Re: [PATCH 1/3] infiniband-diags: saquery, exit with ENODEV when queries fail to find results

[Ira Weiny <weiny2-i2BcT+NCU+M@public.gmane.org>]

On Sat, 9 Apr 2011 05:04:22 -0700
Hal Rosenstock <hal-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org> wrote:

> On 4/8/2011 4:45 PM, Ira Weiny wrote:
> > 
> > Subject: [PATCH 1/3] infiniband-diags: saquery, exit with ENODEV when queries fail to find results
> 
> 0 records is a perfectly valid response to a GetTable and that's
> different from a real error. Why not just indicate the number of records
> returned in dump_results ?

Traditionally a non-zero return means there was an error.  I was looking for a good example of an error being returned when there was nothing found.  Grep is the only example I could find which returns "1" when it does not find a match.

I think you are correct though that not finding any results is not an error.

I will reject the patch and clean up the next one (2/3).  I think 3/3 should have been separate anyway.

Ira

> 
> -- Hal
> 
> > 
> > Signed-off-by: Ira Weiny <weiny2-i2BcT+NCU+M@public.gmane.org>
> > ---
> >  src/saquery.c |   29 +++++++++++++++++++++++------
> >  1 files changed, 23 insertions(+), 6 deletions(-)
> > 
> > diff --git a/src/saquery.c b/src/saquery.c
> > index 03869e3..d7c8e6f 100644
> > --- a/src/saquery.c
> > +++ b/src/saquery.c
> > @@ -876,6 +876,9 @@ static int get_and_dump_any_records(bind_handle_t h, uint16_t attr_id,
> >  	if (ret)
> >  		return ret;
> >  
> > +	if (result.result_cnt == 0)
> > +		return ENODEV;
> > +
> >  	dump_results(&result, dump_func);
> >  
> >  	return 0;
> > @@ -896,7 +899,14 @@ static int get_and_dump_all_records(bind_handle_t h, uint16_t attr_id,
> >  	if (ret)
> >  		return ret;
> >  
> > +	if (result.result_cnt == 0) {
> > +		ret = ENODEV;
> > +		goto Exit;
> > +	}
> > +
> >  	dump_results(&result, dump_func);
> > +
> > +Exit:
> >  	return_mad();
> >  	return ret;
> >  }
> > @@ -915,7 +925,7 @@ static int get_lid_from_name(bind_handle_t h, const char *name, uint16_t * lid)
> >  	if (ret)
> >  		return ret;
> >  
> > -	ret = IB_NOT_FOUND;
> > +	ret = ENODEV;
> >  	for (i = 0; i < result.result_cnt; i++) {
> >  		node_record = get_query_rec(result.p_result_madw, i);
> >  		p_ni = &(node_record->node_info);
> > @@ -924,7 +934,7 @@ static int get_lid_from_name(bind_handle_t h, const char *name, uint16_t * lid)
> >  			       sizeof(node_record->node_desc.description)) ==
> >  		    0) {
> >  			*lid = cl_ntoh16(node_record->lid);
> > -			ret = IB_SUCCESS;
> > +			ret = 0;
> >  			break;
> >  		}
> >  	}
> > @@ -939,7 +949,7 @@ static uint16_t get_lid(bind_handle_t h, const char *name)
> >  	if (!name)
> >  		return 0;
> >  	if (isalpha(name[0])) {
> > -		if (get_lid_from_name(h, name, &rc_lid) != IB_SUCCESS) {
> > +		if (get_lid_from_name(h, name, &rc_lid) != 0) {
> >  			fprintf(stderr, "Failed to find lid for \"%s\"\n", name);
> >  			exit(EINVAL);
> >  		}
> > @@ -1040,6 +1050,8 @@ static int print_node_records(bind_handle_t h)
> >  	if (ret)
> >  		return ret;
> >  
> > +	ret = ENODEV;
> > +
> >  	if (node_print_desc == ALL_DESC) {
> >  		printf("   LID \"name\"\n");
> >  		printf("================\n");
> > @@ -1049,14 +1061,18 @@ static int print_node_records(bind_handle_t h)
> >  		node_record = get_query_rec(result.p_result_madw, i);
> >  		if (node_print_desc == ALL_DESC) {
> >  			print_node_desc(node_record);
> > +			ret = 0;
> >  		} else if (node_print_desc == NAME_OF_LID) {
> > -			if (requested_lid == cl_ntoh16(node_record->lid))
> > +			if (requested_lid == cl_ntoh16(node_record->lid)) {
> >  				print_node_record(node_record);
> > +				ret = 0;
> > +			}
> >  		} else if (node_print_desc == NAME_OF_GUID) {
> >  			ib_node_info_t *p_ni = &(node_record->node_info);
> > -
> > -			if (requested_guid == cl_ntoh64(p_ni->port_guid))
> > +			if (requested_guid == cl_ntoh64(p_ni->port_guid)) {
> >  				print_node_record(node_record);
> > +				ret = 0;
> > +			}
> >  		} else {
> >  			if (!requested_name ||
> >  			    (strncmp(requested_name,
> > @@ -1068,6 +1084,7 @@ static int print_node_records(bind_handle_t h)
> >  					return_mad();
> >  					exit(0);
> >  				}
> > +				ret = 0;
> >  			}
> >  		}
> >  	}
> 


-- 
Ira Weiny
Math Programmer/Computer Scientist
Lawrence Livermore National Lab
925-423-8008
weiny2-i2BcT+NCU+M@public.gmane.org
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