Re: [Qemu-devel] [PATCH] block: prevent multiwrite_merge from creating too large iovecs

[Christoph Hellwig]

On Wed, Jan 20, 2010 at 12:37:51PM +0100, Kevin Wolf wrote:
> Am 19.01.2010 22:15, schrieb Christoph Hellwig:
> > 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: Christoph Hellwig <address@hidden>
> 
> Is this really enough? We don't check for IOV_MAX in any other place, so
> can't we get a too big request directly from virtio-blk?

Currently the virtqueue is limited to 1024 iovecs, but I plan to put in
some better infrastructure to deal with the queue limit.  For now this
patch fixes an issue that we see with real life setups.