| /* |
| * 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-common.h" |
| #include "block/block_int.h" |
| #include "qemu/module.h" |
| #include <zlib.h> |
| #include "qemu/aes.h" |
| #include "block/qcow2.h" |
| #include "qemu/error-report.h" |
| #include "qapi/qmp/qerror.h" |
| #include "qapi/qmp/qbool.h" |
| #include "qapi/util.h" |
| #include "qapi/qmp/types.h" |
| #include "qapi-event.h" |
| #include "trace.h" |
| #include "qemu/option_int.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 |
| |
| 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; |
| } |
| |
| |
| /* |
| * 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, |
| Error **errp) |
| { |
| BDRVQcowState *s = bs->opaque; |
| QCowExtension ext; |
| uint64_t offset; |
| int ret; |
| |
| #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'; |
| #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; |
| |
| default: |
| /* unknown magic - save it in case we need to rewrite the header */ |
| { |
| 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) |
| { |
| BDRVQcowState *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 GCC_FMT_ATTR(3, 4) report_unsupported(BlockDriverState *bs, |
| Error **errp, const char *fmt, ...) |
| { |
| char msg[64]; |
| va_list ap; |
| |
| va_start(ap, fmt); |
| vsnprintf(msg, sizeof(msg), fmt, ap); |
| va_end(ap); |
| |
| error_set(errp, QERR_UNKNOWN_BLOCK_FORMAT_FEATURE, |
| bdrv_get_device_name(bs), "qcow2", msg); |
| } |
| |
| static void report_unsupported_feature(BlockDriverState *bs, |
| 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); |
| } |
| |
| report_unsupported(bs, errp, "%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) |
| { |
| BDRVQcowState *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); |
| 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) |
| { |
| BDRVQcowState *s = bs->opaque; |
| |
| if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { |
| int ret; |
| |
| s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; |
| |
| ret = bdrv_flush(bs); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| return qcow2_update_header(bs); |
| } |
| return 0; |
| } |
| |
| /* |
| * Marks the image as corrupt. |
| */ |
| int qcow2_mark_corrupt(BlockDriverState *bs) |
| { |
| BDRVQcowState *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) |
| { |
| BDRVQcowState *s = bs->opaque; |
| |
| if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { |
| int ret = bdrv_flush(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) |
| { |
| BDRVQcowState *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 & (s->cluster_size - 1)) { |
| 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_REFCOUNT_CACHE_SIZE, |
| .type = QEMU_OPT_SIZE, |
| .help = "Maximum refcount block cache size", |
| }, |
| { /* 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 read_cache_sizes(QemuOpts *opts, uint64_t *l2_cache_size, |
| uint64_t *refcount_cache_size, Error **errp) |
| { |
| 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); |
| |
| 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 = DEFAULT_L2_CACHE_BYTE_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; |
| } |
| } |
| } |
| |
| static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, |
| Error **errp) |
| { |
| BDRVQcowState *s = bs->opaque; |
| unsigned int len, i; |
| int ret = 0; |
| QCowHeader header; |
| QemuOpts *opts = NULL; |
| Error *local_err = NULL; |
| uint64_t ext_end; |
| uint64_t l1_vm_state_index; |
| const char *opt_overlap_check, *opt_overlap_check_template; |
| int overlap_check_template = 0; |
| uint64_t l2_cache_size, refcount_cache_size; |
| |
| 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) { |
| report_unsupported(bs, errp, "QCOW 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 - 9); |
| |
| /* 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, NULL); |
| report_unsupported_feature(bs, 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 != 4) { |
| report_unsupported(bs, errp, "%d bit reference counts", |
| 1 << header.refcount_order); |
| ret = -ENOTSUP; |
| goto fail; |
| } |
| s->refcount_order = header.refcount_order; |
| |
| if (header.crypt_method > QCOW_CRYPT_AES) { |
| error_setg(errp, "Unsupported encryption method: %" PRIu32, |
| header.crypt_method); |
| ret = -EINVAL; |
| goto fail; |
| } |
| s->crypt_method_header = header.crypt_method; |
| if (s->crypt_method_header) { |
| bs->encrypted = 1; |
| } |
| |
| 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; |
| } |
| |
| 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) { |
| 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, |
| align_offset(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]); |
| } |
| } |
| |
| /* get L2 table/refcount block cache size from command line options */ |
| 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; |
| } |
| |
| read_cache_sizes(opts, &l2_cache_size, &refcount_cache_size, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| l2_cache_size /= s->cluster_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 L2 table/refcount block cache */ |
| s->l2_table_cache = qcow2_cache_create(bs, l2_cache_size); |
| s->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size); |
| if (s->l2_table_cache == NULL || s->refcount_block_cache == NULL) { |
| error_setg(errp, "Could not allocate metadata caches"); |
| ret = -ENOMEM; |
| goto fail; |
| } |
| |
| s->cluster_cache = g_malloc(s->cluster_size); |
| /* one more sector for decompressed data alignment */ |
| s->cluster_data = qemu_try_blockalign(bs->file, QCOW_MAX_CRYPT_CLUSTERS |
| * s->cluster_size + 512); |
| if (s->cluster_data == NULL) { |
| error_setg(errp, "Could not allocate temporary cluster buffer"); |
| ret = -ENOMEM; |
| 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, |
| &local_err)) { |
| error_propagate(errp, local_err); |
| 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'; |
| } |
| |
| /* 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 */ |
| if (!bs->read_only && !(flags & BDRV_O_INCOMING) && s->autoclear_features) { |
| s->autoclear_features = 0; |
| 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); |
| |
| /* Repair image if dirty */ |
| if (!(flags & (BDRV_O_CHECK | BDRV_O_INCOMING)) && !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) { |
| error_setg_errno(errp, -ret, "Could not repair dirty image"); |
| goto fail; |
| } |
| } |
| |
| /* Enable lazy_refcounts according to image and command line options */ |
| s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, |
| (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); |
| |
| s->discard_passthrough[QCOW2_DISCARD_NEVER] = false; |
| s->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; |
| s->discard_passthrough[QCOW2_DISCARD_REQUEST] = |
| qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, |
| flags & BDRV_O_UNMAP); |
| s->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = |
| qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); |
| s->discard_passthrough[QCOW2_DISCARD_OTHER] = |
| qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); |
| |
| 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 either of the following: " |
| "none, constant, cached, all", opt_overlap_check); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| s->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 */ |
| s->overlap_check |= |
| qemu_opt_get_bool(opts, overlap_bool_option_names[i], |
| overlap_check_template & (1 << i)) << i; |
| } |
| |
| qemu_opts_del(opts); |
| opts = NULL; |
| |
| if (s->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; |
| } |
| |
| #ifdef DEBUG_ALLOC |
| { |
| BdrvCheckResult result = {0}; |
| qcow2_check_refcounts(bs, &result, 0); |
| } |
| #endif |
| return ret; |
| |
| fail: |
| qemu_opts_del(opts); |
| 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; |
| if (s->l2_table_cache) { |
| qcow2_cache_destroy(bs, s->l2_table_cache); |
| } |
| if (s->refcount_block_cache) { |
| qcow2_cache_destroy(bs, s->refcount_block_cache); |
| } |
| g_free(s->cluster_cache); |
| qemu_vfree(s->cluster_data); |
| return ret; |
| } |
| |
| static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) |
| { |
| BDRVQcowState *s = bs->opaque; |
| |
| bs->bl.write_zeroes_alignment = s->cluster_sectors; |
| } |
| |
| static int qcow2_set_key(BlockDriverState *bs, const char *key) |
| { |
| BDRVQcowState *s = bs->opaque; |
| uint8_t keybuf[16]; |
| int len, i; |
| |
| memset(keybuf, 0, 16); |
| len = strlen(key); |
| if (len > 16) |
| len = 16; |
| /* XXX: we could compress the chars to 7 bits to increase |
| entropy */ |
| for(i = 0;i < len;i++) { |
| keybuf[i] = key[i]; |
| } |
| s->crypt_method = s->crypt_method_header; |
| |
| if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0) |
| return -1; |
| if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0) |
| return -1; |
| #if 0 |
| /* test */ |
| { |
| uint8_t in[16]; |
| uint8_t out[16]; |
| uint8_t tmp[16]; |
| for(i=0;i<16;i++) |
| in[i] = i; |
| AES_encrypt(in, tmp, &s->aes_encrypt_key); |
| AES_decrypt(tmp, out, &s->aes_decrypt_key); |
| for(i = 0; i < 16; i++) |
| printf(" %02x", tmp[i]); |
| printf("\n"); |
| for(i = 0; i < 16; i++) |
| printf(" %02x", out[i]); |
| printf("\n"); |
| } |
| #endif |
| return 0; |
| } |
| |
| /* We have no actual commit/abort logic for qcow2, but we need to write out any |
| * unwritten data if we reopen read-only. */ |
| static int qcow2_reopen_prepare(BDRVReopenState *state, |
| BlockReopenQueue *queue, Error **errp) |
| { |
| int ret; |
| |
| if ((state->flags & BDRV_O_RDWR) == 0) { |
| ret = bdrv_flush(state->bs); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| ret = qcow2_mark_clean(state->bs); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, int *pnum) |
| { |
| BDRVQcowState *s = bs->opaque; |
| uint64_t cluster_offset; |
| int index_in_cluster, ret; |
| int64_t status = 0; |
| |
| *pnum = nb_sectors; |
| qemu_co_mutex_lock(&s->lock); |
| ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset); |
| qemu_co_mutex_unlock(&s->lock); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| if (cluster_offset != 0 && ret != QCOW2_CLUSTER_COMPRESSED && |
| !s->crypt_method) { |
| index_in_cluster = sector_num & (s->cluster_sectors - 1); |
| cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS); |
| status |= BDRV_BLOCK_OFFSET_VALID | cluster_offset; |
| } |
| if (ret == QCOW2_CLUSTER_ZERO) { |
| status |= BDRV_BLOCK_ZERO; |
| } else if (ret != QCOW2_CLUSTER_UNALLOCATED) { |
| status |= BDRV_BLOCK_DATA; |
| } |
| return status; |
| } |
| |
| /* handle reading after the end of the backing file */ |
| int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov, |
| int64_t sector_num, int nb_sectors) |
| { |
| int n1; |
| if ((sector_num + nb_sectors) <= bs->total_sectors) |
| return nb_sectors; |
| if (sector_num >= bs->total_sectors) |
| n1 = 0; |
| else |
| n1 = bs->total_sectors - sector_num; |
| |
| qemu_iovec_memset(qiov, 512 * n1, 0, 512 * (nb_sectors - n1)); |
| |
| return n1; |
| } |
| |
| static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, |
| int remaining_sectors, QEMUIOVector *qiov) |
| { |
| BDRVQcowState *s = bs->opaque; |
| int index_in_cluster, n1; |
| int ret; |
| int cur_nr_sectors; /* number of sectors 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 (remaining_sectors != 0) { |
| |
| /* prepare next request */ |
| cur_nr_sectors = remaining_sectors; |
| if (s->crypt_method) { |
| cur_nr_sectors = MIN(cur_nr_sectors, |
| QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
| } |
| |
| ret = qcow2_get_cluster_offset(bs, sector_num << 9, |
| &cur_nr_sectors, &cluster_offset); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| index_in_cluster = sector_num & (s->cluster_sectors - 1); |
| |
| qemu_iovec_reset(&hd_qiov); |
| qemu_iovec_concat(&hd_qiov, qiov, bytes_done, |
| cur_nr_sectors * 512); |
| |
| switch (ret) { |
| case QCOW2_CLUSTER_UNALLOCATED: |
| |
| if (bs->backing_hd) { |
| /* read from the base image */ |
| n1 = qcow2_backing_read1(bs->backing_hd, &hd_qiov, |
| sector_num, cur_nr_sectors); |
| if (n1 > 0) { |
| QEMUIOVector local_qiov; |
| |
| qemu_iovec_init(&local_qiov, hd_qiov.niov); |
| qemu_iovec_concat(&local_qiov, &hd_qiov, 0, |
| n1 * BDRV_SECTOR_SIZE); |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); |
| qemu_co_mutex_unlock(&s->lock); |
| ret = bdrv_co_readv(bs->backing_hd, sector_num, |
| n1, &local_qiov); |
| qemu_co_mutex_lock(&s->lock); |
| |
| qemu_iovec_destroy(&local_qiov); |
| |
| if (ret < 0) { |
| goto fail; |
| } |
| } |
| } else { |
| /* Note: in this case, no need to wait */ |
| qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); |
| } |
| break; |
| |
| case QCOW2_CLUSTER_ZERO: |
| qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); |
| 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 + index_in_cluster * 512, |
| 512 * cur_nr_sectors); |
| break; |
| |
| case QCOW2_CLUSTER_NORMAL: |
| if ((cluster_offset & 511) != 0) { |
| ret = -EIO; |
| goto fail; |
| } |
| |
| if (s->crypt_method) { |
| /* |
| * 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, QCOW_MAX_CRYPT_CLUSTERS |
| * s->cluster_size); |
| if (cluster_data == NULL) { |
| ret = -ENOMEM; |
| goto fail; |
| } |
| } |
| |
| assert(cur_nr_sectors <= |
| QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors); |
| qemu_iovec_reset(&hd_qiov); |
| qemu_iovec_add(&hd_qiov, cluster_data, |
| 512 * cur_nr_sectors); |
| } |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
| qemu_co_mutex_unlock(&s->lock); |
| ret = bdrv_co_readv(bs->file, |
| (cluster_offset >> 9) + index_in_cluster, |
| cur_nr_sectors, &hd_qiov); |
| qemu_co_mutex_lock(&s->lock); |
| if (ret < 0) { |
| goto fail; |
| } |
| if (s->crypt_method) { |
| qcow2_encrypt_sectors(s, sector_num, cluster_data, |
| cluster_data, cur_nr_sectors, 0, &s->aes_decrypt_key); |
| qemu_iovec_from_buf(qiov, bytes_done, |
| cluster_data, 512 * cur_nr_sectors); |
| } |
| break; |
| |
| default: |
| g_assert_not_reached(); |
| ret = -EIO; |
| goto fail; |
| } |
| |
| remaining_sectors -= cur_nr_sectors; |
| sector_num += cur_nr_sectors; |
| bytes_done += cur_nr_sectors * 512; |
| } |
| ret = 0; |
| |
| fail: |
| qemu_co_mutex_unlock(&s->lock); |
| |
| qemu_iovec_destroy(&hd_qiov); |
| qemu_vfree(cluster_data); |
| |
| return ret; |
| } |
| |
| static coroutine_fn int qcow2_co_writev(BlockDriverState *bs, |
| int64_t sector_num, |
| int remaining_sectors, |
| QEMUIOVector *qiov) |
| { |
| BDRVQcowState *s = bs->opaque; |
| int index_in_cluster; |
| int ret; |
| int cur_nr_sectors; /* 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(), sector_num, |
| remaining_sectors); |
| |
| qemu_iovec_init(&hd_qiov, qiov->niov); |
| |
| s->cluster_cache_offset = -1; /* disable compressed cache */ |
| |
| qemu_co_mutex_lock(&s->lock); |
| |
| while (remaining_sectors != 0) { |
| |
| l2meta = NULL; |
| |
| trace_qcow2_writev_start_part(qemu_coroutine_self()); |
| index_in_cluster = sector_num & (s->cluster_sectors - 1); |
| cur_nr_sectors = remaining_sectors; |
| if (s->crypt_method && |
| cur_nr_sectors > |
| QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster) { |
| cur_nr_sectors = |
| QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors - index_in_cluster; |
| } |
| |
| ret = qcow2_alloc_cluster_offset(bs, sector_num << 9, |
| &cur_nr_sectors, &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_nr_sectors * 512); |
| |
| if (s->crypt_method) { |
| if (!cluster_data) { |
| cluster_data = qemu_try_blockalign(bs->file, |
| 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); |
| |
| qcow2_encrypt_sectors(s, sector_num, cluster_data, |
| cluster_data, cur_nr_sectors, 1, &s->aes_encrypt_key); |
| |
| qemu_iovec_reset(&hd_qiov); |
| qemu_iovec_add(&hd_qiov, cluster_data, |
| cur_nr_sectors * 512); |
| } |
| |
| ret = qcow2_pre_write_overlap_check(bs, 0, |
| cluster_offset + index_in_cluster * BDRV_SECTOR_SIZE, |
| cur_nr_sectors * BDRV_SECTOR_SIZE); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| qemu_co_mutex_unlock(&s->lock); |
| BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); |
| trace_qcow2_writev_data(qemu_coroutine_self(), |
| (cluster_offset >> 9) + index_in_cluster); |
| ret = bdrv_co_writev(bs->file, |
| (cluster_offset >> 9) + index_in_cluster, |
| cur_nr_sectors, &hd_qiov); |
| 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; |
| } |
| |
| remaining_sectors -= cur_nr_sectors; |
| sector_num += cur_nr_sectors; |
| bytes_done += cur_nr_sectors * 512; |
| trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_nr_sectors); |
| } |
| ret = 0; |
| |
| fail: |
| qemu_co_mutex_unlock(&s->lock); |
| |
| 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_iovec_destroy(&hd_qiov); |
| qemu_vfree(cluster_data); |
| trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); |
| |
| return ret; |
| } |
| |
| static void qcow2_close(BlockDriverState *bs) |
| { |
| BDRVQcowState *s = bs->opaque; |
| qemu_vfree(s->l1_table); |
| /* else pre-write overlap checks in cache_destroy may crash */ |
| s->l1_table = NULL; |
| |
| if (!(bs->open_flags & BDRV_O_INCOMING)) { |
| int ret1, ret2; |
| |
| ret1 = qcow2_cache_flush(bs, s->l2_table_cache); |
| ret2 = qcow2_cache_flush(bs, s->refcount_block_cache); |
| |
| if (ret1) { |
| error_report("Failed to flush the L2 table cache: %s", |
| strerror(-ret1)); |
| } |
| if (ret2) { |
| error_report("Failed to flush the refcount block cache: %s", |
| strerror(-ret2)); |
| } |
| |
| if (!ret1 && !ret2) { |
| qcow2_mark_clean(bs); |
| } |
| } |
| |
| qcow2_cache_destroy(bs, s->l2_table_cache); |
| qcow2_cache_destroy(bs, s->refcount_block_cache); |
| |
| g_free(s->unknown_header_fields); |
| cleanup_unknown_header_ext(bs); |
| |
| 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) |
| { |
| BDRVQcowState *s = bs->opaque; |
| int flags = s->flags; |
| AES_KEY aes_encrypt_key; |
| AES_KEY aes_decrypt_key; |
| uint32_t crypt_method = 0; |
| 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. |
| */ |
| |
| if (s->crypt_method) { |
| crypt_method = s->crypt_method; |
| memcpy(&aes_encrypt_key, &s->aes_encrypt_key, sizeof(aes_encrypt_key)); |
| memcpy(&aes_decrypt_key, &s->aes_decrypt_key, sizeof(aes_decrypt_key)); |
| } |
| |
| qcow2_close(bs); |
| |
| bdrv_invalidate_cache(bs->file, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return; |
| } |
| |
| memset(s, 0, sizeof(BDRVQcowState)); |
| options = qdict_clone_shallow(bs->options); |
| |
| ret = qcow2_open(bs, options, flags, &local_err); |
| QDECREF(options); |
| if (local_err) { |
| error_setg(errp, "Could not reopen qcow2 layer: %s", |
| error_get_pretty(local_err)); |
| error_free(local_err); |
| return; |
| } else if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not reopen qcow2 layer"); |
| return; |
| } |
| |
| if (crypt_method) { |
| s->crypt_method = crypt_method; |
| memcpy(&s->aes_encrypt_key, &aes_encrypt_key, sizeof(aes_encrypt_key)); |
| memcpy(&s->aes_decrypt_key, &aes_decrypt_key, sizeof(aes_decrypt_key)); |
| } |
| } |
| |
| 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), |
| }; |
| 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) |
| { |
| BDRVQcowState *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 (*bs->backing_format) { |
| ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BACKING_FORMAT, |
| bs->backing_format, strlen(bs->backing_format), |
| buflen); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| buf += ret; |
| buflen -= ret; |
| } |
| |
| /* Feature table */ |
| 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; |
| |
| /* 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 (*bs->backing_file) { |
| size_t backing_file_len = strlen(bs->backing_file); |
| |
| if (buflen < backing_file_len) { |
| ret = -ENOSPC; |
| goto fail; |
| } |
| |
| /* Using strncpy is ok here, since buf is not NUL-terminated. */ |
| strncpy(buf, bs->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) |
| { |
| pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); |
| pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); |
| |
| return qcow2_update_header(bs); |
| } |
| |
| static int preallocate(BlockDriverState *bs) |
| { |
| uint64_t nb_sectors; |
| uint64_t offset; |
| uint64_t host_offset = 0; |
| int num; |
| int ret; |
| QCowL2Meta *meta; |
| |
| nb_sectors = bdrv_nb_sectors(bs); |
| offset = 0; |
| |
| while (nb_sectors) { |
| num = MIN(nb_sectors, INT_MAX >> BDRV_SECTOR_BITS); |
| ret = qcow2_alloc_cluster_offset(bs, offset, &num, |
| &host_offset, &meta); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| 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); |
| return ret; |
| } |
| |
| /* 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 */ |
| |
| nb_sectors -= num; |
| offset += num << BDRV_SECTOR_BITS; |
| } |
| |
| /* |
| * 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 buf[BDRV_SECTOR_SIZE]; |
| memset(buf, 0, BDRV_SECTOR_SIZE); |
| ret = bdrv_write(bs->file, (host_offset >> BDRV_SECTOR_BITS) + num - 1, |
| buf, 1); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int qcow2_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, |
| Error **errp) |
| { |
| /* Calculate cluster_bits */ |
| int cluster_bits; |
| cluster_bits = ffs(cluster_size) - 1; |
| 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 -EINVAL; |
| } |
| |
| /* |
| * 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. |
| */ |
| BlockDriverState* bs; |
| QCowHeader *header; |
| uint64_t* refcount_table; |
| Error *local_err = NULL; |
| int ret; |
| |
| if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { |
| int64_t meta_size = 0; |
| uint64_t nreftablee, nrefblocke, nl1e, nl2e; |
| int64_t aligned_total_size = align_offset(total_size, cluster_size); |
| |
| /* header: 1 cluster */ |
| meta_size += cluster_size; |
| |
| /* total size of L2 tables */ |
| nl2e = aligned_total_size / cluster_size; |
| nl2e = align_offset(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 = align_offset(nl1e, cluster_size / sizeof(uint64_t)); |
| meta_size += nl1e * sizeof(uint64_t); |
| |
| /* total size of refcount blocks |
| * |
| * note: every host cluster is reference-counted, including metadata |
| * (even refcount blocks are recursively included). |
| * Let: |
| * a = total_size (this is the guest disk size) |
| * m = meta size not including refcount blocks and refcount tables |
| * c = cluster size |
| * y1 = number of refcount blocks entries |
| * y2 = meta size including everything |
| * then, |
| * y1 = (y2 + a)/c |
| * y2 = y1 * sizeof(u16) + y1 * sizeof(u16) * sizeof(u64) / c + m |
| * we can get y1: |
| * y1 = (a + m) / (c - sizeof(u16) - sizeof(u16) * sizeof(u64) / c) |
| */ |
| nrefblocke = (aligned_total_size + meta_size + cluster_size) / |
| (cluster_size - sizeof(uint16_t) - |
| 1.0 * sizeof(uint16_t) * sizeof(uint64_t) / cluster_size); |
| nrefblocke = align_offset(nrefblocke, cluster_size / sizeof(uint16_t)); |
| meta_size += nrefblocke * sizeof(uint16_t); |
| |
| /* total size of refcount tables */ |
| nreftablee = nrefblocke * sizeof(uint16_t) / cluster_size; |
| nreftablee = align_offset(nreftablee, cluster_size / sizeof(uint64_t)); |
| meta_size += nreftablee * sizeof(uint64_t); |
| |
| qemu_opt_set_number(opts, BLOCK_OPT_SIZE, |
| aligned_total_size + meta_size, &error_abort); |
| qemu_opt_set(opts, BLOCK_OPT_PREALLOC, PreallocMode_lookup[prealloc], |
| &error_abort); |
| } |
| |
| ret = bdrv_create_file(filename, opts, &local_err); |
| if (ret < 0) { |
| error_propagate(errp, local_err); |
| return ret; |
| } |
| |
| bs = NULL; |
| ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, |
| NULL, &local_err); |
| if (ret < 0) { |
| error_propagate(errp, local_err); |
| return ret; |
| } |
| |
| /* 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(cluster_bits), |
| .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(4), |
| .header_length = cpu_to_be32(sizeof(*header)), |
| }; |
| |
| if (flags & BLOCK_FLAG_ENCRYPT) { |
| header->crypt_method = cpu_to_be32(QCOW_CRYPT_AES); |
| } else { |
| 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 = bdrv_pwrite(bs, 0, header, cluster_size); |
| 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 = bdrv_pwrite(bs, cluster_size, refcount_table, 2 * cluster_size); |
| g_free(refcount_table); |
| |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not write refcount table"); |
| goto out; |
| } |
| |
| bdrv_unref(bs); |
| bs = 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) |
| */ |
| ret = bdrv_open(&bs, filename, NULL, NULL, |
| BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH, |
| &bdrv_qcow2, &local_err); |
| if (ret < 0) { |
| error_propagate(errp, local_err); |
| goto out; |
| } |
| |
| ret = qcow2_alloc_clusters(bs, 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(); |
| } |
| |
| /* Okay, now that we have a valid image, let's give it the right size */ |
| ret = bdrv_truncate(bs, total_size); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not resize image"); |
| goto out; |
| } |
| |
| /* Want a backing file? There you go.*/ |
| if (backing_file) { |
| ret = bdrv_change_backing_file(bs, 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; |
| } |
| } |
| |
| /* And if we're supposed to preallocate metadata, do that now */ |
| if (prealloc != PREALLOC_MODE_OFF) { |
| BDRVQcowState *s = bs->opaque; |
| qemu_co_mutex_lock(&s->lock); |
| ret = preallocate(bs); |
| qemu_co_mutex_unlock(&s->lock); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not preallocate metadata"); |
| goto out; |
| } |
| } |
| |
| bdrv_unref(bs); |
| bs = NULL; |
| |
| /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning */ |
| ret = bdrv_open(&bs, filename, NULL, NULL, |
| BDRV_O_RDWR | BDRV_O_CACHE_WB | BDRV_O_NO_BACKING, |
| &bdrv_qcow2, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| goto out; |
| } |
| |
| ret = 0; |
| out: |
| if (bs) { |
| bdrv_unref(bs); |
| } |
| return ret; |
| } |
| |
| static int qcow2_create(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 = 3; |
| 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); |
| if (qemu_opt_get_bool_del(opts, BLOCK_OPT_ENCRYPT, false)) { |
| flags |= BLOCK_FLAG_ENCRYPT; |
| } |
| cluster_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, |
| DEFAULT_CLUSTER_SIZE); |
| buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); |
| prealloc = qapi_enum_parse(PreallocMode_lookup, buf, |
| PREALLOC_MODE_MAX, PREALLOC_MODE_OFF, |
| &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto finish; |
| } |
| g_free(buf); |
| buf = qemu_opt_get_del(opts, BLOCK_OPT_COMPAT_LEVEL); |
| if (!buf) { |
| /* keep the default */ |
| } else if (!strcmp(buf, "0.10")) { |
| version = 2; |
| } else if (!strcmp(buf, "1.1")) { |
| version = 3; |
| } else { |
| error_setg(errp, "Invalid compatibility level: '%s'", buf); |
| 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; |
| } |
| |
| ret = qcow2_create2(filename, size, backing_file, backing_fmt, flags, |
| cluster_size, prealloc, opts, version, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| } |
| |
| finish: |
| g_free(backing_file); |
| g_free(backing_fmt); |
| g_free(buf); |
| return ret; |
| } |
| |
| static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, BdrvRequestFlags flags) |
| { |
| int ret; |
| BDRVQcowState *s = bs->opaque; |
| |
| /* Emulate misaligned zero writes */ |
| if (sector_num % s->cluster_sectors || nb_sectors % s->cluster_sectors) { |
| return -ENOTSUP; |
| } |
| |
| /* Whatever is left can use real zero clusters */ |
| qemu_co_mutex_lock(&s->lock); |
| ret = qcow2_zero_clusters(bs, sector_num << BDRV_SECTOR_BITS, |
| nb_sectors); |
| qemu_co_mutex_unlock(&s->lock); |
| |
| return ret; |
| } |
| |
| static coroutine_fn int qcow2_co_discard(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors) |
| { |
| int ret; |
| BDRVQcowState *s = bs->opaque; |
| |
| qemu_co_mutex_lock(&s->lock); |
| ret = qcow2_discard_clusters(bs, sector_num << BDRV_SECTOR_BITS, |
| nb_sectors, QCOW2_DISCARD_REQUEST, false); |
| qemu_co_mutex_unlock(&s->lock); |
| return ret; |
| } |
| |
| static int qcow2_truncate(BlockDriverState *bs, int64_t offset) |
| { |
| BDRVQcowState *s = bs->opaque; |
| int64_t new_l1_size; |
| int ret; |
| |
| if (offset & 511) { |
| error_report("The new size must be a multiple of 512"); |
| return -EINVAL; |
| } |
| |
| /* cannot proceed if image has snapshots */ |
| if (s->nb_snapshots) { |
| error_report("Can't resize an image which has snapshots"); |
| return -ENOTSUP; |
| } |
| |
| /* shrinking is currently not supported */ |
| if (offset < bs->total_sectors * 512) { |
| error_report("qcow2 doesn't support shrinking images yet"); |
| return -ENOTSUP; |
| } |
| |
| new_l1_size = size_to_l1(s, offset); |
| ret = qcow2_grow_l1_table(bs, new_l1_size, true); |
| if (ret < 0) { |
| 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) { |
| 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 int qcow2_write_compressed(BlockDriverState *bs, int64_t sector_num, |
| const uint8_t *buf, int nb_sectors) |
| { |
| BDRVQcowState *s = bs->opaque; |
| z_stream strm; |
| int ret, out_len; |
| uint8_t *out_buf; |
| uint64_t cluster_offset; |
| |
| if (nb_sectors == 0) { |
| /* align end of file to a sector boundary to ease reading with |
| sector based I/Os */ |
| cluster_offset = bdrv_getlength(bs->file); |
| return bdrv_truncate(bs->file, cluster_offset); |
| } |
| |
| if (nb_sectors != s->cluster_sectors) { |
| ret = -EINVAL; |
| |
| /* Zero-pad last write if image size is not cluster aligned */ |
| if (sector_num + nb_sectors == bs->total_sectors && |
| nb_sectors < s->cluster_sectors) { |
| uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); |
| memset(pad_buf, 0, s->cluster_size); |
| memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); |
| ret = qcow2_write_compressed(bs, sector_num, |
| pad_buf, s->cluster_sectors); |
| qemu_vfree(pad_buf); |
| } |
| return ret; |
| } |
| |
| out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); |
| |
| /* 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 = bdrv_write(bs, sector_num, buf, s->cluster_sectors); |
| if (ret < 0) { |
| goto fail; |
| } |
| } else { |
| cluster_offset = qcow2_alloc_compressed_cluster_offset(bs, |
| sector_num << 9, out_len); |
| if (!cluster_offset) { |
| ret = -EIO; |
| goto fail; |
| } |
| cluster_offset &= s->cluster_offset_mask; |
| |
| ret = qcow2_pre_write_overlap_check(bs, 0, cluster_offset, out_len); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED); |
| ret = bdrv_pwrite(bs->file, cluster_offset, out_buf, out_len); |
| if (ret < 0) { |
| goto fail; |
| } |
| } |
| |
| ret = 0; |
| fail: |
| g_free(out_buf); |
| return ret; |
| } |
| |
| static int make_completely_empty(BlockDriverState *bs) |
| { |
| BDRVQcowState *s = bs->opaque; |
| 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_write_zeroes(bs->file, s->l1_table_offset / BDRV_SECTOR_SIZE, |
| l1_clusters * s->cluster_sectors, 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_write_zeroes(bs->file, s->cluster_size / BDRV_SECTOR_SIZE, |
| (2 + l1_clusters) * s->cluster_size / |
| BDRV_SECTOR_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 */ |
| cpu_to_be64w(&l1_ofs_rt_ofs_cls.l1_offset, 3 * s->cluster_size); |
| cpu_to_be64w(&l1_ofs_rt_ofs_cls.reftable_offset, s->cluster_size); |
| cpu_to_be32w(&l1_ofs_rt_ofs_cls.reftable_clusters, 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); |
| |
| 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); |
| if (ret < 0) { |
| 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) |
| { |
| BDRVQcowState *s = bs->opaque; |
| uint64_t start_sector; |
| int sector_step = INT_MAX / BDRV_SECTOR_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 && |
| 3 + l1_clusters <= s->refcount_block_size) { |
| /* The following function only works for qcow2 v3 images (it requires |
| * the dirty flag) and only as long as there are no snapshots (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 */ |
| for (start_sector = 0; start_sector < bs->total_sectors; |
| start_sector += sector_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_discard_clusters(bs, start_sector * BDRV_SECTOR_SIZE, |
| MIN(sector_step, |
| bs->total_sectors - start_sector), |
| QCOW2_DISCARD_SNAPSHOT, true); |
| if (ret < 0) { |
| break; |
| } |
| } |
| |
| return ret; |
| } |
| |
| static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs) |
| { |
| BDRVQcowState *s = bs->opaque; |
| int ret; |
| |
| qemu_co_mutex_lock(&s->lock); |
| ret = qcow2_cache_flush(bs, s->l2_table_cache); |
| if (ret < 0) { |
| qemu_co_mutex_unlock(&s->lock); |
| return ret; |
| } |
| |
| if (qcow2_need_accurate_refcounts(s)) { |
| ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
| if (ret < 0) { |
| qemu_co_mutex_unlock(&s->lock); |
| return ret; |
| } |
| } |
| qemu_co_mutex_unlock(&s->lock); |
| |
| return 0; |
| } |
| |
| static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
| { |
| BDRVQcowState *s = bs->opaque; |
| bdi->unallocated_blocks_are_zero = true; |
| bdi->can_write_zeroes_with_unmap = (s->qcow_version >= 3); |
| 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) |
| { |
| BDRVQcowState *s = bs->opaque; |
| ImageInfoSpecific *spec_info = g_new(ImageInfoSpecific, 1); |
| |
| *spec_info = (ImageInfoSpecific){ |
| .kind = IMAGE_INFO_SPECIFIC_KIND_QCOW2, |
| { |
| .qcow2 = g_new(ImageInfoSpecificQCow2, 1), |
| }, |
| }; |
| if (s->qcow_version == 2) { |
| *spec_info->qcow2 = (ImageInfoSpecificQCow2){ |
| .compat = g_strdup("0.10"), |
| }; |
| } else if (s->qcow_version == 3) { |
| *spec_info->qcow2 = (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, |
| }; |
| } |
| |
| return spec_info; |
| } |
| |
| #if 0 |
| static void dump_refcounts(BlockDriverState *bs) |
| { |
| BDRVQcowState *s = bs->opaque; |
| int64_t nb_clusters, k, k1, size; |
| int refcount; |
| |
| size = bdrv_getlength(bs->file); |
| nb_clusters = size_to_clusters(s, size); |
| for(k = 0; k < nb_clusters;) { |
| k1 = k; |
| refcount = get_refcount(bs, k); |
| k++; |
| while (k < nb_clusters && get_refcount(bs, k) == refcount) |
| k++; |
| printf("%" PRId64 ": refcount=%d nb=%" PRId64 "\n", k, refcount, |
| k - k1); |
| } |
| } |
| #endif |
| |
| static int qcow2_save_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, |
| int64_t pos) |
| { |
| BDRVQcowState *s = bs->opaque; |
| int64_t total_sectors = bs->total_sectors; |
| bool zero_beyond_eof = bs->zero_beyond_eof; |
| int ret; |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_SAVE); |
| bs->zero_beyond_eof = false; |
| ret = bdrv_pwritev(bs, qcow2_vm_state_offset(s) + pos, qiov); |
| bs->zero_beyond_eof = zero_beyond_eof; |
| |
| /* bdrv_co_do_writev will have increased the total_sectors value to include |
| * the VM state - the VM state is however not an actual part of the block |
| * device, therefore, we need to restore the old value. */ |
| bs->total_sectors = total_sectors; |
| |
| return ret; |
| } |
| |
| static int qcow2_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
| int64_t pos, int size) |
| { |
| BDRVQcowState *s = bs->opaque; |
| bool zero_beyond_eof = bs->zero_beyond_eof; |
| int ret; |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_VMSTATE_LOAD); |
| bs->zero_beyond_eof = false; |
| ret = bdrv_pread(bs, qcow2_vm_state_offset(s) + pos, buf, size); |
| bs->zero_beyond_eof = zero_beyond_eof; |
| |
| return ret; |
| } |
| |
| /* |
| * 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) |
| { |
| BDRVQcowState *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) { |
| /* we would have to convert the image to a refcount_order == 4 image |
| * here; however, since qemu (at the time of writing this) does not |
| * support anything different than 4 anyway, there is no point in doing |
| * so right now; however, we should error out (if qemu supports this in |
| * the future and this code has not been adapted) */ |
| error_report("qcow2_downgrade: Image refcount orders other than 4 are " |
| "currently not supported."); |
| 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); |
| 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; |
| } |
| |
| static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, |
| BlockDriverAmendStatusCB *status_cb) |
| { |
| BDRVQcowState *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 ret; |
| QemuOptDesc *desc = opts->list->desc; |
| |
| while (desc && desc->name) { |
| if (!qemu_opt_find(opts, desc->name)) { |
| /* only change explicitly defined options */ |
| desc++; |
| continue; |
| } |
| |
| if (!strcmp(desc->name, "compat")) { |
| compat = qemu_opt_get(opts, "compat"); |
| if (!compat) { |
| /* preserve default */ |
| } else if (!strcmp(compat, "0.10")) { |
| new_version = 2; |
| } else if (!strcmp(compat, "1.1")) { |
| new_version = 3; |
| } else { |
| fprintf(stderr, "Unknown compatibility level %s.\n", compat); |
| return -EINVAL; |
| } |
| } else if (!strcmp(desc->name, "preallocation")) { |
| fprintf(stderr, "Cannot change preallocation mode.\n"); |
| return -ENOTSUP; |
| } else if (!strcmp(desc->name, "size")) { |
| new_size = qemu_opt_get_size(opts, "size", 0); |
| } else if (!strcmp(desc->name, "backing_file")) { |
| backing_file = qemu_opt_get(opts, "backing_file"); |
| } else if (!strcmp(desc->name, "backing_fmt")) { |
| backing_format = qemu_opt_get(opts, "backing_fmt"); |
| } else if (!strcmp(desc->name, "encryption")) { |
| encrypt = qemu_opt_get_bool(opts, "encryption", s->crypt_method); |
| if (encrypt != !!s->crypt_method) { |
| fprintf(stderr, "Changing the encryption flag is not " |
| "supported.\n"); |
| return -ENOTSUP; |
| } |
| } else if (!strcmp(desc->name, "cluster_size")) { |
| cluster_size = qemu_opt_get_size(opts, "cluster_size", |
| cluster_size); |
| if (cluster_size != s->cluster_size) { |
| fprintf(stderr, "Changing the cluster size is not " |
| "supported.\n"); |
| return -ENOTSUP; |
| } |
| } else if (!strcmp(desc->name, "lazy_refcounts")) { |
| lazy_refcounts = qemu_opt_get_bool(opts, "lazy_refcounts", |
| lazy_refcounts); |
| } else { |
| /* if this assertion fails, this probably means a new option was |
| * added without having it covered here */ |
| assert(false); |
| } |
| |
| desc++; |
| } |
| |
| if (new_version != old_version) { |
| if (new_version > old_version) { |
| /* Upgrade */ |
| s->qcow_version = new_version; |
| ret = qcow2_update_header(bs); |
| if (ret < 0) { |
| s->qcow_version = old_version; |
| return ret; |
| } |
| } else { |
| ret = qcow2_downgrade(bs, new_version, status_cb); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| } |
| |
| if (backing_file || backing_format) { |
| ret = qcow2_change_backing_file(bs, backing_file ?: bs->backing_file, |
| backing_format ?: bs->backing_format); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| if (s->use_lazy_refcounts != lazy_refcounts) { |
| if (lazy_refcounts) { |
| if (s->qcow_version < 3) { |
| fprintf(stderr, "Lazy refcounts only supported with compatibility " |
| "level 1.1 and above (use compat=1.1 or greater)\n"); |
| 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) { |
| ret = bdrv_truncate(bs, new_size); |
| 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, ...) |
| { |
| BDRVQcowState *s = bs->opaque; |
| 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); |
| } |
| |
| qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), 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", |
| .def_value_str = "off" |
| }, |
| { |
| .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" |
| }, |
| { /* end of list */ } |
| } |
| }; |
| |
| BlockDriver bdrv_qcow2 = { |
| .format_name = "qcow2", |
| .instance_size = sizeof(BDRVQcowState), |
| .bdrv_probe = qcow2_probe, |
| .bdrv_open = qcow2_open, |
| .bdrv_close = qcow2_close, |
| .bdrv_reopen_prepare = qcow2_reopen_prepare, |
| .bdrv_create = qcow2_create, |
| .bdrv_has_zero_init = bdrv_has_zero_init_1, |
| .bdrv_co_get_block_status = qcow2_co_get_block_status, |
| .bdrv_set_key = qcow2_set_key, |
| |
| .bdrv_co_readv = qcow2_co_readv, |
| .bdrv_co_writev = qcow2_co_writev, |
| .bdrv_co_flush_to_os = qcow2_co_flush_to_os, |
| |
| .bdrv_co_write_zeroes = qcow2_co_write_zeroes, |
| .bdrv_co_discard = qcow2_co_discard, |
| .bdrv_truncate = qcow2_truncate, |
| .bdrv_write_compressed = qcow2_write_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_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, |
| |
| .create_opts = &qcow2_create_opts, |
| .bdrv_check = qcow2_check, |
| .bdrv_amend_options = qcow2_amend_options, |
| }; |
| |
| static void bdrv_qcow2_init(void) |
| { |
| bdrv_register(&bdrv_qcow2); |
| } |
| |
| block_init(bdrv_qcow2_init); |