qed.c (49645B)
1 /* 2 * QEMU Enhanced Disk Format 3 * 4 * Copyright IBM, Corp. 2010 5 * 6 * Authors: 7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> 8 * Anthony Liguori <aliguori@us.ibm.com> 9 * 10 * This work is licensed under the terms of the GNU LGPL, version 2 or later. 11 * See the COPYING.LIB file in the top-level directory. 12 * 13 */ 14 15 #include "qemu/osdep.h" 16 #include "block/qdict.h" 17 #include "qapi/error.h" 18 #include "qemu/timer.h" 19 #include "qemu/bswap.h" 20 #include "qemu/main-loop.h" 21 #include "qemu/module.h" 22 #include "qemu/option.h" 23 #include "qemu/memalign.h" 24 #include "trace.h" 25 #include "qed.h" 26 #include "sysemu/block-backend.h" 27 #include "qapi/qmp/qdict.h" 28 #include "qapi/qobject-input-visitor.h" 29 #include "qapi/qapi-visit-block-core.h" 30 31 static QemuOptsList qed_create_opts; 32 33 static int bdrv_qed_probe(const uint8_t *buf, int buf_size, 34 const char *filename) 35 { 36 const QEDHeader *header = (const QEDHeader *)buf; 37 38 if (buf_size < sizeof(*header)) { 39 return 0; 40 } 41 if (le32_to_cpu(header->magic) != QED_MAGIC) { 42 return 0; 43 } 44 return 100; 45 } 46 47 /** 48 * Check whether an image format is raw 49 * 50 * @fmt: Backing file format, may be NULL 51 */ 52 static bool qed_fmt_is_raw(const char *fmt) 53 { 54 return fmt && strcmp(fmt, "raw") == 0; 55 } 56 57 static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu) 58 { 59 cpu->magic = le32_to_cpu(le->magic); 60 cpu->cluster_size = le32_to_cpu(le->cluster_size); 61 cpu->table_size = le32_to_cpu(le->table_size); 62 cpu->header_size = le32_to_cpu(le->header_size); 63 cpu->features = le64_to_cpu(le->features); 64 cpu->compat_features = le64_to_cpu(le->compat_features); 65 cpu->autoclear_features = le64_to_cpu(le->autoclear_features); 66 cpu->l1_table_offset = le64_to_cpu(le->l1_table_offset); 67 cpu->image_size = le64_to_cpu(le->image_size); 68 cpu->backing_filename_offset = le32_to_cpu(le->backing_filename_offset); 69 cpu->backing_filename_size = le32_to_cpu(le->backing_filename_size); 70 } 71 72 static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le) 73 { 74 le->magic = cpu_to_le32(cpu->magic); 75 le->cluster_size = cpu_to_le32(cpu->cluster_size); 76 le->table_size = cpu_to_le32(cpu->table_size); 77 le->header_size = cpu_to_le32(cpu->header_size); 78 le->features = cpu_to_le64(cpu->features); 79 le->compat_features = cpu_to_le64(cpu->compat_features); 80 le->autoclear_features = cpu_to_le64(cpu->autoclear_features); 81 le->l1_table_offset = cpu_to_le64(cpu->l1_table_offset); 82 le->image_size = cpu_to_le64(cpu->image_size); 83 le->backing_filename_offset = cpu_to_le32(cpu->backing_filename_offset); 84 le->backing_filename_size = cpu_to_le32(cpu->backing_filename_size); 85 } 86 87 int qed_write_header_sync(BDRVQEDState *s) 88 { 89 QEDHeader le; 90 91 qed_header_cpu_to_le(&s->header, &le); 92 return bdrv_pwrite(s->bs->file, 0, sizeof(le), &le, 0); 93 } 94 95 /** 96 * Update header in-place (does not rewrite backing filename or other strings) 97 * 98 * This function only updates known header fields in-place and does not affect 99 * extra data after the QED header. 100 * 101 * No new allocating reqs can start while this function runs. 102 */ 103 static int coroutine_fn qed_write_header(BDRVQEDState *s) 104 { 105 /* We must write full sectors for O_DIRECT but cannot necessarily generate 106 * the data following the header if an unrecognized compat feature is 107 * active. Therefore, first read the sectors containing the header, update 108 * them, and write back. 109 */ 110 111 int nsectors = DIV_ROUND_UP(sizeof(QEDHeader), BDRV_SECTOR_SIZE); 112 size_t len = nsectors * BDRV_SECTOR_SIZE; 113 uint8_t *buf; 114 int ret; 115 116 assert(s->allocating_acb || s->allocating_write_reqs_plugged); 117 118 buf = qemu_blockalign(s->bs, len); 119 120 ret = bdrv_co_pread(s->bs->file, 0, len, buf, 0); 121 if (ret < 0) { 122 goto out; 123 } 124 125 /* Update header */ 126 qed_header_cpu_to_le(&s->header, (QEDHeader *) buf); 127 128 ret = bdrv_co_pwrite(s->bs->file, 0, len, buf, 0); 129 if (ret < 0) { 130 goto out; 131 } 132 133 ret = 0; 134 out: 135 qemu_vfree(buf); 136 return ret; 137 } 138 139 static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size) 140 { 141 uint64_t table_entries; 142 uint64_t l2_size; 143 144 table_entries = (table_size * cluster_size) / sizeof(uint64_t); 145 l2_size = table_entries * cluster_size; 146 147 return l2_size * table_entries; 148 } 149 150 static bool qed_is_cluster_size_valid(uint32_t cluster_size) 151 { 152 if (cluster_size < QED_MIN_CLUSTER_SIZE || 153 cluster_size > QED_MAX_CLUSTER_SIZE) { 154 return false; 155 } 156 if (cluster_size & (cluster_size - 1)) { 157 return false; /* not power of 2 */ 158 } 159 return true; 160 } 161 162 static bool qed_is_table_size_valid(uint32_t table_size) 163 { 164 if (table_size < QED_MIN_TABLE_SIZE || 165 table_size > QED_MAX_TABLE_SIZE) { 166 return false; 167 } 168 if (table_size & (table_size - 1)) { 169 return false; /* not power of 2 */ 170 } 171 return true; 172 } 173 174 static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size, 175 uint32_t table_size) 176 { 177 if (image_size % BDRV_SECTOR_SIZE != 0) { 178 return false; /* not multiple of sector size */ 179 } 180 if (image_size > qed_max_image_size(cluster_size, table_size)) { 181 return false; /* image is too large */ 182 } 183 return true; 184 } 185 186 /** 187 * Read a string of known length from the image file 188 * 189 * @file: Image file 190 * @offset: File offset to start of string, in bytes 191 * @n: String length in bytes 192 * @buf: Destination buffer 193 * @buflen: Destination buffer length in bytes 194 * @ret: 0 on success, -errno on failure 195 * 196 * The string is NUL-terminated. 197 */ 198 static int qed_read_string(BdrvChild *file, uint64_t offset, size_t n, 199 char *buf, size_t buflen) 200 { 201 int ret; 202 if (n >= buflen) { 203 return -EINVAL; 204 } 205 ret = bdrv_pread(file, offset, n, buf, 0); 206 if (ret < 0) { 207 return ret; 208 } 209 buf[n] = '\0'; 210 return 0; 211 } 212 213 /** 214 * Allocate new clusters 215 * 216 * @s: QED state 217 * @n: Number of contiguous clusters to allocate 218 * @ret: Offset of first allocated cluster 219 * 220 * This function only produces the offset where the new clusters should be 221 * written. It updates BDRVQEDState but does not make any changes to the image 222 * file. 223 * 224 * Called with table_lock held. 225 */ 226 static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n) 227 { 228 uint64_t offset = s->file_size; 229 s->file_size += n * s->header.cluster_size; 230 return offset; 231 } 232 233 QEDTable *qed_alloc_table(BDRVQEDState *s) 234 { 235 /* Honor O_DIRECT memory alignment requirements */ 236 return qemu_blockalign(s->bs, 237 s->header.cluster_size * s->header.table_size); 238 } 239 240 /** 241 * Allocate a new zeroed L2 table 242 * 243 * Called with table_lock held. 244 */ 245 static CachedL2Table *qed_new_l2_table(BDRVQEDState *s) 246 { 247 CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache); 248 249 l2_table->table = qed_alloc_table(s); 250 l2_table->offset = qed_alloc_clusters(s, s->header.table_size); 251 252 memset(l2_table->table->offsets, 0, 253 s->header.cluster_size * s->header.table_size); 254 return l2_table; 255 } 256 257 static bool coroutine_fn qed_plug_allocating_write_reqs(BDRVQEDState *s) 258 { 259 qemu_co_mutex_lock(&s->table_lock); 260 261 /* No reentrancy is allowed. */ 262 assert(!s->allocating_write_reqs_plugged); 263 if (s->allocating_acb != NULL) { 264 /* Another allocating write came concurrently. This cannot happen 265 * from bdrv_qed_co_drain_begin, but it can happen when the timer runs. 266 */ 267 qemu_co_mutex_unlock(&s->table_lock); 268 return false; 269 } 270 271 s->allocating_write_reqs_plugged = true; 272 qemu_co_mutex_unlock(&s->table_lock); 273 return true; 274 } 275 276 static void coroutine_fn qed_unplug_allocating_write_reqs(BDRVQEDState *s) 277 { 278 qemu_co_mutex_lock(&s->table_lock); 279 assert(s->allocating_write_reqs_plugged); 280 s->allocating_write_reqs_plugged = false; 281 qemu_co_queue_next(&s->allocating_write_reqs); 282 qemu_co_mutex_unlock(&s->table_lock); 283 } 284 285 static void coroutine_fn qed_need_check_timer_entry(void *opaque) 286 { 287 BDRVQEDState *s = opaque; 288 int ret; 289 290 trace_qed_need_check_timer_cb(s); 291 292 if (!qed_plug_allocating_write_reqs(s)) { 293 return; 294 } 295 296 /* Ensure writes are on disk before clearing flag */ 297 ret = bdrv_co_flush(s->bs->file->bs); 298 if (ret < 0) { 299 qed_unplug_allocating_write_reqs(s); 300 return; 301 } 302 303 s->header.features &= ~QED_F_NEED_CHECK; 304 ret = qed_write_header(s); 305 (void) ret; 306 307 qed_unplug_allocating_write_reqs(s); 308 309 ret = bdrv_co_flush(s->bs); 310 (void) ret; 311 } 312 313 static void qed_need_check_timer_cb(void *opaque) 314 { 315 Coroutine *co = qemu_coroutine_create(qed_need_check_timer_entry, opaque); 316 qemu_coroutine_enter(co); 317 } 318 319 static void qed_start_need_check_timer(BDRVQEDState *s) 320 { 321 trace_qed_start_need_check_timer(s); 322 323 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for 324 * migration. 325 */ 326 timer_mod(s->need_check_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + 327 NANOSECONDS_PER_SECOND * QED_NEED_CHECK_TIMEOUT); 328 } 329 330 /* It's okay to call this multiple times or when no timer is started */ 331 static void qed_cancel_need_check_timer(BDRVQEDState *s) 332 { 333 trace_qed_cancel_need_check_timer(s); 334 timer_del(s->need_check_timer); 335 } 336 337 static void bdrv_qed_detach_aio_context(BlockDriverState *bs) 338 { 339 BDRVQEDState *s = bs->opaque; 340 341 qed_cancel_need_check_timer(s); 342 timer_free(s->need_check_timer); 343 } 344 345 static void bdrv_qed_attach_aio_context(BlockDriverState *bs, 346 AioContext *new_context) 347 { 348 BDRVQEDState *s = bs->opaque; 349 350 s->need_check_timer = aio_timer_new(new_context, 351 QEMU_CLOCK_VIRTUAL, SCALE_NS, 352 qed_need_check_timer_cb, s); 353 if (s->header.features & QED_F_NEED_CHECK) { 354 qed_start_need_check_timer(s); 355 } 356 } 357 358 static void coroutine_fn bdrv_qed_co_drain_begin(BlockDriverState *bs) 359 { 360 BDRVQEDState *s = bs->opaque; 361 362 /* Fire the timer immediately in order to start doing I/O as soon as the 363 * header is flushed. 364 */ 365 if (s->need_check_timer && timer_pending(s->need_check_timer)) { 366 qed_cancel_need_check_timer(s); 367 qed_need_check_timer_entry(s); 368 } 369 } 370 371 static void bdrv_qed_init_state(BlockDriverState *bs) 372 { 373 BDRVQEDState *s = bs->opaque; 374 375 memset(s, 0, sizeof(BDRVQEDState)); 376 s->bs = bs; 377 qemu_co_mutex_init(&s->table_lock); 378 qemu_co_queue_init(&s->allocating_write_reqs); 379 } 380 381 /* Called with table_lock held. */ 382 static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options, 383 int flags, Error **errp) 384 { 385 BDRVQEDState *s = bs->opaque; 386 QEDHeader le_header; 387 int64_t file_size; 388 int ret; 389 390 ret = bdrv_co_pread(bs->file, 0, sizeof(le_header), &le_header, 0); 391 if (ret < 0) { 392 error_setg(errp, "Failed to read QED header"); 393 return ret; 394 } 395 qed_header_le_to_cpu(&le_header, &s->header); 396 397 if (s->header.magic != QED_MAGIC) { 398 error_setg(errp, "Image not in QED format"); 399 return -EINVAL; 400 } 401 if (s->header.features & ~QED_FEATURE_MASK) { 402 /* image uses unsupported feature bits */ 403 error_setg(errp, "Unsupported QED features: %" PRIx64, 404 s->header.features & ~QED_FEATURE_MASK); 405 return -ENOTSUP; 406 } 407 if (!qed_is_cluster_size_valid(s->header.cluster_size)) { 408 error_setg(errp, "QED cluster size is invalid"); 409 return -EINVAL; 410 } 411 412 /* Round down file size to the last cluster */ 413 file_size = bdrv_getlength(bs->file->bs); 414 if (file_size < 0) { 415 error_setg(errp, "Failed to get file length"); 416 return file_size; 417 } 418 s->file_size = qed_start_of_cluster(s, file_size); 419 420 if (!qed_is_table_size_valid(s->header.table_size)) { 421 error_setg(errp, "QED table size is invalid"); 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 error_setg(errp, "QED image size is invalid"); 428 return -EINVAL; 429 } 430 if (!qed_check_table_offset(s, s->header.l1_table_offset)) { 431 error_setg(errp, "QED table offset is invalid"); 432 return -EINVAL; 433 } 434 435 s->table_nelems = (s->header.cluster_size * s->header.table_size) / 436 sizeof(uint64_t); 437 s->l2_shift = ctz32(s->header.cluster_size); 438 s->l2_mask = s->table_nelems - 1; 439 s->l1_shift = s->l2_shift + ctz32(s->table_nelems); 440 441 /* Header size calculation must not overflow uint32_t */ 442 if (s->header.header_size > UINT32_MAX / s->header.cluster_size) { 443 error_setg(errp, "QED header size is too large"); 444 return -EINVAL; 445 } 446 447 if ((s->header.features & QED_F_BACKING_FILE)) { 448 g_autofree char *backing_file_str = NULL; 449 450 if ((uint64_t)s->header.backing_filename_offset + 451 s->header.backing_filename_size > 452 s->header.cluster_size * s->header.header_size) { 453 error_setg(errp, "QED backing filename offset is invalid"); 454 return -EINVAL; 455 } 456 457 backing_file_str = g_malloc(sizeof(bs->backing_file)); 458 ret = qed_read_string(bs->file, s->header.backing_filename_offset, 459 s->header.backing_filename_size, 460 backing_file_str, sizeof(bs->backing_file)); 461 if (ret < 0) { 462 error_setg(errp, "Failed to read backing filename"); 463 return ret; 464 } 465 466 if (!g_str_equal(backing_file_str, bs->backing_file)) { 467 pstrcpy(bs->backing_file, sizeof(bs->backing_file), 468 backing_file_str); 469 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), 470 backing_file_str); 471 } 472 473 if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) { 474 pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw"); 475 } 476 } 477 478 /* Reset unknown autoclear feature bits. This is a backwards 479 * compatibility mechanism that allows images to be opened by older 480 * programs, which "knock out" unknown feature bits. When an image is 481 * opened by a newer program again it can detect that the autoclear 482 * feature is no longer valid. 483 */ 484 if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 && 485 !bdrv_is_read_only(bs->file->bs) && !(flags & BDRV_O_INACTIVE)) { 486 s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK; 487 488 ret = qed_write_header_sync(s); 489 if (ret) { 490 error_setg(errp, "Failed to update header"); 491 return ret; 492 } 493 494 /* From here on only known autoclear feature bits are valid */ 495 bdrv_co_flush(bs->file->bs); 496 } 497 498 s->l1_table = qed_alloc_table(s); 499 qed_init_l2_cache(&s->l2_cache); 500 501 ret = qed_read_l1_table_sync(s); 502 if (ret) { 503 error_setg(errp, "Failed to read L1 table"); 504 goto out; 505 } 506 507 /* If image was not closed cleanly, check consistency */ 508 if (!(flags & BDRV_O_CHECK) && (s->header.features & QED_F_NEED_CHECK)) { 509 /* Read-only images cannot be fixed. There is no risk of corruption 510 * since write operations are not possible. Therefore, allow 511 * potentially inconsistent images to be opened read-only. This can 512 * aid data recovery from an otherwise inconsistent image. 513 */ 514 if (!bdrv_is_read_only(bs->file->bs) && 515 !(flags & BDRV_O_INACTIVE)) { 516 BdrvCheckResult result = {0}; 517 518 ret = qed_check(s, &result, true); 519 if (ret) { 520 error_setg(errp, "Image corrupted"); 521 goto out; 522 } 523 } 524 } 525 526 bdrv_qed_attach_aio_context(bs, bdrv_get_aio_context(bs)); 527 528 out: 529 if (ret) { 530 qed_free_l2_cache(&s->l2_cache); 531 qemu_vfree(s->l1_table); 532 } 533 return ret; 534 } 535 536 typedef struct QEDOpenCo { 537 BlockDriverState *bs; 538 QDict *options; 539 int flags; 540 Error **errp; 541 int ret; 542 } QEDOpenCo; 543 544 static void coroutine_fn bdrv_qed_open_entry(void *opaque) 545 { 546 QEDOpenCo *qoc = opaque; 547 BDRVQEDState *s = qoc->bs->opaque; 548 549 qemu_co_mutex_lock(&s->table_lock); 550 qoc->ret = bdrv_qed_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp); 551 qemu_co_mutex_unlock(&s->table_lock); 552 } 553 554 static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags, 555 Error **errp) 556 { 557 QEDOpenCo qoc = { 558 .bs = bs, 559 .options = options, 560 .flags = flags, 561 .errp = errp, 562 .ret = -EINPROGRESS 563 }; 564 int ret; 565 566 ret = bdrv_open_file_child(NULL, options, "file", bs, errp); 567 if (ret < 0) { 568 return ret; 569 } 570 571 bdrv_qed_init_state(bs); 572 if (qemu_in_coroutine()) { 573 bdrv_qed_open_entry(&qoc); 574 } else { 575 assert(qemu_get_current_aio_context() == qemu_get_aio_context()); 576 qemu_coroutine_enter(qemu_coroutine_create(bdrv_qed_open_entry, &qoc)); 577 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); 578 } 579 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); 580 return qoc.ret; 581 } 582 583 static void bdrv_qed_refresh_limits(BlockDriverState *bs, Error **errp) 584 { 585 BDRVQEDState *s = bs->opaque; 586 587 bs->bl.pwrite_zeroes_alignment = s->header.cluster_size; 588 bs->bl.max_pwrite_zeroes = QEMU_ALIGN_DOWN(INT_MAX, s->header.cluster_size); 589 } 590 591 /* We have nothing to do for QED reopen, stubs just return 592 * success */ 593 static int bdrv_qed_reopen_prepare(BDRVReopenState *state, 594 BlockReopenQueue *queue, Error **errp) 595 { 596 return 0; 597 } 598 599 static void bdrv_qed_close(BlockDriverState *bs) 600 { 601 BDRVQEDState *s = bs->opaque; 602 603 bdrv_qed_detach_aio_context(bs); 604 605 /* Ensure writes reach stable storage */ 606 bdrv_flush(bs->file->bs); 607 608 /* Clean shutdown, no check required on next open */ 609 if (s->header.features & QED_F_NEED_CHECK) { 610 s->header.features &= ~QED_F_NEED_CHECK; 611 qed_write_header_sync(s); 612 } 613 614 qed_free_l2_cache(&s->l2_cache); 615 qemu_vfree(s->l1_table); 616 } 617 618 static int coroutine_fn bdrv_qed_co_create(BlockdevCreateOptions *opts, 619 Error **errp) 620 { 621 BlockdevCreateOptionsQed *qed_opts; 622 BlockBackend *blk = NULL; 623 BlockDriverState *bs = NULL; 624 625 QEDHeader header; 626 QEDHeader le_header; 627 uint8_t *l1_table = NULL; 628 size_t l1_size; 629 int ret = 0; 630 631 assert(opts->driver == BLOCKDEV_DRIVER_QED); 632 qed_opts = &opts->u.qed; 633 634 /* Validate options and set default values */ 635 if (!qed_opts->has_cluster_size) { 636 qed_opts->cluster_size = QED_DEFAULT_CLUSTER_SIZE; 637 } 638 if (!qed_opts->has_table_size) { 639 qed_opts->table_size = QED_DEFAULT_TABLE_SIZE; 640 } 641 642 if (!qed_is_cluster_size_valid(qed_opts->cluster_size)) { 643 error_setg(errp, "QED cluster size must be within range [%u, %u] " 644 "and power of 2", 645 QED_MIN_CLUSTER_SIZE, QED_MAX_CLUSTER_SIZE); 646 return -EINVAL; 647 } 648 if (!qed_is_table_size_valid(qed_opts->table_size)) { 649 error_setg(errp, "QED table size must be within range [%u, %u] " 650 "and power of 2", 651 QED_MIN_TABLE_SIZE, QED_MAX_TABLE_SIZE); 652 return -EINVAL; 653 } 654 if (!qed_is_image_size_valid(qed_opts->size, qed_opts->cluster_size, 655 qed_opts->table_size)) 656 { 657 error_setg(errp, "QED image size must be a non-zero multiple of " 658 "cluster size and less than %" PRIu64 " bytes", 659 qed_max_image_size(qed_opts->cluster_size, 660 qed_opts->table_size)); 661 return -EINVAL; 662 } 663 664 /* Create BlockBackend to write to the image */ 665 bs = bdrv_open_blockdev_ref(qed_opts->file, errp); 666 if (bs == NULL) { 667 return -EIO; 668 } 669 670 blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL, 671 errp); 672 if (!blk) { 673 ret = -EPERM; 674 goto out; 675 } 676 blk_set_allow_write_beyond_eof(blk, true); 677 678 /* Prepare image format */ 679 header = (QEDHeader) { 680 .magic = QED_MAGIC, 681 .cluster_size = qed_opts->cluster_size, 682 .table_size = qed_opts->table_size, 683 .header_size = 1, 684 .features = 0, 685 .compat_features = 0, 686 .l1_table_offset = qed_opts->cluster_size, 687 .image_size = qed_opts->size, 688 }; 689 690 l1_size = header.cluster_size * header.table_size; 691 692 /* 693 * The QED format associates file length with allocation status, 694 * so a new file (which is empty) must have a length of 0. 695 */ 696 ret = blk_co_truncate(blk, 0, true, PREALLOC_MODE_OFF, 0, errp); 697 if (ret < 0) { 698 goto out; 699 } 700 701 if (qed_opts->has_backing_file) { 702 header.features |= QED_F_BACKING_FILE; 703 header.backing_filename_offset = sizeof(le_header); 704 header.backing_filename_size = strlen(qed_opts->backing_file); 705 706 if (qed_opts->has_backing_fmt) { 707 const char *backing_fmt = BlockdevDriver_str(qed_opts->backing_fmt); 708 if (qed_fmt_is_raw(backing_fmt)) { 709 header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 710 } 711 } 712 } 713 714 qed_header_cpu_to_le(&header, &le_header); 715 ret = blk_co_pwrite(blk, 0, sizeof(le_header), &le_header, 0); 716 if (ret < 0) { 717 goto out; 718 } 719 ret = blk_co_pwrite(blk, sizeof(le_header), header.backing_filename_size, 720 qed_opts->backing_file, 0); 721 if (ret < 0) { 722 goto out; 723 } 724 725 l1_table = g_malloc0(l1_size); 726 ret = blk_co_pwrite(blk, header.l1_table_offset, l1_size, l1_table, 0); 727 if (ret < 0) { 728 goto out; 729 } 730 731 ret = 0; /* success */ 732 out: 733 g_free(l1_table); 734 blk_unref(blk); 735 bdrv_unref(bs); 736 return ret; 737 } 738 739 static int coroutine_fn bdrv_qed_co_create_opts(BlockDriver *drv, 740 const char *filename, 741 QemuOpts *opts, 742 Error **errp) 743 { 744 BlockdevCreateOptions *create_options = NULL; 745 QDict *qdict; 746 Visitor *v; 747 BlockDriverState *bs = NULL; 748 int ret; 749 750 static const QDictRenames opt_renames[] = { 751 { BLOCK_OPT_BACKING_FILE, "backing-file" }, 752 { BLOCK_OPT_BACKING_FMT, "backing-fmt" }, 753 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" }, 754 { BLOCK_OPT_TABLE_SIZE, "table-size" }, 755 { NULL, NULL }, 756 }; 757 758 /* Parse options and convert legacy syntax */ 759 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qed_create_opts, true); 760 761 if (!qdict_rename_keys(qdict, opt_renames, errp)) { 762 ret = -EINVAL; 763 goto fail; 764 } 765 766 /* Create and open the file (protocol layer) */ 767 ret = bdrv_create_file(filename, opts, errp); 768 if (ret < 0) { 769 goto fail; 770 } 771 772 bs = bdrv_open(filename, NULL, NULL, 773 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); 774 if (bs == NULL) { 775 ret = -EIO; 776 goto fail; 777 } 778 779 /* Now get the QAPI type BlockdevCreateOptions */ 780 qdict_put_str(qdict, "driver", "qed"); 781 qdict_put_str(qdict, "file", bs->node_name); 782 783 v = qobject_input_visitor_new_flat_confused(qdict, errp); 784 if (!v) { 785 ret = -EINVAL; 786 goto fail; 787 } 788 789 visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp); 790 visit_free(v); 791 if (!create_options) { 792 ret = -EINVAL; 793 goto fail; 794 } 795 796 /* Silently round up size */ 797 assert(create_options->driver == BLOCKDEV_DRIVER_QED); 798 create_options->u.qed.size = 799 ROUND_UP(create_options->u.qed.size, BDRV_SECTOR_SIZE); 800 801 /* Create the qed image (format layer) */ 802 ret = bdrv_qed_co_create(create_options, errp); 803 804 fail: 805 qobject_unref(qdict); 806 bdrv_unref(bs); 807 qapi_free_BlockdevCreateOptions(create_options); 808 return ret; 809 } 810 811 static int coroutine_fn bdrv_qed_co_block_status(BlockDriverState *bs, 812 bool want_zero, 813 int64_t pos, int64_t bytes, 814 int64_t *pnum, int64_t *map, 815 BlockDriverState **file) 816 { 817 BDRVQEDState *s = bs->opaque; 818 size_t len = MIN(bytes, SIZE_MAX); 819 int status; 820 QEDRequest request = { .l2_table = NULL }; 821 uint64_t offset; 822 int ret; 823 824 qemu_co_mutex_lock(&s->table_lock); 825 ret = qed_find_cluster(s, &request, pos, &len, &offset); 826 827 *pnum = len; 828 switch (ret) { 829 case QED_CLUSTER_FOUND: 830 *map = offset | qed_offset_into_cluster(s, pos); 831 status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID; 832 *file = bs->file->bs; 833 break; 834 case QED_CLUSTER_ZERO: 835 status = BDRV_BLOCK_ZERO; 836 break; 837 case QED_CLUSTER_L2: 838 case QED_CLUSTER_L1: 839 status = 0; 840 break; 841 default: 842 assert(ret < 0); 843 status = ret; 844 break; 845 } 846 847 qed_unref_l2_cache_entry(request.l2_table); 848 qemu_co_mutex_unlock(&s->table_lock); 849 850 return status; 851 } 852 853 static BDRVQEDState *acb_to_s(QEDAIOCB *acb) 854 { 855 return acb->bs->opaque; 856 } 857 858 /** 859 * Read from the backing file or zero-fill if no backing file 860 * 861 * @s: QED state 862 * @pos: Byte position in device 863 * @qiov: Destination I/O vector 864 * 865 * This function reads qiov->size bytes starting at pos from the backing file. 866 * If there is no backing file then zeroes are read. 867 */ 868 static int coroutine_fn qed_read_backing_file(BDRVQEDState *s, uint64_t pos, 869 QEMUIOVector *qiov) 870 { 871 if (s->bs->backing) { 872 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO); 873 return bdrv_co_preadv(s->bs->backing, pos, qiov->size, qiov, 0); 874 } 875 qemu_iovec_memset(qiov, 0, 0, qiov->size); 876 return 0; 877 } 878 879 /** 880 * Copy data from backing file into the image 881 * 882 * @s: QED state 883 * @pos: Byte position in device 884 * @len: Number of bytes 885 * @offset: Byte offset in image file 886 */ 887 static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s, 888 uint64_t pos, uint64_t len, 889 uint64_t offset) 890 { 891 QEMUIOVector qiov; 892 int ret; 893 894 /* Skip copy entirely if there is no work to do */ 895 if (len == 0) { 896 return 0; 897 } 898 899 qemu_iovec_init_buf(&qiov, qemu_blockalign(s->bs, len), len); 900 901 ret = qed_read_backing_file(s, pos, &qiov); 902 903 if (ret) { 904 goto out; 905 } 906 907 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE); 908 ret = bdrv_co_pwritev(s->bs->file, offset, qiov.size, &qiov, 0); 909 if (ret < 0) { 910 goto out; 911 } 912 ret = 0; 913 out: 914 qemu_vfree(qemu_iovec_buf(&qiov)); 915 return ret; 916 } 917 918 /** 919 * Link one or more contiguous clusters into a table 920 * 921 * @s: QED state 922 * @table: L2 table 923 * @index: First cluster index 924 * @n: Number of contiguous clusters 925 * @cluster: First cluster offset 926 * 927 * The cluster offset may be an allocated byte offset in the image file, the 928 * zero cluster marker, or the unallocated cluster marker. 929 * 930 * Called with table_lock held. 931 */ 932 static void coroutine_fn qed_update_l2_table(BDRVQEDState *s, QEDTable *table, 933 int index, unsigned int n, 934 uint64_t cluster) 935 { 936 int i; 937 for (i = index; i < index + n; i++) { 938 table->offsets[i] = cluster; 939 if (!qed_offset_is_unalloc_cluster(cluster) && 940 !qed_offset_is_zero_cluster(cluster)) { 941 cluster += s->header.cluster_size; 942 } 943 } 944 } 945 946 /* Called with table_lock held. */ 947 static void coroutine_fn qed_aio_complete(QEDAIOCB *acb) 948 { 949 BDRVQEDState *s = acb_to_s(acb); 950 951 /* Free resources */ 952 qemu_iovec_destroy(&acb->cur_qiov); 953 qed_unref_l2_cache_entry(acb->request.l2_table); 954 955 /* Free the buffer we may have allocated for zero writes */ 956 if (acb->flags & QED_AIOCB_ZERO) { 957 qemu_vfree(acb->qiov->iov[0].iov_base); 958 acb->qiov->iov[0].iov_base = NULL; 959 } 960 961 /* Start next allocating write request waiting behind this one. Note that 962 * requests enqueue themselves when they first hit an unallocated cluster 963 * but they wait until the entire request is finished before waking up the 964 * next request in the queue. This ensures that we don't cycle through 965 * requests multiple times but rather finish one at a time completely. 966 */ 967 if (acb == s->allocating_acb) { 968 s->allocating_acb = NULL; 969 if (!qemu_co_queue_empty(&s->allocating_write_reqs)) { 970 qemu_co_queue_next(&s->allocating_write_reqs); 971 } else if (s->header.features & QED_F_NEED_CHECK) { 972 qed_start_need_check_timer(s); 973 } 974 } 975 } 976 977 /** 978 * Update L1 table with new L2 table offset and write it out 979 * 980 * Called with table_lock held. 981 */ 982 static int coroutine_fn qed_aio_write_l1_update(QEDAIOCB *acb) 983 { 984 BDRVQEDState *s = acb_to_s(acb); 985 CachedL2Table *l2_table = acb->request.l2_table; 986 uint64_t l2_offset = l2_table->offset; 987 int index, ret; 988 989 index = qed_l1_index(s, acb->cur_pos); 990 s->l1_table->offsets[index] = l2_table->offset; 991 992 ret = qed_write_l1_table(s, index, 1); 993 994 /* Commit the current L2 table to the cache */ 995 qed_commit_l2_cache_entry(&s->l2_cache, l2_table); 996 997 /* This is guaranteed to succeed because we just committed the entry to the 998 * cache. 999 */ 1000 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset); 1001 assert(acb->request.l2_table != NULL); 1002 1003 return ret; 1004 } 1005 1006 1007 /** 1008 * Update L2 table with new cluster offsets and write them out 1009 * 1010 * Called with table_lock held. 1011 */ 1012 static int coroutine_fn qed_aio_write_l2_update(QEDAIOCB *acb, uint64_t offset) 1013 { 1014 BDRVQEDState *s = acb_to_s(acb); 1015 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1; 1016 int index, ret; 1017 1018 if (need_alloc) { 1019 qed_unref_l2_cache_entry(acb->request.l2_table); 1020 acb->request.l2_table = qed_new_l2_table(s); 1021 } 1022 1023 index = qed_l2_index(s, acb->cur_pos); 1024 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters, 1025 offset); 1026 1027 if (need_alloc) { 1028 /* Write out the whole new L2 table */ 1029 ret = qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true); 1030 if (ret) { 1031 return ret; 1032 } 1033 return qed_aio_write_l1_update(acb); 1034 } else { 1035 /* Write out only the updated part of the L2 table */ 1036 ret = qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters, 1037 false); 1038 if (ret) { 1039 return ret; 1040 } 1041 } 1042 return 0; 1043 } 1044 1045 /** 1046 * Write data to the image file 1047 * 1048 * Called with table_lock *not* held. 1049 */ 1050 static int coroutine_fn qed_aio_write_main(QEDAIOCB *acb) 1051 { 1052 BDRVQEDState *s = acb_to_s(acb); 1053 uint64_t offset = acb->cur_cluster + 1054 qed_offset_into_cluster(s, acb->cur_pos); 1055 1056 trace_qed_aio_write_main(s, acb, 0, offset, acb->cur_qiov.size); 1057 1058 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO); 1059 return bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size, 1060 &acb->cur_qiov, 0); 1061 } 1062 1063 /** 1064 * Populate untouched regions of new data cluster 1065 * 1066 * Called with table_lock held. 1067 */ 1068 static int coroutine_fn qed_aio_write_cow(QEDAIOCB *acb) 1069 { 1070 BDRVQEDState *s = acb_to_s(acb); 1071 uint64_t start, len, offset; 1072 int ret; 1073 1074 qemu_co_mutex_unlock(&s->table_lock); 1075 1076 /* Populate front untouched region of new data cluster */ 1077 start = qed_start_of_cluster(s, acb->cur_pos); 1078 len = qed_offset_into_cluster(s, acb->cur_pos); 1079 1080 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster); 1081 ret = qed_copy_from_backing_file(s, start, len, acb->cur_cluster); 1082 if (ret < 0) { 1083 goto out; 1084 } 1085 1086 /* Populate back untouched region of new data cluster */ 1087 start = acb->cur_pos + acb->cur_qiov.size; 1088 len = qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start; 1089 offset = acb->cur_cluster + 1090 qed_offset_into_cluster(s, acb->cur_pos) + 1091 acb->cur_qiov.size; 1092 1093 trace_qed_aio_write_postfill(s, acb, start, len, offset); 1094 ret = qed_copy_from_backing_file(s, start, len, offset); 1095 if (ret < 0) { 1096 goto out; 1097 } 1098 1099 ret = qed_aio_write_main(acb); 1100 if (ret < 0) { 1101 goto out; 1102 } 1103 1104 if (s->bs->backing) { 1105 /* 1106 * Flush new data clusters before updating the L2 table 1107 * 1108 * This flush is necessary when a backing file is in use. A crash 1109 * during an allocating write could result in empty clusters in the 1110 * image. If the write only touched a subregion of the cluster, 1111 * then backing image sectors have been lost in the untouched 1112 * region. The solution is to flush after writing a new data 1113 * cluster and before updating the L2 table. 1114 */ 1115 ret = bdrv_co_flush(s->bs->file->bs); 1116 } 1117 1118 out: 1119 qemu_co_mutex_lock(&s->table_lock); 1120 return ret; 1121 } 1122 1123 /** 1124 * Check if the QED_F_NEED_CHECK bit should be set during allocating write 1125 */ 1126 static bool qed_should_set_need_check(BDRVQEDState *s) 1127 { 1128 /* The flush before L2 update path ensures consistency */ 1129 if (s->bs->backing) { 1130 return false; 1131 } 1132 1133 return !(s->header.features & QED_F_NEED_CHECK); 1134 } 1135 1136 /** 1137 * Write new data cluster 1138 * 1139 * @acb: Write request 1140 * @len: Length in bytes 1141 * 1142 * This path is taken when writing to previously unallocated clusters. 1143 * 1144 * Called with table_lock held. 1145 */ 1146 static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 1147 { 1148 BDRVQEDState *s = acb_to_s(acb); 1149 int ret; 1150 1151 /* Cancel timer when the first allocating request comes in */ 1152 if (s->allocating_acb == NULL) { 1153 qed_cancel_need_check_timer(s); 1154 } 1155 1156 /* Freeze this request if another allocating write is in progress */ 1157 if (s->allocating_acb != acb || s->allocating_write_reqs_plugged) { 1158 if (s->allocating_acb != NULL) { 1159 qemu_co_queue_wait(&s->allocating_write_reqs, &s->table_lock); 1160 assert(s->allocating_acb == NULL); 1161 } 1162 s->allocating_acb = acb; 1163 return -EAGAIN; /* start over with looking up table entries */ 1164 } 1165 1166 acb->cur_nclusters = qed_bytes_to_clusters(s, 1167 qed_offset_into_cluster(s, acb->cur_pos) + len); 1168 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1169 1170 if (acb->flags & QED_AIOCB_ZERO) { 1171 /* Skip ahead if the clusters are already zero */ 1172 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) { 1173 return 0; 1174 } 1175 acb->cur_cluster = 1; 1176 } else { 1177 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters); 1178 } 1179 1180 if (qed_should_set_need_check(s)) { 1181 s->header.features |= QED_F_NEED_CHECK; 1182 ret = qed_write_header(s); 1183 if (ret < 0) { 1184 return ret; 1185 } 1186 } 1187 1188 if (!(acb->flags & QED_AIOCB_ZERO)) { 1189 ret = qed_aio_write_cow(acb); 1190 if (ret < 0) { 1191 return ret; 1192 } 1193 } 1194 1195 return qed_aio_write_l2_update(acb, acb->cur_cluster); 1196 } 1197 1198 /** 1199 * Write data cluster in place 1200 * 1201 * @acb: Write request 1202 * @offset: Cluster offset in bytes 1203 * @len: Length in bytes 1204 * 1205 * This path is taken when writing to already allocated clusters. 1206 * 1207 * Called with table_lock held. 1208 */ 1209 static int coroutine_fn qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset, 1210 size_t len) 1211 { 1212 BDRVQEDState *s = acb_to_s(acb); 1213 int r; 1214 1215 qemu_co_mutex_unlock(&s->table_lock); 1216 1217 /* Allocate buffer for zero writes */ 1218 if (acb->flags & QED_AIOCB_ZERO) { 1219 struct iovec *iov = acb->qiov->iov; 1220 1221 if (!iov->iov_base) { 1222 iov->iov_base = qemu_try_blockalign(acb->bs, iov->iov_len); 1223 if (iov->iov_base == NULL) { 1224 r = -ENOMEM; 1225 goto out; 1226 } 1227 memset(iov->iov_base, 0, iov->iov_len); 1228 } 1229 } 1230 1231 /* Calculate the I/O vector */ 1232 acb->cur_cluster = offset; 1233 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1234 1235 /* Do the actual write. */ 1236 r = qed_aio_write_main(acb); 1237 out: 1238 qemu_co_mutex_lock(&s->table_lock); 1239 return r; 1240 } 1241 1242 /** 1243 * Write data cluster 1244 * 1245 * @opaque: Write request 1246 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1 1247 * @offset: Cluster offset in bytes 1248 * @len: Length in bytes 1249 * 1250 * Called with table_lock held. 1251 */ 1252 static int coroutine_fn qed_aio_write_data(void *opaque, int ret, 1253 uint64_t offset, size_t len) 1254 { 1255 QEDAIOCB *acb = opaque; 1256 1257 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len); 1258 1259 acb->find_cluster_ret = ret; 1260 1261 switch (ret) { 1262 case QED_CLUSTER_FOUND: 1263 return qed_aio_write_inplace(acb, offset, len); 1264 1265 case QED_CLUSTER_L2: 1266 case QED_CLUSTER_L1: 1267 case QED_CLUSTER_ZERO: 1268 return qed_aio_write_alloc(acb, len); 1269 1270 default: 1271 g_assert_not_reached(); 1272 } 1273 } 1274 1275 /** 1276 * Read data cluster 1277 * 1278 * @opaque: Read 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_read_data(void *opaque, int ret, 1286 uint64_t offset, size_t len) 1287 { 1288 QEDAIOCB *acb = opaque; 1289 BDRVQEDState *s = acb_to_s(acb); 1290 BlockDriverState *bs = acb->bs; 1291 int r; 1292 1293 qemu_co_mutex_unlock(&s->table_lock); 1294 1295 /* Adjust offset into cluster */ 1296 offset += qed_offset_into_cluster(s, acb->cur_pos); 1297 1298 trace_qed_aio_read_data(s, acb, ret, offset, len); 1299 1300 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len); 1301 1302 /* Handle zero cluster and backing file reads, otherwise read 1303 * data cluster directly. 1304 */ 1305 if (ret == QED_CLUSTER_ZERO) { 1306 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size); 1307 r = 0; 1308 } else if (ret != QED_CLUSTER_FOUND) { 1309 r = qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov); 1310 } else { 1311 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); 1312 r = bdrv_co_preadv(bs->file, offset, acb->cur_qiov.size, 1313 &acb->cur_qiov, 0); 1314 } 1315 1316 qemu_co_mutex_lock(&s->table_lock); 1317 return r; 1318 } 1319 1320 /** 1321 * Begin next I/O or complete the request 1322 */ 1323 static int coroutine_fn qed_aio_next_io(QEDAIOCB *acb) 1324 { 1325 BDRVQEDState *s = acb_to_s(acb); 1326 uint64_t offset; 1327 size_t len; 1328 int ret; 1329 1330 qemu_co_mutex_lock(&s->table_lock); 1331 while (1) { 1332 trace_qed_aio_next_io(s, acb, 0, acb->cur_pos + acb->cur_qiov.size); 1333 1334 acb->qiov_offset += acb->cur_qiov.size; 1335 acb->cur_pos += acb->cur_qiov.size; 1336 qemu_iovec_reset(&acb->cur_qiov); 1337 1338 /* Complete request */ 1339 if (acb->cur_pos >= acb->end_pos) { 1340 ret = 0; 1341 break; 1342 } 1343 1344 /* Find next cluster and start I/O */ 1345 len = acb->end_pos - acb->cur_pos; 1346 ret = qed_find_cluster(s, &acb->request, acb->cur_pos, &len, &offset); 1347 if (ret < 0) { 1348 break; 1349 } 1350 1351 if (acb->flags & QED_AIOCB_WRITE) { 1352 ret = qed_aio_write_data(acb, ret, offset, len); 1353 } else { 1354 ret = qed_aio_read_data(acb, ret, offset, len); 1355 } 1356 1357 if (ret < 0 && ret != -EAGAIN) { 1358 break; 1359 } 1360 } 1361 1362 trace_qed_aio_complete(s, acb, ret); 1363 qed_aio_complete(acb); 1364 qemu_co_mutex_unlock(&s->table_lock); 1365 return ret; 1366 } 1367 1368 static int coroutine_fn qed_co_request(BlockDriverState *bs, int64_t sector_num, 1369 QEMUIOVector *qiov, int nb_sectors, 1370 int flags) 1371 { 1372 QEDAIOCB acb = { 1373 .bs = bs, 1374 .cur_pos = (uint64_t) sector_num * BDRV_SECTOR_SIZE, 1375 .end_pos = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE, 1376 .qiov = qiov, 1377 .flags = flags, 1378 }; 1379 qemu_iovec_init(&acb.cur_qiov, qiov->niov); 1380 1381 trace_qed_aio_setup(bs->opaque, &acb, sector_num, nb_sectors, NULL, flags); 1382 1383 /* Start request */ 1384 return qed_aio_next_io(&acb); 1385 } 1386 1387 static int coroutine_fn bdrv_qed_co_readv(BlockDriverState *bs, 1388 int64_t sector_num, int nb_sectors, 1389 QEMUIOVector *qiov) 1390 { 1391 return qed_co_request(bs, sector_num, qiov, nb_sectors, 0); 1392 } 1393 1394 static int coroutine_fn bdrv_qed_co_writev(BlockDriverState *bs, 1395 int64_t sector_num, int nb_sectors, 1396 QEMUIOVector *qiov, int flags) 1397 { 1398 return qed_co_request(bs, sector_num, qiov, nb_sectors, QED_AIOCB_WRITE); 1399 } 1400 1401 static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs, 1402 int64_t offset, 1403 int64_t bytes, 1404 BdrvRequestFlags flags) 1405 { 1406 BDRVQEDState *s = bs->opaque; 1407 1408 /* 1409 * Zero writes start without an I/O buffer. If a buffer becomes necessary 1410 * then it will be allocated during request processing. 1411 */ 1412 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes); 1413 1414 /* 1415 * QED is not prepared for 63bit write-zero requests, so rely on 1416 * max_pwrite_zeroes. 1417 */ 1418 assert(bytes <= INT_MAX); 1419 1420 /* Fall back if the request is not aligned */ 1421 if (qed_offset_into_cluster(s, offset) || 1422 qed_offset_into_cluster(s, bytes)) { 1423 return -ENOTSUP; 1424 } 1425 1426 return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov, 1427 bytes >> BDRV_SECTOR_BITS, 1428 QED_AIOCB_WRITE | QED_AIOCB_ZERO); 1429 } 1430 1431 static int coroutine_fn bdrv_qed_co_truncate(BlockDriverState *bs, 1432 int64_t offset, 1433 bool exact, 1434 PreallocMode prealloc, 1435 BdrvRequestFlags flags, 1436 Error **errp) 1437 { 1438 BDRVQEDState *s = bs->opaque; 1439 uint64_t old_image_size; 1440 int ret; 1441 1442 if (prealloc != PREALLOC_MODE_OFF) { 1443 error_setg(errp, "Unsupported preallocation mode '%s'", 1444 PreallocMode_str(prealloc)); 1445 return -ENOTSUP; 1446 } 1447 1448 if (!qed_is_image_size_valid(offset, s->header.cluster_size, 1449 s->header.table_size)) { 1450 error_setg(errp, "Invalid image size specified"); 1451 return -EINVAL; 1452 } 1453 1454 if ((uint64_t)offset < s->header.image_size) { 1455 error_setg(errp, "Shrinking images is currently not supported"); 1456 return -ENOTSUP; 1457 } 1458 1459 old_image_size = s->header.image_size; 1460 s->header.image_size = offset; 1461 ret = qed_write_header_sync(s); 1462 if (ret < 0) { 1463 s->header.image_size = old_image_size; 1464 error_setg_errno(errp, -ret, "Failed to update the image size"); 1465 } 1466 return ret; 1467 } 1468 1469 static int64_t bdrv_qed_getlength(BlockDriverState *bs) 1470 { 1471 BDRVQEDState *s = bs->opaque; 1472 return s->header.image_size; 1473 } 1474 1475 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) 1476 { 1477 BDRVQEDState *s = bs->opaque; 1478 1479 memset(bdi, 0, sizeof(*bdi)); 1480 bdi->cluster_size = s->header.cluster_size; 1481 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK; 1482 return 0; 1483 } 1484 1485 static int bdrv_qed_change_backing_file(BlockDriverState *bs, 1486 const char *backing_file, 1487 const char *backing_fmt) 1488 { 1489 BDRVQEDState *s = bs->opaque; 1490 QEDHeader new_header, le_header; 1491 void *buffer; 1492 size_t buffer_len, backing_file_len; 1493 int ret; 1494 1495 /* Refuse to set backing filename if unknown compat feature bits are 1496 * active. If the image uses an unknown compat feature then we may not 1497 * know the layout of data following the header structure and cannot safely 1498 * add a new string. 1499 */ 1500 if (backing_file && (s->header.compat_features & 1501 ~QED_COMPAT_FEATURE_MASK)) { 1502 return -ENOTSUP; 1503 } 1504 1505 memcpy(&new_header, &s->header, sizeof(new_header)); 1506 1507 new_header.features &= ~(QED_F_BACKING_FILE | 1508 QED_F_BACKING_FORMAT_NO_PROBE); 1509 1510 /* Adjust feature flags */ 1511 if (backing_file) { 1512 new_header.features |= QED_F_BACKING_FILE; 1513 1514 if (qed_fmt_is_raw(backing_fmt)) { 1515 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE; 1516 } 1517 } 1518 1519 /* Calculate new header size */ 1520 backing_file_len = 0; 1521 1522 if (backing_file) { 1523 backing_file_len = strlen(backing_file); 1524 } 1525 1526 buffer_len = sizeof(new_header); 1527 new_header.backing_filename_offset = buffer_len; 1528 new_header.backing_filename_size = backing_file_len; 1529 buffer_len += backing_file_len; 1530 1531 /* Make sure we can rewrite header without failing */ 1532 if (buffer_len > new_header.header_size * new_header.cluster_size) { 1533 return -ENOSPC; 1534 } 1535 1536 /* Prepare new header */ 1537 buffer = g_malloc(buffer_len); 1538 1539 qed_header_cpu_to_le(&new_header, &le_header); 1540 memcpy(buffer, &le_header, sizeof(le_header)); 1541 buffer_len = sizeof(le_header); 1542 1543 if (backing_file) { 1544 memcpy(buffer + buffer_len, backing_file, backing_file_len); 1545 buffer_len += backing_file_len; 1546 } 1547 1548 /* Write new header */ 1549 ret = bdrv_pwrite_sync(bs->file, 0, buffer_len, buffer, 0); 1550 g_free(buffer); 1551 if (ret == 0) { 1552 memcpy(&s->header, &new_header, sizeof(new_header)); 1553 } 1554 return ret; 1555 } 1556 1557 static void coroutine_fn bdrv_qed_co_invalidate_cache(BlockDriverState *bs, 1558 Error **errp) 1559 { 1560 BDRVQEDState *s = bs->opaque; 1561 int ret; 1562 1563 bdrv_qed_close(bs); 1564 1565 bdrv_qed_init_state(bs); 1566 qemu_co_mutex_lock(&s->table_lock); 1567 ret = bdrv_qed_do_open(bs, NULL, bs->open_flags, errp); 1568 qemu_co_mutex_unlock(&s->table_lock); 1569 if (ret < 0) { 1570 error_prepend(errp, "Could not reopen qed layer: "); 1571 } 1572 } 1573 1574 static int coroutine_fn bdrv_qed_co_check(BlockDriverState *bs, 1575 BdrvCheckResult *result, 1576 BdrvCheckMode fix) 1577 { 1578 BDRVQEDState *s = bs->opaque; 1579 int ret; 1580 1581 qemu_co_mutex_lock(&s->table_lock); 1582 ret = qed_check(s, result, !!fix); 1583 qemu_co_mutex_unlock(&s->table_lock); 1584 1585 return ret; 1586 } 1587 1588 static QemuOptsList qed_create_opts = { 1589 .name = "qed-create-opts", 1590 .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head), 1591 .desc = { 1592 { 1593 .name = BLOCK_OPT_SIZE, 1594 .type = QEMU_OPT_SIZE, 1595 .help = "Virtual disk size" 1596 }, 1597 { 1598 .name = BLOCK_OPT_BACKING_FILE, 1599 .type = QEMU_OPT_STRING, 1600 .help = "File name of a base image" 1601 }, 1602 { 1603 .name = BLOCK_OPT_BACKING_FMT, 1604 .type = QEMU_OPT_STRING, 1605 .help = "Image format of the base image" 1606 }, 1607 { 1608 .name = BLOCK_OPT_CLUSTER_SIZE, 1609 .type = QEMU_OPT_SIZE, 1610 .help = "Cluster size (in bytes)", 1611 .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE) 1612 }, 1613 { 1614 .name = BLOCK_OPT_TABLE_SIZE, 1615 .type = QEMU_OPT_SIZE, 1616 .help = "L1/L2 table size (in clusters)" 1617 }, 1618 { /* end of list */ } 1619 } 1620 }; 1621 1622 static BlockDriver bdrv_qed = { 1623 .format_name = "qed", 1624 .instance_size = sizeof(BDRVQEDState), 1625 .create_opts = &qed_create_opts, 1626 .is_format = true, 1627 .supports_backing = true, 1628 1629 .bdrv_probe = bdrv_qed_probe, 1630 .bdrv_open = bdrv_qed_open, 1631 .bdrv_close = bdrv_qed_close, 1632 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare, 1633 .bdrv_child_perm = bdrv_default_perms, 1634 .bdrv_co_create = bdrv_qed_co_create, 1635 .bdrv_co_create_opts = bdrv_qed_co_create_opts, 1636 .bdrv_has_zero_init = bdrv_has_zero_init_1, 1637 .bdrv_co_block_status = bdrv_qed_co_block_status, 1638 .bdrv_co_readv = bdrv_qed_co_readv, 1639 .bdrv_co_writev = bdrv_qed_co_writev, 1640 .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes, 1641 .bdrv_co_truncate = bdrv_qed_co_truncate, 1642 .bdrv_getlength = bdrv_qed_getlength, 1643 .bdrv_get_info = bdrv_qed_get_info, 1644 .bdrv_refresh_limits = bdrv_qed_refresh_limits, 1645 .bdrv_change_backing_file = bdrv_qed_change_backing_file, 1646 .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache, 1647 .bdrv_co_check = bdrv_qed_co_check, 1648 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context, 1649 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context, 1650 .bdrv_co_drain_begin = bdrv_qed_co_drain_begin, 1651 }; 1652 1653 static void bdrv_qed_init(void) 1654 { 1655 bdrv_register(&bdrv_qed); 1656 } 1657 1658 block_init(bdrv_qed_init);