1 /* 2 * QEMU Block driver for RADOS (Ceph) 3 * 4 * Copyright (C) 2010-2011 Christian Brunner <chb@muc.de>, 5 * Josh Durgin <josh.durgin@dreamhost.com> 6 * 7 * This work is licensed under the terms of the GNU GPL, version 2. See 8 * the COPYING file in the top-level directory. 9 * 10 * Contributions after 2012-01-13 are licensed under the terms of the 11 * GNU GPL, version 2 or (at your option) any later version. 12 */ 13 14 #include <inttypes.h> 15 16 #include "qemu-common.h" 17 #include "qemu/error-report.h" 18 #include "block/block_int.h" 19 20 #include <rbd/librbd.h> 21 22 /* 23 * When specifying the image filename use: 24 * 25 * rbd:poolname/devicename[@snapshotname][:option1=value1[:option2=value2...]] 26 * 27 * poolname must be the name of an existing rados pool. 28 * 29 * devicename is the name of the rbd image. 30 * 31 * Each option given is used to configure rados, and may be any valid 32 * Ceph option, "id", or "conf". 33 * 34 * The "id" option indicates what user we should authenticate as to 35 * the Ceph cluster. If it is excluded we will use the Ceph default 36 * (normally 'admin'). 37 * 38 * The "conf" option specifies a Ceph configuration file to read. If 39 * it is not specified, we will read from the default Ceph locations 40 * (e.g., /etc/ceph/ceph.conf). To avoid reading _any_ configuration 41 * file, specify conf=/dev/null. 42 * 43 * Configuration values containing :, @, or = can be escaped with a 44 * leading "\". 45 */ 46 47 /* rbd_aio_discard added in 0.1.2 */ 48 #if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(0, 1, 2) 49 #define LIBRBD_SUPPORTS_DISCARD 50 #else 51 #undef LIBRBD_SUPPORTS_DISCARD 52 #endif 53 54 #define OBJ_MAX_SIZE (1UL << OBJ_DEFAULT_OBJ_ORDER) 55 56 #define RBD_MAX_CONF_NAME_SIZE 128 57 #define RBD_MAX_CONF_VAL_SIZE 512 58 #define RBD_MAX_CONF_SIZE 1024 59 #define RBD_MAX_POOL_NAME_SIZE 128 60 #define RBD_MAX_SNAP_NAME_SIZE 128 61 #define RBD_MAX_SNAPS 100 62 63 typedef enum { 64 RBD_AIO_READ, 65 RBD_AIO_WRITE, 66 RBD_AIO_DISCARD 67 } RBDAIOCmd; 68 69 typedef struct RBDAIOCB { 70 BlockDriverAIOCB common; 71 QEMUBH *bh; 72 int64_t ret; 73 QEMUIOVector *qiov; 74 char *bounce; 75 RBDAIOCmd cmd; 76 int64_t sector_num; 77 int error; 78 struct BDRVRBDState *s; 79 int cancelled; 80 int status; 81 } RBDAIOCB; 82 83 typedef struct RADOSCB { 84 int rcbid; 85 RBDAIOCB *acb; 86 struct BDRVRBDState *s; 87 int done; 88 int64_t size; 89 char *buf; 90 int64_t ret; 91 } RADOSCB; 92 93 #define RBD_FD_READ 0 94 #define RBD_FD_WRITE 1 95 96 typedef struct BDRVRBDState { 97 int fds[2]; 98 rados_t cluster; 99 rados_ioctx_t io_ctx; 100 rbd_image_t image; 101 char name[RBD_MAX_IMAGE_NAME_SIZE]; 102 int qemu_aio_count; 103 char *snap; 104 int event_reader_pos; 105 RADOSCB *event_rcb; 106 } BDRVRBDState; 107 108 static void rbd_aio_bh_cb(void *opaque); 109 110 static int qemu_rbd_next_tok(char *dst, int dst_len, 111 char *src, char delim, 112 const char *name, 113 char **p) 114 { 115 int l; 116 char *end; 117 118 *p = NULL; 119 120 if (delim != '\0') { 121 for (end = src; *end; ++end) { 122 if (*end == delim) { 123 break; 124 } 125 if (*end == '\\' && end[1] != '\0') { 126 end++; 127 } 128 } 129 if (*end == delim) { 130 *p = end + 1; 131 *end = '\0'; 132 } 133 } 134 l = strlen(src); 135 if (l >= dst_len) { 136 error_report("%s too long", name); 137 return -EINVAL; 138 } else if (l == 0) { 139 error_report("%s too short", name); 140 return -EINVAL; 141 } 142 143 pstrcpy(dst, dst_len, src); 144 145 return 0; 146 } 147 148 static void qemu_rbd_unescape(char *src) 149 { 150 char *p; 151 152 for (p = src; *src; ++src, ++p) { 153 if (*src == '\\' && src[1] != '\0') { 154 src++; 155 } 156 *p = *src; 157 } 158 *p = '\0'; 159 } 160 161 static int qemu_rbd_parsename(const char *filename, 162 char *pool, int pool_len, 163 char *snap, int snap_len, 164 char *name, int name_len, 165 char *conf, int conf_len) 166 { 167 const char *start; 168 char *p, *buf; 169 int ret; 170 171 if (!strstart(filename, "rbd:", &start)) { 172 return -EINVAL; 173 } 174 175 buf = g_strdup(start); 176 p = buf; 177 *snap = '\0'; 178 *conf = '\0'; 179 180 ret = qemu_rbd_next_tok(pool, pool_len, p, '/', "pool name", &p); 181 if (ret < 0 || !p) { 182 ret = -EINVAL; 183 goto done; 184 } 185 qemu_rbd_unescape(pool); 186 187 if (strchr(p, '@')) { 188 ret = qemu_rbd_next_tok(name, name_len, p, '@', "object name", &p); 189 if (ret < 0) { 190 goto done; 191 } 192 ret = qemu_rbd_next_tok(snap, snap_len, p, ':', "snap name", &p); 193 qemu_rbd_unescape(snap); 194 } else { 195 ret = qemu_rbd_next_tok(name, name_len, p, ':', "object name", &p); 196 } 197 qemu_rbd_unescape(name); 198 if (ret < 0 || !p) { 199 goto done; 200 } 201 202 ret = qemu_rbd_next_tok(conf, conf_len, p, '\0', "configuration", &p); 203 204 done: 205 g_free(buf); 206 return ret; 207 } 208 209 static char *qemu_rbd_parse_clientname(const char *conf, char *clientname) 210 { 211 const char *p = conf; 212 213 while (*p) { 214 int len; 215 const char *end = strchr(p, ':'); 216 217 if (end) { 218 len = end - p; 219 } else { 220 len = strlen(p); 221 } 222 223 if (strncmp(p, "id=", 3) == 0) { 224 len -= 3; 225 strncpy(clientname, p + 3, len); 226 clientname[len] = '\0'; 227 return clientname; 228 } 229 if (end == NULL) { 230 break; 231 } 232 p = end + 1; 233 } 234 return NULL; 235 } 236 237 static int qemu_rbd_set_conf(rados_t cluster, const char *conf) 238 { 239 char *p, *buf; 240 char name[RBD_MAX_CONF_NAME_SIZE]; 241 char value[RBD_MAX_CONF_VAL_SIZE]; 242 int ret = 0; 243 244 buf = g_strdup(conf); 245 p = buf; 246 247 while (p) { 248 ret = qemu_rbd_next_tok(name, sizeof(name), p, 249 '=', "conf option name", &p); 250 if (ret < 0) { 251 break; 252 } 253 qemu_rbd_unescape(name); 254 255 if (!p) { 256 error_report("conf option %s has no value", name); 257 ret = -EINVAL; 258 break; 259 } 260 261 ret = qemu_rbd_next_tok(value, sizeof(value), p, 262 ':', "conf option value", &p); 263 if (ret < 0) { 264 break; 265 } 266 qemu_rbd_unescape(value); 267 268 if (strcmp(name, "conf") == 0) { 269 ret = rados_conf_read_file(cluster, value); 270 if (ret < 0) { 271 error_report("error reading conf file %s", value); 272 break; 273 } 274 } else if (strcmp(name, "id") == 0) { 275 /* ignore, this is parsed by qemu_rbd_parse_clientname() */ 276 } else { 277 ret = rados_conf_set(cluster, name, value); 278 if (ret < 0) { 279 error_report("invalid conf option %s", name); 280 ret = -EINVAL; 281 break; 282 } 283 } 284 } 285 286 g_free(buf); 287 return ret; 288 } 289 290 static int qemu_rbd_create(const char *filename, QEMUOptionParameter *options) 291 { 292 int64_t bytes = 0; 293 int64_t objsize; 294 int obj_order = 0; 295 char pool[RBD_MAX_POOL_NAME_SIZE]; 296 char name[RBD_MAX_IMAGE_NAME_SIZE]; 297 char snap_buf[RBD_MAX_SNAP_NAME_SIZE]; 298 char conf[RBD_MAX_CONF_SIZE]; 299 char clientname_buf[RBD_MAX_CONF_SIZE]; 300 char *clientname; 301 rados_t cluster; 302 rados_ioctx_t io_ctx; 303 int ret; 304 305 if (qemu_rbd_parsename(filename, pool, sizeof(pool), 306 snap_buf, sizeof(snap_buf), 307 name, sizeof(name), 308 conf, sizeof(conf)) < 0) { 309 return -EINVAL; 310 } 311 312 /* Read out options */ 313 while (options && options->name) { 314 if (!strcmp(options->name, BLOCK_OPT_SIZE)) { 315 bytes = options->value.n; 316 } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { 317 if (options->value.n) { 318 objsize = options->value.n; 319 if ((objsize - 1) & objsize) { /* not a power of 2? */ 320 error_report("obj size needs to be power of 2"); 321 return -EINVAL; 322 } 323 if (objsize < 4096) { 324 error_report("obj size too small"); 325 return -EINVAL; 326 } 327 obj_order = ffs(objsize) - 1; 328 } 329 } 330 options++; 331 } 332 333 clientname = qemu_rbd_parse_clientname(conf, clientname_buf); 334 if (rados_create(&cluster, clientname) < 0) { 335 error_report("error initializing"); 336 return -EIO; 337 } 338 339 if (strstr(conf, "conf=") == NULL) { 340 /* try default location, but ignore failure */ 341 rados_conf_read_file(cluster, NULL); 342 } 343 344 if (conf[0] != '\0' && 345 qemu_rbd_set_conf(cluster, conf) < 0) { 346 error_report("error setting config options"); 347 rados_shutdown(cluster); 348 return -EIO; 349 } 350 351 if (rados_connect(cluster) < 0) { 352 error_report("error connecting"); 353 rados_shutdown(cluster); 354 return -EIO; 355 } 356 357 if (rados_ioctx_create(cluster, pool, &io_ctx) < 0) { 358 error_report("error opening pool %s", pool); 359 rados_shutdown(cluster); 360 return -EIO; 361 } 362 363 ret = rbd_create(io_ctx, name, bytes, &obj_order); 364 rados_ioctx_destroy(io_ctx); 365 rados_shutdown(cluster); 366 367 return ret; 368 } 369 370 /* 371 * This aio completion is being called from qemu_rbd_aio_event_reader() 372 * and runs in qemu context. It schedules a bh, but just in case the aio 373 * was not cancelled before. 374 */ 375 static void qemu_rbd_complete_aio(RADOSCB *rcb) 376 { 377 RBDAIOCB *acb = rcb->acb; 378 int64_t r; 379 380 r = rcb->ret; 381 382 if (acb->cmd == RBD_AIO_WRITE || 383 acb->cmd == RBD_AIO_DISCARD) { 384 if (r < 0) { 385 acb->ret = r; 386 acb->error = 1; 387 } else if (!acb->error) { 388 acb->ret = rcb->size; 389 } 390 } else { 391 if (r < 0) { 392 memset(rcb->buf, 0, rcb->size); 393 acb->ret = r; 394 acb->error = 1; 395 } else if (r < rcb->size) { 396 memset(rcb->buf + r, 0, rcb->size - r); 397 if (!acb->error) { 398 acb->ret = rcb->size; 399 } 400 } else if (!acb->error) { 401 acb->ret = r; 402 } 403 } 404 /* Note that acb->bh can be NULL in case where the aio was cancelled */ 405 acb->bh = qemu_bh_new(rbd_aio_bh_cb, acb); 406 qemu_bh_schedule(acb->bh); 407 g_free(rcb); 408 } 409 410 /* 411 * aio fd read handler. It runs in the qemu context and calls the 412 * completion handling of completed rados aio operations. 413 */ 414 static void qemu_rbd_aio_event_reader(void *opaque) 415 { 416 BDRVRBDState *s = opaque; 417 418 ssize_t ret; 419 420 do { 421 char *p = (char *)&s->event_rcb; 422 423 /* now read the rcb pointer that was sent from a non qemu thread */ 424 ret = read(s->fds[RBD_FD_READ], p + s->event_reader_pos, 425 sizeof(s->event_rcb) - s->event_reader_pos); 426 if (ret > 0) { 427 s->event_reader_pos += ret; 428 if (s->event_reader_pos == sizeof(s->event_rcb)) { 429 s->event_reader_pos = 0; 430 qemu_rbd_complete_aio(s->event_rcb); 431 s->qemu_aio_count--; 432 } 433 } 434 } while (ret < 0 && errno == EINTR); 435 } 436 437 static int qemu_rbd_aio_flush_cb(void *opaque) 438 { 439 BDRVRBDState *s = opaque; 440 441 return (s->qemu_aio_count > 0); 442 } 443 444 static int qemu_rbd_open(BlockDriverState *bs, const char *filename, 445 QDict *options, int flags) 446 { 447 BDRVRBDState *s = bs->opaque; 448 char pool[RBD_MAX_POOL_NAME_SIZE]; 449 char snap_buf[RBD_MAX_SNAP_NAME_SIZE]; 450 char conf[RBD_MAX_CONF_SIZE]; 451 char clientname_buf[RBD_MAX_CONF_SIZE]; 452 char *clientname; 453 int r; 454 455 if (qemu_rbd_parsename(filename, pool, sizeof(pool), 456 snap_buf, sizeof(snap_buf), 457 s->name, sizeof(s->name), 458 conf, sizeof(conf)) < 0) { 459 return -EINVAL; 460 } 461 462 clientname = qemu_rbd_parse_clientname(conf, clientname_buf); 463 r = rados_create(&s->cluster, clientname); 464 if (r < 0) { 465 error_report("error initializing"); 466 return r; 467 } 468 469 s->snap = NULL; 470 if (snap_buf[0] != '\0') { 471 s->snap = g_strdup(snap_buf); 472 } 473 474 /* 475 * Fallback to more conservative semantics if setting cache 476 * options fails. Ignore errors from setting rbd_cache because the 477 * only possible error is that the option does not exist, and 478 * librbd defaults to no caching. If write through caching cannot 479 * be set up, fall back to no caching. 480 */ 481 if (flags & BDRV_O_NOCACHE) { 482 rados_conf_set(s->cluster, "rbd_cache", "false"); 483 } else { 484 rados_conf_set(s->cluster, "rbd_cache", "true"); 485 } 486 487 if (strstr(conf, "conf=") == NULL) { 488 /* try default location, but ignore failure */ 489 rados_conf_read_file(s->cluster, NULL); 490 } 491 492 if (conf[0] != '\0') { 493 r = qemu_rbd_set_conf(s->cluster, conf); 494 if (r < 0) { 495 error_report("error setting config options"); 496 goto failed_shutdown; 497 } 498 } 499 500 r = rados_connect(s->cluster); 501 if (r < 0) { 502 error_report("error connecting"); 503 goto failed_shutdown; 504 } 505 506 r = rados_ioctx_create(s->cluster, pool, &s->io_ctx); 507 if (r < 0) { 508 error_report("error opening pool %s", pool); 509 goto failed_shutdown; 510 } 511 512 r = rbd_open(s->io_ctx, s->name, &s->image, s->snap); 513 if (r < 0) { 514 error_report("error reading header from %s", s->name); 515 goto failed_open; 516 } 517 518 bs->read_only = (s->snap != NULL); 519 520 s->event_reader_pos = 0; 521 r = qemu_pipe(s->fds); 522 if (r < 0) { 523 error_report("error opening eventfd"); 524 goto failed; 525 } 526 fcntl(s->fds[0], F_SETFL, O_NONBLOCK); 527 fcntl(s->fds[1], F_SETFL, O_NONBLOCK); 528 qemu_aio_set_fd_handler(s->fds[RBD_FD_READ], qemu_rbd_aio_event_reader, 529 NULL, qemu_rbd_aio_flush_cb, s); 530 531 532 return 0; 533 534 failed: 535 rbd_close(s->image); 536 failed_open: 537 rados_ioctx_destroy(s->io_ctx); 538 failed_shutdown: 539 rados_shutdown(s->cluster); 540 g_free(s->snap); 541 return r; 542 } 543 544 static void qemu_rbd_close(BlockDriverState *bs) 545 { 546 BDRVRBDState *s = bs->opaque; 547 548 close(s->fds[0]); 549 close(s->fds[1]); 550 qemu_aio_set_fd_handler(s->fds[RBD_FD_READ], NULL, NULL, NULL, NULL); 551 552 rbd_close(s->image); 553 rados_ioctx_destroy(s->io_ctx); 554 g_free(s->snap); 555 rados_shutdown(s->cluster); 556 } 557 558 /* 559 * Cancel aio. Since we don't reference acb in a non qemu threads, 560 * it is safe to access it here. 561 */ 562 static void qemu_rbd_aio_cancel(BlockDriverAIOCB *blockacb) 563 { 564 RBDAIOCB *acb = (RBDAIOCB *) blockacb; 565 acb->cancelled = 1; 566 567 while (acb->status == -EINPROGRESS) { 568 qemu_aio_wait(); 569 } 570 571 qemu_aio_release(acb); 572 } 573 574 static const AIOCBInfo rbd_aiocb_info = { 575 .aiocb_size = sizeof(RBDAIOCB), 576 .cancel = qemu_rbd_aio_cancel, 577 }; 578 579 static int qemu_rbd_send_pipe(BDRVRBDState *s, RADOSCB *rcb) 580 { 581 int ret = 0; 582 while (1) { 583 fd_set wfd; 584 int fd = s->fds[RBD_FD_WRITE]; 585 586 /* send the op pointer to the qemu thread that is responsible 587 for the aio/op completion. Must do it in a qemu thread context */ 588 ret = write(fd, (void *)&rcb, sizeof(rcb)); 589 if (ret >= 0) { 590 break; 591 } 592 if (errno == EINTR) { 593 continue; 594 } 595 if (errno != EAGAIN) { 596 break; 597 } 598 599 FD_ZERO(&wfd); 600 FD_SET(fd, &wfd); 601 do { 602 ret = select(fd + 1, NULL, &wfd, NULL, NULL); 603 } while (ret < 0 && errno == EINTR); 604 } 605 606 return ret; 607 } 608 609 /* 610 * This is the callback function for rbd_aio_read and _write 611 * 612 * Note: this function is being called from a non qemu thread so 613 * we need to be careful about what we do here. Generally we only 614 * write to the block notification pipe, and do the rest of the 615 * io completion handling from qemu_rbd_aio_event_reader() which 616 * runs in a qemu context. 617 */ 618 static void rbd_finish_aiocb(rbd_completion_t c, RADOSCB *rcb) 619 { 620 int ret; 621 rcb->ret = rbd_aio_get_return_value(c); 622 rbd_aio_release(c); 623 ret = qemu_rbd_send_pipe(rcb->s, rcb); 624 if (ret < 0) { 625 error_report("failed writing to acb->s->fds"); 626 g_free(rcb); 627 } 628 } 629 630 /* Callback when all queued rbd_aio requests are complete */ 631 632 static void rbd_aio_bh_cb(void *opaque) 633 { 634 RBDAIOCB *acb = opaque; 635 636 if (acb->cmd == RBD_AIO_READ) { 637 qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); 638 } 639 qemu_vfree(acb->bounce); 640 acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret)); 641 qemu_bh_delete(acb->bh); 642 acb->bh = NULL; 643 acb->status = 0; 644 645 if (!acb->cancelled) { 646 qemu_aio_release(acb); 647 } 648 } 649 650 static int rbd_aio_discard_wrapper(rbd_image_t image, 651 uint64_t off, 652 uint64_t len, 653 rbd_completion_t comp) 654 { 655 #ifdef LIBRBD_SUPPORTS_DISCARD 656 return rbd_aio_discard(image, off, len, comp); 657 #else 658 return -ENOTSUP; 659 #endif 660 } 661 662 static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs, 663 int64_t sector_num, 664 QEMUIOVector *qiov, 665 int nb_sectors, 666 BlockDriverCompletionFunc *cb, 667 void *opaque, 668 RBDAIOCmd cmd) 669 { 670 RBDAIOCB *acb; 671 RADOSCB *rcb; 672 rbd_completion_t c; 673 int64_t off, size; 674 char *buf; 675 int r; 676 677 BDRVRBDState *s = bs->opaque; 678 679 acb = qemu_aio_get(&rbd_aiocb_info, bs, cb, opaque); 680 acb->cmd = cmd; 681 acb->qiov = qiov; 682 if (cmd == RBD_AIO_DISCARD) { 683 acb->bounce = NULL; 684 } else { 685 acb->bounce = qemu_blockalign(bs, qiov->size); 686 } 687 acb->ret = 0; 688 acb->error = 0; 689 acb->s = s; 690 acb->cancelled = 0; 691 acb->bh = NULL; 692 acb->status = -EINPROGRESS; 693 694 if (cmd == RBD_AIO_WRITE) { 695 qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); 696 } 697 698 buf = acb->bounce; 699 700 off = sector_num * BDRV_SECTOR_SIZE; 701 size = nb_sectors * BDRV_SECTOR_SIZE; 702 703 s->qemu_aio_count++; /* All the RADOSCB */ 704 705 rcb = g_malloc(sizeof(RADOSCB)); 706 rcb->done = 0; 707 rcb->acb = acb; 708 rcb->buf = buf; 709 rcb->s = acb->s; 710 rcb->size = size; 711 r = rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, &c); 712 if (r < 0) { 713 goto failed; 714 } 715 716 switch (cmd) { 717 case RBD_AIO_WRITE: 718 r = rbd_aio_write(s->image, off, size, buf, c); 719 break; 720 case RBD_AIO_READ: 721 r = rbd_aio_read(s->image, off, size, buf, c); 722 break; 723 case RBD_AIO_DISCARD: 724 r = rbd_aio_discard_wrapper(s->image, off, size, c); 725 break; 726 default: 727 r = -EINVAL; 728 } 729 730 if (r < 0) { 731 goto failed; 732 } 733 734 return &acb->common; 735 736 failed: 737 g_free(rcb); 738 s->qemu_aio_count--; 739 qemu_aio_release(acb); 740 return NULL; 741 } 742 743 static BlockDriverAIOCB *qemu_rbd_aio_readv(BlockDriverState *bs, 744 int64_t sector_num, 745 QEMUIOVector *qiov, 746 int nb_sectors, 747 BlockDriverCompletionFunc *cb, 748 void *opaque) 749 { 750 return rbd_start_aio(bs, sector_num, qiov, nb_sectors, cb, opaque, 751 RBD_AIO_READ); 752 } 753 754 static BlockDriverAIOCB *qemu_rbd_aio_writev(BlockDriverState *bs, 755 int64_t sector_num, 756 QEMUIOVector *qiov, 757 int nb_sectors, 758 BlockDriverCompletionFunc *cb, 759 void *opaque) 760 { 761 return rbd_start_aio(bs, sector_num, qiov, nb_sectors, cb, opaque, 762 RBD_AIO_WRITE); 763 } 764 765 static int qemu_rbd_co_flush(BlockDriverState *bs) 766 { 767 #if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(0, 1, 1) 768 /* rbd_flush added in 0.1.1 */ 769 BDRVRBDState *s = bs->opaque; 770 return rbd_flush(s->image); 771 #else 772 return 0; 773 #endif 774 } 775 776 static int qemu_rbd_getinfo(BlockDriverState *bs, BlockDriverInfo *bdi) 777 { 778 BDRVRBDState *s = bs->opaque; 779 rbd_image_info_t info; 780 int r; 781 782 r = rbd_stat(s->image, &info, sizeof(info)); 783 if (r < 0) { 784 return r; 785 } 786 787 bdi->cluster_size = info.obj_size; 788 return 0; 789 } 790 791 static int64_t qemu_rbd_getlength(BlockDriverState *bs) 792 { 793 BDRVRBDState *s = bs->opaque; 794 rbd_image_info_t info; 795 int r; 796 797 r = rbd_stat(s->image, &info, sizeof(info)); 798 if (r < 0) { 799 return r; 800 } 801 802 return info.size; 803 } 804 805 static int qemu_rbd_truncate(BlockDriverState *bs, int64_t offset) 806 { 807 BDRVRBDState *s = bs->opaque; 808 int r; 809 810 r = rbd_resize(s->image, offset); 811 if (r < 0) { 812 return r; 813 } 814 815 return 0; 816 } 817 818 static int qemu_rbd_snap_create(BlockDriverState *bs, 819 QEMUSnapshotInfo *sn_info) 820 { 821 BDRVRBDState *s = bs->opaque; 822 int r; 823 824 if (sn_info->name[0] == '\0') { 825 return -EINVAL; /* we need a name for rbd snapshots */ 826 } 827 828 /* 829 * rbd snapshots are using the name as the user controlled unique identifier 830 * we can't use the rbd snapid for that purpose, as it can't be set 831 */ 832 if (sn_info->id_str[0] != '\0' && 833 strcmp(sn_info->id_str, sn_info->name) != 0) { 834 return -EINVAL; 835 } 836 837 if (strlen(sn_info->name) >= sizeof(sn_info->id_str)) { 838 return -ERANGE; 839 } 840 841 r = rbd_snap_create(s->image, sn_info->name); 842 if (r < 0) { 843 error_report("failed to create snap: %s", strerror(-r)); 844 return r; 845 } 846 847 return 0; 848 } 849 850 static int qemu_rbd_snap_remove(BlockDriverState *bs, 851 const char *snapshot_name) 852 { 853 BDRVRBDState *s = bs->opaque; 854 int r; 855 856 r = rbd_snap_remove(s->image, snapshot_name); 857 return r; 858 } 859 860 static int qemu_rbd_snap_rollback(BlockDriverState *bs, 861 const char *snapshot_name) 862 { 863 BDRVRBDState *s = bs->opaque; 864 int r; 865 866 r = rbd_snap_rollback(s->image, snapshot_name); 867 return r; 868 } 869 870 static int qemu_rbd_snap_list(BlockDriverState *bs, 871 QEMUSnapshotInfo **psn_tab) 872 { 873 BDRVRBDState *s = bs->opaque; 874 QEMUSnapshotInfo *sn_info, *sn_tab = NULL; 875 int i, snap_count; 876 rbd_snap_info_t *snaps; 877 int max_snaps = RBD_MAX_SNAPS; 878 879 do { 880 snaps = g_malloc(sizeof(*snaps) * max_snaps); 881 snap_count = rbd_snap_list(s->image, snaps, &max_snaps); 882 if (snap_count < 0) { 883 g_free(snaps); 884 } 885 } while (snap_count == -ERANGE); 886 887 if (snap_count <= 0) { 888 goto done; 889 } 890 891 sn_tab = g_malloc0(snap_count * sizeof(QEMUSnapshotInfo)); 892 893 for (i = 0; i < snap_count; i++) { 894 const char *snap_name = snaps[i].name; 895 896 sn_info = sn_tab + i; 897 pstrcpy(sn_info->id_str, sizeof(sn_info->id_str), snap_name); 898 pstrcpy(sn_info->name, sizeof(sn_info->name), snap_name); 899 900 sn_info->vm_state_size = snaps[i].size; 901 sn_info->date_sec = 0; 902 sn_info->date_nsec = 0; 903 sn_info->vm_clock_nsec = 0; 904 } 905 rbd_snap_list_end(snaps); 906 907 done: 908 *psn_tab = sn_tab; 909 return snap_count; 910 } 911 912 #ifdef LIBRBD_SUPPORTS_DISCARD 913 static BlockDriverAIOCB* qemu_rbd_aio_discard(BlockDriverState *bs, 914 int64_t sector_num, 915 int nb_sectors, 916 BlockDriverCompletionFunc *cb, 917 void *opaque) 918 { 919 return rbd_start_aio(bs, sector_num, NULL, nb_sectors, cb, opaque, 920 RBD_AIO_DISCARD); 921 } 922 #endif 923 924 static QEMUOptionParameter qemu_rbd_create_options[] = { 925 { 926 .name = BLOCK_OPT_SIZE, 927 .type = OPT_SIZE, 928 .help = "Virtual disk size" 929 }, 930 { 931 .name = BLOCK_OPT_CLUSTER_SIZE, 932 .type = OPT_SIZE, 933 .help = "RBD object size" 934 }, 935 {NULL} 936 }; 937 938 static BlockDriver bdrv_rbd = { 939 .format_name = "rbd", 940 .instance_size = sizeof(BDRVRBDState), 941 .bdrv_file_open = qemu_rbd_open, 942 .bdrv_close = qemu_rbd_close, 943 .bdrv_create = qemu_rbd_create, 944 .bdrv_get_info = qemu_rbd_getinfo, 945 .create_options = qemu_rbd_create_options, 946 .bdrv_getlength = qemu_rbd_getlength, 947 .bdrv_truncate = qemu_rbd_truncate, 948 .protocol_name = "rbd", 949 950 .bdrv_aio_readv = qemu_rbd_aio_readv, 951 .bdrv_aio_writev = qemu_rbd_aio_writev, 952 .bdrv_co_flush_to_disk = qemu_rbd_co_flush, 953 954 #ifdef LIBRBD_SUPPORTS_DISCARD 955 .bdrv_aio_discard = qemu_rbd_aio_discard, 956 #endif 957 958 .bdrv_snapshot_create = qemu_rbd_snap_create, 959 .bdrv_snapshot_delete = qemu_rbd_snap_remove, 960 .bdrv_snapshot_list = qemu_rbd_snap_list, 961 .bdrv_snapshot_goto = qemu_rbd_snap_rollback, 962 }; 963 964 static void bdrv_rbd_init(void) 965 { 966 bdrv_register(&bdrv_rbd); 967 } 968 969 block_init(bdrv_rbd_init); 970