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