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 RBD_AIO_FLUSH 68 } RBDAIOCmd; 69 70 typedef struct RBDAIOCB { 71 BlockDriverAIOCB common; 72 QEMUBH *bh; 73 int64_t ret; 74 QEMUIOVector *qiov; 75 char *bounce; 76 RBDAIOCmd cmd; 77 int64_t sector_num; 78 int error; 79 struct BDRVRBDState *s; 80 int cancelled; 81 int status; 82 } RBDAIOCB; 83 84 typedef struct RADOSCB { 85 int rcbid; 86 RBDAIOCB *acb; 87 struct BDRVRBDState *s; 88 int done; 89 int64_t size; 90 char *buf; 91 int64_t ret; 92 } RADOSCB; 93 94 #define RBD_FD_READ 0 95 #define RBD_FD_WRITE 1 96 97 typedef struct BDRVRBDState { 98 rados_t cluster; 99 rados_ioctx_t io_ctx; 100 rbd_image_t image; 101 char name[RBD_MAX_IMAGE_NAME_SIZE]; 102 char *snap; 103 } BDRVRBDState; 104 105 static int qemu_rbd_next_tok(char *dst, int dst_len, 106 char *src, char delim, 107 const char *name, 108 char **p, Error **errp) 109 { 110 int l; 111 char *end; 112 113 *p = NULL; 114 115 if (delim != '\0') { 116 for (end = src; *end; ++end) { 117 if (*end == delim) { 118 break; 119 } 120 if (*end == '\\' && end[1] != '\0') { 121 end++; 122 } 123 } 124 if (*end == delim) { 125 *p = end + 1; 126 *end = '\0'; 127 } 128 } 129 l = strlen(src); 130 if (l >= dst_len) { 131 error_setg(errp, "%s too long", name); 132 return -EINVAL; 133 } else if (l == 0) { 134 error_setg(errp, "%s too short", name); 135 return -EINVAL; 136 } 137 138 pstrcpy(dst, dst_len, src); 139 140 return 0; 141 } 142 143 static void qemu_rbd_unescape(char *src) 144 { 145 char *p; 146 147 for (p = src; *src; ++src, ++p) { 148 if (*src == '\\' && src[1] != '\0') { 149 src++; 150 } 151 *p = *src; 152 } 153 *p = '\0'; 154 } 155 156 static int qemu_rbd_parsename(const char *filename, 157 char *pool, int pool_len, 158 char *snap, int snap_len, 159 char *name, int name_len, 160 char *conf, int conf_len, 161 Error **errp) 162 { 163 const char *start; 164 char *p, *buf; 165 int ret; 166 167 if (!strstart(filename, "rbd:", &start)) { 168 error_setg(errp, "File name must start with 'rbd:'"); 169 return -EINVAL; 170 } 171 172 buf = g_strdup(start); 173 p = buf; 174 *snap = '\0'; 175 *conf = '\0'; 176 177 ret = qemu_rbd_next_tok(pool, pool_len, p, 178 '/', "pool name", &p, errp); 179 if (ret < 0 || !p) { 180 ret = -EINVAL; 181 goto done; 182 } 183 qemu_rbd_unescape(pool); 184 185 if (strchr(p, '@')) { 186 ret = qemu_rbd_next_tok(name, name_len, p, 187 '@', "object name", &p, errp); 188 if (ret < 0) { 189 goto done; 190 } 191 ret = qemu_rbd_next_tok(snap, snap_len, p, 192 ':', "snap name", &p, errp); 193 qemu_rbd_unescape(snap); 194 } else { 195 ret = qemu_rbd_next_tok(name, name_len, p, 196 ':', "object name", &p, errp); 197 } 198 qemu_rbd_unescape(name); 199 if (ret < 0 || !p) { 200 goto done; 201 } 202 203 ret = qemu_rbd_next_tok(conf, conf_len, p, 204 '\0', "configuration", &p, errp); 205 206 done: 207 g_free(buf); 208 return ret; 209 } 210 211 static char *qemu_rbd_parse_clientname(const char *conf, char *clientname) 212 { 213 const char *p = conf; 214 215 while (*p) { 216 int len; 217 const char *end = strchr(p, ':'); 218 219 if (end) { 220 len = end - p; 221 } else { 222 len = strlen(p); 223 } 224 225 if (strncmp(p, "id=", 3) == 0) { 226 len -= 3; 227 strncpy(clientname, p + 3, len); 228 clientname[len] = '\0'; 229 return clientname; 230 } 231 if (end == NULL) { 232 break; 233 } 234 p = end + 1; 235 } 236 return NULL; 237 } 238 239 static int qemu_rbd_set_conf(rados_t cluster, const char *conf, Error **errp) 240 { 241 char *p, *buf; 242 char name[RBD_MAX_CONF_NAME_SIZE]; 243 char value[RBD_MAX_CONF_VAL_SIZE]; 244 int ret = 0; 245 246 buf = g_strdup(conf); 247 p = buf; 248 249 while (p) { 250 ret = qemu_rbd_next_tok(name, sizeof(name), p, 251 '=', "conf option name", &p, errp); 252 if (ret < 0) { 253 break; 254 } 255 qemu_rbd_unescape(name); 256 257 if (!p) { 258 error_setg(errp, "conf option %s has no value", name); 259 ret = -EINVAL; 260 break; 261 } 262 263 ret = qemu_rbd_next_tok(value, sizeof(value), p, 264 ':', "conf option value", &p, errp); 265 if (ret < 0) { 266 break; 267 } 268 qemu_rbd_unescape(value); 269 270 if (strcmp(name, "conf") == 0) { 271 ret = rados_conf_read_file(cluster, value); 272 if (ret < 0) { 273 error_setg(errp, "error reading conf file %s", value); 274 break; 275 } 276 } else if (strcmp(name, "id") == 0) { 277 /* ignore, this is parsed by qemu_rbd_parse_clientname() */ 278 } else { 279 ret = rados_conf_set(cluster, name, value); 280 if (ret < 0) { 281 error_setg(errp, "invalid conf option %s", name); 282 ret = -EINVAL; 283 break; 284 } 285 } 286 } 287 288 g_free(buf); 289 return ret; 290 } 291 292 static int qemu_rbd_create(const char *filename, QEMUOptionParameter *options, 293 Error **errp) 294 { 295 Error *local_err = NULL; 296 int64_t bytes = 0; 297 int64_t objsize; 298 int obj_order = 0; 299 char pool[RBD_MAX_POOL_NAME_SIZE]; 300 char name[RBD_MAX_IMAGE_NAME_SIZE]; 301 char snap_buf[RBD_MAX_SNAP_NAME_SIZE]; 302 char conf[RBD_MAX_CONF_SIZE]; 303 char clientname_buf[RBD_MAX_CONF_SIZE]; 304 char *clientname; 305 rados_t cluster; 306 rados_ioctx_t io_ctx; 307 int ret; 308 309 if (qemu_rbd_parsename(filename, pool, sizeof(pool), 310 snap_buf, sizeof(snap_buf), 311 name, sizeof(name), 312 conf, sizeof(conf), &local_err) < 0) { 313 error_propagate(errp, local_err); 314 return -EINVAL; 315 } 316 317 /* Read out options */ 318 while (options && options->name) { 319 if (!strcmp(options->name, BLOCK_OPT_SIZE)) { 320 bytes = options->value.n; 321 } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { 322 if (options->value.n) { 323 objsize = options->value.n; 324 if ((objsize - 1) & objsize) { /* not a power of 2? */ 325 error_setg(errp, "obj size needs to be power of 2"); 326 return -EINVAL; 327 } 328 if (objsize < 4096) { 329 error_setg(errp, "obj size too small"); 330 return -EINVAL; 331 } 332 obj_order = ffs(objsize) - 1; 333 } 334 } 335 options++; 336 } 337 338 clientname = qemu_rbd_parse_clientname(conf, clientname_buf); 339 if (rados_create(&cluster, clientname) < 0) { 340 error_setg(errp, "error initializing"); 341 return -EIO; 342 } 343 344 if (strstr(conf, "conf=") == NULL) { 345 /* try default location, but ignore failure */ 346 rados_conf_read_file(cluster, NULL); 347 } 348 349 if (conf[0] != '\0' && 350 qemu_rbd_set_conf(cluster, conf, &local_err) < 0) { 351 rados_shutdown(cluster); 352 error_propagate(errp, local_err); 353 return -EIO; 354 } 355 356 if (rados_connect(cluster) < 0) { 357 error_setg(errp, "error connecting"); 358 rados_shutdown(cluster); 359 return -EIO; 360 } 361 362 if (rados_ioctx_create(cluster, pool, &io_ctx) < 0) { 363 error_setg(errp, "error opening pool %s", pool); 364 rados_shutdown(cluster); 365 return -EIO; 366 } 367 368 ret = rbd_create(io_ctx, name, bytes, &obj_order); 369 rados_ioctx_destroy(io_ctx); 370 rados_shutdown(cluster); 371 372 return ret; 373 } 374 375 /* 376 * This aio completion is being called from rbd_finish_bh() and runs in qemu 377 * BH context. 378 */ 379 static void qemu_rbd_complete_aio(RADOSCB *rcb) 380 { 381 RBDAIOCB *acb = rcb->acb; 382 int64_t r; 383 384 r = rcb->ret; 385 386 if (acb->cmd != RBD_AIO_READ) { 387 if (r < 0) { 388 acb->ret = r; 389 acb->error = 1; 390 } else if (!acb->error) { 391 acb->ret = rcb->size; 392 } 393 } else { 394 if (r < 0) { 395 memset(rcb->buf, 0, rcb->size); 396 acb->ret = r; 397 acb->error = 1; 398 } else if (r < rcb->size) { 399 memset(rcb->buf + r, 0, rcb->size - r); 400 if (!acb->error) { 401 acb->ret = rcb->size; 402 } 403 } else if (!acb->error) { 404 acb->ret = r; 405 } 406 } 407 408 g_free(rcb); 409 410 if (acb->cmd == RBD_AIO_READ) { 411 qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); 412 } 413 qemu_vfree(acb->bounce); 414 acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret)); 415 acb->status = 0; 416 417 if (!acb->cancelled) { 418 qemu_aio_release(acb); 419 } 420 } 421 422 /* TODO Convert to fine grained options */ 423 static QemuOptsList runtime_opts = { 424 .name = "rbd", 425 .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), 426 .desc = { 427 { 428 .name = "filename", 429 .type = QEMU_OPT_STRING, 430 .help = "Specification of the rbd image", 431 }, 432 { /* end of list */ } 433 }, 434 }; 435 436 static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags, 437 Error **errp) 438 { 439 BDRVRBDState *s = bs->opaque; 440 char pool[RBD_MAX_POOL_NAME_SIZE]; 441 char snap_buf[RBD_MAX_SNAP_NAME_SIZE]; 442 char conf[RBD_MAX_CONF_SIZE]; 443 char clientname_buf[RBD_MAX_CONF_SIZE]; 444 char *clientname; 445 QemuOpts *opts; 446 Error *local_err = NULL; 447 const char *filename; 448 int r; 449 450 opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); 451 qemu_opts_absorb_qdict(opts, options, &local_err); 452 if (local_err) { 453 error_propagate(errp, local_err); 454 qemu_opts_del(opts); 455 return -EINVAL; 456 } 457 458 filename = qemu_opt_get(opts, "filename"); 459 460 if (qemu_rbd_parsename(filename, pool, sizeof(pool), 461 snap_buf, sizeof(snap_buf), 462 s->name, sizeof(s->name), 463 conf, sizeof(conf), errp) < 0) { 464 r = -EINVAL; 465 goto failed_opts; 466 } 467 468 clientname = qemu_rbd_parse_clientname(conf, clientname_buf); 469 r = rados_create(&s->cluster, clientname); 470 if (r < 0) { 471 error_setg(&local_err, "error initializing"); 472 goto failed_opts; 473 } 474 475 s->snap = NULL; 476 if (snap_buf[0] != '\0') { 477 s->snap = g_strdup(snap_buf); 478 } 479 480 /* 481 * Fallback to more conservative semantics if setting cache 482 * options fails. Ignore errors from setting rbd_cache because the 483 * only possible error is that the option does not exist, and 484 * librbd defaults to no caching. If write through caching cannot 485 * be set up, fall back to no caching. 486 */ 487 if (flags & BDRV_O_NOCACHE) { 488 rados_conf_set(s->cluster, "rbd_cache", "false"); 489 } else { 490 rados_conf_set(s->cluster, "rbd_cache", "true"); 491 } 492 493 if (strstr(conf, "conf=") == NULL) { 494 /* try default location, but ignore failure */ 495 rados_conf_read_file(s->cluster, NULL); 496 } 497 498 if (conf[0] != '\0') { 499 r = qemu_rbd_set_conf(s->cluster, conf, errp); 500 if (r < 0) { 501 goto failed_shutdown; 502 } 503 } 504 505 r = rados_connect(s->cluster); 506 if (r < 0) { 507 error_setg(&local_err, "error connecting"); 508 goto failed_shutdown; 509 } 510 511 r = rados_ioctx_create(s->cluster, pool, &s->io_ctx); 512 if (r < 0) { 513 error_setg(&local_err, "error opening pool %s", pool); 514 goto failed_shutdown; 515 } 516 517 r = rbd_open(s->io_ctx, s->name, &s->image, s->snap); 518 if (r < 0) { 519 error_setg(&local_err, "error reading header from %s", s->name); 520 goto failed_open; 521 } 522 523 bs->read_only = (s->snap != NULL); 524 525 qemu_opts_del(opts); 526 return 0; 527 528 failed_open: 529 rados_ioctx_destroy(s->io_ctx); 530 failed_shutdown: 531 rados_shutdown(s->cluster); 532 g_free(s->snap); 533 failed_opts: 534 qemu_opts_del(opts); 535 return r; 536 } 537 538 static void qemu_rbd_close(BlockDriverState *bs) 539 { 540 BDRVRBDState *s = bs->opaque; 541 542 rbd_close(s->image); 543 rados_ioctx_destroy(s->io_ctx); 544 g_free(s->snap); 545 rados_shutdown(s->cluster); 546 } 547 548 /* 549 * Cancel aio. Since we don't reference acb in a non qemu threads, 550 * it is safe to access it here. 551 */ 552 static void qemu_rbd_aio_cancel(BlockDriverAIOCB *blockacb) 553 { 554 RBDAIOCB *acb = (RBDAIOCB *) blockacb; 555 acb->cancelled = 1; 556 557 while (acb->status == -EINPROGRESS) { 558 aio_poll(bdrv_get_aio_context(acb->common.bs), true); 559 } 560 561 qemu_aio_release(acb); 562 } 563 564 static const AIOCBInfo rbd_aiocb_info = { 565 .aiocb_size = sizeof(RBDAIOCB), 566 .cancel = qemu_rbd_aio_cancel, 567 }; 568 569 static void rbd_finish_bh(void *opaque) 570 { 571 RADOSCB *rcb = opaque; 572 qemu_bh_delete(rcb->acb->bh); 573 qemu_rbd_complete_aio(rcb); 574 } 575 576 /* 577 * This is the callback function for rbd_aio_read and _write 578 * 579 * Note: this function is being called from a non qemu thread so 580 * we need to be careful about what we do here. Generally we only 581 * schedule a BH, and do the rest of the io completion handling 582 * from rbd_finish_bh() which runs in a qemu context. 583 */ 584 static void rbd_finish_aiocb(rbd_completion_t c, RADOSCB *rcb) 585 { 586 RBDAIOCB *acb = rcb->acb; 587 588 rcb->ret = rbd_aio_get_return_value(c); 589 rbd_aio_release(c); 590 591 acb->bh = aio_bh_new(bdrv_get_aio_context(acb->common.bs), 592 rbd_finish_bh, rcb); 593 qemu_bh_schedule(acb->bh); 594 } 595 596 static int rbd_aio_discard_wrapper(rbd_image_t image, 597 uint64_t off, 598 uint64_t len, 599 rbd_completion_t comp) 600 { 601 #ifdef LIBRBD_SUPPORTS_DISCARD 602 return rbd_aio_discard(image, off, len, comp); 603 #else 604 return -ENOTSUP; 605 #endif 606 } 607 608 static int rbd_aio_flush_wrapper(rbd_image_t image, 609 rbd_completion_t comp) 610 { 611 #ifdef LIBRBD_SUPPORTS_AIO_FLUSH 612 return rbd_aio_flush(image, comp); 613 #else 614 return -ENOTSUP; 615 #endif 616 } 617 618 static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs, 619 int64_t sector_num, 620 QEMUIOVector *qiov, 621 int nb_sectors, 622 BlockDriverCompletionFunc *cb, 623 void *opaque, 624 RBDAIOCmd cmd) 625 { 626 RBDAIOCB *acb; 627 RADOSCB *rcb; 628 rbd_completion_t c; 629 int64_t off, size; 630 char *buf; 631 int r; 632 633 BDRVRBDState *s = bs->opaque; 634 635 acb = qemu_aio_get(&rbd_aiocb_info, bs, cb, opaque); 636 acb->cmd = cmd; 637 acb->qiov = qiov; 638 if (cmd == RBD_AIO_DISCARD || cmd == RBD_AIO_FLUSH) { 639 acb->bounce = NULL; 640 } else { 641 acb->bounce = qemu_blockalign(bs, qiov->size); 642 } 643 acb->ret = 0; 644 acb->error = 0; 645 acb->s = s; 646 acb->cancelled = 0; 647 acb->bh = NULL; 648 acb->status = -EINPROGRESS; 649 650 if (cmd == RBD_AIO_WRITE) { 651 qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); 652 } 653 654 buf = acb->bounce; 655 656 off = sector_num * BDRV_SECTOR_SIZE; 657 size = nb_sectors * BDRV_SECTOR_SIZE; 658 659 rcb = g_malloc(sizeof(RADOSCB)); 660 rcb->done = 0; 661 rcb->acb = acb; 662 rcb->buf = buf; 663 rcb->s = acb->s; 664 rcb->size = size; 665 r = rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, &c); 666 if (r < 0) { 667 goto failed; 668 } 669 670 switch (cmd) { 671 case RBD_AIO_WRITE: 672 r = rbd_aio_write(s->image, off, size, buf, c); 673 break; 674 case RBD_AIO_READ: 675 r = rbd_aio_read(s->image, off, size, buf, c); 676 break; 677 case RBD_AIO_DISCARD: 678 r = rbd_aio_discard_wrapper(s->image, off, size, c); 679 break; 680 case RBD_AIO_FLUSH: 681 r = rbd_aio_flush_wrapper(s->image, c); 682 break; 683 default: 684 r = -EINVAL; 685 } 686 687 if (r < 0) { 688 goto failed_completion; 689 } 690 691 return &acb->common; 692 693 failed_completion: 694 rbd_aio_release(c); 695 failed: 696 g_free(rcb); 697 qemu_vfree(acb->bounce); 698 qemu_aio_release(acb); 699 return NULL; 700 } 701 702 static BlockDriverAIOCB *qemu_rbd_aio_readv(BlockDriverState *bs, 703 int64_t sector_num, 704 QEMUIOVector *qiov, 705 int nb_sectors, 706 BlockDriverCompletionFunc *cb, 707 void *opaque) 708 { 709 return rbd_start_aio(bs, sector_num, qiov, nb_sectors, cb, opaque, 710 RBD_AIO_READ); 711 } 712 713 static BlockDriverAIOCB *qemu_rbd_aio_writev(BlockDriverState *bs, 714 int64_t sector_num, 715 QEMUIOVector *qiov, 716 int nb_sectors, 717 BlockDriverCompletionFunc *cb, 718 void *opaque) 719 { 720 return rbd_start_aio(bs, sector_num, qiov, nb_sectors, cb, opaque, 721 RBD_AIO_WRITE); 722 } 723 724 #ifdef LIBRBD_SUPPORTS_AIO_FLUSH 725 static BlockDriverAIOCB *qemu_rbd_aio_flush(BlockDriverState *bs, 726 BlockDriverCompletionFunc *cb, 727 void *opaque) 728 { 729 return rbd_start_aio(bs, 0, NULL, 0, cb, opaque, RBD_AIO_FLUSH); 730 } 731 732 #else 733 734 static int qemu_rbd_co_flush(BlockDriverState *bs) 735 { 736 #if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(0, 1, 1) 737 /* rbd_flush added in 0.1.1 */ 738 BDRVRBDState *s = bs->opaque; 739 return rbd_flush(s->image); 740 #else 741 return 0; 742 #endif 743 } 744 #endif 745 746 static int qemu_rbd_getinfo(BlockDriverState *bs, BlockDriverInfo *bdi) 747 { 748 BDRVRBDState *s = bs->opaque; 749 rbd_image_info_t info; 750 int r; 751 752 r = rbd_stat(s->image, &info, sizeof(info)); 753 if (r < 0) { 754 return r; 755 } 756 757 bdi->cluster_size = info.obj_size; 758 return 0; 759 } 760 761 static int64_t qemu_rbd_getlength(BlockDriverState *bs) 762 { 763 BDRVRBDState *s = bs->opaque; 764 rbd_image_info_t info; 765 int r; 766 767 r = rbd_stat(s->image, &info, sizeof(info)); 768 if (r < 0) { 769 return r; 770 } 771 772 return info.size; 773 } 774 775 static int qemu_rbd_truncate(BlockDriverState *bs, int64_t offset) 776 { 777 BDRVRBDState *s = bs->opaque; 778 int r; 779 780 r = rbd_resize(s->image, offset); 781 if (r < 0) { 782 return r; 783 } 784 785 return 0; 786 } 787 788 static int qemu_rbd_snap_create(BlockDriverState *bs, 789 QEMUSnapshotInfo *sn_info) 790 { 791 BDRVRBDState *s = bs->opaque; 792 int r; 793 794 if (sn_info->name[0] == '\0') { 795 return -EINVAL; /* we need a name for rbd snapshots */ 796 } 797 798 /* 799 * rbd snapshots are using the name as the user controlled unique identifier 800 * we can't use the rbd snapid for that purpose, as it can't be set 801 */ 802 if (sn_info->id_str[0] != '\0' && 803 strcmp(sn_info->id_str, sn_info->name) != 0) { 804 return -EINVAL; 805 } 806 807 if (strlen(sn_info->name) >= sizeof(sn_info->id_str)) { 808 return -ERANGE; 809 } 810 811 r = rbd_snap_create(s->image, sn_info->name); 812 if (r < 0) { 813 error_report("failed to create snap: %s", strerror(-r)); 814 return r; 815 } 816 817 return 0; 818 } 819 820 static int qemu_rbd_snap_remove(BlockDriverState *bs, 821 const char *snapshot_id, 822 const char *snapshot_name, 823 Error **errp) 824 { 825 BDRVRBDState *s = bs->opaque; 826 int r; 827 828 if (!snapshot_name) { 829 error_setg(errp, "rbd need a valid snapshot name"); 830 return -EINVAL; 831 } 832 833 /* If snapshot_id is specified, it must be equal to name, see 834 qemu_rbd_snap_list() */ 835 if (snapshot_id && strcmp(snapshot_id, snapshot_name)) { 836 error_setg(errp, 837 "rbd do not support snapshot id, it should be NULL or " 838 "equal to snapshot name"); 839 return -EINVAL; 840 } 841 842 r = rbd_snap_remove(s->image, snapshot_name); 843 if (r < 0) { 844 error_setg_errno(errp, -r, "Failed to remove the snapshot"); 845 } 846 return r; 847 } 848 849 static int qemu_rbd_snap_rollback(BlockDriverState *bs, 850 const char *snapshot_name) 851 { 852 BDRVRBDState *s = bs->opaque; 853 int r; 854 855 r = rbd_snap_rollback(s->image, snapshot_name); 856 return r; 857 } 858 859 static int qemu_rbd_snap_list(BlockDriverState *bs, 860 QEMUSnapshotInfo **psn_tab) 861 { 862 BDRVRBDState *s = bs->opaque; 863 QEMUSnapshotInfo *sn_info, *sn_tab = NULL; 864 int i, snap_count; 865 rbd_snap_info_t *snaps; 866 int max_snaps = RBD_MAX_SNAPS; 867 868 do { 869 snaps = g_malloc(sizeof(*snaps) * max_snaps); 870 snap_count = rbd_snap_list(s->image, snaps, &max_snaps); 871 if (snap_count <= 0) { 872 g_free(snaps); 873 } 874 } while (snap_count == -ERANGE); 875 876 if (snap_count <= 0) { 877 goto done; 878 } 879 880 sn_tab = g_malloc0(snap_count * sizeof(QEMUSnapshotInfo)); 881 882 for (i = 0; i < snap_count; i++) { 883 const char *snap_name = snaps[i].name; 884 885 sn_info = sn_tab + i; 886 pstrcpy(sn_info->id_str, sizeof(sn_info->id_str), snap_name); 887 pstrcpy(sn_info->name, sizeof(sn_info->name), snap_name); 888 889 sn_info->vm_state_size = snaps[i].size; 890 sn_info->date_sec = 0; 891 sn_info->date_nsec = 0; 892 sn_info->vm_clock_nsec = 0; 893 } 894 rbd_snap_list_end(snaps); 895 g_free(snaps); 896 897 done: 898 *psn_tab = sn_tab; 899 return snap_count; 900 } 901 902 #ifdef LIBRBD_SUPPORTS_DISCARD 903 static BlockDriverAIOCB* qemu_rbd_aio_discard(BlockDriverState *bs, 904 int64_t sector_num, 905 int nb_sectors, 906 BlockDriverCompletionFunc *cb, 907 void *opaque) 908 { 909 return rbd_start_aio(bs, sector_num, NULL, nb_sectors, cb, opaque, 910 RBD_AIO_DISCARD); 911 } 912 #endif 913 914 static QEMUOptionParameter qemu_rbd_create_options[] = { 915 { 916 .name = BLOCK_OPT_SIZE, 917 .type = OPT_SIZE, 918 .help = "Virtual disk size" 919 }, 920 { 921 .name = BLOCK_OPT_CLUSTER_SIZE, 922 .type = OPT_SIZE, 923 .help = "RBD object size" 924 }, 925 {NULL} 926 }; 927 928 static BlockDriver bdrv_rbd = { 929 .format_name = "rbd", 930 .instance_size = sizeof(BDRVRBDState), 931 .bdrv_needs_filename = true, 932 .bdrv_file_open = qemu_rbd_open, 933 .bdrv_close = qemu_rbd_close, 934 .bdrv_create = qemu_rbd_create, 935 .bdrv_has_zero_init = bdrv_has_zero_init_1, 936 .bdrv_get_info = qemu_rbd_getinfo, 937 .create_options = qemu_rbd_create_options, 938 .bdrv_getlength = qemu_rbd_getlength, 939 .bdrv_truncate = qemu_rbd_truncate, 940 .protocol_name = "rbd", 941 942 .bdrv_aio_readv = qemu_rbd_aio_readv, 943 .bdrv_aio_writev = qemu_rbd_aio_writev, 944 945 #ifdef LIBRBD_SUPPORTS_AIO_FLUSH 946 .bdrv_aio_flush = qemu_rbd_aio_flush, 947 #else 948 .bdrv_co_flush_to_disk = qemu_rbd_co_flush, 949 #endif 950 951 #ifdef LIBRBD_SUPPORTS_DISCARD 952 .bdrv_aio_discard = qemu_rbd_aio_discard, 953 #endif 954 955 .bdrv_snapshot_create = qemu_rbd_snap_create, 956 .bdrv_snapshot_delete = qemu_rbd_snap_remove, 957 .bdrv_snapshot_list = qemu_rbd_snap_list, 958 .bdrv_snapshot_goto = qemu_rbd_snap_rollback, 959 }; 960 961 static void bdrv_rbd_init(void) 962 { 963 bdrv_register(&bdrv_rbd); 964 } 965 966 block_init(bdrv_rbd_init); 967