Keep track of the active L2 tables in the metadata list to protect them against accidental modifications.
Signed-off-by: Max Reitz <mre...@redhat.com> --- block/qcow2-cluster.c | 2 ++ block/qcow2-refcount.c | 6 ++++++ block/qcow2-snapshot.c | 21 +++++++++++++++++++++ block/qcow2.c | 8 +++++++- 4 files changed, 36 insertions(+), 1 deletion(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index bc93c00..88dd4f0 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -288,6 +288,8 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table) goto fail; } + qcow2_metadata_list_enter(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + *table = l2_table; trace_qcow2_l2_allocate_done(bs, l1_index, 0); return 0; diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index a785027..6255ed2 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1043,6 +1043,12 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs, if (addend != 0) { refcount = qcow2_update_cluster_refcount(bs, l2_offset >> s->cluster_bits, addend, QCOW2_DISCARD_SNAPSHOT); + if (addend < 0) { + if (!l1_allocated) { + qcow2_metadata_list_remove(bs, l2_offset, 1, + QCOW2_OL_ACTIVE_L2); + } + } } else { refcount = qcow2_get_refcount(bs, l2_offset >> s->cluster_bits); } diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c index 41ea053..d83a939 100644 --- a/block/qcow2-snapshot.c +++ b/block/qcow2-snapshot.c @@ -561,6 +561,13 @@ int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id) g_free(sn_l1_table); sn_l1_table = NULL; + for (i = 0; i < s->l1_size; i++) { + uint64_t l2_offset = s->l1_table[i] & L1E_OFFSET_MASK; + if (l2_offset) { + qcow2_metadata_list_enter(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + } + } + /* * Update QCOW_OFLAG_COPIED in the active L1 table (it may have changed * when we decreased the refcount of the old snapshot. @@ -725,6 +732,13 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs, sizeof(uint64_t)), QCOW2_OL_ACTIVE_L1); + for (i = 0; i < s->l1_size; i++) { + uint64_t l2_offset = s->l1_table[i] & L1E_OFFSET_MASK; + if (l2_offset) { + qcow2_metadata_list_remove(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + } + } + /* Switch the L1 table */ qemu_vfree(s->l1_table); @@ -741,5 +755,12 @@ int qcow2_snapshot_load_tmp(BlockDriverState *bs, sizeof(uint64_t)), QCOW2_OL_ACTIVE_L1); + for (i = 0; i < s->l1_size; i++) { + uint64_t l2_offset = s->l1_table[i] & L1E_OFFSET_MASK; + if (l2_offset) { + qcow2_metadata_list_enter(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + } + } + return 0; } diff --git a/block/qcow2.c b/block/qcow2.c index f285555..8225ca2 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -851,8 +851,14 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, error_setg_errno(errp, -ret, "Could not read L1 table"); goto fail; } - for(i = 0;i < s->l1_size; i++) { + for (i = 0; i < s->l1_size; i++) { + uint64_t l2_offset; + be64_to_cpus(&s->l1_table[i]); + l2_offset = s->l1_table[i] & L1E_OFFSET_MASK; + if (l2_offset) { + qcow2_metadata_list_enter(bs, l2_offset, 1, QCOW2_OL_ACTIVE_L2); + } } } -- 2.1.0