[libvirt] [PATCH] libvirt_iohelper: record the libvirt_iohelper's error message at virFileWrapperFdFree

[Michal Prívozník]

On 07/22/2018 03:40 AM, xinhua.Cao wrote:
> Currently iohelper's error log is recorded in virFileWrapperFdClose.
> In qemuDomainSaveMemory, it usually fails at qemuMigrationSrcToFile,
> and then goto cleanup, so the iohelper error log is not recorded,
> and so is the another placement. We now record the error log of
> iohelper by move it to the virFileWrapperFdFree record.
> There is another problem here, that is, virCommandWait is also not
> called, but I can't evaluate this impact. So no changes have been
> made here.
> ---
>  src/util/virfile.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/src/util/virfile.c b/src/util/virfile.c
> index 1faeebb..30456ab 100644
> --- a/src/util/virfile.c
> +++ b/src/util/virfile.c
> @@ -330,9 +330,6 @@ virFileWrapperFdClose(virFileWrapperFdPtr wfd)
>          return 0;
>  
>      ret = virCommandWait(wfd->cmd, NULL);
> -    if (wfd->err_msg && *wfd->err_msg)
> -        VIR_WARN("iohelper reports: %s", wfd->err_msg);
> -
>      return ret;
>  }
>  
> @@ -351,6 +348,9 @@ virFileWrapperFdFree(virFileWrapperFdPtr wfd)
>      if (!wfd)
>          return;
>  
> +    if (wfd->err_msg && *wfd->err_msg)
> +        VIR_WARN("iohelper reports: %s", wfd->err_msg);
> +
>      VIR_FREE(wfd->err_msg);
>  
>      virCommandFree(wfd->cmd);
> 

Makes sense. However, your patch lacks Signed-off-By line so I can't
push it. It's required according to contributor guidelines:

https://libvirt.org/hacking.html

And for the virCommandWait() - we should call virCommandAbort() in
virFileWrapperFdFree() to make sure no process is left behind. If
virCommandWait() is called then virCommandAbort() is a NO-OP. If it
isn't, then Abort() will kill iohelper.

Michal