Re: [PATCH v2 1/6] gnttab: eliminate several explicit version checks

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

On 15/06/15 13:24, Jan Beulich wrote:
> @@ -1977,10 +1969,6 @@ __acquire_grant_for_copy(
>  
>      read_lock(&rgt->lock);
>  
> -    if ( rgt->gt_version == 0 )
> -        PIN_FAIL(gt_unlock_out, GNTST_general_error,
> -                 "remote grant table not ready\n");
> -
>      if ( unlikely(gref >= nr_grant_entries(rgt)) )
>          PIN_FAIL(gt_unlock_out, GNTST_bad_gntref,
>                   "Bad grant reference %ld\n", gref);
> @@ -2482,19 +2470,15 @@ gnttab_set_version(XEN_GUEST_HANDLE_PARA
>         change the version number, except for the first 8 entries which
>         are allowed to be in use (xenstore/xenconsole keeps them mapped).
>         (You need to change the version number for e.g. kexec.) */
> -    if ( gt->gt_version != 0 )
> +    for ( i = GNTTAB_NR_RESERVED_ENTRIES; i < nr_grant_entries(gt); i++ )
>      {
> -        for ( i = GNTTAB_NR_RESERVED_ENTRIES; i < nr_grant_entries(gt); i++ )
> +        if ( read_atomic(&_active_entry(gt, i).pin) != 0 )
>          {
> -            if ( read_atomic(&_active_entry(gt, i).pin) != 0 )
> -            {
> -                gdprintk(XENLOG_WARNING,
> -                         "tried to change grant table version from %d to %d, but some grant entries still in use\n",
> -                         gt->gt_version,
> -                         op.version);
> -                res = -EBUSY;
> -                goto out_unlock;
> -            }
> +            gdprintk(XENLOG_WARNING,
> +                     "tried to change grant table version from %d to %d, but some grant entries still in use\n",
> +                     gt->gt_version, op.version);

As you are moving this printf, both %d should be %u.

As for the main part of the change, Reviewed-by: Andrew Cooper
<andrew.cooper3@citrix.com>