1 /* 2 * QEMU Enhanced Disk Format 3 * 4 * Copyright IBM, Corp. 2010 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 8 * Anthony Liguori <aliguori@us.ibm.com> 9 * 10 * This work is licensed under the terms of the GNU LGPL, version 2 or later. 11 * See the COPYING.LIB file in the top-level directory. 12 * 13 */ 14 15 #include "qemu/osdep.h" 16 #include "block/qdict.h" 17 #include "qapi/error.h" 18 #include "qemu/timer.h" 19 #include "qemu/bswap.h" 20 #include "qemu/option.h" 21 #include "trace.h" 22 #include "qed.h" 23 #include "sysemu/block-backend.h" 24 #include "qapi/qmp/qdict.h" 25 #include "qapi/qobject-input-visitor.h" 26 #include "qapi/qapi-visit-block-core.h" 27 28 static QemuOptsList qed_create_opts; 29 30 static int bdrv_qed_probe(const uint8_t *buf, int buf_size, 31 const char *filename) 32 { 33 const QEDHeader *header = (const QEDHeader *)buf; 34 35 if (buf_size < sizeof(*header)) { 36 return 0; 37 } 38 if (le32_to_cpu(header->magic) != QED_MAGIC) { 39 return 0; 40 } 41 return 100; 42 } 43 44 /** 45 * Check whether an image format is raw 46 * 47 * @fmt: Backing file format, may be NULL 48 */ 49 static bool qed_fmt_is_raw(const char *fmt) 50 { 51 return fmt && strcmp(fmt, "raw") == 0; 52 } 53 54 static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu) 55 { 56 cpu->magic = le32_to_cpu(le->magic); 57 cpu->cluster_size = le32_to_cpu(le->cluster_size); 58 cpu->table_size = le32_to_cpu(le->table_size); 59 cpu->header_size = le32_to_cpu(le->header_size); 60 cpu->features = le64_to_cpu(le->features); 61 cpu->compat_features = le64_to_cpu(le->compat_features); 62 cpu->autoclear_features = le64_to_cpu(le->autoclear_features); 63 cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset); 64 cpu->image_size = le64_to_cpu(le->image_size); 65 cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset); 66 cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size); 67 } 68 69 static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le) 70 { 71 le->magic = cpu_to_le32(cpu->magic); 72 le->cluster_size = cpu_to_le32(cpu->cluster_size); 73 le->table_size = cpu_to_le32(cpu->table_size); 74 le->header_size = cpu_to_le32(cpu->header_size); 75 le->features = cpu_to_le64(cpu->features); 76 le->compat_features = cpu_to_le64(cpu->compat_features); 77 le->autoclear_features = cpu_to_le64(cpu->autoclear_features); 78 le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset); 79 le->image_size = cpu_to_le64(cpu->image_size); 80 le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset); 81 le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size); 82 } 83 84 int qed_write_header_sync(BDRVQEDState *s) 85 { 86 QEDHeader le; 87 int ret; 88 89 qed_header_cpu_to_le(&s->header, &le); 90 ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le)); 91 if (ret != sizeof(le)) { 92 return ret; 93 } 94 return 0; 95 } 96 97 /** 98 * Update header in-place (does not rewrite backing filename or other strings) 99 * 100 * This function only updates known header fields in-place and does not affect 101 * extra data after the QED header. 102 * 103 * No new allocating reqs can start while this function runs. 104 */ 105 static int coroutine_fn qed_write_header(BDRVQEDState *s) 106 { 107 /* We must write full sectors for O_DIRECT but cannot necessarily generate 108 * the data following the header if an unrecognized compat feature is 109 * active. Therefore, first read the sectors containing the header, update 110 * them, and write back. 111 */ 112 113 int nsectors = DIV_ROUND_UP(sizeof(QEDHeader), BDRV_SECTOR_SIZE); 114 size_t len = nsectors * BDRV_SECTOR_SIZE; 115 uint8_t *buf; 116 QEMUIOVector qiov; 117 int ret; 118 119 assert(s->allocating_acb || s->allocating_write_reqs_plugged); 120 121 buf = qemu_blockalign(s->bs, len); 122 qemu_iovec_init_buf(&qiov, buf, len); 123 124 ret = bdrv_co_preadv(s->bs->file, 0, qiov.size, &qiov, 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_pwritev(s->bs->file, 0, qiov.size, &qiov, 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(BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL); 655 ret = blk_insert_bs(blk, bs, errp); 656 if (ret < 0) { 657 goto out; 658 } 659 blk_set_allow_write_beyond_eof(blk, true); 660 661 /* Prepare image format */ 662 header = (QEDHeader) { 663 .magic = QED_MAGIC, 664 .cluster_size = qed_opts->cluster_size, 665 .table_size = qed_opts->table_size, 666 .header_size = 1, 667 .features = 0, 668 .compat_features = 0, 669 .l1_table_offset = qed_opts->cluster_size, 670 .image_size = qed_opts->size, 671 }; 672 673 l1_size = header.cluster_size * header.table_size; 674 675 /* File must start empty and grow, check truncate is supported */ 676 ret = blk_truncate(blk, 0, PREALLOC_MODE_OFF, errp); 677 if (ret < 0) { 678 goto out; 679 } 680 681 if (qed_opts->has_backing_file) { 682 header.features |= QED_F_BACKING_FILE; 683 header.backing_filename_offset = sizeof(le_header); 684 header.backing_filename_size = strlen(qed_opts->backing_file); 685 686 if (qed_opts->has_backing_fmt) { 687 const char *backing_fmt = BlockdevDriver_str(qed_opts->backing_fmt); 688 if (qed_fmt_is_raw(backing_fmt)) { 689 header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 690 } 691 } 692 } 693 694 qed_header_cpu_to_le(&header, &le_header); 695 ret = blk_pwrite(blk, 0, &le_header, sizeof(le_header), 0); 696 if (ret < 0) { 697 goto out; 698 } 699 ret = blk_pwrite(blk, sizeof(le_header), qed_opts->backing_file, 700 header.backing_filename_size, 0); 701 if (ret < 0) { 702 goto out; 703 } 704 705 l1_table = g_malloc0(l1_size); 706 ret = blk_pwrite(blk, header.l1_table_offset, l1_table, l1_size, 0); 707 if (ret < 0) { 708 goto out; 709 } 710 711 ret = 0; /* success */ 712 out: 713 g_free(l1_table); 714 blk_unref(blk); 715 bdrv_unref(bs); 716 return ret; 717 } 718 719 static int coroutine_fn bdrv_qed_co_create_opts(const char *filename, 720 QemuOpts *opts, 721 Error **errp) 722 { 723 BlockdevCreateOptions *create_options = NULL; 724 QDict *qdict; 725 Visitor *v; 726 BlockDriverState *bs = NULL; 727 Error *local_err = NULL; 728 int ret; 729 730 static const QDictRenames opt_renames[] = { 731 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 732 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 733 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 734 { BLOCK_OPT_TABLE_SIZE, "table-size" }, 735 { NULL, NULL }, 736 }; 737 738 /* Parse options and convert legacy syntax */ 739 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qed_create_opts, true); 740 741 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 742 ret = -EINVAL; 743 goto fail; 744 } 745 746 /* Create and open the file (protocol layer) */ 747 ret = bdrv_create_file(filename, opts, &local_err); 748 if (ret < 0) { 749 error_propagate(errp, local_err); 750 goto fail; 751 } 752 753 bs = bdrv_open(filename, NULL, NULL, 754 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 755 if (bs == NULL) { 756 ret = -EIO; 757 goto fail; 758 } 759 760 /* Now get the QAPI type BlockdevCreateOptions */ 761 qdict_put_str(qdict, "driver", "qed"); 762 qdict_put_str(qdict, "file", bs->node_name); 763 764 v = qobject_input_visitor_new_flat_confused(qdict, errp); 765 if (!v) { 766 ret = -EINVAL; 767 goto fail; 768 } 769 770 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); 771 visit_free(v); 772 773 if (local_err) { 774 error_propagate(errp, local_err); 775 ret = -EINVAL; 776 goto fail; 777 } 778 779 /* Silently round up size */ 780 assert(create_options->driver == BLOCKDEV_DRIVER_QED); 781 create_options->u.qed.size = 782 ROUND_UP(create_options->u.qed.size, BDRV_SECTOR_SIZE); 783 784 /* Create the qed image (format layer) */ 785 ret = bdrv_qed_co_create(create_options, errp); 786 787 fail: 788 qobject_unref(qdict); 789 bdrv_unref(bs); 790 qapi_free_BlockdevCreateOptions(create_options); 791 return ret; 792 } 793 794 static int coroutine_fn bdrv_qed_co_block_status(BlockDriverState *bs, 795 bool want_zero, 796 int64_t pos, int64_t bytes, 797 int64_t *pnum, int64_t *map, 798 BlockDriverState **file) 799 { 800 BDRVQEDState *s = bs->opaque; 801 size_t len = MIN(bytes, SIZE_MAX); 802 int status; 803 QEDRequest request = { .l2_table = NULL }; 804 uint64_t offset; 805 int ret; 806 807 qemu_co_mutex_lock(&s->table_lock); 808 ret = qed_find_cluster(s, &request, pos, &len, &offset); 809 810 *pnum = len; 811 switch (ret) { 812 case QED_CLUSTER_FOUND: 813 *map = offset | qed_offset_into_cluster(s, pos); 814 status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 815 *file = bs->file->bs; 816 break; 817 case QED_CLUSTER_ZERO: 818 status = BDRV_BLOCK_ZERO; 819 break; 820 case QED_CLUSTER_L2: 821 case QED_CLUSTER_L1: 822 status = 0; 823 break; 824 default: 825 assert(ret < 0); 826 status = ret; 827 break; 828 } 829 830 qed_unref_l2_cache_entry(request.l2_table); 831 qemu_co_mutex_unlock(&s->table_lock); 832 833 return status; 834 } 835 836 static BDRVQEDState *acb_to_s(QEDAIOCB *acb) 837 { 838 return acb->bs->opaque; 839 } 840 841 /** 842 * Read from the backing file or zero-fill if no backing file 843 * 844 * @s: QED state 845 * @pos: Byte position in device 846 * @qiov: Destination I/O vector 847 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here 848 * @cb: Completion function 849 * @opaque: User data for completion function 850 * 851 * This function reads qiov->size bytes starting at pos from the backing file. 852 * If there is no backing file then zeroes are read. 853 */ 854 static int coroutine_fn qed_read_backing_file(BDRVQEDState *s, uint64_t pos, 855 QEMUIOVector *qiov, 856 QEMUIOVector **backing_qiov) 857 { 858 uint64_t backing_length = 0; 859 size_t size; 860 int ret; 861 862 /* If there is a backing file, get its length. Treat the absence of a 863 * backing file like a zero length backing file. 864 */ 865 if (s->bs->backing) { 866 int64_t l = bdrv_getlength(s->bs->backing->bs); 867 if (l < 0) { 868 return l; 869 } 870 backing_length = l; 871 } 872 873 /* Zero all sectors if reading beyond the end of the backing file */ 874 if (pos >= backing_length || 875 pos + qiov->size > backing_length) { 876 qemu_iovec_memset(qiov, 0, 0, qiov->size); 877 } 878 879 /* Complete now if there are no backing file sectors to read */ 880 if (pos >= backing_length) { 881 return 0; 882 } 883 884 /* If the read straddles the end of the backing file, shorten it */ 885 size = MIN((uint64_t)backing_length - pos, qiov->size); 886 887 assert(*backing_qiov == NULL); 888 *backing_qiov = g_new(QEMUIOVector, 1); 889 qemu_iovec_init(*backing_qiov, qiov->niov); 890 qemu_iovec_concat(*backing_qiov, qiov, 0, size); 891 892 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); 893 ret = bdrv_co_preadv(s->bs->backing, pos, size, *backing_qiov, 0); 894 if (ret < 0) { 895 return ret; 896 } 897 return 0; 898 } 899 900 /** 901 * Copy data from backing file into the image 902 * 903 * @s: QED state 904 * @pos: Byte position in device 905 * @len: Number of bytes 906 * @offset: Byte offset in image file 907 */ 908 static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s, 909 uint64_t pos, uint64_t len, 910 uint64_t offset) 911 { 912 QEMUIOVector qiov; 913 QEMUIOVector *backing_qiov = NULL; 914 int ret; 915 916 /* Skip copy entirely if there is no work to do */ 917 if (len == 0) { 918 return 0; 919 } 920 921 qemu_iovec_init_buf(&qiov, qemu_blockalign(s->bs, len), len); 922 923 ret = qed_read_backing_file(s, pos, &qiov, &backing_qiov); 924 925 if (backing_qiov) { 926 qemu_iovec_destroy(backing_qiov); 927 g_free(backing_qiov); 928 backing_qiov = NULL; 929 } 930 931 if (ret) { 932 goto out; 933 } 934 935 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); 936 ret = bdrv_co_pwritev(s->bs->file, offset, qiov.size, &qiov, 0); 937 if (ret < 0) { 938 goto out; 939 } 940 ret = 0; 941 out: 942 qemu_vfree(qemu_iovec_buf(&qiov)); 943 return ret; 944 } 945 946 /** 947 * Link one or more contiguous clusters into a table 948 * 949 * @s: QED state 950 * @table: L2 table 951 * @index: First cluster index 952 * @n: Number of contiguous clusters 953 * @cluster: First cluster offset 954 * 955 * The cluster offset may be an allocated byte offset in the image file, the 956 * zero cluster marker, or the unallocated cluster marker. 957 * 958 * Called with table_lock held. 959 */ 960 static void coroutine_fn qed_update_l2_table(BDRVQEDState *s, QEDTable *table, 961 int index, unsigned int n, 962 uint64_t cluster) 963 { 964 int i; 965 for (i = index; i < index + n; i++) { 966 table->offsets[i] = cluster; 967 if (!qed_offset_is_unalloc_cluster(cluster) && 968 !qed_offset_is_zero_cluster(cluster)) { 969 cluster += s->header.cluster_size; 970 } 971 } 972 } 973 974 /* Called with table_lock held. */ 975 static void coroutine_fn qed_aio_complete(QEDAIOCB *acb) 976 { 977 BDRVQEDState *s = acb_to_s(acb); 978 979 /* Free resources */ 980 qemu_iovec_destroy(&acb->cur_qiov); 981 qed_unref_l2_cache_entry(acb->request.l2_table); 982 983 /* Free the buffer we may have allocated for zero writes */ 984 if (acb->flags & QED_AIOCB_ZERO) { 985 qemu_vfree(acb->qiov->iov[0].iov_base); 986 acb->qiov->iov[0].iov_base = NULL; 987 } 988 989 /* Start next allocating write request waiting behind this one. Note that 990 * requests enqueue themselves when they first hit an unallocated cluster 991 * but they wait until the entire request is finished before waking up the 992 * next request in the queue. This ensures that we don't cycle through 993 * requests multiple times but rather finish one at a time completely. 994 */ 995 if (acb == s->allocating_acb) { 996 s->allocating_acb = NULL; 997 if (!qemu_co_queue_empty(&s->allocating_write_reqs)) { 998 qemu_co_queue_next(&s->allocating_write_reqs); 999 } else if (s->header.features & QED_F_NEED_CHECK) { 1000 qed_start_need_check_timer(s); 1001 } 1002 } 1003 } 1004 1005 /** 1006 * Update L1 table with new L2 table offset and write it out 1007 * 1008 * Called with table_lock held. 1009 */ 1010 static int coroutine_fn qed_aio_write_l1_update(QEDAIOCB *acb) 1011 { 1012 BDRVQEDState *s = acb_to_s(acb); 1013 CachedL2Table *l2_table = acb->request.l2_table; 1014 uint64_t l2_offset = l2_table->offset; 1015 int index, ret; 1016 1017 index = qed_l1_index(s, acb->cur_pos); 1018 s->l1_table->offsets[index] = l2_table->offset; 1019 1020 ret = qed_write_l1_table(s, index, 1); 1021 1022 /* Commit the current L2 table to the cache */ 1023 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 1024 1025 /* This is guaranteed to succeed because we just committed the entry to the 1026 * cache. 1027 */ 1028 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 1029 assert(acb->request.l2_table != NULL); 1030 1031 return ret; 1032 } 1033 1034 1035 /** 1036 * Update L2 table with new cluster offsets and write them out 1037 * 1038 * Called with table_lock held. 1039 */ 1040 static int coroutine_fn qed_aio_write_l2_update(QEDAIOCB *acb, uint64_t offset) 1041 { 1042 BDRVQEDState *s = acb_to_s(acb); 1043 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1; 1044 int index, ret; 1045 1046 if (need_alloc) { 1047 qed_unref_l2_cache_entry(acb->request.l2_table); 1048 acb->request.l2_table = qed_new_l2_table(s); 1049 } 1050 1051 index = qed_l2_index(s, acb->cur_pos); 1052 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, 1053 offset); 1054 1055 if (need_alloc) { 1056 /* Write out the whole new L2 table */ 1057 ret = qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true); 1058 if (ret) { 1059 return ret; 1060 } 1061 return qed_aio_write_l1_update(acb); 1062 } else { 1063 /* Write out only the updated part of the L2 table */ 1064 ret = qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, 1065 false); 1066 if (ret) { 1067 return ret; 1068 } 1069 } 1070 return 0; 1071 } 1072 1073 /** 1074 * Write data to the image file 1075 * 1076 * Called with table_lock *not* held. 1077 */ 1078 static int coroutine_fn qed_aio_write_main(QEDAIOCB *acb) 1079 { 1080 BDRVQEDState *s = acb_to_s(acb); 1081 uint64_t offset = acb->cur_cluster + 1082 qed_offset_into_cluster(s, acb->cur_pos); 1083 1084 trace_qed_aio_write_main(s, acb, 0, offset, acb->cur_qiov.size); 1085 1086 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); 1087 return bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size, 1088 &acb->cur_qiov, 0); 1089 } 1090 1091 /** 1092 * Populate untouched regions of new data cluster 1093 * 1094 * Called with table_lock held. 1095 */ 1096 static int coroutine_fn qed_aio_write_cow(QEDAIOCB *acb) 1097 { 1098 BDRVQEDState *s = acb_to_s(acb); 1099 uint64_t start, len, offset; 1100 int ret; 1101 1102 qemu_co_mutex_unlock(&s->table_lock); 1103 1104 /* Populate front untouched region of new data cluster */ 1105 start = qed_start_of_cluster(s, acb->cur_pos); 1106 len = qed_offset_into_cluster(s, acb->cur_pos); 1107 1108 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); 1109 ret = qed_copy_from_backing_file(s, start, len, acb->cur_cluster); 1110 if (ret < 0) { 1111 goto out; 1112 } 1113 1114 /* Populate back untouched region of new data cluster */ 1115 start = acb->cur_pos + acb->cur_qiov.size; 1116 len = qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start; 1117 offset = acb->cur_cluster + 1118 qed_offset_into_cluster(s, acb->cur_pos) + 1119 acb->cur_qiov.size; 1120 1121 trace_qed_aio_write_postfill(s, acb, start, len, offset); 1122 ret = qed_copy_from_backing_file(s, start, len, offset); 1123 if (ret < 0) { 1124 goto out; 1125 } 1126 1127 ret = qed_aio_write_main(acb); 1128 if (ret < 0) { 1129 goto out; 1130 } 1131 1132 if (s->bs->backing) { 1133 /* 1134 * Flush new data clusters before updating the L2 table 1135 * 1136 * This flush is necessary when a backing file is in use. A crash 1137 * during an allocating write could result in empty clusters in the 1138 * image. If the write only touched a subregion of the cluster, 1139 * then backing image sectors have been lost in the untouched 1140 * region. The solution is to flush after writing a new data 1141 * cluster and before updating the L2 table. 1142 */ 1143 ret = bdrv_co_flush(s->bs->file->bs); 1144 } 1145 1146 out: 1147 qemu_co_mutex_lock(&s->table_lock); 1148 return ret; 1149 } 1150 1151 /** 1152 * Check if the QED_F_NEED_CHECK bit should be set during allocating write 1153 */ 1154 static bool qed_should_set_need_check(BDRVQEDState *s) 1155 { 1156 /* The flush before L2 update path ensures consistency */ 1157 if (s->bs->backing) { 1158 return false; 1159 } 1160 1161 return !(s->header.features & QED_F_NEED_CHECK); 1162 } 1163 1164 /** 1165 * Write new data cluster 1166 * 1167 * @acb: Write request 1168 * @len: Length in bytes 1169 * 1170 * This path is taken when writing to previously unallocated clusters. 1171 * 1172 * Called with table_lock held. 1173 */ 1174 static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 1175 { 1176 BDRVQEDState *s = acb_to_s(acb); 1177 int ret; 1178 1179 /* Cancel timer when the first allocating request comes in */ 1180 if (s->allocating_acb == NULL) { 1181 qed_cancel_need_check_timer(s); 1182 } 1183 1184 /* Freeze this request if another allocating write is in progress */ 1185 if (s->allocating_acb != acb || s->allocating_write_reqs_plugged) { 1186 if (s->allocating_acb != NULL) { 1187 qemu_co_queue_wait(&s->allocating_write_reqs, &s->table_lock); 1188 assert(s->allocating_acb == NULL); 1189 } 1190 s->allocating_acb = acb; 1191 return -EAGAIN; /* start over with looking up table entries */ 1192 } 1193 1194 acb->cur_nclusters = qed_bytes_to_clusters(s, 1195 qed_offset_into_cluster(s, acb->cur_pos) + len); 1196 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1197 1198 if (acb->flags & QED_AIOCB_ZERO) { 1199 /* Skip ahead if the clusters are already zero */ 1200 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) { 1201 return 0; 1202 } 1203 acb->cur_cluster = 1; 1204 } else { 1205 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); 1206 } 1207 1208 if (qed_should_set_need_check(s)) { 1209 s->header.features |= QED_F_NEED_CHECK; 1210 ret = qed_write_header(s); 1211 if (ret < 0) { 1212 return ret; 1213 } 1214 } 1215 1216 if (!(acb->flags & QED_AIOCB_ZERO)) { 1217 ret = qed_aio_write_cow(acb); 1218 if (ret < 0) { 1219 return ret; 1220 } 1221 } 1222 1223 return qed_aio_write_l2_update(acb, acb->cur_cluster); 1224 } 1225 1226 /** 1227 * Write data cluster in place 1228 * 1229 * @acb: Write request 1230 * @offset: Cluster offset in bytes 1231 * @len: Length in bytes 1232 * 1233 * This path is taken when writing to already allocated clusters. 1234 * 1235 * Called with table_lock held. 1236 */ 1237 static int coroutine_fn qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, 1238 size_t len) 1239 { 1240 BDRVQEDState *s = acb_to_s(acb); 1241 int r; 1242 1243 qemu_co_mutex_unlock(&s->table_lock); 1244 1245 /* Allocate buffer for zero writes */ 1246 if (acb->flags & QED_AIOCB_ZERO) { 1247 struct iovec *iov = acb->qiov->iov; 1248 1249 if (!iov->iov_base) { 1250 iov->iov_base = qemu_try_blockalign(acb->bs, iov->iov_len); 1251 if (iov->iov_base == NULL) { 1252 r = -ENOMEM; 1253 goto out; 1254 } 1255 memset(iov->iov_base, 0, iov->iov_len); 1256 } 1257 } 1258 1259 /* Calculate the I/O vector */ 1260 acb->cur_cluster = offset; 1261 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1262 1263 /* Do the actual write. */ 1264 r = qed_aio_write_main(acb); 1265 out: 1266 qemu_co_mutex_lock(&s->table_lock); 1267 return r; 1268 } 1269 1270 /** 1271 * Write data cluster 1272 * 1273 * @opaque: Write request 1274 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1275 * @offset: Cluster offset in bytes 1276 * @len: Length in bytes 1277 * 1278 * Called with table_lock held. 1279 */ 1280 static int coroutine_fn qed_aio_write_data(void *opaque, int ret, 1281 uint64_t offset, size_t len) 1282 { 1283 QEDAIOCB *acb = opaque; 1284 1285 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); 1286 1287 acb->find_cluster_ret = ret; 1288 1289 switch (ret) { 1290 case QED_CLUSTER_FOUND: 1291 return qed_aio_write_inplace(acb, offset, len); 1292 1293 case QED_CLUSTER_L2: 1294 case QED_CLUSTER_L1: 1295 case QED_CLUSTER_ZERO: 1296 return qed_aio_write_alloc(acb, len); 1297 1298 default: 1299 g_assert_not_reached(); 1300 } 1301 } 1302 1303 /** 1304 * Read data cluster 1305 * 1306 * @opaque: Read request 1307 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1308 * @offset: Cluster offset in bytes 1309 * @len: Length in bytes 1310 * 1311 * Called with table_lock held. 1312 */ 1313 static int coroutine_fn qed_aio_read_data(void *opaque, int ret, 1314 uint64_t offset, size_t len) 1315 { 1316 QEDAIOCB *acb = opaque; 1317 BDRVQEDState *s = acb_to_s(acb); 1318 BlockDriverState *bs = acb->bs; 1319 int r; 1320 1321 qemu_co_mutex_unlock(&s->table_lock); 1322 1323 /* Adjust offset into cluster */ 1324 offset += qed_offset_into_cluster(s, acb->cur_pos); 1325 1326 trace_qed_aio_read_data(s, acb, ret, offset, len); 1327 1328 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1329 1330 /* Handle zero cluster and backing file reads, otherwise read 1331 * data cluster directly. 1332 */ 1333 if (ret == QED_CLUSTER_ZERO) { 1334 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size); 1335 r = 0; 1336 } else if (ret != QED_CLUSTER_FOUND) { 1337 r = qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov, 1338 &acb->backing_qiov); 1339 } else { 1340 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 1341 r = bdrv_co_preadv(bs->file, offset, acb->cur_qiov.size, 1342 &acb->cur_qiov, 0); 1343 } 1344 1345 qemu_co_mutex_lock(&s->table_lock); 1346 return r; 1347 } 1348 1349 /** 1350 * Begin next I/O or complete the request 1351 */ 1352 static int coroutine_fn qed_aio_next_io(QEDAIOCB *acb) 1353 { 1354 BDRVQEDState *s = acb_to_s(acb); 1355 uint64_t offset; 1356 size_t len; 1357 int ret; 1358 1359 qemu_co_mutex_lock(&s->table_lock); 1360 while (1) { 1361 trace_qed_aio_next_io(s, acb, 0, acb->cur_pos + acb->cur_qiov.size); 1362 1363 if (acb->backing_qiov) { 1364 qemu_iovec_destroy(acb->backing_qiov); 1365 g_free(acb->backing_qiov); 1366 acb->backing_qiov = NULL; 1367 } 1368 1369 acb->qiov_offset += acb->cur_qiov.size; 1370 acb->cur_pos += acb->cur_qiov.size; 1371 qemu_iovec_reset(&acb->cur_qiov); 1372 1373 /* Complete request */ 1374 if (acb->cur_pos >= acb->end_pos) { 1375 ret = 0; 1376 break; 1377 } 1378 1379 /* Find next cluster and start I/O */ 1380 len = acb->end_pos - acb->cur_pos; 1381 ret = qed_find_cluster(s, &acb->request, acb->cur_pos, &len, &offset); 1382 if (ret < 0) { 1383 break; 1384 } 1385 1386 if (acb->flags & QED_AIOCB_WRITE) { 1387 ret = qed_aio_write_data(acb, ret, offset, len); 1388 } else { 1389 ret = qed_aio_read_data(acb, ret, offset, len); 1390 } 1391 1392 if (ret < 0 && ret != -EAGAIN) { 1393 break; 1394 } 1395 } 1396 1397 trace_qed_aio_complete(s, acb, ret); 1398 qed_aio_complete(acb); 1399 qemu_co_mutex_unlock(&s->table_lock); 1400 return ret; 1401 } 1402 1403 static int coroutine_fn qed_co_request(BlockDriverState *bs, int64_t sector_num, 1404 QEMUIOVector *qiov, int nb_sectors, 1405 int flags) 1406 { 1407 QEDAIOCB acb = { 1408 .bs = bs, 1409 .cur_pos = (uint64_t) sector_num * BDRV_SECTOR_SIZE, 1410 .end_pos = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE, 1411 .qiov = qiov, 1412 .flags = flags, 1413 }; 1414 qemu_iovec_init(&acb.cur_qiov, qiov->niov); 1415 1416 trace_qed_aio_setup(bs->opaque, &acb, sector_num, nb_sectors, NULL, flags); 1417 1418 /* Start request */ 1419 return qed_aio_next_io(&acb); 1420 } 1421 1422 static int coroutine_fn bdrv_qed_co_readv(BlockDriverState *bs, 1423 int64_t sector_num, int nb_sectors, 1424 QEMUIOVector *qiov) 1425 { 1426 return qed_co_request(bs, sector_num, qiov, nb_sectors, 0); 1427 } 1428 1429 static int coroutine_fn bdrv_qed_co_writev(BlockDriverState *bs, 1430 int64_t sector_num, int nb_sectors, 1431 QEMUIOVector *qiov, int flags) 1432 { 1433 assert(!flags); 1434 return qed_co_request(bs, sector_num, qiov, nb_sectors, QED_AIOCB_WRITE); 1435 } 1436 1437 static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs, 1438 int64_t offset, 1439 int bytes, 1440 BdrvRequestFlags flags) 1441 { 1442 BDRVQEDState *s = bs->opaque; 1443 1444 /* 1445 * Zero writes start without an I/O buffer. If a buffer becomes necessary 1446 * then it will be allocated during request processing. 1447 */ 1448 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes); 1449 1450 /* Fall back if the request is not aligned */ 1451 if (qed_offset_into_cluster(s, offset) || 1452 qed_offset_into_cluster(s, bytes)) { 1453 return -ENOTSUP; 1454 } 1455 1456 return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov, 1457 bytes >> BDRV_SECTOR_BITS, 1458 QED_AIOCB_WRITE | QED_AIOCB_ZERO); 1459 } 1460 1461 static int coroutine_fn bdrv_qed_co_truncate(BlockDriverState *bs, 1462 int64_t offset, 1463 PreallocMode prealloc, 1464 Error **errp) 1465 { 1466 BDRVQEDState *s = bs->opaque; 1467 uint64_t old_image_size; 1468 int ret; 1469 1470 if (prealloc != PREALLOC_MODE_OFF) { 1471 error_setg(errp, "Unsupported preallocation mode '%s'", 1472 PreallocMode_str(prealloc)); 1473 return -ENOTSUP; 1474 } 1475 1476 if (!qed_is_image_size_valid(offset, s->header.cluster_size, 1477 s->header.table_size)) { 1478 error_setg(errp, "Invalid image size specified"); 1479 return -EINVAL; 1480 } 1481 1482 if ((uint64_t)offset < s->header.image_size) { 1483 error_setg(errp, "Shrinking images is currently not supported"); 1484 return -ENOTSUP; 1485 } 1486 1487 old_image_size = s->header.image_size; 1488 s->header.image_size = offset; 1489 ret = qed_write_header_sync(s); 1490 if (ret < 0) { 1491 s->header.image_size = old_image_size; 1492 error_setg_errno(errp, -ret, "Failed to update the image size"); 1493 } 1494 return ret; 1495 } 1496 1497 static int64_t bdrv_qed_getlength(BlockDriverState *bs) 1498 { 1499 BDRVQEDState *s = bs->opaque; 1500 return s->header.image_size; 1501 } 1502 1503 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1504 { 1505 BDRVQEDState *s = bs->opaque; 1506 1507 memset(bdi, 0, sizeof(*bdi)); 1508 bdi->cluster_size = s->header.cluster_size; 1509 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK; 1510 bdi->unallocated_blocks_are_zero = true; 1511 return 0; 1512 } 1513 1514 static int bdrv_qed_change_backing_file(BlockDriverState *bs, 1515 const char *backing_file, 1516 const char *backing_fmt) 1517 { 1518 BDRVQEDState *s = bs->opaque; 1519 QEDHeader new_header, le_header; 1520 void *buffer; 1521 size_t buffer_len, backing_file_len; 1522 int ret; 1523 1524 /* Refuse to set backing filename if unknown compat feature bits are 1525 * active. If the image uses an unknown compat feature then we may not 1526 * know the layout of data following the header structure and cannot safely 1527 * add a new string. 1528 */ 1529 if (backing_file && (s->header.compat_features & 1530 ~QED_COMPAT_FEATURE_MASK)) { 1531 return -ENOTSUP; 1532 } 1533 1534 memcpy(&new_header, &s->header, sizeof(new_header)); 1535 1536 new_header.features &= ~(QED_F_BACKING_FILE | 1537 QED_F_BACKING_FORMAT_NO_PROBE); 1538 1539 /* Adjust feature flags */ 1540 if (backing_file) { 1541 new_header.features |= QED_F_BACKING_FILE; 1542 1543 if (qed_fmt_is_raw(backing_fmt)) { 1544 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 1545 } 1546 } 1547 1548 /* Calculate new header size */ 1549 backing_file_len = 0; 1550 1551 if (backing_file) { 1552 backing_file_len = strlen(backing_file); 1553 } 1554 1555 buffer_len = sizeof(new_header); 1556 new_header.backing_filename_offset = buffer_len; 1557 new_header.backing_filename_size = backing_file_len; 1558 buffer_len += backing_file_len; 1559 1560 /* Make sure we can rewrite header without failing */ 1561 if (buffer_len > new_header.header_size * new_header.cluster_size) { 1562 return -ENOSPC; 1563 } 1564 1565 /* Prepare new header */ 1566 buffer = g_malloc(buffer_len); 1567 1568 qed_header_cpu_to_le(&new_header, &le_header); 1569 memcpy(buffer, &le_header, sizeof(le_header)); 1570 buffer_len = sizeof(le_header); 1571 1572 if (backing_file) { 1573 memcpy(buffer + buffer_len, backing_file, backing_file_len); 1574 buffer_len += backing_file_len; 1575 } 1576 1577 /* Write new header */ 1578 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len); 1579 g_free(buffer); 1580 if (ret == 0) { 1581 memcpy(&s->header, &new_header, sizeof(new_header)); 1582 } 1583 return ret; 1584 } 1585 1586 static void coroutine_fn bdrv_qed_co_invalidate_cache(BlockDriverState *bs, 1587 Error **errp) 1588 { 1589 BDRVQEDState *s = bs->opaque; 1590 Error *local_err = NULL; 1591 int ret; 1592 1593 bdrv_qed_close(bs); 1594 1595 bdrv_qed_init_state(bs); 1596 qemu_co_mutex_lock(&s->table_lock); 1597 ret = bdrv_qed_do_open(bs, NULL, bs->open_flags, &local_err); 1598 qemu_co_mutex_unlock(&s->table_lock); 1599 if (local_err) { 1600 error_propagate_prepend(errp, local_err, 1601 "Could not reopen qed layer: "); 1602 return; 1603 } else if (ret < 0) { 1604 error_setg_errno(errp, -ret, "Could not reopen qed layer"); 1605 return; 1606 } 1607 } 1608 1609 static int bdrv_qed_co_check(BlockDriverState *bs, BdrvCheckResult *result, 1610 BdrvCheckMode fix) 1611 { 1612 BDRVQEDState *s = bs->opaque; 1613 int ret; 1614 1615 qemu_co_mutex_lock(&s->table_lock); 1616 ret = qed_check(s, result, !!fix); 1617 qemu_co_mutex_unlock(&s->table_lock); 1618 1619 return ret; 1620 } 1621 1622 static QemuOptsList qed_create_opts = { 1623 .name = "qed-create-opts", 1624 .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head), 1625 .desc = { 1626 { 1627 .name = BLOCK_OPT_SIZE, 1628 .type = QEMU_OPT_SIZE, 1629 .help = "Virtual disk size" 1630 }, 1631 { 1632 .name = BLOCK_OPT_BACKING_FILE, 1633 .type = QEMU_OPT_STRING, 1634 .help = "File name of a base image" 1635 }, 1636 { 1637 .name = BLOCK_OPT_BACKING_FMT, 1638 .type = QEMU_OPT_STRING, 1639 .help = "Image format of the base image" 1640 }, 1641 { 1642 .name = BLOCK_OPT_CLUSTER_SIZE, 1643 .type = QEMU_OPT_SIZE, 1644 .help = "Cluster size (in bytes)", 1645 .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE) 1646 }, 1647 { 1648 .name = BLOCK_OPT_TABLE_SIZE, 1649 .type = QEMU_OPT_SIZE, 1650 .help = "L1/L2 table size (in clusters)" 1651 }, 1652 { /* end of list */ } 1653 } 1654 }; 1655 1656 static BlockDriver bdrv_qed = { 1657 .format_name = "qed", 1658 .instance_size = sizeof(BDRVQEDState), 1659 .create_opts = &qed_create_opts, 1660 .supports_backing = true, 1661 1662 .bdrv_probe = bdrv_qed_probe, 1663 .bdrv_open = bdrv_qed_open, 1664 .bdrv_close = bdrv_qed_close, 1665 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare, 1666 .bdrv_child_perm = bdrv_format_default_perms, 1667 .bdrv_co_create = bdrv_qed_co_create, 1668 .bdrv_co_create_opts = bdrv_qed_co_create_opts, 1669 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1670 .bdrv_co_block_status = bdrv_qed_co_block_status, 1671 .bdrv_co_readv = bdrv_qed_co_readv, 1672 .bdrv_co_writev = bdrv_qed_co_writev, 1673 .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes, 1674 .bdrv_co_truncate = bdrv_qed_co_truncate, 1675 .bdrv_getlength = bdrv_qed_getlength, 1676 .bdrv_get_info = bdrv_qed_get_info, 1677 .bdrv_refresh_limits = bdrv_qed_refresh_limits, 1678 .bdrv_change_backing_file = bdrv_qed_change_backing_file, 1679 .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache, 1680 .bdrv_co_check = bdrv_qed_co_check, 1681 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context, 1682 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context, 1683 .bdrv_co_drain_begin = bdrv_qed_co_drain_begin, 1684 }; 1685 1686 static void bdrv_qed_init(void) 1687 { 1688 bdrv_register(&bdrv_qed); 1689 } 1690 1691 block_init(bdrv_qed_init); 1692