1 /* 2 * QEMU System Emulator block driver 3 * 4 * Copyright (c) 2003 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #include "config-host.h" 25 #include "qemu-common.h" 26 #include "monitor.h" 27 #include "block_int.h" 28 #include "module.h" 29 #include "qemu-objects.h" 30 31 #ifdef CONFIG_BSD 32 #include <sys/types.h> 33 #include <sys/stat.h> 34 #include <sys/ioctl.h> 35 #include <sys/queue.h> 36 #ifndef __DragonFly__ 37 #include <sys/disk.h> 38 #endif 39 #endif 40 41 #ifdef _WIN32 42 #include <windows.h> 43 #endif 44 45 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, 46 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 47 BlockDriverCompletionFunc *cb, void *opaque); 48 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, 49 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 50 BlockDriverCompletionFunc *cb, void *opaque); 51 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs, 52 BlockDriverCompletionFunc *cb, void *opaque); 53 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num, 54 uint8_t *buf, int nb_sectors); 55 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num, 56 const uint8_t *buf, int nb_sectors); 57 58 BlockDriverState *bdrv_first; 59 60 static BlockDriver *first_drv; 61 62 /* If non-zero, use only whitelisted block drivers */ 63 static int use_bdrv_whitelist; 64 65 int path_is_absolute(const char *path) 66 { 67 const char *p; 68 #ifdef _WIN32 69 /* specific case for names like: "\\.\d:" */ 70 if (*path == '/' || *path == '\\') 71 return 1; 72 #endif 73 p = strchr(path, ':'); 74 if (p) 75 p++; 76 else 77 p = path; 78 #ifdef _WIN32 79 return (*p == '/' || *p == '\\'); 80 #else 81 return (*p == '/'); 82 #endif 83 } 84 85 /* if filename is absolute, just copy it to dest. Otherwise, build a 86 path to it by considering it is relative to base_path. URL are 87 supported. */ 88 void path_combine(char *dest, int dest_size, 89 const char *base_path, 90 const char *filename) 91 { 92 const char *p, *p1; 93 int len; 94 95 if (dest_size <= 0) 96 return; 97 if (path_is_absolute(filename)) { 98 pstrcpy(dest, dest_size, filename); 99 } else { 100 p = strchr(base_path, ':'); 101 if (p) 102 p++; 103 else 104 p = base_path; 105 p1 = strrchr(base_path, '/'); 106 #ifdef _WIN32 107 { 108 const char *p2; 109 p2 = strrchr(base_path, '\\'); 110 if (!p1 || p2 > p1) 111 p1 = p2; 112 } 113 #endif 114 if (p1) 115 p1++; 116 else 117 p1 = base_path; 118 if (p1 > p) 119 p = p1; 120 len = p - base_path; 121 if (len > dest_size - 1) 122 len = dest_size - 1; 123 memcpy(dest, base_path, len); 124 dest[len] = '\0'; 125 pstrcat(dest, dest_size, filename); 126 } 127 } 128 129 void bdrv_register(BlockDriver *bdrv) 130 { 131 if (!bdrv->bdrv_aio_readv) { 132 /* add AIO emulation layer */ 133 bdrv->bdrv_aio_readv = bdrv_aio_readv_em; 134 bdrv->bdrv_aio_writev = bdrv_aio_writev_em; 135 } else if (!bdrv->bdrv_read) { 136 /* add synchronous IO emulation layer */ 137 bdrv->bdrv_read = bdrv_read_em; 138 bdrv->bdrv_write = bdrv_write_em; 139 } 140 141 if (!bdrv->bdrv_aio_flush) 142 bdrv->bdrv_aio_flush = bdrv_aio_flush_em; 143 144 bdrv->next = first_drv; 145 first_drv = bdrv; 146 } 147 148 /* create a new block device (by default it is empty) */ 149 BlockDriverState *bdrv_new(const char *device_name) 150 { 151 BlockDriverState **pbs, *bs; 152 153 bs = qemu_mallocz(sizeof(BlockDriverState)); 154 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name); 155 if (device_name[0] != '\0') { 156 /* insert at the end */ 157 pbs = &bdrv_first; 158 while (*pbs != NULL) 159 pbs = &(*pbs)->next; 160 *pbs = bs; 161 } 162 return bs; 163 } 164 165 BlockDriver *bdrv_find_format(const char *format_name) 166 { 167 BlockDriver *drv1; 168 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) { 169 if (!strcmp(drv1->format_name, format_name)) 170 return drv1; 171 } 172 return NULL; 173 } 174 175 static int bdrv_is_whitelisted(BlockDriver *drv) 176 { 177 static const char *whitelist[] = { 178 CONFIG_BDRV_WHITELIST 179 }; 180 const char **p; 181 182 if (!whitelist[0]) 183 return 1; /* no whitelist, anything goes */ 184 185 for (p = whitelist; *p; p++) { 186 if (!strcmp(drv->format_name, *p)) { 187 return 1; 188 } 189 } 190 return 0; 191 } 192 193 BlockDriver *bdrv_find_whitelisted_format(const char *format_name) 194 { 195 BlockDriver *drv = bdrv_find_format(format_name); 196 return drv && bdrv_is_whitelisted(drv) ? drv : NULL; 197 } 198 199 int bdrv_create(BlockDriver *drv, const char* filename, 200 QEMUOptionParameter *options) 201 { 202 if (!drv->bdrv_create) 203 return -ENOTSUP; 204 205 return drv->bdrv_create(filename, options); 206 } 207 208 #ifdef _WIN32 209 void get_tmp_filename(char *filename, int size) 210 { 211 char temp_dir[MAX_PATH]; 212 213 GetTempPath(MAX_PATH, temp_dir); 214 GetTempFileName(temp_dir, "qem", 0, filename); 215 } 216 #else 217 void get_tmp_filename(char *filename, int size) 218 { 219 int fd; 220 const char *tmpdir; 221 /* XXX: race condition possible */ 222 tmpdir = getenv("TMPDIR"); 223 if (!tmpdir) 224 tmpdir = "/tmp"; 225 snprintf(filename, size, "%s/vl.XXXXXX", tmpdir); 226 fd = mkstemp(filename); 227 close(fd); 228 } 229 #endif 230 231 #ifdef _WIN32 232 static int is_windows_drive_prefix(const char *filename) 233 { 234 return (((filename[0] >= 'a' && filename[0] <= 'z') || 235 (filename[0] >= 'A' && filename[0] <= 'Z')) && 236 filename[1] == ':'); 237 } 238 239 int is_windows_drive(const char *filename) 240 { 241 if (is_windows_drive_prefix(filename) && 242 filename[2] == '\0') 243 return 1; 244 if (strstart(filename, "\\\\.\\", NULL) || 245 strstart(filename, "//./", NULL)) 246 return 1; 247 return 0; 248 } 249 #endif 250 251 static BlockDriver *find_protocol(const char *filename) 252 { 253 BlockDriver *drv1; 254 char protocol[128]; 255 int len; 256 const char *p; 257 258 #ifdef _WIN32 259 if (is_windows_drive(filename) || 260 is_windows_drive_prefix(filename)) 261 return bdrv_find_format("raw"); 262 #endif 263 p = strchr(filename, ':'); 264 if (!p) 265 return bdrv_find_format("raw"); 266 len = p - filename; 267 if (len > sizeof(protocol) - 1) 268 len = sizeof(protocol) - 1; 269 memcpy(protocol, filename, len); 270 protocol[len] = '\0'; 271 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) { 272 if (drv1->protocol_name && 273 !strcmp(drv1->protocol_name, protocol)) 274 return drv1; 275 } 276 return NULL; 277 } 278 279 /* 280 * Detect host devices. By convention, /dev/cdrom[N] is always 281 * recognized as a host CDROM. 282 */ 283 static BlockDriver *find_hdev_driver(const char *filename) 284 { 285 int score_max = 0, score; 286 BlockDriver *drv = NULL, *d; 287 288 for (d = first_drv; d; d = d->next) { 289 if (d->bdrv_probe_device) { 290 score = d->bdrv_probe_device(filename); 291 if (score > score_max) { 292 score_max = score; 293 drv = d; 294 } 295 } 296 } 297 298 return drv; 299 } 300 301 static BlockDriver *find_image_format(const char *filename) 302 { 303 int ret, score, score_max; 304 BlockDriver *drv1, *drv; 305 uint8_t buf[2048]; 306 BlockDriverState *bs; 307 308 drv = find_protocol(filename); 309 /* no need to test disk image formats for vvfat */ 310 if (drv && strcmp(drv->format_name, "vvfat") == 0) 311 return drv; 312 313 ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY); 314 if (ret < 0) 315 return NULL; 316 ret = bdrv_pread(bs, 0, buf, sizeof(buf)); 317 bdrv_delete(bs); 318 if (ret < 0) { 319 return NULL; 320 } 321 322 score_max = 0; 323 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) { 324 if (drv1->bdrv_probe) { 325 score = drv1->bdrv_probe(buf, ret, filename); 326 if (score > score_max) { 327 score_max = score; 328 drv = drv1; 329 } 330 } 331 } 332 return drv; 333 } 334 335 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags) 336 { 337 BlockDriverState *bs; 338 int ret; 339 340 bs = bdrv_new(""); 341 ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL); 342 if (ret < 0) { 343 bdrv_delete(bs); 344 return ret; 345 } 346 bs->growable = 1; 347 *pbs = bs; 348 return 0; 349 } 350 351 int bdrv_open(BlockDriverState *bs, const char *filename, int flags) 352 { 353 return bdrv_open2(bs, filename, flags, NULL); 354 } 355 356 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags, 357 BlockDriver *drv) 358 { 359 int ret, open_flags, try_rw; 360 char tmp_filename[PATH_MAX]; 361 char backing_filename[PATH_MAX]; 362 363 bs->is_temporary = 0; 364 bs->encrypted = 0; 365 bs->valid_key = 0; 366 /* buffer_alignment defaulted to 512, drivers can change this value */ 367 bs->buffer_alignment = 512; 368 369 if (flags & BDRV_O_SNAPSHOT) { 370 BlockDriverState *bs1; 371 int64_t total_size; 372 int is_protocol = 0; 373 BlockDriver *bdrv_qcow2; 374 QEMUOptionParameter *options; 375 376 /* if snapshot, we create a temporary backing file and open it 377 instead of opening 'filename' directly */ 378 379 /* if there is a backing file, use it */ 380 bs1 = bdrv_new(""); 381 ret = bdrv_open2(bs1, filename, 0, drv); 382 if (ret < 0) { 383 bdrv_delete(bs1); 384 return ret; 385 } 386 total_size = bdrv_getlength(bs1) >> BDRV_SECTOR_BITS; 387 388 if (bs1->drv && bs1->drv->protocol_name) 389 is_protocol = 1; 390 391 bdrv_delete(bs1); 392 393 get_tmp_filename(tmp_filename, sizeof(tmp_filename)); 394 395 /* Real path is meaningless for protocols */ 396 if (is_protocol) 397 snprintf(backing_filename, sizeof(backing_filename), 398 "%s", filename); 399 else if (!realpath(filename, backing_filename)) 400 return -errno; 401 402 bdrv_qcow2 = bdrv_find_format("qcow2"); 403 options = parse_option_parameters("", bdrv_qcow2->create_options, NULL); 404 405 set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size * 512); 406 set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename); 407 if (drv) { 408 set_option_parameter(options, BLOCK_OPT_BACKING_FMT, 409 drv->format_name); 410 } 411 412 ret = bdrv_create(bdrv_qcow2, tmp_filename, options); 413 if (ret < 0) { 414 return ret; 415 } 416 417 filename = tmp_filename; 418 drv = bdrv_qcow2; 419 bs->is_temporary = 1; 420 } 421 422 pstrcpy(bs->filename, sizeof(bs->filename), filename); 423 if (flags & BDRV_O_FILE) { 424 drv = find_protocol(filename); 425 } else if (!drv) { 426 drv = find_hdev_driver(filename); 427 if (!drv) { 428 drv = find_image_format(filename); 429 } 430 } 431 if (!drv) { 432 ret = -ENOENT; 433 goto unlink_and_fail; 434 } 435 bs->drv = drv; 436 bs->opaque = qemu_mallocz(drv->instance_size); 437 438 /* 439 * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a 440 * write cache to the guest. We do need the fdatasync to flush 441 * out transactions for block allocations, and we maybe have a 442 * volatile write cache in our backing device to deal with. 443 */ 444 if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE)) 445 bs->enable_write_cache = 1; 446 447 /* Note: for compatibility, we open disk image files as RDWR, and 448 RDONLY as fallback */ 449 try_rw = !bs->read_only || bs->is_temporary; 450 if (!(flags & BDRV_O_FILE)) 451 open_flags = (try_rw ? BDRV_O_RDWR : 0) | 452 (flags & (BDRV_O_CACHE_MASK|BDRV_O_NATIVE_AIO)); 453 else 454 open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT); 455 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) 456 ret = -ENOTSUP; 457 else 458 ret = drv->bdrv_open(bs, filename, open_flags); 459 if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) { 460 ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR); 461 bs->read_only = 1; 462 } 463 if (ret < 0) { 464 qemu_free(bs->opaque); 465 bs->opaque = NULL; 466 bs->drv = NULL; 467 unlink_and_fail: 468 if (bs->is_temporary) 469 unlink(filename); 470 return ret; 471 } 472 if (drv->bdrv_getlength) { 473 bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; 474 } 475 #ifndef _WIN32 476 if (bs->is_temporary) { 477 unlink(filename); 478 } 479 #endif 480 if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') { 481 /* if there is a backing file, use it */ 482 BlockDriver *back_drv = NULL; 483 bs->backing_hd = bdrv_new(""); 484 /* pass on read_only property to the backing_hd */ 485 bs->backing_hd->read_only = bs->read_only; 486 path_combine(backing_filename, sizeof(backing_filename), 487 filename, bs->backing_file); 488 if (bs->backing_format[0] != '\0') 489 back_drv = bdrv_find_format(bs->backing_format); 490 ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags, 491 back_drv); 492 if (ret < 0) { 493 bdrv_close(bs); 494 return ret; 495 } 496 } 497 498 if (!bdrv_key_required(bs)) { 499 /* call the change callback */ 500 bs->media_changed = 1; 501 if (bs->change_cb) 502 bs->change_cb(bs->change_opaque); 503 } 504 return 0; 505 } 506 507 void bdrv_close(BlockDriverState *bs) 508 { 509 if (bs->drv) { 510 if (bs->backing_hd) 511 bdrv_delete(bs->backing_hd); 512 bs->drv->bdrv_close(bs); 513 qemu_free(bs->opaque); 514 #ifdef _WIN32 515 if (bs->is_temporary) { 516 unlink(bs->filename); 517 } 518 #endif 519 bs->opaque = NULL; 520 bs->drv = NULL; 521 522 /* call the change callback */ 523 bs->media_changed = 1; 524 if (bs->change_cb) 525 bs->change_cb(bs->change_opaque); 526 } 527 } 528 529 void bdrv_delete(BlockDriverState *bs) 530 { 531 BlockDriverState **pbs; 532 533 pbs = &bdrv_first; 534 while (*pbs != bs && *pbs != NULL) 535 pbs = &(*pbs)->next; 536 if (*pbs == bs) 537 *pbs = bs->next; 538 539 bdrv_close(bs); 540 qemu_free(bs); 541 } 542 543 /* 544 * Run consistency checks on an image 545 * 546 * Returns the number of errors or -errno when an internal error occurs 547 */ 548 int bdrv_check(BlockDriverState *bs) 549 { 550 if (bs->drv->bdrv_check == NULL) { 551 return -ENOTSUP; 552 } 553 554 return bs->drv->bdrv_check(bs); 555 } 556 557 /* commit COW file into the raw image */ 558 int bdrv_commit(BlockDriverState *bs) 559 { 560 BlockDriver *drv = bs->drv; 561 int64_t i, total_sectors; 562 int n, j; 563 unsigned char sector[512]; 564 565 if (!drv) 566 return -ENOMEDIUM; 567 568 if (bs->read_only) { 569 return -EACCES; 570 } 571 572 if (!bs->backing_hd) { 573 return -ENOTSUP; 574 } 575 576 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; 577 for (i = 0; i < total_sectors;) { 578 if (drv->bdrv_is_allocated(bs, i, 65536, &n)) { 579 for(j = 0; j < n; j++) { 580 if (bdrv_read(bs, i, sector, 1) != 0) { 581 return -EIO; 582 } 583 584 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) { 585 return -EIO; 586 } 587 i++; 588 } 589 } else { 590 i += n; 591 } 592 } 593 594 if (drv->bdrv_make_empty) 595 return drv->bdrv_make_empty(bs); 596 597 /* 598 * Make sure all data we wrote to the backing device is actually 599 * stable on disk. 600 */ 601 if (bs->backing_hd) 602 bdrv_flush(bs->backing_hd); 603 return 0; 604 } 605 606 /* 607 * Return values: 608 * 0 - success 609 * -EINVAL - backing format specified, but no file 610 * -ENOSPC - can't update the backing file because no space is left in the 611 * image file header 612 * -ENOTSUP - format driver doesn't support changing the backing file 613 */ 614 int bdrv_change_backing_file(BlockDriverState *bs, 615 const char *backing_file, const char *backing_fmt) 616 { 617 BlockDriver *drv = bs->drv; 618 619 if (drv->bdrv_change_backing_file != NULL) { 620 return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); 621 } else { 622 return -ENOTSUP; 623 } 624 } 625 626 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, 627 size_t size) 628 { 629 int64_t len; 630 631 if (!bdrv_is_inserted(bs)) 632 return -ENOMEDIUM; 633 634 if (bs->growable) 635 return 0; 636 637 len = bdrv_getlength(bs); 638 639 if (offset < 0) 640 return -EIO; 641 642 if ((offset > len) || (len - offset < size)) 643 return -EIO; 644 645 return 0; 646 } 647 648 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num, 649 int nb_sectors) 650 { 651 return bdrv_check_byte_request(bs, sector_num * 512, nb_sectors * 512); 652 } 653 654 /* return < 0 if error. See bdrv_write() for the return codes */ 655 int bdrv_read(BlockDriverState *bs, int64_t sector_num, 656 uint8_t *buf, int nb_sectors) 657 { 658 BlockDriver *drv = bs->drv; 659 660 if (!drv) 661 return -ENOMEDIUM; 662 if (bdrv_check_request(bs, sector_num, nb_sectors)) 663 return -EIO; 664 665 return drv->bdrv_read(bs, sector_num, buf, nb_sectors); 666 } 667 668 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num, 669 int nb_sectors, int dirty) 670 { 671 int64_t start, end; 672 unsigned long val, idx, bit; 673 674 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK; 675 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK; 676 677 for (; start <= end; start++) { 678 idx = start / (sizeof(unsigned long) * 8); 679 bit = start % (sizeof(unsigned long) * 8); 680 val = bs->dirty_bitmap[idx]; 681 if (dirty) { 682 val |= 1 << bit; 683 } else { 684 val &= ~(1 << bit); 685 } 686 bs->dirty_bitmap[idx] = val; 687 } 688 } 689 690 /* Return < 0 if error. Important errors are: 691 -EIO generic I/O error (may happen for all errors) 692 -ENOMEDIUM No media inserted. 693 -EINVAL Invalid sector number or nb_sectors 694 -EACCES Trying to write a read-only device 695 */ 696 int bdrv_write(BlockDriverState *bs, int64_t sector_num, 697 const uint8_t *buf, int nb_sectors) 698 { 699 BlockDriver *drv = bs->drv; 700 if (!bs->drv) 701 return -ENOMEDIUM; 702 if (bs->read_only) 703 return -EACCES; 704 if (bdrv_check_request(bs, sector_num, nb_sectors)) 705 return -EIO; 706 707 if (bs->dirty_bitmap) { 708 set_dirty_bitmap(bs, sector_num, nb_sectors, 1); 709 } 710 711 return drv->bdrv_write(bs, sector_num, buf, nb_sectors); 712 } 713 714 int bdrv_pread(BlockDriverState *bs, int64_t offset, 715 void *buf, int count1) 716 { 717 uint8_t tmp_buf[BDRV_SECTOR_SIZE]; 718 int len, nb_sectors, count; 719 int64_t sector_num; 720 721 count = count1; 722 /* first read to align to sector start */ 723 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1); 724 if (len > count) 725 len = count; 726 sector_num = offset >> BDRV_SECTOR_BITS; 727 if (len > 0) { 728 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0) 729 return -EIO; 730 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len); 731 count -= len; 732 if (count == 0) 733 return count1; 734 sector_num++; 735 buf += len; 736 } 737 738 /* read the sectors "in place" */ 739 nb_sectors = count >> BDRV_SECTOR_BITS; 740 if (nb_sectors > 0) { 741 if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0) 742 return -EIO; 743 sector_num += nb_sectors; 744 len = nb_sectors << BDRV_SECTOR_BITS; 745 buf += len; 746 count -= len; 747 } 748 749 /* add data from the last sector */ 750 if (count > 0) { 751 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0) 752 return -EIO; 753 memcpy(buf, tmp_buf, count); 754 } 755 return count1; 756 } 757 758 int bdrv_pwrite(BlockDriverState *bs, int64_t offset, 759 const void *buf, int count1) 760 { 761 uint8_t tmp_buf[BDRV_SECTOR_SIZE]; 762 int len, nb_sectors, count; 763 int64_t sector_num; 764 765 count = count1; 766 /* first write to align to sector start */ 767 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1); 768 if (len > count) 769 len = count; 770 sector_num = offset >> BDRV_SECTOR_BITS; 771 if (len > 0) { 772 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0) 773 return -EIO; 774 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len); 775 if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0) 776 return -EIO; 777 count -= len; 778 if (count == 0) 779 return count1; 780 sector_num++; 781 buf += len; 782 } 783 784 /* write the sectors "in place" */ 785 nb_sectors = count >> BDRV_SECTOR_BITS; 786 if (nb_sectors > 0) { 787 if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0) 788 return -EIO; 789 sector_num += nb_sectors; 790 len = nb_sectors << BDRV_SECTOR_BITS; 791 buf += len; 792 count -= len; 793 } 794 795 /* add data from the last sector */ 796 if (count > 0) { 797 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0) 798 return -EIO; 799 memcpy(tmp_buf, buf, count); 800 if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0) 801 return -EIO; 802 } 803 return count1; 804 } 805 806 /** 807 * Truncate file to 'offset' bytes (needed only for file protocols) 808 */ 809 int bdrv_truncate(BlockDriverState *bs, int64_t offset) 810 { 811 BlockDriver *drv = bs->drv; 812 if (!drv) 813 return -ENOMEDIUM; 814 if (!drv->bdrv_truncate) 815 return -ENOTSUP; 816 if (bs->read_only) 817 return -EACCES; 818 return drv->bdrv_truncate(bs, offset); 819 } 820 821 /** 822 * Length of a file in bytes. Return < 0 if error or unknown. 823 */ 824 int64_t bdrv_getlength(BlockDriverState *bs) 825 { 826 BlockDriver *drv = bs->drv; 827 if (!drv) 828 return -ENOMEDIUM; 829 if (!drv->bdrv_getlength) { 830 /* legacy mode */ 831 return bs->total_sectors * BDRV_SECTOR_SIZE; 832 } 833 return drv->bdrv_getlength(bs); 834 } 835 836 /* return 0 as number of sectors if no device present or error */ 837 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) 838 { 839 int64_t length; 840 length = bdrv_getlength(bs); 841 if (length < 0) 842 length = 0; 843 else 844 length = length >> BDRV_SECTOR_BITS; 845 *nb_sectors_ptr = length; 846 } 847 848 struct partition { 849 uint8_t boot_ind; /* 0x80 - active */ 850 uint8_t head; /* starting head */ 851 uint8_t sector; /* starting sector */ 852 uint8_t cyl; /* starting cylinder */ 853 uint8_t sys_ind; /* What partition type */ 854 uint8_t end_head; /* end head */ 855 uint8_t end_sector; /* end sector */ 856 uint8_t end_cyl; /* end cylinder */ 857 uint32_t start_sect; /* starting sector counting from 0 */ 858 uint32_t nr_sects; /* nr of sectors in partition */ 859 } __attribute__((packed)); 860 861 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */ 862 static int guess_disk_lchs(BlockDriverState *bs, 863 int *pcylinders, int *pheads, int *psectors) 864 { 865 uint8_t buf[512]; 866 int ret, i, heads, sectors, cylinders; 867 struct partition *p; 868 uint32_t nr_sects; 869 uint64_t nb_sectors; 870 871 bdrv_get_geometry(bs, &nb_sectors); 872 873 ret = bdrv_read(bs, 0, buf, 1); 874 if (ret < 0) 875 return -1; 876 /* test msdos magic */ 877 if (buf[510] != 0x55 || buf[511] != 0xaa) 878 return -1; 879 for(i = 0; i < 4; i++) { 880 p = ((struct partition *)(buf + 0x1be)) + i; 881 nr_sects = le32_to_cpu(p->nr_sects); 882 if (nr_sects && p->end_head) { 883 /* We make the assumption that the partition terminates on 884 a cylinder boundary */ 885 heads = p->end_head + 1; 886 sectors = p->end_sector & 63; 887 if (sectors == 0) 888 continue; 889 cylinders = nb_sectors / (heads * sectors); 890 if (cylinders < 1 || cylinders > 16383) 891 continue; 892 *pheads = heads; 893 *psectors = sectors; 894 *pcylinders = cylinders; 895 #if 0 896 printf("guessed geometry: LCHS=%d %d %d\n", 897 cylinders, heads, sectors); 898 #endif 899 return 0; 900 } 901 } 902 return -1; 903 } 904 905 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs) 906 { 907 int translation, lba_detected = 0; 908 int cylinders, heads, secs; 909 uint64_t nb_sectors; 910 911 /* if a geometry hint is available, use it */ 912 bdrv_get_geometry(bs, &nb_sectors); 913 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs); 914 translation = bdrv_get_translation_hint(bs); 915 if (cylinders != 0) { 916 *pcyls = cylinders; 917 *pheads = heads; 918 *psecs = secs; 919 } else { 920 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) { 921 if (heads > 16) { 922 /* if heads > 16, it means that a BIOS LBA 923 translation was active, so the default 924 hardware geometry is OK */ 925 lba_detected = 1; 926 goto default_geometry; 927 } else { 928 *pcyls = cylinders; 929 *pheads = heads; 930 *psecs = secs; 931 /* disable any translation to be in sync with 932 the logical geometry */ 933 if (translation == BIOS_ATA_TRANSLATION_AUTO) { 934 bdrv_set_translation_hint(bs, 935 BIOS_ATA_TRANSLATION_NONE); 936 } 937 } 938 } else { 939 default_geometry: 940 /* if no geometry, use a standard physical disk geometry */ 941 cylinders = nb_sectors / (16 * 63); 942 943 if (cylinders > 16383) 944 cylinders = 16383; 945 else if (cylinders < 2) 946 cylinders = 2; 947 *pcyls = cylinders; 948 *pheads = 16; 949 *psecs = 63; 950 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) { 951 if ((*pcyls * *pheads) <= 131072) { 952 bdrv_set_translation_hint(bs, 953 BIOS_ATA_TRANSLATION_LARGE); 954 } else { 955 bdrv_set_translation_hint(bs, 956 BIOS_ATA_TRANSLATION_LBA); 957 } 958 } 959 } 960 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs); 961 } 962 } 963 964 void bdrv_set_geometry_hint(BlockDriverState *bs, 965 int cyls, int heads, int secs) 966 { 967 bs->cyls = cyls; 968 bs->heads = heads; 969 bs->secs = secs; 970 } 971 972 void bdrv_set_type_hint(BlockDriverState *bs, int type) 973 { 974 bs->type = type; 975 bs->removable = ((type == BDRV_TYPE_CDROM || 976 type == BDRV_TYPE_FLOPPY)); 977 } 978 979 void bdrv_set_translation_hint(BlockDriverState *bs, int translation) 980 { 981 bs->translation = translation; 982 } 983 984 void bdrv_get_geometry_hint(BlockDriverState *bs, 985 int *pcyls, int *pheads, int *psecs) 986 { 987 *pcyls = bs->cyls; 988 *pheads = bs->heads; 989 *psecs = bs->secs; 990 } 991 992 int bdrv_get_type_hint(BlockDriverState *bs) 993 { 994 return bs->type; 995 } 996 997 int bdrv_get_translation_hint(BlockDriverState *bs) 998 { 999 return bs->translation; 1000 } 1001 1002 int bdrv_is_removable(BlockDriverState *bs) 1003 { 1004 return bs->removable; 1005 } 1006 1007 int bdrv_is_read_only(BlockDriverState *bs) 1008 { 1009 return bs->read_only; 1010 } 1011 1012 int bdrv_set_read_only(BlockDriverState *bs, int read_only) 1013 { 1014 int ret = bs->read_only; 1015 bs->read_only = read_only; 1016 return ret; 1017 } 1018 1019 int bdrv_is_sg(BlockDriverState *bs) 1020 { 1021 return bs->sg; 1022 } 1023 1024 int bdrv_enable_write_cache(BlockDriverState *bs) 1025 { 1026 return bs->enable_write_cache; 1027 } 1028 1029 /* XXX: no longer used */ 1030 void bdrv_set_change_cb(BlockDriverState *bs, 1031 void (*change_cb)(void *opaque), void *opaque) 1032 { 1033 bs->change_cb = change_cb; 1034 bs->change_opaque = opaque; 1035 } 1036 1037 int bdrv_is_encrypted(BlockDriverState *bs) 1038 { 1039 if (bs->backing_hd && bs->backing_hd->encrypted) 1040 return 1; 1041 return bs->encrypted; 1042 } 1043 1044 int bdrv_key_required(BlockDriverState *bs) 1045 { 1046 BlockDriverState *backing_hd = bs->backing_hd; 1047 1048 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key) 1049 return 1; 1050 return (bs->encrypted && !bs->valid_key); 1051 } 1052 1053 int bdrv_set_key(BlockDriverState *bs, const char *key) 1054 { 1055 int ret; 1056 if (bs->backing_hd && bs->backing_hd->encrypted) { 1057 ret = bdrv_set_key(bs->backing_hd, key); 1058 if (ret < 0) 1059 return ret; 1060 if (!bs->encrypted) 1061 return 0; 1062 } 1063 if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key) 1064 return -1; 1065 ret = bs->drv->bdrv_set_key(bs, key); 1066 if (ret < 0) { 1067 bs->valid_key = 0; 1068 } else if (!bs->valid_key) { 1069 bs->valid_key = 1; 1070 /* call the change callback now, we skipped it on open */ 1071 bs->media_changed = 1; 1072 if (bs->change_cb) 1073 bs->change_cb(bs->change_opaque); 1074 } 1075 return ret; 1076 } 1077 1078 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size) 1079 { 1080 if (!bs->drv) { 1081 buf[0] = '\0'; 1082 } else { 1083 pstrcpy(buf, buf_size, bs->drv->format_name); 1084 } 1085 } 1086 1087 void bdrv_iterate_format(void (*it)(void *opaque, const char *name), 1088 void *opaque) 1089 { 1090 BlockDriver *drv; 1091 1092 for (drv = first_drv; drv != NULL; drv = drv->next) { 1093 it(opaque, drv->format_name); 1094 } 1095 } 1096 1097 BlockDriverState *bdrv_find(const char *name) 1098 { 1099 BlockDriverState *bs; 1100 1101 for (bs = bdrv_first; bs != NULL; bs = bs->next) { 1102 if (!strcmp(name, bs->device_name)) 1103 return bs; 1104 } 1105 return NULL; 1106 } 1107 1108 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque) 1109 { 1110 BlockDriverState *bs; 1111 1112 for (bs = bdrv_first; bs != NULL; bs = bs->next) { 1113 it(opaque, bs); 1114 } 1115 } 1116 1117 const char *bdrv_get_device_name(BlockDriverState *bs) 1118 { 1119 return bs->device_name; 1120 } 1121 1122 void bdrv_flush(BlockDriverState *bs) 1123 { 1124 if (bs->drv && bs->drv->bdrv_flush) 1125 bs->drv->bdrv_flush(bs); 1126 } 1127 1128 void bdrv_flush_all(void) 1129 { 1130 BlockDriverState *bs; 1131 1132 for (bs = bdrv_first; bs != NULL; bs = bs->next) 1133 if (bs->drv && !bdrv_is_read_only(bs) && 1134 (!bdrv_is_removable(bs) || bdrv_is_inserted(bs))) 1135 bdrv_flush(bs); 1136 } 1137 1138 /* 1139 * Returns true iff the specified sector is present in the disk image. Drivers 1140 * not implementing the functionality are assumed to not support backing files, 1141 * hence all their sectors are reported as allocated. 1142 * 1143 * 'pnum' is set to the number of sectors (including and immediately following 1144 * the specified sector) that are known to be in the same 1145 * allocated/unallocated state. 1146 * 1147 * 'nb_sectors' is the max value 'pnum' should be set to. 1148 */ 1149 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, 1150 int *pnum) 1151 { 1152 int64_t n; 1153 if (!bs->drv->bdrv_is_allocated) { 1154 if (sector_num >= bs->total_sectors) { 1155 *pnum = 0; 1156 return 0; 1157 } 1158 n = bs->total_sectors - sector_num; 1159 *pnum = (n < nb_sectors) ? (n) : (nb_sectors); 1160 return 1; 1161 } 1162 return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum); 1163 } 1164 1165 static void bdrv_print_dict(QObject *obj, void *opaque) 1166 { 1167 QDict *bs_dict; 1168 Monitor *mon = opaque; 1169 1170 bs_dict = qobject_to_qdict(obj); 1171 1172 monitor_printf(mon, "%s: type=%s removable=%d", 1173 qdict_get_str(bs_dict, "device"), 1174 qdict_get_str(bs_dict, "type"), 1175 qdict_get_bool(bs_dict, "removable")); 1176 1177 if (qdict_get_bool(bs_dict, "removable")) { 1178 monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked")); 1179 } 1180 1181 if (qdict_haskey(bs_dict, "inserted")) { 1182 QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted")); 1183 1184 monitor_printf(mon, " file="); 1185 monitor_print_filename(mon, qdict_get_str(qdict, "file")); 1186 if (qdict_haskey(qdict, "backing_file")) { 1187 monitor_printf(mon, " backing_file="); 1188 monitor_print_filename(mon, qdict_get_str(qdict, "backing_file")); 1189 } 1190 monitor_printf(mon, " ro=%d drv=%s encrypted=%d", 1191 qdict_get_bool(qdict, "ro"), 1192 qdict_get_str(qdict, "drv"), 1193 qdict_get_bool(qdict, "encrypted")); 1194 } else { 1195 monitor_printf(mon, " [not inserted]"); 1196 } 1197 1198 monitor_printf(mon, "\n"); 1199 } 1200 1201 void bdrv_info_print(Monitor *mon, const QObject *data) 1202 { 1203 qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon); 1204 } 1205 1206 /** 1207 * bdrv_info(): Block devices information 1208 * 1209 * Each block device information is stored in a QDict and the 1210 * returned QObject is a QList of all devices. 1211 * 1212 * The QDict contains the following: 1213 * 1214 * - "device": device name 1215 * - "type": device type 1216 * - "removable": true if the device is removable, false otherwise 1217 * - "locked": true if the device is locked, false otherwise 1218 * - "inserted": only present if the device is inserted, it is a QDict 1219 * containing the following: 1220 * - "file": device file name 1221 * - "ro": true if read-only, false otherwise 1222 * - "drv": driver format name 1223 * - "backing_file": backing file name if one is used 1224 * - "encrypted": true if encrypted, false otherwise 1225 * 1226 * Example: 1227 * 1228 * [ { "device": "ide0-hd0", "type": "hd", "removable": false, "locked": false, 1229 * "inserted": { "file": "/tmp/foobar", "ro": false, "drv": "qcow2" } }, 1230 * { "device": "floppy0", "type": "floppy", "removable": true, 1231 * "locked": false } ] 1232 */ 1233 void bdrv_info(Monitor *mon, QObject **ret_data) 1234 { 1235 QList *bs_list; 1236 BlockDriverState *bs; 1237 1238 bs_list = qlist_new(); 1239 1240 for (bs = bdrv_first; bs != NULL; bs = bs->next) { 1241 QObject *bs_obj; 1242 const char *type = "unknown"; 1243 1244 switch(bs->type) { 1245 case BDRV_TYPE_HD: 1246 type = "hd"; 1247 break; 1248 case BDRV_TYPE_CDROM: 1249 type = "cdrom"; 1250 break; 1251 case BDRV_TYPE_FLOPPY: 1252 type = "floppy"; 1253 break; 1254 } 1255 1256 bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, " 1257 "'removable': %i, 'locked': %i }", 1258 bs->device_name, type, bs->removable, 1259 bs->locked); 1260 assert(bs_obj != NULL); 1261 1262 if (bs->drv) { 1263 QObject *obj; 1264 QDict *bs_dict = qobject_to_qdict(bs_obj); 1265 1266 obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, " 1267 "'encrypted': %i }", 1268 bs->filename, bs->read_only, 1269 bs->drv->format_name, 1270 bdrv_is_encrypted(bs)); 1271 assert(obj != NULL); 1272 if (bs->backing_file[0] != '\0') { 1273 QDict *qdict = qobject_to_qdict(obj); 1274 qdict_put(qdict, "backing_file", 1275 qstring_from_str(bs->backing_file)); 1276 } 1277 1278 qdict_put_obj(bs_dict, "inserted", obj); 1279 } 1280 qlist_append_obj(bs_list, bs_obj); 1281 } 1282 1283 *ret_data = QOBJECT(bs_list); 1284 } 1285 1286 static void bdrv_stats_iter(QObject *data, void *opaque) 1287 { 1288 QDict *qdict; 1289 Monitor *mon = opaque; 1290 1291 qdict = qobject_to_qdict(data); 1292 monitor_printf(mon, "%s:", qdict_get_str(qdict, "device")); 1293 1294 qdict = qobject_to_qdict(qdict_get(qdict, "stats")); 1295 monitor_printf(mon, " rd_bytes=%" PRId64 1296 " wr_bytes=%" PRId64 1297 " rd_operations=%" PRId64 1298 " wr_operations=%" PRId64 1299 "\n", 1300 qdict_get_int(qdict, "rd_bytes"), 1301 qdict_get_int(qdict, "wr_bytes"), 1302 qdict_get_int(qdict, "rd_operations"), 1303 qdict_get_int(qdict, "wr_operations")); 1304 } 1305 1306 void bdrv_stats_print(Monitor *mon, const QObject *data) 1307 { 1308 qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon); 1309 } 1310 1311 /** 1312 * bdrv_info_stats(): show block device statistics 1313 * 1314 * Each device statistic information is stored in a QDict and 1315 * the returned QObject is a QList of all devices. 1316 * 1317 * The QDict contains the following: 1318 * 1319 * - "device": device name 1320 * - "stats": A QDict with the statistics information, it contains: 1321 * - "rd_bytes": bytes read 1322 * - "wr_bytes": bytes written 1323 * - "rd_operations": read operations 1324 * - "wr_operations": write operations 1325 * 1326 * Example: 1327 * 1328 * [ { "device": "ide0-hd0", 1329 * "stats": { "rd_bytes": 512, 1330 * "wr_bytes": 0, 1331 * "rd_operations": 1, 1332 * "wr_operations": 0 } }, 1333 * { "device": "ide1-cd0", 1334 * "stats": { "rd_bytes": 0, 1335 * "wr_bytes": 0, 1336 * "rd_operations": 0, 1337 * "wr_operations": 0 } } ] 1338 */ 1339 void bdrv_info_stats(Monitor *mon, QObject **ret_data) 1340 { 1341 QObject *obj; 1342 QList *devices; 1343 BlockDriverState *bs; 1344 1345 devices = qlist_new(); 1346 1347 for (bs = bdrv_first; bs != NULL; bs = bs->next) { 1348 obj = qobject_from_jsonf("{ 'device': %s, 'stats': {" 1349 "'rd_bytes': %" PRId64 "," 1350 "'wr_bytes': %" PRId64 "," 1351 "'rd_operations': %" PRId64 "," 1352 "'wr_operations': %" PRId64 1353 "} }", 1354 bs->device_name, 1355 bs->rd_bytes, bs->wr_bytes, 1356 bs->rd_ops, bs->wr_ops); 1357 assert(obj != NULL); 1358 qlist_append_obj(devices, obj); 1359 } 1360 1361 *ret_data = QOBJECT(devices); 1362 } 1363 1364 const char *bdrv_get_encrypted_filename(BlockDriverState *bs) 1365 { 1366 if (bs->backing_hd && bs->backing_hd->encrypted) 1367 return bs->backing_file; 1368 else if (bs->encrypted) 1369 return bs->filename; 1370 else 1371 return NULL; 1372 } 1373 1374 void bdrv_get_backing_filename(BlockDriverState *bs, 1375 char *filename, int filename_size) 1376 { 1377 if (!bs->backing_file) { 1378 pstrcpy(filename, filename_size, ""); 1379 } else { 1380 pstrcpy(filename, filename_size, bs->backing_file); 1381 } 1382 } 1383 1384 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num, 1385 const uint8_t *buf, int nb_sectors) 1386 { 1387 BlockDriver *drv = bs->drv; 1388 if (!drv) 1389 return -ENOMEDIUM; 1390 if (!drv->bdrv_write_compressed) 1391 return -ENOTSUP; 1392 if (bdrv_check_request(bs, sector_num, nb_sectors)) 1393 return -EIO; 1394 1395 if (bs->dirty_bitmap) { 1396 set_dirty_bitmap(bs, sector_num, nb_sectors, 1); 1397 } 1398 1399 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); 1400 } 1401 1402 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1403 { 1404 BlockDriver *drv = bs->drv; 1405 if (!drv) 1406 return -ENOMEDIUM; 1407 if (!drv->bdrv_get_info) 1408 return -ENOTSUP; 1409 memset(bdi, 0, sizeof(*bdi)); 1410 return drv->bdrv_get_info(bs, bdi); 1411 } 1412 1413 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, 1414 int64_t pos, int size) 1415 { 1416 BlockDriver *drv = bs->drv; 1417 if (!drv) 1418 return -ENOMEDIUM; 1419 if (!drv->bdrv_save_vmstate) 1420 return -ENOTSUP; 1421 return drv->bdrv_save_vmstate(bs, buf, pos, size); 1422 } 1423 1424 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, 1425 int64_t pos, int size) 1426 { 1427 BlockDriver *drv = bs->drv; 1428 if (!drv) 1429 return -ENOMEDIUM; 1430 if (!drv->bdrv_load_vmstate) 1431 return -ENOTSUP; 1432 return drv->bdrv_load_vmstate(bs, buf, pos, size); 1433 } 1434 1435 /**************************************************************/ 1436 /* handling of snapshots */ 1437 1438 int bdrv_snapshot_create(BlockDriverState *bs, 1439 QEMUSnapshotInfo *sn_info) 1440 { 1441 BlockDriver *drv = bs->drv; 1442 if (!drv) 1443 return -ENOMEDIUM; 1444 if (!drv->bdrv_snapshot_create) 1445 return -ENOTSUP; 1446 return drv->bdrv_snapshot_create(bs, sn_info); 1447 } 1448 1449 int bdrv_snapshot_goto(BlockDriverState *bs, 1450 const char *snapshot_id) 1451 { 1452 BlockDriver *drv = bs->drv; 1453 if (!drv) 1454 return -ENOMEDIUM; 1455 if (!drv->bdrv_snapshot_goto) 1456 return -ENOTSUP; 1457 return drv->bdrv_snapshot_goto(bs, snapshot_id); 1458 } 1459 1460 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) 1461 { 1462 BlockDriver *drv = bs->drv; 1463 if (!drv) 1464 return -ENOMEDIUM; 1465 if (!drv->bdrv_snapshot_delete) 1466 return -ENOTSUP; 1467 return drv->bdrv_snapshot_delete(bs, snapshot_id); 1468 } 1469 1470 int bdrv_snapshot_list(BlockDriverState *bs, 1471 QEMUSnapshotInfo **psn_info) 1472 { 1473 BlockDriver *drv = bs->drv; 1474 if (!drv) 1475 return -ENOMEDIUM; 1476 if (!drv->bdrv_snapshot_list) 1477 return -ENOTSUP; 1478 return drv->bdrv_snapshot_list(bs, psn_info); 1479 } 1480 1481 #define NB_SUFFIXES 4 1482 1483 char *get_human_readable_size(char *buf, int buf_size, int64_t size) 1484 { 1485 static const char suffixes[NB_SUFFIXES] = "KMGT"; 1486 int64_t base; 1487 int i; 1488 1489 if (size <= 999) { 1490 snprintf(buf, buf_size, "%" PRId64, size); 1491 } else { 1492 base = 1024; 1493 for(i = 0; i < NB_SUFFIXES; i++) { 1494 if (size < (10 * base)) { 1495 snprintf(buf, buf_size, "%0.1f%c", 1496 (double)size / base, 1497 suffixes[i]); 1498 break; 1499 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) { 1500 snprintf(buf, buf_size, "%" PRId64 "%c", 1501 ((size + (base >> 1)) / base), 1502 suffixes[i]); 1503 break; 1504 } 1505 base = base * 1024; 1506 } 1507 } 1508 return buf; 1509 } 1510 1511 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn) 1512 { 1513 char buf1[128], date_buf[128], clock_buf[128]; 1514 #ifdef _WIN32 1515 struct tm *ptm; 1516 #else 1517 struct tm tm; 1518 #endif 1519 time_t ti; 1520 int64_t secs; 1521 1522 if (!sn) { 1523 snprintf(buf, buf_size, 1524 "%-10s%-20s%7s%20s%15s", 1525 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK"); 1526 } else { 1527 ti = sn->date_sec; 1528 #ifdef _WIN32 1529 ptm = localtime(&ti); 1530 strftime(date_buf, sizeof(date_buf), 1531 "%Y-%m-%d %H:%M:%S", ptm); 1532 #else 1533 localtime_r(&ti, &tm); 1534 strftime(date_buf, sizeof(date_buf), 1535 "%Y-%m-%d %H:%M:%S", &tm); 1536 #endif 1537 secs = sn->vm_clock_nsec / 1000000000; 1538 snprintf(clock_buf, sizeof(clock_buf), 1539 "%02d:%02d:%02d.%03d", 1540 (int)(secs / 3600), 1541 (int)((secs / 60) % 60), 1542 (int)(secs % 60), 1543 (int)((sn->vm_clock_nsec / 1000000) % 1000)); 1544 snprintf(buf, buf_size, 1545 "%-10s%-20s%7s%20s%15s", 1546 sn->id_str, sn->name, 1547 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size), 1548 date_buf, 1549 clock_buf); 1550 } 1551 return buf; 1552 } 1553 1554 1555 /**************************************************************/ 1556 /* async I/Os */ 1557 1558 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, 1559 QEMUIOVector *qiov, int nb_sectors, 1560 BlockDriverCompletionFunc *cb, void *opaque) 1561 { 1562 BlockDriver *drv = bs->drv; 1563 BlockDriverAIOCB *ret; 1564 1565 if (!drv) 1566 return NULL; 1567 if (bdrv_check_request(bs, sector_num, nb_sectors)) 1568 return NULL; 1569 1570 ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors, 1571 cb, opaque); 1572 1573 if (ret) { 1574 /* Update stats even though technically transfer has not happened. */ 1575 bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE; 1576 bs->rd_ops ++; 1577 } 1578 1579 return ret; 1580 } 1581 1582 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, 1583 QEMUIOVector *qiov, int nb_sectors, 1584 BlockDriverCompletionFunc *cb, void *opaque) 1585 { 1586 BlockDriver *drv = bs->drv; 1587 BlockDriverAIOCB *ret; 1588 1589 if (!drv) 1590 return NULL; 1591 if (bs->read_only) 1592 return NULL; 1593 if (bdrv_check_request(bs, sector_num, nb_sectors)) 1594 return NULL; 1595 1596 if (bs->dirty_bitmap) { 1597 set_dirty_bitmap(bs, sector_num, nb_sectors, 1); 1598 } 1599 1600 ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors, 1601 cb, opaque); 1602 1603 if (ret) { 1604 /* Update stats even though technically transfer has not happened. */ 1605 bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE; 1606 bs->wr_ops ++; 1607 } 1608 1609 return ret; 1610 } 1611 1612 1613 typedef struct MultiwriteCB { 1614 int error; 1615 int num_requests; 1616 int num_callbacks; 1617 struct { 1618 BlockDriverCompletionFunc *cb; 1619 void *opaque; 1620 QEMUIOVector *free_qiov; 1621 void *free_buf; 1622 } callbacks[]; 1623 } MultiwriteCB; 1624 1625 static void multiwrite_user_cb(MultiwriteCB *mcb) 1626 { 1627 int i; 1628 1629 for (i = 0; i < mcb->num_callbacks; i++) { 1630 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error); 1631 qemu_free(mcb->callbacks[i].free_qiov); 1632 qemu_free(mcb->callbacks[i].free_buf); 1633 } 1634 } 1635 1636 static void multiwrite_cb(void *opaque, int ret) 1637 { 1638 MultiwriteCB *mcb = opaque; 1639 1640 if (ret < 0) { 1641 mcb->error = ret; 1642 multiwrite_user_cb(mcb); 1643 } 1644 1645 mcb->num_requests--; 1646 if (mcb->num_requests == 0) { 1647 if (mcb->error == 0) { 1648 multiwrite_user_cb(mcb); 1649 } 1650 qemu_free(mcb); 1651 } 1652 } 1653 1654 static int multiwrite_req_compare(const void *a, const void *b) 1655 { 1656 return (((BlockRequest*) a)->sector - ((BlockRequest*) b)->sector); 1657 } 1658 1659 /* 1660 * Takes a bunch of requests and tries to merge them. Returns the number of 1661 * requests that remain after merging. 1662 */ 1663 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, 1664 int num_reqs, MultiwriteCB *mcb) 1665 { 1666 int i, outidx; 1667 1668 // Sort requests by start sector 1669 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare); 1670 1671 // Check if adjacent requests touch the same clusters. If so, combine them, 1672 // filling up gaps with zero sectors. 1673 outidx = 0; 1674 for (i = 1; i < num_reqs; i++) { 1675 int merge = 0; 1676 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors; 1677 1678 // This handles the cases that are valid for all block drivers, namely 1679 // exactly sequential writes and overlapping writes. 1680 if (reqs[i].sector <= oldreq_last) { 1681 merge = 1; 1682 } 1683 1684 // The block driver may decide that it makes sense to combine requests 1685 // even if there is a gap of some sectors between them. In this case, 1686 // the gap is filled with zeros (therefore only applicable for yet 1687 // unused space in format like qcow2). 1688 if (!merge && bs->drv->bdrv_merge_requests) { 1689 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]); 1690 } 1691 1692 if (merge) { 1693 size_t size; 1694 QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov)); 1695 qemu_iovec_init(qiov, 1696 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1); 1697 1698 // Add the first request to the merged one. If the requests are 1699 // overlapping, drop the last sectors of the first request. 1700 size = (reqs[i].sector - reqs[outidx].sector) << 9; 1701 qemu_iovec_concat(qiov, reqs[outidx].qiov, size); 1702 1703 // We might need to add some zeros between the two requests 1704 if (reqs[i].sector > oldreq_last) { 1705 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9; 1706 uint8_t *buf = qemu_blockalign(bs, zero_bytes); 1707 memset(buf, 0, zero_bytes); 1708 qemu_iovec_add(qiov, buf, zero_bytes); 1709 mcb->callbacks[i].free_buf = buf; 1710 } 1711 1712 // Add the second request 1713 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size); 1714 1715 reqs[outidx].nb_sectors += reqs[i].nb_sectors; 1716 reqs[outidx].qiov = qiov; 1717 1718 mcb->callbacks[i].free_qiov = reqs[outidx].qiov; 1719 } else { 1720 outidx++; 1721 reqs[outidx].sector = reqs[i].sector; 1722 reqs[outidx].nb_sectors = reqs[i].nb_sectors; 1723 reqs[outidx].qiov = reqs[i].qiov; 1724 } 1725 } 1726 1727 return outidx + 1; 1728 } 1729 1730 /* 1731 * Submit multiple AIO write requests at once. 1732 * 1733 * On success, the function returns 0 and all requests in the reqs array have 1734 * been submitted. In error case this function returns -1, and any of the 1735 * requests may or may not be submitted yet. In particular, this means that the 1736 * callback will be called for some of the requests, for others it won't. The 1737 * caller must check the error field of the BlockRequest to wait for the right 1738 * callbacks (if error != 0, no callback will be called). 1739 * 1740 * The implementation may modify the contents of the reqs array, e.g. to merge 1741 * requests. However, the fields opaque and error are left unmodified as they 1742 * are used to signal failure for a single request to the caller. 1743 */ 1744 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) 1745 { 1746 BlockDriverAIOCB *acb; 1747 MultiwriteCB *mcb; 1748 int i; 1749 1750 if (num_reqs == 0) { 1751 return 0; 1752 } 1753 1754 // Create MultiwriteCB structure 1755 mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); 1756 mcb->num_requests = 0; 1757 mcb->num_callbacks = num_reqs; 1758 1759 for (i = 0; i < num_reqs; i++) { 1760 mcb->callbacks[i].cb = reqs[i].cb; 1761 mcb->callbacks[i].opaque = reqs[i].opaque; 1762 } 1763 1764 // Check for mergable requests 1765 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb); 1766 1767 // Run the aio requests 1768 for (i = 0; i < num_reqs; i++) { 1769 acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov, 1770 reqs[i].nb_sectors, multiwrite_cb, mcb); 1771 1772 if (acb == NULL) { 1773 // We can only fail the whole thing if no request has been 1774 // submitted yet. Otherwise we'll wait for the submitted AIOs to 1775 // complete and report the error in the callback. 1776 if (mcb->num_requests == 0) { 1777 reqs[i].error = EIO; 1778 goto fail; 1779 } else { 1780 mcb->error = EIO; 1781 break; 1782 } 1783 } else { 1784 mcb->num_requests++; 1785 } 1786 } 1787 1788 return 0; 1789 1790 fail: 1791 free(mcb); 1792 return -1; 1793 } 1794 1795 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs, 1796 BlockDriverCompletionFunc *cb, void *opaque) 1797 { 1798 BlockDriver *drv = bs->drv; 1799 1800 if (!drv) 1801 return NULL; 1802 return drv->bdrv_aio_flush(bs, cb, opaque); 1803 } 1804 1805 void bdrv_aio_cancel(BlockDriverAIOCB *acb) 1806 { 1807 acb->pool->cancel(acb); 1808 } 1809 1810 1811 /**************************************************************/ 1812 /* async block device emulation */ 1813 1814 typedef struct BlockDriverAIOCBSync { 1815 BlockDriverAIOCB common; 1816 QEMUBH *bh; 1817 int ret; 1818 /* vector translation state */ 1819 QEMUIOVector *qiov; 1820 uint8_t *bounce; 1821 int is_write; 1822 } BlockDriverAIOCBSync; 1823 1824 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb) 1825 { 1826 BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb; 1827 qemu_bh_delete(acb->bh); 1828 acb->bh = NULL; 1829 qemu_aio_release(acb); 1830 } 1831 1832 static AIOPool bdrv_em_aio_pool = { 1833 .aiocb_size = sizeof(BlockDriverAIOCBSync), 1834 .cancel = bdrv_aio_cancel_em, 1835 }; 1836 1837 static void bdrv_aio_bh_cb(void *opaque) 1838 { 1839 BlockDriverAIOCBSync *acb = opaque; 1840 1841 if (!acb->is_write) 1842 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size); 1843 qemu_vfree(acb->bounce); 1844 acb->common.cb(acb->common.opaque, acb->ret); 1845 qemu_bh_delete(acb->bh); 1846 acb->bh = NULL; 1847 qemu_aio_release(acb); 1848 } 1849 1850 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs, 1851 int64_t sector_num, 1852 QEMUIOVector *qiov, 1853 int nb_sectors, 1854 BlockDriverCompletionFunc *cb, 1855 void *opaque, 1856 int is_write) 1857 1858 { 1859 BlockDriverAIOCBSync *acb; 1860 1861 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque); 1862 acb->is_write = is_write; 1863 acb->qiov = qiov; 1864 acb->bounce = qemu_blockalign(bs, qiov->size); 1865 1866 if (!acb->bh) 1867 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb); 1868 1869 if (is_write) { 1870 qemu_iovec_to_buffer(acb->qiov, acb->bounce); 1871 acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors); 1872 } else { 1873 acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors); 1874 } 1875 1876 qemu_bh_schedule(acb->bh); 1877 1878 return &acb->common; 1879 } 1880 1881 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, 1882 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 1883 BlockDriverCompletionFunc *cb, void *opaque) 1884 { 1885 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); 1886 } 1887 1888 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, 1889 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 1890 BlockDriverCompletionFunc *cb, void *opaque) 1891 { 1892 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); 1893 } 1894 1895 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs, 1896 BlockDriverCompletionFunc *cb, void *opaque) 1897 { 1898 BlockDriverAIOCBSync *acb; 1899 1900 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque); 1901 acb->is_write = 1; /* don't bounce in the completion hadler */ 1902 acb->qiov = NULL; 1903 acb->bounce = NULL; 1904 acb->ret = 0; 1905 1906 if (!acb->bh) 1907 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb); 1908 1909 bdrv_flush(bs); 1910 qemu_bh_schedule(acb->bh); 1911 return &acb->common; 1912 } 1913 1914 /**************************************************************/ 1915 /* sync block device emulation */ 1916 1917 static void bdrv_rw_em_cb(void *opaque, int ret) 1918 { 1919 *(int *)opaque = ret; 1920 } 1921 1922 #define NOT_DONE 0x7fffffff 1923 1924 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num, 1925 uint8_t *buf, int nb_sectors) 1926 { 1927 int async_ret; 1928 BlockDriverAIOCB *acb; 1929 struct iovec iov; 1930 QEMUIOVector qiov; 1931 1932 async_context_push(); 1933 1934 async_ret = NOT_DONE; 1935 iov.iov_base = (void *)buf; 1936 iov.iov_len = nb_sectors * 512; 1937 qemu_iovec_init_external(&qiov, &iov, 1); 1938 acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors, 1939 bdrv_rw_em_cb, &async_ret); 1940 if (acb == NULL) { 1941 async_ret = -1; 1942 goto fail; 1943 } 1944 1945 while (async_ret == NOT_DONE) { 1946 qemu_aio_wait(); 1947 } 1948 1949 1950 fail: 1951 async_context_pop(); 1952 return async_ret; 1953 } 1954 1955 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num, 1956 const uint8_t *buf, int nb_sectors) 1957 { 1958 int async_ret; 1959 BlockDriverAIOCB *acb; 1960 struct iovec iov; 1961 QEMUIOVector qiov; 1962 1963 async_context_push(); 1964 1965 async_ret = NOT_DONE; 1966 iov.iov_base = (void *)buf; 1967 iov.iov_len = nb_sectors * 512; 1968 qemu_iovec_init_external(&qiov, &iov, 1); 1969 acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors, 1970 bdrv_rw_em_cb, &async_ret); 1971 if (acb == NULL) { 1972 async_ret = -1; 1973 goto fail; 1974 } 1975 while (async_ret == NOT_DONE) { 1976 qemu_aio_wait(); 1977 } 1978 1979 fail: 1980 async_context_pop(); 1981 return async_ret; 1982 } 1983 1984 void bdrv_init(void) 1985 { 1986 module_call_init(MODULE_INIT_BLOCK); 1987 } 1988 1989 void bdrv_init_with_whitelist(void) 1990 { 1991 use_bdrv_whitelist = 1; 1992 bdrv_init(); 1993 } 1994 1995 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs, 1996 BlockDriverCompletionFunc *cb, void *opaque) 1997 { 1998 BlockDriverAIOCB *acb; 1999 2000 if (pool->free_aiocb) { 2001 acb = pool->free_aiocb; 2002 pool->free_aiocb = acb->next; 2003 } else { 2004 acb = qemu_mallocz(pool->aiocb_size); 2005 acb->pool = pool; 2006 } 2007 acb->bs = bs; 2008 acb->cb = cb; 2009 acb->opaque = opaque; 2010 return acb; 2011 } 2012 2013 void qemu_aio_release(void *p) 2014 { 2015 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p; 2016 AIOPool *pool = acb->pool; 2017 acb->next = pool->free_aiocb; 2018 pool->free_aiocb = acb; 2019 } 2020 2021 /**************************************************************/ 2022 /* removable device support */ 2023 2024 /** 2025 * Return TRUE if the media is present 2026 */ 2027 int bdrv_is_inserted(BlockDriverState *bs) 2028 { 2029 BlockDriver *drv = bs->drv; 2030 int ret; 2031 if (!drv) 2032 return 0; 2033 if (!drv->bdrv_is_inserted) 2034 return 1; 2035 ret = drv->bdrv_is_inserted(bs); 2036 return ret; 2037 } 2038 2039 /** 2040 * Return TRUE if the media changed since the last call to this 2041 * function. It is currently only used for floppy disks 2042 */ 2043 int bdrv_media_changed(BlockDriverState *bs) 2044 { 2045 BlockDriver *drv = bs->drv; 2046 int ret; 2047 2048 if (!drv || !drv->bdrv_media_changed) 2049 ret = -ENOTSUP; 2050 else 2051 ret = drv->bdrv_media_changed(bs); 2052 if (ret == -ENOTSUP) 2053 ret = bs->media_changed; 2054 bs->media_changed = 0; 2055 return ret; 2056 } 2057 2058 /** 2059 * If eject_flag is TRUE, eject the media. Otherwise, close the tray 2060 */ 2061 int bdrv_eject(BlockDriverState *bs, int eject_flag) 2062 { 2063 BlockDriver *drv = bs->drv; 2064 int ret; 2065 2066 if (bs->locked) { 2067 return -EBUSY; 2068 } 2069 2070 if (!drv || !drv->bdrv_eject) { 2071 ret = -ENOTSUP; 2072 } else { 2073 ret = drv->bdrv_eject(bs, eject_flag); 2074 } 2075 if (ret == -ENOTSUP) { 2076 if (eject_flag) 2077 bdrv_close(bs); 2078 ret = 0; 2079 } 2080 2081 return ret; 2082 } 2083 2084 int bdrv_is_locked(BlockDriverState *bs) 2085 { 2086 return bs->locked; 2087 } 2088 2089 /** 2090 * Lock or unlock the media (if it is locked, the user won't be able 2091 * to eject it manually). 2092 */ 2093 void bdrv_set_locked(BlockDriverState *bs, int locked) 2094 { 2095 BlockDriver *drv = bs->drv; 2096 2097 bs->locked = locked; 2098 if (drv && drv->bdrv_set_locked) { 2099 drv->bdrv_set_locked(bs, locked); 2100 } 2101 } 2102 2103 /* needed for generic scsi interface */ 2104 2105 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) 2106 { 2107 BlockDriver *drv = bs->drv; 2108 2109 if (drv && drv->bdrv_ioctl) 2110 return drv->bdrv_ioctl(bs, req, buf); 2111 return -ENOTSUP; 2112 } 2113 2114 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, 2115 unsigned long int req, void *buf, 2116 BlockDriverCompletionFunc *cb, void *opaque) 2117 { 2118 BlockDriver *drv = bs->drv; 2119 2120 if (drv && drv->bdrv_aio_ioctl) 2121 return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque); 2122 return NULL; 2123 } 2124 2125 2126 2127 void *qemu_blockalign(BlockDriverState *bs, size_t size) 2128 { 2129 return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size); 2130 } 2131 2132 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable) 2133 { 2134 int64_t bitmap_size; 2135 2136 if (enable) { 2137 if (!bs->dirty_bitmap) { 2138 bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) + 2139 BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1; 2140 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8; 2141 2142 bs->dirty_bitmap = qemu_mallocz(bitmap_size); 2143 } 2144 } else { 2145 if (bs->dirty_bitmap) { 2146 qemu_free(bs->dirty_bitmap); 2147 bs->dirty_bitmap = NULL; 2148 } 2149 } 2150 } 2151 2152 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector) 2153 { 2154 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK; 2155 2156 if (bs->dirty_bitmap && 2157 (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) { 2158 return bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] & 2159 (1 << (chunk % (sizeof(unsigned long) * 8))); 2160 } else { 2161 return 0; 2162 } 2163 } 2164 2165 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, 2166 int nr_sectors) 2167 { 2168 set_dirty_bitmap(bs, cur_sector, nr_sectors, 0); 2169 } 2170