From c8fd8554d972904bd0b04673298fea1af7a37780 Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Fri, 10 Jul 2020 18:12:54 +0200 Subject: [PATCH] qcow2: Add l2_entry_size() qcow2 images with subclusters have 128-bit L2 entries. The first 64 bits contain the same information as traditional images and the last 64 bits form a bitmap with the status of each individual subcluster. Because of that we cannot assume that L2 entries are sizeof(uint64_t) anymore. This function returns the proper value for the image. Signed-off-by: Alberto Garcia Reviewed-by: Max Reitz Message-Id: Signed-off-by: Max Reitz --- block/qcow2-cluster.c | 12 ++++++------ block/qcow2-refcount.c | 14 ++++++++------ block/qcow2.c | 8 ++++---- block/qcow2.h | 9 +++++++++ 4 files changed, 27 insertions(+), 16 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 5bd1e1feb8..0b762502f6 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -208,7 +208,7 @@ static int l2_load(BlockDriverState *bs, uint64_t offset, uint64_t l2_offset, uint64_t **l2_slice) { BDRVQcow2State *s = bs->opaque; - int start_of_slice = sizeof(uint64_t) * + int start_of_slice = l2_entry_size(s) * (offset_to_l2_index(s, offset) - offset_to_l2_slice_index(s, offset)); return qcow2_cache_get(bs, s->l2_table_cache, l2_offset + start_of_slice, @@ -281,7 +281,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index) /* allocate a new l2 entry */ - l2_offset = qcow2_alloc_clusters(bs, s->l2_size * sizeof(uint64_t)); + l2_offset = qcow2_alloc_clusters(bs, s->l2_size * l2_entry_size(s)); if (l2_offset < 0) { ret = l2_offset; goto fail; @@ -305,7 +305,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index) /* allocate a new entry in the l2 cache */ - slice_size2 = s->l2_slice_size * sizeof(uint64_t); + slice_size2 = s->l2_slice_size * l2_entry_size(s); n_slices = s->cluster_size / slice_size2; trace_qcow2_l2_allocate_get_empty(bs, l1_index); @@ -369,7 +369,7 @@ fail: } s->l1_table[l1_index] = old_l2_offset; if (l2_offset > 0) { - qcow2_free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t), + qcow2_free_clusters(bs, l2_offset, s->l2_size * l2_entry_size(s), QCOW2_DISCARD_ALWAYS); } return ret; @@ -717,7 +717,7 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset, /* Then decrease the refcount of the old table */ if (l2_offset) { - qcow2_free_clusters(bs, l2_offset, s->l2_size * sizeof(uint64_t), + qcow2_free_clusters(bs, l2_offset, s->l2_size * l2_entry_size(s), QCOW2_DISCARD_OTHER); } @@ -1921,7 +1921,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, int ret; int i, j; - slice_size2 = s->l2_slice_size * sizeof(uint64_t); + slice_size2 = s->l2_slice_size * l2_entry_size(s); n_slices = s->cluster_size / slice_size2; if (!is_active_l1) { diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 04546838e8..770c5dbc83 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1254,7 +1254,7 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs, l2_slice = NULL; l1_table = NULL; l1_size2 = l1_size * sizeof(uint64_t); - slice_size2 = s->l2_slice_size * sizeof(uint64_t); + slice_size2 = s->l2_slice_size * l2_entry_size(s); n_slices = s->cluster_size / slice_size2; s->cache_discards = true; @@ -1605,7 +1605,7 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, int i, l2_size, nb_csectors, ret; /* Read L2 table from disk */ - l2_size = s->l2_size * sizeof(uint64_t); + l2_size = s->l2_size * l2_entry_size(s); l2_table = g_malloc(l2_size); ret = bdrv_pread(bs->file, l2_offset, l2_table, l2_size); @@ -1680,15 +1680,16 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", offset); if (fix & BDRV_FIX_ERRORS) { + int idx = i * (l2_entry_size(s) / sizeof(uint64_t)); uint64_t l2e_offset = - l2_offset + (uint64_t)i * sizeof(uint64_t); + l2_offset + (uint64_t)i * l2_entry_size(s); int ign = active ? QCOW2_OL_ACTIVE_L2 : QCOW2_OL_INACTIVE_L2; l2_entry = QCOW_OFLAG_ZERO; set_l2_entry(s, l2_table, i, l2_entry); ret = qcow2_pre_write_overlap_check(bs, ign, - l2e_offset, sizeof(uint64_t), false); + l2e_offset, l2_entry_size(s), false); if (ret < 0) { fprintf(stderr, "ERROR: Overlap check failed\n"); res->check_errors++; @@ -1698,7 +1699,8 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, } ret = bdrv_pwrite_sync(bs->file, l2e_offset, - &l2_table[i], sizeof(uint64_t)); + &l2_table[idx], + l2_entry_size(s)); if (ret < 0) { fprintf(stderr, "ERROR: Failed to overwrite L2 " "table entry: %s\n", strerror(-ret)); @@ -1905,7 +1907,7 @@ static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res, } ret = bdrv_pread(bs->file, l2_offset, l2_table, - s->l2_size * sizeof(uint64_t)); + s->l2_size * l2_entry_size(s)); if (ret < 0) { fprintf(stderr, "ERROR: Could not read L2 table: %s\n", strerror(-ret)); diff --git a/block/qcow2.c b/block/qcow2.c index fb4584d3ee..edbf9fbd0a 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -883,7 +883,7 @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, uint64_t max_l2_entries = DIV_ROUND_UP(virtual_disk_size, s->cluster_size); /* An L2 table is always one cluster in size so the max cache size * should be a multiple of the cluster size. */ - uint64_t max_l2_cache = ROUND_UP(max_l2_entries * sizeof(uint64_t), + uint64_t max_l2_cache = ROUND_UP(max_l2_entries * l2_entry_size(s), s->cluster_size); combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE); @@ -1042,7 +1042,7 @@ static int qcow2_update_options_prepare(BlockDriverState *bs, } } - r->l2_slice_size = l2_cache_entry_size / sizeof(uint64_t); + r->l2_slice_size = l2_cache_entry_size / l2_entry_size(s); r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size, l2_cache_entry_size); r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size, @@ -1489,7 +1489,7 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options, bs->encrypted = true; } - s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ + s->l2_bits = s->cluster_bits - ctz32(l2_entry_size(s)); s->l2_size = 1 << s->l2_bits; /* 2^(s->refcount_order - 3) is the refcount width in bytes */ s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); @@ -4238,7 +4238,7 @@ static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset, * preallocation. All that matters is that we will not have to allocate * new refcount structures for them.) */ nb_new_l2_tables = DIV_ROUND_UP(nb_new_data_clusters, - s->cluster_size / sizeof(uint64_t)); + s->cluster_size / l2_entry_size(s)); /* The cluster range may not be aligned to L2 boundaries, so add one L2 * table for a potential head/tail */ nb_new_l2_tables++; diff --git a/block/qcow2.h b/block/qcow2.h index 4fe31adfd3..46b351229a 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -80,6 +80,10 @@ #define QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER 32 +/* Size of normal and extended L2 entries */ +#define L2E_SIZE_NORMAL (sizeof(uint64_t)) +#define L2E_SIZE_EXTENDED (sizeof(uint64_t) * 2) + #define MIN_CLUSTER_BITS 9 #define MAX_CLUSTER_BITS 21 @@ -521,6 +525,11 @@ static inline bool has_subclusters(BDRVQcow2State *s) return false; } +static inline size_t l2_entry_size(BDRVQcow2State *s) +{ + return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL; +} + static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice, int idx) {