOCACHE)) {
 326         open_flags |= O_DIRECT;
 327     }
 328
 329     s->fd = glfs_open(s->glfs, gconf->image, open_flags);
 330     if (!s->fd) {
 331         ret = -errno;
 332         goto out;
 333     }
 334
 335     ret = qemu_pipe(s->fds);
 336     if (ret < 0) {
 337         ret = -errno;
 338         goto out;
 339     }
 340     fcntl(s->fds[GLUSTER_FD_READ], F_SETFL, O_NONBLOCK);
 341     qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ],
 342         qemu_gluster_aio_event_reader, NULL, s);
 343
 344 out:
 345     qemu_opts_del(opts);
 346     qemu_gluster_gconf_free(gconf);
 347     if (!ret) {
 348         return ret;
 349     }
 350     if (s->fd) {
 351         glfs_close(s->fd);
 352     }
 353     if (s->glfs) {
 354         glfs_fini(s->glfs);
 355     }
 356     return ret;
 357 }
 358
 359 static int qemu_gluster_create(const char *filename,
 360         QEMUOptionParameter *options, Error **errp)
 361 {
 362     struct glfs *glfs;
 363     struct glfs_fd *fd;
 364     int ret = 0;
 365     int64_t total_size = 0;
 366     GlusterConf *gconf = g_malloc0(sizeof(GlusterConf));
 367
 368     glfs = qemu_gluster_init(gconf, filename);
 369     if (!glfs) {
 370         ret = -errno;
 371         goto out;
 372     }
 373
 374     while (options && options->name) {
 375         if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
 376             total_size = options->value.n / BDRV_SECTOR_SIZE;
 377         }
 378         options++;
 379     }
 380
 381     fd = glfs_creat(glfs, gconf->image,
 382         O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR);
 383     if (!fd) {
 384         ret = -errno;
 385     } else {
 386         if (glfs_ftruncate(fd, total_size * BDRV_SECTOR_SIZE) != 0) {
 387             ret = -errno;
 388         }
 389         if (glfs_close(fd) != 0) {
 390             ret = -errno;
 391         }
 392     }
 393 out:
 394     qemu_gluster_gconf_free(gconf);
 395     if (glfs) {
 396         glfs_fini(glfs);
 397     }
 398     return ret;
 399 }
 400
 401 static void qemu_gluster_aio_cancel(BlockDriverAIOCB *blockacb)
 402 {
 403     GlusterAIOCB *acb = (GlusterAIOCB *)blockacb;
 404     bool finished = false;
 405
 406     acb->finished = &finished;
 407     while (!finished) {
 408         qemu_aio_wait();
 409     }
 410 }
 411
 412 static const AIOCBInfo gluster_aiocb_info = {
 413     .aiocb_size = sizeof(GlusterAIOCB),
 414     .cancel = qemu_gluster_aio_cancel,
 415 };
 416
 417 static void gluster_finish_aiocb(struct glfs_fd *fd, ssize_t ret, void *arg)
 418 {
 419     GlusterAIOCB *acb = (GlusterAIOCB *)arg;
 420     BlockDriverState *bs = acb->common.bs;
 421     BDRVGlusterState *s = bs->opaque;
 422     int retval;
 423
 424     acb->ret = ret;
 425     retval = qemu_write_full(s->fds[GLUSTER_FD_WRITE], &acb, sizeof(acb));
 426     if (retval != sizeof(acb)) {
 427         /*
 428          * Gluster AIO callback thread failed to notify the waiting
 429          * QEMU thread about IO completion.
 430          */
 431         error_report("Gluster AIO completion failed: %s", strerror(errno));
 432         abort();
 433     }
 434 }
 435
 436 static BlockDriverAIOCB *qemu_gluster_aio_rw(BlockDriverState *bs,
 437         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 438         BlockDriverCompletionFunc *cb, void *opaque, int write)
 439 {
 440     int ret;
 441     GlusterAIOCB *acb;
 442     BDRVGlusterState *s = bs->opaque;
 443     size_t size;
 444     off_t offset;
 445
 446     offset = sector_num * BDRV_SECTOR_SIZE;
 447     size = nb_sectors * BDRV_SECTOR_SIZE;
 448
 449     acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque);
 450     acb->size = size;
 451     acb->ret = 0;
 452     acb->finished = NULL;
 453
 454     if (write) {
 455         ret = glfs_pwritev_async(s->fd, qiov->iov, qiov->niov, offset, 0,
 456             &gluster_finish_aiocb, acb);
 457     } else {
 458         ret = glfs_preadv_async(s->fd, qiov->iov, qiov->niov, offset, 0,
 459             &gluster_finish_aiocb, acb);
 460     }
 461
 462     if (ret < 0) {
 463         goto out;
 464     }
 465     return &acb->common;
 466
 467 out:
 468     qemu_aio_release(acb);
 469     return NULL;
 470 }
 471
 472 static int qemu_gluster_truncate(BlockDriverState *bs, int64_t offset)
 473 {
 474     int ret;
 475     BDRVGlusterState *s = bs->opaque;
 476
 477     ret = glfs_ftruncate(s->fd, offset);
 478     if (ret < 0) {
 479         return -errno;
 480     }
 481
 482     return 0;
 483 }
 484
 485 static BlockDriverAIOCB *qemu_gluster_aio_readv(BlockDriverState *bs,
 486         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 487         BlockDriverCompletionFunc *cb, void *opaque)
 488 {
 489     return qemu_gluster_aio_rw(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
 490 }
 491
 492 static BlockDriverAIOCB *qemu_gluster_aio_writev(BlockDriverState *bs,
 493         int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
 494         BlockDriverCompletionFunc *cb, void *opaque)
 495 {
 496     return qemu_gluster_aio_rw(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
 497 }
 498
 499 static BlockDriverAIOCB *qemu_gluster_aio_flush(BlockDriverState *bs,
 500         BlockDriverCompletionFunc *cb, void *opaque)
 501 {
 502     int ret;
 503     GlusterAIOCB *acb;
 504     BDRVGlusterState *s = bs->opaque;
 505
 506     acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque);
 507     acb->size = 0;
 508     acb->ret = 0;
 509     acb->finished = NULL;
 510
 511     ret = glfs_fsync_async(s->fd, &gluster_finish_aiocb, acb);
 512     if (ret < 0) {
 513         goto out;
 514     }
 515     return &acb->common;
 516
 517 out:
 518     qemu_aio_release(acb);
 519     return NULL;
 520 }
 521
 522 #ifdef CONFIG_GLUSTERFS_DISCARD
 523 static BlockDriverAIOCB *qemu_gluster_aio_discard(BlockDriverState *bs,
 524         int64_t sector_num, int nb_sectors, BlockDriverCompletionFunc *cb,
 525         void *opaque)
 526 {
 527     int ret;
 528     GlusterAIOCB *acb;
 529     BDRVGlusterState *s = bs->opaque;
 530     size_t size;
 531     off_t offset;
 532
 533     offset = sector_num * BDRV_SECTOR_SIZE;
 534     size = nb_sectors * BDRV_SECTOR_SIZE;
 535
 536     acb = qemu_aio_get(&gluster_aiocb_info, bs, cb, opaque);
 537     acb->size = 0;
 538     acb->ret = 0;
 539     acb->finished = NULL;
 540
 541     ret = glfs_discard_async(s->fd, offset, size, &gluster_finish_aiocb, acb);
 542     if (ret < 0) {
 543         goto out;
 544     }
 545     return &acb->common;
 546
 547 out:
 548     qemu_aio_release(acb);
 549     return NULL;
 550 }
 551 #endif
 552
 553 static int64_t qemu_gluster_getlength(BlockDriverState *bs)
 554 {
 555     BDRVGlusterState *s = bs->opaque;
 556     int64_t ret;
 557
 558     ret = glfs_lseek(s->fd, 0, SEEK_END);
 559     if (ret < 0) {
 560         return -errno;
 561     } else {
 562         return ret;
 563     }
 564 }
 565
 566 static int64_t qemu_gluster_allocated_file_size(BlockDriverState *bs)
 567 {
 568     BDRVGlusterState *s = bs->opaque;
 569     struct stat st;
 570     int ret;
 571
 572     ret = glfs_fstat(s->fd, &st);
 573     if (ret < 0) {
 574         return -errno;
 575     } else {
 576         return st.st_blocks * 512;
 577     }
 578 }
 579
 580 static void qemu_gluster_close(BlockDriverState *bs)
 581 {
 582     BDRVGlusterState *s = bs->opaque;
 583
 584     close(s->fds[GLUSTER_FD_READ]);
 585     close(s->fds[GLUSTER_FD_WRITE]);
 586     qemu_aio_set_fd_handler(s->fds[GLUSTER_FD_READ], NULL, NULL, NULL);
 587
 588     if (s->fd) {
 589         glfs_close(s->fd);
 590         s->fd = NULL;
 591     }
 592     glfs_fini(s->glfs);
 593 }
 594
 595 static int qemu_gluster_has_zero_init(BlockDriverState *bs)
 596 {
 597     /* GlusterFS volume could be backed by a block device */
 598     return 0;
 599 }
 600
 601 static QEMUOptionParameter qemu_gluster_create_options[] = {
 602     {
 603         .name = BLOCK_OPT_SIZE,
 604         .type = OPT_SIZE,
 605         .help = "Virtual disk size"
 606     },
 607     { NULL }
 608 };
 609
 610 static BlockDriver bdrv_gluster = {
 611     .format_name                  = "gluster",
 612     .protocol_name                = "gluster",
 613     .instance_size                = sizeof(BDRVGlusterState),
 614     .bdrv_needs_filename          = true,
 615     .bdrv_file_open               = qemu_gluster_open,
 616     .bdrv_close                   = qemu_gluster_close,
 617     .bdrv_create                  = qemu_gluster_create,
 618     .bdrv_getlength               = qemu_gluster_getlength,
 619     .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
 620     .bdrv_truncate                = qemu_gluster_truncate,
 621     .bdrv_aio_readv               = qemu_gluster_aio_readv,
 622     .bdrv_aio_writev              = qemu_gluster_aio_writev,
 623     .bdrv_aio_flush               = qemu_gluster_aio_flush,
 624     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
 625 #ifdef CONFIG_GLUSTERFS_DISCARD
 626     .bdrv_aio_discard             = qemu_gluster_aio_discard,
 627 #endif
 628     .create_options               = qemu_gluster_create_options,
 629 };
 630
 631 static BlockDriver bdrv_gluster_tcp = {
 632     .format_name                  = "gluster",
 633     .protocol_name                = "gluster+tcp",
 634     .instance_size                = sizeof(BDRVGlusterState),
 635     .bdrv_needs_filename          = true,
 636     .bdrv_file_open               = qemu_gluster_open,
 637     .bdrv_close                   = qemu_gluster_close,
 638     .bdrv_create                  = qemu_gluster_create,
 639     .bdrv_getlength               = qemu_gluster_getlength,
 640     .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
 641     .bdrv_truncate                = qemu_gluster_truncate,
 642     .bdrv_aio_readv               = qemu_gluster_aio_readv,
 643     .bdrv_aio_writev              = qemu_gluster_aio_writev,
 644     .bdrv_aio_flush               = qemu_gluster_aio_flush,
 645     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
 646 #ifdef CONFIG_GLUSTERFS_DISCARD
 647     .bdrv_aio_discard             = qemu_gluster_aio_discard,
 648 #endif
 649     .create_options               = qemu_gluster_create_options,
 650 };
 651
 652 static BlockDriver bdrv_gluster_unix = {
 653     .format_name                  = "gluster",
 654     .protocol_name                = "gluster+unix",
 655     .instance_size                = sizeof(BDRVGlusterState),
 656     .bdrv_needs_filename          = true,
 657     .bdrv_file_open               = qemu_gluster_open,
 658     .bdrv_close                   = qemu_gluster_close,
 659     .bdrv_create                  = qemu_gluster_create,
 660     .bdrv_getlength               = qemu_gluster_getlength,
 661     .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
 662     .bdrv_truncate                = qemu_gluster_truncate,
 663     .bdrv_aio_readv               = qemu_gluster_aio_readv,
 664     .bdrv_aio_writev              = qemu_gluster_aio_writev,
 665     .bdrv_aio_flush               = qemu_gluster_aio_flush,
 666     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
 667 #ifdef CONFIG_GLUSTERFS_DISCARD
 668     .bdrv_aio_discard             = qemu_gluster_aio_discard,
 669 #endif
 670     .create_options               = qemu_gluster_create_options,
 671 };
 672
 673 static BlockDriver bdrv_gluster_rdma = {
 674     .format_name                  = "gluster",
 675     .protocol_name                = "gluster+rdma",
 676     .instance_size                = sizeof(BDRVGlusterState),
 677     .bdrv_needs_filename          = true,
 678     .bdrv_file_open               = qemu_gluster_open,
 679     .bdrv_close                   = qemu_gluster_close,
 680     .bdrv_create                  = qemu_gluster_create,
 681     .bdrv_getlength               = qemu_gluster_getlength,
 682     .bdrv_get_allocated_file_size = qemu_gluster_allocated_file_size,
 683     .bdrv_truncate                = qemu_gluster_truncate,
 684     .bdrv_aio_readv               = qemu_gluster_aio_readv,
 685     .bdrv_aio_writev              = qemu_gluster_aio_writev,
 686     .bdrv_aio_flush               = qemu_gluster_aio_flush,
 687     .bdrv_has_zero_init           = qemu_gluster_has_zero_init,
 688 #ifdef CONFIG_GLUSTERFS_DISCARD
 689     .bdrv_aio_discard             = qemu_gluster_aio_discard,
 690 #endif
 691     .create_options               = qemu_gluster_create_options,
 692 };
 693
 694 static void bdrv_gluster_init(void)
 695 {
 696     bdrv_register(&bdrv_gluster_rdma);
 697     bdrv_register(&bdrv_gluster_unix);
 698     bdrv_register(&bdrv_gluster_tcp);
 699     bdrv_register(&bdrv_gluster);
 700 }
 701
 702 block_init(bdrv_gluster_init);