Re: [PATCH 2/5] xc/tmem: Unchecked return value.

[Andrew Cooper <andrew.cooper3@citrix.com>]

On 25/11/13 17:00, Konrad Rzeszutek Wilk wrote:
> CID 1055045 complains that the return value needs checking.
>
> The tmem op is a flush call and there is no expectation
> right now of any return besides zero. But just in case
> this changes lets blow up.
>
> CC: Bob Liu <bob.liu@oracle.com>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> ---
>  tools/libxc/xc_domain_save.c | 6 ++++--
>  tools/libxc/xc_tmem.c        | 4 ++--
>  tools/libxc/xenctrl.h        | 2 +-
>  3 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c
> index 42c4752..c3f0f19 100644
> --- a/tools/libxc/xc_domain_save.c
> +++ b/tools/libxc/xc_domain_save.c
> @@ -2095,8 +2095,10 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter
>          goto copypages;
>      }
>  
> -    if ( tmem_saved != 0 && live )
> -        xc_tmem_save_done(xch, dom);
> +    if ( tmem_saved != 0 && live ) {
> +        if ( xc_tmem_save_done(xch, dom) )

These could be combined into a single if statement.

> +            DPRINTF("Warning - failed to flush tmem on originating server.");

Does this need to bail at this point then?

> +    }
>  
>      if ( live )
>      {
> diff --git a/tools/libxc/xc_tmem.c b/tools/libxc/xc_tmem.c
> index 0918615..df50ef5 100644
> --- a/tools/libxc/xc_tmem.c
> +++ b/tools/libxc/xc_tmem.c
> @@ -366,9 +366,9 @@ int xc_tmem_save_extra(xc_interface *xch, int dom, int io_fd, int field_marker)
>  }
>  
>  /* only called for live migration */
> -void xc_tmem_save_done(xc_interface *xch, int dom)
> +int xc_tmem_save_done(xc_interface *xch, int dom)
>  {
> -    xc_tmem_control(xch,0,TMEMC_SAVE_END,dom,0,0,0,NULL);
> +    return xc_tmem_control(xch,0,TMEMC_SAVE_END,dom,0,0,0,NULL);

As you are tweaking this, could you apply some coding style with spaces
following commas?

~Andrew

>  }
>  
>  /* restore routines */
> diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
> index 4ac6b8a..18d4f78 100644
> --- a/tools/libxc/xenctrl.h
> +++ b/tools/libxc/xenctrl.h
> @@ -1996,7 +1996,7 @@ int xc_tmem_control(xc_interface *xch,
>  int xc_tmem_auth(xc_interface *xch, int cli_id, char *uuid_str, int arg1);
>  int xc_tmem_save(xc_interface *xch, int dom, int live, int fd, int field_marker);
>  int xc_tmem_save_extra(xc_interface *xch, int dom, int fd, int field_marker);
> -void xc_tmem_save_done(xc_interface *xch, int dom);
> +int xc_tmem_save_done(xc_interface *xch, int dom);
>  int xc_tmem_restore(xc_interface *xch, int dom, int fd);
>  int xc_tmem_restore_extra(xc_interface *xch, int dom, int fd);
>