stream: move is_allocated_above to block.c
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index 7547051..c07ff39 100644
--- a/block.c
+++ b/block.c
@@ -2569,6 +2569,55 @@
return data.ret;
}
+/*
+ * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
+ *
+ * Return true if the given sector is allocated in any image between
+ * BASE and TOP (inclusive). BASE can be NULL to check if the given
+ * sector is allocated in any image of the chain. Return false otherwise.
+ *
+ * 'pnum' is set to the number of sectors (including and immediately following
+ * the specified sector) that are known to be in the same
+ * allocated/unallocated state.
+ *
+ */
+int coroutine_fn bdrv_co_is_allocated_above(BlockDriverState *top,
+ BlockDriverState *base,
+ int64_t sector_num,
+ int nb_sectors, int *pnum)
+{
+ BlockDriverState *intermediate;
+ int ret, n = nb_sectors;
+
+ intermediate = top;
+ while (intermediate && intermediate != base) {
+ int pnum_inter;
+ ret = bdrv_co_is_allocated(intermediate, sector_num, nb_sectors,
+ &pnum_inter);
+ if (ret < 0) {
+ return ret;
+ } else if (ret) {
+ *pnum = pnum_inter;
+ return 1;
+ }
+
+ /*
+ * [sector_num, nb_sectors] is unallocated on top but intermediate
+ * might have
+ *
+ * [sector_num+x, nr_sectors] allocated.
+ */
+ if (n > pnum_inter) {
+ n = pnum_inter;
+ }
+
+ intermediate = intermediate->backing_hd;
+ }
+
+ *pnum = n;
+ return 0;
+}
+
BlockInfoList *qmp_query_block(Error **errp)
{
BlockInfoList *head = NULL, *cur_item = NULL;
