1 /* 2 * QEMU Enhanced Disk Format 3 * 4 * Copyright IBM, Corp. 2010 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 8 * Anthony Liguori <aliguori@us.ibm.com> 9 * 10 * This work is licensed under the terms of the GNU LGPL, version 2 or later. 11 * See the COPYING.LIB file in the top-level directory. 12 * 13 */ 14 15 #include "qemu/timer.h" 16 #include "trace.h" 17 #include "qed.h" 18 #include "qapi/qmp/qerror.h" 19 #include "migration/migration.h" 20 21 static void qed_aio_cancel(BlockDriverAIOCB *blockacb) 22 { 23 QEDAIOCB *acb = (QEDAIOCB *)blockacb; 24 bool finished = false; 25 26 /* Wait for the request to finish */ 27 acb->finished = &finished; 28 while (!finished) { 29 qemu_aio_wait(); 30 } 31 } 32 33 static const AIOCBInfo qed_aiocb_info = { 34 .aiocb_size = sizeof(QEDAIOCB), 35 .cancel = qed_aio_cancel, 36 }; 37 38 static int bdrv_qed_probe(const uint8_t *buf, int buf_size, 39 const char *filename) 40 { 41 const QEDHeader *header = (const QEDHeader *)buf; 42 43 if (buf_size < sizeof(*header)) { 44 return 0; 45 } 46 if (le32_to_cpu(header->magic) != QED_MAGIC) { 47 return 0; 48 } 49 return 100; 50 } 51 52 /** 53 * Check whether an image format is raw 54 * 55 * @fmt: Backing file format, may be NULL 56 */ 57 static bool qed_fmt_is_raw(const char *fmt) 58 { 59 return fmt && strcmp(fmt, "raw") == 0; 60 } 61 62 static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu) 63 { 64 cpu->magic = le32_to_cpu(le->magic); 65 cpu->cluster_size = le32_to_cpu(le->cluster_size); 66 cpu->table_size = le32_to_cpu(le->table_size); 67 cpu->header_size = le32_to_cpu(le->header_size); 68 cpu->features = le64_to_cpu(le->features); 69 cpu->compat_features = le64_to_cpu(le->compat_features); 70 cpu->autoclear_features = le64_to_cpu(le->autoclear_features); 71 cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset); 72 cpu->image_size = le64_to_cpu(le->image_size); 73 cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset); 74 cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size); 75 } 76 77 static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le) 78 { 79 le->magic = cpu_to_le32(cpu->magic); 80 le->cluster_size = cpu_to_le32(cpu->cluster_size); 81 le->table_size = cpu_to_le32(cpu->table_size); 82 le->header_size = cpu_to_le32(cpu->header_size); 83 le->features = cpu_to_le64(cpu->features); 84 le->compat_features = cpu_to_le64(cpu->compat_features); 85 le->autoclear_features = cpu_to_le64(cpu->autoclear_features); 86 le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset); 87 le->image_size = cpu_to_le64(cpu->image_size); 88 le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset); 89 le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size); 90 } 91 92 int qed_write_header_sync(BDRVQEDState *s) 93 { 94 QEDHeader le; 95 int ret; 96 97 qed_header_cpu_to_le(&s->header, &le); 98 ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le)); 99 if (ret != sizeof(le)) { 100 return ret; 101 } 102 return 0; 103 } 104 105 typedef struct { 106 GenericCB gencb; 107 BDRVQEDState *s; 108 struct iovec iov; 109 QEMUIOVector qiov; 110 int nsectors; 111 uint8_t *buf; 112 } QEDWriteHeaderCB; 113 114 static void qed_write_header_cb(void *opaque, int ret) 115 { 116 QEDWriteHeaderCB *write_header_cb = opaque; 117 118 qemu_vfree(write_header_cb->buf); 119 gencb_complete(write_header_cb, ret); 120 } 121 122 static void qed_write_header_read_cb(void *opaque, int ret) 123 { 124 QEDWriteHeaderCB *write_header_cb = opaque; 125 BDRVQEDState *s = write_header_cb->s; 126 127 if (ret) { 128 qed_write_header_cb(write_header_cb, ret); 129 return; 130 } 131 132 /* Update header */ 133 qed_header_cpu_to_le(&s->header, (QEDHeader *)write_header_cb->buf); 134 135 bdrv_aio_writev(s->bs->file, 0, &write_header_cb->qiov, 136 write_header_cb->nsectors, qed_write_header_cb, 137 write_header_cb); 138 } 139 140 /** 141 * Update header in-place (does not rewrite backing filename or other strings) 142 * 143 * This function only updates known header fields in-place and does not affect 144 * extra data after the QED header. 145 */ 146 static void qed_write_header(BDRVQEDState *s, BlockDriverCompletionFunc cb, 147 void *opaque) 148 { 149 /* We must write full sectors for O_DIRECT but cannot necessarily generate 150 * the data following the header if an unrecognized compat feature is 151 * active. Therefore, first read the sectors containing the header, update 152 * them, and write back. 153 */ 154 155 int nsectors = (sizeof(QEDHeader) + BDRV_SECTOR_SIZE - 1) / 156 BDRV_SECTOR_SIZE; 157 size_t len = nsectors * BDRV_SECTOR_SIZE; 158 QEDWriteHeaderCB *write_header_cb = gencb_alloc(sizeof(*write_header_cb), 159 cb, opaque); 160 161 write_header_cb->s = s; 162 write_header_cb->nsectors = nsectors; 163 write_header_cb->buf = qemu_blockalign(s->bs, len); 164 write_header_cb->iov.iov_base = write_header_cb->buf; 165 write_header_cb->iov.iov_len = len; 166 qemu_iovec_init_external(&write_header_cb->qiov, &write_header_cb->iov, 1); 167 168 bdrv_aio_readv(s->bs->file, 0, &write_header_cb->qiov, nsectors, 169 qed_write_header_read_cb, write_header_cb); 170 } 171 172 static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size) 173 { 174 uint64_t table_entries; 175 uint64_t l2_size; 176 177 table_entries = (table_size * cluster_size) / sizeof(uint64_t); 178 l2_size = table_entries * cluster_size; 179 180 return l2_size * table_entries; 181 } 182 183 static bool qed_is_cluster_size_valid(uint32_t cluster_size) 184 { 185 if (cluster_size < QED_MIN_CLUSTER_SIZE || 186 cluster_size > QED_MAX_CLUSTER_SIZE) { 187 return false; 188 } 189 if (cluster_size & (cluster_size - 1)) { 190 return false; /* not power of 2 */ 191 } 192 return true; 193 } 194 195 static bool qed_is_table_size_valid(uint32_t table_size) 196 { 197 if (table_size < QED_MIN_TABLE_SIZE || 198 table_size > QED_MAX_TABLE_SIZE) { 199 return false; 200 } 201 if (table_size & (table_size - 1)) { 202 return false; /* not power of 2 */ 203 } 204 return true; 205 } 206 207 static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size, 208 uint32_t table_size) 209 { 210 if (image_size % BDRV_SECTOR_SIZE != 0) { 211 return false; /* not multiple of sector size */ 212 } 213 if (image_size > qed_max_image_size(cluster_size, table_size)) { 214 return false; /* image is too large */ 215 } 216 return true; 217 } 218 219 /** 220 * Read a string of known length from the image file 221 * 222 * @file: Image file 223 * @offset: File offset to start of string, in bytes 224 * @n: String length in bytes 225 * @buf: Destination buffer 226 * @buflen: Destination buffer length in bytes 227 * @ret: 0 on success, -errno on failure 228 * 229 * The string is NUL-terminated. 230 */ 231 static int qed_read_string(BlockDriverState *file, uint64_t offset, size_t n, 232 char *buf, size_t buflen) 233 { 234 int ret; 235 if (n >= buflen) { 236 return -EINVAL; 237 } 238 ret = bdrv_pread(file, offset, buf, n); 239 if (ret < 0) { 240 return ret; 241 } 242 buf[n] = '\0'; 243 return 0; 244 } 245 246 /** 247 * Allocate new clusters 248 * 249 * @s: QED state 250 * @n: Number of contiguous clusters to allocate 251 * @ret: Offset of first allocated cluster 252 * 253 * This function only produces the offset where the new clusters should be 254 * written. It updates BDRVQEDState but does not make any changes to the image 255 * file. 256 */ 257 static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n) 258 { 259 uint64_t offset = s->file_size; 260 s->file_size += n * s->header.cluster_size; 261 return offset; 262 } 263 264 QEDTable *qed_alloc_table(BDRVQEDState *s) 265 { 266 /* Honor O_DIRECT memory alignment requirements */ 267 return qemu_blockalign(s->bs, 268 s->header.cluster_size * s->header.table_size); 269 } 270 271 /** 272 * Allocate a new zeroed L2 table 273 */ 274 static CachedL2Table *qed_new_l2_table(BDRVQEDState *s) 275 { 276 CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); 277 278 l2_table->table = qed_alloc_table(s); 279 l2_table->offset = qed_alloc_clusters(s, s->header.table_size); 280 281 memset(l2_table->table->offsets, 0, 282 s->header.cluster_size * s->header.table_size); 283 return l2_table; 284 } 285 286 static void qed_aio_next_io(void *opaque, int ret); 287 288 static void qed_plug_allocating_write_reqs(BDRVQEDState *s) 289 { 290 assert(!s->allocating_write_reqs_plugged); 291 292 s->allocating_write_reqs_plugged = true; 293 } 294 295 static void qed_unplug_allocating_write_reqs(BDRVQEDState *s) 296 { 297 QEDAIOCB *acb; 298 299 assert(s->allocating_write_reqs_plugged); 300 301 s->allocating_write_reqs_plugged = false; 302 303 acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs); 304 if (acb) { 305 qed_aio_next_io(acb, 0); 306 } 307 } 308 309 static void qed_finish_clear_need_check(void *opaque, int ret) 310 { 311 /* Do nothing */ 312 } 313 314 static void qed_flush_after_clear_need_check(void *opaque, int ret) 315 { 316 BDRVQEDState *s = opaque; 317 318 bdrv_aio_flush(s->bs, qed_finish_clear_need_check, s); 319 320 /* No need to wait until flush completes */ 321 qed_unplug_allocating_write_reqs(s); 322 } 323 324 static void qed_clear_need_check(void *opaque, int ret) 325 { 326 BDRVQEDState *s = opaque; 327 328 if (ret) { 329 qed_unplug_allocating_write_reqs(s); 330 return; 331 } 332 333 s->header.features &= ~QED_F_NEED_CHECK; 334 qed_write_header(s, qed_flush_after_clear_need_check, s); 335 } 336 337 static void qed_need_check_timer_cb(void *opaque) 338 { 339 BDRVQEDState *s = opaque; 340 341 /* The timer should only fire when allocating writes have drained */ 342 assert(!QSIMPLEQ_FIRST(&s->allocating_write_reqs)); 343 344 trace_qed_need_check_timer_cb(s); 345 346 qed_plug_allocating_write_reqs(s); 347 348 /* Ensure writes are on disk before clearing flag */ 349 bdrv_aio_flush(s->bs, qed_clear_need_check, s); 350 } 351 352 static void qed_start_need_check_timer(BDRVQEDState *s) 353 { 354 trace_qed_start_need_check_timer(s); 355 356 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for 357 * migration. 358 */ 359 timer_mod(s->need_check_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 360 get_ticks_per_sec() * QED_NEED_CHECK_TIMEOUT); 361 } 362 363 /* It's okay to call this multiple times or when no timer is started */ 364 static void qed_cancel_need_check_timer(BDRVQEDState *s) 365 { 366 trace_qed_cancel_need_check_timer(s); 367 timer_del(s->need_check_timer); 368 } 369 370 static void bdrv_qed_rebind(BlockDriverState *bs) 371 { 372 BDRVQEDState *s = bs->opaque; 373 s->bs = bs; 374 } 375 376 static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags, 377 Error **errp) 378 { 379 BDRVQEDState *s = bs->opaque; 380 QEDHeader le_header; 381 int64_t file_size; 382 int ret; 383 384 s->bs = bs; 385 QSIMPLEQ_INIT(&s->allocating_write_reqs); 386 387 ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header)); 388 if (ret < 0) { 389 return ret; 390 } 391 qed_header_le_to_cpu(&le_header, &s->header); 392 393 if (s->header.magic != QED_MAGIC) { 394 return -EMEDIUMTYPE; 395 } 396 if (s->header.features & ~QED_FEATURE_MASK) { 397 /* image uses unsupported feature bits */ 398 char buf[64]; 399 snprintf(buf, sizeof(buf), "%" PRIx64, 400 s->header.features & ~QED_FEATURE_MASK); 401 qerror_report(QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, 402 bs->device_name, "QED", buf); 403 return -ENOTSUP; 404 } 405 if (!qed_is_cluster_size_valid(s->header.cluster_size)) { 406 return -EINVAL; 407 } 408 409 /* Round down file size to the last cluster */ 410 file_size = bdrv_getlength(bs->file); 411 if (file_size < 0) { 412 return file_size; 413 } 414 s->file_size = qed_start_of_cluster(s, file_size); 415 416 if (!qed_is_table_size_valid(s->header.table_size)) { 417 return -EINVAL; 418 } 419 if (!qed_is_image_size_valid(s->header.image_size, 420 s->header.cluster_size, 421 s->header.table_size)) { 422 return -EINVAL; 423 } 424 if (!qed_check_table_offset(s, s->header.l1_table_offset)) { 425 return -EINVAL; 426 } 427 428 s->table_nelems = (s->header.cluster_size * s->header.table_size) / 429 sizeof(uint64_t); 430 s->l2_shift = ffs(s->header.cluster_size) - 1; 431 s->l2_mask = s->table_nelems - 1; 432 s->l1_shift = s->l2_shift + ffs(s->table_nelems) - 1; 433 434 if ((s->header.features & QED_F_BACKING_FILE)) { 435 if ((uint64_t)s->header.backing_filename_offset + 436 s->header.backing_filename_size > 437 s->header.cluster_size * s->header.header_size) { 438 return -EINVAL; 439 } 440 441 ret = qed_read_string(bs->file, s->header.backing_filename_offset, 442 s->header.backing_filename_size, bs->backing_file, 443 sizeof(bs->backing_file)); 444 if (ret < 0) { 445 return ret; 446 } 447 448 if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) { 449 pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw"); 450 } 451 } 452 453 /* Reset unknown autoclear feature bits. This is a backwards 454 * compatibility mechanism that allows images to be opened by older 455 * programs, which "knock out" unknown feature bits. When an image is 456 * opened by a newer program again it can detect that the autoclear 457 * feature is no longer valid. 458 */ 459 if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 && 460 !bdrv_is_read_only(bs->file) && !(flags & BDRV_O_INCOMING)) { 461 s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK; 462 463 ret = qed_write_header_sync(s); 464 if (ret) { 465 return ret; 466 } 467 468 /* From here on only known autoclear feature bits are valid */ 469 bdrv_flush(bs->file); 470 } 471 472 s->l1_table = qed_alloc_table(s); 473 qed_init_l2_cache(&s->l2_cache); 474 475 ret = qed_read_l1_table_sync(s); 476 if (ret) { 477 goto out; 478 } 479 480 /* If image was not closed cleanly, check consistency */ 481 if (!(flags & BDRV_O_CHECK) && (s->header.features & QED_F_NEED_CHECK)) { 482 /* Read-only images cannot be fixed. There is no risk of corruption 483 * since write operations are not possible. Therefore, allow 484 * potentially inconsistent images to be opened read-only. This can 485 * aid data recovery from an otherwise inconsistent image. 486 */ 487 if (!bdrv_is_read_only(bs->file) && 488 !(flags & BDRV_O_INCOMING)) { 489 BdrvCheckResult result = {0}; 490 491 ret = qed_check(s, &result, true); 492 if (ret) { 493 goto out; 494 } 495 } 496 } 497 498 s->need_check_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, 499 qed_need_check_timer_cb, s); 500 501 out: 502 if (ret) { 503 qed_free_l2_cache(&s->l2_cache); 504 qemu_vfree(s->l1_table); 505 } 506 return ret; 507 } 508 509 static int bdrv_qed_refresh_limits(BlockDriverState *bs) 510 { 511 BDRVQEDState *s = bs->opaque; 512 513 bs->bl.write_zeroes_alignment = s->header.cluster_size >> BDRV_SECTOR_BITS; 514 515 return 0; 516 } 517 518 /* We have nothing to do for QED reopen, stubs just return 519 * success */ 520 static int bdrv_qed_reopen_prepare(BDRVReopenState *state, 521 BlockReopenQueue *queue, Error **errp) 522 { 523 return 0; 524 } 525 526 static void bdrv_qed_close(BlockDriverState *bs) 527 { 528 BDRVQEDState *s = bs->opaque; 529 530 qed_cancel_need_check_timer(s); 531 timer_free(s->need_check_timer); 532 533 /* Ensure writes reach stable storage */ 534 bdrv_flush(bs->file); 535 536 /* Clean shutdown, no check required on next open */ 537 if (s->header.features & QED_F_NEED_CHECK) { 538 s->header.features &= ~QED_F_NEED_CHECK; 539 qed_write_header_sync(s); 540 } 541 542 qed_free_l2_cache(&s->l2_cache); 543 qemu_vfree(s->l1_table); 544 } 545 546 static int qed_create(const char *filename, uint32_t cluster_size, 547 uint64_t image_size, uint32_t table_size, 548 const char *backing_file, const char *backing_fmt) 549 { 550 QEDHeader header = { 551 .magic = QED_MAGIC, 552 .cluster_size = cluster_size, 553 .table_size = table_size, 554 .header_size = 1, 555 .features = 0, 556 .compat_features = 0, 557 .l1_table_offset = cluster_size, 558 .image_size = image_size, 559 }; 560 QEDHeader le_header; 561 uint8_t *l1_table = NULL; 562 size_t l1_size = header.cluster_size * header.table_size; 563 Error *local_err = NULL; 564 int ret = 0; 565 BlockDriverState *bs = NULL; 566 567 ret = bdrv_create_file(filename, NULL, &local_err); 568 if (ret < 0) { 569 qerror_report_err(local_err); 570 error_free(local_err); 571 return ret; 572 } 573 574 ret = bdrv_file_open(&bs, filename, NULL, NULL, 575 BDRV_O_RDWR | BDRV_O_CACHE_WB, &local_err); 576 if (ret < 0) { 577 qerror_report_err(local_err); 578 error_free(local_err); 579 return ret; 580 } 581 582 /* File must start empty and grow, check truncate is supported */ 583 ret = bdrv_truncate(bs, 0); 584 if (ret < 0) { 585 goto out; 586 } 587 588 if (backing_file) { 589 header.features |= QED_F_BACKING_FILE; 590 header.backing_filename_offset = sizeof(le_header); 591 header.backing_filename_size = strlen(backing_file); 592 593 if (qed_fmt_is_raw(backing_fmt)) { 594 header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 595 } 596 } 597 598 qed_header_cpu_to_le(&header, &le_header); 599 ret = bdrv_pwrite(bs, 0, &le_header, sizeof(le_header)); 600 if (ret < 0) { 601 goto out; 602 } 603 ret = bdrv_pwrite(bs, sizeof(le_header), backing_file, 604 header.backing_filename_size); 605 if (ret < 0) { 606 goto out; 607 } 608 609 l1_table = g_malloc0(l1_size); 610 ret = bdrv_pwrite(bs, header.l1_table_offset, l1_table, l1_size); 611 if (ret < 0) { 612 goto out; 613 } 614 615 ret = 0; /* success */ 616 out: 617 g_free(l1_table); 618 bdrv_unref(bs); 619 return ret; 620 } 621 622 static int bdrv_qed_create(const char *filename, QEMUOptionParameter *options, 623 Error **errp) 624 { 625 uint64_t image_size = 0; 626 uint32_t cluster_size = QED_DEFAULT_CLUSTER_SIZE; 627 uint32_t table_size = QED_DEFAULT_TABLE_SIZE; 628 const char *backing_file = NULL; 629 const char *backing_fmt = NULL; 630 631 while (options && options->name) { 632 if (!strcmp(options->name, BLOCK_OPT_SIZE)) { 633 image_size = options->value.n; 634 } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { 635 backing_file = options->value.s; 636 } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { 637 backing_fmt = options->value.s; 638 } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { 639 if (options->value.n) { 640 cluster_size = options->value.n; 641 } 642 } else if (!strcmp(options->name, BLOCK_OPT_TABLE_SIZE)) { 643 if (options->value.n) { 644 table_size = options->value.n; 645 } 646 } 647 options++; 648 } 649 650 if (!qed_is_cluster_size_valid(cluster_size)) { 651 fprintf(stderr, "QED cluster size must be within range [%u, %u] and power of 2\n", 652 QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE); 653 return -EINVAL; 654 } 655 if (!qed_is_table_size_valid(table_size)) { 656 fprintf(stderr, "QED table size must be within range [%u, %u] and power of 2\n", 657 QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE); 658 return -EINVAL; 659 } 660 if (!qed_is_image_size_valid(image_size, cluster_size, table_size)) { 661 fprintf(stderr, "QED image size must be a non-zero multiple of " 662 "cluster size and less than %" PRIu64 " bytes\n", 663 qed_max_image_size(cluster_size, table_size)); 664 return -EINVAL; 665 } 666 667 return qed_create(filename, cluster_size, image_size, table_size, 668 backing_file, backing_fmt); 669 } 670 671 typedef struct { 672 BlockDriverState *bs; 673 Coroutine *co; 674 uint64_t pos; 675 int64_t status; 676 int *pnum; 677 } QEDIsAllocatedCB; 678 679 static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t len) 680 { 681 QEDIsAllocatedCB *cb = opaque; 682 BDRVQEDState *s = cb->bs->opaque; 683 *cb->pnum = len / BDRV_SECTOR_SIZE; 684 switch (ret) { 685 case QED_CLUSTER_FOUND: 686 offset |= qed_offset_into_cluster(s, cb->pos); 687 cb->status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset; 688 break; 689 case QED_CLUSTER_ZERO: 690 cb->status = BDRV_BLOCK_ZERO; 691 break; 692 case QED_CLUSTER_L2: 693 case QED_CLUSTER_L1: 694 cb->status = 0; 695 break; 696 default: 697 assert(ret < 0); 698 cb->status = ret; 699 break; 700 } 701 702 if (cb->co) { 703 qemu_coroutine_enter(cb->co, NULL); 704 } 705 } 706 707 static int64_t coroutine_fn bdrv_qed_co_get_block_status(BlockDriverState *bs, 708 int64_t sector_num, 709 int nb_sectors, int *pnum) 710 { 711 BDRVQEDState *s = bs->opaque; 712 size_t len = (size_t)nb_sectors * BDRV_SECTOR_SIZE; 713 QEDIsAllocatedCB cb = { 714 .bs = bs, 715 .pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE, 716 .status = BDRV_BLOCK_OFFSET_MASK, 717 .pnum = pnum, 718 }; 719 QEDRequest request = { .l2_table = NULL }; 720 721 qed_find_cluster(s, &request, cb.pos, len, qed_is_allocated_cb, &cb); 722 723 /* Now sleep if the callback wasn't invoked immediately */ 724 while (cb.status == BDRV_BLOCK_OFFSET_MASK) { 725 cb.co = qemu_coroutine_self(); 726 qemu_coroutine_yield(); 727 } 728 729 qed_unref_l2_cache_entry(request.l2_table); 730 731 return cb.status; 732 } 733 734 static int bdrv_qed_make_empty(BlockDriverState *bs) 735 { 736 return -ENOTSUP; 737 } 738 739 static BDRVQEDState *acb_to_s(QEDAIOCB *acb) 740 { 741 return acb->common.bs->opaque; 742 } 743 744 /** 745 * Read from the backing file or zero-fill if no backing file 746 * 747 * @s: QED state 748 * @pos: Byte position in device 749 * @qiov: Destination I/O vector 750 * @cb: Completion function 751 * @opaque: User data for completion function 752 * 753 * This function reads qiov->size bytes starting at pos from the backing file. 754 * If there is no backing file then zeroes are read. 755 */ 756 static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos, 757 QEMUIOVector *qiov, 758 BlockDriverCompletionFunc *cb, void *opaque) 759 { 760 uint64_t backing_length = 0; 761 size_t size; 762 763 /* If there is a backing file, get its length. Treat the absence of a 764 * backing file like a zero length backing file. 765 */ 766 if (s->bs->backing_hd) { 767 int64_t l = bdrv_getlength(s->bs->backing_hd); 768 if (l < 0) { 769 cb(opaque, l); 770 return; 771 } 772 backing_length = l; 773 } 774 775 /* Zero all sectors if reading beyond the end of the backing file */ 776 if (pos >= backing_length || 777 pos + qiov->size > backing_length) { 778 qemu_iovec_memset(qiov, 0, 0, qiov->size); 779 } 780 781 /* Complete now if there are no backing file sectors to read */ 782 if (pos >= backing_length) { 783 cb(opaque, 0); 784 return; 785 } 786 787 /* If the read straddles the end of the backing file, shorten it */ 788 size = MIN((uint64_t)backing_length - pos, qiov->size); 789 790 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); 791 bdrv_aio_readv(s->bs->backing_hd, pos / BDRV_SECTOR_SIZE, 792 qiov, size / BDRV_SECTOR_SIZE, cb, opaque); 793 } 794 795 typedef struct { 796 GenericCB gencb; 797 BDRVQEDState *s; 798 QEMUIOVector qiov; 799 struct iovec iov; 800 uint64_t offset; 801 } CopyFromBackingFileCB; 802 803 static void qed_copy_from_backing_file_cb(void *opaque, int ret) 804 { 805 CopyFromBackingFileCB *copy_cb = opaque; 806 qemu_vfree(copy_cb->iov.iov_base); 807 gencb_complete(©_cb->gencb, ret); 808 } 809 810 static void qed_copy_from_backing_file_write(void *opaque, int ret) 811 { 812 CopyFromBackingFileCB *copy_cb = opaque; 813 BDRVQEDState *s = copy_cb->s; 814 815 if (ret) { 816 qed_copy_from_backing_file_cb(copy_cb, ret); 817 return; 818 } 819 820 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); 821 bdrv_aio_writev(s->bs->file, copy_cb->offset / BDRV_SECTOR_SIZE, 822 ©_cb->qiov, copy_cb->qiov.size / BDRV_SECTOR_SIZE, 823 qed_copy_from_backing_file_cb, copy_cb); 824 } 825 826 /** 827 * Copy data from backing file into the image 828 * 829 * @s: QED state 830 * @pos: Byte position in device 831 * @len: Number of bytes 832 * @offset: Byte offset in image file 833 * @cb: Completion function 834 * @opaque: User data for completion function 835 */ 836 static void qed_copy_from_backing_file(BDRVQEDState *s, uint64_t pos, 837 uint64_t len, uint64_t offset, 838 BlockDriverCompletionFunc *cb, 839 void *opaque) 840 { 841 CopyFromBackingFileCB *copy_cb; 842 843 /* Skip copy entirely if there is no work to do */ 844 if (len == 0) { 845 cb(opaque, 0); 846 return; 847 } 848 849 copy_cb = gencb_alloc(sizeof(*copy_cb), cb, opaque); 850 copy_cb->s = s; 851 copy_cb->offset = offset; 852 copy_cb->iov.iov_base = qemu_blockalign(s->bs, len); 853 copy_cb->iov.iov_len = len; 854 qemu_iovec_init_external(©_cb->qiov, ©_cb->iov, 1); 855 856 qed_read_backing_file(s, pos, ©_cb->qiov, 857 qed_copy_from_backing_file_write, copy_cb); 858 } 859 860 /** 861 * Link one or more contiguous clusters into a table 862 * 863 * @s: QED state 864 * @table: L2 table 865 * @index: First cluster index 866 * @n: Number of contiguous clusters 867 * @cluster: First cluster offset 868 * 869 * The cluster offset may be an allocated byte offset in the image file, the 870 * zero cluster marker, or the unallocated cluster marker. 871 */ 872 static void qed_update_l2_table(BDRVQEDState *s, QEDTable *table, int index, 873 unsigned int n, uint64_t cluster) 874 { 875 int i; 876 for (i = index; i < index + n; i++) { 877 table->offsets[i] = cluster; 878 if (!qed_offset_is_unalloc_cluster(cluster) && 879 !qed_offset_is_zero_cluster(cluster)) { 880 cluster += s->header.cluster_size; 881 } 882 } 883 } 884 885 static void qed_aio_complete_bh(void *opaque) 886 { 887 QEDAIOCB *acb = opaque; 888 BlockDriverCompletionFunc *cb = acb->common.cb; 889 void *user_opaque = acb->common.opaque; 890 int ret = acb->bh_ret; 891 bool *finished = acb->finished; 892 893 qemu_bh_delete(acb->bh); 894 qemu_aio_release(acb); 895 896 /* Invoke callback */ 897 cb(user_opaque, ret); 898 899 /* Signal cancel completion */ 900 if (finished) { 901 *finished = true; 902 } 903 } 904 905 static void qed_aio_complete(QEDAIOCB *acb, int ret) 906 { 907 BDRVQEDState *s = acb_to_s(acb); 908 909 trace_qed_aio_complete(s, acb, ret); 910 911 /* Free resources */ 912 qemu_iovec_destroy(&acb->cur_qiov); 913 qed_unref_l2_cache_entry(acb->request.l2_table); 914 915 /* Free the buffer we may have allocated for zero writes */ 916 if (acb->flags & QED_AIOCB_ZERO) { 917 qemu_vfree(acb->qiov->iov[0].iov_base); 918 acb->qiov->iov[0].iov_base = NULL; 919 } 920 921 /* Arrange for a bh to invoke the completion function */ 922 acb->bh_ret = ret; 923 acb->bh = qemu_bh_new(qed_aio_complete_bh, acb); 924 qemu_bh_schedule(acb->bh); 925 926 /* Start next allocating write request waiting behind this one. Note that 927 * requests enqueue themselves when they first hit an unallocated cluster 928 * but they wait until the entire request is finished before waking up the 929 * next request in the queue. This ensures that we don't cycle through 930 * requests multiple times but rather finish one at a time completely. 931 */ 932 if (acb == QSIMPLEQ_FIRST(&s->allocating_write_reqs)) { 933 QSIMPLEQ_REMOVE_HEAD(&s->allocating_write_reqs, next); 934 acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs); 935 if (acb) { 936 qed_aio_next_io(acb, 0); 937 } else if (s->header.features & QED_F_NEED_CHECK) { 938 qed_start_need_check_timer(s); 939 } 940 } 941 } 942 943 /** 944 * Commit the current L2 table to the cache 945 */ 946 static void qed_commit_l2_update(void *opaque, int ret) 947 { 948 QEDAIOCB *acb = opaque; 949 BDRVQEDState *s = acb_to_s(acb); 950 CachedL2Table *l2_table = acb->request.l2_table; 951 uint64_t l2_offset = l2_table->offset; 952 953 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 954 955 /* This is guaranteed to succeed because we just committed the entry to the 956 * cache. 957 */ 958 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 959 assert(acb->request.l2_table != NULL); 960 961 qed_aio_next_io(opaque, ret); 962 } 963 964 /** 965 * Update L1 table with new L2 table offset and write it out 966 */ 967 static void qed_aio_write_l1_update(void *opaque, int ret) 968 { 969 QEDAIOCB *acb = opaque; 970 BDRVQEDState *s = acb_to_s(acb); 971 int index; 972 973 if (ret) { 974 qed_aio_complete(acb, ret); 975 return; 976 } 977 978 index = qed_l1_index(s, acb->cur_pos); 979 s->l1_table->offsets[index] = acb->request.l2_table->offset; 980 981 qed_write_l1_table(s, index, 1, qed_commit_l2_update, acb); 982 } 983 984 /** 985 * Update L2 table with new cluster offsets and write them out 986 */ 987 static void qed_aio_write_l2_update(QEDAIOCB *acb, int ret, uint64_t offset) 988 { 989 BDRVQEDState *s = acb_to_s(acb); 990 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1; 991 int index; 992 993 if (ret) { 994 goto err; 995 } 996 997 if (need_alloc) { 998 qed_unref_l2_cache_entry(acb->request.l2_table); 999 acb->request.l2_table = qed_new_l2_table(s); 1000 } 1001 1002 index = qed_l2_index(s, acb->cur_pos); 1003 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, 1004 offset); 1005 1006 if (need_alloc) { 1007 /* Write out the whole new L2 table */ 1008 qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true, 1009 qed_aio_write_l1_update, acb); 1010 } else { 1011 /* Write out only the updated part of the L2 table */ 1012 qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, false, 1013 qed_aio_next_io, acb); 1014 } 1015 return; 1016 1017 err: 1018 qed_aio_complete(acb, ret); 1019 } 1020 1021 static void qed_aio_write_l2_update_cb(void *opaque, int ret) 1022 { 1023 QEDAIOCB *acb = opaque; 1024 qed_aio_write_l2_update(acb, ret, acb->cur_cluster); 1025 } 1026 1027 /** 1028 * Flush new data clusters before updating the L2 table 1029 * 1030 * This flush is necessary when a backing file is in use. A crash during an 1031 * allocating write could result in empty clusters in the image. If the write 1032 * only touched a subregion of the cluster, then backing image sectors have 1033 * been lost in the untouched region. The solution is to flush after writing a 1034 * new data cluster and before updating the L2 table. 1035 */ 1036 static void qed_aio_write_flush_before_l2_update(void *opaque, int ret) 1037 { 1038 QEDAIOCB *acb = opaque; 1039 BDRVQEDState *s = acb_to_s(acb); 1040 1041 if (!bdrv_aio_flush(s->bs->file, qed_aio_write_l2_update_cb, opaque)) { 1042 qed_aio_complete(acb, -EIO); 1043 } 1044 } 1045 1046 /** 1047 * Write data to the image file 1048 */ 1049 static void qed_aio_write_main(void *opaque, int ret) 1050 { 1051 QEDAIOCB *acb = opaque; 1052 BDRVQEDState *s = acb_to_s(acb); 1053 uint64_t offset = acb->cur_cluster + 1054 qed_offset_into_cluster(s, acb->cur_pos); 1055 BlockDriverCompletionFunc *next_fn; 1056 1057 trace_qed_aio_write_main(s, acb, ret, offset, acb->cur_qiov.size); 1058 1059 if (ret) { 1060 qed_aio_complete(acb, ret); 1061 return; 1062 } 1063 1064 if (acb->find_cluster_ret == QED_CLUSTER_FOUND) { 1065 next_fn = qed_aio_next_io; 1066 } else { 1067 if (s->bs->backing_hd) { 1068 next_fn = qed_aio_write_flush_before_l2_update; 1069 } else { 1070 next_fn = qed_aio_write_l2_update_cb; 1071 } 1072 } 1073 1074 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); 1075 bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE, 1076 &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE, 1077 next_fn, acb); 1078 } 1079 1080 /** 1081 * Populate back untouched region of new data cluster 1082 */ 1083 static void qed_aio_write_postfill(void *opaque, int ret) 1084 { 1085 QEDAIOCB *acb = opaque; 1086 BDRVQEDState *s = acb_to_s(acb); 1087 uint64_t start = acb->cur_pos + acb->cur_qiov.size; 1088 uint64_t len = 1089 qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start; 1090 uint64_t offset = acb->cur_cluster + 1091 qed_offset_into_cluster(s, acb->cur_pos) + 1092 acb->cur_qiov.size; 1093 1094 if (ret) { 1095 qed_aio_complete(acb, ret); 1096 return; 1097 } 1098 1099 trace_qed_aio_write_postfill(s, acb, start, len, offset); 1100 qed_copy_from_backing_file(s, start, len, offset, 1101 qed_aio_write_main, acb); 1102 } 1103 1104 /** 1105 * Populate front untouched region of new data cluster 1106 */ 1107 static void qed_aio_write_prefill(void *opaque, int ret) 1108 { 1109 QEDAIOCB *acb = opaque; 1110 BDRVQEDState *s = acb_to_s(acb); 1111 uint64_t start = qed_start_of_cluster(s, acb->cur_pos); 1112 uint64_t len = qed_offset_into_cluster(s, acb->cur_pos); 1113 1114 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); 1115 qed_copy_from_backing_file(s, start, len, acb->cur_cluster, 1116 qed_aio_write_postfill, acb); 1117 } 1118 1119 /** 1120 * Check if the QED_F_NEED_CHECK bit should be set during allocating write 1121 */ 1122 static bool qed_should_set_need_check(BDRVQEDState *s) 1123 { 1124 /* The flush before L2 update path ensures consistency */ 1125 if (s->bs->backing_hd) { 1126 return false; 1127 } 1128 1129 return !(s->header.features & QED_F_NEED_CHECK); 1130 } 1131 1132 static void qed_aio_write_zero_cluster(void *opaque, int ret) 1133 { 1134 QEDAIOCB *acb = opaque; 1135 1136 if (ret) { 1137 qed_aio_complete(acb, ret); 1138 return; 1139 } 1140 1141 qed_aio_write_l2_update(acb, 0, 1); 1142 } 1143 1144 /** 1145 * Write new data cluster 1146 * 1147 * @acb: Write request 1148 * @len: Length in bytes 1149 * 1150 * This path is taken when writing to previously unallocated clusters. 1151 */ 1152 static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 1153 { 1154 BDRVQEDState *s = acb_to_s(acb); 1155 BlockDriverCompletionFunc *cb; 1156 1157 /* Cancel timer when the first allocating request comes in */ 1158 if (QSIMPLEQ_EMPTY(&s->allocating_write_reqs)) { 1159 qed_cancel_need_check_timer(s); 1160 } 1161 1162 /* Freeze this request if another allocating write is in progress */ 1163 if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs)) { 1164 QSIMPLEQ_INSERT_TAIL(&s->allocating_write_reqs, acb, next); 1165 } 1166 if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs) || 1167 s->allocating_write_reqs_plugged) { 1168 return; /* wait for existing request to finish */ 1169 } 1170 1171 acb->cur_nclusters = qed_bytes_to_clusters(s, 1172 qed_offset_into_cluster(s, acb->cur_pos) + len); 1173 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1174 1175 if (acb->flags & QED_AIOCB_ZERO) { 1176 /* Skip ahead if the clusters are already zero */ 1177 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) { 1178 qed_aio_next_io(acb, 0); 1179 return; 1180 } 1181 1182 cb = qed_aio_write_zero_cluster; 1183 } else { 1184 cb = qed_aio_write_prefill; 1185 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); 1186 } 1187 1188 if (qed_should_set_need_check(s)) { 1189 s->header.features |= QED_F_NEED_CHECK; 1190 qed_write_header(s, cb, acb); 1191 } else { 1192 cb(acb, 0); 1193 } 1194 } 1195 1196 /** 1197 * Write data cluster in place 1198 * 1199 * @acb: Write request 1200 * @offset: Cluster offset in bytes 1201 * @len: Length in bytes 1202 * 1203 * This path is taken when writing to already allocated clusters. 1204 */ 1205 static void qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, size_t len) 1206 { 1207 /* Allocate buffer for zero writes */ 1208 if (acb->flags & QED_AIOCB_ZERO) { 1209 struct iovec *iov = acb->qiov->iov; 1210 1211 if (!iov->iov_base) { 1212 iov->iov_base = qemu_blockalign(acb->common.bs, iov->iov_len); 1213 memset(iov->iov_base, 0, iov->iov_len); 1214 } 1215 } 1216 1217 /* Calculate the I/O vector */ 1218 acb->cur_cluster = offset; 1219 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1220 1221 /* Do the actual write */ 1222 qed_aio_write_main(acb, 0); 1223 } 1224 1225 /** 1226 * Write data cluster 1227 * 1228 * @opaque: Write request 1229 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1, 1230 * or -errno 1231 * @offset: Cluster offset in bytes 1232 * @len: Length in bytes 1233 * 1234 * Callback from qed_find_cluster(). 1235 */ 1236 static void qed_aio_write_data(void *opaque, int ret, 1237 uint64_t offset, size_t len) 1238 { 1239 QEDAIOCB *acb = opaque; 1240 1241 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); 1242 1243 acb->find_cluster_ret = ret; 1244 1245 switch (ret) { 1246 case QED_CLUSTER_FOUND: 1247 qed_aio_write_inplace(acb, offset, len); 1248 break; 1249 1250 case QED_CLUSTER_L2: 1251 case QED_CLUSTER_L1: 1252 case QED_CLUSTER_ZERO: 1253 qed_aio_write_alloc(acb, len); 1254 break; 1255 1256 default: 1257 qed_aio_complete(acb, ret); 1258 break; 1259 } 1260 } 1261 1262 /** 1263 * Read data cluster 1264 * 1265 * @opaque: Read request 1266 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1, 1267 * or -errno 1268 * @offset: Cluster offset in bytes 1269 * @len: Length in bytes 1270 * 1271 * Callback from qed_find_cluster(). 1272 */ 1273 static void qed_aio_read_data(void *opaque, int ret, 1274 uint64_t offset, size_t len) 1275 { 1276 QEDAIOCB *acb = opaque; 1277 BDRVQEDState *s = acb_to_s(acb); 1278 BlockDriverState *bs = acb->common.bs; 1279 1280 /* Adjust offset into cluster */ 1281 offset += qed_offset_into_cluster(s, acb->cur_pos); 1282 1283 trace_qed_aio_read_data(s, acb, ret, offset, len); 1284 1285 if (ret < 0) { 1286 goto err; 1287 } 1288 1289 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1290 1291 /* Handle zero cluster and backing file reads */ 1292 if (ret == QED_CLUSTER_ZERO) { 1293 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size); 1294 qed_aio_next_io(acb, 0); 1295 return; 1296 } else if (ret != QED_CLUSTER_FOUND) { 1297 qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov, 1298 qed_aio_next_io, acb); 1299 return; 1300 } 1301 1302 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 1303 bdrv_aio_readv(bs->file, offset / BDRV_SECTOR_SIZE, 1304 &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE, 1305 qed_aio_next_io, acb); 1306 return; 1307 1308 err: 1309 qed_aio_complete(acb, ret); 1310 } 1311 1312 /** 1313 * Begin next I/O or complete the request 1314 */ 1315 static void qed_aio_next_io(void *opaque, int ret) 1316 { 1317 QEDAIOCB *acb = opaque; 1318 BDRVQEDState *s = acb_to_s(acb); 1319 QEDFindClusterFunc *io_fn = (acb->flags & QED_AIOCB_WRITE) ? 1320 qed_aio_write_data : qed_aio_read_data; 1321 1322 trace_qed_aio_next_io(s, acb, ret, acb->cur_pos + acb->cur_qiov.size); 1323 1324 /* Handle I/O error */ 1325 if (ret) { 1326 qed_aio_complete(acb, ret); 1327 return; 1328 } 1329 1330 acb->qiov_offset += acb->cur_qiov.size; 1331 acb->cur_pos += acb->cur_qiov.size; 1332 qemu_iovec_reset(&acb->cur_qiov); 1333 1334 /* Complete request */ 1335 if (acb->cur_pos >= acb->end_pos) { 1336 qed_aio_complete(acb, 0); 1337 return; 1338 } 1339 1340 /* Find next cluster and start I/O */ 1341 qed_find_cluster(s, &acb->request, 1342 acb->cur_pos, acb->end_pos - acb->cur_pos, 1343 io_fn, acb); 1344 } 1345 1346 static BlockDriverAIOCB *qed_aio_setup(BlockDriverState *bs, 1347 int64_t sector_num, 1348 QEMUIOVector *qiov, int nb_sectors, 1349 BlockDriverCompletionFunc *cb, 1350 void *opaque, int flags) 1351 { 1352 QEDAIOCB *acb = qemu_aio_get(&qed_aiocb_info, bs, cb, opaque); 1353 1354 trace_qed_aio_setup(bs->opaque, acb, sector_num, nb_sectors, 1355 opaque, flags); 1356 1357 acb->flags = flags; 1358 acb->finished = NULL; 1359 acb->qiov = qiov; 1360 acb->qiov_offset = 0; 1361 acb->cur_pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE; 1362 acb->end_pos = acb->cur_pos + nb_sectors * BDRV_SECTOR_SIZE; 1363 acb->request.l2_table = NULL; 1364 qemu_iovec_init(&acb->cur_qiov, qiov->niov); 1365 1366 /* Start request */ 1367 qed_aio_next_io(acb, 0); 1368 return &acb->common; 1369 } 1370 1371 static BlockDriverAIOCB *bdrv_qed_aio_readv(BlockDriverState *bs, 1372 int64_t sector_num, 1373 QEMUIOVector *qiov, int nb_sectors, 1374 BlockDriverCompletionFunc *cb, 1375 void *opaque) 1376 { 1377 return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); 1378 } 1379 1380 static BlockDriverAIOCB *bdrv_qed_aio_writev(BlockDriverState *bs, 1381 int64_t sector_num, 1382 QEMUIOVector *qiov, int nb_sectors, 1383 BlockDriverCompletionFunc *cb, 1384 void *opaque) 1385 { 1386 return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, 1387 opaque, QED_AIOCB_WRITE); 1388 } 1389 1390 typedef struct { 1391 Coroutine *co; 1392 int ret; 1393 bool done; 1394 } QEDWriteZeroesCB; 1395 1396 static void coroutine_fn qed_co_write_zeroes_cb(void *opaque, int ret) 1397 { 1398 QEDWriteZeroesCB *cb = opaque; 1399 1400 cb->done = true; 1401 cb->ret = ret; 1402 if (cb->co) { 1403 qemu_coroutine_enter(cb->co, NULL); 1404 } 1405 } 1406 1407 static int coroutine_fn bdrv_qed_co_write_zeroes(BlockDriverState *bs, 1408 int64_t sector_num, 1409 int nb_sectors, 1410 BdrvRequestFlags flags) 1411 { 1412 BlockDriverAIOCB *blockacb; 1413 BDRVQEDState *s = bs->opaque; 1414 QEDWriteZeroesCB cb = { .done = false }; 1415 QEMUIOVector qiov; 1416 struct iovec iov; 1417 1418 /* Refuse if there are untouched backing file sectors */ 1419 if (bs->backing_hd) { 1420 if (qed_offset_into_cluster(s, sector_num * BDRV_SECTOR_SIZE) != 0) { 1421 return -ENOTSUP; 1422 } 1423 if (qed_offset_into_cluster(s, nb_sectors * BDRV_SECTOR_SIZE) != 0) { 1424 return -ENOTSUP; 1425 } 1426 } 1427 1428 /* Zero writes start without an I/O buffer. If a buffer becomes necessary 1429 * then it will be allocated during request processing. 1430 */ 1431 iov.iov_base = NULL, 1432 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE, 1433 1434 qemu_iovec_init_external(&qiov, &iov, 1); 1435 blockacb = qed_aio_setup(bs, sector_num, &qiov, nb_sectors, 1436 qed_co_write_zeroes_cb, &cb, 1437 QED_AIOCB_WRITE | QED_AIOCB_ZERO); 1438 if (!blockacb) { 1439 return -EIO; 1440 } 1441 if (!cb.done) { 1442 cb.co = qemu_coroutine_self(); 1443 qemu_coroutine_yield(); 1444 } 1445 assert(cb.done); 1446 return cb.ret; 1447 } 1448 1449 static int bdrv_qed_truncate(BlockDriverState *bs, int64_t offset) 1450 { 1451 BDRVQEDState *s = bs->opaque; 1452 uint64_t old_image_size; 1453 int ret; 1454 1455 if (!qed_is_image_size_valid(offset, s->header.cluster_size, 1456 s->header.table_size)) { 1457 return -EINVAL; 1458 } 1459 1460 /* Shrinking is currently not supported */ 1461 if ((uint64_t)offset < s->header.image_size) { 1462 return -ENOTSUP; 1463 } 1464 1465 old_image_size = s->header.image_size; 1466 s->header.image_size = offset; 1467 ret = qed_write_header_sync(s); 1468 if (ret < 0) { 1469 s->header.image_size = old_image_size; 1470 } 1471 return ret; 1472 } 1473 1474 static int64_t bdrv_qed_getlength(BlockDriverState *bs) 1475 { 1476 BDRVQEDState *s = bs->opaque; 1477 return s->header.image_size; 1478 } 1479 1480 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1481 { 1482 BDRVQEDState *s = bs->opaque; 1483 1484 memset(bdi, 0, sizeof(*bdi)); 1485 bdi->cluster_size = s->header.cluster_size; 1486 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK; 1487 bdi->unallocated_blocks_are_zero = true; 1488 bdi->can_write_zeroes_with_unmap = true; 1489 return 0; 1490 } 1491 1492 static int bdrv_qed_change_backing_file(BlockDriverState *bs, 1493 const char *backing_file, 1494 const char *backing_fmt) 1495 { 1496 BDRVQEDState *s = bs->opaque; 1497 QEDHeader new_header, le_header; 1498 void *buffer; 1499 size_t buffer_len, backing_file_len; 1500 int ret; 1501 1502 /* Refuse to set backing filename if unknown compat feature bits are 1503 * active. If the image uses an unknown compat feature then we may not 1504 * know the layout of data following the header structure and cannot safely 1505 * add a new string. 1506 */ 1507 if (backing_file && (s->header.compat_features & 1508 ~QED_COMPAT_FEATURE_MASK)) { 1509 return -ENOTSUP; 1510 } 1511 1512 memcpy(&new_header, &s->header, sizeof(new_header)); 1513 1514 new_header.features &= ~(QED_F_BACKING_FILE | 1515 QED_F_BACKING_FORMAT_NO_PROBE); 1516 1517 /* Adjust feature flags */ 1518 if (backing_file) { 1519 new_header.features |= QED_F_BACKING_FILE; 1520 1521 if (qed_fmt_is_raw(backing_fmt)) { 1522 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 1523 } 1524 } 1525 1526 /* Calculate new header size */ 1527 backing_file_len = 0; 1528 1529 if (backing_file) { 1530 backing_file_len = strlen(backing_file); 1531 } 1532 1533 buffer_len = sizeof(new_header); 1534 new_header.backing_filename_offset = buffer_len; 1535 new_header.backing_filename_size = backing_file_len; 1536 buffer_len += backing_file_len; 1537 1538 /* Make sure we can rewrite header without failing */ 1539 if (buffer_len > new_header.header_size * new_header.cluster_size) { 1540 return -ENOSPC; 1541 } 1542 1543 /* Prepare new header */ 1544 buffer = g_malloc(buffer_len); 1545 1546 qed_header_cpu_to_le(&new_header, &le_header); 1547 memcpy(buffer, &le_header, sizeof(le_header)); 1548 buffer_len = sizeof(le_header); 1549 1550 if (backing_file) { 1551 memcpy(buffer + buffer_len, backing_file, backing_file_len); 1552 buffer_len += backing_file_len; 1553 } 1554 1555 /* Write new header */ 1556 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len); 1557 g_free(buffer); 1558 if (ret == 0) { 1559 memcpy(&s->header, &new_header, sizeof(new_header)); 1560 } 1561 return ret; 1562 } 1563 1564 static void bdrv_qed_invalidate_cache(BlockDriverState *bs) 1565 { 1566 BDRVQEDState *s = bs->opaque; 1567 1568 bdrv_qed_close(bs); 1569 memset(s, 0, sizeof(BDRVQEDState)); 1570 bdrv_qed_open(bs, NULL, bs->open_flags, NULL); 1571 } 1572 1573 static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result, 1574 BdrvCheckMode fix) 1575 { 1576 BDRVQEDState *s = bs->opaque; 1577 1578 return qed_check(s, result, !!fix); 1579 } 1580 1581 static QEMUOptionParameter qed_create_options[] = { 1582 { 1583 .name = BLOCK_OPT_SIZE, 1584 .type = OPT_SIZE, 1585 .help = "Virtual disk size (in bytes)" 1586 }, { 1587 .name = BLOCK_OPT_BACKING_FILE, 1588 .type = OPT_STRING, 1589 .help = "File name of a base image" 1590 }, { 1591 .name = BLOCK_OPT_BACKING_FMT, 1592 .type = OPT_STRING, 1593 .help = "Image format of the base image" 1594 }, { 1595 .name = BLOCK_OPT_CLUSTER_SIZE, 1596 .type = OPT_SIZE, 1597 .help = "Cluster size (in bytes)", 1598 .value = { .n = QED_DEFAULT_CLUSTER_SIZE }, 1599 }, { 1600 .name = BLOCK_OPT_TABLE_SIZE, 1601 .type = OPT_SIZE, 1602 .help = "L1/L2 table size (in clusters)" 1603 }, 1604 { /* end of list */ } 1605 }; 1606 1607 static BlockDriver bdrv_qed = { 1608 .format_name = "qed", 1609 .instance_size = sizeof(BDRVQEDState), 1610 .create_options = qed_create_options, 1611 1612 .bdrv_probe = bdrv_qed_probe, 1613 .bdrv_rebind = bdrv_qed_rebind, 1614 .bdrv_open = bdrv_qed_open, 1615 .bdrv_close = bdrv_qed_close, 1616 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare, 1617 .bdrv_create = bdrv_qed_create, 1618 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1619 .bdrv_co_get_block_status = bdrv_qed_co_get_block_status, 1620 .bdrv_make_empty = bdrv_qed_make_empty, 1621 .bdrv_aio_readv = bdrv_qed_aio_readv, 1622 .bdrv_aio_writev = bdrv_qed_aio_writev, 1623 .bdrv_co_write_zeroes = bdrv_qed_co_write_zeroes, 1624 .bdrv_truncate = bdrv_qed_truncate, 1625 .bdrv_getlength = bdrv_qed_getlength, 1626 .bdrv_get_info = bdrv_qed_get_info, 1627 .bdrv_refresh_limits = bdrv_qed_refresh_limits, 1628 .bdrv_change_backing_file = bdrv_qed_change_backing_file, 1629 .bdrv_invalidate_cache = bdrv_qed_invalidate_cache, 1630 .bdrv_check = bdrv_qed_check, 1631 }; 1632 1633 static void bdrv_qed_init(void) 1634 { 1635 bdrv_register(&bdrv_qed); 1636 } 1637 1638 block_init(bdrv_qed_init); 1639