Signed-off-by: Peter Lieven <p...@kamp.de> Reviewed-by: Ronnie Sahlberg <ronniesahlb...@gmail.com> --- block.c | 4 ++++ include/block/block_int.h | 3 +++ 2 files changed, 7 insertions(+)
diff --git a/block.c b/block.c index c5a251c..26806e0 100644 --- a/block.c +++ b/block.c @@ -541,6 +541,7 @@ 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; @@ -555,6 +556,9 @@ 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(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