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 * 853 * This function reads qiov->size bytes starting at pos from the backing file. 854 * If there is no backing file then zeroes are read. 855 */ 856 static int coroutine_fn qed_read_backing_file(BDRVQEDState *s, uint64_t pos, 857 QEMUIOVector *qiov) 858 { 859 if (s->bs->backing) { 860 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); 861 return bdrv_co_preadv(s->bs->backing, pos, qiov->size, qiov, 0); 862 } 863 qemu_iovec_memset(qiov, 0, 0, qiov->size); 864 return 0; 865 } 866 867 /** 868 * Copy data from backing file into the image 869 * 870 * @s: QED state 871 * @pos: Byte position in device 872 * @len: Number of bytes 873 * @offset: Byte offset in image file 874 */ 875 static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s, 876 uint64_t pos, uint64_t len, 877 uint64_t offset) 878 { 879 QEMUIOVector qiov; 880 int ret; 881 882 /* Skip copy entirely if there is no work to do */ 883 if (len == 0) { 884 return 0; 885 } 886 887 qemu_iovec_init_buf(&qiov, qemu_blockalign(s->bs, len), len); 888 889 ret = qed_read_backing_file(s, pos, &qiov); 890 891 if (ret) { 892 goto out; 893 } 894 895 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); 896 ret = bdrv_co_pwritev(s->bs->file, offset, qiov.size, &qiov, 0); 897 if (ret < 0) { 898 goto out; 899 } 900 ret = 0; 901 out: 902 qemu_vfree(qemu_iovec_buf(&qiov)); 903 return ret; 904 } 905 906 /** 907 * Link one or more contiguous clusters into a table 908 * 909 * @s: QED state 910 * @table: L2 table 911 * @index: First cluster index 912 * @n: Number of contiguous clusters 913 * @cluster: First cluster offset 914 * 915 * The cluster offset may be an allocated byte offset in the image file, the 916 * zero cluster marker, or the unallocated cluster marker. 917 * 918 * Called with table_lock held. 919 */ 920 static void coroutine_fn qed_update_l2_table(BDRVQEDState *s, QEDTable *table, 921 int index, unsigned int n, 922 uint64_t cluster) 923 { 924 int i; 925 for (i = index; i < index + n; i++) { 926 table->offsets[i] = cluster; 927 if (!qed_offset_is_unalloc_cluster(cluster) && 928 !qed_offset_is_zero_cluster(cluster)) { 929 cluster += s->header.cluster_size; 930 } 931 } 932 } 933 934 /* Called with table_lock held. */ 935 static void coroutine_fn qed_aio_complete(QEDAIOCB *acb) 936 { 937 BDRVQEDState *s = acb_to_s(acb); 938 939 /* Free resources */ 940 qemu_iovec_destroy(&acb->cur_qiov); 941 qed_unref_l2_cache_entry(acb->request.l2_table); 942 943 /* Free the buffer we may have allocated for zero writes */ 944 if (acb->flags & QED_AIOCB_ZERO) { 945 qemu_vfree(acb->qiov->iov[0].iov_base); 946 acb->qiov->iov[0].iov_base = NULL; 947 } 948 949 /* Start next allocating write request waiting behind this one. Note that 950 * requests enqueue themselves when they first hit an unallocated cluster 951 * but they wait until the entire request is finished before waking up the 952 * next request in the queue. This ensures that we don't cycle through 953 * requests multiple times but rather finish one at a time completely. 954 */ 955 if (acb == s->allocating_acb) { 956 s->allocating_acb = NULL; 957 if (!qemu_co_queue_empty(&s->allocating_write_reqs)) { 958 qemu_co_queue_next(&s->allocating_write_reqs); 959 } else if (s->header.features & QED_F_NEED_CHECK) { 960 qed_start_need_check_timer(s); 961 } 962 } 963 } 964 965 /** 966 * Update L1 table with new L2 table offset and write it out 967 * 968 * Called with table_lock held. 969 */ 970 static int coroutine_fn qed_aio_write_l1_update(QEDAIOCB *acb) 971 { 972 BDRVQEDState *s = acb_to_s(acb); 973 CachedL2Table *l2_table = acb->request.l2_table; 974 uint64_t l2_offset = l2_table->offset; 975 int index, ret; 976 977 index = qed_l1_index(s, acb->cur_pos); 978 s->l1_table->offsets[index] = l2_table->offset; 979 980 ret = qed_write_l1_table(s, index, 1); 981 982 /* Commit the current L2 table to the cache */ 983 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 984 985 /* This is guaranteed to succeed because we just committed the entry to the 986 * cache. 987 */ 988 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 989 assert(acb->request.l2_table != NULL); 990 991 return ret; 992 } 993 994 995 /** 996 * Update L2 table with new cluster offsets and write them out 997 * 998 * Called with table_lock held. 999 */ 1000 static int coroutine_fn qed_aio_write_l2_update(QEDAIOCB *acb, uint64_t offset) 1001 { 1002 BDRVQEDState *s = acb_to_s(acb); 1003 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1; 1004 int index, ret; 1005 1006 if (need_alloc) { 1007 qed_unref_l2_cache_entry(acb->request.l2_table); 1008 acb->request.l2_table = qed_new_l2_table(s); 1009 } 1010 1011 index = qed_l2_index(s, acb->cur_pos); 1012 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, 1013 offset); 1014 1015 if (need_alloc) { 1016 /* Write out the whole new L2 table */ 1017 ret = qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true); 1018 if (ret) { 1019 return ret; 1020 } 1021 return qed_aio_write_l1_update(acb); 1022 } else { 1023 /* Write out only the updated part of the L2 table */ 1024 ret = qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, 1025 false); 1026 if (ret) { 1027 return ret; 1028 } 1029 } 1030 return 0; 1031 } 1032 1033 /** 1034 * Write data to the image file 1035 * 1036 * Called with table_lock *not* held. 1037 */ 1038 static int coroutine_fn qed_aio_write_main(QEDAIOCB *acb) 1039 { 1040 BDRVQEDState *s = acb_to_s(acb); 1041 uint64_t offset = acb->cur_cluster + 1042 qed_offset_into_cluster(s, acb->cur_pos); 1043 1044 trace_qed_aio_write_main(s, acb, 0, offset, acb->cur_qiov.size); 1045 1046 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); 1047 return bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size, 1048 &acb->cur_qiov, 0); 1049 } 1050 1051 /** 1052 * Populate untouched regions of new data cluster 1053 * 1054 * Called with table_lock held. 1055 */ 1056 static int coroutine_fn qed_aio_write_cow(QEDAIOCB *acb) 1057 { 1058 BDRVQEDState *s = acb_to_s(acb); 1059 uint64_t start, len, offset; 1060 int ret; 1061 1062 qemu_co_mutex_unlock(&s->table_lock); 1063 1064 /* Populate front untouched region of new data cluster */ 1065 start = qed_start_of_cluster(s, acb->cur_pos); 1066 len = qed_offset_into_cluster(s, acb->cur_pos); 1067 1068 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); 1069 ret = qed_copy_from_backing_file(s, start, len, acb->cur_cluster); 1070 if (ret < 0) { 1071 goto out; 1072 } 1073 1074 /* Populate back untouched region of new data cluster */ 1075 start = acb->cur_pos + acb->cur_qiov.size; 1076 len = qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start; 1077 offset = acb->cur_cluster + 1078 qed_offset_into_cluster(s, acb->cur_pos) + 1079 acb->cur_qiov.size; 1080 1081 trace_qed_aio_write_postfill(s, acb, start, len, offset); 1082 ret = qed_copy_from_backing_file(s, start, len, offset); 1083 if (ret < 0) { 1084 goto out; 1085 } 1086 1087 ret = qed_aio_write_main(acb); 1088 if (ret < 0) { 1089 goto out; 1090 } 1091 1092 if (s->bs->backing) { 1093 /* 1094 * Flush new data clusters before updating the L2 table 1095 * 1096 * This flush is necessary when a backing file is in use. A crash 1097 * during an allocating write could result in empty clusters in the 1098 * image. If the write only touched a subregion of the cluster, 1099 * then backing image sectors have been lost in the untouched 1100 * region. The solution is to flush after writing a new data 1101 * cluster and before updating the L2 table. 1102 */ 1103 ret = bdrv_co_flush(s->bs->file->bs); 1104 } 1105 1106 out: 1107 qemu_co_mutex_lock(&s->table_lock); 1108 return ret; 1109 } 1110 1111 /** 1112 * Check if the QED_F_NEED_CHECK bit should be set during allocating write 1113 */ 1114 static bool qed_should_set_need_check(BDRVQEDState *s) 1115 { 1116 /* The flush before L2 update path ensures consistency */ 1117 if (s->bs->backing) { 1118 return false; 1119 } 1120 1121 return !(s->header.features & QED_F_NEED_CHECK); 1122 } 1123 1124 /** 1125 * Write new data cluster 1126 * 1127 * @acb: Write request 1128 * @len: Length in bytes 1129 * 1130 * This path is taken when writing to previously unallocated clusters. 1131 * 1132 * Called with table_lock held. 1133 */ 1134 static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 1135 { 1136 BDRVQEDState *s = acb_to_s(acb); 1137 int ret; 1138 1139 /* Cancel timer when the first allocating request comes in */ 1140 if (s->allocating_acb == NULL) { 1141 qed_cancel_need_check_timer(s); 1142 } 1143 1144 /* Freeze this request if another allocating write is in progress */ 1145 if (s->allocating_acb != acb || s->allocating_write_reqs_plugged) { 1146 if (s->allocating_acb != NULL) { 1147 qemu_co_queue_wait(&s->allocating_write_reqs, &s->table_lock); 1148 assert(s->allocating_acb == NULL); 1149 } 1150 s->allocating_acb = acb; 1151 return -EAGAIN; /* start over with looking up table entries */ 1152 } 1153 1154 acb->cur_nclusters = qed_bytes_to_clusters(s, 1155 qed_offset_into_cluster(s, acb->cur_pos) + len); 1156 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1157 1158 if (acb->flags & QED_AIOCB_ZERO) { 1159 /* Skip ahead if the clusters are already zero */ 1160 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) { 1161 return 0; 1162 } 1163 acb->cur_cluster = 1; 1164 } else { 1165 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); 1166 } 1167 1168 if (qed_should_set_need_check(s)) { 1169 s->header.features |= QED_F_NEED_CHECK; 1170 ret = qed_write_header(s); 1171 if (ret < 0) { 1172 return ret; 1173 } 1174 } 1175 1176 if (!(acb->flags & QED_AIOCB_ZERO)) { 1177 ret = qed_aio_write_cow(acb); 1178 if (ret < 0) { 1179 return ret; 1180 } 1181 } 1182 1183 return qed_aio_write_l2_update(acb, acb->cur_cluster); 1184 } 1185 1186 /** 1187 * Write data cluster in place 1188 * 1189 * @acb: Write request 1190 * @offset: Cluster offset in bytes 1191 * @len: Length in bytes 1192 * 1193 * This path is taken when writing to already allocated clusters. 1194 * 1195 * Called with table_lock held. 1196 */ 1197 static int coroutine_fn qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, 1198 size_t len) 1199 { 1200 BDRVQEDState *s = acb_to_s(acb); 1201 int r; 1202 1203 qemu_co_mutex_unlock(&s->table_lock); 1204 1205 /* Allocate buffer for zero writes */ 1206 if (acb->flags & QED_AIOCB_ZERO) { 1207 struct iovec *iov = acb->qiov->iov; 1208 1209 if (!iov->iov_base) { 1210 iov->iov_base = qemu_try_blockalign(acb->bs, iov->iov_len); 1211 if (iov->iov_base == NULL) { 1212 r = -ENOMEM; 1213 goto out; 1214 } 1215 memset(iov->iov_base, 0, iov->iov_len); 1216 } 1217 } 1218 1219 /* Calculate the I/O vector */ 1220 acb->cur_cluster = offset; 1221 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1222 1223 /* Do the actual write. */ 1224 r = qed_aio_write_main(acb); 1225 out: 1226 qemu_co_mutex_lock(&s->table_lock); 1227 return r; 1228 } 1229 1230 /** 1231 * Write data cluster 1232 * 1233 * @opaque: Write request 1234 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1235 * @offset: Cluster offset in bytes 1236 * @len: Length in bytes 1237 * 1238 * Called with table_lock held. 1239 */ 1240 static int coroutine_fn qed_aio_write_data(void *opaque, int ret, 1241 uint64_t offset, size_t len) 1242 { 1243 QEDAIOCB *acb = opaque; 1244 1245 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); 1246 1247 acb->find_cluster_ret = ret; 1248 1249 switch (ret) { 1250 case QED_CLUSTER_FOUND: 1251 return qed_aio_write_inplace(acb, offset, len); 1252 1253 case QED_CLUSTER_L2: 1254 case QED_CLUSTER_L1: 1255 case QED_CLUSTER_ZERO: 1256 return qed_aio_write_alloc(acb, len); 1257 1258 default: 1259 g_assert_not_reached(); 1260 } 1261 } 1262 1263 /** 1264 * Read data cluster 1265 * 1266 * @opaque: Read request 1267 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1268 * @offset: Cluster offset in bytes 1269 * @len: Length in bytes 1270 * 1271 * Called with table_lock held. 1272 */ 1273 static int coroutine_fn qed_aio_read_data(void *opaque, int ret, 1274 uint64_t offset, size_t len) 1275 { 1276 QEDAIOCB *acb = opaque; 1277 BDRVQEDState *s = acb_to_s(acb); 1278 BlockDriverState *bs = acb->bs; 1279 int r; 1280 1281 qemu_co_mutex_unlock(&s->table_lock); 1282 1283 /* Adjust offset into cluster */ 1284 offset += qed_offset_into_cluster(s, acb->cur_pos); 1285 1286 trace_qed_aio_read_data(s, acb, ret, offset, len); 1287 1288 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1289 1290 /* Handle zero cluster and backing file reads, otherwise read 1291 * data cluster directly. 1292 */ 1293 if (ret == QED_CLUSTER_ZERO) { 1294 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size); 1295 r = 0; 1296 } else if (ret != QED_CLUSTER_FOUND) { 1297 r = qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov); 1298 } else { 1299 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 1300 r = bdrv_co_preadv(bs->file, offset, acb->cur_qiov.size, 1301 &acb->cur_qiov, 0); 1302 } 1303 1304 qemu_co_mutex_lock(&s->table_lock); 1305 return r; 1306 } 1307 1308 /** 1309 * Begin next I/O or complete the request 1310 */ 1311 static int coroutine_fn qed_aio_next_io(QEDAIOCB *acb) 1312 { 1313 BDRVQEDState *s = acb_to_s(acb); 1314 uint64_t offset; 1315 size_t len; 1316 int ret; 1317 1318 qemu_co_mutex_lock(&s->table_lock); 1319 while (1) { 1320 trace_qed_aio_next_io(s, acb, 0, acb->cur_pos + acb->cur_qiov.size); 1321 1322 acb->qiov_offset += acb->cur_qiov.size; 1323 acb->cur_pos += acb->cur_qiov.size; 1324 qemu_iovec_reset(&acb->cur_qiov); 1325 1326 /* Complete request */ 1327 if (acb->cur_pos >= acb->end_pos) { 1328 ret = 0; 1329 break; 1330 } 1331 1332 /* Find next cluster and start I/O */ 1333 len = acb->end_pos - acb->cur_pos; 1334 ret = qed_find_cluster(s, &acb->request, acb->cur_pos, &len, &offset); 1335 if (ret < 0) { 1336 break; 1337 } 1338 1339 if (acb->flags & QED_AIOCB_WRITE) { 1340 ret = qed_aio_write_data(acb, ret, offset, len); 1341 } else { 1342 ret = qed_aio_read_data(acb, ret, offset, len); 1343 } 1344 1345 if (ret < 0 && ret != -EAGAIN) { 1346 break; 1347 } 1348 } 1349 1350 trace_qed_aio_complete(s, acb, ret); 1351 qed_aio_complete(acb); 1352 qemu_co_mutex_unlock(&s->table_lock); 1353 return ret; 1354 } 1355 1356 static int coroutine_fn qed_co_request(BlockDriverState *bs, int64_t sector_num, 1357 QEMUIOVector *qiov, int nb_sectors, 1358 int flags) 1359 { 1360 QEDAIOCB acb = { 1361 .bs = bs, 1362 .cur_pos = (uint64_t) sector_num * BDRV_SECTOR_SIZE, 1363 .end_pos = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE, 1364 .qiov = qiov, 1365 .flags = flags, 1366 }; 1367 qemu_iovec_init(&acb.cur_qiov, qiov->niov); 1368 1369 trace_qed_aio_setup(bs->opaque, &acb, sector_num, nb_sectors, NULL, flags); 1370 1371 /* Start request */ 1372 return qed_aio_next_io(&acb); 1373 } 1374 1375 static int coroutine_fn bdrv_qed_co_readv(BlockDriverState *bs, 1376 int64_t sector_num, int nb_sectors, 1377 QEMUIOVector *qiov) 1378 { 1379 return qed_co_request(bs, sector_num, qiov, nb_sectors, 0); 1380 } 1381 1382 static int coroutine_fn bdrv_qed_co_writev(BlockDriverState *bs, 1383 int64_t sector_num, int nb_sectors, 1384 QEMUIOVector *qiov, int flags) 1385 { 1386 assert(!flags); 1387 return qed_co_request(bs, sector_num, qiov, nb_sectors, QED_AIOCB_WRITE); 1388 } 1389 1390 static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs, 1391 int64_t offset, 1392 int bytes, 1393 BdrvRequestFlags flags) 1394 { 1395 BDRVQEDState *s = bs->opaque; 1396 1397 /* 1398 * Zero writes start without an I/O buffer. If a buffer becomes necessary 1399 * then it will be allocated during request processing. 1400 */ 1401 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes); 1402 1403 /* Fall back if the request is not aligned */ 1404 if (qed_offset_into_cluster(s, offset) || 1405 qed_offset_into_cluster(s, bytes)) { 1406 return -ENOTSUP; 1407 } 1408 1409 return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov, 1410 bytes >> BDRV_SECTOR_BITS, 1411 QED_AIOCB_WRITE | QED_AIOCB_ZERO); 1412 } 1413 1414 static int coroutine_fn bdrv_qed_co_truncate(BlockDriverState *bs, 1415 int64_t offset, 1416 bool exact, 1417 PreallocMode prealloc, 1418 BdrvRequestFlags flags, 1419 Error **errp) 1420 { 1421 BDRVQEDState *s = bs->opaque; 1422 uint64_t old_image_size; 1423 int ret; 1424 1425 if (prealloc != PREALLOC_MODE_OFF) { 1426 error_setg(errp, "Unsupported preallocation mode '%s'", 1427 PreallocMode_str(prealloc)); 1428 return -ENOTSUP; 1429 } 1430 1431 if (!qed_is_image_size_valid(offset, s->header.cluster_size, 1432 s->header.table_size)) { 1433 error_setg(errp, "Invalid image size specified"); 1434 return -EINVAL; 1435 } 1436 1437 if ((uint64_t)offset < s->header.image_size) { 1438 error_setg(errp, "Shrinking images is currently not supported"); 1439 return -ENOTSUP; 1440 } 1441 1442 old_image_size = s->header.image_size; 1443 s->header.image_size = offset; 1444 ret = qed_write_header_sync(s); 1445 if (ret < 0) { 1446 s->header.image_size = old_image_size; 1447 error_setg_errno(errp, -ret, "Failed to update the image size"); 1448 } 1449 return ret; 1450 } 1451 1452 static int64_t bdrv_qed_getlength(BlockDriverState *bs) 1453 { 1454 BDRVQEDState *s = bs->opaque; 1455 return s->header.image_size; 1456 } 1457 1458 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1459 { 1460 BDRVQEDState *s = bs->opaque; 1461 1462 memset(bdi, 0, sizeof(*bdi)); 1463 bdi->cluster_size = s->header.cluster_size; 1464 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK; 1465 return 0; 1466 } 1467 1468 static int bdrv_qed_change_backing_file(BlockDriverState *bs, 1469 const char *backing_file, 1470 const char *backing_fmt) 1471 { 1472 BDRVQEDState *s = bs->opaque; 1473 QEDHeader new_header, le_header; 1474 void *buffer; 1475 size_t buffer_len, backing_file_len; 1476 int ret; 1477 1478 /* Refuse to set backing filename if unknown compat feature bits are 1479 * active. If the image uses an unknown compat feature then we may not 1480 * know the layout of data following the header structure and cannot safely 1481 * add a new string. 1482 */ 1483 if (backing_file && (s->header.compat_features & 1484 ~QED_COMPAT_FEATURE_MASK)) { 1485 return -ENOTSUP; 1486 } 1487 1488 memcpy(&new_header, &s->header, sizeof(new_header)); 1489 1490 new_header.features &= ~(QED_F_BACKING_FILE | 1491 QED_F_BACKING_FORMAT_NO_PROBE); 1492 1493 /* Adjust feature flags */ 1494 if (backing_file) { 1495 new_header.features |= QED_F_BACKING_FILE; 1496 1497 if (qed_fmt_is_raw(backing_fmt)) { 1498 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 1499 } 1500 } 1501 1502 /* Calculate new header size */ 1503 backing_file_len = 0; 1504 1505 if (backing_file) { 1506 backing_file_len = strlen(backing_file); 1507 } 1508 1509 buffer_len = sizeof(new_header); 1510 new_header.backing_filename_offset = buffer_len; 1511 new_header.backing_filename_size = backing_file_len; 1512 buffer_len += backing_file_len; 1513 1514 /* Make sure we can rewrite header without failing */ 1515 if (buffer_len > new_header.header_size * new_header.cluster_size) { 1516 return -ENOSPC; 1517 } 1518 1519 /* Prepare new header */ 1520 buffer = g_malloc(buffer_len); 1521 1522 qed_header_cpu_to_le(&new_header, &le_header); 1523 memcpy(buffer, &le_header, sizeof(le_header)); 1524 buffer_len = sizeof(le_header); 1525 1526 if (backing_file) { 1527 memcpy(buffer + buffer_len, backing_file, backing_file_len); 1528 buffer_len += backing_file_len; 1529 } 1530 1531 /* Write new header */ 1532 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len); 1533 g_free(buffer); 1534 if (ret == 0) { 1535 memcpy(&s->header, &new_header, sizeof(new_header)); 1536 } 1537 return ret; 1538 } 1539 1540 static void coroutine_fn bdrv_qed_co_invalidate_cache(BlockDriverState *bs, 1541 Error **errp) 1542 { 1543 BDRVQEDState *s = bs->opaque; 1544 Error *local_err = NULL; 1545 int ret; 1546 1547 bdrv_qed_close(bs); 1548 1549 bdrv_qed_init_state(bs); 1550 qemu_co_mutex_lock(&s->table_lock); 1551 ret = bdrv_qed_do_open(bs, NULL, bs->open_flags, &local_err); 1552 qemu_co_mutex_unlock(&s->table_lock); 1553 if (local_err) { 1554 error_propagate_prepend(errp, local_err, 1555 "Could not reopen qed layer: "); 1556 return; 1557 } else if (ret < 0) { 1558 error_setg_errno(errp, -ret, "Could not reopen qed layer"); 1559 return; 1560 } 1561 } 1562 1563 static int coroutine_fn bdrv_qed_co_check(BlockDriverState *bs, 1564 BdrvCheckResult *result, 1565 BdrvCheckMode fix) 1566 { 1567 BDRVQEDState *s = bs->opaque; 1568 int ret; 1569 1570 qemu_co_mutex_lock(&s->table_lock); 1571 ret = qed_check(s, result, !!fix); 1572 qemu_co_mutex_unlock(&s->table_lock); 1573 1574 return ret; 1575 } 1576 1577 static QemuOptsList qed_create_opts = { 1578 .name = "qed-create-opts", 1579 .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head), 1580 .desc = { 1581 { 1582 .name = BLOCK_OPT_SIZE, 1583 .type = QEMU_OPT_SIZE, 1584 .help = "Virtual disk size" 1585 }, 1586 { 1587 .name = BLOCK_OPT_BACKING_FILE, 1588 .type = QEMU_OPT_STRING, 1589 .help = "File name of a base image" 1590 }, 1591 { 1592 .name = BLOCK_OPT_BACKING_FMT, 1593 .type = QEMU_OPT_STRING, 1594 .help = "Image format of the base image" 1595 }, 1596 { 1597 .name = BLOCK_OPT_CLUSTER_SIZE, 1598 .type = QEMU_OPT_SIZE, 1599 .help = "Cluster size (in bytes)", 1600 .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE) 1601 }, 1602 { 1603 .name = BLOCK_OPT_TABLE_SIZE, 1604 .type = QEMU_OPT_SIZE, 1605 .help = "L1/L2 table size (in clusters)" 1606 }, 1607 { /* end of list */ } 1608 } 1609 }; 1610 1611 static BlockDriver bdrv_qed = { 1612 .format_name = "qed", 1613 .instance_size = sizeof(BDRVQEDState), 1614 .create_opts = &qed_create_opts, 1615 .is_format = true, 1616 .supports_backing = true, 1617 1618 .bdrv_probe = bdrv_qed_probe, 1619 .bdrv_open = bdrv_qed_open, 1620 .bdrv_close = bdrv_qed_close, 1621 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare, 1622 .bdrv_child_perm = bdrv_default_perms, 1623 .bdrv_co_create = bdrv_qed_co_create, 1624 .bdrv_co_create_opts = bdrv_qed_co_create_opts, 1625 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1626 .bdrv_co_block_status = bdrv_qed_co_block_status, 1627 .bdrv_co_readv = bdrv_qed_co_readv, 1628 .bdrv_co_writev = bdrv_qed_co_writev, 1629 .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes, 1630 .bdrv_co_truncate = bdrv_qed_co_truncate, 1631 .bdrv_getlength = bdrv_qed_getlength, 1632 .bdrv_get_info = bdrv_qed_get_info, 1633 .bdrv_refresh_limits = bdrv_qed_refresh_limits, 1634 .bdrv_change_backing_file = bdrv_qed_change_backing_file, 1635 .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache, 1636 .bdrv_co_check = bdrv_qed_co_check, 1637 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context, 1638 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context, 1639 .bdrv_co_drain_begin = bdrv_qed_co_drain_begin, 1640 }; 1641 1642 static void bdrv_qed_init(void) 1643 { 1644 bdrv_register(&bdrv_qed); 1645 } 1646 1647 block_init(bdrv_qed_init); 1648