| /* |
| * 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/block_int.h" |
| #include "sysemu/block-backend.h" |
| #include "qemu/module.h" |
| #include <zlib.h> |
| #include "block/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/opts-visitor.h" |
| #include "block/crypto.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 |
| |
| 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 remaining space in cluster so it has predictable |
| * content in case of future spec changes */ |
| clusterlen = size_to_clusters(s, headerlen) * s->cluster_size; |
| assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen) == 0); |
| ret = bdrv_pwrite_zeroes(bs->file, |
| ret + headerlen, |
| clusterlen - headerlen, 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; |
| } |
| |
| |
| /* |
| * 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; |
| } |
| be32_to_cpus(&ext.magic); |
| be32_to_cpus(&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; |
| } |
| be64_to_cpus(&s->crypto_header.offset); |
| be64_to_cpus(&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, 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; |
| } |
| |
| be32_to_cpus(&bitmaps_ext.nb_bitmaps); |
| be64_to_cpus(&bitmaps_ext.bitmap_directory_size); |
| be64_to_cpus(&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 (bitmaps_ext.bitmap_directory_offset & (s->cluster_size - 1)) { |
| 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; |
| |
| 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) |
| { |
| char *features = g_strdup(""); |
| char *old; |
| |
| while (table && table->name[0] != '\0') { |
| if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { |
| if (mask & (1ULL << table->bit)) { |
| old = features; |
| features = g_strdup_printf("%s%s%.46s", old, *old ? ", " : "", |
| table->name); |
| g_free(old); |
| mask &= ~(1ULL << table->bit); |
| } |
| } |
| table++; |
| } |
| |
| if (mask) { |
| old = features; |
| features = g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64, |
| old, *old ? ", " : "", mask); |
| g_free(old); |
| } |
| |
| error_setg(errp, "Unsupported qcow2 feature(s): %s", features); |
| g_free(features); |
| } |
| |
| /* |
| * 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 int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result, |
| BdrvCheckMode fix) |
| { |
| int ret = qcow2_check_refcounts(bs, result, fix); |
| 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 validate_table_offset(BlockDriverState *bs, uint64_t offset, |
| uint64_t entries, size_t entry_len) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| uint64_t size; |
| |
| /* 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 (entries > INT64_MAX / entry_len) { |
| return -EINVAL; |
| } |
| |
| size = entries * entry_len; |
| |
| if (INT64_MAX - size < offset) { |
| return -EINVAL; |
| } |
| |
| /* Tables must be cluster aligned */ |
| if (offset_into_cluster(s, offset) != 0) { |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| 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_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, |
| }; |
| |
| 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(context, QEMU_CLOCK_VIRTUAL, |
| SCALE_MS, 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_del(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 void 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; |
| bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; |
| |
| 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); |
| |
| combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); |
| *l2_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, 0); |
| *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); |
| |
| 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 " |
| "the same time"); |
| return; |
| } else if (*l2_cache_size > combined_cache_size) { |
| error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " |
| QCOW2_OPT_CACHE_SIZE); |
| return; |
| } else if (*refcount_cache_size > combined_cache_size) { |
| error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed " |
| QCOW2_OPT_CACHE_SIZE); |
| return; |
| } |
| |
| 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 { |
| *refcount_cache_size = combined_cache_size |
| / (DEFAULT_L2_REFCOUNT_SIZE_RATIO + 1); |
| *l2_cache_size = combined_cache_size - *refcount_cache_size; |
| } |
| } else { |
| if (!l2_cache_size_set && !refcount_cache_size_set) { |
| *l2_cache_size = MAX(DEFAULT_L2_CACHE_BYTE_SIZE, |
| (uint64_t)DEFAULT_L2_CACHE_CLUSTERS |
| * s->cluster_size); |
| *refcount_cache_size = *l2_cache_size |
| / DEFAULT_L2_REFCOUNT_SIZE_RATIO; |
| } else if (!l2_cache_size_set) { |
| *l2_cache_size = *refcount_cache_size |
| * DEFAULT_L2_REFCOUNT_SIZE_RATIO; |
| } else if (!refcount_cache_size_set) { |
| *refcount_cache_size = *l2_cache_size |
| / DEFAULT_L2_REFCOUNT_SIZE_RATIO; |
| } |
| } |
| |
| 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; |
| } |
| } |
| |
| 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; |
| Error *local_err = 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); |
| qemu_opts_absorb_qdict(opts, options, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| /* get L2 table/refcount block cache size from command line options */ |
| read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size, |
| &refcount_cache_size, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| 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 / sizeof(uint64_t); |
| 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, |
| s->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_del(encryptopts, "format"); |
| r->crypto_opts = block_crypto_open_opts_init( |
| Q_CRYPTO_BLOCK_FORMAT_QCOW, encryptopts, errp); |
| 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_del(encryptopts, "format"); |
| r->crypto_opts = block_crypto_open_opts_init( |
| Q_CRYPTO_BLOCK_FORMAT_LUKS, encryptopts, errp); |
| break; |
| |
| default: |
| error_setg(errp, "Unsupported encryption method %d", |
| s->crypt_method_header); |
| break; |
| } |
| if (s->crypt_method_header != QCOW_CRYPT_NONE && !r->crypto_opts) { |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| ret = 0; |
| fail: |
| QDECREF(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 qcow2_do_open(BlockDriverState *bs, QDict *options, int flags, |
| Error **errp) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| unsigned int len, i; |
| int ret = 0; |
| QCowHeader header; |
| Error *local_err = NULL; |
| 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; |
| } |
| be32_to_cpus(&header.magic); |
| be32_to_cpus(&header.version); |
| be64_to_cpus(&header.backing_file_offset); |
| be32_to_cpus(&header.backing_file_size); |
| be64_to_cpus(&header.size); |
| be32_to_cpus(&header.cluster_bits); |
| be32_to_cpus(&header.crypt_method); |
| be64_to_cpus(&header.l1_table_offset); |
| be32_to_cpus(&header.l1_size); |
| be64_to_cpus(&header.refcount_table_offset); |
| be32_to_cpus(&header.refcount_table_clusters); |
| be64_to_cpus(&header.snapshots_offset); |
| be32_to_cpus(&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; |
| s->cluster_sectors = 1 << (s->cluster_bits - BDRV_SECTOR_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 { |
| be64_to_cpus(&header.incompatible_features); |
| be64_to_cpus(&header.compatible_features); |
| be64_to_cpus(&header.autoclear_features); |
| be32_to_cpus(&header.refcount_order); |
| be32_to_cpus(&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; |
| |
| 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; |
| } |
| } |
| |
| /* 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 - 3; /* L2 is always one cluster */ |
| 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 / 512; |
| 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 > qcow2_max_refcount_clusters(s)) { |
| error_setg(errp, "Reference count table too large"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| 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 = validate_table_offset(bs, s->refcount_table_offset, |
| s->refcount_table_size, sizeof(uint64_t)); |
| if (ret < 0) { |
| error_setg(errp, "Invalid reference count table offset"); |
| goto fail; |
| } |
| |
| /* Snapshot table offset/length */ |
| if (header.nb_snapshots > QCOW_MAX_SNAPSHOTS) { |
| error_setg(errp, "Too many snapshots"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| ret = validate_table_offset(bs, header.snapshots_offset, |
| header.nb_snapshots, |
| sizeof(QCowSnapshotHeader)); |
| if (ret < 0) { |
| error_setg(errp, "Invalid snapshot table offset"); |
| goto fail; |
| } |
| |
| /* read the level 1 table */ |
| if (header.l1_size > QCOW_MAX_L1_SIZE / sizeof(uint64_t)) { |
| error_setg(errp, "Active L1 table too large"); |
| ret = -EFBIG; |
| goto fail; |
| } |
| s->l1_size = header.l1_size; |
| |
| 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; |
| } |
| |
| ret = validate_table_offset(bs, header.l1_table_offset, |
| header.l1_size, sizeof(uint64_t)); |
| if (ret < 0) { |
| error_setg(errp, "Invalid L1 table offset"); |
| goto fail; |
| } |
| s->l1_table_offset = header.l1_table_offset; |
| |
| |
| if (s->l1_size > 0) { |
| s->l1_table = qemu_try_blockalign(bs->file->bs, |
| ROUND_UP(s->l1_size * sizeof(uint64_t), 512)); |
| 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 * sizeof(uint64_t)); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not read L1 table"); |
| goto fail; |
| } |
| for(i = 0;i < s->l1_size; i++) { |
| be64_to_cpus(&s->l1_table[i]); |
| } |
| } |
| |
| /* Parse driver-specific options */ |
| ret = qcow2_update_options(bs, options, flags, errp); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| s->cluster_cache_offset = -1; |
| 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, &local_err)) { |
| error_propagate(errp, local_err); |
| 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, 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->backing_file, len); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not read backing file name"); |
| goto fail; |
| } |
| bs->backing_file[len] = '\0'; |
| s->image_backing_file = g_strdup(bs->backing_file); |
| } |
| |
| /* Internal snapshots */ |
| s->snapshots_offset = header.snapshots_offset; |
| s->nb_snapshots = header.nb_snapshots; |
| |
| ret = qcow2_read_snapshots(bs); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not read snapshots"); |
| goto fail; |
| } |
| |
| /* Clear unknown autoclear feature bits */ |
| update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; |
| update_header = |
| update_header && !bs->read_only && !(flags & BDRV_O_INACTIVE); |
| if (update_header) { |
| s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; |
| } |
| |
| if (qcow2_load_dirty_bitmaps(bs, &local_err)) { |
| update_header = false; |
| } |
| if (local_err != NULL) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| if (update_header) { |
| ret = qcow2_update_header(bs); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not update qcow2 header"); |
| goto fail; |
| } |
| } |
| |
| /* Initialise locks */ |
| qemu_co_mutex_init(&s->lock); |
| bs->supported_zero_flags = header.version >= 3 ? BDRV_REQ_MAY_UNMAP : 0; |
| |
| /* Repair image if dirty */ |
| if (!(flags & (BDRV_O_CHECK | BDRV_O_INACTIVE)) && !bs->read_only && |
| (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { |
| BdrvCheckResult result = {0}; |
| |
| ret = qcow2_check(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 |
| return ret; |
| |
| fail: |
| 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; |
| } |
| |
| static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, |
| Error **errp) |
| { |
| bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, |
| false, errp); |
| if (!bs->file) { |
| return -EINVAL; |
| } |
| |
| return qcow2_do_open(bs, options, flags, errp); |
| } |
| |
| 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 = BDRV_SECTOR_SIZE; |
| } |
| bs->bl.pwrite_zeroes_alignment = s->cluster_size; |
| bs->bl.pdiscard_alignment = s->cluster_size; |
| } |
| |
| static int qcow2_reopen_prepare(BDRVReopenState *state, |
| BlockReopenQueue *queue, Error **errp) |
| { |
| 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; |
| } |
| } |
| |
| return 0; |
| |
| fail: |
| qcow2_update_options_abort(state->bs, r); |
| g_free(r); |
| return ret; |
| } |
| |
| static void qcow2_reopen_commit(BDRVReopenState *state) |
| { |
| qcow2_update_options_commit(state->bs, state->opaque); |
| g_free(state->opaque); |
| } |
| |
| static void qcow2_reopen_abort(BDRVReopenState *state) |
| { |
| 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 cluster_offset; |
| int index_in_cluster, ret; |
| unsigned int bytes; |
| int status = 0; |
| |
| bytes = MIN(INT_MAX, count); |
| qemu_co_mutex_lock(&s->lock); |
| ret = qcow2_get_cluster_offset(bs, offset, &bytes, &cluster_offset); |
| qemu_co_mutex_unlock(&s->lock); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| *pnum = bytes; |
| |
| if (cluster_offset != 0 && ret != QCOW2_CLUSTER_COMPRESSED && |
| !s->crypto) { |
| index_in_cluster = offset & (s->cluster_size - 1); |
| *map = cluster_offset | index_in_cluster; |
| *file = bs->file->bs; |
| status |= BDRV_BLOCK_OFFSET_VALID; |
| } |
| if (ret == QCOW2_CLUSTER_ZERO_PLAIN || ret == QCOW2_CLUSTER_ZERO_ALLOC) { |
| status |= BDRV_BLOCK_ZERO; |
| } else if (ret != QCOW2_CLUSTER_UNALLOCATED) { |
| status |= BDRV_BLOCK_DATA; |
| } |
| return status; |
| } |
| |
| static coroutine_fn int qcow2_co_preadv(BlockDriverState *bs, uint64_t offset, |
| uint64_t bytes, QEMUIOVector *qiov, |
| int flags) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| int offset_in_cluster; |
| int ret; |
| unsigned int cur_bytes; /* number of bytes in current iteration */ |
| uint64_t cluster_offset = 0; |
| uint64_t bytes_done = 0; |
| QEMUIOVector hd_qiov; |
| uint8_t *cluster_data = NULL; |
| |
| qemu_iovec_init(&hd_qiov, qiov->niov); |
| |
| qemu_co_mutex_lock(&s->lock); |
| |
| while (bytes != 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); |
| } |
| |
| ret = qcow2_get_cluster_offset(bs, offset, &cur_bytes, &cluster_offset); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| offset_in_cluster = offset_into_cluster(s, offset); |
| |
| qemu_iovec_reset(&hd_qiov); |
| qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_bytes); |
| |
| switch (ret) { |
| case QCOW2_CLUSTER_UNALLOCATED: |
| |
| if (bs->backing) { |
| BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); |
| qemu_co_mutex_unlock(&s->lock); |
| ret = bdrv_co_preadv(bs->backing, offset, cur_bytes, |
| &hd_qiov, 0); |
| qemu_co_mutex_lock(&s->lock); |
| if (ret < 0) { |
| goto fail; |
| } |
| } else { |
| /* Note: in this case, no need to wait */ |
| qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes); |
| } |
| break; |
| |
| case QCOW2_CLUSTER_ZERO_PLAIN: |
| case QCOW2_CLUSTER_ZERO_ALLOC: |
| qemu_iovec_memset(&hd_qiov, 0, 0, cur_bytes); |
| break; |
| |
| case QCOW2_CLUSTER_COMPRESSED: |
| /* add AIO support for compressed blocks ? */ |
| ret = qcow2_decompress_cluster(bs, cluster_offset); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| qemu_iovec_from_buf(&hd_qiov, 0, |
| s->cluster_cache + offset_in_cluster, |
| cur_bytes); |
| break; |
| |
| case QCOW2_CLUSTER_NORMAL: |
| if ((cluster_offset & 511) != 0) { |
| ret = -EIO; |
| goto fail; |
| } |
| |
| if (bs->encrypted) { |
| assert(s->crypto); |
| |
| /* |
| * For encrypted images, read everything into a temporary |
| * contiguous buffer on which the AES functions can work. |
| */ |
| if (!cluster_data) { |
| cluster_data = |
| qemu_try_blockalign(bs->file->bs, |
| QCOW_MAX_CRYPT_CLUSTERS |
| * s->cluster_size); |
| if (cluster_data == NULL) { |
| ret = -ENOMEM; |
| goto fail; |
| } |
| } |
| |
| assert(cur_bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
| qemu_iovec_reset(&hd_qiov); |
| qemu_iovec_add(&hd_qiov, cluster_data, cur_bytes); |
| } |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
| qemu_co_mutex_unlock(&s->lock); |
| ret = bdrv_co_preadv(bs->file, |
| cluster_offset + offset_in_cluster, |
| cur_bytes, &hd_qiov, 0); |
| qemu_co_mutex_lock(&s->lock); |
| if (ret < 0) { |
| goto fail; |
| } |
| if (bs->encrypted) { |
| assert(s->crypto); |
| assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); |
| assert((cur_bytes & (BDRV_SECTOR_SIZE - 1)) == 0); |
| if (qcrypto_block_decrypt(s->crypto, |
| (s->crypt_physical_offset ? |
| cluster_offset + offset_in_cluster : |
| offset), |
| cluster_data, |
| cur_bytes, |
| NULL) < 0) { |
| ret = -EIO; |
| goto fail; |
| } |
| qemu_iovec_from_buf(qiov, bytes_done, cluster_data, cur_bytes); |
| } |
| break; |
| |
| default: |
| g_assert_not_reached(); |
| ret = -EIO; |
| goto fail; |
| } |
| |
| bytes -= cur_bytes; |
| offset += cur_bytes; |
| bytes_done += cur_bytes; |
| } |
| ret = 0; |
| |
| fail: |
| qemu_co_mutex_unlock(&s->lock); |
| |
| qemu_iovec_destroy(&hd_qiov); |
| qemu_vfree(cluster_data); |
| |
| 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 *hd_qiov, 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; |
| } |
| |
| /* The data (middle) region must be immediately after the |
| * start region */ |
| if (l2meta_cow_start(m) + m->cow_start.nb_bytes != offset) { |
| continue; |
| } |
| |
| /* The end region must be immediately after the data (middle) |
| * region */ |
| if (m->offset + m->cow_end.offset != offset + bytes) { |
| continue; |
| } |
| |
| /* Make sure that adding both COW regions to the QEMUIOVector |
| * does not exceed IOV_MAX */ |
| if (hd_qiov->niov > IOV_MAX - 2) { |
| continue; |
| } |
| |
| m->data_qiov = hd_qiov; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static coroutine_fn int qcow2_co_pwritev(BlockDriverState *bs, uint64_t offset, |
| uint64_t bytes, QEMUIOVector *qiov, |
| int flags) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| int offset_in_cluster; |
| int ret; |
| unsigned int cur_bytes; /* number of sectors in current iteration */ |
| uint64_t cluster_offset; |
| QEMUIOVector hd_qiov; |
| uint64_t bytes_done = 0; |
| uint8_t *cluster_data = NULL; |
| QCowL2Meta *l2meta = NULL; |
| |
| trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes); |
| |
| qemu_iovec_init(&hd_qiov, qiov->niov); |
| |
| s->cluster_cache_offset = -1; /* disable compressed cache */ |
| |
| qemu_co_mutex_lock(&s->lock); |
| |
| while (bytes != 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); |
| } |
| |
| ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes, |
| &cluster_offset, &l2meta); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| assert((cluster_offset & 511) == 0); |
| |
| qemu_iovec_reset(&hd_qiov); |
| qemu_iovec_concat(&hd_qiov, qiov, bytes_done, cur_bytes); |
| |
| if (bs->encrypted) { |
| assert(s->crypto); |
| if (!cluster_data) { |
| cluster_data = qemu_try_blockalign(bs->file->bs, |
| QCOW_MAX_CRYPT_CLUSTERS |
| * s->cluster_size); |
| if (cluster_data == NULL) { |
| ret = -ENOMEM; |
| goto fail; |
| } |
| } |
| |
| assert(hd_qiov.size <= |
| QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
| qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size); |
| |
| if (qcrypto_block_encrypt(s->crypto, |
| (s->crypt_physical_offset ? |
| cluster_offset + offset_in_cluster : |
| offset), |
| cluster_data, |
| cur_bytes, NULL) < 0) { |
| ret = -EIO; |
| goto fail; |
| } |
| |
| qemu_iovec_reset(&hd_qiov); |
| qemu_iovec_add(&hd_qiov, cluster_data, cur_bytes); |
| } |
| |
| ret = qcow2_pre_write_overlap_check(bs, 0, |
| cluster_offset + offset_in_cluster, cur_bytes); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| /* 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, cur_bytes, &hd_qiov, l2meta)) { |
| qemu_co_mutex_unlock(&s->lock); |
| BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); |
| trace_qcow2_writev_data(qemu_coroutine_self(), |
| cluster_offset + offset_in_cluster); |
| ret = bdrv_co_pwritev(bs->file, |
| cluster_offset + offset_in_cluster, |
| cur_bytes, &hd_qiov, 0); |
| qemu_co_mutex_lock(&s->lock); |
| if (ret < 0) { |
| goto fail; |
| } |
| } |
| |
| while (l2meta != NULL) { |
| QCowL2Meta *next; |
| |
| ret = qcow2_alloc_cluster_link_l2(bs, l2meta); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| /* Take the request off the list of running requests */ |
| if (l2meta->nb_clusters != 0) { |
| QLIST_REMOVE(l2meta, next_in_flight); |
| } |
| |
| qemu_co_queue_restart_all(&l2meta->dependent_requests); |
| |
| next = l2meta->next; |
| g_free(l2meta); |
| l2meta = next; |
| } |
| |
| bytes -= cur_bytes; |
| offset += cur_bytes; |
| bytes_done += cur_bytes; |
| trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes); |
| } |
| ret = 0; |
| |
| fail: |
| while (l2meta != NULL) { |
| QCowL2Meta *next; |
| |
| if (l2meta->nb_clusters != 0) { |
| QLIST_REMOVE(l2meta, next_in_flight); |
| } |
| qemu_co_queue_restart_all(&l2meta->dependent_requests); |
| |
| next = l2meta->next; |
| g_free(l2meta); |
| l2meta = next; |
| } |
| |
| qemu_co_mutex_unlock(&s->lock); |
| |
| qemu_iovec_destroy(&hd_qiov); |
| qemu_vfree(cluster_data); |
| 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, &local_err); |
| if (local_err != NULL) { |
| result = -EINVAL; |
| error_report_err(local_err); |
| error_report("Persistent bitmaps are lost for 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; |
| |
| g_free(s->unknown_header_fields); |
| cleanup_unknown_header_ext(bs); |
| |
| g_free(s->image_backing_file); |
| g_free(s->image_backing_format); |
| |
| g_free(s->cluster_cache); |
| qemu_vfree(s->cluster_data); |
| qcow2_refcount_close(bs); |
| qcow2_free_snapshots(bs); |
| } |
| |
| static void qcow2_invalidate_cache(BlockDriverState *bs, Error **errp) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| int flags = s->flags; |
| QCryptoBlock *crypto = NULL; |
| QDict *options; |
| Error *local_err = NULL; |
| 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; |
| ret = qcow2_do_open(bs, options, flags, &local_err); |
| QDECREF(options); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| error_prepend(errp, "Could not reopen qcow2 layer: "); |
| bs->drv = NULL; |
| return; |
| } else if (ret < 0) { |
| error_setg_errno(errp, -ret, "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); |
| |
| *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), |
| }; |
| |
| /* 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; |
| } |
| |
| /* Full disk encryption header pointer extension */ |
| if (s->crypto_header.offset != 0) { |
| cpu_to_be64s(&s->crypto_header.offset); |
| cpu_to_be64s(&s->crypto_header.length); |
| ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER, |
| &s->crypto_header, sizeof(s->crypto_header), |
| buflen); |
| be64_to_cpus(&s->crypto_header.offset); |
| be64_to_cpus(&s->crypto_header.length); |
| if (ret < 0) { |
| goto fail; |
| } |
| buf += ret; |
| buflen -= ret; |
| } |
| |
| /* Feature table */ |
| if (s->qcow_version >= 3) { |
| 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_COMPATIBLE, |
| .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, |
| .name = "lazy refcounts", |
| }, |
| }; |
| |
| 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; |
| |
| if (backing_file && strlen(backing_file) > 1023) { |
| return -EINVAL; |
| } |
| |
| 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_crypt_method_from_format(const char *encryptfmt) |
| { |
| if (g_str_equal(encryptfmt, "luks")) { |
| return QCOW_CRYPT_LUKS; |
| } else if (g_str_equal(encryptfmt, "aes")) { |
| return QCOW_CRYPT_AES; |
| } else { |
| return -EINVAL; |
| } |
| } |
| |
| static int qcow2_set_up_encryption(BlockDriverState *bs, const char *encryptfmt, |
| QemuOpts *opts, Error **errp) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| QCryptoBlockCreateOptions *cryptoopts = NULL; |
| QCryptoBlock *crypto = NULL; |
| int ret = -EINVAL; |
| QDict *options, *encryptopts; |
| int fmt; |
| |
| options = qemu_opts_to_qdict(opts, NULL); |
| qdict_extract_subqdict(options, &encryptopts, "encrypt."); |
| QDECREF(options); |
| |
| fmt = qcow2_crypt_method_from_format(encryptfmt); |
| |
| switch (fmt) { |
| case QCOW_CRYPT_LUKS: |
| cryptoopts = block_crypto_create_opts_init( |
| Q_CRYPTO_BLOCK_FORMAT_LUKS, encryptopts, errp); |
| break; |
| case QCOW_CRYPT_AES: |
| cryptoopts = block_crypto_create_opts_init( |
| Q_CRYPTO_BLOCK_FORMAT_QCOW, encryptopts, errp); |
| break; |
| default: |
| error_setg(errp, "Unknown encryption format '%s'", encryptfmt); |
| break; |
| } |
| if (!cryptoopts) { |
| ret = -EINVAL; |
| goto out; |
| } |
| 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) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| ret = qcow2_update_header(bs); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not write encryption header"); |
| goto out; |
| } |
| |
| out: |
| QDECREF(encryptopts); |
| qcrypto_block_free(crypto); |
| qapi_free_QCryptoBlockCreateOptions(cryptoopts); |
| return ret; |
| } |
| |
| |
| typedef struct PreallocCo { |
| BlockDriverState *bs; |
| uint64_t offset; |
| uint64_t new_length; |
| |
| int ret; |
| } PreallocCo; |
| |
| /** |
| * 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 void coroutine_fn preallocate_co(void *opaque) |
| { |
| PreallocCo *params = opaque; |
| BlockDriverState *bs = params->bs; |
| uint64_t offset = params->offset; |
| uint64_t new_length = params->new_length; |
| BDRVQcow2State *s = bs->opaque; |
| uint64_t bytes; |
| uint64_t host_offset = 0; |
| unsigned int cur_bytes; |
| int ret; |
| QCowL2Meta *meta; |
| |
| qemu_co_mutex_lock(&s->lock); |
| |
| assert(offset <= new_length); |
| bytes = new_length - offset; |
| |
| while (bytes) { |
| cur_bytes = MIN(bytes, INT_MAX); |
| ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes, |
| &host_offset, &meta); |
| if (ret < 0) { |
| goto done; |
| } |
| |
| while (meta) { |
| QCowL2Meta *next = meta->next; |
| |
| ret = qcow2_alloc_cluster_link_l2(bs, meta); |
| if (ret < 0) { |
| qcow2_free_any_clusters(bs, meta->alloc_offset, |
| meta->nb_clusters, QCOW2_DISCARD_NEVER); |
| goto done; |
| } |
| |
| /* There are no dependent requests, but we need to remove our |
| * request from the list of in-flight requests */ |
| QLIST_REMOVE(meta, next_in_flight); |
| |
| g_free(meta); |
| meta = next; |
| } |
| |
| /* 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. |
| */ |
| if (host_offset != 0) { |
| uint8_t data = 0; |
| ret = bdrv_pwrite(bs->file, (host_offset + cur_bytes) - 1, |
| &data, 1); |
| if (ret < 0) { |
| goto done; |
| } |
| } |
| |
| ret = 0; |
| |
| done: |
| qemu_co_mutex_unlock(&s->lock); |
| params->ret = ret; |
| } |
| |
| static int preallocate(BlockDriverState *bs, |
| uint64_t offset, uint64_t new_length) |
| { |
| PreallocCo params = { |
| .bs = bs, |
| .offset = offset, |
| .new_length = new_length, |
| .ret = -EINPROGRESS, |
| }; |
| |
| if (qemu_in_coroutine()) { |
| preallocate_co(¶ms); |
| } else { |
| Coroutine *co = qemu_coroutine_create(preallocate_co, ¶ms); |
| bdrv_coroutine_enter(bs, co); |
| BDRV_POLL_WHILE(bs, params.ret == -EINPROGRESS); |
| } |
| return params.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 / sizeof(uint64_t); |
| 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 |
| * |
| * 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) |
| { |
| int64_t meta_size = 0; |
| uint64_t nl1e, nl2e; |
| int64_t aligned_total_size = ROUND_UP(total_size, cluster_size); |
| |
| /* header: 1 cluster */ |
| meta_size += cluster_size; |
| |
| /* total size of L2 tables */ |
| nl2e = aligned_total_size / cluster_size; |
| nl2e = ROUND_UP(nl2e, cluster_size / sizeof(uint64_t)); |
| meta_size += nl2e * sizeof(uint64_t); |
| |
| /* total size of L1 tables */ |
| nl1e = nl2e * sizeof(uint64_t) / cluster_size; |
| nl1e = ROUND_UP(nl1e, cluster_size / sizeof(uint64_t)); |
| meta_size += nl1e * sizeof(uint64_t); |
| |
| /* 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 size_t qcow2_opt_get_cluster_size_del(QemuOpts *opts, Error **errp) |
| { |
| size_t cluster_size; |
| int cluster_bits; |
| |
| cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, |
| DEFAULT_CLUSTER_SIZE); |
| 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 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_create2(const char *filename, int64_t total_size, |
| const char *backing_file, const char *backing_format, |
| int flags, size_t cluster_size, PreallocMode prealloc, |
| QemuOpts *opts, int version, int refcount_order, |
| const char *encryptfmt, Error **errp) |
| { |
| 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 seconds 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; |
| QCowHeader *header; |
| uint64_t* refcount_table; |
| Error *local_err = NULL; |
| int ret; |
| |
| if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { |
| int64_t prealloc_size = |
| qcow2_calc_prealloc_size(total_size, cluster_size, refcount_order); |
| qemu_opt_set_number(opts, BLOCK_OPT_SIZE, prealloc_size, &error_abort); |
| qemu_opt_set(opts, BLOCK_OPT_PREALLOC, PreallocMode_str(prealloc), |
| &error_abort); |
| } |
| |
| ret = bdrv_create_file(filename, opts, &local_err); |
| if (ret < 0) { |
| error_propagate(errp, local_err); |
| return ret; |
| } |
| |
| blk = blk_new_open(filename, NULL, NULL, |
| BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, |
| &local_err); |
| if (blk == NULL) { |
| error_propagate(errp, local_err); |
| return -EIO; |
| } |
| |
| 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), |
| .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 (flags & BLOCK_FLAG_LAZY_REFCOUNTS) { |
| header->compatible_features |= |
| cpu_to_be64(QCOW2_COMPAT_LAZY_REFCOUNTS); |
| } |
| |
| 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"); |
| blk = blk_new_open(filename, NULL, options, |
| BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_NO_FLUSH, |
| &local_err); |
| if (blk == NULL) { |
| error_propagate(errp, local_err); |
| 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(); |
| } |
| |
| /* 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, total_size, PREALLOC_MODE_OFF, errp); |
| if (ret < 0) { |
| error_prepend(errp, "Could not resize image: "); |
| goto out; |
| } |
| |
| /* Want a backing file? There you go.*/ |
| if (backing_file) { |
| ret = bdrv_change_backing_file(blk_bs(blk), backing_file, backing_format); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not assign backing file '%s' " |
| "with format '%s'", backing_file, backing_format); |
| goto out; |
| } |
| } |
| |
| /* Want encryption? There you go. */ |
| if (encryptfmt) { |
| ret = qcow2_set_up_encryption(blk_bs(blk), encryptfmt, opts, errp); |
| if (ret < 0) { |
| goto out; |
| } |
| } |
| |
| /* And if we're supposed to preallocate metadata, do that now */ |
| if (prealloc != PREALLOC_MODE_OFF) { |
| ret = preallocate(blk_bs(blk), 0, total_size); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not preallocate metadata"); |
| 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"); |
| blk = blk_new_open(filename, NULL, options, |
| BDRV_O_RDWR | BDRV_O_NO_BACKING | BDRV_O_NO_IO, |
| &local_err); |
| if (blk == NULL) { |
| error_propagate(errp, local_err); |
| ret = -EIO; |
| goto out; |
| } |
| |
| ret = 0; |
| out: |
| if (blk) { |
| blk_unref(blk); |
| } |
| return ret; |
| } |
| |
| static int coroutine_fn qcow2_co_create_opts(const char *filename, QemuOpts *opts, |
| Error **errp) |
| { |
| char *backing_file = NULL; |
| char *backing_fmt = NULL; |
| char *buf = NULL; |
| uint64_t size = 0; |
| int flags = 0; |
| size_t cluster_size = DEFAULT_CLUSTER_SIZE; |
| PreallocMode prealloc; |
| int version; |
| uint64_t refcount_bits; |
| int refcount_order; |
| char *encryptfmt = NULL; |
| Error *local_err = NULL; |
| int ret; |
| |
| /* Read out options */ |
| size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), |
| BDRV_SECTOR_SIZE); |
| backing_file = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FILE); |
| backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT); |
| encryptfmt = qemu_opt_get_del(opts, BLOCK_OPT_ENCRYPT_FORMAT); |
| if (encryptfmt) { |
| if (qemu_opt_get(opts, BLOCK_OPT_ENCRYPT)) { |
| error_setg(errp, "Options " BLOCK_OPT_ENCRYPT " and " |
| BLOCK_OPT_ENCRYPT_FORMAT " are mutually exclusive"); |
| ret = -EINVAL; |
| goto finish; |
| } |
| } else if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) { |
| encryptfmt = g_strdup("aes"); |
| } |
| cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto finish; |
| } |
| buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); |
| prealloc = qapi_enum_parse(&PreallocMode_lookup, buf, |
| PREALLOC_MODE_OFF, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto finish; |
| } |
| |
| version = qcow2_opt_get_version_del(opts, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto finish; |
| } |
| |
| if (qemu_opt_get_bool_del(opts, BLOCK_OPT_LAZY_REFCOUNTS, false)) { |
| flags |= BLOCK_FLAG_LAZY_REFCOUNTS; |
| } |
| |
| if (backing_file && prealloc != PREALLOC_MODE_OFF) { |
| error_setg(errp, "Backing file and preallocation cannot be used at " |
| "the same time"); |
| ret = -EINVAL; |
| goto finish; |
| } |
| |
| if (version < 3 && (flags & BLOCK_FLAG_LAZY_REFCOUNTS)) { |
| error_setg(errp, "Lazy refcounts only supported with compatibility " |
| "level 1.1 and above (use compat=1.1 or greater)"); |
| ret = -EINVAL; |
| goto finish; |
| } |
| |
| refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto finish; |
| } |
| |
| refcount_order = ctz32(refcount_bits); |
| |
| ret = qcow2_co_create2(filename, size, backing_file, backing_fmt, flags, |
| cluster_size, prealloc, opts, version, refcount_order, |
| encryptfmt, &local_err); |
| error_propagate(errp, local_err); |
| |
| finish: |
| g_free(backing_file); |
| g_free(backing_fmt); |
| g_free(encryptfmt); |
| g_free(buf); |
| 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; |
| } |
| res = bdrv_block_status_above(bs, NULL, offset, bytes, &nr, NULL, NULL); |
| return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == bytes; |
| } |
| |
| static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs, |
| int64_t offset, int bytes, BdrvRequestFlags flags) |
| { |
| int ret; |
| BDRVQcow2State *s = bs->opaque; |
| |
| uint32_t head = offset % s->cluster_size; |
| uint32_t tail = (offset + bytes) % s->cluster_size; |
| |
| 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; |
| |
| assert(head + bytes <= s->cluster_size); |
| |
| /* check whether remainder of cluster already reads as zero */ |
| if (!(is_zero(bs, offset - head, head) && |
| is_zero(bs, offset + bytes, |
| tail ? s->cluster_size - tail : 0))) { |
| return -ENOTSUP; |
| } |
| |
| qemu_co_mutex_lock(&s->lock); |
| /* We can have new write after previous check */ |
| offset = QEMU_ALIGN_DOWN(offset, s->cluster_size); |
| bytes = s->cluster_size; |
| nr = s->cluster_size; |
| ret = qcow2_get_cluster_offset(bs, offset, &nr, &off); |
| if (ret != QCOW2_CLUSTER_UNALLOCATED && |
| ret != QCOW2_CLUSTER_ZERO_PLAIN && |
| ret != QCOW2_CLUSTER_ZERO_ALLOC) { |
| qemu_co_mutex_unlock(&s->lock); |
| return -ENOTSUP; |
| } |
| } else { |
| qemu_co_mutex_lock(&s->lock); |
| } |
| |
| trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, bytes); |
| |
| /* Whatever is left can use real zero clusters */ |
| ret = qcow2_cluster_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, int bytes) |
| { |
| int ret; |
| BDRVQcow2State *s = bs->opaque; |
| |
| 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 qcow2_truncate(BlockDriverState *bs, int64_t offset, |
| PreallocMode prealloc, Error **errp) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| uint64_t old_length; |
| int64_t new_l1_size; |
| int ret; |
| |
| 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 (offset & 511) { |
| error_setg(errp, "The new size must be a multiple of 512"); |
| return -EINVAL; |
| } |
| |
| /* cannot proceed if image has snapshots */ |
| if (s->nb_snapshots) { |
| error_setg(errp, "Can't resize an image which has snapshots"); |
| return -ENOTSUP; |
| } |
| |
| /* cannot proceed if image has bitmaps */ |
| if (s->nb_bitmaps) { |
| /* TODO: resize bitmaps in the image */ |
| error_setg(errp, "Can't resize an image which has bitmaps"); |
| return -ENOTSUP; |
| } |
| |
| old_length = bs->total_sectors * 512; |
| 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"); |
| return -EINVAL; |
| } |
| |
| 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"); |
| return ret; |
| } |
| |
| 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"); |
| return ret; |
| } |
| |
| ret = qcow2_shrink_reftable(bs); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, |
| "Failed to discard unused refblocks"); |
| return ret; |
| } |
| |
| 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"); |
| return old_file_size; |
| } |
| 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"); |
| return last_cluster; |
| } |
| if ((last_cluster + 1) * s->cluster_size < old_file_size) { |
| Error *local_err = NULL; |
| |
| bdrv_truncate(bs->file, (last_cluster + 1) * s->cluster_size, |
| PREALLOC_MODE_OFF, &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"); |
| return ret; |
| } |
| } |
| |
| switch (prealloc) { |
| case PREALLOC_MODE_OFF: |
| break; |
| |
| case PREALLOC_MODE_METADATA: |
| ret = preallocate(bs, old_length, offset); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Preallocation failed"); |
| return ret; |
| } |
| 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, new_file_size; |
| uint64_t nb_new_data_clusters, nb_new_l2_tables; |
| |
| 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"); |
| return old_file_size; |
| } |
| old_file_size = ROUND_UP(old_file_size, s->cluster_size); |
| |
| nb_new_data_clusters = DIV_ROUND_UP(offset - old_length, |
| s->cluster_size); |
| |
| /* 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 / sizeof(uint64_t)); |
| /* 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"); |
| return allocation_start; |
| } |
| |
| 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"); |
| return -clusters_allocated; |
| } |
| |
| assert(clusters_allocated == nb_new_data_clusters); |
| |
| /* Allocate the data area */ |
| new_file_size = allocation_start + |
| nb_new_data_clusters * s->cluster_size; |
| ret = bdrv_truncate(bs->file, new_file_size, prealloc, 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); |
| return ret; |
| } |
| |
| /* 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)); |
| QCowL2Meta allocation = { |
| .offset = guest_offset, |
| .alloc_offset = host_offset, |
| .nb_clusters = nb_clusters, |
| }; |
| 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); |
| return ret; |
| } |
| |
| 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 (prealloc != PREALLOC_MODE_OFF) { |
| /* Flush metadata before actually changing the image size */ |
| ret = bdrv_flush(bs); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, |
| "Failed to flush the preallocated area to disk"); |
| return ret; |
| } |
| } |
| |
| /* write updated header.size */ |
| offset = cpu_to_be64(offset); |
| ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, size), |
| &offset, sizeof(uint64_t)); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Failed to update the image size"); |
| return ret; |
| } |
| |
| s->l1_vm_state_index = new_l1_size; |
| return 0; |
| } |
| |
| /* 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(BlockDriverState *bs, uint64_t offset, |
| uint64_t bytes, QEMUIOVector *qiov) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| QEMUIOVector hd_qiov; |
| struct iovec iov; |
| z_stream strm; |
| int ret, out_len; |
| uint8_t *buf, *out_buf; |
| int64_t cluster_offset; |
| |
| if (bytes == 0) { |
| /* align end of file to a sector boundary to ease reading with |
| sector based I/Os */ |
| cluster_offset = bdrv_getlength(bs->file->bs); |
| if (cluster_offset < 0) { |
| return cluster_offset; |
| } |
| return bdrv_truncate(bs->file, cluster_offset, PREALLOC_MODE_OFF, NULL); |
| } |
| |
| if (offset_into_cluster(s, offset)) { |
| return -EINVAL; |
| } |
| |
| buf = qemu_blockalign(bs, s->cluster_size); |
| if (bytes != s->cluster_size) { |
| if (bytes > s->cluster_size || |
| offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS) |
| { |
| qemu_vfree(buf); |
| return -EINVAL; |
| } |
| /* Zero-pad last write if image size is not cluster aligned */ |
| memset(buf + bytes, 0, s->cluster_size - bytes); |
| } |
| qemu_iovec_to_buf(qiov, 0, buf, bytes); |
| |
| out_buf = g_malloc(s->cluster_size); |
| |
| /* best compression, small window, no zlib header */ |
| memset(&strm, 0, sizeof(strm)); |
| ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, |
| Z_DEFLATED, -12, |
| 9, Z_DEFAULT_STRATEGY); |
| if (ret != 0) { |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| strm.avail_in = s->cluster_size; |
| strm.next_in = (uint8_t *)buf; |
| strm.avail_out = s->cluster_size; |
| strm.next_out = out_buf; |
| |
| ret = deflate(&strm, Z_FINISH); |
| if (ret != Z_STREAM_END && ret != Z_OK) { |
| deflateEnd(&strm); |
| ret = -EINVAL; |
| goto fail; |
| } |
| out_len = strm.next_out - out_buf; |
| |
| deflateEnd(&strm); |
| |
| if (ret != Z_STREAM_END || out_len >= s->cluster_size) { |
| /* could not compress: write normal cluster */ |
| ret = qcow2_co_pwritev(bs, offset, bytes, qiov, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| goto success; |
| } |
| |
| qemu_co_mutex_lock(&s->lock); |
| cluster_offset = |
| qcow2_alloc_compressed_cluster_offset(bs, offset, out_len); |
| if (!cluster_offset) { |
| qemu_co_mutex_unlock(&s->lock); |
| ret = -EIO; |
| goto fail; |
| } |
| cluster_offset &= s->cluster_offset_mask; |
| |
| ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len); |
| qemu_co_mutex_unlock(&s->lock); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| iov = (struct iovec) { |
| .iov_base = out_buf, |
| .iov_len = out_len, |
| }; |
| qemu_iovec_init_external(&hd_qiov, &iov, 1); |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); |
| ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| success: |
| ret = 0; |
| fail: |
| qemu_vfree(buf); |
| g_free(out_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 / sizeof(uint64_t)); |
| l1_size2 = (uint64_t)s->l1_size * sizeof(uint64_t); |
| |
| /* 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 / sizeof(uint64_t)); |
| if (!new_reftable) { |
| ret = -ENOMEM; |
| goto fail_broken_refcounts; |
| } |
| |
| s->refcount_table_offset = s->cluster_size; |
| s->refcount_table_size = s->cluster_size / sizeof(uint64_t); |
| 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, |
| PREALLOC_MODE_OFF, &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 / sizeof(uint64_t)); |
| |
| if (s->qcow_version >= 3 && !s->snapshots && !s->nb_bitmaps && |
| 3 + l1_clusters <= s->refcount_block_size && |
| s->crypt_method_header != QCOW_CRYPT_LUKS) { |
| /* 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. */ |
| 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; |
| size_t cluster_size; |
| int version; |
| char *optstr; |
| PreallocMode prealloc; |
| bool has_backing_file; |
| |
| /* Parse image creation options */ |
| cluster_size = qcow2_opt_get_cluster_size_del(opts, &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); |
| |
| 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 */ |
| l2_tables = DIV_ROUND_UP(virtual_size / cluster_size, |
| cluster_size / sizeof(uint64_t)); |
| if (l2_tables * sizeof(uint64_t) > 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_new(BlockMeasureInfo, 1); |
| info->fully_allocated = |
| qcow2_calc_prealloc_size(virtual_size, cluster_size, |
| ctz32(refcount_bits)); |
| |
| /* Remove data clusters that are not required. This overestimates the |
| * required size because metadata needed for the fully allocated file is |
| * still counted. |
| */ |
| info->required = info->fully_allocated - virtual_size + required; |
| return info; |
| |
| err: |
| error_propagate(errp, local_err); |
| return NULL; |
| } |
| |
| static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| bdi->unallocated_blocks_are_zero = true; |
| bdi->cluster_size = s->cluster_size; |
| bdi->vm_state_offset = qcow2_vm_state_offset(s); |
| return 0; |
| } |
| |
| static ImageInfoSpecific *qcow2_get_specific_info(BlockDriverState *bs) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| ImageInfoSpecific *spec_info; |
| QCryptoBlockInfo *encrypt_info = NULL; |
| |
| if (s->crypto != NULL) { |
| encrypt_info = qcrypto_block_get_info(s->crypto, &error_abort); |
| } |
| |
| spec_info = g_new(ImageInfoSpecific, 1); |
| *spec_info = (ImageInfoSpecific){ |
| .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2, |
| .u.qcow2.data = g_new(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) { |
| *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, |
| .refcount_bits = s->refcount_bits, |
| }; |
| } 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; |
| qencrypt->u.aes = encrypt_info->u.qcow; |
| 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_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, |
| int64_t pos) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); |
| return bs->drv->bdrv_co_pwritev(bs, qcow2_vm_state_offset(s) + pos, |
| qiov->size, qiov, 0); |
| } |
| |
| static int qcow2_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, |
| int64_t pos) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); |
| return bs->drv->bdrv_co_preadv(bs, qcow2_vm_state_offset(s) + pos, |
| qiov->size, qiov, 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) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| int current_version = s->qcow_version; |
| int ret; |
| |
| if (target_version == current_version) { |
| return 0; |
| } else if (target_version > current_version) { |
| return -EINVAL; |
| } else if (target_version != 2) { |
| return -EINVAL; |
| } |
| |
| if (s->refcount_order != 4) { |
| error_report("compat=0.10 requires refcount_bits=16"); |
| return -ENOTSUP; |
| } |
| |
| /* clear incompatible features */ |
| if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { |
| ret = qcow2_mark_clean(bs); |
| if (ret < 0) { |
| 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) { |
| 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) { |
| return ret; |
| } |
| |
| s->qcow_version = target_version; |
| ret = qcow2_update_header(bs); |
| if (ret < 0) { |
| s->qcow_version = current_version; |
| return ret; |
| } |
| 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_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) |
| { |
| 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; |
| bool lazy_refcounts = s->use_lazy_refcounts; |
| const char *compat = NULL; |
| uint64_t cluster_size = s->cluster_size; |
| bool encrypt; |
| int encformat; |
| int refcount_bits = s->refcount_bits; |
| Error *local_err = NULL; |
| int ret; |
| QemuOptDesc *desc = opts->list->desc; |
| Qcow2AmendHelperCBInfo helper_cb_info; |
| |
| 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")) { |
| new_version = 2; |
| } else if (!strcmp(compat, "1.1")) { |
| new_version = 3; |
| } else { |
| error_report("Unknown compatibility level %s", compat); |
| return -EINVAL; |
| } |
| } else if (!strcmp(desc->name, BLOCK_OPT_PREALLOC)) { |
| error_report("Cannot change preallocation mode"); |
| return -ENOTSUP; |
| } 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 (!strcmp(desc->name, BLOCK_OPT_ENCRYPT)) { |
| encrypt = qemu_opt_get_bool(opts, BLOCK_OPT_ENCRYPT, |
| !!s->crypto); |
| |
| if (encrypt != !!s->crypto) { |
| error_report("Changing the encryption flag is not supported"); |
| return -ENOTSUP; |
| } |
| } else if (!strcmp(desc->name, BLOCK_OPT_ENCRYPT_FORMAT)) { |
| encformat = qcow2_crypt_method_from_format( |
| qemu_opt_get(opts, BLOCK_OPT_ENCRYPT_FORMAT)); |
| |
| if (encformat != s->crypt_method_header) { |
| error_report("Changing the encryption format is not supported"); |
| return -ENOTSUP; |
| } |
| } else if (g_str_has_prefix(desc->name, "encrypt.")) { |
| error_report("Changing the encryption parameters is not supported"); |
| return -ENOTSUP; |
| } else if (!strcmp(desc->name, BLOCK_OPT_CLUSTER_SIZE)) { |
| cluster_size = qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, |
| cluster_size); |
| if (cluster_size != s->cluster_size) { |
| error_report("Changing the cluster size is not supported"); |
| return -ENOTSUP; |
| } |
| } 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_report("Refcount width must be a power of two and may " |
| "not exceed 64 bits"); |
| 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) |
| }; |
| |
| /* Upgrade first (some features may require compat=1.1) */ |
| if (new_version > old_version) { |
| s->qcow_version = new_version; |
| ret = qcow2_update_header(bs); |
| if (ret < 0) { |
| s->qcow_version = old_version; |
| return ret; |
| } |
| } |
| |
| if (s->refcount_bits != refcount_bits) { |
| int refcount_order = ctz32(refcount_bits); |
| |
| if (new_version < 3 && refcount_bits != 16) { |
| error_report("Different refcount widths 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, &local_err); |
| if (ret < 0) { |
| error_report_err(local_err); |
| return ret; |
| } |
| } |
| |
| if (backing_file || backing_format) { |
| ret = qcow2_change_backing_file(bs, |
| backing_file ?: s->image_backing_file, |
| backing_format ?: s->image_backing_format); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| if (s->use_lazy_refcounts != lazy_refcounts) { |
| if (lazy_refcounts) { |
| if (new_version < 3) { |
| error_report("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; |
| return ret; |
| } |
| s->use_lazy_refcounts = true; |
| } else { |
| /* make image clean first */ |
| ret = qcow2_mark_clean(bs); |
| if (ret < 0) { |
| 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; |
| return ret; |
| } |
| s->use_lazy_refcounts = false; |
| } |
| } |
| |
| if (new_size) { |
| BlockBackend *blk = blk_new(BLK_PERM_RESIZE, BLK_PERM_ALL); |
| ret = blk_insert_bs(blk, bs, &local_err); |
| if (ret < 0) { |
| error_report_err(local_err); |
| blk_unref(blk); |
| return ret; |
| } |
| |
| ret = blk_truncate(blk, new_size, PREALLOC_MODE_OFF, &local_err); |
| blk_unref(blk); |
| if (ret < 0) { |
| error_report_err(local_err); |
| 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); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * 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 && !bs->read_only; |
| |
| 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, &error_abort); |
| g_free(message); |
| |
| if (fatal) { |
| qcow2_mark_corrupt(bs); |
| bs->drv = NULL; /* make BDS unusable */ |
| } |
| |
| s->signaled_corruption = true; |
| } |
| |
| static QemuOptsList qcow2_create_opts = { |
| .name = "qcow2-create-opts", |
| .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head), |
| .desc = { |
| { |
| .name = BLOCK_OPT_SIZE, |
| .type = QEMU_OPT_SIZE, |
| .help = "Virtual disk size" |
| }, |
| { |
| .name = BLOCK_OPT_COMPAT_LEVEL, |
| .type = QEMU_OPT_STRING, |
| .help = "Compatibility level (0.10 or 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_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_PREALLOC, |
| .type = QEMU_OPT_STRING, |
| .help = "Preallocation mode (allowed values: off, metadata, " |
| "falloc, full)" |
| }, |
| { |
| .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" |
| }, |
| { /* end of list */ } |
| } |
| }; |
| |
| 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_abort = qcow2_reopen_abort, |
| .bdrv_join_options = qcow2_join_options, |
| .bdrv_child_perm = bdrv_format_default_perms, |
| .bdrv_co_create_opts = qcow2_co_create_opts, |
| .bdrv_has_zero_init = bdrv_has_zero_init_1, |
| .bdrv_co_block_status = qcow2_co_block_status, |
| |
| .bdrv_co_preadv = qcow2_co_preadv, |
| .bdrv_co_pwritev = qcow2_co_pwritev, |
| .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_truncate = qcow2_truncate, |
| .bdrv_co_pwritev_compressed = qcow2_co_pwritev_compressed, |
| .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, |
| |
| .supports_backing = true, |
| .bdrv_change_backing_file = qcow2_change_backing_file, |
| |
| .bdrv_refresh_limits = qcow2_refresh_limits, |
| .bdrv_invalidate_cache = qcow2_invalidate_cache, |
| .bdrv_inactivate = qcow2_inactivate, |
| |
| .create_opts = &qcow2_create_opts, |
| .bdrv_check = qcow2_check, |
| .bdrv_amend_options = qcow2_amend_options, |
| |
| .bdrv_detach_aio_context = qcow2_detach_aio_context, |
| .bdrv_attach_aio_context = qcow2_attach_aio_context, |
| |
| .bdrv_reopen_bitmaps_rw = qcow2_reopen_bitmaps_rw, |
| .bdrv_can_store_new_dirty_bitmap = qcow2_can_store_new_dirty_bitmap, |
| .bdrv_remove_persistent_dirty_bitmap = qcow2_remove_persistent_dirty_bitmap, |
| }; |
| |
| static void bdrv_qcow2_init(void) |
| { |
| bdrv_register(&bdrv_qcow2); |
| } |
| |
| block_init(bdrv_qcow2_init); |