From 301db7c2dd769d48e97c9a766520f8affff76cd7 Mon Sep 17 00:00:00 2001 From: Ryan Harper Date: Mon, 7 Mar 2011 10:01:04 -0600 Subject: [PATCH] Don't allow multiwrites against a block device without underlying medium If the block device has been closed, we no longer have a medium to submit IO against, check for this before submitting io. This prevents a segfault further in the code where we dereference elements of the block driver. Signed-off-by: Ryan Harper Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/block.c b/block.c index 0559d835a2..c8e2f97614 100644 --- a/block.c +++ b/block.c @@ -2398,6 +2398,14 @@ int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) MultiwriteCB *mcb; int i; + /* don't submit writes if we don't have a medium */ + if (bs->drv == NULL) { + for (i = 0; i < num_reqs; i++) { + reqs[i].error = -ENOMEDIUM; + } + return -1; + } + if (num_reqs == 0) { return 0; } -- 2.30.2