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 QemuOpts *opts, 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, opts, &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, QemuOpts *opts, Error **errp) 645 { 646 uint64_t image_size = 0; 647 uint32_t cluster_size = QED_DEFAULT_CLUSTER_SIZE; 648 uint32_t table_size = QED_DEFAULT_TABLE_SIZE; 649 char *backing_file = NULL; 650 char *backing_fmt = NULL; 651 int ret; 652 653 image_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); 654 backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); 655 backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT); 656 cluster_size = qemu_opt_get_size_del(opts, 657 BLOCK_OPT_CLUSTER_SIZE, 658 QED_DEFAULT_CLUSTER_SIZE); 659 table_size = qemu_opt_get_size_del(opts, BLOCK_OPT_TABLE_SIZE, 660 QED_DEFAULT_TABLE_SIZE); 661 662 if (!qed_is_cluster_size_valid(cluster_size)) { 663 error_setg(errp, "QED cluster size must be within range [%u, %u] " 664 "and power of 2", 665 QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE); 666 ret = -EINVAL; 667 goto finish; 668 } 669 if (!qed_is_table_size_valid(table_size)) { 670 error_setg(errp, "QED table size must be within range [%u, %u] " 671 "and power of 2", 672 QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE); 673 ret = -EINVAL; 674 goto finish; 675 } 676 if (!qed_is_image_size_valid(image_size, cluster_size, table_size)) { 677 error_setg(errp, "QED image size must be a non-zero multiple of " 678 "cluster size and less than %" PRIu64 " bytes", 679 qed_max_image_size(cluster_size, table_size)); 680 ret = -EINVAL; 681 goto finish; 682 } 683 684 ret = qed_create(filename, cluster_size, image_size, table_size, 685 backing_file, backing_fmt, opts, errp); 686 687 finish: 688 g_free(backing_file); 689 g_free(backing_fmt); 690 return ret; 691 } 692 693 typedef struct { 694 BlockDriverState *bs; 695 Coroutine *co; 696 uint64_t pos; 697 int64_t status; 698 int *pnum; 699 } QEDIsAllocatedCB; 700 701 static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t len) 702 { 703 QEDIsAllocatedCB *cb = opaque; 704 BDRVQEDState *s = cb->bs->opaque; 705 *cb->pnum = len / BDRV_SECTOR_SIZE; 706 switch (ret) { 707 case QED_CLUSTER_FOUND: 708 offset |= qed_offset_into_cluster(s, cb->pos); 709 cb->status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset; 710 break; 711 case QED_CLUSTER_ZERO: 712 cb->status = BDRV_BLOCK_ZERO; 713 break; 714 case QED_CLUSTER_L2: 715 case QED_CLUSTER_L1: 716 cb->status = 0; 717 break; 718 default: 719 assert(ret < 0); 720 cb->status = ret; 721 break; 722 } 723 724 if (cb->co) { 725 qemu_coroutine_enter(cb->co, NULL); 726 } 727 } 728 729 static int64_t coroutine_fn bdrv_qed_co_get_block_status(BlockDriverState *bs, 730 int64_t sector_num, 731 int nb_sectors, int *pnum) 732 { 733 BDRVQEDState *s = bs->opaque; 734 size_t len = (size_t)nb_sectors * BDRV_SECTOR_SIZE; 735 QEDIsAllocatedCB cb = { 736 .bs = bs, 737 .pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE, 738 .status = BDRV_BLOCK_OFFSET_MASK, 739 .pnum = pnum, 740 }; 741 QEDRequest request = { .l2_table = NULL }; 742 743 qed_find_cluster(s, &request, cb.pos, len, qed_is_allocated_cb, &cb); 744 745 /* Now sleep if the callback wasn't invoked immediately */ 746 while (cb.status == BDRV_BLOCK_OFFSET_MASK) { 747 cb.co = qemu_coroutine_self(); 748 qemu_coroutine_yield(); 749 } 750 751 qed_unref_l2_cache_entry(request.l2_table); 752 753 return cb.status; 754 } 755 756 static BDRVQEDState *acb_to_s(QEDAIOCB *acb) 757 { 758 return acb->common.bs->opaque; 759 } 760 761 /** 762 * Read from the backing file or zero-fill if no backing file 763 * 764 * @s: QED state 765 * @pos: Byte position in device 766 * @qiov: Destination I/O vector 767 * @cb: Completion function 768 * @opaque: User data for completion function 769 * 770 * This function reads qiov->size bytes starting at pos from the backing file. 771 * If there is no backing file then zeroes are read. 772 */ 773 static void qed_read_backing_file(BDRVQEDState *s, uint64_t pos, 774 QEMUIOVector *qiov, 775 BlockDriverCompletionFunc *cb, void *opaque) 776 { 777 uint64_t backing_length = 0; 778 size_t size; 779 780 /* If there is a backing file, get its length. Treat the absence of a 781 * backing file like a zero length backing file. 782 */ 783 if (s->bs->backing_hd) { 784 int64_t l = bdrv_getlength(s->bs->backing_hd); 785 if (l < 0) { 786 cb(opaque, l); 787 return; 788 } 789 backing_length = l; 790 } 791 792 /* Zero all sectors if reading beyond the end of the backing file */ 793 if (pos >= backing_length || 794 pos + qiov->size > backing_length) { 795 qemu_iovec_memset(qiov, 0, 0, qiov->size); 796 } 797 798 /* Complete now if there are no backing file sectors to read */ 799 if (pos >= backing_length) { 800 cb(opaque, 0); 801 return; 802 } 803 804 /* If the read straddles the end of the backing file, shorten it */ 805 size = MIN((uint64_t)backing_length - pos, qiov->size); 806 807 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); 808 bdrv_aio_readv(s->bs->backing_hd, pos / BDRV_SECTOR_SIZE, 809 qiov, size / BDRV_SECTOR_SIZE, cb, opaque); 810 } 811 812 typedef struct { 813 GenericCB gencb; 814 BDRVQEDState *s; 815 QEMUIOVector qiov; 816 struct iovec iov; 817 uint64_t offset; 818 } CopyFromBackingFileCB; 819 820 static void qed_copy_from_backing_file_cb(void *opaque, int ret) 821 { 822 CopyFromBackingFileCB *copy_cb = opaque; 823 qemu_vfree(copy_cb->iov.iov_base); 824 gencb_complete(©_cb->gencb, ret); 825 } 826 827 static void qed_copy_from_backing_file_write(void *opaque, int ret) 828 { 829 CopyFromBackingFileCB *copy_cb = opaque; 830 BDRVQEDState *s = copy_cb->s; 831 832 if (ret) { 833 qed_copy_from_backing_file_cb(copy_cb, ret); 834 return; 835 } 836 837 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); 838 bdrv_aio_writev(s->bs->file, copy_cb->offset / BDRV_SECTOR_SIZE, 839 ©_cb->qiov, copy_cb->qiov.size / BDRV_SECTOR_SIZE, 840 qed_copy_from_backing_file_cb, copy_cb); 841 } 842 843 /** 844 * Copy data from backing file into the image 845 * 846 * @s: QED state 847 * @pos: Byte position in device 848 * @len: Number of bytes 849 * @offset: Byte offset in image file 850 * @cb: Completion function 851 * @opaque: User data for completion function 852 */ 853 static void qed_copy_from_backing_file(BDRVQEDState *s, uint64_t pos, 854 uint64_t len, uint64_t offset, 855 BlockDriverCompletionFunc *cb, 856 void *opaque) 857 { 858 CopyFromBackingFileCB *copy_cb; 859 860 /* Skip copy entirely if there is no work to do */ 861 if (len == 0) { 862 cb(opaque, 0); 863 return; 864 } 865 866 copy_cb = gencb_alloc(sizeof(*copy_cb), cb, opaque); 867 copy_cb->s = s; 868 copy_cb->offset = offset; 869 copy_cb->iov.iov_base = qemu_blockalign(s->bs, len); 870 copy_cb->iov.iov_len = len; 871 qemu_iovec_init_external(©_cb->qiov, ©_cb->iov, 1); 872 873 qed_read_backing_file(s, pos, ©_cb->qiov, 874 qed_copy_from_backing_file_write, copy_cb); 875 } 876 877 /** 878 * Link one or more contiguous clusters into a table 879 * 880 * @s: QED state 881 * @table: L2 table 882 * @index: First cluster index 883 * @n: Number of contiguous clusters 884 * @cluster: First cluster offset 885 * 886 * The cluster offset may be an allocated byte offset in the image file, the 887 * zero cluster marker, or the unallocated cluster marker. 888 */ 889 static void qed_update_l2_table(BDRVQEDState *s, QEDTable *table, int index, 890 unsigned int n, uint64_t cluster) 891 { 892 int i; 893 for (i = index; i < index + n; i++) { 894 table->offsets[i] = cluster; 895 if (!qed_offset_is_unalloc_cluster(cluster) && 896 !qed_offset_is_zero_cluster(cluster)) { 897 cluster += s->header.cluster_size; 898 } 899 } 900 } 901 902 static void qed_aio_complete_bh(void *opaque) 903 { 904 QEDAIOCB *acb = opaque; 905 BlockDriverCompletionFunc *cb = acb->common.cb; 906 void *user_opaque = acb->common.opaque; 907 int ret = acb->bh_ret; 908 bool *finished = acb->finished; 909 910 qemu_bh_delete(acb->bh); 911 qemu_aio_release(acb); 912 913 /* Invoke callback */ 914 cb(user_opaque, ret); 915 916 /* Signal cancel completion */ 917 if (finished) { 918 *finished = true; 919 } 920 } 921 922 static void qed_aio_complete(QEDAIOCB *acb, int ret) 923 { 924 BDRVQEDState *s = acb_to_s(acb); 925 926 trace_qed_aio_complete(s, acb, ret); 927 928 /* Free resources */ 929 qemu_iovec_destroy(&acb->cur_qiov); 930 qed_unref_l2_cache_entry(acb->request.l2_table); 931 932 /* Free the buffer we may have allocated for zero writes */ 933 if (acb->flags & QED_AIOCB_ZERO) { 934 qemu_vfree(acb->qiov->iov[0].iov_base); 935 acb->qiov->iov[0].iov_base = NULL; 936 } 937 938 /* Arrange for a bh to invoke the completion function */ 939 acb->bh_ret = ret; 940 acb->bh = aio_bh_new(bdrv_get_aio_context(acb->common.bs), 941 qed_aio_complete_bh, acb); 942 qemu_bh_schedule(acb->bh); 943 944 /* Start next allocating write request waiting behind this one. Note that 945 * requests enqueue themselves when they first hit an unallocated cluster 946 * but they wait until the entire request is finished before waking up the 947 * next request in the queue. This ensures that we don't cycle through 948 * requests multiple times but rather finish one at a time completely. 949 */ 950 if (acb == QSIMPLEQ_FIRST(&s->allocating_write_reqs)) { 951 QSIMPLEQ_REMOVE_HEAD(&s->allocating_write_reqs, next); 952 acb = QSIMPLEQ_FIRST(&s->allocating_write_reqs); 953 if (acb) { 954 qed_aio_next_io(acb, 0); 955 } else if (s->header.features & QED_F_NEED_CHECK) { 956 qed_start_need_check_timer(s); 957 } 958 } 959 } 960 961 /** 962 * Commit the current L2 table to the cache 963 */ 964 static void qed_commit_l2_update(void *opaque, int ret) 965 { 966 QEDAIOCB *acb = opaque; 967 BDRVQEDState *s = acb_to_s(acb); 968 CachedL2Table *l2_table = acb->request.l2_table; 969 uint64_t l2_offset = l2_table->offset; 970 971 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 972 973 /* This is guaranteed to succeed because we just committed the entry to the 974 * cache. 975 */ 976 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 977 assert(acb->request.l2_table != NULL); 978 979 qed_aio_next_io(opaque, ret); 980 } 981 982 /** 983 * Update L1 table with new L2 table offset and write it out 984 */ 985 static void qed_aio_write_l1_update(void *opaque, int ret) 986 { 987 QEDAIOCB *acb = opaque; 988 BDRVQEDState *s = acb_to_s(acb); 989 int index; 990 991 if (ret) { 992 qed_aio_complete(acb, ret); 993 return; 994 } 995 996 index = qed_l1_index(s, acb->cur_pos); 997 s->l1_table->offsets[index] = acb->request.l2_table->offset; 998 999 qed_write_l1_table(s, index, 1, qed_commit_l2_update, acb); 1000 } 1001 1002 /** 1003 * Update L2 table with new cluster offsets and write them out 1004 */ 1005 static void qed_aio_write_l2_update(QEDAIOCB *acb, int ret, uint64_t offset) 1006 { 1007 BDRVQEDState *s = acb_to_s(acb); 1008 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1; 1009 int index; 1010 1011 if (ret) { 1012 goto err; 1013 } 1014 1015 if (need_alloc) { 1016 qed_unref_l2_cache_entry(acb->request.l2_table); 1017 acb->request.l2_table = qed_new_l2_table(s); 1018 } 1019 1020 index = qed_l2_index(s, acb->cur_pos); 1021 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, 1022 offset); 1023 1024 if (need_alloc) { 1025 /* Write out the whole new L2 table */ 1026 qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true, 1027 qed_aio_write_l1_update, acb); 1028 } else { 1029 /* Write out only the updated part of the L2 table */ 1030 qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, false, 1031 qed_aio_next_io, acb); 1032 } 1033 return; 1034 1035 err: 1036 qed_aio_complete(acb, ret); 1037 } 1038 1039 static void qed_aio_write_l2_update_cb(void *opaque, int ret) 1040 { 1041 QEDAIOCB *acb = opaque; 1042 qed_aio_write_l2_update(acb, ret, acb->cur_cluster); 1043 } 1044 1045 /** 1046 * Flush new data clusters before updating the L2 table 1047 * 1048 * This flush is necessary when a backing file is in use. A crash during an 1049 * allocating write could result in empty clusters in the image. If the write 1050 * only touched a subregion of the cluster, then backing image sectors have 1051 * been lost in the untouched region. The solution is to flush after writing a 1052 * new data cluster and before updating the L2 table. 1053 */ 1054 static void qed_aio_write_flush_before_l2_update(void *opaque, int ret) 1055 { 1056 QEDAIOCB *acb = opaque; 1057 BDRVQEDState *s = acb_to_s(acb); 1058 1059 if (!bdrv_aio_flush(s->bs->file, qed_aio_write_l2_update_cb, opaque)) { 1060 qed_aio_complete(acb, -EIO); 1061 } 1062 } 1063 1064 /** 1065 * Write data to the image file 1066 */ 1067 static void qed_aio_write_main(void *opaque, int ret) 1068 { 1069 QEDAIOCB *acb = opaque; 1070 BDRVQEDState *s = acb_to_s(acb); 1071 uint64_t offset = acb->cur_cluster + 1072 qed_offset_into_cluster(s, acb->cur_pos); 1073 BlockDriverCompletionFunc *next_fn; 1074 1075 trace_qed_aio_write_main(s, acb, ret, offset, acb->cur_qiov.size); 1076 1077 if (ret) { 1078 qed_aio_complete(acb, ret); 1079 return; 1080 } 1081 1082 if (acb->find_cluster_ret == QED_CLUSTER_FOUND) { 1083 next_fn = qed_aio_next_io; 1084 } else { 1085 if (s->bs->backing_hd) { 1086 next_fn = qed_aio_write_flush_before_l2_update; 1087 } else { 1088 next_fn = qed_aio_write_l2_update_cb; 1089 } 1090 } 1091 1092 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); 1093 bdrv_aio_writev(s->bs->file, offset / BDRV_SECTOR_SIZE, 1094 &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE, 1095 next_fn, acb); 1096 } 1097 1098 /** 1099 * Populate back untouched region of new data cluster 1100 */ 1101 static void qed_aio_write_postfill(void *opaque, int ret) 1102 { 1103 QEDAIOCB *acb = opaque; 1104 BDRVQEDState *s = acb_to_s(acb); 1105 uint64_t start = acb->cur_pos + acb->cur_qiov.size; 1106 uint64_t len = 1107 qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start; 1108 uint64_t offset = acb->cur_cluster + 1109 qed_offset_into_cluster(s, acb->cur_pos) + 1110 acb->cur_qiov.size; 1111 1112 if (ret) { 1113 qed_aio_complete(acb, ret); 1114 return; 1115 } 1116 1117 trace_qed_aio_write_postfill(s, acb, start, len, offset); 1118 qed_copy_from_backing_file(s, start, len, offset, 1119 qed_aio_write_main, acb); 1120 } 1121 1122 /** 1123 * Populate front untouched region of new data cluster 1124 */ 1125 static void qed_aio_write_prefill(void *opaque, int ret) 1126 { 1127 QEDAIOCB *acb = opaque; 1128 BDRVQEDState *s = acb_to_s(acb); 1129 uint64_t start = qed_start_of_cluster(s, acb->cur_pos); 1130 uint64_t len = qed_offset_into_cluster(s, acb->cur_pos); 1131 1132 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); 1133 qed_copy_from_backing_file(s, start, len, acb->cur_cluster, 1134 qed_aio_write_postfill, acb); 1135 } 1136 1137 /** 1138 * Check if the QED_F_NEED_CHECK bit should be set during allocating write 1139 */ 1140 static bool qed_should_set_need_check(BDRVQEDState *s) 1141 { 1142 /* The flush before L2 update path ensures consistency */ 1143 if (s->bs->backing_hd) { 1144 return false; 1145 } 1146 1147 return !(s->header.features & QED_F_NEED_CHECK); 1148 } 1149 1150 static void qed_aio_write_zero_cluster(void *opaque, int ret) 1151 { 1152 QEDAIOCB *acb = opaque; 1153 1154 if (ret) { 1155 qed_aio_complete(acb, ret); 1156 return; 1157 } 1158 1159 qed_aio_write_l2_update(acb, 0, 1); 1160 } 1161 1162 /** 1163 * Write new data cluster 1164 * 1165 * @acb: Write request 1166 * @len: Length in bytes 1167 * 1168 * This path is taken when writing to previously unallocated clusters. 1169 */ 1170 static void qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 1171 { 1172 BDRVQEDState *s = acb_to_s(acb); 1173 BlockDriverCompletionFunc *cb; 1174 1175 /* Cancel timer when the first allocating request comes in */ 1176 if (QSIMPLEQ_EMPTY(&s->allocating_write_reqs)) { 1177 qed_cancel_need_check_timer(s); 1178 } 1179 1180 /* Freeze this request if another allocating write is in progress */ 1181 if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs)) { 1182 QSIMPLEQ_INSERT_TAIL(&s->allocating_write_reqs, acb, next); 1183 } 1184 if (acb != QSIMPLEQ_FIRST(&s->allocating_write_reqs) || 1185 s->allocating_write_reqs_plugged) { 1186 return; /* wait for existing request to finish */ 1187 } 1188 1189 acb->cur_nclusters = qed_bytes_to_clusters(s, 1190 qed_offset_into_cluster(s, acb->cur_pos) + len); 1191 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1192 1193 if (acb->flags & QED_AIOCB_ZERO) { 1194 /* Skip ahead if the clusters are already zero */ 1195 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) { 1196 qed_aio_next_io(acb, 0); 1197 return; 1198 } 1199 1200 cb = qed_aio_write_zero_cluster; 1201 } else { 1202 cb = qed_aio_write_prefill; 1203 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); 1204 } 1205 1206 if (qed_should_set_need_check(s)) { 1207 s->header.features |= QED_F_NEED_CHECK; 1208 qed_write_header(s, cb, acb); 1209 } else { 1210 cb(acb, 0); 1211 } 1212 } 1213 1214 /** 1215 * Write data cluster in place 1216 * 1217 * @acb: Write request 1218 * @offset: Cluster offset in bytes 1219 * @len: Length in bytes 1220 * 1221 * This path is taken when writing to already allocated clusters. 1222 */ 1223 static void qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, size_t len) 1224 { 1225 /* Allocate buffer for zero writes */ 1226 if (acb->flags & QED_AIOCB_ZERO) { 1227 struct iovec *iov = acb->qiov->iov; 1228 1229 if (!iov->iov_base) { 1230 iov->iov_base = qemu_blockalign(acb->common.bs, iov->iov_len); 1231 memset(iov->iov_base, 0, iov->iov_len); 1232 } 1233 } 1234 1235 /* Calculate the I/O vector */ 1236 acb->cur_cluster = offset; 1237 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1238 1239 /* Do the actual write */ 1240 qed_aio_write_main(acb, 0); 1241 } 1242 1243 /** 1244 * Write data cluster 1245 * 1246 * @opaque: Write request 1247 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1, 1248 * or -errno 1249 * @offset: Cluster offset in bytes 1250 * @len: Length in bytes 1251 * 1252 * Callback from qed_find_cluster(). 1253 */ 1254 static void qed_aio_write_data(void *opaque, int ret, 1255 uint64_t offset, size_t len) 1256 { 1257 QEDAIOCB *acb = opaque; 1258 1259 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); 1260 1261 acb->find_cluster_ret = ret; 1262 1263 switch (ret) { 1264 case QED_CLUSTER_FOUND: 1265 qed_aio_write_inplace(acb, offset, len); 1266 break; 1267 1268 case QED_CLUSTER_L2: 1269 case QED_CLUSTER_L1: 1270 case QED_CLUSTER_ZERO: 1271 qed_aio_write_alloc(acb, len); 1272 break; 1273 1274 default: 1275 qed_aio_complete(acb, ret); 1276 break; 1277 } 1278 } 1279 1280 /** 1281 * Read data cluster 1282 * 1283 * @opaque: Read request 1284 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2, QED_CLUSTER_L1, 1285 * or -errno 1286 * @offset: Cluster offset in bytes 1287 * @len: Length in bytes 1288 * 1289 * Callback from qed_find_cluster(). 1290 */ 1291 static void qed_aio_read_data(void *opaque, int ret, 1292 uint64_t offset, size_t len) 1293 { 1294 QEDAIOCB *acb = opaque; 1295 BDRVQEDState *s = acb_to_s(acb); 1296 BlockDriverState *bs = acb->common.bs; 1297 1298 /* Adjust offset into cluster */ 1299 offset += qed_offset_into_cluster(s, acb->cur_pos); 1300 1301 trace_qed_aio_read_data(s, acb, ret, offset, len); 1302 1303 if (ret < 0) { 1304 goto err; 1305 } 1306 1307 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1308 1309 /* Handle zero cluster and backing file reads */ 1310 if (ret == QED_CLUSTER_ZERO) { 1311 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size); 1312 qed_aio_next_io(acb, 0); 1313 return; 1314 } else if (ret != QED_CLUSTER_FOUND) { 1315 qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov, 1316 qed_aio_next_io, acb); 1317 return; 1318 } 1319 1320 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 1321 bdrv_aio_readv(bs->file, offset / BDRV_SECTOR_SIZE, 1322 &acb->cur_qiov, acb->cur_qiov.size / BDRV_SECTOR_SIZE, 1323 qed_aio_next_io, acb); 1324 return; 1325 1326 err: 1327 qed_aio_complete(acb, ret); 1328 } 1329 1330 /** 1331 * Begin next I/O or complete the request 1332 */ 1333 static void qed_aio_next_io(void *opaque, int ret) 1334 { 1335 QEDAIOCB *acb = opaque; 1336 BDRVQEDState *s = acb_to_s(acb); 1337 QEDFindClusterFunc *io_fn = (acb->flags & QED_AIOCB_WRITE) ? 1338 qed_aio_write_data : qed_aio_read_data; 1339 1340 trace_qed_aio_next_io(s, acb, ret, acb->cur_pos + acb->cur_qiov.size); 1341 1342 /* Handle I/O error */ 1343 if (ret) { 1344 qed_aio_complete(acb, ret); 1345 return; 1346 } 1347 1348 acb->qiov_offset += acb->cur_qiov.size; 1349 acb->cur_pos += acb->cur_qiov.size; 1350 qemu_iovec_reset(&acb->cur_qiov); 1351 1352 /* Complete request */ 1353 if (acb->cur_pos >= acb->end_pos) { 1354 qed_aio_complete(acb, 0); 1355 return; 1356 } 1357 1358 /* Find next cluster and start I/O */ 1359 qed_find_cluster(s, &acb->request, 1360 acb->cur_pos, acb->end_pos - acb->cur_pos, 1361 io_fn, acb); 1362 } 1363 1364 static BlockDriverAIOCB *qed_aio_setup(BlockDriverState *bs, 1365 int64_t sector_num, 1366 QEMUIOVector *qiov, int nb_sectors, 1367 BlockDriverCompletionFunc *cb, 1368 void *opaque, int flags) 1369 { 1370 QEDAIOCB *acb = qemu_aio_get(&qed_aiocb_info, bs, cb, opaque); 1371 1372 trace_qed_aio_setup(bs->opaque, acb, sector_num, nb_sectors, 1373 opaque, flags); 1374 1375 acb->flags = flags; 1376 acb->finished = NULL; 1377 acb->qiov = qiov; 1378 acb->qiov_offset = 0; 1379 acb->cur_pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE; 1380 acb->end_pos = acb->cur_pos + nb_sectors * BDRV_SECTOR_SIZE; 1381 acb->request.l2_table = NULL; 1382 qemu_iovec_init(&acb->cur_qiov, qiov->niov); 1383 1384 /* Start request */ 1385 qed_aio_next_io(acb, 0); 1386 return &acb->common; 1387 } 1388 1389 static BlockDriverAIOCB *bdrv_qed_aio_readv(BlockDriverState *bs, 1390 int64_t sector_num, 1391 QEMUIOVector *qiov, int nb_sectors, 1392 BlockDriverCompletionFunc *cb, 1393 void *opaque) 1394 { 1395 return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); 1396 } 1397 1398 static BlockDriverAIOCB *bdrv_qed_aio_writev(BlockDriverState *bs, 1399 int64_t sector_num, 1400 QEMUIOVector *qiov, int nb_sectors, 1401 BlockDriverCompletionFunc *cb, 1402 void *opaque) 1403 { 1404 return qed_aio_setup(bs, sector_num, qiov, nb_sectors, cb, 1405 opaque, QED_AIOCB_WRITE); 1406 } 1407 1408 typedef struct { 1409 Coroutine *co; 1410 int ret; 1411 bool done; 1412 } QEDWriteZeroesCB; 1413 1414 static void coroutine_fn qed_co_write_zeroes_cb(void *opaque, int ret) 1415 { 1416 QEDWriteZeroesCB *cb = opaque; 1417 1418 cb->done = true; 1419 cb->ret = ret; 1420 if (cb->co) { 1421 qemu_coroutine_enter(cb->co, NULL); 1422 } 1423 } 1424 1425 static int coroutine_fn bdrv_qed_co_write_zeroes(BlockDriverState *bs, 1426 int64_t sector_num, 1427 int nb_sectors, 1428 BdrvRequestFlags flags) 1429 { 1430 BlockDriverAIOCB *blockacb; 1431 BDRVQEDState *s = bs->opaque; 1432 QEDWriteZeroesCB cb = { .done = false }; 1433 QEMUIOVector qiov; 1434 struct iovec iov; 1435 1436 /* Refuse if there are untouched backing file sectors */ 1437 if (bs->backing_hd) { 1438 if (qed_offset_into_cluster(s, sector_num * BDRV_SECTOR_SIZE) != 0) { 1439 return -ENOTSUP; 1440 } 1441 if (qed_offset_into_cluster(s, nb_sectors * BDRV_SECTOR_SIZE) != 0) { 1442 return -ENOTSUP; 1443 } 1444 } 1445 1446 /* Zero writes start without an I/O buffer. If a buffer becomes necessary 1447 * then it will be allocated during request processing. 1448 */ 1449 iov.iov_base = NULL, 1450 iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE, 1451 1452 qemu_iovec_init_external(&qiov, &iov, 1); 1453 blockacb = qed_aio_setup(bs, sector_num, &qiov, nb_sectors, 1454 qed_co_write_zeroes_cb, &cb, 1455 QED_AIOCB_WRITE | QED_AIOCB_ZERO); 1456 if (!blockacb) { 1457 return -EIO; 1458 } 1459 if (!cb.done) { 1460 cb.co = qemu_coroutine_self(); 1461 qemu_coroutine_yield(); 1462 } 1463 assert(cb.done); 1464 return cb.ret; 1465 } 1466 1467 static int bdrv_qed_truncate(BlockDriverState *bs, int64_t offset) 1468 { 1469 BDRVQEDState *s = bs->opaque; 1470 uint64_t old_image_size; 1471 int ret; 1472 1473 if (!qed_is_image_size_valid(offset, s->header.cluster_size, 1474 s->header.table_size)) { 1475 return -EINVAL; 1476 } 1477 1478 /* Shrinking is currently not supported */ 1479 if ((uint64_t)offset < s->header.image_size) { 1480 return -ENOTSUP; 1481 } 1482 1483 old_image_size = s->header.image_size; 1484 s->header.image_size = offset; 1485 ret = qed_write_header_sync(s); 1486 if (ret < 0) { 1487 s->header.image_size = old_image_size; 1488 } 1489 return ret; 1490 } 1491 1492 static int64_t bdrv_qed_getlength(BlockDriverState *bs) 1493 { 1494 BDRVQEDState *s = bs->opaque; 1495 return s->header.image_size; 1496 } 1497 1498 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1499 { 1500 BDRVQEDState *s = bs->opaque; 1501 1502 memset(bdi, 0, sizeof(*bdi)); 1503 bdi->cluster_size = s->header.cluster_size; 1504 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK; 1505 bdi->unallocated_blocks_are_zero = true; 1506 bdi->can_write_zeroes_with_unmap = true; 1507 return 0; 1508 } 1509 1510 static int bdrv_qed_change_backing_file(BlockDriverState *bs, 1511 const char *backing_file, 1512 const char *backing_fmt) 1513 { 1514 BDRVQEDState *s = bs->opaque; 1515 QEDHeader new_header, le_header; 1516 void *buffer; 1517 size_t buffer_len, backing_file_len; 1518 int ret; 1519 1520 /* Refuse to set backing filename if unknown compat feature bits are 1521 * active. If the image uses an unknown compat feature then we may not 1522 * know the layout of data following the header structure and cannot safely 1523 * add a new string. 1524 */ 1525 if (backing_file && (s->header.compat_features & 1526 ~QED_COMPAT_FEATURE_MASK)) { 1527 return -ENOTSUP; 1528 } 1529 1530 memcpy(&new_header, &s->header, sizeof(new_header)); 1531 1532 new_header.features &= ~(QED_F_BACKING_FILE | 1533 QED_F_BACKING_FORMAT_NO_PROBE); 1534 1535 /* Adjust feature flags */ 1536 if (backing_file) { 1537 new_header.features |= QED_F_BACKING_FILE; 1538 1539 if (qed_fmt_is_raw(backing_fmt)) { 1540 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 1541 } 1542 } 1543 1544 /* Calculate new header size */ 1545 backing_file_len = 0; 1546 1547 if (backing_file) { 1548 backing_file_len = strlen(backing_file); 1549 } 1550 1551 buffer_len = sizeof(new_header); 1552 new_header.backing_filename_offset = buffer_len; 1553 new_header.backing_filename_size = backing_file_len; 1554 buffer_len += backing_file_len; 1555 1556 /* Make sure we can rewrite header without failing */ 1557 if (buffer_len > new_header.header_size * new_header.cluster_size) { 1558 return -ENOSPC; 1559 } 1560 1561 /* Prepare new header */ 1562 buffer = g_malloc(buffer_len); 1563 1564 qed_header_cpu_to_le(&new_header, &le_header); 1565 memcpy(buffer, &le_header, sizeof(le_header)); 1566 buffer_len = sizeof(le_header); 1567 1568 if (backing_file) { 1569 memcpy(buffer + buffer_len, backing_file, backing_file_len); 1570 buffer_len += backing_file_len; 1571 } 1572 1573 /* Write new header */ 1574 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len); 1575 g_free(buffer); 1576 if (ret == 0) { 1577 memcpy(&s->header, &new_header, sizeof(new_header)); 1578 } 1579 return ret; 1580 } 1581 1582 static void bdrv_qed_invalidate_cache(BlockDriverState *bs, Error **errp) 1583 { 1584 BDRVQEDState *s = bs->opaque; 1585 Error *local_err = NULL; 1586 int ret; 1587 1588 bdrv_qed_close(bs); 1589 1590 bdrv_invalidate_cache(bs->file, &local_err); 1591 if (local_err) { 1592 error_propagate(errp, local_err); 1593 return; 1594 } 1595 1596 memset(s, 0, sizeof(BDRVQEDState)); 1597 ret = bdrv_qed_open(bs, NULL, bs->open_flags, &local_err); 1598 if (local_err) { 1599 error_setg(errp, "Could not reopen qed layer: %s", 1600 error_get_pretty(local_err)); 1601 error_free(local_err); 1602 return; 1603 } else if (ret < 0) { 1604 error_setg_errno(errp, -ret, "Could not reopen qed layer"); 1605 return; 1606 } 1607 } 1608 1609 static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result, 1610 BdrvCheckMode fix) 1611 { 1612 BDRVQEDState *s = bs->opaque; 1613 1614 return qed_check(s, result, !!fix); 1615 } 1616 1617 static QemuOptsList qed_create_opts = { 1618 .name = "qed-create-opts", 1619 .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head), 1620 .desc = { 1621 { 1622 .name = BLOCK_OPT_SIZE, 1623 .type = QEMU_OPT_SIZE, 1624 .help = "Virtual disk size" 1625 }, 1626 { 1627 .name = BLOCK_OPT_BACKING_FILE, 1628 .type = QEMU_OPT_STRING, 1629 .help = "File name of a base image" 1630 }, 1631 { 1632 .name = BLOCK_OPT_BACKING_FMT, 1633 .type = QEMU_OPT_STRING, 1634 .help = "Image format of the base image" 1635 }, 1636 { 1637 .name = BLOCK_OPT_CLUSTER_SIZE, 1638 .type = QEMU_OPT_SIZE, 1639 .help = "Cluster size (in bytes)", 1640 .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE) 1641 }, 1642 { 1643 .name = BLOCK_OPT_TABLE_SIZE, 1644 .type = QEMU_OPT_SIZE, 1645 .help = "L1/L2 table size (in clusters)" 1646 }, 1647 { /* end of list */ } 1648 } 1649 }; 1650 1651 static BlockDriver bdrv_qed = { 1652 .format_name = "qed", 1653 .instance_size = sizeof(BDRVQEDState), 1654 .create_opts = &qed_create_opts, 1655 .supports_backing = true, 1656 1657 .bdrv_probe = bdrv_qed_probe, 1658 .bdrv_rebind = bdrv_qed_rebind, 1659 .bdrv_open = bdrv_qed_open, 1660 .bdrv_close = bdrv_qed_close, 1661 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare, 1662 .bdrv_create = bdrv_qed_create, 1663 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1664 .bdrv_co_get_block_status = bdrv_qed_co_get_block_status, 1665 .bdrv_aio_readv = bdrv_qed_aio_readv, 1666 .bdrv_aio_writev = bdrv_qed_aio_writev, 1667 .bdrv_co_write_zeroes = bdrv_qed_co_write_zeroes, 1668 .bdrv_truncate = bdrv_qed_truncate, 1669 .bdrv_getlength = bdrv_qed_getlength, 1670 .bdrv_get_info = bdrv_qed_get_info, 1671 .bdrv_refresh_limits = bdrv_qed_refresh_limits, 1672 .bdrv_change_backing_file = bdrv_qed_change_backing_file, 1673 .bdrv_invalidate_cache = bdrv_qed_invalidate_cache, 1674 .bdrv_check = bdrv_qed_check, 1675 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context, 1676 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context, 1677 }; 1678 1679 static void bdrv_qed_init(void) 1680 { 1681 bdrv_register(&bdrv_qed); 1682 } 1683 1684 block_init(bdrv_qed_init); 1685