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/main-loop.h" 21 #include "qemu/module.h" 22 #include "qemu/option.h" 23 #include "trace.h" 24 #include "qed.h" 25 #include "sysemu/block-backend.h" 26 #include "qapi/qmp/qdict.h" 27 #include "qapi/qobject-input-visitor.h" 28 #include "qapi/qapi-visit-block-core.h" 29 30 static QemuOptsList qed_create_opts; 31 32 static int bdrv_qed_probe(const uint8_t *buf, int buf_size, 33 const char *filename) 34 { 35 const QEDHeader *header = (const QEDHeader *)buf; 36 37 if (buf_size < sizeof(*header)) { 38 return 0; 39 } 40 if (le32_to_cpu(header->magic) != QED_MAGIC) { 41 return 0; 42 } 43 return 100; 44 } 45 46 /** 47 * Check whether an image format is raw 48 * 49 * @fmt: Backing file format, may be NULL 50 */ 51 static bool qed_fmt_is_raw(const char *fmt) 52 { 53 return fmt && strcmp(fmt, "raw") == 0; 54 } 55 56 static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu) 57 { 58 cpu->magic = le32_to_cpu(le->magic); 59 cpu->cluster_size = le32_to_cpu(le->cluster_size); 60 cpu->table_size = le32_to_cpu(le->table_size); 61 cpu->header_size = le32_to_cpu(le->header_size); 62 cpu->features = le64_to_cpu(le->features); 63 cpu->compat_features = le64_to_cpu(le->compat_features); 64 cpu->autoclear_features = le64_to_cpu(le->autoclear_features); 65 cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset); 66 cpu->image_size = le64_to_cpu(le->image_size); 67 cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset); 68 cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size); 69 } 70 71 static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le) 72 { 73 le->magic = cpu_to_le32(cpu->magic); 74 le->cluster_size = cpu_to_le32(cpu->cluster_size); 75 le->table_size = cpu_to_le32(cpu->table_size); 76 le->header_size = cpu_to_le32(cpu->header_size); 77 le->features = cpu_to_le64(cpu->features); 78 le->compat_features = cpu_to_le64(cpu->compat_features); 79 le->autoclear_features = cpu_to_le64(cpu->autoclear_features); 80 le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset); 81 le->image_size = cpu_to_le64(cpu->image_size); 82 le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset); 83 le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size); 84 } 85 86 int qed_write_header_sync(BDRVQEDState *s) 87 { 88 QEDHeader le; 89 int ret; 90 91 qed_header_cpu_to_le(&s->header, &le); 92 ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le)); 93 if (ret != sizeof(le)) { 94 return ret; 95 } 96 return 0; 97 } 98 99 /** 100 * Update header in-place (does not rewrite backing filename or other strings) 101 * 102 * This function only updates known header fields in-place and does not affect 103 * extra data after the QED header. 104 * 105 * No new allocating reqs can start while this function runs. 106 */ 107 static int coroutine_fn qed_write_header(BDRVQEDState *s) 108 { 109 /* We must write full sectors for O_DIRECT but cannot necessarily generate 110 * the data following the header if an unrecognized compat feature is 111 * active. Therefore, first read the sectors containing the header, update 112 * them, and write back. 113 */ 114 115 int nsectors = DIV_ROUND_UP(sizeof(QEDHeader), BDRV_SECTOR_SIZE); 116 size_t len = nsectors * BDRV_SECTOR_SIZE; 117 uint8_t *buf; 118 int ret; 119 120 assert(s->allocating_acb || s->allocating_write_reqs_plugged); 121 122 buf = qemu_blockalign(s->bs, len); 123 124 ret = bdrv_co_pread(s->bs->file, 0, len, buf, 0); 125 if (ret < 0) { 126 goto out; 127 } 128 129 /* Update header */ 130 qed_header_cpu_to_le(&s->header, (QEDHeader *) buf); 131 132 ret = bdrv_co_pwrite(s->bs->file, 0, len, buf, 0); 133 if (ret < 0) { 134 goto out; 135 } 136 137 ret = 0; 138 out: 139 qemu_vfree(buf); 140 return ret; 141 } 142 143 static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size) 144 { 145 uint64_t table_entries; 146 uint64_t l2_size; 147 148 table_entries = (table_size * cluster_size) / sizeof(uint64_t); 149 l2_size = table_entries * cluster_size; 150 151 return l2_size * table_entries; 152 } 153 154 static bool qed_is_cluster_size_valid(uint32_t cluster_size) 155 { 156 if (cluster_size < QED_MIN_CLUSTER_SIZE || 157 cluster_size > QED_MAX_CLUSTER_SIZE) { 158 return false; 159 } 160 if (cluster_size & (cluster_size - 1)) { 161 return false; /* not power of 2 */ 162 } 163 return true; 164 } 165 166 static bool qed_is_table_size_valid(uint32_t table_size) 167 { 168 if (table_size < QED_MIN_TABLE_SIZE || 169 table_size > QED_MAX_TABLE_SIZE) { 170 return false; 171 } 172 if (table_size & (table_size - 1)) { 173 return false; /* not power of 2 */ 174 } 175 return true; 176 } 177 178 static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size, 179 uint32_t table_size) 180 { 181 if (image_size % BDRV_SECTOR_SIZE != 0) { 182 return false; /* not multiple of sector size */ 183 } 184 if (image_size > qed_max_image_size(cluster_size, table_size)) { 185 return false; /* image is too large */ 186 } 187 return true; 188 } 189 190 /** 191 * Read a string of known length from the image file 192 * 193 * @file: Image file 194 * @offset: File offset to start of string, in bytes 195 * @n: String length in bytes 196 * @buf: Destination buffer 197 * @buflen: Destination buffer length in bytes 198 * @ret: 0 on success, -errno on failure 199 * 200 * The string is NUL-terminated. 201 */ 202 static int qed_read_string(BdrvChild *file, uint64_t offset, size_t n, 203 char *buf, size_t buflen) 204 { 205 int ret; 206 if (n >= buflen) { 207 return -EINVAL; 208 } 209 ret = bdrv_pread(file, offset, buf, n); 210 if (ret < 0) { 211 return ret; 212 } 213 buf[n] = '\0'; 214 return 0; 215 } 216 217 /** 218 * Allocate new clusters 219 * 220 * @s: QED state 221 * @n: Number of contiguous clusters to allocate 222 * @ret: Offset of first allocated cluster 223 * 224 * This function only produces the offset where the new clusters should be 225 * written. It updates BDRVQEDState but does not make any changes to the image 226 * file. 227 * 228 * Called with table_lock held. 229 */ 230 static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n) 231 { 232 uint64_t offset = s->file_size; 233 s->file_size += n * s->header.cluster_size; 234 return offset; 235 } 236 237 QEDTable *qed_alloc_table(BDRVQEDState *s) 238 { 239 /* Honor O_DIRECT memory alignment requirements */ 240 return qemu_blockalign(s->bs, 241 s->header.cluster_size * s->header.table_size); 242 } 243 244 /** 245 * Allocate a new zeroed L2 table 246 * 247 * Called with table_lock held. 248 */ 249 static CachedL2Table *qed_new_l2_table(BDRVQEDState *s) 250 { 251 CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); 252 253 l2_table->table = qed_alloc_table(s); 254 l2_table->offset = qed_alloc_clusters(s, s->header.table_size); 255 256 memset(l2_table->table->offsets, 0, 257 s->header.cluster_size * s->header.table_size); 258 return l2_table; 259 } 260 261 static bool qed_plug_allocating_write_reqs(BDRVQEDState *s) 262 { 263 qemu_co_mutex_lock(&s->table_lock); 264 265 /* No reentrancy is allowed. */ 266 assert(!s->allocating_write_reqs_plugged); 267 if (s->allocating_acb != NULL) { 268 /* Another allocating write came concurrently. This cannot happen 269 * from bdrv_qed_co_drain_begin, but it can happen when the timer runs. 270 */ 271 qemu_co_mutex_unlock(&s->table_lock); 272 return false; 273 } 274 275 s->allocating_write_reqs_plugged = true; 276 qemu_co_mutex_unlock(&s->table_lock); 277 return true; 278 } 279 280 static void qed_unplug_allocating_write_reqs(BDRVQEDState *s) 281 { 282 qemu_co_mutex_lock(&s->table_lock); 283 assert(s->allocating_write_reqs_plugged); 284 s->allocating_write_reqs_plugged = false; 285 qemu_co_queue_next(&s->allocating_write_reqs); 286 qemu_co_mutex_unlock(&s->table_lock); 287 } 288 289 static void coroutine_fn qed_need_check_timer_entry(void *opaque) 290 { 291 BDRVQEDState *s = opaque; 292 int ret; 293 294 trace_qed_need_check_timer_cb(s); 295 296 if (!qed_plug_allocating_write_reqs(s)) { 297 return; 298 } 299 300 /* Ensure writes are on disk before clearing flag */ 301 ret = bdrv_co_flush(s->bs->file->bs); 302 if (ret < 0) { 303 qed_unplug_allocating_write_reqs(s); 304 return; 305 } 306 307 s->header.features &= ~QED_F_NEED_CHECK; 308 ret = qed_write_header(s); 309 (void) ret; 310 311 qed_unplug_allocating_write_reqs(s); 312 313 ret = bdrv_co_flush(s->bs); 314 (void) ret; 315 } 316 317 static void qed_need_check_timer_cb(void *opaque) 318 { 319 Coroutine *co = qemu_coroutine_create(qed_need_check_timer_entry, opaque); 320 qemu_coroutine_enter(co); 321 } 322 323 static void qed_start_need_check_timer(BDRVQEDState *s) 324 { 325 trace_qed_start_need_check_timer(s); 326 327 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for 328 * migration. 329 */ 330 timer_mod(s->need_check_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 331 NANOSECONDS_PER_SECOND * QED_NEED_CHECK_TIMEOUT); 332 } 333 334 /* It's okay to call this multiple times or when no timer is started */ 335 static void qed_cancel_need_check_timer(BDRVQEDState *s) 336 { 337 trace_qed_cancel_need_check_timer(s); 338 timer_del(s->need_check_timer); 339 } 340 341 static void bdrv_qed_detach_aio_context(BlockDriverState *bs) 342 { 343 BDRVQEDState *s = bs->opaque; 344 345 qed_cancel_need_check_timer(s); 346 timer_free(s->need_check_timer); 347 } 348 349 static void bdrv_qed_attach_aio_context(BlockDriverState *bs, 350 AioContext *new_context) 351 { 352 BDRVQEDState *s = bs->opaque; 353 354 s->need_check_timer = aio_timer_new(new_context, 355 QEMU_CLOCK_VIRTUAL, SCALE_NS, 356 qed_need_check_timer_cb, s); 357 if (s->header.features & QED_F_NEED_CHECK) { 358 qed_start_need_check_timer(s); 359 } 360 } 361 362 static void coroutine_fn bdrv_qed_co_drain_begin(BlockDriverState *bs) 363 { 364 BDRVQEDState *s = bs->opaque; 365 366 /* Fire the timer immediately in order to start doing I/O as soon as the 367 * header is flushed. 368 */ 369 if (s->need_check_timer && timer_pending(s->need_check_timer)) { 370 qed_cancel_need_check_timer(s); 371 qed_need_check_timer_entry(s); 372 } 373 } 374 375 static void bdrv_qed_init_state(BlockDriverState *bs) 376 { 377 BDRVQEDState *s = bs->opaque; 378 379 memset(s, 0, sizeof(BDRVQEDState)); 380 s->bs = bs; 381 qemu_co_mutex_init(&s->table_lock); 382 qemu_co_queue_init(&s->allocating_write_reqs); 383 } 384 385 /* Called with table_lock held. */ 386 static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options, 387 int flags, Error **errp) 388 { 389 BDRVQEDState *s = bs->opaque; 390 QEDHeader le_header; 391 int64_t file_size; 392 int ret; 393 394 ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header)); 395 if (ret < 0) { 396 return ret; 397 } 398 qed_header_le_to_cpu(&le_header, &s->header); 399 400 if (s->header.magic != QED_MAGIC) { 401 error_setg(errp, "Image not in QED format"); 402 return -EINVAL; 403 } 404 if (s->header.features & ~QED_FEATURE_MASK) { 405 /* image uses unsupported feature bits */ 406 error_setg(errp, "Unsupported QED features: %" PRIx64, 407 s->header.features & ~QED_FEATURE_MASK); 408 return -ENOTSUP; 409 } 410 if (!qed_is_cluster_size_valid(s->header.cluster_size)) { 411 return -EINVAL; 412 } 413 414 /* Round down file size to the last cluster */ 415 file_size = bdrv_getlength(bs->file->bs); 416 if (file_size < 0) { 417 return file_size; 418 } 419 s->file_size = qed_start_of_cluster(s, file_size); 420 421 if (!qed_is_table_size_valid(s->header.table_size)) { 422 return -EINVAL; 423 } 424 if (!qed_is_image_size_valid(s->header.image_size, 425 s->header.cluster_size, 426 s->header.table_size)) { 427 return -EINVAL; 428 } 429 if (!qed_check_table_offset(s, s->header.l1_table_offset)) { 430 return -EINVAL; 431 } 432 433 s->table_nelems = (s->header.cluster_size * s->header.table_size) / 434 sizeof(uint64_t); 435 s->l2_shift = ctz32(s->header.cluster_size); 436 s->l2_mask = s->table_nelems - 1; 437 s->l1_shift = s->l2_shift + ctz32(s->table_nelems); 438 439 /* Header size calculation must not overflow uint32_t */ 440 if (s->header.header_size > UINT32_MAX / s->header.cluster_size) { 441 return -EINVAL; 442 } 443 444 if ((s->header.features & QED_F_BACKING_FILE)) { 445 if ((uint64_t)s->header.backing_filename_offset + 446 s->header.backing_filename_size > 447 s->header.cluster_size * s->header.header_size) { 448 return -EINVAL; 449 } 450 451 ret = qed_read_string(bs->file, s->header.backing_filename_offset, 452 s->header.backing_filename_size, 453 bs->auto_backing_file, 454 sizeof(bs->auto_backing_file)); 455 if (ret < 0) { 456 return ret; 457 } 458 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 459 bs->auto_backing_file); 460 461 if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) { 462 pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw"); 463 } 464 } 465 466 /* Reset unknown autoclear feature bits. This is a backwards 467 * compatibility mechanism that allows images to be opened by older 468 * programs, which "knock out" unknown feature bits. When an image is 469 * opened by a newer program again it can detect that the autoclear 470 * feature is no longer valid. 471 */ 472 if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 && 473 !bdrv_is_read_only(bs->file->bs) && !(flags & BDRV_O_INACTIVE)) { 474 s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK; 475 476 ret = qed_write_header_sync(s); 477 if (ret) { 478 return ret; 479 } 480 481 /* From here on only known autoclear feature bits are valid */ 482 bdrv_flush(bs->file->bs); 483 } 484 485 s->l1_table = qed_alloc_table(s); 486 qed_init_l2_cache(&s->l2_cache); 487 488 ret = qed_read_l1_table_sync(s); 489 if (ret) { 490 goto out; 491 } 492 493 /* If image was not closed cleanly, check consistency */ 494 if (!(flags & BDRV_O_CHECK) && (s->header.features & QED_F_NEED_CHECK)) { 495 /* Read-only images cannot be fixed. There is no risk of corruption 496 * since write operations are not possible. Therefore, allow 497 * potentially inconsistent images to be opened read-only. This can 498 * aid data recovery from an otherwise inconsistent image. 499 */ 500 if (!bdrv_is_read_only(bs->file->bs) && 501 !(flags & BDRV_O_INACTIVE)) { 502 BdrvCheckResult result = {0}; 503 504 ret = qed_check(s, &result, true); 505 if (ret) { 506 goto out; 507 } 508 } 509 } 510 511 bdrv_qed_attach_aio_context(bs, bdrv_get_aio_context(bs)); 512 513 out: 514 if (ret) { 515 qed_free_l2_cache(&s->l2_cache); 516 qemu_vfree(s->l1_table); 517 } 518 return ret; 519 } 520 521 typedef struct QEDOpenCo { 522 BlockDriverState *bs; 523 QDict *options; 524 int flags; 525 Error **errp; 526 int ret; 527 } QEDOpenCo; 528 529 static void coroutine_fn bdrv_qed_open_entry(void *opaque) 530 { 531 QEDOpenCo *qoc = opaque; 532 BDRVQEDState *s = qoc->bs->opaque; 533 534 qemu_co_mutex_lock(&s->table_lock); 535 qoc->ret = bdrv_qed_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp); 536 qemu_co_mutex_unlock(&s->table_lock); 537 } 538 539 static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags, 540 Error **errp) 541 { 542 QEDOpenCo qoc = { 543 .bs = bs, 544 .options = options, 545 .flags = flags, 546 .errp = errp, 547 .ret = -EINPROGRESS 548 }; 549 550 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, 551 false, errp); 552 if (!bs->file) { 553 return -EINVAL; 554 } 555 556 bdrv_qed_init_state(bs); 557 if (qemu_in_coroutine()) { 558 bdrv_qed_open_entry(&qoc); 559 } else { 560 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 561 qemu_coroutine_enter(qemu_coroutine_create(bdrv_qed_open_entry, &qoc)); 562 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); 563 } 564 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); 565 return qoc.ret; 566 } 567 568 static void bdrv_qed_refresh_limits(BlockDriverState *bs, Error **errp) 569 { 570 BDRVQEDState *s = bs->opaque; 571 572 bs->bl.pwrite_zeroes_alignment = s->header.cluster_size; 573 } 574 575 /* We have nothing to do for QED reopen, stubs just return 576 * success */ 577 static int bdrv_qed_reopen_prepare(BDRVReopenState *state, 578 BlockReopenQueue *queue, Error **errp) 579 { 580 return 0; 581 } 582 583 static void bdrv_qed_close(BlockDriverState *bs) 584 { 585 BDRVQEDState *s = bs->opaque; 586 587 bdrv_qed_detach_aio_context(bs); 588 589 /* Ensure writes reach stable storage */ 590 bdrv_flush(bs->file->bs); 591 592 /* Clean shutdown, no check required on next open */ 593 if (s->header.features & QED_F_NEED_CHECK) { 594 s->header.features &= ~QED_F_NEED_CHECK; 595 qed_write_header_sync(s); 596 } 597 598 qed_free_l2_cache(&s->l2_cache); 599 qemu_vfree(s->l1_table); 600 } 601 602 static int coroutine_fn bdrv_qed_co_create(BlockdevCreateOptions *opts, 603 Error **errp) 604 { 605 BlockdevCreateOptionsQed *qed_opts; 606 BlockBackend *blk = NULL; 607 BlockDriverState *bs = NULL; 608 609 QEDHeader header; 610 QEDHeader le_header; 611 uint8_t *l1_table = NULL; 612 size_t l1_size; 613 int ret = 0; 614 615 assert(opts->driver == BLOCKDEV_DRIVER_QED); 616 qed_opts = &opts->u.qed; 617 618 /* Validate options and set default values */ 619 if (!qed_opts->has_cluster_size) { 620 qed_opts->cluster_size = QED_DEFAULT_CLUSTER_SIZE; 621 } 622 if (!qed_opts->has_table_size) { 623 qed_opts->table_size = QED_DEFAULT_TABLE_SIZE; 624 } 625 626 if (!qed_is_cluster_size_valid(qed_opts->cluster_size)) { 627 error_setg(errp, "QED cluster size must be within range [%u, %u] " 628 "and power of 2", 629 QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE); 630 return -EINVAL; 631 } 632 if (!qed_is_table_size_valid(qed_opts->table_size)) { 633 error_setg(errp, "QED table size must be within range [%u, %u] " 634 "and power of 2", 635 QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE); 636 return -EINVAL; 637 } 638 if (!qed_is_image_size_valid(qed_opts->size, qed_opts->cluster_size, 639 qed_opts->table_size)) 640 { 641 error_setg(errp, "QED image size must be a non-zero multiple of " 642 "cluster size and less than %" PRIu64 " bytes", 643 qed_max_image_size(qed_opts->cluster_size, 644 qed_opts->table_size)); 645 return -EINVAL; 646 } 647 648 /* Create BlockBackend to write to the image */ 649 bs = bdrv_open_blockdev_ref(qed_opts->file, errp); 650 if (bs == NULL) { 651 return -EIO; 652 } 653 654 blk = blk_new(bdrv_get_aio_context(bs), 655 BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL); 656 ret = blk_insert_bs(blk, bs, errp); 657 if (ret < 0) { 658 goto out; 659 } 660 blk_set_allow_write_beyond_eof(blk, true); 661 662 /* Prepare image format */ 663 header = (QEDHeader) { 664 .magic = QED_MAGIC, 665 .cluster_size = qed_opts->cluster_size, 666 .table_size = qed_opts->table_size, 667 .header_size = 1, 668 .features = 0, 669 .compat_features = 0, 670 .l1_table_offset = qed_opts->cluster_size, 671 .image_size = qed_opts->size, 672 }; 673 674 l1_size = header.cluster_size * header.table_size; 675 676 /* File must start empty and grow, check truncate is supported */ 677 ret = blk_truncate(blk, 0, PREALLOC_MODE_OFF, errp); 678 if (ret < 0) { 679 goto out; 680 } 681 682 if (qed_opts->has_backing_file) { 683 header.features |= QED_F_BACKING_FILE; 684 header.backing_filename_offset = sizeof(le_header); 685 header.backing_filename_size = strlen(qed_opts->backing_file); 686 687 if (qed_opts->has_backing_fmt) { 688 const char *backing_fmt = BlockdevDriver_str(qed_opts->backing_fmt); 689 if (qed_fmt_is_raw(backing_fmt)) { 690 header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 691 } 692 } 693 } 694 695 qed_header_cpu_to_le(&header, &le_header); 696 ret = blk_pwrite(blk, 0, &le_header, sizeof(le_header), 0); 697 if (ret < 0) { 698 goto out; 699 } 700 ret = blk_pwrite(blk, sizeof(le_header), qed_opts->backing_file, 701 header.backing_filename_size, 0); 702 if (ret < 0) { 703 goto out; 704 } 705 706 l1_table = g_malloc0(l1_size); 707 ret = blk_pwrite(blk, header.l1_table_offset, l1_table, l1_size, 0); 708 if (ret < 0) { 709 goto out; 710 } 711 712 ret = 0; /* success */ 713 out: 714 g_free(l1_table); 715 blk_unref(blk); 716 bdrv_unref(bs); 717 return ret; 718 } 719 720 static int coroutine_fn bdrv_qed_co_create_opts(const char *filename, 721 QemuOpts *opts, 722 Error **errp) 723 { 724 BlockdevCreateOptions *create_options = NULL; 725 QDict *qdict; 726 Visitor *v; 727 BlockDriverState *bs = NULL; 728 Error *local_err = NULL; 729 int ret; 730 731 static const QDictRenames opt_renames[] = { 732 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 733 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 734 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 735 { BLOCK_OPT_TABLE_SIZE, "table-size" }, 736 { NULL, NULL }, 737 }; 738 739 /* Parse options and convert legacy syntax */ 740 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qed_create_opts, true); 741 742 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 743 ret = -EINVAL; 744 goto fail; 745 } 746 747 /* Create and open the file (protocol layer) */ 748 ret = bdrv_create_file(filename, opts, &local_err); 749 if (ret < 0) { 750 error_propagate(errp, local_err); 751 goto fail; 752 } 753 754 bs = bdrv_open(filename, NULL, NULL, 755 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 756 if (bs == NULL) { 757 ret = -EIO; 758 goto fail; 759 } 760 761 /* Now get the QAPI type BlockdevCreateOptions */ 762 qdict_put_str(qdict, "driver", "qed"); 763 qdict_put_str(qdict, "file", bs->node_name); 764 765 v = qobject_input_visitor_new_flat_confused(qdict, errp); 766 if (!v) { 767 ret = -EINVAL; 768 goto fail; 769 } 770 771 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); 772 visit_free(v); 773 774 if (local_err) { 775 error_propagate(errp, local_err); 776 ret = -EINVAL; 777 goto fail; 778 } 779 780 /* Silently round up size */ 781 assert(create_options->driver == BLOCKDEV_DRIVER_QED); 782 create_options->u.qed.size = 783 ROUND_UP(create_options->u.qed.size, BDRV_SECTOR_SIZE); 784 785 /* Create the qed image (format layer) */ 786 ret = bdrv_qed_co_create(create_options, errp); 787 788 fail: 789 qobject_unref(qdict); 790 bdrv_unref(bs); 791 qapi_free_BlockdevCreateOptions(create_options); 792 return ret; 793 } 794 795 static int coroutine_fn bdrv_qed_co_block_status(BlockDriverState *bs, 796 bool want_zero, 797 int64_t pos, int64_t bytes, 798 int64_t *pnum, int64_t *map, 799 BlockDriverState **file) 800 { 801 BDRVQEDState *s = bs->opaque; 802 size_t len = MIN(bytes, SIZE_MAX); 803 int status; 804 QEDRequest request = { .l2_table = NULL }; 805 uint64_t offset; 806 int ret; 807 808 qemu_co_mutex_lock(&s->table_lock); 809 ret = qed_find_cluster(s, &request, pos, &len, &offset); 810 811 *pnum = len; 812 switch (ret) { 813 case QED_CLUSTER_FOUND: 814 *map = offset | qed_offset_into_cluster(s, pos); 815 status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 816 *file = bs->file->bs; 817 break; 818 case QED_CLUSTER_ZERO: 819 status = BDRV_BLOCK_ZERO; 820 break; 821 case QED_CLUSTER_L2: 822 case QED_CLUSTER_L1: 823 status = 0; 824 break; 825 default: 826 assert(ret < 0); 827 status = ret; 828 break; 829 } 830 831 qed_unref_l2_cache_entry(request.l2_table); 832 qemu_co_mutex_unlock(&s->table_lock); 833 834 return status; 835 } 836 837 static BDRVQEDState *acb_to_s(QEDAIOCB *acb) 838 { 839 return acb->bs->opaque; 840 } 841 842 /** 843 * Read from the backing file or zero-fill if no backing file 844 * 845 * @s: QED state 846 * @pos: Byte position in device 847 * @qiov: Destination I/O vector 848 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here 849 * @cb: Completion function 850 * @opaque: User data for completion function 851 * 852 * This function reads qiov->size bytes starting at pos from the backing file. 853 * If there is no backing file then zeroes are read. 854 */ 855 static int coroutine_fn qed_read_backing_file(BDRVQEDState *s, uint64_t pos, 856 QEMUIOVector *qiov, 857 QEMUIOVector **backing_qiov) 858 { 859 uint64_t backing_length = 0; 860 size_t size; 861 int ret; 862 863 /* If there is a backing file, get its length. Treat the absence of a 864 * backing file like a zero length backing file. 865 */ 866 if (s->bs->backing) { 867 int64_t l = bdrv_getlength(s->bs->backing->bs); 868 if (l < 0) { 869 return l; 870 } 871 backing_length = l; 872 } 873 874 /* Zero all sectors if reading beyond the end of the backing file */ 875 if (pos >= backing_length || 876 pos + qiov->size > backing_length) { 877 qemu_iovec_memset(qiov, 0, 0, qiov->size); 878 } 879 880 /* Complete now if there are no backing file sectors to read */ 881 if (pos >= backing_length) { 882 return 0; 883 } 884 885 /* If the read straddles the end of the backing file, shorten it */ 886 size = MIN((uint64_t)backing_length - pos, qiov->size); 887 888 assert(*backing_qiov == NULL); 889 *backing_qiov = g_new(QEMUIOVector, 1); 890 qemu_iovec_init(*backing_qiov, qiov->niov); 891 qemu_iovec_concat(*backing_qiov, qiov, 0, size); 892 893 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); 894 ret = bdrv_co_preadv(s->bs->backing, pos, size, *backing_qiov, 0); 895 if (ret < 0) { 896 return ret; 897 } 898 return 0; 899 } 900 901 /** 902 * Copy data from backing file into the image 903 * 904 * @s: QED state 905 * @pos: Byte position in device 906 * @len: Number of bytes 907 * @offset: Byte offset in image file 908 */ 909 static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s, 910 uint64_t pos, uint64_t len, 911 uint64_t offset) 912 { 913 QEMUIOVector qiov; 914 QEMUIOVector *backing_qiov = NULL; 915 int ret; 916 917 /* Skip copy entirely if there is no work to do */ 918 if (len == 0) { 919 return 0; 920 } 921 922 qemu_iovec_init_buf(&qiov, qemu_blockalign(s->bs, len), len); 923 924 ret = qed_read_backing_file(s, pos, &qiov, &backing_qiov); 925 926 if (backing_qiov) { 927 qemu_iovec_destroy(backing_qiov); 928 g_free(backing_qiov); 929 backing_qiov = NULL; 930 } 931 932 if (ret) { 933 goto out; 934 } 935 936 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); 937 ret = bdrv_co_pwritev(s->bs->file, offset, qiov.size, &qiov, 0); 938 if (ret < 0) { 939 goto out; 940 } 941 ret = 0; 942 out: 943 qemu_vfree(qemu_iovec_buf(&qiov)); 944 return ret; 945 } 946 947 /** 948 * Link one or more contiguous clusters into a table 949 * 950 * @s: QED state 951 * @table: L2 table 952 * @index: First cluster index 953 * @n: Number of contiguous clusters 954 * @cluster: First cluster offset 955 * 956 * The cluster offset may be an allocated byte offset in the image file, the 957 * zero cluster marker, or the unallocated cluster marker. 958 * 959 * Called with table_lock held. 960 */ 961 static void coroutine_fn qed_update_l2_table(BDRVQEDState *s, QEDTable *table, 962 int index, unsigned int n, 963 uint64_t cluster) 964 { 965 int i; 966 for (i = index; i < index + n; i++) { 967 table->offsets[i] = cluster; 968 if (!qed_offset_is_unalloc_cluster(cluster) && 969 !qed_offset_is_zero_cluster(cluster)) { 970 cluster += s->header.cluster_size; 971 } 972 } 973 } 974 975 /* Called with table_lock held. */ 976 static void coroutine_fn qed_aio_complete(QEDAIOCB *acb) 977 { 978 BDRVQEDState *s = acb_to_s(acb); 979 980 /* Free resources */ 981 qemu_iovec_destroy(&acb->cur_qiov); 982 qed_unref_l2_cache_entry(acb->request.l2_table); 983 984 /* Free the buffer we may have allocated for zero writes */ 985 if (acb->flags & QED_AIOCB_ZERO) { 986 qemu_vfree(acb->qiov->iov[0].iov_base); 987 acb->qiov->iov[0].iov_base = NULL; 988 } 989 990 /* Start next allocating write request waiting behind this one. Note that 991 * requests enqueue themselves when they first hit an unallocated cluster 992 * but they wait until the entire request is finished before waking up the 993 * next request in the queue. This ensures that we don't cycle through 994 * requests multiple times but rather finish one at a time completely. 995 */ 996 if (acb == s->allocating_acb) { 997 s->allocating_acb = NULL; 998 if (!qemu_co_queue_empty(&s->allocating_write_reqs)) { 999 qemu_co_queue_next(&s->allocating_write_reqs); 1000 } else if (s->header.features & QED_F_NEED_CHECK) { 1001 qed_start_need_check_timer(s); 1002 } 1003 } 1004 } 1005 1006 /** 1007 * Update L1 table with new L2 table offset and write it out 1008 * 1009 * Called with table_lock held. 1010 */ 1011 static int coroutine_fn qed_aio_write_l1_update(QEDAIOCB *acb) 1012 { 1013 BDRVQEDState *s = acb_to_s(acb); 1014 CachedL2Table *l2_table = acb->request.l2_table; 1015 uint64_t l2_offset = l2_table->offset; 1016 int index, ret; 1017 1018 index = qed_l1_index(s, acb->cur_pos); 1019 s->l1_table->offsets[index] = l2_table->offset; 1020 1021 ret = qed_write_l1_table(s, index, 1); 1022 1023 /* Commit the current L2 table to the cache */ 1024 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 1025 1026 /* This is guaranteed to succeed because we just committed the entry to the 1027 * cache. 1028 */ 1029 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 1030 assert(acb->request.l2_table != NULL); 1031 1032 return ret; 1033 } 1034 1035 1036 /** 1037 * Update L2 table with new cluster offsets and write them out 1038 * 1039 * Called with table_lock held. 1040 */ 1041 static int coroutine_fn qed_aio_write_l2_update(QEDAIOCB *acb, uint64_t offset) 1042 { 1043 BDRVQEDState *s = acb_to_s(acb); 1044 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1; 1045 int index, ret; 1046 1047 if (need_alloc) { 1048 qed_unref_l2_cache_entry(acb->request.l2_table); 1049 acb->request.l2_table = qed_new_l2_table(s); 1050 } 1051 1052 index = qed_l2_index(s, acb->cur_pos); 1053 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, 1054 offset); 1055 1056 if (need_alloc) { 1057 /* Write out the whole new L2 table */ 1058 ret = qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true); 1059 if (ret) { 1060 return ret; 1061 } 1062 return qed_aio_write_l1_update(acb); 1063 } else { 1064 /* Write out only the updated part of the L2 table */ 1065 ret = qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, 1066 false); 1067 if (ret) { 1068 return ret; 1069 } 1070 } 1071 return 0; 1072 } 1073 1074 /** 1075 * Write data to the image file 1076 * 1077 * Called with table_lock *not* held. 1078 */ 1079 static int coroutine_fn qed_aio_write_main(QEDAIOCB *acb) 1080 { 1081 BDRVQEDState *s = acb_to_s(acb); 1082 uint64_t offset = acb->cur_cluster + 1083 qed_offset_into_cluster(s, acb->cur_pos); 1084 1085 trace_qed_aio_write_main(s, acb, 0, offset, acb->cur_qiov.size); 1086 1087 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); 1088 return bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size, 1089 &acb->cur_qiov, 0); 1090 } 1091 1092 /** 1093 * Populate untouched regions of new data cluster 1094 * 1095 * Called with table_lock held. 1096 */ 1097 static int coroutine_fn qed_aio_write_cow(QEDAIOCB *acb) 1098 { 1099 BDRVQEDState *s = acb_to_s(acb); 1100 uint64_t start, len, offset; 1101 int ret; 1102 1103 qemu_co_mutex_unlock(&s->table_lock); 1104 1105 /* Populate front untouched region of new data cluster */ 1106 start = qed_start_of_cluster(s, acb->cur_pos); 1107 len = qed_offset_into_cluster(s, acb->cur_pos); 1108 1109 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); 1110 ret = qed_copy_from_backing_file(s, start, len, acb->cur_cluster); 1111 if (ret < 0) { 1112 goto out; 1113 } 1114 1115 /* Populate back untouched region of new data cluster */ 1116 start = acb->cur_pos + acb->cur_qiov.size; 1117 len = qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start; 1118 offset = acb->cur_cluster + 1119 qed_offset_into_cluster(s, acb->cur_pos) + 1120 acb->cur_qiov.size; 1121 1122 trace_qed_aio_write_postfill(s, acb, start, len, offset); 1123 ret = qed_copy_from_backing_file(s, start, len, offset); 1124 if (ret < 0) { 1125 goto out; 1126 } 1127 1128 ret = qed_aio_write_main(acb); 1129 if (ret < 0) { 1130 goto out; 1131 } 1132 1133 if (s->bs->backing) { 1134 /* 1135 * Flush new data clusters before updating the L2 table 1136 * 1137 * This flush is necessary when a backing file is in use. A crash 1138 * during an allocating write could result in empty clusters in the 1139 * image. If the write only touched a subregion of the cluster, 1140 * then backing image sectors have been lost in the untouched 1141 * region. The solution is to flush after writing a new data 1142 * cluster and before updating the L2 table. 1143 */ 1144 ret = bdrv_co_flush(s->bs->file->bs); 1145 } 1146 1147 out: 1148 qemu_co_mutex_lock(&s->table_lock); 1149 return ret; 1150 } 1151 1152 /** 1153 * Check if the QED_F_NEED_CHECK bit should be set during allocating write 1154 */ 1155 static bool qed_should_set_need_check(BDRVQEDState *s) 1156 { 1157 /* The flush before L2 update path ensures consistency */ 1158 if (s->bs->backing) { 1159 return false; 1160 } 1161 1162 return !(s->header.features & QED_F_NEED_CHECK); 1163 } 1164 1165 /** 1166 * Write new data cluster 1167 * 1168 * @acb: Write request 1169 * @len: Length in bytes 1170 * 1171 * This path is taken when writing to previously unallocated clusters. 1172 * 1173 * Called with table_lock held. 1174 */ 1175 static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 1176 { 1177 BDRVQEDState *s = acb_to_s(acb); 1178 int ret; 1179 1180 /* Cancel timer when the first allocating request comes in */ 1181 if (s->allocating_acb == NULL) { 1182 qed_cancel_need_check_timer(s); 1183 } 1184 1185 /* Freeze this request if another allocating write is in progress */ 1186 if (s->allocating_acb != acb || s->allocating_write_reqs_plugged) { 1187 if (s->allocating_acb != NULL) { 1188 qemu_co_queue_wait(&s->allocating_write_reqs, &s->table_lock); 1189 assert(s->allocating_acb == NULL); 1190 } 1191 s->allocating_acb = acb; 1192 return -EAGAIN; /* start over with looking up table entries */ 1193 } 1194 1195 acb->cur_nclusters = qed_bytes_to_clusters(s, 1196 qed_offset_into_cluster(s, acb->cur_pos) + len); 1197 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1198 1199 if (acb->flags & QED_AIOCB_ZERO) { 1200 /* Skip ahead if the clusters are already zero */ 1201 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) { 1202 return 0; 1203 } 1204 acb->cur_cluster = 1; 1205 } else { 1206 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); 1207 } 1208 1209 if (qed_should_set_need_check(s)) { 1210 s->header.features |= QED_F_NEED_CHECK; 1211 ret = qed_write_header(s); 1212 if (ret < 0) { 1213 return ret; 1214 } 1215 } 1216 1217 if (!(acb->flags & QED_AIOCB_ZERO)) { 1218 ret = qed_aio_write_cow(acb); 1219 if (ret < 0) { 1220 return ret; 1221 } 1222 } 1223 1224 return qed_aio_write_l2_update(acb, acb->cur_cluster); 1225 } 1226 1227 /** 1228 * Write data cluster in place 1229 * 1230 * @acb: Write request 1231 * @offset: Cluster offset in bytes 1232 * @len: Length in bytes 1233 * 1234 * This path is taken when writing to already allocated clusters. 1235 * 1236 * Called with table_lock held. 1237 */ 1238 static int coroutine_fn qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, 1239 size_t len) 1240 { 1241 BDRVQEDState *s = acb_to_s(acb); 1242 int r; 1243 1244 qemu_co_mutex_unlock(&s->table_lock); 1245 1246 /* Allocate buffer for zero writes */ 1247 if (acb->flags & QED_AIOCB_ZERO) { 1248 struct iovec *iov = acb->qiov->iov; 1249 1250 if (!iov->iov_base) { 1251 iov->iov_base = qemu_try_blockalign(acb->bs, iov->iov_len); 1252 if (iov->iov_base == NULL) { 1253 r = -ENOMEM; 1254 goto out; 1255 } 1256 memset(iov->iov_base, 0, iov->iov_len); 1257 } 1258 } 1259 1260 /* Calculate the I/O vector */ 1261 acb->cur_cluster = offset; 1262 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1263 1264 /* Do the actual write. */ 1265 r = qed_aio_write_main(acb); 1266 out: 1267 qemu_co_mutex_lock(&s->table_lock); 1268 return r; 1269 } 1270 1271 /** 1272 * Write data cluster 1273 * 1274 * @opaque: Write request 1275 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1276 * @offset: Cluster offset in bytes 1277 * @len: Length in bytes 1278 * 1279 * Called with table_lock held. 1280 */ 1281 static int coroutine_fn qed_aio_write_data(void *opaque, int ret, 1282 uint64_t offset, size_t len) 1283 { 1284 QEDAIOCB *acb = opaque; 1285 1286 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); 1287 1288 acb->find_cluster_ret = ret; 1289 1290 switch (ret) { 1291 case QED_CLUSTER_FOUND: 1292 return qed_aio_write_inplace(acb, offset, len); 1293 1294 case QED_CLUSTER_L2: 1295 case QED_CLUSTER_L1: 1296 case QED_CLUSTER_ZERO: 1297 return qed_aio_write_alloc(acb, len); 1298 1299 default: 1300 g_assert_not_reached(); 1301 } 1302 } 1303 1304 /** 1305 * Read data cluster 1306 * 1307 * @opaque: Read request 1308 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1309 * @offset: Cluster offset in bytes 1310 * @len: Length in bytes 1311 * 1312 * Called with table_lock held. 1313 */ 1314 static int coroutine_fn qed_aio_read_data(void *opaque, int ret, 1315 uint64_t offset, size_t len) 1316 { 1317 QEDAIOCB *acb = opaque; 1318 BDRVQEDState *s = acb_to_s(acb); 1319 BlockDriverState *bs = acb->bs; 1320 int r; 1321 1322 qemu_co_mutex_unlock(&s->table_lock); 1323 1324 /* Adjust offset into cluster */ 1325 offset += qed_offset_into_cluster(s, acb->cur_pos); 1326 1327 trace_qed_aio_read_data(s, acb, ret, offset, len); 1328 1329 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1330 1331 /* Handle zero cluster and backing file reads, otherwise read 1332 * data cluster directly. 1333 */ 1334 if (ret == QED_CLUSTER_ZERO) { 1335 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size); 1336 r = 0; 1337 } else if (ret != QED_CLUSTER_FOUND) { 1338 r = qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov, 1339 &acb->backing_qiov); 1340 } else { 1341 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 1342 r = bdrv_co_preadv(bs->file, offset, acb->cur_qiov.size, 1343 &acb->cur_qiov, 0); 1344 } 1345 1346 qemu_co_mutex_lock(&s->table_lock); 1347 return r; 1348 } 1349 1350 /** 1351 * Begin next I/O or complete the request 1352 */ 1353 static int coroutine_fn qed_aio_next_io(QEDAIOCB *acb) 1354 { 1355 BDRVQEDState *s = acb_to_s(acb); 1356 uint64_t offset; 1357 size_t len; 1358 int ret; 1359 1360 qemu_co_mutex_lock(&s->table_lock); 1361 while (1) { 1362 trace_qed_aio_next_io(s, acb, 0, acb->cur_pos + acb->cur_qiov.size); 1363 1364 if (acb->backing_qiov) { 1365 qemu_iovec_destroy(acb->backing_qiov); 1366 g_free(acb->backing_qiov); 1367 acb->backing_qiov = NULL; 1368 } 1369 1370 acb->qiov_offset += acb->cur_qiov.size; 1371 acb->cur_pos += acb->cur_qiov.size; 1372 qemu_iovec_reset(&acb->cur_qiov); 1373 1374 /* Complete request */ 1375 if (acb->cur_pos >= acb->end_pos) { 1376 ret = 0; 1377 break; 1378 } 1379 1380 /* Find next cluster and start I/O */ 1381 len = acb->end_pos - acb->cur_pos; 1382 ret = qed_find_cluster(s, &acb->request, acb->cur_pos, &len, &offset); 1383 if (ret < 0) { 1384 break; 1385 } 1386 1387 if (acb->flags & QED_AIOCB_WRITE) { 1388 ret = qed_aio_write_data(acb, ret, offset, len); 1389 } else { 1390 ret = qed_aio_read_data(acb, ret, offset, len); 1391 } 1392 1393 if (ret < 0 && ret != -EAGAIN) { 1394 break; 1395 } 1396 } 1397 1398 trace_qed_aio_complete(s, acb, ret); 1399 qed_aio_complete(acb); 1400 qemu_co_mutex_unlock(&s->table_lock); 1401 return ret; 1402 } 1403 1404 static int coroutine_fn qed_co_request(BlockDriverState *bs, int64_t sector_num, 1405 QEMUIOVector *qiov, int nb_sectors, 1406 int flags) 1407 { 1408 QEDAIOCB acb = { 1409 .bs = bs, 1410 .cur_pos = (uint64_t) sector_num * BDRV_SECTOR_SIZE, 1411 .end_pos = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE, 1412 .qiov = qiov, 1413 .flags = flags, 1414 }; 1415 qemu_iovec_init(&acb.cur_qiov, qiov->niov); 1416 1417 trace_qed_aio_setup(bs->opaque, &acb, sector_num, nb_sectors, NULL, flags); 1418 1419 /* Start request */ 1420 return qed_aio_next_io(&acb); 1421 } 1422 1423 static int coroutine_fn bdrv_qed_co_readv(BlockDriverState *bs, 1424 int64_t sector_num, int nb_sectors, 1425 QEMUIOVector *qiov) 1426 { 1427 return qed_co_request(bs, sector_num, qiov, nb_sectors, 0); 1428 } 1429 1430 static int coroutine_fn bdrv_qed_co_writev(BlockDriverState *bs, 1431 int64_t sector_num, int nb_sectors, 1432 QEMUIOVector *qiov, int flags) 1433 { 1434 assert(!flags); 1435 return qed_co_request(bs, sector_num, qiov, nb_sectors, QED_AIOCB_WRITE); 1436 } 1437 1438 static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs, 1439 int64_t offset, 1440 int bytes, 1441 BdrvRequestFlags flags) 1442 { 1443 BDRVQEDState *s = bs->opaque; 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 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes); 1450 1451 /* Fall back if the request is not aligned */ 1452 if (qed_offset_into_cluster(s, offset) || 1453 qed_offset_into_cluster(s, bytes)) { 1454 return -ENOTSUP; 1455 } 1456 1457 return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov, 1458 bytes >> BDRV_SECTOR_BITS, 1459 QED_AIOCB_WRITE | QED_AIOCB_ZERO); 1460 } 1461 1462 static int coroutine_fn bdrv_qed_co_truncate(BlockDriverState *bs, 1463 int64_t offset, 1464 PreallocMode prealloc, 1465 Error **errp) 1466 { 1467 BDRVQEDState *s = bs->opaque; 1468 uint64_t old_image_size; 1469 int ret; 1470 1471 if (prealloc != PREALLOC_MODE_OFF) { 1472 error_setg(errp, "Unsupported preallocation mode '%s'", 1473 PreallocMode_str(prealloc)); 1474 return -ENOTSUP; 1475 } 1476 1477 if (!qed_is_image_size_valid(offset, s->header.cluster_size, 1478 s->header.table_size)) { 1479 error_setg(errp, "Invalid image size specified"); 1480 return -EINVAL; 1481 } 1482 1483 if ((uint64_t)offset < s->header.image_size) { 1484 error_setg(errp, "Shrinking images is currently not supported"); 1485 return -ENOTSUP; 1486 } 1487 1488 old_image_size = s->header.image_size; 1489 s->header.image_size = offset; 1490 ret = qed_write_header_sync(s); 1491 if (ret < 0) { 1492 s->header.image_size = old_image_size; 1493 error_setg_errno(errp, -ret, "Failed to update the image size"); 1494 } 1495 return ret; 1496 } 1497 1498 static int64_t bdrv_qed_getlength(BlockDriverState *bs) 1499 { 1500 BDRVQEDState *s = bs->opaque; 1501 return s->header.image_size; 1502 } 1503 1504 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1505 { 1506 BDRVQEDState *s = bs->opaque; 1507 1508 memset(bdi, 0, sizeof(*bdi)); 1509 bdi->cluster_size = s->header.cluster_size; 1510 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK; 1511 bdi->unallocated_blocks_are_zero = true; 1512 return 0; 1513 } 1514 1515 static int bdrv_qed_change_backing_file(BlockDriverState *bs, 1516 const char *backing_file, 1517 const char *backing_fmt) 1518 { 1519 BDRVQEDState *s = bs->opaque; 1520 QEDHeader new_header, le_header; 1521 void *buffer; 1522 size_t buffer_len, backing_file_len; 1523 int ret; 1524 1525 /* Refuse to set backing filename if unknown compat feature bits are 1526 * active. If the image uses an unknown compat feature then we may not 1527 * know the layout of data following the header structure and cannot safely 1528 * add a new string. 1529 */ 1530 if (backing_file && (s->header.compat_features & 1531 ~QED_COMPAT_FEATURE_MASK)) { 1532 return -ENOTSUP; 1533 } 1534 1535 memcpy(&new_header, &s->header, sizeof(new_header)); 1536 1537 new_header.features &= ~(QED_F_BACKING_FILE | 1538 QED_F_BACKING_FORMAT_NO_PROBE); 1539 1540 /* Adjust feature flags */ 1541 if (backing_file) { 1542 new_header.features |= QED_F_BACKING_FILE; 1543 1544 if (qed_fmt_is_raw(backing_fmt)) { 1545 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 1546 } 1547 } 1548 1549 /* Calculate new header size */ 1550 backing_file_len = 0; 1551 1552 if (backing_file) { 1553 backing_file_len = strlen(backing_file); 1554 } 1555 1556 buffer_len = sizeof(new_header); 1557 new_header.backing_filename_offset = buffer_len; 1558 new_header.backing_filename_size = backing_file_len; 1559 buffer_len += backing_file_len; 1560 1561 /* Make sure we can rewrite header without failing */ 1562 if (buffer_len > new_header.header_size * new_header.cluster_size) { 1563 return -ENOSPC; 1564 } 1565 1566 /* Prepare new header */ 1567 buffer = g_malloc(buffer_len); 1568 1569 qed_header_cpu_to_le(&new_header, &le_header); 1570 memcpy(buffer, &le_header, sizeof(le_header)); 1571 buffer_len = sizeof(le_header); 1572 1573 if (backing_file) { 1574 memcpy(buffer + buffer_len, backing_file, backing_file_len); 1575 buffer_len += backing_file_len; 1576 } 1577 1578 /* Write new header */ 1579 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len); 1580 g_free(buffer); 1581 if (ret == 0) { 1582 memcpy(&s->header, &new_header, sizeof(new_header)); 1583 } 1584 return ret; 1585 } 1586 1587 static void coroutine_fn bdrv_qed_co_invalidate_cache(BlockDriverState *bs, 1588 Error **errp) 1589 { 1590 BDRVQEDState *s = bs->opaque; 1591 Error *local_err = NULL; 1592 int ret; 1593 1594 bdrv_qed_close(bs); 1595 1596 bdrv_qed_init_state(bs); 1597 qemu_co_mutex_lock(&s->table_lock); 1598 ret = bdrv_qed_do_open(bs, NULL, bs->open_flags, &local_err); 1599 qemu_co_mutex_unlock(&s->table_lock); 1600 if (local_err) { 1601 error_propagate_prepend(errp, local_err, 1602 "Could not reopen qed layer: "); 1603 return; 1604 } else if (ret < 0) { 1605 error_setg_errno(errp, -ret, "Could not reopen qed layer"); 1606 return; 1607 } 1608 } 1609 1610 static int coroutine_fn bdrv_qed_co_check(BlockDriverState *bs, 1611 BdrvCheckResult *result, 1612 BdrvCheckMode fix) 1613 { 1614 BDRVQEDState *s = bs->opaque; 1615 int ret; 1616 1617 qemu_co_mutex_lock(&s->table_lock); 1618 ret = qed_check(s, result, !!fix); 1619 qemu_co_mutex_unlock(&s->table_lock); 1620 1621 return ret; 1622 } 1623 1624 static QemuOptsList qed_create_opts = { 1625 .name = "qed-create-opts", 1626 .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head), 1627 .desc = { 1628 { 1629 .name = BLOCK_OPT_SIZE, 1630 .type = QEMU_OPT_SIZE, 1631 .help = "Virtual disk size" 1632 }, 1633 { 1634 .name = BLOCK_OPT_BACKING_FILE, 1635 .type = QEMU_OPT_STRING, 1636 .help = "File name of a base image" 1637 }, 1638 { 1639 .name = BLOCK_OPT_BACKING_FMT, 1640 .type = QEMU_OPT_STRING, 1641 .help = "Image format of the base image" 1642 }, 1643 { 1644 .name = BLOCK_OPT_CLUSTER_SIZE, 1645 .type = QEMU_OPT_SIZE, 1646 .help = "Cluster size (in bytes)", 1647 .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE) 1648 }, 1649 { 1650 .name = BLOCK_OPT_TABLE_SIZE, 1651 .type = QEMU_OPT_SIZE, 1652 .help = "L1/L2 table size (in clusters)" 1653 }, 1654 { /* end of list */ } 1655 } 1656 }; 1657 1658 static BlockDriver bdrv_qed = { 1659 .format_name = "qed", 1660 .instance_size = sizeof(BDRVQEDState), 1661 .create_opts = &qed_create_opts, 1662 .supports_backing = true, 1663 1664 .bdrv_probe = bdrv_qed_probe, 1665 .bdrv_open = bdrv_qed_open, 1666 .bdrv_close = bdrv_qed_close, 1667 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare, 1668 .bdrv_child_perm = bdrv_format_default_perms, 1669 .bdrv_co_create = bdrv_qed_co_create, 1670 .bdrv_co_create_opts = bdrv_qed_co_create_opts, 1671 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1672 .bdrv_co_block_status = bdrv_qed_co_block_status, 1673 .bdrv_co_readv = bdrv_qed_co_readv, 1674 .bdrv_co_writev = bdrv_qed_co_writev, 1675 .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes, 1676 .bdrv_co_truncate = bdrv_qed_co_truncate, 1677 .bdrv_getlength = bdrv_qed_getlength, 1678 .bdrv_get_info = bdrv_qed_get_info, 1679 .bdrv_refresh_limits = bdrv_qed_refresh_limits, 1680 .bdrv_change_backing_file = bdrv_qed_change_backing_file, 1681 .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache, 1682 .bdrv_co_check = bdrv_qed_co_check, 1683 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context, 1684 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context, 1685 .bdrv_co_drain_begin = bdrv_qed_co_drain_begin, 1686 }; 1687 1688 static void bdrv_qed_init(void) 1689 { 1690 bdrv_register(&bdrv_qed); 1691 } 1692 1693 block_init(bdrv_qed_init); 1694