Commit 0076bc0c authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Anthony Liguori
Browse files

block: prevent multiwrite_merge from creating too large iovecs 



If we go over the maximum number of iovecs support by syscall we get
back EINVAL from the kernel which translate to I/O errors for the guest.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent 1d44952f

block.c

+4 −0
Original line number Diff line number Diff line
@@ -1689,6 +1689,10 @@ static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, 
            merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);

        }



        if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {

            merge = 0;

        }



        if (merge) {

            size_t size;

            QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));