Re: [Qemu-devel] [PATCH v4 14/21] raw-win32: Handle failure for potentially large allocations

[Kevin Wolf <kwolf@redhat.com>]

Am 05.06.2014 um 17:09 hat Benoît Canet geschrieben:
> The Thursday 05 Jun 2014 à 15:36:26 (+0200), Kevin Wolf wrote :
> > Some code in the block layer makes potentially huge allocations. Failure
> > is not completely unexpected there, so avoid aborting qemu and handle
> > out-of-memory situations gracefully.
> > 
> > This patch addresses the allocations in the raw-win32 block driver.
> > 
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> >  block/win32-aio.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/block/win32-aio.c b/block/win32-aio.c
> > index 5d1d199..b8320ce 100644
> > --- a/block/win32-aio.c
> > +++ b/block/win32-aio.c
> > @@ -138,7 +138,10 @@ BlockDriverAIOCB *win32_aio_submit(BlockDriverState *bs,
> >      waiocb->is_read = (type == QEMU_AIO_READ);
> >  
> >      if (qiov->niov > 1) {
> > -        waiocb->buf = qemu_blockalign(bs, qiov->size);
> > +        waiocb->buf = qemu_try_blockalign(bs, qiov->size);
> > +        if (waiocb->buf == NULL) {
> > +            goto out;
> > +        }
> >          if (type & QEMU_AIO_WRITE) {
> >              iov_to_buf(qiov->iov, qiov->niov, 0, waiocb->buf, qiov->size);
> >          }
> > @@ -167,6 +170,7 @@ BlockDriverAIOCB *win32_aio_submit(BlockDriverState *bs,
> >  
> >  out_dec_count:
> >      aio->count--;
> Isn't waiocb->buf leaked on this path ?

The already existing error path you mean? Looks like it, feel free to
send a patch.

Kevin

> > +out:
> >      qemu_aio_release(waiocb);
> >      return NULL;
> >  }
> > -- 
> > 1.8.3.1
> > 
> >