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 AioContext *aio_context = bdrv_get_aio_context(blockacb->bs); 25 bool finished = false; 26 27 /* Wait for the request to finish */ 28 acb->finished = &finished; 29 while (!finished) { 30 aio_poll(aio_context, true); 31 } 32 } 33 34 static const AIOCBInfo qed_aiocb_info = { 35 .aiocb_size = sizeof(QEDAIOCB), 36 .cancel = qed_aio_cancel, 37 }; 38 39 static int bdrv_qed_probe(const uint8_t *buf, int buf_size, 40 const char *filename) 41 { 42 const QEDHeader *header = (const QEDHeader *)buf; 43 44 if (buf_size < sizeof(*header)) { 45 return 0; 46 } 47 if (le32_to_cpu(header->magic) != QED_MAGIC) { 48 return 0; 49 } 50 return 100; 51 } 52 53 /** 54 * Check whether an image format is raw 55 * 56 * @fmt: Backing file format, may be NULL 57 */ 58 static bool qed_fmt_is_raw(const char *fmt) 59 { 60 return fmt && strcmp(fmt, "raw") == 0; 61 } 62 63 static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu) 64 { 65 cpu->magic = le32_to_cpu(le->magic); 66 cpu->cluster_size = le32_to_cpu(le->cluster_size); 67 cpu->table_size = le32_to_cpu(le->table_size); 68 cpu->header_size = le32_to_cpu(le->header_size); 69 cpu->features = le64_to_cpu(le->features); 70 cpu->compat_features = le64_to_cpu(le->compat_features); 71 cpu->autoclear_features = le64_to_cpu(le->autoclear_features); 72 cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset); 73 cpu->image_size = le64_to_cpu(le->image_size); 74 cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset); 75 cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size); 76 } 77 78 static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le) 79 { 80 le->magic = cpu_to_le32(cpu->magic); 81 le->cluster_size = cpu_to_le32(cpu->cluster_size); 82 le->table_size = cpu_to_le32(cpu->table_size); 83 le->header_size = cpu_to_le32(cpu->header_size); 84 le->features = cpu_to_le64(cpu->features); 85 le->compat_features = cpu_to_le64(cpu->compat_features); 86 le->autoclear_features = cpu_to_le64(cpu->autoclear_features); 87 le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset); 88 le->image_size = cpu_to_le64(cpu->image_size); 89 le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset); 90 le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size); 91 } 92 93 int qed_write_header_sync(BDRVQEDState *s) 94 { 95 QEDHeader le; 96 int ret; 97 98 qed_header_cpu_to_le(&s->header, &le); 99 ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le)); 100 if (ret != sizeof(le)) { 101 return ret; 102 } 103 return 0; 104 } 105 106 typedef struct { 107 GenericCB gencb; 108 BDRVQEDState *s; 109 struct iovec iov; 110 QEMUIOVector qiov; 111 int nsectors; 112 uint8_t *buf; 113 } QEDWriteHeaderCB; 114 115 static void qed_write_header_cb(void *opaque, int ret) 116 { 117 QEDWriteHeaderCB *write_header_cb = opaque; 118 119 qemu_vfree(write_header_cb->buf); 120 gencb_complete(write_header_cb, ret); 121 } 122 123 static void qed_write_header_read_cb(void *opaque, int ret) 124 { 125 QEDWriteHeaderCB *write_header_cb = opaque; 126 BDRVQEDState *s = write_header_cb->s; 127 128 if (ret) { 129 qed_write_header_cb(write_header_cb, ret); 130 return; 131 } 132 133 /* Update header */ 134 qed_header_cpu_to_le(&s->header, (QEDHeader *)write_header_cb->buf); 135 136 bdrv_aio_writev(s->bs->file, 0, &write_header_cb->qiov, 137 write_header_cb->nsectors, qed_write_header_cb, 138 write_header_cb); 139 } 140 141 /** 142 * Update header in-place (does not rewrite backing filename or other strings) 143 * 144 * This function only updates known header fields in-place and does not affect 145 * extra data after the QED header. 146 */ 147 static void qed_write_header(BDRVQEDState *s, BlockDriverCompletionFunc cb, 148 void *opaque) 149 { 150 /* We must write full sectors for O_DIRECT but cannot necessarily generate 151 * the data following the header if an unrecognized compat feature is 152 * active. Therefore, first read the sectors containing the header, update 153 * them, and write back. 154 */ 155 156 int nsectors = (sizeof(QEDHeader) + BDRV_SECTOR_SIZE - 1) / 157 BDRV_SECTOR_SIZE; 158 size_t len = nsectors * BDRV_SECTOR_SIZE; 159 QEDWriteHeaderCB *write_header_cb = gencb_alloc(sizeof(*write_header_cb), 160 cb, opaque); 161 162 write_header_cb->s = s; 163 write_header_cb->nsectors = nsectors; 164 write_header_cb->buf = qemu_blockalign(s->bs, len); 165 write_header_cb->iov.iov_base = write_header_cb->buf; 166 write_header_cb->iov.iov_len = len; 167 qemu_iovec_init_external(&write_header_cb->qiov, &write_header_cb->iov, 1); 168 169 bdrv_aio_readv(s->bs->file, 0, &write_header_cb->qiov, nsectors, 170 qed_write_header_read_cb, write_header_cb); 171 } 172 173 static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size) 174 { 175 uint64_t table_entries; 176 uint64_t l2_size; 177 178 table_entries = (table_size * cluster_size) / sizeof(uint64_t); 179 l2_size = table_entries * cluster_size; 180 181 return l2_size * table_entries; 182 } 183 184 static bool qed_is_cluster_size_valid(uint32_t cluster_size) 185 { 186 if (cluster_size < QED_MIN_CLUSTER_SIZE || 187 cluster_size > QED_MAX_CLUSTER_SIZE) { 188 return false; 189 } 190 if (cluster_size & (cluster_size - 1)) { 191 return false; /* not power of 2 */ 192 } 193 return true; 194 } 195 196 static bool qed_is_table_size_valid(uint32_t table_size) 197 { 198 if (table_size < QED_MIN_TABLE_SIZE || 199 table_size > QED_MAX_TABLE_SIZE) { 200 return false; 201 } 202 if (table_size & (table_size - 1)) { 203 return false; /* not power of 2 */ 204 } 205 return true; 206 } 207 208 static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size, 209 uint32_t table_size) 210 { 211 if (image_size % BDRV_SECTOR_SIZE != 0) { 212 return false; /* not multiple of sector size */ 213 } 214 if (image_size > qed_max_image_size(cluster_size, table_size)) { 215 return false; /* image is too large */ 216 } 217 return true; 218 } 219 220 /** 221 * Read a string of known length from the image file 222 * 223 * @file: Image file 224 * @offset: File offset to start of string, in bytes 225 * @n: String length in bytes 226 * @buf: Destination buffer 227 * @buflen: Destination buffer length in bytes 228 * @ret: 0 on success, -errno on failure 229 * 230 * The string is NUL-terminated. 231 */ 232 static int qed_read_string(BlockDriverState *file, uint64_t offset, size_t n, 233 char *buf, size_t buflen) 234 { 235 int ret; 236 if (n >= buflen) { 237 return -EINVAL; 238 } 239 ret = bdrv_pread(file, offset, buf, n); 240 if (ret < 0) { 241 return ret; 242 } 243 buf[n] = '\0'; 244 return 0; 245 } 246 247 /** 248 * Allocate new clusters 249 * 250 * @s: QED state 251 * @n: Number of contiguous clusters to allocate 252 * @ret: Offset of first allocated cluster 253 * 254 * This function only produces the offset where the new clusters should be 255 * written. It updates BDRVQEDState but does not make any changes to the image 256 * file. 257 */ 258 static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n) 259 { 260 uint64_t offset = s->file_size; 261 s->file_size += n * s->header.cluster_size; 262 return offset; 263 } 264 265 QEDTable *qed_alloc_table(BDRVQEDState *s) 266 { 267 /* Honor O_DIRECT memory alignment requirements */ 268 return qemu_blockalign(s->bs, 269 s->header.cluster_size * s->header.table_size); 270 } 271 272 /** 273 * Allocate a new zeroed L2 table 274 */ 275 static CachedL2Table *qed_new_l2_table(BDRVQEDState *s) 276 { 277 CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); 278 279 l2_table->table = qed_alloc_table(s); 280 l2_table->offset = qed_alloc_clusters(s, s->header.table_size); 281 282 memset(l2_table->table->offsets, 0, 283 s->header.cluster_size * s->header.table_size); 284 return l2_table; 285 } 286 287 static void qed_aio_next_io(void *opaque, int ret); 288 289 static void qed_plug_allocating_write_reqs(BDRVQEDState *s) 290 { 291 assert(!s->allocating_write_reqs_plugged); 292 293 s->allocating_write_reqs_plugged = true; 294 } 295 296 static void qed_unplug_allocating_write_reqs(BDRVQEDState *s) 297 { 298 QEDAIOCB *acb; 299 300 assert(s->allocating_write_reqs_plugged); 301 302 s->allocating_write_reqs_plugged = false; 303 304 acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs); 305 if (acb) { 306 qed_aio_next_io(acb, 0); 307 } 308 } 309 310 static void qed_finish_clear_need_check(void *opaque, int ret) 311 { 312 /* Do nothing */ 313 } 314 315 static void qed_flush_after_clear_need_check(void *opaque, int ret) 316 { 317 BDRVQEDState *s = opaque; 318 319 bdrv_aio_flush(s->bs, qed_finish_clear_need_check, s); 320 321 /* No need to wait until flush completes */ 322 qed_unplug_allocating_write_reqs(s); 323 } 324 325 static void qed_clear_need_check(void *opaque, int ret) 326 { 327 BDRVQEDState *s = opaque; 328 329 if (ret) { 330 qed_unplug_allocating_write_reqs(s); 331 return; 332 } 333 334 s->header.features &= ~QED_F_NEED_CHECK; 335 qed_write_header(s, qed_flush_after_clear_need_check, s); 336 } 337 338 static void qed_need_check_timer_cb(void *opaque) 339 { 340 BDRVQEDState *s = opaque; 341 342 /* The timer should only fire when allocating writes have drained */ 343 assert(!QSIMPLEQ_FIRST(&s->allocating_write_reqs)); 344 345 trace_qed_need_check_timer_cb(s); 346 347 qed_plug_allocating_write_reqs(s); 348 349 /* Ensure writes are on disk before clearing flag */ 350 bdrv_aio_flush(s->bs, qed_clear_need_check, s); 351 } 352 353 static void qed_start_need_check_timer(BDRVQEDState *s) 354 { 355 trace_qed_start_need_check_timer(s); 356 357 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for 358 * migration. 359 */ 360 timer_mod(s->need_check_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 361 get_ticks_per_sec() * QED_NEED_CHECK_TIMEOUT); 362 } 363 364 /* It's okay to call this multiple times or when no timer is started */ 365 static void qed_cancel_need_check_timer(BDRVQEDState *s) 366 { 367 trace_qed_cancel_need_check_timer(s); 368 timer_del(s->need_check_timer); 369 } 370 371 static void bdrv_qed_rebind(BlockDriverState *bs) 372 { 373 BDRVQEDState *s = bs->opaque; 374 s->bs = bs; 375 } 376 377 static void bdrv_qed_detach_aio_context(BlockDriverState *bs) 378 { 379 BDRVQEDState *s = bs->opaque; 380 381 qed_cancel_need_check_timer(s); 382 timer_free(s->need_check_timer); 383 } 384 385 static void bdrv_qed_attach_aio_context(BlockDriverState *bs, 386 AioContext *new_context) 387 { 388 BDRVQEDState *s = bs->opaque; 389 390 s->need_check_timer = aio_timer_new(new_context, 391 QEMU_CLOCK_VIRTUAL, SCALE_NS, 392 qed_need_check_timer_cb, s); 393 if (s->header.features & QED_F_NEED_CHECK) { 394 qed_start_need_check_timer(s); 395 } 396 } 397 398 static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags, 399 Error **errp) 400 { 401 BDRVQEDState *s = bs->opaque; 402 QEDHeader le_header; 403 int64_t file_size; 404 int ret; 405 406 s->bs = bs; 407 QSIMPLEQ_INIT(&s->allocating_write_reqs); 408 409 ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header)); 410 if (ret < 0) { 411 return ret; 412 } 413 qed_header_le_to_cpu(&le_header, &s->header); 414 415 if (s->header.magic != QED_MAGIC) { 416 error_setg(errp, "Image not in QED format"); 417 return -EINVAL; 418 } 419 if (s->header.features & ~QED_FEATURE_MASK) { 420 /* image uses unsupported feature bits */ 421 char buf[64]; 422 snprintf(buf, sizeof(buf), "%" PRIx64, 423 s->header.features & ~QED_FEATURE_MASK); 424 error_set(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, 425 bs->device_name, "QED", buf); 426 return -ENOTSUP; 427 } 428 if (!qed_is_cluster_size_valid(s->header.cluster_size)) { 429 return -EINVAL; 430 } 431 432 /* Round down file size to the last cluster */ 433 file_size = bdrv_getlength(bs->file); 434 if (file_size < 0) { 435 return file_size; 436 } 437 s->file_size = qed_start_of_cluster(s, file_size); 438 439 if (!qed_is_table_size_valid(s->header.table_size)) { 440 return -EINVAL; 441 } 442 if (!qed_is_image_size_valid(s->header.image_size, 443 s->header.cluster_size, 444 s->header.table_size)) { 445 return -EINVAL; 446 } 447 if (!qed_check_table_offset(s, s->header.l1_table_offset)) { 448 return -EINVAL; 449 } 450 451 s->table_nelems = (s->header.cluster_size * s->header.table_size) / 452 sizeof(uint64_t); 453 s->l2_shift = ffs(s->header.cluster_size) - 1; 454 s->l2_mask = s->table_nelems - 1; 455 s->l1_shift = s->l2_shift + ffs(s->table_nelems) - 1; 456 457 if ((s->header.features & QED_F_BACKING_FILE)) { 458 if ((uint64_t)s->header.backing_filename_offset + 459 s->header.backing_filename_size > 460 s->header.cluster_size * s->header.header_size) { 461 return -EINVAL; 462 } 463 464 ret = qed_read_string(bs->file, s->header.backing_filename_offset, 465 s->header.backing_filename_size, bs->backing_file, 466 sizeof(bs->backing_file)); 467 if (ret < 0) { 468 return ret; 469 } 470 471 if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) { 472 pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw"); 473 } 474 } 475 476 /* Reset unknown autoclear feature bits. This is a backwards 477 * compatibility mechanism that allows images to be opened by older 478 * programs, which "knock out" unknown feature bits. When an image is 479 * opened by a newer program again it can detect that the autoclear 480 * feature is no longer valid. 481 */ 482 if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 && 483 !bdrv_is_read_only(bs->file) && !(flags & BDRV_O_INCOMING)) { 484 s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK; 485 486 ret = qed_write_header_sync(s); 487 if (ret) { 488 return ret; 489 } 490 491 /* From here on only known autoclear feature bits are valid */ 492 bdrv_flush(bs->file); 493 } 494 495 s->l1_table = qed_alloc_table(s); 496 qed_init_l2_cache(&s->l2_cache); 497 498 ret = qed_read_l1_table_sync(s); 499 if (ret) { 500 goto out; 501 } 502 503 /* If image was not closed cleanly, check consistency */ 504 if (!(flags & BDRV_O_CHECK) && (s->header.features & QED_F_NEED_CHECK)) { 505 /* Read-only images cannot be fixed. There is no risk of corruption 506 * since write operations are not possible. Therefore, allow 507 * potentially inconsistent images to be opened read-only. This can 508 * aid data recovery from an otherwise inconsistent image. 509 */ 510 if (!bdrv_is_read_only(bs->file) && 511 !(flags & BDRV_O_INCOMING)) { 512 BdrvCheckResult result = {0}; 513 514 ret = qed_check(s, &result, true); 515 if (ret) { 516 goto out; 517 } 518 } 519 } 520 521 bdrv_qed_attach_aio_context(bs, bdrv_get_aio_context(bs)); 522 523 out: 524 if (ret) { 525 qed_free_l2_cache(&s->l2_cache); 526 qemu_vfree(s->l1_table); 527 } 528 return ret; 529 } 530 531 static int bdrv_qed_refresh_limits(BlockDriverState *bs) 532 { 533 BDRVQEDState *s = bs->opaque; 534 535 bs->bl.write_zeroes_alignment = s->header.cluster_size >> BDRV_SECTOR_BITS; 536 537 return 0; 538 } 539 540 /* We have nothing to do for QED reopen, stubs just return 541 * success */ 542 static int bdrv_qed_reopen_prepare(BDRVReopenState *state, 543 BlockReopenQueue *queue, Error **errp) 544 { 545 return 0; 546 } 547 548 static void bdrv_qed_close(BlockDriverState *bs) 549 { 550 BDRVQEDState *s = bs->opaque; 551 552 bdrv_qed_detach_aio_context(bs); 553 554 /* Ensure writes reach stable storage */ 555 bdrv_flush(bs->file); 556 557 /* Clean shutdown, no check required on next open */ 558 if (s->header.features & QED_F_NEED_CHECK) { 559 s->header.features &= ~QED_F_NEED_CHECK; 560 qed_write_header_sync(s); 561 } 562 563 qed_free_l2_cache(&s->l2_cache); 564 qemu_vfree(s->l1_table); 565 } 566 567 static int qed_create(const char *filename, uint32_t cluster_size, 568 uint64_t image_size, uint32_t table_size, 569 const char *backing_file, const char *backing_fmt, 570 Error **errp) 571 { 572 QEDHeader header = { 573 .magic = QED_MAGIC, 574 .cluster_size = cluster_size, 575 .table_size = table_size, 576 .header_size = 1, 577 .features = 0, 578 .compat_features = 0, 579 .l1_table_offset = cluster_size, 580 .image_size = image_size, 581 }; 582 QEDHeader le_header; 583 uint8_t *l1_table = NULL; 584 size_t l1_size = header.cluster_size * header.table_size; 585 Error *local_err = NULL; 586 int ret = 0; 587 BlockDriverState *bs; 588 589 ret = bdrv_create_file(filename, NULL, &local_err); 590 if (ret < 0) { 591 error_propagate(errp, local_err); 592 return ret; 593 } 594 595 bs = NULL; 596 ret = bdrv_open(&bs, filename, NULL, NULL, 597 BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_PROTOCOL, NULL, 598 &local_err); 599 if (ret < 0) { 600 error_propagate(errp, local_err); 601 return ret; 602 } 603 604 /* File must start empty and grow, check truncate is supported */ 605 ret = bdrv_truncate(bs, 0); 606 if (ret < 0) { 607 goto out; 608 } 609 610 if (backing_file) { 611 header.features |= QED_F_BACKING_FILE; 612 header.backing_filename_offset = sizeof(le_header); 613 header.backing_filename_size = strlen(backing_file); 614 615 if (qed_fmt_is_raw(backing_fmt)) { 616 header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 617 } 618 } 619 620 qed_header_cpu_to_le(&header, &le_header); 621 ret = bdrv_pwrite(bs, 0, &le_header, sizeof(le_header)); 622 if (ret < 0) { 623 goto out; 624 } 625 ret = bdrv_pwrite(bs, sizeof(le_header), backing_file, 626 header.backing_filename_size); 627 if (ret < 0) { 628 goto out; 629 } 630 631 l1_table = g_malloc0(l1_size); 632 ret = bdrv_pwrite(bs, header.l1_table_offset, l1_table, l1_size); 633 if (ret < 0) { 634 goto out; 635 } 636 637 ret = 0; /* success */ 638 out: 639 g_free(l1_table); 640 bdrv_unref(bs); 641 return ret; 642 } 643 644 static int bdrv_qed_create(const char *filename, QEMUOptionParameter *options, 645 Error **errp) 646 { 647 uint64_t image_size = 0; 648 uint32_t cluster_size = QED_DEFAULT_CLUSTER_SIZE; 649 uint32_t table_size = QED_DEFAULT_TABLE_SIZE; 650 const char *backing_file = NULL; 651 const char *backing_fmt = NULL; 652 653 while (options && options->name) { 654 if (!strcmp(options->name, BLOCK_OPT_SIZE)) { 655 image_size = options->value.n; 656 } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) { 657 backing_file = options->value.s; 658 } else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) { 659 backing_fmt = options->value.s; 660 } else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) { 661 if (options->value.n) { 662 cluster_size = options->value.n; 663 } 664 } else if (!strcmp(options->name, BLOCK_OPT_TABLE_SIZE)) { 665 if (options->value.n) { 666 table_size = options->value.n; 667 } 668 } 669 options++; 670 } 671 672 if (!qed_is_cluster_size_valid(cluster_size)) { 673 error_setg(errp, "QED cluster size must be within range [%u, %u] " 674 "and power of 2", 675 QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE); 676 return -EINVAL; 677 } 678 if (!qed_is_table_size_valid(table_size)) { 679 error_setg(errp, "QED table size must be within range [%u, %u] " 680 "and power of 2", 681 QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE); 682 return -EINVAL; 683 } 684 if (!qed_is_image_size_valid(image_size, cluster_size, table_size)) { 685 error_setg(errp, "QED image size must be a non-zero multiple of " 686 "cluster size and less than %" PRIu64 " bytes", 687 qed_max_image_size(cluster_size, table_size)); 688 return -EINVAL; 689 } 690 691 return qed_create(filename, cluster_size, image_size, table_size, 692 backing_file, backing_fmt, errp); 693 } 694 695 typedef struct { 696 BlockDriverState *bs; 697 Coroutine *co; 698 uint64_t pos; 699 int64_t status; 700 int *pnum; 701 } QEDIsAllocatedCB; 702 703 static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t len) 704 { 705 QEDIsAllocatedCB *cb = opaque; 706 BDRVQEDState *s = cb->bs->opaque; 707 *cb->pnum = len / BDRV_SECTOR_SIZE; 708 switch (ret) { 709 case QED_CLUSTER_FOUND: 710 offset |= qed_offset_into_cluster(s, cb->pos); 711 cb->status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset; 712 break; 713 case QED_CLUSTER_ZERO: 714 cb->status = BDRV_BLOCK_ZERO; 715 break; 716 case QED_CLUSTER_L2: 717 case QED_CLUSTER_L1: 718 cb->status = 0; 719 break; 720 default: 721 assert(ret < 0); 722 cb->status = ret; 723 break; 724 } 725 726 if (cb->co) { 727 qemu_coroutine_enter(cb->co, NULL); 728 } 729 } 730 731 static int64_t coroutine_fn bdrv_qed_co_get_block_status(BlockDriverState *bs, 732 int64_t sector_num, 733 int nb_sectors, int *pnum) 734 { 735 BDRVQEDState *s = bs->opaque; 736 size_t len = (size_t)nb_sectors * BDRV_SECTOR_SIZE; 737 QEDIsAllocatedCB cb = { 738 .bs = bs, 739 .pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE, 740 .status = BDRV_BLOCK_OFFSET_MASK, 741 .pnum = pnum, 742 }; 743 QEDRequest request = { .l2_table = NULL }; 744 745 qed_find_cluster(s, &request, cb.pos, len, qed_is_allocated_cb, &cb); 746 747 /* Now sleep if the callback wasn't invoked immediately */ 748 while (cb.status == BDRV_BLOCK_OFFSET_MASK) { 749 cb.co = qemu_coroutine_self(); 750 qemu_coroutine_yield(); 751 } 752 753 qed_unref_l2_cache_entry(request.l2_table); 754 755 return cb.status; 756 } 757 758 static BDRVQEDState *acb_to_s(QEDAIOCB *acb) 759 { 760 return acb->common.bs->opaque; 761 } 762 763 /** 764 * Read from the backing file or zero-fill if no backing file 765 * 766 * @s: QED state 767 * @pos: Byte position in device 768 * @qiov: Destination I/O vector 769 * @cb: Completion function 770 * @opaque: User data for completion function 771 * 772 * This function reads qiov->size bytes starting at pos from the backing file. 773 * If there is no backing file then zeroes are read. 774 */ 775 static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos, 776 QEMUIOVector *qiov, 777 BlockDriverCompletionFunc *cb, void *opaque) 778 { 779 uint64_t backing_length = 0; 780 size_t size; 781 782 /* If there is a backing file, get its length. Treat the absence of a 783 * backing file like a zero length backing file. 784 */ 785 if (s->bs->backing_hd) { 786 int64_t l = bdrv_getlength(s->bs->backing_hd); 787 if (l < 0) { 788 cb(opaque, l); 789 return; 790 } 791 backing_length = l; 792 } 793 794 /* Zero all sectors if reading beyond the end of the backing file */ 795 if (pos >= backing_length || 796 pos + qiov->size > backing_length) { 797 qemu_iovec_memset(qiov, 0, 0, qiov->size); 798 } 799 800 /* Complete now if there are no backing file sectors to read */ 801 if (pos >= backing_length) { 802 cb(opaque, 0); 803 return; 804 } 805 806 /* If the read straddles the end of the backing file, shorten it */ 807 size = MIN((uint64_t)backing_length - pos, qiov->size); 808 809 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); 810 bdrv_aio_readv(s->bs->backing_hd, pos / BDRV_SECTOR_SIZE, 811 qiov, size / BDRV_SECTOR_SIZE, cb, opaque); 812 } 813 814 typedef struct { 815 GenericCB gencb; 816 BDRVQEDState *s; 817 QEMUIOVector qiov; 818 struct iovec iov; 819 uint64_t offset; 820 } CopyFromBackingFileCB; 821 822 static void qed_copy_from_backing_file_cb(void *opaque, int ret) 823 { 824 CopyFromBackingFileCB *copy_cb = opaque; 825 qemu_vfree(copy_cb->iov.iov_base); 826 gencb_complete(©_cb->gencb, ret); 827 } 828 829 static void qed_copy_from_backing_file_write(void *opaque, int ret) 830 { 831 CopyFromBackingFileCB *copy_cb = opaque; 832 BDRVQEDState *s = copy_cb->s; 833 834 if (ret) { 835 qed_copy_from_backing_file_cb(copy_cb, ret); 836 return; 837 } 838 839 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); 840 bdrv_aio_writev(s->bs->file, copy_cb->offset / BDRV_SECTOR_SIZE, 841 ©_cb->qiov, copy_cb->qiov.size / BDRV_SECTOR_SIZE, 842 qed_copy_from_backing_file_cb, copy_cb); 843 } 844 845 /** 846 * Copy data from backing file into the image 847 * 848 * @s: QED state 849 * @pos: Byte position in device 850 * @len: Number of bytes 851 * @offset: Byte offset in image file 852 * @cb: Completion function 853 * @opaque: User data for completion function 854 */ 855 static void qed_copy_from_backing_file(BDRVQEDState *s, uint64_t pos, 856 uint64_t len, uint64_t offset, 857 BlockDriverCompletionFunc *cb, 858 void *opaque) 859 { 860 CopyFromBackingFileCB *copy_cb; 861 862 /* Skip copy entirely if there is no work to do */ 863 if (len == 0) { 864 cb(opaque, 0); 865 return; 866 } 867 868 copy_cb = gencb_alloc(sizeof(*copy_cb), cb, opaque); 869 copy_cb->s = s; 870 copy_cb->offset = offset; 871 copy_cb->iov.iov_base = qemu_blockalign(s->bs, len); 872 copy_cb->iov.iov_len = len; 873 qemu_iovec_init_external(©_cb->qiov, ©_cb->iov, 1); 874 875 qed_read_backing_file(s, pos, ©_cb->qiov, 876 qed_copy_from_backing_file_write, copy_cb); 877 } 878 879 /** 880 * Link one or more contiguous clusters into a table 881 * 882 * @s: QED state 883 * @table: L2 table 884 * @index: First cluster index 885 * @n: Number of contiguous clusters 886 * @cluster: First cluster offset 887 * 888 * The cluster offset may be an allocated byte offset in the image file, the 889 * zero cluster marker, or the unallocated cluster marker. 890 */ 891 static void qed_update_l2_table(BDRVQEDState *s, QEDTable *table, int index, 892 unsigned int n, uint64_t cluster) 893 { 894 int i; 895 for (i = index; i < index + n; i++) { 896 table->offsets[i] = cluster; 897 if (!qed_offset_is_unalloc_cluster(cluster) && 898 !qed_offset_is_zero_cluster(cluster)) { 899 cluster += s->header.cluster_size; 900 } 901 } 902 } 903 904 static void qed_aio_complete_bh(void *opaque) 905 { 906 QEDAIOCB *acb = opaque; 907 BlockDriverCompletionFunc *cb = acb->common.cb; 908 void *user_opaque = acb->common.opaque; 909 int ret = acb->bh_ret; 910 bool *finished = acb->finished; 911 912 qemu_bh_delete(acb->bh); 913 qemu_aio_release(acb); 914 915 /* Invoke callback */ 916 cb(user_opaque, ret); 917 918 /* Signal cancel completion */ 919 if (finished) { 920 *finished = true; 921 } 922 } 923 924 static void qed_aio_complete(QEDAIOCB *acb, int ret) 925 { 926 BDRVQEDState *s = acb_to_s(acb); 927 928 trace_qed_aio_complete(s, acb, ret); 929 930 /* Free resources */ 931 qemu_iovec_destroy(&acb->cur_qiov); 932 qed_unref_l2_cache_entry(acb->request.l2_table); 933 934 /* Free the buffer we may have allocated for zero writes */ 935 if (acb->flags & QED_AIOCB_ZERO) { 936 qemu_vfree(acb->qiov->iov[0].iov_base); 937 acb->qiov->iov[0].iov_base = NULL; 938 } 939 940 /* Arrange for a bh to invoke the completion function */ 941 acb->bh_ret = ret; 942 acb->bh = aio_bh_new(bdrv_get_aio_context(acb->common.bs), 943 qed_aio_complete_bh, acb); 944 qemu_bh_schedule(acb->bh); 945 946 /* Start next allocating write request waiting behind this one. Note that 947 * requests enqueue themselves when they first hit an unallocated cluster 948 * but they wait until the entire request is finished before waking up the 949 * next request in the queue. This ensures that we don't cycle through 950 * requests multiple times but rather finish one at a time completely. 951 */ 952 if (acb == QSIMPLEQ_FIRST(&s->allocating_write_reqs)) { 953 QSIMPLEQ_REMOVE_HEAD(&s->allocating_write_reqs, next); 954 acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs); 955 if (acb) { 956 qed_aio_next_io(acb, 0); 957 } else if (s->header.features & QED_F_NEED_CHECK) { 958 qed_start_need_check_timer(s); 959 } 960 } 961 } 962 963 /** 964 * Commit the current L2 table to the cache 965 */ 966 static void qed_commit_l2_update(void *opaque, int ret) 967 { 968 QEDAIOCB *acb = opaque; 969 BDRVQEDState *s = acb_to_s(acb); 970 CachedL2Table *l2_table = acb->request.l2_table; 971 uint64_t l2_offset = l2_table->offset; 972 973 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 974 975 /* This is guaranteed to succeed because we just committed the entry to the 976 * cache. 977 */ 978 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 979 assert(acb->request.l2_table != NULL); 980 981 qed_aio_next_io(opaque, ret); 982 } 983 984 /** 985 * Update L1 table with new L2 table offset and write it out 986 */ 987 static void qed_aio_write_l1_update(void *opaque, int ret) 988 { 989 QEDAIOCB *acb = opaque; 990 BDRVQEDState *s = acb_to_s(acb); 991 int index; 992 993 if (ret) { 994 qed_aio_complete(acb, ret); 995 return; 996 } 997 998 index = qed_l1_index(s, acb->cur_pos); 999 s->l1_table->offsets[index] = acb->request.l2_table->offset; 1000 1001 qed_write_l1_table(s, index, 1, qed_commit_l2_update, acb); 1002 } 1003 1004 /** 1005 * Update L2 table with new cluster offsets and write them out 1006 */ 1007 static void qed_aio_write_l2_update(QEDAIOCB *acb, int ret, uint64_t offset) 1008 { 1009 BDRVQEDState *s = acb_to_s(acb); 1010 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1; 1011 int index; 1012 1013 if (ret) { 1014 goto err; 1015 } 1016 1017 if (need_alloc) { 1018 qed_unref_l2_cache_entry(acb->request.l2_table); 1019 acb->request.l2_table = qed_new_l2_table(s); 1020 } 1021 1022 index = qed_l2_index(s, acb->cur_pos); 1023 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, 1024 offset); 1025 1026 if (need_alloc) { 1027 /* Write out the whole new L2 table */ 1028 qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true, 1029 qed_aio_write_l1_update, acb); 1030 } else { 1031 /* Write out only the updated part of the L2 table */ 1032 qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, false, 1033 qed_aio_next_io, acb); 1034 } 1035 return; 1036 1037 err: 1038 qed_aio_complete(acb, ret); 1039 } 1040 1041 static void qed_aio_write_l2_update_cb(void *opaque, int ret) 1042 { 1043 QEDAIOCB *acb = opaque; 1044 qed_aio_write_l2_update(acb, ret, acb->cur_cluster); 1045 } 1046 1047 /** 1048 * Flush new data clusters before updating the L2 table 1049 * 1050 * This flush is necessary when a backing file is in use. A crash during an 1051 * allocating write could result in empty clusters in the image. If the write 1052 * only touched a subregion of the cluster, then backing image sectors have 1053 * been lost in the untouched region. The solution is to flush after writing a 1054 * new data cluster and before updating the L2 table. 1055 */ 1056 static void qed_aio_write_flush_before_l2_update(void *opaque, int ret) 1057 { 1058 QEDAIOCB *acb = opaque; 1059 BDRVQEDState *s = acb_to_s(acb); 1060 1061 if (!bdrv_aio_flush(s->bs->file, qed_aio_write_l2_update_cb, opaque)) { 1062 qed_aio_complete(acb, -EIO); 1063 } 1064 } 1065 1066 /** 1067 * Write data to the image file 1068 */ 1069 static void qed_aio_write_main(void *opaque, int ret) 1070 { 1071 QEDAIOCB *acb = opaque; 1072 BDRVQEDState *s = acb_to_s(acb); 1073 uint64_t offset = acb->cur_cluster + 1074 qed_offset_into_cluster(s, acb->cur_pos); 1075 BlockDriverCompletionFunc *next_fn; 1076 1077 trace_qed_aio_write_main(s, acb, ret, offset, acb->cur_qiov.size); 1078 1079 if (ret) { 1080 qed_aio_complete(acb, ret); 1081 return; 1082 } 1083 1084 if (acb->find_cluster_ret == QED_CLUSTER_FOUND) { 1085 next_fn = qed_aio_next_io; 1086 } else { 1087 if (s->bs->backing_hd) { 1088 next_fn = qed_aio_write_flush_before_l2_update; 1089 } else { 1090 next_fn = qed_aio_write_l2_update_cb; 1091 } 1092 } 1093 1094 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); 1095 bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE, 1096 &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE, 1097 next_fn, acb); 1098 } 1099 1100 /** 1101 * Populate back untouched region of new data cluster 1102 */ 1103 static void qed_aio_write_postfill(void *opaque, int ret) 1104 { 1105 QEDAIOCB *acb = opaque; 1106 BDRVQEDState *s = acb_to_s(acb); 1107 uint64_t start = acb->cur_pos + acb->cur_qiov.size; 1108 uint64_t len = 1109 qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start; 1110 uint64_t offset = acb->cur_cluster + 1111 qed_offset_into_cluster(s, acb->cur_pos) + 1112 acb->cur_qiov.size; 1113 1114 if (ret) { 1115 qed_aio_complete(acb, ret); 1116 return; 1117 } 1118 1119 trace_qed_aio_write_postfill(s, acb, start, len, offset); 1120 qed_copy_from_backing_file(s, start, len, offset, 1121 qed_aio_write_main, acb); 1122 } 1123 1124 /** 1125 * Populate front untouched region of new data cluster 1126 */ 1127 static void qed_aio_write_prefill(void *opaque, int ret) 1128 { 1129 QEDAIOCB *acb = opaque; 1130 BDRVQEDState *s = acb_to_s(acb); 1131 uint64_t start = qed_start_of_cluster(s, acb->cur_pos); 1132 uint64_t len = qed_offset_into_cluster(s, acb->cur_pos); 1133 1134 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); 1135 qed_copy_from_backing_file(s, start, len, acb->cur_cluster, 1136 qed_aio_write_postfill, acb); 1137 } 1138 1139 /** 1140 * Check if the QED_F_NEED_CHECK bit should be set during allocating write 1141 */ 1142 static bool qed_should_set_need_check(BDRVQEDState *s) 1143 { 1144 /* The flush before L2 update path ensures consistency */ 1145 if (s->bs->backing_hd) { 1146 return false; 1147 } 1148 1149 return !(s->header.features & QED_F_NEED_CHECK); 1150 } 1151 1152 static void qed_aio_write_zero_cluster(void *opaque, int ret) 1153 { 1154 QEDAIOCB *acb = opaque; 1155 1156 if (ret) { 1157 qed_aio_complete(acb, ret); 1158 return; 1159 } 1160 1161 qed_aio_write_l2_update(acb, 0, 1); 1162 } 1163 1164 /** 1165 * Write new data cluster 1166 * 1167 * @acb: Write request 1168 * @len: Length in bytes 1169 * 1170 * This path is taken when writing to previously unallocated clusters. 1171 */ 1172 static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 1173 { 1174 BDRVQEDState *s = acb_to_s(acb); 1175 BlockDriverCompletionFunc *cb; 1176 1177 /* Cancel timer when the first allocating request comes in */ 1178 if (QSIMPLEQ_EMPTY(&s->allocating_write_reqs)) { 1179 qed_cancel_need_check_timer(s); 1180 } 1181 1182 /* Freeze this request if another allocating write is in progress */ 1183 if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs)) { 1184 QSIMPLEQ_INSERT_TAIL(&s->allocating_write_reqs, acb, next); 1185 } 1186 if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs) || 1187 s->allocating_write_reqs_plugged) { 1188 return; /* wait for existing request to finish */ 1189 } 1190 1191 acb->cur_nclusters = qed_bytes_to_clusters(s, 1192 qed_offset_into_cluster(s, acb->cur_pos) + len); 1193 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1194 1195 if (acb->flags & QED_AIOCB_ZERO) { 1196 /* Skip ahead if the clusters are already zero */ 1197 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) { 1198 qed_aio_next_io(acb, 0); 1199 return; 1200 } 1201 1202 cb = qed_aio_write_zero_cluster; 1203 } else { 1204 cb = qed_aio_write_prefill; 1205 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); 1206 } 1207 1208 if (qed_should_set_need_check(s)) { 1209 s->header.features |= QED_F_NEED_CHECK; 1210 qed_write_header(s, cb, acb); 1211 } else { 1212 cb(acb, 0); 1213 } 1214 } 1215 1216 /** 1217 * Write data cluster in place 1218 * 1219 * @acb: Write request 1220 * @offset: Cluster offset in bytes 1221 * @len: Length in bytes 1222 * 1223 * This path is taken when writing to already allocated clusters. 1224 */ 1225 static void qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, size_t len) 1226 { 1227 /* Allocate buffer for zero writes */ 1228 if (acb->flags & QED_AIOCB_ZERO) { 1229 struct iovec *iov = acb->qiov->iov; 1230 1231 if (!iov->iov_base) { 1232 iov->iov_base = qemu_blockalign(acb->common.bs, iov->iov_len); 1233 memset(iov->iov_base, 0, iov->iov_len); 1234 } 1235 } 1236 1237 /* Calculate the I/O vector */ 1238 acb->cur_cluster = offset; 1239 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1240 1241 /* Do the actual write */ 1242 qed_aio_write_main(acb, 0); 1243 } 1244 1245 /** 1246 * Write data cluster 1247 * 1248 * @opaque: Write request 1249 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1, 1250 * or -errno 1251 * @offset: Cluster offset in bytes 1252 * @len: Length in bytes 1253 * 1254 * Callback from qed_find_cluster(). 1255 */ 1256 static void qed_aio_write_data(void *opaque, int ret, 1257 uint64_t offset, size_t len) 1258 { 1259 QEDAIOCB *acb = opaque; 1260 1261 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); 1262 1263 acb->find_cluster_ret = ret; 1264 1265 switch (ret) { 1266 case QED_CLUSTER_FOUND: 1267 qed_aio_write_inplace(acb, offset, len); 1268 break; 1269 1270 case QED_CLUSTER_L2: 1271 case QED_CLUSTER_L1: 1272 case QED_CLUSTER_ZERO: 1273 qed_aio_write_alloc(acb, len); 1274 break; 1275 1276 default: 1277 qed_aio_complete(acb, ret); 1278 break; 1279 } 1280 } 1281 1282 /** 1283 * Read data cluster 1284 * 1285 * @opaque: Read request 1286 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1, 1287 * or -errno 1288 * @offset: Cluster offset in bytes 1289 * @len: Length in bytes 1290 * 1291 * Callback from qed_find_cluster(). 1292 */ 1293 static void qed_aio_read_data(void *opaque, int ret, 1294 uint64_t offset, size_t len) 1295 { 1296 QEDAIOCB *acb = opaque; 1297 BDRVQEDState *s = acb_to_s(acb); 1298 BlockDriverState *bs = acb->common.bs; 1299 1300 /* Adjust offset into cluster */ 1301 offset += qed_offset_into_cluster(s, acb->cur_pos); 1302 1303 trace_qed_aio_read_data(s, acb, ret, offset, len); 1304 1305 if (ret < 0) { 1306 goto err; 1307 } 1308 1309 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1310 1311 /* Handle zero cluster and backing file reads */ 1312 if (ret == QED_CLUSTER_ZERO) { 1313 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size); 1314 qed_aio_next_io(acb, 0); 1315 return; 1316 } else if (ret != QED_CLUSTER_FOUND) { 1317 qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov, 1318 qed_aio_next_io, acb); 1319 return; 1320 } 1321 1322 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 1323 bdrv_aio_readv(bs->file, offset / BDRV_SECTOR_SIZE, 1324 &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE, 1325 qed_aio_next_io, acb); 1326 return; 1327 1328 err: 1329 qed_aio_complete(acb, ret); 1330 } 1331 1332 /** 1333 * Begin next I/O or complete the request 1334 */ 1335 static void qed_aio_next_io(void *opaque, int ret) 1336 { 1337 QEDAIOCB *acb = opaque; 1338 BDRVQEDState *s = acb_to_s(acb); 1339 QEDFindClusterFunc *io_fn = (acb->flags & QED_AIOCB_WRITE) ? 1340 qed_aio_write_data : qed_aio_read_data; 1341 1342 trace_qed_aio_next_io(s, acb, ret, acb->cur_pos + acb->cur_qiov.size); 1343 1344 /* Handle I/O error */ 1345 if (ret) { 1346 qed_aio_complete(acb, ret); 1347 return; 1348 } 1349 1350 acb->qiov_offset += acb->cur_qiov.size; 1351 acb->cur_pos += acb->cur_qiov.size; 1352 qemu_iovec_reset(&acb->cur_qiov); 1353 1354 /* Complete request */ 1355 if (acb->cur_pos >= acb->end_pos) { 1356 qed_aio_complete(acb, 0); 1357 return; 1358 } 1359 1360 /* Find next cluster and start I/O */ 1361 qed_find_cluster(s, &acb->request, 1362 acb->cur_pos, acb->end_pos - acb->cur_pos, 1363 io_fn, acb); 1364 } 1365 1366 static BlockDriverAIOCB *qed_aio_setup(BlockDriverState *bs, 1367 int64_t sector_num, 1368 QEMUIOVector *qiov, int nb_sectors, 1369 BlockDriverCompletionFunc *cb, 1370 void *opaque, int flags) 1371 { 1372 QEDAIOCB *acb = qemu_aio_get(&qed_aiocb_info, bs, cb, opaque); 1373 1374 trace_qed_aio_setup(bs->opaque, acb, sector_num, nb_sectors, 1375 opaque, flags); 1376 1377 acb->flags = flags; 1378 acb->finished = NULL; 1379 acb->qiov = qiov; 1380 acb->qiov_offset = 0; 1381 acb->cur_pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE; 1382 acb->end_pos = acb->cur_pos + nb_sectors * BDRV_SECTOR_SIZE; 1383 acb->request.l2_table = NULL; 1384 qemu_iovec_init(&acb->cur_qiov, qiov->niov); 1385 1386 /* Start request */ 1387 qed_aio_next_io(acb, 0); 1388 return &acb->common; 1389 } 1390 1391 static BlockDriverAIOCB *bdrv_qed_aio_readv(BlockDriverState *bs, 1392 int64_t sector_num, 1393 QEMUIOVector *qiov, int nb_sectors, 1394 BlockDriverCompletionFunc *cb, 1395 void *opaque) 1396 { 1397 return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); 1398 } 1399 1400 static BlockDriverAIOCB *bdrv_qed_aio_writev(BlockDriverState *bs, 1401 int64_t sector_num, 1402 QEMUIOVector *qiov, int nb_sectors, 1403 BlockDriverCompletionFunc *cb, 1404 void *opaque) 1405 { 1406 return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, 1407 opaque, QED_AIOCB_WRITE); 1408 } 1409 1410 typedef struct { 1411 Coroutine *co; 1412 int ret; 1413 bool done; 1414 } QEDWriteZeroesCB; 1415 1416 static void coroutine_fn qed_co_write_zeroes_cb(void *opaque, int ret) 1417 { 1418 QEDWriteZeroesCB *cb = opaque; 1419 1420 cb->done = true; 1421 cb->ret = ret; 1422 if (cb->co) { 1423 qemu_coroutine_enter(cb->co, NULL); 1424 } 1425 } 1426 1427 static int coroutine_fn bdrv_qed_co_write_zeroes(BlockDriverState *bs, 1428 int64_t sector_num, 1429 int nb_sectors, 1430 BdrvRequestFlags flags) 1431 { 1432 BlockDriverAIOCB *blockacb; 1433 BDRVQEDState *s = bs->opaque; 1434 QEDWriteZeroesCB cb = { .done = false }; 1435 QEMUIOVector qiov; 1436 struct iovec iov; 1437 1438 /* Refuse if there are untouched backing file sectors */ 1439 if (bs->backing_hd) { 1440 if (qed_offset_into_cluster(s, sector_num * BDRV_SECTOR_SIZE) != 0) { 1441 return -ENOTSUP; 1442 } 1443 if (qed_offset_into_cluster(s, nb_sectors * BDRV_SECTOR_SIZE) != 0) { 1444 return -ENOTSUP; 1445 } 1446 } 1447 1448 /* Zero writes start without an I/O buffer. If a buffer becomes necessary 1449 * then it will be allocated during request processing. 1450 */ 1451 iov.iov_base = NULL, 1452 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE, 1453 1454 qemu_iovec_init_external(&qiov, &iov, 1); 1455 blockacb = qed_aio_setup(bs, sector_num, &qiov, nb_sectors, 1456 qed_co_write_zeroes_cb, &cb, 1457 QED_AIOCB_WRITE | QED_AIOCB_ZERO); 1458 if (!blockacb) { 1459 return -EIO; 1460 } 1461 if (!cb.done) { 1462 cb.co = qemu_coroutine_self(); 1463 qemu_coroutine_yield(); 1464 } 1465 assert(cb.done); 1466 return cb.ret; 1467 } 1468 1469 static int bdrv_qed_truncate(BlockDriverState *bs, int64_t offset) 1470 { 1471 BDRVQEDState *s = bs->opaque; 1472 uint64_t old_image_size; 1473 int ret; 1474 1475 if (!qed_is_image_size_valid(offset, s->header.cluster_size, 1476 s->header.table_size)) { 1477 return -EINVAL; 1478 } 1479 1480 /* Shrinking is currently not supported */ 1481 if ((uint64_t)offset < s->header.image_size) { 1482 return -ENOTSUP; 1483 } 1484 1485 old_image_size = s->header.image_size; 1486 s->header.image_size = offset; 1487 ret = qed_write_header_sync(s); 1488 if (ret < 0) { 1489 s->header.image_size = old_image_size; 1490 } 1491 return ret; 1492 } 1493 1494 static int64_t bdrv_qed_getlength(BlockDriverState *bs) 1495 { 1496 BDRVQEDState *s = bs->opaque; 1497 return s->header.image_size; 1498 } 1499 1500 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1501 { 1502 BDRVQEDState *s = bs->opaque; 1503 1504 memset(bdi, 0, sizeof(*bdi)); 1505 bdi->cluster_size = s->header.cluster_size; 1506 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK; 1507 bdi->unallocated_blocks_are_zero = true; 1508 bdi->can_write_zeroes_with_unmap = true; 1509 return 0; 1510 } 1511 1512 static int bdrv_qed_change_backing_file(BlockDriverState *bs, 1513 const char *backing_file, 1514 const char *backing_fmt) 1515 { 1516 BDRVQEDState *s = bs->opaque; 1517 QEDHeader new_header, le_header; 1518 void *buffer; 1519 size_t buffer_len, backing_file_len; 1520 int ret; 1521 1522 /* Refuse to set backing filename if unknown compat feature bits are 1523 * active. If the image uses an unknown compat feature then we may not 1524 * know the layout of data following the header structure and cannot safely 1525 * add a new string. 1526 */ 1527 if (backing_file && (s->header.compat_features & 1528 ~QED_COMPAT_FEATURE_MASK)) { 1529 return -ENOTSUP; 1530 } 1531 1532 memcpy(&new_header, &s->header, sizeof(new_header)); 1533 1534 new_header.features &= ~(QED_F_BACKING_FILE | 1535 QED_F_BACKING_FORMAT_NO_PROBE); 1536 1537 /* Adjust feature flags */ 1538 if (backing_file) { 1539 new_header.features |= QED_F_BACKING_FILE; 1540 1541 if (qed_fmt_is_raw(backing_fmt)) { 1542 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 1543 } 1544 } 1545 1546 /* Calculate new header size */ 1547 backing_file_len = 0; 1548 1549 if (backing_file) { 1550 backing_file_len = strlen(backing_file); 1551 } 1552 1553 buffer_len = sizeof(new_header); 1554 new_header.backing_filename_offset = buffer_len; 1555 new_header.backing_filename_size = backing_file_len; 1556 buffer_len += backing_file_len; 1557 1558 /* Make sure we can rewrite header without failing */ 1559 if (buffer_len > new_header.header_size * new_header.cluster_size) { 1560 return -ENOSPC; 1561 } 1562 1563 /* Prepare new header */ 1564 buffer = g_malloc(buffer_len); 1565 1566 qed_header_cpu_to_le(&new_header, &le_header); 1567 memcpy(buffer, &le_header, sizeof(le_header)); 1568 buffer_len = sizeof(le_header); 1569 1570 if (backing_file) { 1571 memcpy(buffer + buffer_len, backing_file, backing_file_len); 1572 buffer_len += backing_file_len; 1573 } 1574 1575 /* Write new header */ 1576 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len); 1577 g_free(buffer); 1578 if (ret == 0) { 1579 memcpy(&s->header, &new_header, sizeof(new_header)); 1580 } 1581 return ret; 1582 } 1583 1584 static void bdrv_qed_invalidate_cache(BlockDriverState *bs, Error **errp) 1585 { 1586 BDRVQEDState *s = bs->opaque; 1587 Error *local_err = NULL; 1588 int ret; 1589 1590 bdrv_qed_close(bs); 1591 1592 bdrv_invalidate_cache(bs->file, &local_err); 1593 if (local_err) { 1594 error_propagate(errp, local_err); 1595 return; 1596 } 1597 1598 memset(s, 0, sizeof(BDRVQEDState)); 1599 ret = bdrv_qed_open(bs, NULL, bs->open_flags, &local_err); 1600 if (local_err) { 1601 error_setg(errp, "Could not reopen qed layer: %s", 1602 error_get_pretty(local_err)); 1603 error_free(local_err); 1604 return; 1605 } else if (ret < 0) { 1606 error_setg_errno(errp, -ret, "Could not reopen qed layer"); 1607 return; 1608 } 1609 } 1610 1611 static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result, 1612 BdrvCheckMode fix) 1613 { 1614 BDRVQEDState *s = bs->opaque; 1615 1616 return qed_check(s, result, !!fix); 1617 } 1618 1619 static QEMUOptionParameter qed_create_options[] = { 1620 { 1621 .name = BLOCK_OPT_SIZE, 1622 .type = OPT_SIZE, 1623 .help = "Virtual disk size (in bytes)" 1624 }, { 1625 .name = BLOCK_OPT_BACKING_FILE, 1626 .type = OPT_STRING, 1627 .help = "File name of a base image" 1628 }, { 1629 .name = BLOCK_OPT_BACKING_FMT, 1630 .type = OPT_STRING, 1631 .help = "Image format of the base image" 1632 }, { 1633 .name = BLOCK_OPT_CLUSTER_SIZE, 1634 .type = OPT_SIZE, 1635 .help = "Cluster size (in bytes)", 1636 .value = { .n = QED_DEFAULT_CLUSTER_SIZE }, 1637 }, { 1638 .name = BLOCK_OPT_TABLE_SIZE, 1639 .type = OPT_SIZE, 1640 .help = "L1/L2 table size (in clusters)" 1641 }, 1642 { /* end of list */ } 1643 }; 1644 1645 static BlockDriver bdrv_qed = { 1646 .format_name = "qed", 1647 .instance_size = sizeof(BDRVQEDState), 1648 .create_options = qed_create_options, 1649 1650 .bdrv_probe = bdrv_qed_probe, 1651 .bdrv_rebind = bdrv_qed_rebind, 1652 .bdrv_open = bdrv_qed_open, 1653 .bdrv_close = bdrv_qed_close, 1654 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare, 1655 .bdrv_create = bdrv_qed_create, 1656 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1657 .bdrv_co_get_block_status = bdrv_qed_co_get_block_status, 1658 .bdrv_aio_readv = bdrv_qed_aio_readv, 1659 .bdrv_aio_writev = bdrv_qed_aio_writev, 1660 .bdrv_co_write_zeroes = bdrv_qed_co_write_zeroes, 1661 .bdrv_truncate = bdrv_qed_truncate, 1662 .bdrv_getlength = bdrv_qed_getlength, 1663 .bdrv_get_info = bdrv_qed_get_info, 1664 .bdrv_refresh_limits = bdrv_qed_refresh_limits, 1665 .bdrv_change_backing_file = bdrv_qed_change_backing_file, 1666 .bdrv_invalidate_cache = bdrv_qed_invalidate_cache, 1667 .bdrv_check = bdrv_qed_check, 1668 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context, 1669 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context, 1670 }; 1671 1672 static void bdrv_qed_init(void) 1673 { 1674 bdrv_register(&bdrv_qed); 1675 } 1676 1677 block_init(bdrv_qed_init); 1678