Re: [libvirt] [PATCH 10/11] util: Introduce virGetFCHostNameByFabricWWN
On 01/02/2017 09:51 AM, Ján Tomko wrote:
On Fri, Nov 18, 2016 at 09:26:36AM -0500, John Ferlan wrote:
> Create a utility routine in order to read the scsi_host fabric_name files
> looking for a match to a passed fabric_name
>
> Signed-off-by: John Ferlan <jferlan(a)redhat.com>
> ---
> src/libvirt_private.syms | 1 +
> src/util/virutil.c | 86
> ++++++++++++++++++++++++++++++++++++++++--------
> src/util/virutil.h | 4 +++
> 3 files changed, 78 insertions(+), 13 deletions(-)
>
> diff --git a/src/util/virutil.c b/src/util/virutil.c
> index a135819..fb72f2d 100644
> --- a/src/util/virutil.c
> +++ b/src/util/virutil.c
> @@ -2166,6 +2166,18 @@ virManageVport(const int parent_host,
> return ret;
> }
>
> +# define READ_WWN(wwn_path, buf) \
This macro either jumps to a label or alters a third variable.
I don't think its scope should extend one function.
> + do { \
> + if (virFileReadAll(wwn_path, 1024, &buf) < 0) \
> + goto cleanup; \
These two lines can be split out and with the STR{,N}EQ included,
this macro can be COMPARE_WWN, removing the need for changing
p. Or turned into a more complex function like virUSBSysReadFile.
Not quite sure why it's felt 'p' wouldn't need changing. On my test
system the "port_name", "node_name", and "fabric_wwn" files
each have
"0x######\n", but the stored/XML format will be ######
Maybe it's just late and I'm overthinking it.
> + if ((p = strchr(buf, '\n'))) \
> + *p = '\0'; \
> + if (STRPREFIX(buf, "0x")) \
> + p = buf + strlen("0x"); \
> + else \
> + p = buf; \
> + } while (0)
> +
> /* virGetFCHostNameByWWN:
> *
> * Iterate over the sysfs tree to get FC host name (e.g. host5)
The rest looks good to me.
So I went with a function:
/* virReadCompareWWN
* @prefix: path to the wwn file
* @d_name: name of the current directory
* @f_name: file name to read
*
* Read/compare the on-disk file with the passed wwn value.
*
* Returns:
* -1 : Error
* 0 : No match
* 1 : Match
*/
static int
virReadCompareWWN(const char *prefix,
const char *d_name,
const char *f_name,
const char *wwn)
{
char *path;
char *buf = NULL;
char *p;
int ret = -1;
if (virAsprintf(&path, "%s/%s/%s", prefix, d_name, f_name) < 0)
return -1;
if (!virFileExists(path)) {
ret = 0;
goto cleanup;
}
if (virFileReadAll(path, 1024, &buf) < 0)
goto cleanup;
if ((p = strchr(buf, '\n')))
*p = '\0';
if (STRPREFIX(buf, "0x"))
p = buf + strlen("0x");
else
p = buf;
if (STRNEQ(wwn, p))
ret = 0;
else
ret = 1;
cleanup:
VIR_FREE(path);
VIR_FREE(buf);
return ret;
}
It should be obvious what the callers do, but again I can post an
updated series as long as you're generally fine with this.
Tks -
John