From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Campbell <ian.campbell@citrix.com>
Subject: Re: [PATCH for-4.6 02/13] libxl: properly clean up
 array in libxl_list_cpupool failure path
Date: Thu, 23 Jul 2015 10:22:02 +0100
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To: Wei Liu <wei.liu2@citrix.com>, Xen-devel <xen-devel@lists.xenproject.org>
Cc: Dario Faggioli <dario.faggioli@citrix.com>, Ian Jackson <Ian.Jackson@eu.citrix.com>
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On Thu, 2015-07-23 at 08:59 +0100, Wei Liu wrote:
> Document how cpupool_info works.  Distinguish success (ERROR_FAIL +
> ENOENT) vs failure in libxl_list_cpupool and properly clean up the 
> array
> in failure path.
> 
> Also switch to libxl__realloc and call libxl_cpupool_{init,dispose}
> where appropriate.
> 
> There is change of behaviour. Previously if memory allocation fails 
> the
> said function returns NULL. Now memory allocation failure is fatal. 
> This
> is in line with how we deal with memory allocation failure in other
> places in libxl though.

I think this function would benefit from making the out: label be the
error path and the success case just a return ptr (just before the
label).

Then your error handling for cpupool_info would become
            libxl_cpupoolinfo_dispose(&info);
            if (errno != ENOENT) goto out;
            break;

and the "if (failed)" block would be at the out label (without the
iff).

Such splitting of the success/failure case is allowed if the only
shared code would be the GC_FREE, which is the case here.

Ian.