[libvirt] [PATCH] Invert logic for checking for QEMU disk cache options

[Cole Robinson]

On 07/27/2010 06:23 AM, Daniel P. Berrange wrote:
> QEMU has had two different syntax for disk cache options
> 
>  Old: on|off
>  New: writeback|writethrough|none
> 
> QEMU recently added another 'unsafe' option which broke the
> libvirt check. We can avoid this & future breakage, if we
> do a negative check for the old syntax, instead of a positive
> check for the new syntax
> 
> * src/qemu/qemu_conf.c: Invert cache option check
> ---
>  src/qemu/qemu_conf.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
> index 0dbab48..db60ca3 100644
> --- a/src/qemu/qemu_conf.c
> +++ b/src/qemu/qemu_conf.c
> @@ -1170,7 +1170,8 @@ static unsigned long long qemudComputeCmdFlags(const char *help,
>          flags |= QEMUD_CMD_FLAG_DOMID;
>      if (strstr(help, "-drive")) {
>          flags |= QEMUD_CMD_FLAG_DRIVE;
> -        if (strstr(help, "cache=writethrough|writeback|none"))
> +        if (strstr(help, "cache=") &&
> +            !strstr(help, "cache=on|off"))
>              flags |= QEMUD_CMD_FLAG_DRIVE_CACHE_V2;
>          if (strstr(help, "format="))
>              flags |= QEMUD_CMD_FLAG_DRIVE_FORMAT;

ACK

- Cole