From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Stefan Reiter Date: Tue, 2 Mar 2021 16:11:54 +0100 Subject: [PATCH] block/io: accept NULL qiov in bdrv_pad_request Some operations, e.g. block-stream, perform reads while discarding the results (only copy-on-read matters). In this case they will pass NULL as the target QEMUIOVector, which will however trip bdrv_pad_request, since it wants to extend its passed vector. Simply check for NULL and do nothing, there's no reason to pad the target if it will be discarded anyway. Signed-off-by: Thomas Lamprecht --- block/io.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/block/io.c b/block/io.c index 83d1b1dfdc..24a3c84c93 100644 --- a/block/io.c +++ b/block/io.c @@ -1710,6 +1710,10 @@ static int bdrv_pad_request(BlockDriverState *bs, int sliced_niov; size_t sliced_head, sliced_tail; + if (!qiov) { + return 0; + } + /* Should have been checked by the caller already */ ret = bdrv_check_request32(*offset, *bytes, *qiov, *qiov_offset); if (ret < 0) {