From ca62dd5c2b1897a187c841371fef88263639ce0d Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Mon, 5 Feb 2018 16:33:26 +0200 Subject: [PATCH] qcow2: Prepare qcow2_update_snapshot_refcount() for adding L2 slice support Adding support for L2 slices to qcow2_update_snapshot_refcount() needs (among other things) an extra loop that iterates over all slices of each L2 table. Putting all changes in one patch would make it hard to read because all semantic changes would be mixed with pure indentation changes. To make things easier this patch simply creates a new block and changes the indentation of all lines of code inside it. Thus, all modifications in this patch are cosmetic. There are no semantic changes and no variables are renamed yet. The next patch will take care of that. Signed-off-by: Alberto Garcia Reviewed-by: Eric Blake Reviewed-by: Max Reitz Message-id: 8ffaa5e55bd51121f80e498f4045b64902a94293.1517840877.git.berto@igalia.com Signed-off-by: Max Reitz --- block/qcow2-refcount.c | 144 +++++++++++++++++++++-------------------- 1 file changed, 75 insertions(+), 69 deletions(-) diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 9df380d52c..dfa28301c4 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1236,90 +1236,96 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs, goto fail; } - ret = qcow2_cache_get(bs, s->l2_table_cache, l2_offset, - (void**) &l2_table); - if (ret < 0) { - goto fail; - } + { + ret = qcow2_cache_get(bs, s->l2_table_cache, + l2_offset, + (void **) &l2_table); + if (ret < 0) { + goto fail; + } - for (j = 0; j < s->l2_size; j++) { - uint64_t cluster_index; - uint64_t offset; - - entry = be64_to_cpu(l2_table[j]); - old_entry = entry; - entry &= ~QCOW_OFLAG_COPIED; - offset = entry & L2E_OFFSET_MASK; - - switch (qcow2_get_cluster_type(entry)) { - case QCOW2_CLUSTER_COMPRESSED: - nb_csectors = ((entry >> s->csize_shift) & - s->csize_mask) + 1; - if (addend != 0) { - ret = update_refcount(bs, - (entry & s->cluster_offset_mask) & ~511, + for (j = 0; j < s->l2_size; j++) { + uint64_t cluster_index; + uint64_t offset; + + entry = be64_to_cpu(l2_table[j]); + old_entry = entry; + entry &= ~QCOW_OFLAG_COPIED; + offset = entry & L2E_OFFSET_MASK; + + switch (qcow2_get_cluster_type(entry)) { + case QCOW2_CLUSTER_COMPRESSED: + nb_csectors = ((entry >> s->csize_shift) & + s->csize_mask) + 1; + if (addend != 0) { + ret = update_refcount( + bs, (entry & s->cluster_offset_mask) & ~511, nb_csectors * 512, abs(addend), addend < 0, QCOW2_DISCARD_SNAPSHOT); - if (ret < 0) { + if (ret < 0) { + goto fail; + } + } + /* compressed clusters are never modified */ + refcount = 2; + break; + + case QCOW2_CLUSTER_NORMAL: + case QCOW2_CLUSTER_ZERO_ALLOC: + if (offset_into_cluster(s, offset)) { + qcow2_signal_corruption( + bs, true, -1, -1, "Cluster " + "allocation offset %#" PRIx64 + " unaligned (L2 offset: %#" + PRIx64 ", L2 index: %#x)", + offset, l2_offset, j); + ret = -EIO; goto fail; } - } - /* compressed clusters are never modified */ - refcount = 2; - break; - - case QCOW2_CLUSTER_NORMAL: - case QCOW2_CLUSTER_ZERO_ALLOC: - if (offset_into_cluster(s, offset)) { - qcow2_signal_corruption(bs, true, -1, -1, "Cluster " - "allocation offset %#" PRIx64 - " unaligned (L2 offset: %#" - PRIx64 ", L2 index: %#x)", - offset, l2_offset, j); - ret = -EIO; - goto fail; - } - cluster_index = offset >> s->cluster_bits; - assert(cluster_index); - if (addend != 0) { - ret = qcow2_update_cluster_refcount(bs, - cluster_index, abs(addend), addend < 0, - QCOW2_DISCARD_SNAPSHOT); + cluster_index = offset >> s->cluster_bits; + assert(cluster_index); + if (addend != 0) { + ret = qcow2_update_cluster_refcount( + bs, cluster_index, abs(addend), addend < 0, + QCOW2_DISCARD_SNAPSHOT); + if (ret < 0) { + goto fail; + } + } + + ret = qcow2_get_refcount(bs, cluster_index, &refcount); if (ret < 0) { goto fail; } - } + break; - ret = qcow2_get_refcount(bs, cluster_index, &refcount); - if (ret < 0) { - goto fail; - } - break; - - case QCOW2_CLUSTER_ZERO_PLAIN: - case QCOW2_CLUSTER_UNALLOCATED: - refcount = 0; - break; + case QCOW2_CLUSTER_ZERO_PLAIN: + case QCOW2_CLUSTER_UNALLOCATED: + refcount = 0; + break; - default: - abort(); - } + default: + abort(); + } - if (refcount == 1) { - entry |= QCOW_OFLAG_COPIED; - } - if (entry != old_entry) { - if (addend > 0) { - qcow2_cache_set_dependency(bs, s->l2_table_cache, - s->refcount_block_cache); + if (refcount == 1) { + entry |= QCOW_OFLAG_COPIED; + } + if (entry != old_entry) { + if (addend > 0) { + qcow2_cache_set_dependency(bs, s->l2_table_cache, + s->refcount_block_cache); + } + l2_table[j] = cpu_to_be64(entry); + qcow2_cache_entry_mark_dirty(s->l2_table_cache, + l2_table); } - l2_table[j] = cpu_to_be64(entry); - qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table); } - } - qcow2_cache_put(s->l2_table_cache, (void **) &l2_table); + qcow2_cache_put(s->l2_table_cache, (void **) &l2_table); + + } if (addend != 0) { ret = qcow2_update_cluster_refcount(bs, l2_offset >> -- GitLab