Re: [Qemu-devel] [PATCH 7/8] iscsi: assert that sectors are aligned to LUN blocksize

[Paolo Bonzini <pbonzini@redhat.com>]

Il 22/06/2013 22:58, Peter Lieven ha scritto:
> if the blocksize of an iSCSI LUN is bigger than the BDRV_SECTOR_SIZE
> it is possible that sector_num or nb_sectors are not correctly
> alligned.
> 
> for now assert that there is no misalignment to avoid data
> corruption.

You should just fail to open the LUN instead.

Paolo

> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  block/iscsi.c |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/block/iscsi.c b/block/iscsi.c
> index 683692a..2c410b1 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -249,6 +249,7 @@ iscsi_aio_write16_cb(struct iscsi_context *iscsi, int status,
>  
>  static int64_t sector_qemu2lun(int64_t sector, IscsiLun *iscsilun)
>  {
> +    assert((sector * BDRV_SECTOR_SIZE) % iscsilun->block_size == 0);
>      return sector * BDRV_SECTOR_SIZE / iscsilun->block_size;
>  }
>  
> @@ -269,6 +270,8 @@ iscsi_aio_writev_acb(IscsiAIOCB *acb)
>      acb->status     = -EINPROGRESS;
>      acb->buf        = NULL;
>  
> +    assert((acb->nb_sectors * BDRV_SECTOR_SIZE) % acb->iscsilun->block_size == 0);
> +
>      /* this will allow us to get rid of 'buf' completely */
>      size = acb->nb_sectors * BDRV_SECTOR_SIZE;
>  
> @@ -618,6 +621,8 @@ static int iscsi_aio_discard_acb(IscsiAIOCB *acb) {
>      acb->buf        = NULL;
>  
>      list[0].lba = sector_qemu2lun(acb->sector_num, acb->iscsilun);
> +
> +    assert((acb->nb_sectors * BDRV_SECTOR_SIZE) % acb->iscsilun->block_size == 0);
>      list[0].num = acb->nb_sectors * BDRV_SECTOR_SIZE / acb->iscsilun->block_size;
>  
>      acb->task = iscsi_unmap_task(iscsi, acb->iscsilun->lun,
> @@ -947,6 +952,8 @@ coroutine_fn iscsi_co_write_zeroes(BlockDriverState *bs, int64_t sector_num,
>      iTask.complete = 0;
>      iTask.bs = bs;
>  
> +    assert((nb_sectors * BDRV_SECTOR_SIZE) % iscsilun->block_size == 0);
> +
>      list[0].lba = sector_qemu2lun(sector_num, iscsilun);
>      list[0].num = nb_sectors * BDRV_SECTOR_SIZE / iscsilun->block_size;
>  
>