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, QemuOpts *opts, Error **errp) 293 { 294 Error *local_err = NULL; 295 int64_t bytes = 0; 296 int64_t objsize; 297 int obj_order = 0; 298 char pool[RBD_MAX_POOL_NAME_SIZE]; 299 char name[RBD_MAX_IMAGE_NAME_SIZE]; 300 char snap_buf[RBD_MAX_SNAP_NAME_SIZE]; 301 char conf[RBD_MAX_CONF_SIZE]; 302 char clientname_buf[RBD_MAX_CONF_SIZE]; 303 char *clientname; 304 rados_t cluster; 305 rados_ioctx_t io_ctx; 306 int ret; 307 308 if (qemu_rbd_parsename(filename, pool, sizeof(pool), 309 snap_buf, sizeof(snap_buf), 310 name, sizeof(name), 311 conf, sizeof(conf), &local_err) < 0) { 312 error_propagate(errp, local_err); 313 return -EINVAL; 314 } 315 316 /* Read out options */ 317 bytes = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); 318 objsize = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, 0); 319 if (objsize) { 320 if ((objsize - 1) & objsize) { /* not a power of 2? */ 321 error_setg(errp, "obj size needs to be power of 2"); 322 return -EINVAL; 323 } 324 if (objsize < 4096) { 325 error_setg(errp, "obj size too small"); 326 return -EINVAL; 327 } 328 obj_order = ffs(objsize) - 1; 329 } 330 331 clientname = qemu_rbd_parse_clientname(conf, clientname_buf); 332 if (rados_create(&cluster, clientname) < 0) { 333 error_setg(errp, "error initializing"); 334 return -EIO; 335 } 336 337 if (strstr(conf, "conf=") == NULL) { 338 /* try default location, but ignore failure */ 339 rados_conf_read_file(cluster, NULL); 340 } 341 342 if (conf[0] != '\0' && 343 qemu_rbd_set_conf(cluster, conf, &local_err) < 0) { 344 rados_shutdown(cluster); 345 error_propagate(errp, local_err); 346 return -EIO; 347 } 348 349 if (rados_connect(cluster) < 0) { 350 error_setg(errp, "error connecting"); 351 rados_shutdown(cluster); 352 return -EIO; 353 } 354 355 if (rados_ioctx_create(cluster, pool, &io_ctx) < 0) { 356 error_setg(errp, "error opening pool %s", pool); 357 rados_shutdown(cluster); 358 return -EIO; 359 } 360 361 ret = rbd_create(io_ctx, name, bytes, &obj_order); 362 rados_ioctx_destroy(io_ctx); 363 rados_shutdown(cluster); 364 365 return ret; 366 } 367 368 /* 369 * This aio completion is being called from rbd_finish_bh() and runs in qemu 370 * BH context. 371 */ 372 static void qemu_rbd_complete_aio(RADOSCB *rcb) 373 { 374 RBDAIOCB *acb = rcb->acb; 375 int64_t r; 376 377 r = rcb->ret; 378 379 if (acb->cmd != RBD_AIO_READ) { 380 if (r < 0) { 381 acb->ret = r; 382 acb->error = 1; 383 } else if (!acb->error) { 384 acb->ret = rcb->size; 385 } 386 } else { 387 if (r < 0) { 388 memset(rcb->buf, 0, rcb->size); 389 acb->ret = r; 390 acb->error = 1; 391 } else if (r < rcb->size) { 392 memset(rcb->buf + r, 0, rcb->size - r); 393 if (!acb->error) { 394 acb->ret = rcb->size; 395 } 396 } else if (!acb->error) { 397 acb->ret = r; 398 } 399 } 400 401 g_free(rcb); 402 403 if (acb->cmd == RBD_AIO_READ) { 404 qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); 405 } 406 qemu_vfree(acb->bounce); 407 acb->common.cb(acb->common.opaque, (acb->ret > 0 ? 0 : acb->ret)); 408 acb->status = 0; 409 410 if (!acb->cancelled) { 411 qemu_aio_release(acb); 412 } 413 } 414 415 /* TODO Convert to fine grained options */ 416 static QemuOptsList runtime_opts = { 417 .name = "rbd", 418 .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), 419 .desc = { 420 { 421 .name = "filename", 422 .type = QEMU_OPT_STRING, 423 .help = "Specification of the rbd image", 424 }, 425 { /* end of list */ } 426 }, 427 }; 428 429 static int qemu_rbd_open(BlockDriverState *bs, QDict *options, int flags, 430 Error **errp) 431 { 432 BDRVRBDState *s = bs->opaque; 433 char pool[RBD_MAX_POOL_NAME_SIZE]; 434 char snap_buf[RBD_MAX_SNAP_NAME_SIZE]; 435 char conf[RBD_MAX_CONF_SIZE]; 436 char clientname_buf[RBD_MAX_CONF_SIZE]; 437 char *clientname; 438 QemuOpts *opts; 439 Error *local_err = NULL; 440 const char *filename; 441 int r; 442 443 opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); 444 qemu_opts_absorb_qdict(opts, options, &local_err); 445 if (local_err) { 446 error_propagate(errp, local_err); 447 qemu_opts_del(opts); 448 return -EINVAL; 449 } 450 451 filename = qemu_opt_get(opts, "filename"); 452 453 if (qemu_rbd_parsename(filename, pool, sizeof(pool), 454 snap_buf, sizeof(snap_buf), 455 s->name, sizeof(s->name), 456 conf, sizeof(conf), errp) < 0) { 457 r = -EINVAL; 458 goto failed_opts; 459 } 460 461 clientname = qemu_rbd_parse_clientname(conf, clientname_buf); 462 r = rados_create(&s->cluster, clientname); 463 if (r < 0) { 464 error_setg(&local_err, "error initializing"); 465 goto failed_opts; 466 } 467 468 s->snap = NULL; 469 if (snap_buf[0] != '\0') { 470 s->snap = g_strdup(snap_buf); 471 } 472 473 /* 474 * Fallback to more conservative semantics if setting cache 475 * options fails. Ignore errors from setting rbd_cache because the 476 * only possible error is that the option does not exist, and 477 * librbd defaults to no caching. If write through caching cannot 478 * be set up, fall back to no caching. 479 */ 480 if (flags & BDRV_O_NOCACHE) { 481 rados_conf_set(s->cluster, "rbd_cache", "false"); 482 } else { 483 rados_conf_set(s->cluster, "rbd_cache", "true"); 484 } 485 486 if (strstr(conf, "conf=") == NULL) { 487 /* try default location, but ignore failure */ 488 rados_conf_read_file(s->cluster, NULL); 489 } 490 491 if (conf[0] != '\0') { 492 r = qemu_rbd_set_conf(s->cluster, conf, errp); 493 if (r < 0) { 494 goto failed_shutdown; 495 } 496 } 497 498 r = rados_connect(s->cluster); 499 if (r < 0) { 500 error_setg(&local_err, "error connecting"); 501 goto failed_shutdown; 502 } 503 504 r = rados_ioctx_create(s->cluster, pool, &s->io_ctx); 505 if (r < 0) { 506 error_setg(&local_err, "error opening pool %s", pool); 507 goto failed_shutdown; 508 } 509 510 r = rbd_open(s->io_ctx, s->name, &s->image, s->snap); 511 if (r < 0) { 512 error_setg(&local_err, "error reading header from %s", s->name); 513 goto failed_open; 514 } 515 516 bs->read_only = (s->snap != NULL); 517 518 qemu_opts_del(opts); 519 return 0; 520 521 failed_open: 522 rados_ioctx_destroy(s->io_ctx); 523 failed_shutdown: 524 rados_shutdown(s->cluster); 525 g_free(s->snap); 526 failed_opts: 527 qemu_opts_del(opts); 528 return r; 529 } 530 531 static void qemu_rbd_close(BlockDriverState *bs) 532 { 533 BDRVRBDState *s = bs->opaque; 534 535 rbd_close(s->image); 536 rados_ioctx_destroy(s->io_ctx); 537 g_free(s->snap); 538 rados_shutdown(s->cluster); 539 } 540 541 /* 542 * Cancel aio. Since we don't reference acb in a non qemu threads, 543 * it is safe to access it here. 544 */ 545 static void qemu_rbd_aio_cancel(BlockDriverAIOCB *blockacb) 546 { 547 RBDAIOCB *acb = (RBDAIOCB *) blockacb; 548 acb->cancelled = 1; 549 550 while (acb->status == -EINPROGRESS) { 551 aio_poll(bdrv_get_aio_context(acb->common.bs), true); 552 } 553 554 qemu_aio_release(acb); 555 } 556 557 static const AIOCBInfo rbd_aiocb_info = { 558 .aiocb_size = sizeof(RBDAIOCB), 559 .cancel = qemu_rbd_aio_cancel, 560 }; 561 562 static void rbd_finish_bh(void *opaque) 563 { 564 RADOSCB *rcb = opaque; 565 qemu_bh_delete(rcb->acb->bh); 566 qemu_rbd_complete_aio(rcb); 567 } 568 569 /* 570 * This is the callback function for rbd_aio_read and _write 571 * 572 * Note: this function is being called from a non qemu thread so 573 * we need to be careful about what we do here. Generally we only 574 * schedule a BH, and do the rest of the io completion handling 575 * from rbd_finish_bh() which runs in a qemu context. 576 */ 577 static void rbd_finish_aiocb(rbd_completion_t c, RADOSCB *rcb) 578 { 579 RBDAIOCB *acb = rcb->acb; 580 581 rcb->ret = rbd_aio_get_return_value(c); 582 rbd_aio_release(c); 583 584 acb->bh = aio_bh_new(bdrv_get_aio_context(acb->common.bs), 585 rbd_finish_bh, rcb); 586 qemu_bh_schedule(acb->bh); 587 } 588 589 static int rbd_aio_discard_wrapper(rbd_image_t image, 590 uint64_t off, 591 uint64_t len, 592 rbd_completion_t comp) 593 { 594 #ifdef LIBRBD_SUPPORTS_DISCARD 595 return rbd_aio_discard(image, off, len, comp); 596 #else 597 return -ENOTSUP; 598 #endif 599 } 600 601 static int rbd_aio_flush_wrapper(rbd_image_t image, 602 rbd_completion_t comp) 603 { 604 #ifdef LIBRBD_SUPPORTS_AIO_FLUSH 605 return rbd_aio_flush(image, comp); 606 #else 607 return -ENOTSUP; 608 #endif 609 } 610 611 static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs, 612 int64_t sector_num, 613 QEMUIOVector *qiov, 614 int nb_sectors, 615 BlockDriverCompletionFunc *cb, 616 void *opaque, 617 RBDAIOCmd cmd) 618 { 619 RBDAIOCB *acb; 620 RADOSCB *rcb; 621 rbd_completion_t c; 622 int64_t off, size; 623 char *buf; 624 int r; 625 626 BDRVRBDState *s = bs->opaque; 627 628 acb = qemu_aio_get(&rbd_aiocb_info, bs, cb, opaque); 629 acb->cmd = cmd; 630 acb->qiov = qiov; 631 if (cmd == RBD_AIO_DISCARD || cmd == RBD_AIO_FLUSH) { 632 acb->bounce = NULL; 633 } else { 634 acb->bounce = qemu_blockalign(bs, qiov->size); 635 } 636 acb->ret = 0; 637 acb->error = 0; 638 acb->s = s; 639 acb->cancelled = 0; 640 acb->bh = NULL; 641 acb->status = -EINPROGRESS; 642 643 if (cmd == RBD_AIO_WRITE) { 644 qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); 645 } 646 647 buf = acb->bounce; 648 649 off = sector_num * BDRV_SECTOR_SIZE; 650 size = nb_sectors * BDRV_SECTOR_SIZE; 651 652 rcb = g_malloc(sizeof(RADOSCB)); 653 rcb->done = 0; 654 rcb->acb = acb; 655 rcb->buf = buf; 656 rcb->s = acb->s; 657 rcb->size = size; 658 r = rbd_aio_create_completion(rcb, (rbd_callback_t) rbd_finish_aiocb, &c); 659 if (r < 0) { 660 goto failed; 661 } 662 663 switch (cmd) { 664 case RBD_AIO_WRITE: 665 r = rbd_aio_write(s->image, off, size, buf, c); 666 break; 667 case RBD_AIO_READ: 668 r = rbd_aio_read(s->image, off, size, buf, c); 669 break; 670 case RBD_AIO_DISCARD: 671 r = rbd_aio_discard_wrapper(s->image, off, size, c); 672 break; 673 case RBD_AIO_FLUSH: 674 r = rbd_aio_flush_wrapper(s->image, c); 675 break; 676 default: 677 r = -EINVAL; 678 } 679 680 if (r < 0) { 681 goto failed_completion; 682 } 683 684 return &acb->common; 685 686 failed_completion: 687 rbd_aio_release(c); 688 failed: 689 g_free(rcb); 690 qemu_vfree(acb->bounce); 691 qemu_aio_release(acb); 692 return NULL; 693 } 694 695 static BlockDriverAIOCB *qemu_rbd_aio_readv(BlockDriverState *bs, 696 int64_t sector_num, 697 QEMUIOVector *qiov, 698 int nb_sectors, 699 BlockDriverCompletionFunc *cb, 700 void *opaque) 701 { 702 return rbd_start_aio(bs, sector_num, qiov, nb_sectors, cb, opaque, 703 RBD_AIO_READ); 704 } 705 706 static BlockDriverAIOCB *qemu_rbd_aio_writev(BlockDriverState *bs, 707 int64_t sector_num, 708 QEMUIOVector *qiov, 709 int nb_sectors, 710 BlockDriverCompletionFunc *cb, 711 void *opaque) 712 { 713 return rbd_start_aio(bs, sector_num, qiov, nb_sectors, cb, opaque, 714 RBD_AIO_WRITE); 715 } 716 717 #ifdef LIBRBD_SUPPORTS_AIO_FLUSH 718 static BlockDriverAIOCB *qemu_rbd_aio_flush(BlockDriverState *bs, 719 BlockDriverCompletionFunc *cb, 720 void *opaque) 721 { 722 return rbd_start_aio(bs, 0, NULL, 0, cb, opaque, RBD_AIO_FLUSH); 723 } 724 725 #else 726 727 static int qemu_rbd_co_flush(BlockDriverState *bs) 728 { 729 #if LIBRBD_VERSION_CODE >= LIBRBD_VERSION(0, 1, 1) 730 /* rbd_flush added in 0.1.1 */ 731 BDRVRBDState *s = bs->opaque; 732 return rbd_flush(s->image); 733 #else 734 return 0; 735 #endif 736 } 737 #endif 738 739 static int qemu_rbd_getinfo(BlockDriverState *bs, BlockDriverInfo *bdi) 740 { 741 BDRVRBDState *s = bs->opaque; 742 rbd_image_info_t info; 743 int r; 744 745 r = rbd_stat(s->image, &info, sizeof(info)); 746 if (r < 0) { 747 return r; 748 } 749 750 bdi->cluster_size = info.obj_size; 751 return 0; 752 } 753 754 static int64_t qemu_rbd_getlength(BlockDriverState *bs) 755 { 756 BDRVRBDState *s = bs->opaque; 757 rbd_image_info_t info; 758 int r; 759 760 r = rbd_stat(s->image, &info, sizeof(info)); 761 if (r < 0) { 762 return r; 763 } 764 765 return info.size; 766 } 767 768 static int qemu_rbd_truncate(BlockDriverState *bs, int64_t offset) 769 { 770 BDRVRBDState *s = bs->opaque; 771 int r; 772 773 r = rbd_resize(s->image, offset); 774 if (r < 0) { 775 return r; 776 } 777 778 return 0; 779 } 780 781 static int qemu_rbd_snap_create(BlockDriverState *bs, 782 QEMUSnapshotInfo *sn_info) 783 { 784 BDRVRBDState *s = bs->opaque; 785 int r; 786 787 if (sn_info->name[0] == '\0') { 788 return -EINVAL; /* we need a name for rbd snapshots */ 789 } 790 791 /* 792 * rbd snapshots are using the name as the user controlled unique identifier 793 * we can't use the rbd snapid for that purpose, as it can't be set 794 */ 795 if (sn_info->id_str[0] != '\0' && 796 strcmp(sn_info->id_str, sn_info->name) != 0) { 797 return -EINVAL; 798 } 799 800 if (strlen(sn_info->name) >= sizeof(sn_info->id_str)) { 801 return -ERANGE; 802 } 803 804 r = rbd_snap_create(s->image, sn_info->name); 805 if (r < 0) { 806 error_report("failed to create snap: %s", strerror(-r)); 807 return r; 808 } 809 810 return 0; 811 } 812 813 static int qemu_rbd_snap_remove(BlockDriverState *bs, 814 const char *snapshot_id, 815 const char *snapshot_name, 816 Error **errp) 817 { 818 BDRVRBDState *s = bs->opaque; 819 int r; 820 821 if (!snapshot_name) { 822 error_setg(errp, "rbd need a valid snapshot name"); 823 return -EINVAL; 824 } 825 826 /* If snapshot_id is specified, it must be equal to name, see 827 qemu_rbd_snap_list() */ 828 if (snapshot_id && strcmp(snapshot_id, snapshot_name)) { 829 error_setg(errp, 830 "rbd do not support snapshot id, it should be NULL or " 831 "equal to snapshot name"); 832 return -EINVAL; 833 } 834 835 r = rbd_snap_remove(s->image, snapshot_name); 836 if (r < 0) { 837 error_setg_errno(errp, -r, "Failed to remove the snapshot"); 838 } 839 return r; 840 } 841 842 static int qemu_rbd_snap_rollback(BlockDriverState *bs, 843 const char *snapshot_name) 844 { 845 BDRVRBDState *s = bs->opaque; 846 int r; 847 848 r = rbd_snap_rollback(s->image, snapshot_name); 849 return r; 850 } 851 852 static int qemu_rbd_snap_list(BlockDriverState *bs, 853 QEMUSnapshotInfo **psn_tab) 854 { 855 BDRVRBDState *s = bs->opaque; 856 QEMUSnapshotInfo *sn_info, *sn_tab = NULL; 857 int i, snap_count; 858 rbd_snap_info_t *snaps; 859 int max_snaps = RBD_MAX_SNAPS; 860 861 do { 862 snaps = g_malloc(sizeof(*snaps) * max_snaps); 863 snap_count = rbd_snap_list(s->image, snaps, &max_snaps); 864 if (snap_count <= 0) { 865 g_free(snaps); 866 } 867 } while (snap_count == -ERANGE); 868 869 if (snap_count <= 0) { 870 goto done; 871 } 872 873 sn_tab = g_malloc0(snap_count * sizeof(QEMUSnapshotInfo)); 874 875 for (i = 0; i < snap_count; i++) { 876 const char *snap_name = snaps[i].name; 877 878 sn_info = sn_tab + i; 879 pstrcpy(sn_info->id_str, sizeof(sn_info->id_str), snap_name); 880 pstrcpy(sn_info->name, sizeof(sn_info->name), snap_name); 881 882 sn_info->vm_state_size = snaps[i].size; 883 sn_info->date_sec = 0; 884 sn_info->date_nsec = 0; 885 sn_info->vm_clock_nsec = 0; 886 } 887 rbd_snap_list_end(snaps); 888 g_free(snaps); 889 890 done: 891 *psn_tab = sn_tab; 892 return snap_count; 893 } 894 895 #ifdef LIBRBD_SUPPORTS_DISCARD 896 static BlockDriverAIOCB* qemu_rbd_aio_discard(BlockDriverState *bs, 897 int64_t sector_num, 898 int nb_sectors, 899 BlockDriverCompletionFunc *cb, 900 void *opaque) 901 { 902 return rbd_start_aio(bs, sector_num, NULL, nb_sectors, cb, opaque, 903 RBD_AIO_DISCARD); 904 } 905 #endif 906 907 static QemuOptsList qemu_rbd_create_opts = { 908 .name = "rbd-create-opts", 909 .head = QTAILQ_HEAD_INITIALIZER(qemu_rbd_create_opts.head), 910 .desc = { 911 { 912 .name = BLOCK_OPT_SIZE, 913 .type = QEMU_OPT_SIZE, 914 .help = "Virtual disk size" 915 }, 916 { 917 .name = BLOCK_OPT_CLUSTER_SIZE, 918 .type = QEMU_OPT_SIZE, 919 .help = "RBD object size" 920 }, 921 { /* end of list */ } 922 } 923 }; 924 925 static BlockDriver bdrv_rbd = { 926 .format_name = "rbd", 927 .instance_size = sizeof(BDRVRBDState), 928 .bdrv_needs_filename = true, 929 .bdrv_file_open = qemu_rbd_open, 930 .bdrv_close = qemu_rbd_close, 931 .bdrv_create = qemu_rbd_create, 932 .bdrv_has_zero_init = bdrv_has_zero_init_1, 933 .bdrv_get_info = qemu_rbd_getinfo, 934 .create_opts = &qemu_rbd_create_opts, 935 .bdrv_getlength = qemu_rbd_getlength, 936 .bdrv_truncate = qemu_rbd_truncate, 937 .protocol_name = "rbd", 938 939 .bdrv_aio_readv = qemu_rbd_aio_readv, 940 .bdrv_aio_writev = qemu_rbd_aio_writev, 941 942 #ifdef LIBRBD_SUPPORTS_AIO_FLUSH 943 .bdrv_aio_flush = qemu_rbd_aio_flush, 944 #else 945 .bdrv_co_flush_to_disk = qemu_rbd_co_flush, 946 #endif 947 948 #ifdef LIBRBD_SUPPORTS_DISCARD 949 .bdrv_aio_discard = qemu_rbd_aio_discard, 950 #endif 951 952 .bdrv_snapshot_create = qemu_rbd_snap_create, 953 .bdrv_snapshot_delete = qemu_rbd_snap_remove, 954 .bdrv_snapshot_list = qemu_rbd_snap_list, 955 .bdrv_snapshot_goto = qemu_rbd_snap_rollback, 956 }; 957 958 static void bdrv_rbd_init(void) 959 { 960 bdrv_register(&bdrv_rbd); 961 } 962 963 block_init(bdrv_rbd_init); 964