Re: [Qemu-devel] [PATCH 07/20] iscsi: Handle failure for potentially large allocations

[Paolo Bonzini <pbonzini@redhat.com>]

Il 21/05/2014 18:28, Kevin Wolf ha scritto:
> 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 iscsi block driver.
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block/iscsi.c | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/block/iscsi.c b/block/iscsi.c
> index 52355b8..c047ca8 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -296,7 +296,10 @@ static int coroutine_fn iscsi_co_writev(BlockDriverState *bs,
>          data = iov->iov[0].iov_base;
>      } else {
>          size_t size = MIN(nb_sectors * BDRV_SECTOR_SIZE, iov->size);
> -        buf = g_malloc(size);
> +        buf = g_try_malloc(size);
> +        if (buf == NULL) {
> +            return -ENOMEM;
> +        }
>          qemu_iovec_to_buf(iov, 0, buf, size);
>          data = buf;
>      }
> @@ -550,7 +553,11 @@ static BlockDriverAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
>  #else
>              struct iovec *iov = (struct iovec *)acb->ioh->dxferp;
>
> -            acb->buf = g_malloc(acb->ioh->dxfer_len);
> +            acb->buf = g_try_malloc(acb->ioh->dxfer_len);
> +            if (acb->buf == NULL) {
> +                qemu_aio_release(acb);
> +                return NULL;
> +            }
>              data.data = acb->buf;
>              data.size = iov_to_buf(iov, acb->ioh->iovec_count, 0,
>                                     acb->buf, acb->ioh->dxfer_len);
> @@ -823,7 +830,10 @@ coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
>      nb_blocks = sector_qemu2lun(nb_sectors, iscsilun);
>
>      if (iscsilun->zeroblock == NULL) {
> -        iscsilun->zeroblock = g_malloc0(iscsilun->block_size);
> +        iscsilun->zeroblock = g_try_malloc0(iscsilun->block_size);
> +        if (iscsilun->zeroblock == NULL) {
> +            return -ENOMEM;
> +        }
>      }
>
>      iscsi_co_init_iscsitask(iscsilun, &iTask);
>

Acked-by: Paolo Bonzini <pbonzini@redhat.com>