diff options
Diffstat (limited to 'qemu/block/qcow2.c')
| -rw-r--r-- | qemu/block/qcow2.c | 3373 |
1 files changed, 0 insertions, 3373 deletions
diff --git a/qemu/block/qcow2.c b/qemu/block/qcow2.c deleted file mode 100644 index 470734be9..000000000 --- a/qemu/block/qcow2.c +++ /dev/null @@ -1,3373 +0,0 @@ -/* - * Block driver for the QCOW version 2 format - * - * Copyright (c) 2004-2006 Fabrice Bellard - * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to deal - * in the Software without restriction, including without limitation the rights - * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell - * copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, - * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN - * THE SOFTWARE. - */ -#include "qemu/osdep.h" -#include "block/block_int.h" -#include "sysemu/block-backend.h" -#include "qemu/module.h" -#include <zlib.h> -#include "block/qcow2.h" -#include "qemu/error-report.h" -#include "qapi/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" -#include "qemu/cutils.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) -{ - BDRVQcow2State *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->bs, 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->bs, 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->bs, 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->bs, offset , uext->data, uext->len); - if (ret < 0) { - error_setg_errno(errp, -ret, "ERROR: unknown extension: " - "Could not read data"); - return ret; - } - } - break; - } - - offset += ((ext.len + 7) & ~7); - } - - return 0; -} - -static void cleanup_unknown_header_ext(BlockDriverState *bs) -{ - BDRVQcow2State *s = bs->opaque; - Qcow2UnknownHeaderExtension *uext, *next; - - QLIST_FOREACH_SAFE(uext, &s->unknown_header_ext, next, next) { - QLIST_REMOVE(uext, next); - g_free(uext); - } -} - -static void report_unsupported_feature(Error **errp, Qcow2Feature *table, - uint64_t mask) -{ - char *features = g_strdup(""); - char *old; - - while (table && table->name[0] != '\0') { - if (table->type == QCOW2_FEAT_TYPE_INCOMPATIBLE) { - if (mask & (1ULL << table->bit)) { - old = features; - features = g_strdup_printf("%s%s%.46s", old, *old ? ", " : "", - table->name); - g_free(old); - mask &= ~(1ULL << table->bit); - } - } - table++; - } - - if (mask) { - old = features; - features = g_strdup_printf("%s%sUnknown incompatible feature: %" PRIx64, - old, *old ? ", " : "", mask); - g_free(old); - } - - error_setg(errp, "Unsupported qcow2 feature(s): %s", features); - g_free(features); -} - -/* - * Sets the dirty bit and flushes afterwards if necessary. - * - * The incompatible_features bit is only set if the image file header was - * updated successfully. Therefore it is not required to check the return - * value of this function. - */ -int qcow2_mark_dirty(BlockDriverState *bs) -{ - BDRVQcow2State *s = bs->opaque; - uint64_t val; - int ret; - - assert(s->qcow_version >= 3); - - if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { - return 0; /* already dirty */ - } - - val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY); - ret = bdrv_pwrite(bs->file->bs, 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 = 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) -{ - 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 = 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) -{ - BDRVQcow2State *s = bs->opaque; - uint64_t size; - - /* Use signed INT64_MAX as the maximum even for uint64_t header fields, - * because values will be passed to qemu functions taking int64_t. */ - if (entries > INT64_MAX / entry_len) { - return -EINVAL; - } - - size = entries * entry_len; - - if (INT64_MAX - size < offset) { - return -EINVAL; - } - - /* Tables must be cluster aligned */ - if (offset & (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", - }, - { - .name = QCOW2_OPT_CACHE_CLEAN_INTERVAL, - .type = QEMU_OPT_NUMBER, - .help = "Clean unused cache entries after this time (in seconds)", - }, - { /* end of list */ } - }, -}; - -static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = { - [QCOW2_OL_MAIN_HEADER_BITNR] = QCOW2_OPT_OVERLAP_MAIN_HEADER, - [QCOW2_OL_ACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L1, - [QCOW2_OL_ACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_ACTIVE_L2, - [QCOW2_OL_REFCOUNT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_TABLE, - [QCOW2_OL_REFCOUNT_BLOCK_BITNR] = QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK, - [QCOW2_OL_SNAPSHOT_TABLE_BITNR] = QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE, - [QCOW2_OL_INACTIVE_L1_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L1, - [QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2, -}; - -static void cache_clean_timer_cb(void *opaque) -{ - BlockDriverState *bs = opaque; - BDRVQcow2State *s = bs->opaque; - qcow2_cache_clean_unused(bs, s->l2_table_cache); - qcow2_cache_clean_unused(bs, 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 *refcount_cache_size, Error **errp) -{ - BDRVQcow2State *s = bs->opaque; - uint64_t combined_cache_size; - bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set; - - combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); - l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE); - refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE); - - combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0); - *l2_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, 0); - *refcount_cache_size = qemu_opt_get_size(opts, - QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); - - if (combined_cache_size_set) { - if (l2_cache_size_set && refcount_cache_size_set) { - error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE - " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set " - "the same time"); - return; - } else if (*l2_cache_size > combined_cache_size) { - error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed " - QCOW2_OPT_CACHE_SIZE); - return; - } else if (*refcount_cache_size > combined_cache_size) { - error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed " - QCOW2_OPT_CACHE_SIZE); - return; - } - - if (l2_cache_size_set) { - *refcount_cache_size = combined_cache_size - *l2_cache_size; - } else if (refcount_cache_size_set) { - *l2_cache_size = combined_cache_size - *refcount_cache_size; - } else { - *refcount_cache_size = combined_cache_size - / (DEFAULT_L2_REFCOUNT_SIZE_RATIO + 1); - *l2_cache_size = combined_cache_size - *refcount_cache_size; - } - } else { - if (!l2_cache_size_set && !refcount_cache_size_set) { - *l2_cache_size = MAX(DEFAULT_L2_CACHE_BYTE_SIZE, - (uint64_t)DEFAULT_L2_CACHE_CLUSTERS - * s->cluster_size); - *refcount_cache_size = *l2_cache_size - / DEFAULT_L2_REFCOUNT_SIZE_RATIO; - } else if (!l2_cache_size_set) { - *l2_cache_size = *refcount_cache_size - * DEFAULT_L2_REFCOUNT_SIZE_RATIO; - } else if (!refcount_cache_size_set) { - *refcount_cache_size = *l2_cache_size - / DEFAULT_L2_REFCOUNT_SIZE_RATIO; - } - } -} - -typedef struct Qcow2ReopenState { - Qcow2Cache *l2_table_cache; - Qcow2Cache *refcount_block_cache; - bool use_lazy_refcounts; - int overlap_check; - bool discard_passthrough[QCOW2_DISCARD_MAX]; - uint64_t cache_clean_interval; -} 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, refcount_cache_size; - int i; - Error *local_err = NULL; - int ret; - - 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, &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 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_table_cache = qcow2_cache_create(bs, l2_cache_size); - r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size); - if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) { - error_setg(errp, "Could not allocate metadata caches"); - ret = -ENOMEM; - goto fail; - } - - /* New interval for cache cleanup timer */ - r->cache_clean_interval = - qemu_opt_get_number(opts, QCOW2_OPT_CACHE_CLEAN_INTERVAL, - s->cache_clean_interval); - 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); - - ret = 0; -fail: - 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(bs, s->l2_table_cache); - } - if (s->refcount_block_cache) { - qcow2_cache_destroy(bs, s->refcount_block_cache); - } - s->l2_table_cache = r->l2_table_cache; - s->refcount_block_cache = r->refcount_block_cache; - - 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)); - } -} - -static void qcow2_update_options_abort(BlockDriverState *bs, - Qcow2ReopenState *r) -{ - if (r->l2_table_cache) { - qcow2_cache_destroy(bs, r->l2_table_cache); - } - if (r->refcount_block_cache) { - qcow2_cache_destroy(bs, r->refcount_block_cache); - } -} - -static int qcow2_update_options(BlockDriverState *bs, QDict *options, - int flags, Error **errp) -{ - Qcow2ReopenState r = {}; - int ret; - - ret = qcow2_update_options_prepare(bs, &r, options, flags, errp); - if (ret >= 0) { - qcow2_update_options_commit(bs, &r); - } else { - qcow2_update_options_abort(bs, &r); - } - - return ret; -} - -static int qcow2_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; - - ret = bdrv_pread(bs->file->bs, 0, &header, sizeof(header)); - if (ret < 0) { - error_setg_errno(errp, -ret, "Could not read qcow2 header"); - goto fail; - } - be32_to_cpus(&header.magic); - be32_to_cpus(&header.version); - be64_to_cpus(&header.backing_file_offset); - be32_to_cpus(&header.backing_file_size); - be64_to_cpus(&header.size); - be32_to_cpus(&header.cluster_bits); - be32_to_cpus(&header.crypt_method); - be64_to_cpus(&header.l1_table_offset); - be32_to_cpus(&header.l1_size); - be64_to_cpus(&header.refcount_table_offset); - be32_to_cpus(&header.refcount_table_clusters); - be64_to_cpus(&header.snapshots_offset); - be32_to_cpus(&header.nb_snapshots); - - if (header.magic != QCOW_MAGIC) { - error_setg(errp, "Image is not in qcow2 format"); - ret = -EINVAL; - goto fail; - } - if (header.version < 2 || header.version > 3) { - error_setg(errp, "Unsupported qcow2 version %" PRIu32, header.version); - ret = -ENOTSUP; - goto fail; - } - - s->qcow_version = header.version; - - /* Initialise cluster size */ - if (header.cluster_bits < MIN_CLUSTER_BITS || - header.cluster_bits > MAX_CLUSTER_BITS) { - error_setg(errp, "Unsupported cluster size: 2^%" PRIu32, - header.cluster_bits); - ret = -EINVAL; - goto fail; - } - - s->cluster_bits = header.cluster_bits; - s->cluster_size = 1 << s->cluster_bits; - s->cluster_sectors = 1 << (s->cluster_bits - 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->bs, 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(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; - - if (header.crypt_method > QCOW_CRYPT_AES) { - error_setg(errp, "Unsupported encryption method: %" PRIu32, - header.crypt_method); - ret = -EINVAL; - goto fail; - } - if (!qcrypto_cipher_supports(QCRYPTO_CIPHER_ALG_AES_128)) { - error_setg(errp, "AES cipher not available"); - ret = -EINVAL; - goto fail; - } - s->crypt_method_header = header.crypt_method; - if (s->crypt_method_header) { - if (bdrv_uses_whitelist() && - s->crypt_method_header == QCOW_CRYPT_AES) { - error_report("qcow2 built-in AES encryption is deprecated"); - error_printf("Support for it will be removed in a future release.\n" - "You can use 'qemu-img convert' to switch to an\n" - "unencrypted qcow2 image, or a LUKS raw image.\n"); - } - - 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 / sizeof(uint64_t)) { - error_setg(errp, "Active L1 table too large"); - ret = -EFBIG; - goto fail; - } - s->l1_size = header.l1_size; - - l1_vm_state_index = size_to_l1(s, header.size); - if (l1_vm_state_index > INT_MAX) { - error_setg(errp, "Image is too big"); - ret = -EFBIG; - goto fail; - } - s->l1_vm_state_index = l1_vm_state_index; - - /* the L1 table must contain at least enough entries to put - header.size bytes */ - if (s->l1_size < s->l1_vm_state_index) { - error_setg(errp, "L1 table is too small"); - ret = -EINVAL; - goto fail; - } - - ret = validate_table_offset(bs, header.l1_table_offset, - header.l1_size, sizeof(uint64_t)); - if (ret < 0) { - error_setg(errp, "Invalid L1 table offset"); - goto fail; - } - s->l1_table_offset = header.l1_table_offset; - - - if (s->l1_size > 0) { - s->l1_table = qemu_try_blockalign(bs->file->bs, - 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->bs, s->l1_table_offset, s->l1_table, - s->l1_size * sizeof(uint64_t)); - if (ret < 0) { - error_setg_errno(errp, -ret, "Could not read L1 table"); - goto fail; - } - for(i = 0;i < s->l1_size; i++) { - be64_to_cpus(&s->l1_table[i]); - } - } - - /* Parse driver-specific options */ - ret = qcow2_update_options(bs, options, flags, errp); - if (ret < 0) { - goto fail; - } - - s->cluster_cache = g_malloc(s->cluster_size); - /* one more sector for decompressed data alignment */ - s->cluster_data = qemu_try_blockalign(bs->file->bs, 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->bs, header.backing_file_offset, - bs->backing_file, len); - if (ret < 0) { - error_setg_errno(errp, -ret, "Could not read backing file name"); - goto fail; - } - bs->backing_file[len] = '\0'; - s->image_backing_file = g_strdup(bs->backing_file); - } - - /* Internal snapshots */ - s->snapshots_offset = header.snapshots_offset; - s->nb_snapshots = header.nb_snapshots; - - ret = qcow2_read_snapshots(bs); - if (ret < 0) { - error_setg_errno(errp, -ret, "Could not read snapshots"); - goto fail; - } - - /* Clear unknown autoclear feature bits */ - if (!bs->read_only && !(flags & BDRV_O_INACTIVE) && 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_INACTIVE)) && !bs->read_only && - (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) { - BdrvCheckResult result = {0}; - - ret = qcow2_check(bs, &result, BDRV_FIX_ERRORS | BDRV_FIX_LEAKS); - if (ret < 0) { - error_setg_errno(errp, -ret, "Could not repair dirty image"); - goto fail; - } - } - -#ifdef DEBUG_ALLOC - { - BdrvCheckResult result = {0}; - qcow2_check_refcounts(bs, &result, 0); - } -#endif - return ret; - - fail: - g_free(s->unknown_header_fields); - cleanup_unknown_header_ext(bs); - qcow2_free_snapshots(bs); - qcow2_refcount_close(bs); - qemu_vfree(s->l1_table); - /* else pre-write overlap checks in cache_destroy may crash */ - s->l1_table = NULL; - cache_clean_timer_del(bs); - if (s->l2_table_cache) { - qcow2_cache_destroy(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) -{ - BDRVQcow2State *s = bs->opaque; - - bs->bl.write_zeroes_alignment = s->cluster_sectors; -} - -static int qcow2_set_key(BlockDriverState *bs, const char *key) -{ - BDRVQcow2State *s = bs->opaque; - uint8_t keybuf[16]; - int len, i; - Error *err = NULL; - - 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]; - } - assert(bs->encrypted); - - qcrypto_cipher_free(s->cipher); - s->cipher = qcrypto_cipher_new( - QCRYPTO_CIPHER_ALG_AES_128, - QCRYPTO_CIPHER_MODE_CBC, - keybuf, G_N_ELEMENTS(keybuf), - &err); - - if (!s->cipher) { - /* XXX would be nice if errors in this method could - * be properly propagate to the caller. Would need - * the bdrv_set_key() API signature to be fixed. */ - error_free(err); - return -1; - } - return 0; -} - -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 = bdrv_flush(state->bs); - if (ret < 0) { - goto fail; - } - - ret = qcow2_mark_clean(state->bs); - if (ret < 0) { - goto fail; - } - } - - return 0; - -fail: - qcow2_update_options_abort(state->bs, r); - g_free(r); - return ret; -} - -static void qcow2_reopen_commit(BDRVReopenState *state) -{ - qcow2_update_options_commit(state->bs, state->opaque); - g_free(state->opaque); -} - -static void qcow2_reopen_abort(BDRVReopenState *state) -{ - qcow2_update_options_abort(state->bs, state->opaque); - g_free(state->opaque); -} - -static void qcow2_join_options(QDict *options, QDict *old_options) -{ - bool has_new_overlap_template = - qdict_haskey(options, QCOW2_OPT_OVERLAP) || - qdict_haskey(options, QCOW2_OPT_OVERLAP_TEMPLATE); - bool has_new_total_cache_size = - qdict_haskey(options, QCOW2_OPT_CACHE_SIZE); - bool has_all_cache_options; - - /* New overlap template overrides all old overlap options */ - if (has_new_overlap_template) { - qdict_del(old_options, QCOW2_OPT_OVERLAP); - qdict_del(old_options, QCOW2_OPT_OVERLAP_TEMPLATE); - qdict_del(old_options, QCOW2_OPT_OVERLAP_MAIN_HEADER); - qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L1); - qdict_del(old_options, QCOW2_OPT_OVERLAP_ACTIVE_L2); - qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_TABLE); - qdict_del(old_options, QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK); - qdict_del(old_options, QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE); - qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L1); - qdict_del(old_options, QCOW2_OPT_OVERLAP_INACTIVE_L2); - } - - /* New total cache size overrides all old options */ - if (qdict_haskey(options, QCOW2_OPT_CACHE_SIZE)) { - qdict_del(old_options, QCOW2_OPT_L2_CACHE_SIZE); - qdict_del(old_options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); - } - - qdict_join(options, old_options, false); - - /* - * If after merging all cache size options are set, an old total size is - * overwritten. Do keep all options, however, if all three are new. The - * resulting error message is what we want to happen. - */ - has_all_cache_options = - qdict_haskey(options, QCOW2_OPT_CACHE_SIZE) || - qdict_haskey(options, QCOW2_OPT_L2_CACHE_SIZE) || - qdict_haskey(options, QCOW2_OPT_REFCOUNT_CACHE_SIZE); - - if (has_all_cache_options && !has_new_total_cache_size) { - qdict_del(options, QCOW2_OPT_CACHE_SIZE); - } -} - -static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs, - int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file) -{ - BDRVQcow2State *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->cipher) { - index_in_cluster = sector_num & (s->cluster_sectors - 1); - cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS); - *file = bs->file->bs; - 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) -{ - BDRVQcow2State *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->cipher) { - 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) { - /* read from the base image */ - n1 = qcow2_backing_read1(bs->backing->bs, &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->bs, 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 (bs->encrypted) { - assert(s->cipher); - - /* - * For encrypted images, read everything into a temporary - * contiguous buffer on which the AES functions can work. - */ - if (!cluster_data) { - cluster_data = - qemu_try_blockalign(bs->file->bs, - QCOW_MAX_CRYPT_CLUSTERS - * s->cluster_size); - if (cluster_data == NULL) { - ret = -ENOMEM; - goto fail; - } - } - - assert(cur_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->bs, - (cluster_offset >> 9) + index_in_cluster, - cur_nr_sectors, &hd_qiov); - qemu_co_mutex_lock(&s->lock); - if (ret < 0) { - goto fail; - } - if (bs->encrypted) { - assert(s->cipher); - Error *err = NULL; - if (qcow2_encrypt_sectors(s, sector_num, cluster_data, - cluster_data, cur_nr_sectors, false, - &err) < 0) { - error_free(err); - ret = -EIO; - goto fail; - } - 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) -{ - BDRVQcow2State *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 (bs->encrypted && - 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 (bs->encrypted) { - Error *err = NULL; - assert(s->cipher); - if (!cluster_data) { - cluster_data = qemu_try_blockalign(bs->file->bs, - QCOW_MAX_CRYPT_CLUSTERS - * s->cluster_size); - if (cluster_data == NULL) { - ret = -ENOMEM; - goto fail; - } - } - - assert(hd_qiov.size <= - QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size); - qemu_iovec_to_buf(&hd_qiov, 0, cluster_data, hd_qiov.size); - - if (qcow2_encrypt_sectors(s, sector_num, cluster_data, - cluster_data, cur_nr_sectors, - true, &err) < 0) { - error_free(err); - ret = -EIO; - goto fail; - } - - 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->bs, - (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 int qcow2_inactivate(BlockDriverState *bs) -{ - BDRVQcow2State *s = bs->opaque; - int ret, result = 0; - - 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(bs, s->l2_table_cache); - qcow2_cache_destroy(bs, s->refcount_block_cache); - - qcrypto_cipher_free(s->cipher); - s->cipher = NULL; - - g_free(s->unknown_header_fields); - cleanup_unknown_header_ext(bs); - - g_free(s->image_backing_file); - g_free(s->image_backing_format); - - g_free(s->cluster_cache); - qemu_vfree(s->cluster_data); - qcow2_refcount_close(bs); - qcow2_free_snapshots(bs); -} - -static void qcow2_invalidate_cache(BlockDriverState *bs, Error **errp) -{ - BDRVQcow2State *s = bs->opaque; - int flags = s->flags; - QCryptoCipher *cipher = 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. - */ - - cipher = s->cipher; - s->cipher = NULL; - - qcow2_close(bs); - - bdrv_invalidate_cache(bs->file->bs, &local_err); - if (local_err) { - error_propagate(errp, local_err); - bs->drv = NULL; - return; - } - - memset(s, 0, sizeof(BDRVQcow2State)); - options = qdict_clone_shallow(bs->options); - - flags &= ~BDRV_O_INACTIVE; - ret = qcow2_open(bs, options, flags, &local_err); - QDECREF(options); - if (local_err) { - error_propagate(errp, local_err); - error_prepend(errp, "Could not reopen qcow2 layer: "); - bs->drv = NULL; - return; - } else if (ret < 0) { - error_setg_errno(errp, -ret, "Could not reopen qcow2 layer"); - bs->drv = NULL; - return; - } - - s->cipher = cipher; -} - -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) -{ - 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; - } - - /* Feature table */ - if (s->qcow_version >= 3) { - Qcow2Feature features[] = { - { - .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, - .bit = QCOW2_INCOMPAT_DIRTY_BITNR, - .name = "dirty bit", - }, - { - .type = QCOW2_FEAT_TYPE_INCOMPATIBLE, - .bit = QCOW2_INCOMPAT_CORRUPT_BITNR, - .name = "corrupt bit", - }, - { - .type = QCOW2_FEAT_TYPE_COMPATIBLE, - .bit = QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, - .name = "lazy refcounts", - }, - }; - - ret = header_ext_add(buf, QCOW2_EXT_MAGIC_FEATURE_TABLE, - features, sizeof(features), buflen); - if (ret < 0) { - goto fail; - } - buf += ret; - buflen -= ret; - } - - /* 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->bs, 0, header, s->cluster_size); - if (ret < 0) { - goto fail; - } - - ret = 0; -fail: - qemu_vfree(header); - return ret; -} - -static int qcow2_change_backing_file(BlockDriverState *bs, - const char *backing_file, const char *backing_fmt) -{ - BDRVQcow2State *s = bs->opaque; - - if (backing_file && strlen(backing_file) > 1023) { - return -EINVAL; - } - - pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); - pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); - - g_free(s->image_backing_file); - g_free(s->image_backing_format); - - s->image_backing_file = backing_file ? g_strdup(bs->backing_file) : NULL; - s->image_backing_format = backing_fmt ? g_strdup(bs->backing_format) : NULL; - - return qcow2_update_header(bs); -} - -static int 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->bs, - (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, int refcount_order, - Error **errp) -{ - int cluster_bits; - QDict *options; - - /* Calculate cluster_bits */ - cluster_bits = ctz32(cluster_size); - if (cluster_bits < MIN_CLUSTER_BITS || cluster_bits > MAX_CLUSTER_BITS || - (1 << cluster_bits) != cluster_size) - { - error_setg(errp, "Cluster size must be a power of two between %d and " - "%dk", 1 << MIN_CLUSTER_BITS, 1 << (MAX_CLUSTER_BITS - 10)); - return -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. - */ - BlockBackend *blk; - QCowHeader *header; - uint64_t* refcount_table; - Error *local_err = NULL; - int ret; - - if (prealloc == PREALLOC_MODE_FULL || prealloc == PREALLOC_MODE_FALLOC) { - /* Note: The following calculation does not need to be exact; if it is a - * bit off, either some bytes will be "leaked" (which is fine) or we - * will need to increase the file size by some bytes (which is fine, - * too, as long as the bulk is allocated here). Therefore, using - * floating point arithmetic is fine. */ - int64_t meta_size = 0; - uint64_t nreftablee, nrefblocke, nl1e, nl2e; - int64_t aligned_total_size = align_offset(total_size, cluster_size); - int refblock_bits, refblock_size; - /* refcount entry size in bytes */ - double rces = (1 << refcount_order) / 8.; - - /* see qcow2_open() */ - refblock_bits = cluster_bits - (refcount_order - 3); - refblock_size = 1 << refblock_bits; - - /* 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 - * rces = refcount entry size in bytes - * then, - * y1 = (y2 + a)/c - * y2 = y1 * rces + y1 * rces * sizeof(u64) / c + m - * we can get y1: - * y1 = (a + m) / (c - rces - rces * sizeof(u64) / c) - */ - nrefblocke = (aligned_total_size + meta_size + cluster_size) - / (cluster_size - rces - rces * sizeof(uint64_t) - / cluster_size); - meta_size += DIV_ROUND_UP(nrefblocke, refblock_size) * cluster_size; - - /* total size of refcount tables */ - nreftablee = nrefblocke / refblock_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; - } - - blk = blk_new_open(filename, NULL, NULL, - BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err); - if (blk == NULL) { - error_propagate(errp, local_err); - return -EIO; - } - - blk_set_allow_write_beyond_eof(blk, true); - - /* Write the header */ - QEMU_BUILD_BUG_ON((1 << MIN_CLUSTER_BITS) < sizeof(*header)); - header = g_malloc0(cluster_size); - *header = (QCowHeader) { - .magic = cpu_to_be32(QCOW_MAGIC), - .version = cpu_to_be32(version), - .cluster_bits = cpu_to_be32(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(refcount_order), - .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 = blk_pwrite(blk, 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 = blk_pwrite(blk, 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; - } - - blk_unref(blk); - blk = NULL; - - /* - * And now open the image and make it consistent first (i.e. increase the - * refcount of the cluster that is occupied by the header and the refcount - * table) - */ - options = qdict_new(); - qdict_put(options, "driver", qstring_from_str("qcow2")); - blk = blk_new_open(filename, NULL, options, - BDRV_O_RDWR | BDRV_O_NO_FLUSH, &local_err); - if (blk == NULL) { - error_propagate(errp, local_err); - ret = -EIO; - goto out; - } - - ret = qcow2_alloc_clusters(blk_bs(blk), 3 * cluster_size); - if (ret < 0) { - error_setg_errno(errp, -ret, "Could not allocate clusters for qcow2 " - "header and refcount table"); - goto out; - - } else if (ret != 0) { - error_report("Huh, first cluster in empty image is already in use?"); - abort(); - } - - /* Create a full header (including things like feature table) */ - ret = qcow2_update_header(blk_bs(blk)); - if (ret < 0) { - error_setg_errno(errp, -ret, "Could not update qcow2 header"); - goto out; - } - - /* Okay, now that we have a valid image, let's give it the right size */ - ret = blk_truncate(blk, total_size); - 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(blk_bs(blk), backing_file, backing_format); - if (ret < 0) { - error_setg_errno(errp, -ret, "Could not assign backing file '%s' " - "with format '%s'", backing_file, backing_format); - goto out; - } - } - - /* And if we're supposed to preallocate metadata, do that now */ - if (prealloc != PREALLOC_MODE_OFF) { - BDRVQcow2State *s = blk_bs(blk)->opaque; - qemu_co_mutex_lock(&s->lock); - ret = preallocate(blk_bs(blk)); - qemu_co_mutex_unlock(&s->lock); - if (ret < 0) { - error_setg_errno(errp, -ret, "Could not preallocate metadata"); - goto out; - } - } - - blk_unref(blk); - blk = NULL; - - /* Reopen the image without BDRV_O_NO_FLUSH to flush it before returning */ - options = qdict_new(); - qdict_put(options, "driver", qstring_from_str("qcow2")); - blk = blk_new_open(filename, NULL, options, - BDRV_O_RDWR | BDRV_O_NO_BACKING, &local_err); - if (blk == NULL) { - error_propagate(errp, local_err); - ret = -EIO; - goto out; - } - - ret = 0; -out: - if (blk) { - blk_unref(blk); - } - return ret; -} - -static int 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; - uint64_t refcount_bits = 16; - int refcount_order; - 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; - } - - refcount_bits = qemu_opt_get_number_del(opts, BLOCK_OPT_REFCOUNT_BITS, - refcount_bits); - if (refcount_bits > 64 || !is_power_of_2(refcount_bits)) { - error_setg(errp, "Refcount width must be a power of two and may not " - "exceed 64 bits"); - ret = -EINVAL; - goto finish; - } - - if (version < 3 && refcount_bits != 16) { - error_setg(errp, "Different refcount widths than 16 bits require " - "compatibility level 1.1 or above (use compat=1.1 or " - "greater)"); - ret = -EINVAL; - goto finish; - } - - refcount_order = ctz32(refcount_bits); - - ret = qcow2_create2(filename, size, backing_file, backing_fmt, flags, - cluster_size, prealloc, opts, version, refcount_order, - &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; - BDRVQcow2State *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; - BDRVQcow2State *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) -{ - BDRVQcow2State *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->bs, 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) -{ - BDRVQcow2State *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->bs); - return bdrv_truncate(bs->file->bs, 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->bs, 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) -{ - BDRVQcow2State *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->bs, 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->bs, 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->bs, 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->bs, 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->bs, (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) -{ - BDRVQcow2State *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) -{ - BDRVQcow2State *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) -{ - BDRVQcow2State *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) -{ - BDRVQcow2State *s = bs->opaque; - ImageInfoSpecific *spec_info = g_new(ImageInfoSpecific, 1); - - *spec_info = (ImageInfoSpecific){ - .type = IMAGE_INFO_SPECIFIC_KIND_QCOW2, - .u.qcow2.data = g_new(ImageInfoSpecificQCow2, 1), - }; - if (s->qcow_version == 2) { - *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ - .compat = g_strdup("0.10"), - .refcount_bits = s->refcount_bits, - }; - } else if (s->qcow_version == 3) { - *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){ - .compat = g_strdup("1.1"), - .lazy_refcounts = s->compatible_features & - QCOW2_COMPAT_LAZY_REFCOUNTS, - .has_lazy_refcounts = true, - .corrupt = s->incompatible_features & - QCOW2_INCOMPAT_CORRUPT, - .has_corrupt = true, - .refcount_bits = s->refcount_bits, - }; - } else { - /* if this assertion fails, this probably means a new version was - * added without having it covered here */ - assert(false); - } - - return spec_info; -} - -#if 0 -static void dump_refcounts(BlockDriverState *bs) -{ - BDRVQcow2State *s = bs->opaque; - int64_t nb_clusters, k, k1, size; - int refcount; - - size = bdrv_getlength(bs->file->bs); - 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) -{ - BDRVQcow2State *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) -{ - BDRVQcow2State *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, void *cb_opaque) -{ - BDRVQcow2State *s = bs->opaque; - int current_version = s->qcow_version; - int ret; - - if (target_version == current_version) { - return 0; - } else if (target_version > current_version) { - return -EINVAL; - } else if (target_version != 2) { - return -EINVAL; - } - - if (s->refcount_order != 4) { - error_report("compat=0.10 requires refcount_bits=16"); - return -ENOTSUP; - } - - /* clear incompatible features */ - if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) { - ret = qcow2_mark_clean(bs); - if (ret < 0) { - return ret; - } - } - - /* with QCOW2_INCOMPAT_CORRUPT, it is pretty much impossible to get here in - * the first place; if that happens nonetheless, returning -ENOTSUP is the - * best thing to do anyway */ - - if (s->incompatible_features) { - return -ENOTSUP; - } - - /* since we can ignore compatible features, we can set them to 0 as well */ - s->compatible_features = 0; - /* if lazy refcounts have been used, they have already been fixed through - * clearing the dirty flag */ - - /* clearing autoclear features is trivial */ - s->autoclear_features = 0; - - ret = qcow2_expand_zero_clusters(bs, status_cb, cb_opaque); - if (ret < 0) { - return ret; - } - - s->qcow_version = target_version; - ret = qcow2_update_header(bs); - if (ret < 0) { - s->qcow_version = current_version; - return ret; - } - return 0; -} - -typedef enum Qcow2AmendOperation { - /* This is the value Qcow2AmendHelperCBInfo::last_operation will be - * statically initialized to so that the helper CB can discern the first - * invocation from an operation change */ - QCOW2_NO_OPERATION = 0, - - QCOW2_CHANGING_REFCOUNT_ORDER, - QCOW2_DOWNGRADING, -} Qcow2AmendOperation; - -typedef struct Qcow2AmendHelperCBInfo { - /* The code coordinating the amend operations should only modify - * these four fields; the rest will be managed by the CB */ - BlockDriverAmendStatusCB *original_status_cb; - void *original_cb_opaque; - - Qcow2AmendOperation current_operation; - - /* Total number of operations to perform (only set once) */ - int total_operations; - - /* The following fields are managed by the CB */ - - /* Number of operations completed */ - int operations_completed; - - /* Cumulative offset of all completed operations */ - int64_t offset_completed; - - Qcow2AmendOperation last_operation; - int64_t last_work_size; -} Qcow2AmendHelperCBInfo; - -static void qcow2_amend_helper_cb(BlockDriverState *bs, - int64_t operation_offset, - int64_t operation_work_size, void *opaque) -{ - Qcow2AmendHelperCBInfo *info = opaque; - int64_t current_work_size; - int64_t projected_work_size; - - if (info->current_operation != info->last_operation) { - if (info->last_operation != QCOW2_NO_OPERATION) { - info->offset_completed += info->last_work_size; - info->operations_completed++; - } - - info->last_operation = info->current_operation; - } - - assert(info->total_operations > 0); - assert(info->operations_completed < info->total_operations); - - info->last_work_size = operation_work_size; - - current_work_size = info->offset_completed + operation_work_size; - - /* current_work_size is the total work size for (operations_completed + 1) - * operations (which includes this one), so multiply it by the number of - * operations not covered and divide it by the number of operations - * covered to get a projection for the operations not covered */ - projected_work_size = current_work_size * (info->total_operations - - info->operations_completed - 1) - / (info->operations_completed + 1); - - info->original_status_cb(bs, info->offset_completed + operation_offset, - current_work_size + projected_work_size, - info->original_cb_opaque); -} - -static int qcow2_amend_options(BlockDriverState *bs, QemuOpts *opts, - BlockDriverAmendStatusCB *status_cb, - void *cb_opaque) -{ - BDRVQcow2State *s = bs->opaque; - int old_version = s->qcow_version, new_version = old_version; - uint64_t new_size = 0; - const char *backing_file = NULL, *backing_format = NULL; - bool lazy_refcounts = s->use_lazy_refcounts; - const char *compat = NULL; - uint64_t cluster_size = s->cluster_size; - bool encrypt; - int refcount_bits = s->refcount_bits; - int ret; - QemuOptDesc *desc = opts->list->desc; - Qcow2AmendHelperCBInfo helper_cb_info; - - while (desc && desc->name) { - if (!qemu_opt_find(opts, desc->name)) { - /* only change explicitly defined options */ - desc++; - continue; - } - - if (!strcmp(desc->name, BLOCK_OPT_COMPAT_LEVEL)) { - compat = qemu_opt_get(opts, BLOCK_OPT_COMPAT_LEVEL); - if (!compat) { - /* preserve default */ - } else if (!strcmp(compat, "0.10")) { - new_version = 2; - } else if (!strcmp(compat, "1.1")) { - new_version = 3; - } else { - error_report("Unknown compatibility level %s", compat); - return -EINVAL; - } - } else if (!strcmp(desc->name, BLOCK_OPT_PREALLOC)) { - error_report("Cannot change preallocation mode"); - return -ENOTSUP; - } else if (!strcmp(desc->name, BLOCK_OPT_SIZE)) { - new_size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); - } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FILE)) { - backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); - } else if (!strcmp(desc->name, BLOCK_OPT_BACKING_FMT)) { - backing_format = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); - } else if (!strcmp(desc->name, BLOCK_OPT_ENCRYPT)) { - encrypt = qemu_opt_get_bool(opts, BLOCK_OPT_ENCRYPT, - !!s->cipher); - - if (encrypt != !!s->cipher) { - error_report("Changing the encryption flag is not supported"); - return -ENOTSUP; - } - } else if (!strcmp(desc->name, BLOCK_OPT_CLUSTER_SIZE)) { - cluster_size = qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, - cluster_size); - if (cluster_size != s->cluster_size) { - error_report("Changing the cluster size is not supported"); - return -ENOTSUP; - } - } else if (!strcmp(desc->name, BLOCK_OPT_LAZY_REFCOUNTS)) { - lazy_refcounts = qemu_opt_get_bool(opts, BLOCK_OPT_LAZY_REFCOUNTS, - lazy_refcounts); - } else if (!strcmp(desc->name, BLOCK_OPT_REFCOUNT_BITS)) { - refcount_bits = qemu_opt_get_number(opts, BLOCK_OPT_REFCOUNT_BITS, - refcount_bits); - - if (refcount_bits <= 0 || refcount_bits > 64 || - !is_power_of_2(refcount_bits)) - { - error_report("Refcount width must be a power of two and may " - "not exceed 64 bits"); - return -EINVAL; - } - } else { - /* if this point is reached, this probably means a new option was - * added without having it covered here */ - abort(); - } - - desc++; - } - - helper_cb_info = (Qcow2AmendHelperCBInfo){ - .original_status_cb = status_cb, - .original_cb_opaque = cb_opaque, - .total_operations = (new_version < old_version) - + (s->refcount_bits != refcount_bits) - }; - - /* Upgrade first (some features may require compat=1.1) */ - if (new_version > old_version) { - s->qcow_version = new_version; - ret = qcow2_update_header(bs); - if (ret < 0) { - s->qcow_version = old_version; - return ret; - } - } - - if (s->refcount_bits != refcount_bits) { - int refcount_order = ctz32(refcount_bits); - Error *local_error = NULL; - - if (new_version < 3 && refcount_bits != 16) { - error_report("Different refcount widths than 16 bits require " - "compatibility level 1.1 or above (use compat=1.1 or " - "greater)"); - return -EINVAL; - } - - helper_cb_info.current_operation = QCOW2_CHANGING_REFCOUNT_ORDER; - ret = qcow2_change_refcount_order(bs, refcount_order, - &qcow2_amend_helper_cb, - &helper_cb_info, &local_error); - if (ret < 0) { - error_report_err(local_error); - return ret; - } - } - - if (backing_file || backing_format) { - ret = qcow2_change_backing_file(bs, - backing_file ?: s->image_backing_file, - backing_format ?: s->image_backing_format); - if (ret < 0) { - return ret; - } - } - - if (s->use_lazy_refcounts != lazy_refcounts) { - if (lazy_refcounts) { - if (new_version < 3) { - error_report("Lazy refcounts only supported with compatibility " - "level 1.1 and above (use compat=1.1 or greater)"); - return -EINVAL; - } - s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; - ret = qcow2_update_header(bs); - if (ret < 0) { - s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; - return ret; - } - s->use_lazy_refcounts = true; - } else { - /* make image clean first */ - ret = qcow2_mark_clean(bs); - if (ret < 0) { - return ret; - } - /* now disallow lazy refcounts */ - s->compatible_features &= ~QCOW2_COMPAT_LAZY_REFCOUNTS; - ret = qcow2_update_header(bs); - if (ret < 0) { - s->compatible_features |= QCOW2_COMPAT_LAZY_REFCOUNTS; - return ret; - } - s->use_lazy_refcounts = false; - } - } - - if (new_size) { - ret = bdrv_truncate(bs, new_size); - if (ret < 0) { - return ret; - } - } - - /* Downgrade last (so unsupported features can be removed before) */ - if (new_version < old_version) { - helper_cb_info.current_operation = QCOW2_DOWNGRADING; - ret = qcow2_downgrade(bs, new_version, &qcow2_amend_helper_cb, - &helper_cb_info); - if (ret < 0) { - return ret; - } - } - - return 0; -} - -/* - * If offset or size are negative, respectively, they will not be included in - * the BLOCK_IMAGE_CORRUPTED event emitted. - * fatal will be ignored for read-only BDS; corruptions found there will always - * be considered non-fatal. - */ -void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, - int64_t size, const char *message_format, ...) -{ - BDRVQcow2State *s = bs->opaque; - const char *node_name; - char *message; - va_list ap; - - fatal = fatal && !bs->read_only; - - if (s->signaled_corruption && - (!fatal || (s->incompatible_features & QCOW2_INCOMPAT_CORRUPT))) - { - return; - } - - va_start(ap, message_format); - message = g_strdup_vprintf(message_format, ap); - va_end(ap); - - if (fatal) { - fprintf(stderr, "qcow2: Marking image as corrupt: %s; further " - "corruption events will be suppressed\n", message); - } else { - fprintf(stderr, "qcow2: Image is corrupt: %s; further non-fatal " - "corruption events will be suppressed\n", message); - } - - node_name = bdrv_get_node_name(bs); - qapi_event_send_block_image_corrupted(bdrv_get_device_name(bs), - *node_name != '\0', node_name, - message, offset >= 0, offset, - size >= 0, size, - fatal, &error_abort); - g_free(message); - - if (fatal) { - qcow2_mark_corrupt(bs); - bs->drv = NULL; /* make BDS unusable */ - } - - s->signaled_corruption = true; -} - -static QemuOptsList qcow2_create_opts = { - .name = "qcow2-create-opts", - .head = QTAILQ_HEAD_INITIALIZER(qcow2_create_opts.head), - .desc = { - { - .name = BLOCK_OPT_SIZE, - .type = QEMU_OPT_SIZE, - .help = "Virtual disk size" - }, - { - .name = BLOCK_OPT_COMPAT_LEVEL, - .type = QEMU_OPT_STRING, - .help = "Compatibility level (0.10 or 1.1)" - }, - { - .name = BLOCK_OPT_BACKING_FILE, - .type = QEMU_OPT_STRING, - .help = "File name of a base image" - }, - { - .name = BLOCK_OPT_BACKING_FMT, - .type = QEMU_OPT_STRING, - .help = "Image format of the base image" - }, - { - .name = BLOCK_OPT_ENCRYPT, - .type = QEMU_OPT_BOOL, - .help = "Encrypt the image", - .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" - }, - { - .name = BLOCK_OPT_REFCOUNT_BITS, - .type = QEMU_OPT_NUMBER, - .help = "Width of a reference count entry in bits", - .def_value_str = "16" - }, - { /* end of list */ } - } -}; - -BlockDriver bdrv_qcow2 = { - .format_name = "qcow2", - .instance_size = sizeof(BDRVQcow2State), - .bdrv_probe = qcow2_probe, - .bdrv_open = qcow2_open, - .bdrv_close = qcow2_close, - .bdrv_reopen_prepare = qcow2_reopen_prepare, - .bdrv_reopen_commit = qcow2_reopen_commit, - .bdrv_reopen_abort = qcow2_reopen_abort, - .bdrv_join_options = qcow2_join_options, - .bdrv_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, - .bdrv_inactivate = qcow2_inactivate, - - .create_opts = &qcow2_create_opts, - .bdrv_check = qcow2_check, - .bdrv_amend_options = qcow2_amend_options, - - .bdrv_detach_aio_context = qcow2_detach_aio_context, - .bdrv_attach_aio_context = qcow2_attach_aio_context, -}; - -static void bdrv_qcow2_init(void) -{ - bdrv_register(&bdrv_qcow2); -} - -block_init(bdrv_qcow2_init); |