1 /* 2 * QEMU Enhanced Disk Format 3 * 4 * Copyright IBM, Corp. 2010 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 8 * Anthony Liguori <aliguori@us.ibm.com> 9 * 10 * This work is licensed under the terms of the GNU LGPL, version 2 or later. 11 * See the COPYING.LIB file in the top-level directory. 12 * 13 */ 14 15 #include "qemu/osdep.h" 16 #include "block/qdict.h" 17 #include "qapi/error.h" 18 #include "qemu/timer.h" 19 #include "qemu/bswap.h" 20 #include "qemu/main-loop.h" 21 #include "qemu/module.h" 22 #include "qemu/option.h" 23 #include "trace.h" 24 #include "qed.h" 25 #include "sysemu/block-backend.h" 26 #include "qapi/qmp/qdict.h" 27 #include "qapi/qobject-input-visitor.h" 28 #include "qapi/qapi-visit-block-core.h" 29 30 static QemuOptsList qed_create_opts; 31 32 static int bdrv_qed_probe(const uint8_t *buf, int buf_size, 33 const char *filename) 34 { 35 const QEDHeader *header = (const QEDHeader *)buf; 36 37 if (buf_size < sizeof(*header)) { 38 return 0; 39 } 40 if (le32_to_cpu(header->magic) != QED_MAGIC) { 41 return 0; 42 } 43 return 100; 44 } 45 46 /** 47 * Check whether an image format is raw 48 * 49 * @fmt: Backing file format, may be NULL 50 */ 51 static bool qed_fmt_is_raw(const char *fmt) 52 { 53 return fmt && strcmp(fmt, "raw") == 0; 54 } 55 56 static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu) 57 { 58 cpu->magic = le32_to_cpu(le->magic); 59 cpu->cluster_size = le32_to_cpu(le->cluster_size); 60 cpu->table_size = le32_to_cpu(le->table_size); 61 cpu->header_size = le32_to_cpu(le->header_size); 62 cpu->features = le64_to_cpu(le->features); 63 cpu->compat_features = le64_to_cpu(le->compat_features); 64 cpu->autoclear_features = le64_to_cpu(le->autoclear_features); 65 cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset); 66 cpu->image_size = le64_to_cpu(le->image_size); 67 cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset); 68 cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size); 69 } 70 71 static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le) 72 { 73 le->magic = cpu_to_le32(cpu->magic); 74 le->cluster_size = cpu_to_le32(cpu->cluster_size); 75 le->table_size = cpu_to_le32(cpu->table_size); 76 le->header_size = cpu_to_le32(cpu->header_size); 77 le->features = cpu_to_le64(cpu->features); 78 le->compat_features = cpu_to_le64(cpu->compat_features); 79 le->autoclear_features = cpu_to_le64(cpu->autoclear_features); 80 le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset); 81 le->image_size = cpu_to_le64(cpu->image_size); 82 le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset); 83 le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size); 84 } 85 86 int qed_write_header_sync(BDRVQEDState *s) 87 { 88 QEDHeader le; 89 int ret; 90 91 qed_header_cpu_to_le(&s->header, &le); 92 ret = bdrv_pwrite(s->bs->file, 0, &le, sizeof(le)); 93 if (ret != sizeof(le)) { 94 return ret; 95 } 96 return 0; 97 } 98 99 /** 100 * Update header in-place (does not rewrite backing filename or other strings) 101 * 102 * This function only updates known header fields in-place and does not affect 103 * extra data after the QED header. 104 * 105 * No new allocating reqs can start while this function runs. 106 */ 107 static int coroutine_fn qed_write_header(BDRVQEDState *s) 108 { 109 /* We must write full sectors for O_DIRECT but cannot necessarily generate 110 * the data following the header if an unrecognized compat feature is 111 * active. Therefore, first read the sectors containing the header, update 112 * them, and write back. 113 */ 114 115 int nsectors = DIV_ROUND_UP(sizeof(QEDHeader), BDRV_SECTOR_SIZE); 116 size_t len = nsectors * BDRV_SECTOR_SIZE; 117 uint8_t *buf; 118 int ret; 119 120 assert(s->allocating_acb || s->allocating_write_reqs_plugged); 121 122 buf = qemu_blockalign(s->bs, len); 123 124 ret = bdrv_co_pread(s->bs->file, 0, len, buf, 0); 125 if (ret < 0) { 126 goto out; 127 } 128 129 /* Update header */ 130 qed_header_cpu_to_le(&s->header, (QEDHeader *) buf); 131 132 ret = bdrv_co_pwrite(s->bs->file, 0, len, buf, 0); 133 if (ret < 0) { 134 goto out; 135 } 136 137 ret = 0; 138 out: 139 qemu_vfree(buf); 140 return ret; 141 } 142 143 static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size) 144 { 145 uint64_t table_entries; 146 uint64_t l2_size; 147 148 table_entries = (table_size * cluster_size) / sizeof(uint64_t); 149 l2_size = table_entries * cluster_size; 150 151 return l2_size * table_entries; 152 } 153 154 static bool qed_is_cluster_size_valid(uint32_t cluster_size) 155 { 156 if (cluster_size < QED_MIN_CLUSTER_SIZE || 157 cluster_size > QED_MAX_CLUSTER_SIZE) { 158 return false; 159 } 160 if (cluster_size & (cluster_size - 1)) { 161 return false; /* not power of 2 */ 162 } 163 return true; 164 } 165 166 static bool qed_is_table_size_valid(uint32_t table_size) 167 { 168 if (table_size < QED_MIN_TABLE_SIZE || 169 table_size > QED_MAX_TABLE_SIZE) { 170 return false; 171 } 172 if (table_size & (table_size - 1)) { 173 return false; /* not power of 2 */ 174 } 175 return true; 176 } 177 178 static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size, 179 uint32_t table_size) 180 { 181 if (image_size % BDRV_SECTOR_SIZE != 0) { 182 return false; /* not multiple of sector size */ 183 } 184 if (image_size > qed_max_image_size(cluster_size, table_size)) { 185 return false; /* image is too large */ 186 } 187 return true; 188 } 189 190 /** 191 * Read a string of known length from the image file 192 * 193 * @file: Image file 194 * @offset: File offset to start of string, in bytes 195 * @n: String length in bytes 196 * @buf: Destination buffer 197 * @buflen: Destination buffer length in bytes 198 * @ret: 0 on success, -errno on failure 199 * 200 * The string is NUL-terminated. 201 */ 202 static int qed_read_string(BdrvChild *file, uint64_t offset, size_t n, 203 char *buf, size_t buflen) 204 { 205 int ret; 206 if (n >= buflen) { 207 return -EINVAL; 208 } 209 ret = bdrv_pread(file, offset, buf, n); 210 if (ret < 0) { 211 return ret; 212 } 213 buf[n] = '\0'; 214 return 0; 215 } 216 217 /** 218 * Allocate new clusters 219 * 220 * @s: QED state 221 * @n: Number of contiguous clusters to allocate 222 * @ret: Offset of first allocated cluster 223 * 224 * This function only produces the offset where the new clusters should be 225 * written. It updates BDRVQEDState but does not make any changes to the image 226 * file. 227 * 228 * Called with table_lock held. 229 */ 230 static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n) 231 { 232 uint64_t offset = s->file_size; 233 s->file_size += n * s->header.cluster_size; 234 return offset; 235 } 236 237 QEDTable *qed_alloc_table(BDRVQEDState *s) 238 { 239 /* Honor O_DIRECT memory alignment requirements */ 240 return qemu_blockalign(s->bs, 241 s->header.cluster_size * s->header.table_size); 242 } 243 244 /** 245 * Allocate a new zeroed L2 table 246 * 247 * Called with table_lock held. 248 */ 249 static CachedL2Table *qed_new_l2_table(BDRVQEDState *s) 250 { 251 CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); 252 253 l2_table->table = qed_alloc_table(s); 254 l2_table->offset = qed_alloc_clusters(s, s->header.table_size); 255 256 memset(l2_table->table->offsets, 0, 257 s->header.cluster_size * s->header.table_size); 258 return l2_table; 259 } 260 261 static bool qed_plug_allocating_write_reqs(BDRVQEDState *s) 262 { 263 qemu_co_mutex_lock(&s->table_lock); 264 265 /* No reentrancy is allowed. */ 266 assert(!s->allocating_write_reqs_plugged); 267 if (s->allocating_acb != NULL) { 268 /* Another allocating write came concurrently. This cannot happen 269 * from bdrv_qed_co_drain_begin, but it can happen when the timer runs. 270 */ 271 qemu_co_mutex_unlock(&s->table_lock); 272 return false; 273 } 274 275 s->allocating_write_reqs_plugged = true; 276 qemu_co_mutex_unlock(&s->table_lock); 277 return true; 278 } 279 280 static void qed_unplug_allocating_write_reqs(BDRVQEDState *s) 281 { 282 qemu_co_mutex_lock(&s->table_lock); 283 assert(s->allocating_write_reqs_plugged); 284 s->allocating_write_reqs_plugged = false; 285 qemu_co_queue_next(&s->allocating_write_reqs); 286 qemu_co_mutex_unlock(&s->table_lock); 287 } 288 289 static void coroutine_fn qed_need_check_timer_entry(void *opaque) 290 { 291 BDRVQEDState *s = opaque; 292 int ret; 293 294 trace_qed_need_check_timer_cb(s); 295 296 if (!qed_plug_allocating_write_reqs(s)) { 297 return; 298 } 299 300 /* Ensure writes are on disk before clearing flag */ 301 ret = bdrv_co_flush(s->bs->file->bs); 302 if (ret < 0) { 303 qed_unplug_allocating_write_reqs(s); 304 return; 305 } 306 307 s->header.features &= ~QED_F_NEED_CHECK; 308 ret = qed_write_header(s); 309 (void) ret; 310 311 qed_unplug_allocating_write_reqs(s); 312 313 ret = bdrv_co_flush(s->bs); 314 (void) ret; 315 } 316 317 static void qed_need_check_timer_cb(void *opaque) 318 { 319 Coroutine *co = qemu_coroutine_create(qed_need_check_timer_entry, opaque); 320 qemu_coroutine_enter(co); 321 } 322 323 static void qed_start_need_check_timer(BDRVQEDState *s) 324 { 325 trace_qed_start_need_check_timer(s); 326 327 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for 328 * migration. 329 */ 330 timer_mod(s->need_check_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 331 NANOSECONDS_PER_SECOND * QED_NEED_CHECK_TIMEOUT); 332 } 333 334 /* It's okay to call this multiple times or when no timer is started */ 335 static void qed_cancel_need_check_timer(BDRVQEDState *s) 336 { 337 trace_qed_cancel_need_check_timer(s); 338 timer_del(s->need_check_timer); 339 } 340 341 static void bdrv_qed_detach_aio_context(BlockDriverState *bs) 342 { 343 BDRVQEDState *s = bs->opaque; 344 345 qed_cancel_need_check_timer(s); 346 timer_free(s->need_check_timer); 347 } 348 349 static void bdrv_qed_attach_aio_context(BlockDriverState *bs, 350 AioContext *new_context) 351 { 352 BDRVQEDState *s = bs->opaque; 353 354 s->need_check_timer = aio_timer_new(new_context, 355 QEMU_CLOCK_VIRTUAL, SCALE_NS, 356 qed_need_check_timer_cb, s); 357 if (s->header.features & QED_F_NEED_CHECK) { 358 qed_start_need_check_timer(s); 359 } 360 } 361 362 static void coroutine_fn bdrv_qed_co_drain_begin(BlockDriverState *bs) 363 { 364 BDRVQEDState *s = bs->opaque; 365 366 /* Fire the timer immediately in order to start doing I/O as soon as the 367 * header is flushed. 368 */ 369 if (s->need_check_timer && timer_pending(s->need_check_timer)) { 370 qed_cancel_need_check_timer(s); 371 qed_need_check_timer_entry(s); 372 } 373 } 374 375 static void bdrv_qed_init_state(BlockDriverState *bs) 376 { 377 BDRVQEDState *s = bs->opaque; 378 379 memset(s, 0, sizeof(BDRVQEDState)); 380 s->bs = bs; 381 qemu_co_mutex_init(&s->table_lock); 382 qemu_co_queue_init(&s->allocating_write_reqs); 383 } 384 385 /* Called with table_lock held. */ 386 static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options, 387 int flags, Error **errp) 388 { 389 BDRVQEDState *s = bs->opaque; 390 QEDHeader le_header; 391 int64_t file_size; 392 int ret; 393 394 ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header)); 395 if (ret < 0) { 396 return ret; 397 } 398 qed_header_le_to_cpu(&le_header, &s->header); 399 400 if (s->header.magic != QED_MAGIC) { 401 error_setg(errp, "Image not in QED format"); 402 return -EINVAL; 403 } 404 if (s->header.features & ~QED_FEATURE_MASK) { 405 /* image uses unsupported feature bits */ 406 error_setg(errp, "Unsupported QED features: %" PRIx64, 407 s->header.features & ~QED_FEATURE_MASK); 408 return -ENOTSUP; 409 } 410 if (!qed_is_cluster_size_valid(s->header.cluster_size)) { 411 return -EINVAL; 412 } 413 414 /* Round down file size to the last cluster */ 415 file_size = bdrv_getlength(bs->file->bs); 416 if (file_size < 0) { 417 return file_size; 418 } 419 s->file_size = qed_start_of_cluster(s, file_size); 420 421 if (!qed_is_table_size_valid(s->header.table_size)) { 422 return -EINVAL; 423 } 424 if (!qed_is_image_size_valid(s->header.image_size, 425 s->header.cluster_size, 426 s->header.table_size)) { 427 return -EINVAL; 428 } 429 if (!qed_check_table_offset(s, s->header.l1_table_offset)) { 430 return -EINVAL; 431 } 432 433 s->table_nelems = (s->header.cluster_size * s->header.table_size) / 434 sizeof(uint64_t); 435 s->l2_shift = ctz32(s->header.cluster_size); 436 s->l2_mask = s->table_nelems - 1; 437 s->l1_shift = s->l2_shift + ctz32(s->table_nelems); 438 439 /* Header size calculation must not overflow uint32_t */ 440 if (s->header.header_size > UINT32_MAX / s->header.cluster_size) { 441 return -EINVAL; 442 } 443 444 if ((s->header.features & QED_F_BACKING_FILE)) { 445 if ((uint64_t)s->header.backing_filename_offset + 446 s->header.backing_filename_size > 447 s->header.cluster_size * s->header.header_size) { 448 return -EINVAL; 449 } 450 451 ret = qed_read_string(bs->file, s->header.backing_filename_offset, 452 s->header.backing_filename_size, 453 bs->auto_backing_file, 454 sizeof(bs->auto_backing_file)); 455 if (ret < 0) { 456 return ret; 457 } 458 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 459 bs->auto_backing_file); 460 461 if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) { 462 pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw"); 463 } 464 } 465 466 /* Reset unknown autoclear feature bits. This is a backwards 467 * compatibility mechanism that allows images to be opened by older 468 * programs, which "knock out" unknown feature bits. When an image is 469 * opened by a newer program again it can detect that the autoclear 470 * feature is no longer valid. 471 */ 472 if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 && 473 !bdrv_is_read_only(bs->file->bs) && !(flags & BDRV_O_INACTIVE)) { 474 s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK; 475 476 ret = qed_write_header_sync(s); 477 if (ret) { 478 return ret; 479 } 480 481 /* From here on only known autoclear feature bits are valid */ 482 bdrv_flush(bs->file->bs); 483 } 484 485 s->l1_table = qed_alloc_table(s); 486 qed_init_l2_cache(&s->l2_cache); 487 488 ret = qed_read_l1_table_sync(s); 489 if (ret) { 490 goto out; 491 } 492 493 /* If image was not closed cleanly, check consistency */ 494 if (!(flags & BDRV_O_CHECK) && (s->header.features & QED_F_NEED_CHECK)) { 495 /* Read-only images cannot be fixed. There is no risk of corruption 496 * since write operations are not possible. Therefore, allow 497 * potentially inconsistent images to be opened read-only. This can 498 * aid data recovery from an otherwise inconsistent image. 499 */ 500 if (!bdrv_is_read_only(bs->file->bs) && 501 !(flags & BDRV_O_INACTIVE)) { 502 BdrvCheckResult result = {0}; 503 504 ret = qed_check(s, &result, true); 505 if (ret) { 506 goto out; 507 } 508 } 509 } 510 511 bdrv_qed_attach_aio_context(bs, bdrv_get_aio_context(bs)); 512 513 out: 514 if (ret) { 515 qed_free_l2_cache(&s->l2_cache); 516 qemu_vfree(s->l1_table); 517 } 518 return ret; 519 } 520 521 typedef struct QEDOpenCo { 522 BlockDriverState *bs; 523 QDict *options; 524 int flags; 525 Error **errp; 526 int ret; 527 } QEDOpenCo; 528 529 static void coroutine_fn bdrv_qed_open_entry(void *opaque) 530 { 531 QEDOpenCo *qoc = opaque; 532 BDRVQEDState *s = qoc->bs->opaque; 533 534 qemu_co_mutex_lock(&s->table_lock); 535 qoc->ret = bdrv_qed_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp); 536 qemu_co_mutex_unlock(&s->table_lock); 537 } 538 539 static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags, 540 Error **errp) 541 { 542 QEDOpenCo qoc = { 543 .bs = bs, 544 .options = options, 545 .flags = flags, 546 .errp = errp, 547 .ret = -EINPROGRESS 548 }; 549 550 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds, 551 BDRV_CHILD_IMAGE, 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_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 655 errp); 656 if (!blk) { 657 ret = -EPERM; 658 goto out; 659 } 660 blk_set_allow_write_beyond_eof(blk, true); 661 662 /* Prepare image format */ 663 header = (QEDHeader) { 664 .magic = QED_MAGIC, 665 .cluster_size = qed_opts->cluster_size, 666 .table_size = qed_opts->table_size, 667 .header_size = 1, 668 .features = 0, 669 .compat_features = 0, 670 .l1_table_offset = qed_opts->cluster_size, 671 .image_size = qed_opts->size, 672 }; 673 674 l1_size = header.cluster_size * header.table_size; 675 676 /* 677 * The QED format associates file length with allocation status, 678 * so a new file (which is empty) must have a length of 0. 679 */ 680 ret = blk_truncate(blk, 0, true, PREALLOC_MODE_OFF, 0, errp); 681 if (ret < 0) { 682 goto out; 683 } 684 685 if (qed_opts->has_backing_file) { 686 header.features |= QED_F_BACKING_FILE; 687 header.backing_filename_offset = sizeof(le_header); 688 header.backing_filename_size = strlen(qed_opts->backing_file); 689 690 if (qed_opts->has_backing_fmt) { 691 const char *backing_fmt = BlockdevDriver_str(qed_opts->backing_fmt); 692 if (qed_fmt_is_raw(backing_fmt)) { 693 header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 694 } 695 } 696 } 697 698 qed_header_cpu_to_le(&header, &le_header); 699 ret = blk_pwrite(blk, 0, &le_header, sizeof(le_header), 0); 700 if (ret < 0) { 701 goto out; 702 } 703 ret = blk_pwrite(blk, sizeof(le_header), qed_opts->backing_file, 704 header.backing_filename_size, 0); 705 if (ret < 0) { 706 goto out; 707 } 708 709 l1_table = g_malloc0(l1_size); 710 ret = blk_pwrite(blk, header.l1_table_offset, l1_table, l1_size, 0); 711 if (ret < 0) { 712 goto out; 713 } 714 715 ret = 0; /* success */ 716 out: 717 g_free(l1_table); 718 blk_unref(blk); 719 bdrv_unref(bs); 720 return ret; 721 } 722 723 static int coroutine_fn bdrv_qed_co_create_opts(BlockDriver *drv, 724 const char *filename, 725 QemuOpts *opts, 726 Error **errp) 727 { 728 BlockdevCreateOptions *create_options = NULL; 729 QDict *qdict; 730 Visitor *v; 731 BlockDriverState *bs = NULL; 732 Error *local_err = NULL; 733 int ret; 734 735 static const QDictRenames opt_renames[] = { 736 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 737 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 738 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 739 { BLOCK_OPT_TABLE_SIZE, "table-size" }, 740 { NULL, NULL }, 741 }; 742 743 /* Parse options and convert legacy syntax */ 744 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qed_create_opts, true); 745 746 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 747 ret = -EINVAL; 748 goto fail; 749 } 750 751 /* Create and open the file (protocol layer) */ 752 ret = bdrv_create_file(filename, opts, &local_err); 753 if (ret < 0) { 754 error_propagate(errp, local_err); 755 goto fail; 756 } 757 758 bs = bdrv_open(filename, NULL, NULL, 759 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 760 if (bs == NULL) { 761 ret = -EIO; 762 goto fail; 763 } 764 765 /* Now get the QAPI type BlockdevCreateOptions */ 766 qdict_put_str(qdict, "driver", "qed"); 767 qdict_put_str(qdict, "file", bs->node_name); 768 769 v = qobject_input_visitor_new_flat_confused(qdict, errp); 770 if (!v) { 771 ret = -EINVAL; 772 goto fail; 773 } 774 775 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); 776 visit_free(v); 777 778 if (local_err) { 779 error_propagate(errp, local_err); 780 ret = -EINVAL; 781 goto fail; 782 } 783 784 /* Silently round up size */ 785 assert(create_options->driver == BLOCKDEV_DRIVER_QED); 786 create_options->u.qed.size = 787 ROUND_UP(create_options->u.qed.size, BDRV_SECTOR_SIZE); 788 789 /* Create the qed image (format layer) */ 790 ret = bdrv_qed_co_create(create_options, errp); 791 792 fail: 793 qobject_unref(qdict); 794 bdrv_unref(bs); 795 qapi_free_BlockdevCreateOptions(create_options); 796 return ret; 797 } 798 799 static int coroutine_fn bdrv_qed_co_block_status(BlockDriverState *bs, 800 bool want_zero, 801 int64_t pos, int64_t bytes, 802 int64_t *pnum, int64_t *map, 803 BlockDriverState **file) 804 { 805 BDRVQEDState *s = bs->opaque; 806 size_t len = MIN(bytes, SIZE_MAX); 807 int status; 808 QEDRequest request = { .l2_table = NULL }; 809 uint64_t offset; 810 int ret; 811 812 qemu_co_mutex_lock(&s->table_lock); 813 ret = qed_find_cluster(s, &request, pos, &len, &offset); 814 815 *pnum = len; 816 switch (ret) { 817 case QED_CLUSTER_FOUND: 818 *map = offset | qed_offset_into_cluster(s, pos); 819 status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 820 *file = bs->file->bs; 821 break; 822 case QED_CLUSTER_ZERO: 823 status = BDRV_BLOCK_ZERO; 824 break; 825 case QED_CLUSTER_L2: 826 case QED_CLUSTER_L1: 827 status = 0; 828 break; 829 default: 830 assert(ret < 0); 831 status = ret; 832 break; 833 } 834 835 qed_unref_l2_cache_entry(request.l2_table); 836 qemu_co_mutex_unlock(&s->table_lock); 837 838 return status; 839 } 840 841 static BDRVQEDState *acb_to_s(QEDAIOCB *acb) 842 { 843 return acb->bs->opaque; 844 } 845 846 /** 847 * Read from the backing file or zero-fill if no backing file 848 * 849 * @s: QED state 850 * @pos: Byte position in device 851 * @qiov: Destination I/O vector 852 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here 853 * @cb: Completion function 854 * @opaque: User data for completion function 855 * 856 * This function reads qiov->size bytes starting at pos from the backing file. 857 * If there is no backing file then zeroes are read. 858 */ 859 static int coroutine_fn qed_read_backing_file(BDRVQEDState *s, uint64_t pos, 860 QEMUIOVector *qiov, 861 QEMUIOVector **backing_qiov) 862 { 863 uint64_t backing_length = 0; 864 size_t size; 865 int ret; 866 867 /* If there is a backing file, get its length. Treat the absence of a 868 * backing file like a zero length backing file. 869 */ 870 if (s->bs->backing) { 871 int64_t l = bdrv_getlength(s->bs->backing->bs); 872 if (l < 0) { 873 return l; 874 } 875 backing_length = l; 876 } 877 878 /* Zero all sectors if reading beyond the end of the backing file */ 879 if (pos >= backing_length || 880 pos + qiov->size > backing_length) { 881 qemu_iovec_memset(qiov, 0, 0, qiov->size); 882 } 883 884 /* Complete now if there are no backing file sectors to read */ 885 if (pos >= backing_length) { 886 return 0; 887 } 888 889 /* If the read straddles the end of the backing file, shorten it */ 890 size = MIN((uint64_t)backing_length - pos, qiov->size); 891 892 assert(*backing_qiov == NULL); 893 *backing_qiov = g_new(QEMUIOVector, 1); 894 qemu_iovec_init(*backing_qiov, qiov->niov); 895 qemu_iovec_concat(*backing_qiov, qiov, 0, size); 896 897 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); 898 ret = bdrv_co_preadv(s->bs->backing, pos, size, *backing_qiov, 0); 899 if (ret < 0) { 900 return ret; 901 } 902 return 0; 903 } 904 905 /** 906 * Copy data from backing file into the image 907 * 908 * @s: QED state 909 * @pos: Byte position in device 910 * @len: Number of bytes 911 * @offset: Byte offset in image file 912 */ 913 static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s, 914 uint64_t pos, uint64_t len, 915 uint64_t offset) 916 { 917 QEMUIOVector qiov; 918 QEMUIOVector *backing_qiov = NULL; 919 int ret; 920 921 /* Skip copy entirely if there is no work to do */ 922 if (len == 0) { 923 return 0; 924 } 925 926 qemu_iovec_init_buf(&qiov, qemu_blockalign(s->bs, len), len); 927 928 ret = qed_read_backing_file(s, pos, &qiov, &backing_qiov); 929 930 if (backing_qiov) { 931 qemu_iovec_destroy(backing_qiov); 932 g_free(backing_qiov); 933 backing_qiov = NULL; 934 } 935 936 if (ret) { 937 goto out; 938 } 939 940 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); 941 ret = bdrv_co_pwritev(s->bs->file, offset, qiov.size, &qiov, 0); 942 if (ret < 0) { 943 goto out; 944 } 945 ret = 0; 946 out: 947 qemu_vfree(qemu_iovec_buf(&qiov)); 948 return ret; 949 } 950 951 /** 952 * Link one or more contiguous clusters into a table 953 * 954 * @s: QED state 955 * @table: L2 table 956 * @index: First cluster index 957 * @n: Number of contiguous clusters 958 * @cluster: First cluster offset 959 * 960 * The cluster offset may be an allocated byte offset in the image file, the 961 * zero cluster marker, or the unallocated cluster marker. 962 * 963 * Called with table_lock held. 964 */ 965 static void coroutine_fn qed_update_l2_table(BDRVQEDState *s, QEDTable *table, 966 int index, unsigned int n, 967 uint64_t cluster) 968 { 969 int i; 970 for (i = index; i < index + n; i++) { 971 table->offsets[i] = cluster; 972 if (!qed_offset_is_unalloc_cluster(cluster) && 973 !qed_offset_is_zero_cluster(cluster)) { 974 cluster += s->header.cluster_size; 975 } 976 } 977 } 978 979 /* Called with table_lock held. */ 980 static void coroutine_fn qed_aio_complete(QEDAIOCB *acb) 981 { 982 BDRVQEDState *s = acb_to_s(acb); 983 984 /* Free resources */ 985 qemu_iovec_destroy(&acb->cur_qiov); 986 qed_unref_l2_cache_entry(acb->request.l2_table); 987 988 /* Free the buffer we may have allocated for zero writes */ 989 if (acb->flags & QED_AIOCB_ZERO) { 990 qemu_vfree(acb->qiov->iov[0].iov_base); 991 acb->qiov->iov[0].iov_base = NULL; 992 } 993 994 /* Start next allocating write request waiting behind this one. Note that 995 * requests enqueue themselves when they first hit an unallocated cluster 996 * but they wait until the entire request is finished before waking up the 997 * next request in the queue. This ensures that we don't cycle through 998 * requests multiple times but rather finish one at a time completely. 999 */ 1000 if (acb == s->allocating_acb) { 1001 s->allocating_acb = NULL; 1002 if (!qemu_co_queue_empty(&s->allocating_write_reqs)) { 1003 qemu_co_queue_next(&s->allocating_write_reqs); 1004 } else if (s->header.features & QED_F_NEED_CHECK) { 1005 qed_start_need_check_timer(s); 1006 } 1007 } 1008 } 1009 1010 /** 1011 * Update L1 table with new L2 table offset and write it out 1012 * 1013 * Called with table_lock held. 1014 */ 1015 static int coroutine_fn qed_aio_write_l1_update(QEDAIOCB *acb) 1016 { 1017 BDRVQEDState *s = acb_to_s(acb); 1018 CachedL2Table *l2_table = acb->request.l2_table; 1019 uint64_t l2_offset = l2_table->offset; 1020 int index, ret; 1021 1022 index = qed_l1_index(s, acb->cur_pos); 1023 s->l1_table->offsets[index] = l2_table->offset; 1024 1025 ret = qed_write_l1_table(s, index, 1); 1026 1027 /* Commit the current L2 table to the cache */ 1028 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 1029 1030 /* This is guaranteed to succeed because we just committed the entry to the 1031 * cache. 1032 */ 1033 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 1034 assert(acb->request.l2_table != NULL); 1035 1036 return ret; 1037 } 1038 1039 1040 /** 1041 * Update L2 table with new cluster offsets and write them out 1042 * 1043 * Called with table_lock held. 1044 */ 1045 static int coroutine_fn qed_aio_write_l2_update(QEDAIOCB *acb, uint64_t offset) 1046 { 1047 BDRVQEDState *s = acb_to_s(acb); 1048 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1; 1049 int index, ret; 1050 1051 if (need_alloc) { 1052 qed_unref_l2_cache_entry(acb->request.l2_table); 1053 acb->request.l2_table = qed_new_l2_table(s); 1054 } 1055 1056 index = qed_l2_index(s, acb->cur_pos); 1057 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, 1058 offset); 1059 1060 if (need_alloc) { 1061 /* Write out the whole new L2 table */ 1062 ret = qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true); 1063 if (ret) { 1064 return ret; 1065 } 1066 return qed_aio_write_l1_update(acb); 1067 } else { 1068 /* Write out only the updated part of the L2 table */ 1069 ret = qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, 1070 false); 1071 if (ret) { 1072 return ret; 1073 } 1074 } 1075 return 0; 1076 } 1077 1078 /** 1079 * Write data to the image file 1080 * 1081 * Called with table_lock *not* held. 1082 */ 1083 static int coroutine_fn qed_aio_write_main(QEDAIOCB *acb) 1084 { 1085 BDRVQEDState *s = acb_to_s(acb); 1086 uint64_t offset = acb->cur_cluster + 1087 qed_offset_into_cluster(s, acb->cur_pos); 1088 1089 trace_qed_aio_write_main(s, acb, 0, offset, acb->cur_qiov.size); 1090 1091 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); 1092 return bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size, 1093 &acb->cur_qiov, 0); 1094 } 1095 1096 /** 1097 * Populate untouched regions of new data cluster 1098 * 1099 * Called with table_lock held. 1100 */ 1101 static int coroutine_fn qed_aio_write_cow(QEDAIOCB *acb) 1102 { 1103 BDRVQEDState *s = acb_to_s(acb); 1104 uint64_t start, len, offset; 1105 int ret; 1106 1107 qemu_co_mutex_unlock(&s->table_lock); 1108 1109 /* Populate front untouched region of new data cluster */ 1110 start = qed_start_of_cluster(s, acb->cur_pos); 1111 len = qed_offset_into_cluster(s, acb->cur_pos); 1112 1113 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); 1114 ret = qed_copy_from_backing_file(s, start, len, acb->cur_cluster); 1115 if (ret < 0) { 1116 goto out; 1117 } 1118 1119 /* Populate back untouched region of new data cluster */ 1120 start = acb->cur_pos + acb->cur_qiov.size; 1121 len = qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start; 1122 offset = acb->cur_cluster + 1123 qed_offset_into_cluster(s, acb->cur_pos) + 1124 acb->cur_qiov.size; 1125 1126 trace_qed_aio_write_postfill(s, acb, start, len, offset); 1127 ret = qed_copy_from_backing_file(s, start, len, offset); 1128 if (ret < 0) { 1129 goto out; 1130 } 1131 1132 ret = qed_aio_write_main(acb); 1133 if (ret < 0) { 1134 goto out; 1135 } 1136 1137 if (s->bs->backing) { 1138 /* 1139 * Flush new data clusters before updating the L2 table 1140 * 1141 * This flush is necessary when a backing file is in use. A crash 1142 * during an allocating write could result in empty clusters in the 1143 * image. If the write only touched a subregion of the cluster, 1144 * then backing image sectors have been lost in the untouched 1145 * region. The solution is to flush after writing a new data 1146 * cluster and before updating the L2 table. 1147 */ 1148 ret = bdrv_co_flush(s->bs->file->bs); 1149 } 1150 1151 out: 1152 qemu_co_mutex_lock(&s->table_lock); 1153 return ret; 1154 } 1155 1156 /** 1157 * Check if the QED_F_NEED_CHECK bit should be set during allocating write 1158 */ 1159 static bool qed_should_set_need_check(BDRVQEDState *s) 1160 { 1161 /* The flush before L2 update path ensures consistency */ 1162 if (s->bs->backing) { 1163 return false; 1164 } 1165 1166 return !(s->header.features & QED_F_NEED_CHECK); 1167 } 1168 1169 /** 1170 * Write new data cluster 1171 * 1172 * @acb: Write request 1173 * @len: Length in bytes 1174 * 1175 * This path is taken when writing to previously unallocated clusters. 1176 * 1177 * Called with table_lock held. 1178 */ 1179 static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 1180 { 1181 BDRVQEDState *s = acb_to_s(acb); 1182 int ret; 1183 1184 /* Cancel timer when the first allocating request comes in */ 1185 if (s->allocating_acb == NULL) { 1186 qed_cancel_need_check_timer(s); 1187 } 1188 1189 /* Freeze this request if another allocating write is in progress */ 1190 if (s->allocating_acb != acb || s->allocating_write_reqs_plugged) { 1191 if (s->allocating_acb != NULL) { 1192 qemu_co_queue_wait(&s->allocating_write_reqs, &s->table_lock); 1193 assert(s->allocating_acb == NULL); 1194 } 1195 s->allocating_acb = acb; 1196 return -EAGAIN; /* start over with looking up table entries */ 1197 } 1198 1199 acb->cur_nclusters = qed_bytes_to_clusters(s, 1200 qed_offset_into_cluster(s, acb->cur_pos) + len); 1201 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1202 1203 if (acb->flags & QED_AIOCB_ZERO) { 1204 /* Skip ahead if the clusters are already zero */ 1205 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) { 1206 return 0; 1207 } 1208 acb->cur_cluster = 1; 1209 } else { 1210 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); 1211 } 1212 1213 if (qed_should_set_need_check(s)) { 1214 s->header.features |= QED_F_NEED_CHECK; 1215 ret = qed_write_header(s); 1216 if (ret < 0) { 1217 return ret; 1218 } 1219 } 1220 1221 if (!(acb->flags & QED_AIOCB_ZERO)) { 1222 ret = qed_aio_write_cow(acb); 1223 if (ret < 0) { 1224 return ret; 1225 } 1226 } 1227 1228 return qed_aio_write_l2_update(acb, acb->cur_cluster); 1229 } 1230 1231 /** 1232 * Write data cluster in place 1233 * 1234 * @acb: Write request 1235 * @offset: Cluster offset in bytes 1236 * @len: Length in bytes 1237 * 1238 * This path is taken when writing to already allocated clusters. 1239 * 1240 * Called with table_lock held. 1241 */ 1242 static int coroutine_fn qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, 1243 size_t len) 1244 { 1245 BDRVQEDState *s = acb_to_s(acb); 1246 int r; 1247 1248 qemu_co_mutex_unlock(&s->table_lock); 1249 1250 /* Allocate buffer for zero writes */ 1251 if (acb->flags & QED_AIOCB_ZERO) { 1252 struct iovec *iov = acb->qiov->iov; 1253 1254 if (!iov->iov_base) { 1255 iov->iov_base = qemu_try_blockalign(acb->bs, iov->iov_len); 1256 if (iov->iov_base == NULL) { 1257 r = -ENOMEM; 1258 goto out; 1259 } 1260 memset(iov->iov_base, 0, iov->iov_len); 1261 } 1262 } 1263 1264 /* Calculate the I/O vector */ 1265 acb->cur_cluster = offset; 1266 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1267 1268 /* Do the actual write. */ 1269 r = qed_aio_write_main(acb); 1270 out: 1271 qemu_co_mutex_lock(&s->table_lock); 1272 return r; 1273 } 1274 1275 /** 1276 * Write data cluster 1277 * 1278 * @opaque: Write request 1279 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1280 * @offset: Cluster offset in bytes 1281 * @len: Length in bytes 1282 * 1283 * Called with table_lock held. 1284 */ 1285 static int coroutine_fn qed_aio_write_data(void *opaque, int ret, 1286 uint64_t offset, size_t len) 1287 { 1288 QEDAIOCB *acb = opaque; 1289 1290 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); 1291 1292 acb->find_cluster_ret = ret; 1293 1294 switch (ret) { 1295 case QED_CLUSTER_FOUND: 1296 return qed_aio_write_inplace(acb, offset, len); 1297 1298 case QED_CLUSTER_L2: 1299 case QED_CLUSTER_L1: 1300 case QED_CLUSTER_ZERO: 1301 return qed_aio_write_alloc(acb, len); 1302 1303 default: 1304 g_assert_not_reached(); 1305 } 1306 } 1307 1308 /** 1309 * Read data cluster 1310 * 1311 * @opaque: Read request 1312 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1313 * @offset: Cluster offset in bytes 1314 * @len: Length in bytes 1315 * 1316 * Called with table_lock held. 1317 */ 1318 static int coroutine_fn qed_aio_read_data(void *opaque, int ret, 1319 uint64_t offset, size_t len) 1320 { 1321 QEDAIOCB *acb = opaque; 1322 BDRVQEDState *s = acb_to_s(acb); 1323 BlockDriverState *bs = acb->bs; 1324 int r; 1325 1326 qemu_co_mutex_unlock(&s->table_lock); 1327 1328 /* Adjust offset into cluster */ 1329 offset += qed_offset_into_cluster(s, acb->cur_pos); 1330 1331 trace_qed_aio_read_data(s, acb, ret, offset, len); 1332 1333 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1334 1335 /* Handle zero cluster and backing file reads, otherwise read 1336 * data cluster directly. 1337 */ 1338 if (ret == QED_CLUSTER_ZERO) { 1339 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size); 1340 r = 0; 1341 } else if (ret != QED_CLUSTER_FOUND) { 1342 r = qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov, 1343 &acb->backing_qiov); 1344 } else { 1345 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 1346 r = bdrv_co_preadv(bs->file, offset, acb->cur_qiov.size, 1347 &acb->cur_qiov, 0); 1348 } 1349 1350 qemu_co_mutex_lock(&s->table_lock); 1351 return r; 1352 } 1353 1354 /** 1355 * Begin next I/O or complete the request 1356 */ 1357 static int coroutine_fn qed_aio_next_io(QEDAIOCB *acb) 1358 { 1359 BDRVQEDState *s = acb_to_s(acb); 1360 uint64_t offset; 1361 size_t len; 1362 int ret; 1363 1364 qemu_co_mutex_lock(&s->table_lock); 1365 while (1) { 1366 trace_qed_aio_next_io(s, acb, 0, acb->cur_pos + acb->cur_qiov.size); 1367 1368 if (acb->backing_qiov) { 1369 qemu_iovec_destroy(acb->backing_qiov); 1370 g_free(acb->backing_qiov); 1371 acb->backing_qiov = NULL; 1372 } 1373 1374 acb->qiov_offset += acb->cur_qiov.size; 1375 acb->cur_pos += acb->cur_qiov.size; 1376 qemu_iovec_reset(&acb->cur_qiov); 1377 1378 /* Complete request */ 1379 if (acb->cur_pos >= acb->end_pos) { 1380 ret = 0; 1381 break; 1382 } 1383 1384 /* Find next cluster and start I/O */ 1385 len = acb->end_pos - acb->cur_pos; 1386 ret = qed_find_cluster(s, &acb->request, acb->cur_pos, &len, &offset); 1387 if (ret < 0) { 1388 break; 1389 } 1390 1391 if (acb->flags & QED_AIOCB_WRITE) { 1392 ret = qed_aio_write_data(acb, ret, offset, len); 1393 } else { 1394 ret = qed_aio_read_data(acb, ret, offset, len); 1395 } 1396 1397 if (ret < 0 && ret != -EAGAIN) { 1398 break; 1399 } 1400 } 1401 1402 trace_qed_aio_complete(s, acb, ret); 1403 qed_aio_complete(acb); 1404 qemu_co_mutex_unlock(&s->table_lock); 1405 return ret; 1406 } 1407 1408 static int coroutine_fn qed_co_request(BlockDriverState *bs, int64_t sector_num, 1409 QEMUIOVector *qiov, int nb_sectors, 1410 int flags) 1411 { 1412 QEDAIOCB acb = { 1413 .bs = bs, 1414 .cur_pos = (uint64_t) sector_num * BDRV_SECTOR_SIZE, 1415 .end_pos = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE, 1416 .qiov = qiov, 1417 .flags = flags, 1418 }; 1419 qemu_iovec_init(&acb.cur_qiov, qiov->niov); 1420 1421 trace_qed_aio_setup(bs->opaque, &acb, sector_num, nb_sectors, NULL, flags); 1422 1423 /* Start request */ 1424 return qed_aio_next_io(&acb); 1425 } 1426 1427 static int coroutine_fn bdrv_qed_co_readv(BlockDriverState *bs, 1428 int64_t sector_num, int nb_sectors, 1429 QEMUIOVector *qiov) 1430 { 1431 return qed_co_request(bs, sector_num, qiov, nb_sectors, 0); 1432 } 1433 1434 static int coroutine_fn bdrv_qed_co_writev(BlockDriverState *bs, 1435 int64_t sector_num, int nb_sectors, 1436 QEMUIOVector *qiov, int flags) 1437 { 1438 assert(!flags); 1439 return qed_co_request(bs, sector_num, qiov, nb_sectors, QED_AIOCB_WRITE); 1440 } 1441 1442 static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs, 1443 int64_t offset, 1444 int bytes, 1445 BdrvRequestFlags flags) 1446 { 1447 BDRVQEDState *s = bs->opaque; 1448 1449 /* 1450 * Zero writes start without an I/O buffer. If a buffer becomes necessary 1451 * then it will be allocated during request processing. 1452 */ 1453 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes); 1454 1455 /* Fall back if the request is not aligned */ 1456 if (qed_offset_into_cluster(s, offset) || 1457 qed_offset_into_cluster(s, bytes)) { 1458 return -ENOTSUP; 1459 } 1460 1461 return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov, 1462 bytes >> BDRV_SECTOR_BITS, 1463 QED_AIOCB_WRITE | QED_AIOCB_ZERO); 1464 } 1465 1466 static int coroutine_fn bdrv_qed_co_truncate(BlockDriverState *bs, 1467 int64_t offset, 1468 bool exact, 1469 PreallocMode prealloc, 1470 BdrvRequestFlags flags, 1471 Error **errp) 1472 { 1473 BDRVQEDState *s = bs->opaque; 1474 uint64_t old_image_size; 1475 int ret; 1476 1477 if (prealloc != PREALLOC_MODE_OFF) { 1478 error_setg(errp, "Unsupported preallocation mode '%s'", 1479 PreallocMode_str(prealloc)); 1480 return -ENOTSUP; 1481 } 1482 1483 if (!qed_is_image_size_valid(offset, s->header.cluster_size, 1484 s->header.table_size)) { 1485 error_setg(errp, "Invalid image size specified"); 1486 return -EINVAL; 1487 } 1488 1489 if ((uint64_t)offset < s->header.image_size) { 1490 error_setg(errp, "Shrinking images is currently not supported"); 1491 return -ENOTSUP; 1492 } 1493 1494 old_image_size = s->header.image_size; 1495 s->header.image_size = offset; 1496 ret = qed_write_header_sync(s); 1497 if (ret < 0) { 1498 s->header.image_size = old_image_size; 1499 error_setg_errno(errp, -ret, "Failed to update the image size"); 1500 } 1501 return ret; 1502 } 1503 1504 static int64_t bdrv_qed_getlength(BlockDriverState *bs) 1505 { 1506 BDRVQEDState *s = bs->opaque; 1507 return s->header.image_size; 1508 } 1509 1510 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1511 { 1512 BDRVQEDState *s = bs->opaque; 1513 1514 memset(bdi, 0, sizeof(*bdi)); 1515 bdi->cluster_size = s->header.cluster_size; 1516 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK; 1517 bdi->unallocated_blocks_are_zero = true; 1518 return 0; 1519 } 1520 1521 static int bdrv_qed_change_backing_file(BlockDriverState *bs, 1522 const char *backing_file, 1523 const char *backing_fmt) 1524 { 1525 BDRVQEDState *s = bs->opaque; 1526 QEDHeader new_header, le_header; 1527 void *buffer; 1528 size_t buffer_len, backing_file_len; 1529 int ret; 1530 1531 /* Refuse to set backing filename if unknown compat feature bits are 1532 * active. If the image uses an unknown compat feature then we may not 1533 * know the layout of data following the header structure and cannot safely 1534 * add a new string. 1535 */ 1536 if (backing_file && (s->header.compat_features & 1537 ~QED_COMPAT_FEATURE_MASK)) { 1538 return -ENOTSUP; 1539 } 1540 1541 memcpy(&new_header, &s->header, sizeof(new_header)); 1542 1543 new_header.features &= ~(QED_F_BACKING_FILE | 1544 QED_F_BACKING_FORMAT_NO_PROBE); 1545 1546 /* Adjust feature flags */ 1547 if (backing_file) { 1548 new_header.features |= QED_F_BACKING_FILE; 1549 1550 if (qed_fmt_is_raw(backing_fmt)) { 1551 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 1552 } 1553 } 1554 1555 /* Calculate new header size */ 1556 backing_file_len = 0; 1557 1558 if (backing_file) { 1559 backing_file_len = strlen(backing_file); 1560 } 1561 1562 buffer_len = sizeof(new_header); 1563 new_header.backing_filename_offset = buffer_len; 1564 new_header.backing_filename_size = backing_file_len; 1565 buffer_len += backing_file_len; 1566 1567 /* Make sure we can rewrite header without failing */ 1568 if (buffer_len > new_header.header_size * new_header.cluster_size) { 1569 return -ENOSPC; 1570 } 1571 1572 /* Prepare new header */ 1573 buffer = g_malloc(buffer_len); 1574 1575 qed_header_cpu_to_le(&new_header, &le_header); 1576 memcpy(buffer, &le_header, sizeof(le_header)); 1577 buffer_len = sizeof(le_header); 1578 1579 if (backing_file) { 1580 memcpy(buffer + buffer_len, backing_file, backing_file_len); 1581 buffer_len += backing_file_len; 1582 } 1583 1584 /* Write new header */ 1585 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len); 1586 g_free(buffer); 1587 if (ret == 0) { 1588 memcpy(&s->header, &new_header, sizeof(new_header)); 1589 } 1590 return ret; 1591 } 1592 1593 static void coroutine_fn bdrv_qed_co_invalidate_cache(BlockDriverState *bs, 1594 Error **errp) 1595 { 1596 BDRVQEDState *s = bs->opaque; 1597 Error *local_err = NULL; 1598 int ret; 1599 1600 bdrv_qed_close(bs); 1601 1602 bdrv_qed_init_state(bs); 1603 qemu_co_mutex_lock(&s->table_lock); 1604 ret = bdrv_qed_do_open(bs, NULL, bs->open_flags, &local_err); 1605 qemu_co_mutex_unlock(&s->table_lock); 1606 if (local_err) { 1607 error_propagate_prepend(errp, local_err, 1608 "Could not reopen qed layer: "); 1609 return; 1610 } else if (ret < 0) { 1611 error_setg_errno(errp, -ret, "Could not reopen qed layer"); 1612 return; 1613 } 1614 } 1615 1616 static int coroutine_fn bdrv_qed_co_check(BlockDriverState *bs, 1617 BdrvCheckResult *result, 1618 BdrvCheckMode fix) 1619 { 1620 BDRVQEDState *s = bs->opaque; 1621 int ret; 1622 1623 qemu_co_mutex_lock(&s->table_lock); 1624 ret = qed_check(s, result, !!fix); 1625 qemu_co_mutex_unlock(&s->table_lock); 1626 1627 return ret; 1628 } 1629 1630 static QemuOptsList qed_create_opts = { 1631 .name = "qed-create-opts", 1632 .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head), 1633 .desc = { 1634 { 1635 .name = BLOCK_OPT_SIZE, 1636 .type = QEMU_OPT_SIZE, 1637 .help = "Virtual disk size" 1638 }, 1639 { 1640 .name = BLOCK_OPT_BACKING_FILE, 1641 .type = QEMU_OPT_STRING, 1642 .help = "File name of a base image" 1643 }, 1644 { 1645 .name = BLOCK_OPT_BACKING_FMT, 1646 .type = QEMU_OPT_STRING, 1647 .help = "Image format of the base image" 1648 }, 1649 { 1650 .name = BLOCK_OPT_CLUSTER_SIZE, 1651 .type = QEMU_OPT_SIZE, 1652 .help = "Cluster size (in bytes)", 1653 .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE) 1654 }, 1655 { 1656 .name = BLOCK_OPT_TABLE_SIZE, 1657 .type = QEMU_OPT_SIZE, 1658 .help = "L1/L2 table size (in clusters)" 1659 }, 1660 { /* end of list */ } 1661 } 1662 }; 1663 1664 static BlockDriver bdrv_qed = { 1665 .format_name = "qed", 1666 .instance_size = sizeof(BDRVQEDState), 1667 .create_opts = &qed_create_opts, 1668 .is_format = true, 1669 .supports_backing = true, 1670 1671 .bdrv_probe = bdrv_qed_probe, 1672 .bdrv_open = bdrv_qed_open, 1673 .bdrv_close = bdrv_qed_close, 1674 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare, 1675 .bdrv_child_perm = bdrv_default_perms, 1676 .bdrv_co_create = bdrv_qed_co_create, 1677 .bdrv_co_create_opts = bdrv_qed_co_create_opts, 1678 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1679 .bdrv_co_block_status = bdrv_qed_co_block_status, 1680 .bdrv_co_readv = bdrv_qed_co_readv, 1681 .bdrv_co_writev = bdrv_qed_co_writev, 1682 .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes, 1683 .bdrv_co_truncate = bdrv_qed_co_truncate, 1684 .bdrv_getlength = bdrv_qed_getlength, 1685 .bdrv_get_info = bdrv_qed_get_info, 1686 .bdrv_refresh_limits = bdrv_qed_refresh_limits, 1687 .bdrv_change_backing_file = bdrv_qed_change_backing_file, 1688 .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache, 1689 .bdrv_co_check = bdrv_qed_co_check, 1690 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context, 1691 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context, 1692 .bdrv_co_drain_begin = bdrv_qed_co_drain_begin, 1693 }; 1694 1695 static void bdrv_qed_init(void) 1696 { 1697 bdrv_register(&bdrv_qed); 1698 } 1699 1700 block_init(bdrv_qed_init); 1701