[libvirt] [PATCH 2/2] util: Produce friendlier error message to user

[John Ferlan]

On 09/30/2015 12:01 AM, Luyao Huang wrote:
> Commit 1c24cfe9 fix the problem in virNumaSetPagePoolSize,
> this patch just like it and fix the issue in another function.
> 
> when user use freepages and specify a invalid node or page size,
> will get error like this:
> 
>  # virsh freepages 0 1
>  error: Failed to open file '/sys/devices/system/node/node0/hugepages/hugepages-1kB/free_hugepages': No such file or directory
> 
> Add two checks to catch this and therefore produce much more
> friendlier error messages.
> 
> Signed-off-by: Luyao Huang <lhuang at redhat.com>
> ---
>  src/util/virnuma.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 

Perhaps the more entertaining part of this patch is/was it possible to
use "freepages 0 0"?  Before patch 1, before patch 2, after patch 2.

Based on the answer to the question below, I can adjust the commit
message (and code if necessary) a bit in order to remove the really long
line and make it flow better.

> diff --git a/src/util/virnuma.c b/src/util/virnuma.c
> index 8577bd8..c8beade 100644
> --- a/src/util/virnuma.c
> +++ b/src/util/virnuma.c
> @@ -560,6 +560,12 @@ virNumaGetHugePageInfo(int node,
>                                         page_size, "nr_hugepages") < 0)
>              goto cleanup;
>  
> +        if (!virFileExists(path)) {
> +            virReportError(VIR_ERR_OPERATION_FAILED, "%s",
> +                           _("page size or NUMA node not available"));
> +            goto cleanup;
> +        }
> +

Why is there no "if (node != -1 && !virNumaNodeIsAvailable(node)) {"
check prior to the virNumaGetHugePageInfoPath call?

<same for next change too>

John

>          if (virFileReadAll(path, 1024, &buf) < 0)
>              goto cleanup;
>  
> @@ -579,6 +585,12 @@ virNumaGetHugePageInfo(int node,
>                                         page_size, "free_hugepages") < 0)
>              goto cleanup;
>  
> +        if (!virFileExists(path)) {
> +            virReportError(VIR_ERR_OPERATION_FAILED, "%s",
> +                           _("page size or NUMA node not available"));
> +            goto cleanup;
> +        }
> +
>          if (virFileReadAll(path, 1024, &buf) < 0)
>              goto cleanup;
>  
>