Signed-off-by: Peter Lieven <p...@kamp.de>
---
block.c | 4 ++++
include/block/block_int.h | 3 +++
2 files changed, 7 insertions(+)
diff --git a/block.c b/block.c
index 27533f3..0fbf916 100644
--- a/block.c
+++ b/block.c
@@ -536,6 +536,7 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
return;
}
bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length;
+ bs->bl.max_transfer_length = bs->file->bl.max_transfer_length;
bs->bl.opt_mem_alignment = bs->file->bl.opt_mem_alignment;
} else {
bs->bl.opt_mem_alignment = 512;
@@ -550,6 +551,9 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
bs->bl.opt_transfer_length =
MAX(bs->bl.opt_transfer_length,
bs->backing_hd->bl.opt_transfer_length);
+ bs->bl.max_transfer_length =
+ MIN_NON_ZERO(bs->bl.max_transfer_length,
+ bs->backing_hd->bl.max_transfer_length);
bs->bl.opt_mem_alignment =
MAX(bs->bl.opt_mem_alignment,
bs->backing_hd->bl.opt_mem_alignment);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 8d86a6c..b13a10a 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -289,6 +289,9 @@ typedef struct BlockLimits {
/* optimal transfer length in sectors */
int opt_transfer_length;
+ /* maximal transfer length in sectors */
+ int max_transfer_length;
+
/* memory alignment so that no bounce buffer is needed */
size_t opt_mem_alignment;
} BlockLimits;
--
1.7.9.5
