+static int coroutine_fn
+qcow2_co_copy_range_from(BlockDriverState *bs,
+ BdrvChild *src, uint64_t src_offset,
+ BdrvChild *dst, uint64_t dst_offset,
+ uint64_t bytes, BdrvRequestFlags flags)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int ret;
+ unsigned int cur_bytes; /* number of bytes in current iteration */
+ BdrvChild *child = NULL;
+ BdrvRequestFlags cur_flags;
+
+ assert(!bs->encrypted);
+ qemu_co_mutex_lock(&s->lock);
+
+ while (bytes != 0) {
+ uint64_t copy_offset = 0;
+ /* prepare next request */
+ cur_bytes = MIN(bytes, INT_MAX);
+ cur_flags = flags;
+
+ ret = qcow2_get_cluster_offset(bs, src_offset, &cur_bytes, ©_offset);
+ if (ret < 0) {
+ goto out;
+ }
+
+ switch (ret) {
+ case QCOW2_CLUSTER_UNALLOCATED:
+ if (bs->backing && bs->backing->bs) {
+ int64_t backing_length = bdrv_getlength(bs->backing->bs);
+ if (src_offset >= backing_length) {
+ cur_flags |= BDRV_REQ_ZERO_WRITE;
+ } else {
+ child = bs->backing;
+ cur_bytes = MIN(cur_bytes, backing_length - src_offset);
+ copy_offset = src_offset;
+ }
+ } else {
+ cur_flags |= BDRV_REQ_ZERO_WRITE;
+ }
+ break;
+
+ case QCOW2_CLUSTER_ZERO_PLAIN:
+ case QCOW2_CLUSTER_ZERO_ALLOC:
+ cur_flags |= BDRV_REQ_ZERO_WRITE;
+ break;
+
+ case QCOW2_CLUSTER_COMPRESSED:
+ ret = -ENOTSUP;
+ goto out;
+
+ case QCOW2_CLUSTER_NORMAL:
+ child = bs->file;
+ copy_offset += offset_into_cluster(s, src_offset);
+ if ((copy_offset & 511) != 0) {
+ ret = -EIO;
+ goto out;
+ }
+ break;
+
+ default:
+ abort();
+ }
+ qemu_co_mutex_unlock(&s->lock);
+ ret = bdrv_co_copy_range_from(child,
+ copy_offset,
+ dst, dst_offset,
+ cur_bytes, cur_flags);
+ qemu_co_mutex_lock(&s->lock);
+ if (ret < 0) {
+ goto out;
+ }
+
+ bytes -= cur_bytes;
+ src_offset += cur_bytes;
+ dst_offset += cur_bytes;
+ }
+ ret = 0;
+
+out:
+ qemu_co_mutex_unlock(&s->lock);
+ return ret;
+}
+
+static int coroutine_fn
+qcow2_co_copy_range_to(BlockDriverState *bs,
+ BdrvChild *src, uint64_t src_offset,
+ BdrvChild *dst, uint64_t dst_offset,
+ uint64_t bytes, BdrvRequestFlags flags)
+{
+ BDRVQcow2State *s = bs->opaque;
+ int offset_in_cluster;
+ int ret;
+ unsigned int cur_bytes; /* number of sectors in current iteration */
+ uint64_t cluster_offset;
+ QCowL2Meta *l2meta = NULL;
+
+ assert(!bs->encrypted);
+ s->cluster_cache_offset = -1; /* disable compressed cache */
+
+ qemu_co_mutex_lock(&s->lock);
+
+ while (bytes != 0) {
+
+ l2meta = NULL;
+
+ offset_in_cluster = offset_into_cluster(s, dst_offset);
+ cur_bytes = MIN(bytes, INT_MAX);
+
+ /* TODO:
+ * If src->bs == dst->bs, we could simply copy by incrementing
+ * the refcnt, without copying user data.
+ * Or if src->bs == dst->bs->backing->bs, we could copy by discarding. */
+ ret = qcow2_alloc_cluster_offset(bs, dst_offset, &cur_bytes,
+ &cluster_offset, &l2meta);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ assert((cluster_offset & 511) == 0);
+
+ ret = qcow2_pre_write_overlap_check(bs, 0,
+ cluster_offset + offset_in_cluster, cur_bytes);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ qemu_co_mutex_unlock(&s->lock);
+ ret = bdrv_co_copy_range_to(src, src_offset,
+ bs->file,
+ cluster_offset + offset_in_cluster,
+ cur_bytes, flags);
+ qemu_co_mutex_lock(&s->lock);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = qcow2_handle_l2meta(bs, &l2meta, true);
+ if (ret) {
+ goto fail;
+ }
+
+ bytes -= cur_bytes;
+ src_offset += cur_bytes;
+ dst_offset += cur_bytes;
+ }
+ ret = 0;
+
+fail:
+ qcow2_handle_l2meta(bs, &l2meta, false);
+
+ qemu_co_mutex_unlock(&s->lock);
+
+ trace_qcow2_writev_done_req(qemu_coroutine_self(), ret);
+
+ return ret;
+}
+
+static int coroutine_fn qcow2_co_truncate(BlockDriverState *bs, int64_t offset,
+ PreallocMode prealloc, Error **errp)
projects / qemu.git / blobdiff