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 "trace.h" 27 #include "monitor.h" 28 #include "block_int.h" 29 #include "blockjob.h" 30 #include "module.h" 31 #include "qjson.h" 32 #include "sysemu.h" 33 #include "notify.h" 34 #include "qemu-coroutine.h" 35 #include "qmp-commands.h" 36 #include "qemu-timer.h" 37 38 #ifdef CONFIG_BSD 39 #include <sys/types.h> 40 #include <sys/stat.h> 41 #include <sys/ioctl.h> 42 #include <sys/queue.h> 43 #ifndef __DragonFly__ 44 #include <sys/disk.h> 45 #endif 46 #endif 47 48 #ifdef _WIN32 49 #include <windows.h> 50 #endif 51 52 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ 53 54 typedef enum { 55 BDRV_REQ_COPY_ON_READ = 0x1, 56 BDRV_REQ_ZERO_WRITE = 0x2, 57 } BdrvRequestFlags; 58 59 static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load); 60 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, 61 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 62 BlockDriverCompletionFunc *cb, void *opaque); 63 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, 64 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 65 BlockDriverCompletionFunc *cb, void *opaque); 66 static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, 67 int64_t sector_num, int nb_sectors, 68 QEMUIOVector *iov); 69 static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, 70 int64_t sector_num, int nb_sectors, 71 QEMUIOVector *iov); 72 static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, 73 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, 74 BdrvRequestFlags flags); 75 static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, 76 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, 77 BdrvRequestFlags flags); 78 static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, 79 int64_t sector_num, 80 QEMUIOVector *qiov, 81 int nb_sectors, 82 BlockDriverCompletionFunc *cb, 83 void *opaque, 84 bool is_write); 85 static void coroutine_fn bdrv_co_do_rw(void *opaque); 86 static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, 87 int64_t sector_num, int nb_sectors); 88 89 static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors, 90 bool is_write, double elapsed_time, uint64_t *wait); 91 static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write, 92 double elapsed_time, uint64_t *wait); 93 static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors, 94 bool is_write, int64_t *wait); 95 96 static QTAILQ_HEAD(, BlockDriverState) bdrv_states = 97 QTAILQ_HEAD_INITIALIZER(bdrv_states); 98 99 static QLIST_HEAD(, BlockDriver) bdrv_drivers = 100 QLIST_HEAD_INITIALIZER(bdrv_drivers); 101 102 /* The device to use for VM snapshots */ 103 static BlockDriverState *bs_snapshots; 104 105 /* If non-zero, use only whitelisted block drivers */ 106 static int use_bdrv_whitelist; 107 108 #ifdef _WIN32 109 static int is_windows_drive_prefix(const char *filename) 110 { 111 return (((filename[0] >= 'a' && filename[0] <= 'z') || 112 (filename[0] >= 'A' && filename[0] <= 'Z')) && 113 filename[1] == ':'); 114 } 115 116 int is_windows_drive(const char *filename) 117 { 118 if (is_windows_drive_prefix(filename) && 119 filename[2] == '\0') 120 return 1; 121 if (strstart(filename, "\\\\.\\", NULL) || 122 strstart(filename, "//./", NULL)) 123 return 1; 124 return 0; 125 } 126 #endif 127 128 /* throttling disk I/O limits */ 129 void bdrv_io_limits_disable(BlockDriverState *bs) 130 { 131 bs->io_limits_enabled = false; 132 133 while (qemu_co_queue_next(&bs->throttled_reqs)); 134 135 if (bs->block_timer) { 136 qemu_del_timer(bs->block_timer); 137 qemu_free_timer(bs->block_timer); 138 bs->block_timer = NULL; 139 } 140 141 bs->slice_start = 0; 142 bs->slice_end = 0; 143 bs->slice_time = 0; 144 memset(&bs->io_base, 0, sizeof(bs->io_base)); 145 } 146 147 static void bdrv_block_timer(void *opaque) 148 { 149 BlockDriverState *bs = opaque; 150 151 qemu_co_queue_next(&bs->throttled_reqs); 152 } 153 154 void bdrv_io_limits_enable(BlockDriverState *bs) 155 { 156 qemu_co_queue_init(&bs->throttled_reqs); 157 bs->block_timer = qemu_new_timer_ns(vm_clock, bdrv_block_timer, bs); 158 bs->slice_time = 5 * BLOCK_IO_SLICE_TIME; 159 bs->slice_start = qemu_get_clock_ns(vm_clock); 160 bs->slice_end = bs->slice_start + bs->slice_time; 161 memset(&bs->io_base, 0, sizeof(bs->io_base)); 162 bs->io_limits_enabled = true; 163 } 164 165 bool bdrv_io_limits_enabled(BlockDriverState *bs) 166 { 167 BlockIOLimit *io_limits = &bs->io_limits; 168 return io_limits->bps[BLOCK_IO_LIMIT_READ] 169 || io_limits->bps[BLOCK_IO_LIMIT_WRITE] 170 || io_limits->bps[BLOCK_IO_LIMIT_TOTAL] 171 || io_limits->iops[BLOCK_IO_LIMIT_READ] 172 || io_limits->iops[BLOCK_IO_LIMIT_WRITE] 173 || io_limits->iops[BLOCK_IO_LIMIT_TOTAL]; 174 } 175 176 static void bdrv_io_limits_intercept(BlockDriverState *bs, 177 bool is_write, int nb_sectors) 178 { 179 int64_t wait_time = -1; 180 181 if (!qemu_co_queue_empty(&bs->throttled_reqs)) { 182 qemu_co_queue_wait(&bs->throttled_reqs); 183 } 184 185 /* In fact, we hope to keep each request's timing, in FIFO mode. The next 186 * throttled requests will not be dequeued until the current request is 187 * allowed to be serviced. So if the current request still exceeds the 188 * limits, it will be inserted to the head. All requests followed it will 189 * be still in throttled_reqs queue. 190 */ 191 192 while (bdrv_exceed_io_limits(bs, nb_sectors, is_write, &wait_time)) { 193 qemu_mod_timer(bs->block_timer, 194 wait_time + qemu_get_clock_ns(vm_clock)); 195 qemu_co_queue_wait_insert_head(&bs->throttled_reqs); 196 } 197 198 qemu_co_queue_next(&bs->throttled_reqs); 199 } 200 201 /* check if the path starts with "<protocol>:" */ 202 static int path_has_protocol(const char *path) 203 { 204 const char *p; 205 206 #ifdef _WIN32 207 if (is_windows_drive(path) || 208 is_windows_drive_prefix(path)) { 209 return 0; 210 } 211 p = path + strcspn(path, ":/\\"); 212 #else 213 p = path + strcspn(path, ":/"); 214 #endif 215 216 return *p == ':'; 217 } 218 219 int path_is_absolute(const char *path) 220 { 221 #ifdef _WIN32 222 /* specific case for names like: "\\.\d:" */ 223 if (is_windows_drive(path) || is_windows_drive_prefix(path)) { 224 return 1; 225 } 226 return (*path == '/' || *path == '\\'); 227 #else 228 return (*path == '/'); 229 #endif 230 } 231 232 /* if filename is absolute, just copy it to dest. Otherwise, build a 233 path to it by considering it is relative to base_path. URL are 234 supported. */ 235 void path_combine(char *dest, int dest_size, 236 const char *base_path, 237 const char *filename) 238 { 239 const char *p, *p1; 240 int len; 241 242 if (dest_size <= 0) 243 return; 244 if (path_is_absolute(filename)) { 245 pstrcpy(dest, dest_size, filename); 246 } else { 247 p = strchr(base_path, ':'); 248 if (p) 249 p++; 250 else 251 p = base_path; 252 p1 = strrchr(base_path, '/'); 253 #ifdef _WIN32 254 { 255 const char *p2; 256 p2 = strrchr(base_path, '\\'); 257 if (!p1 || p2 > p1) 258 p1 = p2; 259 } 260 #endif 261 if (p1) 262 p1++; 263 else 264 p1 = base_path; 265 if (p1 > p) 266 p = p1; 267 len = p - base_path; 268 if (len > dest_size - 1) 269 len = dest_size - 1; 270 memcpy(dest, base_path, len); 271 dest[len] = '\0'; 272 pstrcat(dest, dest_size, filename); 273 } 274 } 275 276 void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz) 277 { 278 if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) { 279 pstrcpy(dest, sz, bs->backing_file); 280 } else { 281 path_combine(dest, sz, bs->filename, bs->backing_file); 282 } 283 } 284 285 void bdrv_register(BlockDriver *bdrv) 286 { 287 /* Block drivers without coroutine functions need emulation */ 288 if (!bdrv->bdrv_co_readv) { 289 bdrv->bdrv_co_readv = bdrv_co_readv_em; 290 bdrv->bdrv_co_writev = bdrv_co_writev_em; 291 292 /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if 293 * the block driver lacks aio we need to emulate that too. 294 */ 295 if (!bdrv->bdrv_aio_readv) { 296 /* add AIO emulation layer */ 297 bdrv->bdrv_aio_readv = bdrv_aio_readv_em; 298 bdrv->bdrv_aio_writev = bdrv_aio_writev_em; 299 } 300 } 301 302 QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); 303 } 304 305 /* create a new block device (by default it is empty) */ 306 BlockDriverState *bdrv_new(const char *device_name) 307 { 308 BlockDriverState *bs; 309 310 bs = g_malloc0(sizeof(BlockDriverState)); 311 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name); 312 if (device_name[0] != '\0') { 313 QTAILQ_INSERT_TAIL(&bdrv_states, bs, list); 314 } 315 bdrv_iostatus_disable(bs); 316 notifier_list_init(&bs->close_notifiers); 317 318 return bs; 319 } 320 321 void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify) 322 { 323 notifier_list_add(&bs->close_notifiers, notify); 324 } 325 326 BlockDriver *bdrv_find_format(const char *format_name) 327 { 328 BlockDriver *drv1; 329 QLIST_FOREACH(drv1, &bdrv_drivers, list) { 330 if (!strcmp(drv1->format_name, format_name)) { 331 return drv1; 332 } 333 } 334 return NULL; 335 } 336 337 static int bdrv_is_whitelisted(BlockDriver *drv) 338 { 339 static const char *whitelist[] = { 340 CONFIG_BDRV_WHITELIST 341 }; 342 const char **p; 343 344 if (!whitelist[0]) 345 return 1; /* no whitelist, anything goes */ 346 347 for (p = whitelist; *p; p++) { 348 if (!strcmp(drv->format_name, *p)) { 349 return 1; 350 } 351 } 352 return 0; 353 } 354 355 BlockDriver *bdrv_find_whitelisted_format(const char *format_name) 356 { 357 BlockDriver *drv = bdrv_find_format(format_name); 358 return drv && bdrv_is_whitelisted(drv) ? drv : NULL; 359 } 360 361 typedef struct CreateCo { 362 BlockDriver *drv; 363 char *filename; 364 QEMUOptionParameter *options; 365 int ret; 366 } CreateCo; 367 368 static void coroutine_fn bdrv_create_co_entry(void *opaque) 369 { 370 CreateCo *cco = opaque; 371 assert(cco->drv); 372 373 cco->ret = cco->drv->bdrv_create(cco->filename, cco->options); 374 } 375 376 int bdrv_create(BlockDriver *drv, const char* filename, 377 QEMUOptionParameter *options) 378 { 379 int ret; 380 381 Coroutine *co; 382 CreateCo cco = { 383 .drv = drv, 384 .filename = g_strdup(filename), 385 .options = options, 386 .ret = NOT_DONE, 387 }; 388 389 if (!drv->bdrv_create) { 390 return -ENOTSUP; 391 } 392 393 if (qemu_in_coroutine()) { 394 /* Fast-path if already in coroutine context */ 395 bdrv_create_co_entry(&cco); 396 } else { 397 co = qemu_coroutine_create(bdrv_create_co_entry); 398 qemu_coroutine_enter(co, &cco); 399 while (cco.ret == NOT_DONE) { 400 qemu_aio_wait(); 401 } 402 } 403 404 ret = cco.ret; 405 g_free(cco.filename); 406 407 return ret; 408 } 409 410 int bdrv_create_file(const char* filename, QEMUOptionParameter *options) 411 { 412 BlockDriver *drv; 413 414 drv = bdrv_find_protocol(filename); 415 if (drv == NULL) { 416 return -ENOENT; 417 } 418 419 return bdrv_create(drv, filename, options); 420 } 421 422 /* 423 * Create a uniquely-named empty temporary file. 424 * Return 0 upon success, otherwise a negative errno value. 425 */ 426 int get_tmp_filename(char *filename, int size) 427 { 428 #ifdef _WIN32 429 char temp_dir[MAX_PATH]; 430 /* GetTempFileName requires that its output buffer (4th param) 431 have length MAX_PATH or greater. */ 432 assert(size >= MAX_PATH); 433 return (GetTempPath(MAX_PATH, temp_dir) 434 && GetTempFileName(temp_dir, "qem", 0, filename) 435 ? 0 : -GetLastError()); 436 #else 437 int fd; 438 const char *tmpdir; 439 tmpdir = getenv("TMPDIR"); 440 if (!tmpdir) 441 tmpdir = "/tmp"; 442 if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) { 443 return -EOVERFLOW; 444 } 445 fd = mkstemp(filename); 446 if (fd < 0) { 447 return -errno; 448 } 449 if (close(fd) != 0) { 450 unlink(filename); 451 return -errno; 452 } 453 return 0; 454 #endif 455 } 456 457 /* 458 * Detect host devices. By convention, /dev/cdrom[N] is always 459 * recognized as a host CDROM. 460 */ 461 static BlockDriver *find_hdev_driver(const char *filename) 462 { 463 int score_max = 0, score; 464 BlockDriver *drv = NULL, *d; 465 466 QLIST_FOREACH(d, &bdrv_drivers, list) { 467 if (d->bdrv_probe_device) { 468 score = d->bdrv_probe_device(filename); 469 if (score > score_max) { 470 score_max = score; 471 drv = d; 472 } 473 } 474 } 475 476 return drv; 477 } 478 479 BlockDriver *bdrv_find_protocol(const char *filename) 480 { 481 BlockDriver *drv1; 482 char protocol[128]; 483 int len; 484 const char *p; 485 486 /* TODO Drivers without bdrv_file_open must be specified explicitly */ 487 488 /* 489 * XXX(hch): we really should not let host device detection 490 * override an explicit protocol specification, but moving this 491 * later breaks access to device names with colons in them. 492 * Thanks to the brain-dead persistent naming schemes on udev- 493 * based Linux systems those actually are quite common. 494 */ 495 drv1 = find_hdev_driver(filename); 496 if (drv1) { 497 return drv1; 498 } 499 500 if (!path_has_protocol(filename)) { 501 return bdrv_find_format("file"); 502 } 503 p = strchr(filename, ':'); 504 assert(p != NULL); 505 len = p - filename; 506 if (len > sizeof(protocol) - 1) 507 len = sizeof(protocol) - 1; 508 memcpy(protocol, filename, len); 509 protocol[len] = '\0'; 510 QLIST_FOREACH(drv1, &bdrv_drivers, list) { 511 if (drv1->protocol_name && 512 !strcmp(drv1->protocol_name, protocol)) { 513 return drv1; 514 } 515 } 516 return NULL; 517 } 518 519 static int find_image_format(const char *filename, BlockDriver **pdrv) 520 { 521 int ret, score, score_max; 522 BlockDriver *drv1, *drv; 523 uint8_t buf[2048]; 524 BlockDriverState *bs; 525 526 ret = bdrv_file_open(&bs, filename, 0); 527 if (ret < 0) { 528 *pdrv = NULL; 529 return ret; 530 } 531 532 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ 533 if (bs->sg || !bdrv_is_inserted(bs)) { 534 bdrv_delete(bs); 535 drv = bdrv_find_format("raw"); 536 if (!drv) { 537 ret = -ENOENT; 538 } 539 *pdrv = drv; 540 return ret; 541 } 542 543 ret = bdrv_pread(bs, 0, buf, sizeof(buf)); 544 bdrv_delete(bs); 545 if (ret < 0) { 546 *pdrv = NULL; 547 return ret; 548 } 549 550 score_max = 0; 551 drv = NULL; 552 QLIST_FOREACH(drv1, &bdrv_drivers, list) { 553 if (drv1->bdrv_probe) { 554 score = drv1->bdrv_probe(buf, ret, filename); 555 if (score > score_max) { 556 score_max = score; 557 drv = drv1; 558 } 559 } 560 } 561 if (!drv) { 562 ret = -ENOENT; 563 } 564 *pdrv = drv; 565 return ret; 566 } 567 568 /** 569 * Set the current 'total_sectors' value 570 */ 571 static int refresh_total_sectors(BlockDriverState *bs, int64_t hint) 572 { 573 BlockDriver *drv = bs->drv; 574 575 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */ 576 if (bs->sg) 577 return 0; 578 579 /* query actual device if possible, otherwise just trust the hint */ 580 if (drv->bdrv_getlength) { 581 int64_t length = drv->bdrv_getlength(bs); 582 if (length < 0) { 583 return length; 584 } 585 hint = length >> BDRV_SECTOR_BITS; 586 } 587 588 bs->total_sectors = hint; 589 return 0; 590 } 591 592 /** 593 * Set open flags for a given cache mode 594 * 595 * Return 0 on success, -1 if the cache mode was invalid. 596 */ 597 int bdrv_parse_cache_flags(const char *mode, int *flags) 598 { 599 *flags &= ~BDRV_O_CACHE_MASK; 600 601 if (!strcmp(mode, "off") || !strcmp(mode, "none")) { 602 *flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; 603 } else if (!strcmp(mode, "directsync")) { 604 *flags |= BDRV_O_NOCACHE; 605 } else if (!strcmp(mode, "writeback")) { 606 *flags |= BDRV_O_CACHE_WB; 607 } else if (!strcmp(mode, "unsafe")) { 608 *flags |= BDRV_O_CACHE_WB; 609 *flags |= BDRV_O_NO_FLUSH; 610 } else if (!strcmp(mode, "writethrough")) { 611 /* this is the default */ 612 } else { 613 return -1; 614 } 615 616 return 0; 617 } 618 619 /** 620 * The copy-on-read flag is actually a reference count so multiple users may 621 * use the feature without worrying about clobbering its previous state. 622 * Copy-on-read stays enabled until all users have called to disable it. 623 */ 624 void bdrv_enable_copy_on_read(BlockDriverState *bs) 625 { 626 bs->copy_on_read++; 627 } 628 629 void bdrv_disable_copy_on_read(BlockDriverState *bs) 630 { 631 assert(bs->copy_on_read > 0); 632 bs->copy_on_read--; 633 } 634 635 /* 636 * Common part for opening disk images and files 637 */ 638 static int bdrv_open_common(BlockDriverState *bs, const char *filename, 639 int flags, BlockDriver *drv) 640 { 641 int ret, open_flags; 642 643 assert(drv != NULL); 644 assert(bs->file == NULL); 645 646 trace_bdrv_open_common(bs, filename, flags, drv->format_name); 647 648 bs->open_flags = flags; 649 bs->buffer_alignment = 512; 650 651 assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */ 652 if ((flags & BDRV_O_RDWR) && (flags & BDRV_O_COPY_ON_READ)) { 653 bdrv_enable_copy_on_read(bs); 654 } 655 656 pstrcpy(bs->filename, sizeof(bs->filename), filename); 657 658 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv)) { 659 return -ENOTSUP; 660 } 661 662 bs->drv = drv; 663 bs->opaque = g_malloc0(drv->instance_size); 664 665 bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB); 666 open_flags = flags | BDRV_O_CACHE_WB; 667 668 /* 669 * Clear flags that are internal to the block layer before opening the 670 * image. 671 */ 672 open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); 673 674 /* 675 * Snapshots should be writable. 676 */ 677 if (bs->is_temporary) { 678 open_flags |= BDRV_O_RDWR; 679 } 680 681 bs->read_only = !(open_flags & BDRV_O_RDWR); 682 683 /* Open the image, either directly or using a protocol */ 684 if (drv->bdrv_file_open) { 685 ret = drv->bdrv_file_open(bs, filename, open_flags); 686 } else { 687 ret = bdrv_file_open(&bs->file, filename, open_flags); 688 if (ret >= 0) { 689 ret = drv->bdrv_open(bs, open_flags); 690 } 691 } 692 693 if (ret < 0) { 694 goto free_and_fail; 695 } 696 697 ret = refresh_total_sectors(bs, bs->total_sectors); 698 if (ret < 0) { 699 goto free_and_fail; 700 } 701 702 #ifndef _WIN32 703 if (bs->is_temporary) { 704 unlink(filename); 705 } 706 #endif 707 return 0; 708 709 free_and_fail: 710 if (bs->file) { 711 bdrv_delete(bs->file); 712 bs->file = NULL; 713 } 714 g_free(bs->opaque); 715 bs->opaque = NULL; 716 bs->drv = NULL; 717 return ret; 718 } 719 720 /* 721 * Opens a file using a protocol (file, host_device, nbd, ...) 722 */ 723 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags) 724 { 725 BlockDriverState *bs; 726 BlockDriver *drv; 727 int ret; 728 729 drv = bdrv_find_protocol(filename); 730 if (!drv) { 731 return -ENOENT; 732 } 733 734 bs = bdrv_new(""); 735 ret = bdrv_open_common(bs, filename, flags, drv); 736 if (ret < 0) { 737 bdrv_delete(bs); 738 return ret; 739 } 740 bs->growable = 1; 741 *pbs = bs; 742 return 0; 743 } 744 745 /* 746 * Opens a disk image (raw, qcow2, vmdk, ...) 747 */ 748 int bdrv_open(BlockDriverState *bs, const char *filename, int flags, 749 BlockDriver *drv) 750 { 751 int ret; 752 char tmp_filename[PATH_MAX]; 753 754 if (flags & BDRV_O_SNAPSHOT) { 755 BlockDriverState *bs1; 756 int64_t total_size; 757 int is_protocol = 0; 758 BlockDriver *bdrv_qcow2; 759 QEMUOptionParameter *options; 760 char backing_filename[PATH_MAX]; 761 762 /* if snapshot, we create a temporary backing file and open it 763 instead of opening 'filename' directly */ 764 765 /* if there is a backing file, use it */ 766 bs1 = bdrv_new(""); 767 ret = bdrv_open(bs1, filename, 0, drv); 768 if (ret < 0) { 769 bdrv_delete(bs1); 770 return ret; 771 } 772 total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK; 773 774 if (bs1->drv && bs1->drv->protocol_name) 775 is_protocol = 1; 776 777 bdrv_delete(bs1); 778 779 ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename)); 780 if (ret < 0) { 781 return ret; 782 } 783 784 /* Real path is meaningless for protocols */ 785 if (is_protocol) 786 snprintf(backing_filename, sizeof(backing_filename), 787 "%s", filename); 788 else if (!realpath(filename, backing_filename)) 789 return -errno; 790 791 bdrv_qcow2 = bdrv_find_format("qcow2"); 792 options = parse_option_parameters("", bdrv_qcow2->create_options, NULL); 793 794 set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size); 795 set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename); 796 if (drv) { 797 set_option_parameter(options, BLOCK_OPT_BACKING_FMT, 798 drv->format_name); 799 } 800 801 ret = bdrv_create(bdrv_qcow2, tmp_filename, options); 802 free_option_parameters(options); 803 if (ret < 0) { 804 return ret; 805 } 806 807 filename = tmp_filename; 808 drv = bdrv_qcow2; 809 bs->is_temporary = 1; 810 } 811 812 /* Find the right image format driver */ 813 if (!drv) { 814 ret = find_image_format(filename, &drv); 815 } 816 817 if (!drv) { 818 goto unlink_and_fail; 819 } 820 821 if (flags & BDRV_O_RDWR) { 822 flags |= BDRV_O_ALLOW_RDWR; 823 } 824 825 /* Open the image */ 826 ret = bdrv_open_common(bs, filename, flags, drv); 827 if (ret < 0) { 828 goto unlink_and_fail; 829 } 830 831 /* If there is a backing file, use it */ 832 if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') { 833 char backing_filename[PATH_MAX]; 834 int back_flags; 835 BlockDriver *back_drv = NULL; 836 837 bs->backing_hd = bdrv_new(""); 838 bdrv_get_full_backing_filename(bs, backing_filename, 839 sizeof(backing_filename)); 840 841 if (bs->backing_format[0] != '\0') { 842 back_drv = bdrv_find_format(bs->backing_format); 843 } 844 845 /* backing files always opened read-only */ 846 back_flags = 847 flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); 848 849 ret = bdrv_open(bs->backing_hd, backing_filename, back_flags, back_drv); 850 if (ret < 0) { 851 bdrv_close(bs); 852 return ret; 853 } 854 } 855 856 if (!bdrv_key_required(bs)) { 857 bdrv_dev_change_media_cb(bs, true); 858 } 859 860 /* throttling disk I/O limits */ 861 if (bs->io_limits_enabled) { 862 bdrv_io_limits_enable(bs); 863 } 864 865 return 0; 866 867 unlink_and_fail: 868 if (bs->is_temporary) { 869 unlink(filename); 870 } 871 return ret; 872 } 873 874 typedef struct BlockReopenQueueEntry { 875 bool prepared; 876 BDRVReopenState state; 877 QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; 878 } BlockReopenQueueEntry; 879 880 /* 881 * Adds a BlockDriverState to a simple queue for an atomic, transactional 882 * reopen of multiple devices. 883 * 884 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT 885 * already performed, or alternatively may be NULL a new BlockReopenQueue will 886 * be created and initialized. This newly created BlockReopenQueue should be 887 * passed back in for subsequent calls that are intended to be of the same 888 * atomic 'set'. 889 * 890 * bs is the BlockDriverState to add to the reopen queue. 891 * 892 * flags contains the open flags for the associated bs 893 * 894 * returns a pointer to bs_queue, which is either the newly allocated 895 * bs_queue, or the existing bs_queue being used. 896 * 897 */ 898 BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, 899 BlockDriverState *bs, int flags) 900 { 901 assert(bs != NULL); 902 903 BlockReopenQueueEntry *bs_entry; 904 if (bs_queue == NULL) { 905 bs_queue = g_new0(BlockReopenQueue, 1); 906 QSIMPLEQ_INIT(bs_queue); 907 } 908 909 if (bs->file) { 910 bdrv_reopen_queue(bs_queue, bs->file, flags); 911 } 912 913 bs_entry = g_new0(BlockReopenQueueEntry, 1); 914 QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); 915 916 bs_entry->state.bs = bs; 917 bs_entry->state.flags = flags; 918 919 return bs_queue; 920 } 921 922 /* 923 * Reopen multiple BlockDriverStates atomically & transactionally. 924 * 925 * The queue passed in (bs_queue) must have been built up previous 926 * via bdrv_reopen_queue(). 927 * 928 * Reopens all BDS specified in the queue, with the appropriate 929 * flags. All devices are prepared for reopen, and failure of any 930 * device will cause all device changes to be abandonded, and intermediate 931 * data cleaned up. 932 * 933 * If all devices prepare successfully, then the changes are committed 934 * to all devices. 935 * 936 */ 937 int bdrv_reopen_multiple(BlockReopenQueue *bs_queue, Error **errp) 938 { 939 int ret = -1; 940 BlockReopenQueueEntry *bs_entry, *next; 941 Error *local_err = NULL; 942 943 assert(bs_queue != NULL); 944 945 bdrv_drain_all(); 946 947 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { 948 if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) { 949 error_propagate(errp, local_err); 950 goto cleanup; 951 } 952 bs_entry->prepared = true; 953 } 954 955 /* If we reach this point, we have success and just need to apply the 956 * changes 957 */ 958 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { 959 bdrv_reopen_commit(&bs_entry->state); 960 } 961 962 ret = 0; 963 964 cleanup: 965 QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { 966 if (ret && bs_entry->prepared) { 967 bdrv_reopen_abort(&bs_entry->state); 968 } 969 g_free(bs_entry); 970 } 971 g_free(bs_queue); 972 return ret; 973 } 974 975 976 /* Reopen a single BlockDriverState with the specified flags. */ 977 int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp) 978 { 979 int ret = -1; 980 Error *local_err = NULL; 981 BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, bdrv_flags); 982 983 ret = bdrv_reopen_multiple(queue, &local_err); 984 if (local_err != NULL) { 985 error_propagate(errp, local_err); 986 } 987 return ret; 988 } 989 990 991 /* 992 * Prepares a BlockDriverState for reopen. All changes are staged in the 993 * 'opaque' field of the BDRVReopenState, which is used and allocated by 994 * the block driver layer .bdrv_reopen_prepare() 995 * 996 * bs is the BlockDriverState to reopen 997 * flags are the new open flags 998 * queue is the reopen queue 999 * 1000 * Returns 0 on success, non-zero on error. On error errp will be set 1001 * as well. 1002 * 1003 * On failure, bdrv_reopen_abort() will be called to clean up any data. 1004 * It is the responsibility of the caller to then call the abort() or 1005 * commit() for any other BDS that have been left in a prepare() state 1006 * 1007 */ 1008 int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, 1009 Error **errp) 1010 { 1011 int ret = -1; 1012 Error *local_err = NULL; 1013 BlockDriver *drv; 1014 1015 assert(reopen_state != NULL); 1016 assert(reopen_state->bs->drv != NULL); 1017 drv = reopen_state->bs->drv; 1018 1019 /* if we are to stay read-only, do not allow permission change 1020 * to r/w */ 1021 if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) && 1022 reopen_state->flags & BDRV_O_RDWR) { 1023 error_set(errp, QERR_DEVICE_IS_READ_ONLY, 1024 reopen_state->bs->device_name); 1025 goto error; 1026 } 1027 1028 1029 ret = bdrv_flush(reopen_state->bs); 1030 if (ret) { 1031 error_set(errp, ERROR_CLASS_GENERIC_ERROR, "Error (%s) flushing drive", 1032 strerror(-ret)); 1033 goto error; 1034 } 1035 1036 if (drv->bdrv_reopen_prepare) { 1037 ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); 1038 if (ret) { 1039 if (local_err != NULL) { 1040 error_propagate(errp, local_err); 1041 } else { 1042 error_set(errp, QERR_OPEN_FILE_FAILED, 1043 reopen_state->bs->filename); 1044 } 1045 goto error; 1046 } 1047 } else { 1048 /* It is currently mandatory to have a bdrv_reopen_prepare() 1049 * handler for each supported drv. */ 1050 error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, 1051 drv->format_name, reopen_state->bs->device_name, 1052 "reopening of file"); 1053 ret = -1; 1054 goto error; 1055 } 1056 1057 ret = 0; 1058 1059 error: 1060 return ret; 1061 } 1062 1063 /* 1064 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and 1065 * makes them final by swapping the staging BlockDriverState contents into 1066 * the active BlockDriverState contents. 1067 */ 1068 void bdrv_reopen_commit(BDRVReopenState *reopen_state) 1069 { 1070 BlockDriver *drv; 1071 1072 assert(reopen_state != NULL); 1073 drv = reopen_state->bs->drv; 1074 assert(drv != NULL); 1075 1076 /* If there are any driver level actions to take */ 1077 if (drv->bdrv_reopen_commit) { 1078 drv->bdrv_reopen_commit(reopen_state); 1079 } 1080 1081 /* set BDS specific flags now */ 1082 reopen_state->bs->open_flags = reopen_state->flags; 1083 reopen_state->bs->enable_write_cache = !!(reopen_state->flags & 1084 BDRV_O_CACHE_WB); 1085 reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); 1086 } 1087 1088 /* 1089 * Abort the reopen, and delete and free the staged changes in 1090 * reopen_state 1091 */ 1092 void bdrv_reopen_abort(BDRVReopenState *reopen_state) 1093 { 1094 BlockDriver *drv; 1095 1096 assert(reopen_state != NULL); 1097 drv = reopen_state->bs->drv; 1098 assert(drv != NULL); 1099 1100 if (drv->bdrv_reopen_abort) { 1101 drv->bdrv_reopen_abort(reopen_state); 1102 } 1103 } 1104 1105 1106 void bdrv_close(BlockDriverState *bs) 1107 { 1108 bdrv_flush(bs); 1109 if (bs->job) { 1110 block_job_cancel_sync(bs->job); 1111 } 1112 bdrv_drain_all(); 1113 notifier_list_notify(&bs->close_notifiers, bs); 1114 1115 if (bs->drv) { 1116 if (bs == bs_snapshots) { 1117 bs_snapshots = NULL; 1118 } 1119 if (bs->backing_hd) { 1120 bdrv_delete(bs->backing_hd); 1121 bs->backing_hd = NULL; 1122 } 1123 bs->drv->bdrv_close(bs); 1124 g_free(bs->opaque); 1125 #ifdef _WIN32 1126 if (bs->is_temporary) { 1127 unlink(bs->filename); 1128 } 1129 #endif 1130 bs->opaque = NULL; 1131 bs->drv = NULL; 1132 bs->copy_on_read = 0; 1133 bs->backing_file[0] = '\0'; 1134 bs->backing_format[0] = '\0'; 1135 bs->total_sectors = 0; 1136 bs->encrypted = 0; 1137 bs->valid_key = 0; 1138 bs->sg = 0; 1139 bs->growable = 0; 1140 1141 if (bs->file != NULL) { 1142 bdrv_delete(bs->file); 1143 bs->file = NULL; 1144 } 1145 } 1146 1147 bdrv_dev_change_media_cb(bs, false); 1148 1149 /*throttling disk I/O limits*/ 1150 if (bs->io_limits_enabled) { 1151 bdrv_io_limits_disable(bs); 1152 } 1153 } 1154 1155 void bdrv_close_all(void) 1156 { 1157 BlockDriverState *bs; 1158 1159 QTAILQ_FOREACH(bs, &bdrv_states, list) { 1160 bdrv_close(bs); 1161 } 1162 } 1163 1164 /* 1165 * Wait for pending requests to complete across all BlockDriverStates 1166 * 1167 * This function does not flush data to disk, use bdrv_flush_all() for that 1168 * after calling this function. 1169 * 1170 * Note that completion of an asynchronous I/O operation can trigger any 1171 * number of other I/O operations on other devices---for example a coroutine 1172 * can be arbitrarily complex and a constant flow of I/O can come until the 1173 * coroutine is complete. Because of this, it is not possible to have a 1174 * function to drain a single device's I/O queue. 1175 */ 1176 void bdrv_drain_all(void) 1177 { 1178 BlockDriverState *bs; 1179 bool busy; 1180 1181 do { 1182 busy = qemu_aio_wait(); 1183 1184 /* FIXME: We do not have timer support here, so this is effectively 1185 * a busy wait. 1186 */ 1187 QTAILQ_FOREACH(bs, &bdrv_states, list) { 1188 if (!qemu_co_queue_empty(&bs->throttled_reqs)) { 1189 qemu_co_queue_restart_all(&bs->throttled_reqs); 1190 busy = true; 1191 } 1192 } 1193 } while (busy); 1194 1195 /* If requests are still pending there is a bug somewhere */ 1196 QTAILQ_FOREACH(bs, &bdrv_states, list) { 1197 assert(QLIST_EMPTY(&bs->tracked_requests)); 1198 assert(qemu_co_queue_empty(&bs->throttled_reqs)); 1199 } 1200 } 1201 1202 /* make a BlockDriverState anonymous by removing from bdrv_state list. 1203 Also, NULL terminate the device_name to prevent double remove */ 1204 void bdrv_make_anon(BlockDriverState *bs) 1205 { 1206 if (bs->device_name[0] != '\0') { 1207 QTAILQ_REMOVE(&bdrv_states, bs, list); 1208 } 1209 bs->device_name[0] = '\0'; 1210 } 1211 1212 static void bdrv_rebind(BlockDriverState *bs) 1213 { 1214 if (bs->drv && bs->drv->bdrv_rebind) { 1215 bs->drv->bdrv_rebind(bs); 1216 } 1217 } 1218 1219 static void bdrv_move_feature_fields(BlockDriverState *bs_dest, 1220 BlockDriverState *bs_src) 1221 { 1222 /* move some fields that need to stay attached to the device */ 1223 bs_dest->open_flags = bs_src->open_flags; 1224 1225 /* dev info */ 1226 bs_dest->dev_ops = bs_src->dev_ops; 1227 bs_dest->dev_opaque = bs_src->dev_opaque; 1228 bs_dest->dev = bs_src->dev; 1229 bs_dest->buffer_alignment = bs_src->buffer_alignment; 1230 bs_dest->copy_on_read = bs_src->copy_on_read; 1231 1232 bs_dest->enable_write_cache = bs_src->enable_write_cache; 1233 1234 /* i/o timing parameters */ 1235 bs_dest->slice_time = bs_src->slice_time; 1236 bs_dest->slice_start = bs_src->slice_start; 1237 bs_dest->slice_end = bs_src->slice_end; 1238 bs_dest->io_limits = bs_src->io_limits; 1239 bs_dest->io_base = bs_src->io_base; 1240 bs_dest->throttled_reqs = bs_src->throttled_reqs; 1241 bs_dest->block_timer = bs_src->block_timer; 1242 bs_dest->io_limits_enabled = bs_src->io_limits_enabled; 1243 1244 /* r/w error */ 1245 bs_dest->on_read_error = bs_src->on_read_error; 1246 bs_dest->on_write_error = bs_src->on_write_error; 1247 1248 /* i/o status */ 1249 bs_dest->iostatus_enabled = bs_src->iostatus_enabled; 1250 bs_dest->iostatus = bs_src->iostatus; 1251 1252 /* dirty bitmap */ 1253 bs_dest->dirty_count = bs_src->dirty_count; 1254 bs_dest->dirty_bitmap = bs_src->dirty_bitmap; 1255 1256 /* job */ 1257 bs_dest->in_use = bs_src->in_use; 1258 bs_dest->job = bs_src->job; 1259 1260 /* keep the same entry in bdrv_states */ 1261 pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name), 1262 bs_src->device_name); 1263 bs_dest->list = bs_src->list; 1264 } 1265 1266 /* 1267 * Swap bs contents for two image chains while they are live, 1268 * while keeping required fields on the BlockDriverState that is 1269 * actually attached to a device. 1270 * 1271 * This will modify the BlockDriverState fields, and swap contents 1272 * between bs_new and bs_old. Both bs_new and bs_old are modified. 1273 * 1274 * bs_new is required to be anonymous. 1275 * 1276 * This function does not create any image files. 1277 */ 1278 void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) 1279 { 1280 BlockDriverState tmp; 1281 1282 /* bs_new must be anonymous and shouldn't have anything fancy enabled */ 1283 assert(bs_new->device_name[0] == '\0'); 1284 assert(bs_new->dirty_bitmap == NULL); 1285 assert(bs_new->job == NULL); 1286 assert(bs_new->dev == NULL); 1287 assert(bs_new->in_use == 0); 1288 assert(bs_new->io_limits_enabled == false); 1289 assert(bs_new->block_timer == NULL); 1290 1291 tmp = *bs_new; 1292 *bs_new = *bs_old; 1293 *bs_old = tmp; 1294 1295 /* there are some fields that should not be swapped, move them back */ 1296 bdrv_move_feature_fields(&tmp, bs_old); 1297 bdrv_move_feature_fields(bs_old, bs_new); 1298 bdrv_move_feature_fields(bs_new, &tmp); 1299 1300 /* bs_new shouldn't be in bdrv_states even after the swap! */ 1301 assert(bs_new->device_name[0] == '\0'); 1302 1303 /* Check a few fields that should remain attached to the device */ 1304 assert(bs_new->dev == NULL); 1305 assert(bs_new->job == NULL); 1306 assert(bs_new->in_use == 0); 1307 assert(bs_new->io_limits_enabled == false); 1308 assert(bs_new->block_timer == NULL); 1309 1310 bdrv_rebind(bs_new); 1311 bdrv_rebind(bs_old); 1312 } 1313 1314 /* 1315 * Add new bs contents at the top of an image chain while the chain is 1316 * live, while keeping required fields on the top layer. 1317 * 1318 * This will modify the BlockDriverState fields, and swap contents 1319 * between bs_new and bs_top. Both bs_new and bs_top are modified. 1320 * 1321 * bs_new is required to be anonymous. 1322 * 1323 * This function does not create any image files. 1324 */ 1325 void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) 1326 { 1327 bdrv_swap(bs_new, bs_top); 1328 1329 /* The contents of 'tmp' will become bs_top, as we are 1330 * swapping bs_new and bs_top contents. */ 1331 bs_top->backing_hd = bs_new; 1332 bs_top->open_flags &= ~BDRV_O_NO_BACKING; 1333 pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file), 1334 bs_new->filename); 1335 pstrcpy(bs_top->backing_format, sizeof(bs_top->backing_format), 1336 bs_new->drv ? bs_new->drv->format_name : ""); 1337 } 1338 1339 void bdrv_delete(BlockDriverState *bs) 1340 { 1341 assert(!bs->dev); 1342 assert(!bs->job); 1343 assert(!bs->in_use); 1344 1345 /* remove from list, if necessary */ 1346 bdrv_make_anon(bs); 1347 1348 bdrv_close(bs); 1349 1350 assert(bs != bs_snapshots); 1351 g_free(bs); 1352 } 1353 1354 int bdrv_attach_dev(BlockDriverState *bs, void *dev) 1355 /* TODO change to DeviceState *dev when all users are qdevified */ 1356 { 1357 if (bs->dev) { 1358 return -EBUSY; 1359 } 1360 bs->dev = dev; 1361 bdrv_iostatus_reset(bs); 1362 return 0; 1363 } 1364 1365 /* TODO qdevified devices don't use this, remove when devices are qdevified */ 1366 void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev) 1367 { 1368 if (bdrv_attach_dev(bs, dev) < 0) { 1369 abort(); 1370 } 1371 } 1372 1373 void bdrv_detach_dev(BlockDriverState *bs, void *dev) 1374 /* TODO change to DeviceState *dev when all users are qdevified */ 1375 { 1376 assert(bs->dev == dev); 1377 bs->dev = NULL; 1378 bs->dev_ops = NULL; 1379 bs->dev_opaque = NULL; 1380 bs->buffer_alignment = 512; 1381 } 1382 1383 /* TODO change to return DeviceState * when all users are qdevified */ 1384 void *bdrv_get_attached_dev(BlockDriverState *bs) 1385 { 1386 return bs->dev; 1387 } 1388 1389 void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops, 1390 void *opaque) 1391 { 1392 bs->dev_ops = ops; 1393 bs->dev_opaque = opaque; 1394 if (bdrv_dev_has_removable_media(bs) && bs == bs_snapshots) { 1395 bs_snapshots = NULL; 1396 } 1397 } 1398 1399 void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, 1400 enum MonitorEvent ev, 1401 BlockErrorAction action, bool is_read) 1402 { 1403 QObject *data; 1404 const char *action_str; 1405 1406 switch (action) { 1407 case BDRV_ACTION_REPORT: 1408 action_str = "report"; 1409 break; 1410 case BDRV_ACTION_IGNORE: 1411 action_str = "ignore"; 1412 break; 1413 case BDRV_ACTION_STOP: 1414 action_str = "stop"; 1415 break; 1416 default: 1417 abort(); 1418 } 1419 1420 data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }", 1421 bdrv->device_name, 1422 action_str, 1423 is_read ? "read" : "write"); 1424 monitor_protocol_event(ev, data); 1425 1426 qobject_decref(data); 1427 } 1428 1429 static void bdrv_emit_qmp_eject_event(BlockDriverState *bs, bool ejected) 1430 { 1431 QObject *data; 1432 1433 data = qobject_from_jsonf("{ 'device': %s, 'tray-open': %i }", 1434 bdrv_get_device_name(bs), ejected); 1435 monitor_protocol_event(QEVENT_DEVICE_TRAY_MOVED, data); 1436 1437 qobject_decref(data); 1438 } 1439 1440 static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load) 1441 { 1442 if (bs->dev_ops && bs->dev_ops->change_media_cb) { 1443 bool tray_was_closed = !bdrv_dev_is_tray_open(bs); 1444 bs->dev_ops->change_media_cb(bs->dev_opaque, load); 1445 if (tray_was_closed) { 1446 /* tray open */ 1447 bdrv_emit_qmp_eject_event(bs, true); 1448 } 1449 if (load) { 1450 /* tray close */ 1451 bdrv_emit_qmp_eject_event(bs, false); 1452 } 1453 } 1454 } 1455 1456 bool bdrv_dev_has_removable_media(BlockDriverState *bs) 1457 { 1458 return !bs->dev || (bs->dev_ops && bs->dev_ops->change_media_cb); 1459 } 1460 1461 void bdrv_dev_eject_request(BlockDriverState *bs, bool force) 1462 { 1463 if (bs->dev_ops && bs->dev_ops->eject_request_cb) { 1464 bs->dev_ops->eject_request_cb(bs->dev_opaque, force); 1465 } 1466 } 1467 1468 bool bdrv_dev_is_tray_open(BlockDriverState *bs) 1469 { 1470 if (bs->dev_ops && bs->dev_ops->is_tray_open) { 1471 return bs->dev_ops->is_tray_open(bs->dev_opaque); 1472 } 1473 return false; 1474 } 1475 1476 static void bdrv_dev_resize_cb(BlockDriverState *bs) 1477 { 1478 if (bs->dev_ops && bs->dev_ops->resize_cb) { 1479 bs->dev_ops->resize_cb(bs->dev_opaque); 1480 } 1481 } 1482 1483 bool bdrv_dev_is_medium_locked(BlockDriverState *bs) 1484 { 1485 if (bs->dev_ops && bs->dev_ops->is_medium_locked) { 1486 return bs->dev_ops->is_medium_locked(bs->dev_opaque); 1487 } 1488 return false; 1489 } 1490 1491 /* 1492 * Run consistency checks on an image 1493 * 1494 * Returns 0 if the check could be completed (it doesn't mean that the image is 1495 * free of errors) or -errno when an internal error occurred. The results of the 1496 * check are stored in res. 1497 */ 1498 int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix) 1499 { 1500 if (bs->drv->bdrv_check == NULL) { 1501 return -ENOTSUP; 1502 } 1503 1504 memset(res, 0, sizeof(*res)); 1505 return bs->drv->bdrv_check(bs, res, fix); 1506 } 1507 1508 #define COMMIT_BUF_SECTORS 2048 1509 1510 /* commit COW file into the raw image */ 1511 int bdrv_commit(BlockDriverState *bs) 1512 { 1513 BlockDriver *drv = bs->drv; 1514 int64_t sector, total_sectors; 1515 int n, ro, open_flags; 1516 int ret = 0; 1517 uint8_t *buf; 1518 char filename[PATH_MAX]; 1519 1520 if (!drv) 1521 return -ENOMEDIUM; 1522 1523 if (!bs->backing_hd) { 1524 return -ENOTSUP; 1525 } 1526 1527 if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) { 1528 return -EBUSY; 1529 } 1530 1531 ro = bs->backing_hd->read_only; 1532 /* Use pstrcpy (not strncpy): filename must be NUL-terminated. */ 1533 pstrcpy(filename, sizeof(filename), bs->backing_hd->filename); 1534 open_flags = bs->backing_hd->open_flags; 1535 1536 if (ro) { 1537 if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) { 1538 return -EACCES; 1539 } 1540 } 1541 1542 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; 1543 buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE); 1544 1545 for (sector = 0; sector < total_sectors; sector += n) { 1546 if (bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n)) { 1547 1548 if (bdrv_read(bs, sector, buf, n) != 0) { 1549 ret = -EIO; 1550 goto ro_cleanup; 1551 } 1552 1553 if (bdrv_write(bs->backing_hd, sector, buf, n) != 0) { 1554 ret = -EIO; 1555 goto ro_cleanup; 1556 } 1557 } 1558 } 1559 1560 if (drv->bdrv_make_empty) { 1561 ret = drv->bdrv_make_empty(bs); 1562 bdrv_flush(bs); 1563 } 1564 1565 /* 1566 * Make sure all data we wrote to the backing device is actually 1567 * stable on disk. 1568 */ 1569 if (bs->backing_hd) 1570 bdrv_flush(bs->backing_hd); 1571 1572 ro_cleanup: 1573 g_free(buf); 1574 1575 if (ro) { 1576 /* ignoring error return here */ 1577 bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL); 1578 } 1579 1580 return ret; 1581 } 1582 1583 int bdrv_commit_all(void) 1584 { 1585 BlockDriverState *bs; 1586 1587 QTAILQ_FOREACH(bs, &bdrv_states, list) { 1588 int ret = bdrv_commit(bs); 1589 if (ret < 0) { 1590 return ret; 1591 } 1592 } 1593 return 0; 1594 } 1595 1596 struct BdrvTrackedRequest { 1597 BlockDriverState *bs; 1598 int64_t sector_num; 1599 int nb_sectors; 1600 bool is_write; 1601 QLIST_ENTRY(BdrvTrackedRequest) list; 1602 Coroutine *co; /* owner, used for deadlock detection */ 1603 CoQueue wait_queue; /* coroutines blocked on this request */ 1604 }; 1605 1606 /** 1607 * Remove an active request from the tracked requests list 1608 * 1609 * This function should be called when a tracked request is completing. 1610 */ 1611 static void tracked_request_end(BdrvTrackedRequest *req) 1612 { 1613 QLIST_REMOVE(req, list); 1614 qemu_co_queue_restart_all(&req->wait_queue); 1615 } 1616 1617 /** 1618 * Add an active request to the tracked requests list 1619 */ 1620 static void tracked_request_begin(BdrvTrackedRequest *req, 1621 BlockDriverState *bs, 1622 int64_t sector_num, 1623 int nb_sectors, bool is_write) 1624 { 1625 *req = (BdrvTrackedRequest){ 1626 .bs = bs, 1627 .sector_num = sector_num, 1628 .nb_sectors = nb_sectors, 1629 .is_write = is_write, 1630 .co = qemu_coroutine_self(), 1631 }; 1632 1633 qemu_co_queue_init(&req->wait_queue); 1634 1635 QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); 1636 } 1637 1638 /** 1639 * Round a region to cluster boundaries 1640 */ 1641 static void round_to_clusters(BlockDriverState *bs, 1642 int64_t sector_num, int nb_sectors, 1643 int64_t *cluster_sector_num, 1644 int *cluster_nb_sectors) 1645 { 1646 BlockDriverInfo bdi; 1647 1648 if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { 1649 *cluster_sector_num = sector_num; 1650 *cluster_nb_sectors = nb_sectors; 1651 } else { 1652 int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE; 1653 *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c); 1654 *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num + 1655 nb_sectors, c); 1656 } 1657 } 1658 1659 static bool tracked_request_overlaps(BdrvTrackedRequest *req, 1660 int64_t sector_num, int nb_sectors) { 1661 /* aaaa bbbb */ 1662 if (sector_num >= req->sector_num + req->nb_sectors) { 1663 return false; 1664 } 1665 /* bbbb aaaa */ 1666 if (req->sector_num >= sector_num + nb_sectors) { 1667 return false; 1668 } 1669 return true; 1670 } 1671 1672 static void coroutine_fn wait_for_overlapping_requests(BlockDriverState *bs, 1673 int64_t sector_num, int nb_sectors) 1674 { 1675 BdrvTrackedRequest *req; 1676 int64_t cluster_sector_num; 1677 int cluster_nb_sectors; 1678 bool retry; 1679 1680 /* If we touch the same cluster it counts as an overlap. This guarantees 1681 * that allocating writes will be serialized and not race with each other 1682 * for the same cluster. For example, in copy-on-read it ensures that the 1683 * CoR read and write operations are atomic and guest writes cannot 1684 * interleave between them. 1685 */ 1686 round_to_clusters(bs, sector_num, nb_sectors, 1687 &cluster_sector_num, &cluster_nb_sectors); 1688 1689 do { 1690 retry = false; 1691 QLIST_FOREACH(req, &bs->tracked_requests, list) { 1692 if (tracked_request_overlaps(req, cluster_sector_num, 1693 cluster_nb_sectors)) { 1694 /* Hitting this means there was a reentrant request, for 1695 * example, a block driver issuing nested requests. This must 1696 * never happen since it means deadlock. 1697 */ 1698 assert(qemu_coroutine_self() != req->co); 1699 1700 qemu_co_queue_wait(&req->wait_queue); 1701 retry = true; 1702 break; 1703 } 1704 } 1705 } while (retry); 1706 } 1707 1708 /* 1709 * Return values: 1710 * 0 - success 1711 * -EINVAL - backing format specified, but no file 1712 * -ENOSPC - can't update the backing file because no space is left in the 1713 * image file header 1714 * -ENOTSUP - format driver doesn't support changing the backing file 1715 */ 1716 int bdrv_change_backing_file(BlockDriverState *bs, 1717 const char *backing_file, const char *backing_fmt) 1718 { 1719 BlockDriver *drv = bs->drv; 1720 int ret; 1721 1722 /* Backing file format doesn't make sense without a backing file */ 1723 if (backing_fmt && !backing_file) { 1724 return -EINVAL; 1725 } 1726 1727 if (drv->bdrv_change_backing_file != NULL) { 1728 ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); 1729 } else { 1730 ret = -ENOTSUP; 1731 } 1732 1733 if (ret == 0) { 1734 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); 1735 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); 1736 } 1737 return ret; 1738 } 1739 1740 /* 1741 * Finds the image layer in the chain that has 'bs' as its backing file. 1742 * 1743 * active is the current topmost image. 1744 * 1745 * Returns NULL if bs is not found in active's image chain, 1746 * or if active == bs. 1747 */ 1748 BlockDriverState *bdrv_find_overlay(BlockDriverState *active, 1749 BlockDriverState *bs) 1750 { 1751 BlockDriverState *overlay = NULL; 1752 BlockDriverState *intermediate; 1753 1754 assert(active != NULL); 1755 assert(bs != NULL); 1756 1757 /* if bs is the same as active, then by definition it has no overlay 1758 */ 1759 if (active == bs) { 1760 return NULL; 1761 } 1762 1763 intermediate = active; 1764 while (intermediate->backing_hd) { 1765 if (intermediate->backing_hd == bs) { 1766 overlay = intermediate; 1767 break; 1768 } 1769 intermediate = intermediate->backing_hd; 1770 } 1771 1772 return overlay; 1773 } 1774 1775 typedef struct BlkIntermediateStates { 1776 BlockDriverState *bs; 1777 QSIMPLEQ_ENTRY(BlkIntermediateStates) entry; 1778 } BlkIntermediateStates; 1779 1780 1781 /* 1782 * Drops images above 'base' up to and including 'top', and sets the image 1783 * above 'top' to have base as its backing file. 1784 * 1785 * Requires that the overlay to 'top' is opened r/w, so that the backing file 1786 * information in 'bs' can be properly updated. 1787 * 1788 * E.g., this will convert the following chain: 1789 * bottom <- base <- intermediate <- top <- active 1790 * 1791 * to 1792 * 1793 * bottom <- base <- active 1794 * 1795 * It is allowed for bottom==base, in which case it converts: 1796 * 1797 * base <- intermediate <- top <- active 1798 * 1799 * to 1800 * 1801 * base <- active 1802 * 1803 * Error conditions: 1804 * if active == top, that is considered an error 1805 * 1806 */ 1807 int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, 1808 BlockDriverState *base) 1809 { 1810 BlockDriverState *intermediate; 1811 BlockDriverState *base_bs = NULL; 1812 BlockDriverState *new_top_bs = NULL; 1813 BlkIntermediateStates *intermediate_state, *next; 1814 int ret = -EIO; 1815 1816 QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete; 1817 QSIMPLEQ_INIT(&states_to_delete); 1818 1819 if (!top->drv || !base->drv) { 1820 goto exit; 1821 } 1822 1823 new_top_bs = bdrv_find_overlay(active, top); 1824 1825 if (new_top_bs == NULL) { 1826 /* we could not find the image above 'top', this is an error */ 1827 goto exit; 1828 } 1829 1830 /* special case of new_top_bs->backing_hd already pointing to base - nothing 1831 * to do, no intermediate images */ 1832 if (new_top_bs->backing_hd == base) { 1833 ret = 0; 1834 goto exit; 1835 } 1836 1837 intermediate = top; 1838 1839 /* now we will go down through the list, and add each BDS we find 1840 * into our deletion queue, until we hit the 'base' 1841 */ 1842 while (intermediate) { 1843 intermediate_state = g_malloc0(sizeof(BlkIntermediateStates)); 1844 intermediate_state->bs = intermediate; 1845 QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry); 1846 1847 if (intermediate->backing_hd == base) { 1848 base_bs = intermediate->backing_hd; 1849 break; 1850 } 1851 intermediate = intermediate->backing_hd; 1852 } 1853 if (base_bs == NULL) { 1854 /* something went wrong, we did not end at the base. safely 1855 * unravel everything, and exit with error */ 1856 goto exit; 1857 } 1858 1859 /* success - we can delete the intermediate states, and link top->base */ 1860 ret = bdrv_change_backing_file(new_top_bs, base_bs->filename, 1861 base_bs->drv ? base_bs->drv->format_name : ""); 1862 if (ret) { 1863 goto exit; 1864 } 1865 new_top_bs->backing_hd = base_bs; 1866 1867 1868 QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { 1869 /* so that bdrv_close() does not recursively close the chain */ 1870 intermediate_state->bs->backing_hd = NULL; 1871 bdrv_delete(intermediate_state->bs); 1872 } 1873 ret = 0; 1874 1875 exit: 1876 QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { 1877 g_free(intermediate_state); 1878 } 1879 return ret; 1880 } 1881 1882 1883 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, 1884 size_t size) 1885 { 1886 int64_t len; 1887 1888 if (!bdrv_is_inserted(bs)) 1889 return -ENOMEDIUM; 1890 1891 if (bs->growable) 1892 return 0; 1893 1894 len = bdrv_getlength(bs); 1895 1896 if (offset < 0) 1897 return -EIO; 1898 1899 if ((offset > len) || (len - offset < size)) 1900 return -EIO; 1901 1902 return 0; 1903 } 1904 1905 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num, 1906 int nb_sectors) 1907 { 1908 return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE, 1909 nb_sectors * BDRV_SECTOR_SIZE); 1910 } 1911 1912 typedef struct RwCo { 1913 BlockDriverState *bs; 1914 int64_t sector_num; 1915 int nb_sectors; 1916 QEMUIOVector *qiov; 1917 bool is_write; 1918 int ret; 1919 } RwCo; 1920 1921 static void coroutine_fn bdrv_rw_co_entry(void *opaque) 1922 { 1923 RwCo *rwco = opaque; 1924 1925 if (!rwco->is_write) { 1926 rwco->ret = bdrv_co_do_readv(rwco->bs, rwco->sector_num, 1927 rwco->nb_sectors, rwco->qiov, 0); 1928 } else { 1929 rwco->ret = bdrv_co_do_writev(rwco->bs, rwco->sector_num, 1930 rwco->nb_sectors, rwco->qiov, 0); 1931 } 1932 } 1933 1934 /* 1935 * Process a synchronous request using coroutines 1936 */ 1937 static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, 1938 int nb_sectors, bool is_write) 1939 { 1940 QEMUIOVector qiov; 1941 struct iovec iov = { 1942 .iov_base = (void *)buf, 1943 .iov_len = nb_sectors * BDRV_SECTOR_SIZE, 1944 }; 1945 Coroutine *co; 1946 RwCo rwco = { 1947 .bs = bs, 1948 .sector_num = sector_num, 1949 .nb_sectors = nb_sectors, 1950 .qiov = &qiov, 1951 .is_write = is_write, 1952 .ret = NOT_DONE, 1953 }; 1954 1955 qemu_iovec_init_external(&qiov, &iov, 1); 1956 1957 /** 1958 * In sync call context, when the vcpu is blocked, this throttling timer 1959 * will not fire; so the I/O throttling function has to be disabled here 1960 * if it has been enabled. 1961 */ 1962 if (bs->io_limits_enabled) { 1963 fprintf(stderr, "Disabling I/O throttling on '%s' due " 1964 "to synchronous I/O.\n", bdrv_get_device_name(bs)); 1965 bdrv_io_limits_disable(bs); 1966 } 1967 1968 if (qemu_in_coroutine()) { 1969 /* Fast-path if already in coroutine context */ 1970 bdrv_rw_co_entry(&rwco); 1971 } else { 1972 co = qemu_coroutine_create(bdrv_rw_co_entry); 1973 qemu_coroutine_enter(co, &rwco); 1974 while (rwco.ret == NOT_DONE) { 1975 qemu_aio_wait(); 1976 } 1977 } 1978 return rwco.ret; 1979 } 1980 1981 /* return < 0 if error. See bdrv_write() for the return codes */ 1982 int bdrv_read(BlockDriverState *bs, int64_t sector_num, 1983 uint8_t *buf, int nb_sectors) 1984 { 1985 return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false); 1986 } 1987 1988 /* Just like bdrv_read(), but with I/O throttling temporarily disabled */ 1989 int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num, 1990 uint8_t *buf, int nb_sectors) 1991 { 1992 bool enabled; 1993 int ret; 1994 1995 enabled = bs->io_limits_enabled; 1996 bs->io_limits_enabled = false; 1997 ret = bdrv_read(bs, 0, buf, 1); 1998 bs->io_limits_enabled = enabled; 1999 return ret; 2000 } 2001 2002 #define BITS_PER_LONG (sizeof(unsigned long) * 8) 2003 2004 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num, 2005 int nb_sectors, int dirty) 2006 { 2007 int64_t start, end; 2008 unsigned long val, idx, bit; 2009 2010 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK; 2011 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK; 2012 2013 for (; start <= end; start++) { 2014 idx = start / BITS_PER_LONG; 2015 bit = start % BITS_PER_LONG; 2016 val = bs->dirty_bitmap[idx]; 2017 if (dirty) { 2018 if (!(val & (1UL << bit))) { 2019 bs->dirty_count++; 2020 val |= 1UL << bit; 2021 } 2022 } else { 2023 if (val & (1UL << bit)) { 2024 bs->dirty_count--; 2025 val &= ~(1UL << bit); 2026 } 2027 } 2028 bs->dirty_bitmap[idx] = val; 2029 } 2030 } 2031 2032 /* Return < 0 if error. Important errors are: 2033 -EIO generic I/O error (may happen for all errors) 2034 -ENOMEDIUM No media inserted. 2035 -EINVAL Invalid sector number or nb_sectors 2036 -EACCES Trying to write a read-only device 2037 */ 2038 int bdrv_write(BlockDriverState *bs, int64_t sector_num, 2039 const uint8_t *buf, int nb_sectors) 2040 { 2041 return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true); 2042 } 2043 2044 int bdrv_pread(BlockDriverState *bs, int64_t offset, 2045 void *buf, int count1) 2046 { 2047 uint8_t tmp_buf[BDRV_SECTOR_SIZE]; 2048 int len, nb_sectors, count; 2049 int64_t sector_num; 2050 int ret; 2051 2052 count = count1; 2053 /* first read to align to sector start */ 2054 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1); 2055 if (len > count) 2056 len = count; 2057 sector_num = offset >> BDRV_SECTOR_BITS; 2058 if (len > 0) { 2059 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) 2060 return ret; 2061 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len); 2062 count -= len; 2063 if (count == 0) 2064 return count1; 2065 sector_num++; 2066 buf += len; 2067 } 2068 2069 /* read the sectors "in place" */ 2070 nb_sectors = count >> BDRV_SECTOR_BITS; 2071 if (nb_sectors > 0) { 2072 if ((ret = bdrv_read(bs, sector_num, buf, nb_sectors)) < 0) 2073 return ret; 2074 sector_num += nb_sectors; 2075 len = nb_sectors << BDRV_SECTOR_BITS; 2076 buf += len; 2077 count -= len; 2078 } 2079 2080 /* add data from the last sector */ 2081 if (count > 0) { 2082 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) 2083 return ret; 2084 memcpy(buf, tmp_buf, count); 2085 } 2086 return count1; 2087 } 2088 2089 int bdrv_pwrite(BlockDriverState *bs, int64_t offset, 2090 const void *buf, int count1) 2091 { 2092 uint8_t tmp_buf[BDRV_SECTOR_SIZE]; 2093 int len, nb_sectors, count; 2094 int64_t sector_num; 2095 int ret; 2096 2097 count = count1; 2098 /* first write to align to sector start */ 2099 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1); 2100 if (len > count) 2101 len = count; 2102 sector_num = offset >> BDRV_SECTOR_BITS; 2103 if (len > 0) { 2104 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) 2105 return ret; 2106 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len); 2107 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) 2108 return ret; 2109 count -= len; 2110 if (count == 0) 2111 return count1; 2112 sector_num++; 2113 buf += len; 2114 } 2115 2116 /* write the sectors "in place" */ 2117 nb_sectors = count >> BDRV_SECTOR_BITS; 2118 if (nb_sectors > 0) { 2119 if ((ret = bdrv_write(bs, sector_num, buf, nb_sectors)) < 0) 2120 return ret; 2121 sector_num += nb_sectors; 2122 len = nb_sectors << BDRV_SECTOR_BITS; 2123 buf += len; 2124 count -= len; 2125 } 2126 2127 /* add data from the last sector */ 2128 if (count > 0) { 2129 if ((ret = bdrv_read(bs, sector_num, tmp_buf, 1)) < 0) 2130 return ret; 2131 memcpy(tmp_buf, buf, count); 2132 if ((ret = bdrv_write(bs, sector_num, tmp_buf, 1)) < 0) 2133 return ret; 2134 } 2135 return count1; 2136 } 2137 2138 /* 2139 * Writes to the file and ensures that no writes are reordered across this 2140 * request (acts as a barrier) 2141 * 2142 * Returns 0 on success, -errno in error cases. 2143 */ 2144 int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset, 2145 const void *buf, int count) 2146 { 2147 int ret; 2148 2149 ret = bdrv_pwrite(bs, offset, buf, count); 2150 if (ret < 0) { 2151 return ret; 2152 } 2153 2154 /* No flush needed for cache modes that already do it */ 2155 if (bs->enable_write_cache) { 2156 bdrv_flush(bs); 2157 } 2158 2159 return 0; 2160 } 2161 2162 static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, 2163 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) 2164 { 2165 /* Perform I/O through a temporary buffer so that users who scribble over 2166 * their read buffer while the operation is in progress do not end up 2167 * modifying the image file. This is critical for zero-copy guest I/O 2168 * where anything might happen inside guest memory. 2169 */ 2170 void *bounce_buffer; 2171 2172 BlockDriver *drv = bs->drv; 2173 struct iovec iov; 2174 QEMUIOVector bounce_qiov; 2175 int64_t cluster_sector_num; 2176 int cluster_nb_sectors; 2177 size_t skip_bytes; 2178 int ret; 2179 2180 /* Cover entire cluster so no additional backing file I/O is required when 2181 * allocating cluster in the image file. 2182 */ 2183 round_to_clusters(bs, sector_num, nb_sectors, 2184 &cluster_sector_num, &cluster_nb_sectors); 2185 2186 trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, 2187 cluster_sector_num, cluster_nb_sectors); 2188 2189 iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE; 2190 iov.iov_base = bounce_buffer = qemu_blockalign(bs, iov.iov_len); 2191 qemu_iovec_init_external(&bounce_qiov, &iov, 1); 2192 2193 ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, 2194 &bounce_qiov); 2195 if (ret < 0) { 2196 goto err; 2197 } 2198 2199 if (drv->bdrv_co_write_zeroes && 2200 buffer_is_zero(bounce_buffer, iov.iov_len)) { 2201 ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num, 2202 cluster_nb_sectors); 2203 } else { 2204 /* This does not change the data on the disk, it is not necessary 2205 * to flush even in cache=writethrough mode. 2206 */ 2207 ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, 2208 &bounce_qiov); 2209 } 2210 2211 if (ret < 0) { 2212 /* It might be okay to ignore write errors for guest requests. If this 2213 * is a deliberate copy-on-read then we don't want to ignore the error. 2214 * Simply report it in all cases. 2215 */ 2216 goto err; 2217 } 2218 2219 skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE; 2220 qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes, 2221 nb_sectors * BDRV_SECTOR_SIZE); 2222 2223 err: 2224 qemu_vfree(bounce_buffer); 2225 return ret; 2226 } 2227 2228 /* 2229 * Handle a read request in coroutine context 2230 */ 2231 static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, 2232 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, 2233 BdrvRequestFlags flags) 2234 { 2235 BlockDriver *drv = bs->drv; 2236 BdrvTrackedRequest req; 2237 int ret; 2238 2239 if (!drv) { 2240 return -ENOMEDIUM; 2241 } 2242 if (bdrv_check_request(bs, sector_num, nb_sectors)) { 2243 return -EIO; 2244 } 2245 2246 /* throttling disk read I/O */ 2247 if (bs->io_limits_enabled) { 2248 bdrv_io_limits_intercept(bs, false, nb_sectors); 2249 } 2250 2251 if (bs->copy_on_read) { 2252 flags |= BDRV_REQ_COPY_ON_READ; 2253 } 2254 if (flags & BDRV_REQ_COPY_ON_READ) { 2255 bs->copy_on_read_in_flight++; 2256 } 2257 2258 if (bs->copy_on_read_in_flight) { 2259 wait_for_overlapping_requests(bs, sector_num, nb_sectors); 2260 } 2261 2262 tracked_request_begin(&req, bs, sector_num, nb_sectors, false); 2263 2264 if (flags & BDRV_REQ_COPY_ON_READ) { 2265 int pnum; 2266 2267 ret = bdrv_co_is_allocated(bs, sector_num, nb_sectors, &pnum); 2268 if (ret < 0) { 2269 goto out; 2270 } 2271 2272 if (!ret || pnum != nb_sectors) { 2273 ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov); 2274 goto out; 2275 } 2276 } 2277 2278 ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); 2279 2280 out: 2281 tracked_request_end(&req); 2282 2283 if (flags & BDRV_REQ_COPY_ON_READ) { 2284 bs->copy_on_read_in_flight--; 2285 } 2286 2287 return ret; 2288 } 2289 2290 int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num, 2291 int nb_sectors, QEMUIOVector *qiov) 2292 { 2293 trace_bdrv_co_readv(bs, sector_num, nb_sectors); 2294 2295 return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0); 2296 } 2297 2298 int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs, 2299 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) 2300 { 2301 trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors); 2302 2303 return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 2304 BDRV_REQ_COPY_ON_READ); 2305 } 2306 2307 static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, 2308 int64_t sector_num, int nb_sectors) 2309 { 2310 BlockDriver *drv = bs->drv; 2311 QEMUIOVector qiov; 2312 struct iovec iov; 2313 int ret; 2314 2315 /* TODO Emulate only part of misaligned requests instead of letting block 2316 * drivers return -ENOTSUP and emulate everything */ 2317 2318 /* First try the efficient write zeroes operation */ 2319 if (drv->bdrv_co_write_zeroes) { 2320 ret = drv->bdrv_co_write_zeroes(bs, sector_num, nb_sectors); 2321 if (ret != -ENOTSUP) { 2322 return ret; 2323 } 2324 } 2325 2326 /* Fall back to bounce buffer if write zeroes is unsupported */ 2327 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE; 2328 iov.iov_base = qemu_blockalign(bs, iov.iov_len); 2329 memset(iov.iov_base, 0, iov.iov_len); 2330 qemu_iovec_init_external(&qiov, &iov, 1); 2331 2332 ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, &qiov); 2333 2334 qemu_vfree(iov.iov_base); 2335 return ret; 2336 } 2337 2338 /* 2339 * Handle a write request in coroutine context 2340 */ 2341 static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, 2342 int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, 2343 BdrvRequestFlags flags) 2344 { 2345 BlockDriver *drv = bs->drv; 2346 BdrvTrackedRequest req; 2347 int ret; 2348 2349 if (!bs->drv) { 2350 return -ENOMEDIUM; 2351 } 2352 if (bs->read_only) { 2353 return -EACCES; 2354 } 2355 if (bdrv_check_request(bs, sector_num, nb_sectors)) { 2356 return -EIO; 2357 } 2358 2359 /* throttling disk write I/O */ 2360 if (bs->io_limits_enabled) { 2361 bdrv_io_limits_intercept(bs, true, nb_sectors); 2362 } 2363 2364 if (bs->copy_on_read_in_flight) { 2365 wait_for_overlapping_requests(bs, sector_num, nb_sectors); 2366 } 2367 2368 tracked_request_begin(&req, bs, sector_num, nb_sectors, true); 2369 2370 if (flags & BDRV_REQ_ZERO_WRITE) { 2371 ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors); 2372 } else { 2373 ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); 2374 } 2375 2376 if (ret == 0 && !bs->enable_write_cache) { 2377 ret = bdrv_co_flush(bs); 2378 } 2379 2380 if (bs->dirty_bitmap) { 2381 set_dirty_bitmap(bs, sector_num, nb_sectors, 1); 2382 } 2383 2384 if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { 2385 bs->wr_highest_sector = sector_num + nb_sectors - 1; 2386 } 2387 2388 tracked_request_end(&req); 2389 2390 return ret; 2391 } 2392 2393 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num, 2394 int nb_sectors, QEMUIOVector *qiov) 2395 { 2396 trace_bdrv_co_writev(bs, sector_num, nb_sectors); 2397 2398 return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0); 2399 } 2400 2401 int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, 2402 int64_t sector_num, int nb_sectors) 2403 { 2404 trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors); 2405 2406 return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL, 2407 BDRV_REQ_ZERO_WRITE); 2408 } 2409 2410 /** 2411 * Truncate file to 'offset' bytes (needed only for file protocols) 2412 */ 2413 int bdrv_truncate(BlockDriverState *bs, int64_t offset) 2414 { 2415 BlockDriver *drv = bs->drv; 2416 int ret; 2417 if (!drv) 2418 return -ENOMEDIUM; 2419 if (!drv->bdrv_truncate) 2420 return -ENOTSUP; 2421 if (bs->read_only) 2422 return -EACCES; 2423 if (bdrv_in_use(bs)) 2424 return -EBUSY; 2425 ret = drv->bdrv_truncate(bs, offset); 2426 if (ret == 0) { 2427 ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); 2428 bdrv_dev_resize_cb(bs); 2429 } 2430 return ret; 2431 } 2432 2433 /** 2434 * Length of a allocated file in bytes. Sparse files are counted by actual 2435 * allocated space. Return < 0 if error or unknown. 2436 */ 2437 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) 2438 { 2439 BlockDriver *drv = bs->drv; 2440 if (!drv) { 2441 return -ENOMEDIUM; 2442 } 2443 if (drv->bdrv_get_allocated_file_size) { 2444 return drv->bdrv_get_allocated_file_size(bs); 2445 } 2446 if (bs->file) { 2447 return bdrv_get_allocated_file_size(bs->file); 2448 } 2449 return -ENOTSUP; 2450 } 2451 2452 /** 2453 * Length of a file in bytes. Return < 0 if error or unknown. 2454 */ 2455 int64_t bdrv_getlength(BlockDriverState *bs) 2456 { 2457 BlockDriver *drv = bs->drv; 2458 if (!drv) 2459 return -ENOMEDIUM; 2460 2461 if (bs->growable || bdrv_dev_has_removable_media(bs)) { 2462 if (drv->bdrv_getlength) { 2463 return drv->bdrv_getlength(bs); 2464 } 2465 } 2466 return bs->total_sectors * BDRV_SECTOR_SIZE; 2467 } 2468 2469 /* return 0 as number of sectors if no device present or error */ 2470 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) 2471 { 2472 int64_t length; 2473 length = bdrv_getlength(bs); 2474 if (length < 0) 2475 length = 0; 2476 else 2477 length = length >> BDRV_SECTOR_BITS; 2478 *nb_sectors_ptr = length; 2479 } 2480 2481 /* throttling disk io limits */ 2482 void bdrv_set_io_limits(BlockDriverState *bs, 2483 BlockIOLimit *io_limits) 2484 { 2485 bs->io_limits = *io_limits; 2486 bs->io_limits_enabled = bdrv_io_limits_enabled(bs); 2487 } 2488 2489 void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error, 2490 BlockdevOnError on_write_error) 2491 { 2492 bs->on_read_error = on_read_error; 2493 bs->on_write_error = on_write_error; 2494 } 2495 2496 BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read) 2497 { 2498 return is_read ? bs->on_read_error : bs->on_write_error; 2499 } 2500 2501 BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error) 2502 { 2503 BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error; 2504 2505 switch (on_err) { 2506 case BLOCKDEV_ON_ERROR_ENOSPC: 2507 return (error == ENOSPC) ? BDRV_ACTION_STOP : BDRV_ACTION_REPORT; 2508 case BLOCKDEV_ON_ERROR_STOP: 2509 return BDRV_ACTION_STOP; 2510 case BLOCKDEV_ON_ERROR_REPORT: 2511 return BDRV_ACTION_REPORT; 2512 case BLOCKDEV_ON_ERROR_IGNORE: 2513 return BDRV_ACTION_IGNORE; 2514 default: 2515 abort(); 2516 } 2517 } 2518 2519 /* This is done by device models because, while the block layer knows 2520 * about the error, it does not know whether an operation comes from 2521 * the device or the block layer (from a job, for example). 2522 */ 2523 void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action, 2524 bool is_read, int error) 2525 { 2526 assert(error >= 0); 2527 bdrv_emit_qmp_error_event(bs, QEVENT_BLOCK_IO_ERROR, action, is_read); 2528 if (action == BDRV_ACTION_STOP) { 2529 vm_stop(RUN_STATE_IO_ERROR); 2530 bdrv_iostatus_set_err(bs, error); 2531 } 2532 } 2533 2534 int bdrv_is_read_only(BlockDriverState *bs) 2535 { 2536 return bs->read_only; 2537 } 2538 2539 int bdrv_is_sg(BlockDriverState *bs) 2540 { 2541 return bs->sg; 2542 } 2543 2544 int bdrv_enable_write_cache(BlockDriverState *bs) 2545 { 2546 return bs->enable_write_cache; 2547 } 2548 2549 void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce) 2550 { 2551 bs->enable_write_cache = wce; 2552 2553 /* so a reopen() will preserve wce */ 2554 if (wce) { 2555 bs->open_flags |= BDRV_O_CACHE_WB; 2556 } else { 2557 bs->open_flags &= ~BDRV_O_CACHE_WB; 2558 } 2559 } 2560 2561 int bdrv_is_encrypted(BlockDriverState *bs) 2562 { 2563 if (bs->backing_hd && bs->backing_hd->encrypted) 2564 return 1; 2565 return bs->encrypted; 2566 } 2567 2568 int bdrv_key_required(BlockDriverState *bs) 2569 { 2570 BlockDriverState *backing_hd = bs->backing_hd; 2571 2572 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key) 2573 return 1; 2574 return (bs->encrypted && !bs->valid_key); 2575 } 2576 2577 int bdrv_set_key(BlockDriverState *bs, const char *key) 2578 { 2579 int ret; 2580 if (bs->backing_hd && bs->backing_hd->encrypted) { 2581 ret = bdrv_set_key(bs->backing_hd, key); 2582 if (ret < 0) 2583 return ret; 2584 if (!bs->encrypted) 2585 return 0; 2586 } 2587 if (!bs->encrypted) { 2588 return -EINVAL; 2589 } else if (!bs->drv || !bs->drv->bdrv_set_key) { 2590 return -ENOMEDIUM; 2591 } 2592 ret = bs->drv->bdrv_set_key(bs, key); 2593 if (ret < 0) { 2594 bs->valid_key = 0; 2595 } else if (!bs->valid_key) { 2596 bs->valid_key = 1; 2597 /* call the change callback now, we skipped it on open */ 2598 bdrv_dev_change_media_cb(bs, true); 2599 } 2600 return ret; 2601 } 2602 2603 const char *bdrv_get_format_name(BlockDriverState *bs) 2604 { 2605 return bs->drv ? bs->drv->format_name : NULL; 2606 } 2607 2608 void bdrv_iterate_format(void (*it)(void *opaque, const char *name), 2609 void *opaque) 2610 { 2611 BlockDriver *drv; 2612 2613 QLIST_FOREACH(drv, &bdrv_drivers, list) { 2614 it(opaque, drv->format_name); 2615 } 2616 } 2617 2618 BlockDriverState *bdrv_find(const char *name) 2619 { 2620 BlockDriverState *bs; 2621 2622 QTAILQ_FOREACH(bs, &bdrv_states, list) { 2623 if (!strcmp(name, bs->device_name)) { 2624 return bs; 2625 } 2626 } 2627 return NULL; 2628 } 2629 2630 BlockDriverState *bdrv_next(BlockDriverState *bs) 2631 { 2632 if (!bs) { 2633 return QTAILQ_FIRST(&bdrv_states); 2634 } 2635 return QTAILQ_NEXT(bs, list); 2636 } 2637 2638 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque) 2639 { 2640 BlockDriverState *bs; 2641 2642 QTAILQ_FOREACH(bs, &bdrv_states, list) { 2643 it(opaque, bs); 2644 } 2645 } 2646 2647 const char *bdrv_get_device_name(BlockDriverState *bs) 2648 { 2649 return bs->device_name; 2650 } 2651 2652 int bdrv_get_flags(BlockDriverState *bs) 2653 { 2654 return bs->open_flags; 2655 } 2656 2657 void bdrv_flush_all(void) 2658 { 2659 BlockDriverState *bs; 2660 2661 QTAILQ_FOREACH(bs, &bdrv_states, list) { 2662 bdrv_flush(bs); 2663 } 2664 } 2665 2666 int bdrv_has_zero_init(BlockDriverState *bs) 2667 { 2668 assert(bs->drv); 2669 2670 if (bs->drv->bdrv_has_zero_init) { 2671 return bs->drv->bdrv_has_zero_init(bs); 2672 } 2673 2674 return 1; 2675 } 2676 2677 typedef struct BdrvCoIsAllocatedData { 2678 BlockDriverState *bs; 2679 int64_t sector_num; 2680 int nb_sectors; 2681 int *pnum; 2682 int ret; 2683 bool done; 2684 } BdrvCoIsAllocatedData; 2685 2686 /* 2687 * Returns true iff the specified sector is present in the disk image. Drivers 2688 * not implementing the functionality are assumed to not support backing files, 2689 * hence all their sectors are reported as allocated. 2690 * 2691 * If 'sector_num' is beyond the end of the disk image the return value is 0 2692 * and 'pnum' is set to 0. 2693 * 2694 * 'pnum' is set to the number of sectors (including and immediately following 2695 * the specified sector) that are known to be in the same 2696 * allocated/unallocated state. 2697 * 2698 * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes 2699 * beyond the end of the disk image it will be clamped. 2700 */ 2701 int coroutine_fn bdrv_co_is_allocated(BlockDriverState *bs, int64_t sector_num, 2702 int nb_sectors, int *pnum) 2703 { 2704 int64_t n; 2705 2706 if (sector_num >= bs->total_sectors) { 2707 *pnum = 0; 2708 return 0; 2709 } 2710 2711 n = bs->total_sectors - sector_num; 2712 if (n < nb_sectors) { 2713 nb_sectors = n; 2714 } 2715 2716 if (!bs->drv->bdrv_co_is_allocated) { 2717 *pnum = nb_sectors; 2718 return 1; 2719 } 2720 2721 return bs->drv->bdrv_co_is_allocated(bs, sector_num, nb_sectors, pnum); 2722 } 2723 2724 /* Coroutine wrapper for bdrv_is_allocated() */ 2725 static void coroutine_fn bdrv_is_allocated_co_entry(void *opaque) 2726 { 2727 BdrvCoIsAllocatedData *data = opaque; 2728 BlockDriverState *bs = data->bs; 2729 2730 data->ret = bdrv_co_is_allocated(bs, data->sector_num, data->nb_sectors, 2731 data->pnum); 2732 data->done = true; 2733 } 2734 2735 /* 2736 * Synchronous wrapper around bdrv_co_is_allocated(). 2737 * 2738 * See bdrv_co_is_allocated() for details. 2739 */ 2740 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors, 2741 int *pnum) 2742 { 2743 Coroutine *co; 2744 BdrvCoIsAllocatedData data = { 2745 .bs = bs, 2746 .sector_num = sector_num, 2747 .nb_sectors = nb_sectors, 2748 .pnum = pnum, 2749 .done = false, 2750 }; 2751 2752 co = qemu_coroutine_create(bdrv_is_allocated_co_entry); 2753 qemu_coroutine_enter(co, &data); 2754 while (!data.done) { 2755 qemu_aio_wait(); 2756 } 2757 return data.ret; 2758 } 2759 2760 /* 2761 * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] 2762 * 2763 * Return true if the given sector is allocated in any image between 2764 * BASE and TOP (inclusive). BASE can be NULL to check if the given 2765 * sector is allocated in any image of the chain. Return false otherwise. 2766 * 2767 * 'pnum' is set to the number of sectors (including and immediately following 2768 * the specified sector) that are known to be in the same 2769 * allocated/unallocated state. 2770 * 2771 */ 2772 int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top, 2773 BlockDriverState *base, 2774 int64_t sector_num, 2775 int nb_sectors, int *pnum) 2776 { 2777 BlockDriverState *intermediate; 2778 int ret, n = nb_sectors; 2779 2780 intermediate = top; 2781 while (intermediate && intermediate != base) { 2782 int pnum_inter; 2783 ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors, 2784 &pnum_inter); 2785 if (ret < 0) { 2786 return ret; 2787 } else if (ret) { 2788 *pnum = pnum_inter; 2789 return 1; 2790 } 2791 2792 /* 2793 * [sector_num, nb_sectors] is unallocated on top but intermediate 2794 * might have 2795 * 2796 * [sector_num+x, nr_sectors] allocated. 2797 */ 2798 if (n > pnum_inter) { 2799 n = pnum_inter; 2800 } 2801 2802 intermediate = intermediate->backing_hd; 2803 } 2804 2805 *pnum = n; 2806 return 0; 2807 } 2808 2809 BlockInfoList *qmp_query_block(Error **errp) 2810 { 2811 BlockInfoList *head = NULL, *cur_item = NULL; 2812 BlockDriverState *bs; 2813 2814 QTAILQ_FOREACH(bs, &bdrv_states, list) { 2815 BlockInfoList *info = g_malloc0(sizeof(*info)); 2816 2817 info->value = g_malloc0(sizeof(*info->value)); 2818 info->value->device = g_strdup(bs->device_name); 2819 info->value->type = g_strdup("unknown"); 2820 info->value->locked = bdrv_dev_is_medium_locked(bs); 2821 info->value->removable = bdrv_dev_has_removable_media(bs); 2822 2823 if (bdrv_dev_has_removable_media(bs)) { 2824 info->value->has_tray_open = true; 2825 info->value->tray_open = bdrv_dev_is_tray_open(bs); 2826 } 2827 2828 if (bdrv_iostatus_is_enabled(bs)) { 2829 info->value->has_io_status = true; 2830 info->value->io_status = bs->iostatus; 2831 } 2832 2833 if (bs->drv) { 2834 info->value->has_inserted = true; 2835 info->value->inserted = g_malloc0(sizeof(*info->value->inserted)); 2836 info->value->inserted->file = g_strdup(bs->filename); 2837 info->value->inserted->ro = bs->read_only; 2838 info->value->inserted->drv = g_strdup(bs->drv->format_name); 2839 info->value->inserted->encrypted = bs->encrypted; 2840 info->value->inserted->encryption_key_missing = bdrv_key_required(bs); 2841 if (bs->backing_file[0]) { 2842 info->value->inserted->has_backing_file = true; 2843 info->value->inserted->backing_file = g_strdup(bs->backing_file); 2844 } 2845 2846 info->value->inserted->backing_file_depth = 2847 bdrv_get_backing_file_depth(bs); 2848 2849 if (bs->io_limits_enabled) { 2850 info->value->inserted->bps = 2851 bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]; 2852 info->value->inserted->bps_rd = 2853 bs->io_limits.bps[BLOCK_IO_LIMIT_READ]; 2854 info->value->inserted->bps_wr = 2855 bs->io_limits.bps[BLOCK_IO_LIMIT_WRITE]; 2856 info->value->inserted->iops = 2857 bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]; 2858 info->value->inserted->iops_rd = 2859 bs->io_limits.iops[BLOCK_IO_LIMIT_READ]; 2860 info->value->inserted->iops_wr = 2861 bs->io_limits.iops[BLOCK_IO_LIMIT_WRITE]; 2862 } 2863 } 2864 2865 /* XXX: waiting for the qapi to support GSList */ 2866 if (!cur_item) { 2867 head = cur_item = info; 2868 } else { 2869 cur_item->next = info; 2870 cur_item = info; 2871 } 2872 } 2873 2874 return head; 2875 } 2876 2877 /* Consider exposing this as a full fledged QMP command */ 2878 static BlockStats *qmp_query_blockstat(const BlockDriverState *bs, Error **errp) 2879 { 2880 BlockStats *s; 2881 2882 s = g_malloc0(sizeof(*s)); 2883 2884 if (bs->device_name[0]) { 2885 s->has_device = true; 2886 s->device = g_strdup(bs->device_name); 2887 } 2888 2889 s->stats = g_malloc0(sizeof(*s->stats)); 2890 s->stats->rd_bytes = bs->nr_bytes[BDRV_ACCT_READ]; 2891 s->stats->wr_bytes = bs->nr_bytes[BDRV_ACCT_WRITE]; 2892 s->stats->rd_operations = bs->nr_ops[BDRV_ACCT_READ]; 2893 s->stats->wr_operations = bs->nr_ops[BDRV_ACCT_WRITE]; 2894 s->stats->wr_highest_offset = bs->wr_highest_sector * BDRV_SECTOR_SIZE; 2895 s->stats->flush_operations = bs->nr_ops[BDRV_ACCT_FLUSH]; 2896 s->stats->wr_total_time_ns = bs->total_time_ns[BDRV_ACCT_WRITE]; 2897 s->stats->rd_total_time_ns = bs->total_time_ns[BDRV_ACCT_READ]; 2898 s->stats->flush_total_time_ns = bs->total_time_ns[BDRV_ACCT_FLUSH]; 2899 2900 if (bs->file) { 2901 s->has_parent = true; 2902 s->parent = qmp_query_blockstat(bs->file, NULL); 2903 } 2904 2905 return s; 2906 } 2907 2908 BlockStatsList *qmp_query_blockstats(Error **errp) 2909 { 2910 BlockStatsList *head = NULL, *cur_item = NULL; 2911 BlockDriverState *bs; 2912 2913 QTAILQ_FOREACH(bs, &bdrv_states, list) { 2914 BlockStatsList *info = g_malloc0(sizeof(*info)); 2915 info->value = qmp_query_blockstat(bs, NULL); 2916 2917 /* XXX: waiting for the qapi to support GSList */ 2918 if (!cur_item) { 2919 head = cur_item = info; 2920 } else { 2921 cur_item->next = info; 2922 cur_item = info; 2923 } 2924 } 2925 2926 return head; 2927 } 2928 2929 const char *bdrv_get_encrypted_filename(BlockDriverState *bs) 2930 { 2931 if (bs->backing_hd && bs->backing_hd->encrypted) 2932 return bs->backing_file; 2933 else if (bs->encrypted) 2934 return bs->filename; 2935 else 2936 return NULL; 2937 } 2938 2939 void bdrv_get_backing_filename(BlockDriverState *bs, 2940 char *filename, int filename_size) 2941 { 2942 pstrcpy(filename, filename_size, bs->backing_file); 2943 } 2944 2945 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num, 2946 const uint8_t *buf, int nb_sectors) 2947 { 2948 BlockDriver *drv = bs->drv; 2949 if (!drv) 2950 return -ENOMEDIUM; 2951 if (!drv->bdrv_write_compressed) 2952 return -ENOTSUP; 2953 if (bdrv_check_request(bs, sector_num, nb_sectors)) 2954 return -EIO; 2955 2956 if (bs->dirty_bitmap) { 2957 set_dirty_bitmap(bs, sector_num, nb_sectors, 1); 2958 } 2959 2960 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); 2961 } 2962 2963 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 2964 { 2965 BlockDriver *drv = bs->drv; 2966 if (!drv) 2967 return -ENOMEDIUM; 2968 if (!drv->bdrv_get_info) 2969 return -ENOTSUP; 2970 memset(bdi, 0, sizeof(*bdi)); 2971 return drv->bdrv_get_info(bs, bdi); 2972 } 2973 2974 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, 2975 int64_t pos, int size) 2976 { 2977 BlockDriver *drv = bs->drv; 2978 if (!drv) 2979 return -ENOMEDIUM; 2980 if (drv->bdrv_save_vmstate) 2981 return drv->bdrv_save_vmstate(bs, buf, pos, size); 2982 if (bs->file) 2983 return bdrv_save_vmstate(bs->file, buf, pos, size); 2984 return -ENOTSUP; 2985 } 2986 2987 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, 2988 int64_t pos, int size) 2989 { 2990 BlockDriver *drv = bs->drv; 2991 if (!drv) 2992 return -ENOMEDIUM; 2993 if (drv->bdrv_load_vmstate) 2994 return drv->bdrv_load_vmstate(bs, buf, pos, size); 2995 if (bs->file) 2996 return bdrv_load_vmstate(bs->file, buf, pos, size); 2997 return -ENOTSUP; 2998 } 2999 3000 void bdrv_debug_event(BlockDriverState *bs, BlkDebugEvent event) 3001 { 3002 BlockDriver *drv = bs->drv; 3003 3004 if (!drv || !drv->bdrv_debug_event) { 3005 return; 3006 } 3007 3008 drv->bdrv_debug_event(bs, event); 3009 3010 } 3011 3012 /**************************************************************/ 3013 /* handling of snapshots */ 3014 3015 int bdrv_can_snapshot(BlockDriverState *bs) 3016 { 3017 BlockDriver *drv = bs->drv; 3018 if (!drv || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { 3019 return 0; 3020 } 3021 3022 if (!drv->bdrv_snapshot_create) { 3023 if (bs->file != NULL) { 3024 return bdrv_can_snapshot(bs->file); 3025 } 3026 return 0; 3027 } 3028 3029 return 1; 3030 } 3031 3032 int bdrv_is_snapshot(BlockDriverState *bs) 3033 { 3034 return !!(bs->open_flags & BDRV_O_SNAPSHOT); 3035 } 3036 3037 BlockDriverState *bdrv_snapshots(void) 3038 { 3039 BlockDriverState *bs; 3040 3041 if (bs_snapshots) { 3042 return bs_snapshots; 3043 } 3044 3045 bs = NULL; 3046 while ((bs = bdrv_next(bs))) { 3047 if (bdrv_can_snapshot(bs)) { 3048 bs_snapshots = bs; 3049 return bs; 3050 } 3051 } 3052 return NULL; 3053 } 3054 3055 int bdrv_snapshot_create(BlockDriverState *bs, 3056 QEMUSnapshotInfo *sn_info) 3057 { 3058 BlockDriver *drv = bs->drv; 3059 if (!drv) 3060 return -ENOMEDIUM; 3061 if (drv->bdrv_snapshot_create) 3062 return drv->bdrv_snapshot_create(bs, sn_info); 3063 if (bs->file) 3064 return bdrv_snapshot_create(bs->file, sn_info); 3065 return -ENOTSUP; 3066 } 3067 3068 int bdrv_snapshot_goto(BlockDriverState *bs, 3069 const char *snapshot_id) 3070 { 3071 BlockDriver *drv = bs->drv; 3072 int ret, open_ret; 3073 3074 if (!drv) 3075 return -ENOMEDIUM; 3076 if (drv->bdrv_snapshot_goto) 3077 return drv->bdrv_snapshot_goto(bs, snapshot_id); 3078 3079 if (bs->file) { 3080 drv->bdrv_close(bs); 3081 ret = bdrv_snapshot_goto(bs->file, snapshot_id); 3082 open_ret = drv->bdrv_open(bs, bs->open_flags); 3083 if (open_ret < 0) { 3084 bdrv_delete(bs->file); 3085 bs->drv = NULL; 3086 return open_ret; 3087 } 3088 return ret; 3089 } 3090 3091 return -ENOTSUP; 3092 } 3093 3094 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id) 3095 { 3096 BlockDriver *drv = bs->drv; 3097 if (!drv) 3098 return -ENOMEDIUM; 3099 if (drv->bdrv_snapshot_delete) 3100 return drv->bdrv_snapshot_delete(bs, snapshot_id); 3101 if (bs->file) 3102 return bdrv_snapshot_delete(bs->file, snapshot_id); 3103 return -ENOTSUP; 3104 } 3105 3106 int bdrv_snapshot_list(BlockDriverState *bs, 3107 QEMUSnapshotInfo **psn_info) 3108 { 3109 BlockDriver *drv = bs->drv; 3110 if (!drv) 3111 return -ENOMEDIUM; 3112 if (drv->bdrv_snapshot_list) 3113 return drv->bdrv_snapshot_list(bs, psn_info); 3114 if (bs->file) 3115 return bdrv_snapshot_list(bs->file, psn_info); 3116 return -ENOTSUP; 3117 } 3118 3119 int bdrv_snapshot_load_tmp(BlockDriverState *bs, 3120 const char *snapshot_name) 3121 { 3122 BlockDriver *drv = bs->drv; 3123 if (!drv) { 3124 return -ENOMEDIUM; 3125 } 3126 if (!bs->read_only) { 3127 return -EINVAL; 3128 } 3129 if (drv->bdrv_snapshot_load_tmp) { 3130 return drv->bdrv_snapshot_load_tmp(bs, snapshot_name); 3131 } 3132 return -ENOTSUP; 3133 } 3134 3135 BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, 3136 const char *backing_file) 3137 { 3138 if (!bs->drv) { 3139 return NULL; 3140 } 3141 3142 if (bs->backing_hd) { 3143 if (strcmp(bs->backing_file, backing_file) == 0) { 3144 return bs->backing_hd; 3145 } else { 3146 return bdrv_find_backing_image(bs->backing_hd, backing_file); 3147 } 3148 } 3149 3150 return NULL; 3151 } 3152 3153 int bdrv_get_backing_file_depth(BlockDriverState *bs) 3154 { 3155 if (!bs->drv) { 3156 return 0; 3157 } 3158 3159 if (!bs->backing_hd) { 3160 return 0; 3161 } 3162 3163 return 1 + bdrv_get_backing_file_depth(bs->backing_hd); 3164 } 3165 3166 BlockDriverState *bdrv_find_base(BlockDriverState *bs) 3167 { 3168 BlockDriverState *curr_bs = NULL; 3169 3170 if (!bs) { 3171 return NULL; 3172 } 3173 3174 curr_bs = bs; 3175 3176 while (curr_bs->backing_hd) { 3177 curr_bs = curr_bs->backing_hd; 3178 } 3179 return curr_bs; 3180 } 3181 3182 #define NB_SUFFIXES 4 3183 3184 char *get_human_readable_size(char *buf, int buf_size, int64_t size) 3185 { 3186 static const char suffixes[NB_SUFFIXES] = "KMGT"; 3187 int64_t base; 3188 int i; 3189 3190 if (size <= 999) { 3191 snprintf(buf, buf_size, "%" PRId64, size); 3192 } else { 3193 base = 1024; 3194 for(i = 0; i < NB_SUFFIXES; i++) { 3195 if (size < (10 * base)) { 3196 snprintf(buf, buf_size, "%0.1f%c", 3197 (double)size / base, 3198 suffixes[i]); 3199 break; 3200 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) { 3201 snprintf(buf, buf_size, "%" PRId64 "%c", 3202 ((size + (base >> 1)) / base), 3203 suffixes[i]); 3204 break; 3205 } 3206 base = base * 1024; 3207 } 3208 } 3209 return buf; 3210 } 3211 3212 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn) 3213 { 3214 char buf1[128], date_buf[128], clock_buf[128]; 3215 #ifdef _WIN32 3216 struct tm *ptm; 3217 #else 3218 struct tm tm; 3219 #endif 3220 time_t ti; 3221 int64_t secs; 3222 3223 if (!sn) { 3224 snprintf(buf, buf_size, 3225 "%-10s%-20s%7s%20s%15s", 3226 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK"); 3227 } else { 3228 ti = sn->date_sec; 3229 #ifdef _WIN32 3230 ptm = localtime(&ti); 3231 strftime(date_buf, sizeof(date_buf), 3232 "%Y-%m-%d %H:%M:%S", ptm); 3233 #else 3234 localtime_r(&ti, &tm); 3235 strftime(date_buf, sizeof(date_buf), 3236 "%Y-%m-%d %H:%M:%S", &tm); 3237 #endif 3238 secs = sn->vm_clock_nsec / 1000000000; 3239 snprintf(clock_buf, sizeof(clock_buf), 3240 "%02d:%02d:%02d.%03d", 3241 (int)(secs / 3600), 3242 (int)((secs / 60) % 60), 3243 (int)(secs % 60), 3244 (int)((sn->vm_clock_nsec / 1000000) % 1000)); 3245 snprintf(buf, buf_size, 3246 "%-10s%-20s%7s%20s%15s", 3247 sn->id_str, sn->name, 3248 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size), 3249 date_buf, 3250 clock_buf); 3251 } 3252 return buf; 3253 } 3254 3255 /**************************************************************/ 3256 /* async I/Os */ 3257 3258 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, 3259 QEMUIOVector *qiov, int nb_sectors, 3260 BlockDriverCompletionFunc *cb, void *opaque) 3261 { 3262 trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque); 3263 3264 return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 3265 cb, opaque, false); 3266 } 3267 3268 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, 3269 QEMUIOVector *qiov, int nb_sectors, 3270 BlockDriverCompletionFunc *cb, void *opaque) 3271 { 3272 trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque); 3273 3274 return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 3275 cb, opaque, true); 3276 } 3277 3278 3279 typedef struct MultiwriteCB { 3280 int error; 3281 int num_requests; 3282 int num_callbacks; 3283 struct { 3284 BlockDriverCompletionFunc *cb; 3285 void *opaque; 3286 QEMUIOVector *free_qiov; 3287 } callbacks[]; 3288 } MultiwriteCB; 3289 3290 static void multiwrite_user_cb(MultiwriteCB *mcb) 3291 { 3292 int i; 3293 3294 for (i = 0; i < mcb->num_callbacks; i++) { 3295 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error); 3296 if (mcb->callbacks[i].free_qiov) { 3297 qemu_iovec_destroy(mcb->callbacks[i].free_qiov); 3298 } 3299 g_free(mcb->callbacks[i].free_qiov); 3300 } 3301 } 3302 3303 static void multiwrite_cb(void *opaque, int ret) 3304 { 3305 MultiwriteCB *mcb = opaque; 3306 3307 trace_multiwrite_cb(mcb, ret); 3308 3309 if (ret < 0 && !mcb->error) { 3310 mcb->error = ret; 3311 } 3312 3313 mcb->num_requests--; 3314 if (mcb->num_requests == 0) { 3315 multiwrite_user_cb(mcb); 3316 g_free(mcb); 3317 } 3318 } 3319 3320 static int multiwrite_req_compare(const void *a, const void *b) 3321 { 3322 const BlockRequest *req1 = a, *req2 = b; 3323 3324 /* 3325 * Note that we can't simply subtract req2->sector from req1->sector 3326 * here as that could overflow the return value. 3327 */ 3328 if (req1->sector > req2->sector) { 3329 return 1; 3330 } else if (req1->sector < req2->sector) { 3331 return -1; 3332 } else { 3333 return 0; 3334 } 3335 } 3336 3337 /* 3338 * Takes a bunch of requests and tries to merge them. Returns the number of 3339 * requests that remain after merging. 3340 */ 3341 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, 3342 int num_reqs, MultiwriteCB *mcb) 3343 { 3344 int i, outidx; 3345 3346 // Sort requests by start sector 3347 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare); 3348 3349 // Check if adjacent requests touch the same clusters. If so, combine them, 3350 // filling up gaps with zero sectors. 3351 outidx = 0; 3352 for (i = 1; i < num_reqs; i++) { 3353 int merge = 0; 3354 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors; 3355 3356 // Handle exactly sequential writes and overlapping writes. 3357 if (reqs[i].sector <= oldreq_last) { 3358 merge = 1; 3359 } 3360 3361 if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) { 3362 merge = 0; 3363 } 3364 3365 if (merge) { 3366 size_t size; 3367 QEMUIOVector *qiov = g_malloc0(sizeof(*qiov)); 3368 qemu_iovec_init(qiov, 3369 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1); 3370 3371 // Add the first request to the merged one. If the requests are 3372 // overlapping, drop the last sectors of the first request. 3373 size = (reqs[i].sector - reqs[outidx].sector) << 9; 3374 qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size); 3375 3376 // We should need to add any zeros between the two requests 3377 assert (reqs[i].sector <= oldreq_last); 3378 3379 // Add the second request 3380 qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size); 3381 3382 reqs[outidx].nb_sectors = qiov->size >> 9; 3383 reqs[outidx].qiov = qiov; 3384 3385 mcb->callbacks[i].free_qiov = reqs[outidx].qiov; 3386 } else { 3387 outidx++; 3388 reqs[outidx].sector = reqs[i].sector; 3389 reqs[outidx].nb_sectors = reqs[i].nb_sectors; 3390 reqs[outidx].qiov = reqs[i].qiov; 3391 } 3392 } 3393 3394 return outidx + 1; 3395 } 3396 3397 /* 3398 * Submit multiple AIO write requests at once. 3399 * 3400 * On success, the function returns 0 and all requests in the reqs array have 3401 * been submitted. In error case this function returns -1, and any of the 3402 * requests may or may not be submitted yet. In particular, this means that the 3403 * callback will be called for some of the requests, for others it won't. The 3404 * caller must check the error field of the BlockRequest to wait for the right 3405 * callbacks (if error != 0, no callback will be called). 3406 * 3407 * The implementation may modify the contents of the reqs array, e.g. to merge 3408 * requests. However, the fields opaque and error are left unmodified as they 3409 * are used to signal failure for a single request to the caller. 3410 */ 3411 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) 3412 { 3413 MultiwriteCB *mcb; 3414 int i; 3415 3416 /* don't submit writes if we don't have a medium */ 3417 if (bs->drv == NULL) { 3418 for (i = 0; i < num_reqs; i++) { 3419 reqs[i].error = -ENOMEDIUM; 3420 } 3421 return -1; 3422 } 3423 3424 if (num_reqs == 0) { 3425 return 0; 3426 } 3427 3428 // Create MultiwriteCB structure 3429 mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); 3430 mcb->num_requests = 0; 3431 mcb->num_callbacks = num_reqs; 3432 3433 for (i = 0; i < num_reqs; i++) { 3434 mcb->callbacks[i].cb = reqs[i].cb; 3435 mcb->callbacks[i].opaque = reqs[i].opaque; 3436 } 3437 3438 // Check for mergable requests 3439 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb); 3440 3441 trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs); 3442 3443 /* Run the aio requests. */ 3444 mcb->num_requests = num_reqs; 3445 for (i = 0; i < num_reqs; i++) { 3446 bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov, 3447 reqs[i].nb_sectors, multiwrite_cb, mcb); 3448 } 3449 3450 return 0; 3451 } 3452 3453 void bdrv_aio_cancel(BlockDriverAIOCB *acb) 3454 { 3455 acb->pool->cancel(acb); 3456 } 3457 3458 /* block I/O throttling */ 3459 static bool bdrv_exceed_bps_limits(BlockDriverState *bs, int nb_sectors, 3460 bool is_write, double elapsed_time, uint64_t *wait) 3461 { 3462 uint64_t bps_limit = 0; 3463 double bytes_limit, bytes_base, bytes_res; 3464 double slice_time, wait_time; 3465 3466 if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) { 3467 bps_limit = bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]; 3468 } else if (bs->io_limits.bps[is_write]) { 3469 bps_limit = bs->io_limits.bps[is_write]; 3470 } else { 3471 if (wait) { 3472 *wait = 0; 3473 } 3474 3475 return false; 3476 } 3477 3478 slice_time = bs->slice_end - bs->slice_start; 3479 slice_time /= (NANOSECONDS_PER_SECOND); 3480 bytes_limit = bps_limit * slice_time; 3481 bytes_base = bs->nr_bytes[is_write] - bs->io_base.bytes[is_write]; 3482 if (bs->io_limits.bps[BLOCK_IO_LIMIT_TOTAL]) { 3483 bytes_base += bs->nr_bytes[!is_write] - bs->io_base.bytes[!is_write]; 3484 } 3485 3486 /* bytes_base: the bytes of data which have been read/written; and 3487 * it is obtained from the history statistic info. 3488 * bytes_res: the remaining bytes of data which need to be read/written. 3489 * (bytes_base + bytes_res) / bps_limit: used to calcuate 3490 * the total time for completing reading/writting all data. 3491 */ 3492 bytes_res = (unsigned) nb_sectors * BDRV_SECTOR_SIZE; 3493 3494 if (bytes_base + bytes_res <= bytes_limit) { 3495 if (wait) { 3496 *wait = 0; 3497 } 3498 3499 return false; 3500 } 3501 3502 /* Calc approx time to dispatch */ 3503 wait_time = (bytes_base + bytes_res) / bps_limit - elapsed_time; 3504 3505 /* When the I/O rate at runtime exceeds the limits, 3506 * bs->slice_end need to be extended in order that the current statistic 3507 * info can be kept until the timer fire, so it is increased and tuned 3508 * based on the result of experiment. 3509 */ 3510 bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10; 3511 bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME; 3512 if (wait) { 3513 *wait = wait_time * BLOCK_IO_SLICE_TIME * 10; 3514 } 3515 3516 return true; 3517 } 3518 3519 static bool bdrv_exceed_iops_limits(BlockDriverState *bs, bool is_write, 3520 double elapsed_time, uint64_t *wait) 3521 { 3522 uint64_t iops_limit = 0; 3523 double ios_limit, ios_base; 3524 double slice_time, wait_time; 3525 3526 if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) { 3527 iops_limit = bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]; 3528 } else if (bs->io_limits.iops[is_write]) { 3529 iops_limit = bs->io_limits.iops[is_write]; 3530 } else { 3531 if (wait) { 3532 *wait = 0; 3533 } 3534 3535 return false; 3536 } 3537 3538 slice_time = bs->slice_end - bs->slice_start; 3539 slice_time /= (NANOSECONDS_PER_SECOND); 3540 ios_limit = iops_limit * slice_time; 3541 ios_base = bs->nr_ops[is_write] - bs->io_base.ios[is_write]; 3542 if (bs->io_limits.iops[BLOCK_IO_LIMIT_TOTAL]) { 3543 ios_base += bs->nr_ops[!is_write] - bs->io_base.ios[!is_write]; 3544 } 3545 3546 if (ios_base + 1 <= ios_limit) { 3547 if (wait) { 3548 *wait = 0; 3549 } 3550 3551 return false; 3552 } 3553 3554 /* Calc approx time to dispatch */ 3555 wait_time = (ios_base + 1) / iops_limit; 3556 if (wait_time > elapsed_time) { 3557 wait_time = wait_time - elapsed_time; 3558 } else { 3559 wait_time = 0; 3560 } 3561 3562 bs->slice_time = wait_time * BLOCK_IO_SLICE_TIME * 10; 3563 bs->slice_end += bs->slice_time - 3 * BLOCK_IO_SLICE_TIME; 3564 if (wait) { 3565 *wait = wait_time * BLOCK_IO_SLICE_TIME * 10; 3566 } 3567 3568 return true; 3569 } 3570 3571 static bool bdrv_exceed_io_limits(BlockDriverState *bs, int nb_sectors, 3572 bool is_write, int64_t *wait) 3573 { 3574 int64_t now, max_wait; 3575 uint64_t bps_wait = 0, iops_wait = 0; 3576 double elapsed_time; 3577 int bps_ret, iops_ret; 3578 3579 now = qemu_get_clock_ns(vm_clock); 3580 if ((bs->slice_start < now) 3581 && (bs->slice_end > now)) { 3582 bs->slice_end = now + bs->slice_time; 3583 } else { 3584 bs->slice_time = 5 * BLOCK_IO_SLICE_TIME; 3585 bs->slice_start = now; 3586 bs->slice_end = now + bs->slice_time; 3587 3588 bs->io_base.bytes[is_write] = bs->nr_bytes[is_write]; 3589 bs->io_base.bytes[!is_write] = bs->nr_bytes[!is_write]; 3590 3591 bs->io_base.ios[is_write] = bs->nr_ops[is_write]; 3592 bs->io_base.ios[!is_write] = bs->nr_ops[!is_write]; 3593 } 3594 3595 elapsed_time = now - bs->slice_start; 3596 elapsed_time /= (NANOSECONDS_PER_SECOND); 3597 3598 bps_ret = bdrv_exceed_bps_limits(bs, nb_sectors, 3599 is_write, elapsed_time, &bps_wait); 3600 iops_ret = bdrv_exceed_iops_limits(bs, is_write, 3601 elapsed_time, &iops_wait); 3602 if (bps_ret || iops_ret) { 3603 max_wait = bps_wait > iops_wait ? bps_wait : iops_wait; 3604 if (wait) { 3605 *wait = max_wait; 3606 } 3607 3608 now = qemu_get_clock_ns(vm_clock); 3609 if (bs->slice_end < now + max_wait) { 3610 bs->slice_end = now + max_wait; 3611 } 3612 3613 return true; 3614 } 3615 3616 if (wait) { 3617 *wait = 0; 3618 } 3619 3620 return false; 3621 } 3622 3623 /**************************************************************/ 3624 /* async block device emulation */ 3625 3626 typedef struct BlockDriverAIOCBSync { 3627 BlockDriverAIOCB common; 3628 QEMUBH *bh; 3629 int ret; 3630 /* vector translation state */ 3631 QEMUIOVector *qiov; 3632 uint8_t *bounce; 3633 int is_write; 3634 } BlockDriverAIOCBSync; 3635 3636 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb) 3637 { 3638 BlockDriverAIOCBSync *acb = 3639 container_of(blockacb, BlockDriverAIOCBSync, common); 3640 qemu_bh_delete(acb->bh); 3641 acb->bh = NULL; 3642 qemu_aio_release(acb); 3643 } 3644 3645 static AIOPool bdrv_em_aio_pool = { 3646 .aiocb_size = sizeof(BlockDriverAIOCBSync), 3647 .cancel = bdrv_aio_cancel_em, 3648 }; 3649 3650 static void bdrv_aio_bh_cb(void *opaque) 3651 { 3652 BlockDriverAIOCBSync *acb = opaque; 3653 3654 if (!acb->is_write) 3655 qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); 3656 qemu_vfree(acb->bounce); 3657 acb->common.cb(acb->common.opaque, acb->ret); 3658 qemu_bh_delete(acb->bh); 3659 acb->bh = NULL; 3660 qemu_aio_release(acb); 3661 } 3662 3663 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs, 3664 int64_t sector_num, 3665 QEMUIOVector *qiov, 3666 int nb_sectors, 3667 BlockDriverCompletionFunc *cb, 3668 void *opaque, 3669 int is_write) 3670 3671 { 3672 BlockDriverAIOCBSync *acb; 3673 3674 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque); 3675 acb->is_write = is_write; 3676 acb->qiov = qiov; 3677 acb->bounce = qemu_blockalign(bs, qiov->size); 3678 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb); 3679 3680 if (is_write) { 3681 qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); 3682 acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors); 3683 } else { 3684 acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors); 3685 } 3686 3687 qemu_bh_schedule(acb->bh); 3688 3689 return &acb->common; 3690 } 3691 3692 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, 3693 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 3694 BlockDriverCompletionFunc *cb, void *opaque) 3695 { 3696 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); 3697 } 3698 3699 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, 3700 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, 3701 BlockDriverCompletionFunc *cb, void *opaque) 3702 { 3703 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); 3704 } 3705 3706 3707 typedef struct BlockDriverAIOCBCoroutine { 3708 BlockDriverAIOCB common; 3709 BlockRequest req; 3710 bool is_write; 3711 QEMUBH* bh; 3712 } BlockDriverAIOCBCoroutine; 3713 3714 static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb) 3715 { 3716 qemu_aio_flush(); 3717 } 3718 3719 static AIOPool bdrv_em_co_aio_pool = { 3720 .aiocb_size = sizeof(BlockDriverAIOCBCoroutine), 3721 .cancel = bdrv_aio_co_cancel_em, 3722 }; 3723 3724 static void bdrv_co_em_bh(void *opaque) 3725 { 3726 BlockDriverAIOCBCoroutine *acb = opaque; 3727 3728 acb->common.cb(acb->common.opaque, acb->req.error); 3729 qemu_bh_delete(acb->bh); 3730 qemu_aio_release(acb); 3731 } 3732 3733 /* Invoke bdrv_co_do_readv/bdrv_co_do_writev */ 3734 static void coroutine_fn bdrv_co_do_rw(void *opaque) 3735 { 3736 BlockDriverAIOCBCoroutine *acb = opaque; 3737 BlockDriverState *bs = acb->common.bs; 3738 3739 if (!acb->is_write) { 3740 acb->req.error = bdrv_co_do_readv(bs, acb->req.sector, 3741 acb->req.nb_sectors, acb->req.qiov, 0); 3742 } else { 3743 acb->req.error = bdrv_co_do_writev(bs, acb->req.sector, 3744 acb->req.nb_sectors, acb->req.qiov, 0); 3745 } 3746 3747 acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); 3748 qemu_bh_schedule(acb->bh); 3749 } 3750 3751 static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, 3752 int64_t sector_num, 3753 QEMUIOVector *qiov, 3754 int nb_sectors, 3755 BlockDriverCompletionFunc *cb, 3756 void *opaque, 3757 bool is_write) 3758 { 3759 Coroutine *co; 3760 BlockDriverAIOCBCoroutine *acb; 3761 3762 acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque); 3763 acb->req.sector = sector_num; 3764 acb->req.nb_sectors = nb_sectors; 3765 acb->req.qiov = qiov; 3766 acb->is_write = is_write; 3767 3768 co = qemu_coroutine_create(bdrv_co_do_rw); 3769 qemu_coroutine_enter(co, acb); 3770 3771 return &acb->common; 3772 } 3773 3774 static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque) 3775 { 3776 BlockDriverAIOCBCoroutine *acb = opaque; 3777 BlockDriverState *bs = acb->common.bs; 3778 3779 acb->req.error = bdrv_co_flush(bs); 3780 acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); 3781 qemu_bh_schedule(acb->bh); 3782 } 3783 3784 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs, 3785 BlockDriverCompletionFunc *cb, void *opaque) 3786 { 3787 trace_bdrv_aio_flush(bs, opaque); 3788 3789 Coroutine *co; 3790 BlockDriverAIOCBCoroutine *acb; 3791 3792 acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque); 3793 co = qemu_coroutine_create(bdrv_aio_flush_co_entry); 3794 qemu_coroutine_enter(co, acb); 3795 3796 return &acb->common; 3797 } 3798 3799 static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque) 3800 { 3801 BlockDriverAIOCBCoroutine *acb = opaque; 3802 BlockDriverState *bs = acb->common.bs; 3803 3804 acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors); 3805 acb->bh = qemu_bh_new(bdrv_co_em_bh, acb); 3806 qemu_bh_schedule(acb->bh); 3807 } 3808 3809 BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs, 3810 int64_t sector_num, int nb_sectors, 3811 BlockDriverCompletionFunc *cb, void *opaque) 3812 { 3813 Coroutine *co; 3814 BlockDriverAIOCBCoroutine *acb; 3815 3816 trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque); 3817 3818 acb = qemu_aio_get(&bdrv_em_co_aio_pool, bs, cb, opaque); 3819 acb->req.sector = sector_num; 3820 acb->req.nb_sectors = nb_sectors; 3821 co = qemu_coroutine_create(bdrv_aio_discard_co_entry); 3822 qemu_coroutine_enter(co, acb); 3823 3824 return &acb->common; 3825 } 3826 3827 void bdrv_init(void) 3828 { 3829 module_call_init(MODULE_INIT_BLOCK); 3830 } 3831 3832 void bdrv_init_with_whitelist(void) 3833 { 3834 use_bdrv_whitelist = 1; 3835 bdrv_init(); 3836 } 3837 3838 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs, 3839 BlockDriverCompletionFunc *cb, void *opaque) 3840 { 3841 BlockDriverAIOCB *acb; 3842 3843 if (pool->free_aiocb) { 3844 acb = pool->free_aiocb; 3845 pool->free_aiocb = acb->next; 3846 } else { 3847 acb = g_malloc0(pool->aiocb_size); 3848 acb->pool = pool; 3849 } 3850 acb->bs = bs; 3851 acb->cb = cb; 3852 acb->opaque = opaque; 3853 return acb; 3854 } 3855 3856 void qemu_aio_release(void *p) 3857 { 3858 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p; 3859 AIOPool *pool = acb->pool; 3860 acb->next = pool->free_aiocb; 3861 pool->free_aiocb = acb; 3862 } 3863 3864 /**************************************************************/ 3865 /* Coroutine block device emulation */ 3866 3867 typedef struct CoroutineIOCompletion { 3868 Coroutine *coroutine; 3869 int ret; 3870 } CoroutineIOCompletion; 3871 3872 static void bdrv_co_io_em_complete(void *opaque, int ret) 3873 { 3874 CoroutineIOCompletion *co = opaque; 3875 3876 co->ret = ret; 3877 qemu_coroutine_enter(co->coroutine, NULL); 3878 } 3879 3880 static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num, 3881 int nb_sectors, QEMUIOVector *iov, 3882 bool is_write) 3883 { 3884 CoroutineIOCompletion co = { 3885 .coroutine = qemu_coroutine_self(), 3886 }; 3887 BlockDriverAIOCB *acb; 3888 3889 if (is_write) { 3890 acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors, 3891 bdrv_co_io_em_complete, &co); 3892 } else { 3893 acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors, 3894 bdrv_co_io_em_complete, &co); 3895 } 3896 3897 trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb); 3898 if (!acb) { 3899 return -EIO; 3900 } 3901 qemu_coroutine_yield(); 3902 3903 return co.ret; 3904 } 3905 3906 static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, 3907 int64_t sector_num, int nb_sectors, 3908 QEMUIOVector *iov) 3909 { 3910 return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false); 3911 } 3912 3913 static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, 3914 int64_t sector_num, int nb_sectors, 3915 QEMUIOVector *iov) 3916 { 3917 return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true); 3918 } 3919 3920 static void coroutine_fn bdrv_flush_co_entry(void *opaque) 3921 { 3922 RwCo *rwco = opaque; 3923 3924 rwco->ret = bdrv_co_flush(rwco->bs); 3925 } 3926 3927 int coroutine_fn bdrv_co_flush(BlockDriverState *bs) 3928 { 3929 int ret; 3930 3931 if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { 3932 return 0; 3933 } 3934 3935 /* Write back cached data to the OS even with cache=unsafe */ 3936 if (bs->drv->bdrv_co_flush_to_os) { 3937 ret = bs->drv->bdrv_co_flush_to_os(bs); 3938 if (ret < 0) { 3939 return ret; 3940 } 3941 } 3942 3943 /* But don't actually force it to the disk with cache=unsafe */ 3944 if (bs->open_flags & BDRV_O_NO_FLUSH) { 3945 goto flush_parent; 3946 } 3947 3948 if (bs->drv->bdrv_co_flush_to_disk) { 3949 ret = bs->drv->bdrv_co_flush_to_disk(bs); 3950 } else if (bs->drv->bdrv_aio_flush) { 3951 BlockDriverAIOCB *acb; 3952 CoroutineIOCompletion co = { 3953 .coroutine = qemu_coroutine_self(), 3954 }; 3955 3956 acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); 3957 if (acb == NULL) { 3958 ret = -EIO; 3959 } else { 3960 qemu_coroutine_yield(); 3961 ret = co.ret; 3962 } 3963 } else { 3964 /* 3965 * Some block drivers always operate in either writethrough or unsafe 3966 * mode and don't support bdrv_flush therefore. Usually qemu doesn't 3967 * know how the server works (because the behaviour is hardcoded or 3968 * depends on server-side configuration), so we can't ensure that 3969 * everything is safe on disk. Returning an error doesn't work because 3970 * that would break guests even if the server operates in writethrough 3971 * mode. 3972 * 3973 * Let's hope the user knows what he's doing. 3974 */ 3975 ret = 0; 3976 } 3977 if (ret < 0) { 3978 return ret; 3979 } 3980 3981 /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH 3982 * in the case of cache=unsafe, so there are no useless flushes. 3983 */ 3984 flush_parent: 3985 return bdrv_co_flush(bs->file); 3986 } 3987 3988 void bdrv_invalidate_cache(BlockDriverState *bs) 3989 { 3990 if (bs->drv && bs->drv->bdrv_invalidate_cache) { 3991 bs->drv->bdrv_invalidate_cache(bs); 3992 } 3993 } 3994 3995 void bdrv_invalidate_cache_all(void) 3996 { 3997 BlockDriverState *bs; 3998 3999 QTAILQ_FOREACH(bs, &bdrv_states, list) { 4000 bdrv_invalidate_cache(bs); 4001 } 4002 } 4003 4004 void bdrv_clear_incoming_migration_all(void) 4005 { 4006 BlockDriverState *bs; 4007 4008 QTAILQ_FOREACH(bs, &bdrv_states, list) { 4009 bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING); 4010 } 4011 } 4012 4013 int bdrv_flush(BlockDriverState *bs) 4014 { 4015 Coroutine *co; 4016 RwCo rwco = { 4017 .bs = bs, 4018 .ret = NOT_DONE, 4019 }; 4020 4021 if (qemu_in_coroutine()) { 4022 /* Fast-path if already in coroutine context */ 4023 bdrv_flush_co_entry(&rwco); 4024 } else { 4025 co = qemu_coroutine_create(bdrv_flush_co_entry); 4026 qemu_coroutine_enter(co, &rwco); 4027 while (rwco.ret == NOT_DONE) { 4028 qemu_aio_wait(); 4029 } 4030 } 4031 4032 return rwco.ret; 4033 } 4034 4035 static void coroutine_fn bdrv_discard_co_entry(void *opaque) 4036 { 4037 RwCo *rwco = opaque; 4038 4039 rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); 4040 } 4041 4042 int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, 4043 int nb_sectors) 4044 { 4045 if (!bs->drv) { 4046 return -ENOMEDIUM; 4047 } else if (bdrv_check_request(bs, sector_num, nb_sectors)) { 4048 return -EIO; 4049 } else if (bs->read_only) { 4050 return -EROFS; 4051 } else if (bs->drv->bdrv_co_discard) { 4052 return bs->drv->bdrv_co_discard(bs, sector_num, nb_sectors); 4053 } else if (bs->drv->bdrv_aio_discard) { 4054 BlockDriverAIOCB *acb; 4055 CoroutineIOCompletion co = { 4056 .coroutine = qemu_coroutine_self(), 4057 }; 4058 4059 acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors, 4060 bdrv_co_io_em_complete, &co); 4061 if (acb == NULL) { 4062 return -EIO; 4063 } else { 4064 qemu_coroutine_yield(); 4065 return co.ret; 4066 } 4067 } else { 4068 return 0; 4069 } 4070 } 4071 4072 int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) 4073 { 4074 Coroutine *co; 4075 RwCo rwco = { 4076 .bs = bs, 4077 .sector_num = sector_num, 4078 .nb_sectors = nb_sectors, 4079 .ret = NOT_DONE, 4080 }; 4081 4082 if (qemu_in_coroutine()) { 4083 /* Fast-path if already in coroutine context */ 4084 bdrv_discard_co_entry(&rwco); 4085 } else { 4086 co = qemu_coroutine_create(bdrv_discard_co_entry); 4087 qemu_coroutine_enter(co, &rwco); 4088 while (rwco.ret == NOT_DONE) { 4089 qemu_aio_wait(); 4090 } 4091 } 4092 4093 return rwco.ret; 4094 } 4095 4096 /**************************************************************/ 4097 /* removable device support */ 4098 4099 /** 4100 * Return TRUE if the media is present 4101 */ 4102 int bdrv_is_inserted(BlockDriverState *bs) 4103 { 4104 BlockDriver *drv = bs->drv; 4105 4106 if (!drv) 4107 return 0; 4108 if (!drv->bdrv_is_inserted) 4109 return 1; 4110 return drv->bdrv_is_inserted(bs); 4111 } 4112 4113 /** 4114 * Return whether the media changed since the last call to this 4115 * function, or -ENOTSUP if we don't know. Most drivers don't know. 4116 */ 4117 int bdrv_media_changed(BlockDriverState *bs) 4118 { 4119 BlockDriver *drv = bs->drv; 4120 4121 if (drv && drv->bdrv_media_changed) { 4122 return drv->bdrv_media_changed(bs); 4123 } 4124 return -ENOTSUP; 4125 } 4126 4127 /** 4128 * If eject_flag is TRUE, eject the media. Otherwise, close the tray 4129 */ 4130 void bdrv_eject(BlockDriverState *bs, bool eject_flag) 4131 { 4132 BlockDriver *drv = bs->drv; 4133 4134 if (drv && drv->bdrv_eject) { 4135 drv->bdrv_eject(bs, eject_flag); 4136 } 4137 4138 if (bs->device_name[0] != '\0') { 4139 bdrv_emit_qmp_eject_event(bs, eject_flag); 4140 } 4141 } 4142 4143 /** 4144 * Lock or unlock the media (if it is locked, the user won't be able 4145 * to eject it manually). 4146 */ 4147 void bdrv_lock_medium(BlockDriverState *bs, bool locked) 4148 { 4149 BlockDriver *drv = bs->drv; 4150 4151 trace_bdrv_lock_medium(bs, locked); 4152 4153 if (drv && drv->bdrv_lock_medium) { 4154 drv->bdrv_lock_medium(bs, locked); 4155 } 4156 } 4157 4158 /* needed for generic scsi interface */ 4159 4160 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) 4161 { 4162 BlockDriver *drv = bs->drv; 4163 4164 if (drv && drv->bdrv_ioctl) 4165 return drv->bdrv_ioctl(bs, req, buf); 4166 return -ENOTSUP; 4167 } 4168 4169 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, 4170 unsigned long int req, void *buf, 4171 BlockDriverCompletionFunc *cb, void *opaque) 4172 { 4173 BlockDriver *drv = bs->drv; 4174 4175 if (drv && drv->bdrv_aio_ioctl) 4176 return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque); 4177 return NULL; 4178 } 4179 4180 void bdrv_set_buffer_alignment(BlockDriverState *bs, int align) 4181 { 4182 bs->buffer_alignment = align; 4183 } 4184 4185 void *qemu_blockalign(BlockDriverState *bs, size_t size) 4186 { 4187 return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size); 4188 } 4189 4190 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable) 4191 { 4192 int64_t bitmap_size; 4193 4194 bs->dirty_count = 0; 4195 if (enable) { 4196 if (!bs->dirty_bitmap) { 4197 bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) + 4198 BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG - 1; 4199 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * BITS_PER_LONG; 4200 4201 bs->dirty_bitmap = g_new0(unsigned long, bitmap_size); 4202 } 4203 } else { 4204 if (bs->dirty_bitmap) { 4205 g_free(bs->dirty_bitmap); 4206 bs->dirty_bitmap = NULL; 4207 } 4208 } 4209 } 4210 4211 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector) 4212 { 4213 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK; 4214 4215 if (bs->dirty_bitmap && 4216 (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) { 4217 return !!(bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] & 4218 (1UL << (chunk % (sizeof(unsigned long) * 8)))); 4219 } else { 4220 return 0; 4221 } 4222 } 4223 4224 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, 4225 int nr_sectors) 4226 { 4227 set_dirty_bitmap(bs, cur_sector, nr_sectors, 0); 4228 } 4229 4230 int64_t bdrv_get_dirty_count(BlockDriverState *bs) 4231 { 4232 return bs->dirty_count; 4233 } 4234 4235 void bdrv_set_in_use(BlockDriverState *bs, int in_use) 4236 { 4237 assert(bs->in_use != in_use); 4238 bs->in_use = in_use; 4239 } 4240 4241 int bdrv_in_use(BlockDriverState *bs) 4242 { 4243 return bs->in_use; 4244 } 4245 4246 void bdrv_iostatus_enable(BlockDriverState *bs) 4247 { 4248 bs->iostatus_enabled = true; 4249 bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; 4250 } 4251 4252 /* The I/O status is only enabled if the drive explicitly 4253 * enables it _and_ the VM is configured to stop on errors */ 4254 bool bdrv_iostatus_is_enabled(const BlockDriverState *bs) 4255 { 4256 return (bs->iostatus_enabled && 4257 (bs->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC || 4258 bs->on_write_error == BLOCKDEV_ON_ERROR_STOP || 4259 bs->on_read_error == BLOCKDEV_ON_ERROR_STOP)); 4260 } 4261 4262 void bdrv_iostatus_disable(BlockDriverState *bs) 4263 { 4264 bs->iostatus_enabled = false; 4265 } 4266 4267 void bdrv_iostatus_reset(BlockDriverState *bs) 4268 { 4269 if (bdrv_iostatus_is_enabled(bs)) { 4270 bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; 4271 } 4272 } 4273 4274 void bdrv_iostatus_set_err(BlockDriverState *bs, int error) 4275 { 4276 assert(bdrv_iostatus_is_enabled(bs)); 4277 if (bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { 4278 bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : 4279 BLOCK_DEVICE_IO_STATUS_FAILED; 4280 } 4281 } 4282 4283 void 4284 bdrv_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie, int64_t bytes, 4285 enum BlockAcctType type) 4286 { 4287 assert(type < BDRV_MAX_IOTYPE); 4288 4289 cookie->bytes = bytes; 4290 cookie->start_time_ns = get_clock(); 4291 cookie->type = type; 4292 } 4293 4294 void 4295 bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie *cookie) 4296 { 4297 assert(cookie->type < BDRV_MAX_IOTYPE); 4298 4299 bs->nr_bytes[cookie->type] += cookie->bytes; 4300 bs->nr_ops[cookie->type]++; 4301 bs->total_time_ns[cookie->type] += get_clock() - cookie->start_time_ns; 4302 } 4303 4304 int bdrv_img_create(const char *filename, const char *fmt, 4305 const char *base_filename, const char *base_fmt, 4306 char *options, uint64_t img_size, int flags) 4307 { 4308 QEMUOptionParameter *param = NULL, *create_options = NULL; 4309 QEMUOptionParameter *backing_fmt, *backing_file, *size; 4310 BlockDriverState *bs = NULL; 4311 BlockDriver *drv, *proto_drv; 4312 BlockDriver *backing_drv = NULL; 4313 int ret = 0; 4314 4315 /* Find driver and parse its options */ 4316 drv = bdrv_find_format(fmt); 4317 if (!drv) { 4318 error_report("Unknown file format '%s'", fmt); 4319 ret = -EINVAL; 4320 goto out; 4321 } 4322 4323 proto_drv = bdrv_find_protocol(filename); 4324 if (!proto_drv) { 4325 error_report("Unknown protocol '%s'", filename); 4326 ret = -EINVAL; 4327 goto out; 4328 } 4329 4330 create_options = append_option_parameters(create_options, 4331 drv->create_options); 4332 create_options = append_option_parameters(create_options, 4333 proto_drv->create_options); 4334 4335 /* Create parameter list with default values */ 4336 param = parse_option_parameters("", create_options, param); 4337 4338 set_option_parameter_int(param, BLOCK_OPT_SIZE, img_size); 4339 4340 /* Parse -o options */ 4341 if (options) { 4342 param = parse_option_parameters(options, create_options, param); 4343 if (param == NULL) { 4344 error_report("Invalid options for file format '%s'.", fmt); 4345 ret = -EINVAL; 4346 goto out; 4347 } 4348 } 4349 4350 if (base_filename) { 4351 if (set_option_parameter(param, BLOCK_OPT_BACKING_FILE, 4352 base_filename)) { 4353 error_report("Backing file not supported for file format '%s'", 4354 fmt); 4355 ret = -EINVAL; 4356 goto out; 4357 } 4358 } 4359 4360 if (base_fmt) { 4361 if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) { 4362 error_report("Backing file format not supported for file " 4363 "format '%s'", fmt); 4364 ret = -EINVAL; 4365 goto out; 4366 } 4367 } 4368 4369 backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE); 4370 if (backing_file && backing_file->value.s) { 4371 if (!strcmp(filename, backing_file->value.s)) { 4372 error_report("Error: Trying to create an image with the " 4373 "same filename as the backing file"); 4374 ret = -EINVAL; 4375 goto out; 4376 } 4377 } 4378 4379 backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT); 4380 if (backing_fmt && backing_fmt->value.s) { 4381 backing_drv = bdrv_find_format(backing_fmt->value.s); 4382 if (!backing_drv) { 4383 error_report("Unknown backing file format '%s'", 4384 backing_fmt->value.s); 4385 ret = -EINVAL; 4386 goto out; 4387 } 4388 } 4389 4390 // The size for the image must always be specified, with one exception: 4391 // If we are using a backing file, we can obtain the size from there 4392 size = get_option_parameter(param, BLOCK_OPT_SIZE); 4393 if (size && size->value.n == -1) { 4394 if (backing_file && backing_file->value.s) { 4395 uint64_t size; 4396 char buf[32]; 4397 int back_flags; 4398 4399 /* backing files always opened read-only */ 4400 back_flags = 4401 flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); 4402 4403 bs = bdrv_new(""); 4404 4405 ret = bdrv_open(bs, backing_file->value.s, back_flags, backing_drv); 4406 if (ret < 0) { 4407 error_report("Could not open '%s'", backing_file->value.s); 4408 goto out; 4409 } 4410 bdrv_get_geometry(bs, &size); 4411 size *= 512; 4412 4413 snprintf(buf, sizeof(buf), "%" PRId64, size); 4414 set_option_parameter(param, BLOCK_OPT_SIZE, buf); 4415 } else { 4416 error_report("Image creation needs a size parameter"); 4417 ret = -EINVAL; 4418 goto out; 4419 } 4420 } 4421 4422 printf("Formatting '%s', fmt=%s ", filename, fmt); 4423 print_option_parameters(param); 4424 puts(""); 4425 4426 ret = bdrv_create(drv, filename, param); 4427 4428 if (ret < 0) { 4429 if (ret == -ENOTSUP) { 4430 error_report("Formatting or formatting option not supported for " 4431 "file format '%s'", fmt); 4432 } else if (ret == -EFBIG) { 4433 error_report("The image size is too large for file format '%s'", 4434 fmt); 4435 } else { 4436 error_report("%s: error while creating %s: %s", filename, fmt, 4437 strerror(-ret)); 4438 } 4439 } 4440 4441 out: 4442 free_option_parameters(create_options); 4443 free_option_parameters(param); 4444 4445 if (bs) { 4446 bdrv_delete(bs); 4447 } 4448 4449 return ret; 4450 } 4451