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/osdep.h" 16 #include "block/qdict.h" 17 #include "qapi/error.h" 18 #include "qemu/timer.h" 19 #include "qemu/bswap.h" 20 #include "qemu/option.h" 21 #include "trace.h" 22 #include "qed.h" 23 #include "sysemu/block-backend.h" 24 #include "qapi/qmp/qdict.h" 25 #include "qapi/qobject-input-visitor.h" 26 #include "qapi/qapi-visit-block-core.h" 27 28 static QemuOptsList qed_create_opts; 29 30 static int bdrv_qed_probe(const uint8_t *buf, int buf_size, 31 const char *filename) 32 { 33 const QEDHeader *header = (const QEDHeader *)buf; 34 35 if (buf_size < sizeof(*header)) { 36 return 0; 37 } 38 if (le32_to_cpu(header->magic) != QED_MAGIC) { 39 return 0; 40 } 41 return 100; 42 } 43 44 /** 45 * Check whether an image format is raw 46 * 47 * @fmt: Backing file format, may be NULL 48 */ 49 static bool qed_fmt_is_raw(const char *fmt) 50 { 51 return fmt && strcmp(fmt, "raw") == 0; 52 } 53 54 static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu) 55 { 56 cpu->magic = le32_to_cpu(le->magic); 57 cpu->cluster_size = le32_to_cpu(le->cluster_size); 58 cpu->table_size = le32_to_cpu(le->table_size); 59 cpu->header_size = le32_to_cpu(le->header_size); 60 cpu->features = le64_to_cpu(le->features); 61 cpu->compat_features = le64_to_cpu(le->compat_features); 62 cpu->autoclear_features = le64_to_cpu(le->autoclear_features); 63 cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset); 64 cpu->image_size = le64_to_cpu(le->image_size); 65 cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset); 66 cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size); 67 } 68 69 static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le) 70 { 71 le->magic = cpu_to_le32(cpu->magic); 72 le->cluster_size = cpu_to_le32(cpu->cluster_size); 73 le->table_size = cpu_to_le32(cpu->table_size); 74 le->header_size = cpu_to_le32(cpu->header_size); 75 le->features = cpu_to_le64(cpu->features); 76 le->compat_features = cpu_to_le64(cpu->compat_features); 77 le->autoclear_features = cpu_to_le64(cpu->autoclear_features); 78 le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset); 79 le->image_size = cpu_to_le64(cpu->image_size); 80 le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset); 81 le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size); 82 } 83 84 int qed_write_header_sync(BDRVQEDState *s) 85 { 86 QEDHeader le; 87 int ret; 88 89 qed_header_cpu_to_le(&s->header, &le); 90 ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le)); 91 if (ret != sizeof(le)) { 92 return ret; 93 } 94 return 0; 95 } 96 97 /** 98 * Update header in-place (does not rewrite backing filename or other strings) 99 * 100 * This function only updates known header fields in-place and does not affect 101 * extra data after the QED header. 102 * 103 * No new allocating reqs can start while this function runs. 104 */ 105 static int coroutine_fn qed_write_header(BDRVQEDState *s) 106 { 107 /* We must write full sectors for O_DIRECT but cannot necessarily generate 108 * the data following the header if an unrecognized compat feature is 109 * active. Therefore, first read the sectors containing the header, update 110 * them, and write back. 111 */ 112 113 int nsectors = DIV_ROUND_UP(sizeof(QEDHeader), BDRV_SECTOR_SIZE); 114 size_t len = nsectors * BDRV_SECTOR_SIZE; 115 uint8_t *buf; 116 int ret; 117 118 assert(s->allocating_acb || s->allocating_write_reqs_plugged); 119 120 buf = qemu_blockalign(s->bs, len); 121 122 ret = bdrv_co_pread(s->bs->file, 0, len, buf, 0); 123 if (ret < 0) { 124 goto out; 125 } 126 127 /* Update header */ 128 qed_header_cpu_to_le(&s->header, (QEDHeader *) buf); 129 130 ret = bdrv_co_pwrite(s->bs->file, 0, len, buf, 0); 131 if (ret < 0) { 132 goto out; 133 } 134 135 ret = 0; 136 out: 137 qemu_vfree(buf); 138 return ret; 139 } 140 141 static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size) 142 { 143 uint64_t table_entries; 144 uint64_t l2_size; 145 146 table_entries = (table_size * cluster_size) / sizeof(uint64_t); 147 l2_size = table_entries * cluster_size; 148 149 return l2_size * table_entries; 150 } 151 152 static bool qed_is_cluster_size_valid(uint32_t cluster_size) 153 { 154 if (cluster_size < QED_MIN_CLUSTER_SIZE || 155 cluster_size > QED_MAX_CLUSTER_SIZE) { 156 return false; 157 } 158 if (cluster_size & (cluster_size - 1)) { 159 return false; /* not power of 2 */ 160 } 161 return true; 162 } 163 164 static bool qed_is_table_size_valid(uint32_t table_size) 165 { 166 if (table_size < QED_MIN_TABLE_SIZE || 167 table_size > QED_MAX_TABLE_SIZE) { 168 return false; 169 } 170 if (table_size & (table_size - 1)) { 171 return false; /* not power of 2 */ 172 } 173 return true; 174 } 175 176 static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size, 177 uint32_t table_size) 178 { 179 if (image_size % BDRV_SECTOR_SIZE != 0) { 180 return false; /* not multiple of sector size */ 181 } 182 if (image_size > qed_max_image_size(cluster_size, table_size)) { 183 return false; /* image is too large */ 184 } 185 return true; 186 } 187 188 /** 189 * Read a string of known length from the image file 190 * 191 * @file: Image file 192 * @offset: File offset to start of string, in bytes 193 * @n: String length in bytes 194 * @buf: Destination buffer 195 * @buflen: Destination buffer length in bytes 196 * @ret: 0 on success, -errno on failure 197 * 198 * The string is NUL-terminated. 199 */ 200 static int qed_read_string(BdrvChild *file, uint64_t offset, size_t n, 201 char *buf, size_t buflen) 202 { 203 int ret; 204 if (n >= buflen) { 205 return -EINVAL; 206 } 207 ret = bdrv_pread(file, offset, buf, n); 208 if (ret < 0) { 209 return ret; 210 } 211 buf[n] = '\0'; 212 return 0; 213 } 214 215 /** 216 * Allocate new clusters 217 * 218 * @s: QED state 219 * @n: Number of contiguous clusters to allocate 220 * @ret: Offset of first allocated cluster 221 * 222 * This function only produces the offset where the new clusters should be 223 * written. It updates BDRVQEDState but does not make any changes to the image 224 * file. 225 * 226 * Called with table_lock held. 227 */ 228 static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n) 229 { 230 uint64_t offset = s->file_size; 231 s->file_size += n * s->header.cluster_size; 232 return offset; 233 } 234 235 QEDTable *qed_alloc_table(BDRVQEDState *s) 236 { 237 /* Honor O_DIRECT memory alignment requirements */ 238 return qemu_blockalign(s->bs, 239 s->header.cluster_size * s->header.table_size); 240 } 241 242 /** 243 * Allocate a new zeroed L2 table 244 * 245 * Called with table_lock held. 246 */ 247 static CachedL2Table *qed_new_l2_table(BDRVQEDState *s) 248 { 249 CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); 250 251 l2_table->table = qed_alloc_table(s); 252 l2_table->offset = qed_alloc_clusters(s, s->header.table_size); 253 254 memset(l2_table->table->offsets, 0, 255 s->header.cluster_size * s->header.table_size); 256 return l2_table; 257 } 258 259 static bool qed_plug_allocating_write_reqs(BDRVQEDState *s) 260 { 261 qemu_co_mutex_lock(&s->table_lock); 262 263 /* No reentrancy is allowed. */ 264 assert(!s->allocating_write_reqs_plugged); 265 if (s->allocating_acb != NULL) { 266 /* Another allocating write came concurrently. This cannot happen 267 * from bdrv_qed_co_drain_begin, but it can happen when the timer runs. 268 */ 269 qemu_co_mutex_unlock(&s->table_lock); 270 return false; 271 } 272 273 s->allocating_write_reqs_plugged = true; 274 qemu_co_mutex_unlock(&s->table_lock); 275 return true; 276 } 277 278 static void qed_unplug_allocating_write_reqs(BDRVQEDState *s) 279 { 280 qemu_co_mutex_lock(&s->table_lock); 281 assert(s->allocating_write_reqs_plugged); 282 s->allocating_write_reqs_plugged = false; 283 qemu_co_queue_next(&s->allocating_write_reqs); 284 qemu_co_mutex_unlock(&s->table_lock); 285 } 286 287 static void coroutine_fn qed_need_check_timer_entry(void *opaque) 288 { 289 BDRVQEDState *s = opaque; 290 int ret; 291 292 trace_qed_need_check_timer_cb(s); 293 294 if (!qed_plug_allocating_write_reqs(s)) { 295 return; 296 } 297 298 /* Ensure writes are on disk before clearing flag */ 299 ret = bdrv_co_flush(s->bs->file->bs); 300 if (ret < 0) { 301 qed_unplug_allocating_write_reqs(s); 302 return; 303 } 304 305 s->header.features &= ~QED_F_NEED_CHECK; 306 ret = qed_write_header(s); 307 (void) ret; 308 309 qed_unplug_allocating_write_reqs(s); 310 311 ret = bdrv_co_flush(s->bs); 312 (void) ret; 313 } 314 315 static void qed_need_check_timer_cb(void *opaque) 316 { 317 Coroutine *co = qemu_coroutine_create(qed_need_check_timer_entry, opaque); 318 qemu_coroutine_enter(co); 319 } 320 321 static void qed_start_need_check_timer(BDRVQEDState *s) 322 { 323 trace_qed_start_need_check_timer(s); 324 325 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for 326 * migration. 327 */ 328 timer_mod(s->need_check_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 329 NANOSECONDS_PER_SECOND * QED_NEED_CHECK_TIMEOUT); 330 } 331 332 /* It's okay to call this multiple times or when no timer is started */ 333 static void qed_cancel_need_check_timer(BDRVQEDState *s) 334 { 335 trace_qed_cancel_need_check_timer(s); 336 timer_del(s->need_check_timer); 337 } 338 339 static void bdrv_qed_detach_aio_context(BlockDriverState *bs) 340 { 341 BDRVQEDState *s = bs->opaque; 342 343 qed_cancel_need_check_timer(s); 344 timer_free(s->need_check_timer); 345 } 346 347 static void bdrv_qed_attach_aio_context(BlockDriverState *bs, 348 AioContext *new_context) 349 { 350 BDRVQEDState *s = bs->opaque; 351 352 s->need_check_timer = aio_timer_new(new_context, 353 QEMU_CLOCK_VIRTUAL, SCALE_NS, 354 qed_need_check_timer_cb, s); 355 if (s->header.features & QED_F_NEED_CHECK) { 356 qed_start_need_check_timer(s); 357 } 358 } 359 360 static void coroutine_fn bdrv_qed_co_drain_begin(BlockDriverState *bs) 361 { 362 BDRVQEDState *s = bs->opaque; 363 364 /* Fire the timer immediately in order to start doing I/O as soon as the 365 * header is flushed. 366 */ 367 if (s->need_check_timer && timer_pending(s->need_check_timer)) { 368 qed_cancel_need_check_timer(s); 369 qed_need_check_timer_entry(s); 370 } 371 } 372 373 static void bdrv_qed_init_state(BlockDriverState *bs) 374 { 375 BDRVQEDState *s = bs->opaque; 376 377 memset(s, 0, sizeof(BDRVQEDState)); 378 s->bs = bs; 379 qemu_co_mutex_init(&s->table_lock); 380 qemu_co_queue_init(&s->allocating_write_reqs); 381 } 382 383 /* Called with table_lock held. */ 384 static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options, 385 int flags, Error **errp) 386 { 387 BDRVQEDState *s = bs->opaque; 388 QEDHeader le_header; 389 int64_t file_size; 390 int ret; 391 392 ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header)); 393 if (ret < 0) { 394 return ret; 395 } 396 qed_header_le_to_cpu(&le_header, &s->header); 397 398 if (s->header.magic != QED_MAGIC) { 399 error_setg(errp, "Image not in QED format"); 400 return -EINVAL; 401 } 402 if (s->header.features & ~QED_FEATURE_MASK) { 403 /* image uses unsupported feature bits */ 404 error_setg(errp, "Unsupported QED features: %" PRIx64, 405 s->header.features & ~QED_FEATURE_MASK); 406 return -ENOTSUP; 407 } 408 if (!qed_is_cluster_size_valid(s->header.cluster_size)) { 409 return -EINVAL; 410 } 411 412 /* Round down file size to the last cluster */ 413 file_size = bdrv_getlength(bs->file->bs); 414 if (file_size < 0) { 415 return file_size; 416 } 417 s->file_size = qed_start_of_cluster(s, file_size); 418 419 if (!qed_is_table_size_valid(s->header.table_size)) { 420 return -EINVAL; 421 } 422 if (!qed_is_image_size_valid(s->header.image_size, 423 s->header.cluster_size, 424 s->header.table_size)) { 425 return -EINVAL; 426 } 427 if (!qed_check_table_offset(s, s->header.l1_table_offset)) { 428 return -EINVAL; 429 } 430 431 s->table_nelems = (s->header.cluster_size * s->header.table_size) / 432 sizeof(uint64_t); 433 s->l2_shift = ctz32(s->header.cluster_size); 434 s->l2_mask = s->table_nelems - 1; 435 s->l1_shift = s->l2_shift + ctz32(s->table_nelems); 436 437 /* Header size calculation must not overflow uint32_t */ 438 if (s->header.header_size > UINT32_MAX / s->header.cluster_size) { 439 return -EINVAL; 440 } 441 442 if ((s->header.features & QED_F_BACKING_FILE)) { 443 if ((uint64_t)s->header.backing_filename_offset + 444 s->header.backing_filename_size > 445 s->header.cluster_size * s->header.header_size) { 446 return -EINVAL; 447 } 448 449 ret = qed_read_string(bs->file, s->header.backing_filename_offset, 450 s->header.backing_filename_size, 451 bs->auto_backing_file, 452 sizeof(bs->auto_backing_file)); 453 if (ret < 0) { 454 return ret; 455 } 456 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 457 bs->auto_backing_file); 458 459 if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) { 460 pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw"); 461 } 462 } 463 464 /* Reset unknown autoclear feature bits. This is a backwards 465 * compatibility mechanism that allows images to be opened by older 466 * programs, which "knock out" unknown feature bits. When an image is 467 * opened by a newer program again it can detect that the autoclear 468 * feature is no longer valid. 469 */ 470 if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 && 471 !bdrv_is_read_only(bs->file->bs) && !(flags & BDRV_O_INACTIVE)) { 472 s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK; 473 474 ret = qed_write_header_sync(s); 475 if (ret) { 476 return ret; 477 } 478 479 /* From here on only known autoclear feature bits are valid */ 480 bdrv_flush(bs->file->bs); 481 } 482 483 s->l1_table = qed_alloc_table(s); 484 qed_init_l2_cache(&s->l2_cache); 485 486 ret = qed_read_l1_table_sync(s); 487 if (ret) { 488 goto out; 489 } 490 491 /* If image was not closed cleanly, check consistency */ 492 if (!(flags & BDRV_O_CHECK) && (s->header.features & QED_F_NEED_CHECK)) { 493 /* Read-only images cannot be fixed. There is no risk of corruption 494 * since write operations are not possible. Therefore, allow 495 * potentially inconsistent images to be opened read-only. This can 496 * aid data recovery from an otherwise inconsistent image. 497 */ 498 if (!bdrv_is_read_only(bs->file->bs) && 499 !(flags & BDRV_O_INACTIVE)) { 500 BdrvCheckResult result = {0}; 501 502 ret = qed_check(s, &result, true); 503 if (ret) { 504 goto out; 505 } 506 } 507 } 508 509 bdrv_qed_attach_aio_context(bs, bdrv_get_aio_context(bs)); 510 511 out: 512 if (ret) { 513 qed_free_l2_cache(&s->l2_cache); 514 qemu_vfree(s->l1_table); 515 } 516 return ret; 517 } 518 519 typedef struct QEDOpenCo { 520 BlockDriverState *bs; 521 QDict *options; 522 int flags; 523 Error **errp; 524 int ret; 525 } QEDOpenCo; 526 527 static void coroutine_fn bdrv_qed_open_entry(void *opaque) 528 { 529 QEDOpenCo *qoc = opaque; 530 BDRVQEDState *s = qoc->bs->opaque; 531 532 qemu_co_mutex_lock(&s->table_lock); 533 qoc->ret = bdrv_qed_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp); 534 qemu_co_mutex_unlock(&s->table_lock); 535 } 536 537 static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags, 538 Error **errp) 539 { 540 QEDOpenCo qoc = { 541 .bs = bs, 542 .options = options, 543 .flags = flags, 544 .errp = errp, 545 .ret = -EINPROGRESS 546 }; 547 548 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, 549 false, errp); 550 if (!bs->file) { 551 return -EINVAL; 552 } 553 554 bdrv_qed_init_state(bs); 555 if (qemu_in_coroutine()) { 556 bdrv_qed_open_entry(&qoc); 557 } else { 558 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 559 qemu_coroutine_enter(qemu_coroutine_create(bdrv_qed_open_entry, &qoc)); 560 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); 561 } 562 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); 563 return qoc.ret; 564 } 565 566 static void bdrv_qed_refresh_limits(BlockDriverState *bs, Error **errp) 567 { 568 BDRVQEDState *s = bs->opaque; 569 570 bs->bl.pwrite_zeroes_alignment = s->header.cluster_size; 571 } 572 573 /* We have nothing to do for QED reopen, stubs just return 574 * success */ 575 static int bdrv_qed_reopen_prepare(BDRVReopenState *state, 576 BlockReopenQueue *queue, Error **errp) 577 { 578 return 0; 579 } 580 581 static void bdrv_qed_close(BlockDriverState *bs) 582 { 583 BDRVQEDState *s = bs->opaque; 584 585 bdrv_qed_detach_aio_context(bs); 586 587 /* Ensure writes reach stable storage */ 588 bdrv_flush(bs->file->bs); 589 590 /* Clean shutdown, no check required on next open */ 591 if (s->header.features & QED_F_NEED_CHECK) { 592 s->header.features &= ~QED_F_NEED_CHECK; 593 qed_write_header_sync(s); 594 } 595 596 qed_free_l2_cache(&s->l2_cache); 597 qemu_vfree(s->l1_table); 598 } 599 600 static int coroutine_fn bdrv_qed_co_create(BlockdevCreateOptions *opts, 601 Error **errp) 602 { 603 BlockdevCreateOptionsQed *qed_opts; 604 BlockBackend *blk = NULL; 605 BlockDriverState *bs = NULL; 606 607 QEDHeader header; 608 QEDHeader le_header; 609 uint8_t *l1_table = NULL; 610 size_t l1_size; 611 int ret = 0; 612 613 assert(opts->driver == BLOCKDEV_DRIVER_QED); 614 qed_opts = &opts->u.qed; 615 616 /* Validate options and set default values */ 617 if (!qed_opts->has_cluster_size) { 618 qed_opts->cluster_size = QED_DEFAULT_CLUSTER_SIZE; 619 } 620 if (!qed_opts->has_table_size) { 621 qed_opts->table_size = QED_DEFAULT_TABLE_SIZE; 622 } 623 624 if (!qed_is_cluster_size_valid(qed_opts->cluster_size)) { 625 error_setg(errp, "QED cluster size must be within range [%u, %u] " 626 "and power of 2", 627 QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE); 628 return -EINVAL; 629 } 630 if (!qed_is_table_size_valid(qed_opts->table_size)) { 631 error_setg(errp, "QED table size must be within range [%u, %u] " 632 "and power of 2", 633 QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE); 634 return -EINVAL; 635 } 636 if (!qed_is_image_size_valid(qed_opts->size, qed_opts->cluster_size, 637 qed_opts->table_size)) 638 { 639 error_setg(errp, "QED image size must be a non-zero multiple of " 640 "cluster size and less than %" PRIu64 " bytes", 641 qed_max_image_size(qed_opts->cluster_size, 642 qed_opts->table_size)); 643 return -EINVAL; 644 } 645 646 /* Create BlockBackend to write to the image */ 647 bs = bdrv_open_blockdev_ref(qed_opts->file, errp); 648 if (bs == NULL) { 649 return -EIO; 650 } 651 652 blk = blk_new(bdrv_get_aio_context(bs), 653 BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL); 654 ret = blk_insert_bs(blk, bs, errp); 655 if (ret < 0) { 656 goto out; 657 } 658 blk_set_allow_write_beyond_eof(blk, true); 659 660 /* Prepare image format */ 661 header = (QEDHeader) { 662 .magic = QED_MAGIC, 663 .cluster_size = qed_opts->cluster_size, 664 .table_size = qed_opts->table_size, 665 .header_size = 1, 666 .features = 0, 667 .compat_features = 0, 668 .l1_table_offset = qed_opts->cluster_size, 669 .image_size = qed_opts->size, 670 }; 671 672 l1_size = header.cluster_size * header.table_size; 673 674 /* File must start empty and grow, check truncate is supported */ 675 ret = blk_truncate(blk, 0, PREALLOC_MODE_OFF, errp); 676 if (ret < 0) { 677 goto out; 678 } 679 680 if (qed_opts->has_backing_file) { 681 header.features |= QED_F_BACKING_FILE; 682 header.backing_filename_offset = sizeof(le_header); 683 header.backing_filename_size = strlen(qed_opts->backing_file); 684 685 if (qed_opts->has_backing_fmt) { 686 const char *backing_fmt = BlockdevDriver_str(qed_opts->backing_fmt); 687 if (qed_fmt_is_raw(backing_fmt)) { 688 header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 689 } 690 } 691 } 692 693 qed_header_cpu_to_le(&header, &le_header); 694 ret = blk_pwrite(blk, 0, &le_header, sizeof(le_header), 0); 695 if (ret < 0) { 696 goto out; 697 } 698 ret = blk_pwrite(blk, sizeof(le_header), qed_opts->backing_file, 699 header.backing_filename_size, 0); 700 if (ret < 0) { 701 goto out; 702 } 703 704 l1_table = g_malloc0(l1_size); 705 ret = blk_pwrite(blk, header.l1_table_offset, l1_table, l1_size, 0); 706 if (ret < 0) { 707 goto out; 708 } 709 710 ret = 0; /* success */ 711 out: 712 g_free(l1_table); 713 blk_unref(blk); 714 bdrv_unref(bs); 715 return ret; 716 } 717 718 static int coroutine_fn bdrv_qed_co_create_opts(const char *filename, 719 QemuOpts *opts, 720 Error **errp) 721 { 722 BlockdevCreateOptions *create_options = NULL; 723 QDict *qdict; 724 Visitor *v; 725 BlockDriverState *bs = NULL; 726 Error *local_err = NULL; 727 int ret; 728 729 static const QDictRenames opt_renames[] = { 730 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 731 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 732 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 733 { BLOCK_OPT_TABLE_SIZE, "table-size" }, 734 { NULL, NULL }, 735 }; 736 737 /* Parse options and convert legacy syntax */ 738 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qed_create_opts, true); 739 740 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 741 ret = -EINVAL; 742 goto fail; 743 } 744 745 /* Create and open the file (protocol layer) */ 746 ret = bdrv_create_file(filename, opts, &local_err); 747 if (ret < 0) { 748 error_propagate(errp, local_err); 749 goto fail; 750 } 751 752 bs = bdrv_open(filename, NULL, NULL, 753 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 754 if (bs == NULL) { 755 ret = -EIO; 756 goto fail; 757 } 758 759 /* Now get the QAPI type BlockdevCreateOptions */ 760 qdict_put_str(qdict, "driver", "qed"); 761 qdict_put_str(qdict, "file", bs->node_name); 762 763 v = qobject_input_visitor_new_flat_confused(qdict, errp); 764 if (!v) { 765 ret = -EINVAL; 766 goto fail; 767 } 768 769 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); 770 visit_free(v); 771 772 if (local_err) { 773 error_propagate(errp, local_err); 774 ret = -EINVAL; 775 goto fail; 776 } 777 778 /* Silently round up size */ 779 assert(create_options->driver == BLOCKDEV_DRIVER_QED); 780 create_options->u.qed.size = 781 ROUND_UP(create_options->u.qed.size, BDRV_SECTOR_SIZE); 782 783 /* Create the qed image (format layer) */ 784 ret = bdrv_qed_co_create(create_options, errp); 785 786 fail: 787 qobject_unref(qdict); 788 bdrv_unref(bs); 789 qapi_free_BlockdevCreateOptions(create_options); 790 return ret; 791 } 792 793 static int coroutine_fn bdrv_qed_co_block_status(BlockDriverState *bs, 794 bool want_zero, 795 int64_t pos, int64_t bytes, 796 int64_t *pnum, int64_t *map, 797 BlockDriverState **file) 798 { 799 BDRVQEDState *s = bs->opaque; 800 size_t len = MIN(bytes, SIZE_MAX); 801 int status; 802 QEDRequest request = { .l2_table = NULL }; 803 uint64_t offset; 804 int ret; 805 806 qemu_co_mutex_lock(&s->table_lock); 807 ret = qed_find_cluster(s, &request, pos, &len, &offset); 808 809 *pnum = len; 810 switch (ret) { 811 case QED_CLUSTER_FOUND: 812 *map = offset | qed_offset_into_cluster(s, pos); 813 status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 814 *file = bs->file->bs; 815 break; 816 case QED_CLUSTER_ZERO: 817 status = BDRV_BLOCK_ZERO; 818 break; 819 case QED_CLUSTER_L2: 820 case QED_CLUSTER_L1: 821 status = 0; 822 break; 823 default: 824 assert(ret < 0); 825 status = ret; 826 break; 827 } 828 829 qed_unref_l2_cache_entry(request.l2_table); 830 qemu_co_mutex_unlock(&s->table_lock); 831 832 return status; 833 } 834 835 static BDRVQEDState *acb_to_s(QEDAIOCB *acb) 836 { 837 return acb->bs->opaque; 838 } 839 840 /** 841 * Read from the backing file or zero-fill if no backing file 842 * 843 * @s: QED state 844 * @pos: Byte position in device 845 * @qiov: Destination I/O vector 846 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here 847 * @cb: Completion function 848 * @opaque: User data for completion function 849 * 850 * This function reads qiov->size bytes starting at pos from the backing file. 851 * If there is no backing file then zeroes are read. 852 */ 853 static int coroutine_fn qed_read_backing_file(BDRVQEDState *s, uint64_t pos, 854 QEMUIOVector *qiov, 855 QEMUIOVector **backing_qiov) 856 { 857 uint64_t backing_length = 0; 858 size_t size; 859 int ret; 860 861 /* If there is a backing file, get its length. Treat the absence of a 862 * backing file like a zero length backing file. 863 */ 864 if (s->bs->backing) { 865 int64_t l = bdrv_getlength(s->bs->backing->bs); 866 if (l < 0) { 867 return l; 868 } 869 backing_length = l; 870 } 871 872 /* Zero all sectors if reading beyond the end of the backing file */ 873 if (pos >= backing_length || 874 pos + qiov->size > backing_length) { 875 qemu_iovec_memset(qiov, 0, 0, qiov->size); 876 } 877 878 /* Complete now if there are no backing file sectors to read */ 879 if (pos >= backing_length) { 880 return 0; 881 } 882 883 /* If the read straddles the end of the backing file, shorten it */ 884 size = MIN((uint64_t)backing_length - pos, qiov->size); 885 886 assert(*backing_qiov == NULL); 887 *backing_qiov = g_new(QEMUIOVector, 1); 888 qemu_iovec_init(*backing_qiov, qiov->niov); 889 qemu_iovec_concat(*backing_qiov, qiov, 0, size); 890 891 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); 892 ret = bdrv_co_preadv(s->bs->backing, pos, size, *backing_qiov, 0); 893 if (ret < 0) { 894 return ret; 895 } 896 return 0; 897 } 898 899 /** 900 * Copy data from backing file into the image 901 * 902 * @s: QED state 903 * @pos: Byte position in device 904 * @len: Number of bytes 905 * @offset: Byte offset in image file 906 */ 907 static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s, 908 uint64_t pos, uint64_t len, 909 uint64_t offset) 910 { 911 QEMUIOVector qiov; 912 QEMUIOVector *backing_qiov = NULL; 913 int ret; 914 915 /* Skip copy entirely if there is no work to do */ 916 if (len == 0) { 917 return 0; 918 } 919 920 qemu_iovec_init_buf(&qiov, qemu_blockalign(s->bs, len), len); 921 922 ret = qed_read_backing_file(s, pos, &qiov, &backing_qiov); 923 924 if (backing_qiov) { 925 qemu_iovec_destroy(backing_qiov); 926 g_free(backing_qiov); 927 backing_qiov = NULL; 928 } 929 930 if (ret) { 931 goto out; 932 } 933 934 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); 935 ret = bdrv_co_pwritev(s->bs->file, offset, qiov.size, &qiov, 0); 936 if (ret < 0) { 937 goto out; 938 } 939 ret = 0; 940 out: 941 qemu_vfree(qemu_iovec_buf(&qiov)); 942 return ret; 943 } 944 945 /** 946 * Link one or more contiguous clusters into a table 947 * 948 * @s: QED state 949 * @table: L2 table 950 * @index: First cluster index 951 * @n: Number of contiguous clusters 952 * @cluster: First cluster offset 953 * 954 * The cluster offset may be an allocated byte offset in the image file, the 955 * zero cluster marker, or the unallocated cluster marker. 956 * 957 * Called with table_lock held. 958 */ 959 static void coroutine_fn qed_update_l2_table(BDRVQEDState *s, QEDTable *table, 960 int index, unsigned int n, 961 uint64_t cluster) 962 { 963 int i; 964 for (i = index; i < index + n; i++) { 965 table->offsets[i] = cluster; 966 if (!qed_offset_is_unalloc_cluster(cluster) && 967 !qed_offset_is_zero_cluster(cluster)) { 968 cluster += s->header.cluster_size; 969 } 970 } 971 } 972 973 /* Called with table_lock held. */ 974 static void coroutine_fn qed_aio_complete(QEDAIOCB *acb) 975 { 976 BDRVQEDState *s = acb_to_s(acb); 977 978 /* Free resources */ 979 qemu_iovec_destroy(&acb->cur_qiov); 980 qed_unref_l2_cache_entry(acb->request.l2_table); 981 982 /* Free the buffer we may have allocated for zero writes */ 983 if (acb->flags & QED_AIOCB_ZERO) { 984 qemu_vfree(acb->qiov->iov[0].iov_base); 985 acb->qiov->iov[0].iov_base = NULL; 986 } 987 988 /* Start next allocating write request waiting behind this one. Note that 989 * requests enqueue themselves when they first hit an unallocated cluster 990 * but they wait until the entire request is finished before waking up the 991 * next request in the queue. This ensures that we don't cycle through 992 * requests multiple times but rather finish one at a time completely. 993 */ 994 if (acb == s->allocating_acb) { 995 s->allocating_acb = NULL; 996 if (!qemu_co_queue_empty(&s->allocating_write_reqs)) { 997 qemu_co_queue_next(&s->allocating_write_reqs); 998 } else if (s->header.features & QED_F_NEED_CHECK) { 999 qed_start_need_check_timer(s); 1000 } 1001 } 1002 } 1003 1004 /** 1005 * Update L1 table with new L2 table offset and write it out 1006 * 1007 * Called with table_lock held. 1008 */ 1009 static int coroutine_fn qed_aio_write_l1_update(QEDAIOCB *acb) 1010 { 1011 BDRVQEDState *s = acb_to_s(acb); 1012 CachedL2Table *l2_table = acb->request.l2_table; 1013 uint64_t l2_offset = l2_table->offset; 1014 int index, ret; 1015 1016 index = qed_l1_index(s, acb->cur_pos); 1017 s->l1_table->offsets[index] = l2_table->offset; 1018 1019 ret = qed_write_l1_table(s, index, 1); 1020 1021 /* Commit the current L2 table to the cache */ 1022 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 1023 1024 /* This is guaranteed to succeed because we just committed the entry to the 1025 * cache. 1026 */ 1027 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 1028 assert(acb->request.l2_table != NULL); 1029 1030 return ret; 1031 } 1032 1033 1034 /** 1035 * Update L2 table with new cluster offsets and write them out 1036 * 1037 * Called with table_lock held. 1038 */ 1039 static int coroutine_fn qed_aio_write_l2_update(QEDAIOCB *acb, uint64_t offset) 1040 { 1041 BDRVQEDState *s = acb_to_s(acb); 1042 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1; 1043 int index, ret; 1044 1045 if (need_alloc) { 1046 qed_unref_l2_cache_entry(acb->request.l2_table); 1047 acb->request.l2_table = qed_new_l2_table(s); 1048 } 1049 1050 index = qed_l2_index(s, acb->cur_pos); 1051 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, 1052 offset); 1053 1054 if (need_alloc) { 1055 /* Write out the whole new L2 table */ 1056 ret = qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true); 1057 if (ret) { 1058 return ret; 1059 } 1060 return qed_aio_write_l1_update(acb); 1061 } else { 1062 /* Write out only the updated part of the L2 table */ 1063 ret = qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, 1064 false); 1065 if (ret) { 1066 return ret; 1067 } 1068 } 1069 return 0; 1070 } 1071 1072 /** 1073 * Write data to the image file 1074 * 1075 * Called with table_lock *not* held. 1076 */ 1077 static int coroutine_fn qed_aio_write_main(QEDAIOCB *acb) 1078 { 1079 BDRVQEDState *s = acb_to_s(acb); 1080 uint64_t offset = acb->cur_cluster + 1081 qed_offset_into_cluster(s, acb->cur_pos); 1082 1083 trace_qed_aio_write_main(s, acb, 0, offset, acb->cur_qiov.size); 1084 1085 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); 1086 return bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size, 1087 &acb->cur_qiov, 0); 1088 } 1089 1090 /** 1091 * Populate untouched regions of new data cluster 1092 * 1093 * Called with table_lock held. 1094 */ 1095 static int coroutine_fn qed_aio_write_cow(QEDAIOCB *acb) 1096 { 1097 BDRVQEDState *s = acb_to_s(acb); 1098 uint64_t start, len, offset; 1099 int ret; 1100 1101 qemu_co_mutex_unlock(&s->table_lock); 1102 1103 /* Populate front untouched region of new data cluster */ 1104 start = qed_start_of_cluster(s, acb->cur_pos); 1105 len = qed_offset_into_cluster(s, acb->cur_pos); 1106 1107 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); 1108 ret = qed_copy_from_backing_file(s, start, len, acb->cur_cluster); 1109 if (ret < 0) { 1110 goto out; 1111 } 1112 1113 /* Populate back untouched region of new data cluster */ 1114 start = acb->cur_pos + acb->cur_qiov.size; 1115 len = qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start; 1116 offset = acb->cur_cluster + 1117 qed_offset_into_cluster(s, acb->cur_pos) + 1118 acb->cur_qiov.size; 1119 1120 trace_qed_aio_write_postfill(s, acb, start, len, offset); 1121 ret = qed_copy_from_backing_file(s, start, len, offset); 1122 if (ret < 0) { 1123 goto out; 1124 } 1125 1126 ret = qed_aio_write_main(acb); 1127 if (ret < 0) { 1128 goto out; 1129 } 1130 1131 if (s->bs->backing) { 1132 /* 1133 * Flush new data clusters before updating the L2 table 1134 * 1135 * This flush is necessary when a backing file is in use. A crash 1136 * during an allocating write could result in empty clusters in the 1137 * image. If the write only touched a subregion of the cluster, 1138 * then backing image sectors have been lost in the untouched 1139 * region. The solution is to flush after writing a new data 1140 * cluster and before updating the L2 table. 1141 */ 1142 ret = bdrv_co_flush(s->bs->file->bs); 1143 } 1144 1145 out: 1146 qemu_co_mutex_lock(&s->table_lock); 1147 return ret; 1148 } 1149 1150 /** 1151 * Check if the QED_F_NEED_CHECK bit should be set during allocating write 1152 */ 1153 static bool qed_should_set_need_check(BDRVQEDState *s) 1154 { 1155 /* The flush before L2 update path ensures consistency */ 1156 if (s->bs->backing) { 1157 return false; 1158 } 1159 1160 return !(s->header.features & QED_F_NEED_CHECK); 1161 } 1162 1163 /** 1164 * Write new data cluster 1165 * 1166 * @acb: Write request 1167 * @len: Length in bytes 1168 * 1169 * This path is taken when writing to previously unallocated clusters. 1170 * 1171 * Called with table_lock held. 1172 */ 1173 static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 1174 { 1175 BDRVQEDState *s = acb_to_s(acb); 1176 int ret; 1177 1178 /* Cancel timer when the first allocating request comes in */ 1179 if (s->allocating_acb == NULL) { 1180 qed_cancel_need_check_timer(s); 1181 } 1182 1183 /* Freeze this request if another allocating write is in progress */ 1184 if (s->allocating_acb != acb || s->allocating_write_reqs_plugged) { 1185 if (s->allocating_acb != NULL) { 1186 qemu_co_queue_wait(&s->allocating_write_reqs, &s->table_lock); 1187 assert(s->allocating_acb == NULL); 1188 } 1189 s->allocating_acb = acb; 1190 return -EAGAIN; /* start over with looking up table entries */ 1191 } 1192 1193 acb->cur_nclusters = qed_bytes_to_clusters(s, 1194 qed_offset_into_cluster(s, acb->cur_pos) + len); 1195 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1196 1197 if (acb->flags & QED_AIOCB_ZERO) { 1198 /* Skip ahead if the clusters are already zero */ 1199 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) { 1200 return 0; 1201 } 1202 acb->cur_cluster = 1; 1203 } else { 1204 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); 1205 } 1206 1207 if (qed_should_set_need_check(s)) { 1208 s->header.features |= QED_F_NEED_CHECK; 1209 ret = qed_write_header(s); 1210 if (ret < 0) { 1211 return ret; 1212 } 1213 } 1214 1215 if (!(acb->flags & QED_AIOCB_ZERO)) { 1216 ret = qed_aio_write_cow(acb); 1217 if (ret < 0) { 1218 return ret; 1219 } 1220 } 1221 1222 return qed_aio_write_l2_update(acb, acb->cur_cluster); 1223 } 1224 1225 /** 1226 * Write data cluster in place 1227 * 1228 * @acb: Write request 1229 * @offset: Cluster offset in bytes 1230 * @len: Length in bytes 1231 * 1232 * This path is taken when writing to already allocated clusters. 1233 * 1234 * Called with table_lock held. 1235 */ 1236 static int coroutine_fn qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, 1237 size_t len) 1238 { 1239 BDRVQEDState *s = acb_to_s(acb); 1240 int r; 1241 1242 qemu_co_mutex_unlock(&s->table_lock); 1243 1244 /* Allocate buffer for zero writes */ 1245 if (acb->flags & QED_AIOCB_ZERO) { 1246 struct iovec *iov = acb->qiov->iov; 1247 1248 if (!iov->iov_base) { 1249 iov->iov_base = qemu_try_blockalign(acb->bs, iov->iov_len); 1250 if (iov->iov_base == NULL) { 1251 r = -ENOMEM; 1252 goto out; 1253 } 1254 memset(iov->iov_base, 0, iov->iov_len); 1255 } 1256 } 1257 1258 /* Calculate the I/O vector */ 1259 acb->cur_cluster = offset; 1260 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1261 1262 /* Do the actual write. */ 1263 r = qed_aio_write_main(acb); 1264 out: 1265 qemu_co_mutex_lock(&s->table_lock); 1266 return r; 1267 } 1268 1269 /** 1270 * Write data cluster 1271 * 1272 * @opaque: Write request 1273 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1274 * @offset: Cluster offset in bytes 1275 * @len: Length in bytes 1276 * 1277 * Called with table_lock held. 1278 */ 1279 static int coroutine_fn qed_aio_write_data(void *opaque, int ret, 1280 uint64_t offset, size_t len) 1281 { 1282 QEDAIOCB *acb = opaque; 1283 1284 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); 1285 1286 acb->find_cluster_ret = ret; 1287 1288 switch (ret) { 1289 case QED_CLUSTER_FOUND: 1290 return qed_aio_write_inplace(acb, offset, len); 1291 1292 case QED_CLUSTER_L2: 1293 case QED_CLUSTER_L1: 1294 case QED_CLUSTER_ZERO: 1295 return qed_aio_write_alloc(acb, len); 1296 1297 default: 1298 g_assert_not_reached(); 1299 } 1300 } 1301 1302 /** 1303 * Read data cluster 1304 * 1305 * @opaque: Read request 1306 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1307 * @offset: Cluster offset in bytes 1308 * @len: Length in bytes 1309 * 1310 * Called with table_lock held. 1311 */ 1312 static int coroutine_fn qed_aio_read_data(void *opaque, int ret, 1313 uint64_t offset, size_t len) 1314 { 1315 QEDAIOCB *acb = opaque; 1316 BDRVQEDState *s = acb_to_s(acb); 1317 BlockDriverState *bs = acb->bs; 1318 int r; 1319 1320 qemu_co_mutex_unlock(&s->table_lock); 1321 1322 /* Adjust offset into cluster */ 1323 offset += qed_offset_into_cluster(s, acb->cur_pos); 1324 1325 trace_qed_aio_read_data(s, acb, ret, offset, len); 1326 1327 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1328 1329 /* Handle zero cluster and backing file reads, otherwise read 1330 * data cluster directly. 1331 */ 1332 if (ret == QED_CLUSTER_ZERO) { 1333 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size); 1334 r = 0; 1335 } else if (ret != QED_CLUSTER_FOUND) { 1336 r = qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov, 1337 &acb->backing_qiov); 1338 } else { 1339 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 1340 r = bdrv_co_preadv(bs->file, offset, acb->cur_qiov.size, 1341 &acb->cur_qiov, 0); 1342 } 1343 1344 qemu_co_mutex_lock(&s->table_lock); 1345 return r; 1346 } 1347 1348 /** 1349 * Begin next I/O or complete the request 1350 */ 1351 static int coroutine_fn qed_aio_next_io(QEDAIOCB *acb) 1352 { 1353 BDRVQEDState *s = acb_to_s(acb); 1354 uint64_t offset; 1355 size_t len; 1356 int ret; 1357 1358 qemu_co_mutex_lock(&s->table_lock); 1359 while (1) { 1360 trace_qed_aio_next_io(s, acb, 0, acb->cur_pos + acb->cur_qiov.size); 1361 1362 if (acb->backing_qiov) { 1363 qemu_iovec_destroy(acb->backing_qiov); 1364 g_free(acb->backing_qiov); 1365 acb->backing_qiov = NULL; 1366 } 1367 1368 acb->qiov_offset += acb->cur_qiov.size; 1369 acb->cur_pos += acb->cur_qiov.size; 1370 qemu_iovec_reset(&acb->cur_qiov); 1371 1372 /* Complete request */ 1373 if (acb->cur_pos >= acb->end_pos) { 1374 ret = 0; 1375 break; 1376 } 1377 1378 /* Find next cluster and start I/O */ 1379 len = acb->end_pos - acb->cur_pos; 1380 ret = qed_find_cluster(s, &acb->request, acb->cur_pos, &len, &offset); 1381 if (ret < 0) { 1382 break; 1383 } 1384 1385 if (acb->flags & QED_AIOCB_WRITE) { 1386 ret = qed_aio_write_data(acb, ret, offset, len); 1387 } else { 1388 ret = qed_aio_read_data(acb, ret, offset, len); 1389 } 1390 1391 if (ret < 0 && ret != -EAGAIN) { 1392 break; 1393 } 1394 } 1395 1396 trace_qed_aio_complete(s, acb, ret); 1397 qed_aio_complete(acb); 1398 qemu_co_mutex_unlock(&s->table_lock); 1399 return ret; 1400 } 1401 1402 static int coroutine_fn qed_co_request(BlockDriverState *bs, int64_t sector_num, 1403 QEMUIOVector *qiov, int nb_sectors, 1404 int flags) 1405 { 1406 QEDAIOCB acb = { 1407 .bs = bs, 1408 .cur_pos = (uint64_t) sector_num * BDRV_SECTOR_SIZE, 1409 .end_pos = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE, 1410 .qiov = qiov, 1411 .flags = flags, 1412 }; 1413 qemu_iovec_init(&acb.cur_qiov, qiov->niov); 1414 1415 trace_qed_aio_setup(bs->opaque, &acb, sector_num, nb_sectors, NULL, flags); 1416 1417 /* Start request */ 1418 return qed_aio_next_io(&acb); 1419 } 1420 1421 static int coroutine_fn bdrv_qed_co_readv(BlockDriverState *bs, 1422 int64_t sector_num, int nb_sectors, 1423 QEMUIOVector *qiov) 1424 { 1425 return qed_co_request(bs, sector_num, qiov, nb_sectors, 0); 1426 } 1427 1428 static int coroutine_fn bdrv_qed_co_writev(BlockDriverState *bs, 1429 int64_t sector_num, int nb_sectors, 1430 QEMUIOVector *qiov, int flags) 1431 { 1432 assert(!flags); 1433 return qed_co_request(bs, sector_num, qiov, nb_sectors, QED_AIOCB_WRITE); 1434 } 1435 1436 static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs, 1437 int64_t offset, 1438 int bytes, 1439 BdrvRequestFlags flags) 1440 { 1441 BDRVQEDState *s = bs->opaque; 1442 1443 /* 1444 * Zero writes start without an I/O buffer. If a buffer becomes necessary 1445 * then it will be allocated during request processing. 1446 */ 1447 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes); 1448 1449 /* Fall back if the request is not aligned */ 1450 if (qed_offset_into_cluster(s, offset) || 1451 qed_offset_into_cluster(s, bytes)) { 1452 return -ENOTSUP; 1453 } 1454 1455 return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov, 1456 bytes >> BDRV_SECTOR_BITS, 1457 QED_AIOCB_WRITE | QED_AIOCB_ZERO); 1458 } 1459 1460 static int coroutine_fn bdrv_qed_co_truncate(BlockDriverState *bs, 1461 int64_t offset, 1462 PreallocMode prealloc, 1463 Error **errp) 1464 { 1465 BDRVQEDState *s = bs->opaque; 1466 uint64_t old_image_size; 1467 int ret; 1468 1469 if (prealloc != PREALLOC_MODE_OFF) { 1470 error_setg(errp, "Unsupported preallocation mode '%s'", 1471 PreallocMode_str(prealloc)); 1472 return -ENOTSUP; 1473 } 1474 1475 if (!qed_is_image_size_valid(offset, s->header.cluster_size, 1476 s->header.table_size)) { 1477 error_setg(errp, "Invalid image size specified"); 1478 return -EINVAL; 1479 } 1480 1481 if ((uint64_t)offset < s->header.image_size) { 1482 error_setg(errp, "Shrinking images is currently not supported"); 1483 return -ENOTSUP; 1484 } 1485 1486 old_image_size = s->header.image_size; 1487 s->header.image_size = offset; 1488 ret = qed_write_header_sync(s); 1489 if (ret < 0) { 1490 s->header.image_size = old_image_size; 1491 error_setg_errno(errp, -ret, "Failed to update the image size"); 1492 } 1493 return ret; 1494 } 1495 1496 static int64_t bdrv_qed_getlength(BlockDriverState *bs) 1497 { 1498 BDRVQEDState *s = bs->opaque; 1499 return s->header.image_size; 1500 } 1501 1502 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1503 { 1504 BDRVQEDState *s = bs->opaque; 1505 1506 memset(bdi, 0, sizeof(*bdi)); 1507 bdi->cluster_size = s->header.cluster_size; 1508 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK; 1509 bdi->unallocated_blocks_are_zero = true; 1510 return 0; 1511 } 1512 1513 static int bdrv_qed_change_backing_file(BlockDriverState *bs, 1514 const char *backing_file, 1515 const char *backing_fmt) 1516 { 1517 BDRVQEDState *s = bs->opaque; 1518 QEDHeader new_header, le_header; 1519 void *buffer; 1520 size_t buffer_len, backing_file_len; 1521 int ret; 1522 1523 /* Refuse to set backing filename if unknown compat feature bits are 1524 * active. If the image uses an unknown compat feature then we may not 1525 * know the layout of data following the header structure and cannot safely 1526 * add a new string. 1527 */ 1528 if (backing_file && (s->header.compat_features & 1529 ~QED_COMPAT_FEATURE_MASK)) { 1530 return -ENOTSUP; 1531 } 1532 1533 memcpy(&new_header, &s->header, sizeof(new_header)); 1534 1535 new_header.features &= ~(QED_F_BACKING_FILE | 1536 QED_F_BACKING_FORMAT_NO_PROBE); 1537 1538 /* Adjust feature flags */ 1539 if (backing_file) { 1540 new_header.features |= QED_F_BACKING_FILE; 1541 1542 if (qed_fmt_is_raw(backing_fmt)) { 1543 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 1544 } 1545 } 1546 1547 /* Calculate new header size */ 1548 backing_file_len = 0; 1549 1550 if (backing_file) { 1551 backing_file_len = strlen(backing_file); 1552 } 1553 1554 buffer_len = sizeof(new_header); 1555 new_header.backing_filename_offset = buffer_len; 1556 new_header.backing_filename_size = backing_file_len; 1557 buffer_len += backing_file_len; 1558 1559 /* Make sure we can rewrite header without failing */ 1560 if (buffer_len > new_header.header_size * new_header.cluster_size) { 1561 return -ENOSPC; 1562 } 1563 1564 /* Prepare new header */ 1565 buffer = g_malloc(buffer_len); 1566 1567 qed_header_cpu_to_le(&new_header, &le_header); 1568 memcpy(buffer, &le_header, sizeof(le_header)); 1569 buffer_len = sizeof(le_header); 1570 1571 if (backing_file) { 1572 memcpy(buffer + buffer_len, backing_file, backing_file_len); 1573 buffer_len += backing_file_len; 1574 } 1575 1576 /* Write new header */ 1577 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len); 1578 g_free(buffer); 1579 if (ret == 0) { 1580 memcpy(&s->header, &new_header, sizeof(new_header)); 1581 } 1582 return ret; 1583 } 1584 1585 static void coroutine_fn bdrv_qed_co_invalidate_cache(BlockDriverState *bs, 1586 Error **errp) 1587 { 1588 BDRVQEDState *s = bs->opaque; 1589 Error *local_err = NULL; 1590 int ret; 1591 1592 bdrv_qed_close(bs); 1593 1594 bdrv_qed_init_state(bs); 1595 qemu_co_mutex_lock(&s->table_lock); 1596 ret = bdrv_qed_do_open(bs, NULL, bs->open_flags, &local_err); 1597 qemu_co_mutex_unlock(&s->table_lock); 1598 if (local_err) { 1599 error_propagate_prepend(errp, local_err, 1600 "Could not reopen qed layer: "); 1601 return; 1602 } else if (ret < 0) { 1603 error_setg_errno(errp, -ret, "Could not reopen qed layer"); 1604 return; 1605 } 1606 } 1607 1608 static int coroutine_fn bdrv_qed_co_check(BlockDriverState *bs, 1609 BdrvCheckResult *result, 1610 BdrvCheckMode fix) 1611 { 1612 BDRVQEDState *s = bs->opaque; 1613 int ret; 1614 1615 qemu_co_mutex_lock(&s->table_lock); 1616 ret = qed_check(s, result, !!fix); 1617 qemu_co_mutex_unlock(&s->table_lock); 1618 1619 return ret; 1620 } 1621 1622 static QemuOptsList qed_create_opts = { 1623 .name = "qed-create-opts", 1624 .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head), 1625 .desc = { 1626 { 1627 .name = BLOCK_OPT_SIZE, 1628 .type = QEMU_OPT_SIZE, 1629 .help = "Virtual disk size" 1630 }, 1631 { 1632 .name = BLOCK_OPT_BACKING_FILE, 1633 .type = QEMU_OPT_STRING, 1634 .help = "File name of a base image" 1635 }, 1636 { 1637 .name = BLOCK_OPT_BACKING_FMT, 1638 .type = QEMU_OPT_STRING, 1639 .help = "Image format of the base image" 1640 }, 1641 { 1642 .name = BLOCK_OPT_CLUSTER_SIZE, 1643 .type = QEMU_OPT_SIZE, 1644 .help = "Cluster size (in bytes)", 1645 .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE) 1646 }, 1647 { 1648 .name = BLOCK_OPT_TABLE_SIZE, 1649 .type = QEMU_OPT_SIZE, 1650 .help = "L1/L2 table size (in clusters)" 1651 }, 1652 { /* end of list */ } 1653 } 1654 }; 1655 1656 static BlockDriver bdrv_qed = { 1657 .format_name = "qed", 1658 .instance_size = sizeof(BDRVQEDState), 1659 .create_opts = &qed_create_opts, 1660 .supports_backing = true, 1661 1662 .bdrv_probe = bdrv_qed_probe, 1663 .bdrv_open = bdrv_qed_open, 1664 .bdrv_close = bdrv_qed_close, 1665 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare, 1666 .bdrv_child_perm = bdrv_format_default_perms, 1667 .bdrv_co_create = bdrv_qed_co_create, 1668 .bdrv_co_create_opts = bdrv_qed_co_create_opts, 1669 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1670 .bdrv_co_block_status = bdrv_qed_co_block_status, 1671 .bdrv_co_readv = bdrv_qed_co_readv, 1672 .bdrv_co_writev = bdrv_qed_co_writev, 1673 .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes, 1674 .bdrv_co_truncate = bdrv_qed_co_truncate, 1675 .bdrv_getlength = bdrv_qed_getlength, 1676 .bdrv_get_info = bdrv_qed_get_info, 1677 .bdrv_refresh_limits = bdrv_qed_refresh_limits, 1678 .bdrv_change_backing_file = bdrv_qed_change_backing_file, 1679 .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache, 1680 .bdrv_co_check = bdrv_qed_co_check, 1681 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context, 1682 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context, 1683 .bdrv_co_drain_begin = bdrv_qed_co_drain_begin, 1684 }; 1685 1686 static void bdrv_qed_init(void) 1687 { 1688 bdrv_register(&bdrv_qed); 1689 } 1690 1691 block_init(bdrv_qed_init); 1692