| /* |
| * Block driver for the QCOW version 2 format |
| * |
| * Copyright (c) 2004-2006 Fabrice Bellard |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| |
| #include "qemu/osdep.h" |
| |
| #include "block/qdict.h" |
| #include "sysemu/block-backend.h" |
| #include "qemu/main-loop.h" |
| #include "qemu/module.h" |
| #include "qcow2.h" |
| #include "qemu/error-report.h" |
| #include "qapi/error.h" |
| #include "qapi/qapi-events-block-core.h" |
| #include "qapi/qmp/qdict.h" |
| #include "qapi/qmp/qstring.h" |
| #include "trace.h" |
| #include "qemu/option_int.h" |
| #include "qemu/cutils.h" |
| #include "qemu/bswap.h" |
| #include "qapi/qobject-input-visitor.h" |
| #include "qapi/qapi-visit-block-core.h" |
| #include "crypto.h" |
| #include "block/aio_task.h" |
| |
| /* |
| Differences with QCOW: |
| |
| - Support for multiple incremental snapshots. |
| - Memory management by reference counts. |
| - Clusters which have a reference count of one have the bit |
| QCOW_OFLAG_COPIED to optimize write performance. |
| - Size of compressed clusters is stored in sectors to reduce bit usage |
| in the cluster offsets. |
| - Support for storing additional data (such as the VM state) in the |
| snapshots. |
| - If a backing store is used, the cluster size is not constrained |
| (could be backported to QCOW). |
| - L2 tables have always a size of one cluster. |
| */ |
| |
| |
| typedef struct { |
| uint32_t magic; |
| uint32_t len; |
| } QEMU_PACKED QCowExtension; |
| |
| #define QCOW2_EXT_MAGIC_END 0 |
| #define QCOW2_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA |
| #define QCOW2_EXT_MAGIC_FEATURE_TABLE 0x6803f857 |
| #define QCOW2_EXT_MAGIC_CRYPTO_HEADER 0x0537be77 |
| #define QCOW2_EXT_MAGIC_BITMAPS 0x23852875 |
| #define QCOW2_EXT_MAGIC_DATA_FILE 0x44415441 |
| |
| static int coroutine_fn |
| qcow2_co_preadv_compressed(BlockDriverState *bs, |
| uint64_t file_cluster_offset, |
| uint64_t offset, |
| uint64_t bytes, |
| QEMUIOVector *qiov, |
| size_t qiov_offset); |
| |
| static int qcow2_probe(const uint8_t *buf, int buf_size, const char *filename) |
| { |
| const QCowHeader *cow_header = (const void *)buf; |
| |
| if (buf_size >= sizeof(QCowHeader) && |
| be32_to_cpu(cow_header->magic) == QCOW_MAGIC && |
| be32_to_cpu(cow_header->version) >= 2) |
| return 100; |
| else |
| return 0; |
| } |
| |
| |
| static ssize_t qcow2_crypto_hdr_read_func(QCryptoBlock *block, size_t offset, |
| uint8_t *buf, size_t buflen, |
| void *opaque, Error **errp) |
| { |
| BlockDriverState *bs = opaque; |
| BDRVQcow2State *s = bs->opaque; |
| ssize_t ret; |
| |
| if ((offset + buflen) > s->crypto_header.length) { |
| error_setg(errp, "Request for data outside of extension header"); |
| return -1; |
| } |
| |
| ret = bdrv_pread(bs->file, |
| s->crypto_header.offset + offset, buf, buflen); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not read encryption header"); |
| return -1; |
| } |
| return ret; |
| } |
| |
| |
| static ssize_t qcow2_crypto_hdr_init_func(QCryptoBlock *block, size_t headerlen, |
| void *opaque, Error **errp) |
| { |
| BlockDriverState *bs = opaque; |
| BDRVQcow2State *s = bs->opaque; |
| int64_t ret; |
| int64_t clusterlen; |
| |
| ret = qcow2_alloc_clusters(bs, headerlen); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, |
| "Cannot allocate cluster for LUKS header size %zu", |
| headerlen); |
| return -1; |
| } |
| |
| s->crypto_header.length = headerlen; |
| s->crypto_header.offset = ret; |
| |
| /* |
| * Zero fill all space in cluster so it has predictable |
| * content, as we may not initialize some regions of the |
| * header (eg only 1 out of 8 key slots will be initialized) |
| */ |
| clusterlen = size_to_clusters(s, headerlen) * s->cluster_size; |
| assert(qcow2_pre_write_overlap_check(bs, 0, ret, clusterlen, false) == 0); |
| ret = bdrv_pwrite_zeroes(bs->file, |
| ret, |
| clusterlen, 0); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not zero fill encryption header"); |
| return -1; |
| } |
| |
| return ret; |
| } |
| |
| |
| static ssize_t qcow2_crypto_hdr_write_func(QCryptoBlock *block, size_t offset, |
| const uint8_t *buf, size_t buflen, |
| void *opaque, Error **errp) |
| { |
| BlockDriverState *bs = opaque; |
| BDRVQcow2State *s = bs->opaque; |
| ssize_t ret; |
| |
| if ((offset + buflen) > s->crypto_header.length) { |
| error_setg(errp, "Request for data outside of extension header"); |
| return -1; |
| } |
| |
| ret = bdrv_pwrite(bs->file, |
| s->crypto_header.offset + offset, buf, buflen); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not read encryption header"); |
| return -1; |
| } |
| return ret; |
| } |
| |
| |
| /* |
| * read qcow2 extension and fill bs |
| * start reading from start_offset |
| * finish reading upon magic of value 0 or when end_offset reached |
| * unknown magic is skipped (future extension this version knows nothing about) |
| * return 0 upon success, non-0 otherwise |
| */ |
| static int qcow2_read_extensions(BlockDriverState *bs, uint64_t start_offset, |
| uint64_t end_offset, void **p_feature_table, |
| int flags, bool *need_update_header, |
| Error **errp) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| QCowExtension ext; |
| uint64_t offset; |
| int ret; |
| Qcow2BitmapHeaderExt bitmaps_ext; |
| |
| if (need_update_header != NULL) { |
| *need_update_header = false; |
| } |
| |
| #ifdef DEBUG_EXT |
| printf("qcow2_read_extensions: start=%ld end=%ld\n", start_offset, end_offset); |
| #endif |
| offset = start_offset; |
| while (offset < end_offset) { |
| |
| #ifdef DEBUG_EXT |
| /* Sanity check */ |
| if (offset > s->cluster_size) |
| printf("qcow2_read_extension: suspicious offset %lu\n", offset); |
| |
| printf("attempting to read extended header in offset %lu\n", offset); |
| #endif |
| |
| ret = bdrv_pread(bs->file, offset, &ext, sizeof(ext)); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "qcow2_read_extension: ERROR: " |
| "pread fail from offset %" PRIu64, offset); |
| return 1; |
| } |
| ext.magic = be32_to_cpu(ext.magic); |
| ext.len = be32_to_cpu(ext.len); |
| offset += sizeof(ext); |
| #ifdef DEBUG_EXT |
| printf("ext.magic = 0x%x\n", ext.magic); |
| #endif |
| if (offset > end_offset || ext.len > end_offset - offset) { |
| error_setg(errp, "Header extension too large"); |
| return -EINVAL; |
| } |
| |
| switch (ext.magic) { |
| case QCOW2_EXT_MAGIC_END: |
| return 0; |
| |
| case QCOW2_EXT_MAGIC_BACKING_FORMAT: |
| if (ext.len >= sizeof(bs->backing_format)) { |
| error_setg(errp, "ERROR: ext_backing_format: len=%" PRIu32 |
| " too large (>=%zu)", ext.len, |
| sizeof(bs->backing_format)); |
| return 2; |
| } |
| ret = bdrv_pread(bs->file, offset, bs->backing_format, ext.len); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "ERROR: ext_backing_format: " |
| "Could not read format name"); |
| return 3; |
| } |
| bs->backing_format[ext.len] = '\0'; |
| s->image_backing_format = g_strdup(bs->backing_format); |
| #ifdef DEBUG_EXT |
| printf("Qcow2: Got format extension %s\n", bs->backing_format); |
| #endif |
| break; |
| |
| case QCOW2_EXT_MAGIC_FEATURE_TABLE: |
| if (p_feature_table != NULL) { |
| void* feature_table = g_malloc0(ext.len + 2 * sizeof(Qcow2Feature)); |
| ret = bdrv_pread(bs->file, offset , feature_table, ext.len); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "ERROR: ext_feature_table: " |
| "Could not read table"); |
| return ret; |
| } |
| |
| *p_feature_table = feature_table; |
| } |
| break; |
| |
| case QCOW2_EXT_MAGIC_CRYPTO_HEADER: { |
| unsigned int cflags = 0; |
| if (s->crypt_method_header != QCOW_CRYPT_LUKS) { |
| error_setg(errp, "CRYPTO header extension only " |
| "expected with LUKS encryption method"); |
| return -EINVAL; |
| } |
| if (ext.len != sizeof(Qcow2CryptoHeaderExtension)) { |
| error_setg(errp, "CRYPTO header extension size %u, " |
| "but expected size %zu", ext.len, |
| sizeof(Qcow2CryptoHeaderExtension)); |
| return -EINVAL; |
| } |
| |
| ret = bdrv_pread(bs->file, offset, &s->crypto_header, ext.len); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, |
| "Unable to read CRYPTO header extension"); |
| return ret; |
| } |
| s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); |
| s->crypto_header.length = be64_to_cpu(s->crypto_header.length); |
| |
| if ((s->crypto_header.offset % s->cluster_size) != 0) { |
| error_setg(errp, "Encryption header offset '%" PRIu64 "' is " |
| "not a multiple of cluster size '%u'", |
| s->crypto_header.offset, s->cluster_size); |
| return -EINVAL; |
| } |
| |
| if (flags & BDRV_O_NO_IO) { |
| cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; |
| } |
| s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", |
| qcow2_crypto_hdr_read_func, |
| bs, cflags, QCOW2_MAX_THREADS, errp); |
| if (!s->crypto) { |
| return -EINVAL; |
| } |
| } break; |
| |
| case QCOW2_EXT_MAGIC_BITMAPS: |
| if (ext.len != sizeof(bitmaps_ext)) { |
| error_setg_errno(errp, -ret, "bitmaps_ext: " |
| "Invalid extension length"); |
| return -EINVAL; |
| } |
| |
| if (!(s->autoclear_features & QCOW2_AUTOCLEAR_BITMAPS)) { |
| if (s->qcow_version < 3) { |
| /* Let's be a bit more specific */ |
| warn_report("This qcow2 v2 image contains bitmaps, but " |
| "they may have been modified by a program " |
| "without persistent bitmap support; so now " |
| "they must all be considered inconsistent"); |
| } else { |
| warn_report("a program lacking bitmap support " |
| "modified this file, so all bitmaps are now " |
| "considered inconsistent"); |
| } |
| error_printf("Some clusters may be leaked, " |
| "run 'qemu-img check -r' on the image " |
| "file to fix."); |
| if (need_update_header != NULL) { |
| /* Updating is needed to drop invalid bitmap extension. */ |
| *need_update_header = true; |
| } |
| break; |
| } |
| |
| ret = bdrv_pread(bs->file, offset, &bitmaps_ext, ext.len); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "bitmaps_ext: " |
| "Could not read ext header"); |
| return ret; |
| } |
| |
| if (bitmaps_ext.reserved32 != 0) { |
| error_setg_errno(errp, -ret, "bitmaps_ext: " |
| "Reserved field is not zero"); |
| return -EINVAL; |
| } |
| |
| bitmaps_ext.nb_bitmaps = be32_to_cpu(bitmaps_ext.nb_bitmaps); |
| bitmaps_ext.bitmap_directory_size = |
| be64_to_cpu(bitmaps_ext.bitmap_directory_size); |
| bitmaps_ext.bitmap_directory_offset = |
| be64_to_cpu(bitmaps_ext.bitmap_directory_offset); |
| |
| if (bitmaps_ext.nb_bitmaps > QCOW2_MAX_BITMAPS) { |
| error_setg(errp, |
| "bitmaps_ext: Image has %" PRIu32 " bitmaps, " |
| "exceeding the QEMU supported maximum of %d", |
| bitmaps_ext.nb_bitmaps, QCOW2_MAX_BITMAPS); |
| return -EINVAL; |
| } |
| |
| if (bitmaps_ext.nb_bitmaps == 0) { |
| error_setg(errp, "found bitmaps extension with zero bitmaps"); |
| return -EINVAL; |
| } |
| |
| if (offset_into_cluster(s, bitmaps_ext.bitmap_directory_offset)) { |
| error_setg(errp, "bitmaps_ext: " |
| "invalid bitmap directory offset"); |
| return -EINVAL; |
| } |
| |
| if (bitmaps_ext.bitmap_directory_size > |
| QCOW2_MAX_BITMAP_DIRECTORY_SIZE) { |
| error_setg(errp, "bitmaps_ext: " |
| "bitmap directory size (%" PRIu64 ") exceeds " |
| "the maximum supported size (%d)", |
| bitmaps_ext.bitmap_directory_size, |
| QCOW2_MAX_BITMAP_DIRECTORY_SIZE); |
| return -EINVAL; |
| } |
| |
| s->nb_bitmaps = bitmaps_ext.nb_bitmaps; |
| s->bitmap_directory_offset = |
| bitmaps_ext.bitmap_directory_offset; |
| s->bitmap_directory_size = |
| bitmaps_ext.bitmap_directory_size; |
| |
| #ifdef DEBUG_EXT |
| printf("Qcow2: Got bitmaps extension: " |
| "offset=%" PRIu64 " nb_bitmaps=%" PRIu32 "\n", |
| s->bitmap_directory_offset, s->nb_bitmaps); |
| #endif |
| break; |
| |
| case QCOW2_EXT_MAGIC_DATA_FILE: |
| { |
| s->image_data_file = g_malloc0(ext.len + 1); |
| ret = bdrv_pread(bs->file, offset, s->image_data_file, ext.len); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, |
| "ERROR: Could not read data file name"); |
| return ret; |
| } |
| #ifdef DEBUG_EXT |
| printf("Qcow2: Got external data file %s\n", s->image_data_file); |
| #endif |
| break; |
| } |
| |
| default: |
| /* unknown magic - save it in case we need to rewrite the header */ |
| /* If you add a new feature, make sure to also update the fast |
| * path of qcow2_make_empty() to deal with it. */ |
| { |
| Qcow2UnknownHeaderExtension *uext; |
| |
| uext = g_malloc0(sizeof(*uext) + ext.len); |
| uext->magic = ext.magic; |
| uext->len = ext.len; |
| QLIST_INSERT_HEAD(&s->unknown_header_ext, uext, next); |
| |
| ret = bdrv_pread(bs->file, offset , uext->data, uext->len); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "ERROR: unknown extension: " |
| "Could not read data"); |
| return ret; |
| } |
| } |
| break; |
| } |
| |
| offset += ((ext.len + 7) & ~7); |
| } |
| |
| return 0; |
| } |
| |
| static void cleanup_unknown_header_ext(BlockDriverState *bs) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| Qcow2UnknownHeaderExtension *uext, *next; |
| |
| QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { |
| QLIST_REMOVE(uext, next); |
| g_free(uext); |
| } |
| } |
| |
| static void report_unsupported_feature(Error **errp, Qcow2Feature *table, |
| uint64_t mask) |
| { |
| g_autoptr(GString) features = g_string_sized_new(60); |
| |
| while (table && table->name[0] != '\0') { |
| if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { |
| if (mask & (1ULL << table->bit)) { |
| if (features->len > 0) { |
| g_string_append(features, ", "); |
| } |
| g_string_append_printf(features, "%.46s", table->name); |
| mask &= ~(1ULL << table->bit); |
| } |
| } |
| table++; |
| } |
| |
| if (mask) { |
| if (features->len > 0) { |
| g_string_append(features, ", "); |
| } |
| g_string_append_printf(features, |
| "Unknown incompatible feature: %" PRIx64, mask); |
| } |
| |
| error_setg(errp, "Unsupported qcow2 feature(s): %s", features->str); |
| } |
| |
| /* |
| * Sets the dirty bit and flushes afterwards if necessary. |
| * |
| * The incompatible_features bit is only set if the image file header was |
| * updated successfully. Therefore it is not required to check the return |
| * value of this function. |
| */ |
| int qcow2_mark_dirty(BlockDriverState *bs) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| uint64_t val; |
| int ret; |
| |
| assert(s->qcow_version >= 3); |
| |
| if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { |
| return 0; /* already dirty */ |
| } |
| |
| val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); |
| ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features), |
| &val, sizeof(val)); |
| if (ret < 0) { |
| return ret; |
| } |
| ret = bdrv_flush(bs->file->bs); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| /* Only treat image as dirty if the header was updated successfully */ |
| s->incompatible_features |= QCOW2_INCOMPAT_DIRTY; |
| return 0; |
| } |
| |
| /* |
| * Clears the dirty bit and flushes before if necessary. Only call this |
| * function when there are no pending requests, it does not guard against |
| * concurrent requests dirtying the image. |
| */ |
| static int qcow2_mark_clean(BlockDriverState *bs) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| |
| if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { |
| int ret; |
| |
| s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY; |
| |
| ret = qcow2_flush_caches(bs); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| return qcow2_update_header(bs); |
| } |
| return 0; |
| } |
| |
| /* |
| * Marks the image as corrupt. |
| */ |
| int qcow2_mark_corrupt(BlockDriverState *bs) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| |
| s->incompatible_features |= QCOW2_INCOMPAT_CORRUPT; |
| return qcow2_update_header(bs); |
| } |
| |
| /* |
| * Marks the image as consistent, i.e., unsets the corrupt bit, and flushes |
| * before if necessary. |
| */ |
| int qcow2_mark_consistent(BlockDriverState *bs) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| |
| if (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT) { |
| int ret = qcow2_flush_caches(bs); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| s->incompatible_features &= ~QCOW2_INCOMPAT_CORRUPT; |
| return qcow2_update_header(bs); |
| } |
| return 0; |
| } |
| |
| static void qcow2_add_check_result(BdrvCheckResult *out, |
| const BdrvCheckResult *src, |
| bool set_allocation_info) |
| { |
| out->corruptions += src->corruptions; |
| out->leaks += src->leaks; |
| out->check_errors += src->check_errors; |
| out->corruptions_fixed += src->corruptions_fixed; |
| out->leaks_fixed += src->leaks_fixed; |
| |
| if (set_allocation_info) { |
| out->image_end_offset = src->image_end_offset; |
| out->bfi = src->bfi; |
| } |
| } |
| |
| static int coroutine_fn qcow2_co_check_locked(BlockDriverState *bs, |
| BdrvCheckResult *result, |
| BdrvCheckMode fix) |
| { |
| BdrvCheckResult snapshot_res = {}; |
| BdrvCheckResult refcount_res = {}; |
| int ret; |
| |
| memset(result, 0, sizeof(*result)); |
| |
| ret = qcow2_check_read_snapshot_table(bs, &snapshot_res, fix); |
| if (ret < 0) { |
| qcow2_add_check_result(result, &snapshot_res, false); |
| return ret; |
| } |
| |
| ret = qcow2_check_refcounts(bs, &refcount_res, fix); |
| qcow2_add_check_result(result, &refcount_res, true); |
| if (ret < 0) { |
| qcow2_add_check_result(result, &snapshot_res, false); |
| return ret; |
| } |
| |
| ret = qcow2_check_fix_snapshot_table(bs, &snapshot_res, fix); |
| qcow2_add_check_result(result, &snapshot_res, false); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| if (fix && result->check_errors == 0 && result->corruptions == 0) { |
| ret = qcow2_mark_clean(bs); |
| if (ret < 0) { |
| return ret; |
| } |
| return qcow2_mark_consistent(bs); |
| } |
| return ret; |
| } |
| |
| static int coroutine_fn qcow2_co_check(BlockDriverState *bs, |
| BdrvCheckResult *result, |
| BdrvCheckMode fix) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| int ret; |
| |
| qemu_co_mutex_lock(&s->lock); |
| ret = qcow2_co_check_locked(bs, result, fix); |
| qemu_co_mutex_unlock(&s->lock); |
| return ret; |
| } |
| |
| int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, |
| uint64_t entries, size_t entry_len, |
| int64_t max_size_bytes, const char *table_name, |
| Error **errp) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| |
| if (entries > max_size_bytes / entry_len) { |
| error_setg(errp, "%s too large", table_name); |
| return -EFBIG; |
| } |
| |
| /* Use signed INT64_MAX as the maximum even for uint64_t header fields, |
| * because values will be passed to qemu functions taking int64_t. */ |
| if ((INT64_MAX - entries * entry_len < offset) || |
| (offset_into_cluster(s, offset) != 0)) { |
| error_setg(errp, "%s offset invalid", table_name); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static const char *const mutable_opts[] = { |
| QCOW2_OPT_LAZY_REFCOUNTS, |
| QCOW2_OPT_DISCARD_REQUEST, |
| QCOW2_OPT_DISCARD_SNAPSHOT, |
| QCOW2_OPT_DISCARD_OTHER, |
| QCOW2_OPT_OVERLAP, |
| QCOW2_OPT_OVERLAP_TEMPLATE, |
| QCOW2_OPT_OVERLAP_MAIN_HEADER, |
| QCOW2_OPT_OVERLAP_ACTIVE_L1, |
| QCOW2_OPT_OVERLAP_ACTIVE_L2, |
| QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, |
| QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, |
| QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, |
| QCOW2_OPT_OVERLAP_INACTIVE_L1, |
| QCOW2_OPT_OVERLAP_INACTIVE_L2, |
| QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, |
| QCOW2_OPT_CACHE_SIZE, |
| QCOW2_OPT_L2_CACHE_SIZE, |
| QCOW2_OPT_L2_CACHE_ENTRY_SIZE, |
| QCOW2_OPT_REFCOUNT_CACHE_SIZE, |
| QCOW2_OPT_CACHE_CLEAN_INTERVAL, |
| NULL |
| }; |
| |
| static QemuOptsList qcow2_runtime_opts = { |
| .name = "qcow2", |
| .head = QTAILQ_HEAD_INITIALIZER(qcow2_runtime_opts.head), |
| .desc = { |
| { |
| .name = QCOW2_OPT_LAZY_REFCOUNTS, |
| .type = QEMU_OPT_BOOL, |
| .help = "Postpone refcount updates", |
| }, |
| { |
| .name = QCOW2_OPT_DISCARD_REQUEST, |
| .type = QEMU_OPT_BOOL, |
| .help = "Pass guest discard requests to the layer below", |
| }, |
| { |
| .name = QCOW2_OPT_DISCARD_SNAPSHOT, |
| .type = QEMU_OPT_BOOL, |
| .help = "Generate discard requests when snapshot related space " |
| "is freed", |
| }, |
| { |
| .name = QCOW2_OPT_DISCARD_OTHER, |
| .type = QEMU_OPT_BOOL, |
| .help = "Generate discard requests when other clusters are freed", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP, |
| .type = QEMU_OPT_STRING, |
| .help = "Selects which overlap checks to perform from a range of " |
| "templates (none, constant, cached, all)", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_TEMPLATE, |
| .type = QEMU_OPT_STRING, |
| .help = "Selects which overlap checks to perform from a range of " |
| "templates (none, constant, cached, all)", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_MAIN_HEADER, |
| .type = QEMU_OPT_BOOL, |
| .help = "Check for unintended writes into the main qcow2 header", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_ACTIVE_L1, |
| .type = QEMU_OPT_BOOL, |
| .help = "Check for unintended writes into the active L1 table", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_ACTIVE_L2, |
| .type = QEMU_OPT_BOOL, |
| .help = "Check for unintended writes into an active L2 table", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, |
| .type = QEMU_OPT_BOOL, |
| .help = "Check for unintended writes into the refcount table", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, |
| .type = QEMU_OPT_BOOL, |
| .help = "Check for unintended writes into a refcount block", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, |
| .type = QEMU_OPT_BOOL, |
| .help = "Check for unintended writes into the snapshot table", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_INACTIVE_L1, |
| .type = QEMU_OPT_BOOL, |
| .help = "Check for unintended writes into an inactive L1 table", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_INACTIVE_L2, |
| .type = QEMU_OPT_BOOL, |
| .help = "Check for unintended writes into an inactive L2 table", |
| }, |
| { |
| .name = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, |
| .type = QEMU_OPT_BOOL, |
| .help = "Check for unintended writes into the bitmap directory", |
| }, |
| { |
| .name = QCOW2_OPT_CACHE_SIZE, |
| .type = QEMU_OPT_SIZE, |
| .help = "Maximum combined metadata (L2 tables and refcount blocks) " |
| "cache size", |
| }, |
| { |
| .name = QCOW2_OPT_L2_CACHE_SIZE, |
| .type = QEMU_OPT_SIZE, |
| .help = "Maximum L2 table cache size", |
| }, |
| { |
| .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE, |
| .type = QEMU_OPT_SIZE, |
| .help = "Size of each entry in the L2 cache", |
| }, |
| { |
| .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE, |
| .type = QEMU_OPT_SIZE, |
| .help = "Maximum refcount block cache size", |
| }, |
| { |
| .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL, |
| .type = QEMU_OPT_NUMBER, |
| .help = "Clean unused cache entries after this time (in seconds)", |
| }, |
| BLOCK_CRYPTO_OPT_DEF_KEY_SECRET("encrypt.", |
| "ID of secret providing qcow2 AES key or LUKS passphrase"), |
| { /* end of list */ } |
| }, |
| }; |
| |
| static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = { |
| [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER, |
| [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1, |
| [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2, |
| [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, |
| [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, |
| [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, |
| [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1, |
| [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2, |
| [QCOW2_OL_BITMAP_DIRECTORY_BITNR] = QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY, |
| }; |
| |
| static void cache_clean_timer_cb(void *opaque) |
| { |
| BlockDriverState *bs = opaque; |
| BDRVQcow2State *s = bs->opaque; |
| qcow2_cache_clean_unused(s->l2_table_cache); |
| qcow2_cache_clean_unused(s->refcount_block_cache); |
| timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + |
| (int64_t) s->cache_clean_interval * 1000); |
| } |
| |
| static void cache_clean_timer_init(BlockDriverState *bs, AioContext *context) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| if (s->cache_clean_interval > 0) { |
| s->cache_clean_timer = aio_timer_new(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, l2_cache_max_setting; |
| bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; |
| bool l2_cache_entry_size_set; |
| int min_refcount_cache = MIN_REFCOUNT_CACHE_SIZE * s->cluster_size; |
| uint64_t virtual_disk_size = bs->total_sectors * BDRV_SECTOR_SIZE; |
| uint64_t max_l2_entries = DIV_ROUND_UP(virtual_disk_size, s->cluster_size); |
| /* An L2 table is always one cluster in size so the max cache size |
| * should be a multiple of the cluster size. */ |
| uint64_t max_l2_cache = ROUND_UP(max_l2_entries * sizeof(uint64_t), |
| s->cluster_size); |
| |
| combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); |
| l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); |
| refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE); |
| l2_cache_entry_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE); |
| |
| combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); |
| l2_cache_max_setting = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, |
| DEFAULT_L2_CACHE_MAX_SIZE); |
| *refcount_cache_size = qemu_opt_get_size(opts, |
| QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); |
| |
| *l2_cache_entry_size = qemu_opt_get_size( |
| opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size); |
| |
| *l2_cache_size = MIN(max_l2_cache, l2_cache_max_setting); |
| |
| if (combined_cache_size_set) { |
| if (l2_cache_size_set && refcount_cache_size_set) { |
| error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE |
| " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set " |
| "at the same time"); |
| return; |
| } else if (l2_cache_size_set && |
| (l2_cache_max_setting > combined_cache_size)) { |
| error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " |
| QCOW2_OPT_CACHE_SIZE); |
| return; |
| } 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 { |
| /* Assign as much memory as possible to the L2 cache, and |
| * use the remainder for the refcount cache */ |
| if (combined_cache_size >= max_l2_cache + min_refcount_cache) { |
| *l2_cache_size = max_l2_cache; |
| *refcount_cache_size = combined_cache_size - *l2_cache_size; |
| } else { |
| *refcount_cache_size = |
| MIN(combined_cache_size, min_refcount_cache); |
| *l2_cache_size = combined_cache_size - *refcount_cache_size; |
| } |
| } |
| } |
| |
| /* |
| * If the L2 cache is not enough to cover the whole disk then |
| * default to 4KB entries. Smaller entries reduce the cost of |
| * loads and evictions and increase I/O performance. |
| */ |
| if (*l2_cache_size < max_l2_cache && !l2_cache_entry_size_set) { |
| *l2_cache_entry_size = MIN(s->cluster_size, 4096); |
| } |
| |
| /* l2_cache_size and refcount_cache_size are ensured to have at least |
| * their minimum values in qcow2_update_options_prepare() */ |
| |
| if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) || |
| *l2_cache_entry_size > s->cluster_size || |
| !is_power_of_2(*l2_cache_entry_size)) { |
| error_setg(errp, "L2 cache entry size must be a power of two " |
| "between %d and the cluster size (%d)", |
| 1 << MIN_CLUSTER_BITS, s->cluster_size); |
| return; |
| } |
| } |
| |
| 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, |
| DEFAULT_CACHE_CLEAN_INTERVAL); |
| #ifndef CONFIG_LINUX |
| if (r->cache_clean_interval != 0) { |
| error_setg(errp, QCOW2_OPT_CACHE_CLEAN_INTERVAL |
| " not supported on this host"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| #endif |
| if (r->cache_clean_interval > UINT_MAX) { |
| error_setg(errp, "Cache clean interval too big"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| /* lazy-refcounts; flush if going from enabled to disabled */ |
| r->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS, |
| (s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS)); |
| if (r->use_lazy_refcounts && s->qcow_version < 3) { |
| error_setg(errp, "Lazy refcounts require a qcow2 image with at least " |
| "qemu 1.1 compatibility level"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| if (s->use_lazy_refcounts && !r->use_lazy_refcounts) { |
| ret = qcow2_mark_clean(bs); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Failed to disable lazy refcounts"); |
| goto fail; |
| } |
| } |
| |
| /* Overlap check options */ |
| opt_overlap_check = qemu_opt_get(opts, QCOW2_OPT_OVERLAP); |
| opt_overlap_check_template = qemu_opt_get(opts, QCOW2_OPT_OVERLAP_TEMPLATE); |
| if (opt_overlap_check_template && opt_overlap_check && |
| strcmp(opt_overlap_check_template, opt_overlap_check)) |
| { |
| error_setg(errp, "Conflicting values for qcow2 options '" |
| QCOW2_OPT_OVERLAP "' ('%s') and '" QCOW2_OPT_OVERLAP_TEMPLATE |
| "' ('%s')", opt_overlap_check, opt_overlap_check_template); |
| ret = -EINVAL; |
| goto fail; |
| } |
| if (!opt_overlap_check) { |
| opt_overlap_check = opt_overlap_check_template ?: "cached"; |
| } |
| |
| if (!strcmp(opt_overlap_check, "none")) { |
| overlap_check_template = 0; |
| } else if (!strcmp(opt_overlap_check, "constant")) { |
| overlap_check_template = QCOW2_OL_CONSTANT; |
| } else if (!strcmp(opt_overlap_check, "cached")) { |
| overlap_check_template = QCOW2_OL_CACHED; |
| } else if (!strcmp(opt_overlap_check, "all")) { |
| overlap_check_template = QCOW2_OL_ALL; |
| } else { |
| error_setg(errp, "Unsupported value '%s' for qcow2 option " |
| "'overlap-check'. Allowed are any of the following: " |
| "none, constant, cached, all", opt_overlap_check); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| r->overlap_check = 0; |
| for (i = 0; i < QCOW2_OL_MAX_BITNR; i++) { |
| /* overlap-check defines a template bitmask, but every flag may be |
| * overwritten through the associated boolean option */ |
| r->overlap_check |= |
| qemu_opt_get_bool(opts, overlap_bool_option_names[i], |
| overlap_check_template & (1 << i)) << i; |
| } |
| |
| r->discard_passthrough[QCOW2_DISCARD_NEVER] = false; |
| r->discard_passthrough[QCOW2_DISCARD_ALWAYS] = true; |
| r->discard_passthrough[QCOW2_DISCARD_REQUEST] = |
| qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_REQUEST, |
| flags & BDRV_O_UNMAP); |
| r->discard_passthrough[QCOW2_DISCARD_SNAPSHOT] = |
| qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_SNAPSHOT, true); |
| r->discard_passthrough[QCOW2_DISCARD_OTHER] = |
| qemu_opt_get_bool(opts, QCOW2_OPT_DISCARD_OTHER, false); |
| |
| switch (s->crypt_method_header) { |
| case QCOW_CRYPT_NONE: |
| if (encryptfmt) { |
| error_setg(errp, "No encryption in image header, but options " |
| "specified format '%s'", encryptfmt); |
| ret = -EINVAL; |
| goto fail; |
| } |
| break; |
| |
| case QCOW_CRYPT_AES: |
| if (encryptfmt && !g_str_equal(encryptfmt, "aes")) { |
| error_setg(errp, |
| "Header reported 'aes' encryption format but " |
| "options specify '%s'", encryptfmt); |
| ret = -EINVAL; |
| goto fail; |
| } |
| qdict_put_str(encryptopts, "format", "qcow"); |
| r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); |
| break; |
| |
| case QCOW_CRYPT_LUKS: |
| if (encryptfmt && !g_str_equal(encryptfmt, "luks")) { |
| error_setg(errp, |
| "Header reported 'luks' encryption format but " |
| "options specify '%s'", encryptfmt); |
| ret = -EINVAL; |
| goto fail; |
| } |
| qdict_put_str(encryptopts, "format", "luks"); |
| r->crypto_opts = block_crypto_open_opts_init(encryptopts, errp); |
| 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: |
| qobject_unref(encryptopts); |
| qemu_opts_del(opts); |
| opts = NULL; |
| return ret; |
| } |
| |
| static void qcow2_update_options_commit(BlockDriverState *bs, |
| Qcow2ReopenState *r) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| int i; |
| |
| if (s->l2_table_cache) { |
| qcow2_cache_destroy(s->l2_table_cache); |
| } |
| if (s->refcount_block_cache) { |
| qcow2_cache_destroy(s->refcount_block_cache); |
| } |
| s->l2_table_cache = r->l2_table_cache; |
| s->refcount_block_cache = r->refcount_block_cache; |
| s->l2_slice_size = r->l2_slice_size; |
| |
| s->overlap_check = r->overlap_check; |
| s->use_lazy_refcounts = r->use_lazy_refcounts; |
| |
| for (i = 0; i < QCOW2_DISCARD_MAX; i++) { |
| s->discard_passthrough[i] = r->discard_passthrough[i]; |
| } |
| |
| if (s->cache_clean_interval != r->cache_clean_interval) { |
| cache_clean_timer_del(bs); |
| s->cache_clean_interval = r->cache_clean_interval; |
| cache_clean_timer_init(bs, bdrv_get_aio_context(bs)); |
| } |
| |
| qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); |
| s->crypto_opts = r->crypto_opts; |
| } |
| |
| static void qcow2_update_options_abort(BlockDriverState *bs, |
| Qcow2ReopenState *r) |
| { |
| if (r->l2_table_cache) { |
| qcow2_cache_destroy(r->l2_table_cache); |
| } |
| if (r->refcount_block_cache) { |
| qcow2_cache_destroy(r->refcount_block_cache); |
| } |
| qapi_free_QCryptoBlockOpenOptions(r->crypto_opts); |
| } |
| |
| static int qcow2_update_options(BlockDriverState *bs, QDict *options, |
| int flags, Error **errp) |
| { |
| Qcow2ReopenState r = {}; |
| int ret; |
| |
| ret = qcow2_update_options_prepare(bs, &r, options, flags, errp); |
| if (ret >= 0) { |
| qcow2_update_options_commit(bs, &r); |
| } else { |
| qcow2_update_options_abort(bs, &r); |
| } |
| |
| return ret; |
| } |
| |
| /* Called with s->lock held. */ |
| static int coroutine_fn 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; |
| } |
| header.magic = be32_to_cpu(header.magic); |
| header.version = be32_to_cpu(header.version); |
| header.backing_file_offset = be64_to_cpu(header.backing_file_offset); |
| header.backing_file_size = be32_to_cpu(header.backing_file_size); |
| header.size = be64_to_cpu(header.size); |
| header.cluster_bits = be32_to_cpu(header.cluster_bits); |
| header.crypt_method = be32_to_cpu(header.crypt_method); |
| header.l1_table_offset = be64_to_cpu(header.l1_table_offset); |
| header.l1_size = be32_to_cpu(header.l1_size); |
| header.refcount_table_offset = be64_to_cpu(header.refcount_table_offset); |
| header.refcount_table_clusters = |
| be32_to_cpu(header.refcount_table_clusters); |
| header.snapshots_offset = be64_to_cpu(header.snapshots_offset); |
| header.nb_snapshots = be32_to_cpu(header.nb_snapshots); |
| |
| if (header.magic != QCOW_MAGIC) { |
| error_setg(errp, "Image is not in qcow2 format"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| if (header.version < 2 || header.version > 3) { |
| error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version); |
| ret = -ENOTSUP; |
| goto fail; |
| } |
| |
| s->qcow_version = header.version; |
| |
| /* Initialise cluster size */ |
| if (header.cluster_bits < MIN_CLUSTER_BITS || |
| header.cluster_bits > MAX_CLUSTER_BITS) { |
| error_setg(errp, "Unsupported cluster size: 2^%" PRIu32, |
| header.cluster_bits); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| s->cluster_bits = header.cluster_bits; |
| s->cluster_size = 1 << s->cluster_bits; |
| |
| /* Initialise version 3 header fields */ |
| if (header.version == 2) { |
| header.incompatible_features = 0; |
| header.compatible_features = 0; |
| header.autoclear_features = 0; |
| header.refcount_order = 4; |
| header.header_length = 72; |
| } else { |
| header.incompatible_features = |
| be64_to_cpu(header.incompatible_features); |
| header.compatible_features = be64_to_cpu(header.compatible_features); |
| header.autoclear_features = be64_to_cpu(header.autoclear_features); |
| header.refcount_order = be32_to_cpu(header.refcount_order); |
| header.header_length = be32_to_cpu(header.header_length); |
| |
| if (header.header_length < 104) { |
| error_setg(errp, "qcow2 header too short"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| } |
| |
| if (header.header_length > s->cluster_size) { |
| error_setg(errp, "qcow2 header exceeds cluster size"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| if (header.header_length > sizeof(header)) { |
| s->unknown_header_fields_size = header.header_length - sizeof(header); |
| s->unknown_header_fields = g_malloc(s->unknown_header_fields_size); |
| ret = bdrv_pread(bs->file, sizeof(header), s->unknown_header_fields, |
| s->unknown_header_fields_size); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not read unknown qcow2 header " |
| "fields"); |
| goto fail; |
| } |
| } |
| |
| if (header.backing_file_offset > s->cluster_size) { |
| error_setg(errp, "Invalid backing file offset"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| if (header.backing_file_offset) { |
| ext_end = header.backing_file_offset; |
| } else { |
| ext_end = 1 << header.cluster_bits; |
| } |
| |
| /* Handle feature bits */ |
| s->incompatible_features = header.incompatible_features; |
| s->compatible_features = header.compatible_features; |
| s->autoclear_features = header.autoclear_features; |
| |
| 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 / BDRV_SECTOR_SIZE; |
| s->csize_shift = (62 - (s->cluster_bits - 8)); |
| s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; |
| s->cluster_offset_mask = (1LL << s->csize_shift) - 1; |
| |
| s->refcount_table_offset = header.refcount_table_offset; |
| s->refcount_table_size = |
| header.refcount_table_clusters << (s->cluster_bits - 3); |
| |
| if (header.refcount_table_clusters == 0 && !(flags & BDRV_O_CHECK)) { |
| error_setg(errp, "Image does not contain a reference count table"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| ret = qcow2_validate_table(bs, s->refcount_table_offset, |
| header.refcount_table_clusters, |
| s->cluster_size, QCOW_MAX_REFTABLE_SIZE, |
| "Reference count table", errp); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| if (!(flags & BDRV_O_CHECK)) { |
| /* |
| * The total size in bytes of the snapshot table is checked in |
| * qcow2_read_snapshots() because the size of each snapshot is |
| * variable and we don't know it yet. |
| * Here we only check the offset and number of snapshots. |
| */ |
| ret = qcow2_validate_table(bs, header.snapshots_offset, |
| header.nb_snapshots, |
| sizeof(QCowSnapshotHeader), |
| sizeof(QCowSnapshotHeader) * |
| QCOW_MAX_SNAPSHOTS, |
| "Snapshot table", errp); |
| if (ret < 0) { |
| goto fail; |
| } |
| } |
| |
| /* read the level 1 table */ |
| ret = qcow2_validate_table(bs, header.l1_table_offset, |
| header.l1_size, sizeof(uint64_t), |
| QCOW_MAX_L1_SIZE, "Active L1 table", errp); |
| if (ret < 0) { |
| goto fail; |
| } |
| s->l1_size = header.l1_size; |
| s->l1_table_offset = header.l1_table_offset; |
| |
| l1_vm_state_index = size_to_l1(s, header.size); |
| if (l1_vm_state_index > INT_MAX) { |
| error_setg(errp, "Image is too big"); |
| ret = -EFBIG; |
| goto fail; |
| } |
| s->l1_vm_state_index = l1_vm_state_index; |
| |
| /* the L1 table must contain at least enough entries to put |
| header.size bytes */ |
| if (s->l1_size < s->l1_vm_state_index) { |
| error_setg(errp, "L1 table is too small"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| if (s->l1_size > 0) { |
| s->l1_table = qemu_try_blockalign(bs->file->bs, |
| s->l1_size * sizeof(uint64_t)); |
| 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++) { |
| s->l1_table[i] = be64_to_cpu(s->l1_table[i]); |
| } |
| } |
| |
| /* Parse driver-specific options */ |
| ret = qcow2_update_options(bs, options, flags, errp); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| s->flags = flags; |
| |
| ret = qcow2_refcount_init(bs); |
| if (ret != 0) { |
| error_setg_errno(errp, -ret, "Could not initialize refcount handling"); |
| goto fail; |
| } |
| |
| QLIST_INIT(&s->cluster_allocs); |
| QTAILQ_INIT(&s->discards); |
| |
| /* read qcow2 extensions */ |
| if (qcow2_read_extensions(bs, header.header_length, ext_end, NULL, |
| flags, &update_header, &local_err)) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| /* Open external data file */ |
| s->data_file = bdrv_open_child(NULL, options, "data-file", bs, &child_file, |
| true, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| if (s->incompatible_features & QCOW2_INCOMPAT_DATA_FILE) { |
| if (!s->data_file && s->image_data_file) { |
| s->data_file = bdrv_open_child(s->image_data_file, options, |
| "data-file", bs, &child_file, |
| false, errp); |
| if (!s->data_file) { |
| ret = -EINVAL; |
| goto fail; |
| } |
| } |
| if (!s->data_file) { |
| error_setg(errp, "'data-file' is required for this image"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| } else { |
| if (s->data_file) { |
| error_setg(errp, "'data-file' can only be set for images with an " |
| "external data file"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| s->data_file = bs->file; |
| |
| if (data_file_is_raw(bs)) { |
| error_setg(errp, "data-file-raw requires a data file"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| } |
| |
| /* qcow2_read_extension may have set up the crypto context |
| * if the crypt method needs a header region, some methods |
| * don't need header extensions, so must check here |
| */ |
| if (s->crypt_method_header && !s->crypto) { |
| if (s->crypt_method_header == QCOW_CRYPT_AES) { |
| unsigned int cflags = 0; |
| if (flags & BDRV_O_NO_IO) { |
| cflags |= QCRYPTO_BLOCK_OPEN_NO_IO; |
| } |
| s->crypto = qcrypto_block_open(s->crypto_opts, "encrypt.", |
| NULL, NULL, cflags, |
| QCOW2_MAX_THREADS, errp); |
| if (!s->crypto) { |
| ret = -EINVAL; |
| goto fail; |
| } |
| } else if (!(flags & BDRV_O_NO_IO)) { |
| error_setg(errp, "Missing CRYPTO header for crypt method %d", |
| s->crypt_method_header); |
| ret = -EINVAL; |
| goto fail; |
| } |
| } |
| |
| /* read the backing file name */ |
| if (header.backing_file_offset != 0) { |
| len = header.backing_file_size; |
| if (len > MIN(1023, s->cluster_size - header.backing_file_offset) || |
| len >= sizeof(bs->backing_file)) { |
| error_setg(errp, "Backing file name too long"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| ret = bdrv_pread(bs->file, header.backing_file_offset, |
| bs->auto_backing_file, len); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not read backing file name"); |
| goto fail; |
| } |
| bs->auto_backing_file[len] = '\0'; |
| pstrcpy(bs->backing_file, sizeof(bs->backing_file), |
| bs->auto_backing_file); |
| s->image_backing_file = g_strdup(bs->auto_backing_file); |
| } |
| |
| /* |
| * Internal snapshots; skip reading them in check mode, because |
| * we do not need them then, and we do not want to abort because |
| * of a broken table. |
| */ |
| if (!(flags & BDRV_O_CHECK)) { |
| s->snapshots_offset = header.snapshots_offset; |
| s->nb_snapshots = header.nb_snapshots; |
| |
| ret = qcow2_read_snapshots(bs, errp); |
| if (ret < 0) { |
| goto fail; |
| } |
| } |
| |
| /* Clear unknown autoclear feature bits */ |
| update_header |= s->autoclear_features & ~QCOW2_AUTOCLEAR_MASK; |
| update_header = |
| update_header && !bs->read_only && !(flags & BDRV_O_INACTIVE); |
| if (update_header) { |
| s->autoclear_features &= QCOW2_AUTOCLEAR_MASK; |
| } |
| |
| /* == Handle persistent dirty bitmaps == |
| * |
| * We want load dirty bitmaps in three cases: |
| * |
| * 1. Normal open of the disk in active mode, not related to invalidation |
| * after migration. |
| * |
| * 2. Invalidation of the target vm after pre-copy phase of migration, if |
| * bitmaps are _not_ migrating through migration channel, i.e. |
| * 'dirty-bitmaps' capability is disabled. |
| * |
| * 3. Invalidation of source vm after failed or canceled migration. |
| * This is a very interesting case. There are two possible types of |
| * bitmaps: |
| * |
| * A. Stored on inactivation and removed. They should be loaded from the |
| * image. |
| * |
| * B. Not stored: not-persistent bitmaps and bitmaps, migrated through |
| * the migration channel (with dirty-bitmaps capability). |
| * |
| * On the other hand, there are two possible sub-cases: |
| * |
| * 3.1 disk was changed by somebody else while were inactive. In this |
| * case all in-RAM dirty bitmaps (both persistent and not) are |
| * definitely invalid. And we don't have any method to determine |
| * this. |
| * |
| * Simple and safe thing is to just drop all the bitmaps of type B on |
| * inactivation. But in this case we lose bitmaps in valid 4.2 case. |
| * |
| * On the other hand, resuming source vm, if disk was already changed |
| * is a bad thing anyway: not only bitmaps, the whole vm state is |
| * out of sync with disk. |
| * |
| * This means, that user or management tool, who for some reason |
| * decided to resume source vm, after disk was already changed by |
| * target vm, should at least drop all dirty bitmaps by hand. |
| * |
| * So, we can ignore this case for now, but TODO: "generation" |
| * extension for qcow2, to determine, that image was changed after |
| * last inactivation. And if it is changed, we will drop (or at least |
| * mark as 'invalid' all the bitmaps of type B, both persistent |
| * and not). |
| * |
| * 3.2 disk was _not_ changed while were inactive. Bitmaps may be saved |
| * to disk ('dirty-bitmaps' capability disabled), or not saved |
| * ('dirty-bitmaps' capability enabled), but we don't need to care |
| * of: let's load bitmaps as always: stored bitmaps will be loaded, |
| * and not stored has flag IN_USE=1 in the image and will be skipped |
| * on loading. |
| * |
| * One remaining possible case when we don't want load bitmaps: |
| * |
| * 4. Open disk in inactive mode in target vm (bitmaps are migrating or |
| * will be loaded on invalidation, no needs try loading them before) |
| */ |
| |
| if (!(bdrv_get_flags(bs) & BDRV_O_INACTIVE)) { |
| /* It's case 1, 2 or 3.2. Or 3.1 which is BUG in management layer. */ |
| bool header_updated = qcow2_load_dirty_bitmaps(bs, &local_err); |
| if (local_err != NULL) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| update_header = update_header && !header_updated; |
| } |
| |
| if (update_header) { |
| ret = qcow2_update_header(bs); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not update qcow2 header"); |
| goto fail; |
| } |
| } |
| |
| bs->supported_zero_flags = header.version >= 3 ? |
| BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK : 0; |
| |
| /* 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_co_check_locked(bs, &result, |
| BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); |
| if (ret < 0 || result.check_errors) { |
| if (ret >= 0) { |
| ret = -EIO; |
| } |
| error_setg_errno(errp, -ret, "Could not repair dirty image"); |
| goto fail; |
| } |
| } |
| |
| #ifdef DEBUG_ALLOC |
| { |
| BdrvCheckResult result = {0}; |
| qcow2_check_refcounts(bs, &result, 0); |
| } |
| #endif |
| |
| qemu_co_queue_init(&s->thread_task_queue); |
| |
| return ret; |
| |
| fail: |
| g_free(s->image_data_file); |
| if (has_data_file(bs)) { |
| bdrv_unref_child(bs, s->data_file); |
| s->data_file = NULL; |
| } |
| g_free(s->unknown_header_fields); |
| cleanup_unknown_header_ext(bs); |
| qcow2_free_snapshots(bs); |
| qcow2_refcount_close(bs); |
| qemu_vfree(s->l1_table); |
| /* else pre-write overlap checks in cache_destroy may crash */ |
| s->l1_table = NULL; |
| cache_clean_timer_del(bs); |
| if (s->l2_table_cache) { |
| qcow2_cache_destroy(s->l2_table_cache); |
| } |
| if (s->refcount_block_cache) { |
| qcow2_cache_destroy(s->refcount_block_cache); |
| } |
| qcrypto_block_free(s->crypto); |
| qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); |
| return ret; |
| } |
| |
| typedef struct QCow2OpenCo { |
| BlockDriverState *bs; |
| QDict *options; |
| int flags; |
| Error **errp; |
| int ret; |
| } QCow2OpenCo; |
| |
| static void coroutine_fn qcow2_open_entry(void *opaque) |
| { |
| QCow2OpenCo *qoc = opaque; |
| BDRVQcow2State *s = qoc->bs->opaque; |
| |
| qemu_co_mutex_lock(&s->lock); |
| qoc->ret = qcow2_do_open(qoc->bs, qoc->options, qoc->flags, qoc->errp); |
| qemu_co_mutex_unlock(&s->lock); |
| } |
| |
| static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, |
| Error **errp) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| QCow2OpenCo qoc = { |
| .bs = bs, |
| .options = options, |
| .flags = flags, |
| .errp = errp, |
| .ret = -EINPROGRESS |
| }; |
| |
| bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, |
| false, errp); |
| if (!bs->file) { |
| return -EINVAL; |
| } |
| |
| /* Initialise locks */ |
| qemu_co_mutex_init(&s->lock); |
| |
| if (qemu_in_coroutine()) { |
| /* From bdrv_co_create. */ |
| qcow2_open_entry(&qoc); |
| } else { |
| assert(qemu_get_current_aio_context() == qemu_get_aio_context()); |
| qemu_coroutine_enter(qemu_coroutine_create(qcow2_open_entry, &qoc)); |
| BDRV_POLL_WHILE(bs, qoc.ret == -EINPROGRESS); |
| } |
| return qoc.ret; |
| } |
| |
| static void qcow2_refresh_limits(BlockDriverState *bs, Error **errp) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| |
| if (bs->encrypted) { |
| /* Encryption works on a sector granularity */ |
| bs->bl.request_alignment = qcrypto_block_get_sector_size(s->crypto); |
| } |
| bs->bl.pwrite_zeroes_alignment = s->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_commit_post(BDRVReopenState *state) |
| { |
| if (state->flags & BDRV_O_RDWR) { |
| Error *local_err = NULL; |
| |
| if (qcow2_reopen_bitmaps_rw(state->bs, &local_err) < 0) { |
| /* |
| * This is not fatal, bitmaps just left read-only, so all following |
| * writes will fail. User can remove read-only bitmaps to unblock |
| * writes or retry reopen. |
| */ |
| error_reportf_err(local_err, |
| "%s: Failed to make dirty bitmaps writable: ", |
| bdrv_get_node_name(state->bs)); |
| } |
| } |
| } |
| |
| static void qcow2_reopen_abort(BDRVReopenState *state) |
| { |
| 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; |
| unsigned int bytes; |
| int ret, status = 0; |
| |
| qemu_co_mutex_lock(&s->lock); |
| |
| if (!s->metadata_preallocation_checked) { |
| ret = qcow2_detect_metadata_preallocation(bs); |
| s->metadata_preallocation = (ret == 1); |
| s->metadata_preallocation_checked = true; |
| } |
| |
| bytes = MIN(INT_MAX, count); |
| ret = qcow2_get_cluster_offset(bs, offset, &bytes, &cluster_offset); |
| qemu_co_mutex_unlock(&s->lock); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| *pnum = bytes; |
| |
| if ((ret == QCOW2_CLUSTER_NORMAL || ret == QCOW2_CLUSTER_ZERO_ALLOC) && |
| !s->crypto) { |
| *map = cluster_offset | offset_into_cluster(s, offset); |
| *file = s->data_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; |
| } |
| if (s->metadata_preallocation && (status & BDRV_BLOCK_DATA) && |
| (status & BDRV_BLOCK_OFFSET_VALID)) |
| { |
| status |= BDRV_BLOCK_RECURSE; |
| } |
| return status; |
| } |
| |
| static coroutine_fn int qcow2_handle_l2meta(BlockDriverState *bs, |
| QCowL2Meta **pl2meta, |
| bool link_l2) |
| { |
| int ret = 0; |
| QCowL2Meta *l2meta = *pl2meta; |
| |
| while (l2meta != NULL) { |
| QCowL2Meta *next; |
| |
| if (link_l2) { |
| ret = qcow2_alloc_cluster_link_l2(bs, l2meta); |
| if (ret) { |
| goto out; |
| } |
| } else { |
| qcow2_alloc_cluster_abort(bs, l2meta); |
| } |
| |
| /* Take the request off the list of running requests */ |
| 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; |
| } |
| out: |
| *pl2meta = l2meta; |
| return ret; |
| } |
| |
| static coroutine_fn int |
| qcow2_co_preadv_encrypted(BlockDriverState *bs, |
| uint64_t file_cluster_offset, |
| uint64_t offset, |
| uint64_t bytes, |
| QEMUIOVector *qiov, |
| uint64_t qiov_offset) |
| { |
| int ret; |
| BDRVQcow2State *s = bs->opaque; |
| uint8_t *buf; |
| |
| assert(bs->encrypted && s->crypto); |
| assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
| |
| /* |
| * For encrypted images, read everything into a temporary |
| * contiguous buffer on which the AES functions can work. |
| * Also, decryption in a separate buffer is better as it |
| * prevents the guest from learning information about the |
| * encrypted nature of the virtual disk. |
| */ |
| |
| buf = qemu_try_blockalign(s->data_file->bs, bytes); |
| if (buf == NULL) { |
| return -ENOMEM; |
| } |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
| ret = bdrv_co_pread(s->data_file, |
| file_cluster_offset + offset_into_cluster(s, offset), |
| bytes, buf, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| if (qcow2_co_decrypt(bs, |
| file_cluster_offset + offset_into_cluster(s, offset), |
| offset, buf, bytes) < 0) |
| { |
| ret = -EIO; |
| goto fail; |
| } |
| qemu_iovec_from_buf(qiov, qiov_offset, buf, bytes); |
| |
| fail: |
| qemu_vfree(buf); |
| |
| return ret; |
| } |
| |
| typedef struct Qcow2AioTask { |
| AioTask task; |
| |
| BlockDriverState *bs; |
| QCow2ClusterType cluster_type; /* only for read */ |
| uint64_t file_cluster_offset; |
| uint64_t offset; |
| uint64_t bytes; |
| QEMUIOVector *qiov; |
| uint64_t qiov_offset; |
| QCowL2Meta *l2meta; /* only for write */ |
| } Qcow2AioTask; |
| |
| static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task); |
| static coroutine_fn int qcow2_add_task(BlockDriverState *bs, |
| AioTaskPool *pool, |
| AioTaskFunc func, |
| QCow2ClusterType cluster_type, |
| uint64_t file_cluster_offset, |
| uint64_t offset, |
| uint64_t bytes, |
| QEMUIOVector *qiov, |
| size_t qiov_offset, |
| QCowL2Meta *l2meta) |
| { |
| Qcow2AioTask local_task; |
| Qcow2AioTask *task = pool ? g_new(Qcow2AioTask, 1) : &local_task; |
| |
| *task = (Qcow2AioTask) { |
| .task.func = func, |
| .bs = bs, |
| .cluster_type = cluster_type, |
| .qiov = qiov, |
| .file_cluster_offset = file_cluster_offset, |
| .offset = offset, |
| .bytes = bytes, |
| .qiov_offset = qiov_offset, |
| .l2meta = l2meta, |
| }; |
| |
| trace_qcow2_add_task(qemu_coroutine_self(), bs, pool, |
| func == qcow2_co_preadv_task_entry ? "read" : "write", |
| cluster_type, file_cluster_offset, offset, bytes, |
| qiov, qiov_offset); |
| |
| if (!pool) { |
| return func(&task->task); |
| } |
| |
| aio_task_pool_start_task(pool, &task->task); |
| |
| return 0; |
| } |
| |
| static coroutine_fn int qcow2_co_preadv_task(BlockDriverState *bs, |
| QCow2ClusterType cluster_type, |
| uint64_t file_cluster_offset, |
| uint64_t offset, uint64_t bytes, |
| QEMUIOVector *qiov, |
| size_t qiov_offset) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| int offset_in_cluster = offset_into_cluster(s, offset); |
| |
| switch (cluster_type) { |
| case QCOW2_CLUSTER_ZERO_PLAIN: |
| case QCOW2_CLUSTER_ZERO_ALLOC: |
| /* Both zero types are handled in qcow2_co_preadv_part */ |
| g_assert_not_reached(); |
| |
| case QCOW2_CLUSTER_UNALLOCATED: |
| assert(bs->backing); /* otherwise handled in qcow2_co_preadv_part */ |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO); |
| return bdrv_co_preadv_part(bs->backing, offset, bytes, |
| qiov, qiov_offset, 0); |
| |
| case QCOW2_CLUSTER_COMPRESSED: |
| return qcow2_co_preadv_compressed(bs, file_cluster_offset, |
| offset, bytes, qiov, qiov_offset); |
| |
| case QCOW2_CLUSTER_NORMAL: |
| assert(offset_into_cluster(s, file_cluster_offset) == 0); |
| if (bs->encrypted) { |
| return qcow2_co_preadv_encrypted(bs, file_cluster_offset, |
| offset, bytes, qiov, qiov_offset); |
| } |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO); |
| return bdrv_co_preadv_part(s->data_file, |
| file_cluster_offset + offset_in_cluster, |
| bytes, qiov, qiov_offset, 0); |
| |
| default: |
| g_assert_not_reached(); |
| } |
| |
| g_assert_not_reached(); |
| } |
| |
| static coroutine_fn int qcow2_co_preadv_task_entry(AioTask *task) |
| { |
| Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); |
| |
| assert(!t->l2meta); |
| |
| return qcow2_co_preadv_task(t->bs, t->cluster_type, t->file_cluster_offset, |
| t->offset, t->bytes, t->qiov, t->qiov_offset); |
| } |
| |
| static coroutine_fn int qcow2_co_preadv_part(BlockDriverState *bs, |
| uint64_t offset, uint64_t bytes, |
| QEMUIOVector *qiov, |
| size_t qiov_offset, int flags) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| int ret = 0; |
| unsigned int cur_bytes; /* number of bytes in current iteration */ |
| uint64_t cluster_offset = 0; |
| AioTaskPool *aio = NULL; |
| |
| while (bytes != 0 && aio_task_pool_status(aio) == 0) { |
| /* prepare next request */ |
| cur_bytes = MIN(bytes, INT_MAX); |
| if (s->crypto) { |
| cur_bytes = MIN(cur_bytes, |
| QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
| } |
| |
| qemu_co_mutex_lock(&s->lock); |
| ret = qcow2_get_cluster_offset(bs, offset, &cur_bytes, &cluster_offset); |
| qemu_co_mutex_unlock(&s->lock); |
| if (ret < 0) { |
| goto out; |
| } |
| |
| if (ret == QCOW2_CLUSTER_ZERO_PLAIN || |
| ret == QCOW2_CLUSTER_ZERO_ALLOC || |
| (ret == QCOW2_CLUSTER_UNALLOCATED && !bs->backing)) |
| { |
| qemu_iovec_memset(qiov, qiov_offset, 0, cur_bytes); |
| } else { |
| if (!aio && cur_bytes != bytes) { |
| aio = aio_task_pool_new(QCOW2_MAX_WORKERS); |
| } |
| ret = qcow2_add_task(bs, aio, qcow2_co_preadv_task_entry, ret, |
| cluster_offset, offset, cur_bytes, |
| qiov, qiov_offset, NULL); |
| if (ret < 0) { |
| goto out; |
| } |
| } |
| |
| bytes -= cur_bytes; |
| offset += cur_bytes; |
| qiov_offset += cur_bytes; |
| } |
| |
| out: |
| if (aio) { |
| aio_task_pool_wait_all(aio); |
| if (ret == 0) { |
| ret = aio_task_pool_status(aio); |
| } |
| g_free(aio); |
| } |
| |
| return ret; |
| } |
| |
| /* Check if it's possible to merge a write request with the writing of |
| * the data from the COW regions */ |
| static bool merge_cow(uint64_t offset, unsigned bytes, |
| QEMUIOVector *qiov, size_t qiov_offset, |
| QCowL2Meta *l2meta) |
| { |
| QCowL2Meta *m; |
| |
| for (m = l2meta; m != NULL; m = m->next) { |
| /* If both COW regions are empty then there's nothing to merge */ |
| if (m->cow_start.nb_bytes == 0 && m->cow_end.nb_bytes == 0) { |
| continue; |
| } |
| |
| /* If COW regions are handled already, skip this too */ |
| if (m->skip_cow) { |
| continue; |
| } |
| |
| /* The 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 (qemu_iovec_subvec_niov(qiov, qiov_offset, bytes) > IOV_MAX - 2) { |
| continue; |
| } |
| |
| m->data_qiov = qiov; |
| m->data_qiov_offset = qiov_offset; |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static bool is_unallocated(BlockDriverState *bs, int64_t offset, int64_t bytes) |
| { |
| int64_t nr; |
| return !bytes || |
| (!bdrv_is_allocated_above(bs, NULL, false, offset, bytes, &nr) && |
| nr == bytes); |
| } |
| |
| static bool is_zero_cow(BlockDriverState *bs, QCowL2Meta *m) |
| { |
| /* |
| * This check is designed for optimization shortcut so it must be |
| * efficient. |
| * Instead of is_zero(), use is_unallocated() as it is faster (but not |
| * as accurate and can result in false negatives). |
| */ |
| return is_unallocated(bs, m->offset + m->cow_start.offset, |
| m->cow_start.nb_bytes) && |
| is_unallocated(bs, m->offset + m->cow_end.offset, |
| m->cow_end.nb_bytes); |
| } |
| |
| static int handle_alloc_space(BlockDriverState *bs, QCowL2Meta *l2meta) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| QCowL2Meta *m; |
| |
| if (!(s->data_file->bs->supported_zero_flags & BDRV_REQ_NO_FALLBACK)) { |
| return 0; |
| } |
| |
| if (bs->encrypted) { |
| return 0; |
| } |
| |
| for (m = l2meta; m != NULL; m = m->next) { |
| int ret; |
| |
| if (!m->cow_start.nb_bytes && !m->cow_end.nb_bytes) { |
| continue; |
| } |
| |
| if (!is_zero_cow(bs, m)) { |
| continue; |
| } |
| |
| /* |
| * instead of writing zero COW buffers, |
| * efficiently zero out the whole clusters |
| */ |
| |
| ret = qcow2_pre_write_overlap_check(bs, 0, m->alloc_offset, |
| m->nb_clusters * s->cluster_size, |
| true); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC_SPACE); |
| ret = bdrv_co_pwrite_zeroes(s->data_file, m->alloc_offset, |
| m->nb_clusters * s->cluster_size, |
| BDRV_REQ_NO_FALLBACK); |
| if (ret < 0) { |
| if (ret != -ENOTSUP && ret != -EAGAIN) { |
| return ret; |
| } |
| continue; |
| } |
| |
| trace_qcow2_skip_cow(qemu_coroutine_self(), m->offset, m->nb_clusters); |
| m->skip_cow = true; |
| } |
| return 0; |
| } |
| |
| /* |
| * qcow2_co_pwritev_task |
| * Called with s->lock unlocked |
| * l2meta - if not NULL, qcow2_co_pwritev_task() will consume it. Caller must |
| * not use it somehow after qcow2_co_pwritev_task() call |
| */ |
| static coroutine_fn int qcow2_co_pwritev_task(BlockDriverState *bs, |
| uint64_t file_cluster_offset, |
| uint64_t offset, uint64_t bytes, |
| QEMUIOVector *qiov, |
| uint64_t qiov_offset, |
| QCowL2Meta *l2meta) |
| { |
| int ret; |
| BDRVQcow2State *s = bs->opaque; |
| void *crypt_buf = NULL; |
| int offset_in_cluster = offset_into_cluster(s, offset); |
| QEMUIOVector encrypted_qiov; |
| |
| if (bs->encrypted) { |
| assert(s->crypto); |
| assert(bytes <= QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); |
| crypt_buf = qemu_try_blockalign(bs->file->bs, bytes); |
| if (crypt_buf == NULL) { |
| ret = -ENOMEM; |
| goto out_unlocked; |
| } |
| qemu_iovec_to_buf(qiov, qiov_offset, crypt_buf, bytes); |
| |
| if (qcow2_co_encrypt(bs, file_cluster_offset + offset_in_cluster, |
| offset, crypt_buf, bytes) < 0) |
| { |
| ret = -EIO; |
| goto out_unlocked; |
| } |
| |
| qemu_iovec_init_buf(&encrypted_qiov, crypt_buf, bytes); |
| qiov = &encrypted_qiov; |
| qiov_offset = 0; |
| } |
| |
| /* Try to efficiently initialize the physical space with zeroes */ |
| ret = handle_alloc_space(bs, l2meta); |
| if (ret < 0) { |
| goto out_unlocked; |
| } |
| |
| /* |
| * If we need to do COW, check if it's possible to merge the |
| * writing of the guest data together with that of the COW regions. |
| * If it's not possible (or not necessary) then write the |
| * guest data now. |
| */ |
| if (!merge_cow(offset, bytes, qiov, qiov_offset, l2meta)) { |
| BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO); |
| trace_qcow2_writev_data(qemu_coroutine_self(), |
| file_cluster_offset + offset_in_cluster); |
| ret = bdrv_co_pwritev_part(s->data_file, |
| file_cluster_offset + offset_in_cluster, |
| bytes, qiov, qiov_offset, 0); |
| if (ret < 0) { |
| goto out_unlocked; |
| } |
| } |
| |
| qemu_co_mutex_lock(&s->lock); |
| |
| ret = qcow2_handle_l2meta(bs, &l2meta, true); |
| goto out_locked; |
| |
| out_unlocked: |
| qemu_co_mutex_lock(&s->lock); |
| |
| out_locked: |
| qcow2_handle_l2meta(bs, &l2meta, false); |
| qemu_co_mutex_unlock(&s->lock); |
| |
| qemu_vfree(crypt_buf); |
| |
| return ret; |
| } |
| |
| static coroutine_fn int qcow2_co_pwritev_task_entry(AioTask *task) |
| { |
| Qcow2AioTask *t = container_of(task, Qcow2AioTask, task); |
| |
| assert(!t->cluster_type); |
| |
| return qcow2_co_pwritev_task(t->bs, t->file_cluster_offset, |
| t->offset, t->bytes, t->qiov, t->qiov_offset, |
| t->l2meta); |
| } |
| |
| static coroutine_fn int qcow2_co_pwritev_part( |
| BlockDriverState *bs, uint64_t offset, uint64_t bytes, |
| QEMUIOVector *qiov, size_t qiov_offset, 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; |
| QCowL2Meta *l2meta = NULL; |
| AioTaskPool *aio = NULL; |
| |
| trace_qcow2_writev_start_req(qemu_coroutine_self(), offset, bytes); |
| |
| while (bytes != 0 && aio_task_pool_status(aio) == 0) { |
| |
| l2meta = NULL; |
| |
| trace_qcow2_writev_start_part(qemu_coroutine_self()); |
| offset_in_cluster = offset_into_cluster(s, offset); |
| cur_bytes = MIN(bytes, INT_MAX); |
| if (bs->encrypted) { |
| cur_bytes = MIN(cur_bytes, |
| QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size |
| - offset_in_cluster); |
| } |
| |
| qemu_co_mutex_lock(&s->lock); |
| |
| ret = qcow2_alloc_cluster_offset(bs, offset, &cur_bytes, |
| &cluster_offset, &l2meta); |
| if (ret < 0) { |
| goto out_locked; |
| } |
| |
| assert(offset_into_cluster(s, cluster_offset) == 0); |
| |
| ret = qcow2_pre_write_overlap_check(bs, 0, |
| cluster_offset + offset_in_cluster, |
| cur_bytes, true); |
| if (ret < 0) { |
| goto out_locked; |
| } |
| |
| qemu_co_mutex_unlock(&s->lock); |
| |
| if (!aio && cur_bytes != bytes) { |
| aio = aio_task_pool_new(QCOW2_MAX_WORKERS); |
| } |
| ret = qcow2_add_task(bs, aio, qcow2_co_pwritev_task_entry, 0, |
| cluster_offset, offset, cur_bytes, |
| qiov, qiov_offset, l2meta); |
| l2meta = NULL; /* l2meta is consumed by qcow2_co_pwritev_task() */ |
| if (ret < 0) { |
| goto fail_nometa; |
| } |
| |
| bytes -= cur_bytes; |
| offset += cur_bytes; |
| qiov_offset += cur_bytes; |
| trace_qcow2_writev_done_part(qemu_coroutine_self(), cur_bytes); |
| } |
| ret = 0; |
| |
| qemu_co_mutex_lock(&s->lock); |
| |
| out_locked: |
| qcow2_handle_l2meta(bs, &l2meta, false); |
| |
| qemu_co_mutex_unlock(&s->lock); |
| |
| fail_nometa: |
| if (aio) { |
| aio_task_pool_wait_all(aio); |
| if (ret == 0) { |
| ret = aio_task_pool_status(aio); |
| } |
| g_free(aio); |
| } |
| |
| trace_qcow2_writev_done_req(qemu_coroutine_self(), ret); |
| |
| return ret; |
| } |
| |
| static int qcow2_inactivate(BlockDriverState *bs) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| int ret, result = 0; |
| Error *local_err = NULL; |
| |
| qcow2_store_persistent_dirty_bitmaps(bs, true, &local_err); |
| if (local_err != NULL) { |
| result = -EINVAL; |
| error_reportf_err(local_err, "Lost persistent bitmaps during " |
| "inactivation of node '%s': ", |
| bdrv_get_device_or_node_name(bs)); |
| } |
| |
| ret = qcow2_cache_flush(bs, s->l2_table_cache); |
| if (ret) { |
| result = ret; |
| error_report("Failed to flush the L2 table cache: %s", |
| strerror(-ret)); |
| } |
| |
| ret = qcow2_cache_flush(bs, s->refcount_block_cache); |
| if (ret) { |
| result = ret; |
| error_report("Failed to flush the refcount block cache: %s", |
| strerror(-ret)); |
| } |
| |
| if (result == 0) { |
| qcow2_mark_clean(bs); |
| } |
| |
| return result; |
| } |
| |
| static void qcow2_close(BlockDriverState *bs) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| qemu_vfree(s->l1_table); |
| /* else pre-write overlap checks in cache_destroy may crash */ |
| s->l1_table = NULL; |
| |
| if (!(s->flags & BDRV_O_INACTIVE)) { |
| qcow2_inactivate(bs); |
| } |
| |
| cache_clean_timer_del(bs); |
| qcow2_cache_destroy(s->l2_table_cache); |
| qcow2_cache_destroy(s->refcount_block_cache); |
| |
| qcrypto_block_free(s->crypto); |
| s->crypto = NULL; |
| qapi_free_QCryptoBlockOpenOptions(s->crypto_opts); |
| |
| g_free(s->unknown_header_fields); |
| cleanup_unknown_header_ext(bs); |
| |
| g_free(s->image_data_file); |
| g_free(s->image_backing_file); |
| g_free(s->image_backing_format); |
| |
| if (has_data_file(bs)) { |
| bdrv_unref_child(bs, s->data_file); |
| s->data_file = NULL; |
| } |
| |
| qcow2_refcount_close(bs); |
| qcow2_free_snapshots(bs); |
| } |
| |
| static void coroutine_fn qcow2_co_invalidate_cache(BlockDriverState *bs, |
| Error **errp) |
| { |
| 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; |
| qemu_co_mutex_lock(&s->lock); |
| ret = qcow2_do_open(bs, options, flags, &local_err); |
| qemu_co_mutex_unlock(&s->lock); |
| qobject_unref(options); |
| if (local_err) { |
| error_propagate_prepend(errp, local_err, |
| "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; |
| } |
| |
| /* External data file header extension */ |
| if (has_data_file(bs) && s->image_data_file) { |
| ret = header_ext_add(buf, QCOW2_EXT_MAGIC_DATA_FILE, |
| s->image_data_file, strlen(s->image_data_file), |
| buflen); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| buf += ret; |
| buflen -= ret; |
| } |
| |
| /* Full disk encryption header pointer extension */ |
| if (s->crypto_header.offset != 0) { |
| s->crypto_header.offset = cpu_to_be64(s->crypto_header.offset); |
| s->crypto_header.length = cpu_to_be64(s->crypto_header.length); |
| ret = header_ext_add(buf, QCOW2_EXT_MAGIC_CRYPTO_HEADER, |
| &s->crypto_header, sizeof(s->crypto_header), |
| buflen); |
| s->crypto_header.offset = be64_to_cpu(s->crypto_header.offset); |
| s->crypto_header.length = be64_to_cpu(s->crypto_header.length); |
| if (ret < 0) { |
| goto fail; |
| } |
| buf += ret; |
| buflen -= ret; |
| } |
| |
| /* |
| * Feature table. A mere 8 feature names occupies 392 bytes, and |
| * when coupled with the v3 minimum header of 104 bytes plus the |
| * 8-byte end-of-extension marker, that would leave only 8 bytes |
| * for a backing file name in an image with 512-byte clusters. |
| * Thus, we choose to omit this header for cluster sizes 4k and |
| * smaller. |
| */ |
| if (s->qcow_version >= 3 && s->cluster_size > 4096) { |
| static const Qcow2Feature features[] = { |
| { |
| .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
| .bit = QCOW2_INCOMPAT_DIRTY_BITNR, |
| .name = "dirty bit", |
| }, |
| { |
| .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
| .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, |
| .name = "corrupt bit", |
| }, |
| { |
| .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, |
| .bit = QCOW2_INCOMPAT_DATA_FILE_BITNR, |
| .name = "external data file", |
| }, |
| { |
| .type = QCOW2_FEAT_TYPE_COMPATIBLE, |
| .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, |
| .name = "lazy refcounts", |
| }, |
| { |
| .type = QCOW2_FEAT_TYPE_AUTOCLEAR, |
| .bit = QCOW2_AUTOCLEAR_BITMAPS_BITNR, |
| .name = "bitmaps", |
| }, |
| { |
| .type = QCOW2_FEAT_TYPE_AUTOCLEAR, |
| .bit = QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, |
| .name = "raw external data", |
| }, |
| }; |
| |
| ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, |
| features, sizeof(features), buflen); |
| if (ret < 0) { |
| goto fail; |
| } |
| buf += ret; |
| buflen -= ret; |
| } |
| |
| /* Bitmap extension */ |
| if (s->nb_bitmaps > 0) { |
| Qcow2BitmapHeaderExt bitmaps_header = { |
| .nb_bitmaps = cpu_to_be32(s->nb_bitmaps), |
| .bitmap_directory_size = |
| cpu_to_be64(s->bitmap_directory_size), |
| .bitmap_directory_offset = |
| cpu_to_be64(s->bitmap_directory_offset) |
| }; |
| ret = header_ext_add(buf, QCOW2_EXT_MAGIC_BITMAPS, |
| &bitmaps_header, sizeof(bitmaps_header), |
| buflen); |
| if (ret < 0) { |
| goto fail; |
| } |
| buf += ret; |
| buflen -= ret; |
| } |
| |
| /* Keep unknown header extensions */ |
| QLIST_FOREACH(uext, &s->unknown_header_ext, next) { |
| ret = header_ext_add(buf, uext->magic, uext->data, uext->len, buflen); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| buf += ret; |
| buflen -= ret; |
| } |
| |
| /* End of header extensions */ |
| ret = header_ext_add(buf, QCOW2_EXT_MAGIC_END, NULL, 0, buflen); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| buf += ret; |
| buflen -= ret; |
| |
| /* Backing file name */ |
| if (s->image_backing_file) { |
| size_t backing_file_len = strlen(s->image_backing_file); |
| |
| if (buflen < backing_file_len) { |
| ret = -ENOSPC; |
| goto fail; |
| } |
| |
| /* Using strncpy is ok here, since buf is not NUL-terminated. */ |
| strncpy(buf, s->image_backing_file, buflen); |
| |
| header->backing_file_offset = cpu_to_be64(buf - ((char*) header)); |
| header->backing_file_size = cpu_to_be32(backing_file_len); |
| } |
| |
| /* Write the new header */ |
| ret = bdrv_pwrite(bs->file, 0, header, s->cluster_size); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| ret = 0; |
| fail: |
| qemu_vfree(header); |
| return ret; |
| } |
| |
| static int qcow2_change_backing_file(BlockDriverState *bs, |
| const char *backing_file, const char *backing_fmt) |
| { |
| BDRVQcow2State *s = bs->opaque; |
| |
| /* Adding a backing file means that the external data file alone won't be |
| * enough to make sense of the content */ |
| if (backing_file && data_file_is_raw(bs)) { |
| return -EINVAL; |
| } |
| |
| if (backing_file && strlen(backing_file) > 1023) { |
| return -EINVAL; |
| } |
| |
| pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file), |
| backing_file ?: ""); |
| pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); |
| pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); |
| |
| g_free(s->image_backing_file); |
| g_free(s->image_backing_format); |
| |
| s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; |
| s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; |
| |
| return qcow2_update_header(bs); |
| |