multifd: Add multifd-zstd-level parameter
[qemu/kevin.git] / block / qed.c
blobd8c4e5fb1e856e629dcf50dc3566f4ede8c49ccc
1 /*
2 * QEMU Enhanced Disk Format
4 * Copyright IBM, Corp. 2010
6 * Authors:
7 * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
8 * Anthony Liguori <aliguori@us.ibm.com>
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.
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"
30 static QemuOptsList qed_create_opts;
32 static int bdrv_qed_probe(const uint8_t *buf, int buf_size,
33 const char *filename)
35 const QEDHeader *header = (const QEDHeader *)buf;
37 if (buf_size < sizeof(*header)) {
38 return 0;
40 if (le32_to_cpu(header->magic) != QED_MAGIC) {
41 return 0;
43 return 100;
46 /**
47 * Check whether an image format is raw
49 * @fmt: Backing file format, may be NULL
51 static bool qed_fmt_is_raw(const char *fmt)
53 return fmt && strcmp(fmt, "raw") == 0;
56 static void qed_header_le_to_cpu(const QEDHeader *le, QEDHeader *cpu)
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);
71 static void qed_header_cpu_to_le(const QEDHeader *cpu, QEDHeader *le)
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);
86 int qed_write_header_sync(BDRVQEDState *s)
88 QEDHeader le;
89 int ret;
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;
96 return 0;
99 /**
100 * Update header in-place (does not rewrite backing filename or other strings)
102 * This function only updates known header fields in-place and does not affect
103 * extra data after the QED header.
105 * No new allocating reqs can start while this function runs.
107 static int coroutine_fn qed_write_header(BDRVQEDState *s)
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.
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;
120 assert(s->allocating_acb || s->allocating_write_reqs_plugged);
122 buf = qemu_blockalign(s->bs, len);
124 ret = bdrv_co_pread(s->bs->file, 0, len, buf, 0);
125 if (ret < 0) {
126 goto out;
129 /* Update header */
130 qed_header_cpu_to_le(&s->header, (QEDHeader *) buf);
132 ret = bdrv_co_pwrite(s->bs->file, 0, len, buf, 0);
133 if (ret < 0) {
134 goto out;
137 ret = 0;
138 out:
139 qemu_vfree(buf);
140 return ret;
143 static uint64_t qed_max_image_size(uint32_t cluster_size, uint32_t table_size)
145 uint64_t table_entries;
146 uint64_t l2_size;
148 table_entries = (table_size * cluster_size) / sizeof(uint64_t);
149 l2_size = table_entries * cluster_size;
151 return l2_size * table_entries;
154 static bool qed_is_cluster_size_valid(uint32_t cluster_size)
156 if (cluster_size < QED_MIN_CLUSTER_SIZE ||
157 cluster_size > QED_MAX_CLUSTER_SIZE) {
158 return false;
160 if (cluster_size & (cluster_size - 1)) {
161 return false; /* not power of 2 */
163 return true;
166 static bool qed_is_table_size_valid(uint32_t table_size)
168 if (table_size < QED_MIN_TABLE_SIZE ||
169 table_size > QED_MAX_TABLE_SIZE) {
170 return false;
172 if (table_size & (table_size - 1)) {
173 return false; /* not power of 2 */
175 return true;
178 static bool qed_is_image_size_valid(uint64_t image_size, uint32_t cluster_size,
179 uint32_t table_size)
181 if (image_size % BDRV_SECTOR_SIZE != 0) {
182 return false; /* not multiple of sector size */
184 if (image_size > qed_max_image_size(cluster_size, table_size)) {
185 return false; /* image is too large */
187 return true;
191 * Read a string of known length from the image file
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
200 * The string is NUL-terminated.
202 static int qed_read_string(BdrvChild *file, uint64_t offset, size_t n,
203 char *buf, size_t buflen)
205 int ret;
206 if (n >= buflen) {
207 return -EINVAL;
209 ret = bdrv_pread(file, offset, buf, n);
210 if (ret < 0) {
211 return ret;
213 buf[n] = '\0';
214 return 0;
218 * Allocate new clusters
220 * @s: QED state
221 * @n: Number of contiguous clusters to allocate
222 * @ret: Offset of first allocated cluster
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.
228 * Called with table_lock held.
230 static uint64_t qed_alloc_clusters(BDRVQEDState *s, unsigned int n)
232 uint64_t offset = s->file_size;
233 s->file_size += n * s->header.cluster_size;
234 return offset;
237 QEDTable *qed_alloc_table(BDRVQEDState *s)
239 /* Honor O_DIRECT memory alignment requirements */
240 return qemu_blockalign(s->bs,
241 s->header.cluster_size * s->header.table_size);
245 * Allocate a new zeroed L2 table
247 * Called with table_lock held.
249 static CachedL2Table *qed_new_l2_table(BDRVQEDState *s)
251 CachedL2Table *l2_table = qed_alloc_l2_cache_entry(&s->l2_cache);
253 l2_table->table = qed_alloc_table(s);
254 l2_table->offset = qed_alloc_clusters(s, s->header.table_size);
256 memset(l2_table->table->offsets, 0,
257 s->header.cluster_size * s->header.table_size);
258 return l2_table;
261 static bool qed_plug_allocating_write_reqs(BDRVQEDState *s)
263 qemu_co_mutex_lock(&s->table_lock);
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.
271 qemu_co_mutex_unlock(&s->table_lock);
272 return false;
275 s->allocating_write_reqs_plugged = true;
276 qemu_co_mutex_unlock(&s->table_lock);
277 return true;
280 static void qed_unplug_allocating_write_reqs(BDRVQEDState *s)
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);
289 static void coroutine_fn qed_need_check_timer_entry(void *opaque)
291 BDRVQEDState *s = opaque;
292 int ret;
294 trace_qed_need_check_timer_cb(s);
296 if (!qed_plug_allocating_write_reqs(s)) {
297 return;
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;
307 s->header.features &= ~QED_F_NEED_CHECK;
308 ret = qed_write_header(s);
309 (void) ret;
311 qed_unplug_allocating_write_reqs(s);
313 ret = bdrv_co_flush(s->bs);
314 (void) ret;
317 static void qed_need_check_timer_cb(void *opaque)
319 Coroutine *co = qemu_coroutine_create(qed_need_check_timer_entry, opaque);
320 qemu_coroutine_enter(co);
323 static void qed_start_need_check_timer(BDRVQEDState *s)
325 trace_qed_start_need_check_timer(s);
327 /* Use QEMU_CLOCK_VIRTUAL so we don't alter the image file while suspended for
328 * migration.
330 timer_mod(s->need_check_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
331 NANOSECONDS_PER_SECOND * QED_NEED_CHECK_TIMEOUT);
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)
337 trace_qed_cancel_need_check_timer(s);
338 timer_del(s->need_check_timer);
341 static void bdrv_qed_detach_aio_context(BlockDriverState *bs)
343 BDRVQEDState *s = bs->opaque;
345 qed_cancel_need_check_timer(s);
346 timer_free(s->need_check_timer);
349 static void bdrv_qed_attach_aio_context(BlockDriverState *bs,
350 AioContext *new_context)
352 BDRVQEDState *s = bs->opaque;
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);
362 static void coroutine_fn bdrv_qed_co_drain_begin(BlockDriverState *bs)
364 BDRVQEDState *s = bs->opaque;
366 /* Fire the timer immediately in order to start doing I/O as soon as the
367 * header is flushed.
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);
375 static void bdrv_qed_init_state(BlockDriverState *bs)
377 BDRVQEDState *s = bs->opaque;
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);
385 /* Called with table_lock held. */
386 static int coroutine_fn bdrv_qed_do_open(BlockDriverState *bs, QDict *options,
387 int flags, Error **errp)
389 BDRVQEDState *s = bs->opaque;
390 QEDHeader le_header;
391 int64_t file_size;
392 int ret;
394 ret = bdrv_pread(bs->file, 0, &le_header, sizeof(le_header));
395 if (ret < 0) {
396 return ret;
398 qed_header_le_to_cpu(&le_header, &s->header);
400 if (s->header.magic != QED_MAGIC) {
401 error_setg(errp, "Image not in QED format");
402 return -EINVAL;
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;
410 if (!qed_is_cluster_size_valid(s->header.cluster_size)) {
411 return -EINVAL;
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;
419 s->file_size = qed_start_of_cluster(s, file_size);
421 if (!qed_is_table_size_valid(s->header.table_size)) {
422 return -EINVAL;
424 if (!qed_is_image_size_valid(s->header.image_size,
425 s->header.cluster_size,
426 s->header.table_size)) {
427 return -EINVAL;
429 if (!qed_check_table_offset(s, s->header.l1_table_offset)) {
430 return -EINVAL;
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);
439 /* Header size calculation must not overflow uint32_t */
440 if (s->header.header_size > UINT32_MAX / s->header.cluster_size) {
441 return -EINVAL;
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;
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;
458 pstrcpy(bs->backing_file, sizeof(bs->backing_file),
459 bs->auto_backing_file);
461 if (s->header.features & QED_F_BACKING_FORMAT_NO_PROBE) {
462 pstrcpy(bs->backing_format, sizeof(bs->backing_format), "raw");
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.
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;
476 ret = qed_write_header_sync(s);
477 if (ret) {
478 return ret;
481 /* From here on only known autoclear feature bits are valid */
482 bdrv_flush(bs->file->bs);
485 s->l1_table = qed_alloc_table(s);
486 qed_init_l2_cache(&s->l2_cache);
488 ret = qed_read_l1_table_sync(s);
489 if (ret) {
490 goto out;
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.
500 if (!bdrv_is_read_only(bs->file->bs) &&
501 !(flags & BDRV_O_INACTIVE)) {
502 BdrvCheckResult result = {0};
504 ret = qed_check(s, &result, true);
505 if (ret) {
506 goto out;
511 bdrv_qed_attach_aio_context(bs, bdrv_get_aio_context(bs));
513 out:
514 if (ret) {
515 qed_free_l2_cache(&s->l2_cache);
516 qemu_vfree(s->l1_table);
518 return ret;
521 typedef struct QEDOpenCo {
522 BlockDriverState *bs;
523 QDict *options;
524 int flags;
525 Error **errp;
526 int ret;
527 } QEDOpenCo;
529 static void coroutine_fn bdrv_qed_open_entry(void *opaque)
531 QEDOpenCo *qoc = opaque;
532 BDRVQEDState *s = qoc->bs->opaque;
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);
539 static int bdrv_qed_open(BlockDriverState *bs, QDict *options, int flags,
540 Error **errp)
542 QEDOpenCo qoc = {
543 .bs = bs,
544 .options = options,
545 .flags = flags,
546 .errp = errp,
547 .ret = -EINPROGRESS
550 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
551 false, errp);
552 if (!bs->file) {
553 return -EINVAL;
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);
564 BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS);
565 return qoc.ret;
568 static void bdrv_qed_refresh_limits(BlockDriverState *bs, Error **errp)
570 BDRVQEDState *s = bs->opaque;
572 bs->bl.pwrite_zeroes_alignment = s->header.cluster_size;
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)
580 return 0;
583 static void bdrv_qed_close(BlockDriverState *bs)
585 BDRVQEDState *s = bs->opaque;
587 bdrv_qed_detach_aio_context(bs);
589 /* Ensure writes reach stable storage */
590 bdrv_flush(bs->file->bs);
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);
598 qed_free_l2_cache(&s->l2_cache);
599 qemu_vfree(s->l1_table);
602 static int coroutine_fn bdrv_qed_co_create(BlockdevCreateOptions *opts,
603 Error **errp)
605 BlockdevCreateOptionsQed *qed_opts;
606 BlockBackend *blk = NULL;
607 BlockDriverState *bs = NULL;
609 QEDHeader header;
610 QEDHeader le_header;
611 uint8_t *l1_table = NULL;
612 size_t l1_size;
613 int ret = 0;
615 assert(opts->driver == BLOCKDEV_DRIVER_QED);
616 qed_opts = &opts->u.qed;
618 /* Validate options and set default values */
619 if (!qed_opts->has_cluster_size) {
620 qed_opts->cluster_size = QED_DEFAULT_CLUSTER_SIZE;
622 if (!qed_opts->has_table_size) {
623 qed_opts->table_size = QED_DEFAULT_TABLE_SIZE;
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;
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;
638 if (!qed_is_image_size_valid(qed_opts->size, qed_opts->cluster_size,
639 qed_opts->table_size))
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;
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;
654 blk = blk_new(bdrv_get_aio_context(bs),
655 BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL);
656 ret = blk_insert_bs(blk, bs, errp);
657 if (ret < 0) {
658 goto out;
660 blk_set_allow_write_beyond_eof(blk, true);
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,
674 l1_size = header.cluster_size * header.table_size;
677 * The QED format associates file length with allocation status,
678 * so a new file (which is empty) must have a length of 0.
680 ret = blk_truncate(blk, 0, true, PREALLOC_MODE_OFF, errp);
681 if (ret < 0) {
682 goto out;
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);
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;
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;
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;
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;
715 ret = 0; /* success */
716 out:
717 g_free(l1_table);
718 blk_unref(blk);
719 bdrv_unref(bs);
720 return ret;
723 static int coroutine_fn bdrv_qed_co_create_opts(const char *filename,
724 QemuOpts *opts,
725 Error **errp)
727 BlockdevCreateOptions *create_options = NULL;
728 QDict *qdict;
729 Visitor *v;
730 BlockDriverState *bs = NULL;
731 Error *local_err = NULL;
732 int ret;
734 static const QDictRenames opt_renames[] = {
735 { BLOCK_OPT_BACKING_FILE, "backing-file" },
736 { BLOCK_OPT_BACKING_FMT, "backing-fmt" },
737 { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" },
738 { BLOCK_OPT_TABLE_SIZE, "table-size" },
739 { NULL, NULL },
742 /* Parse options and convert legacy syntax */
743 qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qed_create_opts, true);
745 if (!qdict_rename_keys(qdict, opt_renames, errp)) {
746 ret = -EINVAL;
747 goto fail;
750 /* Create and open the file (protocol layer) */
751 ret = bdrv_create_file(filename, opts, &local_err);
752 if (ret < 0) {
753 error_propagate(errp, local_err);
754 goto fail;
757 bs = bdrv_open(filename, NULL, NULL,
758 BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
759 if (bs == NULL) {
760 ret = -EIO;
761 goto fail;
764 /* Now get the QAPI type BlockdevCreateOptions */
765 qdict_put_str(qdict, "driver", "qed");
766 qdict_put_str(qdict, "file", bs->node_name);
768 v = qobject_input_visitor_new_flat_confused(qdict, errp);
769 if (!v) {
770 ret = -EINVAL;
771 goto fail;
774 visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err);
775 visit_free(v);
777 if (local_err) {
778 error_propagate(errp, local_err);
779 ret = -EINVAL;
780 goto fail;
783 /* Silently round up size */
784 assert(create_options->driver == BLOCKDEV_DRIVER_QED);
785 create_options->u.qed.size =
786 ROUND_UP(create_options->u.qed.size, BDRV_SECTOR_SIZE);
788 /* Create the qed image (format layer) */
789 ret = bdrv_qed_co_create(create_options, errp);
791 fail:
792 qobject_unref(qdict);
793 bdrv_unref(bs);
794 qapi_free_BlockdevCreateOptions(create_options);
795 return ret;
798 static int coroutine_fn bdrv_qed_co_block_status(BlockDriverState *bs,
799 bool want_zero,
800 int64_t pos, int64_t bytes,
801 int64_t *pnum, int64_t *map,
802 BlockDriverState **file)
804 BDRVQEDState *s = bs->opaque;
805 size_t len = MIN(bytes, SIZE_MAX);
806 int status;
807 QEDRequest request = { .l2_table = NULL };
808 uint64_t offset;
809 int ret;
811 qemu_co_mutex_lock(&s->table_lock);
812 ret = qed_find_cluster(s, &request, pos, &len, &offset);
814 *pnum = len;
815 switch (ret) {
816 case QED_CLUSTER_FOUND:
817 *map = offset | qed_offset_into_cluster(s, pos);
818 status = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
819 *file = bs->file->bs;
820 break;
821 case QED_CLUSTER_ZERO:
822 status = BDRV_BLOCK_ZERO;
823 break;
824 case QED_CLUSTER_L2:
825 case QED_CLUSTER_L1:
826 status = 0;
827 break;
828 default:
829 assert(ret < 0);
830 status = ret;
831 break;
834 qed_unref_l2_cache_entry(request.l2_table);
835 qemu_co_mutex_unlock(&s->table_lock);
837 return status;
840 static BDRVQEDState *acb_to_s(QEDAIOCB *acb)
842 return acb->bs->opaque;
846 * Read from the backing file or zero-fill if no backing file
848 * @s: QED state
849 * @pos: Byte position in device
850 * @qiov: Destination I/O vector
851 * @backing_qiov: Possibly shortened copy of qiov, to be allocated here
852 * @cb: Completion function
853 * @opaque: User data for completion function
855 * This function reads qiov->size bytes starting at pos from the backing file.
856 * If there is no backing file then zeroes are read.
858 static int coroutine_fn qed_read_backing_file(BDRVQEDState *s, uint64_t pos,
859 QEMUIOVector *qiov,
860 QEMUIOVector **backing_qiov)
862 uint64_t backing_length = 0;
863 size_t size;
864 int ret;
866 /* If there is a backing file, get its length. Treat the absence of a
867 * backing file like a zero length backing file.
869 if (s->bs->backing) {
870 int64_t l = bdrv_getlength(s->bs->backing->bs);
871 if (l < 0) {
872 return l;
874 backing_length = l;
877 /* Zero all sectors if reading beyond the end of the backing file */
878 if (pos >= backing_length ||
879 pos + qiov->size > backing_length) {
880 qemu_iovec_memset(qiov, 0, 0, qiov->size);
883 /* Complete now if there are no backing file sectors to read */
884 if (pos >= backing_length) {
885 return 0;
888 /* If the read straddles the end of the backing file, shorten it */
889 size = MIN((uint64_t)backing_length - pos, qiov->size);
891 assert(*backing_qiov == NULL);
892 *backing_qiov = g_new(QEMUIOVector, 1);
893 qemu_iovec_init(*backing_qiov, qiov->niov);
894 qemu_iovec_concat(*backing_qiov, qiov, 0, size);
896 BLKDBG_EVENT(s->bs->file, BLKDBG_READ_BACKING_AIO);
897 ret = bdrv_co_preadv(s->bs->backing, pos, size, *backing_qiov, 0);
898 if (ret < 0) {
899 return ret;
901 return 0;
905 * Copy data from backing file into the image
907 * @s: QED state
908 * @pos: Byte position in device
909 * @len: Number of bytes
910 * @offset: Byte offset in image file
912 static int coroutine_fn qed_copy_from_backing_file(BDRVQEDState *s,
913 uint64_t pos, uint64_t len,
914 uint64_t offset)
916 QEMUIOVector qiov;
917 QEMUIOVector *backing_qiov = NULL;
918 int ret;
920 /* Skip copy entirely if there is no work to do */
921 if (len == 0) {
922 return 0;
925 qemu_iovec_init_buf(&qiov, qemu_blockalign(s->bs, len), len);
927 ret = qed_read_backing_file(s, pos, &qiov, &backing_qiov);
929 if (backing_qiov) {
930 qemu_iovec_destroy(backing_qiov);
931 g_free(backing_qiov);
932 backing_qiov = NULL;
935 if (ret) {
936 goto out;
939 BLKDBG_EVENT(s->bs->file, BLKDBG_COW_WRITE);
940 ret = bdrv_co_pwritev(s->bs->file, offset, qiov.size, &qiov, 0);
941 if (ret < 0) {
942 goto out;
944 ret = 0;
945 out:
946 qemu_vfree(qemu_iovec_buf(&qiov));
947 return ret;
951 * Link one or more contiguous clusters into a table
953 * @s: QED state
954 * @table: L2 table
955 * @index: First cluster index
956 * @n: Number of contiguous clusters
957 * @cluster: First cluster offset
959 * The cluster offset may be an allocated byte offset in the image file, the
960 * zero cluster marker, or the unallocated cluster marker.
962 * Called with table_lock held.
964 static void coroutine_fn qed_update_l2_table(BDRVQEDState *s, QEDTable *table,
965 int index, unsigned int n,
966 uint64_t cluster)
968 int i;
969 for (i = index; i < index + n; i++) {
970 table->offsets[i] = cluster;
971 if (!qed_offset_is_unalloc_cluster(cluster) &&
972 !qed_offset_is_zero_cluster(cluster)) {
973 cluster += s->header.cluster_size;
978 /* Called with table_lock held. */
979 static void coroutine_fn qed_aio_complete(QEDAIOCB *acb)
981 BDRVQEDState *s = acb_to_s(acb);
983 /* Free resources */
984 qemu_iovec_destroy(&acb->cur_qiov);
985 qed_unref_l2_cache_entry(acb->request.l2_table);
987 /* Free the buffer we may have allocated for zero writes */
988 if (acb->flags & QED_AIOCB_ZERO) {
989 qemu_vfree(acb->qiov->iov[0].iov_base);
990 acb->qiov->iov[0].iov_base = NULL;
993 /* Start next allocating write request waiting behind this one. Note that
994 * requests enqueue themselves when they first hit an unallocated cluster
995 * but they wait until the entire request is finished before waking up the
996 * next request in the queue. This ensures that we don't cycle through
997 * requests multiple times but rather finish one at a time completely.
999 if (acb == s->allocating_acb) {
1000 s->allocating_acb = NULL;
1001 if (!qemu_co_queue_empty(&s->allocating_write_reqs)) {
1002 qemu_co_queue_next(&s->allocating_write_reqs);
1003 } else if (s->header.features & QED_F_NEED_CHECK) {
1004 qed_start_need_check_timer(s);
1010 * Update L1 table with new L2 table offset and write it out
1012 * Called with table_lock held.
1014 static int coroutine_fn qed_aio_write_l1_update(QEDAIOCB *acb)
1016 BDRVQEDState *s = acb_to_s(acb);
1017 CachedL2Table *l2_table = acb->request.l2_table;
1018 uint64_t l2_offset = l2_table->offset;
1019 int index, ret;
1021 index = qed_l1_index(s, acb->cur_pos);
1022 s->l1_table->offsets[index] = l2_table->offset;
1024 ret = qed_write_l1_table(s, index, 1);
1026 /* Commit the current L2 table to the cache */
1027 qed_commit_l2_cache_entry(&s->l2_cache, l2_table);
1029 /* This is guaranteed to succeed because we just committed the entry to the
1030 * cache.
1032 acb->request.l2_table = qed_find_l2_cache_entry(&s->l2_cache, l2_offset);
1033 assert(acb->request.l2_table != NULL);
1035 return ret;
1040 * Update L2 table with new cluster offsets and write them out
1042 * Called with table_lock held.
1044 static int coroutine_fn qed_aio_write_l2_update(QEDAIOCB *acb, uint64_t offset)
1046 BDRVQEDState *s = acb_to_s(acb);
1047 bool need_alloc = acb->find_cluster_ret == QED_CLUSTER_L1;
1048 int index, ret;
1050 if (need_alloc) {
1051 qed_unref_l2_cache_entry(acb->request.l2_table);
1052 acb->request.l2_table = qed_new_l2_table(s);
1055 index = qed_l2_index(s, acb->cur_pos);
1056 qed_update_l2_table(s, acb->request.l2_table->table, index, acb->cur_nclusters,
1057 offset);
1059 if (need_alloc) {
1060 /* Write out the whole new L2 table */
1061 ret = qed_write_l2_table(s, &acb->request, 0, s->table_nelems, true);
1062 if (ret) {
1063 return ret;
1065 return qed_aio_write_l1_update(acb);
1066 } else {
1067 /* Write out only the updated part of the L2 table */
1068 ret = qed_write_l2_table(s, &acb->request, index, acb->cur_nclusters,
1069 false);
1070 if (ret) {
1071 return ret;
1074 return 0;
1078 * Write data to the image file
1080 * Called with table_lock *not* held.
1082 static int coroutine_fn qed_aio_write_main(QEDAIOCB *acb)
1084 BDRVQEDState *s = acb_to_s(acb);
1085 uint64_t offset = acb->cur_cluster +
1086 qed_offset_into_cluster(s, acb->cur_pos);
1088 trace_qed_aio_write_main(s, acb, 0, offset, acb->cur_qiov.size);
1090 BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO);
1091 return bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size,
1092 &acb->cur_qiov, 0);
1096 * Populate untouched regions of new data cluster
1098 * Called with table_lock held.
1100 static int coroutine_fn qed_aio_write_cow(QEDAIOCB *acb)
1102 BDRVQEDState *s = acb_to_s(acb);
1103 uint64_t start, len, offset;
1104 int ret;
1106 qemu_co_mutex_unlock(&s->table_lock);
1108 /* Populate front untouched region of new data cluster */
1109 start = qed_start_of_cluster(s, acb->cur_pos);
1110 len = qed_offset_into_cluster(s, acb->cur_pos);
1112 trace_qed_aio_write_prefill(s, acb, start, len, acb->cur_cluster);
1113 ret = qed_copy_from_backing_file(s, start, len, acb->cur_cluster);
1114 if (ret < 0) {
1115 goto out;
1118 /* Populate back untouched region of new data cluster */
1119 start = acb->cur_pos + acb->cur_qiov.size;
1120 len = qed_start_of_cluster(s, start + s->header.cluster_size - 1) - start;
1121 offset = acb->cur_cluster +
1122 qed_offset_into_cluster(s, acb->cur_pos) +
1123 acb->cur_qiov.size;
1125 trace_qed_aio_write_postfill(s, acb, start, len, offset);
1126 ret = qed_copy_from_backing_file(s, start, len, offset);
1127 if (ret < 0) {
1128 goto out;
1131 ret = qed_aio_write_main(acb);
1132 if (ret < 0) {
1133 goto out;
1136 if (s->bs->backing) {
1138 * Flush new data clusters before updating the L2 table
1140 * This flush is necessary when a backing file is in use. A crash
1141 * during an allocating write could result in empty clusters in the
1142 * image. If the write only touched a subregion of the cluster,
1143 * then backing image sectors have been lost in the untouched
1144 * region. The solution is to flush after writing a new data
1145 * cluster and before updating the L2 table.
1147 ret = bdrv_co_flush(s->bs->file->bs);
1150 out:
1151 qemu_co_mutex_lock(&s->table_lock);
1152 return ret;
1156 * Check if the QED_F_NEED_CHECK bit should be set during allocating write
1158 static bool qed_should_set_need_check(BDRVQEDState *s)
1160 /* The flush before L2 update path ensures consistency */
1161 if (s->bs->backing) {
1162 return false;
1165 return !(s->header.features & QED_F_NEED_CHECK);
1169 * Write new data cluster
1171 * @acb: Write request
1172 * @len: Length in bytes
1174 * This path is taken when writing to previously unallocated clusters.
1176 * Called with table_lock held.
1178 static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len)
1180 BDRVQEDState *s = acb_to_s(acb);
1181 int ret;
1183 /* Cancel timer when the first allocating request comes in */
1184 if (s->allocating_acb == NULL) {
1185 qed_cancel_need_check_timer(s);
1188 /* Freeze this request if another allocating write is in progress */
1189 if (s->allocating_acb != acb || s->allocating_write_reqs_plugged) {
1190 if (s->allocating_acb != NULL) {
1191 qemu_co_queue_wait(&s->allocating_write_reqs, &s->table_lock);
1192 assert(s->allocating_acb == NULL);
1194 s->allocating_acb = acb;
1195 return -EAGAIN; /* start over with looking up table entries */
1198 acb->cur_nclusters = qed_bytes_to_clusters(s,
1199 qed_offset_into_cluster(s, acb->cur_pos) + len);
1200 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
1202 if (acb->flags & QED_AIOCB_ZERO) {
1203 /* Skip ahead if the clusters are already zero */
1204 if (acb->find_cluster_ret == QED_CLUSTER_ZERO) {
1205 return 0;
1207 acb->cur_cluster = 1;
1208 } else {
1209 acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters);
1212 if (qed_should_set_need_check(s)) {
1213 s->header.features |= QED_F_NEED_CHECK;
1214 ret = qed_write_header(s);
1215 if (ret < 0) {
1216 return ret;
1220 if (!(acb->flags & QED_AIOCB_ZERO)) {
1221 ret = qed_aio_write_cow(acb);
1222 if (ret < 0) {
1223 return ret;
1227 return qed_aio_write_l2_update(acb, acb->cur_cluster);
1231 * Write data cluster in place
1233 * @acb: Write request
1234 * @offset: Cluster offset in bytes
1235 * @len: Length in bytes
1237 * This path is taken when writing to already allocated clusters.
1239 * Called with table_lock held.
1241 static int coroutine_fn qed_aio_write_inplace(QEDAIOCB *acb, uint64_t offset,
1242 size_t len)
1244 BDRVQEDState *s = acb_to_s(acb);
1245 int r;
1247 qemu_co_mutex_unlock(&s->table_lock);
1249 /* Allocate buffer for zero writes */
1250 if (acb->flags & QED_AIOCB_ZERO) {
1251 struct iovec *iov = acb->qiov->iov;
1253 if (!iov->iov_base) {
1254 iov->iov_base = qemu_try_blockalign(acb->bs, iov->iov_len);
1255 if (iov->iov_base == NULL) {
1256 r = -ENOMEM;
1257 goto out;
1259 memset(iov->iov_base, 0, iov->iov_len);
1263 /* Calculate the I/O vector */
1264 acb->cur_cluster = offset;
1265 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
1267 /* Do the actual write. */
1268 r = qed_aio_write_main(acb);
1269 out:
1270 qemu_co_mutex_lock(&s->table_lock);
1271 return r;
1275 * Write data cluster
1277 * @opaque: Write request
1278 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1
1279 * @offset: Cluster offset in bytes
1280 * @len: Length in bytes
1282 * Called with table_lock held.
1284 static int coroutine_fn qed_aio_write_data(void *opaque, int ret,
1285 uint64_t offset, size_t len)
1287 QEDAIOCB *acb = opaque;
1289 trace_qed_aio_write_data(acb_to_s(acb), acb, ret, offset, len);
1291 acb->find_cluster_ret = ret;
1293 switch (ret) {
1294 case QED_CLUSTER_FOUND:
1295 return qed_aio_write_inplace(acb, offset, len);
1297 case QED_CLUSTER_L2:
1298 case QED_CLUSTER_L1:
1299 case QED_CLUSTER_ZERO:
1300 return qed_aio_write_alloc(acb, len);
1302 default:
1303 g_assert_not_reached();
1308 * Read data cluster
1310 * @opaque: Read request
1311 * @ret: QED_CLUSTER_FOUND, QED_CLUSTER_L2 or QED_CLUSTER_L1
1312 * @offset: Cluster offset in bytes
1313 * @len: Length in bytes
1315 * Called with table_lock held.
1317 static int coroutine_fn qed_aio_read_data(void *opaque, int ret,
1318 uint64_t offset, size_t len)
1320 QEDAIOCB *acb = opaque;
1321 BDRVQEDState *s = acb_to_s(acb);
1322 BlockDriverState *bs = acb->bs;
1323 int r;
1325 qemu_co_mutex_unlock(&s->table_lock);
1327 /* Adjust offset into cluster */
1328 offset += qed_offset_into_cluster(s, acb->cur_pos);
1330 trace_qed_aio_read_data(s, acb, ret, offset, len);
1332 qemu_iovec_concat(&acb->cur_qiov, acb->qiov, acb->qiov_offset, len);
1334 /* Handle zero cluster and backing file reads, otherwise read
1335 * data cluster directly.
1337 if (ret == QED_CLUSTER_ZERO) {
1338 qemu_iovec_memset(&acb->cur_qiov, 0, 0, acb->cur_qiov.size);
1339 r = 0;
1340 } else if (ret != QED_CLUSTER_FOUND) {
1341 r = qed_read_backing_file(s, acb->cur_pos, &acb->cur_qiov,
1342 &acb->backing_qiov);
1343 } else {
1344 BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
1345 r = bdrv_co_preadv(bs->file, offset, acb->cur_qiov.size,
1346 &acb->cur_qiov, 0);
1349 qemu_co_mutex_lock(&s->table_lock);
1350 return r;
1354 * Begin next I/O or complete the request
1356 static int coroutine_fn qed_aio_next_io(QEDAIOCB *acb)
1358 BDRVQEDState *s = acb_to_s(acb);
1359 uint64_t offset;
1360 size_t len;
1361 int ret;
1363 qemu_co_mutex_lock(&s->table_lock);
1364 while (1) {
1365 trace_qed_aio_next_io(s, acb, 0, acb->cur_pos + acb->cur_qiov.size);
1367 if (acb->backing_qiov) {
1368 qemu_iovec_destroy(acb->backing_qiov);
1369 g_free(acb->backing_qiov);
1370 acb->backing_qiov = NULL;
1373 acb->qiov_offset += acb->cur_qiov.size;
1374 acb->cur_pos += acb->cur_qiov.size;
1375 qemu_iovec_reset(&acb->cur_qiov);
1377 /* Complete request */
1378 if (acb->cur_pos >= acb->end_pos) {
1379 ret = 0;
1380 break;
1383 /* Find next cluster and start I/O */
1384 len = acb->end_pos - acb->cur_pos;
1385 ret = qed_find_cluster(s, &acb->request, acb->cur_pos, &len, &offset);
1386 if (ret < 0) {
1387 break;
1390 if (acb->flags & QED_AIOCB_WRITE) {
1391 ret = qed_aio_write_data(acb, ret, offset, len);
1392 } else {
1393 ret = qed_aio_read_data(acb, ret, offset, len);
1396 if (ret < 0 && ret != -EAGAIN) {
1397 break;
1401 trace_qed_aio_complete(s, acb, ret);
1402 qed_aio_complete(acb);
1403 qemu_co_mutex_unlock(&s->table_lock);
1404 return ret;
1407 static int coroutine_fn qed_co_request(BlockDriverState *bs, int64_t sector_num,
1408 QEMUIOVector *qiov, int nb_sectors,
1409 int flags)
1411 QEDAIOCB acb = {
1412 .bs = bs,
1413 .cur_pos = (uint64_t) sector_num * BDRV_SECTOR_SIZE,
1414 .end_pos = (sector_num + nb_sectors) * BDRV_SECTOR_SIZE,
1415 .qiov = qiov,
1416 .flags = flags,
1418 qemu_iovec_init(&acb.cur_qiov, qiov->niov);
1420 trace_qed_aio_setup(bs->opaque, &acb, sector_num, nb_sectors, NULL, flags);
1422 /* Start request */
1423 return qed_aio_next_io(&acb);
1426 static int coroutine_fn bdrv_qed_co_readv(BlockDriverState *bs,
1427 int64_t sector_num, int nb_sectors,
1428 QEMUIOVector *qiov)
1430 return qed_co_request(bs, sector_num, qiov, nb_sectors, 0);
1433 static int coroutine_fn bdrv_qed_co_writev(BlockDriverState *bs,
1434 int64_t sector_num, int nb_sectors,
1435 QEMUIOVector *qiov, int flags)
1437 assert(!flags);
1438 return qed_co_request(bs, sector_num, qiov, nb_sectors, QED_AIOCB_WRITE);
1441 static int coroutine_fn bdrv_qed_co_pwrite_zeroes(BlockDriverState *bs,
1442 int64_t offset,
1443 int bytes,
1444 BdrvRequestFlags flags)
1446 BDRVQEDState *s = bs->opaque;
1449 * Zero writes start without an I/O buffer. If a buffer becomes necessary
1450 * then it will be allocated during request processing.
1452 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, bytes);
1454 /* Fall back if the request is not aligned */
1455 if (qed_offset_into_cluster(s, offset) ||
1456 qed_offset_into_cluster(s, bytes)) {
1457 return -ENOTSUP;
1460 return qed_co_request(bs, offset >> BDRV_SECTOR_BITS, &qiov,
1461 bytes >> BDRV_SECTOR_BITS,
1462 QED_AIOCB_WRITE | QED_AIOCB_ZERO);
1465 static int coroutine_fn bdrv_qed_co_truncate(BlockDriverState *bs,
1466 int64_t offset,
1467 bool exact,
1468 PreallocMode prealloc,
1469 Error **errp)
1471 BDRVQEDState *s = bs->opaque;
1472 uint64_t old_image_size;
1473 int ret;
1475 if (prealloc != PREALLOC_MODE_OFF) {
1476 error_setg(errp, "Unsupported preallocation mode '%s'",
1477 PreallocMode_str(prealloc));
1478 return -ENOTSUP;
1481 if (!qed_is_image_size_valid(offset, s->header.cluster_size,
1482 s->header.table_size)) {
1483 error_setg(errp, "Invalid image size specified");
1484 return -EINVAL;
1487 if ((uint64_t)offset < s->header.image_size) {
1488 error_setg(errp, "Shrinking images is currently not supported");
1489 return -ENOTSUP;
1492 old_image_size = s->header.image_size;
1493 s->header.image_size = offset;
1494 ret = qed_write_header_sync(s);
1495 if (ret < 0) {
1496 s->header.image_size = old_image_size;
1497 error_setg_errno(errp, -ret, "Failed to update the image size");
1499 return ret;
1502 static int64_t bdrv_qed_getlength(BlockDriverState *bs)
1504 BDRVQEDState *s = bs->opaque;
1505 return s->header.image_size;
1508 static int bdrv_qed_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1510 BDRVQEDState *s = bs->opaque;
1512 memset(bdi, 0, sizeof(*bdi));
1513 bdi->cluster_size = s->header.cluster_size;
1514 bdi->is_dirty = s->header.features & QED_F_NEED_CHECK;
1515 bdi->unallocated_blocks_are_zero = true;
1516 return 0;
1519 static int bdrv_qed_change_backing_file(BlockDriverState *bs,
1520 const char *backing_file,
1521 const char *backing_fmt)
1523 BDRVQEDState *s = bs->opaque;
1524 QEDHeader new_header, le_header;
1525 void *buffer;
1526 size_t buffer_len, backing_file_len;
1527 int ret;
1529 /* Refuse to set backing filename if unknown compat feature bits are
1530 * active. If the image uses an unknown compat feature then we may not
1531 * know the layout of data following the header structure and cannot safely
1532 * add a new string.
1534 if (backing_file && (s->header.compat_features &
1535 ~QED_COMPAT_FEATURE_MASK)) {
1536 return -ENOTSUP;
1539 memcpy(&new_header, &s->header, sizeof(new_header));
1541 new_header.features &= ~(QED_F_BACKING_FILE |
1542 QED_F_BACKING_FORMAT_NO_PROBE);
1544 /* Adjust feature flags */
1545 if (backing_file) {
1546 new_header.features |= QED_F_BACKING_FILE;
1548 if (qed_fmt_is_raw(backing_fmt)) {
1549 new_header.features |= QED_F_BACKING_FORMAT_NO_PROBE;
1553 /* Calculate new header size */
1554 backing_file_len = 0;
1556 if (backing_file) {
1557 backing_file_len = strlen(backing_file);
1560 buffer_len = sizeof(new_header);
1561 new_header.backing_filename_offset = buffer_len;
1562 new_header.backing_filename_size = backing_file_len;
1563 buffer_len += backing_file_len;
1565 /* Make sure we can rewrite header without failing */
1566 if (buffer_len > new_header.header_size * new_header.cluster_size) {
1567 return -ENOSPC;
1570 /* Prepare new header */
1571 buffer = g_malloc(buffer_len);
1573 qed_header_cpu_to_le(&new_header, &le_header);
1574 memcpy(buffer, &le_header, sizeof(le_header));
1575 buffer_len = sizeof(le_header);
1577 if (backing_file) {
1578 memcpy(buffer + buffer_len, backing_file, backing_file_len);
1579 buffer_len += backing_file_len;
1582 /* Write new header */
1583 ret = bdrv_pwrite_sync(bs->file, 0, buffer, buffer_len);
1584 g_free(buffer);
1585 if (ret == 0) {
1586 memcpy(&s->header, &new_header, sizeof(new_header));
1588 return ret;
1591 static void coroutine_fn bdrv_qed_co_invalidate_cache(BlockDriverState *bs,
1592 Error **errp)
1594 BDRVQEDState *s = bs->opaque;
1595 Error *local_err = NULL;
1596 int ret;
1598 bdrv_qed_close(bs);
1600 bdrv_qed_init_state(bs);
1601 qemu_co_mutex_lock(&s->table_lock);
1602 ret = bdrv_qed_do_open(bs, NULL, bs->open_flags, &local_err);
1603 qemu_co_mutex_unlock(&s->table_lock);
1604 if (local_err) {
1605 error_propagate_prepend(errp, local_err,
1606 "Could not reopen qed layer: ");
1607 return;
1608 } else if (ret < 0) {
1609 error_setg_errno(errp, -ret, "Could not reopen qed layer");
1610 return;
1614 static int coroutine_fn bdrv_qed_co_check(BlockDriverState *bs,
1615 BdrvCheckResult *result,
1616 BdrvCheckMode fix)
1618 BDRVQEDState *s = bs->opaque;
1619 int ret;
1621 qemu_co_mutex_lock(&s->table_lock);
1622 ret = qed_check(s, result, !!fix);
1623 qemu_co_mutex_unlock(&s->table_lock);
1625 return ret;
1628 static QemuOptsList qed_create_opts = {
1629 .name = "qed-create-opts",
1630 .head = QTAILQ_HEAD_INITIALIZER(qed_create_opts.head),
1631 .desc = {
1633 .name = BLOCK_OPT_SIZE,
1634 .type = QEMU_OPT_SIZE,
1635 .help = "Virtual disk size"
1638 .name = BLOCK_OPT_BACKING_FILE,
1639 .type = QEMU_OPT_STRING,
1640 .help = "File name of a base image"
1643 .name = BLOCK_OPT_BACKING_FMT,
1644 .type = QEMU_OPT_STRING,
1645 .help = "Image format of the base image"
1648 .name = BLOCK_OPT_CLUSTER_SIZE,
1649 .type = QEMU_OPT_SIZE,
1650 .help = "Cluster size (in bytes)",
1651 .def_value_str = stringify(QED_DEFAULT_CLUSTER_SIZE)
1654 .name = BLOCK_OPT_TABLE_SIZE,
1655 .type = QEMU_OPT_SIZE,
1656 .help = "L1/L2 table size (in clusters)"
1658 { /* end of list */ }
1662 static BlockDriver bdrv_qed = {
1663 .format_name = "qed",
1664 .instance_size = sizeof(BDRVQEDState),
1665 .create_opts = &qed_create_opts,
1666 .supports_backing = true,
1668 .bdrv_probe = bdrv_qed_probe,
1669 .bdrv_open = bdrv_qed_open,
1670 .bdrv_close = bdrv_qed_close,
1671 .bdrv_reopen_prepare = bdrv_qed_reopen_prepare,
1672 .bdrv_child_perm = bdrv_format_default_perms,
1673 .bdrv_co_create = bdrv_qed_co_create,
1674 .bdrv_co_create_opts = bdrv_qed_co_create_opts,
1675 .bdrv_has_zero_init = bdrv_has_zero_init_1,
1676 .bdrv_has_zero_init_truncate = bdrv_has_zero_init_1,
1677 .bdrv_co_block_status = bdrv_qed_co_block_status,
1678 .bdrv_co_readv = bdrv_qed_co_readv,
1679 .bdrv_co_writev = bdrv_qed_co_writev,
1680 .bdrv_co_pwrite_zeroes = bdrv_qed_co_pwrite_zeroes,
1681 .bdrv_co_truncate = bdrv_qed_co_truncate,
1682 .bdrv_getlength = bdrv_qed_getlength,
1683 .bdrv_get_info = bdrv_qed_get_info,
1684 .bdrv_refresh_limits = bdrv_qed_refresh_limits,
1685 .bdrv_change_backing_file = bdrv_qed_change_backing_file,
1686 .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache,
1687 .bdrv_co_check = bdrv_qed_co_check,
1688 .bdrv_detach_aio_context = bdrv_qed_detach_aio_context,
1689 .bdrv_attach_aio_context = bdrv_qed_attach_aio_context,
1690 .bdrv_co_drain_begin = bdrv_qed_co_drain_begin,
1693 static void bdrv_qed_init(void)
1695 bdrv_register(&bdrv_qed);
1698 block_init(bdrv_qed_init);