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-rw-r--r--block/qcow2.c6032
1 files changed, 6032 insertions, 0 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
new file mode 100644
index 000000000..d50901675
--- /dev/null
+++ b/block/qcow2.c
@@ -0,0 +1,6032 @@
+/*
+ * Block driver for the QCOW version 2 format
+ *
+ * Copyright (c) 2004-2006 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+
+#include "block/qdict.h"
+#include "sysemu/block-backend.h"
+#include "qemu/main-loop.h"
+#include "qemu/module.h"
+#include "qcow2.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "qapi/qapi-events-block-core.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/qmp/qstring.h"
+#include "trace.h"
+#include "qemu/option_int.h"
+#include "qemu/cutils.h"
+#include "qemu/bswap.h"
+#include "qapi/qobject-input-visitor.h"
+#include "qapi/qapi-visit-block-core.h"
+#include "crypto.h"
+#include "block/aio_task.h"
+
+/*
+ Differences with QCOW:
+
+ - Support for multiple incremental snapshots.
+ - Memory management by reference counts.
+ - Clusters which have a reference count of one have the bit
+ QCOW_OFLAG_COPIED to optimize write performance.
+ - Size of compressed clusters is stored in sectors to reduce bit usage
+ in the cluster offsets.
+ - Support for storing additional data (such as the VM state) in the
+ snapshots.
+ - If a backing store is used, the cluster size is not constrained
+ (could be backported to QCOW).
+ - L2 tables have always a size of one cluster.
+*/
+
+
+typedef struct {
+ uint32_t magic;
+ uint32_t len;
+} QEMU_PACKED QCowExtension;
+
+#define QCOW2_EXT_MAGIC_END 0
+#define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xe2792aca
+#define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857
+#define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77
+#define QCOW2_EXT_MAGIC_BITMAPS 0x23852875
+#define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441
+
+static int coroutine_fn
+qcow2_co_preadv_compressed(BlockDriverState *bs,
+ uint64_t l2_entry,
+ uint64_t offset,
+ uint64_t bytes,
+ QEMUIOVector *qiov,
+ size_t qiov_offset);
+
+static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename)
+{
+ const QCowHeader *cow_header = (const void *)buf;
+
+ if (buf_size >= sizeof(QCowHeader) &&
+ be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
+ be32_to_cpu(cow_header->version) >= 2)
+ return 100;
+ else
+ return 0;
+}
+
+
+static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset,
+ uint8_t *buf, size_t buflen,
+ void *opaque, Error **errp)
+{
+ BlockDriverState *bs = opaque;
+ BDRVQcow2State *s = bs->opaque;
+ ssize_t ret;
+
+ if ((offset + buflen) > s->crypto_header.length) {
+ error_setg(errp, "Request for data outside of extension header");
+ return -1;
+ }
+
+ ret = bdrv_pread(bs->file,
+ s->crypto_header.offset + offset, buf, buflen);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read encryption header");
+ return -1;
+ }
+ return ret;
+}
+
+
+static ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen,
+ void *opaque, Error **errp)
+{
+ BlockDriverState *bs = opaque;
+ BDRVQcow2State *s = bs->opaque;
+ int64_t ret;
+ int64_t clusterlen;
+
+ ret = qcow2_alloc_clusters(bs, headerlen);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Cannot allocate cluster for LUKS header size %zu",
+ headerlen);
+ return -1;
+ }
+
+ s->crypto_header.length = headerlen;
+ s->crypto_header.offset = ret;
+
+ /*
+ * Zero fill all space in cluster so it has predictable
+ * content, as we may not initialize some regions of the
+ * header (eg only 1 out of 8 key slots will be initialized)
+ */
+ clusterlen = size_to_clusters(s, headerlen) * s->cluster_size;
+ assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0);
+ ret = bdrv_pwrite_zeroes(bs->file,
+ ret,
+ clusterlen, 0);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not zero fill encryption header");
+ return -1;
+ }
+
+ return ret;
+}
+
+
+static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset,
+ const uint8_t *buf, size_t buflen,
+ void *opaque, Error **errp)
+{
+ BlockDriverState *bs = opaque;
+ BDRVQcow2State *s = bs->opaque;
+ ssize_t ret;
+
+ if ((offset + buflen) > s->crypto_header.length) {
+ error_setg(errp, "Request for data outside of extension header");
+ return -1;
+ }
+
+ ret = bdrv_pwrite(bs->file,
+ s->crypto_header.offset + offset, buf, buflen);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read encryption header");
+ return -1;
+ }
+ return ret;
+}
+
+static QDict*
+qcow2_extract_crypto_opts(QemuOpts *opts, const char *fmt, Error **errp)
+{
+ QDict *cryptoopts_qdict;
+ QDict *opts_qdict;
+
+ /* Extract "encrypt." options into a qdict */
+ opts_qdict = qemu_opts_to_qdict(opts, NULL);
+ qdict_extract_subqdict(opts_qdict, &cryptoopts_qdict, "encrypt.");
+ qobject_unref(opts_qdict);
+ qdict_put_str(cryptoopts_qdict, "format", fmt);
+ return cryptoopts_qdict;
+}
+
+/*
+ * read qcow2 extension and fill bs
+ * start reading from start_offset
+ * finish reading upon magic of value 0 or when end_offset reached
+ * unknown magic is skipped (future extension this version knows nothing about)
+ * return 0 upon success, non-0 otherwise
+ */
+static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset,
+ uint64_t end_offset, void **p_feature_table,
+ int flags, bool *need_update_header,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ QCowExtension ext;
+ uint64_t offset;
+ int ret;
+ Qcow2BitmapHeaderExt bitmaps_ext;
+
+ if (need_update_header != NULL) {
+ *need_update_header = false;
+ }
+
+#ifdef DEBUG_EXT
+ printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
+#endif
+ offset = start_offset;
+ while (offset < end_offset) {
+
+#ifdef DEBUG_EXT
+ /* Sanity check */
+ if (offset > s->cluster_size)
+ printf("qcow2_read_extension: suspicious offset %lu\n", offset);
+
+ printf("attempting to read extended header in offset %lu\n", offset);
+#endif
+
+ ret = bdrv_pread(bs->file, offset, &ext, sizeof(ext));
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: "
+ "pread fail from offset %" PRIu64, offset);
+ return 1;
+ }
+ ext.magic = be32_to_cpu(ext.magic);
+ ext.len = be32_to_cpu(ext.len);
+ offset += sizeof(ext);
+#ifdef DEBUG_EXT
+ printf("ext.magic = 0x%x\n", ext.magic);
+#endif
+ if (offset > end_offset || ext.len > end_offset - offset) {
+ error_setg(errp, "Header extension too large");
+ return -EINVAL;
+ }
+
+ switch (ext.magic) {
+ case QCOW2_EXT_MAGIC_END:
+ return 0;
+
+ case QCOW2_EXT_MAGIC_BACKING_FORMAT:
+ if (ext.len >= sizeof(bs->backing_format)) {
+ error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32
+ " too large (>=%zu)", ext.len,
+ sizeof(bs->backing_format));
+ return 2;
+ }
+ ret = bdrv_pread(bs->file, offset, bs->backing_format, ext.len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "ERROR: ext_backing_format: "
+ "Could not read format name");
+ return 3;
+ }
+ bs->backing_format[ext.len] = '\0';
+ s->image_backing_format = g_strdup(bs->backing_format);
+#ifdef DEBUG_EXT
+ printf("Qcow2: Got format extension %s\n", bs->backing_format);
+#endif
+ break;
+
+ case QCOW2_EXT_MAGIC_FEATURE_TABLE:
+ if (p_feature_table != NULL) {
+ void *feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature));
+ ret = bdrv_pread(bs->file, offset , feature_table, ext.len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "ERROR: ext_feature_table: "
+ "Could not read table");
+ return ret;
+ }
+
+ *p_feature_table = feature_table;
+ }
+ break;
+
+ case QCOW2_EXT_MAGIC_CRYPTO_HEADER: {
+ unsigned int cflags = 0;
+ if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
+ error_setg(errp, "CRYPTO header extension only "
+ "expected with LUKS encryption method");
+ return -EINVAL;
+ }
+ if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) {
+ error_setg(errp, "CRYPTO header extension size %u, "
+ "but expected size %zu", ext.len,
+ sizeof(Qcow2CryptoHeaderExtension));
+ return -EINVAL;
+ }
+
+ ret = bdrv_pread(bs->file, offset, &s->crypto_header, ext.len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Unable to read CRYPTO header extension");
+ return ret;
+ }
+ s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset);
+ s->crypto_header.length = be64_to_cpu(s->crypto_header.length);
+
+ if ((s->crypto_header.offset % s->cluster_size) != 0) {
+ error_setg(errp, "Encryption header offset '%" PRIu64 "' is "
+ "not a multiple of cluster size '%u'",
+ s->crypto_header.offset, s->cluster_size);
+ return -EINVAL;
+ }
+
+ if (flags & BDRV_O_NO_IO) {
+ cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
+ }
+ s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.",
+ qcow2_crypto_hdr_read_func,
+ bs, cflags, QCOW2_MAX_THREADS, errp);
+ if (!s->crypto) {
+ return -EINVAL;
+ }
+ } break;
+
+ case QCOW2_EXT_MAGIC_BITMAPS:
+ if (ext.len != sizeof(bitmaps_ext)) {
+ error_setg_errno(errp, -ret, "bitmaps_ext: "
+ "Invalid extension length");
+ return -EINVAL;
+ }
+
+ if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) {
+ if (s->qcow_version < 3) {
+ /* Let's be a bit more specific */
+ warn_report("This qcow2 v2 image contains bitmaps, but "
+ "they may have been modified by a program "
+ "without persistent bitmap support; so now "
+ "they must all be considered inconsistent");
+ } else {
+ warn_report("a program lacking bitmap support "
+ "modified this file, so all bitmaps are now "
+ "considered inconsistent");
+ }
+ error_printf("Some clusters may be leaked, "
+ "run 'qemu-img check -r' on the image "
+ "file to fix.");
+ if (need_update_header != NULL) {
+ /* Updating is needed to drop invalid bitmap extension. */
+ *need_update_header = true;
+ }
+ break;
+ }
+
+ ret = bdrv_pread(bs->file, offset, &bitmaps_ext, ext.len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "bitmaps_ext: "
+ "Could not read ext header");
+ return ret;
+ }
+
+ if (bitmaps_ext.reserved32 != 0) {
+ error_setg_errno(errp, -ret, "bitmaps_ext: "
+ "Reserved field is not zero");
+ return -EINVAL;
+ }
+
+ bitmaps_ext.nb_bitmaps = be32_to_cpu(bitmaps_ext.nb_bitmaps);
+ bitmaps_ext.bitmap_directory_size =
+ be64_to_cpu(bitmaps_ext.bitmap_directory_size);
+ bitmaps_ext.bitmap_directory_offset =
+ be64_to_cpu(bitmaps_ext.bitmap_directory_offset);
+
+ if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) {
+ error_setg(errp,
+ "bitmaps_ext: Image has %" PRIu32 " bitmaps, "
+ "exceeding the QEMU supported maximum of %d",
+ bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS);
+ return -EINVAL;
+ }
+
+ if (bitmaps_ext.nb_bitmaps == 0) {
+ error_setg(errp, "found bitmaps extension with zero bitmaps");
+ return -EINVAL;
+ }
+
+ if (offset_into_cluster(s, bitmaps_ext.bitmap_directory_offset)) {
+ error_setg(errp, "bitmaps_ext: "
+ "invalid bitmap directory offset");
+ return -EINVAL;
+ }
+
+ if (bitmaps_ext.bitmap_directory_size >
+ QCOW2_MAX_BITMAP_DIRECTORY_SIZE) {
+ error_setg(errp, "bitmaps_ext: "
+ "bitmap directory size (%" PRIu64 ") exceeds "
+ "the maximum supported size (%d)",
+ bitmaps_ext.bitmap_directory_size,
+ QCOW2_MAX_BITMAP_DIRECTORY_SIZE);
+ return -EINVAL;
+ }
+
+ s->nb_bitmaps = bitmaps_ext.nb_bitmaps;
+ s->bitmap_directory_offset =
+ bitmaps_ext.bitmap_directory_offset;
+ s->bitmap_directory_size =
+ bitmaps_ext.bitmap_directory_size;
+
+#ifdef DEBUG_EXT
+ printf("Qcow2: Got bitmaps extension: "
+ "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n",
+ s->bitmap_directory_offset, s->nb_bitmaps);
+#endif
+ break;
+
+ case QCOW2_EXT_MAGIC_DATA_FILE:
+ {
+ s->image_data_file = g_malloc0(ext.len + 1);
+ ret = bdrv_pread(bs->file, offset, s->image_data_file, ext.len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "ERROR: Could not read data file name");
+ return ret;
+ }
+#ifdef DEBUG_EXT
+ printf("Qcow2: Got external data file %s\n", s->image_data_file);
+#endif
+ break;
+ }
+
+ default:
+ /* unknown magic - save it in case we need to rewrite the header */
+ /* If you add a new feature, make sure to also update the fast
+ * path of qcow2_make_empty() to deal with it. */
+ {
+ Qcow2UnknownHeaderExtension *uext;
+
+ uext = g_malloc0(sizeof(*uext) + ext.len);
+ uext->magic = ext.magic;
+ uext->len = ext.len;
+ QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next);
+
+ ret = bdrv_pread(bs->file, offset , uext->data, uext->len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "ERROR: unknown extension: "
+ "Could not read data");
+ return ret;
+ }
+ }
+ break;
+ }
+
+ offset += ((ext.len + 7) & ~7);
+ }
+
+ return 0;
+}
+
+static void cleanup_unknown_header_ext(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ Qcow2UnknownHeaderExtension *uext, *next;
+
+ QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) {
+ QLIST_REMOVE(uext, next);
+ g_free(uext);
+ }
+}
+
+static void report_unsupported_feature(Error **errp, Qcow2Feature *table,
+ uint64_t mask)
+{
+ g_autoptr(GString) features = g_string_sized_new(60);
+
+ while (table && table->name[0] != '\0') {
+ if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) {
+ if (mask & (1ULL << table->bit)) {
+ if (features->len > 0) {
+ g_string_append(features, ", ");
+ }
+ g_string_append_printf(features, "%.46s", table->name);
+ mask &= ~(1ULL << table->bit);
+ }
+ }
+ table++;
+ }
+
+ if (mask) {
+ if (features->len > 0) {
+ g_string_append(features, ", ");
+ }
+ g_string_append_printf(features,
+ "Unknown incompatible feature: %" PRIx64, mask);
+ }
+
+ error_setg(errp, "Unsupported qcow2 feature(s): %s", features->str);
+}
+
+/*
+ * Sets the dirty bit and flushes afterwards if necessary.
+ *
+ * The incompatible_features bit is only set if the image file header was
+ * updated successfully. Therefore it is not required to check the return
+ * value of this function.
+ */
+int qcow2_mark_dirty(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint64_t val;
+ int ret;
+
+ assert(s->qcow_version >= 3);
+
+ if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
+ return 0; /* already dirty */
+ }
+
+ val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY);
+ ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features),
+ &val, sizeof(val));
+ if (ret < 0) {
+ return ret;
+ }
+ ret = bdrv_flush(bs->file->bs);
+ if (ret < 0) {
+ return ret;
+ }
+
+ /* Only treat image as dirty if the header was updated successfully */
+ s->incompatible_features |= QCOW2_INCOMPAT_DIRTY;
+ return 0;
+}
+
+/*
+ * Clears the dirty bit and flushes before if necessary. Only call this
+ * function when there are no pending requests, it does not guard against
+ * concurrent requests dirtying the image.
+ */
+static int qcow2_mark_clean(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+
+ if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
+ int ret;
+
+ s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY;
+
+ ret = qcow2_flush_caches(bs);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return qcow2_update_header(bs);
+ }
+ return 0;
+}
+
+/*
+ * Marks the image as corrupt.
+ */
+int qcow2_mark_corrupt(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+
+ s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT;
+ return qcow2_update_header(bs);
+}
+
+/*
+ * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes
+ * before if necessary.
+ */
+int qcow2_mark_consistent(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+
+ if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) {
+ int ret = qcow2_flush_caches(bs);
+ if (ret < 0) {
+ return ret;
+ }
+
+ s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT;
+ return qcow2_update_header(bs);
+ }
+ return 0;
+}
+
+static void qcow2_add_check_result(BdrvCheckResult *out,
+ const BdrvCheckResult *src,
+ bool set_allocation_info)
+{
+ out->corruptions += src->corruptions;
+ out->leaks += src->leaks;
+ out->check_errors += src->check_errors;
+ out->corruptions_fixed += src->corruptions_fixed;
+ out->leaks_fixed += src->leaks_fixed;
+
+ if (set_allocation_info) {
+ out->image_end_offset = src->image_end_offset;
+ out->bfi = src->bfi;
+ }
+}
+
+static int coroutine_fn qcow2_co_check_locked(BlockDriverState *bs,
+ BdrvCheckResult *result,
+ BdrvCheckMode fix)
+{
+ BdrvCheckResult snapshot_res = {};
+ BdrvCheckResult refcount_res = {};
+ int ret;
+
+ memset(result, 0, sizeof(*result));
+
+ ret = qcow2_check_read_snapshot_table(bs, &snapshot_res, fix);
+ if (ret < 0) {
+ qcow2_add_check_result(result, &snapshot_res, false);
+ return ret;
+ }
+
+ ret = qcow2_check_refcounts(bs, &refcount_res, fix);
+ qcow2_add_check_result(result, &refcount_res, true);
+ if (ret < 0) {
+ qcow2_add_check_result(result, &snapshot_res, false);
+ return ret;
+ }
+
+ ret = qcow2_check_fix_snapshot_table(bs, &snapshot_res, fix);
+ qcow2_add_check_result(result, &snapshot_res, false);
+ if (ret < 0) {
+ return ret;
+ }
+
+ if (fix && result->check_errors == 0 && result->corruptions == 0) {
+ ret = qcow2_mark_clean(bs);
+ if (ret < 0) {
+ return ret;
+ }
+ return qcow2_mark_consistent(bs);
+ }
+ return ret;
+}
+
+static int coroutine_fn qcow2_co_check(BlockDriverState *bs,
+ BdrvCheckResult *result,
+ BdrvCheckMode fix)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int ret;
+
+ qemu_co_mutex_lock(&s->lock);
+ ret = qcow2_co_check_locked(bs, result, fix);
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+}
+
+int qcow2_validate_table(BlockDriverState *bs, uint64_t offset,
+ uint64_t entries, size_t entry_len,
+ int64_t max_size_bytes, const char *table_name,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+
+ if (entries > max_size_bytes / entry_len) {
+ error_setg(errp, "%s too large", table_name);
+ return -EFBIG;
+ }
+
+ /* Use signed INT64_MAX as the maximum even for uint64_t header fields,
+ * because values will be passed to qemu functions taking int64_t. */
+ if ((INT64_MAX - entries * entry_len < offset) ||
+ (offset_into_cluster(s, offset) != 0)) {
+ error_setg(errp, "%s offset invalid", table_name);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static const char *const mutable_opts[] = {
+ QCOW2_OPT_LAZY_REFCOUNTS,
+ QCOW2_OPT_DISCARD_REQUEST,
+ QCOW2_OPT_DISCARD_SNAPSHOT,
+ QCOW2_OPT_DISCARD_OTHER,
+ QCOW2_OPT_OVERLAP,
+ QCOW2_OPT_OVERLAP_TEMPLATE,
+ QCOW2_OPT_OVERLAP_MAIN_HEADER,
+ QCOW2_OPT_OVERLAP_ACTIVE_L1,
+ QCOW2_OPT_OVERLAP_ACTIVE_L2,
+ QCOW2_OPT_OVERLAP_REFCOUNT_TABLE,
+ QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK,
+ QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE,
+ QCOW2_OPT_OVERLAP_INACTIVE_L1,
+ QCOW2_OPT_OVERLAP_INACTIVE_L2,
+ QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY,
+ QCOW2_OPT_CACHE_SIZE,
+ QCOW2_OPT_L2_CACHE_SIZE,
+ QCOW2_OPT_L2_CACHE_ENTRY_SIZE,
+ QCOW2_OPT_REFCOUNT_CACHE_SIZE,
+ QCOW2_OPT_CACHE_CLEAN_INTERVAL,
+ NULL
+};
+
+static QemuOptsList qcow2_runtime_opts = {
+ .name = "qcow2",
+ .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head),
+ .desc = {
+ {
+ .name = QCOW2_OPT_LAZY_REFCOUNTS,
+ .type = QEMU_OPT_BOOL,
+ .help = "Postpone refcount updates",
+ },
+ {
+ .name = QCOW2_OPT_DISCARD_REQUEST,
+ .type = QEMU_OPT_BOOL,
+ .help = "Pass guest discard requests to the layer below",
+ },
+ {
+ .name = QCOW2_OPT_DISCARD_SNAPSHOT,
+ .type = QEMU_OPT_BOOL,
+ .help = "Generate discard requests when snapshot related space "
+ "is freed",
+ },
+ {
+ .name = QCOW2_OPT_DISCARD_OTHER,
+ .type = QEMU_OPT_BOOL,
+ .help = "Generate discard requests when other clusters are freed",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP,
+ .type = QEMU_OPT_STRING,
+ .help = "Selects which overlap checks to perform from a range of "
+ "templates (none, constant, cached, all)",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_TEMPLATE,
+ .type = QEMU_OPT_STRING,
+ .help = "Selects which overlap checks to perform from a range of "
+ "templates (none, constant, cached, all)",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_MAIN_HEADER,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into the main qcow2 header",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_ACTIVE_L1,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into the active L1 table",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_ACTIVE_L2,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into an active L2 table",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into the refcount table",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into a refcount block",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into the snapshot table",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_INACTIVE_L1,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into an inactive L1 table",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_INACTIVE_L2,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into an inactive L2 table",
+ },
+ {
+ .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY,
+ .type = QEMU_OPT_BOOL,
+ .help = "Check for unintended writes into the bitmap directory",
+ },
+ {
+ .name = QCOW2_OPT_CACHE_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Maximum combined metadata (L2 tables and refcount blocks) "
+ "cache size",
+ },
+ {
+ .name = QCOW2_OPT_L2_CACHE_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Maximum L2 table cache size",
+ },
+ {
+ .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Size of each entry in the L2 cache",
+ },
+ {
+ .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Maximum refcount block cache size",
+ },
+ {
+ .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL,
+ .type = QEMU_OPT_NUMBER,
+ .help = "Clean unused cache entries after this time (in seconds)",
+ },
+ BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.",
+ "ID of secret providing qcow2 AES key or LUKS passphrase"),
+ { /* end of list */ }
+ },
+};
+
+static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = {
+ [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER,
+ [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1,
+ [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2,
+ [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE,
+ [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK,
+ [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE,
+ [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1,
+ [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2,
+ [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY,
+};
+
+static void cache_clean_timer_cb(void *opaque)
+{
+ BlockDriverState *bs = opaque;
+ BDRVQcow2State *s = bs->opaque;
+ qcow2_cache_clean_unused(s->l2_table_cache);
+ qcow2_cache_clean_unused(s->refcount_block_cache);
+ timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+ (int64_t) s->cache_clean_interval * 1000);
+}
+
+static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context)
+{
+ BDRVQcow2State *s = bs->opaque;
+ if (s->cache_clean_interval > 0) {
+ s->cache_clean_timer =
+ aio_timer_new_with_attrs(context, QEMU_CLOCK_VIRTUAL,
+ SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL,
+ cache_clean_timer_cb, bs);
+ timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
+ (int64_t) s->cache_clean_interval * 1000);
+ }
+}
+
+static void cache_clean_timer_del(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ if (s->cache_clean_timer) {
+ timer_free(s->cache_clean_timer);
+ s->cache_clean_timer = NULL;
+ }
+}
+
+static void qcow2_detach_aio_context(BlockDriverState *bs)
+{
+ cache_clean_timer_del(bs);
+}
+
+static void qcow2_attach_aio_context(BlockDriverState *bs,
+ AioContext *new_context)
+{
+ cache_clean_timer_init(bs, new_context);
+}
+
+static bool read_cache_sizes(BlockDriverState *bs, QemuOpts *opts,
+ uint64_t *l2_cache_size,
+ uint64_t *l2_cache_entry_size,
+ uint64_t *refcount_cache_size, Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint64_t combined_cache_size, l2_cache_max_setting;
+ bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set;
+ bool l2_cache_entry_size_set;
+ int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size;
+ uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE;
+ uint64_t max_l2_entries = DIV_ROUND_UP(virtual_disk_size, s->cluster_size);
+ /* An L2 table is always one cluster in size so the max cache size
+ * should be a multiple of the cluster size. */
+ uint64_t max_l2_cache = ROUND_UP(max_l2_entries * l2_entry_size(s),
+ s->cluster_size);
+
+ combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE);
+ l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE);
+ refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
+ l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE);
+
+ combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0);
+ l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE,
+ DEFAULT_L2_CACHE_MAX_SIZE);
+ *refcount_cache_size = qemu_opt_get_size(opts,
+ QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0);
+
+ *l2_cache_entry_size = qemu_opt_get_size(
+ opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size);
+
+ *l2_cache_size = MIN(max_l2_cache, l2_cache_max_setting);
+
+ if (combined_cache_size_set) {
+ if (l2_cache_size_set && refcount_cache_size_set) {
+ error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE
+ " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set "
+ "at the same time");
+ return false;
+ } else if (l2_cache_size_set &&
+ (l2_cache_max_setting > combined_cache_size)) {
+ error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed "
+ QCOW2_OPT_CACHE_SIZE);
+ return false;
+ } else if (*refcount_cache_size > combined_cache_size) {
+ error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed "
+ QCOW2_OPT_CACHE_SIZE);
+ return false;
+ }
+
+ if (l2_cache_size_set) {
+ *refcount_cache_size = combined_cache_size - *l2_cache_size;
+ } else if (refcount_cache_size_set) {
+ *l2_cache_size = combined_cache_size - *refcount_cache_size;
+ } else {
+ /* Assign as much memory as possible to the L2 cache, and
+ * use the remainder for the refcount cache */
+ if (combined_cache_size >= max_l2_cache + min_refcount_cache) {
+ *l2_cache_size = max_l2_cache;
+ *refcount_cache_size = combined_cache_size - *l2_cache_size;
+ } else {
+ *refcount_cache_size =
+ MIN(combined_cache_size, min_refcount_cache);
+ *l2_cache_size = combined_cache_size - *refcount_cache_size;
+ }
+ }
+ }
+
+ /*
+ * If the L2 cache is not enough to cover the whole disk then
+ * default to 4KB entries. Smaller entries reduce the cost of
+ * loads and evictions and increase I/O performance.
+ */
+ if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) {
+ *l2_cache_entry_size = MIN(s->cluster_size, 4096);
+ }
+
+ /* l2_cache_size and refcount_cache_size are ensured to have at least
+ * their minimum values in qcow2_update_options_prepare() */
+
+ if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) ||
+ *l2_cache_entry_size > s->cluster_size ||
+ !is_power_of_2(*l2_cache_entry_size)) {
+ error_setg(errp, "L2 cache entry size must be a power of two "
+ "between %d and the cluster size (%d)",
+ 1 << MIN_CLUSTER_BITS, s->cluster_size);
+ return false;
+ }
+
+ return true;
+}
+
+typedef struct Qcow2ReopenState {
+ Qcow2Cache *l2_table_cache;
+ Qcow2Cache *refcount_block_cache;
+ int l2_slice_size; /* Number of entries in a slice of the L2 table */
+ bool use_lazy_refcounts;
+ int overlap_check;
+ bool discard_passthrough[QCOW2_DISCARD_MAX];
+ uint64_t cache_clean_interval;
+ QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */
+} Qcow2ReopenState;
+
+static int qcow2_update_options_prepare(BlockDriverState *bs,
+ Qcow2ReopenState *r,
+ QDict *options, int flags,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ QemuOpts *opts = NULL;
+ const char *opt_overlap_check, *opt_overlap_check_template;
+ int overlap_check_template = 0;
+ uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size;
+ int i;
+ const char *encryptfmt;
+ QDict *encryptopts = NULL;
+ int ret;
+
+ qdict_extract_subqdict(options, &encryptopts, "encrypt.");
+ encryptfmt = qdict_get_try_str(encryptopts, "format");
+
+ opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort);
+ if (!qemu_opts_absorb_qdict(opts, options, errp)) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* get L2 table/refcount block cache size from command line options */
+ if (!read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size,
+ &refcount_cache_size, errp)) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ l2_cache_size /= l2_cache_entry_size;
+ if (l2_cache_size < MIN_L2_CACHE_SIZE) {
+ l2_cache_size = MIN_L2_CACHE_SIZE;
+ }
+ if (l2_cache_size > INT_MAX) {
+ error_setg(errp, "L2 cache size too big");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ refcount_cache_size /= s->cluster_size;
+ if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) {
+ refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE;
+ }
+ if (refcount_cache_size > INT_MAX) {
+ error_setg(errp, "Refcount cache size too big");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* alloc new L2 table/refcount block cache, flush old one */
+ if (s->l2_table_cache) {
+ ret = qcow2_cache_flush(bs, s->l2_table_cache);
+ if (ret) {
+ error_setg_errno(errp, -ret, "Failed to flush the L2 table cache");
+ goto fail;
+ }
+ }
+
+ if (s->refcount_block_cache) {
+ ret = qcow2_cache_flush(bs, s->refcount_block_cache);
+ if (ret) {
+ error_setg_errno(errp, -ret,
+ "Failed to flush the refcount block cache");
+ goto fail;
+ }
+ }
+
+ r->l2_slice_size = l2_cache_entry_size / l2_entry_size(s);
+ r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size,
+ l2_cache_entry_size);
+ r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size,
+ s->cluster_size);
+ if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) {
+ error_setg(errp, "Could not allocate metadata caches");
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ /* New interval for cache cleanup timer */
+ r->cache_clean_interval =
+ qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL,
+ DEFAULT_CACHE_CLEAN_INTERVAL);
+#ifndef CONFIG_LINUX
+ if (r->cache_clean_interval != 0) {
+ error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL
+ " not supported on this host");
+ ret = -EINVAL;
+ goto fail;
+ }
+#endif
+ if (r->cache_clean_interval > UINT_MAX) {
+ error_setg(errp, "Cache clean interval too big");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* lazy-refcounts; flush if going from enabled to disabled */
+ r->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,
+ (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS));
+ if (r->use_lazy_refcounts && s->qcow_version < 3) {
+ error_setg(errp, "Lazy refcounts require a qcow2 image with at least "
+ "qemu 1.1 compatibility level");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ if (s->use_lazy_refcounts && !r->use_lazy_refcounts) {
+ ret = qcow2_mark_clean(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to disable lazy refcounts");
+ goto fail;
+ }
+ }
+
+ /* Overlap check options */
+ opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP);
+ opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE);
+ if (opt_overlap_check_template && opt_overlap_check &&
+ strcmp(opt_overlap_check_template, opt_overlap_check))
+ {
+ error_setg(errp, "Conflicting values for qcow2 options '"
+ QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE
+ "' ('%s')", opt_overlap_check, opt_overlap_check_template);
+ ret = -EINVAL;
+ goto fail;
+ }
+ if (!opt_overlap_check) {
+ opt_overlap_check = opt_overlap_check_template ?: "cached";
+ }
+
+ if (!strcmp(opt_overlap_check, "none")) {
+ overlap_check_template = 0;
+ } else if (!strcmp(opt_overlap_check, "constant")) {
+ overlap_check_template = QCOW2_OL_CONSTANT;
+ } else if (!strcmp(opt_overlap_check, "cached")) {
+ overlap_check_template = QCOW2_OL_CACHED;
+ } else if (!strcmp(opt_overlap_check, "all")) {
+ overlap_check_template = QCOW2_OL_ALL;
+ } else {
+ error_setg(errp, "Unsupported value '%s' for qcow2 option "
+ "'overlap-check'. Allowed are any of the following: "
+ "none, constant, cached, all", opt_overlap_check);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ r->overlap_check = 0;
+ for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) {
+ /* overlap-check defines a template bitmask, but every flag may be
+ * overwritten through the associated boolean option */
+ r->overlap_check |=
+ qemu_opt_get_bool(opts, overlap_bool_option_names[i],
+ overlap_check_template & (1 << i)) << i;
+ }
+
+ r->discard_passthrough[QCOW2_DISCARD_NEVER] = false;
+ r->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true;
+ r->discard_passthrough[QCOW2_DISCARD_REQUEST] =
+ qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST,
+ flags & BDRV_O_UNMAP);
+ r->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] =
+ qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true);
+ r->discard_passthrough[QCOW2_DISCARD_OTHER] =
+ qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false);
+
+ switch (s->crypt_method_header) {
+ case QCOW_CRYPT_NONE:
+ if (encryptfmt) {
+ error_setg(errp, "No encryption in image header, but options "
+ "specified format '%s'", encryptfmt);
+ ret = -EINVAL;
+ goto fail;
+ }
+ break;
+
+ case QCOW_CRYPT_AES:
+ if (encryptfmt && !g_str_equal(encryptfmt, "aes")) {
+ error_setg(errp,
+ "Header reported 'aes' encryption format but "
+ "options specify '%s'", encryptfmt);
+ ret = -EINVAL;
+ goto fail;
+ }
+ qdict_put_str(encryptopts, "format", "qcow");
+ r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp);
+ if (!r->crypto_opts) {
+ ret = -EINVAL;
+ goto fail;
+ }
+ break;
+
+ case QCOW_CRYPT_LUKS:
+ if (encryptfmt && !g_str_equal(encryptfmt, "luks")) {
+ error_setg(errp,
+ "Header reported 'luks' encryption format but "
+ "options specify '%s'", encryptfmt);
+ ret = -EINVAL;
+ goto fail;
+ }
+ qdict_put_str(encryptopts, "format", "luks");
+ r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp);
+ if (!r->crypto_opts) {
+ ret = -EINVAL;
+ goto fail;
+ }
+ break;
+
+ default:
+ error_setg(errp, "Unsupported encryption method %d",
+ s->crypt_method_header);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ ret = 0;
+fail:
+ qobject_unref(encryptopts);
+ qemu_opts_del(opts);
+ opts = NULL;
+ return ret;
+}
+
+static void qcow2_update_options_commit(BlockDriverState *bs,
+ Qcow2ReopenState *r)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int i;
+
+ if (s->l2_table_cache) {
+ qcow2_cache_destroy(s->l2_table_cache);
+ }
+ if (s->refcount_block_cache) {
+ qcow2_cache_destroy(s->refcount_block_cache);
+ }
+ s->l2_table_cache = r->l2_table_cache;
+ s->refcount_block_cache = r->refcount_block_cache;
+ s->l2_slice_size = r->l2_slice_size;
+
+ s->overlap_check = r->overlap_check;
+ s->use_lazy_refcounts = r->use_lazy_refcounts;
+
+ for (i = 0; i < QCOW2_DISCARD_MAX; i++) {
+ s->discard_passthrough[i] = r->discard_passthrough[i];
+ }
+
+ if (s->cache_clean_interval != r->cache_clean_interval) {
+ cache_clean_timer_del(bs);
+ s->cache_clean_interval = r->cache_clean_interval;
+ cache_clean_timer_init(bs, bdrv_get_aio_context(bs));
+ }
+
+ qapi_free_QCryptoBlockOpenOptions(s->crypto_opts);
+ s->crypto_opts = r->crypto_opts;
+}
+
+static void qcow2_update_options_abort(BlockDriverState *bs,
+ Qcow2ReopenState *r)
+{
+ if (r->l2_table_cache) {
+ qcow2_cache_destroy(r->l2_table_cache);
+ }
+ if (r->refcount_block_cache) {
+ qcow2_cache_destroy(r->refcount_block_cache);
+ }
+ qapi_free_QCryptoBlockOpenOptions(r->crypto_opts);
+}
+
+static int qcow2_update_options(BlockDriverState *bs, QDict *options,
+ int flags, Error **errp)
+{
+ Qcow2ReopenState r = {};
+ int ret;
+
+ ret = qcow2_update_options_prepare(bs, &r, options, flags, errp);
+ if (ret >= 0) {
+ qcow2_update_options_commit(bs, &r);
+ } else {
+ qcow2_update_options_abort(bs, &r);
+ }
+
+ return ret;
+}
+
+static int validate_compression_type(BDRVQcow2State *s, Error **errp)
+{
+ switch (s->compression_type) {
+ case QCOW2_COMPRESSION_TYPE_ZLIB:
+#ifdef CONFIG_ZSTD
+ case QCOW2_COMPRESSION_TYPE_ZSTD:
+#endif
+ break;
+
+ default:
+ error_setg(errp, "qcow2: unknown compression type: %u",
+ s->compression_type);
+ return -ENOTSUP;
+ }
+
+ /*
+ * if the compression type differs from QCOW2_COMPRESSION_TYPE_ZLIB
+ * the incompatible feature flag must be set
+ */
+ if (s->compression_type == QCOW2_COMPRESSION_TYPE_ZLIB) {
+ if (s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION) {
+ error_setg(errp, "qcow2: Compression type incompatible feature "
+ "bit must not be set");
+ return -EINVAL;
+ }
+ } else {
+ if (!(s->incompatible_features & QCOW2_INCOMPAT_COMPRESSION)) {
+ error_setg(errp, "qcow2: Compression type incompatible feature "
+ "bit must be set");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/* Called with s->lock held. */
+static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
+ int flags, Error **errp)
+{
+ ERRP_GUARD();
+ BDRVQcow2State *s = bs->opaque;
+ unsigned int len, i;
+ int ret = 0;
+ QCowHeader header;
+ uint64_t ext_end;
+ uint64_t l1_vm_state_index;
+ bool update_header = false;
+
+ ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read qcow2 header");
+ goto fail;
+ }
+ header.magic = be32_to_cpu(header.magic);
+ header.version = be32_to_cpu(header.version);
+ header.backing_file_offset = be64_to_cpu(header.backing_file_offset);
+ header.backing_file_size = be32_to_cpu(header.backing_file_size);
+ header.size = be64_to_cpu(header.size);
+ header.cluster_bits = be32_to_cpu(header.cluster_bits);
+ header.crypt_method = be32_to_cpu(header.crypt_method);
+ header.l1_table_offset = be64_to_cpu(header.l1_table_offset);
+ header.l1_size = be32_to_cpu(header.l1_size);
+ header.refcount_table_offset = be64_to_cpu(header.refcount_table_offset);
+ header.refcount_table_clusters =
+ be32_to_cpu(header.refcount_table_clusters);
+ header.snapshots_offset = be64_to_cpu(header.snapshots_offset);
+ header.nb_snapshots = be32_to_cpu(header.nb_snapshots);
+
+ if (header.magic != QCOW_MAGIC) {
+ error_setg(errp, "Image is not in qcow2 format");
+ ret = -EINVAL;
+ goto fail;
+ }
+ if (header.version < 2 || header.version > 3) {
+ error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version);
+ ret = -ENOTSUP;
+ goto fail;
+ }
+
+ s->qcow_version = header.version;
+
+ /* Initialise cluster size */
+ if (header.cluster_bits < MIN_CLUSTER_BITS ||
+ header.cluster_bits > MAX_CLUSTER_BITS) {
+ error_setg(errp, "Unsupported cluster size: 2^%" PRIu32,
+ header.cluster_bits);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ s->cluster_bits = header.cluster_bits;
+ s->cluster_size = 1 << s->cluster_bits;
+
+ /* Initialise version 3 header fields */
+ if (header.version == 2) {
+ header.incompatible_features = 0;
+ header.compatible_features = 0;
+ header.autoclear_features = 0;
+ header.refcount_order = 4;
+ header.header_length = 72;
+ } else {
+ header.incompatible_features =
+ be64_to_cpu(header.incompatible_features);
+ header.compatible_features = be64_to_cpu(header.compatible_features);
+ header.autoclear_features = be64_to_cpu(header.autoclear_features);
+ header.refcount_order = be32_to_cpu(header.refcount_order);
+ header.header_length = be32_to_cpu(header.header_length);
+
+ if (header.header_length < 104) {
+ error_setg(errp, "qcow2 header too short");
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ if (header.header_length > s->cluster_size) {
+ error_setg(errp, "qcow2 header exceeds cluster size");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ if (header.header_length > sizeof(header)) {
+ s->unknown_header_fields_size = header.header_length - sizeof(header);
+ s->unknown_header_fields = g_malloc(s->unknown_header_fields_size);
+ ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields,
+ s->unknown_header_fields_size);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read unknown qcow2 header "
+ "fields");
+ goto fail;
+ }
+ }
+
+ if (header.backing_file_offset > s->cluster_size) {
+ error_setg(errp, "Invalid backing file offset");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ if (header.backing_file_offset) {
+ ext_end = header.backing_file_offset;
+ } else {
+ ext_end = 1 << header.cluster_bits;
+ }
+
+ /* Handle feature bits */
+ s->incompatible_features = header.incompatible_features;
+ s->compatible_features = header.compatible_features;
+ s->autoclear_features = header.autoclear_features;
+
+ /*
+ * Handle compression type
+ * Older qcow2 images don't contain the compression type header.
+ * Distinguish them by the header length and use
+ * the only valid (default) compression type in that case
+ */
+ if (header.header_length > offsetof(QCowHeader, compression_type)) {
+ s->compression_type = header.compression_type;
+ } else {
+ s->compression_type = QCOW2_COMPRESSION_TYPE_ZLIB;
+ }
+
+ ret = validate_compression_type(s, errp);
+ if (ret) {
+ goto fail;
+ }
+
+ if (s->incompatible_features & ~QCOW2_INCOMPAT_MASK) {
+ void *feature_table = NULL;
+ qcow2_read_extensions(bs, header.header_length, ext_end,
+ &feature_table, flags, NULL, NULL);
+ report_unsupported_feature(errp, feature_table,
+ s->incompatible_features &
+ ~QCOW2_INCOMPAT_MASK);
+ ret = -ENOTSUP;
+ g_free(feature_table);
+ goto fail;
+ }
+
+ if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) {
+ /* Corrupt images may not be written to unless they are being repaired
+ */
+ if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_CHECK)) {
+ error_setg(errp, "qcow2: Image is corrupt; cannot be opened "
+ "read/write");
+ ret = -EACCES;
+ goto fail;
+ }
+ }
+
+ s->subclusters_per_cluster =
+ has_subclusters(s) ? QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER : 1;
+ s->subcluster_size = s->cluster_size / s->subclusters_per_cluster;
+ s->subcluster_bits = ctz32(s->subcluster_size);
+
+ if (s->subcluster_size < (1 << MIN_CLUSTER_BITS)) {
+ error_setg(errp, "Unsupported subcluster size: %d", s->subcluster_size);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* Check support for various header values */
+ if (header.refcount_order > 6) {
+ error_setg(errp, "Reference count entry width too large; may not "
+ "exceed 64 bits");
+ ret = -EINVAL;
+ goto fail;
+ }
+ s->refcount_order = header.refcount_order;
+ s->refcount_bits = 1 << s->refcount_order;
+ s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1);
+ s->refcount_max += s->refcount_max - 1;
+
+ s->crypt_method_header = header.crypt_method;
+ if (s->crypt_method_header) {
+ if (bdrv_uses_whitelist() &&
+ s->crypt_method_header == QCOW_CRYPT_AES) {
+ error_setg(errp,
+ "Use of AES-CBC encrypted qcow2 images is no longer "
+ "supported in system emulators");
+ error_append_hint(errp,
+ "You can use 'qemu-img convert' to convert your "
+ "image to an alternative supported format, such "
+ "as unencrypted qcow2, or raw with the LUKS "
+ "format instead.\n");
+ ret = -ENOSYS;
+ goto fail;
+ }
+
+ if (s->crypt_method_header == QCOW_CRYPT_AES) {
+ s->crypt_physical_offset = false;
+ } else {
+ /* Assuming LUKS and any future crypt methods we
+ * add will all use physical offsets, due to the
+ * fact that the alternative is insecure... */
+ s->crypt_physical_offset = true;
+ }
+
+ bs->encrypted = true;
+ }
+
+ s->l2_bits = s->cluster_bits - ctz32(l2_entry_size(s));
+ s->l2_size = 1 << s->l2_bits;
+ /* 2^(s->refcount_order - 3) is the refcount width in bytes */
+ s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3);
+ s->refcount_block_size = 1 << s->refcount_block_bits;
+ bs->total_sectors = header.size / BDRV_SECTOR_SIZE;
+ s->csize_shift = (62 - (s->cluster_bits - 8));
+ s->csize_mask = (1 << (s->cluster_bits - 8)) - 1;
+ s->cluster_offset_mask = (1LL << s->csize_shift) - 1;
+
+ s->refcount_table_offset = header.refcount_table_offset;
+ s->refcount_table_size =
+ header.refcount_table_clusters << (s->cluster_bits - 3);
+
+ if (header.refcount_table_clusters == 0 && !(flags & BDRV_O_CHECK)) {
+ error_setg(errp, "Image does not contain a reference count table");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ ret = qcow2_validate_table(bs, s->refcount_table_offset,
+ header.refcount_table_clusters,
+ s->cluster_size, QCOW_MAX_REFTABLE_SIZE,
+ "Reference count table", errp);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ if (!(flags & BDRV_O_CHECK)) {
+ /*
+ * The total size in bytes of the snapshot table is checked in
+ * qcow2_read_snapshots() because the size of each snapshot is
+ * variable and we don't know it yet.
+ * Here we only check the offset and number of snapshots.
+ */
+ ret = qcow2_validate_table(bs, header.snapshots_offset,
+ header.nb_snapshots,
+ sizeof(QCowSnapshotHeader),
+ sizeof(QCowSnapshotHeader) *
+ QCOW_MAX_SNAPSHOTS,
+ "Snapshot table", errp);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+
+ /* read the level 1 table */
+ ret = qcow2_validate_table(bs, header.l1_table_offset,
+ header.l1_size, L1E_SIZE,
+ QCOW_MAX_L1_SIZE, "Active L1 table", errp);
+ if (ret < 0) {
+ goto fail;
+ }
+ s->l1_size = header.l1_size;
+ s->l1_table_offset = header.l1_table_offset;
+
+ l1_vm_state_index = size_to_l1(s, header.size);
+ if (l1_vm_state_index > INT_MAX) {
+ error_setg(errp, "Image is too big");
+ ret = -EFBIG;
+ goto fail;
+ }
+ s->l1_vm_state_index = l1_vm_state_index;
+
+ /* the L1 table must contain at least enough entries to put
+ header.size bytes */
+ if (s->l1_size < s->l1_vm_state_index) {
+ error_setg(errp, "L1 table is too small");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ if (s->l1_size > 0) {
+ s->l1_table = qemu_try_blockalign(bs->file->bs, s->l1_size * L1E_SIZE);
+ if (s->l1_table == NULL) {
+ error_setg(errp, "Could not allocate L1 table");
+ ret = -ENOMEM;
+ goto fail;
+ }
+ ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
+ s->l1_size * L1E_SIZE);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read L1 table");
+ goto fail;
+ }
+ for(i = 0;i < s->l1_size; i++) {
+ s->l1_table[i] = be64_to_cpu(s->l1_table[i]);
+ }
+ }
+
+ /* Parse driver-specific options */
+ ret = qcow2_update_options(bs, options, flags, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ s->flags = flags;
+
+ ret = qcow2_refcount_init(bs);
+ if (ret != 0) {
+ error_setg_errno(errp, -ret, "Could not initialize refcount handling");
+ goto fail;
+ }
+
+ QLIST_INIT(&s->cluster_allocs);
+ QTAILQ_INIT(&s->discards);
+
+ /* read qcow2 extensions */
+ if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL,
+ flags, &update_header, errp)) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* Open external data file */
+ s->data_file = bdrv_open_child(NULL, options, "data-file", bs,
+ &child_of_bds, BDRV_CHILD_DATA,
+ true, errp);
+ if (*errp) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) {
+ if (!s->data_file && s->image_data_file) {
+ s->data_file = bdrv_open_child(s->image_data_file, options,
+ "data-file", bs, &child_of_bds,
+ BDRV_CHILD_DATA, false, errp);
+ if (!s->data_file) {
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+ if (!s->data_file) {
+ error_setg(errp, "'data-file' is required for this image");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* No data here */
+ bs->file->role &= ~BDRV_CHILD_DATA;
+
+ /* Must succeed because we have given up permissions if anything */
+ bdrv_child_refresh_perms(bs, bs->file, &error_abort);
+ } else {
+ if (s->data_file) {
+ error_setg(errp, "'data-file' can only be set for images with an "
+ "external data file");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ s->data_file = bs->file;
+
+ if (data_file_is_raw(bs)) {
+ error_setg(errp, "data-file-raw requires a data file");
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ /* qcow2_read_extension may have set up the crypto context
+ * if the crypt method needs a header region, some methods
+ * don't need header extensions, so must check here
+ */
+ if (s->crypt_method_header && !s->crypto) {
+ if (s->crypt_method_header == QCOW_CRYPT_AES) {
+ unsigned int cflags = 0;
+ if (flags & BDRV_O_NO_IO) {
+ cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
+ }
+ s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.",
+ NULL, NULL, cflags,
+ QCOW2_MAX_THREADS, errp);
+ if (!s->crypto) {
+ ret = -EINVAL;
+ goto fail;
+ }
+ } else if (!(flags & BDRV_O_NO_IO)) {
+ error_setg(errp, "Missing CRYPTO header for crypt method %d",
+ s->crypt_method_header);
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+
+ /* read the backing file name */
+ if (header.backing_file_offset != 0) {
+ len = header.backing_file_size;
+ if (len > MIN(1023, s->cluster_size - header.backing_file_offset) ||
+ len >= sizeof(bs->backing_file)) {
+ error_setg(errp, "Backing file name too long");
+ ret = -EINVAL;
+ goto fail;
+ }
+ ret = bdrv_pread(bs->file, header.backing_file_offset,
+ bs->auto_backing_file, len);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not read backing file name");
+ goto fail;
+ }
+ bs->auto_backing_file[len] = '\0';
+ pstrcpy(bs->backing_file, sizeof(bs->backing_file),
+ bs->auto_backing_file);
+ s->image_backing_file = g_strdup(bs->auto_backing_file);
+ }
+
+ /*
+ * Internal snapshots; skip reading them in check mode, because
+ * we do not need them then, and we do not want to abort because
+ * of a broken table.
+ */
+ if (!(flags & BDRV_O_CHECK)) {
+ s->snapshots_offset = header.snapshots_offset;
+ s->nb_snapshots = header.nb_snapshots;
+
+ ret = qcow2_read_snapshots(bs, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+
+ /* Clear unknown autoclear feature bits */
+ update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK;
+ update_header = update_header && bdrv_is_writable(bs);
+ if (update_header) {
+ s->autoclear_features &= QCOW2_AUTOCLEAR_MASK;
+ }
+
+ /* == Handle persistent dirty bitmaps ==
+ *
+ * We want load dirty bitmaps in three cases:
+ *
+ * 1. Normal open of the disk in active mode, not related to invalidation
+ * after migration.
+ *
+ * 2. Invalidation of the target vm after pre-copy phase of migration, if
+ * bitmaps are _not_ migrating through migration channel, i.e.
+ * 'dirty-bitmaps' capability is disabled.
+ *
+ * 3. Invalidation of source vm after failed or canceled migration.
+ * This is a very interesting case. There are two possible types of
+ * bitmaps:
+ *
+ * A. Stored on inactivation and removed. They should be loaded from the
+ * image.
+ *
+ * B. Not stored: not-persistent bitmaps and bitmaps, migrated through
+ * the migration channel (with dirty-bitmaps capability).
+ *
+ * On the other hand, there are two possible sub-cases:
+ *
+ * 3.1 disk was changed by somebody else while were inactive. In this
+ * case all in-RAM dirty bitmaps (both persistent and not) are
+ * definitely invalid. And we don't have any method to determine
+ * this.
+ *
+ * Simple and safe thing is to just drop all the bitmaps of type B on
+ * inactivation. But in this case we lose bitmaps in valid 4.2 case.
+ *
+ * On the other hand, resuming source vm, if disk was already changed
+ * is a bad thing anyway: not only bitmaps, the whole vm state is
+ * out of sync with disk.
+ *
+ * This means, that user or management tool, who for some reason
+ * decided to resume source vm, after disk was already changed by
+ * target vm, should at least drop all dirty bitmaps by hand.
+ *
+ * So, we can ignore this case for now, but TODO: "generation"
+ * extension for qcow2, to determine, that image was changed after
+ * last inactivation. And if it is changed, we will drop (or at least
+ * mark as 'invalid' all the bitmaps of type B, both persistent
+ * and not).
+ *
+ * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved
+ * to disk ('dirty-bitmaps' capability disabled), or not saved
+ * ('dirty-bitmaps' capability enabled), but we don't need to care
+ * of: let's load bitmaps as always: stored bitmaps will be loaded,
+ * and not stored has flag IN_USE=1 in the image and will be skipped
+ * on loading.
+ *
+ * One remaining possible case when we don't want load bitmaps:
+ *
+ * 4. Open disk in inactive mode in target vm (bitmaps are migrating or
+ * will be loaded on invalidation, no needs try loading them before)
+ */
+
+ if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) {
+ /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */
+ bool header_updated;
+ if (!qcow2_load_dirty_bitmaps(bs, &header_updated, errp)) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ update_header = update_header && !header_updated;
+ }
+
+ if (update_header) {
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not update qcow2 header");
+ goto fail;
+ }
+ }
+
+ bs->supported_zero_flags = header.version >= 3 ?
+ BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0;
+ bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
+
+ /* Repair image if dirty */
+ if (!(flags & BDRV_O_CHECK) && bdrv_is_writable(bs) &&
+ (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) {
+ BdrvCheckResult result = {0};
+
+ ret = qcow2_co_check_locked(bs, &result,
+ BDRV_FIX_ERRORS | BDRV_FIX_LEAKS);
+ if (ret < 0 || result.check_errors) {
+ if (ret >= 0) {
+ ret = -EIO;
+ }
+ error_setg_errno(errp, -ret, "Could not repair dirty image");
+ goto fail;
+ }
+ }
+
+#ifdef DEBUG_ALLOC
+ {
+ BdrvCheckResult result = {0};
+ qcow2_check_refcounts(bs, &result, 0);
+ }
+#endif
+
+ qemu_co_queue_init(&s->thread_task_queue);
+
+ return ret;
+
+ fail:
+ g_free(s->image_data_file);
+ if (has_data_file(bs)) {
+ bdrv_unref_child(bs, s->data_file);
+ s->data_file = NULL;
+ }
+ g_free(s->unknown_header_fields);
+ cleanup_unknown_header_ext(bs);
+ qcow2_free_snapshots(bs);
+ qcow2_refcount_close(bs);
+ qemu_vfree(s->l1_table);
+ /* else pre-write overlap checks in cache_destroy may crash */
+ s->l1_table = NULL;
+ cache_clean_timer_del(bs);
+ if (s->l2_table_cache) {
+ qcow2_cache_destroy(s->l2_table_cache);
+ }
+ if (s->refcount_block_cache) {
+ qcow2_cache_destroy(s->refcount_block_cache);
+ }
+ qcrypto_block_free(s->crypto);
+ qapi_free_QCryptoBlockOpenOptions(s->crypto_opts);
+ return ret;
+}
+
+typedef struct QCow2OpenCo {
+ BlockDriverState *bs;
+ QDict *options;
+ int flags;
+ Error **errp;
+ int ret;
+} QCow2OpenCo;
+
+static void coroutine_fn qcow2_open_entry(void *opaque)
+{
+ QCow2OpenCo *qoc = opaque;
+ BDRVQcow2State *s = qoc->bs->opaque;
+
+ qemu_co_mutex_lock(&s->lock);
+ qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp);
+ qemu_co_mutex_unlock(&s->lock);
+}
+
+static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ QCow2OpenCo qoc = {
+ .bs = bs,
+ .options = options,
+ .flags = flags,
+ .errp = errp,
+ .ret = -EINPROGRESS
+ };
+
+ bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
+ BDRV_CHILD_IMAGE, false, errp);
+ if (!bs->file) {
+ return -EINVAL;
+ }
+
+ /* Initialise locks */
+ qemu_co_mutex_init(&s->lock);
+
+ if (qemu_in_coroutine()) {
+ /* From bdrv_co_create. */
+ qcow2_open_entry(&qoc);
+ } else {
+ assert(qemu_get_current_aio_context() == qemu_get_aio_context());
+ qemu_coroutine_enter(qemu_coroutine_create(qcow2_open_entry, &qoc));
+ BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS);
+ }
+ return qoc.ret;
+}
+
+static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+
+ if (bs->encrypted) {
+ /* Encryption works on a sector granularity */
+ bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto);
+ }
+ bs->bl.pwrite_zeroes_alignment = s->subcluster_size;
+ bs->bl.pdiscard_alignment = s->cluster_size;
+}
+
+static int qcow2_reopen_prepare(BDRVReopenState *state,
+ BlockReopenQueue *queue, Error **errp)
+{
+ BDRVQcow2State *s = state->bs->opaque;
+ Qcow2ReopenState *r;
+ int ret;
+
+ r = g_new0(Qcow2ReopenState, 1);
+ state->opaque = r;
+
+ ret = qcow2_update_options_prepare(state->bs, r, state->options,
+ state->flags, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ /* We need to write out any unwritten data if we reopen read-only. */
+ if ((state->flags & BDRV_O_RDWR) == 0) {
+ ret = qcow2_reopen_bitmaps_ro(state->bs, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = bdrv_flush(state->bs);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = qcow2_mark_clean(state->bs);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+
+ /*
+ * Without an external data file, s->data_file points to the same BdrvChild
+ * as bs->file. It needs to be resynced after reopen because bs->file may
+ * be changed. We can't use it in the meantime.
+ */
+ if (!has_data_file(state->bs)) {
+ assert(s->data_file == state->bs->file);
+ s->data_file = NULL;
+ }
+
+ return 0;
+
+fail:
+ qcow2_update_options_abort(state->bs, r);
+ g_free(r);
+ return ret;
+}
+
+static void qcow2_reopen_commit(BDRVReopenState *state)
+{
+ BDRVQcow2State *s = state->bs->opaque;
+
+ qcow2_update_options_commit(state->bs, state->opaque);
+ if (!s->data_file) {
+ /*
+ * If we don't have an external data file, s->data_file was cleared by
+ * qcow2_reopen_prepare() and needs to be updated.
+ */
+ s->data_file = state->bs->file;
+ }
+ g_free(state->opaque);
+}
+
+static void qcow2_reopen_commit_post(BDRVReopenState *state)
+{
+ if (state->flags & BDRV_O_RDWR) {
+ Error *local_err = NULL;
+
+ if (qcow2_reopen_bitmaps_rw(state->bs, &local_err) < 0) {
+ /*
+ * This is not fatal, bitmaps just left read-only, so all following
+ * writes will fail. User can remove read-only bitmaps to unblock
+ * writes or retry reopen.
+ */
+ error_reportf_err(local_err,
+ "%s: Failed to make dirty bitmaps writable: ",
+ bdrv_get_node_name(state->bs));
+ }
+ }
+}
+
+static void qcow2_reopen_abort(BDRVReopenState *state)
+{
+ BDRVQcow2State *s = state->bs->opaque;
+
+ if (!s->data_file) {
+ /*
+ * If we don't have an external data file, s->data_file was cleared by
+ * qcow2_reopen_prepare() and needs to be restored.
+ */
+ s->data_file = state->bs->file;
+ }
+ qcow2_update_options_abort(state->bs, state->opaque);
+ g_free(state->opaque);
+}
+
+static void qcow2_join_options(QDict *options, QDict *old_options)
+{
+ bool has_new_overlap_template =
+ qdict_haskey(options, QCOW2_OPT_OVERLAP) ||
+ qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE);
+ bool has_new_total_cache_size =
+ qdict_haskey(options, QCOW2_OPT_CACHE_SIZE);
+ bool has_all_cache_options;
+
+ /* New overlap template overrides all old overlap options */
+ if (has_new_overlap_template) {
+ qdict_del(old_options, QCOW2_OPT_OVERLAP);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1);
+ qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2);
+ }
+
+ /* New total cache size overrides all old options */
+ if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) {
+ qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE);
+ qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
+ }
+
+ qdict_join(options, old_options, false);
+
+ /*
+ * If after merging all cache size options are set, an old total size is
+ * overwritten. Do keep all options, however, if all three are new. The
+ * resulting error message is what we want to happen.
+ */
+ has_all_cache_options =
+ qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) ||
+ qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) ||
+ qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
+
+ if (has_all_cache_options && !has_new_total_cache_size) {
+ qdict_del(options, QCOW2_OPT_CACHE_SIZE);
+ }
+}
+
+static int coroutine_fn qcow2_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset, int64_t count,
+ int64_t *pnum, int64_t *map,
+ BlockDriverState **file)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint64_t host_offset;
+ unsigned int bytes;
+ QCow2SubclusterType type;
+ int ret, status = 0;
+
+ qemu_co_mutex_lock(&s->lock);
+
+ if (!s->metadata_preallocation_checked) {
+ ret = qcow2_detect_metadata_preallocation(bs);
+ s->metadata_preallocation = (ret == 1);
+ s->metadata_preallocation_checked = true;
+ }
+
+ bytes = MIN(INT_MAX, count);
+ ret = qcow2_get_host_offset(bs, offset, &bytes, &host_offset, &type);
+ qemu_co_mutex_unlock(&s->lock);
+ if (ret < 0) {
+ return ret;
+ }
+
+ *pnum = bytes;
+
+ if ((type == QCOW2_SUBCLUSTER_NORMAL ||
+ type == QCOW2_SUBCLUSTER_ZERO_ALLOC ||
+ type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) && !s->crypto) {
+ *map = host_offset;
+ *file = s->data_file->bs;
+ status |= BDRV_BLOCK_OFFSET_VALID;
+ }
+ if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN ||
+ type == QCOW2_SUBCLUSTER_ZERO_ALLOC) {
+ status |= BDRV_BLOCK_ZERO;
+ } else if (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN &&
+ type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC) {
+ status |= BDRV_BLOCK_DATA;
+ }
+ if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) &&
+ (status & BDRV_BLOCK_OFFSET_VALID))
+ {
+ status |= BDRV_BLOCK_RECURSE;
+ }
+ return status;
+}
+
+static coroutine_fn int qcow2_handle_l2meta(BlockDriverState *bs,
+ QCowL2Meta **pl2meta,
+ bool link_l2)
+{
+ int ret = 0;
+ QCowL2Meta *l2meta = *pl2meta;
+
+ while (l2meta != NULL) {
+ QCowL2Meta *next;
+
+ if (link_l2) {
+ ret = qcow2_alloc_cluster_link_l2(bs, l2meta);
+ if (ret) {
+ goto out;
+ }
+ } else {
+ qcow2_alloc_cluster_abort(bs, l2meta);
+ }
+
+ /* Take the request off the list of running requests */
+ QLIST_REMOVE(l2meta, next_in_flight);
+
+ qemu_co_queue_restart_all(&l2meta->dependent_requests);
+
+ next = l2meta->next;
+ g_free(l2meta);
+ l2meta = next;
+ }
+out:
+ *pl2meta = l2meta;
+ return ret;
+}
+
+static coroutine_fn int
+qcow2_co_preadv_encrypted(BlockDriverState *bs,
+ uint64_t host_offset,
+ uint64_t offset,
+ uint64_t bytes,
+ QEMUIOVector *qiov,
+ uint64_t qiov_offset)
+{
+ int ret;
+ BDRVQcow2State *s = bs->opaque;
+ uint8_t *buf;
+
+ assert(bs->encrypted && s->crypto);
+ assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
+
+ /*
+ * For encrypted images, read everything into a temporary
+ * contiguous buffer on which the AES functions can work.
+ * Also, decryption in a separate buffer is better as it
+ * prevents the guest from learning information about the
+ * encrypted nature of the virtual disk.
+ */
+
+ buf = qemu_try_blockalign(s->data_file->bs, bytes);
+ if (buf == NULL) {
+ return -ENOMEM;
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+ ret = bdrv_co_pread(s->data_file, host_offset, bytes, buf, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ if (qcow2_co_decrypt(bs, host_offset, offset, buf, bytes) < 0)
+ {
+ ret = -EIO;
+ goto fail;
+ }
+ qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes);
+
+fail:
+ qemu_vfree(buf);
+
+ return ret;
+}
+
+typedef struct Qcow2AioTask {
+ AioTask task;
+
+ BlockDriverState *bs;
+ QCow2SubclusterType subcluster_type; /* only for read */
+ uint64_t host_offset; /* or l2_entry for compressed read */
+ uint64_t offset;
+ uint64_t bytes;
+ QEMUIOVector *qiov;
+ uint64_t qiov_offset;
+ QCowL2Meta *l2meta; /* only for write */
+} Qcow2AioTask;
+
+static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task);
+static coroutine_fn int qcow2_add_task(BlockDriverState *bs,
+ AioTaskPool *pool,
+ AioTaskFunc func,
+ QCow2SubclusterType subcluster_type,
+ uint64_t host_offset,
+ uint64_t offset,
+ uint64_t bytes,
+ QEMUIOVector *qiov,
+ size_t qiov_offset,
+ QCowL2Meta *l2meta)
+{
+ Qcow2AioTask local_task;
+ Qcow2AioTask *task = pool ? g_new(Qcow2AioTask, 1) : &local_task;
+
+ *task = (Qcow2AioTask) {
+ .task.func = func,
+ .bs = bs,
+ .subcluster_type = subcluster_type,
+ .qiov = qiov,
+ .host_offset = host_offset,
+ .offset = offset,
+ .bytes = bytes,
+ .qiov_offset = qiov_offset,
+ .l2meta = l2meta,
+ };
+
+ trace_qcow2_add_task(qemu_coroutine_self(), bs, pool,
+ func == qcow2_co_preadv_task_entry ? "read" : "write",
+ subcluster_type, host_offset, offset, bytes,
+ qiov, qiov_offset);
+
+ if (!pool) {
+ return func(&task->task);
+ }
+
+ aio_task_pool_start_task(pool, &task->task);
+
+ return 0;
+}
+
+static coroutine_fn int qcow2_co_preadv_task(BlockDriverState *bs,
+ QCow2SubclusterType subc_type,
+ uint64_t host_offset,
+ uint64_t offset, uint64_t bytes,
+ QEMUIOVector *qiov,
+ size_t qiov_offset)
+{
+ BDRVQcow2State *s = bs->opaque;
+
+ switch (subc_type) {
+ case QCOW2_SUBCLUSTER_ZERO_PLAIN:
+ case QCOW2_SUBCLUSTER_ZERO_ALLOC:
+ /* Both zero types are handled in qcow2_co_preadv_part */
+ g_assert_not_reached();
+
+ case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN:
+ case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC:
+ assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */
+
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
+ return bdrv_co_preadv_part(bs->backing, offset, bytes,
+ qiov, qiov_offset, 0);
+
+ case QCOW2_SUBCLUSTER_COMPRESSED:
+ return qcow2_co_preadv_compressed(bs, host_offset,
+ offset, bytes, qiov, qiov_offset);
+
+ case QCOW2_SUBCLUSTER_NORMAL:
+ if (bs->encrypted) {
+ return qcow2_co_preadv_encrypted(bs, host_offset,
+ offset, bytes, qiov, qiov_offset);
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+ return bdrv_co_preadv_part(s->data_file, host_offset,
+ bytes, qiov, qiov_offset, 0);
+
+ default:
+ g_assert_not_reached();
+ }
+
+ g_assert_not_reached();
+}
+
+static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task)
+{
+ Qcow2AioTask *t = container_of(task, Qcow2AioTask, task);
+
+ assert(!t->l2meta);
+
+ return qcow2_co_preadv_task(t->bs, t->subcluster_type,
+ t->host_offset, t->offset, t->bytes,
+ t->qiov, t->qiov_offset);
+}
+
+static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs,
+ int64_t offset, int64_t bytes,
+ QEMUIOVector *qiov,
+ size_t qiov_offset,
+ BdrvRequestFlags flags)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int ret = 0;
+ unsigned int cur_bytes; /* number of bytes in current iteration */
+ uint64_t host_offset = 0;
+ QCow2SubclusterType type;
+ AioTaskPool *aio = NULL;
+
+ while (bytes != 0 && aio_task_pool_status(aio) == 0) {
+ /* prepare next request */
+ cur_bytes = MIN(bytes, INT_MAX);
+ if (s->crypto) {
+ cur_bytes = MIN(cur_bytes,
+ QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+ ret = qcow2_get_host_offset(bs, offset, &cur_bytes,
+ &host_offset, &type);
+ qemu_co_mutex_unlock(&s->lock);
+ if (ret < 0) {
+ goto out;
+ }
+
+ if (type == QCOW2_SUBCLUSTER_ZERO_PLAIN ||
+ type == QCOW2_SUBCLUSTER_ZERO_ALLOC ||
+ (type == QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN && !bs->backing) ||
+ (type == QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC && !bs->backing))
+ {
+ qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes);
+ } else {
+ if (!aio && cur_bytes != bytes) {
+ aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
+ }
+ ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, type,
+ host_offset, offset, cur_bytes,
+ qiov, qiov_offset, NULL);
+ if (ret < 0) {
+ goto out;
+ }
+ }
+
+ bytes -= cur_bytes;
+ offset += cur_bytes;
+ qiov_offset += cur_bytes;
+ }
+
+out:
+ if (aio) {
+ aio_task_pool_wait_all(aio);
+ if (ret == 0) {
+ ret = aio_task_pool_status(aio);
+ }
+ g_free(aio);
+ }
+
+ return ret;
+}
+
+/* Check if it's possible to merge a write request with the writing of
+ * the data from the COW regions */
+static bool merge_cow(uint64_t offset, unsigned bytes,
+ QEMUIOVector *qiov, size_t qiov_offset,
+ QCowL2Meta *l2meta)
+{
+ QCowL2Meta *m;
+
+ for (m = l2meta; m != NULL; m = m->next) {
+ /* If both COW regions are empty then there's nothing to merge */
+ if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) {
+ continue;
+ }
+
+ /* If COW regions are handled already, skip this too */
+ if (m->skip_cow) {
+ continue;
+ }
+
+ /*
+ * The write request should start immediately after the first
+ * COW region. This does not always happen because the area
+ * touched by the request can be larger than the one defined
+ * by @m (a single request can span an area consisting of a
+ * mix of previously unallocated and allocated clusters, that
+ * is why @l2meta is a list).
+ */
+ if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) {
+ /* In this case the request starts before this region */
+ assert(offset < l2meta_cow_start(m));
+ assert(m->cow_start.nb_bytes == 0);
+ continue;
+ }
+
+ /* The write request should end immediately before the second
+ * COW region (see above for why it does not always happen) */
+ if (m->offset + m->cow_end.offset != offset + bytes) {
+ assert(offset + bytes > m->offset + m->cow_end.offset);
+ assert(m->cow_end.nb_bytes == 0);
+ continue;
+ }
+
+ /* Make sure that adding both COW regions to the QEMUIOVector
+ * does not exceed IOV_MAX */
+ if (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) {
+ continue;
+ }
+
+ m->data_qiov = qiov;
+ m->data_qiov_offset = qiov_offset;
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * Return 1 if the COW regions read as zeroes, 0 if not, < 0 on error.
+ * Note that returning 0 does not guarantee non-zero data.
+ */
+static int is_zero_cow(BlockDriverState *bs, QCowL2Meta *m)
+{
+ /*
+ * This check is designed for optimization shortcut so it must be
+ * efficient.
+ * Instead of is_zero(), use bdrv_co_is_zero_fast() as it is
+ * faster (but not as accurate and can result in false negatives).
+ */
+ int ret = bdrv_co_is_zero_fast(bs, m->offset + m->cow_start.offset,
+ m->cow_start.nb_bytes);
+ if (ret <= 0) {
+ return ret;
+ }
+
+ return bdrv_co_is_zero_fast(bs, m->offset + m->cow_end.offset,
+ m->cow_end.nb_bytes);
+}
+
+static int handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta)
+{
+ BDRVQcow2State *s = bs->opaque;
+ QCowL2Meta *m;
+
+ if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) {
+ return 0;
+ }
+
+ if (bs->encrypted) {
+ return 0;
+ }
+
+ for (m = l2meta; m != NULL; m = m->next) {
+ int ret;
+ uint64_t start_offset = m->alloc_offset + m->cow_start.offset;
+ unsigned nb_bytes = m->cow_end.offset + m->cow_end.nb_bytes -
+ m->cow_start.offset;
+
+ if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) {
+ continue;
+ }
+
+ ret = is_zero_cow(bs, m);
+ if (ret < 0) {
+ return ret;
+ } else if (ret == 0) {
+ continue;
+ }
+
+ /*
+ * instead of writing zero COW buffers,
+ * efficiently zero out the whole clusters
+ */
+
+ ret = qcow2_pre_write_overlap_check(bs, 0, start_offset, nb_bytes,
+ true);
+ if (ret < 0) {
+ return ret;
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE);
+ ret = bdrv_co_pwrite_zeroes(s->data_file, start_offset, nb_bytes,
+ BDRV_REQ_NO_FALLBACK);
+ if (ret < 0) {
+ if (ret != -ENOTSUP && ret != -EAGAIN) {
+ return ret;
+ }
+ continue;
+ }
+
+ trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters);
+ m->skip_cow = true;
+ }
+ return 0;
+}
+
+/*
+ * qcow2_co_pwritev_task
+ * Called with s->lock unlocked
+ * l2meta - if not NULL, qcow2_co_pwritev_task() will consume it. Caller must
+ * not use it somehow after qcow2_co_pwritev_task() call
+ */
+static coroutine_fn int qcow2_co_pwritev_task(BlockDriverState *bs,
+ uint64_t host_offset,
+ uint64_t offset, uint64_t bytes,
+ QEMUIOVector *qiov,
+ uint64_t qiov_offset,
+ QCowL2Meta *l2meta)
+{
+ int ret;
+ BDRVQcow2State *s = bs->opaque;
+ void *crypt_buf = NULL;
+ QEMUIOVector encrypted_qiov;
+
+ if (bs->encrypted) {
+ assert(s->crypto);
+ assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size);
+ crypt_buf = qemu_try_blockalign(bs->file->bs, bytes);
+ if (crypt_buf == NULL) {
+ ret = -ENOMEM;
+ goto out_unlocked;
+ }
+ qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes);
+
+ if (qcow2_co_encrypt(bs, host_offset, offset, crypt_buf, bytes) < 0) {
+ ret = -EIO;
+ goto out_unlocked;
+ }
+
+ qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes);
+ qiov = &encrypted_qiov;
+ qiov_offset = 0;
+ }
+
+ /* Try to efficiently initialize the physical space with zeroes */
+ ret = handle_alloc_space(bs, l2meta);
+ if (ret < 0) {
+ goto out_unlocked;
+ }
+
+ /*
+ * If we need to do COW, check if it's possible to merge the
+ * writing of the guest data together with that of the COW regions.
+ * If it's not possible (or not necessary) then write the
+ * guest data now.
+ */
+ if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) {
+ BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
+ trace_qcow2_writev_data(qemu_coroutine_self(), host_offset);
+ ret = bdrv_co_pwritev_part(s->data_file, host_offset,
+ bytes, qiov, qiov_offset, 0);
+ if (ret < 0) {
+ goto out_unlocked;
+ }
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+
+ ret = qcow2_handle_l2meta(bs, &l2meta, true);
+ goto out_locked;
+
+out_unlocked:
+ qemu_co_mutex_lock(&s->lock);
+
+out_locked:
+ qcow2_handle_l2meta(bs, &l2meta, false);
+ qemu_co_mutex_unlock(&s->lock);
+
+ qemu_vfree(crypt_buf);
+
+ return ret;
+}
+
+static coroutine_fn int qcow2_co_pwritev_task_entry(AioTask *task)
+{
+ Qcow2AioTask *t = container_of(task, Qcow2AioTask, task);
+
+ assert(!t->subcluster_type);
+
+ return qcow2_co_pwritev_task(t->bs, t->host_offset,
+ t->offset, t->bytes, t->qiov, t->qiov_offset,
+ t->l2meta);
+}
+
+static coroutine_fn int qcow2_co_pwritev_part(
+ BlockDriverState *bs, int64_t offset, int64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset, BdrvRequestFlags flags)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int offset_in_cluster;
+ int ret;
+ unsigned int cur_bytes; /* number of sectors in current iteration */
+ uint64_t host_offset;
+ QCowL2Meta *l2meta = NULL;
+ AioTaskPool *aio = NULL;
+
+ trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes);
+
+ while (bytes != 0 && aio_task_pool_status(aio) == 0) {
+
+ l2meta = NULL;
+
+ trace_qcow2_writev_start_part(qemu_coroutine_self());
+ offset_in_cluster = offset_into_cluster(s, offset);
+ cur_bytes = MIN(bytes, INT_MAX);
+ if (bs->encrypted) {
+ cur_bytes = MIN(cur_bytes,
+ QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
+ - offset_in_cluster);
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+
+ ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes,
+ &host_offset, &l2meta);
+ if (ret < 0) {
+ goto out_locked;
+ }
+
+ ret = qcow2_pre_write_overlap_check(bs, 0, host_offset,
+ cur_bytes, true);
+ if (ret < 0) {
+ goto out_locked;
+ }
+
+ qemu_co_mutex_unlock(&s->lock);
+
+ if (!aio && cur_bytes != bytes) {
+ aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
+ }
+ ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0,
+ host_offset, offset,
+ cur_bytes, qiov, qiov_offset, l2meta);
+ l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */
+ if (ret < 0) {
+ goto fail_nometa;
+ }
+
+ bytes -= cur_bytes;
+ offset += cur_bytes;
+ qiov_offset += cur_bytes;
+ trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes);
+ }
+ ret = 0;
+
+ qemu_co_mutex_lock(&s->lock);
+
+out_locked:
+ qcow2_handle_l2meta(bs, &l2meta, false);
+
+ qemu_co_mutex_unlock(&s->lock);
+
+fail_nometa:
+ if (aio) {
+ aio_task_pool_wait_all(aio);
+ if (ret == 0) {
+ ret = aio_task_pool_status(aio);
+ }
+ g_free(aio);
+ }
+
+ trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
+
+ return ret;
+}
+
+static int qcow2_inactivate(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int ret, result = 0;
+ Error *local_err = NULL;
+
+ qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err);
+ if (local_err != NULL) {
+ result = -EINVAL;
+ error_reportf_err(local_err, "Lost persistent bitmaps during "
+ "inactivation of node '%s': ",
+ bdrv_get_device_or_node_name(bs));
+ }
+
+ ret = qcow2_cache_flush(bs, s->l2_table_cache);
+ if (ret) {
+ result = ret;
+ error_report("Failed to flush the L2 table cache: %s",
+ strerror(-ret));
+ }
+
+ ret = qcow2_cache_flush(bs, s->refcount_block_cache);
+ if (ret) {
+ result = ret;
+ error_report("Failed to flush the refcount block cache: %s",
+ strerror(-ret));
+ }
+
+ if (result == 0) {
+ qcow2_mark_clean(bs);
+ }
+
+ return result;
+}
+
+static void qcow2_close(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ qemu_vfree(s->l1_table);
+ /* else pre-write overlap checks in cache_destroy may crash */
+ s->l1_table = NULL;
+
+ if (!(s->flags & BDRV_O_INACTIVE)) {
+ qcow2_inactivate(bs);
+ }
+
+ cache_clean_timer_del(bs);
+ qcow2_cache_destroy(s->l2_table_cache);
+ qcow2_cache_destroy(s->refcount_block_cache);
+
+ qcrypto_block_free(s->crypto);
+ s->crypto = NULL;
+ qapi_free_QCryptoBlockOpenOptions(s->crypto_opts);
+
+ g_free(s->unknown_header_fields);
+ cleanup_unknown_header_ext(bs);
+
+ g_free(s->image_data_file);
+ g_free(s->image_backing_file);
+ g_free(s->image_backing_format);
+
+ if (has_data_file(bs)) {
+ bdrv_unref_child(bs, s->data_file);
+ s->data_file = NULL;
+ }
+
+ qcow2_refcount_close(bs);
+ qcow2_free_snapshots(bs);
+}
+
+static void coroutine_fn qcow2_co_invalidate_cache(BlockDriverState *bs,
+ Error **errp)
+{
+ ERRP_GUARD();
+ BDRVQcow2State *s = bs->opaque;
+ int flags = s->flags;
+ QCryptoBlock *crypto = NULL;
+ QDict *options;
+ int ret;
+
+ /*
+ * Backing files are read-only which makes all of their metadata immutable,
+ * that means we don't have to worry about reopening them here.
+ */
+
+ crypto = s->crypto;
+ s->crypto = NULL;
+
+ qcow2_close(bs);
+
+ memset(s, 0, sizeof(BDRVQcow2State));
+ options = qdict_clone_shallow(bs->options);
+
+ flags &= ~BDRV_O_INACTIVE;
+ qemu_co_mutex_lock(&s->lock);
+ ret = qcow2_do_open(bs, options, flags, errp);
+ qemu_co_mutex_unlock(&s->lock);
+ qobject_unref(options);
+ if (ret < 0) {
+ error_prepend(errp, "Could not reopen qcow2 layer: ");
+ bs->drv = NULL;
+ return;
+ }
+
+ s->crypto = crypto;
+}
+
+static size_t header_ext_add(char *buf, uint32_t magic, const void *s,
+ size_t len, size_t buflen)
+{
+ QCowExtension *ext_backing_fmt = (QCowExtension*) buf;
+ size_t ext_len = sizeof(QCowExtension) + ((len + 7) & ~7);
+
+ if (buflen < ext_len) {
+ return -ENOSPC;
+ }
+
+ *ext_backing_fmt = (QCowExtension) {
+ .magic = cpu_to_be32(magic),
+ .len = cpu_to_be32(len),
+ };
+
+ if (len) {
+ memcpy(buf + sizeof(QCowExtension), s, len);
+ }
+
+ return ext_len;
+}
+
+/*
+ * Updates the qcow2 header, including the variable length parts of it, i.e.
+ * the backing file name and all extensions. qcow2 was not designed to allow
+ * such changes, so if we run out of space (we can only use the first cluster)
+ * this function may fail.
+ *
+ * Returns 0 on success, -errno in error cases.
+ */
+int qcow2_update_header(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ QCowHeader *header;
+ char *buf;
+ size_t buflen = s->cluster_size;
+ int ret;
+ uint64_t total_size;
+ uint32_t refcount_table_clusters;
+ size_t header_length;
+ Qcow2UnknownHeaderExtension *uext;
+
+ buf = qemu_blockalign(bs, buflen);
+
+ /* Header structure */
+ header = (QCowHeader*) buf;
+
+ if (buflen < sizeof(*header)) {
+ ret = -ENOSPC;
+ goto fail;
+ }
+
+ header_length = sizeof(*header) + s->unknown_header_fields_size;
+ total_size = bs->total_sectors * BDRV_SECTOR_SIZE;
+ refcount_table_clusters = s->refcount_table_size >> (s->cluster_bits - 3);
+
+ ret = validate_compression_type(s, NULL);
+ if (ret) {
+ goto fail;
+ }
+
+ *header = (QCowHeader) {
+ /* Version 2 fields */
+ .magic = cpu_to_be32(QCOW_MAGIC),
+ .version = cpu_to_be32(s->qcow_version),
+ .backing_file_offset = 0,
+ .backing_file_size = 0,
+ .cluster_bits = cpu_to_be32(s->cluster_bits),
+ .size = cpu_to_be64(total_size),
+ .crypt_method = cpu_to_be32(s->crypt_method_header),
+ .l1_size = cpu_to_be32(s->l1_size),
+ .l1_table_offset = cpu_to_be64(s->l1_table_offset),
+ .refcount_table_offset = cpu_to_be64(s->refcount_table_offset),
+ .refcount_table_clusters = cpu_to_be32(refcount_table_clusters),
+ .nb_snapshots = cpu_to_be32(s->nb_snapshots),
+ .snapshots_offset = cpu_to_be64(s->snapshots_offset),
+
+ /* Version 3 fields */
+ .incompatible_features = cpu_to_be64(s->incompatible_features),
+ .compatible_features = cpu_to_be64(s->compatible_features),
+ .autoclear_features = cpu_to_be64(s->autoclear_features),
+ .refcount_order = cpu_to_be32(s->refcount_order),
+ .header_length = cpu_to_be32(header_length),
+ .compression_type = s->compression_type,
+ };
+
+ /* For older versions, write a shorter header */
+ switch (s->qcow_version) {
+ case 2:
+ ret = offsetof(QCowHeader, incompatible_features);
+ break;
+ case 3:
+ ret = sizeof(*header);
+ break;
+ default:
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ buf += ret;
+ buflen -= ret;
+ memset(buf, 0, buflen);
+
+ /* Preserve any unknown field in the header */
+ if (s->unknown_header_fields_size) {
+ if (buflen < s->unknown_header_fields_size) {
+ ret = -ENOSPC;
+ goto fail;
+ }
+
+ memcpy(buf, s->unknown_header_fields, s->unknown_header_fields_size);
+ buf += s->unknown_header_fields_size;
+ buflen -= s->unknown_header_fields_size;
+ }
+
+ /* Backing file format header extension */
+ if (s->image_backing_format) {
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT,
+ s->image_backing_format,
+ strlen(s->image_backing_format),
+ buflen);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ buf += ret;
+ buflen -= ret;
+ }
+
+ /* External data file header extension */
+ if (has_data_file(bs) && s->image_data_file) {
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE,
+ s->image_data_file, strlen(s->image_data_file),
+ buflen);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ buf += ret;
+ buflen -= ret;
+ }
+
+ /* Full disk encryption header pointer extension */
+ if (s->crypto_header.offset != 0) {
+ s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset);
+ s->crypto_header.length = cpu_to_be64(s->crypto_header.length);
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER,
+ &s->crypto_header, sizeof(s->crypto_header),
+ buflen);
+ s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset);
+ s->crypto_header.length = be64_to_cpu(s->crypto_header.length);
+ if (ret < 0) {
+ goto fail;
+ }
+ buf += ret;
+ buflen -= ret;
+ }
+
+ /*
+ * Feature table. A mere 8 feature names occupies 392 bytes, and
+ * when coupled with the v3 minimum header of 104 bytes plus the
+ * 8-byte end-of-extension marker, that would leave only 8 bytes
+ * for a backing file name in an image with 512-byte clusters.
+ * Thus, we choose to omit this header for cluster sizes 4k and
+ * smaller.
+ */
+ if (s->qcow_version >= 3 && s->cluster_size > 4096) {
+ static const Qcow2Feature features[] = {
+ {
+ .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
+ .bit = QCOW2_INCOMPAT_DIRTY_BITNR,
+ .name = "dirty bit",
+ },
+ {
+ .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
+ .bit = QCOW2_INCOMPAT_CORRUPT_BITNR,
+ .name = "corrupt bit",
+ },
+ {
+ .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
+ .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR,
+ .name = "external data file",
+ },
+ {
+ .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
+ .bit = QCOW2_INCOMPAT_COMPRESSION_BITNR,
+ .name = "compression type",
+ },
+ {
+ .type = QCOW2_FEAT_TYPE_INCOMPATIBLE,
+ .bit = QCOW2_INCOMPAT_EXTL2_BITNR,
+ .name = "extended L2 entries",
+ },
+ {
+ .type = QCOW2_FEAT_TYPE_COMPATIBLE,
+ .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
+ .name = "lazy refcounts",
+ },
+ {
+ .type = QCOW2_FEAT_TYPE_AUTOCLEAR,
+ .bit = QCOW2_AUTOCLEAR_BITMAPS_BITNR,
+ .name = "bitmaps",
+ },
+ {
+ .type = QCOW2_FEAT_TYPE_AUTOCLEAR,
+ .bit = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR,
+ .name = "raw external data",
+ },
+ };
+
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE,
+ features, sizeof(features), buflen);
+ if (ret < 0) {
+ goto fail;
+ }
+ buf += ret;
+ buflen -= ret;
+ }
+
+ /* Bitmap extension */
+ if (s->nb_bitmaps > 0) {
+ Qcow2BitmapHeaderExt bitmaps_header = {
+ .nb_bitmaps = cpu_to_be32(s->nb_bitmaps),
+ .bitmap_directory_size =
+ cpu_to_be64(s->bitmap_directory_size),
+ .bitmap_directory_offset =
+ cpu_to_be64(s->bitmap_directory_offset)
+ };
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS,
+ &bitmaps_header, sizeof(bitmaps_header),
+ buflen);
+ if (ret < 0) {
+ goto fail;
+ }
+ buf += ret;
+ buflen -= ret;
+ }
+
+ /* Keep unknown header extensions */
+ QLIST_FOREACH(uext, &s->unknown_header_ext, next) {
+ ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ buf += ret;
+ buflen -= ret;
+ }
+
+ /* End of header extensions */
+ ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ buf += ret;
+ buflen -= ret;
+
+ /* Backing file name */
+ if (s->image_backing_file) {
+ size_t backing_file_len = strlen(s->image_backing_file);
+
+ if (buflen < backing_file_len) {
+ ret = -ENOSPC;
+ goto fail;
+ }
+
+ /* Using strncpy is ok here, since buf is not NUL-terminated. */
+ strncpy(buf, s->image_backing_file, buflen);
+
+ header->backing_file_offset = cpu_to_be64(buf - ((char*) header));
+ header->backing_file_size = cpu_to_be32(backing_file_len);
+ }
+
+ /* Write the new header */
+ ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = 0;
+fail:
+ qemu_vfree(header);
+ return ret;
+}
+
+static int qcow2_change_backing_file(BlockDriverState *bs,
+ const char *backing_file, const char *backing_fmt)
+{
+ BDRVQcow2State *s = bs->opaque;
+
+ /* Adding a backing file means that the external data file alone won't be
+ * enough to make sense of the content */
+ if (backing_file && data_file_is_raw(bs)) {
+ return -EINVAL;
+ }
+
+ if (backing_file && strlen(backing_file) > 1023) {
+ return -EINVAL;
+ }
+
+ pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
+ backing_file ?: "");
+ pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
+ pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
+
+ g_free(s->image_backing_file);
+ g_free(s->image_backing_format);
+
+ s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL;
+ s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL;
+
+ return qcow2_update_header(bs);
+}
+
+static int qcow2_set_up_encryption(BlockDriverState *bs,
+ QCryptoBlockCreateOptions *cryptoopts,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ QCryptoBlock *crypto = NULL;
+ int fmt, ret;
+
+ switch (cryptoopts->format) {
+ case Q_CRYPTO_BLOCK_FORMAT_LUKS:
+ fmt = QCOW_CRYPT_LUKS;
+ break;
+ case Q_CRYPTO_BLOCK_FORMAT_QCOW:
+ fmt = QCOW_CRYPT_AES;
+ break;
+ default:
+ error_setg(errp, "Crypto format not supported in qcow2");
+ return -EINVAL;
+ }
+
+ s->crypt_method_header = fmt;
+
+ crypto = qcrypto_block_create(cryptoopts, "encrypt.",
+ qcow2_crypto_hdr_init_func,
+ qcow2_crypto_hdr_write_func,
+ bs, errp);
+ if (!crypto) {
+ return -EINVAL;
+ }
+
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not write encryption header");
+ goto out;
+ }
+
+ ret = 0;
+ out:
+ qcrypto_block_free(crypto);
+ return ret;
+}
+
+/**
+ * Preallocates metadata structures for data clusters between @offset (in the
+ * guest disk) and @new_length (which is thus generally the new guest disk
+ * size).
+ *
+ * Returns: 0 on success, -errno on failure.
+ */
+static int coroutine_fn preallocate_co(BlockDriverState *bs, uint64_t offset,
+ uint64_t new_length, PreallocMode mode,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint64_t bytes;
+ uint64_t host_offset = 0;
+ int64_t file_length;
+ unsigned int cur_bytes;
+ int ret;
+ QCowL2Meta *meta = NULL, *m;
+
+ assert(offset <= new_length);
+ bytes = new_length - offset;
+
+ while (bytes) {
+ cur_bytes = MIN(bytes, QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size));
+ ret = qcow2_alloc_host_offset(bs, offset, &cur_bytes,
+ &host_offset, &meta);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Allocating clusters failed");
+ goto out;
+ }
+
+ for (m = meta; m != NULL; m = m->next) {
+ m->prealloc = true;
+ }
+
+ ret = qcow2_handle_l2meta(bs, &meta, true);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Mapping clusters failed");
+ goto out;
+ }
+
+ /* TODO Preallocate data if requested */
+
+ bytes -= cur_bytes;
+ offset += cur_bytes;
+ }
+
+ /*
+ * It is expected that the image file is large enough to actually contain
+ * all of the allocated clusters (otherwise we get failing reads after
+ * EOF). Extend the image to the last allocated sector.
+ */
+ file_length = bdrv_getlength(s->data_file->bs);
+ if (file_length < 0) {
+ error_setg_errno(errp, -file_length, "Could not get file size");
+ ret = file_length;
+ goto out;
+ }
+
+ if (host_offset + cur_bytes > file_length) {
+ if (mode == PREALLOC_MODE_METADATA) {
+ mode = PREALLOC_MODE_OFF;
+ }
+ ret = bdrv_co_truncate(s->data_file, host_offset + cur_bytes, false,
+ mode, 0, errp);
+ if (ret < 0) {
+ goto out;
+ }
+ }
+
+ ret = 0;
+
+out:
+ qcow2_handle_l2meta(bs, &meta, false);
+ return ret;
+}
+
+/* qcow2_refcount_metadata_size:
+ * @clusters: number of clusters to refcount (including data and L1/L2 tables)
+ * @cluster_size: size of a cluster, in bytes
+ * @refcount_order: refcount bits power-of-2 exponent
+ * @generous_increase: allow for the refcount table to be 1.5x as large as it
+ * needs to be
+ *
+ * Returns: Number of bytes required for refcount blocks and table metadata.
+ */
+int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
+ int refcount_order, bool generous_increase,
+ uint64_t *refblock_count)
+{
+ /*
+ * Every host cluster is reference-counted, including metadata (even
+ * refcount metadata is recursively included).
+ *
+ * An accurate formula for the size of refcount metadata size is difficult
+ * to derive. An easier method of calculation is finding the fixed point
+ * where no further refcount blocks or table clusters are required to
+ * reference count every cluster.
+ */
+ int64_t blocks_per_table_cluster = cluster_size / REFTABLE_ENTRY_SIZE;
+ int64_t refcounts_per_block = cluster_size * 8 / (1 << refcount_order);
+ int64_t table = 0; /* number of refcount table clusters */
+ int64_t blocks = 0; /* number of refcount block clusters */
+ int64_t last;
+ int64_t n = 0;
+
+ do {
+ last = n;
+ blocks = DIV_ROUND_UP(clusters + table + blocks, refcounts_per_block);
+ table = DIV_ROUND_UP(blocks, blocks_per_table_cluster);
+ n = clusters + blocks + table;
+
+ if (n == last && generous_increase) {
+ clusters += DIV_ROUND_UP(table, 2);
+ n = 0; /* force another loop */
+ generous_increase = false;
+ }
+ } while (n != last);
+
+ if (refblock_count) {
+ *refblock_count = blocks;
+ }
+
+ return (blocks + table) * cluster_size;
+}
+
+/**
+ * qcow2_calc_prealloc_size:
+ * @total_size: virtual disk size in bytes
+ * @cluster_size: cluster size in bytes
+ * @refcount_order: refcount bits power-of-2 exponent
+ * @extended_l2: true if the image has extended L2 entries
+ *
+ * Returns: Total number of bytes required for the fully allocated image
+ * (including metadata).
+ */
+static int64_t qcow2_calc_prealloc_size(int64_t total_size,
+ size_t cluster_size,
+ int refcount_order,
+ bool extended_l2)
+{
+ int64_t meta_size = 0;
+ uint64_t nl1e, nl2e;
+ int64_t aligned_total_size = ROUND_UP(total_size, cluster_size);
+ size_t l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
+
+ /* header: 1 cluster */
+ meta_size += cluster_size;
+
+ /* total size of L2 tables */
+ nl2e = aligned_total_size / cluster_size;
+ nl2e = ROUND_UP(nl2e, cluster_size / l2e_size);
+ meta_size += nl2e * l2e_size;
+
+ /* total size of L1 tables */
+ nl1e = nl2e * l2e_size / cluster_size;
+ nl1e = ROUND_UP(nl1e, cluster_size / L1E_SIZE);
+ meta_size += nl1e * L1E_SIZE;
+
+ /* total size of refcount table and blocks */
+ meta_size += qcow2_refcount_metadata_size(
+ (meta_size + aligned_total_size) / cluster_size,
+ cluster_size, refcount_order, false, NULL);
+
+ return meta_size + aligned_total_size;
+}
+
+static bool validate_cluster_size(size_t cluster_size, bool extended_l2,
+ Error **errp)
+{
+ int cluster_bits = ctz32(cluster_size);
+ if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS ||
+ (1 << cluster_bits) != cluster_size)
+ {
+ error_setg(errp, "Cluster size must be a power of two between %d and "
+ "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10));
+ return false;
+ }
+
+ if (extended_l2) {
+ unsigned min_cluster_size =
+ (1 << MIN_CLUSTER_BITS) * QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER;
+ if (cluster_size < min_cluster_size) {
+ error_setg(errp, "Extended L2 entries are only supported with "
+ "cluster sizes of at least %u bytes", min_cluster_size);
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, bool extended_l2,
+ Error **errp)
+{
+ size_t cluster_size;
+
+ cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE,
+ DEFAULT_CLUSTER_SIZE);
+ if (!validate_cluster_size(cluster_size, extended_l2, errp)) {
+ return 0;
+ }
+ return cluster_size;
+}
+
+static int qcow2_opt_get_version_del(QemuOpts *opts, Error **errp)
+{
+ char *buf;
+ int ret;
+
+ buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL);
+ if (!buf) {
+ ret = 3; /* default */
+ } else if (!strcmp(buf, "0.10")) {
+ ret = 2;
+ } else if (!strcmp(buf, "1.1")) {
+ ret = 3;
+ } else {
+ error_setg(errp, "Invalid compatibility level: '%s'", buf);
+ ret = -EINVAL;
+ }
+ g_free(buf);
+ return ret;
+}
+
+static uint64_t qcow2_opt_get_refcount_bits_del(QemuOpts *opts, int version,
+ Error **errp)
+{
+ uint64_t refcount_bits;
+
+ refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, 16);
+ if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) {
+ error_setg(errp, "Refcount width must be a power of two and may not "
+ "exceed 64 bits");
+ return 0;
+ }
+
+ if (version < 3 && refcount_bits != 16) {
+ error_setg(errp, "Different refcount widths than 16 bits require "
+ "compatibility level 1.1 or above (use compat=1.1 or "
+ "greater)");
+ return 0;
+ }
+
+ return refcount_bits;
+}
+
+static int coroutine_fn
+qcow2_co_create(BlockdevCreateOptions *create_options, Error **errp)
+{
+ BlockdevCreateOptionsQcow2 *qcow2_opts;
+ QDict *options;
+
+ /*
+ * Open the image file and write a minimal qcow2 header.
+ *
+ * We keep things simple and start with a zero-sized image. We also
+ * do without refcount blocks or a L1 table for now. We'll fix the
+ * inconsistency later.
+ *
+ * We do need a refcount table because growing the refcount table means
+ * allocating two new refcount blocks - the second of which would be at
+ * 2 GB for 64k clusters, and we don't want to have a 2 GB initial file
+ * size for any qcow2 image.
+ */
+ BlockBackend *blk = NULL;
+ BlockDriverState *bs = NULL;
+ BlockDriverState *data_bs = NULL;
+ QCowHeader *header;
+ size_t cluster_size;
+ int version;
+ int refcount_order;
+ uint64_t *refcount_table;
+ int ret;
+ uint8_t compression_type = QCOW2_COMPRESSION_TYPE_ZLIB;
+
+ assert(create_options->driver == BLOCKDEV_DRIVER_QCOW2);
+ qcow2_opts = &create_options->u.qcow2;
+
+ bs = bdrv_open_blockdev_ref(qcow2_opts->file, errp);
+ if (bs == NULL) {
+ return -EIO;
+ }
+
+ /* Validate options and set default values */
+ if (!QEMU_IS_ALIGNED(qcow2_opts->size, BDRV_SECTOR_SIZE)) {
+ error_setg(errp, "Image size must be a multiple of %u bytes",
+ (unsigned) BDRV_SECTOR_SIZE);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (qcow2_opts->has_version) {
+ switch (qcow2_opts->version) {
+ case BLOCKDEV_QCOW2_VERSION_V2:
+ version = 2;
+ break;
+ case BLOCKDEV_QCOW2_VERSION_V3:
+ version = 3;
+ break;
+ default:
+ g_assert_not_reached();
+ }
+ } else {
+ version = 3;
+ }
+
+ if (qcow2_opts->has_cluster_size) {
+ cluster_size = qcow2_opts->cluster_size;
+ } else {
+ cluster_size = DEFAULT_CLUSTER_SIZE;
+ }
+
+ if (!qcow2_opts->has_extended_l2) {
+ qcow2_opts->extended_l2 = false;
+ }
+ if (qcow2_opts->extended_l2) {
+ if (version < 3) {
+ error_setg(errp, "Extended L2 entries are only supported with "
+ "compatibility level 1.1 and above (use version=v3 or "
+ "greater)");
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+
+ if (!validate_cluster_size(cluster_size, qcow2_opts->extended_l2, errp)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!qcow2_opts->has_preallocation) {
+ qcow2_opts->preallocation = PREALLOC_MODE_OFF;
+ }
+ if (qcow2_opts->has_backing_file &&
+ qcow2_opts->preallocation != PREALLOC_MODE_OFF &&
+ !qcow2_opts->extended_l2)
+ {
+ error_setg(errp, "Backing file and preallocation can only be used at "
+ "the same time if extended_l2 is on");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (qcow2_opts->has_backing_fmt && !qcow2_opts->has_backing_file) {
+ error_setg(errp, "Backing format cannot be used without backing file");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!qcow2_opts->has_lazy_refcounts) {
+ qcow2_opts->lazy_refcounts = false;
+ }
+ if (version < 3 && qcow2_opts->lazy_refcounts) {
+ error_setg(errp, "Lazy refcounts only supported with compatibility "
+ "level 1.1 and above (use version=v3 or greater)");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!qcow2_opts->has_refcount_bits) {
+ qcow2_opts->refcount_bits = 16;
+ }
+ if (qcow2_opts->refcount_bits > 64 ||
+ !is_power_of_2(qcow2_opts->refcount_bits))
+ {
+ error_setg(errp, "Refcount width must be a power of two and may not "
+ "exceed 64 bits");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (version < 3 && qcow2_opts->refcount_bits != 16) {
+ error_setg(errp, "Different refcount widths than 16 bits require "
+ "compatibility level 1.1 or above (use version=v3 or "
+ "greater)");
+ ret = -EINVAL;
+ goto out;
+ }
+ refcount_order = ctz32(qcow2_opts->refcount_bits);
+
+ if (qcow2_opts->data_file_raw && !qcow2_opts->data_file) {
+ error_setg(errp, "data-file-raw requires data-file");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (qcow2_opts->data_file_raw && qcow2_opts->has_backing_file) {
+ error_setg(errp, "Backing file and data-file-raw cannot be used at "
+ "the same time");
+ ret = -EINVAL;
+ goto out;
+ }
+ if (qcow2_opts->data_file_raw &&
+ qcow2_opts->preallocation == PREALLOC_MODE_OFF)
+ {
+ /*
+ * data-file-raw means that "the external data file can be
+ * read as a consistent standalone raw image without looking
+ * at the qcow2 metadata." It does not say that the metadata
+ * must be ignored, though (and the qcow2 driver in fact does
+ * not ignore it), so the L1/L2 tables must be present and
+ * give a 1:1 mapping, so you get the same result regardless
+ * of whether you look at the metadata or whether you ignore
+ * it.
+ */
+ qcow2_opts->preallocation = PREALLOC_MODE_METADATA;
+
+ /*
+ * Cannot use preallocation with backing files, but giving a
+ * backing file when specifying data_file_raw is an error
+ * anyway.
+ */
+ assert(!qcow2_opts->has_backing_file);
+ }
+
+ if (qcow2_opts->data_file) {
+ if (version < 3) {
+ error_setg(errp, "External data files are only supported with "
+ "compatibility level 1.1 and above (use version=v3 or "
+ "greater)");
+ ret = -EINVAL;
+ goto out;
+ }
+ data_bs = bdrv_open_blockdev_ref(qcow2_opts->data_file, errp);
+ if (data_bs == NULL) {
+ ret = -EIO;
+ goto out;
+ }
+ }
+
+ if (qcow2_opts->has_compression_type &&
+ qcow2_opts->compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) {
+
+ ret = -EINVAL;
+
+ if (version < 3) {
+ error_setg(errp, "Non-zlib compression type is only supported with "
+ "compatibility level 1.1 and above (use version=v3 or "
+ "greater)");
+ goto out;
+ }
+
+ switch (qcow2_opts->compression_type) {
+#ifdef CONFIG_ZSTD
+ case QCOW2_COMPRESSION_TYPE_ZSTD:
+ break;
+#endif
+ default:
+ error_setg(errp, "Unknown compression type");
+ goto out;
+ }
+
+ compression_type = qcow2_opts->compression_type;
+ }
+
+ /* Create BlockBackend to write to the image */
+ blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL,
+ errp);
+ if (!blk) {
+ ret = -EPERM;
+ goto out;
+ }
+ blk_set_allow_write_beyond_eof(blk, true);
+
+ /* Write the header */
+ QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header));
+ header = g_malloc0(cluster_size);
+ *header = (QCowHeader) {
+ .magic = cpu_to_be32(QCOW_MAGIC),
+ .version = cpu_to_be32(version),
+ .cluster_bits = cpu_to_be32(ctz32(cluster_size)),
+ .size = cpu_to_be64(0),
+ .l1_table_offset = cpu_to_be64(0),
+ .l1_size = cpu_to_be32(0),
+ .refcount_table_offset = cpu_to_be64(cluster_size),
+ .refcount_table_clusters = cpu_to_be32(1),
+ .refcount_order = cpu_to_be32(refcount_order),
+ /* don't deal with endianness since compression_type is 1 byte long */
+ .compression_type = compression_type,
+ .header_length = cpu_to_be32(sizeof(*header)),
+ };
+
+ /* We'll update this to correct value later */
+ header->crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
+
+ if (qcow2_opts->lazy_refcounts) {
+ header->compatible_features |=
+ cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS);
+ }
+ if (data_bs) {
+ header->incompatible_features |=
+ cpu_to_be64(QCOW2_INCOMPAT_DATA_FILE);
+ }
+ if (qcow2_opts->data_file_raw) {
+ header->autoclear_features |=
+ cpu_to_be64(QCOW2_AUTOCLEAR_DATA_FILE_RAW);
+ }
+ if (compression_type != QCOW2_COMPRESSION_TYPE_ZLIB) {
+ header->incompatible_features |=
+ cpu_to_be64(QCOW2_INCOMPAT_COMPRESSION);
+ }
+
+ if (qcow2_opts->extended_l2) {
+ header->incompatible_features |=
+ cpu_to_be64(QCOW2_INCOMPAT_EXTL2);
+ }
+
+ ret = blk_pwrite(blk, 0, header, cluster_size, 0);
+ g_free(header);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not write qcow2 header");
+ goto out;
+ }
+
+ /* Write a refcount table with one refcount block */
+ refcount_table = g_malloc0(2 * cluster_size);
+ refcount_table[0] = cpu_to_be64(2 * cluster_size);
+ ret = blk_pwrite(blk, cluster_size, refcount_table, 2 * cluster_size, 0);
+ g_free(refcount_table);
+
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not write refcount table");
+ goto out;
+ }
+
+ blk_unref(blk);
+ blk = NULL;
+
+ /*
+ * And now open the image and make it consistent first (i.e. increase the
+ * refcount of the cluster that is occupied by the header and the refcount
+ * table)
+ */
+ options = qdict_new();
+ qdict_put_str(options, "driver", "qcow2");
+ qdict_put_str(options, "file", bs->node_name);
+ if (data_bs) {
+ qdict_put_str(options, "data-file", data_bs->node_name);
+ }
+ blk = blk_new_open(NULL, NULL, options,
+ BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH,
+ errp);
+ if (blk == NULL) {
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 "
+ "header and refcount table");
+ goto out;
+
+ } else if (ret != 0) {
+ error_report("Huh, first cluster in empty image is already in use?");
+ abort();
+ }
+
+ /* Set the external data file if necessary */
+ if (data_bs) {
+ BDRVQcow2State *s = blk_bs(blk)->opaque;
+ s->image_data_file = g_strdup(data_bs->filename);
+ }
+
+ /* Create a full header (including things like feature table) */
+ ret = qcow2_update_header(blk_bs(blk));
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not update qcow2 header");
+ goto out;
+ }
+
+ /* Okay, now that we have a valid image, let's give it the right size */
+ ret = blk_truncate(blk, qcow2_opts->size, false, qcow2_opts->preallocation,
+ 0, errp);
+ if (ret < 0) {
+ error_prepend(errp, "Could not resize image: ");
+ goto out;
+ }
+
+ /* Want a backing file? There you go. */
+ if (qcow2_opts->has_backing_file) {
+ const char *backing_format = NULL;
+
+ if (qcow2_opts->has_backing_fmt) {
+ backing_format = BlockdevDriver_str(qcow2_opts->backing_fmt);
+ }
+
+ ret = bdrv_change_backing_file(blk_bs(blk), qcow2_opts->backing_file,
+ backing_format, false);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not assign backing file '%s' "
+ "with format '%s'", qcow2_opts->backing_file,
+ backing_format);
+ goto out;
+ }
+ }
+
+ /* Want encryption? There you go. */
+ if (qcow2_opts->has_encrypt) {
+ ret = qcow2_set_up_encryption(blk_bs(blk), qcow2_opts->encrypt, errp);
+ if (ret < 0) {
+ goto out;
+ }
+ }
+
+ blk_unref(blk);
+ blk = NULL;
+
+ /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning.
+ * Using BDRV_O_NO_IO, since encryption is now setup we don't want to
+ * have to setup decryption context. We're not doing any I/O on the top
+ * level BlockDriverState, only lower layers, where BDRV_O_NO_IO does
+ * not have effect.
+ */
+ options = qdict_new();
+ qdict_put_str(options, "driver", "qcow2");
+ qdict_put_str(options, "file", bs->node_name);
+ if (data_bs) {
+ qdict_put_str(options, "data-file", data_bs->node_name);
+ }
+ blk = blk_new_open(NULL, NULL, options,
+ BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO,
+ errp);
+ if (blk == NULL) {
+ ret = -EIO;
+ goto out;
+ }
+
+ ret = 0;
+out:
+ blk_unref(blk);
+ bdrv_unref(bs);
+ bdrv_unref(data_bs);
+ return ret;
+}
+
+static int coroutine_fn qcow2_co_create_opts(BlockDriver *drv,
+ const char *filename,
+ QemuOpts *opts,
+ Error **errp)
+{
+ BlockdevCreateOptions *create_options = NULL;
+ QDict *qdict;
+ Visitor *v;
+ BlockDriverState *bs = NULL;
+ BlockDriverState *data_bs = NULL;
+ const char *val;
+ int ret;
+
+ /* Only the keyval visitor supports the dotted syntax needed for
+ * encryption, so go through a QDict before getting a QAPI type. Ignore
+ * options meant for the protocol layer so that the visitor doesn't
+ * complain. */
+ qdict = qemu_opts_to_qdict_filtered(opts, NULL, bdrv_qcow2.create_opts,
+ true);
+
+ /* Handle encryption options */
+ val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT);
+ if (val && !strcmp(val, "on")) {
+ qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow");
+ } else if (val && !strcmp(val, "off")) {
+ qdict_del(qdict, BLOCK_OPT_ENCRYPT);
+ }
+
+ val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT);
+ if (val && !strcmp(val, "aes")) {
+ qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow");
+ }
+
+ /* Convert compat=0.10/1.1 into compat=v2/v3, to be renamed into
+ * version=v2/v3 below. */
+ val = qdict_get_try_str(qdict, BLOCK_OPT_COMPAT_LEVEL);
+ if (val && !strcmp(val, "0.10")) {
+ qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v2");
+ } else if (val && !strcmp(val, "1.1")) {
+ qdict_put_str(qdict, BLOCK_OPT_COMPAT_LEVEL, "v3");
+ }
+
+ /* Change legacy command line options into QMP ones */
+ static const QDictRenames opt_renames[] = {
+ { BLOCK_OPT_BACKING_FILE, "backing-file" },
+ { BLOCK_OPT_BACKING_FMT, "backing-fmt" },
+ { BLOCK_OPT_CLUSTER_SIZE, "cluster-size" },
+ { BLOCK_OPT_LAZY_REFCOUNTS, "lazy-refcounts" },
+ { BLOCK_OPT_EXTL2, "extended-l2" },
+ { BLOCK_OPT_REFCOUNT_BITS, "refcount-bits" },
+ { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT },
+ { BLOCK_OPT_COMPAT_LEVEL, "version" },
+ { BLOCK_OPT_DATA_FILE_RAW, "data-file-raw" },
+ { BLOCK_OPT_COMPRESSION_TYPE, "compression-type" },
+ { NULL, NULL },
+ };
+
+ if (!qdict_rename_keys(qdict, opt_renames, errp)) {
+ ret = -EINVAL;
+ goto finish;
+ }
+
+ /* Create and open the file (protocol layer) */
+ ret = bdrv_create_file(filename, opts, errp);
+ if (ret < 0) {
+ goto finish;
+ }
+
+ bs = bdrv_open(filename, NULL, NULL,
+ BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
+ if (bs == NULL) {
+ ret = -EIO;
+ goto finish;
+ }
+
+ /* Create and open an external data file (protocol layer) */
+ val = qdict_get_try_str(qdict, BLOCK_OPT_DATA_FILE);
+ if (val) {
+ ret = bdrv_create_file(val, opts, errp);
+ if (ret < 0) {
+ goto finish;
+ }
+
+ data_bs = bdrv_open(val, NULL, NULL,
+ BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL,
+ errp);
+ if (data_bs == NULL) {
+ ret = -EIO;
+ goto finish;
+ }
+
+ qdict_del(qdict, BLOCK_OPT_DATA_FILE);
+ qdict_put_str(qdict, "data-file", data_bs->node_name);
+ }
+
+ /* Set 'driver' and 'node' options */
+ qdict_put_str(qdict, "driver", "qcow2");
+ qdict_put_str(qdict, "file", bs->node_name);
+
+ /* Now get the QAPI type BlockdevCreateOptions */
+ v = qobject_input_visitor_new_flat_confused(qdict, errp);
+ if (!v) {
+ ret = -EINVAL;
+ goto finish;
+ }
+
+ visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
+ visit_free(v);
+ if (!create_options) {
+ ret = -EINVAL;
+ goto finish;
+ }
+
+ /* Silently round up size */
+ create_options->u.qcow2.size = ROUND_UP(create_options->u.qcow2.size,
+ BDRV_SECTOR_SIZE);
+
+ /* Create the qcow2 image (format layer) */
+ ret = qcow2_co_create(create_options, errp);
+finish:
+ if (ret < 0) {
+ bdrv_co_delete_file_noerr(bs);
+ bdrv_co_delete_file_noerr(data_bs);
+ } else {
+ ret = 0;
+ }
+
+ qobject_unref(qdict);
+ bdrv_unref(bs);
+ bdrv_unref(data_bs);
+ qapi_free_BlockdevCreateOptions(create_options);
+ return ret;
+}
+
+
+static bool is_zero(BlockDriverState *bs, int64_t offset, int64_t bytes)
+{
+ int64_t nr;
+ int res;
+
+ /* Clamp to image length, before checking status of underlying sectors */
+ if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) {
+ bytes = bs->total_sectors * BDRV_SECTOR_SIZE - offset;
+ }
+
+ if (!bytes) {
+ return true;
+ }
+
+ /*
+ * bdrv_block_status_above doesn't merge different types of zeros, for
+ * example, zeros which come from the region which is unallocated in
+ * the whole backing chain, and zeros which come because of a short
+ * backing file. So, we need a loop.
+ */
+ do {
+ res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL);
+ offset += nr;
+ bytes -= nr;
+ } while (res >= 0 && (res & BDRV_BLOCK_ZERO) && nr && bytes);
+
+ return res >= 0 && (res & BDRV_BLOCK_ZERO) && bytes == 0;
+}
+
+static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
+ int64_t offset, int64_t bytes, BdrvRequestFlags flags)
+{
+ int ret;
+ BDRVQcow2State *s = bs->opaque;
+
+ uint32_t head = offset_into_subcluster(s, offset);
+ uint32_t tail = ROUND_UP(offset + bytes, s->subcluster_size) -
+ (offset + bytes);
+
+ trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, bytes);
+ if (offset + bytes == bs->total_sectors * BDRV_SECTOR_SIZE) {
+ tail = 0;
+ }
+
+ if (head || tail) {
+ uint64_t off;
+ unsigned int nr;
+ QCow2SubclusterType type;
+
+ assert(head + bytes + tail <= s->subcluster_size);
+
+ /* check whether remainder of cluster already reads as zero */
+ if (!(is_zero(bs, offset - head, head) &&
+ is_zero(bs, offset + bytes, tail))) {
+ return -ENOTSUP;
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+ /* We can have new write after previous check */
+ offset -= head;
+ bytes = s->subcluster_size;
+ nr = s->subcluster_size;
+ ret = qcow2_get_host_offset(bs, offset, &nr, &off, &type);
+ if (ret < 0 ||
+ (type != QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN &&
+ type != QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC &&
+ type != QCOW2_SUBCLUSTER_ZERO_PLAIN &&
+ type != QCOW2_SUBCLUSTER_ZERO_ALLOC)) {
+ qemu_co_mutex_unlock(&s->lock);
+ return ret < 0 ? ret : -ENOTSUP;
+ }
+ } else {
+ qemu_co_mutex_lock(&s->lock);
+ }
+
+ trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes);
+
+ /* Whatever is left can use real zero subclusters */
+ ret = qcow2_subcluster_zeroize(bs, offset, bytes, flags);
+ qemu_co_mutex_unlock(&s->lock);
+
+ return ret;
+}
+
+static coroutine_fn int qcow2_co_pdiscard(BlockDriverState *bs,
+ int64_t offset, int64_t bytes)
+{
+ int ret;
+ BDRVQcow2State *s = bs->opaque;
+
+ /* If the image does not support QCOW_OFLAG_ZERO then discarding
+ * clusters could expose stale data from the backing file. */
+ if (s->qcow_version < 3 && bs->backing) {
+ return -ENOTSUP;
+ }
+
+ if (!QEMU_IS_ALIGNED(offset | bytes, s->cluster_size)) {
+ assert(bytes < s->cluster_size);
+ /* Ignore partial clusters, except for the special case of the
+ * complete partial cluster at the end of an unaligned file */
+ if (!QEMU_IS_ALIGNED(offset, s->cluster_size) ||
+ offset + bytes != bs->total_sectors * BDRV_SECTOR_SIZE) {
+ return -ENOTSUP;
+ }
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+ ret = qcow2_cluster_discard(bs, offset, bytes, QCOW2_DISCARD_REQUEST,
+ false);
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+}
+
+static int coroutine_fn
+qcow2_co_copy_range_from(BlockDriverState *bs,
+ BdrvChild *src, int64_t src_offset,
+ BdrvChild *dst, int64_t dst_offset,
+ int64_t bytes, BdrvRequestFlags read_flags,
+ BdrvRequestFlags write_flags)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int ret;
+ unsigned int cur_bytes; /* number of bytes in current iteration */
+ BdrvChild *child = NULL;
+ BdrvRequestFlags cur_write_flags;
+
+ assert(!bs->encrypted);
+ qemu_co_mutex_lock(&s->lock);
+
+ while (bytes != 0) {
+ uint64_t copy_offset = 0;
+ QCow2SubclusterType type;
+ /* prepare next request */
+ cur_bytes = MIN(bytes, INT_MAX);
+ cur_write_flags = write_flags;
+
+ ret = qcow2_get_host_offset(bs, src_offset, &cur_bytes,
+ &copy_offset, &type);
+ if (ret < 0) {
+ goto out;
+ }
+
+ switch (type) {
+ case QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN:
+ case QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC:
+ if (bs->backing && bs->backing->bs) {
+ int64_t backing_length = bdrv_getlength(bs->backing->bs);
+ if (src_offset >= backing_length) {
+ cur_write_flags |= BDRV_REQ_ZERO_WRITE;
+ } else {
+ child = bs->backing;
+ cur_bytes = MIN(cur_bytes, backing_length - src_offset);
+ copy_offset = src_offset;
+ }
+ } else {
+ cur_write_flags |= BDRV_REQ_ZERO_WRITE;
+ }
+ break;
+
+ case QCOW2_SUBCLUSTER_ZERO_PLAIN:
+ case QCOW2_SUBCLUSTER_ZERO_ALLOC:
+ cur_write_flags |= BDRV_REQ_ZERO_WRITE;
+ break;
+
+ case QCOW2_SUBCLUSTER_COMPRESSED:
+ ret = -ENOTSUP;
+ goto out;
+
+ case QCOW2_SUBCLUSTER_NORMAL:
+ child = s->data_file;
+ break;
+
+ default:
+ abort();
+ }
+ qemu_co_mutex_unlock(&s->lock);
+ ret = bdrv_co_copy_range_from(child,
+ copy_offset,
+ dst, dst_offset,
+ cur_bytes, read_flags, cur_write_flags);
+ qemu_co_mutex_lock(&s->lock);
+ if (ret < 0) {
+ goto out;
+ }
+
+ bytes -= cur_bytes;
+ src_offset += cur_bytes;
+ dst_offset += cur_bytes;
+ }
+ ret = 0;
+
+out:
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+}
+
+static int coroutine_fn
+qcow2_co_copy_range_to(BlockDriverState *bs,
+ BdrvChild *src, int64_t src_offset,
+ BdrvChild *dst, int64_t dst_offset,
+ int64_t bytes, BdrvRequestFlags read_flags,
+ BdrvRequestFlags write_flags)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int ret;
+ unsigned int cur_bytes; /* number of sectors in current iteration */
+ uint64_t host_offset;
+ QCowL2Meta *l2meta = NULL;
+
+ assert(!bs->encrypted);
+
+ qemu_co_mutex_lock(&s->lock);
+
+ while (bytes != 0) {
+
+ l2meta = NULL;
+
+ cur_bytes = MIN(bytes, INT_MAX);
+
+ /* TODO:
+ * If src->bs == dst->bs, we could simply copy by incrementing
+ * the refcnt, without copying user data.
+ * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */
+ ret = qcow2_alloc_host_offset(bs, dst_offset, &cur_bytes,
+ &host_offset, &l2meta);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = qcow2_pre_write_overlap_check(bs, 0, host_offset, cur_bytes,
+ true);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ qemu_co_mutex_unlock(&s->lock);
+ ret = bdrv_co_copy_range_to(src, src_offset, s->data_file, host_offset,
+ cur_bytes, read_flags, write_flags);
+ qemu_co_mutex_lock(&s->lock);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = qcow2_handle_l2meta(bs, &l2meta, true);
+ if (ret) {
+ goto fail;
+ }
+
+ bytes -= cur_bytes;
+ src_offset += cur_bytes;
+ dst_offset += cur_bytes;
+ }
+ ret = 0;
+
+fail:
+ qcow2_handle_l2meta(bs, &l2meta, false);
+
+ qemu_co_mutex_unlock(&s->lock);
+
+ trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
+
+ return ret;
+}
+
+static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset,
+ bool exact, PreallocMode prealloc,
+ BdrvRequestFlags flags, Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint64_t old_length;
+ int64_t new_l1_size;
+ int ret;
+ QDict *options;
+
+ if (prealloc != PREALLOC_MODE_OFF && prealloc != PREALLOC_MODE_METADATA &&
+ prealloc != PREALLOC_MODE_FALLOC && prealloc != PREALLOC_MODE_FULL)
+ {
+ error_setg(errp, "Unsupported preallocation mode '%s'",
+ PreallocMode_str(prealloc));
+ return -ENOTSUP;
+ }
+
+ if (!QEMU_IS_ALIGNED(offset, BDRV_SECTOR_SIZE)) {
+ error_setg(errp, "The new size must be a multiple of %u",
+ (unsigned) BDRV_SECTOR_SIZE);
+ return -EINVAL;
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+
+ /*
+ * Even though we store snapshot size for all images, it was not
+ * required until v3, so it is not safe to proceed for v2.
+ */
+ if (s->nb_snapshots && s->qcow_version < 3) {
+ error_setg(errp, "Can't resize a v2 image which has snapshots");
+ ret = -ENOTSUP;
+ goto fail;
+ }
+
+ /* See qcow2-bitmap.c for which bitmap scenarios prevent a resize. */
+ if (qcow2_truncate_bitmaps_check(bs, errp)) {
+ ret = -ENOTSUP;
+ goto fail;
+ }
+
+ old_length = bs->total_sectors * BDRV_SECTOR_SIZE;
+ new_l1_size = size_to_l1(s, offset);
+
+ if (offset < old_length) {
+ int64_t last_cluster, old_file_size;
+ if (prealloc != PREALLOC_MODE_OFF) {
+ error_setg(errp,
+ "Preallocation can't be used for shrinking an image");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ ret = qcow2_cluster_discard(bs, ROUND_UP(offset, s->cluster_size),
+ old_length - ROUND_UP(offset,
+ s->cluster_size),
+ QCOW2_DISCARD_ALWAYS, true);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to discard cropped clusters");
+ goto fail;
+ }
+
+ ret = qcow2_shrink_l1_table(bs, new_l1_size);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Failed to reduce the number of L2 tables");
+ goto fail;
+ }
+
+ ret = qcow2_shrink_reftable(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Failed to discard unused refblocks");
+ goto fail;
+ }
+
+ old_file_size = bdrv_getlength(bs->file->bs);
+ if (old_file_size < 0) {
+ error_setg_errno(errp, -old_file_size,
+ "Failed to inquire current file length");
+ ret = old_file_size;
+ goto fail;
+ }
+ last_cluster = qcow2_get_last_cluster(bs, old_file_size);
+ if (last_cluster < 0) {
+ error_setg_errno(errp, -last_cluster,
+ "Failed to find the last cluster");
+ ret = last_cluster;
+ goto fail;
+ }
+ if ((last_cluster + 1) * s->cluster_size < old_file_size) {
+ Error *local_err = NULL;
+
+ /*
+ * Do not pass @exact here: It will not help the user if
+ * we get an error here just because they wanted to shrink
+ * their qcow2 image (on a block device) with qemu-img.
+ * (And on the qcow2 layer, the @exact requirement is
+ * always fulfilled, so there is no need to pass it on.)
+ */
+ bdrv_co_truncate(bs->file, (last_cluster + 1) * s->cluster_size,
+ false, PREALLOC_MODE_OFF, 0, &local_err);
+ if (local_err) {
+ warn_reportf_err(local_err,
+ "Failed to truncate the tail of the image: ");
+ }
+ }
+ } else {
+ ret = qcow2_grow_l1_table(bs, new_l1_size, true);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to grow the L1 table");
+ goto fail;
+ }
+
+ if (data_file_is_raw(bs) && prealloc == PREALLOC_MODE_OFF) {
+ /*
+ * When creating a qcow2 image with data-file-raw, we enforce
+ * at least prealloc=metadata, so that the L1/L2 tables are
+ * fully allocated and reading from the data file will return
+ * the same data as reading from the qcow2 image. When the
+ * image is grown, we must consequently preallocate the
+ * metadata structures to cover the added area.
+ */
+ prealloc = PREALLOC_MODE_METADATA;
+ }
+ }
+
+ switch (prealloc) {
+ case PREALLOC_MODE_OFF:
+ if (has_data_file(bs)) {
+ /*
+ * If the caller wants an exact resize, the external data
+ * file should be resized to the exact target size, too,
+ * so we pass @exact here.
+ */
+ ret = bdrv_co_truncate(s->data_file, offset, exact, prealloc, 0,
+ errp);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+ break;
+
+ case PREALLOC_MODE_METADATA:
+ ret = preallocate_co(bs, old_length, offset, prealloc, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+ break;
+
+ case PREALLOC_MODE_FALLOC:
+ case PREALLOC_MODE_FULL:
+ {
+ int64_t allocation_start, host_offset, guest_offset;
+ int64_t clusters_allocated;
+ int64_t old_file_size, last_cluster, new_file_size;
+ uint64_t nb_new_data_clusters, nb_new_l2_tables;
+ bool subclusters_need_allocation = false;
+
+ /* With a data file, preallocation means just allocating the metadata
+ * and forwarding the truncate request to the data file */
+ if (has_data_file(bs)) {
+ ret = preallocate_co(bs, old_length, offset, prealloc, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+ break;
+ }
+
+ old_file_size = bdrv_getlength(bs->file->bs);
+ if (old_file_size < 0) {
+ error_setg_errno(errp, -old_file_size,
+ "Failed to inquire current file length");
+ ret = old_file_size;
+ goto fail;
+ }
+
+ last_cluster = qcow2_get_last_cluster(bs, old_file_size);
+ if (last_cluster >= 0) {
+ old_file_size = (last_cluster + 1) * s->cluster_size;
+ } else {
+ old_file_size = ROUND_UP(old_file_size, s->cluster_size);
+ }
+
+ nb_new_data_clusters = (ROUND_UP(offset, s->cluster_size) -
+ start_of_cluster(s, old_length)) >> s->cluster_bits;
+
+ /* This is an overestimation; we will not actually allocate space for
+ * these in the file but just make sure the new refcount structures are
+ * able to cover them so we will not have to allocate new refblocks
+ * while entering the data blocks in the potentially new L2 tables.
+ * (We do not actually care where the L2 tables are placed. Maybe they
+ * are already allocated or they can be placed somewhere before
+ * @old_file_size. It does not matter because they will be fully
+ * allocated automatically, so they do not need to be covered by the
+ * preallocation. All that matters is that we will not have to allocate
+ * new refcount structures for them.) */
+ nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters,
+ s->cluster_size / l2_entry_size(s));
+ /* The cluster range may not be aligned to L2 boundaries, so add one L2
+ * table for a potential head/tail */
+ nb_new_l2_tables++;
+
+ allocation_start = qcow2_refcount_area(bs, old_file_size,
+ nb_new_data_clusters +
+ nb_new_l2_tables,
+ true, 0, 0);
+ if (allocation_start < 0) {
+ error_setg_errno(errp, -allocation_start,
+ "Failed to resize refcount structures");
+ ret = allocation_start;
+ goto fail;
+ }
+
+ clusters_allocated = qcow2_alloc_clusters_at(bs, allocation_start,
+ nb_new_data_clusters);
+ if (clusters_allocated < 0) {
+ error_setg_errno(errp, -clusters_allocated,
+ "Failed to allocate data clusters");
+ ret = clusters_allocated;
+ goto fail;
+ }
+
+ assert(clusters_allocated == nb_new_data_clusters);
+
+ /* Allocate the data area */
+ new_file_size = allocation_start +
+ nb_new_data_clusters * s->cluster_size;
+ /*
+ * Image file grows, so @exact does not matter.
+ *
+ * If we need to zero out the new area, try first whether the protocol
+ * driver can already take care of this.
+ */
+ if (flags & BDRV_REQ_ZERO_WRITE) {
+ ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc,
+ BDRV_REQ_ZERO_WRITE, NULL);
+ if (ret >= 0) {
+ flags &= ~BDRV_REQ_ZERO_WRITE;
+ /* Ensure that we read zeroes and not backing file data */
+ subclusters_need_allocation = true;
+ }
+ } else {
+ ret = -1;
+ }
+ if (ret < 0) {
+ ret = bdrv_co_truncate(bs->file, new_file_size, false, prealloc, 0,
+ errp);
+ }
+ if (ret < 0) {
+ error_prepend(errp, "Failed to resize underlying file: ");
+ qcow2_free_clusters(bs, allocation_start,
+ nb_new_data_clusters * s->cluster_size,
+ QCOW2_DISCARD_OTHER);
+ goto fail;
+ }
+
+ /* Create the necessary L2 entries */
+ host_offset = allocation_start;
+ guest_offset = old_length;
+ while (nb_new_data_clusters) {
+ int64_t nb_clusters = MIN(
+ nb_new_data_clusters,
+ s->l2_slice_size - offset_to_l2_slice_index(s, guest_offset));
+ unsigned cow_start_length = offset_into_cluster(s, guest_offset);
+ QCowL2Meta allocation;
+ guest_offset = start_of_cluster(s, guest_offset);
+ allocation = (QCowL2Meta) {
+ .offset = guest_offset,
+ .alloc_offset = host_offset,
+ .nb_clusters = nb_clusters,
+ .cow_start = {
+ .offset = 0,
+ .nb_bytes = cow_start_length,
+ },
+ .cow_end = {
+ .offset = nb_clusters << s->cluster_bits,
+ .nb_bytes = 0,
+ },
+ .prealloc = !subclusters_need_allocation,
+ };
+ qemu_co_queue_init(&allocation.dependent_requests);
+
+ ret = qcow2_alloc_cluster_link_l2(bs, &allocation);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to update L2 tables");
+ qcow2_free_clusters(bs, host_offset,
+ nb_new_data_clusters * s->cluster_size,
+ QCOW2_DISCARD_OTHER);
+ goto fail;
+ }
+
+ guest_offset += nb_clusters * s->cluster_size;
+ host_offset += nb_clusters * s->cluster_size;
+ nb_new_data_clusters -= nb_clusters;
+ }
+ break;
+ }
+
+ default:
+ g_assert_not_reached();
+ }
+
+ if ((flags & BDRV_REQ_ZERO_WRITE) && offset > old_length) {
+ uint64_t zero_start = QEMU_ALIGN_UP(old_length, s->subcluster_size);
+
+ /*
+ * Use zero clusters as much as we can. qcow2_subcluster_zeroize()
+ * requires a subcluster-aligned start. The end may be unaligned if
+ * it is at the end of the image (which it is here).
+ */
+ if (offset > zero_start) {
+ ret = qcow2_subcluster_zeroize(bs, zero_start, offset - zero_start,
+ 0);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to zero out new clusters");
+ goto fail;
+ }
+ }
+
+ /* Write explicit zeros for the unaligned head */
+ if (zero_start > old_length) {
+ uint64_t len = MIN(zero_start, offset) - old_length;
+ uint8_t *buf = qemu_blockalign0(bs, len);
+ QEMUIOVector qiov;
+ qemu_iovec_init_buf(&qiov, buf, len);
+
+ qemu_co_mutex_unlock(&s->lock);
+ ret = qcow2_co_pwritev_part(bs, old_length, len, &qiov, 0, 0);
+ qemu_co_mutex_lock(&s->lock);
+
+ qemu_vfree(buf);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to zero out the new area");
+ goto fail;
+ }
+ }
+ }
+
+ if (prealloc != PREALLOC_MODE_OFF) {
+ /* Flush metadata before actually changing the image size */
+ ret = qcow2_write_caches(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Failed to flush the preallocated area to disk");
+ goto fail;
+ }
+ }
+
+ bs->total_sectors = offset / BDRV_SECTOR_SIZE;
+
+ /* write updated header.size */
+ offset = cpu_to_be64(offset);
+ ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size),
+ &offset, sizeof(offset));
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to update the image size");
+ goto fail;
+ }
+
+ s->l1_vm_state_index = new_l1_size;
+
+ /* Update cache sizes */
+ options = qdict_clone_shallow(bs->options);
+ ret = qcow2_update_options(bs, options, s->flags, errp);
+ qobject_unref(options);
+ if (ret < 0) {
+ goto fail;
+ }
+ ret = 0;
+fail:
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+}
+
+static coroutine_fn int
+qcow2_co_pwritev_compressed_task(BlockDriverState *bs,
+ uint64_t offset, uint64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int ret;
+ ssize_t out_len;
+ uint8_t *buf, *out_buf;
+ uint64_t cluster_offset;
+
+ assert(bytes == s->cluster_size || (bytes < s->cluster_size &&
+ (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS)));
+
+ buf = qemu_blockalign(bs, s->cluster_size);
+ if (bytes < s->cluster_size) {
+ /* Zero-pad last write if image size is not cluster aligned */
+ memset(buf + bytes, 0, s->cluster_size - bytes);
+ }
+ qemu_iovec_to_buf(qiov, qiov_offset, buf, bytes);
+
+ out_buf = g_malloc(s->cluster_size);
+
+ out_len = qcow2_co_compress(bs, out_buf, s->cluster_size - 1,
+ buf, s->cluster_size);
+ if (out_len == -ENOMEM) {
+ /* could not compress: write normal cluster */
+ ret = qcow2_co_pwritev_part(bs, offset, bytes, qiov, qiov_offset, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+ goto success;
+ } else if (out_len < 0) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+ ret = qcow2_alloc_compressed_cluster_offset(bs, offset, out_len,
+ &cluster_offset);
+ if (ret < 0) {
+ qemu_co_mutex_unlock(&s->lock);
+ goto fail;
+ }
+
+ ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len, true);
+ qemu_co_mutex_unlock(&s->lock);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ BLKDBG_EVENT(s->data_file, BLKDBG_WRITE_COMPRESSED);
+ ret = bdrv_co_pwrite(s->data_file, cluster_offset, out_len, out_buf, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+success:
+ ret = 0;
+fail:
+ qemu_vfree(buf);
+ g_free(out_buf);
+ return ret;
+}
+
+static coroutine_fn int qcow2_co_pwritev_compressed_task_entry(AioTask *task)
+{
+ Qcow2AioTask *t = container_of(task, Qcow2AioTask, task);
+
+ assert(!t->subcluster_type && !t->l2meta);
+
+ return qcow2_co_pwritev_compressed_task(t->bs, t->offset, t->bytes, t->qiov,
+ t->qiov_offset);
+}
+
+/*
+ * XXX: put compressed sectors first, then all the cluster aligned
+ * tables to avoid losing bytes in alignment
+ */
+static coroutine_fn int
+qcow2_co_pwritev_compressed_part(BlockDriverState *bs,
+ int64_t offset, int64_t bytes,
+ QEMUIOVector *qiov, size_t qiov_offset)
+{
+ BDRVQcow2State *s = bs->opaque;
+ AioTaskPool *aio = NULL;
+ int ret = 0;
+
+ if (has_data_file(bs)) {
+ return -ENOTSUP;
+ }
+
+ if (bytes == 0) {
+ /*
+ * align end of file to a sector boundary to ease reading with
+ * sector based I/Os
+ */
+ int64_t len = bdrv_getlength(bs->file->bs);
+ if (len < 0) {
+ return len;
+ }
+ return bdrv_co_truncate(bs->file, len, false, PREALLOC_MODE_OFF, 0,
+ NULL);
+ }
+
+ if (offset_into_cluster(s, offset)) {
+ return -EINVAL;
+ }
+
+ if (offset_into_cluster(s, bytes) &&
+ (offset + bytes) != (bs->total_sectors << BDRV_SECTOR_BITS)) {
+ return -EINVAL;
+ }
+
+ while (bytes && aio_task_pool_status(aio) == 0) {
+ uint64_t chunk_size = MIN(bytes, s->cluster_size);
+
+ if (!aio && chunk_size != bytes) {
+ aio = aio_task_pool_new(QCOW2_MAX_WORKERS);
+ }
+
+ ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_compressed_task_entry,
+ 0, 0, offset, chunk_size, qiov, qiov_offset, NULL);
+ if (ret < 0) {
+ break;
+ }
+ qiov_offset += chunk_size;
+ offset += chunk_size;
+ bytes -= chunk_size;
+ }
+
+ if (aio) {
+ aio_task_pool_wait_all(aio);
+ if (ret == 0) {
+ ret = aio_task_pool_status(aio);
+ }
+ g_free(aio);
+ }
+
+ return ret;
+}
+
+static int coroutine_fn
+qcow2_co_preadv_compressed(BlockDriverState *bs,
+ uint64_t l2_entry,
+ uint64_t offset,
+ uint64_t bytes,
+ QEMUIOVector *qiov,
+ size_t qiov_offset)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int ret = 0, csize;
+ uint64_t coffset;
+ uint8_t *buf, *out_buf;
+ int offset_in_cluster = offset_into_cluster(s, offset);
+
+ qcow2_parse_compressed_l2_entry(bs, l2_entry, &coffset, &csize);
+
+ buf = g_try_malloc(csize);
+ if (!buf) {
+ return -ENOMEM;
+ }
+
+ out_buf = qemu_blockalign(bs, s->cluster_size);
+
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
+ ret = bdrv_co_pread(bs->file, coffset, csize, buf, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ if (qcow2_co_decompress(bs, out_buf, s->cluster_size, buf, csize) < 0) {
+ ret = -EIO;
+ goto fail;
+ }
+
+ qemu_iovec_from_buf(qiov, qiov_offset, out_buf + offset_in_cluster, bytes);
+
+fail:
+ qemu_vfree(out_buf);
+ g_free(buf);
+
+ return ret;
+}
+
+static int make_completely_empty(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ Error *local_err = NULL;
+ int ret, l1_clusters;
+ int64_t offset;
+ uint64_t *new_reftable = NULL;
+ uint64_t rt_entry, l1_size2;
+ struct {
+ uint64_t l1_offset;
+ uint64_t reftable_offset;
+ uint32_t reftable_clusters;
+ } QEMU_PACKED l1_ofs_rt_ofs_cls;
+
+ ret = qcow2_cache_empty(bs, s->l2_table_cache);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = qcow2_cache_empty(bs, s->refcount_block_cache);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ /* Refcounts will be broken utterly */
+ ret = qcow2_mark_dirty(bs);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
+
+ l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE);
+ l1_size2 = (uint64_t)s->l1_size * L1E_SIZE;
+
+ /* After this call, neither the in-memory nor the on-disk refcount
+ * information accurately describe the actual references */
+
+ ret = bdrv_pwrite_zeroes(bs->file, s->l1_table_offset,
+ l1_clusters * s->cluster_size, 0);
+ if (ret < 0) {
+ goto fail_broken_refcounts;
+ }
+ memset(s->l1_table, 0, l1_size2);
+
+ BLKDBG_EVENT(bs->file, BLKDBG_EMPTY_IMAGE_PREPARE);
+
+ /* Overwrite enough clusters at the beginning of the sectors to place
+ * the refcount table, a refcount block and the L1 table in; this may
+ * overwrite parts of the existing refcount and L1 table, which is not
+ * an issue because the dirty flag is set, complete data loss is in fact
+ * desired and partial data loss is consequently fine as well */
+ ret = bdrv_pwrite_zeroes(bs->file, s->cluster_size,
+ (2 + l1_clusters) * s->cluster_size, 0);
+ /* This call (even if it failed overall) may have overwritten on-disk
+ * refcount structures; in that case, the in-memory refcount information
+ * will probably differ from the on-disk information which makes the BDS
+ * unusable */
+ if (ret < 0) {
+ goto fail_broken_refcounts;
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
+ BLKDBG_EVENT(bs->file, BLKDBG_REFTABLE_UPDATE);
+
+ /* "Create" an empty reftable (one cluster) directly after the image
+ * header and an empty L1 table three clusters after the image header;
+ * the cluster between those two will be used as the first refblock */
+ l1_ofs_rt_ofs_cls.l1_offset = cpu_to_be64(3 * s->cluster_size);
+ l1_ofs_rt_ofs_cls.reftable_offset = cpu_to_be64(s->cluster_size);
+ l1_ofs_rt_ofs_cls.reftable_clusters = cpu_to_be32(1);
+ ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_table_offset),
+ &l1_ofs_rt_ofs_cls, sizeof(l1_ofs_rt_ofs_cls));
+ if (ret < 0) {
+ goto fail_broken_refcounts;
+ }
+
+ s->l1_table_offset = 3 * s->cluster_size;
+
+ new_reftable = g_try_new0(uint64_t, s->cluster_size / REFTABLE_ENTRY_SIZE);
+ if (!new_reftable) {
+ ret = -ENOMEM;
+ goto fail_broken_refcounts;
+ }
+
+ s->refcount_table_offset = s->cluster_size;
+ s->refcount_table_size = s->cluster_size / REFTABLE_ENTRY_SIZE;
+ s->max_refcount_table_index = 0;
+
+ g_free(s->refcount_table);
+ s->refcount_table = new_reftable;
+ new_reftable = NULL;
+
+ /* Now the in-memory refcount information again corresponds to the on-disk
+ * information (reftable is empty and no refblocks (the refblock cache is
+ * empty)); however, this means some clusters (e.g. the image header) are
+ * referenced, but not refcounted, but the normal qcow2 code assumes that
+ * the in-memory information is always correct */
+
+ BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_ALLOC);
+
+ /* Enter the first refblock into the reftable */
+ rt_entry = cpu_to_be64(2 * s->cluster_size);
+ ret = bdrv_pwrite_sync(bs->file, s->cluster_size,
+ &rt_entry, sizeof(rt_entry));
+ if (ret < 0) {
+ goto fail_broken_refcounts;
+ }
+ s->refcount_table[0] = 2 * s->cluster_size;
+
+ s->free_cluster_index = 0;
+ assert(3 + l1_clusters <= s->refcount_block_size);
+ offset = qcow2_alloc_clusters(bs, 3 * s->cluster_size + l1_size2);
+ if (offset < 0) {
+ ret = offset;
+ goto fail_broken_refcounts;
+ } else if (offset > 0) {
+ error_report("First cluster in emptied image is in use");
+ abort();
+ }
+
+ /* Now finally the in-memory information corresponds to the on-disk
+ * structures and is correct */
+ ret = qcow2_mark_clean(bs);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = bdrv_truncate(bs->file, (3 + l1_clusters) * s->cluster_size, false,
+ PREALLOC_MODE_OFF, 0, &local_err);
+ if (ret < 0) {
+ error_report_err(local_err);
+ goto fail;
+ }
+
+ return 0;
+
+fail_broken_refcounts:
+ /* The BDS is unusable at this point. If we wanted to make it usable, we
+ * would have to call qcow2_refcount_close(), qcow2_refcount_init(),
+ * qcow2_check_refcounts(), qcow2_refcount_close() and qcow2_refcount_init()
+ * again. However, because the functions which could have caused this error
+ * path to be taken are used by those functions as well, it's very likely
+ * that that sequence will fail as well. Therefore, just eject the BDS. */
+ bs->drv = NULL;
+
+fail:
+ g_free(new_reftable);
+ return ret;
+}
+
+static int qcow2_make_empty(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ uint64_t offset, end_offset;
+ int step = QEMU_ALIGN_DOWN(INT_MAX, s->cluster_size);
+ int l1_clusters, ret = 0;
+
+ l1_clusters = DIV_ROUND_UP(s->l1_size, s->cluster_size / L1E_SIZE);
+
+ if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps &&
+ 3 + l1_clusters <= s->refcount_block_size &&
+ s->crypt_method_header != QCOW_CRYPT_LUKS &&
+ !has_data_file(bs)) {
+ /* The following function only works for qcow2 v3 images (it
+ * requires the dirty flag) and only as long as there are no
+ * features that reserve extra clusters (such as snapshots,
+ * LUKS header, or persistent bitmaps), because it completely
+ * empties the image. Furthermore, the L1 table and three
+ * additional clusters (image header, refcount table, one
+ * refcount block) have to fit inside one refcount block. It
+ * only resets the image file, i.e. does not work with an
+ * external data file. */
+ return make_completely_empty(bs);
+ }
+
+ /* This fallback code simply discards every active cluster; this is slow,
+ * but works in all cases */
+ end_offset = bs->total_sectors * BDRV_SECTOR_SIZE;
+ for (offset = 0; offset < end_offset; offset += step) {
+ /* As this function is generally used after committing an external
+ * snapshot, QCOW2_DISCARD_SNAPSHOT seems appropriate. Also, the
+ * default action for this kind of discard is to pass the discard,
+ * which will ideally result in an actually smaller image file, as
+ * is probably desired. */
+ ret = qcow2_cluster_discard(bs, offset, MIN(step, end_offset - offset),
+ QCOW2_DISCARD_SNAPSHOT, true);
+ if (ret < 0) {
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int ret;
+
+ qemu_co_mutex_lock(&s->lock);
+ ret = qcow2_write_caches(bs);
+ qemu_co_mutex_unlock(&s->lock);
+
+ return ret;
+}
+
+static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
+ Error **errp)
+{
+ Error *local_err = NULL;
+ BlockMeasureInfo *info;
+ uint64_t required = 0; /* bytes that contribute to required size */
+ uint64_t virtual_size; /* disk size as seen by guest */
+ uint64_t refcount_bits;
+ uint64_t l2_tables;
+ uint64_t luks_payload_size = 0;
+ size_t cluster_size;
+ int version;
+ char *optstr;
+ PreallocMode prealloc;
+ bool has_backing_file;
+ bool has_luks;
+ bool extended_l2;
+ size_t l2e_size;
+
+ /* Parse image creation options */
+ extended_l2 = qemu_opt_get_bool_del(opts, BLOCK_OPT_EXTL2, false);
+
+ cluster_size = qcow2_opt_get_cluster_size_del(opts, extended_l2,
+ &local_err);
+ if (local_err) {
+ goto err;
+ }
+
+ version = qcow2_opt_get_version_del(opts, &local_err);
+ if (local_err) {
+ goto err;
+ }
+
+ refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err);
+ if (local_err) {
+ goto err;
+ }
+
+ optstr = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
+ prealloc = qapi_enum_parse(&PreallocMode_lookup, optstr,
+ PREALLOC_MODE_OFF, &local_err);
+ g_free(optstr);
+ if (local_err) {
+ goto err;
+ }
+
+ optstr = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE);
+ has_backing_file = !!optstr;
+ g_free(optstr);
+
+ optstr = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT);
+ has_luks = optstr && strcmp(optstr, "luks") == 0;
+ g_free(optstr);
+
+ if (has_luks) {
+ g_autoptr(QCryptoBlockCreateOptions) create_opts = NULL;
+ QDict *cryptoopts = qcow2_extract_crypto_opts(opts, "luks", errp);
+ size_t headerlen;
+
+ create_opts = block_crypto_create_opts_init(cryptoopts, errp);
+ qobject_unref(cryptoopts);
+ if (!create_opts) {
+ goto err;
+ }
+
+ if (!qcrypto_block_calculate_payload_offset(create_opts,
+ "encrypt.",
+ &headerlen,
+ &local_err)) {
+ goto err;
+ }
+
+ luks_payload_size = ROUND_UP(headerlen, cluster_size);
+ }
+
+ virtual_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
+ virtual_size = ROUND_UP(virtual_size, cluster_size);
+
+ /* Check that virtual disk size is valid */
+ l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
+ l2_tables = DIV_ROUND_UP(virtual_size / cluster_size,
+ cluster_size / l2e_size);
+ if (l2_tables * L1E_SIZE > QCOW_MAX_L1_SIZE) {
+ error_setg(&local_err, "The image size is too large "
+ "(try using a larger cluster size)");
+ goto err;
+ }
+
+ /* Account for input image */
+ if (in_bs) {
+ int64_t ssize = bdrv_getlength(in_bs);
+ if (ssize < 0) {
+ error_setg_errno(&local_err, -ssize,
+ "Unable to get image virtual_size");
+ goto err;
+ }
+
+ virtual_size = ROUND_UP(ssize, cluster_size);
+
+ if (has_backing_file) {
+ /* We don't how much of the backing chain is shared by the input
+ * image and the new image file. In the worst case the new image's
+ * backing file has nothing in common with the input image. Be
+ * conservative and assume all clusters need to be written.
+ */
+ required = virtual_size;
+ } else {
+ int64_t offset;
+ int64_t pnum = 0;
+
+ for (offset = 0; offset < ssize; offset += pnum) {
+ int ret;
+
+ ret = bdrv_block_status_above(in_bs, NULL, offset,
+ ssize - offset, &pnum, NULL,
+ NULL);
+ if (ret < 0) {
+ error_setg_errno(&local_err, -ret,
+ "Unable to get block status");
+ goto err;
+ }
+
+ if (ret & BDRV_BLOCK_ZERO) {
+ /* Skip zero regions (safe with no backing file) */
+ } else if ((ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) ==
+ (BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED)) {
+ /* Extend pnum to end of cluster for next iteration */
+ pnum = ROUND_UP(offset + pnum, cluster_size) - offset;
+
+ /* Count clusters we've seen */
+ required += offset % cluster_size + pnum;
+ }
+ }
+ }
+ }
+
+ /* Take into account preallocation. Nothing special is needed for
+ * PREALLOC_MODE_METADATA since metadata is always counted.
+ */
+ if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) {
+ required = virtual_size;
+ }
+
+ info = g_new0(BlockMeasureInfo, 1);
+ info->fully_allocated = luks_payload_size +
+ qcow2_calc_prealloc_size(virtual_size, cluster_size,
+ ctz32(refcount_bits), extended_l2);
+
+ /*
+ * Remove data clusters that are not required. This overestimates the
+ * required size because metadata needed for the fully allocated file is
+ * still counted. Show bitmaps only if both source and destination
+ * would support them.
+ */
+ info->required = info->fully_allocated - virtual_size + required;
+ info->has_bitmaps = version >= 3 && in_bs &&
+ bdrv_supports_persistent_dirty_bitmap(in_bs);
+ if (info->has_bitmaps) {
+ info->bitmaps = qcow2_get_persistent_dirty_bitmap_size(in_bs,
+ cluster_size);
+ }
+ return info;
+
+err:
+ error_propagate(errp, local_err);
+ return NULL;
+}
+
+static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+ BDRVQcow2State *s = bs->opaque;
+ bdi->cluster_size = s->cluster_size;
+ bdi->vm_state_offset = qcow2_vm_state_offset(s);
+ bdi->is_dirty = s->incompatible_features & QCOW2_INCOMPAT_DIRTY;
+ return 0;
+}
+
+static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ ImageInfoSpecific *spec_info;
+ QCryptoBlockInfo *encrypt_info = NULL;
+
+ if (s->crypto != NULL) {
+ encrypt_info = qcrypto_block_get_info(s->crypto, errp);
+ if (!encrypt_info) {
+ return NULL;
+ }
+ }
+
+ spec_info = g_new(ImageInfoSpecific, 1);
+ *spec_info = (ImageInfoSpecific){
+ .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2,
+ .u.qcow2.data = g_new0(ImageInfoSpecificQCow2, 1),
+ };
+ if (s->qcow_version == 2) {
+ *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){
+ .compat = g_strdup("0.10"),
+ .refcount_bits = s->refcount_bits,
+ };
+ } else if (s->qcow_version == 3) {
+ Qcow2BitmapInfoList *bitmaps;
+ if (!qcow2_get_bitmap_info_list(bs, &bitmaps, errp)) {
+ qapi_free_ImageInfoSpecific(spec_info);
+ qapi_free_QCryptoBlockInfo(encrypt_info);
+ return NULL;
+ }
+ *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){
+ .compat = g_strdup("1.1"),
+ .lazy_refcounts = s->compatible_features &
+ QCOW2_COMPAT_LAZY_REFCOUNTS,
+ .has_lazy_refcounts = true,
+ .corrupt = s->incompatible_features &
+ QCOW2_INCOMPAT_CORRUPT,
+ .has_corrupt = true,
+ .has_extended_l2 = true,
+ .extended_l2 = has_subclusters(s),
+ .refcount_bits = s->refcount_bits,
+ .has_bitmaps = !!bitmaps,
+ .bitmaps = bitmaps,
+ .has_data_file = !!s->image_data_file,
+ .data_file = g_strdup(s->image_data_file),
+ .has_data_file_raw = has_data_file(bs),
+ .data_file_raw = data_file_is_raw(bs),
+ .compression_type = s->compression_type,
+ };
+ } else {
+ /* if this assertion fails, this probably means a new version was
+ * added without having it covered here */
+ assert(false);
+ }
+
+ if (encrypt_info) {
+ ImageInfoSpecificQCow2Encryption *qencrypt =
+ g_new(ImageInfoSpecificQCow2Encryption, 1);
+ switch (encrypt_info->format) {
+ case Q_CRYPTO_BLOCK_FORMAT_QCOW:
+ qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_AES;
+ break;
+ case Q_CRYPTO_BLOCK_FORMAT_LUKS:
+ qencrypt->format = BLOCKDEV_QCOW2_ENCRYPTION_FORMAT_LUKS;
+ qencrypt->u.luks = encrypt_info->u.luks;
+ break;
+ default:
+ abort();
+ }
+ /* Since we did shallow copy above, erase any pointers
+ * in the original info */
+ memset(&encrypt_info->u, 0, sizeof(encrypt_info->u));
+ qapi_free_QCryptoBlockInfo(encrypt_info);
+
+ spec_info->u.qcow2.data->has_encrypt = true;
+ spec_info->u.qcow2.data->encrypt = qencrypt;
+ }
+
+ return spec_info;
+}
+
+static int qcow2_has_zero_init(BlockDriverState *bs)
+{
+ BDRVQcow2State *s = bs->opaque;
+ bool preallocated;
+
+ if (qemu_in_coroutine()) {
+ qemu_co_mutex_lock(&s->lock);
+ }
+ /*
+ * Check preallocation status: Preallocated images have all L2
+ * tables allocated, nonpreallocated images have none. It is
+ * therefore enough to check the first one.
+ */
+ preallocated = s->l1_size > 0 && s->l1_table[0] != 0;
+ if (qemu_in_coroutine()) {
+ qemu_co_mutex_unlock(&s->lock);
+ }
+
+ if (!preallocated) {
+ return 1;
+ } else if (bs->encrypted) {
+ return 0;
+ } else {
+ return bdrv_has_zero_init(s->data_file->bs);
+ }
+}
+
+/*
+ * Check the request to vmstate. On success return
+ * qcow2_vm_state_offset(bs) + @pos
+ */
+static int64_t qcow2_check_vmstate_request(BlockDriverState *bs,
+ QEMUIOVector *qiov, int64_t pos)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int64_t vmstate_offset = qcow2_vm_state_offset(s);
+ int ret;
+
+ /* Incoming requests must be OK */
+ bdrv_check_qiov_request(pos, qiov->size, qiov, 0, &error_abort);
+
+ if (INT64_MAX - pos < vmstate_offset) {
+ return -EIO;
+ }
+
+ pos += vmstate_offset;
+ ret = bdrv_check_qiov_request(pos, qiov->size, qiov, 0, NULL);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return pos;
+}
+
+static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
+ int64_t pos)
+{
+ int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos);
+ if (offset < 0) {
+ return offset;
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE);
+ return bs->drv->bdrv_co_pwritev_part(bs, offset, qiov->size, qiov, 0, 0);
+}
+
+static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
+ int64_t pos)
+{
+ int64_t offset = qcow2_check_vmstate_request(bs, qiov, pos);
+ if (offset < 0) {
+ return offset;
+ }
+
+ BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD);
+ return bs->drv->bdrv_co_preadv_part(bs, offset, qiov->size, qiov, 0, 0);
+}
+
+/*
+ * Downgrades an image's version. To achieve this, any incompatible features
+ * have to be removed.
+ */
+static int qcow2_downgrade(BlockDriverState *bs, int target_version,
+ BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int current_version = s->qcow_version;
+ int ret;
+ int i;
+
+ /* This is qcow2_downgrade(), not qcow2_upgrade() */
+ assert(target_version < current_version);
+
+ /* There are no other versions (now) that you can downgrade to */
+ assert(target_version == 2);
+
+ if (s->refcount_order != 4) {
+ error_setg(errp, "compat=0.10 requires refcount_bits=16");
+ return -ENOTSUP;
+ }
+
+ if (has_data_file(bs)) {
+ error_setg(errp, "Cannot downgrade an image with a data file");
+ return -ENOTSUP;
+ }
+
+ /*
+ * If any internal snapshot has a different size than the current
+ * image size, or VM state size that exceeds 32 bits, downgrading
+ * is unsafe. Even though we would still use v3-compliant output
+ * to preserve that data, other v2 programs might not realize
+ * those optional fields are important.
+ */
+ for (i = 0; i < s->nb_snapshots; i++) {
+ if (s->snapshots[i].vm_state_size > UINT32_MAX ||
+ s->snapshots[i].disk_size != bs->total_sectors * BDRV_SECTOR_SIZE) {
+ error_setg(errp, "Internal snapshots prevent downgrade of image");
+ return -ENOTSUP;
+ }
+ }
+
+ /* clear incompatible features */
+ if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
+ ret = qcow2_mark_clean(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to make the image clean");
+ return ret;
+ }
+ }
+
+ /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in
+ * the first place; if that happens nonetheless, returning -ENOTSUP is the
+ * best thing to do anyway */
+
+ if (s->incompatible_features) {
+ error_setg(errp, "Cannot downgrade an image with incompatible features "
+ "%#" PRIx64 " set", s->incompatible_features);
+ return -ENOTSUP;
+ }
+
+ /* since we can ignore compatible features, we can set them to 0 as well */
+ s->compatible_features = 0;
+ /* if lazy refcounts have been used, they have already been fixed through
+ * clearing the dirty flag */
+
+ /* clearing autoclear features is trivial */
+ s->autoclear_features = 0;
+
+ ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to turn zero into data clusters");
+ return ret;
+ }
+
+ s->qcow_version = target_version;
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ s->qcow_version = current_version;
+ error_setg_errno(errp, -ret, "Failed to update the image header");
+ return ret;
+ }
+ return 0;
+}
+
+/*
+ * Upgrades an image's version. While newer versions encompass all
+ * features of older versions, some things may have to be presented
+ * differently.
+ */
+static int qcow2_upgrade(BlockDriverState *bs, int target_version,
+ BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ bool need_snapshot_update;
+ int current_version = s->qcow_version;
+ int i;
+ int ret;
+
+ /* This is qcow2_upgrade(), not qcow2_downgrade() */
+ assert(target_version > current_version);
+
+ /* There are no other versions (yet) that you can upgrade to */
+ assert(target_version == 3);
+
+ status_cb(bs, 0, 2, cb_opaque);
+
+ /*
+ * In v2, snapshots do not need to have extra data. v3 requires
+ * the 64-bit VM state size and the virtual disk size to be
+ * present.
+ * qcow2_write_snapshots() will always write the list in the
+ * v3-compliant format.
+ */
+ need_snapshot_update = false;
+ for (i = 0; i < s->nb_snapshots; i++) {
+ if (s->snapshots[i].extra_data_size <
+ sizeof_field(QCowSnapshotExtraData, vm_state_size_large) +
+ sizeof_field(QCowSnapshotExtraData, disk_size))
+ {
+ need_snapshot_update = true;
+ break;
+ }
+ }
+ if (need_snapshot_update) {
+ ret = qcow2_write_snapshots(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to update the snapshot table");
+ return ret;
+ }
+ }
+ status_cb(bs, 1, 2, cb_opaque);
+
+ s->qcow_version = target_version;
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ s->qcow_version = current_version;
+ error_setg_errno(errp, -ret, "Failed to update the image header");
+ return ret;
+ }
+ status_cb(bs, 2, 2, cb_opaque);
+
+ return 0;
+}
+
+typedef enum Qcow2AmendOperation {
+ /* This is the value Qcow2AmendHelperCBInfo::last_operation will be
+ * statically initialized to so that the helper CB can discern the first
+ * invocation from an operation change */
+ QCOW2_NO_OPERATION = 0,
+
+ QCOW2_UPGRADING,
+ QCOW2_UPDATING_ENCRYPTION,
+ QCOW2_CHANGING_REFCOUNT_ORDER,
+ QCOW2_DOWNGRADING,
+} Qcow2AmendOperation;
+
+typedef struct Qcow2AmendHelperCBInfo {
+ /* The code coordinating the amend operations should only modify
+ * these four fields; the rest will be managed by the CB */
+ BlockDriverAmendStatusCB *original_status_cb;
+ void *original_cb_opaque;
+
+ Qcow2AmendOperation current_operation;
+
+ /* Total number of operations to perform (only set once) */
+ int total_operations;
+
+ /* The following fields are managed by the CB */
+
+ /* Number of operations completed */
+ int operations_completed;
+
+ /* Cumulative offset of all completed operations */
+ int64_t offset_completed;
+
+ Qcow2AmendOperation last_operation;
+ int64_t last_work_size;
+} Qcow2AmendHelperCBInfo;
+
+static void qcow2_amend_helper_cb(BlockDriverState *bs,
+ int64_t operation_offset,
+ int64_t operation_work_size, void *opaque)
+{
+ Qcow2AmendHelperCBInfo *info = opaque;
+ int64_t current_work_size;
+ int64_t projected_work_size;
+
+ if (info->current_operation != info->last_operation) {
+ if (info->last_operation != QCOW2_NO_OPERATION) {
+ info->offset_completed += info->last_work_size;
+ info->operations_completed++;
+ }
+
+ info->last_operation = info->current_operation;
+ }
+
+ assert(info->total_operations > 0);
+ assert(info->operations_completed < info->total_operations);
+
+ info->last_work_size = operation_work_size;
+
+ current_work_size = info->offset_completed + operation_work_size;
+
+ /* current_work_size is the total work size for (operations_completed + 1)
+ * operations (which includes this one), so multiply it by the number of
+ * operations not covered and divide it by the number of operations
+ * covered to get a projection for the operations not covered */
+ projected_work_size = current_work_size * (info->total_operations -
+ info->operations_completed - 1)
+ / (info->operations_completed + 1);
+
+ info->original_status_cb(bs, info->offset_completed + operation_offset,
+ current_work_size + projected_work_size,
+ info->original_cb_opaque);
+}
+
+static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts,
+ BlockDriverAmendStatusCB *status_cb,
+ void *cb_opaque,
+ bool force,
+ Error **errp)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int old_version = s->qcow_version, new_version = old_version;
+ uint64_t new_size = 0;
+ const char *backing_file = NULL, *backing_format = NULL, *data_file = NULL;
+ bool lazy_refcounts = s->use_lazy_refcounts;
+ bool data_file_raw = data_file_is_raw(bs);
+ const char *compat = NULL;
+ int refcount_bits = s->refcount_bits;
+ int ret;
+ QemuOptDesc *desc = opts->list->desc;
+ Qcow2AmendHelperCBInfo helper_cb_info;
+ bool encryption_update = false;
+
+ while (desc && desc->name) {
+ if (!qemu_opt_find(opts, desc->name)) {
+ /* only change explicitly defined options */
+ desc++;
+ continue;
+ }
+
+ if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) {
+ compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL);
+ if (!compat) {
+ /* preserve default */
+ } else if (!strcmp(compat, "0.10") || !strcmp(compat, "v2")) {
+ new_version = 2;
+ } else if (!strcmp(compat, "1.1") || !strcmp(compat, "v3")) {
+ new_version = 3;
+ } else {
+ error_setg(errp, "Unknown compatibility level %s", compat);
+ return -EINVAL;
+ }
+ } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) {
+ new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0);
+ } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) {
+ backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
+ } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) {
+ backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
+ } else if (g_str_has_prefix(desc->name, "encrypt.")) {
+ if (!s->crypto) {
+ error_setg(errp,
+ "Can't amend encryption options - encryption not present");
+ return -EINVAL;
+ }
+ if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
+ error_setg(errp,
+ "Only LUKS encryption options can be amended");
+ return -ENOTSUP;
+ }
+ encryption_update = true;
+ } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) {
+ lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS,
+ lazy_refcounts);
+ } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) {
+ refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS,
+ refcount_bits);
+
+ if (refcount_bits <= 0 || refcount_bits > 64 ||
+ !is_power_of_2(refcount_bits))
+ {
+ error_setg(errp, "Refcount width must be a power of two and "
+ "may not exceed 64 bits");
+ return -EINVAL;
+ }
+ } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE)) {
+ data_file = qemu_opt_get(opts, BLOCK_OPT_DATA_FILE);
+ if (data_file && !has_data_file(bs)) {
+ error_setg(errp, "data-file can only be set for images that "
+ "use an external data file");
+ return -EINVAL;
+ }
+ } else if (!strcmp(desc->name, BLOCK_OPT_DATA_FILE_RAW)) {
+ data_file_raw = qemu_opt_get_bool(opts, BLOCK_OPT_DATA_FILE_RAW,
+ data_file_raw);
+ if (data_file_raw && !data_file_is_raw(bs)) {
+ error_setg(errp, "data-file-raw cannot be set on existing "
+ "images");
+ return -EINVAL;
+ }
+ } else {
+ /* if this point is reached, this probably means a new option was
+ * added without having it covered here */
+ abort();
+ }
+
+ desc++;
+ }
+
+ helper_cb_info = (Qcow2AmendHelperCBInfo){
+ .original_status_cb = status_cb,
+ .original_cb_opaque = cb_opaque,
+ .total_operations = (new_version != old_version)
+ + (s->refcount_bits != refcount_bits) +
+ (encryption_update == true)
+ };
+
+ /* Upgrade first (some features may require compat=1.1) */
+ if (new_version > old_version) {
+ helper_cb_info.current_operation = QCOW2_UPGRADING;
+ ret = qcow2_upgrade(bs, new_version, &qcow2_amend_helper_cb,
+ &helper_cb_info, errp);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ if (encryption_update) {
+ QDict *amend_opts_dict;
+ QCryptoBlockAmendOptions *amend_opts;
+
+ helper_cb_info.current_operation = QCOW2_UPDATING_ENCRYPTION;
+ amend_opts_dict = qcow2_extract_crypto_opts(opts, "luks", errp);
+ if (!amend_opts_dict) {
+ return -EINVAL;
+ }
+ amend_opts = block_crypto_amend_opts_init(amend_opts_dict, errp);
+ qobject_unref(amend_opts_dict);
+ if (!amend_opts) {
+ return -EINVAL;
+ }
+ ret = qcrypto_block_amend_options(s->crypto,
+ qcow2_crypto_hdr_read_func,
+ qcow2_crypto_hdr_write_func,
+ bs,
+ amend_opts,
+ force,
+ errp);
+ qapi_free_QCryptoBlockAmendOptions(amend_opts);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ if (s->refcount_bits != refcount_bits) {
+ int refcount_order = ctz32(refcount_bits);
+
+ if (new_version < 3 && refcount_bits != 16) {
+ error_setg(errp, "Refcount widths other than 16 bits require "
+ "compatibility level 1.1 or above (use compat=1.1 or "
+ "greater)");
+ return -EINVAL;
+ }
+
+ helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER;
+ ret = qcow2_change_refcount_order(bs, refcount_order,
+ &qcow2_amend_helper_cb,
+ &helper_cb_info, errp);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ /* data-file-raw blocks backing files, so clear it first if requested */
+ if (data_file_raw) {
+ s->autoclear_features |= QCOW2_AUTOCLEAR_DATA_FILE_RAW;
+ } else {
+ s->autoclear_features &= ~QCOW2_AUTOCLEAR_DATA_FILE_RAW;
+ }
+
+ if (data_file) {
+ g_free(s->image_data_file);
+ s->image_data_file = *data_file ? g_strdup(data_file) : NULL;
+ }
+
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to update the image header");
+ return ret;
+ }
+
+ if (backing_file || backing_format) {
+ if (g_strcmp0(backing_file, s->image_backing_file) ||
+ g_strcmp0(backing_format, s->image_backing_format)) {
+ error_setg(errp, "Cannot amend the backing file");
+ error_append_hint(errp,
+ "You can use 'qemu-img rebase' instead.\n");
+ return -EINVAL;
+ }
+ }
+
+ if (s->use_lazy_refcounts != lazy_refcounts) {
+ if (lazy_refcounts) {
+ if (new_version < 3) {
+ error_setg(errp, "Lazy refcounts only supported with "
+ "compatibility level 1.1 and above (use compat=1.1 "
+ "or greater)");
+ return -EINVAL;
+ }
+ s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS;
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS;
+ error_setg_errno(errp, -ret, "Failed to update the image header");
+ return ret;
+ }
+ s->use_lazy_refcounts = true;
+ } else {
+ /* make image clean first */
+ ret = qcow2_mark_clean(bs);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to make the image clean");
+ return ret;
+ }
+ /* now disallow lazy refcounts */
+ s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS;
+ ret = qcow2_update_header(bs);
+ if (ret < 0) {
+ s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS;
+ error_setg_errno(errp, -ret, "Failed to update the image header");
+ return ret;
+ }
+ s->use_lazy_refcounts = false;
+ }
+ }
+
+ if (new_size) {
+ BlockBackend *blk = blk_new_with_bs(bs, BLK_PERM_RESIZE, BLK_PERM_ALL,
+ errp);
+ if (!blk) {
+ return -EPERM;
+ }
+
+ /*
+ * Amending image options should ensure that the image has
+ * exactly the given new values, so pass exact=true here.
+ */
+ ret = blk_truncate(blk, new_size, true, PREALLOC_MODE_OFF, 0, errp);
+ blk_unref(blk);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ /* Downgrade last (so unsupported features can be removed before) */
+ if (new_version < old_version) {
+ helper_cb_info.current_operation = QCOW2_DOWNGRADING;
+ ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb,
+ &helper_cb_info, errp);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int coroutine_fn qcow2_co_amend(BlockDriverState *bs,
+ BlockdevAmendOptions *opts,
+ bool force,
+ Error **errp)
+{
+ BlockdevAmendOptionsQcow2 *qopts = &opts->u.qcow2;
+ BDRVQcow2State *s = bs->opaque;
+ int ret = 0;
+
+ if (qopts->has_encrypt) {
+ if (!s->crypto) {
+ error_setg(errp, "image is not encrypted, can't amend");
+ return -EOPNOTSUPP;
+ }
+
+ if (qopts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_LUKS) {
+ error_setg(errp,
+ "Amend can't be used to change the qcow2 encryption format");
+ return -EOPNOTSUPP;
+ }
+
+ if (s->crypt_method_header != QCOW_CRYPT_LUKS) {
+ error_setg(errp,
+ "Only LUKS encryption options can be amended for qcow2 with blockdev-amend");
+ return -EOPNOTSUPP;
+ }
+
+ ret = qcrypto_block_amend_options(s->crypto,
+ qcow2_crypto_hdr_read_func,
+ qcow2_crypto_hdr_write_func,
+ bs,
+ qopts->encrypt,
+ force,
+ errp);
+ }
+ return ret;
+}
+
+/*
+ * If offset or size are negative, respectively, they will not be included in
+ * the BLOCK_IMAGE_CORRUPTED event emitted.
+ * fatal will be ignored for read-only BDS; corruptions found there will always
+ * be considered non-fatal.
+ */
+void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset,
+ int64_t size, const char *message_format, ...)
+{
+ BDRVQcow2State *s = bs->opaque;
+ const char *node_name;
+ char *message;
+ va_list ap;
+
+ fatal = fatal && bdrv_is_writable(bs);
+
+ if (s->signaled_corruption &&
+ (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT)))
+ {
+ return;
+ }
+
+ va_start(ap, message_format);
+ message = g_strdup_vprintf(message_format, ap);
+ va_end(ap);
+
+ if (fatal) {
+ fprintf(stderr, "qcow2: Marking image as corrupt: %s; further "
+ "corruption events will be suppressed\n", message);
+ } else {
+ fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal "
+ "corruption events will be suppressed\n", message);
+ }
+
+ node_name = bdrv_get_node_name(bs);
+ qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs),
+ *node_name != '\0', node_name,
+ message, offset >= 0, offset,
+ size >= 0, size,
+ fatal);
+ g_free(message);
+
+ if (fatal) {
+ qcow2_mark_corrupt(bs);
+ bs->drv = NULL; /* make BDS unusable */
+ }
+
+ s->signaled_corruption = true;
+}
+
+#define QCOW_COMMON_OPTIONS \
+ { \
+ .name = BLOCK_OPT_SIZE, \
+ .type = QEMU_OPT_SIZE, \
+ .help = "Virtual disk size" \
+ }, \
+ { \
+ .name = BLOCK_OPT_COMPAT_LEVEL, \
+ .type = QEMU_OPT_STRING, \
+ .help = "Compatibility level (v2 [0.10] or v3 [1.1])" \
+ }, \
+ { \
+ .name = BLOCK_OPT_BACKING_FILE, \
+ .type = QEMU_OPT_STRING, \
+ .help = "File name of a base image" \
+ }, \
+ { \
+ .name = BLOCK_OPT_BACKING_FMT, \
+ .type = QEMU_OPT_STRING, \
+ .help = "Image format of the base image" \
+ }, \
+ { \
+ .name = BLOCK_OPT_DATA_FILE, \
+ .type = QEMU_OPT_STRING, \
+ .help = "File name of an external data file" \
+ }, \
+ { \
+ .name = BLOCK_OPT_DATA_FILE_RAW, \
+ .type = QEMU_OPT_BOOL, \
+ .help = "The external data file must stay valid " \
+ "as a raw image" \
+ }, \
+ { \
+ .name = BLOCK_OPT_LAZY_REFCOUNTS, \
+ .type = QEMU_OPT_BOOL, \
+ .help = "Postpone refcount updates", \
+ .def_value_str = "off" \
+ }, \
+ { \
+ .name = BLOCK_OPT_REFCOUNT_BITS, \
+ .type = QEMU_OPT_NUMBER, \
+ .help = "Width of a reference count entry in bits", \
+ .def_value_str = "16" \
+ }
+
+static QemuOptsList qcow2_create_opts = {
+ .name = "qcow2-create-opts",
+ .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head),
+ .desc = {
+ { \
+ .name = BLOCK_OPT_ENCRYPT, \
+ .type = QEMU_OPT_BOOL, \
+ .help = "Encrypt the image with format 'aes'. (Deprecated " \
+ "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)", \
+ }, \
+ { \
+ .name = BLOCK_OPT_ENCRYPT_FORMAT, \
+ .type = QEMU_OPT_STRING, \
+ .help = "Encrypt the image, format choices: 'aes', 'luks'", \
+ }, \
+ BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", \
+ "ID of secret providing qcow AES key or LUKS passphrase"), \
+ BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_ALG("encrypt."), \
+ BLOCK_CRYPTO_OPT_DEF_LUKS_CIPHER_MODE("encrypt."), \
+ BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_ALG("encrypt."), \
+ BLOCK_CRYPTO_OPT_DEF_LUKS_IVGEN_HASH_ALG("encrypt."), \
+ BLOCK_CRYPTO_OPT_DEF_LUKS_HASH_ALG("encrypt."), \
+ BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."), \
+ { \
+ .name = BLOCK_OPT_CLUSTER_SIZE, \
+ .type = QEMU_OPT_SIZE, \
+ .help = "qcow2 cluster size", \
+ .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) \
+ }, \
+ { \
+ .name = BLOCK_OPT_EXTL2, \
+ .type = QEMU_OPT_BOOL, \
+ .help = "Extended L2 tables", \
+ .def_value_str = "off" \
+ }, \
+ { \
+ .name = BLOCK_OPT_PREALLOC, \
+ .type = QEMU_OPT_STRING, \
+ .help = "Preallocation mode (allowed values: off, " \
+ "metadata, falloc, full)" \
+ }, \
+ { \
+ .name = BLOCK_OPT_COMPRESSION_TYPE, \
+ .type = QEMU_OPT_STRING, \
+ .help = "Compression method used for image cluster " \
+ "compression", \
+ .def_value_str = "zlib" \
+ },
+ QCOW_COMMON_OPTIONS,
+ { /* end of list */ }
+ }
+};
+
+static QemuOptsList qcow2_amend_opts = {
+ .name = "qcow2-amend-opts",
+ .head = QTAILQ_HEAD_INITIALIZER(qcow2_amend_opts.head),
+ .desc = {
+ BLOCK_CRYPTO_OPT_DEF_LUKS_STATE("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_KEYSLOT("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_OLD_SECRET("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_NEW_SECRET("encrypt."),
+ BLOCK_CRYPTO_OPT_DEF_LUKS_ITER_TIME("encrypt."),
+ QCOW_COMMON_OPTIONS,
+ { /* end of list */ }
+ }
+};
+
+static const char *const qcow2_strong_runtime_opts[] = {
+ "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET,
+
+ NULL
+};
+
+BlockDriver bdrv_qcow2 = {
+ .format_name = "qcow2",
+ .instance_size = sizeof(BDRVQcow2State),
+ .bdrv_probe = qcow2_probe,
+ .bdrv_open = qcow2_open,
+ .bdrv_close = qcow2_close,
+ .bdrv_reopen_prepare = qcow2_reopen_prepare,
+ .bdrv_reopen_commit = qcow2_reopen_commit,
+ .bdrv_reopen_commit_post = qcow2_reopen_commit_post,
+ .bdrv_reopen_abort = qcow2_reopen_abort,
+ .bdrv_join_options = qcow2_join_options,
+ .bdrv_child_perm = bdrv_default_perms,
+ .bdrv_co_create_opts = qcow2_co_create_opts,
+ .bdrv_co_create = qcow2_co_create,
+ .bdrv_has_zero_init = qcow2_has_zero_init,
+ .bdrv_co_block_status = qcow2_co_block_status,
+
+ .bdrv_co_preadv_part = qcow2_co_preadv_part,
+ .bdrv_co_pwritev_part = qcow2_co_pwritev_part,
+ .bdrv_co_flush_to_os = qcow2_co_flush_to_os,
+
+ .bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes,
+ .bdrv_co_pdiscard = qcow2_co_pdiscard,
+ .bdrv_co_copy_range_from = qcow2_co_copy_range_from,
+ .bdrv_co_copy_range_to = qcow2_co_copy_range_to,
+ .bdrv_co_truncate = qcow2_co_truncate,
+ .bdrv_co_pwritev_compressed_part = qcow2_co_pwritev_compressed_part,
+ .bdrv_make_empty = qcow2_make_empty,
+
+ .bdrv_snapshot_create = qcow2_snapshot_create,
+ .bdrv_snapshot_goto = qcow2_snapshot_goto,
+ .bdrv_snapshot_delete = qcow2_snapshot_delete,
+ .bdrv_snapshot_list = qcow2_snapshot_list,
+ .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
+ .bdrv_measure = qcow2_measure,
+ .bdrv_get_info = qcow2_get_info,
+ .bdrv_get_specific_info = qcow2_get_specific_info,
+
+ .bdrv_save_vmstate = qcow2_save_vmstate,
+ .bdrv_load_vmstate = qcow2_load_vmstate,
+
+ .is_format = true,
+ .supports_backing = true,
+ .bdrv_change_backing_file = qcow2_change_backing_file,
+
+ .bdrv_refresh_limits = qcow2_refresh_limits,
+ .bdrv_co_invalidate_cache = qcow2_co_invalidate_cache,
+ .bdrv_inactivate = qcow2_inactivate,
+
+ .create_opts = &qcow2_create_opts,
+ .amend_opts = &qcow2_amend_opts,
+ .strong_runtime_opts = qcow2_strong_runtime_opts,
+ .mutable_opts = mutable_opts,
+ .bdrv_co_check = qcow2_co_check,
+ .bdrv_amend_options = qcow2_amend_options,
+ .bdrv_co_amend = qcow2_co_amend,
+
+ .bdrv_detach_aio_context = qcow2_detach_aio_context,
+ .bdrv_attach_aio_context = qcow2_attach_aio_context,
+
+ .bdrv_supports_persistent_dirty_bitmap =
+ qcow2_supports_persistent_dirty_bitmap,
+ .bdrv_co_can_store_new_dirty_bitmap = qcow2_co_can_store_new_dirty_bitmap,
+ .bdrv_co_remove_persistent_dirty_bitmap =
+ qcow2_co_remove_persistent_dirty_bitmap,
+};
+
+static void bdrv_qcow2_init(void)
+{
+ bdrv_register(&bdrv_qcow2);
+}
+
+block_init(bdrv_qcow2_init);