If every BlockDriver were to implement bdrv_get_allocated_file_size(),
there are basically three ways it would be handled:
(1) For protocol drivers: Figure out the actual allocated file size in
some protocol-specific way
(2) For protocol drivers: If that is not possible (or we just have not
bothered to implement it yet), return -ENOTSUP
(3) For drivers with children: Return the sum of some or all their
children's sizes
For the drivers we have, case (3) boils down to either:
(a) The sum of all children's sizes
(b) The size of the primary child
(2), (3a) and (3b) can be implemented generically, so this patch adds
such generic implementations for drivers to use.
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
include/block/block_int.h | 5 ++++
block.c | 51 +++++++++++++++++++++++++++++++++++++++
2 files changed, 56 insertions(+)
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 5da793bfc3..c963ee9f28 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -1318,6 +1318,11 @@ int coroutine_fn
bdrv_co_block_status_from_backing(BlockDriverState *bs,
int64_t *pnum,
int64_t *map,
BlockDriverState **file);
+
+int64_t bdrv_sum_allocated_file_size(BlockDriverState *bs);
+int64_t bdrv_primary_allocated_file_size(BlockDriverState *bs);
+int64_t bdrv_notsup_allocated_file_size(BlockDriverState *bs);
+
const char *bdrv_get_parent_name(const BlockDriverState *bs);
void blk_dev_change_media_cb(BlockBackend *blk, bool load, Error **errp);
bool blk_dev_has_removable_media(BlockBackend *blk);
diff --git a/block.c b/block.c
index 1c71ecab7c..fc01ce90b3 100644
--- a/block.c
+++ b/block.c
@@ -5003,6 +5003,57 @@ int64_t bdrv_get_allocated_file_size(BlockDriverState
*bs)
return -ENOTSUP;
}
+/**
+ * Implementation of BlockDriver.bdrv_get_allocated_file_size() for
+ * block drivers that want it to sum all children they store data on.
+ * (This excludes backing children.)
+ */
+int64_t bdrv_sum_allocated_file_size(BlockDriverState *bs)
+{
+ BdrvChild *child;
+ int64_t child_size, sum = 0;
+
+ QLIST_FOREACH(child, &bs->children, next) {
+ if (child->role & (BDRV_CHILD_DATA | BDRV_CHILD_METADATA |
+ BDRV_CHILD_FILTERED))
+ {
+ child_size = bdrv_get_allocated_file_size(child->bs);
+ if (child_size < 0) {
+ return child_size;
+ }
+ sum += child_size;
+ }
+ }
+
+ return sum;
+}
+
+/**
+ * Implementation of BlockDriver.bdrv_get_allocated_file_size() for
+ * block drivers that want it to return only the size of a node's
+ * primary child.
+ */
+int64_t bdrv_primary_allocated_file_size(BlockDriverState *bs)
+{
+ BlockDriverState *primary_bs;
+
+ primary_bs = bdrv_primary_bs(bs);
+ if (!primary_bs) {
+ return -ENOTSUP;
+ }
+
+ return bdrv_get_allocated_file_size(primary_bs);
+}
+
+/**
+ * Implementation of BlockDriver.bdrv_get_allocated_file_size() for
+ * protocol block drivers that just do not support it.
+ */
+int64_t bdrv_notsup_allocated_file_size(BlockDriverState *bs)
+{
+ return -ENOTSUP;
+}
+
/*
* bdrv_measure:
* @drv: Format driver