[dm-devel] [PATCH 6/9] libmultipath: print.c: fail hard if keywords are not found

[Benjamin Marzinski]

On Thu, Jul 15, 2021 at 12:52:20PM +0200, mwilck at suse.com wrote:
> From: Martin Wilck <mwilck at suse.com>
> 
> A failure in find_keyword() means an internal error. Fail hard rather
> than returning an empty string.
>
Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com> 
> Signed-off-by: Martin Wilck <mwilck at suse.com>
> ---
>  libmultipath/print.c | 101 +++++++++++++++----------------------------
>  1 file changed, 35 insertions(+), 66 deletions(-)
> 
> diff --git a/libmultipath/print.c b/libmultipath/print.c
> index 4bf2f7c..5b86483 100644
> --- a/libmultipath/print.c
> +++ b/libmultipath/print.c
> @@ -10,6 +10,7 @@
>  #include <unistd.h>
>  #include <string.h>
>  #include <errno.h>
> +#include <assert.h>
>  #include <libudev.h>
>  
>  #include "checkers.h"
> @@ -1294,14 +1295,9 @@ snprint_hwentry (const struct config *conf,
>  	size_t initial_len = get_strbuf_len(buff);
>  
>  	rootkw = find_keyword(conf->keywords, NULL, "devices");
> -
> -	if (!rootkw || !rootkw->sub)
> -		return 0;
> -
> +	assert(rootkw && rootkw->sub);
>  	rootkw = find_keyword(conf->keywords, rootkw->sub, "device");
> -
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
>  
>  	if ((rc = append_strbuf_str(buff, "\tdevice {\n")) < 0)
>  		return rc;
> @@ -1324,8 +1320,7 @@ static int snprint_hwtable(const struct config *conf, struct strbuf *buff,
>  	size_t initial_len = get_strbuf_len(buff);
>  
>  	rootkw = find_keyword(conf->keywords, NULL, "devices");
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
>  
>  	if ((rc = append_strbuf_str(buff, "devices {\n")) < 0)
>  		return rc;
> @@ -1355,8 +1350,7 @@ snprint_mpentry (const struct config *conf, struct strbuf *buff,
>  		return 0;
>  
>  	rootkw = find_keyword(conf->keywords, NULL, "multipath");
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
>  
>  	if ((rc = append_strbuf_str(buff, "\tmultipath {\n")) < 0)
>  		return rc;
> @@ -1387,8 +1381,7 @@ static int snprint_mptable(const struct config *conf, struct strbuf *buff,
>  	size_t initial_len = get_strbuf_len(buff);
>  
>  	rootkw = find_keyword(conf->keywords, NULL, "multipaths");
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
>  
>  	if ((rc = append_strbuf_str(buff, "multipaths {\n")) < 0)
>  		return rc;
> @@ -1435,8 +1428,7 @@ static int snprint_overrides(const struct config *conf, struct strbuf *buff,
>  	size_t initial_len = get_strbuf_len(buff);
>  
>  	rootkw = find_keyword(conf->keywords, NULL, "overrides");
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
>  
>  	if ((rc = append_strbuf_str(buff, "overrides {\n")) < 0)
>  		return rc;
> @@ -1461,8 +1453,7 @@ static int snprint_defaults(const struct config *conf, struct strbuf *buff)
>  	size_t initial_len = get_strbuf_len(buff);
>  
>  	rootkw = find_keyword(conf->keywords, NULL, "defaults");
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
>  
>  	if ((rc = append_strbuf_str(buff, "defaults {\n")) < 0)
>  		return rc;
> @@ -1584,63 +1575,52 @@ static int snprint_blacklist(const struct config *conf, struct strbuf *buff)
>  	struct blentry * ble;
>  	struct blentry_device * bled;
>  	struct keyword *rootkw;
> -	struct keyword *kw;
> +	struct keyword *kw, *pkw;
>  	size_t initial_len = get_strbuf_len(buff);
>  
>  	rootkw = find_keyword(conf->keywords, NULL, "blacklist");
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
>  
>  	if ((rc = append_strbuf_str(buff, "blacklist {\n")) < 0)
>  		return rc;
>  
>  	vector_foreach_slot (conf->blist_devnode, ble, i) {
>  		kw = find_keyword(conf->keywords, rootkw->sub, "devnode");
> -		if (!kw)
> -			return 0;
> +		assert(kw);
>  		if ((rc = snprint_keyword(buff, "\t%k %v\n", kw, ble)) < 0)
>  			return rc;
>  	}
>  	vector_foreach_slot (conf->blist_wwid, ble, i) {
>  		kw = find_keyword(conf->keywords, rootkw->sub, "wwid");
> -		if (!kw)
> -			return 0;
> +		assert(kw);
>  		if ((rc = snprint_keyword(buff, "\t%k %v\n", kw, ble)) < 0)
>  			return rc;
>  	}
>  	vector_foreach_slot (conf->blist_property, ble, i) {
>  		kw = find_keyword(conf->keywords, rootkw->sub, "property");
> -		if (!kw)
> -			return 0;
> +		assert(kw);
>  		if ((rc = snprint_keyword(buff, "\t%k %v\n", kw, ble)) < 0)
>  			return rc;
>  	}
>  	vector_foreach_slot (conf->blist_protocol, ble, i) {
>  		kw = find_keyword(conf->keywords, rootkw->sub, "protocol");
> -		if (!kw)
> -			return 0;
> +		assert(kw);
>  		if ((rc = snprint_keyword(buff, "\t%k %v\n", kw, ble)) < 0)
>  			return rc;
>  	}
>  
>  	rootkw = find_keyword(conf->keywords, rootkw->sub, "device");
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
> +	kw = find_keyword(conf->keywords, rootkw->sub, "vendor");
> +	pkw = find_keyword(conf->keywords, rootkw->sub, "product");
> +	assert(kw && pkw);
>  
>  	vector_foreach_slot (conf->blist_device, bled, i) {
> -		if ((rc = append_strbuf_str(buff, "\tdevice {\n")) < 0)
> -			return rc;
> -
> -		kw = find_keyword(conf->keywords, rootkw->sub, "vendor");
> -		if (!kw)
> -			return 0;
> -		if ((rc = snprint_keyword(buff, "\t\t%k %v\n", kw, bled)) < 0)
> +		if ((rc = snprint_keyword(buff, "\tdevice {\n\t\t%k %v\n",
> +					  kw, bled)) < 0)
>  			return rc;
> -		kw = find_keyword(conf->keywords, rootkw->sub, "product");
> -		if (!kw)
> -			return 0;
> -		if ((rc = snprint_keyword(buff,
> -					  "\t\t%k %v\n\t}\n", kw, bled)) < 0)
> +		if ((rc = snprint_keyword(buff, "\t\t%k %v\n\t}\n",
> +					  pkw, bled)) < 0)
>  			return rc;
>  	}
>  
> @@ -1656,63 +1636,52 @@ static int snprint_blacklist_except(const struct config *conf,
>  	struct blentry * ele;
>  	struct blentry_device * eled;
>  	struct keyword *rootkw;
> -	struct keyword *kw;
> +	struct keyword *kw, *pkw;
>  	size_t initial_len = get_strbuf_len(buff);
>  
>  	rootkw = find_keyword(conf->keywords, NULL, "blacklist_exceptions");
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
>  
>  	if ((rc = append_strbuf_str(buff, "blacklist_exceptions {\n")) < 0)
>  		return rc;
>  
>  	vector_foreach_slot (conf->elist_devnode, ele, i) {
>  		kw = find_keyword(conf->keywords, rootkw->sub, "devnode");
> -		if (!kw)
> -			return 0;
> +		assert(kw);
>  		if ((rc = snprint_keyword(buff, "\t%k %v\n", kw, ele)) < 0)
>  			return rc;
>  	}
>  	vector_foreach_slot (conf->elist_wwid, ele, i) {
>  		kw = find_keyword(conf->keywords, rootkw->sub, "wwid");
> -		if (!kw)
> -			return 0;
> +		assert(kw);
>  		if ((rc = snprint_keyword(buff, "\t%k %v\n", kw, ele)) < 0)
>  			return rc;
>  	}
>  	vector_foreach_slot (conf->elist_property, ele, i) {
>  		kw = find_keyword(conf->keywords, rootkw->sub, "property");
> -		if (!kw)
> -			return 0;
> +		assert(kw);
>  		if ((rc = snprint_keyword(buff, "\t%k %v\n", kw, ele)) < 0)
>  			return rc;
>  	}
>  	vector_foreach_slot (conf->elist_protocol, ele, i) {
>  		kw = find_keyword(conf->keywords, rootkw->sub, "protocol");
> -		if (!kw)
> -			return 0;
> +		assert(kw);
>  		if ((rc = snprint_keyword(buff, "\t%k %v\n", kw, ele)) < 0)
>  			return rc;
>  	}
>  
>  	rootkw = find_keyword(conf->keywords, rootkw->sub, "device");
> -	if (!rootkw)
> -		return 0;
> +	assert(rootkw);
> +	kw = find_keyword(conf->keywords, rootkw->sub, "vendor");
> +	pkw = find_keyword(conf->keywords, rootkw->sub, "product");
> +	assert(kw && pkw);
>  
>  	vector_foreach_slot (conf->elist_device, eled, i) {
> -		if ((rc = append_strbuf_str(buff, "\tdevice {\n")) < 0)
> -			return rc;
> -
> -		kw = find_keyword(conf->keywords, rootkw->sub, "vendor");
> -		if (!kw)
> -			return 0;
> -		if ((rc = snprint_keyword(buff, "\t\t%k %v\n", kw, eled)) < 0)
> +		if ((rc = snprint_keyword(buff, "\tdevice {\n\t\t%k %v\n",
> +					  kw, eled)) < 0)
>  			return rc;
> -		kw = find_keyword(conf->keywords, rootkw->sub, "product");
> -		if (!kw)
> -			return 0;
>  		if ((rc = snprint_keyword(buff, "\t\t%k %v\n\t}\n",
> -					  kw, eled)) < 0)
> +					  pkw, eled)) < 0)
>  			return rc;
>  	}
>  
> -- 
> 2.32.0