diff options
| -rw-r--r-- | block/qcow2-cluster.c | 94 |
1 files changed, 28 insertions, 66 deletions
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 5687a4b15b..df0b2c9cec 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1613,20 +1613,12 @@ fail: * Expands all zero clusters in a specific L1 table (or deallocates them, for * non-backed non-pre-allocated zero clusters). * - * expanded_clusters is a bitmap where every bit corresponds to one cluster in - * the image file; a bit gets set if the corresponding cluster has been used for - * zero expansion (i.e., has been filled with zeroes and is referenced from an - * L2 table). nb_clusters contains the total cluster count of the image file, - * i.e., the number of bits in expanded_clusters. - * * l1_entries and *visited_l1_entries are used to keep track of progress for * status_cb(). l1_entries contains the total number of L1 entries and * *visited_l1_entries counts all visited L1 entries. */ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, - int l1_size, uint8_t **expanded_clusters, - uint64_t *nb_clusters, - int64_t *visited_l1_entries, + int l1_size, int64_t *visited_l1_entries, int64_t l1_entries, BlockDriverAmendStatusCB *status_cb) { @@ -1648,6 +1640,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, for (i = 0; i < l1_size; i++) { uint64_t l2_offset = l1_table[i] & L1E_OFFSET_MASK; bool l2_dirty = false; + int l2_refcount; if (!l2_offset) { /* unallocated */ @@ -1671,33 +1664,19 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, goto fail; } + l2_refcount = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits); + if (l2_refcount < 0) { + ret = l2_refcount; + goto fail; + } + for (j = 0; j < s->l2_size; j++) { uint64_t l2_entry = be64_to_cpu(l2_table[j]); - int64_t offset = l2_entry & L2E_OFFSET_MASK, cluster_index; + int64_t offset = l2_entry & L2E_OFFSET_MASK; int cluster_type = qcow2_get_cluster_type(l2_entry); bool preallocated = offset != 0; - if (cluster_type == QCOW2_CLUSTER_NORMAL) { - cluster_index = offset >> s->cluster_bits; - assert((cluster_index >= 0) && (cluster_index < *nb_clusters)); - if ((*expanded_clusters)[cluster_index / 8] & - (1 << (cluster_index % 8))) { - /* Probably a shared L2 table; this cluster was a zero - * cluster which has been expanded, its refcount - * therefore most likely requires an update. */ - ret = qcow2_update_cluster_refcount(bs, cluster_index, 1, - QCOW2_DISCARD_NEVER); - if (ret < 0) { - goto fail; - } - /* Since we just increased the refcount, the COPIED flag may - * no longer be set. */ - l2_table[j] = cpu_to_be64(l2_entry & ~QCOW_OFLAG_COPIED); - l2_dirty = true; - } - continue; - } - else if (qcow2_get_cluster_type(l2_entry) != QCOW2_CLUSTER_ZERO) { + if (cluster_type != QCOW2_CLUSTER_ZERO) { continue; } @@ -1715,6 +1694,19 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, ret = offset; goto fail; } + + if (l2_refcount > 1) { + /* For shared L2 tables, set the refcount accordingly (it is + * already 1 and needs to be l2_refcount) */ + ret = qcow2_update_cluster_refcount(bs, + offset >> s->cluster_bits, l2_refcount - 1, + QCOW2_DISCARD_OTHER); + if (ret < 0) { + qcow2_free_clusters(bs, offset, s->cluster_size, + QCOW2_DISCARD_OTHER); + goto fail; + } + } } ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size); @@ -1736,29 +1728,12 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, goto fail; } - l2_table[j] = cpu_to_be64(offset | QCOW_OFLAG_COPIED); - l2_dirty = true; - - cluster_index = offset >> s->cluster_bits; - - if (cluster_index >= *nb_clusters) { - uint64_t old_bitmap_size = (*nb_clusters + 7) / 8; - uint64_t new_bitmap_size; - /* The offset may lie beyond the old end of the underlying image - * file for growable files only */ - assert(bs->file->growable); - *nb_clusters = size_to_clusters(s, bs->file->total_sectors * - BDRV_SECTOR_SIZE); - new_bitmap_size = (*nb_clusters + 7) / 8; - *expanded_clusters = g_realloc(*expanded_clusters, - new_bitmap_size); - /* clear the newly allocated space */ - memset(&(*expanded_clusters)[old_bitmap_size], 0, - new_bitmap_size - old_bitmap_size); + if (l2_refcount == 1) { + l2_table[j] = cpu_to_be64(offset | QCOW_OFLAG_COPIED); + } else { + l2_table[j] = cpu_to_be64(offset); } - - assert((cluster_index >= 0) && (cluster_index < *nb_clusters)); - (*expanded_clusters)[cluster_index / 8] |= 1 << (cluster_index % 8); + l2_dirty = true; } if (is_active_l1) { @@ -1823,9 +1798,7 @@ int qcow2_expand_zero_clusters(BlockDriverState *bs, { BDRVQcowState *s = bs->opaque; uint64_t *l1_table = NULL; - uint64_t nb_clusters; int64_t l1_entries = 0, visited_l1_entries = 0; - uint8_t *expanded_clusters; int ret; int i, j; @@ -1836,16 +1809,7 @@ int qcow2_expand_zero_clusters(BlockDriverState *bs, } } - nb_clusters = size_to_clusters(s, bs->file->total_sectors * - BDRV_SECTOR_SIZE); - expanded_clusters = g_try_malloc0((nb_clusters + 7) / 8); - if (expanded_clusters == NULL) { - ret = -ENOMEM; - goto fail; - } - ret = expand_zero_clusters_in_l1(bs, s->l1_table, s->l1_size, - &expanded_clusters, &nb_clusters, &visited_l1_entries, l1_entries, status_cb); if (ret < 0) { @@ -1881,7 +1845,6 @@ int qcow2_expand_zero_clusters(BlockDriverState *bs, } ret = expand_zero_clusters_in_l1(bs, l1_table, s->snapshots[i].l1_size, - &expanded_clusters, &nb_clusters, &visited_l1_entries, l1_entries, status_cb); if (ret < 0) { @@ -1892,7 +1855,6 @@ int qcow2_expand_zero_clusters(BlockDriverState *bs, ret = 0; fail: - g_free(expanded_clusters); g_free(l1_table); return ret; } |